当前期刊: "林业工程"类期刊
显示样式:        排序: 导出
我的关注
我的收藏
您暂时未登录!
登录
  • Force-depth relationships with irradiation effect during spherical nano-indentation: A theoretical analysis
    J. Nucl. Mater. (IF 2.547) Pub Date : 2020-01-24
    Xiazi Xiao; Cewen Xiao; Xiaodong Xia

    A mechanistic model is developed for the force-depth relationship of ion-irradiated materials, which is conducted by spherical nano-indentation. With irradiation effect, the pop-in phenomenon almost disappears that is ascribed to the irradiation-induced defects serving as dislocation nucleation sites that facilitate the generation of new dislocations. After materials yielding, the evolution of statistically stored dislocations, geometrically necessary dislocations and irradiation-induced defects mutually contributes to the force-depth relationships with irradiation effect. Thereinto, the increase of loading force originates from the impediment of slipping dislocations by irradiation-induced defects. By comparing with the experimental data of Fe–12Cr alloy, a reasonable agreement is achieved.

    更新日期:2020-01-24
  • Significant growth of vacancy-type defects by post-irradiation annealing in neon ion-irradiated tungsten probed by a slow positron beam
    J. Nucl. Mater. (IF 2.547) Pub Date : 2020-01-23
    A. Yabuuchi; M. Tanaka; A. Kinomura

    Irradiation damage and its evolution in noble gas ion-irradiated tungsten have not been investigated in detail other than in the case of helium ion irradiation. In this study, irradiation-induced vacancy-type defects in helium ion- and neon ion-irradiated tungsten were investigated by using a slow positron beam, and their annealing behavior in the temperature range of 20∘C-900∘C was compared by characterizing the Doppler broadening of positron annihilation radiation spectra. In helium ion-irradiated tungsten, slight aggregation of irradiation-induced vacancy-type defects was observed upon annealing, but eventually, a large portion of the vacancy clusters was eliminated after annealing at 900∘C. In contrast, in neon ion-irradiated tungsten, irradiation-induced vacancy-type defects were observed to aggregate significantly at 300∘C and 600∘C. In addition, the large vacancy clusters formed by the aggregation survived even after annealing at 900∘C.

    更新日期:2020-01-24
  • Vacancy cluster growth and thermal recovery in hydrogen-irradiated tungsten
    J. Nucl. Mater. (IF 2.547) Pub Date : 2020-01-23
    M. Zibrov; W. Egger; J. Heikinheimo; M. Mayer; F. Tuomisto

    The thermal evolution of vacancies and vacancy clusters in tungsten (W) has been studied. W (100) single crystals were irradiated with 200 keV hydrogen (H) ions to a low damage level (5.8×10−3 dpa) at 290 K and then annealed at temperatures in the range of 500–1800 K. The resulting defects were characterized by positron annihilation lifetime spectroscopy (PALS) and positron annihilation Doppler broadening spectroscopy (DBS). Annealing at 700 K resulted in the formation of clusters containing 10–15 vacancies, while at 800 K and higher temperatures clusters containing about 20 vacancies or more were formed. Reduction of the defect concentration likely accompanied by further coarsening of the clusters started at 1300 K and ended at 1800 K with the complete defect recovery. The determined cluster sizes at 700 K and 800 K were larger than the estimated minimum cluster sizes that are thermally stable at these temperatures, indicating that the migration and ensuing coalescence of small clusters plays an important role in cluster growth.

    更新日期:2020-01-24
  • Annealing effects of TiO2 coating on cycling performance of Ni-rich cathode material LiNi0.8Co0.1Mn0.1O2 for lithium-ion battery
    Mater. Lett. (IF 3.019) Pub Date : 2020-01-24
    Shunyu Zhao; Yutao Zhu; Yucheng Qian; Nengneng Wangm; Meng Zhao; Jinlei Yao; Yanhui Xu

    Ni-rich LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode particles were coated with anatase TiO2 layer to improve its cycle stability. The TiO2 coating was synthesized by the hydrolyzation method and subsequent annealing treatment ranging from 500 ℃ to 600 ℃. The well-ordered layered α-NaFeO2-type structure survives in the TiO2 coating process. The nanothick anatase TiO2 layer coveres on the surface of NCM811. The annealing temperature of coating was controlled to improve the electrochemical performances. The TiO2-coated NCM811 cathode annealed at 600 ℃ demonstrates the optimal capacity retention of 104.9% after 100 cycles at the current rate of 0.1 C, in contrast to 64.1% of pristine NCM811 and 96.7% of the coated sample annealed at 500 ℃.

    更新日期:2020-01-24
  • 更新日期:2020-01-24
  • Porous graphene films with worm-like graphene surface as ultrafast adsorbents for oils and organic solvents
    Mater. Lett. (IF 3.019) Pub Date : 2020-01-24
    Yang Li; Jingjing Liu; Lihua Zhang; Qian Ren; Bin Shen
    更新日期:2020-01-24
  • Cationic surfactant at high pH in microwave HAp synthesis
    Mater. Lett. (IF 3.019) Pub Date : 2020-01-24
    D. Sánchez-Campos; D. Mendoza-Anaya; M.I. Reyes-Valderrama; S. Esteban-Gómez; V. Rodríguez-Lugo

    This work studies the cationic surfactant effects (CTAB) on the morphology and particle size of the hydroxyapatite (HAp), using the microwave method keeping the pH, time and temperature constant. The obtained products were characterized using transmission electron microscopy, X-ray diffraction, FT-IR and EDS spectroscopy. TEM results showed that surfactant had great impact on size of hydroxyapatite. The smallest nanorods structures with mean size of 43.17 nm in diameter and 136.52 nm in length were obtained by using 0.45w% [in proportion of Ca and P precursors] of surfactant. XRD analysis confirmed the presence of hexagonal hydroxyapatite and showed the crystallite size dimensions by Rietveld analysis. FT-IR technique corroborated the HAp presence by characteristic vibrational modes and EDS spectroscopy displayed the Ca/P ratio in all the samples. This work could be taken into account as a base for composite biomaterials development for gas sensing and biomaterial applications.

    更新日期:2020-01-24
  • Constructing novel hierarchical porous hydrangea-like ZnWO4 microspheres with enhanced photocatalytic performance
    Mater. Lett. (IF 3.019) Pub Date : 2020-01-24
    Miao Wang; Xin Yang; Shaoqin Tian; Yingying Guo; Tongming Sun; Minmin Wang; Yanfeng Tang
    更新日期:2020-01-24
  • Alternative Lengthening of Telomeres: Building Bridges To Connect Chromosome Ends
    Trends Cancer (IF 8.884) Pub Date : 2020-01-23
    Song My Hoang; Roderick J. O’Sullivan

    Alternative lengthening of telomeres (ALT) is a mechanism of telomere maintenance that is observed in many of the most recalcitrant cancer subtypes. Telomeres in ALT cancer cells exhibit a distinctive nucleoprotein architecture shaped by the mismanagement of chromatin that fosters cycles of DNA damage and replicative stress that activate homology-directed repair (HDR). Mutations in specific chromatin-remodeling factors appear to be key determinants of the emergence and survival of ALT cancer cells. However, these may represent vulnerabilities for the targeted elimination of ALT cancer cells that infiltrate tissues and organs to become devastating tumors. In this review we examine recent findings that provide new insights into the factors and mechanisms that mediate telomere length maintenance and survival of ALT cancer cells.

    更新日期:2020-01-24
  • Factors Impacting Efficacy of AAV-mediated CRISPR-based Genome Editing for Treatment of Choroidal Neovascularization.
    Mol. Ther. Methods Clin. Dev. (IF 4.875) Pub Date : 2020-01-23
    Sook Hyun Chung; Iris Natalie Mollhoff; Uyen Nguyen; Amy Nguyen; Natalie Stucka; Eric Tieu; Suman Manna; Ratheesh Kumar Maleppat; Pengfei Zhang; Emerald Lovece Nguyen; Jared Fong; Robert Zawadzki; Glenn Yiu

    Frequent injections of anti-vascular endothelial growth factor (anti-VEGF) agents are a clinical burden for patients with neovascular age-related macular degeneration (AMD). Genomic disruption of VEGF-A using adeno-associated viral (AAV) delivery of clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 has the potential to permanently suppress aberrant angiogenesis, but the factors that determine the optimal efficacy are unknown. Here, we investigate two widely-used Cas9 endonucleases, SpCas9 and SaCas9, and evaluate the relative contribution of AAV-delivery efficiency and genome-editing rates in vivo to determine the mechanisms that drive successful CRISPR-based suppression of VEGF-A, using a mouse model of laser-induced choroidal neovascularization (CNV). We found that SpCas9 demonstrated higher genome editing rates, greater VEGF reduction, and more effective CNV suppression than SaCas9, despite similar AAV transduction efficiency between a dual-vector approach for SpCas9 and single-vector system for SaCas9 to deliver the Cas9 orthologs and single guide RNAs (gRNAs). Our results suggest that successful VEGF knock-down using AAV-mediated CRISPR systems may be determined more by the efficiency of genome editing rather than viral transduction, and that SpCas9 may be more effective than SaCas9 as a potential therapeutic strategy for CRISPR-based treatment of CNV in neovascular AMD.

    更新日期:2020-01-24
  • Sphere-induced reprogramming of RPE cells into dual-potential RPE stem-like cells
    EBioMedicine (IF 6.680) Pub Date : 2020-01-24
    Fenghua Chen; Xiao Liu; Yao Chen; John Y. Liu; Huayi Lu; Wei Wang; Xiaoqin Lu; Kevin C. Dean; Ling Gao; Henry J. Kaplan; Douglas C. Dean; Xiaoyan Peng; Yongqing Liu
    更新日期:2020-01-24
  • White Matter Microstructure and the General Psychopathology Factor in Children
    J. Am. Acad. Child Adolesc. Psychiatry (IF 6.391) Pub Date : 2020-01-23
    Alexander Neumann; Ryan L. Muetzel; Benjamin B. Lahey; Marian J. Bakermans-Kranenburg; Marinus H. van IJzendoorn; Vincent W. Jaddoe; Manon H.J. Hillegers; Tonya White; Henning Tiemeier

    Objective Co-occurrence of behavioral and emotional problems in childhood is widespread and previous studies have suggested that this reflects vulnerability to experience a range of psychiatric problems, often termed a general psychopathology factor. However, the neurobiological substrate of this general factor is not well understood. We tested the hypothesis that lower overall white matter microstructure is associated with higher levels of the general psychopathology factor in children and less with specific factors. Method Global white matter microstructure at age 10 years was related to general and specific psychopathology factors. These factors were estimated using a latent bifactor model with multiple informants and instruments between ages 6-10 years in 3030 children from the population-based birth cohort Generation R. The association of global white matter microstructure and the psychopathology factors was examined with a structural equation model adjusted for sex, age at scan, age at psychopathology assessment, parental education/income and genetic ancestry. Results A 1-standard deviation (SD) increase of the global white matter factor was associated with a β=-0.07SD (SE=0.02, p<0.01) decrease in general psychopathology. In contrast, a 1-SD increase of white matter microstructure predicted an increase of β=+0.07SD (SE=0.03, p<0.01) specific externalizing factor levels. No association was found with the specific internalizing and specific attention factor. Conclusions The results suggest that general psychopathology in childhood is related to white matter structure across the brain and not only to specific tracts. Taking into account general psychopathology may also help reveal neurobiological mechanisms behind specific symptoms which are otherwise obscured by comorbidity.

    更新日期:2020-01-24
  • Sleep, Growth, and Puberty After Two Years of Prolonged-Release Melatonin in Children With Autism Spectrum Disorder
    J. Am. Acad. Child Adolesc. Psychiatry (IF 6.391) Pub Date : 2020-01-23
    Beth A. Malow; Robert L. Findling; Carmen M. Schroder; Athanasios Maras; John Breddy; Tali Nir; Nava Zisapel; Paul Gringras

    Objective A recent 3-month double-blind placebo-controlled study demonstrated efficacy and safety of child-appropriate prolonged-release melatonin (PedPRM) for insomnia in children with autism spectrum disorder (ASD). Here, we report on the long-term effects of PedPRM treatment on sleep, growth, body mass index, and pubertal development. Method Eighty children and adolescents (96% ASD) ages 2-17.5 years who completed the double-blind placebo-controlled trial were given 2, 5 or 10 mg PedPRM nightly up to 104 weeks, followed by a 2 week placebo period to assess withdrawal effects. Results Improvements in child sleep disturbance, and caregivers’ satisfaction of their child’s sleep patterns, quality of sleep and quality of life were maintained throughout the 104- week treatment period (p < 0.001 vs. baseline for all). During the 2-week withdrawal placebo period, measures declined as compared to the treatment period but were still improved compared to baseline. PedPRM was generally safe; the most frequent treatment-related adverse events (AE) were fatigue (6.3%), somnolence (6.3%), and mood swings (4.2%). The changes in mean weight, height, body mass index (BMI) and pubertal status (Tanner staging done by a physician) were within normal ranges for age with no evidence of delay in BMI or pubertal development. Conclusion Nightly PedPRM at optimal dose (2, 5, or 10 mg nightly) is safe and effective for long-term treatment in children and adolescents with ASD and insomnia. There were no observed detrimental effects on children’s growth and pubertal development and no withdrawal or safety issues related to the use or discontinuation of the drug.

    更新日期:2020-01-24
  • RET Solvent Front Mutations Mediate Acquired Resistance to Selective RET Inhibition in RET-driven malignancies
    J. Thorac. Oncol. (IF 12.460) Pub Date : 2020-01-24
    Benjamin J. Solomon; Lavinia Tan; Jessica J. Lin; Stephen Q. Wong; Sebastian Hollizeck; Kevin Ebata; Brian B. Tuch; Satoshi Yoda; Justin F. Gainor; Lecia V. Sequist; Geoffrey R. Oxnard; Oliver Gautschi; Alexander Drilon; Vivek Subbiah; Christine Khoo; Edward Y. Zhu; Michele Nguyen; Dahlia Henry; S. Michael Rothenberg

    Introduction Novel RET-specific tyrosine kinase inhibitors (TKIs) such as selpercatinib (LOXO-292) have shown unprecedented efficacy in tumors positive for RET fusions or mutations, notably RET fusion-positive non-small lung cancer (NSCLC) and RET-mutated medullary thyroid cancer (MTC). However, the mechanisms of resistance to these agents have not yet been described. Methods Analysis was performed of circulating tumor DNA and tissue in patients with RET fusion-positive NSCLC and RET-mutation positive MTC who developed disease progression following an initial response to selpercatinib. Acquired resistance was modeled preclinically using a CCDC6-RET fusion positive NSCLC patient derived xenograft (PDX). The inhibitory activity of anti-RET multikinase inhibitors (MKIs) and selective RET TKIs was evaluated in enzyme and cell-based assays. Results Following a dramatic initial response to selpercatinib in a patient with KIF5B-RET NSCLC, analysis of circulating tumor DNA (CtDNA) demonstrated emergence of RET G810R, S and C mutations in the RET solvent front prior to the emergence of clinical resistance. Post-mortem biopsy studies demonstrated intratumor and intertumor heterogeneity with distinct disease subclones containing G810S, G810R and G810C mutations in multiple disease sites indicative of convergent evolution upon the G810 residue resulting in a common mechanism of resistance. Acquired mutations in RET G810 were identified in progressing tissue from a second patient with CCDC6-RET fusion-positive NSCLC and in plasma from additional RET fusion-positive NSCLC and RET-mutant MTC patients progressing on an ongoing phase 1/2 trial of selpercatinib. Preclinical studies demonstrated the presence of RET G810R mutations in a CCDC6-RET PDX model of acquired resistance to selpercatinib. Structural modeling predicted that these mutations sterically hinder binding of selpercatinib, and in vitro assays confirmed loss of activity for both anti-RET MKIs and selective RET TKIs. Conclusion RET G810 solvent front mutations represent the first described recurrent mechanism of resistance to selective RET inhibition with selpercatinib. Development of potent inhibitor of these mutations, while maintaining activity against RET gatekeeper mutations, could be an effective strategy to target resistance to selective RET inhibitors.

    更新日期:2020-01-24
  • Clinicopathologic Characteristics of BRG1-Deficient Non-Small Cell Lung Cancer
    J. Thorac. Oncol. (IF 12.460) Pub Date : 2020-01-24
    Ibiayi Dagogo-Jack; Alexa B. Schrock; Marina Kem; Nicholas Jessop; Jessica Lee; Siraj M. Ali; Jeffrey S. Ross; Jochen K. Lennerz; Alice T. Shaw; Mari Mino-Kenudson

    Background Ten percent of non-small cell lung cancers (NSCLCs) harbor mutations in SMARCA4, the gene encoding the SWI/SNF ATPase BRG1. In preclinical models, BRG1 inactivation increases tumor aggressiveness but enhances sensitivity to drugs that target oxidative phosphorylation and inhibit SMARCA2, EZH2, or CDK4/6. To facilitate translation of preclinical findings into clinical studies exploiting these therapeutic vulnerabilities, we assessed the clinical features of patients with tumors harboring BRG1-inactivating mutations. Methods Datasets from Massachusetts General Hospital and Foundation Medicine were reviewed to determine the prevalence of SMARCA4-mutant NSCLC and describe its clinicopathologic characteristics. BRG1 expression was evaluated by immunohistochemistry and correlated with SMARCA4 mutations. Treatment outcomes were retrospectively assessed. Results We detected SMARCA4 genomic alterations in 9% (n=117/1,422) and 11% (n=3,188/27,281) of NSCLCs in the institutional and Foundation Medicine datasets, respectively. In both cohorts, truncating mutations comprised over one-third of SMARCA4 alterations. Twenty-nine (45%) of 64 SMARCA4-mutant NSCLCs assessed for BRG1 expression demonstrated loss of expression, most (90%) of which had truncating SMARCA4 mutations. Overall, eighty-four percent (n=26/31) of evaluated NSCLCs with truncating SMARCA4 mutations lacked BRG1 expression. Deficient BRG1 expression was predominantly detected in adenocarcinomas with co-occurring mutations in KRAS, TP53, KEAP1, and STK11. Among patients with BRG1-deficient NSCLC who received first-line platinum doublet chemotherapy (n=11) or chemotherapy plus immunotherapy (n=5), median progression-free survival was 38 and 35 days, respectively. Conclusions BRG1 deficiency is enriched in NSCLCs with truncating SMARCA4 mutations. Clinical outcomes are poor in this molecular subgroup, highlighting the importance of developing novel strategies to target unique vulnerabilities associated with the BRG1-deficient state.

    更新日期:2020-01-24
  • Left Atrial Strain Correlates with Elevated Filling Pressures in Pediatric Heart Transplantation Recipients
    J. Am. Soc. Echocardiog. (IF 6.111) Pub Date : 2020-01-24
    Robert W. Loar; Ricardo H. Pignatelli; Shaine A. Morris; John L. Colquitt; Douglas K. Feagin; Susan W. Denfield; Hari P. Tunuguntla

    Background Noninvasive assessment of diastolic function in pediatric heart transplantation (PHTx) patients is important for monitoring of rejection, cardiac allograft vasculopathy, and nonspecific graft failure. We hypothesized that left atrial strain (LAS) would correlate with pulmonary capillary wedge pressure (PCWP) and that cutoff values to identify elevated left ventricular (LV) filling pressure could be derived for clinical practice and future testing. Methods This was a secondary analysis of a prospectively collected cohort of PHTx patients undergoing same-day cardiac catheterization with biopsy and transthoracic echo. There were 70 patients with 85 clinical encounters. Traditional mitral inflow Doppler, LAS, LV diastolic strain and strain rate, and ratios for mitral E to LV diastolic strain and strain rate were assessed. Correlation with PCWP was performed, and receiver operator characteristic curves were generated for an elevated mean PCWP, acute rejection, and cardiac allograft vasculopathy. Results Decreased LAS during the atrial reservoir phase (Ɛres) correlated with higher invasively measured PCWP (r = –0.40, P < .001). An Ɛres cutoff of 14.5% had good discriminatory ability for an elevated PCWP (sensitivity 75%, specificity 82%), and Ɛres > 22.0% had 100% negative predictive value; Ɛres was superior to other measures of diastolic function. Subanalyses for recent acute rejection (n = 9) showed good discriminatory ability for Ɛres of 14.5% (sensitivity 89%, specificity 74%). Conclusions LAS correlates with invasively measured PCWP and can identify elevated pressures better than traditional and other advanced diastolic function parameters. Use of LAS in PHTx patients may aid in noninvasive monitoring for rejection and nonspecific graft dysfunction.

    更新日期:2020-01-24
  • Blood Speckle-Tracking Based on High–Frame Rate Ultrasound Imaging in Pediatric Cardiology
    J. Am. Soc. Echocardiog. (IF 6.111) Pub Date : 2020-01-24
    Siri A. Nyrnes; Solveig Fadnes; Morten Smedsrud Wigen; Luc Mertens; Lasse Lovstakken
    更新日期:2020-01-24
  • Geological, geophysical and plate kinematic constraints for models of the India-Asia collision and the post-Triassic central Tethys oceans
    Earth Sci. Rev. (IF 9.530) Pub Date : 2020-01-24
    Andrew J. Parsons; Kasra Hosseini; Richard Palin; Karin Sigloch

    In this study, we integrate bedrock datasets, observations of subducted slabs in the mantle, and plate kinematic constraints, to constrain models for the India-Asia collision and the central Tethys oceans. To accomplish this, we review: (1) the post-Triassic bedrock record of subduction in Tibet; (2) seismic tomographic imaging of subducted slabs in the mantle; (3) timing of the India-Asia collision; and (4) the pre-collisional size of Greater India. Following the assumption that slabs sink vertically through the mantle, their positions and geometries determined from seismic tomography constrain the locations and kinematics of paleo-subduction zones. Integrating this with bedrock constraints allows us to constrain post-Triassic subduction zone configurations for the central Tethys oceans. Neotethys was consumed by at least two subduction zones since the Jurassic. At the onset of the India-Asia collision at 59 ± 1 Ma, one subduction zone was active along the southern Asian continental margin at ~20°N. At that time, a second may have been active at subequatorial latitudes, but support for this from a bedrock perspective is lacking. This subduction zone configuration allows for three reconstructions for Greater India: The (1) minimum-area; (2) enlarged-area; and (3) Greater India Basin reconstructions. We integrate these reconstructions and subduction zone configurations in a plate kinematic framework to test their validity for the India-Asia collision. No single model is entirely satisfactory and each invokes assumptions that challenge accepted concepts. These include our understanding of suture zones, and the limits of continental subduction. We explore these challenges and their implications for our understanding of the India-Asia collision and continental collisions in general.

    更新日期:2020-01-24
  • Impact of Race on Survival in Pulmonary Arterial Hypertension: Results from the REVEAL Registry
    J. Heart Lung Transplant. (IF 8.578) Pub Date : 2020-01-24
    Sarah Medrek; Sandeep Sahay; Carol Zhao; Mona Selej; Adaani Frost

    Background Prior research has suggested that the prevalence and outcomes of pulmonary arterial hypertension (PAH) may vary by race or ethnicity. However, these studies have been limited by small sample size or methodological techniques relying on epidemiologic data. The purpose of this study is to evaluate the relationship between race/ethnicity and survival in a large U.S.-based prospective multicenter registry. Methods Patients in the Registry to Evaluate Early and Long-term PAH Disease Management (REVEAL), a five-year observational study of Group 1 PAH, were categorized by race/ethnicity. Baseline hemodynamic characteristics, clinical characteristics and medication use was described. The relationship between race/ethnicity and outcome was evaluated by Kaplan-Meier and Cox proportional hazards modeling techniques. Left-truncation analysis, which adjust for time from diagnosis to study enrollment, was used to minimize the effect of survivor bias. Results This analysis included 3,046 patients: 2,202 identified as white, 393 as black, 263 as Hispanic, 100 as Asian or Pacific Islander, and 88 as other. Unadjusted Kaplan-Meier survival analysis indicated that white patients had the lowest survival rates. After adjusting for variables of prognostic impact, race/ethnicity was no longer significantly associated with survival. Other results showed that black patients were more likely to have connective tissue disease associated PAH, Hispanic patients were more likely to have portopulmonary hypertension, and Asian patients were more likely to have congenital heart disease-associated PAH. Conclusions Analysis of the REVEAL registry did not find race/ethnicity to be a significant predictor of mortality. This is the largest analysis to date evaluating the role of race/ethnicity on outcomes in PAH.

    更新日期:2020-01-24
  • Long-term efficacy and safety of ruxolitinib versus best available therapy in polycythaemia vera (RESPONSE): 5-year follow up of a phase 3 study
    Lancet Haematol. (IF 11.990) Pub Date : 2020-01-23
    Jean-Jacques Kiladjian; Pierre Zachee; Masayuki Hino; Fabrizio Pane; Tamas Masszi; Claire N Harrison; Ruben Mesa; Carole B Miller; Francesco Passamonti; Simon Durrant; Martin Griesshammer; Keita Kirito; Carlos Besses; Beatriz Moiraghi; Elisa Rumi; Vittorio Rosti; Igor Wolfgang Blau; Nathalie Francillard; Srdan Verstovsek

    Background Polycythaemia vera is a myeloproliferative neoplasm characterised by excessive proliferation of erythroid, myeloid, and megakaryocytic components in the bone marrow due to mutations in the Janus kinase 2 (JAK2) gene. Ruxolitinib, a JAK 1 and JAK 2 inhibitor, showed superiority over best available therapy in a phase 2 study in patients with polycythaemia vera who were resistant to or intolerant of hydroxyurea. We aimed to compare the long-term safety and efficacy of ruxolitinib with best available therapy in patients with polycythaemia vera who were resistant to or intolerant of hydroxyurea. Methods We report the 5-year results for a randomised, open-label, phase 3 study (RESPONSE) that enrolled patients at 109 sites across North America, South America, Europe, and the Asia-Pacific region. Patients (18 years or older) with polycythaemia vera who were resistant to or intolerant of hydroxyurea were randomly assigned 1:1 to receive either ruxolitinib or best available therapy. Patients randomly assigned to the ruxolitinib group received the drug orally at a starting dose of 10 mg twice a day. Single-agent best available therapy comprised hydroxyurea, interferon or pegylated interferon, pipobroman, anagrelide, approved immunomodulators, or observation without pharmacological treatment. The primary endpoint, composite response (patients who achieved both haematocrit control without phlebotomy and 35% or more reduction from baseline in spleen volume) at 32 weeeks was previously reported. Patients receiving best available therapy could cross over to ruxolitinib after week 32. We assessed the durability of primary composite response, complete haematological remission, overall clinicohaematological response, overall survival, patient-reported outcomes, and safety after 5-years of follow-up. This study is registered with ClinicalTrials.gov, NCT01243944. Findings We enrolled patients between Oct 27, 2010, and Feb 13, 2013, and the study concluded on Feb 9, 2018. Of 342 individuals screened for eligibility, 222 patients were randomly assigned to receive ruxolitinib (n=110, 50%) or best available therapy (n=112, 50%). The median time since polycythaemia vera diagnosis was 8·2 years (IQR 3·9–12·3) in the ruxolitinib group and 9·3 years (4·9–13·8) in the best available therapy group. 98 (88%) of 112 patients initially randomly assigned to best available therapy crossed over to receive ruxolitinib and no patient remained on best available therapy after 80 weeks of study. Among 25 primary responders in the ruxolitinib group, six had progressed at the time of final analysis. At 5 years, the probability of maintaining primary composite response was 74% (95% CI 51–88). The probability of maintaining complete haematological remission was 55% (95% CI 32–73) and the probability of maintaining overall clinicohaematological responses was 67% (54–77). In the intention-to-treat analysis not accounting for crossover, the probability of survival at 5 years was 91·9% (84·4–95·9) with ruxolitinib therapy and 91·0% (82·8–95·4) with best available therapy. Anaemia was the most common adverse event in patients receiving ruxolitinib (rates per 100 patient-years of exposure were 8·9 for ruxolitinib and 8·8 for the crossover population), though most anaemia events were mild to moderate in severity (grade 1 or 2 anaemia rates per 100 patient-years of exposure were 8·0 for ruxolitinib and 8·2 for the crossover population). Non-haematological adverse events were generally lower with long-term ruxolitinib treatment than with best available therapy. Thromboembolic events were lower in the ruxolitinib group than the best available therapy group. There were two on-treatment deaths in the ruxolitinib group. One of these deaths was due to gastric adenocarcinoma, which was assessed by the investigator as related to ruxolitinib treatment. Interpretation We showed that ruxolitinib is a safe and effective long-term treatment option for patients with polycythaemia vera who are resistant to or intolerant of hydroxyurea. Taken together, ruxolitinib treatment offers the first widely approved therapeutic alternative for this post-hydroxyurea patient population. Funding Novartis Pharmaceuticals Corporation.

    更新日期:2020-01-24
  • Dallas Steatosis Index Identifies Patients With Nonalcoholic Fatty Liver Disease
    Clin. Gastroenterol. Hepatol. (IF 7.958) Pub Date : 2020-01-23
    Scott McHenry; Yikyung Park; Jeffrey D. Browning; Gregory Sayuk; Nicholas O. Davidson

    Background & Aims Tools have been developed to determine risk for nonalcoholic fatty liver disease (NAFLD) based on imaging, which does not always detect early-grade hepatic steatosis. We aimed to develop a tool to identify patients with NAFLD using 1H MR spectroscopy (MRS). Methods We collected data from the Dallas Heart Study—a multi-ethnic, population-based, probability study of adults (18–65 y) that comprised an in-home medical survey; collection of fasting blood samples; MRS images to measure cardiac mass/function, abdominal subcutaneous/visceral adiposity; and quantification of hepatic triglyceride concentration, from 2000 through 2009. NAFLD were defined as 5.5% or more liver fat and we excluded patients with more than moderate alcohol use; 737 patients were included in the final analysis. We performed binary multivariable logistic regression analysis to develop a tool to identify patients with NAFLD and evaluate interactions among variables. We performed an internal validation analysis using 10-fold cross validation. Results We developed the Dallas Steatosis Index (DSI) to identify patients with NAFLD based on level of alanine aminotransferase, body mass index, age, sex, levels of triglycerides and glucose, diabetes, hypertension, and ethnicity. The DSI discriminated between patients with vs without NAFLD with a C-statistic of 0.824. The DSI outperformed 4 risk analysis tools, based on net reclassification improvement and decision curve analysis. Conclusions We developed an index, called the DSI, which accurately identifies patients with NAFLD based on MRS data. The DSI requires external validation, but might be used in development NAFLD screening programs, in monitoring progression of hepatic steatosis, and in epidemiology studies.

    更新日期:2020-01-24
  • Plasma Soluble Urokinase Plasminogen Activator Receptor (suPAR) and CKD Progression in Children
    Am. J. Kidney Dis. (IF 6.653) Pub Date : 2020-01-24
    Darcy K. Weidemann; Alison G. Abraham; Jennifer L. Roem; Susan L. Furth; Bradley A. Warady

    Rationale & Objective Soluble urokinase plasminogen activator receptor (suPAR) is a novel biomarker associated with incident chronic kidney disease (CKD) and has been identified as an independent risk factor for CKD progression in children, although these findings remain preliminary, limited to a single point in time, and unreplicated in pediatric cohorts. Study Design Prospective longitudinal cohort study. Setting & Participants 565 participants aged 1 to 16 years enrolled in the Chronic Kidney Disease in Children (CKiD) Study. Exposure Plasma suPAR levels, categorized by quartiles, measured at study entry and a 6-month follow-up interval. Outcome CKD progression, defined as the initiation of kidney replacement therapy (dialysis or transplantation) or >50% decline in estimated glomerular filtrate rate (eGFR). Analytic Approach Associations between plasma suPAR quartiles and risk for CKD progression were estimated using lognormal survival models, adjusting for potential confounders. Results Participants in the highest suPAR quartile experienced 54% faster progression compared with the lowest quartile after adjustment for demographic and traditional CKD risk factors (P < 0.001). Addition of eGFR to the model attenuated the risk, although those in the highest quartile experienced 33% faster progression compared with the lowest quartile (P = 0.008). Plasma suPAR levels showed little change over 6 months. Limitations Potential for residual confounding, reliance on observational data, relatively fewer patients with higher eGFRs for subgroup analysis. Conclusions Higher suPAR levels are associated with shorter time to kidney replacement therapy or halving of eGFR in children with CKD. This association is attenuated slightly with inclusion of eGFR in regression modeling but remains a significant association for participants with the highest suPAR levels.

    更新日期:2020-01-24
  • Endocannabinoids mediate long-lasting behavioural and physiological changes in male rats induced by the repeated activation of the mesolimbic system by copulation to satiety
    Behav. Brain Res. (IF 2.770) Pub Date : 2020-01-24
    Estefanía González-Morales; Gabriela Rodríguez-Manzo

    Sexually satiated male rats exhibit long-lasting physiological changes, suggestive of brain plasticity, the most conspicuous of which are a sexual behaviour inhibition and a generalised drug hypersensitivity. Copulation activates the mesolimbic circuit increasing dopamine (DA) release in the nucleus accumbens (NAcc) and, enhanced midbrain DA neuron activity promotes endocannabinoid (eCB) release in the ventral tegmental area (VTA). The objective of this work was to explore the possible participation of DA and/or eCB transmission in the induction of these two long-lasting phenomena. To this aim we analysed the effect of blocking DA or CB1 receptors during the process of copulation to exhaustion, on the expression 24 h later, of the sexual inhibitory state and the hypersensitivity to two different drugs: 8-OH-DPAT, a 5-HT1A receptor agonist, and yohimbine, an α2-adrenoceptor antagonist. Blockade of DA receptors failed to prevent these phenomena, while blockade of CB1 receptors interfered with the appearance of the sexual inhibition and the hypersensitivity to both drugs in the sexually satiated animals. Specific blockade of CB1 receptors in the VTA during copulation to satiety mimicked these results, suggesting that both eCB-mediated effects were exerted in this brain region. It is concluded that eCBs play a role in the induction of behavioural and physiological changes, triggered by copulation to satiety, by acting at the VTA, while increased NAcc DA levels appear not to contribute to the changes induced by intense copulation. Results pose sexual satiety as a useful model for the study of brain plasticity phenomena induced by natural rewards.

    更新日期:2020-01-24
  • Effects of aging on the motor, cognitive and affective behaviors, neuroimmune responses and hippocampal gene expression
    Behav. Brain Res. (IF 2.770) Pub Date : 2020-01-24
    Gaurav Singhal; Julie Morgan; Magdalene C. Jawahar; Frances Corrigan; Emily J. Jaehne; Catherine Toben; James Breen; Stephen M. Pederson; Jim Manavis; Anthony J. Hannan; Bernhard T. Baune

    The known effects of aging on the brain and behavior include impaired cognition, increases in anxiety and depressive-like behaviors, and reduced locomotor activity. Environmental exposures and interventions also influence brain functions during aging. We investigated the effects of normal aging under controlled environmental conditions and in the absence of external interventions on locomotor activity, cognition, anxiety and depressive-like behaviors, immune function and hippocampal gene expression in C57BL/6 mice. Healthy mice at 4, 9, and 14 months of age underwent behavioral testing using an established behavioral battery, followed by cellular and molecular analysis using flow cytometry, immunohistochemistry, and quantitative PCR. We found that 14-month-old mice showed significantly reduced baseline locomotion, increased anxiety, and impaired spatial memory compared to younger counterparts. However, no significant differences were observed for depressive-like behavior in the forced-swim test. Microglia numbers in the dentate gyrus, as well as CD8+ memory T cells increased towards late middle age. Aging processes exerted a significant effect on the expression of 43 genes of interest in the hippocampus. We conclude that aging is associated with specific changes in locomotor activity, cognition, anxiety-like behaviors, neuroimmune responses and hippocampal gene expression.

    更新日期:2020-01-24
  • Overinhibition mediated by parvalbumin interneurons might contribute to depression-like behavior and working memory impairment induced by lipopolysaccharide challenge
    Behav. Brain Res. (IF 2.770) Pub Date : 2020-01-24
    Mu-huo Ji; Ling Zhang; Ming-jie Mao; Hui Zhang; Jiao-jiao Yang; Li-li Qiu

    Systemic inflammation induces cognitive impairments via unclear mechanisms. Accumulating evidence has demonstrated that a subset of neurons that express parvalbumin (PV) play a critical role in regulation of cognitive and emotional behavior. Thus, the aim of the present study was to test whether disruption of PV interneuron mediates systemic inflammation–induced depression-like behavior and working memory impairment by lipopolysaccharide (LPS) challenge. Here we showed that LPS induces depression-like behavior and working memory impairment, coinciding with increased PV expression, enhanced GABAergic transmission, and impaired long-term potentiation (LTP) in the hippocampus. Notably, systemic administration of NMDA (N–methyl–D–aspartate) receptor (NMDAR) antagonist ketamine was able to interfere with PV expression and reverse depression-like behavior and working memory impairment, which is probably mediated by reversing impaired LTP. In addition, flumazenil, a competitive antagonist acting at the benzodiazepine binding site of the GABAA receptor, also ameliorated these abnormal behaviors. Collectively, our study added growing evidence to the limited studies that overinhibition mediated by PV interneurons might play a critical role in LPS–induced depression-like behavior and working memory impairment.

    更新日期:2020-01-24
  • Blunted satiety in fatty Zucker rats
    Behav. Brain Res. (IF 2.770) Pub Date : 2020-01-24
    David P. Jarmolowicz; Tadd D. Schneider; Ale Carrillo; Jennifer L. Hudnall; Stefanie S. Stancato

    Levels of weight gain have hit an epidemic level with rates of overweight and obesity diagnoses topping all-time highs. Elevated body weight has been linked to increased rates of cardiac problems, blood pressure issues, and risk of developing type 2 diabetes. Leptin, a hormone produced by the body that is involved in energy balance by inhibiting hunger has been implicated as an underlying mechanism that differentially contributes to food-seeking motivation. Using a scientifically validated animal model of obesity, the fatty Zucker rat, which has mutated leptin receptor genes, leptin’s role in behavioral motivation can be assessed. Animals were on a 2 -h food access restriction with one-hour access to rewards in session and one hour of free-feeding access. Pre-session and post-session food access differences were evaluated in looking at motivation for food rewards during satiation while responding on differing levels of fixed-ratio schedules. The results showed robust differential behavior from satiation, demonstrating a basis for a biological mechanism involving leptin sensitivity that could underlie obesity. Although further experimentation is needed, understanding leptin could help bridge the gap in our understanding of satiation and non-satiation.

    更新日期:2020-01-24
  • Involvement of monoaminergic targets in the antidepressant- and anxiolytic-like effects of the synthetic alkamide Riparin IV: elucidation of further mechanisms through pharmacological, neurochemistry and computational approaches
    Behav. Brain Res. (IF 2.770) Pub Date : 2020-01-24
    Danusio Pinheiro Sartori; Natália Ferreira de Oliveira; José Tiago Valentim; Daniel Moreira Alves da Silva; Auriana Serra Vasconcelos; Iris Cristina Maia Oliveira; Raquell de Castro Chaves; Victor Celso Cavalcanti Capibaribe; Alyne Mara Rodrigues de Carvalho; Manoela de Oliveira Rebouças; Danielle Macêdo; Adriano José Maia Chaves Filho; Marta Maria de França Fonteles; Stanley Juan Chavez Gutierrez; José Maria Barbosa-Filho; Melina Mottin; Carolina Horta Andrade; Francisca Cléa Florenço de Sousa
    更新日期:2020-01-24
  • The Medial Agranular Cortex Mediates Attentional Enhancement of Prepulse Inhibition of the Startle Reflex
    Behav. Brain Res. (IF 2.770) Pub Date : 2020-01-24
    Qingxin Meng; Yu Ding; Liangjie Chen; Liang Li

    The startle reflex, which interferes with on-going cognitive/behavioral activities, is of important protective function for humans and animals. Prepulse inhibition (PPI), as an operational measure of sensorimotor gating, is the suppression of the startle reflex in response to an intense startling stimulus (pulse) when this startling stimulus is shortly preceded by a weaker non-startling stimulus (prepulse). In both humans and laboratory animals, PPI can be enhanced by facilitating selective attention to the prepulse, suggesting that higher-order cognitive/perceptual processes modulate PPI. It has been well known that both the cholinergic system located in the basal forebrain and the deep layers of the superior colliculus in the PPI-mediating circuit are top-down modulated by the medial agranular cortex (AGm), which is a subdivision of the medial prefrontal cortex (PFC) and has wide axonal connections with both cortical regions (including the posterior parietal cortex) and subcortical structures critical for attention/orientation processes. This study investigated whether the AGm is involved in attentional modulation of PPI. The results showed that PPI was enhanced by fear conditioning of the prepulse, and then further enhanced by perceived spatial separation between the conditioned prepulse and a back-ground masking noise based on the auditory precedence effect. Bilateral injection of 2-mM kynurenic acid, a broad spectrum antagonist of glutamate receptors, into the AGm, but not the primary somatosensory cortex, eliminated these two types of attentional enhancement of PPI. Thus, the AGm plays a role in facilitating attention to the prepulse and is involved in the top-down modulation of PPI.

    更新日期:2020-01-24
  • Differential Effects of Hunger on Cerebral Blood Flow in Healthy Adolescents
    Behav. Brain Res. (IF 2.770) Pub Date : 2020-01-23
    Céline Charroud; Nicolas Menjot de Champfleur; Emily Sanrey; Josef Pfeuffer; Jérémy Deverdun; Emmanuelle Le Bars; Philippe Coubes

    Adolescence represents a key developmental period in terms of both mood and overweight and is linked to disturbed eating behavior. Therefore, it is essential to investigate the basis of food intake in healthy adolescents by considering mood impacts which remain largely unexplored. Hence this study aims to investigate the impact of hunger and mood on cerebral blood flow (CBF) changes in healthy adolescents. Fifteen participants underwent two MRI sessions including a 3D pseudo-continuous arterial spin labeling sequence: pre-lunch (hunger) and post-lunch (satiety). Mood was assessed using the Multiscore Depression Inventory for Children. We found higher CBF values in the posterior insula in response to hunger compared to satiety, an area of the brain which contributes to the anticipation and motivation of feeding. In response to satiation, we observed higher CBF values in the precuneus, lingual gyrus and cuneus which are involved in the aspects of response inhibition related to food intake. Furthermore, we show that correlation between mood assessment and CBF is modulated by appetite in the precuneus, anterior cingulate gyrus, anterior orbitofrontal gyrus, occipital gyrus and cuneus, suggesting that participants affected by depressed mood could use ruminative processing in order to evaluate the reward of an upcoming meal.

    更新日期:2020-01-24
  • Iron-based mimetic enzyme sensor for NO photorelease from sodium nitroprusside
    J. Electroanal. Chem. (IF 3.218) Pub Date : 2020-01-24
    Pin Huang; Birong Zhang; Xueping Dang; Huaixia Chen; Dongyun Zheng
    更新日期:2020-01-24
  • Electrodeposition of superconducting rhenium-cobalt alloys from water-in-salt electrolytes
    J. Electroanal. Chem. (IF 3.218) Pub Date : 2020-01-24
    S. De; W.D. Sides; T. Brusuelas; Q. Huang

    Electrodeposition of rhenium-cobalt (Re-Co) alloys is investigated in water-in-salt electrolyte with a superhigh concentration of lithium chloride. Cyclic and linear sweep voltammetries, potentiostatic deposition, and X-ray fluorescence spectroscopy are used to characterize the electrochemical deposition behavior of electrolytes and determine the deposition rates of each elements. Re deposition rate is enhanced in the presence of Co and a constant alloy composition is observed within a wide range of potential, both of which are explained with a partial ionic stabilization effect of Co on Re. A completely miscible solid solution with hexagonal close pack structure is observed for ReCo alloys after annealing, where the lattice parameters linearly scale with the alloy compositions. The effect of Co alloying on the superconductivity of electrodeposited alloy films is also characterized down to 2 K.

    更新日期:2020-01-24
  • The fabrication of a new modified pencil graphite electrode for the electrocatalytic reduction of 2-nitrophenol in water samples
    J. Electroanal. Chem. (IF 3.218) Pub Date : 2020-01-24
    Gülşen Baysal; Demet Uzun; Erdoğan Hasdemir

    In this study, we report a sensitive modified pencil graphite electrode prepared by easily coating with 3-amino-1,2,4-triazole-5-thiol (3AT5T) for the selective determination of 2-nitrophenol (2-NP) by differential pulse voltammetry (DPV) method. The electrochemical methods, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), were applied to characterize this modified electrode in the mixture of K4[Fe(CN)6]/K3[Fe(CN)6] containing 0.1 M KCl as redox probe. Further, the electrode was characterized by Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). PGE demonstrated a remarkable increment in the redox probe's peak current, due to the effective electroactive surface area at the modified PGE (2.278 cm2) when it was compared with the bare PGE (0.128 cm2). This modified PGE was successfully used for the electrocatalytic reduction of 2-NP at pH 4.5 in 0.1 M phosphate (PBS) buffer. The reduction current response of 2-NP at the modified PGE was increased at about 8 times compared with the bare PGE. From the DPV analysis, under the optimized conditions, the reduction peak currents were increased linearly with two concentration intervals of 2-NP at pH 4.5 in PBS buffer. One of them is 45 nM–560 μM and the other is 560 μM–2 mM. The limit of detection (LOD) is found as 14.1 nM for 2-NP (S/N = 3). The fabricated PGE was tested in water samples for the practical utilization. From the results, it was pointed that the modified PGE can be used as an environmental sensor in analytical applications.

    更新日期:2020-01-24
  • 更新日期:2020-01-24
  • In silico study of the microalgae−bacteria symbiotic system in a stagnant pond
    Comput. Chem. Eng. (IF 3.334) Pub Date : 2020-01-24
    Maritza E. Cervantes-Gaxiola; Oscar M. Hernández-Calderón; Eusiel Rubio-Castro; Jesús R. Ortiz-del-Castillo; Marcos D. González-Llanes; Erika Y. Rios-Iribe

    A rigorous mathematical modeling of the symbiotic interaction between microalgae and bacteria in a stagnant pond is applied to analyze the effect of the operating conditions on the bioprocess kinetics. The microbial co-culture is described by a partial differential equations system, which is solved by a combined numerical method based on the Lagrangian Particle Tracking for microalgae transport equation and the Orthogonal Cubic Hermite Collocation for remaining transport equations. The effect of the temperature and light intensity, alkalinity, turbidity, initial ratio of biomasses, algal cell size, pond depth on the algal biomass productivity and the substrates removal is analyzed. It was found that all of them significantly affect the biomass production and the substrates removal, which is discussed in detail. Besides, a strong symbiotic interaction between cell growth of microalgae and bacteria is observed; specifically, bacterial growth was restricted by the microalgal growth, due to the limitation of dissolved oxygen.

    更新日期:2020-01-24
  • An accelerated dual method based on analytical extrapolation for distributed quadratic optimization of large-scale production complexes
    Comput. Chem. Eng. (IF 3.334) Pub Date : 2020-01-24
    Lukas Samuel Maxeiner; Sebastian Engell

    Chemical production sites usually consist of plants that are owned by different companies or business units but are tightly connected by streams of materials and carriers of energy. Distributed optimization, where each entity optimizes its objective and the transfer prices of energy and materials are adapted by a coordinator, is a promising approach to this kind of problems, as confidentiality of internal data can be preserved. In this contribution, we propose an extension of the widely used subgradient methods for inequality constrained distributed QPs, which we call analytical extrapolation (AE). Therein, the analytical structure of the dual function is exploited to speed up convergence. Two strategies for handling changing sets of active constraints are presented. We investigate the performance of our algorithm on test problems, where different problem parameters are varied, and show that the performance of our algorithm is in most cases significantly better than that of other methods.

    更新日期:2020-01-24
  • Adaptive predictive control of bioprocesses with constraint-based modeling and estimation
    Comput. Chem. Eng. (IF 3.334) Pub Date : 2020-01-24
    Banafsheh Jabarivelisdeh; Lisa Carius; Rolf Findeisen; Steffen Waldherr

    Control of biotechnological processes is currently recipe-based with insufficient ability to handle possible uncertainties, which results in suboptimal production processes. To address this problem, model-based optimization and control approaches can be implemented to derive optimal control strategies. However, for reliable performance of model-based control, it is crucial to use flexible and adaptive control strategies which address biological variability while compensating for uncertainties. In this work, we present an approach for adaptive control of a bioprocess based on dynamic flux balance models. A previously developed bilevel approach for bioprocess optimization is implemented inside a model predictive control (MPC) routine. To account for model uncertainties, a moving horizon estimation algorithm is combined with the MPC in order to estimate uncertain parameters of the underlying model online for different metabolic modes. We apply this method to maximize the productivity of a target metabolite under microaerobic conditions by adapting the degree of oxygen-limitation online.

    更新日期:2020-01-24
  • Nonlinear Model Predictive Control of an Industrial Process with Steady-state Gain Inversion
    Comput. Chem. Eng. (IF 3.334) Pub Date : 2020-01-24
    Rahul Bindlish

    Nonlinear model predictive controller (NMPC) is formulated for an industrial process with steady-state gain inversion so that the output variable can be maximized at the peak in presence of disturbances. Appropriate disturbance model formulation is used along with a novel output measurement to allow for robust control in presence of both measured and unmeasured disturbances at the peak where steady-state gain inversion occurs. The constrained nonlinear controller for a process with steady-state gain inversion has been applied successfully with results from plant data that show robustness in maximizing the selectivity of effluent ethylene oxide in the industrial ethylene epoxidation reactor.

    更新日期:2020-01-24
  • Biomass-Based Integrated Gasification Combined Cycle With Post-Combustion Co2 Recovery by Potassium Carbonate: Techno-Economic and Environmental Analysis
    Comput. Chem. Eng. (IF 3.334) Pub Date : 2020-01-24
    Ikhlas Ghiat; Ahmed AlNouss; Gordon McKay; Tareq Al-Ansari

    In this study, a thermodynamic model depicting integrated bioenergy with carbon capture and storage (BECCS) system is developed using Aspen Plus under thermodynamic equilibrium for the power generation segment, and a rate-based model for the carbon capture segment representing CO2 recovery from the exhaust flue of a biomass based integrated gasification combined cycle (BIGCC). A thorough techno-economic analysis is conducted for the integrated system to evaluate system-wide environmental impacts and economic costs. The carbon capture is modelled using post combustion technology with chemical absorption by means of Piperazine promoted potassium carbonate to absorb the CO2 from the exhaust stream of the gas turbine. The results demonstrate that the proposed system with 80% carbon capture has negative emissions of -0.31 kg/kWh of CO2-e, when assuming neutral emissions from the BIGCC. For a production of 419 kW of net electricity, the overall energy and exergy efficiencies are 43.8% and 57.2% respectively.

    更新日期:2020-01-24
  • An artificial neural network approach to recognise kinetic models from experimental data
    Comput. Chem. Eng. (IF 3.334) Pub Date : 2020-01-24
    Marco Quaglio; Louise Roberts; Mohd Safarizal Bin Jaapar; Eric S. Fraga; Vivek Dua; Federico Galvanin

    The quantitative description of the dynamic behaviour of reacting systems requires the identification of an appropriate set of kinetic model equations. The selection of the correct model may pose substantial challenges as there may be a large number of candidate kinetic model structures. In this work, a model selection approach is presented where an Artificial Neural Network classifier is trained for recognising appropriate kinetic model structures given the available experimental evidence. The method does not require the fitting of kinetic parameters and it is well suited when there is a high number of candidate kinetic mechanisms. The approach is demonstrated on a simulated case study on the selection of a kinetic model for describing the dynamics of a three-component reacting system in a batch reactor. The sensitivity of the approach to a change in the experimental design and to a change in the system noise is assessed.

    更新日期:2020-01-24
  • The Prefrontal Cortex and the Caudate Nucleus Respond Conjointly to Methylphenidate (Ritalin). Concomitant Behavioral and Neuronal Recording Study
    Brain Res. Bull. (IF 3.103) Pub Date : 2020-01-24
    Sidish S. Venkataraman; Catherine M. Claussen; Natasha Kharas; Nachum Dafny

    Methylphenidate (MPD) is commonly used to treat attention-deficit hyperactivity disorder (ADHD). Recently, it is being abused for cognitive enhancement and recreation leading to concerns regarding its addictive potential. The prefrontal cortex (PFC) and caudate nucleus (CN) are two of the brain structures involved in the motive/reward circuit most affected by MPD and are also thought to be responsible for ADHD phenomena. This study is unique in that it investigated acute and chronic, dose-response MPD exposure on animals’ behavior activity concomitantly with PFC and CN neuronal circuitry in freely behaving adult animals without the interference of anesthesia. Further, it compared acute and chronic MPD action on over 1,000 subcortical and cortical neurons simultaneously, allowing for a more accurate interpretation of drug action on corticostriatal neuronal circuitry. For this experiment, four groups of animals were used: saline (control), 0.6, 2.5, and 10.0 mg/kg MPD following acute and repetitive exposure. The data shows that the same MPD dose elicits behavioral sensitization in some animals and tolerance in others and that the PFC and CN neuronal activity correlates with the animals' behavioral responses to MPD. The expression of sensitization and tolerance are experimental biomarkers indicating that a drug has addictive potential. In general, a greater percentage of CN units responded to both acute and chronic MPD exposure as compared to PFC units. Dose response differences between the PFC and the CN units were observed. The dichotomy that some PFC and CN units responded to the same MPD dose by excitation and other units by attenuation in neuronal firing rate is discussed. In conclusion, to understand the mechanism of action of the drug, it is essential to study, simultaneously, on more than one brain site, the electrophysiological and behavioral effects of acute and chronic drug exposure, as sensitization and tolerance are experimental biomarkers indicating that a drug has addictive potential. The behavioral and neuronal data obtained from this study indicates that chronic MPD exposure results in behavioral and biochemical changes consistent with a substance abuse disorder.

    更新日期:2020-01-24
  • Xenon modulates the GABA and glutamate responses at genuine synaptic levels in rat spinal neurons
    Brain Res. Bull. (IF 3.103) Pub Date : 2020-01-24
    Hisahiko Kubota; Hironari Akaike; Nobuharu Okamitsu; Il-Sung Jang; Kiku Nonaka; Naoki Kotani; Norio Akaike

    Effects of xenon (Xe) on whole-cell currents induced by glutamate (Glu), its three ionotropic subtypes, and GABA, as well as on the fast synaptic glutamatergic and GABAergic transmissions, were studied in the mechanically dissociated “synapse bouton preparation” of rat spinal sacral dorsal commissural nucleus (SDCN) neurons. This technique evaluates pure single or multi-synapse responses from native functional nerve endings and enables us to quantify how Xe influences pre- and postsynaptic transmissions accurately. Effects of Xe on glutamate (Glu)-, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-, kainate (KA)- and N-methyl-d-aspartate (NMDA)- and GABAA receptor-mediated whole-cell currents were investigated by the conventional whole-cell patch configuration. Excitatory and inhibitory postsynaptic currents (EPSCs and IPSCs) were measured as spontaneous (s) and evoked (e) EPSCs and IPSCs. Evoked synaptic currents were elicited by paired-pulse focal electric stimulation. Xe decreased Glu, AMPA, KA, and NMDA receptor-mediated whole-cell currents but did not change GABAA receptor-mediated whole-cell currents. Xe decreased the frequency and amplitude but did not affect the 1/e decay time of the glutamatergic sEPSCs. Xe decreased the frequency without affecting the amplitude and 1/e decay time of GABAergic sIPSCs. Xe decreased the amplitude and increased the failure rate (Rf) and paired-pulse ratio (PPR) without altering the 1/e decay time of both eEPSC and eIPSC, suggesting that Xe acts on the presynaptic side of the synapse. The presynaptic inhibition was greater in eEPSCs than in eIPSCs. We conclude that Xe decreases glutamatergic and GABAergic spontaneous and evoked transmissions at the presynaptic level. The glutamatergic presynaptic responses are the main target of anesthesia-induced neuronal responses. In contrast, GABAergic responses minimally contribute to Xe anesthesia.

    更新日期:2020-01-24
  • Zinc ferrite as a magnetic sorbent for the dispersive micro solid-phase extraction of sulfonamides and their determination by HPLC
    Microchem. J. (IF 3.206) Pub Date : 2020-01-24
    Theodoros Chatzimitakos; Constantine Stalikas

    Although zinc is known to have a high affinity for sulfonamides, there are no sample preparation procedures based on this property. In this study, the use of zinc ferrites in a magnetic, ultrasound-assisted dispersive micro solid-phase procedure for the determination of sulfonamides is developed. Zinc ferrites can efficiently and selectively extract sulfonamides from environmental and food matrixes. The synthesis of zinc ferrites is straightforward, and the resulting materials exhibit favorable magnetic properties for their harvesting after extraction. As a proof of concept, an analytical method was developed for the determination of sulfonamides in lake water and egg using high-performance liquid chromatography. The new procedure exhibits low limits of quantification (0.06 up to 0.11 μg L−1), low matrix effect (from -8% to 8%), acceptable recoveries (88-101%) and satisfactory enrichment factors (111-141). Moreover, the method has a wide linear range (up to 250 μg L−1) making it possible the determination of sulfonamides at concentrations above or below the maximum residue limit. Due to the aforementioned merits as well as the simplicity, the few synthetic steps required and the efficiency of sample preparation, the developed method can be used for routine analysis of sulfonamides. Moreover, this study highlights the affinity of zinc for sulfonamides, a property that has never reaped before in analytical chemistry.

    更新日期:2020-01-24
  • Competition and water stress indices as predictors of Pinus halepensis Mill. radial growth under drought
    Forest Ecol. Manag. (IF 3.126) Pub Date : 2020-01-24
    Manon Helluy; Bernard Prévosto; Maxime Cailleret; Catherine Fernandez; Philippe Balandier

    The frequency, duration, and severity of drought events are expected to increase in the Mediterranean area as a result of climate change, with strong impacts on forest ecosystems and in particular individual tree growth. Tree growth response to drought is strongly influenced by local site and stand characteristics that can be quantified using competition indices (CIs) and water stress indices (WSIs). These indices have been widely used to predict tree growth; however, they are numerous, and few studies have investigated them jointly. In this context, we investigated the potential of using CIs and WSIs to investigate tree behaviour under drought. The main objective of this study was to quantify P. halepensis Mill. annual radial growth using tree size from the previous year, CIs and WSIs. We studied twelve 50-year-old Pinus halepensis plots located in the South-East of France distributed in different density treatments (light, medium and dense). At each plot, all trees were measured (height, circumference), spatialized and the ring-widths were measured for ~15 trees. We also developed a two-strata (over- and understorey) forest water balance model to simulate soil water content at a daily resolution based on stand characteristics (LAI values in particular) and soil properties. A mixed modelling approach was eventually used to investigate the drivers of P. halepensis annual radial growth and to test the performance of five CIs and four WSIs. The best growth model included tree size, the sum of Basal Area of Larger trees in a 5 m-radius (BAL; as CI), and the number of days that trees experienced water stress in a year (as WSI) as predictors. This model explained up to 56% of the variance in observed pine tree growth, which increased up to 77% when the individual tree was included as a random effect on the intercept. We found that distance-independent CIs can perform as well as distance-dependent CIs in our study site. The duration of drought alone appeared to better predict tree growth than drought intensity and duration, or drought timing. The selected model led us to reaffirm the positive effect of thinning on tree secondary growth when facing long and intense drought.

    更新日期:2020-01-24
  • Are photosynthetic leaf traits related to the first-year growth of tropical tree seedlings? A light-induced plasticity test in a secondary forest enrichment planting
    Forest Ecol. Manag. (IF 3.126) Pub Date : 2020-01-24
    Victor Alexandre Hardt Ferreira dos Santos; Marciel José Ferreira

    Understanding light-induced plasticity of growth and its relationship with photosynthetic trait plasticity is central to the identification of the mechanisms associated with tropical tree seedling establishment in enrichment plantings. In a secondary forest submitted to silvicultural treatments – that manipulate light environment – and enriched with six tropical tree species we tested three main hypothesis. First, the growth of the six species are related to photosynthetic leaf traits; second, there is a relationship between the light-induced plasticity of growth and photosynthetic leaf traits and, finally, that growth plasticity is a subjacent mechanism of the growth-survival trade-off. Growth was analyzed as a biomass index that combines collar and height growth. Photosynthetic leaf traits were selected considering their significance in the photosynthetic process: light interception (specific leaf area, SLA), light absorption (chlorophyll a and b ratio, Chla/b), light use (fluorescence parameters, Fv/Fm; PIabs, PItotal), biochemical limitations (light-saturated CO2 assimilation, Asat) and diffusive limitations (stomatal conductance, gs). The plasticity was represented by the slope of the relationship between the canopy light transmittance and growth and the photosynthetic leaf traits. At the end of the first year after planting, growth was related to almost all photosynthetic leaf traits, and the strongest relationships (high slope and R2) were observed with Asat, SLA and PItotal. Light-induced growth plasticity varied three times between species. The interspecific growth plasticity was related to SLA and Fv/Fm plasticity, which varied 4.9 and 2.4 times between species, respectively. Seedling mortality in the shaded understory and the growth in a high light environment were associated with growth plasticity. Photosynthetic leaf traits effectively represent the growth response mechanisms to silvicultural treatments that manipulate the light environment in enrichment plantings, and the subjacent mechanism of growth plasticity has an intrinsic effect on the growth-survival trade-off.

    更新日期:2020-01-24
  • The relationship between toxic phytoplankton species occurrence and environmental and meteorological factors along the Eastern Adriatic coast
    Harmful Algae (IF 5.012) Pub Date : 2020-01-24
    Živana Ninčević Gladan; Frano Matić; Jasna Arapov; Sanda Skejić; Mia Bužančić; Ana Bakrač; Maja Straka; Quentin Dekneudt; Branka Grbec; Roman Garber; Nikša Nazlić

    In this study, the time series of toxic phytoplankton species collected between 2004 and 2018 from the Northern Adriatic, Šibenik Bay, and Mali Ston Bay was analyzed in relation to environmental (temperature, salinity, water column stability, and river flow) and meteorological parameters (precipitation and wind). Because of the mostly non-linear relation between biotic and abiotic parameters, self-organizing maps (SOM) were used to identify these relationships. SOM analysis distinguished species of the genus Dinophysis from Gonyaulax spinifera and Lingulodinium polyedrum species, which better tolerate wind-induced disturbance. Among the Dinophysis species, Dinophysis fortii, Dinophysis tripos, and Dinophysis acuta preferred higher precipitation rate and river flow in addition to optimal temperatures. The abundances of Alexandrium species, which occurred more frequently in estuarine areas, were associated with river flow and maximum stable water column. Regardless of the ecological preferences of individual harmful algae, freshwater inflow-caused stratification is present in all clusters of environmental conditions associated with increased abundances of harmful algae in the SOM analysis. It is highly likely that stratification represents an important factor for the development and maintenance of HABs. The non-linear relationship between the NAO index and rainfall was noted, of which the most important for the development of harmful algae is the proportional correlation between the positive phase of the NAO index and higher rainfall, especially in winter and spring. Such conditions are conducive to the development of harmful algae because, with the increase in temperature accompanying the positive phase of the NAO index, increased rainfall further stimulates their growth. This can be achieved either through nutrient yields or through higher freshwater inflow that further stabilizes the water column.

    更新日期:2020-01-24
  • Effectiveness of a peracetic acid solution on Escherichia coli reduction during fresh-cut lettuce processing at the laboratory and industrial scales
    Int. J. Food Microbiol. (IF 4.006) Pub Date : 2020-01-24
    J.L. Banach; H. van Bokhorst-van de Veen; L.S. van Overbeek; P.S. van der Zouwen; M.H. Zwietering; H.J. van der Fels-Klerx

    Fresh leafy greens like lettuce can be consumed raw and are susceptible to food-borne pathogens if they become contaminated. Recently, the number of reported pathogenic foodborne outbreaks related to leafy greens has increased. Therefore, it is important to try to alleviate the human health burden associated with these outbreaks. Processing of fresh-cut lettuce, including washing, is a step in the supply chain that needs to be well controlled to avoid cross-contamination. Current measures to control the quality of lettuce during washing include the use of chemicals like chlorine; however, questions regarding the safety of chlorine have prompted research for alternative solutions with peracetic acid (PAA). This study evaluates the effectiveness of a PAA (c.a. 75 mg/L) solution on the reduction of a commensal E. coli strain during the washing of fresh-cut lettuce. Experiments were performed at the laboratory scale and validated at the industrial scale. We observed that the use of PAA was not adversely affected by the organic load in the water. The contact time and dose of the PAA showed to be relevant factors, as observed by the approximately 5-log reduction of E. coli in the water. Results showed that once introduced during washing, E. coli remained attached to the lettuce, thus supporting the need to control for pathogenic bacteria earlier in the supply chain (e.g., during primary production) as well as during washing. Moreover, our results showed that the use of PAA during washing did not have an apparent effect on the levels of fluorescent pseudomonads (FP) and total heterotrophic bacteria (THB) in lettuce. Overall, our results at the laboratory and industrial-scales confirmed that during the processing of fresh-cut produce, where the accumulation of soil, debris, and other plant exudates can negatively affect washing, the use of a PAA (c.a. 75 mg/L) solution was an effective and safe wash water disinfectant that can potentially be used at the industrial-scale.

    更新日期:2020-01-24
  • Microbial safety of cheese in Canada
    Int. J. Food Microbiol. (IF 4.006) Pub Date : 2020-01-24
    Kyle Ganz; Etsuko Yamamoto; Kate Hardie; Christine Hum; Hussein Hussein; Annie Locas; Marina Steele

    A profile of the microbial safety of cheese in Canada was established based on the analysis of 2955 pasteurized and raw-milk cheeses tested under Canada's National Microbiological Monitoring Program (NMMP) and 2009 raw-milk cheeses tested under the Targeted Survey Program. 97.8% of NMMP and 99.6% of Targeted Survey cheese samples were assessed as being of satisfactory microbiological safety. Under the NMMP, Salmonella spp. was detected in 2 samples, Listeria monocytogenes was detected in 15 samples and no Escherichia coli O157/H7:NM (non-motile) was detected. Cheese samples assessed as having unsatisfactory levels of S. aureus and generic E. coli were found in 18 and 41 samples, respectively. Under the Targeted Survey, L. monocytogenes was detected in 2 samples, while no Salmonella spp. or E. coli O157/H7:NM were detected. Cheese samples assessed as having investigative and unsatisfactory levels of S. aureus were found in 4 and 2 samples respectively. No samples were found to have investigative or unsatisfactory levels of generic E. coli. For cheese samples collected under the NMMP, logistic regression models indicated that contamination was more frequent in raw-milk cheeses compared to pasteurized-milk cheeses (OR = 5.0, 95% CI (3.0, 8.3)), and in imported cheeses compared to domestic cheeses (OR = 8.18, 95% CI (4.1, 16.1)). A statistically significant association was found between cheese samples assessed as having unsatisfactory levels of generic E. coli and detection of L. monocytogenes, Salmonella spp. or levels of S. aureus that were assessed as unsatisfactory (p < .001). These test results will help support risk analysis and inform food safety decisions.

    更新日期:2020-01-24
  • Endurance training but not high-intensity interval training reduces liver carcinogenesis in mice with hepatocellular carcinogen diethylnitrosamine
    Exp. Gerontol. (IF 3.080) Pub Date : 2020-01-24
    Xue Zhang; Lu Cao; Benlong Ji; Lingxia Li; Zhengtang Qi; Shuzhe Ding

    Physical activity may reduce cancer initiation. High-intensity interval training (HIT) has been reported to be superior to moderate continuous endurance training (ET) for maximizing health outcomes in cardiovascular disease, obesity and type 2 diabetes. However, the role of HIT vs. ET in the prevention of liver cancer is poorly understood. This study aimed to determine how HIT vs. ET affects cancer initiation in mice with the hepatocellular carcinogen diethylnitrosamine (DEN). C57BL/6 mice were treated with DEN at 3–12 weeks of age and, from 8 to 26 weeks of age, treated with either of exercise modes on treadmill: HIT (85–90% VO2max with intervals) and ET (65–75% VO2max without intervals). We found that mice treated with ET had lower cancer initiation but higher fat mass compared to control DEN-injected mice. In contrast, HIT could not significantly reduce cancer initiation and tumor volumes. Metabolomic analysis in the liver indicated marked differences in cholesterol, palmitic acid, stearic acid, uracil, hydroxypyridine and maltose between HIT- and ET-treated mice, and demonstrated good and obvious separation between ET and DEN control group. Furthermore, mice treated with ET had lower expression of pro-inflammatory cytokines and pro-proliferation genes in liver compared to DEN control group. ET protocol reduced the accumulation of toxic metabolite carbamate, increased the protein level of caspase-1, and reduced JNK phosphorylation in liver. These data indicates that moderate-intensity endurance training may be superior to high-intensity interval training for reducing liver cancer initiation in mice.

    更新日期:2020-01-24
  • FaMYB9 is involved in the regulation of C6 volatile biosynthesis in strawberry
    Plant Sci. (IF 3.785) Pub Date : 2020-01-24
    Hongyan Lu; Zisheng Luo; Lei Wang; Wusheng Liu; Dong Li; Tarun Belwal; Yanqun Xu; Li Li

    The large-scale untargeted proteomic and metabolomic studies were conducted in strawberry (Fragaria × ananassa) cv. Akihime fruit at five developmental stages. We found that some C6 volatiles highly contributed to the enrichment of volatiles at the red stage of strawberry fruit. We found that 12 genes involved in LOX pathway for volatile biosynthesis showed multiple patterns in protein abundance during fruit development and ripening, and 9 out of the 12 genes exhibited a significant increase in their relative expression levels at the red stage of fruit. We also found that the MYB9 gene (FaMYB9) expression level was positively correlated with the content of C6 volatiles (R = 0.989) and with the relative expression level and protein abundance of FaLOX5 at different strawberry fruit developmental stages (R = 0.954). The interaction between FaMYB9 and FaLOX5 was detected by yeast two-hybrid, co-immunoprecipitation (Co-IP), bimolecular fluorescence complementation (BiFC), and immunofluorescence (IF) analyses. Transient silencing of FaMYB9 delayed the fruit development and ripening, resulting in a significant decrease in the contents of C6 volatiles, while overexpression of FaMYB9 increased the fruit development and ripening and the contents of C6 volatiles in Akihime fruit. Therefore, FaMYB9 is positively involved in C6 volatile biosynthesis.

    更新日期:2020-01-24
  • GmGPA3 is involved in post-Golgi trafficking of storage proteins and cell growth in soybean cotyledons
    Plant Sci. (IF 3.785) Pub Date : 2020-01-24
    Zhongyan Wei; Yu Chen; Bo Zhang; Yulong Ren; Lijuan Qiu

    As the major nutritional component in soybean seeds storage proteins are initially synthesized on the endoplasmic reticulum as precursors and subsequently delivered to protein storage vacuoles (PSVs) via the Golgi-mediated pathway where they are converted into mature subunits and accumulated. However, the molecular machinery required for storage protein trafficking in soybean remains largely unknown. In this study, we cloned the sole soybean homolog of OsGPA3 that encodes a plant-unique kelch-repeat regulator of post-Golgi vesicular traffic for rice storage protein sorting. A complementation test showed that GmGPA3 could rescue the rice gpa3 mutant. Biochemical assays verified that GmGPA3 physically interacts with GmRab5 and its guanine exchange factor (GEF) GmVPS9. Expression of GmGPA3 had no obvious effect on the GEF activity of GmVPS9 toward GmRab5a. Notably, knock-down of GmGPA3 disrupted the trafficking of mmRFP-CT10 (an artificial cargo destined for PSVs) in developing soybean cotyledons. We identified two putative GmGPA3 interacting partners (GmGMG3 and GmGMG11) by screening a yeast cDNA library. Overexpression of GmGPA3 or GmGMG3 caused shrunken cotyledon cells. Our overall results suggested that GmGPA3 plays an important role in cell growth and development, in addition to its conserved role in mediating storage protein trafficking in soybean cotyledons.

    更新日期:2020-01-24
  • Changes in maximum daily runoff depth and suspended sediment yield on the Loess Plateau, China
    J. Hydrol. (IF 4.405) Pub Date : 2020-01-24
    Haiyan Zheng; Chiyuan Miao; Dongxian Kong; Jingwen Wu; Rui Zhou

    The maximum river flow is of important reference significance to flood disaster prevention on the Loess Plateau of central China. However, due to the lack of hydrological data, previous studies have rarely explored spatiotemporal changes in the annual maximum daily runoff depth (Hmax) and annual maximum daily suspended sediment yield (SSYmax) of rivers in this region. This study uses daily discharge data and daily sediment concentration data from 104 hydrological stations on the plateau to compare the Hmax and the SSYmax during period P1 (1971–1987) and period P2 (2008–2016). The results show that 66% of stations exhibited a significant decline in multi-year mean Hmax from P1 to P2 (p < 0.05). However, the multi-year mean SSYmax showed more widespread changes, with 77% of stations seeing a significant decline (p < 0.05). And on average, the runoff on the day of Hmax contributed 6.6% and 5.8% of the annual runoff during P1 and P2, respectively; by contrast, SSYmax contributed 27.9% and 33.5%, respectively, to the total annual suspended sediment yield in P1 and P2. Analyses using Spearman’s rank correlation coefficient indicate that the spatial distribution of Hmax has larger variability than SSYmax during both P1 and P2 and that the spatial distribution pattern of SSYmax during P2 is more unstable than during P1. We found that the suspended sediment concentration (SSC) on the day that Hmax occurs (SSChmax) remained relatively stable for most stations studied within the loess gullied-hilly area across the Loess Plateau, but the stable SSChmax value during P1 differed from the value during P2. We conclude that human activities (e.g., afforestation, terracing, and construction of check dams) may be the cause of the differing SSC values during peak discharge between the two periods. We also found that the average percentage of years in which Hmax and SSYmax occurred on the same day on the plateau was 55%. Many factors can lead to Hmax and SSYmax happening asynchronously, such as heavy runoff events lasting several consecutive days, the characteristics of a particular basin, and the influence of human activities. These results provide information that will be useful for understanding how to manage extreme hydrological events on the Loess Plateau.

    更新日期:2020-01-24
  • Discussion of “Comparative assessment of time series and artificial intelligence models to estimate monthly streamflow: A local and external data analysis approach” by Saeid Mehdizadeh, Farshad Fathian, Mir Jafar Sadegh Safari and Jan F. Adamowski
    J. Hydrol. (IF 4.405) Pub Date : 2020-01-24
    Isa Ebtehaj; Mohammad Zeynoddin; Hossein Bonakdari

    This discussion extends published findings on the use of artificial intelligence models for time series modeling/monthly streamflow forecasting at the Port Elgin station on the Saugeen River, Canada. Published results are applied and run in autoregressive (AR) and moving average (MA) models as well as hybrids of these with autoregressive conditional heteroscedasticity (ARCH), namely AR-ARCH and MA-ARCH. The hybrid solutions are concluded to be superior to both linear and nonlinear modeling approaches. However, common nonlinear methods including neural networks have a recognized defect in time series forecasting known as “inappropriate time series modeling inputs”. The present study addresses this significant source of error in nonlinear modeling by referring to time series components via suitable time series preprocessing. Of particular interest in this discussion provides the novel vision for time series modeling using nonlinear approaches. The nature of the hydrological variables in time series modeling has great impact on the predicted output and should thus be considered in the modeling procedure. An appropriate preprocessing technique must also be considered carefully in order to attain reliable nonlinear modeling results.

    更新日期:2020-01-24
  • Seasonal drivers of geographically isolated wetland hydrology in a low-gradient, Coastal Plain landscape
    J. Hydrol. (IF 4.405) Pub Date : 2020-01-24
    Sanghcul Lee; Gregory W. McCarty; Glenn E. Moglen; Megan W. Lang; C. Nathan Jones; Margaret Palmer; In-Young Yeo; Martha Anderson; Ali M. Sadeghi; Martin C. Rabenhorst

    Geographically isolated wetlands (GIWs) provide a portfolio of ecosystem services in low-gradient, Coastal Plain landscapes. Understanding how GIWs influence downstream waters is becoming increasingly important for conservation and management of these unique and important wetland ecosystems. Climatic conditions are known to be key drivers of water budgets at both individual GIW and landscape scales; however differences in hydrologic response across these scales may provide insights into how GIWs influence downstream waters. In this study, we use a combination of GIW water level, gaged streamflow, and climatic data to explore linkages between seasonal climatic drivers, GIW hydrology, and downstream discharges within the Coastal Plain of the Chesapeake Bay watershed. We first examine water balance components at the larger watershed scale, where climatic drivers result in an energy-limited wet season from December to May and a water-limited dry season from June to November. We compare long-term water levels of three GIWs with downstream discharges. GIW water level and downstream discharges are correlated at seasonal (R2: 0.52 – 0.60) and daily (R2: 0.52 – 0.76) time steps. However, during dry seasons, GIW water level receded at a faster rate than downstream discharges, highlighting the influence of evapotranspiration on surface and shallow subsurface water storage. Conversely during wet seasons, GIW water level receded slower than downstream discharges, highlighting a potential period for surface water connectivity between GIWs and downstream discharges. Cumulatively, these findings quantify the impact of seasonal climatic drivers on GIW hydrology and connectivity to downstream waters.

    更新日期:2020-01-24
  • 更新日期:2020-01-24
  • Water transfer imposes hydrochemical impacts on groundwater by altering the interaction of groundwater and surface water
    J. Hydrol. (IF 4.405) Pub Date : 2020-01-24
    Ruiqiang Yuan; Meng Wang; Shiqin Wang; Xianfang Song

    How the water transfer imposes impacts on the groundwater in the water-receiving area is still unknown. Here, we employed hydrometric observations, hydrogeochemical analyses and data analysis methods to address this issue, taking one of the Yellow River water transfer project of China for example. We found that the interaction between river and groundwater is totally changed by the water transfer and the impact of the water transfer on groundwater is confined by the high stream gradient. With the water transfer, the natural annual pattern of rainy-season high river flow is inversed with low flow in rainy seasons and high flow during the water transfer. Moreover, the river stage is always higher than the groundwater level throughout the year. The usual bidirectional river–groundwater hydraulic gradient is altered to be a gradient always away from the river. The groundwater directly connects with the river water. The regime of groundwater level follows the change of the river stage, even in the valley side. A long-term standing groundwater mound is formed within the riparian zone due to the continuous recharge from the water-receiving river. The transferred Yellow River water is hydrochemically featured by high EC value and concentrations of Na+ and Cl-. The hydrochemical features of the water-receiving river are obviously changed by the transferred Yellow River water. The hydrochemical impact of the river on the groundwater is mainly confined to the riparian zone and some low-reach transections, despite of the dominated control of the river on the valley groundwater table. The high stream gradient trends to produce the downstream groundwater flow and hinder the lateral groundwater flow from river to valley sides in the upper reaches, responsible for the confined impact on groundwater. Our study highlights that the stream gradient could obviously influence the river water and groundwater interaction promoting or confining the impact of river water on groundwater.

    更新日期:2020-01-24
  • Understanding dynamics of groundwater flows in the Mississippi River Delta
    J. Hydrol. (IF 4.405) Pub Date : 2020-01-24
    An Li; Frank T.-C. Tsai

    Groundwater is a major component of the water cycle in the river-deltaic environment. However, the dynamics of groundwater flows in the river delta remains an open question owing to the complexities in the hydrologic and geological settings. This study employed a hydrogeological modeling approach to investigate groundwater dynamics in the Mississippi River Delta (MRD). A detailed groundwater model for the top 50 m of the MRD was constructed from the Head of Passes (RK 0) to Jesuits Bend (RK 108) using geotechnical borings and topobathymetric maps. Mississippi River stage and tide stage data were the key hydrologic data, which reflect hydrologic forcing (floods, storms, and hurricanes) to the groundwater system. By investigating the 2012 hydrologic year, the study presents several intriguing findings. Groundwater discharge and recharge rates to the river and surrounding bays were estimated 3 or 4 orders of magnitude smaller than Mississippi River discharge rate to the Gulf of Mexico. Nevertheless, the model showed strong surface-groundwater interactions controlled by local hydraulic gradient at the river and bay interfaces during severe hydrologic events. Specifically, during Hurricane Isaac pore water pressure was estimated 4-6 times higher than the normal condition and peak groundwater recharge was reached due to storm surges. Peak groundwater discharge sharply occurred a few days later after the hurricane passed. The study found such a dramatic change in surface-groundwater interactions was due to quick surface water receding and delayed groundwater response. As a consequence, more areas are likely exposed to harmful high pore water pressure and low factor of safety condition, which would destabilize sediments, enhance erosion, and compromise safety of coastal infrastructures such as the ring levees.

    更新日期:2020-01-24
  • Interaction of mangrove surface coverage and groundwater inputs on the temperature and water level near Tulum, Quintana Roo, Mexico: observations and modelling
    J. Hydrol. (IF 4.405) Pub Date : 2020-01-23
    Aaron Coutino; Marek Stastna; Eduard G. Reinhardt

    We report on a series of high resolution sensor measurements from within the Yax Chen cave system near the city of Tulum, Quintana Roo, Mexico and a box model of mangrove-groundwater interactions. The sensors were positioned in the cave following a transect moving inland. Conductivity, water pressure and temperature data were collected at 30 minute intervals for a span of two years. Temperature, water level, and conductivity records showed a response to large rainfall events (Hurricane Nate in October 2017 and Topical Storm Philippe in November 2017) which coincided with differences in surficial vegetation. Groundwater with areas of mangrove coverage showed an input of warm mangrove water as the water level receded to pre-rainfall levels and, the temperature effect was not observed in areas dominated by an upland forested terrain. A model of the groundwater-mangrove interaction was developed with an on-off switch for the flow of mangrove water into the groundwater system when the rainfall is sufficiently large. The model reproduces the observed timing difference in the temperature and conductivity response, and matches the field data during rainfall events. This model shows the effectiveness of simple box models in understanding a complicated geophysical processes and provides quantitative support to this previously hypothesized groundwater interaction.

    更新日期:2020-01-24
  • Susceptibility of foodborne pathogens to sanitizers in produce rinse water and potential induction of viable but non-culturable state
    Food Control (IF 4.248) Pub Date : 2020-01-24
    Ganyu Gu; Samantha Bolten; Joseph Mowery; Yaguang Luo; Connor Gulbronson; Xiangwu Nou

    Chemical sanitizers are commonly used for fresh produce washing to reduce potential presence of foodborne pathogens and spoilage bacteria, and to prevent cross-contamination. In this study, we evaluated the susceptibility of foodborne pathogens, including Shiga-toxigenic Escherichia coli, Salmonella enterica, and Listeria monocytogenes, to free chlorine (FC) and peracetic acid (PAA) in spinach and romaine lettuce rinsates as simulated leafy green wash water. All inoculated pathogens exhibited notably enhanced tolerance (over 2 log of increased recovery) to FC, but not to PAA, when treated in fresh produce rinsates in comparison to that in sterile water. Both FC and PAA effectively inactivated the inoculated foodborne pathogens, rendering them undetectable after 30 s exposure to 10 mg/L FC or 30 mg/L PAA, by selective plating or non-selective enrichment. However, potentially viable cells for all the inoculated foodborne pathogens were detected by PMA-qPCR, especially in wash water samples treated with PAA at concentrations up to 50 mg/L. While laser confocal microscopy after differential staining suggested significant presence of viable but non-culturable (VBNC) populations in PAA treated wash water samples, resuscitation in vitro of the potential VBNC cells was not achieved. This study provides scientific data to better understand the risks of potential VBNC foodborne pathogens during fresh produce washing.

    更新日期:2020-01-24
  • Labeling compliance and species authentication of fish fillets sold at grocery stores in Southern California
    Food Control (IF 4.248) Pub Date : 2020-01-24
    Priscila Liou; Angela Banda; Rachel B. Isaacs; Rosalee S. Hellberg

    Seafood mislabeling has numerous consequences, including economic deception and food safety risks. The focus of this study was to investigate fish species labeling, use of acceptable market names, and Country of Origin Labeling (COOL) compliance for fresh fish fillets sold at grocery store seafood counters in Southern California. A total of 120 fillets representing 16 different categories of fish were collected from 30 Perishable Agricultural Commodities Act (PACA)-listed grocery stores. Each sample underwent DNA barcoding to identify the species. Acceptable market names were confirmed using the FDA Seafood List. Samples were determined to be compliant with COOL if both the country of origin and the production method were declared in accordance with regulatory requirements. Species substitution was detected in 16 of the 120 samples (13.3%) and unacceptable market names were observed for an additional 11 samples (9.2%). The highest rates of species substitution were recorded for snapper (3/3), yellowtail (2/4), halibut (4/10), cod (3/10), and bass (2/7). COOL noncompliance was observed for 28 samples (23.3%): the country of origin was missing for 15 samples, production method was missing for 9 samples, and 4 samples were missing both. When all forms of mislabeling were considered, 47 of the 120 samples (39.2%) had at least one labeling error. The majority of grocery stores (25/30) had one or more samples with a mislabeling error. This study revealed species mislabeling as a continuous concern in the seafood industry, especially with higher-valued species. Furthermore, the lack of COOL compliance among retailers is concerning and suggests a need for increased focus on these regulations.

    更新日期:2020-01-24
  • Risk assessment of aflatoxins and selected heavy metals through intake of branded and non-branded spices collected from the markets of Multan city of Pakistan
    Food Control (IF 4.248) Pub Date : 2020-01-23
    Saeed Akhtar; Muhammad Riaz; Iqra Naeem; Yun Yun Gong; Amir Ismail; Majid Hussain; Kashif Akram

    Spices are an essential part of our food preparations and are considered a potential source of health-protective components. However, spices may also contain some toxic substances primarily aflatoxins and heavy metals. This study aimed to quantify the level of total aflatoxins and three most toxic heavy metals i.e. lead (Pb), arsenic (As) and cadmium (Cd) in commercially available non-branded and branded spices. Furthermore, risk assessment through aflatoxins and heavy metals was performed by computing the values of Margin of Exposure (MOE) and Total Hazard Quotient (THQ), respectively. The concentration of aflatoxins was recorded higher in non-branded spices while heavy metals especially Pb was recorded higher in branded spices. MOE values for aflatoxins through spices consumption indicated that all age group of people were consuming aflatoxins above the threshold level. The THQ values for heavy metals toxicity assessment were found within the acceptable ranges. Females, especially above 24 years of age, were found at more risk as compared to male, due to their higher intake rate of spices.

    更新日期:2020-01-24
Contents have been reproduced by permission of the publishers.
导出
全部期刊列表>>
2020新春特辑
限时免费阅读临床医学内容
ACS材料视界
科学报告最新纳米科学与技术研究
清华大学化学系段昊泓
自然科研论文编辑服务
加州大学洛杉矶分校
上海纽约大学William Glover
南开大学化学院周其林
课题组网站
X-MOL
北京大学分子工程苏南研究院
华东师范大学分子机器及功能材料
中山大学化学工程与技术学院
试剂库存
天合科研
down
wechat
bug