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  • Early Cenozoic evolution of the latitudinal diversity gradient
    Earth Sci. Rev. (IF 9.530) Pub Date : 2020-01-17
    J. Alistair Crame

    We are beginning to appreciate that the huge radiations of both marine and terrestrial taxa in the aftermath of the K/Pg mass extinction event were concentrated largely, but not exclusively, in the low-latitude and tropical regions. This in turn means that significant latitudinal diversity gradients were developed well before the onset of global cooling at the Eocene/Oligocene boundary. Net rates of evolutionary radiations were significantly higher through the Early Paleocene – Middle Eocene interval (i.e. ~62–42 Ma) in the tropics than at the poles but this may be due as much to their retardation in the latter regions as to their acceleration in the former. At least in the marine realm, polar assemblages are characterised by the phenomenon of high dominance/low evenness, and it is thought likely that this is due to the extreme seasonality of primary production at the base of the food chain. Many modern polar marine organisms are de facto trophic generalists and occupy significantly broader ecological niches than their tropical counterparts. Although we cannot dismiss the roles of both temperature and area in promoting tropical diversity, it could well be that LDGs are just as much the product of a latitudinal gradient in the seasonality of primary productivity. Such a gradient would have operated in both greenhouse and icehouse worlds.

    更新日期:2020-01-17
  • Establishing a Core Outcome Set for Peritoneal Dialysis: Report of the SONG-PD (Standardized Outcomes in Nephrology–Peritoneal Dialysis) Consensus Workshop
    Am. J. Kidney Dis. (IF 6.653) Pub Date : 2020-01-16
    Karine E. Manera; David W. Johnson; Jonathan C. Craig; Jenny I. Shen; Talia Gutman; Yeoungjee Cho; Angela Yee-Moon Wang; Edwina A. Brown; Gillian Brunier; Jie Dong; Tony Dunning; Rajnish Mehrotra; Saraladevi Naicker; Roberto Pecoits-Filho; Jeffrey Perl; Martin Wilkie; Allison Tong

    Outcomes reported in randomized controlled trials in peritoneal dialysis (PD) are diverse, are measured inconsistently, and may not be important to patients, families, and clinicians. The Standardized Outcomes in Nephrology–Peritoneal Dialysis (SONG-PD) initiative aims to establish a core outcome set for trials in PD based on the shared priorities of all stakeholders. We convened an international SONG-PD stakeholder consensus workshop in May 2018 in Vancouver, Canada. Nineteen patients/caregivers and 51 health professionals attended. Participants discussed core outcome domains and implementation in trials in PD. Four themes relating to the formation of core outcome domains were identified: life participation as a main goal of PD, impact of fatigue, empowerment for preparation and planning, and separation of contributing factors from core factors. Considerations for implementation were identified: standardizing patient-reported outcomes, requiring a validated and feasible measure, simplicity of binary outcomes, responsiveness to interventions, and using positive terminology. All stakeholders supported inclusion of PD-related infection, cardiovascular disease, mortality, technique survival, and life participation as the core outcome domains for PD.

    更新日期:2020-01-17
  • A Self-management Approach for Dietary Sodium Restriction in Patients With CKD: A Randomized Controlled Trial
    Am. J. Kidney Dis. (IF 6.653) Pub Date : 2020-01-16
    Jelmer K. Humalda; Gerald Klaassen; Hanne de Vries; Yvette Meuleman; Lara C. Verschuur; Elisabeth J.M. Straathof; Gozewijn D. Laverman; Willem Jan W. Bos; Paul J.M. van der Boog; Karin M. Vermeulen; Olivier A. Blanson Henkemans; Wilma Otten; Martin H. de Borst; Sandra van Dijk; Gerjan J. Navis

    Rationale & Objective Patients with chronic kidney disease (CKD) are particularly sensitive to dietary sodium. We evaluated a self-management approach for dietary sodium restriction in patients with CKD. Study Design Randomized controlled trial. Setting & Participants Nephrology outpatient clinics in 4 Dutch hospitals. 99 adults with CKD stages 1 to 4 or a functioning (estimated glomerular filtration rate ≥ 25 mL/min/1.73 m2) kidney transplant, hypertension, and sodium intake >130 mmol/d. Intervention Routine care was compared with routine care plus a web-based self-management intervention including individual e-coaching and group meetings implemented over a 3-month intervention period, followed by e-coaching over a 6-month maintenance period. Outcomes Primary outcomes were sodium excretion after the 3-month intervention and after the 6-month maintenance period. Secondary outcomes were blood pressure, proteinuria, costs, quality of life, self-management skills, and barriers and facilitators for implementation. Results Baseline estimated glomerular filtration rate was 55.0 ± 22.0 mL/min/1.73 m2. During the intervention period, sodium excretion decreased in the intervention group from 188 ± 8 (SE) to 148 ± 8 mmol/d (P < 0.001), but did not change significantly in the control group. At 3 months, mean sodium excretion was 24.8 (95% CI, 0.1-49.6) mmol/d lower in the intervention group (P = 0.049). At 3 months, systolic blood pressure (SBP) decreased in the intervention group from 140 ± 3 to 132 ± 3 mm Hg (P < 0.001), but was unchanged in the control group. Mean difference in SBP across groups was −4.7 (95% CI, −10.7 to 1.3) mm Hg (P = 0.1). During the maintenance phase, sodium excretion increased in the intervention group, but remained lower than at baseline at 160 ± 8 mmol/d (P = 0.01), while it decreased in the control group from 174 ± 9 at the end of the intervention period to 154 ± 9 mmol/d (P = 0.001). Consequently, no difference in sodium excretion between groups was observed after the maintenance phase. There was no difference in SBP between groups after the maintenance phase. Limitations Limited power, postrandomization loss to follow-up, Hawthorne effect, lack of dietary data, short-term follow-up. Conclusions A coaching intervention reduced sodium intake at 3 months. Efficacy during the maintenance phase was diminished, possibly due to inadvertent adoption of the intervention by the control group. Funding Grant funding from the Netherlands Organization for Health Research and Development and the Dutch Kidney Foundation. Trial registration Registered at ClinicalTrials.gov with study number NCT02132013.

    更新日期:2020-01-17
  • Circadian modulation of motivation in mice
    Behav. Brain Res. (IF 2.770) Pub Date : 2020-01-17
    Julieta Acosta; Ivana L. Bussi; Macarena Esquivel; Christian Höcht; Diego A. Golombek; Patricia V. Agostino

    Most living organisms have a circadian timing system adapted to optimize the daily rhythm of exposure to the environment. This circadian system modulates several behavioral and physiological processes, including the response to natural and drug rewards. Food is the most potent natural reward across species. Food-seeking is known to be mediated by dopaminergic and serotonergic transmission in cortico-limbic pathways. In the present work, we show evidence of a circadian modulation of motivation for food reward in young (4-months old) and aged (over 1.5 years old) C57BL/6 mice. Motivation was assayed through the progressive ratio (PR) schedule. Mice under a 12:12 light/dark (LD) cycle exhibited a diurnal rhythm in motivation, becoming more motivated during the night, coincident with their active phase. This rhythm was also evident under constant dark conditions, indicating the endogenous nature of this modulation. However, circadian arrhythmicity induced by chronic exposure to constant light conditions impaired the performance in the task causing low motivation levels. Furthermore, the day/night difference in motivation was also evident even without caloric restriction when using a palatable reward. All these results were found to be unaffected by aging. Taken together, our results indicate that motivation for food reward is regulated in a circadian manner, independent of the nutritional status and the nature of the reward, and that this rhythmic modulation is not affected by aging. These results may contribute to improve treatment related to psychiatric disorders or drugs of abuse, taking into account potential mechanisms of circadian modulation of motivational states.

    更新日期:2020-01-17
  • Effect of Brightness of Visual Stimuli on EEG Signals
    Behav. Brain Res. (IF 2.770) Pub Date : 2020-01-17
    Kübra Eroğlu; Temel Kayıkçıoğlu; Onur Osman

    The aim of this study was to examine brightness effect, which is the perceptual property of visual stimuli, on brain responses obtained during visual processing of these stimuli. For this purpose, brain responses of the brain to changes in brightness were explored comparatively using different emotional images (pleasant, unpleasant and neutral) with different luminance levels. In the study, electroencephalography recordings from 12 different electrode sites of 31 healthy participants were used. The power spectra obtained from the analysis of the recordings using short time Fourier transform were analyzed, and a statistical analysis was performed on features extracted from these power spectra. Statistical findings were compared with those obtained from behavioral data. The results showed that the brightness of visual stimuli affected the power of brain responses depending on frequency, time and location. According to the statistically verified findings, the increase in the brightness of pleasant and neutral images increased the average power of responses in the parietal and occipital regions whereas the increase in the brightness of unpleasant images decreased the average power of responses in these regions. Moreover, the statistical results obtained for unpleasant images were found to be in accordance with the behavioral data. The results revealed that the brightness of visual stimuli could be represented by changing the activity power of the brain cortex. The findings emphasized that the brightness of visual stimuli should be viewed as an important parameter in studies using emotional image techniques such as image classification, emotion evaluation and neuro-marketing.

    更新日期:2020-01-17
  • Transcranial direct current stimulation improves risky decision making in women but not in men: a sham-controlled study
    Behav. Brain Res. (IF 2.770) Pub Date : 2020-01-17
    J.J. León; A. Sánchez-Kuhn; P. Fernández-Martín; M.A. Páez-Pérez; C. Thomas; A. Datta; F. Sánchez-Santed; P Flores

    Behavioral and anatomical sex-related differences have been traditionally found in decision-making processes assessed by Iowa Gambling Task (IGT). So far, the administration of transcranial direct current stimulation (tDCS) over orbitofrontal regions has shown an enhancing effect over decision-making. However, it is unknown whether there is a sex-dependent effect of stimulation in decision-making, a key question considering previous differences between men and women in IGT and the influence of individual differences in tDCS. The present study examines, at first time, the interaction between sex and tDCS in decision-making. For that aim, in a first experimental phase, ninety-two healthy participants performed the IGT. In a second phase, sixty-one participants received 20 min of anodal or sham tDCS over the right orbitofrontal cortex (rOFC) in a single-session pre-post sham-controlled study. To support the focality of the montage, a Stop Signal Task (SST) was used as a control task and also a numerical simulation of current flow distribution was performed. According to literature, in the first phase, results showed that men outperformed women in the IGT. In the second phase, the stimulation varied the IGT performance according to a sex specific manner: anodal tDCS increased the IGT performance in women, while in men; the stimulation did not produce any effect. Results were mediated by sex-specific morphological differences. These results highlight the necessity to consider the interaction of sex with the effect of the stimulation in future tDCS protocols, specifically in future clinical studies.

    更新日期:2020-01-17
  • Corrosion inhibition of copper in 0.5 M NaCl solutions by aqueous and hydrolysis acid extracts of olive leaf
    J. Electroanal. Chem. (IF 3.218) Pub Date : 2020-01-16
    Philippe Refait; Chahla Rahal; Mohamed Masmoudi

    Aqueous extracts and acid hydrolysates from olive leaf, rich in various phenolic compounds, were prepared under different experimental conditions. Their inhibitive action on the corrosion of copper in 0.5 M NaCl solutions was studied by electrochemical impedance spectroscopy and voltammetry. High performance liquid chromatography showed that the extracts were rich in oleuropeine, hydroxytyrosol, and elenolic acid. The acid hydrolysis extracts obtained at high temperature mainly contained hydroxytyrosol and elenolic acid and led to the highest inhibition efficiency (95%). The polarization curves were modelled on a large potential range (e.g. from −500 mV to −100 mV/SCE) using electrochemical kinetic laws to obtain a maximum of reliable information. Elenolic acid and oleuropein acted as cathodic-type corrosion inhibitors.

    更新日期:2020-01-17
  • Voltammetric responses of porous Co3O4 spinels supported on MOF-derived carbons: Effects of porous volume on dopamine diffusion processes
    J. Electroanal. Chem. (IF 3.218) Pub Date : 2020-01-16
    Lesego Gaolatlhe; Rasmita Barik; Sekhar C. Ray; Kenneth I. Ozoemena

    The voltammetric responses of novel porous Co3O4 spinel materials supported on MOF-derived carbons (MOFDC) have been described. The electrocatalysts were prepared using microwave-assisted hydrothermal methods, obtaining both Rich- and Starved-Co3O4 MOF-derived carbons (i.e., R-Co3O4@MOFDC and S-Co3O4@MOFDC). The physicochemical properties of the porous electrode materials were thoroughly characterized via XRD, SEM, BET, EDX and XPS. The R-Co3O4@MOFDC shows low specific surface area and small pore volume, while the S-Co3O4@MOFDC is characterized with high specific surface area and large pore volume, about four times larger than the former. Using dopamine as a model analyte, the study shows the voltammetric response towards the detection of dopamine detection to be strongly dependent on the diffusive and adsorptive/capacitive modes: R-Co3O4@MOFDC exhibits high diffusive mode with enhanced dopamine detection, while S-Co3O4@MOFDC exhibits high adsorptive mode and relatively poor dopamine detection. The overall voltammetric response is interpreted in terms of fast semi-infinite planar diffusion of dopamine towards the electrode surface and the inhibition of the thin layer diffusion process due to the depletion of the electrolyte trapped within pores (leading to disadvantageous adsorption). At higher concentrations (DA > 3 mM) the adsorption behaviour at these porous electrode follows the Langmuir adsorption isotherm with adsorption equilibrium constant (β) of (1.96 ± 0.16) × 105 and (2.53 ± 0.20) × 105 M−1 for R-Co3O4@MOFDC and S-Co3O4@MOFDC, respectively. This study opens doors for rational design and development of transition metal-based MOFDC for the detection of biomolecules.

    更新日期:2020-01-17
  • Comments on the paper “Modelling the growth of a single centre”, by M.Y. Abyaneh, M. Fleischmann, and M.H. Mehrabi, published in the Journal of Electroanalytical Chemistry, 834,114–123 (2019).
    J. Electroanal. Chem. (IF 3.218) Pub Date : 2020-01-16
    Stephen Fletcher

    In a recent paper in this journal, M.Y. Abyaneh, M. Fleischmann, and M.H. Mehrabi claimed to have developed a novel approach towards the derivation of the current-time profile of a single hemispherical crystal growing under mixed kinetic-diffusion control. The authors also claimed to have derived a number of asymptotic results that differ significantly from the standard results in the scientific literature. In a radical re-appraisal of older publications, they reached the startling conclusion that “none of the previous works are capable of providing correct solutions even for the steady-state approximation”. In this short communication, we dispute this claim. In particular, we identify multiple incorrect boundary conditions in the work of Abyaneh et al. which fatally compromise their analysis.

    更新日期:2020-01-17
  • Highly dispersed, single-site copper catalysts for the electroreduction of CO2 to methane
    J. Electroanal. Chem. (IF 3.218) Pub Date : 2020-01-16
    Teng Zhang; Sumit Verma; Soojeong Kim; Timothy T. Fister; Paul J.A. Kenis; Andrew A. Gewirth
    更新日期:2020-01-17
  • Design of porous calcium phosphate based gel polymer electrolyte for Quasi-solid state sodium ion battery
    J. Electroanal. Chem. (IF 3.218) Pub Date : 2020-01-16
    Ajay Piriya Vijaya Kumar Saroja; R. Arunkumar; Bhaskar Chandra Moharana; M. Kamaraj; S. Ramaprabhu

    The design of a suitable separator is an effective approach to enhance the performance as well as the safety of a rechargeable battery. The conventional glass fiber separator has electrolyte leakage due to the random distribution of pores in the structure. The design of a gel polymer electrolyte with phosphorus containing compound is considered to be safer for the operation of a rechargeable sodium ion battery. Hence, we have developed a gel polymer using hydroxyapatite, a calcium phosphate-based compound in poly (vinylidene fluoride-hexafluoropropylene)-poly (butyl methacrylate) blend membrane by a simple solution casting technique. The developed membrane has an ionic conductivity of 1.086 × 10−3 S cm−1 with an electrochemical stability of up to 4.9 V, good porosity and electrolyte uptake, thereby making it a promising electrolyte to be used in a rechargeable sodium ion battery. To demonstrate its feasibility, the electrochemical properties of Na3V2(PO4)3/C are investigated using the prepared gel polymer electrolyte. The sodium ion cell using gel polymer electrolyte exhibits a specific capacity of 97 mAh g−1 at 4 C which is about 33.5% enhancement in specific capacity when compared to the cell with the conventional glass fiber membrane. This study illustrates the feasibility of using gel polymer electrolyte as a replacement to the existing glass fiber separator.

    更新日期:2020-01-17
  • Analytical time-stepping solution of the discretized population balance equation
    Comput. Chem. Eng. (IF 3.334) Pub Date : 2020-01-17
    Mohamed Ali Jama; Wenli Zhao; Waqar Ahmed; Antonio Buffo; Ville Alopaeus

    The prediction of the particle-size distribution (PSD) of the particulate systems in chemical engineering is very important in a variety of different contexts, such as parameter identification, troubleshooting, process control, design, product quality, production economics etc. The time evolution of the PSD can be evaluated by means of the population balance equation (PBE), which is a complex integro-differential equation, whose solution in practical cases always requires sophisticated numerical methods that may be computationally tedious. In this work, we propose a novel technique that tackles this issue by using an analytical time-stepping procedure (ATS) to resolve the PSD time dependency. The ATS is an explicit time integrator, taking advantage of the linear or almost linear time dependency of the discretized population balance equation. Thus, linear approximation of the source term is a precondition for the ATS simulations. The presented technique is compared with a standard variable step time integrator (MATLAB ODE15s stiff solver), for practical examples e.g. emulsion, ageing cellulose process, cooling crystallization, reactive dissolution, and liquid-liquid extraction. The results show that this advancing in time procedure is accurate for all tested practical examples, allowing reproducing the same results given by standard time integrators in a fraction of the computational time.

    更新日期:2020-01-17
  • Effect of morphine exposure on novel object memory of the offspring: the role of histone H3 and ΔFosB
    Brain Res. Bull. (IF 3.103) Pub Date : 2020-01-17
    Mitra-Sadat Sadat-Shirazi; Pardis Asgari; Sarah Mahboubi; Setareh Nouri Zadeh-Tehrani; Ghorbangol Ashabi; Kiyana Rohbani; Saba Sabzevari; Haniyeh Soltani; Solmaz Khalifeh; Mohammad-Reza Zarrindast

    It has been demonstrated that alteration in histone acetylation in the regions of the brain involved in the reward which may have an important role in morphine addiction. It is well established that epigenetic changes prior to birth influence the function and development of the brain. The current study was designed to evaluate changes in novel object memory, histone acetylation and ΔFosB in the brain of the offspring of morphine-withdrawn parents. Male and female Wistar rats received morphine orally for 21 following days. After ten days of abstinent, they were prepared for mating. The male offspring of the first parturition were euthanized on postnatal days 5, 21, 30 and 60. The novel object recognition (NOR) test was performed on adult male offspring. The amount of acetylated histone H3 and ΔFosB were evaluated in the prefrontal cortex (PFC) and hippocampus using western blotting. Obtained results indicated that the discrimination index in the NOR test was decreased in the offspring of morphine-withdrawn parents as compared with morphine-naïve offspring. In addition, the level of acetylated histone H3 was decreased in the PFC and hippocampus in the offspring of morphine-withdrawn parents during lifetime (postnatal days 5,21,30 and 60). In the case of ΔFosB, it also decreased in these regions in the morphine-withdrawn offspring. These results demonstrated that parental morphine exposure affects NOR memory, and decreased the level of histone H3 acetylation and ΔFosB in the PFC and hippocampus. Taken together, the effect of morphine might be transmitted to the next generation even after stop consuming morphine.

    更新日期:2020-01-17
  • A New Peptide-based Chemosensor for Selective Imaging of Copper ion and Hydrogen Sulfide in Living Cells
    Microchem. J. (IF 3.206) Pub Date : 2020-01-17
    Chaowei Hao; Yongxin Li; Baomin Fan; Guangzhi Zeng; Danni Zhang; Zhaoxiang Bian; Jiang Wu
    更新日期:2020-01-17
  • Efficient development of a magnetic molecularly imprinted polymer for selective determination of trimethoprim and sulfamethoxazole in milk
    Microchem. J. (IF 3.206) Pub Date : 2020-01-16
    Laíse Aparecida Fonseca Dinali; Hanna Leijoto de Oliveira; Leila Suleimara Teixeira; Anny Talita Maria da Silva; Kaíque A D'Oliveira; Alexandre Cuin; Keyller Bastos Borges

    A molecularly imprinted polymer was synthesized on the surface of magnetic nanoparticles for subsequent application in the extraction of trimethoprim (TMT) and sulfamethoxazole (SMX) residues in bovine milk. The magnetic polymer was suitably characterized and demonstrated high stability and optimum adsorption capacity under the conditions of analysis. MMIP was used in the preparation of milk samples by the magnetic solid phase extraction technique whose optimized parameters were: sample volume, elution solvent and its volume, amount of adsorbent, stirring time, and pH of the sample. The relative recoveries of analytes were 98.66 ± 5.59 % and 75.57 ± 0.72 % for TMT and SMX, respectively. The method developed was linear in the range of concentration of 0.05–20 µg mL−1 with correlation coefficients of 0.997 and 0.994 for TMT and SMX, respectively. It was also demonstrated satisfactory accuracy and precision, as well as adequate robustness and good drugs stability in the matrix. The method was applied satisfactorily in real milk samples contaminated with residues of these antibiotics.

    更新日期:2020-01-17
  • Engineering a label- and enzyme-free detection of HIV-DNA on a cyclic DNA self-assembling strategy using G-triplexes as the signal reporter
    Microchem. J. (IF 3.206) Pub Date : 2020-01-16
    Yunpeng Han; Rong Zou; Ling Xiang; Chunyan Chen; Changqun Cai

    An efficient amplification strategy based on the G-triplex DNA structure was developed for label- and enzyme-free fluorescence detection of human immunodeficiency virus (HIV) DNA. In this system, three hairpin molecules (H1, H2, and H3) were used to detect the target and amplify the signal. Fluorescence enhancement was achieved by producing more G-triplexes to bind with Thioflavine T. A detection limit of 33 pM with good linearity in the range from 400 pM to 110 nM was observed. This method avoided using of enzyme and cumbersome labeling procedures and was relatively superior to previous G-quadruplex-based approaches, which often encounter some difficulties in control and excitation. Moreover, the application for detecting HIV-DNA in biological fluids indicates that further applications for clinical diagnosis are expected.

    更新日期:2020-01-17
  • Multivariate optimization and validation of a new procedure for simultaneous determination of folic acid and folinic acid based on enhancement effect of n-dodecylpyridinium chloride
    Microchem. J. (IF 3.206) Pub Date : 2020-01-16
    Mahdi Mollaei; Sayed Mehdi Ghoreishi; Asma Khoobi

    The present study is a first report about of an electrochemical sensor for simultaneous determination of folic acid (FA) and calcium folinate (CF) as a cationic surfactant. Also, the work is a first successful application of n-dodecylpyridinium chloride (DPC) as a modifier in voltammetric simultaneous measurements. This study is based on the adsorption of cationic surfactants at the surface of a carbon paste electrode (CPE) to improve the electrochemical response of the tow analytes. The enhancement effect of DPC is compared with CTAB by differential pulse voltammetry (DPV) technique and DPC shows the better results as a modifier. Other novelty of the work is application of multivariate optimization for optimization of effective parameters in the voltammetric peak current of the analytes. Under the optimized conditions, a peak separation of CF and FA is higher than 270 mV. CPE in the presence of DPC shows wide linear responses for CF and FA in the concentration ranges of 0.1-100.0 µM and 0.05-10.0 µM with detection limits of 24.0 nM and 7.5 nM (3σ), respectively. CPE in the presence of DPC exhibits good repeatability and stability for the two analytes. At the last, CPE in the presence of DPC was successfully applied to the simultaneous detection of FA and CF in urine real samples.

    更新日期:2020-01-17
  • A modified sensitive carbon paste electrode for 5-fluorouracil based using a composite of praseodymium erbium tungstate
    Microchem. J. (IF 3.206) Pub Date : 2020-01-16
    Mehdi Rahimi-Nasrabadi; Farhad Ahmadi; Hana Beigizadeh; Meisam Sadeghpour Karimi; Ali Sobhani-Nasab; Yvonne Joseph; Hermann Ehrlich; Mohammad Reza Ganjali

    This paper describes the modification of a modified carbon paste electrode (CPE) using nanoparticles of praseodymium erbium tungstate (Pr:Er). The modified electrode was used for the sensitive voltammetric detection of an anticancer drug (5-fluorouracil (5-FU)) using. The modified-CPE was evaluated using cyclic voltammetry (CV), square wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS) and the resulting data showed the irreversible 5-fluorouracil oxidation peak around 1.0 V vs. Ag/AgCl. Some key parameters such as pH, the amount of the modifier, potential amplitude, step potential and frequency were studied and optimized. The square wave voltammetry (SWV) analytical calibration curve was linear in the range of 0.01-50 μM, with a detection limit of 0.98 nM analyses. The electron transfer coefficient (α) was also determined to be 0.76. The analyte concentration was also determined in pharmaceutical formulations and recovery percentages were found to be in the range of 96–102%. The sensor had good reproducibility and repeatability with acceptable RSD values of 3.6%, and 1.02% and a rather long-term stability of around one month. The as-synthesized nanoparticles were also characterized using FESEM, TEM, FTIR and XRD techniques.

    更新日期:2020-01-17
  • Electrochemical Properties of Gold Nanosheets: Investigation of the Effect of Nanosheet Thickness Using Chemometric Methods
    Microchem. J. (IF 3.206) Pub Date : 2020-01-16
    S. Ahmadpour; M. Ajamian; J. Tashkhourian; A. Safavi; B. Hemmateenejad

    Gold nanostructures have been widely studied because of their unique size and shape dependent properties. Two-dimensional (2D) Au nanosheets (AuNSs) attract much attention for their unique features and potential applications. One parameter that should be considered in their potential applications, is their thicknesses. In this study AuNSs were synthesized in three thicknesses (25 nm, 45 nm, and 65 nm), and their electrochemical properties at a glassy carbon electrode were compared. Multivariate curve resolution-alternating least squares (MCR-ALS) was used to resolve the total current to its three main constitutes, which are faradaic, step charging and induced charging currents. The extent of contribution of each current was calculated and related to the parameters affecting the electrochemical systems such as the nature of supporting electrolyte or the composition of the electrode. The results showed that the thickness of AuNSs has a significant effect on the extent of contribution of all currents. For example, the contribution of the faradaic current is higher for 25 nm thickness of AuNSs whereas the contribution of the charging current changes reversely. Our results confirmed that thinner AuNSs are more suitable for using in construction of electrochemical sensors.

    更新日期:2020-01-17
  • Potential climatic influence on maximum stand carrying capacity for 15 Mediterranean coniferous and broadleaf species
    Forest Ecol. Manag. (IF 3.126) Pub Date : 2020-01-16
    Diego Rodríguez de Prado; Roberto San Martín; Felipe Bravo; Celia Herrero de Aza

    Climate change projections for the Mediterranean basin predict a continuous increase in extreme drought and heat episodes, which will affect forest dynamics, structure and composition. Understanding how climate influences the maximum size-density relationship (MSDR) is therefore critical to designing adaptive silvicultural guidelines based on the potential stand carrying capacity of tree species. With this aim, data from the Third Spanish National Forest Inventory (3NFI) and WorldClim databases were used to analyze climate-related variations of the maximum stand carrying capacity for 15 species from the Pinus, Fagus and Quercus genera. First, basic MSDR were fitted using linear quantile regression and observed size-density data from monospecific 3NFI plots. Reference values for maximum stocking, expressed in terms of the Maximum Stand Density Index (SDImax), were estimated by species. Then, climate-dependent MSDR models including 35 annual and seasonal climatic variables were fitted. The best climate-dependent models, based on the Akaike Information Criteria (AIC) index, were used to determine the climatic drivers affecting MSDR, to analyze general and species-specific patterns and to quantify the impact of climate on maximum stand carrying capacity. The results showed that all the selected climate-dependent models improved the goodness of fit over the basic models. Among the climatic variables, spring and summer maximum temperatures were found to be key drivers affecting MSDR for the species studied. A common trend was also found across species, linking warmer and drier conditions to smaller SDImax values. Based on projected climate scenarios, this suggests potential reductions in maximum stocking for these species. In this study, a new index was proposed, the Q index, for evaluating the impact of climate on maximum stand carrying capacity. Our findings highlight the importance of using specific climatic variables to better characterize how they affect MSDR. The models presented in this study will allow us to better explain interactions between climate and MSDR while also providing more precise estimates concerning maximum stocking for different Mediterranean coniferous and broadleaf tree species.

    更新日期:2020-01-17
  • Effects of simulated sea level rise on stocks and sources of soil organic carbon in Kandelia obovata mangrove forests
    Forest Ecol. Manag. (IF 3.126) Pub Date : 2020-01-16
    Jiahui Chen; Yingying Huang; Guangcheng Chen; Yong Ye

    Changes in stocks and sources of soil organic carbon (OC) with sea level rise (SLR) are crucial to carbon processes and sequestration benefits in mangrove forests. Soil OC contents and stocks were compared among three 11 years-old Kandelia obovata mangrove forests with SLR of 0, 40 and 80 cm, respectively, simulating the current, future ~100 years’ and future ~200 years’ SLR of mangrove forests along Jiulong River Estuary, an important K. obovata area in Fujian, China. Contribution rates of mangrove plants and allochthonous suspended particulate organic matter in tidal water (SPOM) to soil OC were also estimated. Significantly higher soil OC contents and stocks were measured at site SLR 80 cm. Mean OC stocks at sites SLR 80 cm, SLR 40 cm and SLR 0 cm were 23.82, 16.68 and 17.85 kg C m−2, respectively. High soil labile organic carbon (LOC) contents were also found at site SLR 80 cm, while low profiles of soil δ13C values were measured at site SLR 40 cm. Mean contribution rates of mangrove plants to soil OC were 36.65%, 35.42% and 21.79% at sites SLR 80 cm, SLR 40 cm and SLR 0 cm, respectively, and significantly higher OC contribution rates of mangrove plants were found at site SLR 80 cm. These indicated that SLR will increase soil OC stock and mangrove contribution to soil OC.

    更新日期:2020-01-17
  • Development phase convergence across scale in a primeval European beech (Fagus sylvatica L.) forest
    Forest Ecol. Manag. (IF 3.126) Pub Date : 2020-01-17
    Eric K. Zenner; JeriLynn E. Peck; Martina L. Hobi

    Despite the recognized influence of spatial resolution on forest life cycle classification typologies, neither the effects of scale (i.e., extent) on development phase assignment nor the pathways of subplot convergence with increasing scale have been quantified. We applied an objective development phase classification protocol to subplots of a 10-ha primeval European beech (Fagus sylvatica L.) forest ranging from 156.25 m2 to 10000 m2 in extent. The assignment of one of the eight phases [Gap and Regeneration, Establishment, Early Optimum, Mid Optimum, Late Optimum, Terminal, Decay, and Multi-Sized (aka Plenter)] to each subplot was tallied at each scale and the pathways by which subplots in given phases at smaller scales were merged into larger subplots were summarized. As spatial scale increased, the most immature phases (Gap and Regeneration, Establishment, Early Optimum) converged into the mature phases (Terminal, Decay, Multi-Sized) and were no longer assigned by the 1250–2500 scale at which the mature phases dominated. As subplots assigned to one of the eight development phases at a given scale were merged with neighboring subplots to attain the next larger scale, many different possible pathways for convergence emerged but the number of observed combinations declined with increasing scale. Assignment to the most complex phase increased with increasing scale until ultimately all subplots were assigned to this phase. In addition to confirming the scale dependency of development phase assignment, these results support the hypothesis that the immature development phases are assigned predominantly at the smaller scales that correspond to the prevailing disturbance regime while mature phases are assigned predominantly at larger scales. We further observed a convergence with increasing scale on the most structurally complex phase. The convergence of immature phases on more mature phases with increasing scale likely reflects the dual dynamic of fast, short-term gap dynamics predominant at small scales and the slow, long-term dynamics of maturation, maintenance, and persistence that dominate at larger scales. The assignment of development phases at fine spatial resolutions, therefore, is necessary but not sufficient for a comprehensive investigation of the mosaic cycle. Further, examining development phase assignment across spatial scale may enable the identification of the spatial scale of predominant disturbances by investigating and comparing the rate at which phase transitions occur across scales in different primeval forests.

    更新日期:2020-01-17
  • Bedrock type drives forest carbon storage and uptake across the mid-Atlantic Appalachian Ridge and Valley, U.S.A.
    Forest Ecol. Manag. (IF 3.126) Pub Date : 2020-01-16
    Warren P. Reed; Margot W. Kaye

    Lithology influences forest carbon storage and productivity yet is often overlooked for forests of the eastern United States, a large and important carbon sink. This research explores the influence of two common lithologies of the Ridge and Valley physiographic province in the Appalachian Mountains, shales and sandstones, on live aboveground carbon storage, carbon uptake, forest community composition and their interrelationships. We couple forest inventory data from 565 plots from Pennsylvania state agencies with a suite of GIS derived landscape metrics including measures of climate, topography and soil physical properties to identify biotic and abiotic drivers of live forest carbon dynamics in relation to lithology. Forests growing on shale bedrock store more live aboveground carbon compared to forests on sandstone when controlling for stand age, which ranged from 20 to 200 years. Furthermore, forests in the dominant ages (81–120 years) store more live aboveground carbon (108.1 Mg/ha vs. 86.5 Mg/ha) and uptake live aboveground carbon at a faster rate (1.32 Mg/ha/yr vs 0.85 Mg/ha/yr) on shale compared to sandstone respectively. Overall forest communities on both lithologies are dominated by oaks (Quercus spp.), however northern red oak (Q. rubra) is more dominant at shale sites compared to chestnut oak (Q. prinus), which dominates on sandstone. Most species in the forest tend to be more productive on shale, which may account for differences in carbon pools and fluxes across the landscape. Tree species richness is higher in sites on shale bedrock, but biodiversity-productivity relationships within lithologic classifications fail to account for differences in forest productivity. Modeled live aboveground carbon storage points to topography (elevation and aspect) and soil physical properties (% clay and available water capacity) as important influences on forest productivity that related back to lithology. Incorporating lithology into forest management strategies that are focused on a variety of ecosystem services can aid future site selection, and we demonstrate that forests on shale bedrock grow faster, store more carbon and have higher species diversity. The results presented here highlight the potential for underlying bedrock to exert differential influences on forest ecosystem structure and function across a region.

    更新日期:2020-01-17
  • Species-specific effects of the herbaceous layer on recruitment of woody species under different shading and precipitation conditions
    Forest Ecol. Manag. (IF 3.126) Pub Date : 2020-01-17
    Nicolás Velasco; Pablo I. Becerra

    Herbs may affect the recruitment of woody species. However, most studies have evaluated the impact of one particular herb species or the herbaceous layer as a whole. It is less known if different herb species have different effects on recruitment of woody species, and whether these effects depend on environmental conditions. In this paper, we evaluated the effects of different native and exotic herb species on recruitment of nine woody species in central Chile, under different conditions of shading and precipitation. The experiment was carried out in an open ruderal area in Santiago, Chile. We conducted a factorial experiment with 360 1 × 1 m pots with monospecific crops of eight herb species and a control without herbs, two levels of irrigation (245 and 534 mm) simulating two precipitation regimes, and the presence or absence of artificial shade simulating a woody canopy. Nine woody species common to the region were sown in each pot. Luminosity (PAR), soil moisture, herb volume, richness of woody species and seedling density of woody species recruited were measured. The effects of herb species on woody species richness varied from neutral in the open condition to mainly negative in the shaded condition. Differences in irrigation did not modify the effects of herbs on species richness. The effects of herb species were more variable when woody species were considered individually. Negative and neutral effects predominated, although some positive effects were observed under shaded and wetter conditions. Our results suggest that different herb species have distinct effects on recruitment of specific woody species and species richness, which mainly depend on shade conditions and secondarily on the precipitation regime, and that herb-woody species interactions are highly specific. Thus, management focused in herb controlling should be species-specific, in terms of herb and woody species, and dependent on climate and woody cover.

    更新日期:2020-01-17
  • Initial establishment of commercial tree species under enrichment planting in a Central Amazon secondary forest: Effects of silvicultural treatments
    Forest Ecol. Manag. (IF 3.126) Pub Date : 2020-01-17
    Victor Alexandre Hardt Ferreira dos Santos; Marciel José Ferreira

    Enrichment planting has the potential to conserve wide areas of secondary forest in the Amazon. Therefore, it is necessary to understand the effects of silvicultural treatments applied to secondary forest management on the initial establishment of planted species. Enrichment planting was performed in a Central Amazon secondary forest to test whether the growth, mortality and presence of shoot borer attacks of six commercial trees species – in the first two years after planting – depend on canopy trees refinement and understory slashing. Six commercial tree species were planted under a gradient of light transmittance that was created by canopy trees refinement applied in six levels of basal area reduction (0; 20; 40; 60; 80 and 100%) and combined with two understory slashing levels (control and understory slashed). The effects of silvicultural treatments on root collar diameter and height growth (realized and relative), mortality and shoot borer attack were evaluated during the first and second year after planting. The relationships between realized growth and light transmittance were different among the species, but maximum growth was observed at high light transmittance for all species. Understory slashing slightly increased the response of realized growth to light transmittance. Species relative growth was strongly affected by light transmittance, but there was a reduced response in the second year after planting, particularly in the light-demanding pioneer species (Cedrela fissilis, Tabebuia rosea and Swietenia macrophylla). Pioneer species mortality was higher in deep shade (lowest transmittance) and was related to fast growth at full sun (highest transmittance) during the first, but not the second, year after planting. Shade-tolerant species (Hymenaea courbaril, Carapa guianensis and Bertholletia excelsa) have slower growth in full sun than pioneers, but only during the first year. Shoot borer attacks in Meliaceae species (C. fissilis, S. macrophylla and C. guianensis) occurred more frequently in high light transmittance and understory slashed environments but were absent in intermediary to low light transmittance and untreated understory. Thus, silvicultural treatments improve the initial establishment of commercial tree species in secondary forest enrichment planting sites. However, such findings should be analyzed considering the effects on growth, mortality and pest attacks during the seedling to juvenile tree development stages after planting.

    更新日期:2020-01-17
  • Becoming sexy: Contrapposto pose increases attractiveness ratings and modulates observers’ brain activity
    Biol. Psychol. (IF 2.627) Pub Date : 2020-01-17
    Farid Pazhoohi; Joana Arantes; Alan Kingstone; Diego Pinal

    Previous neurophysiological studies have revealed the neural correlates of human body form perception, as well as those related to the perception of attractive body sizes. In the current study we aimed to extend the neurophysiological studies regarding body perception by investigating the perception of human body posture to provide insights into the cognitive mechanisms responsive to bodily form, and the processing of its attractiveness. To achieve these aims, we used the contrapposto posture which creates an exaggeration of low waist to hip ratio (WHR), an indicator of women's attractiveness. Electroencephalogram (EEG) signals were recorded while participants completed both (i) an oddball task presenting female body forms differing in pose (contrapposto vs. standing) and viewing angle (anterior vs. posterior), and (ii) a subsequent active attractiveness judgement task. Behavioral results showed that a contrapposto pose is considered more attractive than a neutral standing pose. Result at the neural level showed that body posture modulates the visual information processing in early ERP components, indicating attentional variations depending on human body posture; as well as in late components, indicating further differences in attention and attractiveness judgement of stimuli varying in body pose. Furthermore, the LORETA results identified the middle temporal gyrus as well as angular gyrus as the key brain regions activated in association with the perception and attractiveness judgment of females’ bodies with different body poses. Overall, the current paper suggests the evolutionary adaptive preference for lower WHRs as in the contrapposto pose activating brain regions associated with visual perception and attractiveness judgement.

    更新日期:2020-01-17
  • Sex Differences in Emotional Concordance
    Biol. Psychol. (IF 2.627) Pub Date : 2020-01-17
    Julina A. Rattel; Iris B. Mauss; Michael Liedlgruber; Frank. H. Wilhelm

    Emotions involve response synchronization across experiential, physiological, and behavioral systems, referred to as concordance or coherence. Women are thought to be more emotionally aware and expressive than men and may therefore display stronger response concordance; however, research on this topic is scant. Using a random-order film-average design, we assessed concordance among experiential (arousal, valence), autonomic (electrodermal activity, heart rate, preejection-period, respiratory-sinus-arrhythmia), respiratory (respiratory-rate), and behavioral (corrugator and zygomatic electromyography) responses to 15 two-minute films varying in valence and arousal. We then calculated for each participant and pair of measures a within-subject correlation index using averages from the 15 films. Pronounced individual concordance of up to 0.9 was observed. Arousal-physiology and valence-behavior concordances were particularly pronounced. Women displayed higher concordance than men for almost all measures. Findings indicate stronger psychophysiological response coupling in women than men and provide novel insights into affective differences between the sexes.

    更新日期:2020-01-17
  • Sympathetic Contributions to Habituation and Recovery of the Cardiac Defense Response
    Biol. Psychol. (IF 2.627) Pub Date : 2020-01-17
    Alba Garrido; Stefan Duschek; Javier Rodríguez Árbol; Isis González Usera; Jaime Vila; José Luis Mata

    The cardiac defense response (CDR) to intense auditory stimulation is characterized by two acceleration-deceleration heart rate (HR) components. This study investigated contributions of sympathetic cardiac control to habituation and recovery of the CDR. Fifty-six healthy subjects were presented with noise stimuli eliciting the CDR. Three stimuli were presented with short and long (2.5 min and 12.5 min) inter-trial intervals (ITIs). The pre-ejection period was recorded as an index of sympathetic cardiac control, in addition to HR. Repeated stimulation at short ITI was associated with marked habituation of the HR and sympathetic responses; both responses exhibited a degree of recovery with long ITI. Regarding the time course, the first acceleration-deceleration was accompanied by a decline and subsequent increase in sympathetic cardiac control. During the second acceleration-deceleration, the parameters exhibited parallel courses. These results suggest that the sympathetic contribution to the habituation and recovery is limited to the second HR component.

    更新日期:2020-01-17
  • The novel Huntiella omanensis mating gene, MAT1-2-7, is essential for ascomatal maturation
    Fungal Genet. Biol. (IF 3.314) Pub Date : 2020-01-17
    Andi M. Wilson; P. Markus Wilken; Magriet A. van der Nest; Michael J. Wingfield; Brenda D. Wingfield

    Sexual reproduction is a highly conserved feature of the eukaryotes, yet sexual compatibility is determined by a wide variety of mechanisms. In ascomycete fungi, sexual development is controlled by genes at the mating type (MAT) locus that confer either MAT1-1 or MAT1-2 mating identity. Although the locus harbours, at minimum, a single gene, the individual MAT loci of certain species, including Huntiella omanensis, encode for two or more genes. The MAT1-2 idiomorph of H. omanensis is made up of MAT1-2-1, a primary MAT gene that is highly conserved in the Pezizomycotina and possesses a well-characterized DNA binding motif, the HMG-box domain. The idiomorph also harbours a novel secondary MAT gene, named MAT1-2-7, with no recognizable functional domains. In this study, we developed a transformation and CRISPR-Cas9-based genome editing protocol to characterize the MAT1-2-7 gene with respect to its function in mating. We have shown that MAT1-2-7 is essential for sexual reproduction and that isolates carrying the truncated MAT1-2-7 gene are incapable of ascomatal maturation and further sexual development. MAT1-2-7 was also shown to influence the vegetative radial growth rate of H. omanensis, illustrating the pleiotropic effects often associated with MAT genes.

    更新日期:2020-01-17
  • Increased activity of the sterol branch of the mevalonate pathway elevates glycosylation of secretory proteins and improves antifungal properties of Trichoderma atroviride
    Fungal Genet. Biol. (IF 3.314) Pub Date : 2020-01-17
    Sebastian Graczyk; Urszula Perlińska-Lenart; Wioletta Górka-Nieć; Renata Lichota; Sebastian Piłsyk; Patrycja Zembek; Jacek Lenart; Przemysław Bernat; Elżbieta Gryz; Justyna Augustyniak; Grażyna Palamarczyk; Joanna S. Kruszewska

    Some Trichoderma spp. have an ability to inhibit proliferation of fungal plant pathogens in the soil. Numerous compounds with a proven antifungal activity are synthesized via the terpene pathway. Here, we stimulated the activity of the mevalonate pathway in T. atroviride P1 by expressing the Saccharomyces cerevisiae ERG20 gene coding for farnesyl pyrophosphate (FPP) synthase, a key enzyme of this pathway. ERG20-expressing Trichoderma strains showed higher activities of FPP synthase and squalene synthase, the principal recipient of FPP in the mevalonate pathway. We also observed activation of dolichyl phosphate mannose (DPM) synthase, an enzyme in protein glycosylation, and significantly increased O- and N-glycosylation of secreted proteins. The hyper-glycosylation of secretory hydrolases could explain their increased activity observed in the ERG20 transformants. Analysis of the antifungal properties of the new strains revealed that the hydrolases secreted by the transformants inhibited growth of a plant pathogen, Pythium ultimum more efficiently compared to the control strain. Consequently, the biocontrol activity of the transgenic strains, determined as their ability to protect bean seeds and seedlings against harmful action of P. ultimum, was also improved substantially.

    更新日期:2020-01-17
  • The toxin goniodomin, produced by Alexandrium spp., is identical to goniodomin A
    Harmful Algae (IF 5.012) Pub Date : 2020-01-16
    Constance M. Harris; Kimberly S. Reece; Donald F. Stec; Gail P. Scott; William M. Jones; Patrice L.M. Hobbs; Thomas M. Harris
    更新日期:2020-01-17
  • Do protected areas hamper economic development of the Amazon region? An analysis of the relationship between protected areas and the economic growth of Brazilian Amazon municipalities
    Land Use Policy (IF 3.573) Pub Date : 2020-01-16
    Érico Emed Kauano; José Maria Cardoso Silva; José Alexandre Felizola Diniz Filho; Fernanda Michalski

    The Brazilian Amazon harbours 70 % of the world’s tropical forests and is essential to the country’s economy because it maintains biodiversity, sustains the livelihoods of the indigenous people and local communities, and provides ecosystem services such as water production, soil stabilization, flood prevention, and climate regulation. In the last three decades, the Brazilian government has established a regional protected area (PA) network that currently covers approximately 48 % of the region. Despite their importance, some sectors of the Brazilian society have argued that the expansion of the PAs across the region hampers the local economic development, because they make less area available for non-forest economic activities such as large-scale agriculture, mining, and power generation. In this study, we analysed the relationship between local economic growth and PA coverage in 516 municipalities in the Brazilian Amazon from 2004 to 2014. We modelled the impact of the coverage of the three types of PAs (strictly-protected, multiple-use, and indigenous lands) on the (i) compound annual growth rate (CAGR) of the real gross domestic product per capita (GDP per capita), and (ii) real gross value added per capita (GVA per capita) of the agriculture, industry, services, and government sectors in each municipality. The models also considered the following control variables at the municipal level: area, age, per capita GPD in 2004 (or per capita GVAs in 2004), population growth rate between 2004 and 2014, education index, deforested area outside PA per capita, deforested area inside PA per capita, degraded area outside PA per capita, degraded area inside PA per capita, and presence of illegal mining within PA. We applied spatial Durbin error models (SDEM) to analyse the direct, indirect, and total impacts of the PAs on the local economic growth. We did not find a statistically significant relationship between the local economic growth and PA coverage in any of the three PA groups evaluated. Only the total impact of the GVA per capita of the industry was negatively correlated with the coverage of the strictly-protected PAs. Our findings do not support the arguments used by some interest groups of the Brazilian society that the social and environmental gains generated through the expansion of PAs across the region constrain the overall local economic growth.

    更新日期:2020-01-17
  • An indicator to reflect the mitigating effect of Common Agricultural Policy on soil erosion
    Land Use Policy (IF 3.573) Pub Date : 2020-01-16
    Pasquale Borrelli; Panos Panagos

    This study presents the updated version of the recently published LANDUM model [Land Use Policy 48, 38–50 (2015)]. LANDUM is integrated into the 100 m resolution RUSLE-based pan-European soil erosion risk modelling platform of the European Commission. It estimates the effects of local land use and management practices on the magnitude of soil erosion across each NUTS2 region of the European Union. This is done based on a spatially explicit estimation of the so-called cover-management factor of (R)USLE family models which is also known as C-factor. In this updated version, the data on soil conservation measures (i.e., reduced tillage, cover crops and plant residues) reported in the latest EU Farm Structure Survey (2016) were integrated and elaborated in LANDUM in order to estimate the changes of the C-factor in Europe between 2010 and 2016. For 2016, a C-factor of 0.2316 for the arable land of the 28 Member States of the European Union was estimated. This implies an overall decrease of C-factor of ca. -0.84 % compared to the 2010 survey. The change in C-factor from 2010 to 2016 could be an indication for the effectiveness of Common Agricultural Policy (CAP) soil conservation measures in reducing soil erosion in Europe, especially key CAP policies such as Good Agricultural and Environmental Conditions and Greening.

    更新日期:2020-01-17
  • Farmland transition in China and its policy implications
    Land Use Policy (IF 3.573) Pub Date : 2020-01-17
    Li Ma; Hualou Long; Shuangshuang Tu; Yingnan Zhang; Yuhan Zheng

    China’s land use structure is closely related to its economic development. Based on the theoretical analysis framework of China’s farmland transition (FT), this paper establishes an evaluation index system for quantifying FT from two dimensions, the dominant transition and recessive transition, and uses K-means clustering to quantitatively divide the phases of FT in China over the past four decades. The results show that the FT in China has experienced several phases from slow transition, rapid transition, to steady transition and innovation transition, and demonstrates clear regional differences. The dominant transition phase, social and ecological farmland transition, mainly occurred during 2000–2010. The economic farmland transition occurred earlier, during 1990–2000. Spatially, the economic farmland transition gradually shifted from the southeast coastal area to the inland. The “structure-function” transition of China’s farmland in the past four decades can be divided into four phases: the preliminary exploration and development phase, the steady development and expansion phase, the market-oriented reform and deepening phase, and the reform and innovation phase. Finally, relevant policy implications and suggestions were proposed for the optimal management and regulation of farmland according to the characteristics of FT, its challenges and people’s new demand for farmland functions.

    更新日期:2020-01-17
  • Cell senescence and fibrotic lung diseases
    Exp. Gerontol. (IF 3.080) Pub Date : 2020-01-17
    Rui-Ming Liu; Gang Liu

    Idiopathic pulmonary fibrosis (IPF) is a progressive fatal lung disorder with an unknown etiology and very limited therapeutic options. The incidence and severity of IPF increase with advanced age, suggesting that aging is a major risk factor for IPF. The mechanism underlying the aging-related susceptibility to IPF, however, remains unclear. Cellular senescence, a permanent arrest of cell growth, has been increasingly recognized as an important contributor to aging and aging-related diseases, including IPF. Senescent cells have been identified in IPF lungs and in experimental lung fibrosis models. Removal of senescent cells pharmacologically or genetically improves lung function and reverses pulmonary fibrosis induced by different stimuli in experimental fibrosis models. Treatment with senolytic drugs also improves clinical symptoms in IPF patients. These intriguing findings suggest that cellular senescence contributes importantly to the pathogenesis of fibrotic lung diseases and targeting senescent cells may represent a novel approach for the treatment of fibrotic lung disorders. In this mini review, we summarize the recent advance in the field regarding the role of cellular senescence in fibrotic lung diseases, with a focus on IPF.

    更新日期:2020-01-17
  • Optimal lighting levels for stair safety: Influence of lightbulb type and brightness on confidence, dynamic balance and stepping characteristics
    Exp. Gerontol. (IF 3.080) Pub Date : 2020-01-17
    Neil M. Thomas; Timmion Skervin; Richard J. Foster; Thomas D. O'Brien; Mark G. Carpenter; Constantinos N. Maganaris; Vasilious Baltzopoulos; Carolyn Lees; Mark A. Hollands

    Introduction Poor lighting has been associated with stair falls in young and older adults. However, current guidelines for illuminating stairs seem arbitrary, differ widely between sources, and are often difficult to interpret. Aims Here we examined the influence of real-world bulb illumination properties on stair descent safety in young and older adults, with a view to generating preliminary evidence for appropriate lightbulb use/stair illumination. Methods Stair tread illumination (lux) was measured in a standard UK home (2.23 m ceiling) from a low (50 W; 630 lm) and a high (103 W, 1450 lm) power compact fluorescent lamp (CFL) bulb from the time they were turned on until they reached full brightness. This enabled modelling of their illumination characteristics during warm up. Illumination was also measured from a low (40 W, 470 lm) and a high (100 W, 1521 lm) power LED bulb at first turn-on. Computer-controlled custom lighting then replicated these profiles, in addition to a Bright control (350 lx), on an instrumented staircase descended (3 × trials per light condition) by 12 young (25.3 ± 4.4 years; 5 males), 12 higher ability older (HAOA: 69.6 ± 4.7 years; 5 males) and 13 lower ability older (LAOA: 72.4 ± 4.2; 3 males) healthy adults. Older adults were allocated to ability groups based on physiological and cognitive function. Stair specific confidence was assessed prior to the first descent in each new lighting condition, and whole-body 3D kinematics (Vicon) quantified margins of stability and foot clearances with respect to the step edges. Mixed ANOVAs examined these measures for within-subject effects of lighting (×5), between-subject effects of age (×3) and interactions between lighting and age. Results Use of CFL bulbs led to lower self-reported confidence in older adults (20.37%, p = .01), and increased margins of stability (12.47%, p = .015) and foot clearances with respect to the step edges (10.36%, p = .003). Importantly, using CFL bulbs increased foot clearance variability with respect to the bottom step (32.74%, p = .046), which is where a high proportion of falls occur. Conclusion Stair tread illumination from CFL bulbs at first turn on leads to less safe stair negotiation. We suggest high powered LED bulbs may offer a safer alternative.

    更新日期:2020-01-17
  • Long-term bio-power of ceramic Microbial Fuel Cells in individual and stacked configurations
    Bioelectrochemistry (IF 4.474) Pub Date : 2020-01-17
    Iwona Gajda; Oluwatosin Obata; Maria Jose Salar-Garcia; John Greenman; Ioannis A. Ieropoulos
    更新日期:2020-01-17
  • Zinc oxide-gold nanocomposite as a proper platform for label-free DNA biosensor
    Bioelectrochemistry (IF 4.474) Pub Date : 2020-01-16
    Zahra Hatami; Elham Ragheb; Fahimeh Jalali; Mahmoud Amouzadeh Tabrizi; Mojtaba Shamsipur

    In this study, a simple and cost-effective electrochemical DNA biosensor was developed for sensitive detection of mycobacterium tuberculosis (TB). Nanocomposite of zinc oxide (ZnO) and gold nanoparticles (AuNPs) was used as a platform for immobilizing thiolated TB DNA (probe DNA). ZnO was electrodeposited on a glassy carbon electrode by potentiostat electrolysis of Zn (NO3)2 solution at -1.0 V (vs. Ag/AgCl), then AuNPs were loaded as the second layer at -0.4 V from HAuCl4 solution. Thiolated probe DNA was then covalently attached to AuNPs. Anodic peak current of Fe (CN)6 3-/4- was followed in hybridization experiments and a linear calibration curve was obtained in concentration range of 2.5–250 pM and limit of detection (LOD) of 1.8 pM for target DNA. The label-free TB biosensor exhibited high selectivity, suitable stability, and reproducibility.

    更新日期:2020-01-17
  • Impacts of moisture sources on the temporal and spatial heterogeneity of monsoon precipitation isotopic altitude effects
    J. Hydrol. (IF 4.405) Pub Date : 2020-01-16
    Yuanmei Jiao; Chengjing Liu; Zhilin Liu; Yinping Ding; Qiue Xu

    Moisture sources affect the temporal variations of the elevation effects on the stable isotopes in monsoon precipitation. However, whether it will lead to spatial variations and form a specific spatial–temporal heterogeneity pattern remains to be explored. Based on the monthly precipitation samples collected in Ailao Mountains of East Asian monsoon region, we computed and identified five moisture source regions to facilitate its comparison to the monthly oxygen isotope composition (δ18O) of precipitation with HYSPLIT model. We analysed the influence mechanisms of the moisture sources on the temporal and spatial heterogeneity of the elevation effect on the hydrogen and oxygen stable isotopes during dry and rainy seasons. We found that the temporal heterogeneity of the elevation effects on the precipitation 18O depends on the proportion of the moisture sources in the dominant direction, and as the proportion increases, the elevation effect becomes more significant. The spatial heterogeneity depends on the combination complexity of the moisture sources, the simpler the combinations, the more significant the elevation effects. The results demonstrate that for precipitation δ18O in Ailao Mountains, the dominant of monsoon moisture sources (the ratio higher than 50%) can result in significant elevation effects, while the mixtures of multiple moisture sources and the dominant of local moisture sources will lead to no elevation effects. Future studies should pay more attention to the influence mechanism of the spatial and temporal heterogeneity of the elevation effects on a relatively larger or global scale.

    更新日期:2020-01-17
  • Generation of an induced pluripotent stem cell line (SDQLCHi009-A) from a patient with 47,XXY and Ornithine Transcarbamylase Deficiency carrying a hemizygote mutation in OTC
    Stem Cell Res. (IF 3.929) Pub Date : 2020-01-17
    Xiaomeng Yang; Beibei Yan; Haiyan Zhang; Yanyan Ma; Qi Zhou; Yue Li; Jingyun Guan; Dong Wang; Yi Liu; Zhongtao Gai

    An induced pluripotent stem cell (iPSC) line was generated from peripheral blood mononuclear cells of a 3-day-old boy with 47,XXY and Ornithine Transcarbamylase Deficiency carrying hemizygote mutation (c.663+2T>G (sliping)) in OTC. The iPSCs had original 47,XXY, and mutation in OTC, expressing pluripotency markers and bearing differentiation potential in vitro.

    更新日期:2020-01-17
  • Generation of a Human iPSC line (SDQLCHi021-A) from a patient with methylmalonic acidemia cblC type carrying compound heterozygous mutations in MMACHC gene
    Stem Cell Res. (IF 3.929) Pub Date : 2020-01-16
    Jingyun Guan; Zilong Li; Haiyan Zhang; Xiaomeng Yang; Yanyan Ma; Yue Li; Rui Dong; Zhongtao Gai; Yi Liu

    Methylmalonic acidemia and homocystinuria, cblC type is a rare autosomal recessive inheritance disease. Its clinical phenotype involves multiple systems with varying degrees of severity. The disease is caused by the mutations in the MMACHC gene located on chromosome 1p34.1. Here we report the generation of an iPSC line from the PBMCs of a patient with compound heterozygous mutations in the MMACHC gene. This new iPSC line will allow a better understanding of the MMA disease.

    更新日期:2020-01-17
  • A 2-D imaging-assisted geometrical transformation method for non-destructive evaluation of the volume and surface area of avian eggs
    Food Control (IF 4.248) Pub Date : 2020-01-17
    Valeriy G. Narushin; Gang Lu; James Cugley; Michael N. Romanov; Darren K. Griffin

    Egg volume and surface area are reliable predictors of quality traits for both table and hatching chicken eggs. A new non-destructive technique for the fast and accurate evaluation of these two egg variables is addressed in the present study. The proposed method is based on the geometrical transformation of actual egg contour into a well-known geometrical figure which shape most of all resembles the examined egg. The volume and surface area of an examined egg were recomputed using the formulae appropriate for three figures including sphere, ellipsoid, and egg-shape ovoid. The method of the geometrical transformation includes the measurements of the egg length and the area of the examined eggs. These variables were determined using two-dimensional (2-D) digital imaging and image processing techniques. The geometrical transformation approach is proven to be reliable to turn the studied chicken eggs into the three chosen ovoid models, with the best prediction being shown for the ellipsoid and egg-shape ovoid, whilst the former was slightly more preferable. Depending on the avian species studied, we hypothesise that it would be more suitable to use the sphere model for more round shaped eggs and the egg-shaped ovoid model if the examined eggs are more conical. The choice of the proposed transformation technique would be applicable not only for the needs of poultry industry but also in ornithological, basically zoological studies when handling the varieties of eggs of different shapes. The experimental results show that the method proposed is accurate, reliable, robust and fast when coupled and assisted with the digital imaging and image processing techniques, and can serve as a basis for developing an appropriate instrumental technology and bringing it into the practice of poultry enterprises and hatcheries.

    更新日期:2020-01-17
  • Dietary exposure and health risk characterization of aflatoxin B1, ochratoxin A, fumonisin B1, and zearalenone in food from different provinces in Northern Vietnam
    Food Control (IF 4.248) Pub Date : 2020-01-17
    Tuan Huu Do; Son Cao Tran; Chi Dinh Le; Binh Thi Ha Nguyen; Thao Thi Phuong Le; Hao Thi Hong Le; Tuyen Danh Le; Thu Hung Thai-Nguyen

    A dietary exposure and health risk assessment of mycotoxins including aflatoxin B1, fumonisin B1, ochratoxin A, and zearalenone was conducted in 3 provinces in Northern Vietnam namely Hanoi, Thanh Hoa, and Ha Giang. Results of the analysis of samples of maize, rice, peanut, and sesame revealed the presence of these mycotoxins in all samples and sampling locations. Aflatoxin B1 was the most frequently detected (19.1%) and widely distributed among different types of samples, whereas the percentage occurrence of fumonisin B1, ochratoxin A, and zearalenone were 11.2, 5.9 and 6.3, respectively. The later three mycotoxins were detected mostly in maize. The exposure to aflatoxin B1 at detected levels could lead to 0.23, 0.65 and 21.0 cases of liver cancer per 100,000 adult people per year in Hanoi, Thanh Hoa and Ha Giang, respectively. The risk assessment also showed the unsafe exposure to ochratoxin A and fumonisin B1 in the highland region where the people consume a large amount of foods derived from maize. In Ha Giang, the mean exposures to fumonisin B1 were lower than its PMTDI (Provisional Maximum Tolerable Daily Intake), however, the 95th percentile values were 1.1–1.9 times of the PMTDI. The mean exposures to ochratoxin A in Ha Giang were about 2.4–3.6 times higher than its PMTWI (Provisional Maximum Tolerable Weekly Intake). There was no risk of fumonisin B1 and ochratoxin A in Hanoi and Thanh Hoa. The dietary exposure to zearalenone was within its PMTDI in all locations. The results pointed out the need for further improvement of the control of these mycotoxins in Vietnam, especially in some highland provinces.

    更新日期:2020-01-17
  • Convallatoxin Promotes Apoptosis and Inhibits Proliferation and Angiogenesis through Crosstalk between JAK2/STAT3 (T705) and mTOR/STAT3 (S727) Signaling Pathways in Colorectal Cancer
    Phytomedicine (IF 4.180) Pub Date : 2020-01-17
    Zhi Hong Zhang; Ming Yue Li; Zhe Wang; Hong Xiang Zuo; Jing Ying Wang; Yue Xing; Chenghua Jin; Guanghua Xu; Lianxun Piao; Hongxin Piao; Juan Ma; Xuejun Jin
    更新日期:2020-01-17
  • High content screening identifies licoisoflavone A as a bioactive compound of Tongmaiyangxin Pills to restrain cardiomyocyte hypertrophy via activating Sirt3
    Phytomedicine (IF 4.180) Pub Date : 2020-01-17
    Rui Guo; Ningning Liu; Hao Liu; Junhua Zhang; Han Zhang; Yingchao Wang; Mirko Baruscotti; Lu Zhao; Yi Wang
    更新日期:2020-01-17
  • Differential effects of corticotropin-releasing factor and acute stress on different forms of risk/reward decision-making
    Neurobiol. Learn. Mem. (IF 3.010) Pub Date : 2020-01-17
    Courtney A. Bryce; Alexandra J. Adalbert; Mona M. Claes; Mieke van Holstein; Stan B. Floresco

    Acute stress and corticotropin-releasing factor (CRF) have been show to perturb cost/benefit decision making involving effort costs. However, previous studies on how stress manipulations affect decisions involving reward uncertainty have yielded variable results. To provide additional insight into this issue, the current study investigated how central CRF infusion and acute restraint stress alter different forms of risk/reward decision-making guided by internal representations of risk/reward contingencies or external informative cues. Male rats were well-trained on one of two tasks that required choice between a small/certain or a large/risky reward. On a probabilistic discounting task, the probability of obtaining the larger reward increased or decreased systematically over blocks of trials (100-6.25%). On a cue-guided Blackjack task, reward probabilities (50% or 12.5%) were signaled by discriminative auditory cues. CRF (1 or 3μg) was infused intracerebroventricularly (ICV) or one-hour of restraint stress was administered prior to behavioral testing. Neither CRF nor acute stress altered risky choice on probabilistic discounting, but did increase trial omissions in the latter part of the session. Conversely on the Blackjack task, CRF reduced risky choice on good-odds trials (50%), whereas acute stress increased reward sensitivity. CRF but not acute stress also slowed decision latencies across tasks. These data reveal complex and differential manners in which increased CRF activity and acute stress alter distinct forms of risk/reward decision-making, particularly those guided by external cues.

    更新日期:2020-01-17
  • Effects of metals in wastewater on hydrogen gas production using electrohydrolysis
    Int. J. Hydrogen Energy (IF 4.084) Pub Date : 2019-03-21
    Ebru Çokay; Yasin Gürler

    Hydrogen gas was produced from metal plating wastewater by electro hydrolysis. Wastewater contains chrome, copper and nickel metals which can accelerate the production of hydrogen gas. Effects of kind of metals, the voltage and reaction time on percent hydrogen gas (HGP) were investigated. After application of different DC voltages on each metallic wastewater, percent hydrogen gas (HGP), cumulative hydrogen gas volume (CHGV), hydrogen gas formation rate (HFR) and total organic carbon (TOC) removal were also evaluated. Hydrogen gas percent was obtained as %99 at 4 V for chrome plating wastewater while percent hydrogen gas was achieved as 50% H2 gas at 4 V for copper and nickel metal plating wastewater. Maximum CHGV achieved with 4 V DC voltage for all metal plating wastewater. Maximum CHGV (4000 mL), HFR (985 mL H2 d−1) and percent hydrogen gas (99%) was observed with chrome plating wastewater at 4 V DC voltage. Hydrogen gas produced from chrome metal plating wastewater using electro hydrolysis method can be efficiently used for fuel cells as a source due to nearly pure hydrogen gas.

    更新日期:2020-01-17
  • The potential role of hydrogen as a sustainable transportation fuel to combat global warming
    Int. J. Hydrogen Energy (IF 4.084) Pub Date : 2018-11-23
    Canan Acar; Ibrahim Dincer

    Hydrogen is recognized as a key source of the sustainable energy solutions. The transportation sector is known as one of the largest fuel consumers of the global energy market. Hydrogen can become a promising fuel for sustainable transportation by providing clean, reliable, safe, convenient, customer friendly, and affordable energy. In this study, the possibility of hydrogen as the major fuel for transportation systems is investigated comprehensively based on the recent data published in the literature. Due to its several characteristic advantages, such as energy density, abundance, ease of transportation, a wide variety of production methods from clean and renewable fuels with zero or minimal emissions; hydrogen appears to be a great chemical fuel which can potentially replace fossil fuel use in internal combustion engines. In order to take advantage of hydrogen as an internal combustion engine fuel, existing engines should be redesigned to avoid abnormal combustion. Hydrogen use in internal combustion engines could enhance system efficiencies, offer higher power outputs per vehicle, and emit lower amounts of greenhouse gases. Even though hydrogen-powered fuel cells have lower emissions than internal combustion engines, they require additional space and weight and they are generally more expensive. Therefore, the scope of this study is hydrogen-fueled internal combustion engines. It is also highlighted that in order to become a truly sustainable and clean fuel, hydrogen should be produced from renewable energy and material resources with zero or minimal emissions at high efficiencies. In addition, in this study, conventional, hybrid, electric, biofuel, fuel cell, and hydrogen fueled ICE vehicles are comparatively assessed based on their CO2 and SO2 emissions, social cost of carbon, energy and exergy efficiencies, fuel consumption, fuel price, and driving range. The results show that when all of these criteria are taken into account, fuel cell vehicles have the highest average performance ranking (4.97/10), followed by hydrogen fueled ICEs (4.81/10) and biofuel vehicles (4.71/10). On the other hand, conventional vehicles have the lowest average performance ranking (1.21/10), followed by electric vehicles (4.24/10) and hybrid vehicles (4.53/10).

    更新日期:2020-01-17
  • A review on the catalysts used for hydrogen production from ammonia borane
    Int. J. Hydrogen Energy (IF 4.084) Pub Date : 2019-03-19
    Ceren Yüksel Alpaydın; Senem Karahan Gülbay; C. Ozgur Colpan

    Boron compounds have recently attracted attention in hydrogen production since they contain many hydrogen atoms. Among these compounds, ammonia borane, which has high hydrogen density (in weight basis), can be used to produce hydrogen through a hydrolysis reaction. However, since the ammonia borane solution is highly resistant to hydrolysis under ambient conditions, there is a need for active and stable catalysts to accelerate the reaction. In this review paper, unsupported and carbon-based supported metal catalysts used for hydrogen production through the hydrolysis of ammonia borane are presented. Noble metal catalysts (Ru, Rh, Pd, Pt and their binary and ternary alloys) and non-noble metal catalysts (Co, Ni, Fe, Cu and their binary and ternary alloys) were examined. The activation energy of reaction and turnover frequency (TOF) values were compared for these catalysts. Among the unsupported catalysts, it was concluded that the multi-metal catalyst systems (binary, ternary and quaternary) have higher catalytic activity than a single use of the same metals. In addition, the comparison showed that the supported catalysts are more resistant to catalytic cycles and suitable for long-term use. It was observed that CNT supported Rh (TOF = 706 mol H2 mol cat−1 min−1) and graphene supported Ru (TOF = 600 mol H2 mol cat−1 min−1) catalysts are the most active catalysts for the hydrogen generation from the ammonia borane at room temperature.

    更新日期:2020-01-17
  • Effect of fuel blend composition on hydrogen yield in co-gasification of coal and non-woody biomass
    Int. J. Hydrogen Energy (IF 4.084) Pub Date : 2019-03-15
    Busra Cabuk; Gozde Duman; Jale Yanik; Hayati Olgun

    In this study, torrefaction of sunflower seed cake and hydrogen production from torrefied sunflower seed cake via steam gasification were investigated. Torrefaction experiments were performed at 250, 300 and 350 °C for different times (10–30 min). Torrefaction at 300 °C for 30 min was selected to be optimum condition, considering the mass yield and energy densification ratio. Steam gasification of lignite, raw- and torrefied biomass, and their blends at different ratios were conducted at downdraft fixed bed reactor. For comparison, gasification experiments with pyrochar obtained at 500 °C were also performed. The maximum hydrogen yield of 100 mol/kg fuel was obtained steam gasification of pyrochar. The hydrogen yields of 84 and 75 mol/kg fuel were obtained from lignite and torrefied biomass, respectively. Remarkable synergic effect exhibited in co-gasification of lignite with raw biomass or torrefied biomass at a blending ratio of 1:1. In co-gasification, the highest hydrogen yield of 110 mol/kg fuel was obtained from torrefied biomass-lignite (1:1) blend, while a hydrogen yield from pyrochar-lignite (1:1) blend was 98 mol/kg. The overall results showed that in co-gasification of lignite with biomass, the yields of hydrogen depend on the volatiles content of raw biomass/torrefied biomass, besides alkaline earth metals (AAEMs) content.

    更新日期:2020-01-17
  • Hydrogen production via thermochemical H2O splitting using CaSO4 – CaO redox reactions
    Int. J. Hydrogen Energy (IF 4.084) Pub Date : 2019-03-27
    Rahul R. Bhosale

    By applying the principles of the second law of thermodynamics and utilizing the HSC Chemistry software, the thermodynamic equilibrium and efficiency analysis of the CaSO4CaO water splitting cycle was performed in this investigation. The temperatures desirable and the equilibrium compositions allied with the thermal reduction of CaSO4 and the re-oxidation of CaO via water splitting reaction were estimated. The obtained results indicate that the thermal reduction temperature (TH) required to completely decompose the CaSO4 was decerased from 2220 to 1890 K due to the rise in the molar flow rate of (n˙Ar) from 1 to 50 mol/s. In addition, the consequence of the TH, n˙Ar, and the water splitting temperature (TL) on the process parameters such as total amount of solar energy needed, re-radiation losses, energy dissipated by the water splitting reactor and others associated with the CaSO4CaO water splitting cycle was scrutinized. By utilizing higher n˙Ar from 1 to 50 mol/s, the TH was decreased from 2200 to 1890 K. However, as the n˙Ar was increased from 1 to 50 mol/s, the amount of heat energy needed to heat the Ar was also upsurged from 12.5 to 625.6 kW. This rise in the Q˙Ar−heating, directly reflected into an increase in the Q˙solar−cycle from 1063.4 up to 2653.9 kW. The findings of this study further confirms that the maximum solar-to-fuel energy conversion efficiency (ηsolar−to−fuel) equal to 27.4% was realized by conducting the CaSO4CaO water splitting cycle at TH = 2220 K, n˙Ar = 1 mol/s, and TL = 1100 K. By using 50% of the recuperable heat, the ηsolar−to−fuel of the CaSO4CaO water splitting cycle can be enhanced up to 36.2%.

    更新日期:2020-01-17
  • Design and analysis of a combined floating photovoltaic system for electricity and hydrogen production
    Int. J. Hydrogen Energy (IF 4.084) Pub Date : 2019-01-30
    Mert Temiz; Nader Javani

    The current study deals with a potential solution for the replacement of fossil fuel based energy resources with a sustainable solar energy resource. Electrical energy demand of a small community is investigated where a floating photovoltaic system and integrated hydrogen production unit are employed. Data are taken from Mumcular Dam located in Aegean Region of Turkey. PvSyst software is used for the simulation purposes. Furthermore, the obtained results are analyzed in the HOMER Pro Software. Photovoltaic (PV) electricity provides the required load and excess electricity to be used in the electrolyzer and to produce hydrogen. Saving lands by preventing their usage in conventional PV farms, saving the water due to reducing evaporation, and compensating the intermittent availability of solar energy are among the obtained results of the study for the considered scenario. Stored hydrogen is used to compensate the electric load through generating electricity by fuel cell. Floating PV (FPV) system decreases the water evaporation of water resources due to 3010 m2 shading area. FPV and Hydrogen Systems provides %99.43 of the electricity demand without any grid connection or fossil fuel usage, where 60.30 MWh/year of 211.94 MWh/year produced electricity is consumed by electric load at $0.6124/kWh levelized cost of electricity (LCOE).

    更新日期:2020-01-17
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  • Biohydrogen production from acid hydrolyzed wastewater treatment sludge by dark fermentation
    Int. J. Hydrogen Energy (IF 4.084) Pub Date : 2019-04-17
    Karapinar Ilgi; Balcan Onur

    Waste generation, waste management, sustainable energy production, and global warming are interrelated environmental issues to be considered together. Wastewater treatment sludge is an organic substance rich waste which causes significant environmental problems. However, these wastes can be used as raw material in biofuel generation. This study was designed to investigate the possible utilization of waste sludge in biohydrogen production by taking these facts into consideration. For this purpose, the sludge was first pre-treated with acid and then, the solid (sludge) and liquid (filtrate) phases of acid pre-treated sludge were used as the substrates for biohydrogen generation dark fermentation. Two-factor factorial experimental design method was used in acid hydrolysis of sludge to determine the effect of pH (pH = 2–6) and reaction period (time, min) elution of chemical oxygen demand (COD), total organic carbon (TOC) and total sugar (TS), NH4N and PO4P. Statistical evaluation of the results indicated that pH significantly affects the elution of organic carbon and nutrient content of sludge while the reaction time is significant for only organic carbon content. The optimum pretreatment conditions for maximum organic and nutrient elution were determined as pH = 2 and t = 1440 min. The pretreated products, named as filtrate sludge and sludge, conducted to dark fermentation under mesophilic conditions for biohydrogen generation showed that pretreatment of waste sludge at pH = 6 is the best condition giving the maximum yields (YH2) as YH2 = 24 mmol g−1 Total Sugar consumed and YH2 = 41 mmol g−1 Total sugar consumed, for filtrate and sludge, respectively.

    更新日期:2020-01-17
  • Application of aspen plus to renewable hydrogen production from glycerol by steam reforming
    Int. J. Hydrogen Energy (IF 4.084) Pub Date : 2019-03-09
    Derya Unlu; Nilufer Durmaz Hilmioglu

    Steam reforming is the most favored method for the production of hydrogen. Hydrogen is mostly manufactured by using steam reforming of natural gas. Due to the negative environmental impact and energy politics, alternative hydrogen production methods are being explored. Glycerol is one of the bio-based alternative feedstock for hydrogen production. This study is aimed to simulate hydrogen production from glycerol by using Aspen Plus. First of all, the convenient reactor type was determined. RPlug reactor exhibited the highest performance for the hydrogen production. A thermodynamic model was determined according to the formation of byproduct. The reaction temperature, water/glycerol molar feed ratio as reaction parameters and reactor pressure were investigated on the conversion of glycerol and yield of hydrogen. Optimum reaction parameters are determined as 500 °C of reaction temperature, 9:1 of water to glycerol ratio and 1 atm of pressure. Reactor design was also examined. Optimum reactor diameter and reactor length values were determined as 5 m and 50 m, respectively. Hydrogen purification was studied and 99.9% purity of H2was obtained at 25 bar and 40 °C. The obtained results were shown that Aspen Plus has been successfully applied to investigate the effects of reaction parameters and reactor sizing for hydrogen production from glycerol steam reforming.

    更新日期:2020-01-17
  • Microarray analysis of high light intensity stress on hydrogen production metabolism of Rhodobacter capsulatus
    Int. J. Hydrogen Energy (IF 4.084) Pub Date : 2019-01-22
    Muazzez Gürgan; Harun Koku; Inci Eroglu; Meral Yücel

    Biohydrogen obtained from purple non sulfur bacteria (PNSB) is an environmentally friendly alternative for hydrogen production. PNSB can be employed in large scale outdoor photobioreactors to produce hydrogen by photofermentation with sunlight as the light source. In external environmental conditions, however, bacteria can experience stress due to high light intensities, which can inhibit or slow down hydrogen production. Previous studies with other PNSB showed varying responses to light intensities (above 4000 lux), in some cases improving, and in others adversely affecting hydrogen production. In this study, Rhodobacter capsulatus, a PNSB species that produce hydrogen efficiently from dark fermenter effluents containing acetate, was used to investigate the effects of high light intensity stress on the hydrogen production metabolism at the gene expression level. A microarray analysis was carried out using a custom-design Affymetrix GeneChip TR_RCH2a520699F. R. capsulatus DSM1710 was grown under a cyclic illumination of 2000 and 7000 lux (12 h light/12 h dark) in a hydrogen production medium having 30 mM acetate and 2 mM glutamate, and was exposed to a high light intensity (10,000 lux) for 1 h in the middle of a light period. The results reveal that photosynthetic reaction center genes were down-regulated in order to protect the photosynthetic membrane from damage. On the other hand, the expression of nitrogenase and electron transport system genes were enhanced by high light intensity. These results show that a high light intensity stress drives R. capsulatus to direct gene expression towards hydrogen production, which supports the hypothesis that hydrogen production is a way for the disposal of excess reducing equivalents to maintain the internal redox balance.

    更新日期:2020-01-17
  • The effect of hydraulic retention time on thermophilic dark fermentative biohydrogen production in the continuously operated packed bed bioreactor
    Int. J. Hydrogen Energy (IF 4.084) Pub Date : 2019-01-23
    Ilgi Karapinar; Pelin Gokfiliz Yildiz; Recep Tugcan Pamuk; Firuze Karaosmanoglu Gorgec
    更新日期:2020-01-17
  • Enhanced hydrogen purification by graphene - Poly(Dimethyl siloxane) membrane
    Int. J. Hydrogen Energy (IF 4.084) Pub Date : 2019-01-29
    Filiz Ugur Nigiz; Nilufer Durmaz Hilmioglu

    In this study, a nanocomposite graphene oxide (GO) incorporated poly (dimethyl siloxane) (PDMS) membrane was produced and used for the purification of hydrogen (H2) by separating the (CO2). The produced membrane was characterized and the single-gas permeability test was performed. Effects of GO addition, trans-membrane pressure and membrane thickness on the gas separation performance of membrane were evaluated as a function of permeability and CO2/H2 selectivity. GO addition increased the CO2/H2 selectivity and H2 purification performance. The highest CO2 permeability of 3670 Barrer and CO2/H2 selectivity of 11.7 were obtained when the GO loading was 0.5 wt% when the trans-membrane pressure was 0.2 Mpa.

    更新日期:2020-01-17
  • Numerical modeling of a downdraft plasma coal gasifier with plasma reactions
    Int. J. Hydrogen Energy (IF 4.084) Pub Date : 2019-01-24
    Beycan Ibrahimoglu; M. Zeki Yilmazoglu

    In this paper, a 3D numerical simulation of a downdraft plasma gasifier with plasma reactions is conducted. The effects of the equivalence ratio (ER) on the syngas properties in the presence of the plasma reactions are investigated. The boundary conditions for the air plasma inlet of the gasifier are obtained from the outlet of a 10 kW microwave plasma generator. A conventional gasification analysis is carried out to validate the model. In the second part of the study, plasma reactions are added to conventional gasification equations. Mole fractions of the constituents of the syngas and temperature contours are obtained for different ER values. According to the results, with the increase of ER from 0.20 to 0.45 the lower heating value of the produced syngas decreased from 1536.6 kcal/m3 to 751.8 kcal/m3.

    更新日期:2020-01-17
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