当前期刊: "天文测量"类期刊
显示样式:        排序: 导出
我的关注
我的收藏
您暂时未登录!
登录
  • Effects of Crosslinker Concentration in Poly(Acrylic Acid)–KOH Gel Electrolyte on Performance of Zinc–Air Batteries
    Batteries Supercaps Pub Date : 2020-02-17
    Thuy Nguyen Thanh Tran; Michael P. Clark; Hyun–Joong Chung; Douglas Ivey

    Zinc–air batteries (ZABs) using gel polymer electrolytes suffer from low energy efficiency and poor cyclability. This issue is not only associated with the air electrode, as early failure of the battery is often due to the Zn electrode. Here, the cycle life of ZABs using alkaline poly(acrylic acid) (PAA–KOH) as the electrolyte is shown to vary by changing its crosslinking density. For ZABs using hydrogel electrolytes, understanding the failure mechanism and optimization of the hydrogel composition are key to achieving better utilization of the Zn electrode and battery rechargeability. In addition, the effects of crosslinker concentration on rheological properties, sol–gel fraction, ionic conductivity and water retention ability of the hydrogel are discussed. PAA–KOH gels with lower crosslinking concentrations are weaker, but they have higher conductivity and better water retention, whereas gels with higher crosslinking concentrations affect the diffusion of zincate ions and facilitate passivation of the Zn electrode, resulting in early failure of the battery.

    更新日期:2020-02-18
  • A signature of 33 immune‐related gene pairs predicts clinical outcome in hepatocellular carcinoma
    Cancer Med. (IF 3.357) Pub Date : 2020-02-18
    Xiao‐Yan Sun; Shi‐Zhe Yu; Hua‐Peng Zhang; Jie Li; Wen‐Zhi Guo; Shui‐Jun Zhang
    更新日期:2020-02-18
  • 更新日期:2020-02-18
  • A program of exercise, brain training, and lecture to prevent cognitive decline
    Ann. Clin. Transl. Neur. (IF 4.656) Pub Date : 2020-02-18
    Minoru Kouzuki; Toshiaki Kato; Kenji Wada‐Isoe; Shinya Takeda; Atsuhito Tamura; Yuichi Takanashi; Shintaro Azumi; Yoshinori Kojima; Chikako Maruyama; Maki Hayashi; Michimi Itou; Katsuya Urakami

    We examined the benefits of a community‐based program combining physical exercise, cognitive training, and education on dementia and lifestyle habits.

    更新日期:2020-02-18
  • GDSL esterase/lipases OsGELP34 and OsGELP110/OsGELP115 are essential for rice pollen development
    J. Integr. Plant Biol. (IF 3.824) Pub Date : 2020-02-18
    Huihui Zhang; Menglong Wang; Yiqi Li; Wei Yan; Zhenyi Chang; Haolin Ni; Zhufeng Chen; Jianxin Wu; Chunjue Xu; Xing Wang Deng; Xiaoyan Tang

    Pollen exine contains complex biopolymers of aliphatic lipids and phenolics. Abnormal development of pollen exine often leads to plant sterility. Molecular mechanisms regulating exine formation have been studied extensively but remain ambiguous. Here we report the analyses of three GDSL esterase/lipase protein genes, OsGELP34, OsGELP110, and OsGELP115, for rice exine formation. OsGELP34 was identified by cloning of a male sterile mutant gene. OsGELP34 encodes an endoplasmic reticulum protein and was mainly expressed in anthers during pollen exine formation. osgelp34 mutant displayed abnormal exine and altered expression of a number of key genes required for pollen development. OsGELP110 was previously identified as a gene differentially expressed in meiotic anthers. OsGELP110 was most homologous to OsGELP115, and the two genes showed similar gene expression patterns. Both OsGELP110 and OsGELP115 proteins were localized in peroxisomes. Individual knockout of OsGELP110 and OsGELP115 did not affect the plant fertility, but double knockout of both genes altered the exine structure and rendered the plant male sterile. OsGELP34 is distant from OsGELP110 and OsGELP115 in sequence, and osgelp34 and osgelp110/osgelp115 mutants were different in anther morphology despite both were male sterile. These results suggested that OsGELP34 and OsGELP110/OsGELP115 catalyze different compounds for pollen exine development.

    更新日期:2020-02-18
  • The transcription factor ICE1 functions in cold stress response by binding to the promoters of CBF and COR genes
    J. Integr. Plant Biol. (IF 3.824) Pub Date : 2020-02-18
    Kai Tang; Lun Zhao; Yuying Ren; Shuhua Yang; Jian‐Kang Zhu; Chunzhao Zhao

    A recent paper by Kidokoro et al. (2020) in The Plant Cell reported a transgene‐dependent transcriptional silencing phenomenon in the dominant ice1‐1 Arabidopsis mutant containing the CBF3‐LUC reporter, and questioned whether ICE1 may regulate CBF genes and may be involved in plant cold response. Here, we evaluate available evidences supporting the involvement of ICE1 in plant cold response, and provide ChIP‐seq data showing ICE1 binding to the promoters of CBF genes and other regulatory genes known to be critical for cold response as well as to the promoters of some COR genes.

    更新日期:2020-02-18
  • Effect of autologous transplant of peripheral blood mononuclear cells in combination with pro‐angiogenic factors during experimental re‐vascularization of lower limb ischemia
    J. Tissue Eng. Regen. Med. (IF 3.319) Pub Date : 2020-02-18
    Luis Padilla; Rubén Argüero‐Sánchez; Juan Miguel Rodríguez‐Trejo; Pilar Hazel Carranza‐Castro; Juan Antonio Suárez‐Cuenca; Jaime Polaco‐Castillo; Mauricio DiSilvio‐López; Javier López‐Gutiérrez; Horacio Olguín‐Juárez; Alejandro Hernández‐Patricio; Eduardo Vera‐Gómez; Alan De Jesús Gómez‐Calderón; Mario Antonio Téllez‐González; Paul Mondragón‐Terán

    Peripheral Blood Mononuclear Cells (PBMC) contains a cell fraction of Mononuclear Progenitor Cells (MPCs) which own significant angiogenic potential. Autologous transplant of PBMC and/or Platelet Rich Plasma (PRP) promotes endothelial cells differentiation in experimental lower limb ischemia, which is considered a safe and effective strategy to support revascularization, either in animal models or clinical trials. In addition, thrombin has been proposed to enrich biological scaffolds, hence increasing MPCs viability after intramuscular administration; whereas pro‐angiogenic mediators such as VEGF, TNF‐α, PAI‐1 and CXCL1 (GRO‐α) participate in the endothelial response to ischemia, through their pro‐angiogenic effects over endothelial cells proliferation, survival, migration, endothelial integrity maintenance and physiologic vascular response to injury. In the present study, we describe the effect of autologous PBMCs transplant and PRP, either with or without thrombin, over pro‐angiogenic mediators (measured by ELISA) and revascularization response (angiographic vascular pattern at 30 days after vascular occlusion) in a rat model of lower limb ischemia. The group treated with PBMC+PRP significantly induced PAI‐1, effect that was prevented by the addition of thrombin. Furthermore, treatment with PBMC+PRP+Thrombin resulted in the induction of VEGF. GRO‐α showed a sensitive induction of all pro‐angiogenic mediators. All treatments significantly stimulated revascularization, according to angiographic assessment, whereas higher effect was observed with PBMC+PRP treatment (p<0.0001). In conclusion, autologous PBMCs transplant stimulates revascularization during experimental ischemia of the lower limb; whereas particular effects over pro‐angiogenic and fibrinolytic mediators may be attributed to PBMCs and its combination of with PRP and thrombin.

    更新日期:2020-02-18
  • The protective effects of HMGA2 in the senescence process of bone marrow derived mesenchymal stromal cells
    J. Tissue Eng. Regen. Med. (IF 3.319) Pub Date : 2020-02-18
    Ziying Yang; Xuan Liu; Longgang Wang; Tao Wang; Yueqiu Chen; Xiaomei Teng; Jingjing Li; Lianbo Shao; Jie Hui; Wenxue Ye; Zhenya Shen

    Bone marrow derived mesenchymal stromal cells (MSCs) have been wildly applied to cell‐based strategies for tissue engineering and regenerative medicine, however, they have to undergo the senescence process and thus appeared to be less therapeutic effective. HMGA2, a protein belonged to high mobility group A (HMGA) family, exhibits an inversely expression level related to embryonic development and acts as a developmental regulator in stem cell self‐renewal progression. Therefore, we performed SA‐β‐gal staining, transwell assay to examine the changes of MSCs in different stages and then over‐expressed HMGA2 in MSCs by lentivirus transfection. We found the percentage of SA‐β‐gal staining positive cells in MSCs from 24‐month old SD rats (O‐MSCs) was significantly higher compared to MSCs from 2‐week old SD rats (Y‐MSCs), and the expression levels of P21 and P53, two senescence related molecules, were also significantly up‐regulated in O‐MSCs than in Y‐MSCs. In contrast, the HMGA2 expression level in O‐MSCs was dramatically down‐regulated in contrast to Y‐MSCs. In additional, the migration ability in O‐MSCs was significantly attenuated than in Y‐MSCs. After successfully over‐expressed HMGA2 in O‐MSCs, the percentage of SA‐β‐gal staining positive cells and the expression levels of P21 and P53 was reduced, and the migration ability was improved compared to O‐MSCs without treatment. Further, mRNA sequencing analysis revealed that over‐expression of HMGA2 changed the expression of genes related to cell proliferation and senescence, such as Lyz2, Pf4, Rgs2 and Mstn. Knockdown of Rgs2 in HMGA2 over‐expression O‐MSCs could antagonize the protective effect of HMGA2 in the senescence process of O‐MSCs.

    更新日期:2020-02-18
  • Platelet‐derived Transforming Growth Factor‐β1 promotes keratinocyte proliferation in cutaneous wound healing
    J. Tissue Eng. Regen. Med. (IF 3.319) Pub Date : 2020-02-18
    Deborah L.W. Chong; Sarah Trinder; Myriam Labelle; Manuel Rodriguez‐Justo; Sian Hughes; Alan M. Holmes; Chris J. Scotton; Joanna C. Porter

    Platelets are a recognised potent source of Transforming Growth Factor‐β1 (TGFβ1), a cytokine known to promote wound healing and regeneration by stimulating dermal fibroblast proliferation and extracellular matrix deposition. Platelet lysate has been advocated as a novel personalised therapeutic to treat persistent wounds, although the precise platelet‐derived growth factors responsible for these beneficial effects have not been fully elucidated. The aim of this study was to investigate the specific role of platelet‐derived TGFβ1 in cutaneous wound healing. Using a transgenic mouse with a targeted deletion of TGFβ1 in megakaryocytes and platelets (TGFβ1fl/fl.PF4‐Cre), we show for the first‐time platelet‐derived TGFβ1 contributes to epidermal and dermal thickening and cellular turnover after excisional skin wounding. In vitro studies demonstrate human dermal fibroblasts stimulated with platelet lysate containing high levels of platelet‐derived TGFβ1 did not exhibit enhanced collagen deposition or proliferation, suggesting that platelet‐derived TGFβ1 is not a key promoter of these wound healing processes. Interestingly, human keratinocytes displayed enhanced TGFβ1‐driven proliferation in response to platelet lysate, reminiscent of our in vivo findings. In summary, our novel findings define and emphasise an important role of platelet‐derived TGFβ1 in epidermal remodelling and regeneration processes during cutaneous wound healing.

    更新日期:2020-02-18
  • The Aging Metabolome‐ Biomarkers to Hub Metabolites
    Proteomics (IF 3.106) Pub Date : 2020-02-18
    Rishi Sharma; Arvind Ramanathan

    Aging biology is intimately associated with dysregulated metabolism, which is one of the hallmarks of aging. Aging related pathways such as mTOR and AMPK which are major targets of anti‐aging interventions including rapamcyin, metformin and exercise, either directly regulate or intersect with metabolic pathways. In this review we outline numerous candidate bio‐markers of aging that have emerged using metabolomics. Metabolomics studies also reveal that not all metabolites are created equally. A set of core ‘hub’ metabolites are emerging as central mediators of aging. The hub metabolites reviewed here are‐ Nicotinamide adenine dinucleotide (NAD+), reduced nicotinamide dinucleotide phosphate (NADPH), alpha ketoglutarate (aKG) and beta‐hydroxybutyrate (βHB). These ‘hub’ metabolites have signaling and epigenetic roles along with their canonical roles as co‐factors or intermediates of carbon metabolism. Together these hub metabolites suggest a central role of the TCA cycle in signaling and metabolic dysregulation associated with aging.

    更新日期:2020-02-18
  • Novel enzyme‐encapsulated DNA hydrogel for highly efficient electrochemical sensing glucose
    ChemElectroChem (IF 3.975) Pub Date : 2020-02-18
    Ruijin Zeng; Zhenliang Huang; Yankun Wang; Dianping Tang

    An innovative bioetching photoelectrochemical (PEC) mode was developed by enzyme‐encapsulated DNA hydrogel for high precision quantification of glucose, using In 2 O 3 ‐CdS nanocomposite as a photoactive matrix. In a proof‐of‐concept study, horseradish peroxidase and glucose oxidase were in‐situ encapsulated in DNA hydrogel to initiate enzymatic bioetching of CdS nanoparticles in the presence of target glucose. Since the bioetching reaction of CdS inhibits the electron transfer efficiency of In 2 O 3 and CdS, which causes a change in photocurrent intensity and thus provides a powerful bioetching PEC strategy with enzyme‐encapsulated DNA hydrogel.

    更新日期:2020-02-18
  • Highly Effective 2‐D layer Structured Titanium Carbide Electrode for Dye‐sensitized and Perovskite Solar Cells
    ChemElectroChem (IF 3.975) Pub Date : 2020-02-18
    Jingyuan Ma; Mengyao Sun; Yan-an Zhu; Huawei Zhou; Kezhong Wu; Jun Xiao; Mingxing Wu

    In this study, 2‐D layer structured Ti3C2 is synthesized using etching method under lower temperature, and then it is applied in dye‐sensitized and perovskite solar cells as counter electrode with higher activity compared with conventional TiC particles counter electrode. The dye‐sensitized solar cells fabricated using 2‐D layer structured Ti3C2 counter electrode achieves a power conversion efficiency of 9.57%, much higher than that of the counterpart device fabricated using TiC particles counter electrode (7.37%). The excellent activity of Ti3C2 electrode can be attributed to the superior charge transfer and mass transport properties owing to the specific 2‐D layer structure. Moreover, the fabricated 2‐D layer structured Ti3C2 is attempted to be applied in perovskite solar cells, thereby achieving a power conversion efficiency of 7.78% without further optimization. Thus, it exhibits a potential candidate to the noble metal electrodes.

    更新日期:2020-02-18
  • Metal‐Rich Chalcogenides for Electrocatalytic Hydrogen Evolution – Activity of Electrodes and Bulk Materials
    ChemElectroChem (IF 3.975) Pub Date : 2020-02-18
    Daniel Siegmund; Niclas Blanc; Mathias Smialkowski; Kristina Tschulik; Ulf-Peter Apfel

    Metal‐rich chalcogenides composed of high‐abundant elements recently emerged as promising catalysts for the electrocatalytic hydrogen evolution reaction. Many of these materials benefit from a high intrinsicconductivity as compared to their chalcogene‐rich congeners, greatly reducing the necessity for conductive additives or sophisticated nanostructuring. Herein, we showcast the high potential of metal‐rich transition metal chalcogenides for the electrocatalytic hydrogen formation by summarizing the recent progress achieved with M9S8 (pentlandite type) and M3S2 (heazlewoodite type) based materials, which represent the most frequently applied compositions for this purpose. By a detailed electrochemical comparison of bulk as well as pellet electrodes of metal‐rich Fe4.5Ni4.5S8 we furthermore aim at raising awareness in the community for the inherent differences of catalytic properties of materials themselves and that of fabricated electrodes thereof, a point that is often disregarded in report on HER‐catalyst systems.

    更新日期:2020-02-18
  • Mechanisms of Convective Clustering During a Two‐Day Rain Event in AMIE/DYNAMO
    J. Adv. Model. Earth Syst. (IF 3.457) Pub Date : 2020-02-18
    Wei‐Yi Cheng; Daehyun Kim; Angela Rowe; Yumin Moon; Shuguang Wang

    Physical mechanisms that are key to observed convective clustering in two‐day rain events are examined. Previous analysis of the two‐day rain events during the Atmospheric Radiation Measurement Madden‐Julian Oscillation Investigation Experiment (AMIE)/Dynamics of the Madden‐Julian Oscillation (DYNAMO) field campaign data revealed two distinct phases of convective clustering. Using a cloud‐system resolving model, we perform a series of intervention experiments to investigate the underlying mechanisms for convective clustering in each phase.

    更新日期:2020-02-18
  • Particle‐based tracking of cold pool gust fronts
    J. Adv. Model. Earth Syst. (IF 3.457) Pub Date : 2020-02-18
    Olga Henneberg; Bettina Meyer; Jan O. Haerter

    The gust fronts of convective cold pools (CPs) are increasingly recognized as loci of enhanced triggering for subsequent convective cells. It has so far been difficult to track these gust fronts in high‐resolution data, such as large‐eddy simulations (LES) — rendering current mechanistic analysis of CP interaction incomplete. Here, a simple method is defined, tested and applied, which uses horizontal advection and a condition on horizontal divergence, to emit tracers at the perimeter of surface precipitation patches. Tracers are then reliably transported to the gust front, yielding closed bands marking the CP boundary. The method thereby allows analysis of the dynamics also along the gust front, which allows to identify point‐like loci of pronounced updrafts. The tracking works well for a single idealized CP and reliably tracks a population of CPs in a mid‐latitude diurnal cycle. As the method uniquely links CPs and their tracers to a unique parent precipitation cell, it may be useful for the analysis of interactions in evolving CP populations.

    更新日期:2020-02-18
  • Machine Learning for Stochastic Parameterization: Generative Adversarial Networks in the Lorenz’96 Model
    J. Adv. Model. Earth Syst. (IF 3.457) Pub Date : 2020-02-18
    David John Gagne; Hannah M. Christensen; Aneesh C. Subramanian; Adam H. Monahan

    Stochastic parameterizations account for uncertainty in the representation of unresolved sub‐grid processes by sampling from the distribution of possible sub‐grid forcings. Some existing stochastic parameterizations utilize data‐driven approaches to characterize uncertainty, but these approaches require significant structural assumptions that can limit their scalability. Machine learning models, including neural networks, are able to represent a wide range of distributions and build optimized mappings between a large number of inputs and sub‐grid forcings. Recent research on machine learning parameterizations has focused only on deterministic parameterizations. In this study, we develop a stochastic parameterization using the generative adversarial network (GAN) machine learning framework. The GAN stochastic parameterization is trained and evaluated on output from the Lorenz ’96 model, which is a common baseline model for evaluating both parameterization and data assimilation techniques. We evaluate different ways of characterizing the input noise for the model and perform model runs with the GAN parameterization at weather and climate timescales. Some of the GAN configurations perform better than a baseline bespoke parameterization at both timescales, and the networks closely reproduce the spatio‐temporal correlations and regimes of the Lorenz’96 system. We also find that in general those models which produce skillful forecasts are also associated with the best climate simulations.

    更新日期:2020-02-18
  • Effects of topography and realistic drag on the Southern Hemisphere mid‐latitude jet in a dry model
    J. Adv. Model. Earth Syst. (IF 3.457) Pub Date : 2020-02-18
    F. Pithan; I. Polichtchouk

    Climate models have substantial biases in the climatological latitude of the Southern Hemisphere eddy‐driven jet and the timescale of annular mode variability, and disagree on the jet response to climate change. Zonally symmetric dry dynamical cores are often used for idealized modelling of the jet response to forcing and its sensitivity to model setup changes. The limits to which these models represent the key mechanisms that control the jet in complex models or the real world have not been systematically investigated. Here, we show that substantial inter‐model differences in jet latitude and strength can arise from differences in dynamical cores and resolved topography. Including topography and a more realistic surface drag in a dry model substantially alters the jet response to changes in drag strength. Using real‐world maps, enhanced drag over land shifts the jet poleward, whereas enhanced drag over the ocean leads to an equatorward shift. No universal relationship between annular mode timescale and forced response emerges in the dry model with topography. These results suggest that zonally symmetric models with Rayleigh drag lack important mechanisms that control the behaviour of the mid‐latitude jet in coupled climate models. A dry model with topography and quadratic surface drag can fill this gap in the model hierarchy.

    更新日期:2020-02-18
  • Flexible Composite Carbon Films Prepared by a Pancake‐Making Method for Electromagnetic Interference Shielding
    Adv. Mater. Interfaces (IF 4.713) Pub Date : 2020-02-18
    Minglong Yang; Qiang Wei; Jianjun Li; Yao Wang; Hongfei Guo; Liya Gao; Li Huang; Xiaodong He; Yibin Li; Ye Yuan
    更新日期:2020-02-18
  • Unique spectral signature of human cutaneous squamous cell carcinoma by photoacoustic imaging
    J. Biophotonics (IF 3.763) Pub Date : 2020-02-17
    Jenny Hult; Ulf Dahlstrand; Aboma Merdasa; Karin Wickerström; Rehan Chakari; Bertil Persson; Magnus Cinthio; Tobias Erlöv; John Albinsson; Bodil Gesslein; Rafi Sheikh; Malin Malmsjö
    更新日期:2020-02-18
  • Characterization of endogenous fluorescence in non‐small lung cancerous cells: A comparison with non‐malignant lung normal cells
    J. Biophotonics (IF 3.763) Pub Date : 2020-02-17
    Kamlesh Awasthi; Feng‐Lin Chang; Pei‐Ying Hsieh; Hsin‐Yun Hsu; Nobuhiro Ohta

    Monitoring fluorescence properties of endogenous fluorophores such as nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) in normal and cancerous cells provides substantial information noninvasively on biochemical and biophysical aspects of metabolic dysfunction of cancerous cells. Time‐resolved spectral profiles and fluorescence lifetime images of NADH and FAD were obtained in human lung non‐small carcinomas (H661 and A549) and normal lung cells (MRC‐5). Both fluorophores show the fast and slowly decaying emission components upon pulsed excitation, and fluorescence spectra of NADH and FAD show blue‐ and red‐shifts, respectively, during their decay. All identified lifetime components of NADH and FAD were found to be shorter in cancerous cells than in normal cells, no matter how they were measured under different extra‐cellular conditions (cells suspended in cuvette and cells attached on glass substrate), indicating that the changes in metabolism likely altered the subcellular milieu and potentially also affected the interaction of NADH and FAD with enzymes to which these cofactors were bound. The intensity ratio of NADH and FAD of cancerous cells was also shown to be larger than that of normal cells.

    更新日期:2020-02-18
  • Non‐invasive detection of nanoscale structural changes in cornea associated with corneal cross‐linking treatment
    J. Biophotonics (IF 3.763) Pub Date : 2020-02-17
    Yi Zhou; Sergey Alexandrov; Andrew Nolan; Nandan Das; Rajib Dey; Martin Leahy

    Corneal cross‐linking (CXL) using UVA irradiation with a riboflavin photosensitizer has grown from an interesting concept to a practical clinical treatment for corneal ectatic diseases globally, such as keratoconus. To characterize the corneal structural changes, existing methods such as X‐ray microscopy, transmission electron microscopy (TEM), histology and optical coherence tomography have been used. However, these methods have various drawbacks such as invasive detection, the impossibility for in vivo measurement, or limited resolution and sensitivity to structural alterations. Here, we report the application of over‐sampling nano‐sensitive optical coherence tomography (nsOCT) method for probing the corneal structural alterations. The results indicate that the spatial period increases slightly after 30 minutes riboflavin instillation but decreases significantly after 30 min UVA irradiation following the Dresden protocol. The proposed non‐invasive method can be implemented using the existing OCT system, without any additional components, for detecting nanoscale changes with the potential to assist diagnostic assessment during CXL treatment, and possibly to be a real‐time monitoring tool in clinics.

    更新日期:2020-02-18
  • A feasibility study of OCT for anatomical and vascular phenotyping of mouse embryo
    J. Biophotonics (IF 3.763) Pub Date : 2020-02-17
    Woo June Choi; A. Murat Maga; Eun Soo Kim; Ruikang K. Wang

    The embryo phenotyping of genetic murine model is invaluable when investigating functions of genes underlying embryonic development and birth defect. Although traditional imaging technologies such as ultrasound are very useful for evaluating phenotype of murine embryos, the use of advanced techniques for phenotyping is desirable to obtain more information from genetic research. This letter tests the feasibility of optical coherence tomography (OCT) as a high‐throughput phenotyping tool for murine embryos. 3‐D OCT imaging is performed for live and cleared mouse embryos in the late developmental stage (embryonic day 17.5). By using a dynamic focusing method and OCT angiography (OCTA) approach, our OCT imaging of the embryo exhibits rapid and clean visualization of organ structures deeper than 5 mm and complex microvasculature of perfused blood vessels in the murine embryonic body. This demonstration suggests that OCT imaging can be useful for comprehensively assessing embryo anatomy and angiography of genetically engineered mice.

    更新日期:2020-02-18
  • Acta Physiologica in numbers, performance indicators for 2019
    Acta Physiol. (IF 5.868) Pub Date : 2020-02-18
    P.B. Persson

    How to best measure journal performance remains a controversial issue. Routinely, the impact factor of the journal is taken, although this measure was never designed to reflect journal performance. The impact factor was developed as a tool for librarians in academia to sort out, which of the many very different journals may best suit the demands of their readers. As the annual impact factors are released in the middle of the year, we cannot yet share this value with you. However, our estimates indicate a similarly high impact factor as for the most recent years.

    更新日期:2020-02-18
  • Constitutive activity of a G protein‐coupled receptor, DRD1, contributes to human cerebral organoid formation
    Stem Cells (IF 5.614) Pub Date : 2020-02-18
    Qinying Wang; Xiaoxu Dong; Jing Lu; Tingting Hu; Gang Pei
    更新日期:2020-02-18
  • Theoretical potential for endometrial cancer prevention through primary risk factor modification: Estimates from the EPIC cohort
    Int. J. Cancer (IF 4.982) Pub Date : 2020-02-18
    Renée T. Fortner; Anika Hüsing; Laure Dossus; Anne Tjønneland; Kim Overvad; Christina C. Dahm; Patrick Arveux; Agnès Fournier; Marina Kvaskoff; Matthias B. Schulze; Manuela Bergmann; Antonia Trichopoulou; Anna Karakatsani; Carlo La Vecchia; Giovanna Masala; Valeria Pala; Amalia Mattiello; Rosario Tumino; Fulvio Ricceri; Carla H. van Gils; Evelyn M. Monninkhof; Catalina Bonet; José Ramón Quirós; Maria‐Jose Sanchez; Daniel‐Ángel Rodríguez‐Palacios; Aurelio B Gurrea; Pilar Amiano; Naomi E. Allen; Ruth C. Travis; Marc J. Gunter; Vivian Viallon; Elisabete Weiderpass; Elio Riboli; Rudolf Kaaks

    Endometrial cancer (EC) incidence rates vary ~10‐fold worldwide, in part due to variation in EC risk factor profiles. Using an EC risk model previously developed in the European EPIC cohort, we evaluated the prevention potential of modified EC risk factor patterns and whether differences in EC incidence between a European population and low‐risk countries can be explained by differences in these patterns. Predicted EC incidence rates were estimated over 10 years of follow‐up for the cohort before and after modifying risk factor profiles. Risk factors considered were: body mass index (BMI, kg/m2), use of postmenopausal hormone therapy (HT) and oral contraceptives (OC) (potentially modifiable); and, parity, ages at first birth, menarche and menopause (environmentally conditioned, but not readily modifiable). Modeled alterations in BMI (to all ≤23 kg/m2) and HT use (to all non‐HT users) profiles resulted in a 30% reduction in predicted EC incidence rates; individually, longer duration of OC use (to all ≥10 years) resulted in a 42.5% reduction. Modeled changes in not readily modifiable exposures (i.e., those not contributing to prevention potential) resulted in ≤24.6% reduction in predicted EC incidence. Women in the lowest decile of a risk score based on the evaluated exposures had risk similar to a low risk countries; however, this was driven by relatively long use of OCs (median = 23 years). Our findings support avoidance of overweight BMI and of HT use as prevention strategies for EC in a European population; OC use must be considered in the context of benefits and risks.

    更新日期:2020-02-18
  • Contralateral breast cancer risk in BRCA1 and BRCA2 mutation carriers in a large cohort of unselected Chinese breast cancer patients
    Int. J. Cancer (IF 4.982) Pub Date : 2020-02-18
    Liming Su; Ye Xu; Tao Ouyang; Jinfeng Li; Tianfeng Wang; Zhaoqing Fan; Tie Fan; Benyao Lin; Yuntao Xie

    To estimate the cumulative risk of contralateral breast cancer (CBC) in BRCA1/2 carriers in a large cohort of unselected Chinese breast cancer patients. Our study comprised 9,401 unselected Chinese breast cancer patients and BRCA1/2 germline mutations were determined in all patients. After a median follow‐up of 5.7 years, 181 patients developed CBC in this cohort. Compared to noncarriers, BRCA1 and BRCA2 carriers had a 4.52‐fold (95% CI, 2.63–7.76) and 5.54‐fold (95% CI, 3.51–8.74) increased risk of CBC, respectively. The 10‐year cumulative risk of CBC was 15.5% (95% CI, 9.9–24.2) for BRCA1 carriers, 17.5% (95% CI, 10.9–28.0) for BRCA2 carriers and 3.2% (95% CI, 2.5–4.1) for noncarriers. Younger age at first breast cancer diagnosis was significantly associated with an increased 10‐year risk of CBC for BRCA1 carriers (≤40 years vs. >40 years: 21.5% vs. 11.9%, unadjusted hazard ratio [HR] = 2.51, 95% CI, 1.03–6.15, p = 0.044), but not for BRCA2 carriers and noncarriers. The 10‐year cumulative CBC risk was significantly higher in both BRCA1 and BRCA2 carriers who had a family history of breast cancer than in those who did not (BRCA1: 27.5% vs. 9.4%, adjusted HR = 2.64, 95% CI, 1.01–6.97, p = 0.049; BRCA2: 27.1% vs. 12.8%, adjusted HR = 2.29, 95% CI, 1.04–5.06, p = 0.040). In conclusion, the risk of CBC was a substantial high in BRCA1/2 carriers in unselected Chinese breast cancer patients, and CBC risk is much more remarkable in both BRCA1 and BRCA2 carriers who had a family history of breast cancer. Younger age at first breast cancer diagnosis also enhanced CBC risk in BRCA1 carriers.

    更新日期:2020-02-18
  • Beyond the concept of cold and hot tumors for the development of novel predictive biomarkers and the rational design of immunotherapy combination
    Int. J. Cancer (IF 4.982) Pub Date : 2020-02-18
    Eleonore De Guillebon; Antoine Dardenne; Antonin Saldmann; Sylvie Séguier; Thi Tran; Lea Paolini; Celeste Lebbe; Eric Tartour

    Immunotherapy has revolutionized the management of cancers. At the end of 2018, 1,716 clinical trials assessed regimen that combine program death‐1 (PD‐1)/program death ligand‐1 (PD‐L1) blockers with other cancer therapies (tyrosine kinase inhibitor, chemotherapy and radiotherapy). There is a contrast between these clinical dynamics and the difficulty of identifying biomarkers to better select patients that could benefit from immunotherapy. In this context, different tumor classifications have been proposed to try to better stratify patients. They rely on the characteristics of the tumor microenvironment and led first to divide them into hot and cold tumors. In this review, we aim to demonstrate the limitations of this classification focusing on the differential significance of subpopulations of intratumor CD8 + T cells. We also underline novel mechanisms of resistance to anti‐PD‐1/PD‐L1 blockade, focusing on myeloid cells, hypoxia and tumor immunoediting under treatment. Understanding the mechanisms of resistance to immune‐checkpoint inhibitor is indeed a powerful research driver that allows further identification of novel biomarkers, drug development and bring a rational to innovative therapeutic combinations.

    更新日期:2020-02-18
  • Molecular profiling identifies synchronous endometrial and ovarian cancers as metastatic endometrial cancer with favorable clinical outcome
    Int. J. Cancer (IF 4.982) Pub Date : 2020-02-18
    Casper Reijnen; Heidi V.N. Küsters‐Vandevelde; Marjolijn J.L. Ligtenberg; Johan Bulten; Marloes Oosterwegel; Marc P.L.M. Snijders; Sanne Sweegers; Joanne A. de Hullu; Maria C. Vos; Anneke A.M. van der Wurff; Anne M. van Altena; Astrid Eijkelenboom; Johanna M.A. Pijnenborg

    Synchronous primary endometrial and ovarian cancers (SEOs) represent 10% of all endometrial and ovarian cancers and are assumed to develop as independent entities. We investigated the clonal relationship between endometrial and ovarian carcinomas in a large cohort classified as SEOs or metastatic disease (MD). The molecular profiles were compared to The Cancer Genome Atlas (TCGA) data to explore primary origin. Subsequently, the molecular profiles were correlated with clinical outcome. To this extent, a retrospective multicenter study was performed comparing patients with SEOs (n = 50), endometrial cancer with synchronous ovarian metastasis (n = 19) and ovarian cancer with synchronous endometrial metastasis (n = 20). Targeted next‐generation sequencing was used, and a clonality index was calculated. Subsequently, cases were classified as POLE mutated, mismatch repair deficient (MMR‐D), TP53‐wild‐type or TP53‐mutated. In 92% of SEOs (46/50), the endometrial and concurrent ovarian carcinoma shared at least one somatic mutation, with a clonality index above 0.95, supporting a clonal origin. The SEO molecular profiles showed striking similarities with the TCGA endometrial carcinoma set. SEOs behaved distinctly different from metastatic disease, with a superior outcome compared to endometrial MD cases (p < 0.001) and ovarian MD cases (p < 0.001). Classification according to the TCGA identified four groups with different clinical outcomes. TP53 mutations and extra‐utero‐ovarian disease were independent predictors for poor clinical outcome. Concluding, SEOs were clonally related in an overwhelming majority of cases and showed a favorable prognosis. Their molecular profile implied a primary endometrial origin. TP53 mutation and extra‐utero‐ovarian disease were independent predictors for outcome, and may impact adjuvant systemic treatment planning.

    更新日期:2020-02-18
  • Reproductive Factors and Risk of Breast Cancer by Tumor Subtypes among Ghanaian Women: A Population‐based Case–control Study
    Int. J. Cancer (IF 4.982) Pub Date : 2020-02-18
    Jonine D Figueroa; Brittny C Davis Lynn; Lawrence Edusei; Nicholas Titiloye; Ernest Adjei; Joe‐Nat Clegg‐Lamptey; Joel Yarney; Beatrice Wiafe‐Addai; Baffour Awuah; Maire A. Duggan; Seth Wiafe; Kofi Nyarko; Francis Aitpillah; Daniel Ansong; Stephen M Hewitt; Thomas Ahearn; Montserrat Garcia‐Closas; Louise A Brinton;

    Higher proportions of early‐onset and estrogen receptor (ER) negative cancers are observed in women of African ancestry than in women of European ancestry. Differences in risk factor distributions and associations by age at diagnosis and ER status may explain this disparity.

    更新日期:2020-02-18
  • Long‐Term Deaths From Melanoma According To Tumour Thickness At Diagnosis
    Int. J. Cancer (IF 4.982) Pub Date : 2020-02-17
    Peter D. Baade; David C. Whiteman; Monika Janda; Anne E. Cust; Rachel E. Neale; B. Mark Smithers; Adele C. Green; Kiarash Khosrotehrani; Victoria Mar; H. Peter Soyer; Joanne F. Aitken

    There is little long‐term follow‐up information about how the number of melanoma deaths and case‐fatality vary over time according to the measured thickness of melanoma at diagnosis. This population‐based longitudinal cohort study examines patterns and trends in case‐fatality among 44,531 people in Queensland (Australia) diagnosed with a single invasive melanoma (ICD‐O C44, Morphology 872–879) between 1987 and 2011, including 11,883 diagnosed between 1987 and 1996, with up to 20 years follow up (to December 2016). The 20‐year case fatality increased by thickness, with the percentage of melanoma deaths within 20 years of diagnosis being up to 4.8% for melanomas with measured thickness < 0.80 mm, 10.6% for tumours 0.8‐ < 1.0 mm, and generally more than 30% for melanomas measuring 3 mm and more. For melanomas <1.0 mm, most deaths occurred between 5 and 20 years after diagnosis, whereas for thicker melanomas the reverse was true with most deaths occurring within the first 5 years. Five‐year case‐fatality decreased over successive calendar time periods for melanomas <1.0 mm, but not for melanomas ≥1.0 mm. These findings demonstrate that the time course for fatal melanomas varies markedly according to tumour thickness at diagnosis. Improved understanding of the patient factors and characteristics of melanomas, in addition to tumour thickness, that increase the likelihood of progression, is needed to guide clinical diagnosis, communication with patients, and ongoing surveillance pathways of patients with potentially fatal lesions.

    更新日期:2020-02-18
  • Analysis of fusion transcripts indicates widespread deregulation of snoRNAs and their host genes in breast cancer
    Int. J. Cancer (IF 4.982) Pub Date : 2020-02-17
    Helena Persson; Rolf Søkilde; Jari Häkkinen; Johan Vallon‐Christersson; Felix Mitelman; åke Borg; Mattias Höglund; Carlos Rovira

    Genomic rearrangements in cancer can join the sequences of two separate genes. Studies of such gene fusion events have mainly focused on identification of fusion proteins from the chimeric transcripts. We have previously investigated how fusions instead can affect the expression of intronic microRNA (miRNA) genes that are encoded within fusion gene partners. Here, we extend our analysis to small nucleolar RNAs (snoRNAs) that also are embedded within protein‐coding or non‐coding host genes. We found that snoRNA hosts are selectively enriched in fusion transcripts, like miRNA host genes, and that this enrichment is associated with all snoRNA classes. These structural changes may have functional consequences for the cell; proteins involved in the protein translation machinery are overrepresented among snoRNA host genes, a gene architecture assumed to be needed for closely coordinated expression of snoRNAs and host proteins. Our data indicate that this structure is frequently disrupted in cancer. We furthermore observed that snoRNA genes involved in fusions tend to associate with stronger promoters than the natural host, suggesting a mechanism that selects for snoRNA overexpression. In summary, we highlight a previously unexplored frequent structural change in cancer that affects important components of cellular physiology.

    更新日期:2020-02-18
  • Pre‐diagnosis dietary pattern and survival in patients with multiple myeloma
    Int. J. Cancer (IF 4.982) Pub Date : 2020-02-17
    Dong Hoon Lee; Teresa T. Fung; Fred K. Tabung; Catherine R. Marinac; Elizabeth E. Devore; Bernard A. Rosner; Irene M. Ghobrial; Graham A. Colditz; Edward L. Giovannucci; Brenda M. Birmann

    Inflammation and endogenous growth factors are important in multiple myeloma (MM) pathogenesis. Although diets that modulate these biologic pathways may influence MM patient survival, studies have not examined the association of dietary pattern with MM survival. We conducted pooled prospective survival analyses of 423 MM patients from the Nurses’ Health Study (1986‐2016) and the Health Professionals Follow‐up Study (1988‐2016) using Cox regression models. We used data from repeated food frequency questionnaires (FFQ) to compute dietary patterns as of the last pre‐diagnosis FFQ, including the Alternate Healthy Eating Index (AHEI)‐2010, alternate Mediterranean Diet, Dietary Approaches to Stop Hypertension, Prudent, Western and empirical dietary inflammatory patterns and empirical dietary indices for insulin resistance and hyperinsulinemia. During follow‐up, we documented 295 MM‐related deaths among 345 total deaths. MM‐specific mortality was 15% to 24% lower per one standard deviation (SD) increase (e.g., towards healthier habits) in favorable dietary pattern scores. For example, the multivariable‐adjusted hazard ratio [HR] and 95% confidence interval [CI] per 1‐SD increase in AHEI‐2010 score were 0.76, 0.67 to 0.87 (P<.001). In contrast, MM‐specific mortality was 16% to 24% higher per 1‐SD increase (e.g., towards less healthy habits) in “unhealthy” diet scores; for example, the multivariable‐adjusted HR, 95% CI per 1‐SD increase in Western pattern score were 1.24, 1.07 to 1.44 (P=0.005). Associations were similar for all‐cause mortality. In conclusion, our consistent findings for multiple dietary patterns provide the first evidence that MM patients with healthier pre‐diagnosis dietary habits may have longer survival than those with less healthy diets.

    更新日期:2020-02-18
  • S1PR4‐dependent CCL2 production promotes macrophage recruitment in a murine psoriasis model
    Eur. J. Immunol. (IF 4.695) Pub Date : 2020-02-18
    Christian Schuster; Arnaud Huard; Evelyn Sirait‐Fischer; Christina Dillmann; Bernhard Brüne; Andreas Weigert
    更新日期:2020-02-18
  • CMTM7 plays key roles in TLR‐induced plasma cell differentiation and p38 activation in murine B‐1 B cells
    Eur. J. Immunol. (IF 4.695) Pub Date : 2020-02-18
    Zhengyang Liu; Yuan Liu; Ting Li; Pingzhang Wang; Xiaoning Mo; Ping Lv; Dalong Ma; Wenling Han
    更新日期:2020-02-18
  • Fibroblast transdifferentiation promotes conversion of M1 macrophages and replenishment of cardiac resident macrophages following cardiac injury in mice
    Eur. J. Immunol. (IF 4.695) Pub Date : 2020-02-18
    Hongxiang Lu; Rong Chen; Prince Amoah Barnie; Yu Tian; Shiqing Zhang; Huaxi Xu; Subrata Chakrabarti; Zhaoliang Su

    Resident cardiac macrophages play important roles in homeostasis, maintenance of cardiac function, and tissue repair. After cardiac injury, monocytes infiltrate the tissue, undergo phenotypic and functional changes, and are involved in inflammatory injury and functional remodelling. However, the fate of cardiac infiltrating/polarized macrophages and the relationship between these cells and resident cardiac macrophage replenishment following injury remain unclear. Our results showed that angiotensin II (ANG II) induces cardiac fibroblast transdifferentiation into cardiac myofibroblasts (MFBs). In co‐cultures with MFBs and murine macrophages, the MFBs promoted macrophage polarization to M1 phenotype, followed by selective apoptosis, which was associated with TNF/TNFR1 axis and independent of NO production. Surprisingly, after 36 h of co‐culture, the surviving macrophages were converted to M2 phenotype and settled in heart, which was dependent on leptin produced by MFBs or polarized macrophages via the PI3K or Akt pathway. CCR2+CD45.2+ cells adoptively transferred into CD45.1+ mice with viral myocarditis, differentiated into CD45.2+CCR2+CX3CR1+ M2 cells during the resolution of inflammation and settled within the heart. Our data highlight a novel mechanism related to the renewal or replenishment of cardiac resident macrophages following cardiac injury; and suggest that transdifferentiation of cardiac fibroblasts may promote the resolution of inflammation.

    更新日期:2020-02-18
  • Urologic complications after transplantation of 225 en bloc kidneys from small pediatric donors ≤20 kg: Incidence, management, and impact on graft survival
    Am. J. Transplant. (IF 7.163) Pub Date : 2020-02-18
    Ghaneh Fananapazir; Gary Tse; Ryan Di Geronimo; John McVicar; Richard Perez; Chandrasekar Santhanakrishnan; Junichiro Sageshima; Christoph Troppmann

    Pediatric en bloc kidney transplants (EBKs) from small deceased pediatric donors are associated with increased early graft loss and morbidity. Yet, urologic complications post‐EBK and their potential impact on graft survival have not been systematically studied. We retrospectively studied urological complications requiring intervention for 225 EBKs performed at our center January 2005 to September 2017 from donors ≤20 kg into recipients ≥18 years. Overall ureteral complication incidence after EBK was 9.8% (n = 22) (12% vs 2% for EBK donors 10 vs 10 kg, respectively [P = .031]). The most common post‐EBK urologic complication was a stricture (55%), followed by urine leak (41%). In all, 95% of all urologic complications occurred early within 5 months posttransplant (median, 138 days). Urologic complications could be successfully managed nonoperatively in 50% of all cases and had no impact on graft or patient survival. In summary, urologic complications after EBK were common, associated with lower donor weights, occurred early posttransplant, and were often amenable to nonoperative treatment, without adversely affecting survival. We conclude that the higher urologic complication rate after EBK (1) should not prevent increased utilization of small pediatric donor en bloc kidneys for properly selected recipients, and (2) warrants specific discussion with EBK recipients during the preoperative consent process.

    更新日期:2020-02-18
  • Obesity, transplantation, and bariatric surgery: An evolving solution for a growing epidemic
    Am. J. Transplant. (IF 7.163) Pub Date : 2020-02-18
    Tayyab S. Diwan; Tiffany C. Lee; Shunji Nagai; Enrico Benedetti; Andrew Posselt; Ginny Bumgardner; Sabrena Noria; Bryan A. Whitson; Lloyd Ratner; David Mason; Jon Friedman; Kenneth J. Woodside; Julie Heimbach

    The increasing obesity epidemic has major implications in the realm of transplantation. Patients with obesity face barriers in access to transplant and unique challenges in perioperative and postoperative outcomes. Because of comorbidities associated with obesity, along with the underlying end‐stage organ disease leading to transplant candidacy, these patients may not even be referred for transplant evaluation, much less be waitlisted or actually undergo transplant. However, the use of bariatric surgery in this population can help optimize the transplant candidacy of patients with obesity and end‐stage organ disease and improve perioperative and postoperative outcomes. We review the impact of obesity on kidney, liver, and cardiothoracic transplant candidates and recipients and explore potential interventions to address obesity in these populations.

    更新日期:2020-02-18
  • Modeling and field experiments on autonomous vehicle lane changing with surrounding human‐driven vehicles
    Comput. Aided Civ. Infrastruct. Eng. (IF 6.208) Pub Date : 2020-02-18
    Zhen Wang; Xiangmo Zhao; Zhigang Xu; Xiaopeng Li; Xiaobo Qu

    Autonomous vehicle (AV) technology is widely studied in both industrial and academic communities since it is regarded as a promising means for improving transportation safety and efficiency. Lane changing is a critical link for higher‐level AV operations. However, few studies on AV lane changing consider the dynamics of surrounding vehicles, particularly in a mixed traffic environment including human‐driven vehicles (HVs). Therefore, this article presents a dynamic lane‐changing model for AV incorporating human driver behavior in mixed traffic. The proposed model includes four key components: car following (and lane keeping), lane‐changing decision, dynamic trajectory generation, and model predictive control (MPC)‐based trajectory tracking. AV longitudinal control algorithm is also depicted in detail in this article. Field experiments are conducted on a large‐scale test track to test and validate the proposed model. An AV and three HVs are used in the lane‐changing experiments. Different human driver behaviors are considered in the experiment settings. Experimental results show that the proposed lane‐changing model can complete lane‐changing maneuvers efficiently when HVs are cooperative and can also robustly abort them when HVs are uncooperative. Compared with the measured human lane‐changing maneuvers, AV lane‐changing maneuvers from the proposed model are more comfortable and safer.

    更新日期:2020-02-18
  • Wavelet‐based approach of time series model for modal identification of a bridge with incomplete input
    Comput. Aided Civ. Infrastruct. Eng. (IF 6.208) Pub Date : 2020-02-17
    C. S. Huang; Q. T. Le; W. C. Su; C. H. Chen

    Identification of modal parameters of a bridge from its earthquake responses is crucial for performing damage assessment of the structure. However, all the input base excitations of the bridge may not be measured because of economic concerns and sensor malfunctions. Consequently, evaluating the modal parameters of a bridge under the consideration of incomplete input measurements is a challenging and important task. An approach that combines the continuous Cauchy wavelet transform with an autoregressive time‐varying moving average with exogenous input (AR‐TVMA‐X) model is proposed in this study to identify the modal parameters of a multispan bridge under multiple support earthquake excitations with incomplete measurements. The efficiency and efficacy of the proposed approach are first validated using numerically simulated responses of a three‐span continuous beam subjected to multiple support nonstationary excitations. A standard procedure of using the proposed approach to identify the modal parameters is established according to comprehensive studies on the effects of noise in the data, the number of supports whose excitations are used in the AR‐TVMA‐X model, and the orders of the AR‐TVMA‐X model on the accuracy of identifying the modal parameters. This procedure is further applied to process the earthquake responses of a two‐span cable‐stayed 510‐m‐long bridge to demonstrate the engineering applicability of the proposed approach.

    更新日期:2020-02-18
  • Beyond the limits of photoperception: constitutively active PHYTOCHROME B2 overexpression as a means of improving fruit nutritional quality in tomato
    Plant Biotech. J. (IF 6.840) Pub Date : 2020-02-18
    Frederico Rocha Rodrigues Alves; Bruno Silvestre Lira; Filipe Christian Pikart; Scarlet Santos Monteiro; Cláudia Maria Furlan; Eduardo Purgatto; Grazieli Benedetti Pascoal; Sónia Cristina da Silva Andrade; Diego Demarco; Magdalena Rossi; Luciano Freschi

    Photoreceptor engineering has recently emerged as a means for improving agronomically beneficial traits in crop species. Despite the central role played by the red/far‐red photoreceptor phytochromes (PHYs) in controlling fruit physiology, the applicability of PHY engineering for increasing fleshy fruit nutritional content remains poorly exploited. In this study, we demonstrated that the fruit‐specific overexpression of a constitutively active GAF domain Tyr252‐to‐His PHYB2 mutant version (PHYB2Y252H) significantly enhances the accumulation of multiple health‐promoting antioxidants in tomato fruits, without negative collateral consequences on vegetative development. Compared to the native PHYB2 overexpression, PHYB2Y252H‐overexpressing lines exhibited more extensive increments in transcript abundance of genes associated with fruit plastid development, chlorophyll biosynthesis and metabolic pathways responsible for the accumulation of antioxidant compounds. Accordingly, PHYB2Y252H‐overexpressing fruits developed more chloroplasts containing voluminous grana at the green stage and overaccumulated carotenoids, tocopherols, flavonoids and ascorbate in ripe fruits compared to both wildtype and PHYB2‐overexpressing lines. The impacts of PHYB2 or PHYB2Y252H‐overexpression on fruit primary metabolism were limited to a slight promotion in lipid biosynthesis and reduction in sugar accumulation. Altogether, these findings indicate that mutation‐based adjustments in PHY properties represent a valuable photobiotechnological tool for tomato biofortification, highlighting the potential of photoreceptor engineering for improving quality traits in fleshy fruits.

    更新日期:2020-02-18
  • SUMOylation of MYB30 enhances salt tolerance by elevating alternative respiration via transcriptionally upregulating AOX1a in Arabidopsis
    Plant J. (IF 5.726) Pub Date : 2020-02-18
    Qianyuan Gong; Sha Li; Yuan Zheng; Hongqin Duan; Fei Xiao; Yufen Zhuang; Jiaxian He; Guochun Wu; Shuangshuang Zhao; Huapeng Zhou; Honghui Lin

    Salt stress reduces crop growth and productivity globally. Here we report that a R2R3‐MYB transcription factor MYB30 participates in salt tolerance in Arabidopsis. MYB30 can be SUMOylated by SIZ1 in response to salt stress and the lysine (K)283 of MYB30 is essential for its SUMOylation. In contrast to wild‐type MYB30, the MYB30K283R mutant failed to rescue the salt‐sensitive phenotype of the myb30‐2 mutant, indicating that SUMOylation of MYB30 is required for the salt‐stress response. Through transcriptomic analysis, we identified a MYB30 target, alternative oxidase 1a (AOX1a). MYB30 binds the promoter of AOX1a and upregulates its expression in response to salt stress; however, MYB30K283R cannot bind the promoter of AOX1a. The cyanide (CN)‐resistant alternative respiration (Alt) mediated by AOX is significantly reduced in the myb30‐2 mutant through the loss of function of MYB30. As a result, the redox homeostasis is disrupted in the myb30‐2 mutant compared with that in wild‐type seedlings (WT) under salt conditions. The artificial elimination of excess reactive oxygen species partially rescues the salt‐sensitive phenotype of the myb30‐2 mutant, whereas after the exogenous application of SHAM, an inhibitor of AOXs and Alt respiration, the salt tolerance of Col‐0 and the complemented plants decreased to a level similar to that observed in myb30‐2. Finally, overexpression of AOX1a in myb30‐2 confers WT‐like salt tolerance compared with that of the myb30‐2 mutant. Taken together, our results revealed a functional link between MYB30 and AOX1a, and indicated that SIZ1‐mediated SUMOylation of MYB30 enhances salt tolerance by regulating Alt respiration and cellular redox homeostasis via AOX1a in Arabidopsis.

    更新日期:2020-02-18
  • Model approaches to advance crassulacean acid metabolism system integration
    Plant J. (IF 5.726) Pub Date : 2020-02-18
    Methawi Chomthong; Howard Griffiths

    This review summarises recent progress in understanding crassulacean acid metabolism (CAM) systems and the integration of internal and external stimuli to maximise water‐use efficiency. Complex CAM traits have been reduced to their minimum and captured as computational models, which can now be refined using recently available data from transgenic manipulations and large‐scale omics studies. We identify three key areas in which an appropriate choice of modelling tool could help capture relevant comparative molecular data to address the evolutionary drivers and plasticity of CAM. One focus is to identify the environmental and internal signals that drive inverse stomatal opening at night. Secondly, it is important to identify the regulatory processes required to orchestrate the diel pattern of carbon fluxes within mesophyll layers. Finally, the limitations imposed by contrasting succulent systems and associated hydraulic conductance components should be compared in the context of water‐use and evolutionary strategies. While network analysis of transcriptomic data can provide insights via co‐expression modules and hubs, alternative forms of computational modelling should be used iteratively to define the physiological significance of key components and informing targeted functional gene manipulation studies. We conclude that the resultant improvements of bottom‐up, mechanistic modelling systems can enhance progress towards capturing the physiological controls for phylogenetically diverse CAM systems in the face of the recent surge of information in this omics era.

    更新日期:2020-02-18
  • A rapid and quantitative safranin‐based fluorescent microscopy method to evaluate cell wall lignification
    Plant J. (IF 5.726) Pub Date : 2020-02-18
    Fabien Baldacci‐Cresp; Corentin Spriet; Laure Twyffels; Anne‐Sophie Blervacq; Godfrey Neutelings; Marie Baucher; Simon Hawkins

    One of the main characteristics of plant cells is the presence of the cell wall located outside the plasma membrane. In particular cells, this wall can be reinforced by lignin, a polyphenolic polymer that plays a central role for vascular plants, conferring hydrophobicity to conducting tissues and mechanical support for upright growth. Lignin has been studied extensively by a range of different techniques, including anatomical and morphological analyses using dyes to characterize the polymer localization in situ. With the constant improvement of imaging techniques, it is now possible to revisit old qualitative techniques and adapt them to obtain efficient, highly resolutive, quantitative, fast and safe methodologies. In this study, we revisit and exploit the potential of fluorescent microscopy coupled to safranin‐O staining to develop a quantitative approach for lignin content determination. The developed approach is based on ratiometric emission measurements and the development of an imagej macro. To demonstrate the potential of our methodology compared with other commonly used lignin reagents, we demonstrated the use of safranin‐O staining to evaluate and compare lignin contents in previously characterized Arabidopsis thaliana lignin biosynthesis mutants. In addition, the analysis of lignin content and spatial distribution in the Arabidopsis laccase mutant also provided new biological insights into the effects of laccase gene downregulation in different cell types. Our safranin‐O‐based methodology, also validated for Linum usitatissimum (flax), Zea mays (maize) and Populus tremula x alba (poplar), significantly improves and speeds up anatomical and developmental investigations of lignin, which we hope will contribute to new discoveries in many areas of cell wall plant research.

    更新日期:2020-02-18
  • Plant species‐specific recognition of long and short β‐1,3‐linked glucans is mediated by different receptor systems
    Plant J. (IF 5.726) Pub Date : 2020-02-18
    Alan Wanke; Hanna Rovenich; Florian Schwanke; Stefanie Velte; Stefan Becker; Jan‐Hendrik Hehemann; Stephan Wawra; Alga Zuccaro

    Plants survey their environment for the presence of potentially harmful or beneficial microbes. During colonization, cell surface receptors perceive microbe‐derived or modified‐self ligands and initiate appropriate responses. The recognition of fungal chitin oligomers and the subsequent activation of plant immunity are well described. In contrast, the mechanisms underlying β‐glucan recognition and signaling activation remain largely unexplored. Here, we systematically tested immune responses towards different β‐glucan structures and show that responses vary between plant species. While leaves of the monocots Hordeum vulgare and Brachypodium distachyon can recognize longer (laminarin) and shorter (laminarihexaose) β‐1,3‐glucans with responses of varying intensity, duration and timing, leaves of the dicot Nicotiana benthamiana activate immunity in response to long β‐1,3‐glucans, whereas Arabidopsis thaliana and Capsella rubella perceive short β‐1,3‐glucans. Hydrolysis of the β‐1,6 side‐branches of laminarin demonstrated that not the glycosidic decoration but rather the degree of polymerization plays a pivotal role in the recognition of long‐chain β‐glucans. Moreover, in contrast to the recognition of short β‐1,3‐glucans in A. thaliana, perception of long β‐1,3‐glucans in N. benthamiana and rice is independent of CERK1, indicating that β‐glucan recognition may be mediated by multiple β‐glucan receptor systems.

    更新日期:2020-02-18
  • Photorespiration in the context of Rubisco biochemistry, CO2 diffusion and metabolism
    Plant J. (IF 5.726) Pub Date : 2020-02-18
    Florian A. Busch

    Photorespiratory metabolism is essential for plants to maintain functional photosynthesis in an oxygen‐containing environment. Because the oxygenation reaction of Rubisco is followed by the loss of previously fixed carbon, photorespiration is often considered a wasteful process and considerable efforts are aimed at minimizing the negative impact of photorespiration on the plant’s carbon uptake. However, the photorespiratory pathway has also many positive aspects, as it is well integrated within other metabolic processes, such as nitrogen assimilation and C1 metabolism, and it is important for maintaining the redox balance of the plant. The overall effect of photorespiratory carbon loss on the net CO2 fixation of the plant is also strongly influenced by the physiology of the leaf related to CO2 diffusion. This review outlines the distinction between Rubisco oxygenation and photorespiratory CO2 release as a basis to evaluate the costs and benefits of photorespiration.

    更新日期:2020-02-18
  • Estimating photosynthetic traits from reflectance spectra: A synthesis of spectral indices, numerical inversion, and partial least square regression
    Plant Cell Environ. (IF 5.624) Pub Date : 2020-01-10
    Peng Fu; Katherine Meacham‐Hensold; Kaiyu Guan; Jin Wu; Carl Bernacchi

    The lack of efficient means to accurately infer photosynthetic traits constrains understanding global land carbon fluxes and improving photosynthetic pathways to increase crop yield. Here we investigated whether a hyperspectral imaging camera mounted on a mobile platform could provide the capability to help resolve these challenges, focusing on three main approaches, i.e., reflectance spectra‐, spectral indices‐, and numerical model inversions‐based partial least square regression (PLSR) to estimate photosynthetic traits from canopy hyperspectral reflectance for eleven tobacco cultivars. Results showed that PLSR with inputs of reflectance spectra or spectral indices yielded a R2 of ~0.8 for predicting Vcmax and Jmax, higher than a R2 of ~0.6 provided by PLSR of numerical inversions. Compared to PLSR of reflectance spectra, PLSR with spectral indices exhibited a better performance for predicting Vcmax (R2 = 0.84 ± 0.02, RMSE = 33.8 ± 2.2 𝜇𝑚𝑜𝑙 𝑚−2 𝑠−1) while a similar performance for Jmax (R2 = 0.80 ± 0.03, RMSE = 22.6 ± 1.6 𝜇𝑚𝑜𝑙 𝑚−2 𝑠−1). Further analysis on spectral resampling revealed that Vcmax and Jmax could be predicted with ~10 spectral bands at spectral resolution less than 14.7 nm. These results have important implications for improving photosynthetic pathways and mapping of photosynthesis across scales.

    更新日期:2020-02-18
  • Spontaneous emission of volatiles from the male flowers of the early-branching angiosperm Amborella trichopoda
    Planta (IF 3.060) Pub Date : 2020-02-18
    Lorenzo Peruzzi, Francesco Roma-Marzio, Guido Flamini

    Abstract Main conclusion Volatile emissions were detected for the first time in male flowers of the early-branching angiosperm Amborella trichopoda, suggesting a defensive and attractive double role of these compounds. Abstract Flower volatile emissions were detected for the first time in male flowers of the early-branching angiosperm Amborella trichopoda. A mixture of seven volatile compounds is found in flower buds, with limonene resulting as the most abundant compound (67%). Further five volatiles are found in freshly opened flowers, with limonene contributing to 31.7%, followed by decanal (15.5%) and by ethyl octanoate (10.3%). While monoterpene hydrocarbons dominate in flower buds (73.6%), their emission in freshly opened flowers is reduced to 41.1%, while non-terpene derivatives are the most abundant (47.1%) chemical class. These compounds, emitted in low amounts, are possibly linked to pollen, which is considered the only reward offered for insect-pollination in this species.

    更新日期:2020-02-18
  • Temporal dynamics of migration‐linked genetic variation are driven by streamflows and riverscape permeability
    Mol. Ecol. (IF 5.855) Pub Date : 2020-02-17
    Suzanne J. Kelson; Michael R. Miller; Tasha Q. Thompson; Sean M. O’Rourke; Stephanie M. Carlson

    Landscape permeability is often explored spatially, but may also vary temporally. Landscape permeability, including partial barriers, influences migratory animals that move across the landscape. Partial barriers are common in rivers where barrier passage varies with streamflow. We explore the influence of partial barriers on the spatial and temporal distribution of migration‐linked genotypes of Oncorhynchus mykiss, a salmonid fish with co‐occurring resident and migratory forms, in tributaries to the South Fork Eel River, California, USA, Elder and Fox Creeks. We genotyped >4,000 individuals using RAD‐capture and classified individuals as resident, heterozygous or migratory genotypes using life history‐associated loci. Across four years of study (2014–2017), the permeability of partial barriers varied across dry and wet years. In Elder Creek, the largest waterfall was passable for adults migrating up‐river 4–39 days each year. In this stream, the overall spatial pattern, with fewer migratory genotypes above the waterfall, remained true across dry and wet years (67%–76% of migratory alleles were downstream of the waterfall). We also observed a strong relationship between distance upstream and proportion of migratory alleles. In Fox Creek, the primary barrier is at the mouth, and we found that the migratory allele frequency varied with the annual timing of high flow events. In years when rain events occurred during the peak breeding season, migratory allele frequency was high (60%–68%), but otherwise it was low (30% in two years). We highlight that partial barriers and landscape permeability can be temporally dynamic, and this effect can be observed through changing genotype frequencies in migratory animals.

    更新日期:2020-02-18
  • Gene family expansion of pinewood nematode to detoxify its host defence chemicals
    Mol. Ecol. (IF 5.855) Pub Date : 2020-02-17
    Wei Zhang; Haiying Yu; Yunxue Lv; Kathryn E. Bushley; Jacob D. Wickham; Shenghan Gao; Songnian Hu; Lilin Zhao; Jianghua Sun

    Gene gain/loss in the context of gene family dynamics plays an important role in evolutionary processes as organisms, particularly invasive species, adapt to new environments or niches. One notable example of this is the duplication of digestive proteases in some parasitic insects and helminths to meet nutritional requirements during animal parasitism. However, whether gene family expansion participates in the adaptation of a plant parasite nematode to its host remains unknown. Here, we compared the newly sequenced genomes of the pinewood nematode, Bursaphelenchus xylophilus, with the genomes of free‐living, animal‐parasitic and plant‐parasitic nematodes. The results showed gene expansions occurring in 51 gene families in B. xylophilus, especially in xenobiotic detoxification pathways, including flavin monooxygenase (FMO), cytochrome P450 (CYP450), short chain dehydrogenase (SDR), alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH), UDP‐glucuronosyltransferase (UGT) and glutathione S‐transferase (GST). Although a majority of these expansions probably resulted from gene duplications, nine ADH genes were potentially acquired by horizontal gene transfer (HGT) from fungi. From the transcriptomes of B. xylophilus treated with pine saplings and terpenes, candidate xenobiotic detoxification genes were identified. We propose that host defence chemicals led to gene family expansions of xenobiotic detoxification pathways in B. xylophilus facilitating its survival in pine resin ducts. This study contributes to a better understanding of how a parasitic nematode adapts to its host.

    更新日期:2020-02-18
  • Corals in the hottest reefs in the world exhibit symbiont fidelity not flexibility
    Mol. Ecol. (IF 5.855) Pub Date : 2020-02-17
    Emily J. Howells; Andrew G. Bauman; Grace O. Vaughan; Benjamin C. C. Hume; Christian R. Voolstra; John A. Burt

    Reef‐building corals are at risk of extinction from ocean warming. While some corals can enhance their thermal limits by associating with dinoflagellate photosymbionts of superior stress tolerance, the extent to which symbiont communities will reorganize under increased warming pressure remains unclear. Here we show that corals in the hottest reefs in the world in the Persian Gulf maintain associations with the same symbionts across 1.5 years despite extreme seasonal warming and acute heat stress (≥35°C). Persian Gulf corals predominantly associated with Cladocopium (clade C) and most also hosted Symbiodinium (clade A) and/or Durusdinium (clade D). This is in contrast to the neighbouring and milder Oman Sea, where corals associated with Durusdinium and only a minority hosted background levels of Cladocopium. During acute heat stress, the higher prevalence of Symbiodinium and Durusdinium in bleached versus nonbleached Persian Gulf corals indicates that genotypes of these background genera did not confer bleaching resistance. Within symbiont genera, the majority of ITS2 rDNA type profiles were unique to their respective coral species, confirming the existence of host‐specific symbiont lineages. Notably, further differentiation among Persian Gulf sites demonstrates that symbiont populations are either isolated or specialized over tens to hundreds of kilometres. Thermal tolerance across coral species was associated with the prevalence of a single ITS2 intragenomic sequence variant (C3gulf), definitive of the Cladocopium thermophilum group. The abundance of C3gulf was highest in bleaching‐resistant corals and at warmer sites, potentially indicating a specific symbiont genotype (or set of genotypes) that may play a role in thermal tolerance that warrants further investigation. Together, our findings indicate that co‐evolution of host–Symbiodiniaceae partnerships favours fidelity rather than flexibility in extreme environments and under future warming.

    更新日期:2020-02-18
  • Congruent population genetic structures and divergence histories in anther‐smut fungi and their host plants Silene italica and the S. nutans species complex
    Mol. Ecol. (IF 5.855) Pub Date : 2020-02-18
    Fanny E. Hartmann; Alodie Snirc; Amandine Cornille; Cécile Godé; Pascal Touzet; Fabienne Van Rossum; Elisabeth Fournier; Stéphanie Le Prieur; Jacqui Shykoff; Tatiana Giraud

    The study of population genetic structure congruence between hosts and pathogens gives important insights into their shared phylogeographic and coevolutionary histories. We studied the population genetic structure of castrating anther‐smut fungi (Microbotryum genus) and of their host plants, the Silene nutans species complex, and the morphologically and genetically close S. italica, which can be found in sympatry. Phylogeographic population genetic structure related to persistence in separate glacial refugia has been recently revealed in the S. nutans plant species complex across Western Europe, identifying several distinct lineages. We genotyped 171 associated plant‐pathogen pairs of anther‐smut fungi and their host plant individuals using microsatellite markers and plant chloroplastic SNPs. We found clear differentiation between fungal populations parasitizing S. nutans and S. italica plants. The population genetic structure of fungal strains parasitizing the S. nutans plant species complex mirrored the host plant genetic structure, suggesting that the pathogen was isolated in glacial refugia together with its host and/or that it has specialized on the plant genetic lineages. Using random forest approximate Bayesian computation (ABC‐RF), we found that the divergence history of the fungal lineages on S. nutans was congruent with the one previously inferred for the host plant and likely occurred with ancient but no recent gene flow. Genome sequences confirmed the genetic structure and the absence of recent gene flow between fungal genetic lineages. Our analyses of host‐pathogen individual pairs contribute to a better understanding of co‐evolutionary histories between hosts and pathogens in natural ecosystems, in which such studies are still scarce.

    更新日期:2020-02-18
  • Evidence for widespread selection in shaping the genomic landscape during speciation of Populus
    Mol. Ecol. (IF 5.855) Pub Date : 2020-02-18
    Jing Wang; Nathaniel R. Street; Eung‐Jun Park; Jianquan Liu; Pär K. Ingvarsson

    Increasing our understanding of how evolutionary processes drive the genomic landscape of variation is fundamental to a better understanding of the genomic consequences of speciation. However, genome‐wide patterns of within‐ and between‐ species variation have not been fully investigated in most forest tree species despite their global ecological and economic importance. Here, we use whole‐genome resequencing data from four Populus species spanning the speciation continuum to reconstruct their demographic histories and investigate patterns of diversity and divergence within and between species. Using P. trichocarpa as an outgroup species, we further infer the genealogical relationships and estimate the extent of ancient introgression among the three aspen species (P. tremula, P. davidiana and P. tremuloides) throughout the genome. Our results show substantial variation in these patterns along the genomes with this variation being strongly predicted by local recombination rates and the density of functional elements. This implies that the interaction between recurrent selection and intrinsic genomic features has dramatically sculpted the genomic landscape over long periods of time. In addition, our findings provide evidence that, apart from background selection, recent positive selection and long‐term balancing selection have also been crucial components in shaping patterns of genome‐wide variation during the speciation process.

    更新日期:2020-02-18
  • Expanding 3d N$$ \mathcal{N} $$ = 2 theories around the round sphere
    J. High Energy Phys. (IF 5.833) Pub Date : 2020-02-18
    Dongmin Gang, Masahito Yamazaki

    Abstract We study a perturbative expansion of the squashed 3-sphere \( \left({s}_b^3\right) \) partition function of 3d \( \mathcal{N} \) = 2 gauge theories around the squashing parameter b = 1. Our proposal gives the coefficients of the perturbative expansion as a finite sum over the saddle points of the supersymmetric-localization integral in the limit b → 0 (the so-called Bethe vacua), and the contribution from each Bethe vacua can be systematically computed using saddle-point methods. Our expansion provides an efficient and practical method for computing basic CFT data (F, CT, CJJ and higher-point correlation functions of the stress-energy tensor) of the IR superconformal field theory without performing the localization integrals.

    更新日期:2020-02-18
  • Generation of vortices and stabilization of vortex lattices in holographic superfluids
    J. High Energy Phys. (IF 5.833) Pub Date : 2020-02-18
    Xin Li, Yu Tian, Hongbao Zhang

    Abstract Within the simplest holographic superfluid model and without any ingredient put by hand, it is shown that vortices can be generated when the angular velocity of rotating superfluids exceeds certain critical values, which can be precisely determined by linear perturbation analyses (quasi-normal modes of the bulk AdS black brane). These vortices appear at the edge of the superfluid system first, and then automatically move into the bulk of the system, where they are eventually stabilized into certain vortex lattices. For the case of 18 vortices generated, we find (at least) five different patterns of the final lattices formed due to different initial perturbations, which can be compared to the known result for such lattices in weakly coupled Bose-Einstein condensates from free energy analyses.

    更新日期:2020-02-18
  • Heavy holographic QCD
    J. High Energy Phys. (IF 5.833) Pub Date : 2020-02-17
    Nicolas Kovensky, Andreas Schmitt

    Abstract We study the phase structure of the Witten-Sakai-Sugimoto model in the plane of temperature and baryon chemical potential, including the effect of a nonzero current quark mass. Our study is performed in the decompactified limit of the model, which, at least regarding the chiral phase transition, appears to be closer to real-world QCD than the original version. Following earlier studies, we account for the quark mass in an effective way based on an open Wilson line operator whose expectation value is identified with the chiral condensate. We find that the quark mass stabilizes a configuration with string sources and point out that this phase plays an important role in the phase diagram. Furthermore, we show that the quark mass breaks up the first-order chiral phase transition curve and introduces critical points to the phase diagram. Similarities of the phase structure to other holographic approaches and to lattice simulations of “heavy QCD” are found and discussed. By making holographic QCD more realistic, our results open the door to a better understanding of real-world strongly coupled hot and dense matter.

    更新日期:2020-02-18
  • Bootstrapping inflationary correlators in Mellin space
    J. High Energy Phys. (IF 5.833) Pub Date : 2020-02-17
    Charlotte Sleight, Massimo Taronna

    Abstract We develop a Mellin space approach to boundary correlation functions in anti-de Sitter (AdS) and de Sitter (dS) spaces. Using the Mellin-Barnes representation of correlators in Fourier space, we show that the analytic continuation between AdSd+1 and dSd+1 is encoded in a collection of simple relative phases. This allows us to determine the late-time tree-level three-point correlators of spinning fields in dSd+1 from known results for Witten diagrams in AdSd+1 by multiplication with a simple trigonometric factor. At four point level, we show that Conformal symmetry fixes exchange four-point functions both in AdSd+1 and dSd+1 in terms of the dual Conformal Partial Wave (which in Fourier space is a product of boundary three-point correlators) up to a factor which is determined by the boundary conditions. In this work we focus on late-time four-point correlators with external scalars and an exchanged field of integer spin-ℓ. The Mellin-Barnes representation makes manifest the analytic structure of boundary correlation functions, providing an analytic expression for the exchange four-point function which is valid for general d and generic scaling dimensions, in particular massive, light and (partially-)massless fields. It moreover naturally identifies boundary correlation functions for generic fields with multi-variable Meijer-G functions. When d = 3 we reproduce existing explicit results available in the literature for external conformally coupled and massless scalars. From these results, assuming the weak breaking of the de Sitter isometries, we extract the corresponding correction to the inflationary three-point function of general external scalars induced by a general spin- ℓ field at leading order in slow roll. These results provide a step towards a more systematic understanding of de Sitter observables at tree level and beyond using Mellin space methods.

    更新日期:2020-02-18
  • Probing the decoupled seesaw scalar in rare Higgs boson decay
    J. High Energy Phys. (IF 5.833) Pub Date : 2020-02-17
    Yu Gao, Mingjie Jin, Kechen Wang

    Abstract The Higgs boson can mix with a singlet scalar that dynamically generates the Majorana mass of the right-handed neutrino NR. We show that even a tiny mixing between the Higgs boson and a ‘decoupled’ singlet scalar allows for Higgs-mediated pair production of NR without significant mixings between the active neutrinos and NR, and thus testable at colliders via a characteristic signal of two same-sign same-flavor lepton pairs, plus missing energy. We demonstrate that this search channel is mostly background- free in pp-collision and can be a highly sensitive probe of the Higgs-singlet mixing at the current and future pp colliders. Such channel provides a clean signal to discover the singlet scalar and explore the origin of neutrino masses.

    更新日期:2020-02-18
  • Conformally-regulated direct integration of the two-loop heptagon remainder
    J. High Energy Phys. (IF 5.833) Pub Date : 2020-02-17
    Jacob L. Bourjaily, Matthias Volk, Matt von Hippel

    Abstract We reproduce the two-loop seven-point remainder function in planar, maximally supersymmetric Yang-Mills theory by direct integration of conformally-regulated chiral integrands. The remainder function is obtained as part of the two-loop logarithm of the MHV amplitude, the regularized form of which we compute directly in this scheme. We compare the scheme-dependent anomalous dimensions and related quantities in the conformal regulator with those found for the Higgs regulator.

    更新日期:2020-02-18
  • New A 4 lepton flavor model from S 4 modular symmetry
    J. High Energy Phys. (IF 5.833) Pub Date : 2020-02-17
    Tatsuo Kobayashi, Yusuke Shimizu, Kenta Takagi, Morimitsu Tanimoto, Takuya H. Tatsuishi

    Abstract We study a flavor model with A4 symmetry which originates from S4 modular group. In S4 symmetry, Z2 subgroup can be anomalous, and then S4 can be violated to A4. Starting with a S4 symmetric Lagrangian at the tree level, the Lagrangian at the quantum level has only A4 symmetry when Z2 in S4 is anomalous. We obtain modular forms of two singlets and a triplet representations of A4 by decomposing S4 modular forms into A4 representations. We propose a new A4 flavor model of leptons by using those A4 modular forms. We succeed in constructing a viable neutrino mass matrix through the Weinberg operator for both normal hierarchy (NH) and inverted hierarchy (IH) of neutrino masses. Our predictions of the CP violating Dirac phase δCP and the mixing sin2θ23 depend on the sum of neutrino masses for NH.

    更新日期:2020-02-18
  • Study of effects of fipronil and fipronil sulphone on meat nutritional quality and validation of confirmatory GC‐MS/MS method for their analysis
    Int. J. Food Sci. Tech. (IF 2.281) Pub Date : 2020-02-17
    Valeria Nardelli; Marzia Albenzio; Giuseppe Gesualdo; Francesca d’Angelo; Antonella della Malva; Ines Della Rovere; Alessandro Scarpiello; Francesco Casamassima; Rosaria Marino
    更新日期:2020-02-18
Contents have been reproduced by permission of the publishers.
导出
全部期刊列表>>
化学/材料学中国作者研究精选
Springer Nature 2019高下载量文章和章节
ACS材料视界
南京大学
自然科研论文编辑服务
剑桥大学-
中国科学院大学化学科学学院
南开大学化学院周其林
课题组网站
X-MOL
北京大学分子工程苏南研究院
华东师范大学分子机器及功能材料
中山大学化学工程与技术学院
试剂库存
天合科研
down
wechat
bug