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A synthesis of the Cretaceous wildfire record related to atmospheric oxygen levels?

Journal of Palaeogeography 2024年第1期13卷 149-164页

作者： Da-Wei Lü Wen-Xu Du Zhi-Hui Zhang Yuan Gao tian-tian Wang Jin-Cheng Xu Ao-Cong Zhang Cheng-Shan Wang Shandong Provincial Key Laboratory of Depositional Mineralization and Sedimentary Minerals College of Earth Sciences and EngineeringShandong University of Science and TechnologyQingdao 266590Shandong ProvinceChina School of Earth Sciences and Resources China University of GeosciencesBejing 100083China Institute of Earth Sciences China University of Geosciences(Bejing)Beijing 100083China

The Cretaceous was a significant greenhouse period in Earth's history with higher atmospheric CO_(2) levels and temperatures than today. Although evidence of combustion has been widely described from the Cretaceous deposits, our understanding of the spatiotemporal diversification pattern and process of the Cretaceous wildfires is still limited. In this study, we comprehensively synthesize a total of 271 published Cretaceous wildfire occurrences based on the by-products of burning, including fossil charcoal, pyrogenic inertinite(fossil charcoal in coal), and pyrogenic polycyclic aromatic hydrocarbons(PAHs). Spatially, the dataset shows a distinctive distribution of reported wildfire evidence characterized by high concentration in the middle latitudinal areas of the Northern Hemisphere(30°N-60°N) over the Cretaceous. Temporally, an overall increasing trend of the reported wildfire data from the Early Cretaceous to the Late Cretaceous is coincident with higher atmospheric O_(2) levels. However, the spatial and temporal patterns may result from many types of factors, such as taphonomy, preservation, and researcher biases, instead of a real picture of the Cretaceous wildfire evolution. To better understand the spatiotemporal diversification of the Cretaceous wildfire, more investigations on the record of wildfire occurrences during this period would be necessary in the future.

关键词： Wildfire Cretaceous Atmospheric oxygen Taphonomy Charcoal

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A viral movement protein targets host catalases for 26S proteasome-mediated degradation to facilitate viral infection and aphid transmission in wheat

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Molecular Plant 2024年第4期17卷 614-630页

作者： Shuyuan tian Qingting Song Wenmei Zhou Jingke Wang Yanbin Wang Wei An Yunfeng Wu Lei Zhao State Key Laboratory for Crop Stress Resistance and High-Efficiency Production College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxi 712100China Key Laboratory of Integrated Pest Management on Crops in Northwestern Loess Plateau Ministry of Agriculture and Rural AffairsCollege of Plant ProtectionNorthwest A&F UniversityYanglingShaanxi 712100China Key Laboratory of Plant Protection Resources and Pest Management Ministry of EducationCollege of Plant ProtectionNorthwest A&F UniversityYanglingShaanxi 712100China

The infection of host plants by many different viruses causes reactive oxygen species(Ros)accumulation and yellowing symptoms,but the mechanisms through which plant viruses counteract RoS-mediated immunity to facilitate infection and symptom development have not been fully elucidated.Most plant viruses are transmitted by insect vectors in the field,but the molecular mechanisms underlying virus-host-insect interactions are unclear.In this study,we investigated the interactions among wheat,barley yellow dwarf virus(BYDV),and its aphid vector and found that the BYDV movement protein(MP)interacts with both wheat catalases(CATs)and the 26S proteasomeubiquitin receptor non-ATPase regulatorysubunit2homolog(PSMD2)to facilitate the 26S proteasome-mediateddegradation of CATs,promotingviral infection,disease symptom development,and aphid transmission.Overexpression of the BYDV MP gene in wheat enhanced the degradation of CATs,which leading to increased accumulation of ROS and thereby enhanced viral infection.Interestingly,transgenic wheat lines overexpressing BYDV MP showed significantly reduced proliferation of wingless aphids and an increased number of winged aphids.Consistent with this observation,silencing of CAT genes also enhanced viral accumulation and reduced the proliferation of wingless aphids but increased the occurrence of winged aphids.In contrast,transgenic wheat plants overexpressing TaCAT1 exhibited the opposite changes and showed increases in grain size and weight upon infection with BYDV.Biochemical assays demonstrated that BYDV MP interacts with PSMD2 and promotes 26S proteasome-mediated degradation of TaCAT1 likely in a ubiquitination-independent manner.Collectively,our study reveals a molecular mechanism by which a plant virus manipulates the Ros production system of host plants to facilitate viral infection and transmission,shedding new light on the sophisticated interactions among viruses,host plants,and insect vectors.

关键词： babarley yellow dwarf virus movement protein reactive oxygen species aphid catalase 26S proteasomeubiquitin receptor PSMD2

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The dynamics of traveling wavefronts for a model describing host tissue degradation by bacteria

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International Journal of Biomathematics 2024年第3期17卷 265-287页

作者： Xing-Xing Yang Guo-Bao Zhang Ge tian College of Mathematics and Statistics Northwest Normal University Lanzhou Gansu 730070P.R.China

In this paper,we mainly investigate the dynamics of traveling wavefronts for a model describing host tissue degradation by bacteria.We first establish the existence of spreading speed,and show that the spreading speed coincides with the minimal wave speed of traveling wavefronts.Moreover,a lower bound estimate of the spreading speed is given.Then,we prove that the traveling wavefronts with large speeds are globally exponentially stable,when the initial perturbation around the traveling wavefronts decays exponentially asχ→-∞,but the initial perturbation can be arbitrarily large in other locations.The adopted methods are the weighted energy and the squeezing technique.

关键词： Host tissue degradation bacterial infection traveling wavefronts minimal wave speed stability

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Spin effect on redox acceleration and regioselectivity in Fe-catalyzed alkyne hydrosilylation

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National Science Review 2024年第2期11卷 155-167页

作者： Peng He Meng-Yang Hu Jin-Hong Li tian-Zhang Qiao Yi-Lin Lu Shou-Fei Zhu Frontiers Science Center for New Organic Matter State Key Laboratory and Institute of Elemento-Organic Chemistry Nankai University

Iron catalysts are ideal transition metal catalysts because of the Earths abundant, cheap, biocompatible features of iron salts. Iron catalysts often have unique open-shell structures that easily undergo spin crossover in chemical transformations, a feature rarely found in noble metal catalysts. Unfortunately, little is known currently about how the open-shell structure and spin crossover affect the reactivity and selectivity of iron catalysts, which makes the development of iron catalysts a low efficient trial-and-error program. In this paper, a combination of experiments and theoretical calculations revealed that the iron-catalyzed hydrosilylation of alkynes is typical spin-crossover catalysis. Deep insight into the electronic structures of a set of well-defined open-shell active formal Fe(0) catalysts revealed that the spin-delocalization between the iron center and the 1,10-phenanthroline ligand effectively regulates the iron center's spin and oxidation state to meet the opposite electrostatic requirements of oxidative addition and reductive elimination, respectively,and the spin crossover is essential for this electron transfer process. The triplet transition state was essential for achieving high regioselectivity through tuning the nonbonding interactions. These findings provide an important reference for understanding the effect of catalyst spin state on reaction. It is inspiring for the development of iron catalysts and other Earth-abundant metal catalysts, especially from the point of view of ligand development.

关键词： spin effect spin-delocalization spin crossover iron-catalysis alkyne hydrosilylation

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迭代优化:做实做好课后服务质量提升

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中国基础教育 2023年第2期 51-55页

作者：田冰冰沈辽浙江省杭州市春晖小学教育集团浙江杭州311201

课后服务需要学校系统建构、整体推进。浙江省杭州市春晖小学教育集团西兴实验小学将课后服务课程化,在开足开齐课程的基础上主动选代,紧扣学生个性化发展需求,扩大课程供给,升级课程体系。学校在深入调查研究的基础上,扩大课程供给,组... 详细信息

课后服务需要学校系统建构、整体推进。浙江省杭州市春晖小学教育集团西兴实验小学将课后服务课程化,在开足开齐课程的基础上主动选代,紧扣学生个性化发展需求,扩大课程供给,升级课程体系。学校在深入调查研究的基础上,扩大课程供给,组建了六大类别课程群;实行精细管理,提升监管服务质量;利用数智平台,优化课后服务评价;分享研究成果,推动集团内各学校共同成长。

关键词： “双减”政策课后服务现场管理综合素质评价 “选课顾问”

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Silvestrol alleviates glioblastoma progression through ERK pathway modulation and MANBA and NRG-1 expression

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BIOCELL 2024年第7期48卷 1081-1093页

作者： LAN ZHOU QI ZHANG BO tian FENG YANG Neurosurgery Department The First Affiliated Hospital of Chongqing Medical and Pharmaceutical CollegeChongqingChina Neurosurgery Department Changdu People’s Hospital of TibetChangduChina

Background:Glioblastoma,a notably malignant tumor within the central nervous system,is distinguished by its aggressive behavior.Silvestrol,a robust inhibitor of the RNA helicase eukaryotic initiation factor 4A(eIF4A),has shown significant potential as an anticancer compound.Yet,the impact of silvestrol on glioblastoma,especially its molecular mechanisms,has not been fully elucidated.Methods:This investigation employed a variety of in vitro assays,such as cell counting kit-8(CCK-8),clonogenic,5-ethynyl-2′-deoxyuridine(EDU),wound healing,and flow cytometry,to evaluate cell cycle progression,apoptosis,cell viability,and migration.Western blot analysis was also performed to study the apoptosis and extracellular regulated kinase(ERK)pathways.After the ERK pathway was inhibited,differentially expressed genes(DEGs)in U87 cells were identified,followed by an analysis of target genes using the gene expression profiling interactive analysis(GEPIA)database.Results:Silvestrol significantly suppressed the proliferation,migration,and colony formation of glioma cells.It caused cell cycle arrest and enhanced apoptosis in these cells.Additionally,silvestrol stimulated the ERK pathway,with these effects being reversible by an ERK phosphorylation inhibitor.Transcriptome combined with GEPIA,GSCA,UALCAN,TIMER database screened 4 potential drug targets of silvestrol:chromosome 1 open reading frame 226(C1ORF226),mannosidase beta A(MANBA),IQ motif and Sec7 domain 2(IQSEC2),neuregulin 1(NRG-1).Among them,C1ORF226 was lower risk gene while MANBA,IQSEC2,and NRG-1 were high-risk genes.Furthermore,silvestrol notably reduced MANBA mRNA levels,which could be reversed by inhibiting ERK phosphorylation.Furthermore,silvestrol markedly decreased NRG-1 protein levels,with an additional reduction observed when the ERK pathway was blocked.Conclusion:Silvestrol’s anti-glioma effects are primarily due to the suppression of MANBA expression via the ERK pathway and possibly by hindering the translation of NRG-1 protein,thus reducing its expression.The do

关键词： Glioblastoma Silvestrol ERK pathway MANBA NRG-1

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Influence characteristics of water penetration on fibre-reinforced polymer/rigid polyurethane foam interface of the composite cross-arm considering natural ageing

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High Voltage 2024年第1期9卷 81-93页

作者： Jun Xie Zhe Zhou Ziqian Liu Haonan tian Sigang Zhang Qing Xie Hebei Provincial Key Laboratory of Power Transmission Equipment Security Defense North China Electric Power UniversityBaodingChina State Grid Gansu Electric Power Company LanzhouChina

Fibre-reinforced polymer(FRP)/rigid polyurethane foam(RPUF)interface is susceptible to moisture intrusion in addition to natural ageing during operation.This study investigated the influence of moisture intrusion on the FRP/RPUF interface under natural ageing using experiments and molecular dynamics(MD)simulations.Water absorption,shear strength,and leakage current tests were used to clarify the changes in the interface performance.The degradation mechanism of moisture intrusion at the interface under natural ageing was revealed by MD simulation and micro-characterisation.The results show that the natural ageing of interfacial materials will slightly reduce the quality of the interface but will reduce the water resistance of the material and promote the process of water intrusion into the interface.In addition,water mainly invades the interface through RPUF.After water penetration,the interfacial bonding strength and insulation performance significantly decreased.Plasticisation and hydrolysis of interfacial materials are the main reasons for decreased interfacial adhesion.Hydrolysis can cause irreversible damage to the interface,increasing interface defects and water absorption.The vicious cycle of material hydrolysis is the ultimate cause of interfacial debonding.The polar molecules produced by this process and the water absorbed by the interface caused the degradation of the interface insulation performance.

关键词： interface polyurethane interfacial

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Preface of the Special Issue on Symplectic Geometry and Mathematical Physics

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Acta Mathematica Sinica,English Series 2024年第1期40卷 1-2页

作者： Huijun Fan Xiaobo Liu Gang tian Peking University BeijingChina

Symplectic geometry is a branch of differential geometry and differential topology and has its origins in the Hamiltonian formulation of classical mechanics.In the last few decades,symplectic geometry has experienced enormous progress and has had interactions with many other branches of mathematics,including enumerative geometry,low-dimensional topology,mathematical physics,Hamiltonian dynamics,integrable systems etc..

关键词： geometry topology Hamiltonian

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Memory-enhanced text style transfer with dynamic style learning and calibration

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Science China(Information Sciences) 2024年第4期67卷 181-196页

作者： Fuqiang LIN Yiping SONG Zhiliang tian Wangqun CHEN Diwen DONG Bo LIU College of Computer Science and Technology National University of Defense Technology Department of Computer Science and Engineering The Hong Kong University of Science and Technology Strategic Assessments and Consultation Institute Academy of Military Sciences

Text style transfer aims to rephrase a sentence to match the desired style while retaining the original content. As a controllable text generation task, mainstream approaches use content-independent style embedding as control variables to guide stylistic generation. Nonetheless, stylistic properties are contextsensitive even under the same style. For example, “delicious” and “helpful” convey positive sentiments,although they are more likely to describe food and people, respectively. Therefore, desired style signals must vary with the content. To this end, we propose a memory-enhanced transfer method, which learns fine-grained style representation concerning content to assist transfer. Rather than employing static style embedding or latent variables, our method abstracts linguistic characteristics from training corpora and memorizes subdivided content with the corresponding style representations. The style signal is dynamically retrieved from memory using the content as a query, providing a more expressive and flexible latent style space. To address the imbalance between quantity and quality in different content, we further introduce a calibration method to augment memory construction by modeling the relationship between candidate styles.Experimental results obtained using three benchmark datasets confirm the superior performance of our model compared to competitive approaches. The evaluation metrics and case study also indicate that our model can generate diverse stylistic phrases matching context.

关键词： style transfer memory-enhanced method text generation deep learning text representation

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Resonant Beam Communications:A New Design Paradigm and Challenges

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Journal of Communications and Information Networks 2024年第1期9卷 80-87页

作者： Yuanming tian Dongxu Li Chuan Huang Qingwen Liu Shengli Zhou Future Network of Intelligence Institute and School of Science and Engineering the Chinese University of Hong KongShenzhen 518172China School of Science and Engineering and the Future Network of Intelligence Institute the Chinese University of Hong KongShenzhen 518172China College of Electronics and Information Engineering Tongji UniversityShanghai 201804China Department of Electrical and Computer Engineering University of ConnecticutStorrsCT 06250USA

Resonant beam communications (RBCom), which adopts oscillating photons between two separate retroreflectors for information transmission, exhibits potential advantages over other types of wireless optical communications (WOC). However, echo interference generated by the modulated beam reflected from the receiver affects the transmission of the desired information. To tackle this challenge, a synchronization-based point-to-point RBCom system is proposed to eliminate the echo interference, and the design for the transmitter and receiver is discussed. Subsequently,the performance of the proposed RBCom is evaluated and compared with that of visible light communications(VLC)and free space optical communications (FOC). Finally, future research directions are outlined and several implementation challenges of RBCom systems are highlighted.

关键词： resonant beam communications(RBCom) wireless optical communications(WOC) echo interference elimination mobility multiple access

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