检索结果-南通市图书馆

One-dimensional chain of quantum molecule motors as a mathematical physics model for muscle fibers

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2015年第12期24卷 119-137页

作者：司铁岩 Academy of Fundamental and Interdisciplinary Sciences Harbin Institute of Technology max-planck-Institute for the Physics of Complex Systems

A quantum chain model of multiple molecule motors is proposed as a mathematical physics theory for the microscopic modeling of classical force-velocity relation and tension transients in muscle fibers. The proposed model was a quantum many-particle Hamiltonian to predict the force-velocity relation for the slow release of muscle fibers, which has not yet been empirically defined and was much more complicated than the hyperbolic relationships. Using the same Hamiltonian model, a mathematical force-velocity relationship was proposed to explain the tension observed when the muscle was stimulated with an alternative electric current. The discrepancy between input electric frequency and the muscle oscillation frequency could be explained physically by the Doppler effect in this quantum chain model. Further more, quantum physics phenomena were applied to explore the tension time course of cardiac muscle and insect flight muscle. Most of the experimental tension transient curves were found to correspond to the theoretical output of quantum two- and three-level models. Mathematical modeling electric stimulus as photons exciting a quantum three-level particle reproduced most of the tension transient curves of water bug Lethocerus maximus.

关键词： physics model of muscles fibers cooperative molecule motors force-velocity relationship quantum chain model

SALT-RESPONSIVE ERF1 Is a Negative Regulatorof Grain Filling and Gibberellin-MediatedSeedling Establishment in Rice

在线全文

学校读者我要写书评

暂无评论

Molecular Plant 2014年第2期7卷 404-421页

作者： Romy Schmidt Jos H. M. Schippers Delphine Mieulet Institute of Biochemistry and Biology University of Potsdam max planck Institute of Molecular Plant Physiology

Grain quality is an important agricultural trait that is mainly determined by grain size and ***, we characterize the role of the rice transcription factor （TF） SALT-RESPONSIVE ERF1 （SERF1） during grain develop-ment. Through genome-wide expression profiling and chromatin immunoprecipitation, we found that SERF1 directlyregulates RICE PROLAMIN-BOX BINDING FACTOR （RPBF）, a TF that functions as a positive regulator of grain filling. Lossof SERF1 enhances RPBF expression resulting in larger grains with increased starch content, while SERF1 overexpressionrepresses RPBF resulting in smaller grains. Consistently, during grain filling, starch biosynthesis genes such as GRANULE-BOUND STARCH SYNTHASEI （GBSSI）, STARCH SYNTHASEI （SSI）, SSIIla, and ADP-GLUCOSE PYROPHOSPHORYLASELARGE SUBUNIT2 （AGPL2） are up-regulated in SERF1 knockout grains. Moreover, SERF1 is a direct upstream regulator ofGBSSI. In addition, SERF1 negatively regulates germination by controlling RPBF expression, which mediates the gibberel-lic acid （GA）-induced expression of RICE AMYLASEIA （RAmylA）. Loss of SERF1 results in more rapid seedling establish-ment, while SERF1 overexpression has the opposite effect. Our study reveals that SERF1 represents a negative regulatorof grain filling and seedling establishment by timing the expression of RPBF.

关键词： RPBF rice grain filling germination SERF1 gibberellic acid

The RNA binding protein EHD6 recruits the m^(6)A reader YTH07 and sequesters OsCOL4 mRNA into phase-separated ribonucleoprotein condensates to promote rice flowering

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2024年第6期17卷 935-954页

作者： Song Cui Peizhe Song Chaolong Wang Saihua Chen Benyuan Hao Zhuang Xu Liang Cai Xu Chen Shanshan Zhu Xiangchao Gan Hui Dong Yuan Hu Liang Zhou Haigang Hou Yunlu Tian Xi Liu Liangming Chen Shijia Liu Ling Jiang Haiyang Wang Guifang Jia Shirong Zhou Jianmin Wan State Key Laboratory for Crop Genetics&Germplasm Enhancement and Utilization Zhongshan Biological Breeding LaboratoryNational Observation and Research Station of Rice Germplasm ResourcesNanjing Agricultural UniversityNanjing 210095China State Key Laboratory for Crop Gene Resources and Breeding Institute of Crop ScienceChinese Academy of Agricultural SciencesBeijing 100081China Synthetic and Functional Biomolecules Center Beijing National Laboratory for Molecular SciencesKey Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking-Tsinghua Center for Life SciencesBeijing Advanced Center of RNA BiologyPeking UniversityBeijingChina Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding Agricultural College of Yangzhou UniversityYangzhou 225009China max planck Institute for Plant Breeding Research Carl-von-Linne´-Weg 1050829 KolnGermany

N6-Methyladenosine(m^(6)A)is one of the most abundant modifications of eukaryotic mRNA,but its comprehensive biological functionality remains further *** this study,we identified and characterized a new flowering-promoting gene,EARLY HEADING DATE6(EHD6),in ***6 encodes an RNA recognition motif(RRM)-containing RNA binding protein that is localized in the non-membranous cytoplasm ribonucleoprotein(RNP)granules and can bind both m^(6)A-modified RNA and unmodified RNA *** found that EHD6 can physically interact with YTH07,a YTH(YT521-B homology)domain-containing m^(6)A *** showed that their interaction enhances the binding of an m^(6)A-modified RNA and triggers relocation of a portion of YTH07 from the cytoplasm into RNP granules through phase-separated *** these condensates,the mRNA of a rice flowering repressor,CONSTANS-like 4(OsCOL4),becomes sequestered,leading to a reduction in its protein abundance and thus accelerated flowering through the Early heading date 1 *** together,these results not only shed new light on the molecular mechanism of efficient m^(6)A recognition by the collaboration between an RNA binding protein and YTH family m^(6)A reader,but also uncover the potential for m^(6)A-mediated translation regulation through phaseseparated ribonucleoprotein condensation in rice.

关键词： N6-methyladenosine m^(6)A EHD6 YTH domain-containing protein phase separation heading date

Lightning in a Forest (Wild) Fire: Mechanism at the Molecular Level

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Atmospheric and Climate Sciences 2024年第1期14卷 128-135页

作者： See Leang Chin Xueliang Guo Harmut Schroeder Huanbin Xu Tie-Jun Wang Ruxin Li Weiwei Liu Department of Physics and Center for Optics Photonics and Lasers (COPL) Laval University Quebec Canada Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China max planck Institute of Quantum Optics Garching Germany State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai China Institute of Modern Optics Nankai University Tianjin China

The mechanism of lightning that ignites a forest fire and the lightning that occurs above a forest fire are explained at the molecular level. It is based on two phenomena, namely, internal charge separation inside the atmospheric cloud particles and the existence of a layer of positively charged hydrogen atoms sticking out of the surface of the liquid layer of water on the surface of rimers. Strong turbulence-driven collisions of the ice particles and water droplets with the rimers give rise to breakups of the ice particles and water droplets into positively and negatively charged fragments leading to charge separation. Hot weather in a forest contributes to the updraft of hot and humid air, which follows the same physical/chemical processes of normal lightning proposed and explained recently[1]. Lightning would have a high probability of lighting up and burning the dry biological materials in the ground of the forest, leading to a forest (wild) fire. The burning of trees and other plants would release a lot of heat and moisture together with a lot of smoke particles (aerosols) becoming a strong updraft. The condition for creating lightning is again satisfied which would result in further lightning high above the forest wild fire.

关键词： Forest Wild Fire Lightning Molecular Level

A Coupled Model Study on the Intensification of the Asian Summer Monsoon in IPCC SRES Scenarios

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2005年第6期22卷 798-806页

作者： Min WEI max-planck-Institut fur Meteorologie Bundesstrasse 53 D-20146 Hamburg Germany

The Asian summer monsoon is an important part of the climate system. Investigating the response of the Asian summer monsoon to changing concentrations of greenhouse gases and aerosols will be meaningful to understand and predict climate variability and climate change not only in Asia but also globally. In order to diagnose the impacts of future anthropogenic emissions on monsoon climates, a coupled general circulation model of the atmosphere and the ocean has been used at the max-planck-Institute for Meteorology. In addition to carbon dioxide, the major well mixed greenhouse gases such as methane, nitrous oxide, several chlorofluorocarbons, and CFC substitute gases are prescribed as a function of time. The sulfur cycle is simulated interactively, and both the direct aerosol effect and the indirect cloud albedo effect are considered. Furthermore, changes in tropospheric ozone have been pre-calculated with a chemical transport model and prescribed as a function of time and space in the climate simulations. Concentrations of greenhouse gases and anthropogenic emissions of sulfur dioxide are prescribed according to observations （1860-1990） and projected into the future （1990-2100） according to the Scenarios A2 and B2 in Special Report on Emissions Scenarios （SRES, Nakcenovic et al., 2000） developed by the Intergovernmental Panel on Climate Change （IPCC）. It is found that the Indian summer monsoon is enhanced in the scenarios in terms of both mean precipitation and interannual variability. An increase in precipitation is simulated for northern China but a decrease for the southern part. Furthermore, the simulated future increase in monsoon variability seems to be linked to enhanced ENSO variability towards the end of the scenario integrations.

关键词： asian summer monsoon climate change IPCC SRES scenarios

Assemblies and composites of gold nanostructures for functional devices

在线全文

学校读者我要写书评

暂无评论

Aggregate

Aggregate 2022年第4期3卷 4-14页

作者： Ke He Ying Jiang Ting Wang Zhihua Liu Ming Wang Liang Pan Xiaodong Chen Innovative centre for Flexible Devices(iFLEX) Max Planck–NTU Joint Lab for Artificial SensesSchool of Materials Science and EngineeringNanyang Technological UniversitySingapore

Gold has been one of the most vastly used noble metals due to its unique *** modern manufacturing,gold is extensively used in electronics industry as electrical connectors due to the high conductivity and corrosion *** advancements in gold chemistry and nanofabrication technologies,gold materials can be tailored down to the dimension of nanoscale,which enables various novel ***,it is still a huge challenge to realize practical functional devices by rational utilizing these gold nanostructures-based ***,the recent developments in the design and fabrication of various functional devices based on assemblies and composites of gold nanostructures are *** from the plasmonic effect,optical colorimetric sensors,optoelectronics and surface-enhanced Raman spectroscopy sensors are *** by conductive devices with novel properties,flexible transparent conductors,stretchable electronics,wearable and implantable devices are *** bottom-up and top-down approaches to prepare assemblies and composites are *** addition,the challenges and future developments in the field are also *** is believed that further developments in gold nanostructures-based materials will greatly contribute to the nextgeneration biosensors,optoelectronics,wearable and implantable electronics.

关键词： assemblies composites functional devices gold materials nanostructures

Comparison of edge cracking and tensile cracking in in-situ deformation at 150℃of Mg-2Zn-1.5Mn alloy sheet

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第17期112卷 24-35页

作者： Qiang Liu Jiangfeng Song Yuanding Huang Bin Jiang Biquan Xiao Fusheng Pan National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China MagIC-Magnesium innovation centre Helmholtz-Zentrum GeesthachtMax-Planck-Str.121502 GeesthachtGermany

The Mg-2Zn-1.5Mn alloy(ZM21)sheets were hot-rolled in a single pass at 150℃with different reductions through on-line heating *** and edge cracking behavior of the rolled sheets were *** in-situ tensile tests at 150℃were also carried out,the crack initiation and propagation were compared with the edge cracking behavior of ZM21 sheets prepared by on-line heating *** results reveal that the edge cracks are most likely to originate in the rolling direction and normal direction(RD-ND)plane due to the secondary tensile stress along *** cracking becomes more severe with an increasing *** edge cracks mainly initiate and propagate in the fine recrystallized grain areas and the junction of recrystallized grains and sub-grains with hard *** in-situ tensile test indicates that micro-cracks mainly initiate at the triple junction of grain boundaries where grains have hard orientation with low basal Schmid factor(SF).Meanwhile,those cracks are more likely to propagate along the grain boundaries with maximum difference in basal Schmid ***,the crack initiation and propagation during the in-situ tensile deformation at 150℃are found not to be associated with the recrystallization.

关键词： ZM21 Mg alloy On-line heating rolling In-situ tensile test Edge crack

Cytokinin levels and signaling respond to wounding and the perception of herbivore elicitors in Nicotiana attenuata

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2015年第2期57卷 198-212页

作者： Martin Sch?fer Ivan D. Meza-Canales Aura Navarro-Quezada Christoph Brütting Radomira Vanková Ian T. Baldwin Stefan Meldau Department of Molecular Ecology Max Planck Institute for Chemical Ecology Laboratory of Hormonal Regulations in Plants Institute of Experimental Botany AS CR German centre for integrative Biodiversity Research (i Div)

Nearly half a century ago insect herbivores were found to induce the formation of green islands by manipulating cytokinin （CK） levels. However, the response of the CK pathway to attack by chewing insect herbivores remains unclear. Here, we characterize the CK pathway of Nicotiana attenuata （Torr. ex S. Wats.） and its response to wounding and perception of herbivoreassociated molecular patterns （HAMPs）. We identified 44 genes involved in CK biosynthesis, inactivation, degradation, and signaling. Leaf wounding rapidly induced transcriptional changes in multiple genes throughout the pathway, as well as in the levels of CKs, including isopentenyladenosine and cis-zeatin riboside; perception of HAMPs present in the oral secretions （OS） of the specialist herbivore Manduca sexta amplified these responses. The jasmonate pathway, which triggers many herbivore-induced processes, was not required for these HAMP-triggered changes, but rather suppressed the CK responses. Interestingly CK pathway changes were observed also in systemic leaves in response to wounding and OS application indicating a role of CKs in mediating long distance systemic processes in response to herbivory. Since wounding and grasshopper OS elicited similar accumulations of CKs in Arabidopsis thaliana L., we propose that CKs are integral components of wounding and HAMP-triggered responses in many plant species.

关键词： Arabidopsis thaliana cytokinin herbivore-associated molecular patterns herbivory insect jasmonic acid Manduca sexta Nicotiana attenuata wounding

Quo vadis carbocatalysis?

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2021年第10期30卷 219-227,I0007页

作者： Robert Schlögl max-planck-Institut für Chemische Energiekonversion Stiftstr.34-3645470 Mülheim an der RuhrGermany Fritz-Haber Institut der max-planck-Gesellschaft Faradayweg 4-614195 BerlinGermany

Prologue The rich scientific heritage of Dangsheng Su contains as substantial fraction his contributions to the field of catalysis with nanostructured carbon *** from microstructural analysis it became quickly clear that the richness of morphological and hence surface electronic variations in this class of materials should be suitable for the development of a science base for heterogeneous catalysis.

关键词： materials. catalysis. catalysis