期刊文献+
共找到1,037篇文章
< 1 2 52 >
每页显示 20 50 100
Ingenious liquid-observed vapor exchange (LOVE) NMR method revealing how sugars protect dry protein structure
1
作者 Geying Ru Conggang Li 《Magnetic Resonance Letters》 2024年第2期75-76,共2页
Recently,Gary et al.published an article elucidating how sugars contribute to the protection of dry protein structure.They utilized an ingenious liquid-observed vapor exchange(LOVE)nuclear magnetic resonance(NMR)metho... Recently,Gary et al.published an article elucidating how sugars contribute to the protection of dry protein structure.They utilized an ingenious liquid-observed vapor exchange(LOVE)nuclear magnetic resonance(NMR)method,providing valuable insights into the protection mechanism of sugars during the drying process.The details of their study can be found in the article available at https://doi.org/10.1021/acs.biochem.2c00692. 展开更多
关键词 structure SUGAR revealING
下载PDF
Revealed comparative advantage and competitiveness of China’s agricultural products 被引量:2
2
作者 詹晶 《Agricultural Science & Technology》 CAS 2005年第1期10-13,共4页
This paper deals with the competitiveness of Chinese agricultural products, base on the index of revealed comparative advantage (RCA) using lots of data for the period of 1980 to 2003. The index is useful in identifyi... This paper deals with the competitiveness of Chinese agricultural products, base on the index of revealed comparative advantage (RCA) using lots of data for the period of 1980 to 2003. The index is useful in identifying the demarcation between comparative advantage and comparative disadvantage. The research indicates that some agro-products in China such as edible vegetables and tea have a comparative advantage, but the RCA values have been declining over the 24-year period, which has vast impacts on future reform in China’s agricultural structure. 展开更多
关键词 agricultural product EXPORT revealed comparative advantage (RCA) competitiveness.
下载PDF
Exercise-induced irisin in bone and systemic irisin administration reveal new regulatory mechanisms of bone metabolism 被引量:26
3
作者 Jin Zhang Paloma Valverde +9 位作者 Xiaofang Zhu Dana Murray Yuwei Wu Liming Yu Hua Jiang Michel M Dard Jin Huang Zhiwei Xu Qisheng Tu Jake Chen 《Bone Research》 SCIE CAS CSCD 2017年第1期49-62,共14页
Irisin is a polypeptide hormone derived from the proteolytic cleavage of fibronectin-type III domain- containing 5 (FNDC5) protein. Once released to circulation upon exercise or cold exposure, irisin stimulates brow... Irisin is a polypeptide hormone derived from the proteolytic cleavage of fibronectin-type III domain- containing 5 (FNDC5) protein. Once released to circulation upon exercise or cold exposure, irisin stimulates browning of white adipose tissue (WAT) and uncoupling protein I (UCP1) expression, leading to an increase in total body energy expenditure by augmented UCPl-mediated thermogenesis. It is currently unknown whether irisin is secreted by bone upon exercise or whether it regulates bone metabolism in vivo. In this study, we found that 2 weeks of voluntary wheel-running exercise induced high levels of FNDC5 messenger RNA as well as FNDC5/irisin protein expression in murine bone tissues. Increased immunoreactivity due to exercise-induced FNDC5/irisin expression was detected in different regions of exercised femoral bones, including growth plate, trabecular bone, cortical bone, articular cartilage, and bone-tendon interface. Exercise also increased expression of osteogenic markers in bone and that of UCP1 in WAT, and led to bodyweight loss. Irisin intraperitoneal (IP) administration resulted in increased trabecular and cortical bone thickness and osteoblasts numbers, and concurrently induced UCP1 expression in subcutaneous WAT. Lentiviral FNDC5 IP administration increased cortical bone thickness. In vitro studies in bone cells revealed irisin increases osteoblastogenesis and mineralization, and inhibits receptor activator of nuclear factor-kB ligand (RANKL)- induced osteoclastogenesis. Taken together, our findings show that voluntary exercise increases irisin production in bone, and that an increase in circulating irisin levels enhances osteogenesis in mice. 展开更多
关键词 Exercise-induced irisin in bone and systemic irisin administration reveal new regulatory mechanisms of bone metabolism BONE
下载PDF
Comparative Genomic Analysis of Enterovirus 71 Revealed Six New Potential Neurovirulence-associated Sites 被引量:6
4
作者 JIA Qing Jun CHEN Xin Yu +4 位作者 LI De Zhou XU Juan Juan XU Zhi Gang DUAN Zhi Liang WEN Jin Sheng 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2016年第10期767-772,共6页
In the present study,the complete genomes of four common(4/EV71/Wenzhou/CHN/2014,15/EV71/Wenzhou/CHN/2014,116/EV71/Wenzhou/CHN/2014,and 120/EV71/Wenzhou/CHN/2014)and two virulent(11/EV71/Wenzhou/CHN/2014and 109/EV7... In the present study,the complete genomes of four common(4/EV71/Wenzhou/CHN/2014,15/EV71/Wenzhou/CHN/2014,116/EV71/Wenzhou/CHN/2014,and 120/EV71/Wenzhou/CHN/2014)and two virulent(11/EV71/Wenzhou/CHN/2014and 109/EV71/Wenzhou/CHN/2014)enterovirus 71(EV71)isolates were sequenced and described.They are 7405 bp in length and belong to EV71 sub-genotype C4 (C4a cluster). 展开更多
关键词 CHN UTR EV Comparative Genomic Analysis of Enterovirus 71 revealed Six New Potential Neurovirulence-associated Sites
下载PDF
Angiography reveals early hiding iris neovascularization after ischemic CRVO 被引量:4
5
作者 Zhi-Qing Li Xiao-Xu Zhou +2 位作者 Song Lin Jun-Ling Li Jian-Guo Wu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2013年第2期253-254,共2页
Dear Sir, I am Dr. Zhi-Qing Li from Tianjin Medical University Eye Hospital, Tianjin City, China. I write to present a case with hiding iris neovascularization (INV) following central retinal vein occlusion (CRVO) can... Dear Sir, I am Dr. Zhi-Qing Li from Tianjin Medical University Eye Hospital, Tianjin City, China. I write to present a case with hiding iris neovascularization (INV) following central retinal vein occlusion (CRVO) can be detected early by iris angiography (IA) and neovascular glaucoma (NVG) was 展开更多
关键词 Angiography reveals early hiding iris neovascularization after ischemic CRVO INV IA NVG Figure
下载PDF
Unintended targeting of Dmp1-Cre reveals a critical role for Bmpr1a signaling in the gastrointestinal mesenchyme of adult mice 被引量:5
6
作者 Joohyun Lim Joseph Burclaff +2 位作者 Guangxu He Jason C Mills Fanxin Long 《Bone Research》 SCIE CAS CSCD 2017年第1期41-48,共8页
Cre/loxP technology has been widely used to study cell type-specific functions of genes. Proper interpretation of such data critically depends on a clear understanding of the tissue specificity of Cre expression. The ... Cre/loxP technology has been widely used to study cell type-specific functions of genes. Proper interpretation of such data critically depends on a clear understanding of the tissue specificity of Cre expression. The Dmpl- Cre mouse, expressing Cre from a 14-kb DNA fragment of the mouse Dmpl gene, has become a common tool for studying gene function in osteocytes, but the presumed cell specificity is yet to be fully established. By using the Ai9 reporter line that expresses a red fluorescent protein upon Cre recombination, we find that in 2-month-old mice, Dmpl-Cre targets not only osteocytes within the bone matrix but also osteoblasts on the bone surface and preosteoblasts at the metaphyseal chondro-osseous junction. In the bone marrow, Cre activity is evident in certain stromal cells adjacent to the blood vessels, but not in adipocytes. Outside the skeleton, Dmpl-Cre marks not only the skeletal muscle fibers, certain cells in the cerebellum and the hindbrain but also gastric and intestinal mesenchymal cells that express Pdgfra. Confirming the utility of Dmpl-Cre in the gastrointestinal mesenchyme, deletion of Bmprla with Dmpl-Cre causes numerous large polyps along the gastrointestinal tract, consistent with prior work involving inhibition of BMP signaling. Thus, caution needs to be exercised when using Dmpl-Cre because it targets not only the osteoblast lineage at an earlier stage than previously appreciated, but also a number of non-skeletal cell types. 展开更多
关键词 gene cell bone Unintended targeting of Dmp1-Cre reveals a critical role for Bmpr1a signaling in the gastrointestinal mesenchyme of adult mice Figure
下载PDF
Mutagenesis reveals that the rice OsMPT3 gene is an important osmotic regulatory factor 被引量:2
7
作者 Shengcai Huang Shichao Xin +6 位作者 Guoqiang Xie Jiao Han Zhonglai Liu Bing Wang Shuqing Zhang Qingyu Wu Xianguo Cheng 《The Crop Journal》 SCIE CAS CSCD 2020年第3期465-479,共15页
Plant mitochondrial phosphate transporters regulate phosphate transport and ATP synthesis. Determining whether they function in abiotic stress response process would shed light on their response to salt stress. We use... Plant mitochondrial phosphate transporters regulate phosphate transport and ATP synthesis. Determining whether they function in abiotic stress response process would shed light on their response to salt stress. We used the CRISPR/Cas9 gene-editing system to mutagenize two mitochondrial phosphate transporters, OsMPT3;1 and OsMPT3;2, to investigate their regulatory roles under salt stress. Two cas9(CRISPR-associated protein9)-free homozygous mutants, mpt33 and mpt30, were confirmed to be stable. Both OsMPT3;1 and OsMPT3;2 were markedly induced by salt stress, and their mutagenesis strongly inhibited growth and development, especially under salt stress. Mutagenesis sharply reduced the accumulation of ATP, phosphate, calcium, soluble sugar, and proline and increased osmotic potential, malondialdehyde, and Na^+ /K^+ ratio under salt stress. Both mutants demonstrate normal growth and development in the presence of ATP, revealing high sensitivity to exogenous ATP under salt stress. The mutants showed lowered rates of Na^+ efflux but also of K^+ and Ca^(2+) influx under salt stress. Mutagenesis of OsMPT3;2 altered the enrichment profiles of differentially expressed genes involved mainly in synthesis of secondary metabolites, metabolism of glycolysis, pyruvate, tricarboxylic acid cycle, in response to salt stress. The mutant displayed significant accumulation differences in 14 metabolites involved in 17 metabolic pathways, and strongly up-regulated the accumulation of glutamine, a precursor in proline synthesis, under salt stress. These findings suggest that the OsMPT3 gene modulates phosphate transport and energy supply for ATP synthesis and triggers changes in accumulation of ions and metabolites participating in osmotic regulation in rice under salt stress, thus increasing rice salt tolerance. This study demonstrates the effective application of CRISPR/Cas9 gene-editing to the investigation of plant functional genes. 展开更多
关键词 MPT ATP CRISPR Mutagenesis reveals that the rice OsMPT3 gene is an important osmotic regulatory factor
下载PDF
Possible Nodeless Superconducting Gaps in Bi_2Sr_2CaCu_2O_(8+δ) and YBa_2Cu_3O_(7-x) Revealed by Cross-Sectional Scanning Tunneling Spectroscopy 被引量:2
8
作者 任明强 闫亚军 +1 位作者 张童 封东来 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第12期124-128,共5页
Pairing in the cuprate high-temperature superconductors and its origin remain among the most enduring mysteries in condensed matter physics. With cross-sectional scanning tunneling microscopy/spectroscopy, we clearly ... Pairing in the cuprate high-temperature superconductors and its origin remain among the most enduring mysteries in condensed matter physics. With cross-sectional scanning tunneling microscopy/spectroscopy, we clearly reveal the spatial-dependence or inhomogeneity of the superconducting gap structure of Bi2Sr2CaCu2O8+δ (Bi2212) and YBa2Cu3O7-x (YBCO) along their c-axes on a scale shorter than the interlayer spacing. By tunneling into the (100) plane of a Bi2212 single crystal and a YBCO film, we observe both U-shaped tunneling spectra with extended fiat zero-conductance bottoms, and V-shaped gap structures, in different regions of each sample. On the YBCO film, tunneling into a (110) surface only reveals a U-shaped gap without any zero-bias peak. Our analysis suggests that the U-shaped gap is likely a nodeless superconducting gap. The V-shaped gap has a very small amplitude, and is likely proximity-induced by regions having the larger U-shaped gap. 展开更多
关键词 of is in revealed by Cross-Sectional Scanning Tunneling Spectroscopy and YBa2Cu3O Possible Nodeless Superconducting Gaps in Bi2Sr2CaCu2O by DOS on BI Cu Sr
下载PDF
Stem cells in the adult CNS revealed:examining their regulation by myelin basic protein 被引量:1
9
作者 Wenjun Xu Nishanth Lakshman Cindi M.Morshead 《Neural Regeneration Research》 SCIE CAS CSCD 2016年第12期1916-1917,共2页
Neural stem cells(NSCs)are found along the entire neuraxis,through development and into adulthood and old age(Sachewsky et al.,2014;Xu et al.,2016).There are two neurogenic niches in the adult CNS.One is the subgr... Neural stem cells(NSCs)are found along the entire neuraxis,through development and into adulthood and old age(Sachewsky et al.,2014;Xu et al.,2016).There are two neurogenic niches in the adult CNS.One is the subgranular zone in the hippocampus and the other is found in the periventricular region throughout the extent of the neuraxis(Barnabé-Heider et al.,2010;Mirzadeh et al.,2010). 展开更多
关键词 NSCS cell Stem cells in the adult CNS revealed CNS
下载PDF
Common Electronic Features and Electronic Nematicity in Parent Compounds of Iron-Based Superconductors and FeSe/SrTiO_3 Films Revealed by Angle-Resolved Photoemission Spectroscopy 被引量:1
10
作者 刘德发 赵林 +22 位作者 何少龙 胡勇 沈兵 黄建伟 梁爱基 徐煜 刘旭 何俊峰 牟代翔 刘单于 刘海云 刘国东 张文号 李坊森 马旭村 薛其坤 陈仙辉 陈根富 俞理 张君 许祖彦 陈创天 周兴江 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第7期152-156,共5页
We report comprehensive angle-resolved photoemission investigations on the electronic structures and nematicity of the parent compounds of the iron-based superconductors including CeFeAsO, BaFe2As2, NaFeAs, FeSe and u... We report comprehensive angle-resolved photoemission investigations on the electronic structures and nematicity of the parent compounds of the iron-based superconductors including CeFeAsO, BaFe2As2, NaFeAs, FeSe and undoped FeSe/SrTiO3 films with 1, 2 and 20 layers. While the electronic structure near tile Brillouin zone center F varies dramatically among different materials, the electronic structure near the Brillouin zone corners (M points), as well as their temperature dependence, are rather similar. The electronic structure near the zone corners is dominated by the electronic nematicity that gives rise to a band splitting of the dxz and dyz bands below the nematie transition temperature. A clear relation is observed between the band splitting magnitude arid the onset temperature of nematicity. Our results may shed light on the origin of nematicity, its effect on the electronic structures, and its relation with superconductivity in the iron-based superconductors. 展开更多
关键词 of on as or by Common Electronic Features and Electronic Nematicity in Parent Compounds of Iron-Based Superconductors and FeSe/SrTiO3 Films revealed by Angle-Resolved Photoemission Spectroscopy in ARPES As that
下载PDF
Revealing the Landform Types and Morphologic Features of Lunar Surface 被引量:1
11
作者 CHENG Weiming 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第4期1517-1518,共2页
A lunar geologic map at a scale of 1:5000000 was finished in the 1970s by the National Aeronautics and Space Administration, U.S U.S. Geological Survey. Department of the Interior, Till now, the landform classificati... A lunar geologic map at a scale of 1:5000000 was finished in the 1970s by the National Aeronautics and Space Administration, U.S U.S. Geological Survey. Department of the Interior, Till now, the landform classification system and lunar morphologic mapping have not been clarified. The work aims to put forward a new landform classification system and to obtain index and map in the Sheet H010. Some key morphologic features of lunar surface were compared with those of the Earth. This research is very important for whole lunar morphologic mapping and unraveling evolutionary progress. 展开更多
关键词 THAN revealing the Landform Types and Morphologic Features of Lunar Surface
下载PDF
On Mars, Location and Orientation of Dykes Exposed along the Valles Marineris Walls Reveal Expected and Unexpected Stress Fields 被引量:1
12
作者 Daniel MèGE Joanna GURGUREWICZ 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第S1期177-179,共3页
Structural and geomorphological analysis of the Martian surface in the visible spectral range using the NASA/Viking images in the 90’s,complemented by experimental modelling(Mège and Masson,1996a;Mège et al... Structural and geomorphological analysis of the Martian surface in the visible spectral range using the NASA/Viking images in the 90’s,complemented by experimental modelling(Mège and Masson,1996a;Mège et al.,2003)suggested that the Valles Marineris trough(chasma)system is aligned with a mafic dyke swarm,named the Syria Planum Dyke Swarm.Cross-cutting relationships and 展开更多
关键词 On Mars Location and Orientation of Dykes Exposed along the Valles Marineris Walls reveal Expected and Unexpected Stress Fields Figure
下载PDF
Differential Proteomics Reveals the Potential Injury Mechanism Induced by Heavy Ion Radiation in Mice Ovaries 被引量:1
13
作者 HE Yu Xuan ZHANG Hong +4 位作者 LI Hong Yan ZHANG Yong JIA Qi Peng LI Zong Shuai ZHAO Xing Xu 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2017年第4期301-307,共7页
In the present study, we used a proteomics approach based on a two-dimensional electrophoresis (2-DE) reference map to investigate protein expression in the ovarian tissues of pubertal Swiss-Webster mice subjected t... In the present study, we used a proteomics approach based on a two-dimensional electrophoresis (2-DE) reference map to investigate protein expression in the ovarian tissues of pubertal Swiss-Webster mice subjected to carbon ion radiation (CIR). Among the identified proteins, ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) is associated with the cell cycle[1] and that it influences proliferation in ovarian tissues. We analyzed the expression of UCH-L1 and the proliferation marker proliferation cell nuclear antigen (PCNA) following CIR using immunoblotting and immunofluorescence. The proteomics and biochemical results provide insight into the underlying mechanisms of CIR toxicity in ovarian tissues. 展开更多
关键词 Differential Proteomics reveals the Potential Injury Mechanism Induced by Heavy Ion Radiation in Mice Ovaries Figure
下载PDF
Force Spectrum of Single CsgA Nanofiber Reveal Surprising Properties
14
作者 Jingqi Lv Yingfeng Li +7 位作者 Kai Zhou Pei Guo Ke Ding Quan Long Yang Liu Qi Wang Chao Zhong Botao Xiao 《医用生物力学》 EI CAS CSCD 北大核心 2019年第A01期181-181,共1页
CsgA protein monomers consist of aβ-helix of five repeat units possessing several conservative residues and thus,inherently fibrillate.CsgA protein monomers could self-assemble into hierarchical nanofiber structure c... CsgA protein monomers consist of aβ-helix of five repeat units possessing several conservative residues and thus,inherently fibrillate.CsgA protein monomers could self-assemble into hierarchical nanofiber structure cross multiple scales after expression and secretion by E.Coli cells.Previous researches show that CsgA nanofibers could provide adhesion,stiffness,and mechanical homogeneity for the biofilms,host cells’fibronectin binding for internalization,or protection against phage attack.CsgA nanofibers have obtained various applications in material science and synthetic biology.To illustrate,CsgA nanofibers have characteristics of intrinsic hierarchical structures across multiple scales,robustness in harsh environments and programmable functionality via biological tools.Studying the force spectrum or mechanical properties of the nanofiber can provide fundamental information of self-assembly process and ultra-stability in extreme conditions.Single molecule techniques such as atomic force microscopy,optical tweezers,and magnetic tweezers have been widely applied to study proteins.In these studies,proteins are usually chemically conjugated or genetically constructed to have a tag such as histidine,cysteine or biotin.Genetic engineering requires modification of the plasmids encoding the specific protein,and also involve special protein expression and purification.Such study needs collaboration from multi-disciplinary.It normally studies one protein at a time which gives out clear signal but lacks throughput and efficiency.Here we have established a simple method to measure all kinds of proteins without labels.The carboxyl terminus of a protein is attached to the amine group on a magnetic bead,and the amine terminus of the protein is attached to glutaraldehyde on the glass slide.Then we used magnetic tweezers to manipulate and stretched the bead and protein.Extension versus rotation relation was used to identify a single protein or protein fibril.The fiber under tension is also observed by Scanning Electronic Microcopy which convinces that single CsgA-His fibril is linked to a microbead.The peak of diameter distribution is around 15 nm.The fracture of fibers was observed in real time on SEM.Force-extension curves of single fibers are obtained in real time.The force-extension curves generally agree with the worm like chain model.The persistence lengths from the fitting are from 0.9 to 49.8 nm.The elongation ratio increases gradually with force until reaches a plateau.The maximum elongation ratio of 78 nanofibers were made into an elongation ratio distribution diagram,more than half of CsgA-His nanofibers has an elongation ratio from 0 to 2,some are distributed in 2~10,and a few are distributed in 10~18.The maximum elongation ratio of CsgA-His nanofibers is 17.1,indicating that the fibril’s flexibility is much higher than DNA or silk fiber.For forces less than 20 pN,the extension was reversible.With a 42.1 pN holding force,the extension jumped in steps of from 30 to 365 nm and was irreversible.At the scale tested,the jumps corresponded to the unfolding of multiple beta sheets in the fiber.Work for CsgA-His nanofibers during stretching increase with the normalized strain fractions.The experimental data agree with a theoretical prediction for a single CsgA protein from a SMD calculation.Therefore,our results provide key information for the understandings of CsgA protein nanofiber assembly and biofilm robustness. 展开更多
关键词 FORCE SPECTRUM of Single CsgA NANOFIBER reveal SURPRISING PROPERTIES
下载PDF
Organization and Ultra-Structural Components of Endothelial Surface Glycocalyx Revealed by Stochastic Optical Reconstruction Microscopy(STORM)
15
作者 Jie Fan Yi Sun +2 位作者 Yifan Xia John M.Tarbell Bingmei M.Fua 《医用生物力学》 EI CAS CSCD 北大核心 2019年第A01期6-7,共2页
Introduction The endothelial cells(ECs)lining every blood vessel wall constantly expose to the mechanical forces generated by the blood flow.The EC responses to these hemodynamic forces play a critical role in the hom... Introduction The endothelial cells(ECs)lining every blood vessel wall constantly expose to the mechanical forces generated by the blood flow.The EC responses to these hemodynamic forces play a critical role in the homeostasis of the circulatory system.In addition to forming a transport barrier between the blood and vessel wall,vascular ECs play important roles in regulating circulation functions.Besides biochemical stimuli,blood flow induced(hemodynamic)mechanical stimuli,such as shear stress,pressure and circumferential stretch,modulate EC morphology and functions by activating mechanosensors,signaling pathways,and gene and protein expressions.The EC responses to the hemodynamic forces(mechano-sensing and transduction)are critical to maintaining normal vascular functions.Failure in the mechano-sensing and transduction leads to serious vascular diseases including hypertension,atherosclerosis,aneurysms and thrombosis,to name a few[1].On the luminal surface of our blood vessels,there is a thin layer called endothelial surface glycocalyx(ESG)which consists of proteoglycans,glycosaminoglycans(GAGs)and glycoproteins.The GAGs in the ESG are heparan sulfate(HS),hyaluronic acid(HA),chondroitin sulfate(CS),and sialic acid(SA)[2].In order to play important roles in vascular functions,such as being a mechanosensor and transducer for the endothelial cells(ECs)to sense the blood flow,a molecular sieve to maintain normal microvessel permeability and a barrier between the circulating cells and endothelial cells forming the vessel wall,the ESG should have an organized structure at the molecular level.Due to the limitations of optical and electron microscopy,the ultra-structure and organization of ESG has not been revealed until recent development of a super high resolution fluorescence optical microscope,STORM(Stochastic Optical Reconstruction Microscopy).The diffraction of a single fluorescence molecule can be described as the point spread function(PSF).When the light of wavelengthλexcites the fluorophore(emitter),the intensity profile of the spot is defined as the PSF with the width^0.6λ/NA,NA is the numerical aperture of the objective.The diffraction-limited image resolution,for a high numerical aperture objective lens,is^200 nm in the lateral direction and^500 nm in the axial direction,for a conventional fluorescence microscope.The key idea of the single-molecule localization microscopy is to light the molecule,in turn,to achieve the nanometer-level accuracy of their position and reconstruction into a super-resolution image,such as STORM.STORM employs photo-switching mechanisms to stochastically activate individual molecules(photo-switchable or photoactivatable fluorophores)within the diffraction-limited region at different times.Then images with sub-diffraction limit resolution are reconstructed from the measured positions of individual fluorophores[3].To trade the super spatial resolution(accuracy),STORM sacrifices its temporal resolution(efficiency)by switching the state and sequentially exciting the emitters at a high density.Rust et al[3]employed organic dyes and fluorescent proteins as photo-switchable emitters to trade temporal resolution for a super spatial resolution(~20 nm lateral and^50 nm axial at present,can go down to a couple of nanometers if using smaller peptides or antibody fragments instead of currently used whole anti-bodies),which is an order of magnitude higher than conventional confocal microscopy.In the current study,we employed STORM to reveal the major ultra-structural components of the ESG,HS and HA,and their organization at the surface of the cultured EC monolayer[4].Materials and methods We used newly acquired Nikon-STORM system to observe the ESG on in vitro EC(bEnd3,mouse brain microvascular endothelial cells)monolayers.After confluency,the bEnd3 cells were immunolabeled with anti-HS,fol-lowed by an ATT0488 conjugated goat anti-mouse IgG,and with biotinylated HA binding protein,followed by an AF647 conjugated anti-biotin.The ESG was then imaged by the STORM with a 100x/1.49 oil immersed lens.Multiple Reporters of ATT0488 and AF647 with alternating illumination were used to acquire the 3D images of HS and HA.The field of 256×256(40×40μm2)of HS and HA at the surface of ECs was obtained based on totally 40,000 of EM-CCD captured images for each reporter at a capturing speed of 19 ms/frame.Results HA is a long molecule weaving into a network which covers the endothelial luminal surface.The diameter of the HA segments is 185.3±44.7 nm,155.5±57.2 nm,and 156.9±56.1 nm,respectively,at the top,middle and bottom regions of the cell luminal surface.In contrast,HS is a shorter molecule,perpendicular to the cell surface.HA and HS are partially overlapped with each other at the endothelial luminal surface.We quantified the length,diameter,orientation,and density of HS at the top,middle and bottom regions of the endothelial surface.The diameter of the observed HS is 191.0±46.0 nm,284.3±71.1 nm,and 184.2±59.6 nm,and the length of the HS is 621.0±75.7 nm,651.0±118.0 nm,and 575.2±105.6 nm,respectively,at the top,middle and bottom regions of the cell luminal surface.For the HS orientation,its angle with the cell surface is 92.9±1.9,88.7±8.2,and 96.2±10.9 degree,respectively,at the top,middle and bottom regions.The angle of 90 degree is perfectly perpendicular to the cell surface.For the HS distribution,the average density is0.398 elements/μm2,0.345 elements/μm2 and 0.665 elements/μm2,respectively,and the distance between the adjacent HS is 1 694.4±628.1 nm,1 844.8±758.5 nm,and 1 221.9±450.7 nm,respectively,at the top,middle and bottom regions.Conclusions Our results suggest that HS plays a major role in mechanosensing and HA plays a major role in the molecular sieve,due to their organization,ultra-structure and distribution. 展开更多
关键词 ORGANIZATION Ultra-Structural Components ENDOTHELIAL Surface GLYCOCALYX revealED Optical Reconstruction Microscopy STORM
下载PDF
Hybridization Effects Revealed by Angle-Resolved Photoemission Spectroscopy in Heavy-Fermion Ce2IrIn8
16
作者 Haijiang Liu Yuanji Xu +9 位作者 Yigui Zhong Jianyu Guan Lingyuan Kong Junzhang Ma Yaobo Huang Qiuyun Chen Genfu Chen Ming Shi Yi-feng Yang Hong Ding 《Chinese Physics Letters》 SCIE CAS CSCD 2019年第9期36-40,共5页
We utilize high-resolution resonant angle-resolved photoemission spectroscopy(ARPES)to study the band structure and hybridization effect of the heavy-fermion compound Ce2 IrIn8.We observe a nearly flat band at the bin... We utilize high-resolution resonant angle-resolved photoemission spectroscopy(ARPES)to study the band structure and hybridization effect of the heavy-fermion compound Ce2 IrIn8.We observe a nearly flat band at the binding energy of 7 meV below the coherent temperature Tcoh^40 K,which characterizes the electrical resistance maximum and indicates the onset temperature of hybridization.However,the Fermi vector and the Fermi surface volume have little change around Tcoh,which challenges the widely believed evolution from a hightemperature small Fermi surface to a low-temperature large Fermi surface.Our experimental results of the band structure fit well with the density functional theory plus dynamic mean-field theory calculations. 展开更多
关键词 ARPES HYBRIDIZATION EFFECTS revealED by Angle-Resolved PHOTOEMISSION Spectroscopy in HEAVY-FERMION Ce2IrIn8 Ce
下载PDF
Revealed Cores: Characterizations and Structure
17
作者 Stefano Vannucci 《Applied Mathematics》 2015年第14期2279-2291,共13页
Characterizations of the classes of all choice functions that select the cores or the externally stable cores induced by an underlying revealed dominance digraph are provided. Relying on such characterizations, the ba... Characterizations of the classes of all choice functions that select the cores or the externally stable cores induced by an underlying revealed dominance digraph are provided. Relying on such characterizations, the basic order-theoretic structure of the corresponding sets of revealed cores is also analyzed. In particular, it is shown that the poset of all revealed cores ordered by set inclusion is a median meet semilattice: therefore, any profile of revealed cores may be aggregated by means of the simple majority rule. 展开更多
关键词 Core Choice Functions DOMINANCE DIGRAPHS revealED PREFERENCE
下载PDF
Allosteric Mechanism of Calmodulin Revealed by Targeted Molecular Dynamics Simulation
18
作者 梁倩云 庞春丽 +4 位作者 李军委 张素花 柳辉 展永 安海龙 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第6期121-125,共5页
Calmodulin (CAM) is involved in the regulation of a variety of cellular signaling pathways. To accomplish its physiological functions, CaM binds with Ca2+ at its EF-hand Ca2+ binding sites which induce the conform... Calmodulin (CAM) is involved in the regulation of a variety of cellular signaling pathways. To accomplish its physiological functions, CaM binds with Ca2+ at its EF-hand Ca2+ binding sites which induce the conformational switching of CaM. However, the molecular mechanism by which Ca2+ binds with CaM and induces conformational switching is still obscure. Here we combine molecular dynamics with targeted molecular dynamics simulation and achieve the state-transition pathway of CaM. Our data show that Ca2+ binding speeds up the conformational transition of CaM by weakening the interactions which stabilize the closed state. It spends about 6.5 ns and 5.25 ns for transition from closed state to open state for apo and holo CaM, respectively. Regarding the contribution of two EF-hands, our data indicate that the first EF-hand triggers the conformational transition and is followed by the second one. We determine that there are two interaction networks which contribute to stabilize the closed and open states, respectively. 展开更多
关键词 CA EF TMD Allosteric Mechanism of Calmodulin revealed by Targeted Molecular Dynamics Simulation
下载PDF
Data Transmission Delay in Medtronic Reveal LINQ<sup>TM</sup>Implantable Cardiac Monitor: Clinical Experience in 520 Patients
19
作者 Ronpichai Chokesuwattanaskul Abdul Rahman Safadi +3 位作者 Randy Ip Harsimran Kaur Waraich Olivia Madison Hudson John H. Ip 《Journal of Biomedical Science and Engineering》 2019年第8期391-399,共9页
Background: The Implantable Cardiac Monitor (ICM) is an invaluable tool for detecting cardiac arrhythmias by providing physicians. Critical to the success of ICMs depends on how quickly and accurately the data can be ... Background: The Implantable Cardiac Monitor (ICM) is an invaluable tool for detecting cardiac arrhythmias by providing physicians. Critical to the success of ICMs depends on how quickly and accurately the data can be transmitted to a physician’s office after an arrhythmic event. Then, the clinical event can be analyzed and the treatment will be provided accordingly. However, no reports have been published as to how efficiently the ICM data is transmitted. Methods: There is a retrospective review of 520 patients who received a Medtronic Reveal LINQTM between 2/01/2015 and 6/01/2017. The time from the arrhythmic event to the time of physician notification was calculated and reason for delay was noted. Results: One hundred and twenty patients out of 520 patients (23%) had arrhythmic events transmitted over a mean follow up of 14 ± 4 months. The mean time between cardiac events and physician notification was 15 ± 8 days. Sixty-three percent (63%) of data transmission delay (defined as >24 hours) was due to the MyCareLinkTM Monitor not being in proximity to the patient. Connection failure between the monitor and the network accounted for 34% of data transmission delay. Conclusion: Significant delay in data transmission from Medtronic Reveal LINQTM cardiac monitor occurs frequently impacting patient care. Newer generations of the implantable cardiac monitors utilize Bluetooth technology, enabling immediate transfer of data from ICM to a patient’s cellular phone and subsequently to their physician’s office. This technology could potentially improve efficiency and reliability eliminating the issues of proximity and connectivity. 展开更多
关键词 Connectivity Problems IMPLANTABLE CARDIAC MONITOR reveal LINQ Transmission
下载PDF
Revealing the Pressure-Induced Softening/Weakening Mechanism in Representative Covalent Materials
20
作者 Tengfei Xu Shihao Zhang +2 位作者 Dominik Legut Stan Veprek Ruifeng Zhang 《Chinese Physics Letters》 SCIE CAS CSCD 2021年第5期51-59,共9页
Diamond, cubic boron nitride(c-BN), silicon(Si), and germanium(Ge), as examples of typical strong covalent materials, have been extensively investigated in recent decades, owing to their fundamental importance in mate... Diamond, cubic boron nitride(c-BN), silicon(Si), and germanium(Ge), as examples of typical strong covalent materials, have been extensively investigated in recent decades, owing to their fundamental importance in material science and industry. However, an in-depth analysis of the character of these materials' mechanical behaviors under harsh service environments, such as high pressure, has yet to be conducted. Based on several mechanical criteria, the effect of pressure on the mechanical properties of these materials is comprehensively investigated.It is demonstrated that, with respect to their intrinsic brittleness/ductile nature, all these materials exhibit ubiquitous pressure-enhanced ductility. By analyzing the strength variation under uniform deformation, together with the corresponding electronic structures, we reveal for the first time that the pressure-induced mechanical softening/weakening exhibits distinct characteristics between diamond and c-BN, owing to the differences in their abnormal charge-depletion evolution under applied strain, whereas a monotonous weakening phenomenon is observed in Si and Ge. Further investigation into dislocation-mediated plastic resistance indicates that the pressure-induced shuffle-set plane softening in diamond(c-BN), and weakening in Si(Ge), can be attributed to the reduction of antibonding states below the Fermi level, and an enhanced metallization, corresponding to the weakening of the bonds around the slipped plane with increasing pressure, respectively. These findings not only reveal the physical mechanism of pressure-induced softening/weakening in covalent materials, but also highlights the necessity of exploring strain-tunable electronic structures to emphasize the mechanical response in such covalent materials. 展开更多
关键词 red service revealing the Pressure-Induced Softening/Weakening Mechanism in Representative Covalent Materials
下载PDF
上一页 1 2 52 下一页 到第
使用帮助 返回顶部