检索结果-南通市图书馆

Photodamage to Pigment in the Photosystem Ⅱ Reaction Center D1/D2/Cytochrome b559 Complex

维普期刊数据库评论

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 Integrative Plant Biology 2006年第7期48卷 800-806页

作者： Shuang liu Feng-Qin Dong Chong-Qin Tang Ting-yun Kuang Liang-Bi Li yu-long liu Institute of Botany the Chinese Academy of Sciences Beijing 100093 China Institute of Physics the Chinese Academy of Sciences Beijing 100080 China

Strong light （800μmol photons/m^2 per s）-induced bleaching of the pigment in the isolated photosystem Ⅱ reaction center （PSII RC） under aerobic conditions （in the absence of electron donors or acceptors） was studied using high-pressure liquid chromatography （HPLC）, absorption spectra, 77K fluorescence spectra and resonance Raman spectra. Changes in pigment composition of the PSII RC as determined by HPLC after light treatment were as follows： with Increasing illumination time chlorophyll （Chl） a and β-carotene （β-car） content decreased. However, decreases in pheophytin （Pheo） could not be observed because of the mixture of the Pheo formed by degraded chlorophyll possibly. On the basis of absorption spectra, it was determined that, with a short time of illuminatlon, the initial bleaching occurred maximally at 680 nm but that with Increasing Illumination time there was a blue shift to 678 nm. It was suggested that P680 was destroyed Initially, followed by the accessory chlorophyll. The activity of P680 was almost lost after 10 mln light treatment. Moreover, the bleaching of Pheo and β-car was observed at the beginning of illumination. After Illumination, the fluorescence emission Intensity changed and the fluorescence maximum blue shifted, showing that energy transfer was disturbed. Resonance Raman spectra of the PSII RC excited at 488.0 and 514.5 nm showed four main bands, peaking at 1 527 cm^-1 （υ101）, 1 159 cm^-1 （υ2）, 1 006 cm^-1 （υ3）, 966 cm^-1 （υ4） for 488.0 nm excitation and 1 525 cm^-1 （υ1）, 1 159 cm^-1 （υ2）, 1 007 cm^-1 （υ3）, 968 cm^-1 （υ4） for 514.5 nm excitation. It was confirmed that two spectroscopically different β-car molecules exist In the PSII RC. After light treatment for 20 mln, band positions and bandwidths were unchanged. This indicates that carotenoid configuration Is not the parameter that regulates photoprotectlon in the PSII RC.

关键词： high-pressure liquid chromatography (HPLC) photodamage photosystem Ⅱ reaction center (PSII RC) resonance Raman spectroscopy

Synchronization in PT-symmetric optomechanical resonators

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonics Research 2021年第11期9卷 2152-2166页

作者： CHANG-long ZHU yu-long liu LAN YANG yu-XI liu JING ZHANG Department of Automation Tsinghua UniversityBeijing 100084China Beijing Academy of Quantum Information Sciences Beijing 100193China Department of Electrical and Systems Engineering Washington UniversitySt.LouisMissouri 63130USA institute of Microelectronics Tsinghua UniversityBeijing 100084China Center for Quantum Information Science and Technology BNRistBeijing 100084China

Synchronization has great impacts in various fields such as self-clocking,communication,and neural ***,we present a mechanism of synchronization for two mechanical modes in two coupled optomechanical resonators with a parity-time(PT)-symmetric *** is shown that the degree of synchronization between the two far-off-resonant mechanical modes can be increased by decreasing the coupling strength between the two optomechanical resonators due to the large amplification of optomechanical interaction near the exceptional ***,when we consider the stochastic noises in the optomechanical resonators by working near the exceptional point,we find that more noises can enhance the degree of synchronization of the system under a particular parameter *** results open up a new dimension of research for PT-symmetric systems and synchronization.

关键词： structure symmetric exceptional

Lignin-reinforced PVDF electrolyte for dendrite-free quasi-solid-state Li metal battery

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第3期43卷 1006-1016页

作者： Xin-Yang Chen Xue-Jie Gao Han-Yan Wu yu-long liu Xiao-Fei Yang Run-Cang Sun Center for Lignocellulosic Chemistry and Biomaterials College of Light Industry and Chemical EngineeringDalian Polytechnic UniversityDalian116034China Division of Energy Storage Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian116023China School of Chemistry Northeast Normal UniversityChangchun130024China

Quasi-solid-state lithium metal batteries(QSSLMBs)assembled with polyvinylidene fluoride(PVDF)are a promising class of next-generation rechargeable batteries due to their safety,high energy density,and superior interfacial ***,PVDF has a series of inherent drawbacks such as low ionic conductivity,ease of crystallization,and hydrophobic character that leading to poor cell *** tackle these issues,a lignin-reinforced PVDF electrolyte is proposed in this work to solve these drawbacks of PVDF and enhance the comprehensive performance of *** lithophilic polar groups of lignin can promote uniform deposition of Li on the *** with the improved mechanical properties can efficiently prevent Li dendrites penetration through the *** addition,more active sites provided by lignin can also enhance Li^(+)transport and lead to a faster electrochemical reaction *** from the ingenious design,Li symmetric cells with 5%lignin-PVDF quasi-solid-state electrolyte can operate for 900 h at a high current density/capacity of 5 mA·cm^(-2)/5 mAh·cm^(-2),while shortcircuiting occurs after 56 h for the counterpart(pure PVDF).Moreover,a full cell of Li/5%lignin-PVDF/LFP cell demonstrates a high capacity of 96.2 mAh·g^(-1)after 2000 cycles at 10 *** work is expected to open up promising opportunities to develop other high-energy/power-density QSSLMBs.

关键词： Quasi-solid-state electrolyte Lignin PVDF Dendrite-free Li metal battery

The complex effects of miR-146a in the pathogenesis of Alzheimer's disease

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第5期20卷 1309-1323页

作者： yunfan long Jiajia liu yu Wang Haidong Guo Guohong Cui Department of Neurology Shanghai No.9 People’s HospitalShanghai Jiaotong University School of MedicineShanghaiChina Academy of Integrative Medicine Shanghai University of Traditional Chinese MedicineShanghaiChina School of Integrative Medicine Shanghai University of Traditional Chinese MedicineShanghaiChina Department of Neurology Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese MedicineShanghaiChina

Alzheimer's disease is a neurodegenerative disorder characterized by cognitive dysfunction and behavioral *** plaques formed through the extracellular deposition of amyloid-βproteins,as well as neurofibrillary tangles formed by the intracellular deposition of hyperphosphorylated tau proteins,comprise two typical pathological features of Alzheimer's *** symptomatic treatment,there are no effective therapies for delaying Alzheimer's disease ***(miR)are small,non-coding RNAs that negatively regulate gene expression at the transcriptional and translational levels and play important roles in multiple physiological and pathological ***,miR-146a,a NF-κB-regulated gene,has been extensively implicated in the development of Alzheimer's disease through several *** has demonstrated substantial dysregulation of miR-146a both during the initial phases and throughout the progression of this *** R-146a is believed to reduce amyloid-βdeposition and tau protein hyperphosphorylation through the TLR/IRAK1/TRAF6 pathway;however,there is also evidence supporting that it can promote these processes through many other pathways,thus exacerbating the pathological manifestations of Alzheimer's *** has been widely reported that miR-146a mediates synaptic dysfunction,mitochondrial dysfunction,and neuronal death by targeting m RNAs encoding synapticrelated proteins,mitochondrial-related proteins,and membrane proteins,as well as other *** the impact on glial cells,miR-146a also exhibits differential *** one hand,it causes widespread and sustained inflammation through certain pathways,while on the other hand,it can reverse the polarization of astrocytes and microglia,alleviate neuroinflammation,and promote oligodendrocyte progenitor cell differentiation,thus maintaining the normal function of the myelin sheath and exerting a protective effect on *** this review,we provide a

关键词： Alzheimer's disease amyloid-β glial cells microRNAs miR-146a neuroinflammatory

Clinical evaluation of double-bundle anterior cruciate ligament reconstruction procedure using hamstring tendon grafts： a prospective, randomized and controlled study

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2009年第6期122卷 706-711页

作者： WANG Jian-quan AO Ying-fang yu Chang-long liu Ping XU Yan CHEN Lin-xin Institute of Sports Medicine Peking University Third Hospital Beijing 100083 China

Background In clinical studies there is still a lot of controversy about the increased anterior and rotational stability between double-bundle （DB） and single-bundle （SB） anterior cruciate ligament （ACL） reconstruction. The aim of this study was to evaluate the clinical results of four-tunnel DB ACL reconstruction.Methods Sixty-four consecutive patients with ACL ruptures from May 2005 to May 2006 were randomly assigned into two groups： 32 cases for SB ACL reconstruction and 32 cases for DB ACL reconstruction. Clinical data, including KT 2000, Biodex test, Lysholm score, Tegner score and IKDC score, were prospectively collected until at least 10 months post-operative.Results The average values of KT 2000 were （1.47±1.17） mm and （1.68±1.14） mm for the SB and DB ACL reconstruction groups at 30° of knee flexion （P 〉0.05）, and were （1.04±0.98） mm and （1.13±0.98） mm at 90° of knee flexion （P 〉0.05）. There were also no significant differences in Lysholm score, Tegner score, IKDC score and Biodex test scores between the two groups （P 〉0.05）. The operation time of DB ACL reconstruction was 20 minutes longer than the SB ACL reconstruction （P 〈0.05）Conclusion Double bundle ACL reconstructions have no obvious clinical advantages over single bundle ACL reconstructions.

关键词： anterior cruciate ligament semitendinosus tendon gracilis tendon double bundle reconstruction

Induction of gynogenesis in red crucian carp using spermatozoa of blunt snout bream

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第2期17卷 163-167页

作者： SUN yuandong, TAO Min, liu Shaojun, ZHANG Chun, DUAN Wei, SHEN Jiamin, WANG Jing, ZENG Chen, long yu and liu yun (Key Laboratory of Protein Chemistry and Developmental Biology of State Education Ministry of China, College of Life Sciences, Hunan Normal University, Changsha 410081, China) [a]Key Laboratory of Protein Chemistry and Developmental Biology of State Education Ministry of China College of Life Science Human Normal University Changsha China

Gynogenetic diploid was induced in red crucian carp (RCC) ( Carassius auratus Red Variety) eggs using UV-irradiated spermatozoa from blunt snout bream (B) (Megalobrama amblycephaia) or from mirror carp (C) (Cyprinus carpio. L) . Spermatozoa were genetically inactivated by an appropriate UV dosage, and then the maternal DNA was duplicated with cold shock at 0-4℃. When using the spermatozoa of B, the fertilization rate, hatching rate and survival at first feeding were 52. 6±3. 0 %, 23.6±4.1 % and15.7±3.4 % , respectively, and the survival at first feeding was significantly higher than that (11.3±2.2%) when using the spermatozoa of C (Cyprinus carpio. L). According to the morphological characteristics, the chromosome number and the degree of gonadal development, gynogenetic RCC could be distinguished from the control hybrids of RCC♀×B♂. The individuals with red body color, 100 chromosomes and normal gonadal development were successful gynogenetic RCC, while the individuals with 124 or 148 chromosomes and delayed gonadal development were hybrids of (RCC×B). The triploid hybrids (RCC×B) (2 years old) were sterile, but the tetraploid hybrids (RCC×B) were sexually mature age of two. In the present study, compared to the spermatozoa of C, the advantages of spermatozoa of B as the activation source were that could increase the survival at first feeding of gynogenetic individuals and simplify the confirmation of gynogenetic status, which suggested that the sperm of B was an effective activation source for inducing gynogenesis in crucian carp.

关键词： Megalobrama amblycephala Carassius auratus red variety gynogenesis tetraploid triploid.

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

机构投资者行为对信息效率的影响研究

北京工商大学学报（社会科学版） 2016年第5期31卷 87-97页

作者：陶瑜彭龙刘寅北京邮电大学经济管理学院北京100876 北京外国语大学北京100089

中国机构投资者在过去十几年规模和数量都取得了快速发展,但其在资本市场中扮演什么样的角色一直没有定论。通过考察2006—2014年机构投资者持股和交易行为,研究发现我国股票市场整体股价同步性偏高,机构投资者持股比例高的股票股价同... 详细信息

中国机构投资者在过去十几年规模和数量都取得了快速发展,但其在资本市场中扮演什么样的角色一直没有定论。通过考察2006—2014年机构投资者持股和交易行为,研究发现我国股票市场整体股价同步性偏高,机构投资者持股比例高的股票股价同步性更低,而机构投资者交易的增加却未能降低股价同步性。机构持股和机构交易对股价同步性的影响机制和对不同规模的股票影响不尽相同,通过进一步考察不同类型机构投资者行为对股价同步性的影响,发现各类型机构投资者影响存在差异,其中信托、养老基金和QFII的持股和交易行为都会降低股价同步性,有利于市场信息效率的提高。为了维护资本市场稳定和提高市场效率,应在继续大力发展机构投资者的同时改善机构投资者结构并优化基金经理业绩考核体系。

关键词：机构投资者信息效率股价同步性股票市场资本市场市场稳定性

Palladium-Catalyzed Intramolecular bromoamination of Alkenes

在线全文

学校读者我要写书评

暂无评论

Palladium-Catalyzed Intramolecular bromoamination of Alkenes

Sporadic E responds to the 2022 Tonga volcano eruptions recorded by the Meridian Project

中国化学会第九届全国有机化学学术会议

作者： Jing-fang Zhang yu-long liu Xiao-yun Wang Xie Wang Wei He Department of Chemistry School of Pharmacy Fourth Military Medical University

Nitrogen-containing heterocyclic compounds are important intermediates of many natural products,biologically active molecules and *** the research on the synthesis of them has wide application and practical *** this article,a facile and mild Pd-catalyzed intramolecular bromoamination of substituted alkenes has been *** optimum catalytic reaction system and reaction conditions were ***（II）bis（triphenylphosphine）dichloride acted as the optimal source of palladium,and N-bromosuccinimide（NBS）was bromination reagent *** configuration of five-membered brominated pyrrolidine products were obtained at room temperature within 1 h,execllent regioselectivity of the reaction was achieved ***-four kinds of bromopyrrole products were synthesized in total,including twenty-three species of unknown *** the yield was up to 98%.The structures were confirmed by IR,1H NMR,13C NMR and *** absolute configuration of the products was also obtained based on the X-ray crystallographic.

关键词： Palladium-Catalyzed bromoamination Nitrogen-containing heterocyclic compounds

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2025年第1期9卷 20-28页

作者： YangYi Sun Tao yu Jin Wang Chi long School of Geophysics and Geomatics China University of Geosciences(Wuhan)Wuhan 430047China School of Physics and Electronic Science Guizhou Normal UniversityGuizhou 550001China

In this study,ionosonde observations over Fuke(19.5°N,109.1°E),Wuhan(30.5°N,114.4°E),and Mohe(53.5°N,122.3°E)were analyzed to demonstrate the responses of the sporadic E()to the severe atmospheric disturbances caused by the Tonga volcanic eruptions on January 15,*** most prominent signature was the disappearance of the layer after~10:00 UT over Wuhan and Fuke,which was attributed to the vertical drift caused by the *** occurred intermittently after 13:00 UT following the arrival of the tropospheric Lamb *** examine the causal mechanism for the intermittence,we also included data of horizontal winds in the mesosphere and lower thermosphere region recorded by the meteor radars at Wuhan and Mohe in this *** wind disturbances with periods of~20 hours contributed to the formation of the layer in the nighttime on January 15.

关键词： sporadic E Tonga eruptions neutral wind disturbances