检索结果-南通市图书馆

The relationship between MRP1 activities and its NBD conformational changes

Science China(Life Sciences) 2004年第5期47卷 425-433页

作者： HUANG Zhenhua & HUANG Youguo national Laboratory of Biomacromolecules, center for structural and Molecular biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China national Laboratory of Biomacromolecules Center for Structural and Molecular Biology Institute of Biophysics Chinese Academy of Sciences Beijing China

MIANS, a sulfhydryl-reactive fluorescence, was used to label the cysteines of MRP1 (multidrug resistance protein), and the results indicated that an increase in fluorescence intensity and a large emission blue shift took place after two Cys residues of MRP1 reacted with MIANS, which demonstrated that labeled Cys residues in MRP1 reside in a relatively hydrophobic envi-ronment. The experimental results obtained from fluorescence resonance energy transfer further uncover that two Cys residues of MRP1 modified by MIANS located in the vicinity of its NBDs, of which one lies close to NBD1, and the other near NBD2. ATP, ADP and anticancer drugs can all reduce the rate of reaction of MRP1 with MIANS. The collisional quenchers, acrylamide, I-, and Cs+ were used to assess local environments of MIANS bound to MRP1 and the results showed that the region around the MIANS-labeled cysteine is positively charged. Both MIANS and NEM, which are sulfhydryl-reactive reagents, inhibited MRP1 ATPase activity, whereas anticancer drugs activated it. These results demonstrated that all nucleotides and drugs could induce changes in conformation of the NBDs in MRP1. Nucleotides can bind directly to NBDs, but drugs may react first with TMDs, which in turn alters the accessibility of the two Cys residues bound by MIANS and affects MRP1 ATPase activity, which is coupled with the transport of its substrates. Taken together, the above experimental results provide direct evidence for further study on the coupling of translocation of the transported species to hydrolysis of ATP in MRP1.

关键词： MRP1,multidrug resistance,conformation,coupling.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Understanding the local structure and thermophysical behavior of Mg-La liquid alloys via machine learning potential

引用

International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 439-449页

作者： Jia Zhao Taixi Feng Guimin Lu national Engineering Research center for Integrated Utilization of Salt Lake Resource East China University of Science and TechnologyShanghai 200237China Joint International Laboratory for Potassium and Lithium Strategic Resources East China University of Science and TechnologyShanghai 200237China

The local structure and thermophysical behavior of Mg-La liquid alloys were in-depth understood using deep potential molecular dynamic(DPMD) simulation driven via machine learning to promote the development of Mg-La alloys. The robustness of the trained deep potential(DP) model was thoroughly evaluated through several aspects, including root-mean-square errors(RMSEs), energy and force data, and structural information comparison results;the results indicate the carefully trained DP model is reliable. The component and temperature dependence of the local structure in the Mg-La liquid alloy was analyzed. The effect of Mg content in the system on the first coordination shell of the atomic pairs is the same as that of temperature. The pre-peak demonstrated in the structure factor indicates the presence of a medium-range ordered structure in the Mg-La liquid alloy, which is particularly pronounced in the 80at% Mg system and disappears at elevated temperatures. The density, self-diffusion coefficient, and shear viscosity for the Mg-La liquid alloy were predicted via DPMD simulation, the evolution patterns with Mg content and temperature were subsequently discussed, and a database was established accordingly. Finally, the mixing enthalpy and elemental activity of the Mg-La liquid alloy at 1200 K were reliably evaluated,which provides new guidance for related studies.

关键词： magnesium-lanthanum liquid alloys local structure macroscopic properties thermodynamic behavior deep potential mo-lecular dynamic simulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Flow stress and microstructural evolution in as rolled AZ91 alloy during hot deformation

引用

中国有色金属学会会刊：英文版 2003年第6期13卷 1265-1269页

作者：周海涛王渠东尉胤红丁文江朱燕萍 Y.Chino M.Mabuchi national Engineering Research center of Light Alloys Net Forming Institute for structural and Engineering Materials

The flow stress behavior and microstructural evolution in as rolled AZ91 alloy were studied by tensile test at temperature ranging from 573 K to 698 K and with initial strain rate of 10-31s-1. The results show that the activation energy of the AZ91 alloy is 96 kJ/mol and the stress exponent is *** refinement is observed during hot deformation. It is found that grain refinement is due to dynamic recrystallization, but grain size is decreased with increasing Zener-Hollomon parameter. The deformation mechanism is dislocation cross-slip, dislocation climbs and twin intersections, which are probably suitable to the development of substructures. Twins always exist in matrix whether they are at high temperature or at low temperature. Strain induced precipitation of Mg17Al12 occurs in the AZ91 alloy and stabilizes the subgrain boundaries.

关键词： AZ91合金镁合金包金箔热变形显微结构流动压力

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Medicinal plants from the Brazilian Amazonian region and their antileishmanial activity:a review

引用

Journal of Integrative Medicine 2018年第4期16卷 211-222页

作者： Bruno Jose Martins Da Silva Amanda Anastacia Pinto Hage Edilene Oliveira Silva Ana Paula Drummond Rodrigues Laboratory of Parasitology and Laboratory of structural biology Institute of Biological SdencesFederal University of PardBelemPard 66075-110Brazil national Institute of Science and Technology in structural biology and bioimaging Rio de JaneiroRio de Janeiro 21941-901Brazil Laboratory of Electron Microscopy Department of Health SurveillanceMinistry of HealthEvandro Chagas InstituteBelemPard 66087-082Brazil

Leishmaniasis, a neglected disease caused by Leishmania protozoans, primarily affects people in tropical and subtropical areas. Chemotherapy based on the use of pentavalent antimonials, amphotericin B, paromomycin, miltefosine and liposomal amphotericin B is currently the only effective treatment. However, adverse effects, long-term treatment and the emergence of parasite resistance have led to the search for alternative treatments. Natural products used in traditional medicine provide an unlimited source of molecules for the identification of new drugs, and the Amazon region has abundant biodiversity that includes several species of plants and animals, providing a rich source of new products and com- pounds. Although the literature describes numerous promising compounds and extracts for combating Leishmania protozoans, the results of such research have not been embraced by the pharmaceutical industry for the development of new drugs. Therefore, this review focused on the antileishmanial activity of extracts, isolated compounds and essential oils commonly used by the local population in the Brazilian Amazonian region to treat several illnesses and described in the literature as promising compounds for combating leishmaniasis.

关键词： Amazonian plants Leishmaniasis treatment Plant compounds Plant extracts Plant oils

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Sparse Reconstruction and Damage Imaging Method Based on Uniform Sparse Sampling

引用

Acta Mechanica Solida Sinica 2020年第6期33卷 744-755页

作者： Pengfei Li Ying Luo Kan Feng Yang Zhou Chenguang Xu national center for International Research on structural Health Management of Critical Components Jiangsu UniversityZhenjiang 212013China

The full wavefield detection method based on guided waves can efficiently detect and locate damages relying on the collection of large amounts of wavefield *** acquisition process by scanning laser Doppler vibrometer(SLDV)is generally time-consuming,which is limited by Nyquist sampling *** reduce the acquisition time,full wavefield data can be reconstructed from a small number of random sampling point signals combining with compressed ***,the random sampling point signals need to be obtained by adding additional components to the SLDV system or offline *** the random sparse sampling is difficult to achieve via the SLDV system,a new uniform sparse sampling strategy is proposed in this *** using the uniform sparse sampling coordinates instead of the random spatial sampling point coordinates,sparse sampling can be applied to SLDV without adding additional components or offline *** simulation and experimental results show that the proposed strategy can reduce the measurement locations required for accurate signal recovery to less than 90%of the Nyquist sampling grid,and the damage location error is within the minimum half *** with the conventional jittered sampling strategy,the proposed sampling strategy can directly reduce the sampling time of the SLDV system by more than 90%without adding additional components and achieve the same accuracy of guided wavefield reconstruction and damage location as the jittered sampling *** research results can greatly improve the efficiency of damage detection technology based on wavefield analysis.

关键词： Scanning laser Doppler vibrometer Lamb waves Compressed sensing Wavefield sparse reconstruction Damage imaging

来源：

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

Total Focusing Method Damage Imaging in Frequency Domain Using Laser-Ultrasonic Lamb Wave Based on Time-domain Filtering in Multi-band

引用

Acta Mechanica Solida Sinica 2021年第3期34卷 404-424页

作者： Fengzhong Li Ying Luo national center for International Research on structural Health Management of Critical Components Jiangsu UniversityZhenjiang 212013China

A fully non-contact experimental platform for ultrasonic Lamb wave damage detection was constructed,where laser exciting and the scanning laser Doppler vibrometer were used to realize the high-resolution pickup of the Lamb wave field in the structure,which has overcome the disadvantages of low spatial resolution caused by the conventional contact Lamb wave *** order to suppress the dispersion effect of broadband laser-ultrasonic signal,we proposed time-domain filtering in multi-band method based on wavelet analysis to decompose the broadband signal into multiple narrowband ones and separate the scattering signals effectively without reference *** this basis,the total focusing method(TFM)was used for damage ***,when the traditional TFM was applied to image based on ultrasonic Lamb wave,the inherent dispersion characteristic of ultrasonic Lamb wave could lead to the miscalculation of time delay,thus reducing the imaging ***,the frequency-domain TFM was developed by applying phase delay in the frequency *** logical AND was introduced to synthesize the damage imaging results of multiple narrowband signals to obtain high-precision damage *** study has shown that the method of time-domain filtering in multi-band combining with frequency-domain TFM can realize non-contact and accurate damage detection in isotropic plate structures,and it is a potential effective method for application in engineering practice.

关键词： Laser ultrasound Lamb wave Multi-band Wavelet analysis Dispersion Total focusing method

来源：

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

structural insight into acute intermittent porphyria

引用

生物物理学报 2009年第S1期25卷 356-357页

作者： Ang Gao Andrzej Joachimiak Neil Shaw national Laboratory of Biomacromolecules Institute of Biophysics Chinese Academy of Sciences structural biology center Advanced Photon Source Argonne National Laboratory

Acute intermittent porphyria (AIP), an inherited disease of heme biosynthesis, is one of the most common type of the porphyrias. Reduced activity of the enzyme

关键词： human porphobilinogen deaminase X-ray structure heme biosynthesis porphobilinogen hinge

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

structural Insight into Recognition of Plant Peptid Hormones by Receptors

引用

Molecular Plant 2016年第11期9卷 1454-1463页

作者： Heqiao Zhang Zhifu Han Wen Song Jijie Chai Innovation center for structural biology Tsinghua-Peking Joint Center for Life Sciences School of Life Sciences Tsinghua University Beijing 100084 China

Secreted signaling peptides or peptide hormones play crucial roles in plant growth and development through coordination of cell-cell communication. Perception of peptide hormones in plants generally relies on membrane-localized receptor kinases （RKs）. Progress has recently been made in structural elucidation of interactions between posttranslationally modified peptide hormones and RKs. The structural studies suggest conserved receptor binding and activation mechanisms of this type of peptide hormones involving their conserved C-termini. Here, we review these structural data and discuss how the conserved mecha- nisms can be used to match peptide-RK pairs.

关键词： peptide hormones small signaling peptides receptor kinases ligand recognition posttranslationalmodifications

来源：

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

Mechanotransduction via the coordinated actions of integrins,PI3K signaling and Connexin hemichannels

引用

Bone Research 2021年第1期9卷 86-96页

作者： Manuel A.Riquelme Sumin Gu Rui Hua Jean X.Jiang Department of Biochemistry and structural biology University of Texas Health Science CenterSan AntonioTX 78229-3900USA

Mechanical loading opens connexin 43(Cx43)hemichannels(HCs),leading to the release of bone anabolic molecules,such as prostaglandins,from mechanosensitive osteocytes,which is essential for bone formation and ***,the mechanotransduction mechanism that activates HCs remains ***,we report a unique pathway by which mechanical signals are effectively transferred between integrin molecules located in different regions of the cell,resulting in HC *** integrinα5 andαV were activated upon mechanical stimulation via either fluid dropping or flow shear stress(FSS).Inhibition of integrinαV activation or ablation of integrinα5 prevented HC opening on the cell body when dendrites were mechanically stimulated,suggesting mechanical transmission from the dendritic integrinαV toα5 in the cell body during HC *** addition,HC function was compromised in vivo,as determined by utilizing an antibody blockingαV activation andα5-deficient osteocyte-specific knockout ***,inhibition of integrinαV activation,but not that ofα5,attenuated activation of the phosphoinositide 3-kinase(PI3K)-protein kinase B(AKT)signaling pathway upon mechanical loading,and the inhibition of PI3K/AKT activation blocked integrinα5 activation and HC ***,HC opening was blocked only by an anti-integrinαV antibody at low but not high FSS levels,suggesting that dendriticαV is a more sensitive mechanosensor thanα5 for activating ***,these results reveal a new molecular mechanism of mechanotransduction involving the coordinated actions of integrins and PI3K/AKT in osteocytic dendritic processes and cell bodies that leads to HC opening and the release of key bone anabolic factors.

关键词： PI3K/AKT stimulation coordinated

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of Pre-cold Rolling-Induced Twins and Subsequent Precipitated x-Phase on Mechanical Properties in a β-Type Ti–Mo Alloy

引用

Acta Metallurgica Sinica(English Letters) 2018年第6期31卷 604-614页

作者： Li Xiang Xiao-Hua Min Xin Ji Satoshi Emura Cong-Qian Cheng Koichi Tsuchiya School of Materials Science and Engineering Dalian University of Technology Research center for structural Materials National Institute for Materials Science

This paper reported an effectiveness of pre-cold rolling-induced{332}／113[twins combined with subsequent isothermal x-phase formation for enhancement of uniform elongation in a b-type Ti–15Mo alloy with high yield strength ***{332}／113[twins were induced by cold rolling with an thickness reduction of 5%,which had little effect on x-phase precipitation after aging at 573 K for 3.6 *** after the cold rolling was further activated during tensile deformation,even with the presence of isothermal *** combination of twins and x-phase enhanced uniform elongation from 0 to 9%at yield strength level of 890 *** high yield strength was mainly dominated by dislocation slip due to the isothermal x-phase formation,and early onset of plastic instability after yielding was hindered due to the pre-cold rolling-induced *** microstructural refinement was induced by further twinning activation during deformation,which resulted in high work hardening rate corresponding enhancement of uniform elongation.

关键词： β-Type titanium alloy Pre-cold rolling Twinning deformation Isothermal x-phase Strength-ductility

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：