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Volatile anesthetics inhibit the activity of calmodulin by interacting with its hydrophobic site

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Chinese Medical Journal 2012年第17期125卷 3166-3170页

作者： ZHOU Miao-miao XIA Hui-min LIU Jiao xu you-nian XIN Nai-xin ZHANG Shi-hai Department of Anesthesiology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan Hubei 430022China

Background Volatile anesthetics （VAs） may affect varied and complex physiology processes by manipulating Ca2＋-calmodulin （CAM）. However, the detailed mechanism about the action of VAs on CaM has not been elucidated. This study was undertaken to examine the effects of VAs on the conformational change, hydrophobic site, and downstream signaling pathway of CaM, to explore the possible mechanism of anesthetic action of VAs. Methods Real-time second-harmonic generation （SHG） was performed to monitor the conformational change of CaM in the presence of VAs, each plus 100 μmol/L Ca2＋. A hydrophobic fluorescence indicator, 8-anilinonaphthalene-l-sulfonate （ANS）, was utilized to define whether the VAs would interact with CaM at the hydrophobic site or not. High-performance liquid chromatography （HPLC） was carried out to analyze the activity of CaM-dependent phosphodiesterase （PDE1） in the presence of VAs. The VAs studied were ether, enflurane, isoflurane, and sevoflurane, with their aqueous concentrations 7.6, 9.5, 11.4 mmol/L; 0.42, 0.52, 0.62 mmol/L; 0.25, 0.31, 0.37 mmol/L and 0.47, 0.59, 0.71 mmol/L respectively, each were equivalent to their 0.8, 1.0 and 1.2 concentration for 50% of maximal effect （EC50） for general anesthesia. Results The second-harmonic radiation of CaM in the presence of Ca2＋ was largely inhibited by the VAs. The fluorescence intensity of ANS, generated by binding of Ca2＋ to CaM, was reversed by the VAs. HPLC results also showed that AMP, the product of the hydrolysis of cAMP by CaM-dependent PDE1, was reduced by the VAs. Conclusions Our findings demonstrate that the above VAs interact with the hydrophobic core of Ca2＋-CaM and the interaction results in the inhibition of the conformational change and activity of CaM. This in vitro study may provide us insight into the possible mechanism of anesthetic action of VAs in vivo.

关键词： volatile anesthetics calmodulin hydrophobic site phosphodiesterase 1

Mechanism of a dual-phase Ti-Nb alloy exhibiting near-linear elastic deformation

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Rare Metals 2024年第5期43卷 2282-2289页

作者： Yan Guo Wang Ding Wen Ma Shun Guo Hao-Dong Meng nian-Yao xu School of Automotive Engineering Changzhou Institute of TechnologyChangzhou 213032China School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013China youke Publishing Co. LtdChina Grinm Group Co.LtdBeijing 100088China

In this work,the underlying mechanism responsible for the near-linear elastic deformation behavior of a dual-phase Ti-Nb alloy consisting of β and α'' phase with large recoverable strain was systematically *** on in situ synchrotron X-ray diffraction(SXRD)analyses,it was found that besides intrinsic elastic deformation,a slight reversible β-α'' stress-induced martensitic(SIM)transformation,which proceeded in a consecutive mode under the retarding effect of micro-defects,took place during the near-linear elastic *** unloading,a small amount of residual macroscopic strain remained in the specimen due to the incomplete reverse α''→β transformation on *** high near-linear elastic deformability of the cold drawing(CD)Ti-Nb alloy has been revealed to be attributed to the coupling actions of intrinsic elasticity as well as the consecutive and reversible β-α'' SIM *** research may contribute to a new avenue for the design and development of novel dual-phase Ti-based alloys with desirable elastic deformability.

关键词： Titanium alloys Dual-phase Near-linear elastic deformation Martensitictransformation

Reshaping the Cortical Connectivity Gradient by Long-Term Cognitive Training During Development

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Neuroscience Bulletin 2024年第1期40卷 50-64页

作者： Tianyong xu Yunying Wu Yi Zhang Xi-nian Zuo Feiyan Chen Changsong Zhou Bio-X Laboratory School of PhysicsZhejiang UniversityHangzhou 310027China Qiushi Academy for Advanced Studies Zhejiang UniversityHangzhou 310027China State Key Laboratory of Modern Optical Instrumentation College of Optical Science and EngineeringZhejiang UniversityHangzhou 310027China State Key Laboratory of Cognitive Neuroscience and Learning Bejing Normal UniversityBeijing 100875China Developmental Population Neuroscience Research Center IDG/McGovern Institute for Brain ResearchBeijing Normal UniversityBeijing 100875China Zhejiang Province Key Laboratory of Quantum Technology and Devices Zhejiang UniversityHangzhou 310027China Department of Physics Centre for Nonlinear Studies and Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Systems(Hong Kong)Institute of Computational and Theoretical StudiesHong Kong Baptist UniversityHong Kong 999077China

The organization of the brain follows a topologi-cal hierarchy that changes dynamically during ***,it remains unknown whether and how cognitive training administered over multiple years during develop-ment can modify this hierarchical *** measuring the brain and behavior of school children who had carried out abacus-based mental calculation(AMC)training for five years(starting from 7 years to 12 years old)in pre-training and post-training,we revealed the reshaping effect of long-term AMC intervention during development on the brain hierarchical *** observed the development-induced emergence of the default network,AMC training-promoted shifting,and regional changes in cortical ***,the training-induced gradient changes were located in visual and somatomotor areas in association with the visuospatial/motor-imagery *** found that gradient-based features can predict the math ability within *** findings provide novel insights into the dynamic nature of network recruitment impacted by long-term cognitive training during development.

关键词： Connectivity gradient Cognitive training Development Neural plasticity Abacus-based mental calculation

Optimized Auxiliary Frequency Control of Wind Farm Based on Piecewise Reduced-order Frequency Response Model

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 791-802页

作者： xu Zhang Chen Zhao Junchao Ma Long Zhang Dan Sun Chenxu Wang Yan Peng Heng nian the School of Electrical Engineering Zhejiang UniversityHangzhou 310058China Electric Power Research Institute of State Grid Zhejiang Electric Power Corporation Hangzhou 310014China

With the increasing wind power penetration in the power system,the auxiliary frequency control(AFC)of wind farm(WF)has been widely *** traditional system frequency response(SFR)model is not suitable for the wind power generation system due to its poor accuracy and *** this paper,a piecewise reduced-order frequency response(PROFR)model is proposed,and an optimized auxiliary frequency control(O-AFC)scheme of WF based on the P-ROFR model is ***,a full-order frequency response model considering the change in operating point of wind turbine is established to improve the *** order to simplify the fullorder model,a P-ROFR model with second-order structure and high accuracy at each frequency response stage is *** on the proposed P-ROFR model,the relationship between the frequency response indexes and the auxiliary frequency controller coefficients is expressed ***,an OAFC scheme with the derived explicit expression as the optimization objective is proposed in order to improve the frequency support capability on the premise of ensuring the full release of the rotor kinetic energy and the full use of the effect of time delay on frequency ***,the effectiveness of the proposed P-ROFR model and the performance of the proposed OAFC scheme are verified by simulation studies.

关键词： Frequency response piecewise reduced-order wind farm auxiliary frequency control

Nontraditional energy-assisted mechanical machining of difficult-to-cut materials and components in aerospace community:a comparative analysis

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International Journal of Extreme Manufacturing 2024年第2期6卷 190-271页

作者： Guolong Zhao Biao Zhao Wenfeng Ding Lianjia Xin Zhiwen nian Jianhao Peng Ning He Jiuhua xu College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016People’s Republic of China

The aerospace community widely uses difficult-to-cut materials,such as titanium alloys,high-temperature alloys,metal/ceramic/polymer matrix composites,hard and brittle materials,and geometrically complex components,such as thin-walled structures,microchannels,and complex *** machining is the main material removal process for the vast majority of aerospace ***,many problems exist,including severe and rapid tool wear,low machining efficiency,and poor surface *** energy-assisted mechanical machining is a hybrid process that uses nontraditional energies(vibration,laser,electricity,etc)to improve the machinability of local materials and decrease the burden of mechanical *** provides a feasible and promising method to improve the material removal rate and surface quality,reduce process forces,and prolong tool ***,systematic reviews of this technology are lacking with respect to the current research status and development *** paper reviews the recent progress in the nontraditional energy-assisted mechanical machining of difficult-to-cut materials and components in the aerospace *** addition,this paper focuses on the processing principles,material responses under nontraditional energy,resultant forces and temperatures,material removal mechanisms,and applications of these processes,including vibration-,laser-,electric-,magnetic-,chemical-,advanced coolant-,and hybrid nontraditional energy-assisted mechanical ***,a comprehensive summary of the principles,advantages,and limitations of each hybrid process is provided,and future perspectives on forward design,device development,and sustainability of nontraditional energy-assisted mechanical machining processes are discussed.

关键词： difficult-to-cut materials geometrically complex components nontraditional energy mechanical machining aerospace community

Multiple paradoxical embolisms caused by central venous catheter thrombus passing through a patent foramen ovale: A case report

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World Journal of Clinical Cases 2024年第4期12卷 842-846页

作者： Jian-Duan Li nian xu Qiang Zhao Biao Li Li Li Department of Cardiology Guangzhou Red Cross Hospital of Jinan UniversityGuangzhou 510235Guangdong ProvinceChina

BACKGROUND To date,this is the first case of a paradoxical embolism(PDE)that concurrently manifested in the coronary and lower limb arteries and was secondary to a central venous catheter(CVC)thrombus via a patent foramen ovale(PFO).CASE SUMMARY Here,we report a case of simultaneous coronary and lower limb artery embolism in a PFO patient carrier of a *** patient presented to the hospital with acute chest pain and lower limb *** ultrasound showed a large thrombus in the right internal jugular vein,precisely at the tip of the *** and transesophageal echocardiography confirmed the existence of a PFO,with inducible right-to-left shunting by the Valsalva *** patient was administered an extended course of anticoagulation therapy,and then the CVC was successfully *** PFO closure was not *** was no recurrence during *** Thus,CVC-associated thrombosis is a potential source for multiple PDE in PFO patients.

关键词： Paradoxical embolism Central venous catheter Patent foramen ovale Acute myocardial infarction Case report

MOF-mediated synthesis of novel PtFeCoNiMn high-entropy nanoalloy as bifunctional oxygen electrocatalysts for zinc-air battery

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Nano Research 2024年第6期17卷 5288-5297页

作者： Mingkuan Xie Xin Xiao Duojie Wu Cheng Zhen Chunsheng Wu Wenjuan Wang Hao nian Fayan Li Meng Danny Gu Qiang xu Shenzhen Key Laboratory of Micro/Nano-Porous Functional Materials(SKLPM) Shenzhen 518055China Department of Chemistry Southern University of Science and TechnologyShenzhen 518055China Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China SUSTech-Kyoto University Advanced Energy Materials Joint Innovation Laboratory(SKAEM-JIL) Shenzhen 518055China Key University Laboratory of Highly Efficient Utilization of Solar Energy and Sustainable Development of Guangdong Southern University of Science and TechnologyShenzhen 518055China Eastern Institute for Advanced Study Eastern Institute of TechnologyNingbo 315200China

High-entropy alloy(HEA)-based materials are expected to be promising oxygen electrocatalysts due to their exceptional *** electronic structure regulation of HEAs plays a pivotal role in enhancing their elctrocatalytic ***,PtFeCoNiMn nanoparticles(NPs)with subtle lattice distortions are constructed on metal-organic framework-derived nitrogen-doped carbon by an ultra-rapid Joule heating *** to the modulated electronic structure and the inherent cocktail effect of HEAs,the as-synthesized PtFeCoNiMn/NC exhibits superior bifunctional electrocatalytic performance with a positive half-wave potential of 0.863 V *** hydrogen electrode(RHE)for oxygen reduction reaction and a low overpotential of 357 mV at 10 mA·cm^(-2)for oxygen evolution *** assembled quasi-solid-state zinc-air battery using PtFeCoNiMn/NC as air electrode shows a high peak power density of 192.16 mW·cm^(-2),low charge−discharge voltage gap,and excellent durability over 500 cycles at 5 mA·cm^(-2).This work demonstrates an effective route for rational design of bifunctional nanostructured HEA electrocatalysts with favorable electronic structures,and opens up a fascinating directions for energy storage and conversion,and beyond.

关键词： oxygen reduction reaction oxygen evolution reaction high-entropy nano-alloy zinc-air battery

Semi-volatile organic compounds in a museum in China:A non-targeted screening approach

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Science China(Technological Sciences) 2024年第9期67卷 2693-2705页

作者： SONG ZiDong nian LuYing SHI Meng REN XiaoPeng TANG Ming SHI AnMei HAN Ying LIU Min WANG LuYang ZHANG YinPing xu Ying FENG XiaoMeng Department of Building Science Tsinghua UniversityBeijing 100084China Beijing Key Laboratory of Indoor Air Quality Evaluation and Control Beijing 100084China National Museum of China Beijing 100006China Department of Endocrinology Beijing Chao-Yang HospitalCapital Medical UniversityBeijing 100020China

Non-targeted analysis(NTA)was conducted to identify semi-volatile organic compounds(SVOCs)in a museum in China using the gas chromatography(GC)-Orbitrap-mass spectrometer(MS).Approximately 160 SVOCs were detected,of which 93 had not been reported in previous studies of museum *** of the detected SVOCs were found to be associated with the chemical agents applied in conservation treatment and the materials used in *** results of hierarchical cluster analysis(HCA)indicated a spatial variation of SVOCs in the indoor air in the museum,but there were no obvious temporal differences of SVOCs observed in indoor ***'s correlation analysis showed that several classes of SVOCs were well correlated,suggesting their common *** and plasticizers were found to be the primary sources of SVOC pollution detected in the *** with compounds in outdoor air,indoor SVOCs had a lower level of unsaturation and more portions of chemically reduced *** study is the first of its kind to comprehensively characterize SVOCs in a museum using an automated NTA approach with *** SVOCs identified in the current study are likely to be present in other similar museums;therefore,further examination of their potential impacts on cultural heritage artifacts,museum personnel,and visitors may be warranted.

关键词： non-target analysis high-resolution mass spectrometry semi-volatile organic compounds museum environment air pollutants

Summer Warming Limited Bud Output Drives a Decline in Daughter Shoot Biomass through Reduced Photosynthetis of Parent Shoots in Leymus chinensis Seedlings

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Phyton-International Journal of Experimental Botany 2024年第7期93卷 1667-1675页

作者： Song Gao Ruocheng xu Lin Li Jiao Wang nian Liu Johannes M.H.Knops Junfeng Wang Graduate School Changchun UniversityChangchun130022China Key Laboratory of Vegetation Ecology Ministry of EducationInstitute of Grassland ScienceSchool of Life SciencesJilin Songnen Grassland Ecosystem National Observation and Research StationNortheast Normal UniversityChangchun130024China Jilin Agricultural Radio and Television School Changchun130599China Department of Health and Environmental Sciences Xi’an Jiaotong Liverpool UniversitySuzhou215000China

Understanding how summer warming inﬂuences the parent and daughter shoot production in a perennial clonal grass is vital for comprehending the response of grassland productivity to global ***,we conducted a simulated experiment using potted Leymus chinensis,to study the relationship between the photosynthetic activ-ity of parent shoots and the production of daughter shoots under a whole(90 days)summer warming scenario(+3°C).The results showed that the biomass of parents and buds decreased by 25.52%and 33.45%,respectively,under warming *** reduction in parent shoot biomass due to warming directly resulted from decreased leaf area(18.03%),chlorophyll a(18.27%),chlorophyll b(29.21%)content,as well as a reduction in net photosynthetic rate(7.32%)and the maximum quantum efﬁciency of photosystem II(PSII)photochemistry(4.29%).The decline in daughter shoot biomass was linked to a decrease in daughter shoot number(33.33%)by ***,the number of belowground buds increased by 46.43%.The results indicated that long-term summer warming reduces biomass accumulation in parent shoot by increasing both limitation of stoma and ***,the parent shoot allocates relatively more biomass to the belowground organs to maintain the survival and growth of ***,buds,as a potential aboveground population,could remedy for the cur-rent loss of parent shoot density by increasing the number of future daughter shoots if summer warming subsides.

关键词： Warming parent shoot bud bank photosynthesis chlorophyllﬂuorescence Leymus chinensis