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Chiral Lewis Base/Achiral Acid Co-Catalyzed Atroposelective Sulfenylation of Pyrrole Derivatives: Construction of C-N Axially Chiral Sulfides

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Chinese Journal of Chemistry 2024年第17期42卷 2005-2009页

作者： Qin Yang hui-Yun Luo Deng zhu Xin-Yu Zhang Hua ke Zhi-Min Chen School of Chemistry and Chemical Engineering Shanghai Key Laboratory for Molecular Engineering of Chiral DrugsShanghai Jiao Tong UniversityShanghai 200240China Engineering Technooy Rearch Centeror Enviromental Proction Materas Pingxng Universty PingangJiangx355China State key Laboratory of Applied Organic Chemistry Lanzhou UniversityLanzhouGansu 730000China

Chiral BINAM-derived selenide/achiral acid co-catalyzed atroposelective electrophilic sulfenylation of pyrrole derivatives has been realized for the first time.A variety of C-N axially chiral sulfur-containing pyrrole derivatives were readily obtained in moderate to good yields with moderate to excellent *** catalytic system involves sequential desymmetrization and kinetic resolution.

关键词： Electrophilic substitution Desymmetrization Kinetic resolution Atropisomerism Asymmetric catalysis Heterocycles

In vivo label-free measurement of blood flow velocity symmetry based on dual line scanning third-harmonic generation microscopy excited at the 1700 nm window

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Journal of Innovative Optical Health Sciences 2024年第1期17卷 61-68页

作者： hui Cheng Jincheng Zhong Ping Qiu ke Wang key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Physics and Optoelectronic Engineering Shenzhen University Shenzhen 518060 P.R.China

Measurement of bloodflow velocity is key to understanding physiology and pathology in *** most measurements are performed at the middle of the blood vessel,little research has been done on characterizing the instantaneous bloodflow velocity *** is mainly due to the lack of measurement technology with high spatial and temporal ***,we tackle this problem with our recently developed dual-wavelength line-scan third-harmonic generation(THG)imaging *** acquisition of dual-wavelength THG line-scanning signals enables measurement of bloodflow velocities at two radially symmetric positions in both venules and arterioles in mouse brain in *** results clearly show that the instantaneous bloodflow velocity is not symmetric under general conditions.

关键词： 1700 nm-Window third-harmonic generation imaging blood flow velocity

ProNet Adaptive Retinal Vessel Segmentation Algorithm Based on Improved UperNet Network

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Computers, Materials & Continua 2024年第1期78卷 283-302页

作者： Sijia zhu Pinxiu Wang ke Shen CW Chu College Jiangsu Normal UniversityXuzhou221000China Biomedical Engineering College Southern Medical UniversityGuangzhou510080China

This paper proposes a new network structure,namely the ProNet *** medical image segmentation can help clinical diagnosis of related eye diseases and is essential for subsequent rational *** baseline model of the ProNet network is UperNet(Unified perceptual parsing Network),and the backbone network is ConvNext(Convolutional Network).A network structure based on depth-separable convolution and 1×1 convolution is used,which has good performance and *** further optimise ProNet mainly in two *** is data enhancement using increased noise and slight angle rotation,which can significantly increase the diversity of data and help the model better learn the patterns and features of the data and improve the model’s ***,it can effectively expand the training data set,reduce the influence of noise and abnormal data in the data set on the model,and improve the accuracy and reliability of the *** is the loss function aspect,and we finally use the focal loss *** focal loss function is well suited for complex tasks such as object *** function will penalise the loss carried by samples that the model misclassifies,thus enabling better training of the model to avoid these errors while solving the category imbalance problem as a way to improve image segmentation density and segmentation *** the experimental results,the evaluation metrics mIoU(mean Intersection over Union)enhanced by 4.47%,and mDice enhanced by 2.92% compared to the baseline *** generalization effects and more accurate image segmentation are achieved.

关键词： Retinal segmentation multifaceted optimization cross-fusion data enhancement focal loss

Deep Reinforcement Learning-Based Task Offloading and Service Migrating Policies in Service Caching-Assisted Mobile Edge Computing

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China Communications 2024年第4期21卷 88-103页

作者： ke Hongchang Wang hui Sun Hongbin Halvin Yang School of Computer Technology and Engineering Changchun Institute of TechnologyChangchun 130012China College of Computer Science and Engineering Changchun University of TechnologyChangchun 130012China Department of Electronic and Electrical Engineering University College LondonLondonUK

Emerging mobile edge computing(MEC)is considered a feasible solution for offloading the computation-intensive request tasks generated from mobile wireless equipment(MWE)with limited computational resources and *** to the homogeneity of request tasks from one MWE during a longterm time period,it is vital to predeploy the particular service cachings required by the request tasks at the MEC *** this paper,we model a service caching-assisted MEC framework that takes into account the constraint on the number of service cachings hosted by each edge server and the migration of request tasks from the current edge server to another edge server with service caching required by ***,we propose a multiagent deep reinforcement learning-based computation offloading and task migrating decision-making scheme(MBOMS)to minimize the long-term average weighted *** proposed MBOMS can learn the near-optimal offloading and migrating decision-making policy by centralized training and decentralized *** and comprehensive simulation results reveal that our proposed MBOMS can converge well after training and outperforms the other five baseline algorithms.

关键词： deep reinforcement learning mobile edge computing service caching service migrating

Ultrafast photo-induced turning of magnetization and its relaxation dynamics in GaMnAs

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Science China(Physics,Mechanics & Astronomy) 2010年第5期53卷 779-782页

作者： LUO Jing,ZHENG HouZhi,SHEN Chao,ZHANG Hao,zhu ke,zhu hui,LIU Jian,LI GuiRong,JI Yang & ZHAO JianHua State key Laboratory for Superlattices and Microstructures,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China State key Laboratory for Superlattices and Microstructures Institute of Semiconductors Chinese Academy of Sciences Beijing China

We report that,by linearly polarized pumping of different wavelengths,kerr transients appear at zero magnetic field only in the case when GaMnAs samples are initialized at 3 K by first applying a 0.8 Tesla field and then returning to zero *** find that,instead of magnetization precession,the near-band gap excitation induces a coherent out-of-plane turning of magnetization,which shows very long relaxation dynamics with no *** photon energy increases,the peak value of the kerr transient increases,but it decays rapidly to the original slow transient seen under the near-band-gap excitation.

关键词： dilute magnetic semiconductor magneto-crystalline anisotropy time-resolved kerr rotation coherent precession

Recent progresses in thermal treatment of β-Ga_(2)O_(3) single crystals and devices

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International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1659-1677页

作者： Yuchao Yan zhu Jin hui Zhang Deren Yang State key Laboratory of Silicon and Advanced Semiconductor Materials and School of Materials Science and Engineering Zhejiang UniversityHangzhou 310027China Zhejiang Provincial key Laboratory of Power Semiconductor Materials and Devices ZJU-Hangzhou Global Scientific and Technological Innovation CenterHangzhou 311200China

In recent years,ultra-wide bandgap β-Ga_(2)O_(3) has emerged as a fascinating semiconductor material due to its great potential in power and photoelectric *** semiconductor industrial,thermal treatment has been widely utilized as a convenient and effective approach for substrate property modulation and device ***,a thorough summary of β-Ga_(2)O_(3) substrates and devices behaviors after high-temperature treatment should be *** this review,we present the recent advances in modulating properties of β-Ga_(2)O_(3) substrates by thermal treatment,which include three major applications:(ⅰ)tuning surface electrical properties,(ⅱ)modifying surface morphology,and(ⅲ)oxidating ***,regulating electrical contacts and handling with radiation damage and ion implantation have also been discussed in device *** each category,universal annealing conditions were speculated to figure out the corresponding problems,and some unsolved questions were proposed *** review could construct a systematic thermal treatment strategy for various purposes and applications of β-Ga_(2)O_(3).

关键词： β-gallium oxide thermal treatment substrates devices

Association of acute glycemic parameters at admission with cardiovascular mortality in the oldest old with acute myocardial infarction

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Journal of Geriatric Cardiology 2024年第3期21卷 349-358页

作者： hui-hui LIU Meng ZHANG Yuan-Lin GUO Cheng-Gang zhu Na-Qiong WU Ying GAO Rui-Xia XU Jie QIAN ke-Fei DOU Jian-Jun LI Cardiometabolic Center State Key Laboratory of Cardiovascular DiseaseFuwai HospitalNational Center for Cardiovascular DiseasesNational Clinical Research Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

OBJECTIVES Stress-related glycemic indicators,including admission blood glucose(ABG),stress-hyperglycemia ratio(SHR),and glycemic gap(GG),have been associated with worse outcomes after acute myocardial infarction(AMI).However,data regarding their prognostic value in the oldest old with AMI are ***,this study aimed to investigate the association of stress-related glycemic indicators with short-and long-term cardiovascular mortality(CVM)in the oldest old(≥80 years)with *** In this prospective study,a total of 933 consecutive old patients with AMI admitted to FuWai hospital(Beijing,China)were *** admission,ABG,SHR,and GG were assessed and all participants were classified according to their ***-Meier,restricted cubic splines(RCS),and multivariate Cox regression analyses were performed to evaluate the association between these glycemic indicators and CVM within 30 days and long-term *** During an average of 1954 patient-years of follow-up,a total of 250 cardiovascular deaths were ***-Meier analyses showed the lowest CVM in quartile 1 of ABG and in quartile 2 of SHR and *** adjusting for potential covariates,patients in quartile 4 of ABG,SHR,and GG had a respective 1.67-fold(95%CI:1.03-2.69;P=0.036),1.80-fold(95%CI:1.16-2.79;P=0.009),and 1.78-fold(95%CI:1.14-2.79;P=0.011)higher risk of long-term CVM risk compared to those in the reference groups(quartile 1 of ABG and quartile 2 of SHR and GG).Furthermore,RCS suggested a J-shaped relationship of ABG and a Ushaped association of SHR and GG with long-term ***,we observed similar associations of these acute glycemic parameters with 30-day *** Our data first indicated that SHR and GG consistently had a U-shaped association with both 30-day and longterm CVM among the oldest old with AMI,suggesting that they may be useful for risk stratification in this special population.

关键词： admitted infarction shaped

Preventing formation of intermetallic compounds in ultrasonic-assisted Sn soldering of Mg/Al alloys through pre-plating a Ni coating layer on the Mg substrate

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Journal of Magnesium and Alloys 2024年第2期12卷 726-741页

作者： Yingzong Liu Yuanxing Li hui Chen Zongtao zhu key Laboratory of Advanced Technologies of Materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031PR China

Magnesium and aluminum alloys are widely used in various industries because of their excellent properties,and their reliable connection may increase application of *** compounds(IMCs)affect the joint performance of Mg/*** this study,AZ31 Mg alloy with/without a nickel(Ni)coating layer and 6061 Al alloy were joined by ultrasonic-assisted soldering with Sn-3.0Ag-0.5Cu(SAC)*** effects of the Ni coating layer on the microstructure and mechanical properties of Mg/Al joints were systematically *** Ni coating layer had a significant effect on formation of the Mg_(2)Sn IMC and the mechanical properties of Mg/Al *** blocky Mg_(2)Sn IMC formed in the Mg/SAC/Al joints without a Ni coating *** content of the Mg_(2)Sn IMC increased with increasing soldering temperature,but the joint strength *** joint without a Ni coating layer fractured at the blocky Mg_(2)Sn IMC in the solder,and the maximum shear strength was 32.2 *** pre-plating Ni on the Mg substrate,formation of the blocky Mg_(2)Sn IMC was inhibited in the soldering temperature range 240–280℃and the joint strength ***,when the soldering temperature increased to 310℃,the blocky Mg_(2)Sn IMC precipitated again in the *** electron microscopy showed that some nano-sized Mg_(2)Sn IMC and the(Cu,Ni)_(6)Sn_(5)phase formed in the Mg(Ni)/SAC/Al joint soldered at 280℃,indicating that the Ni coating layer could no longer prevent diffusion of Mg into the solder when the soldering temperature was higher than 280℃.The maximum shear strength of the Mg(Ni)/SAC/Al joint was 58.2 MPa for a soldering temperature of 280℃,which was 80.7%higher than that of the Mg/SAC/Al joint,and the joint was broken at the Mg(Ni)/SAC ***-plating Ni is a feasible way to inhibit formation of IMCs when joining dissimilar metals.

关键词： Ultrasonic-assisted soldering Mg_(2)Sn Ni coating layer Shear strength

USP19 Stabilizes TAK1 to Regulate High Glucose/Free Fatty Acid-induced Dysfunction in HK-2 Cells

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Current Medical Science 2024年第4期44卷 707-717页

作者： Xiao-hui YAN Yin-na zhu Yan-ting zhu Kidney Disease and Dialysis Center Shaanxi Provincial People's HospitalXi'an 710068China Department of Nephrology The Third Affiliated Hospital of Xi'an Medical UniversityXi'an 710000China Nephrology and Hemodialysis Center Shaanxi Provincial People's HospitalXi'an 710068China

Objective Obesity-induced kidney injury contributes to the development of diabetic nephropathy(DN).Here,we identified the functions of ubiquitin-specific peptidase 19(USP19)in HK-2 cells exposed to a combination of high glucose(HG)and free fatty acid(FFA)and determined its association with TGF-beta-activated kinase 1(TAK1).Methods HK-2 cells were exposed to a combination of HG and ***19 mRNA expression was detected by quantitative RT-PCR(qRT-PCR),and protein analysis was performed by immunoblotting(IB).Cell growth was assessed by Cell Counting Kit-8(CCK-8)viability and 5-ethynyl-2′-deoxyuridine(EdU)proliferation *** cycle distribution and apoptosis were detected by flow *** USP19/TAK1 interaction and ubiquitinated TAK1 levels were assayed by coimmunoprecipitation(Co-IP)assays and *** In HG+FFA-challenged HK-2 cells,USP19 was highly ***19 knockdown attenuated HG+FFA-triggered growth inhibition and apoptosis promotion in HK-2 ***,USP19 knockdown alleviated HG+FFA-mediated PTEN-induced putative kinase 1(PINK1)/Parkin pathway inactivation and increased mitochondrial reactive oxygen species(ROS)generation in HK-2 ***,USP19 stabilized the TAK1 protein through ***,increased TAK1 expression reversed the USP19 knockdown-mediated phenotypic changes and PINK1/Parkin pathway activation in HG+FFA-challenged HK-2 *** The findings revealed that USP19 plays a crucial role in promoting HK-2 cell dysfunction induced by combined stimulation with HG and FFAs by stabilizing TAK1,providing a potential therapeutic strategy for combating DN.

关键词： HK-2 cells high glucose free fatty acid dysfunction USP19 deubiquitination