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Lewis Base Catalyzed Selenofunctionalization of Alkynes with Acid-Controlled Divergent Chemoselectivity

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Chinese Journal of Chemistry 2024年第14期42卷 1623-1629页

作者： Ling-Ling chen Ren-Fei Cao hua Ke Zhi-Min chen School of Chemistry and Chemical Engineering Shanghai Key Laboratory for Molecular Engineering of Chiral DrugsShanghai Jiao Tong UniversityShanghai200240 China Engineering Technology Research Center for Environmental Protection Materials Pingxiang UniversityPingxiangJiangxi337055 China

Lewis base catalyzed and Brønsted acid controlled chemodivergent electrophilic selenofunctionalizations of alkynes were developed for the first *** selenium-containing tetrasubstituted alkenes were readily obtained in moderate to excellent yields with complete E/Z *** the substrates were 1-ethynyl naphthol derivatives,linear selenium-containing tetrasubstituted alkenes were produced via intermolecular oxygen nucleophilic attack in the absence of acid additive;in contrast,cyclic selenium-containing tetrasubstituted alkenes were generated through intramolecular carbon nucleophilic capture with the addition of Brønsted acid.

关键词： Alkynes Electrophilic addition Chemoselectivity Lewis base catalysis Selenofunctionalization

Variable projection algorithms with sparse constraint for separable nonlinear models

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Control Theory and Technology 2024年第1期22卷 135-146页

作者： Hui-Lang Xu Guang-Yong chen Si-qing cheng Min Gan Jing chen College of Computer and Data Science Fuzhou UniversityFuzhou350116FujianChina Fujian Key Laboratory of Network Computing and Intelligent Information Processing Fuzhou UniversityFuzhou350116FujianChina Key Laboratory of Intelligent Metro of Universities in Fujian Fuzhou UniversityFuzhou350116FujianChina Engineering Research Center of Big Data Intelligence Ministry of EducationFuzhou UniversityFuzhou350116FujianChina School of Science Jiangnan UniversityWuxi214122JiangsuChina

Separable nonlinear models are widely used in various fields such as time series analysis, system modeling, and machine learning, due to their flexible structures and ability to capture nonlinear behavior of data. However, identifying the parameters of these models is challenging, especially when sparse models with better interpretability are desired by practitioners. Previous theoretical and practical studies have shown that variable projection (VP) is an efficient method for identifying separable nonlinear models, but these are based on \(L_2\) penalty of model parameters, which cannot be directly extended to deal with sparse constraint. Based on the exploration of the structural characteristics of separable models, this paper proposes gradient-based and trust-region-based variable projection algorithms, which mainly solve two key problems: how to eliminate linear parameters under sparse constraint;and how to deal with the coupling relationship between linear and nonlinear parameters in the model. Finally, numerical experiments on synthetic data and real time series data are conducted to verify the effectiveness of the proposed algorithms.

关键词： Variable projection(VP) Non-smooth constraint Separable nonlinear models

Plasma metabolites and risk of myocardial infarction:a bidirectional Mendelian randomization study

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Journal of Geriatric Cardiology 2024年第2期21卷 219-231页

作者： Dong-hua LI Qiang WU Jing-Sheng LAN Shuo chen You-Yi huaNG Lan-Jin WU Zhi-qing QIN Ying huaNG Wan-Zhong huaNG Ting ZENG Xin HAO hua-Bin SU Qiang SU Department of Cardiovascular Medicine Minzu Hospital of Guangxi Zhuang Autonomous RegionGuangxiChina Senior Department of Cardiology the Sixth Medical CenterChinese PLA General HospitalBeijingChina Library of Graduate School Chinese PLA General HospitalBeijingChina Department of Cardiology Jiangbin Hospital of Guangxi Zhuang Autonomous RegionGuangxiChina Health Management Institute the Second Medical CenterChinese PLA General HospitalBeijingChina

BACKGROUND Myocardial infarction(MI)is a critical cardiovascular event with multifaceted etiology,involving several genetic and environmental *** is essential to understand the function of plasma metabolites in the development of MI and unravel its complex *** This study employed a bidirectional Mendelian randomization(MR)approach to investigate the causal relationships between plasma metabolites and MI *** used genetic instruments as proxies for plasma metabolites and MI and conducted MR analyses in both directions to assess the impact of metabolites on MI risk and vice *** addition,the large-scale genome-wide association studies datasets was used to identify genetic variants associated with plasma metabolite(1400 metabolites)and MI(20,917 individuals with MI and 440,906 individuals without MI)*** variance weighted was the primary method for estimating causal *** estimates are expressed as beta coefficients or odds ratio(OR)with 95%*** We identified 14 plasma metabolites associated with the occurrence of MI(P<0.05),among which 8 plasma metabolites[propionylglycine levels(OR=0.922,95%CI:0.881–0.965,P<0.001),gamma-glutamylglycine levels(OR=0.903,95%CI:0.861–0.948,P<0.001),hexadecanedioate(C16-DC)levels(OR=0.941,95%CI:0.911–0.973,P<0.001),pentose acid levels(OR=0.923,95%CI:0.877–0.972,P=0.002),X-24546 levels(OR=0.936,95%CI:0.902–0.971,P<0.001),glycine levels(OR=0.936,95%CI:0.909–0.964,P<0.001),glycine to serine ratio(OR=0.930,95%CI:0.888–0.974,P=0.002),and mannose to trans-4-hydroxyproline ratio(OR=0.912,95%CI:0.869–0.958,P<0.001)]were correlated with a decreased risk of MI,whereas the remaining 6 plasma metabolites[1-palmitoyl-2-arachidonoyl-GPE(16:0/20:4)levels(OR=1.051,95%CI:1.018–1.084,P=0.002),behenoyl dihydrosphingomyelin(d18:0/22:0)levels(OR=1.076,95%CI:1.027–1.128,P=0.002),1-stearoyl-2-docosahexaenoyl-GPE(18:0/22:6)levels(OR=1.067,95%CI:1.027–1.109,P=0.001),alpha-ketobutyrate levels(OR=1.108,95%

关键词： infarction alterations diagnosis

Spiral CT localization of pancreatic function-ing islet cell tumors

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Hepatobiliary & Pancreatic Diseases International 2004年第4期3卷 616-619页

作者： qing Xu, Wen-hua chen and qing-Juan huang Nanjing, China Department of Radiology, First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China Department of Radiology, Third Affiliated Hospital of Suzhou Univer- sity, Changzhou 213003, China Department of Radiology First Affiliated Hospital of Nanjing Medical University Nanjing 210029 China. xuqingst@***

BACKGROUND: Surgeons are always concerned about the localization of pancreatic functioning islet cell tumor. If the tumor is accurately localized before operation, resection of the pancreatic body and tail without intention can be avoided. The purpose of this study was to evaluate spiral CT localization of pancreatic functioning islet cell tumors and CT techniques. METHODS: CT manifestations in 6 patients with clinically and pathologically proved pancreatic functioning islet cell tumors ware analyzed retrospectively. RESULTS: In 4 patients with insulinomas and 2 patients with glucagonomas, 5 were localized accurately by CT be- fore surgery and 1 was detected retrospectively. The en- hancement of tumors was greater than that of normal pan- creas in arterial phase and pancreatic parenchymal phase. Four patients showed mild high-density and 2, iso-density in the portal venous phase. CONCLUSION: Spiral CT multi-phase enhanced scan with 1.5 ml/kg contrast agent and 2-5 mm slice width can loca- lize functioning islet cell tumors accurately.

关键词： islet cell tumor spiral CT enhanced scan

Identifying the risk factors for pancreatic fistula after laparoscopic pancreaticoduodenectomy in patients with pancreatic cancer

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World Journal of Gastrointestinal Surgery 2024年第6期16卷 1609-1617页

作者： Hang Xu qing-Cai Meng Jie hua Wei Wang Department of Pancreatic Surgery Fudan University Shanghai Cancer CenterShanghai 200032China Department of Oncology Shanghai Medical CollegeFudan UniversityShanghai 200032China

BACKGROUND Laparoscopic pancreaticoduodenectomy(LPD)is a surgical procedure for treating pancreatic cancer;however,the risk of complications remains high owing to the wide range of organs involved during the surgery and the difficulty of *** fistula(PF)is a major complication that not only increases the risk of postoperative infection and abdominal hemorrhage but may also cause multi-organ failure,which is a serious threat to the patient’s *** study hypothesized the risk factors for PF after *** To identify the risk factors for PF after laparoscopic pancreatoduodenectomy in patients with pancreatic *** We retrospectively analyzed the data of 201 patients admitted to the Fudan University Shanghai Cancer Center between August 2022 and August 2023 who underwent LPD for pancreatic *** the basis of the PF’s incidence(grades B and C),patients were categorized into the PF(n=15)and non-PF groups(n=186).Differences in general data,preoperative laboratory indicators,and surgery-related factors between the two groups were compared and analyzed using multifactorial logistic regression and receiver-operating characteristic(ROC)curve *** The proportions of males,combined hypertension,soft pancreatic texture,and pancreatic duct diameter≤3 mm;surgery time;body mass index(BMI);and amylase(Am)level in the drainage fluid on the first postoperative day(Am>1069 U/L)were greater in the PF group than in the non-PF group(P24.91 kg/m²[odds ratio(OR)=13.978,95%confidence interval(CI):1.886-103.581],hypertension(OR=8.484,95%CI:1.22-58.994),soft pancreatic texture(OR=42.015,95%CI:5.698-309.782),and operation time>414 min(OR=15.41,95%CI:1.63-145.674)were risk factors for the development of PF after LPD for pancreatic cancer(all P<0.05).The areas under the ROC curve for BMI,

关键词： Pancreatic cancer Laparoscopy Pancreaticoduodenectomy Pancreatic fistula Risk factors Receiver-operating characteristic curve

Defect engineered electrocatalysts for C-N coupling reactions toward urea synthesis

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Chinese Chemical Letters 2024年第8期35卷 7-14页

作者： Shengkai Li Yuqin Zou chen chen Shuangyin Wang Zhao-qing Liu Guangzhou Key Laboratory for Clean Energy and Materials/Key Laboratory for Water Quality and Conservation of the Pearl River Delta Ministry of EducationGuangzhou UniversityGuangzhou 510006China State Key Laboratory of Chemo/Bio-Sensing and Chemometrics College of Chemistry and Chemical EngineeringAdvanced Catalytic Engineering Research Center of the Ministry of EducationHunan UniversityChangsha 410082China

Urea is extensively used in agriculture and chemical industry,and it is produced on an industrial scale from CO_(2)and Haber-Bosch NH_(3)under relatively high temperature and high pressure conditions,which demands high energy input and generates masses of carbon *** conversion of CO_(2)and N sources(such as NO_(2)^(−),NO_(3)^(−),and N_(2))through electrocatalytic reactions under ambient conditions is a promising alternative to realize efficient urea *** note,the design of electrocatalyst is one of the key factors that can improve the efficiency and selectivity of C-N coupling *** engineer-ing is an intriguing strategy for regulating the electronic structure and charge density of electrocatalysts,which endows electrocatalysts with excellent physicochemical properties and optimized adsorption en-ergy of the reaction intermediates to reduce the kinetic *** this minireview,recent advances of defect engineered electrocatalysts in urea electrosynthesis from CO_(2)and various N reactants are firstly *** discussions of C-N coupling in these advances are presented,with the aim of directing future investigations on improving the urea ***,the prospects and challenges of de-fect engineered electrocatalysts for urea synthesis are *** overview is expected to provide in-depth understanding of structure-reactivity relationship and shed light on future electrocatalytic C-N coupling reactions.

关键词： Electrocatalysis Defective electrocatalyst Co-reduction C-N coupling Urea synthesis

Research progress in CALPHAD assisted metal additive manufacturing

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China Foundry 2024年第4期21卷 295-310页

作者： Ya-qing Hou Xiao-qun Li Wei-dong Cai qing chen Wei-ce Gao Du-peng He Xue-hui chen Hang Su China Iron&Steel Research Institute Group Beijing 100081China Thermo-Calc Software AB SolnaSE-169Sweden KTH Royal Institute of Technology StockholmSE-100Sweden Central Iron and Steel Research Institute Beijing 100081China

Metal additive manufacturing(MAM)technology has experienced rapid development in recent *** both equipment and materials progress towards increased maturity and commercialization,material metallurgy technology based on high energy sources has become a key factor influencing the future development of *** calculation of phase diagrams(CALPHAD)is an essential method and tool for constructing multi-component phase diagrams by employing experimental phase diagrams and Gibbs free energy models of simple *** combining with the element mobility data and non-equilibrium phase transition model,it has been widely used in the analysis of traditional metal *** development of CALPHAD application technology for MAM is focused on the compositional design of printable materials,the reduction of metallurgical imperfections,and the control of microstructural *** endeavor carries considerable theoretical and practical *** paper summarizes the important achievements of CALPHAD in additive manufacturing(AM)technology in recent years,including material design,process parameter optimization,microstructure evolution simulation,and properties ***,the limitations of applying CALPHAD technology to MAM technology are discussed,along with prospective research directions.

关键词： metal additive manufacturing CALPHAD integrated computational material engineering powder bed fusion material design microstructure simulation

Atomistic study of inverse size effect induced by interfacial plasticity in pearlitic multi-principal element alloy

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Rare Metals 2024年第7期43卷 3341-3355页

作者： chen Yang Qiao-Sheng Xia Cun-Hong Yin Dong-Peng hua College of Mechanical Engineering Guizhou UniversityGuiyang 550025China Key Laboratory of Advanced Manufacturing Technology Ministry of EducationGuizhou UniversityGuiyang 550025China State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi'an 710072China

Owing to the fine nano-laminated structure,the pearlitic multi-principal element alloy(PMPEA) exhibits excellent mechanical and tribological ***,the incomplete understanding of the size effect of its lamella thickness and the unclear understanding of the plasticity-interface interaction mechanism limit further optimization of *** this study,the FeCoNi/Ni_3Ti interface-mediated plastic deformation behavior in PMPEA and the variation of mechanical and tribological properties with lamella thickness within the nanoscale range using molecular dynamics(MD) simulation were *** results indicate that the mechanical and tribological properties of the PMPEA with lamella thicknesses below 10 nm have a significant inverse size effect,i.e.,the smaller the lamella thickness,the weaker the *** is because the plastic carrier-interface interaction mechanism changes from a strengthening mechanism that hinders dislocations to a weakening mechanism that promotes dislocations with the decreases in the lamella thickness,and the weakening effect becomes more pronounced as the lamella thickness decreases and the number of interfaces *** particular,the deformation behavior of Ni_3Ti lamellae changes from crystal-like to amorphous-like with decreasing ***,in the sample with larger lamella thickness,the occurrence of hierarchical slips in the body-centered cubic(BCC) phase due to the multiprincipal elements effect can better alleviate the stress concentration caused by the dislocation accumulation at the interface,so that the phase interface exhibits outstanding load-bearing *** the dislocation pattern in BCC phase shows a firm high-density cell,which makes the substrate exhibit a stable tribological response.

关键词： Multi-principal element alloy Nano-laminated structure Molecular dynamics simulation Nanoindentation and nanoscratch

Current status of Mycoplasma pneumoniae infection in China

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World Journal of Pediatrics 2024年第1期20卷 1-4页

作者： Chao Yan Guan-hua Xue Han-qing Zhao Yan-Ling Feng Jing-hua Cui Jing Yuan Department of Bacteriology Capital Institute of PediatricsNo.2Yabao RoadBeijing 100020People's Republicof China

Mycoplasma pneumoniae(***)is one of the most important pathogens for community-acquired pneumonia worldwide,especially in children and adolescents[1,2].*** is easily transmitted through droplets or direct contact in densely populated,enclosed,or poorly ventilated *** incubation period is 1-3 weeks,and it is contagious from the incubation period to a few weeks after clinical symptom *** infection can occur in any season,and there are differences in the epidemic seasons among regions in China[3].The most suitable culture temperature for *** is between 35℃C and 37 C,and therefore,hot weather may make it survive longer in the environment and spread *** is more common in autumn and winter in northern China,while it is more prevalent in summer and autumn in southern China.

关键词： winter weather autumn