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Solvent-free esterification of poly(vinyl alcohol) and maleic anhydride through mechanochemical reaction

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Chinese Chemical Letters 2007年第11期18卷 1353-1356页

作者： Bo zhao can Hui Lu Mei Liang State Key Laboratory of Polymer Materials Engineering Polymer Research Institute Sichuan University Chengdu 610065 China

A solid-state mechanochemical processing, that is, pan-milling, was used to conduct the esterification of poly（vinyl alcohol）（PVA） with maleic anhydride （MA） through stress-induced reaction. FTIR spectrum study indicated the presence of ester linkages and olefinic double bonds in maleic anhydride cross-linked PVA. Thermal properties of the cross-linked product were characterized by DSC. The results showed its glass transition temperature was 20 ℃ higher than the original linear PVA and the thermal stability was also improved.

关键词： Mechanochemical synthesis Estedfication Poly(vinyl alcohol) Maleic anhydride

Kinematics constrained five-axis tool path planning for high material removal rate

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Science China(Technological Sciences) 2011年第12期54卷 3155-3165页

作者： YE Tao XIONG CalHua XIONG YouLun zhao can State Key Laboratory of Digital Manufacturing Equipment and Technology School of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China Modern Manufacturing Engineering Center Heilongjiang University of Science and Technology Harbin 150027 China

Traditional five-axis tool path planning methods mostly focus on differential geometric characteristics between the cutter and the workpiece surface to increase the material removal rate(i.e.,by minimizing path length,improving curvature matching,maximizing local cutting width,etc.) . However,material removal rate is not only related to geometric conditions such as the local cutting width,but also constrained by feeding speed as well as the motion capacity of the five-axis machine. This research integrates machine tool kinematics and cutter-workpiece contact kinematics to present a general kinematical model for five-axis machining process. Major steps of the proposed method include:(1) to establish the forward kinematical relationship between the motion of the machine tool axes and the cutter contact point;(2) to establish a tool path optimization model for high material removal rate based on both differential geometrical property and the contact kinematics between the cutter and workpiece;(3) to convert cutter orientation and cutting direction optimization problem into a concave quadratic planning(QP) model. Tool path will finally be generated from the underlying optimal cutting direction field. Through solving the time-optimal trajectory generation problem and machining experiment,we demonstrate the validity and effectiveness of the proposed method.

关键词： tool path material removal rate contact motion quadratic planning

Synergistic asymmetric diarylation of tethered alkenes via C–H functionalization of simple(hetero)arenes

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Science China Chemistry 2024年第8期67卷 2710-2718页

作者： Jian Yao can zhao Lili Shao Xiaohong Huo Xiaoming Wang Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs Frontiers Science Center for Transformative MoleculesSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Organometallic Chemistry and Shanghai Hongkong Joint Laboratory in Chemical Synthesis Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China School of Chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China

By virtue of the atom-and step-economy, utilization of simple arenes as a supplant of pre-prepared aryl metal species or aryl halides for the synthesis of arylated chiral molecules has attracted great attention from the synthetic community. While transition-metal-catalyzed enantioselective diarylation of tethered alkenes has been employed to prepare important chiral cyclic compounds, the direct use of simple arenes as aryl precursors is still underdeveloped, probably due to the difficulties in the effective control of the reactivity, site-selectivity and/or enantioselectivity. Herein we report an asymmetric Pd/Ag dual metal catalytic system for the non-directed, site-and enantioselective domino Heck/intermolecular C–H functionalization of *** studies showed that Pd and Ag act in cooperation in the catalysis and the chiral bisphosphine ligand plays a bifunctional role, i.e., assisting the silver species in the cleavage of the aryl C–H bond, while inducing the enantioselectivity on direct complexation with palladium. This method provides an efficient approach to the corresponding chiral oxindoles with good enantiomeric excesses from a broad scope of arenes, including fluoroarenes, heteroarenes and several complex products derived from medicines or natural products.

关键词： asymmetric Pd/Ag dual metal catalytic system simple arenes C–H functionalization bifunctional role chiral oxindoles

Atomic layer deposition of zinc oxide onto 3D porous iron scaffolds for bone repair:in vitro degradation,antibacterial activity and cytocompatibility evaluation

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Rare Metals 2022年第2期41卷 546-558页

作者： Yu-Lei Li Jin He Hai-Xia Ye can-can zhao Wei-Wei Zhu Xiong Lu Fu-Zeng Ren Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Institute of Applied Physics and Materials Engineering Faculty of Science and TechnologyUniversity of MacaoMacao 999078China Key Lab of Advanced Technologies of Materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China

3D porous iron(Fe)scaffolds with interconnected open pores are promising candidates for bone ***,the bare 3D porous Fe scaffolds lack of antibacterial activity and the ability for cell ***,atomic layer deposition technique was used to deposit nanometer-thick zinc oxide(ZnO)layer onto the skeleton of 3D porous Fe scaffolds with interconnected open *** effect of ZnO thin film on the in vitro degradation behavior,antibacterial activity and cytocompatibility of 3D porous Fe scaffolds was systematically *** results showed that a dense ZnO thin film with a thickness of 76 nm was uniformly deposited on the skeleton of the porous Fe *** thickness of ZnO thin film could be easily controlled by the deposition *** deposited ZnO thin film significantly reduced the degradation rate of porous Fe scaffolds and the fabricated ZnO coated porous Fe scaffolds demonstrated strong antibacterial ability against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus,while did not significantly affect cytocompatibility and could also promote cell adhesion.

关键词： Atomic layer deposition Porous iron scaffolds ZnO Antibacterial activity

Menetrier’s disease and differential diagnosis:A case report

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World Journal of Clinical Cases 2021年第23期9卷 6943-6949页

作者： Hou-Hong Wang can-can zhao Xiao-Lei Wang Ze-Nong Cheng Zong-Yu Xie Department of Surgery The First Affiliated Hospital of Bengbu Medical CollegeBengbu 233004Anhui ProvinceChina Department of Radiology The First Affiliated Hospital of Bengbu Medical CollegeBengbu 233004Anhui ProvinceChina Department of Pathology The First Affiliated Hospital of Bengbu Medical CollegeBengbu 233004Anhui ProvinceChina

BACKGROUND Gastric mucosal hypertrophy,also known as Menetrier's disease(MD),is more common in men over 50 years of age,and the cause is *** symptoms of the disease are atypical,mostly accompanied by hypoproteinemia and edema,and sometimes accompanied by symptoms such as epigastric pain,weight loss,and *** experts believe that the site of the disease is mainly located in the fundus of the stomach and the body of the *** found that the site of the disease in this patient involved the antrum of the *** SUMMARY We introduced the case of a 24-year-old woman who had repeated vomiting for 5 d and was admitted to our *** various examinations such as computed tomography and pathology in our hospital,the final diagnosis of the presented case is *** salient feature is that the mucosal folds in the fundus and body of the stomach are huge and present in the shape of *** greater curvature is more prominent,and there are multiple erosions or ulcers on the *** patient did not undergo gastric surgery and did not undergo *** is drinking Chinese medicine for treatment,and her vomiting and abdominal pain symptoms have *** disease is relatively rare in clinical practice,and it is easy to be misdiagnosed as gastric cancer,chronic gastritis and gastric lymphoma,*** MD can occur in the antrum,it is necessary to raise awareness of the disease and reduce misdiagnosis.

关键词： Gastric mucosa Hypertrophy Menetrier’s disease Helicobacter pylori Case

Malnutrition predicts poor outcomes in diabetic COVID-19 patients in Huangshi,Hubei

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The Journal of Biomedical Research 2022年第1期36卷 42-48页

作者： Jiao Chen can zhao Yingzi Huang Hao Wang Xiang Lu Wei zhao Wei Gao Department of Intensive Care Unit the Affiliated Sir Run Run Hospital of Nanjing Medical UniversityNanjingJiangsu 211100China Department of Geriatrics the Affiliated Sir Run Run Hospital of Nanjing Medical UniversityNanjingJiangsu 211100China Key Laboratory for Aging&Disease Nanjing Medical UniversityNanjingJiangsu 211166China Jiangsu Provincial Key Laboratory of Critical Care Medicine Department of Critical Care MedicineZhongda HospitalSchool of MedicineSoutheast UniversityNanjingJiangsu 210009China.

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection has spread throughout the world,which becomes a global public health *** prolongs its convalescence and has an adverse effect on its prognosis,especially in diabetic *** purpose of this study was to evaluate the prevalence and characteristics of undernourishment and to determine how it is related to the prognostic outcomes in the diabetic patients with coronavirus disease 2019(COVID-19).A retrospective,multicenter study was conducted in 85 diabetic COVID-19 patients from three hospitals in Hubei *** patients were assessed using the European Nutritional Risk Screening 2002(NRS-2002)and other nutritional assessments when *** them,35(41.18%)were at risk of malnutrition(NRS score≥3).Severe COVID-19 patients had a significantly lower level of serum albumin and prealbumin and higher NRS score than non-severe *** logistic regression analysis showed that serum prealbumin and NRS score increased the likelihood of progression into severe status(P<0.05).Meanwhile,single factor and multivariate analysis determined that grade of illness severity was an independent predictor for ***,prealbumin and NRS score could well predict severe status for COVID-19 *** malnutrition group(NRS score≥3)had more severe illness than the normal nutritional(NRS score<3)group(P<0.001),and had a longer length of in-hospital stay and higher *** is highly prevalent among COVID-19 patients with *** is associated with severely ill status and poor *** of nutritional status should be strengthened,especially the indicators of NRS-2002 and the level of serum prealbumin.

关键词： NRS-2002 malnutrition COVID-19 diabetes

Design, synthesis and systematic evaluation of all possible cyclic dinucleotides (CDNs) that activate human stimulator of interferon genes (STING) variants

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Science China Chemistry 2020年第4期63卷 534-545页

作者： Zheng-Hua Wang can-can zhao Qiang-Zhe Zhang Chuan-Lin Wang Hang Zhang De-Jun Ma Da-Wei Wang Xin Wen Lu-Yuan Li Zhen Xi State Key Laboratory of Elemento-organic Chemistry Department of Chemical BiologyCollege of ChemistryNankai UniversityTianjin 300071China State Key Laboratory of Medicinal Chemical Biology and College of Pharmacy Tianjin Key Laboratory of Molecular Drug ResearchNankai UniversityTianjin 300071China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) Tianjin 300071China National Pesticide Engineering Research Center(Tianjin) Tianjin 300071China

Cyclic dinucleotides(CDNs) are known to activate stimulator of interferon genes(STING) and induce type I interferon responses, therefor possess great potentials to be of immunotherapeutic value for cancers and infectious diseases. However, the existence of different single nucleotide polymorphism(SNP) of human STING(hSTING) gene poses an obstacle to achieve broad-spectrum activation by CDNs. We reported here the design and synthesis of a total of 36 CDNs, representing all structural variations, that contain four bases(A, G, C, U) and two linkage directions(2′-5′-linked and 3′-5′-linked phosphodiester).Through systematic evaluation of IFN-β induction with a dual-luciferase reporter assay, we discovered that wild type hSTING and two isoforms(HAQ and AQ) showed strong response while hSTING-R232 H and R293 Q exhibited the relatively weak response to CDNs stimulation. For the first time, we found that the c[G(2′,5′)U(2′,5′)] showed excellent activity against all five hSTING variants even equivalent to the endogenous ligand c[G(2′,5′)A(3′,5′)]. Furthermore, we have also demonstrated that 3′-3′CDNs with two 3′-5′ phosphodiesters showed higher serum and hydrolase stability than 2′-2′ CDNs with two 2′-5′ phosphodiesters and 2′-3′ CDNs with one 2′-5′ and one 3′-5′ phosphodiester. It is very interesting to note that 2′-2′ CDNs has been found for the first time to show strong activity. These findings will stimulate our exploration for the new functional role of CDNs, and provide guidelines to design CDNs based hSTING targeted drugs.

关键词： cyclic dinucleotides(CDNs) stimulator of interferon genes(STING) pyrimidine CDNs interferonβ ecto-nucleotide pyrophosphatase/phosphodiesterase 1(ENPP1)

Seismic Data Recovery with Curvelet Bivariate Shrinkage Function Based on Compressed Sensing

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Journal of Harbin Institute of Technology(New Series) 2018年第5期25卷 86-96页

作者： Yah Zhang Weijian Ren Guowei Tang can zhao School of Computer and Information Technology Northeast Petroleum University Daqing 163318 Heilongfiang China School of Electrical Engineering and Information Northeast Petroleum University Daqing 163318 Heilongfiang China

Recovery of under-sampled seismic data is a critical problem,in oil and gas exploration,therefore recovery algorithms with iterative shrinkage based on compressed sensing have been recently proposed. However most of these algorithms usually adopt a soft shrinkage function,which assumes that all of the sparse coefficients are independent of each other in curvelet or other domains,little attention has so far been devoted to the inter-dependencies of coefficients. In this paper,the dependencies of parent-child curvelet coefficients of seismic data are exploited by Bayesian estimation,moreover the new seismic data recovery algorithm via curvelet-based bivariate shrinkage function is proposed. First the respective parent-child curvelet coefficients joint distribution models of fully-sampled seismic data and noise signal caused by missing traces are established,then the bivariate shrinkage function according to the Bayesian maximum posterior probability estimation is obtained,finally the Landweber iterative shrinkage algorithm is used in the recovery *** compared with existing recovery algorithms,it is proved that the proposed algorithm can obtain higher PSNR performance,and maintains the texture details better in events of seismic data

关键词： Seismic data recovery compressed sensing iterative shrinkage bivariate shrinkage function

On the statistical significance of protein complex

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Frontiers of Electrical and Electronic Engineering in China 2018年第4期6卷 313-320页

作者： Youfu Su can zhao Zheng Chen Bo Tian Zengyou He School of Software Dalian University of TechnologyDalian 116024China Key Laboratory for Ubiquitous Network and Service Software of Liaoning Dalian 116024China

Background Statistical validation of predicted complexes is a fundamental issue in proteomics and bioinformatics. The target is to measure the statistical significance of each predicted complex in terms of p-values. Surprisingly, this issue has not received much attention in the literature. To our knowledge, only a few research efforts have been made towards this *** In this article, we propose a novel method for calculating the p-value of a predicted complex. The null hypothesis is that there is no difference between the number of edges in target protein complex and that in the random null model. In addition, we assume that a true protein complex must be a connected subgraph. Based on this null hypothesis, we present an algorithm to compute the p-value of a given predicted *** We test our method on five benchmark data sets to evaluate its *** The experimental results show that our method is superior to the state-of-the-art algorithms on assessing the statistical significance of candidate protein complexes.

关键词： predicted complex statistical significance testing subgraph mining community detection