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Diameter-dependent in vitro performance of biodegradable pure zinc wires for suture application

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Journal of Materials Science & Technology 2019年第8期35卷 1662-1670页

作者： H. Guo R.H. Cao Y.F. Zheng J. Bai F. Xue C.L. Chu State Key Laboratory for Turbulence and Complex system and department of Materials Science and Engineering College of Engineering Peking University Beijing 100871 China School of Materials Science and Engineering Southeast University Nanjing 211189 China Key Laboratory for Advanced Metallic Materials Southeast University Nanjing 211189 China

In this study, biodegradable pure zinc wires with 3.0 mm and 0.3 mm in diameter were prepared via hot-extrusion and subsequent cold-drawing process respectively. The microstructure, mechanical performance, corrosion behavior, in vitro cytocompatibility and antibacterial effect were comparatively *** cold-drawing, the mechanical property, especially the elongation of the ф0.3 mm pure Zn wire was improved significantly compared with the ф3.0 mm pure Zn wire. The in vitro corrosion study including immersion and electrochemical test showed acceptable corrosion resistance of these two materials in Hank's solution. The in vitro Human Umbilical Vein Endothelial Cells(HUVECs) viability assay showed obviously different results, in which the ф0.3 mm pure Zn wire demonstrated favorable cytocompatibility, while the ф3.0 mm wire exhibited severe cytotoxic effect with 100% extract concentration. Both of them exhibited partly antibacterial effect on S. aureus. These results demonstrated the feasibility of the prepared 0.3 mm pure Zn wire as the potential suture material with good absorbability.

关键词： Pure zinc Wire Biodegradable metal Suture

Novel therapy for non-cirrhotic hyperammonemia due to a spontaneous splenorenal shunt

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World Journal of Gastroenterology 2014年第25期20卷 8288-8291页

作者： Shari S Rogal Angela Hu Rupal Bi Obaid Shaikh Division of Gastroenterology Hepatology and Nutrition University of Pittsburgh Medical Center Pittsburgh PA 15213 United States University of Pittsburgh School of Medicine Pitts-burgh PA 15213 United States department of Radiology Veterans Affairs Pitts-burgh Healthcare System Pittsburgh PA 15240 United States Division of Gastroenterology Veterans Affairs Pittsburgh Healthcare System Pittsburgh PA 15240 United States

Spontaneous splenorenal shunts in the absence of cirrhosis have rarely been reported as a cause hyperammonemia with encephalopathy. Several closure techniques of such lesions have been described. Here we report a case of a patient with no history of liver disease who developed significant confusion. After an extensive workup, he was found to have hyperammonemia and encephalopathy due to formation of a spontaneous splenorenal shunt. There was no evidence of cirrhosis on biopsy or imaging and no portal hypertension when directly measured. The shunt was 18 mm and too large for embolization so the segment of the splenic vein between the portal vein and the shunt was occluded using an Amplatzer plug. Thus, the superior mesenteric flow was directed entirely to the liver. After interventional radiology closure of the shunt using this technique there was complete resolution of *** case represents the first report of a successful closure of splenorenal shunt via percutaneous embolization of the splenic vein with an amplatzer plug using a common femoral vein approach.

关键词： Splenorenal shunt Gastric bypass Hyperammonemia Encephalopathy

Improving sludge dewaterability via Fe^(2+) chelated citrate activated peroxydisulfate oxidation

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Journal of Environmental Sciences 2023年第3期125卷 223-233页

作者： Donghai Yuan Xinyu Li Siyu Xiong Jun Cui Jijiao Zhou Yingying Kou Key Laboratory of Urban Stormwater system and Water Environment Ministry of EducationBeijing University of Civil Engineering and ArchitectureBeijing 100044China department of Environmental Science and Engineering Beijing University of Chemical TechnologyBeijing 100029China Huzhou Environmental Sanitation Management Center Huzhou 313000China

Citrate (Ct) was chosen as a typical chelator used in the Fe^(2+)-peroxydisulfate (PDS) process to improve sludge *** PDS-Fe^(2+)-Ct process exhibited better performance in sludge dewatering than PDS-Fe^(2+).Specifically,with a PDS dosage of 1.2 mmol/g VS,the molar ratio of PDS/Fe^(2+)and Ct/Fe^(2+)were 4:5 and 1:4,respectively,the capillary suction time decreased from 155.8 to 24.8sec,and the sludge cake water content decreased from 82.62%to 64.11%(-0.06MPa).The oxidation led to a reduced negative charge and a decrease in particle *** enhanced sludge dewaterability and changes of sludge properties were attributed to the decomposition of extracellular polymeric substances,and it was explored by protein,polysaccharide,3D-EEMs,and ***,the quenching experiments of radical species demonstrated that SO_(4)-·played a more important role than·OH,and its productivity was improved with the addition of ***,the reasons for the improved productivity of radicals with the addition of Ct were *** results of this study could serve as a basis for improving sludge dewatering using the PDS-Fe^(2+)-Ct process and suggest that the addition of Ct may improve the productivity of SO_(4)-·in the activation o PDS via Fe^(2+).

关键词： Wastewater sludge Dewaterability Peroxydisulfate oxidation Citrate

Wetting behavior and interfacial characteristic of Sn-Ag-Cu solder alloy on Cu substrate

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Chinese Science Bulletin 2010年第9期55卷 797-801页

作者： ZHANG XiaoRui YUAN ZhangFu ZHAO HongXin ZANG LiKun LI JianQiang department of Energy&Resources Engineering College of EngineeringPeking UniversityBeijing 100871China State Key Laboratory of Multiphase Complex system Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China

Wettability of molten Sn-Ag-Cu alloy on Cu substrate has been determined by sessile drop method, as well as its dependence on time and temperature. It was found that the evolution of contact angle at the alloy’s melting point experienced four different stages. Especially, the contact angle was unstable and fluctuant in stage II, and gradually decreased in stage III mainly due to a chemical reaction between Sn-Ag-Cu alloy and Cu substrate. The contact angle decreased with increasing temperature, but increased slightly at 629 K, for another chemical reaction occurred. Interfacial characteristic has been further investigated by examining the sample’s cross section. Intermetallic compounds of Cu6Sn5 and β-Sn phase were found at the interface of Sn-Ag-Cu/Cu.

关键词： contact angle lead-free solder sessile drop method Sn-Ag-Cu intermetallic compounds

Analytical Representation of Data-driven Transient Stability Constraint and Its Application in Preventive Control

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Journal of Modern Power systems and Clean Energy 2022年第5期10卷 1085-1097页

作者： Yiwei Fu Xiaohua Zhang Lei Chen Zengyao Tian Kaiyuan Hou Haikuan Wang State Key Laboratory of Control and Simulation of Power system and Generation Equipment Department of Electrical EngineeringTsinghua UniversityBeijing 100084China State Grid Jibei Electric Power Company Beijing 100053China Northeast China Branch of State Grid Corporation of China Shenyang 110180China

Accurate transient stability assessment(TSA) and effective preventive control are important for the stable operation of power systems. With the superiorities in precision and efficiency, data-driven methods are widely used in TSA nowadays. Data-driven TSA model can be adopted in the stability constraints of preventive control optimization, but existing methods are mostly iteration-based ones, which may result in low efficiency, sometimes even non-convergence. In this paper,an analytical representation method of data-driven transient stability constraint is proposed based on a non-parametric regression model built for TSA. Key feature extraction and dominant sample selection are proposed to reduce the scale of the TSA model, and bi-level linearization is applied to further modify *** preventive control model is then formulated as a mixed-integer linear program(MILP) problem with the linearized analytical data-driven transient stability constraint, which can be solved without iterations. An overall procedure of datadriven TSA and preventive control is finally developed. Case studies show that the proposed method has high accuracy in TSA and can achieve effective preventive control of power system with high efficiency.

关键词： Data-driven critical clearing time transient stability constraint non-parametric regression optimal preventive control

RLC Equivalent Circuit Synthesis Method for Structure-Preserved Reduced-Order Model of Interconnect in VLSI

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Communications in Computational Physics 2008年第2期3卷 376-396页

作者： Fan Yang Xuan Zeng Yangfeng Su Dian Zhou State Key Lab.of ASIC&system Microelectronics DepartmentFudan UniversityZhangheng Road 825Shanghai 201203China Mathematicsdepartment FudanUniversityHanDan Road 220Shanghai 200433China E.E.department University of Texas at DallasRichardsonTX 75080USA.

This paper aims to explore RLC equivalent circuit synthesis method forreduced-order models of interconnect circuits obtained by Krylov subspace basedmodel order reduction (MOR) methods. To guarantee pure RLC equivalent circuitscan be synthesized, both the structures of input and output incidence matrices and theblock structure of the circuit matrices should be preserved in the reduced-order *** structure preserving MOR methods have been well established. In this paper,we propose an embeddable Input-Output structure Preserving Order Reduction(IOPOR) technique to further preserve the structures of input and output incidencematrices. By combining block structure preserving MOR methods and IOPOR technique,we develop an RLC equivalent circuit synthesis method RLCSYN (RLC SYNthesis).Inline diagonalization and regularization techniques are specifically proposedto enhance the robustness of inductance synthesis. The pure RLC model, high modelingaccuracy, passivity guaranteed property and SPICE simulation robustness makeRLCSYN more applicable in interconnect analysis, either for digital IC design ormixedsignal IC simulation.

关键词： Interconnect circuit model order reduction equivalent circuit synthesis.

Long-term prognosis in patients with severe late radiation enteropathy:A prospective cohort study

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World Journal of Gastroenterology 2007年第26期13卷 3610-3613页

作者： Annette Larsen Jon B Reitan Steinar T Aase Martin Hauer-Jensen Institute of Internal Medicine Department of OncologyHaukeland University Hospital N-5021 BergenNorway department of Oncology The Norwegian Radium Hospital N-0310 OsloNorway department of Pathology Haukeland University Hospital N-5021 BergenNorway departments of Surgery and Pathology University of Arkansas for Medical SciencesCentral Arkansas Veterans Healthcare SystemLittle RockArkansasUnited States

AIM: To assess persistent symptoms and mortality in a cohort of patients with severe (grade 3-4) radiation enteropathy,59 patients were followed up after 15-18 years. METHODS: Fifty-nine patients were prospectively enrolled by twelve surgical departments. Primary malignant disease,radiation therapy and surgical management were recorded at inclusion. The cause of death or persistence of symptoms was examined in public death records or by interview of survivors. RESULTS: Thirty-nine patients had received radiation therapy for gynaecological cancers,twelve for urological cancers,four for gastrointestinal cancers and four for other malignancies. Forty-five patients (76%) required surgical intervention. Complications occurred in 11 (25%) operated patients. Forty-seven patients had died at the time of follow-up,seven (12%) died as a direct result of radiation enteropathy,while radiation enteropathy contributed to death in an additional seven patients. Four of the twelve surviving patients suffered from chronic debilitating symptoms of radiation enteropathy,while three had moderate symptoms. CONCLUSION: Patients with severe delayed radiation enteropathy have a high risk of persistence of symptoms after surgery. At least one in ten patients dies from radiation-induced bowel injury.

关键词： Radiation enteropathy Long-term follow up

Security Issues and Defensive Approaches in Deep Learning Frameworks

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Tsinghua Science and Technology 2021年第6期26卷 894-905页

作者： Hongsong Chen Yongpeng Zhang Yongrui Cao Jing Xie department of Computer Science University of Science and Technology Beijing(USTB)Beijing 100083China Beijing Key Laboratory of Knowledge Engineering for Materials Science Beijing 100083China department of Computer Science and Technology University of Science and Technology Beijing(USTB)Beijing 100083China Defense Electronics Institute China Industrial Control System Cyber Emergency Response TeamBeijing 100040China

Deep learning frameworks promote the development of artificial intelligence and demonstrate considerable potential in numerous ***,the security issues of deep learning frameworks are among the main risks preventing the wide application of *** on deep learning frameworks by malicious internal or external attackers would exert substantial effects on society and *** start with a description of the framework of deep learning algorithms and a detailed analysis of attacks and vulnerabilities in *** propose a highly comprehensive classification approach for security issues and defensive approaches in deep learning frameworks and connect different attacks to corresponding defensive ***,we analyze a case of the physical-world use of deep learning security *** addition,we discuss future directions and open issues in deep learning *** hope that our research will inspire future developments and draw attention from academic and industrial domains to the security of deep learning frameworks.

关键词： adversarial examples deep learning frameworks defensive approaches security issues

Data-driven Predictive Control for the Industrial Processes with Multiphase and Transition 25th

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Data-driven Predictive Control for the Industrial Processes ...