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An SIS Epidemic Model with Stage Structure and a Delay

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Acta Mathematicae Applicatae Sinica 2002年第4期18卷 607-618页

作者： yan-ni Xiao, Lan-sun ChenAcademy of Mathematics and System Sciences, Chinese Academy of Sciences. Beijing 100080. China Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing China

A disease transmission model of SIS type with stage structure and a delay is formulated. Stability of the disease free equilibrium, and existence, uniqueness, and stability of an endemic equilibrium, are investigated for the model. The stability results arc stated in terms of a key threshold parameter. The effects of stage structure and time delay on dynamical behavior of the infectious disease are analyzed. It is shown that stage structure has no effect on the epidemic model and Hopf bifurcation can occur as the time delay increases.

关键词： SIS epidemic model threshold globally asymptotically stable hopf bifurcation stage structure

Papillary Glioneuronal Tumor with an Excessive Angiomatous Component in an Elderly Man

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Chinese Medical Journal 2018年第2期131卷 243-244页

作者： Dan-Dan Wang Yue-Shan Piao Ingmar Blumcke yan-ni sun Wei Gao Li-Hong Zhao Wei-Min Wang De-Hong Lu Department of Pathology Xuanwu Hospital Capital Medical University Beijing 100053 China Neuropathological Institute University Hospital Erlangen Edangen Germany

Papillary glioneuronal tumor （PGNT） is a rare tumor categorized as a distinct mixed glioneuronal neoplasm in the World Health Organization （WHO） 2007 classification,rfl Here, we report a case of PGNT accompanied by excessive areas with angioma-like features in an elderly man. This report contributes to the diverse spectrum of this rare tumor entity.

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Rational surface charge engineering of haloalkane dehalogenase for boosting the enzymatic performance in organic solvent solutions

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Chinese Journal of Chemical Engineering 2024年第1期65卷 276-285页

作者： Yin Wu yan sun Department of Biochemical Engineering School of Chemical Engineering and Technology and Key Laboratory of Systems Bioengineering and Frontiers Science Center for Synthetic Biology(Ministry of Education)Tianjin UniversityTianjin 300350China

Biocatalysis in organic solvents(OSs)has numerous important applications,but native enzymes in OSs often exhibit limited catalytic ***,we proposed a computation-aided surface charge engineering strategy to improve the catalytic performance of haloalkane dehalogenase DhaA in OSs based on the energetic analysis of substrate binding to the DhaA *** variants with enhanced OS resistance were obtained by replacing negative charged residues on the surface with positive charged residue(Arg).Particularly,a four-substitution variant E16R/E93R/E121R/E257R exhibited the best catalytic performance(five-fold improvement in OS resistance and seven-fold half-life increase in 40%(vol)dimethylsulfoxide).As a result,the overall catalytic performance of the variant could be at least 26 times higher than the wild-type *** spectroscopy and molecular dynamics simulation studies revealed that the residue substitution mainly enhanced OS resistance from four aspects:(a)improved the overall structural stability,(b)increased the hydrophobicity of the local microenvironment around the catalytic triad,(c)enriched the hydrophobic substrate around the enzyme molecule,and(d)lowered the contact frequency between OS molecules and the catalytic *** findings validate that computationaided surface charge engineering is an effective and ingenious rational strategy for tailoring enzyme performance in OSs.

关键词： Surface charge engineering Organic solvent resistance Molecular dynamics simulation Haloalkane dehalogenase

Computerized cognitive remediation therapy on cognitive impairment and social function in patients with chronic schizophrenia

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World Journal of Psychiatry 2024年第6期14卷 884-893页

作者： Jian-Jun Hu Xi-Rong sun Shuang-Ming ni yan Kong Department of Psychiatry Shanghai Pudong New Area Mental Health Center(Mental Health Center of Tongji UniversityShanghai Pudong New Area Psychological Counseling Center)Shanghai 200124China

BACKGROUND Patients with schizophrenia may have various disease manifestations,most of which gradually tend toward incurable chronic decline,leading to mental *** basic symptoms of the disease can impair social function,whereas long-term hospitalization produces hospitalization syndrome,causing serious damage to social *** To investigate the effects of Computerized Cognitive Remediation Therapy(CCRT)on cognitive and social functioning in patients with chronic *** A retrospective analysis of 120 patients with chronic schizophrenia in Shanghai Pudong New Area Mental Health Center was *** were divided into an intervention group(60 cases treated with CCRT combined with conventional medication)and a control group(60 cases treated with conventional medication).After treatment,effects on cognitive function and social roles were observed in both *** Positive and Negative Syndrome Scale(PANSS)was used to assess the patients'psychiatric *** Wisconsin Card Sorting Test(WCST)was used to assess the patients'cognitive functioning,and the Social Functioning Scale for Psychiatric Inpatients(SSPI)was used to assess the social functioning of the inpatient psychiatric *** No significant differences were observed in the PANSS,WCST,and SSPI intergroup scores before treatment(P>0.05).After 2,4,and 6 wk of therapy,general psychopathological factors,positive symptoms,negative symptoms,and total PANSS scores of PANSS in the intervention group were lower than in the control group(Pnificantly lower in the intervention group than in the control group(Pnificantly higher than in the control group(Pnificantly greater than those of the controls(P<0.05).After 6 wk of treatm

关键词： Computerized cognitive correction therapy Schizophrenia Cognitive function Social function Psychopathological factors

Towards Data-Driving Multi-View Evaluation Framework for Scratch

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Tsinghua Science and Technology 2024年第2期29卷 517-528页

作者： Xiaolin Chai yan sun yan Gao Department of Computer Science Beijing University of Posts and TelecommunicationBeijing 100876China Intellectual Property Institute Shandong Polytechnic CollegeJining 272067China

As one of the most popular visual programming languages,Scratch has a lot of evaluation around *** evaluation can help programmers understand their projects *** the same time,it can also provide a reference for them to browse other projects in the online *** of the existing evaluations on Scratch are carried from three perspectives:Computational Thinking(CT)ability,visual presentation aesthetics,and code *** them,the assessment of CT and code quality is mainly carried out from the program script,while the evaluation of visual aesthetics is analyzed from the perspective of image sequences generated by project *** single-view evaluation focuses on the performance of a program in a certain aspect and is *** this paper,we propose a multi-view evaluation framework to integrate various evaluations using different *** quantitatively analyze the assessment of different views driven by *** with overall evaluations that represent human opinions,we analyze their differences and *** experiments,we determine the weights of different integration policies,the proposed multi-view evaluation method can generate evaluation results similar to human opinions.

关键词： Scratch Computational Thinking(CT) visual aesthetic static analysis integration policy machine learning

Benign giant-cell tumor of the common bile duct:A case report

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World Journal of Gastroenterology 2014年第41期20卷 15448-15453页

作者： Dan-Dan Wang Ya-Min Zheng Liang-Hong Teng yan-ni sun Wei Gao Lei-Ming Wang Yue-Hua Wang Fei Li De-Hong Lu Department of Pathology Xuanwu Hospital Capital Medical University Department of General Surgery Xuanwu Hospital Capital Medical University

Primary giant-cell tumors rarely arise in the common bile duct. We herein report a case of primary giant-cell tumor of the common bile duct. The patient was an 81-year-old male who was diagnosed with a well-defined 1.2-cm mass projecting into the lumen of the middle common bile duct. Excision of the gallbladder and extrahepatic bile duct and a Roux-en-Y cholangiojejunostomy were performed. Histologically, the tumor had no association with carcinomas of epithelial origin and was similar to giant-cell tumors of the bone. The tumor consisted of a mixture of mononuclear and multinucleated osteoclast-like giant cells. The mononuclear cells showed no atypical features, and their nuclei were similar to those of the multinucleated giant cells. CD68 was expressed on the mononuclear and multinucleated osteoclast-like giant cells, whereas CD163 immunoreactivity was restricted to the mononuclear cells. Six months after the operation, the patient was still alive and had no recurrence. The interest of this case lies in the rarity of this entity, the difficulty of preoperative diagnosis, and this tumor’s possible confusion with other malignant tumors.

关键词： Giant-cell tumor Common bile duct CD163 Surgical resection

Effects of different concentrations of nicotinamide on hematopoietic stem cells cultured in vitro

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World Journal of Stem Cells 2024年第2期16卷 163-175页

作者： yan Ren yan-ni Cui Hong-Wei Wang The Second Clinical Medical College Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Department of Hematology The Second Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Department of Hematology Key Laboratory of Molecular Diagnosis and Treatment of Blood Diseases in Shanxi ProvinceTaiyuan 030001Shanxi ProvinceChina

BACKGROUND In vitro expansion to increase numbers of hematopoietic stem cells(HSCs)in cord blood could improve clinical efficacy of this vital ***(NAM)can promote HSC expansion ex vivo,but its effect on hematopoietic stem and progenitor cells(HSPCs,CD34^(+)CD38)and functional subtypes of HSCs-shortterm repopulating HSCs(ST-HSCs,CD34^(+)CD38CD45RACD49f^(+))and long-term repopulating HSCs(LT-HSCs,CD34^(+)CD38CD45RACD49f^(+)CD90^(+))is not yet *** a sirtuin 1(SIRT1)inhibitor,NAM participates in regulating cell adhesion,polarity,migration,proliferation,and ***,SIRT1 exhibits dual effects by promoting or inhibiting differentiation in different tissues or *** propose that the concentration of NAM may influence proliferation,differentiation,and SIRT1 signaling of *** To evaluate the effects and underlying mechanisms of action of different concentrations of NAM on HSC proliferation and *** CD34^(+)cells were purified from umbilical cord blood using MacsCD34 beads,and cultured for 10-12 d in a serum-free medium supplemented with cytokines,with different concentrations of NAM added according to experimental *** cytometry was used to detect phenotype,cell cycle distribution,and apoptosis of the cultured ***-time polymerase chain reaction was used to detect the transcription levels of target genes encoding stemness-related factors,che mokines,components of hypoxia pathways,and antioxidant ***-dihydro-fluorescein diacetate probes were used to evaluate intracellular production of reactive oxygen species(ROS).Determination of the effect of different culture conditions on the balance of cytokine by cytometric bead *** Compared with the control group,the proportion and expansion folds of HSPCs(CD34^(+)CD38)incubated with 5 mmol/L or 10 mmol/L NAM were significantly increased(all Pnificantly

关键词： Hematopoietic stem cells nicotinamide Concentration Proliferation Differentiation Sirtuin 1

Particles attrition of binary mixtures in the coal-fueled chemical looping system based on fluidized bed

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Particuology 2024年第3期86卷 281-290页

作者： Heyu Li Zhe sun yan Cao Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640China University of Chinese Academy of Sciences Bejing 100049China CAS Key Laboratory of Renewable Energy Guangzhou 510640China Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development Guangzhou 510640China College of Chemistry and Chemical Engineering Anhui UniversityHefei230601China

In this work,a reactive air jet attrition device with auto-recording and collection of elutriated fines was *** established insights into the physiochemical interaction and further correlated attrition behaviors between char and oxygen carriers under various operation *** attrition rate increased by over 110% upon the introduced CO_(2),which brought in the significant effect of thermo-chemical stress,similarly in effects of the increased char addition ratio and the decreased sizes of char or hematite in different *** the char-hematite co-attrition process,the elutriated carbon loss of char with poor mechanical strength was found to be over 10%,while the reactive iron loss of hematite was found to be 6.3%,and was enriched in elutriated *** reaction-derived thermochemical stress and the collision-derived mechanical stress jointly controls the particle attrition during the cyclic transformation of oxygen carrier particles in coal-fueled chemical looping fluidization,especially sig-nificant in its reduction stage.

关键词： Attrition Binary species Chemical looping Oxygen carrier CO_(2)capture

Therapeutic Effect of Rhodopseudomonas palustris-Bioconverted Extract of Lycium barbarum on Rats with Lead Exposure

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Biomedical and Environmental Sciences 2024年第4期37卷 440-444页

作者： yanG Hong sun Yi CHAI Shu Tong LIANG yan Hui LIU Ya ni yanG Guan E School of Pharmacy Shanxi Medical UniversityTaiyuan 030001ShanxiChina

Lead is a ubiquitous pollutant and Pb pollution is a global public health *** has been reported to induce multiple adverse effects,including reproductive toxicity,neurotoxicity,carcinogenicity,nephrotoxicity,immunotoxicity,and hypertension[1].The traditional medical treatment available for Pb poisoning is chelation,which can save lives in individuals with very high blood Pb *** commonly used chelating agents include CaNa2EDTA and meso-2,3-dimercaptosuccinic ***,chelation therapy has strong short-term effects on the overall long-term management of Pb exposure.

关键词： converted chelation chelating