检索结果-南通市图书馆

Highly Hydrolysis-Resistant Polyimide Fibers Prepared by Thermal Crosslinking with Inherent Carboxyl Groups

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第2期42卷 247-255,I0010页

作者： can-can Zhang Jun-Long Yang Ya-Jiang huang Guang-Xian li College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering of ChinaSichuan UniversityChengdu610065China

Easy hydrolysis in alkaline environments limits the use of polyimide fibers in environmental protection. The hydrolysis resistance levels of polyimide fibers can be improved by crosslinking of the macromolecular chains. In this work, crosslinked polyimide fibers(CPI fibers) were produced by intrinsic carboxyl decarboxylation for the first time. The thermal stability of the polyimide fibers containing the intrinsic carboxyl groups(PIC fibers) was studied, and the temperature of the decarboxylation-crosslinking reaction was determined to be 450 ℃. The PIC fibers were hotdrawn to initiate thermal crosslinking of the carboxyl groups and molecular chain orientation at high temperature. The CPI fibers had high tensile strengths(0.72-1.46 GPa) and compressive strengths(401-604 MPa). The oriented macromolecules and chemically crosslinked structure improved the tightness of the molecular chains and endowed the CPI fibers with excellent hydrolytic resistance. The CPI-50 fiber did not dissolve in a 0.5 wt% NaOH solution during heating at 90 ℃ for 10 h, and the tensile strength retention reached 87% when treated in 0.5 wt% NaOH solutions at 90 ℃ for 1 h, providing a guarantee for its application in alkaline corrosive environments.

关键词： Polyimide Carboxyl group Crosslinking Hydrolysis-resistance

Application of Global Leadership Initiative on Malnutrition criteria in patients with liver cirrhosis

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2024年第1期137卷 97-104页

作者： Minjie Jiang Juan Chen Muchen Wu Jing Wu Xiaotong Xu Juan li can liu Yaping Zhao Xin hua Qinghua Meng Department of Hepatology Beijing You-An HospitalCapital Medical UniversityBeijing 100069China Beijing Institute of Hepatology Beijing 100069China Department of Medical Oncology Beijing You-An HospitalCapital Medical UniversityBeijing 100069China Department of Nutrition Beijing You-An HospitalCapital Medical UniversityBeijing 100069China

Background:The Global Leadership Initiative on Malnutrition(GliM)criteria were published to build a global consensus on nutritional diagnosis.Reduced muscle mass is a phenotypic criterion with strong evidence to support its inclusion in the GliM consensus criteria.However,there is no consensus regarding how to accurately measure and define reduced muscle mass in clinical settings.This study aimed to investigate the optimal reference values of skeletal muscle mass index for diagnosing sarcopenia and GliM-defined malnutrition,as well as the prevalence of GliM-defined malnutrition in hospitalized cirrhotic patients.Methods:This retrospective study was conducted on 1002 adult patients with liver cirrhosis between January 1,2018,and February 28,2022,at Beijing You-An Hospital,Capital Medical University.Adult patients with a clinical diagnosis of liver cirrhosis and who underwent an abdominal computed tomography(CT)examination during hospitalization were included in the study.These patients were randomly divided into a modeling group(cohort 1,667 patients)and a validation group(cohort 2,335 patients).In cohort 1,optimal cut-off values of skeletal muscle index at the third lumbar skeletal muscle index(L3-SMI)were determined using receiver operating characteristic analyses against in-hospital mortality in different gender groups.Next,patients in cohort 2 were screened for nutritional risk using the Nutritional Risk Screening 2002(NRS-2002),and malnutrition was diagnosed by GliM criteria.Additionally,the reference values of reduced muscle mass in GliM criteria were derived from the L3-SMI values from cohort 1.Multivariate logistic regression analysis was used to analyze the association between GliM-defined malnutrition and clinical outcomes.Results:The optimal cut-off values of L3-SMI were 39.50 cm 2/m 2 for male patients and 33.06 cm 2/m 2 for female patients.Based on the cut-off values,31.63%(68/215)of the male patients and 23.3%(28/120)of the female patients had CT-determined sarcopenia in cohort 2.The prevalence of GL

关键词： Malnutrition liver cirrhosis Sarcopenia Clinical outcomes GliM criteria

Breaking the efficiency limitations of dissipative Kerr solitons using nonlinear couplers

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 88-94页

作者： Ming li Xiao-Xiao Xue Yan-Lei Zhang Xin-Biao Xu Chun-hua Dong Guang-can Guo Chang-ling Zou CAS Key Laboratory of Quantum Information University of Science and Technology of ChinaHefei 230026China CAS Centerfor Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China Department of Electronic Engineering Beijing National Research Center for Information Science and TechnologyTsinghua University Beijing 100084China

Dissipative Kerr solitons(DKS) have long been suffering from poor power conversion efficiency when driven by continuous-wave lasers. By deriving the critical coupling condition of a multimode nonlinear optics system in a generalized theoretical framework,two efficiency limitations of the conventional pump method of DKS are revealed: the effective coupling rate is too small and is also power-dependent. A general approach is provided to resolve this challenge by introducing two types of nonlinear couplers to couple the soliton cavity and CW input through nonlinear processes. The collective coupler opens multiple coupling channels and the self-adaptive coupler builds a power-independent effective external coupling rate to the DKS for approaching the generalized critical coupling condition, which promises near-unity power conversion efficiencies. For instance, a conversion efficiency exceeding 90% is predicted for aluminum nitride microrings with a nonlinear coupler utilizing second-harmonic generation. The mechanism applies to various nonlinear processes, including Raman and Brillouin scattering, and thus paves the way for micro-solitons toward practical applications.

关键词： Kerr frequency comb conversion efficiency nonlinear coupler

Severe pediatric COVID‑19:a review from the clinical and immunopathophysiological perspectives

在线全文

学校读者我要写书评

暂无评论

World Journal of Pediatrics 2024年第4期20卷 307-324页

作者： Yi‑Kan Sun can Wang Pei‑Quan lin Lei Hu Jing Ye Zhi‑Gang Gao Ru lin Hao‑Min li Qiang Shu li‑Su huang lin‑hua Tan Children's Hospital Zhejiang University School f MedicineHangzhou 310052China The Second Affiliated Hospital Zhejiang University School of MedicineHangzhou 310030China Surgical Intensive Care Unit Children’s HospitalZhejiang University School of MedicineHangzhou 310052China Department of General Surgery Children’s HospitalZhejiang University School of MedicineHangzhou 310052China Department of Cardiopulmonary and Extracorporeal life Support Children’s HospitalZhejiang University School of MedicineHangzhou 310052China Clinical Data Center Children’s HospitalZhejiang University School of MedicineHangzhou 310052China Department of Cardiac Surgery Children’s HospitalZhejiang University School of MedicineHangzhou 310052China National Clinical Research Center for Child Health Children’s HospitalZhejiang University School of MedicineHangzhou 310052China Department of Infectious Diseases Children’s HospitalZhejiang University School of MedicineHangzhou 310052China

Background Coronavirus disease 2019(COVID-19)tends to have mild presentations in children.However,severe and critical cases do arise in the pediatric population with debilitating systemic impacts and can be fatal at times,meriting further attention from clinicians.Meanwhile,the intricate interactions between the pathogen virulence factors and host defense mechanisms are believed to play indispensable roles in severe COVID-19 pathophysiology but remain incompletely understood.Data sources A comprehensive literature review was conducted for pertinent publications by reviewers independently using the PubMed,Embase,and Wanfang databases.Searched keywords included“COVID-19 in children”,“severe pediatric COVID-19”,and“critical illness in children with COVID-19”.Results Risks of developing severe COVID-19 in children escalate with increasing numbers of co-morbidities and an unvaccinated status.Acute respiratory distress stress and necrotizing pneumonia are prominent pulmonary manifestations,while various forms of cardiovascular and neurological involvement may also be seen.Multiple immunological processes are implicated in the host response to COVID-19 including the type I interferon and inflammasome pathways,whose dysregulation in severe and critical diseases translates into adverse clinical manifestations.Multisystem inflammatory syndrome in children(MIS-C),a potentially life-threatening immune-mediated condition chronologically associated with COVID-19 exposure,denotes another scientific and clinical conundrum that exemplifies the complexity of pediatric immunity.Despite the considerable dissimilarities between the pediatric and adult immune systems,clinical trials dedicated to children are lacking and current management recommendations are largely adapted from adult guidelines.Conclusions Severe pediatric COVID-19 can affect multiple organ systems.The dysregulated immune pathways in severe COVID-19 shape the disease course,epitomize the vast functional diversity of the pediatric immune system and highlight the immun

关键词： Immunopathophysiology MIS-C Pediatric critical care Severe pediatric COVID-19

Electrochemical filtration for drinking water purification:A review on membrane materials,mechanisms and roles

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第7期141卷 102-128页

作者： Yuying Qi Donghao li Shixuan Zhang Fengxiang li Tao hua College of Environmental Science and Engineering Nankai UniversityTianjin 300350China Key Laboratory of Pollution Process and Environmental Criteria Ministry of EducationTianjin 300350China Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation Tianjin 300350China

Electrochemical filtration can not only enrich low concentrations of pollutants but also produce reactive oxygen species to interact with toxic pollutants with the assistance of a power supply,making it an effective strategy for drinking water purification.In addition,the application of electrochemical filtration facilitates the reduction of pretreatment procedures and the use of chemicals,which has outstanding potential for maximizing process simplicity and reducing operating costs,enabling the production of safe drinking water in smaller installations.In recent years,the research on electrochemical filtration has gradually increased,but there has been a lack of attention on its application in the removal of low concentrations of pollutants from low conductivity water.In this review,membrane substrates and electrocatalysts used to improve the performance of electrochemical membranes are briefly summarized.Meanwhile,the application prospects of emerging single-atom catalysts in electrochemical filtration are also presented.Thereafter,several electrochemical advanced oxidation processes coupled with membrane filtration are described,and the related working mechanisms and their advantages and shortcomings used in drinking water purification are illustrated.Finally,the roles of electrochemical filtration in drinking water purification are presented,and the main problems and future perspectives of electrochemical filtration in the removal of low concentration pollutants are discussed.

关键词： Electrochemical filtration Drinking water Conductive membrane Low concentration Electrocatalyst

Predictive model using four ferroptosis-related genes accurately predicts gastric cancer prognosis

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2024年第5期16卷 2018-2037页

作者： li Wang Wei-hua Gong Department of Emergency The Second Affiliated Hospital of Zhejiang University School of MedicineHangzhou 310000Zhejiang ProvinceChina Department of Surgery The Second Affiliated Hospital Zhejiang University School of MedicineHangzhou 310052Zhejiang ProvinceChina

BACKGROUND Gastric cancer(GC)is a common malignancy of the digestive system.According to global 2018 cancer data,GC has the fifth-highest incidence and the thirdhighest fatality rate among malignant tumors.More than 60%of GC are linked to infection with Helicobacter pylori(H.pylori),a gram-negative,active,microaerophilic,and helical bacterium.This parasite induces GC by producing toxic factors,such as cytotoxin-related gene A,vacuolar cytotoxin A,and outer membrane proteins.Ferroptosis,or iron-dependent programmed cell death,has been linked to GC,although there has been little research on the link between H.pylori infection-related GC and ferroptosis.AIM To identify coregulated differentially expressed genes among ferroptosis-related genes(FRGs)in GC patients and develop a ferroptosis-related prognostic model with discrimination ability.METHODS Gene expression profiles of GC patients and those with H.pylori-associated GC were obtained from The cancer Genome Atlas and Gene Expression Omnibus(GEO)databases.The FRGs were acquired from the FerrDb database.A ferroptosis-related gene prognostic index(FRGPI)was created using least absolute shrinkage and selection operator–Cox regression.The predictive ability of the FRGPI was validated in the GEO cohort.Finally,we verified the expression of the hub genes and the activity of the ferroptosis inducer FIN56 in GC cell lines and tissues.RESULTS Four hub genes were identified(NOX4,MTCH1,GABARAPL2,and SLC2A3)and shown to accurately predict GC and H.pylori-associated GC.The FRGPI based on the hub genes could independently predict GC patient survival;GC patients in the high-risk group had considerably worse overall survival than did those in the low-risk group.The FRGPI was a significant predictor of GC prognosis and was strongly correlated with disease progression.Moreover,the gene expression levels of common immune checkpoint proteins dramatically increased in the highrisk subgroup of the FRGPI cohort.The hub genes were also confirmed to be highly overexpressed in GC cell line

关键词： Ferroptosis Gastric cancer Helicobacter pylori infection Immune checkpoint protein Prognostic model Ferroptosis-related gene prognostic index

Catalytic asymmetric dearomative azo-Diels–Alder reaction of 2-vinlyindoles

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第4期35卷 357-362页

作者： Yu-Hang Miao Zheng-Xu Zhang Xu-Yi huang Yuan-Zhao hua Shi-Kun Jia Xiao Xiao Min-can Wang li-Ping Xu Guang-Jian Mei Green Catalysis Center and College of ChemistryZhengzhou UniversityZhengzhou 450052China School of Chemistry and Chemical Engineering Shandong University of TechnologyZibo 255000China Institute of Pharmaceutical Science and Technology Zhejiang University of TechnologyHangzhou 310014China

Due to the high electrophilic nature of azo-dienophiles, azo-Diels–Alder proceeds rapidly even without the need of a catalyst and is therefore regarded as the “click reaction”. This spontaneity causes strong background reaction and poses a daunting challenge to chemists for developing the catalytic asymmetric version. Reported herein is the first catalytic asymmetric dearomative azo-Diels–Alder reaction between2-vinylindoles and triazoledione. This protocol makes use of the high energy barrier of dearomatization to avert the strong background reaction of azo-Diels–Alder reaction, allowing the implementation of the projected reaction at ambient temperature. Density functional theory calculations have been performed to gain insights into the reaction mechanism and the origins of the enantioselectivity. By using this method,a variety of tetracyclic indole derivatives have been readily prepared in good to excellent yields and with excellent diastereo-and enantio–selectivities(33 examples, up to 97% yield and >99% ee, >20:1 dr).

关键词： Catalytic asymmetric dearomatization Azo-Diels–Alder reaction 2-Vinylindoles Chiral phosphoric acid Tetracyclic indole derivatives

The crosstalk between enteric nervous system and immune system in intestinal development,homeostasis and diseases

在线全文

学校读者我要写书评

暂无评论

Science China(life Sciences) 2024年第1期67卷 41-50页

作者： Xindi Wang Chenbo Ding hua-Bing li Shanghai Institute of Immunology State Key Laboratory of Oncogenes and Related GenesShanghai Jiao Tong University School of MedicineShanghai 200025China Shanghai Jiao Tong University School of Medicine-Yale Institute for Immune Metabolism Shanghai Jiao Tong University School of MedicineShanghai 200025China

The gut is the largest digestive and absorptive organ,which is essential for induction of mucosal and systemic immune responses,and maintenance of metabolic-immune homeostasis.The intestinal components contain the epithelium,stromal cells,immune cells,and enteric nervous system(ENS),as well as the outers,such as gut microbiota,metabolites,and nutrients.The dyshomeostasis of intestinal microenvironment induces abnormal intestinal development and functions,even colon diseases including dysplasia,inflammation and tumor.Several recent studies have identified that ENS plays a crucial role in maintaining the immune homeostasis of gastrointestinal(GI)microenvironment.The crosstalk between ENS and immune cells,mainly macrophages,T cells,and innate lymphoid cells(ILCs),has been found to exert important regulatory roles in intestinal tissue programming,homeostasis,function,and inflammation.In this review,we mainly summarize the critical roles of the interactions between ENS and immune cells in intestinal homeostasis during intestinal development and diseases progression,to provide theoretical bases and ideas for the exploration of immunotherapy for gastrointestinal diseases with the ENS as potential novel targets.

关键词： enteric nervous system macrophages T cells innate lymphoid cells neuro-immune interactions

Improving anammox activity and reactor start-up speed by using CO_(2)/NaHCO_(3) buffer

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第5期139卷 60-71页

作者： Shaoan Cheng huahua li Xinyuan He hua Chen Longxin li State Key Laboratory of Clean Energy Utilization College of Energy EngineeringZhejiang UniversityHangzhou 310027China

Anammox bacteria grow slowly and can be affected by large pH fluctuations.Using suitable buffers could make the start-up of anammox reactors easy and rapid.In this study,the effects of three kinds of buffers on the nitrogen removal and growth characteristics of anammox sludge were investigated.Reactors with CO_(2)/NaHCO_(3)buffer solution(CCBS)performed the best in nitrogen removal,while 4-(2-hydroxyerhyl)piperazine-1-ethanesulfonic acid(HEPES)and phosphate buffer solution(PBS)inhibited the anammox activity.Reactors with 50 mmol/L CCBS could start up in 20 days,showing the specific anammox activity and anammox activity of 1.01±0.10 gN/(gVSS·day)and 0.83±0.06 kgN/(m^(3)·day),respectively.candidatus Kuenenia was the dominant anammox bacteria,with a relative abundance of 71.8%.Notably,anammox reactors could also start quickly by using 50 mmol/L CCBS under nonstrict anaerobic conditions.These findings are meaningful for the quick start-up of engineered anammox reactors and prompt enrichment of anammox bacteria.

关键词： Anammox bacteria Buffer solution CO_(2)/NaHCO_(3) Physiological characteristics Microbial community shift