检索结果-南通市图书馆

Simulation of Corrosion-Induced Cracking of Reinforced Concrete Based on Fracture Phase Field Method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第3期138卷 2257-2276页

作者： Xiaozhou Xia Changsheng Qin guangda Lu xin gu Qing Zhang College of Mechanics and Materials Hohai UniversityNanjing210098China State Key Laboratory of Disaster Reduction in Civil Engineering&College of Civil Engineering Tongji UniversityShanghai200092China

Accurate simulation of the cracking process caused by rust expansion of reinforced concrete(RC)structures plays an intuitive role in revealing the corrosion-induced failure mechanism.Considering the quasi-brittle fracture of concrete,the fracture phase field driven by the compressive-shear term is constructed and added to the traditional brittle fracture phase field model.The rationality of the proposed model is verified by a mixed fracture example under a shear displacement load.Then,the extended fracture phase model is applied to simulate the corrosion-induced cracking process of RC.The cracking patterns caused by non-uniform corrosion expansion are discussed for RC specimens with homogeneous macroscopically or heterogeneous with different polygonal aggregate distributions at the mesoscopic scale.Then,the effects of the protective layer on the crack propagation trajectory and cracking resistance are investigated,illustrating that the cracking angle and cracking resistance increase with the increase of the protective layer thickness,consistent with the experimental observation.Finally,the corrosion-induced cracking process of concrete specimens with large and small spacing rebars is simulated,and the interaction of multiple corrosion cracking is easily influenced by the reinforcement spacing,which increases with the decrease of the steel bar interval.These conclusions play an important role in the design of engineering anti-corrosion measures.The fracture phase field model can provide strong support for the life assessment of RC structures.

关键词： Fracture phase field corrosion-induced cracking non-uniform corrosion expansion protective layer thickness reinforcement concrete

Health diagnosis of ultrahigh arch dam performance using heterogeneous spatial panel vector model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Water Science and Engineering 2024年第2期17卷 177-186页

作者： Er-feng Zhao xin Li Chong-shi gu The National Key Laboratory of Water Disaster Prevention Hohai UniversityNanjing 210098China NationalEngineering Research Centerof Water Resources Eficient Utilization and Engineering Safety Hohai UniversityNanjing 20098China

Currently,more than ten ultrahigh arch dams have been constructed or are being constructed in China.Safety control is essential to long-term operation of these dams.This study employed the flexibility coefficient and plastic complementary energy norm to assess the structural safety of arch dams.A comprehensive analysis was conducted,focusing on differences among conventional methods in characterizing the structural behavior of the Xiaowan arch dam in China.Subsequently,the spatiotemporal characteristics of the measured performance of the Xiaowan dam were explored,including periodicity,convergence,and time-effect characteristics.These findings revealed the governing mechanism of main factors.Furthermore,a heterogeneous spatial panel vector model was developed,considering both common factors and specific factors affecting the safety and performance of arch dams.This model aims to comprehensively illustrate spatial heterogeneity between the entire structure and local regions,introducing a specific effect quantity to characterize local deformation differences.Ultimately,the proposed model was applied to the Xiaowan arch dam,accurately quantifying the spatiotemporal heterogeneity of dam performance.Additionally,the spatiotemporal distri-bution characteristics of environmental load effects on different parts of the dam were reasonably interpreted.Validation of the model prediction enhances its credibility,leading to the formulation of health diagnosis criteria for future long-term operation of the Xiaowan dam.The findings not only enhance the predictive ability and timely control of ultrahigh arch dams'performance but also provide a crucial basis for assessing the effectiveness of engineering treatment measures.

关键词： Ultrahigh arch dam Structural performance Deformation behavior Diagnosis criterion Panel data model

Influence of transcatheter arterial embolization on symptom distress and fatigue in liver cancer patients

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2024年第3期16卷 810-818页

作者： Xu-Min Yang Xu-Yan Yang xin-Yu Wang Yue-Xia gu Department of Nursing The First Affiliated Hospital of Naval Medical University(Changhai Hospital)Shanghai 200433China Department of Thyroid Breast and Vascular SurgeryShanghai Fourth People’s Hospital Affiliated to Tongji University School of MedicineShanghai 200434China Department of Nursing Shanghai Fourth People’s Hospital Affiliated to Tongji University School of MedicineShanghai 200434China

BACKGROUND Hepatocellular carcinoma(HCC)is a prevalent malignancy,and transcatheter arterial embolization(TAE)has emerged as a pivotal therapeutic modality.How-ever,TAE may induce symptom distress and fatigue,adversely affecting the quality of life of patients.AIM To investigate symptom distress,fatigue,and associated factors in HCC patients undergoing TAE.METHODS We used a cross-sectional design and purposive sampling to enroll HCC patients who underwent TAE at our institution from January to December 2022.Question-naires were utilized to collect data on symptom distress and fatigue scores from the first to the third day after TAE.RESULTS Our study revealed a significant reduction in fatigue and symptom distress among patients after TAE.Pain,fatigue,insomnia,fever and abdominal dis-tension were the most common symptoms troubling patients during the first 3 d post-TAE.Marital status,presence of family support,physical functional status,age,and symptom distress were identified as predictors of fatigue in patients.CONCLUSION Healthcare professionals should educate HCC patients on symptom distress and INTRODUCTION Hepatocellular carcinoma(HCC)ranks as the fifth most prevalent cancer and the third leading cause of cancer-related mortality globally.Surgical intervention remains the cornerstone of HCC treatment;however,due to the challenges associated with early diagnosis and the lack of specific diagnostic markers,a considerable proportion of patients are diagnosed at advanced stages,rendering them ineligible for surgical interventions.Transcatheter arterial embolization(TAE)is an interventional therapeutic approach involving the insertion of a fine catheter via the femoral artery to reach the vasculature near the tumor site.TAE aims to obstruct the arterial supply to the tumor by deploying embolic agents,thereby inducing necrosis in cancer cells.This procedure is suitable for patients with good liver function and overall health,particularly those with large HCCs that have not invaded the portal vein[1,2].Nonetheless,

关键词： Transcatheter arterial embolization Fatigue Symptom distress Hepatocellular carcinoma Influencing factors

Insect-specific RNA virus affects the stylet penetration activity of brown citrus aphid(Aphis citricidus)to facilitate its transmission

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2024年第1期31卷 255-270页

作者： xin An Qiaoying gu Jing Wang Tengyu Chang Wei Zhang Jin-Jun Wang Jinzhi Niu Key Laboratory of Entomology and Pest Control Engineering College of Plant ProtectionAcademy of Agricultural ScienceSouthwest UniversityChongqingChina

Sap-sucking insects often transmit plant viruses but also carry insect viruses,which infect insects but not plants.The impact of such insect viruses on insect host biology and ecology is largely unknown.Here,we identified a novel insect-specific virus carried by brown citrus aphid(Aphis citricidus),which we tentatively named Aphis citricidus picornavirus(AcPV).Phylogenetic analysis discovered a monophyletic cluster with AcPV and other unassigned viruses,suggesting that these viruses represent a new family in order Picornavirales.Systemic infection with AcPV triggered aphid antiviral immunity mediated by RNA interference,resulting in asymptomatic tolerance.Importantly,we found that AcPV was transmitted horizontally by secretion of the salivary gland into the feeding sites of plants.AcPV influenced aphid stylet behavior during feeding and increased the time required for intercellular penetration,thus promoting its transmission among aphids with plants as an intermediate site.The gene expression results suggested that this mechanism was linked with transcription of salivary protein genes and plant defense hormone signaling.Together,our results show that the horizontal transmission of AcPV in brown citrus aphids evolved in a manner similar to that of the circulative transmission of plant viruses by insect vectors,thus providing a new ecological perspective on the activity of insect-specific viruses found in aphids and improving the understanding of insect virus ecology.

关键词： electrical penetration graph feeding behavior insect virus transmission Picornavirales salivary protein

Research on Hepatocyte Regulation of PCSK9-LDLR and Its Related Drug Targets

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 Integrative Medicine 2024年第7期30卷 664-672页

作者： LIU Su-su YU Tong QIAO Yan-fang gu Shu-xiao CHAI xin-lou School of Traditional Chinese Medicine Beijing University of Chinese Medicine

The prevalence of hyperlipidemia has increased significantly due to genetic, dietary, nutritional and pharmacological factors, and has become one of the most common pathological conditions in humans. Hyperlipidemia can lead to a range of diseases such as atherosclerosis, stroke, coronary heart disease, myocardial infarction, diabetes, and kidney failure, etc. High circulating low-density lipoprotein cholesterol(LDL-C) is one of the causes of hyperlipidemia. LDL-C in the blood binds to LDL receptor(LDLR) and regulates cholesterol homeostasis through endocytosis. In contrast, proprotein convertase subtilisin/kexin type 9(PCSK9) mediates LDLR degradation via the intracellular and extracellular pathways, leading to hyperlipidemia. Targeting PCSK9-synthesizing transcription factors and downstream molecules are important for development of new lipid-lowering drugs. Clinical trials regarding PCSK9 inhibitors have demonstrated a reduction in atherosclerotic cardiovascular disease events. The purpose of this review was to explore the target and mechanism of intracellular and extracellular pathways in degradation of LDLR and related drugs by PCSK9 in order to open up a new pathway for the development of new lipid-lowering drugs.

关键词： hyperlipidemia proprotein convertase subtilisin/kexin type 9 low-density lipoprotein receptor intracellular pathway extracellular pathway

New horizons for selenium in animal nutrition and functional foods

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Animal Nutrition 2022年第4期11卷 80-86页

作者： xin gu Chun-qi Gao guangdong Provincial Key Laboratory of Animal Nutrition Control/Key Laboratory of Chicken Genetics Breeding and ReproductionMinistry of AgricultureCollege of Animal ScienceSouth China Agricultural University GuangdongChina College of Animal SciencesZhejiang UniversityHangzhouChina

Selenium(Se),one of the indispensable nutrients for both human health and animal growth,participates in various physiological functions,such as antioxidant and immune responses and metabolism.The role of dietary Se,in its organic and inorganic forms,has been well documented in domestic animals.Furthermore,many feeding strategies for different animals have been developed to increase the Se concentration in animal products to address Se deficiency and even as a potential nutritional strategy to treat free radical-associated diseases.Nevertheless,studies on investigating the optimum addition of Se in feed,the long-term consequences of Se usage in food for animal nutrition,the mechanism of metallic Se nanoparticle(SeNP)transformation in vivo,and the nutritional effects of SeNPs on feed workers and the environment are urgently needed.Starting from the absorption and metabolism mechanism of Se,this review discusses the antioxidant role of Se in detail.Based on this characteristic,we further investigated the application of Se in animal health and described some unresolved issues and unanswered questions warranting further investigation.This review is expected to provide a theoretical reference for improving the quality of food animal meat as well as for the development of Se-based biological nutrition enhancement technology.

关键词： Selenium Antioxidant Meat quality Functional foods

维普期刊数据库

Bioinspired metal-organic framework nanozyme reinforced with thermosensitive hydrogel for regulating inflammatory responses in Parkinson’s disease

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第2期17卷 858-865页

作者： Xiaowan Fan Tao Zhang xin Ding Yushuo gu Qing Li Wei Jiang Kelong Fan Nanozyme Medical Center Academy of Medical ScienceZhengzhou UniversityZhengzhou 450001China Department Central-China Branch of National Center for Cardiovascular DiseasesHean Cardiovascular Disease CenterFuwai Central-China HospitalCentral China Fuwai Hospital of Zhengzhou UniversityZhengzhou 450046China Application Center for Precision Medicine the Second Affiliated Hospital of Zhengzhou UniversityZhengzhou 450052China CAS Engineering Laboratory for Nanozyme Key Laboratory of Protein and Peptide PharmaceuticalsInstitute of BiophysicsChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 101408China Department of General Surgery Strategic Support Force Medical CenterBeijing 100101China Department of Anesthesiology Pain and Perioperative MedicineThe First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450052China

Parkinson’s disease(PD)is a prevalent neurodegenerative disorder accompanied by movement disorders and neuroinflammatory injury.Anti-inflammatory intervention to regulate oxidative stress in the brain is beneficial for managing PD.However,traditional natural antioxidants have failed to meet the clinical treatment demands due to insufficient activity and sustainability.Herein,Cu-doping zeolite imidazolate framework-8(ZIF-8)nanozyme is designed to simulate Cu/Zn superoxide dismutase(SOD)by biomimetic mineralization.The nanozyme composite is then integrated into thermosensitive hydrogel(poly(lactic-co-glycolic acid)-poly(ethylene glycol)-poly(lactic-co-glycolic acid)(PLGA-PEG-PLGA))to form an effective antioxidant system(Cu-ZIF@Hydrogel).The thermosensitive hydrogel incorporating nanozymes demonstrate distinct viscoelastic properties aimed at enhancing local nanozyme adhesion,prolonging nanozyme retention time,and modulating antioxidant activity,thus significantly improving the bioavailability of nanozymes.At the cellular and animal levels of PD,we find that Cu-ZIF@Hydrogel bypass the blood-brain barrier and efficiently accumulate in the nerve cells.Moreover,the Cu-ZIF@Hydrogel significantly alleviate the PD’s behavioral and pathological symptoms by reducing the neuroinflammatory levels in the lesion site.Therefore,the hydrogel-incorporating nanozyme system holds great potential as a simple and reliable avenue for managing PD.

关键词： bioinspired nanozyme thermosensitive hydrogel Parkinson’s disease oxidative stress neuroinflammatory

Enhancing the Interaction of Carbon Nanotubes by Metal-Organic Decomposition with Improved Mechanical Strength and Ultra-Broadband EMI Shielding Performance

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第7期16卷 281-294页

作者： Yu-Ying Shi Si-Yuan Liao Qiao-Feng Wang xin-Yun Xu Xiao-Yun Wang xin-Yin gu You-Gen Hu Peng-Li Zhu Rong Sun Yan-Jun Wan Shenzhen Institute of Advanced Electronic Materials Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055People’s Republic of China Southern University of Science and Technology Shenzhen 518055People’s Republic of China National Key Laboratory of Materials for Integrated Circuits Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050People’s Republic of China

The remarkable properties of carbon nanotubes(CNTs)have led to promising applications in the field of electromagnetic inter-ference(EMI)shielding.However,for macroscopic CNT assemblies,such as CNT film,achieving high electrical and mechanical properties remains challenging,which heavily depends on the tube-tube interac-tions of CNTs.Herein,we develop a novel strategy based on metal-organic decomposition(MOD)to fabricate a flexible silver-carbon nanotube(Ag-CNT)film.The Ag particles are introduced in situ into the CNT film through annealing of MOD,leading to enhanced tube-tube interactions.As a result,the electrical conductivity of Ag-CNT film is up to 6.82×10^(5) S m^(-1),and the EMI shielding effectiveness of Ag-CNT film with a thickness of~7.8μm exceeds 66 dB in the ultra-broad frequency range(3-40 GHz).The tensile strength and Young’s modulus of Ag-CNT film increase from 30.09±3.14 to 76.06±6.20 MPa(~253%)and from 1.12±0.33 to 8.90±0.97 GPa(~795%),respectively.Moreover,the Ag-CNT film exhibits excellent near-field shield-ing performance,which can effectively block wireless transmission.This innovative approach provides an effective route to further apply macroscopic CNT assemblies to future portable and wearable electronic devices.

关键词： EMI shielding Mechanical strength Carbon nanotubes Metal-organic decomposition Flexibility

维普期刊数据库

Difluoromethyl phenoxathiinium salt: A new general and versatile difluoromethylating reagent with divergent ·CF_(2)H, CF_(2)H^(+), and :CF_(2) reactivities

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第3期67卷 953-962页

作者： Yuan-Qing gu Hong-xin Long Dan-Dan Zhang Mei-Feng Ruan guo-Kai Liu School of Pharmacy Shenzhen University Medical SchoolShenzhen UniversityShenzhen 518055China

Development of practical and versatile electrophilic difluoromethylating reagent is still a grand challenge so far due to its inherent instability or low reactivity.Herein,we report the design and synthesis of difluoromethyl phenoxathiinium tetrafluoroborate(PT-CF_(2)H^(+)BF_(4)^(-)) as a novel difluoromethylating reagent,which proves to be a bench-stable,general,powerful and versatile reagent with divergent·CF_(2)H,CF_(2)H^(+),and:CF_(2) reactivities.Making use of this reagent,we demonstrated a vast array of difluoromethyl radical transfer reactions via diverse pathways involving photocatalyst-free visible-light induction,visible-light photoredox catalysis and visible-light mediation single electron transfer of EDA complex.Moreover,the green and highly effective CF_(2)H^(+) and:CF_(2) transfer reactions were also readily accomplished.

关键词： difluoromethyl phenoxathiinium salt versatile difluoromethylating reagent difluoromethyl radical difluoromthyl cation difluorocarbene

维普期刊数据库