检索结果-南通市图书馆

Earthquake Engineering and Engineering Vibration 2024年第2期23卷 389-401页

作者： Adolfo Foriero Filippo Santucci de Magistris Giovanni Fabbrocino Département de génie civil et de génie des eaux Pavillon Adrien-PouliotUniversitéLavalQuébecCanada Dipartimento di Bioscienze e Territorio Universitàdegli Studi del MoliseCampobassoItaly construction Technologies Institute National Research CouncilITC-CNRL’AquilaItaly

This work presents a novel approach to the dynamic response analysis of a Euler-Bernoulli beam resting on a Winkler soil model and subjected to an impact loading.The approach considers that damping has much less importance in controlling the maximum response to impulsive loadings because the maximum response is reached in a very short time,before the damping forces can dissipate a significant portion of the energy input into the system.The development of two sine series solutions,relating to different types of impulsive loadings,one involving a single concentrated force and the other a distributed line load,are presented.This study revealed that when a simply supported Euler-Bernoulli beam,resting on a Winkler soil model,is subject to an impact load,the resulting vertical displacements,bending moments and shear forces produced along the span of the beam are considerably affected.In particular,the quantification of this effect is best observed,relative to the corresponding static solution,via an amplification factor.The computed impact amplification factors,for the sub-grade moduli used in this study,were in magnitude greater than 2,thus confirming the multiple-degree-of-freedom nature of the problem.

关键词： beam-Winkler-soil model sub-grade moduli impact load impact distributed line load dynamic solution impact amplification factor

Mid-term survival of the Optimys short stem: A prospective case series of 500 patients

在线全文

学校读者我要写书评

暂无评论

World Journal of Orthopedics 2024年第3期15卷 257-265页

作者： Bryan Hamans Sheryl de Waard Sjoerd Kaarsemaker Esther R c Janssen Inger N Sierevelt Gino M M J Kerkhoffs Daniël Haverkamp department of Orthopaedic Surgery Xpert ClinicAmsterdam 1101EANetherlands department of Orthopedic Surgery Amsterdam University Medical CenterAmsterdam 1105 AZNetherlands Esther R c Janssen Department of Orthopaedic SurgeryViecuri Medisch CentrumVenlo 5912 BLNetherlands centre for Orthopaedic Research Spaarne ZiekenhuisHoofddorp 2134 TMNetherlands department of Orthopaedic Surgery and Sports Medicine Amsterdam UMC-Location AMCAmsterdam 1105 AZNetherlands department of Orthopedic Surgery Xpert Orthopedic Surgery ClinicAmsterdam 1101 EANetherlands

BAcKGROUND In recent years,there has been an increase in the number of total hip arthroplasty procedures in the younger patient population.This active group has higher expectations of their prosthesis in comparison to the older population,and there is a greater physical demand for the prosthesis.Short femoral stems were in-troduced to retain proximal bone stock and joint biomechanics and became more common to implant in this specific population.currently,the long-term survival and functional outcomes of various short stems are still being investigated in different clinics.AIM To determine the 5-year survival of the Optimys hip stem.METHODS This was a prospective multicenter cohort study of 500 patients conducted in two hospitals in the Netherlands.All patients received the Optimys short stem(Mathys Ltd,Bettlach,Switzerland).The primary outcome measure was survival of the hip stem,with revision as the endpoint.The secondary outcome measurements included patient-reported outcome measures(PROMs).Kaplan-Meier analysis was used to calculate the 5-year survival rate.Log-minus-log transformation was performed to calculate the 95%confidence interval(95%cI).Mixed model analyses were performed to assess the course of the PROMs during the 1st 2 years after surgery.Analyses were modeled separately for the 1st and 2nd years to calculate the yearly change in PROMs during both follow-up periods with accompanying 95%cIs.RESULTS The mean age of the total 500 patients was 62.3 years(standard deviation:10.6)and 202 were male(40%).At a median follow-up of 5.5 years(interquartile range:4.5-6.7),7 patients were deceased and 6 revisions were registered,for infection(n=3),subsidence(n=2)and malposition(n=1).This resulted in an overall 5-year survival of 98.8%(95%cI:97.3-99.5).If infection was left out as reason for revision,a stem survival of 99.4%(95%cI:98.1-99.8)was seen.Baseline questionnaires were completed by 471 patients(94%),317 patients(63%)completed the 1-year follow-up questionnaires and 233 patients(47%)completed the 2-year f

关键词： Total hip arthroplasty Femoral stem Short stem Optimys Survival 5-year survival Revision PROMs

Simulated rainfall in Brazil:An alternative for assesment of soil surface processes and an opportunity for technological development

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Soil and Water conservation Research 2024年第1期12卷 29-42页

作者： camila calazans da Silva Luz Wilk Sampaio de Almeida Adilson Pacheco de Souza Nivaldo Schultz Jamil Alexandre Ayach Anache Daniel Fonseca de carvalho Postgraduate Program in Agronomy-Soil Sciences Federal Rural University of Rio de JaneiroSeropédicaRJBrazil Agronomy department Federal Institute of EducationScience and Technology of RondôniaAriquemesROBrazil Federal University of Mato Grosso SinopMTBrazil Federal Rural University of Rio de Janeiro SeropédicaRJBrazil Federal University of Mato Grosso do Sul Campo GrandeMSBrazil

Rainfall simulators(RS)have been used,above all,to evaluate hydrological processes related to soil water infiltration,surface runoff and soil erosion.They allow repeatability of rain application with different precipitation intensities in field and/or laboratory conditions and should produce events with physical characteristics similar to natural rain.In this manuscript,we carried out a bibliometric and scientometric analysis of studies with simulated rainfall in Brazil to assess the temporal evolution of publications,the main topics addressed and the degree of technological development of the equipment.We searched for the terms“rainfall simulator”OR“simulated rainfall”AND“Brazil”in the Scopus,Web of Science,SciELO and Google Scholar databases.We found 143 articles published in the last 37 years(1985-2022).Our findings indicate that the main research areas covered in papers are soil erosion(57.34%),soil water infiltration(24.47%),nutrient losses(9.8%)and RS development and calibration/assessment(8.39%).In recent years,the number of published papers in international high-impact factor journals has increased.Most of the papers(49.65%)refer to studies carried out by institutions located in the south and southeast regions of Brazil.Moreover,there is a large gap of studies on simulated rainfall in other regions of Brazil,where important biomes such as the cerrado,Amazon,caatinga,and their transitions are located.This study informs research priorities on soil erosion under simulated rainfall and provides a bibliographic database that can assist in more detailed future analyses.

关键词： Rainfall simulator Soil and water losses Soil water infiltration Bibliometrics Scientific review

Sturge–Weber syndrome:an update for the pediatrician

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 Pediatrics 2024年第5期20卷 435-443页

作者： Emilie Dingenen Damien Segers Hannelore de Maeseneer Dirk Van Gysel Ghent University Faculty of Medicine and Health Sciences GhentBelgium department of Pediatrics O.L.Vrouw Hospital AalstMoorselbaan 1649300AalstBelgium Interdisciplinary Unit of Pediatric.dermatology Vrije Universiteit Brussel(VUB)Universitair Ziekenhuis Brussel(UZ Brussel)BrusselsBelgium

Sturge–Weber syndrome(SWS)is a rare congenital neurocutaneous disorder characterized by the simultaneous presence of both cutaneous and extracutaneous capillary malformations.SWS usually presents as a facial port-wine birthmark,with a varying presence of leptomeningeal capillary malformations and ocular vascular abnormalities.The latter may lead to significant neurological and ocular morbidity such as epilepsy and glaucoma.SWS is most often caused by a somatic mutation involving the G protein subunit alpha Q or G protein subunit alpha 11 gene causing various alterations in downstream signaling pathways.We specifically conducted a comprehensive review focusing on the current knowledge of clinical practices,the latest pathophysiological insights,and the potential novel therapeutic avenues they provide.Data sources A narrative,non-systematic review of the literature was conducted,combining expert opinion with a balanced review of the available literature.A search of PubMed,Google Scholar and Embase was conducted,using keywords“Sturge–Weber Syndrome”OR“SWS”,“capillary malformations”,“G protein subunit alpha 11”OR“G protein subunit alpha Q”.Results One of the hallmark features of SWS is the presence of a port-wine birthmark at birth,and forehead involvement is most indicative for SWS.The most common ocular manifestations of SWS are glaucoma and choroidal hemangioma.Glaucoma presents in either in infancy(0–3 years of age)or later in life.Neurological complications are common in SWS,occurring in about 70%–80%of patients,with seizures being the most common one.SWS significantly impacts the quality of life for patients and their families,and requires a multidisciplinary approach for diagnosis and treatment.currently,no disease-modifying therapies exist,and treatment is mostly focused on symptoms or complications as they arise.conclusions SWS remains a complex and heterogeneous disorder.Further research is needed to optimize diagnostic and therapeutic strategies,and to translate insights from molecular pathogenesis to clin

关键词： capillary malformations G-protein Gq-G11 Port-wine birthmark Neurocutaneous disorder Sturge-Weber syndrome

ENSO impacts on litter stocks and water holding capacity in secondary forests in eastern Amazonia

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 Forestry Research 2024年第1期35卷 83-89页

作者： Julia Isabella de Matos Rodrigues Walmer Bruno Rocha Martins Victor Pereira de Oliveira Myriam Suelen da Silva Wanzerley Hélio Brito dos Santos Júnior Francisco de Assis Oliveira Graduate Program in Forestry Sciences Av.Presidente Tancredo Neves2501BelémPará66077-530Brazil Federal Rural University of Amazonia Av.Presidente Tancredo Neves2501BelémPará66077-530Brazil Federal Rural University of Amazonia Tv.Pau-AmareloCapitão PoçoPará68650-000Brazil National Institute of Amazonia Research Av.Constelação Cruzeiro do SulManausAmazonas 69060-062Brazil

Among the impacts of climate change,there is the intensification of phenomena such as the El Niño South-ern Oscillation(ENSO)responsible for El Niño and La Niña.However,understanding their effects on the functional pro-cesses of forests is limited.Therefore,this study evaluated the effects of ENSO on litter stock and water holding capac-ity(WHc)in a successional forest in eastern Amazonia.Evaluations occurred in periods with the most rainfall in El Niño(2019)and least in La Niña(2021)years.Twelve permanent plots were used to sample litter.ENSO effects were evident for WHc,higher during El Niño.However,this influence was not clear for litter,as only in the rainy season effects were found.There was a positive correlation of WHc with precipitation and humidity,while litter stocks were negatively correlated with temperature and wind speed.Although the subject of this study requires long-term assessments,preliminary results suggests that,depending on the intensity of ENSO,forest functional processes can be strongly impacted and altered.The conclusion reinforces warnings by the scientific community about the impacts of climate change on the maintenance of litter stocks,decomposition and,consequently,the biogeochemical cycle and essential ecosystem services for the maintenance of Amazonia biodiversity.The need to develop long-term research to understand the effects of climatic change on litter stocks and water holding capacity is highlighted,especially in Amazonia.

关键词： Seasonality climate change Succession ecosystem Biogeochemical cycle Amazonia biodiversity

Traditional chinese medicine for the treatment of immune-related nephropathy:A review

在线全文

学校读者我要写书评

暂无评论

Acta Pharmaceutica Sinica B 2024年第1期14卷 38-66页

作者： Pu Jiang changliang Yao de-an Guo School of Pharmacy Nanjing University of Chinese MedicineNanjing 210023China Shanghai Research center for Modernization of Traditional chinese Medicine National Engineering Research Center of TCM Standardization TechnologyShanghai Institute of Materia MedicaChinese Academy of SciencesShanghai 201203China

Immune-related nephropathy(IRN)refers to immune-response-mediated glomerulonephritis and is the main cause of end-stage renal failure.The pathogenesis of IRN is not fully understood;therefore,treatment is challenging.Traditional chinese medicines(TcMs)have potent clinical effects in the treatment of the IRN conditions immunoglobulin A nephropathy,lupus nephropathy,and diabetic nephropathy.The underlying mechanisms mainly include its inhibition of inflammation;improvements to renal interstitial fibrosis,oxidative stress,autophagy,apoptosis;and regulation of immunity.In this review,we summarize the clinical symptoms of the three IRN subtypes and the use of TcM prescriptions,herbs,and bioactive compounds in treating IRN,as well as the potential mechanisms,intending to provide a reference for the future study of TcM as IRN treatments.

关键词： IgA nephropathy Diabetic nephropathy Lupus nephritis Traditional chinese medicine Immunity Pathogenesis Mechanism Pathophysiology

Unraveling the enigma:A comprehensive review of solid pseudopapillary tumor of the pancreas

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3期16卷 614-629页

作者： Ye-cheng Xu de-Liang Fu Feng Yang department of Pancreatic Surgery Pancreatic Disease InstituteHuashan HospitalFudan UniversityShanghai 200040China

Solid pseudopapillary tumor of the pancreas(SPTP)is a rare neoplasm predom-inantly observed in young females.Pathologically,cTNNB1 mutations,β-catenin nuclear accumulation,and subsequent Wnt-signaling pathway activation are the leading molecular features.Accurate preoperative diagnosis often relies on imaging techniques and endoscopic biopsies.Surgical resection remains the mainstay treatment.Risk models,such as the Fudan Prognostic Index,show promise as predictive tools for assessing the prognosis of SPTP.Establishing three types of metachronous liver metastasis can be beneficial in tailoring individu-alized treatment and follow-up strategies.despite advancements,challenges persist in understanding its etiology,establishing standardized treatments for unresectable or metastatic diseases,and developing a widely recognized grading system.This comprehensive review aims to elucidate the enigma by consolidating current knowledge on the epidemiology,clinical presentation,pathology,molecular characteristics,diagnostic methods,treatment options,and prognostic factors.

关键词： Pancreas Solid pseudopapillary tumor β-catenin Endoscopic ultrasound Surgery Recurrence Liver metastasis Prognostic prediction

The effect of abiotic stresses on plant c:N:P homeostasis and their mitigation by silicon

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The crop Journal 2024年第2期12卷 340-353页

作者： Milton Garcia costa Renato de Mello Prado Luiz Fabiano Palaretti Jonas Pereira de Souza Júnior department of Agricultural Production Science School of Agricultural and Veterinarian SciencesSão Paulo State UniversityJaboticabalBrazil

In crop plants, various environmental stresses affect the balance of carbon, nitrogen, and phosphorus(c:N:P), leading to biochemical and physiological alterations and reductions in yield. Silicon(Si) is a beneficial element that alleviates plant stress. Most studies involving silicon have focused on physiological responses, such as improvements in photosynthetic processes, water use efficiency, and antioxidant defense systems. But recent research suggests that stressed plants facing either limited or excessive resources(water, light, nutrients, and toxic elements), strategically employ Si to maintain c:N:P homeostasis, thereby minimizing biomass losses. Understanding the role of Si in mitigating the impact of abiotic stresses on plants by regulating c:N:P homeostasis holds great potential for advancing sustainable agricultural practices in crop production. This review presents recent advances in characterizing the influence of environmental stresses on c:N:P homeostasis, as well as the role of Si in preserving c:N:P equilibrium and attenuating biological damage associated with abiotic stress. It underscores the beneficial effects of Si in sustaining c:N:P homeostasis and increasing yield via improved nutritional efficiency and stress mitigation.

关键词： Nutritional stoichiometry Elemental stoichiometry Beneficial element Environmental stresses Nutritional efficiency carbon use efficiency Agricultural sustainability

维普期刊数据库博看期刊

A numerical model to simulate the transient frictional viscoelastic sliding contact

在线全文

学校读者我要写书评

暂无评论

Friction 2024年第2期12卷 319-339页

作者： Dongze WANG Gregory de BOER Anne NEVILLE Ali GHANBARZAdeH School of Mechanical Engineering University of LeedsLeeds LS29JTUK

Sliding motion has always been one of the major concerns when it comes to the analysis of viscoelastic contact problems.A new model simulating the transient sliding contact of smooth viscoelastic surfaces is developed in this paper.By taking the dry contact friction and the coupling between shear tractions and normal pressure into account,the effect of the early partial slip period,which is often neglected in the study of viscoelastic sliding contact problems,is investigated numerically.compared with solutions based on the frictionless assumption,the steady-state pressure profile is found to be slightly different under the effect of the partial slip regime,including a lower peak pressure and the shift of the contacting region in the direction opposite to the sliding motion.Furthermore,the time required for the viscoelastic contact to reach its steady state is delayed owing to the partial slip period preceding the global sliding motion.

关键词： contact mechanics frictional sliding viscoelasticity viscoelastic friction

Prediction models of burst strength degradation for casing with considerations of both wear and corrosion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第1期21卷 458-474页

作者： Jie-Li Wang Wen-Jun Huang de-Li Gao MOE Key Laboratory of Petroleum Engineering China University of PetroleumBeijing102249China State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing102249China

casing wear and casing corrosion are serious problems affecting casing integrity failure in deep and ultra-deep wells.This paper aims to predict the casing burst strength with considerations of both wear and corrosion.Firstly,the crescent wear shape is simplified into three categories according to common mathematical models.Then,based on the mechano-electrochemical(M-E)interaction,the prediction model of corrosion depth is built with worn depth as the initial condition,and the prediction models of burst strength of the worn casing and corroded casing are obtained.Secondly,the accuracy of different prediction models is validated by numerical simulation,and the main influence factors on casing strength are obtained.At last,the theoretical models are applied to an ultra-deep well in Northwest china,and the dangerous well sections caused by wear and corrosion are predicted,and the corrosion rate threshold to ensure the safety of casing is obtained.The results show that the existence of wear defects results in a stress concentration and enhanced M-E interaction on corrosion depth growth.The accuracy of different mathematical models is different:the slot ring model is most accurate for predicting corrosion depth,and the eccentric model is most accurate for predicting the burst strength of corroded casing.The burst strength of the casing will be overestimated by more than one-third if the M-E interaction is neglected,so the coupling effect of wear and corrosion should be sufficiently considered in casing integrity evaluation.

关键词： deep well casing integrity casing wear casing corrosion Burst strength