检索结果-南通市图书馆

A Micromechanics Based Model for Cemented Granular Materials

在线全文

学校读者我要写书评

暂无评论

A Micromechanics Based Model for Cemented Granular Materials

A Cocktail of Natural Compounds Holds Promise for New Immunotherapeutic Potential in Head and Neck Cancer

The Second International Symposium on Constitutive Modeling of Geomaterials:Advances and New Applications(IS-Model 2012)

作者： arghya das Alessandro Tengattini Giang Nguyen Itai Einav Particles and Grains Laboratory The University of Sydney

ISBN: (纸本)9783642328138

＜正＞Cemented Granular Materials（CGMs） consist of a particle skeleton and a solid matrix partially filling the interstitial space.In this broad class we encounter a number of typical geotechnical materials such as sedimentary rocks （Sandstones,Conglomerates and Breccia） as well as naturally and artificially cemented sands.These materials,while showing a brittle behavior under shearing at low confining pressures,are ductile at high confinements.The micro mechanisms involved,that are cement disaggregation,grain crushing and fragment rearrangement, are known to be different in these two cases. Several constitutive models based on the elasto-plastic framework have been developed to describe the behavior of CGMs.However lack of correlations between the underlying failure mechanisms and the only internal variable（plastic strain）,results in the use of parameters that are hard to physically identify,let alone to calibrate. In this paper,we tackle the constitutive modeling of CGMs from a more physical angle,which starts from a micro mechanical observation of grain and cement failure,to a statistical homogenization of grain scale quantities for the constitution of their continuum counterparts.In particular,while the established Continuum Breakage Mechanics approach lends itself to the description of grain crushing process,a novel definition of damage for the cement phase is introduced and shown to be measurable.The whole formulation of the new constitutive model is confined in a thermo-mechanical framework,with explicit links between the internal variables（breakage,damage and plastic strain） and the evolving microstructure of the material.As a consequence,the model possesses only a few physically identifiable and experimentally measurable parameters.The behavior of the model is assessed against experimental observations and its novel features are highlighted.

关键词： Constitutive models Failure mechanisms Granular materials Breccia Elastoplasticity Constitutions Plastic strain MICROMECHANICS Shearing grain granulation

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Chinese Journal of Integrative Medicine 2024年第1期30卷 42-51页

作者： Sunil Kumar Asmita das Department of Biotechnology Delhi Technological UniversityDelhi(110042)India

Objective: To obtain detailed understanding on the gene regulation of natural compounds in altering prognosis of head and neck squamous cell carcinomas(HNSC). Methods: Gene expression data of HNSC samples and peripheral blood mononuclear cells(PBMCs) of HNSC patients were collected from Gene Expression Omnibus(GEO). Differential gene expression analysis of GEO datasets were achieved by the GEO2R tool. Common differentially expressed gerres(DEGs) were screened by comparing DEGs of HNSC with those of PBMCs. The combination was further analyzed for regulating pathways and biological processes that were affected. Results: Totally 110 DEGs were retrieved and identified to be involved in biological processes related to tumor regulation. Then 102 natural compounds were screened for a combination such that the expressions of all 110 commonly DEGs were altered. A combination of salidroside, ginsenoside Rd, oridonin, britanin, and scutellarein was chosen. A multifaceted, multi-dimensional tumor regression was showed by altering autophagy, apoptosis, inhibiting cell proliferation, angiogenesis, metastasis and inflammatory cytokines production. Conclusions: This study has helped develop a unique combination of natural compounds that will markedly reduce the propensity of development of drug resistance in tumors and immune evasion by tumors. The result is crucial to developing a combinatorial natural therapeutic cocktail with accentuated immunotherapeutic potential.

关键词： natural compounds chemopreventive gene expression head and neck cancer immunomodulator salidroside ginsenoside Rd oridonin britanin scutellarein

Effect of eccentric and inclined loading on the bearing capacity of strip footing placed on rock mass

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第1期21卷 292-312页

作者： Shuvankar das Debarghya CHAKRABORTY Department of Civil Engineering Indian Institute of Technology KharagpurWest Bengal-721302India

This paper deals with the bearing capacity determination of strip footing on a rock mass in hilly area by considering the influence of inclined and eccentric loading. Applying the generalized HoekBrown failure criterion, the failure behavior of the rock mass is modeled with the help of the power cone programming in the lower bound finite element limit analysis framework. Using bearing capacity factor(Ns), the change in bearing capacity of the strip footing due to the occurrence of eccentrically inclined loading is presented. The variations of the magnitude of Ns are obtained by examining the effects of the Hoek-Brown rock mass strength parameters(uniaxial compressive strength(sci), disturbance factor(D), rock parameter(mi), and Geological Strength Index(GSI)) in the presence of different magnitudes of eccentricity(e) and inclination angle(λ) with respect to the vertical plane, and presented as design charts. Both the inclined loading modes, i.e., inclination towards the center of strip footing(+λ) and inclination away from the center of strip footing(-λ), are adopted to perform the investigation. In addition, the correlation between the input parameters and the corresponding output is developed by utilizing the artificial neural network(ANN). Additionally, from sensitivity analysis, it is observed that inclination angle(λ) is the most sensitive parameter. For practicing engineers, the obtained design equation and design charts can be beneficial to understand the bearing capacity variation in the existence of eccentrically inclined loading in mountain areas.

关键词： Eccentric and inclined Power cone programming Rock mass Limit analysis Artificial neural network

Boulder-induced form roughness and skin shear stresses in a gravel-bed stream

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第1期21卷 346-360页

作者： das Ratul DATTA Akash Civil Engineering Department National Institute of Technology AgartalaAgartala-799046India

Boulder spacing in mountain rivers and near-wake flow zones within the boulder array is very useful for fish habitat and growth of aquatic organisms.The present study aims to investigate how the boulder array and spacing influence the near-bed flow structures in a gravel-bed stream.Boulders are staggered over a gravel-bed stream with three different inter-boulder spacing namely(a)large(b)medium and(c)small spacing.An acoustic Doppler velocimeter was used for flow measurements in a rectangular channel and the results were compared with those acquired from numerical simulation.The time-averaged velocity profiles at the near-wake flow zones of boulders experience maximum flow retardation which is an outcome of the boulder-induced form roughness.The ratio of velocity differences associated to form and skin roughness and its positive magnitude reveals the dominance of form roughness closest to the boulders.Form roughness computed is 1.75 to 2 times higher than the skin roughness at the near-wake flow region.In particular,the collective immobile boulders placed at different inter-boulder spacings developed high and low bed shear stresses closest to the boulders.The low bed shear stresses characterised by a secondary peak developed at the trough location of the boulders is attributed to the skin shear stress.Further,the spatial averaging of time-averaged flow quantities gives additional impetus to present an improved illustration of fluid shear stresses.The formation of form-induced shear stress is estimated to be 17%to 23%of doubleaveraged Reynolds shear stress and partially compensates for the damping of time-averaged Reynolds shear stress in the interfacial sub-layer.The quadrant analysis of spatial velocity fluctuations depicts that the form-induced shear stresses are dominant in the interfacial sub-layer and have no significance above the gravel-bed surface.

关键词： Array of boulders Near wake flow zones Velocity distributions Skin roughness Form induced shear stresses

A rare co-occurrence of spontaneous pneumomediastinum,pneumothorax,and pneumoperitoneum:Macklin effect

在线全文

学校读者我要写书评

暂无评论

World Journal of Emergency Medicine 2024年第3期15卷 246-248页

作者： Renaldo Pavrey Nikita Makwana Nisha das Centre for Accident and Emergency Medicine Nanavati Max Super Specialty HospitalMumbai 400050India

Spontaneous pneumomediastinum (SPM) is characterized by free air or gas located within the mediastinum that is not associated with any noticeable cause,such as chest trauma,intrathoracic infections,surgery,other organ... 详细信息

关键词： rupture trauma infections

Krüppel-like factor 2(KLF2),a potential target for neuroregeneration

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第11期19卷 2327-2328页

作者： Surajit Hansda Prateeksha Prateeksha Hiranmoy das Department of Pharmaceutical Sciences Jerry H.Hodge School of PharmacyTexas Tech University Health Sciences CenterAmarilloTXUSA

Neurological disorders and injuries lead to the impairment or depletion of neurons in terms of quantity,structure,or function,resulting in the loss of cognitive,emotional,and physical abilities in human beings.This,in turn,accompanies the shortfall of valuable human resources and economic potential,causing a detriment to society.Addressing these challenges,therefore,becomes imperative not only from a humanitarian perspective but also as a means of preserving human capital and bolstering economic prosperity.

关键词： companies injuries potential

New insights into the therapeutic approaches for the treatment of tauopathies

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第5期19卷 1020-1026页

作者： Himanshi Singh Asmita das Mohammad Moshahid Khan Tayebeh Pourmotabbed Department of Microbiology Immunology and BiochemistryUniversity of Tennessee Health Science CenterMemphisTNUSA Department of Biotechnology Delhi Technological UniversityShahbad DaulatpurDelhiIndia Department of Neurology College of MedicineUniversity of Tennessee Health Science CenterMemphisTNUSA Neuroscience Institute University of Tennessee Health Science CenterMemphisTNUSA Center for Muscle Metabolism and NeuropathologyDivision of Regenerative and Rehabilitation Sciences and Department of Physical TherapyCollege of Health ProfessionsUniversity of Tennessee Health Science CenterMemphisTNUSA

Tauopathies are a group of neurological disorders,including Alzheimer’s disease and frontotemporal dementia,which involve progressive neurodegeneration,cognitive deficits,and aberrant tau protein accumulation.The development of tauopathies cannot currently be stopped or slowed down by treatment measures.Given the significant contribution of tau burden in primary tauopathies and the strong association between pathogenic tau accumulation and cognitive deficits,there has been a lot of interest in creating therapies that can alleviate tau pathology and render neuroprotective effects.Recently,small molecules,immunotherapies,and gene therapy have been used to reduce the pathological tau burden and prevent neurodegeneration in animal models of tauopathies.However,the major pitfall of the current therapeutic approach is the difficulty of drugs and gene-targeting modalities to cross the blood-brain barrier and their unintended side effects.In this review,the current therapeutic strategies used for tauopathies including the use of oligonucleotide-based gene therapy approaches that have shown a promising result for the treatment of tauopathies and Alzheimer’s disease in preclinical animal models,have been discussed.

关键词： dementia gene therapies immunotherapy neurodegeneration oligonucleotides tau tauopathies therapies

Ferroptosis mediators vary in metabolic syndrome,type-2 diabetes,and hypercholesterolemia:A meta-analysis report

在线全文

学校读者我要写书评

暂无评论

Genes & Diseases 2024年第3期11卷 109-112页

作者： Indra Kundu Ashlesha Pande Tannishtha das Susan Idicula-Thomas Biomedical Informatics Centre Indian Council of Medical Research-National Institute for Research in Reproductive and Child HealthMumbaiMaharashtra 400012India Department of Biotechnology St.Xavier's CollegeKolkataWest Bengal 700016India

Metabolic syndrome(MetS)is a complex disorder characterized by the coexistence of phenotypes such as obesity,hypertension,hyperglycemia,high triglyceride level,and low level of high-density lipoprotein cholesterol.Inflammation majorly driven by oxidative stress has an overarching role in obesity and IR-mediated mechanisms leading to Mets.Besides these factors.

关键词： obesity cholesterol diabetes

Trace fossil evidences of an Early Miocene paleoseismic event and depositional regime change from the Kutch(Kachchh) Basin

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 Palaeogeography 2024年第1期13卷 165-180页

作者： Ayush Srivastava Sudipta dasgupta Krishanu Chatterjee Mohuli das Bombay Ichnos Research Group Department of Earth SciencesIndian Institute of Technology Bombay(lIT Bombay)PowaiMumbaiMaharashtra400076India

Unconsolidated siliciclastic sediments can undergo post-burial deformation, which leads to the formation of distinctive sedimentary structures, known as soft-sediment deformation structures(SSDS). The presence of a series of sand volcanoes confined to a particular lithostratigraphic horizon can represent a paleoseismic activity and, thereby, exemplifies the concept of “seismite”. The Kutch Basin has been a tectonically active region since the initiation of eastern Gondwana rifting followed by a tectonic inversion during the Cenozoic due to the collision of the Indian and Eurasian plates. A stratum-bound series of sand volcanoes belonging to the Khari Nadi Formation(KNF) is exposed along the banks of Khari River. They separate the shallow marine deposits below and non-marine deposits above with their characteristic marine and paleosol trace fossil suites, respectively. Although a seismogenic origin has been much debated for the SSDS,the ichnofabric analysis of the sand-volcano-bearing stratum unequivocally points toward such an origin under a shallow seafloor condition. In addition to the sedimentary regime change from an open shallow-marine setting to a continental depositional environment concomitant with basinal uplift, the behavior of the burrowing crustaceans testifies to a syn-depositional development of a fault network associated with the fluidization, sand volcanism, and the resilience of the trace-producers in surviving those processes until the sedimentary regime change in the overlying strata. Although the ichno-sedimentological evidence apparently differs from the previous works that proposed a continuous base-level rise from the beginning of deposition of the Khari Nadi Formation up to the middle part of the overlying Chhasra Formation, the paleoseismic activity,its ichnologic signature, and the depositional regime change refer to a higher-resolution(i.e., lower-order)sequence-stratigraphic change causing a short-duration regression within a longer-duration cycle of base-level rise.

关键词： Sand volcano Seismite Ichnology Khari Nadi Formation Kutch Basin Kachchh Basin