检索结果-南通市图书馆

semantic segmentation of Lumbar vertebrae Using Meijering U-Net(MU-Net)on spine Magnetic Resonance Images

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & sciences 2025年第1期142卷 733-757页

作者： Lakshmi s v v shiloah Elizabeth Darmanayagam sunil Retmin Raj Cyril Department of Computer science and Engineering College of Engineering GuindyAnna UniversityChennai600025India Department of Information Technology Madras Institute of TechnologyAnna UniversityChrompetChennai600044India

Lower back pain is one of the most common medical problems in the world and it is experienced by a huge percentage of people *** to its ability to produce a detailed view of the soft tissues,including the spinal cord,nerves,intervertebral discs,and vertebrae,Magnetic Resonance Imaging is thought to be the most effective method for imaging the *** semantic segmentation of vertebrae plays a major role in the diagnostic process of lumbar *** is difficult to semantically partition the vertebrae in Magnetic Resonance Images from the surrounding variety of tissues,including muscles,ligaments,and intervertebral discs.U-Net is a powerful deep-learning architecture to handle the challenges of medical image analysis tasks and achieves high segmentation *** work proposes a modified U-Net architecture namely MU-Net,consisting of the Meijering convolutional layer that incorporates the Meijering filter to perform the semantic segmentation of lumbar vertebrae L1 to L5 and sacral vertebra ***-colour mask images were generated and used as ground truth for training the *** work has been carried out on 1312 images expanded from T1-weighted mid-sagittal MRI images of 515 patients in the Lumbar spine MRI Dataset publicly available from Mendeley *** proposed MU-Net model for the semantic segmentation of the lumbar vertebrae gives better performance with 98.79%of pixel accuracy(PA),98.66%of dice similarity coefficient(DsC),97.36%of Jaccard coefficient,and 92.55%mean Intersection over Union(mean IoU)metrics using the mentioned dataset.

关键词： Computer aided diagnosis(CAD) magnetic resonance imaging(MRI) semantic segmentation lumbar vertebrae deep learning U-Net model

Unlocking hypoglycemia–associated brain microvascular dysfunction:critical insights from proteomic analysis

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

Neural Regeneration Research 2025年第6期20卷 1707-1708页

作者： siva s.v.P.sakamuri Anil sakamuri Department of Chemistry Auburn University at MontgomeryMontgomeryALUSA vascular Biology Center and Department of Medicine Medical College of Georgia at Augusta UniversityAugustaGAUSA

Hypoglycemia-a critical complication linked to worsened brain function in diabetic subjects:Hypoglycemia is characterized by a decline in circulatory glucose levels below sta nda rd physiological *** hypoglycemia,classified as level 1 hypoglycemia,is defined by blood glucose levels below 70 mg/dL and can be effectively addressed through carbohydrate *** hypoglycemia,denoted by blood glucose levels less than 54 mg/dL,poses a life-threatening risk if left *** with type 1 and type 2 diabetes undergoing insulin treatment are particularly susceptible to hypoglycemia due to impaired counterregulatory mechanisms.

关键词： impaired intake critical

A comprehensive investigation on nonlinear vibration and bending characteristics of bio-inspired helicoidal laminated composite structures

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 81-100页

作者： s.sAURABH R.KIRAN D.sINGH R.vAIsH v.s.CHAUHAN school of Mechanical and Materials Engineering Indian Institute of Technology Mandi

Bio-inspired helicoidal composite laminates, inspired by the intricate helical structures found in nature, present a promising frontier for enhancing the mechanical properties of structural designs. Hence, this study provides a comprehensive investigation into the nonlinear free vibration and nonlinear bending behavior of bio-inspired composite plates. The inverse hyperbolic shear deformation theory(IHsDT) of plates is employed to characterize the displacement field, with the incorporation of Green-Lagrange nonlinearity. The problem is modeled using the C0finite element method(FEM), and an in-house code is developed in the MATLAB environment to solve it numerically. various helicoidal layup configurations including helicoidal recursive(HR), helicoidal exponential(HE), helicoidal semi-circular(Hs), linear helicoidal(LH), and Fibonacci helicoidal(FH)with different layup sequences and quasi-isotropic configurations are studied. The model is validated, and parametric studies are conducted. These studies investigate the effects of layup configurations, side-to-thickness ratio, modulus ratios, boundary conditions, and loading conditions at different load amplitudes on the nonlinear vibration and nonlinear bending behaviors of bio-inspired composite plates. The results show that the laminate sequence exerts a substantial impact on both nonlinear natural frequencies and nonlinear bending behaviors. Moreover, this influence varies across different side-to-thickness ratios and boundary conditions of the bio-inspired composite plate.

关键词：

Experimental Investigations of the Three-DimensionalFlow in a Large Deflection Turbine Cascade with Tip Clearance

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal science 1998年第3期7卷 149-164页

作者： M.Govardhan s.s.s.R.K.sastri v.s.vishnubhotla ThermalurbomachinesLab DepartmentofMechanicalEngineeringIndianInstituteofTechnologyMadrasChennai600036IndiaThermalurbomachinesLabDepartmentofMechanicalEngineeringIndianInstituteofTechnologyMadrasChennai600036IndiaThermalurbomachinesLabDepartment

Results obtained from an experbontal study of the threedimensional flow survey within and exit of a large defiection linear turbine cascade are presented for a tip clearance levels of 0.08, 1.5, 3.0 percent of chord and compared with the help of boundary layer probes and that within and exit of a blade passage was done with a miniaturised five hole probe. End wall and blade tip surface static pressures were also obtained, in addition to flow visualisation studies. A strong horse-shoe vortex forms in front of the leading edge for zero clearance whereas this vortex does not appear for 3 percent clearance indicating that for large clearance the pressure forces have dominating infiuence than the viscous forces. In addition to normally known clearance vortex, a small tip separation vortex was noticed on the blade tip surface inside the tip gap. Due to the area contraction caused by the tip separation vortex, the fluid movign towards the tip gap from the pressure side is accelerated. Downstream of the vortex, the endwall pressure increases due to flow mixing. Both vortices increase in size and strength along the chord. The miring is incomplete in the aft portion of the blade. The tip gap velocity profiles exhibit wak like characteristics especially at axial positions where the mixing is incomplete. The passage vortex in the present investigations did not diminish with increase in clearance. The discharge coefhcient and the total pressure loss coefficient within the tip gap show similar tendency with lower values near the leading and trailing edge regions.

关键词： turbine cascade tip clearance vortex tip separation vortex horse-shoe vor-tex total pressure loss coefficient discharge coefficient

Brain-derived neurotrophic factor signaling in the neuromuscular junction during developmental axonal competition and synapse elimination

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第2期20卷 394-401页

作者： Josep Tomàs víctor Cilleros-Mañé Laia Just-Borràs Marta Balanyà-segura Aleksandra Polishchuk Laura Nadal Marta Tomàs Carolina silvera-simón Manel M.santafé Maria A.Lanuza Unitat d’Histologia i Neurobiologia(UHNeurob) Facultat de Medicina i Ciències de la SalutUniversitat Rovira i VirgiliReusSpain

During the development of the nervous system,there is an overproduction of neurons and *** competition between neighboring nerve endings and synapses performing different activity levels leads to their elimination or *** have extensively studied the involvement of the brain-derived neurotrophic factor-Tropomyosin-related kinase B receptor neurotrophic retrograde pathway,at the neuromuscular junction,in the axonal development and synapse elimination process versus the synapse *** purpose of this review is to describe the neurotrophic influence on developmental synapse elimination,in relation to other molecular pathways that we and others have found to regulate this *** particular,we summarize our published results based on transmitter release analysis and axonal counts to show the different involvement of the presynaptic acetylcholine muscarinic autoreceptors,coupled to downstream serine-threonine protein kinases A and C(PKA and PKC)and voltage-gated calcium channels,at different nerve endings in developmental *** dynamic changes that occur simultaneously in several nerve terminals and synapses converge across a postsynaptic site,influence each other,and require careful studies to individualize the mechanisms of specific *** describe an activity-dependent balance(related to the extent of transmitter release)between the presynaptic muscarinic subtypes and the neurotrophin-mediated TrkB/p75NTR pathways that can influence the timing and fate of the competitive interactions between the different axon *** downstream displacement of the PKA/PKC activity ratio to lower values,both in competing nerve terminals and at postsynaptic sites,plays a relevant role in controlling the elimination of supernumerary ***,calcium entry through L-and P/Q-subtypes of voltage-gated calcium channels(both channels are present,together with the N-type channel in developing nerve terminals)contributes to red

关键词： acetylcholine release adenosine receptors axonal competition brain-derived neurotrophic factor calcium channels motor end-plate muscarinic acetylcholine receptors postnatal synapse elimination serine kinases tropomyosin-related kinase receptorB

High-precision inverse potentials for neutron-proton scattering using piece-wise smooth Morse functions

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第10期48卷 201-213页

作者： Ayushi Awasthi Arushi sharma Ishwar Kant O.s.K.s.sastri Department of Physics and Astronomical science Central University of Himachal PradeshDharmshala176215India

The aim of this study is to construct inverse potentials for various ℓ-channels of neutron-proton scattering using a piece-wise smooth Morse function as a *** phase equations for single-channel states and the coupled equations of multi-channel scattering are solved numerically using the 5^(th) order Runge-kutta *** employ a piece-wise smooth reference potential comprising three Morse functions as the initial *** a machine learning-based genetic algorithm,we optimize the model parameters to minimize the mean-squared error between simulated and anticipated phase *** approach yields inverse potentials for both single and multichannel scattering,achieving convergence to a mean-squared error≤10^(-3).The resulting scattering lengths"a_(0)"and effective ranges"r"for ^(3)s_(1) and ^(1)s_(0) states,expressed as[a_(0),r],are found to be[5.445(5.424),1.770(1.760)]and[–23.741(–23.749),2.63(2.81)],respectively;these values are in excellent agreement with experimental ***,the calculated total scattering cross-sections are highly consistent with their experimental counterparts,having a percentage error of less than 1%.This computational approach can be easily extended to obtain interaction potentials for charged particle scattering.

关键词： inverse potentials neutron-proton scattering piece-wise smooth Morse function phase function method reference potential approach genetic algorithm

Beneficiation of coal using supercritical water and carbon dioxide extraction:sulfur removal

在线全文

学校读者我要写书评

暂无评论

International Journal of Coal science & Technology 2021年第4期8卷 717-726页

作者： Matthew J.DeCuir Ram B.Gupta Bhima sastri Department of Chemical and Life science Engineering Virginia Commonwealth UniversityRichmondVA 23284-3068USA Office of Fossil Energy U.S.Department of Energy19901 Germantown RoadGermantownMD 20874-1290USA

This work explores the use of carbon dioxide,water,and their mixtures as solvent for the precombustion beneficiation of raw coal without using any toxic mineral acids in the temperature range of 200-400℃.The fluid polarity,ionic constant,and supercritical point can be adjusted by H_(2)O/CO_(2)ratio and *** carbon dioxide to hydrothermal fluid also increases the ionization by forming carbonic *** with supercritical fluids have several benefits including enhanced mass transport,ease of separation and recycle,wide range of extractive capability and tunability,better inherent safety,and in the case of carbon dioxide and water-low cost.A semi-continuous extraction system was designed and built in which pressure,temperature and the relative flow rates of CO_(2)and H_(2)O can be *** powder is kept in a packed bed and the extraction is carried out at 143 bar *** sulfur as a model heteroatom,extractive efficiency is examined as a function of the temperature,fluid composition,fluid flow,and extraction *** results indicate that carbon dioxide,water,and supercritical water-carbon dioxide(scWC)all can effectively extract about 50%of total sulfur from bituminous coal in 1 *** above 350℃decreased effectiveness,and extraction above the supercritical point of pure water caused hydrothermal *** extraction may provide necessary control to prevent organic dissolution while removing sulfur.

关键词： Coal supercritical sulfur Beneficiation Cleaning Extraction

Prolonged intermittent theta burst stimulation restores the balance between A_(2A)R-and A_(1)R-mediated adenosine signaling in the 6-hydroxidopamine model of Parkinson's disease

维普期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第7期20卷 2053-2067页

作者： Milica Zeljkovic Jovanovic Jelena stanojevic Ivana stevanovic Milica Ninkovic Tihomir v.Ilic Nadezda Nedeljkovic Milorad Dragic Laboratory for Neurobiology Department of General Physiology and BiophysicsFaculty of BiologyUniversity of BelgradeBelgradeSerbia Medical Faculty of Military Medical Academy University of DefenceBelgradeSerbia

An imbalance in adenosine-mediated signaling,particularly the increased A_(2A)R-mediated signaling,plays a role in the pathogenesis of Parkinson's *** therapeutic approaches fail to alter disease progression,demonstrating the need for novel approaches in *** transcranial magnetic stimulation is a non-invasive approach that has been shown to improve motor and non-motor symptoms of Parkinson's ***,the underlying mechanisms of the beneficial effects of repetitive transcranial magnetic stimulation remain *** purpose of this study is to investigate the extent to which the beneficial effects of prolonged intermittent theta burst stimulation in the 6-hydroxydopamine model of experimental parkinsonism are based on modulation of adenosine-mediated *** with unilateral 6-hydroxydopamine lesions underwent intermittent theta burst stimulation for 3 weeks and were tested for motor skills using the Rotarod ***,quantitative reverse transcription polymerase chain reaction,immunohistochemistry,and biochemical analysis of components of adenosine-mediated signaling were performed on the synaptosomal fraction of the lesioned caudate *** intermittent theta burst stimulation improved motor symptoms in 6-hydroxydopamine-lesioned animals.A 6-hydroxydopamine lesion resulted in progressive loss of dopaminergic neurons in the caudate *** with intermittent theta burst stimulation began 7 days after the lesion,coinciding with the onset of motor *** treatment with prolonged intermittent theta burst stimulation,complete motor recovery was *** improvement was accompanied by downregulation of the e N/CD73-A_(2A)R pathway and a return to physiological levels of A_(1)R-adenosine deaminase 1 after 3 weeks of intermittent theta burst *** results demonstrated that 6-hydroxydopamine-induced degeneration reduced the expression of A_(1)R and elevated the expression of A_(2A)***

关键词： A_(1)R A_(2A)R adenosine receptors adenosine ecto-5′-nucleotidase intermittent theta burst stimulation non-invasive brain stimulation Parkinson's disease purinergic signalling

Improved strength and ductility of high alloy containing Al–12Zn–3Mg–2.5Cu alloy by combining non-isothermal step rolling and cold rolling

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2017年第2期24卷 179-185页

作者： v.v.Ravikumar s.Kumaran Department of Metallurgical and Materials Engineering National Institute of TechnologyTamil Nadu 620015India

Al-12Zn-3Mg-2.5Cu alloy was prepared using a liquid metallurgy route under the optimized conditions. A sample cut from the ingot was rolled non-isothermally from 400℃ to 100℃ in 100℃ steps, with 15% reduction in thickness; it was then cold rolled isothermally at room temperature for 85% reduction. The cold-rolled alloys were characterized by electron microscopy, hardness test, and tensile test to elucidate their structural evolution and evaluate their mechanical behavior. In the results, the cast alloy consists of a-aluminum and various intermetallic compounds. These compounds are segregated along the grain boundaries, which makes the alloy difficult to roll at room tem- perature. The combined effect of non-isothermal step rolling and cold rolling results in the nano/microsized compounds distributed uniformly in the matrix. The hardness is substantially increased after rolling. This increase in hardness is attributed to the ultra-fine grain size, fine-scale intermetallic compounds, and structural defects （e.g., dislocations, stacking faults, and sub-grains）. The ultimate tensile strength of the rolled alloy is approximately 628 MPa with 7% ductility.

关键词： aluminum zinc magnesium copper alloys non-isothermal cold rolling mechanical properties intermetallic compounds struc-ture defects