检索结果-南通市图书馆

Unveiling osteoprotective potential of biologically active naringenin in rats with dexamethasone-induced osteoporosis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Digital chinese Medicine 2024年第2期7卷 171-183页

作者： Tejal r.Waykar satish K.Mandlik Deepa s.Mandlik Poona College of Pharmacy Bharati VidyapeethPune 411038India

Objective To investigate the protective effects of naringenin(NrG)against dexamethasone(DEX)-induced osteoporosis(OP)in *** Molecular docking of NrG was done with AutoDock Vina 1.2.0 ***-eight female Wistar rats were randomly divided into six groups(n=8 each):normal control(NC),DEX(7 mg/kg,i.m.),NrG-low(NrG-L;25 mg/kg,i.g.),NrG-medium(NrG-M;50 mg/kg,i.g.),NrG-high(NrG-H;100 mg/kg,i.g.),and alendronate(ALN;0.25 mg/d,i.g.)*** was induced by administering DEX once a week for five weeks in all groups except NC *** in the third week after the initial DEX administration,the rats in NrG-L,NrG-M,NrG-H,and ALN groups received the corresponding treatments daily for three weeks,while NC and DEX groups received no additional *** samples were collected at the end of the experiment for biochemical,bone turnover,antioxidant,lipid profile,and inflammatory cytokine *** bones underwent physical parameter testing and histopathological *** The molecular docking results illustrated that NrG docked with calcitonin(CT),lowdensity lipoprotein(LDL),bone morphogenetic protein(BMP),vascular endothelial growth factor(VEGF)receptor,forkhead transcription factors,and osteoprogenitor cells showed good binding *** rats administered with 25,50,and 100 mg/kg NrG,there was a significant enhancement in serum biochemical indices,characterized by a reduction in tartrate-resistant acid phosphatase(TrAP),parathyroid hormone(PTH),and an elevation in osteocalcin(OC)and CT levels(Prespectively).Despite no significant changes in thickness,weight,and length(P>0.05),there was a marked increase in bone mineral density(BMD)(Prespectively).Antioxidant enzyme markers showed significant upregulation,with higher glutathione,superoxide dismutase,and catalase,and a concurrent decrease in malondialdehyde(MDA)(Prespectively).The lipid profile also improved significa

关键词： Naringenin Osteoporosis Dexamethasone Bone turnover markers Inflammatory cytokines

First evidence for chiral wobbling of triaxial nuclei

在线全文

学校读者我要写书评

暂无评论

Nuclear science and Techniques 2024年第7期35卷 4-7页

作者： s.Frauendorf Department of Physics and Astronomy University of Notre DameNotre DameIN 46556USA

chirality(Greek“handiness”)is a property of many com-plex *** molecules exist in two forms,one being the mirror image of the *** for our hands,it is impossible to make the images identical by a suitable *** two forms are called left-handed and *** have the same binding energy,because the electro-magnetic interaction,which holds the molecule together,does not change under a *** properties that are insensitive to the geometry are also the *** different geometry is the reason why the left-handed form turns the polarization plane of transmitted light in one direction by some angle while the right-handed form turns it in the oppo-site direction by the same ***,the geometrical differences between the two species may have other *** two species of the carvon molecule shown in Fig.1 taste quite differently.

关键词： turns chiral mirror

Tribological behavior of lubricant-impregnated porous polyimide

在线全文

学校读者我要写书评

暂无评论

Friction 2024年第4期12卷 711-725页

作者： Jinbang LI Ningning ZHOU Janet s.s.WONG school of Mechanical Engineering and Mechanics Ningbo UniversityNingbo 315211China Beijing Key Laboratory of Long-life Technology of Precise rotation and Transmission Mechanisms Beijing Institute of Control EngineeringBeijing 100029China Department of Mechanical Engineering Imperial College LondonLondon SW72AZUK

Porous materials impregnated with lubricants can be used in conditions where limited lubricant is *** this work,three porous polyimides(PPI)with different densities were ***(PAO)impregnated PPI(iPPI)discs were rubbed against steel and sapphire *** operando observations of the iPPI-sapphire contacts show that oil is released under an applied load,forming a meniscus around *** at the outlet is created at high sliding *** amount of released oil increases with increasing PPI *** moduli,E*,estimated based on the actual contact size show that trapped oil in iPPIs contributes to load *** higher speeds,tribological rehydration of the contact occurs in low density iPPI,with that E*rises with *** high density PPIs,high speeds give a constantly high E*which is limited by the viscoelastic properties of the PPI network and possibly the rate of oil *** of iPPI-steel contacts is governed by the mechanical properties of the PPI,the flow of the lubricant,and the roughness of the PPI *** low-and medium-density(highly porous,high roughness)PPIs,large amount of oil is released,and lubrication is mainly via lubricant restricted in the contact in the pores and possibly tribological *** high density(low porosity)PPI,with lower roughness,hydrodynamic lubrication is achieved which gives the lowest *** results show that polymeric porous materials for effective lubrication require the optimization of its surface roughness,stiffness,oil flow,and oil retentions.

关键词： polyimide porous material friction mechanism polymer limited lubrication

A Novel Approach to Breast Tumor Detection: Enhanced speckle reduction and Hybrid Classification in Ultrasound Imaging

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第5期79卷 1875-1901页

作者： K.Umapathi s.shobana Anand Nayyar Judith Justin r.Vanithamani Miguel Villagómez Galindo Mushtaq Ahmad Ansari Hitesh Panchal Department of Biomedical Engineering KIT-Kalaignarkarunanidhi Institute of TechnologyCoimbatore641402India Graduate school Faculty of Information TechnologyDuy Tan UniversityDa Nang550000Viet Nam Department of Biomedical and Instrumentation Engineering Avinashilingam Institute for Home Science and Higher Education forWomenCoimbatore641043India UniversidadMichoacana de sanNicolás de HidalgoAvenida Francisco J.Múgica s/N Ciudad Universitaria MoreliaCP58030Mexico Department of Pharmacology and Toxicology College of PharmacyKing Saud UniversityRiyadh11451Saudi Arabia Department of Mechanical Engineering Gujarat Technological UniveristyNigam NagarChandkhedaAhmedabadGujarat382424India

Breast cancer detection heavily relies on medical imaging, particularly ultrasound, for early diagnosis and effectivetreatment. This research addresses the challenges associated with computer-aided diagnosis (CAD) of breastcancer fromultrasound images. The primary challenge is accurately distinguishing between malignant and benigntumors, complicated by factors such as speckle noise, variable image quality, and the need for precise segmentationand classification. The main objective of the research paper is to develop an advanced methodology for breastultrasound image classification, focusing on speckle noise reduction, precise segmentation, feature extraction, andmachine learning-based classification. A unique approach is introduced that combines Enhanced speckle reducedAnisotropic Diffusion (srAD) filters for speckle noise reduction, U-NET-based segmentation, Genetic Algorithm(GA)-based feature selection, and random Forest and Bagging Tree classifiers, resulting in a novel and efficientmodel. To test and validate the hybrid model, rigorous experimentations were performed and results state thatthe proposed hybrid model achieved accuracy rate of 99.9%, outperforming other existing techniques, and alsosignificantly reducing computational time. This enhanced accuracy, along with improved sensitivity and specificity,makes the proposed hybrid model a valuable addition to CAD systems in breast cancer diagnosis, ultimatelyenhancing diagnostic accuracy in clinical applications.

关键词： Ultrasound images breast cancer tumor classification segmentation deep learning lesion detection

synthesis of coral-like structures of Pr-Yb co-doped YIG: structural,optical, magnetic and antimicrobial properties

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 rare Earths 2024年第3期42卷 543-554,I0004页

作者： A.Fernandez Francisca P.Araujo Y.Guerra s.Castro-Lopes J.Matilla-Arias Idglan s.de Lima Edson C.silva-Filho Josy A.Osajima F.Guerrero r.Pena-Garcia Federal University of Piau Graduate Program in Materials Science and EngineeringTeresinaPIBrazil Federal rural University of Pernambuco Academic Unit of Cabo de Santo AgostinhoCabo de Santo AgostinhoPEBrazil Federal University of Piaui Department of PhysicTeresinaPBrazil Federal University of Pernambuco Graduate Program in Materials ScienceRecifePEBrazil University of Granma Departmentof Basic Sciences and Applied InformaticsFaculty of Technical SciencesBayamoCuba Federal University of Amazonas Department of PhysicManausAMBrazil Federal University of Pernambuco Department of PhysicRecifePEBrazil

Coral-like structures of the Y_(3-x)Pr_(x)Fe_(5-y)Yb_(y)O_(12),(0.00 ≤ x ≤ 0.04, 0.00 ≤ y ≤ 0.02) compound were synthesized using the sol-gel method. structural investigation certified the YIG cubic crystal structure formation, without any secondary phase. It is shown that, the relatively large ionic radius of the dopant cations results in an expansion of the lattice parameter, variations in the Iona-O-Iondangle, Iona-O,Iond-O and Ionc-O bond distances and decrease in the average crystallite size. Fourier transform infrared(FTIr) and raman measurements are essential to testify the single-phase formation of YIG crystal structure and are observed changes in the stretching and vibrational modes, respectively. The morphological study, energy dispersive spectroscopy(EDs) spectra and textural properties show corallike structures, peaks associated with Pr^(3+) and Yb^(3+) atoms and the effect of dopants on surface area,diameter, and pore volume, respectively. The optical analysis from diffuse reflectance spectra witnessed an increase in the optical gap band, a decrease in Urbach energy and blue shift in the charge transfer,correlated with the expansion of the unit cell due to the dopant's insertion in the YIG structure. A typical ferrimagnetic behavior is exhibited by the Y_(3-x)Pr_(x)Fe_(5-y)Yb_(y)O_(12)compound. The saturation magnetization(M_(s)), cubic anisotropy constant(K_(1)) and coercive field(H_(c)) increase with the Pr^(3+)cations content, as consequence of their magnetic nature and distribution around of Fe^(3+)ions due to the coexistence with the Yb^(3+). Finally, for the first time, antibacterial tests by mean of the direct contact method were performed for YIG co-doped with Pr^(3+)and Yb^(3+)and it is shown that, relatively high dosages of Pr^(3+) cations favored the activity against s. aureus, therefore, a new biological property for YIG doped with rare earths is presented.

关键词： Yttrium iron garnet(YIG) Coral-like structures rare earths Band gap energy Magnetic properties Antimicrobial properties

Neutrophils in Atlantic salmon(salmo salar L.)are MHC class II^(+)and secret IL-12p40 upon bacterial exposure

在线全文

学校读者我要写书评

暂无评论

Aquaculture and Fisheries 2024年第2期9卷 144-153页

作者： Gyri Teien Haugland Anita rønneseth Lene Gundersen Harald sæbøLunde Kaja Nordland Heidrun Inger Wergeland Department of Biological sciences Bergen High-Technology CentreUniversity of BergenBergen5020Norway

Antigen-presentation via major histocompatibility complex(MHC)to T cells is the key event to initiate adaptive immune *** teleosts,as in mammals,the main types of professional antigen-presenting cells(APCs)are dendritic cells(DCs),monocytes/macrophages,and B *** the current study,flow cytometry,immunostaining and qPCr have been used to show that neutrophils in the teleost fish Atlantic salmon(salmo salar L.)have antigen-presenting *** neutrophils were positive for MHC class II,CD83 and CD80/86,and upon in vitro bacterial exposure,gene expression analysis of purified neutrophils showed that IL-12p40,which is essential for proliferation of naïve T cells,was highly upregulated at both 6 and 24 h post bacterial *** on presence of MHC class II and upregulation of molecules involved in antigen presentation and T cell activation,we suggest that neutrophils in Atlantic salmon have potential to function as professional *** work makes an important basis for further exploring the potential of using neutrophils to develop new,targeted immunoprophylactic measures.

关键词： Granulocytes Antigen presenting cells Major histocompatibility complex T cell activation B cells CD83 CD80/86 MHC classⅡ

Enhancing fatigue performance of AZ31 magnesium alloy components fabricated by cold metal transfer-based wire arc directed energy deposition through LPB

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 Magnesium and Alloys 2024年第4期12卷 1638-1662页

作者： shambhu Kumar Manjhi srikanth Bontha A.s.s.Balan Department of Mechanical Engineering National Institute of Technology KarnatakaSurathkalSrinivasanagarMangaloreKarnataka 575025India

Cold Metal Transfer-Based Wire Arc Directed Energy Deposition(CMT-WA-DED)presents a promising avenue for the rapid fabrication of components crucial to automotive,shipbuilding,and aerospace ***,the susceptibility to fatigue of CMT-WA-DED-produced AZ31 Mg alloy components has impeded their widespread adoption for critical load-bearing *** this study,a comprehensive investigation into the fatigue behaviour of WA-DED-fabricated AZ31 Mg alloy has been carried out and compared to commercially available wrought AZ31 *** findings indicate that the as-deposited parts exhibit a lower fatigue life than wrought Mg alloy,primarily due to poor surface finish,tensile residual stress,porosity,and coarse grain microstructure inherent in the WA-DED *** Plasticity Burnishing(LPB)treatment is applied to mitigate these issues,which induce significant plastic deformation on the *** treatment resulted in a remarkable improvement of fatigue life by 42%,accompanied by a reduction in surface roughness,grain refinement and enhancement of compressive residual stress ***,during cyclic deformation,WA-DED specimens exhibited higher plasticity and dislocation density compared to both wrought and WA-DED+LPB specimens.A higher fraction of Low Angle Grain Boundaries(LAGBs)in WA-DED specimens contributed to multiple crack initiation sites and convoluted crack paths,ultimately leading to premature *** contrast,wrought and WA-DED+LPB specimens displayed a higher percentage of High Angle Grain Boundaries(HAGBs),which hindered dislocation movement and resulted in fewer crack initiation sites and less complex crack paths,thereby extending fatigue *** findings underscore the effectiveness of LPB as a post-processing technique to enhance the fatigue performance of WA-DED-fabricated AZ31 Mg alloy *** study highlights the importance of LPB surface treatment on AZ31 Mg components produced by CMT-WA-DED to remove surface d

关键词： Wire arc additive manufacturing AZ31 Mg alloy Low plasticity burnishing Low cycle fatigue test strain amplitude

The magnetosheath at high spectral resolution

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第1期8卷 234-246页

作者： K.D.Küntz D.Koutroumpa W.r.Dunn A.Foster F.s.Porter D.G.sibeck B.Walsh The Henry A.rowland Department of Physics and Astronomy Johns Hopkins University3701 San Martin DriveBaltimoreMD21218USA NAsA Goddard space Flight Center 8800 Greenbelt RoadGreenbeltMD 20771USA LATMOs-OVsQ CNRSUVSQ Paris-SaclaySorbonne Université11 Boulevard d’Alembert78280GuyancourtFrance Department of Physics and Astronomy University College LondonLondonUK The Centre for Planetary science at UCL/Birkbeck Gower StreetLondon WC1E 6BTUK Center for Astrophysics Harvard University&Smithsonian Institution60 Garden StreetCambridgeMA 02138USA Center for space Physics Boston University110 Cummington MallBostonMAUSA

While we eagerly anticipate sMILE’s(solar wind Magnetosphere Ionosphere Link Explorer)unprecedented X-ray observations of the Earth’s magnetosheath and the initiation of a new era of magnetospheric research,it seems appropriate to look ahead to the abilities of the next generation of astrophysics *** these,the Line Emission Mapper(LEM),a large aperture micro-calorimeter based mission,is currently planned to be able to observe the magnetosheath at high spectral resolution(~2 eV).With a field of view of~30′,LEM will allow higher spatial resolution and higher cadence measurement of the motion of a very small portion of the magnetopause over relatively short periods of time(multiple hours),complementing sMILE’s global ***’s strength is its spectral *** will be able to measure the abundance of a broad range of elements and ionization states,many of which are inaccessible to current in situ instruments,and will be able to separate the emission from the magnetosheath from the emission from the cosmic X-ray background using the difference in their relative velocities.

关键词： magnetosheath charge exchange solar wind abundances

Improvement of Deep Groove Ball Bearing’s Performance Using a Bionic Textured Inner race

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2021年第4期18卷 974-990页

作者： K.E.ch.Vidyasagar r.K.Pandey Dinesh Kalyanasundaram Center for Biomedical Engineering Indian Institute of Technology DelhiNew Delhi110016India Department of Biomedical Engineering College of EngineeringOsmania UniversityHyderabad500007India Department of Mechanical Engineering Indian Institute of Technology DelhiNew Delhi110016India Department of Biomedical Engineering All India Institute of Medical SciencesNew Delhi110029India

Micro-textured surfaces have improved the tribological performance of contact surfaces under lubricated conditions;however,not practiced due to manufacturing *** addition to simpler micro-pits or straight-trench type textures,sophisticated bioinspired textures on commercial radial ball bearings have been scarcely *** this work,Dendroaspis polylepis(Mamba snake)skin-type textures were fabricated on the inner race of FAG radial ball bearings using a nanosecond fiber laser *** the snake textures were primarily meant to enhance friction,the dimensions of the texture have been carefully chosen to improve the tribological performance under lubricated *** textured bearings were assembled and experimented at various rotational speeds and lightly loaded conditions to measure vibrational amplitude,frictional torque,and temperature *** to untextured(conventional)bearing,the snake-skin type textured bearings resulted in improved tribo-dynamic performance.

关键词： bionic texture radial ball bearing frictional torque vibration temperature