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Effect of solidification cooling rate on microstructure and tribology characteristics of Zn-4si alloy

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International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 362-373页

作者： F.Akbari M.Golkaram s.Beyrami G.shirazi k.Mantashloo R.Taghiabadi M.saghafi Yazdi I.Ansarian Department of Metallurgy and Material science Imam Khomeini International University(IKIU)Qazvin ***Iran

The main objective of this work was to modify the microstructure and enhance the tribological properties of a new Zn-4si al-loy through a high solidification cooling rate(sCR).According to the results,by increasing the sCR from 2.0 to 59.5℃/s the average size of primary si particles and that of the grains reduced from 76.1 and 3780μm to less than about 14.6 and 460μm,***-ing the sCR also enhanced the microstructural homogeneity,decreased the porosity content(by 50%),and increased the matrix hardness(by 36%).These microstructural changes enhanced the tribological *** instance,under the applied pressure of 0.5 MPa,an in-crease in the sCR from 2.0 to 59.5℃/s decreased the wear rate and the average friction coefficient of the alloy by 57%and 23%,*** wear mechanism was also changed from the severe delamination,adhesion,and abrasion in the slowly-cooled alloy to the mild tribolayer delamination/abrasion in the high-cooling-rate-solidified sample.

关键词： zinc-silicon alloy primary silicon solidification cooling rate tribology sliding wear

The autophagy protein Atg9 functions in glia and contributes to parkinsonian symptoms in a Drosophila model of Parkinson’s disease

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Neural Regeneration Research 2024年第5期19卷 1150-1155页

作者： shuanglong Yi Linfang Wang Margaret s.Ho shiping Zhang school of Life science and Technology ShanghaiTech UniversityShanghaiChina College of Life sciences University of Chinese Academy of SciencesBeijingChina

Parkinson’s disease is a progressive neurodegenerative disease characterized by motor deficits,dopaminergic neuron loss,and brain accumulation ofα-synuclein aggregates called Lewy *** in protein degradation pathways,such as autophagy,has been demonstrated in neurons as a critical mechanism for eliminating protein aggregates in Parkinson’s ***,it is less well understood how protein aggregates are eliminated in glia,the other cell type in the *** the present study,we show that autophagy-related gene 9(Atg9),the only transmembrane protein in the autophagy machinery,is highly expressed in Drosophila glia from adult *** from immunostaining and live cell imaging analysis reveal that a portion of Atg9 localizes to the trans-Golgi network,autophagosomes,and lysosomes in ***9 is persistently in contact with these *** glial atg9 reduces the number of omegasomes and autophagosomes,and impairs autophagic substrate *** suggests that glial Atg9 participates in the early steps of autophagy,and hence the control of autophagic ***,loss of glial atg9 induces parkinsonian symptoms in Drosophila including progressive loss of dopaminergic neurons,locomotion deficits,and glial *** findings identify a functional role of Atg9 in glial autophagy and establish a potential link between glial autophagy and Parkinson’s *** results may provide new insights on the underlying mechanism of Parkinson’s disease.

关键词： Atg9 autophagy glia Parkinson’s disease

Understanding Bonding Nature ofα-keggin Polyoxometalates[XW_(12)O_(40)]^(n−)(X=Al,si,P,s):A Generalized superatomic Perspective

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Energy & Environmental Materials 2024年第6期7卷 176-183页

作者： Rui Li Yulei shi Famin Yu Rui Wang Haitao Yan Boon k.Teo Zhigang Wang Department of Physics Capital Normal UniversityBeijing 100048China key Laboratory of Material simulation Methods&software of Ministry of Education College of PhysicsJilin UniversityChangchun 130012China Institute of Atomic and Molecular Physics Jilin UniversityChangchun 130012China state key Laboratory for Physical Chemistry of solid surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Institute of Theoretical Chemistry College of ChemistryJilin UniversityChangchun 130012China

α-keggin polyoxometalates(POMs)[XW_(12)O_(40)]^(n−)(X=Al,si,P,s)are widely used in batteries owing to their remarkable redox ***,the mechanism underlying the applications appears inconsistent with the widely accepted covalent bonding ***,first-principles calculations show that XW_(12)are core–shell structures composed of a shell and an XO_(4)^(n−)core,both are stabilized by covalent ***,owing to the presence of a substantial number of electrons in W_(12)O_(36)shell,the frontier molecular orbitals of XW_(12)are not only strongly delocalized but also exhibit superatomic properties with high-angular momentum electrons that do not conform to the Jellium *** analysis indicates that energetically high lying filled molecular orbitals(MOs)have reached unusually high-angular momentum characterized by quantum number k or higher,allowing for the accommodation of numerous *** attribute confers strong electron acceptor ability and redox activity to XW_(12).Moreover,electrons added to XW_(12)still occupy the k orbitals and will not cause rearrangement of the MOs,thereby maintaining the stability of these *** findings highlight the structure–activity relationship and provide a direction for tailor-made POMs with specific properties at atomic level.

关键词： first principles molecular orbital polyoxometalate redox activity superatom

In vivo and in vitro study of resorbable magnesium wires for medical implants:Mg purity,surface quality,Zn alloying and polymer coating

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Journal of Magnesium and Alloys 2024年第6期12卷 2472-2488页

作者： k.Tesar J.Luňácková M.Jex M.Žaloudková R.Vrbová M.Bartoš P.klein L.Vištejnová J.Dušková E.Filová Z.sucharda M.steinerová s.Habr k.Balík A.singh Department of Materials Faculty of Nuclear Sciences and Physical EngineeringCzech Technical University in PragueTrojanova 13Prague 12000Czech Republic Institute of Physics Czech Academy of SciencesNa Slovance 2Prague 18221Czech Republic Institute of Dental Medicine First Faculty of MedicineCharles University and General University Hospital in PragueKaterinská32Prague 12801Czech Republic Department of Physics Faculty of Nuclear Sciences and Physical EngineeringCzech Technical University in PragueBrehová7Prague 11519Czech Republic Department of Composites and Carbon Materials Institute of Rock Structure and MechanicsCzech Academy of SciencesV Holešovickách 41Prague 18209Czech Republic Institute of Anatomy First Faculty of MedicineCharles UniversityU Nemocnice 3Prague 12800Czech Republic Biomedical Center Faculty of Medicine in PilsenCharles UniversityAlej Svobody 76Pilsen 32300Czech Republic Department of Pathological Physiology Faculty of Medicine in PilsenCharles UniversityAlej Svobody 7632300 PilsenCzech Republic Department of Histology and Embryology Faculty of Medicine in PilsenCharles UniversityAlej Svobody 7632300 PilsenCzech Republic Institute of Pathology First Faculty of MedicineCharles University and General University Hospital in PragueStudnickova 2Prague 12800Czech Republic Department of Biomaterials and Tissue Engineering Institute of PhysiologyCzech Academy of SciencesVidenska 1083Prague 14200Czech Republic Research Center for structural Materials National Institute for Materials Science1-2-1 SengenTsukuba 305-0047Japan

Magnesium is an excellent material in terms of biocompatibility and its corrosion products can serve as an active source for new bone ***,localized corrosion and H_(2)generation limit the potential of Mg-based *** low-alloyed Mg-Zn wires can strongly reduce problems with large H_(2)bubbles and improve the mechanical properties considerably while maintaining excellent long-term *** pickling and a polymer coating can be effectively used to lower the rate of in vivo *** this work,microstructural,mechanical,and in vitro characterization of 250μm and 300μm extruded wires made from ultra-pure Mg,commercially pure Mg,Mg-0.15Zn,Mg-0.4Zn and Mg-1Zn was ***,Mg-0.4Zn wires together with a variant coated with a copolymer of L-lactide andε-caprolactone were tested in vivo on artificially damaged Wistar rat *** on the observed Mg-induced osteogenesis,polymer-coated Mg wires with a small addition of Zn are a perspective material for bone-support applications,such as cerclage and fixation wires.

关键词： Magnesium Resorbable Mg wire Mg-Zn implant degradation Biocompatibility study Zn grain boundary segregation

The Ca^(2+)-sensing receptor and the pocketome:comparing nature's complexity with human intervention in receptor modulation

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signal Transduction and Targeted Therapy 2024年第8期9卷 3153-3154页

作者： Edda s.F.Matthees Carsten Hoffmann Institut fur Molekulare Zellbiologie CMB-Center for Molecular BiomedicineUniversitatsklinikum JenaHans-Knoll StraBe 2D-07745 JenaGermany Friedrich-schiller-Universitat Jena Hans-KnollStraBe2D-07745 JenaGermany

In a recent paper published in Nature,the relatively understudied Ca^(2+)-sensing,receptor(CasR)within the Gprotein-coupled receptor(GPCR)family C,gained attention due to pioneering research led by Georgios skiniotis ... 详细信息

关键词： stanford gained skin

Exploring the effects of taurolidine on tumor weight and microvessel density in a murine model of osteosarcoma

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Oncology Research 2024年第7期32卷 1163-1172页

作者： LIsANNE k.A.NEIJENHUIs LEUTA L.NAUMANN sONIA A.M.FERkEL sAMUEL J.s.RUBIN sTEPHAN ROGALLA Division of Gastroenterology and Hepatology Department of MedicineSchool of MedicineStanford UniversityStanford94305USA Department of surgery Leiden University Medical CenterLeiden2333 ZAThe Netherlands Centre for Human Drug Research Leiden2333 CLThe Netherlands Department of General VisceralVascular and Thoracic SurgeryCharite University Medicine BerlinBerlin10117Germany

Background:Osteosarcoma is the most common malignant primary bone *** prognosis for patients with disseminated disease remains very poor despite recent advancements in ***,current treatment regimens bear a signiﬁcant risk of serious side ***,there is an unmet clinical need for effective therapies with improved safety proﬁ*** is an antibacterial agent that has been shown to induce cell death in different types of cancer cell ***:In this study,we examined both the antineoplastic and antiangiogenic effects of taurolidine in animal models of osteosarcoma.k7M2 murine osteosarcoma cells were injected,both intramuscular and intraperitoneal,into 60 BALB/c mice on day *** were then randomized to receive treatment with taurolidine 2%(800 mg/kg),taurolidine 1%(400 mg/kg),or NaCl 0.9%control for seven days by intravenous or intraperitoneal ***:After 35 days,mice were euthanized,and the tumors were harvested for *** mice were excluded from the analysis due to *** weight was signiﬁcantly lower in the 2%taurolidine intraperitoneal treatment group from day 9 to 21,consistent with elevated mortality in this *** tumor weight was signiﬁcantly lower in the 1%(p=0.003)and 2%(p=0.006)intraperitoneal taurolidine treatment groups compared to the *** antineoplastic effects were observed on intramuscular tumors or for intravenous administration of *** were no signiﬁcant differences in microvessel density or mitotic rate between treatment *** body weight and elevated mortality in the 2%taurolidine intraperitoneal group suggest that the lower 1%dose is ***:In conclusion,there is no evidence of antiangiogenic activity,and the antitumor effects of taurolidine on osteosarcoma observed in this study are ***,its toxic proﬁle grants further *** these observations,further research is necessary to

关键词： Osteosarcoma Taurolidine Cancer treatment Chemotherapy Murine models

Impact of Fin Arrangement on Heat Transfer and Melting Characteristics of Phase Change Material

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Journal of Thermal science 2024年第2期33卷 435-456页

作者： Arun UNIYAL Yogesh k.PRAJAPATI Department of Mechanical Engineering National Institute of Technology UttarakhandSrinagar(Garhwal)246174India Department of Mechanical Engineering BIT SindriDhanbadJharkhand828123India

Present work investigates the heat transfer and melting behaviour of phase change material(PCM) in six enclosures(enclosure-1 to 6) filled with paraffin *** enclosures are equipped with distinct arrangements of the fins while keeping the fin's surface area equal in each *** analysis has been presented to recognize the suitable fin arrangements that facilitate improved heat transfer and melting rate of the *** wall of the enclosure is maintained isothermal for the temperature values 335 k,350 k and 365 *** length of the enclosure including fins is ranging between 0 and *** have been illustrated through the estimation of important performance parameters such as energy absorbing capacity,melting rate,enhancement ratio,and Nusselt *** has been found that melting time(to melt 100% of the PCM) is 60.5%less in enclosure-2(with two fins of equal length) as compared to the enclosure-1,having no *** the fin surface area equal,if the longer fin is placed below the shorter fin(enclosure-3),melting time is further decreased by 14.1% as compared to ***,among all the configurations,enclosure-6 with wire-mesh fin structure exhibits minimum melting time which is 68.4% less as compared to the *** on the findings,it may be concluded that fins are the main driving agent in the enclosure to transfer the heat from heated wall to the *** design and positioning of the fins improve the heat transfer rate followed by melting of the PCM in the entire area of the *** of the favourable vortices and natural convection current in the enclosure accelerate the melting phenomenon and help to reduce charging time.

关键词： phase change material enclosure fin melting fraction energy storage heat transfer

Feeding ecology and interactions with mammal hosts in a symbiotic genus of birds(Buphagus spp.)in Namibia

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Avian Research 2024年第3期15卷 336-344页

作者： Michael s.Lukubwe Daniel Velarde-Garcéz Fernando sequeira susana Lopes Adrian J.F.k.Craig Vanessa A.Mata Department of Zoology and Entomology Rhodes UniversityMakhandaSouth Africa Department of Wildlife Management and Tourism studies University of NamibiaKatima Mulilo CampusNamibia Departamento de Biologia Faculdade de CiênciasUniversidade do PortoPortoPortugal CIBIO Centro de Investigação em Biodiversidade e Recursos GenéticosInBIO Laboratório AssociadoCampus de VairãoVairãoPortugal BIOPOLIs Program in Genomics Biodiversity and Land PlanningCIBIOCampus de VairãoVairãoPortugal

As the sole obligate symbiotic birds in Africa,oxpeckers offer a unique model for studying symbiotic *** to the multitrophic level they occupy and the context dependent foraging behavior they exhibit,the type of symbiotic relationship can be *** addition to providing a cleaning service to the host by removing ticks,oxpeckers frequently feed on blood,mucus,and saliva,inflicting potential damage on the ***,we used DNA metabarcoding on faecal samples to analyze the taxonomic composition of the trophic interactions of the Yellow-billed Oxpecker(Buphagus africanus)and Red-billed Oxpecker(***)in northeastern *** contrast to conventional methods,DNA metabarcoding allows for a detailed identification of dietary resources encompassing both mammal hosts and consumed arthropods within the same *** this information,we examined differences in the diet composition between oxpecker species and localities,as well as the co-occurrence between host and arthropod *** findings revealed that oxpeckers predominantly source their diet from mammals,ticks,and flies;however,ticks and flies rarely co-occur in the diet of an *** observed variability among individuals in their feeding ecology,which is strongly correlated with locality and,to a lesser extent,with the mammal *** noted a high degree of mobility between hosts within relatively short periods,with 32%of the samples showing traces of at least two mammal *** study illustrates the dynamic foraging behavior of these specialized symbiotic birds,shedding light on their potential role in pest control services and disease transmission.

关键词： Commensalism Diet DNA metabarcoding Oxpeckers Parasitism Trophic ecology

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

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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