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Challenges and opportunities in the production of magnesium parts by directed energy deposition processes

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Journal of Magnesium and Alloys 2024年第5期12卷 1663-1686页

作者： gürel Cam Ali günen Iskenderun Technical University Faculty of Engineering and Natural SciencesDepartment of Mechanical Engineering31200 Iskenderun-HatayTurkey Iskenderun Technical University Faculty of Engineering and Natural SciencesDepartment of Metallurgy and Materials Engineering31200 Iskenderun-HatayTurkey

Mg-alloys have gained considerable attention in recent years for their outstanding properties such as lightweight,high specific strength,and corrosion resistance,making them attractive for applications in medical,aerospace,automotive,and other transport ***,their widespread application is hindered by their low formability at room temperature due to limited slip *** Mg-alloys have low mechanical properties due to the presence of casting defects such as porosity and anisotropy in addition to the high *** casting methods benefit from established process optimization techniques for these problems,additive manufacturing methods are increasingly replacing casting methods in Mg alloys as they provide more precise control over the microstructure and allow specific grain orientations,potentially enabling easier optimization of anisotropy properties in certain *** metal additive manufacturing(MAM)technology also results in some manufacturing defects such as inhomogeneous microstructural evolution and porosity and additively manufactured Mg alloy parts exhibit lower properties than the wrought parts,they in general exhibit superior properties than the cast ***,MAM is a promising technique to produce Mg alloy *** energy deposition processes,particularly wire arc directed energy deposition(WA-ded),have emerged as an advantageous additive manufacturing(AM)technique for metallic materials including magnesium alloys,offering advantages such as high deposition rates,improved material efficiency,and reduced production costs compared to subtractive ***,the inherent challenges associated with magnesium,such as its high reactivity and susceptibility to oxidation,pose unique hurdles in the application of this *** review paper delves into the progress made in the application of ded technology to Mg-alloys,its challenges,and ***,the predominant imperfections,notably inhomo

关键词： Additive manufacturing ded processes Arc-ded Wire arc additive manufacturing(WAAM) 3-d printing High deposition rate

Recent research in mechanical properties of geopolymer-based ultrahigh-performance concrete:A review

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defence Technology（防务技术） 2024年第2期32卷 67-88页

作者： g.Murali division of Research&Innovation Uttaranchal UniversityDehradun 248007India

due to the growing need for sustainable and ultra-high-strength construction materials,scientists have created an innovative ultra-high-performance concrete called geopolymer based ultra-highperformance concrete(gUHPC).Besides,in the last few decades,there have been a lot of explosions and ballistic attacks around the world,which have killed many civilians and fighters in border *** this context,this article reviews the fresh state and mechanical properties of ***,the ingredients of gUHPC and fresh properties such as setting time and flowability are briefly ***,the review of compressive strength,flexure strength,tensile strength and modulus of elasticity of fibrous ***,the blast and projectile impact resistance performance was ***,the microstructural characteristics were reviewed using the scanning electron microscope and X-ray Powder *** review outcome reveals that the mechanical properties were increased when 30%silica fume was added to a higher dose of steel fibre to improve the microstructure of *** is hypothesized that the brittleness of gUHPC was mitigated by adding 1.5%steel fibre reinforcement,which played a role in the decrease of contact explosion cratering and *** the need for cement in gUHPC was a key factor in the review,indicating a promising potential for lowering carbon ***,gUHPC research is still in its early stages,so more study is required before its full potential can be utilized.

关键词： Mechanical properties Blast Projectile impact Fibre geopolymer Silica fume Alkaline activators

Risk factors for long COVId in children and adolescents:a systematic review and meta-analysis

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World Journal of Pediatrics 2024年第2期20卷 133-142页

作者： daniel g.Rayner elaine Wang Cloris Su Om d.patel Stephanie Aleluya Alessandra giglia evelyn Zhu Maha Siddique department of Health Research Methods Evidenceand ImpactFaculty of Health SciencesMcMaster University1280 Main St WHamiltonONL8S 4K1Canada Faculty of Health Sciences McMaster University1280 Main St WHamiltonON L8S 4K1Canada Faculty of Science McMaster University1280 Main St WHamiltonONL8S 4K1Canada

Background The long-term sequelae of COVId-19 in children and adolescents remain poorly understood and *** systematic review and meta-analysis sought to summarize the risk factors for long COVId in the pediatric *** We searched six databases from January 2020 to May 2023 for observational studies reporting on risk factors for long COVId or persistent symptoms those were present 12 or more weeks post-infection using multivariable regression *** registries,reference lists of included studies,and preprint servers were hand-searched for relevant ***-effects meta-analyses were conducted to pool odds ratios for each risk *** study risk of bias was rated using QUIPS,and the gRAde framework was used to assess the certainty of evidence for each unique *** Sixteen observational studies(N=46,262)were included,and 19 risk factors were amenable to *** moderate certainty in the evidence,age(per 2-year increase),allergic rhinitis,obesity,previous respiratory diseases,hospitalization,severe acute COVId-19,and symptomatic acute COVId-19 are probably associated with an increased risk of long *** sex,asthma,comorbidity,and heart diseases may be associated with an increased risk of long COVId,and Asian and Black races may be associated with a decreased risk of long *** did not observe any credible subgroup effects for any risk *** The current body of literature presents several compelling risk factors for the development of long COVId in the pediatric *** research is necessary to elucidate the pathophysiology of long COVId.

关键词： COVId-19 Long COVId Post-acute COVId-19 syndrome Pediatrics Risk factors

miniSCIdOM: a scintillator-based tomograph for volumetric dose reconstruction of single laser-driven proton bunches

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High Power Laser Science and engineering 2024年第2期12卷 41-50页

作者： A.Corvino M.Reimold e.Beyreuther F.-e.Brack F.Kroll J.pawelke J.d.Schilz M.Schneider U.Schramm M.e.P.Umlandt K.Zeil T.Ziegler J.Metzkes-Ng Helmholtz-Zentrum dresden–Rossendorf DresdenGermany Technische Universität dresden DresdenGermany OncoRay–National Center for Radiation Research in Oncology Faculty of Medicine and University Hospital Carl Gustav CarusTUD Dresden University of TechnologyHelmholtz-Zentrum Dresden–RossendorfDresdenGermany Current affiliation:Institut Curie UniversitéPSLCNRS UMR3347OrsayFrance Current affiliation:Universitätsklinikum Freiburg FreiburgGermany

Laser plasma accelerators(Lpas)enable the generation of intense and short proton bunches on a micrometre scale,thus offering new experimental capabilities to research fields such as ultra-high dose rate radiobiology or material *** spectrally broadband,laser-accelerated proton bunches allow for tailored volumetric dose deposition in a sample via single bunches to excite or probe specific sample *** rising number of such experiments indicates a need for diagnostics providing spatially resolved characterization of dose distributions with volumes of approximately 1 cm^(3) for single proton bunches to allow for fast online *** we present the scintillator-based miniSCIdOM detector for online single-bunch tomographic reconstruction of dose distributions in volumes of up to approximately 1 cm^(3).The detector achieves a spatial resolution below 500μm and a sensitivity of 100 *** detector performance is tested at a proton therapy cyclotron and an Lpa proton *** experiments’primary focus is the characterization of the scintillator’s ionization quenching behaviour.

关键词： beam monitoring detectors laser-driven proton beams scintillator-based diagnostics ultra-high dose rate

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Identific tion of quantitative trait loci and associated candidate genes for pregnancy success in Angus–Brahman crossbred heifers

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Journal of Animal Science and Biotechnology 2024年第1期15卷 162-170页

作者： Quinn A.Hoorn gabriel A.Zayas eduardo e.Rodriguez Laura M.Jensen Raluca g.Mateescu Peter J.Hansen department of Animal Sciences Donald Henry Barron Reproductive and Perinatal Biology Research Programand the Genetics InstituteUniversity of FloridaGainesvilleFLUSA School of Applied Systems Biology La Trobe UniversityBundooraVIC 3083Australia

Background In beef cattle, more than 50% of the energy input to produce a unit of beef is consumed by the female that produced the calf. development of genomic tools to identify females with high genetic merit for reproductive function could increase the profitability and sustainability of beef *** genome-wide association studies(gWAS) were performed using a single-step genomic best linear unbiased prediction approach on pregnancy outcome traits from a population of Angus–Brahman crossbred heifers. Furthermore, a validation gWAS was performed using data from another farm. Heifers were genotyped with the Bovine ggP F250 array that contains 221,077 SNPs. In the discovery population, heifers were bred in winter breeding seasons involving a single round of timed artificial insemination(AI) followed by natural mating for 3 months. Two phenotypes were analyzed: pregnancy outcome to first-service AI(paI;n = 1,481) and pregnancy status at the end of the breeding season(PeBS;n = 1,725). The heritability was estimated as 0.149 and 0.122 for paI and PeBS, respectively. In the paI model, one quantitative trait locus(QTL), located between 52.3 and 52.5 Mb on BTA7, explained about 3% of the genetic variation, in a region containing a cluster of γ-protocadherin genes and SLC25A2. Other QTLs explaining between 0.5% and 1% of the genetic variation were found on BTA12 and 25. In the PeBS model, a large QTL on BTA7 was synonymous with the QTL for paI, with minor QTLs located on BTA5, 9, 10, 11, 19, and 20. The validation population for pregnancy status at the end of the breeding season were Angus–Brahman crossbred heifers bred by natural mating. In concordance with the discovery population, the large QTL on BTA7 and QTLs on BTA10 and 12 were *** In summary, QTLs and candidate SNPs identified were associated with pregnancy outcomes in beef heifers, including a large QTL associated with a group of protocadherin genes. Confirmation of these associations

关键词： Beef cattle Fertility gWAS QTL

excellent photoluminescence and electrochemical properties of Sm^(3+) doped Ca_(2)MgSi_(2)O_(7) nanophosphor:display and electrochemical sensor applications

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Journal of Rare earths 2024年第6期42卷 1046-1055,I0002页

作者： R.B.Basavaraj K.Sureshkumar d.P.Aarti M.B.Madhusudana Reddy g.Nagaraju T.Ramakrishnappa g.R.Navyashree K.R.Venkatesha Babu K.S.Hemalatha department of Physics BMS Institute of Technology and ManagementBangalore560064India department of Chemistry BMS Institute of Technology and ManagementBangalore560064India department of Chemistry School of Applied SciencesREVA UniversityBangalore560064India energy Materials ResearchLaboratory Department of ChemistrySiddaganga Institute of TechnologyTumakuru57203KarnatakaIndia School of Physical Sciences REVA UniversityBangalore560057Indi department of Physics Govt.Science CollegeBengaluru560001India department of Physics Maharani Science College for WomenMaharani Cluster UniversityBengaluru560001India

A series of orange-red light emitting Ca_(2)MgSi_(2)O_(7):Sm^(3+)nanopowders were fabricated via low-cost ecofriendly green combustion technique using Aloe vera gel as *** phase purity of the samples were confirmed by the powder X-ray diffraction(PXRd)*** single-phase tetragonal structure is observed from the PXRd results with no additional impurity *** band gap energy of the fabricated powders was estimated by diffuse reflectance spectra(dRS)and is found to be in the range of 4.01-5.98 eV.A high resolution scanning electron microscope(SeM)was used to study the morphological behaviour of the ***-like structures are observed from the SeM *** particle size was evaluated by transmission electron microscopy(TeM)and is found to be~50 *** interplanar distance is found to be 0.53 *** properties were systematically studied in *** phosphors are successfully excited at 403 nm NUV light,producing reddish-orange characteristic *** emission peaks are centered at 558(^(4)g_(5/2)→^(6)H_(5/2)),607(^(4)g_(5/2)→^(6)H_(7/2))and 645 nm(^(4)g_(5/2)→^(6)H_(9/2)),*** the observed peaks the red emanation(^(4)g_(5/2)→^(6)H_(7/2))is stronger than the orange emission(^(4)g_(5/2)→^(6)H_(5/2))in the current *** photoluminescent concentration quenching is noticed above 5 mol%Sm^(3+)ion doping *** dipole-dipole interaction resulting in cross relaxation is found to be the principal cause of concentration quenching *** color features such as Commission Internationale de I’eclairage(CIe)and correlated color temperature(CCT)were studied in *** optimized chromaticity coordinates were estimated to be(0.6363,0.3632),which fall in the reddish-orange *** average CCT value obtained is 3362 *** average color purity is found to be~82%.Sm^(3+)incorporated Ca_(2)MgSi_(2)O_(7) samples are possible contender for single white light generation commercial candidates owing to

关键词： green combustion Photoluminescence Orange-red emission Color purity Sensors Rare earths

Changes in structural plasticity of hippocampal neurons in an animal model of multiple sclerosis

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Zoological Research 2024年第2期45卷 398-414页

作者： Poornima d.e.Weerasinghe-Mudiyanselage Sohi Kang Joong-Sun Kim Sung-Ho Kim Hongbing Wang Taekyun Shin Changjong Moon department of Veterinary Anatomy and Animal Behavior College of Veterinary Medicine and BK21 FOUR ProgramChonnam National UniversityGwangju 61186Republic of Korea department of Anatomy and Convergence Medical Science Institute of Health SciencesCollege of MedicineGyeongsang National UniversityJinju 52727Republic of Korea department of Physiology and Neuroscience Program Michigan State UniversityEast LansingMI 48824USA department of Veterinary Anatomy College of Veterinary Medicine and Veterinary Medical Research InstituteJeju National UniversityJeju 63243Republic of Korea

Structural plasticity is critical for the functional diversity of neurons in the *** autoimmune encephalomyelitis(eAe)is the most commonly used model for multiple sclerosis(MS),successfully mimicking its key pathological features(inflammation,demyelination,axonal loss,and gliosis)and clinical symptoms(motor and non-motordysfunctions).Recentstudieshave demonstrated the importance of synaptic plasticity in eAe *** the present study,we investigated the features of behavioral alteration and hippocampal structural plasticity in eAe-affected mice in the early phase(11 days post-immunization,dPI)and chronic phase(28dPI).eAe-affected mice exhibited hippocampus-related behavioral dysfunction in the open field test during both early and chronic *** complexity was largely affected in the cornu ammonis 1(CA1)and CA3 apical and dentate gyrus(dg)subregions of the hippocampus during the chronic phase,while this effect was only noted in the CA1 apical subregion in the early ***,dendritic spine density was reduced in the hippocampal CA1 and CA3 apical/basal and dg subregions in the early phase of eAe,but only reduced in the dg subregion during the chronic ***,mRNA levels of proinflammatory cytokines(Il1β,Tnfα,and Ifnγ)and glial cell markers(gfap and Cd68)were significantly increased,whereas the expression of activity-regulated cytoskeletonassociated protein(ARC)was reduced during the chronic ***,exposure to the aforementioned cytokines in primary cultures of hippocampal neurons reduced dendritic complexity and ARC *** cultures of hippocampal neurons also showed significantly reduced extracellular signal-regulated kinase(eRK)phosphorylation upon treatment with proinflammatory ***,these results suggest that autoimmune neuroinflammation alters structural plasticity in the hippocampus,possibly through the eRK-ARC pathway,indicating that this alteration may be associated with hi

关键词： Activity-regulated cytoskeleton-associated protein Anxiety-like behavior experimental autoimmune encephalomyelitis Hippocampal dysfunction Neuroinflammation

dysregulated bidirectional epithelial-mesenchymal crosstalk:A core determinant of lung fibrosis progression

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Chinese Medical Journal Pulmonary and Critical Care Medicine 2024年第1期2卷 27-33页

作者： Liudi Yao Zijian Xu donna e.davies Mark g.Jones Yihua Wang Biological Sciences Faculty of Environmental and Life SciencesUniversity of SouthamptonSouthampton SO171BJUK Clinical and experimental Sciences Faculty of MedicineUniversity of SouthamptonSouthampton SO166YDUK Institute for Life Sciences University of SouthamptonSouthampton SO171BJUK NIHR Southampton Biomedical Research Centre University Hospital SouthamptonSouthampton SO166YDUK

Progressive lung fibrosis is characterized by dysregulated extracellular matrix(eCM)***-ing of disease pathogenesis remains limited and has prevented the development of effective *** an abnormal wound-healing response is strongly implicated in lung fibrosis initiation,factors that determine why fi-brosis progresses rather than regular tissue repair occur are not fully *** human lung fibrosis,there is evidence of altered epithelial and mesenchymal populations as well as cells undergoing epithelial-mesenchymal transition(eMT),a dynamic and reversible biological process by which epithelial cells lose their cell polarity and down-regulate cadherin-mediated cell-cell adhesion to gain migratory *** review will focus on the role of eMT and dysregulated epithelial-mesenchymal crosstalk in progressive lung fibrosis.

关键词： Lung fibrosis epithelial-mesenchymal transition(eMT) Crosstalk

development of an active-site titrant for SARS-CoV-2 main protease as an indispensable tool for evaluating enzyme kinetics

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Acta Pharmaceutica Sinica B 2024年第5期14卷 2349-2357页

作者： Rabea Voget Julian Breidenbach Tobias Claff Alexandra Hingst Katharina Sylvester Christian Steinebach Lan Phuong Vu Renato H.Weiße Ulrike Bartz Norbert Sträter Christa e.Müller Michael gütschow Pharmaceutical Institute Pharmaceutical&Medicinal ChemistryUniversity of BonnBonn 53121Germany Institute of Bioanalytical Chemistry Center for Biotechnology and BiomedicineLeipzig UniversityLeipzig 04103Germany department of Natural Sciences University of Applied Sciences Bonn-Rhein-SiegRheinbach 53359Germany

A titrant for the SARS-CoV-2 main protease(M^(pro))was developed that enables,for the first time,the exact determination of the concentration of the enzymatically active M^(pro) by active-site *** covalent binding mode of the tetrapeptidic titrant was elucidated by the determination of the crystal structure of the enzyme–titrant *** fluorogenic substrates of M^(pro),including a prototypical,internally quenched dabcyl-edANS peptide,were compared in terms of solubility under typical assay *** exploiting the new titrant,key kinetic parameters for the M^(pro)-catalyzed cleavage of these substrates were determined.

关键词： COVId-19 SARS-CoV-2 Main protease Peptide nitriles Fluorogenic substrates Active-site titration X-ray crystallography Inner filter effect