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Comparative analysis of.microstructure,mechanical,and corrosion properties of.biodegradable Mg-3Y alloy prepared by selective laser melting and spark plasma sintering

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j.urnal of.Magnesium and Alloys 2024年第4期12卷 1496-1510页

作者： P.Minárik M.Zemková S.Šašek j.Dittrich M.Knapek f.Lukáˇc D.Koutný j.j.roš R.Král f.culty of.Mathematics and Physics Charles UniversityKe Karlovu 5Praha 12116Czech Republic Research Centre University ofŽilinaUniverzitná8215/1Žilina 01026Slovakia Institute of.Plasma Physics of.the Czech Academy of.Sciences Za Slovankou 1782/318200 Praha 8Czech Republic Institute of.Machine and Industrial Design Brno University of TechnologyTechnická2896/2Brno 61669Czech Republic

This work explored possibilities of.biodegradable magnesium alloy Mg-3Y preparation by two modern powder metallurgy techniques–spark plasma sintering(SPS)and selective laser melting(SLM).The powder material was consolidated by both methods utilising optimised parameters,which led to very low porosity(∼0.3%)in the SLM material and unmeasurably low porosity in the SPS *** main aim of.the study was the thorough microstructure characterisation and interrelation between the microstructure and the f.nctional properties,such as mechanical strength,def.rmability,and corrosion *** materials showed comparable strength of.110 MPa in tension and compression and relatively good def.rmability of.9%and∼21%f.r the SLM and SPS materials,*** corrosion resistance of.the SPS material in 0.1 M NaCl solution was superior to the SLM one and comparable to the conventional extruded *** digital image correlation during loading and the cross-section analysis of.the corrosion layers revealed that the residual porosity and large strained grains have the dominant negative ef.ect on the f.nctional properties of.the SLM *** the other hand,one of.the primary outcomes of.this study is that the SPS consolidation method is very ef.ective in the preparation of.the W3 biodegradable alloy,resulting in material with convenient mechanical and degradation properties that might f.nd practical applications.

关键词： Magnesium Yttrium Powder metallurgy Microstructure Mechanical strength Corrosion resistance

Bulking Up the Bay-Position Substituents Enables Enhanced Selectivity of.C_(s)‑Symmetric Boron Subphthalocyanine−Subnaphthalocyanine Hybrids

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Precision Chemistry 2024年第4期2卷 161-181页

作者： Nina f.f.rac Alan j.Lough Timothy P.Bender Department of.Chemical Engineering and Applied Chemistry University of TorontoTorontoOntario M5S 3E5Canada Department of.Chemistry University of TorontoTorontoOntario M5S 3H6Canada Department of.Materials Science and Engineering University of TorontoTorontoOntario M5S 3E4Canada Department of.Mechanical and Industrial Engineering University of TorontoTorontoOntario M5S 3G8Canada

The precise synthesis of.subporphyrinoid hybrids withπ-expanded topologies and unique material properties plays a promising role in the design of.f.nctional ***,selective,and controllable routes to boron subphthalocyanine−subnaphthalocyanine hybrids,Bsub(Pc_(3‑p)-Nc_(p))s,are desirable f.r this purpose yet synthetically challenging due to random mixtures of.C_(s-),C_(3v-),and,in some cases,C_(1)-symmetric compounds that f.rm during traditional statistical mixed ***,we addressed this issue by developing a sterically driven mixed cyclotrimerization with enhanced selectivity f.r the targeted C_(s)-symmetric hybrid and complete suppression of.sterically crowded macrocyclic *** process,coupled with a rationally designed precursor bearing bulky phenyl substituents,enabled the synthesis and characterization of.bay-position phenylated Ph_(2)-(R_(p))_(8)Bsub(Pc_(2)-Nc_(1))hybrids with halogens(Rp=Cl or f.in their peripheral isoindole *** selectivity ranged between 59 and 72%with remarkable yields,signif.cantly higher than that of.conventional mixed *** f.ndings were augmented by theoretical calculations on precursor Lewis basicity as guiding principles into hybrid macrocycle ***,the incorporation of.unf.sed phenyl groups and halogen atoms into the hybrid f.amework resulted in f.ne-tuned optical,structural,electronic,and electrochemical *** straightf.rward approach achieved improved selectivity and controlled narrowing of.the product distribution,af.ording the ef.icient synthesis of.structurally sophisticated Bsub(Pc_(2)-Nc_(1))*** then expands the library of.3-dimensionalπ-extended macrocycles f.r use in a range of.applications,such as in optoelectronic devices with precisely tailored optical properties.

关键词： subphthalocyanine hybrids low-symmetry aromatic macrocycle selective cyclotrimerization sterically driven chemistry broad absorption material properties

Long-term Integration Ability of.the Submillimeter Wave Astronomy Satellite(SWAS)Spectral Line Receivers

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Research in Astronomy and Astrophysics 2024年第6期24卷 315-322页

作者： Bing-Ru Wang Di Li Paul f.Goldsmith j.ngwen Wu Chao-Wei Tsai Rudolf.Schieder Gary j.Melnick National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of.Chinese Academy of.Sciences Beijing 100049China Research Center f.r Astronomical Computing Zhejiang LaboratoryHangzhou 311100China j.t Propulsion Laboratory California Institute of TechnologyPasadenaCA 91109USA Institute f.r f.ontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China KOSMA I.Physik.InstitutUniversität zu KölnZülpicher Str.7750937 KölnGermany Center f.r Astrophysics|Harvard&Smithsonian 60 Garden StreetMS 66CambridgeMA 02138USA

The Submillimeter Wave Astronomy Satellite(SWAS)was the f.rst space telescope capable of.high spectral resolution observations of.terahertz spectral *** have investigated the integration ability of.its two receivers and spectrometer during f.ve and a half.years of.on-orbit *** CI,O_(2),H_(2)O,and^(13)CO spectra taken toward all observed Galactic sources were *** present results are based on spectra with a total integration time of.up to 2.72×10~4hr(■10~8s).The noise in the spectra is generally consistent with that expected f.om the radiometer equation,without any sign of.approaching a noise *** noise perf.rmance ref.ects the extremely stable perf.rmance of.the passively cooled f.ont end as well as other relevant components in the SWAS instrument throughout its mission lif.time.

关键词： telescopes space vehicles:instruments instrumentation:miscellaneous ISM:lines and bands

Telomeric DNA breaks in human induced pluripotent stem cells trigger ATR-mediated arrest and telomerase-independent telomere damage repair

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j.urnal of.Molecular Cell Biology 2024年第3期16卷 46-60页

作者： Katrina N.Estep j.hn W.Tobias Raf.el j.f.rnandez Brinley M.Beveridge f.Brad j.hnson Department of.Pathology and Laboratory Medicine University of PennsylvaniaPhiladelphiaPA 19104USA Quantiative Biosciences Merck&Co.Inc.West PointPA 19486USA Penn Genomic Analysis Core University of PennsylvaniaPhiladelphiaPA 19104USA

Although mechanisms of.telomere protection are well-def.ned in dif.erentiated cells,how stem cells sense and respond to telomere dysf.nction,in particular telomeric double-strand breaks(DSBs),is poorly ***,we report the DNA damage signaling,cell cycle,and transcriptome changes in human induced pluripotent stem cells(iPSCs)in response to telomere-internal *** engineer human iPSCs with an inducible TRf.-f.kI f.sion protein to acutely induce DSBs at *** this model,we demonstrate that TRf.-f.kI DSBs activate an ATR-dependent DNA damage response,which leads to p53-independent cell cycle arrest in *** CRISPR–Cas9 to cripple the catalytic domain of.telomerase reverse transcriptase,we show that telomerase is largely dispensable f.r survival and lengthening of.TRf.-f.kI-cleaved telomeres,which instead are ef.ectively repaired by robust homologous recombination(HR).In contrast to HR-based telomere maintenance in mouse embryonic stem cells,where HR causes ZSCAN4-dependent extension of.telomeres beyond their initial lengths,HR-based repair of.telomeric breaks is suf.icient to maintain iPSC telomeres at a normal length,which is compatible with sustained survival of.the cells over several days of.TRf.-f.kI *** f.ndings suggest a previously unappreciated role f.r HR in telomere maintenance in telomerase-positive iPSCs and reveal distinct iPSC-specif.c responses to targeted telomeric DNA damage.

关键词： telomeres telomerase alternative lengthening of.telomeres pluripotent stem cells DNA damage double-strand breaks

Phase composition,conductivity,and sensor properties of.cerium-doped indium oxide

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Nano Materials Science 2024年第2期6卷 193-200页

作者： M.I.Ikim G.N.Gerasimov V.f.Gromov O.j.Ilegbusi L.I.Trakhtenberg N.N.Semenov f.deral Research Center f.r Chemical Physics of.RAS MoscowRussia University of.Central f.orida OrlandoFLUSA Moscow Institute of.Physics and Technology(State University) DolgoprudnyMoscow RegionRussia Lomonosov Moscow State University MoscowRussia

The hydrothermal synthesis of.In_(2)O_(3)and CeO_(2)–In_(2)O_(3)is investigated as well as the properties of.sensor layers based on these *** the synthesis of.In_(2)O_(3),intermediate products In(OH)_(3)and InOOH are f.rmed,which are the precursors of.stable cubic(c-In_(2)O_(3))and metastable rhombohedral(rh-In_(2)O_(3))phases,respectively.A transition f.om c-In_(2)O_(3)to rh-In_(2)O_(3)is observed with the addition of.CeO_(2).The introduction of.cerium into rh-In_(2)O_(3)results in a decrease in the sensor response to hydrogen,while it increases in composites based on c-In_(2)O_(3).The data on the sensor activity of.the composites correlate with XPS results in which CeO_(2)causes a decrease in the concentrations of.chemisorbed oxygen and oxygen vacancies in rh-In_(2)O_(3).The reverse situation is observed in composites based on c-In_(2)O_(3).Compared to In_(2)O_(3)and CeO_(2)–In_(2)O_(3)obtained by other methods,the synthesized composites demonstrate maximum response to H_(2)at low temperatures by 70–100℃,and have short response time(0.2–0.5 s),short recovery time(6–7 s),and long-term stability.A model is proposed f.r the dependence of.sensitivity on the direction of.electron transf.r between In_(2)O_(3)and CeO_(2).

关键词： Cerium oxide Indium oxide Nanocomposite Hydrothermal method Cubic phase Rhombohedral phase Sensor response Conductivity Hydrogen Response/recovery time

Towards ef.icient strain engineering of.2D materials:A f.ur-points bending approach f.r compressive strain

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Nano Research 2024年第6期17卷 5317-5325页

作者： Hao Li f.lix Carrascoso Ana Borrás Gloria P.Moreno f.ancisco j.Aparicio Ángel Barranco Andrés Castellanos Gómez Campus de Cantoblanco Instituto de Ciencia de Materiales de MadridC.Sor Juana Inés de la Cruz328049 MadridSpain Nanotechnology on Surf.ces and Plasma Lab Instituto de Ciencia de Materiales de Sevilla(CSIC-Universidad de Sevilla).C/Americo Vespucio 49E-41092 SevilleSpain Departamento de f.sica Aplicada I Escuela Politécnica SuperiorUniversidad de Sevillac/Virgen deÁfrica 7E-41011 SevilleSpain

Strain engineering,as a powerf.l strategy to tune the optical and electrical properties of.two-dimensional(2D)materials by def.rming their crystal lattice,has attracted signif.cant interest in recent years.2D materials can sustain ultra-high strains,even up to 10%,due to the lack of.dangling bonds on their surf.ce,making them ideal brittle *** remarkable mechanical resilience,together with a strong strain-tunable band structure,endows 2D materials with a broad optical and electrical response upon ***,strain engineering based on 2D materials is restricted by their nanoscale and strain quantif.cation *** this study,we have modif.ed a homebuilt three-points bending apparatus to transf.rm it into a f.ur-points bending apparatus that allows f.r the application of.both compressive and tensile strains on 2D *** approach allows f.r the ef.icient and reproducible construction of.a strain system and minimizes the buckling ef.ect caused by the van der Waals interaction by adamantane encapsulation *** results demonstrate the f.asibility of.introducing compressive strain on 2D materials and the potential f.r tuning their optical and physical properties through this approach.

关键词： uniaxial compressive strain polymer encapsulation dif.erential ref.ectance spectroscopy exciton tunability

f.eding 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 f.rnando Sequeira Susana Lopes Adrian j.f.K.Craig Vanessa A.Mata Department of.Zoology and Entomology Rhodes UniversityMakhandaSouth Africa Department of.Wildlif. 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 Af.ica,oxpeckers of.er a unique model f.r studying symbiotic *** to the multitrophic level they occupy and the context dependent f.raging behavior they exhibit,the type of.symbiotic relationship can be *** addition to providing a cleaning service to the host by removing ticks,oxpeckers f.equently f.ed on blood,mucus,and saliva,inf.icting potential damage on the ***,we used DNA metabarcoding on f.ecal samples to analyze the taxonomic composition of.the trophic interactions of.the Yellow-billed Oxpecker(Buphagus af.icanus)and Red-billed Oxpecker(***)in northeastern *** contrast to conventional methods,DNA metabarcoding allows f.r a detailed identif.cation of.dietary resources encompassing both mammal hosts and consumed arthropods within the same *** this inf.rmation,we examined dif.erences in the diet composition between oxpecker species and localities,as well as the co-occurrence between host and arthropod *** f.ndings revealed that oxpeckers predominantly source their diet f.om mammals,ticks,and f.ies;however,ticks and f.ies rarely co-occur in the diet of.an *** observed variability among individuals in their f.eding 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 f.raging 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

Hydroxychloroquine in SARS-CoV-2 inf.ction:Understanding the misadventure

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j.urnal of.Acute Disease 2024年第2期13卷 45-52页

作者： David Banj. Otilia j.f.Banj. Department of.Pharmacology&Toxicology College of PharmacyJazan UniversitySaudi Arabia Department of.Clinical Pharmacy College of PharmacyJazan UniversitySaudi Arabia

The widespread outbreak of.SARS-CoV-2 was declared a public health emergency by the World Health Organization and various governments *** prompted the implementation of.stringent inf.ction control measures to curb the spread of.the *** this,the medical community f.ced the challenge of.treating the virus without specif.c therapies or a vaccine,leading to reliance on empirical treatment *** this context,hydroxychloroquine,an antimalarial and antirheumatic drug,gained attention as a potential treatment *** its theoretical benef.ts,such as inhibiting viral entry,reducing inf.ammation,and modulating immune responses,empirical studies yielded inconsistent *** indicated a potential f.r symptom relief.while others showed no signif.cant improvement in patient *** initial enthusiasm waned as the lack of.substantial evidence led to revoking its Emergency Use Authorization,and several clinical trials were prematurely *** review in question critically examines the f.ctors contributing to the inef.ectiveness of.hydroxychloroquine in treating SARS-CoV-2 inf.ction,highlighting the complexities of.drug repurposing during a rapidly evolving pandemic.

关键词： SARS-CoV-2 Hydroxychloroquine Pharmacogenomics TLR signaling Cardiotoxicity

Radiof.equency ablation versus microwave ablation f.r colorectal liver metastases:long-term results of.a retrospective cohort surgical experience

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Hepatobiliary Surgery and Nutrition 2024年第5期13卷 759-770,I0001页

作者： Ali Gunduz Sarioglu Chase j.Wehrle Ege Akgun Arturan Ibrahimli j.mes f.Bena Eren Berber Department of.Endocrine Surgery Cleveland ClinicClevelandOHUSA Department of.General Surgery Cleveland ClinicClevelandOHUSA Department of.Quantitative Health Sciences Cleveland ClinicClevelandOHUSA

Background:Ablation is an alternative treatment modality f.r selected patients with colorectal liver metastases(CRLMs).Although initially widely perf.rmed via radiof.equency ablation(Rf.),more recently,microwave ablation(MWA)is being pref.rred due to its perceived superiority in creating the ablation *** aim of.this study is to compare the long-term ef.icacy of.these two modalities perf.rmed ***:Patients undergoing surgical liver ablation f.om 2005-2023 at a tertiary center by a single surgeon f.r CRLM were included in a retrospective institutional review board-approved *** were compared using Wilcoxon,Chi-square,Kaplan-Meier,and Cox multivariate regression *** data are presented as median(interquartile range).Results:There were a total of.242 *** Rf. was done in 121 patients with 303 lesions and laparoscopic MWA in 121 patients with 300 *** was no dif.erence between the groups regarding operative time(161 vs.147 minutes,respectively,P=0.4),perioperative morbidity(3%vs.8%,respectively,P=0.2)or hospital stay(1 vs.1 day,P=0.05).Local recurrence(LR)per lesion with at least 1 year of.imaging f.llow-up was 29%in the Rf. and 13%in the MWA group(Pf.*** control these variables,direct matching was *** cohort included 189 ***-Meier analysis of.these cohorts showed increased LR-f.ee survival in the MWA group *** Rf. group(P=0.005).Conclusions:This large study conf.rms our initial observation that local tumor control rate is better af.er MWA ***.

关键词： Colorectal cancer liver metastasis liver ablation radiof.equency ablation(Rf.) microwave ablation(MWA) local recurrence(LR)