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The influence of resistance exercise training prescription variables on skeletal muscle mass,strength,and physical function in healthy adults:An umbrella review

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Journal of Sport and Health Science 2024年第1期13卷 47-60页

作者： Jonathan C.Mcleod Brad S.Currier Caroline V.Lowisz Stuart M.Phillips Department of Kinesiology Faculty of ScienceMcMaster UniversityHamilton L8S4L8Canada

Purpose:The aim of this umbrella review was to determine the impact of resistance training(RT)and individual RT prescription variables on muscle mass,strength,and physical function in healthy adults.Methods:Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines,we systematically searched and screened eligible systematic reviews reporting the effects of differing RT prescription variables on muscle mass(or its proxies),strength,and/or physical function in healthy adults aged>18 years.Results:We identified 44 systematic reviews that met our inclusion criteria.The methodological quality of these reviews was assessed using A Measurement Tool to Assess Systematic Reviews;standardized effectiveness statements were generated.We found that RT was consistently a potent stimulus for increasing skeletal muscle mass(4/4 reviews provide some or sufficient evidence),strength(4/6 reviews provided some or sufficient evidence),and physical function(1/1 review provided some evidence).RT load(6/8 reviews provided some or sufficient evidence),weekly frequency(2/4 reviews provided some or sufficient evidence),volume(3/7 reviews provided some or sufficient evidence),and exercise order(1/1 review provided some evidence)impacted RT-induced increases in muscular strength.We discovered that 2/3 reviews provided some or sufficient evidence that RT volume and contraction velocity influenced skeletal muscle mass,while 4/7 reviews provided insufficient evidence in favor of RT load impacting skeletal muscle mass.There was insufficient evidence to conclude that time of day,periodization,inter-set rest,set configuration,set end point,contraction velocity/time under tension,or exercise order(only pertaining to hypertrophy)influenced skeletal muscle adaptations.A paucity of data limited insights into the impact of RT prescription variables on physical function.Conclusion:Overall,RT increased muscle mass,strength,and physical function compared to no exercise.RT intensity(load)and weekly frequency impacted RT-

关键词： Hypertrophy Resistance training Resistance training prescription variables strength Umbrella review

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Negative enthalpy alloys and local chemical ordering:a concept and route leading to synergy of strength and ductility

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National Science Review 2024年第4期11卷 172-184页

作者： Zibing An Tao Yang Caijuan Shi Shengcheng Mao Lihua Wang Ang Li Wei Li Xianmeng Xue Ming Sun Yifan Bai Yapeng He Fuzeng Ren Zhouguang Lu Ming Yan Yang Ren Chain-Tsuan Liu Ze Zhang Xiaodong Han Beijing Key Lab of Microstructure and Property of Advanced Materials College of Materials Science &Engineering Beijing University of Technology Department of Materials Science and Engineering City University of Hong Kong Key Laboratory of Partial Acceleration Physics& Technology Institute of High Energy PhysicsChinese Academy of Sciences Department of Materials Science &Engineering Southern University of Science and Technology Department of Physics City University of Hong Kong State Key Laboratory of Silicon Materials Department of Materials Science and Engineering Zhejiang University

Solid solutions are ubiquitous in metals and alloys. Local chemical ordering(LCO) is a fundamental sub-nano/nanoscale process that occurs in many solid solutions and can be used as a microstructure to optimize strength and ductility. However, the formation of LCO has not been fully elucidated, let alone how to provide efficient routes for designing LCO to achieve synergistic effects on both superb strength and ductility. Herein, we propose the formation and control of LCO in negative enthalpy alloys. With engineering negative enthalpy in solid solutions, genetic LCO components are formed in negative enthalpy refractory high-entropy alloys(RHEAs). In contrast to conventional ‘trial-and-error' approaches, the control of LCO by using engineering negative enthalpy in RHEAs is instructive and results in superior strength(1160 MPa) and uniform ductility(24.5%) under tension at ambient temperature, which are among the best reported so far. LCO can promote dislocation cross-slip, enhancing the interaction between dislocations and their accumulation at large tensile strains; sustainable strain hardening can thereby be attained to ensure high ductility of the alloy. This work paves the way for new research fields on negative enthalpy solid solutions and alloys for the synergy of strength and ductility as well as new functions.

关键词： negative enthalpy alloys local chemical ordering strength ductility dislocation

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Estradiol increases cortical and trabecular bone accrual and bone strength in an adolescent male-to-female mouse model of gender-affirming hormone therapy

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Bone Research 2024年第1期12卷 95-106页

作者： Tian Nie Varun S.Venkatesh Suzanne Golub Kathryn S.Stok Haniyeh Hemmatian Reena Desai David J.Handelsman Jeffrey D.Zajac Mathis Grossmann Rachel A.Davey Department of Medicine Austin HealthUniversity of MelbourneHeidelbergVIC 3084Australia Department of Biomedical Engineering University of MelbourneParkvilleVIC 3010Australia ANZAC Research Institute University of Sydney and AndrologyConcord Repatriation General HospitalConcordNSW 2137Australia

The effects of gender-affirming hormone therapy on the skeletal integrity and fracture risk in transitioning adolescent trans girls are unknown.To address this knowledge gap,we developed a mouse model to simulate male-to-female transition in human adolescents in whom puberty is first arrested by using gonadotrophin-releasing hormone analogs with subsequent estradiol treatment.Puberty was suppressed by orchidectomy in male mice at 5 weeks of age.At 3 weeks post-surgery,male-to-female mice were treated with a high dose of estradiol(~0.85 mg)by intraperitoneal silastic implantation for 12 weeks.Controls included intact and orchidectomized males at 3 weeks post-surgery,vehicle-treated intact males,intact females and orchidectomized males at 12 weeks post-treatment.Compared to male controls,orchidectomized males exhibited decreased peak bone mass accrual and a decreased maximal force the bone could withstand prior to fracture.Estradiol treatment in orchidectomized male-to-female mice compared to mice in all control groups was associated with an increased cortical thickness in the mid-diaphysis,while the periosteal circumference increased to a level that was intermediate between intact male and female controls,resulting in increased maximal force and stiffness.In trabecular bone,estradiol treatment increased newly formed trabeculae arising from the growth plate as well as mineralizing surface/bone surface and bone formation rate,consistent with the anabolic action of estradiol on osteoblast proliferation.These data support the concept that skeletal integrity can be preserved and that long-term fractures may be prevented in trans girls treated with GnRHa and a sufficiently high dose of GAHT.Further study is needed to identify an optimal dose of estradiol that protects the bone without adverse side effects.

关键词： treatment treatment strength

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Enhancing strength-Ductility Synergy of CoCrNi-Based Medium-Entropy Alloy Through Coherent L1_(2)Nanoprecipitates and Grain Boundary Precipitates

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Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 78-88页

作者： Leilei Li Kaikai Song Qingwei Gao Changshan Zhou Xiaoming Liu Yaocen Wang Xiaojun Bai Chongde Cao School of Physical Science and Technology Northwestern Polytechnical UniversityXi’an710016China Weihai Research Institute of Industrial Technology Shandong UniversityWeihai264209China Research and Development Institute of Northwestern Polytechnical University in ShenzhenShenzhen518057China

The L1_(2)-strengthened Co_(34)Cr_(32)Ni_(27)Al_(4)Ti_(3)medium-entropy alloy(MEA)with precipitations of grain boundaries has been developed through selective laser melting(SLM)followed by cold rolling and annealing,exhibiting excellent strength-ductility synergy.The as-printed alloy exhibits low yield strength(YS)of~384 MPa,ultimate tensile strength(UTS)of~453 MPa,and uniform elongation(UE)of 1.5%due to the existence of the SLM-induced defects.After cold rolling and annealing,the YS,UTS,and UE are significantly increased to~739 MPa,~1230 MPa,and~47%,respectively.This enhancement primarily originates from the refined grain structure induced by cold rolling and annealing.The presence of coherent sphericalγ'precipitates(L1_(2)phases)and Al/Ti-rich precipitates at the grain boundaries,coupled with increased lattice defects such as dislocations,stacking faults,and ultrafine deformation twins,further contribute to the property’s improvement.Our study highlights the potential of SLM in producing high-strength and ductile MEA with coherent L1_(2)nanoprecipitates,which can be further optimized through subsequent rolling and annealing processes.These findings offer valuable insights for the development of high-performance alloys for future engineering applications.

关键词： Medium-entropy alloy Selective laser melting Precipitation strength Ductility

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The mechanisms of enhanced thickness-dependent DC breakdown strength of EP/MWCNTs nanocomposites

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High Voltage 2024年第2期9卷 440-452页

作者： Zhen Li He Gao Longfei Zhang Shouming Wang Ji Liu Shengtao Li Key Laboratory of Engineering Dielectrics and Its Application Ministry of EducationHarbin University of Science and TechnologyHarbinChina State Key Laboratory of Electrical Insulation and Power Equipment Xi'an Jiaotong UniversityXi'anChina

Owing to advanced power electronic and electrical applications developing towards miniaturisation and integration,the thickness-dependent DC breakdown mechanism of epoxy/multiwall-carbon-nanotube nanocomposites is under investigation.The results indicate that the breakdown strength of nanocomposites containing 0.05 wt%multiwall-carbon-nanotubes rises by~18%,and the breakdown strength falls exponentially with increasing thickness.To clarify the microscopic mechanism,a simulation model of DC breakdown,including carriers transport and segmental dynamics,is developed,and the accordant simulation results with experimental results indicate that the thickness-dependent DC breakdown of epoxy/multiwall-carbon-nanotube nanocomposites is determined both by segment chain dynamics and charge transport.According to the breakdown model analysis,the effects of multiwall-carbon-nanotube on enhanced breakdown strength are caused by the increased amount of deep traps in the interfacial region,while the influence of thickness is attributed to the enlarged segment chain displacement and electric field distortion as the voltage raising time increases.

关键词： strength breakdown nanocomposites

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Granting strength to aerogel fibers through encapsulation

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Science China Materials 2024年第4期67卷 1365-1366页

作者： Wenhui Xu Department of Basic Chemistry School of PharmacyJiangxi University of Chinese MedicineNanchang 330004China

Aerogel fibers, distinguished by their lightweight nature, pronounced porosity, large surface area, and superior thermal insulation properties, have diversified applications in thermal management, energy devices, and environmental remediation[1]. However, compared with monolithic ones, these fibershaped aerogels exhibit limited mechanical strength and resilience due to their one-dimensional small size.

关键词： strength fibers thermal

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A simple atomization approach enables monolayer dispersion of nano graphenes in cementitious composites with excellent strength gains

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Nano Materials Science 2024年第2期6卷 211-222页

作者： Nanxi Dang Rijiao Yang Chengji Xu Yu Peng Qiang Zeng Weijian Zhao Zhidong Zhang College of Civil Engineering and Architecture Zhejiang University310058HangzhouChina Center for Balance Architecture Zhejiang UniversityHangzhou310028China The Architectural Design&Research Institute of Zhejiang University Co. LtdHangzhou310063China Institute for Building Materials ETH Zurich8093ZurichSwitzerland

Carbon nano additives(CNAs)are critical to achieving the unique properties of functionalized composites,however,controlling the dispersion of CNAs in material matrix is always a challenging task.In this study,a simple atomization approach was successfully developed to promote the dispersion efficiency of graphene nanoplatelets(GNPs)in cement composites.This atomization approach can be integrated with the direct,indirect and combined ultrasonic stirrings in a homemade automatic stirring-atomization device.Mechanical and microstructure tests were performed on hardened cement pastes blended with GNPs in different stirring and mixing approaches.Results show that the direct ultrasonic stirrings enabled more homogeneous dispersions of GNP particles with a smaller size for a longer duration.The atomized droplets with the mean size of~100μm largely mitigated GNPs’agglomerations.Monolayer GNPs were observed in the cement matrix with the strength gain by up to 54%,and the total porosity decrease by 21%in 0.3 wt%GNPs dosage.The greatly enhanced dispersion efficiency of GNPs in cement also raised the cement hydration.This work provides an effective and manpower saving technique toward dispersing CNAs in engineering materials with great industrialization prospects.

关键词： Nanomaterials Dispersion Atomization strength Microstructure

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Exploring a balance between strength and ductility of hexagonal BN nanoplatelet reinforced ZK61 magnesium composite

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Journal of Magnesium and Alloys 2024年第5期12卷 1899-1910页

作者： Kewei Zhang Xiaolong Lu Yufeng Sun Shaokang Guan Yao Chen School of Materials Science and Engineering Zhengzhou University Key Laboratory of Advanced Magnesium Alloys in Henan Province Zhengzhou University Key Laboratory of Advanced Materials Processing&Mold Ministry of Education School of Mechanical and Electrical Engineering Soochow University

The practical applications of magnesium（Mg） alloys are usually beset by their relatively low strength and limited ductility. Herein we attempt to fabricate hexagonal BN nanoplatelet（BNNP） reinforced ZK61 magnesium composites using a combination of spark plasma sintering and friction stir processing. The resulting composites exhibit microstructural characteristics of homogeneous dispersion of BNNP in Mg matrix with refined equiaxed grains and（0002） basal texture roughly surrounding the pin column surface. Transmission electron microscopy observation illustrates that trace amounts of Mg3N2and MgB2form at BNNP-Mg interface, in which Mg3N2locates at the basal plane of a BNNP and MgB2grows at its open edge. The spatial distribution of Mg3N2and MgB2facilitates interfacial wetting and stronger BNNP-Mg interface in such a way that interfacial products act as anchors bonding between them. In comparison with monolithic ZK61 alloy,the BNNP/ZK61 composites display simultaneous improvements in yield strength, hardness and ductility, achieving good strength-ductility balance. This research is expected to shed some light on BNNP potentials for designing and producing magnesium composites with high strength and good ductility.

关键词： BN nanoplatelet Magnesium composite strength Ductility Spark plasma sintering Friction stir processing

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Superplastic Tension Behavior of Dissimilar TC4/SP700 Laminate through Diffusion Bonding

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 353-363页

作者： Qianwen Zhang Tianle Li Yanbin Han Wei Zheng Xifeng Li Jianjun Wu School of Mechanical Engineering Northwestern Polytechnical UniversityXi’an710072China AVIC Xi’an Aircraft Industry Group Company Ltd Xi’an710089China Institute of Forming Technology and Equipment School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai200030China

Superplastic forming is a practical method to manufacture complex-shaped parts of titanium alloys with large deformation.Laminated parts of dissimilar titanium alloys fabricated by superplastic forming can achieve excellent performance by combining the advantages of components.This work displays the superplastic tension behavior and microstructural evolution of dissimilar TC4/SP700 laminate prepared by the diffusion bonding process.Two titanium alloys can achieve metallurgical bonding at parameters of 800℃/1 h/5 MPa.Except for dynamic recrystallization and grain growth behaviors upon superplastic tension,stress-induced phase transformation plays an important role inαtoβphase transformation apart from the elevated temperature.The superplastic deformation can be attributed to the grain boundary sliding accommodated multiplex motion of dislocations.In addition,the retained strengths of all dissimilar TC4/SP700 laminates after superplastic deformation with different strain rates and temperatures range from 807 to 890 MPa.

关键词： TC4/SP700 laminate Diffusion bonding Microstructure Superplastic tension strength

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Distinct Electrical and Mechanical Responses of a Cu-10Fe Composite Prepared by Hot-Pressed Sintering and Post Treatment

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 255-265页

作者： X.Y.Yue S.Y.Peng X.Zhang C.N.He Y.Z.Tian Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Materials Science and EngineeringNortheastern UniversityShenyang110819China School of Materials Science and Engineering and Tianjin Key Laboratory of Composite and Functional Materials Tianjin UniversityTianjin300350China Research Centre for Metallic Wires Northeastern UniversityShenyang110819China

A Cu-10wt%Fe composite was prepared through hot-pressed sintering,and the material was subsequently solution treated.The hot-pressed sintered and solution treated materials were rolled and aged.The precipitation behavior and performance changes were systematically studied by using scanning electron microscopy and transmission electron microscopy.In contrast to the hot-pressed sintered specimen,the solution treatment significantly affects the thermal stability and properties of the Cu-10wt%Fe composite.The Cu-10wt%Fe composite was prepared after solid solution,cold rolling and aging at 773 K for 1 h,and it obtained excellent tensile strength of 494 MPa,uniform elongation of 16.3%,electrical conductivity of 51.1%IACS and softening temperature of 838 K.Mechanisms for the distinct difference in thermal stability and properties between hot-pressed sintered and solution treated specimens were analyzed.These findings provide a theoretical basis for designing high-performance Cu-based in-situ composites by post treatment.

关键词： Cu-Fe composite Hot-pressed sintering Thermal stability strength Electrical conductivity

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