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Additively manufactured Ti–Ta–Cu alloys for the next-generation load-bearing implants

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International Journal of Extreme Manufacturing 2024年第1期6卷 353-374页

作者： Amit Bandyopadhyay Indranath Mitra Sushant Ciliveri Jose D avila William Dernell Stuart B Goodman Susmita Bose W.M.Keck Biomedical Materials research laboratory School of Mechanical and Materials EngineeringWashington State UniversityPullmanWA 99164United States of America Veterinary Clinical Sciences College of Veterinary MedicineWashington State UniversityPullmanWA 99164United States of America Department of Orthopedic Surgery Stanford University Medical CenterRedwood CityCA 94063United States of America

Bacterial colonization of orthopedic implants is one of the leading causes of failure and clinical complexities for load-bearing metallic implants. Topical or systemic administration of antibiotics may not offer the most efficient defense against colonization, especially in the case of secondary infection, leading to surgical removal of implants and in some cases even limbs. In this study, laser powder bed fusion was implemented to fabricate Ti3Al2V alloy by a 1:1 weight mixture of CpTi and Ti6Al4V powders. Ti-Tantalum(Ta)–Copper(Cu) alloys were further analyzed by the addition of Ta and Cu into the Ti3Al2V custom alloy. The biological,mechanical, and tribo-biocorrosion properties of Ti3Al2V alloy were evaluated. A 10 wt.% Ta(10Ta) and 3 wt.% Cu(3Cu) were added to the Ti3Al2V alloy to enhance biocompatibility and impart inherent bacterial resistance. Additively manufactured implants were investigated for resistance against Pseudomonas aeruginosa and Staphylococcus aureus strains of bacteria for up to 48 h. A 3 wt.% Cu addition to Ti3Al2V displayed improved antibacterial efficacy, i.e.78%–86% with respect to CpTi. Mechanical properties for Ti3Al2V–10Ta–3Cu alloy were evaluated, demonstrating excellent fatigue resistance, exceptional shear strength, and improved tribological and tribo-biocorrosion characteristics when compared to Ti6Al4V. In vivo studies using a rat distal femur model revealed improved early-stage osseointegration for alloys with10 wt.% Ta addition compared to CpTi and Ti6Al4V. The 3 wt.% Cu-added compositions displayed biocompatibility and no adverse infammatory response in vivo. Our results establish the Ti3Al2V–10Ta–3Cu alloy’s synergistic effect on improving both in vivo biocompatibility and microbial resistance for the next generation of load-bearing metallic implants.

关键词： Ti6Al4V load-bearing implants additive manufacturing 3D printing antibacterial performance

观察冠状动脉疾病病人心肌灌注:320-MDCT与82rb PET的比较

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国际医学放射学杂志 2018年第4期 500-500页

作者： r.N.Jr Dantas A.N.Jr Assuncao I.A.Marques M.G.fahel C.H.Nomura l.f.r.avila 吴迪 Computed Tomography Department Heart InstituteIn-CorUniversity of Sao Paulo Medical School

目的尽管CT多期相MPI在无创性心肌灌注成像（MPI）评估方面取得了进展,但其方案尚未与高度精确的82rb PET MPI进行比较。故本研究旨在评估82rb PET和320层CT（320-CT）MPI在疑似CAD病人中使用多期相方案的一致性。方法前瞻性纳入44例参... 详细信息

目的尽管CT多期相MPI在无创性心肌灌注成像（MPI）评估方面取得了进展,但其方案尚未与高度精确的82rb PET MPI进行比较。故本研究旨在评估82rb PET和320层CT（320-CT）MPI在疑似CAD病人中使用多期相方案的一致性。方法前瞻性纳入44例参加MPI评估并接受双嘧达莫应激82rb PET和多期相320-CT MPI（压力期间连续5次容积采集）的病人。统计分析使用r软件进行。结果总和压力评分≥4（κ=0.77,95%CI:0.55～0.98,Prb PET MPI对于评估中度危险性的可疑CAD病人,两者间存在一致性,多期相320-CT MPI方案是可行的,可诊断并且具有相对较低的辐射照射量。

关键词： PET MPI CAD rb PET

Spalling characteristics of high-temperature treated granitic rock at different strain rates

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Journal of rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1280-1288页

作者： l.f.fan Q.H.Yang X.l.Du The Key laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing100124China

The dynamic spalling characteristics of rock are important for stability analysis in rock *** paper presented an experimental investigation on the dynamic spalling characteristics of granite with different temperatures and strain rates.A series of dynamic spalling tests with different impact velocities were conducted on thermally treated granite at different *** dynamic spalling strengths of granite with different temperatures and strain rates were determined.A model was proposed to correlate the dynamic spalling strength of granite,high temperature and strain *** results show that the spalling strength of granite decreases with increasing ***,the spalling strength of granite with a higher strain rate is larger than that with a lower strain *** proposed model can describe the relationship among dynamic spalling strength of granite,high temperature and strain rate.

关键词： Dynamic spalling characteristics High temperature Strain rate Dynamic loading Granite

langmuir-Schaefer film Investigation and Density functional Theory Band Gap Calculations of Calix[n]arene-Para-Aminobenzoic Acid for Drug Nanosensor Application

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Journal of Wuhan University of Technology(Materials Science) 2024年第5期39卷 1311-1318页

作者： WONG Yeong Yi f l Supian A radzwan M Musa N f N Abd Karim Department of Physics Sultan Idris Education UniversityTanjong Malim 35900Malaysia Department of Chemistry Sultan Idris Education UniversityTanjong Malim 35900Malaysia

Calix[n]arenes was utilized to detect PABA,the primary sunscreen *** study investigates the interaction of calix[4]arene(C4),calix[6]arene(C6),and PABA using the langmuir method and first-principle density functional theory(DfT).Using the langmuir-Schaefer(lS)technique,an ultrathin film composed of calix[n]arenes and their complexes with PABA was deposited on various *** on the langmuir study,the PABA molecule was bonded to the lower rims of both C4 and C6 with the host-guest ratio of 1:*** of the lS films formed were then characterized by ultravioletvisible spectroscopy(UV-Vis),fourier-transform infrared spectroscopy(fTIr)and carbon,hydrogen,nitrogen,sulfur elemental analyzer(CHNS).The band gap reduction obtained in the DfT study denotes the charge transfer interaction with promising reactivity between the calix[n]arenes and *** sensing of PABA by C4 and C6 is successful based on the formation of bonding between them due to the hosts’effective trapping *** outcomes of this study could be applied to drug delivery systems for future pharmaceutical and medical applications.

关键词： calix[n]arenes band gap density functional theory langmuir-Schaefer PABA sensor

Two-Stream Approximation to the radiative Transfer Equation:A New Improvement and Comparative Accuracy with Existing Methods

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Advances in Atmospheric Sciences 2024年第2期41卷 278-292页

作者： f.Momo TEMGOUA l.Akana NGUIMDO DNJOMO Environmental Energy Technologies laboratory(EETl) Faculty of SciencesUniversity of YaoundéPO Box 812 YaoundéCameroon Department of Electrical and Electronic Engineering Faculty of Engineering and TechnologyUniversity of BueaPO Box 63 BueaCameroon

Mathematical modeling of the interaction between solar radiation and the Earth's atmosphere is formalized by the radiative transfer equation(rTE), whose resolution calls for two-stream approximations among other methods. This paper proposes a new two-stream approximation of the rTE with the development of the phase function and the intensity into a third-order series of legendre polynomials. This new approach, which adds one more term in the expression of the intensity and the phase function, allows in the conditions of a plane parallel atmosphere a new mathematical formulation of γparameters. It is then compared to the Eddington, Hemispheric Constant, Quadrature, Combined Delta function and Modified Eddington, and second-order approximation methods with reference to the Discrete Ordinate(Disort) method(δ –128 streams), considered as the most precise. This work also determines the conversion function of the proposed New Method using the fundamental definition of two-stream approximation(f-TSA) developed in a previous work. Notably,New Method has generally better precision compared to the second-order approximation and Hemispheric Constant methods. Compared to the Quadrature and Eddington methods, New Method shows very good precision for wide domains of the zenith angle μ 0, but tends to deviate from the Disort method with the zenith angle, especially for high values of optical thickness. In spite of this divergence in reflectance for high values of optical thickness, very strong correlation with the Disort method(r ≈ 1) was obtained for most cases of optical thickness in this study. An analysis of the legendre polynomial series for simple functions shows that the high precision is due to the fact that the approximated functions ameliorate the accuracy when the order of approximation increases, although it has been proven that there is a limit order depending on the function from which the precision is lost. This observation indicates that increasing the order of app

关键词： radiative Transfer Equation two-stream method legendre polynomial optical thickness moments of specific intensity conversion function transmittance reflectance

resource management at the network edge for federated learning

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Digital Communications and Networks 2024年第3期10卷 765-782页

作者： Silvana Trindade luiz f.Bittencourt Nelson l.S.da fonseca Institute of Computing State University of CampinasCampinasBrazil

federated learning has been explored as a promising solution for training machine learning models at the network edge,without sharing private user *** limited resources at the edge,new solutions must be developed to leverage the software and hardware resources as the existing solutions did not focus on resource management for network edge,specially for federated *** this paper,we describe the recent work on resource manage-ment at the edge and explore the challenges and future directions to allow the execution of federated learning at the *** such as the discovery of resources,deployment,load balancing,migration,and energy effi-ciency are discussed in the paper.

关键词： resource management Edge computing federated learning Machine learning

Effect of cylinder wall parameters on the final packing density of mono-disperse spheres subject to three-dimensional vibrations Author links open overlay panel

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Particuology 2024年第8期91卷 211-225页

作者： Jack r.Grogan Andrei l.Nicuşan Christopher r.K.Windows-Yule School of Chemical Engineering The University of BirminghamEdgbastonBirminghamB152TTUK

Achieving densely packed particles is desirable within the industries of ceramics,pharmaceuticals,defence and additive *** this work,we use the discrete element method(DEM)to determine the effect of wall parameters on the final packing density of mono-disperse spheres subject to 4 varying three-dimensional vibration and fill *** focus specifically on the impact of the container wall parameters on the particles'final packing *** on from the validation of the DEM simulation the particle-wall coefficient of restitution,the particle-wall coefficient of rolling friction and the particle-wall coefficient of sliding friction were varied individually and the effect on the final packing density *** relatively low particle-particle friction glass beads,the effect of these wall properties had no discernible effect on the final packing density *** on from these findings the particle-wall properties were varied at the extreme values of particle-particle coefficient of rolling friction and particle-particle coefficient of sliding *** a particle-particle coefficient of sliding friction=1,increases in particle-wall coefficient of restitution resulted in a minor increase in the final packing density of particles though this was not statistically *** a particle-particle coefficient of sliding friction=1,increases in particle-wall coefficient of rolling friction resulted in a minor decrease in the final packing density of the particles though again not to a degree where the trend can,with complete certainty,be distinguished from the random error across the ***,when the particle-particle coefficient of sliding friction=1,increases in particle-wall coefficient of sliding friction resulted in a significant decrease in the final packing density of *** decrease was attributed to the propagation of force chains throughout the *** significant decrease in final packing density with

关键词： Vibropacking Packing Densification Vibration Discrete element method friction Wall friction restitution

Alzheimer’s visual variant: a report of a diagnosis easily missed on ophthalmic examination

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International Journal of Ophthalmology(English edition) 2024年第8期17卷 1571-1575页

作者： Jorge Cárdenas-Belaunzarán lorena Wheelock-Gutierrez Karen A.Cerrillo-avila Department of Neuro-Ophthalmology Association to Prevent Blindness in MexicoI.A.P.Mexico City 04030Mexico Independent researcher Mexico City 04040Mexico

Dear Editor,We present a case of posterior cortical atrophy(PCA),which is a syndromic entity caused by different neurodegenerative diseases,mainly Alzheimer’s disease,but it has been described in several other *** frequency is reported to be as high as 5%of all cases;however,it remains widely under-recognized among ophthalmologists and optometrists due to scarce reports in visual health-related journals[1].

关键词： diagnosis Alzheimer diseases

Inflow and outflow permeability tests in a very soft clay under low stresses

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Journal of rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3270-3283页

作者： J.W.S.Vargas f.A.B.Danziger f.r.lopes T.lunne federal University of rio de Janeiro Rio de JaneiroBrazil Norwegian Geotechnical Institute OsloNorway

In situ inflow and outflow permeability tests with the BAT probe at SarapuíII soft clay test site are presented.A description of the BAT permeability test is provided,discussing its advantages and shortcomings,especially in the case of very soft clays under low *** pressures were monitored during probe installation and were found to be slightly lower than piezocone u2 pore pressures,consistent with the position of the *** role of filter tip saturation was investigated after the usual saturation procedure provided an unsatisfactory pore pressure response during probe *** show that the vacuum saturation procedure provides adequate response during installation and increases the reliability of the coefficient of permeability determination in early *** inflow and outflow tests yielded similar results,indicating that careful execution of the test can lead to good test repeatability regardless of the loading *** sequences of alternated inflow and outflow tests have yielded similar results,indicating that soil reconsolidation and filter clogging were negligible in the tests *** are presented concerning the relationship between index parameters and the in situ coefficient of permeability for SarapuíII clay,which plot outside the range of existing databases.

关键词： Permeability test Soft clay BAT probe Inflow and outflow tests