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

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

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Examining the“revisability”benefit of hip resurfacing arthroplasty

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World Journal of Orthopedics 2024年第6期15卷 554-559页

作者： jose George Adam J Taylor Thomas P Schmalzried Department of Orthopedics Harbor UCLA Medical CenterTorranceCA 90509United States

BACKGROUND Hip resurfacing arthroplasty(HRA)is an alternative to total hip arthroplasty(THA)that is typically reserved for young active patients because it preserves ***,the benefits of HRA only hold true if conversion THA after failed HRA provides acceptable *** To compare patient reported outcomes for conversion THA after HRA failure to primary *** A retrospective review of 36 patients(37 hips)that underwent conversion THA for failed HRA between October 2006 and May 2019 by a single surgeon was *** reported outcomes[modified Harris Hip Score(mHHS),University of california Los Angeles(UCLA)activity score]were obtained via an email-based responder-anonymous *** were compared to normative data of a primary THA cohort with similar *** analysis was performed comparing outcomes of conversion THA for adverse local tissue reaction(ALTR)vs all other causes for *** The study group had a lower mHHS than the control group(81.7±13.8 vs 90.2±11.6,Pcauses had similar mHHS(85.2±11.5 vs 90.2±11.6,P=0.11)and higher UCLA activity levels(8.5±1.8 vs 7.2±1.6,Pcan be achieved following HRA conversion to ***,inferior outcomes were demonstrated for ALTR-related HRA *** selection and perhaps further studies examining alternative HRA bearing surfaces should be considered.

关键词： Total hip arthroplasty Hip resurfacing arthroplasty Conversion total hip arthroplasty Adverse local tissue reaction Patient reported outcome measures

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Matrix metalloproteinases and their expression in mammary gland

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Cell Research 1998年第3期8卷 187-194页

作者： URIA jose A ZENA WERB(Department of Anatomy, University of california San Francisco, ca 94143-0452, USA) Department of Anatomy University of California San Francisco CA USA

The matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that play a key role in both normal and pathological processes involving tissue remodeling events. The expression of these proteolytic enzymes is highly regulated by a balance between extracellular matrix (ECM) deposition and its degradation, and is controlled by growth factors, cytokines, hormones, as well as interactions with the ECM macromolecules. Furthermore, the activity of the MMPs is regulated by their natural endogenous inhibitors, which are members of the tissue inhibitor of metalloproteinases (TIMP) family. In the normal mammary gland, MMPs are expressed during ductal development, lobulo-alveolar development in pregnancy and involution after lactation. Under pathological conditions, such as tumorigenesis, the dysregulated expression of MMPs play a role in tumor initiation, progression and malignant conversion as well as facilitating invasion and motastasis of malignant cells through degradation of the ECM and basement membranes. Matrix metalloproteinases and their expression in mammary gland

关键词： Matrix metalloproteinases ECM cancer progression mammary gland

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The Drought of Amazonia in 2023-2024

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American Journal of Climate Change 2024年第3期13卷 567-597页

作者： jose A. Marengo Ana P. Cunha Jhan-carlo Espinoza Rong Fu Jochen Schöngart jua. C. Jimenez Mabel C. Costa Joao M. Ribeiro Sly Wongchuig Siyu Zhao National Center for Monitoring and Early Warning of Natural Disasters/CEMADEN So Jos dos Campos Brazil UNESP/CEMADEN So Jos dos Campos Brazil Graduate School of International Studies Korea University Seoul South Korea Institut des Gosciences de lEnvironnement (IGE) Institut de Recherche pour le Dvelopement (IRD) Saint Martin dHeres France Instituto de Investigacin sobre la Enseanza de las Matemticas (IREM PUCP) Pontificia Universidad Catlica del Per Lima Peru Department of Atmospheric and Oceanic Sciences University of California Los Angeles Los Angeles CA USA Departament of Environmental Dynamics Instituto Nacional de Pesquisas da Amaznia (INPA) Manaus Brazil Global Change Unit (GCU) of the Image Processing Laboratory (IPL) Universitat de Valncia Estudi General (UVEG) Paterna Spain Laboratoire dEtudes en Gophysique et Ocanographie Spatiales (LEGOS) Universit de Toulouse CNES/CNRS/IRD/UT3 Toulouse France

The Amazon basin has experienced an extreme drought that started in the austral summer of 2022-23 and extends into 2024. This drought started earlier than other previous droughts. Although some rain fell during the austral summer, totals remained below average. Higher temperatures during austral winter and spring 2023, which affected most of Central South America, then aggravated drought conditions. This coincided with an intense El Niño and abnormally warm tropical North Atlantic Ocean temperatures since mid-2023. Decreased rainfall across the Amazon basin, negative anomalies in evapotranspiration (derived from latent heat) and soil moisture indicators, as well as increased temperatures during the dry-to-wet transition season, September-October-November (SON) 2023, combined to delay the onset of the wet season in the hydrological year 2023-24 by nearly two months and caused it to be uncharacteristically weak. SON 2023 registered a precipitation deficit of the order of 50 to 100 mm/month, and temperatures +3˚C higher than usual in Amazonia, leading to reduced evapotranspiration and soil moisture indicators. These processes, in turn, determined an exceptionally late onset and a lengthening of the dry season, affecting the 2023-2024 hydrological year. These changes were aggravated by a heat wave from June to December 2023. Drought-heat compound events and their consequences are the most critical natural threats to society. River levels reached record lows, or dried up completely, affecting Amazonian ecosystems. Increased risk of wildfires is another concern exacerbated by these conditions.

关键词： El Niño SST in the Tropical Atlantic Amazon Drought River Levels Heatwave Dry Season Length

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Extending dynamic models of mining subsidence

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中国有色金属学会会刊：英文版 2011年第S3期21卷 536-542页

作者： Andrew JAROSZ jose SAAVEDRA-ROSAS Western Australian School of Mines Curtin University

The movement and deformation processes of the overburden strata and ground surface, induced by underground mining, are affected by mining method, spatial relationships, geotechnical conditions of the rock strata and time. The authors reviewed and extended an existing classical prediction model of the dynamic subsidence, and proposed potential new research avenues offered by Cellular Automata (ca) models. The Knothe's influence function model and the significance of subcritical mining geometry were analyzed. The prediction results were verified against the subsidence field survey data to assess their quality and acceptability.

关键词： dynamic subsidence subsidence prediction cellular automata

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A neural network to predict reactor core behaviors

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Nuclear Science and Techniques 2014年第1期25卷 75-80页

作者： jua. jose Ortiz-Servin David A.Pelta jose Alejro castillo Instituto Nacional de Investigaciones Nucleares Carretera Mexico Toluca S/NLa Marquesa OcoyoacacEstado de Mexico ETS Ingenieria Informatica y Telecomunicaciones Universidad de GranadaC/Daniel Saucedo Aranda

The global fuel management problem in BWRs(Boiling Water Reactors) can be understood as a very complex optimization problem,where the variables represent design decisions and the quality assessment of each solution is done through a complex and computational expensive *** last aspect is the major impediment to perform an extensive exploration of the design space,mainly due to the time lost evaluating non promising *** this work,we show how we can train a Multi-Layer Perceptron(MLP) to predict the reactor behavior for a given *** trained MLP is able to evaluate the configurations immediately,thus allowing performing an exhaustive evaluation of the possible configurations derived from a stock of fuel lattices,fuel reload patterns and control rods *** our particular problem,the number of configurations is approximately 7.7×10^(10);the evaluation with the core simulator would need above 200 years,while only 100hours were required with our approach to discern between bad and good *** later were then evaluated by the simulator and we confirm the MLP *** good core configurations reached the energy requirements,satisfied the safety parameter constrains and they could reduce uranium enrichment costs.

关键词：神经网络预测行为质量评估堆芯沸水反应堆多层感知器 MLP 优化问题

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Heavy Metal Adsorption Properties of Marine Algae Durvilliea Potatorum,Ecklonia Radiata and Laminaria Japonica

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Chinese Journal of Chemical Engineering 1998年第1期6卷 72-76页

作者：虞启明 jose T.Matheickal Jozef Latten School of Environmental Engineering Griffith University

1 INTRODUCTIONBiosorption of heavy metals using biosorbents derived from suitable biomass is a new tech-nology for the removal and recovery of heavy metals from industrial waste *** ad-vantages of the biosorption technology include rapid reduction of dissolved heavy metal ionsconcentration to 10-6and 10-9levels,use of inexpensive and non-hazardous biosorbents,useof existing adsorption process equipment and therefore low operating costs,high uptake ca-pacity and specificity for selective heavy metal removals,and low interference from

关键词： biosorption heavy metal removal marine algae

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Expression of juvenile hormone acid O-methyltransferase and juvenile hormone synthesis in Blattella germanica

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Insect Science 2018年第5期25卷 787-796页

作者： Claudia V. Dominguez jose L. Maestro Institute of Evolutionary Biology CSIC-Universitat Pompeu Fabra Barcelona Spain

Juvenile hormone （JH）, a sesquiterpenoid synthetized by the insect corpora allata （ca）, plays critical roles in metamorphosis and reproduction. Penultimate or last step of JH synthesis is catalyzed by juvenile hormone acid O-methyltransferase （JHAMT）. Here we report the cloning and expression analysis of the JHAMT orthologue in the cockroach, Blattella germanica （L.）（BgJHAMT）. BgJHAMT is mainly expressed in ca, with only expression traces in ovary. Three different isoforms, differing in the 3＇-UTR sequence, were identified. Isoform A shows between 35 and 65 times higher expression than B and C in ca from penultimate nymphal instar and adult females. RNAi-triggered knock down of BgJHAMT produces a dramatic reduction of JH synthesis, concomitant with a decrease of fat body viteUogenin expression and basal follicle length. BgJHAMT mRNA levels in ca of females along the gonadotrophic cycle parallel, with a slight advancement, JH synthesis profile. BgJHAMT mRNA levels were reduced in starved females and in females in which we reduced nutritional signaling by knocking down insulin receptor and target of rapamycin （TOR）. Results show that conditions that modify JH synthesis in adult B. germanica females show parallel changes of BgJHAMT mRNA levels and that the JH-specifie branch of the JH synthesis pathway is regulated in the same way as the mevalonate branch. Furthermore, we demonstrate that nutrition and its signaling through the insulin receptor and TOR pathways are essential for activating BgJHAMT expression, which suggests that this enzyme can be a checkpoint for the regulation of JH production in relation to nutritional status.

关键词： Blattella germanica corpora allata JHAMT juvenile hormone nutritionalsignaling

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CMOS WLAN Radio Design

CMOS WLAN Radio Design

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2004无线电科学国际会议

作者： Pengfei Zhang RF Micro Devices San jose ca 94555 USA

Using a 5-GHz CMOS direct-conversion wireless local area network (WLAN) transceiver design as an example, this paper describes the RF IC design options and challenges for WLAN applications. Selecti

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THE NEXT MECHANIcaL REVOLUTION AND THE LAWS OF HUMAN NATURE

机械技术史

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机械技术史 1998年 16-40页

作者： C.C.Wang,3E Software,BOX 612345,San jose,ca 95161-2345

The quantum theory developed at the beginning of this century has established the foundation for a law of nature and led to the discovery of DNA and RNA—the codes of *** spectacular successful applications in both medical and agricultural fields,another new frontier is being opened by the researchers at the NASA/Ames research center and elsewhere across the United States to investigate the possibility of imitating the way nature builds organisms for new ways of building machines. Tough questions are therefore raised:can a revolution be raised inside the mechanical domain without the involvement of mechanical engineers? What do today’s mechanical engineers do when the manipulation of atoms/molecules as material building blocks guided by DNA-like replication control becomes successful? Should mechanical engineers at that time warn the next mechanical revolution pioneers the same way as our most trusted computational tool developers have warned us in the use of MSC-NASTRAN:"In the rush to automate,you must keep in mind that no technology available today can take the place of engineering judgement".There was no instruction with regards to how to nurture or to measure one’s engineering *** money incentive hidden in the loopholes of today’s doctrines of democracy,free enterprise, and academic freedom,have formidable power that is far greater than can be *** hidden incentive offers an attractive bonus to those who cheat or goof,but imposes the severest penalty to those who are honest and highly efficient,In competing for profit,the human nature is good at learning shortcuts and being ***,unless there is a balance of power in the form of noble judgement created from within,or very strict disciplines and effective scrutiny imposed to counter-balance acting from without, the outrageous moral trickling down is bound to *** the perfect disciplines and effective scrutiny are very difficulty to establish,the easiest thing

关键词： Next mechanical revolution Laws of human nature

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