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微生物及其质粒在环境中的传播

生物技术通报 1988年第4期 1-6页

作者： stuart b.levy 王璋瑜

抗菌素抗性基因可作为阐明环境微生物间遗传物质自然传播的一种模型。这些基因因为易于识别,并且在人、畜和农业病害的防治上具有医学意义而引人注目。分子生物学与流行病学数据已揭示,这些基因在自然界中惊人地以多种形式发生交流。微... 详细信息

抗菌素抗性基因可作为阐明环境微生物间遗传物质自然传播的一种模型。这些基因因为易于识别,并且在人、畜和农业病害的防治上具有医学意义而引人注目。分子生物学与流行病学数据已揭示,这些基因在自然界中惊人地以多种形式发生交流。微生物间的遗传交换细菌可通过质粒和转座子进行部分DNA交换。质粒本身即使不能在新的寄主中存活,也能将它所编码的一个或多个基因引入该寄主。这些基因可由转座子携带,从进入的质粒跳跃到新寄主的染色体上或者该寄主本身具有的质粒上。这样,该固有质粒或者染色体就获得

关键词：四环素小鸡质粒基因载体转座子抗性基因抗性决定子微生物

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

Modelling the development of biological structures displaying longitudinal geometries in vitro:culturing pluripotent stem cells on plasma-treated,growth factor-coupled polycaprolactone fibres

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Engineered Regeneration 2024年第1期5卷 124-138页

作者： badwi b.boumelhem stuart T.Fraser Syamak Farajikhah Rachel A.Shparberg Michael b.Morris Marcela M.M.bilek Anyu Zhang behnam Akhavan Simon Fleming Maryanne Large School of Physics Faculty of ScienceUniversity of SydneyAustralia Sydney Nano Institute University of SydneyAustralia School of Chemical and biomolecular Engineering University of SydneyAustralia School of Medical Sciences Faculty of Medicine and HealthUniversity of SydneyAustralia School of biomedical Engineering Faculty of EngineeringUniversity of SydneyAustralia School of Engineering University of NewcastleCallaghanNSW 2308Australia Hunter Medical Research Institute(HMRI) Precision Medicine ProgramNew Lambton Heights NSW 2305Australia

Many biological structures such as nerves,blood and lymphatic vessels,and muscle fibres exhibit longitudinal ge-ometries with distinct cell types extending along both the length and width of internal linear *** these three-dimensional structures in vitro is challenging:the best-defined stem-cell differentiation systems are mono-layer cultures or organoids using pluripotent stem *** stem cells can differentiate into functionally mature cells depending on the signals received,holding great promise for regenerative ***,the integration of in vitro differentiated cell types into diseased tissue remains a *** scaffolds can bridge this gap if the appropriate signalling systems are incorporated into the ***,we have taken a biomimicry approach to generate longitudinal structures in *** this approach,mouse embryonic stem cells are directed to differentiate to specific cell types on the surface of polycaprolactone(PCL)fibres treated by plasma-immersion ion implantation and to which with lineage-specifying molecules have been covalently *** demonstrate the simplicity and utility of our method for efficiently generating high yields of the following cell types from these pluripotent stem cells:neurons,vascular endothelial cells,osteoclasts,adipocytes,and cells of the erythroid,myeloid,and lymphoid *** arranged plasma-treated scaffolds with differentiated cell types could ultimately serve as a means for the repair or treatment of diseased or damaged tissue.

关键词： Pluripotent stem cells Lineage commitment Growth factors biomaterial engineering Plasma-immersion ion implantation Covalent biomolecule attachment Polycaprolactone

Rising concentrations of polybrominated diphenyl ethers (PbDEs) in Nigerian foodstuffs despite global restrictions

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Emerging Contaminants 2024年第1期10卷 54-59页

作者： Yulong Ma William A.Stubbings Reginald Cline-Cole Mohamed Abou-Elwafa Abdallah stuart Harrad School of Geography Earthand Environmental SciencesUniversity of BirminghamBirminghamB152TTUK Department of African Studies&Anthropology School of History and CulturesUniversity of BirminghamBirminghamB152TTUK

The presence of brominated flame retardants(bFRs)in foodstuffs of African origin is poorly *** fill this gap,animal-derived food samples comprising 13 different items originally from Nigeria were obtained in 2021,and concentrations of novel brominated flame retardants(NbFRs),polybrominated diphenyl ethers(PbDEs),and hexabromocyclododecane(HbCDD)were *** mean concentrations of NbFRs,PbDEs,and HbCDD in Nigerian foodstuffs were 2.1 ng/g(18 ng/g lipid weight(lw)),1.3 ng/g(9.2 ng/g lw),and 0.42 ng/g(2.8 ng/g lw),with median concentrations of 1.7 ng/g(14 ng/g lw),1.1 ng/g(8.2 ng/g lw),andbFRs than of PbDEs and HbCDDs in Nigerian foodstuffs likely reflect use of NbFRs as substitutes for legacy bFRs in *** with previous dietary studies reveals rising concentrations of PbDEs in Nigerian foodstuffs in recent years with associated rises in dietary exposure,possibly due to active domestic use of PbDEs in ***,comparison of our exposure estimates with health-based limit values suggests adverse health effects of dietary intake of bFRs by Nigerians are unlikely to occur.

关键词： bFRs Alternative flame retardants Dietary exposure Health risks Food

biofabrication of nanocomposite-based scaffolds containing human bone extracellularmatrix for the differentiation of skeletal stem and progenitor cells

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bio-Design and Manufacturing 2024年第2期7卷 121-136页

作者： Yang-Hee Kim Janos M.Kanczler stuart Lanham Andrew Rawlings Marta Roldo Gianluca Tozzi Jonathan I.Dawson Gianluca Cidonio Richard O.C.Oreffo Faculty of Medicine Bone and Joint Research GroupCentre for Human DevelopmentStem Cells and RegenerationInstitute of Developmental SciencesUniversity of SouthamptonSouthampton SO166YDUK School of Pharmacy and biomedical Science University of PortsmouthPortsmouth PO12DTUK School of Engineering Faculty of Engineering and ScienceUniversity of GreenwichGreenwich ME44TBUK Center for Life Nano-and Neuro-Science(CLN2S) Italian Institute of Technology00161 RomeItaly

Autograft or metal implants are routinely used in skeletal ***,they fail to provide long-term clinical resolution,necessitating a functional biomimetic tissue engineering *** use of native human bone tissue for synthesizing a biomimeticmaterial inkfor three-dimensional(3D)bioprintingof skeletal tissueis anattractivestrategyfor ***,human bone extracellular matrix(bone-ECM)offers an exciting potential for the development of an appropriate microenvironment for human bone marrow stromal cells(HbMSCs)to proliferate and differentiate along the osteogenic *** this study,we engineered a novel material ink(LAb)by blending human bone-ECM(b)with nanoclay(L,Laponite®)and alginate(A)polymers using extrusion-based *** inclusion of the nanoﬁller and polymeric material increased the rheology,printability,and drug retention properties and,critically,the preservation of HbMSCs viability upon *** composite of human bone-ECM-based 3D constructs containing vascular endothelial growth factor(VEGF)enhanced vascularization after implantation in an ex vivo chick chorioallantoic membrane(CAM)*** inclusion of bone morphogenetic protein-2(bMP-2)with the HbMSCs further enhanced vascularization and mineralization after only seven *** study demonstrates the synergistic combination of nanoclay with biomimetic materials(alginate and bone-ECM)to support the formation of osteogenic tissue both in vitro and ex vivo and offers a promising novel 3D bioprinting approach to personalized skeletal tissue repair.

关键词： Extracellular matrix Nanoclay bone 3D bioprinting

Human biomonitoring of novel brominated flame retardants:A review on invasive and non-invasive biomarkers

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Emerging Contaminants 2024年第3期10卷 374-385页

作者： Oluwatoyin M.Olagoke Temilola O.Oluseyi Kelechi L.Njoku stuart Harrad Mohamed Abou-Elwafa Abdallah Department of Cell biology and Genetics Faculty of ScienceUniversity of LagosAkokaLagos101017Nigeria Department of Chemistry Faculty of ScienceUniversity of LagosAkokaLagos101017Nigeria School of Geography Earth and Environmental SciencesUniversity of BirminghamBirminghamB152TTUnited Kingdom

Novel brominated flame retardants(NbFRs)are a group of chemicals applied mainly as alternatives to the phased-out polybrominated diphenyl ethers(PbDEs).However,toxicological studies show that NbFRs may pose health risks similar to *** present study reviews available information on the biomonitoring of NbFRs and their metabolites in humans through invasive and non-invasive biomarkers,as well as the toxicological effects of these chemicals both in vivo and in *** general,higher concentrations of NbFRs were reported in tissues of occupationally exposed adults from NbFR production facilities,e-waste recycling facilities and inhabitants living close to these areas,compared to the general *** is worth noting that NbFR human biomonitoring data are limited to few countries located in North America,Europe and Asia,while data from developing countries are *** from in vivo and in vitro toxicity studies show that several NbFRs can cause adverse health effects through various modes of action,mainly:hormone disruption,genotoxicity,endocrine disruption,and behavioural *** few studies have investigated the biotransformation of NbFRs in humans,evidence suggests that the toxicity of some NbFRs may be augmented through their metabolites,as in the case of 2,3,4,5-tetrabromobenzoic acid(TbbA),which may exhibit higher toxicity than its parent compound 2-ethylhexyl-2,3,4,5-tetrabromobenzoate(EH-Tbb).More research is required to assess toxicity thresholds,toxic endpoints,and tolerable intakes for various NbFRs,and their metabolites in *** epidemiological studies are highly recommended to further understand the risk arising from human exposure to different NbFRs,particularly in occupational settings.

关键词： NbFRs Human biomonitoring Human exposure biomarkers Metabolites

2023年美国麻醉医师学会神经肌肉阻滞监测与拮抗实践指南:美国麻醉医师学会工作组关于神经肌肉阻滞的报告

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中华麻醉学杂志 2024年第5期44卷 518-542页

作者： Stephan R.Thilen Wade A.Weigel Michael M.Todd Richard P.Dutton Cynthia A.Lien stuart A.Grant Joseph W.Szokol Lars I.Eriksson Myron Yaster Mark D.Grant Madhulika Agarkar Anne M.Marbella Jaime F.blanck Karen b.Domino 西雅图华盛顿州明尼阿波里斯明尼苏达州达拉斯得克萨斯州密尔沃基威斯康星州教堂山北卡罗来纳州洛杉矶加利福尼亚州斯德哥尔摩瑞典丹佛科罗拉多州绍姆堡伊利诺斯州巴尔的摩马里兰州

本实践指南基于证据提供了全身麻醉期间及术后神经肌肉功能监测与阻滞拮抗的管理推荐。主要关注神经肌肉功能监测的类型与部位及阻滞拮抗的过程,以减少肌肉松弛药残留阻滞。

关键词：神经肌肉阻滞肌肉松弛药神经肌肉功能监测舒更葡糖钠新斯的明

Convective Heat Transfer by Turbulent Melt Flow Excited by Travelling Magnetic Field at the Inductive Heating

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Journal of Iron and Steel Research International 2012年第S2期19卷 771-774页

作者： A.Kapusta A.levy b.Mikhailovich Center for MHD Studies Ben-Gurion University of the Negev Department of Mechanical Engineering Ben-Gurion University of the Negev

We examine a convective dissipation-free heat transfer in melts under the action of a stationary component of electromagnetic body force induced by frequency-modulated travelling magnetic *** influence of MHD paramete... 详细信息

关键词： electromagnetic body force velocity field induction heating external friction model

Simplified seismic fatigue evaluation for rigid steel connections

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Earthquake Engineering and Engineering Vibration 2003年第2期2卷 245-253页

作者： AymanA.Shama John b.Mander stuart.S.Chen Parsons Corporation 100 BroadwayNew York.NY 10005USA Ph.D.P.E Department of Civil Engineering University of CanterburyNew Zealand Professor Department of Civil Structural & Environmental EngineeringState University of New York at BuffaloBuffaloNY 14260USA Associated Professor

A simplified fatigue-life model is proposed for assessing the seismic inelastic rotational capacity of steel *** relations are developed for rigid steel connections under lateral *** this is extended to account for the effects of the welded steel moment frame(WSMF)connections of the so-called pre-Northridge *** seismic fatigue theory is validated against experimental *** experiments were conducted under increasing ductility amplitudes until the onset of ***'rule was used to convert the test results to given an equivalent constant amplitude cyclic fatigue *** agreement is obtained when comparing the experimental observations with the theoretical predictions.

关键词： fatigue cyclic load seismic pile-to-cap moment frames connections steel