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Science China(Technological Sciences) 2002年第5期45卷 467-476页

作者：黄田李亚唐国宝李思维赵兴玉 David.j.Whitehouse derek G.Chetewyn Xianping Liu School of Mechanical Engineering Tianjin University Tianjin 300072 China

This paper presents an error modeling methodology that enables the tolerance design, assembly and kinematic calibration of a class of 3-DOF parallel kinematic machines with parallelogram struts to be integrated into a unified framework. The error mapping function is formulated to identify the source errors affecting the uncompensable pose error. The sensitivity analysis in the sense of statistics is also carried out to investigate the influences of source errors on the pose accuracy. An assembly process that can effectively minimize the uncompensable pose error is proposed as one of the results of this investigation.

关键词： parallel kinematic machine, error modeling, sensitivity analysis, assembly process.

Menaquinone (Vitamin K2) Enhancement of <i>Staphylococcus aureus</i>Biofilm Formation

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j.urnal of Biosciences and Medicines 2014年第1期2卷 26-32页

作者： derek T. Kirby j.yce M. Savage Balbina j. Plotkin Department of Microbiology and Immunology Midwestern University Downers Grove USA

During infection, Staphylococcus aureus is exposed to exogenous menaquinone which is essential for the human blood clotting cascade. The effect of exogenous menaquinone on S. aureus phenotypic expression is not known. To test whether menaquinone affects expression of virulence-associated phenotypes, methicillin-sensitive (MSSA) and -resistant (MRSA) S. aureus strains (n = 8) were grown in the presence of menaquinone (0.001 - 12 μg/ml). Capsule production, biofilm formation (plastic and fibronectin-coated microtiter plates) and carotenoid levels were determined spectrophotometrically after growth in Mueller Hinton broth (MH;24-hr, 37°C). All experiments were, at minimum, done in triplicate and repeated twice. Menaquinone at physiologic levels (0.01 μg/ml MH) significantly increased (p 0.05) biofilm formation on plastic in a manner that was bacterial population size dependent. In addition, menaquinone (0.05 - 4 μg/ml) significantly increased (p 0.05) biofilm formation on fibronectin-coated surfaces for four MSSA strains and one MRSA strain by two to six-fold as compared to medium controls. However, menaquinone had no effect on capsule production or cell-associated carotenoid levels. Menaquinone’s effect on biofilm formation on fibronectin-coated surfaces appears to be regulated by sarA. These findings are the first to demonstrate that a vitamin at concentrations reported in humans affects S. aureus virulence-associated phenotypes.

关键词： Quorum S. aureus Menaquinone Fibronectin Biofilm Capsule Plastic Adherence Carotenoid

Semi-Automated Method for Multi-Tasking Measurement of Microbial Growth, Capsule, and Biofilm Formation

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Advances in Microbiology 2012年第4期2卷 623-628页

作者： derek T. Kirby Craigory j. Raino Samuel F. Rabor j.. Cassandra j. Wasson Balbina j. Plotkin Department of Microbiology and Immunology Midwestern University Downers Grove USA Department of Microbiology and Immunology Midwestern University Downers Grove USA

The maj.rity of bacterial infections involve the formation of biofilms. Biofilm formation is nutrient and growth dependent. Determination of the effects of nutrients on exopolysaccharide production and bacterial growth is labor and time intensive. We tested whether the Bioscreen C (Growth Curves, Inc.) would have utility as a high-throughput tool in the measurement of fundamental phenotype expression, as it relates to growth conditions. Within 48 - 72 hr, reproduceble, statistically significant data on the affects of growth conditions on generation time, capsule production and biofilm formation (maximally for 25 different conditions per 24 hr run cycle;n = 4) were obtained. Although all S. aureus strains produced similar amounts of capsule, sarA– and agr– strains grew significantly slower than parent strain (1.6 fold slower) and produced significantly (p 0.05) less biofilm (~2 fold). E. coli growth rate, biofilm and capsule production in simulated nephropathic urine medium was similar for urine with insulin (20 μU). Addition of insulin to urine medium with proline increased generation time, capsule and biofilm production. Findings from this study show that the Bioscreen C is a rapid, reproducible, and easily manipulated system to concurrently measure bacterial growth, biofilm formation, and capsule production. In addition, there is the potential for further applications of this system by expanding the types of detector dyes used.

关键词： Biofilm Staphylococcus aureus Escherichia coli Quorum-Signaling Compounds Menaquinone Insulin Growth

Hexachlorobenzene Episode in Turkey

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Biomedical and Environmental Sciences 1989年第1期2卷 36-43页

作者： AYHAN GOCMEN HENRY A.PETERS derek j.CRIPPS GEORGE T.BRYAN CARL R.MORRIS Department of Pediatrics School of Medicine University of Hacettepe 06100 Ankara Turkey Center for Health Sciences University of Wisconsin Madison Wisconsin 53706 International Chemical Consultants Alexandria Virginia 22312

During the period 1955-1959, approximately 4000 people in southeast Anatolia developed porphyria due to the ingestion of hexachlorobenzene (HCB), a fungicide added to wheat seedlings. These HCB exposures subsequently led to the development of bullae on sun-exposed areas, hyperpigmentation, hypertrichosis, and porphyrinuria. The condition was called kara yara or 'black sore.' Many of the breast-fed children under the age of 2 years whose mothers had ingested HCB-treated grain died from a disease known as pembe yara or 'pink sore.' In this follow-up study of 252 patients, 20-30 years postexposure, there were 162 males and 90 females, with an average current age of 35.7 years, an average of onset of 7.6 years, and a duration of 2.2 years. Many patients had dermatologic, neurologic, and orthopedic symptoms and signs. The observed clinical findings include scarring of the face and hands (83.7％), hyperpigmentation (65％), hypertrichosis (44.8％), pinched facies (40.1％), painless arthritis (70.2％), small hands (66.6％), sensory shading (60.6％), myotonia (37.9％), cogwheeling (41.9％), enlarged thyroid (34.9％), and enlarged liver (4.8％). Urine and stool porphyrin levels were determined in all patients, and 17 have at least one of the porphyrins elevated. A total of 56 specimens of human milk obtained from mothers with porphyria were analyzed for HCB. The average value was 0.51 ppm in HCB-exposed patients compared to 0.07 ppm in unexposed controls. Offspring of mothers with three decades of HCB-induced porphyria appear normal. 1989 Academic Press, Inc.

关键词： Hexachlorobenzene Episode in Turkey HCB

Experience after 100 patients treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

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World j.urnal of Gastroenterology 2012年第17期18卷 2061-2066页

作者： Ingmar Knigsrainer derek Zieker j.rg Glatzle Olivia Lauk j.lia Klimek Stephan Symons Bj.rn Brücher Stefan Beckert Alfred Knigsrainer Department of Surgery University of TübingenHoppeSeyler-Strasse 3D-72076 TübingenGermany Center for Bioinformatics Tübingen Sand 14D-72076 TübingenGermany

AIM:To investigate perioperative patient morbidity/mortality and outcome after cytoreductive surgery(CRS) and hyperthermic intraperitoneal chemotherapy(HIPEC).METHODS:Of 150 patients 100 were treated with cytoreductive surgery and HIPEC and retrospectively *** and postoperative follow-up data were *** mass index(BMI),age and peritoneal carcinomatosis index(PCI) were chosen as selection criteria with regard to tumor-free survival and perioperative morbidity for this multimodal ***:CRS with HIPEC was successfully performed in 100 out of 150 *** patients were excluded because of intraoperative *** PCI was 17(1-39).In 89% a radical resection(CC0/CC1) was *** patient died postoperatively due to multiorgan *** PCI,age nor BMI was a risk factor for postoperative complications/outcome according to the DINDO *** 9% Re-CRS with HIPEC was performed during the follow-up ***:Patient selection remains the most important *** PCI,age nor BMI alone should be an exclusion criterion for this multimodal therapy.

关键词： Peritoneal carcinomatosis Single-center experience Hyperthermic intraoperative chemotherapy Complications Risk assessment Selection criteria

Novel Identification of LYVE-1 Positive Macrophages in Rheumatoid Synovial Tissue

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Open j.urnal of Rheumatology and Autoimmune Diseases 2016年第3期6卷 74-78页

作者： Lisa j. M. Rump derek L. Mattey Oksana Kehoe j.m Middleton Keele University Arthritis Research Centre at the Robert Jones and Agnes Hunt Orthopaedic Hospital Foundation Trust Oswestry UK Institute for Science and Technology in Medicine Medical School Keele University Stoke-on-Trent UK Haywood Rheumatology Centre Haywood Hospital High Lane Burslem Stoke-on-Trent UK Faculty of Medicine and Dentistry School of Oral and Dental Sciences Bristol University Bristol UK

Obj.ctive: LYVE-1+ macrophages are observed in a range of cancers, where they play a role in tumour lymphangiogenesis. In rheumatoid arthritis (RA), lymphangiogenesis increases in the early stage of the disease and decreases as it progresses, potentially exacerbating inflammatory cell persistence. We investigated whether LYVE-1+ macrophages were present in RA synovium. Methods: Synovial tissue from RA patients was obtained at j.int replacement surgery and immunohistochemistry was performed to visualise LYVE-1+ and CD68+ cells. Results: LYVE-1+ macrophages were present in rheumatoid synovial tissue, the first observation of this kind. Conclusion: Despite the reduction in lymphangiogenesis in chronic RA, LYVE-1 positive macrophages are present and there is a potential role for macrophages in the generation of lymphatic vessels.

关键词： LYVE-1 Macrophage Rheumatoid Arthritis Endothelial Lymphatic

HASTY modulates miRNA biogenesis by linking pri-miRNA transcription and processing

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Molecular Plant 2021年第3期14卷 426-439页

作者： Damian A.Cambiagno Axel j.Giudicatti Agustin L.Arce Delfina Gagliardi Lei Li Wei Yuan derek S.Lundberg Detlef Weigel Pablo A.Manavella Instituto de Agrobiotecnologı´a del Litoral(CONICET-UNL) Ca´tedra de Biologı´a Celular y MolecularFacultad de Bioquı´mica y Ciencias Biolo´gicasUniversidad Nacional del Litoral3000 Santa FeArgentina Department of Molecular Biology Max Planck Institute for Developmental Biology72076 T€ubingenGermany

Post-transcriptional gene silencing mediated by microRNAs(miRNAs)modulates numerous developmental and stress response *** the last two decades,HASTY(HST),the ortholog of human EXPORTIN 5,was considered to be a candidate protein that exports plant miRNAs from the nucleus to the ***,we report that HST functions in the miRNA pathway independent of its cargo-exporting activity in *** found that Arabidopsis mutants with impaired HST shuttling exhibit normal subcellular distribution of ***,protein-protein interaction and microscopy assays showed that HST directly interacts with the microprocessor core component DCL1 through its N-terminal ***,mass spectrometry analysis revealed that HST also interacts independently of its N-terminal domain with the mediator complex subunit *** experiments revealed that HST could act as a scaffold to facilitate the recruitment of DCL1 to genomic MIRNA loci by stabilizing the DCL1-MED37 complex,which in turn promotes the transcription and proper processing of primary miRNA transcripts(primiRNAs).Taken together,these results suggest that HST is likely associated with the formation of the miRNA biogenesis complex at MIRNA genes,promoting the transcription and processing of primiRNAs rather than the direct export of processed miRNAs from the nucleus.

关键词： microRNA gene silencing miRNA nuclear export HASTY miRNA biogenesis

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何时选择堆浸法提金最合适

矿产综合利用 1990年第6期 52-56页

作者： E.j.mclean 刘汉钊

一个已进行过勘探的金矿床,矿石品位、储量和计划的处理量确定后,究竟用炭浆法还是堆浸法处理该矿最合适呢?将两者进行比较,如果用炭浆法多花的基建投资和生产费用能够被其增加的回收率所得到的经济效益弥补,选用炭浆法是合理的。选冶... 详细信息

一个已进行过勘探的金矿床,矿石品位、储量和计划的处理量确定后,究竟用炭浆法还是堆浸法处理该矿最合适呢?将两者进行比较,如果用炭浆法多花的基建投资和生产费用能够被其增加的回收率所得到的经济效益弥补,选用炭浆法是合理的。选冶工艺的选择主要取决于矿石品位,在炭浆法和堆浸法之间有一个临界品位。本文描述年产量15—240万吨矿石的金选冶厂,用资金流动差分析法(differential Cash flow analysis)寻找这一临界品位。

关键词：金矿石堆浸法提取

Sources and environmental fate of pyrogenic polycyclic aromatic hydrocarbons(PAHs)in the Arctic

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Emerging Contaminants 2019年第1期5卷 128-142页

作者： j.nnifer E.Balmer Hayley Hung Yong Yu Robert j.Letcher derek C.G.Muir Arctic Monitoring and Assessment Programme Fram CentrePO Box 6606 Langnes9296TromsøNorway Department of Biology The Citadel171 Moultrie StreetCharlestonSC29409USA Air Quality Processes Research Section Environment and Climate Change Canada4905 Dufferin StreetTorontoOntarioM3H 5T4Canada Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun130102China Ecotoxicology and Wildlife Health Division Environment and Climate Change CanadaNational Wildlife Research CentreCarleton UniversityRaven RoadOttawaOntarioK1A 0H3Canada Environment and Climate Change Canada Canada Centre for Inland Waters867 Lakeshore RoadBurlingtonONL7S 1A1Canada

Polycyclic aromatic hydrocarbons(PAHs)are large class of hydrophobic,semi-volatile organic contaminants that may enter the environment from both natural sources and anthropogenic *** PAHs arise from the incomplete combustion of fossil fuels and organic matter and following dispersal via long-range transport and may subsequently deposit in surface waters,soils and sediments of remote regions,including the *** current review summarizes and discusses Arctic data that is available for combustion-derived PAHs between 2004 and early 2018,focusing largely on data collected from remote,unexploited Arctic regions and from studies that provide some evidence of a pyrogenic *** increasing use of attribution ratios,which aid in discriminating PAHs from petrogenic or pyrogenic sources,suggest PAHs found in Arctic marine waters and sediment predominantly originate from natural underwater seeps,while those measured in air,freshwater,and terrestrial environments are likely to have originated from atmospheric and combustion-derived *** efforts indicate that atmospheric PAHs in the Canadian and Norwegian Arctic are likely to have originated in the northern hemisphere e predominantly from Western Russia,northern Europe,and North *** Asia appears to be a minor source of PAHs to the Arctic,despite contributing more than 50%of global PAH *** comparison to the growing data for atmospheric PAHs,environmental data for these compounds in terrestrial and freshwater environments remain *** have been detected in Arctic biota from terrestrial,freshwater and marine environments,indicating exposure,however,levels are generally low,as most organisms efficiently metabolize parent ***,PAH emissions are expected to decline in the future,however models suggest the Arctic may not experience the same magnitude of decline proj.cted for other world ***,future changes in climate may contribute to a re-volatilizati

关键词： Contaminants Air Biota Pyrogenic Petrogenic Review

Hexachlorobutadiene(HCBD)contamination in the Arctic environment:A review

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Emerging Contaminants 2019年第1期5卷 116-122页

作者： j.nnifer E.Balmer Hayley Hung Katrin Vorkamp Robert j.Letcher derek C.G.Muir Arctic Monitoring and Assessment Programme Fram CentrePO Box 6606 Langnes9296TromsøNorway Department of Biology The Citadel171 Moultrie StreetCharlestonSC29409USA Air Quality Processes Research Section Environment and Climate Change Canada4905 Dufferin StreetTorontoOntarioM3H 5T4Canada Aarhus University Department of Environmental ScienceArctic Research CentreFrederiksborgvej 3994000RoskildeDenmark Ecotoxicology and Wildlife Health Division Environment and Climate Change CanadaNational Wildlife Research CentreCarleton UniversityRaven RoadOttawaOntarioK1A 0H3Canada Environment and Climate Change Canada Canada Centre for Inland Waters867 Lakeshore RoadBurlingtonONL7S 1A1Canada

Hexachlorobutadiene(HCBD)is a halogenated hydrocarbon that is primarily produced as an unintentional byproduct in the manufacture of chlorinated *** between HCBD and other persistent organic pollutants(POPs)led to its listing in 2015 for global regulation under the Stockholm Convention on ***'s toxicity and propensity for long-range transport means there is special concern for its potential impacts on Arctic *** present review comprehensively summarizes all available information of the occurrence of HCBD in the Arctic environment,including its atmospheric,terrestrial,freshwater and marine ecosystems and ***,reports of HCBD in Arctic environmental media are *** has been measured in Arctic air collected from monitoring stations in Finland and Canada,yet there is a dearth of data for other abiotic matrices(***,sediments,glacier ice,freshwaters and seawater).Low HCBD concentrations have been measured in Arctic terrestrial and marine biota,which is consistent with laboratory studies that indicate that HCBD has the potential to bioaccumulate,but not to *** data for Arctic biota suggest that terrestrial birds and mammals and seabirds,have comparatively higher HCBD concentrations than fish and marine mammals,warranting additional *** spatial and temporal trends in HCBD concentrations in the Arctic are currently limited,future monitoring of HCBD in the Arctic will be important for assessing the impact of global regulations newly-imposed by the Stockholm Convention on POPs.

关键词： POPs Air Biota Contaminants Long-range transport Review