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On the experimental characterization of the fluid volume influence on the friction between rough surfaces

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Friction 2023年第7期11卷 1334-1348页

作者： Lukas stahl Michael MÜLLER Georg-Peter OStERMEYER Institute of Dynamics and Vibrations Technische Universität BraunschweigBraunschweig 37106Germany

the load-bearing behaviour of lubricated contacts depends primarily on the normal force,the relative velocity,and the ***,with the aid of the Stribeck curve,it is usually well possible to characterize whether hydrodynamics,mixed friction,or boundary friction is more likely to be *** fact that the load regime can also depend on the fluid quantity is obvious,but has hardly been systematically investigated so *** for contacts with microscopic roughness,the defined application of a very small amount of fluid is a very challenging *** this paper,a very fundamental study shows how a pin-on-disc tribometer can be used to achieve the transition from dry friction via mixed friction to predominant hydrodynamics by the amount of supplied *** experiments are carried out on samples filed with different *** addition,the simultaneous influence of partial filling and normal force as well as relative velocity is also *** good reproducibility has been practically reached over the entire range of the *** the quantities for the coefficient of friction(COF),it was concluded that close to full filling,a reduction of the fluid quantity has a similar effect on the COF as the reduction of the *** property goes along with the common theory of starved lubricated *** behaviour was not observed to the same extent for the normal *** the vicinity of smaller fluid quantities,the COF increases very rapidly with further reduction in fluid quantity,far more disproportionately than that with reduction in *** a deeper understanding of this problem,various practical issues such as idling or the run-up process in bearings can also be studied in a more focused manner.

关键词： starved lubrication Stribeck curve pin-on-disc tribometer fluid supply experimental studies

Androgen receptor gene CAG and GGN repeat lengths as predictors of recovery of spermatogenesis following testicular germ cell cancer treatment

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Asian Journal of Andrology 2017年第5期19卷 538-542页

作者： karolina Bogefors Yvonne Lundberg Giwercman Jakob Eberhard Olof stahl Eva Cavallin-stahl Gabriella Cohn-Cedermark Stefan Arver Aleksander Giwercman Reproductive Medicine Centre Skane University Hospital Malmo Sweden Department of Oncology Skane University Hospital Malmo Sweden Department of translational Medicine Lund University Malmo Sweden Department of Oncology Skane University Hospital Lund Sweden Radiumhemmet Karolinska HospitalStockholm Sweden Centre of Andrology and Sexual Medicine Karolinska Hospital Stockholm Sweden

Spermatogenesis is an androgen-regulated process that depends on the action of androgen receptor （AR）. Sperm production may be affected in men treated for testicular cancer （tC）, and it is important to identify the factors influencing the timing of spermatogenesis recovery following cancer treatment. It is known that the CAG and GGN repeat numbers affect the activity of the AR; therefore, the aim of this study is to investigate if the CAG and GGN polymorphisms in the AR gene predict recovery of sperm production after tC treatment. tC patients （n = 130） delivered ejaculates at the following time points： postorchiectomy and at 6, 12, 24, 36, and 60 months posttherapy （tO, t6, t12, t24, t36, and t60）. the CAG lengths were categorized into three groups, 〈22 CAG, 22-23 CAG, and 〉23 CAG, and the GGN tracts were also categorized into three groups, 〈23 GGN, 23 GGN, and 〉23 GGN. At t12, men with 22-23 CAG presented with a statistically significantly （P = 0.045） lower sperm concentration than those with other CAG numbers （8.4 × 10^6 ml^-1 vs 16 × 10^6 ml^-1; 95% CI： 1.01-2.65）. this association was robust to omitting adjustment for treatment type and sperm concentration at tO （P= 0.021; 3.7× 10^6 ml^-1 vs 10 × 10^6 ml^-1; 95% CI： 1.13-4.90）. the same trends were observed for total sperm number. the least active AR variant seems to be associated with a more rapid recovery of spermatogenesis. this finding adds to our understanding of the biology of postcancer therapy recovery of fertility in males and has clinical implications.

关键词： androgen receptor CAG and GGN repeat sperm number testicular cancer

Senescence-specific Alteration of Hydrogen Peroxide Levels in Arabidopsis thaliana and Oilseed Rape Spring Variety Brassica napus ***

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Journal of Integrative Plant Biology 2012年第8期54卷 540-554页

作者： Stefan Bieker Lena Riester Mark stahl Jürgen Franzaring Ulrike Zentgraf ZMBP (Center for Plant Molecular Biology) University of TübingenAuf der Morgenstelle 2872076 Tübingen Germany Institute for Landscape and Plant Ecology kologiezentrum 2August-von-Hartmann-Str.370599 StuttgartGermany

In order to analyze the signaling function of hydrogen peroxide （H202） production in senescence in more detail, we manipulated intracellular H202 levels in Arabidopsis thaliala （L.） Heynh by using the hydrogen- peroxide-sensitive part of the Escherichia coil transcription regulator OxyR, which was directed to the cytoplasm as well as into the peroxisomes. H202 levels were lowered and senescence was delayed in both transgenic lines, but OxyR was found to be more effective in the cytoplasm. to transfer this knowledge to crop plants, we analyzed oilseed rape plants Brassica napus L. cv. Mozart for H20~ and its scavenging enzymes catalase （CAt） and ascorbate peroxidase （APX） during leaf and plant development. H202 levels were found to increase during bolting and flowering time, but no increase could be observed in the very late stages of senescence. With increasing H202 levels, CAt and APX activities declined, so it is likely that similar mechanisms are used in oilseed rape and Arabidopsis to control H202 levels. Under elevated CO2 conditions, oilseed rape senescence was accelerated and coincided with an earlier increase in H202 levels, indicating that H202 may be one of the signals to inducing senescence in a broader range of Brassicaceae.

关键词： Arabidopsis thaliana Brassica napus E. coil Oxy-RD intracellular hydrogen peroxide senescence phenotype catalase ascorbatePeroxidase elevated CO2.

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the Interaction of the Arabidopsis Response Regulator ARR18 with bZIP63 Mediates the Regulation of PROLINE DEHYDROGENASE Expression

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Molecular Plant 2014年第10期7卷 1560-1577页

作者： Manikandan Veerabagu tobias kirchler kirstin Elgass Bettina Stadelhofer Mark stahl klaus Harter Virtudes Mira-Rodado Christina Chaban Department of Plant Physiology Center for Plant Molecular Biology (ZMBP) University of T~bingen Auf der Morgenstelle 32 72076Tubingen Germany Present address: Department of Biology Norwegian University of Science and Technology (NTNU) Hogskoleringen 5 7491- Trondheim Norway Present address: Biochemistry Department Physical Science 4 La Trobe University Bundoora VIC 3086 Australia Central Facilities Analytics ZMBP University of Tubingen Auf der Morgenstelle 32 Tubingen Germany

As the first and rate-limiting enzyme of proline degradation, PROLINE DEHYDROGENASE1 （PDH1） is tightly regulated during plant stress responses, including induction under hypoosmolarity and repression under water deficit. the plant receptor histidine kinases AHks, elements of the two-component system （tCS） in Arabidopsis thaliana, are pro- posed to function in water stress responses by regulating different stress-responsive genes. However, little information is available concerning AHk phosphorelay-mediated downstream signaling. Here we show that the Arabidopsis type-B response regulator 18 （ARR18） functions as a positive osmotic stress response regulator in Arabidopsis seeds and affects the activity of the PDH1 promoter, known to be controlled by C-group bZlP transcription factors. Moreover, direct physical interaction of ARR18 with bZIP63 was identified and shown to be dependent on phosphorylation of the conserved aspar- tate residue in the ARR18 receiver domain. We further show that bZlP63 itself functions as a negative regulator of seed germination upon osmotic stress. Using reporter gene assays in protoplasts, we demonstrated that ARR18 interaction negatively interferes with the transcriptional activity of bZIP63 on the PDH1 promoter. Our findings provide new insight into the function of ARR18 and bZIP63 as antagonistic regulators of gene expression in Arabidopsis.

关键词： two-component system osmotic stress bZIP63 ARR18 protein interaction transcription activation Arabidopsis thaliana.

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接触斑点对蜗轮副承载能力的影响

机械传动 2014年第10期38卷 9-13,17页

作者： Hermes J. Hhn B.-R. stahl k. Monz A. 陈金山 SEW-Eurodrive传动设备德国有限公司德国布鲁克塞尔76646 慕尼黑工业大学齿轮研究中心(FZG) 德国加兴85748 德国IMO集团公司德国格蕾姆斯多夫91350 浙江台玖精密机械有限公司浙江嘉兴314500

根据现有的技术发展水平,只有当蜗轮副的齿面完全啮合,才能评估其抗点蚀能力。但实际上,在蜗轮与蜗杆初始啮合时,它们只有一个较小的啮合斑点。由于时间和经费的关系,通过长时间轻载跑合使其达到完全啮合一般不太可能。在初期,由于接触... 详细信息

根据现有的技术发展水平,只有当蜗轮副的齿面完全啮合,才能评估其抗点蚀能力。但实际上,在蜗轮与蜗杆初始啮合时,它们只有一个较小的啮合斑点。由于时间和经费的关系,通过长时间轻载跑合使其达到完全啮合一般不太可能。在初期,由于接触面较小,齿部的接触应力会很大,有可能会在啮合处的表面产生一条微观裂纹,随后裂纹继续发展使材料从蜗轮上剥落,从而形成点蚀。较小的啮合斑点与点蚀的关系迄今还没有被系统的分析与研究,因此蜗轮轮齿也不能很好的进行优化。通过理论和实践相结合,提一种新的、可适用于不同尺寸、不同接触斑点位置以及齿形的计算方法,以弥补这一空白领域。

关键词：蜗轮蜗杆点蚀

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VERNAUZAtION1 Modulates Root System Architecture in Wheat and Barley

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Molecular Plant 2018年第1期11卷 226-229页

作者： kai P. Voss-Fels Hannah Robinson Stephen R. Mudge Cecile Richard Saul Newman Benjamin Wittkop Andreas stahl Wolfgang Friedt Matthias Frisch lulian Gabur Anika Miller-Cooper Bradley C. Campbell Alison kelly Glen Fox Jack Christopher Mandy Christopher karine Chenu Jerome Franckowiak Emma S. Mace Andrew k. Borrell Howard Eagles David R. Jordan Jose R. Botella Graeme Hammer lan D. Godwin Ben trevaskis Rod J. Snowdon Lee t. Hickey Department of Plant Breeding IFZ Research Centre for Biosystems Land Use and Nutrition Justus Uebig University Heinrich-Buff-Ring 26-32 35392 Giessen Germany Queensland Alliance for Agriculture and Food Innovation The University of Queensland St Lucia QLD 4072 Australia School of Agriculture and Food Sciences The University of Queensland Brisbane QLD 4072 Australia CSIRO Agriculture Canberra ACT 2601 Australia Department of Biometry and Population Genetics IFZ Research Centre for Biosystems Land Use and Nutrition Justus Liebig University Heinrich-Buff-Ring 26-32 35392 Giessen Germany Department of Agriculture and Fisheries Leslie Research FacilRy Toowoomba QLD 4350 Australia Queensland Alliance for Agriculture and Food Innovation The University of Queensland roowoomba QLD 4350 Australia Department of Agronomy and Plant Genetics University of Minnesota St Paul MN USA Department of Agriculture and Fisheries Hermitage Research Facility Warwick QLD 4370 Australia Queensland Alliance for Agriculture and Food Innovation Hermitage Research Facility The University of Queensland Warwick QLD 4370 Australia these authors contributed equally to this article.

Dear Editor Roots play a key role in plant growth regulation. It is well described that the below-ground plant architecture has a significant impact on plant performance under abiotic constraints and maintains stabili... 详细信息

关键词： tRAItS RESPONDS

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卧式螺旋沉降离心机操作的最优化

化工装备技术 1991年第5期12卷 43-47页

作者： F.Reif W.stahl t.Langeloh 马泽民四川江北离心机研究所

研究卧式螺旋沉降离心机时涉及到三个主要问题:澄清、脱水和能否卸渣。后者与输渣扭矩和动力消耗密切相关。目前上述所有问题都被作者解决。本文论述了如何改善该离心机的操作,并使这种离心机的效率得以提高。同时进一步指出,最优化必... 详细信息

研究卧式螺旋沉降离心机时涉及到三个主要问题:澄清、脱水和能否卸渣。后者与输渣扭矩和动力消耗密切相关。目前上述所有问题都被作者解决。本文论述了如何改善该离心机的操作,并使这种离心机的效率得以提高。同时进一步指出,最优化必须考虑对机器和物料的特定要求。本文首先介绍了适用于结晶状物料的不同的模型,最后给出了影响结构和操作的重要结果。

关键词：卧式螺旋沉降离心机操作最优化分离

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Spatial H202 Signaling Specificity： H202 from Chloroplasts and Peroxisomes Modulates the Plant transcriptome Differentially

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Molecular Plant 2014年第7期7卷 1191-1210页

作者： Nasser Sewelam Nils Jaspert katrien Van Der kelen Vanesa B. tognetti Jessica Schmitz Henning Frerigmann Elia stahl Frank Van Breusegem Veronica G. Maurino Institut of Developmental and Molecular Biology of Plants Plant Molecular Physiology and Biotechnology Group Heinrich-Heine-Universit~t Universit~tsstraBe 1 40225 D~sseldorf Germany Botany Department Faculty of Science Tanta University 31527 Tanta Egypt Department of Plant Systems Biology VIB and Department of Plant Biotechnology and Bioinformatics Ghent UniversityTechnologiepark 927 B-9052 Gent Belgium Present address: Mendel Centre for Plant Genomics and Proteomics CEITEC--Central European Institute of Technology MasarykUniversity Kamenice 5 CZ-62500 Brno Czech Republic Botanical Institute Cologne Biocenter University of Cologne 50674 Cologne Germany Cluster of Excellence on Plant Sciences (CEPLAS) 40225 Dusseldorf and 50674 Cologne Germany Molecular Ecophysiology of Plants Heinrich-Heine-Universitat Universitatsstraf3e 1 40225 D~sseldorf Germany

Hydrogen peroxide （H2O2） operates as a signaling molecule in eukaryotes, but the specificity of its signal- ing capacities remains largely unrevealed. Here, we analyzed whether a moderate production of H2O2 from two different plant cellular compartments has divergent effects on the plant transcriptome. Arabidopsis thaliana overexpressing glycolate oxidase in the chloroplast （Fahnenstich et al., 2008; Balazadeh et al., 2012） and plants deficient in peroxisomal catalase （Queval et al., 2007; Inze et al., 2012） were grown under non-photorespiratory conditions and then transferred to photorespiratory conditions to foster the production of H202 in both organelles. We show that H202 originating in a specific organelle induces two types of responses： one that integrates signals independently from the subcellular site of H202 production and another that is dependent on the H2O2 production site. H2O2 produced in peroxisomes induces transcripts involved in protein repair responses, while H2O2 produced in chloroplasts induces early signaling responses, including transcription factors and biosynthetic genes involved in production of secondary signaling messengers. there is a significant bias towards the induction of genes involved in responses to wounding and pathogen attack by chloroplas- tic-produced H202, including indolic glucosinolates-, camalexin-, and stigmasterol-biosynthetic genes. these transcriptional responses were accompanied by the accumulation of 4-methoxy-indol-3-ylmethyl glucosinolate and stigmasterol.

关键词： hydrogen peroxide reactive oxygen species glycolate oxidase catalase photorespiration oxidative signaling.

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你不知道的达·芬奇的十五件事

当代外语研究 2006年第7期 31-33页

作者： Jason stahl Alex Stone 刘略昌上海水产大学外语学院

1．列奥那多是农家女卡泰丽娜和律师兼地主塞尔·皮耶罗的私生子。他是在家上的学, 缺乏希腊语和拉丁语的正规教育。 2．他是一个技艺娴熟的七弦琴演奏家。初次在米兰宫廷露面时,列奥那多是位乐师。

关键词：蒙娜丽莎月亮自画像推测方案设计图面部识别软件地球比尔·盖茨美元

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