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4444篇 您的检索式:作者名="Lorenz"
    题名 作者 年代 出处 被引量
1评价湖泊富营养化的一个综合模型(英文)显示文摘湖泊富营养化的评价 ,即确定水体的状态属性 ,实际上是一个将定性问题定量化的多变量的综合决策过程 ,因此 ,对湖泊的富营养化程度进行评价应以综合评价为主 .在综述国内外若干综合评价方法的基础上 ,指出营养状态指数 (TSI)法应可作为湖泊富营养化评价的主要方法 ,因其可对湖泊的营养状态进行连续的数值化分级 ,从而为富营养化机理的定量研究提供坚实基础 .采用层次分析 (AHP)法确定综合评价指标中的权重分配 ,构建一综合评价模型 :TSI =W (Chla)×TSI(Chla) +W (Sd)×TSI(Sd) +W (TP)×TSI(TP)或TSIM=W (Chla)×TSIM(Chla) +W (Sd)×TSIM(Sd) +W (TP)×TSIM(TP) .此外 ,文中简要讨论了综合评价与其他统计方法如聚类分析的关系 .蔡庆华 刘建康 Lorenz King 2002应用生态学报2002,13,12:68
2MicroRNA let-7b targets important cell cycle molecules in malignant melanoma cells and interferes with anchorage-independent growth显示文摘一幅 microRNA 表示屏幕被执行从良性的 melanocytic nevi 在 laser-microdissected 纸巾分析 157 不同 microRNAs (n = 10 ) 并且主要恶意的黑瘤(n = 10 ) ,用量的即时 PCR。微分表示被作出对有利的裁决 72 microRNAs。microRNAs 的 let-7 家庭的成员是显著地, down 作为与良性的 nevi 相比在主要黑瘤调整了,为是的这些分子的一个可能的角色暗示肿瘤在恶意的黑瘤压制 ors。有趣地,类似的调查结果为肺和结肠癌被描述了。在黑瘤房间试管内 down 的 let-7b 的 Overexpression 调整了 cyclins 的表示 D1, D3,和 A,和 cyclin 依赖的 kinase (Cdk ) 4,所有哪个被描述了在黑瘤开发起一个作用。蛋白质表示上的 let-7b 的效果由于单个 mRNAs 的 3'-untranslated 区域(3'UTRs ) 指向,为 cyclin D1 由记者基因分析例示。与它细胞周期管理者上的 down modulating 效果一致, let-7b 禁止了细胞周期前进和黑瘤细胞的抛锚无关的生长。总起来说,这些调查结果不仅指向早黑瘤开发的新规章的机制,而且可以打开大街因为未来指向了这个肿瘤的治疗。Julia Schultz Peter Lorenz Gerd Gross Saleh Ibrahim Manfred Kunz 2008Cell Research2008,18,5:45
320世纪重大自然灾害评析显示文摘人类在科学技术上取得了辉煌成绩的同时,在认识自然和改造自然方面也得到了教训和新的认识、这一教训主要是来自自然灾害。根据收集到的全球自然灾害有关数据,对20世纪全球主要自然灾害特征和分布特点进行了分析,并对其成因提出了看法。王润 姜彤 Lorenz King Marco Gemmer Anja Holl 2000自然灾害学报2000,9,4:37
4The epidemiology of norovirus gastroenteritis in China:disease burden and distribution of genotypes显示文摘With the improvements of sanitation and nationwide safe water supply the occurrence of bacterial diarrhea declined remarkably,while viruses became the leading causes of acute gastroenteritis(AGE).Of these viruses,noroviruses(NoVs)are responsible for a considerable burden of gastroenteritis,especially in children<2 years and elderly≥65 years.NoVs circulating in the Chinese population are antigenically highly diverse with the genotype GII.4 being the dominant strain followed by GII.3.Given the widespread contamination in environmental sources,and highly infectious nature of NoVs,vaccination would be the desirable strategy for the control of NoV infections.However,a better understanding of acquired immunity after infection,and a reliable immunological surrogate marker are urgently needed,since two vaccine candidates based on virus-like particles(VLPs)are currently moving into clinical evaluations in China.Honglu Zhou Songmei Wang Lorenz von Seidlein Xuanyi Wang 2020Frontiers of Medicine2020,14,1:28
5冠状动脉内影像学临床应用专家共识(第一部分):对冠状动脉介入治疗的指导与优化显示文摘欧洲心血管介入协会(EAPCI)专家组系统总结了血管内超声(IVUS)和光学相干断层成像(OCT)这两种血管内影像学检查临床应用指征的现有证据,提供了关于IVUS和OCT指导经皮冠状动脉介入治疗(PCI)的应用价值,并明确了最可能从腔内影像学指导的介入治疗中获得临床收益的患者或病变类型,同时详细论述了PCI前如何使用IVUS或OCT优化支架尺寸(支架长度和直径)和手术策略的选择。此外,专家推荐对支架失败(支架内再狭窄或支架内血栓形成)的患者应常规进行冠状动脉内影像学检查,并首选OCT。最后,重点论述了IVUS和OCT在指导PCI和评估支架失败两个方面的优势和局限性,并对未来需要深入研究的领域进行了展望。Lorenz Raber Gary S Mintz Konstantinos C Koskinas Thomas W Johnson Niels R Holm Yoshinubo Onuma Maria D Radu Michael Joner Bo Yu Haibo Jia Nicolas Meneveau Jose M.de la Torre Hemandez Javier Escaned Jonathan Hill Francesco Prati Antonio Colombo Carlo di Mario Evelyn Regar Davide Capodanno William Wijns Robert A Byme Giulio Guagliumi 2019中华心血管病杂志2019,47,1:17
6Land Use Change and Causes in the Xiangxi Catchment, Three Gorges Area Derived from Multispectral Data显示文摘The construction of the Three Gorges Dam on the Yangtze River has extensive impact on the ecosystems and the population of the Three Gorges Area (TGA). Inundation and resettlement have induced far-reaching land use and land cover change (LUCC). The areas that are affected by measures of resettlement are in a tense situation between the implementation of various governmental tasks addressing sustainable land use and water retention and the fulfilment of the population’s economic needs, which primarily depend on agricultural production. Destabilization of slopes and soil erosion are immediate hazards induced by the impoundment. Farming is a very important source of income and has to persist on the one hand to assure the income of the rural population. On the other hand, the environment has to be protected from runoff, soil erosion and instabilities connected to relief, geology and hydraulic influences. In this study, supervised classifications are performed using Landsat-TM (1987 and 2007) and ASTER (2007) images. LUCC is assessed by post-classification change analysis. On the catchment scale, arable land has decreased significantly, while garden land (citrus orchards) and woodland have increased. LUCC mainly affects the area surrounding the reservoir ('backwater') of the Xiangxi ( 香溪 ) River, driven by local resettlement, newly built infrastructure, relocation of land cultivation, and conversion of arable land to garden land. In the hinterland, LUCC occurs in form of abandonment of land cultivation as a consequence of the Grain-forGreen programme.Christoph Seeber Heike Hartmann 项伟 Lorenz King 2010Journal of Earth Science2010,21,6:12
7A concept for multiterawatt fibre lasers based on coherent pulse stacking in passive cavities显示文摘Since the advent of femtosecond lasers,performance improvements have constantly impacted on existing applications and enabled novel applications.However,one performance feature bearing the potential of a quantum leap for high-field applications is still not available:the simultaneous emission of extremely high peak and average powers.Emerging applications such as laser particle acceleration require exactly this performance regime and,therefore,challenge laser technology at large.On the one hand,canonical bulk systems can provide pulse peak powers in the multi-terawatt to petawatt range,while on the other hand,advanced solid-state-laser concepts such as the thin disk,slab or fibre are well known for their high efficiency and their ability to emit high average powers in the kilowatt range with excellent beam quality.In this contribution,a compact laser system capable of simultaneously providing high peak and average powers with high wall-plug efficiency is proposed and analysed.The concept is based on the temporal coherent combination(pulse stacking)of a pulse train emitted from a high-repetition-rate femtosecond laser system in a passive enhancement cavity.Thus,the pulse energy is increased at the cost of the repetition rate while almost preserving the average power.The concept relies on a fast switching element for dumping the enhanced pulse out of the cavity.The switch constitutes the key challenge of our proposal.Addressing this challenge could,for the first time,allow the highly efficient dumping of joule-class pulses at megawatt average power levels and lead to unprecedented laser parameters.Sven Breitkopf Tino Eidam Arno Klenke Lorenz von Grafenstein Henning Carstens Simon Holzberger Ernst Fill Thomas Schreiber Ferenc Krausz Andreas Tunnermann Ioachim Pupeza Jens Limpert 2014Light(Science & Applications)2014,3,1:11
8工业4.0时代的人机关系:技术将如何改变工业劳动力结构显示文摘从现在到2025年,工业4.0将推动现有的工业劳动力结构发生巨大的转变。数字化工业技术将会削减一定数量的工作岗位,但同时也将带来更多的就业机会,此外,对劳动者的技能要求与过去相比将会有极大的差别。想要顺利过渡到工业4.0,企业需要对员工进行再培训,改进组织架构,并制定战略性的人才计划。Markus Lorenz Michael Rüβmann 2016中国工业评论2016,0,10:7
9TBCs for Gas Turbines under Thermomechanical Loadings: Failure Behaviour and Life Prediction显示文摘Tilmann Beck Olena Trunova Roland Herzog Lorenz Singheiser 2013Journal of Energy and Power Engineering2013,7,4:7
10甲苯二异氰酸酯(TDI)致癌性的综合评估显示文摘甲苯二异氰酸酯(TDI)被数家机构分类为可能的人类致癌物,其主要依据为动物实验发现对啮齿动物经灌胃暴露TDI后肿瘤发生率升高。基于研究结果的可靠性以及一致性,综合评估了现有研究数据是否支持这一分类。结果显示现有的流行病学数据不足以有力证明TDI为人类致癌物。动物实验研究表明,吸入接触TDI并不导致肿瘤发生。经灌胃暴露后观察到的肿瘤很可能是由于TDI转化为已知的啮齿动物致癌物甲苯二胺(TDA)所致。在TDI吸入暴露的体内实验中,当由TDI转化生成的TDA不能达到具有显著生物学效应的浓度时,TDI对啮齿动物或人类都没有遗传毒性。由于哺乳动物在生理性接触条件下TDI不能转变成TDA,所以对人类而言,TDI接触与致癌效应之间无直接的显著因果关系。因此虽然在如灌胃等非生理暴露的条件下,TDI可能的人类致癌物的分类是正确的,但本文对其致癌研究数据的合理评估和正确理解有助于将产品监管力度集中于与职业暴露更相关的有害健康效应上。Robyn L.Prueitt Lorenz R.Rhomberg 管娜 Julie E.Goodman 金小伟 2016生态毒理学报2016,11,4:6
11Spatio-temporal characteristics of cultivated land fragmentation in different landform areas with a case study in Northeast China显示文摘Assessing the temporal and spatial characteristics of cultivated land fragmentation is necessary to identify management practices that can reduce negative environmental effects.Thus,the purpose of this study was to use principal component analysis and spatial autocorrelation to analyze the dynamic characteristics of cultivated land fragmentation in different landform areas in Liaoning Province,China,in terms of time and space.An additional objective was to match the changes with the natural and social environment to support the sustainable development of fragmented cultivated land.The results indicated that the evolutionary trends of cultivated land fragmentation in the central plain area showed a weakening trend,contrary to those observed in the western hilly and eastern mountainous areas.Moreover,the spatial distribution characteristics of cultivated land fragmentation in the western hilly area were generally“external low,internal high,”primarily because of the edge density of cultivated land patches.The spatial distribution characteristics of cultivated land fragmentation in the central plain area were generally“external high,internal low,”primarily because of the number and division of cultivated land patches.The spatial distribution characteristics of cultivated land fragmentation in the eastern mountainous area were generally“south low,north high”because of the division of cultivated land patches.These results can provide guidelines for planners,managers,decision-makers and others to formulate regulatory policies,identify land remediation areas,and promote the sustainable development of cultivated land.Fengkui Qian Yanru Chi Rattan Lal Klaus Lorenz 2020Ecosystem Health and Sustainability2020,6,1:6
122008年欧洲数字出版发展概况和趋势显示文摘在全球数字化和网络化浪潮中,欧洲的互联网应用发展迅速,可以说达到非常普及的程度,比如,截至2007年底,法国的互联网用户数达到3090万人,占全国人口的50.6%,德国的互联网用户数达到4200万人,占全国人口的51%,远远高于世界平均水平。陈少华 Lorenz Lorenz-Meyer 2008出版广角2008,,12:6
13为恶意、良性的胆汁的苛评的治疗的充分盖住的自我可扩充的金属 stents显示文摘 AIM:To present a series of covered self-expandable metal stents(CSEMS) placed for different indications and to evaluate the effectiveness,complications and extractability of these devices.METHODS:We therefore retrospectively reviewed the courses of patients who received CSEMS due to malignant as well as benign biliary strictures and postsphincterotomy bleeding in our endoscopic unit between January 2010 and October 2011.RESULTS:Twenty-six patients received 28 stents due to different indications(20 stents due to malignant biliary strictures,six stents due to benign biliary strictures and two stents due to post-sphincterotomy bleeding).Biliary obstruction was relieved in all cases,regardless of the underlying cause.Hemostasis could be achieved in the two patients who received the stents for this purpose.Complications occurred in five patients(18%).Two patients(7%) developed cholecystitis,stents dislocated/migrated in other two patients(7%),and in one patient(3.6%) stent occlusion was documented during the study period.Seven stents were extracted endoscopically.Removal of stents was easily possible in all cases in which it was desired using standard forceps.Twelve patients underwent surgery with pylorus preserving duodenopancreatectomy.In all patients stents could be removed during the operation without difficulties.CONCLUSION:Despite the higher costs of these devices,fully covered self-expanding metal stents may be suitable to relief biliary obstruction due to bile duct stenosis,regardless of the underlying cause.CSEMS may also represent an effective treatment strategy of severe post-sphincterotomy bleeding,not controlled by other measures.Ahmed Abdel Samie Stephan Dette Ulrich Vhringer Michael Stumpf Karolin Kopischke Lorenz Theilmann 2012World Journal of Gastrointestinal Endoscopy2012,4,9:5
14Treatment of biliary tract cancer with NVP-AEW541:Mechanisms of action and resistance显示文摘AIM:To investigate in vitro treatment with NVPAEW541,a small molecule inhibitor of insulin-like growth factor-1 receptor(IGF-1R),in biliary tract cancer (BTC),since this disease is associated with a poor prognosis due to wide resistance to chemotherapeutic agents and radiotherapy.METHODS:Cell growth inhibition by NVP-AEW541 was studied in vitro in 7 human BTC cell lines by automated cell counting.In addition,the anti-tumoral mechanism of NVP-AEW541 was studied by Western blotting,cell cycle analysis and reverse transcription-polymerase chain reaction(RT-PCR).Anti-tumoral drug effect in combination with gemcitabine,5-fluorouracil(5-FU)and Polo-like kinase 1 inhibitor BI2536 was also studied. RESULTS:In vitro treatment with NVP-AEW541 suppressed growth in all human BTC cell lines,however response was lower in gallbladder cancer.Treatment withNVP-AEW541 was associated with dephosphorylation of IGF-1R and AKT.In contrast,phosphorylation of p42/p44 and Stat3 and expression of Bcl-xL were inconsistently downregulated.In addition,treated cells showed cell cycle arrest at the G1/S-checkpoint and an increase in sub-G1 peak.Moreover,IGF-1R and its ligands IGF-1 and IGF-2 were co-expressed in RT-PCR,suggesting an autocrine loop of tumor cell activation.Combined with gemcitabine,NVP-AEW541 exerted synergistic effects, particularly at low concentrations,while effects of combination with 5-FU or BI 2536 were only additive. CONCLUSION:Our findings suggest that NVP-AEW541 is active against BTC in vitro and potentiates the efficacy of gemcitabine.Samuel Wolf Jana Lorenz Joachim Mssner Marcus Wiedmann 2010World Journal of Gastroenterology2010,16,2:5
15太湖流域北部潜在洪涝风险区分析及影响评估显示文摘太湖流域历来遭受严重的洪涝灾害,并且近年来有不断加重的趋势。本文选择太湖流域北部的无锡市作为典型研究地区,研究其洪涝的危险性并进行潜在损失评估。人类活动,包括修筑圩区、森林破坏、人口增长、城市化等,对这个地区的洪涝形势有较大的影响;自然条件的变化使河道水位升高,洪涝历时缩短,洪峰增高。本文选择不同回归年(2,5,10,20,50年),结合地理信息系统分析模型,计算了潜在洪涝危险区域和洪涝损失,主要结论为:(1)人类活动已经改变了自然的洪涝形势,增大了汇流和洪涝;(2)洪涝危险区与降雨中心有关;(3)筑圩成功地保护了圩内的土地,缩短了洪涝历时,增高了圩外河道的洪涝水位;(4)经济发展使洪涝损失增加。高俊峰 Lorenz King 姜彤 王润 2002自然灾害学报2002,11,4:5
16Stochastic resonance whole body vibration reduces musculoskeletal pain:A randomized controlled trial显示文摘AIM:To examined the effects of stochastic resonance whole-body vibration training on musculoskeletal pain in young healthy individuals.METHODS:Participants were 43 undergraduate students of a Swiss University.The study was designed as a randomized controlled trial(RCT)with randomized group allocation.The RCT consisted of two groups each given 12 training sessions during four weeks with either 5 Hz-Training frequency(training condition)or 1.5 Hz Training frequency(control condition).Outcome was current musculoskeletal pain assessed in the evening on each day during the four week training period.RESULTS:Multilevel regression analysis showed musculoskeletal pain was significantly decreased in the training condition whereas there was no change in the control condition(B=-0.023,SE=0.010,P=0.021).Decrease in current musculoskeletal pain over four weeks was linear.CONCLUSION:Stochastic resonance whole-body vibration reduced musculoskeletal pain in young healthy individuals.Stochastic resonance vibration and not any other exercise component within training caused pain reduction.Achim Elfering Jan Thomann Volker Schade Lorenz Radlinger 2011World Journal of Orthopedics2011,2,12:4
172000年全球重大自然灾害概述显示文摘2000年是全球自然灾害经济损失较为一般的年份。根据收集到的全球自然灾害记录的数据,客观地对全球主要自然灾害的特征和分布特点进行了分析,并对其成因进行了探讨.姜彤 王润 Lorenz KING 2002自然灾害学报2002,11,1:4
18Stochastic resonance whole body vibration increases perceived muscle relaxation but not cardiovascular activation:A randomized controlled trial显示文摘AIM To investigate the acute effects of stochastic resonance whole body vibration(SR-WBV), including muscle relaxation and cardiovascular activation.METHODS Sixty-four healthy students participated. The participants were randomly assigned to sham SR-WBV training at a low intensity(1.5 Hz) or a verum SR-WBV training at a higher intensity(5 Hz). Systolic blood pressure(SBP), diastolic blood pressure(DBP), heart rate(HR) and selfreported muscle relaxation were assessed before and immediately after SR-WBV.RESULTS Two factorial analyses of variance(ANOVA) showed a significant interaction between pre- vs post-SR-WBVmeasurements and SR-WBV conditions for muscle relaxation in the neck and back [F(1,55) = 3.35, P = 0.048, η2 = 0.07]. Muscle relaxation in the neck and back increased in verum SR-WBV, but not in sham SR-WBV. No significant changes between pre- and post-training levels of SBD, DBD and HR were observed either in sham or verum SR-WBV conditions. With verum SR-WBV, improved muscle relaxation was the most significant in participants who reported the experience of back, neck or shoulder pain more than once a month(P < 0.05).CONCLUSION A single session of SR-WBV increased muscle relaxation in young healthy individuals, while cardiovascular load was low. An increase in musculoskeletal relaxation in the neck and back is a potential mediator of pain reduction in preventive worksite SR-WBV trials.Achim Elfering Christian Burger Volker Schade Lorenz Radlinger 2016World Journal of Orthopedics2016,7,11:4
19高使用性能粉末冶金零件的表面致密化显示文摘为保证机构的可靠性,历史上一直在用锻钢合金批量生产高转矩变速器零件,诸如变速器齿轮、高性能链轮、单向离合器座圈及滚珠轴承座圈。虽然用粉末冶金工艺生产的零件成本低廉,但常规粉末冶金钢的静态、疲劳及耐磨性能的局限性,使粉末冶金零件不能应用于上述领域。为解决这些缺欠,近年来,一直在研发用选择性表面致密化(SSD)改进粉末冶金钢性能的各种生产工艺。特别是,PMG集团开发出了一种拥有专利权的表面致密化工艺——DensiForm。利用这种工艺可使零件表面关键部分形成深度达1mm的完全致密化表面层,而零件心部仍然是多孔性的。这种结合与粉末冶金材料合金化的灵活性,使生产的烧结钢零件的使用性能可与在高应力下使用的锻钢性能相比拟。本文将介绍2个例子,即变速器中应用的表面致密化螺旋齿轮和直齿链条的驱动链轮。本文说明了螺旋齿轮和驱动链轮的生产工艺与显微组织,介绍了轿车变速器用螺旋齿轮的性能(其中包括在三轴总成的成对试验台架上得到的滚动接触疲劳的数据)和表面致密化链轮的材料性能与使用性能。Lorenz S Sigl Günter Rau Christian Dennert 2012粉末冶金技术2012,30,2:4
20表面致密化粉末冶金齿轮的性能显示文摘用压制、烧结及选择性横向辗压表面致密化制造了轿车变速器的粉末冶金螺旋齿轮。在生产的每一道工序中都根据显微组织、齿轮几何形状、表面粗糙度及DIN品质对齿轮的性能演变进行了监控。将粉末冶金齿轮的几何形状和现在变速器中使用的常规生产的锻钢齿轮(DIN品质7)进行了比较。表明,制造的粉末冶金齿轮的品质位于DIN品质8范围以内;而且,证明通过生产工序的改变可减小对中与齿廓的误差。虽然锻钢齿轮的对中与齿廓误差较小,但是粉末冶金齿轮的偏心率与节矩的误差和表面粗糙度较好。Lorenz S.Sigl Günter Rau Michael Krehl 韩凤麟(译) 2012粉末冶金技术2012,30,3:4
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