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Decreasing nutrient concentrations in soils and trees with increasing elevation across a treelineecotone in Rolwaling Himal, Nepal

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Journal of Mountain Science 2017年第5期14卷 843-858页

作者： Simon DROLLINGER michael muller Timo KOBL Niels SCHWAB Jurgen BOHNER Udo SCHICKHOFF Thomas SCHOLTEN Geoecology Department of Geography and Regional Research University of Vienna Vienna Austria Soil Science and Geomorphology Department of Geosciences Uniuersity of Tubingen Tubingen Germany CEN Center for Earth System Research and Sustainability Institute of Geography University of Hamburg Hamburg Germany

At a global scale, tree growth in alpine treeline ecotones is limited by low temperatures. At a local scale, however, tree growth at its upper limit depends on multiple interactions of influencing factors and mechanisms. The aim of our research was to understand local scale effects of soil properties and nutrient cycling on tree growth limitation, and their interactions with other abiotic and biotic factors in a near-natural Himalayan treeline ecotone. Soil samples of different soil horizons, litter, decomposition layers, and foliage samples of standing biomass were collected in four altitudinal zones along three slopes, and were analysed for exchangeable cations and nutrient concentrations, respectively. Additionally, soil and air temperature, soil moisture, precipitation, and tree physiognomy patterns were evaluated. Both soil nutrients and foliar macronutrient concentrations of nitrogen(N), magnesium(Mg), potassium(K), and foliar phosphorus(P) decrease significantly with elevation. Foliar manganese(Mn) concentrations, bycontrast, are extraordinarily high at high elevation sites. Potential constraining factors on tree growth were identified using multivariate statistical approaches. We propose that tree growth, treeline position and vegetation composition are affected by nutrient limitation, which in turn, is governed by low soil temperatures and influenced by soil moisture conditions.

关键词： Foliar nutrients Himalaya Nitrogen Nutrient cycling Podzol Treeline

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Implications of tree species–environment relationships for the responsiveness of Himalayan krummholz treelines to climate change

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Journal of Mountain Science 2017年第3期14卷 453-473页

作者： Niels SCHWAB Udo SCHICKHOFF Birgit BURZLE michael muller Jurgen BOHNER Ram Prasad CHAUDHARY Thomas SCHOLTEN Jens OLDELAND CEN Center for Earth System Research and Sustainability Institute of GeographyUniversity of HamburgBundesstrafle 5520146 HamburgGermany Department of Geosciences Chair of Soil Science and CeomorphologyUniversity of TübingenGermany Research Centre for Applied Science and Technology&Central Department of Botany Tribhuvan UniversityNepal Biocentre Klein Flottbek University of HamburgOhnhorststr.1822609 HamburgGermany

Climate warming is expected to advance treelines to higher elevations. However, empirical studies in diverse mountain ranges give evidence of both advancing alpine treelines as well as rather insignificant responses. In this context, we aim at investigating the sensitivity and responsiveness of the near-natural treeline ecotone in Rolwaling Himal, Nepal, to climate warming. We analysed population densities of tree species along the treeline ecotone from closed forest stands via the krummholz belt to alpine dwarf shrub heaths （3700-4200 m） at 50 plots in 2013 and 2014. We quantified species - environment relationships, i.e. the change of environmental conditions （e.g., nutrient and thermal deficits, plant interactions） across the ecotone by means of redundancy analyses, variation partitioning and distance-based Moran＇s eigenvector maps. In particular, we focus on explaining the high competitiveness of Rhododendron campanulatum forming a dense krummholz belt and on the implications for the responsiveness of Himalayan krummholz treelines to climate change. Results indicate that treeline trees in the ecotone show species-specific responses to the influence of environmental parameters, and that juvenile and adult tree responses are modulated by environmental constraints in differing intensity. Moreover, the species - environment relationships suggest that the investigated krummholz belt will largely prevent the upward migration of other tree constrain the future response species and thus of Himalayan krummholz treelines to climate warming.

关键词： Himalaya Nepal Population structure Rhododendron campanulatum Spatial patterns Species-environment relationships Stand density Variation partitioning

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光学纯(4S,5R)-4-甲基-5-羟基-3-羰基己酸特丁酯的化学酶促合成

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有机化学 2002年第12期22卷 1009-1012页

作者：吉爱国 michael Mueller michael Wolberg Werner Hummel Christian Wandreyb 山东大学药学院济南250012 德国于利希研究中心生物技术研究所于利希52425 德国于利希研究中心杜塞尔多夫大学酶技术研究所于利希52426

采用化学方法合成了 4 甲基 3,5 二羰基己酸特丁酯 .以Lactobacillusbrevis醇脱氢酶为生物催化剂 ,选择性地将 4 甲基 3,5 二羰基己酸特丁酯还原为 (4S ,5R) 4 甲基 5 羟基 3 羰基己酸特丁酯 (99.2 %ee,syn∶anti=97∶3) .

关键词：光学纯 (4S,5R)-4-甲基-5-羟基-3-羰基己酸特丁酯化学酶促合成 Lactobacillus brevis醇脱氢酶药物中间体

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实现可持续发展的工业园工业园区不再依赖外部电网供电

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流程工业 2012年第19期 22-24页

作者： michael muller

InfraservH6chst公司作为工业园的现场服务公司，在为大约90家企业服务的过程中不再依赖外部电网供电，而是利用自主研发的新型发电设备实现自主供电，这成为了传统工业园区发展的一个重要里程碑。

关键词：工业园区电网供电可持续发展服务公司 st公司发电设备自主研发

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离心压缩机涡壳的设计与发展

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通用机械 2008年第9期6卷 69-74页

作者：许承 michael muller 英格索兰上海200051

详细的气流模拟有助于更好地理解涡壳气流机制,从而为涡壳的成功设计以达到其性能指标提供设计指导。引用了黏性耐威尔-斯托克斯方程式用来模拟无叶片扩压器和涡壳内的气流,并详细研究了不同涡舌几何形状的细部气流的形成。把计算数据... 详细信息

详细的气流模拟有助于更好地理解涡壳气流机制,从而为涡壳的成功设计以达到其性能指标提供设计指导。引用了黏性耐威尔-斯托克斯方程式用来模拟无叶片扩压器和涡壳内的气流,并详细研究了不同涡舌几何形状的细部气流的形成。把计算数据与试验数据进行比较时,发现具有很好的一致性。也为涡壳设计的进一步研究指明了方向。

关键词：离心压缩机涡壳涡舌结构

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Like a G6-nal:transcriptional control of G-protein coupled receptors during oligodendroglial development

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Neural Regeneration Research 2025年第7期20卷 2001-2002页

作者： Tim Aberle michael Wegner Institut für Biochemie Friedrich-Alexander-Universität Erlangen-NürnbergErlangenGermany

Multilayered control of myelination:Quick,saltatory conduction of action potentials along nerve fibers requires the electrical insulation of axons by myelinating *** the central nervous system,this role is taken up by *** are marked by the expression of the lineage determinants Sox10 and Olig2 and arise from oligodendrocyte precursor cells(OPCs)during embryonal *** the majority of OPCs differentiate into mature oligodendrocytes when nearby axonal segments require myelination,a small subpopulation of OPCs persist as a progenitor ***,the timing of myelination and maintenance of the OPC pool both need to be precisely *** transcription factors either positively or negatively affect oligodendrocyte differentiation and maintenance of the OPC pool as components of a complex gene regulatory network(reviewed in Sock and Wegner,2021).Network activity is additionally influenced by extracellular signaling molecules that bind to receptors on the oligodendroglial cell surface and activate intracellular signaling *** the receptors are linked to the network is poorly understood so far,but pivotal to understanding the overall regulation of central nervous system(CNS)myelination in response to environmental *** insights were recently gained for Gpr37(Schmidt et al.,2024),a G-protein coupled receptor(GPCR)with known relevance in differentiating oligodendrocytes(Yang et al,2016).

关键词： gained insulation conduction

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Emerging structures and dynamic mechanisms ofγ-secretase for Alzheimer’s disease

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Neural Regeneration Research 2025年第1期20卷 174-180页

作者： Yinglong Miao michael S.Wolfe Computational Medicine Program and Department of Pharmacology University of North Carolina–Chapel HillChapel HillNCUSA Department of Medicinal Chemistry University of KansasLawrenceKSUSA

γ-Secretase,called“the proteasome of the membrane,”is a membrane-embedded protease complex that cleaves 150+peptide substrates with central roles in biology and medicine,including amyloid precursor protein and the Notch family of cell-surface *** inγ-secretase and amyloid precursor protein lead to early-onset familial Alzheimer’s disease.γ-Secretase has thus served as a critical drug target for treating familial Alzheimer’s disease and the more common late-onset Alzheimer’s disease as ***,critical gaps remain in understanding the mechanisms of processive proteolysis of substrates,the effects of familial Alzheimer’s disease mutations,and allosteric modulation of substrate cleavage byγ-*** this review,we focus on recent studies of structural dynamic mechanisms ofγ-*** mechanisms,including the“Fit-Stay-Trim,”“Sliding-Unwinding,”and“Tilting-Unwinding,”have been proposed for substrate proteolysis of amyloid precursor protein byγ-secretase based on all-atom molecular dynamics *** an incorrect registry of the Notch1 substrate was identified in the cryo-electron microscopy structure of Notch1-boundγ-secretase,molecular dynamics simulations on a resolved model of Notch1-boundγ-secretase that was reconstructed using the amyloid precursor protein-boundγ-secretase as a template successfully capturedγ-secretase activation for proper cleavages of both wildtype and mutant Notch,being consistent with biochemical experimental *** approach could be potentially applied to decipher the processing mechanisms of various substrates byγ-*** addition,controversy over the effects of familial Alzheimer’s disease mutations,particularly the issue of whether they stabilize or destabilizeγ-secretase-substrate complexes,is ***,an outlook is provided for future studies ofγ-secretase,including pathways of substrate binding and product release,effects of modulators on familial Alzheimer’s disease mutations

关键词： Alzheimer’s disease amyloid precursor protein cryo-EM structures drug design intramembrane proteolysis molecular dynamics Notch

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NECAB family of neuronal calcium-binding proteins in health and disease

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Neural Regeneration Research 2025年第5期20卷 1236-1243页

作者： Diones Bueno michael K.E.Schafer Sudena Wang michael J.Schmeisser Axel Methner Institute for Molecular Medicine University Medical Center of the Johannes Gutenberg-UniversityMainzGermany Department of Anesthesiology University Medical Center of the Johannes Gutenberg-UniversityMainzGermany Institute of Anatomy University Medical Center of the Johannes Gutenberg-UniversityMainzGermany

The N-terminal EF-hand calcium-binding proteins 1–3(NECAB1–3) constitute a family of predominantly neuronal proteins characterized by the presence of at least one EF-hand calcium-binding domain and a functionally less well characterized C-terminal antibiotic biosynthesis monooxygenase domain. All three family members were initially discovered due to their interactions with other proteins. NECAB1 associates with synaptotagmin-1, a critical neuronal protein involved in membrane trafficking and synaptic vesicle exocytosis. NECAB2 interacts with predominantly striatal G-protein-coupled receptors, while NECAB3 partners with amyloid-β A4 precursor protein-binding family A members 2 and 3, key regulators of amyloid-β production. This demonstrates the capacity of the family for interactions with various classes of proteins. NECAB proteins exhibit distinct subcellular localizations: NECAB1 is found in the nucleus and cytosol, NECAB2 resides in endosomes and the plasma membrane, and NECAB3 is present in the endoplasmic reticulum and Golgi apparatus. The antibiotic biosynthesis monooxygenase domain, an evolutionarily ancient component, is akin to atypical heme oxygenases in prokaryotes but is not wellcharacterized in vertebrates. Prokaryotic antibiotic biosynthesis monooxygenase domains typically form dimers, suggesting that calcium-mediated conformational changes in NECAB proteins may induce antibiotic biosynthesis monooxygenase domain dimerization, potentially activating some enzymatic properties. However, the substrate for this enzymatic activity remains uncertain. Alternatively, calcium-mediated conformational changes might influence protein interactions or the subcellular localization of NECAB proteins by controlling the availability of protein–protein interaction domains situated between the EF hands and the antibiotic biosynthesis monooxygenase domain. This review summarizes what is known about genomic organization, tissue expression, intracellular localization, interac

关键词： calcium EF hand mitochondria nervous system signal transduction

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胰腺癌细胞起源和演进的新实验证据

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中华肝胆外科杂志 2005年第5期11卷 320-323页

作者：郭俊超赵玉沛 Dale E.Bockman 廖泉 michael W.muller Helmut Friess 中国医学科学院中国协和医科大学北京协和医院基本外科北京市100730 Department of General Surgery University of HeidelbergGermany

目的大量研究证实导管样复合体就是胰腺癌的前体病变,因此,本研究旨在探索植入致癌剂后胰腺癌前体病变的产生和发展。方法采用手术方法将致癌剂DMBA植入SD大鼠胰腺,从第1天开始,在不同的时间点获取胰腺进行组织学研究,同时,分别以糜蛋... 详细信息

目的大量研究证实导管样复合体就是胰腺癌的前体病变,因此,本研究旨在探索植入致癌剂后胰腺癌前体病变的产生和发展。方法采用手术方法将致癌剂DMBA植入SD大鼠胰腺,从第1天开始,在不同的时间点获取胰腺进行组织学研究,同时,分别以糜蛋白酶和细胞角蛋白作为胰腺腺泡细胞和导管细胞的标记物,通过免疫组化方法进行定位。结果在包埋致癌剂第2天就可以观察到正常胰腺小叶向导管复合体移型的现象,第4天出现典型的导管复合体,同时,胰岛也参与了这一过程。小叶中的非导管细胞迅速转分化为导管细胞的特征。在1个月时观察到导管腺癌的形成。与对照组相比,腺泡-导管转分化过程在DMBA包埋组持续存在。结论胰腺癌前体病变(导管复合体)除了由已经存在于小叶内的导管细胞组成外,主要通过腺泡细胞转分化形成,同时,胰岛细胞在某种程度上也参与了导管复合体的形成。因此,胰腺腺泡细胞、胰岛细胞和导管细胞共同参与了胰腺导管腺癌前体细胞的起源,转分化可以不需要细胞分裂迅速发生,而恶性转化需要较长的时间。

关键词：胰腺癌细胞起源胰腺腺泡细胞导管细胞证据实验演进免疫组化方法 DMBA 导管腺癌胰岛细胞复合体用手术方法组织学研究细胞角蛋白细胞转分化致癌剂 SD大鼠糜蛋白酶正常胰腺持续存在分化过程细胞组成前体细胞

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Small extracellular vesicles derived from cerebral endothelial cells with elevated microRNA 27a promote ischemic stroke recovery

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Neural Regeneration Research 2025年第1期20卷 224-233页

作者： Yi Zhang Zhongwu Liu michael Chopp michael Millman Yanfeng Li Pasquale Cepparulo Amy Kemper Chao Li Li Zhang Zheng Gang Zhang Department of Neurology Henry Ford HospitalDetroitMIUSA Department of Physics Oakland UniversityRochesterMIUSA Department of Pathology Henry Ford HospitalDetroitMIUSA Division of Pharmacology Department of NeuroscienceReproductive and Dentistry SciencesSchool of MedicineUniversity of Naples“Federico Ⅱ”NaplesItaly

Axonal remodeling is a critical aspect of ischemic brain repair processes and contributes to spontaneous functional *** previous in vitro study demonstrated that exosomes/small extracellular vesicles(sEVs)isolated from cerebral endothelial cells(CEC-sEVs)of ischemic brain promote axonal growth of embryonic cortical neurons and that microRNA 27a(miR-27a)is an elevated miRNA in ischemic *** the present study,we investigated whether normal CEC-sEVs engineered to enrich their levels of miR-27a(27a-sEVs)further enhance axonal growth and improve neurological outcomes after ischemic stroke when compared with treatment with non-engineered CEC-sEVs.27a-sEVs were isolated from the conditioned medium of healthy mouse CECs transfected with a lentiviral miR-27a expression *** EVs isolated from CECs transfected with a scramble vector(Scra-sEVs)were used as a *** male mice were subjected to permanent middle cerebral artery occlusion and then were randomly treated with 27a-sEVs or *** array of behavior assays was used to measure neurological *** with treatment of ischemic stroke with Scra-sEVs,treatment with 27a-sEVs significantly augmented axons and spines in the peri-infarct zone and in the corticospinal tract of the spinal grey matter of the denervated side,and significantly improved neurological *** vitro studies demonstrated that CEC-sEVs carrying reduced miR-27a abolished 27a-sEV-augmented axonal *** analysis revealed that 27a-sEVs systemically administered preferentially localized to the pre-synaptic active zone,while quantitative reverse transcription-polymerase chain reaction and Western Blot analysis showed elevated miR-27a,and reduced axonal inhibitory proteins Semaphorin 6A and Ras Homolog Family Member A in the peri-infarct *** of the Clathrin-dependent endocytosis pathway substantially reduced neuronal internalization of *** data provide evidence that 27a-sEVs have

关键词： axonal remodeling cerebral endothelial cells exosomes miR-27a mitochondria Semaphorin 6A small extracellular vesicles stroke

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