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Heterogeneous populations of neural stem cells contribute to myelin repair

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Neural regeneration research 2017年第4期12卷 509-517页

作者： rainer Akkermann Felix Beyer Patrick Küry Neuroregeneration Laboratory Department of NeurologyMedical FacultyHeinrich-Heine-University

As ingenious as nature＇s invention of myelin sheaths within the mammalian nervous system is, as fatal can be damage to this specialized lipid structure. Long-term loss of electrical insulation and of further supportive functions myelin provides to axons, as seen in demyelinating diseases such as multiple sclerosis （MS）, leads to neurodegeneration and results in progressive disabilities. Multiple lines of evidence have demon-strated the increasing inability of oligodendrocyte precursor cells （OPCs） to replace lost oligodendrocytes （OLs） in order to restore lost myelin. Much research has been dedicated to reveal potential reasons for this regeneration deficit but despite promising approaches no remyelination-promoting drugs have successfully been developed yet. In addition to OPCs neural stem cells of the adult central nervous system also hold a high potential to generate myelinating OLs. There are at least two neural stem cell niches in the brain, the subventricular zone lining the lateral ventricles and the subgranular zone of the dentate gyrus, and an additional source of neural stem cells has been located in the central canal of the spinal cord. While a substantial body of literature has described their neurogenic capacity, still little is known about the oligodendrogenic potential of these cells, even if some animal studies have provided proof of their contribution to remyelination. In this review, we summarize and discuss these studies, taking into account the different niches, the heterogeneity within and between stem cell niches and present current strategies of how to promote stem cell-mediated myelin repair.

关键词： heterogeneity oligodendrocyte neuroregeneration multiple sclerosis inhibitors intracellular proteinlocalization adult neural stem cell niche remyelination

restricting carbohydrates to fight head and neck cancer——is this realistic?

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Cancer Biology & Medicine 2014年第3期11卷 145-161页

作者： rainer J.Klement Department of radiotherapy and radiation Oncology Leopoldina Hospital

Head and neck cancers(HNCs) are aggressive tumors that typically demonstrate a high glycolytic rate, which results in resistance to cytotoxic therapy and poor prognosis. Due to their location these tumors specifically impair food intake and quality of life, so that prevention of weight loss through nutrition support becomes an important treatment goal. Dietary restriction of carbohydrates(CHOs) and their replacement with fat, mostly in form of a ketogenic diet(KD), have been suggested to accommodate for both the altered tumor cell metabolism and cancer-associated weight loss. In this review, I present three specific rationales for CHO restriction and nutritional ketosis as supportive treatment options for the HNC patient. These are(1) targeting the origin and specific aspects of tumor glycolysis;(2) protecting normal tissue from but sensitizing tumor tissue to radiation- and chemotherapy induced cell kill;(3) supporting body and muscle mass maintenance. While most of these benefits of CHO restriction apply to cancer in general, specific aspects of implementation are discussed in relation to HNC patients. While CHO restriction seems feasible in HNC patients the available evidence indicates that its role may extend beyond fighting malnutrition to fighting HNC itself.

关键词： Ketogenic diet(KD) head and neck neoplasms diet carbohydrate restricted(CHO restricted) nutritional support

Low-loss optical waveguides made with a high-loss material

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Light(Science & Applications) 2021年第1期10卷 12-18页

作者： Darius Urbonas rainer F.Mahrt Thilo Stoferle IBM research Europe—Zurich Saumerstrasse 48803 RuschlikonSwitzerland

For guiding light on a chip,it has been pivotal to use materials and process flows that allow low absorption and *** on subwavelength gratings,here,we show that it is possible to create broadband,multimode waveguides with very low propagation losses despite using a strongly absorbing *** perform rigorous coupled-wave analysis and finite-difference time-domain simulations of integrated waveguides that consist of pairs of integrated high-index-contrast *** showcase this concept,we demonstrate guiding of visible light in the wavelength range of 550-650 nm with losses down to 6dB/cm using silicon gratings that have a material absorption of 13,000 dB/cm at this wavelength and are fabricated with standard silicon photonics *** approach allows us to overcome traditional limits of the various established photonics technology platforms with respect to their suitable spectral range and,furthermore,to mitigate situations where absorbing materials,such as highly doped semiconductors,cannot be avoided because of the need for electrical driving,for example,for amplifiers,lasers and modulators.

关键词： waveguides absorbing absorption

3omorbidity and survival of patients selected for radica prostatectomy at an age of 75 years or older

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Asian Journal of Andrology 2013年第5期15卷 667-671页

作者： Michael Froehner rainer Koch Manfred P Wirth Departments of Urology University Hospital 'Carl Gustav Carus' Dresden University of Technology Dresden D-01307 Germany Department of Medical Statistics and Biometry University Hospital 'Carl Gustav Carus' Dresden University of Technology Dresden D-01307 Germany

radical prostatectomy in elderly patients is controversial. To identify very old candidates for radical prostatectomy with the highest probability of long-term survival, we studied 47 consecutive men who underwent radical prostatectomy between 1992 and 2005 at an age of 75 years or older. A heuristic approach was used to search for subgroups with particularly high long-term survival. Several two-sided comorbidity measures and combinations of these measures were investigated to find classifications best identifying healthy, long-living elderly candidates for radical prostatectomy. Four of the 25 two-sided comorbidity classifications or combinations reached the significance level with hazard ratios between 4.00 and 4.80. After 10 years, patients identified as healthy patients according to these comorbidity measurements had exhibited relative survival rates between 129% and 137% and overall survival rates between 86% and 95%, whereas those with comorbidities had exhibited relative survival rates of only 66%-84% and overall survival rates of 44%-58%. In conclusion, classifying comorbidity may identify a meaningful proportion of men selected for radical prostatectomy at an age of 75 years or older with an excellent long-term survival probability superseding that of the general population.

关键词： comorbidity old age overall survival prostate cancer radical prostatectomy relative survival

Molecular Dynamics Study of a Thermal Expansion Coefficient： Ti Bulk with an Elastic Minimum image Method

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Chinese Physics Letters 2006年第5期23卷 1068-1071页

作者： Yakup Hundur rainer Hippler Ziya B. Güven Department of Physics Istanbul Technical University Ayazaga Istanbul TR-34469 Turkey Institut für Physik Ernst-Moritz-Arndt-Universitat Greifswald DomstraBe 10a D-17487 Greifswald. Germany Electronic and Communication Engineering Cankaya University Balgat Ankara TR-06530 Turkey

Linear thermal expansion coefficient （TEC） of Ti bulk is investigated by means of molecular dynamics simulation. The elastic minimum image convention of periodic boundary conditions is introduced to allow the bulk to adjust its size according to the new fixed temperature. The TEC and the specific heat of Ti are compared to the available theoretical and experimental data.

关键词： TITANIUM

Effects of substrate surface treatments on hybrid manufacturing of AlSi7Mg using die casting and selective laser melting

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Journal of Materials Science & Technology 2023年第25期156卷 142-156页

作者： Haiyang Fan Ann Witvrouw Friedrich Wolf-Monheim rainer Souschek Shoufeng Yang Department of Mechanical Engineering and Flanders Make KU LeuvenCelestijnenlaan 300Bbox 2420HeverleeB-3001 LeuvenBelgium Ford research & Advanced Engineering Ford Research and Innovation Center AachenSüsterfeldstraße 20052072 AachenGermany Yantai research Institute Harbin Engineering University264000 YantaiChina

To balance the manufacturing cost and customizability of automotive parts,a hybrid manufacturing process combining die-casting and selective laser melting(SLM)is proposed:starting with a conventional cast substrate,SLM is utilized to add additional geometric elements on top of *** this hybrid process,the first priority is to prepare a substrate surface suitable for the subsequent SLM addition of the top-on *** this study,the original cast surface of AlSi7Mg was processed by sandblasting,wire electro-discharge machining,and laser remelting,***,additional AlSi7Mg components were built on both the original cast and treated surfaces through *** hybrid builds,these surfaces and resultant interfaces were examined by optical and scanning electron *** indicate that the defect-free metallurgical joint between the cast and additively added parts can be formed on all surfaces except for the one processed by electro-discharge *** observed epitaxial grain growth crossing the interface implies a strong connection between the cast and the SLMed *** these benefits,also mismatches in microstructure,residual stress level and element distribution between the two parts are *** a comprehensive assessment,laser remelting with no additional machining is recommended as the optimal surface treatment preceding SLM fabrication,because of its user-friendly operation,low cost,and high industrial feasibility.

关键词： Hybrid manufacturing Aluminium alloy Surface treatment Laser remelting Interface Automotive

Subwavelength thick ultrahigh-Q terahertz disc microresonators

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Photonics research 2020年第7期8卷 1183-1188页

作者： Dominik Walter Vogt Angus Harvey Jones Thomas Alan Haase rainer Leonhardt Department of Physics The University of AucklandAuckland 1010New Zealand The Dodd-Walls Centre for Photonic and Quantum Technologies Dunedin 9016New Zealand

Artificial structures that exhibit narrow resonance features are key to a myriad of scientific advances and *** particular,exploration of the terahertz(THz)spectrum—the final frontier of the electromagnetic spectrum—would greatly benefit from high-quality resonant *** we present a new paradigm of terahertz silicon disc microresonators with subwavelength *** results utilizing continuouswave THz spectroscopy establish quality factors in excess of 120,000 at 0.6 *** of the disc thickness to a fraction of the wavelength reduces the losses from the silicon substrate and paves the way to unparalleled possibilities for light–matter interaction in the THz frequency range.

关键词： spectrum utilizing frontier

Could a phase model help to improve translational animal research?

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Animal Models and Experimental Medicine 2022年第6期5卷 550-556页

作者： Benjamin Mayer Jan Tuckermann rainer Muche Institute of Epidemiology and Medical Biometry Ulm UniversityUlmGermany Institute of Comparative Molecular Endocrinology Ulm UniversityUlmGermany

Background:Animal models are widely applied in medical research for different *** particular,results from translational experiments may be used for subsequent clinical ***,transferability of these findings to the human organism is *** other factors,this may be traced back to a lack of clear differentiation of the evidence(explorative ***)provided by such experimental *** general,inferential statistics(i.e.p values)should not be interpreted in as confirmatory unless crucial methodological requirements are ***:Therefore,we propose a phase model which reflects the well-established process of clinical research,and we discuss its potential to improve decision making in translational *** model aims to clarify the reliability of results derived from animal ***:The phase model proposes subdividing translational,pre-clinical research into pilot,exploration,and confirmation *** for which there is no valid estimation of the expected effect size are designated as pilot *** on these data,experiments in subsequent phases may be planned using both appropriate design and statistical ***:Separating the entire process of translational animal research into three phases could contribute to improved transparency of the evidence derived from such experiments.

关键词： confirmatory trials hypothesis testing results interpretation transferability

General regulatory Patterns of Plant Mineral Nutrient Depletion as revealed by serat Quadruple Mutants Disturbed in Cysteine Synthesis

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Molecular Plant 2010年第2期3卷 438-466页

作者： Mutsumi Watanabe Hans-Michael Hubberten Kazuki Saito rainer Hoefgen Graduate School of Pharmaceutical Sciences Chiba University 1-33 Yayoi-cho Inage-ku Chiba 263-8522 Japan Max-Planck-lnstitut fuer Molekulare Pflanzenphysiologie Wissenschaftspark Golm Am Muehlenberg 1 14476 Potsdam-Golm rIKEN Plant Science Center Tsurumi-ku Yokohama 230-0045 Japan

Sulfate is an essential macronutrient for plants. Plants have developed strategies to cope with sulfate deficiency, and other nutrient ion limitations. However, the regulation of these adaptive responses and the coordinating signals that underlie them are still poorly characterized. O-acetylserine （OAS） is a marker metabolite of sulfate starvation and has been speculated to have a signaling function. OAS is synthesized by the enzyme serine acetyltransferase （SErAT）, which is encoded by five distinct genes in Arabidopsis. We investigated quadruple knockout mutants of SErAT that retained only one functional isoform. These mutants displayed symptoms of sulfate starvation. Furthermore, some of them displayed phenotypes typical of prolonged sulfate starvation, in particular, developmental programs associated with senescence or stress responses. Thus, we compared metabolite and transcriptome data from these mutants with N-, P-, K-, and S-depleted plants. This revealed many similarities with general nutrient-depletion-induced senescence （NuDIS）, in- dicating the recruitment of existing regulatory programs for nutrient-starvation responses. Several candidate genes that could be involved in these processes were identified, including transcription factors and other regulatory proteins, as well as the functional categories of their target genes. These results outline components of the regulatory network controlling plant development under sulfate stress, forming a basis for further investigations to elucidate the complete network. In turn, this will advance our broader understanding of plant responses to a range of other nutrient stresses.

关键词： Abiotic/environmental stress ion/metabolite sensing senescence functional genomics Arabidopsis sulfur.