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Frontiers of Mechanical Engineering 2023年第4期18卷 183-193页

作者： Alexander SChMIDT felix jensch.sebastian h.rtel Chair of hybrid Manufacturing Brandenburg University of TechnologyCottbus 03046Germany

Many processes may be used for manufacturing functionally graded *** them,additive manufacturing seems to be predestined due to near-net shape manufacturing of complex geometries combined with the possibility of applying different materials in one *** adjusting the powder composition of the starting material layer by layer,a macroscopic and step-like gradient can be *** further improve the step-like gradient,an enhancement of the in-situ mixing degree,which is limited according to the state of the art,is *** this paper,a novel technique for an enhancement of the in-situ material mixing degree in the melt pool by applying laser remelting(LR)is *** effect of layer-wise LR on the formation of the interface was investigated using pure copper and low-alloy steel in a laser powder bed fusion *** cross-sectional selective electron microscopic analyses were carried *** applying LR,the mixing degree was enhanced,and the reaction zone thickness between the materials was ***,an additional copper and iron-based phase was formed in the interface,resulting in a smoother gradient of the chemical composition than the case without *** Marangoni convection flow and thermal diffusion are the driving forces for the observed effect.

关键词： multi-material additive manufacturing(MMAM) functionally graded materials(FGMs) laser powder bed fusion(L-PBF) laser remelting(LR) pure copper

The German Energiewende and its roll-out of renewableenergies： An economic perspective

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Frontiers in Energy 2017年第2期11卷 126-134页

作者： sebastian KREUZ felix MUSGENS Faculty of Mechanical Engineering Electrical and Energy SystemsBrandenburg University of Technology 03046 Cottbus Germany

This paper gives a short overview of the German Energiewende, i.e. the transition of a large and mostly thermal electricity system towards electricity generation from renewable energy source. It discusses both, the motivation of the transitions as future goals and current status. Furthermore, it gives an in-depth view into the changes in economic costs for society as well as electricity price effects, especially for average private households and industrial consumers. It also discusses the benefits of the promotion of renewable energies in Germany.

关键词： electricity system renewable energy cost-benefit analysis

Real-time beam shaping without additional optical elements

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Light(Science & Applications) 2018年第1期7卷 881-891页

作者： felix Fries Markus Fröbel Pen Yiao Ang Simone Lenk sebastian Reineke Dresden Integrated Center for Applied Physics and Photonic Materials(IAPP) Technische Universität DresdenNöthnitzer Straße 61Dresden 01187Germany

Providing artificial light and enhancing the quality of the respective light sources is of continued interest in the fields of solid state,condensed matter,and semiconductor *** research has been carried out to increase the luminous efficiency,lifetime and colour stability of such ***,the emission characteristics of a given light source do not necessarily comply with today’s often sophisticated ***,beam shaping addresses the transformation of a given light distribution into a customized *** is typically achieved by secondary optical elements often sporting elaborate designs,where the actual light source takes up only a small fraction of the system’s *** designs limit the final light source to a single permanent operation mode,which can only be overcome by employing mechanically adjustable optical *** we show that organic light-emitting diodes(OLEDs)can enable real-time regulation of a beam shape without relying on secondary optical elements and without using any mechanical *** a red light-emitting two-unit OLED architecture,we demonstrate the ability to continuously tune between strongly forward and strongly sideward emission,where the device efficiency is maintained at an application-relevant level ranging between 6 and 8%of external quantum efficiency for any chosen *** combination with additional optical elements,customizable and tuneable systems are possible,whereby the tuning stems from the light source itself rather than from the use of secondary optics.

关键词： tuning beam elements

Prevalence of Bicuspid Aortic Valve in Turner Syndrome Patients Receiving Cardiac MRI and CT: A Meta-Analysis

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Congenital heart Disease 2022年第2期17卷 129-140页

作者： Pengzhu Li Martina Bacova Robert Dalla-Pozza Nikolaus Alexander haas felix sebastian Oberhoffer Department of Pediatric Cardiology and Intensive Care Medical Hospital of the University of MunichLudwig Maximilians University MunichMunichGermany

Turner syndrome(TS)is a rare disorder affecting 25–50 in 100000 female *** aortic valve(BAV)is assumed to be the most common congenital heart defect(ChD)in *** literature,reported BAV prevalence in TS ranges between 14%and 34%.The specific BAV prevalence in TS is still *** aim of this study was to give a more precise estimation of BAV prevalence in TS by conducting a meta-analysis of TS-studies,which detected BAV by either cardiac magnetic resonance imaging(MRI)or cardiac computed tomography(CT).We searched PubMed,Cochrane Library,and Web of Science databases to collect observational studies including the prevalence of BAV identified by cardiac MRI or cardiac CT in TS patients up to June 4th,*** screening for inclusion,data extraction,and quality assessment by two independent reviewers,the meta-analysis was performed with R 4.1.1 *** are shown as proportion and weighted mean difference with 95%confidence intervals(95%CI).In total,11 studies involving 1177 patients were *** data showed that the prevalence of BAV in TS patients was 23.7%(95%CI:21.3%to 26.1%).No high heterogeneity was found between the included *** current meta-analysis reveals that BAVcan be detected in 23.7%of TS patients receiving cardiac MRI or cardiac ***,BAV can be considered as the most common ChD in *** to TTE,cardiac MRI and cardiac CT might represent superior imaging modalities in BAV assessment of adult TS patients.

关键词： Turner syndrome bicuspid aortic valve magnetic resonance imaging(MRI) tomography X-ray computed(CT)

Alternative models of cancer stem cells: The stemness phenotype model, 10 years later

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World Journal of Stem Cells 2021年第7期13卷 934-943页

作者： Vivek Kaushik Yogesh Kulkarni Kumar felix Neelam Azad Anand Krishnan V Iyer Juan sebastian Yakisich School of Pharmacy Department of Pharmaceutical SciencesHampton UniversityHamptonVA 23668United States

The classical cancer stem cell(CSCs)theory proposed the existence of a rare but constant subpopulation of *** this model cancer cells are organized hierarchically and are responsible for tumor resistance and tumor ***,eliminating CSCs will eventually lead to cure of *** simplistic model has been challenged by experimental *** 2010 we proposed a novel and controversial alternative model of CSC biology(the Stemness Phenotype Model,SPM).The SPM proposed a non-hierarchical model of cancer biology in which there is no specific subpopulation of CSCs in ***,cancer cells are highly plastic in term of stemness and CSCs and non-CSCs can interconvert into each other depending on the *** model predicts the existence of cancer cells ranging from a pure CSC phenotype to pure non-CSC phenotype and that survival of a single cell can originate a new *** the past 10 years,a plethora of experimental evidence in a variety of cancer types has shown that cancer cells are indeed extremely plastic and able to interconvert into cells with different stemness *** this review we will(1)briefly describe the cumulative evidence from our laboratory and others supporting the SPM;(2)the implications of the SPM in translational oncology;and(3)discuss potential strategies to develop more effective therapeutic regimens for cancer treatment.

关键词： Cancer Stem cells Stemness Plasticity Chemotherapy Interconversion

Ionic effects on the transport characteristics of nanowire-based FETs in a liquid environment

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Nano Research 2014年第3期7卷 380-389页

作者： Daijiro Nozaki Jens Kunstmann felix Zorgiebel sebastian Pregl Larysa Baraban Walter M. Weber Thomas Mikolajick Gianaurelio Cuniberti Institute for Materials Science and Max Bergmann Center of Biomaterials TU Dresden 01062 Dresden Germany Department of Chemistry Columbia University 3000 Broadeway New York NY 10027 USA NaMlab gGmbh N6thinger Str. 64 01187 Dresden Center forAdvancing Electronics Dresden (cfAED) TU Dresden 01062 Dresden Germany Dresden Center for Computational Materials Science (DCCMS) TU Dresden 01062 Dresden Germany

For the development of ultra-sensitive electrical bio/chemical sensors based on nanowire field effect transistors （FETs）, the influence of the ions in the solution on the electron transport has to be understood. For this purpose we establish a simulation platform for nanowire FETs in the liquid environment by implementing the modified Poisson-Boltzmann model into Landauer transport theory. We investigate the changes of the electric potential and the transport characteristics due to the ions. The reduction of sensitivity of the sensors due to the screening effect from the electrolyte could be successfully reproduced. We also fabricated silicon nanowire Schottky-barrier FETs and our model could capture the observed reduction of the current with increasing ionic concentration. This shows that our simulation platform can be used to interpret ongoing experiments, to design nanowire FETs, and it also gives insight into controversial issues such as whether ions in the buffer solution affect the transport characteristics or not.

关键词： nanowire field effecttransistors (FETs) biosensors silicon nanowires Poisson-Boltzmann theory Landauer model

Schottky barrier-based silicon nanowire ph sensor with live sensitivity control

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Nano Research 2014年第2期7卷 263-271页

作者： felix M. Zorgiebel sebastian Pregl Lotta Romhildtt Jorg Opitz W. Weber T. Mikolajick Larysa Baraban Gianaurelio Cuniberti Institute for Materials Science and Max Bergmann Center ofBiomaterials TU Dresden 01062 Dresden Germany NaMLab Gmbh 01187 Dresden Germany Fraunhofer Institute IZFP Dresden 01109 Dresden Germany Institute for Semiconductors and Microsystems Technology TU Dresden 01187 Dresden Germany Dresden Germany Center forAdvancing Electronics Dresden TU Dresden 01062 Dresden Germany

We demonstrate a ph sensor based on ultrasensitive nanosize Schottky junctions formed within bottom-up grown dopant-flee arrays of assembled silicon nanowires. A new measurement concept relying on a continuous gate sweep is presented, which allows the straightforward determination of the point of maximum sensitivity of the device and allows sensing experiments to be performed in the optimum regime. Integration of devices into a portable fluidic system and an electrode isolation strategy affords a stable environment and enables long time robust FET sensing measurements in a liquid environment to be carried out. Investigations of the physical and chemical sensitivity of our devices at different ph values and a comparison with theoretical limits are also discussed. We believe that such a combination of nanofabrication and engineering advances makes this Schottky barrier-powered silicon nanowire lab-on-a-chip platform suitable for efficient biodetection and even for more complex biochemical analysis.

关键词： silicon nanowires field effect transistor sub-threshold regime nanosensors ph sensor bottom-up fabrication maximum sensitivity ofsensor

Trained laser-patterned carbon as high-performance mechanical sensors

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npj Flexible Electronics 2022年第1期6卷 36-44页

作者： Marco hepp huize Wang Katharina Derr Simon Delacroix sebastian Ronneberger felix F.Loeffler Benjamin Butz Volker Strauss Micro‐and Nanoanalytics Group University of SiegenPaul‐Bonatz Str.9–11Siegen 57076Germany Max Planck Institut für Kolloid-und Grenzflächenforschung Am Mühlenberg 114476 PotsdamGermany LPICM CNRS UMR 7647Ecole polytechniqueInstitut Polytechnique de ParisPalaiseau 91128France

We describe the mechanical properties of turbostratically graphitized carbon films obtained by carbon laser-patterning(CLaP)and their application as bending or mechanical pressure *** conductive carbonized films were imprinted on a flexible polyethylene terephthalate(PET)substrate by laser-induced *** initial gentle bending,***,these spongelike porous films show a quantitative and reversible change in resistance upon bending or application of pressure in normal loading *** response values ofΔR/R0=388%upon positive bending(tensile stress)and−22.9%upon negative bending(compression)are implicit for their high sensitivity towards mechanical *** mechanical loading in a range between 0 and 500 kPa causes a response betweenΔR/R_(0)=0 and−15%.The reversible increase or decrease in resistance is attributed to compression or tension of the turbostratically graphitized domains,*** mechanism is supported by a detailed microstructural and chemical high-resolution transmission electron microscopic analysis of the cross-section of the laserpatterned carbon.

关键词： resistance bending carbon

Case Studies on Acupuncture Principles in headaches

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Chinese Medicine and Culture 2021年第2期4卷 93-98页

作者： Saroj Kumar Pradhan Andreas Rudolf Gantenbein Yi-Ming Li sebastian Frese Susanne Lehmann felix Angst Department of Traditional Chinese Medicine Zurzach Care/TCM-Klinik Ming DaoBad Zurzach 5330Switzerland Department of Research Swiss TCM AcademyBad ZurzachSwitzerland in Collaboration with Department of ResearchNanjing University of Chinese MedicineNanjing 210029JiangsuChina Department of Neurology and Neurorehabilitation Zurzach CareBad Zurzach 5330Switzerland Department of Prevention Zurzach CareBad Zurzach 5330Switzerland Department of Research Zurzach CareBad Zurzach 5330Switzerland

Objective:This observational cohort pilot study aimed to evaluate the effects of the acupuncture methods,Jiu Cang Zhen(JCZ)and huang Guan(hG),on changes in headache intensity in an inpatient,multimodal Zurzach headache Programme(ZhP).Methods:Study participants consisted of patients diagnosed with chronic headache disorder(headache ds,30 days per month)or daily persistent *** patients received conventional therapies with active and passive *** patient group was treated with JCZ and hG acupuncture methods,receiving a total of six to eight acupuncture sessions of 50 to 60 minutes each,during a 3–4-week multimodal ZhP at the RehaClinic Bad *** intensity was quantified using a Numerical Rating Scale(NRS)before and after each acupuncture therapy ***:Ten patients were recruited,six women and four men,with a mean age of 41.7(standard deviation,[SD]=13.9).A reduction in headache intensity was reported by all patients in each of the *** average NRS for pain was 4.21(SD=1.44)before acupuncture and 1.24(SD=0.93)after acupuncture(means first by number of sessions,then per n=10 patients).This resulted in a mean difference of 2.97(SD=1.04),corresponding to a standardized response mean of 2.85(95%confidence interval:2.11–3.60,one-tailed Phere was a large ***:This pilot study shows that JCZ and hG are suitable acupuncture methods for reducing headache intensity in the treatment of headaches.A comparison with the conventional classical acupuncture methods from the acupuncture textbook for traditional Chinese medicine students in China,exploration with a larger patient group,and prolonged monitoring of pain behavior could be foci of follow-up investigations.

关键词： Acupuncture headache migraine medication-overuse headache neurology

Increased liver stiffness in alcoholic liver disease:Differentiating fibrosis from steatohepatitis

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World Journal of Gastroenterology 2010年第8期16卷 966-972页

作者： sebastian Mueller Gunda Millonig Lucie Sarovska Stefanie Friedrich Frank M Reimann Maria Pritsch Silke Eisele felix Stickel Thomas Longerich Peter Schirmacher helmut Karl Seitz Department of Medicine and Center for Alcohol Research Salem Medical Center University of Heidelberg Institute of Medical Biometry and Informatics University of Heidelberg Institute of Clinical Pharmacology University of Bern Department of Pa-thology University of Heidelberg

AIM:To test if inflammation also interferes with liver stiffness (LS) assessment in alcoholic liver disease (ALD) and to provide a clinical algorithm for reliable fibrosis assessment in ALD by FibroScan (FS).METhODS:We first performed sequential LS analysis before and after normalization of serum transaminases in a learning cohort of 50 patients with ALD admitted for alcohol detoxification. LS decreased in almost all patients within a mean observation interval of 5.3 d. Six patients (12%) would have been misdiagnosed with F3and F4 fibrosis but LS decreased below critical cut-off values of 8 and 12.5 kPa after normalization of trans-aminases. RESULTS:Of the serum transaminases,the decrease in LS correlated best with the decrease in glutamic oxaloacetic transaminase (GOT). No significant chang-es in LS were observed below GOT levels of 100 U/L. After establishing the association between LS and GOT levels,we applied the rule of GOT hort of 101 patients with histologically confi rmed ALD. By ex-cluding those patients with GOT > 100 U/L at the time of LS assessment from this cohort,the area under the receiver operating characteristic (AUROC) for cirrhosis detection by FS improved from 0.921 to 0.945 while specificity increased from 80% to 90% at a sensitivity of 96%. A similar AUROC could be obtained for lower F3 fibrosis stage if LS measurements were restricted to patients with GOT histological grading of inflammation did not further improve the diagnostic accuracy of ***:Coexisting steatohepatitis markedly increases LS in patients with ALD independent of fibrosis stage. Postponing cirrhosis assessment by FS during alcohol withdrawal until GOT decreases to he diagnostic accuracy.

关键词： Alcoholic liver disease Alcoholic steatohep-atitis Liver cirrhosis Bilirubin Tissue elasticity imaging FibroScan