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Slice Thickness Optimization for the Focused Ion Beam-Scanning Electron Microscopy 3D Tomography of Hierarchical Nanoporous Gold

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Nanomanufacturing and Metrology 2022年第2期5卷 112-118页

作者： Alexander Shkurmanov tobias krekeler Martin Ritter Electron Microscopy Unit Hamburg University of Technology(TUHH)Eißendorfer Straße 4221073HamburgGermany

The combination of focused ion beam (FIB) with scanning electron microscopy (SEM), also known as FIB-SEM tomography, has become a powerful 3D imaging technique at the nanometer scale. This method uses an ion beam to mill away a thin slice of material, which is then block-face imaged using an electron beam. With consecutive slicing along the z-axis and subsequent imaging, a volume of interest can be reconstructed from the images and further analyzed. Hierarchical nanoporous gold (HNPG) exhibits unique structural properties and has a ligament size of 15–110 nm and pore size of 5–20 nm. Accurate reconstruction of its image is crucial in determining its mechanical and other properties. Slice thickness is one of the most critical and uncertain parameters in FIB-SEM tomography. For HNPG, the slice thickness should be at least half as thin as the pore size and, in our approach, should not exceed 10 nm. Variations in slice thickness are caused by various microscope and sample parameters, e.g., converged ion milling beam shape, charging effects, beam drift, or sample surface roughness. Determining and optimizing the actual slice thickness variation appear challenging. In this work, we examine the influence of ion beam scan resolution and the dwell time on the mean and standard deviation of slice thickness. After optimizing the resolution and dwell time to achieve the target slice thickness and lowest possible standard deviation, we apply these parameters to analyze an actual HNPG sample. Our approach can determine the thickness of each slice along the z-axis and estimate the deviation of the milling process along the y-axis (slow imaging axis). For this function, we create a multi-ruler structure integrated with the HNPG sample.

关键词： Focused ion beam Scanning electron microscopy Tomography Hierarchical nanoporous gold

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Stimulation of p38 MAPk by hormal preconditioning with atrial natriuretic peptide

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World Journal of Gastroenterology 2002年第4期8卷 707-711页

作者： Alexandra k. kiemer Stefanie kulhanek-Heinze tobias Gerwig Alexander L. Gerbes Angelika M. Vollmar Department of Pharmacy Center of Drug ResearchUniversity of MunichGermany Department of Medicine ⅡKlinikum GrosshadernUniversity of MunichGermany Department of Medicine Ⅱ Klinikum GrosshadernUniversity of MunichGermany Department of Pharmacy Center of Drug ResearchUniversity of MunichGermany

AIM：Stress-activated signaling pathways responsible for hepatic ischemia reperfusion injury and their modulation by protective interventions are widely *** of rat livers with Atrial Natriuretic Peptide(ANP)attenuates ischemia reperfusion injury(Gerbes et ***1998,18:1309-1317),SinANP has recently been shown to be a regulator of the p38MAPkpathway in endothelial cells(kiemer et ***2002,90:874-881).aim of this thudy was to investigate activities of MAPk during ischemia and reperfusion and effects of ANP on ***:Rat livers were perfused with kH-buffer in the presence or absence of ANP for 20min,kept in cold UWsloution for 24h,and reperfused forupto120min,Activities of p38MAPkand JNkwas determined by in vitro phosphorylation assays using MBP and c-jun as *** SDS/PAGE electrophoresis,gels were quantified by ***:Activity of p38MAPkin control organs decreased in the course of ischemia and reperfusion by85%,whereas ANPincreased p38 activity by up to *** of control livers increased in the course of ischemia and reperfusion by up to *** increase in JNk activrity was slightly elevated in ANP preconditioned ***:This work represents a systematic investigation of MAPk activation during liver ischemia and *** ANP,for the first time a pharmacological approach to modulate these central signal transduction molecules is presented.

关键词：血浆心纳素 p38MAPk 缺血预处理肝脏缺血

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Regulatory T cells in viral hepatitis

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World Journal of Gastroenterology 2007年第36期13卷 4858-4864页

作者： Eva Billerbeck tobias Bttler Robert Thimme Department of Medicine Ⅱ University Hospital Freiburg Germany

The pathogenesis and outcome of viral infections are significantly influenced by the host immune response. The immune system is able to eliminate many viruses in the acute phase of infection. However, some viruses, like hepatitis C virus (HCV) and hepatitis B virus (HBV), can evade the host immune responses and establish a persistent infection. HCV and HBV persistence is caused by various mechanisms, like subversion of innate immune responses by viral factors, the emergence of T cell escape mutations, or T cell dysfunction and suppression. Recently, it has become evident that regulatory T cells may contribute to the pathogenesis and outcome of viral infections by suppressing antiviral immune responses. Indeed, the control of HCV and HBV specific immune responses mediated by regulatory T cells may be one mechanism that favors viral persistence, but it may also prevent the host from overwhelming T cell activity and liver damage. This review will focus on the role of regulatory T cells in viral hepatitis.

关键词： Regulatory T cells Viral hepatitis Immunoregulation

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Mixing Monte-Carlo and Partial Differential Equations for Pricing Options

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Chinese Annals of Mathematics,Series B 2013年第2期34卷 255-276页

作者： tobias LIPP Grgoire LOEPER Olivier PIRONNEAU LJLL-UPMC Boite 187Place Jussieu75252 Paris cedex 5France BNP-Paribas 20 Boulevard des Italiens75009 ParisFrance

There is a need for very fast option pricers when the financial objects are modeled by complex systems of stochastic differential *** the authors investigate option pricers based on mixed Monte-Carlo partial differential solvers for stochastic volatility models such as Heston'*** is found that orders of magnitude in speed are gained on full Monte-Carlo algorithms by solving all equations but one by a Monte-Carlo method,and pricing the underlying asset by a partial differential equation with random coefficients,derived by Ito *** strategy is investigated for vanilla options,barrier options and American options with stochastic volatilities and jumps optionally.

关键词： Monte-Carlo Partial differential equations Heston model Financial mathematics. Option pricing

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Role of amygdala in mediating sexual and emotional behavior via coupled nitric oxide release

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Acta Pharmacologica Sinica 2005年第4期26卷 389-395页

作者： Elliott SALAMON tobias ESCH George B STEFANO Neuroscience Research Institute State University of New York College at Old Westbury Old Westbury New York 11568 USA Neuroscience Research Institute State University of New York College at Old Westbury Old Westbury New York 11568 USA Charit University Medicine Berlin Institute for General Practice and Family Medicine Schumannstrasse 10117 Berlin Germany Neuroscience Research Institute State University of New York College at Old Westbury Old Westbury New York 11568 USA

Although the anatomical configuration of the amygdala has been studied a greatdeal,very little research has been conducted on understanding the precise mecha-nism by which this emotional regulatory center exerts its control on emotional andsexual *** applying research methodology from the Neuroscience Re-search Institute,State University of New York,College at Old Westbury,we in-tended to demonstrate that much of the mediated effects of the amygdala,specifi-cally the regulation of the male and female sexual response cycles,as well asrelated emotional considerations,exert their effects coupled to nitric oxide (NO)***,by using current anatomical and histological data,wedemonstrated that amygdalar tissue rich in endocannabinoid and opiate,as wellas catecholamine,receptors could exert its neurochemical effects within an NO-mediated *** paradigm,together with the existence of estrogen andandrogen signaling within the amygdala,further lends credence to our *** begin with a brief anatomical and functional review of amygdalarfunction,and then proceed to demonstrate its relationship with NO.

关键词： amygdala sex nitric oxide morphine emotion

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Stop flow lithography synthesis of non-spherical metal oxide particles

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Particuology 2014年第3期12卷 91-97页

作者： David Baah tobias Donnell Julaunica Tigner Tamara Floyd-Smith Materials Science & Engineering Department Tuskegee UniversityTuskegeeAL 36088USA Chemical Engineering Department Tuskegee UniversityTuskegeeAL 36088USA

Non-spherical micron and hand-sized particles and their composites have become essential in select application areas of optics, wear resistance, personnel protection, chemical mechanical polishing, and biomedicine. In this paper, the synthesis of composite and ceramic non-spherical particles using stop flow lithography is reported. Precursor suspensions of poly（ethylene glycol） diacrylate, 2-hydroxy- 2-methylpropiophenone and SiO2 or Al2O3 are prepared. The precursor suspension flows through a microfluidic device mounted on an upright microscope and is polymerized in an automated process. A photomask patterned with transparent geometric features, which define the cross-sectional shapes of the particles, masks the UV light to synthesize micron sized particles. Particles with axial dimensions ranging from 35 to 167μm were synthesized. Control of device channel depth and objective lens magnification enables the manipulation of the particle size. Composite particles in triangular, square, pentagonal, hexagonal, and circular cross sections were synthesized. Subsequently, the transformation of the composite particles into the corresponding metal oxide particles was achieved through polymer burn-offand sintering.

关键词： Microfluidics Stop flow lithography Electron microscopy

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Advancement in utilization of magnetic resonance imaging and biomarkers in the understanding of schizophrenia

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World Journal of Clinical Cases 2025年第1期13卷 11-15页

作者： Aidan k Tirpack Danyaal G Buttar Mandeep kaur Department of Psychiatry Campbell University School of Osteopathic MedicineBuies CreekNC 27506United States Department of Psychiatry and Behavioral Health Mercyhealth Hospital and Trauma CenterJanesvilleWI 53548United States

Historically,psychiatric diagnoses have been made based on patient’s reported symptoms applying the criteria from diagnostic and statistical manual of mental *** utilization of neuroimaging or biomarkers to make the diagnosis and manage psychiatric disorders remains a distant *** have been several studies that examine brain imaging in psychiatric disorders,but more work is needed to elucidate the complexities of the human *** this editorial,we examine two articles by Xu et al and Stoyanov et al,that show developments in the direction of using neuroimaging to examine the brains of people with schizo-phrenia and *** et al used magnetic resonance imaging to examine the brain structure of patients with schizophrenia,in addition to examining neurotransmitter levels as *** et al used functional magnetic resonance imaging to look at modulation of different neural circuits by diagnostic-specific scales in patients with schizophrenia and *** two studies provide crucial evidence in advancing our understanding of the brain in prevalent psychiatric disorders.

关键词： Schizophrenia Magnetic resonance imaging Biomarkers Neurotransmitters Psychiatric disorders

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Clinical outcome and predictors of survival after TIPS insertion in patients with liver cirrhosis

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World Journal of Gastroenterology 2012年第37期18卷 5211-5218页

作者： Hauke S Heinzow Philipp Lenz Michael khler Frank Reinecke Hansjrg Ullerich Wolfram Domschke Dirk Domagk tobias Meister Department of Medicine B University of Muenster Institute of Radiology University of Muenster Department of Medicine Ⅱ Helios Albert-Schweitzer-Hospital

AIM： To determine the clinical outcome and predictors of survival after transjugular intrahepatic portosystemic stent shunt （TIPS） implantation in cirrhotic patients. METHODS： Eighty-one patients with liver cirrhosis and consequential portal hypertension had TIPS implanta- tion （bare metal） for either refractory ascites （RA）（n = 27） or variceal bleeding （VB）（n = 54）. Endpoints for the study were： technical success, stent occlusion and stent stenosis, rebleeding, RA and mortality. Clini- cal records of patients were collected and analysed. Baseline characteristics [e.g., age, sex, CHILD score and the model for end-stage liver disease score （MELD score）, underlying disease] were retrieved. The kaplan- Meier method was employed to calculate survival from the time of TIPS implantation and comparisons were made by log rank test. A multivariate analysis of factors influencing survival was carried out using the Cox pro- portional hazards regression model. Results were ex- pressed as medians and ranges. Comparisons between groups were performed by using the Mann-Whitney U-test and the4,2 test as appropriate. RESULTS： No difference could be seen in terms of age, sex, underlying disease or degree of portal pressure gradient （PPG） reduction between the ascites and the bleeding group. The PPG significantly decreased from 23.4 ± 5.3 mmHg （VB） vs 22.1± 5.5 mmHg （RA） be- fore TIPS to 11.8 ±4.0 vs 11.7 ± 4.2 after TIPS im- plantation （P = 0.001 within each group）. There was a tendency towards more patients with stage CHILD A in the bleeding group compared to the ascites group （24 vs 6, P = 0.052）. The median survival for the ascites group was 29 mo compared to 〉 60 mo for the bleed- ing group （P = 0.009）. The number of radiological con- trols for stent patency was 6.3 for bleeders and 3.8 for ascites patients （P = 0.029）. kaplan-Meier calculation indicated that stent occlusion at first control （P = 0.027）, ascites prior to TIPS implantation （P = 0.009）, CHILD stage （P = 0.013）, M

关键词： Transjugular intrahepatic portosystemicstent shunt Liver cirrhosis Ascites Gastrointestinalhemorrhage Treatment outcome

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A concurrent optimization approach for energy efficient multiple axis positioning tasks

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Journal of Control and Decision 2016年第4期3卷 223-247页

作者： Christian Hansen Jens kotlarski tobias Ortmaier Institute of Mechatronic Systems Leibniz Universitat HannoverHanoverGermany

Automated production systems typically comprise numerous electrical servo drives,many of which conduct positioning motions,*** handling or manipulation *** power electronics of modern multi-axis systems often comprise coupled DC-links,enabling for internal exchange of recuperative brake ***,the motion sequences of manipulators are often commanded at maximum dynamics for minimum time motion,neglecting possible optimization potential,*** idle time,leading to inefficient energy management.A robust trajectory optimization approach based on the particle swarm algorithm and well-established path planning methods is presented for the adaption of multi-axis positioning tasks with only two parameters per axis and positioning motion during system *** results prove that,depending on the positioning task and chosen optimization constraints,energy demands are distinctly *** approach is applicable to diverse multi-axis configurations and enables for considerable energy savings without additional hardware invest.

关键词： Multiple axis systems electrical servo drive energy efficient control trajectory optimization positioning tasks

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Sex ratio variation and sex determination in the mallee dragon Ctenophorus fordi

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Integrative Zoology 2008年第3期3卷 157-165页

作者： tobias ULLER Gaetano ODIERNA Mats OLSSON School of Biological Sciences University of WollongongWollongongNew South WalesAustralia Department of Structural and Functional Biology University of Naples Federico IINaplesItaly

Recent evidence suggests that many Australian agamids show temperature-dependent sex determination(TSD)with variation in sex determining mechanisms among closely related ***,as shown in other vertebrates,sex ratios can also be influenced by genetic or phenotypic differences among females in their propensity to produce sons or daughters,and these influences might confound any thermal effects of incubation per *** address these issues,we investigated the determinants of sex ratios in the mallee dragon Ctenophorus fordi,together with a detailed analysis of *** was no detectable variation in sex ratios arising from variation among females,clutches or incubation temperatures,which might indicate genetic sex determination for this ***,there was no evidence of cytologically distinct sex chromosomes using standard banding *** sex ratio pattern in *** strongly contrasts with the results for the congener Ctenophorus pictus,where sex ratios show variation among ***,Australian agamids offer promising opportunities to address fundamental issues in sex ratio biology.

关键词： genetic-dependent sex determination lizard sex ratio sex allocation temperature-dependent sex determination.

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