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排序方式: 共有108条查询结果,搜索用时 62 毫秒
11.
Isabel Medina Lukas Schmitt Viktoria Kapoustina Stephan Scholl Matthias Rädle 《化学,工程师,技术》2019,91(7):1041-1048
An online image analysis method to determine the film thickness in fluids by use of pulsed near infrared LEDs and an NIR camera was developed. This technique offers the possibility to monitor moving fluid layers. In this work the possibilities and limits of the used apparatus are demonstrated with the application example of measurement of the fluid film thickness distribution of water and glycerol in a falling film. 相似文献
12.
Liudmila Zakharova Viktoria Sharova Marina Izvolskaia 《International journal of molecular sciences》2021,22(1)
Different aspects of the reciprocal regulatory influence on the development of gonadotropin-releasing hormone (GnRH)-producing- and immune systems in the perinatal ontogenesis and their functioning in adults in normal and pathological conditions are discussed. The influence of GnRH on the development of the immune system, on the one hand, and the influence of proinflammatory cytokines on the development of the hypothalamic-pituitary-gonadal system, on the other hand, and their functioning in adult offspring are analyzed. We have focused on the effects of GnRH on the formation and functional activity of the thymus, as the central organ of the immune system, in the perinatal period. The main mechanisms of reciprocal regulation of these systems are discussed. The reproductive health of an individual is programmed by the establishment and development of physiological systems during critical periods. Regulatory epigenetic mechanisms of development are not strictly genetically controlled. These processes are characterized by a high sensitivity to various regulatory factors, which provides possible corrections for disorders. 相似文献
13.
Sobha Karuthedom George Lucia Laukov Ren Weiss Vladislav Semak Birgit Fendl Victor U. Weiss Stephanie Steinberger Günter Allmaier Carla Tripisciano Viktoria Weber 《International journal of molecular sciences》2021,22(8)
Growing interest in extracellular vesicles (EVs) has prompted the advancements of protocols for improved EV characterization. As a high-throughput, multi-parameter, and single particle technique, flow cytometry is widely used for EV characterization. The comparison of data on EV concentration, however, is hindered by the lack of standardization between different protocols and instruments. Here, we quantified EV counts of platelet-derived EVs, using two flow cytometers (Gallios and CytoFLEX LX) and nanoparticle tracking analysis (NTA). Phosphatidylserine-exposing EVs were identified by labelling with lactadherin (LA). Calibration with silica-based fluorescent beads showed detection limits of 300 nm and 150 nm for Gallios and CytoFLEX LX, respectively. Accordingly, CytoFLEX LX yielded 40-fold higher EV counts and 13-fold higher counts of LA+CD41+ EVs compared to Gallios. NTA in fluorescence mode (F-NTA) demonstrated that only 9.5% of all vesicles detected in scatter mode exposed phosphatidylserine, resulting in good agreement of LA+ EVs for CytoFLEX LX and F-NTA. Since certain functional characteristics, such as the exposure of pro-coagulant phosphatidylserine, are not equally displayed across the entire EV size range, our study highlights the necessity of indicating the size range of EVs detected with a given approach along with the EV concentration to support the comparability between different studies. 相似文献
14.
Saman Nimali Gunasekara Monika Ignatowicz Justin NingWei Chiu Viktoria Martin 《国际能源研究杂志》2019,43(5):1785-1801
This work presents and discusses a detailed thermal conductivity assessment of erythritol, xylitol, and their blends: 25 mol% erythritol and 80 mol% erythritol using the transient plane source (TPS) method with a Hot Disk Thermal Constants Analyzer TPS‐2500S. Thereby, the thermal conductivities of xylitol, 25 mol% erythritol, 80 mol% erythritol, and erythritol were here found for respectively in the solid state to be 0.373, 0.394, 0.535, and 0.589 W m?1 K?1 and in the liquid state to be 0.433, 0.402, 0.363, and 0.321 W m?1 K?1. These obtained results are comprehensively and critically analyzed as compared to available literature data on the same materials, in the phase change materials (PCMs) design context. This study clearly indicates that these thermal conductivity data in literature have considerable discrepancies between the literature sources and as compared to the data obtained in the present investigation. Primary reasons for these disparities are identified here as the lack of sufficiently transparent and repeatable data and procedure reporting, and relevant standards in this context. To exemplify the significance of such transparent and repeatable data reporting in thermal conductivity evaluations in the PCM design context, here focused on the TPS method, a comprehensive measurement validation is discussed along various residual plots obtained for varying input parameters (ie, the heating power and time). Clearly, the variations in the input parameters give rise to various thermal conductivity results, where choosing the most coherent result requires a sequence of efforts per material, because there are no universally valid conditions. Transparent and repeatable data and procedure reporting are the key to achieve comparable thermal conductivity results, which are essential for the correct design of thermal energy storage systems using PCMs. 相似文献
15.
Species‐specific fish larvae drift in anthropogenically constructed riparian zones on the Vienna impoundment of the River Danube,Austria: Species occurrence,frequencies, and seasonal patterns based on DNA barcoding
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Paul Meulenbroek Silke Drexler Daniela Huemer Stephanie Gruber Susanne Krumböck Pablo Rauch Christian Stauffer Viktoria Waidbacher Sabine Zirgoi Matthias Zwettler Herwig Waidbacher 《河流研究与利用》2018,34(7):854-862
As a result of river regulations over several centuries, followed by restoration measures in recent decades, most of the River Danube shoreline is man‐made, primarily riprap, but some reconstructed gravel banks and riparian side arms. We investigated the effects of these different structures on fish larval dispersal over a 20‐km stretch in Vienna via the use of drift nets. The habitats examined were created 18 years ago when the impoundment of the Danube hydropower station Vienna/Freudenau was constructed. About 15,000 fish larvae were trapped, and a subsample was determined to species level by DNA barcoding. In total, 26 different species were detected, including 10 species that are endangered or in danger of extinction. When species composition was considered, cyprinids become dominant at sites downstream of gravel bars, whereas in riprap sections, the majority of the larvae consist of invasive Gobiidae. Side arm habitats provide spawning and nursery grounds for additional species. Furthermore, clear species‐related seasonal patterns were observed with peak densities and multiple spawning periods of some species being recorded. The largest peak of Percidae occurred in the first half of May, followed by Cyprinidae at the end of May and Gobiidae in mid‐June. 相似文献
16.
Stefanie Viktoria Caroline Schulte 《国际水》2019,44(4):427-443
California introduced its first comprehensive groundwater legislation (the Sustainable Groundwater Management Act) in 2014 to address the overuse of the state’s groundwater resources and to establish a pathway for sustainable groundwater use. However, a recent decision by the US Court of Appeals for the Ninth Circuit declaring the existence of federal reserved rights to groundwater could complicate the future implementation of California’s new groundwater legislation. This article explores the impact of the case and offers recommendations on how the tensions between the court’s decision and the existing legal framework for groundwater management in California could be reduced. 相似文献
17.
Sarah Meister Laura Hahn Susanne Beyer Corinna Paul Sophie Mitter Christina Kuhn Viktoria von Schnfeldt Stefanie Corradini Kritika Sudan Christian Schulz Theresa Maria Kolben Sven Mahner Udo Jeschke Thomas Kolben 《International journal of molecular sciences》2021,22(22)
The aim of this study was to analyze the expression of peroxisome proliferator-activated receptor γ (PPARγ) and retinoid X receptor α (RxRα), a binding heterodimer playing a pivotal role in the successful trophoblast invasion, in the placental tissue of preeclamptic patients. Furthermore, we aimed to characterize a possible interaction between PPARγ and H3K4me3 (trimethylated lysine 4 of the histone H3), respectively H3K9ac (acetylated lysine 9 of the histone H3), to illuminate the role of histone modifications in a defective trophoblast invasion in preeclampsia (PE). Therefore, the expression of PPARγ and RxRα was analyzed in 26 PE and 25 control placentas by immunohistochemical peroxidase staining, as well as the co-expression with H3K4me3 and H3K9ac by double immunofluorescence staining. Further, the effect of a specific PPARγ-agonist (Ciglitazone) and PPARγ-antagonist (T0070907) on the histone modifications H3K9ac and H3K4me3 was analyzed in vitro. In PE placentas, we found a reduced expression of PPARγ and RxRα and a reduced co-expression with H3K4me3 and H3K9ac in the extravillous trophoblast (EVT). Furthermore, with the PPARγ-antagonist treated human villous trophoblast (HVT) cells and primary isolated EVT cells showed higher levels of the histone modification proteins whereas treatment with the PPARγ-agonist reduced respective histone modifications. Our results show that the stimulation of PPARγ-activity leads to a reduction of H3K4me3 and H3K9ac in trophoblast cells, but paradoxically decreases the nuclear PPARγ expression. As the importance of PPARγ, being involved in a successful trophoblast invasion has already been investigated, our results reveal a pathophysiologic connection between PPARγ and the epigenetic modulation via H3K4me3 and H3K9ac in PE. 相似文献
18.
Huixia Yang Zhi Ma Lin Peng Christina Kuhn Martina Rahmeh Sven Mahner Udo Jeschke Viktoria von Schnfeldt 《International journal of molecular sciences》2021,22(16)
Epigenetics play a vital role in early embryo development. Offspring conceived via assisted reproductive technologies (ARTs) have a three times higher risk of epigenetic diseases than naturally conceived children. However, investigations into ART-associated placental histone modifications or sex-stratified analyses of ART-associated histone modifications remain limited. In the current study, we carried out immunohistochemistry, chip-sequence analysis, and a series of in vitro experiments. Our results demonstrated that placentas from intra-cytoplasmic sperm injection (ICSI), but not in vitro fertilization (IVF), showed global tri-methylated-histone-H3-lysine-4 (H3K4me3) alteration compared to those from natural conception. However, for acetylated-histone-H3-lysine-9 (H3K9ac) and acetylated-histone-H3-lysine-27 (H3K27ac), no significant differences between groups could be found. Further, sex -stratified analysis found that, compared with the same-gender newborn cord blood mononuclear cell (CBMC) from natural conceptions, CBMC from ICSI-boys presented more genes with differentially enriched H3K4me3 (n = 198) than those from ICSI-girls (n = 79), IVF-girls (n = 5), and IVF-boys (n = 2). We also found that varying oxygen conditions, RNA polymerase II subunit A (Polr2A), and lysine demethylase 5A (KDM5A) regulated H3K4me3. These findings revealed a difference between IVF and ICSI and a difference between boys and girls in H3K4me3 modification, providing greater insight into ART-associated epigenetic alteration. 相似文献
19.
Natalia K. Kondrasheva Dmitrey O. Kondrashev Rostislav R. Konoplin Ksenia I. Smyshlyaeva Viktoria S. Shakleina 《Petroleum Science and Technology》2013,31(24):2099-2105
AbstractThe influence of depressant and depressant-dispersing additives injection in the amount of less than 0.75% on low-temperature properties of marine fuels and their distillate compounds is presented in this research paper. As tested components were used the following industry-derived components: hydrotreated straight-run diesel fraction (HSRDF), ultra-low sulfur content hydro-creaking diesel fuel (ULSDH), light gas oil delayed coking and light gas oil catalytic creaking (LGODC and LGOCC), light vacuum gas oil (LVGO) and visbreaker residue (VR). As marine fuels samples the compounds based on described above components were used. The influence of the following additives was studied: SEVILEN 11606-40, KOLTEK DN 3149, Dodiflow 5934 and DPN-172. 相似文献
20.
Automatic image annotation using visual content and folksonomies 总被引:2,自引:4,他引:2
Stefanie Lindstaedt Roland Mörzinger Robert Sorschag Viktoria Pammer Georg Thallinger 《Multimedia Tools and Applications》2009,42(1):97-113
Automatic image annotation is an important and challenging task, and becomes increasingly necessary when managing large image collections. This paper describes techniques for automatic image annotation that take advantage of collaboratively annotated image databases, so called visual folksonomies. Our approach applies two techniques based on image analysis: First, classification annotates images with a controlled vocabulary and second tag propagation along visually similar images. The latter propagates user generated, folksonomic annotations and is therefore capable of dealing with an unlimited vocabulary. Experiments with a pool of Flickr images demonstrate the high accuracy and efficiency of the proposed methods in the task of automatic image annotation. Both techniques were applied in the prototypical tag recommender “tagr”. 相似文献