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101.
102.
Taghrid M. Gaafar Hala A. Abdel Rahman Wael Attia Hala S. Hamza Konrad Brockmeier Rabab E. El Hawary 《Clinical and experimental medicine》2014,14(2):177-184
Adult peripheral blood contains a limited number of endothelial progenitor cells that can be isolated for treatment of ischemic diseases. The adipose tissue became an interesting source of stem cells for regenerative medicine. This study aimed to investigate the phenotype of cells obtained by culturing adipose-derived mesenchymal stem cells (ad-MSCs) in the presence of endothelial growth supplements compared to endothelial cells obtained from umbilical cord blood (UCB). Passage 3 ad-MSCs and mononuclear layer from UCB were cultured in presence of endothelial growth media for 3 weeks followed by their characterization by flow cytometry and polymerase chain reaction. After culture in endothelial inductive media, ad-MSCs expressed endothelial genes and some endothelial marker proteins as CD31 and CD34, respectively. Adipose tissue could be a reliable source for easy obtaining, expanding and differentiating MSCs into endothelial-like cells for autologous cell-based therapy. 相似文献
103.
ukasz Bohdal Leon Kukieka Radosaw Patyk Katarzyna Koka Jarosaw Chodr Konrad Czyewski 《Materials》2022,15(1)
The work concerns an analysis of the wear mechanisms of punches in the nibbling process. The nibbling process is the multiple punching of holes or external contours using circular punches, the diameter of which is much smaller than the size of the punched shapes. Analytical, numerical and experimental studies were carried out. In the analytical solution, formulas for determining the pressures in the contact zone were developed, thus enabling a simple estimation of the designed nibbling tools. In numerical studies, the influence of the punch rounding radius on the fatigue wear was investigated. It has been shown that the change in the punch cutting edge radius from r = 0 mm to r = 0.5 mm enables a seven-fold increase in the fatigue wear resistance. It was found that the change in the punch cutting edge rounding radius has an impact on the quality of the product (the greater the radius r, the worse the technological quality of the product). In experimental studies, the abrasive wear process was primarily investigated. For this purpose, the nibbling process was tested on S235JR + AR steel sheets with tools made of NC11LV/1.2379 steel without any coating and with an AlCrTiN layer. It was found that the special AlCrTiN layer used allowed for an increase in the resistance to abrasive wear, and thus increased the service life by approx. three times. The last element of the work is an assessment of the technological quality of the product after nibbling depending on the degree and type of stamp wear (quantitative and qualitative assessment). 相似文献
104.
Daniel M. Baier Sven Grtz Babak Farhadi Jahromi Sarah Hellmann Konrad Bergheim Wilm Pickhardt Rochus Schmid Lars Borchardt 《RSC advances》2021,11(60):38026
The edge chlorination of the benchmark nanographenes triphenylene and hexa-peri-hexabenzocoronene is conducted mechanochemically. This approach overcomes solubility limitations and eliminates the need for elaborate chlorination conditions. Additionally, the planarization of oligophenylenes and their edge-chlorination can be combined in a one-pot approach requiring as little as 60 minutes.The edge chlorination of the benchmark nanographenes triphenylene and hexa-peri-hexabenzocoronene is conducted mechanochemically. Planarization and edge chlorination are combined which allows the preparation of chlorinated nanographenes in one step. 相似文献
105.
106.
Alexandre Staub Muriel Scherer Pascal Zehnder Adriaan Bernardus Spierings Konrad Wegener 《Materials》2022,15(7)
In recent years, the advancement of technology brought the laser powder bed fusion process to its industrialisation step. Despite all the advancements in process repeatability and general quality control, many challenges remain unsolved due to the intrinsic difficulties of the process, notably the residual stresses issue. This work aimed to assess the usability of Barkhausen noise analysis (BNA) for the residual stress in situ monitoring of laser powder bed fusion on Maraging steel 300 (18Ni-300/1.2709). After measuring the evolution of grain size distribution over process parameter changes, two series of experiments were designed. First, a setup with an external force allows to validate the working principle of BNA on the chosen material processed using LPBF. The second experiment uses on-plates samples with different residual stress states. The results show a good stability in microstructure, a prerequisite for BNA. In addition, the external load setup acknowledges that signal variation correlates with the induced stress state. Finally, the on-plate measurement shows a similar signal variation to what has been observed in the literature for residual stress variation. It is shown that BNA is a suitable method for qualitative residual stresses variation monitoring developed during the LPBF process and underlines that BNA is a promising candidate as an in situ measurement method. 相似文献
107.
Helga Konrad Theodor Karamfilov Uwe Wollina 《Journal of cosmetic and laser therapy》2013,15(4):181-184
BACKGROUND: Hailey-Hailey disease is an autosomal-dominant blistering disease affecting the intertriginous skin. Dermabrasion and ablative laser treatment are known to be curative. Sweating is a common aggravating factor. Botulinum toxin A (BTXA) has been shown to inhibit sudoriferic nerves. OBJECTIVE: To evaluate whether a treatment with BTXA induces remissions and can compete with ablative therapy. To compare dermabrasion with erbium:YAG laser therapy. METHOD: Case report with side-by-side comparison. We used intracutaneous BTXA on both sides of the submammary region. Four days later a limited area of 25 cm 2 on each side was treated with either dermabrasion or erbium:YAG laser. The follow-up was 12 months. RESULTS: Wound healing was complete within 7 days after erbium:YAG laser and two weeks after dermabrasion. Areas treated with BTXA alone also showed complete remission within two weeks. During a follow-up, no relapse occurred with either treatment. CONCLUSION: BTXA is capable of inducing remissions of Hailey-Hailey disease without abrasion for at least 12 months. Among ablative treatments, erbium: YAG laser therapy leads to a more rapid wound closure than dermabrasion, with both causing complete remissions. 相似文献
108.
Altered brain network integrity after childhood maltreatment: A structural connectomic DTI‐study 下载免费PDF全文
Childhood maltreatment is associated with alterations in neural architecture that potentially put these children at increased risk for psychopathology. Alterations in white matter (WM) tracts have been reported, however no study to date has investigated WM connectivity in brain networks in maltreated children to quantify global and local abnormalities through graph theoretical analyses of DTI data. We aimed for a multilevel investigation examining the DTI‐based structural connectome and its associations with basal cortisol levels of 25 children with documented maltreatment experiences before age 3, and 24 matched controls (age: 10.6 ± 1.75 years). On the global and lobar level, maltreated children showed significant reductions in global connectivity strength, local connectivity and increased path length, suggesting deviations from the small‐world network architecture previously associated with psychopathology. Reductions in global connectivity were associated with placement instability, attenuated cortisol secretion and higher levels of internalizing and externalizing behaviours. Regional measures revealed lower connectivity strength especially in regions within the ventromedial prefrontal cortex (vMPFC) in maltreated children. These findings show that childhood maltreatment is associated with systemic global neurodevelopmental alterations in WM networks next to regional alterations in areas involved in the regulation of affect. These alterations in WM organization could underlie global functional deficits and multi‐symptom patterns frequently observed in children with maltreatment experiences. Hum Brain Mapp 38:855–868, 2017. © 2016 Wiley Periodicals, Inc. 相似文献
109.
Deja M Denke C Weber-Carstens S Schröder J Pille CE Hokema F Falke KJ Kaisers U 《Critical care (London, England)》2006,10(5):R147-12
Introduction
We investigated health-related quality of life (HRQoL) and persistent symptoms of post-traumatic stress disorder (PTSD) in long-term survivors of acute respiratory distress syndrome (ARDS). We wished to evaluate the influence of PTSD on HRQoL and to investigate the influence of perceived social support during intensive care unit (ICU) treatment on both PTSD symptoms and HRQoL. 相似文献110.
Distinguishing mirror from glass is a challenging visual inference, because both materials derive their appearance from their surroundings, yet we rarely experience difficulties in telling them apart. Very few studies have investigated how the visual system distinguishes reflections from refractions and to date, there is no image-computable model that emulates human judgments. Here we sought to develop a deep neural network that reproduces the patterns of visual judgments human observers make. To do this, we trained thousands of convolutional neural networks on more than 750,000 simulated mirror and glass objects, and compared their performance with human judgments, as well as alternative classifiers based on “hand-engineered” image features. For randomly chosen images, all classifiers and humans performed with high accuracy, and therefore correlated highly with one another. However, to assess how similar models are to humans, it is not sufficient to compare accuracy or correlation on random images. A good model should also predict the characteristic errors that humans make. We, therefore, painstakingly assembled a diagnostic image set for which humans make systematic errors, allowing us to isolate signatures of human-like performance. A large-scale, systematic search through feedforward neural architectures revealed that relatively shallow (three-layer) networks predicted human judgments better than any other models we tested. This is the first image-computable model that emulates human errors and succeeds in distinguishing mirror from glass, and hints that mid-level visual processing might be particularly important for the task. 相似文献