339 research outputs found

    Influence of Carrier Gas Composition on the Stress of Al2O3 Coatings Prepared by the Aerosol Deposition Method

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    Al2O3 films were prepared by the aerosol deposition method at room temperature using different carrier gas compositions. The layers were deposited on alumina substrates and the film stress of the layer was calculated by measuring the deformation of the substrate. It was shown that the film stress can be halved by using oxygen instead of nitrogen or helium as the carrier gas. The substrates were annealed at different temperature steps to gain information about the temperature dependence of the reduction of the implemented stress. Total relaxation of the stress can already be achieved at 300 °C. The XRD pattern shows crystallite growth and reduction of microstrain while annealing

    Airway responses and inflammation in subjects with asthma after four days of repeated high-single-dose allergen challenge

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    Background: Both standard and low-dose allergen provocations are an established tool in asthma research to improve our understanding of the pathophysiological mechanism of allergic asthma. However, clinical symptoms are less likely to be induced. Therefore, we designed a protocol for repetitive high-dose bronchial allergen challenges to generate clinical symptoms and airway inflammation. Methods: A total of 27 patients aged 18 to 40 years with positive skin-prick tests and mild asthma underwent repetitive high-dose allergen challenges with household dust mites for four consecutive days. Pulmonary function and exhaled NO were measured at every visit. Induced sputum was analysed before and after the allergen challenges for cell counts, ECP, IL-5, INF-γ, IL-8, and the transcription factor Foxp3. Results: We found a significant decrease in pulmonary function, an increased use of salbutamol and the development of a late asthmatic response and bronchial hyperresponsiveness, as well as a significant induction of eNO, eosinophils, and Th-2 cytokines. Repeated provocation was feasible in the majority of patients. Two subjects had severe adverse events requiring prednisolone to cope with nocturnal asthma symptoms. Conclusions: Repeated high-dose bronchial allergen challenges resulted in severe asthma symptoms and marked Th-2-mediated allergic airway inflammation. The high-dose challenge model is suitable only in an attenuated form in diseased volunteers for proof-of-concept studies and in clinical settings to reduce the risk of severe asthma exacerbations. Trial registration: ClinicalTrials.govNCT0067720

    Intelligente Prozessvernetzung durch das Transmodul

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    Die Firma Schubert baut TLM-Verpackungsmaschinen. TLM bedeutet Top Loading Maschine, d.h. die Aufgabe einer TLM-Maschine ist in der Regel das Aufrichten, Befüllen und Verschließen von Schachteln. TLM-Maschinen bestehen aus Teilmaschinen, die über Transmodulstrecken miteinander verbunden sind. Transmodule transportieren Produkte und Verpackungseinheiten, die Prozessvernetzung wird einfacher und es ergeben sich neue Möglichkeiten

    Characeen-Wiederfunde im Bereich Teutschental - Röblingen - ein Nachtrag zur Roten Liste der Algen des Landes Sachsen-Anhalt

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    Der ehemalige Salzige See, eine natürliche Binnensalzstelle deren Geologie in HOYNINGEN-HUENE (1959) ausführlich beschrieben ist, wies offenbar bis zu seinem Verschwinden um 1890 eine reichhaltige Characeenflora auf. Belege dafür finden sich nicht nur in den regional benachbarten Herbarien der Universität Halle bzw. des Herbariums Haussknecht in Jena, auch in Kopenhagen, Stockholm, Helsinki und Montpellier sind Belege von z. B. Chara erinita (Synonym von Ch. canescens) aus dem Jahr 1853 anzutreffen, beschriftet von ALEXANDER BRAUN (1805-1877) mit "Am Mansfelder Salzsee in Thüringen". Vor allem der intensiven Sammeltätigkeit von A. BRAUN und O. BULNHEIM (1820-1865) verdanken wir eine gute Kenntnis über die ehemaligen Characeen-Vorkommen dieses Sees, der als bekannte Binnensalzstelle die Aufmerksamkeit vieler Botaniker auf sich zog und phykologisch als "locus elassieus" der Art Chara intermedia A. BRAUN in BRAUN, RABENHORST et STITZENBERGER 1859 auch eine bleibende internationale Bekanntheit erlangte (vgl. auch BLÜMEL 2004)

    Current Trends and Challenges in Electronic Procurement: An Empirical Study

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    The following paper presents results from a longitudinal study on the use of ICT for B2B-related business processes in large Swiss companies. In an empirical survey, 68 questionnaires were personally collected from procurement heads and sub-sequently analysed. The findings show that reduction of purchase prices is the top priority when goal-setting in procurement. Electronic orders and invoices are the business documents that are most often exchanged electronically between partners. Electronic exchange of invoices (e-invoicing) is a current key topic for over 70 % of the companies. Procurement heads sense a lack of supplier involvement which makes the realisation of balanced B2B solution scenarios difficult. The study shows that IT, without doubt, plays a significant role in everyday procurement, but that the expectations of IT are rarely completely fulfilled

    Influence of Oxygen Partial Pressure during Processing on the Thermoelectric Properties of Aerosol-Deposited CuFeO2

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    In the field of thermoelectric energy conversion, oxide materials show promising potential due to their good stability in oxidizing environments. Hence, the influence of oxygen partial pressure during synthesis on the thermoelectric properties of Cu-Delafossites at high temperatures was investigated in this study. For these purposes, CuFeO2 powders were synthetized using a conventional mixed-oxide technique. X-ray diffraction (XRD) studies were conducted to determine the crystal structures of the delafossites associated with the oxygen content during the synthesis. Out of these powders, films with a thickness of about 25 µm were prepared by the relatively new aerosol-deposition (AD) coating technique. It is based on a room temperature impact consolidation process (RTIC) to deposit dense solid films of ceramic materials on various substrates without using a high-temperature step during the coating process. On these dense CuFeO2 films deposited on alumina substrates with electrode structures, the Seebeck coefficient and the electrical conductivity were measured as a function of temperature and oxygen partial pressure. We compared the thermoelectric properties of both standard processed and aerosol deposited CuFeO2 up to 900 °C and investigated the influence of oxygen partial pressure on the electrical conductivity, on the Seebeck coefficient and on the high temperature stability of CuFeO2. These studies may not only help to improve the thermoelectric material in the high-temperature case, but may also serve as an initial basis to establish a defect chemical model

    Correlation from undiluted vitreous cytokines of untreated central retinal vein occlusion with spectral domain optical coherence tomography

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    Purpose: To correlate inflammatory and proangiogenic key cytokines from undiluted vitreous of treatment-naïve central retinal vein occlusion (CRVO) patients with SD-OCT parameters. Methods: Thirty-five patients (age 71.1 years, 24 phakic, 30 nonischemic) underwent intravitreal combination therapy, including a single-site 23-gauge core vitrectomy. Twenty-eight samples from patients with idiopathic, non-uveitis floaterectomy served as controls. Interleukin 6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and vascular endothelial growth factor (VEGF-A) levels were correlated with the visual acuity (logMar), category of CRVO (ischemic or nonischemic) and morphologic parameters, such as central macular thickness-CMT, thickness of neurosensory retina-TNeuro, extent of serous retinal detachment-SRT and disintegrity of the IS/OS and others. Results: The mean IL-6 was 64.7pg/ml (SD ± 115.8), MCP-1 1015.7 ( ± 970.1), and VEGF-A 278.4 ( ± 512.8), which was significantly higher than the control IL-6 6.2 ± 3.4pg/ml (P=0.06), MCP-1 253.2 ± 73.5 (P<0.0000001) and VEGF-A 7.0 ± 4.9 (P<0.0006). All cytokines correlated highly with one another (correlation coefficient r=0.82 for IL-6 and MCP-1; r=0.68 for Il-6 and VEGF-A; r=0.64 for MCP-1 and VEGF-A). IL-6 correlated significantly with CMT, TRT, SRT, dIS/OS, and dELM. MCP-1 correlated significantly with SRT, dIS/OS, and dELM. VEGF-A correlated not with changes in SD-OCT, while it had a trend to be higher in the ischemic versus the nonischemic CRVO group (P=0.09). Conclusions: The inflammatory cytokines were more often correlated with morphologic changes assessed by SD-OCT, whereas VEGF-A did not correlate with CRVO-associated changes in SD-OCT. VEGF inhibition alone may not be sufficient in decreasing the inflammatory response in CRVO therapy

    Expression of a large coding sequence: Gene therapy vectors for Ataxia Telangiectasia

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    Ataxia telangiectasia is a monogenetic disorder caused by mutations in the ATM gene. Its encoded protein kinase ATM plays a fundamental role in DNA repair of double strand breaks (DSBs). Impaired function of this kinase leads to a multisystemic disorder including immunodeficiency, progressive cerebellar degeneration, radiation sensitivity, dilated blood vessels, premature aging and a predisposition to cancer. Since allogenic hematopoietic stem cell (HSC) transplantation improved disease outcome, gene therapy based on autologous HSCs is an alternative promising concept. However, due to the large cDNA of ATM (9.2 kb), efficient packaging of retroviral particles and sufficient transduction of HSCs remains challenging.We generated lentiviral, gammaretroviral and foamy viral vectors with a GFP.F2A.Atm fusion or a GFP transgene and systematically compared transduction efficiencies. Vector titers dropped with increasing transgene size, but despite their described limited packaging capacity, we were able to produce lentiviral and gammaretroviral particles. The reduction in titers could not be explained by impaired packaging of the viral genomes, but the main differences occurred after transduction. Finally, after transduction of Atm-deficient (ATM-KO) murine fibroblasts with the lentiviral vector expressing Atm, we could show the expression of ATM protein which phosphorylated its downstream substrates (pKap1 and p-p53)

    Freisetzung kinetischer Energie und Hammond-Postulat bei der intramolekularen aromatischen Substitution in 2-Stilbazol-Ionen

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    Schubert R, Ramana DV, Grützmacher H-F. Freisetzung kinetischer Energie und Hammond-Postulat bei der intramolekularen aromatischen Substitution in 2-Stilbazol-Ionen. Chemische Berichte. 1980;113(12):3758-3774
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