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1.
Single-channel properties of a delayed rectifier voltage-gated K+ channel (I-type) were investigated in peripheral myelinated axons from Xenopus laevis. Channels activated between -60 and -40 mV with a potential of half-maximal activation, E50, at -47.5 mV. Averaged single-channel currents activated with a time delay at all membrane potentials tested. Time to half-maximal activation decreased from 80 to 1.6 msec between -60 and +40 mV. The channel inactivated monoexponentially with a time constant of 10.9 sec at -40 mV. The time constant of deactivation was 126 msec at -80 mV and 16.9 msec at -110 mV. In symmetrical 105 mM K+, the single-channel conductance (gamma) was 22 and 13 pS at negative and positive membrane potentials, respectively, at 13-15 degrees C. In Na+ -rich solution with 2.5 mM extracellular K+ gamma was 7 pS and the reversal potential was negative to -80 mV, indicating a high selectivity for K+ over Na+. gamma depended on extracellular K+ concentration (KD = 19.6 mM) and temperature (Q10 = 1.45). External tetraethylammonium (TEA) reduced the apparent single-channel amplitude at all potentials tested with a half-maximal inhibiting concentration (IC50) of 0.6 mM. Open probability of the channel, but not single-channel current amplitude was decreased by extracellular dendrotoxin (DTX, IC50 = 6.8 nM). mast cell degranulating peptide (MCDP, IC50 = 41.9 microM). In Ringer solution the membrane potential of macroscopic I-channel patches was about -65 mV and depolarized under TEA and DTX. It is concluded that besides their activation during action potentials, I-channels may also stabilize the resting membrane potential.  相似文献   
2.
Ohne ZusammenfassungIch möchte nicht versäumen, an dieser Stelle Herrn Prof. Dr. Heß zu danken für bereitwilliges Entgegenkommen und tatkräftige Unterstützung bei Durchführung und Abfassung der Arbeit. Herrn Prof. Dr. Leonhard und Herrn Dozent Dr. Schmid habe ich zu danken für wertvolle Ratschläge. Der deutschen Forschungsgemeinschaft, die die Mittel zur Durchführung der Arbeit zur Verfügung stellte, sage ich dafür meinen Dank.Vorliegender Aufsatz ist eine zusammenfassende Darstellung einer von der Technischen Hochschule Stuttgart genehmigten Dissertation.  相似文献   
3.
Necrotizing fasciitis is a rare soft tissue infection with a high rate of mortality. Decreased capacity of the immune response is the overall disposing factor. Necrotizing fasciitis can develop very rapidly, and a rapid diagnosis and aggressive surgery provides the best prognosis.  相似文献   
4.
A realistic solution of the "relativistic EPR dilemma" is proposed. The stated dilemma refers to the fact that a realistic account of nonlocal correlations in quantum theory as in EPR-type experiments, for example is faced with the problem of an apparently ambiguous choice for the time-ordering of events. However, if one takes into consideration Arno Bohm's concept of a "preparation time" for any quantum mechanical setup, and if one does so for all world-lines of the experimental setup, one can show that a realistic account of events is perfectly feasible. In this way, a unique and time-irreversible ordering of events is guaranteed for each reference frame.  相似文献   
5.
Material parameters such as the permeability of dry reinforcing textiles are key variables for modern composite production using liquid composite molding (LCM) technique. Nowadays numerical filling simulations are required for predicting the mold filling behavior. Inaccurate predictions can lead to a high risk of air inclusion and corresponding need for cost‐intense revision of the mold design. Permeability values of the textiles used in the process are basic requirements for a numerical filling simulation, since the permeability is directly linked to the filling behavior. Nevertheless, the permeability values of non‐crimped fabrics (NCF) which are used for aerospace and automotive structures are rare. In this study the influence of textile parameters of NCF on the in‐plane permeability has been investigated using a capacitive in‐plane permeability measurement technology. The results show the influence of the roving filament number as well as the used stitch length on the in‐plane permeability. It is confirmed that the textile grammage is not affecting the in‐plane permeability of NCF reinforcements. The results of this study are valuable for textile selection with specific permeability data as well as for numerical filling simulations. POLYM. COMPOS., 37:1854–1863, 2016. © 2015 Society of Plastics Engineers  相似文献   
6.
This article describes the development of the Violence and Aggression in Health Care Questionnaire (VAQ) and the application of the measure in the field of home care. In a 1st sample of 361 German home care workers, the scales of the VAQ reached internal consistencies from .72 to .93. A confirmatory factor analysis gave evidence to the hypothesized factor structure. Significant correlation with indicators of psychophysical strain and health resulted in a 2nd sample of 180 home care workers. In multiple regression analysis based on a 3rd sample of 180 home care workers, verbal aggression by patients was a significant predictor of negative psychological outcomes. The relationship is completely mediated by negative emotional reactions after aggressive incidents. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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8.
X-chromosomal retinitis pigmentosa (RP) frequently is caused by mutations in the retinitis pigmentosa GTPase regulator (RPGR) gene. We evaluated the potential of PTC124 (Ataluren, TranslamaTM) treatment to promote ribosomal read-through of premature termination codons (PTC) in RPGR. Expression constructs in HEK293T cells showed that the efficacy of read-through reagents is higher for UGA than UAA PTCs. We identified the novel hemizygous nonsense mutation c.1154T > A, p.Leu385* (NM_000328.3) causing a UAA PTC in RPGR and generated patient-derived fibroblasts. Immunocytochemistry of serum-starved control fibroblasts showed the RPGR protein in a dot-like expression pattern along the primary cilium. In contrast, RPGR was no longer detectable at the primary cilium in patient-derived cells. Applying PTC124 restored RPGR at the cilium in approximately 8% of patient-derived cells. RT-PCR and Western blot assays verified the pathogenic mechanisms underlying the nonsense variant. Immunofluorescence stainings confirmed the successful PTC124 treatment. Our results showed for the first time that PTC124 induces read-through of PTCs in RPGR and restores the localization of the RPGR protein at the primary cilium in patient-derived cells. These results may provide a promising new treatment option for patients suffering from nonsense mutations in RPGR or other genetic diseases.  相似文献   
9.
We have investigated the structure and magnetism of self-assembled, 20 nm diameter iron oxide nanoparticles covered by an oleic acid shell for scrutinizing their structural and magnetic correlations. The nanoparticles were spin-coated on an Si substrate as a single monolayer and as a stack of 5 ML forming a multilayer. X-ray scattering (reflectivity and grazing incidence small-angle scattering) confirms high in-plane hexagonal correlation and a good layering property of the nanoparticles. Using polarized neutron reflectivity we have also determined the long range magnetic correlations parallel and perpendicular to the layers in addition to the structural ones. In a field of 5 kOe we determine a magnetization value of about 80% of the saturation value. At remanence the global magnetization is close to zero. However, polarized neutron reflectivity reveals the existence of regions in which magnetic moments of nanoparticles are well aligned, while losing order over longer distances. These findings confirm that in the nanoparticle assembly the magnetic dipole-dipole interaction is rather strong, dominating the collective magnetic properties at room temperature.  相似文献   
10.
A simple synthetic route to the preparation of a thin ZnS shell on CdSe quantum dot cores from the air-stable, single-molecular precursor zinc diethyldithiocarbamate, Zn(S(2)CNEt(2))(2), in the three-component solvent system octadec-1-ene/oleylamine/tri-n-octylphosphine (ODE/OLA/TOP) is presented. The one-pot synthesis proceeds through heating of the solution of CdSe cores and the amount of crystalline Zn(S(2)CNEt(2))(2) corresponding to a shell thickness of two monolayers of ZnS to 110-120 °C for 1-2 h. The role of the surfactants OLA and TOP and the significance of the temperature and the amount of Zn(S(2)CNEt(2))(2) have been investigated with optical absorption and luminescence spectroscopy. We show that the presence of both OLA and TOP is crucial for the low-temperature growth and that the amount of precursor corresponding to two monolayers of ZnS results in the highest quality of core/shell CdSe/ZnS quantum dots.  相似文献   
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