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排序方式: 共有1370条查询结果,搜索用时 15 毫秒
1.
Jonas Ort Benedikt Kremer Linda Grüßer Romy Blaumeiser-Debarry Hans Clusmann Mark Coburn Anke Hllig Ute Lindauer 《International journal of molecular sciences》2020,21(23)
Effective pharmacological neuroprotection is one of the most desired aims in modern medicine. We postulated that a combination of two clinically used drugs—nimodipine (L-Type voltage-gated calcium channel blocker) and amiloride (acid-sensing ion channel inhibitor)—might act synergistically in an experimental model of ischaemia, targeting the intracellular rise in calcium as a pathway in neuronal cell death. We used organotypic hippocampal slices of mice pups and a well-established regimen of oxygen-glucose deprivation (OGD) to assess a possible neuroprotective effect. Neither nimodipine (at 10 or 20 µM) alone or in combination with amiloride (at 100 µM) showed any amelioration. Dissolved at 2.0 Vol.% dimethyl-sulfoxide (DMSO), the combination of both components even increased cell damage (p = 0.0001), an effect not observed with amiloride alone. We conclude that neither amiloride nor nimodipine do offer neuroprotection in an in vitro ischaemia model. On a technical note, the use of DMSO should be carefully evaluated in neuroprotective experiments, since it possibly alters cell damage. 相似文献
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A technology for surface micromachining of free-standing metal microstructures using metal electrodeposition on a sacrificial photoresist layer has been applied to a condenser microphone. Electroplating technology has been used to implement a suspended and perforated 15-μm-thick microstructure in copper, which serves as backplate electrode in the condenser microphone. The 1.8×1.8 mm 2 large microphone diaphragm is in monocrystalline silicon and is fabricated with anisotropic etching of the substrate wafer. The realized prototypes have a measured sensitivity of 1.4 mV/Pa using a bias voltage of 28 V. The bandwidth is limited by an anti-resonance at 14 kHz which is due to the semi-rigid backplate. The resonance behavior of the backplate structure has been analyzed with finite element modeling with results in good agreement with measured data 相似文献
4.
A probabilistic model for cleavage fracture with a length scale--parameter estimation and predictions of stationary crack experiments 总被引:1,自引:0,他引:1
This study presents a large experimental investigation in the transition temperature region on a modified A508 steel. Tests were carried out on single-edge-notch-bend specimens with three different crack depth over specimen width ratios to capture the strong constraint effect on fracture toughness. Three test temperatures were considered, covering a range of 85 °C. All specimens failed by cleavage fracture prior to ductile tearing. A recently proposed probabilistic model for the cumulative failure by cleavage was applied to the comprehensive sets of experimental data. This modified weakest link model incorporates a length scale, which together with a threshold stress reduce the scatter in predicted toughness distributions as well as introduces a fracture toughness threshold value. Model parameters were estimated by a robust procedure, which is crucial in applications of probabilistic models to real structures. The conformity between predicted and experimental toughness distributions, respectively, were notable at all the test temperatures. 相似文献
5.
Jonas Berghel 《Drying Technology》2005,23(5):1027-1041
This article presents experimental results for spouted bed drying of sawdust, carried out in a full-scale as well as in a laboratory-scale dryer using air as well as steam as drying media. The aim is to present design parameters for a spouted-bed sawdust dryer that can be used by the industry in designing full-scale dryers. A hydrodynamically stable spouted jet spouted bed was obtained. The heat transfer characteristics of the bed were represented in terms of a volumetric heat transfer coefficient (VHC). When sawdust is dried in a spouted bed, the mean VHC is increasing up to fiber saturation level (20-25% wb) from 40 to 110 W/m3 K. The VHC decreases with the residence time and with an increased static bed height. Gas temperature profiles are also presented for the bottom part of the drying chamber. 相似文献
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For this study, 194 respondents completed a biographical data sheet, the Templer (1970) Death Anxiety Scale and the Constantinople (1973) Inventory of Psychosocial Development to help assess the relationship among death anxiety, age, and psychosocial maturity. Findings showed that psychosocial maturity was a better predictor of death anxiety than age was. However, both variables were significantly negatively correlated with death anxiety, revealing that as psychosocial maturity and age increase, death anxiety decreases. 相似文献
8.
J Gurevitch B Sela A Jonas H Golan Y Yahav JH Passwell 《Canadian Metallurgical Quarterly》1993,82(1):119-121
Isolation of Salmonella from the feces of impounded dogs was carried out to make clear the recent microbiological condition of dogs introduced into our facilities. Salmonella was isolated from 10 out of 283 samples (3.5%). Inparticular, during the first week after introduction, Salmonella was isolated from nine out of 74 dogs (12.2%). The isolation rate during the first week after introduction was significantly higher than that for dogs introduced later. No isolates were detected from dogs reared for more than 3 weeks after introduction. This study indicates that impounded dogs had the highest risk of infecting a person with Salmonella during the first week after introduction into our laboratory animal facilities, and that we need to pay attention to this fact when handling them. 相似文献
9.
S Karacagil A Holmberg A Narbani I Eriksson D Bergqvist 《Canadian Metallurgical Quarterly》1996,12(3):337-341
Faecal samples from asymptomatic dairy cows and calves from a farm on the Island Falster, Denmark, were examined by a sucrose gradient flotation technique. Giardia cysts were found in 7.6% of the 92 samples, and estimated cyst excretion rates ranged from 50-200 cysts per gram faeces. Given that Giardia has the potential to cause clinical disease in cattle and to be transmitted to other animal species and humans, finding the parasite in cattle may be of major epidemiological significance. Future work should focus on elucidating the pathogenicity, transmission patterns and the genetic structure of Giardia populations in cattle in Denmark. 相似文献
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