15,339 research outputs found
High current lightning test of space shuttle external tank lightning protection system
During lift-off, the shuttle launch vehicle (external tank, solid rocket booster and orbiter) may be subjected to a lightning strike. Tests of a proposed lightning protection method for the external tank and development materials which were subjected to simulated lightning strikes are described. Results show that certain of the high resistant paint strips performed remarkably well in diverting the 50 kA lightning strikes
Conversion efficiency and luminosity for gamma-proton colliders based on the LHC-CLIC or LHC-ILC QCD Explorer scheme
Gamma-proton collisions allow unprecedented investigations of the low x and
high regions in quantum chromodynamics. In this paper, we investigate
the luminosity for "ILC"LHC ( TeV) and
"CLIC"LHC ( TeV) based colliders. Also
we determine the laser properties required for high conversion efficiency.Comment: 16, 6 figure
An approach to metal fatigue
Cumulative fatigue damage based on investigation of fatigue limit associated with crack, crack propagation rate, and stress interaction cycle in metal
Nonhypnotic low-dose etomidate for rapid correction of hypercortisolaemia in cushing's syndrome
We determined the adrenostatic potential of low-dose nonhypnotic etomidate in six patients with Cushing's syndrome (ectopic Cushing's syndrome,n=2; Cushing's disease,n=3; bilateral adrenal adenoma,n=1). Etomidate was given as a continuous infusion for 32 h in a dose of 2.5 mg/h (n=5) or 0.3 mg/kg/h (n=3), respectively. Saline was given during a control period. The responsiveness to exogenous ACTH was studied during placebo and 7 and 31 h after commencing etomidate by administration of 250 µg 1–24 ACTH i.v. Etomidate (2.5 mg/h) led to a consistent decrease in serum cortisol in all patients from a mean of 39.4±13.3 to 21.1±5.7 µg/dl after 7 h (P<0.05 compared with placebo). After 24 h cortisol was reduced further to a mean steady state concentration of 12.3±5.7 µg/dl (P<0.05). At the end of the infusion period the cortisol increase in response to ACTH was reduced but not abolished. In contrast, a dose of 0.3 mg/kg/h etomidate induced unresponsiveness of serum cortisol to exogenous ACTH within 7 h. However, sedation was observed in two out of three patients at this dose, while during etomidate in a dose of 2.5 mg/h no side effects were seen. We conclude that low-dose non-hypnotic etomidate reduces serum cortisol to within the normal range in patients with Cushing's syndrome. The possibility to dissociate the adrenostatic effect of etomidate from its hypnotic action, the absence of side effects, and the i.v. route suggest that etomidate in a dose of 0.04–0.05 mg/kg/h may become the drug of choice for rapid initial control of hypercortisolism
Dentinogenesis imperfecta
Zusammenfassung: Unter Dentinogenesis imperfecta versteht man eine kongenitale Dysplasie des Dentins, die isoliert oder im Zusammenhang mit einer hereditären Allgemeinerkrankung wie der Osteogenesis imperfecta auftreten kann. Sie wird meist autosomal dominant vererbt und manifestiert sich klinisch in einer opaleszierenden Goldbraun- oder Graublauverfärbung der Zähne beider Dentitionen in variabler Ausprägung. Die verschiedenen Varianten der Dentinogenesis imperfecta werden nach Shields et al. (1973) in 3Gruppen eingeteilt: TypI, assoziiert mit Osteogenesis imperfecta; TypII, hereditär opaleszierendes Dentin; TypIII, Brandywine-Typ. Die Phänotypen der Dentinogenesis imperfecta werden in dem vorliegenden Beitrag hinsichtlich Gendefekt, klinischer Symptomatik, Radiologie und Histopathologie beschrieben, die zahnärztliche Behandlungsstrategie wird dargestell
Breeding of resistant strawberry cultivars for organic fruit production – Diallel crossing strategies and resistance tests for Botrytis cinerea and Xanthomonas fragariae
Organic strawberry production suffers from high yield losses caused by numerous fungal and bacterial diseases. Two of the most important diseases are the grey mould disease caused by Botrytis cinerea Pers. (teleomorph Botryotinia fuckeliana), and the bacterial angular leaf spot disease caused by Xanthomonas fragariae (Kennedy & King). Beside cultivation methods and organic plant protection measures, the development of resistant cultivars seems to be the most promising strategy in order to improve the productivity in organic strawberry cultivation. Therefore, we established resistance tests to determine resistant and susceptible strawberry cultivars and breeding selections. In a first run, 40 different cultivars and selections were tested for their susceptibility towards B. cinerea by artificial inoculation of fruits and leaves and evaluation of the disease symptoms. Plants of 40 cultivars were tested for susceptibility to X. fragariae by artificial inoculation in the greenhouse. In a diallel crossing approach, 12 commonly cultivated strawberry cultivars have been crossed reciprocally and propagated in a field trial. Important characteristics of the progeny such as ripening time, yield, morphological traits and occurrence of diseases have been evaluated for a period of two consecutive years and lead to the determination of general (GCA) and specific (SCA) combining abilities. Together with the results of the resistance tests we identified a set of genotypes that show resistant characteristics towards B. cinerea and might be suitable for use in organic cultivation systems. Furthermore, they can be used for targeted breeding experiments in the future
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