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21.
To be able to perform more realistic simulations of timber constructions with modern numerical simulation methods like the finite element method (FEM), a suitable constitutive material model is required. Such a material model was developed by Mackenzie-Helnwein et al. (2005) for clear spruce wood. This paper presents an application-oriented adaption and usage of the mentioned material model, its implementation in a FE software as well as performing ultimate load analyses using FEM and the validation of the material model by means of the comparison of results of FE Simulations and experiments on the structure level (Fleischmann 2005). Further, some aspects with respect to the standardisation are discussed in one of the two examples.  相似文献   
22.
Polyglandular autoimmune syndrome (PGAS) type 2 (Schmidt syndrome) is characterized by the association of primary adrenocortical insufficiency with autoimmune thyroid disease, and/or insulin-dependent diabetes mellitus (IDDM). In this report we describe the occurrence of two episodes of post-partum thyroiditis (PPT) after a first and second pregnancy as well the development acutely of adrenal insufficiency after a second pregnancy. A family history of autoimmune thyroid disease and IDDM as well as positive antiadrenal and antithyroid antibodies and HLA typing is evidence for an underlying polyendocrine autoimmune syndrome. This case report provides further evidence that the immune system that is suppressed in pregnancy to tolerate the fetal allograft can rebound post-partum to unmask polyendocrine autoimmune disorders such as adrenalitis and PPT in susceptible women.  相似文献   
23.
The residential therapeutic caring community (RTCC) for adolescents combines psychotherapeutic principles of the professional model and self-help concept of the therapeutic community by using the collective resources of members to mobilize peer pressure. The RTCC is a safe, structured, supportive treatment environment that employs a confrontation, teaching, interpretative, and reasoning approach and uses the psychotherapeutic principles of reality therapy and existential thought. In the RTCC, the staff serve as mentors and role models, and they demonstrate their concern by maintaining high expectations for immediate improved behavior. The personal qualities necessary for a psychotherapist working in an RTCC are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
24.
Exploiting synergies afforded by a host of recently available national-scale data sets derived from interferometric synthetic aperture radar (InSAR) and passive optical remote sensing, this paper describes the development of a novel empirical approach for the provision of regional- to continental-scale estimates of vegetation canopy height. Supported by data from the 2000 Shuttle Radar Topography Mission (SRTM), the National Elevation Dataset (NED), the LANDFIRE project, and the National Land Cover Database (NLCD) 2001, this paper describes a data fusion and modeling strategy for developing the first-ever high-resolution map of canopy height for the conterminous U.S. The approach was tested as part of a prototype study spanning some 62,000 km2 in central Utah (NLCD mapping zone 16). A mapping strategy based on object-oriented image analysis and tree-based regression techniques is employed. Empirical model development is driven by a database of height metrics obtained from an extensive field plot network administered by the USDA Forest Service-Forest Inventory and Analysis (FIA) program. Based on data from 508 FIA field plots, an average absolute height error of 2.1 m (r = 0.88) was achieved for the prototype mapping zone.  相似文献   
25.
BACKGROUND/AIMS: To characterize the effects of endothelin-1 and of Bosentan, a mixed endothelin antagonist, on hepatic hemodynamics in cirrhotic animals in vivo and on hepatic microvascular exchange in the perfused rat liver. METHODS: Biliary cirrhosis was induced by bile duct ligation, and micronodular cirrhosis by chronic exposure to phenobarbital/CCl4 in male rats. Hepatic hemodynamics were studied under basal conditions and after administration of Bosentan (3-30 mg/kg) by the microsphere technique. Microvascular exchange was assessed in the in situ perfused rat liver by the multiple indicator dilution technique. RESULTS: Bosentan lowered portal pressure in a dose-dependent fashion; at the highest dose tested, this decrease averaged -29+/-11 and -26+/-8% in biliary and micronodular cirrhosis, respectively (p<0.01). This was achieved mainly via a marked decrease in hepatic arterial flow. In the perfused liver, endothelin-1 induced a dose-dependent vasoconstriction; up to 10(-9) mol/l; this was not associated with any effect on viability. At this dose, endothelin-1 markedly decreased extravascular albumin space in both controls and micronodular cirrhosis; this could be antagonized by Bosentan 10(-5) mol/l. CONCLUSIONS: Endothelin-1 affects hepatic microvascular exchange, presumably by a direct effect on hepatic sinusoidal endothelial cells. A mixed endothelin antagonist lowers portal pressure in vivo, presumably by acting on hepatic stellate cells, and counteracts the microvascular effects of endothelin-1 in vitro. These properties could prove useful in treatment of portal hypertension.  相似文献   
26.
A hyperdynamic circulatory state with elevated cardiac output, decreased peripheral vascular resistance, and sodium retention occurs in patients with portal cirrhosis. Surgical portal-systemic shunts and transjugular intrahepatic portal-systemic shunts (TIPS) have been shown to worsen the high-output state in these patients. However, clinical evidence of high-output congestive heart failure has been reported only rarely to complicate cirrhosis. We describe a patient who developed high-output congestive heart failure with markedly elevated filling pressures after TIPS and had complete resolution of heart failure after liver transplantation.  相似文献   
27.
    
Zusammenfassung Mittels verschiedener Untersuchungen wurden Aussagen über das Migrationsverhalten von Acetaldehyd aus Polyethylenterephthalat (PET) getroffen. Die Analyse des Acetaldehyds erfolgte durch Kopfraum-Gaschromatographie mit Flammenionisationsdetektion. Die Bestimmung des Restgehaltes an Acetaldehyd in neuen PET-Flaschen ergab Werte um 6,3 mg/kg, woraus sich eine maximal mögliche Migratmenge von etwa 200 (g/L errechnen läßt. Migrationsstudien bei verschiedenen Temperaturen zeigten die für das Verpakkungssystem typischen Zeitverläufe. Die Diffusion des Acetaldehyds aus dem Kunststoff erreichte bei einer Inkubationstemperatur von 40 °C nach ca. 4 Tagen ein konstantes Niveau, welches ca. 10% des ermittelten Restgehaltes an Acetaldehyd beträgt. Bei einer Temperaturerhöhung um 20 °C kam es zu einer Erhöhung dieses Niveaus auf das 5fache. Die Versuchsergebnisse der Bestimmung des Acetaldehyds in Getränken zeigte, daß in der Praxis nur mit einer geringen Migration zu rechnen ist, die bei den kohlensäurehaltigen Erfrischungsgetränken wegen des intensiven Eigengeschmacks ohne Belang ist. Eine Geschmacksbeeinträchtigung könnte sich höchstens bei Mineral- und Sodawässern ergeben, wenn diese längerfristig, wie sich aus den Migrationsstudien ableiten läßt, Temperaturen um 40 °C ausgesetzt werden.
Study of the migration of acetaldehyde from PET bottles into soft drinks containing carbonic acid
Summary The migration of acetaldehyde from polyethyleneterephthalate (PET) under various conditions was analysed by headspace gas chromatography and flame ionisation detection. The residual amounts of new PET bottles were about 6.3 mg/kg with a migration value of 200 g/1. On studying the migration at different temperatures and times, behaviour curves characteristic of packing materials made from plastics are obtaind. The amount of acetaldehyde diffusing from PET at a temperature of 40° C reached a constant level after 4 days which was about 10% of the residual value of acetaldehyde. On increasing the temperature by 20° C, this level was raised up to 50%. The results of the analysis of acetaldehyde in soft drinks containing carbonic acid show that the migration in fact is not sufficiently high to influence the taste of these soft drinks. A negative effect on the taste may be recognized with mineral waters and soda when they are exposed to higher temperatures (e.g. 40° C or more) over a longer period of time.
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28.
29.
Abstract. We propose the quasi‐maximum likelihood method to estimate the parameters of an RCA(1) process, i.e. a random coefficient autoregressive time series of order 1. The strong consistency and the asymptotic normality of the estimators are derived under optimal conditions.  相似文献   
30.
Different routes for immobilization of TiO2 on conducting substrates were compared to find active and stable photocatalysts, which could either be operated in open circuit (photocatalysis) or with applied electric potential (photoelectrocatalysis). The advantage of applying an electric potential was investigated. Polarization curves and photoelectrochemical degradation reactions served to characterize catalysts and to find a way of predicting the optimum synthesis conditions. The difference between front side (EE) and back side (SE) illumination is discussed as a function of layer thickness, as well as the influence of oxidizable substance concentration on photocurrents. Stability of catalysts was investigated in repetitive degradation experiments.  相似文献   
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