Effects of triiodothyronine in spontaneously hypertensive rats. Studies on cardiac metabolism, function, and heart weight

We have studied the effects of triiodothyronine (T3) on heart function, on the myocardial oxidative pentose phosphate pathway, and on heart weight in spontaneously hypertensive (SHR) rats. Another aim was to examine whether these T3-effects may be reversible. T3 was administered daily (0.2 mg/kg s.c.) for 14 days. Compared to the untreated SHR controls, T3 induced an increase in heart rate (beats/min) from 357 +/- 10 (n = 17) to 553 +/- 10 (n = 17), in the pressure-rate-product (mm Hg/min) from 78 400 +/- 4500 (n = 15) to 113 700 +/- 4800 (n = 15), and in the heart weight/body weight ratio (mg/g) from 4.2 +/- 0.2 (n = 20) to 5.8 +/- 0.2 (n = 19). The activity of myocardial glucose-6-phosphate dehydrogenase, the first and rate-limiting enzyme of the oxidative pentose phosphate pathway (units/g protein), was elevated from 4.2 +/- 0.2 (n = 9) to 7.0 +/- 0.6 (n = 9) after 14 days of T3-treatment, while the activity of 6-phosphogluconate dehydrogenase, one of the following enzymes in the pathway, was not altered appreciably. These changes returned to the respective control values when T3-treatment was discontinued for 14 days. Our results demonstrate that T3 had a positive chronotropic effect and induced an additional heart enlargement in an animal model with already established cardiac hyperfunction and hypertrophy. The effects on heart function and weight, which were fully reversible, were not as pronounced as in normal Sprague-Dawley rats.     

The influence of processor architecture on the design and the results of WCET tools

The architecture of tools for the determination of worst case execution times (WCETs) as well as the precision of the results of WCET analyses strongly depend on the architecture of the employed processor. The cache replacement strategy influences the results of cache behavior prediction; out-of-order execution and control speculation introduce interferences between processor components, e.g., caches, pipelines, and branch prediction units. These interferences forbid modular designs of WCET tools, which would execute the subtasks of WCET analysis consecutively. Instead, complex integrated designs are needed, resulting in high demand for memory space and analysis time. We have implemented WCET tools for a series of increasingly complex processors: SuperSPARC, Motorola ColdFire 5307, and Motorola PowerPC 755. In this paper, we describe the designs of these tools, report our results and the lessons learned, and give some advice as to the predictability of processor architectures.     

Life stage specific impact of dimethoate on the predatory mite Hypoaspis aculeifer canestrini (Gamasida: Laelapidae)

Toxicants may affect juveniles more than adults because of physiological and behavioral aspects. When developing toxicity tests, this issue is often not addressed, and the most sensitive end point may be ignored. The topic was raised by a European working group aiming to develop a standard toxicity test with the predatory mite, Hypoaspis (Geolaelaps) aculeifer Canestrini, as this species was included in the EU Guidance documentfortesting of pesticides. To assess whether the juvenile life stages are the most susceptible, we examined the acute toxicity of dimethoate on larvae, protonymphs, deutonymphs, males, and females of H. aculeifer. The mites were exposed to 0, 2, 4, and 6 mg dimethoate kg(-1) for 7 days in an OECD artificial soil (5% organic matter). Total juvenile biomass, reproduction, mortality, and population growth rate (pgr) lambda were assessed at the end of the test. A comparison of mortality ranked the sensitivity of the life stages: Larvae (LC50 = 3.8 mg kg(-1)) > protonymphs (LC50 = 5.3 mg kg(-1)) > males (LC50 = 5.6 mg kg(-1)) > deutonymphs (LC50 = 7.1 mg kg(-1)) > females (LC50 = 7.6 mg kg(-1)). Effects on reproduction and pgr were significant at 2 mg dimethoate kg(-1), with population decline starting at this concentration. Thus, a test system with H. aculeifer including reproduction as end point is a rational approach, as reproduction will encompass juvenile mortality, at least with respect to dimethoate. Moreover, we suggest that pgr should be included in chronic standard tests because of high ecological relevance and the feasibility of applying it.     

Die Verbesserung der Destillation durch hybride Systeme

The application efficient membranes make it energy‐economic useful to connect the vaporpermeation and rectification for dehydration ethanol. Good vacuum‐conditions are premise for necessary permeat‐flow. Microfiltration and reversosmosis optimize additional processparameters and enable a wastwaterfree operation. With large capacity dehydrated ethanol is a competitive fuel‐additiv.     

New Adhesion Promoters for Copper Leadframes and Epoxy Resin

New primer molecules have been synthesized to increase the adhesion strength between a copper leadframe and an epoxy molding compound in microelectronical devices. The coupling agents were preliminarily chemisorbed at the surface of copper plates via special binding groups like thiol, disulfide, ethylene diamine and phthalocyanine. Binding to the epoxy resin was performed via an hydroxyl group. Linear hydrocarbon spacers with various chain lengths connected the copper- and epoxy-binding groups. The self-assembled layers of the organic coupling agents at the metal surface were characterized by X-ray photoelectron spectroscopy. Thermogravimetric analysis was used to study the coating with respect to its corrosion oxidation inhibition. Shear tests clearly indicated that the coupling agents increase adhesion strength and are stable even in extreme humidity and thermal conditions in analogy to IPC-Level-1 pretreatment. Thus, delamination of the microelectronical packages was prevented.     

New Adhesion Promoters for Copper Leadframes and Epoxy Resin

New primer molecules have been synthesized to increase the adhesion strength between a copper leadframe and an epoxy molding compound in microelectronical devices. The coupling agents were preliminarily chemisorbed at the surface of copper plates via special binding groups like thiol, disulfide, ethylene diamine and phthalocyanine. Binding to the epoxy resin was performed via an hydroxyl group. Linear hydrocarbon spacers with various chain lengths connected the copper- and epoxy-binding groups. The self-assembled layers of the organic coupling agents at the metal surface were characterized by X-ray photoelectron spectroscopy. Thermogravimetric analysis was used to study the coating with respect to its corrosion oxidation inhibition. Shear tests clearly indicated that the coupling agents increase adhesion strength and are stable even in extreme humidity and thermal conditions in analogy to IPC-Level-1 pretreatment. Thus, delamination of the microelectronical packages was prevented.     

Release of Soybean Isoflavones by Using a β-Glucosidase from Alicyclobacillus herbarius

β-Glucosidases are used in the food industry to hydrolyse glycosidic bonds in complex sugars, with enzymes sourced from extremophiles better able to tolerate the process conditions. In this work, a novel β-glycosidase from the acidophilic organism Alicyclobacillus herbarius was cloned and heterologously expressed in Escherichia coli BL21(DE3). AheGH1 was stable over a broad range of pH values (5–11) and temperatures (4–55 °C). The enzyme exhibited excellent tolerance to fructose and good tolerance to glucose, retaining 65 % activity in the presence of 10 % (w/v) glucose. It also tolerated organic solvents, some of which appeared to have a stimulating effect, in particular ethanol with a 1.7-fold increase in activity at 10 % (v/v). The enzyme was then applied for the cleavage of isoflavone from isoflavone glucosides in an ethanolic extract of soy flour, to produce soy isoflavones, which constitute a valuable food supplement, full conversion was achieved within 15 min at 30 °C.