Effects of beta blockade with metoprolol on simple and complex task performance.

[Correction Notice: An erratum for this article was reported in Vol 8(5) of Health Psychology (see record 2008-09113-001). The reference and citations for Merrill, Robbins, Schultz, Streeten, and Elias (1987) were incorrect. The correct reference is: Elias, M. F., Robbins, M. A., Schultz, N. R., Streeten, D. H. P., & Elias, P. K. (1987). Clinical significance of cognitive performance by hypertensive patients. Hypertension, 9, 192-197.] Measured the effect of treatment with the beta-blocker metoprolol on several indicants of task performance in 25 mildly to moderately hypertensive men (aged 24–63 yrs) treated for 2 wks each with drug and placebo, compared with 25 untreated normotensive men (aged 23–64 yrs). Ss responded twice to the Mood Adjective Check List (MACL) and the Stroop Color and Word Test. In addition, Ss participated in 2 parallel decision-making simulations. Results indicate that normotensives and hypertensives on drug or placebo did not differ on MACL and Stroop scores. Comparisons on 12 validated simulation measures showed that treatment with metoprolol aided complex task performance. Treatment improved strategic capacity and the ability to deal effectively with emergencies. Preliminary evidence that treatment with metoprolol might help restore performance capacity that may have been lost due to hypertensive disease was also obtained. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The use of statistical properties of transmission signals for particle characterization

The measurement of transmission is an often used measuring principle in technology. The evaluation algorithms of fluctuating transmission signals are well known in the case of single particle measurement. By evaluating fluctuating transmission signals the particle characterization is also possible at high particle concentrations (0.01 to 30 vol.-%). In comparison with conventional photometers a significant gain of information can be received. Fluctuating signals are caused by the statistical probability of a limited number of particles being present in a defined measuring volume. The evaluation of such signals allows the determination of particle concentration, particle size of monodisperse particles (extinction diameter) and information about structure of agglomerates independent from each other. Mathematical fundamentals and practical ways to measure these parameters are shown. Experimental results are examplarily presented for monodisperse, polydisperse and agglomerated suspensions.     

INFLUENCE OF INTERFACIAL TENSION AND VISCOSITY ON THE BEHAVIOR OF A PACKED COLUMN IN NEAR-CRITICAL FLUID EXTRACTION

Density and viscosity of the coexisting phases and interfacial tension of the following binary systems were measured: pelargonic acid, linoleic acid, oleic acid or stearic acid as subcritical and carbon dioxide as superecritical components. Also the corresponding phase equilibria were investigated at pressures ranging from 2 to 20 MPa and temperatures from 313 K to 393 K. With increasing pressure the concentration of the supercritical component in the liquid phase increases and viscosity and liquid interfacial tension decreases. At greater activities of the dense gases the interfacial tension decreases dramatically to values less than 2 mN/m. If the pressure exceeds a certain limit, a falling film disintegrates into small droplets. The surface excess passes through a maximum at these conditions. At first appearance of instabilities on a falling film, the logarithm of the Reynolds number is a linear function of the logarithm of the film number. Independent of the type of the investigated packings, the number of theoretical stages per meter versus Hodenstein number fall all on the same curve when an extraction is carried out in the droplet regime. Also the logarithm of the capacity of a column al the flooding point versus the logarithm of the density difference between the coexisting phases is a linear function when an extraction is carried out in the droplet regime.     

Untersuchungen zum Langzeiteinsatz der In-situ-Aktivkohlefiltration zur Entfernung von organischen Schadstoffen aus Grundwasser

Long-term in-situ removal of organic contaminants using activated carbon was investigated within the framework of the SAFIRA-Project. Common problems are plugging and chemo- or biofouling, which can reduce the sorption capacity or permeability of the activated carbon filter. The tests involved three different types of granular activated carbon (TL 830, INP Reac, both from Chemviron and ROW 0.8 supra, from Norit). The groundwater predominately contaminated with monochlorobenzene (MCB) was treated successfully and efficient over a time period of two years by the activated carbon filtration. In none of the in-situ operated activated carbon filters plugging, chemo- or biofouling was observed, which is believed to be due to the strategy of keeping the natural groundwater chemistry stable. The loading of the activated carbon with the contaminants agreed very well with expectations from modeling (PSDM). The results of this long term investigation demonstrate, that in-situ activated carbon filtration is a very successful method to remove hydrophobic contaminants from groundwater without bio- or chemofouling.     

Characterization of thin-film losses with a synchronously pumped ringdown cavity

We describe the use of a synchronously pumped ringdown cavity for measuring total optical losses, absorption and scattering, in thin optical films of arbitrary thickness on transparent substrates. This technique is compared with a single-pulse ringdown cavity regime and is shown to have a superior signal-to-noise ratio and resolution. We also provide an analysis of the factors affecting the resolution of the technique. Using this ringdown cavity pumped by a conventional mode-locked Ti:sapphire laser, we experimentally detect losses of only 58 +/- 9 and 112 +/- 9 parts per million in Ta2O5 and SiO2 films, respectively. To our knowledge, these are so far the lowest losses measured in thin films on stand-alone transparent substrates.     

Austenite grain development during reheating of microalloyed plate steels

The influence of various reheating temperatures and times on austenite grain growth and dissolution behaviour of precipitates was investigated in three different microalloyed steels. The characteristics of these steels were compared with those of a non-microalloyed steel of similar basic composition. Then, the interrelationships between precipitate distribution, precipitate dissolution and austenite grain growth were discussed.     

Einflu? des Blanchierens sowie der Konservierung durch Lufttrocknung bei verschiedenen Temperaturen, Tiefgefrieren und Gefriertrocknung auf den Oxals?uregehalt von Spinat

Zusammenfassung Gleiche Teile einer Spinatprobe von 12,5 kg wurden unblanchiert, dampfblanchiert und wasserblanchiert weiterbehandelt. Ein Teil einer jeden Probe blieb unbehandelt, weitere wurden bei 30, 70 und 105° C luftgetrocknet, tiefgefroren und gefriergetrocknet. In aliquoten Teilen dieser 18 unterschiedlich behandelten Proben wurde der Gehalt an wasserlöslicher und unlöslicher Oxalsäure bestimmt. Daraus wurde der Gehalt an Gesamt-Oxalsäure berechnet, der außerdem nach der Methode von Lehmann u. Grütz ermittelt wurde. Nach derselben Methode wurden auch Blanchier- und Abschreckwasser und das Sediment des Blanchierwassers untersucht.Es zeigt sich, daß nur durch das Blanchieren der Gehalt an löslicher und Gesamt-Oxalsäure signifikant herabgesetzt wird. Dieses geschieht durch Überführung wasserlöslicher Oxalate in unlösliches Caleiumoxalat und durch Auswaschung wasserlöslicher Oxalate. Beide Effekte sind beim Wasserblanchieren größer als beim Dampfblanchieren, so daß der mit Wasser blanchierte Spinat die niedrigsten Gehalte an physiologisch wirksamer Oxalsäure aufweist. Durch das Dampfblanchieren sind etwa 20% des im Spinat vorhandenen Calciums gebunden worden, das somit der Resorption entzogen wird. Ernährungsphysiologische Aspekte des Einflusses von Wasserund Dampfblanchieren auf die Qualität des Spinates werden diskutiert.

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Influence of blanching and conservation by air-drying at different temperatures, deep-freezing and freeze-drying on oxalic acid of spinach

Summary Equal parts of a sample of 12,5 kg spinach were used for further treatment unblanched, blanched with steam and with water. One part of each of these samples remained without further treatment, others were air-dried at 30° C, 70° C and 105° C, frozen and freeze-dried, thus resulting 18 samples. In aliquotes of these differently treated samples the content of water soluble and insoluble oxalic acid was determined. From the obtained results the total content of oxalic acid was calculated. Besides this the total content of oxalic acid was also determined according to the method of Lehmann and Grütz. The water used for blanching, the sediment formed in the water, and the water used for chilling the blanched spinach were analyzed for total oxalic acid content according to the same method.The results of these experiments show that only blanching reduced significantly the content in soluble and total oxalic acid of the spinach. This is accomplished by the transfer of water soluble oxalates into insoluble calciumoxalate and by leaching of water soluble oxalates. Both these effects are higher for blanching with water than for blanching with steam, thus resulting in lower contents of physiological active oxalic acid in water blanched spinach. When blanching with steam about 20 per cent of the calcium present in the spinach is transfered into insoluble calciumoxalate. In this form the calcium can not be resorbed intestinally. Nutritional physiological aspects of the influence of blanching with water and with steam on the quality of spinach are discussed.

     

Long-term analgesic reaction in attacked mice.

Four experiments were designed to characterize long-term analgesic (LTA) reaction in attacked mice. In Experiment 1 we showed that analgesic reaction in DBA/2 mice, induced by the stress of being attacked (30 or 50 bites), is reinstated upon reexposure to seven bites 24 hr later. The magnitude of the LTA response depended on the level of analgesia on Day 1 and was smaller than the original response. In Experiment 2 we showed that LTA was prevented by naloxone or beta-chlornaltrexamine given before exposure (50 bites) on Day 1. Results of Experiment 3 revealed that naloxone or beta-chlornaltrexamine injected before reexposure to seven bites on Day 2 antagonized LTA measured 10 min, but not 1 min, after reexposure. In Experiment 4 we showed that morphine substituted for being attacked on Day 1 failed to produce LTA. We concluded that pain inhibitory mechanisms remain in a state of increased readiness for at least 24 hr after attack stress and that activation of opioid systems is necessary but not sufficient to produce LTA, a response that is only partly sensitive to opioid antagonists. (PsycINFO Database Record (c) 2010 APA, all rights reserved)