Thermo-regulatory responses to hypothalamic heating in dehydrated rabbits

Résumé Chez les lapins déshydratés par privation d'eau pendant 3 jours, on constate la disparition de la polypnée produite par la stimulation thermique de l'hypothalame antérieur, tandis que la réaction vasodilatatrice cutanée est conservée.     

The influence of habitat features on amphibian distribution in Northeastern Greece

Environmental and isolation variables relating to abundance of breeding amphibians, species richness and community structure at different spatial scales were examined in the Dadia-Lefkimi-Soufli Forest National Park, Evros, Greece. Logistic regression and a generalized linear model were used to relate several habitat characteristics to species occurrence and species richness. The community structure responses to breeding-pond features were examined at four spatial scales using canonical correspondence analysis (CCA). The richest communities live in low-altitude ponds, with stony or clay bottoms, high solar exposure and abundant submerged and floating vegetation. The CCA models were significant (p < 0.005) and revealed the influence of altitude, percentage of field and broadleaf forest coverage, and number of water bodies on amphibian species assemblages at all four spatial scales. There is a specific need for holistic management of amphibians that will consider habitat connectivity, particularly between aquatic and terrestrial habitats, at a larger, more interconnected scale.     

Hybrid aqueous capacitors with improved energy/power performance

This work reports on a high-voltage, hybrid capacitor involving two separate redox reactions. Aqueous solutions of Mg(NO3)2 and KI have been used for negative and positive electrode, respectively. Adjusting pH=2 for electrode (+) with KI solution and modifying Mg(NO3)2 solution to pH=9 for negative side play a crucial role for a stable long-term operation of capacitor at enhanced voltage. A benefit from such a construction is a pseudocapacitive contribution from hydrogen sorption reaction on the negative electrode and high iodine/iodide activity on the positive electrode, enhancing the energy with no remarkable impact on the power profile. Proposed solution allows a high voltage (1.8 V) to be reached and thereby high power and energy performance (~20 W h/kg at 1 kW/kg) to be obtained. High long-term stability has been confirmed by floating and galvanostatic tests.     

The role of neuraminic acid in the stability and enzymic activity of acid phosphatase of the human prostate gland

Résumé On a comparé certaines propriétés physicochimiques et enzymatiques de la phosphomonoestérase acide native de la prostate de l'homme à celle traitée par la neuraminidase. L'enzyme dépourvue d'acide neuraminique atteint son optimum à un pH élevé, elle présente une plus grande affinité avec certains substrats et est inhibé d'une manière plus intense par lel(+)-tartrate que la phosphomonoestérase native.     

Non-steroidal anti-inflammatory drugs: Effects on the utilization of glucose and production of lactic acid in tissue culture

Zusammenfassung In der Kultur embryonalen Hühnchengewebes kommt es unter Einfluss nichtsteroider Antiphlogistica (Aspirin, Indomethacin, Mefenamicsäure) zu einer Steigerung des Glukoseverbrauchs bei gleichzeitiger Vermehrung der Milchsäureerzeugung. Der Milchsäureverbrauch verläuft in zwei Phasen, wobei der erste Gipfel bei geringsten Konzentrationen des Arzneimittels.auftritt.     

tRNA structural and functional changes induced by oxidative stress

Oxidatively damaged biomolecules impair cellular functions and contribute to the pathology of a variety of diseases. RNA is also attacked by reactive oxygen species, and oxidized RNA is increasingly recognized as an important contributor to neurodegenerative complications in humans. Recently, evidence has accumulated supporting the notion that tRNA is involved in cellular responses to various stress conditions. This review focuses on the intriguing consequences of oxidative modification of tRNA at the structural and functional level.     

Neurosecretion in Ehrlich ascites carcinoma-bearing mice

Zusammenfassung Karyometrische Untersuchungen am Nucleus supraopticus von Mäusen des Stammes C57Bl, die Träger des Ehrlich-Ascites-Tumors sind, zeigen eine statistisch gesicherte Zunahme der Zellkernvolumina im Vergleich zu gesunden Kontrolltieren.