The effect of severe hypoxic hypoxia in the decompression chamber on the catecholamine content of the hypothalamus in the cat

Résumé La quantité de la noradrénaline dans l'hypothalamus de chat exposé a l'hypoxie grave dans la chambre de décompression fut diminuée significativement.     

Effects of thalamic stimulation upon the rate,duration and synchronization of clonic activity of the two independent cortical foci

Résumé Par la stimulation électrique adéquate des noyaux thalamiques intralaminaires (N. anterior, N. medialis dorsalis) chez les singes non anesthésiés portant les électrodes à demeure, il a été possible de contrôler le rythme des décharges cloniques de deux foyers corticaux indépendants, de synchroniser leur activité et de prolonger la séquence clonique des décharges dépassant sa durée intrinsèque.     

Studies on the ascorbic acid and carotene content in leaves as a common characteristic of botanically related species

Résumé Les résultats des dosages parallèles d'acide ascorbique et de carotène dans les feuilles des espèces appartenant à 7 familles ont démontré une tendance à la stabilité de la proportion acide ascorbique/carotène chez les plantes apparentées. La stabilité de cette proportion chez les espèces d'une seule famille est plus marquée que celle de la teneur même des deux substances. Ce fait semble pouvoir confirmer l'idée d'une correlation étroite dans l'action des deux substances en question.     

Hidden magnetic excitation in the pseudogap phase of a high-T(c) superconductor

The elucidation of the pseudogap phenomenon of the high-transition-temperature (high-T(c)) copper oxides-a set of anomalous physical properties below the characteristic temperature T* and above T(c)-has been a major challenge in condensed matter physics for the past two decades. Following initial indications of broken time-reversal symmetry in photoemission experiments, recent polarized neutron diffraction work demonstrated the universal existence of an unusual magnetic order below T* (refs 3, 4). These findings have the profound implication that the pseudogap regime constitutes a genuine new phase of matter rather than a mere crossover phenomenon. They are furthermore consistent with a particular type of order involving circulating orbital currents, and with the notion that the phase diagram is controlled by a quantum critical point. Here we report inelastic neutron scattering results for HgBa(2)CuO(4+δ) that reveal a fundamental collective magnetic mode associated with the unusual order, and which further support this picture. The mode's intensity rises below the same temperature T* and its dispersion is weak, as expected for an Ising-like order parameter. Its energy of 52-56?meV renders it a new candidate for the hitherto unexplained ubiquitous electron-boson coupling features observed in spectroscopic studies.     

Unusual magnetic order in the pseudogap region of the superconductor HgBa2CuO4+delta

The pseudogap region of the phase diagram is an important unsolved puzzle in the field of high-transition-temperature (high-T(c)) superconductivity, characterized by anomalous physical properties. There are open questions about the number of distinct phases and the possible presence of a quantum-critical point underneath the superconducting dome. The picture has remained unclear because there has not been conclusive evidence for a new type of order. Neutron scattering measurements for YBa(2)Cu(3)O(6+delta) (YBCO) resulted in contradictory claims of no and weak magnetic order, and the interpretation of muon spin relaxation measurements on YBCO and of circularly polarized photoemission experiments on Bi(2)Sr(2)CaCu(2)O(8+delta)(refs 12, 13) has been controversial. Here we use polarized neutron diffraction to demonstrate for the model superconductor HgBa(2)CuO(4+delta) (Hg1201) that the characteristic temperature T* marks the onset of an unusual magnetic order. Together with recent results for YBCO, this observation constitutes a demonstration of the universal existence of such a state. The findings appear to rule out theories that regard T* as a crossover temperature rather than a phase transition temperature. Instead, they are consistent with a variant of previously proposed charge-current-loop order that involves apical oxygen orbitals, and with the notion that many of the unusual properties arise from the presence of a quantum-critical point.     

皮秒Nd:YAG激光对生物金属纯Ti和Ti–13Nb–13Zr合金的表面改性

The effects of picosecond Nd:YAG laser irradiation on chemical and morphological surface characteristics of the commercially pure titanium and Ti–13Nb–13Zr alloy in air and argon atmospheres were studied under different laser output energy values. During the interaction of laser irradiation with the investigated materials, a part of the energy was absorbed on the target surface, influencing surface modifications. Laser beam interaction with the target surface resulted in various morphological alterations, resulting in crater formation and the presence of microcracks and hydrodynamic structures. Moreover, different chemical changes were induced on the target materials’ surfaces, resulting in the titanium oxide formation in the irradiation-affected area and consequently increasing the irradiation energy absorption. Given the high energy absorption at the site of interaction, the dimensions of the surface damaged area increased. Consequently, surface roughness increased. The appearance of surface oxides also led to the increased material hardness in the surface-modified area. Observed chemical and morphological changes were pronounced after laser irradiation of the Ti–13Nb–13Zr alloy surface.     

5-(Hydroxyimino)-4-methoxy-2-(pivaloylimino)thiazolidine-3-acetamide,a reduced nitroheterocyclic derivative with potent schistosomicidal properties

Summary The synthesis and antischistosome properties of 5-(hydroxyimino)-4-methoxy-2-(pivaloylimino)thiazolidine-3-acetamide (1) are described. The compound was prepared by reduction of the nitrothiazoline (2) with stannous chloride in methanol, and represents the first example of a reduced nitroheterocyclic compound showing potent schistosomicidal properties. The possible relationship of compounds such as1 to the as yet unidentified reduced active but toxic entities formed in vivo from nitroheterocyclics like metronidazole is discussed.Acknowledgments. The authors are grateful to Dr A. J. Everett and his staff for the physical chemistry measurements, and to Mr G. Dickerson for the antischistosome testing.     

Regional distribution of adenine nucleotides,glycogen, glucose and lactate in the adult rat brain

Résumé Le cervelet contient des quantités plus grandes d'ATP, d'ADP et de nucléotides totaux que le lobe frontal du cerveau ou la moelle cervicale. Ces différences ne sont pas trouvées avec l'AMP. Le contenu en glycogène, en glucose et en lactate est plus grand dans la moelle cervicale que dans le cervelet et dans le lobe frontal.

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We wish to thank Dr.H. Rehkämper from Boehringer Mannheim GmbH, who kindly supplied us with all the enzymes, substrates and cofactors.     

Effect of Ftorafur on acid phosphatase activity in the liver of mice with transplanted lymphatic leukaemia

Zusammenfassung Nachweis, dass Ftorafur, N₁-(2-Furanidyl)-5-Fluorouracil das Überleben leukämischer Mäuse deutlich steigert und ausserdem als Lysosomen-Stabilisator wirken könnte, wobei die in vivo Stabilisierung der Lysosomen den antileukämischen Effekt dieses Zytostatikums unterstützen könnte.