364 research outputs found

    Remarks on the phonology of a south-western Karaim translation of the latter prophets

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    The present paper focuses on the only available South-Western Karaim translation of the Latter Prophets, registered under the accession number ADub.III.83. Alongside a concise overview of the manuscript and its copyist, Jeshua Josef Mordkowicz, the paper offers a brief analysis of the Modern South-Western Karaim traits displayed in the language of the manuscript

    Sol-derived AuNi/MgAl2O4catalysts: Formation, structure and activityin dry reforming of methane

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    Ni nanoparticles doped with different amount of gold were supported on MgAl2O4by deposition fromaqueous metal sol producing a series of catalysts with different Au content. The sol procedure was allowedto obtain dispersed metal particles with different composition. The particle size and the particle compo-sition of the sol were maintained even after being deposited on the support. The catalysts, characterizedby several techniques such as TPR, XPS, XRD, TEM, HRTEM and EELS at the different stages of their lifeexhibited significant structural modification. In particular, thermal treatments in reducing and oxidizingenvironment produced NiAu alloy phases and NiO surface segregation, respectively. When testing formethane dry reforming with CO2in temperature ramped reaction, the monometallic nickel catalyst wasmore active at lower temperature whereas the bimetallic catalysts were more active at higher temper-ature. The presence of gold slightly affected the CO/H2ratio due to the occurrence of parallel reactionssuch as the reverse water gas shift reaction (RWGS). Both types of catalysts, monometallic and bimetallicones, deactivated a little with time but the degree of activity loss was not in straightforward relation withAu content due to the different effect of gold on the stability and on the amount of carbon formation.© 2013 Elsevier B.V. All rights reserved

    The effects of 3-nitropropionic acid on the behavior and cortical electrical activity of rats in acute administration

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    In this study, the acute effects of 3-nitropropionic acid was investigated on open field and startle behavior of rats, and on their cortical electrical activity. Spontaneous locomotor activity, acoustic startle response, and pre-pulse inhibition of acoustic startle were measured in male Wistar rats (10 weeks old, 180-200g body weight) after a single dose of 10 or 20 mg/kg i.p. 3-nitropropionic acid. After the behavioral tests, the rats were anaesthetized, and spontaneous cortical electrical activity was recorded. The vertical, horizontal and local open field performance showed dose-dependent deterioration in the rats treated with 3-nitropropionic acid. The number of “noise-positive” startle responses showed non-significant changes, but the inhibition by pre-pulse was significantly reduced in the high dose animals. High dose also increased the proportion of low-frequencies in the cortical activity. Three-nitropropionic acid, known primarily to act in repeated doses (e.g., in animal models of Huntington’s disease) had also some clear-cut acute effects on behavioral and electrophysiological parameters of the treated rats

    Az aszkorbinsav koncentráció és redox státusz szabályozása növényi sejtekben bioszintézis és intracelluláris transzport révén = The regulation of ascorbate concentration and redox state in plant cells via its biosynthesis and intracellular transport

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    Radioaktívan jelölt ligandok rapid filtrációja során specifikus glukóz és dehidroaszkorbát transzportot figyeltünk meg, növényi mitokondriumban. A mitokondriális légzés KCN-dal törtnő gátlása és a szétkapcsolószer 2,4-dinitrofenol nem befolyásolta a vizsgált transzportfolyamatokat. Az eredmények igazolják a mitokondriális dehidroaszkorbát és glukóz transzport meglétét, valamint azt valószínűsítik, hogy azonos, mindenesetre közeli rokonságban álló transzporterek (vagy transzportrendszerek) mediálják a két transzportfolyamatot. A mitokondrium dehidroaszkorbát redukciós képessége egyértelműnek bizonyult, továbbá jelentős aszkorbát szintet tudott fenntartani. Az inkubációs közeghez adott légzési szubsztrát szukcinát fokozta az aszkorbinsav keletkezését. A komplex I szubsztrát malát, valamint a komplex I inhibitor rotenon nem befolyásolta az aszkorbát képződést. Eredményeink összeségében arra utalnak, hogy a növényi mitokondrium légzési elektron transzfer lánca - közelebbről a II-es légzési komplex - fontos szerepet játszik a dehidroaszkorbát mitokondriális redukciójában. Kísérleteink során inveráz aktivitást találtunk frissen izolált csicsóka mitokondrium mátrix alfrakciójában. Az enzimaktivitás pH optimuma, kinetikai paraméterei, valamint inhibitor profilja alapján az újonnan leírásra került enzim a neutrális invertázok családjába sorolható. Az enzimaktivitáson felül kimutattuk szubsztrátjának, valamint termékeinek mitokondriális belső membránon keresztüli transzportját. | Ascorbate, dehydroascorbate (DHA), and glucose transport was investigated in plant mitochondria prepared from cultured BY2 tobacco cells. Using a rapid filtration method, we observed a specific glucose and dehydroascorbate transport, which was temperature and time dependent and saturable. Inhibition of mitochondrial respiration by KCN and the uncoupler 2,4-DNP did not influence the transport of the investigated compounds. The results demonstrate the presence of dehydroascorbate and glucose transport in plant mitochondria and suggest that it is mediated by the same or closely related transporter(s). Mitochondria showed clear ability to reduce DHA and to maintain a significant level of ascorbate. Ascorbate generation could be stimulated by the respiratory substrate succinate. The complex I substrate malate and the complex I inhibitor rotenone had no effect on the ascorbate generation from DHA. These results together suggest that the mitochondrial respiratory chain of plant cells - presumably complex II - plays important role in the regeneration of ascorbate from its oxidized form, DHA. Invertase activity in the mitochondrial matrix of Helianthus tuberosus tubers was demonstrated. The pH optimum, the kinetic parameters and the inhibitor profile of the invertase activity indicated that it belongs to the neutral invertases. In accordance with this topology, transport activities responsible for the mediation of influx/efflux of substrate/products were shown and characterized

    Altered open field behavior in rats induced by acute administration of 3-nitropropionic acid: possible glutamatergic and dopaminergic involvement

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    3-nitropropionic acid (3-NP), a substance used for modelling Huntington’s disease, was given to male Wistar rats once in 20 mg/kg b.w. dose, and the resulting behavioural alterations in spontaneous locomotor activity were measured after 30 minutes. To detect the involvement of neurotransmitter systems in this immediate effect, the NMDA antagonist MK-801 (0.8 mg/kg); as well as an agonist, quinpirole (QP, 5 mg/kg) and an antagonist, sulpiride (SP, 80 mg/kg) of the dopamine D2 receptors, were given before 3-NP to separate groups of rats. Controls were given saline. All substances were injected ip. 3-NP decreased the rats’ locomotor, especially vertical, activity, whereas local activity was increased. Based on the further changes of 3-NP effects in the combination groups it could be concluded that dopaminergic rather than glutamatergic mechanisms were possibly involved in the acute behavioural effect of 3-NP

    Optogenetics : past, present and future

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    The term ‘optogenetics’ was introduced into the scientific literature less than a decade ago by Karl Deisseroth, developer of pioneering optogenetic techniques, who defined optogenetics as “the combination of genetic and optical methods to achieve gain or loss of function of well-defined events in specific cells of living tissue”. Since then this new field of biology has become a very exciting and rapidly developing area producing hundreds of scientific publications. New methods and tools have been developed and long-sought answers found in these new experimental systems. Discussion and full elaboration of every optogenetic approach and application are beyond the scope of this review, instead, it gives a short insight to (i) how light can be used to manipulate the membrane potential of various cells; (ii) how light-sensitive proteins can be used to regulate targeted gene expression, and (iii) how controlled release or spatio-temporal targeting of certain molecules can be modulated by light. Besides, the most widely used light-sensor proteins, including their structure, working mechanism and their involvement in existing optogenetic applications are also discussed
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