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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of organic chemistry 26 (1961), S. 1050-1052 
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 45 (1989), S. 126-129 
    ISSN: 1420-9071
    Keywords: L-gulono-γ-lactone oxidase ; ascorbic acid deficiency ; enzyme defect ; rat ; nuclei acid hybridization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A mutant strain of Wistar rats with L-gulono-γ-lactone oxidase deficiency has recently been established. To investigate this deficiency by DNA and RNA blot hybridization analyses, a fragment of a previously cloned cDNA encoding rat L-gulono-γ-lactone oxidase was used as a probe. When genomic DNA of the mutant rat was digested with several restriction enzymes, the probe hybridized to fragments of the same sizes as those produced from DNA of normal rats. Poly(A)+RNA from the liver of the mutant rat was found to contain an L-gulono-γ-lactone oxidase-specific mRNA of a normal size at a comparable level to that of normal rats. An in vitro translation experiment revealed that the mRNA programmed the synthesis of an enzyme protein which had the same molecular weight as that of the translational product of the normal mRNA, although the amount synthesized was markedly reduced as compared with that synthesized with the normal mRNA. In accordance with this observation, a very low but definite degree of L-gulono-γ-lactone oxidase activity was detected in the microsomes of the mutant rat by a newly developed, highly sensitive method.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-0533
    Keywords: Key words Cytosine arabinoside ; Heterotopia ; Microcephaly ; Hippocampus ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Pregnant mice were injected intraperitoneally with cytosine arabinoside (Ara-C) on days 13.5 and 14.5 of pregnancy. The brains of their offspring were studied histologically and histochemically. In addition to dysgenic microcephaly, nodular structures consisting of cells with a relatively homogeneous morphology were observed in the depths of the cerebral cortex. The cell clusters were first seen around postnatal day 4, and had a cellular continuity with the disarrayed pyramidal cell layer in the CA1 region of the hippocampus. Golgi-Cox staining showed a number of pyramidal-shaped cells in the clusters. Morphologically, they resembled the pyramidal neurons of the hippocampus. Immunohistochemical examination, using anti-serotonin or anti-tyrosine hydroxylase antibodies, also indicated similarities between the cell clusters and the pyramidal cell layer. It is, therefore, proposed that the cell clusters consisted of heterotopic pyramidal cells of the hippocampus. A few synaptic structures could already be detected in the heterotopic cell clusters on postnatal day 3 by electron microscopy. This early establishment of synaptic contact with related neurons may have caused the heterotopic localization of the pyramidal cells.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 38 (1982), S. 120-122 
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The possible mechanism of neuropathic effect of chinoform was investigated using cultured retinal neuroblasts from chick embryos. Retinal neuroblasts completely degenerated by chinoform-ferric chelate within a day. This change, however, was not observed with free chinoform or ferric ion.a-Tocopherol had a potent protective effect on the toxicity of the chelate. From these results, it was concluded that the lipid peroxidation due to ferric ion chelated with chinoform incorporated into the membrane of nerve tissues is the most important step in induction of the neuropathy.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Determination of low molecular weight carbohydrates in marine environments indicated that 1-O-β-D-galactosylglycerol, 6-O-α-D-galactosyl-1-O-β-D-galacto-sylglycerol, sucrose, laminaribiose and laminaritriose are widely distributed in seawaters, suspended and sinking particles, and sediments in coastal as well as in deep-sea waters [e.g. Mikawa Bay and Sagami Bay, Kumano Nada (offshore Japan), and northwest North Pacific Ocean, Bering Sea and Antarctic Ocean: collections during 1978–1984]. Identification of these glycosylglycerols and oligosaccharides in algal cells such as a flagellate (Olisthodisus luteus), blue-green algae (e.g.Trichodesmium sp.) and a diatom (Reptocylindrus denicus) strongly suggests that these sugars are photosynthetically produced by algae in the euphotic zone and are then rapidly transported to the deep sea as sinking particles which can be collected by sediment-trap experiments. The rapid decay rate of low molecular weight carbohydrates by microorganisms suggests that the transported sugars provide energy substrates for microorganisms living in the deep sea.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    The journal of membrane biology 18 (1974), S. 379-397 
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary The macrocyclic polyethers 4′-methylbenzo-15-crown-5 (15C5) and 4′-methylbenzo-18-crown-6 (18C6) as well as the corresponding crown polymers and crown-styrene copolymers were used as carriers for the transport of sodium and potassium picrate or the corresponding chlorides across a stirred, chloroform membrane. The observation of pronounced bathochromic shifts in the optical spectra of picrate salts on increasing the interionic ion pair distance could be utilized in determining the nature and structure of the migrating species. These species were found to be ion pair crown complexes of at least two kinds, viz., crown-complexed tight ion pairs and crown-separated ion pairs. The feasibility to thus identify the detailed structure of the migrating ionic entity is important as solvents of low polarity such as chloroform or hexane have been used as liquid membranes to represent the interior of biomembranes. The structure of the ion pair is expected to be an important consideration in correlating properties such as membrane potentials or cation selectivities with ionic distribution equilibria. Ion pair extraction equilibrium constants were determined in the H2O−CHCl3 system for the various crown species. The values for 18C6 with sodium and potassium picrate are nearly the same as those for the corresponding polymers. The same was found with 15C5 and sodium picrate; but the potassium forms, in addition to a 1∶1 complex, a 1∶2 complex with 15C5, making the corresponding polymer a more effective extracting agent. The ionic distribution data were interpreted in terms of the salt partition coefficients and the complex formation constants of the ion pair crown complexes in chloroform. The salt migration across the liquid membrane was found to be controlled by the diffusion of the ion pair complex in the chloroform, the extraction equilibrium across the interphase being rapidly established. The thickness of the diffusion layer adjacent to the water-chloroform interphase was estimated to be 50 μ. The ratios of the salt fluxes under otherwise identical conditions were found to be governed by the extraction equilibrium constants, the selectivity ratio for the potassium-to-sodium picrate with 18C6 being 118. This ratio, which was also determined for other crown species, was found to be anion dependent.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-0630
    Keywords: 61.70 ; 61.80
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Transmission electron microscopy, optical reflection and channeling effect measurements are employed to investigate disorders in 30 keV, high dose (3×1016ions/cm2) and high current (≦5 mA) phosphorus as-implanted silicon with (111), (100), and (110) orientation as a function of temperature rise (100–850°C) by the beam heating effect during implantation. Temperature rise below 400°C results in continuous amorrphous layer formation. This contrasts with results of the recovery into single crystals for temperature rise samples above 500°C, regardless of wafer orientation. Secondary defects (black-dotted defects, dislocation loops and rodlike defects) are formed in singlecrystal recovery samples, having a deeper distribution in (110) wafers and a shallower distribution in (111) and (100) wafers. Rodlike defects observed in 850°C samples are of “vacancy” type and have the largest density in (110) wafers.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 42 (1981), S. 362-370 
    ISSN: 1432-1106
    Keywords: Carotid baroreceptor ; Pain afferents ; Pontine neurone ; Rat ; Supraoptic nucleus neurone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Effects of pressure stimulation of the isolated carotid sinus, of occlusion of the common carotid artery and of tail pinching on the discharge activity of dorsal pontine area neurones and antidromically identified supraoptic neurosecretory neurones were studied in male rats anaesthetized with urethane. Electrical stimulation of the supraoptic nucleus (SON) produced antidromically conducted action potentials in a small number (24/384) of the units recorded in the dorsal pontine area. Pressure pulse stimulation of the isolated carotid sinus inhibited and carotid occlusion facilitated discharge activity in some of the tested dorsal pontine area neurones. In these responsive pontine neurones a transient excitation of grouped discharges was occasionally observed to concur with a small, spontaneous depression of the arterial blood pressure. Tail pinching excited some of these pontine neurones. Histological examination revealed that these responsive neurones were located in the dorsal pontine area close, but ventral and lateral, to the locus coeruleus. Electrical stimulation of the dorsal pons evoked a synaptically mediated excitation in 20 and inhibition in the other seven of the 52 SON units which were identified antidromically after stimulation of the pituitary stalk. Pressure stimulation of the isolated carotid sinus evoked an inhibition of discharge activity in some of the SON units which were excited by dorsal pontine area stimulation. All of the six tested units which showed inhibition after dorsal pontine area stimulation were unresponsive to pressure stimulation. Based on these data, it was concluded that at least some of the neurones which mediate carotid baroreceptor inputs to SON neurosecretory neurones are located in the dorsal pontine area close, but ventral and lateral, to the locus coeruleus and that these dorsal pontine area neurones also mediate converging synaptic inputs originating from somatic pain receptors.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 39 (1980), S. 121-124 
    ISSN: 1432-1106
    Keywords: Amygdala ; Medial preoptic nucleus ; Median eminence ; Rat ; Synaptic plasticity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Stimulation-dependent changes in synaptic effects were observed in medial preoptic nucleus neurones during stimulation of the amygdala or pyriform cortex in anaesthetized female rats. The changes occurred after 35–240 triple pulse stimuli repeated at 0.89 Hz. Median eminence stimulation did not produce any synaptic change. These data show the existence of synaptic plasticity in the neural pathway from the amygdala and pyriform cortex to the medial preoptic nucleus.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 71 (1988), S. 291-297 
    ISSN: 1432-1106
    Keywords: ACTH ; Emotional response ; Motor activity ; Vasopressin ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In an attempt to find whether vasopressin (VP) secretion is suppressed by learned emotional stress, we have given rats under a hypertonic condition simultaneously applied light and tone that had been paired previously with footshocks and have quantified immunoreactive VP (ir-VP) in the plasma. In a training session light (60 watt) and tone (2 kz) of 3-s duration which were paired with electric footshocks (50 Hz, 1-s duration) were given to rats 11 times at an interval of 30 s. Various lengths of time after the training, the rats were tested with light and tone, which were unpaired with footshocks and repeatedly applied every 15 s for 3 min in the box used for training. Hypertonic NaCl (0.5 M, 2 ml/ 100 g b. w.) was injected s. c. 30 min before testing to increase the basal level of plasma VP. After testing, plasma ir-VP was significantly less in the experimental group than in the 0-mA control group of rats that were trained without FS. The values for the experimental group were also significantly less than those of untested control rats that had been trained with FS but were not tested. Plasma osmolality and blood haemoglobin concentration were not significantly different between control and experimental groups. Plasma immunoreactive adrenocorticotrophic hormone (ir-ACTH) level was higher and motor activity as expressed by cumulative time period of body movement during testing was lower in the experimental group than in either of the control groups. The difference in plasma ir-VP between experimental and control groups was statistically significant two days but not seven days after training, whereas ACTH and motor activity in experimental groups were still significantly different from those in control groups seven days after training. The suppressive VP and augmentative ACTH responses to testing disappeared in the rats that had received light and tone repeatedly during the intervening period between training and testing. These data support the hypothesis that emotional stimuli suppress VP secretion.
    Type of Medium: Electronic Resource
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