Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Electronic Resource  (40)
  • 1980-1984  (40)
  • 1950-1954
  • 21
    Electronic Resource
    Electronic Resource
    LOCALIZATION OF MYROSINASE (THIOGLUCOSIDE GLUCOHYDROLASE, EC 3.2.3.1) IN COTYLEDON CELLS OF RAPESEED (1981)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food biochemistry 5 (1981), S. 0 
    Details
    ISSN: 1745-4514
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Myrosinase (thioglucoside glucohydrolase, EC 3.2.3.1) activity in dehulled seeds of Brassica napus cultivar Tower, B. campestris cultivar Candle and B. juncea (oriental mustard) was localized by cyto-chemical and biochemical procedures. It was found to be associated with the plasmalemma (plasma membrane) in the majority of embryonic cells which is contrary to the general belief that myrosinase is found only in a few specialized idioblasts called ‘myrosin cells’. The presence of lead and sulfur in electron-opaque deposits resulting from in situ myrosinase activity was confirmed by energy dispersive X-ray analyses. Association of myrosinase activity with the plasmalemma was also verified by fractionation and biochemical procedures. Although there were indications of some myrosinase activity in aleurone grains (protein bodies), the evidence was inconclusive.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1745-4514.1981.tb00660.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Asymmetrical effects of morphine and naloxone on reward mechanisms (1982)
    Springer
    Psychopharmacology 78 (1982), S. 219-224 
    Details
    ISSN: 1432-2072
    Keywords: Morphine ; Naloxone ; Cerebral asymmetry ; Self stimulation ; Rotation ; Reinforcement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats with bilaterally implanted lateral hypothalamic electrodes were tested daily for self-stimulation to each side of the brain, and rotation (circling behavior) was recorded concomitantly. All rats rotated in a preferred direction regardless of the side of the brain stimulated and all rats had asymmetries in self-stimulation sensitivity related to the direction of rotation. Morphine increased rotation and lowered self-stimulation thresholds at low doses (e.g., 2.5 mg/kg) and decreased rotation and raised self-stimulation thresholds at high doses (e.g., 20.0 mg/kg). The changes in self-stimulation thresholds preferentially occurred on opposite sides of the brain, i.e., the low-dose decrease in thresholds was greater in the normally less sensitive side of the brain whereas the high-dose increase in thresholds was greater in the normally more sensitive side of the brain. Naloxone produced no changes in rates of rotation but did elicit small changes in self-stimulation that varied with the side of the brain, i.e., dose-related decreases in thresholds occurred in the normally more sensitive side of the brain whereas dose-related increases in thresholds occurred in the normally less sensitive side of the brain. Subsequently rats were tested in a choice procedure providing concurrent access to rewarding stimulation of either side of the brain; currents were titrated such that, under baseline conditions, rats continually alternated between self-stimulating one side of the brain or the other. Morphine induced a preference for the less sensitive side of the brain that was comparable in magnitude at all doses and independent of its biphasic effects on rates of responding. Naloxone induced a dose-related preference for the more sensitive side of the brain while not altering rates of responding. Naloxone (1.0 mg/kg) also completely antagonized the effects of all doses of morphine. The results are discussed in terms of lateralized actions mediating the discriminable effects of reinforcing drugs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00428154
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Amphetamine enhancement of reward asymmetry (1981)
    Springer
    Psychopharmacology 73 (1981), S. 323-327 
    Details
    ISSN: 1432-2072
    Keywords: Amphetamine ; Self-stimulation ; Cerebral asymmetry ; Rotation-Dopamine ; Schizophrenia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats with bilaterally implanted lateral hypothalamic electrodes were tested daily for self-stimulation to each side of the brain; rotation (circling behavior) was recorded concomitantly. All rats rotated in a perferred direction regardless of the side of the brain stimulated and all rats had asymmetries in self-stimulation sensitivity (threshold and rate-intensity functions) related to the direction of rotation. Amphetamine both enhanced rotation and potentiated the asymmetry in self-stimulation sensitivity. Subsequently rats were tested in a choice procedure providing concurrent access to rewarding stimulation of either side of the brain; currents were titrated such that, under baseline conditions, rats continually alternated between self-stimulating one side of the brain or the other. Amphetamine induced a robust preference for stimulation to the more sensitive side of the brain (the side having a lower thereshold). The results are discussed in relation to mechanisms of drug reinforcement and to biological etiologies of schizophrenia. It is proposed that schizophrenia results from a lateralized overactivity of dopaminergic neuronal systems mediating reward and that amphetamine mimics schizophrenic symptomatology by enhancing lateralization of the same systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00426459
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Budapest Treaty Makes Biotechnology Patenting Simpler (1983)
    [s.l.] : Nature Publishing Company
    Nature biotechnology 1 (1983), S. 801-801 
    Details
    ISSN: 1546-1696
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: [Auszug] Although a written description may fill the disclosure requirement for a patent for mechanical, electrical, or chemical inventions, biotechnology inventions require a publicly available microorganism deposit to fill this requirement. Internationally minded corporations that file biotechnology ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/nbt1183-801a
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Storm trajectories in eastern US D/H isotopic composition of precipitation (1982)
    [s.l.] : Nature Publishing Group
    Nature 296 (1982), S. 638-640 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Very large differences in the D/H ratios from storm to storm were observed. The 8D range for all storms was -7%〉 to -170%〉 SD = (D/H sample - D/H SMOW)/(D/H SMOW) x 103, where SMOW is standard mean ocean water. In general the storms with the highest deuterium contents occurred during the warm ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/296638a0
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Ecophysiology of Yucca brevifolia, an arborescent monocot of the Mojave sesert (1983)
    Springer
    Oecologia 60 (1983), S. 10-17 
    Details
    ISSN: 1432-1939
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Photosynthetic characteristics and transpiration of Yucca brevifolia, an evergreen tree endemic to the Mojave Desert of California and Nevada, were examined in the field and the laboratory. Yucca brevifolia was confirmed to be a C3 plant, with no CAM tendencies observed for its semi-succulent leaves. The species exhibited a maximum net CO2 uptake of 12 μmol m-2 s-1 at 22°C when grown at day/night air temperatures of 31°C/17°C (data expressed on a total area basis for these opaque leaves). The optimum temperature for CO2 uptake shifted 4.5°C per 10°C change in daytime growth temperature, so that observed leaf temperatures in the field were near optimum temperatures throughout the midday period in all but the hottest months of the year. Leaves also acclimated to low and high temperature extremes, tolerances ranging to-11°C and to 59°C, respectively, suggesting that low temperatures limit the distribution of Y. brevifolia but high temperatures do not. Light saturation of photosynthesis occurred at a relatively low PAR of about 500 μmol m-2 s-1, similar to the actual PAR within a rosette. Diurnal patterns of leaf conductance shifted from a broad midday peak in wet seasons to a reduced, narrow, early morning peak in the dry season, indicating effective stomatal control of water use. The approximately 5-month-long winter-spring growth season accounted for 80% of the yearly CO2 uptake, with a predicted annual uptake of about 22 mol m-2 y-1 and a transpiration ratio of 700.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00379313
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Poorly selective cation channels in the skin of the larval frog (Stage≤XIX) (1982)
    Springer
    Pflügers Archiv 394 (1982), S. 287-293 
    Details
    ISSN: 1432-2013
    Keywords: Noise analysis ; Tadpole skin ; Apical membrane ; Cation channel ; Barium ; TEA (Tetraethyl ammonium) ; Amiloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The abdominal skin of bullfrog larvae (Rana catesbeiana) was placed in an Ussing-type chamber, and its transepithelial electrical parameters were recorded with mucosal solutions of different ionic composition. With “K+-like” cations (K+, NH 4 + , Rb+, Cs−) the power spectra of the fluctuations in short-circuit current displayed a Lorentzian component (f c =30–40 Hz). The relaxation noise could be suppressed by addition of the K+-channel blockers Ba2+ and TEA to the mucosal solution. Also, in presence of the ionophore antibiotic nystatin the Lorentzian noise was abolished. The Na+-channel probes amiloride and benzimidazolyl-2-guanidine (BIG) both enhanced the relaxation noise obtained with the K+-like cations but, with Na+, and Li+, also caused the rise of a relaxation component above the background noise. In presence of amiloride or BIG, the addition of Ba2+, TEA and nystatin still abolished the Lorentzian noise. It can be concluded that the relaxation-noise source is located in the apical cell membranes of the tadpole skin. These spontaneously fluctuating cation channels do not seem to strictly discriminate between K+-like ions (K+, NH 4 + , Rb+, Cs+) and Na+-like ions (Na+, Li+). On the other hand, well-known specific probes for K+ channels (Ba2+, TEA) and for Na+ channels (amiloride, BIG) interact with this apical cation channel. It is possible that the poorly selective channel plays a role in the ontogenesis of the specific Na+ transport in the maturing frog skin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00583692
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Synaptic vesicle activity in stimulated and unstimulated photoreceptor axons in the housefly. A freeze-fracture study (1982)
    Springer
    Journal of neurocytology 11 (1982), S. 747-761 
    Details
    ISSN: 1573-7381
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Light-stimulated and unstimulated photoreceptor (retinular) axon terminals in the lamina ganglionaris (first optic neuropil) of the housefly are examined using freeze-fracture replication. The presence of numerous, cross-fractured capitate projections permits unmistakable identification of the retinular axon terminal membrane. Regardless of the conditions of illumination, the protoplasmic face (P-face) of the terminal membrane contains numerous bowtie-shaped particle clusters (active zones) which resemble theen face form and disposition of the presynaptic ribbon found in thin sections. Estimates from freeze-fractured material indicate that each retinular axon possesses at least 175 such active zones. In eyes fixed during illumination, active zones are surrounded by many membrane dimples indicative of vesicle fusion sites. Such synaptic vesicle sites are seldom encountered in terminals which are dark-adapted and fixed in the dark. Results from light-adapted eyes placed in the dark following the onset of fixation suggest that endocytosis may occur in the extrasynaptic regions of this inhibitory synapse. P-face particles are uniformly distributed throughout the extrasynaptic regions of unstimulated terminals. Particle density increases in areas peripheral to the active zones in stimulated eyes, particularly within the regions presumed to be undergoing active endocytosis. These structural findings are discussed in the context of the Heuser-Reese model of vesicle exocytosis and recycling.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01153517
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    The fine structure of neuroglia in the lamina ganglionaris of the housefly,Musca domestica L. (1983)
    Springer
    Journal of neurocytology 12 (1983), S. 213-241 
    Details
    ISSN: 1573-7381
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Six morphologically distinct glial cell layers are described in the housefly lamina ganglionaris, a region previously thought to be composed of only three. 1. The external glial layer abuts the basement membrane of the retina. The cells of this layer have a highly involuted surface membrane and an abundance of ribosomes and rough endoplasmic reticulum (ER) throughout their cytoplasm. They envelop the traversing photoreceptor and mechanoreceptor axons as well as the large tracheoblast cells of the fenestrated layer. They are referred to as thefenestrated layer glia. 2. The second glial layer is composed of large, horizontally elongated cells with large elongate nuclei. They contain large membrane-bounded vacuoles and extensive arrays of parallel-running microtubules and smooth ER. These glia invest the photoreceptor axons through much of the multiple chiasmatic (pseudocartridge) region and are thus designated as thepseudocartridge glia. 3–4.Satellite glia comprise the third and fourth glial layers. Thin cytoplasmic processes of these multipolar glia intervene between the tightly packed monopolar neuron somata and the photoreceptor axons of the nuclear layer. The satellite glia are distinguished into two sub-groups: distal and proximal. The distal satellite glia are exclusively responsible for the large glial invaginations of the type I monopolar cell bodies. Multilaminated processes of the proximal layer of satellite glia surround the photoreceptor axons and the neurite neck of the monopolar neurons prior to their entry into the plexiform layer. The proximal satellite glia also contain prominent lipid deposits. 5.Epithelial glia are columnar cells that occupy the plexiform layer. They envelop the optic cartridges of the neuropil and are the substrate for two characteristic glial-neuronal invaginations; i.e. the capitate projection and the ‘gnarl’. The cytoplasm of the epithelial glia is electron dense and contains numerous stacked arrays of infolded membrane. 6.Marginal glia form the proximal boundary of the optic neuropil. They invest the axons entering or leaving through the base of the lamina ganglionaris. Marginal glia contain large numbers of parallel microtubules and numerous polyribosomes. Fine structural evidence is presented relevant to the role of these six glial layers in the maintenance of ionic and metabolic homeostasis across the retina-lamina barrier.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01148463
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Glial membrane specializations and the compartmentalization of the lamina ganglionaris of the housefly compound eye (1983)
    Springer
    Journal of neurocytology 12 (1983), S. 243-275 
    Details
    ISSN: 1573-7381
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Membrane specializations in the lamina ganglionaris of the housefly are investigated using conventional thin-section EM, freeze-fracture replication and the diffusion of colloidal lanthanum. All glial cells in the lamina are coupled by gap junctions. Desmosomes also link all glia except the epithelial glia. Extensive glia-glial and glia-neuronal septate junctions are present in the pseudocartridge zone and nuclear layer. Septate junctions in the nuclear layer intermingle with bands of interglial and glia-neuronal tight junctions. Tight junctions are also found between satellite and epithelial glia at the border of the nuclear and plexiform layers, between adjacent epithelial glial cells in the plexiform layer, between epithelial and marginal glia at the proximal boundary of the optic neuropil, between marginal glial cells, and between marginal glia and axons. Colloidal lanthanum, introduced through an incision in the cornea, penetrates the retina but is occluded from the neuropil by septate junctions in the pseudocartridge zone. The disposition of tight and septate junctions is described in relation to the compartmentalization of the lamina. Two major compartments are delineated. The first represents the nuclear layer and contains the cell bodies of second-order visual neurons (monopolar neurons). The second compartment constitutes the plexiform layer of the lamina. Within the plexiform layer, each optic cartridge is partitioned into a separate subcompartment. Also, tracheoles and axons of long visual fibres are isolated from the optic cartridges by glial tight junctions. Morphological evidence for compartmentalization is correlated with previously established electrical properties of the insect lamina ganglionaris.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01148464
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...