Library

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report the results of dc magnetization and electrical resistivity studies of a single-domain Al70Ni15Co15 decagonal quasicrystal. The temperature dependence and anisotropy of the electrical resistivity are in excellent agreement with previous results for a similar sample. The magnetic properties were determined by superconducting quantum interference device magnetometry over the temperature range 1.8–300 K for magnetic fields between 10 Oe and 10 kOe. The magnetic behavior can be characterized by a weak ferromagnetic component M0(H) which saturates in moderate fields (H≈1 kOe) and a differential susceptibility, χ0=ΔM/ΔH, obtainable from the high-field data. The observed magnetization M=χ0H+M0 is slightly anisotropic and essentially temperature independent below room temperature. For H parallel to the quasicrystal axis, we observe χ0(parallel)=7.1×10−7 emu/g and M0(parallel)=2.0×10−3 emu/g. For H perpendicular to the quasicrystal axes, we obtain χ0⊥=8.2×10−7 emu/g and M0⊥=1.7×10−3 emu/g. An anisotropic and weak superconducting transition was observed at T=3.2 K, corresponding to a superconducting volume fraction of only ∼10−3.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 5 (1973), S. 0 
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Following analysis of the serum of the blood of the plaice (Pleuronectes platessa L.), a Ringer solution specific for this fish has been devised and tested. It has proved a satisfactory physiological saline for use in electrophysiological experiments and in the preparative procedures for electron microscopy.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The magnetic-field penetration depth A of high-rc cuprate superconductors has been extensively studied by using the muon spin relaxation (juSR) technique1'2'4'5. The magnitude of A, which can be determined precisely from the muon spin relaxation ratemetals9. These results suggest that fundamental ...
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Archives of gynecology and obstetrics 264 (2000), S. 137-142 
    ISSN: 1432-0711
    Keywords: Keywords Colposcopy ; Vaginal smears ; Networking ; Continuing medical education
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Background: Women who participate in cervical cancer screening programs must have access to high quality colposcopy services when their cytology test are abnormal. The purpose of this project is to evaluate colposcopic services currently available in New Hampshire and whether colposcopy providers are willing to network to maintain and improve their colposcopic pattern recognition skills in order to improve their colposcopic correlations. Methods: A survey was mailed to 1314 providers throughout New Hampshire. The survey ascertained the extent of current colposcopic services in New Hampshire through practitioner and practice demographics, the cervical procedures performed, the self-reported colposcopy skill level, and the self-reported quality of past colposcopic education. It also measured interest in networking with others to improve their colposcopic pattern recognition skills. Results: The survey response rate was 62%. 145 of the 810 respondents (18%) are currently performing colposcopies, indicating a statewide potential colposcopy accommodation rate of 3.5 to 7 women per month per colposcopist. 57% of the physician assistants, 59% of the family physicians, 75% of the gynecologists and 100% of the nurse practitioners were interested in enhancing their colposcopic pattern recognition skills by networking through quarterly meetings. Conclusions: The crude accommodation rate for colposcopy appears sufficient for the women of New Hampshire although the geographic distribution of the colposcopists is unknown. A majority of the colposcopists were interested in networking to improve their colposcopic pattern recognition skills, which could improve patient care.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 26 (1970), S. 768-769 
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Résumé Les corpuscules de Herbst existent dans le m. expansor secundariorum de l'aile de la poule domestique. Il est possible qu'ils conditionnent l'action réflexe du muscle.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neurocytology 18 (1989), S. 749-761 
    ISSN: 1573-7381
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The post-embryonic development of the rectifying Giant Fibre-Motor Giant (GF-MoG) synapse and the Giant Fibre-Segmental Giant (GF-SG) synapse has been investigated using electron-microscopy. In adults, the MoG and SG neurons make contact with the GFs by sending narrow ‘finger-like’ processes through the glial and connective tissue sheath surrounding each GF. The junctional region is characterized by closely apposed membranes (approximately 4 nm separation) traversed by regularly spaced connections, and large (60–80 nm) spherical vesicles in the presynaptic fibre. In newly hatched crayfish junctional contact is made over extensive areas of flat membrane apposition, due to the absence of a thick connective sheath around the giant fibres. Initially the junctional region is dominated by contacts which are morphologically indistinguishable from chemical synapses, i.e. 1. The apposed membranes are separated by a cleft of approximately 20–30 nm (an order of magnitude larger than the cleft distance at electrotonic synapses). 2. There is pre- and post-synaptic thickening of the junctional membranes with a dense cytoplasmic material. 3. Small (25–40nm) pleomorphic vesicles are found on the presynaptic side of the junction, commonly in association with a dense presynaptic bar. Regions of junctional contact displaying the adult electrotonic-type morphology first appear at approximately one week post-hatching. At this age they are limited in distribution and occupy a central position in the area of contact surrounded by a broad ‘chemical-like’ annulus. During subsequent development these sites with electrotonic-type morphology grow in relative size, so that the ‘chemical-like’ sites become compressed towards the edges of the regions of contact. The adult type of morphology, in which the ‘chemical-like’ regions are vestigial, is achieved approximately two months after hatching.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neurocytology 20 (1991), S. 109-123 
    ISSN: 1573-7381
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In a previous paper we showed that the ultrastructure of the giant fibre to motor giant synapse of crayfish changes in the first few weeks after hatching from having predominantly the appearance of a chemical synapse to having the appearance of an electrical synapse. This is parallelled by a behavioural change from non-giant fibre-mediated to giant fibre-mediated tailflips. In this paper we describe the physiology of the giant fibre to motor giant synapse over this period. We find the following: (1) The giant fibre to motor giant synapse usually transmits spikes 1∶1 from the day of hatching. (2) The synapse operates by electrical transmission from the day of hatching, when no connexons are apparent at the ultrastructural level. (3) The synapse has no detectable chemical component, even at an age when the predominant type of junctional apposition has the ultrastructural appearance of a chemical synapse. (4) Inhibitory chemical synapses occur onto the motor giant at the day of hatching, and these show similar physiological characteristics to those which occur onto the motor giant in adults. (5) In some preparations, the giant fibre to motor giant electrical synapse shows rectification similar to that in the adult, but in most cases both depolarizing and hyperpolarizing current injected into the medial giant spreads to the motor giant. (6) Current spread from the medial giant to the motor giant is increased by hyperpolarizing the motor giant neuron, even when medial giant to motor giant transmission is apparently non-rectifying. (7) Both the giant fibre and the motor giant have resting potentials of about −90 mV. There is no standing difference in resting potential as there is in the adult. This may explain the apparent lack of medial giant to motor giant rectification observed in most preparations.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1573-7381
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The post-embryonic development of the non-rectifying septate synapse between homologous lateral giant (LG) fibre segments has been investigated using electron microscopy and electrophysiology. In adults, the LG-LG synapse is characterized by closely apposed membranes (approximately 4 nm separation) traversed by regularly spaced particles, and large (60–80 nm) spherical vesicles on both sides of the junction. In newly hatched crayfish the junction between lateral giant fibre segments comprises regions of close membrane apposition as seen in the adult along with non-specialized areas of wide (10–15 nm) membrane separation. Vesicles associated with these junctions are small (25–40 nm) and pleomorphic. The number of vesicles is low by comparison with adult junctions; in most sections of hatchling junctions there are normally fewer than five vesicles, although as many as 30 have occasionally been seen. During development the non-specialized areas of wide membrane separation become rare and the vesicle population changes to a mixture of small pleomorphic forms and larger (60–80 nm) spherical ones. However even at two months the number of large spherical vesicles is markedly less than that at the adult synapse, while small pleomorphic vesicles are still abundant. Despite the difference between the adult and hatchling vesicle populations, intracellular recordings have shown that the synapse is fully functional as a non-rectifying electrical junction on hatching and that the intracellular marker Lucifer Yellow can pass between adjacent lateral giant fibre neurons.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 163 (1975), S. 99-110 
    ISSN: 1432-0878
    Keywords: Central neuropile ; Planorbis corneus ; Synapses ; Spinule complexes ; Varicosities ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The neuropile in the central ganglia of Planorbis corneus was studied by electron microscopy, using different fixatives. Several types of specialization were observed in the membranes of adjacent axonal processes, varying from only slight membrane thickenings to structures resembling desmosomes. Specialized structures similar to the ‘spinule complexes’ in mammalian brain are widely distributed in certain areas of neuropile. They consist of a small projection which invaginates a neighbouring neurone; the membranes are closely apposed and there is associated electron-dense material. The problem of identifying chemical synapses in this tissue is discussed. Many axonal processes are varicose, and it is suggested that varicosities may also be sites of transmitter release.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 196 (1979), S. 337-346 
    ISSN: 1432-0878
    Keywords: Teleost ; Bulbus arteriosus ; Innervation ; Smooth muscle ; Vascularization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The structure of the bulbus arteriosus of a wide range of teleost fish is described with particular reference to the vascularization and innervation. The adventitia of the organ consists of blood vessels and large nerve bundles in a collagen matrix. The nerve bundles contain monoamines, and fluorescence studies show small terminal bundles penetrating the muscular media; this is confirmed by electron microscopy. The media consists of an extensive elastic tissue matrix with a spiral arrangement of smooth muscle cells joined end to end by desmosomes and presumed electrotonic junctions. The muscle cells are innervated only at the adventitia/media boundary and the significance of this innervation is discussed. It is proposed that there is a correlation between the degree of vascularization and innervation and the activity of a particular species offish.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...