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
  • 1
    Electronic Resource
    Electronic Resource
    Diffusive and segmental dynamics in polymer gel electrolytes (1999)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 111 (1999), S. 11216-11221 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Dynamic light scattering data on a polymer gel electrolyte with a complex relaxation behavior is presented. The electrolyte consists of lithium perchlorate dissolved in an ethylene carbonate and propylene carbonate solution that is immobilized with poly(methyl methacrylate). We attribute the observed relaxation processes to two diffusive and one segmental relaxation processes based on the form of the time decay of the intermediate scattering function and the corresponding temperature and wave vector dependencies. The dynamic light scattering results are compared with the ionic conductivity, which reveals a close connection between the fast diffusive motion of the low molecular weight solvent within the gel and the ionic conductivity. This motion is strongly decoupled from and considerably faster than the segmental motion of the polymer matrix. The results indicate that the ionic transport occurs mainly within the low molecular weight solvent. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.480477
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    A 32-channel preamplifier chip for the multiplicity vertex detector at PHENIX (1999)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 70 (1999), S. 1684-1687 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: The TGV32, a 32-channel preamplifier–multiplicity discriminator chip for the multiplicity vertex detector (MVD) at PHENIX, is a unique silicon preamplifier in that it provides both an analog output for storage in an analog memory and a weighted summed-current output for conversion to a channel multiplicity count. The architecture and test results of the chip are presented. Details about the design of the preamplifier, discriminator, and programmable digital–analog converters performance as well as the process variations are presented. The chip is fabricated in a 1.2 μm, n-well, complementary metal–oxide–semiconductor process. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1149651
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    A photospectrometer realized in a standard integrated circuit process (1998)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 69 (1998), S. 377-383 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A photospectrometer has been realized in a standard integrated circuit (IC) process. Only the masks, materials, and fabrication steps inherent to this IC process were used (i.e., no post processing to add mechanical or optical devices for filtering). The spectrometer was composed of a set of 18 photodetectors with independent spectral responses. The responses of these devices were weighted and summed to form outputs proportional to the input optical power in discrete wavelength bands in the region from ∼400 to ∼1100 nm. With the solution space restricted to a 60 nm band, this instrument could resolve Gaussian input spectra (σ=5 nm) with a peak-to-peak spacing of less than 15 nm. This device could easily be integrated with additional analog, digital, or wireless circuits to realize a true laboratory instrument on-a-chip. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1148457
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Gating of thrombin in platelet aggregates by pO2-linked lowering of extracellular Ca2+ concentration (1995)
    s.l. : American Chemical Society
    Biochemistry 34 (1995), S. 9277-9281 
    Details
    ISSN: 1520-4995
    Source: ACS Legacy Archives
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/bi00029a001
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Elastic strain of freely suspended single-wall carbon nanotube ropes (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 74 (1999), S. 3803-3805 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have induced large elastic strains in ropes of single-wall carbon nanotubes, using an atomic force microscope in lateral force mode. Freely suspended ropes were observed to deform as elastic strings with tension proportional to elongation. Ropes were elastically deformed over 〉10 cycles without showing signs of plastic deformation. The maximum strain observed, 5.8±0.9%, gives a lower bound of 45±7 GPa for the tensile strength (specifically, yield stress) of single-wall nanotube ropes. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.124185
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    A Review of the Concept of Visual Literacy (1997)
    Oxford, UK and Boston, USA : Blackwell Publishers Ltd
    British journal of educational technology 28 (1997), S. 0 
    Details
    ISSN: 1467-8535
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Education
    Notes: Many people from very diverse disciplines have attempted to define the concept of Visual Literacy (VL), but with little general consensus so far. This is probably due to the fact that those representing the different disciplines and paradigms are each wanting to interpret Visual Literacy in a way that reflects and flatters their contribution or way of thinking. As a consequence, a theoretical concept with seemingly little practical value has been created, but cannot be used productively until an agreed definition is established.It is self evident that if a concept does not have a broadly accepted definition, if the theory behind it is confusing, and if its viability on practical terms is a matter of continuing controversy, then the only reasonable way to cope with it is to abandon it. Nevertheless, with the exception of very few and of minor importance cases, no serious attempt has ever been made towards discarding VL altogether.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/1467-8535.00035
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Evidence for Glutamate as Neurotransmitter in Trigemino- and Spinothalamic Tract Terminals in the Nucleus Submedius of Cats (1995)
    Oxford, UK : Blackwell Publishing Ltd
    European journal of neuroscience 7 (1995), S. 0 
    Details
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The nucleus submedius in the medial thalamus of cats is an important termination site for lamina I trigemino- and spinothalamic tract (TSTT) neurons, many of which are nociceptive-specific, and the nucleus submedius has been proposed to be a dedicated nociceptive substrate involved in the affective aspect of pain. In the present study, the distribution of glutamate was examined by immunocytochemical methods in order to evaluate the possible role of this amino acid as a neurotransmitter in TSTT terminals in the nucleus submedius. TSTT terminals were identified by anterograde transport of horseradish peroxidase and wheatgerm agglutinin-horseradish peroxidase conjugate from the spinal cord or the medullary dorsal horn. Quantitative analysis of immunogold labelling revealed that TSTT terminals contain about twice the tissue average of glutamate-like immunoreactivity. A strong positive correlation was found between the density of synaptic vesicles and the density of gold particles in these terminals, whereas no relationship was seen between these variables in GABAergic presynaptic dendrites. Enrichment of glutamate-like immunoreactivity (∼250% of the tissue average) was also observed in terminals of presumed cortical origin. Presynaptic dendrites and neuron cell bodies in the nucleus submedius were found to contain relatively low levels of glutamate-like immunoreactivity, at or below the tissue average. These observations provide evidence that glutamate is a neurotransmitter in lamina I TSTT terminals in the nucleus submedius. The findings also suggest glutamatergic neurotransmission between cortical afferents and nucleus submedius neurons. Glutamate is therefore likely to be an important mediator of nociceptive processing in the medial thalamus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1460-9568.1995.tb01066.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Pronounced resting bradycardia in male elite runners is associated with high heart rate variability (1997)
    Oxford, UK : Blackwell Publishing Ltd
    Scandinavian journal of medicine & science in sports 7 (1997), S. 0 
    Details
    ISSN: 1600-0838
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine , Sports Science
    Notes: Forty-eight hour Holter monitoring was undertaken of 16 male elite middle- and long-distance runners, age 25±3 years, with peak oxygen uptake 4.83±0.43 1 O2/min or 73.0±3.9 ml O2/kg/min. The athletes had pronounced bradycardia during the night-time, with heart rate calculated from four RR intervals 〈30 beats/min in five runners. Twelve of 16 runners had RR intervals 〉2 s. Of those, 10 runners had sinus pauses exceeding 2 s, the longest being 3.06 s. Three runners had AV block II, two with Mobitz type 1, and one with both Mobitz type 1 and 2. Autonomic function was estimated by time domain and power spectral analysis of heart rate variability. The runners were compared with a control group of 13 sedentary or moderately active subjects. The runners had a mean of 14 b.p.m. lower heart rate at night than the controls. The runners had higher heart rate variability in all spectral bands. In the time domain pNN50 and rMSSD, which are considered to reflect strongly vagal tone, were markedly higher in the runners than the controls. The findings suggest that an increased parasympathetic tone might at least partly explain the pronounced resting sinus bradycardias found in endurance-trained runners.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1600-0838.1997.tb00152.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Amplitude and timing of electromyographic activity during sprinting (1996)
    Oxford, UK : Blackwell Publishing Ltd
    Scandinavian journal of medicine & science in sports 6 (1996), S. 0 
    Details
    ISSN: 1600-0838
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine , Sports Science
    Notes: The aim of this study was to make descriptive analyses of the muscle activities in the lower extremity during maximal sprinting. Nine healthy sprinters were examined during maximal sprinting using telemetric electromyography (EMG). Seven muscles of the lower extremities were investigated: biceps femoris, medial hamstrings (semimembranosus and semitendinosus), rectus femoris, gluteus maximus, tibialis anterior, lateral gastrocnemius and medial gastrocnemius. The recorded EMG levels during running were expressed as percentage of maximum voluntary isometric contractions (%max EMG). For each muscle, the normalized EMG was plotted during the whole running stride cycle and is presented for each muscle. The reason for using this method is to show that it is possible to compare different muscle activities in a runner as well as to make comparisons between runners. Lateral and medial hamstrings and gluteus maximus showed similar activities with peak levels of EMG during footstrike. Rectus femoris had a two-peak activity, with one peak at the middle of the stance phase and the other during the swing phase. The tibialis anterior also showed a two-peak activity, but with the peaks at the beginning of the swing phase and just before foot-strike. The highest activities of the medial and lateral gastrocnemius occurred just before toe-off.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1600-0838.1996.tb00064.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Vagal Influence on Deterministic Chaos of Heart Rate in Patients after Acute Myocardial Infarction (1997)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of noninvasive electrocardiology 2 (1997), S. 0 
    Details
    ISSN: 1542-474X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: To test heart rate variability (HRV) in patients with acute myocardial infarction (AMI) for nonlinear deterministic complex behavior and for its dependence on autonomic tone.〈section xml:id="abs1-2"〉〈title type="main"〉MethodsFifteen patients (mean age 55, 14 men) with AMI and 16 healthy individuals (mean age 41, 11 men) with ongoing beta-adrenergic receptor blockade were investigated after intravenouse administration of atropine (0.03 mg/kg). Nonlinear indices for HRV were assessed by local sensitive dependence on initial conditions as quantitated by the Lyapunov exponent, fractal dimension (FD), and correlation dimension. Linear indices for HRV were assessed in the time domain by the standard deviation of the RR interval (SD-RR), the coefficient of variation (CV%), and the mean successive difference (MSD). In the frequency domain, the following indices were used: very low frequency power (VLF), low frequency power (LF), high frequency power (HF), total power (TP), and the ratio between low and high frequency power (LF/HF).〈section xml:id="abs1-3"〉〈title type="main"〉ResultsSurrogate data analysis revealed independent behavior of the Lyapunov exponent, the FD, and the correlation dimension, suggesting the presence of deterministic chaos in HRV. The Lyapunov exponent was positive in both groups at baseline but was significantly lower in the patient group. Following atropine, the value decreased while remaining positive, but no differences between the groups were found. The FD and the correlation dimension reacted similarly to the Lyapunov exponent. All time-domain indices were significantly lower in the patients along with power in LF and HF bands. The differences were abolished by the administration of atropine.〈section xml:id="abs1-4"〉〈title type="main"〉ConclusionsThe heart rate of patients with AMI exhibits characteristics of deterministic chaotic behavior with a positive Lyapunov exponent but with significantly less complex behavior than in healthy controls. The difference was eliminated by atropine, suggesting that vagal tone is a major cause. The nonlinear indices have a discriminating capacity for changes in HRV comparable to linear indices.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1542-474X.1997.tb00202.x
    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...