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
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 15-18 (Jan. 1987), p. 261-266 
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Diabetologia 23 (1982), S. 108-113 
    ISSN: 1432-0428
    Keywords: Insulin delivery rate ; insulin secretion in hyperthyroidism ; glucose ; arginine ; insulin disappearance rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Insulin delivery rates were estimated from the peripheral serum insulin response to a single bolus injection of glucose or arginine in eight normal subjects and eight patients with hyperthyroidism. The mean rate constant for insulin disappearance was 0.2380±0.0052 per min in the control subjects, which was not significantly different from that observed in the patients with hyperthyroidism (0.2147±0.0111 per min). There were also no significant differences in the insulin response to glucose infusion (1.7±0.3 U during the first phase (0–10 min) and 5.6±1.6 U during the second phase (11–60 min) in normal subjects compared with 1.2±0.5 and 3.7±1.1 U respectively in the hyperthyroid patients). The delivered insulin in response to glucose infusion was similar in the two groups. The kg-value in the patients with hyperthyroidism was lower than that in the control subjects (1.24±0.11 versus 2.11±0.22;p 〈 0.005). In hyperthyroidism, the low kg-value was not a result of the diminished insulin delivery to the general circulation. Insulin delivery showed a monophasic pattern following arginine infusion in both patients and control subjects. For the control subjects, the amount of insulin delivered was estimated to be 0.53±0.12 U during the first 10 min and 0.37±0.14 U during 11–30 min. In hyperthyroidism, the amount of insulin delivered was significantly lower than in the control subjects (0.21±0.06 U during the first 10 min and 0.07±0.03 U during 11–30 min). In the control subjects, the plasma glucose level was raised transiently following arginine infusion, but in hyperthyroidism, there was no change in plasma glucose levels. In hyperthyroidism, therefore, glucose intolerance appears to be primarily related to an antagonism of the hepatic effect of insulin by thyroxine rather than an inhibitory effect of thyroxine on insulin secretion. However, since delivery rate represents the measurement of peripheral serum insulin concentrations, these results cannot exclude an abnormality of hepatic insulin metabolism in hyperthyroidism.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-0428
    Keywords: Insulin delivery rate ; insulin secretion in man ; glucose ; tolbutamide ; insulin disappearance rate ; biphasic insulin secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Serum insulin response to a single bolus of IV glucose or tolbutamide was measured in eight healthy subjects. Insulin disappearance rate was assessed by deconvolution from the serum insulin levels, using the measured insulin disappearance rate. The mean rate constant of insulin disappearance was 0.238±0.005 min−1 (mean±SEM). Basal insulin delivery rate was 8.0 to 9.0 mU/min and the delivery rate following glucose injection (0.5 g/kg body weight) showed a biphasic response, whereas that after tolbutamide injection (15.6 mg/kg body weight), a monophasic response. After glucose injection, 1.7±0.3 U of insulin was delivered during the first phase (0–10 min) and 5.6±1.6 U during the second phase (11–60 min). After tolbutamide injection, 1.5±0.3 U of insulin was delivered during the first 10 min. Between 11 and 40 min, 1.6±0.5 U of insulin was delivered. The results thus confirm and also quantitate biphasic insulin secretion after a bolus of glucose with a monophasic response after tolbutamide. The method is suitable for studies of the insulin secretogogues in man.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-0428
    Keywords: Keywords Diabetes mellitus ; diabetic nephropathies ; renal circulation ; albuminuria ; glomerular capillary hypertension.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Aims/hypothesis. Results from animal models of glomerular hypertension have suggested that this disorder is one cause of albuminuria in diabetic nephropathy. We evaluated this hypothesis clinically. Methods. The subjects were 20 patients with Type II (non-insulin-dependent) diabetes mellitus but without uraemia or hypertension: 8 had normoalbuminuria and 12 had albuminuria ( ≥ 20 μg/min). In the 2-week study, patients were on a diet with ordinary amounts of sodium for 1 week and on a sodium-restricted diet for 1 week. Urinary excretion of sodium and albumin and the systemic blood pressure were measured daily. Intrarenal haemodynamics, in terms of the glomerular pressure and resistance of afferent and efferent arterioles, were calculated from renal clearance, the plasma total protein concentration, and the pressure-natriuresis relation. In 8 of the 12 patients with albuminuria, an angiotensin-converting enzyme inhibitor, cilazapril, was given orally (2 mg/day) and the 2-week study was repeated. Results. In patients with albuminuria, resistance of efferent arterioles and the glomerular pressure were higher than in patients with normoalbuminuria (glomerular pressure, 53 ± 5 vs 43 ± 5 mmHg, means ± SD, p 〈 0.001). Urinary excretion of albumin correlated (n = 20, r = 0.675, p 〈 0.001) with the glomerular pressure but not with systemic pressure. The increased glomerular pressure and the albuminuria were decreased by cilazapril but systemic pressure was not. Conclusion/interpretation. These findings are consistent with the hypothesis that glomerular hypertension is present in Type II diabetic patients with early nephropathy and can cause albuminuria. [Diabetologia (1999) 42: 999–1005]
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 90 (1989), S. 5918-5923 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The ν3 band of NH+2 in the X˜ 3B1 ground electronic state was observed in direct absorption with a tunable difference frequency laser spectrometer in the 3 μ region, using velocity modulation detection. NH+2 and NH+3 ions were generated in an ac discharge of He and NH3, or of He, N2, and H2. Fifty-three rovibrational transitions were measured and fit to a triplet A-reduced Hamiltonian to determine rotational, centrifugal distortion, and spin–rotation constants. The band origin was found to be ν0=3359.932 cm−1, in excellent agreement with a recent calculation of Jensen, Bunker, and McLean. Indirect evidence from the spectrum suggested that NH+2 is quasilinear, but selection rules prevented a determination of the A rotational constant.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 90 (1989), S. 5910-5917 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The ν3 degenerate vibration–rotation band of the ammonia cation NH+3 was observed and analyzed. The spectrum was detected in direct absorption using a tunable difference frequency spectrometer combined with velocity modulation. The ion was produced in a 6 kHz ac discharge with a gas mixture of He:H2:NH3 (∼250:8:1) and with a total pressure of ∼6 Torr. Spin–rotation splittings for most Q-branch transitions were well resolved and spin–rotation interaction constants were determined. A symmetric rotor Hamiltonian with A1–A2 splittings and l resonance was used to analyze the spectrum. The spectral pattern indicates that NH+3 is a planar molecular with D3h symmetry, consistent with a 2A‘2 ground electronic state.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 88 (1988), S. 79-91 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The vibrational spectra of the clusters H+3(H2)n were observed near 4000 cm−1 by vibrational predissociation spectroscopy. Spectra of mass-selected clusters were obtained by trapping the ions in a radio frequency ion trap, exciting vibrational transitions of the cluster ions to predissociating levels, and detecting the fragment ions with a mass spectrometer. Low resolution bands of the solvent H2 stretches were observed for the clusters of one to six H2 coordinated to an H+3 ion. The red shift of these vibrations relative to the monomer H2 frequency supported the model of H+9 as an H+3 with a complete inner solvation shell of three H2, one bound to each corner of the ion. Two additional bands of H+5 were observed, one assigned as the H+3 symmetric stretch, and the other as a combination or overtone band. High-resolution scans (0.5 and 0.08 cm−1) of H+n, n=5, 7, and 9 yielded no observable rotational structure, a result of either spectral congestion or rapid cluster dissociation. The band contour of the H+5 band changed upon cooling the internal degrees of freedom, but the peaks remained featureless. The observed frequencies of H+7 and H+9 agreed well with ab initio predictions, but those of H+5 did not. This deviation is discussed in terms of the large expected anharmonicity of the proton bound dimer H+5.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 86 (1987), S. 3807-3815 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Recently the presence and radiative decay of vibrationally excited CH−2, generated in a hot cathode discharge of methane, was established by measuring the time dependent photodetachment from excited states of CH−2 as it radiatively relaxed in a high vacuum ion trap. The time dependence of the photodetachment was found to be consistent with an electron affinity of 5250 cm−1 (0.65 eV) for ground state X˜ 3B1 methylene. The radiative decay lifetimes of the first three excited bending vibrations of CH−2 were also tentatively assigned. Here, we report a more refined analysis of the experimental data along with theoretical ab initio determinations of the radiative decay lifetimes of the first four excited bending vibrational levels of CH−2. There is some discrepancy between the ab initio values (431, 207, 118, and 68 ms for the v2=1, 2, 3, and 4 levels respectively) and the experimental values (525, 70, and 14 ms for v2=1, 2, and 3 respectively) for v2=2 and 3. Possible reasons for this discrepancy are discussed but none of the alternatives are entirely satisfactory.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 86 (1987), S. 508-515 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The spin-forbidden radiative decay of a 4Πu O+2 has been measured in a radio frequency octopole ion trap. Photodissociation is used to probe the a 2Πu population as a function of trapping time. We have found that the a 4Πu state exhibits a multiple exponential decay, ranging from a few milliseconds to hundreds of milliseconds. The state dependence of the decay is seen in the photodissociation spectrum (b 4Σ−g←a 4Πu), which changes dramatically from 0.1 to 100 ms. The major changes in the spectrum are simulated by assuming that the F2 and F3 spin components of the a 4Πu state decay faster than the F1 and F4 components. We can account for this dependence on spin sublevel by assuming that the primary mechanism for radiative decay arises from spin-orbit coupling of the a 4Πu and A 2Πu states. Our results suggest that the a 4Πu radiative lifetime of 0.22 s measured by O'Keefe and McDonald reflects the decay of only the longest living a 4Πu sublevels.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 91 (1989), S. 7319-7330 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The gas phase infrared spectra of the hydrated hydronium cluster ions H3O+⋅(H2O)n(n=1, 2, 3) have been observed from 3550 to 3800 cm−1. The new spectroscopic method developed for this study is a two color laser scheme consisting of a tunable cw infrared laser with 0.5 cm−1 resolution used to excite the O–H stretching vibrations and a cw CO2 laser that dissociates the vibrationally excited cluster ion through a multiphoton process. The apparatus is a tandem mass spectrometer with a radio frequency ion trap that utilizes the following scheme: the cluster ion to be studied is first mass selected; spectroscopic interrogation then occurs in the radio frequency ion trap; finally, a fragment ion is selected and detected using ion counting techniques. The vibrational spectra obtained in this manner are compared with that taken previously using a weakly bound H2 "messenger.'' A spectrum of H7 O+3 taken using a neon messenger is also presented. Ab initio structure and frequency predictions by Remington and Schaefer are compared with the experimental results.
    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...