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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Annales geophysicae 16 (1998), S. 738-742 
    ISSN: 0992-7689
    Keywords: Ionosphere (Equatorial ionosphere, Instruments and Techniques) ; Radio science (ionospheric propagation)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract SCIPION is a new state of the art digital sounder that has been developed by France Telecom-CNET for ionospheric monitoring and research. Extensive data processing using DSP technology has resulted in a low power, low cost and full featured system for both vertical and oblique soundings. A SCIPION system is in the process of being installed in Dakar, Senegal, to study HF propagation in the sub-equatorial ionosphere. However, preliminary results have still been obtained during experiments wit a prototype system. In this paper, the system is described and some illustrative examples of its capabilities are shown.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-1866
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract North of El Algarrobo (one of the four main deposits of the Chilean Iron Belt), the iron-mineralization (magnetite-etrmolite/actinolite-apatite) is related to clinoand orthopyroxene diorite intrusions which have crystallized at shallow depth (4km) under increasing oxygen fugacities. The supercritical fluid phase exsolved during cooling after the consolidation of the plutons (800–900°C), results in a H+, Cl− and sodic enrichment, and in the sequential leaching of Fe (at less than 700°C), then Ca and Mg (between 600 and 500°C) from minerals of the primary magmatic diorite assemblage: titanomagnetite-ilmenite, plagioclase (An70–40), augite, hypersthene. As a consequence of the cationic leaching, the lower mobility of silica and aluminium and the enrichment in sodium, residual altered dioritic rocks present a retromorphic mineral assemblage evolving down to boundary conditions of the greenchist-amphibolite facies (450°C). Fe, Mg and Ca are carried in cationic form associated with Cl− anions, toward cooler rocks where they are precipitated. The deposition (between 550 and 450°C) of magnetite, followed iron-mineralization paragenesis, and occurred in fractured zones located both in altered diorites and contact andesites.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-1041
    Keywords: antimineralocorticoid drugs ; RU 28318 ; spirolactone ; furosemide ; 9α-fluorohydrocortisone ; aldosterone infusion ; hypermineralocorticism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The antimineralocorticoid effect of a single dose of RU 28318, has been assessed in healthy men with exogenous or endogenous hypermineralocorticism. For exogenous hypermineralocorticism induced by ingestion of 9α-fluorohydrocortisone (9α-FHC) and aldosterone infusion, RU 28318 100 mg (9α-FHC ingestion) or 200 mg (aldosterone infusion) was administered, and its effect compared with identical doses of spironolactone or a placebo. For endogenous hypermineralocorticism induced by ingestion of furosemide, RU 28318 100 and 300 mg was tested in comparison with 100 mg spironolactone or placebo. In all 3 studies, both RU 28318 and spironolactone significantly raised the urinary Na/K ratio when compared to placebo administration. No significant difference was apparent between RU 28318 and spironolactone. Thus, a single dose of RU 28318 in man has an antimineralocorticoid effect identical to those produced by the identical molar dose of spironolactone. In addition, the results show that furosemide-induced hyperaldosteronism constitutes a simple and reproducible test for assessing the antimineralocorticoid effect of a drug.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-1041
    Keywords: hypertension ; captopril ; nifedipine ; plasma renin activity ; aldosterone ; vasopressin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In a single-dose crossover study Captopril (SQ 14225), 1 mg/kg body weight, and Nifedipine (Bay a 1040) 20 mg were administered orally to 12 hospitalized patients with essential hypertension (Stage 1 or 2, W. H. O.). Both drugs significantly reduced blood pressure, but each dose acted differently: the mean maximum arterial pressure reduction was faster and greater with Nifedipine than with Captopril: −23±2% at 37±15 min and −17±1% at 86±25 min, respectively. Captopril inhibited angiotensin II and aldosterone production, but did not accelerate heart rate or stimulate vasopressin release. Nifedipine stimulated vasopressin release and increased heart rate, but the renin angiotensin aldosterone system was not significantly affected. The blood pressure reduction was related to the initial level of activation of the renin angiotensin system only for Captopril. The blood pressure reduction induced by one drug was not related to that produced by the other in the same patient.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 49 (1995), S. 193-201 
    ISSN: 1432-1041
    Keywords: Renal function ; Prostaglandins ; Flosulide ; non-steroidal anti-inflammatory drug ; renin-angiotensin-aldosterone ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Two double-blind, placebo-controlled, balanced cross-over studies were carried out successively in 8 male normotensive volunteers to investigate the acute and chronic effects of two doses of a novel non-steroidal anti-inflammatory drug flosulide (5 mg b.d. and 25 mg b.d.), on the renin-angiotensin-aldosterone system, linking this to changes in the urinary excretion of prostaglandins. Plasma renin and aldosterone were determined on Days 2 and 9, with the subject supine, after 1 h of rest in the sitting position following 1 h of walking, and 3 h after oral intake of 40 mg furosemide, also in the sitting position. Twenty-four hour urine samples were collected on Days 1 and 8 for the measurement of the electrolytes, aldosterone pH1 and the urinary prostaglandins PGE2, PGF2α, 6-keto-PGF1α and TxB2. Results: After the first day of treatment with 25 mg b.d. flosulide, the increase in body weight was close to significance (0.86 vs -0.08 kg with placebo). A dose-and time-dependent decrease in both active and inactive plasma renin were observed, whereas the fall in plasma and urinary aldosterone was statistically significant only after the higher dose of flosulide. These changes in the renin-angiotensin-aldosterone system were observed in the absence of oedema. Two out of eight volunteers experienced a strong and immediate reduction in the excretion of prostaglandins but overall the two doses tested did not produce a statistically significant inhibition in renal prostaglandins, especially following repeated dosing. The inhibitory effect of flosulide on renal prostaglandin synthesis was found to be less pronounced after repeated treatment, as documented on Day 9 by the lower inhibition of 6-keto-PGF1α and TxB2. Conclusion: These two studies in normal volunteers, in spite of some methodological limitations, were helpful in order to select doses of flosulide which should be effective and safe in patients during Phase II trials, by examining the inhibitory effect of the drug on renin synthesis and renal prostaglandin synthesis.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0992-7689
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract HF radar observations of mid-latitude sporadic-E irregularities carried out with the Valensole radar in South France are compared with simultaneous ionosonde measurements underneath the irregularity zones. In a previous study of Valensole radar data, it has been shown that HF backscatter from the night-time mid-latitude E region is usually associated with largescale wave-like modulations. To obtain more information on the geophysical conditions prevailing during backscatter events, a new experiment was performed which also included a vertical ionosonde beneath the scattering region. The data to be presented here are from two periods when radar scattering appeared simultaneously with large variations in the virtual height and the Doppler velocity of F-layer reflected echoes measured with the vertical ionosonde, indicating very clearly the passage of atmospheric gravity waves (AGWs). The effect of the atmospheric waves on the sporadic-E layer is not always as marked as it is in the F region. In the first event, the passage of the AGWs is accompanied by an upward followed by a downward movement of the Es-layer. The apparent descending movement of the Es-layer from 135 to 110km in less than 10 min corresponded to a positive (downward) Doppler velocity of 35 m/s measured by the vertical ionosonde, and was accompanied by a range variation in the radar scattering region with a negative rate of about 90–110 m/s. In the second event, the Es-layer is not as strongly disturbed as in the previous one, but, nevertheless, the range variations of the scattering region can still be associated with height fluctuations of the Es-layer.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 94 (1991), S. 1875-1881 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The vibrational relaxation of ozone in O3–O2 and O3–N2 mixtures has been studied by means of a time-resolved infrared double resonance technique using two CO2 lasers. The collisional deexcitation of the first excited states of the stretching modes including the V–V transfer processes to the bending mode has been directly observed allowing the rate constants to be measured as a function of the O3 mole fraction in the mixtures. Finally, the rate coefficients for the intermode transfer (ν1, ν3)→ν2 and for the deexcitation from the ν2 state have been derived.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 92 (1990), S. 4212-4221 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Vibrational energy transfer processes in pure ozone have been studied by means of a time-resolved infrared double-resonance technique using two CO2 lasers. The intermode transfer between the Coriolis-coupled ν1 and ν3 modes has been observed for the first time and its rate constant measured. The near-resonant vibrational energy transfer populating the ν2+ν3 state has been also directly observed, as well as the vibrational deexcitation of the ν1 and ν3 states including the transfer process to the ν2 mode and the direct V-T,R processes. From a kinetic analysis of the vibrational relaxation, a numerical model was formulated allowing by comparison to the experiments to determine the rate coefficients for the processes. A rate coefficient of 2.4×106 s−1 Torr−1 was obtained for the intermode transfer between the Coriolis coupled ν1 and ν3 modes. Also a rate coefficient of 7×105 s−1 Torr−1 was derived for the process populating the ν2+ν3 state. The rate coefficient corresponding to the intermode transfer from ν1 and ν3 to ν2 was found to be (2800±500) s−1 Torr−1, a value clearly smaller than that obtained in previous studies. Finally the direct deexcitation from the ν1 and ν3 states, not taken into account in previous works, was found to be rather efficient, its rate coefficient being not negligible (∼600 s−1 Torr−1) as compared to the deexcitation coefficient from the ν2 state which was found equal to (2250±300) s−1 Torr−1.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    BBA - Enzymology 569 (1979), S. 202-210 
    ISSN: 0005-2744
    Keywords: (Human) ; Amniotic fluid ; Pepstatin ; Renin activation
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    BBA - Enzymology 523 (1978), S. 485-493 
    ISSN: 0005-2744
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
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