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41.
S Merino A Aguilar JM Tomás R Bonet MJ Martinez D Simón-Pujol F Congregado 《Canadian Metallurgical Quarterly》1997,22(5):315-320
1. We investigated the effect of exercise on plasma adrenomedullin, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) concentrations and studied the relationship between these peptides and haemodynamic parameters in nine patients with old myocardial infarction (MI) and in eight normal subjects. 2. The exercise protocol consisted of two fixed work loads (40 and 80 W) for 4 min each and venous blood samples were taken at rest, during each exercise stage and after exercise while monitoring the mean arterial pressure (MAP) and heart rate (HR). In MI, pulmonary arterial pressure (PAP), pulmonary capillary wedge pressure (PCWP), left ventricular end-diastolic pressure (LVEDP) and cardiac output (CO) were measured throughout exercise. 3. Adrenomedullin levels did not significantly increase with exercise. Adrenomedullin levels correlated with PAP and PCWP at rest (P < 0.05). Atrial natriuretic peptide levels correlated with PAP, PCWP and LVEDP throughout exercise (P < 0.05) but, on multiple regression analysis, PCWP correlated only with ANP (P < 0.01). Brain natriuretic peptide levels correlated with LVEDP throughout exercise (P < 0.01) and its increment correlated closely with basal BNP levels at rest (P < 0.01). 4. These results suggest that adrenomedullin does not respond to the acute haemodynamic changes of exercise, whereas ANP responds to it and PCWP is the major stimulus factor. Brain natriuretic peptide responds to exercise in proportion to the basal synthesis of BNP in patients with left ventricular dysfunction and LVEDP may play a role in increasing BNP during exercise. 相似文献
42.
Sebastián Bruque-Cámara Alfonso Vargas-Sánchez M. Jesús Hernández-Ortiz 《欧洲信息系统杂志》2004,13(2):133-146
The aim of this paper is to propose new organizational factors that might explain the differences in the extent and the speed of IT adoption. With this in mind, we carried out an analysis of 16 cases in the pharmaceutical distribution sector in Spain. The results indicate that there are certain intangible assets that favour the introduction and development of IT. Among these are a frank and fluid communication between departments and members of the organization, low levels of conflict, the explicit support of top management towards IT adoption and learning and creative skills of IT-staff. In addition to these factors, we found others that we propose as catalysts of IT adoption. Among these we might mention the special relationship between the member-clients and the company in the case of cooperative firms. 相似文献
43.
E. Stenitzer H. Diestel Th. Zenker R. Schwartengräber 《Water Resources Management》2007,21(9):1567-1584
The performance of the water balance and crop growth model SIMWASER to estimate the water supply of a lawn by capillary rise
from shallow ground water was investigated by using lysimeter measurements with a sandy and a clayey soil. Moreover the robustness
of the model was evaluated by running it either with measured hydraulic soil parameters or with estimated pedotransfer functions
(PTFs) derived from texture and bulk density. Simulations were performed for the years 1996–1998 with input data from the
lysimeter station Berlin-Dahlem (Germany) for lysimeters containing undisturbed sandy or clayey soil monoliths, with groundwater
at 135 cm depth. Simulated evapotranspiration and percolation/capillary rise were in good agreement with the measured data
for all variants, while simulated soil water storage was acceptable only for the variants using hydraulic soil data based
on laboratory measurements or using PTFs derived from known soil class and bulk density. PTFs based on mean total pore volume
of the respective soil classes yielded soil water storages which were evidently too high; therefore they should be used with
care and must be avoided at all in simulating the soil water balance of arid sites with shallow groundwater. 相似文献
44.
A. V. Räisänen W. R. McGrath D. G. Crete P. L. Richards 《Journal of Infrared, Millimeter and Terahertz Waves》1985,6(12):1169-1189
Several scaled models have been used to determine the contributions of various waveguide mount parameters to the embedding impedance of a mm-wave SIS mixer. Measured effects of waveguide height, substrate orientation and width, junction location, lead inductance and RF-filter impedance are presented and discussed. 相似文献
45.
46.
Summary ESCA is used to characterize ion beam irradiated P(p-ClPhMA)-samples. The results show a chlorine abstraction. The experimental
findings are in accordance with a recently proposed model for a crosslinking mechanism of halogenated aromatic polymers. 相似文献
47.
The next generation of video tapes will use evaporated thin films with their superior properties such as recording density, output level, frequency characteristics and signal-to-noise ratio. This paper describes the metal layer formation by a simple model for the growth of microcolumns at oblique incidence deposition. The most relevant process parameters are discussed. The layout of a production coater is described. 相似文献
48.
49.
D. Y. C. Lie A. Vantomme F. Eisen T. Vreeland M. -A. Nicolet T. K. Carns K. L. Wang B. Holländer 《Journal of Electronic Materials》1994,23(4):369-373
We compare both the strain and damage that 100 keV Si irradiation at room temperature introduces in pseudomorphic and relaxed
GexSi1−x films grown on Si(100) substrates. The ion range is such that the Si/GexSi1−x interface is not significantly damaged. The amount of damage produced in pseudomorphic and relaxed GexSi1−x layers of similar x for irradiation doses up to 2.5 × 1014 Si/cm2 is the same, which proves that a pre-existing uniform strain does not noticeably affect the irradiation-induced damage. However,
the irradiation-induced strain does depend on the pre-existing strain of the samples. Possible interpretations are discussed.
On leave from Inst. voor Kern en Stralingsfysika, Catholic University of Leuven, Belgium. 相似文献
50.