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排序方式: 共有1631条查询结果,搜索用时 15 毫秒
61.
MM Mashaly GP Birrenkott MM EL-Begearmi BC Wentworth 《Canadian Metallurgical Quarterly》1976,55(4):1226-1234
Progesterone and luteinizing hormone (LH) were measuured in the plasma of Large White turkey hens at frequent intervals during the ovulatory cycle and during the periods when ovulations did not occur. The hormones were quantitated at the beginning and the end of the reproductive season to follow the change in patterns and concentrations of these hormones. Radioimmunoassay procedures were used to assay both hormones. Both progesterone and LH reached a peak amount at about 8 to 2 hours before ovulation. At no time did the progesterone peak precede that of LH. On the other hand, the peak of progesterone was observed to last somewhat longer than the LH peak. Progesterone and LH concentrations demonstrated no peak during the non-ovulatory periods. The patterns of both hormones at the end of the reproductive season was about the same as at the beginning of the season, but with lower concentrations. 相似文献
62.
L Zardi LS Vincent A Barbin R Montesano GP Margison 《Canadian Metallurgical Quarterly》1977,3(3-4):183-188
DNA repair was measured in human fibroblasts, mouse C3H 10 T 1/2 fibroblsts and rat hepatocytes by the non-semi-conservative incorporation of [3H]-TdR during DNA repair synthesis using liquid scintillation techniques. Confluent monolayers of these cells grown on cover slips were exposed to split doses (125 or 250 microgram/ml) of the mutagenic and carcinogenic alkylating agent MNU and DNA repair synthesis compared with that produced by a single dose (500 microgram/ml). No significant difference in DNA repair capacity was detected in the three cell lines treated with a single dose or split doses of MNU. 相似文献
63.
After drinking a small dose of alcohol, Orientals flushed, their heart rates increased and their diastolic pressures decreased; Caucasians' skin reflectance did not change, but their heart rates and systolic blood pressures decreased. In both groups, flushing was associated with an increase in feelings of vigor. Other mood correlates depended on condition. 相似文献
64.
A method for the generation of full disk MSG (METEOSAT Second Generation) SEVIRI (Scanning-Enhanced Visible and Infrared Imager) true colour composite images is presented. The algorithm mainly uses the SEVIRI channels VIS006 (0.6 μm), NIR008 (0.8 μm) and NIR016 (1.6 μm). Only one of the full disk SEVIRI channels is located in the visible spectral region. This is channel VIS006 which covers mainly the yellow to red parts of the visible spectrum. The lack of information in the blue and green parts of the visible spectrum is compensated by using data from NASA's (National Aeronautics and Space Administration's) Blue Marble next generation (BMNG) project to fill a look-up table (LUT) transforming RGB (red/green/blue) false colour composite images of VIS006/NIR008/NIR016 into true colour images. Tabulated radiative transfer calculations of a pure Rayleigh atmosphere are used to add an impression of Rayleigh scattering towards the sunlit horizon. The resulting images satisfy naive expectations: clouds are white or transparent, vegetated surfaces are greenish, deserts are sandy-coloured, the ocean is dark blue to black and a narrow halo due to Rayleigh scattering is visible at the sunlit horizon. Therefore, such images are easily interpretable also for inexperienced users not familiar with the characteristics of typical MSG false colour composite images. 相似文献
65.
András Gergely Éva Pfeifer Imre Bertóti Tamás Török Erika Kálmán 《Corrosion Science》2011,53(11):3486-3499
High porosity and intense galvanic function related low electrolytic barrier profile and fast delamination of zinc-rich paints (ZRPs) are addressed by the utilisation of intimately structured, highly dispersed, polypyrrole (PPy) deposited alumina particles (PDAPs) embedded zinc-rich hybrid paints. The more globular but less-packed structure type PPy-contained water-solvent-prepared PDAPs-composited hybrids comprising spherical zinc pigment at 70 wt.%, provided moderate galvanic function with enhanced electrolytic barrier properties. In addition, the less globular structured but well-packed PPy-comprised aqueous ethanol-solvent-prepared PDAPs-composited hybrid coatings indicated highly efficient suppressed galvanic function and improved barrier properties, realising solid performance improvement over conventional ZRPs in immersion and salt-spray chamber tests. Furthermore, the application of highly dispersed PDAPs at a content of 3.2 wt.% while PPy incorporated into zinc-rich hybrids at 0.16 wt.% is proposed to result in emerging additional functionalities increasing long-term anticorrosive performance of ZRPs by inhibiting sacrificial and self-corrosion of zinc and scavenging oxidative radicals thereby hindering oxidative degradation of the organic binder. 相似文献
66.
67.
E Petrossian AJ Parry VM Reddy GP Akkersdijk DM McMullan L Thompson KD Hendricks-Munoz H Hallak FL Hanley JR Fineman 《Canadian Metallurgical Quarterly》1999,117(2):314-323
BACKGROUND: Children with increased pulmonary blood flow may experience morbidity as the result of increased pulmonary vascular resistance after operations in which cardiopulmonary bypass is used. Plasma levels of endothelin-1, a potent vasoactive substance implicated in pulmonary hypertension, are increased after cardiopulmonary bypass. OBJECTIVES: In a lamb model of increased pulmonary blood flow after in utero placement of an aortopulmonary shunt, we characterized the changes in pulmonary vascular resistance induced by hypothermic cardiopulmonary bypass and investigated the role of endothelin-1 and endothelin-A receptor activation in postbypass pulmonary hypertension. METHODS: In eleven 1-month-old lambs, the shunt was closed, and vascular pressures and blood flows were monitored. An infusion of a selective endothelin-A receptor blocker (PD 156707; 1.0 mg/kg/h) or drug vehicle (saline solution) was then begun 30 minutes before cardiopulmonary bypass and continued for 4 hours after bypass. The hemodynamic variables were monitored, and plasma endothelin-1 concentrations were determined before, during, and for 6 hours after cardiopulmonary bypass. RESULTS: After 90 minutes of hypothermic cardiopulmonary bypass, both pulmonary arterial pressure and pulmonary vascular resistance increased significantly in saline-treated lambs during the 6-hour study period (P <.05). In lambs pretreated with PD 156707, pulmonary arterial pressure and pulmonary vascular resistance decreased (P <. 05). After bypass, plasma endothelin-1 concentrations increased in all lambs; there was a positive correlation between postbypass pulmonary vascular resistance and plasma endothelin-1 concentrations (P <.05). CONCLUSIONS: This study suggests that endothelin-A receptor-induced pulmonary vasoconstriction mediates, in part, the rise in pulmonary vascular resistance after cardiopulmonary bypass. Endothelin-A receptor antagonists may decrease morbidity in children at risk for postbypass pulmonary hypertension. This potential therapy warrants further investigation. 相似文献
68.
Flow cytometry was used in the identification of human microsporidia belonging to the genus Encephalitozoon. Microsporidian spores of Encephalitozoon hellem, E. cuniculi, and E. intestinalis were propagated in axenic cultures of monkey kidney E6 cells, purified with Percoll, and exposed to homologous and heterologous rabbit antiserum and monoclonal antibody prepared against E. hellem spores. After reaction to goat anti-rabbit immunoglobulin G (IgG) or goat anti-mouse IgG conjugated to fluorescein isothiocyanate, fluorescence histograms from gated data on light-scatter profiles showed that rabbit anti-E. hellem serum was reactive to E. hellem spores but also had cross-reactivity to spores of E. cuniculi and E. intestinalis. On the other hand, fluorescence histograms showed that rabbit anti-E. cuniculi and rabbit anti-E. intestinalis sera were reactive with homologous spores only. Monoclonal antibody prepared against E. hellem reacted only with spores of E. hellem. Neither the polyclonal antibodies nor the monoclonal antibodies reacted with Cryptosporidium parvum oocysts. Fluorescence histograms of spores treated with 10% formalin also showed reactivity, but the number of events in the most intense peaks of fluorescence was fewer (7 to 42%, depending on species) than the number of events in the most intense peaks of fluorescence for nontreated spores. By flow cytometry, formalin-treated and nontreated spores of Encephalitozoon were identified to the species level by using gated data on light-scatter profiles and analyzing the fluorescence histograms from the indirect immunofluorescence of the spores. Once a procedure is established for the isolation of Encephalitozoon spores from clinical specimens, identification of spores by flow cytometry may be useful not only for diagnosis but also for epidemiologic studies. 相似文献
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