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1.
G Davi P Alessandrini A Mezzetti G Minotti T Bucciarelli F Costantini F Cipollone GB Bon G Ciabattoni C Patrono 《Canadian Metallurgical Quarterly》1997,17(11):3230-3235
F2-isoprostanes are bioactive prostaglandin (PG)-like compounds that are produced from arachidonic acid through a nonenzymatic process of lipid peroxidation catalyzed by oxygen free-radicals. 8-Epi-PGF2 alpha may amplify the platelet response to agonists, circulates in plasma, and is excreted in urine. We examined the hypothesis that the formation of 8-epi-PGF2 alpha is altered in patients with hypercholesterolemia and contributes to platelet activation in this setting. Urine samples were obtained from 40 hypercholesterolemic patients and 40 age- and sex-matched control subjects for measurement of immunoreactive 8-epi-PGF2 alpha. Urinary excretion of 11-dehydro-thromboxane (TX) B2, a major metabolite of TXA2, was measured as an in vivo index of platelet activation. Low-dose aspirin, indobufen, and vitamin E were used to investigate the mechanism of formation and effects of 8-epi-PGF2 alpha on platelet activation. Urinary 8-epi-PGF2 alpha was significantly (P = .0001) higher in hypercholesterolemic patients than in control subjects: 473 +/- 305 versus 205 +/- 95 pg/mg creatinine. Its rate of excretion was inversely related to the vitamin E content of LDL and showed a positive correlation with urinary 11-dehydro-TXB2. Urinary 8-epi-PGF2 alpha was unchanged after 2-week dosing with aspirin and indobufen despite complete suppression of TX metabolite excretion. Vitamin E supplementation was associated with dose-dependent reductions in both urinary 8-epi-PGF2 alpha and 11-dehydro-TXB2 by 34% to 36% and 47% to 58% at 100 and 600 mg daily, respectively. We conclude that the in vivo formation of the F2-isoprostane 8-epi-PGF2 alpha is enhanced in the vast majority of patients with hypercholesterolemia. This provides an aspirin-insensitive mechanism possibly linking lipid peroxidation to amplification of platelet activation in the setting of hypercholesterolemia. Dose-dependent suppression of enhanced 8-epi-PGF2 alpha formation by vitamin E supplementation may contribute to the beneficial effects of antioxidant treatment. 相似文献
2.
What predicts psychological resilience after disaster? The role of demographics, resources, and life stress. 总被引:1,自引:0,他引:1
Bonanno George A.; Galea Sandro; Bucciarelli Angela; Vlahov David 《Canadian Metallurgical Quarterly》2007,75(5):671
A growing body of evidence suggests that most adults exposed to potentially traumatic events are resilient. However, research on the factors that may promote or deter adult resilience has been limited. This study examined patterns of association between resilience and various sociocontextual factors. The authors used data from a random-digit-dial phone survey (N = 2,752) conducted in the New York City area after the September 11, 2001, terrorist attack. Resilience was defined as having 1 or 0 posttraumatic stress disorder symptoms and as being associated with low levels of depression and substance use. Multivariate analyses indicated that the prevalence of resilience was uniquely predicted by participant gender, age, race/ethnicity, education, level of trauma exposure, income change, social support, frequency of chronic disease, and recent and past life stressors. Implications for future research and intervention are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
3.
In high-resolution radars the constancy of the probability of false alarms (CFAR) is a difficult requirement, owing to the uncertainty of the clutter probability density function. The behaviour of an adaptive thresholding circuit is examined in Weibull assumptions, showing that a good CFAR can be obtained in a proper range of distribution shape factors. 相似文献
4.
Measurements of radar clutter using high-resolution systems show that clutter echoes cannot be modelled as Gaussian-distributed. A log-normal distribution is assumed and single-pulse detection performances are evaluated according to the Marcum-Swerling approach as well as the signal losses with respect to the Gaussian case. 相似文献
5.
Louis L. Bucciarelli Jr. 《Solar Energy》1979,23(4):277-288
Variations in the current-voltage characteristics of photovoltaic cells can lead to significant power loss “due to mismatch” when the cells are connected together in a network. This study explores how this mismatch loss depends on variations in max-power current and max-power voltage from cell to cell. An analysis of a series string is first performed. Losses in a parallel string are also determined. Estimates of mismatch losses in more complex arrays are then obtained. In addition to generally excellent comparison with several numerical studies, results show that, for a series string, there exists a critical magnitude of deviation in cell max-power current beyond which the power loss due to mismatch is sensitive to both the number of cells placed in series and the shape of the probability density function defining variations in max-power current. This critical level also depends on the cell fill-factor. 相似文献
6.
M Cattaneo MY Tsai P Bucciarelli E Taioli ML Zighetti M Bignell PM Mannucci 《Canadian Metallurgical Quarterly》1997,17(9):1662-1666
Hyperhomocysteinemia is a frequent risk factor for deep-vein thrombosis. A common mutation (C677T) in the gene encoding for methylenetetrahydrofolate reductase (MTHFR) is responsible, in the homozygous state, for decreased enzyme activity and mild hyperhomocysteinemia and is associated with increased risk for cardiovascular disease. We studied the prevalence of C677T MTHFR in 77 patients with deep-vein thrombosis and in 154 age- and sex-matched healthy control subjects. In the same individuals, we also evaluated the frequency of the coexistence of C677T MTHFR with mutant factor V:Q506, a common risk factor for deep-vein thrombosis. Sixteen patients (20.8%) and 35 control subjects (22.7%) were homozygous for the C677T MTHFR mutation (odds ratio [OR] = 0.8, 95% confidence interval [CI] = 0.4-2.0). Sixteen patients (20.8%) and 4 control subjects (2.6%) had factor V:Q506; of them, 10 patients and 3 control subjects had isolated factor V:Q506 (adjusted OR = 6.3, 95% CI = 1.6-25.3) and 6 patients and 1 control subject also had C677T MTHFR (adjusted OR = 17.3, 95% CI = 2.0-152.9). The OR for the coexistence of the two mutations was 65% to 75% higher than the expected joint effect calculated by either an additive (OR = 6.0) or multiplicative (OR = 4.4) model. The homozygous C677T mutation of MTHFR per se is not a risk factor for deep-vein thrombosis but increases the risk associated with factor V:Q506. Due to the high prevalence of C677T MTHFR, it is likely that previous studies, which did not look for this mutation, overestimated the relative risk of thrombosis associated with factor V:Q506 alone. 相似文献
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Five cyanotic newborn infants underwent cardiac catheterization between 8 and 36 hours of age with a tentative diagnosis of cyanotic congenital heart disease. All had normal cardiovascular anatomy. Cyanosis was the result of persistence of fetal cardiopulmonary circulation with right-to-left shunting across the ductus arteriosus. In all infants, cyanosis resolved spontaneously and the infants survived without sequelae. Admission chest roentgenograms of all infants showed marked hyperinflation of the lungs. Except for severe hypoxemia, the clinical presentation, chest films, and course of illness of these infants were consistent with transient tachypnea of the newborn. It is proposed that an increase in pulmonary vascular resistance, due to hyperinflation of the lungs, was the mechanism which reopened the fetal cardiopulmonary circulatory channels and produced hypoxemia, and that these infants suffered from a rare manifestation of a usually benign newborn respiratory condition. Further, given these pathophysiologic mechanisms, the use of continuous transpulmonary pressure gradients in the management of such infants would be contraindicated. 相似文献
9.
Louis L. Bucciarelli Jr. 《Solar Energy》1986,36(1)
This paper extends a method previously developed by the author for evaluating the probability of loss-of-power of stand-alone photovoltaic solar energy systems. As before, the method treats the energy capture, storage and dispersement process as a random walk in the storage domain. Correlation in day-to-day levels of solar insolation is now taken into account in the derivation of an expression for the probability of depleting storage. 相似文献
10.
V Schmid C Baader A Bucciarelli S Reber-Müller 《Canadian Metallurgical Quarterly》1993,155(2):483-496
Striated muscle tissue of jellyfish was isolated with its adhering extracellular matrix (ECM) and cultured. Without further treatment the cultured muscle cells maintain their differentiated state. If, however, the isolated tissues are combined with cell-free ECM from the jellyfish or its polyp, DNA replication and proteolytic activity are induced followed by transdifferentiation into RF-amide-positive nerve cells. Changes in the mechanochemical interactions between the cells and the grafted ECM seem to induce the signals which lead to transdifferentiation. If the isolates are combined with small floating pieces of ECM most cells will leave their own ECM and overgrow the ECM graft. All cells in the combinations will then transdifferentiate. If the isolates are grafted onto large pieces of ECM kept permanently stretched on glass, a majority of cells will migrate onto the grafted ECM where they form a flat monolayer. In this case, however, DNA replication and transdifferentiation occurs mainly in those cells which have remained on or near their own ECM. Labeling experiments with [3H]-thymidine demonstrate that initiation of DNA replication occurs first in those cells which bridge from the native ECM to the grafted ECM. On the other hand inhibition of DNA replication and transdifferentiation is generally suppressed whenever tissues are allowed to form a monolayer of well-stretched cells. From these observations we conclude that mechanochemical interactions between the muscle cells and their substrate are responsible for both activation and inhibition of DNA replication and transdifferentiation. 相似文献