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991.
The surface of polycrystalline iron covered by segregated arsenic, phosphorus and sulphur was analysed in a combined electron spectroscopic study by means of Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). The saturation coverage of arsenic at 1033 K was determined as 0.33±0.02 monolayer. Sulphur, arsenic and phosphorus segregate in competition. A relation giving the surface coverage from the XPS intensity of adsorbed element is deduced from the experiments and is also calculated. Experimental and calculated values are found to be in relatively good agreement.Visiting Scientist from W. Trzebiatowski Institute of Low Temperature and Structure Research PAS, P.O. Box 937, 50-950 Wroclaw, Poland. 相似文献
992.
F Ramalho J Velosa A Costa A Baptista MC de Moura 《Canadian Metallurgical Quarterly》1993,6(5):187-191
In order to evaluate the interference of hepatitis delta virus (HDV) in hepatitis B viral particle (HBsAg, HBcAg) expression in the liver of chronic HDV patients, 39 and 81 liver biopsies of HBsAg carriers seropositive for anti-HDV and anti-HDV negative controls, respectively, were studied. HBcAg was positive in 16.7% of the HBeAg-positive patients with HDAg in the liver and in 91,4% of controls. In contrast, in HBeAg- and anti-HDV negative patients the intrahepatic expression of HBcAg was detected in 32.6%. In anti-HDV negative patients the HBcAg liver expression correlated significantly with the HBeAg in serum (p < 0.00001). The distribution of HBcAg was exclusively cytoplasmatic in 30% of HDV-infected patients but mixed nuclear and cytoplasmic in 38.3% of the controls. The nuclear expression of HBcAg was decreased in chronic HDV infection. HBsAg was positive in 70.3% of patients who were anti-HDV positive and in 82.3% of controls. The membranous expression of HBsAg was detected less frequently in HDV-infected patients (p < 0.05) than in controls, while associated with HBeAg in serum of HBV carriers without HDV superinfection (p < 0.00001). The prevalence and the HBsAg cytoplasmic expression was not different for the chronic HDV infection or controls. Our results show: 1) decreased intrahepatic expression of HBcAg and membranous HBsAg in HBV carriers superinfected with HDV, suggesting decreased HBV replication in the liver of these patients. 2) the changing of HBcAg and HBsAg expression in the liver of HDV-infected patients, suggest not so much a decrease but rather a modulation in HBV replication. 相似文献
993.
South America's Pantanal, the world's largest tropical wetland, contains hundreds of thousands of geochemically diverse lakes, ranging from dilute to brackish to saline in composition. These lakes form the backbone of the habitat that supports the highly diverse flora and fauna of the Pantanal, yet the natural processes that create and destroy them are largely unknown. The quantities and types of lakes in the Pantanal and their spatial distribution are therefore essential, but missing information required to understand the dynamics of the Pantanal ecosystem.RADARSAT S1 and S7, and JERS-1 imagery were integrated with field measurements of water geochemistry and characteristics of emergent aquatic vegetation for fresh and brackish lakes of the Nhecolândia region of the Brazilian Pantanal. A supervised classification was used to classify forest, pasture, bare soil, and lakes. A mask is then applied to produce an image of only lakes. The radar backscattering values were found to have a strong relationship with the emergent aquatic plant assemblages of the lakes—S1 imagery was the most useful. The plant assemblages, in turn, were observed to be strongly controlled by the total dissolved solids (TDS) and pH of the lakes. The relationships between backscattering values, plant assemblages, and geochemistry were then exploited to map the type and distribution of the lakes in the study area.Threshold rules were used to perform Level 1 and Level 2 classifications of the lakes. For the Level 1 classification, the σo values of RADARSAT S1 effectively separated brackish (10,000 > TDS > 1000 mg/kg) from fresh water lakes (TDS < 1000 mg/kg) with a total accuracy of 91%. For the Level 2 classification, the σo values of RADARSAT S1 effectively separated lakes into three geochemical groups: brackish (10,000 > TDS > 1000 mg/kg), hard with only Typha (1000 > TDS > 100 mg/kg), and fresh water lakes (TDS mg/kg < 100 mg/kg) with a total accuracy of 83%. Considering that the area is very remote and the lakes are very numerous, this may be the most feasible way to map lake type in the Pantanal. 相似文献
994.
McCrae Robert R.; Zonderman Alan B.; Costa Paul T.; Bond Michael H.; Paunonen Sampo V. 《Canadian Metallurgical Quarterly》1996,70(3):552
Despite the empirical robustness of the 5-factor model of personality, recent confirmatory factor analyses (CFAs) of NEO Personality Inventory (NEO-PI) data suggest they do not fit the hypothesized model. In a replication study of 229 adults, a series of CFAs showed that Revised NEO-PI scales are not simple-structured but do approximate the normative 5-factor structure. CFA goodness-of-fit indices, however, were not high. Comparability analyses showed that no more than 5 factors were replicable, which calls into question some assumptions underlying the use of CFA. An alternative method that uses targeted rotation was presented and illustrated with data from Chinese and Japanese versions of the Revised NEO-PI that clearly replicated the 5-factor structure. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
995.
Ramona María Díaz Ana María Fernndez Jorge Xiberta 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1986,36(6):273-280
The distribution equilibrium data at 25°C for the extraction of copper from aqueous solutions, containing sodium nitrate or sodium sulphate, by carboxylic acids using toluene, benzene and carbon tetrachloride as diluents have been measured. The carboxylic acids used are n-myristic, n-lauric and n-capric. The results obtained led to the conclusion that the composition of the extracted species corresponds to (CuR2.HR)2, being irrespective of both the nature of organic phase and the aqueous phase. The addition of sodium sulphate, instead of sodium nitrate, decreases the extraction efficiency due to the formation a CuSO4 ion-pair into the aqueous phase. The diluent effect has been related to the activity of the dimerised carboxylic acid in the diluent. 相似文献
996.
997.
M Cuatrecasas N Erill E Musulen I Costa X Matias-Guiu J Prat 《Canadian Metallurgical Quarterly》1998,82(6):1088-1095
BACKGROUND: Coronary stent deployment failure may be more common in clinical practice than generally appreciated. The incidence of failed deployment in routine clinical practice and the clinical sequelae have not been described. This study sought to determine the incidence and consequences of failed coronary stent deployment and to identify clinical and angiographic characteristics associated with deployment failure. METHODS AND RESULTS: A series of 1303 consecutive procedures involving attempted coronary stenting were reviewed retrospectively. Failed stent deployment was defined as failure of the stent to be either delivered to or adequately deployed at the target lesion site. Clinical records and angiograms were reviewed and qualitative coronary angiography was performed for all cases of failed deployment. Deployment was unsuccessful in 108 (8.3%) cases involving 134 stents. Stenting was attempted as a primary procedure in 40%, as bailout in 18%, and for suboptimal angioplasty in 43% of cases. In 87% of cases, attempts were made to withdraw the stent from the coronary artery. Stent retrieval was successful in 45%, peripheral embolization occurred in 38% of patients, and in 4% the stent dislodged in the left main artery. In 35% of cases, additional stent(s) were successfully deployed. Deployment failure was associated with an overall in-hospital adverse outcome in 19% of patients, including 16% urgent coronary artery bypass grafting, 5% nonfatal myocardial infarction, and 3 in-hospital deaths. At 6-month follow-up, 39% of patients had had at least 1 adverse clinical outcome of death, myocardial infarction, or repeat target lesion revascularization. CONCLUSIONS: Failure to deploy stents is a serious and relatively common problem that is associated with significant morbidity and mortality rates. Improved deployment strategies, including new stent designs, are required to improve procedural outcomes. 相似文献
998.
999.
At first new epoxy derivatives, namely glycidylimide compounds, have been prepared using benzyltrimethylammonium chloride as catalyst and epichlorohydrin in excess. Their chemical and physical properties were studied. Spectral data confirmed these new structures. Afterwards new epoxy resins have been synthesized by the reaction of diimides and their glycidyl derivatives in N,N-dimethylformamide. The physical characteristics of the obtained polymers and also their solubilities are reported. Their IR, 1H- and 13C-NMR spectra allowed to confirm the polymer structure. Thermal analysis of these compounds showed their good thermal properties. 相似文献
1000.
Forty Ss, 20 males and 20 females, observed a videotape that showed four males interacting in a social setting under four different drug conditions; coltsfoot, placebo, marijuana low dose, and marijuana high dose. The observers attempted to discriminate the level of intoxication of the four males in each condition. The observers accurately detected the level of intoxication in the high dose condition. While marijuana experienced users were more successful in detecting levels of intoxication, the sex of the observer was not significant. Behaviors used to discriminate intoxication and the implications of these results to defining intoxication are discussed. 相似文献