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141.
The hot hardness of polycrystalline single-phase α- or β- sialon ceramics declines with increasing temperature, but the measured Vickers hardness (HV1) at 1100°C is still about 1550 and 1300 for the α-sialon and the low-substituted β-sialon materials, respectively. The hardness of 'composite'β- or α-β-sialon ceramics containing a high volume fraction of glassy phase is lower at all temperatures and drops significantly above about 900°C.  相似文献   
142.
This purpose of this article is to explore differences by gender and school grade in patterns of association among social influences and tobacco use. Data from the 1999 (N = 15,038) and 2000 (N 35,828) National Youth Tobacco Survey (American Legacy Foundation, 1999, 2000), a nationally representative, repeated cross-sectional survey, were used in the analysis. The authors compared effects on adolescent smoking. Direct paths from social environment to current smoking increased from middle school to high school. Indirect paths with social image mediating this relationship revealed a smaller increase. The pattern was constant across subsamples. Social image of smokers mediated the influence of social environment on adolescent smoking. Social image had a greater effect on smoking among middle school boys and high school girls. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
143.

Background  

To explore the point prevalence of the risk of malnutrition and the targeting of nutritional interventions in relation to undernutrition risk and hospital volume.  相似文献   
144.
The principal objective of this study was to determine if Campylobacter jejuni genotyping methods based upon resolution optimised sets of single nucleotide polymorphisms (SNPs) and binary genetic markers were capable of identifying epidemiologically linked clusters of chicken-derived isolates. Eighty-eight C. jejuni isolates of known flaA RFLP type were included in the study. They encompassed three groups of ten isolates that were obtained at the same time and place and possessed the same flaA type. These were regarded as being epidemiologically linked. Twenty-six unlinked C. jejuni flaA type I isolates were included to test the ability of SNP and binary typing to resolve isolates that were not resolved by flaA RFLP. The remaining isolates were of different flaA types. All isolates were typed by real-time PCR interrogation of the resolution optimised sets of SNPs and binary markers. According to each typing method, the three epidemiologically linked clusters were three different clones that were well resolved from the other isolates. The 26 unlinked C. jejuni flaA type I isolates were resolved into 14 SNP-binary types, indicating that flaA typing can be unreliable for revealing epidemiological linkage. Comparison of the data with data from a fully typed set of isolates associated with human infection revealed that abundant lineages in the chicken isolates that were also found in the human isolates belonged to clonal complex (CC) -21 and CC-353, with the usually rare C-353 member ST-524 being especially abundant in the chicken collection. The chicken isolates selected to be diverse according to flaA were also diverse according to SNP and binary typing. It was observed that CC-48 was absent in the chicken isolates, despite being very common in Australian human infection isolates, indicating that this may be a major cause of human disease that is not chicken associated.  相似文献   
145.
A marine macroalga, Ulva lactuca L., was used as a substrate to compare the kinetics of palladium (Pd) and platinum (Pt) removal from seawater. This work indicates that, while the equilibrium behaviors of Pd and Pt are in many respects similar, their kinetic behaviors are quite distinct. The removal of both Pt(II) and Pt(IV) from seawater by U. lactuca is slower than the removal of Pd(II) by approximately an order of magnitude. Relative Pd and Pt removal rates are strongly influenced by system hydrodynamics. Under quiescent conditions, lambda(Pd)/lambda(Pt), the ratio of Pd and Pt removal rates, is 7 +/- 2, whereas under turbulent conditions lambda(Pd)/lambda(Pt) can be as large as 27. These observations suggest that the disparate kinetic behaviors of Pd and Pt may produce considerable differences in the environmental dispersion of these elements.  相似文献   
146.
Magnetic resonance imaging (MRI) reveals cardiac signal intensity changes in patients with acute myocarditis; however, the natural history of these changes and their relationship to individual outcomes are unknown. The relationship of MRI findings to long-term outcome was studied by serial MRI studies in 16 patients with acute myocarditis who were followed for 30±4 (SE) months. Myocardial contrast enhancement was monitored using contrast-enhanced T1-weighted fast spin-echo images. Left ventricular ejection fraction was measured with gradient-echo sequences. Clinical symptoms were scored. The results were compared to a control group of 26 age-matched, healthy volunteers. Myocardial contrast enhancement, which was markedly increased in the early course of the disease, decreased at 4 weeks and remained within the normal range in most patients after 30 months. Contrast enhancement 4 weeks after onset of symptoms was predictive for the functional and clinical long-term outcome. Contrast-enhanced MRI may be a useful, noninvasive tool for long-term follow-up of patients with acute myocarditis. Furthermore, relatively early MRI findings may predict longer-term outcomes. Electronic Publication  相似文献   
147.
Measurements of the heat capacity of methylphosphonyl difluoride (CH3POF2), methyl phosphonyl dichloride (CH3POCl2), and methylphosphonyl chlorofluoride (CH3POClF) were made from about 15 to 335 °K by means of an adiabatic calorimeter. These highly reactive and toxic substances were purified in a completely closed glass apparatus by combining slow crystallization and fractional melting procedures. The purities determined by the freezing-curve method are shown to be generally in agreement with those values obtained by the calorimetric method. From the results of the heat measurements, the triple-point temperature, heat of fusion, and their corresponding estimated uncertainties were found to be, respectively, 236.34±0.05 °K and 11,878±12 J/mole for CH3POF2, 306.14± 0.02 °K and 18,076±15 J/mole for CH3POCl2, and 250.70± 0.20 °K and 11,853±30 J/mole for CH3POClF. Triple-point temperatures obtained by the freezing-curve method are in agreement with the above values. A table of smoothed values of heat capacity, enthalpy, enthalpy function, entropy, Gibbs free energy, and Gibbs free energy function from 0 to 335 °K was obtained from the data. The entropy and its corresponding estimated uncertainty for CH3POF2, CH3POCl2, and CH3POClF in their respective condensed phase at 298.15 °K and saturation pressure was found to be 208.3± 0.3, 164.8± 0.3, and 216.4± 0.4 J/deg mole, respectively. The entropies in the gaseous state at 298.15 °K and 1 atm pressure were found to be 312.7±3, 339.7±3, and 335.0±3 J/deg mole, respectively.  相似文献   
148.
This review of the literature examines the role of language and culture in the mental health treatment of Hispanic clients. Several innovative approaches including the use of dichos and cuento therapy are described that incorporate linguistic and cultural traits in treatment. The article proposes that the assessment of such factors as language proficiency, level of acculturation, and the degree to which cultural expressions represent symptomatology should be considered in the development of an effective treatment plan. The process of acculturation is presented as a critical dimension influencing language, cultural beliefs, and mental health. Recommendations are made for future research on issues relating to the use of language switching and language mixing in therapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
149.
Performance appraisal is used in organizations for a variety of purposes. However, little empirical research has been conducted to determine (a) the extent to which performance appraisal is used for each of several purposes in industry, (b) the extent to which appraisal data may be used for multiple and possibly conflicting uses within the same organization, and (c) organizational correlates of these uses. A survey questionnaire designed to answer these questions was mailed to 243 members of Division 14 of the American Psychological Association who were employed in industry. A factor analysis of the 106 completed questionnaires indicated four general uses of information from performance appraisals. The use of performance appraisal to simultaneously make distinctions between and within individuals is common. Canonical correlation analyses indicated that organizational characteristics were significantly related to uses of performance appraisal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
150.
Nonionic, cationic and anionic surfactants, derivatives ofcis-13-docosenoic acid (erucic acid), have been prepared and characterized, and their performance has been evaluated and compared with the corresponding derivatives of fatty acids with shorter alkyl chain length. Nonionic erucic acid ethoxylates give a solution behavior anticipated from the hydrophilic-lipophilic balance of the molecule; however, the increased molecular size as compared to ordinary surfactants results, e.g., in higher temperature stability of the surfactant aggregates. Anomalous solution behavior was found and investigated for anionic surfactants, triethanolammonium salts of erucic acid, and some shorter homologues. The effects are discussed in terms of the acid-base equilibria of the alkanolammonium counterion and the acid, together with effects due to the molecular size of the counterion.  相似文献   
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