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Sexual stereotypes may adversely affect the health of Black men who have sex with men (MSM). Greater understanding of the nature and nuances of these stereotypes is needed. This online, survey-based study used an inductive, intersectional approach to characterize the sexual stereotypes ascribed to Black MSM by the U.S. general public, their distinctiveness from those ascribed to Black men and MSM in general, and their relative prototypicality as compared to dominant subgroups. Members of the public, recruited in 2014–2015, were randomly assigned to survey conditions that varied systematically by race (Black, White, or unspecified) and sexual orientation (gay, heterosexual, or unspecified) of a designated social group. Participants (n = 285) reported stereotypes of their assigned group that they perceived to exist in U.S. culture in an open-response format. Cross-condition comparisons revealed that, overall, Black gay male stereotypes were non-prototypical of Black men or gay men. Rather, stereotypes of Black men were more similar to Black heterosexual men and stereotypes of gay men were more similar to White gay men. Nonetheless, 11 of the 15 most frequently reported Black gay male stereotypes overlapped with stereotypes of Black men (e.g., large penis), gay men (e.g., deviant), or both (e.g., promiscuous). Four stereotypes were unique relative to both Black men and gay men: down low, diseased, loud, and dirty. Findings suggest that Black MSM face multiple derogatory sexual stereotypes, several of which are group-specific. These stereotypes are consistent with cultural (mis)representations of Black MSM and suggest a need for more accurate portrayals of existing sexual diversity within this group.  相似文献   
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A bstract — The impact resistance of a polysulphone denture base polymer has been determined, and for comparison the impact resistance was also determined of a linear poly(methyl methacrylate) and four rubber-modified methacrylate denture base polymers. When tested under mouth conditions the polysulphone had an impact resistance more than four times as high as the poly(methyl methacrylate) and about twice as high as the most impact resistant rubber-modified methacrylate. Unlike some of the other materials tested, the polysulphone did not suffer a reduction in impact resistance on extended ageing under mouth conditions.  相似文献   
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Measurements were made of the fit of gold-alloy full-crown castings produced with dry ceramic ring liners. When used with vacuum investing, these liners absorb relatively large amounts of water from the investment mix (thereby reducing its original W/P ratio) and then function as wet liners, thus increasing the investment's potential expansion and giving castings which are consistently larger than when air investing is used. With four of the five liners tested, investing in air produced many castings which were unacceptably undersized (inaccuracy worse than -0.2%). The fifth liner, an industrial material 2 mm thick, gave only one casting out of 12 which was outside this limit, although all castings were undersized to a lesser extent. Vacuum investing gave improved casting accuracy; with four of the five liners, the improvement was highly significant (p < 0.001), and with the fifth, probably significant (p < 0.05). Even with vacuum investing, however, with only two of the liners did all castings show inaccuracies within +/- 0.2%. With the other three liners, some castings (ranging from 2/10 to 7/9) had inaccuracies worse than -0.2%. With both air and vacuum investing, changing from one liner to another caused changes in relative casting accuracy which were often significant (p < 0.01) or highly significant (p < 0.001). In casting techniques where a ceramic ring liner is used, the choice of specific lining material and the choice between investing in air or under vacuum are important factors which can have a major effect on the fit of castings.  相似文献   
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Forty patients with severe bone disease and chronic renal failure were treated with 1 alpha-hydroxycholecalciferol (1 alpha-OHD3) or 1,25-dihydroxycholecalciferol (1,25(OH)2D3) for 7--49 months (total = 738 patient months). There were symptomatic, biochemical and radiographic improvements in the majority of patients (greater than 70 per cent). Paired bone biopsies, taken before and during treatment in 26 patients, showed no change in bone matrix area, whereas matrix area decreased in a control group of 26 patients over the same period. There were small but consistent decreases in bone marrow fibrosis and in bone cell (osteoblast and osteoclast) counts in treated patients but not in controls. However, the proportion of patients who showed histological 'cure', in the sense of complete reversal of marrow fibrosis or excess osteoid was no greater in the treated than in the control group...  相似文献   
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Social biases among healthcare providers could limit PrEP access. In this survey study of 115 US medical students, we examined associations between biases (racism and heterosexism) and PrEP clinical decision-making and explored prior PrEP education as a potential buffer. After viewing a vignette about a PrEP-seeking MSM patient, participants reported anticipated patient behavior (condomless sex, extra-relational sex, and adherence), intention to prescribe PrEP to the patient, biases, and background characteristics. Minimal evidence for racism affecting clinical decision-making emerged. In unadjusted analyses, heterosexism indirectly affected prescribing intention via all anticipated behaviors, tested as parallel mediators. Participants expressing greater heterosexism more strongly anticipated increased risk behavior and adherence problems, which were associated with lower prescribing intention. The indirect effect via condomless sex remained significant adjusting for background characteristics. Prior PrEP education did not buffer any indirect effects. Heterosexism may compromise PrEP provision to MSM and should be addressed in PrEP-related medical education.  相似文献   
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