3 research outputs found

    Characterization of Hardness and Elastic Modulus of a Pharmaceutical Material for Multiple Crystal Orientations

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    Nanoindentation has made it possible to test material properties of extremely brittle molecular crystals, which include many pharmaceuticals. An antifungal, griseofulvin, is tested to determine differences in hardness and elastic modulus for different crystal orientations. Hardness and elastic modulus are determined by nanoindentation on single crystals that are rotated in 15° intervals. There are differences in hardness at rotation degrees of 45°, 60°, and 75° from the 0° orientation and differences in elastic modulus at rotation degrees of 15°, 60°, and 75° from the 0° orientation. It is also found that the elastic modulus and hardness values of the 75° rotation are only similar to the 60° rotation. Griseofulvin displays anisotropy in hardness and elastic modulus, which implies that different crystal rotations activate different slip systems. Further work is needed to correlate rotation angle with the crystal structure as well as confirm these findings on another crystal

    Use of Sentinel Surveillance and Geographic Information Systems to Monitor Trends in HIV Prevalence, Incidence, and Related Risk Behavior among Women Undergoing Syphilis Screening in a Jail Setting

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    Innovative methods are needed to systematically track the HIV epidemic and appropriately target prevention and care programs in vulnerable populations of women. We conducted sentinel surveillance among women entering the jail system of San Francisco from 1999 to 2001 to track trends in HIV incidence, HIV prevalence, and related risk behavior. Using geographic information software (GIS), we triangulated findings to examine the spatial distribution of risk and disease. A total of 1,577 female arrestees voluntarily screened for sexually transmitted diseases at intake were included. HIV incidence, estimated using the serologic testing algorithm for recent HIV seroconversion (STARHS), was 0.4% per year (95% confidence interval [95%CI] = 0.1–2.1). HIV prevalence was 1.8% (95%CI = 1.1–2.4). HIV infection was independently associated with age 30 to 39 years compared to all other ages, African-American race/ethnicity vs. non-African-American, and recent injection drug use. Maps showed that the communities in which arrested women reside are also those with the highest concentrations of newly detected female HIV cases, AIDS cases, and clients of substance use programs. The combined strategy of using sentinel surveillance in the jail setting and GIS to map the spatial distribution of disease provides a useful tool to identify patterns of risk in hard-to-reach, vulnerable populations of women
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