281 research outputs found

    Perceived Barriers Preventing and Treating HIV/AIDS among Public Health Workers in Florida

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    In 2015, Florida moved from being ranked second to first nationally in total number of HIV diagnoses. To combat this statistic, public health workers were interviewed to understand perceived perspectives about available resources and practicable solutions to barriers that may inhibit the use of testing and treatment services to reduce overall health disparities and inequalities among individuals with HIV/AIDS. Ten public health workers from rural counties in Florida were interviewed, and then qualitatively analyzed using the constant comparison method. Public health workers found that multiple barriers, lack of education and knowledge of resources available among health workers, and a need for continuing education on HIV/AIDS have an impact on how preventive services and treatment are carried out. Along with highlighting key issues among public health workers, in this paper, we hope to provide feasible solutions at a time where public health funding is decreasing

    An environmental control box for serial crystallography enables multi-dimensional experiments

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    We present a new environmental enclosure for fixed-target, serial crystallography enabling full control of both the temperature and humidity. While maintaining the relative humidity to within a percent, this enclosure provides access to X-ray diffraction experiments in a wide temperature range from below 10 Ā°C to above 80 Ā°C. Coupled with the LAMA method, time-resolved serial crystallography experiments can now be carried out at truly physiological temperatures, providing fundamentally new insight into protein function. Using the hyperthermophile enzyme xylose isomerase, we demonstrate changes in the electron density as a function of increasing temperature and time. This method provides the necessary tools to successfully carry out multi-dimensional serial crystallography

    Experimental evidence for fast cluster formation of chain oxygen vacancies in YBa2Cu3O7-d being at the origin of the fishtail anomaly

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    We report on three different and complementary measurements, namely magnetisation measurements, positron annihilation spectroscopy and NMR measurements, which give evidence that the formation of oxygen vacancy clusters is on the origin of the fishtail anomaly in YBa2Cu3O7-d. While in the case of YBa2Cu3O7.0 the anomaly is intrinsically absent, it can be suppressed in the optimally doped state where vacancies are present. We therefore conclude that the single vacancies or point defects can not be responsible for this anomaly but that clusters of oxygen vacancies are on its origin.Comment: 10 pages, 4 figures, submitted to PR

    A simple vapor-diffusion method enables protein crystallization inside the HARE serial crystallography chip

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    Fixed-target serial crystallography has become an important method for the study of protein structure and dynamics at synchrotrons and X-ray free-electron lasers. However, sample homogeneity, consumption and the physical stress on samples remain major challenges for these high-throughput experiments, which depend on high-quality protein microcrystals. The batch crystallization procedures that are typically applied require time- and sample-intensive screening and optimization. Here, a simple protein crystallization method inside the features of the HARE serial crystallography chips is reported that circumvents batch crystallization and allows the direct transfer of canonical vapor-diffusion conditions to in-chip crystallization. Based on conventional hanging-drop vapor-diffusion experiments, the crystallization solution is distributed into the wells of the HARE chip and equilibrated against a reservoir with mother liquor. Using this simple method, high-quality microcrystals were generated with sufficient density for the structure determination of four different proteins. A new protein variant was crystallized using the protein concentrations encountered during canonical crystallization experiments, enabling structure determination from āˆ¼55ā€…Āµg of protein. Additionally, structure determination from intracellular crystals grown in insect cells cultured directly in the features of the HARE chips is demonstrated. In cellulo crystallization represents a comparatively unĀ­explored space in crystallization, especially for proteins that are resistant to crystallization using conventional techniques, and eliminates any need for laborious protein purification. This in-chip technique avoids harvesting the sensitive crystals or any further physical handling of the crystal-containing cells. These proof-of-principle experiments indicate the potential of this method to become a simple alternative to batch crystallization approaches and also as a convenient extension to canonical crystallization screens

    A comparison of the hypoglycemic effect of insulin with systemic venous and portal venous administration

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    The hyperglycemic effect of insulin by prolonged intraportal and systemic infusion was measured in unanesthetized dogs with a modified portacaval transposition. There was no significant difference in response with the two routes of administration. The relation of these results to research directed to surgical therapy of diabetes is discussed. Ā© 1963 W. B. Saunders Company

    Classtalk: A Classroom Communication System for Active Learning

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    This pdf file is an article describing the advantages of using Classtalk technology in the classroom to enhance classroom communication. Classtalk technology cab facilitate the presentation of questions for small group work, collec the student answers and then display histograms showing how the class answered. This new communication technology can help instructors create a more interactive, student centered classroom, especially when teaching large courses. The article describes Classtalk as a very useful tool not only for engaging students in active learning, but also for enhancing the overall communication within the classroom. This article is a selection from the electronic Journal for Computing in Higher Education. Educational levels: Graduate or professional

    Millisecond cryo-trapping by the spitrobot crystal plunger simplifies time-resolved crystallography

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    We introduce the spitrobot, a protein crystal plunger, enabling reaction quenching via cryo-trapping with millisecond time-resolution. Canonical micromesh loops are mounted on an electropneumatic piston, reactions are initiated via the liquid application method (LAMA), and finally intermediate states are cryo-trapped in liquid nitrogen. We demonstrate binding of several ligands in microcrystals of three enzymes, and trapping of reaction intermediates and conformational changes in macroscopic crystals of tryptophan synthase

    SNP microarray-based 24 chromosome aneuploidy screening demonstrates that cleavage-stage FISH poorly predicts aneuploidy in embryos that develop to morphologically normal blastocysts

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    Although selection of chromosomally normal embryos has the potential to improve outcomes for patients undergoing IVF, the clinical impact of aneuploidy screening by fluorescence in situ hybridization (FISH) has been controversial. There are many putative explanations including sampling error due to mosaicism, negative impact of biopsy, a lack of comprehensive chromosome screening, the possibility of embryo self-correction and poor predictive value of the technology itself. Direct analysis of the negative predictive value of FISH-based aneuploidy screening for an embryo's reproductive potential has not been performed. Although previous studies have found that cleavage-stage FISH is poorly predictive of aneuploidy in morphologically normal blastocysts, putative explanations have not been investigated. The present study used a single nucleotide polymorphism (SNP) microarray-based 24 chromosome aneuploidy screening technology to re-evaluate morphologically normal blastocysts that were diagnosed as aneuploid by FISH at the cleavage stage. Mosaicism and preferential segregation of aneuploidy to the trophectoderm (TE) were evaluated by characterization of multiple sections of the blastocyst. SNP microarray technology also provided the first opportunity to evaluate self-correction mechanisms involving extrusion or duplication of aneuploid chromosomes resulting in uniparental disomy (UPD). Of all blastocysts evaluated (n = 50), 58% were euploid in all sections despite an aneuploid FISH result. Aneuploid blastocysts displayed no evidence of preferential segregation of abnormalities to the TE. In addition, extrusion or duplication of aneuploid chromosomes resulting in UPD did not occur. These findings support the conclusion that cleavage-stage FISH technology is poorly predictive of aneuploidy in morphologically normal blastocysts
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