746 research outputs found

    Mapping local optical densities of states in silicon photonic structures with nanoscale electron spectroscopy

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    Relativistic electrons in a structured medium generate radiative losses such as Cherenkov and transition radiation that act as a virtual light source, coupling to the photonic densities of states. The effect is most pronounced when the imaginary part of the dielectric function is zero, a regime where in a non-retarded treatment no loss or coupling can occur. Maps of the resultant energy losses as a sub-5nm electron probe scans across finite waveguide structures reveal spatial distributions of optical modes in a spectral domain ranging from near-infrared to far ultraviolet.Comment: 18 pages, 4 figure

    The effect of three topical agents on posterior subcapsular cataract progression in royal college of surgeon (r.c.s.) rats

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    Three substances are currently reported to possess cataract retardation properties: Scenecio Maritema, N-N dimethylglycine, and Conjunctivisan A. To test their potential in retarding cataract progression, Royal College of Surgeon (R.C.S.) rats were selected as the experimental model. This strain of rats develops posterior subcapsular cataracts secondarily to an inherited retinal degeneration. At birth, the rats were divided into four groups. The ten rats in each group received twice daily topical instillation of saline, Scenecio Maritema, N-N dimethylglycine, or Conjunctivisan A for eight weeks. Analysis of serial slit lamp evaluations showed a significant delay in cataract progression in the rats receiving any of the three agents compared to : the saline control. This suggests that there might be an alternative to surgery in cataract treatment

    Book Reviews

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    Book Review 1Book Title: Zoological Catalogue of Australia Vol. 33 EchinodermataBook Authors: F.W.E Rowe & J. Gates CSIRO 1995Book Review 2Book Title: A Natural History of Inhaca Island, MozambiqueBook Author: Edited by Margaret Kalk Published by Witwatersrand University Press, 1995. 3rd Edition. 365 pagesBook Review 3Book Title: Mechanics and Physiology of Animal SwimmingBook Authors: Editors: Linda Maddock, Quentin Bone & Jeremy M.v. RaynerCambridge University Press 1994. 250 pages.Book Review 4Book Title: Chironomids: From Genes to EcosystemsBook Author: Edited by Peter CranstonCSIRO, Australia 1995. 482 pages.Book Review 5Book Title: Ecology and Morphology of CopepodsBook Authors: Edited by F.D. Ferrari and B.P. BradleyKluwer Academic Publishers, Dordrecht, The Netherlands, 1994. 530 pages. Reprinted from Hydrobiologia, Vols 292/293 (1994).Book Review 6Book Title: Restoration of Endangered Species. Conceptual Issues, Planning and ImplementationBook Authors: Edited by M.L . Bowles & C. J. WhelanCambridge University Press, 1994. 394 pages

    Salmonella and Campylobacter spp. in Northern Elephant Seals, California

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    Campylobacter and Salmonella spp. prevalence and antimicrobial drug sensitivity were determined in northern elephant seals that had not entered the water and seals that were stranded on the California coast. Stranded seals had a higher prevalence of pathogenic bacteria, possibly from terrestrial sources, which were more likely to be resistant

    Adherence to clinical follow-up recommendations for liver function tests: A cross-sectional study of patients with HCV and their associated risk behaviors

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    This study examined whether patients with Hepatitis C virus (HCV) infection adhered to their physicians\u27 recommendation and HCV clinical guidelines for obtaining a regular liver function test (LFT), and whether high-risk behaviors are associated with behavioral adherence. A cross-sectional survey was administered to 101 eligible patients with HCV who were recruited from health centers in New Jersey and Washington, DC. Adherence outcomes were defined as the patients\u27 self-report of two consecutive receipts of LFTs in accordance with their physicians\u27 recommended interval or the clinical guidelines for a LFT within 3-6 months. 67.4% of patients (66/98) reported a receipt of their physicians\u27 recommendation for a LFT. The rate of adherence to physician recommendation was about 70% (46/66), however over 50% (52/101) of patients with HCV did not obtain regular LFTs. 15.8% (16/101) of patients continued to use injection drugs. Patients who used injection drugs had 0.87 (adjusted odds ratio (aOR) = 0.13, 95% confidence interval 0.03-0.59) times lower odds adhering to their physician recommendation, relative to non-users. Patients with HIV co-infection had increased odds of adhering to the clinical guidelines (odds ratio 3.41, 95% confidence interval 1.34-8.70) vs. patients who did not report HIV co-infection. Additionally, patients who had received a physician\u27s recommendation had 7.21 times (95% confidence interval of 2.36-22.2) greater odds adhering to the clinical guidelines than those who had not. Overall, promoting HCV patient-provider communication regarding regular LFTs and reduction of risk behaviors is essential for preventing patients from HCV-related liver disease progression

    Nasal Epithelial Cells of Donor Origin after Allogeneic Hematopoietic Cell Transplantation are Generated at a Faster Rate in the First 3 Months Compared with Later Posttransplantation

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    Detection of donor-type epithelial cells (ECs) after allogeneic hematopoietic cell transplantation (allo-HCT) using XY chromosome fluorescein in situ hybridization (FISH) has suggested that hematopoietic stem cells carry a degree of developmental plasticity. This is controversial, given artifacts of XY-based detection and the possibility of hematopoietic–nonhematopoietic cell fusion. Moreover, the kinetics of donor-type ECs (quantity at different time points after transplant) is unknown. Here, we document unequivocally the existence of donor-type ECs using a method obviating the artifacts of XY-FISH and study their kinetics. Nasal scrapings and blood specimens were collected from 60 allo-HCT survivors between 7 days and 22 years posttransplantation. DNA extracted from laser-captured nasal ECs (ie, CK+CD45− cells) and blood leukocytes was polymerase chain reaction–amplified for a panel of 16 short tandem repeat markers. The median percentage of donor-type ECs (among nasal ECs) was 0% on day 7 posttransplantation, 2.8% at 3 months posttransplantation, and 8.5% at 12-22 years posttransplantation. Cell fusion was ruled out by FISH analysis for two autosomes. We conclude that donor-type nasal ECs exist after HCT, and that their percentage rises rapidly in the first 3 months posttransplantation and more slowly thereafter

    Capacity building for evidence-based decision making in local health departments: Scaling up an effective training approach

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    Abstract Background There are few studies describing how to scale up effective capacity-building approaches for public health practitioners. This study tested local-level evidence-based decision making (EBDM) capacity-building efforts in four U.S. states (Michigan, North Carolina, Ohio, and Washington) with a quasi-experimental design. Methods Partners within the four states delivered a previously established Evidence-Based Public Health (EBPH) training curriculum to local health department (LHD) staff. They worked with the research team to modify the curriculum with local data and examples while remaining attentive to course fidelity. Pre- and post-assessments of course participants (n = 82) and an external control group (n = 214) measured importance, availability (i.e., how available a skill is when needed, either within the skillset of the respondent or among others in the agency), and gaps in ten EBDM competencies. Simple and multiple linear regression models assessed the differences between pre- and post-assessment scores. Course participants also assessed the impact of the course on their work. Results Course participants reported greater increases in the availability, and decreases in the gaps, in EBDM competencies at post-test, relative to the control group. In adjusted models, significant differences (p < 0.05) were found in ‘action planning,’ ‘evaluation design,’ ‘communicating research to policymakers,’ ‘quantifying issues (using descriptive epidemiology),’ and ‘economic evaluation.’ Nearly 45% of participants indicated that EBDM increased within their agency since the training. Course benefits included becoming better leaders and making scientifically informed decisions. Conclusions This study demonstrates the potential for improving EBDM capacity among LHD practitioners using a train-the-trainer approach involving diverse partners. This approach allowed for local tailoring of strategies and extended the reach of the EBPH course.http://deepblue.lib.umich.edu/bitstream/2027.42/109528/1/13012_2014_Article_124.pd

    Combinatorial approaches for mitigating resistance to KRAS-targeted therapies.

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    Approximately 15% of all cancer patients harbor mutated KRAS. Direct inhibitors of KRAS have now been generated and are beginning to make progress through clinical trials. These include a suite of inhibitors targeting the KRASG12C mutation commonly found in lung cancer. We investigated emergent resistance to representative examples of different classes of Ras targeted therapies. They all exhibited rapid reactivation of Ras signaling within days of exposure and adaptive responses continued to change over long-term treatment schedules. Whilst the gene signatures were distinct for each inhibitor, they commonly involved upregulation of upstream nodes promoting mutant and wild type Ras activation. Experiments to reverse resistance unfortunately revealed frequent desensitization to members of a panel of anti-cancer therapeutics, suggesting that salvage approaches are unlikely to be feasible. Instead, we identified triple inhibitor combinations that resulted in more durable responses to KRAS inhibitors and that may benefit from further pre-clinical evaluation
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