858 research outputs found

    Electrostatic Discharge Properties of Fused Silica Coatings

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    The electric field value at which electrostatic discharge (ESD) occurs was studied for thin coatings of fused silica (highly disordered SiO2/SiOx) on conductive substrates, such as those encountered as optical coatings and in Si microfabrication. The electrostatic breakdown field was determined using an increasing voltage, while monitoring the leakage current. A simple parallel-plate capacitor geometry was used, under medium vacuum and at temperatures down to ~150 K using a liquid N2 reservoir. The breakdown field, pre-breakdown arcing and I-V curves for fused silica samples are compared for ~60 nm and ~80 μm thick, room and low temperature, and untreated and irradiated samples. Unlike typical I-V results for polymeric insulators, the thin film silica samples did not exhibit pre-breakdown arcing, displayed transitional resistivity after initial breakdown, and in many cases showed evidence of a second discontinuity in the I-V curves. This diversity of observed discharge phenomena is discussed in terms of breakdown modes and defect generation on a microscopic scale

    Project Evidence: Responding to the Changing Professional Learning Needs of Mentors in Initial Teacher Education

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    This positioning paper seeks to contribute to the knowledge base of the changing professional learning needs of supervising or mentor teachers in initial teacher education. To do so, we draw from the work of Project Evidence, an Australian Office of Learning and Teaching funded project, designed to support teacher education through the development of a professional learning website. Our focus in this paper is our growing understanding of the complex work of teachers as they navigate new supervisory and mentoring roles in the current education context of high stakes standardisation. We examine the implications for their changing work practices within the policy imperative to build effective school-university partnerships in teacher education. Within this context, we discuss the ways in which Project Evidence has attempted to (re)position the emphasis of the work of the mentor teacher away from the dual role of assessor and supervisor to encompass their own professional learning

    Physician-prescribed Asthma Treatment Regimen does not differ Between Smoking and Non-smoking Patients With Asthma in Seoul and Gyunggi province of Korea

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. ACKNOWLEDGMENTS The authors thank Lauren Weisenfluh and Melissa Stauffer, PhD, in collaboration with SCRIBCO, for medical writing assistance. Funding for this research was provided by Merck & Co., Inc. The authors also wish to thank Eric Maiese and Sharlette Everett for their contributions to the design and implementation of the study and the analytic plan. The authors would also like to thank the study investigators who contributed to patient enrollment and data collection: Drs. Young Il Hwang (Hallym University Sacred Heart Hospital), Young Min Ye (Ajou University Medical Center), Joo Hee Kim (Ajou University Medical Center), Heung Woo Park (Seoul National University Hospital), Tae Wan Kim (Seoul National University Hospital), Jae Jeong Shim (Korea University Guro Hospital), Gyu Young Hur (Korea University Guro Hospital), Soo Taek Uh (SoonChunHyang University Hospital), Sang Ha Kim (Wonju Christian Hospital), Myoung Kyu Lee (Wonju Christian Hospital), Soo Keol Lee (Dong-A Medical Center), Jin Hong Chung (Yeungnam University Medical Center), Kyu Jin Kim (Yeungnam University Medical Center), Young Koo Jee (Dankook University Hospital), Kyung Mook Kim (Dankook University Hospital), Young Il Koh (Chonnam National University Hospital), Cheol Woo Kim (Inha university Hospital), You Sook Cho (Seoul Asan Medical Center), Tae Bum Kim (Seoul Asan Medical Center), Jae Myung Lee (Myeong Internal Medicine), Young Mok Lee (Good Friends Internal Medicine), Bong Chun Lee (Namsan Hospital), So Yoen Park (A&A Clinic).Peer reviewedPublisher PD

    The stroke oxygen pilot study: a randomized control trial of the effects of routine oxygen supplementation early after acute stroke--effect on key outcomes at six months

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    Introduction: Post-stroke hypoxia is common, and may adversely affect outcome. We have recently shown that oxygen supplementation may improve early neurological recovery. Here, we report the six-month outcomes of this pilot study. Methods: Patients with a clinical diagnosis of acute stroke were randomized within 24 h of admission to oxygen supplementation at 2 or 3 L/min for 72 h or to control treatment (room air). Outcomes (see below) were assessed by postal questionnaire at 6 months. Analysis was by intention-to-treat, and statistical significance was set at p#0.05. Results: Out of 301 patients randomized two refused/withdrew consent and 289 (148 in the oxygen and 141 in the control group) were included in the analysis: males 44%, 51%; mean (SD) age 73 (12), 71 (12); median (IQR) National Institutes of Health Stroke Scale score 6 (3, 10), 5 (3, 10) for the two groups respectively. At six months 22 (15%) patients in the oxygen group and 20 (14%) in the control group had died; mean survival in both groups was 162 days (p= 0.99). Median (IQR) scores for the primary outcome, the modified Rankin Scale, were 3 (1, 5) and 3 (1, 4) for the oxygen and control groups respectively. The covariate-adjusted odds ratio was 1.04 (95% CI 0.67, 1.60), indicating that the odds of a lower (i.e. better) score were non-significantly higher in the oxygen group (p= 0.86). The mean differences in the ability to perform basic (Barthel Index) and extended activities of daily living (NEADL), and quality of life (EuroQol) were also non-significant. Conclusions: None of the key outcomes differed at 6 months between the groups. Although not statistically significant and generally of small magnitude, the effects were predominantly in favour of the oxygen group; a larger trial, powered to show differences in longer-term functional outcomes, is now on-going. Trial Registration: Controlled-Trials.com ISRCTN12362720; Eudract.ema.europa.eu 2004-001866-4

    Low serum transferrin levels in HFE C282Y homozygous subjects are associated with low CD8(+) T lymphocyte numbers.

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    Blood Cells Mol Dis. 2005 Nov-Dec;35(3):319-25. Epub 2005 Sep 1. Low serum transferrin levels in HFE C282Y homozygous subjects are associated with low CD8(+) T lymphocyte numbers. Macedo MF, Cruz E, Lacerda R, Porto G, de Sousa M. SourceDivision of Human Genetics and Genetic Disorders, Iron Genes and the Immune System Laboratory, Institute for Molecular and Cell Biology (IBMC), Oporto, Portugal. Abstract Hereditary hemochromatosis (HH) is a genetic iron overload disease, in the majority of cases associated with homozygosity for the C282Y mutation of the HFE gene. In spite of this genetic homogeneity, there is a great clinical heterogeneity among HH patients. Low CD8(+) lymphocyte numbers have been associated with a more severe expression of iron overload in HH patients, and in experimental models of iron overload. HH patients present low serum transferrin levels. Transferrin is an indispensable resource for lymphopoiesis. Lymphocyte homeostasis follows general ecology rules of population dynamics that involve competition for limiting resources. In the present study, we questioned whether transferrin levels could be associated with the anomalies seen previously in lymphocyte subset numbers in HH patients. Transferrin levels, total and subset T lymphocyte counts were done in 426 apparently healthy subjects genotyped for HFE. All HFE C282Y carriers presented significantly lower serum transferrin levels than the wild type group, a difference that could not be explained solely by the degree of iron overload. Significant differences were also seen in transferrin levels between males and females, with females presenting higher average serum Transferrin levels. In the population of subjects with Transferrin levels lower than 248 mg/dl, a positive correlation was seen between the peripheral CD8(+) lymphocyte numbers and serum transferrin levels (R(2) = 2.41; r = 0.16; P = 0.018). To test the possible limiting resource effect of transferrin, the correlation between transferrin levels and CD8(+) lymphocyte numbers was scrutinized in 34 HH patients, homozygous for the C282Y mutation. In the homozygous males, where the lowest average transferrin levels were seen, another highly significant correlation was observed between Transferrin levels and CD8(+) numbers. This correlation points to a possible role of transferrin as a limiting resource for MHC class I dependent lymphocyte proliferation, an effect that was not observed in C282Y homozygous female patients. PMID: 16140024 [PubMed - indexed for MEDLINE

    The nature of the compact HII region Sh 2-89 and its stellar content

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    We present an analysis of the structure and properties of the compact HII region Sh 2-89, and certain of the young stellar objects (YSOs) within this regime, using mid-infrared (MIR) mapping derived from the Spitzer Space Telescope (SST) and visual slit spectroscopy of the inner regions of the source. We show that the region has a bipolar structure, and contains a variety of Class I and II YSOs. Much of the MIR emission appears to be dominated by PAH emission bands, which cause strong increases in flux in the 5.8 and 8.0 microns photometric channels, whilst the variation of H_alpha, [NII] at 6583 A, [SII] at 6716+6731 A, and MIR emission profiles confirms the presence of complex ionisation fronts, and ionisation stratification.Comment: 12 pages, 6 figures, Accepted for publication in MNRAS. 33 pages in arXi
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