2,352 research outputs found

    Analysis of the stability of InGaN/GaN multiquantum wells against ion beam intermixing

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    Ion-induced damage and intermixing was evaluated in InGaN/GaN multi-quantum wells (MQWs) using 35 keV N+ implantation at room temperature. In situ ion channeling measurements show that damage builds up with a similar trend for In and Ga atoms, with a high threshold for amorphization. The extended defects induced during the implantation, basal and prismatic stacking faults, are uniformly distributed across the quantum well structure. Despite the extremely high fluences used (up to 4 ×1016 cm-2), the InGaN MQWs exhibit a high stability against ion beam mixing

    Handgrip and knee extension strength as predictors of cancer mortality: A systematic review and metaâ analysis

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145272/1/sms13206.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145272/2/sms13206_am.pd

    SARS-CoV-2 RNA and antibody detection in breast milk from a prospective multicentre study in Spain

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    Objectives To develop and validate a specific protocol for SARS-CoV-2 detection in breast milk matrix and to determine the impact of maternal SARS-CoV-2 infection on the presence, concentration and persistence of specific SARS-CoV-2 antibodies. Design and patients This is a prospective, multicentre longitudinal study (April-December 2020) in 60 mothers with SARS-CoV-2 infection and/or who have recovered from COVID-19. A control group of 13 women before the pandemic were also included. Setting Seven health centres from different provinces in Spain. Main outcome measures Presence of SARS-CoV-2 RNA in breast milk, targeting the N1 region of the nucleocapsid gene and the envelope (E) gene; presence and levels of SARS-CoV-2-specific immunoglobulins (Igs)-IgA, IgG and IgM-in breast milk samples from patients with COVID-19. Results All breast milk samples showed negative results for presence of SARS-CoV-2 RNA. We observed high intraindividual and interindividual variability in the antibody response to the receptor-binding domain of the SARS-CoV-2 spike protein for each of the three isotypes IgA, IgM and IgG. Main Protease (MPro) domain antibodies were also detected in milk. 82.9% (58 of 70) of milk samples were positive for at least one of the three antibody isotypes, with 52.9% of these positive for all three Igs. Positivity rate for IgA was relatively stable over time (65.2%-87.5%), whereas it raised continuously for IgG (from 47.8% for the first 10 days to 87.5% from day 41 up to day 206 post-PCR confirmation). Conclusions Our study confirms the safety of breast feeding and highlights the relevance of virus-specific SARS-CoV-2 antibody transfer. This study provides crucial data to support official breastfeeding recommendations based on scientific evidence. ARS-CoV-2 antibodies but not RNA are found in breast milk from COVID-19 infected mothers

    Relaxational study of poly(vinylpyrrolidone-co-butyl acrylate) membrane by dielectric and dynamic mechanical spectroscopy

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    [EN] A poly(vinylpyrrolidone-co-butyl acrylate) (60VP-40BA) membrane is synthesized as a tractable and hydrophilic material, obtaining a water-swelling percentage around 60%. An investigation of molecular mobility by means of differential scanning calorimetry, dynamic mechanical analysis and broadband dielectric relaxation spectroscopy (DRS) is fulfilled in the dry membrane. Dielectric and viscoelastic relaxation measurements are carried out on the 60VP-40BA sample at several frequencies between -150 and 150 degrees C. The dielectric spectrum shows several relaxation processes labelled gamma, beta and alpha in increasing order of temperature, whereas in the mechanical spectrum only the beta and alpha relaxation processes are completely defined. In the dielectric measurements, conductive contributions overlap the alpha-relaxation. The apparent activation energies have similar values for the beta-relaxation in both, the mechanical and the dielectric measurements. The beta process is a Johari-Golstein secondary relaxation and it is related to the local motions of the pyrrolidone group accompanied by the motion of the segments of the polymer backbone. The gamma process is connected with the butyl unit's motions, both located in the side chains of the polymer.BRF, MC, PO and MJS are grateful to CICYT for grant MAT2012-33483. FG and JMG thank the Spanish Ministerio de Economia y Competitividad-FEDER (MAT2011-22544) and the Consejeria de Educacion-Junta de Castilla y Leon (BU001A10-2).Redondo Foj, MB.; Carsí Rosique, M.; Ortiz Serna, MP.; Sanchis Sánchez, MJ.; García, FC.; García. José Miguel (2013). Relaxational study of poly(vinylpyrrolidone-co-butyl acrylate) membrane by dielectric and dynamic mechanical spectroscopy. JOURNAL OF PHYSICS D-APPLIED PHYSICS. 46(29):295304-1-295304-12. https://doi.org/10.1088/0022-3727/46/29/295304S295304-1295304-12462

    Gender differences in the utilization of health-care services among the older adult population of Spain

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    BACKGROUND: Compared to men, women report greater morbidity and make greater use of health-care services. This study examines potential determinants of gender differences in the utilization of health-care services among the elderly. METHODS: Cross-sectional study covering 3030 subjects, representative of the non-institutionalized Spanish population aged 60 years and over. Potential determinants of gender differences in the utilization of health services were classified into predisposing factors (age and head-of-family status), need factors (lifestyles, chronic diseases, functional status, cognitive deficit and health-related quality of life (HRQL)) and enabling factors (educational level, marital status, head-of-family employment status and social network). Relative differences in the use of each service between women and men were summarized using odds ratios (OR), obtained from logistic regression. The contribution of the variables of interest to the gender differences in the use of such services was evaluated by comparing the OR before and after adjustment for such variables. RESULTS: As compared to men, a higher percentage of women visited a medical practitioner (OR: 1.24; 95% confidence limits (CL): 1.07–1.44), received home medical visits (OR: 1.67; 95% CL: 1.34–2.10) and took ≥3 medications (OR: 1.54; 95% CL: 1.34–1.79), but there were no gender differences in hospital admission or influenza vaccination. Adjustment for need or enabling factors led to a reduction in the OR of women compared to men for utilization of a number of services studied. On adjusting for the number of chronic diseases, the OR (95% CL) of women versus men for ingestion of ≥3 medications was 1.24 (1.06–1.45). After adjustment for HRQL, the OR was 1.03 (0.89–1.21) for visits to medical practitioners, 1.24 (0.98–1.58) for home medical visits, 0.71 (0.58–0.87) for hospitalization, and 1.14 (0.97–1.33) for intake of ≥3 medications. After adjustment for the number of chronic diseases and HRQL, the OR of hospitalization among women versus men was 0.68 (0.56–0.84). CONCLUSION: The factors that best explain the greater utilization of health-care services by elderly women versus men are the number of chronic diseases and HRQL. For equal need, certain inequality was observed in hospital admission, in that it proved less frequent among women

    Measurement of the Depth of Maximum of Extensive Air Showers above 10^18 eV

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    We describe the measurement of the depth of maximum, Xmax, of the longitudinal development of air showers induced by cosmic rays. Almost four thousand events above 10^18 eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106 +35/-21) g/cm^2/decade below 10^(18.24 +/- 0.05) eV and (24 +/- 3) g/cm^2/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm^2. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.Comment: Accepted for publication by PR

    Operations of and Future Plans for the Pierre Auger Observatory

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    Technical reports on operations and features of the Pierre Auger Observatory, including ongoing and planned enhancements and the status of the future northern hemisphere portion of the Observatory. Contributions to the 31st International Cosmic Ray Conference, Lodz, Poland, July 2009.Comment: Contributions to the 31st ICRC, Lodz, Poland, July 200
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