Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
2.
Nature ; 609(7928): 685-688, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36131036

RESUMO

Fast radio bursts (FRBs) are highly dispersed, millisecond-duration radio bursts1-3. Recent observations of a Galactic FRB4-8 suggest that at least some FRBs originate from magnetars, but the origin of cosmological FRBs is still not settled. Here we report the detection of 1,863 bursts in 82 h over 54 days from the repeating source FRB 20201124A (ref. 9). These observations show irregular short-time variation of the Faraday rotation measure (RM), which scrutinizes the density-weighted line-of-sight magnetic field strength, of individual bursts during the first 36 days, followed by a constant RM. We detected circular polarization in more than half of the burst sample, including one burst reaching a high fractional circular polarization of 75%. Oscillations in fractional linear and circular polarizations, as well as polarization angle as a function of wavelength, were detected. All of these features provide evidence for a complicated, dynamically evolving, magnetized immediate environment within about an astronomical unit (AU; Earth-Sun distance) of the source. Our optical observations of its Milky-Way-sized, metal-rich host galaxy10-12 show a barred spiral, with the FRB source residing in a low-stellar-density interarm region at an intermediate galactocentric distance. This environment is inconsistent with a young magnetar engine formed during an extreme explosion of a massive star that resulted in a long gamma-ray burst or superluminous supernova.

3.
Public Health ; 199: 17-19, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34517289

RESUMO

OBJECTIVES: This study aimed to determine SARS-CoV-2 seroprevalence among pregnant women in the Scottish population during the second wave of the COVID-19 pandemic. STUDY DESIGN: Prospective national serosurvey. METHODS: We tested 13,428 residual samples retrieved from pregnant women participating in the first trimester combined ultrasound and biochemical screening for fetal trisomy across Scotland for SARS-CoV-2 antibodies over a 6-month period from November 2020 to April 2021. Seroprevalence estimates were adjusted for the sensitivity and specificity of the assays and weighted to reference populations. RESULTS: Seroprevalence rates in the antenatal samples significantly increased from 5.5% (95% confidence interval [CI] 4.7%-6.5%) in the 5-week period up to and including International Organization for Standardization (ISO) Week 51 (w/b Monday 14 December 2020) to 11.3% (95% CI 10.1%-12.6%) in the 5-week period up to and including ISO Week 14 (w/b Monday 5 April 2021). Increasing seroprevalence trends across the second wave were observed among all age groups. CONCLUSIONS: By the end of the second wave of the COVID-19 pandemic, approximately one in 10 women tested around the end of the first trimester of pregnancy had antibodies to SARS-CoV-2, suggesting that the vast majority were still susceptible to COVID-19 as they progressed to the later stages of pregnancy, when risks from infection are elevated for both mother and baby.


Assuntos
COVID-19 , SARS-CoV-2 , Anticorpos Antivirais , Feminino , Humanos , Imunoglobulina G , Pandemias , Gravidez , Gestantes , Prevalência , Estudos Prospectivos , Escócia/epidemiologia , Estudos Soroepidemiológicos
4.
J Nutr Sci ; 6: e39, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29152243

RESUMO

Pomegranate (Punica granatum), a polyphenol-rich fruit, has been suggested to reduce cardiovascular risk due to its antioxidant properties. Hypertension and obesity are the most preventable cardiovascular risk factors. Few studies on blood pressure and/or body-weight status have been conducted in human subjects. Previous investigations have tended to focus on pomegranate juice. The aim of the present study was to investigate the effect of pomegranate extract (PE) on blood pressure and anthropometric measures in adults with no symptomatic disease. A total of fifty-five participants enrolled in a randomised double-blinded placebo-controlled clinical trial where they were assigned to either PE capsules or placebo capsules for 8 weeks. Blood pressure, body weight, waist circumference, waist:hip ratio (WHR) and body composition (lean body mass, body fat) were measured at baseline, week 4 and week 8. Results showed a significant decrease in diastolic blood pressure after 8 weeks (by 2·79 (sd 5·32) mmHg; P < 0·05), while the decrease in systolic blood pressure did not reach statistical significance (2·57 (sd 7·4) mmHg; P > 0·05). Body fat percentage, lean body mass, waist circumference and WHR did not significantly differ between groups at the end of the intervention. Results suggest that PE may reduce blood pressure and possibly prevent hypertension in the normotensive population. Further large trials are required to elucidate this effect.

5.
Comput Nurs ; 13(3): 109-13, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7796367

RESUMO

The purpose of this study was to examine the factor structure and reliability of the Stronge-Brodt Nurses' Attitudes Toward Computers Questionnaire. The instrument was administered to nurses before (T1, n = 391) and after (T2, n = 265) the implementation of a computerized patient care information system. A factor analysis of each sample was carried out using the SPSS/PC+ factor procedure with varimax rotation and Kaiser normalization. The factor analyses for T1 and T2 were consistent and identified three factors that parallel those generated in a factor analysis performed by Schwirian et al (1989). In both samples of the current study, the internal consistency reliability for the first factor was high (T1 alpha = .91, T2 alpha = .92), whereas the second and third factors demonstrated diminished reliability. Overall instrument reliability was .93 at T1 and .92 at T2. This study, with relatively large sample sizes, provided further clarification of the factor structure and supported the high reliability of the instrument.


Assuntos
Atitude Frente aos Computadores , Enfermeiras e Enfermeiros/psicologia , Psicometria , California , Análise Fatorial , Humanos , Reprodutibilidade dos Testes , Inquéritos e Questionários
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA