2,881 research outputs found
Analysis of total urinary catecholamines by liquid chromatography: methodology, routine experience and clinical interpretations of results
A simple routine method is described for simultaneous assay of total urinary adrenaline, noradrenaline and dopamine. The catecholamines are pre-purified on a small ion-exchange column, separated by reversed phase ion-pair liquid chromatography, and are quantitated by electrochemical detection. The method was routinely applied to 422 urines. Elevated values were found in four urine specimens obtained from patients with histologically proven phaeochromocytomas. Virtually no interference by endogenous or exogenous compounds was found. Values for urinary catecholamines determined by fluorimetric analysis agreed with those obtained by high pressure liquid chromatography with electrochemical detection. Within-day CVs for the compounds ranged from 5.2-11.9%, between-day CVs from 3.3-6.6%. The normal range (95% confidence level) was 20-230 micrograms/24 h for noradrenaline and 1-35 micrograms/24 h for adrenaline
Morphology and biomechanics of the nests of the Common Blackbird Turdus merula
Capsule Common blackbirds select different materials, with varying biomechanical properties, to construct different parts of their nest.
Aims This study tested the hypothesis that outer components of a nest have a more structural role and so are stronger than materials used to line the cup.
Methods Blackbird nests were measured prior to being dismantled to isolate structural components which were tested for mechanical strength and rigidity.
Results Outer nest wall materials were significantly thicker, stronger and more rigid than materials in the inner structural wall or the cup lining. In the vertical plane materials used in the structural wall did not differ. By contrast, lining materials from the bottom of the nest cup were significantly thicker, stronger and more rigid than materials from the top of the cup.
Conclusion Blackbirds use different materials in nest construction roles suited to their properties and so may be able to recognise the structural properties of these materials. Materials on the outside of the nest may have a key structural role during construction
Long photometric cycle and disk evolution in the Lyrae type binary OGLE-BLG-ECL-157529
The subtype of hot algol semidetached binaries dubbed Double Periodic
Variables (DPVs) are characterized by a photometric cycle longer than the
orbital one, whose nature has been related to a magnetic dynamo in the donor
component controlling the mass transfer rate. We aim to understand the
morphologic changes observed in the light curve of OGLE-BLG-ECL-157529 that are
linked to the long cycle. In particular, we want to explain the changes in
relative depth of primary and secondary eclipses. We analyze and -band
OGLE photometric times series spanning 18.5 years and model the orbital light
curve. We find that OGLE-BLG-ECL-157529 is a new eclipsing Galactic DPV of
orbital period 24\fd8, and that its long cycle length decreases in amplitude
and length during the time baseline. We show that the changes of the orbital
light curve can be reproduced considering an accretion disk of variable
thickness and radius, surrounding the hottest stellar component. Our models
indicate changes in the temperatures of hot spot and bright spot during the
long cycle, and also in the position of the bright spot. This, along with the
changes in disk radius might indicate a variable mass transfer in this system.Comment: 8 pages, 14 figures, 2 tables, accepted for publication in Astronomy
and Astrophysic
Control of defect-mediated tunneling barrier heights in ultrathin MgO films
The impact of oxygen vacancies on local tunneling properties across
rf-sputtered MgO thin films was investigated by optical absorption spectroscopy
and conducting atomic force microscopy. Adding O to the Ar plasma during
MgO growth alters the oxygen defect populations, leading to improved local
tunneling characteristics such as a lower density of current hotspots and a
lower tunnel current amplitude. We discuss a defect-based potential landscape
across ultrathin MgO barriers.Comment: 4 pages, 4 figure
Detection of CN gas in Interstellar Object 2I/Borisov
The detection of Interstellar Objects passing through the Solar System offers
the promise of constraining the physical and chemical processes involved in
planetary formation in other extrasolar systems. While the effect of outgassing
by 1I/2017 U1 ('Oumuamua) was dynamically observed, no direct detection of the
ejected material was made. The discovery of the active interstellar comet
2I/Borisov means spectroscopic investigations of the sublimated ices is
possible for this object. We report the first detection of gas emitted by an
interstellar comet via the near-UV emission of CN from 2I/Borisov at a
heliocentric distance of = 2.7 au on 2019 September 20. The production rate
was found to be Q(CN) = s, using a simple
Haser model with an outflow velocity of 0.5 km s. No other emission was
detected, with an upper limit to the production rate of C of
s. The spectral reflectance slope of the dust coma over
\AA\ \AA \ is steeper than at longer wavelengths, as
found for other comets. Broad band photometry on 2019 September 19 gave a
dust production rate of cm. Modelling of the observed gas and
dust production rates constrains the nuclear radius to km assuming
reasonable nuclear properties. Overall, we find the gas, dust and nuclear
properties for the first active Interstellar Object are similar to normal Solar
System comets.Comment: 9 pages, 4 figures, accepted for publication in ApJ
Repercussões da COVID-19 no cuidado ao idoso: percepções de enfermeiros da Atenção Primária à Saúde
Objective: to understand the perceptions of Primary Health Care (PHC) nurses about the repercussions of COVID-19 on the care and daily life of the elderly. Method: exploratory, descriptive study with a qualitative approach. Ten nurses from the PHC of Santa Catarina were integrated. Data collection took place through a semi-structured interview, between July and September 2021, with an application video call due to the pandemic. Content analysis was used to organize and assess the information. Results: two categories emerged: Repercussions of COVID-19 in the care of the elderly in PHC; COVID-19 and the transformations in the daily lives of the elderly regarding health care. Conclusion: the pandemic generated social and affective restrictions and reduced face-to-face activities carried out in PHC, culminating in changes in health. Therefore, the reflection and planning of actions regarding the care of the elderly in PHC are fundamental, especially regarding mental health, affected in the pandemic context.Objetivo: comprender las percepciones de los enfermeros de la Atención Primaria de Salud (APS) sobre las repercusiones de la COVID-19 en el cuidado y el cotidiano de los ancianos. Método: estudio exploratorio, descriptivo con abordaje cualitativo. Se integraron 10 enfermeros de la APS de Santa Catarina. La recolección de datos se realizó a través de una entrevista semi-estructurada, entre julio y septiembre de 2021, con una aplicación de video llamada debido a la pandemia. Para la organización y evaluación de la información se utilizó el análisis de contenido. Resultados: surgieron dos categorías: Repercusiones de la COVID-19 en el cuidado del anciano en la APS; COVID-19 y las transformaciones en el cotidiano de los ancianos para el cuidado de la salud. Conclusión: la pandemia generó restricciones sociales y afectivas, además de la reducción de las actividades presenciales realizadas en la APS, culminando en cambios en la salud. Por lo tanto, son fundamentales la reflexión y la planificación de acciones para el cuidado de los ancianos en la APS, especialmente en lo que respecta a la salud mental, afectada en la situación de pandemia.Objetivo: compreender as percepções de enfermeiros da Atenção Primária à Saúde (APS) sobre as repercussões da COVID-19 no cuidado e cotidiano do idoso. Método: estudo exploratório, descritivo, com abordagem qualitativa. Integraram-se 10 enfermeiras da APS de Santa Catarina. A coleta de dados ocorreu por meio de entrevista semiestruturada, entre julho e setembro de 2021, com chamada de vídeo em aplicativo devido à pandemia. Para a organização e avaliação das informações, utilizou-se a análise de conteúdo. Resultados: emergiram duas categorias: Repercussões da COVID-19 no cuidado ao idoso na APS; COVID-19 e as transformações no cotidiano dos idosos para o cuidado em saúde. Conclusão: a pandemia gerou restrições sociais e afetivas, além de reduzir atividades presenciais realizadas na APS, culminando em alterações na saúde. Portanto, a reflexão e o planejamento de ações perante o cuidado ao idoso na APS são fundamentais, principalmente quanto à saúde mental, afetada na conjuntura pandêmica
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