1,009 research outputs found
H2-Induced Pressure Broadening and Pressure Shift in the P-Branch of the v3 Band of CH4 from 300 to 700 K
For accurate modelling of observations of exoplanet atmospheres,
quantification of the pressure broadening of infrared absorption lines for and
by a variety of gases at elevated temperatures is needed. High-resolution
high-temperature H2-pressure-broadened spectra are recorded for the CH4 v3-band
P-branch. Measured linewidths for 116 transitions between 2840 and 3000 cm^{-1}
with temperature and pressures ranging between 300 and 700 K, and 10 and 933
Torr, respectively, were used to find rotation- and
tetrahedral-symmetry-dependent coefficients for pressure and temperature
broadening and pressure-induced lineshifts. The new pressure-broadening data
will be useful in radiative-transfer models for retrieving the properties of
observed expolanet atmospheres.Comment: 23 pages, 10 figures, 7 tables, Resubmitted for 2nd round of
revisions to JQSRT (Journal of Quantitative Spectroscopy & Radiative
Transfer). Comments welcome
Structure and function relationship of human heart from DENSE MRI
The study here, suggests a macroscopic structure for the Left Ventricle (LV), based on the heart kinematics which is
obtained through imaging. The measurement of the heart muscle deformation using the Displacement ENcoding with
Stimulated Echoes (DENSE) MRI, which describes the heart kinematics in the Lagrangian frame work, is used to
determine the high resolution patterns of true myocardial strain. Subsequently, the tangential Shortening Index (SI) and
the thickening of the LV wall are calculated for each data point. Considering the heart as a positive-displacement pump,
the contribution of each segment of LV in the heart function, can be determined by the SI and thickening of the wall in
the same portion. Hence the SI isosurfaces show the extent and spatial distribution of the heart activity and reveals its
macro structure. The structure and function of the heart are, therefore, related which in turn results in a macroscopic
model for the LV. In particular, it was observed that the heart functionality is not uniformly distributed in the LV, and
the regions with greater effect on the pumping process, form a band which wraps around the heart. These results, which
are supported by the established histological evidence, may be considered as a landmark in connecting the structure and
function of the heart through imaging. Furthermore, the compatibility of this model with microscopic observations
about the fiber direction is investigated [1]. This method may be used for planning as well as post evaluation of the
ventriculoplasty
Fahr’s syndrome with seizure presentation
Fahr's disease (FD) or Fahr’s syndrome is characterized by basal ganglia calcification with clinical manifestations
in the form of neuropsychiatric disorders, neurological symptoms, and cognitive symptoms. FD commonly affects
young to middle aged adults. The etiology of this syndrome does not identify a specific agent. Clinical
manifestations of this disease incorporate a wide variety of symptoms. The diagnostic criteria of Fahr’s Syndrome
consist of bilateral calcification of basal ganglia, progressive neurologic dysfunction, absence of biochemical
abnormalities, infectious, traumatic, and a significant family history. Medical imaging techniques for the diagnosis
consist of computed tomography (CT), magnetic resonance imaging (MRI), and plain radiography of the skull. This
paper presents a case of Fahr’s syndrome in a 60-year-old married prisoner with antisocial personality and
seizures. Furthermore, CT and MRI scans showed bilateral symmetric calcifications in the basal ganglia
calcification (BGC) and dentate nuclei, cerebellum, and centrum semiovale
Fluctuations and transport in a stirred fluid with a mean gradient
The effective thermal diffusivity D* and the probability distribution of temperature fluctuations are measured in a stirred fluid across which a temperature gradient is maintained. A distinct mixing transition is observed for D* as a function of Reynolds number R. Above the transitions, the distribution is strongly non-Gaussian and approaches an exponential exp(-‖δT‖/βξ), where β is the local temperature gradient and ξ the correlation length
Effects of softwood biochar on the status of nitrogen species and elements of potential toxicity in soils
The effects of softwood-derived biochar materials on the chemical behaviour of environmental contaminants in
soils were examined in two microcosm scenarios. Addition of the biochar materials into an alkaline sandy soil
significantly reduced NH3 volatilization and made it available for conversion into NO3- via nitrification. This
process could be enhanced by an increased application rate of biochar produced at a higher pyrolysis temperature.
Under the alkaline conditions encountered in the experiment, the biochar surfaces tended to be negatively
charged which disfavours the adsorption of NO3-. Therefore, in a fully open system, the addition of
biochar materials was likely to contribute to nitrate leaching from the fertilized alkaline sandy soil. The effects of
the biochar materials on the immobilization of Fe2+ generated via anaerobic iron reduction in the inundated
contaminated soil were not observed, except for the treatment with a higher dose of biochar material produced
under pyrolysis temperature at 700°C after the 240th h of incubation. Arsenic showed similar behaviour to Fe.
Zn tended to have a higher affinity to the biochar, as compared to Mn. Immobilization of Pb occurred regardless
of whether or not the biochar is present
Structure and function relationship of Zebrafish embryonic heart from confocal microscopy images
Confocal microscopy enables us to track myocytes in the embryonic zebrafish heart. The Zeiss LSM 5 Live high speed
confocal microscope has been used to take optical sections (at 3 µm intervals and 151 frames per second) through a
fluorescently labeled zebrafish heart at two developmental stages (26 and 34 hours post fertilization (hpf)). This data
provides unique information allowing us to conjecture on the morphology and biomechanics of the developing vertebrate
heart. Nevertheless, the myocytes, whose positions could be determined in a reliable manner, were located sparsely and
mostly in one side of the heart tube. This difficulty was overcome using computational methods, that give longitudinal,
radial and circumferential displacements of the myocytes as well as their contractile behavior. Applied strain analysis
has shown that in the early embryonic heart tube, only the caudal region (near the in-flow) and another point in the
middle of the tube can be active; the rest appears to be mostly passive. This statement is based on the delay between
major strain and displacement which a material point experiences. Wave-like propagation of all three components of the
displacement, especially in the circumferential direction, as well as the almost-periodic changes of the maximum strain
support the hypothesis of helical muscle structure embedded in the tube. Changes of geometry in the embryonic heart
after several hours are used to verify speculations about the structure based on the earlier images and aforementioned
methods
Long-term dry immersion: review and prospects
Dry immersion, which is a ground-based model of prolonged conditions of microgravity, is widely used in Russia but is less well known elsewhere. Dry immersion involves immersing the subject in thermoneutral water covered with an elastic waterproof fabric. As a result, the immersed subject, who is freely suspended in the water mass, remains dry. For a relatively short duration, the model can faithfully reproduce most physiological effects of actual microgravity, including centralization of body fluids, support unloading, and hypokinesia. Unlike bed rest, dry immersion provides a unique opportunity to study the physiological effects of the lack of a supporting structure for the body (a phenomenon we call \u27supportlessness\u27). In this review, we attempt to provide a detailed description of dry immersion. The main sections of the paper discuss the changes induced by long-term dry immersion in the neuromuscular and sensorimotor systems, fluid-electrolyte regulation, the cardiovascular system, metabolism, blood and immunity, respiration, and thermoregulation. The long-term effects of dry immersion are compared with those of bed rest and actual space flight. The actual and potential uses of dry immersion are discussed in the context of fundamental studies and applications for medical support during space flight and terrestrial health care
Malignancy risk analysis in patients with inadequate fine needle aspiration cytology (FNAC) of the thyroid
Background
Thyroid fine needle aspiration cytology (FNAC) is the standard diagnostic modality for thyroid nodules. However, it has limitations among which is the incidence of non-diagnostic results (Thy1). Management of cases with repeatedly non-diagnostic FNAC ranges from simple observation to surgical intervention. We aim to evaluate the incidence of malignancy in non-diagnostic FNAC, and the success rate of repeated FNAC. We also aim to evaluate risk factors for malignancy in patients with non-diagnostic FNAC.
Materials and Methods
Retrospective analyses of consecutive cases with thyroid non diagnostic FNAC results were included.
Results
Out of total 1657 thyroid FNAC done during the study period, there were 264 (15.9%) non-diagnostic FNAC on the first attempt. On repeating those, the rate of a non-diagnostic result on second FNAC was 61.8% and on third FNAC was 47.2%. The overall malignancy rate in Thy1 FNAC was 4.5% (42% papillary, 42% follicular and 8% anaplastic), and the yield of malignancy decreased considerably with successive non-diagnostic FNAC. Ultrasound guidance by an experienced head neck radiologist produced the lowest non-diagnostic rate (38%) on repetition compared to US guidance by a generalist radiologist (65%) and by non US guidance (90%).
Conclusions
There is a low risk of malignancy in patients with a non-diagnostic FNAC result, commensurate to the risk of any nodule. The yield of malignancy decreased considerably with successive non-diagnostic FNAC
A (re) organização espacial da Comunidade Tradicional de Antônio Maria Coelho, Corumbá/MS.
O estudo tem como propósito a compreensão da (re) organização da comunidade tradicional de Antônio Maria Coelho (AMC), bem como do potencial de ampliação do extrativismo agroecológico da bocaíuva. Utilizou-se a metodologia de diagnóstico rural participativo com técnicas de observação participante e entrevistas semi-estruturadas. A comunidade possui características rurais, com as moradias parcialmente dispersas em grupos. Observam-se constantes mudanças na dinâmica socioespacial da comunidade de AMC. Estas mudanças estão relacionadas com a pressão econômica proporcionada pela instalação de empresas mineradoras na região, provocando alteração no espaço e a busca de novas formas de organização social. The study has as purpose a understanding the (re) organization of traditional community by Antônio Maria Coelho (AMC) with a view to subsidize the potential of enlargement from extrativism agroecologic the bocaiúva. Being used the methodology to diagnosis participatory rural with observation techniques participant and semi-structured interviews The community has rural characteristics, with the housing partially dispersed in groups. Constant changes are observed in the dynamics of socio-community AMC. These changes are related to the economic pressure provided by the installation of mining companies in the region, causing changes in space and the search for new forms of social organization.Título em inglês: The spatial (re) organization of Traditional Community by Antônio Maria Coelho, Corumbá / MS
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