412 research outputs found
Heliophysics Event Knowledgebase for the Solar Dynamics Observatory and Beyond
The immense volume of data generated by the suite of instruments on SDO
requires new tools for efficient identifying and accessing data that is most
relevant to research investigations. We have developed the Heliophysics Events
Knowledgebase (HEK) to fill this need. The HEK system combines automated data
mining using feature-detection methods and high-performance visualization
systems for data markup. In addition, web services and clients are provided for
searching the resulting metadata, reviewing results, and efficiently accessing
the data. We review these components and present examples of their use with SDO
data.Comment: 17 pages, 4 figure
Indeterminate results of QuantiFERON TB-2G test performed in routine clinical practice
Is there something of the MCT in orientationally disordered crystals ?
Molecular Dynamics simulations have been performed on the orientationally
disordered crystal chloroadamantane: a model system where dynamics are almost
completely controlled by rotations. A critical temperature T_c = 225 K as
predicted by the Mode Coupling Theory can be clearly determined both in the
alpha and beta dynamical regimes. This investigation also shows the existence
of a second remarkable dynamical crossover at the temperature T_x > T_c
consistent with a previous NMR and MD study [1]. This allows us to confirm
clearly the existence of a 'landscape-influenced' regime occurring in the
temperature range [T_c-T_x] as recently proposed [2,3].Comment: 4 pages, 5 figures, REVTEX
Topology Optimization and Characterization of Ti6Al4V ELI Cellular Lattice Structures by Laser Powder Bed Fusion for Biomedical Applications
Published ArticleTopology optimization approach was used for the design of Ti6Al4V ELI lattice structures with stiffness and
density close to the human bone for implant applications. Three lattice designs with volume densities of 35 %, 40
% and 45 % and corresponding elastic modulus of 18.6 GPa, 23.1 GPa 27.4 GPa close to the human bone were
generated. Laser powder bed fusion (LPBF) technique was used for the manufacturing of the specimens. Physical
measurements and mechanical characterization of specimens were assessed by microCT analyses and compression
test, perpendicular and parallel to the building direction of the specimens.
LPBF Ti6Al4V ELI manufactured lattice structures showed deviations in wall thickness in comparison with the
generated designs, leading to an increase in relative porosity but also a decrease in elastic modulus in comparison
with the original designs. Horizontal walls of the lattice structures showed higher wall thickness in
comparison with the vertical walls, leading to anisotropic behaviour of the lattice structures. Higher elastic
modulus and compression strength were obtained when thicker walls were oriented along the loading direction
of the compression test, showing a complete failure by dividing the specimens into two neighbouring halves. All
specimens showed 45° diagonal shear fracture along the structure. On the other hand, higher energy absorption
at first maximum compression strength peak was observed when samples were tested parallel to the building
direction (when thinner walls were oriented along the loading compression direction). Results showed that
designed lattice structures can possess the levels of human bones’ stiffness and therefore can reduce/avoid stress
shielding on implant applications
Evidence for energy injection and a fine-tuned central engine at optical wavelengths in GRB 070419A
We present a comprehensive multiwavelength temporal and spectral analysis of
the FRED GRB 070419A. The early-time emission in the -ray and X-ray
bands can be explained by a central engine active for at least 250 s, while at
late times the X-ray light curve displays a simple power-law decay. In
contrast, the observed behaviour in the optical band is complex (from 10 up
to 10 s). We investigate the light curve behaviour in the context of the
standard forward/reverse shock model; associating the peak in the optical light
curve at 450 s with the fireball deceleration time results in a Lorenz
factor at this time. In contrast, the shallow optical
decay between 450 and 1500 s remains problematic, requiring a reverse shock
component whose typical frequency is above the optical band at the optical peak
time for it to be explained within the standard model. This predicts an
increasing flux density for the forward shock component until t 4
10 s, inconsistent with the observed decay of the optical emission
from t 10 s. A highly magnetized fireball is also ruled out due to
unrealistic microphysic parameters and predicted light curve behaviour that is
not observed. We conclude that a long-lived central engine with a finely tuned
energy injection rate and a sudden cessation of the injection is required to
create the observed light curves - consistent with the same conditions that are
invoked to explain the plateau phase of canonical X-ray light curves of GRBs.Comment: 9 pages, 10 figures, accepted for publication in MNRA
Pleural aspergillosis complicated by recurrent pneumothorax: a case report
<p>Abstract</p> <p>Introduction</p> <p>Pneumothorax as the first symptom of pleural aspergillosis is rare.</p> <p>Case presentation</p> <p>A 31-year-old asthmatic Chinese man presented with recurrent spontaneous pneumothorax and underwent lobectomy due to persistent air leakage. Aspergillus was detected histopathologically in the visceral pleural cavity. He was treated with itraconazole at 200 mg a day, and nine months later he had no recurrent pneumothorax or aspergillus infection.</p> <p>Conclusion</p> <p>Recurrent pneumothorax may be a rare manifestation of aspergillus infection. Aspergillus species infection should be considered in the differential diagnosis of recurrent pneumothorax patients, particularly those with chronic lung disease.</p
Desafios e perspectivas para a integração graduação/pós-graduação em Ciência da Informação: o caso do ICI/UFBA
Chacterization of CU tube filled with Al alloy foam by means of X-ray computer tomography
Copper tubes filled with aluminium foams were prepared by directly foaming metal powder compacts inside them. Compressive behaviour and foam-shell interface, that characterizes mechanical properties of reinforced tubes, were investigated by means of variable focus X-ray computer tomography. Compression tests were performed on empty and filled samples at increasing deformation steps: at each stage the samples were observed by tomography. A geometric evaluation of porosity on 2D sections was performed by calculating, for each pore, its area, equivalent diameter and circularity
Comparison of T-Cell Interferon-γ Release Assays for Mycobacterium tuberculosis-Specific Antigens in Patients with Active and Latent Tuberculosis
Through the use of QuantiFERON-TB Gold, a commercial IFN-γ assay, we compared differences in quantitative T-cell responses to Mycobacterium tuberculosis (MTB)-specific antigens [QuantiFERON TB-2G (QFT-2G)] between patients with active tuberculosis (TB) disease and those with latent TB infection (LTBI). The patient group consisted of 180 patients with active TB disease (culture-positive for MTB) and 50 screening contacts with LTBI-positive response to the QFT-2G test. We prospectively performed a tuberculin skin test (TST) and a QFT-2G test for all subjects. The median IFN-γ levels upon the application of both antigens, ESAT-6 and CFP-10, were significantly higher in patients with active TB disease than in those with LTBI. A combined positive response to both antigens occurred at a higher rate in patients with active TB disease than in those with LTBI. There were no significant relationships between the quantitative responses of IFN-γ to both antigens and the maximum induration on TST in both patient groups. We demonstrated significant differences in the quantitative responses of IFN-γ to MTB between patients with active TB disease and those with LTBI in this study. However, there was an overlap in the IFN-γ levels between active TB disease and LTBI groups. Therefore, it would be difficult to use the QFT-2G test to completely discriminate active TB disease from LTBI
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