882 research outputs found
Ultrasound Versus Contrast-Enhanced Magnetic Resonance Imaging for Subclinical Synovitis and Tenosynovitis: A Diagnostic Performance Study
OBJECTIVES: Radiographic manifestations of synovitis (e.g., erosions) can be observed only in the late stage of rheumatoid arthritis. Ultrasound is a noninvasive, cheap, and widely available technique that enables the evaluation of inflammatory changes in the peripheral joint. In the same way, dynamic contrast-enhanced magnetic resonance imaging (MRI) enables qualitative and quantitative measurements. The objectives of the study were to compare the sensitivity and accuracy of ultrasound in detecting subclinical synovitis and tenosynovitis with those of contrast-enhanced MRI. METHODS: The ultrasonography and contrast-enhanced MRI findings of the wrist, metacarpophalangeal, and proximal interphalangeal joints (n=450) of 75 patients with a history of joint pain and morning stiffness between 6 weeks and 2 years were reviewed. The benefits score was evaluated for each modality. RESULTS: The ultrasonic findings showed inflammation in 346 (77%) joints, while contrast-enhanced MRI found signs of early rheumatoid arthritis in 372 (83%) joints. The sensitivities of ultrasound and contrast-enhanced MRI were 0.795 and 0.855, respectively, and the accuracies were 0.769 and 0.823, respectively. Contrast-enhanced MRI had a likelihood of 0–0.83 and ultrasound had a likelihood of 0–0.77 for detecting synovitis and tenosynovitis at one time. The two imaging modalities were equally competitive for detecting synovitis and tenosynovitis (p=0.055). CONCLUSION: Ultrasound could be as sensitive and specific as contrast-enhanced MRI for the diagnosis of subclinical synovitis and tenosynovitis
Correlation between intercalated magnetic layers and superconductivity in pressurized EuFe2(As0.81P0.19)2
We report comprehensive high pressure studies on correlation between
intercalated magnetic layers and superconductivity in EuFe2(As0.81P0.19)2
single crystal through in-situ high pressure resistance, specific heat, X-ray
diffraction and X-ray absorption measurements. We find that an unconfirmed
magnetic order of the intercalated layers coexists with superconductivity in a
narrow pressure range 0-0.5GPa, and then it converts to a ferromagnetic (FM)
order at pressure above 0.5 GPa, where its superconductivity is absent. The
obtained temperature-pressure phase diagram clearly demonstrates that the
unconfirmed magnetic order can emerge from the superconducting state. In stark
contrast, the superconductivity cannot develop from the FM state that is
evolved from the unconfirmed magnetic state. High pressure X-ray absorption
(XAS) measurements reveal that the pressure-induced enhancement of Eu's mean
valence plays an important role in suppressing the superconductivity and tuning
the transition from the unconfirmed magnetic state to a FM state. The unusual
interplay among valence state of Eu ions, magnetism and superconductivity under
pressure may shed new light on understanding the role of the intercalated
magnetic layers in Fe-based superconductors
Correlation Filter Selection for Visual Tracking Using Reinforcement Learning
Correlation filter has been proven to be an effective tool for a number of
approaches in visual tracking, particularly for seeking a good balance between
tracking accuracy and speed. However, correlation filter based models are
susceptible to wrong updates stemming from inaccurate tracking results. To
date, little effort has been devoted towards handling the correlation filter
update problem. In this paper, we propose a novel approach to address the
correlation filter update problem. In our approach, we update and maintain
multiple correlation filter models in parallel, and we use deep reinforcement
learning for the selection of an optimal correlation filter model among them.
To facilitate the decision process in an efficient manner, we propose a
decision-net to deal target appearance modeling, which is trained through
hundreds of challenging videos using proximal policy optimization and a
lightweight learning network. An exhaustive evaluation of the proposed approach
on the OTB100 and OTB2013 benchmarks show that the approach is effective enough
to achieve the average success rate of 62.3% and the average precision score of
81.2%, both exceeding the performance of traditional correlation filter based
trackers.Comment: 13 pages, 11 figure
Relations of stellar mass between electron temperature-based metallicity of star-forming galaxies in a wide mass range
We select 947 star-forming galaxies from SDSS-DR7 with
[O~{\sc iii}]4363 emission lines
detected at a signal-to-noise {ratio }larger than 5.
Their electron temperatures and direct oxygen abundances are {then
}determined. {W}e
compare the results from different methods. {, the} electron
temperature in {the }low ionization region{,} estimated from {, that} in
{the }high ionization region{,} {is} compared {using} three analysis
relations between {. These} show obvious differences, which
result in some different ionic oxygen abundances. The results of
, , {/} and {/} derived by
using
methods from IRAF and literature are also compared. The ionic
abundances / {are} higher than / for
most
cases. The{ different} oxygen abundances derived from and the
strong-line ratios show {a }clear discrepancy, which is more obvious
following increasing stellar mass and strong-line ratio
. The sample{ of} galaxies from SDSS {with}
detected [O~{\sc iii}]4363 have lower metallicites and
higher {star formation rates}, {so} they may not be typical representatives
of the
whole{ population of} galaxies. Adopting data objects from
{Andrews \& Martini}, {Liang et al.} and {Lee et al.} data, we derive new
relations of stellar mass and metallicity for star-forming
galaxies in a much wider stellar mass range: from
to .Comment: 16 pages, 11 figures, Accepted by Research in Astronomy and
Astrophysic
A clinical study of the effects of lead poisoning on the intelligence and neurobehavioral abilities of children
BACKGROUND: Lead is a heavy metal and important environmental toxicant and nerve poison that can destruction many functions of the nervous system. Lead poisoning is a medical condition caused by increased levels of lead in the body. Lead interferes with a variety of body processes and is toxic to many organs and issues, including the central nervous system. It interferes with the development of the nervous system, and is therefore particularly toxic to children, causing potentially permanent neural and cognitive impairments. In this study, we investigated the relationship between lead poisoning and the intellectual and neurobehavioral capabilities of children. METHODS: The background characteristics of the research subjects were collected by questionnaire survey. Blood lead levels were detected by differential potentiometric stripping analysis (DPSA). Intelligence was assessed using the Gesell Developmental Scale. The Achenbach Child Behavior Checklist (CBCL) was used to evaluate each child’s behavior. RESULTS: Blood lead levels were significantly negatively correlated with the developmental quotients of adaptive behavior, gross motor performance, fine motor performance, language development, and individual social behavior (P < 0.01). Compared with healthy children, more children with lead poisoning had abnormal behaviors, especially social withdrawal, depression, and atypical body movements, aggressions and destruction. CONCLUSION: Lead poisoning has adverse effects on the behavior and mental development of 2–4-year-old children, prescribing positive and effective precautionary measures
The role of 245 phase in alkaline iron selenide superconductors revealed by high pressure studies
Here we show that a pressure of about 8 GPa suppresses both the vacancy order
and the insulating phase, and a further increase of the pressure to about 18
GPa induces a second transition or crossover. No superconductivity has been
found in compressed insulating 245 phase. The metallic phase in the
intermediate pressure range has a distinct behavior in the transport property,
which is also observed in the superconducting sample. We interpret this
intermediate metal as an orbital selective Mott phase (OSMP). Our results
suggest that the OSMP provides the physical pathway connecting the insulating
and superconducting phases of these iron selenide materials.Comment: 32 pages, 4 figure
Neonatal rhesus monkey is a potential animal model for studying pathogenesis of EV71 infection
AbstractData from limited autopsies of human patients demonstrate that pathological changes in EV71-infected fatal cases are principally characterized by clear inflammatory lesions in different parts of the CNS; nearly identical changes were found in murine, cynomolgus and rhesus monkey studies which provide evidence of using animal models to investigate the mechanisms of EV71 pathogenesis. Our work uses neonatal rhesus monkeys to investigate a possible model of EV71 pathogenesis and concludes that this model could be applied to provide objective indicators which include clinical manifestations, virus dynamic distribution and pathological changes for observation and evaluation in interpreting the complete process of EV71 infection. This induced systemic infection and other collected indicators in neonatal monkeys could be repeated; the transmission appears to involve infecting new monkeys by contact with feces of infected animals. All data presented suggest that the neonatal rhesus monkey model could shed light on EV71 infection process and pathogenesis
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