124 research outputs found
Comparative study of imaging at 3.0 T versus 1.5 T of the knee
The objectives of the study were to compare MR imaging at 1.5 and 3.0 T in the same patients concerning image quality and visualization of cartilage pathology and to assess diagnostic performance using arthroscopy as a standard of reference.
Twenty-six patients were identified retrospectively as having comparative 1.5 and 3.0 T MR studies of the knee within an average of 102 days. Standard protocols included T1-weighted and fat-saturated intermediate-weighted fast spin-echo sequences in three planes; sequence parameters had been adjusted to account for differences in relaxation at 3.0 T. Arthroscopy was performed in 19 patients. Four radiologists reviewed each study independently, scored image quality, and analyzed pathological findings. Sensitivities, specificities, and accuracies in diagnosing cartilage lesions were calculated in the 19 patients with arthroscopy, and differences between 1.5 and 3.0 T exams were compared using paired Student’s t tests with a significance threshold of p < 0.05.
Each radiologist scored the 3.0 T studies higher than those obtained at 1.5 T in visualizing anatomical structures and abnormalities (p < 0.05). Using arthroscopy as a standard of reference, diagnosis of cartilage abnormalities was improved at 3.0 T with higher sensitivity (75.7% versus 70.6%), accuracy (88.2% versus 86.4%), and correct grading of cartilage lesions (51.3% versus 42.9%). Diagnostic confidence scores were higher at 3.0 than 1.5 T (p < 0.05) and signal-to-noise ratio at 3.0 T was approximately twofold higher than at 1.5 T.
MRI at 3.0 T improved visualization of anatomical structures and improved diagnostic confidence compared to 1.5 T. This resulted in significantly better sensitivity and grading of cartilage lesions at the knee
Bowel management for the treatment of pediatric fecal incontinence
Fecal incontinence is a devastating underestimated problem, affecting a large number of individuals all over the world. Most of the available literature relates to the management of adults. The treatments proposed are not uniformly successful and have little application in the pediatric population. This paper presents the experience of 30 years, implementing a bowel management program, for the treatment of fecal incontinence in over 700 pediatric patients, with a success rate of 95%. The main characteristics of the program include the identification of the characteristics of the colon of each patient; finding the specific type of enema that will clean that colon and the radiological monitoring of the process
Identification and developmental expression of the full complement of Cytochrome P450 genes in Zebrafish
© The Authors, 2010. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in BMC Genomics 11 (2010): 643, doi:10.1186/1471-2164-11-643.Increasing use of zebrafish in drug discovery and mechanistic toxicology demands knowledge of cytochrome P450 (CYP) gene regulation and function. CYP enzymes catalyze oxidative transformation leading to activation or inactivation of many endogenous and exogenous chemicals, with consequences for normal physiology and disease processes. Many CYPs potentially have roles in developmental specification, and many chemicals that cause developmental abnormalities are substrates for CYPs. Here we identify and annotate the full suite of CYP genes in zebrafish, compare these to the human CYP gene complement, and determine the expression of CYP genes during normal development. Zebrafish have a total of 94 CYP genes, distributed among 18 gene families found also in mammals. There are 32 genes in CYP families 5 to 51, most of which are direct orthologs of human CYPs that are involved in endogenous functions including synthesis or inactivation of regulatory molecules. The high degree of sequence similarity suggests conservation of enzyme activities for these CYPs, confirmed in reports for some steroidogenic enzymes (e.g. CYP19, aromatase; CYP11A, P450scc; CYP17, steroid 17a-hydroxylase), and the CYP26 retinoic acid hydroxylases. Complexity is much greater in gene families 1, 2, and 3, which include CYPs prominent in metabolism of drugs and pollutants, as well as of endogenous substrates. There are orthologous relationships for some CYP1 s and some CYP3 s between zebrafish and human. In contrast, zebrafish have 47 CYP2 genes, compared to 16 in human, with only two (CYP2R1 and CYP2U1) recognized as orthologous based on sequence. Analysis of shared synteny identified CYP2 gene clusters evolutionarily related to mammalian CYP2 s, as well as unique clusters. Transcript profiling by microarray and quantitative PCR revealed that the majority of zebrafish CYP genes are expressed in embryos, with waves of expression of different sets of genes over the course of development. Transcripts of some CYP occur also in oocytes. The results provide a foundation for the use of zebrafish as a model in toxicological, pharmacological and chemical disease research.This work was supported by NIH grants R01ES015912 and P42ES007381 (Superfund Basic Research Program at Boston University) (to JJS). MEJ was a Guest Investigator at the Woods Hole Oceanographic Institution (WHOI) and was supported by grants from the Swedish research council Formas and Carl Trygger's foundation. AK was a Post-doctoral Fellow at WHOI, and was supported by a fellowship from the Japanese Society for Promotion of Science (JSPS). JZ and TP were Guest Students at the WHOI and were supported by a CAPES Ph.D. Fellowship and CNPq Ph.D. Sandwich Fellowship (JZ), and by a CNPq Ph.D. Fellowship (TP), from Brazil
Vibration isolation system with a compact damping system for power recycling mirrors of KAGRA
A vibration isolation system called the Type-Bp system used for power recycling mirrors has been developed for KAGRA, the interferometric gravitational-wave observatory in Japan. A suspension of the Type-Bp system passively isolates an optic from seismic vibration using three main pendulum stages equipped with two vertical vibration isolation systems. A compact reaction mass around each of the main stages allows for achieving sufficient damping performance with a simple feedback as well as vibration isolation ratio. Three Type-Bp systems were installed in KAGRA, and were proved to satisfy the requirements on the damping performance, and also on estimated residual displacement of the optics
KAGRA: 2.5 Generation Interferometric Gravitational Wave Detector
The recent detections of gravitational waves (GWs) reported by LIGO/Virgocollaborations have made significant impact on physics and astronomy. A globalnetwork of GW detectors will play a key role to solve the unknown nature of thesources in coordinated observations with astronomical telescopes and detectors.Here we introduce KAGRA (former name LCGT; Large-scale Cryogenic Gravitationalwave Telescope), a new GW detector with two 3-km baseline arms arranged in theshape of an "L", located inside the Mt. Ikenoyama, Kamioka, Gifu, Japan.KAGRA's design is similar to those of the second generations such as AdvancedLIGO/Virgo, but it will be operating at the cryogenic temperature with sapphiremirrors. This low temperature feature is advantageous for improving thesensitivity around 100 Hz and is considered as an important feature for thethird generation GW detector concept (e.g. Einstein Telescope of Europe orCosmic Explorer of USA). Hence, KAGRA is often called as a 2.5 generation GWdetector based on laser interferometry. The installation and commissioning ofKAGRA is underway and its cryogenic systems have been successfully tested inMay, 2018. KAGRA's first observation run is scheduled in late 2019, aiming tojoin the third observation run (O3) of the advanced LIGO/Virgo network. In thiswork, we describe a brief history of KAGRA and highlights of main feature. Wealso discuss the prospects of GW observation with KAGRA in the era of O3. Whenoperating along with the existing GW detectors, KAGRA will be helpful to locatea GW source more accurately and to determine the source parameters with higherprecision, providing information for follow-up observations of a GW triggercandidate
Application of independent component analysis to the iKAGRA data
We apply independent component analysis (ICA) to real data from a gravitational wave detector for the first time. Specifically, we use the iKAGRA data taken in April 2016, and calculate the correlations between the gravitational wave strain channel and 35 physical environmental channels. Using a couple of seismic channels which are found to be strongly correlated with the strain, we perform ICA. Injecting a sinusoidal continuous signal in the strain channel, we find that ICA recovers correct parameters with enhanced signal-to-noise ratio, which demonstrates the usefulness of this method. Among the two implementations of ICA used here, we find the correlation method yields the optimal results for the case of environmental noise acting on the strain channel linearly
Search for subsolar-mass black hole binaries in the second part of Advanced LIGO’s and Advanced Virgo’s third observing run
We describe a search for gravitational waves from compact binaries with at least one component with mass 0.2–1.0 M and mass
ratio q ≥ 0.1 in Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) and Advanced Virgo data collected
between 2019 November 1, 15:00 UTC and 2020 March 27, 17:00 UTC. No signals were detected. The most significant candidate
has a false alarm rate of 0.2 yr−1. We estimate the sensitivity of our search over the entirety of Advanced LIGO’s and Advanced
Virgo’s third observing run, and present the most stringent limits to date on the merger rate of binary black holes with at least one
subsolar-mass component. We use the upper limits to constrain two fiducial scenarios that could produce subsolar-mass black
holes: primordial black holes (PBH) and a model of dissipative dark matter. The PBH model uses recent prescriptions for the
merger rate of PBH binaries that include a rate suppression factor to effectively account for PBH early binary disruptions. If the
PBHs are monochromatically distributed, we can exclude a dark matter fraction in PBHs fPBH 0.6 (at 90 per cent confidence)
in the probed subsolar-mass range. However, if we allow for broad PBH mass distributions, we are unable to rule out fPBH = 1.
For the dissipative model, where the dark matter has chemistry that allows a small fraction to cool and collapse into black holes,
we find an upper bound fDBH < 10−5 on the fraction of atomic dark matter collapsed into black holes
Search for subsolar-mass black hole binaries in the second part of Advanced LIGO's and Advanced Virgo's third observing run
We describe a search for gravitational waves from compact binaries with at
least one component with mass 0.2 -- and mass ratio in Advanced LIGO and Advanced Virgo data collected between 1 November
2019, 15:00 UTC and 27 March 2020, 17:00 UTC. No signals were detected. The
most significant candidate has a false alarm rate of 0.2 . We
estimate the sensitivity of our search over the entirety of Advanced LIGO's and
Advanced Virgo's third observing run, and present the most stringent limits to
date on the merger rate of binary black holes with at least one subsolar-mass
component. We use the upper limits to constrain two fiducial scenarios that
could produce subsolar-mass black holes: primordial black holes (PBH) and a
model of dissipative dark matter. The PBH model uses recent prescriptions for
the merger rate of PBH binaries that include a rate suppression factor to
effectively account for PBH early binary disruptions. If the PBHs are
monochromatically distributed, we can exclude a dark matter fraction in PBHs
(at 90% confidence) in the probed subsolar-mass
range. However, if we allow for broad PBH mass distributions we are unable to
rule out . For the dissipative model, where the dark matter
has chemistry that allows a small fraction to cool and collapse into black
holes, we find an upper bound on the fraction of
atomic dark matter collapsed into black holes.Comment: https://dcc.ligo.org/P220013
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