1,121 research outputs found
On the Sensitivity of a Hollow Sphere as a Multi-modal Resonant Gravitational Wave Detector
We present a numerical analysis to simulate the response of a spherical
resonant gravitational wave detector and to compute its sensitivity. Under the
assump- tion of optimal filtering, we work out the sensitivity curve for a
sphere first taking into account only a single transducer, and then using a
coherent analysis of the whole set of transducers.Comment: 24 pages, 11 figures, published versio
Porto-sinusoidal vascular disorder.
It is well established that portal hypertension can occur in the absence of cirrhosis, as reported in patients with immune disorders, infections and thrombophilia. However, similar histological abnormalities primarily affecting the hepatic sinusoidal and (peri)portal vasculature have also been observed in patients without portal hypertension. Thus, the term porto-sinusoidal vascular disorder (PSVD) has recently been introduced to describe a group of vascular diseases of the liver featuring lesions encompassing the portal venules and sinusoids, irrespective of the presence/absence of portal hypertension. Liver biopsy is fundamental for PSVD diagnosis. Specific histology findings include nodular regenerative hyperplasia, obliterative portal venopathy/portal vein stenosis and incomplete septal fibrosis/cirrhosis. Since other conditions including alcohol-related and non-alcoholic fatty liver disease, or viral hepatitis, or the presence of portal vein thrombosis may occur in patients with PSVD, their relative contribution to liver damage should be carefully assessed. In addition to histology and clinical diagnostic criteria, imaging and non-invasive tests such as liver and spleen stiffness measurements could aid in the diagnostic workup. The introduction of PSVD as a novel clinical entity will facilitate collaborative studies and investigations into the underlying molecular pathomechanisms encompassed by this term
Sensitivity of the spherical gravitational wave detector MiniGRAIL operating at 5 K
We present the performances and the strain sensitivity of the first spherical
gravitational wave detector equipped with a capacitive transducer and read out
by a low noise two-stage SQUID amplifier and operated at a temperature of 5 K.
We characterized the detector performance in terms of thermal and electrical
noise in the system output sygnal. We measured a peak strain sensitivity of
at 2942.9 Hz. A strain sensitivity of better than
has been obtained over a bandwidth of 30 Hz. We expect
an improvement of more than one order of magnitude when the detector will
operate at 50 mK. Our results represent the first step towards the development
of an ultracryogenic omnidirectional detector sensitive to gravitational
radiation in the 3kHz range.Comment: 8 pages, 5 figures, submitted to Physical Review
Demonstration of Weak-Link Physics in the Dynamical Response of Transition-Edge Sensors
We theoretically predict and experimentally observe the onset of weak-link
physics in the dynamical response of transition edge sensors (TES). We develop
a theoretical framework based on a Fokker-Planck description that unifies the
TES electrical response, stemming from Josephson phenomena, with electrothermal
effects due to coupling to a thermal bath. Our measurements of a varying
dynamic resistance are in excellent agreement with our theory, thereby ruling
out predictions based on a two-fluid model and establishing weak-link phenomena
as the main mechanism underlying the operation of TES. Furthermore, our
description enables the calculation of power spectral densities, paving the way
for a more thorough investigation of the unexplained "excess noise" in long
diffusive junctions and TES reported in recent experiments
Treatment of refractory ascites with an automated low flow ascites pump in patients awaiting liver transplantation
Efficacy and Safety of Direct-Acting Oral Anticoagulants Use in Acute Portal Vein Thrombosis Unrelated to Cirrhosis
In acute portal vein thrombosis (APVT) unrelated to cirrhosis, anticoagulant therapy is classically started with low molecular weight heparin or vitamin K antagonists. New direct-acting oral anticoagulants (DOACs) are used in the treatment of venous thrombosis outside the splanchnic vascular bed, but not in the latter. We report a young female with APVT occurring in a non-cirrhotic liver linked to heterozygosity of factor V-Leiden and prothrombin G20210A gene mutations. Rivaroxaban was started, with total recanalization of the left and partial recanalization of the right portal vein branches, without complications. New DOACs do not need daily subcutaneous injections nor routinely blood coagulation control tests, making its use attractive, eventually increasing patient's compliance. If proved to be safe and effective in the future studies, its use may be extended to PVT treatment. This case shows that rivaroxaban was safe, not only prevented the extension of thrombosis in the portal tract, but also resolved PVT, at least partially.info:eu-repo/semantics/publishedVersio
MiniGRAIL progress report 2004
The MiniGRAIL detector was improved. The sphere was replaced by a slightly larger one, having a diameter of 68 cm (instead of 65 cm), reducing the resonant frequency by about 200 Hz to around 2.9 kHz. The last four masses of the attenuation system were machined to increase their resonant frequency and improve the attenuation around the resonant frequency of the sphere. In the new sphere, six holes were machined on the TIGA positions for easy mounting of the transducers. During the last cryogenic run, two capacitive transducers and a calibrator were mounted on the sphere. The first transducer was coupled to a double-stage SQUID amplifier having a commercial quantum design SQUID as a first stage and a DROS as a second stage. The second transducer was read by a single-stage quantum design SQUID. During the cryogenic run, the sphere was cooled down to 4 K. The two-stage SQUID had a flux noise of about 1.6 μ0 Hz−1/2. The detector was calibrated and the sensitivity curve of MiniGRAIL was determined
A Metabolomic Analysis of Cirrhotic Ascites.
Ascites is a common complication of decompensated liver cirrhosis, and yet relatively little is known about its biochemical composition. We conducted two metabolomic investigations, comparing the profile of ascites from 33 cirrhotic patients and postoperative peritoneal drainage fluid from 33 surgical patients (Experiment 1). The profile of paired ascites and plasma was also compared in 17 cirrhotic patients (Experiment 2). Gas chromatography-mass spectrometry-based metabolomics identified 29 metabolites that significantly characterized ascites fluid, whether postoperative drainage fluid or plasma were used as controls. Ten elevated amino acids (glutamine, proline, histidine, tyrosine, glycine, valine, threonine, methionine, lysine, phenylalanine) and seven diminished lipids (laurate, myristate, palmitate, oleate, vaccenate, stearate, cholesterol) largely comprised the cirrhotic ascites metabolomic phenotype that differed significantly (adjusted p < 0.002 to 0.03) from peritoneal drainage fluid or plasma. The pattern of upregulated amino acids in cirrhotic ascites did not indicate albumin proteolysis by peritoneal bacteria. Bidirectional clustering showed that the more severe the cirrhosis, the lower the lipid concentration in ascitic fluid. The metabolomic compartment of ascites in patients with decompensated cirrhosis is characterized by increased amino acids and decreased lipids. These novel findings have potential relevance for diagnostic purposes
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