42,890 research outputs found
Estimates for the ergodic measure and polynomial stability of plane stochastic curve shortening flow
We establish moment estimates for the invariant measure of a stochastic
partial differential equation describing motion by mean curvature flow in (1+1)
dimension, leading to polynomial stability of the associated Markov semigroup.
We also prove maximal dissipativity for the related Kolmogorov operator
Initial results of finger imaging using Photoacoustic Computed Tomography
We present a photoacoustic computed tomography investigation on a healthy
human finger, to image blood vessels with a focus on vascularity across the
interphalangeal joints. The cross-sectional images were acquired using an
imager specifically developed for this purpose. The images show rich detail of
the digital blood vessels with diameters between 100 m and 1.5 mm in
various orientations and at various depths. Different vascular layers in the
skin including the subpapillary plexus could also be visualized. Acoustic
reflections on the finger bone of photoacoustic signals from skin were visible
in sequential slice images along the finger except at the location of the joint
gaps. Not unexpectedly, the healthy synovial membrane at the joint gaps was not
detected due to its small size and normal vascularization. Future research will
concentrate on studying digits afflicted with rheumatoid arthritis to detect
the inflamed synovium with its heightened vascularization, whose
characteristics are potential markers for disease activity.Comment: 2 figure
Using probe electrospray ionization mass spectrometry and machine learning for detecting pancreatic cancer with high performance
A rapid blood-based diagnostic modality to detect pancreatic ductal adenocarcinoma (PDAC) with high accuracy is an unmet medical need. The study aimed to validate a unique diagnosis system using Probe Electrospray Ionization Mass Spectrometry (PESI-MS) and Machine Learning to the diagnosis of PDAC. Peripheral blood samples were collected from a total of 322 consecutive PDAC patients and 265 controls with a family history of PDAC. Five Āµl of serum samples were analyzed using PESI-MS system. The mass spectra from each specimen were then fed into machine learning algorithms to discriminate between control and cancer cases. A total of 587 serum samples were analyzed. The sensitivity of the machine learning algorithm using PESI-MS profiles to identify PDAC is 90.8% with specificity of 91.7% (95% CI 83.9%-97.4% and 82.8%-97.7% respectively). Combined PESI-MS profiles with age and CA19-9 as predictors, the accuracy for stage 1 or 2 of PDAC is 92.9% and for stage 3 or 4 is 93% (95% CI 86.3-98.2; 87.9-97.4 respectively). The accuracy and simplicity of the PESI-MS profiles combined with machine learning provide an opportunity to detect PDAC at an early stage and must be applicable to the examination of at-risk populations. [Abstract copyright: AJTR Copyright Ā© 2020.
Magnetic Properties of Dilute Alloys: Equations for Magnetization and its Structural Fluctuations
The dilute Heisenberg ferromagnet is studied taking into account fluctuations
of magnetization caused by disorder. A self-consistent system of equations for
magnetization and its mean quadratic fluctuations is derived within the
configurationally averaged two-time temperature Green's function method. This
system of equations is analised at low concentration of non-magnetic
impurities. Mean relative quadratic fluctuations of magnetization are revealed
to be proportional to the square of concentration of impurities.Comment: 16 pages, LaTe
Yang-Yang thermodynamics on an atom chip
We investigate the behavior of a weakly interacting nearly one-dimensional
(1D) trapped Bose gas at finite temperature. We perform in situ measurements of
spatial density profiles and show that they are very well described by a model
based on exact solutions obtained using the Yang-Yang thermodynamic formalism,
in a regime where other, approximate theoretical approaches fail. We use
Bose-gas focusing [Shvarchuck etal., Phys. Rev. Lett. 89, 270404 (2002)] to
probe the axial momentum distribution of the gas, and find good agreement with
the in situ results.Comment: extended introduction and conclusions, and minor changes throughout;
accepted for publication in Phys. Rev. Let
Hepatic artery thrombosis after pediatric liver transplantation a medical or surgical event
Hepatic artery thrombosis (HAT) is one of the most serious complications after orthotopic liver transplanĀ¬tation, and is associated with a high morbidity and morĀ¬tality. This study retrospectively reviewed 66 liver transplants in children under the age of 10 years during1 a year-long period at a single institution.;A, total of 28 perioperative variables were analyzed to identify responsible factors of HAT. Of the 66 children, 18 (26%) developed HAT within 15 days after the transplant (HAT group); 29 (42%) had an uneventful postoperative course (control group). To avoid the possible influence of other complications 19 patients were excluded. Of the variables compared between the 2 study groups, three surgical factors (diameter of the hepatic artery-- greater or less than 3 mm; type of arterial anastomosisāend-to-end versus the use of an iliac graft or aortic conduit; and number of times the anastomosis was redone--one versus more than one), were found to be significantly different (P<.05) between HAT and control groups. Two medical factors also were significantly different: the use of intraoperative transfusion of fresh frozen plasma (FFP) and the administration of postoperative prophylactic anticoagulant treatment. A heparin and dextran-40 protocol appeared to be effective in preventing HAT (P<.02). Moreover, after multivariate analysis, anticoagulation therapy was demonstrated to with poor hepatic artery flow. Ā© 1989 by The Williams and Wilkins Co
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