Search results for "CONST"
showing 10 items of 7706 documents
Optical tomography from focus
2007
A model and a method providing a 3D reconstruction of a given translucent object from a series of image acquisitions performed with various focus tunings is proposed. The object is imaged by transmission; refraction, reflection and diffusion effects are neglected. It is modeled as a stack of translucent parallel slices and the acquisition process can be described by a set of linear equations. We propose an efficient inversion technique with O(n) complexity, allowing practical applications with a simple laptop computer in a very reasonable time. Examples of results obtained with a simulated 3D translucent object are presented and discussed.
Evaluation of MRI and cannabinoid type 1 receptor PET templates constructed using DARTEL for spatial normalization of rat brains
2015
Purpose: Image registration is one prerequisite for the analysis of brain regions in magnetic-resonance-imaging (MRI) or positron-emission-tomography (PET) studies. Diffeomorphic anatomical registration through exponentiated Lie algebra (DARTEL) is a nonlinear, diffeomorphic algorithm for image registration and construction of image templates. The goal of this small animal study was (1) the evaluation of a MRI and calculation of several cannabinoid type 1 (CB1) receptor PET templates constructed using DARTEL and (2) the analysis of the image registration accuracy of MR and PET images to their DARTEL templates with reference to analytical and iterative PET reconstruction algorithms. Methods:…
Increasing Stability of EEG Components Extraction Using Sparsity Regularized Tensor Decomposition
2018
Tensor decomposition has been widely employed for EEG signal processing in recent years. Constrained and regularized tensor decomposition often attains more meaningful and interpretable results. In this study, we applied sparse nonnegative CANDECOMP/PARAFAC tensor decomposition to ongoing EEG data under naturalistic music stimulus. Interesting temporal, spectral and spatial components highly related with music features were extracted. We explored the ongoing EEG decomposition results and properties in a wide range of sparsity levels, and proposed a paradigm to select reasonable sparsity regularization parameters. The stability of interesting components extraction from fourteen subjects’ dat…
Optical biosensor-based characterization of anti-double-stranded DNA monoclonal antibodies as possible new standards for laboratory tests.
2009
The serum determination of circulating anti-double-stranded (ds)DNA autoantibodies is a routine measure for the laboratory diagnosis of systemic lupus erythematosus. Since available assays differ substantially and no feasible calibrator is available, the aim of this study was to evaluate a recently introduced surface plasmon resonance (SPR) biosensor chip for binding studies between dsDNA and anti-dsDNA autoantibodies and to demonstrate its usefulness for the characterization of new monoclonal antibody (mAb) standards and standardization of assays. We characterized two human and one murine monoclonal anti-dsDNA antibodies by measuring the kinetic on- and off-rates using the biosensor and ca…
Comparison of the contractile effects of endothelin-1 and sarafotoxin S6b in goat isolated cerebral arteries
1992
1. The effects of endothelium-derived endothelin-1 and snake venom-derived sarafotoxin S6b, peptides with striking structural and functional similarities, were examined and compared in isolated middle cerebral arteries of goats. 2. Endothelin-1 and sarafotoxin S6b contracted cerebral arteries in a concentration-dependent manner. The potency of endothelin-1 (EC50 = 4.9 (3.9-6.2) x 10(-10) M) was about ten times higher than that of sarafotoxin S6b (EC50 = 5.5 (4.4-6.9) x 10(-9) M). The tension returned to basal values after repeated washings and contraction with endothelin-1 could be reproduced. Endothelin-1 and sarafotoxin S6b induced further contraction in arteries precontracted with prosta…
Impairment of the modulatory role of nitric oxide on the endothelin-1-elicited contraction of cerebral arteries: a pathogenetic factor in cerebral va…
1997
OBJECTIVE: Nitric oxide (NO) and endothelin-1 (ET-1) are two endothelium-derived factors probably involved in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage (SAH). Our aim was twofold, i.e., to ascertain whether endothelial and nonendothelial NO modulates the contractile response of cerebral arteries to ET-1 and to analyze whether this relationship might be impaired after experimental SAH. METHODS: Rings of middle cerebral artery from goats in the control group and from goats with SAH were set up for isometric tension recordings. SAH was induced 3 days before the experiments by infusion of 10 ml of autologous arterial blood through a catheter previously inserted into t…
Replication and extension of framing effects to compliance with health behaviors during pandemics
2021
Outbreaks of infectious diseases represent a significant challenge for health authorities around the world Public cooperation and compliance with health recommendations constitute critical steps to stop the spread of such diseases But how should these recommendations be framed to achieve the most desirable outcomes? Across two experiments, we show that the classic Asian Disease Problem (Tversy and Kahneman, 1981) is replicable, regardless of disease type (real vs hypothetical) Thus, people are less (vs more) willing to take risks when information is positively (negatively) framed, irrespective of disease type, although they are generally more risk-averse in real pandemics Furthermore, peopl…
Optimizing the use of linaclotide in patients with constipation-predominant irritable bowel syndrome : an expert consensus report
2017
INTRODUCTION: Irritable bowel syndrome (IBS) is a functional bowel disorder characterized by chronic or recurrent abdominal pain in association with defecation or a change in bowel habits. A predominant disorder of bowel habits, IBS is classified into three main subtypes: constipation-predominant IBS (IBS-C), diarrhea-predominant IBS (IBS-D) and IBS alternating between constipation and diarrhea (IBS-M). Linaclotide is a first-in-class, oral, once-daily guanylate cyclase-C receptor agonist (GC-CA) that is licensed for the symptomatic treatment of moderate-to-severe IBS-C in adults. This review aims to facilitate and optimize clinical practices, establishing common guidelines to monitor patie…
Guía de práctica clínica del síndrome del intestino irritable con estreñimiento y estreñimiento funcional en adultos: tratamiento. (Parte 2 de 2)
2017
En esta Guía de práctica clínica analizamos el manejo diagnóstico y terapéutico de pacientes adultos con estreñimiento y molestias abdominales, bajo la confluencia del espectro del síndrome del intestino irritable y el estreñimiento funcional. Ambas patologías están encuadradas en los trastornos funcionales intestinales y tienen una importante repercusión personal, sanitaria y social, afectando a la calidad de vida de los pacientes que las padecen. La primera es el subtipo de síndrome del intestino irritable en el que el estreñimiento es la alteración deposicional predominante junto con dolor abdominal recurrente, hinchazón y distensión abdominal frecuente. El estreñimiento se caracteriza p…
Clinical Cases on Colorectal Cancer Emergency
2019
You have to manage in the emergency room a 75-year-old man with a medical history of pulmonary embolism 4 months ago and currently treated with warfarin. He has no history of abdominal surgery. He consults for diffuse abdominal pain, cessation of flatus and stools for 4 days, and fever of 38.7 °C and chills for 24 h. He vomited once 24 h ago. He also experienced asthenia and recent weight loss of 7 kg over the past 6 months not attributable to diet or exercise. He complains of progressively aggravating alternation of diarrhea and constipation for 3 months. He finally remembers that he noticed several times in the last months the presence of red blood in the stools, about which he did not wo…