Search results for "TRACER"

Intracerebral Hemorrhage and Outcome After Thrombolysis in Stroke Patients Using Selective Serotonin-Reuptake Inhibitors.

2017

Background and Purpose— Selective serotonin-reuptake inhibitors (SSRIs) impair platelet function and have been linked to a higher risk of spontaneous intracerebral hemorrhage—an association that may be augmented by oral anticoagulants (OAC). We aimed to assess whether preadmission treatment with SSRIs in patients with acute ischemic stroke is associated with post-thrombolysis symptomatic intracerebral hemorrhage (sICH) and functional outcome. Methods— A multicenter retrospective analysis was conducted in prospective registries of patients treated by thrombolysis within 4.5 hours of stroke onset. The association between preadmission treatment with SSRIs and sICH (ECASS II definition [Europe…

Optical non-contact electric field mapping by LIF in Cs vapor

2007

We present experimental and theoretical studies of the possibility of using cesium vapor as a tracer gas for optical non-contact electric field mapping. Optical images of electric field distributions have been obtained.

Tracer-Encapsulated Solid Pellet (TESPEL) injection system for the TJ-II stellarator

2016

A tracer-encapsulated solid pellet (TESPEL) injection system for the TJ-II stellarator was recently developed. In order to reduce the time and cost for the development, we combined a TESPEL injector provided by National Institute for Fusion Science with an existing TJ-II cryogenic pellet injection system. Consequently, the TESPEL injection into the TJ-II plasma was successfully achieved, which was confirmed by several pellet diagnostics including a normal-incidence spectrometer for monitoring a tracer impurity behavior.

Development of a Gas Method for Migration Studies in Fractured and Porous Media.

1992

ABSTRACTA gas method for fast measurements of diffusion properties of porous materials has been developed. Diffusion coefficients in the gas phase are typically four orders of magnitude larger than those in the liquid phase. For samples whose structures do not change much upon drying it is possible to estimate the diffpision properties of the liquid phase when the properties of the gas phase are known. Advantages of the gas method are quick and easy measurements and therefore they can be used to optimize the liquid-phase measurements which may last months or years. For materials with good correlation between the gas and liquid-phase diffusion, the number of liquid phase measurements can be …

Validation of matrix diffusion modeling

2010

Abstract Crystalline rock has been chosen as the host medium for repository of highly radioactive spent nuclear fuel in Finland. Radionuclide transport takes place along water-carrying fractures, and matrix diffusion has been indicated as an important retarding mechanism that affects the transport of mobile fission and activation products. The model introduced here for matrix diffusion contains a flow channel facing a porous matrix with stagnant water into which tracer molecules advected in the channel can diffuse. In addition, the possibility of a finite depth of the matrix and an initial tracer distribution (‘contamination’) in the matrix are included in the model. In order to validate th…

Mass spectrometry analysis of volatile compounds in raw meat for the authentication of the feeding background of farm animals.

2007

The authentication of the conditions of animal production, based on the analysis of meat commercial cuts, is a major challenge on both societal and analytical grounds. The aim of the present work was to propose a method for the extraction of the volatile compounds from ruminant raw muscles trimmed of fat and to assess by mass spectrometry-based techniques the relevance of these compounds for the authentication of the type of feeding offered to the animals. The first step of the study consisted of validating conditions of dynamic headspace (DH) extraction of volatile compounds that enabled us to minimize the appearance of heat-induced artifacts and to maximize the richness of the DH-gas chro…

Neuroprotection by erythropoietin and darbopoietin-alfa following experimental intracerebral hemorrhage

2008

Actinide Sorption Studies Using the Isotopes237Np and239Np

2008

The sorption of Np(V) on γ-Al2O3 and the reference clay mineral kaolinite was studied in batch experiments in the presence and absence of ambient CO2 with 0.1 M NaClO4 as background electrolyte. The short-lived isotope 239Np (t1/2 = 2.36 d) was used instead of 237Np (t1/2 = 2.14 × 106 a) to study the sorption behaviour of Np(V) at environmentally-relevant concentrations, i.e., 7 pM Np. In addition, 239Np served as tracer to measure sorption isotherms over six orders of magnitude in neptunium concentration. γ-Al2O3 served as a reference for clay minerals like kaolinite to investigate the interaction of Np(V) with aluminol groups, which are crucial binding sites of clays.

NMR Hyperpolarization of Established PET Tracers

2018

isotracer: An R package for the analysis of tracer addition experiments

2021

AbstractTracer addition experiments, particularly using isotopic tracers, are becoming increasingly important in a variety of studies aiming at characterizing the flows of molecules or nutrients at different levels of biological organization, from the cellular and tissue levels, to the organismal and ecosystem levels.We present an approach based on Hidden Markov Models (HMM) to estimate nutrient flow parameters across a network, and its implementation in the R package isotracer.The isotracer package is capable of handling a variety of tracer study designs, including continuous tracer drips, pulse experiments, and pulse-chase experiments. It can also take into account tracer decay when radio…