Search results for "absorption."
showing 10 items of 2682 documents
Influence of Chronic Alcohol Intake on Intestinal Taurine and Antipyrine Transport in Pregnant Rats
1998
Taurine is a nonessential amino acid that plays a critical role in development. However, biosynthetic capacity is almost negligible in the fetus and must be supplied by the mother. Therefore, when maternal taurine status is depressed during gestation, fetal tissue taurine concentrations can also be compromised. In the present study, the effect of chronic alcohol intake on the intestinal transport of taurine during pregnancy has been investigated by an in vitro technique that allows measurement of the unidirectional influx of the amino acid across the intact rat mid jejunum. The influence of alcohol intake on the passive component of the intestinal transport was also investigated with antipy…
Experimental Studies on the Influence of Surfactants on Intestinal Absorption of Drugs Cefadroxil as model drug and sodium taurocholate as natural mo…
2011
The influence of the natural bile acid surfactant sodium taurocholate (CAS 81-24-3) on colic and duodenal (i.e. the proximal third of the small intestine) absorption of cefadroxil (CAS 50370-12-2) was studied using the in situ rat gut technique, and compared with the effect of sodium lauryl sulfate (CAS 151-21-3), the most widely used synthetic anionic surfactant. Previously, the stability, compatibility, and micelle-solubilization characteristics of taurocholate were assessed in order to correct, when necessary, the absorption results. White the passive absorption rate constants (kf, h-1) determined in colon in the presence of increasing lauryl sulfate concentrations showed an asymptotic v…
Methods for diagnosing bile acid malabsorption: a systematic review
2019
Abstract Background Bile acid malabsorption (BAM) and bile acid-related diarrhea represent an under-recognized cause of chronic diarrhea mainly because of limited guidance on appropriate diagnostic and laboratory tests. We aimed to perform a systematic review of the literature in order to identify and compare the diagnostic accuracy of different diagnostic methods for patients with BAM, despite a proven gold standard test is still lacking. Methods A PubMed literature review and a manual search were carried out. Relevant full papers, evaluating the diagnostic accuracy of different methods for BAM, were assessed. Available data were analyzed to estimate the sensitivity and specificity of each…
Excited States Calculations of MoS2@ZnO and WS2@ZnO Two-Dimensional Nanocomposites for Water-Splitting Applications
2021
This research was funded by the Latvian Scientific Council grant LZP-2018/2-0083. Institute of Solid State Physics, University of Latvia, as the Center of Excellence, has received funding from the European Union's Horizon 2020 Framework Program H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under Grant Agreement No. 739508, project CAMART2.
Study of High-Temperature Behaviour of ZnO by Ab Initio Molecular Dynamics Simulations and X-ray Absorption Spectroscopy
2021
Wurtzite-type zinc oxide (w-ZnO) is a widely used material with a pronounced structural anisotropy along the c axis, which affects its lattice dynamics and represents a difficulty for its accurate description using classical models of interatomic interactions. In this study, ab initio molecular dynamics (AIMD) was employed to simulate a bulk w-ZnO phase in the NpT ensemble in the high-temperature range from 300 K to 1200 K. The results of the simulations were validated by comparison with the experimental Zn K-edge extended X-ray absorption fine structure (EXAFS) spectra and known diffraction data. AIMD NpT simulations reproduced well the thermal expansion of the lattice, and the pronounced …
Sensing of Transition Metals by Top-Down Carbon Dots
2021
Carbon quantum dots (CQDs) are a new class of carbon-rich materials with a range of unique optical and structural properties. They can be defined as carbon nanoparticles, with sizes in the range of 1–10 nm, displaying absorption and emission activities in the UV-VIS range. Depending on the structure, CQDs display a wide variability of properties, which provides the possibility of finely tuning them for several applications. The great advantages of CQDs are certainly the ease of synthesis, non-toxicity, and the strong interactions with the surrounding environment. Based on this, CQDs are especially promising as selective chemosensors. The present study reports on carbon quantum dots synthesi…
Oxidation State and Local Structure of Chromium Ions in LaOCl
2021
This research is funded by the Latvian Council of Science, project “Novel transparent nanocomposite oxyfluoride materials for optical applications”, project No. LZP-2018/1-0335. Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017- TeamingPhase2 under grant agreement No. 739508, project CAMART2.
Quantitative interpretation of the red edge excitation (REE) effect of 9,9′-bianthryl in polyisobutene by band shape analysis of the temperature-depe…
1994
Optical fluorescence spectra of 9,9′-bianthryl (BA) in polyisobutene (PIB) were measured as a function of the excitation wavelength at various temperatures between 210 and 293 K. Irradiation at the red edge of the absorption spectra selectively excites distinct conformers with respect to the torsional angle. This leads to a strong dependence of the vibronic band shape of the fluorescence spectra on the excitation wavelength. The marked temperature dependence of the band shape may be attributed to the viscosity-dependent deceleration of the torsional relaxation of BA in the highly viscous polymer which prevents the excited state ensemble from reaching thermal equilibrium. The predominant bro…
Treatment of Gaseous Effluents Produced During Electrochemically Assisted Soil Remediation Processes
2021
In many cases, electrochemically assisted soil remediation processes, like electrokinetic or electroheating ones, produce gaseous effluents that need to be collected and treated. Adsorption, absorption, and catalytic and thermal oxidation are often used for the treatment of these gaseous effluents. The chapter describes these technologies reporting their main advantages and disadvantages. Eventually, a comparison of the performances of these technologies was carried out.
(Me3Sn)2SbSb(SnMe3)2, 1∞-verknüpfte SbSb-Hanteln in einem thermochromen Distiban mit Schweratomgerüst
1987
Abstract Single crystals of the thermochromic distibane (Me 3 Sn) 4 Sb 2 ( 1 ) are obtained by irradiation of (Me 3 Sn) 3 Sb with sunlight. The crystal structure of 1 is reported as linear chains of distibane molecules in trans conformation with Sb ⋯ Sb contacts of 389 ppm. Diffuse reflexion spectra of 1 in the solid state and in solution demonstrate thermochromic effect. The Raman spectrum of solid 1 exhibits strong absorption at 162 cm −1 for ν(Sb 2 ).