The present paper deals with the effect of abiotic environmental stressors on metabolism and growth of fish. Although generally the effect of environmental stressors on metabolism is apparent, the ...extrapolation to growth is not always evident. In stress research it is often difficult to establish borderline levels for chronic stress, so that increased levels of cortisol are used instead to determine when an environment becomes stressful. Because of the observed inconsistency between increased cortisol levels and depressed growth, the question can be raised as to whether cortisol is the most suitable parameter for measuring chronic stress in this context. The absence of a relationship between selected high or low cortisol response lines and growth indicates that differences between experimental animals should also be considered, particularly with respect to the innate stress response. Whether, in view of the possible existence of alternative coping styles, this automatically involves growth, is unclear.
Fourier transform infrared imaging is presented as a new analytical approach in the study of paint cross-sections. Analytical FT-IR reflection imaging provides the spatially resolved acquisition of ...infrared spectra with a resolution of about 7 μm. The technique reveals detailed information on the organic functional group distribution in the individual layers of embedded paint cross-sections and is used complementary to visual microscopy and scanning electron microscopy/energy dispersed X-ray spectroscopy (SEM-EDX). This method was applied to a paint cross-section of Rembrandt's Portrait of a Standing Man (1639). FT-IR imaging of this cross-section identified and localized different compounds present in the layers of this sample. Identification of these compounds based on their infrared spectra is confirmed by results from art historical and conservation literature. Special attention was given to a discoloration that was observed in large parts of the described painting. This discoloration was clearly visible in the paint cross-section. A hypothesis on the nature of the discolored paint layer is formulated based on the FT-IR imaging results.
Different chemical treatments were tested to improve the nutritional value of coffee pulp (CoP): (1) alkali, NaOH solutions of 5 and 10% for 24 and 48
h; (2) a combination of acid and alkali, with ...first a treatment with HCl (1.5 and 3
M for 24 and 48
h), followed by a NaOH solution of 5% for 48
h; (3) A combination of alkali and ensilage, with first a treatment with a NaOH solution of 5% for 48
h, followed by ensilage with molasses (50 and 100
g molasses/kg of CoP) for 2 and 3 months. The CoP treated with NaOH alone or with the combination HCl–NaOH showed higher contents of ash, fat and cellulose but lower contents of antinutritional factors (ANFs) (polyphenols, tannins and caffeine) than oven-dried-CoP (OD-CoP) (
P<0.05). The true protein content in the CoP was not affected by the alkali treatment but was reduced in the acid–alkali treated CoP compared to OD-CoP. A combined treatment with alkali-ensilage resulted in higher true protein, fat and ash contents (
P<0.05) and in similar contents of cellulose than in OD-CoP. Polyphenols, tannins and caffeine contents were lower in treated CoP than in OD-CoP, but there was no difference in the size of the effect for caffeine between one treatment to the other. The higher ash content found in alkali-ensiled CoP could result from the addition of the alkali. The reduction of ANFs was much higher in the chemical treated CoP than in the alkali-ensiled CoP. The alkali treatment yielded the best overall results in upgrading the nutritive value of CoP.
Spectroscopic Imaging Applied to Drug Release Kazarian, S.G.; Kong, K.W.T.; Bajomo, M. ...
Food and bioproducts processing,
06/2005, Volume:
83, Issue:
2
Journal Article, Conference Proceeding
Peer reviewed
Fourier transform infrared (FTIR) imaging is a powerful tool to characterize the distribution of different chemicals in heterogeneous materials. Tremendous potential exists in applications of FTIR ...imaging to dynamic processes in aqueous solutions due to the ability of the focal plane array (FPA) infrared imaging detector to collect many spectra simultaneously and spatially resolved information of a large area at the polymer–water interface.
We have applied FTIR imaging combined with a dissolution test via UV detection in a novel way to study the dissolution of tablets prepared by solid dispersion of drugs in polymer. The advantages of macro ATR imaging in the study of drugs are demonstrated. Concentration profiles of the drug dissolved in water were measured as a function of time, the effects of drug loading is studied and the mechanism of the dissolution of a polymer in water is elucidated. Images of the distribution of drug and polymer, and the evolution of these distributions as a function of time have been obtained. The effects of tablet preparation methods were also investigated using this imaging approach. This study unravels the mechanism of drug release from selected solid dispersions and answers the question pertaining to whether drug release proceeds via polymer degradation or drug diffusion. This FTIR imaging approach has also provided a valuable dataset for the modelling of polymer dissolution and drug release.
This research demonstrates that FTIR imaging can be a powerful tool in the investigation of solid dispersions, polymer/drug interactions and their relevance to controlled drug release processes.
A new method is developed to study drug release using a combination of FTIR imaging and conventional dissolution tests. FTIR imaging in attenuated total reflection (ATR) mode allows simultaneous ...measurements of the distribution of different components in the tablet, e.g., drug, polymer and water as a function of time. These imaging measurements were carried out in a combined compaction and flow-through cell, which was linked to a UV detector to quantify the amount of dissolved drug. In this way, changes in drug concentration in the aqueous solution can be studied similarly to the conventional dissolution test. This combination provides quantitative information of changes in both the tablet and the liquid phase. A tablet composed of hydroxypropyl methylcellulose (HPMC) and niacinamide was prepared and analysed using this setup. Mathematical processing of the measured spectra with a partial least squares (PLS) calibration was utilised for accurate quantitative analysis of the concentrations of different components. The results of FTIR imaging and the dissolution test are compared.
This study describes the changes in the infrared spectra of oil paint as a result of aging. The focus is on the influence of pigments on the long-term changes in the oil binding medium. Several ...naturally aged paints made with different pigments were analysed using Fourier-transform infrared spectroscopy (FTIR). One of the most pronounced effects observed in the infrared spectra of aging paint is the shifting and broadening of the carbonyl band due to the formation of carboxylic acids. Another effect of pigments on the oil binding medium is the catalysis of the hydrolysis of triglycerides, as indicated by the decreasing intensity of the ester absorption. Finally, the nature of the pigment included has a profound effect on the CH stretch absorptions. From these results it is clear that pigments can significantly alter the infrared spectra of drying oil, and should therefore be identified to ensure the correct assessment of the infrared spectra in drying oil paint.
Dronedarone restores sinus rhythm and reduces hospitalization or death in intermittent atrial fibrillation. It also lowers heart rate and blood pressure and has antiadrenergic and potential ...ventricular antiarrhythmic effects. We hypothesized that dronedarone would reduce major vascular events in high-risk permanent atrial fibrillation.
We assigned patients who were at least 65 years of age with at least a 6-month history of permanent atrial fibrillation and risk factors for major vascular events to receive dronedarone or placebo. The first coprimary outcome was stroke, myocardial infarction, systemic embolism, or death from cardiovascular causes. The second coprimary outcome was unplanned hospitalization for a cardiovascular cause or death.
After the enrollment of 3236 patients, the study was stopped for safety reasons. The first coprimary outcome occurred in 43 patients receiving dronedarone and 19 receiving placebo (hazard ratio, 2.29; 95% confidence interval CI, 1.34 to 3.94; P=0.002). There were 21 deaths from cardiovascular causes in the dronedarone group and 10 in the placebo group (hazard ratio, 2.11; 95% CI, 1.00 to 4.49; P=0.046), including death from arrhythmia in 13 patients and 4 patients, respectively (hazard ratio, 3.26; 95% CI, 1.06 to 10.00; P=0.03). Stroke occurred in 23 patients in the dronedarone group and 10 in the placebo group (hazard ratio, 2.32; 95% CI, 1.11 to 4.88; P=0.02). Hospitalization for heart failure occurred in 43 patients in the dronedarone group and 24 in the placebo group (hazard ratio, 1.81; 95% CI, 1.10 to 2.99; P=0.02).
Dronedarone increased rates of heart failure, stroke, and death from cardiovascular causes in patients with permanent atrial fibrillation who were at risk for major vascular events. Our data show that this drug should not be used in such patients. (Funded by Sanofi-Aventis; PALLAS ClinicalTrials.gov number, NCT01151137.).
Raman and infrared microscopy have been used to characterise the black pigments on prehistoric Southwest American black-on-white pottery. Conclusive spectroscopic evidence for the use of carbon-based ...paints on these sherds has been provided using the Raman technique. Maghaemite (γ-Fe
2O
3) and magnetite (Fe
3O
4), found alternatively or mixed with a carbonaceous pigment, were also identified on some sherds. Infrared measurements indicated that little, if any, organic material from biogenic precursors of the black pigment or from pigment binding agents remained in the paints. These spectroscopic results were obtained rapidly and non-destructively on unprepared samples, and the resulting data complement, and in some instances correct, paint type conclusions drawn from studies involving techniques such as XRD, SEM-EDX, and XPS.
Macroscopic attenuated total reflection (ATR) infrared imaging is applied to study the dissolution of realistically sized hydroxypropyl methylcellulose (HPMC) tablets. The water intake into in situ ...compacted tablets and pre-compacted tablets was studied as a function of compaction pressure. Rigorous analysis of the imaging datasets show that the speed of water intake into HPMC tablet is approximately 4 μm/min and is hardly affected by the studied range of compaction pressures or the type of ATR crystal used (diamond or ZnSe). This constant speed of water intake implies that leakage (“creeping”) of water into the space between the tablet and the ATR crystal does not occur. It is shown that the radius of the HPMC tablet initially expands to twice the original radius due to swelling.
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