Elucidation of the effects of a high fat diet on trace elements in rabbit tissues using atomic absorption spectroscopy

<p>Abstract</p> <p>Background</p> <p>The mechanism of atherogenesis is not yet fully understood despite intense study in this area. The effects of high fat diet (HFD) on the changes of trace elements [iron (Fe), copper (Cu) and zinc (Zn)] in several tissues of rabbits have not been documented before. Thus, the aim of this study was to elucidate the changes in trace elements in several tissues of rabbits fed on HFD for a period of feeding of 10 weeks.</p> <p>Results</p> <p>The HFD group was fed a NOR rabbit chow supplemented with 1.0% cholesterol plus 1.0% olive oil. Fe, Cu and Zn concentrations were measured in four types of tissue from control and HFD rabbits using atomic absorption spectroscopy (AAS). Comparing HFD rabbits to control rabbits, we found that the highest percentage change of increase of Fe was 95% in lung tissue, while the lowest percentage change of increase of Fe was 7% in kidney tissue; the highest percentage change of decrease of Cu was 16% in aortic tissue, while the lowest percentage change of decrease of Cu was 6% in kidney tissue; and the highest percentage change of decrease of Zn was 71% in kidney tissue, while the lowest percentage change of decrease of Zn was 8% in lung tissue.</p> <p>Conclusions</p> <p>These results suggest that Fe plays a major role in atherogenesis; it may accelerate the process of atherosclerosis probably through the production of free radicals, deposition and absorption of intracellular and extracellular lipids in the intima, connective tissue formation, smooth muscle proliferation, lower matrix degradation capacity and increased plaque stability. Furthermore, inducing anemia in HFD rabbits may delay or inhibit the progression of atherosclerosis. Cu plays a minor role in atherogenesis and Cu supplements may inhibit the progression of atherogenesis, perhaps by reducing the migration of smooth muscle cells from the media to the intima. Zn plays a major role in atherogenesis and that it may act as an endogenous protective factor against atherosclerosis perhaps by reducing lesion Fe content, intracellular and extracellular lipids in the intima, connective tissue formation, and smooth muscle proliferation. These results suggest that it may be possible to use the measurement of changes in trace elements in different tissues of rabbits as an important risk factor during the progression of atherosclerosis.</p

Contribution à l'étude de la gustation des molécules sucrées à travers un processus d'adsorption. Modélisation par la physique statistique

L'adsorption des molécules sucrées sur les sites récepteurs du goût est une étape déterminante dans le mécanisme de la perception de la saveur sucrée. Naturellement, l adsorption se situe à la périphérie dans ce mécanisme. Nous avons réalisé des courbes de réponse psychophysique à l'aide d'un dispositif approprié nommé SMURF pour quatre molécules sucrées: le saccharose, le fructose, le glucose et le maltitol. Par l'intermédiaire de l'ensemble grand canonique un traitement de physique statistique a été utilisé pour le développement des expressions analytiques de la réponse gustative en terme d'adsorption. La modélisation nous a permis d'adopter le modèle double couche pour l'interprétation du phénomène d'adsorption. Les valeurs du nombre de molécules par site trouvées nous ont permis de déterminer le type d'ancrage pour chaque molécule selon la géométrie: un ancrage parallèle et un ancrage perpendiculaire. Nous avons trouvé une corrélation entre le pouvoir sucrant d'une part et l'énergie d'adsorption, la réponse maximale, la solubilité et le taux d'occupation à la concentration seuil d'autre part. En parallèle nous avons réalisé des isothermes d'adsorption du saccharose à l'aide d'une microbalance à quartz (QCM) sur trois couches minces de porphyrine, de calixarène et d'or. La modélisation de ces isothermes par le modèle de BET modifié nous a permis de caractériser l'adsorption à l'aide des paramètres physicochimiques du modèle. Nous avons montré que les nombres de molécules par site et les énergies d'adsorption sont proches de celles de la gustation. Le saccharose présente donc le même comportement sur ces supports que dans le mécanisme de perception du goûtAdsorption of sweet molecules on gustatory receptor sites is a determining step in the mechanism of taste chemoreception. Obviously adsorption is a peripheral event. A SMURF device (Sensory Measuring Unit for Recording Flux) is used to obtain experimental psychophysical curves relative to four sweeteners: sucrose, fructose, glucose and maltitol. Through the grand canonical ensemble a treatment of statistical physics is used to develop analytic expressions of the gustatory response in terms of adsorption. The modeling allowed selecting of the double layer model which is used to interpret the adsorption phenomenon. The variation of the number of adsorbed molecules per site permitted proposing of two types of anchorage of a sweet molecule to the adsorbent surface: the first consists in a parallel anchorage and the second is a perpendicular anchorage. We found out a relationship between sweetness potency of molecules and the physical parameters of the model. Hence, a correlation was found between sweetness potency on the one hand and the maximum response, the solubility, and the occupation rate at threshold concentration on the other. In parallel we carried out using a Quartz Crystal Microbalance (QCM) adsorption isotherms of sucrose on three thin layers of porphyrin, calixarene and gold. The modeling of the isotherms by the modified BET model allowed characterization of the adsorption using physicochemical parameters of the model. We showed that the number of molecules per site and the adsorption energies are similar to those of taste. So the sucrose presents the same behavior on these supports as in taste chemoreceptionREIMS-BU Sciences (514542101) / SudocSudocFranceF

Heavy and trace elements are important diagnostic tools during the progression of atherosclerosis; high cholesterol diet supplemented with high zinc level delays or prevents the progression of atherosclerosis

Abstract: The mechanism of atherogenesis has not yet fully understood despite different studies in this area. The effects of high cholesterol diet (HCD) on the changes of trace elements [iron (Fe), copper (Cu), zinc (Zn), cadmium (Cd) and lead (Pb)] in several tissues of rabbits have not been well documented before. Thus, the aim of this study was to elucidate the changes in heavy and trace elements in several tissues of rabbits fed on HCD and HCD + Zn for feeding period of 12 weeks compared with the control rabbits; as a diagnostic tool during the progression of atherosclerosis as well as an early detection for cardiovascular diseases and stroke. The HCD group was fed a NOR rabbit chow supplemented with 1.0% cholesterol plus 1.0% olive oil. The HCD + Zn group was fed on NOR Purina Certified Rabbit Chow plus 1.0% cholesterol and 1.0% olive oil supplemented with 350 ppm Zn (total estimate 470 ppm Zn) for the same feeding period of time. Fe, Cu, Zn and Cd concentrations were measured in five types of tissue (kidney, heart, lung, aorta, and liver) from control, HCD and HCD + Zn rabbits using ICP-ES. Comparing HCD to control rabbits, we found an increase in Fe, Cu, Pb and Cd levels in kidney, heart, lung, aorta, and liver tissues of rabbits; while a decrease observed in Zn level in kidney, heart, lung, aorta, and liver tissues. Comparing HCD + Zn with the control rabbits, we found that supplementation of Zn to the HCD decreased the levels of Fe, Cu, Pb, and Cd in kidney, heart, lung, aorta, and liver tissues of rabbits. These results demonstrate that Fe plays a major role during the progression of atherosclerosis through the production of free radicals, deposition and absorption of intracellular and extracellular lipids in the intima, connective tissue formation, and smooth muscle proliferation. Furthermore, inducing anemia in HCD rabbits may delay or inhibit the progression of atherosclerosis. Cu plays a minor role in atherosclerosis. Zn plays a major role in atherosclerosis; it may act as an endogenous protective factor against atherosclerosis perhaps by reducing lesion Fe content

Facile synthesis of microporous sulfur-doped carbon spheres as electrodes for ultrasensitive detection of ascorbic acid in food and pharmaceutical products

Fabrication of electrodes based on a metal-free catalyst with desirable sensitivity, selectivity, and stability has been given considerable interest. Microporous sulfur-doped carbon microspheres (S-MCMS) were synthesized and assembled as an electrochemical sensor for the monitoring of ascorbic acid (AA) in commercial juices and vitamin C tablets. The S-doped microporous carbon with a spherical structure was fabricated at different annealing temperatures (700, 800, and 900 °C) to achieve a high surface area, an actively doped carbon interfacial surface, soft interactive surfaces and an open microporous network. The high surface area, actively doped S-atom percentage, microporous construction, and active doping of the carbon microsphere construction of S-MCMS-900, make it a highly stable metal-free electrocatalyst for selective detection of AA. The S-atoms incorporated with the sp2-carbon matrix form numerous active sites, which bind to targets and stimulate the transduction of the electrochemical interaction with a fast response and high charge transfer efficiency. Selective monitoring of AA on S-MCMS-900 with high sensitivity was achieved with a detection limit as low as 1 μM, and wide linear range up to 4 mM. Monitoring of AA in lemon juice or pharmaceutical tablets was realized by using S-MCMS-900, with a fast response, high sensitivity, reliable selectivity, high stability and rational reproducibility. S-MCMS-900 can be employed as a fast, sensitive, and selective assay for routine detection of AA in food, biological, and environmental samples

Investigation of Adsorption Process of Hydrogen on Fe-Ti: Theoretical Simulation and Interpretation of Isotherms with Statistical Physics Treatment

International audienc

Ultraviolet-Visible and Fluorescence Spectroscopy Techniques Are Important Diagnostic Tools during the Progression of Atherosclerosis: Diet Zinc Supplementation Retarded or Delayed Atherosclerosis

Background. In this study, we examined whether UV-visible and fluorescence spectroscopy techniques detect the progression of atherosclerosis in serum of rabbits fed on high-cholesterol diet (HCD) and HCD supplemented with zinc (HCD + Zn) compared with the control. Methods. The control rabbits group was fed on 100 g/day of normal diet. The HCD group was fed on Purina Certified Rabbit Chow supplemented with 1.0% cholesterol plus 1.0% olive oil (100 g/day) for the same period. The HCD + Zn group was fed on normal Purina Certified Rabbit Chow plus 1.0% cholesterol and 1.0% olive oil supplemented with 470 ppm Zn for the same feeding period. UV-visible and fluorescence spectroscopy and biochemistry in Rabbit’s blood serum and blood hematology were measured in Rabbit’s blood. Results. We found that the fluorescent peak of HCD shifted toward UV-visible wavelength compared with the control using fluorescent excitation of serum at 192 nm. In addition, they showed that supplementation of zinc (350 ppm) restored the fluorescent peak closely to the control. By using UV-visible spectroscopy approach, we found that the peak absorbance of HCD (about 280 nm) was higher than that of control and that zinc supplementation seemed to decrease the absorbance. Conclusions. This study demonstrates that ultraviolet-visible and fluorescence spectroscopy techniques can be applied as noninvasive techniques on a sample blood serum for diagnosing or detecting the progression of atherosclerosis. The Zn supplementation to rabbits fed on HCD delays or retards the progression of atherosclerosis. Inducing anemia in rabbits fed on HCD delays the progression of atherosclerosis

Binary adsorption isotherms of two ionic liquids and ibuprofen on an activated carbon cloth: simulation and interpretations using statistical and COSMO-RS models

International audienc

Energetic investigation of the adsorption process of CH4, C 2H6 and N2 on activated carbon: Numerical and statistical physics treatment

The adsorption energy distribution (AED) function of a commercial activated carbon (BDH-activated carbon) was investigated. For this purpose, the integral equation is derived by using a purely analytical statistical physics treatment. The description of the heterogeneity of the adsorbent is significantly clarified by defining the parameter N?m(E). This parameter represents the energetic density of the spatial density of the effectively occupied sites. To solve the integral equation, a numerical method was used based on an adequate algorithm. The Langmuir model was adopted as a local adsorption isotherm. This model is developed by using the grand canonical ensemble, which allows defining the physico-chemical parameters involved in the adsorption process. The AED function is estimated by a normal Gaussian function. This method is applied to the adsorption isotherms of nitrogen, methane and ethane at different temperatures. The development of the AED using a statistical physics treatment provides an explanation of the gas molecules behaviour during the adsorption process and gives new physical interpretations at microscopic levels.Scopus2-s2.0-8488711346