Dietary fat effect on incorporation and release of lipids and cholesterol by rat intestinal slices

The effect of saturated and unsaturated fats on in vitro formation and release of lipids and cholesterol from¹⁴C acetate by rat intestinal tissue was investigated. The rats were fed a basal diet enriched with either 25% corn oil or lard and then sacrificed after a 10- or 25-day feeding period. It was observed that a similar¹⁴C lipid content but a greater¹⁴C cholesterol content was found in the intestinal tissue of rats fed corn oil than in rats fed lard for 10 days. After a longer period of feeding of 25 days, the intestinal tissue¹⁴C cholesterol level was decreased in the corn oil fed rats without any significant effect on other lipids. These data suggest that corn oil in some way influences cholesterol biosynthesis depending upon its degree of unsaturation and the period of time for which it is fed. The decrease at the later time might involve some mechanism which aids in getting rid of accumulated tissue cholesterol. Less¹⁴C lipid and¹⁴C cholesterol were released by the intestinal tissue of rats fed the unsaturated fat as compared with those fed the saturated fat, suggesting a possible role in vivo in reducing blood lipids and blood cholesterol levels. Robert A. Welch Foundation.     

Thickness-dependent electrochromic properties of solution thermolyzed tungsten oxide thin films

Tungsten oxide (WO₃) thin films are prepared by using a simple and inexpensive solution thermolysis technique. Thin film samples of different thickness are obtained by varying quantity of ammonium tungstate solution sprayed onto the preheated conducting glass substrate. A simple three-electrode cell has been formed to study the electrochemical and electrochromic properties. The electrochemical parameters of the cell such as anodic peak current, anodic peak potential, threshold voltage, amount of H⁺ ions intercalated into and deintercalated out of the WO₃ samples are calculated. The effect of film thickness on these parameters are studied. The extent of electrochromism and reversibility of the colouration/bleaching processes of various WO₃ samples are described. The colouration efficiencies at 633 nm are calculated. The maximum colouration efficiency obtained for thicker film, is 56 cm²/C. The samples were found to be stable in 0.05N H₂SO₄ electrolyte up to 1×10³ colour/bleach cycles.     

What About Spectrum Opportunities in ‘Angle’ Dimension for Dynamic Spectrum Access in Cognitive Radio Network context? A new Paradigm in Spectrum Sensing

The cognitive radio technology is the new paradigm to fulfill ever increasing need of bandwidth ultimately the radio spectrum by accommodating the radio spectrum dynamically to secondary users/unlicensed users without causing the interference. In cognitive radio, the spectrum opportunities have been checked for Space, Time and frequency dimensions but ‘Angle’ dimension has not been explored till now. In this paper we have investigated accuracy of various ‘Angle-of-Arrival (AoA)’ estimation algorithms: ESPRIT, MUSIC, Bartlett, and Capon for opportunistic secondary users’ network under AWGN and time varying fading channels. The improvement in performance of these algorithms has been observed as array elements, signal-to-noise ratio and samples increases. An ‘adaptive thresholding’ technique has been proposed to improve the performance of AoA algorithms. Thus by estimating an ‘Angle-of- Arrival’ of licensed users, the unlicensed users can be accommodated in the same geographical area into the same channel in the same frequency band at the same time by directing unlicensed users’ beam in different direction than the direction of licensed users. Thereby improving spectrum utilization.     

Photoelectrochemically active surfactant free single step hydrothermal mediated titanium dioxide nanorods

Titanium dioxide (TiO₂) nanorods have been successfully synthesized by a simple and cost-effective hydrothermal deposition method onto the conducting glass substrates. Effect of reaction temperature on the growth of TiO₂ nanorods have been investigated by varying the reaction temperature from 140 to 200 °C. The optical, structural, compositional, morphological properties of the synthesized films are studied. X-ray diffraction patterns reveal the formation of polycrystalline TiO₂ with the tetragonal crystal structure possessing rutile phase. The chemical composition and valence states of the constituent elements were analysed by X-ray photoelectron spectroscopy. Field emission scanning electron microscopy images shows the formation of nanorod-like structure with variation in diameter. The optical band gap energy was found to increase from 3.07 to 3.15 eV with the increase in reaction temperature exhibiting a blue shift. The films were photo electrochemically active with the maximum current density of 216 µA/cm² for the sample prepared at 180 °C.     

Synthesis of cadmium sulfide spongy balls with nanoconduits for effective light harvesting

Thin films of cadmium sulfide (CdS) consisting of spongy balls with nanoconduits have been chemically synthesized at 70 °C from an aqueous alkaline bath onto soda lime glass and fluorine-doped tin oxide (FTO)-coated glass substrates. The synthesized spongy balls of CdS were characterized using X-ray diffraction (XRD), UV–vis spectroscopy, scanning electron microscopy (SEM), Fourier transform Raman spectroscopy (FT-Raman) and X-ray photoelectron spectroscopy (XPS). The XRD pattern revealed the formation of CdS particles with a cubic crystal structure. SEM micrographs show that the spongy ball-like morphology is composed of nanoconduits. Such spongy balls with nanoconduits that contain numerous nanowalls are a facile way to trap light. The light absorption path length of a photon increases in the nanoconduits and thus can participate in multiple scattering and absorption. This is beneficial for effective light harvesting and improvement in the power conversion efficiency of solar cells.     

Effect of inhibitors and phenobarbital pretreatment upon hepatic lipid peroxidation during protein and riboflavin dietary stress in male rats

Male young albino rats divided into three groups were maintained on the following diets. The normal group was maintained on 13% casein, 45% corn starch, 31% sucrose, 6% salt mixture, 4% peanut oil, and 1% vitamin mixture. The low protein group animals recieved only 5% casein, and the riboflavin-deficient group was fed normal diet, except that the riboflavin was absent from the vitamin mixture and ordinary casein was replaced by 13% vitamin-free casein. The effects of various inhibitors upon triphosphopyridine nucleotide, reduced form-linked lipid peroxide formation by the supernatant fraction of liver at 9000 × g from rats fed a normal diet, a low protein diet, or a riboflavin-deficient diet for 2,4, and 7 weeks were investigated. A significant decrease in triphosphoryridine nucleotide, reduced form-linked and ascorbate-induced lipid peroxidation was noticed in rats fed on low protein and riboflavin-deficient diet. Glutathione inhibited the triphosphopyridine nucleotide, reduced form-linked lipid peroxidation in rats from all three groups. However, the observed response was variable due to the nature of the diet. The magnitude of inhibition was greater in low protein-fed animals than in animals from the riboflavin-deficient and control groups. Cytochrome C inhibited peroxide formation, but the inhibition was greater in rats from the low protein and riboflavin-deficient groups than in animals from the normal group. Tocopherol exhibited the antioxidant property in all three groups of rats. Deoxycholate inhibited lipid peroxide formation in all the three groups.     

Effect of aluminum doping on the properties of PEC cells formed with CdS:Al films

Aluminum doped and undoped CdS films were prepared by chemical bath deposition technique and the photoelectrochemical (PEC) properties have been studied by forming doped CdS/NaOHNa₂SS/C junction. Better results are obtained with 0.1 wt% Al doped CdS films. These results are discussed with the help of the optical and transport properties of the Al doped CdS films.