The implementation of graphene-based aerogel in the field of supercapacitor

Graphene and graphene-based hybrid materials have emerged as an outstanding supercapacitor electrode material primarily because of their excellent surface area, high electrical conductivity, and improved thermal, mechanical, electrochemical cycling stabilities. Graphene alone exhibits electric double layer capacitance (EDLC) with low energy density and high power density. The use of aerogels in a supercapacitor is a pragmatic approach due to its extraordinary properties like ultra-lightweight, high porosity and specific surface area. The aerogels encompass a high volume of pores which leads to easy soak by the electrolyte and fast charge-discharge process. Graphene aerogels assembled into three-dimensional (3D) architecture prevent there stacking of graphene sheets and maintain the high surface area and hence excellent cycling stability and rate capacitance. However, the energy density of graphene aerogels is limited due to EDLC type of charge storage mechanism. Consequently, 3D graphene aerogel coupled with pseudocapacitive materials such as transition metal oxides, metal hydroxides, conducting polymers, nitrides, chalcogenides show an efficient energy density and power density performance due to the presence of both types of charge storage mechanisms. This laconic review focuses on the design and development of graphene-based aerogel in the field of the supercapacitor. This review is an erudite article about methods, technology and electrochemical properties of graphene aerogel.

Esophagobronchial fistulae: Diagnosis by MDCT with oral contrast swallow examination of a benign and a malignant cause

We report two cases of esophagobronchial fistulae diagnosed by Multi-detector computed tomography (MDCT) oral contrast swallow examination. It is helpful to supplement the CT study with an oral contrast swallow as it aids in confirmation of a suspected fistula and also demonstrates the fistula tract better. We present the clinical details and the imaging findings on MDCT of two cases of esophagobronchial fistulae – one secondary to chronic chest tuberculosis and the other secondary to a squamous cell carcinoma of the upper esophagus – followed by discussion of the etiology, pathogenesis, and imaging of these fistulae.

Deviated nasal septum hinders intranasal sprays: a computer simulation study

BACKGROUND

This study investigates how deviated nasal septum affects the quantity and distribution of spray particles, and examines the effects of inspiratory airflow and head position on particle transport.

METHODS

Deposition of spray particles was analysed using a three-dimensional computational fluid dynamics model created from a computed tomography scan of a human nose with leftward septal deviation and a right inferior turbinate hypertrophy. Five simulations were conducted using FluentTM software, with particle sizes ranging from 20-110 μm, a spray speed of 3 m/s, plume angle of 68(deg), and with steady state inspiratory airflow either present (15.7 L/min) or absent at varying head positions.

RESULTS

With inspiratory airflow present, posterior deposition on the obstructed side was approximately four times less than the contralateral side, regardless of head position, and was statistically significant. When airflow was absent, predicted deposition beyond the nasal valve on the left and right sides were between 16% and 69% lower and positively influenced by a dependent head position.

CONCLUSION

Simulations predicted that septal deviation significantly diminished drug delivery on the obstructed side. Furthermore, increased particle penetration was associated with presence of nasal airflow. Head position is an important factor in particle deposition patterns when inspiratory airflow is absent.

Stem cell-like outgrowths from in vitro fertilized goat blastocysts

With an aim to isolate, culture and characterize goat embryonic stem cell-like cells derived from in vitro fertilized goat blastocysts, slaughterhouse derived goat oocytes were in vitro matured in maturation medium in 5% CO2 air at 38.5 degrees C. Matured oocytes were fertilized in vitro with fresh capacitated spermatozoa. Total 636 (36.5%) cleaved embryos were obtained which were further co-cultured with goat oviductal epithelial cells (GOEC) for 7-10 days. GOEC culture system was better for formation of morula (150; 44.3%) and hatched blastocyst (13; 3.8%) than embryo development medium culture system, [morula (69; 23.1%) and hatched blastocyst (5; 1.6%)]. Out of total blastocysts (48) the primary colonies were formed in 23.3% (7/30) blastocysts, and 66.6% (12/18) of hatched blastocysts. The cells of the inner cell mass (ICM) derived primary colonies were small, aggregated and tightly packed in nature forming embryoid bodies on further subculture. The colonies were stained to see the expression of alkaline phosphatase and positive result was obtained. Goat embryonic stem cell like outgrowths were also characterized for Oct-4 expression and positive result was found. It could be concluded that ICM cells were isolated from in vitro fertilized goat blastocysts and cultured for embryonic stem cell-like cells and expression of alkaline phosphatase and Oct-4 in these cells were positive.

Adult type anomalous left coronary artery from pulmonary artery

Anomalous origin of Left Coronary Artery from Pulmonary Artery (ALCAPA) is a rare congenital anomaly. Its survival into adulthood is further rare. Clinical manifestations result from evolving morphological - functional alterations in pulmonary circulation that occur after the birth. We report a case of 43 year old adult patient with effort angina and without any ECG or Echo abnormalities. On coronary angiography, typical anatomy of ALCAPA was revealed.

Rate acceleration and subsequent retardation of Diels-Alder reactions in LiClO4-diethyl ether: an experimental investigation

The experimental kinetic data for several Diels-Alder reactions show why a 5 M LiClO(4)-diethyl ether (LPDE) solution offers maximum enhancement of reaction rates, endo/exo ratios, and yields. These reactions, if carried out in LPDE solutions of concentrations higher than 5 M, show a substantial decrease in these kinetic parameters. This decrease is attributed to the very high viscosity of LPDE solutions near saturation, though this interpretation is not consistent when considered in terms of sizes of the diene and dienophile. The monoetherates, dietherates, and higher other clusters in LPDE solutions and their relationship with the Lewis acid catalysis by Li+ offer a more plausible explanation of both the enhancement and the decrease of the rate of Diels-Alder reactions in this medium.

Effect of inducers on hepatic microsomal mixed function oxidase system of male rats during food restriction

Phenobarbital (PB; 80 mg/kg, ip) or 3-methylcholantrene (3-MC; 20 mg/kg, ip) was administered to Wistar male rats at the end of the feeding period of 30 days and the effects of food restriction (FR) and FR followed by inducer treatment on hepatic drug metabolizing enzymes, microsomal electron transport components, NADPH dependent lipid peroxidation and glutathione-s-transferase activities were studied. In both, PB and 3-MC treatment, the magnitude of increase in microsomal protein content, cytochrome b5 and aminopyrine N-demethylase (APND) activity was less in FR animals than in ad libitum fed; while cytochrome P-450 levels and activities of cytochrome c reductase and acetanilide hydroxylase (ACOH) were higher in FR animals. NADPH dependent lipid peroxidation and cytosolic glutathione-s-transferase activity were also enhanced due to PB and 3-MC treatment but the magnitude of increase was less in FR animals. The ACOH activity increased to a greater extent than APND activity in FR animals following PB and 3-MC treatment. It is suggested that the response to inducers in the FR animals differ from that in the ad libitum fed rats.

Mixed function oxidase system in hepatic and extrahepatic tissues of developing chickens following various treatments

Alterations in hepatic and extrahepatic protein content, activities of drug enzymes, lipid peroxidation and hydrogen peroxide formation and levels of microsomal electron transport components were examined in developing chickens during treatment with phenobarbital (PB), benzene and 1,1,1,-trichloro 2,2, bis (p-chlorophenyl) ethane (DDT) treated group of 4-8 weeks old chickens. Activities of hepatic and extrahepatic (kidney, lung, intestine) tissues enzymes were induced during PB treatment in all groups of chicken. However benzene and DDT treated group of chickens recorded decrease in activities of drug enzymes. Magnitude of increase due to PB administration was much more in liver as compared to kidney, lung and intestine. Hydrogen peroxide and lipid peroxide formation significantly increased in all tissues during treatments of benzene and DDT. Levels of cyto P-450, cyto b5 and cyto c-reductase, lipid peroxidation and hydrogen peroxide formation increased in all groups of chickens during various treatments. The results suggest that chicken liver contains more drug enzyme activities and electron transport components during development as compared to other tissues. Benzene and DDT administration resulted into decrease in the activities of drug enzymes.

Purification of erythrocyte cytochrome P-450 from goat and chick

Cytochrome P-450 has been purified from goat and chick erythrocytes and characterized. Goat erythrocyte cytochrome P-450 content was higher than that of chick erythrocytes cytochrome P-450. Elution profile of purified protein from DEAE-cellulose column showed a single peak. The catalytic activities of aminopyrine-N-demethylase and acetanilide hydroxylase were found to be higher in purified proteins. Molecular weight was determined by SDS-polyacrylamide gel electrophoresis.

Hepatic mixed function oxidase system and effect of phenobarbital, 3-methylcholanthrene and 1, 1, 1-trichloro-2, 2-bis(p-chlorophenyl)ethane in developing chickens

Contents of hepatic microsomal protein, aminopyrine N-demethylase, acetanilide hydroxylase, aniline hydroxylase, hydrogen peroxide formation, cytochrome-c-reductase, cytochrome b5 and cytochrome P-450 were examined in control, phenobarbital (PB), 3-methylcholanthrene (3-MC) and 1, 1, 1-trichloro-2, 2-bis(p-chlorophenyl)ethane (DDT) treated group of 1-28 days old chickens. Increase in aminopyrine N-demethylase, acetanilide hydroxylase, aniline hydroxylase, cytochrome-c-reductase, cytochrome b5 and cytochrome P-450 was noticed at all stages of development during administration of PB and 3-MC. But these enzyme activities were not always paralleled by increase in age. Aminopyrine N-demethylase was increased in early stages only during DDT administration, which indicates that the form of cytochrome P-450, responsible for aminopyrine N-demethylation is present in early stages only. However, acetanilide hydroxylase was decreased in all stages of development, in postnatal development the basal activities of the enzymes for various substrates do not exhibit identical pattern, the degree of inducibility by inducers varied in relation to age of animal. Hydrogen peroxide formation increased in all stages of developing chickens due to the administration of PB and DDT. It however decreased due to 3-MC administration which may be due to induction of high spin cytochrome P-450.

Effect of caffeine on the hepatic microsomal mixed function oxidase system during phenobarbital and benzo[a]pyrene treatment in rats

Simultaneous administration of caffeine (100 mg/kg, i.p., 3 days) and phenobarbital (80 mg/kg, i.p., 3 days) to adult male rats resulted in a significant decrease in hepatic cytochrome P-450 and acetanilide hydroxylase activity, compared to phenobarbital administration alone. While simultaneous administration of caffeine and benzo[a]pyrene (20 mg/kg, i.p., 2 days) increased acetanilide hydroxylase, compared to benzo[a]pyrene administration, no change was seen in the cytochrome P-450 concentration. In vitro addition of 2.5 mM caffeine to microsomal incubations from untreated, phenobarbital- and benzo[a]pyrene-treated rats inhibited aminopyrine N-demethylase activity. No significant difference was seen in the extent of aminopyrine N-demethylase inhibition due to the in vitro addition of caffeine to microsomes from untreated or phenobarbital-treated rats, whereas inhibition in microsomes from benzo[a]pyrene-treated rats was greater.

Alterations in hepatic microsomal mixed-function oxidase system during different levels of food restriction in adult male and female rats

Wistar strain adult male and female rats were given 25, 50 and 75% less food than an ad libitum-fed group of rats for 45 d and the effects of food restriction on hepatic drug metabolizing enzymes, microsomal electron transport components, NADPH-dependent lipid peroxidation and glutathione-S-transferase activities were studied. Compared to ad libitum-fed controls, the cytochrome P-450 levels were higher in food restricted male rats, while they were lower in food restricted females. The activities of NADPH cytochrome c reductase were lower in food restricted females than in ad libitum-fed controls. The activities of drug metabolizing enzymes, aminopyrine N-demethylase and acetanilide hydroxylase were higher in food restricted males, whereas in food restricted females these activities were lower than in respective groups fed ad libitum. Microsomal, NADPH-dependent lipid peroxidation was higher in 25 and 50% food restricted females while in 50 and 75% food restricted males it was lower than in ad libitum controls of the same sex. The cytosolic glutathione-S-transferase activities were lower in food restricted rats of both the sexes than in the same sexed controls. Another group of male and female rats were given 75% less food than the ad libitum-fed rats and refed for 3 d prior to killing. Here also, the effects of restriction were different between sexes. It is concluded that hepatic microsomal mixed-function oxidase system (MFOS) is altered due to feed restriction and food restriction followed by refeeding, in a sex-related manner.

Effect of ampicillin on hepatic microsomal mixed-function oxidase system in male mice

The effect of ampicillin [(D)-alpha-aminobenzyl penicillin] administration on the hepatic mixed-function oxidase (MFO) system was studied in male mice. Ampicillin (100 mg/kg, i.p., 3 days) decreased the levels of cytochrome P-450, aminopyrine N-demethylase, acetanilide hydroxylase and cytochrome c-reductase activity significantly. In carbon tetrachloride (CCl4)-pretreated mice, ampicillin increased acetanilide hydroxylation compared with CCl4 treatment alone; however, all other parameters of the MFO system remained unchanged. Ampicillin exhibited type II binding with microsomes (trough at 388 nm, peak at 430 nm). Thus ampicillin acts as an inhibitor of the MFO system.

Purification and characterization of glutathione-S-transferase from liver cytosol of phenobarbital-treated rabbits

Glutathione-S-transferase (GST) from the liver cytosol of phenobarbital (PB)-treated rabbits was purified by DEAE-cellulose, CM-cellulose and hydroxylapatite column chromatography. Four species of GST were obtained by eluting the CM-cellulose column with a linear KCl gradient, and the major protein investigated. The purified enzyme from PB-treated and untreated rabbit had specific activities of 125.16 units/mg and 72.8 units/mg of protein, respectively, and the apparent Km was 0.6 X 10(-3) M for GSH and 1.6 X 10(-3) M for 1-chloro-2,4-dinitrobenzene. The optimum pH value was 8.7 and the enzyme was able to conjugate with 1-chloro-2,4-dinitrobenzene, 1,2-dichloro-4-nitrobenzene, 1,2-epoxy-3-(p-nitrophenoxy)propane and p-nitrobenzyl chloride.

In vivo and in vitro effects of caffeine on hepatic mixed-function oxidases in rodents and chicks

Administration of caffeine, ip 100 mg/kg/day for 1-5 days, to adult male rats resulted in a significant increase in hepatic cytochrome P-450 and b5 concentrations and in cytochrome c reductase, aminopyrine N-demethylase and acetanilide hydroxylase activities. No change was seen in relative liver weight but microsomal protein content was increased after treatment for 1 day and decreased after treatment for 3 or 5 days. In adult rats given 25, 100 or 150 mg caffeine/kg for 3 days, maximum stimulation of mixed-function oxidases was seen with the 100-mg/kg dose. Caffeine treatment (100 mg/kg for 3 days) increased relative liver weight in female guinea-pigs and decreased it in chicks and female mice, and decreased microsomal protein content in male mice, female guinea-pigs and young rats, and increased it in chicks. A significant increase in hepatic cytochrome P-450 content was seen in all species studied. Cytochrome b5 content was increased in chicks and young rats, while cytochrome c reductase activity was increased in male and female mice, young rats and chicks and decreased in female guinea-pigs. Aminopyrine N-demethylase activity was increased in young rats and female guinea-pigs, and acetanilide hydroxylase was increased in all test species except male mice. In vitro addition of 2.5 mM-caffeine to microsomal incubations from untreated rats, guinea-pigs, mice and chicks inhibited aminopyrine N-demethylase activity, although only to a significant extent in male mice; addition of caffeine to incubations containing microsomes from caffeine-treated animals produced significant inhibition of aminopyrine N-demethylase activity in microsomes from adult and young rats and female guinea-pigs. Aminopyrine N-demethylase inhibition did not increase with increasing concentration of added caffeine, although acetanilide hydroxylase activity was progressively inhibited in the microsomal incubates from both control and caffeine-treated animals.

Effect of sodium fluoride on hepatic microsomal mixed-function oxidase system in newborn and adult male rats

Administration i.p. of sodium fluoride at 2.5 or 5.0 mg/kg induced the mixed-function oxidase system in both newborn and adult rats; at 10.0 mg/kg there was induction in newborn rats and inhibition in adult rats, and at 20.0 mg/kg, there was inhibition in both newborn and adults.

Alterations in drug metabolising enzymes and lipid peroxidation in different rat tissues by fluoride

Sodium fluoride at a dose level of 5.0 mg/kg enhanced aminopyrine N-demethylase and NADPH cytochrome c reductase activities and cytochrome P450 and cytochrome b5 levels in rat liver, kidney, lung, intestine and testis, whereas acetanilide hydroxylase activity remained unchanged in kidney and lung and was increased in liver, intestine and testis. Sodium fluoride at 20.0 mg/kg caused a decrease in aminopyrine N-demethylase, acetanilide hydroxylase and NADPH cytochrome c reductase activities and cytochrome P450 and cytochrome b5 levels in all tissues, except for an increase in NADPH cytochrome c reductase activity in the intestine and testis. Fluoride at both dose levels produced only marginal changes in glutathione-S-transferase activity except for a 4-fold increase in the testis at 5.0 mg/kg. Sodium fluoride at 5.0 mg/kg increased lipid peroxidation in all tissues studied. At 20.0 mg/kg there was a decrease in lipid peroxidation in liver, lung and testis and an increase in kidney and intestine.

Partial inhibition of hepatic microsomal aminopyrine N-demethylase by caffeine in partially purified cytochrome P450

Cytochrome P-450 substrate interactions were studied with cytochrome P-450 partially purified from livers of untreated, phenobarbital-treated, benzo[a]pyrene-treated and caffeine-treated rats. Partial inhibition of aminopyrine N-demethylase in presence of in vitro caffeine observed with intact microsomes was further investigated in a reconstituted system composed of partially purified cytochrome P-450 and cytochrome c reductase. Caffeine addition (in vitro) to partially purified cytochrome P-450 altered the hexobarbital, aniline and ethylisocyanide induced spectral change, and decreased NADPH oxidation in presence of substrates aminopyrine and acetanilide. NADPH oxidation was found to be increased in presence of aminopyrine and unaltered in presence of acetanilide in reconstituted system having partially purified cytochrome P-450 from caffeine-treated rats. Our studies suggest that caffeine acts as a true modifier of cytochrome P-450 and is possibly responsible for the formation of abortive complexes with aminopyrine.

Alterations in hepatic drug metabolism and lipid peroxidation during administration of Baygon, a pesticide

Biochemical studies during low- and high-dose administration of Baygon (a pesticide) to young male rats were performed. It was observed that the activities of drug-metabolizing enzymes were decreased even at a low dose of Baygon and the decrease was much more significant during high-dose injections. Lipid peroxidation was increased with a low dose and the increase was much more pronounced with a high dose. Besides these changes the animals showed physical changes such as salivation, fasciculations, etc. The presence of conjugated diene absorption patterns and malonaldehyde formation indicated the in vivo lipid peroxidation dut to Baygon administration. Toxic effects leading to death were noted when the animals were injected with a high dose of the pesticide, Baygon above 25 mg/kg.

Hepatic drug hydroxylation and lipid peroxidation in riboflavin-deficient rats

The effect of riboflavin deficiency and phenobarbital pretreatment on drug hydroxylation and lipid peroxidation was investigated. A significant decrease in aniline and acetanilide hydroxylation as well as NADPH-linked and ascorbate-induced lipid peroxidation was observed during 4- and 7-week riboflavin deficiency in both adult male and adult female rats. The drug-hydroxylation and lipid-peroxidation activities were further lowered with the increase in riboflavin deficiency. The phenobarbital pretreatment induced aniline and acetanilide hydroxylase activity even in riboflavin-deficient animals. Drug hydroxylation inhibits lipid peroxidation in both deficient and normal rats. The administration of riboflavin was followed by a significant increase in drug hydroxylation and lipid peroxidation.

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 from(14)C 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 similar(14)C lipid content but a greater(14)C 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 tissue(14)C 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. Less(14)C lipid and(14)C 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.

Effect of ingestion of unsaturated fat on lipolytic activity of rat tissues

Homogenates of some rat tissues, incubated in Tris-maleate buffer containing bovine serum albumin, olive oil emulsion, heparin, and serum, liberated free fatty acids. The total lipolytic activity in tissues of rats fed a low fat, 20% lard, or 20% corn oil diet for 6 wk was measured. Similar activities were found in all the livers, but there was a significant increase in the total lipolytic activity of the mucosa, epididymal fat, and mesenteric tissues after ingestion of an unsaturated fat diet as compared with that containing a more saturated fat. From measurements of the lipolytic activity in the presence of 1 M NaCl or 0.2 M NaF and in the absence and presence of heparin and serum, the conclusion is drawn that more lipoprotein lipase was present in adipose tissue of rats on unsaturated fat diets. An increase in available lipoprotein lipase after unsaturated fat diets may aid in clearing lipids from the blood of these rats and thus in producing the lower blood lipid levels obtained.