Optimization of 1D Plasmonic Grating of Nanostructured Devices for the Investigation of Plasmonic Bandgap

Plasmonics - The present work investigates the effect of geometrical parameters of 1D nanograting on surface plasmon resonance (SPR) and plasmonic bandgap (PBG). The use of plasmonic grating device...     

Multiple forms of alkaline phosphatase isoenzymes of Serratia marcescens

Alkaline phosphatase (APase) isoenzymes produced by different strains of Serratia marcescens were examined. Variation of isoenzyme patterns with respect to number and their mobilities in starch gels after electrophoresis were observed. Ten strains gave a 1-isoenzyme pattern with 5 different mobilities; 7 strains gave a 2-isoenzyme pattern with 3 different mobilities; 9 strains gave a 3-isoenzyme pattern with 5 different mobilities; and 3 strains gave a 4-isoenzyme pattern. Three strains synthesized two electrophoretically distinct APases in low phosphate medium. A high concentration of inorganic phosphate induced the synthesis of one of these APase isoenzymes.     

Evaluation of biocompatibility and mechanical behavior of chitin-based polyurethane elastomers. Part-II: Effect of diisocyanate structure

Chitin-based polyurethane elastomers having potential for biomedical applications with tunable mechanical properties were synthesized by step growth polymerization techniques using poly(?-caprolactone) (PCL) with different diisocyanates. The prepolymer was extended using chitin and/or 1,4-butane diol (BDO). The structures of the resulted polymers were determined by Fourier transform infrared (FTIR), ¹H NMR and ¹³C NMR spectroscopic techniques. The effect of structure of diisocyanates and chain extenders on mechanical properties and in vitro biocompatibility were investigated. The results revealed that the final polymers extended with chitin are preferred candidates for surgical threads with on going investigations into their in vitro biocompatibility and non-toxicity.     

Butylated hydroxytoluene inclusion in semen extender improves the post-thawed semen quality of Nili-Ravi buffalo (Bubalus bubalis)

The study was carried out to evaluate the potential impact of butylated hydroxytoluene (BHT) on the frozen-thawed semen quality of Nili-Ravi buffalo bulls. Ejaculated bull semen was extended in a Tris-citrate egg yolk extender containing various concentrations of BHT (0.5, 1.0, 2.0 and 3.0 mM). Semen was frozen at −196 °C using 50 × 10⁶ spermatozoa per 0.5 mL straws. Five straws from each treatment were thawed to assess the semen quality in terms of sperm motility, viability, plasma membrane integrity and acrosomal integrity. Post-thawed sperm motility was determined using a phase-contrast microscope. Viability, plasma membrane integrity and acrosomal integrity were evaluated by the supravital staining, hypo-osmotic swelling test and normal acrosomal reaction, respectively. The highest (P < 0.05) motility, acrosomal integrity and hypo-osmotic swelling response of spermatozoa was achieved by addition of 1.0 and 2.0 mM BHT to semen extender. However, highest (P < 0.05) viability of spermatozoa was achieved by inclusion of 2.0 mM BHT. The higher concentration of BHT (3.0 mM) reduced the motility, acrosomal integrity, viability and hypo-osmotic swelling response of the spermatozoa compared to other concentration used. In conclusion, BHT when added in the semen extender can improve the semen quality of buffalo bulls.     

Anti-inflammatory and enzyme inhibitory activities of a crude extract and a pterocarpan isolated from the aerial parts of Vitex agnus-castus

A new compound, 6a,11a-dihydro-6H-[1] benzofuro [3,2-c][1,3]dioxolo[4,5-g]chromen-9-ol was isolated from the ethyl acetate fraction of Vitex agnus-castus. The structure of this compound was identified with the help of spectroscopic techniques ((13)C NMR, (1)H NMR, HMBC, HMQC, NOESY and COSY). The compound showed low urease- (32.0%) and chymotrypsin- (31.4%) inhibitory activity, and moderate (41.3%) anti-inflammatory activity. The crude extract and various fractions obtained from the aerial parts of the plant were also screened for possible in vitro hemagglutination, antibacterial and phytotoxic activities. No hemagglutination activity against human erythrocytes was observed in crude extracts and fractions of V. agnus-castus. The fractions and crude methanolic extract showed moderate and low antibacterial activity. Exceptions were the CHCl(3) fraction, which showed significant antibacterial activity against Klebsiella pneumonia (81% with MIC(50)=2.19 mg/mL), the n-hexane fraction, which exhibited no activity against Salmonella typhi, and the CHCl(3) and aqueous fractions, which showed no activity against Bacillus pumalis. Moderate phytotoxic activity (62.5%) was observed by n-hexane fraction of V. agnus-castus against Lemna minor L at 1000 μg/mL.     

Gut integrity and duodenal enteropathogen burden in undernourished children with environmental enteric dysfunction

Environmental enteric dysfunction (EED) is a subclinical condition of intestinal inflammation, barrier dysfunction and malabsorption associated with growth faltering in children living in poverty. This study explores association of altered duodenal permeability (lactulose, rhamnose and their ratio) with higher burden of enteropathogen in the duodenal aspirate, altered histopathological findings and higher morbidity (diarrhea) that is collectively associated with linear growth faltering in children living in EED endemic setting. In a longitudinal birth cohort, 51 controls (WHZ > 0, HAZ > −1.0) and 63 cases (WHZ< -2.0, refractory to nutritional intervention) were recruited. Anthropometry and morbidity were recorded on monthly bases up to 24 months of age. Dual sugar assay of urine collected after oral administration of lactulose and rhamnose was assessed in 96 children from both the groups. Duodenal histopathology (n = 63) and enteropathogen analysis of aspirate via Taqman array card (n = 60) was assessed in only cases. Giardia was the most frequent pathogen and was associated with raised L:R ratio (p = 0.068). Gastric microscopy was more sensitive than duodenal aspirate in H. pylori detection. Microscopically confirmed H. pylori negatively correlated with HAZ at 24 months (r = −0.313, p = 0.013). Regarding histopathological parameters, goblet cell reduction significantly correlated with decline in dual sugar excretion (p< 0.05). Between cases and controls, there were no significant differences in the median (25^th, 75^th percentile) of urinary concentrations (μg/ml) of lactulose [27.0 (11.50, 59.50) for cases vs. 38.0 (12.0, 61.0) for controls], rhamnose [66.0 (28.0, 178.0) vs. 86.5 (29.5, 190.5)] and L:R ratio [0.47 (0.24, 0.90) vs. 0.51 (0.31, 0.71)] respectively. In multivariable regression model, 31% of variability in HAZ at 24 months of age among cases and controls was explained by final model including dual sugars. In conclusion, enteropathogen burden is associated with altered histopathological features and intestinal permeability. In cases and controls living in settings of endemic enteropathy, intestinal permeability test may predict linear growth. However, for adoption as a screening tool for EED, further validation is required due to its complex intestinal pathophysiology.     

Regulatory effects of S-100 protein and parvalbumin on protein kinases and phosphoprotein phosphatases from brain and skeletal muscle

Summary In the eluted fractions of histone-treated crude extracts separated by Sephadex G-200 filtration, multiple protein kinase (PK) activities, including three from brain and two from skeletal muscle, were augmented by both S-100 protein and parvalbumin on the phosphorylation of endogenous substrates. One additional PK activity suppressed by both S-100 and parvalbumin was also found in muscle. In comparison, phosphoprotein phosphatases (PPase), which were also prepared by the same procedure of initial step of histone-treatment followed by the steps of Bio-Gel P-6DG for brain and DNA-cellulose for muscle, were all activated by S-100 while inhibited by parvalbumin and phosphatidylserine.     

Nickel sorption and speciation in a marine environment

Six sediment samples were collected from the northern Arabian Gulf. Nickel was added to each sediment- seawater suspension and the concentration of total dissolved Ni in the suspensions was monitored for 75 days. The analytical data were used to obtain a linear regression equation relating Ni²⁺ activity in the sediment suspensions to pH. Using this equation and thermodynamic information, the distribution of Ni species in the suspensions was calculated. The major inorganic species, extrapolated to 35 salinity and pH 8.1, were: Ni²⁺ (60.1%), NiCl⁺ (16.9%), NiCl _inf2 ^sup0 (5.0%), NiOH⁺ (0.4%), and NiSO _inf4 ^sup0 (17.5%). An increase in the seawater salinity increased the concentration of total dissolved Ni and Ni chloro-complexes. A decrease in pH of seawater increased total dissolved Ni and decreased NiOH⁺ complex, but the proportion of other species remained unchanged. There was no significant (P < 0.05) effect of Cu, Cd, Pb, Fe, Mn, and Al additions on Ni sorption in the marine sediment suspensions.