The role of functional moieties on carbon nanotube surfaces in solar energy conversion.

An easily dispersible multiwalled carbon nanotube (MWCNT) derivative is prepared, and provides a platform for the synthesis of the phenyl butyric acid methyl ester (PCBM) analog. The carbene addition reaction of MWCNTs makes derivatives that are less soluble in organic solvents; by exploiting this differential solubility, PCBM analogs can be separated from the unreacted functionalized MWCNTs. Our experimental evidences indicate that it is the unique properties of the butyric acid methyl ester moiety that makes the acceptor material perform better in organic photovoltaics (OPVs). Studying the combination of the butyric acid methyl ester moiety and the deagglomerated functionalized MWCNT structures provides us an insight into nanoscale charge transfer and transportation inside the donor-acceptor domain. It is demonstrated that a strong structure-property relationship exists for the functionalized MWCNTs, which enables us to correlate the functionality on the carbon nanostructures with performance in OPVs.

Recurrent hypoglycemia, a rare case of insulin autoimmune syndrome in a young African American male.

Insulin autoimmune syndrome (IAS) is an uncommon cause of spontaneous hypoglycemia from hyperinsulinemia due to autoantibodies against endogenous insulin (Jian-Ping Chu, 2016). These individuals have no prior exposure to exogenous insulin. We report a case of a 35-year-old African American male, who presented to Vaughn Regional Medical Center in Selma, AL, after he was found to have seizures from hypoglycemia, with a blood sugar of 63 on presentation. He was never diagnosed with diabetes in the past, nor did he have a history of seizure disorder. He continued to be hypoglycemic during the initial period of his hospital stay. His fasting insulin level was 27 mIU/l (normal is less than 25, with presence of insulin autoantibodies (IAA), and a negative workup otherwise. This led us to include IAS as one of our differentials for his hypoglycemia.

Iridoid glycoside-based quantitative chromatographic fingerprint analysis: a rational approach for quality assessment of Indian medicinal plant Gambhari (Gmelina arborea).

A sensitive, selective and robust qualitative and quantitative densitometric high-performance thin layer chromatographic method was developed and validated for the determination of iridoid glycoside in the aerial part of Gambhari (Gmelina arborea). Iridoid gycoside 6-O-(2'',3''-dibenzoyl)-alpha-l-rhamnopyranosylcatalpol (IG) was used as a chemical marker for the standardization of G. arborea plant extracts. The separation was performed on aluminum Kieselgel 60F254 TLC plates using chloroform-methanol as mobile phase. The quantitation of IG was carried out using the densitometric reflection/absorption mode at 240 and 430 nm after post-chromatographic derivatization with vanillin-sulphuric acid reagent. A precise and accurate quantification can be performed in the linear working concentration range of 1000-5000 ng/spot with good correlation (r2=0.994). The method was validated for peak purities, precision, robustness, limit of detection (LOD) and quantitation (LOQ), etc., as per ICH guidelines. Specificity of quantitation was confirmed using retention factor (R(f)), UV-vis spectral correlation and ESI-MS spectra of marker compound (IG) in sample track.

Aggressive angiomyxoma of the jejunum: a rare cause of obscure gastrointestinal bleeding.

Obscure gastrointestinal bleeding accounts for nearly 5% of all gastrointestinal haemorrhage and is frequently due to a lesion in the small bowel. We report the case of a male patient with obscure overt gastrointestinal bleed in whom repeated upper gastrointestinal endoscopy, colonoscopy, computed tomography scanning and exploratory laparotomy showed no specific pathology. However, on capsule endoscopy done subsequently, a small polyp in the jejunum was located and resected. Histology revealed an aggressive angiomyxoma. This type of small bowel lesion has not been reported in the literature before.

A comparative study of the 'FDA' and 'USDA' methods for the detection of Listeria monocytogenes in foods.

Nineteen laboratories across Canada took part in a comparative study of the 'FDA' and 'USDA' methods for the detection of Listeria monocytogenes in foods and environmental samples. The results show that the enrichment period of the FDA method can be shortened from 7 to 2 days without substantially reducing the number of positive samples. With a limited number of samples, the USDA method proved to be slightly more efficient in isolating L. monocytogenes than the FDA method. Fraser broth, in principle, proved to be useful as a screening tool but is not very selective. Oxford agar and lithium chloride-phenylethanol-moxalactam medium were better than modified McBride's agar in isolating this microorganism.

Purification and preliminary characterization of L-asparaginase from Erwinia aroideae NRRL B-138.

L-Asparaginase (L-asparagine amidohydrolase EC 3.5.1.1) from Erwinia aroideae NRRL B-138 has been purified to apparent homogeneity by ammonium sulphate precipitation, chromatography on sulfopropyl-sephadex C-50 and sephadex G-200 with 22% recovery and 567-fold purification. The enzyme obtained from sulfopropyl-sephadex C-50 was unstable and lost activity within a few hours. Addition of glycerol helped in restoring the activity of the enzyme. The enzyme has an apparent molecular mass of approximately 155 kDa and has four subunits of identical molecular mass of approximately 38 kDa. The K(m) for L-asparagine is 2.8 x 10(-3) M. Enzyme shows optimal activity at 45 degrees C and pH 8.2. Energy of activation as determined from Arrhenius plot was 9.1 kcal/mol. Substrate L-asparagine and analogue L-glutamine, D-asparagine and 6 diazo-5-oxo-L-norleucine provide full protection to the enzyme against thermal denaturation.

Synthesis of some pyrazoline and isoxazolin derivatives as possible fungicides.

1-Acetyl/aroyl-3-methyl-4-substituted anilido-5-aryl pyrazolines and 3-methyl-4-substituted anilido-5-aryl isoxazolines were conveniently prepared from synthon, 4-aryl-3-substituted anilido but-3-en-2-ones in presence of hydrazine hydrate/hydrazides and hydroxylamine hydrochloride respectively. All the compounds have been assayed against Cephalosporium sacchari and Helminthosporium oryzae and found remarkably active. Two species of aquatic fungi viz. Saprolegnia parasitica and Achlya orion responsible for fish mycoses were tested and also found remarkably active.

Investigations of some aspects of the spray process in a single wire arc plasma spray system using high speed camera.

A high speed camera has been used to record and analyze the evolution as well as particle behavior in a single wire arc plasma spray torch. Commercially available systems (spray watch, DPV 2000, etc.) focus onto a small area in the spray jet. They are not designed for tracking a single particle from the torch to the substrate. Using high speed camera, individual particles were tracked and their velocities were measured at various distances from the spray torch. Particle velocity information at different distances from the nozzle of the torch is very important to decide correct substrate position for the good quality of coating. The analysis of the images has revealed the details of the process of arc attachment to wire, melting of the wire, and detachment of the molten mass from the tip. Images of the wire and the arc have been recorded for different wire feed rates, gas flow rates, and torch powers, to determine compatible wire feed rates. High speed imaging of particle trajectories has been used for particle velocity determination using time of flight method. It was observed that the ripple in the power supply of the torch leads to large variation of instantaneous power fed to the torch. This affects the velocity of the spray particles generated at different times within one cycle of the ripple. It is shown that the velocity of a spray particle depends on the instantaneous torch power at the time of its generation. This correlation was established by experimental evidence in this paper. Once the particles leave the plasma jet, their forward speeds were found to be more or less invariant beyond 40 mm up to 500 mm from the nozzle exit.

Actions of vitamin D are mediated by the TLR4 pathway in inflammation-induced colon cancer.

Many chronic inflammatory diseases are associated with increased risk of developing cancer. In the colon, strong support for a link between chronic inflammation and cancer extends, in part, from population-based studies of persons with inflammatory bowel disease (IBD). Patients with IBD are at increased risk of developing colorectal cancer (CRC). The general consensus is that IBD results from the combined effects of genetics and environment factors known to affect the immune system. Vitamin D, an important regulator of the immune system, has been linked to IBD. Despite the strong potential reported for 1,25-dihydroxyvitamin D (1,25-OH)2D), its effects on calcium metabolism limits its application. Recently, less active vitamin D metabolites, cholecalciferol and 25-hydroxyvitamin D (25(OH)D), have gained considerable attention as promising agents against IBD-related colon cancer. Yet, their anti-proliferative properties and mechanism of action remain to be better defined. We present several signaling pathways commonly regulated by vitamin D compounds and highlight their regulation on TLR4. The efficacy of 25(OH)D and 1alpha-hydroxyviatmin D5 are evaluated using the azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced IBD-related colon carcinogenesis model. In summary, vitamin D supplementation may provide a cost-effective approach to reduce IBD related colon cancer.