Enhancement of lipase activity in non-aqueous media upon immobilization on multi-walled carbon nanotubes

<p>Abstract</p> <p>Background</p> <p>Immobilization of biologically active proteins on nanosized surfaces is a key process in bionanofabrication. Carbon nanotubes with their high surface areas, as well as useful electronic, thermal and mechanical properties, constitute important building blocks in the fabrication of novel functional materials.</p> <p>Results</p> <p>Lipases from <it>Candida rugosa </it>(CRL) were found to be adsorbed on the multiwalled carbon nanotubes with very high retention of their biological activity (97%). The immobilized biocatalyst showed 2.2- and 14-fold increases in the initial rates of transesterification activity in nearly anhydrous hexane and water immiscible ionic liquid [Bmim] [PF6] respectively, as compared to the lyophilized powdered enzyme. It is presumed that the interaction with the hydrophobic surface of the nanotubes resulted in conformational changes leading to the 'open lid' structure of CRL. The immobilized enzyme was found to give 64% conversion over 24 h (as opposed to 14% with free enzyme) in the formation of butylbutyrate in nearly anhydrous hexane. Similarly, with ionic liquid [Bmim] [PF6], the immobilized enzyme allowed 71% conversion as compared to 16% with the free enzyme. The immobilized lipase also showed high enantioselectivity as determined by kinetic resolution of (±) 1-phenylethanol in [Bmim] [PF6]. While free CRL gave only 5% conversion after 36 h, the immobilized enzyme resulted in 37% conversion with > 99% enantiomeric excess. TEM studies on the immobilized biocatalyst showed that the enzyme is attached to the multiwalled nanotubes.</p> <p>Conclusion</p> <p>Successful immobilization of enzymes on nanosized carriers could pave the way for reduced reactor volumes required for biotransformations, as well as having a use in the construction of miniaturized biosensensor devices.</p

Firm insoles effectively reduce hemolysis in runners during long distance running - a comparative study

<p>Abstract</p> <p>Background</p> <p>Shock absorbing insoles are effective in reducing the magnitude and rate of loading of peak impact forces generated at foot strike during running, whereas the foot impact force during running has been considered to be an important cause of intravascular hemolysis in long distance runners. Objective of this study was to evaluate the intravascular hemolysis during running and compare the effect of two different types of insoles (Soft and Firm) on hemolysis.</p> <p>Methods</p> <p>Twenty male long and middle distance runners volunteered to participate in this study. We selected two insoles (Soft and Firm) according to their hardness level (SHORE 'A' scale). Participants were randomly assigned to the soft insole (group 1) and firm insole (group 2) group with ten athletes in each group. Each athlete completed one hour of running at the calculated target heart rate (60-70%). Venous blood samples were collected before and immediately after running. We measured unconjucated bilirubin (mg/dl), lactate dehydrogenase (μ/ml), hemoglobin (g/l) and serum ferritin (ng/ml) as indicators of hemolysis.</p> <p>Results</p> <p>Our study revealed a significant increase in the mean values of unconjucated bilirubin (P < 0.05) while running with soft insoles indicating the occurrence of hemolysis in this group of athletes. Graphical analysis revealed an inverse relationship between hardness of insoles and hemolysis for the observed values.</p> <p>Conclusion</p> <p>Our results indicate that intravascular hemolysis occurs in athletes during long distance running and we conclude that addition of firm insoles effectively reduces the amount of hemolysis in runners compared to soft insoles.</p

Role of tissue eosinophils in oral Leukoplakia: A pilot study

Context: Tissue eosinophilia in oral squamous cell carcinoma has been well - recognized. Studies have reported both favorable and unfavorable prognoses associated with tissue eosinophils in oral squamous cell carcinoma. However, the role of eosinophils in the development of tumor is still unclear. Aims: The present study was an attempt to elucidate the potential role of tissue eosinophils in oral leukoplakia, a potentially malignant lesion. Settings and Design: To count eosinophils in tissues of normal subjects and oral leukoplakia cases. To compare tissue eosinophil count (TEC) between normal and oral leukoplakia cases. To compare TEC between dysplastic and non-dysplastic cases of oral leukoplakia and to correlate with degree of epithelial dysplasia. Materials and Methods: A total of 85 cases (59 cases of oral leukoplakia and 26 normal oral tissues) constituted the study material. Tissue eosinophils were counted in 10 different high- power fields. Statistical Analysis Used: Non-parametric tests (Mann-Whitney U-test, Kruskal-Wallis test, Mann-Whitney post hoc analysis and Spearman's correlation statistics).Results: Mean eosinophil count (MEC) in oral leukoplakia cases was significantly more when compared to normal subjects. MEC in dysplastic cases of oral leukoplakia was significantly more when compared to those without epithelial dysplasia (Mann-Whitney U-test). Furthermore, MEC was directly proportional to the degree of epithelial dysplasia (Spearman's correlation statistics). Conclusions: TEC may be used as an adjunct to predict the malignant transformation of dysplastic cases of oral leukoplakia. Eosinophilic infiltration in oral dysplastic cases should prompt a thorough evaluation for invasiveness, especially when features of invasion are absent or suspected in smaller biopsy specimens. Use of TEC as a prognostic indicator demands larger sample size and mandates long-term follow-up

Transverse Colon Volvulus with Chilaiditis Syndrome

Volvulus of transverse colon is a rare cause of large bowel obstruction. To our knowledge only 75 cases have been reported in the world literature and additionally only three cases of transverse colon volvulus with Chilaiditis syndrome have been reported to date. Because of its rarity here we report a case of transverse colon volvulus which was indeed associated with Chilaiditis syndrome. This is probably the fourth case of Chilaiditis syndrome caused by transverse colon volvulus

Identification, characterization, expression profiling, and virus-induced gene silencing of armadillo repeat-containing proteins in tomato suggest their involvement in tomato leaf curl New Delhi virus resistance

Armadillo repeat family is well-characterized in several plant species for their involvement in multiple regulatory processes including growth, development, and stress response. We have previously shown a three-fold higher expression of ARM protein-encoding in tomato cultivar tolerant to tomato leaf curl New Delhi virus (ToLCNDV) compared to susceptible cultivar upon virus infection. This suggests the putative involvement of ARM proteins in defense response against virus infection; however, no comprehensive investigation has been performed to address this inference. In the present study, we have identified a total of 46 ARM-repeat proteins (SlARMs), and 41 U-box-containing proteins (SlPUBs) in tomato. These proteins and their corresponding genes were studied for their physicochemical properties, gene structure, domain architecture, chromosomal localization, phylogeny, and cis-regulatory elements in the upstream promoter region. Expression profiling of candidate genes in response to ToLCNDV infection in contrasting tomato cultivars showed significant upregulation of SlARM18 in the tolerant cultivar. Virus-induced gene silencing of SlARM18 in the tolerant tomato cultivar conferred susceptibility, which suggests the involvement of this gene in resistance mechanism. Further studies are underway to functionally characterize SlARM18 to delineate its precise role in defense mechanism

College students and credit card companies: Implications of attitudes

More knowledge and understanding is needed regarding the mechanisms influencing college student attitudes toward credit card companies and the behavior that students exhibit using credit cards. Prior literature in the area has been sparse. The current article is an attempt to fill the gap in existing literature. Using survey data, we try to find the determinants of college student attitude toward credit card companies and the responsible use of credit cards. Our findings indicate that a strong positive link exists between student attitude toward credit card companies and responsible credit behavior. Two distinct groups of students are identified - one with a positive attitude toward credit card companies and positive credit use behaviors; the other with the opposing attitude and behavior. Reward cards, payment behavior, number of credit cards, modes of acquisition, awareness about credit card policies, purpose for using credit cards, impulsiveness and certain student characteristics are all indicated as variables that help discriminate between the two different student groups. Our findings have implications for both higher education institutions and credit card firms