Purification and mechanism of action of antitubercular principle from garlic (Allium sativum) active against isoniazid susceptible and resistantMycobacterium tuberculosis H37Rv

Allicin was prepared from the ethanol extract of garlic without the use of heat. It inhibited the growth ofMycobacterium tuberculosis H₃₇R_v andM. tuberculosis TRC-C 1193 resistant to isoniazid completely when grown as surface cultures as well as shake cultures. The minimum inhibitory concentration (MIC) was 70 μg/ml for both organisms. Further purification of allicin over silica gel-G columns gave a chloroform elutable fraction called CEF-allicin which inhibited the growth of both the susceptible and the isoniazid resistant strains ofM. tuberculosis. Its MIC is 25 μg/ml and is the lowest reported so far when compared with very high inhibitory concentration of 1 to 3mg/ml reported by other workers. It completely inhibited the synthesis of lipids and DNA from¹⁴C-acetate and³H-thymidine respectively and almost completely that of proteins and glycine derived carbohydrates from¹⁴C-glycine ofM. tuberculosis within 6 hr of exposure to CEF-allicin.     

The Nobel Prize in Chemistry 2004

The Nobel Prize in Chemistry for 2004 is shared by Aaron Ciechanover, Avram Hershko and Irwin Rose, who made fundamental discoveries concerning how cells regulate the breakdown of cellular proteins with extreme specificity. The three biochemists discovered ubiquitin-mediated proteolysis, a process where an enzyme system tags unwanted proteins with many molecules of a small protein called ubiquitin and then sends then to the proteasome where they are broken down.     

Circulating thrombotic and haemostatic components in patients with coronary artery disease

The study aimed to analyze the circulating levels of thrombotic and haemostatic components; tissue factor, tissue factor pathway inhibitor, tissue plasminogen activator and plasminogen activator inhibitor-1 in patients with acute myocardial infarction at presentation (Group 1, n=49), unstable angina and Non-ST elevated MI after treatment (Group 2, n=22), stable angina (Group 3, n=18) and healthy individuals (Group 4, n=31). Significant finding was increase in tissue factor not only in Group 1 (2.0 fold, P=0.001), Group 2 (2.2 fold, P=0.015) but also in Group 3 (1.8 fold, P=0.018) as compared to controls. In Group 1 Plasminogen activator inhibitor-1 increased significantly (35.8%, P=0.02). Tissue factor pathway inhibitor and tissue plasminogen activator demonstrated increase in Group 1 of age<40 years while insignificant changes in elder patients. Increased thrombotic and decreased fibrinolytic conditions in acute myocardial infarction patients were observed. Increase TF in stable angina demonstrates procoagulant status in these patients as well.     

Opinion-based entity ranking

The deployment of Web 2.0 technologies has led to rapid growth of various opinions and reviews on the web, such as reviews on products and opinions about people. Such content can be very useful to help people find interesting entities like products, businesses and people based on their individual preferences or tradeoffs. Most existing work on leveraging opinionated content has focused on integrating and summarizing opinions on entities to help users better digest all the opinions. In this paper, we propose a different way of leveraging opinionated content, by directly ranking entities based on a user’s preferences. Our idea is to represent each entity with the text of all the reviews of that entity. Given a user’s keyword query that expresses the desired features of an entity, we can then rank all the candidate entities based on how well opinions on these entities match the user’s preferences. We study several methods for solving this problem, including both standard text retrieval models and some extensions of these models. Experiment results on ranking entities based on opinions in two different domains (hotels and cars) show that the proposed extensions are effective and lead to improvement of ranking accuracy over the standard text retrieval models for this task.     

Unraveling the relationships between smartphone use,exposure to heterogeneity,political efficacy,and political participation: a mediation model approach

This paper assesses how use of smartphones relates to exposure to heterogeneity, political efficacy, and political engagement and suggests a new mediation model that can be applied to mobile communication. Drawing on online survey data collected during the 2012 presidential election in South Korea, this study finds that exposure to heterogeneity and political efficacy jointly mediate the impact of informational uses of smartphones on political participation. The current study also shows that informational uses of smartphones are significantly related to encounters with heterogeneity, political efficacy, and participatory behaviors. Additionally, recreational uses of smartphones were found to have a positive association with exposure to heterogeneity. However, relational uses of smartphones were not associated with democratic outcomes. The findings suggest that smartphones, by increasing the possibility of encountering diversity and subsequently enhancing political efficacy, create an additional pathway to citizen engagement in democratic processes.     

Characterization and synthesis of homogeneous two-variable reactance functions

It is shown in this paper that Homogeneous Two-variable Reactance Polyno- mials (HTRP's) can be expressed as a product of linear factors in the two-variables. Further, a Homogeneous Two-variable Reactance Function (HTRF) can be characterized in terms of the alteration property involving the coefficients of the linear factors of the HTRP in the numerator and denominator. Synthesis procedures for HTRF's are discus- sed; these realizations follow from the single variable RL- or RC-functions associated with a HTRF. Additional properties of HTRF, which will enable us to generate Two- variable Positive Real Functions and Two-variable Reactance Functions are also discussed.     

Partial purification of a hypoglycemic fraction from the unripe fruits ofMomordica charantia Linn (bitter gourd)

A new method was developed to purify partially an orally active hypoglycemic fraction from the unripe fruits ofMomordica charantia Linn. The residue after centrifugation of the fruit juice was extracted with ethanol and the concentrated ethanolic extract was further extracted with diethyl ether. In normal rabbits after oral administration, the ether extract at a dose of 0.75 g/kg body wt decreased the fasting blood glucose by 26% (P<0.01). It was compared with charantin, the isolation procedure of which led to loss of hypoglycemic activity many times. Our new method of isolation is simple and the hypoglycemic effect is retained more consistently after purification.