PHYTOCHEMICAL ANALYSIS AND EVALUATION OF ANTIMICROBIAL POTENTIAL OF Senna alata LINN LEAVES EXTRACT

Objective:The objective of the present work is to evaluate the presence of phytochemical constituents and antimicrobial activity of different extracts from the leaves of Senna alata Linn.Methods: The serial exhaustive extraction was done with variousof solvents: Aqueous, Chloroforms, Ethanol, Methanol, Acetone, Benzene, Petroleum ether with increasing polarity using soxhlet apparatus. The phytochemical analysis was done by using the standard procedure. Antimicrobial activity was evaluated by disc diffusion method by using leaves extract against various human pathogens.Results: The results revealed that the leaves extracts contain Flavonoids, Terpenoids, Tannins, Phlobatannins, Saponins, Cardiac glycosides, Carbohydrate, Protein and Anthraquinones in major proportion. Aqueous extract was shown to be more effective against all the organisms followed by ethanol, chloroform, methanol, acetone, benzene, petroleum ether extracts. Salmonella typhi (28mm), Bacillus subtilis (28mm) was found to be most sensitive organism followed by Pseudomonas fluorescence (27mm), Escherichia coli (27mm). Conclusions: It can be concluded that the different extracts of Senna alata leaves extract contain a broad spectrum of secondary metabolites and also exhibit antimicrobial activity against all the tested microorganisms. Further phytochemical research is needed to identity the active product of S. alata may serve as leads in the development of new pharmaceuticals

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Interlaboratory comparison of size measurements on nanoparticles using nanoparticle tracking analysis (NTA)

One of the key challenges in the field of nanoparticle (NP) analysis is in producing reliable and reproducible characterisation data for nanomaterials. This study looks at the reproducibility using a relatively new, but rapidly adopted, technique, Nanoparticle Tracking Analysis (NTA) on a range of particle sizes and materials in several different media. It describes the protocol development and presents both the data and analysis of results obtained from 12 laboratories, mostly based in Europe, who are primarily QualityNano members. QualityNano is an EU FP7 funded Research Infrastructure that integrates 28 European analytical and experimental facilities in nanotechnology, medicine and natural sciences with the goal of developing and implementing best practice and quality in all aspects of nanosafety assessment. This study looks at both the development of the protocol and how this leads to highly reproducible results amongst participants. In this study, the parameter being measured is the modal particle size