Comparison of dosimetric characteristics of physical and enhanced dynamic wedges

BackgroundWedge filters can be used as missing tissue compensators or wedge pairs to alter the shape of isodose curves so that two beams can be angled with a small hinge angle at a target volume without creating a hotspot.AimIn this study the dosimetric properties of Varian Enhanced Dynamic Wedge (EDW) and physical wedges (PW) were analyzed and compared.Materials and methodsIonometric measurements of open field output factor, physical wedge output factor, physical wedge factor and EDW factor for photon beams were carried out. A 3D scanning water phantom was used to scan depth dose and profiles for open and PW fields. The 2D ionization matrix was used to measure profiles of physical and EDW wedges. The isodose curves of physical and EDW angles were obtained using a therapy verification film.Results and discussionThe PW output factors of photons were compared with the open field output factors. The physical and EDW factors were compared. The difference in percentage depth dose for open and PW fields was observed for both photon beams. The measured isodose plots for physical and EDW were compared.ConclusionThe wedge field output factor increases with field size and wedge angle compared to that of the open field output factor. The number of MU to deliver a particular dose with the EDW field is less than that of the PW field due to a change in wedge factor. The dosimetric characteristics, like profile and isodose of EDW, closely match with that of the PW.     

Phagodeterrence and insecticidal activity of Hyptis suaveolens (Poit.) against four important lepidopteran pests

This study was carried out to evaluate the antifeedant and larvicidal activities of Hyptis suaveolens Poit. (Lamiaceae) leaves crude extracts and their fractions against four lepidopteran pests namely Helicoverpa armigera (Hbn.), Spodoptera litura (Fab.), Earias vittella (Fab.) and Leucinodes orbonalis (G.). Hexane, chloroform and ethyl acetate extracts were tested by leaf disc and fruit disc no-choice methods at 1% and 1,000?ppm concentrations for crude and fractions, respectively. Ethyl acetate extract of H. suaveolens exhibited the maximum antifeedant and insecticidal activity at 1% concentration against all the tested insects. It was subjected to fractionation using silica column chromatography with different combinations of hexane and ethyl acetate used as mobile phase. Among the 15 fractions obtained, fraction 2 showed the maximum antifeedant and insecticidal activity against all tested insects at 1000?ppm concentration. Preliminary phytochemical analysis of fraction 2 showed the presence of terpenoids and alkaloids. H. suaveolens could be considered as a safe and eco-friendly insecticide for lepidopteron pest management.     

Dry-reagent gold nanoparticle-based lateral flow biosensor for the simultaneous detection of Vibrio cholerae serogroups O1 and O139

Cholera is a communicable disease caused by consumption of contaminated food and water. This potentially fatal intestinal infection is characterised by profuse secretion of rice watery stool that can rapidly lead to severe dehydration and shock, thus requiring treatment to be given immediately. Epidemic and pandemic cholera are exclusively associated with Vibrio cholerae serogroups O1 and O139. In light of the need for rapid diagnosis of cholera and to prevent spread of outbreaks, we have developed and evaluated a direct one-step lateral flow biosensor for the simultaneous detection of both V. cholerae O1 and O139 serogroups using alkaline peptone water culture. Serogroup specific monoclonal antibodies raised against lipopolysaccharides (LPS) were used to functionalize the colloidal gold nanoparticles for dual detection in the biosensor. The assay is based on immunochromatographic principle where antigen-antibody reaction would result in the accumulation of gold nanoparticles and thus, the appearance of a red line on the strip. The dry-reagent dipstick format of the biosensor ensure user-friendly application, rapid result that can be read with the naked eyes and cold-chain free storage that is well-suited to be performed at resource-limited settings.     

Profiling of biodegradation and bacterial 16S rRNA genes in diverse contaminated ecosystems using 60-mer oligonucleotide microarray

We have developed an oligonucleotide microarray for the detection of biodegradative genes and bacterial diversity and tested it in five contaminated ecosystems. The array has 60-mer oligonucleotide probes comprising 14,327 unique probes derived from 1,057 biodegradative genes and 880 probes representing 110 phylogenetic genes from diverse bacterial communities, and we named it as BiodegPhyloChip. The biodegradative genes are involved in the transformation of 133 chemical pollutants. Validation of the microarray for its sensitivity specificity and quantitation were performed using DNA isolated from well-characterized mixed bacterial cultures also having non-target strains, pure degrader strains, and environmental DNA. Application of the developed array using DNA extracted from five different contaminated sites led to the detection of 186 genes, including 26 genes unique to the individual sites. Hybridization of 16S rRNA probes revealed the presence of bacteria similar to well-characterized genera involved in biodegradation of various pollutants. Genes involved in complete degradation pathways for hexachlorocyclohexane (lin), 1,2,4-trichlorobenzene (tcb), naphthalene (nah), phenol (mph), biphenyl (bph), benzene (ben), toluene (tbm), xylene (xyl), phthalate (pht), Salicylate (sal), and resistance to mercury (mer) were detected with highest intensity. The most abundant genes belonged to the enzyme hydroxylases, monooxygenases, and dehydrogenases which were present in all the five samples. Thus, the array developed and validated here shall be useful in assessing not only the biodegradative potential but also the composition of environmentally useful bacteria, simultaneously, from hazardous ecosystems.     

A new species of Beilschmiedia (Lauraceae) from the Western Ghats,India

Beilschmiedia tirunelvelica is described and illustrated as a new species from the Western Ghats of Agasthiyamalai Biosphere Reserve, India. The differences to similar taxa are provided with dichotomous key and table.     

Optimized in vitro micro-tuber production for colchicine biosynthesis in Gloriosa superba L. and its anti-microbial activity against Candida albicans

Plant Cell, Tissue and Organ Culture (PCTOC) - Gloriosa superba L. tubers are a rich source of commercially important colchicine and due to overexploitation, the species has become vulnerable. In...     

Gelsemiaceae (Gentianales) expanded to include the enigmatic Asian genus Pteleocarpa

The enigmatic South‐East Asian monotypic genus Pteleocarpa has been considered as a genus incertae sedis among the eudicots for a long time. Molecular data (plastid and nuclear ribosomal regions) from 44 widely sampled species across Lamiidae and phylogenetic analyses have finally clarified its familial relationships, and it is here included in Gelsemiaceae (order Gentianales). Its morphological characteristics support a placement in this family and order as a result of the presence of potential synapomorphies, such as imbricate and commonly yellow corollas, latrorse anther dehiscence, divided styles and compressed seeds. Unique characters for Pteleocarpa in Gelsemiaceae are alternate leaves and indehiscent samaras. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175 , 482–496.     

Bacillus mesophilum sp. nov., strain IITR-54T,a novel 4-chlorobiphenyl dechlorinating bacterium

The taxonomic position of a Gram-positive, endospore-forming bacterium isolated from soil sample collected from an industrial site was analyzed by a polyphasic approach. The strain designated as IITR-54^T matched most of the phenotypic and chemical characteristics of the genus Bacillus and represents a novel species. It was found to biodegrade 4-chlorobiphenyl through dechlorination and was isolated through enrichment procedure from an aged polychlorinated biphenyl-contaminated soil. Both resting cell assay and growth under aerobic liquid conditions using 4-chlorobiphenyl as sole source of carbon along with 0.01 % yeast extract, formation of chloride ions was measured. 16S rRNA (1,489 bases) nucleotide sequence of isolated strain was compared with those of closely related Bacillus type strains and confirmed that the strain belongs to the genus Bacillus. Strain IITR-54^T differs from all other species of Bacillus by at least 2.1 % at the 16S rRNA level, and the moderately related species are Bacillus oceanisediminis (97.9 %) followed by Bacillus infantis (97.7 %), Bacillus firmus (97.4 %), Bacillus drentensis (97.3 %), Bacillus circulans (97.2 %), Bacillus soli (97.1 %), Bacillus horneckiae (97.1 %), Bacillus pocheonensis (97.1 %) and Bacillus bataviensis (97.1 %), respectively. The cell wall peptidoglycan contained meso-diaminopimelic acid and the major isoprenoid quinone was MK-7. Major fatty acids are iso-C_15:0 (32.4 %) and anteiso-C_15:0 (27.4 %). Predominant polar lipids are diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The results of physiological and biochemical tests allowed the genotypic and phenotypic distinctiveness of strain IITR-54^T with its phylogenetic relatives and suggest that the strain IITR-54^T should be recognized as a novel species, for which the name Bacillus mesophilum sp. nov. is proposed. The type strain is IITR-54^T (= MTCC 11060^T = JCM 19208^T).     

PPS: A computing engine to find Palindromes in all Protein sequences

The primary structure of a protein molecule comprises a linear chain of amino acid residues. Certain parts of this linear chain are unique in nature and function. They can be classified under different categories and their roles studied in detail. Two such unique categories are the palindromic sequences and the Single Amino Acid Repeats (SAARs), which plays a major role in the structure, function and evolution of the protein molecule. In spite of their presence in various protein sequences, palindromes have not yet been investigated in detail. Thus, to enable a comprehensive understanding of these sequences, a computing engine, PPS, has been developed. The users can search the occurrences of palindromes and SAARs in all the protein sequences available in various databases and can view the three-dimensional structures (in case it is available in the known three-dimensional protein structures deposited to the Protein Data Bank) using the graphics plug-in Jmol. The proposed server is the first of its kind and can be freely accessed through the World Wide Web.

Availability

URL http://pranag.physics.iisc.ernet.in/pps/