Bioconvection nanofluid slip flow past a wavy surface with applications in nano-biofuel cells

A theoretical study is presented to examine free convective boundary layer flow of water-based bio-nanofluid containing gyrotactic microorganisms past a wavy surface. Buongiorno’s nanofluid model with passively controlled boundary condition is applied to investigate the effects of the emerging parameters on the physical quantities namely, skin friction, Nusselt numbers and density number of motile microorganisms. The effects of the both hydrodynamic and thermal slips are also incorporated. Local similarity and non-similarity solutions are obtained using the seventh-order Runge-Kutta-Fehlberg method (RKF7) coupled with shooting quadrature. In order to compare our numerical results with the existing data, the active mass flux boundary condition is also used to benchmark MAPLE numerical solutions with earlier similar and non-similar solutions for a smooth stationary surface. It is found that the passive boundary condition reduces the skin friction and enhances local Nusselt numbers. Also the wavy surface is found to result in higher skin friction and higher local Nusselt numbers compared with a stationary surface. It is found that motile micro-organism density number is elevated with increasing bioconvection Péclet number whereas the motile micro-organism species boundary layer thickness is reduced with increasing bioconvection Lewis number. The work finds applications in heat transfer enhancement in bio-inspired nanoparticle-doped fuel cells

Impact of sensitisation programme on screening tests for latent tuberculosis infection among health-care workers: A questionnaire-based study

Background: Timely and accurate identification of people with latent tuberculosis infection (LTBI) is essential for controlling Mycobacterium tuberculosis. Hence, it is important that health-care workers have the latest and adequate knowledge about the existing diagnostic modalities. Methods: In this prospective, questionnaire-based study, various health-care workers were asked to respond to a 25-item questionnaire before the sensitisation programme (workshop) regarding knowledge, procedure and interpretation of screening tests for LTBI (tuberculin skin test [TST] and interferon-gamma release assay [IGRA]). The same questionnaire was repeated on the completion of the workshop to assess its impact. Results: The mean baseline knowledge among technicians, nurses, postgraduates and interns was 42.9%, 42.1%, 51.9% and 53.6%, which improved significantly to 84.2%, 83.4%, 89.4% and 89.5%, respectively after the workshop. Statistically, a significant difference was observed between pre- and post-workshop proprtion of all health-care workers with respect to the knowledge of TST and IGRA (P < 0.05). Conclusions: This questionnaire-based study highlights the importance of training various health-care workers on diagnostic modalities for LTBI since the current study findings revealed that training increased the knowledge scores of the participants significantly

Distinct begomoviruses closely related to cassava mosaic viruses cause Indian Jatropha mosaic disease

A begomovirus was recently shown to be causing Jatropha mosaic disease (JMD) on Jatropha for the first time in India. A typical begomovirus-like symptoms characterized by chlorotic specks on leaves, curling and malformation of leaves, severe reduction in leaf size, partial or complete sterility were seen on infected plants. In Karnataka state, South India, JMD caused significant yield losses by affecting the growth of the infected plant and by disease incidences of up to 47%. The putative Jatropha mosaic India virus (JMIV) was successfully transmitted through grafting, the dodder Cuscuta subinclusa and the whitefly, Bemisia tabaci. The JMIV was detected in infected plants and individual B. tabaci by polymerase chain reaction tests using two sets of begomovirus-specific degenerate primers. The core coat protein (CP) sequences of ~575 bases were obtained from two isolates collected at Bangalore and Dharwad, South India. Phylogenetic analysis of the core CP sequences with those of selected begomoviruses grouped JMIV in a separate cluster close to Indian cassava mosaic virus and Sri Lankan cassava mosaic virus and shared highest nucleotide identities (90-95%) with them. The two JMIV isolates were 94% similar to each other. The begomoviruses causing JMD in the Americas grouped separately from JMIV and shared only 72.8-75.2% core CP nucleotide identities thus they are distinct. These results further confirm that JMD in India was caused by begomoviruses and they were most closely related to cassava mosaic viruses from the Indian sub-continent

Development of silverleaf assay, protein and nucleic acid-based diagnostic techniques for the quick and reliable detection and monitoring of biotype B of the whitefly, Bemisia tabaci (Gennadius)

The aim of this study was to develop and optimize silverleaf bioassay, esterase analysis and PCR-based techniques to distinguish quickly and reliably biotype B of the whitefly, Bemisia tabaci (Gennadius), from Indian indigenous biotypes. Zucchini and squash readily develop silverleaf symptoms upon feeding by the B biotype, but they are not readily available in Indian markets. A local pumpkin variety ‘Big’ was, therefore, used in silverleaf assay, which developed symptoms similar to those on zucchini and squash and can be used reliably to detect B biotype. Analysis of non-specific esterases of B and the indigenous biotypes indicated both quantitative and qualitative differences in esterase patterns. Two high molecular weight bands were unique to B biotype and they occurred in abundance. These esterases were used to develop quick and field-based novel detection methods for differentiating B from the indigenous biotypes. Development of these simple and cost-effective protocols has wider application as they can be potentially used to identify other agricultural pests. Mitochondrial cytochrome oxidase I gene sequences and randomly amplified polymorphic DNA (RAPD) polymorphisms, generated using the primer OpB11, were also found useful for detecting B. tabaci biotypes. A B biotype-specific RAPD band of 800 bp was sequenced, which was used to a develop sequence characterized amplified region (SCAR) marker. The SCAR marker involved the development of B biotype-specific primers that amplified 550 bp PCR products only from B biotype genomic DNA. Silverleaf assay, esterases, RAPDs or a SCAR marker were used in combination to analyse whitefly samples collected from selected locations in India, and it was found that any of these techniques can be used singly or in combination to detect B biotype reliably. The B biotype was found in southern parts of India but not in the north in 2004–06

Tailored Near-Infrared Contrast Agents for Image Guided Surgery

The success of near-infrared (NIR) fluorescence to be employed for intraoperative imaging relies on the ability to develop a highly stable, NIR fluorescent, nontoxic, biocompatible, and highly excreted compound that retains a reactive functionality for conjugation to a cancer-recognizing peptide. Herein, systematic modifications to previously detailed fluorophore ZW800-1 are explored. Specific modifications, including the isosteric replacement of the O atom of ZW800-1, include nucleophilic amine and sulfur species attached to the heptamethine core. These novel compounds have shown similar satisfactory results in biodistribution and clearance while also expressing increased stability in serum. Most importantly, all of the synthesized and evaluated compounds display a reactive functionality (either a free amino group or carboxylic acid moiety) for further bioconjugation. The results obtained from the newly prepared derivatives demonstrate that the central substitution with the studied linking agents retains the ultralow background in vivo performance of the fluorophores regardless of the total net charge