Quality of symptom elicitation in an epidemiological survey on tuberculosis

The quality of symptom elicited by health workers in an epidemiological survey on tuberculosis was assessed by again subjecting a 10% random sample of the persons interviewed, by the supervisory staff, independently. Three thousand four hundred and forty nine persons were thus interviewed twice. The overall estimates for overdiagnosis and under-diagnosis in the elicitation of symptoms by health workers were to the extent of 16% and 8% respectively, with minimal yield of sputum positivity from the discordant groups of persons. The additional load of 16% for sputum examination can thus be considerably reduced if health workers are well trained in symptom-elicitationscreening of the population and their work is monitored through spot supervisory checks

Crystal structure of ethyl (2S,2′ R)-1′-benzyl-3-oxo-3H-dispiro[1-benzothio-phene-2,3′-pyrrolidine-2′,11″-indeno-[1,2-b]quinoxaline]-4′-carboxylate

The authors thank the TBI X-ray facility, CAS in Crystallography and BioPhysics, University of Madras, Chennai, India, for the data collection.Peer reviewedPublisher PD

Local density of states and scanning tunneling currents in graphene

We present exact analytical calculations of scanning tunneling currents in locally disordered graphene using a multimode description of the microscope tip. Analytical expressions for the local density of states (LDOS) are given for energies beyond the Dirac cone approximation. We show that the LDOS at the $A$ and $B$ sublattices of graphene are out of phase by $\pi$ implying that the averaged LDOS, as one moves away from the impurity, shows no trace of the $2q_F$ (with $q_F$ the Fermi momentum) Friedel modulation. This means that a STM experiment lacking atomic resolution at the sublattice level will not be able of detecting the presence of the Friedel oscillations [this seems to be the case in the experiments reported in Phys. Rev. Lett. {\bf 101}, 206802 (2008)]. The momentum maps of the LDOS for different types of impurities are given. In the case of the vacancy, $2q_F$ features are seen in these maps. In all momentum space maps, $K$ and $K+K^\prime$ features are seen. The $K+K^\prime$ features are different from what is seen around zero momentum. An interpretation for these features is given. The calculations reported here are valid for chemical substitution impurities, such as boron and nitrogen atoms, as well as for vacancies. It is shown that the density of states close to the impurity is very sensitive to type of disorder: diagonal, non-diagonal, or vacancies. In the case of weakly coupled (to the carbon atoms) impurities, the local density of states presents strong resonances at finite energies, which leads to steps in the scanning tunneling currents and to suppression of the Fano factor.Comment: 21 pages. Figures 6 and 7 are correctly displayed in this new versio

Carbon Nanotubes by a CVD Method. Part II: Formation of Nanotubes from (Mg, Fe)O Catalysts

The aim of this paper is to study the formation of carbon nanotubes (CNTs) from different Fe/MgO oxide powders that were prepared by combustion synthesis and characterized in detail in a companion paper. Depending on the synthesis conditions, several iron species are present in the starting oxides including Fe2+ ions, octahedral Fe3+ ions, Fe3+ clusters, and MgFe2O4-like nanoparticles. Upon reduction during heating at 5 °C/min up to 1000 °C in H2/CH4 of the oxide powders, the octahedral Fe3+ ions tend to form Fe2+ ions, which are not likely to be reduced to metallic iron whereas the MgFe2O4-like particles are directly reduced to metallic iron. The reduced phases are R-Fe, Fe3C, and ç-Fe-C. Fe3C appears as the postreaction phase involved in the formation of carbon filaments (CNTs and thick carbon nanofibers). Thick carbon nanofibers are formed from catalyst particles originating from poorly dispersed species (Fe3+ clusters and MgFe2O4-like particles). The nanofiber outer diameter is determined by the particle size. The reduction of the iron ions and clusters that are well dispersed in the MgO lattice leads to small catalytic particles (<5 nm), which tend to form SWNTS and DWNTs with an inner diameter close to 2 nm. Well-dispersed MgFe2O4-like particles can also be reduced to small metal particles with a narrow size distribution, producing SWNTs and DWNTs. The present results will help in tailoring oxide precursors for the controlled formation of CNTs

Carbon Nanotubes by a CVD Method. Part I: Synthesis and Characterization of the (Mg, Fe)O Catalysts

The controlled synthesis of carbon nanotubes by chemical vapor deposition requires tailored and wellcharacterized catalyst materials. We attempted to synthesize Mg1-xFexO oxide solid solutions by the combustion route, with the aim of performing a detailed investigation of the influence of the synthesis conditions (nitrate/urea ratio and the iron content) on the valency and distribution of the iron ions and phases. Notably, characterization of the catalyst materials is performed using 57Fe Mo¨ssbauer spectroscopy, X-ray diffraction, and electron microscopy. Several iron species are detected including Fe2+ ions substituting for Mg2+ in the MgO lattice, Fe3+ ions dispersed in the octahedral sites of MgO, different clusters of Fe3+ ions, and MgFe2O4-like nanoparticles. The dispersion of these species and the microstructure of the oxides are discussed. Powders markedly different from one another that may serve as model systems for further study are identified. The formation of carbon nanotubes upon reduction in a H2/CH4 gas atmosphere of the selected powders is reported in a companion paper

Maternal periodontitis and its influence on duration of gestation and fetal birth weight

Background: There has been a lot of interest in knowing the effects of oral health on adverse pregnancy outcomes like preterm births and low birth weight. Studies have yielded contradicting results and there are lot of confounding issues that blur the picture.  Aim of the study is to determine the prevalence of periodontitis is pregnant population and determine the effect of periodontitis on preterm births and low birth weight.Methods: This was a cross sectional study of singleton pregnant women attending ante-natal checkups with oral interview and clinical examination. Oral examination was done at the beginning of third trimester of pregnancy. They were followed up to delivery to note the duration of gestation, birth weight of babies.Results: The prevalence of periodontitis was 22% with 90.9% having mild and 9.1% having moderate periodontitis. Maternal education (high school and above) was associated with lower prevalence of periodontitis (p=0.042). There was no difference in the birth weights between the group with and without periodontitis (2.9±0.41kgs vs 2.74±0.36kgs, p=0.11). The incidence of low birth weights was also similar (p=0.22). The average gestational age was slightly less in the group with periodontitis (38 weeks 3 days vs 37 weeks 5 days) but the rates of preterm births were similar between the two groups (p=0.61).Conclusions: Mild/moderate periodontitis does not appear to have a significant effect on pre-term births and low birth weight. Maternal education and awareness seem to mitigate development of periodontitis and adverse pregnancy outcomes

Crop Protection to Outsmart Climate Change for Food Security & Environmental Conservation

Pearl millet is an important source of energy and nutrition for millions of people in the drylands of sub-Saharan Africa and South Asia. Recently, blast, also known as leaf spot, caused by Magnaporthe grisea (Anamorph: Pyricularia grisea) has emerged as a serious threat to pearl millet cultivation causing substantial yield loss. Seeds tend to contain several storage proteins, some have an inhibitory action against plant pathogens. The present study aimed to identify the defense proteins in seed extrudes of ten pearl millet blast differential lines and investigate their protective effect against growth of Pyricularia grisea (Pg 45, Patancheru isolate). The biochemical observations of seed extrudes revealed the presence of plant defense linked hydrolytic enzymes chitinases (12-18 units/ml), β-1,3 glucanases (16-48 units/mg protein) as well as cysteine protease inhibitors (57-123 PI units/mg protein) among the tested lines. The pre-treatment of P. grisea media with respective line seed extrudes resulted in significant reduction (22-40%; p<0.001) of fungal radial growth and fungal dry weight (20-77%; p<0.001). The effective concentration for the 50% fungal growth inhibition (EC50) was identified as 400 and 600 μg/ml for resistant lines IP 21187 and ICMR 06444, respectively. Further, the seed extrudes were able to significantly retard the spore germination (by 18 h) and initial growth (by 48 h) of Pg 45 by 24-83%. These findings suggest that the identified proteins are playing synergistic role in pearl millet defense against blast pathogen, Pg 45 and provide the basis to explore the novel biological control strategies in plant defense

Synthesis and biological evaluation of novel 2-phenylquinazoline-4-amine derivatives:identification of 6-phenyl-8H-benzo[g]quinazolino[4,3-b]quinazolin-8-one as a highly potent inducer of NAD(P)H quinone oxidoreductase 1

A novel series of quinazoline compounds (2-14) incorporating biologically active heterocyclic moieties were designed and synthesized. The structure of the newly synthesized compounds was recognized on the basis of elemental analyses, IR, (1)H-NMR, (13)C-NMR and mass spectral data. All compounds were evaluated for their ability to induce the cytoprotective enzyme NAD(P)H:quinone oxidoreductase 1 (NQO1) using a quantitative bioassay and a docking study was performed in the Kelch domain of Keap1 obtained from the Protein Data Bank (PDB ID: 4IQK) to explore the ability of the synthesized compounds to block the Nrf2-binding site of Keap1. All of the synthesized compounds showed concentration-dependent inducer activity with potencies in the low- or sub-micromolar range. Compound 12 was the most potent inducer in this new series, with a concentration that doubles the specific activity of NQO1 (CD value) of 70 nM. The identification of this compound offers a new chemical scaffold for future development of highly potent inducers.</p