Potentiometric Determination of Ionisation Constants of 3,5-Disubstituted Isoxazoles

982-98

Metal Chelates of 3-(o-Hydroxyphenyl)-5-phenylisoxazole with Be(II), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) & Dioxouranium(VI)

722-72

Flue curing of Virginia tobacco by a tube-in-basket (TiB) burner using rice husk as fuel and barn insulation

Virginia tobacco crop is flue-cured by individual farmers in the field. This highly energy-intensive process consumes enormous quantities of firewood with serious ecological implications. A tube-in-basket (TiB) burner, developed recently, makes it possible to use rice husk, a locally available agrowaste, as an alternative energy source. Tobacco curing trials carried out in an instrumented research barn showed that the fuel cost per kilogram of tobacco leaf cured was lower with rice husk as compared to firewood. The fuel utilization efficiency index could be improved by about 30% by insulating the barn roof with husk. Comparison of detailed temperature profiles indicated that, with insulation, heat losses through the roof were virtually eliminated, vertical temperature spreads inside the barn were much narrower, and the daynight cyclic variations, as well as inversion of temperatures, were either totally suppressed or greatly reduced. It is postulated that the more stable temperature profiles contributed to fuel economy and also to the quality of the cured leaf

Effect of sintering temperature on electrical transport properties of La<SUB>0.67</SUB>Ca<SUB>0<SUB>.33</SUB></SUB>B>MnO<SUB>3</SUB>

A systematic investigation of lanthanum-based manganite, La0.67Ca0.33MnO3, has been undertaken with a view to understand the influence of varying crystallite size, in the nanoscale, on various physical properties. The materials were prepared by the sol-gel route by sintering at four different temperatures starting from 800 to 1100 &#176; C, with an interval of 100 &#176;C. After the usual characterization of these materials structurally by XRD, their metal-insulator transition (TP) as well as magnetic transition (TC) temperatures were determined. Surprisingly these materials are found to exhibit two different types of behaviors, viz, while TC is found to decrease from 253 to 219 K, TP is increasing from 145 to 195 K with increasing sintering temperature. A systematic study of electrical conductivity of all four materials was undertaken not only as a function of temperature (80-300 K), but also as a function of magnetic field up to 7 T mainly to understand the detailed conduction mechanism in these materials. On analyzing the data by using several theoretical models, it has been concluded that the metallic (ferromagnetic) part of the resistivity (&#961;) (below TP) fits well with the equation &#961;(T)=&#961;0+&#961;2.5T2.5, indicating the importance of grain/domain boundary effects (&#961;0) and electron-magnon scattering processes (~T2.5). On the other hand, in the high temperature (T&gt;TP) paramagnetic insulating regime, the adiabatic small polaron and VRH models fit well in different temperature regions, thereby indicating that polaron hopping might be responsible for the conduction mechanism

Recurrence of tuberculosis among newly diagnosed sputum positive pulmonary tuberculosis patients treated under the Revised National Tuberculosis Control Programme, India: A multi-centric prospective study

<div><p>Introduction</p><p>There is lack of information on the proportion of new smear—positive pulmonary tuberculosis (PTB) patients treated with a 6-month thrice-weekly regimen under Revised National Tuberculosis Control Programme (RNTCP) who develop recurrent TB after successful treatment outcome.</p><p>Objective</p><p>To estimate TB recurrence among newly diagnosed PTB patients who have successfully completed treatment and to document endogenous reactivation or re-infection. Risk factors for unfavourable outcomes to treatment and TB recurrence were determined.</p><p>Methodology</p><p>Adult (aged ≥ 18 yrs) new smear positive PTB patients initiated on treatment under RNTCP were enrolled from sites in Tamil Nadu, Karnataka, Delhi, Maharashtra, Madhya Pradesh and Kerala. Those declared “treatment success” at the end of treatment were followed up with 2 sputum examinations each at 3, 6 and 12 months after treatment completion. MIRU-VNTR genotyping was done to identify endogenous re-activation or exogenous re-infection at TB recurrence. TB recurrence was expressed as rate per 100 person-years (with 95% confidence interval [95%CI]). Regression models were used to identify the risk factors for unfavourable response to treatment and TB recurrence.</p><p>Results</p><p>Of the1577 new smear positive PTB patients enrolled, 1565 were analysed. The overall cure rate was 77% (1207/1565) and treatment success was 77% (1210 /1565). The cure rate varied from 65% to 86%. There were 158 of 1210 patients who had TB recurrence after treatment success. The pooled TB recurrence estimate was 10.9% [95%CI: 0.2–21.6] and TB recurrence rate per 100 person–years was 12.7 [95% CI: 0.4–25]. TB recurrence per 100 person–years varied from 5.4 to 30.5. Endogenous reactivation was observed in 56 (93%) of 60 patients for whom genotyping was done. Male gender was associated with TB recurrence.</p><p>Conclusion</p><p>A substantial proportion of new smear positive PTB patients successfully treated with 6 –month thrice-weekly regimen have TB recurrence under program settings.</p></div

Risk factors for unfavourable response at the end of treatment in new smear positive pulmonary TB patients [N = 1543].

<p>Risk factors for unfavourable response at the end of treatment in new smear positive pulmonary TB patients [N = 1543].</p

Study sites for the recurrence of TB among the newly diagnosed sputum positive pulmonary TB patients treated under RNTCP in India.

<p>Study sites for the recurrence of TB among the newly diagnosed sputum positive pulmonary TB patients treated under RNTCP in India.</p