126 research outputs found
An intervention to stop smoking among patients suspected of TB - evaluation of an integrated approach
<p>Abstract</p> <p>Background</p> <p>In many low- and middle-income countries, where tobacco use is common, tuberculosis is also a major problem. Tobacco use increases the risk of developing tuberculosis, secondary mortality, poor treatment compliance and relapses. In countries with TB epidemic, even a modest relative risk leads to a significant attributable risk. Treating tobacco dependence, therefore, is likely to have benefits for controlling tuberculosis in addition to reducing the non-communicable disease burden associated with smoking. In poorly resourced health systems which face a dual burden of disease secondary to tuberculosis and tobacco, an integrated approach to tackle tobacco dependence in TB control could be economically desirable. During TB screening, health professionals come across large numbers of patients with respiratory symptoms, a significant proportion of which are likely to be tobacco users. These clinical encounters, considered to be "teachable moments", provide a window of opportunity to offer treatment for tobacco dependence.</p> <p>Methods/Design</p> <p>We aim to develop and trial a complex intervention to reduce tobacco dependence among TB suspects based on the WHO 'five steps to quit' model. This model relies on assessing personal motivation to quit tobacco use and uses it as the basis for assessing suitability for the different therapeutic options for tobacco dependence.</p> <p>We will use the Medical Research Council framework approach for evaluating complex interventions to: (a) design an evidence-based treatment package (likely to consist of training materials for health professionals and education tools for patients); (b) pilot the package to determine the delivery modalities in TB programme (c) assess the incremental cost-effectiveness of the package compared to usual care using a cluster RCT design; (d) to determine barriers and drivers to the provision of treatment of tobacco dependence within TB programmes; and (e) support long term implementation. The main outcomes to assess the effectiveness would be point abstinence at 4 weeks and continuous abstinence up to 6 months.</p> <p>Discussion</p> <p>This work will be carried out in Pakistan and is expected to have relevance for other low and middle income countries with high tobacco use and TB incidence. This will enhance our knowledge of the cost-effectiveness of treating tobacco dependence in patients suspected of TB.</p> <p>Trial Registration</p> <p>Trial Registration Number: ISRCTN08829879</p
Design and validation of a fixture for positive incremental sheet forming
Incremental sheet forming is an emerging manufacturing technique in which sheet metal is formed into desired shape through the application of localized force using a hemispherical tool. Potential advantages of the process are its relatively low cost and small lead times, and these have to be balanced against the disadvantages of low dimensional accuracy and a limited understanding of the process’ internal mechanics. Incremental sheet forming system can be classified as positive, or negative, depending on whether the sheet material is progressively deformed onto a protrusion or a cavity. In negative systems, the work piece is held on a static fixture; whereas, in positive incremental sheet forming, the fixture must be incrementally lowered onto a protruding die. Although the vertical movement of positive incremental sheet forming fixtures is easily illustrated schematically, its implementation is challenging; if the descent is actuated, the motion has to be carefully coordinated with those of the forming tool; if free sliding on vertical columns, the rig must move without jamming or rocking. This article reports the development and testing of a positive incremental sheet forming fixture design that uses nylon sleeve bushes. Symmetric and asymmetric components were formed using the designed fixture, modular wooden dies and a rotating tool with multiple diameters and the results are discussed
Adventitious root formation in branch cuttings of Taxus wallichiana Zucc.(Himalayan yew): A clonal approach to conserve the scarce resource
Himalayan yew (Taxus wallichiana Zucc.), is an economically valuable plant and critically endangered due to overexploitation for the isolation of Taxol,an exciting anticancer drug from its bark and leaves. Since the species is unisexual and due to its long seed dormancy period and rapid loss of viability coupled with low survival percentage, its natural regeneration from seeds is very poor. As the seed raised plants add little growth, propagation by stem cuttings was tried under natural conditions and a considerable success was achieved after making use of different auxins (Indole-3- Acetic Acid-IAA, Indole Butyric Acid-IBA and Naphthalene Acetic Acid-NAA) in different concentrations. A Randomized block design (RBD) was adopted for laying the experiment of the present study. Of the ten treatments studied, IBA at 500ppm performed best of all the treatments and registered higher callusing percentage, rooting percentage, number of roots and length of roots in the juvenile shoot cuttings of the species. The results achieved through the application ofplant growth regulators (PGRs)by way of adventitious root formation (ARF) could be useful for the management of this understory coniferous tree species, whether for conservation, habitat restoration or for the production of Taxol,a promising anti-cancer agent. The technique evolved will be the most handy, quickest, inexpensive and can be applied any where in its natural habitat for the restoration and restocking of this valuable plant, which is otherwise facing the peril of extinction throughout the range of its distribution including Indian Himalayas
Synthesis and antibacterial study of some s-substituted aliphatic analogues of 2-mercapto-5-(1-(4-toluenesulfonyl) piperidin-4-yl)-1,3,4-oxadiazole
Purpose: To synthesize a series of analogues of 1,3,4-oxadiazole and to evaluate their antibacterial activity.Methods: Ethyl piperidin-4-carboxylate (1) was mixed with 4-toluenesulfonyl chloride (2) in benignant conditions to yield ethyl 1-(4-toluenesulfonyl)piperidin-4-carboxylate (3) and then 1-(4- toluenesulfonyl)piperidin-4-carbohydrazide (4). Intermolecular cyclization of 4 into 2-mercapto-5-(1-(4- toluenesulfonyl) piperidin-4-yl)-1,3,4-oxadiazole (5) was obtained on reflux with CS2 in the presence of KOH. Molecule 5 was stirred with alkyl halides, 6a-i, in DMF in the presence of LiH to synthesize the final compounds, 7a-i. The structures of these molecules were elucidated by Fourier transform infra-red (FTIR) spectroscopy, proton nuclear magnetic resonance (1H-NMR) and electron impact mass spectrometry (EI-MS). Antibacterial activity was evaluated against five bacterial strains, namely, Salmonella typhi, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis, with ciprofloxacin used as standard antibacterial agent.Results: Out of nine synthesized derivatives, compound 7a was the most active against three bacterial strains, S. typhi, E. coli and P. aeruginosa, with minimum inhibitory concentration (MIC) of 9.11 ± 0.40, 9.89 ± 0.45 and 9.14 ± 0.72 μM, respectively, compared with 7.45 ± 0.58, 7.16 ± 0.58 and 7.14 ± 0.18 μM, respectively, for the reference standard (ciprofloxacin). Similarly, compounds 7a - 7c showed relatively good antibacterial activity against B. subtilis strain while compound 7e - 7g revealed good results against S. typhi bacterial strain.Conclusion: The results indicate that S-substituted derivatives of the parent compound are more effective antibacterial agents than the parent compound, even with minor differences in substituents.Keywords: 1,3,4-Oxadiazole, Antibacterial activity, Ethyl piperidin-4-carboxylate, Sulfonamid
Thermal analysis of proposed heat sink design under natural convection for the thermal management of electronics
The rapid development in the field of electronics has led to high power densities and miniaturization of electronic packages. Because of the compact size of electronic devices, the rate of heat dissipation has increased drastically. Due to this reason, the air-cooling system with a conventional heat sink is insufficient to remove large quantity of heat. A novel macro-channel ?L-shaped heat sink? is pro-posed and analyzed to overcome this problem. The thermal resistance and fluid-flow behavior under natural convection, of the novel and conventional air-cooled heat sink designs, are analyzed. Governing equations are discretized and solved across the computational domain of the heat sink, with 3-D conjugate heat transfer model. Numerical results are validated through experimentation. The effect of parameters i.e., fin height, number of fins and heat sink size, on the thermal resistance and fluid-flow are reported. Examination of these parameters provide a better physical understanding from energy conservation and management view point. Substantial increase in the thermal performance is noted for the novel ?L-shaped heat sink? compared to the conventional design
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