310 research outputs found

    Review Study on Larvicidal and Mosquito Repellent Activity of Volatile Oils Isolated from Medicinal Plants

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    Mosquito is a vector for serious human diseases like dengue fever, hemaorrhagic dengue fever and chikungunya, .yellow fever, malaria, filaria and encephalitis among these dengue, hemaorrhagic dengue and chikungunya are highly endemic diseases in Southeast Asian and African countries, causing millions of deaths each and every year. Mosquito repellents thus play a major role in preventing man-mosquito contact and there by minimize the chance of infections and its adverse effects. The development of resistance to chemical insecticides, results rebounding vectorial capacity. Synthetic repellents are chemicals which used worldwide for protection against mosquito-borne diseases and it adversely affects the environment by contaminating water, soil and air. There is an urgent need to find alternatives to the synthetic insecticides. Plants are rich source of alternative agents for control of mosquitoes and its vectors. Extracts and isolated compounds from different plant families have been evaluated for their promising larvicidal and mosquito repellent activities. Literature has documented that essential oils and extracts have been traditionally used as effective repellents. The essential oils whose repellent activities have been demonstrated, as well as the importance of the synergistic effects among their components are the main focus of this review study. Essential oils are volatile mixtures of hydrocarbons with a diversity of functional groups, and their repellent activity has been linked to the presence of monoterpenes and sesquiterpenes. The present review study focused the larvicidal potential and mosquito repellent activity of different volatile oils of medicinal plants. From an economical point of view synthetic chemical is still more frequently used as repellents than essential oils; these essential oils have the potential to provide efficient and can be used as a cheap, eco-friendly, safer for humans and the environment and also efficient alternative to the chemical larvicides

    Effect of Water on the Electrochemical Oxidation of Gas-Phase SO2 in a PEM Electrolyzer for H2 Production

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    Water plays a critical role in producing hydrogen from the electrochemical oxidation of SO2 in a proton exchange membrane (PEM) electrolyzer. Not only is water needed to keep the membrane hydrated, but it is also a reactant. One way to supply water is to dissolve SO2 in sulfuric acid and feed that liquid to the anode, but this process results in significant diffusion resistance for the SO2. Alternatively, we have developed a process where SO2 is fed as a gas to the anode compartment and reacts with water crossing the membrane to produce sulfuric acid. There was concern that the diffusion resistance of water through the membrane is as significant as SO2 diffusion through water, thus limiting the benefit of a gas-phase anode feed. We show here that water diffusion through the membrane is not as limiting as liquid-phase SO2 diffusion. Therefore, we can control the cell voltage, the limiting current, and the sulfuric acid concentration by varying the diffusion resistance of the membrane via thickness or temperature. Catalyst loading, however, has a negligible effect on cell performance

    Application of phycoremediation technology in the treatment of wastewater from a leather-processing chemical manufacturing facility

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    Phycoremediation is the use of algae for the removal or biotransformation of pollutants from wastewater. Employing this technology in the treatment of industrial effluents presents an alternative to the current practice of using conventional methods, including physical and chemical methods. In the present study, the effluent from a leather-processing chemical manufacturing facility, situated at Ranipet, Tamil Nadu, India, was treated using the microalga, Chlorella vulgaris, which was isolated from the effluent itself. The objective of this study was to treat the effluent as well as ETP (effluent treatment plant) solid waste by phycoremediation (pilot-scale field study as well as laboratory study) and to analyse the physico-chemical parameters before and after treatment. The results obtained showed that Chlorella  vulgaris exhibited appreciable nutrient scavenging properties under both laboratory and field conditions, although phycoremediation carried out in sunlight (field study) gave better results. Moreover, the growth of Chlorella vulgaris was faster under field conditions.Keywords: Phycoremediation, microalgae, Chlorella vulgaris, effluent, ETP soli

    Chemotaxonomic studies on Tragia involucrata Linn.

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    In the present work a common plant in and around trichy, botanically equated as Tragia involucrata Linn belonging to the family Euphorbiaceae, has been studied from chemotaxonomic point of view. The study explained the identification and characterization of the compounds isolated from this plant. The chloroform extract of T. involucrata L was subjected to FT-IR and GC-MS to identify the compounds present in it. The compounds identified were Ar- Tumerone; 9, 10 Anthracenedione 1,8-dihydroxy-3-methyl; Friedelane-3-one. The therapeutic potentials of the active principles identified were already assessed. Ar-Tumerone was already reported from Curcuma longa L and the antibacterial and wound healing activity of this compound was well established. Chemistry of T. involucrata L reported in this present work can contribute significantly in providing chemical evidence in support of its inclusion in the family Euphorbiaceae and assigning the position to the genus Tragia.© 2009 International Formulae Group. All rights reserved.Keywords: Tragia involucrata, Chemotaxonomic studies, Ar-Tumerone

    Five-year findings of a comparison of ambulatory short course chemotherapy with radical surgery plus chemotherapy for tuberculosis of the spine in Madras

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    A controlled clinical trial was undertaken to compare the efficacy of short course chemotherapy given alone or combined with radical surgery in the treatment of spinal tuberculosis without paraplegia. Patients with active spinal tuberculosis involving the vertebral bodies and without paraplegia were randomly allocated to one of the following three regimens. (a) Rad 6 : Radical anterior resection with bone grafting plus six months of daily isoniazid and rifampicin. (b) Amb 6 : Ambulatory chemotherapy with six months of daily isoniazid and rifampicin, without surgery. (c) Amb 9 : Same as (b) but the duration being nine months. The patients were intensively followed up for five years from the start. At five years, 98% of 86 Amb 9, 91% of 82 Amb 6 and 88% of 82 Rad 6 patients had a favourable status. It is concluded that ambulatory chemotherapy for 6 or 9 months is highly effective in the treatment of spinal tuberculosis. Radical surgery did not enhance the efficacy of the short course regimen

    A STUDY ON USE OF FACEBOOK BY PG STUDENTS OF SELECTED DEPARTMENTS IN SRI RAMAKRISNA COLLEGE OF ARTS AND SCIENCE, COIMBATORE

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    The study on use of face book by students is a paper that represents a evaluation of more than one hundred studies on the social networking website face book. The paper focuses on face book use, which is currently the most researched theme the main studies for each group are presented, with an emphasis on the most influential ones in the field. The focus of this fictional examination is on the commonalities and difference that start from the results. As a result, one could notice that face book is mainly used to keep in touch with other people, but not in a conventional way as uses tend to spy on other users profiles this phenomenon leads to a growing exhibitionism, which is in turn related to individuals personality teats .use of face book is also influenced by peers and experience with the website

    Short-course chemotherapy for tuberculosis of the spine : A comparison between ambulant treatment and radical surgery - a ten year report.

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    We perfomed a randomised, controlled clinical trial to compare ambulant short-course chemotherapy with anterior spinal fusion plus short-course chemotherapy for spinal tuberculosis without paraplegia. Patients with active disease of vertebral bodies were randomly allocated to one of three regimens: a) radical anterior resection with bone grafting plus six months of daily isoniazid plus rifampicin (Rad6); b) ambulant chemotherapy for six months with daily isoniazid plus rifampicin (Amb6); or c) similar to b) but with chemotherapy for nine months (Amb9). Ten years from the onset of treatment, 90% of 78 Rad6, 94% of 78 Amb6 and 99% of 79 Amb9 patients had a favourable status. Ambulant chemotherapy for a period of six months with daily isoniazid plus rifampicin (Amb6) was an effective treatment for spinal tuberculosis except in patients aged less than 15 years with an initial angle of kyphosis of more than 30° whose kyphosis increased substantially

    Radiative Phase Transitions and Casmir Effect Instabilities

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    Molecular quantum electrodynamics leads to photon frequency shifts and thus to changes in condensed matter free energies often called the Casimir effect. Strong quantum electrodynamic coupling between radiation and molecular motions can lead to an instability beyond which one or more photon oscillators undergo a displacement phase transition. The phase boundary of the transition can be located by a Casimir free energy instability.Comment: ReVTeX4 format 1 *.eps figur
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