178 research outputs found

    Synthesis and Antimicrobial Evaluation of Novel Carbazole Based ÎČ-diketones and its Pyrazole Derivatives

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    Novel 9-ethyl-9H-carbazole-3-carboxylic acid derivatives including ester, ÎČ-diketone and pyrazole were prepared and characterized by FT-IR, 1H NMR, 13C NMR and mass spectroscopic techniques. All synthesized compounds evaluated for their in vitro antimicrobial activities against four bacteria (Escherichia coli, Pseudomonas putide, Bacillus subtilis, and Streptococcus lactis) and three fungi (Aspergillus niger, Penicillium sp and Candida albicans). Among the compounds tested, 3a, 3b, 3c, 4a, 4b, 4c, 5a and 5b exhibited pronounced antibacterial activity as compared with standard drug ampicillin. Notably, carbazole based pyrazole derivatives 5a and 5b showed potent antifungal activity against C. albicans comparable to reference drug greseofulvin. This work is licensed under a Creative Commons Attribution 4.0 International License

    Study of Properties of Al LM-25/SIC fabricated by using Stir Casting Method and Wear Analysis by RSM

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    Aluminum MMC’s are widely used in various applications because of their higher mechanical and physical properties when compared with their base Al alloy. This paper focuses on the change in mechanical properties of various Al/SiC composites fabricated by using stir casting method. Effect of SiC reinforcement in different Al alloys on mechanical properties like hardness, tensile strength, wear test, percentage elongation, residual stress measurements are discussed in detail. For this purpose various reinforcement of SiC with 0,4,8 percent weight and different particle sizes are considered along with Al alloys. Variations in process parameters of stir casting are also made and taken into consideration

    U-shaped type II solar radio bursts associated with the 1980 March 28 flare

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    Observations of the 1980 March 28, 2B flare in optical, radio microwave and metric and X-ray wavelengths are presented. In the dynamic radio spectrum, unusual and rare U-shaped type II radio bursts associated with this flare have been observed. The normal type II bursts display negative frequency drift, due to the flare-triggered shock wave travelling outwards in the solar corona. But in this case the type II emission first showed the usual negative frequency drift, and then after reaching a plateau level, showed a positive drift, thus giving the shape of an inverted "U". The authors propose a model for this type II emission.We suggest that the shock wave generated by the flare or the flare spray propagates through sucting and repeated reflections, which takes place within a large scale coronal loop or an arcade of loops, thus resulting in reverse frequency drift in type II emission

    Modulation of Sn concentration in ZnO nanorod array: intensification on the conductivity and humidity sensing properties

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    Tin (Sn)-doped zinc oxide (ZnO) nanorod arrays (TZO) were synthesized onto aluminum-doped ZnO-coated glass substrate via a facile sonicated sol–gel immersion method for humidity sensor applications. These nanorod arrays were grown at different Sn concentrations ranging from 0.6 to 3 at.%. X-ray diffraction patterns showed that the deposited TZO arrays exhibited a wurtzite structure. The stress/strain condition of the ZnO film metamorphosed from tensile strain/compressive stress to compressive strain/tensile stress when the Sn concentrations increased. Results indicated that 1 at.% Sn doping of TZO, which has the lowest tensile stress of 0.14 GPa, generated the highest conductivity of 1.31 S cm− 1. In addition, 1 at.% Sn doping of TZO possessed superior sensitivity to a humidity of 3.36. These results revealed that the optimum performance of a humidity-sensing device can be obtained mainly by controlling the amount of extrinsic element in a ZnO film

    Toxicity, Tunneling and Feeding Behavior of the Termite, Coptotermes vastator, in Sand Treated with Oil of the Physic Nut, Jatropha curcas

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    Oil of the physic nut, Jatropha curcas L. (Malpighiales: Euphorbiaceae), was evaluated in the laboratory for its barrier and repellent activity against the Philippine milk termite Coptotermes vastator Light (Isoptera: Rhinotermitidae). The study showed that J. curcas oil had anti-feeding effect, induced reduction in tunneling activity and increased mortality in C. vastator. Behavior of termites exposed to sand treated with J. curcas oil indicated that it is toxic or repellent to C. vastator. Toxicity and repellent thresholds, were higher than those reported for other naturally occurring compounds tested against the Formosan subterranean termite

    Seroepidemiology of pandemic influenza A (H1N1) 2009 virus infections in Pune, India

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    <p>Abstract</p> <p>Background</p> <p>In India, Pune was one of the badly affected cities during the influenza A (H1N1) 2009 pandemic. We undertook serosurveys among the risk groups and general population to determine the extent of pandemic influenza A (H1N1) 2009 virus infections.</p> <p>Methods</p> <p>Pre-pandemic sera from the archives, collected during January 2005 to March 2009, were assayed for the determination of baseline seropositivity. Serosurveys were undertaken among the risk groups such as hospital staff, general practitioners, school children and staff and general population between 15<sup>th </sup>August and 11<sup>th </sup>December 2009. In addition, the PCR-confirmed pandemic influenza A (H1N1) 2009 cases and their household contacts were also investigated. Haemagglutination-inhibition (HI) assays were performed using turkey red blood cells employing standard protocols. A titre of ≄1:40 was considered seropositive.</p> <p>Results</p> <p>Only 2 (0.9%) of the 222 pre-pandemic sera were positive. The test-retest reliability of HI assay in 101 sera was 98% for pandemic H1N1, 93.1% for seasonal H1N1 and 94% for seasonal H3N2. The sera from 48 (73.8%) of 65 PCR-confirmed pandemic H1N1 cases in 2009 were positive. Seropositivity among general practitioners increased from 4.9% in August to 9.4% in November and 15.1% in December. Among hospital staff, seropositivity increased from 2.8% in August to 12% in November. Seropositivity among the schools increased from 2% in August to 10.7% in September. The seropositivity among students (25%) was higher than the school staff in September. In a general population survey in October 2009, seropositivity was higher in children (9.1%) than adults (4.3%). The 15-19 years age group showed the highest seropositivity of 20.3%. Seropositivity of seasonal H3N2 (55.3%) and H1N1 (26.4%) was higher than pandemic H1N1 (5.7%) (n = 2328). In households of 74 PCR-confirmed pandemic H1N1 cases, 25.6% contacts were seropositive. Almost 90% pandemic H1N1 infections were asymptomatic or mild. Considering a titre cut off of 1:10, seropositivity was 1.5-3 times as compared to 1:40.</p> <p>Conclusions</p> <p>Pandemic influenza A (H1N1) 2009 virus infection was widespread in all sections of community. However, infection was significantly higher in school children and general practitioners. Hospital staff had the lowest infections suggesting the efficacy of infection-control measures.</p
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