10 research outputs found

    Nano-mechanical properties of nano-gold/DLC composite thin films

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    Diamond-like-Carbon composite films, with embedded gold nanoparticles, were deposited onto glass substrates by using capacitively coupled plasma chemical vapour deposition (CCP-CVD) technique. The volume fraction of the metal nanoparticles in the films as well as the size of the nanoparticles was varied by varying the percentage of argon in the methane + argon mixture during the deposition. Bonding environments in these films were obtained from Raman and GIXRD. The nanomechanical and nanotribological properties of the Au-DLC nanocomposite films were evaluated. In situ SPM imaging was utilized to depict deformation characteristics developed during the static and dynamic contact events. Influence of metal incorporation on the extent of sp(2)/sp(3) hybridization and thereby on the nanomechanical and nanotribological properties of the DLC films was studied

    Therapeutic immunization with radio-attenuated Leishmania parasites through i.m. route revealed protection against the experimental murine visceral leishmaniasis

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    After our promising results from prophylactic and therapeutic study (i.p. route) with the radio-attenuated Leishmania donovani parasites against experimental murine visceral leishmaniasis, we prompted to check their therapeutic efficacy through i.m route. BALB/c mice were infected with highly virulent L. donovani parasites. After 75 days, mice were treated with gamma (γ)-irradiated parasites. A second therapeutic immunization was given after 15 days of first immunization. The protection against kala-azar was estimated with the reduction of Leishman–Donovan unit from spleen and liver that scored up to 80% and 93%, respectively, while a twofold increase in nitric oxide (NO) and reactive oxygen species (ROS) productions has been observed in the immunized groups of animals. These groups of mice also showed disease regression by skewing Th2 cytokines (IL-10) towards Th1 cytokine (IFN-γ) bias along with the increased generation of NO and ROS, while the infected control group of mice without such treatment surrendered to the disease. Establishment of Th1 ambience in the treated groups has also been supported from the measured antileishmanial antibody IgG subsets (IgG2a and IgG1) with higher anti-soluble Leishmania antigen-specific IgG2a titer. As seen in our previous studies, doses of attenuation by γ-radiation should be taken into serious consideration. Attenuation of parasites at 50 Gy of absorbed dose of gamma rays has not worked well. Thus, therapeutic use of L. donovani parasites radio-attenuated at particular doses can be exploited as a promising vaccine agent. Absence of any adjuvant may increase its acceptability as vaccine candidate further

    Structural and Optical Studies on Sol-gel Composites of Nickel-Doped Nanocrystalline Zinc Oxide/Polyvinylidene Fluoride

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    Nickel-doped nanocrystalline ZnO with three different Ni concentrations was incorporated in polyvinylidene fluoride thin film for obtaining free-standing flexible film by sol-gel technique. The effect of Ni-ZnO loading on the optical and microstructural properties of the Ni-ZnO/polyvinylidene fluoride composite films was studied. X-ray photoelectron spectroscopy and Raman studies were performed to characterize the bonding environment. Fluorine-terminated surface showed a strong F1 s peak located at similar to 695 eV arising out of C-F bonds. Existence of. phase of polyvinylidene fluoride along with the presence of ZnO nanocrystals were indicated by Raman studies. Secondary ion mass spectrometry studies indicated the distribution of Ni-ZnO particles in the polyvinylidene fluoride matrix

    Flexible and free-standing films containing cobalt-doped nanocrystalline zinc oxide dispersed in polyvinylidene fluoride matrix: synthesis and characterization

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    Synthesis of free-standing flexible Co-ZnO/PVDF composite films is realized by sol-gel technique. Modulation of the optical and microstructural properties of the above composite films with Co-doped nanocrystalline ZnO loading in PVDF matrix was studied critically. Uniform dispersion of Co-doped ZnO in PVDF matrix was indicated by SIMS studies. Information on the bonding environment was obtained from X-ray photoelectron spectroscopy and Raman spectroscopy studies. A very strong peak at similar to 695 eV for core level spectra of F1s along with those for C1s, Zn2p and Co2p dominated the XPS spectra of the composite films. Presence of the predominant beta-phase of PVDF along with peaks related to ZnO nanocrystals in the poled sample was observed in the Raman spectra

    Structural and Optical Studies on Sol-gel Composites of Nickel-Doped Nanocrystalline Zinc Oxide/Polyvinylidene Fluoride

    No full text
    Nickel-doped nanocrystalline ZnO with three different Ni concentrations was incorporated in polyvinylidene fluoride thin film for obtaining free-standing flexible film by sol-gel technique. The effect of Ni-ZnO loading on the optical and microstructural properties of the Ni-ZnO/polyvinylidene fluoride composite films was studied. X-ray photoelectron spectroscopy and Raman studies were performed to characterize the bonding environment. Fluorine-terminated surface showed a strong F1 s peak located at similar to 695 eV arising out of C-F bonds. Existence of. phase of polyvinylidene fluoride along with the presence of ZnO nanocrystals were indicated by Raman studies. Secondary ion mass spectrometry studies indicated the distribution of Ni-ZnO particles in the polyvinylidene fluoride matrix
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