7,093 research outputs found
Tuberculosis vaccine: pipeline approaches and future prospective
Tuberculosis (TB), despite anti-mycobacterial therapies and vaccine, is a deadly infectious disease with about 12 million incident cases worldwide. Existing Bacillus Calmette-Guérin (BCG) vaccine is unquestionably inexpensive, safe and effective against severe forms of childhood TB but appears to be limited in effectiveness against adult pulmonary disease in endemic areas. Genetic variation in the population is the major obstruction inhibiting validation of biomarkers for protective human immunity against TB. Since current TB cases are presenting new challenges with threats of HIV co-infection therefore various attempts at a global platform are being made to develop a new modified vaccine against it. Consequently, Modified Vaccinia Ankara virus (MVA) vectored MPT64 & Ag85A delivery and polyvalent DNA vaccine, expressing an ESAT6–Ag85B fusion protein etc. are preclinically tested for boosted immune effects. However, better vaccine approaches still need to be developed against M. tuberculosis which can be unbeaten in most infected areas
Accelerating dark energy models in bianchi Type-V space-time
Some new exact solutions of Einstein's field equations in a spatially
homogeneous and anisotropic Bianchi type-V space-time with minimally
interaction of perfect fluid and dark energy components have been obtained. To
prevail the deterministic solution we choose the scale factor , which yields a time dependent deceleration parameter (DP),
representing a model which generates a transition of the universe from the
early decelerating phase to the recent accelerating phase. We find that for , the quintessence model is reproducible with present and expected
future evolution of the universe. The other models (for ), we observe
the phantom scenario. The quintessence as well as phantom models approach to
isotropy at late time. For different values of , we can generate a class of
physically viable DE models. The cosmic jerk parameter in our descended model
is also found to be in good concordance with the recent data of astrophysical
observations under appropriate condition. The physical and geometric properties
of spatially homogeneous and anisotropic cosmological models are discussed.Comment: 12 pages, 6 figure
Thermoelectric response of FeTeSe: evidence for strong correlation and low carrier density
We present a study of the Seebeck and Nernst coefficients of
FeTeSe extended up to 28 T. The large magnitude of the
Seebeck coefficient in the optimally doped sample tracks a remarkably low
normalized Fermi temperature, which, like other correlated superconductors, is
only one order of magnitude larger than T. We combine our data with other
experimentally measured coefficients of the system to extract a set of
self-consistent parameters, which identify FeTeSe as a
low-density correlated superconductor barely in the clean limit. The system is
subject to strong superconducting fluctuations with a sizeable vortex Nernst
signal in a wide temperature window.Comment: 4 pages including 4 figure
Kinetics of Reaction between Iodine & o-Chloromercuriphenol in Methanol, Ethanol, n-Propanol, Isopropanol, n-Butanol & n-Pentanol
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Electrical properties of a lead-free perovskite ceramic: (Na0.5Sb0.5)TiO3
Polycrystalline (Na0.5Sb0.5)TiO3 was prepared using a high-temperature solid-state reaction method. An XRD analysis indicated the formation of a single-phase monoclinic structure. Complex impedance studies revealed the presence of grain boundary effects from 300 °C onwards. Also, the dielectric relaxation in the system was found to be of a non-Debye type. The ac conductivity data were used to evaluate the density of states at the Fermi level, the minimum hopping length and activation energy of the compound. The dc electrical and thermal conductivities of grain and grain boundary have been assessed. The correlated barrier hopping model was found to successfully explain the mechanism of charge transport in (Na0.5Sb0.5)TiO3
Magnetic phase diagram of Fe1.1Te1-xSex: A comparative study with the stoichiometric superconducting FeTe1-xSex system
We report a comparative study of the series Fe1.1Te1-xSex and the
stoichiometric FeTe1-xSex to bring out the difference in their magnetic,
superconducting and electronic properties. The Fe1.1Te1-xSex series is found to
be magnetic and its microscopic properties are elucidated through Moessbauer
spectroscopy. The magnetic phase diagram of Fe1.1Te1-xSex is traced out and it
shows the emergence of spin-glass state when the antiferromagnetic state is
destabilized by the Se substitution. The isomer shift and quadrupolar splitting
obtained from the Moessbauer spectroscopy clearly brings out the electronic
differences in these two series.Comment: 6 pages, 9 figure
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