5,203 research outputs found

    Quantum corrections to conductivity for semiconductors with various structures

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    We study the magnetic field dependences of the conductivity in heavily doped, strongly disordered 2D quantum well structures within wide conductivity and temperature ranges. We show that the exact analytical expression derived in our previous paper [1], is in better agreement than the existing equation i.e. Hikami(et.al.,) expression [2,3], with the experimental data even in low magnetic field for which the diffusion approximation is valid. On the other hand from theoretical point of view we observe that our equation is also rich because it establishes a strong relationship between quantum corrections to the conductivity and the quantum symmetry su_{q}(2). It is shown that the quantum corrections to the conductivity is the trace of Green function made by a generator of su_{q}(2)algebra. Using this fact we show that the quantum corrections to the conductivity can be expressed as a sum of an infinite number of Feynman diagrams.Comment: 15 pages, 6 figures. To appear in International journal of modern physics

    Glyco-biomarkers: Potential determinants of cellular physiology and pathology

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    Once dismissed as just the icing on the cake, sugar molecules are emerging as vital components in life’s intricate machinery. Our understanding of their function within the context of the proteins and lipids to which they are attached has matured rapidly, and with it the far reaching clinical implications are becoming understood. Recent advances in high-throughput glycomic techniques, glyco biomarker profiling, glyco-bioinformatics and development of increasingly sophisticated glyco-arrays, combined with our increased understanding of the molecular details of glycosylation have facilitated the linkage between aberrant glycosylation and human diseases, and highlighted the possibility of using glyco-biomarkers as potential determinants of disease and its progression. The focus of this review is to give an insight into the biological significance of these glycomodifications, highlight some specific examples of glyco-biomarkers in relation to autoimmunity and in particular rheumatoid arthritis, and to explore the exciting possibility of exploiting these for diagnostic and prognostic strategies

    Hyperfine splitting in noncommutative spaces

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    We study the hyperfine splitting in the framework of the noncommutative quantum mechanics (NCQM) developed in the literature. The results show deviations from the usual quantum mechanics. We show that the energy difference between two excited F = I + 1/2 and the ground F = I - 1/2 states in a noncommutative space (NCS) is bigger than the one in the commutative case, so the radiation wavelength in NCSs must be shorter than the radiation wavelength in commutative spaces. We also find an upper bound for the noncommutativity parameter.Comment: No figure

    Scattering in Noncommutative Quantum Mechanics

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    We derive the correction due to noncommutativity of space on Born approximation, then the correction for the case of Yukawa potential is explicitly calculated. The correction depends on the angle of scattering. Using partial wave method it is shown that the conservation of the number of particles in elastic scattering is also valid in noncommutative spaces which means that the unitarity relation is held in noncommutative spaces. We also show that the noncommutativity of space has no effect on the optical theorem. Finally we study Gaussian function potential in noncommutative spaces which generates delta function potential as θ0\theta \to 0.Comment: 7 Pages, no figure, accepted for publication in Modern Physics Letters
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