770 research outputs found
The generalized gradient approximation kernel in time-dependent density functional theory
A complete understanding of a material requires both knowledge of the excited
states as well as of the ground state. In particular, the low energy
excitations are of utmost importance while studying the electronic, magnetic,
dynamical, and thermodynamical properties of the material. Time-Dependent
Density Functional Theory (TDDFT), within the linear regime, is a successful
\textit{ab-initio} method to access the electronic charge and spin excitations.
However, it requires an approximation to the exchange-correlation (XC) kernel
which encapsulates the effect of electron-electron interactions in the
many-body system. In this work we derive and implement the spin-polarized XC
kernel for semi-local approximations such as the adiabatic Generalized Gradient
Approximation (AGGA). This kernel has a quadratic dependence on the wavevector,
{\bf q}, of the perturbation, however the impact of this on the electron energy
loss spectra (EELS) is small. Although the GGA functional is good in predicting
structural properties, it generality overestimates the exchange spin-splitting.
This leads to higher magnon energies, as compared to both ALDA and experiment.
In addition, interaction with the Stoner spin-flip continuum is enhanced by
AGGA, which strongly suppresses the intensity of spin-waves.Comment: 11 pages, 7 figure
Pollen germination studies in Giant Himalayan Lily (Cardiocrinum giganteum Wall.) a high value of ornamental plant in Western Himalayan region
Giant Himalayan lily (Cardiocrinum giganteum Wall.) is a perennial bulbiferous herb of Liliaceae and an endemic species in the eastern Himalayan region, which has become one of the new flower crops because of its high ornamental value. The present investigationwas conducted to study pollen morphologyi.e., fresh pollen grains size was measured in different media, viz., water, acetocarmine, glycerol and without any medium (dry). The pollen grains of Giant Himalayan lily exhibited the average size (length x width) of (22.64 x 19.72Ό) in water suspension. The result revealed that in glycerine and dry condition shape of pollen grains was perprolate. However, in water and acetocarmine it looked was round in shape. The result also shown that highest pollen germination (54.70%, 63.69%) and pollen tube growth (89.24Ό, 175.85Ό) in 10% sucrose solution for 12 hours and 24 hours respectively. In control light treatments, red light was found to be best in pollen germination and pollen tube growth
A Preliminary Study on Phytoplankton in Fresh Water-Lake of Gogi, Yadgir District, Karnataka
The present study was conducted in a semi arid region of Karnataka. The study discusses the phytoplankton diversity of the Gogi lake ecosystem. A standard methodology was followed in conducting to complete this study and samples were collected at different points from the lake ecosystem located at the core area of the proposed uranium mining site. Through a field survey, twenty one species of phytoplankton were recorded coming under four classes viz., Bacillariophyceae(8), Chlorophyceae(7),Cyanophyceae (5) Charophyceae (1) and twelve families and Fragilariaceae (4), Bacillariaceae (3), Zygnemataceae(3), Desmidiaceae (2), Oscillatoriaceae (2), Melosiraceae (1), Cladophoraceae (1), Scenedesmaceae (1), Microcystaceae (1), Nostocaceae (1), Phormidiaceae (1), Characeae (1). The data were collected over two seasons- March to May and September to November -2012. A total of 21 species were recorded from the study region of which 10 species were recorded during March to May, while 02 species from September to November, nine species were recorde
Primary pulmonary non hodgkinâs T cell lymphoma
A 55-year-old female presented with history of fever, dry cough and right sided chest pain of two months duration. Radiological examination revealed a soft tissue attenuated lesion involving right middle lobe. Immuno histochemical analysis leads to the diagnosis of Non Hodgkinâs T-cell Lymphoma. The rarity of this disorder and its good clinical and radiological response to chemotherapy prompted us to report this case
Effet de la salinité sur la croissance et la production de biomasse de deux provenances de Jatropha curcas L. cultivés en serre
La salinisation des sols est un processus important de dĂ©gradation des sols. Ce phĂ©nomĂšne ne cesse de prendre de lâampleur. Il affecte la croissance et le rendement des cultures. Lâutilisation dâespĂšces Ă usages multiples telle que Jatropha curcas L. et capable de se dĂ©velopper dans ces milieux est dâune importance capitale. Cette Ă©tude a portĂ© sur lâeffet de diffĂ©rentes concentrations de NaCl (0 g/l, 2 g/l, 4 g/l, 8 g/l, 16 g/l et 35 g/l) pendant une durĂ©e de 42 jours sur des jeunes plants de deux provenances (Nioro et Kaffrine) de Jatropha curcas L en condition de serre vitrĂ©e. La tolĂ©rance des deux provenances par rapport aux diffĂ©rentes concentrations de NaCl a Ă©tĂ© Ă©tudiĂ©e en tenant compte des paramĂštres de croissance et de rendement. Les rĂ©sultats ont montrĂ© que la hauteur des tiges, le diamĂštre au collet, la biomasse sĂšche des parties aĂ©riennes et des parties racinaires Ă©valuĂ©s Ă la fin de lâexpĂ©rience varient en fonction du niveau du stress salin. Les deux provenances ont montrĂ© une tolĂ©rance Ă la salinitĂ© manifestĂ©e par la rĂ©duction dâun appareil aĂ©rien et racinaire important. La provenance Nioro prĂ©sente une croissance des organes aĂ©riens plus importante que celle de Kaffrine. Cependant, la provenance Kaffrine produit plus de biomasse sĂšche aĂ©rienne. Cette diffĂ©rence se situe au niveau de la quantitĂ© de biomasse sĂšche apportĂ©e par les tiges.Mots clĂ©s : Stress salin, croissance, biomasse, Jatropha curcas L., provenance
Swyer- James -MacLeod syndrome presenting as hemoptysis in an adult
Swyer-James/MacLeod syndrome is an uncommon disease with characteristic radiological feature of unilateral hyperlucency due to loss of pulmonary vasculature and air trapping. Typically, this disorder is diagnosed in childhood during evaluations for recurrent respiratory infections. Here, we report a case in a 30-year-old adult female who presented with dyspnoea, cough with expectoration and recurrent hemoptysis due to associated bronchiectasis. This case highlights the importance of computed tomography in the diagnostic workup of recurrent hemoptysis in pulmonary tuberculosis epidemic countries like India
Combination of dasatinib and curcumin eliminates chemo-resistant colon cancer cells
Metastatic colorectal cancer remains a serious health concern with poor patient survival. Although 5-Fluorouracil (5-FU) or 5-FU plus oxaliplatin (FOLFOX) is the standard therapy for colorectal cancer, it has met with limited success. Recurrence of the tumor after chemotherapy could partly be explained by the enrichment of the chemo-resistant sub-population of cancer stem cells (CSCs) that possess the ability for self-renewal and differentiation into different lineages in the tumor. Therefore development of therapeutic strategies that target CSCs for successful treatment of this malignancy is warranted. The current investigation was undertaken to examine the effectiveness of the combination therapy of dasatinib (a Src inhibitor) and curcumin (a dietary agent with pleiotropic effect) in inhibiting the growth and other properties of carcinogenesis of chemo-resistant colon cancer cells that are enriched in CSCs sub-population. Remnants of spontaneous adenomas from APCMin +/- mice treated with dasatinib and/or curcumin were analyzed for several cancer stem cell markers (ALDH, CD44, CD133 and CD166). Human colon cancer cells HCT-116 (p53 wild type; K-ras mutant) and HT-29 (p53 mutant; K-ras wild type) were used to generate FOLFOX resistant (referred to as CR) cells. The effectiveness of the combination therapy in inhibiting growth, invasive potential and stemness was examined in colon cancer CR cells. The residual tumors from APCMin +/- mice treated with dasatinib and/or curcumin showed 80-90% decrease in the expression of the CSC markers ALDH, CD44, CD133, CD166. The colon cancer CR cells showed a higher expression of CSCs markers, cell invasion potential and ability to form colonospheres, compared to the corresponding parental cells. The combination therapy of dasatinib and curcumin demonstrated synergistic interactions in CR HCT-116 and CR HT-29 cells, as determined by Calcusyn analysis. The combinatorial therapy inhibited cellular growth, invasion and colonosphere formation and also reduced CSC population as evidenced by the decreased expression of CSC specific markers: CD133, CD44, CD166 and ALDH. Our data suggest that the combination therapy of dasatinib and curcumin may be a therapeutic strategy for re-emergence of chemo-resistant colon cancer by targeting CSC sub-population
A comparative study of various diagnostic techniques for Cryptosporidiosis
Abstract: Diarrhoeal disease is a common complication of infection with HIV. Cryptosporidium has gained importance as an AID
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