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41.
The Pr3+-doped tellurite zinc oxide (TZO) glasses by conventional melt and quenching technique have been prepared. The absorption spectra of samples doped with different concentrations of triply ionized praseodymium ions have been analyzed. Several upconversion emission bands of the Pr3+ ions doped in tellurite zinc oxide glasses under 980?nm excitation have been observed. The possible excitation mechanisms responsible for upconversion emissions spanning from blue to near infrared region have been discussed in detail. 相似文献
42.
The frequency upconversion (UC) emission throughout the visible region from the Y2O3:Ho3+?CTm3+?CYb3+ co-doped phosphors synthesized by using low temperature combustion process upon excitation with a diode laser operating at 980?nm have been presented. The colour emission tunability in co-doped phosphor has been observed on increasing the pump power and seen by the naked eyes. The tunability in colour emission has also been visualized by CIE chromaticity diagram. The variation in UC emission intensity of the 1G4????3H6 (Tm3+) and 5F3????5I8 (Ho3+) transitions lying in the blue region has been monitored with increase in the pump power and marked that their ratio can be used to determine the temperature. The developed phosphor has been used to record fingerprints. The observed most intense visible colour emission from the developed material may be used for photodynamic therapy and as an alternative of traditional fluorescent biolabels. 相似文献
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Balasubramanian K Kumar S Singh RR Sharma U Ahuja V Makharia GK Jagannathan NR 《Magnetic resonance imaging》2009,27(1):79-86
Metabolism of the colonic mucosa of patients with ulcerative colitis (UC; n=31) and Crohn's disease (CD; n=26) and normal mucosa (control, n=26) was investigated using in vitro high-resolution proton magnetic resonance spectroscopy. Of the 31 UC patients, 20 were in the active phase and 11 were in the remission phase of the disease. Out of 26 CD patients, 20 were in the active phase, while 6 were in the remission phase of the disease. Twenty-nine metabolites were assigned unambiguously in the perchloric acid extract of colonic mucosa. In the active phase of UC and CD, significantly lower (P相似文献
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Rokeya Akter Md. Habibur Rahman Deepak Kaushik Vineet Mittal Diana Uivarosan Aurelia Cristina Nechifor Tapan Behl Chenmala Karthika Manuela Stoicescu Mihai Alexandru Munteanu Cristiana Bustea Simona Bungau 《Molecules (Basel, Switzerland)》2021,26(17)
Extensive experimental, clinical, and epidemiological evidence has explained and proven that products of natural origin are significantly important in preventing and/or ameliorating various disorders, including different types of cancer that researchers are extremely focused on. Among these studies on natural active substances, one can distinguish the emphasis on resveratrol and its properties, especially the potential anticancer role. Resveratrol is a natural product proven for its therapeutic activity, with remarkable anti-inflammatory properties. Various other benefits/actions have also been reported, such as cardioprotective, anti-ageing, antioxidant, etc. and its rapid digestion/absorption as well. This review aims to collect and present the latest published studies on resveratrol and its impact on cancer prevention, molecular signals (especially p53 protein participation), and its therapeutic prospects. The most recent information regarding the healing action of resveratrol is presented and concentrated to create an updated database focused on this topic presented above. 相似文献
45.
Vineet K. Rai L. de S. Menezes C.B. de Araújo 《Applied Physics A: Materials Science & Processing》2008,91(3):441-443
Degenerate two-photon absorption (TPA) in a binary glass with composition TeO2-PbO is reported. The TPA coefficient, α2, obtained with nanosecond laser pulses at 532 and 590 nm, increases when the relative amount of PbO is increased. The maximum
TPA coefficient, α2= 12.6 cm/GW, is comparable to or larger than the values reported for crystalline semiconductors and other recently reported
glasses.
PACS 42.70.-a; 42.65.-k; 42.70.Ce; 42.62.Fi 相似文献
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Vineet Sharma Vinita Sharma Rakesh Bohra John E. Drake Michael B. Hursthouse Mark E. Light Ann L. Bingham 《Transition Metal Chemistry》2007,32(4):442-448
New heteroleptic oxovanadium(V) chloro oximato complexes of the type [VO{Cl}3-n
{ON=C(CH3)(Ar)}
n
] (where Ar = C4H3O-2, C4H3S-2, C5H4N-2 and n = 1 or 2) have been synthesized in excellent yields by the reaction of VOCl3 with the sodium salts of corresponding internally functionallized oximes in refluxing anhydrous benzene. The complexes are
characterized by elemental analyses and spectroscopic techniques (FT-IR, 1H-, 13C{1H}- and 51V-NMR). FAB mass spectral analysis of one of the derivatives, [VOCl{ON=C(CH3)C4H3S}2] indicates the monomeric nature of the complex. 51V-NMR spectral studies of these complexes suggest tetra-coordination around the vanadium atom in solution. However, the single
crystal X-ray diffraction study of a redistribution product [VOCl{ON=C(CH3)(C4H3S-2)}2] · CH3OH obtained on recrystallization of [VOCl2{ON=C(CH3)(C4H3S-2)}] from a methanol-hexane mixture shows the vanadium(V) atom is hepta-coordinated with distorted pentagonal bipyramidal
geometry. The oxo-atom occupies the axial position while the weakly coordinated CH3OH group is trans to the V=O atom. The two oximato ligands in the approximate pentagonal plane are bonded to the central vanadium atom in dihapto
(η2-N, O) manner with the formation of three-membered rings. The V–Cl bond occupies the fifth position in the approximate plane. 相似文献