Visible upconversion emissions in Pr3+-doped TeO2–ZnO glass

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.     

Colour emission tunability in Ho3+–Tm3+–Yb3+ co-doped Y2O3 upconverted phosphor

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.     

Metabolism of the colonic mucosa in patients with inflammatory bowel diseases: an in vitro proton magnetic resonance spectroscopy study

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   

Chemo-Preventive Action of Resveratrol: Suppression of p53—A Molecular Targeting Approach

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.     

Two-photon absorption in TeO2-PbO glasses excited at 532 and 590 nm

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     

Comparative qualitative analysis of different classes of compounds in selected Australian and Indian Eucalyptus and Corymbia species: a convenient de-replication method for the eucalypts

JPC – Journal of Planar Chromatography – Modern TLC - Eucalypts are a large group of woody trees with about 900 taxa in 3 genera: Eucalyptus, Corymbia and Angophora. The secondary...     

Synthesis of novel 7-fluoro-3-substituted-1,2,4-triazolo[3,4-b]benzothiazoles (FTBs) as potent antifungal agents: molecular docking and in silico evaluation

Research on Chemical Intermediates - A novel series of fluorinated 1,2,4-triazolo[3,4-b]benzothiazoles was synthesized by fusion of proven antifungal lead 1,2,4-triazole with flourinated...     

Synthesis and characterization of some oxovanadium(V) complexes with internally functionallized oximes. Crystal and molecular structure of heptacoordinated [VOCl{ON=C(CH3) (C4H3S-2)}2] · CH3OH

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.