Ho3+ To Yb3+ Back Transfer And Thermal Quenching Of Up-Conversion Green Emission In Fluoride-Crystals

Energy transfer from Ho3+ to Yb3+ has been demonstrated in fluoride crystals such as KYF4, BaY2F8, and LiYF4. This transfer was found to occur above a certain temperature and its efficiency increases with temperature. It accounts for the thermal quenching of green emission from upconverted Ho3+ and partly explains the failure, to date, to obtain room temperature, Yb3+ sensitized Ho3+ upconversion lasers in these three hosts. Low Yb3+ concentration is suggested for future attempts to achieve room temperature Yb3+, Ho3+ upconversion green laser operation of these crystals

The effects of escitalopram on myocardial apoptosis and the expression of Bax and Bcl-2 during myocardial ischemia/reperfusion in a model of rats with depression

BackgroundMajor depressive disorder (MDD) is an independent risk factor for coronary heart disease (CHD), and influences the occurrence and prognosis of cardiovascular events. Although there is evidence that antidepressants may be cardioprotective after acute myocardial infarction (AMI) comorbid with MDD, the operative pathophysiological mechanisms remain unclear. Our aim was therefore to explore the molecular mechanisms of escitalopram on myocardial apoptosis and the expression of Bax and Bcl-2 in a rat model of depression during myocardial ischemia/reperfusion (I/R).MethodsRats were divided randomly into 3 groups (n = 8): D group (depression), DI/R group (depression with myocardial I/R) and escitalopram + DI/R group. The rats in all three groups underwent the same chronic mild stress and separation for 21 days, at the same time, in the escitalopram + DI/R group, rats were administered escitalopram by gavage (10 mg/kg/day). Ligation of the rat¿s left anterior descending branch was done in the myocardial I/R model. Following which behavioral tests were done. The size of the myocardial infarction was detected using 1.5% TTC dye. The Tunel method was used to detect apoptotic myocardial cells, and both the Rt-PCR method and immunohistochemical techniques were used to detect the expression of Bcl¿2 and Bax.ResultsCompared with the D and DI/R groups, rats in Escitalopram + DI/R group showed significantly increased movements and sucrose consumption (P < .01). Compared with the DI/R group, the myocardial infarct size in the escitalopram + DI/R group was significantly decreased (P < .01). Compared with the D group, there were significantly increased apoptotic myocardial cells in the DI/R and escitalopram + DI/R groups (P < .01); however compared with the DI/R group, apoptotic myocardial cell numbers in the escitalopram + DI/R group were significantly decreased (P < .01). Compared with the DI/R group, there was a down-regulated Bax:Bcl-2 ratio in the escitalopram + DI/R group (P < .01).ConclusionsThese results suggest that in patients with AMI comorbid with MDD, there is an increase in pro-apoptotic pathways that is reversed by escitalopram. This suggests that clinically escitalopram may have a direct cardioprotective after acute myocardial infarction

Some integral inequalities on time scales

In this paper, some new integral inequalities on time scales are presented by using elementarily analytic methods in calculus of time scales.Comment: 8 page

Lamp-pumped laser performance of Nd3+:Sr-5(PO4)(3)F operating both separately and simultaneously at 1.059 and 1.328 mu m

Lamp-pumped laser performance of Nd3+-doped strontium fluorapatite, Sr-5(PO4)(3)F or S-FAP, has been characterized and compared with that of Nd3+-doped yttrium aluminum garnet (YAG) at both 1.06 and 1.3 mu m. Nd3+:S-FAP was found to exhibit lower thresholds and lower slope efficiencies than Nd3+:YAG. The former is attributed to the higher emission cross section, and the latter to lower Nd3+ concentration in S-FAP. The 1.3 mu m lasing of Nd3+:S-FAP is of particular interest because of its high emission cross section (2.4X10(-19) cm(2)). Q-switched and dual-wavelength lasing operation were also demonstrated in Nd3+:S-FAP

Efficient Laser Performance Of Ndgdlif4: A New Laser Crystal

Laser action of Nd3+ doped GdLiF4 (GLF) has been demonstrated for both pulsed and cw laser pumped operation. A slope efficiency of 60% was obtained in either manner of operation. The spectroscopic properties and laser performance of Nd:GLF are very similar to those of Nd:YLF. GLF, on the other hand, can be doped with much higher Nd3+ concentration

Effects of cadmium stress on growth, metal accumulation and organic acids of Spartina alterniflora Loisel.

A study quantifying the effects of exogenous cadmium (Cd) on growth, Cd bioaccumulation and organic acids of Spartina alterniflora was conducted. The experiment consisted of three levels of exogenous Cd2+ concentrations: 0, 50, and 200 mg/kg. Total Cd and water-soluble Cd were determined. Plant height, tiller number, spike number, electrolyte leakage rate (ELR), free proline, malondialdehyde (MDA), soluble sugar and organic acids were also measured. The results showed that plant height, tiller number and spike number reduced with increasing Cd2+ concentration. However, ELR, free proline, MDA, and soluble sugar were all promoted under Cd stress. Cd accumulated in inflorescences, leaves, stems, rhizomes and fine roots, and increased greatly with increasing Cd2+ concentration. Exogenous Cd2+ significantly reduced the growth of inflorescences, leaves, stems and rhizomes, with Cd accumulations not more than 15.68 μg/g dry weight (DW), respectively. However, biomass of fine roots did not reduce significantly with increasing Cd2+ concentration. Furthermore, Cd accumulation in fine roots reached to 390 μg/g DW under the treatment Cd200. Oxalic and citric acids were the two most abundant organic acids in S. alterniflora. Contents of oxalic acid in inflorescences, stems and fine roots were all positively related with Cd bioaccumulations indicating that oxalic acid might be related with Cd sequestration in fine roots and Cd transportation from underground to aboveground parts of S. alterniflora. Contents of citric acid in fine roots and ascorbic acid in rhizomes increased with increasing exogenous Cd2+ concentration, suggesting that accumulation of citric acids in fine roots and ascorbic acid in rhizomes of S. alterniflora might also be related to its Cd bioaccumulation and detoxification.Key words: Spartina alterniflora, cadmium pollution, growth, organic acid, phytoremediation

Blue Up-Conversion With Excitation Into Tm Ions At 780 Nm In Yb-Codoped And Tm-Codoped Fluoride-Crystals

Strong blue emissions have been observed in fluoride crystals, such as LiYF4, BaY2F8, and KYF4, codoped with Tm3+ and Yb3+ when excited into the Tm3+ 3F4 state at ∼780 nm. Energy transfer from Tm3+ to Yb3+ ions followed by the transfer from Yb3+ to Tm3+ was demonstrated to be responsible for the upconversion process. A pumping scheme is proposed based on this upconversion mechanism for blue-laser applications using these materials

s-ordered phase-sum and phase-difference distribuitons of entangled coherent states

The $s$-ordered phase-sum and phase-difference distributions are considered for Bell-like superpositions of two-mode coherent states. The distributions are sensitive, respectively, to the sum and difference of the phases of the entangled coherent states. They show loss of information about the entangled state and may take on negative values for some orderings $s$.Comment: 8 pages, 2 figures, iopart. accepted for publication in J. Opt. B: Quantum Semiclass Op

C-terminal truncated hepatitis B virus X protein promotes hepatocellular carcinogenesis through induction of cancer and stem cell-like properties

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