AIM To investigate the antioxidant effects of Morinda officinalis (Morindae radix, MR) on H(2)O(2)-induced oxidative stress in cultured mouse TM3 Leydig cells. METHODS We carried out 2,2-diphenyl-1-picrylhydrazyl free radical scavenging, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, lipid peroxidation, testosterone enzyme immunoassay, superoxide dismutase (SOD), and catalase (...

We report a localized surface plasmon enhanced upconversion luminescence in Au/SiO2/Y2O3:Yb3+,Er3+ nanoparticles when excited at 980 nm. By adjusting the silica spacer's thickness, a maximum 9.59-fold enhancement of the green emission was obtained. Effect of the spacer distance on the Au-Y2O3:Yb3+, Er3+ green upconversion mechanism was numerically simulated and experimentally demonstrated. In t...

The 2.1-/im 5I7-518 laser transition in Ho3+ is attractive because of its long upper laser level lifetime, of the order of 5 msec, and its eye-safe wavelength. However, this laser typically is cooled to liquid-N2 temperatures to achieve continuous-wave (cw) or high-repetition-rate operation because its lower laser level is in the ground-state manifold, a few hundred inverse centimeters above th...

Er3+-doped and Er3+,Yb3+-co-doped Gd2O2S are one of the most efficient upconversion (UC) materials available to date. However, preparing lanthanide oxysulfides can be challenging as it requires several hours heating at>1000 °C in high power furnaces. Nonetheless, designing a new synthesis technology for UC materials, should consider that these systems suffer from defect quenching, responsible s...

K6Yb3(PS4)5 possesses two identical but interlocked three-dimensional frameworks. Each framework is realized by having Yb3+ atoms adopt both octahedral and trigonal prismatic sulfur coordination.

Opioid receptors like other G-protein-coupled receptors undergo specific rearrangements of structure upon activation by agonists. Such processes proceed via several steps ruled by different molecular switches. In order to reveal the first steps of receptor activation concurrent with ligand binding, we investigated μ opioid receptor complexes with antagonists naltrexone and -FNA, and two closely...

We present a non-contact optical technique for the measurement of laser-induced temperature changes in solids. Two-band differential luminescence thermometry (TBDLT) achieves a sensitivity of 7 mK and enables a precise measurement of the net quantum efficiency of optical refrigerator materials. The TBDLT detects internal temperature changes by decoupling surface and bulk heating effects via tim...

Yb3+-doped phosphate glasses containing different amounts of SiO₂ were successfully synthesized by the conventional melt-quenching method. The influence mechanism of SiO₂ on the structural and spectroscopic properties was investigated systematically using the micro-Raman technique. It was worth noting that the glass with 26.7 mol % SiO₂ possessed the longest fluorescence lifetime (1.51 ms), the...