2-.mu.m fiber amplified spontaneous emission (ASE) source

A 2-.mu.m fiber Amplified Spontaneous Emission (ASE) source provides a wide emission bandwidth and improved spectral stability/purity for a given output power. The fiber ASE source is formed from a heavy metal oxide multicomponent glass selected from germanate, tellurite and bismuth oxides and doped with high concentrations, 0.5-15 wt. %, thulium oxides (Tm.sub.2O.sub.3) or 0.1-5 wt% holmium oxides (Ho.sub.2O.sub.3) or mixtures thereof. The high concentration of thulium dopants provide highly efficient pump absorption and high quantum efficiency. Co-doping of Tm and Ho can broaden the ASE spectrum

Modification of wool fiber using steam explosion

Wool fiber was modified by steam explosion in this study. SEM results show that some scales on the fiber surface were cleaved and tiny grooves generated during the explosion. FTIR results suggest no evident changes in the chemical composition of the fiber after the explosion treatment. However, the crystallinity of the fiber decreased slightly as the steam pressure increased based on the X-ray results. In the thermal analysis, DSC results show that the temperature corresponding to vaporization of absorbed water and cleavage of disulfide bonds respectively decreased as the steam pressure increased. The reduction in thermal decomposition energy of the treated fiber indicates that steam explosion might have destroyed some crystals and crosslinks of macromolecular chains in the fiber. The treatment also led to some alterations of the fiber properties, including reduction in strength, moisture regain and solubility in caustic solution.<br /

5-HT1A Receptor Agonist Promotes Retinal Ganglion Cell Function by Inhibiting OFF-Type Presynaptic Glutamatergic Activity in a Chronic Glaucoma Model

Serotonin receptors are potential neuroprotective agents in degenerative diseases of the central nervous system. The protective effects of serotonin receptor (5-HT1A) agonists on the survival and function of retinal ganglion cells (RGCs) by regulating the release of the presynaptic neurotransmitter γ-aminobutyric acid (GABA) were confirmed in our previous study of a chronic glaucoma rat model. However, the roles of excitatory amino acids and their interactions with the 5-HT1A receptor in glaucoma remain unknown. Here, we found that ocular hypertension increased glutamine synthetase (GS) and excitatory amino acid transporter 2 (EAAT2) expression in rat retinas. In addition, the high expression of GS and EAAT2 induced by glaucoma was downregulated by the 5-HT1A receptor agonist 8-OH-DPAT and the 5-HT1A receptor antagonist WAY-100635, respectively. Patch-clamp techniques were used to record glutamate receptor-mediated spontaneous and miniature glutamatergic excitatory post-synaptic currents (sEPSCs and mEPSCs) as well as L-glutamate-induced current in OFF-type and ON-type RGCs in rat retinal slices. Although there were no significant differences in the frequency and amplitude of sEPSC and mEPSC release between normal and glaucoma OFF- and ON-type RGCs, exogenous 8-OH-DPAT administration specifically reduced the frequency, but not the amplitude, of sEPSC and mEPSC release in glaucoma OFF-type rather than ON-type RGCs; these effects were completely blocked by WAY-100635. In summary, 8-OH-DPAT decreases and increases GS and EAAT2 expression of glaucomatous retina, respectively, while decreasing sEPSC and mEPSC frequency. In contrast, WAY-100635 increases and decreases GS and EAAT2 expression of glaucomatous retina, respectively, while increasing sEPSC and mEPSC frequency. The reduction of glutamatergic presynaptic transmission by 8-OH-DPAT deactivates RGCs at the neural network level and reduces the excitotoxic damage in the pathological process of chronic glaucoma

PROTOPANAXADIOL SAPONINS IN THE CAUDEXES AND LEAVES OF PANAX NOTOGINSENG COULD BE THE MAIN CONSTITUENTS THAT CONTRIBUTE TO ITS ANTIDEPRESSANT EFFECTS

Objective: We previously found that total saponins, purified from the caudexes and leaves of Panax notoginseng (SCLPN), had antidepressant effects. In the present study, we investigated saponin monomers of SCLPN that may be the main constituents that contributeÂ&nbsp;toÂ&nbsp;theÂ&nbsp;antidepressantÂ&nbsp;effects of SCLPN. Methods: Three effective fractions of SCLPN, purified using a macroporous resin method, at doses of 50 and 100 mg/kg were tested in four different animal models of stress, including the learned helplessness test, tail suspension test, forced swim test, open field test, and reserpine-induced syndrome model. Using the same models of stress and the same doses, we then evaluated the antidepressant effects of four main and representative saponin monomers (ginsenosides Rd, Rb1 and Rg1 and notoginsenoside R1) in different effective fractions. We also examined the effects of Rd and Rb3 on monoamine neurotransmitter levels. To investigate the biotransformation of Rb1 and Rb3 orally administered in mice, Rb1 and Rb3 metabolites in blood and brain were determined by high-performance liquid chromatography. Results: Effective fraction A and C exerted greater antidepressant effects than fraction B in the behavioral tests and reserpine-induced syndrome model. Among the four saponin monomers, Rd had the strongest antidepressant effects, which improved depressive-like behavior in all four animal models of depression. We then found that Rb3 (50 and 100 mg/kg) and Rd (100 mg/kg) increased the levels of 5-hydroxytryptamine, dopamine, and norepinephrine, whereas 50 mg/kg Rd had no effect on the levels of these three neurotransmitters. Ginsenoside Rh2, C-K, and 20 (S)-protopanaxadiol saponins were detected in blood samples from mice that received Rb1 and Rb3, and protopanaxadiol saponins were found in the brain. Conclusion: The present results indicate that protopanaxadiolÂ&nbsp;saponinsÂ&nbsp;in SCLPN have potential antidepressant-like effects