Photoluminescence Properties of Cyan-Emitting Lu3GaxAl5-xO12: Ce3+ Garnet Phosphors Synthesized in Nonreducing Atmosphere and at Different Temperature for High Quality w-LEDs.

The existence of so-called blue-green cavities in the luminescence spectrum has been a hindrance to the improvement in the performance of traditional phosphor-converted white light emitting diodes. The commercial phosphors synthesized in reducing atmospheres can also cause problems such as equipment complexity, increased cost, and environmental pollution. Herein, a series of cyan-emitting Lu3GaxAl5-xO12: Ce3+ (x = 0, 1, 2, 3, 4) garnet phosphors were synthesized by a traditional solid-state reaction in a nonreducing atmosphere at different temperatures. The crystal structure, grain morphology, optical properties, and thermal quenching behavior were used to analyze the optical properties of the as-prepared phosphors. The luminescence intensity of samples is affected by the synthesis temperature and energy gap between the conduction band and the lowest energy of the 5d excited state of the host lattice. With the substitution of Al3+ by Ga3+, the regularity of the excitation and emission band movement is determined by the combined effects of crystal field splitting (CFS) and the nephelauxetic effect (NE). The temperature dependence of luminescence was studied. The thermal quenching mechanism was clarified by the thermal ionization model. Finally, by employing Lu2.94Ga2Al3O12: Ce3+0.06 as a cyan component, a w-LED with a high color rendering index of 93.2 and low correlation color temperature of 3880 K based on a blue chip and commercial red phosphors were fabricated in order to explore its possible application in high quality w-LED.

Different Surface Appearances Caused by Unbalanced Mn2+ Accumulation in Gallstones Consisting of Cholesterol and CaCO3 Obtained from a Patient After Cholecystectomy.

Gallstones were examined for 58 patients in Jilin, Jilin. It was found that gallstones from only one who suffered from cholecystectomy were composed of 20 spheroidal stones and they rarely exhibited three different types of surface appearances. Six representative powder samples were analyzed for gallstones compositions and Mn2+ using X-ray diffraction (XRD)/Infrared (IR) and electron spin resonance (ESR), respectively. The results suggested that all gallstones from this patient were identified by XRD to be gallstones consisting mainly of cholesterol and CaCO3 (GCCC). They rarely exhibited three different kinds of surface appearances corresponding to different concentration of trace Mn2+ in calcite (CMn2+/CCal): 18 dark/light brown spheres with smooth surfaces and CMn2+/CCal = 0-6 µg/g/%, a yellowish-brown huge sphere with a rougher surface and CMn2+/CCal = 30 µg/g/%, and an ashy sphere composed of tens of microspheres with the roughest surface and CMn2+/CCal = 60 µg/g/%. The difference in surface appearance showed significant association with CMn2+/CCal, and its increase made the gallstone's surface change from smooth to rough and to fade in color. The unbalanced and competitive Mn2+ accumulation could occur occasionally in individual stones owing to different affinities to Mn2+, resulting in the formation of a huge stone and an ashy sphere. These two aberrations caused by higher CMn2+/CCal played an important role in suppressing the crystalline growth of the majority of dark/light brown spheres. GCCC from a patient might have a prominent Mn2+ partitioning feature corresponding to different surface appearances.

[The study of CD4+ and CD8+ T subsets in chronic hepatitis B patients].

AIM: To investigate the difference of CD4+ and CD8+ T subsets in different infection status of chronic hepatitis B (CHB) patients. METHODS: 13 Healthy people were chosen as control group. According to infection status, 78 CHB patients were sorted into HBeAg(+) and normal liver function group, HBeAg(+) and abnormal liver function group, and HBeAg(-) group. The percentages of some subsets of CD4+T and CD8+T cells in CHB patients and healthy people were examined by Flow cytometer, and the correlations between the subsets of T cells and the HBVDNA levels and HBeAg were analyzed. RESULTS: As compared with control group, the percentages of CD4+CD25+/CD4+ and CD4+CD95+/CD4+ were increased (P<0.01, P<0.05) in HBeAg(+) and normal liver function group, and the percentages of CD8+CD28-/CD8+ in three patients groups were increased (P<0.01). As compared with the HBeAg(+) and normal liver function group, the percentages of CD4+CD25+/CD4+ in HBeAg(+) and abnormal liver function group, and HBeAg(-) group were decreased (P<0.01), and the percentages of CD8+CD95+/CD8+ in HBeAg(-) group and the percentages of CD8+CD95+/CD8 in HBeAg(+) and abnormal liver function group were decreased (P<0.05, P<0.01). Moreover, there were positive correlations between CD4+CD25+/CD4+, CD4+CD95+/CD4+ and the HBVDNA levels(P<0.01); there were inverse correlations between CD4+CD28+/CD4+ and the HBVDNA levels and HBeAg (P<0.05, P<0.01); there were positive correlations between CD8+CD28-/CD8+ and HBVDNA and HBeAg (P<0.01). CONCLUSION: Some T cell Subsets, including CD4+CD25+, CD4+CD95+ , and CD8+CD28-, are increased in CHB patients, which maybe play some roles in the immune tolerance of chronic HBV infection.