[Microanalysis study of the inspirable nano-particles into lungs by SEM and XREDS].

Inspirable nano-particles into lungs in the atmosphere were studied in this paper. Field emission scanning electron microscope (FSEM) and X-ray energy dispersive spectrometer were used to investigate the morphology and major constituents of inspirable nano-particles into lungs systematically. The results showed that most of the inspirable nano-particles in the atmosphere are spherical and ellipsoidal, with smooth surface and dense structure. The smaller nano-particles are clustered into loose floccule, with the sizes in the range of 30 to 100 nm. The constant elements in the nano-particles are close consistent with the large particle pollutants, which mainly contain C, O, Al, Si, Na, Mg, K, Ca, Fe, S and Cl etc. The point Analysis of EDS confirmed that the element content of Cl and S in some nano-particles is significantly increased, while others mainly contain C and O. It is believed that the surface of nano inorganic dust particles was adsorbed by the organic pollutants to form the core-shell structure nano-particles pollutants in the process of aerosol formation. Thus, reducing anthropogenic emissions of organic pollutants has great influence on the formation of inspirable nano-particles.

[Microanalysis study of Co-doped ZnO DMS crystal by SEM and XREDS].

In the present paper,with CoCl2 x 6H2O used as precursor, Co-doped ZnO diluted magnetic semiconductor (DMS) crystals were synthesized by hydrothermal method with KOH as mineralizer. The morphology, and the relative content and distribution uniformity of the surface and inner Co element of synthesized crystals were investigated by scanning electron microscope (SEM) and X-ray energy dispersive spectrometry (XREDS), respectively. It was found that Co-doped ZnO crystals with different morphology were yielded, while the bigger crystals showed polar growth charactertistics, and the Co content in the crystal depended on its morphology. The exposed face also changed with crystal morphology. There was more Co in bigger crystals than in smaller ones. Moreover, more Co located in +c (10 11)compared to +c (10 10) exposed face, especially for cone crystals. In addition, it was observed that there was a little amount of cobalt oxide cluster in inner crystal,and the distribution of Co content was relative uniform in both the surface and inner part of the crystal. Cobalt oxide cluster may have effect on the magnetic properties of Co-doped ZnO diulted magnetic semiconductor since Co2+ possesses magnetic property.

[Synthesis and luminescent properties of novel red phosphor SrO . Y2O3 : Eu].

A novel red-emitting phosphor SrO . Y2O3 : Eu was synthesized by glycine combustion process. The phases and structure, the size and morphology, and the luminescent properties of the samples were investigated respectively by XRD, SEM and fluorescence spectrophotometer (FL). The results show that the samples include two phases, SrY2O4 and Y2O3, which belong to orthorhombic system and cubic system respectively. The particles of SrO . Y2O3 : Eu obtained at 1 200 degrees C are nearly spherical in shape, and the mean grain size is in the range of 100-200 nm. The excitation spectrum of SrO . Y2O3 : Eu phosphor shows a broad band with a main peak around 280 nm, which is due to the charge-transfer (CT) in the excitation of an electrons from the oxygen 2p state to an Eu3+ 4f state. Excited with a radiation of 280 nm, the phosphor emits strong red fluorescence, and the main emission peak is around 592 nm, which can be assigned to the transition of 5D0 -->7 F1 of Eu3+ ion. Another strong emission peak is at 614 nm, which can be assigned to the transition of 5D0 --> 7 F2 Of Eu3+ ion. Moreover, it was found that the ratio of glycine to nitrate ion, calcinations temperature and the concentration of Eu3+ have significant effect on the luminescent intensity of SrO . Y2O3 : Eu.

[Synthesis of the red long afterglow phosphor Gd2O2S: Eu, Mg, Ti by microwave radiation method and its luminescent properties].

Gd2O2S: Eu, Mg, Ti, a novel red long afterglow phosphor, was synthesized in microwave field. The synthesized phosphors were investigated respectively by XRD, SEM and fluorescence spectrophotometer. The results show that Gd2O2S: Eu, Mg, Ti phosphors possess hexagonal crystal structure, which is similar to that of Gd2O2S. The particles of Gd2O2S: Eu, Mg, Ti phosphors are basically spherical in shape, with good dispersing. The mean particle size is 1-2 microm. The excitation spectrum is a broad band and the main peak is at 360 nm. Moreover, excitation peaks at 400, 422 and 472 nm were found in the excitation spectrum. The emission spectrum shows that Gd2O2S: Eu, Mg, Ti has narrow emission peaks. The emission peaks are ascribed to Eu3+ ions transition from 5 D(J) (J = 0, 1, 2) to 7F(J) (J = 0, 1, 2, 3, 4). With the increase in Eu3+ molar ratio, the emission peaks at 586, 557, 541, 513, 498, 471 and 468 nm in the blue and green region weaken gradually relative to the main emission peak at 627 nm. Therefore the red emitting at 627 nm becomes strong gradually. When the molar ratio is 6%, the red emitting becomes the strongest. The Ti and Mg co-doping can obviously improve its long-afterglow property.

Transglutaminase-2 is Involved in Cell Apoptosis of Osteosarcoma Cell Line U2OS Under Hypoxia Condition.

Osteosarcoma is the most common type of solid bone cancer, which is the second leading cause of cancer-related death. Hypoxia is an ordinary phenomenon in solid tumor tissues and can induce cell apoptosis but the specific molecular mechanism remains unclear. In this study, we explored the effect and the molecular mechanism of Transglutaminase 2 (TG2) on cell apoptosis in osteosarcoma U2OS cells under hypoxia. We found the enzymatic activity of TG2 is significantly increased and the expression of TG2 is remarkably up-regulated under hypoxia condition. Cell apoptotic rate is markedly increased upon knockdown of TG2 by siRNA under hypoxia. We further investigated the mechanism of cell apoptosis and found Bax protein is significantly increased after depletion of TG2 under hypoxia. Moreover, our data also show that cytochrome C (Cyt C) is significantly increased in cytoplasm and markedly decreased in mitochondria of U2OS cells after depletion of TG2 under hypoxia. Our results suggest that TG2 can inhibit tumor cell apoptosis through down-regulation of Bax and prevention of release Cyt C from mitochondria into cytoplasm.

[Preparation of nanocrystal Gd2O3: Eu by EDTA complexing sol-gel process and spectroscopic study].

Gd2O3: Eu nanocrystal was synthesized by EDTA complexing sol-gel process at relatively low temperature, in which ethylene-diamine-tetraacetic acid (EDTA) and polyethylene glycol (PEG) were used as the chelating agent and disperser respectively. The properties of the nanocrystal were investigated by XRD, SEM, EDS, and fluorescence spectrophotometer. The results show that nanosized, homogenous and pure cubic phase Gd2O3: Eu has been produced after the precursor calcined at 800 degrees C for 2 h. The particles of the Gd2O3: Eu are basically spherical in shape and about 30 nm in size. The main emission peak of Gd2O3: Eu nanocrystal is at 611 nm, resulting in a red emission. Compared with micron scale Gd2O3: Eu phosphors prepared by a conventional method, a clear red shift occurs in the excitation spectrum of Gd2O3: Eu nanocrystal prepared by the present work, and the quenching concentration of Eu has been raised. For this type of nanophosphor, quenching starts at an Eu concentration of 8% (mol%), while a value of 6% was obtained for the conventional one.