Yanxia Zheng,Gang Dong,Liyong He,Gang Wu,Huade Zheng,Chunlin Deng
Calcium phosphate layers, which are widely applied on the surface of biomaterials, are important for improving tissue regeneration performance. The composition of layers formed on the surface of biomaterials differs depending on the soaking fluid. Herein, revised simulated blood fluid and fast calcification solution were investigated as immersing solutions for the mineralization of hydroxyapatite ceramics. The morphology of the hydroxyapatite particles and precipitate formation on the hydroxyapatite ceramics surface were characterized by transmission electron microscopy . Furthermore, scanning electron microscopy was used to examine the morphology of the bioactive ceramics surface. The structure of the layers was determined by selected-area electron diffraction. The prepared hydroxyapatite powders were characterized by powder X-ray diffraction. The results showed that hydroxyapatite was preferentially formed on the hydroxyapatite ceramics surface in revised simulated blood fluid and octacalcium phosphate precipitated in fast calcification solution. Additionally, the content of HCO 3 - in the mineralization fluid strongly influenced the crystal phase composition and morphology of the calcium phosphate layers on the bio-ceramics materials studied herein.
Jinjia Guo,Yongmei Wang,Zhao Luo,Feng Zhang,Dewang Yang
Carbon cycle in coastal water is a significant dynamic component of global carbon budget , however, the diverse sources, carbon sinks and their complex interactions remained poorly understood. In order to detect the dissolved inorganic carbon (DIC) and their interactions, gas-liquid Raman spectroscopy was built and applied to simultaneously detect the constituents of air, dissolved CO 2 , HCO 3 - and chlorophyll in coastal water. The linear fitting curve between peak intensity and concentration was built for the quantitative analysis of HCO 3 - and CO 2 , meanwhile, the fluorescence peaks of chlorophyll at 679 nm were detected for the qualitative analysis. For the multi-components analysis, typical Raman spectra of the constituents of air, dissolved CO 2 , HCO 3 - in seawater, and the fluorescence spectra of chlorophyll in seawater were detected. Results showed that the time dependent change of CO 2 and O 2 in the air exhibited a contrary tendency, while that of dissolved CO 2 and O 2 was curved like a cosine. The changing tendency of relative concentrations of dissolved CO 2 was about 2 h earlier than CO 2 in air, due to the life activity of microorganisms driving the gas exchange at the air-sea interface. Furthermore, the study makes a study on the relationship between DIC and chlorophyll based on the detection of HCO 3 - and chlorophyll in coastal water, indicating that this gas-liquid Raman spectroscopy could successfully provide real-time analysis of multicomponent DIC in the air-sea exchanging process.