Structural features of hydroxyapatite and carbonated apatite formed under the influence of ultrasound and microwave radiation and their effect on the bioactivity of the nanomaterials

The samples of hydroxyapatite and carbonate substituted hydroxyapatite (CHA) were obtained under the influence of physical factors, namely ultrasound (US) and microwave (MW) radiations. The results of Fourier transform infrared spectroscopy and X-ray diffraction analysis have proved the formation of the calcium deficient hydroxyapatite and B-type CHA with the Ca/P ratio in the ranges 1.62–1.87. In vitro studies have showed the increased bioactivity of the samples, synthesized under the influence of physical factors as compared to the standard ones. The samples of both groups, synthesized under the influence of 600 W MW, have shown the greatest stability in biological environment. In vivo tests confirm that obtained under US and MW radiations hydroxyapatite-based biomaterials are biocompatible, non-toxic and exhibit osteoconductive properties. The usage of US and MW radiations can significantly shorten the time (up to 5–20 min) of obtaining of calcium deficient hydroxyapatite and B-type CHA in nanopowder form, close in structure and composition to the biological hydroxyapatite.     

Effect of Oat β-Glucan on the Rheological Characteristics and Microstructure of Set-Type Yogurt

The oat β-glucan (OG) was added into set-type yogurt as a functional ingredient, in order to evaluate effects on the rheological characteristics and microstructure of set-type yogurt. When the OG concentration increased from 0 to 0.3%, the WHC gradually increased. At 0.3% OG, the set-type yogurt had the highest WHC of 94.67%. Additionally, the WHC continuously decreased, reaching the lowest WHC (about 80%) at 0.5% OG. When 0.3% OG was added, the highest score of sensory evaluation was about 85. The rheological result showed that the fermentation process went through the changes as follows: solid → liquid → solid → liquid. The addition of 0.3% OG decreased the fermentation time of set-type yogurt by about 16 min, making yogurt more inclined to be liquid. The acidity of set-type yogurt with OG was slightly higher. The result of microstructure showed that the addition of OG destroyed the three-dimensional network structure of yogurt, and some spherical aggregate particles could be clearly observed at 0.3% OG. Overall, this study provided a theoretical basis for the application of OG in set-type yogurt.     

Thermal stability of the phase composition,structure, and stressed state of ion-plasma condensates in the Zr-Ti-Si-N system

The results of studying the effect of high-tempera ture annealing in vacuum and in air on the phase composition, structure, and stressed state of ion-plasma condensates in the Zr-Ti-Si-N system are reported. In going from air annealing to vacuum annealing, the amount of active oxygen atoms decreases and the phase composition of the condensate remains stable to 1000°C or higher. A change in the crystal phase composition shows up, for the first place, in the crystallization of silicon nitride with the intense formation of hexagonal β-Si₃N₄ crystallites and also in the feeble formation of ZrO₂ dioxide. The latter process does not lead to the decomposition of the (Zr, Ti)N solid solution: it merely increases the partial concentration of the titanium component.     

基于柔性双(甲基苯并咪唑)和羧酸配体的Cd(Ⅱ)/Co(Ⅱ)/Zn(Ⅱ)配合物的合成和表征

通过水热或溶剂热合成的方法制备了3个Cd（Ⅱ）/Co（Ⅱ）/Zn（Ⅱ）配位聚合物[Cd（hbmb）_0.5（pta）]_n（1），[Co（hbmb）（1，4-bdc）]_n（2）和{[Zn₂（hbmb）_1.5（bptc）（H₂O）]·0.5hbmb·3H₂O}_n（3）（hbmb=1，1''-（1，6-己烷）双-（2-甲基苯并咪唑），H₂pta=邻羧基苯乙酸，1，4-H₂bdc=1，4-苯二乙酸，H₄bptc=3，3''，4，4''-二苯甲酮四羧酸））。单晶结构解析表明配合物1是一个4-连接的二维平面网络，拓扑符号为（4⁴·6²）。配合物2是一个4-连接的二维褶皱网络，拓扑符号为（4²·6）（4²·6³·8）。配合物3是一个（3，4，4）-连接的三重穿插网络，拓扑符号为（4²·6²·8²）（4·6²）（4·6⁴·8）。其中配合物1属于单斜晶系，空间群为P2₁/c，a=0.758 32（15） nm，b=1.452 8（3） nm，c=1.911 3（5） nm，β=112.26（3）°，Z=4；配合物2属于单斜晶系，空间群为P2₁/n，a=1.090 8（2） nm，b=1.873 1（4） nm，c=1.301 9（3） nm，β=91.09（3）°，Z=4；配合物3属于三斜晶系，空间群为P1，a=1.119 6（2） nm，b=1.481 2（3） nm，c=1.926 6（4） nm，α=89.72（3）°，β=87.65（3）°，γ=68.28（3）°，Z=2。