Enhancement of apatite formation on Ti-50Zr alloy in simulated body environment

Ti-50Zr alloy is 2.5 times as strong as pure Ti and has a lower Young's modulus, making it a useful material for repairing bone and teeth. However, Ti-50Zr alloy has a limited ability to bond with bone in vivo. Under biological conditions, apatite formation at the surface of a Ti or alloy implant is necessary for its bonding with bone. Various approaches to surface modification have been proposed to impart bone-bonding ability to Ti-50Zr alloy; however, there remains a need for further improvements to the alloy's apatite-forming ability. Hence, in this study, we compared apatite formation at the surface of alloy substrates in simulated body fluid, after various surface treatments. Treatment with 5 M NaOH followed by 1 M CaCl₂ was the most effective procedure, whereas a sample subjected to a hot water post-treatment formed less apatite. Notably, no apatite formed on samples treated with 10 M NaOH.

Physiological and Transcriptome Analyses of CaCl2 Treatment to Alleviate Chilling Injury in Pineapple

The post-harvest ripening of pineapples can be effectively postponed by refrigerated storage. Nevertheless, internal browning (IB) frequently appears in pineapples after refrigerated storage during the course of the shelf life at room temperature, which is known as chilling injury (CI). In this study, the chilling injury of pineapple fruit was induced by a low temperature (6 °C) and transferred to normal-temperature storage; the best concentration of 50 μmol/L of CaCl₂ was selected by the IB appearance and electrical conductivity. Fruit quality, reactive oxygen species (ROS), antioxidants, and transcription factors were investigated. The physiological data results indicated that pineapples treated with 50 μmol/L of CaCl₂ maintained fruit quality, decreased reactive oxygen species (ROS), and enhanced the antioxidant activity of fruits, alleviating internal browning (IB) symptoms in pineapple fruit. The expressions of related genes were also consistent with the physiological changes by the transcriptome data analysis. In addition, we focused on some related metabolic pathways, including phenylpropanoid biosynthesis, MAPK pathway, plant hormone, plant-pathogen interaction, tricarboxylic acid cycle (TAC), and fatty acid biosynthesis. We performed integrative analyses of transcriptome data combined with a series of physiology and experimental analyses on the internal browning of pineapples, which will be of great significance to extending the shelf life of pineapples through molecular biology in the future.

Amelioration of moisture stress effect by CaCl2 pre-treatment in upland rice

Five varieties of rice viz., Subhadra, Ghanteswari, Sidhant, Jogesh and Khandagiri were grown to study the stress alleviating effect of CaCl₂ at panicle initiation (PI) stage. CaCl₂ (1 %) was given as seed treatment, which ameliorated the adverse effect of drought stress on photosynthesis (Pn), stomatal conductance (Gs), membrane stability index (MSI), leaf moisture retention index (LMRI) and grain weight. Under stress condition Pn, Gs, MSI and LMRI were significantly reduced. All CaCl₂ pre-treatments enhanced yield, and the reduction under moisture stress was only 21.9 % as compared to 62 % in untreated stressed plants. Amongst the varieties Shubadra and Ghanteswari possessed better drought adaptive mechanism than Sidhant, Jogesh and Khandagiri.