花崗岩質土壌中のフッ化物の反応性輸送および吸脱着プロセス

学位の種別: 課程博士審査委員会委員 : （主査）東京大学教授 徳永 朋祥, 東京大学准教授 吉永 淳, 東京大学准教授 大友 順一郎, 東京大学准教授 布浦 鉄兵, 東京大学准教授 ドドビバ ジョルジ, 東京大学講師 愛知 正温University of Tokyo(東京大学

Surface Complexation Modeling of Fluoride Adsorption by Soil and the Role of Dissolved Aluminum on Adsorption

The adsorption processes of F on a natural soil as a function of varying pH and F concentration were evaluated by applying a surface complexation model (SCM) based on a single surface functional group with monodentate binding sites. A granitic soil from Tsukuba, Japan, was chosen as an example, and the SCM was developed to explain the pH dependency of F sorption isotherms on the soil. Four possible surface complexation reactions were postulated with and without including dissolved Al. Optimized constants for F surface complexation, and those for protonation and deprotonation, were used for the simulations. The SCM including dissolved Al and the adsorption of Al–F complex can simulate the experimental results, the decreasing trend of F adsorption with the increase in pH, quite successfully. Also, including dissolved Al and the adsorption of Al–F complex to the model explained the change in solution pH after F adsorption. Therefore, incorporation of dissolved Al and Al–F complex in model calculations of a soil–F system is an important improvement to predict F concentrations of soil solutions

Leaf Traits and Antioxidant Defense for Drought Tolerance During Early Growth Stage in Some Popular Traditional Rice Landraces from Koraput, India

Three popular traditional rice landraces, namely Kalajeera, Machakanta and Haladichudi, from Koraput, India were used to analyse the leaf traits and antioxidant defence for drought tolerance. When rice plants were exposed to different levels of drought stress by varying concentrations of polyethylene glycol (PEG) 6000, seed germination and growth parameters were significantly declined in all the rice landraces compared to the control. Drought stress also altered the leaf phenotypic traits based on chlorophyll fluorescence parameters and chlorophyll index, with more significant differences in susceptible variety IR64 than in traditional landraces. Furthermore, activities of antioxidative enzymes and proline and protein contents overtly increased under drought stress. The traditional rice landraces showed higher relative ratios for different parameters compared to the susceptible variety IR64. Taken together, the traditional landraces had superior leaf physiological efficiency compared to the susceptible and tolerant check varieties under drought stress

Investigation of pharmacokinetic drug interaction between clesacostat and DGAT2 inhibitor ervogastat in healthy adult participants

Abstract Co‐administration of clesacostat (acetyl‐CoA carboxylase inhibitor, PF‐05221304) and ervogastat (diacylglycerol O‐acyltransferase inhibitor, PF‐06865571) in laboratory models improved non‐alcoholic fatty liver disease (NAFLD)/non‐alcoholic steatohepatitis (NASH) end points and mitigated clesacostat‐induced elevations in circulating triglycerides. Clesacostat is cleared via organic anion‐transporting polypeptide‐mediated hepatic uptake and cytochrome P450 family 3A (CYP3A); in vitro clesacostat is identified as a potential CYP3A time‐dependent inactivator. In vitro ervogastat is identified as a substrate and potential inducer of CYP3A. Prior to longer‐term efficacy trials in participants with NAFLD, safety and pharmacokinetics (PK) were evaluated in a phase I, non‐randomized, open‐label, fixed‐sequence trial in healthy participants. In Cohort 1, participants (n = 7) received clesacostat 15 mg twice daily (b.i.d.) alone (Days 1–7) and co‐administered with ervogastat 300 mg b.i.d. (Days 8–14). Mean systemic clesacostat exposures, when co‐administered with ervogastat, decreased by 12% and 19%, based on maximum plasma drug concentration and area under the plasma drug concentration–time curve during the dosing interval, respectively. In Cohort 2, participants (n = 9) received ervogastat 300 mg b.i.d. alone (Days 1–7) and co‐administered with clesacostat 15 mg b.i.d. (Days 8–14). There were no meaningful differences in systemic ervogastat exposures when administered alone or with clesacostat. Clesacostat 15 mg b.i.d. and ervogastat 300 mg b.i.d. co‐administration was overall safe and well tolerated in healthy participants. Cumulative safety and no clinically meaningful PK drug interactions observed in this study supported co‐administration of these two novel agents in additional studies exploring efficacy and safety in the management of NAFLD