It is a challenge to make thorough but efficient experimental designs for the coupled mineral dissolution and precipitation studies in a multi-mineral system, because it is difficult to speculate the best experimental...It is a challenge to make thorough but efficient experimental designs for the coupled mineral dissolution and precipitation studies in a multi-mineral system, because it is difficult to speculate the best experimental duration, optimal sampling schedule, effects of different experimental conditions, and how to maximize the experimental outputs prior to the actual experiments. Geochemical modeling is an efficient and effective tool to assist the experimental design by virtually running all scenarios of interest for the studied system and predicting the experimental outcomes. Here we demonstrated an example of geochemical modeling assisted experimental design of coupled labradorite dissolution and calcite and clayey mineral precipitation using multiple isotope tracers. In this study, labradorite(plagioclase) was chosen as the reactant because it is both a major component and one of the most reactive minerals in basalt. Following our isotope doping studies of single minerals in the last ten years, initial solutions in the simulations were doped withmultiple isotopes(e.g., Ca and Si). Geochemical modeling results show that the use of isotope tracers gives us orders of magnitude more sensitivity than the conventional method based on concentrations and allows us to decouple dissolution and precipitation reactions at near-equilibrium condition. The simulations suggest that the precise unidirectional dissolution rates can inform us which rate laws plagioclase dissolution has followed. Calcite precipitation occurred at near-equilibrium and the multiple isotope tracer experiments would provide near-equilibrium precipitation rates, which was a challenge for the conventional concentration-based experiments. In addition, whether the precipitation of clayey phases is the rate-limiting step in some multi-mineral systems will be revealed. Overall, the modeling results of multimineral reaction kinetics will improve the understanding of the coupled dissolution–precipitation in the multi-mineral systems and the quality of geochemical modeling prediction of CO_(2) removal and storage efficacy in the basalt systems.展开更多
Objectives:To investigate the role of complete transurethral resection of bladder tumor(TURBT)before radical cystectomy(RC)for organ-confined bladder cancer.Materials and methods:Data of patients who underwent RC in o...Objectives:To investigate the role of complete transurethral resection of bladder tumor(TURBT)before radical cystectomy(RC)for organ-confined bladder cancer.Materials and methods:Data of patients who underwent RC in our center from January 2008 to December 2018 were retrospectively reviewed.Patients with>T2N0M0 disease and positive surgical margins and those who received neoadjuvant/adjuvant chemotherapy or radiotherapy were excluded.Complete TURBT was defined as no visible lesion under endoscopic examination after TURBT or in the bladder specimen after RC.Kaplan-Meier curves and log-rank tests assessed disease-free survival(DFS).Logistic and Cox regression analyses were performed to identify potential predictors.Results:A total of 236 patients were included in this review,including 207 males,with a median age of 61 years.The median tumor size was 3 cm,and a total of 94 patients had identified pathological T2 stage disease.Complete TURBT was correlated with tumor size(p=0.041),histological variants(p=0.026),and down-staging(p<0.001).Tumor size,grade,and histological variants were independent predictors of complete TURBT.During a median follow-up of 42.7 months,30 patients developed disease recurrence.Age and histological variants were independent predictors of DFS(p=0.022 and 0.032,respectively),whereas complete TURBT was not an independent predictor of DFS(p=0.156).Down-staging was not associated with survival outcome.Conclusions:Complete TURBT was correlated with an increased rate of down-staging before RC.It was not associated with better oncologic outcomes for patients with organ-confined bladder cancer.展开更多
基金partially supported by U.S. National Science Foundation grants EAR-2221907partly sponsored by agencies of the United States Government。
文摘It is a challenge to make thorough but efficient experimental designs for the coupled mineral dissolution and precipitation studies in a multi-mineral system, because it is difficult to speculate the best experimental duration, optimal sampling schedule, effects of different experimental conditions, and how to maximize the experimental outputs prior to the actual experiments. Geochemical modeling is an efficient and effective tool to assist the experimental design by virtually running all scenarios of interest for the studied system and predicting the experimental outcomes. Here we demonstrated an example of geochemical modeling assisted experimental design of coupled labradorite dissolution and calcite and clayey mineral precipitation using multiple isotope tracers. In this study, labradorite(plagioclase) was chosen as the reactant because it is both a major component and one of the most reactive minerals in basalt. Following our isotope doping studies of single minerals in the last ten years, initial solutions in the simulations were doped withmultiple isotopes(e.g., Ca and Si). Geochemical modeling results show that the use of isotope tracers gives us orders of magnitude more sensitivity than the conventional method based on concentrations and allows us to decouple dissolution and precipitation reactions at near-equilibrium condition. The simulations suggest that the precise unidirectional dissolution rates can inform us which rate laws plagioclase dissolution has followed. Calcite precipitation occurred at near-equilibrium and the multiple isotope tracer experiments would provide near-equilibrium precipitation rates, which was a challenge for the conventional concentration-based experiments. In addition, whether the precipitation of clayey phases is the rate-limiting step in some multi-mineral systems will be revealed. Overall, the modeling results of multimineral reaction kinetics will improve the understanding of the coupled dissolution–precipitation in the multi-mineral systems and the quality of geochemical modeling prediction of CO_(2) removal and storage efficacy in the basalt systems.
基金supported by the Fundamental Research Fund for Central Universities(grant 20ykpy179)Medical Science Fund of Guangdong Province(A2020139).
文摘Objectives:To investigate the role of complete transurethral resection of bladder tumor(TURBT)before radical cystectomy(RC)for organ-confined bladder cancer.Materials and methods:Data of patients who underwent RC in our center from January 2008 to December 2018 were retrospectively reviewed.Patients with>T2N0M0 disease and positive surgical margins and those who received neoadjuvant/adjuvant chemotherapy or radiotherapy were excluded.Complete TURBT was defined as no visible lesion under endoscopic examination after TURBT or in the bladder specimen after RC.Kaplan-Meier curves and log-rank tests assessed disease-free survival(DFS).Logistic and Cox regression analyses were performed to identify potential predictors.Results:A total of 236 patients were included in this review,including 207 males,with a median age of 61 years.The median tumor size was 3 cm,and a total of 94 patients had identified pathological T2 stage disease.Complete TURBT was correlated with tumor size(p=0.041),histological variants(p=0.026),and down-staging(p<0.001).Tumor size,grade,and histological variants were independent predictors of complete TURBT.During a median follow-up of 42.7 months,30 patients developed disease recurrence.Age and histological variants were independent predictors of DFS(p=0.022 and 0.032,respectively),whereas complete TURBT was not an independent predictor of DFS(p=0.156).Down-staging was not associated with survival outcome.Conclusions:Complete TURBT was correlated with an increased rate of down-staging before RC.It was not associated with better oncologic outcomes for patients with organ-confined bladder cancer.
