Synthetic Mechanism Discovery of Monophase Cuprous Oxide for Record High Photoelectrochemical Conversion of CO₂ to Methanol in Water

Precise control of the oxidation state of transition-metal oxides, such as copper, is important for high selectivity of CO₂ reduction in an aqueous condition to compete with the reduction of water. The phase of copper oxide nanofibers was controlled by predictive synthesis, which controls the nanoscale gas–solid reaction by considering thermodynamics and kinetics. The driving force of the phase transformation between the different oxidation states of copper oxide is calculated by comparing the Gibbs free energy of each of the oxidation states. From the calculation, the kinetically processable window for the fabrication of Cu₂O in which monophase Cu₂O can be fabricated in a reasonable reaction time scale is discovered. Herein, we report the monophase Cu₂O nanofiber photocathode, which photoelectrochemically converted CO₂ into methanol with over 90% selectivity in an aqueous electrolyte, and a hierarchical structure is developed to optimize the photoactivity and stability of the electrode. Our work suggests a rational design of the calcination strategy for precisely controlling the oxidation states of transition metals that can be applied to various applications in which the phase of the materials plays an important role

Impact of Intratumoral Expression Levels of Fluoropyrimidine-Metabolizing Enzymes on Treatment Outcomes of Adjuvant S-1 Therapy in Gastric Cancer

<div><p>We analyzed the expression levels of fluoropyrimidine-metabolizing enzymes (thymidylate synthase [TS], dihydropyrimidine dehydrogenase [DPD], thymidine phosphorylase [TP] and orotate phosphoribosyltransferase [OPRT]) to identify potential biomarkers related to treatment outcomes in gastric cancer (GC) patients receiving adjuvant S-1 chemotherapy. In this study, 184 patients who received curative gastrectomy (D2 lymph node dissection) and adjuvant S-1 were included. Immunohistochemistry and quantitative reverse transcription polymerase chain reaction were performed to measure the protein and mRNA levels of TS, DPD, TP, and OPRT in tumor tissue. In univariate analysis, low intratumoral DPD protein expression was related to poorer 5-year disease-free survival (DFS; 78% vs. 88%; P = 0.068). Low intratumoral DPD mRNA expression (1st [lowest] quartile) was also related to poorer DFS (69% vs. 90%; P < 0.001) compared to high intratumoral DPD expression (2nd to 4th quartiles). In multivariate analyses, low intratumoral DPD protein or mRNA expression was related to worse DFS (P < 0.05), irrespective of other clinical variables. TS, TP, and OPRT expression levels were not related to treatment outcomes. Severe non-hematologic toxicities (grade ≥ 3) had a trend towards more frequent development in patients with low intratumoral DPD mRNA expression (29% vs. 16%; P = 0.068). In conclusion, GC patients with high intratumoral DPD expression did not have inferior outcome following adjuvant S-1 therapy compared with those with low DPD expression. Instead, low intratumoral DPD expression was related to poor DFS.</p></div

The incidence of VTE according to clinical parameters.

*<p>Fisher's exact test, ^†linear-by-linear association.</p>‡<p>Subtotal gastrectomy was conducted in 271 patients and proximal gastrectomy in 11 patients.</p><p>Abbreviations: VTE, venous thromboembolism; BMI, body mass index; WBC, white bleed cell.</p

Flow of patients in this study.

<p>Flow of patients in this study.</p

Characteristics of patients who developed VTE during postoperative periods.

<p>Abbreviations: VTE, venous thromboembolism; DVT, deep vein thrombosis; PE, pulmonary embolism; LMWH, low molecular weight heparin.</p

Disease-free survival (A) in all patients (N = 184) and (B) according to stages.

<p>Disease-free survival (A) in all patients (N = 184) and (B) according to stages.</p

Patient characteristics.

<p>Abbreviations: SD, standard deviation.</p>*<p>chi-square test, ^†t-test.</p><p>In multivariate analysis using a logistic regression model, the clinical parameters with P<0.20 in univariate analyses (age, number of comorbidities, WBC counts, hemoglobin level, surgical procedure [laparoscopic vs. open surgery] and stage) were included. A backward stepwise conditional logistic regression was used with P = 0.10 as the entry and P = 0.10 as the removal criteria.</p><p>Abbreviations: OR, odds ratio; CI, confidence interval; WBC, white blood cell.</p

Impact of the expression levels of intratumoral DPD ((A) DPD protein expression and (B) DPD mRNA expression) on disease-free survival.

<p>(A) Clinical variables that had P < 0.10 in univariate analyses on DFS (age [< 60 years vs. 60–69 years vs. ≥ 70 years], surgical method [laparoscopic vs. open], lymphatic invasion [no vs. yes], venous invasion [no vs. yes], stage [IB/II vs. III], DPD IHC score [≥ 10 vs. < 10] and TP IHC score [0 vs. > 0]) were included in this multivariate analysis using a Cox proportional hazards model. A backward stepwise conditional regression was used with P = 0.10 as the entry and P = 0.10 as the removal criteria. Abbreviations: IHC, immunohistochemistry; DPD, dihydropyrimidine dehydrogenase; TP, thymidine phosphorylase.</p><p>(B) Clinical variables that had P < 0.10 in univariate analyses on DFS (age [< 60 years vs. 60–69 years vs. ≥ 70 years), surgical method [laparoscopic vs. open], lymphatic invasion [no vs. yes], venous invasion [no vs. yes], stage [IB/II vs. III]) and mRNA expression levels of DPD gene were included in this multivariate analysis using a Cox proportional hazards model. A backward stepwise conditional regression was used with P = 0.10 as the entry and P = 0.10 as the removal criteria.</p><p>Impact of the expression levels of intratumoral DPD ((A) DPD protein expression and (B) DPD mRNA expression) on disease-free survival.</p