Extraction of Uranium in Nitric Media with Novel Asymmetric Tetra-Alkylcarbamide.

The use of tetra-alkylcarbamides as novel ligands: N,N-butyl-N',N'-hexylurea (L1: ABHU), and N,N-butyl-N',N'-pentylurea (L2: ABPU), for the solvent extraction and complexation behaviors of uranium(VI) was synthesized and investigated in this study. The effects of HNO3 and NO3- concentrations in the aqueous phase on the distribution ratio of U(VI) were examined. Under 5 mol/L HNO3 concentration, DU reached 5.02 and 4.94 respectively without third-phase formation. During the extraction, slope measurements and IR spectral analysis revealed that the U(VI) complexes are a form of UO2(NO3)2·2L for both ligands. In addition, thermodynamic studies showed that the uranium extraction reaction was a spontaneous exothermic reaction. The deep structural analysis of the complexes was realized with DFT calculation. The bond length, bond properties, and topology of the complexes were discussed in detail to analyze the extraction behavior. This study enriches the coordination chemistry of U(VI) by tetra-alkylcarbamides, which may offer new clues for the design and synthesis of novel ligands for the separation, enrichment, and recovery of uranium in the nuclear fuel cycle.

Molecular Self-Assembly of Oxygen Deep-Doped Ultrathin C3N4 with a Built-In Electric Field for Efficient Photocatalytic H2 Evolution.

Heteroatom-doped carbon nitride (C3N4) with a built-in electric field can reinforce the carrier separation; however, the stability will be greatly reduced due to the loss of surface-doped atoms. Here, molecule self-assembly, as a facile bottom-up approach, is explored for the synthesis and oxygen doping of C3N4. The obtained C3N4 presents a porous and ultrathin structure and oxygen deep-doping, which generate abundant nitrogen vacancies and a stable built-in electric field. Toward photocatalytic hydrogen evolution, the ultrathin and oxygen deep-doped C3N4 exhibits a 3.5-fold higher activity than bulk C3N4 under simulated sunlight, and 3.6 times higher stability than the oxygen surface-doped counterpart within five cycles. Femtosecond transient absorption spectroscopy indicates the improved carrier separation, and density functional theory (DFT) calculation reveals the promoted H2O adsorption and activation under the built-in electric field, which contribute to the excellent photocatalytic performance of oxygen deep-doped ultrathin C3N4.

Perioperative and post-hospital whole-course nutrition management in patients with pancreatoduodenectomy - a single-center prospective randomized controlled trial.

OBJECTIVE: Whole-course nutrition management (WNM) has been proven to improve outcomes and reduce complications. We conducted this randomized controlled trial to validate its effectiveness in patients undergoing pancreatoduodenectomy (PD). METHODS: From 1 December 2020, to 30 November 2023, this single-center randomized clinical trial was conducted at the Department of Hepatobiliopancreatic Surgery in a major hospital in Beijing, China. Participants who were undergoing PD were enrolled and randomly allocated to either the WNM group or the control group. The primary outcome was the incidence of postoperative complications. Subgroup analysis in patients who were at nutritional risk was performed. Finally, a 6-month follow-up was conducted and the economic benefit was evaluated using an incremental cost-effectiveness ratio (ICER). RESULTS: A total of 84 patients were randomly assigned (1:1) into the WNM group and the control group. The incidences of total complications (47.6% vs. 69.0%, P =0.046), total infections (14.3% vs. 33.3%, P =0.040), and abdominal infection (11.9% vs. 31.0%, P =0.033) were significantly lower in the WNM group. In the subgroup analysis of patients at nutritional risk, 66 cases were included (35 cases in the WNM group and 31 cases in the control group). The rate of abdominal infection (11.4% vs. 32.3%, P =0.039) and postoperative length of stay (23.1±10.3 vs. 30.4±17.2, P =0.046) were statistically different between the two subgroups. In the 6-month follow-up, more patients reached the energy target in the WNM group (97.0% vs. 79.4%, P =0.049) and got a higher daily energy intake (1761.3±339.5 vs. 1599.6±321.5, P =0.045). The ICER suggested that WNM saved 31 511 Chinese Yuan (CNY) while reducing the rate of total infections by 1% in the intention-to-treat (ITT) population and saved 117 490 CNY in patients at nutritional risk, while WNM saved 31 511 CNY while reducing the rate of abdominal infections by 1% in the ITT population and saved 101 359 CNY in patients at nutritional risk. CONCLUSION: In this trial, whole-course nutrition management was associated with fewer total postoperative complications, total and abdominal infections, and was cost-effective, especially in patients at nutritional risk. It seems to be a favorable strategy for patients undergoing PD.

Selective Separation of Zr(IV) from Simulated High-Level Liquid Waste by Mesoporous Silica.

The efficient separation of Zr(IV) ions from strong acidic and radioactive solutions is a significant challenge, especially in the context of the aqueous reprocessing of nuclear fuels. The complexity of such solutions, which are often characterized by high acidity and the presence of radioactive elements, poses formidable challenges for separation processes. Herein, several mesoporous silicas (HMS, MCM-41, KIT-6, and SiO2-70 Å) with excellent acid and radiation resistance properties were employed as sorbents to remove Zr(IV) ions from simulated high-level liquid waste. The batch experiments were designed to investigate the influence of adsorption time, HNO3 concentration, initial Zr(IV) concentration, adsorbent dosage, and temperature on the adsorption behavior of Zr(IV). The results indicate that the adsorption equilibrium time of mesoporous silica materials was approximately 8 h, and all the adsorption processes followed the pseudo-second-order kinetics equation. The isotherms of Zr(IV) adsorption by KIT-6 exhibited good agreement with the Langmuir model, while the Freundlich model could be utilized to fit the adsorption on HMS, MCM-41, and SiO2-70 Å. The adsorption capacity of MCM-41 for Zr(IV) in 3 mol/L HNO3 was 54.91 mg/g, which is three times the adsorption capacity reported for commercial silica gel (17.91 mg/g). The thermodynamic parameters indicate that the adsorption processes for zirconium are endothermic reactions. Furthermore, the mesoporous silicas exhibited a pronounced selectivity in the adsorption of Zr(IV) within a simulated high-level liquid waste containing 10 co-existing cations (3 mol/L HNO3). This suggests that mesoporous silicas have great potential for Zr(IV) removal in actual radioactive liquids with high acidity during spent fuel reprocessing.

Relationship between preoperative malnutrition, frailty, sarcopenia, body composition, and anthropometry in elderly patients undergoing major pancreatic and biliary surgery.

Objective: To analyze the correlation between preoperative nutritional status, frailty, sarcopenia, body composition, and anthropometry in geriatric inpatients undergoing major pancreatic and biliary surgery. Methods: This is a cross-sectional study of the database from December 2020 to September 2022 in the department of hepatopancreatobiliary surgery, Beijing Hospital. Basal data, anthropometry, and body composition were recorded. NRS 2002, GLIM, FFP 2001, and AWGS 2019 criteria were performed. The incidence, overlap, and correlation of malnutrition, frailty, sarcopenia, and other nutrition-related variables were investigated. Group comparisons were implemented by stratification of age and malignancy. The present study adhered to the STROBE guidelines for cross-sectional study. Results: A total of 140 consecutive cases were included. The prevalence of nutritional risk, malnutrition, frailty, and sarcopenia was 70.0, 67.1, 20.7, and 36.4%, respectively. The overlaps of malnutrition with sarcopenia, malnutrition with frailty, and sarcopenia with frailty were 36.4, 19.3, and 15.0%. There is a positive correlation between every two of the four diagnostic tools, and all six p-values were below 0.002. Albumin, prealbumin, CC, GS, 6MTW, ASMI, and FFMI showed a significantly negative correlation with the diagnoses of the four tools. Participants with frailty or sarcopenia were significantly more likely to suffer from malnutrition than their control groups with a 5.037 and 3.267 times higher risk, respectively (for frailty, 95% CI: 1.715-14.794, p = 0.003 and for sarcopenia, 95% CI: 2.151-4.963, p<0.001). Summarizing from stratification analysis, most body composition and function variables were worsen in the ≥70 years group than in the younger group, and malignant patients tended to experience more intake reduction and weight loss than the benign group, which affected the nutrition diagnosis. Conclusion: Elderly inpatients undergoing major pancreatic and biliary surgery possessed high prevalence and overlap rates of malnutrition, frailty, and sarcopenia. Body composition and function deteriorated obviously with aging.