Application of waste derived magnetic acid-base bifunctional CoFe/biochar/CaO as an efficient catalyst for biodiesel production from waste cooking oil.

The loss of active components, weak acid resistance, and low recover efficiency of common Ca-based catalysts limited its further development and application. In this study, to effectively produce biodiesel from waste cooking oil (WCO), a green and recyclable magnetic acid-base bifunctional CoFe/biochar/CaO catalyst was prepared from sargassum and river snail shell waste via hydrothermal method. The catalysts' structure and properties were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), CO2/NH3 temperature programmed desorption (CO2/NH3 TPD), etc., The prepared catalyst mainly consisted of the carbon skeleton, CoFe alloy, and CaO. CoFe alloy provided catalyst's ferromagnetism for magnetic separation as well as acid sites for transesterification of WCO. Ca and other metal species with nanoscale (∼5.64 nm) were dispersively anchored on sargassum biochar surface, thereby leading to good catalytic activity (99.21% biodiesel yield) and stability (91.70% biodiesel yield after the 5th cycle). In addition, response surface methodology-Box-Behnken design (RSM-BBD) revealed the optimal operational conditions were 16:1 methanol/oil molar ratio, 3 wt% catalyst dosage, 73 °C for 157 min. The maximum biodiesel yield predicted value was 98.29% and the experimental value was 99.21%, indicating good satisfaction of the established model. Moreover, the quality of WCO biodiesel met the ASTM D6751 standards. This study benefits magnetic waste-derived acid-base bifunctional catalysts for the disposal of WCO towards sustainable biodiesel production.

Five-year follow-up results of a randomized controlled trial comparing bipolar plasmakinetic and monopolar transurethral resection of the prostate.

PURPOSE: To report the 5-year follow-up results of a randomized controlled trial comparing bipolar transurethral resection of the prostate (TURP) with standard monopolar TURP for the treatment of benign prostatic obstruction (BPO). MATERIALS AND METHODS: A total of 220 patients were randomized to bipolar plasmakinetic TURP (PK-TURP) or monopolar TURP (M-TURP). Catheterization time was the primary endpoint of this study. Secondary outcomes included operation time, hospital stay, as well as decline in postoperative serum sodium and hemoglobin levels. All patients were assessed preoperatively and followed-up at 1, 6, 12, 24, 36, 48, and 60 months postoperatively. Parameters assessed included quality of life, transrectal ultrasound, serum prostate-specific antigen level, postvoid residual urine volume, maximum urinary flow rates (Q(max)), and International Prostate Symptom Score. Patient baseline characteristics, perioperative data including complications, and postoperative outcomes were compared. Complication occurrence was graded according to the modified Clavien classification system. RESULTS: PK-TURP was significantly superior to M-TURP in terms of operation time, intraoperative irrigation volume, resected tissue weight, decreases in hemoglobin and sodium, postoperative irrigation volume and time, catheterization time, and hospital stay. At 5 years postoperatively, efficacy was comparable between arms. No differences were detected in safety outcomes except that the clot retention rate was significantly greater after M-TURP. CONCLUSION: Our results indicate that PK-TURP is equally as effective in the treatment of BPO, but has a more favorable safety profile in comparison to M-TURP. The clinical efficacy of PK-TURP is long-lasting and comparable with M-TURP.

Bipolar plasmakinetic transurethral resection of prostate in 132 consecutive patients with large gland: three-year follow-up results.

OBJECTIVE: To assess the safety, efficacy, and medium-term durability of bipolar plasmakinetic transurethral resection of the prostate (PK-TURP) for the treatment of bladder outlet obstruction due to benign prostatic hyperplasia in a prospective study. METHODS: From March 2007 to May 2008, 132 consecutive patients underwent PK-TURP at our institution. All patients were assessed perioperatively and followed up at 1, 3, 6, 12, 18, 24, and 36 months postoperatively. The parameters included the International Prostate Symptom Score, quality of life scores, maximal urinary flow rates, transrectal ultrasonography, postvoid residual urine volume, and serum prostate-specific antigen level. RESULTS: The mean patient age was 64.55±4.03 years. The prostate volume was 79.66±12.36 g. The operative time was 78.83±17.41 minutes, and the resected weight was 58.12±7.29 g. The catheterization time was 69.00±17.99 hours, and the hospital stay was 117.00±17.99 hours. The decrease in hemoglobin and sodium was 1.55±0.48 g/dL and 1.57±0.38 mmol/L, respectively. A significant improvement occurred in the maximal urinary flow rate (22.34±3.1 mL/s), International Prostate Symptom Score (2.90±1.60), and quality of life (1.12±0.60) at the 3-year follow-up compared with baseline (P<.001). Of the 132 patients, 6 (4.5%) required reoperation. CONCLUSION: PK-TURP represents an effective surgical intervention for the treatment of bladder outlet obstruction for large prostates. Furthermore, the functional results at 3 years demonstrated durability. Therefore, the PK-TURP technique could play an important role in the surgical treatment of patients with symptomatic benign prostatic hyperplasia with a large prostate gland.