Highly Reactive Peroxide Species Promoted Soot Oxidation over an Ordered Macroporous Ce0.8Zr0.2O2 Integrated Catalyzed Diesel Particulate Filter.

Particulate matter, represented by soot particles, poses a significant global environmental threat, necessitating efficient control technology. Here, we innovatively designed and elaborately fabricated ordered hierarchical macroporous catalysts of Ce0.8Zr0.2O2 (OM CZO) integrated on a catalyzed diesel particulate filter (CDPF) using the self-assembly method. An oxygen-vacancy-enriched ordered macroporous Ce0.8Zr0.2O2 catalyst (VO-OM CZO) integrated CDPF was synthesized by subsequent NaBH4 reduction. The VO-OM CZO integrated CDPF exhibited a markedly enhanced soot oxidation activity compared to OM CZO and powder CZO coated CDPFs (T50: 430 vs 490 and 545 °C, respectively). The well-defined OM structure of the VO-OM CZO catalysts effectively improves the contact efficiency between soot and the catalysts. Meanwhile, oxygen vacancies trigger the formation of a large amount of highly reactive peroxide species (O22-) from molecular oxygen (O2) through electron abstraction from the three adjacent Ce3+ (3Ce3+ + Vö + O2 → 3Ce4+ + O22-), contributing to the efficient soot oxidation. This work demonstrates the fabrication of the ordered macroporous CZO integrated CDPF and reveals the importance of structure and surface engineering in soot oxidation, which sheds light on the design of highly efficient PM capture and removal devices.

Oxygen Vacancies and Lewis Acid Sites Synergistically Promoted Catalytic Methane Combustion over Perovskite Oxides.

An in-depth understanding of the surface properties-activity relationship could provide a fundamental guidance for the design of highly efficient perovskite-based catalysts for the control of anthropogenic methane emission. Herein, both oxygen vacancies and Con+ Lewis acid sites were purposely introduced on ordered macroporous La0.8Sr0.2CoO3 monolithic catalysts by one-step reduction and selective etching in oxalic acid, and their synergistic effect on methane combustion was investigated. Combined with experimental and theoretical investigations, we revealed that the positively charged Con+ Lewis acid sites and single-electron-trapped oxygen vacancies (Vo·) formed an active pair, which enabled an effective localized electron cloud shift from Vo· to Con+. The characteristic electronic effect modulates surface electronic properties and coordination structures, thus resulting in superior oxygen activation capacity, lattice oxygen mobility, and reducibility, as well as favorable CH4 interaction and oxidation. Our work not only gives insights into surface properties-activity relationships on perovskite for hydrocarbon combustion but also sheds substantial light on future environmental catalyst design and modulation for hydrocarbon pollutants elimination.

[Suprapubis-assisted umbilical laparoendoscopic mini-dual-site surgery for varicocele: a report of 80 cases].

OBJECTIVE: To study the safety, effectiveness and feasibility of suprapubis-assisted umbilical laparoendoscopic mini-dual-site surgery (SAU-LEMDS) in the treatment of varicocele. METHODS: This study included 80 varicocele patients aged 24 - 44 (mean 28.5 +/- 2.6) years, 25 cases of grade I, 45 cases of grade II and 10 cases of grade III, 58 cases in the left side, 6 in the right and 16 in both sides, and all with asthenospermia. The patients were treated by SAU-LEMDS under subarachnoid anesthesia combined with general anesthesia in a supine position with a head-down-feet-up slope of 15 degrees. Two 5 mm trocars were inserted bilaterally at the umbilical edge, one with a 5 mm 30 degrees laparoscope placed in it, and another into the abdominal cavity below the pubic hairline with a 5 mm laparoendoscopic clipper placed in it. The operation procedure was similar to that of standard laparoscopic ligation of spermatic veins, with reservation of the spermatic artery and double-ligation of spermatic veins. And the procedure was repeated for the contralateral lesion in the bilateral cases. Postoperative follow-up was conducted for the incidences of orchiatrophy and testicular hydrocele and changes of seminal parameters. RESULTS: All the operations were successful, with the mean operation time of (10 +/- 5.0) min (range 8 to 25 min) for the unilateral cases and (18 +/- 6.5) min (range 15 to 30 min) for the bilateral cases, the mean blood loss of (1.5 +/- 0.5) ml (range 1 to 2 ml), and the mean postoperative hospital stay of (2 +/- 0.5) d (range 1.5 to 3 d). The patients were followed up for 6 -24 (12 +/- 2.5) months, which showed significant improvement in sperm motility as compared with the baseline ([28.53 +/- 5.21] vs [19.62 +/- 3.56]%, P < 0.05), with 28 cases (35.0%) restored to normal. Recurrence was found in 4 cases (5.0%). Testicular hydrocele occurred in 7 cases (8.75%), but orchiatrophy in none. The scars in the umbilicus and suprapubis were invisible because of the wrinkles and pubic hair. CONCLUSION: SAU-LEMDS is safe, effective and feasible for the treatment of varicocele. It is superior to umbilical laparoendoscopic single-site surgery (U-LESS) for its less invasiveness, simpler operation, and better cosmetic appearance.

Synthesis of Nano-Structured Conjugated Polymers with Multiple Micro-/Meso-Pores by the Post-Crosslinking of End-Functionalized Hyperbranched Conjugated Polymers.

A nano-structured conjugated polymer with multiple micro-/meso-pores was synthesized by post-crosslinking of an end-functionalized hyperbranched conjugated prepolymer. Firstly, an AB2 monomer 3-((3,5-dibromo-4-(octyloxy)phenyl)ethynyl)-6-ethynyl-9-octyl-9H-carbazole (PECz) was synthesized and polymerized by Sonogashira reaction to give the -Br end-functionalized hyperbranched conjugated prepolymer hb-PPECz. The photophysical and electrochemical properties of hb-PPECz were investigated. The λmax of absorption and emission of hb-PPECz in tetrahydrofuran (THF) solution was 313 and 483 nm, respectively. The optical energy bandgap, highest occupied molecular orbital (HOMO), and lowest unoccupied molecular orbital (LUMO) energy levels of hb-PPECz were 2.98, -5.81, and -2.83 eV, respectively. Then, the prepolymer hb-PPECz was post-crosslinked by Heck reaction with divinylbenzene to give the porous conjugated polymer c-PPECz. The effects of hb-PPECz concentration and added dispersant polyvinylpyrrolidone (PVP K-30) on the morphology and porosity of c-PPECz were investigated. The resulting c-PPECzs showed multiple porous structures mainly constructed by micropores and mesopores. Under a higher hb-PPECz concentration (4 wt/v%), a bulky gel product was obtained. Under lower hb-PPECz concentrations (0.6 wt/v%~2 wt/v%), the resulting c-PPECzs were mainly composed of nano-sized particles. Nearly spheric nanoparticles (200~300 nm) (c-PPECz-5) were obtained under the concentration of 1 wt/v% in the presence of PVP (10 wt% of hb-PPECz). The Brunauer-Emmett-Teller (BET) surface area, pore volume, average pore size, and percentage of pore size below 10 nm of c-PPECz-5 were 10.7781 m2·g-1, 0.0108 cm3·g-1, 4.0081 nm, and 94.47%, respectively.

Suprapubic-assisted umbilical laparoendoscopic mini-dual-site surgery in the treatment of simple kidney cyst: report of 26 cases.

This study was designed to evaluate the safety and efficacy of suprapubic-assisted umbilical laparoendoscopic mini-dual-site surgery (SAU-LEMDS) with satisfied cosmetic outcome in minimal size of surgical incision for the treatment of simple kidney cyst at large size. Twenty-six consecutive patients (16 male and 10 female), aged 48.5 ± 4.1 years (range: 18 to 70 years), were enrolled in this study. All cases had simple kidney cysts including 18 cases on the left side and 8 cases on the right, with a mean cyst maximum diameter of 7.5 ± 0.8 cm. Under general anesthesia, the patients were placed in flank position with affected side elevated by 70°. Two trocars (5.5 mm in diameter) were inserted via the umbilical port. The third trocar was inserted into abdominal cavity above the pubic hairline for the placement of a 5-mm 30° laparoscope. The surgery procedures were successfully performed in the same manner as standard laparoscope-assisted kidney cyst decortication in all cases. The specimens were obtained through either of two umbilical ports without additional enlarge incisions. The mean operation time was 30 ± 8.2 min and the mean blood loss was 10.3 ± 2.1 ml. The duration of hospitalization was 4.2 ± 0.9 days, and the mean follow-up was two months (range: 1 to 3 months). Postoperatively, surgical wounds were small and healed well and cosmetic outcomes were satisfactory. No recurrent kidney cysts were found during follow up. SAU-LEMDS appears to be a feasible, safe and effective surgical option for simple kidney cyst, which not only leads to better cosmetic effects, but also decreases the complexity of umbilical laparoendoscopic single site surgery (U-LESS).