Fe Engineering on Ru Nanosheets for Enhanced Hydrogen Evolution in pH-Universal Media.

Fe-modified Ru nanosheets are achieved via preintercalated Al species serving as the self-sacrificial template. Benefiting from the amphoteric feature of Al and strong corrosion of Fe3+ ions, Fe is effectively incorporated into pristine Ru nanosheets. Correspondingly, the surface oxophilicity is improved, promoting the Volmer step. The charge density redistribution weakens hydrogen combination on Ru and thus accelerates the desorption kinetics (Heyrovsky step). Meanwhile, more defective sites are exposed, leading to an enhanced hydrogen production in pH-universal electrolytes.

Identifying the Active Site on Graphene Oxide Nanosheets for Ambient Electrocatalytic Nitrogen Reduction.

Identifying the active sites on graphene oxide (GO) nanosheets is of great importance. In situ electroreduction at different potentials is applied to control the oxygenated groups on GO surfaces. Both experiments and theoretical calculations suggest the C═O group is critical for N2 adsorption and activation, guaranteeing the ambient electrocatalytic N2 reduction.

Activating Graphyne Nanosheet via sp-Hybridized Boron Modulation for Electrochemical Nitrogen Fixation.

Exploring new metal-free catalysts with high activity for nitrogen reduction reaction (NRR) is highly desirable but remains a big challenge. Graphyne (GY) is a typical two-dimensional carbon material with many excellent properties. However, the NRR has rarely been envisaged on a GY-based metal-free catalyst up to now. Density functional theory calculations reveal that although pristine GY is inactive for N2 reduction, boron modulation can endow it with efficient activity toward NRR. Natural bond orbitals analysis, spin/charge density distributions, and free energy change diagrams are performed and discussed. Three boron doping formats including sp2-substituted, sp-substituted, and adsorbed configuration are considered. The obtained data show sp-substitution will induce local moderate spin and charge densities at the boron site on the GY surface, which is convenient for N2 adsorption and activation, and conductive to N-related intermediates formation and transformation. Moreover, the incorporated sp-hybridized boron can provide one empty p orbital and one occupied p orbital around itself, which plays a key role as an electron reservoir to accept electrons from and donate electrons to the adsorbed N-related species, and thus facilitate N2 reduction and ammonia synthesis. Henceforth, it provides more opportunities for preparing GY and other carbon materials as efficient catalysts toward renewable energy conversion and storage.

The Value of 320-Row Multidetector CT Bronchial Arteriography in Recurrent Hemoptysis after Failed Transcatheter Arterial Embolization.

PURPOSE: To retrospectively assess the value of computed tomographic (CT) bronchial arteriography (BA) with 320-row multidetector CT in the management of patients with recurrent hemoptysis immediately after bronchial artery embolization (BAE). MATERIALS AND METHODS: Among 135 consecutive patients treated with BAE between April 2014 and March 2016, recurrent hemoptysis developed in 15, and 10 subsequently underwent multidetector CT. Vascular abnormalities and associated anatomy were evaluated to determine the potential cause of BAE failure, and the clinical impacts of CT BA were analyzed. RESULTS: CT BA revealed an additional 22 abnormal vessels in the qualified 10 patients, and 8 patients were treated again within 24 hours after the first BAE based on multidetector CT findings. Of the 22 abnormal vessels, 16 were embolized, including 4 orthotopic arteries, 8 ectopic arteries, and 4 nonbronchial systemic arteries (NBSAs); the remaining 6 abnormal arteries were not embolized because of normal BA (n = 1), anatomic inaccessibility (n = 2), or cessation of hemoptysis with conservative therapy (n = 3). There were no further cases of recurrent hemoptysis after the second intervention, with a mean follow-up of 7.7 months ± 6.7. Overall, initial conventional BA missed 65% of potential bleeding arteries (22 of 34). After CT BA, 73% of the newly identified vessels (16 of 22) were embolized. CONCLUSIONS: Multiple unrecognized abnormal ectopic bronchial arteries and NBSAs are the major causes of failure of initial BAE. Multidetector CT BA can precisely identify a large number of feeding vessels that are missed on conventional BA, allowing for repeat embolization with a high success rate.

Propensity score matching comparisons of postoperative complications and morbidity between digestive tract reconstruction methods after gastrectomy in gastric cancer patients with visceral obesity.

Background: Few studies have compared the prognosis of different reconstruction methods after gastrectomy for gastric cancer (GC) patients with obesity. The aim of the present study was to compare postoperative complications and overall survival (OS) between the following reconstruction methods: Billroth I (B-I), Billroth II (B-II), and Roux-en-Y (R-Y) after gastrectomy for GC patients with visceral obesity (VO). Methods: We performed a double-institutional dataset study of 578 patients who underwent radical gastrectomy with B-I, B-II, and R-Y reconstructions between 2014 and 2016. VO was defined as a visceral fat area at the level of the umbilicus greater than 100 cm2. Propensity score-matching analysis was performed to balance the significant variables. Postoperative complications and OS were compared between the techniques. Results: VO was determined in 245 patients, of which 95, 36, and 114 underwent B-I, B-II, and R-Y reconstructions, respectively. B-II and R-Y were fused into the Non-B-I group due to the similar incidence of overall postoperative complications and OS. Therefore, 108 patients were enrolled after matching. The overall postoperative complications incidence and overall operative time in the B-I group were significantly lower than those in the non-B-I group. Further, multivariable analysis showed that B-I reconstruction was an independent protective factor for overall postoperative complications (odds ratio (OR) 0.366, P=0.017). However, no statistical difference in OS was found between the two groups (hazard ratio (HR) 0.644, P=0.216). Conclusions: B-I reconstruction was associated with decreased overall postoperative complications, rather than OS, in GC patients with VO who underwent gastrectomy.