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Pb–Zn alloy is an ideal anode material for zinc electrodeposition. In this work, the microstructure of Pb–Zn alloy is controlled by composite electro-magnetic fields (CEMFs), and the mechanism is investigated. The results show that electric current pulses (ECPs) can significantly enhance the nucleation driving force for the second phase, thereby promoting the refinement of the second phase. Static magnetic field (SMF) can substantially suppress melt convection and increase the melt cooling rate around the center axis of the sample. Therefore, it is favorable for the formation of a homogeneous dispersed microstructure along the radial direction. CEMFs not only can inhibit melt convection, but also enhance the nucleation rates of Minority Phase Droplets (MPDs). This promotes the formation of a solidification microstructure in which the fine Minority Phase Particles (MPPs) are homogeneously distributed in the matrix. This work indicates that the application of CEMFs is an effective method for controlling the microstructure of monotectic alloys and it has an important industrial value. [ABSTRACT FROM AUTHOR]

Abstract: The oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) are two of the core reactions that occur in fuel cells and water electrolysis devices. Heteroatom-doped carbon materials are promising metal-free electrocatalysts to improve the conversion efficiency of these devices. To optimize the nanostructures of such carbon-based catalysts, herein, we reported an effective template method to synthesize N doped carbon nanotubes by using polydopamine as a precursor. The use of the ZnO nanowire not only serves as a self-sacrificial template to direct the formation of the nanotube, but also greatly extends the porosity of the carbon nanotube. Moreover, the polydopamine precursor also leads to effective N doping. An optimized sample, NCNT-900, shows high ORR performance comparable with that of Pt/C as well as good HER performance in both alkaline and acid media, making it one of the most effective carbon-based HER catalysts. This strategy offers an opportunity to synthesize catalysts with higher activity by rational design of a carbon precursor with higher N content or multi-heteroatom co-doping.Graphical Abstract: Nitrogen doped carbon nanotube with high performance for both ORR and HER was synthesized using ZnO nanowires as template. The obtained materials show effective N doping that provides abundant active sites, high surface area and unique textural parameters that can effectively enhance mass transfer. When used for electrocatalysts, NCNT-900 shows high ORR performance comparable with that of Pt/C and good HER performance in both alkaline and acid media. [ABSTRACT FROM AUTHOR]

Background: Laparoscopic splenectomy (LS), a treatment for both benign and malignant splenic diseases, can prove technically challenging in patients with massive splenomegaly. In particular, the optimal surgical modality for treating massive splenomegaly in children remains controversial. Methods: The clinicopathologic data of 289 pediatric patients undergoing splenectomy for massive splenomegaly were studied in a retrospective analysis. Accordingly, the patients were classified into the LS surgery group and open splenectomy (OS) surgery group. In the laparoscopy cohort, they were separated into two subgroups according to the method of surgery: the multi-incision laparoscopic splenectomy (MILS) and the single-incision laparoscopic splenectomy (SILS) surgery groups, respectively. Patient demographics, clinical data, surgery, complications, and postoperative recovery underwent analysis. Concurrently, we compared the risk of adverse laparoscopic splenectomy outcomes utilizing univariable and multivariable logistic regression. Results: The total operation time proved remarkably shorter in the OS group in contrast to the LS group (149.87 ± 61.44 versus 188.20 ± 52.51 min, P < 0.001). Relative to the OS group, the LS group exhibited lowered postoperative pain scores, bowel recovery time, and postoperative hospitalization time (P < 0.001). No remarkable difference existed in post-operation complications or mortality (P > 0.05). Nevertheless, the operation duration was remarkably longer in the SILS surgery group than in the MILS surgery group (200 ± 46.11 versus 171.39 ± 40.30 min, P = 0.02). Meanwhile, the operative duration of MILS and SILS displayed a remarkable positive association with splenic length. Moreover, the operative duration of SILS displayed a remarkable positive association with the age, weight, and height of the sick children. Splenic length proved an independent risk factor of adverse outcomes (P < 0.001, OR 1.378). Conclusions: For pediatric patients with massive splenomegaly who can tolerate prolonged anesthesia and operative procedures, LS surgery proves the optimal treatment regimen. SILS remains a novel surgery therapy which may be deemed a substitutional surgery approach for treating massive splenomegaly. [ABSTRACT FROM AUTHOR]

Dissolved organic carbon (DOC) in large river networks is an important carbon pool in the global biogeochemical cycle. DOC compositions vary spatially at global and regional scales, which influences DOC degradation and subsequent in-stream removal in river networks. The Changjiang River Network (CRN) is the third largest river system worldwide and plays an important role in DOC transformation and transportation. However, the relationships between DOC composition and degradation, as well as the quantification of in-stream removal, remain poorly understood. In this study, we chose the CRN to study spatial patterns of DOC fluorescence, as proxies for chemical composition, and degradation. Laboratory degradation experiments were conducted to explore DOC degradability and mechanisms of photodegradation and microbial respiration. We found that DOC fluorescence properties and degradation showed significant spatial differences in the lower reaches of the CRN. DOC with higher proportions of humic acid-like materials showed higher photodegradability. In degradation experiments, the total DOC loss was 49.1–66.0% over about the first 6 to 7 days. Microbial respiration removed 33.0–47.3% of total DOC, while photodegradation removed 9.0–35.3%. The relative contributions of photodegradation and microbial respiration to DOC degradation varied with different DOC fluorescence properties. The experimental values of DOC decay rate constants were 0.217–0.250 d−1. Our study improves understanding of DOC degradability, linking to its composition and providing a reference for estimating DOC in-stream removal in large river networks. [ABSTRACT FROM AUTHOR]

Cucumber (Cucumis sativus L.) fruit is a type of fleshy fruit that is harvested immaturely. Early fruit development directly determines the final fruit length and diameter, and consequently the fruit yield and quality. Different cucumber varieties display huge variations of fruit length, but how fruit length is determined at the molecular level remains poorly understood. To understand the genes and gene networks that regulate fruit length in cucumber, high throughout RNA-Seq data were used to compare the transcriptomes of early fruit from two near isogenic lines with different fruit lengths. 3955 genes were found to be differentially expressed, among which 2368 genes were significantly up-regulated and 1587 down-regulated in the line with long fruit. Microtubule and cell cycle related genes were dramatically activated in the long fruit, and transcription factors were implicated in the fruit length regulation in cucumber. Thus, our results built a foundation for dissecting the molecular mechanism of fruit length control in cucumber, a key agricultural trait of significant economic importance. [ABSTRACT FROM AUTHOR]