Mirror Plane Effect of Magnetoplumbite-Type Oxide Restraining Long-Chain Polysulfides Disproportionation for High Loading Lithium Sulfur Batteries.

A facile solid-state approach is employed to synthesize a novel magnetoplumbite-type oxide of NdMgAl11O19, which integrates spinel-stacking layers (MgAl2O4) with Nd-O6 mirror plane structures. The resulting NdMgAl11O19 exhibits remarkable catalytic activity and conversion efficiency during the sulfur reduction reaction (SRR) in lithium-sulfur batteries. By employing the 2D projection mapping technique of in situ confocal Raman spectroscopy and electrochemical technique, it is discovered that the exposed mirror plane structure of Nd-O6 can effectively suppress the undesiring disproportionation reaction (S8 2-→S6 2-+1/4 S8) of long-chain lithium polysulfides at the initial stages of sulfur reduction, thereby promoting the positive process of sulfur to lithium sulfide. This not only mitigates the issue of sulfur shuttle loss but also significantly improve the kinetics of the conversion process. Leveraging these advantages, the NdMgAl11O19/S cathode delivered an impressive initial capacity of up to 1398 mAh g-1 at an electrolyte/sulfur (E/S) ratio of 5.1 µL mg-1 and a sulfur loading of 2.3 mg cm-2. Even when the sulfur loading is increased to 10.02 mg cm-2, the cathode retained a reversible areal capacity of 10.01 mAh cm-2 after 200 cycles. This mirror engineering strategy provides valuable and universal insights into enhancing the efficiency of cathodes in Li-S battery.

Association of Malnutrition Diagnosed Using Global Leadership Initiative on Malnutrition Criteria with Severe Postoperative Complications After Gastrectomy in Patients with Gastric Cancer.

Background: The purpose of this study was to investigate the relationship between malnutrition assessed by the Global Leadership Initiative on Malnutrition (GLIM) criteria and the occurrence of severe postoperative complications (SPCs) after gastrectomy in patients with gastric cancer. Methods: A total of 220 patients with gastric cancer were included in this retrospective study. According to the GLIM criteria, the first step was to use the Nutrition Risk Screening Score 2002 to conduct nutritional risk screening for patients and the second step was to diagnose and grade the severity of malnutrition in patients at risk of malnutrition. According to the Clavien-Dindo classification system, SPCs were defined as C-D Grade IIIa or higher. Results: Overall, 66 (30.0%) patients were diagnosed with malnutrition, including 32 (14.5%) with moderate malnutrition and 34 (15.5%) with severe malnutrition. The incidence of SPCs was 14.5%, and the most frequent postoperative event was anastomotic leakage. In the multivariate regression analysis, malnutrition was considered an independent risk factor for SPCs (P < .001). After adjusting for various factors, the grading association remained statistically significant. Compared with patients with normal nutrition, patients with moderate and severe malnutrition have a nearly 15-fold (OR = 15.682, 95% CI: 4.481-54.877, P < .001) and 20-fold (OR = 20.554, 95% CI: 5.771-73.202, P < .001) increased risk of developing SPCs, respectively. Conclusions: Malnutrition assessed by GLIM was an independent risk factor for SPCs in gastric cancer patients. Therefore, early identification of malnourished patients is crucial for timely implementation of nutritional treatment and reducing the occurrence of postoperative complications.

Atomic-Scale Evidence of Catalyst Evolution for the Structure-Controlled Growth of Single-Walled Carbon Nanotubes.

ConspectusKnowing how nanomaterials nucleate and dynamically evolve at the nanoscale is crucial to understanding and in turn controlling the structure and properties of a wide variety of materials, among which single-walled carbon nanotubes (SWCNTs) with chirality-dependent properties is a typical example. Catalyst takes a central role in guiding the SWCNT growth. An in-depth understanding of the growth mechanism of SWCNTs requires knowledge of the catalyst dynamic behavior during the chemical vapor deposition process, where real-time atomic-scale observations are needed. The high spatial, temporal, and energy resolution makes the state-of-the-art aberration-corrected environmental transmission electron microscope (ETEM) a superior tool for tracking the catalyst evolution and the SWCNT growth.Several key factors and processes, including the catalyst stability, carbon diffusion pathway, nucleation site, and growth modes of nanotubes, greatly influence the structure of SWCNTs. This Account summarizes our recent progress in the ETEM investigation of the dynamic catalyst behavior and nucleation of SWCNTs. We first compare the different growth modes of SWCNTs on two types of catalyst-stable solid intermetallic Co7W6 and unstable monometallic catalysts. Then we address the origin of different growth modes and chirality selectivity by revealing the atomic-scale stability and evolution of catalysts under carbon feed conditions and the observation of the in situ growth of SWCNTs on catalysts. We also discuss the catalyst-support interaction and the possible influence on SWCNT growth. In the end, we summarize the present achievements and future challenges.We carefully compare the difference in the ordinary Co catalyst and Co7W6 catalyst which has shown great chirality selectivity in SWCNT growth. Direct imaging by ETEM demonstrated that solid catalysts initiated the growth of SWCNTs with diameters smaller (dNT) than those of the catalyst particles (dNP) (dNT < dNP), whereas molten catalyst nanoparticles produced SWCNTs with similar diameters (dNT ≈ dNP). ETEM combined with in situ synchrotron X-ray absorption spectroscopy demonstrated that the Co7W6 catalyst maintained a solid stable structure under carbon feed conditions at 700-1000 °C, demonstrating the feasibility in acting as a structure template to grow SWCNTs. By contrast, the state and composition of the Co catalyst were changing during SWCNT growth. The near-surface lattice spacings of Co7W6 remained unchanged under carbon feed condition with carbon diffusion on the surface, whereas the solid Co catalyst underwent dynamic expansion and contraction due to carbon penetration into and precipitation out of Co nanoparticles. These two different pathways of carbon diffusion on or in catalysts indicate the distinctly different growth mechanisms of SWCNTs: the epitaxial growth of SWCNTs with specified chirality on the facets of Co7W6 nanocrystals and the nonselective growth of SWCNTs by the Co catalyst with Co/CoC3 as the active species. Besides the SWCNT-catalyst interface, the catalyst-support interface is also of importance in SWCNT growth. The atomic-scale information on catalyst dynamics provides a deep mechanistic understanding of SWCNT growth and will boost the development of the structure-controlled synthesis of SWCNTs and other nanomaterials.

Doping Effect on Mesoporous Carbon-Supported Single-Site Bifunctional Catalyst for Zinc-Air Batteries.

Rechargeable zinc-air batteries (ZABs) require bifunctional electrocatalysts presenting high activity in oxygen reduction/evolution reactions (ORR/OER), but the single-site metal-N-C catalysts suffer from their low OER activity. Herein, we designed a series of single-site Fe-N-C catalysts, which present high surface area and good conductivity by incorporating into mesoporous carbon supported on carbon nanotubes, to study the doping effect of N and P on the bifunctional activity. The additional P-doping dramatically increased the content of active pyridine-N and introduced P-N/C/O sites, which not only act as extra active sites but also regulate the electron density of Fe centers to optimize the absorption of oxygenated intermediates, thereby ultimately improving the bifunctional activity of Fe-N-C sites. The optimized catalyst displayed a half-wave potential of 0.882 V for ORR and a low overpotential of 365 mV at 10 mA cm-2 for OER, which significantly outperforms the counterpart without P, as well as noble-metal-based catalysts. The ZABs with air cathodes containing the N,P-co-doped catalysts exhibited a high peak power density of 201 mW cm-2 and a long cycling stability beyond 600 h. Doping has shown to be an effective way to optimize the performance of single-site catalysts in bifunctional oxygen electrocatalysis, which can be extended to other catalyst systems.

Effect of single-incision laparoscopic distal gastrectomy guided by ERAS and the influence on immune function.

BACKGROUND: To evaluate the immune function of gastric cancer patients after single-incision laparoscopic distal gastrectomy (SIDG) or multiport laparoscopic distal gastrectomy (MLDG) guided by enhanced recovery after surgery (ERAS). METHODS: A retrospective cohort study was performed on 120 patients who underwent laparoscopic distal gastrectomy for gastric cancer. The patients were divided into two groups according to operation method: group A (MLDG) and group B (SIDG), both guided by ERAS concept. The indicators reflecting immune function and inflammation, such as CD3+, CD4+, CD8+ and NK cell count, CD4+/CD8+ cell ratios, IgA, IgM and IgG levels, C-reactive protein (CRP), total lymphocyte count (TLC) and neutrophil-to-lymphocyte ratio (NLR) were tested 3 days and 7 days after surgery. RESULTS: The skin incision length of patients in group B was significantly shorter than that in group A, but the operation time was significantly longer in group B than that in group A (P < 0.05). There were no significant differences in preoperative CD3+, CD4+, CD8+, natural killer (NK) cells, CD4+/CD8+, IgA, IgM and IgG levels between two groups (P < 0.05). Three days after surgery, the immune function indices were decreased in both groups, but with no significant difference between two groups (P > 0.05). On the 7th day after surgery, the immune indexes of both groups recovered somewhat, approaching the preoperative level (P > 0.05). Inflammation indexes increased 3 days after surgery and decreased 7 days after surgery in both groups, among them the CRP level in group A was higher than that in group B (P < 0.05). The 3-year survival rate were 96.7% in group A and 91.7% in group B, respectively, with no statistically significant difference. CONCLUSION: Compared with MLDG guided by ERAS, SIDG under the guidance of the ERAS concept has better cosmetic effect and similar effect on immune function of gastric cancer patients.

Electronic Raman Scattering in Suspended Semiconducting Carbon Nanotube.

The electronic Raman scattering (ERS) features of single-walled carbon nanotubes (SWNTs) can reveal a wealth of information about their electronic structures. Previously, the ERS processes have been exclusively reported in metallic SWNTs (M-SWNTs) and attributed to the inelastic scattering of photoexcited excitons by a continuum of low-energy electron-hole pairs near the Fermi level. Therefore, the ERS features have been thought to appear exclusively in M-SWNTs but not in semiconducting SWNTs (S-SWNTs), which are more desired in many application fields such as nanoelectronics and bioimaging. In this work, the experimental observation of the ERS features in suspended S-SWNTs is reported, the processes of which are accomplished via the available high-energy electron-hole pairs. The excitonic transition energies with an uncertainty in the order of ±1 meV can be directly obtained via the ERS spectra, compared to a typical uncertainty of ±10 meV in conventional electronic spectroscopies. The ERS features can facilitate further systematic studies on the properties of SWNT, both metallic and semiconducting, with defined chirality.

The factors related to failure of Enhanced Recovery after Surgery (ERAS) in colon cancer surgery.

PURPOSE: Enhanced Recovery after Surgery has been proven effective for patients with gastrointestinal cancer. But radical enhanced recovery could also lead to adverse clinical outcomes. Compared with reports on the estimation of successful implementation of enhanced recovery, studies on risk factors of enhanced recovery failure are still lacking. METHODS: A retrospective analysis was carried out on 102 patients in ERAS who underwent elective colon cancer surgery. This study included 102 patients with colon cancer between 2015 and 2019, defining enhanced recovery failure as postoperative length of stay over 10 days, stay in ICU over 24 h after surgery, reoperation, death, or unplanned readmission within 30 days after surgery. Univariate and multivariate analyses were performed to explore potential risk factors of failure. RESULTS: Aged ≥ 75, open operation, number of drainage tube over 1, re-urethral catheterization, and Clavien-Dindo grade over 2 were associated with ERAS failure, according to univariate analysis. Multivariate analysis showed that age ≥ 75 [OR 7.231; P = 0.009]; open operation (OR 3.599; P = 0.021); and number of drainage tube over 1 (OR 3.202; P = 0.020) were independent risk factors for ERAS failure. CONCLUSIONS: We found age ≥ 75, open operation, and number of drainage tube over 1 are independent risk factors associated with ERAS failure after colon cancer surgery.

Failure of enhanced recovery after surgery in laparoscopic colorectal surgery: a systematic review.

PURPOSE: Enhanced recovery after surgery programs has been applied extensively in laparoscopic colorectal surgery. However, several studies have found that some patients fail from ERAS programs. It is important to identify these patients so that remedial action can be taken in a timely manner. The aim of this study was to perform a systematic review of ERAS failure and related risk factors following laparoscopic colorectal surgery. METHODS: A literature search of the PubMed, EMBASE, OVID, and Cochrane databases was performed. The search strategy involved terms related to ERAS, failure, and colorectal surgery. The main outcomes were definitions of ERAS failure and related risk factors. RESULTS: Seven studies including 1463 patients were analyzed. The definition of ERAS failure was mostly associated with a prolonged postoperative length-of-stay (poLOS). Twenty-four kinds of identified risk factors were divided into three parts, the operative part, the pathophysiological part, and the ERAS elements, of which operative factors including more intraoperative blood loss and longer operative duration were the most frequently identified. CONCLUSIONS: ERAS failure was mostly related to a prolonged poLOS, and operative factors were the most frequently identified risk factors for ERAS failure following laparoscopic colorectal surgery. These findings will help physicians to take remedial action in a timely manner. Nonetheless, high-quality randomized controlled trials following a standardized framework for evaluating ERAS programs are needed in the future.

Comparison of Single-Incision and Conventional Laparoscopic Sleeve Gastrectomy for Morbid Obesity: a Meta-Analysis.

BACKGROUND: Single-incision laparoscopic sleeve gastrectomy (SILSG) has been proposed as an alternative to conventional laparoscopic sleeve gastrectomy (CLSG) in obese patients. This study aims to compare the surgical outcomes of these two techniques. METHODS: A meta-analysis of existing literature obtained through a systematic literature search in the PubMed, EMBASE, and Cochrane Library CENTRAL databases from 2009 to 2019 was conducted. RESULTS: Eleven articles including 1168 patients were analyzed. Patients in the SILSG group reported greater satisfaction with cosmetic scar outcomes than those in the CLSG group (SMD = 2.47, 95% CI = 1.10 to 3.83, P = 0.00). There was no significant difference between the SILSG group and the CLSG group regarding operative time, intraoperative estimated blood loss, conversion rate, intraoperative complications, length of hospital stay, postoperative analgesia, postoperative complications, excess weight loss (EWL), and improvements in comorbidities (P > 0.05). CONCLUSIONS: Compared to CLSG, SILSG resulted in improved cosmetic satisfaction and showed no disadvantages in terms of surgical outcomes; thus, SILSG can serve as an alternative to CLSG for obese patients. Nonetheless, high-quality randomized controlled trials (RCTs) with large study populations and long follow-up periods are needed.

Source inversion of both long- and short-lived radionuclide releases from the Fukushima Daiichi nuclear accident using on-site gamma dose rates.

Following a nuclear accident, on-site gamma dose rates provide the most complete record of atmospheric releases of both long- and short-lived radionuclides. However, they are seldom used for source inversion, because the radionuclide composition is unknown. This prevents the estimation of short-lived radionuclide releases. In this study, a method using on-site gamma dose rates is developed with the aim of determining the source term, including both long- and short-lived radionuclides. To reduce the uncertainties involved in source inversion, the proposed method uses reactor physics to obtain an a priori radionuclide composition and a reverse source term estimate as an a priori release rate. A weighted additive model is derived to handle the conflicts between the priors from different mechanisms and simultaneously incorporate them into the source inversion. The proposed method is applied to the Fukushima Daiichi accident and validated against both the on-site gamma dose rates and the regional measurements of Cs-137. The results demonstrate that the resolved a posteriori source term combines the advantages of both priors and substantially improves the predictions of the on-site gamma dose rates. Given a detailed a priori release rate, this approach also improves the regional predictions of both airborne and deposited Cs-137 concentrations.

Site-specific (Multi-scenario) validation of ensemble Kalman filter-based source inversion through multi-direction wind tunnel experiments.

Source inversion uses air dispersion models and environmental measurements to determine the atmospheric radionuclide release rate, which is critical in formulating an emergency response to nuclear incidents. Because source inversion methods are vulnerable to multiple uncertainties, site-specific validations that consider multiple air dispersion scenarios are important in ensuring their correct implementation. To comprehensively evaluate the ensemble Kalman filter (EnKF) for source inversion, a site-specific validation based on six wind tunnel experiments was performed for a highly heterogeneous nuclear power plant site in China. The six experiments cover the typical meteorology of the site and various topography types, providing abundant air dispersion scenarios for validation. The sensitivity of the EnKF to the initial guess, inflation factor, and position/number of measurements is also investigated. The results demonstrate that EnKF offers stable convergence and a reasonably bounded error in all experiments. Furthermore, the EnKF is insensitive to the initial guess, inflation factor, and number of measurements. However, it is sensitive to the position of the measurements and the air dispersion scenario. This sensitivity results from the complicated biases in air dispersion models, which highlight the key to improving the performance of EnKF.

Bilayer Plots for Accurately Determining the Chirality of Single-Walled Carbon Nanotubes Under Complex Environments.

The chirality (n,m) determines all structures and properties of a single-walled carbon nanotube (SWNT), therefore, accurate and convenient (n,m) assignments are vital in nanotube-related science and technology. Previously, a so-called Kataura plot that protracts the excitonic transition energies (Eii's) of SWNTs with various (n,m) with respect to the tube diameter (dt) has been widely utilized by researchers in the nanotube community for all (n,m)-related studies. However, the facts that both Eii and the calculated dt are subject to interactions with the environments make it inconvenient to accurately determine the (n,m) under complex environments. Here, we propose a series of bilayer plots that take into account the interactions between the SWNTs and the environments so that the (n,m) of SWNTs can be accurately determined. These plots have more advantages than the Kataura plot in concision, less data overlapping, and the suitability to be used in complex environments. We strongly encourage the researchers in the carbon nanotube community to utilize the bilayer plots for all (n,m)-related studies, especially for accurate and convenient (n,m) determination.

Enhanced air dispersion modelling at a typical Chinese nuclear power plant site: Coupling RIMPUFF with two advanced diagnostic wind models.

An enhanced air dispersion modelling scheme is proposed to cope with the building layout and complex terrain of a typical Chinese nuclear power plant (NPP) site. In this modelling, the California Meteorological Model (CALMET) and the Stationary Wind Fit and Turbulence (SWIFT) are coupled with the Risø Mesoscale PUFF model (RIMPUFF) for refined wind field calculation. The near-field diffusion coefficient correction scheme of the Atmospheric Relative Concentrations in the Building Wakes Computer Code (ARCON96) is adopted to characterize dispersion in building arrays. The proposed method is evaluated by a wind tunnel experiment that replicates the typical Chinese NPP site. For both wind speed/direction and air concentration, the enhanced modelling predictions agree well with the observations. The fraction of the predictions within a factor of 2 and 5 of observations exceeds 55% and 82% respectively in the building area and the complex terrain area. This demonstrates the feasibility of the new enhanced modelling for typical Chinese NPP sites.