Advancements in silicon carbide-based supercapacitors: materials, performance, and emerging applications.

Silicon carbide (SiC) nanomaterials have emerged as promising candidates for supercapacitor electrodes due to their unique properties, which encompass a broad electrochemical stability range, exceptional mechanical strength, and resistance to extreme conditions. This review offers a comprehensive overview of the latest advancements in SiC nanomaterials for supercapacitors. It encompasses diverse synthesis methods for SiC nanomaterials, including solid-state, gas-phase, and liquid-phase synthesis techniques, while also discussing the advantages and challenges associated with each method. Furthermore, this review places a particular emphasis on the electrochemical performance of SiC-based supercapacitors, highlighting the pivotal role of SiC nanostructures and porous architectures in enhancing specific capacitance and cycling stability. A deep dive into SiC-based composite materials, such as SiC/carbon composites and SiC/metal oxide hybrids, is also included, showcasing their potential to elevate energy density and cycling stability. Finally, the paper outlines prospective research directions aimed at surmounting existing challenges and fully harnessing SiC's potential in the development of next-generation supercapacitors.

Feasibility and efficacy of transthoracic single-port assisted laparoscopic esophagogastrectomy for Siewert type II adenocarcinoma of the esophagogastric junction.

BACKGROUND: The surgical treatment of Siewert type II adenocarcinoma of the esophagogastric junction (AEG) is controversial, and no systematic technology has been established. The aim of this retrospective study is to introduce the technology of transthoracic single-port assisted laparoscopic esophagogastrectomy. METHODS: Data from patients with Siewert type II AEG who underwent transthoracic single-port assisted laparoscopic esophagogastrectomy in Guangdong Provincial Hospital of Chinese Medicine from May 2017 to December 2020 were analyzed. RESULTS: A total of 35 patients, including 30 males and 5 females, were enrolled in this study. Eight patients underwent proximal gastrectomy while the other 27 patients underwent total gastrectomy. The median operative times were 247.5 (195.0-275.0) min and 290.0 (173.0-530.0) min for proximal and total gastrectomy, respectively. The median lower mediastinal lymph node dissection (LMLD) time was 41.5 (20.0-57.0) min and the median estimated blood loss was 100.0 (20.0-200.0) mL. The median number of harvested mediastinal lymph nodes was 5 [2-13]. Lower mediastinal lymph node metastasis occurred in 9 patients (25.7%). The lower mediastinal lymph node metastasis rate was significantly higher in patients with esophageal involvement exceeding 2 cm [>2 vs. ≤2 cm: 55.6% (5/9) vs. 15.4% (4/26), P=0.03]. The median postoperative hospital stay was 10 [6-73] days. Overall morbidity was 11.8% (4 patients), including 2 cases of pleural effusion, 1 case of pancreatic fistula, and 1 case of anastomotic leakage. CONCLUSIONS: Transthoracic single-port assisted laparoscopic esophagogastrectomy is safe and feasible. It has the advantages of reducing the difficulty of LMLD and digestive tract reconstruction.

Advanced Supercapacitors Based on Porous Hollow Carbon Nanofiber Electrodes with High Specific Capacitance and Large Energy Density.

Hollow carbon nanofibers with hierarchical porous shells were prepared by NaOH activation of the electrospinning SiCNO fibers, followed by carbonization treatment. By adjusting the carbonization temperature, porous hollow carbon nanofibers with different Brunauer-Emmett-Teller (BET) specific surface areas and total pore volumes are obtained, both of which are explored as electrode materials for supercapacitors. It was found that the obtained products (HCF800) possess the highest BET specific surface area of 2628.10 m2/g and the largest pore volume of 2.32 cm3/g when the carbonized temperature was designed at 800 °C, thus displaying the best supercapacitor performance. The electrochemical results in a three-electrode system show that HCF800 exhibits a high specific capacitance of 330.11 F/g as the discharge current density is 1 A/g and still maintains 65.3% of its original specific capacitance when the current density reaches 20 A/g. Moreover, in a two-electrode system, HCF800 also exhibits an excellent specific capacity of 259.86 F/g at a current density of 1 A/g, marvelous cyclic stability with the specific capacitance retention of 95.3% even after 10,000 cycles, and a large energy density of 12.99 W h/kg at 1.0 A/g. Significantly, the supercapacitor performance of these porous hollow carbon nanofibers is also superior to that of many previously reported carbon materials, which proved them to be worthy candidates for high-performance electrode materials.

Comparison of efficiency of inhaled and intravenous corticosteroid on pregnant women with COPD and the effects on the expression of PCT and hs-CRP.

The efficiency of inhaled and systemic corticosteroids on pregnant women with chronic obstructive pulmonary disease (COPD) was investigated. The study also compared the effects of the administration on the expression of inflammatory mediator procalcitonin (PCT) and high-sensitivity C-reactive protein (hs-CRP). A total of 120 pregnant COPD patients were recruited and randomly allocated into the following three groups: Intravenous corticosteroid treatment group (n=42), inhaled corticosteroid treatment group (n=38), and control group (without any corticosteroid treatment, n=40). Patients of the all three groups received symptomatic supportive treatments including oxygen therapy, anti-infection therapy, expectorant, and bronchodilator. The serum PCT and hs-CRP expression levels were measured before treatment and after 7 days of treatment. Moreover, the clinical parameters such as symptoms, blood gas analysis parameters, pulmonary function indexes, fasting blood glucose (FBG) and adverse reactions were recorded. The overall clinical effective rates of the group received budesonide inhalation and the group receiving systemic methylprednisolone treatment were comparable. Both treatments were able to reduce the levels of inflammatory mediators, hs-CRP and PCT. On the other hand, treatments increased PaO2 of arterial blood gas while reducing PaCO2, thereby improving the lung function (FEV1% pred and FEV1/FVC) (P>0.05). The study observed that the FBG levels in COPD patients receiving systemic corticosteroid treatment were significantly increased, while budesonide inhalation did not significantly affect the FBG levels. In addition, rates of adverse events (such as mouth dry, oral ulcers, hoarseness) of systemic corticosteroid treatment group were significantly higher than those in inhaled corticosteroid treatment group and control group (38.1% vs. 17.5% vs. 5.0%, comparison between groups: P<0.05). In conclusion, inhaled and systemic use of corticosteroid both significantly improved dyspnea and other clinical symptoms of pregnant COPD patients by increasing oxygen partial pressure, correcting hypoxemia, and enhancing lung function. Moreover, fewer adverse reactions were observed with inhaled corticosteroid treatment, suggesting that inhaled administration is a relatively good, safe and effective treatment for pregnant COPD patients.

Mesporous 3C-SiC Hollow Fibers.

In the present work, for the first time, we reported the exploration of mesoporous 3C-SiC hollow fibers via single-spinneret electrospinning of polyureasilazane (PSN) and polyvinylpyrrolidone (PVP) solution followed by high-temperature pyrolysis treatment. The resultant products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM) and N2 adsorption. The as-prepared hollow fibers with totally mesoporous walls were uniformly sized in diameter and high purity in morphology. They were composed of single-crystalline 3C-SiC nanoparticles with a surface area of 21.75 m2/g and average pore diameter of ~34 nm. The PSN concentration played a determined role on the formation of hollow fibers rather than the conventional solid counterparts, enabling their growth in a tunable manner. A possible mechanism was proposed for the formation of mesoporous SiC hollow fiber.