S-Doping of an Fe/N/C ORR Catalyst for Polymer Electrolyte Membrane Fuel Cells with High Power Density.

Fe/N/C is a promising non-Pt electrocatalyst for the oxygen reduction reaction (ORR), but its catalytic activity is considerably inferior to that of Pt in acidic medium, the environment of polymer electrolyte membrane fuel cells (PEMFCs). An improved Fe/N/C catalyst (denoted as Fe/N/C-SCN) derived from Fe(SCN)3, poly-m-phenylenediamine, and carbon black is presented. The advantage of using Fe(SCN)3 as iron source is that the obtained catalyst has a high level of S doping and high surface area, and thus exhibits excellent ORR activity (23 A g(-1) at 0.80 V) in 0.1 M H2SO4 solution. When the Fe/N/C-SCN was applied in a PEMFC as cathode catalyst, the maximal power density could exceed 1 W cm(-2).

Phenylenediamine-based FeN(x)/C catalyst with high activity for oxygen reduction in acid medium and its active-site probing.

High-temperature pyrolyzed FeN(x)/C catalyst is one of the most promising nonprecious metal electrocatalysts for oxygen reduction reaction (ORR). However, it suffers from two challenging problems: insufficient ORR activity and unclear active site structure. Herein, we report a FeN(x)/C catalyst derived from poly-m-phenylenediamine (PmPDA-FeN(x)/C) that possesses high ORR activity (11.5 A g(-1) at 0.80 V vs RHE) and low H2O2 yield (<1%) in acid medium. The PmPDA-FeN(x)/C also exhibits high catalytic activity for both reduction and oxidation of H2O2. We further find that the ORR activity of PmPDA-FeN(x)/C is not sensitive to CO and NO(x) but can be suppressed significantly by halide ions (e.g., Cl(-), F(-), and Br(-)) and low valence state sulfur-containing species (e.g., SCN(-), SO2, and H2S). This result reveals that the active sites of the FeN(x)/C catalyst contains Fe element (mainly as Fe(III) at high potentials) in acid medium.

Comparative Study of Complications and Incision Esthetic Satisfaction Between Single-Port Laparoscopy and Traditional Laparoscopy in Benign Gynecological Surgery.

OBJECTIVE: Single-port laparoscopic surgery (SPLS) is an effective, minimally invasive, feasible, and promising surgical technique for the treatment of various benign and malignant gynecological diseases. This study aimed to evaluate the differences in surgical conditions, complications, and esthetic incisions between SPLS and traditional laparoscopic surgery (TLS) in benign gynecological surgeries. METHODS: Fifty-one eligible patients were included, and their general information (age, surgical approach), surgical conditions (surgical time, blood loss, postoperative first flatus), postoperative pain, and incision healing were collected. RESULTS: There was a significant difference in the results of hysterectomy between the two groups. The surgical time in the SPLS group was significantly shorter than that in the TLS group (p = 0.026). Furthermore, the SPLS group had less blood loss (p < 0.05) and earlier postoperative first flatus (p < 0.05) than the control group. There was no significant difference in postoperative conditions between the two groups. During the follow-up, it was found that the Vancouver Scar Scale score was 8.37 ± 2.30 in the control group and 6.81 ± 2.14 in the study group. The cosmetic effect and satisfaction were better in the SPLS group (p = 0.018). Subgroup analysis showed that in other benign gynecological diseases without uterine lesions, SPLS significantly improved surgical time, intraoperative blood loss, and postoperative first flatus (p < 0.05). CONCLUSION: SPLS demonstrated good clinical efficacy in benign gynecological surgery, with shorter surgical time, less blood loss, earlier postoperative first flatus, fewer complications, and better cosmetic effects of scars.

Mycotoxins binder supplementation alleviates aflatoxin B1 toxic effects on the immune response and intestinal barrier function in broilers.

This experiment was conducted to evaluate whether a commercial mycotoxins-binder, XL, could effectively attenuate the negative effects of Aflatoxin B1 (AFB1) on growth performance, immunological function, and intestinal health in birds. Two hundred forty 1-day-old Arbor Acres broiler chickens were randomly divided into 4 treatments using a 2 × 2 factorial randomized design with 2 levels of dietary mycotoxins binder (0 or 2g /kg) and 2 AFB1 supplemented levels (0 or 200 µg/kg) from 0 to 42 d. Results showed that AFB1 exposure impaired growth performance by decreasing BWG in 1-21 d and 1-42 d, decreasing FI in 1-21 d, increasing FCR in 1-21 d and 1-42 d (P < 0.05). Broilers fed AFB1- contaminated diet impaired the immune function, as evident by decreasing IgA contents, Newcastle disease antibody titers in serum, and sIgA contents of jejunal mucosa at 21 d (P < 0.05). On the other hand, AFB1 challenge significantly increased the gene expression of proinflammatory factors in spleen at 21 d and liver at 42 d, and significantly decreased claudin-1 expression at 42 d and occludin expression at 21 d, and increased claudin-2 at 21 d in jejunum of broiler chickens (P < 0.05) compared to the basal diet group. Dietary XL supplementation significantly decreased the gene expression of IL-6 in spleen at 21 d and IL-1ß in liver at 42 d, cytochrome P450 3A4 (CYP3A4) expression in liver at 21 d of broilers (P < 0.05) compared with the nonsupplemented birds, regardless of AFB1 challenged or not. Inclusion of 2 g/kg XL increased serum ALB at 42 d, IgM and IgA at 42 d, Newcastle disease antibody titer level at 35 d (P < 0.05). Dietary XL addition enhanced intestinal barrier function by increasing the expression of claudin-1 at 21 d and Occludin at 42 d (P < 0.05) in jejunum. Conclusively, 2 g/kg mycotoxins-binder can relieve the toxic effect of AFB1 on broilers.

Intestinal Microbiota Regulate Certain Meat Quality Parameters in Chicken.

Growing evidence of intestinal microbiota-muscle axis provides a possibility to improve meat quality of broilers through regulating intestinal microbiota. Water-holding capacity is a crucial factor to evaluate the meat quality. High quality of water-holding capacity is usually described as a low drip-losing rate. This study aimed to explore the relationship between intestinal microbiota and water-holding capacity of muscle in broilers. According to our results, two native breeds of broilers (the Arbor Acres broilers and the Beijing-You broilers) exhibited remarkable differences in microbiota composition. However, the regular of gut bacteria compositions gradually became similar when the two breeds of broiler were raised in a same feeding environment. Therefore, this similar regular of intestinal microbiota induced similar water-holding capacity of the muscle from the two breeds. In subsequent fecal microbiota transplantation (FMT) experiments, the intestinal microbiota community of the Arbor Acres broilers was remodeling by oral gavage of bacterial suspension that was derived from the Beijing-You broilers. Then, not only body weight and abdominal fat rate were increased, but also drip loss of muscle was decreased in the Arbor Acres broilers. Additionally, muscle fiber diameter of biceps femoris muscle and expression of MyoD1 were notably enlarged. Muscle fiber diameter and related genes were deemed as important elements for water-holding capacity of muscle. Simultaneously, we screened typical intestinal bacteria in both the two native breeds of broilers by 16S rDNA sequencing. Lachnoclostridium was the only bacteria genus associated with drip-losing rate, meat fiber diameter, body weight, and abdominal fat rate. Importance: Higher body weight and superior meat quality in livestock imply an adequate source of protein and substantial commercial value. Regulating the intestinal microbiota of broilers is a promising approach to optimize commercial phenotypes. Our results indicate that the intestinal microbiota profile could be reconstructed by external factors, leading to advantageous changes in muscle characteristics. The cecum microbiota of native broilers have the ability to improve certain meat quality and production performance. The population of Lachnoclostridium spp. could be used to regulate body weight and drip-losing rate in broilers, but more study is needed.

Role of Vitamin K in Intestinal Health.

Intestinal diseases, such as inflammatory bowel diseases (IBDs) and colorectal cancer (CRC) generally characterized by clinical symptoms, including malabsorption, intestinal dysfunction, injury, and microbiome imbalance, as well as certain secondary intestinal disease complications, continue to be serious public health problems worldwide. The role of vitamin K (VK) on intestinal health has drawn growing interest in recent years. In addition to its role in blood coagulation and bone health, several investigations continue to explore the role of VK as an emerging novel biological compound with the potential function of improving intestinal health. This study aims to present a thorough review on the bacterial sources, intestinal absorption, uptake of VK, and VK deficiency in patients with intestinal diseases, with emphasis on the effect of VK supplementation on immunity, anti-inflammation, intestinal microbes and its metabolites, antioxidation, and coagulation, and promoting epithelial development. Besides, VK-dependent proteins (VKDPs) are another crucial mechanism for VK to exert a gastroprotection role for their functions of anti-inflammation, immunomodulation, and anti-tumorigenesis. In summary, published studies preliminarily show that VK presents a beneficial effect on intestinal health and may be used as a therapeutic drug to prevent/treat intestinal diseases, but the specific mechanism of VK in intestinal health has yet to be elucidated.

Genistein Inhibits Colonic Goblet Cell Loss and Colorectal Inflammation Induced by Salmonella Typhimurium Infection.

SCOPE: Salmonella is the main food-borne pathogen, which can infect intestinal epithelial cells and causes colitis. Genistein has a variety of biological activities that alleviates colitis induced by sodium dextran sulfate in a variety of ways, but its protective effects on colitis caused by pathogenic bacteria are still unknown. METHODS AND RESULTS: This study explores the protective effect of genistein in reducing colitis caused by Salmonella infection. Salmonella causes colon inflammation through activating cyclooxygenase-2/prostaglandin E2, and genistein inhibits colitis caused by Salmonella typhimurium infection. Salmonella infection increases colonic mucosal damage, proliferating cells, and goblet cell loss, while the administration of genistein solves these pathological changes. In addition, it is further proved that Salmonella causes severe colitis related to goblet cell loss and activates the host crypt stem cells to repair the damaged epithelium. Salmonella infection inhibites the host mammalian target of rapamycin, activates light chain 3 II pathways to induce autophagy to eliminate pathogenic bacteria. Genistein increases Lactobacillus in feces and reduces Salmonella colonization to inhibit colitis induces by Salmonella infection. CONCLUSION: This study demonstrates genistein alleviated colitis and inhibites the goblet cell loss causes by Salmonella infection through regulating the gut bacteria and intestinal stem cell development.

Protective Effect of Kaempferol on LPS-Induced Inflammation and Barrier Dysfunction in a Coculture Model of Intestinal Epithelial Cells and Intestinal Microvascular Endothelial Cells.

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of intestinal mucosa and submucosa, characterized by the disruption of the intestinal epithelial barrier, increased production of inflammatory mediators, and excessive tissue injury. Intestinal epithelial cells, as well as microvascular endothelial cells, play important roles in IBD. To study the potential effects of kaempferol in IBD progress, we established a novel epithelial-endothelial cells coculture model to investigate the intestinal inflammation and barrier function. Data demonstrated an obvious increased transepithelial electrical resistance (TEER) (1222 ± 60.40 Ω cm2 vs 1371 ± 38.77 Ω cm2), decreased flux of FITC (180.8 ± 20.06 µg/mL vs 136.7 ± 14.78 µg/mL), and up-regulated occludin and claudin-2 expression in Caco-2 that was specifically cocultured with endothelial cells. Meanwhile, 80 µM kaempferol alleviated the drop of TEER, the increase of FITC flux, and the overexpression of interleukin-8 (IL-8) induced by 1 µg/mL lipopolysaccharide (LPS). Additionally, kaempferol also ameliorated the LPS-induced decrease of protein expression of zonula occludens-1 (ZO-1), occludin, and claudin-2, together with the inhibited protein expressions of the phosphorylation level of NF-κB and I-κB induced by LPS. Our results suggest that kaempferol alleviates the IL-8 secretion and barrier dysfunction of the Caco-2 monolayer in the LPS-induced epithelial-endothelial coculture model via inhibiting the NF-κB signaling pathway activation.

Exogenous L-arginine increases intestinal stem cell function through CD90+ stromal cells producing mTORC1-induced Wnt2b.

The renewal and repair of intestinal epithelium depend on the self-renewal of intestinal stem cells (ISCs) under physiological and pathological conditions. Although previous work has established that exogenous nutrients regulate adult stem cell activity, little is known about the regulatory effect of L-arginine on ISCs. In this study we utilize mice and small intestinal (SI) organoid models to clarify the role of L-arginine on epithelial differentiation of ISCs. We show that L-arginine increases expansion of ISCs in mice. Furthermore, CD90+ intestinal stromal cells augment stem-cell function in response to L-arginine in co-culture experiments. Mechanistically, we find that L-arginine stimulates Wnt2b secretion by CD90+ stromal cells through the mammalian target of rapamycin complex 1 (mTORC1) and that blocking Wnt2b production prevents L-arginine-induced ISC expansion. Finally, we show that L-arginine treatment protects the gut in response to injury. Our findings highlight an important role for CD90+ stromal cells in L-arginine-stimulated ISC expansion.

Aminothiazole-derived N,S,Fe-doped graphene nanosheets as high performance electrocatalysts for oxygen reduction.

N,S,Fe-doped graphene nanosheets were directly synthesized from aminothiazole, a precursor molecule that contains N and S atoms, through Fe catalysis under heat treatment. The graphene nanosheets exhibited high electrocatalytic activity toward oxygen reduction reaction in both acidic and alkaline media during rotating disk electrode half-cell and fuel cell tests.