Dual-functional single-atomic Mo/Fe clusters-decorated C3N5 via three electron-pathway in oxygen reduction reaction for tandemly removing contaminants from water.

Inspired by the development of single-atom catalysts (SACs), the fabrication of multimetallic SACs can be a promising technical approach for the in situ electro-Fenton (EF) process. Herein, dual-functional atomically dispersed Mo-Fe sites embedded in carbon nitride (C3N5) (i.e., MoFe/C3N5) were synthesized via a facile SiO2 template method. The atomically isolated bimetallic configuration in MoFe/C3N5 was identified by combining the microscopic and spectroscopic techniques. The MoFe/C3N5 catalyst on the cathode exhibited a remarkable catalytic activity toward the three electron-dominated oxygen reduction reaction in sodium sulfate, leading to a highly effective EF reaction with a low overpotential for the removal of organic contaminants from wastewater. The new catalyst showed a superior performance over its conventional counterparts, owing to the dual functions of the dual-metal active sites. Density functional theory (DFT) analysis revealed that the dual-functional 50-MoFe/C3N5 catalyst enabled a synergistic action of the Mo-Fe dual single atomic centers, which can alter the adsorption/dissociation behavior and decrease the overall reaction barriers for effective organic oxidation during the EF process. This study not only sheds light on the controlled synthesis of atomically isolated catalyst materials but also provides deeper understanding of the structure-performance relationship of the nanocatalysts with dual active sites for the catalytic EF process. Additionally, the findings will promote the advanced catalysis for the treatment of emerging organic contaminants in water and wastewater.

Propensity score-matched comparison between totally laparoscopic right hemicolectomy with transcolonic natural orifice specimen extraction and conventional laparoscopic surgery with mini-laparotomy in the treatment of ascending colon cancer (with video).

BACKGROUND AND AIMS: Now that the debate about the safety and effectiveness of laparoscopic versus open surgery is over, attention has turned to innovations that can verify whether minimizing the impact of laparoscopy on the abdominal wall can further reduce pain, improve patient comfort, lead to superior cosmesis, and reduce morbidity. The aim of this study was to further explore the application value of totally laparoscopic right hemicolectomy with transcolonic natural orifice specimen extraction (NOSE) and to evaluate the short-term efficacy of transcolonic NOSE surgery for resecting specimens of ascending colon cancer. METHODS: From January 2016 to May 2017, a retrospective study was conducted in Guangxi. Propensity score matching was used to minimize the bias from nonrandomized treatment assignment. Patients were followed up through May 2020. RESULTS: Forty-nine patients underwent totally laparoscopic right hemicolectomy with transcolonic NOSE and 116 patients laparoscopic right hemicolectomy with mini-laparotomy (ML) procedures at our institution. After propensity score matching, each group included 45 patients, and all covariate imbalances were alleviated. The transcolonic NOSE group and the ML group did not differ significantly in terms of baseline clinical characteristics. The transcolonic NOSE group was associated with a shorter time to first flatus (NOSE vs ML: 1.8 ± .5 vs 3.2 ± .8, P = .032), a shorter length of hospital stay (11.3 ± 2.5 days vs 13.0 ± 3.1 days, P = .034), a shorter time to first liquid intake (2.6 ± .8 vs 3.8 ± .9, P = .068), less pain (1.8 ± .8 vs 4.2 ± .7, P = .013), less analgesia requirement (6 [13.3%] vs 21 [46.7%], P = .001), and lower C-reactive protein levels on postoperative day 1 (3.6 ± 1.7 vs 8.2 ± 2.2, P = .001) and postoperative day 3 (NOSE 2.4 ± 1.4 vs M: 4.6 ± 1.7 [P = .013]) than the ML group. The median follow-up was 28.4 months (interquartile range, 18.0-36.0). The 3-year overall survival rates were similar between the transcolonic NOSE group and the ML group. CONCLUSIONS: In total, laparoscopic right hemicolectomy with transcolonic specimen extraction appears to be safe for selected patients with ascending colon cancer as a minimally invasive surgery.

Singlet Oxygen Triggered by Superoxide Radicals in a Molybdenum Cocatalytic Fenton Reaction with Enhanced REDOX Activity in the Environment.

As an important reactive oxygen species (ROS) with selective oxidation, singlet oxygen (1O2) has wide application prospects in biology and the environment. However, the mechanism of 1O2 formation, especially the conversion of superoxide radicals (·O2-) to 1O2, has been a great controversy. This process is often disturbed by hydroxyl radicals (·OH). Here, we develop a molybdenum cocatalytic Fenton system, which can realize the transformation from ·O2- to 1O2 on the premise of minimizing ·OH. The Mo0 exposed on the surface of molybdenum powder can significantly improve the Fe3+/Fe2+ cycling efficiency and weaken the production of ·OH, leading to the generation of ·O2-. Meanwhile, the exposed Mo6+ can realize the transformation of ·O2- to 1O2. The molybdenum cocatalytic effect makes the conventional Fenton reaction have high oxidation activity for the remediation of organic pollutants and prompts the inactivation of Staphylococcus aureus, as well as the adsorption and reduction of heavy metal ions (Cu2+, Ni2+, and Cr6+). Compared with iron powder, molybdenum powder is more likely to promote the conversion from Fe3+ to Fe2+ during the Fenton reaction, resulting in a higher Fe2+/Fe3+ ratio and better activity regarding the remediation of organics. Our findings clarify the transformation mechanism from ·O2- to 1O2 during the Fenton-like reaction and provide a promising REDOX Fenton-like system for water treatment.

Modulation of the Reduction Potential of TiO2- x by Fluorination for Efficient and Selective CH4 Generation from CO2 Photoreduction.

Photocatalytic reduction of CO2 holds great promises for addressing both the environmental and energy issues that are facing the modern society. The major challenge of CO2 photoreduction into fuels such as methane or methanol is the low yield and poor selectivity. Here, we report an effective strategy to enhance the reduction potential of photoexcited electrons by fluorination of mesoporous single crystals of reduced TiO2- x. Density functional theory calculations and photoelectricity tests indicate that the Ti3+ impurity level is upswept by fluorination, owing to the built-in electric field constructed by the substitutional F that replaces surface oxygen vacancies, which leads to the enhanced reduction potential of photoexcited electrons. As a result, the fluorination of the reduced TiO2- x dramatically increases the CH4 production yield by 13 times from 0.125 to 1.63 µmol/g·h under solar light illumination with the CH4 selectivity being improved from 25.7% to 85.8%. Our finding provides a metal-free strategy for the selective CH4 generation from CO2 photoreduction.

Enhancement of H2O2 Decomposition by the Co-catalytic Effect of WS2 on the Fenton Reaction for the Synchronous Reduction of Cr(VI) and Remediation of Phenol.

The greatest problem in the Fe(II)/H2O2 Fenton reaction is the low production of ·OH owing to the inefficient Fe(III)/Fe(II) cycle and the low decomposition efficiency of H2O2 (<30%). Herein, we report a new discovery regarding the significant co-catalytic effect of WS2 on the decomposition of H2O2 in a photoassisted Fe(II)/H2O2 Fenton system. With the help of WS2 co-catalytic effect, the H2O2 decomposition efficiency can be increased from 22.9% to 60.1%, such that minimal concentrations of H2O2 (0.4 mmol/L) and Fe2+ (0.14 mmol/L) are necessary for the standard Fenton reaction. Interestingly, the co-catalytic Fenton strategy can be applied to the simultaneous oxidation of phenol (10 mg/L) and reduction of Cr(VI) (40 mg/L), and the corresponding degradation and reduction rates can reach up to 80.9% and 90.9%, respectively, which are much higher than the conventional Fenton reaction (52.0% and 31.0%). We found that the expose reductive W4+ active sites on the surface of WS2 can greatly accelerate the rate-limiting step of Fe3+/Fe2+ conversion, which plays the key role in the decomposition of H2O2 and the reduction of Cr(VI). Our discovery represents a breakthrough in the field of inorganic catalyzing AOPs and greatly advances the practical utility of this method for environmental applications.

Online Running-Gait Generation for Bipedal Robots with Smooth State Switching and Accurate Speed Tracking.

Smooth state switching and accurate speed tracking are important for the stability and reactivity of bipedal robots when running. However, previous studies have rarely been able to synthesize these two capabilities online. In this paper, we present an online running-gait generator for bipedal robots that allows for smooth state switching and accurate speed tracking. Considering a fluctuating height nature and computational expediency, the robot is represented by a simplified variable-height inverted-pendulum (VHIP) model. In order to achieve smooth state switching at the beginning and end of running, a segmented zero moment point (ZMP) trajectory optimization is proposed to automatically provide a feasible and smooth center-of-mass (CoM) trajectory that enables the robot to stably start or stop running at the given speed. To accurately track online the desired speed during running, we propose an iterative algorithm to compute target footholds, which allows for the robot to follow the interactive desired speed after the next two steps. Lastly, a numerical experiment and the simulation of online variable speed running were performed with position-controlled bipedal robot BHR7P, and the results verified the effectiveness of the proposed methods.

Comprehensive landscape of the IPAF inflammasomes in pan-cancer: A bulk omics research and single-cell sequencing validation.

BACKGROUND: IPAF (ICE-protease Activating Factor) is a nucleotide-binding/leucine-rich repeat (NLR) protein known as the cysteine-associated recruitment domain 12 (CARD12). Previous studies only discuss the role of IPAF inflammasomes in specific tumors. The role of IPAF inflammasomes in pan-cancer is still unclear. Therefore, we performed a comprehensive analysis of IPAF inflammasome in 33 tumors. METHODS: We used databases like The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) from the UCSC XENA (http://xena.ucsc.edu/) to retrieve and analyze gene expression. The influence of IPAF inflammasome on the prognosis of tumor patients was analyzed using univariate Cox regression analysis and Kaplan-Meier survival analysis. Furthermore, we conducted the following analysis: Single-sample gene set enrichment analysis, single-cell level functional state analysis, single-cell sequencing, immune cell infiltration analysis, and tumor immune dysfunction and exclusion (TIDE) score. RESULTS: First, the differential expression of IPAF inflammasome-related genes (IPAF-RGs) in 33 tumors were analyzed. The results revealed that IPAF-RGs were significantly and differentially expressed in eight tumors. The prognostic significance of IPAF inflammasome scores was different in different tumors. A positive correlation was observed between IPAF inflammasomes scores and CD8+ T cells in most tumors. Further analysis revealed that IPAF inflammasome might affect tumor immunity mainly by mediating effector T cell recruitment via the expression of chemokines such as CXCL9, CXCL10, and CCL5. The analysis of TIDE and IPAF inflammasome scores revealed a significant negative correlation between IPAF inflammasome and TIDE scores in 11 tumors. CONCLUSION: A pan-cancer analysis of IPAF inflammasome in various tumors was performed. The results highlight the potential value of IPAF inflammasome in response to immunotherapy in patients and provide a new direction for future immunotherapy.

A comprehensive review on reactive oxygen species (ROS) in advanced oxidation processes (AOPs).

In this account, the reactive oxygen species (ROS) were comprehensively reviewed, which were based on electro-Fenton and photo-Fenton processes and correlative membrane filtration technology. Specifically, this review focuses on the fundamental principles and applications of advanced oxidation processes (AOPs) based on a series of nanomaterials, and we compare the pros and cons of each method and point out the perspective. Further, the emerging reviews regarding AOPs rarely emphasize the involved ROS and consider the convenience of radical classification and transformation mechanism, such a review is of paramount importance to be needed. Owing to the strong oxidation ability of radical (e.g., •OH, O2•-, and SO4•-) and non-radical (e.g., 1O2 and H2O2), these ROS would attack the organic contaminants of emerging concern, thus achieving the goal of environmental remediation. Hopefully, this review can offer detailed theoretical guidance for the researchers, and we believe it able to offer the frontier knowledge of AOPs for wastewater treatment plants (WWTPs).

Comprehensive pan-cancer analysis identifies cellular senescence as a new therapeutic target for cancer: multi-omics analysis and single-cell sequencing validation.

Although cellular senescence has long been recognized as an anti-tumor mechanism, mounting evidence suggests that in some circumstances, senescent cells promote tumor growth and malignancy spread. Therefore, research into the exact relationship between cellular senescence and tumor immunity is ongoing. We analyzed changes in the expression, copy number variation, single-nucleotide variation, methylation, and drug sensitivity of cellular senescence-related genes in 33 tumor types. The cellular senescence score was calculated using the single-sample gene-set enrichment analysis. The correlations between cellular senescence score and prognosis, tumor immune microenvironment (TIME), and expression of tumor immune-related genes were comprehensively analyzed. Single-cell transcriptome sequencing data were used to assess the activation state of cellular senescence in the tumor microenvironment (TME). The expression of cellular senescence-associated hub genes varied significantly across cancer types. In these genes, missense mutation was the major type of single nucleotide polymorphism, and heterozygous deletion and heterozygous amplification were the major types of copy number variation. Moreover, the cellular senescence pathway in tumors was sensitive to drugs such as XMD13-2, TPCA-1, methotrexate, and KIN001-102. Furthermore, the cellular senescence score was significantly higher in most cancer types, related to poor prognosis. The expression of immune checkpoint molecules such as NRP1, CD276, and CD44 was significantly correlated with the cellular senescence score. Monocyte cellular senescence was significantly higher in the TME of kidney renal clear cell carcinoma cells than in normal tissues. The findings of this study provide insights into the important role of cellular senescence in the TIME of human cancers and the effect of immunotherapy.

Novel Fenton process of Co-catalyst Co9S8 quantum dots for highly efficient removal of organic pollutants.

Advanced oxidation processes (AOPs) have been widely accepted as an efficient and promising strategy for treating organic pollutants, is mainly dominated by hydroxyl radicals (•OH); however, its further practical application has been hindered by its low decomposition rate of H2O2. Hence, for the first time, we propose an eco-friendly and facile synthesis methodology synthesize water-soluble Co9S8 quantum dots (QDs) derived from commercial cobalt disulfide (CoS2), which can serve as excellent co-catalysts to dramatically enhance the decomposition rate of H2O2. It is demonstrated that the conversion rate of H2O2 into •OH is ca. 80.02% promoted by Co9S8 QDs, whereas the conventional Fenton process is ca. 34.9%. The result shows that unsaturated edged S atoms on the surface of Co9S8 play a pivotal role in this enhancement, where the number of protons will react with sulfur atoms to form H2S and expose reductive metallic active sites to accelerate the Fe3+/Fe2+ conversion. In addition, to tackle the issue for difficult recovery of liquid quantum dots, the magnetic Co9S8 QDs/Fe3O4 nanoparticles are particularly synthesized, which show excellent performance for degradation of 20 mg/L Rhodamine B (RhB). Moreover, the TOC degradation rate can remain stable at 80% even after five cycles. It is expected that this work will provide a new pathway of thinking in the Fenton process and impulse the usage of liquid quantum dots in practical AOPs application.

Identification of four gastric cancer subtypes based on genetic analysis of cholesterogenic and glycolytic pathways.

Warburg phenomenon refers to the development of unique metabolic patterns during the growth of tumor cells. This study stratified gastric cancer into prognostic metabolic subgroups according to changes in gene expressions related to glycolysis and cholesterol synthesis. The RNA-seq expression data, single nucleotide variants (SNV), short insertions and deletions (InDel) mutation data, copy number variation (CNV) data and clinical follow-up information data of gastric cancer tissues were downloaded from The Cancer Genome Atlas (TCGA) database. ConsensusClusterPlus was used to stratify the metabolic subtypes of gastric cancer. Four metabolic subtypes (Cholesterogenic, Glycolytic, Mixed and Quiescent) of gastric cancer were identified, and patients with cholesterogenic tumors had the longest disease-specific survival (DSS). Genome-wide analysis showed that aberrant amplification of TP53 and MYC in gastric cancer was associated with abnormal cholesterol anabolic metabolism. The mRNA levels of mitochondrial pyruvate carriers 1 and 2 (MPC1/2) differed among the four subtypes. Tumors in the glycolytic group showed a higher PDCD1. A genomic signature based on tumor metabolism of different cancer types was established. This study showed that genes related to glucose and lipid metabolism play an important role in gastric cancer and facilitate a personalized treatment of gastric cancer.

Visible-light-driven peroxymonosulfate activation in photo-electrocatalytic system using hollow-structured Pt@CeO2@MoS2 photoanode for the degradation of pharmaceuticals and personal care products.

In this study, we constructed an innovative photo-electrocatalysis-assisted peroxymonosulfate (PEC/PMS) system to degrade pharmaceuticals and personal care products (PPCPs). A hollow-structured photoanode (i.e., Pt@CeO2@MoS2) was specifically synthesized as a photoanode to activate PMS in the PEC system. As proof of concept, the Pt@CeO2@MoS2 photoanode exhibited superior degradation performance toward carbamazepine (CBZ) with PMS assistance. Specifically, the kinetic constant of PEC/PMS (k = 0.13202 min-1) could be enhanced about 87.4 times compared to that of the PEC system (0.00151 min-1) alone. The PMS activation mechanism revealed that the synergistic effect between the hollow material and the change of surface valence states (Ce3+ to Ce4+) and (Mo4+ to Mo6+) contribute to enhancing the degradation efficiency of the visible-light-driven PEC/PMS process. The scavenger testing and EPR showed that 1O2, O2•-, SO4•- and •OH play dominant roles in the SR-AOPs. Furthermore, the applicability of Pt@CeO2@MoS2 used in SR-AOPs was systematically investigated regarding of the reaction parameters and identification of intermediates and dominant radicals as well as the mineralization rate and stability. The outcomes of this study can provide a new platform for environmental remediation.

N-doped graphitic C3N4 nanosheets decorated with CoP nanoparticles: A highly efficient activator in singlet oxygen dominated visible-light-driven peroxymonosulfate activation for degradation of pharmaceuticals and personal care products.

CoP nanoparticle-loaded N-doped graphitic C3N4 nanosheets (CoP/N-g-C3N4) were fabricated via a facile three-step method to degrade pharmaceuticals and personal care products (PPCPs) via a visible-light-driven (VLD) peroxymonosulfate (PMS) activation system. 2 ppm carbamazepine (CBZ) can be removed completely within 10 min by the VLD-PMS system with a kinetic constant of k = 0.29128 min-1, as 25.8 times compared to that under dark conditions (k = 0.01128 min-1). The experimental and theoretical results showed that the doped graphitic N atoms could modulate the electronic properties of the g-C3N4 nanosheets. Subsequently, the Density Functional Theory (DFT) explained that CoP showed preference to bonding with the nitrogen atoms involved in the newly formed NË­N bond, and the Co‒N bond dramatically enhanced the transfer of photo-generated electrons from the N-g-C3N4 nanosheets. Electron paramagnetic resonance (EPR) tests show that singlet oxygen (1O2) plays a leading role in this case. Moreover, PMS molecules are also tended to be absorbed onto the electron-deficient carbon atoms near the newly formed NË­N bonds for PMS reduction, synergistically enhancing the degradation efficiency for CBZ and benzophenone-3 (BZP). The newly established VLD-PMS activation system was shown to treat the actual sewage in Hong Kong sewage treatment plants (STPs) very well. This work supplements the fundamental theory of radical and non-radical pathways in the sulfate radical (SO4•-)-based advanced oxidation process (SR-AOP) for environmental cleanup purposes.

Hollow Fe3O4/carbon with surface mesopores derived from MOFs for enhanced lithium storage performance.

Hollow metal-organic frameworks (MOFs) and their derivatives have attracted more and more attention due to their high specific surface area and perfect morphological structure, which determine their large potential application in energy storage and catalysis fields. However, few researchers have carried out further modification on the outer shell of hollow MOFs, such as the perforation modification, which will endow hollow nanomaterials derived from MOFs with multifunctionality. In this paper, hollow MOFs of MIL-53(Fe) with perforated outer surface are successfully synthesized by using SiO2 nanospheres as the template via a self-assembly process induced by the coordination polymerization. The tightly packed mesopore structure makes the carbon outer shell of MOFs thinner, thus realizing the in-situ transformation from MOFs to hollow Fe3O4/carbon, which exhibits perfect capacity approaching 1270 mA h g-1 even after 200 cycles at 0.1 A g-1, as an anode material in lithium ion batteries (LIBs) application. This research provides a new strategy for the design and preparation of MOFs and their derivatives with multifunctionality for the energy applications.

Siva­1 regulates multidrug resistance of gastric cancer by targeting MDR1 and MRP1 via the NF­κB pathway.

Siva­1 is a well­known anti­apoptosis protein that serves a role in multiple types of cancer cells. However, whether Siva­1 affects multidrug resistance via the NF­κB pathway in gastric cancer is currently unknown. The present study aimed to determine the possible involvement of Siva­1 in gastric cancer anticancer drug resistance in vitro. A vincristine (VCR)­resistant KATO III/VCR gastric cancer cell line with stable Siva­1 overexpression was established. The protein expression levels of Siva­1, NF­κB, multidrug resistance 1 (MDR1) and multidrug resistance protein 1 (MRP1) were detected via western blotting. The effect of Siva­1 overexpression on anticancer drug resistance was assessed by measuring the 50% inhibitory concentration of KATO III/VCR cells to VCR, 5­fluorouracil and doxorubicin. The rate of doxorubicin efflux and apoptosis were detected by flow cytometry. Additionally, colony formation, wound healing and Transwell assays were used to detect the proliferation, migration and invasion of cells, respectively. The results of the current study revealed that the Siva­1­overexpressed KATO III/VCR gastric cancer cells exhibited a significantly decreased sensitivity to VCR, 5­fluorouracil and doxorubicin. The results of flow cytometry revealed that the percentage of apoptotic cells decreased following overexpression of Siva­1. The colony formation assay demonstrated that cell growth and proliferation were significantly promoted by Siva­1 overexpression. Additionally, Siva­1 overexpression increased the migration and invasion of KATO III/VCR cells in vitro. Western blot analysis determined that Siva­1 overexpression increased NF­κB, MDR1 and MRP1 levels. The current study demonstrated that overexpression of Siva­1, which functions as a regulator of MDR1 and MRP1 gene expression in gastric cancer cells via promotion of NF­κB expression, inhibited the sensitivity of gastric cancer cells to certain chemotherapies. These data provided novel insight into the molecular mechanisms of gastric cancer, and may be of significance for the clinical diagnosis and therapy of patients with gastric cancer.

Research progress of photocatalytic sterilization over semiconductors.

Considering the situation that environmental issues become more serious day by day, research on practical applications of semiconductor photocatalysis for environmental purification has attracted broad attention, including the remediation of water pollution, air contaminant treatment, photocatalytic sterilization etc., among which the application of semiconductor photocatalytic properties for the disinfection of soil surfaces, air and water, such as TiO2, is of great interest. In this paper, we give an overview of the photocatalytic antibacterial ability of TiO2 and other novel carbon material semiconductors. We have introduced the background information of photocatalytic disinfection and the disinfection mechanism of pure TiO2. Furthermore, other modified TiO2 sterilization materials are listed, such as those with doping modification. In addition, some novel carbon based nanomaterials are discussed as well in this review, for instance, g-C3N4, carbon nanotubes and graphene nanosheets. Finally, we present an outlook over two dimensional (2D) materials and coupling techniques based on the combination of photocatalysis and other sterilization technologies.

Molybdenum sulfide Co-catalytic Fenton reaction for rapid and efficient inactivation of Escherichia coli.

As a typical advanced oxidation technology, the Fenton reaction has been employed for the disinfection, owing to the strong oxidizability of hydroxyl radicals (·OH). However, the conventional Fenton system always exhibits a low H2O2 decomposition efficiency, leading to a low production yield of ·OH, which makes the disinfection effect unsatisfactory. Herein, we develop a molybdenum sulfide (MoS2) co-catalytic Fenton reaction for rapid and highly efficient inactivation of Escherichia coli K-12 (E. coli) and Staphylococcus aureus (S. aureus). As a co-catalyst in the Fe(II)/H2O2 Fenton system, MoS2 can greatly facilitate the Fe(III)/Fe(II) cycle reaction by the exposed Mo4+ active sites, which significantly improves the H2O2 decomposition efficiency for the ·OH production. As a result, the MoS2 co-catalytic Fenton system can reach up to 83.37% of inactivation rate of E. coli just in 1 min and 100% of inactivation rate within 30 min, which increased by 2.5 times than that of the conventional Fenton reaction. Furthermore, the ·OH as the primary reactive oxygen species (ROS) in MoS2 co-catalytic Fenton reaction was measured and verified by electron paramagnetic resonance (EPR) and photoluminescence (PL). It is demonstrated an increased amount of ·OH generated from the decomposition of H2O2 in the presence of MoS2, which is responsible for the rapid and efficient inactivation of E. coli and S. aureus. This study provides a new perspective for rapid and highly efficient inactivation of bacteria in environmental remediation.

Protection of rat intestinal epithelial cells from ischemia/reperfusion injury by (D-Ala2, D-Leu5)-enkephalin through inhibition of the MKK7-JNK signaling pathway.

Previous studies have demonstrated that (D­Ala2, D­Leu5)­enkephalin (DADLE) protects rats from hepatic ischemia/reperfusion (I/R) injury. In the present study, DADLE was also observed to alleviate IR­induced intestinal epithelial cell injury in rats by inhibiting mitogen­activated protein kinase kinase 7 (MKK7)­c­Jun N­terminal kinase (JNK) pathway signaling. To investigate the protective effect of DADLE on hypoxia/reoxygenation injury in rat intestinal epithelial cells, rat intestinal epithelial cells were treated with different concentrations of DADLE, following which the cell survival rate was determined using a tetrazolium (MTT) colorimetric assay, and apoptosis was determined using flow cytometry. To confirm whether the protective effect of DADLE was due to its effect on MKK7­JNK signaling, the phosphorylation levels of MKK7 and JNK were analyzed using western blot analysis following treatment with different concentrations of DADLE. The results demonstrated that, following treatment with DADLE, the survival rate of the rat intestinal cells subjected to I/R­induced injury increased significantly and the apoptotic rate decreased in a concentration­dependent manner. In addition, the levels of phosphorylated MKK7 and JNK decreased in a concentration­dependent manner following treatment with DADLE. Silencing the gene expression of MKK7 using small interfering RNA prior to DADLE treatment resulted in a reduction in the protective effects of DADLE on the rat intestinal epithelial cells subjected to I/R injury. Collectively, the results of the present study demonstrated that the protective effects of DADLE in I/R injury in rat intestinal cells occurred through inhibition of the MKK7­JNK pathway.

[Risk factors associated with anastomotic leak in patients with Crohn disease undergoing bowel resections].

OBJECTIVE: To investigate the risk factors and the prevention management of anastomotic leak in patients with Crohn disease undergoing bowel resections. METHODS: Clinical data of 91 patients with Crohn disease undergoing intestinal resection from 1990 to 2010 were analyzed retrospectively. Logistic regression analysis was used to assess the risk factors of anastomotic leak. RESULTS: A total of 120 intestinal anastomosis were performed in 91 patients, and anastomosis leak occurred in 14 patients (11.7%). Univariate analysis showed that operative timing (emergency or elective surgery), anastomosis type (side-to-side or end to end and end-to-side), operative time (≥3 h or <3 h), methods of anastomosis (handsewn or stapled) were the risk factors for anastomotic leak (P<0.05). Multivariate analysis revealed that emergency surgery (OR=3.891, 95%CI:1.332-13.692), end to end and end-to-side anastomosis (OR=3.236, 95%CI:1.165-11.950), handsewn anastomosis (OR=5.715, 95%CI:1.454-17.328) were independent risk factors of anastomotic leak. CONCLUSION: Avoiding emergency operation, use of side to side anastomosis, and application of stapling may lower the incidence of postoperative anastomotic leak in patients with Crohn disease undergoing bowel resections.