MnO2-decorated N-doped carbon nanotube with boosted activity for low-temperature oxidation of formaldehyde

Low-temperature oxidative degradation of formaldehyde (HCHO) using non-noble metal catalysts is challenging. Herein, novel manganese dioxide (MnO2)/N-doped carbon nanotubes (NCNT) composites were prepared with varying MnO2 content. The surface properties and morphologies were analyzed using X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and transmission electron microscope (TEM). Comparing with MnO2/carbon nanotubes (CNTs) catalyst, the 40% MnO2/NCNT exhibited much better activity and selectivity for HCHO oxidation, mineralizing 95% of HCHO (at 100 ppm) into CO2 at 30 °C at a gas hourly space velocity (GHSV) of 30,000 mL h-1  g-1. Density functional theory (DFT) calculation was used to analyze the difference in the catalytic activity of MnO2 with CNTs and NCNT carrier. It was confirmed that the oxygen on NCNT was more active than CNTs, which facilitated the regeneration of MnO2. This resulted in remarkably boosted activity for HCHO oxidation. The present work thus exploited an inexpensive approach to enhance the catalytic activity of transition metal oxides via depositing them on a suitable support

Study on the waterlogging operation effects of InfoWorks ICM dispatching strategies

In this paper, we select the H river basin of a city in northern China as the test section of deep tunnel construction project and use InfoWorks ICM to establish a two-dimensional hydraulic model in the basin. The basin is divided into 9 subsystems from T1 to T9 for ease of research, study the waterlogging control effect of the optimal dispatching operation strategies of deep tunnel in the basin.The results show that the waterlogging control effect meets the construction target of deep tunnel project, after the drainage of deep tunnel, the rainfall recurrence period of waterlogging risk of each subsystem is increased from more than once every year to once every ten years

Dynamics of Cohen-Grossberg Neural Networks with Mixed Delays and Impulses

Impulsive Cohen-Grossberg neural networks with bounded and unbounded delays (i.e., mixed delays) are investigated. By using the Leray-Schauder fixed point theorem, differential inequality techniques, and constructing suitable Lyapunov functional, several new sufficient conditions on the existence and global exponential stability of periodic solution for the system are obtained, which improves some of the known results. An example and its numerical simulations are employed to illustrate our feasible results

Construction and application of high-quality genome-scale metabolic model of Zymomonas mobilis to guide rational design of microbial cell factories

High-quality genome-scale metabolic models (GEMs) could play critical roles on rational design of microbial cell factories in the classical Design-Build-Test-Learn cycle of synthetic biology studies. Despite of the constant establishment and update of GEMs for model microorganisms such as Escherichia coli and Saccharomyces cerevisiae, high-quality GEMs for non-model industrial microorganisms are still scarce. Zymomonas mobilis subsp. mobilis ZM4 is a non-model ethanologenic microorganism with many excellent industrial characteristics that has been developing as microbial cell factories for biochemical production. Although five GEMs of Z. mobilis have been constructed, these models are either generating ATP incorrectly, or lacking information of plasmid genes, or not providing standard format file. In this study, a high-quality GEM iZM516 of Z. mobilis ZM4 was constructed. The information from the improved genome annotation, literature, datasets of Biolog Phenotype Microarray studies, and recently updated Gene-Protein-Reaction information was combined for the curation of iZM516. Finally, 516 genes, 1389 reactions, 1437 metabolites, and 3 cell compartments are included in iZM516, which also had the highest MEMOTE score of 91% among all published GEMs of Z. mobilis. Cell growth was then predicted by iZM516, which had 79.4% agreement with the experimental results of the substrate utilization. In addition, the potential endogenous succinate synthesis pathway of Z. mobilis ZM4 was proposed through simulation and analysis using iZM516. Furthermore, metabolic engineering strategies to produce succinate and 1,4-butanediol (1,4-BDO) were designed and then simulated under anaerobic condition using iZM516. The results indicated that 1.68 mol/mol succinate and 1.07 mol/mol 1,4-BDO can be achieved through combinational metabolic engineering strategies, which was comparable to that of the model species E. coli. Our study thus not only established a high-quality GEM iZM516 to help understand and design microbial cell factories for economic biochemical production using Z. mobilis as the chassis, but also provided guidance on building accurate GEMs for other non-model industrial microorganisms

Development of the thermophilic fungus Myceliophthora thermophila into glucoamylase hyperproduction system via the metabolic engineering using improved AsCas12a variants

Abstract Background Glucoamylase is an important enzyme for starch saccharification in the food and biofuel industries and mainly produced from mesophilic fungi such as Aspergillus and Rhizopus species. Enzymes produced from thermophilic fungi can save the fermentation energy and reduce costs as compared to the fermentation system using mesophiles. Thermophilic fungus Myceliophthora thermophila is industrially deployed fungus to produce enzymes and biobased chemicals from biomass during optimal growth at 45 °C. This study aimed to construct the M. thermophila platform for glucoamylase hyper-production by broadening genomic targeting range of the AsCas12a variants, identifying key candidate genes and strain engineering. Results In this study, to increase the genome targeting range, we upgraded the CRISPR-Cas12a-mediated technique by engineering two AsCas12a variants carrying the mutations S542R/K607R and S542R/K548V/N552R. Using the engineered AsCas12a variants, we deleted identified key factors involved in the glucoamylase expression and secretion in M. thermophila, including Mtstk-12, Mtap3m, Mtdsc-1 and Mtsah-2. Deletion of four targets led to more than 1.87- and 1.85-fold higher levels of secretion and glucoamylases activity compared to wild-type strain MtWT. Transcript level of the major amylolytic genes showed significantly increased in deletion mutants. The glucoamylase hyper-production strain MtGM12 was generated from our previously strain MtYM6 via genetically engineering these targets Mtstk-12, Mtap3m, Mtdsc-1 and Mtsah-2 and overexpressing Mtamy1 and Mtpga3. Total secreted protein and activities of amylolytic enzymes in the MtGM12 were about 35.6-fold and 51.9‒55.5-fold higher than in MtWT. Transcriptional profiling analyses revealed that the amylolytic gene expression levels were significantly up-regulated in the MtGM12 than in MtWT. More interestingly, the MtGM12 showed predominantly short and highly bulging hyphae with proliferation of rough ER and abundant mitochondria, secretion vesicles and vacuoles when culturing on starch. Conclusions Our results showed that these AsCas12a variants worked well for gene deletions in M. thermophila. We successfully constructed the glucoamylase hyper-production strain of M. thermophila by the rational redesigning and engineering the transcriptional regulatory and secretion pathway. This targeted engineering strategy will be very helpful to improve industrial fungal strains and promote the morphology engineering for enhanced enzyme production

Additional file 1 of Preoperative risk factors and cumulative incidence of temporary ileostomy non-closure after sphincter-preserving surgery for rectal cancer: a meta-analysis

Supplementary Material

Video_2_Effectiveness and safety of self-pulling and latter transection reconstruction in totally laparoscopic right hemicolectomy.mp4

BackgroundLaparoscopic right hemicolectomy is a standard treatment modality for right colon cancer. However, performing intracorporeal anastomosis (IA) for totally laparoscopic right hemicolectomy (TLRH) remains a challenge for some surgeons. To simplify IA in TLRH we used self-pulling and latter transection (SPLT) reconstruction in TLRH, and compared this procedure with overlap IA and laparoscopy-assisted right hemicolectomy (LARH) in order to evaluate its safety and effectiveness.MethodsPatients with right colon cancer who underwent SPLT-TLRH, TLRH with overlap IA or LARH between July 2019 and June 2023 were evaluated retrospectively. Basic information, oncological features, perioperative outcomes, and postoperative complications were compared between groups.ResultsIn total, 188 patients with right colon cancer that underwent SPLT-TLRH (n = 60), TLRH(n=21) or LARH (n = 107) were included in the study. No patient required conversion to open surgery. The operation time in SPLT-TLRH group was significantly shorter than that in TLRH group (PConclusionWe introduced SPLT to TLRH. The SPLT-TLRH group demonstrated better short-term outcomes. Therefore, we believe that SPLT reconstruction is effective and safe in TLRH for right colon cancer, and can simplify reconstruction.</p

Video_1_Effectiveness and safety of self-pulling and latter transection reconstruction in totally laparoscopic right hemicolectomy.mp4

BackgroundLaparoscopic right hemicolectomy is a standard treatment modality for right colon cancer. However, performing intracorporeal anastomosis (IA) for totally laparoscopic right hemicolectomy (TLRH) remains a challenge for some surgeons. To simplify IA in TLRH we used self-pulling and latter transection (SPLT) reconstruction in TLRH, and compared this procedure with overlap IA and laparoscopy-assisted right hemicolectomy (LARH) in order to evaluate its safety and effectiveness.MethodsPatients with right colon cancer who underwent SPLT-TLRH, TLRH with overlap IA or LARH between July 2019 and June 2023 were evaluated retrospectively. Basic information, oncological features, perioperative outcomes, and postoperative complications were compared between groups.ResultsIn total, 188 patients with right colon cancer that underwent SPLT-TLRH (n = 60), TLRH(n=21) or LARH (n = 107) were included in the study. No patient required conversion to open surgery. The operation time in SPLT-TLRH group was significantly shorter than that in TLRH group (PConclusionWe introduced SPLT to TLRH. The SPLT-TLRH group demonstrated better short-term outcomes. Therefore, we believe that SPLT reconstruction is effective and safe in TLRH for right colon cancer, and can simplify reconstruction.</p