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Quorum quenching (QQ) enzymes, which degrade signaling molecules so as to disrupt the quorum sensing signaling process, have drawn much attention as alternative antimicrobial agents. However, the screening methods for evolution of such enzymes through constructing genetic circuits remain a challenge for its relatively high false positive rates caused by the higher basal expression level of the naturally acquired promoter. Thus, we presented an improved genetic circuit by introducing an artificial hybrid promoter PluxI-lacO combining PlacO originated from lactose promoter with QS regulatory promoter PluxI to control the expression of reporter gene rfp. Herein, we investigated the effect of various expression strengths of suppressive protein LacI and signaling molecule AHL on the expression of rfp. We found that the effect AHL exerted on the expression of rfp outweighed that from IPTG. The results also demonstrated that our genetic circuit could achieve the lower basal expression level of reporter gene and could respond to the expression of AiiA. The resulting circuits show the potential for screening the evolved AiiA more efficiently by virtue of inherent low basal expression level.

Disconnected pancreatic duct syndrome (DPDS) is an important and common complication of acute necrotizing pancreatitis. Endoscopic approach has been established as the first-line treatment for pancreatic fluid collections (PFCs) with less invasion and satisfactory outcome. However, the presence of DPDS significantly complicates the management of PFC; besides, there is no standardized treatment for DPDS. The diagnosis of DPDS presents the first step of management, which can be preliminarily established by imaging methods including contrast-enhanced computed tomography, ERCP, magnetic resonance cholangiopancreatography (MRCP), and EUS. Historically, ERCP is considered as the gold standard for the diagnosis of DPDS, and secretin-enhanced MRCP is recommended as an appropriate diagnostic method in existing guidelines. With the development of endoscopic techniques and accessories, the endoscopic approach, mainly including transpapillary and transmural drainage, has been developed as the preferred treatment over percutaneous drainage and surgery for the management of PFC with DPDS. Many studies concerning various endoscopic treatment strategies have been published, especially in the recent 5 years. Nonetheless, existing current literature has reported inconsistent and confusing results. In this article, the latest evidence is summarized to explore the optimal endoscopic management of PFC with DPDS.

Background & Aim: Exosomes are effective mediators of cell-to-cell interactions and carry many regulatory molecules, including miRNAs, that can play crucial roles in diverse fundamental biological processes. However, to date, no study has reported macrophage exosomal involvement in the development of inflammatory bowel disease (IBD). This study investigated the specific miRNAs in macrophage-derived exosomes in IBD and the potential molecular mechanism. Methods: Dextran sulfate sodium (DSS) was used to generate IBD mice. The supernatants of murine bone marrow-derived macrophages (BMDMs) with or without lipopolysaccharide (LPS) were collected for exome isolation and miRNA sequencing. Lentiviruses were used to modify miRNA expression and further investigate the role of macrophage-derived exosomal miRNAs. In vitro, both mouse and human organoids were applied to a Transwell system in co-culture with BMDMs as a cellular IBD-related challenge.Results: Here, we show that LPS-induced macrophages can release exosomes containing various miRNAs, aggravating IBD. We analyzed miRNA sequencing of macrophage-derived exosomes, and miR-223 was selected for further study. In vivo, exosomes with high miR-223 expression contributed to the exacerbation of intestinal barrier dysfunction, which was further verified in both mouse and human colon organoids. Furthermore, time-dependent analysis of the mRNAs of DSS-induced colitis mouse tissue combined with miR-223 target gene prediction was performed to select the candidate gene, and the barrier-related factor TMIGD1 was identified.Conclusion: Collectively, these data indicated that macrophage-derived exosomal miR-223 played a novel role in intestinal barrier dysfunction by inhibiting TMIGD1 in the progression of DSS-induced colitis.

IntroductionCC chemokine receptor 5 (CCR5) and the NF-κB signaling pathway play important roles in the pathophysiology of inflammatory bowel disease (IBD). Previously, we synthesized two peptides (GH and HY peptides) that specifically bind to the first and the second extracellular loops (ECL1 and ECL2, respectively) of CCR5 and preliminarily found an inhibitory effect of these peptides on colitis. However, the specific mechanism by which these two peptides regulate trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats remains unclear.Material and methodsExperimental colitis was induced by 5% TNBS. CCR5 antagonist peptides were administered intravenously once a day for a week. Histological evaluation, real-time PCR, western blotting and correlation analysis were performed to examine the effects of the CCR5 binding peptides on the infiltration of inflammatory cells and the NF-κB signaling pathway.ResultsGH and HY peptides ameliorated mucosal damage and reduced the infiltration of neutrophils, lymphocytes and macrophages in experimental colitis (P < 0.05). The expression of NF-κB-related genes, including p105, p100, IKK and TNF-α, was reduced after GH and HY peptide administration (P < 0.01), and the protein level of TNF-α and the phosphorylation of IKK, IκBα and p65 were also suppressed. Furthermore, CCR5 antagonist peptides inhibited nuclear translocation of p65. Spearman correlation analysis showed that the infiltration of inflammatory cells was significantly correlated with the NF-κB pathway.ConclusionsAntagonistic peptides that specifically bind to ECL1 and ECL2 of CCR5 inhibit the infiltration of neutrophils, lymphocytes and macrophages in the colonic mucosa of SD rats with TNBS-induced colitis via regulation of the NF-κB signaling pathway.

Millions of tons of collagen-rich bovine bone are produced as byproducts of the consumption of beef. Hydrolyzing bovine bone collagen (BBC) is an effective measure for both increasing its added value and protecting the environment. In this study, a kind of recombinant bacterial collagenase mining from Bacillus cereus was successfully performed and applied to hydrolyze BBC to collagen-soluble peptides (CPP). Response surface methodology (RSM) was applied to optimize the processing conditions of antioxidant CPP, attaining a distinguished ABTS free radical scavenging activity of 99.21 ± 0.35% while keeping DPPH free radical scavenging activity and reducing power at high levels under the optimal condition. Furthermore, we identified five new antioxidant peptides by LC-MS/MS with typical collagen repeated Gly-Xaa-Yaa sequence units within the CPP. These results suggest that our recombinant collagenase is a powerful tool for degrading collagen and the CPP are promising candidates for antioxidant and related functional food applications.

In this paper, a risk explicit interval two-stage programming (REITSP) model was proposed for supporting the regional electricity generation expansion with renewable portfolio standard (RPS) constraint. It could effectively tackle multiple uncertainties expressed as interval numbers. But unlike the traditional interval two-stage programming model, the proposed REITSP model could provide an explicit trade-off information between system cost and risk for decision makers with different risk preferences. It could minimize the total system cost, as well as the decision risk according to the aspiration risk level of decision maker. The developed REITSP model was applied to the case study in Guangdong Province, China for its long-term electricity system planning. Crisp solutions under different aspiration risk levels for varying RPS targets were obtained and analyzed. The results showed that according to the current available renewable energy and affordable construction speed, the maximum RPS target for Guangzhou Province during 2016–2025 should be 17%. Higher RPS level would promote the renewable energy generation, especially solar power; meanwhile, it would reduce the CO2 emission and the imported electricity, but with greater investment cost. The obtained results and trade-off information would be valuable for the optimal long-term electricity system expansion planning when facing future uncertain situation.

Quorum quenching (QQ) enzymes, which degrade signaling molecules so as to disrupt the quorum sensing signaling process, have drawn much attention as alternative antimicrobial agents. However, the screening methods for evolution of such enzymes through constructing genetic circuits remain a challenge for its relatively high false positive rates caused by the higher basal expression level of the naturally acquired promoter. Thus, we presented an improved genetic circuit by introducing an artificial hybrid promoter P

Marine engineering equipment manufacturing is one of the most important industries in marine economy, which is listed as the marine strategic emerging industry. After the self-reliance development stage and the introduction of international standards and foreign technology, it is facing challenges to dedicate itself to international market competition. This article reviewed the development of marine engineering equipment manufacturing industry in China, analyzed the international competition situation and discussed the prospects. It is concluded that, marine engineering equipment manufacturing industry of China was undergoing transformation and upgrading stage with the trend towards deep water, large scale and automation in the world, strategies and actions were carried out from the top plan to the company level collaboration, it would make a fast increasing in the near future with the increasing international and domestic needs of deep sea exploit.

Many pilot projects of large-scale distributed energy resources (DER) system have been constructed recent years in China and operation strategies make a great impact on their benefits and further development. This paper presents a multi-objective (joint) optimization model for the large-scale DER system of Guangzhou Higher Education Mega Center to obtain the optimal operation strategies under different daily periods: peak periods, flat periods, and valley periods. The prime mover used in this investigation is a gas-steam combined cycle based on combined gas turbines and steam turbines, and the DER system is evaluated under three different operation optimization modes: joint optimization mode of variable operational cost (VOC) and primary energy rate (PER), VOC optimization mode, and PER optimization mode. The primary energy consumption (PEC), PER, operational costs, and investment benefits of the DER system under different operation strategies of above three optimization modes are evaluated comparing with the buildings using conventional technologies. Results indicate that the VOC optimization mode provides the best combined cooling, heating, and power (CCHP) performance during flat periods by yielding the lowest PEC (133.78 kton/year) and operational cost (million $ 35.98/year), and the joint optimization mode shows the best performance during peak periods by producing the lowest PEC (80.42 kton/year) and similar low operational costs (million $ 21.74/year) to VOC optimization mode (million $ 20.89/year).

China is actively promoting energy saving policies to achieve the commitments promised in Copenhagen. Meanwhile, the relevant energy-saving programs are being implemented in the upstream and downstream of the electric power industry, including energy saving dispatching in the power generation side, and Time-of-Use (TOU) price mechanisms in the user side, etc. In order to optimize the energy efficiency of the power industry chain, it is necessary to implement joint optimization of the generation side and user side. In this paper, considering the constraints such as the user demand for electricity and benefits of the grid company, the joint optimization model of generation side and user side is built, with objective function of minimizing the coal consumption. In the user side, the TOU price is implemented and the fluctuation level of the load curve is reduced by adjusting the tariff of the peak periods and valley periods. In the power generation side, the electricity demand load optimized by TOU in the user side will be balanced in accordance with the principle of energy saving generation dispatching. Optimization results indicate that the response of demand load to TOU price will contribute to achieving energy saving benefits in the generation side.

Based on fuel saving and emission reducing, this study establishes three layers optimization model for time-of-use and interruptible price. At first, a model to minimize total cost, including power purchase cost, emission cost and reserve cost was set up. Based on model 1, the time-of-use price optimization model was put forward afterwards. Finally, the three layers optimization model for time-of-use and interruptible price was established

China’s wind power is primarily distributed in West China which is far away from the load center. Power from these wind farms is difficult to consume, so it needs to be transmitted to East ...

This paper presents a macroscopic view on the prevailing policy and potential issues in respect of the sus- tainable wind power development in China. It starts by analyzing the characteristics of wind power resources and pin-pointing the relationship between the regulatory policies and various economic, taxation, legal and grid integration attributes relating to the wind power development. Then it follows by analyzing the status quo and capabilities of the wind power manufacturing industry in China including its operational efficiency and grid integration standards. The economic and environmental benefits are estimated by relating to the associated costing analysis in respect of the major contributing factors such as manufacturing, opera- tional and financial factors. Results of the associated benefits analysis indicate that the use of the wind power generation helps to save a significant equivalent amount of standard coal consumption resulting to reduction of emission effectively. Finally, the potential of wind power development in China is shown to be affirmative and the sustainable energy policy is effectively implemented in China.