Performance of CO_2 absorption in a diameter-varying spray tower

The application of spray towers for CO_2 capture is a development trend in recent years. However, most of the previous jobs were conducted in a cylindrical tower by using a single spray nozzle, whose configuration and performance is not good enough for industrial application. To solve this problem, the present work proposed a diameter-varying spray tower and a new spray mode of dual-nozzle opposed impinging spray to enhance the heat and mass transfer of CO_2 absorption process. Experiments were performed to investigate the mass transfer performance (in terms of the CO_ 2 removal rate (η) and the overall mass transfer coefficient (K_Ga_e)) of the improved spray tower under various operating conditions. Experimental results showed that the liquid to gas ratio and mole ratio of MEA to CO_2 are major factors, which affect the absorption performance and the maximums of η and (K_Ga_e that are 94.0% and 0.574 kmol·m^(-3)·h^(-1)·kP a^(-1), respectively, under the experimental conditions. Furthermore, new correlations to predict the mass transfer coefficient of the proposed spray tower are developed in various CO_2 concentrations with a Pearson Correlation Coefficient over 90%.

Characterizing the catalyst fluidization with field synergy to improve the amine absorption for CO2 capture

There are great interests to capture the CO2 to control the greenhouse gas emission.Amine absorption of CO2 is being taken as an effective way to capture CO2 in industry.However,the amine absorption of CO2 is cost-ineffective due to great energy consumption and solution consumption.In order to reduce the capture cost,catalyst fluidization is proposed here to intensify the mass transfer and heat transfer.Catalyst fluidization with field synergy and DFT model is developed by incorporating the effects of catalyst reaction kinetics,drag force and multi-field into the mass transfer,heat transfer,fluid flow and catalyst collision.Experiments with an improved distributor are performed well to validate the model.The reaction kinetics is determined by the DFT simulation and experiment.The mass transfer coefficient in the fluidized reactor is identified as 17%higher than the conventional packed reactor.With the field synergy of catalyst fluidization,the energy consumption for CO2 desorption is reduced by 9%.Stepwise operation and inclination reactor are used to improve catalyst fluidization process.

O2血清型肺炎克雷伯氏菌多糖结合疫苗的生物合成

本研究旨在利用微生物体内合成肺炎克雷伯氏菌(Klebsiella pneumoniae,Kp)多糖结合疫苗并研究其保护效果。通过敲除Kp O抗原连接酶基因waaL阻断其LPS合成,再向缺失株中导入糖基工程载体,使细菌能够在体内合成糖蛋白,并将该糖蛋白免疫小鼠后评价其保护效果。结果表明,在构建的KpwaaL缺失株中导入糖基工程载体后,底物蛋白重组霍乱毒素B亚单位rCTB (Recombinant cholera toxin B subunit)能够被O糖化,从而得到糖蛋白;动物实验结果显示该疫苗能刺激小鼠产生较高的抗体效价,试验组小鼠攻毒后一周存活率可达75%。这种生物合成方法制备的多糖结合疫苗有望成为针对肺炎克雷伯氏菌的新型候选疫苗。

Pooled Plasmid Sequencing Reveals the Relationship Between Mobile Genetic Elements and Antimicrobial Resistance Genes in Clinically Isolated Klebsiella pneumoniae

Plasmids remain important microbial components mediating the horizontal gene transfer(HGT)and dissemination of antimicrobial resistance.To systematically explore the relationship between mobile genetic elements(MGEs)and antimicrobial resistance genes(ARGs),a novel strategy using single-molecule real-time(SMRT)sequencing was developed.This approach was applied to pooled conjugative plasmids from clinically isolated multidrug-resistant(MDR)Klebsiella pneumoniae from a tertiary referral hospital over a 9-month period.The conjugative plasmid pool was obtained from transconjugants that acquired antimicrobial resistance after plasmid conjugation with 53 clinical isolates.The plasmid pool was then subjected to SMRT sequencing,and 82 assembled plasmid fragments were obtained.In total,124 ARGs(responsible for resistance to b-lactam,fluoroquinolone,and aminoglycoside,among others)and 317 MGEs[including transposons(Tns),insertion sequences(ISs),and integrons]were derived from these fragments.Most of these ARGs were linked to MGEs,allowing for the establishment of a relationship network between MGEs and/or ARGs that can be used to describe the dissemination of resistance by mobile elements.Key elements involved in resistance transposition were identified,including IS26,Tn3,IS903 B,ISEcp1,and ISKpn19.As the most predominant IS in the network,a typical IS26-mediated multi-copy composite transposition event was illustrated by tracing its flanking 8-bp target site duplications(TSDs).The landscape of the pooled plasmid sequences highlights the diversity and complexity of the relationship between MGEs and ARGs,underpinning the clinical value of dominant HGT profiles.

Recovery of waste heat in cement plants for the capture of CO2

Large amounts of energy are consumed during the manufacturing of cement especially during the calcination process which also emits large amounts of CO2. A large part of the energy used in the making of cement is released as waste heat. A process to capture CO2 by integrating the recovery and utilization of waste heat has been designed. Aspen Plus software was used to calculate the amount of waste heat and the efficiency of energy utilization. The data used in this study was based on a dry process cement plant with a 5-stage preheater and a precalciner with a cement output of 1 Mt/y. According to the calculations： 1） the generating capacity of the waste heat recovery system is 4.9MW. 2） The overall CO2 removal rate was as high as 78.5%. 3） The efficiency of energy utilization increased after the cement producing process was retrofitted with this integrated design.

Expert Consensus on Diagnosis and Treatment of End-Stage Liver Disease Complicated with Infections

End-stage liver disease(ESLD)is a life-threatening clinical syndrome that markedly increases mortality in patients with infections.In patients with ESLD,infections can induce or aggravate the occurrence of liver decompensation.Consequently,infections are among the most common complications of disease progression.There is a lack of working procedure for early diagnosis and appropriate management for patients with ESLD complicated by infections as well as local and international guidelines or consensus.This consensus assembled up-to-date knowledge and experience across Chinese colleagues,providing data on principles as well as working procedures for the diagnosis and treatment of patients with ESLD complicated by infections.

Bautype: Capsule and Lipopolysaccharide Serotype Prediction for Acinetobacter baumannii Genome

Acinetobacter baumannii has three clusters of genes for polysaccharide synthesis.Capsular polysaccharides and lipopolysaccharides are major virulence determinants in many Gram-negative bacteria,and play key roles in the overall fitness and virulence in A.baumannii,meanwhile poly-beta-1-6-N-acetylglucosamine was critical for biofilm formation.A variety of studies have been conducted which focused on the surveillance of antimicrobial resistance genes and clones in A.baumannii.However,a tool to perform serotype prediction in A.baumannii is still lacking.Here we present Bautype,a tool for whole genome sequencingbased K and O locus typing in A.baumannii.Using Bautype,users can upload and analyze the genome assembled in a web browser,with the results being displayed in a tabular or graphical format.We demonstrated the high accuracy of predicting K and O locus diversity using Bautype when analyzing more than 3000 A.baumannii genomes.Using our software,we were able to analyze K and O locus diversity among 593 genomes belonging to ST208(3 K and 8 O).These diverse loci can serve as epidemiological markers for Multi-drug Resistance(MDR)strain subtyping.We also identified 45 novel O locus types.Our findings highlight the importance in monitoring the capsule type and LOS of A.baumannii strains for which Bautype is a tailored clinical software.Bautype is available at http://BauType.net.