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Carbapenemase is the predominant enzyme in the mechanism leading to Enterobacterales resistance to carbapenems, and the rapid spread of the bla KPC gene is a major public health concern. Here, we describe a carbapenem-resistant Proteus mirabilis strain XH983, which harbored a bla KPC-2 -producing IncN plasmid, isolated from a bloodstream infection. Whole-genome sequencing and bioinformatics analysis were performed to assess the genetic environment of P. mirabilis XH983. Conjugation and transfer experiments were performed and the corresponding strains were confirmed by antimicrobial susceptibility testing. Phylogenetic and comparative genomic analysis were performed to explore the characteristics of carbapenem-resistant P. mirabilis isolates worldwide. P. mirabilis XH983 was isolated from the blood of a patient in Hangzhou, China. The genome of XH983 contained one 4128,916 bp circular chromosome and one 24,225 bp IncN plasmid harboring bla KPC-2. P. mirabilis XH983 had multiple resistance genes, conferring resistance to aminoglycosides [ aph(3')-Ia , aph(3'')-Ib , aph(6)-Id , aac(3)-IId , aadA5 , aadA1 ], β-lactams (bla KPC-2 , bla TEM-1B), phenicol (cat , catA1), sulphonamide/trimethoprim (drfA1 , drfA17 , sul1 , sul2) and tetracycline [ tet(J) ]. The phylogenetic tree showed that XH983 was present in a cluster of 30 isolates, all of which carried bla KPC-2 and most of them came from the same hospital as XH983, indicating the clonal spread of the cluster. We characterized carbapenem-resistant P. mirabilis clinical isolate XH983. The genome sequence of P. mirabilis XH983 provides information about resistance mechanisms of P. mirabilis carrying the bla KPC-2 plasmid and the potential spread of bla KPC-2. [ABSTRACT FROM AUTHOR]

To investigate the molecular events associated with acquiring macrolide resistance genes [ mefE / mel (Mega) or ermB ] in Streptococcus pneumoniae (Spn) during nasopharyngeal colonization. Genomic analysis of 128 macrolide-resistant Spn isolates revealed recombination events in genes of the conjugation apparatus, or the competence system, in strains carrying Tn 916 -related elements. Studies using confocal and electron microscopy demonstrated that during the transfer of Tn 916 -related elements in nasopharyngeal cell biofilms, pneumococcal strains formed clusters facilitating their acquisition of resistance determinants at a high recombination frequency (rF). Remarkably, these aggregates comprise both encapsulated and nonencapsulated pneumococci that span extracellular and intracellular compartments. rF assessments showed similar rates regardless Mega was associated with large integrative and conjugative elements (ICEs) (>23 kb) or not (∼5.4 kb). The rF for Mega Class IV(c) insertion region (∼53 kb) was three orders of magnitude higher than the transformation of the capsule locus. Metabolomics studies of the microenvironment created by colonization of human nasopharyngeal cells revealed a link between the acquisition of ICEs and the pathways involving nicotinic acid and sucrose. Pneumococcal clusters, both extracellular and intracellular, facilitate macrolide resistance acquisition, and ICEs were acquired at a higher frequency than the capsule locus. Metabolic changes could serve as intervention targets. • Recombination hotspots were identified within the Tn 2010 conjugation machinery of Spn CC271 strains. • Extracellular and intracellular clusters of pneumococci facilitate macrolide resistance acquisition. • Macrolide resistance acquisition via recombination is more frequent than classic capsule locus transformation events. • Pneumococci and nasopharyngeal create a microenvironment altering host metabolites, linked to increased macrolide resistance acquisition. [ABSTRACT FROM AUTHOR]

While sodium hypochlorite (NaClO) has long been used to disinfect drinking water, concerns have risen over its use due to causing potentially hazardous byproducts. Catalytic ozonation with metal-free catalysts has attracted increasing attention to eliminate the risk of secondary pollution of byproducts in water treatment. Here, we compared the disinfection efficiency and microbial community of catalytic ozone with a type of metal-free catalyst fluorinated ceramic honeycomb (FCH) and NaClO disinfectants under laboratory- and pilot-scale conditions. Under laboratory conditions, the disinfection rate of catalytic ozonation was 3∼6-fold that of ozone when the concentration of Escherichia coli was 1 × 106 CFU/ml, and all E. coli were killed within 15 s. However, 0.65 mg/L NaClO retained E. coli after 30 min using the traditional culturable approach. The microorganism inactivation results of raw reservoir water disinfected by catalytic ozonation and ozonation within 15 s were incomparable based on the cultural method. In pilot-scale testing, catalytic ozonation inactivated all environmental bacteria within 4 min, while 0.65 mg/L NaClO could not achieve this success. Both catalytic ozonation and NaClO-disinfected methods significantly reduced the number of microorganisms but did not change the relative abundances of different species, i.e., bacteria, viruses, eukaryotes, and archaea, based on metagenomic analyses. The abundance of virulence factors (VFs) and antimicrobial resistance genes (ARGs) was detected few in catalytic ozonation, as determined by metagenomic sequencing. Some VFs or ARGs, such as virulence gene ' FAS-II ' which was hosted by Mycobacterium_tuberculosis , were detected solely by the NaClO-disinfected method. The enriched genes and pathways of cataO 3 -disinfected methods exhibited an opposite trend, especially in human disease, compared with NaClO disinfection. These results indicated that the disinfection effect of catalytic ozone is superior to NaClO, this finding contributed to the large-scale application of catalytic ozonation with FCH in practical water treatment. [Display omitted] • Catalytic O 3 by FCH improves disinfection ratio of E. coli over O 3 about 3∼6-fold. • Catalytic O 3 kills more organisms and unchanges the relative abundance of species. • Catalytic O 3 and NaClO exhibit different effects on the number of VFs and ARGs. • Catalytic O 3 can especially eliminate Mycobacterium_tuberculosis with VF FAS-II. • Catalytic O 3 rather than NaClO can completely eradicate genes of human diseases. [ABSTRACT FROM AUTHOR]

A. baumannii is an important and common clinical pathogen, especially in the intensive care unit (ICU). This study aimed to characterize one hypervirulent A. baumannii strain in a patient with community-acquired pneumonia and herpes simplex type 1 virus infection. Minimum inhibitory concentrations (MICs) were determined using the Kirby-Bauer (K-B) and broth microdilution methods. Galleria mellonella infection model experiment was conducted. Whole-genome sequencing (WGS) was performed using the Illumina and Nanopore platforms. The resistance and virulence determinants were identified using the ABRicate program with ResFinder and the VFDB database. The capsular polysaccharide locus (K locus) and lipooligosaccharide outer core locus (OC locus) were identified using Kleborate with Kaptive. Phylogenetic analyses were conducted using the BacWGSTdb server. A. baumannii XH2146 strain belongs to ST10 Pas and ST447 Oxf. The strain was resistant to cefazolin, ciprofloxacin, and trimethoprim/sulfamethoxazole (TMP-SMX). Bautype and Kaptive analyses showed that XH2146 contains OCL2 and KL49. WGS analysis revealed that the strain harbored bla ADC-76 , bla OXA-68 , ant(3′')-IIa , tet (B), and sul2. Notably, tet (B) and sul2 , both were located within a 114,700-bp plasmid (designated pXH2146–1). Virulence assay revealed A. baumannii XH2146 possessed higher virulence than A. baumannii AB5075 at 12 h. Comparative genomic analysis showed that A. baumannii ST447 strains were mainly isolated from the USA and exhibited a relatively close genetic relationship. Importantly, 11 strains were observed to carry bla OXA-58 ; bla OXA-23 was identified in 11 isolates and three ST447 A. baumannii strains harbored bla NDM-1. Early detection of community-acquired hypervirulent Acinetobacter baumannii strains is recommended to prevent their extensive spread in hospitals. [ABSTRACT FROM AUTHOR]

Objectives: To elucidate the predictors of carbapenem-resistant Klebsiella pneumoniae (CRKP) infection and help clinicians better identify CRKP infection at an early stage.Methods: We conducted a multicentre case-control study of 422 patients with CRKP infection and 948 with carbapenem-susceptible K. pneumoniae (CSKP) infection from March to July 2017. Binary logistic regression was used to identify risk factors for CRKP infection. The subgroups of CRKP respiratory infection, intra-abdominal infection, and bloodstream infection were also evaluated. Patients were followed up for 28 days. Independent risk factors for 28-day crude mortality of CRKP infection were analysed using Cox proportional hazards regression models.Results: Longer stay of hospitalization, stay in the intensive care unit (ICU), previous exposure to antibacterial agents (especially carbapenems, quinolones, aminoglycosides, and tigecycline), invasive procedures, intravascular catheter use, tracheotomy, and admission to ICU in the preceding 90 days were risk factors for CRKP infection. Carbapenem exposure was the only common predictor of different types of CRKP infection. The 28-day crude mortality of CRKP infection was 24.2% and was independently associated with sex, admitted unit, and type of infection.Conclusions: Strict policies for antibiotic use, cautious decisions regarding the implementation of invasive procedures, and careful management of patients with catheters, especially intravascular catheters, are necessary to handle CRKP infection. [ABSTRACT FROM AUTHOR]

Objectives: Community onset urinary tract infections (COUTIs) drew attention recently owing to their increased prevalence and associations with resistant pathogens. The study is aimed at investigating the etiology of COUTIs as well as prevalence and the related risk factors of extended-spectrum β-lactamase (ESBL) in COUTIs in China.Methods: The prospective study was performed in nineteen hospitals during November 1, 2017 and August 31, 2019. Non-duplicated isolates from COUTIs were included. The ESBL phenotypic confirmation test was performed and whole genomes were sequenced for all the ESBL-positive bacteria for further analysis. The risk factors for ESBL-producing bacterial infections were analyzed using binary logistic regression.Results: A total of 1760 COUTI cases were included in this study. Escherichia coli (1332, 75.7%), Klebsiella pneumoniae (110, 6.3%) and Enterococcus faecalis (52, 3.0%) were the top three common pathogens of COUTIs in China. The overall positive rate of ESBLs in Enterobacterales was 37.2% (562/1512). The age (OR=1.007, P = 0.041), solid malignant tumor (OR=1.668, P = 0.016), prostate diseases (OR=2.035, P = 0.010), history of lithotripsy for urinary calculi (OR=2.009, P = 0.030), history of urological surgery (OR=1.869, P = 0.009) and cephalosporin use within 3 months (OR=1.503, P = 0.025) were independent risk factors for ESBL-producing organisms causing COUTIs. The predominant ESBL types were CTX-Ms, among which CTX-M-14, CTX-M-55 and CTX-M-27 were the most common subtypes. ST131 and ST1193 were the predominant sequence types of ESBL-producing E. coli (ESBL-EC). Most of the tested antimicrobial agents showed significantly higher non-susceptible rates in the ESBL positive group as compared with ESBL-negative group (P < 0.05).Conclusions: Enterobacterales, especially E. coli, is the most common pathogen in COUTIs in China and ESBL-producers are highly prevalent. Thus, early prediction depending on risk factors seems to be crucial to determine the appropriate empirical therapy for infections caused by ESBL-producing pathogens. [ABSTRACT FROM AUTHOR]

While traditional culture-dependent methods can effectively detect certain microorganisms, the comprehensive composition of the municipal drinking water (DW) microbiome, including bacteria, archaea, and viruses, remains unknown. Metagenomic sequencing has opened the door to accurately determine and analyze the entire microbial community of DW, providing a comprehensive understanding of DW species diversity, especially in the context of public health concerns during the COVID-19 era. In this study, we found that most of the culturable bacteria and some fecal indicator bacteria, such as Escherichia coli and Pseudomonas aeruginosa , were non-culturable using culture-dependent methods in all samples. However, metagenomic analysis showed that the predominant bacterial species in the DW samples belonged to the phyla Proteobacteria and Planctomycetes. Notably, the genus Methylobacterium was the most abundant in all water samples, followed by Sphingomonas , Gemmata , and Azospirilum. While low levels of virulence-associated factors, such as the Esx-5 type VII secretion system (T7SS) and DevR/S, were detected, only the erythromycin resistance gene erm (X), an rRNA methyltransferase, was identified at low abundance in one sample. Hosts corresponding to virulence and resistance genes were identified in some samples, including Mycobacterium spp. Archaeal DNA (Euryarchaeota , Crenarchaeota) was found in trace amounts in some DW samples. Viruses such as rotavirus, coxsackievirus, human enterovirus, and SARS-CoV-2 were negative in all DW samples using colloidal gold and real-time reverse transcription polymerase chain reaction (RT‒PCR) methods. However, DNA encoding a new order of reverse-transcribing viruses (Ortervirales) and Herpesvirales was found in some DW samples. The metabolic pathways of the entire microbial community involve cell‒cell communication and signal secretion, contributing to cooperation between different microbial populations in the water. This study provides insight into the microbial community and metabolic process of DW in Hangzhou, China, utilizing both culture-dependent methods and metagenomic sequencing combined with bioinformatics tools during the COVID-19 pandemic era. [Display omitted] • Culturable bacteria and viruses are negative in water isolated from COVID-19 era. • Esx-5, DevR/S, and their hosts Mycobacterium spp. were detected by metagenome. • A new order of reverse-transcribing viruses Ortervirales was identified in water. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Recyclable electro-driven process of CO 2 capture and indirect H 2 O electrolysis. • Non-neutral Ni based catalyst was developed to achieve single-atom catalysis. • Catalyst regeneration is achieved with high activity site. • DFT model and energy recovery model are developed. • Energy consumption for H 2 production and CO 2 capture reduced to 0.4 V and 1 GJ/t. Abstract Hydrogen utilization and CO 2 capture significantly improve the environment. In order to reduce the energy penalty of hydrogen production and CO 2 capture, the idea of this work is to integrate the hydrogen production and CO 2 capture. Here, the recyclable electro-driven process of CO 2 capture and indirect H 2 O electrolysis was developed. In the process, the energy recovery system was developed to utilize the reaction heat. The non-neutral Ni based catalyst with single-atom catalysis was designed. DFT model and energy recovery model were developed. The turnover frequency, transmission value, electron density, band structure, reaction kinetics of hydrogen production and CO 2 desorption were determined. A mechanism of second dehydrogenation and second hydrogen release was identified for the non-neutral catalysis. Non-neutral NiAlTiR+ catalyst enhanced the electron transport and made electron dense region extend to the single atom zone. The 90% yield of hydrogen was produced due to the fast electron transport. The well regenerated catalyst during the 25 cycles produced the 80–90% turnover frequency and transmission compared with the fresh catalyst. The non-neutral catalyst, catalyst regeneration and reaction energy recovery reduced the energy consumption for H 2 production and CO 2 capture to 0.4 V and 1 GJ/t. [ABSTRACT FROM AUTHOR]

Abstract The management of industrial sludge generated considerable interest for environmental protection. The cost associated with the treatment of sludge with high water content is considerably higher before the discharge of a clean effluent. In order to reduce this cost, this study developed the co-combustion of coal and sludge with high water content in a 220 t/h boiler, to tackle the sludge and control the SO 2 , NO x , and CO 2 emissions from the boiler. The idea at the basis of this study was to directly eject the sludge with high water content into the boiler. A dynamic full-field synergy model was developed to perform the environmental assessment, which considers the dynamic characteristic and the full-field synergy over two co-combustion fields. Industrial field data were used to validate the model. It was found that boiler efficiency decreased only by 0.1% with sludge ejection, while flue gas moisture was almost unvaried. The SO 2 and NO x emissions were reduced by 14.27% and 8.23% respectively, if compared with emissions without co-combustion of coal and sludge. The results are attributed to the improved synergy effects. The drive forces of liquid and solid particles are the dominant steps for the fluid flow field transformation between the W-shape and the M-shape. The dynamic full-field synergy model, presented in this study, allows the characterization of co-combustion with 92% water content and a nozzle diameter of 1.5–3.5 mm. It accurately describes the full-field synergy effects of the field number over two, a result that could not be obtained by the conventional multi-field synergy model. Graphical abstract Image 1 Highlights • Co-combustion process for coal and sludge with high water content is developed. • The dynamic model of full field synergy characterizes the environmental effects. • Co-combustion with 2 mm nozzle is suitable for a water content of up to 92%. • Co-combustion reduces the concentration of SO 2 , NO x and CO 2 by 8%. [ABSTRACT FROM AUTHOR]

Chemical absorption is an effective method for CO 2 capture. Due to their high absorption/desorption efficiency, amines have been used in single or blended form. Compared with the single ones, blended solvents usually show better absorption/desorption performance because of their interactive enhancement effect, however the mechanism is still unclear. In this study, the chemical interactive reaction is assumed to be one of the key factors for the enhancement. Based on this, the reactions of CO 2 absorption in binary amine solvents (the binary mixtures of monoethanolamine (MEA)/piperazine (PZ)/2-amino-2-methyl-1-propanol (AMP)/diethanolamine (DEA)) have been investigated. The ab initio method with Density Functional Theory (DFT) is adopted in the simulations. Compared with other amines, numerical results showed that PZ presents the lowest forward energy barrier and the second lowest backward energy barrier in zwitterion formation. During the intermolecular hydrogen transfer processes, PZ shows a significant enhancement effect on MEA/DEA/AMP in the interactive reactions. For MEA, it shows an enhancing effect on AMP but hindering effect on PZ and DEA. Moreover, it was found that the MEA + COO − based reactions have good absorption property while the AMP + COO − based ones have good desorption performance. These findings reveal the interactive effect between different amines during the interactive reactions, which may provide theoretical instructions for solvent screening of blended solutions. [ABSTRACT FROM AUTHOR]

Sequence type 235 (ST235) Pseudomonas aeruginosa, harboring so-called international, high-risk, or widespread clones, is associated with relatively high morbidity and mortality, partly due to multiantibiotic and high-level antibiotic resistance. Treatment of infections caused by such strains with ceftazidime-avibactam (CZA) is often successful. However, CZA resistance in carbapenem-resistant P. aeruginosa (CRPA) strains has been consistently reported with the increasing use of this drug. Likewise, we identified thirty-seven CZA-resistant ST235 P. aeruginosa strains from among 872 CRPA isolates. A total of 10.8% of the ST235 CRPA strains were resistant to CZA. Site-directed mutagenesis, cloning, expression, and whole-genome sequencing analysis revealed that overexpression of bla GES-1 , which was carried in a class 1 integron of the complex transposon Tn 6584 , occurred due to a strong promoter, contributing to CZA resistance. Moreover, such overexpression of bla GES-1 combined with an efflux pump resulted in high-level resistance to CZA, considerably reducing the therapeutic options available for treating infections caused by ST235 CRPA. Considering the widespread presence of ST235 P. aeruginosa strains, clinicians should be aware of the risk of CZA resistance development in high-risk ST235 P. aeruginosa. Surveillance initiatives for preventing further dissemination of high-risk ST235 CRPA isolates with CZA resistance are essential. [ABSTRACT FROM AUTHOR]

Carbon dioxide mitigation strongly supports the greenhouse gas control. Amine absorption of CO 2 , as a method to mitigate the CO 2 , is a typical multi-ion system with obvious multi-ion effects. However, there is little information about the multi-ion effects on the phase flow, mass and heat transfer in amine absorption of CO 2 . The multi-ion effects have previously to be neglected to simplify the absorption process description, which produces unknown deviations from the realistic absorption process. According to experiment data, a multi-ion mass transfer, heat transfer and phase flow model is here developed to describe the realistic amine absorption of CO 2 . The turbulent diffusivity, turbulent thermal diffusivity, turbulent viscosity, CO 2 concentration, liquid temperature and velocity are analyzed under the multi-ion conditions. It was found that there is 6–22% CO 2 concentration difference between the multi-ion effects case and the neglect of the multi-ion effects (NME) case. The positive ions show the better synergy effects compared with the negative ions. Under the ion concentration of 0.001 kmol/m 3 to 0.02 kmol/m 3 , 0.2 kmol/m 3 to 2 kmol/m 3 and 4 kmol/m 3 to 7 kmol/m 3 , the multi-ion mass transfer, heat transfer and phase flow model provides an accurate description of the realistic CO 2 absorption against the NME case. Finally, Nusselt number and mass transfer coefficient models revised by synergy angles are developed to include the multi-ion effects for engineering application. Adding the amine salt and Na 2 CO 3 respectively reduce the liquid film thickness and liquid film depth, which increases the Nusselt number by 9.5% and 9.3%, respectively. Adding the metal Cu increases the Nusselt number by 11.57%, which helps to reduce the energy consumption by 7.8%. [ABSTRACT FROM AUTHOR]

Sequence type 88 community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) strain SR434, isolated from an outpatient with skin and soft tissue infection, was subjected to whole genome sequencing, antimicrobial susceptibility testing, mouse skin infection model and hemolysis analysis to identify its virulence and resistance determinants. MRSA strain SR434 is resistant to clindamycin, erythromycin and fosfomycin. Four plasmids with resistance genes were identified in this strain, including a 20,658 bp blaZ -carrying plasmid, a 2473 bp erm C-carrying plasmid, a 2622 bp fos B7-carrying plasmid (86% identity with plasmid in a ST2590 MRSA strain) and a 4817 bp lnu A-carrying plasmid (99% identity with pLNU4 from bovine coagulase-nagetive Staphylococci ). This strain contains staphylococcal cassette chromosome mec type IV and does not contain arginine catabolic mobile element or Panton-Valentine-Leukocidin. SR434 harbors genomic islands νSaα, νSaβ, νSaγ and ΦSa3 and pathogenicity islands νSa2 that carries genes encoding toxic shock syndrome toxin 1, superantigen enterotoxin C and superantigen enterotoxin L. Mouse skin infection model results show that SR434 had similar virulence potential causing invasive skin infection as a PVL-negative epidemic Korea clone HL1 (ST72). CA-MRSA strain of ST88 lineage might be a great concern for its high virulence. PVL has limited contribution to virulence phenotype among this lineage. [ABSTRACT FROM AUTHOR]

The increasing amount of CO 2 emitted to the atmosphere has a deep impact on the environment. It is urgent to take effective measures to reduce CO 2 emissions from its intensive emission source. Chemical absorption is an effective way to cover the large reduction of CO 2 , and piperazine (PZ) is one of the amines that have good performance on CO 2 capture. To make a deep understanding of the chemical mechanism of PZ absorbing CO 2 , computational studies on PZ chemically absorbing CO 2 are discussed in this work using Density functional theory (DFT). Possible reaction pathways of PZ absorbing CO 2 are analyzed. Due to the special chemical structure of PZ, the reaction processes can be divided into two parts, the process of (PZ+CO 2 )+PZ and (PZ+2CO 2 )+PZ. To make a good understanding of the reaction process, a comparison of that between PZ and MEA are discussed. The results show that PZ has lower forward and backward energy barriers than MEA in the zwitterion formation, but in the intermolecular hydrogen transfer process, PZ has higher forward and backward barriers than MEA. For the reaction process of PZ+2CO 2 , it can be stated as a two-step zwitterion formation with two transition states. For the following intermolecular hydrogen transfer of PZ(COO) 2 +PZ, the atom movements are similar to that of (PZCOO+PZ). All the discussions provide theoretical information of PZ chemical absorbing CO 2 . [ABSTRACT FROM AUTHOR]

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 absorption performance of CO 2 spray absorption process. Experiments were conducted to investigate the effects of varies operating parameters on the overall mass transfer coefficient in various operating conditions. Experimental results showed that liquid to gas ratio and mole ratio of MEA to CO 2 are key factors which affect the performance of CO 2 absorption process and the maximum overall mass transfer coefficient for the diameter-varying dual-nozzle opposed impinging spray tower is 0.4773 kmol·m -3 ·h -1 ·kPa -1 . [ABSTRACT FROM AUTHOR]

To investigate the in vivo evolution of the mucoid-phenotype of ST11-KL64 carbapenem-resistant Klebsiella pneumoniae (CRKP) isolated from the same patients and gain insights into diverse evolution and biology of these strains. Whole genome sequencing and bioinformatic analysis were used to determine the mutation involved in the mucoid phenotype of ST11-KL64 CRKP. Gene knockout, bacterial morphology and capsular polysaccharides (CPS) extraction were used to verify the role of wzc and wcaJ in the mucoid phenotypes. Antimicrobial susceptibility, growth assay, biofilm formation, host cell adhesion and virulence assay were used to investigate the pleiotropic role of CPS changes in ST11-KL64 CRKP strains. Mutation of wzc S682N led to hypermucoid phenotype, which had negative impact on bacterial fitness and resulted in reduced biofilm formation and epithelial cell adhesion; while enhanced resistance to macrophage phagocytosis and virulence. Mutations of wcaJ gene led to non-mucoid phenotype with increased biofilm formation and epithelial cell adhesion, but reduced resistance of macrophage phagocytosis and virulence. Using virulence gene knockout, we demonstrated that CPS, rather than the pLVPK-like virulence plasmid, has a greater effect on mucoid phenotypic changes. CPS could be used as a surrogate marker of virulence in ST11-KL64 CRKP strains. ST11-KL64 CRKP strains sacrifice certain advantages to develop pathogenicity by changing CPS with two opposite in vivo evolution strategies. [ABSTRACT FROM AUTHOR]

CO 2 capture affords to control the greenhouse gas emissions effectively. Monoethanolamine (MEA) absorption of CO 2 shows great potentials to mitigate the industrial CO 2 emission. Unfortunately, it is an energy-intensive process. A meso-scale model was developed to characterize coupling effects between micro-scale and phase-scale to intensify the MEA absorption process. Mass transfer coefficient (MC) and Nusselt number ( Nu ) are used to determine the mechanisms among micro-scale, phase-scale and meso-scale. It is found that meso-scale MC and Nu do not equal to the sum of micro-scale and phase-scale values due to the interaction effects between micro-scale and phase-scale. MEA conformer, O–N distance, temperature and slip velocity significantly affect the meso-scale MC and Nu due to their strong impacts on film structure and interphase area. The liquid film thickness and length decrease by 40% and 32% as slip velocity increased from 0.1 m/s to 0.3 m/s, respectively, while the interphase area increases by 6%. The energy consumption is reduced to 2.65 GJ/t under the gGt MEA conformer, saving 17% energy against the experiment baseline case. The meso-scale model is proved to be a useful method to intensify the amine solutions absorption of CO 2 . Adjusting pH value, concentrating the amine solution to 9 kmol/m 3 , extremely increasing the absorption temperature up to 353.15 K and adding nano Fe 3 O 4 are the feasible ways to achieve the meso-scale intensification effects. [ABSTRACT FROM AUTHOR]

Hydrogen is an important resource in chemical processes. In the hydrogen network, many units are operating at high temperature and pressure, which leads to a large energy change of hydrogen streams. However, the recovery of heat and work in the hydrogen flows has seldom been studied together with the optimization of hydrogen network. It is obviously that the reuse of heat and work energy will raise the effective utilization rate of energy. The recovery of heat could be realized by heat exchangers. The recovery of work will be realized by rotary work exchangers, which are composed of several compressors and turbines with the same shaft. A state space superstructure is adopted to handle all the variables. The mathematical model is built based on exergoeconomic analysis considering both energy and economic factors. The optimization problem will be a mixed integer nonlinear programming (MINLP) problem. The existing algorithms will be improved. A typical refinery hydrogen network is studied as an example. The state space superstructure, exergoeconomic analysis and proposed algorithm could solve the problem competently. The consideration of pressure and heat recovery could reduce the energy consumption and economic cost simultaneously. [ABSTRACT FROM AUTHOR]

Energy crisis becomes increasingly serious with the rapid industrial development. Apart from searching for the alternative energy sources, researchers are dedicated to increasing the efficiency of energy utilization in the industrial production process to alleviate the energy scarcity. The integration of heat, mass and pressure exchange networks is regarded as an effective way to reduce the energy consumption. This paper introduces exergoeconomic analysis to the integrated network optimization. The exergoeconomic analysis is performed by an overall analysis of energy and economic factors, which is very useful for industrial process design. The optimization turns out to be a mixed integer nonlinear programming (MINLP) problem due to the multi-objective and multi-constraint factors. A modified state space model is developed for the integrated network to handle all the parameters and possible network structures. Genetic algorithm is employed to get a globally optimal solution based on the developed state space model and MATLAB program. Case studies are carried out to demonstrate that exergoeconomic analysis is more suitable than the optimization of annual cost or raw material consumption. The results show that exergoeconomic analysis based on the proposed state space model performs well to solve the integrated network problems. [ABSTRACT FROM AUTHOR]

Summary: Objective: To investigate the resistance of Escherichia coli and Klebsiella pneumoniae producing extended-spectrum β-lactamases (ESBLs) and the genotyping of ESBLs in China. Methods: MICs of 12 antibiotics against 50 strains (by random selection) of ESBLs-producing E. coli and K. pneumoniae were determined by E-test. The genotypes of ESBLs were analyzed by PCR, DNA sequencing and isoelectric focusing. Results: The susceptibility rate of 50 isolates was 100% in imipenem, 60%–80% in cefoperazone/sulbactam, ceftazidime and piperacillin/tazobactam, and lower in other antimicrobial agents tested. Only 6.0% of the isolates were sensitive to cefotaxime. Four hundred and forty-seven of 509 isolates had been confirmed the genotype of ESBLs. Four hundred and sixteen strains produced only one type of ESBLs, including CTX-M-14 (271 strains), CTX-M-3 (70 strains), CTX-M-24 (35 strains), CTX-M-22 (8 strains), CTX-M-15 (4 strains), CTX-M-9 (4 strains), CTX-M-28 (3 strains), CTX-M-12 (1 strain), CTX-M-13 (1 strain), CTX-M-27 (1 strain), CTX-M-29 (1 strain), SHV-12 (10 strains), SHV-5 (4 strains), SHV-2 (2 strains), and SHV-9 (1 strain). Thirty isolates carried two or three types of ESBLs, and producing CTX-M-14 and CTX-M-3 together were the most common type. Conclusion: The resistance of E. coli and K. pneumonia producing ESBLs in China was a serious issue and CTX-M type ESBLs were the most common genotype. CTX-M-14 was the predominant genotype. Some isolates produced two or three ESBLs. [Copyright &y& Elsevier]

[Display omitted] • Explore the effects of B (Al, Ga) as dopants on the CO 2 adsorption by Li 4 SiO 4. • CO 2 combines with the lattice O atom of Li 4 SiO 4 with −1.91 eV adsorption energy. • Doping of B, Al and Ga to Li atom in Li 4 SiO 4 is favorable for CO 2 desorption. • B, Al and Ga acting as a promoter is beneficial to the desorption of CO 2. The removal of CO 2 by lithium silicate is of great significance to alleviate global warming. In order to understand the micro mechanism of the interaction between CO 2 and lithium silicate, density functional theory model is developed to explore the effects of B, Al and Ga as dopants and promoters on the CO 2 adsorption performance of lithium silicate. Adsorption energy, charge transfer and desorption barrier of CO 2 are calculated. It is found that CO 2 combines with the lattice oxygen atom on the surface with C atom, and the adsorption energy is −1.91 eV. The doping of B, Al and Ga to Si atom in lithium silicate intensifies the adsorption of CO 2 and inhibits the desorption of CO 2. Doping of B, Al and Ga to Li atom has the opposite effect. These results provide the interaction mechanism between CO 2 and lithium silicate and show the strategy to modify lithium silicate for CO 2 capture. [ABSTRACT FROM AUTHOR]

Rectisol wash process(RWP) is a common process in coal chemical purification unit. However, the CO 2 product gas and tail gas in the RWP carries volatile organic methanol, which must be controlled to meet the environmental protection requirements. This work develops a steady and dynamic model for the process of water washing tower(WWT) by Aspen Plus, which is used in Rectisol wash tail gas treatment. The effects of the theoretical stage number(TSN) and desalting water flow rate(FR dw) of the washing tower on the methanol concentration in tail gas(c MET) are studied through sensitivity analysis. The optimized TSN and FR dw of WWT are 16 stages and 15 t/h, respectively. The c MET is 4.1 mg/Nm3 under the optimal condition. The internal structure of WWT is optimized. The design of the WWT is verified by the hydraulic results and dynamic process simulation. The results help to efficiently and conveniently implement the control of volatile organic methanol from RWP. [ABSTRACT FROM AUTHOR]

Carbon dioxide capture significantly helps achieve the carbon neutral goal. Chemical absorption of CO 2 by the solvent meets the bottleneck of the high energy consumption. An advanced solvent of CuH/PANI/TEMPO has been developed to reduce the energy consumption. The metal hydride CuH decomposes into the Cu atom to intensify the thermoelectric effect between PANI and TEMPO. The strong thermoelectric effect has the potential to enhance the CO 2 desorption. DFT model and mass and energy transfer model in the nano-scale are developed accurately to quantify the system of CO 2 and CuH/PANI/TEMPO. The CO 2 fraction, electron density and velocity in the nano-domain are studied. It is found that the symmetrical electron density zone is produced. The mass transfer coefficient is improved by 2.15 times with 4.65 × 10−6 m/s and the energy consumption is reduced to 1.02GJ/tCO 2. The thermoelectric conversion accounts for 31.4%–43.5% of the overall energy transfer. [Display omitted] • CO 2 capture by thermoelectric effect in a solvent with metal hydride. • Mass and energy transfer model incorporating Angstrom scale information. • Mass transfer coefficient improved by twice. • Energy consumption reduced to 1.02GJ/t. [ABSTRACT FROM AUTHOR]

Sludge water with high COD and CO 2 emission in industry pollutes the environment. In order to effectively mitigate the COD and CO 2 , this study developed an integrated process of COD removal and CO 2 capture by utilizing CO 2 to intensify the COD removal process. The mass transfer model and gas and liquid two phase flow model were developed and validated by the experiment. The dynamical characteristic, COD removal and CO 2 capture performance were accurately investigated. The effect of the flue gas, Ca(OH) 2 solution and sludge water on the COD removal and CO 2 capture were discussed in detail. Due to the bond effect of Ca-O-C and large contact area, the highest CO 2 capture efficiency reached 93.1% at simultaneous COD removal. The CO 2 intensification effect on the COD removal was analyzed by the density functional theory. It was found that CO 2 made the Ca(OH) 2 remove COD more stably due to CO 2 controlling the free ions. The CO 2 and Ca(OH) 2 regenerated efficiency respectively reached 85.3% and 88.9% by the electrochemical method. Image 1 • To develop an integrated process of COD removal and CO 2 capture. • Mass transfer model and gas and liquid two phase flow model developed. • CO 2 intensification effect on COD removal explained by the density functional theory. • CO 2 and Ca(OH) 2 regenerated efficiency respectively obtained at 85.3% and 88.9%. [ABSTRACT FROM AUTHOR]