Dimethyl Carbonate Synthesis from CO2 over CeO2 with Electron-Enriched Lattice Oxygen Species.

Direct synthesis of dimethyl carbonate (DMC) from CO2 plays an important role in carbon neutrality, but its efficiency is still far from the practical application, due to the limited understanding of the reaction mechanism and rational design of efficient catalyst. Herein, abundant electron-enriched lattice oxygen species were introduced into CeO2 catalyst by constructing the point defects and crystal-terminated phases in the crystal reconstruction process. Benefitting from the acid-base properties modulated by the electron-enriched lattice oxygen, the optimized CeO2 catalyst exhibited a much higher DMC yield of 22.2 mmol g-1 than the reported metal-oxide-based catalysts at the similar conditions. Mechanistic investigations illustrated that the electron-enriched lattice oxygen can provide abundant sites for CO2 adsorption and activation, and was advantageous of the formation of the weakly adsorbed active methoxy species. These were facilitating to the coupling of methoxy and CO2 for the key *CH3OCOO intermediate formation. More importantly, the weakened adsorption of *CH3OCOO on the electron-enriched lattice oxygen can switch the rate-determining-step (RDS) of DMC synthesis from *CH3OCOO formation to *CH3OCOO dissociation, and lower the corresponding activation barriers, thus giving rise to a high performance. This work provides insights into the underlying reaction mechanism for DMC synthesis from CO2 and methanol and the design of highly efficient catalysts.

Distribution of antibiotic resistance genes and their pathogen hosts in duck farm environments in south-east coastal China.

Livestock farms are major reservoirs of antibiotic resistance genes (ARGs) that are discharged into the environment. However, the abundance, diversity, and transmission of ARGs in duck farms and its impact on surrounding environments remain to be further explored. Therefore, the characteristics of ARGs and their bacterial hosts from duck farms and surrounding environment were investigated by using metagenomic sequencing. Eighteen ARG types which consist of 823 subtypes were identified and the majority conferred resistance to multidrug, tetracyclines, aminoglycosides, chloramphenicols, MLS, and sulfonamides. The floR gene was the most abundant subtype, followed by sul1, tetM, sul2, and tetL. ARG abundance in fecal sample was significantly higher than soil and water sample. Our results also lead to a hypothesis that Shandong province have been the most contaminated by ARGs from duck farm compared with other four provinces. PcoA results showed that the composition of ARG subtypes in water and soil samples was similar, but there were significant differences between water and feces samples. However, the composition of ARG subtypes were similar between samples from five provinces. Bacterial hosts of ARG subtypes were taxonomically assigned to eight phyla that were dominated by the Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria. In addition, some human bacterial pathogens could be enriched in duck feces, including Enterococcus faecium, Acinetobacter baumannii, and Staphylococcus aureus, and even serve as the carrier of ARGs. The combined results indicate that a comprehensive overview of the diversity and abundance of ARGs, and strong association between ARGs and bacterial community shift proposed, and benefit effective measures to improve safety of antibiotics use in livestock and poultry farming. KEY POINTS: • ARG distribution was widespread in the duck farms and surroundings environment • ARG abundance on the duck farms was significantly higher than in soil and water • Human bacterial pathogens may serve as the vectors for ARGs.

An adsorption isotherm identification method based on CNN-LSTM neural network.

CONTEXT: The morphology of adsorption isotherms embodies a wealth of information regarding various adsorption mechanisms, rendering the classification and identification methodologies predicated on the shape of adsorption isotherms indispensably crucial. While research on classification techniques has been extensively developed, traditional methods of adsorption isotherm identification grapple with inefficiencies and a high margin of error. Neural network-based methodologies for adsorption isotherm identification serve as a countermeasure to these shortcomings, as they facilitate swift online identification while delivering precise results. In this paper, we deploy a hybrid of convolutional neural networks (CNN) and long short-term memory (LSTM) networks for the identification of adsorption isotherms. Extensive theoretical adsorption isotherms are generated via adsorption equations, forming a comprehensive training database, thereby circumventing the need for time-consuming and costly repetitive experiments. The F1-score, receiver operating characteristic (ROC) curves, and area under the ROC curve (AUC) are introduced as criteria to evaluate the identification performance and generalization ability of the model during the testing phase. The results highlight the model's superlative performance in the task of adsorption isotherm identification, with accuracy rates of 100% in both the training and validation sets. The mean F1-score obtained from the testing set reached 0.8885, with both macro-average and micro-average AUC exceeding 0.95. METHOD: PyCharm was employed as an experimental and testing platform, with Python 3.9 serving as the programming language. TensorFlow 2.11.0 and Keras 2.10.0 were harnessed for the training and testing of CNN-LSTM, while numpy 1.21.5 and scipy 1.81 were utilized for the creation of training and validation datasets.

Comprehensive profiling of serotypes, antimicrobial resistance and virulence of Salmonella isolates from food animals in China, 2015-2021.

Introduction: Salmonella is a ubiquitous foodborne pathogen and mainly transmitted to human farm-to-fork chain through contaminated foods of animal origin. Methods: In this study, we investigated the serotypes, antimicrobial resistance and virulence of Salmonella from China. Results: A total of 617 Salmonella isolates were collected from 4 major food animal species across 23 provi nces in China from 2015-2021. Highest Salmonella prevalence were observed in Guangdong (44.4%) and Sandong (23.7%). Chickens (43.0%) was shown to be the major source of Salmonella contamination, followed by pigs (34.5%) and ducks (18.5%). The number of Salmonella increased significantly from 5.51% to 27.23% during 2015-2020. S. Derby (17.3%), S. Enteritidis (13.1%) and S. Typhimurium (11.4%) were the most common serotypes among 41 serotypes identifiedin this study. Antibiotic susceptibility testing showing that the majority of the Salmonella isolates were resistant to neomycin (99.7%), tetracycline (98.1%), ampicillin (97.4%), sulfadiazine/trimethoprim (97.1%), nalidixic acid (89.1%), doxycycline (83.1%), ceftria xone (70.3%), spectinomycin (67.7%), florfenicol (60.0%), cefotaxime (52.0%) and lomefloxacin (59.8%). The rates of resistance to multiple antibiotics in S. Derby and S.Typhimurium were higher than that in S. Enteritidis. However, the rate of resistance to fosfomycin were observed from higher to lower by S. Derby, S. Enteritidis, and S. Typhimurium. Biofilm formation ability analysis found that 88.49%of the Salmonella were able to produce biofilms, of which 236 Salmonella isolates were strong biofilm producer. Among the 26 types of antibiotics resistance genes (ARGs) were identified in this study, 4 ARGs (tetB,sul2,aadA2, and aph(3')-IIa) were highly prevalent. In addition, 5 ß-lactam resistance genes (bla TEM, bla SHV, bla CMY-2, bla CTX-M, and bla OXA) and 7 quinolone resistance genes (oqxA, oqxB, qnrB, qnrC, qnrD, qnrS, and qeqA) were detected among these isolates. 12 out of 17 virulence genes selected in this study were commonly presented in the chromosomes of tested isolate, with a detection rate of over 80%, including misL, spiA, stn, pagC, iroN, fim, msgA, sopB, prgH, sitC, ttrC, spaN. Discussion: This study provided a systematical updating on surveillance on prevalence of Salmonella from food animals in China, shedding the light on continued vigilance for Salmonella in food animals.

Prevalence and molecular characteristics of mcr-1-positive Escherichia coli isolated from duck farms and the surrounding environments in coastal China.

The emergence of colistin-resistance is considered a threat to public health and colistin-resistant bacteria have recently been reported in animal, environmental and human sources. Whereas, the epidemic and dissemination of colistin-resistant bacteria in duck farms have not been surveyed, especially the surrounding environmental contamination from duck farms. We investigated the prevalence and molecular characteristics of mcr-1-positive E. coli from duck farms in coastal China. 360 mcr-1-positive E. coli isolates were collected from 1112 samples from duck farms and surrounding environments. The prevalence of mcr-1-positive E. coli in Guangdong province was higher than other two provinces we examined. PFGE analysis indicated clonal spread of mcr-1-positive E. coli between duck farms and surrounding environments, including water and soil. MLST analysis demonstrated that ST10 was more common than ST1011, ST117, and ST48. Phylogenomic analysis also suggested mcr-1-positive E. coli collected from distinct cities were assigned to the same lineage and mcr-1 was primarily located on IncI2 and IncHI2 plasmids. Genomic environment analysis showed mobile gene elements ISApl1 most likely plays a key role in the horizontal transmission of mcr-1. WGS further revealed that mcr-1 was found associated with 27 different ARGs. Our findings emphasize the urgent need for effective colistin resistance surveillance in humans, animals and the environment.

Thermal transport in porous graphene with coupling effect of nanopore shape and defect concentration.

Thermal conductivity of porous graphene can be affected by defect concentration, nanopore shape and distribution, and it is hard to clarify the effects due to the correlation of those factors. In this work, molecular dynamics simulation is used to compare the thermal conductivity of graphene with three shapes of regularly arranged nanopores. The results prove the dominant role of defect concentration under certain circumstances in reducing thermal conductivity, while the coupling effect of nanopore shape should be noticed. When the atoms at the local phonon scattering area around each nanopore are properly removed, the abnormal increment of thermal conductivity can be detected with the increase of defect concentration. Heat flux vector angles can effectively characterize the local phonon scattering area, which can be used to describe the effect of nanopore shape. The coupling effect of defect concentration and pore shape with similar heat flux path is clarified according to this process. By adjusting vertex angle of triangle defect, there is a balanced state of the effect factors between the variation of defect concentration and the same phonon scattering area. It provides a possible way to describe the weighing factors of the coupling effect. The results suggest a feasible approach to optimize and regulate thermal properties of porous graphene in nanodevice.

How has the efficiency of China's green development evolved? An improved non-radial directional distance function measurement.

As a key choice for human sustainable development, green development is also one of China's five major vision points. To explore the level of green development in China since it was first written into national documents in 2011, this paper applies an improved non-radial distance function based on Data Envelopment Analysis method to analyze the progress against the development targets set in related national documents. The results show that: (1) China's green development efficiency has kept increasing in 2011-2017. (2) The growth in green development efficiency was significantly higher in the 13th Five-Year Plan period compared to the 12th Five-Year Plan period. (3) The green development efficiency shows a decreasing trend from south to north, east of the Hu line. This study provides a more practical idea for evaluating the quality of green development in mainland China.

Transmission and molecular characteristics of blaNDM-producing Escherichia coli between companion animals and their healthcare providers in Guangzhou, China.

OBJECTIVES: To determine the transmission and molecular characteristics of blaNDM-producing Escherichia coli between companion animals and their healthcare providers at veterinary clinics in Guangzhou, China. METHODS: A total of 359 samples from companion animals and their healthcare providers were collected at 14 veterinary clinics in Guangzhou, China. Genomic characteristics and clonal relationships for blaNDM-positive E. coli and complete plasmid sequences were characterized based on WGS data from combined Illumina and MinION platform reads. RESULTS: Forty-five blaNDM-positive bacteria were recovered from companion animals (n = 43) and their healthcare providers (n = 2) at 10 veterinary clinics. Overall, E. coli (73.3%, 33/45) and Klebsiella pneumoniae (13.3%, 6/45) were the most prevalent species among the seven species of blaNDM-positive bacteria. Four blaNDM variants (blaNDM-1, blaNDM-4, blaNDM-5 and blaNDM-7) were identified in 45 blaNDM-positive bacteria and blaNDM-5 was the most prevalent (77.8%, 35/45). WGS indicated that the most prevalent STs were ST405 (8/33), ST453 (6/33), ST457 (6/33) and ST410 (5/33) among the 33 blaNDM-positive E. coli isolates. Phylogenomics and PFGE analysis revealed that clonal spread of blaNDM-positive ST453 E. coli isolates between companion animals and their healthcare providers was evident. In addition, two novel IncFIB plasmids carrying blaNDM-4 (pF765_FIB and pG908_FIB) were found in this study and indicated that IS26 may promote the horizontal transmission of blaNDM between different plasmid types. CONCLUSIONS: In this study we conducted a large-scale investigation on the prevalence of blaNDM-positive E. coli isolates from companion animals and their healthcare providers and revealed the clonal spread of blaNDM-positive E. coli isolates between these two groups.

Investigating industrial water-use efficiency in mainland China: An improved SBM-DEA model.

Improving water-use efficiency (WUE) is a crucial way of achieving green industrial production and sustainable development. Applying an improved Super-slacks-based measure model with undesirable outputs, this paper investigates industrial WUE in mainland China. The results show that: (1) Industrial WUE in China is improving with the efficiency value increasing from 0.9874 to 0.9962 in 2012-2015. (2) The regions of water absolute scarcity and the vulnerability show the highest industry-related WUE, whereas the water stressed region, water scarce region, and water abundant region failed to achieve efficiency during the observation period. (3) The overall index value using the conventional model was higher than that of the improved model, indicating the need for a more reasonable water-use structure and environmentally friendly discharge structure. This study provides a new perspective for measuring industrial WUE and advances related studies by (1) incorporating the actual structure of water used and wastewater discharged with weights assigned to input and output slacks according to marginal use cost of water and marginal treatment cost of wastewater; and (2) adding realistic constraints on the amount of water used and wastewater discharged to the model. The estimated provinces in mainland China can adjust their industrial water-use structures and wastewater-discharge structures based on the results of this study, and thus improve the industrial WUE.

High prevalence of bronchiectasis in emphysema-predominant COPD patients.

Background: COPD has been identified as an etiology or related disease of bronchiectasis, and bronchiectasis has been classified as a comorbidity of COPD. In this study, we investigated the prevalence of bronchiectasis in different phenotypes of COPD subjects and the correlation between bronchiectasis and different phenotypes, especially emphysema. Methods: COPD patients were recruited from April 2012 to December 2015. The presence of bronchiectasis and related information were statistically analyzed. COPD subjects were separated into subgroups in two ways: COPD with and without bronchiectasis groups and emphysema-predominant (emphysema index, EI≥9.9%) and non-emphysema-predominant (EI<9.9%) groups. Results: In total, 1,739 COPD patients were incorporated into the study, among which 140 cases (8.1%) were accompanied with radiological bronchiectasis. COPD patients with concomitant bronchiectasis presented worse pulmonary function (FEV1% predicted, P<0.001), higher EI (15.0% vs 13.4%, P<0.001), and higher proportion of pulmonary hypertension and cor pulmonale (6.4% vs 2.4%, P=0.005 and 23.6% vs 16.1%, P=0.022) than patients without bronchiectasis. Of all the COPD patients, 787 with EI data were divided into emphysema-predominant (n=369) and non-emphysema-predominant groups (n=418). The proportion of bronchiectasis was 16.5% and 10.3% (P=0.01), respectively. Severity of bronchiectasis increased as the degree of airflow limitation (r=-0.371, P<0.001) and emphysema increased (r=0.226, P=0.021). After adjusting confounding factors, FEV1% predicted (OR, 1.636; 95% CI, 1.219-2.197; P=0.001) and EI (OR, 1.993; 95% CI, 1.199-3.313; P=0.008) were significantly related with the presence of bronchiectasis in COPD patients. Conclusion: The proportion of bronchiectasis is higher in emphysema-predominant COPD subjects. Emphysema measured by EI and FEV1% predicted are independent predictors for bronchiectasis in COPD subjects, while the underlying mechanism deserves further investigation.

Completeness of ultrasound reporting impacts time to biopsy for benign and malignant thyroid nodules.

BACKGROUND: The objective was to evaluate reporting of guideline-recommended elements for thyroid ultrasound (US), and to determine whether element reporting was associated with the time to cytological and/or surgical diagnosis. METHODS: US reports of adults who underwent thyroid surgery for benign (n = 106) or malignant (n = 105) thyroid nodules between 2009 and 2014 were retrospectively reviewed for inclusion of 11 elements. RESULTS: On average 5.1 elements of 11 (46.4%) were included in US reports of all nodules. The setting of the US (academic versus community center) also influenced the number of elements reported (6.3 in academic versus 4.9 in community, p < 0.001). A higher number of reported elements were significantly associated with fewer days between US and FNAB, FNAB and OR, and US and OR (p < 0.001, p = 0.007, and p < 0.001, respectively). CONCLUSIONS: Under-reporting of guideline-recommended US elements is associated with delayed cytological diagnosis and surgical treatment of thyroid nodules.

Management of PET diagnosed thyroid incidentalomas in British Columbia Canada: Critical importance of the PET report.

BACKGROUND: PET diagnosed thyroid incidentalomas (TI) should undergo prompt evaluation due to a high risk of underlying malignancy. Our study reviewed physician management of PET diagnosed TIs in British Columbia (BC), Canada. METHODS: All PET reports from BC between 2011 and 2014 were reviewed. Clinical and demographic data was obtained for TI patients through chart review and mail out surveys to physicians. Statistical analysis was performed to identify factors associated with further TI investigation. RESULTS: 4.7% PET scans diagnosed TIs in 5.3% of patients. 9.8% of diffuse and 46.1% of focal TI cases underwent ultrasound ± biopsy. PET scan report characteristics were significantly associated with further TI investigation (p-value <0.05). CONCLUSIONS: Patients with PET diagnosed TIs are being under-investigated in BC and PET scan report related factors were found to be significantly associated with undergoing further TI workup.