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Winds are commonly observed in luminous active galactic nuclei. A plausible model of those winds is magnetohydrodynamic (MHD) disc winds. In the case of disc winds from a thin accretion disc, isothermal or adiabatic assumption is usually adopted in such MHD models. In this work, we perform two-dimensional MHD simulations implementing different thermal treatments (isothermal, adiabatic, and radiative) to study their effects on winds from a thin accretion disc. We find that both the isothermal model and the adiabatic model overestimate the temperature, underestimate the power of disc winds, and cannot predict the local structure of the winds, compared to the results obtained by solving the energy equation with radiative cooling and heating. Based on the model with radiative cooling and heating, the ionization parameter, the column density, and the velocity of the disc winds have been compared to the observed ultra-fast outflows (UFOs). We find that in our simulations the UFOs can only be produced inside hundreds of Schwarzschild radius. At much larger radii, no UFOs are found. Thus, the pure MHD winds cannot interpret all the observed UFOs. [ABSTRACT FROM AUTHOR]

In order to analyze the performance indicators of the train network and explore the factors affecting the performance indicators of the train network, the model of Ethernet is improved according to the three-layer modelling mechanism of OPNET. The topology model, node model, process model, data packet format model and link model of the multi-marshalling Ethernet backbone network are built, and the links of the network are made under different load conditions. The simulation results show that the high-speed EMU train network based on ARCNET protocol can meet the requirements of the train communication network in terms of real-time and reliability, but the network has the disadvantage of low data transmission rate. Therefore, the backbone network of Ethernet train has great engineering application value in the train network. [ABSTRACT FROM AUTHOR]

In order to explore the application of particle swarm optimization (PSO) in the control of electric multiple unit (EMU) brake control system, the principle of EMU braking system, block partition and Quantum swarm optimization (QSO) is understood. PSO is applied to the diagnosis model of EMU braking process, and then the data are analyzed through computer simulation experiments. The results show that PSO algorithm has obvious effect on the diagnosis model of EMU braking process under railway block partition. When using PSO, the number of iterations of EMU braking system model to achieve convergence equilibrium is much less than that of ordinary model, which has obvious rapidity and ease of implementation and has great significance especially in safety. In summary, PSO is very suitable for being applied the diagnosis model of EMU brake control system. [ABSTRACT FROM AUTHOR]

Successful popularization of wearable energy storage devices lies in the exploitation of scalable fabrication technologies that are based on economically viable materials. Herein, we reveal that discarded cotton pads can be used as a cost-efficient substrate for the in situ polymerization of pyrrole and exhibited good mechanical flexibility, lightness, and high conductivity. To extend the applications of the resulting PPy-coated cotton pads (PCPs) to the supercapacitor field, a layer of MnO2 nanosheets was further decorated on the surface of PCPs (PCPs@MnO2) by a simple electrochemical deposition technique. The PPy coating not only improves the electrical conductivity of the cotton pads, but also increases the contact between the active materials and the cotton fibers. Amazingly, ultrathin (≈ 0.8 mm) flexible solid-state asymmetric supercapacitors (ASCs) using PCPs@MnO2 as the positive electrode and active carbon coated on PCPs (PCPs@AC) as the negative electrode display a high areal capacitance of 1.21 F cm−2 at 1 mA cm−2, and a high energy density of 6.8 mW h cm−3 at a power density of 11.2 mW cm−3, which can also be tailored and folded into various shapes with only slight capacitance fading. These findings demonstrate that the prepared advanced ultralight, flexible and renewable cotton pads hold great promise for practical application in wearable energy storage systems with high cost effectiveness and scalability. [ABSTRACT FROM AUTHOR]

A novel type of NiCo2S4/carbon nanotube (NCS/CNT) nanocomposite has been successfully prepared via a simple refluxing route without any surfactant and template. SEM and TEM observations confirm that the as-obtained NiCo2S4/CNT nanocomposites exhibit a necklace-like architecture, in which the NiCo2S4 particles are threaded with CNTs. As electrode materials for supercapacitors, the nanocomposites deliver an obviously pseudocapacitive behavior enhanced by a synergistic effect. When the loaded amount of CNTs is 10 mg (NCS/CNT-10), the maximum specific capacitance reaches up to 2210 F g−1 at 1 A g−1 and the specific capacitance can be maintained at 1949 F g−1 at 1 A g−1 after 14 000 multi-rate charge–discharge cycles. By applying the NCS/CNT-10 composite as the positive electrode and activated carbon as the negative electrode, an asymmetric supercapacitor was fabricated with excellent electrochemical performance. Such a large enhancement of the electrochemical performance is attributed to the strong necklace-like architectures, which possess advantages such as high electric conductivity, good mechanical stability and excellent strain accommodation. [ABSTRACT FROM AUTHOR]

A method was developed for determining selenium with a self-made ion-selective electrode was developed. This electrode was made by using Ag2Se as electroactive material. Optimal working conditions and interferences were investigated. The electrode exhibits good potentiometric response for Se2− ions over the concentration range from 6 × 10−7 mol · L−1 to 1 × 10−4 mol · L−1 with a Nernstian slope of 28 ± 1 mV per decade and a detection limit of about 4.5 × 10−7 mol · L−1. It was used over six months and exhibits good selectivity and sensitivity towards Se2−. The method was applied to determine selenium in biological materials. The recovery ranges between 92% and 105.5%, and the relative standard derivation is less than 3.6% (n = 6). [ABSTRACT FROM AUTHOR]

Niobium oxides are potential anode materials for ultrafast and safe lithium‐ion batteries due to their high ionic conductivity and relatively high operation voltage. However, the electrochemically induced phase transformations that involve multi‐electron redox reactions in a wide voltage window cause rapid capacity degradation and poor rate capability. Here, a novel carbon‐covalent amorphous niobium oxide anode is reported to greatly suppress the phase transition during cycling via formation of strong Nb─O─C bonds, achieving high‐capacity, fast‐charge and long‐duration lithium storage. This amorphous structure and forming covalent carbon contribute to good volume accommodation and high electron conductivity. The carbon‐covalent amorphous Nb2O5 displays a high reversible capacity of 361.5 mAh g−1 at 0.1 A g−1 and excellent cycling stability with a capacity of 189.8 mAh g−1 at a high rate of 10 A g−1 after 9000 cycles. Structure characterizations reveal that the well‐preserved amorphous structure without phase transition during repeated Li+ insertion/desertion is responsible for the superior performance. This work opens a new avenue on rational design of high‐performance amorphous electrode materials for next‐generation batteries. [ABSTRACT FROM AUTHOR]

Porous carbons have been extensively studied in electrochemical capacitors (ECs). However, low capacitance remains a limitation due to the electrical double layer (EDL) storage mechanism when porous carbons are used in ionic liquids (ILs) based ECs. Herein, the nitrogen‐derived vacancy defects in porous carbon nanospheres are found which can boost capacitive charge storage and present reversible high capacitance of 427 F g−1 in pure IL electrolyte, equal to a normalized area capacitance (CA) of 16 µF cm−2, surpassing the theoretical EDL CA (≈11 µF cm−2). When used as capacitive cathode, the assembled Lithium hybrid capacitor express high energy density of 635 Wh kg−1 based on active material under much high‐power density of 14.5 kW kg−1. A combination of control experiments and density functional theory investigation indicate that the EC's performance improvement mostly stems from strong interactions at vacancy defects, triggering extraordinary faradaic capacitance. The results shed light on defect engineering for realizing extra faradaic capacitance of carbon materials, and open up new opportunities for improving EC's energy density. [ABSTRACT FROM AUTHOR]

Background: Interleukin 9 (IL-9), produced mainly by T helper 9 (Th9) cells, has been recognized as an important regulator in multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Astrocytes respond to IL-9 and reactive astrocytes always associate with blood-brain barrier damage, immune cell infiltration, and spinal injury in MS and EAE. Several long non-coding RNAs (lncRNAs) with aberrant expression have been identified in the pathogenesis of MS. Here, we examined the effects of lncRNA Gm13568 (a co-upregulated lncRNA both in EAE mice and in mouse primary astrocytes activated by IL-9) on the activation of astrocytes and the process of EAE.Methods: In vitro, shRNA-recombinant lentivirus with glial fibrillary acidic protein (GFAP) promoter were performed to determine the relative gene expression and proinflammatory cytokines production in IL-9 treated-astrocytes using Western blot, real-time PCR, and Cytometric Bead Array, respectively. RIP and ChIP assays were analyzed for the mechanism of lncRNA Gm13568 regulating gene expression. Immunofluorescence assays was performed to measure the protein expression in astrocytes. In vivo, H&E staining and LFB staining were applied to detect the inflammatory cells infiltrations and the medullary sheath damage in spinal cords of EAE mice infected by the recombinant lentivirus. Results were analyzed by one-way ANOVA or Student's t test, as appropriate.Results: Knockdown of the endogenous lncRNA Gm13568 remarkably inhibits the Notch1 expression, astrocytosis, and the phosphorylation of signal transducer and activator of transcription 3 (p-STAT3) as well as the production of inflammatory cytokines and chemokines (IL-6, TNF-α, IP-10) in IL-9-activated astrocytes, in which Gm13568 associates with the transcriptional co-activators CBP/P300 which are enriched in the promoter of Notch1 genes. More importantly, inhibiting Gm13568 with lentiviral vector in astrocytes ameliorates significantly inflammation and demyelination in EAE mice, therefore delaying the EAE process.Conclusions: These findings uncover that Gm13568 regulates the production of inflammatory cytokines in active astrocytes and affects the pathogenesis of EAE through the Notch1/STAT3 pathway. LncRNA Gm13568 may be a promising target for treating MS and demyelinating diseases. [ABSTRACT FROM AUTHOR]

Energy-saving and efficient monolithic catalysts are hotspots of catalytic purification of industrial gaseous pollutants. Here, we have developed an electrothermal catalytic mode, in which the ignition temperature required for the reaction is provided by Joule heat generated when the current flows through the catalyst. In this paper, Mn/NiAl/NF, Mn/NiFe/NF and Mn/NF metal-based monolithic catalysts were prepared using nickel foam (NF) as the carrier for thermal and electrothermal catalysis of n -heptane. The results indicated that Mn-based monolithic catalysts exhibit high activity in thermal and electrothermal catalysis. Mn/NiFe/NF achieve conversion of n -heptane more than 99% in electrothermal catalysis under a direct-current (DC) power of 6 W, and energy-saving is 54% compared with thermal catalysis. In addition, the results indicated that the introduction of NiAl (or NiFe) greatly enhanced the catalytic activity of Mn/NF, which attributed to the higher specific surface area, Mn3+/Mn4+, Ni3+/Ni2+, adsorbed oxygen species (O ads)/lattice oxygen species (O latt), redox performance of the catalyst. Electrothermal catalytic activity was significantly higher than thermal catalytic activity before complete conversion, which may be related to electronic effects. Besides, Mn/NiFe/NF has good cyclic and long-term stability in electrothermal catalysis. This paper provided a theoretical basis for applying electrothermal catalysis in the field of VOCs elimination. [Display omitted] [ABSTRACT FROM AUTHOR]

Background/Aims: Multiple sclerosis (MS) is an autoimmune disease in the central nervous system associated with demyelination and axonal injury. Astrocyte activation is involved in the pathogenesis of MS and experimental autoimmune encephalomyelitis (EAE), an animal model of MS. This study was designed to find potential lncRNAs in EAE mice and activated astrocytes. Methods: we performed microarray analysis of lncRNAs from the brain tissues of EAE mice and primary mouse astrocytes treated with IL-9(50 ng/ml). 12 lncRNAs were validated through real-time PCR. Gene ontology and KEGG pathway analysis were applied to explore the potential functions of lncRNAs. Results: Differentially expressed 3300 lncRNAs and 3250 mRNAs were in the brain tissues of EAE mice, and 3748 lncRNAs and 3332 mRNAs were in activated astrocytes. Notably, there were 2 co-up-regulated lncRNAs and 3 co-down-regulated lncRNAs both in the brain tissues of EAE mice and in activated astrocytes, including Gm14005, Gm12478, mouselincRNA1117, AK080435, and mouselincRNA0681, which regulate the ER calcium flux kinetics, zinc finger protein and cell apoptosis. Similarly, there were 7 mRNAs co-up-regulated and 2 mRNAs co-down-regulated both in vivo and in vitro. Gene ontology and KEGG pathway analysis showed that the biological functions of differentially expressed mRNAs were associated with metabolism, development and inflammation. The results of realtime PCR validation were consistent with the data from the microarrays. Conclusions: Our data uncovered the expression profiles of lncRNAs and mRNAs in vivo and in vitro, which may help delineate the mechanisms of astrocyte activation during MS/EAE process. [ABSTRACT FROM AUTHOR]

• Cpd.5 was discovered as a LasR inhibitor via Structure-based virtual Screening. • 1b was identified as a more potential LasR inhibitor via structural optimization. • 1b was verified as a promising QS inhibitor via in vitro and in vivo evaluation. In this study, we report a series of 3-nitrophenol ester derivatives as promising quorum-sensing (QS) inhibitors via Structure-based Virtual Screening and structural optimization. Spectroscopic and analytical data were used to validate all synthesized targets. All the compounds were assessed for in vitro LasR inhibition activity. 3-Nitrophenol ester 1b was identified as the most promising candidate, which showed potent LasR inhibition activity (IC 50 , 5.94 μg/ml), low cytotoxicity (CC 50 > 1000 μg/ml) and no significantly bactericidal activity. Molecular docking study suggested that 1b with higher crash score value formed three intermolecular hydrogen bonds with the residues. In addition, 1b was proved to show significantly virulence inhibition against P. aeruginosa in vitro and in vivo. The whole transcriptome analysis of 1b also suggested that QS-related genes were inhibited. Taken together, compound 1b is a novel and promising QS inhibitor, which is worth for in-depth study. [Display omitted] [ABSTRACT FROM AUTHOR]

Numbers of gene expression profiling studies of bipolar disorder have been published. Besides different array chips and tissues, variety of the data processes in different cohorts aggravated the inconsistency of results of these genome-wide gene expression profiling studies. By searching the gene expression databases, we obtained six data sets for prefrontal cortex (PFC) of bipolar disorder with raw data and combinable platforms. We used standardized pre-processing and quality control procedures to analyze each data set separately and then combined them into a large gene expression matrix with 101 bipolar disorder subjects and 106 controls. A standard linear mixed-effects model was used to calculate the differentially expressed genes (DEGs). Multiple levels of sensitivity analyses and cross validation with genetic data were conducted. Functional and network analyses were carried out on basis of the DEGs. In the result, we identified 198 unique differentially expressed genes in the PFC of bipolar disorder and control. Among them, 115 DEGs were robust to at least three leave-one-out tests or different pre-processing methods; 51 DEGs were validated with genetic association signals. Pathway enrichment analysis showed these DEGs were related with regulation of neurological system, cell death and apoptosis, and several basic binding processes. Protein-protein interaction network further identified one key hub gene. We have contributed the most comprehensive integrated analysis of bipolar disorder expression profiling studies in PFC to date. The DEGs, especially those with multiple validations, may denote a common signature of bipolar disorder and contribute to the pathogenesis of disease. [ABSTRACT FROM AUTHOR]

Meta-learning has gained wide popularity as a training framework that is more data-efficient than traditional machine learning methods. However, its generalization ability in complex task distributions, such as multimodal tasks, has not been thoroughly studied. Recently, some studies on multimodality-based meta-learning have emerged. This survey provides a comprehensive overview of the multimodality-based meta-learning landscape in terms of the methodologies and applications. We first formalize the definition of meta-learning in multimodality, along with the research challenges in this growing field, such as how to enrich the input in few-shot learning (FSL) or zero-shot learning (ZSL) in multimodal scenarios and how to generalize the models to new tasks. We then propose a new taxonomy to discuss typical meta-learning algorithms in multimodal tasks systematically. We investigate the contributions of related papers and summarize them by our taxonomy. Finally, we propose potential research directions for this promising field. [ABSTRACT FROM AUTHOR]

The IPTG-induced expression of I mcr i -9.1 in I Escherichia coli i BL21(DE3) containing pET28a I mcr i -9.1 did not confer resistance to colistin, and the resistance to colistin could not be induced by using sub-MIC concentration of colistin. Most of I mcr-9 i carried by I E. hormaechei i were associated with IncHI2 plasmids,[7],[8] suggesting the role of IncHI2-type plasmids in the silent dissemination of I mcr-9 i gene. It is suggested that I qseB/qseC i system is vital for the induction of I mcr-9 i -mediated colistin resistance.[10],[11] Therefore, the lack of I qseB/qseC i might cause colistin susceptibility in ECL-90. Dear Editor: The worldwide prevalence of carbapenem-resistant I Enterobacteraceae i (CRE) has been well known, and colistin is one of the last-resort antibiotics for the CRE infections. [Extracted from the article]

Drug-resistant bacteria are becoming an increasingly widespread problem in the clinical setting. The current pipeline of antibiotics cannot provide satisfactory options for clinicians, which brought increasing attention to the development and application of non-traditional antimicrobial substances as alternatives. Metal ions, such as iron and zinc ions, have been widely applied to inhibit pathogens through different mechanisms, including synergistic action with different metabolic enzymes, regulation of efflux pumps, and inhibition of biofilm formation. Compared with traditional metal oxide nanoparticles, iron oxide nanoparticles (IONPs) and zinc oxide nanoparticles (ZnO-NPs) display stronger bactericidal effect because of their smaller ion particle sizes and higher surface energies. The combined utilization of metal NPs (nanoparticles) and antibiotics paves a new way to enhance antimicrobial efficacy and reduce the incidence of drug resistance. In this review, we summarize the physiological roles and bactericidal mechanisms of iron and zinc ions, present the recent progress in the research on the joint use of metal NPs with different antibiotics, and highlight the promising prospects of metal NPs as antimicrobial agents for tackling multidrug-resistant bacteria. [ABSTRACT FROM AUTHOR]

Abstract A unique nanostructure consisting of CNTs as carbon matrix, and were sequentially coated with silicon dioxide, N-doped porous carbon tube (NCT) and MnO 2 nanoflowers, the final CNT@NCT@MnO 2 composites with large internal voids between CNT and NCT. CNT@NCT@MnO 2 combines the nanostructural advantages of internal voids and the N-doped porous carbon, presenting fast diffusion paths for ions and electrons, high conductivity and large surface areas. When used as an anode material in supercapacitors, the CNT@NCT@MnO 2 tube-in-tube hierarchical nanostructure exhibite a remarkably excellent electrochemical behavior with a specific capacitance (Csp) of 210 F g−1 at the current density of 0.5 A g−1. Moreover, all-solid-state asymmetrical supercapacitors (ASCs) were fabricated using the CNT@NCT@MnO 2 composites as anode and the CNT@NCT as cathode, Na 2 SO 4 /PVA gel as the electrolyte and the separator. The all-solid-state ASCs also show the superior performance, such as high energy density of ∼14 Wh kg−1 and a power density of ∼3.6 kW kg−1. Graphical abstract The 3D CNT@NCT@MnO 2 composites have been synthesized by sacrificial template method. These kind of unique tube-in-tube nanostructures connected together make a 3D traffic network, which is important for the diffusion of electrolyte ions and the internal voids between CNT and NCT provide additional electroactive sites. When used as an anode material in supercapacitors, the CNT@NCT@MnO 2 tube-in-tube hierarchical nanostructure exhibite a remarkably excellent electrochemical behavior. Image 1 [ABSTRACT FROM AUTHOR]

MnMoO4 nanotubes of diameter about 120 nm were successfully synthesized by a single-spinneret electrospinning technique followed by calcination in air, and their structural, morphological, and electrochemical properties were studied with the aim to fabricate high-performance supercapacitor devices. The obtained MnMoO4 nanotubes display a 1D architecture with a porous structure and hollow interiors. Benefiting from intriguing structural features, the unique MnMoO4 nanotube electrodes exhibit a high specific capacitance, excellent rate capability, and cycling stability. As an example, the tube-like MnMoO4 delivers a specific capacitance of 620 F g−1 at a current density of 1 A g−1, and 460 F g−1 even at a very high current density of 60 A g−1. Remarkably, almost no decay in specific capacitance is found after continuous charge/discharge cycling for 10,000 cycles at 1 A g−1. An asymmetric supercapacitor fabricated from this MnMoO4 nanotubes and activated carbon displayed a maximum high energy density of 31.7 Wh kg−1 and a power density of 797 W kg−1, demonstrating a good prospect for practical applications in energy storage electronics. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) incorporated porous 3-dimensional (3D) CuS microspheres have been successfully synthesized via a simple refluxing method assisted by PVP. The composites are composed of flower-shaped CuS secondary microspheres, which in turn are assembled with primary nanosheets of 15-30 nm in thickness and fully integrated with CNT. The composites possess a large specific surface area of 189.6 m2 g−1 and a high conductivity of 0.471 S cm−1. As electrode materials for supercapacitors, the nanocomposites show excellent cyclability and rate capability and deliver an average reversible capacitance as high as 1960 F g−1 at a current density of 10 mA cm−2 over 10000 cycles. The high electrochemical performance can be attributed to the synergistic effect of CNTs and the unique microstructure of CuS. The CNTs serve as not only a conductive agent to accelerate the transfer of electrons in the composites, but also as a buffer matrix to restrain the volume change and stabilize the electrode structure during the charge/discharge process. The porous structure of CuS also helps to stabilize the electrode structure and facilitates the transport for electrons. [ABSTRACT FROM AUTHOR]

ABSTRACT is a widely used triazole fungicide and consists of four stereoisomers with 1R,2S, 1S,2R, 1R,2R, and 1S,2S configurations. The trans-enantiomeric pair ( 1R,2S-isomer and 1S,2R-isomer) is also called triadimenol-A and the cis-enantiomeric pair ( 1R,2R-isomer and 1S,2S-isomer) triadimenol-B. In this study, the stereoselective degradation and chiral stability of in two soils were investigated in details. The dissipation of technical , a 6:1 mixture of triadimenol-A and triadimenol-B, showed significant epimerization from triadimenol-A to triadimenol-B occurred along with the dissipation process. The degradation exhibited some stereoselectivity, resulting in a concentration order of 1S,2S > 1R,2R > 1R,2S > 1S,2R or 1S,2S > 1R,2R > 1S,2R > 1R,2S at the end of the 100 days incubation for Baoding soil or Wuhan soil, respectively. Further incubation of triadimenol-B revealed no epimerization, i.e. triadimenol-B was configurationally stable in soil, and 1R,2R-triadimenol degraded slightly slower in the former part and slightly faster in the later part of the incubation than 1S,2S-triadimenol. Moreover, by incubation of enantiopure 1S,2R-triadimenol and 1R,2S-triadimenol, the results documented the epimerization for each enantiomer occurred at both C-1 and C-2 positions. Finally, the present work also documented that the enantiomerization reaction for all the four stereoisomers was nearly negligible in the soils. Chirality 25:355-360:, 2013. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The enantioselective degradation of quizalofop-ethyl and its metabolite quizalofop-acid in two soils, a Wuhan acidic soil and a Baoding alkaline soil, was investigated. The dissipation of quizalofop-ethyl consisted of two phases, a rapidly deceasing first phase that lasted 1 day and a slowly decreasing second phase that extended till the end of the incubation. It is shown that S-quizalofop-ethyl degraded slightly faster than R-quizalofop-ethyl in the two soils. Further incubation of enantiopure enaniomers showed that quizalofop-ethyl was configurationally stable in soil. Quizalofop-acid was produced quickly, and its amount reached a maximum at 1-6 days time and then decreased slowly with half-lives ranging from 11 to 21 days. The results also showed that quizalofop-acid degraded faster in the acidic Wuhan soil than in the alkaline Baoding soil. At last, significant enantiomerization from S-quizalofop-acid to R-quizalofop-acid was observed, and the enantiomerization was fast, resulting in residues enriched with R-quizalofop-acid whatever racemic quizalofop-ethyl or pure enantiomers were initially applied in the soils. Chirality 24:552-557, 2012. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Abstract: Eight chiral pesticides, which were selected to cover different pesticide species and origins of chirality, were investigated to explore their chiral stability in organic solvents and water. Profenophos, fenamiphos, quizalofop-ethyl, dichlorprop-methyl (DCPP-methyl) and acetochlor were showed stable under all test conditions. However, significant racemization was observed for malathion, phenthoate and fenpropathrin in methanol, ethanol and water, but not in n-hexane, isopropanol, acetone or methylene chloride. The kinetic parameters (rate constant k and half-life T 1/2) of the abiotic racemization were calculated through a mathematical model of the first-order reaction. Furthermore, the extent of racemization varied among the solvents and was also affected by temperature dependence. The racemization of malathion, phenthoate and fenpropathrin in water was documented to be pH-dependent and took place more rapidly at pH 7.0 than at pH 5.8. The observed racemization was deduced to occur via a proton exchange process at the chiral center, and the relationship between the abiotic racemization and pesticide structure was further explored. Findings from this study are useful for better understanding enantioselectivity of chiral pesticides in environment and also for proper analysis, formulating or handling of enantiopure products. [ABSTRACT FROM AUTHOR]

• Neutralizing antibody evaluation helps to assess the risk of re-infection. • Some COVID-19 patients may not develop neutralizing antibody after recovery. • SARS-CoV-2 neutralizing antibody levels are correlated with COVID-19 disease severity. The emerging coronavirus disease 2019 (COVID-19) has become a serious global public health threat. With more and more recovered patients, it is urgently needed for evaluation of the neutralizing antibody (NAb) in these patients. In this study, we collected blood samples from 49 patients recently recovered from COVID-19. Serum NAbs were measured using a novel surrogate virus neutralization test (sVNT). Factors associated with NAb titers were analyzed using Ordinary Least Squares regression model. The median age of the study participants was 37 years (IQR, 30.0–54.5) and 55.1 % (27/49) of which were male. The median time to blood collection (for NAb analysis) from illness onset, viral clearance and discharge were 43.0 days (IQR, 36.0–50.0), 27.0 days (IQR, 20.5–37) and 17.0 days (IQR, 15.0–33.0), respectively. Patients had a median NAb titer of 1: 40 (IQR, 1:15–1:120). NAbs were not detected in two asymptomatic children who quickly cleared the virus. NAb titers were higher in patients with older age (p = 0.020), symptomatic infection (p = 0.044), more profound lung involvement (p＜0.001), abnormal C-reactive protein level (p＜0.01) and elevated lactate dehydrogenase (p = 0.019). Multivariable analysis revealed that severity of pneumonia and having comorbidity positively correlated with NAb titers in recovered patients (p = 0.02), while use of corticosteroids negatively impacted NAb titers (p = 0.01). Our study suggests that some COVID-19 patients may not have detectable NAb after recovery. SARS-CoV-2 NAb titers are positively correlated with severity of COVID-19 pneumonia. [ABSTRACT FROM AUTHOR]

Background: Environmental bacteria, nontuberculous mycobacteria (NTM), are recognized as one of the major human infection pathogens. NTM are prone to be mistaken as multidrug-resistant Mycobacterium tuberculosis and challenge our fight against TB. In addition, treatment of NTM per se is intractable. Remarkably, the distribution of NTM pathogenic species is geographically specific. Thus, it is very important to summarize the prevalent features and clinical symptoms of NTM pulmonary disease. However, In Nanjing district, southeast China, there is no such a report.Methods: Through investigating electronic medical records and analyzing data of clinical examination system (Lis), we retrospectively summarized the NTM species from 6012 clinical isolates from May 2017 to August 2018, and analyzed the association between NTM species and clinical symptoms.Results: Of 6012 clinical specimens, 1461 (24.3%) could grow in the MGIT 960 broth. Among these positive isolates, 1213 (83%) were M. tuberculosis, 22 (1.5%) were M. bovis, and 226 (15.5%) were NTM. After deducting redundancy, those NTM specimens were confirmed from 154 patients, among which, 87 (56.5%) patients met the full ATS/IDSA NTM disease criteria. The most common etiologic agent was M. intracellulare (70.1%). NTM infection was associated with age, based on which 68.6% male patients and 77.8% female patients were over 50 years old. The older patients were more likely to have hemoptysis, but the younger patients were more likely to manifest chest congestion. Male patients were more likely to have shortness of breath and females were more likely to have hemoptysis. The most common radiographic presentation of NTM pulmonary disease was bronchiectasis, accounting for 39.1%. Remarkably, multiple and thin-walled cavities were outstanding. The most frequent comorbidity of NTM disease was previous tuberculosis (64%), followed by clinical bronchiectasis (19.5%), HIV (19.5%), and 6.9% chronic obstructive pulmonary disease (COPD). There was no association between NTM species and clinical symptoms.Conclusion: This study retrospectively investigated the prevalence of NTM pulmonary disease in Nanjing district, southeast China. Similar to Beijing area, north China, M. intracellulare was the major pathogenic NTM species. Clinical symptoms of the disease were not species-specific. Previous TB and HIV infection immensely enhanced risk of NTM disease. [ABSTRACT FROM AUTHOR]