16S Next-generation sequencing and quantitative PCR reveal the distribution of potential pathogens in the Liaohe Estuary

The existence of potentially pathogenic bacteria seriously threatens aquatic animals and human health. Estuaries are closely related to human activities, and the detection of pathogens is important for aquaculture and public health. However, monitoring only indicator microorganisms and pathogens is not enough to accurately and comprehensively estimate water pollution. Here, the diversity of potentially pathogenic bacteria in water samples from the Liaohe estuary was profiled using 16S next-generation sequencing (16S NGS) and quantitative polymerase chain reaction (qPCR) analysis. The results showed that the dominant genera of environmental pathogens were Pseudomonas, Vibrio, Mycobacterium, Acinetobacter, Exiguobacterium, Sphingomonas, and Legionella, and the abundance of enteric pathogens was significantly less than the environmental pathogens, mainly, Citrobacter, Enterococcus, Escherichia-Shigella, Enterobacter, Bacteroides. The qPCR results showed that the 16S rRNA genes of Vibrio were the most abundant, with concentrations between 7.06 and 9.48 lg copies/L, followed by oaa gene, fliC gene, trh gene, and uidA gene, and the temperature and salinity were the main factors affecting its abundance. Variance partitioning analysis (VPA) analysis of spatial factors on the potential pathogen’s distribution (19.6% vs 5.3%) was greater than environmental factors. In addition, the co-occurrence analysis of potential pathogens in the estuary revealed significant co-occurrence among the opportunistic pathogens Testosteronemonas, Brevimonas vesicularis, and Pseudomonas putida. Our findings provide an essential reference for monitoring and occurrence of potentially pathogenic bacteria in estuaries

Synthesis and Electrochemical Properties of LiNi0.5Mn1.5O4 Cathode Materials with Cr3+ and F− Composite Doping for Lithium-Ion Batteries

Abstract A Cr3+ and F− composite-doped LiNi0.5Mn1.5O4 cathode material was synthesized by the solid-state method, and the influence of the doping amount on the material’s physical and electrochemical properties was investigated. The structure and morphology of the cathode material were characterized by XRD, SEM, TEM, and HRTEM, and the results revealed that the sample exhibited clear spinel features. No Cr3+ and F− impurity phases were found, and the spinel structure became more stable. The results of the charge/discharge tests, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) test results suggested that LiCr0.05Ni0.475Mn1.475O3.95F0.05 in which the Cr3+ and F− doping amounts were both 0.05, had the optimal electrochemical properties, with discharge rates of 0.1, 0.5, 2, 5, and 10 C and specific capacities of 134.18, 128.70, 123.62, 119.63, and 97.68 mAh g−1 , respectively. After 50 cycles at a rate of 2 C, LiCr0.05Ni0.475Mn1.475O3.95F0.05 showed extremely good cycling performance, with a discharge specific capacity of 121.02 mAh g−1 and a capacity retention rate of 97.9%. EIS test revealed that the doping clearly decreased the charge-transfer resistance

Synthesis of Spherical Silver-coated Li4Ti5O12 Anode Material by a Sol-Gel-assisted Hydrothermal Method

Abstract ᅟ Ag-coated spherical Li4Ti5O12 composite was successfully synthesized via a sol-gel-assisted hydrothermal method using an ethylene glycol and silver nitrate mixture as the precursor, and the influence of the Ag coating contents on the electrochemical properties of its was extensively investigated. X-ray diffraction (XRD) analysis indicated that the Ag coating does not change the spinel structure of Li4Ti5O12. The electrochemical impedance spectroscopy (EIS) analyses demonstrated that the excellent electrical conductivity of the Li4Ti5O12/Ag resulted from the presence of the highly conducting silver coating layer. Additionally, the nano-thick silver layer, which was uniformly coated on the particles, significantly improved this material’s rate capability. As a consequence, the silver-coated micron-sized spherial Li4Ti5O12 exhibited excellent electrochemical performance. Thus, with an appropriate silver content of 5 wt.%, the Li4Ti5O12/Ag delivered the highest capacity of 186.34 mAh g−1 at 0.5C, which is higher than that of other samples, and maintained 92.69% of its initial capacity at 5C after 100 cycles. Even at 10C after 100 cycles, it still had a capacity retention of 89.17%, demonstrating remarkable cycling stability. Trial registration ISRCTN NARL-D-17-0056

The influencing factors of biomedical R&D cooperation in three major urban agglomerations of China based on cooperative patents.

Due to the particularity of biomedical industry, it has become necessary for biomedical enterprises to seek innovative research and development (R&D) cooperation to maintain advanced technologies and products in multiple fields. Under such circumstance, the biomedical industry has gradually formed a certain cluster to promote the development of the industry. So far, the biomedical industry cluster has formed in China, mainly within the Yangtze River Delta, Pearl River Delta, and Beijing-Tianjin-Hebei three urban agglomerations. Within the industrial clusters, the frequency of innovation cooperation among enterprises, universities, research institutions, and other relevant organizations in the biomedical area is high, and the capacity for innovation cooperation is strong as well. This paper used the representative cross-section data of cooperative patents from the medical science and technology patent database of China National Knowledge Infrastructure (CNKI), researching the R&D cooperation within the three major urban agglomerations in China from 2008 to 2016 (Yangtze River Delta Urban Agglomeration, Pearl River Delta Urban Agglomeration, Beijing-Tianjin-Hebei Urban Agglomeration) on total 36 cities' spatial pattern characteristics of biomedical cooperation and the influencing factors. The spatial interaction model was used to study the spatial, economic, political, and R&D influencing factors of cross-city cooperation. The degree of aggregation showed that cross-city R&D cooperation mainly occurred in well-developed and central cities of urban agglomerations. Econometric results revealed that spatial, economic, political, and R&D bias factors did have a significant impact on the frequency of biomedical R&D cooperation across cities

Heterogeneous activation of peroxymonosulfate by hierarchically porous cobalt/iron bimetallic oxide nanosheets for degradation of phenol solutions

Bimetallic oxide nanomaterials have received much attention owing to their competing performances in heterogeneous catalysis. Herein, hierarchically porous cobalt-iron oxide nanosheets were successfully prepared using NaBH4 as a reductant and high concentration cetyl trimethylammonium bromide (CTAB) as a surfactant. Characterization results showed that the CTAB would induce the form of a bilayer structure while NaBH4 would promote the generation of enriched oxygen vacancies. As a result, the as-prepared Co1Fe1-300 exhibited high activity for activating peroxymonosulfate and achieved 100% phenol degradation within 30 min. This excellent catalytic activity can be attributed to its hierarchically porous structure, more active sites and oxygen vacancies. Co leaching test indicated that the Co1Fe1-300 exhibited excellent catalytic stability. Mechanistic studies suggested that two main degradation pathways were involved during phenol oxidation process, in which SO4•− played a significant role. This work may offer a novel strategy for the synthesis of high activity catalysts and a promising system for the remediation of environmental pollutant. © 2020 Elsevier Lt

Crystal Structure Control of ZnxCd1-xS Alloyed Nanocrystals and Structural Dependent Fluorescence Properties

Crystal structure control is so important to the fluorescence properties that each element should be considered carefully. In conventional synthesis of ZnxCd1-xS alloyed nanocrystals (NCs), most of studies focus on ligand-surface interaction on the formation of either zinc blende or wurtzite ZnxCd1-xS nanocrystals, instead of the reactant source. In this work, mixed crystal phase was found easily in ZnxCd1-xS alloyed NCs when reaction proceeded at high Zn/Cd source ratio condition. Therefore, we regulate the Zn/Cd ratio to obtain relative pure zinc-blende structure, and study the influence of structure change on the fluorescence properties. Further, we have proposed a two-step ZnS coating method to acquire ZnxCd1-xS/ZnS NCs with separated crystal-phase between core and shell. Compared with maximum QY of 81% for ZnxCd1-xS/ZnS NCs synthesized by conventional one-step coating method, the performance of the optimized NCs has significantly improved with maximum QY of 93%