Structure and evolution patterns of contents of Chinese children's bestsellers

Children's books involve a large number of topics. This poster focuses on that in China, which is the fastest growing market for children's book in the world. This poster chose Dangdang.com, the biggest Chinese online bookstore, for data source to obtain children's bestsellers. The topic words of children's bestsellers were extracted from their brief introductions of the content on the website. With the aid of co-occurrence theory and tools of social network analysis and visualization, the distribution, correlation structures, and evolution patterns of topics were revealed and visualized. This poster shows that topics of Chinese children's bestsellers are broad and relatively concentrated, but their distribution is unbalanced. There are four distinguished topic communities (Living, Animal, World, and Child) in terms of centrality and maturity, and they all establish their individual systems and tend to be mature. The evolution of these communities tends to be stable with powerful continuity

A novel colorimetric biosensor based on non-aggregated Au@Ag core–shell nanoparticles for methamphetamine and cocaine detection

We report a novel colorimetric biosensor based on non-aggregation Au@Ag core-shell nanoparticles to detect methamphetamine and cocaine. The biosensor consisted of a reporter probe (RP) that is a specific single-stranded DNA (ssDNA) sequence coated on Au@Ag nanoparticles, a capture probe (CP) conjugated with magnetic beads, and an illicit drug-binding DNA aptamer (Apt). Au@Ag nanoparticles were synthesized by seed growth and characterized by scanning electron microscope (SEM), high-resolution transmission electron microscopy (HR-TEM), and UV–vis spectra. Methamphetamine (METH) was used as an example to evaluate the feasibility of the biosensor and to optimize the detection conditions. We demonstrated that this sensing platform was able to detect as low as 0.1 nM (14.9 ng L−1) METH with a negligible interference from other common illicit drugs. Various concentrations of METH were spiked into urines, and the biosensor yielded recoveries more than 83.1%. In addition, the biosensor also showed a high sensitivity to detect cocaine. These results demonstrated that our colorimetric sensor holds promise to be implemented as a visual sensing platform to detect multiple illicit drugs in biological samples and environmental matrices

Naturally Occurring Core Protein Mutations Compensate for the Reduced Replication Fitness of a Lamivudine-Resistant HBV Isolate

Hepatitis B virus (HBV) replicates its DNA genome through reverse transcription of an RNA intermediate. The lack of proofreading capacity of the viral DNA polymerase results in a high mutation rate of HBV genome. Under the selective pressure created by the nucleos(t)ide analogue (NA) antiviral drugs, viruses with resistance mutations are selected. However, the replication fitness of NA-resistant mutants is markedly reduced compared to wild-type. Compensatory mutations in HBV polymerase, which restore the viral replication capacity, have been reported to arise under continuous treatment with lamivudine (LMV). We have previously identified a highly replicative LMV-resistant HBV isolate from a chronic hepatitis B patient experiencing acute disease exacerbation. Besides the common YMDD drug-resistant mutations, this isolate possesses multiple additional mutations in polymerase and core regions. The transcomplementation assay demonstrated that the enhanced viral replication is due to the mutations of core protein. Further mutagenesis study revealed that the P5T mutation of core protein plays an important role in the enhanced viral replication through increasing the levels of capsid formation and pregenomic RNA encapsidation. However, the LMV-resistant virus harboring compensatory core mutations remains sensitive to capsid assembly modulators (CpAMs). Taken together, our study suggests that the enhanced HBV nucleocapsid formation resulting from core mutations represents an important viral strategy to surmount the antiviral drug pressure and contribute to viral pathogenesis, and CpAMs hold promise for developing the combinational antiviral therapy for hepatitis B

Low-cost virtual instrumentation system of an energy-dispersive X-ray spectrometer for a scanning electron microscope

The paper describes an energy-dispersive X-ray spectrometer for a scanning electron microscope (SEM-EDXS). It was constructed using the new architecture of a virtual instrument (VI), which is low-cost, space-saving, fast and flexible way to develop the instrument. Computer-aided teaching (CAT) was used to develop the instrument and operation rather than a traditional instrument technique. The VI was designed using the object-oriented program language C++ and compact programmable logical devices (CPLD). These include spectra collection and processing, quantitative analysis and X-ray-intensity distribution analysis. The procedure is described in detail. The VI system gives an e¡ective and user-friendly human interface for the whole analytical task. Some examples are described

Auto-analysis system for graphite morphology of grey cast iron

The current method to classify graphite morphology types of grey cast iron is based on traditional subjective observation, and it cannot be used for quantitative analysis. Since microstructures have a great effect on the mechanical properties of grey cast iron and different types have totally different characters, six types of grey cast iron are discussed and an image-processing software subsystem that performs the classification and quantitative analysis automatically based on a kind of composed feature vector and artificial neural network (ANN) is described. There are three kinds of texture features: fractal dimension, roughness and two-dimension autoregression, which are used as an extracted feature input vector of ANN classifier. Compared with using only one, the checkout correct precision increased greatly. On the other hand, to achieve the quantitative analysis and show the different types clearly, the region segmentation idea was applied to the system. The percentages of the regions with different type are reported correctly. Furthermore, this paper tentatively introduces a new empirical method to decide the number of ANN hidden nodes, which are usually considered as a difficulty in ANN structure decision. It was found that the optimum hidden node number of the experimental data was the same as that obtained using the new method

A novel biosensor based on Au@Ag core-shell nanoparticles for sensitive detection of methylamphetamine with surface enhanced Raman scattering

We describe a novel biosensing strategy for sensitive detection of methylamphetamine (MAMP) based on surface enhanced Raman scattering (SERS) by the mediation of spacing between 4-mercaptobenzoic acid (4-MBA) labeled Au@Ag core-shell nanoparticles (Au@Ag). To achieve a favorable SERS substrate, Au@Ag shell-core nanoparticle was synthesized with seeds growth method and well characterized by SEM, TEM and UV-vis spectrometer. The uniform Au@Ag shows an excellent dispersion ability for SERS detection. Under the optimized conditions, the novel biosensor shows a good logarithm linear correlation with the concentration of MAMP ranging from 0.5 ppb to 40 ppb (R = 0.986), with a limit of detection at 0.16 ppb of MAMP (3σ). Furthermore, our biosensors hold an excellent selectivity, demonstrated by the negligible interference from the detection of other illicit drugs and metabolites. The concentrations determined with our biosensor from spiked MAMP in human urine sample fell within the same range with the results from mass spectrometry. This indicates that our sensor has a clear potential for the rapid detection of illicit drug in real samples

Inferring subsidence characteristics in Wuhan (China) through multitemporal InSAR and hydrogeological analysis

Wuhan (China) is facing severe consolidation subsidence of soft soil and karst collapse hazards. To quantitatively explore the extent and causes of land subsidence in Wuhan, we performed multitemporal interferometry (MTI) analysis using synthetic aperture radar (SAR) data from the TerraSAR-X satellite from 2013 to 2017 and the Sentinel-1A satellite from 2015 to 2017. MTI results reveal four major subsidence zones in Wuhan, namely, Hankou (exceeding −6 cm/yr), Xudong-Qingshan (−3 cm/yr), Baishazhou-Jiangdi (−3 cm/yr), and Jianshe-Yangluo (−2 cm/yr). Accuracy assessment using 106 levelling benchmarks and cross-validation between the two InSAR-based results indicate an overall root-mean-square error (RMSE) of 2.5 and 3.1 mm/yr, respectively. Geophysical and geological analyses suggest that among the four major subsiding zones, Hankou, Xudong-Qingshan, and Jianshe-Yangluo are located in non-karstic soft soil areas, where shallow groundwater (< 30 m) declines driven by engineering dewatering and industrial water depletion contribute directly to soft soil compaction. Subsidence in the Baishazhou-Jiangdi zone develops in the karst terrain with abundant underground caves and fissures, which are major natural factors for gradual subsidence and karst collapse. Spatial variation analysis of the geological conditions indicates that the stage of karst development plays the most important role in influencing kart subsidence, followed by municipal construction, proximity to major rivers, and overlying soil structure. Moreover, land subsidence in this zone is affected more via coupling effects from multiple factors. Risk zoning analysis integrating subsidence horizontal gradient, InSAR deformation rates, and municipal construction density show that the high-risk areas in Wuhan are mainly distributed in the Tianxingzhou and Baishazhou-Jiangdi zone, and generally spread along the metro lines. © 202

Turning dead leaves into an active multifunctional material as evaporator, photocatalyst, and bioplastic

Large numbers of leaves fall on the earth each autumn. The current treatments of dead leaves mainly involve completely destroying the biocomponents, which causes considerable energy consumption and environmental issues. It remains a challenge to convert waste leaves into useful materials without breaking down their biocomponents. Here, we turn red maple dead leaves into an active three-component multifunctional material by exploiting the role of whewellite biomineral for binding lignin and cellulose. Owing to its intense optical absorption spanning the full solar spectrum and the heterogeneous architecture for effective charge separation, films of this material show high performance in solar water evaporation, photocatalytic hydrogen production, and photocatalytic degradation of antibiotics. Furthermore, it also acts as a bioplastic with high mechanical strength, high-temperature tolerance, and biodegradable features. These findings pave the way for the efficient utilization of waste biomass and innovations of advanced materials