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Segmented and pixelated detectors on scanning transmission electron microscopes enable the complex specimen transmission function to be reconstructed. Imaging the transmission function is key to interpreting the electric and magnetic properties of the specimen, and as such four-dimensional scanning transmission electron microscopy (4D-STEM) imaging techniques are crucial for our understanding of functional materials. Many of the algorithms used in the reconstruction of the transmission function rely on the multiplicative approximation and the (weak) phase object approximation, which are not valid for many materials, particularly at high resolution. Herein, we study the breakdown of simple phase imaging in thicker samples. We demonstrate the behavior of integrated center of mass imaging, single-side band ptychography, and Wigner distribution deconvolution over a thickness series of simulated GaN 4D-STEM datasets. We further give guidance as to the optimal focal conditions for obtaining a more interpretable dataset using these algorithms.

A fluorescence visual sensing method for glyphosine based on nitrogen-doped biomass carbon quantum dot (N-CQD) paper-based sensor was designed and fabricated.

Zhiguang Li,1 Xu Si,1 Zhiyuan Ding,1 Xiao Li,1 Shuai Zheng,1 Yuxin Wang,1 Hua Wei,1 Yige Guo,2 Wei Zhang3 1School of Economics and Management, Anhui University of Chinese Medicine, Hefei, Anhui, People’s Republic of China; 2King’s Business School, King’s College London, London, UK; 3School of Information Engineering, Anhui University of Chinese Medicine, Hefei, Anhui, People’s Republic of ChinaCorrespondence: Hua WeiSchool of Economics and Management, Anhui University of Chinese Medicine, Hefei, Anhui, People’s Republic of ChinaTel +86 551-68129006Email weihua@ahtcm.edu.cnWei ZhangSchool of Information Engineering, Anhui University of Chinese Medicine, Hefei, Anhui, People’s Republic of ChinaTel +86 551-68129224Email zhangwei900316@163.comPurpose: This paper aims to measure the operating efficiency of China’s basic pension insurance from 2014 to 2019 in 31 provinces.Methods: The three-stage DEA model was used to evaluate the operating efficiency of basic pension insurance in 31 provinces.Results: On the whole, the operating efficiency of China’s basic pension insurance was at a high level, but there was still room for improvement. GDP, urbanization level and scale of government public expenditure had a positive impact on the operating efficiency of regional basic pension insurance. In contrast, the old-age dependency ratio had a significant negative effect. There were noticeable regional differences in the operating efficiency of China’s basic pension insurance, which showed a pattern of Central (0.742) >Eastern (0.689) >Western (0.505) after removing the influence of environmental variables.Conclusion: This study systematically analyzes the impact of external environmental regulations on China’s basic pension insurance’s operating efficiency and provides decision-making references for further improving the operating efficiency of China’s basic pension insurance. In order to further optimize the allocation of basic endowment insurance, this paper proposes the following countermeasures and suggestions: (1) broaden investment channels and improve the investment efficiency; (2) increase supervision of social security departments and strengthen information disclosure; (3) unify the management of social basic pension insurance.Keywords: three-stage DEA, China’s pension insurance, operating efficiency, technical efficiency

DNA origami technology has proven to be an excellent tool for precisely manipulating molecules and colloidal elements in a three-dimensional manner. However, fabrication of single crystals with well-defined facets from highly programmable, complex DNA origami units is a great challenge. Here, we report the successful fabrication of DNA origami single crystals with Wulff shapes and high yield. By regulating the symmetries and binding modes of the DNA origami building blocks, the crystalline shapes can be designed and well-controlled. The single crystals are then used to induce precise growth of an ultrathin layer of silica on the edges, resulting in mechanically reinforced silica-DNA hybrid structures that preserve the details of the single crystals without distortion. The silica-infused microcrystals can be directly observed in the dry state, which allows meticulous analysis of the crystal facets and tomographic 3D reconstruction of the single crystals by high-resolution electron microscopy., DNA origami is a valuable tool for precise manipulation of molecules in a three dimensional manner, but the design and assembly of origami units into single crystals is challenging. Here, the authors report successful fabrication of DNA origami single crystals with Wulff shapes, and regulation of their shapes by changing the symmetry and binding modes of DNA origami building blocks.

Programmable assembly of nanoparticles (NPs) into well-defined architectures has attracted attention because of tailored properties resulting from coupling effects. However, general and precise approaches to control binding modes between NPs remain a challenge owing to the difficulty in manipulating the accurate positions of the functional patches on the surface of NPs. Here, a strategy is developed to encage spherical NPs into pre-designed octahedral DNA origami frames (DOFs) through DNA base-pairings. The DOFs logically define the arrangements of functional patches in three dimensions, owing to the programmability of DNA hybridization, and thus control the binding modes of the caged nanoparticle with designed anisotropy. Applying the node-and-spacer approach that was widely used in crystal engineering to design coordination polymers, patchy NPs could be rationally designed with lower symmetry encoded to assemble a series of nano-architectures with high-order geometries.

The present study reports the development of an electrochemical sensor based on sulfobutylether-β-cyclodextrin modified reduced graphene oxide hybrid (SBCD-rGO) for simultaneous detection of nitrophenol isomers. First, SBCD-rGO hybrid was synthesized and detailed characterized. Afterwards, a sensor was fabricated via the modification of glassy carbon electrode (GCE) with SBCD-rGO, and its electrochemical detection performances were also investigated. Then, the constructed electrochemical sensor was applied to detect nitrophenol isomers by voltammetry analysis. The results suggested that the sensitivities were 389.26, 280.88 and 217.19 μA/mM for p-nitrophenol (p-NP), m-nitrophenol (m-NP), and o-nitrophenol (o-NP), respectively, and their corresponding detection limits were all about 0.05 μM. Significantly, the combination of voltammetry analysis with the constructed sensor and data analysis by multiple linear regression realized the simultaneous detection of nitrophenol isomers.

Crystallization is one of the most fundamental processes for both solid inorganic and organic materials in nature. The classical crystallization model mainly involves the monomer-by-monomer addition of simple chemical species. Recently, nanoparticle attachment has been realized as an important mechanism of crystallization in comparatively low-temperature aqueous natural and synthetic systems. However, no evidence of crystallization by particle attachment has been reported in petrologically important melts. In this study, we described spherical (Mg,Fe)-oxides with a protrusion surface in a shock-induced melt pocket from the martian meteorite Northwest Africa 7755. Transmission electron microscopic observations demonstrate that the (Mg,Fe)-oxides are structure-coherent intergrowth of ferropericlase and magnesioferrite. The magnesioferrite is mainly present adjacent to the interface between (Mg,Fe)-oxides spherules and surrounding silicate glass, but not in direct contact with the silicate glass. Thermodynamic and kinetic considerations suggest that development of the spherical (Mg,Fe)-oxides can be best interpreted with crystallization by particle attachment and subsequent Ostwald ripening. This indicates that crystallization by particle attachment can also take place in high-temperature melts and has potential implications for understanding the nucleation and growth of early-stage crystals in high-temperature melts, such as chondrules in the solar nebula, erupted volcanic melts, and probably even intrusive magmas.

Three dimensional scaffolded DNA origami with inorganic nanoparticles has been used to create tailored multidimensional nanostructures. However, the image contrast of DNA is poorer than those of the heavy nanoparticles in conventional transmission electron microscopy at high defocus so that the biological and non-biological components in 3D scaffolds cannot be simultaneously resolved using tomography of samples in a native state. We demonstrate the use of electron ptychography to recover high contrast phase information from all components in a DNA origami scaffold without staining. We further quantitatively evaluate the enhancement of contrast in comparison with conventional transmission electron microscopy. In addition, We show that for ptychography post-reconstruction focusing simplifies the workflow and reduces electron dose and beam damage.

Zhiguang Li,1 Wanying Zhang,1 Aijie Kong,1 Zhiyuan Ding,1 Hua Wei,1 Yige Guo2 1School of Economics and Management, Anhui University of Chinese Medicine, Hefei, Anhui, People’s Republic of China; 2King’s Business School, King’s College London, London, UKCorrespondence: Hua WeiSchool of Economics and Management, Anhui University of Chinese Medicine, 350 Longzihu Road, Xinzhan District, Hefei 230012, People’s Republic of ChinaTel +86-551-68129224Email weihua@ahtcm.edu.cnPurpose: This paper aims to measure the technical efficiency of China’s medical and health institutions from 2012 to 2017 and outline the path to achieve high-quality development.Methods: The DEA-Malmquist was used to evaluate the total factor productivity of medical and health institutions in 31 provinces. A fuzzy set Qualitative Comparative Analysis (fsQCA) was used for configuration analysis of determinants affecting technical efficiency.Results: The average total factor productivity (TFP) of those institutions was 0.965, namely TFP declined averagely by 3.5% annually. The efficiency change and the technical change were 0.998 and 0.967, respectively. The realization paths of high technical efficiency are composed of high fatality rate and high financial allocation-led, high population density and high GDP-led. Low dependency ratio and low financial allocation-led, low fatality rate and low financial allocation-led are the main reasons for low technical efficiency.Conclusion: Due to advanced medical technology and economic development, major cities like Beijing, Shanghai, and Guangdong have attracted a large number of high-level health personnel, achieving long-term and stable health business growth. Hubei, Anhui, and Sichuan also have made rapid development of health care through appropriate financial subsidies and policy supports. The technical changes in Qinghai, Yunnan, and Inner Mongolia are higher than the national average, but the operation and management level of the medical and health institutions is relatively weak. Henan, Jiangxi, and Heilongjiang have a prominent performance in the efficiency change, but the technical change is weaker than the national average.Keywords: China’s medical and health institutions, DEA-malmquist, fsQCA, efficiency, configuration

Image based machine learning is widely used for Alzheimer’s disease (AD) identification, however, traditional two dimensional (2D) image processing techniques may lead to spatial information lost. In this paper, a spatial pyramid based three dimensional (3D) histogram of oriented gradient (HOG) feature extraction method is proposed to increase spatial discrimination. Then a simple f-divergence based dimension reduction method was used to extract principal features in HOG, which solved the problem of high dimensionality of variables with relatively small number of subjects. Experimental results illustrated the effectiveness of proposed method.

Alzheimer's Disease (AD) is a progressive irreversible neurodegeneration disease and thus timely identification is critical to delay its progression.In this work, we focus on the traditional branch to design discriminative feature extraction and selection strategies to achieve explainable AD identification. Specifically, a spatial pyramid based three-dimensional histogram of oriented gradient (3D-HOG) feature learning method is proposed. Both global and local texture changes are included in spatial pyramid 3D-HOG (SPHOG) features for comprehensive analysis. Then a modified wrapper-based feature selection algorithm is introduced to select the discriminative features for AD identification while reduce feature dimensions.Discriminative SPHOG histograms with various resolutions are selected, which can represent the atrophy characteristics of cerebral cortex with promising performance. As subareas corresponding to selected histograms are consistent with clinical experience, explanatory is emphasized and illustrated with Hippocampus.Experimental results illustrate the effectiveness of the proposed method on feature learning based on samples obtained from common dataset and a clinical dataset. The proposed method will be useful for further medical analysis as its explanatory on other region-of-interests (ROIs) of the brain for early diagnosis of AD.

A glassy carbon electrode (GCE) modified by a hybrid, macroporous carbon (MPC) functionalized with triazine bridged covalent organic polycalix[4]arenes (CalCOP) (CalCOP-MPC), has been fabricated and utilized for simultaneous detection of nitrophenols (NP). The obtained CalCOP-MPC were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS), which confirmed that MPC had functionalized with CalCOP successfully. Benefiting from the synergistic supramolecular effect of macrocyclic receptor of CalCOP and the excellent electrical properties of MPC, the anodic peaks of o-nitrophenol (o-NP), m-nitrophenol (m-NP), and p-nitrophenol (p-NP) in their mixture can be well separated by the prepared electrode. Differential pulse voltammetry (DPV) measurements at CalCOP-MPC/GCE revealed that the linear ranges of NP isomers were all 1–400 μM, and the detection limit limits were 0.383 μM, 0.122 μM, and 0.212 μM for o-NP, m-NP, and p-NP, respectively. Moreover, the prepared modified electrodes showed a relatively good selectivity and stability, implying the prospect for detecting NP in real environmental samples.

The faults caused by transmission line icing seriously influence normal operation of power system. The application of superhydrophobic material on the anti-icing of transmission and distribution electricity equipment has caused widely concern in recent years. This paper takes icing flashover tests in a multifunctional artificial chamber on glass plates with superhydrophobic coatings and uncoated control group, respectively. The different characteristics between superhydrophobic surface and hydrophilic in ice morphology, and the flashover voltage changed with icing time are obtained in the experiments. According to analysis of the development of arc on ice surface, this paper builds a flashover equivalent model of ice covered superhydrophobic surface.

Background: Tuberculin skin test (TST) has been the most commonly used test for diagnosis of tuberculosis (TB) infection in China for many years, because of well-established algorithms for test interpretation and a good cost-effectiveness. To our knowledge , there is no report or guideline on the influence of varicella vaccine on the sensitivity of TST in China. This paper aims to explore the effect of live attenuated varicella vaccine on the sensitivity of TST.Methods: A retrospective cohort study was carried out in a high school in Wuxi, Jiangsu province in 2020. TST and emergency varicella vaccine were administered to students in grade one of the high school which had both TB and varicella cases. The mean diameter of induration of TST were compared between 73d before varicella vaccine, 9d and 120d after varicella vaccine respectively. The retrospective cohort study was used to analyze the effect of live attenuated varicella vaccine on TST.Results: There were 45 students in the class of the high school had three TST, and 22 of them were vaccinated varicella. After 9 days of varicella vaccination, the mean diameter of induration was significantly smaller than that before the vaccination of 73 days and after the vaccination of 120 days (pConclusions: Live attenuated varicella vaccine may temporarily affect the sensitivity of tuberculin skin test.

Monolayer VS2 has two common stable phases, 2H-phase and 1T-phase. Based on first-principles calculations, we studied the optical properties of 2D-VS2, including their dielectric functions, absorption coefficients, refraction indexes and energy loss functions. Also, we fully analyzed the relationship between the electronic structure and the optical characteristics of 2D-VS2. We found that the differences of density of states are the fundamental reasons for the differences of the two phase optical absorption behavior.

This work reports an enantioselective electrochemical sensor toward tyrosine (Tyr) enantiomers based on macroporous carbon embedded with sulfato-β-cyclodextrin (MPC-SCD) hybrid. First, MPC-SCD hybrid was synthesized via adsorption of sulfato-β-cyclodextrin (SCD) by macroporous carbon (MPC) in aqueous solution, and characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). Subsequently, an enantioselective electrochemical sensor was fabricated by modifying glassy carbon electrode (GCE) with MPC-SCD hybrid, and its electrochemical performances were characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammograms (CV). Furthermore, the electrochemical sensor was utilized for chiral analysis toward Tyr enantiomers by differential pulse voltammograms (DPV). The peak currents of Tyr enantiomers increased linearly with increasing concentrations over the range of 1–500 μM. In addition, the sensitivity were calculated as 84.59 and 73.02 μA/mM for D-Tyr and L-Tyr, respectively, and the detection limits were 0.20 and 0.26 μM. Furthermore, multiple linear regression (MLR) chemometrics modeling method was used for simultaneously analysis of Tyr enantiomers. The presented sensor could provide a promising protocol for designing novel electrochemical platforms in the field of chiral analysis.

A series of 1,4-disubstituted 1,2,3-triazoles containing formyl was synthesized from a variety of readily available nitrobenzaldehydes and alkynes via a convenient one-pot, click-SNAr reaction with moderate to excellent yields. The reactions were easily carried out in hexamethyl phosphoramide in the absence of a base at 60 °C.

We report a method for quantitative phase recovery and simultaneous electron energy loss spectroscopy analysis using ptychographic reconstruction of a data set of "hollow" diffraction patterns. This has the potential for recovering both structural and chemical information at atomic resolution with a new generation of detectors.

Hydrogen production is the key step for the future hydrogen economy. As a promising H2 production route, electrolysis of water suffers from high overpotentials and high energy consumption. This study proposes an N-doped CoP as the novel and effective electrocatalyst for hydrogen evolution reaction (HER) and constructs a coupled system for simultaneous hydrogen and sulfur production. Nitrogen doping lowers the d-band of CoP and weakens the H adsorption on the surface of CoP because of the strong electronegativity of nitrogen as compared to phosphorus. The H adsorption that is close to thermos-neutral states enables the effective electrolysis of the HER. Only -42 mV is required to drive a current density of -10 mA cm-2 for the HER. The oxygen evolution reaction in the anode is replaced by the oxidation reaction of Fe2+ , which is regenerated by a coupled H2 S absorption reaction. The coupled system can significantly reduce the energy consumption of the HER and recover useful sulfur sources.

A series of 1,4-disubstituted 1,2,3-triazoles containing formyl was synthesized from a variety of readily available nitrobenzaldehydes and alkynes via a convenient one-pot, click-SNAr reaction with moderate to excellent yields. The reactions were easily carried out in hexamethyl phosphoramide in the absence of a base at 60 °C.