Search

DDT and its metabolites (DDTs) can induce estrogenic effects. Previous mechanistic investigations mainly concentrated on activating the genomic transcription of estrogen receptor (ER) pathways. Here, we identified whether estrogen-related receptor γ (ERRγ), an orphan nuclear receptor, is a potential target of DDTs by receptor binding, transcriptional activity, and receptor-mediated pathway assays. Fluorescence polarization-based binding assays showed that all eight DDTs bound to ERRγ directly, with

The high rate performance of a battery requires the anode to be conductive not just ionically but also electronically. This criterion has significantly stimulated the study on 3D porous topological metals composed of nonmetal atoms with a light mass. Many carbon-based 3D topological metals for batteries have been reported, while similar work for 3D boron remains missing. Here, we report the first study of a 3D boron topological metal as an anode material for Li or Na ions. Based on systematic calculations, we found that the reported 3D topological metal H-boron composed of B4 cluster shows a low mass density (0.91 g/cm3) with multiple adsorption sites for Li and Na ions due to the electron-deficient feature of boron, leading to an ultrahigh specific capacity of 930 mAh/g for Li and Na ions with a small migration barrier of 0.15 and 0.22 eV, respectively, and small volume changes of 0.6% and 9.8%. These intriguing features demonstrate that B-based 3D topological quantum porous materials are worthy of further study for batteries.

All-solid-state sodium-ion batteries (ASIBs) are promising candidates for large-scale energy storage applications. To build such a battery system, efficient solid-state electrolytes (SSEs) with high sodium ionic conductivity at room temperature and good electrochemical stability as well as interface compatibility are required. In this work, using density functional theory combined with molecular dynamics simulation and a phase diagram, we have studied the potential of yttrium halide-based materials (Na

Sensitive detection of phosphorylated histone H2AX (γH2AX) in cells as a biomarker of DNA double-strand breaks has great significance in the field of molecular toxicology and life science research. However, current γH2AX detection methods require labor- and time-consuming steps. Here, for the first time, we designed a simple electrochemiluminescence (ECL) immunoassay integrated with a microplate-based sensor array to realize sensitive and high-throughput detection of γH2AX in cell lysates. Under the optimized conditions, this ECL immunosensor array could linearly respond to γH2AX concentrations in the range from 2 × 102 to 1 × 105 pg/mL. In addition, our approach possessed excellent specificity and satisfactory reproducibility, and its practicality was verified in real cell lysates. The whole process including instrumental and manual operation was completed in no more than 3 h. This study provides a convenient and rapid alternative method for the sensitive quantification of γH2AX, which shows promising application in high-throughput screening of genotoxic chemicals and drug candidates.

Motivated by the recent synthesis of three-dimensional (3D) porous borocarbonitride (Angew. Chem., Int. Ed., 2019, 58, 6033–6037), we propose a porous 3D-BC2N structure composed of BC2N nanoribbons. On the basis of detailed theoretical analysis and calculations, we find that the porous 3D-BC2N is dynamically stable with cohesive energy of 9.52 eV per atom and a Zener anisotropic factor of 2.72. This system exhibits a Pugh's ratio of 0.529 and hardness of 23.9 GPa, it also shows an indirect band gap of 2.056 eV with good absorption in ultraviolet regions. More importantly, the porous 3D-BC2N is found to be the first borocarbonitride with a negative Poisson's ratio of −0.08. Our study expands the borocarbonitride family with new features.

Photocatalytic reduction of hexavalent chromium (Cr (VI)) has received widespread attention due to its high toxicity, in which the interfacial electrons generation and transfer on the conduction of the semiconductor surface was the key factor. Herein, Polydopamine (PDA) as hole scavengers and eco-benign polymer, was modified on the TiO2 surface which can not only enhance the hole-electron separation and then generate more long-lived electrons for Cr (VI) reduction but also harvest visible light. Different coated thickness of TiO2/PDA has systematically been investigated for the effect on the electrons generation and reduction treatment ability of Cr (VI), the results showed that TiO2/PDA-15 exhibited the more localized electron, making it advantageous for Cr (VI) removal. The reduction kinetics of Cr (VI) by electrons exhibited two distinct phases: an initial fast reduction and then slow decay removal due to the deposition of Cr (OH)3 solids on the synthesized TiO2 surface in neutral or alkali conditions. While, in the acidic solution, fast removal of Cr (VI) was obtained only within 3 min. A wastewater treatment and a preliminary in vivo study on Daphnia magna experiment suggested that treatment with the TiO2/PDA-15 can effectively remove Cr (VI) and significantly reduce its lethality.

Le confinement généralisé de la population urbaine de Wuhan au début de 2020 en vue de contenir l’épidémie de Covid-19 a soulevé de nombreux problèmes liés au quotidien des habitants, comme l’alimentation. Le sondage à distance de 155 Wuhanais complété par des entretiens avec des acteurs de la vie locale aide à comprendre comment ces situations ont été vécues et partagées à l’intérieur des communautés résidentielles et à l’échelle des quartiers. À travers la question de l’approvisionnement alimentaire, l’enquête éclaire le rôle des comités de résidants et souligne l’apport des réseaux socionumériques dans la mise en œuvre d’une gestion de proximité, matrice collective des villes chinoises contemporaines. The lockdown of the Wuhanese population in early 2020 to contain the spread of the Covid-19 epidemic raised many challenges. Among others, maintaining a continuity of daily life activities such as food supply was a key concern for the public administration. The remote survey of 155 Wuhanese, supplemented by interviews with local actors, sheds light on how these situations were experienced and shared among residential communities. Through the issue of food supply, this survey highlights the role of the residents' committees and underlines the contribution of digital social networks to neighborhood-level management, both being core characteristics of the contemporary Chinese cities.

Many environmental chemicals have been found to exert estrogenic effects in cells and experimental animals by activating nuclear receptors such as estrogen receptors and estrogen-related receptors. These compounds include bisphenols, pesticides, polybrominated diphenyl ethers (PBDEs), organophosphate flame retardants, phthalates and metalloestrogens. G protein-coupled estrogen receptor (GPER) exists widely in numerous cells/tissues of human and other vertebrates. A number of studies have demonstrated that GPER plays a vital role in mediating the estrogenic effects of environmental pollutants. Even at very low concentrations, these chemicals may activate GPER pathways, thus affect many aspects of cellular functions including proliferation, metastasis and apoptosis, resulting in cancer progression, cardiovascular disorders, and reproductive dysfunction. This review summarized the environmental occurrence and human exposure levels of these pollutants, and integrated current experimental evidence toward revealing the underlying mechanisms of pollutant-induced cellular dysfunction via GPER. The GPER mediated rapid non-genomic actions play an important role in the process leading to the adverse effects observed in experimental animals and even in human beings.

Motivated by the recent progress in synthesizing graphene by using aromatic benzene molecules as precursors, herein, we propose a new two-dimensional (2D) carbon allotrope by using nonaromatic molecule cyclooctatetraene as the precursor from a bottom-up approach. In this structure, all the carbon atoms are threefold coordinated, similar to the sp2-hybridized atoms in graphene; thus, we name the poly-cyclooctatetraene framework as PCF-graphene. First-principles calculations reveal that although PCF-graphene is metastable compared with graphene, it is thermally, mechanically, and dynamically stable. Different from graphene with a single-atomic thickness and zero band gap, PCF-graphene has a finite thickness of 2.45 A and is a semiconductor with a direct band gap of 0.77 eV. It exhibits anisotropies in mechanical properties, carrier mobility, and optical adsorption because of its anisotropic lattice. This study not only sheds insights into the design of 2D carbon materials from some simple organic molecules ...

It is of great importance to explore new materials beyond conventional ones for CO2 conversions. Inspired by the edge-state-enhanced conductivity in topological nodal-line semimetals (NLSs) and the...

Motivated by the feasibility of hybridizing C- and BN-units as well as the recent synthesis of a triphenylene-graphdiyne (TpG) monolayer, for the first time we explore the stability and electronic band structure of the Tp-BNyne monolayer composed of C-chains and the BN analog of triphenylene (Tp-BNyne) by using density functional theory. We find that the single layer Tp-BNyne is stable and exhibits a semiconducting character with a direct band gap of 3.78 eV. The band gap of Tp-BNyne can be flexibly tuned in a wide range by applying uniaxial straining in different directions, or by changing the length of the carbon chain, or by stacking in multilayers with different configurations, while the feature of a direct band gap can be well maintained. These intriguing characteristics endow the Tp-BNyne monolayer with additional advantages over the pristine TpG monolayer, which would stimulate more effort on the design and synthesis of novel 2D materials with high stability, tunable porosity, and controllable functionality for nanoelectronic and optoelectronic applications.

Search for novel cathode materials is of current interest. Among them, Li2MnSiO4 shows promise as a cathode material in the poly-anion family due to its structural diversity, abundance, low cost, and high theoretical capacity (330 mA h g−1). However, it suffers from low electronic and ionic conductivity, limited reversible capacity, and poor cycling performance. To overcome these deficiencies, using a global structure search at high pressure, we find a new phase with a group symmetry of Cc, which is the ground-state at a pressure of 50 Gpa, and remains stable when the pressure is released. This new phase exhibits many attractive features such as a high energy density of 612 Wh kg−1 with a reversible capacity of 170 mA h g−1, a high average discharge voltage of 3.6 V, improved electronic conductivity, coexistence of anionic and cationic redox, and superior ionic conductivity due to unique diffusion channels with reduced steric hindrance and coulombic repulsion. All these features endow the new phase of Li2MnSiO4 with potential for use as a high performance cathode material.

Na-ion batteries, as an alternative to Li-ion batteries, have gained increasing attention due to the abundance of sodium and its low cost. In the present work, we prepare a 3D porous carbon material by inserting hexagonal carbon rings into sp3 C–C bonds in a previously established 3D-(4,4) lattice, termed tC24. Ab initio calculations uncover that not only is tC24 thermally, dynamically and mechanically stable, but it also exhibits a unique electronic band structure with two topological nodal surfaces traversing through the whole Brillouin zone. More importantly, tC24 is the first all carbon topological nodal-surface semimetal for Na-ion batteries, exhibiting a high theoretical capacity of 232.65 mA h g−1, a low diffusion energy barrier for Na ions, an appropriate average voltage of 0.54 V and a negligible volume change (∼0.94%) during charging/discharging operation. These properties provide tC24 with a potentially long cycling life when used as an anode material for Na-ion batteries.

Motivated by the advantages of inherent high electronic conductivity and ordered porosity of topological semimetal monoclinic C16 (m-C16), we explore its possible use as a lithium-ion battery anode material. Using state-of-the-art theoretical calculations, we show that the m-C16 structure has a high specific capacity of 558 mA h g−1, a low Li ion diffusion energy barrier of 0.25 eV, and a small volume change of 3.6% during charging/discharging operation. The overall performance of m-C16 is superior to that of topological semimetal body-centered orthorhombic C16 (bco-C16) reported recently with corresponding values of 558 mA h g−1, 0.53 eV and 13.4%. This study further expands the family of porous topological carbon for high-performance anode materials going beyond the commercially used graphite.

The shuttle effect caused by polysufides dissolution and diffusion in electrolyte solutions severely hinders the practical application of Li S batteries. To overcome this problem for achieving long cycle life and high rate performance, anchoring materials are highly desirable. In this work, for the first time, we explore the anchoring behaviors of polysulfides on C3B and C3N monolayers with reference to pristine graphene by using density functional theory computations. The complicated anchoring mechanisms are further explored by analyzing the competition between van der Waals, electrostatic, and chemical interactions. Our results suggest that C3B monolayer shows the best anchoring performance for lithium polysulfides due to the strong chemical interaction induced by charge transfer while C3N monolayer has relative weak anchoring effect due to the electrostatic interaction. Based on the enhanced conductivity, strong anchoring ability, and improved rate capability, C3B monolayer shows the promise as an anchoring material for lithium-sulfur batteries.

Due to the structural failure of layered CoO2, there has been considerable effort to improve the reversible capacity of commercial LiCoO2 cathode materials. Using a global structural search, we have discovered a rutile-like CoO2 phase as the ground state at 50 GPa. The material is thermally, mechanically and dynamically stable, even after removing the pressure. We show that, when lithiated, this LiCoO2 material can serve as an improved cathode material for Li-ion batteries. Its many advantages include good structural stability against transition metal migration and oxygen loss, one-dimensional channels for Li ion diffusion with variable energy barriers (0.36–0.86 eV), enhanced ionic mobility, and good intrinsic electronic conductivity brought about by its metallic band structure. Furthermore, with a voltage platform of 3.2–3.8 V, it provides better stability against conventional carbonate solvents than conventional layered cathode materials (>4.0 V). All these features demonstrate that the non-layered CoO2 phase synthesized at high pressure would be a promising cathode material, providing a performance beyond that of the currently used layered phase.

Hafnium (Hf) has been used as a cathode material for thermionic emission in high temperature environments for a long time. However, the effect of grain boundaries (GBs) on its work function has not been reported. In this work, by using first-principles calculations, we find that the introduction of GBs would reduce the work function of Hf surface as compared with that of the perfect crystal, and by increasing the distance between two grain boundaries, the work function converges gradually to the value of monocrystalline Hf. By analyzing the surface atomic structure and charge density distribution, we find that the reduced work function of GB-containing structures originates from the increase of atomic distance and the changes of atomic coordination environments at the GB region, which results in redistribution of electrons and enhances the electronic density of states at the Fermi level.

Exosomes are a type of nano-scale biofilm-enclosed vesicles involved in intercellular communications, which are actively secreted by almost all eukaryotes and have been suggested to play an important role in various biological and physiological processes. Since exosomes carry biological contents informative of the original cells and can be easily harvested from body fluids, they are regarded as an emerging and promising biomarker bank for liquid biopsy. Conventional exosome detection methods such as transmission electron microscopy, nanoparticle tracking analysis, and Western blotting are cumbersomely conducted with partial information and limited in sensitivity and specificity. Thus new analytical approaches are urgently needed to facilitate exosome-based in vitro early diagnosis of diseases. Herein, we summarized recent advances in the development of immunoassay-based technologies for rapid exosome detection which have sparked huge interest in the last few years. A brief introduction of exosomes and general principles of immunoassays was first presented. We then described in some detail the studies on four major types of immunoassay technologies incorporated with specific configurations for exosome quantification as well as surface protein profiling, including single immunosensors, immunosensor arrays, immunoassays integrated with microfluidics, and paper-based immunoassays. Challenges and future research perspectives were also discussed in the field of exosome immunoassay detection.

Halide materials are of current interest for all-solid-state batteries. In this study, we systematically studied seven fluorides Li 3MF6 (M = Al, Sc, Ti, V, Cr, Ga, In) using density functional theory combined with molecular dynamics simulation and the grand potential phase diagram analysis. Among them, Li3ScF6 is identified to be a promising solid electrolyte for lithium ion batteries with high Li ionic conductivity of 0.28 mS/cm at room temperature, wide electrochemical window of 0.59–6.38 V, and excellent interfacial stability with high-voltage cathodes including LiMn 1.5Ni0.5O4 (4.7 V), LiCoPO4 (4.8 V), and LiNiPO4 (5.1 V). Besides, Li3AlF6 is identified as a potential coating material with high-anodic limit of 6.48 V and good compatibility with cathodes and sulfide-based solid electrolytes. This study expands the family of halide materials for battery applications.

The ferromagnetism in Cr-based monolayers is of current interest (2019 Nat. Nanotechnol. 14 408), however, the Curie temperature is low. How can we enhance the thermal stability of ferromagnetism? Motivated by the recent synthesis of the layered conductive magnet CrCl

Motivated by the novel properties of topological nodal-line semimetal and its compatibility with the well-developed Si-based semiconductor technology, we propose a three-dimensional all-silicon topological nodal-line semimetal composed of interpenetrating silicene networks (ISN). Using state-of-the-art first-principles calculations and the cluster expansion method, we find the ISN structure to be dynamically, thermally, and mechanically stable. In addition, it exhibits linearly dispersive band crossings along two perpendicular high-symmetry directions due to the band inversion and shows two nontrivial nodal lines, traversing in the Brillouin zone near the Fermi level. Furthermore, ISN has the potential as an anode material for sodium-ion batteries with an extremely low diffusion energy barrier and a small volume change during the charging/discharging process, which would lead to a high rate and stable cycling performance.

It has been a great challenge to develop a high-rate anode material with high-capacity, fast Li-ions diffusion and long cycling life going beyond the commercially used graphite in Li-ion battery. Here for the first time we propose a strategy combined high-pressure synthesis method with the global structure search to find a topological semimetal porous carbon as the desired anode. Our crystal-structure searching shows that we can obtain the ground state of an orthorhombic phase $\mathrm{Li}{\mathrm{C}}_{6}$ with regular pores at 30 GPa, and when the Li atoms are removed, the resulting carbon structure is the recently predicted interlocked graphene network (IGN) that is a topological semimetal with an intrinsic high electronic conductivity. Based on the state-of-the-art first-principles calculations, we further find that the Li-ion migration energy barrier in the IGN is extremely low and the estimated diffusion coefficient can reach a magnitude of ${10}^{\ensuremath{-}4}\phantom{\rule{0.16em}{0ex}}\mathrm{c}{\mathrm{m}}^{2}/\mathrm{s}$ at both low and high Li concentrations, which is three orders of magnitude larger than that of graphite anode. Moreover, the volume changes during the Li insertion and deinsertion are smaller than $3.2%$, while the theoretical specific capacity is the same as that of graphite anode. Our studies not only suggest a practical way of synthesizing the topological semimetal carbon but also propose a new anode material for Li-ion battery.

Extensive efforts have been devoted to C-Si compound materials for improving the limited specific capacity of graphite anode and avoiding the huge volume change of Si anode in Li-ion battery, but not much progress has been made during the past decades. Here, for the first time we apply the targeted structure search by using Li in desired quantity as chemical template to regulate the bonding between C and Si, which makes searching more feasible for us to find a new stable phase of C2Si (labelled as T-C2Si) that can better fit the XRD data of silicon dicarbide synthesized before. Different from the conventional semiconducting silicon carbides, T-C2Si is not only metallic with high intrinsic conductivity for electrons transport, but also porous with regularly distributed channels in suitable size for Li ions experiencing a low energy barrier. T-C2Si exhibits a high specific capacity of 515 mA/g, a high average open-circuit voltage of 1.14 eV, and a low volume change of 1.6%. These parameters meet the requirements of an ideal anode material with high performance for electric vehicles. Moreover, our targeted search strategy guarantees the resulting anode material with a desirable specific capacity and a small volume change during charging /discharging, and it can be used to find new geometric configurations for other materials., Comment: Submitted to Journal of Materials Chemistry A at 27-Mar-2018, Manuscript ID is: TA-ART-03-2018-002807

Three metallic three-dimensional (3D) microporous SiC4 crystals are identified for the first time by using an unbiased structure search based on the particle-swarm optimization (PSO) algorithm combined with density functional theory (DFT) calculations, which are found to be thermally, dynamically and mechanically stable. The unusual metallicity of these three microporous SiC4 allotropes stems from the delocalized p electrons along carbon ribbons or chains. Moreover, empowered by the appropriate channel size and metallic feature, SiC4-Ⅰ manifests as a promising anode material for Na-ion batteries with theoretical capacity of 176.3 mAhg−1, diffusion energy barrier of 0.25–0.41 eV for Na ions, appropriate average open circuit voltage of 0.55 V and negligible volume change of 0.57% during charging/discharging process.

Background: The enormous physicochemical and structural diversity of metal oxide nanoparticles (MeONPs) poses significant challenges to the testing of their biological uptake, biodistribution, and effects that can be used to develop understanding of key nano-bio modes of action. This has generated considerable uncertainties in the assessment of their human health and environmental risks and has raised concerns about the adequacy of their regulation. In order to surpass the extremely resource intensive case-by-case testing, intelligent strategies combining testing methods and non-testing predictive modeling should be developed. Methods: The quantitative structure-activity relationship (QSARs) in silico tools can be instrumental in understanding properties that affect the potencies of MeONPs and in predicting toxic responses and thresholds of effects. Results: The present study proposes a predictive nano-QSAR model for predicting the cytotoxicity of MeONPs. The model was applied to test the relationships between 26 physicochemical properties of 51 MeONPs and their cytotoxic effects in Escherichia coli. The two parameters, enthalpy of formation of a gaseous cation (▵Hme+) and polarization force (Z/r), were elucidated to make a significant contribution for the toxic effect of these MeONPs. The study also proposed the mechanisms of toxic potency in E. coli through the model, which indicated that the MeONPs as well as their released metal ions could collectively induce DNA damage and cell apoptosis. Significance: These findings may provide an alternative method for prioritizing current and future MeONPs for potential in vivo testing, virtual prescreening and for designing environmentally benign nanomaterials.