Search

The marriage of traditional gas-sensing semiconductors with low dimensional nanostructures is expected to exhibit interesting properties in the detection of hazardous gases. Herein, novel hollow-spherical heterojunctions are assembled for thin film gas sensors by using p-type black phosphorus (BP) and n-type tin oxide (SnO 2). Green synthesis strategies are employed to prepare BP nanodots and SnO 2 quantum dots. The aerosol-assisted chemical vapor deposition is used to prepare thin films with hollow-spherical heterojunctions. The BP incorporation significantly improves the gas-sensing properties of SnO 2 -based thin films, which demonstrate excellent response and repeatability to H 2 S at room temperature. The BP-SnO 2 heterojunction demonstrates more than twice the response and sensitivity of pristine SnO 2 thin film. Moreover, the recovery ability is significantly improved and LOD is decreased to 50 ppb. The hollow-spherical heterojunction has a joint gas-sensing mechanism contributed by both of SnO 2 and BP. The SnO 2 provides fundamental receptor function for gas detection while incorporated BP facilitates the adsorption of target H 2 S and provides additional electrons through the p-n junction tunnel. In addition, a slight negative dependence on humidity is observed for the gas sensor. It is ascribed to the competitive adsorption of water molecules on the BP-SnO 2 heterojunction surface against H 2 S molecules and chemisorbed oxygen. This work not only proposes novel heterojunction nanostructures for room-temperature gas detection, but also contributes to the functional integration of traditional gas-sensitive materials and emerging 2D materials in sensor technology. [ABSTRACT FROM AUTHOR]

Recycling treatment of wastewater containing hexavalent chromium [Cr (VI)] has always been an important environmental issue. In this paper, taking advantage of the natural affinity of CrO 4 2− and lead ions, lead carbonate was selected as a precipitant to recover Cr (VI) in the form of chrome yellow (PbCrO 4). Firstly, the variation of Cr (VI) and lead species in K+-CrO 4 2−-Pb2+-CO 3 2− solution system with pH and PbCO 3 dosage was calculated by Visual MINTEQ. The results show that the treatment effect is better under acidic conditions. Then, the effects of parameters on the removal rate of Cr, including the initial pH of solution, reaction time, reaction temperature, and the dosage of lead carbonate, were studied by batch experiments. Results show that the initial pH of solution, reaction time, and the dosage of lead carbonate have great influence, whereas reaction temperature has slight influence. And the concentration of Cr (VI) could be reduced from 100 mg/L to 0.043 mg/L at an initial pH of 3, a reaction time of 45 min, and the dosage of lead carbonate as n(PbCO 3)/n(K 2 CrO 4) = 2. The precipitates are analyzed by XRD, SEM, and EDS，and the results are consistent with the predictions of Visual MINTEQ, that is, the newly produced substance is only PbCrO 4. The reaction mechanism of Cr (VI) on the surface of lead carbonate was studied by the adsorption kinetic model, and the results showed that the reaction was more fit with the pseudo-second-order kinetic model. Density functional theory (DFT) calculations show that CrO 4 2− could effectively react with lead atoms with unsaturated coordination bonds on the surface of lead carbonate and free lead ions leached from the surface of lead carbonate to form lead chromate. Under acidic conditions, the removal of Cr (VI) by PbCO 3 may involve two main mechanisms: the mineralization and precipitation of lead and chromate ions dissolved from the surface of cerussite and the chemical adsorption of chromate ions on the surface of cerussite. This study provides a new and efficient strategy for the resource treatment of Cr (VI)-containing wastewater. [ABSTRACT FROM AUTHOR]

Link prediction is an important problem in dynamic systems, where the goal is to predict future unweighted or weighted link topologies using historical context. Compared with unweighted links, weighted links can preferably reveal the nature and strength of the interactions among entities. However, weighted links also bring greater challenges because they require subtle structural adjustments and numerical variations to be captured. Existing methods are primarily tailored for unweighted links and most generally suffer from low-quality performance when applied to Weighted Link Prediction (WLP) task. In this study, we propose a novel generative framework that adopts conditional Invertible Neural Networks (INNs) to achieve WLP. The proposed framework leverages the benefits of conditional INNs to exactly optimize the log-likelihood in the latent space conditioned on the historical context, which can be sensitive to minor replacements in real-world systems and derive accurate WLPs. Furthermore, to deal with the long-tail statistical phenomenon of edge weights observed in real life, a tail-adaptive distribution is learned in latent space to capture the tail properties and enhance the model's ability. To verify the effectiveness of the proposed method, we conduct extensive experiments on four datasets from different systems. The experimental results demonstrate that our model achieves impressive results compared to state-of-the-art competitors. • We propose a novel framework called CInvNet for weighted link prediction. • We propose to push a tractable density with known tails in latent space. • Experiments demonstrate the consistently superior performance of CInvNet. [ABSTRACT FROM AUTHOR]

• The GTN model is modified by considering the damage behaviors under reverse loading. • The microscopic damage evolutions are modified by two kinds of exponential function. • The preloading and loading sequence can affect the damage accumulation and fracture. • The predictive ability of ductile fracture under reverse loading is highly improved. Void nucleation, growth, deformation and coalescence are the main microscopic damage mechanisms for plastic deformation of sheet metals. To describe the effect of reverse loading on the microscopic damage accumulation and ductile fracture, the damage evolution equations in regard of void nucleation, void growth, shear void nucleation and shear deformation damage were modified. Through the further introduction of the combined hardening model, an extended Gurson-Tvergaard-Needleman (GTN) model was constructed in this study, to improve the predictive ability of ductile fracture under reverse loading conditions. Two typical reverse loading experiments including compression-tension and shear-reverse shear were performed. The number, size and shape of microscopic voids were qualitatively analyzed and compared through the microscopic observations, it is indicated that the preloading and loading sequence strongly affect the damage accumulation and the final ductile fracture, which is the microscopic damage mechanisms under reverse loading. The proposed GTN model was verified by the load responses and displacements at fracture (DAFs) of the conducted reverse loading experiments. The good agreement between numerical simulations and experimental results proves the rationality of the proposed GTN model and its accuracy to the prediction of ductile fracture under reverse loading conditions. [Display omitted] [ABSTRACT FROM AUTHOR]

• This retrospective cohort of 545 patients demonstrated better rwPFS than previously reported. • Patients with high PD-L1 expression, early TNM stage and EGFR -negative were recommended for immunotherapy. • Clinicians choose different treatment modalities for patients with different PD-L1 expression. • PD-L1, EGFR mutations, and previous radiotherapy all have a certain impact on the prediction of ICI response in NSCLC. The efficacy and prognosis of immune checkpoint inhibitors (ICIs) remain unresolved issues. Here, we assessed the treatment characteristics and efficacy of ICIs in non-small cell lung cancer (NSCLC) using real-world data and evaluated the predictive value of factors, including programmed death-ligand 1 (PD-L1) expression, for the clinical outcome of ICIs in NSCLC. Analyzed data was collected from hospitalized patients in the West China Hospital of Sichuan University between January 2017 and March 2023. The Kaplan-Meier method was utilized for analyzing real-world progression-free survival (rwPFS), while Cox regression models was employed to access the correlation between the efficacy of immunotherapy and sociodemographic characteristics, disease information, and characteristics of ICI treatment. A total of 545 patients were included in the retrospective study and characteristics of immunotherapy varied significantly among PD-L1 expression groups. The median rwPFS for the entire population was 9.76 months. Subgroup analyses revealed that patients with high PD-L1 expression, early TNM stage, first-line immunotherapy, EGFR wild-type and those who have not received radiotherapy and targeted therapy previously were more likely to have better rwPFS. Furthermore, multivariate Cox regression analyses identified PD-L1 expression, EGFR mutation status and previous radiotherapy as the most influential predictors of the response to ICI treatment. This study presents the real-world experience of Chinese NSCLC patients undergoing ICI treatment, offering guidance for clinical decision-making based on various patient conditions, preferences, and indications for ICIs, through the evaluation of immunotherapy efficacy and predictors in NSCLC patients. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel tetracyclic aromatic lactam unit was firstly developed and used as π bridge for isomeric small-molecule donors. • Tetracyclic aromatic lactam-substituted tin-free donors (o Ph2F, p Ph2F) exhibited a broad bandgap and stong crystallinity. • o Ph2F/ p Ph2F could regulate the crystallization kinetics and vertical phase separation of host system PM6:Y6. • Ternary devices PM6: p Ph2F:Y6 achieved champion PCE of 18.4% with a synergistically improved all photovoltaic parameters. Organic solar cells (OSCs) are rapidly developed for next-generation photovoltaic technologies due to low-cost and solution-processability etc. However, so far high-efficiency organic photovoltaic materials are typically prepared by multi-step Stille reactions, which are neither cost-efficient nor atom-economic, even raise safety concerns and incompatible with large-scale process. Large-scale industrial production of photovoltaic materials through simple, cost-effective, and green chemistry remains to be addressed. In this work, we present a case where two isomeric small-molecule donors based on polycyclic aromatic lactams (PAL) unit, named o Ph2F and p Ph2F with wide-bandgap and high-crystallinity, were designed and synthesized by atom-economic direct C-H activation strategy, modulates pre-aggregation and crystallization kinetics of host system PM6:Y6, induce distinct morphology evolution and effectively boost photovoltaic performance. The best power conversion efficiency (PCE) of 18.40 % for p Ph2F-based ternary devices are found to be a fruit of improved light-harvesting ability, favorable vertical phase separation with enhanced crystallinity, the separated crystallization process of host materials and the higher and more balanced charge transport. To our knowledge, this study achieved the highest PCE among PM6:Y6-based ternary OSCs containing tin-free small-molecule donor, which not only highlights the great potential of PAL-based photovoltaic materials, but also promotes the integration of renewable energy with green chemistry. [ABSTRACT FROM AUTHOR]

• The UV–vis absorption peak intensity of Eu2+ and Ce3+ single/co-doped phosphors increases with their concentrations. • The phenomenon of concentration quenching in dipole-dipole interactions suggests that increasing rare earth ion concentrations may reduce luminescence. • The energy transfer from Ce3+ ions to Eu2+ ions was discussed. Eu2+ and Ce3+ ions with different concentrations of single/co-doped Sr 2 SiO 4 phosphors have been successfully prepared using a high-temperature solid-state reaction. The influences of Eu2+ and Ce3+ ions on the construction and optical performance behavior of Sr 2 SiO 4 have been investigated by X-ray diffraction (XRD), Fourier Transform Infrared Spectrometer (FTIR), scanning electron microscope (SEM), ultra-violet-visible (UV–vis), and photoluminescence (PL) spectral analyses. XRD results revealed that the doping ions have entered the host lattice, and SEM showed the crystallite sizes have been found to vary from 1 to 6 μm. The intensity of the absorption spectra for the co-doped samples was larger than that of the single-doped sample. PL spectra displayed that the emission intensity of the samples strengthened as the amount of concentrations of Eu2+ and Ce3+ ions. The concentration quenching of single/co-doped phosphors was related to dipole-dipole interaction, and the energy from the 2F 5/2 transition to the 5D level of Ce3+ was effectively transferred to the 4f65d level of Eu2+. The Eu2+ and Ce3+ ions co-doping samples resulted in a light green color. The findings from the study reveal that the Eu2+ and Ce3+ ions single/co-doped Sr 2 SiO 4 phosphors would be potential candidates for the LED application. [ABSTRACT FROM AUTHOR]

Triacylglycerols (TGs) are important components of human diet. The positional distribution of fatty acids (FAs) on the glycerol backbone affects the chemistry and physical properties of fats. Especially for infants, the structure of TGs plays an important role in the growth and development. However, limited by detecting technology, accurately identifying regioisomers of ABA/AAB and BAC/ABC/ACB type TGs is a significant challenge for human milk utilization and the development of infant formula. For this, we exploit a novel method for identifying the regioisomers of ABA/AAB and BAC/ABC/ACB type TGs within complex lipid mixtures, via used electron activated dissociation (EAD) tandem mass spectrometry. The distribution information of acyl chains at the sn -2 and sn -1/3 positions of glycerol backbone and double bonds in unsaturated FAs can be easily obtained by fragmenting TG ions with energetic electrons (15 eV). Then, the standard curve was established by correlating the peak area intensity of sn -2 characteristic product ion with the content of TG regioisomers standard. These analytical methods successfully enabled the identification and quantification of TG regioisomers in human milk, cow milk, infant formula, palm oil, and sunflower oil. Additionally, the distribution of the double-bond positions of unsaturated FAs in these samples was also identified. Compared to traditional methods, this approach eliminates the need for complex processing and analysis procedures, enabling rapid structural characterization of ABA/AAB and BAC/ABC/ACB type TGs within 17 min. Hence, we provide a rapid and convenient methodology for detecting and analyzing ABA/AAB and BAC/ABC/ACB type TG regioisomers, thereby offering valuable assistance in the development of specialized formulations and facilitating effective process control for ensuring the quality of edible oils and fats. [Display omitted] • AAB and ABC type triacylglycerol (TG) regioisomers were analyzed using electron activated dissociation (EAD) tandem mass spectrometry. • This method only requires one standard to quantify the corresponding TG regioisomers in complex oils. • Synthesis of TG regioisomers using randomization reactions expands the capabilities of EAD for TG regioisomers identification. • The double bond positions of unsaturated FA in TGs were determined using the EAD method. [ABSTRACT FROM AUTHOR]

In this paper, Sr 2 SiO 4 phosphors with different Sm3+ concentrations and Sr 2 SiO 4 :0.006Sm3+ phosphors obtained from the coal gasification slag as raw materials have been synthesized by the high-temperature solid-phase method. The influence of Sm3+ ions and the purity of SiO 2 on the structural and optical attributes of Sr 2 SiO 4 have been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible (UV–Vis) spectrum, photoluminescence (PL) spectra and fluorescence lifetime analysis. XRD results showed that the doping ions have entered into the host lattice, and SEM shown the crystallite sizes have been found to vary from 1 to 3 μm. PL spectra displayed that the emission intensity of the samples increased with the increase in concentrations of Sm3+ ions. At the optimum doping concentration, the luminous intensity and fluorescence lifetime of the sample prepared by the purified silica is much higher than that of the phosphor prepared by the chemical product silica, which is close to that of the pure chemical reagent. Finally, we explored the application of fluorescent powder in pc-WLED devices. Notably, the devices exhibited excellent luminous performance at 20 mA current. The results demonstrate that coal gasification slag (CGS) product can be used to synthesize brilliant materials with potential uses for the pc-WLED technology. • The high fluorescence intensity Sm3+ doped Sr 2 SiO 4 phosphors were prepared using silica extracted from coal gasification slag as raw materials. • Effect of raw material purity was investigated from the excitation and emission spectra analysis. • The luminescence performance of Sr 2 SiO 4 phosphor is found to be strongly dependent on rare earth ions. [ABSTRACT FROM AUTHOR]

The splash erosion-induced soil aggregate turnover is important to understand the mechanisms of soil degradation and soil organic carbon (SOC) cycling. However, the relationship between aggregate turnover and rainfall impact has not been explored directly because of methodological difficulties. The soil samples, developed from Quaternary red clay, were adopted from three land use types: natural forest (NF), garden/shrubs (AS), and abandoned meadow (AM). By using rare earth oxides to trace the transformation in soil aggregates of four size-fractions (>2 mm, large macroaggregate; 0.25–2 mm, small macroaggregate; 0.053–0.25 mm, microaggregate; <0.053 mm, silt and clay fraction), we investigated aggregate turnover based on splash experiments at four different rainfall kinetic energies (501.95, 326.00, 252.50 and 153.39 J·m−2·h−1). After splash erosion, the rare earth oxides concentrations and SOC content in different soil aggregate fractions were measured. Our results indicated that the soil aggregates mainly followed the direction of breakdown, with higher cumulative breakdown rates than formation rates. Specifically, with the rainfall kinetic energy increased to 501.95 J·m−2·h−1, the three soil samples (NF, AS, AM) exhibited the highest breakdown rates of 48.35%, 31.95% and 39.29% in large macroaggregates, respectively. Meanwhile, the formation pathway was mainly in the direction of forming small macroaggregates. Compared to soil aggregate from NF, AS and AM aggregates had higher proportion of silt and clay fraction transformed into larger aggregates. Moreover, the changes of SOC varied in aggregates during splash process. With the increase of rainfall kinetic energy, the organic matter content gradually decreased in large aggregates and microaggregates in AM and AS (P < 0.05), in contrast to a trend of first increasing and then decreasing (P < 0.05) in their small aggregates. In the clay particles, with the increase of rainfall kinetic energy, the SOC content gradually decreased in NF (P < 0.05) and fluctuated in AS, with both their organic matter content lower than before the splash test (P < 0.05). The loss of SOC in total soil was linearly related to the net breakdown rate of soil aggregates (P < 0.05, R2 =0.635). Therefore, we proposed a framework to highlight the quantitative relationship between aggregate turnover and SOC degradation under splash, which may enrich the mechanisms of soil erosion and soil degradation in the positions where erosion takes place. • Aggregate turnover is significantly accelerated by splash erosion. • Aggregate turnover rate depends on aggregate size and rainfall kinetic energy. • Soil carbon dynamics within aggregates are tightly related to aggregate breakdown. [ABSTRACT FROM AUTHOR]

• DDTC for binding with Co2+ and Ni2+ was analyzed by DFT calculation. • DDTC can removal 97.98% cobalt and 98.08% nickel from their low-grade solution. • DDTC can removal nano-sized sulfide particle from solution. The effectiveness and mechanism of dimethyldithiocarbamate (DDTC) for recovering low-grade cobalt and nickel from the lixivium of a manganese-rich slag have been investigated via a computational and experimental study. First principles calculations using a solvation model showed that DDTC can efficiently bind Fe(III), Co(II), Ni(II), and Cu(II) via the carbon disulfide functional group, indicating that Fe(III) and Cu(II) should be removed before addition of DDTC. Experimentally, 80.2% Co and 78.0% Ni were extracted from the slag containing low-grade 0.09% Co and 0.073% Ni under optimal conditions. Then, 99.92% of iron was removed from the lixivium via hydroxide precipitation. Finally, after the treatment with DDTC, excellent recoveries of 97.98% and 98.08% were obtained for Co and Ni, respectively. Further, high-resolution X-ray photoelectron spectroscopy results showed that the added DDTC can collect not only the free metal ions but also the nano-sized sulfide mineral particles. Thus, DDTC shows potential for the recycling of low-grade Co and Ni resources from solution. [ABSTRACT FROM AUTHOR]

This study compared the experimental and theoretically calculated differential absorbance spectra (DAS) of quercetin, which is a typical model compound of natural organic matter (NOM) that is found in biochemical and environmental systems. Absorbance spectra of quercetin, which has five exchangeable protons, were generated at each state of deprotonation and its binding with Cu(II) ions. The spectra showed that the emergence of characteristic peaks in the experimental DAS was associated with the deprotonation of quercetin and its binding with Cu(II). Calculations of the theoretical DAS were conducted based on the time-dependent density functional theory (TD-DFT) methods and yielded results that were consistent with the experimental DAS data because the features in the absorbance spectra were primarily associated with the electron transitions from the highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO) in the molecule. The appearance of the characteristic peaks in the DAS reflects the changes of the structure and electron distribution of the organic molecules that are induced by water treatment or environmental processes. Unlabelled Image • Differential absorbance spectra (DAS) can track the deprotonation of quercetin. • DAS can track the complexation of quercetin and Cu ion. • Experimental and theoretical DAS are consistent in most case. • The features in DAS are induced by electron transition from HOMO to LUMO. • Peaks in DAS reflect the change of molecular orbital around reactive sites. [ABSTRACT FROM AUTHOR]

• A novel strategy was used for preparation of flame retardant diatomite with DDP based on esterification method. • The silicone rubber composites fabricated using this flame retardant exhibited reduced fire risk and toxicity behaviors. • The inexpensive property of modified diatomite could also expand its fire safe applications. A novel strategy was used for preparation of flame retardant based on biomass debris to improve the flame retardant property of silicone rubber (SR). [(6-oxido-6H-dibenz[ c , e ][1,2]oxaphosphorin-6-yl)methyl]butanedioic acid (DDP) was used to modify diatomite by esterification method, and DDP@diatomite was obtained. The structure and morphology of this novel additive was identified using Fourier transform infrared spectroscopy (FTIR), Brunner-Emmet-Teller (BET) measurements, and X-ray photoelectron spectroscopy (XPS) together with scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDXS) techniques. Thermogravimetric (TG) analysis was performed to evaluate the thermal degradation behaviors of diatomite and DDP@diatomite. This novel additive was applied into silicone rubber (SR) composites. Combustion parameters, including heat release rate (HRR), total heat release (THR), smoke production rate (SPR), carbon monoxide (CO), peak smoke production rate (PSPR), peak carbon monoxide (PCO) and vertical burning time, were characterized by cone calorimeter and vertical burning tests. Results indicated that this flame retardant can reduce fire risk and toxicity effectively. TG and X-ray diffraction (XRD) patterns of SR and its composites were also investigated. The inexpensive property of modified diatomite could also expand its fire safe applications. [ABSTRACT FROM AUTHOR]

• Gaussian bands in DAS reveal protonation-active functionalities in NOM. • DAS and FT-ICR-MS identify protonation-active molecules in NOM. • Genetic molecular network analysis identifies active chromophores in NOM molecules. • Molecular orbital theory interprets electronic transitions of active chromophores. Natural organic matter (NOM) is critical for the biogeochemical cycles of energy and many elements in terrestrial and aquatic ecosystems, and protonation-active functional groups in NOM molecules, notably carboxylic and phenolic groups often mediate these critical environmental functions. Molecular heterogeneity, polydispersity and dynamic behavior of NOM complicate achieving an unambiguous description of its molecular properties and reactivity. This study demonstrates that differential ultraviolet-visible (UV/VIS) absorbance spectra (DAS) of NOM acquired at varying pH values exhibit several distinct features associated with the deprotonation of NOM molecules, independent of the environmental provenance of NOM (e.g., surface water, seawater, sediment, and wastewater). The protonation-active functionalities that contribute to the Gaussian distribution bands present in the DAS were identified here by comparing characteristic properties of the bands with the stoichiometries of NOM molecules ascertained by Ultrahigh-Resolution Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS). The protonation-active individual chromophores universally present in NOM molecules were identified by a genetic molecular network analysis. The observed DAS features were closely modeled via superimposing DAS spectra of 51 individual protonation-active chromophores. Molecular orbital theory was applied to further interpret the deprotonation of these chromophores, their molecular structure, electron distribution, and electron transitions measured using DAS. The high sensitivity and easy implementation of the DAS approach allows using it as a powerful tool to quantify the molecular properties and reactivity of NOM at environmental concentrations. [Display omitted] [ABSTRACT FROM AUTHOR]

Conductive hydrogels (CHs) are characterized by tissue-like mechanical properties, multiple stimuli-responsive abilities and favourable biocompatibility, enabling their wearable devices to construct a conformal interface with rugged tissue surfaces compatible with human body for real-time monitoring. However, external power supply requirements and complex fabrication processes limit their broad applications. Self-powered wearable devices can harvest energy from humans and the ambient environments, benefitting a long-term operating ecosystem. In this review, we discuss the materials engineering and designs for CHs-based devices for bioenergy harvesting and self-powered application. Specifically, we highlight the unique advantages of CHs in bioelectrical interfacing with the human body. CHs-based flexible bioenergy harvesters as well as self-powered applications are then summarized. Finally, we will provide the current challenges for materials, device designs and feasible approaches in the next-generation CHs-based multifunctional devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Based on native guanine, a group of G-analogues are obtained by fluorophore replacement and ring extension. • The efficient fluorescence is quenched when xG paired with the complementary adduct O4-meT. • The fluorescence quenching is attributed to intermolecular charge transfer character. DNA alkylation is caused by long-term exposure of cells to the environmental and endogenous alkylating agents, which can also lead to DNA mutations and therefore trigger some cancers. Since O4-methylthymidine (O4-meT), mismatched with guanine (G), is the most common but not easily repaired alkylated nucleoside, monitoring O4-meT can help to effectively reduce the occurrence of carcinogenesis. In this work, the modified G-analogues are selected as the fluorescence probe to monitor the existence of O4-meT according to its pairing characteristics. The photo-physical properties of considered G-analogues formed by ring expansion or addition of fluorophores were studied in detail. It is found that, compared with natural G, the absorption peaks of these fluorescence analogues are red-shifted (>55 nm) and the luminescence is enhanced by π-conjugation. Especially, the xG has a large Stokes shift (65 nm) with fluorescence insensitive to natural cytosine (C) and retains efficient emission after pairing, while it is sensitive to O4-meT and the quenching phenomenon occurs due to the excited state intermolecular charge transfer. Accordingly, the xG can be used as a fluorescent probe to identify the O4-meT in solution. In addition, the direct use of deoxyguanine fluorescent analogue for monitoring O4-meT was evaluated by the effects of ligating deoxyribose on absorption and fluorescence emission. [ABSTRACT FROM AUTHOR]

Graphical abstract A novel sacrificial template strategy has been developed to fabricate alloyed Zn x Cd 1-x S double-shell hollow nanospheres. When evaluated for their photocatalytic properties, the as-prepared alloyed Zn 0.46 Cd 0.54 S double-shell hollow nanospheres exhibit the excellent hydrogen production under visible-light illumination. Highlights • Alloyed Zn x Cd 1-x S double-shell hollow nanospheres have been prepared on the large scale via a sacrificial template route. • The synthetic mechanism of the Zn x Cd 1-x S double-shell hollow nanospheres has been extensively studied. • The alloyed Zn 0.46 Cd 0.54 S double-shell hollow nanospheres exhibit the excellent hydrogen production. Abstract Hollow nanostructures are of great scientific and technological importance for extensive applications in photocatalysis, drug delivery, wastewater treatment, etc. In this study, we have developed a facile hydrothermal method for the large scale fabrication of alloyed Zn x Cd 1-x S double-shell (DS-Zn x Cd 1-x S) hollow nanospheres using hierarchically porous ZnS nanospheres as sacrificial templates and the reagent Cd(Ac) 2 as a Cd source. The growth mechanism of double-shell hollow nanospheres has been studied and illustrated by investigating the morphological evolution of the inter-mediated products. Moreover, the chemical composition and void space between the double-shells of the as-obtained alloyed Zn x Cd 1-x S hollow nanospheres can be regulated by adding a certain amount of Cd(Ac) 2. The optical properties and band structures have been investigated using UV–vis diffuse reflectance spectroscopy (DRS), Mott-Schottky analysis and valence-band (VB) X-ray photoelectron spectroscopy, respectively. When evaluated for their photocatalytic properties, the as-prepared alloyed Zn 0.46 Cd 0.54 S double-shell (DS-Zn 0.46 Cd 0.54 S) hollow nanospheres exhibit excellent hydrogen production, and a H 2 evolution speed of up to 4.11 mol h−1 g−1 is reached under irradiation of visible light (λ > 420 nm). [ABSTRACT FROM AUTHOR]

Metal ions are widely used as activators in the flotation of oxidised minerals. At the same dosage of collector, the recovery of target minerals (cassiterite, scheelite, wolframite and ilmenite) can be evidently improved with the addition of metal ion activator. Adsorption of metal ions and their hydroxides can provide attractive sites for collector attachment, contrary to bare minerals that exhibit considerably low affinity towards the collector. Iron complexes of benzohydroxamic acid (BHA) are formed during the reaction of ferric chloride with BHA in the solution. These complexes also exhibit strong collecting ability towards cassiterite in the flotation, which contradicted the classical theory that the activator must be added before the collector. However, the major active component and the underlying adsorption mechanism of the Fe-BHA complexes are still unknown. In this study, the solution chemistry calculation has been used to identify the major active components of the Fe-BHA complexes. Accordingly, a preferred adsorption model of the Fe-BHA complexes onto the cassiterite surface has been proposed and proven effective, through first-principles calculations based on density functional theory, flotation experiments and adsorption tests. Our results might shed new light on the activation mechanism of metal ions in mineral flotation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ionic liquid (IL) was added in the coagulation bath to replace metal salts for wet-spinning. • As-spun PEDOT: PSS/IL fibers reveal an optimal conductivity (118.3 S·cm−1). • FSC based on PEDOT: PSS/IL fibers reveal an excellent capacitance cycle stability. • PEDOT: PSS/IL fibers have superb sensing capability in wearable sensor. Wet-spinning technology plays an essential role in the development of wearable electronics. Poly(3,4-ethylene dioxythiophene): poly(styrene sulfonate) (PEDOT: PSS) fibers have been widely investigated in this field due to their advantages of being environment-friendly and low-cost. They are mainly wet-spun from a coagulation bath containing ethanol and water with additional metal salts. However, the conductivity of PEDOT: PSS fibers spun by this method is low. Here, we propose a novel coagulation bath made of ionic liquid (IL), ethanol, and water, and the resultant PEDOT: PSS fibers could achieve a conductivity of 118.3 S·cm−1. Furthermore, the fiber-shaped supercapacitor prepared by such PEDOT: PSS/IL fibers reveals an optimal capacitance retention rate of 97 % even after 10,000 cycles, and the capacitance loss of the supercapacitor is only 7 % at −20 ℃. The sensor derived from the PEDOT: PSS/IL fibers has superb sensing capability, indicating their promising applications for wearable electronics. [ABSTRACT FROM AUTHOR]

Using microflotation experiments, this study investigated the effect of Pb 2+ ions on flotation performance of cassiterite (SnO 2 ) by using benzohydroxamic acid (BHA) as collector. Flotation results showed that floatability of cassiterite significantly improved after addition of Pb 2+ ion to the process. Adsorption behaviour and mechanism of BHA on the inactivated and Pb-activated cassiterite surface were further explored by adsorption experiments, zeta potential measurements, X-ray photoelectron spectroscopy analysis and first-principle density functional theory calculations. Experimental and computational results consistently suggested that the adsorbed Pb atoms can coordinate with two O atoms of the two hydroxyl groups on the cassiterite surface. BHA molecules can form two coordination bonds with one Pb ion adsorbed on the cassiterite surface, resulting in a five-membered chelating ring. The proposed adsorption mechanism can be extended to the vast majority of interface assembly systems. [ABSTRACT FROM AUTHOR]

The double peroskite Lu 2 NiMnO 6 was synthesized by a facile hydrothermal method. X-ray power diffraction (XRD) analysis shows it adopts monoclinic structure with space group P2 1 /n , indicating an ordered arrangement at B sites. Valence states analysis done by XPS shows Ni 2+ /Mn 4+ configuration. Raman spectrum reveals an ordered structure in the sample, in agreement with the XRD results. The degree of ordering was greatly enhanced after the sample was annealed at 873 K. Magnetism of the as-grown and annealed samples was analyzed using DC and AC magnetization, as well as Magnetization-Hysteresis. Dielectric anomaly independent on frequency was observed close to the magnetic ordering temperature, indicating the possibility of ferroelectricity and further magnetoelectric coupling. [ABSTRACT FROM AUTHOR]

The purpose of this work was to study the effect of dendrimer modified clay minerals on the structure and properties of ethylene-propylene-diene monomer (EPDM) nanocomposites. Flame-retardant and dendrimer modified organic montmorillonite (FR-DOMt) was successfully prepared by Na + -montmorillonite, tetrahydroxymethyl phosphonium chloride (THPC), N, N-dihydroxyl-3-aminomethyl propionate, and boric acid. This dendritic type of organoclay (OC) was used in preparation of EPDM/FR-DOMt nanocomposites. The properties of these nanocomposites were studied. The dispersion status of the layered silicates in EPDM was revealed by X-ray diffractometer (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). XRD and TEM results showed that FR-DOMt was exfoliated in the EPDM matrix when 10 phr of FR-DOMt was incorporated. The mechanical behavior, thermal stability, and flame retardance of the samples were examined. The experimental data demonstrated that the EPDM hybrids owned an improved tensile strength and elongation at break. In addition, the nanocomposites exhibited higher thermal stability and flame retardance than that of unfilled EPDM matrix. [ABSTRACT FROM AUTHOR]

This strategy uses HfO 2 NPs as a radiosensitizer to cause severe damage, while ATRi can block DNA repair, complementing the efficacy of local radiotherapy. In addition, it can effectively trigger systemic antitumor immune response by driving immune cell infiltration and enhancing immunogenicity based on the cGAS/STING pathway. [Display omitted] • Ultra-small HfO 2 nanoparticles-loaded ATR inhibitor (ATRi) are designed. • HfO 2 nanoparticles enhance DNA damage induced by radiotherapy. • ATRi inhibits the repair of DNA damage and enhances local tumor radiosensitivity. • Our design activates the cGAS/STING pathway and triggers systemic anti-tumor immunity. Nanomaterials as radioenhancer have been widely studied, which exhibits huge advantages in tumor radiotherapy. However, DNA damage repair in tumor cells leads to radioresistance and radiotherapy alone is difficult to effectively suppress metastatic tumor. Herein, a potential strategy is proposed to enhance the local radiotherapeutic effects and trigger systemic antitumor immunity by combining nano-radioenhancer with Ataxia-telangiectasia mutated and RAD3-related (ATR) kinase inhibitor (ATRi). In the design, the nano-radioenhancer can trigger severe damages to tumor cells, while ATRi prevents DNA repair, which markedly complementing the local radiotherapeutic efficacy. In addition, the strategy can efficiently trigger systemic antitumor immune response via driving immune cell infiltration and enhancing immunogenicity based on the cGAS-STING pathway. This study provides a new avenue for nanoparticles-mediated radiotherapy to trigger strong antitumor effect in both local and distant tumor sites. [ABSTRACT FROM AUTHOR]

In recent years, lanthanide doped materials have been extensively studied in the field of fluorescence temperature sensing due to their abundant emission levels and sensitive thermal response. Temperature sensing based on fluorescence intensity ratio (FIR) of upconversion nanoparticles has the advantages of fast temperature response, non-aggressiveness, and high spatial resolution. However, the most reported FIR sensing has limited sensitivity, probably due to the use of thermal coupling levels. Herein, we report a novel FIR temperature measurement based on non-thermal coupling levels of NaGdF 4 :Yb3+/Er3+@NaGdF 4 @NaGdF 4 :Yb3+/Tm3+ core-shell-shell nanostructure, which has high sensitivity and robustness simultaneously. The relative sensitivity based on I 801 / I 654 and I 801 / I 841 of Tm3+ to Er3+ can reach up to 4.56 (303 K) and 3.82% K−1 (313 K), respectively. Between them, FIR of I 801 / I 841 is independent of excitation power and time. These results show the great potential of FIR based on non-thermal coupling levels in high-sensitive and robust temperature sensors. [ABSTRACT FROM AUTHOR]

The mullite phase in porcelain is important to the porcelain strength; however, its formation from clay minerals usually requires high temperature. Here we found that the activation of kaolin by citric acid would lower the formation temperature of mullite phase to 935.1 °C, which is 67.5 °C lower than that for the raw kaolin. Needle-like mullite crystal, a desired crystal shape in kaolin, could be observed in activated kaolin at 1050 °C. The reduction of mullite formation temperature is due mainly to the surface change in kaolin. Upon citric acid activation, the pseudohexagonal platelets of kaolinite crystal are disintegrated to non-uniform flakes, and the specific surface area increases from 8.18 m 2 /g to 31.21 m 2 /g, both leading to improved activity of kaolin and increased sintering driving force. The results are of interest in producing high-strength porcelain at reduced sintering temperatures and consequent energy saving for sintering process. [ABSTRACT FROM AUTHOR]

The NiFeW-LDHs with W-doping and oxygen vacancies via electrodeposition and corrosion exhibit remarked OER performance. [Display omitted] • W-doped NiFe-LDHs electrocatalyst is successfully prepared by electrodeposition and chemical corrosion. • The concentration of oxygen vacancies in NiFe-LDHs is increased via W-doping. • The low overpotential and excellent stability for OER of NiFeW-LDHs are the synergy of W-doping and oxygen vacancies. Electrochemical water splitting requires efficient electrocatalysts to accelerate the sluggish kinetics of the oxygen evolution reaction (OER). A promising nanoporous W-doped oxygen vacancy-containing NiFe layered double hydroxides (NiFeW-LDHs) electrocatalyst is directly grown on nickel foam via electrodeposition combined with chemical corrosion. With an appropriate amount of W dopant in NiFe-LDHs, the electronic structures of Ni and Fe are modulated by the changes in local environment, and the oxygen vacancy concentration is further optimized, resulting in abundant OER electrocatalytic active centers on the electrocatalyst surface. Due to the excellent electronic conductivity and three-dimensional nanoporous configuration, the representative NiFeW 3 -LDHs exhibit remarkable OER electrocatalytic activity with a low overpotential (211 mV at 10 mA cm−2), a small Tafel slope (36.44 mV dec–1), and fine stability (more than 120 h at 10 mA cm−2). The oxygen vacancy effectively modifies the intrinsic electronic structure of NiFe-LDHs, optimizes the adsorption energy of intermediates, and accelerates the OER. [ABSTRACT FROM AUTHOR]

Traditional algorithms to design hand-crafted features for action recognition have been a hot research area in the last decade. Compared to RGB video, depth sequence is more insensitive to lighting changes and more discriminative due to its capability to catch geometric information of object. Unlike many existing methods for action recognition which depend on well-designed features, this paper studies deep learning-based action recognition using depth sequences and the corresponding skeleton joint information. Firstly, we construct a 3D-based Deep Convolutional Neural Network (3 D 2 CNN) to directly learn spatio-temporal features from raw depth sequences, then compute a joint based feature vector named JointVector for each sequence by taking into account the simple position and angle information between skeleton joints. Finally, support vector machine (SVM) classification results from 3 D 2 CNN learned features and JointVector are fused to take action recognition. Experimental results demonstrate that our method can learn feature representation which is time-invariant and viewpoint-invariant from depth sequences. The proposed method achieves comparable results to the state-of-the-art methods on the UTKinect-Action3D dataset and achieves superior performance in comparison to baseline methods on the MSR-Action3D dataset. We further investigate the generalization of the trained model by transferring the learned features from one dataset (MSR-Action3D) to another dataset (UTKinect-Action3D) without retraining and obtain very promising classification accuracy. [ABSTRACT FROM AUTHOR]

The perovskite orthoferrite SmFeO 3 was synthesized by the hydrothermal method. The Néel temperature of this material was found to be 655 K by temperature-dependent magnetization measurements. Magnetic field-dependent magnetization of the material at 300 K revealed typical weak ferromagnetic behaviour. Dielectric analysis showed a ferroelectric phase transition at 480 K. The structural and magnetic properties of SmFeO 3 were also characterized using Mössbauer spectra, which also confirmed this structural transition. The remanent polarization determined by the positive-up-negative-down (PUND) method was approximately 0.012 μC/cm 2 at 173 K. Therefore, the results presented here indicate that SmFeO 3 is multiferroic at temperatures above room temperature. Our analysis shows that the material's non-centrosymmetric Pna2 1 structure is likely to be responsible for the ferroelectricy in SmFeO 3 rather than the Pbnm structure or the magnetic structure. [ABSTRACT FROM AUTHOR]

Microalloyed Mo 5 SiB 2 alloys were fabricated by spark plasma sintering (SPS). The effects of different sintering temperatures and yttrium additions on the microstructure and high-temperature oxidation behavior of the alloys were systematically investigated. For the optimum Mo-13Si-25B-0.2Y alloy sintered at 1750 °C, adding small amounts of rare-earth yttrium refined the grains to an average size of ~400 nm without reducing the Mo 5 SiB 2 content. During oxidation at 1300 °C, the "fishlike" Y 2 Si 2 O 7 and Y 2 O 3 phases were formed and anchored on the surface of the oxide layers, promoting the oxidation of silicon and accelerating the formation and coverage of the oxide protective film. Moreover, yttrium promoted the in situ deformation of a self-generated protective borosilicate glass film under high-temperature oxidation by accelerating Si oxidation. With prolonged oxidation time, viscous flow occurred to repair the internal cracks and tiny defects caused by the volatilization of MoO 3 and prevented the inward diffusion of oxygen, as evidenced by a low oxidation rate constant of 0.95 mg2 cm−4 h−1 at 1300 °C for 50 h in the Mo-13Si-25B-0.2Y alloy. • Yttrium doped Mo-13Si-25B alloy was prepared by SPS. • The yttrium-containing borosilicate film was formed in situ at 1300 °C. • Yttrium addition promoting the oxidation of silicon and accelerating the formation and coverage of the oxide protective film. • This oxide film own the ability of self-recovery at high temperatures. • This alloy displays excellence high-temperature oxidation resistance. [ABSTRACT FROM AUTHOR]

The sublingual mucosa (SLM) is utilized as the site for sublingual immunotherapy (SLIT) to induce tolerance against allergens. The contribution of SLM-dendritic cells (SLM-DCs) has not been clarified. The aim of this study was to examine the dynamics and phenotype of SLM-DCs after topical antigen painting and SLIT. SLM-DCs were histologically evaluated after FITC painting. A novel murine Japanese cedar pollinosis (JCP) model was generated and change in SLM-DCs after SLIT was examined. The density of SLM-DCs was clearly lower compared with the buccal mucosa and dorsal surface of the tongue. Topical FITC painting on the SLM induced maximal recruitment of submucosal DCs (smDCs) at 6 h, but most smDCs had vanished at 24 h. Repeated painting on the SLM induced exhaustion and conversion of the smDC phenotype. CD206 high CD11c low round-type cells with fewer dendrites and less lymph node migration capacity became dominant. In the murine model of JCP, SLIT efficiently inhibited clinical symptoms and allergen-mediated immunological responses. SLIT markedly reduced the number of SLM-DCs, converted to the round-type dominant phenotype and inhibited the activation of regional lymph node DCs. Topical antigen painting on the SLM induced rapid exhaustion and conversion of smDCs. The unique dynamics of SLM-DCs may contribute to tolerance induction in SLIT. [ABSTRACT FROM AUTHOR]

Black spot rot caused by Alternaria alternata is one of the major postharvest disease of apple fruit during logistic. This study evaluated in vitro inhibitory effect of 2-hydroxy-3-phenylpropanoic acid (PLA) at various concentrations on A. alternata and the possible mechanisms involved in its action. Results showed that different concentrations of PLA inhibited conidia germination and mycelial growth of A. alternata in vitro, and 1.0 g L−1 was the lowest effective concentration to suppress A. alternata growth. Moreover, PLA significantly reduced relative conductivity and increased malondialdehyde and soluble protein contents. PLA also increased H 2 O 2 and dehydroascorbic acid contents, but reduced ascorbic acid content. Additionally, PLA treatment inhibited catalase, ascorbate peroxidase, monodehydroascorbate acid reductase, dehydroascorbic acid reductase and glutathione reductase activities, whereas promoted superoxide dismutase activity. All these findings suggest that the possible mechanisms involved in the inhibitory effect of PLA on A. alternata included damaging the cell membrane integrity to cause electrolyte leakage and destroying reactive oxygen species balance. • 2-hydroxy-3-phenylpropanoic acid inhibited conidia germination and mycelial growth of Alternaria alternata. • 2-hydroxy-3-phenylpropanoic acid destroyed the reactive oxygen species balance in A. alternata to inhibit its growth. • 2-hydroxy-3-phenylpropanoic acid damaged the cell membrane integrity of A. alternata. [ABSTRACT FROM AUTHOR]

• Risk assessment model is beneficial to early detection of high-risk groups of depression. • Five machine learning models can identify the prevalence of depression in the NHANES data. • Catboost achieved a high performance for identifying middle-aged and elderly depression. Depression is one of the most common mental health problems in middle-aged and elderly people. The establishment of risk factor-based depression risk assessment model is conducive to early detection and early treatment of high-risk groups of depression. Five machine learning models (logistic regression (LR); back propagation (BP); random forest (RF); support vector machines (SVM); category boosting (CatBoost) were used to evaluate the depression among 8374 middle-aged people and 4636 elderly people in the NHANES database from 2011 to 2018. In the 2011–2018 cycle, the estimated prevalence of depression was 8.97% in the middle-aged participants and 8.02% in the elderly participants. Among the middle-aged and elderly participants, CatBoost was the best model to identify depression, and its area under the working characteristic curve (AUC) reaches the highest. The second is LR model and SVM model, while the performance of BP and RF model was slightly worse. The primary influencing factor of depression in middle-aged male is alanine aminotransferase. All five machine learning models can identify the occurrence of depression in the NHANES data set through social demographics, lifestyle, laboratory data and other data of middle-aged and elderly people, and among five models, the CatBoost model performed best. [ABSTRACT FROM AUTHOR]

With the construction of the Three Gorges Reservoir (TGR), water impoundment began in 2003. The reservoir water level (RWL) has been annually adjusted to a fluctuation level between 145 and 175 m above sea level (a.s.l.) since 2008. Numerous large scale ancient landslides have been reactivated in the region. This paper focuses on the reactivation characteristics and influence of hydrological inducing factors on deformation of a massive ancient reservoir landslide. The Taping landslide is taken as an example, and its geological setting, material composition, structural characteristics and spatiotemporal deformation characteristics of the landslide are presented. According to the surface deformation characteristics, the Taping landslide can be divided into three subzones. Then, an attribute reduction algorithm based upon neighborhood rough set theory is used to quantitatively analyze the influences of key hydrological factors on the movements within the three subzones of the landslide. Long-term monitoring data are used to identify the key threshold values that induce fast movements within the three subzones of the landslide. Finally, the reactivation mechanism of the Taping landslide is proposed. The results show that the Taping landslide is in a state of periodically consistent creep deformation. The movements within the three subzones of the Taping landslide are affected by different hydrological factors. For the leading section, the hydraulic gradient is the most important hydrologic factor affecting the slope movement, and 0.07 is the key hydraulic gradient threshold for fast movement. For the middle section, rainfall and hydraulic gradient are the two most important hydrologic factors affecting the slope movement. The average daily precipitation over the last seven days and hydraulic gradients of 10 mm and 0.15 are the threshold values that induce its fast movement. For the rear section, the slope movement is mainly affected by the ground water level (GWL), and a GWL of 185.5 m a.s.l., is identified as the key threshold value that induces its fast movement. The findings in this study can help in managing reservoir landsides and designing landslide reinforcements in the regions of the world with geological settings similar to that of the TGR region. • Spatiotemporal deformation characteristics of a massive reservoir ancient landslide are presented. • Influence of key hydrological factors on the movement of a massive reservoir ancient landslide are quantitatively analyzed. • Data analysis identifies the key threshold values that induces fast movement of three subzones in the landslide. [ABSTRACT FROM AUTHOR]

Nanomaterials with shifting or mixed redox states is one of the most common studied nanozyme with peroxidase-like activity for chemodynamic therapy (CDT), which can decompose hydrogen peroxide (H 2 O 2) of tumor microenvironment into highly toxic reactive oxygen species (ROS) by a nano-catalytic way. However, most of them exhibit an insufficient catalytic efficiency due to their dependence on catalytic condition. Herein, a potential methodology is proposed to enhance their enzymatic activity by accelerating the redox cycling of these nanomaterials with shifting or mixed redox states in the presence of X-ray. In this study, the nanocomposite consisting of SnS 2 nanoplates and Fe 3 O 4 quantum dots with shifting or mixed redox states (Fe2+/Fe3+) is used to explore the strategy. Under external X-ray irradiation, SnS 2 cofactor as electron donor can be triggered to transfer electrons to Fe 3 O 4 , which promotes the regeneration of Fe2+ sites on the surface of the Fe 3 O 4. Consequently, the regenerated Fe2+ sites react with the overexpressed H 2 O 2 to persistently generate ROS for enhanced tumor therapy. The designed nanocomposite displays the synergistic effects of radiotherapy and CDT. The strategy provides a new avenue for the development of artificial nanozymes with shifting or mixed redox states in precise cancer treatments based on X-ray-enhanced enzymatic efficacy. [ABSTRACT FROM AUTHOR]

In this study, the model compound esculetin that has functional groups typical for natural organic matter (NOM) was used to ascertain the nature of the characteristic bands in the differential UV–visible absorbance spectra (DAS) associated with the formation of metal-NOM complexes. The binding of ten different metal ions (Cu(II), Ni(II), Co(II), Fe(III), Cr(III), Al(III), Zn(II), Ca(II), Mg(II) and Pb(II)) with esculetin generate four bands in the DAS. These bands are similar to those present in the DAS of metal-NOM complexes. The UV–visible absorbance spectra of the metal-esculetin systems were calculated using time-dependent density functional theory (TD-DFT). The TD-DFT results demonstrate that the prominent features of the DAS of esculetin are primarily associated with the electron transitions between the molecular orbitals near the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) in the metal-esculetin complex. Charge decomposition analysis (CDA) results demonstrated that these electron transitions originate from the esculetin fragment to the Zn(II) fragment in the complex. Covalent indexes [(χ m)2r c ] of the metal ions were found to be correlated with the metal-specific features of the DAS of metal-esculetin systems. The strength of the linear correlations between the quantitative parameters of the electron density of the bond critical points (BCP) is indicative of the strength of the metal-esculetin interactions. [Display omitted] • Different absorbance spectra features of ten metal/esculetin complexes are different. • Peaks in DAS of esculetin and NOM induced by metal ions binding are similar. • Peaks in DAS are generated by electron transitions from esculetin to metal. • Peak intensity of spectra correlate with covalent index of metals ( (χ m) 2 r c). • Spectra properties relate to electron density at interaction of metal/esculetin. [ABSTRACT FROM AUTHOR]

Expansive soils are widely distributed in the Danjiangkou Reservoir region (DRR), China. In recent years, with a rise in the reservoir water level (RWL), reservoir-related expansive soil landslides have gradually become a serious issue in this area. However, few studies on reservoir-related expansive landslides have been reported. Taking the Jingang landslide as a case study, a detailed analysis was performed to interpret the movement characteristics of the landslide under the influence of rainfall and the RWL, based on the comprehensive in-situ monitoring data and laboratory soil tests. The Jingang landslide is a large-scale expansive soil landslide triggered by reservoir operation. Available data indicate that the displacement of the Jingang landslide displays step-like trends and mainly occurs during high RWL or filling operation periods. Both seasonal rainfall and RWL variation are important factors that cause the ground movement of a landslide. The onset of rapid ground movement usually corresponded to an RWL of 161–163 m a.s.l.. The motion pattern is primarily retrogressive, and the displacement velocity increases towards the toe, which could reach 41 mm/month. The free swelling rates of the soils in the Jingang landslide are approximately 40–60%. The stability calculation indicates that the factor of safety of the Jingang landslide decreases from 1.049 to 1.038 due to the swell pressure of expansive soil, and this has a significant adverse effect on the landslides. • The Jingang landslide is a reservoir-induced large-scale expansive soil landslide, the related studies are rare. • Both rainfall and RWL variation are important factors that cause ground movement of the landslide. • The swell pressure of expansive soil has a significant adverse effect on the landslide. [ABSTRACT FROM AUTHOR]

To assess the accuracy of the rapid diagnostic test for malaria diagnosis in children under 5 years of age. As of August 31, 2020, PubMed, Web of Science and Cochrane Library databases had been systematically searched. Relevant data were extracted and meta-analysis was carried out. A random effects model was used for subgroup analysis. According to the inclusion criteria, a total of 26 studies were included in this meta-analysis. The pooled sensitivity and specificity were 0.92 (95% confidence interval 0.83–0.96) and 0.92 (0.86–0.95), the parasite-specific lactate dehydrogenase-based test were 0.96 (0.85–0.98) and 0.93 (0.86–0.95), the histidine-rich protein 2-based test were 0.94 (0.84–0.98) and 0.86 (0.77–0.91). This meta-analysis showed that rapid diagnostic test had good accuracy in diagnosing malaria in children under 5 years of age. And the diagnostic performance of parasite-specific lactate dehydrogenase test was better than that of the histidine-rich protein 2 test. [ABSTRACT FROM AUTHOR]

• porous atomic layered 2H-MoS 2 was produced by one-step calcination treatment. • porous atomic layered 2H-MoS 2 exhibited an excellent catalytic activity for NRR. • porous structure activated the inert basal plane of MoS 2. • porous structure induced the generation of adjacent Mo atom pairs. • Adjacent Mo atom pairs were acted as active sites. MoS 2 has been proven to be an efficient NRR electrocatalyst, the activation of inert basal plane and rational utilization of basal plane have become the key to further increasing the activity. The defects of basal plane help to expose active sites, however, they cannot activate basal plane to promote NRR. Herein, based on the calculation results, we designed porous atomic layered 2H-MoS 2 (PAL-MoS 2) by one-step calcination treatment. The porosity of the basal plane effectively utilizes basal plane atoms while the presence of adjacent Mo atom pairs improves the NRR performance. A high Faradic efficiency of 44.36 % and a sizeable NH 3 yield of 3405.55 μg h−1 mg cat −1 (1.98 μg h−1 cm−2) at ‒0.1 V vs. reversible hydrogen electrode are obtained in 0.1 M HCl under ambient conditions, as far as we know, outperforming most of Mo-based NRR electrocatalysts reported before. Furthermore, this catalyst also exhibits high selectivity, electrochemical stability and good performance characterization. [ABSTRACT FROM AUTHOR]

Calcium lignosulfonate is a common anionic surfactant. In this study, calcium lignosulfonate (SL) was employed to modified chalcopyrite surface and promote chalcopyrite bioleaching. The bioleaching experiments revealed that in the absence of SL, the bioleaching rate of chalcopyrite was slower at the initial stage, and it was accelerated after a period of 12 days. Conversely, when SL was introduced during the bioleaching process, the bioleaching rate of chalcopyrite was a significant acceleration within the first 6 days. After the introduction of SL, the bioleach rate of chalcopyrite was about 3 times faster in the first 12 days. This highlights the effect of SL on expediting the bioleaching efficiency of chalcopyrite. Mechanism research indicates that after the introduction of SL, the adsorption energy of bacteria on mineral surface decreased from −2.71 to −4.37 mJ/m2, the adhesion of bacterial was promoted. Further analysis through scanning electron microscopy, electrochemical analysis, and X-ray photoelectron spectroscopy demonstrates that after SL modification, the structure of jarosite on the chalcopyrite leaching residues became denser, and the relative content of Fe (III) and S (Ⅵ) was increased from 56.4 % and 84.6% to 65.4% and 91.5%, respectively. These alterations are highly conducive to electron transfer processes and chalcopyrite oxidation. • Innovative use of calcium lignosulfonate to enhance the effect of bioleaching. • Found that calcium lignosulfonate could accelerate the bioleaching speed. • Found that calcium lignosulfonate affects the adhesion of bacteria on mineral. • Reveal the effect of calcium lignosulfonate on the surface passivation layer. [ABSTRACT FROM AUTHOR]

Concentrations of several toxic disinfection by-products (DBP), notably haloacetonitriles (e.g., trichloroacetonitrile, TCAN) and haloketones (e.g., di- and trichloropropanone, DCPN and TCPN, respectively) are affected by chlorination conditions and the inherent instability of these DBPs. In this study, effects of temperature, chlorine dose and reaction time on the formation of TCAN, DCPN and TCPN were interpreted using the approach of differential absorbance spectroscopy. Experimental data obtained for a wide range of water quality conditions demonstrate that in some cases the concentrations of some of the unstable DBPs increased rather than decreased at low temperatures and realistically long contact times. Despite the presence of pronounced changes of the kinetics of generation and degradation of these DBPs at varying temperatures and chlorine doses, their concentrations were strongly correlated with the concurrent changes of spectroscopic properties of DOM quantified via differential absorbance measurements at 272 nm (ΔA 272). The maximum values of TCAN, DCPN and TCPN concentrations observed for the chlorination of eight different surface waters occur at the relative decreases of absorbance at 272 nm (defined as RΔA 272) values of ca. 0.32 (±0.03), 0.24 (±0.05), and 0.42 (±0.03), respectively. The activation energies of degradation reactions of unstable DBPs were examined and the results indicate that TCAN and TCPN are caused by their hydrolysis with OH− while the degradation of DCPN is mainly caused by halogenation reaction with HOCl. These results in this study may be important for controlling the formation of unstable DBPs and further optimization of drinking water treatment. Image 1 • The generation and degradation of unstable DBPs are site-specific. • Breakdown of TCAN, DCPN and TCPN are observed during long reaction time. • Breakdown of TCAN, DCPN and TCPN are seriously affected by Cl 2 dose and temperature. • The yield of TCAN, DCPN and TCPN increase as ΔA 272 initially and decrease afterward. • Ratio of ΔA 272 at the maximum level for TCAN, DCPN and TCPN are 0.32, 0.24 and 0.42. [ABSTRACT FROM AUTHOR]

• Six Gaussian bands comprise differential absorbance spectra of all examined waters. • Bands A1-A4 in the spectra of chlorinated compounds show dependence of conjugation. • Spectral parameters from long wavelength have high correlation with DBPs formation. This study compared chlorination-induced changes of the properties of natural organic matter (NOM) represented by standard humic substances and NOM present in pristine and anthropogenically-affect reservoirs, rivers, groundwater and seawater. The chlorination-induced changes of NOM properties were quantified using the differential absorbance spectra (DAS) which were processed via numeric deconvolution. Six Gaussian bands were found to comprise the DAS of all examined waters. These bands (denoted as A0, A1, A2, A3, A4 and A5, respectively) have maxima located at ca. 200, 240, 276, 316, 385 and 547 nm. The bands A1-A4 were observed in the DAS of representative model chlorinated compounds. Quantum chemical (QC) calculations were carried out to examine the intrinsic nature of these bands and electronic transitions associated with them. QC data demonstrate that bands A1 and A2 are present in almost all aromatic organic species, A3 is likely to be associated with acetophenone- and/or styrene-like groups. A4 can be attributed to the engagement of m-hydroxyaromatic and flavone-type groups typical for the polyphenolic moiety in NOM and known to be the key precursors of disinfection by-product (DBP) formation. Thus, the intensity of band A4 is predicted to be an especially strong predictor of DBP formation. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Dual-band electrochromic smart windows can selectively regulate the transmittance of visible and near-infrared (NIR) light, thereby significantly reducing energy consumption in buildings. However, the selective regulation for visible and NIR regions often relies on the integration of multiple components, together with meticulous design and fabrication. Herein, we propose the stacking of amorphous tungsten oxide (a-WO 3) on the surface of Prussian blue (PB) through a straightforward magnetron sputtering deposition. Benefiting from the numerous voids-containing structures in the microstructure of a-WO 3 films, the stacking structures are conducive to the insertion and transport of electrolyte ions, ensuring the electrochemical activity and electrochromic performance of the inner PB layer. The prepared PB/WO 3 bilayer thin film can achieve three functionality modes in dual-band electrochromism: "bright", "warm", and "dark", with high optical modulation of 74.9 % at 700 nm and 80.3 % at 1300 nm, respectively. Additionally, they demonstrate fast coloring/bleaching response (2.9/7.6 s at 700 nm and 6.0/6.2 s at 1300 nm) and satisfying cycling stability (retaining 95.3 % of its initial modulation after 500 cycles). The bilayer thin films based on amorphous electrochromic materials with an intrinsic abundance of voids-containing structures introduce a novel approach to the independent dual-band modulation for demanded light/thermal control. • Stacked-structure PB/WO 3 bilayer thin films are designed for dual-band electrochromism. • The amorphous WO 3 film facilitates the insertion/desertion of electrolyte ions. • The prepared PB/WO 3 bilayer thin films exhibit impressive dual-band electrochromic performance. [ABSTRACT FROM AUTHOR]

A novel injectable pH-responsive poly (γ-glutamic acid) (PGA)-silica hybrid hydrogel with controlled structural and physicochemical properties has been developed. Hybrid hydrogels are composited of PGA and 3-glycidoxypropyl trimethoxysilane (GPTMS) with different content of silica which is derived from hydrolyzed tetraethylorthosilicate (TEOS). In this hybrid system, GPTMS is employed as a coupling agent and TEOS is used for adjusting the silica content. Effects of the silica content on the morphology, microstructure, mechanical strength, swelling behavior, drug delivery performance, conductivity and cytocompatibility are investigated. Results reveal that the microporous structure, compressive strength, swelling as well as drug delivery behavior, and in vitro cytocompatibility of hybrid hydrogels are effectively tailored by adjusting the silica content. Besides the pH-responsive swelling and drug release behaviors, the hybrid hydrogel possesses good conductivity as well as high sensitivity to external strain. Therefore, the prepared hybrid hydrogels reveal great application potential as promising injectable biomaterials for biomedical applications. Image 1 • A novel type of injectable pH-responsive poly (γ-glutamic acid)-silica hybrid hydrogel were developed. • The physicochemical properties of hybrid hydrogels can be tailored by simply adjusting the content of incorporated TEOS. • Hybrid hydrogel provided accurate and reliable detection of subtle physiological signals. [ABSTRACT FROM AUTHOR]

Hollow nanostructures have been evoked considerable attention owing to their intriguing hollow interior for important and potential applications in drug delivery, lithium battery, catalysis and etc. Herein, Bi 2 S 3 hollow microspheres with rod-based urchin-like nanostructures (denoted as U-BSHM) were synthesized through a facile and rapid ion exchanging method using a particular hard template. The growth mechanism of the U-BSHM has been investigated and illustrated by the morphological evolution of the different samples at early stages. The obtained U-BSHM exhibited strong and wide UV–vis–NIR absorption ability and outstanding photothermal conversion efficiency. Thus, the U-BSHM can be used as spatio-temporal precisely controlled carrier by loading the mixture of 1-tetradecanol (phase change material, PCM) with melting point around 38 °C and hydrophilic chemotherapeutic doxorubicin hydrochloride (denoted as DOX) into the hollow interior to form (PCM + DOX)@Bi 2 S 3 nanocomposites (denoted as PD@BS) for photoacoustic (PA) imaging and chemo-photothermal therapy of the tumors. When exposed to 808 nm near infrared light (NIR) laser irradiation, this nanocomposites could elevate the temperature of the surroundings by absorption and conversion of the NIR photons into heat energy, which inducing the triggered release of DOX from the hollow interior once the temperature reach up to the melting point of PCM. The killing efficiency of the chemo-photothermal therapy was systematically validated both in vitro and in vivo. In the meanwhile, the implanted tumor was completely restrained through PA imaging and combined therapies. Therefore, this kind of urchin-like hollow nanostructures would be used as important candidates for the multimodal bioimaging and therapy of tumors. Rod-based sea urchin-like Bi 2 S 3 hollow microspheres have been achieved using a hard template assisted polyol method via ion exchanging process, which is a promising theranostic nanoplatform owing to their superior Visible-NIR absorption and photothermal conversion properties. Image 1 [ABSTRACT FROM AUTHOR]

• The paper introduced a new composite depressant. • Invested the effect of the mineral particle size on the flotation recovery. • Galena can be effectively inhibited by using a composite depressant. • Revealed the mechanism of composite depressant depress galena. In this study, the inhibitory effect of a composite depressant consisting of sodium sulfite and sodium lignosulfonate mixed at a molar ratio of 5:1 on Cu–Pb flotation separation was analyzed. The results of the mineral flotation tests show that both chalcopyrite and galena are floatable in a pH range of 6–12 and the composite depressant has a stronger inhibitory effect on galena than that of single inhibitors. The particle-size analyses of the concentrates and tailings show that it is difficult to inhibit the floatability of fine-grained galena using a single depressant, but the composite depressant can effectively deteriorate its floatability. The results obtained from zeta potential measurements and SEM reveal that the zeta potential of galena becomes more negative after a composite depressant is added because of the greater adsorption of sulfite and lignosulfonate ions on the surface of the galena. The XPS results show that sodium sulfite chemically reacts with the surface of galena and that hydrogen bonds are the main driving force of the adsorption of sodium lignosulfonate onto the surface of galena. The use of a combination of sodium sulfite and sodium lignosulfonate increases their adsorption onto the surface of fine-grained galena. [ABSTRACT FROM AUTHOR]

Thermodynamic and kinetic aspects of the formation of trihalomethanes and haloacetic acids determined based on the quantum chemical (QC) simulations were compared in this study with the experimental data generated using the differential spectroscopy approach in chlorination and chloramination. The ratios of the slopes of the correlations between -DlnA 350 values and individual DBPs concentrations (S NH2Cl /S HOCl) were observed to be linearly correlated with the ratios of the Gibbs free energies (ΔG NH2Cl /ΔG HOCl) of the corresponding reactions of chloramine and chlorine with acetaldehyde which was used as a model DBP precursor in QC simulations. Further QC examination of the kinetics of chlorination and chloramination of the model compound acetoacetic acid showed that the activation energy of reactions between monochloramine that directly participates in substitution reactions to form mono-, di and tri-halogenated intermediates are 2–3 times higher than those of HOCl formed via the hydrolysis monochloramine. This result confirms that the interactions of chloramine with NOM and ensuing DBP formation are primarily mediated by the free chlorine released as a result of the hydrolysis of monochloramine while direct halogenation of NOM by monochloramine is likely to provide a small contribution to DBP formation. Image 1 • -DlnA 350 is linear with most of individual DBPs yields in chlor(am)ination. • Ratio of slopes (S NH2Cl /S HOCl) for individual DBPs are linear with ΔG NH2Cl /ΔG HOCl. • Direct halogenation of NOM by NH 2 Cl contribute to small fraction of DBP formation. • The activation energy of NOM reaction with NH 2 Cl is higher than HOCl. • Tri-chlorinated HAAs and THMs are suppressed in chloramine due to trace level HOCl. [ABSTRACT FROM AUTHOR]

In several recent issues of The Lancet , we identified a few common pitfalls in the analysis of clinical trial and medical data in the published articles (Mok et al., 2019; Herrlinger et al., 2019; Reindl-Schwaighofer et al., 2019; He et al., 2019). Without careful validation of model assumptions, even the primary endpoint of the trial might be analyzed using improper statistical methods. We carried out an in-depth analysis of the statistical issues in four real clinical trials, which highlights the importance of statistics in the medical field. With every effort, biostatisticians need to work with clinicians closely to take the most appropriate statistical approaches to data analysis; otherwise the conclusions drawn from the data might be problematic or misleading. [ABSTRACT FROM AUTHOR]

Plutella xylostella is an important cruciferous crop pest with a serious resistance to multiple insecticides, a novel natural compound, 2,3-dimethyl-6-(1-hydroxy)-pyrazine were isolated, that showed significant repellent activity against P. xylostella with olfactory system as a potential target. Eight odorant-binding proteins (OBPs) were determined as candidate target genes using RT-qPCR (Quantitative reverse transcription PCR), most of them were clustered with OBPs from Spodoptera frugiperda. Fluorescence competitive binding assays showed that PxylPBP2 (Pheromone binding protein) and PxylOBP3 had Ki values of 7.13 ± 0.41 μM and 9.56 ± 0.35 μM, indicating a high binding affinity to the pyrazine. Moreover, the binding style between these two OBPs and the pyrazine was determined as a hydrophobic interaction by using molecular docking. The binding between PxylPBP2 and the pyrazine was found to be more stable, and the carbon atoms of C-2 and C-3 in this pyrazine showed potential optimization characteristics. Both PxylPBP2 and PxylOBP3 were highly expressed in the antennae of both sexes. These results can be used to design and develop novel green pesticides with the pyrazine as the active or lead compound to reduce the utilization of chemical pesticides and postpone development of resistance. [ABSTRACT FROM AUTHOR]

Physical activity is a crucial part of an active lifestyle for haemophiliac children. However, the fear of bleeds has been identified as barriers to participating physical activity for haemophiliac children even with prophylaxis. Lack of evidence and metrics driven by data is key problem. We aim to develop machine learning models based on clinical data with multiple potential factors considered to predict risk of physical activity bleeding for haemophilia children with prophylaxis. From this cohort study, we collected information on 98 haemophiliac children with adequate prophylaxis (trough FVIII:C level > 1 %). The involved potential predictor variables include demographic information, treatment information, physical activity, joint evaluation, and pharmacokinetic parameters, etc. We applied CoxPH, Random Survival Forests (RSF) and DeepSurv to construct prediction models for the risk of bleeding during physical activities. All three survival analysis models were internally and externally validated. A total of 98 patients were enrolled in this study. Their median age was 7.9 (5.5, 10.2) years. The CoxPH, RSF and DeepSurv models' discriminative and calibration abilities were all high, and the RSF model had the best performance (Internal validation: C-index, 0.7648 ± 0.0139; Brier Score, 0.1098 ± 0.0015; External validation: C-index, 0.7260 ± 0.0154; Brier Score, 0.0930 ± 0.0018). The prediction curves demonstrated that the developed RSF model can distinguish the risks well between bleeding and non-bleeding patients, as well as patients with different levels of physical activity. Meanwhile, the feature importance analysis confirmed that physical activity bleeding was deduced by comprehensive effects of various factors, and the importance of different factors on bleeding outcome is discrepant. This study revealed from the mechanism that it is necessary to incorporate multiple factors to accurately predict physical activity related bleeding risk. In clinical practice, the designed machine learning models can provide guidance for children with haemophilia A to positively participate in physical activity. • Predicting the risk of bleeding during physical activity in children withhaemophilia A • Three machine learning methods used to construct prediction models • The RSF model had the best discriminative and calibration • The models can guide children with haemophilia regarding participation in physical activities [ABSTRACT FROM AUTHOR]

Electroencephalogram (EEG) signal processing has emerged as a critical problem for biometric applications due to its real-time requirement. While compressive sensing is an efficient method for signal compression, its application in EEG signal processing is limited due to its noise unawareness during transmission and time-consuming reconstruction procedure. In this paper, we propose a noise-aware sparse Bayesian learning approach with block structure (NA-BSBL) to achieve higher efficiency on data compression, reconstruction and classification. By applying novel structure for parameter and introducing the Mahalanobis Distance, our approach achieves an almost 20% reconstruction performance lift and 10% accuracy lift under noise condition. For further application of reconstructed EEG signal, we extract both the spatial and frequency domain features for classification. Experimental results show that the proposed approach can achieve 94% classification accuracy with 16% speed up compared with the conventional approach. • A compressive sensing approach is applied on Electroencephalography (EEG) signal for high compression rate. • A reconstruction approach is proposed for EEG signal under noise environment as well as better processing efficiency. • A feature learning approach is proposed for better classification accuracy. • The proposed reconstruction and feature learning approach achieves a 94% classification accuracy for EEG signal. [ABSTRACT FROM AUTHOR]