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In this paper, an optimized method based on gas chromatography/time-of-flight mass spectrometry (GC-TOFMS) platform has been developed for the analysis of gut microbial-host related co-metabolites in fecal samples. The optimization was performed with proportion of chloroform (C), methanol (M) and water (W) for the extraction of specific metabolic pathways of interest. Loading Bi-plots from the PLS regression model revealed that high concentration of chloroform emphasized the extraction of short chain fatty acids and TCA intermediates, while the higher concentration of methanol emphasized indole and phenyl derivatives. Low level of organic solution emphasized some TCA intermediates but not for indole and phenyl species. The highest sum of the peak area and the distribution of metabolites corresponded to the extraction of methanol/chloroform/water of 225:75:300 (v/v/v), which was then selected for method validation and utilized in our application. Excellent linearity was obtained with 62 reference standards representing different classes of gut microbial-host related co-metabolites, with correlation coefficients ( r 2 ) higher than 0.99. Limit of detections (LODs) and limit of qualifications (LOQs) for these standards were below 0.9 nmol and 1.6 nmol, respectively. The reproducibility and repeatability of the majority of tested metabolites in fecal samples were observed with RSDs lower than 15%. Chinese rhubarb-treated rats had elevated indole and phenyl species, and decreased levels of polyamine such as putrescine, and several amino acids. Our optimized method has revealed host-microbe relationships of potential importance for intestinal microbial metabolite receptors such as pregnane X receptor (PXR) and aryl hydrocarbon receptor (AHR) activity, and for enzymes such as ornithine decarboxylase (ODC). [ABSTRACT FROM AUTHOR]

In this paper, we systematically investigate the structural, electronic and magnetic properties of hexagonal group-III nitride monolayers with point defects and alloying on the basis of first-principles calculations. Six typical point defects including three vacancies and three antisites are modeled in pure AlN, GaN and InN monolayers. The defect-induced modifications of band gaps and magnetic properties are demonstrated. The vacancy of nitrogen, with lowest formation energy, metalizes the semiconducting nitride monolayers. The defects losing single group-III atom introduce net magnetic moment to the systems, while others maintain non-magnetic. For ordered alloy monolayers, the AlGaN and InGaN systems are taken into consideration. The compositional variation is achieved by atomic substitution in supercells with different sizes. We find that the lattice constant and cohesive energy follow good linear relation with concentration while a slight bowing effect is observed for the band gap. These results provide a development in defective and alloy nitride monolayers and extend the potential applications. [ABSTRACT FROM AUTHOR]

As the gold standard polymer for drug delivery system, polyethylene glycol (PEG) has excellent biocompatibility. It's reported that the low nonspecific interactions between PEG and body contribute to its biocompatibility. However, here we discover dynamic biological interactions exist between PEG and cells on the molecular level. PEG (2 kD) can induce metabolism modulations and survival autophagy by creating an intracellular hypoxic environment, which act as cellular survival strategies in response to the hypoxia. In the cellular adaption process during hypoxia, PEG-treated cells decrease energy consumption by reducing cell growth rate, increase energy supply by amino acid catabolism in a short period, and survival autophagy over a relatively long period, to keep energy homeostasis and survival. Our research provides molecular insights for understanding the mechanism underlying the excellent biocompatibility of PEG, which will be of fundamental importance for further related studies on other polymers and development of polymeric materials with improved characteristics. [ABSTRACT FROM AUTHOR]

Endothelial progenitor cells (EPCs), as precursors to endothelial cells, play a significant part in the process of endogenous blood vessel repair and maintenance of endothelial integrity. Adiponectin (APN) is an adipocyte-specific adipocytokine. In this study, we aim to test whether we transplant a combined graft of EPCs transfected with the adiponectin gene into a rat model of cerebral ischemia could improve functional recovery after middle cerebral artery occlusion (MCAO). Sprague-Dawley (SD) rats were randomly divided into a MCAO control group, a MCAO EPC treatment group, and a MCAO LV-APN-EPC treatment group. A focal cerebral ischemia and reperfusion model was induced by the intraluminal suture method. After 2 h of reperfusion, EPCs were transplanted by injection through the tail vein. A rotarod test was conducted to assess behavioral function before MCAO and on days 1, 7, and 14 after MCAO. After 14 d, TTC staining, CD31 immunofluorescence, and TUNEL staining were used to evaluate infarct volume, microvessel density, and cell apoptosis. Results revealed that behavioral function, infarct area percentage, microvessel density, and cell apoptosis rates were more favorable in the LV-APN-EPC treatment group than in the EPC treatment group. These data suggested that gene-modified cell therapy may be a useful approach for the treatment of ischemic stroke. [ABSTRACT FROM AUTHOR]

In this paper, the influences of composition on Raman scattering from Ge/Si-GeSi core-shell nanowire heterostructures standing along [011] and [111] crystal directions are numerically investigated. Uniform, linear and spontaneous nonlinear composition profiles (CPs) in GeSi alloy shell are taken into consideration. In uniform CP case, clear double peaks in Raman spectra contributed by core and shell are observed. The strain-induced shift follows linear relation with Ge concentration and nonlinear relation with shell thickness. Larger strain-induced shifts are obtained in nanowires along [111] direction. In linear CP case, the peaks contributed by shell cannot be distinguished in the total spectra and plateaus are formed on the low frequency side. Moreover, the nonlinear CP accounts for the spontaneous composition transition near heterointerface during lateral epitaxy of GeSi shell. Due to the rapid Ge concentration transition, Raman spectra are shown nearly identical to uniform CP cases. [ABSTRACT FROM AUTHOR]

Solubility of benzoin in three binary solvent systems of acetone + ethanol, acetone + 1-butanol, acetone + 1-propanol was measured by static analytical method ranging from 283.15 K to 318.15 K at atmospheric pressure. Density functional theory (DFT) and molecular dynamic (MD) simulation were employed to investigate relationship between solute and solvent molecules. According to results of Solvation free energy and hydrogen bond strength, the solubility of benzoin increases with increasing value of hydrogen bond strength. Radial distribution function (RDF) resulted shows that ethanol, 1-butanol, 1-propanol have an effect on the acetone aggregation in binary mixed solvents, which means it will weaken the interactions between benzoin and acetone molecules. Therefore, solubility behavior was influenced by both solute-solvent and solvent-solvent interactions. The solubility data was correlated with Apelblat equation, CNIBS/R-K equation, and λh model, respectively, and the CNIBS/R-K equation shows the best correlations in three thermodynamic equations. Thermodynamic properties of mixing enthalpy, entropy, and Gibbs energy were further estimated and their implication on dissolution process of benzoin was discussed. [ABSTRACT FROM AUTHOR]

The solid-liquid equilibrium (SLE) of l -norvaline in three different binary solvents, including water + methanol, water + ethanol and water + 2-propanol, was determined by employing a gravimetric method over temperatures from 283.15 K to 318.15 K. It is found that the equilibrium solubility of l -norvaline in the mixed solvents increases with rising temperature at constant solvent composition and decreases with the increasing molar fraction of organic solvents. Moreover, the dissolving capacity of l -norvaline in the three binary solvent mixtures at constant temperature can be ranked as (methanol + water > ethanol + water > 2-propanol + water) in general. Furthermore, a model which can be called polar equation was applied to quantitatively describe the relationship between solubility and polarity of solvent mixtures. The results demonstrate that the increasing polarity of the binary solvents can enhance the solubility of l -norvaline. Besides, the experimental solubility was well correlated by the modified Apelblat equation, λh equation, and NRTL model, with the maximum ARD % values: 1.89%, 3.48%, and 6.42%, respectively. Additionally, the mixing thermodynamic properties of l -norvaline in three binary solvent mixtures were also discussed based on the NRTL model. Results show that the mixing processes of l -norvaline are endothermic and spontaneous. [ABSTRACT FROM AUTHOR]

A compact design of all-optical diode with mode conversion function based on a two-dimensional photonic crystal waveguide and an L1 or L3 cavity is theoretically investigated. The proposed photonic crystal structures comprise a triangular arrangement of air holes embedded in a silicon substrate. Asymmetric light propagation is achieved via the spatial mode match/mismatch in the coupling region. The simulations show that at each cavity’s resonance frequency, the transmission efficiency of the structure with the L1 and L3 cavities reach 79% and 73%, while the corresponding unidirectionalities are 46 and 37 dB, respectively. The functional frequency can be controlled by simply adjusting the radii of specific air holes in the L1 and L3 cavities. The proposed structure can be used as a frequency filter, a beam splitter and has potential applications in all-optical integrated circuits. [ABSTRACT FROM PUBLISHER]

The electrochemical reduction of CO 2 to formic acid or formate is a promising process for addressing technological challenges of transporting and storing energy produced by intermittent renewable energy sources. However, this electrochemical CO 2 conversion process requires high overpotentials to activate CO 2 into “an energetically unfavorable” radical anion intermediate on metal electrodes under the aqueous electrolyte systems. For our present study, we introduce a novel solvent additive such as 1-ethyl-3-methylimidazolium dicyanamide ([Emim][N(CN) 2 ]) ionic liquid into the aqueous solution to increase the electrochemical reduction activity of CO 2 for the formic acid formation, to increase the CO 2 solubility, and to suppress the competitive hydrogen evolution reaction. Cyclic voltammetry is performed in an [Emim][N(CN) 2 ] aqueous solution on a Sn powder electrode to determine the onset potential of CO 2 electrolysis and its electrochemical stability. In addition, CO 2 electrolysis is carried out by chronoamperometry measurements at various fixed potentials and electrolyte concentrations to understand their effects on the faradaic efficiency for the conversion of CO 2 into the formic acid. The maximum faradaic efficiency obtained during electrolysis with a 0.5 M concentration of [Emim][N(CN) 2 ] is 81.9% towards the formation of formic acid at −1.2 V vs. RHE and at the overpotential of 1.08 V. [ABSTRACT FROM AUTHOR]

In this paper, we systematically investigate the electronic structures of uncapped In(Ga)As nanoislands grown on pit-patterned GaAs(001) substrate by solving the Schrödinger equations with effective mass approximation, including composition profile (CP), band offset, strain induced deformation potentials, spin-orbit coupling and piezoelectric effect. For pure InAs epilayer, the shallow pit introduces red-shift to interband transition for all aspect ratios and the heavy-hole is localized by the confinement near the inclined hetero-interfaces in circular pit. For InGaAs alloy epilayer, the uniform CP and equilibrium CPs are considered. Due to the Indium segregation, the reduction of interband transition energy can be observed and the localized profile of heavy-hole moves upward visibly. Moreover, the strain relaxation analysis confirms better strain relaxation for nanoisland grown in shallow pit (tan β = 0.1) compared with same nanoisland grown on flat substrate. The results pave a guideline for designing site-controlled In(Ga)As nanoislands grown in pit for desired applications. [ABSTRACT FROM AUTHOR]

The solubility of boscalid in five pure solvents, including methanol, ethanol, isopropanol, ethyl acetate and n-propyl acetate, and two binary solvent mixtures, including (ethanol + ethyl acetate) and (isopropanol + ethyl acetate), was determined by a gravimetric method with temperatures ranging from (288.15 to 313.15) K. It turns out that the solubility of boscalid increases with the increasing of temperature in all selected solvents. Moreover, it is interesting that the solubility of boscalid in the two binary solvent mixtures performed a maximum effect with the decreasing mole fraction of ethyl acetate at a given temperature. The solubility of boscalid in pure solvents was correlated by the modified Apelblat model and λh model while that in binary solvent mixtures was correlated by the modified Apelblat model, CNIBS/R-K model and Jouyban-Acree model. It is found that all the models could give satisfactory correlation results with less than 3% of all the ARD values. Furthermore, the thermodynamic properties of the mixing processes in all solvents selected were calculated and discussed based on the NRTL model. [ABSTRACT FROM AUTHOR]

The waveguide-integrated reconfigurable power splitting is of great importance for on-chip all-optical connection. Based on the combination of silicon and Sb-based phase change materials (PCMs), a series of ultra-compact reconfigurable power splitters is topologically designed. The footprints of the functional regions are kept less than 1.0λ2. The power splitting ratio between the output channels can be reconfigured through the amorphous and crystalline switching of Sb-based PCMs. We demonstrate Sb 2 Se 3 -based and Sb 2 S 3 -based digital metamaterials for the reconfiguration between power splitting ratio of 5:5 and power splitting ratios of 5:5, 6:4, 7:3, 8:2 and 9:1. The three-dimensional FDTD simulations show that the targeted power splitting ratio can be achieved with acceptable precision. Moreover, the robustness of design is validated by introducing pixel errors. • Reconfigurable power splitter is topologically designed with pixelated Sb-based phase change materials. • The reconfiguration between splitting ratio 5:5 and splitting ratios 5:5, 6:4, 7:3, 8:2 and 9:1 are achieved. • The topology design scheme combines finite element method, density model and MMA. • The footprint of the functional region is less than λ2. [ABSTRACT FROM AUTHOR]

Solubility behavior of d -mannitol ( d -man) in pure water and four water-organic solvents from 288.15 K to 318.15 K at atmospheric pressure was studied by both phase equilibria and molecular modelling methods. A dynamic method was employed to determine the data on equilibrium, both molecular dynamic (MD) simulations and density functional theory (DFT) calculations were carried out to uncover the relationship between intermolecular interactions and solubility behavior. The MD results illustrate that the strength in hydrogen bond of solute-organic solvent captures the solubility ranking of d -man in corresponding mixed solvents, and the radial distribution function (RDF) plots indicate that organic solvents have enhancement effect on the water aggregation in solution which weakened the strong interaction between d -man and water molecules. Both of them suggest that solubility behavior not only depends on solute-solvent interaction, the solvent-solvent interaction also plays a key role in determining it. The solubility was further fitted by the modified Apelblat model, λh model, NRTL model and finally, mixing properties (enthalpy, Gibbs energy and entropy) were discussed, indicating the dissolution process is governed by both enthalpy and entropy of solution. [ABSTRACT FROM AUTHOR]

This meta-analysis aims to compare percutaneous transluminal angioplasty (PTA) to medical treatment (MT) for symptomatic vertebral artery stenosis (SVAS) treatment. We searched PubMed, Springer, Google Scholar, Clinical Trials, Cochrane Central, Chinese National Knowledge Infrastructure, and China Biological Medicine databases. All relevant comparative trials were included. All summary estimates were calculated by random-effect models. Ten comparative trials involving 672 patients were identified. Within 30-day follow-up, there was no significant difference between PTA plus MT and MT alone in vascular death, any stroke, posterior circulation TIA, posterior circulation infarction, and ischemic stroke (all P > 0.05). With a follow-up of more than 1 year, no significant difference was found between PTA plus MT and MT alone in all-cause death (3 vs. 7 %, P = 0.24), vascular death (4 vs. 7 %, P = 0.34), posterior circulation stroke (5 vs. 8 %, P = 0.48), posterior circulation ischemic events (8 vs. 25 %, P = 0.23), posterior circulation TIA (10 vs. 38 %, P = 0.11), posterior circulation infarction (6 vs. 12 %, P = 0.51), vertebral artery occlusion (6 vs. 12 %, P = 0.58), and in secondary long-term events, including any stroke, anterior circulation stroke, hemorrhagic stroke, and myocardial infarction (all P > 0.05), although PTA plus MT could largely reduce the vertebral artery stenosis rate [MD 63.05 %, 95 % CI (32.77-93.34 %), P < 0.01]. Hence, PTA plus MT may be not superior to MT alone for SVAS treatment. Larger randomized trials are needed to verify the optimum therapy for SVAS. [ABSTRACT FROM AUTHOR]

The aim was to determine the effect of electron beam (EB) irradiation on IgE binding capacity of shrimp tropomyosin (TM) at the frozen stage. Following EB irradiation, protein extracts were characterized by sodium dodecyl sulfate–polyacrylamide gel electrophoresis and TM degradation was observed. The degradations were further recognized by IgE from a shrimp-allergic patient by immunoblots. Specific IgE binding results showed that capacity of shrimp extracts and TM initially increased by 10% after irradiation at 3 kGy doses, and then decreased by 20% with irradiation doses increased to 10 kGy. Further inhibition enzyme linked immunosorbent assay results showed that half-maximal inhibitory concentration of shrimp extract treated with 10 kGy doses enhanced to four times as compared with raw shrimp extracts. These results suggest that EB irradiation significantly changes the IgE binding capacity of frozen shrimp at 10 kGy doses by 20% and has the potential to reduce shrimp allergy risk. [ABSTRACT FROM AUTHOR]

In this work, a UV spectroscopic method was used to determine the solubility of troxerutin in eleven mono-solvents and (1,4-dioxane + 2-propanol) mixtures at different temperatures from 288.15 K to 323.15 K. The solubility of troxerutin was positively correlated with temperature in all selected solvents, and it showed a maximum value when the mole fraction of 2-propanol was 0.4 in binary solvent mixtures. The modified Apelblat equation, λh equation, CNIB/R-K model, NRTL model and Jouyban-Acree model were used to correlate the solubility data of troxerutin. It turned out that all the selected thermodynamic models could fit the results well, especially for the modified Apelblat equation with all the ARD values are less than 2%. Furthermore, the thermodynamic properties of troxerutin in different pure and binary solvents were also calculated and are discussed. The results indicated that the dissolution process of troxerutin in the experimental solvents was endothermic. Through analysis of enthalpy-entropy compensation in (1,4-dioxane + 2-propanol) mixtures, a non-linear Δ d H o versus Δ d H o plot was obtained, indicating that the driving mechanism changes with the proportion of 2-propanol in the dissolution process of troxerutin. [ABSTRACT FROM AUTHOR]

In this paper, we systematically investigate the elastic strain relaxation of GeSi nanoislands grown on pit-patterned Si(001) substrate using finite element method. The multi-faceted GeSi nanoislands, including domes, barns and cupolas, inside square pit are modeled based on experimental observations. The impacts of aspect ratio, pit angle and pit filling level are analyzed, based on which a fitting expression is obtained to give a complete description of the strain relaxation. The pit angles corresponding to the best strain relaxation and to the critical point for better relaxation in pit are determined at filling levels (range from 0 to 1) and aspect ratios (range from 0.2 to 0.4). It can be seen that beyond a specific aspect ratio, the relaxation keeps worse than the case of same nanoisland grown on flat substrate, regardless of the pit angle and pit filling level. Moreover, based on the strain energy balance criterion, the conditions to ensure that nanoislands grown inside pit are demonstrated as well. [ABSTRACT FROM AUTHOR]

The solubility of cefmetazole acid in binary solvent mixtures, (methanol + water), (ethanol + water) and (isopropanol + water), was determined by UV spectroscopic method at temperatures from 278.15 to 303.15 K. The solubility of cefmetazole acid increased with the increase of temperature in all solvents. In (methanol + water) co-solvent mixture, the solubility of cefmetazole acid is maximal in neat methanol. In (ethanol + water) and (isopropanol + water) solvent mixtures, the solubility of cefmetazole acid reaches its maximum when the mole fraction of alcohol is 0.5 and 0.4, respectively. The modified Apelblat equation, the CNIBS/R-K model and the Jouyban–Acree model were applied to correlate the experimental solubility of cefmetazole acid. Moreover, the activity coefficients as well as the thermodynamic properties of mixing were calculated and discussed based on the NRTL model and experimental solubility values. [ABSTRACT FROM AUTHOR]

A laser monitoring dynamic method was used to determine the solubility of 4-aminobutyric acid in five mono-solvents of methanol, formamide, 1,2-propanediol, 1,3-propanediol and water, and (methanol + water) binary solvent mixtures over the temperature ranging from 283.15 K to 323.15 K at atmospheric pressure. It turns out to be that in different mono-solvents, the solubility of 4-aminobutyric acid is temperature dependent and increases with the increasing temperature. While in (methanol + water) binary solvent mixtures, the solubility is positively correlated with temperature and negatively correlated with the mole fraction of methanol. The modified Apelblat equation, λh equation and NRTL_Binary model were employed to correlate the solubility data in five mono-solvents. While in (methanol + water) binary solvent mixtures, the NRTL_Ternary model, CNIBS/R-K model and Jouyban-Acree models were applied. It is found that the correlated results are in good agreement with the experimental results. Furthermore, with the activity coefficients considered, solution mixing thermodynamics were calculated and the dissolution process of 4-aminobutyric acid is also discussed. [ABSTRACT FROM AUTHOR]

Background: Extracellular hemoglobin and cell-free heme are toxic breakdown products of hemolyzed erythrocytes. Mammals synthesize the scavenger proteins haptoglobin and hemopexin, which bind extracellular hemoglobin and heme, respectively. Transfusion of packed red blood cells is a lifesaving therapy for patients with hemorrhagic shock. Because erythrocytes undergo progressive deleterious morphological and biochemical changes during storage, transfusion of packed red blood cells that have been stored for prolonged intervals (SRBCs; stored for 35-40 days in humans or 14 days in mice) increases plasma levels of cell-free hemoglobin and heme. Therefore, in patients with hemorrhagic shock, perfusion-sensitive organs such as the kidneys are challenged not only by hypoperfusion but also by the high concentrations of plasma hemoglobin and heme that are associated with the transfusion of SRBCs.Methods: To test whether treatment with exogenous human haptoglobin or hemopexin can ameliorate adverse effects of resuscitation with SRBCs after 2 hours of hemorrhagic shock, mice that received SRBCs were given a coinfusion of haptoglobin, hemopexin, or albumin.Results: Treatment with haptoglobin or hemopexin but not albumin improved the survival rate and attenuated SRBC-induced inflammation. Treatment with haptoglobin retained free hemoglobin in the plasma and prevented SRBC-induced hemoglobinuria and kidney injury. In mice resuscitated with fresh packed red blood cells, treatment with haptoglobin, hemopexin, or albumin did not cause harmful effects.Conclusions: In mice, the adverse effects of transfusion with SRBCs after hemorrhagic shock are ameliorated by treatment with either haptoglobin or hemopexin. Haptoglobin infusion prevents kidney injury associated with high plasma hemoglobin concentrations after resuscitation with SRBCs. Treatment with the naturally occurring human plasma proteins haptoglobin or hemopexin may have beneficial effects in conditions of severe hemolysis after prolonged hypotension. [ABSTRACT FROM AUTHOR]

In this paper, the structural and electronic properties of both bare and alkali metal (AM) atoms adsorbed two-dimensional GeSi alloy sheet (GeSiAS) are investigated by means of first-principles calculations. The band gaps of bare GeSiAS are shown slightly opened at Dirac point with the energy dispersion remain linear due to the spin-orbit coupling effect at all concentrations of Ge atoms. For metal adsorption, AM atoms (including Li, Na and K) prefer to occupy the hexagonal hollow site of GeSiAS and the primary chemical bond between AM adatom and GeSiAS is ionic. The adsorption energy has an increase tendency with the increase of the Ge concentration in supercell. Besides, single-side adsorption of AM atoms introduces band gap at Dirac point, which can be tuned by the Ge concentration and the species of AM atoms. The strong relation between the band gaps and the distribution of Si and Ge atoms inside GeSiAS are also demonstrated. The opened band gaps of AM covered GeSiAS range from 14.8 to 269.1 meV along with the effective masses of electrons ranging from 0.013 to 0.109 m e , indicating the high tunability of band gap as well as high mobility of carriers. These results provide a development in two-dimensional alloys and show potential applications in novel micro/nano-electronic devices. [ABSTRACT FROM AUTHOR]

The bound state in the continuum (BIC) has drawn much attention in electromagnetics due to its infinite lifetime and quality factor. By the method of breaking the symmetry in the metasurface, the optically invisible BIC can be converted into visible quasi-BIC with ultra-high quality factor. However, symmetry-breaking metasurfaces often suffer from polarization sensitivity due to structural or field asymmetry. In this paper, we propose a metasurface consisting of nanodisk tetramer clusters to realize the transformation from BICs to quasi-BICs and support four resonances in the near-infrared range. The in-plane center square defect is introduced to provide symmetry-breaking while C 4 v symmetry is maintained. By performing the multipole decomposition and near-field analysis, these four modes can be demonstrated to be excited by electric quadrupole (EQ), magnetic quadrupole (MQ), magnetic dipole (MD) and toroidal dipole (TD) moments. We demonstrate the full angles polarization-independent characteristic of the metasurface and investigate the robustness by introducing off-center square defects. In addition, we also evaluate the sensing performance of the metasurface as a refractive index sensor. We believe that this work could provide new references for the polarization insensitive metasurface with multiple resonances and help to develop the applications such as biochemical sensing, low-threshold lasing and nonlinear devices. • Metasurface based on symmetry-protected BICs can support high Q-factor multiple Fano resonances. • Polarization independent properties and robustness are confirmed for our proposed metasurface. • The metasurface shows great sensing performance as a refractive index sensor. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ternary Mn 0.5 Cd 0.5 S/CB/CuS hierarchical multiheterojunction system was designed. • Synergetic effect between multifunctional CB and CuS dual cocatalysts discussed. • High H 2 -production rate achieved over composite, 4.79-fold higher than Mn 0.5 Cd 0.5 S. Developing exceptionally robust and cost-effective cocatalysts to suppress charge recombination and reduce the reaction energy barrier remains an enormous challenge for producing high-valued and storable hydrogen fuel from photocatalytic water splitting. Herein, novel Mn 0.5 Cd 0.5 S nanoparticles modified with multifunctional carbon black (CB) nanowires and CuS nanotubes as dual cocatalysts were fabricated via sonochemical loading, and subsequent in-situ deposition routes. In this ternary hierarchical architecture, both CB nanowires and CuS nanotubes can serve as normal electron cocatalysts to markedly promote the hydrogen generation performance by lowering the thermodynamic overpotential for hydrogen evolution. Moreover, due to the high electrical conductivity, the multifunctional CB material can also function as a bridge to effectively capture and transmit the photoexcited electrons from Mn 0.5 Cd 0.5 S to CuS with outstanding electrocatalytic hydrogen evolution activity, thus maximizing the carrier separation and H 2 -evolution reaction kinetics. Interestingly, the cooperative effects between CB and CuS dual cocatalysts are also helpful for improving the oxidation capacity of photoexcited holes by lowering the valence band position of Mn 0.5 Cd 0.5 S, which further accelerates the electron-hole separation. As a result, the constructed Mn 0.5 Cd 0.5 S/CB/CuS hierarchical multiheterojunction catalyst shows the superior hydrogen generation efficiency of 819.9 μmol h−1 and excellent stability under simulated solar light irradiation. [ABSTRACT FROM AUTHOR]

The metal–insulator–metal trapezoidal 2 π phase metasurface is popular for its advantages of easy fabrication, large deflection angle range and a relative broad waveband under normal incidence that parallel to the short side. However, at the wavelength where exists 2nd-order diffraction, there has low 1st-order diffraction conversion efficiency, and the structure does not have the ability of polarization dependent beam manipulation. Our work is to perfect the phase distribution by placing another trapezoid orthogonally next to the original trapezoid, suppress the 0-order and 2nd-order diffractions. The +1st (-1st)-order is mainly controlled by x - (y -) polarized incidence, by rotating the polarization direction of the incident light, we design a tunable beam splitter with a wide range of splitting ratios by numerical simulation. In most wavelengths of 1000–2500 nm, an equal-power beam splitter can be realized. • Anomalous deflected metasurface. • Polarization dependent splitter. • Tunable splitting ratio. • Ultra-broadband and good robustness. [ABSTRACT FROM AUTHOR]

• Amine grafted MCF sorbents were synthesized by using a facile wet grafting method. • The developed sorbents showed high CO 2 uptake of 2.07 mmol/g at 25 °C and 0.15 bar CO 2. • The 3D-interconnected mesoporosity of MCF played a critical role in CO 2 adsorption. A series of amine-functionalized CO 2 sorbents were synthesized by grafting mono- and tri-amine substituted trialkoxysilanes on mesocellular siliceous foam (MCF) via a facile wet grafting method. The effect of amine type, amine loading level, and porous structure of silica on the CO 2 adsorption performance was investigated. MCF silica with a three-dimensional (3D) interconnected porous structure was found to be suitable for preparing amine-grafted sorbents. Tested at 25 °C and 0.15 bar of CO 2 , the mono- and tri-amine grafted MCFs exhibited a fast adsorption rate and excellent CO 2 adsorption capacity of 1.71 mmol/g for mono-amine and 2.07 mmol/g for tri-amine, which was much higher than amine grafted PQ and SBA-15 with a 2D porous structure, and the amine grafted silica sorbents prepared in previous studies. The large pore volume and pore size coupled with superior interconnectivity of MCF enable more surface silanol groups available and accessible for amino silanes, leading to a high amine loading level and excellent amine dispersion on the silica surface, which enhances both the CO 2 adsorption capacity and adsorption rate of the developed sorbents. Cyclic adsorption–desorption tests confirmed the excellent stability of the amine grafted MCF. [ABSTRACT FROM AUTHOR]

[Display omitted] • WS 2 decorated Mn 0.5 Cd 0.5 S/CuInS 2 p-n heterojunction synthesized for H 2 -production. • Multichannel charge-carrier transfer between Mn 0.5 Cd 0.5 S, CuInS 2 and WS 2 discussed. • High H 2 -production rate achieved over composite, 3.98-fold higher than Mn 0.5 Cd 0.5 S. Effective charge separation and sufficient light harvesting are crucial for photocatalytic water splitting into renewable and storable hydrogen energy. Employing WS 2 as cocatalyst and CuInS 2 as p-type semiconductor and photosensitizer, a novel WS 2 /Mn 0.5 Cd 0.5 S/CuInS 2 hierarchical tandem p-n heterostructure was constructed based on the energy band engineering theory. In this tandem p-n heterostructure, Mn 0.5 Cd 0.5 S nanoparticles adhere closely to CuInS 2 nanosheets to form a p-n junction along with the strong and monodirectional inner-built electric field, which can regulate the directional transfer/migration of photoinduced electrons-hole pairs and significantly boost the charge separation. Furthermore, the WS 2 cocatalyst employed in the ternary heterostructure further expedites the spatial charge separation and directional migration of photoexcited electrons, as well as simultaneously provides plentiful reaction active sites to decrease the activation barrier for hydrogen generation reaction. Benefiting from the synergetic cooperation of WS 2 cocatalyst and the p-n junction charge transfer channels, the smartly designed ternary WS 2 /Mn 0.5 Cd 0.5 S/CuInS 2 heterostructure displays the optimal photoactivity toward hydrogen production (681.7 μmol h−1), more 3.98-fold enhancement than individual Mn 0.5 Cd 0.5 S under simulated sunlight irradiation. This research provides a new avenue for constructing multi-hierarchical systems with remarkably boosted charge separation and light-harvesting abilities for high-efficiency solar energy conversion. [ABSTRACT FROM AUTHOR]

This work demonstrates a bottom-up model of fabricating a honeycomb-inspired interface consisting of micro- and nanostructures for improving poly(dimethylsiloxane) (PDMS) hydrophobicity. TiO nanorod arrays and microsized voids were fabricated by a two-step hydrothermal reaction method. First, rutile TiO nanorod arrays were hydrothermally fabricated on the fluorine-doped SnO conductive substrates substrate. Second, microsized TiO voids were synthesized through HCl hydrothermal etching to obtain a honeycomb-inspired interface with tunable size. The size of the etched voids increased from 0.22 ± 0.06 to 8.0 ± 2.8 μm. The interfaces were then transferred on the PDMS surface to improve hydrophobic property. The contact angles of the corresponding positive PDMS replicas reached 140° after etching with the TiO nanorod arrays for 10 h. The size of mastoid structures on the PDMS surfaces was 7.5 μm, which is similar to the size of microstructures on the lotus leaf surface. The fabricated PDMS surface with tunable hydrophobicity properties can be used in the microfluidic channels in the future. [ABSTRACT FROM AUTHOR]

The solubility of pyridoxine hydrochloride in binary solvent mixtures, including (acetone + water), (methanol + water) and (ethanol + water), was measured over temperature range from (278.15 to 313.15) K by a gravimetric method at atmospheric pressure ( P = 0.1 MPa). The solubility increased with increasing temperature in binary solvent mixtures at constant solvent composition. Besides, the dissolving capacity of pyridoxine hydrochloride in the three binary solvent mixtures at constant temperature ranked as (methanol + water > ethanol + water > acetone + water) in general, partly depending on the polarity of the solvents. Additionally, the modified Apelblat equation, van’t Hoff equation, CNIBS/R–K model and Jouyban–Acree model were used to correlate the solubility data in binary mixtures, it turned out that all the selected thermodynamic models could give satisfactory results. Furthermore, the mixing thermodynamic properties of pyridoxine hydrochloride in different binary solvent mixtures were also calculated and discussed. The results indicate that the mixing process of pyridoxine hydrochloride in the selected solvents is exothermic. [ABSTRACT FROM AUTHOR]

A novel nanocomposite photocatalyst NaLuF4:Gd,Yb,Tm@SiO2@Ag@TiO2 was developed for the first time. This composite material has a sandwich structure, including a NaLuF4:Gd,Yb,Tm upconversion nanocrystals (UCNCs) core, a media shell of amorphous SiO2 decorated with Ag nanoparticles, and an outer shell of anatase TiO2. The designed new structure takes advantage of the synergetic effect of UCNCs, Ag nanoparticles and TiO2. The UCNCs absorb near-infrared (NIR) light and transfer energy to TiO2, which extends the light responsive range of TiO2 to the NIR region. Ag nanoparticles not only enhance upconversion luminescence of the UCNCs but also enhance light harvesting and improve charge separation of TiO2. The results of photocatalytic applications show that the as-prepared catalyst has high photocatalytic activity. This study provides new insights into the fabrication of TiO2-based nanocomposite photocatalysts with high catalytic efficiency through effective integration of upconversion material, noble metal and TiO2 into a hetero-composite nanostructure. [ABSTRACT FROM AUTHOR]

We demonstrate a facile approach to synthesize shape-controlled anatase titania with tailored facets via the employment of 3-aminopropyltrimethoxysilane (APTMS) as shape-tunable and capping agent. The as-synthesized anatase TiO 2 nanorods was highly crystalline and exposed with {001} and {100} facets. The LIBs based on these highly crystalline TiO 2 nanorods with tailored facets reveals significant improvement in high-rate capacity and cycling performance. More importantly, this methodology enable the industrial application of anatase titania as anode materials for LIBs without high temperature annealing process. [ABSTRACT FROM AUTHOR]

• Compact device footprint. • Based on the emerging chalcogenide compound Ge 2 Sb 2 Se 4 Te 1. • Excellent performances with low insertion loss and high switching depth. • Greatly competitive to the state-of-the-art counterparts. Chalcogenide compound Ge 2 Sb 2 Se 4 Te 1 (GSST), an emerging phase change material, features drastic optical property contrast between the amorphous and crystalline states. In this paper, a compact and nonvolatile polarization-rotating optical switch is proposed and demonstrated numerically assisted by a L-shaped GSST waveguide, covering the telecom C- band. The switch exhibits greatly competitive performances with a good trade-off for a low insertion loss below 0.33 dB, a high switching depth (SD) above 34.2 dB, a compact device footprint (length = 4.28 μm) and an operating bandwidth over 100 nm. The device performances with the intermediate states between amorphous and crystalline of GSST are investigated as well. Furthermore, the results show that the optical switch exhibits a satisfactory robustness with SD > 33.8 dB within the ± 20-nm variations for both etching width and height. This work can provide a viable scheme to achieve the functionality of combining polarization rotation and switching, which will simplify the system architecture and improve the integration of polarization diversity circuits for optical routing on chip. [ABSTRACT FROM AUTHOR]

Increasing evidence highlighted the metabolic associations between host and gut microbiota during infection. However, how host–gut microbiota metabolic partnership response to carbapenem-resistant Escherichia coli (CRE) infection has yet to be elucidated. In this study, we subjected the mice to a single intraperitoneal injection of CRE and studied the alterations of the small molecule metabolites derived from host-microbial co-metabolism, as well as the gut microbiome in mice, at 24 h after infection by a two-level strategy. A panel of metabolites in feces and serum, were found to alter significantly in the CRE group, including 26 joint metabolites between them. Meanwhile, the relative abundance of 14 OTUs in Firmicutes (10 OTU), Bacteroidetes (2 OTU), Actinomycetes (1 OTU), and Proteobacteria (1 OTU) were observed to change after infection. Association analyses demonstrated that 9 OTUs including six in the Firmicutes phylum, two in the Bacteroidetes phylum, and one in the Actinomycetes phylum, were associated with the changes of 49 fecal metabolites and 42 serum metabolites. The study of gut microbiota-host metabolic interactions in the early stage of the infection is expected to provide novel diagnostic methods and therapeutic strategies for CRE infection, bring innovative solutions to resolve the current challenge. [Display omitted] • Serum and fecal metabolomic profile were significantly changed in mice suffering from acute CRE infection. • Alterations in the fecal microbiota were associated with the metabolic signatures in response to acute CRE. • Pathogen-gut microbiota-host metabolic interactions provide novel diagnostic and therapeutic strategies for CRE infection. [ABSTRACT FROM AUTHOR]

Oil shale pyrolysis is normally extremely complicated because many reactive processes simultaneously occur and different products are therefore continuously generated and serve as a new reactant, as a multi-stage processes with competing or parallel reactions. To probe deeply into the pyrolysis kinetics of Huadian oil shale, we have employed multi-stage parallel reaction model and bi-Gaussian distribution method to fit the non-isothermal thermogravimetric data. Friedman, Flynn–Wall–Ozawa, and Kissinger–Akahira–Sunose methods were utilized to estimate activation energy, and two master plots methods were introduced to establish kinetic models. Two reactions were involved in devolatilization of organic matter in oil shale, and the Reaction II was a principal process of Stage II and dominated kinetic property of overall Stage II. The heating rate had some impact on the pyrolysis process but exerted little influence on kinetic parameters. The comparison of these results indicated the inherent property and thermal stability of oil shale pyrolysis. [ABSTRACT FROM AUTHOR]

Purpose. The association between multiple sclerosis (MS) and fracture risk has been reported, but results of previous studies remain controversial and ambiguous. To assess the association between MS and fracture risk, a meta-analysis was performed. Method. Based on comprehensive searches of the PubMed, Embase, and Web of Science, we identified outcome data from all articles estimating the association between MS and fracture risk. The pooled risk ratios (RRs) with 95% confidence intervals (CIs) were calculated. Results. A significant association between MS and fracture risk was found. This result remained statistically significant when the adjusted RRs were combined. Subgroup analysis stratified by the site of fracture suggested significant associations between MS and tibia fracture risk, femur fracture risk, hip fracture risk, pelvis fracture risk, vertebrae fracture risk, and humerus fracture risk. In the subgroup analysis by gender, female MS patients had increased fracture risk. When stratified by history of drug use, use of antidepressants, hypnotics/anxiolytics, anticonvulsants, and glucocorticoids increased the risk of fracture risk in MS patients. Conclusions. This meta-analysis demonstrated that MS was significantly associated with fracture risk. [ABSTRACT FROM AUTHOR]

The stress–strain relationships of low-buckle silicene are investigated in the framework of the density functional theory for equiaxial tensile strain and uniaxial tensile strain along armchair and zigzag directions. The ideal strengths for equiaxial tension and armchair uniaxial tensions are 7.59 N/m and 6.76 N/m, respectively. For zigzag uniaxial tension, there exists two ideal strengths (5.26 N/m and 5.29 N/m) due to the phase transition of silicene from original low-buckle structure to true planar structure. The phonon dispersions of silicene under three types of tensions are calculated using the finite differences method to examine stability conditions. The results show that failure mechanisms of silicene under armchair and zigzag uniaxial tensions are elastic instability (phonon instability occurs behind the elastic instability). We find that phonon instabilities occur near the center of the Brillouin zone and phonon soft modes for armchair and zigzag uniaxial tensions are longitudinal acoustical (LA) modes along the pulling direction like graphene. The failure mechanism of silicene under equiaxial tension is only attributed to elastic instability unlike graphene. The phonon instability is dictated by out-of-plane acoustical (ZA) mode rather than K 1 mode in graphene. Phonon also becomes instable in the planar structure of silicene transformed under zigzag uniaxial tension. Dependence of electronic properties of silicene on the uniaxial tensions is investigated. Uniaxial tensions along armchair and zigzag directions cannot open a gap in silicene. But it is available to tune the gaps induced by spin–orbital coupling through these two types of tensions. [ABSTRACT FROM AUTHOR]

Atomic structures and nonlinear properties of single layer graphene (SLG), bilayer graphene (BLG), single layer silicene (SLS), and bilayer silicene (BLS) under equiaxial tension and uniaxial tensions along armchair and zigzag directions have been investigated comparatively using first-principles calculations. First, we have calculated the dependences of atomic structures (bond length, interlayer distance, and buckling height) of BLG and BLS on strain under three types of tensions. There exists the weak Van der Waals interaction between two layers of BLG and the interlayer distance is not variable with strain for three types of tensions. However, the interlayer of BLS is the covalent bond interaction, and the distance decreases with the increasing strain for three types of tensions. The continuum description of elastic response is formulated by expanding the elastic strain energy density in a Taylor series in strain truncated after the third-order term. The in-plane second- and third-order elastic constants of BLG and BLS have been obtained by fitting to the strain energy density versus Lagrangian strain relationships. The results show the in-plane stiffnesses of BLG and BLS become slightly larger than those of their single layer counterparts. In spite of the interlayer Si–Si covalent bond between two layers of BLS, its stiffness is still much less than BLG and SLG. Poisson’s ratios of BLG and BLS basically maintain unchanged compared to their single layer counterparts. [ABSTRACT FROM AUTHOR]

Highlights: [•] A topochemical reaction method was studied for shale oil and gas extraction. [•] The mechanism of topochemical reaction was proposed and well demonstrated. [•] The oxygen is a crucial factor for this chemical heat-enhanced procedure. [•] There were five distinct reaction identified in entire process. [ABSTRACT FROM AUTHOR]

Abstract: The concentration of tetrabutyl titanate (TBT) and H2O influence on the reaction kinetics of TBT and acetic acid (AcOH) solvothermal system are systematically studied. It is found that TBT and H2O have greatly accelerated the hydrolysis–condensation process of the TBT–AcOH system. By adjusting those concentrations with reaction time, we prepare five kinds of sub-micron/micron precursors, which are hierarchical structures consisting of different primary building blocks. The morphology of these precursors varies from noninterlaced structures composed of flower-like microsphere and ellipsoid sphere to interlaced structures composed of flower-like microsphere interlaced nanofibers, ellipsoid spheres interlaced flower-like microsphere and nanoparticles interlaced flower-like microsphere. These interlaced structures are synthesized for the first time and are not ordinary mixtures of the noninterlaced structures. After heat treatment, these precursors are transformed to anatase TiO2. Shape-dependent photovoltaic performances of dye-sensitized solar cells (DSSCs) are also discussed. DSSCs based on these hierarchical sub-micron/micron TiO2 show 7.3%–7.9% energy conversion efficiencies, and the devices based on interlaced structures have higher efficiencies (7.4%–7.9%) than those of the devices based on noninterlaced structures (7.3%–7.6%). [Copyright &y& Elsevier]

Abstract: A facile and reliable method is applied to prepare the electrolyte based on hydroquinone (HQ)/benzoquinone (BQ) redox couple for dye-sensitized solar cells (DSSCs) in open environment by adding moderate amount of acetic acid (HAc), and the best conversion efficiency (η) of 5.82% is achieved under 100mWcm−2 (AM 1.5G) illumination. Electrochemistry properties of DSSCs using such redox couple are measured and the results show a higher current and better charge transfer in contrast to I −/I 3 −. And a slightly higher efficiency of 5.88% is obtained when HQ and BQ are symmetrically substituted by two methyls. With advantages of high efficiency, compatible with the most common dye N719 and easily tuned by facile structural modification, the redox shuttle employing HQ/BQ via HAc treatment is very promising to be employed in efficient DSSCs. [Copyright &y& Elsevier]

Conventional metasurfaces cannot adjust the electromagnetic responses once the structures are determined. In this paper, we numerically demonstrate a thermally switchable bifunctional metasurface based on the phase change material vanadium dioxide (VO 2) applied to the mid-infrared band. The dual-layer ring resonator consists of an Ag split ring and a VO 2 ring, which can achieve ultra-broadband polarization conversion and perfect absorption through the insulator-to-metal phase transition of VO 2. When VO 2 is in the insulating state, the designed metasurface acts as polarization converter with polarization conversion ratio of over 95% in the wavelength range of 2500 nm to 3500 nm. When VO 2 is in the metallic state, the metasurface behaves as perfect absorber with over 90% absorptivity in the region from 2900 nm to 3700 nm. And the operating bandwidths of the two functions are highly overlapped. The ultra-broadband polarization conversion properties are mainly derived from the closed multiple electric and magnetic resonances. Single localized magnetic resonance results in a flat absorption spectrum. The proposed metasurface may provide new ideas for the design of tunable integrated optical devices. • Switching of polarization conversion and perfect absorption. • Highly overlapping operating bandwidths. • Easy to switch by changing temperature. • High efficiency and great robustness. [ABSTRACT FROM AUTHOR]

Excessive phosphorus (P) inputs from manure and synthetic fertilizers leads to high environmental risk in greenhouse vegetable production systems. In the current study, we determined whether a system of P fertilization that attempts to achieve a zero-P surplus balances agronomic, economic, and environmental concerns. A field experiment was conducted to evaluate the potential of integrated inorganic and organic nutrient management to provide both high yield and minimal environmental risk in a typical region of greenhouse vegetable production in China. Three treatments were compared: farmers' practice (FP), current recommended nutrient management (CRNM), and designed balanced nutrient management (DBNM, with P input optimized based on crop demand). The results indicated that in the greenhouse cucumber production system, the seasonal P surplus of FP was as high as 410 kg P ha−1; this increased the movement of P to the subsoil, causing a high risk of P loss, i.e., a P index >9, and a high eutrophication potential (87.4 kg PO 4 -eq ha−1). Compared with FP, CRNM (which had a 76% lower P fertilizer input) significantly reduced the P surplus, the risk of P loss, and the eutrophication potential, and increased yield incomes and net ecosystem economic benefits by 18.0% and 31.8%, respectively. Compared with CRNM, DBNM significantly reduced the P surplus by 84.5% and the environmental damage cost by 19.0%, while increased the input cost by 23.0%. Therefore, the DBNM strategy is recommended in greenhouse vegetable production to reduce the P surplus and environmental costs, and to obtain high yield and economic benefits. [Display omitted] • The nutrient input could be optimized to ensure high yield with less P input in a plastic shed system. • The CRNM and DBNM reduced soil available P and CaCl 2 –P concentration. • The P index and eutrophication potential was lower in CRNM and DBNM system than in FP. • DBNM further decreased environmental damage costs by 19% compared with CRNM. [ABSTRACT FROM AUTHOR]

In this paper, we present a general design scheme for waveguide-integrated demultiplexing devices based on intelligent topology search method combining density model and gradient-based method of moving asymptotes. 2D finite element method is adopted to simulate and evaluate the performance of demultiplexers with quasi-3D configuration by setting equivalent refractive index of silicon. The obtained pixelated digital metamaterials individually fulfill functionalities including 1550nm/1310nm and 1500nm/1600nm wavelength demultiplexing, TE0/TE1 mode demultiplexing at 1550 nm, and TE0/TM0 polarization demultiplexing at 1550 nm. The footprint of the functional region is as small as 1.55 μm × 1.55 μm. To validate our designs with SOI configuration, 3D models are simulated by finite difference time domain. Comparable and satisfactory performances of the target functionalities are demonstrated. For all four demultiplexers, the worst transmission efficiency is 44.5% of TE0 in polarization demultiplexing, the worst contrast ratio is 14.1 dB of TE1 in mode demultiplexing and the worst crosstalk is −15.1 dB of TE0 in mode demultiplexing. Within an ultra-compact footprint, this design scheme can efficiently enable the device to separate or route photons based on specific dimension, such as wavelength, mode and polarization. • Digital metamaterials are designed for wavelength, mode and polarization demultiplexing. • The inverse design scheme combines DM and MMA method, which needs only 200 iterations to search for a design. • The functional region of the demultiplexer occupies only λ2. • The performances of the four ultra-compact demultiplexers are comparable and satisfactory. [ABSTRACT FROM AUTHOR]

Based on density functional theory, we theoretically investigate the electronic structures of free-standing armchair Janus MoSSe nanoribbons (A-MoSSeNR) with width up to 25.5 nm. The equilibrium structures of nanoribbons with spontaneous curling are obtained by energy minimization in molecular dynamics (MD). The curvature is 0.178 nm−1 regardless of nanoribbon width. Both finite element method and analytical solution based on continuum theory provide qualitatively consistent results for the curling behavior, reflecting that relaxation of intrinsic strain induced by the atomic asymmetry acts as the driving force. The non-edge bandgap of curled A-MoSSeNR reduces faster with the increase of width compared with planar nanoribbons. It can be observed that the real-space wave function at the non-edge VBM is localized in the central region of the curled nanoribbon. When the curvature is larger than 1.0 nm−1, both edge bandgap and non-edge bandgap shrink with the further increase of curvature. Moreover, we explore the spontaneous curling and consequent sewing process of nanoribbon to form nanotube (Z-MoSSeNT) by MD simulations. The spontaneously formed Z-MoSSeNT with 5.6 nm radius possesses the lowest energy. When radius is smaller than 0.9 nm, the bandgap of Z-MoSSeNT drops rapidly as the radius decreases. We expect the theoretical results can help build the foundation for novel nanoscale devices based on Janus TMD nanoribbons. [ABSTRACT FROM AUTHOR]

• This case-control study assessed the psychological status of COVID-19 patients. • It showed that COVID-19 patients had higher prevalence of mental problems, such as anxiety, depression, suicidal ideation, and insomnia compared to controls. • Our findings highlighted the urgent need for psychological assistance for COVID-19 patients. The coronavirus disease 2019 (COVID-19) has caused widespread panic due to its highly infectious and pandemic transmission. We aimed to evaluate the psychological impact of the COVID-19 outbreak on infected subjects in China. This case-control, survey-based study assessed the psychological status of COVID-19 patients and non-infected controls from February 10 to March 18, 2020, in China. Sex, age, education years, marital status, jobs, annual household income, living status, and geographic origin were matched between the two groups. The main outcome measures included anxiety, depression, insomnia, help-seeking behaviors, and treatment for mental problems. A total of 326 patients and 1304 (1:4 ratio) matched non-infected controls were enrolled. Compared with controls, patients had higher scores on the Beck Anxiety Inventory (BAI), Patient Health Questionnaire-9 (PHQ-9), and Insomnia Severity Index (ISI) (all p <0.01). Patients had higher rate of any mental problems (62.6% vs 42.5%, p <0.01), anxiety (27.3% vs 12.2%, p <0.01), depression (26.7% vs 14.6%, p <0.01), suicidal ideation (16.0% vs 10.7%, p <0.01), and insomnia (57.7% vs 36.7%, p <0.01). Among the subjects with mental problems, the proportion of seeking help (15.2% vs 6.9%, p <0.01) and receiving treatment (11.3% vs 4.3%, p <0.01) was higher in patients than controls. Our study showed a higher prevalence of mental problems in COVID-19 patients compared to controls, suggesting a great psychological impact of COVID-19 infection. Our findings highlighted the urgent need for psychological assistance for COVID-19 patients. [ABSTRACT FROM AUTHOR]

A two-dimensional photonic crystal waveguide is optimized for ultraslow light propagation. By employing geometry projection method optimization, a flat band photonic crystal waveguide is achieved with the minimum group index around 2335, which is much larger than those reported before. The investigation of the transient propagation of the Gaussian pulse in the waveguide indicated that low group velocity dispersion can cause a small expansion of the pulse. The stability analysis indicates that slightly numerical and angular deviation in fabrication can influence the minimum group index of the waveguide, but the ultraslow light property can still be maintained. The theory simulation in our work can provide some useful guidance for further ultraslow light research. [ABSTRACT FROM AUTHOR]

Abstract: Trace amount chromium-doped (Cr-doped) TiO2 is prepared by hydrothermal method for dye-sensitized solar cells (DSSCs). The effect on photovoltaic performance of the cells is investigated via control of the concentrations of Cr doped in TiO2. Rutile phase increases when Cr is incorporated into TiO2 while the property of electron transport in photoelectrodes is improved by doping Cr which results in a reduced resistance (R ct) of the electron transport within mesoporous layer and an improved electron lifetime. The regularity of R ct and electron lifetime is reversed when the level of doped Cr exceeds 50 ppm. On the other hand, owing to the doping effect of Cr, the short-circuit photocurrent density (J sc) of DSSCs is remarkably enhanced and reaches maximum. Consequently, the overall energy conversion efficiency enhances to 6.35% with Cr-doped TiO2 of 50 ppm, which is 14.62% higher than that with undoped TiO2. In general, compared with undoped TiO2, Cr-doped TiO2 is a better photoanode material and a more promising alternative for high efficient DSSCs. [Copyright &y& Elsevier]

Abstract: Highly porous carbon/SnO2/TiO2 nanocomposite films that can be used as counter electrodes in dye-sensitized solar cells (DSSCs) are fabricated by coating a homogeneous and viscous carbon paste on F-doped tin oxide conducting glass. The carbon paste is prepared by ball-milling a mixture of carbon, SnO2 powder and TiO2 hydrosol in an organic solution. The composite films are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscope, Brunauer–Emmett–Teller and Form Talysruf Profiler. The results indicate that the photovoltaic performances of the composite DSSCs are influenced by the content of SnO2. When the content is increased to 30%, SnO2 not only acts as “framework” to strengthen the mechanical stability of the composite film but also increases the specific surface area and root-mean-square roughness, which improve fill factor and short-circuit current, finally increasing power conversion efficiency from 5.12% to 6.15%. Cyclic voltammetry analysis and electronic impedance spectroscopy of the optimum composite film display higher catalytic activity for I3 −/I− redox reactions and much lower charge-transfer resistance compared with Pt, respectively. Dye-sensitized solar cells based on this nanocomposite counter electrode achieve efficiency as high as 6.15% which is comparable to that of the cells using sputtering Pt as counter electrode at similar conditions. [Copyright &y& Elsevier]

Abstract: The structural and electronic properties of neutral and negatively charged Ga12X (X=C, Si, Ge, Sn, and Pb) clusters are calculated by the first-principles method. The results show that the most stable symmetry depends on the doped atom rather than the geometry structure. However, the geometry symmetry plays an important role in calculating the energy gap. In addition, in the anionic clusters, the added electron would reduce the energy gap by about 0.4eV. As for the density of states (DOS), clusters with the same symmetry show a similar trend of DOS. The major impact on DOS by adding an electron is the occurrence of relative energy shift. [Copyright &y& Elsevier]

Abstract: A finite element model is proposed to quantitatively predict the critical condition for a nitride quantum dot to bend threading dislocation to interfacial misfit dislocation. The energy balance approach adopted is based on the elastic residual strain energy and non-elastic dislocation core energy. We find that the critical misfit, beyond which the inclination of threading dislocation is energetically favorable, depends strongly on the shape, size and aspect ratio. The results provide guidelines for the design of quantum dot dislocation filter. [Copyright &y& Elsevier]

Abstract: Binary Al2O3/SiO2-coated rutile TiO2 composites were prepared by a liquid-phase deposition method starting from Na2SiO3·9H2O and NaAlO2. The chemical structure and morphology of binary Al2O3/SiO2 coating layers were investigated by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, TG–DSC, Zeta potential, powder X-ray diffraction, and transmission electron microscopy techniques. Binary Al2O3/SiO2 coating layers both in amorphous phase were formed at TiO2 surfaces. The silica coating layers were anchored at TiO2 surfaces via Si–O–Ti bonds and the alumina coating layers were probably anchored at the SiO2-coated TiO2 surfaces via Al–O–Si bonds. The formation of continuous and dense binary Al2O3/SiO2 coating layers depended on the pH value of reaction solution and the alumina loading. The binary Al2O3/SiO2-coated TiO2 composites had a high dispersibility in water. The whiteness and brightness of the binary Al2O3/SiO2-coated TiO2 composites were higher than those of the naked rutile TiO2 and the SiO2-coated TiO2 samples. The relative light scattering index was found to depend on the composition of coating layers. [ABSTRACT FROM AUTHOR]