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Nanorods assembled 3D microspheres of TiO2/MnO2 were prepared via a simple one-pot hydrothermal approach. The resultant composite material exhibited remarkable electrocatalytic activity for hydrogen peroxide (H2O2) in comparison to each single component. The electrochemical sensor constructed with TiO2/MnO2 exhibited a linear relationship within the range 0.0001–5.6 mmol·L−1 for H2O2. The limit of detection (LOD) and sensitivity for H2O2 were 0.03 µmol·L−1 (S/N = 3) and 316.6 µA (mmol·L−1)−1 cm−2. Moreover, this sensor can be employed to detect trace amount of H2O2 in serum and urine samples successfully, supporting an insight and strategy for a more sensitive electrochemical sensor. [ABSTRACT FROM AUTHOR]

The effect of varying amounts (1.0–5.0 wt %) of TiO 2 as an additive on the interfacial behavior between the MgAl 2 O 4 crucible materials and molten K417G superalloys during the vacuum induction melting has been characterized. Experimental results indicate that the phases of the TiO 2 -doped MgAl 2 O 4 materials were identified as MgAl 2 O 4 and minor amounts of MgTiO 3 after sintering at 1680°C for 1 h. When the TiO 2 -doped MgAl 2 O 4 crucibles were in contact with K417G melt, a reaction layer of MgTiO 3 was formed at the inner wall of the crucible. Moreover, some Al3+ and O2- were expelled toward the alloy side from MgTiO 3 near the interface to form Al 2 O 3 phases, and even form a continuous aluminum oxide layer in the 5 wt %TiO 2 -doped crucible after the melting experiment. Furthermore, only MC carbide with MgAl 2 O 4 as the core (MgAl 2 O 4 -(Ti, Mo)C hybrid-type) in the K417G alloy after the melting experiment can be observed, indicating that physical erosion predominates. [ABSTRACT FROM AUTHOR]

The loquat (Eriobotrya japonica L.) is a special evergreen tree, and its fruit is of high medical and health value as well as having stable market demand around the world. In recent years, research on the accumulation of nutrients in loquat fruit, such as carotenoids, flavonoids, and terpenoids, has become a hotspot. The SBP-box gene family encodes transcription factors involved in plant growth and development. However, there has been no report on the SBP-box gene family in the loquat genome and their functions in carotenoid biosynthesis and fruit ripening. In this study, we identified 28 EjSBP genes in the loquat genome, which were unevenly distributed on 12 chromosomes. We also systematically investigated the phylogenetic relationship, collinearity, gene structure, conserved motifs, and cis-elements of EjSBP proteins. Most EjSBP genes showed high expression in the root, stem, leaf, and inflorescence, while only five EjSBP genes were highly expressed in the fruit. Gene expression analysis revealed eight differentially expressed EjSBP genes between yellow- and white-fleshed fruits, suggesting that the EjSBP genes play important roles in loquat fruit development at the breaker stage. Notably, EjSBP01 and EjSBP19 exhibited completely opposite expression patterns between white- and yellow-fleshed fruits during fruit development, and showed a close relationship with SlCnr involved in carotenoid biosynthesis and fruit ripening, indicating that these two genes may participate in the synthesis and accumulation of carotenoids in loquat fruit. In summary, this study provides comprehensive information about the SBP-box gene family in the loquat, and identified two EjSBP genes as candidates involved in carotenoid synthesis and accumulation during loquat fruit development. [ABSTRACT FROM AUTHOR]

SpyTag and SpyCatcher can rapidly conjugate covalently to form an irreversible covalent bond. Fusing SpyTag and SpyCatcher to the termini of a protein of interest enables the generation of SpyRing structure, which is often helpful for the stability of protein. In this paper, green fluorescent protein (GFP), L -phenylserine aldolase (LPA) and SRGFP, SRLPA (their SpyRing cyclized form) were covalently bound to glyoxyl-agarose (Gx) beads to prepare immobilized enzymes (Gx-GFP, Gx-LPA, Gx-SRGFP and Gx-SRLPA) with different protein loadings, and the effects of the SpyRing structure on solid-phase refolding were investigated. When the immobilized enzyme was inactivated in high concentrations of N, N-dimethylformamide (DMF) and 9 M guanidine hydrochloride, then reactivated with refolding buffer, the results showed that proteins with the SpyRing structure had a higher renaturation yield than their wild-type counterparts in all three replication cycles. The highest renaturation yields of Gx-SRGFP and Gx-SRLPA were over 90 % and 70 % respectively, which were approximately 15 % and 30 % higher than those of Gx-GFP and Gx-LPA. It suggests that the introduction of the SpyRing structure facilitates the reactivation of immobilized biocatalysts and provides a reference for the regeneration and recycling of industrial biocatalysts. [Display omitted] • The renaturation yield of cyclized proteins was significantly higher than wild-type proteins. • The solid-phase refolding of immobilisates of SpyRing cyclized proteins were studied. • Renaturation yield of immobilisates was improved by using SpyTag/SpyCatcher system. • Reactivation of the immobilisates with high protein loadings was achieved. [ABSTRACT FROM AUTHOR]

Background: Stress hyperglycemia ratio (SHR) is significantly related to adverse cardiovascular clinical outcomes and increased in-hospital mortality. However, the relationship between SHR and coronary artery disease (CAD) severity has hitherto not been reported. This study sought to clarify the relationship between the SHR and CAD severity of individuals with different glucose metabolic statuses. Methods: A retrospective analysis was performed on 987 patients who underwent coronary angiography (CAG) from October 2020 to May 2022. Based on CAG results, patients were divided into single-vessel CAD and multi-vessel CAD groups. All subjects were stratified into three groups according to the tertiles of the SHR (T1 group: SHR < 0.930; T2 group: 0.930 ≤ SHR < 1.154; T3 group: 1.154 ≤ SHR). Moreover, according to glucose metabolism status, study subjects were divided into normal glucose regulation (NGR), pre-diabetes mellitus (pre-DM) and diabetes mellitus (DM) groups. Finally, the correlation between SHR and CAD severity was analyzed by logistic regression analysis and receiver operating characteristic (ROC) curve. Results: The results showed significantly higher SHR in the multi-vessel CAD group than in the single-vessel group. Logistic regression analysis showed that SHR was an independent risk factor for multi-vessel CAD when used as a continuous variable (OR, 4.047; 95% CI 2.137–7.663; P < 0.001). After adjusting for risk factors, the risk of multi-vessel CAD in the T2 and T3 groups was 1.939-fold (95% CI 1.341–2.804; P < 0.001) and 1.860-fold (95% CI 1.272–2.719; P = 0.001) higher than in the T1 group, respectively. The area under the curve (AUC) of ROC plots was 0.613 for SHR. In addition, SHR was significantly correlated with an increased risk of multi-vessel CAD in the pre-DM and DM groups. Conclusions: Our study indicated that SHR was significantly correlated with the risk of multi-vessel CAD and predicted CAD severity, especially in pre-DM and DM patients. [ABSTRACT FROM AUTHOR]

An efficient method for simultaneous extraction, purification and determination of six lignans in Schisandra chinensis Baill was developed by employing matrix solid-phase dispersion (MSPD) extraction followed by HPLC-UV determination analysis. Several sorbent and desorption solvent that affected the extraction yield of lignans were investigated; neutral alumina and absolute ethanol were selected as the best dispersing material and desorption agent, respectively. Other extraction conditions for MSPD were optimized as follows: 1:2 of S. chinensis raw material to neutral aluminum oxide mass ratio, 1:30 (g/mL) of sample to absolute ethanol, 2.5 h of desorption time and 50°C of desorption temperature. Under the above conditions, the total extraction yield for six lignans have reached (16.99 ± 0.33) x 103 mg/kg with a higher content of 6.88 ± 0.25% in the extracts. Comparative studies were explored by conducting other six extraction approaches including Soxhlet extraction, heat reflux extraction, smashing tissue extraction, microwave-assisted extraction, ultrasonic-assisted extraction and ultrasonic-microwave synergistic extraction. Results showed MSPD technique not only improved the extraction yield, but also improved the purity of lignans, it can be generalized to more extraction of natural compounds. In addition, the validated HPLC-UV method had been successfully applied to analysis of lignans from 10 real S. chinensis samples. [ABSTRACT FROM AUTHOR]

During recent decades numerous academics have examined the tourism-led economic growth (TLEG) hypothesis, and a large number of related empirical studies have been published in the tourism literature. However, the research designs for many of these studies have not satisfactorily addressed the theoretical foundation that underpins the TLEG hypothesis. Their empirical analyses may therefore lead to unreliable or even misleading conclusions. This study critically evaluates these TLEG studies from both theoretical and empirical perspectives and provides recommendations for future TLEG studies. [ABSTRACT FROM AUTHOR]

In the present paper, we construct a new class of multivariate risk statistics, which are multivariate shortfall risk statistics. First, we propose the multivariate shortfall risk statistics. Then their basic properties are investigated, and the dual representation results are studied. Furthermore, their coherency is also characterized by means of the corresponding loss function. Finally, examples are given to illustrate the proposed multivariate shortfall risk statistics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Near-spherical ZnO/N-rGO nanocomposite was prepared by a facile hydrothermal method. • Systematic study of electrochemical sensing property of ns-ZnO/N-rGO for nitrite. • Sensor was used for detection of nitrite in ham sausage, pickle and tap water. • The electrochemical sensing mechanism of ns-ZnO/N-rGO for nitrite was explored. A hierarchical near-spherical ZnO (ns-ZnO)/Nitrogen-doped reduced graphene oxide (N-rGO) nanocomposite was synthesized via a facile hydro/solvo-thermal route. Then, a non-enzymatic nitrite electrochemical sensor (ns-ZnO/N-rGO/GCE) was obtained by modifying glassy carbon electrode (GCE) with the prepared nanocomposite. More adsorption sites and electro-catalytic active sites were provided at the electrode interface thanks to the formation of hierarchical structure, making the fabricated GCE possess a remarkable amperometric sensing property for nitrite. The limit of detection (LOD) was as low as 0.08 μM, and the detection range was as broad as 0.037 μM–5.9 mM. Furthermore, this sensor showed satisfactory recovery for nitrite in genuine samples including ham sausage, pickle and tap water, suggesting the potential practical application performance of ns-ZnO/N-rGO/GCE in the fields of food analysis and environmental monitoring. [ABSTRACT FROM AUTHOR]

Ammonium (NH4+) is toxic to root growth in most plants already at moderate levels of supply, but mechanisms of root growth tolerance to NH4+ remain poorly understood. Here, we report that high levels of NH4+ induce nitric oxide (NO) accumulation, while inhibiting potassium (K+) acquisition via SNO1 (sensitive to nitric oxide 1)/SOS4 (salt overly sensitive 4), leading to the arrest of primary root growth. High levels of NH4+ also stimulated the accumulation of GSNOR (S -nitrosoglutathione reductase) in roots. GSNOR overexpression improved root tolerance to NH4+. Loss of GSNOR further induced NO accumulation, increased SNO1/SOS4 activity, and reduced K+ levels in root tissue, enhancing root growth sensitivity to NH4+. Moreover, the GSNOR-like gene, OsGSNOR , is also required for NH4+ tolerance in rice. Immunoblotting showed that the NH4+-induced GSNOR protein accumulation was abolished in the VTC1- (vitamin C1) defective mutant vtc1-1 , which is hypersensititive to NH4+ toxicity. GSNOR overexpression enhanced vtc1-1 root tolerance to NH4+. Our findings suggest that induction of GSNOR increases NH4+ tolerance in Arabidopsis roots by counteracting NO-mediated suppression of tissue K+, which depends on VTC1 function. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis of hierarchical hollow pompon-like α-MnO 2 /rutile TiO 2 microspheres. • Rutile phase of TiO 2 can be gained under this mild experiment condition. • The effect of n Ti /n Mn and reaction time on the microstructure was studied. • Bulid a sensor to detect trace amount of DA in serum and urine. • Investigation of catalytic mechanisms of α-MnO 2 /rutile TiO 2 /GCE for DA. Composite materials are receiving growing interest due to their excellent electrochemical properties. Here, through a simple hydrothermal technique, a 3D porous pompon-like α-MnO 2 /rutile TiO 2 (n Ti /n Mn = 0.075) composite with superior electrocatalytic activity is successfully endowed, in which the detection limit can be low as 3.5 nmol·L−1 (S/N = 3) for dopamine. It is found that the rutile phase of TiO 2 can be gained under the mild experiment condition, in which the traditional high temperature calcinations process is no required. Furthermore, the sensor constructed with this composite can be fully used for detecting trace amount of dopamine in biological sample such as urine and serum. It is envisaged that this composite will afford a new insight into the designing of the functional sensing materials. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) has exhibited huge application value in many fields including chemical synthesis, medicine, environmental remediation, and fuel cells. Traditional anthraquinone method for H2O2 commercial production has emerged the drawbacks of toxicity, H2 consumption and high energy input. Photocatalytic production of H2O2, which only requires water, oxygen, solar light and catalyst, is a novel and green technique, and potentially becomes one of the substitutes for anthraquinone method. Herein, we comprehensively review the research progress in the reported semiconductor catalysts, their modification strategies, as well as the related photocatalysis systems and mechanisms for the light driven H2O2 production. In detail, the photocatalysts are introduced from different families including ZnO, g-C3N4, TiO2, metal complexes, metal sulfides, Bi containing semiconductors, and carbon materials. In the meantime, their modification strategies are systematically evaluated aiming at the improvement in the structures and the photoelectrical properties of semiconductors, as well as their effective activation of molecular O2, and inhibition of H2O2 decomposition. Finally, this review is concluded with a brief summary and outlook, and the major challenges for the development of photocatalytic H2O2 production over the emerging semiconductor photocatalysts. [ABSTRACT FROM AUTHOR]

The wide application of xylose in the food, beverage, and pharmaceutical industries, as well as in the booming field of biorefinery, raises the demand for a rapid, accurate, and real-time xylose-sensing technique to rival the conventional methods based on chromatography, spectroscopy, and electrochemical analysis using non-specific enzymes or abiotic catalysts. Herein, a hybrid system comprising polyethylene glycerol swing-arm-tethered NAD+ and xylose dehydrogenase (XDH), coupled with platinum nanoparticles deposited on carbon nanotubes (PtNPs@MWCNTs), was constructed for the real-time sensing of xylose. The use of the PtNPs@MWCNTs composite enhanced the sensitivity of the electric response and reduced the oxidation potential of NADH significantly. Further, the NAD+ immobilization allowed an increase in its microenvironment concentration and facilitated cofactor regeneration. The screen-printed electrode cast with the hybrid system showed a wide xylose detection range of 0.5 to 10 mM or 3.33 to 66.61 mM, and a low detection limit of 0.01 mM or 3.33 mM (S/N = 3), when connected to a potentiostat or a homemade portable biosensor, respectively. The biosensor also exhibited excellent working stability as it retained 82% of its initial performance after 30 days. The analysis of various xylose-containing samples further revealed the merits of our portable xylose biosensor in real-time sensing, including its rapid response, inexpensive instrumentation, and high selectivity, suggesting its great potential in practical applications. [ABSTRACT FROM AUTHOR]

Background: Saline-alkaline stress is a major abiotic stress that is harmful to plant growth worldwide. Two peach cultivars (GF677 and Maotao) display distinct phenotypes under saline-alkaline stress. The molecular mechanism explaining the differences between the two cultivars is still unclear. Results: In the present study, we systematically analysed the changes in GF677 and Maotao leaves upon saline-alkaline stress by using cytological and biochemical technologies as well as comparative transcriptome analysis. Transmission electron microscopy (TEM) observations showed that the structure of granum was dispersive in Maotao chloroplasts. The biochemical analysis revealed that POD activity and the contents of chlorophyll a and chlorophyll b, as well as iron, were notably decreased in Maotao. Comparative transcriptome analysis detected 881 genes with differential expression (including 294 upregulated and 587 downregulated) under the criteria of |log2 Ratio| ≥ 1 and FDR ≤0.01. Gene ontology (GO) analysis showed that all differentially expressed genes (DEGs) were grouped into 30 groups. MapMan annotation of DEGs showed that photosynthesis, antioxidation, ion metabolism, and WRKY TF were activated in GF677, while cell wall degradation, secondary metabolism, starch degradation, MYB TF, and bHLH TF were activated in Maotao. Several iron and stress-related TFs (ppa024966m, ppa010295m, ppa0271826m, ppa002645m, ppa010846m, ppa009439m, ppa008846m, and ppa007708m) were further discussed from a functional perspective based on the phylogenetic tree integration of other species homologues. Conclusions: According to the cytological and molecular differences between the two cultivars, we suggest that the integrity of chloroplast structure and the activation of photosynthesis as well as stress-related genes are crucial for saline-alkaline resistance in GF677. The results presented in this report provide a theoretical basis for cloning saline-alkaline tolerance genes and molecular breeding to improve saline-alkaline tolerance in peach. [ABSTRACT FROM AUTHOR]

A potential method called microwave-assisted aqueous two-phase extraction (MA-ATPE) was developed for concurrent extraction and purification of gentiopicroside from Gentiana scabra Bunge. Formation characteristics of aqueous two-phase system (ATPS) composed of ethanol and 25 kinds of salts were investigated; K2HPO4 (w/w, 21.71%) and ethanol (w/w, 40.72%) were determined to be the optimal compositions of ATPS. Response surface methodology based on Box–Behnken design was used to investigate the extraction conditions, the optimal parameters were summarized as follows: 80°C of extraction temperature, 31 s of extraction time, 11:1 (mL/g) of liquid-to-solid ratio, 100 meshes of particle size and 806 W of microwave power. Under these conditions, the extraction yield of gentiopicroside was 65.32 ± 0.24 mg/g with a recovery of 96.51%. Compared with other four methods, the purity of gentiopicroside in the crude extracts reached 17.16 ± 0.25%, which was significantly higher than that of smashing tissue extraction, microwave assisted-extraction, ultrasonic-assisted extraction and heat reflux extraction, respectively. In addition, the phase-forming salt can be recyclable. Therefore, MA-ATPE was an excellent and alternative technique to the conventional extraction approaches of gentiopicroside. [ABSTRACT FROM AUTHOR]

Synthesis of adipic acid, a key monomer of nylon-66 and polyurethane, from biomass is highly attractive for establishing green and sustainable chemical processes. Here, we report that zirconia-supported rhenium oxide (ReOx/ZrO2) efficiently catalyses the deoxydehydration of cellulose-derived D -glucaric acid, offering adipic acid ester with a yield of 82% by combining with a Pd/C catalyst in subsequent reactions. [ABSTRACT FROM AUTHOR]

This paper studies a hyperbolic tangent oscillator arising in a nonlinear packaging system. The high-order nonlinearity makes it difficult to study the system analytically. A modified homotopy perturbation method is proposed, where the initial guess is an approximate solution of the well-known Duffing oscillator; the solution accuracy can be improved by either improvement of the initial guess or continuous iteration. This paper gives a general approach to high-order nonlinear oscillators. [ABSTRACT FROM AUTHOR]

Mn2+ doping and Au0 modification on MoS 2 nanosheets, and in-situ-Fenton process using photogenerated H 2 O 2. • MoS 2 nanosheets were modified by atomic Au0 for photocatalytic production of H 2 O 2. • H 2 O 2 at a mmol/L level was obtained at pH 9 without pure O 2 or electron donors. • An in situ Fenton system was achieved over Au0-modified Mn2+-doped MoS 2. • Mn2+ doping further increased H 2 O 2 productivity by two times over Au@MoS 2. Au modified MoS 2 nanosheets (Au@MoS 2) for photocatalytic production of H 2 O 2 were prepared via a simple pathway including the deposition–reduction and immobilization process by using a low dosage of an Au source. Nanoparticles smaller than 1 nm and single atoms, as two major forms of Au, were found to be widely dispersed on the surface of MoS 2 and captured by its lattices. Au modification brought out the low recombination rate of e−–h+ pairs, long lifetime of electrons, and more negative flat band potential for MoS 2. Au@MoS 2 achieved efficient photocatalytic production of H 2 O 2 from H 2 O and air in the absence of pure O 2 and organic electron donors. An optimal catalyst loading 0.50 wt% of Au enhanced the H 2 O 2 productivity by about 2.5 times from bare MoS 2. A significant finding was that higher pH was beneficial to H 2 O 2 synthesis, and the H 2 O 2 productivity at pH 9 was further enhanced 7.4 times from that at pH 2. Au@MoS 2 was recycled more than five times without inactivation and obtained considerable 791.72 μM of H 2 O 2 under real sunlight irradiation for 6 h, exhibiting application potential. Mn2+ as the active center for Fenton-like reactions was doped in MoS 2 nanosheets before Au0 modification in order to use the photogenerated H 2 O 2 in situ. Accordingly, a novel in situ Fenton process was proposed, and obtained significant degradation efficiencies for rhodamine B and methylene blue dyes, depending on the H 2 O 2 productivity. Another important finding was that Mn2+ further increased H 2 O 2 productivity by 2 times based on Au@MoS 2. [ABSTRACT FROM AUTHOR]

AbstractThis study explored tourists’ preferences and willingness to pay for travel carbon offset (TCO) products using a hybrid choice model (HCM). This model integrates a mixed multinomial logit model (MMNL) and a latent variable model (LVM) to facilitate the exploration of preference heterogeneity among tourists by incorporating individual psychological constructs. The key empirical results were as follows: (1) the respondents were more likely to purchase a TCO product when they were provided with both TCO and opt-out options; the respondents were willing to pay ¥108 (about US$15.88) for an optimal TCO product for 1-tonne travel carbon emissions; (2) tourists’ preferences for TCO products were influenced by offset- and travel-related factors, including offset quantity, project locations and types, TCO providers and payment time; and (3) green trust and socio-demographic characteristics influenced the respondents’ preferences for TCO products. Through this study, we extend the literature on global warming mitigation, pro-environmental behaviour and discrete choice modelling. Our empirical results can be used by tourism businesses to understand tourists’ demands for TCO products and to provide specific recommendations for developing decarbonisation products. [ABSTRACT FROM AUTHOR]

Prospect theory has been an essential theoretical foundation for behavioral economics, as recognized with the Nobel Prize in economic sciences in 2002. The growing interest in behavioral economics among tourism researchers necessitates a systematic assessment of prospect theory and its application in tourism research to critically examine the current status of tourism decision-making studies. This study therefore clarifies the theoretical background of prospect theory and analyzes 93 published studies to examine how prospect theory has performed in explaining tourism decision-making. The study also evaluates the application of prospect theory in tourism research and provides future research directions with respect to under-researched dimensions, reference points, dynamic decision-making processes, and the logical continuity and systemization of prospect theory. [ABSTRACT FROM AUTHOR]

The H2WO4−Pt/ZrO2 combination catalyses the direct conversion of cellulose into ethanol with a yield of 32% in an aqueous medium under H2. H2WO4 mainly facilitates the cleavage of C–C bonds in the glucose unit, while Pt/ZrO2 with an appropriate fraction of Pt0 and Pt2+ promotes the formation of ethanol through a selective C–O bond activation. [ABSTRACT FROM AUTHOR]

Graphical abstract Construction of hierarchical porous Al-KIL-2 via kinetic regulation. Highlights • Hierarchical aluminosilicates were synthesized via kinetic regulation method. • Hierarchical Al-KIL-2 possessed well distributed bimodal mesopores. • Composition of framework Al and non-framework Al was analyzed by XPS. • Adjustable porous and acidic properties can face to adsorption of various molecules. Abstract Novel hierarchical Al-KIL-2 aluminosilicates with bimodal mesoporous distribution were successfully synthesized via a feasible and cost-effective kinetic regulation method. The molar ratio of Si/Al, the kinetics of Al-Si polyanions growth and its following oriented-attachment on KIL-2 matrix were regulated aiming at various porous and acidic properties. The hierarchical Al-KIL-2 samples were characterized, and their adsorption capacities were tested by adsorptive denitrogenation for model fuels containing pyridine and quinoline. It was revealed that the branching epitaxial growth behavior originating from Al-zoning on KIL-2 matrix contributed to fabrication of the hierarchical porous structures. In addition, introduction of Al endowed KIL-2 with rich Lewis acid sites for the adsorption of basic contaminants. Hierarchical Al-KIL-2 obtained considerable adsorption efficiencies of pyridine and quinoline, the regularities of which relied on the appropriate kinetic regulation conditions during materials synthesis. The adsorption isotherms and adsorption thermodynamics research essentially presented the feature of this adsorptive denitrogenation system over hierarchical Al-KIL-2 for its potential industrial applications. [ABSTRACT FROM AUTHOR]

Abstract A cost-efficient photocatalytic oxidative denitrogenation and desulfurization system for fuels under visible light was developed on the basis of Na doped g-C 3 N 4 nanosheets catalyst. The process adopted molecular O 2 as oxidant to substitute for the expensive H 2 O 2 , and it adapted to the removal of small molecules of pyridine and thiophene. Na doped g-C 3 N 4 nanosheets were obtained via a simple mixed-calcination pathway using NaCl as Na source. The structural, photophysical and chemical properties of the photocatalysts were characterized and compared to those of the original g-C 3 N 4. It was verified that Na was successfully doped in the g-C 3 N 4 lattice in a uniform chemical state. Moderate amount of Na doped in g-C 3 N 4 generated the highly dispersed and porous nanosheets, which further improved the surface energy and reduce the recombination rate of electron-hole pairs. Na doped g-C 3 N 4 exhibited enhanced performance simultaneously in the photocatalytic oxidative denitrogenation and desulfurization. The optimal catalyst obtained considerable removal efficiency for pyridine and thiophene, depending on its improved structural and photochemical properties by Na doping. A proposed mechanism revealed that the holes acted as the major active species for the denitrogenation and desulfurization, while the superoxide radicals originating from the combination of electron and O 2 gave a promotion effect. Graphical abstract Cost-efficient photocatalytic oxidative desulfurization and denitrogenation for fuels containing small molecules of pyridine and thiophene with O 2 over Na doped g-C 3 N 4 catalyst. Image 1075007 Highlights • Simple preparation of porous and highly dispersed Na doped g-C 3 N 4 nanosheets. • Improved photoelectric and photocatalytic performance of g-C 3 N 4 by Na doping. • Photocatalytic oxidative denitrogenation and desulfurization for fuels with molecular O 2. • A cost-efficient system for removal of small molecules of pyridine or thiophene. [ABSTRACT FROM AUTHOR]

Globalization characterizes the economic, social, political, and cultural spheres of the modern world. Tourism has long been claimed as a crucial force shaping globalization, while in turn the developments of the tourism sector are under the influences of growing interdependence across the world. As globalization proceeds, destination countries have become more and more susceptible to local and global events. By linking the existing literature coherently, this study explores a number of themes on economic globalization in tourism. It attempts to identify the forces underpinning globalization and assess the implications on both the supply side and the demand side of the tourism sector. In view of a lack of quantitative evidence, future directions for empirical research have been suggested to investigate the interdependence of tourism demand, the convergence of tourism productivity, and the impact of global events. [ABSTRACT FROM AUTHOR]

The relationship between tourism and economic growth has created a large body of literature investigating the hypotheses of tourism-led economic growth (TLEGH) and economy-driven tourism growth (EDTGH). In this article, we use mixed-frequency Granger causality tests to investigate the relationship between the two types of growth in Hong Kong from 1974 to 2016. Our analysis reveals the following empirical regularities. First, the hidden short-run causality of TLEGH is detected, and EDTGH is proved in the short run and also in the long run when Granger causality tests are performed in a mixed-frequency framework. Second, mixed-frequency Granger tests demonstrate more power in testing the TLEGH and EDTGH via the rejection frequencies (bootstrap p value). Finally, rolling Granger causality tests reveal an unstable relationship between tourism and economic growth in both magnitude and direction, and the relationship is highly economic- and tourism-event-dependent. [ABSTRACT FROM AUTHOR]

MicroRNA (miR)-29 family members have been reported to play important regulatory roles in metabolic disease. We used TargetScan to show that “secreted protein acidic rich in cysteine” (SPARC) is a target of the miR-29s. SPARC is a multifunctional secretory protein involved in a variety of biological activities, and SPARC dysregulation is associated with a wide range of obesity-related disorders, including type 2 diabetes mellitus (T2DM). We explored whether miR-29s played roles in glucose metabolism and whether miR-29s directly targeted SPARC. We also examined the effect of SPARC on glucose metabolism and how the association of miR-29s with SPARC affected glucose metabolism. We found that overexpression of miR-29s reduced glucose uptake and GLUT4 levels; that miR-29 directly targeted SPARC, resulting in degradation of SPARC-encoding mRNA and reduction in the SPARC protein level; that SPARC increased glucose uptake and GLUT4 levels; that shRNA-mediated knockdown of SPARC reduced GLUT4 protein levels in 3T3-L1 adipocytes; that miR-29s reduced glucose uptake and GLUT4 levels; and that miR-29s inhibited glucose uptake by suppressing SPARC synthesis. Thus, the miR-29 family negatively regulates glucose metabolism by inhibiting SPARC expression. [ABSTRACT FROM AUTHOR]

Background: Activated pancreatic stellate cells (PaSCs) are the key cellular source of cancer-associated fibroblasts in the pancreatic stroma of patients with pancreatic ductal adenocarcinoma (PDAC), however, the activation mechanism of PaSCs is not yet known. The Notch signaling pathway, components of which are expressed in stromal cells, is involved in the fibrosis of several organs, including the lung and liver. In the current study, we investigated whether Notch signal transduction is involved in PaSC activation in PDAC.Methods: The expression of Notch signaling pathway components in human PDAC was examined via immunohistochemical staining and assessed in mouse PaSCs using RT-qPCR and western blotting. Notch3 expression in both PDAC stromal cells and activated mouse PaSCs was evaluated using immunofluorescence, RT-qPCR and western blotting. The impact of siRNA-mediated Notch3 knockdown on PaSC activation was detected with RT-qPCR and western blotting, and the impact on PaSC proliferation and migration was detected using CCK-8 assays and scratch experiments. The effect of conditioned medium from PaSCs activated with Notch3 siRNA on pancreatic cancer (LTPA) cells was also detected with CCK-8 assays and scratch experiments. The data were analyzed for statistical significance using Student's t-test.Results: Notch3 was overexpressed in both human PDAC stromal cells and activated mouse PaSCs, and Notch3 knockdown with Notch3 siRNA decreased the proliferation and migration of mouse PaSCs. The levels of markers related to PaSC activation, such as α-smooth muscle actin (α-SMA), collagen I and fibronectin, decreased in response to Notch3 knockdown, indicating that Notch3 plays an important role in PaSC activation. Furthermore, we confirmed that inhibition of PaSC activation via Notch3 siRNA reduced the proliferation and migration of PaSC-induced mouse pancreatic cancer (LTPA) cells.Conclusions: Notch3 inhibition in PaSCs can inhibit the activation, proliferation and migration of PaSCs and reduce the PaSC-induced pro-tumorigenic effect. Therefore, Notch3 silencing in PaSCs is a potential novel therapeutic option for patients with PDAC. [ABSTRACT FROM AUTHOR]

This study introduces bootstrap aggregation (bagging) in modeling and forecasting tourism demand. The aim is to improve the forecast accuracy of predictive regressions while considering fully automated variable selection processes which are particularly useful in industry applications. The procedures considered for variable selection is the general-to-specific (GETS) approach based on statistical inference and stepwise search procedures based on a measure of predictive accuracy (MPA). The evidence based on tourist arrivals from six source markets to Australia overwhelmingly suggests that bagging is effective for improving the forecasting accuracy of the models considered. [ABSTRACT FROM AUTHOR]

Novel titanosilicate composites with bimodal mesopores using molecular sieves Ti-HMS and Ti-KIL-2 as structural components were successfully synthesized by two-step and dual-template methods in a comparative study. The as-synthesized Ti-HMS/KIL-2 samples were characterized by a series of techniques including X-ray diffraction, UV–vis, N 2 sorption and scanning electronic microscopy, and their performance was tested in adsorptive denitrogenation for model fuel containing pyridine or quinoline. Although Ti-HMS/KIL-2 composites were constructed following the different pathway of self-assembly, most of them obtained coexisting properties and structures of Ti-HMS and Ti-KIL-2, as well as the intact framework Ti in tetrahedral coordination. A key finding is that the mesopores size of Ti-KIL-2 component in the composite can be regulated via the introduction of Ti-HMS precursor or organic template dodecylamine. Especially, the composites of dual-template method presented hierarchical mesopores with obvious bimodal distribution. In addition to constructing the hierarchical structure, introduction of Ti-HMS into Ti-KIL-2 matrix improved the adsorptive denitrogenation performance, which was influenced by the synthetic strategy of Ti-HMS/KIL-2. The target adsorbates achieved the best match with the adjustable pores of Ti-HMS/KIL-2. Therefore, (0.6 D )Ti-HMS/KIL-2 and (0.5 T )Ti-HMS/KIL-2 as the optimized adsorbents obtained remarkable adsorption efficiency respectively for pyridine and quinoline. Essence of the adsorptive denitrogenation process was revealed via the adsorption isotherms and the adsorption thermodynamics. Finally, Ti-HMS/KIL-2 composites achieved the improvement in hydrothermal stability and recyclability during adsorption of pyridine and quinoline, and exhibited the potential of industrial application. [ABSTRACT FROM AUTHOR]

Buyanghuanwu Decoction (BHD), a traditional Chinese medicine recipe, is a representative prescription for the treatment of qi-deficiency and blood-stasis syndrome. In this study, the effect of BHD on pressure overload induced cardiac remodeling was investigated and possible mechanism underlying was explored. Rats were randomly divided into four groups: sham, transverse aorta constriction (TAC) with saline, TAC with telmisartan (TAC + Tel), and TAC with BHD (TAC + BHD) for 16 weeks (n = 6 ∼ 8 in each group). Cardiac morphological and functional changes were evaluated by echocardiography and histological methods, the molecular alterations were detected by western blotting. Our results revealed that pressure overload prominently induced cardiac dysfunction, dilated and atrophied left ventricle, decreased cardiomyocyte cross sectional area, and fibrosis. However, BHD, similar to Tel, greatly reversed cardiac dysfunction, left ventricular dilation, and fibrosis, together with increased left ventricular wall thickness and size of cardiomyocyte. Furthermore, activated classical pro-fibrotic signaling of Tgf-β/Smads and MAPKs after TAC was dramatically suppressed by BHD or Tel treatment. Taken together, it was demonstrated in this study that BHD exerted a cardioprotective effect against pressure overload induced cardiac remodeling via inactivation of Tgf-β/Smads and MAPKs signaling triggered fibrosis. [ABSTRACT FROM AUTHOR]

An effective method of concurrent extraction and purification for polysaccharides from Gentiana scabra Bunge stems was developed by microwave-assisted aqueous two-phase extraction (MA-ATPE). Ethanol/sodium dihydrogen phosphate was employed to form aqueous two-phase system (ATPS) by evaluating the extraction properties of five combinations of ethanol/salt systems. The important factors, namely, the composition of ATPS, extraction temperature, solvent-to-material ratio, extraction time and the particle size were investigated by single factor experiment and response surface methodology (RSM) combined with Box–Behnken Design (BBD). The final extraction conditions were concluded as follows: ethanol concentration 21.73% (w/w) and NaH 2 PO 4 concentration 23.27% (w/w) for the ATPS, extraction temperature 95 °C, extraction time 5.8 min, solvent-to-material ratio 21:1 (mL/g) and particle size 80 mesh. Under the optimum conditions, the extraction yield of polysaccharides were 15.97 ± 0.32% for the top phase, 0.58 ± 0.26% for the bottom phase and 16.55 ± 0.13% for total polysaccharides, and the purity of water-soluble polysaccharides was 78.19 ± 0.42%. Compared with smashing tissue extraction (STE), microwave assisted-extraction (MAE), ultrasonic-assisted extraction (UAE) and heat reflux extraction (HRE), microwave-assisted aqueous two-phase extraction not only improved the yield and purity of water-soluble polysaccharides, but also obtained a variety of polysaccharides. In addition, the chemical characterization of polysaccahrides from both the two phases were carried out by Fourier transforms infrared spectrum (FT-IR) and High performance liquid chromatography derivatization with 1-phenyl-3-methy-5-pyrazolone (HPLC-PMP). The extraction mechanism was also discussed by scanning electron microscope (SEM). Therefore, as an efficient and promising technique, microwave-assisted aqueous two-phase extraction may be a viable option for the simultaneous extraction and purification of polysaccharides from plants. [ABSTRACT FROM AUTHOR]

A new model that links climate and seasonal tourism demand is developed to study the effects of home climate, destination climate, and climate difference between destinations and source markets on seasonal tourism demand. Using the dynamic panel data technique, the study focuses on the demand of tourists from Hong Kong for 19 of the major tourism cities in Mainland China. The results show that the home climate, destination climate, and the difference in climate between home and destination cities all have significant influence on tourism demand. Furthermore, demand for Mainland Chinese tourism among Hong Kong residents is found to be driven by the climate at the place of origin, while the effects of destination climate and climate difference are weaker. [ABSTRACT FROM AUTHOR]

Myxomycetes (Myxogastrea) are found in soil as myxamoebae and are a major component of the soil protist flora. Yet, our understanding of the drivers of myxamoebae community assembly lags far behind that of other protist groups. In this study we simultaneously investigate the spatial patterns of myxamoebae and their prey (bacteria and fungi communities) across eight subtropical forests in China, and aim to identify the ecological processes that determine the community assembly of myxamoebae. We found that all three microbial communities exhibited significant distance–decay relationships, with a higher degree of community concordance between myxamoebae and fungi than between myxamoebae and bacteria. The community turnover of both myxamoebae and fungi was primarily influenced by deterministic processes, whereas bacterial assembly was dominant by stochastic processes. Variation partitioning analysis showed that bacterial community structure explained the largest portion of the community turnover of myxamoebae, followed by spatial factors. Co-occurrence network analyses further revealed that myxamoebae had more potential interactions with bacteria than fungi, but did not target specific bacterial or fungal taxa. Overall, the significant effects of biotic and spatial factors on myxamoebae community assembly are critical to deciphering the distribution and function of these ecologically important microorganisms in soil environments. • Myxamoebae community exhibited a significant distance-decay pattern across subtropical forests in China. • Myxamoebae community showed community concordance with fungi and bacteria. • Deterministic processes predominated the myxamoebae and fungal community assembly. • Bacterial community explained the largest portion of the community turnover of myxamoebae. [ABSTRACT FROM AUTHOR]

The development of electrochemical biosensors has gained tremendous attention. Protein engineering has been applied for enhancing properties of native redox enzymes, such as selectivity, sensitivity, and stability required for applicable biosensors. This review highlights recent advances of protein engineering to improve enzymatic catalysis of biosensors, facilitate electron transfer and enzyme immobilization, and construct allosteric protein biosensors. The pros and cons of different protein engineering strategies are briefly discussed, and perspectives are further provided. [Display omitted] • Protein engineering has been widely used to improve biosensor performance. • Enzymatic catalysis and electron transfer both play essential roles. • Oriented enzyme immobilization at enzyme–electrode interface is highly desirable. • Direct electron transfer-based 3rd generation biosensor is the future direction. [ABSTRACT FROM AUTHOR]

Starting from the basic equations of hydrodynamics, the maximum powertype variational principle of the hydrodynamics of viscous fluids was established by Weizang CHIEN in 1984. Through long-term research, it is clarified that the maximum power-type variational principle coincides with the Jourdian principle, which is one of the common principles for analytical mechanics. In the paper, the power-type variational principle is extended to rigid-body dynamics, elasto-dynamics, and rigid-elastic-liquid coupling dynamics. The governing equations of the rigid-elastic-liquid coupling dynamics in the liquid-filled system are obtained by deriving the stationary value conditions. The results show that, with the power-type variational principles studied directly in the state space, some transformations in the time domain space may be omitted in the establishing process, and the rigid-elastic-liquid coupling dynamics can be easily numerically modeled. Moreover, the analysis of the coupling dynamics in the liquid-filled system in this paper agrees well with the numerical analyses of the coupling dynamics in the liquid-filled system offered in the literatures. [ABSTRACT FROM AUTHOR]

A biography of Egon Smeral, college professor in tourism economics at Modul University is presented. He was born in Vienna, Austrria in 1950 and received his education at the University of Vienna. He started his academic career as a scientist in the Austrian Institute of Economics Research (AIER) in 1974. He developed the Tourism Satellite Account (TSA) for Austria.

This study uses meta-analysis to examine the relationship between estimated international tourism demand elasticities and the data characteristics and study features that may affect such empirical estimates. By reviewing 195 studies published during the period 1961–2011, the meta-regression analysis shows that origin, destination, time period, modeling method, data frequency, the inclusion/omission of other explanatory variables and their measures, and sample size all significantly influence the estimates of the demand elasticities generated by a model. Moreover, the demand elasticities at both product and destination levels are generalized by statistically integrating previous empirical estimates. The findings of this meta-analysis will be useful wherever an understanding of the drivers of tourism demand is critically important. [ABSTRACT FROM AUTHOR]

A new electrochemical sensor for HO was constructed by depositing copper doped CuO nanosheets on a glassy carbon electrode (GCE). The morphology and composition of the modified electrode were characterized via scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction. The electrochemical properties of the electrode were studied using cyclic voltammetry and electrochemical impedance spectroscopy. The catalytic performance of the sensor was studied in 100 mM NaOH solution via differential pulse voltammetry and revealed the sensor to display significantly improved electrocatalytic activity with respect to the analysis of the HO in comparison to a plain GCE or a GCE modified with copper only. The response to HO at a working voltage of −0.46 V (vs. Ag/AgCl) is linear in the 0.003 - 8 mM concentration range, and the detection limit is 0.21 mM (at an S/N ratio of 3). Satisfactory results were obtained in the analysis of tap, rain and river waters spiked with HO. The analytical performance of this electrode compares favorably to the results obtained with other commonly used techniques for analysis of HO. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A microwave-assisted enzymatic extraction (MAEE) method had been developed, which was optimized by response surface methodology (RSM) and orthogonal test design, to enhance the extraction of crude polysaccharides (CPS) from the fruit of Schisandra chinensis Baill. The optimum conditions were as follows: microwave irradiation time of 10 min, extraction pH of 4.21, extraction temperature of 47.58 °C, extraction time of 3 h and enzyme concentration of 1.5% (wt% of S. chinensis powder) for cellulase, papain and pectinase, respectively. Under these conditions, the extraction yield of CPS was 7.38 ± 0.21%, which was well in close agreement with the value predicted by the model. The three methods including heat-refluxing extraction (HRE), ultrasonic-assisted extraction (UAE) and enzyme-assisted extraction (EAE) for extracting CPS by RSM were further compared. Results indicated MAEE method had the highest extraction yields of CPS at lower temperature. It was indicated that the proposed approach in this study was a simple and efficient technique for extraction of CPS in S. chinensis Baill. [ABSTRACT FROM AUTHOR]

Rats fed with high-fat-high-sucrose (HFHS) diet are known to manifest metabolic syndrome including hyperinsulinemia, hyperleptinemia, hyperglycemia, diabetic dyslipidemia, and hepatic steatosis. The aim of the current study is to determine the temporal relationships between the development of hepatic steatosis and the onset of insulin and leptin resistance in hypothalamus and liver in male Wistar rats (six weeks of age) fed chow or HFHS diet for up to 8 weeks. Fasting plasma glucose, lipids/lipoproteins, insulin and leptin levels were quantified, histopathologic score of hepatic steatosis and inflammation were assessed, and the responses of common checkpoints of insulin and leptin signalling responsible for lipogenesis and gluconeogenesis were analyzed. In addition, acute insulin or leptin administration was performed at different stages of HFHS dieting to determine the responsiveness of the respective signalling pathways. Hyperinsulinemia, hyperglycemia, dyslipidemia, and increased homeostasis model assessment of basal insulin resistance occurred 1-week after HFHS dieting, coinciding with upregulation of suppressor of cytokine signalling 3 in both hypothalamus and liver. However, hepatosteatosis, accompanied with increased expression of sterol regulatory element binding protein 1c and phosphoenolpyruvate carboxykinase, did not manifest until 4- to 8-week after HFHS dieting. Lowered insulin sensitivity (shown by decreased insulin receptor substrate 1 and protein kinase B phosphorylation) occurred approximately 2 weeks prior to leptin resistance (shown by impaired signal transducer and activator of transcription 3 activation) in both the liver and hypothalamus. Acute insulin/leptin administration also demonstrated the impaired insulin or leptin signalling transduction. These data suggest that lowered insulin sensitivity and leptin resistance occurred at least 2–3 weeks earlier than the manifestation of hepatosteatosis in rats fed HFHS diet. [ABSTRACT FROM AUTHOR]

A novel electrochemical sensor was constructed by depositing copper/copper oxide nano-particles on a glassy carbon electrode (GCE) to produce a Cu@CuO/GCE. The morphology and composition of this modified electrode were characterized with the use of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) techniques. The electrochemical properties of the novel modified GCE electrode were studied using various electrochemical techniques such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The catalytic performance of the sensor was studied with the use of differential pulse voltammetry (DPV) under optimized conditions. The constructed Cu@CuO/GCE sensor showed significantly better electrocatalytic activity for the analysis of the H 2 O 2 in comparison to the Cu/GCE or GCE. The novel sensor produced a linear response for H 2 O 2 analysis in the range of 0.005–8 mM and the detection limit was 0.23 μM (S/N = 3). Satisfactory results were obtained for H 2 O 2 analyses of tap and lake waters. This performance compares very favorably with the results from several other commonly used techniques for analysis of H 2 O 2 . [ABSTRACT FROM AUTHOR]

A novel stir bar-shaped ZnO (sb-ZnO)/nitrite-doped reduce grapheme oxide (N-rGO) nanocomposite (sb-ZnO/N-rGO) was facilely synthesized by using the hydrothermal route. Furthermore, a glassy carbon electrode (GCE) modified with the sb-ZnO/N-rGO nanocomposite was constructed and used as the non-enzymatic nitrite electrochemical sensor (sb-ZnO/N-rGO/GCE). Benefiting from the excellent catalytic activity to the electro-oxidation of nitrite as a result of the synergy of N-rGO and sb-ZnO, the modified electrode displayed a superior amperometric sensing performance toward nitrite detection including lower detection limit (LOD) of 0.13 μM, broad linearity range of 0.2 μM~1.2 mM and 1.5–7.8 mM, high sensitivity, rapid response, remarkable repeatability, outstanding durability, good storage stability and strong resistance against interfering substance. In addition, this sensor showed satisfying recovery between 96.0% and 103.0% to nitrite in practical application involved ham sausage, pickled vegetables as well as tap water. The as-synthesized sb-ZnO/N-rGO composite is a qualified candidate for fabricating nitrite electrochemical sensor, which would have promising application prospect in terms of food analysis and environmental monitoring. • stir bar-shaped ZnO/N-rGO nanocomposite was prepared by a facile hydrothermal method. • Systematic study of electrochemical sensing property of sb-ZnO/N-rGO for nitrite. • Sensor was used for detection of nitrite in ham sausage, pickle and tap water. • The electrochemical sensing mechanism of sb-ZnO/N-rGO for nitrite was explored. [ABSTRACT FROM AUTHOR]

A unique near-spherical ZnO nanostructure was synthesized by using mixed solvents composed of polyethylene glycol-400 (PEG-400) and water at the volume ratio of 12:1 via the solvo-thermal method, and it possessed an ideal morphology with higher uniformity, better dispersion and small particle size. Such ZnO was employed to modify glass carbon electrode (GCE) for the construction of electrochemical sensor, i.e. near-spherical ZnO/GCE, whose nitrite sensing performance was evaluated by Chronoamperometry (CA) and Linear Sweep Voltammetry (LSV). In order to emphasis the superior sensing property and extensive suitability for different electrochemical detection techniques, the excellent but not the same nitrite detection performance obtained from CA and LSV was individually given in detail. This sensor based on CA showed broad linearity range of 0.6 μM–0.22 mM and 0.46 mM–5.5 mM, improved sensitivity of 0.785 μA μM−1 cm−2 accompanied with low LOD of 0.39 μM. With regard to LSV, wide linearity response of 1.9 μM–0.8 mM and 1.08 mM–5.9 mM, high sensitivity of 0.646 μA μM−1 cm−2 with LOD of 0.89 μM were obtained. Meanwhile, this sensor displayed outstanding repeatability with RSD of 2.96% (n = 4), high reproducibility with low RSD (1.72%–2.35%, n = 4), strong selectivity towards nitrite with the concentration set at one-tenth of the interfering substances, ideal stability with the peak current intensity above 90% of its initial value after storage for one month and acceptable recovery of 1.72–2.35% to actual samples including ham sausage, pickle and tap water. The near-spherical ZnO nanomaterial may be a preferred candidate for the fabrication of nitrite electrochemical sensor, which may exhibit a fascinating application in terms of food analysis and environmental monitoring. [Display omitted] • An expected near-spherical ZnO nanostructure was synthesized by using mixed solvent. • Cost-effective nitrite electrochemical sensor with excellent performance was obtained. • Successful application of ZnO/GCE for detecting nitrite in water, ham and pickle. • ZnO′s electrochemical sensing mechanism for detecting nitrite was studied. [ABSTRACT FROM AUTHOR]

On November 1, 1994 an Air Passenger Duty (APD) was introduced in the United Kingdom, and since, this tax continues to be controversial. This article examines the effect of the ADP on UK outbound tourism demand for 10 international destinations. An autoregressive distributed lag model is developed and income, price, and tax elasticities are estimated. The income and price elasticities obtained, ranged between 0.36 and 4.11 and −0.05 and −2.02, respectively. The estimated tax elasticities suggest that the implementation of APD had a negative effect on UK outbound travel for five destinations and the demand is inelastic to changes in taxes although the magnitudes vary across destinations. The general message is that although the stated objective of APD is to reduce travel and associated carbon emissions, the effectiveness of APD, however, has been marginal; travelers are prepared to pay more in the main to maintain their demand. [ABSTRACT FROM PUBLISHER]

Abstract: The self-assembly of layered molybdenum disulfide–graphene (MoS2–Gr) and horseradish peroxidase (HRP) by electrostatic attraction into a novel hybrid nanomaterial (HRP–MoS2–Gr) is reported. The properties of the MoS2–Gr were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (TEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). UV–vis and Fourier transform infrared spectroscopy (FT-IR) indicate that the native structure of the HRP is maintained after the assembly, implying good biocompatibility of MoS2–Gr nanocomposite. Furthermore, the HRP–MoS2–Gr composite is utilized as a biosensor, which displays electrocatalytic activity to hydrogen peroxide (H2O2) with high sensitivity (679.7μAmM−1 cm−2), wide linear range (0.2μM–1.103mM), low detection limit (0.049μM), and fast amperometric response. In addition, the biosensor also exhibits strong anti-interference ability, satisfactory stability and reproducibility. These desirable electrochemical properties are attributed to the good biocompatibility and electron transport efficiency of the MoS2–Gr composite, as well as the high loading of HRP. Therefore, this biosensor is potentially suitable for H2O2 analysis in environmental, pharmaceutical, food or industrial applications. [Copyright &y& Elsevier]

The purpose of this study is to empirically assess the mediating effects of the impact of the perceived image of celebrity endorsers on tourists’ intentions to visit, using celebrity-endorsed print advertisements for travel destinations. The results indicate that celebrity endorsers have a significant impact on people’s attitudes and visit intentions, thus verifying the mediating effects of this variable. The study also provides clues to what extent celebrity-endorsed advertisements differ from nonendorsed advertisements and explores such differences in terms of destination match-up between native and nonnative celebrity-endorsed advertisements. [ABSTRACT FROM PUBLISHER]

Highlights: [•] TBC was produced by ZS catalyzed esterification of citric acid with n-butanol. [•] 40wt.% of ZS/HMS obtained 93% of citric acid conversion and 92% of TBC yield. [•] ZS active species highly dispersed as monolayer on surface of HMS or MCM-41. [•] ZS/HMS possessed Brønsted and Brønsted+Lewis acid sites for esterification. [•] ZS catalyzed esterification obeyed Eley–Rideal mechanism. [ABSTRACT FROM AUTHOR]

Highlights: [•] Three porous ZnO nanostructures were prepared with different zinc salts. [•] Their structure, morphology and gas sensing performance were compared. [•] The influences of anionic species on porous ZnO nanostructures were studied. [•] The enhancement mechanism of porous ZnO gas sensing performance were discussed. [ABSTRACT FROM AUTHOR]

Abstract: Doping is an important and effective way to improve the gas-sensing properties of metal oxide semiconductors. ZnO-doped porous SnO2 hollow nanospheres were successfully synthesized by a controllable and scalable route in order to improve their sensor performance, and then characterized by X-ray diffraction (XRD), high-resolution electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDS). The comparative gas-sensing properties of the pure porous SnO2 hollow nanospheres and ZnO-doped porous SnO2 hollow nanospheres were also investigated. The ZnO-doped porous SnO2 hollow nanospheres exhibited significantly enhanced ethanol sensing properties, including lower operating temperature, stronger sensitivity, faster response–recovery, and better selectivity. The response (R a/R g) of the prepared ZnO-doped porous SnO2 hollow nanospheres to 100ppm ethanol at 150°C is about 14.7, with the response and recovery times being about 10s and 23s, respectively. The possible gas-sensing mechanism was also discussed. [Copyright &y& Elsevier]