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The permanganate index (CODMn), defined as a comprehensive index to measure the degree of surface water pollution by organic matter and reducing inorganic matter, plays an important role in indicating water pollution and evaluating aquatic ecological health. However, remote sensing monitoring of water quality is presently focused mainly on phytoplankton, suspended particulate matter, and yellow substance, while there is still great uncertainty in the retrieval of CODMn. In this study, the Landsat-8 surface reflectance data set from Google Earth Engine and in situ CODMn measurements were matched. The support vector regression (SVR) machine learning model was calibrated using the matchups. With the SVR model, this study estimates the CODMn in Hongze Lake, presents the historical spatiotemporal CODMn distributions, and discusses the affecting factors of the change trend of the CODMn in Hongze Lake. The results showed that the SVR model adequately estimated CODMn, with a sum squared error of 1.49 mg2/L2, a coefficient of determination (R2) of 0.95, and a root mean square error of 0.15 mg/L. CODMn in Hongze Lake was high in general and showed a decreasing trend in the past decade. Huai River, Xinsu River, and Huaihongxin River were still the main sources of oxygen-consuming pollutants in Hongze Lake. The wetland natural reserve near Yugou had a significant effect on reducing CODMn. This study provides not only a scientific reference for the management of CODMn in Hongze Lake, but also a feasible scheme for remote sensing monitoring of CODMn in inland water.

With the development of intensive livestock and poultry breeding, problems associated with pathogenic microorganisms in animal manure are becoming more obvious. The pathogenic bacteria in pig manure may cause zoonotic transmission, which not only hinder the healthy development of livestock and poultry industry, but also harm people's health. In this study, the diversity and abundance of potential pathogens in the composting process of pig manure under three temperature-controlled treatments (high-temperature group, medium-temperature group and low-temperature group) were analyzed based on high-throughput sequencing technology. A total of 13 potential pathogenic bacteria were identified in the pig manure composting process, among which Enterococcus faecalis and Agrobacterium vitis accounted for the largest proportions (12%). Under different temperature-controlled treatments, the abundances of Pseudomonas stutzeri and Acinetobacter baumannii changed most obviously. Moreover, the diversity and abundance of potential pathogens under high-temperature treatment were significantly lower than those under medium-temperature and low-temperature treatment, indicating that high temperature condition of composting could effectively remove pathogenic bacteria and inhibit the growth and reproduction of pathogens.

A novel separating device, Inertial particle separator (IPS), has been developed recently to separate solid particles and to protect the turbine engine from particle erosion damage. Herein first, an advanced model based on IPS was proposed to investigate the deformational behavior of deformable particle separator, and to meet the higher requirements of sand discharge and pneumatic demand, which are operated under hostile working conditions or environments and severe climate conditions. We established a three-dimensional (3D) nonlinear finite element analysis (FEA) model of bump consequently, which was the core of centerbody. The essential material parameters of the FEA model were obtained via experimental data (tensile testing). By comparing the influence of these factors (pressure and laying angle), the deformational behavior of the centerbody was discussed. Finally, based on the simulation results with the experimental data (Schlieren testing), the model was found to perform with high reliability and accuracy, demonstrating the great capability in precisely predicting the deformational characteristics of the bump under practical working environments.

PurposeThis study aims to analyze the relationship between corporate social responsibility (CSR) and quality of accounting report, especially on earnings management (EM). In addition, potential moderators of this relationship are examined.Design/methodology/approachAfter a comprehensive study of potential mechanisms, the authors obtain plenty of empirical results to open the black box of the link between CSR and EM. Meta-analysis is applied on 51 studies from 35 papers. Further analysis is also carried out to determine the moderating effects, such as the cultural and sample selection differences in these papers.FindingsCSR is negatively associated with EM. In addition, this effect is moderated by cultural difference, CSR measurement, and year of sample selection.Research limitations/implicationsTwo patterns of the hypothesis between CSR and EM are confirmed based on agency cost theory, a theoretical shift of corporate ethics based on organizational moral perspective. Several useful suggestions are also provided for future studies on the empirical model and sample selection. Further research is necessary to clarify the agency cost behind the two theoretical patterns.Practical implicationsCSR is not a tool for firms to market but rather a strategy to ensure their consistency with moral principles, indicating that management should pay more attention to the potential damage of the incongruence between CSR and accounting reporting quality. CSR reporting quality remains an important issue for legislature to guarantee continued firm operations.Originality/valueTo the best of the authors’ knowledge, this study is the first to analyze the CSR and EM link using a meta-analysis and to consider its underlying mechanism under the global environment. Previous method design and sample selection are reviewed to provide reference for future studies.

Herein, a novel and sensitive fluorescence method for cartap determination is established on the basis of the inner filter effect (IFE) of gold nanoparticles (Au NPs) on the fluorescence of glutathione protected Cu NCs (GSH-Cu NCs). In the presence of Au NPs, the fluorescence of GSH-Cu NCs was strongly quenched by the IFE because the absorption spectra of Au NPs overlap well with the emission spectra of GSH-Cu NCs. Upon addition of cartap, cartap could induce the aggregation of Au NPs whose absorption spectrum does not overlap with the emission spectrum of GSH-Cu NCs. Then, with the increase in cartap concentration, the IFE-decreased fluorescence was gradually recovered, realizing the fluorescence sensing of cartap. Under optimal conditions, the proposed method has a good linear relationship with cartap concentration in the range of 7-100 nM, and the detection limit is 3.34 nM. In addition, satisfactory results were obtained for cartap analysis using tap water and cabbage as real samples, which demonstrated that the method as-developed would have great practical application prospects.

An extract of cucumber leaves (ECSL) was prepared as a green corrosion inhibitor for carbon steel. Its carbon steel corrosion inhibition performance against 0.5 mol L

Due to the inner filter effect (IFE) between Brilliant Blue (BB) and gold nanoclusters (AuNCs), a simple and rapid approach for BB detection was developed. Since the absorption spectrum of BB has a good overlap with the emission spectrum of the AuNCs, the fluorescence of the AuNC solution was quenched after adding BB. Under optimal conditions, a good linear relationship for detection of BB was obtained from 0.05 to 7.5 μM, and the detection limit was 0.0167 μM. More importantly, the assay was successfully applied to assess BB in food samples such as hard candy, chocolate and dried blueberries, showing its potential in food quality control in the future.

Porous films are attractive materials used in numerous fields, such as catalysis, templating, and separation. In previous examples of porous films prepared from block polymers, the pore size was usually determined by various factors, including mutual interaction between polymer chains, and was hard to precisely manipulate by modification of the block polymers. Herein, we report a novel method of preparing porous films from cyclic block copolymers with the pore size determined by the size of individual components. The incompatibility of the dangling polystyrene arms and cyclic polysiloxane backbones drove the assembly, which then led to the vertical alignment of the cyclic polysiloxane backbone to form porous films. Coarse-grained molecular dynamics simulations were also implemented to gain insight into the assembly process and the film microstructure at the molecular scale. A cyclic block copolymer allows feasible fabrication of porous films through designed interaction between its macromolecular arms. The morphology of pores is directly determined by the structural features of the block copolymer and can be easily tuned by modification of the length of its ring and arms.

Carbon nanodots (CDs) with superior fluorescence performance were obtained by hydrothermal method using tomatoes as raw materials. When the ultraviolet absorption band of tartrazine and the fluorescence spectrum of CDs have complementary overlaps, the fluorescent internal filter effect (IFE) occurred. Furthermore, the degree of quenching of fluorescence intensity of CDs has an excellent linear correlation with tartrazine concentration. And based on this principle, a method for detecting tartrazine was established. As the decrease of fluorescence intensity, tartrazine can be measured in the linear range of 0.1 μM ~ 40 μM. The detection limit is 39 nM, and the recovery rate is 90.7%~114.5%. The established protocol was also effectively employed to assay tartrazine in beverage samples, indicating that it has great potential for food color analysis.

The floating raft vibration isolation system includes upper and lower isolators and middle raft. As one of the most important parts that affect the performance of vibration isolation, the raft is usually assumed to be an undamped or viscous damping structure in the analysis, which is different from the actual situation. To study the effects of raft with hysteresis damping characteristics, a three-freedom complex stiffness mechanical model was built, and an approach for calculating the raft's force transmission rate was derived from impedance methods. Based on the mechanical model and a large-sized floating raft, we analysed the effects of raft mass, stiffness and damping on vibration isolation through numerical calculation. Results show that increasing raft mass improved vibration isolation over most frequency ranges; increase in raft stiffness contributed to improved isolation performance over frequency ranges near its low-order natural frequencies, while reduced the performance over higher frequency ranges; and greater raft damping led to enhanced vibration isolation at its natural frequencies and higher frequency ranges.

In this work, a novel ratiometric fluorescent sensor, based on carbon dots (CDs) and gold nanoclusters (AuNCs), is developed for highly sensitive and selective visual colorimetric detection of Cu2+ and alkaline phosphatase (ALP). The ratiometric fluorescent sensor was synthesized by covalently linking 11-mercaptoundecanoic acid (11-MUA)–stabilized AuNCs to the surface of amino-functionalized CD/SiO2 nanoparticles. The red fluorescence of the AuNCs can be quenched by Cu2+ owing to coordination between Cu2+ and 11-MUA; however, the blue emission of the CDs was insensitive to Cu2+ owing to the protective silica shell. The quenching of the AuNCs’ fluorescence returned when PPi was added because of the higher affinity between Cu2+ and PPi than that between Cu2+ and 11-MUA. In the presence of ALP, PPi was catalytically hydrolyzed into phosphate (Pi), which showed a much weaker affinity for Cu2+. Thus, Cu2+ ions were released, and the fluorescence of the AuNCs was quenched once more. Based on this principle, Cu2+ and ALP could be simultaneously detected. The developed ratiometric fluorescent sensor could detect Cu2+ over a range from 0.025 to 4 μM with a detection limit of 0.013 μM and ALP over a range from 0.12 to 15 U/L with a detection limit of 0.05 U/L. The present method was successfully applied for the detection of Cu2+ and ALP in real water samples and in human serum samples, respectively. This ratiometric fluorescent approach may provide a highly sensitive and accurate platform for visual Cu2+ and ALP sensing in environmental monitoring and medical diagnosis.

Purpose This study mainly aims to examine whether entrepreneurs’ utilization of political connections is purely egoistic. Addressing this issue could shed light on traditional debate which concerns whether political connections still have strategic value at advanced stage of institutional transition today in China. Here, at the background of Chinese economic transformation, the utilization of political connections is studied, and a double-role model of the pro-self-mechanism and the pro-social mechanism between political connections and performance in China is put forward. Design/methodology/approach This study uses survey of questionnaires randomly from 363 entrepreneurs in Jiangsu, Anhui and Shandong Provinces of China and adopts the first stage and direct moderation model in examination. Findings The results show that there exists mediated mechanism of both pro-self and pro-social mechanism in the relationship between political connections and firm performance. The authors conclude that utilization of political connections is not only purely egoistic but also altruistic. So, both dark-side and bright-side mechanisms of political connections in China are of equal importance. In addition, the authors take into consideration of the contingency effects of institution, industry and firm-level factors of this moderation model. The pro-self and pro-social mechanisms have differences in terms of moderator-within and moderator-between comparisons of these three contingency effects. Among these comparisons, the pro-self-mediating mechanism is most sensitive to changes of institutional quality, whereas the pro-social mediating mechanism is most sensitive to the uncertainty of industry competition. Research limitations/implications This evidence furthermore verifies that the process of institutional transition is nonlinear and political connections still have strategic value in advanced stage of institutional transition today. Originality/value This study combines the dual perspectives of “give” and “take.” The former implies the pro-social motivation, while the latter implies the pro-self-motivation. Based on the framework of “resource-conduct-performance,” this study explores how these two mechanisms mediate the relationship between political ties and firm performance. In addition, the authors adopt the framework of “Strategy Tripod,” which was proposed by Peng et al. (2009) and examine the difference between pro-self and pro-social motivation at different level of institution environment improvement, industry dynamics and firm absorptive capacity.

LiDAR (Light Detection and Ranging)-based individual tree crown reconstruction is a challenge task due to the variable canopy morphologies and the penetrating properties of LiDAR to tree crown surfaces. Traditional methods, including LiDAR-derived rasterization, low-pass filtering smooth algorithm, and original triangular irregular network (TIN) model, have difficulties in balancing morphological accuracy and model smoothness. To address this issue, a scene-based TIN was generated with three steps based on the local scene principle. First, local Delaunay triangles were formed through connecting neighboring point sets. Second, key control points within each local Delaunay triangle, including steeple, inverted tip, ridge, saddle, and horseshoe shape control points, were extracted by analyzing multiple local scenes. These key points were derived to determine the fluctuations of forest canopies. Third, the scene-based TIN model was generated using the control points as nodes. Visual analysis indicates the new model can accurately reconstruct different canopy shapes with a relatively smooth surface, and statistical analysis of individual trees confirms that the overall error of the new model is smaller than others. Especially, the scene-based TIN derived raster reduced the average error to 0.18 m, with a standard deviation of 0.41, while the average errors of LiDAR-derived raster, low-pass filtered smooth raster, and original TIN derived raster have average errors of 0.96, 2.05, and 1.00 m, respectively. The local scene-based control point extraction also reduces data storage due to the elimination of redundant points, and furthermore the different point densities on different objects are beneficial for canopy segmentation.

Crown-level tree species classification is a challenging task due to the spectral similarity among different tree species. Shadow, underlying objects, and other materials within a crown may decrease the purity of extracted crown spectra and further reduce classification accuracy. To address this problem, an innovative pixel-weighting approach was developed for tree species classification at the crown level. The method utilized high density discrete LiDAR data for individual tree delineation and Airborne Imaging Spectrometer for Applications (AISA) hyperspectral imagery for pure crown-scale spectra extraction. Specifically, three steps were included: 1) individual tree identification using LiDAR data, 2) pixel-weighted representative crown spectra calculation using hyperspectral imagery, with which pixel-based illuminated-leaf fractions estimated using a linear spectral mixture analysis (LSMA) were employed as weighted factors, and 3) representative spectra based tree species classification was performed through applying a support vector machine (SVM) approach. Analysis of results suggests that the developed pixel-weighting approach (OA = 82.12%, Kc = 0.74) performed better than treetop-based (OA = 70.86%, Kc = 0.58) and pixel-majority methods (OA = 72.26, Kc = 0.62) in terms of classification accuracy. McNemar tests indicated the differences in accuracy between pixel-weighting and treetop-based approaches as well as that between pixel-weighting and pixel-majority approaches were statistically significant.

Individual tree identification is a key step for forest surveying and monitoring. To identify individual trees with airborne LiDAR data, a local maximum (LM) filter technique is typically performed. With LM, the highest point in a filtering window is generally considered to represent the tree position. This assumption, however, has great limitations, especially for mixed forests. To address this problem, we developed a new approach, the cluster center of higher points (CCHP), for tree position detection with LiDAR data. CCHP assumes that a tree position is located at the clustering center of higher points within a spatial neighborhood, and the center can be detected by a location-based recursive algorithm. The developed CCHP method was applied to a simulated forest and then verified in two real urban forests. In comparison with the variable window-sized LM filter method and layer stacking method, CCHP successfully identified 97% of trees in the simulated forest, while only 78% and 81% of the trees were recognized by LM and layer stacking methods respectively. The average absolute and relative offsets of CCHP are 0.33 m and 6.59%, respectively, and over 80% of the detected trees have an offset of less than 10% of the tree crown radius. CCHP also correctly detected 93.80% and 88.74% of individual trees in the first and second real forests, respectively, but the detection rates from the variable window-sized LM approach and layer stacking were less than 80%. In addition, the tree positions located by CCHP are considerably more accurate than the other two methods. Therefore, CCHP is proven to be promising for detecting individual tree positions from airborne LiDAR data for both simulated and real forests.

The present study reports the fabrication of mesoporous-structured ratiometric molecularly imprinted sensors using a combined surface-imprinted and ratiometric fluorescence method. The sensors were subsequently examined in the selective and sensitive determination of 2,4,6-trinitrophenol (TNP). In the preparation of the ratiometric system, the reference dye CdTe quantum dots were embedded in silica core particles via the Stober method; the functional target sensitive dye AAMBT&SiO 2 , which was obtained via polymerization of 2-acrylamide-6-methoxybenzothiazole (AAMBT) with allyltriethoxysilane, was embedded in the mesoporous silica shell. In the surface imprinting process, cetyltrimethylammonium bromide was employed to create mesoporous-structured silica to promote quenching of AAMBT by TNP via resonance energy transfer, thereby enhancing the sensitivity of the sensor. Under optimum conditions, the ratiometric fluorescence molecularly imprinted polymer sensors achieved a detection limit of 43 nM within 3 min. The practical application of the developed sensor in real water samples was successfully demonstrated through analysis of TNP in water samples, achieving satisfactory recoveries of 92–104%. Thus, a convenient and practical method for preparing highly selective and sensitive ratiometric fluorescence sensors is presented herein, providing a prospective method for rapid trace pollutants analysis in complex water samples.

In this work, a novel approach for simple and sensitive determination of alkaline phosphatase (ALP) is developed on the basis of an inner filter effect of p-nitrophenylphosphate (PNPP) on the fluorescence of gold nanoclusters (AuNCs). AuNCs with a high quantum yield of 12% were synthesized by one-pot strategy and were directly applied as fluorescent substance. When AuNCs were mixed with PNPP, the fluorescence of the AuNCs was remarkably quenched or was decreased via the inner filter effect since the absorption spectrum of PNPP overlaps well with the excitation spectrum of the AuNCs. While in the presence of ALP, PNPP was catalytically hydrolyzed into p-nitrophenol, which has different absorption characteristics from those of PNPP, resulting in the recovery of the AuNCs fluorescence. Thus, a novel "turn-on" fluorescent sensor for detecting ALP was established with a detection limit as low as 0.002 U/L (signal-to-noise ratio of 3). The turn-on fluorescent sensor exhibits many merits such as high sensitivity, excellent selectivity, and high signal output because of the low background signals. In addition, the developed sensing method was successfully applied to investigate ALP inhibitors and ALP determination in serum samples. A good linear relationship was obtained in the range from 0.02 to 50 U/L, and satisfactory recoveries at four spiking levels of ALP ranged from 95% to 106% with precision below 5%. The very simple sensing approach proposed here should promote the development of fluorescence turn-on chemosensors for chemo/biodetection.

Light detection and ranging (LiDAR) is a promising technology for extracting forest biophysical parameters, including tree height, total volume, biomass, etc. However, tree crown width estimation at the individual level is challenging due to overlapping crown surfaces in urban forests. The objective of this study, therefore, is to develop an approach for estimating tree crown width at the individual tree level using airborne LiDAR data in an urban area. To reach this objective, we constructed a general geometric model for each tree, centering at the tree position on the ground to fit the LiDAR-derived crown surface and then predicted crown width using tree height and shape-related parameters as independent variables and the ground measurement of all the crown widths identified by LiDAR data as dependent variables. Analyses of results suggest that tree crown widths in a mixed forest can be successfully extracted through model-based linear regression analysis, which can explain 88.5 % of variance as...

We tested a simple and economical approach to synthesize CdTe quantum dots (QDs). We then developed a MIP-capped CdTe QD fluorescent sensor by anchoring a molecularly imprinted polymer (MIP) layer on the surface of CdTe QDs using 3-aminopropyltriethoxysilane as the functional monomer and tetramethoxysilane as the cross-linker via a surface molecular imprinting process. The sensor possessed the sensitivity of CdTe QDs, the selectivity of the molecular imprinting technique, and a nearly spherical morphology. The fluorescence of the MIP-capped CdTe QDs can be efficiently quenched when the template 4-nitrophenol (4-NP) rebinds to the binding sites, as a result of the charge transfer from QDs (donor) to 4-NP (acceptor). MIP-capped CdTe QDs generated a significantly reduced fluorescence intensity within the initial 12 min of binding 4-NP. Under optimized conditions, the sensor presented a satisfactory linearity with 4-NP concentrations in the range of 1–30 μM, and the detection limit was 40 nM. The sensor also successfully detected trace amounts of 4-NP in water samples, and the recovery of 4-NP in three spiked samples ranged from 95.1% to 98.1% with relative standard deviations below 4.3%. The results provide an alternative method for the development of sensors for the rapid recognition and determination of 4-NP in water samples.

Herein, we report a highly stable and water-soluble gold nanoparticles assembly obtained by using a unique cyclic polysiloxane as the soluble support. The assembly is unprecedentedly stable in concentrated solutions of various electrolytes and thiol molecules, and exhibits noticeable catalytic activity for nitrophenol reduction, of which the rate is enhanced through the plasmonic resonance effect. It is also revealed that the light acceleration effect strongly depends on the interparticle distances. The assembly can be further engineered in terms of the inter-particle distances and chemical compositions for the utilization of the plasmonic effect in the future.

The structural character of flexible clamp stretch forming machine is introduced. The real stress and strain curve of Aluminium alloy 2024-O is tested by uniaxial tensile. Numerical simulation of dimple for spherical part with flexible clamp multi-point stretch forming (FCMPSF) is carried out by ABAQUS, and the generated result of dimple is elaborated. The effects of transitional length, sheet thickness and spherical radius on dimple are investigated by lots of numerical simulations, and the thickness strain of spherical part along the objective line ef with different forming suitation is extracted. Then polyurethane sheet is chosen as elastic cushion to depress dimple, and series of numerical simulations are put forward for spherical part of FCMPSF with different thicknesses of polyurethane sheet. Finally, FCMPSF experiment is done and forming precision is measured. Consequently, the spherical part has good forming shape and surface accuracy, which illustrates that the FCMPSF technology is feasible and practional to forming three-dimensional surface part.

Intermediaries are frequently used as external institutions to bridge knowledge gaps and enlarge innovation search. Although there is a consensus that ties with intermediaries have a significantly positive impact on firms’ innovation performance since external knowledge sources are important to firms’ innovative activities, far less is known about how these intermediaries become effective drivers of corporate innovation. From the capacity-based view, this study proposes that intermediaries facilitate the development of dynamic capability which further causes remarkable innovation. A firm's dynamic capability acts as a mediator in the relationship between intermediaries and innovation performance. It is also observed that organizational structure formalization and strategic conformity negatively moderate the mediation effect. This proposed theoretical framework is proven by empirical results from a moderated mediation analysis using a sample of Chinese manufacturing firms.

Background This study aimed to identify potential predictive factors for the survival of advanced non small-cell lung cancer (NSCLC) patients undergoing first-line platinum-based chemotherapy. Methods A total of 270 advanced NSCLC patients who underwent first-line platinum-based chemotherapy from June, 2011 to June, 2015 were enrolled. A receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive value of the albumin-to-fibrinogen ratio (AFR) for overall survival (OS). The predictive factors for survival were evaluated by univariate and multivariate analyses via the Cox proportional hazards regression model. The OS and progression free survival (PFS) results were determined via the Kaplan–Meier method using the log-rank analysis. Results Based on the results of the ROC curve analysis, 8.02 was accepted as the cut-off AFR value for OS. The metastasis stage (M0 vs M1a/b, HR: 1.73, 95% CI: 1.15–2.59, P = 0.020) and AFR (≤8.02 vs > 8.02, HR: 1.80, 95% CI: 1.09–2.78, P = 0.025) were two independent risk factors for PFS by multivariate Cox regression analysis. The AFR (≤8.02 vs > 8.02, HR: 1.79, 95% CI: 1.11–2.59, P = 0.029) was a significant predictive factor for OS in advanced NSCLC patients. The PFS (P = 0.008) and OS (P = 0.003) in the high AFR group were significantly improved compared with those in the low AFR group via the Kaplan–Meier method using the log-rank analysis. Conclusions The AFR could be a potential effective predictive factor for the survival in advanced NSCLC patients undergoing first-line platinum-based chemotherapy.

The paper is a study of the noise reduction effects of the stator lean angle. Firstly, a numerical study has been carried out to investigate the unsteady characteristics of the flow induced by the rotor-stator interaction. To obtain the rotor‟s wake, the distribution of the RMS pressure and the pressure disturbance coefficient, the compressor with an adjustable stator lean angle has been numerically studied. Then the compressor was experimentally tested at 11 different lean angles to obtain the free field noise spectra. Both the unsteady flow property and noise characteristics are discussed on the basis of the Computational Fluid Dynamics (CFD) results. The results indicate that (1) the pressure fluctuation of stator is the main source of the interaction noise; (2) the phase of rotor‟s wake can be tuned by the lean angle of the stator; (3) the distribution of the first harmonic of tone noise decides the distribution of total Sound Pressure level (SPL); and (4) stator with positive lean angle has b...

A layer-by-layer self-assembly method leads to the formation of Au@ZnMoS4 core-shell nanoparticles (NPs). The PEGylated Au@ZnMoS4 NPs are highly water-dispersible, exhibit no cytotoxicity and can penetrate the cell membrane to selectively remove copper(I) ions from HepG2 cells in the presence of other endogenous and biologically essential metal ions including Mg(II), Ca(II), Mn(II) and Fe(II), demonstrating their potential as a novel intracellular copper detoxifying agent.

Isoflurane anesthesia can cause post-operative cognitive dysfunction in elderly patients. As an isomer of isoflurane, enflurane may also account for cognitive dysfunction. However, the mechanism of enflurane-induced cognitive dysfunction remains obscure. In this study, we investigated the effects of enflurane anesthesia on cognitive function and the possible roles of β-amyloid protein and phosphorylated tau protein in response to enflurane anesthesia in aged rats. After intraperitoneal injection of enflurane, the Morris water maze and the step-down passive avoidance tests were conducted to test the cognitive ability and memory. The enflurane group showed prolonged escape latency, extended space exploration time and increased number of errors at early stage after enflurane anesthesia, suggesting that enflurane should be responsible for the impairment of cognition in aged rats. In addition, we analyzed the expression level of β-amyloid and phosphorylation level of tau in the hippocampus by immunoblotting. Interestingly, the levels of β-amyloid and phosphorylated tau in the hippocampus increased significantly at early stage and then restored to pre-anesthetic levels. Taken together, our results suggest that increasing of β-amyloid and phosphorylation of tau are important to cause cognitive decline in aged rats during initial stage after enflurane anesthesia.

Although intermediaries frequently bridge knowledge gaps and enhance innovation searches as important sources of external knowledge, the mechanisms regarding how and when intermediaries become effective drivers of corporate innovation still remain indistinct. Using a sample of Chinese manufacturing firms, this study proposes and empirically tests a theoretical framework for understanding the effects of intermediaries on corporate innovation performance. The results of a moderated mediation analysis show that firms' ties to intermediaries can contribute to innovation by enhancing the scope of external innovation searches and reducing search costs. Absorptive capacity acts as a mediator in the relationship between intermediaries and innovation performance. Environmental munificence and complexity negatively moderate this mediation effect.

Research Summary: We examine the value of political ties on firm performance in an emerging economy. Using social exchange theory, we posit that political connections propel firms to engage more in proself and prosocial activities, which mediate the relationship between political ties and firm performance. The institutional environment moderates the dual mediations such that as the institutional environment improves, the mediation effect through proself engagement weakens, whereas the mediation effect through prosocial engagement strengthens. We found support for these propositions by analyzing two samples of firms in China: A surveyed sample of 363 small- and medium-sized firms and data from 2,780 publicly listed firms from 1999 to 2014. Our findings shed light on the strategic value of political ties, coinciding with the development of institutional environments.

The title compound, CH3OCOCH2CH2SnCl2(OH) (1), readily undergotransesterification into the corresponding analogues, ROCOCH2CH2SnCl2(OH) (R = CH3CH2, 2; CH3CH2CH2, 3; CH2=CHCH2,4), when reacted with an alcohol ROH under reflux. The structural featuresof these compounds have been described, and the possible mechanismof the transesterification reaction has been suggested.

The multi-point thermoforming (MPTF) machine and process of resin sheet were introduced, the glass transition temperature and stress relaxation curves of Polymethylmethacrylate (PMMA) sheet were tested, and the material parameters of PMMA sheet were got. Lots of numerical simulation of wrinkle for spherical part with MPTF of PMMA sheet were put forward, the effects of thickness, radius and forming temperature on the wrinkle were investigated, and the non-wrinkle forming limit diagram are determined. Then, MPTF experiments of spherical part with PMMA sheet was done to verify the numerical results. Consequently, the spherical part has good shape accuracy, which confirms that PMMA sheet formed by MPTF is feasible and the non-wrinkle forming limit diagram obtained by numerical simulation is practicable.

This paper focuses on the noise reduction benefits of stator lean effect for rotor-stator interaction. The compressor with 3 blade lean angle of downstream stator was investigated by experimental and numerical study. The noise spectra of the acoustic measurement were obtained by the outside noise test. And the tone noise was extracted from the total noise sound pressure level (SPL). The unsteady loading of the stators' blade surface were also obtained. The pressure fluctuation amplitude was extracted from the numerical study, and the phase distribution of the wake presented the detail distribution of the wake phase. The numerical study shows that lean positive has less unsteady loading than negative, and lean positive case has the maximum phase lag.

The rotor-stator interaction in a 1.5 stage compressor with different lean angle of downstream stator blades was investigated by aeroacoustic and numerical study. The aeroacoustic performance with narrow spectra, the sound pressure level distribution and the unsteady loading of the compressor were tested and analyzed. The RMS pressure, the axial thrust and torque of the downstream stator blade distribution revealed the unsteady characteristic of rotor-stator interaction at different downstream stator blade lean angle. The positive lean stator had better noise constraint than the negative lean stator. However, the RMS pressure and the unsteady force increased with the increase of the lean angle when the stator had positive lean angle. The time-spatial contours of the axial velocity demonstrated the effect of time delay for the rotor wake intersection with the leading edge of the stator blade. And the phase lag distribution of the wake presented the detail distribution of the wake phase along the span. The downstream stator blade lean was effective to obtain a significant reduction for the unsteady force and get large phase lag for the rotor’s wake of rotor-stator interaction. Leaned positive blade had better benefits than negative for the noise reduction and the phase lag of the wake.Copyright © 2013 by ASME