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Four alkoxoiron(III) complexes of N,N,N′,N′-tetrakis(2-benzimidazolyl-methyl)- ortho -diamine- trans -cyclohexane (ctb) in alcohol/MeCN have been synthesized and characterized as models of lipoxygenase. [Display omitted] • Four novel lipoxygenase model complexes were synthesized and characterized. • These alkoxoiron(III) complexes could be reduced with alkene via H-abstraction reaction. • The total reaction rate might be mainly contributed by the subsequent H-abstractions. Four lipoxygenase model complexes, [FeIII(OMe)(Hctb)](ClO 4) 3 ·3MeOH·4.5H 2 O (1), [FeIII(OEt)(Hctb)](ClO 4) 3 ·EtOH (2), [FeIII(OPr n)(Hctb)](ClO 4) 3 · n -PrOH·H 2 O (3) and [FeIII(OBu n)(Hctb)](ClO 4) 3 · n -BuOH·H 2 O (4) have been synthesized by reacting N,N,N′,N′-tetrakis(2-benzimidazolyl-methyl)- ortho -diamine- trans -cyclohexane (ctb) with Fe(ClO 4) 3 ·9H 2 O in alcohol/MeCN. These alkoxoiron(III) complexes all possess (i) an octahedral Fe(III)-OR center (R = Me, 1 ; Et, 2 ; n -Pr, 3 ; n -Bu, 4) with Fe-O bond lengths between 1.79 and 1.81 Å, (ii) a red-yellow colour, and (iii) an intense electronic transition around 370 nm. Complexes 1 – 4 can be reduced by cis , cis -1,4-diene via a H-abstraction mechanism. DFT calculations reveal the reaction rates are attributed to the H-abstraction reaction between the alkoxy unit and conjugated alkene. [ABSTRACT FROM AUTHOR]

• Microcapsules with transit temperature of 40 °C (TAM40) were prepared. • Increasing TAM40 content and mixing temperature reduced workability. • High TAM40 content and mixing temperature reduced compression and drying shrinkage. • Better healing was achieved by adding TAM40 and mixing at high temperatures. The ease to be ruptured during mixing due to the brittleness of microcapsule shell limits the self-healing performance of microcapsules in concrete. In this study, a novel type of microcapsule with temperature-adaptive property (TAM) under different mixing temperatures was proposed to tackle this issue. The effect of TAM content and mixing temperature in self-healing cementitious materials was investigated. Based upon the confirmation of temperature adaptivity of microcapsule shell by dynamic mechanical analysis, the early age properties, including minislump, setting time and hydration heat, and the hardened properties of compressive strength and shrinkage, were determined. Moreover, the self-healing performance, in terms of strength healing and recovery rate, as well as the pore structures, of TAM in cementitious material was investigated. The results showed that the addition of TAM decreased workability and slightly extended the setting and hydration of cement, while the elevation of mixing temperature reduced workability and accelerated the setting and hydration of cement. Moreover, the addition of TAM and low mixing temperature reduced the compressive strength and shrinkage of hardened paste. Compared to the low mixing temperature, the self-healing performance in terms of strength and chloride migration was improved at high mixing temperature. The results proved the design concept of temperature adaptive microcapsules. [ABSTRACT FROM AUTHOR]

Graphitization (1400 °C–2200 °C) of polyacrylonitrile (PAN)-based carbon fiber in a small furnace with direct electric heating by Joule effect was studied in situ by small angle X-ray scattering (SAXS) with X-ray synchrotron radiation. The two-dimensional SAXS images display an anisotropic shape indicating the existence of needle-like or elongated ellipsoid-shaped pores oriented along the fiber axis. The one-dimensional scattering curves display obvious positive deviation from Porod's law indicating the existence of micro-fluctuation of electron density in the skeleton of the fiber which give rise to additional scattering. After correcting the deviation from Porod's law, the pure pore scattering was derived, and the pore structure parameters were computed. The results show that with increasing temperature the orientation angle decreases whereas the orientation degree increases. The long axis decreases whereas the short axis increases leading to a lower axial ratio. The size distribution becomes broader and there is a maximum value of porosity and specific surface area at 1900 °C. The change of pore structure in the fiber with temperatures can be approximately divided into two stages corresponding to denitrification condensation (1400 °C–1900 °C) and structure rearrangement (1900 °C–2200 °C) during graphitization, respectively. The corresponding mechanism was analyzed. Reciprocal relationship between the orientation of the needle-like or elongated ellipsoid-shaped pores in carbon fiber and the scattering images (inspired from Macromolecules, 2000, 33, 1848–1852; Polymer, 2001, 42, 1601–1612; Journal of Light Scattering (In Chinese), 2021, 33, 328–334). The left is schematic diagram and the right is actual sample and SAXS images. Where φ is the orientation angle of pore, L is the long axis of pore, r is the short axis of pore, q 12 and q 3 are the components of the reciprocal space vector q (q = 4π·sinθ/λ, 2θ is the scattering angle, λ is the incident X-ray wavelength) in the directions perpendicular and parallel to the principal axis of the pore, respectively. [Display omitted] • In-situ SAXS study on PAN-based carbon fiber during graphitization (1400 °C–2200 °C). • Obvious positive deviation from Porod's law for all measured SAXS curves. • Change of pore structure of fiber in two stages dividing by 1900 °C. [ABSTRACT FROM AUTHOR]

Two mononuclear Dy3+ compounds [Dy(bmbpen-F)X] (X = Cl, 1; Br, 2) with a pentagonal bipyramidal (PBP) geometry were obtained from N,N′-bis-(5-methyl-2-hydroxybenzyl)-N,N′-bis(5-fluoro-2-methylpyridyl)ethylenediamine (H2bmbpen-F) and dysprosium halides. The magnetic anisotropy and single-molecule magnet (SMM) behavior of these PBP compounds were regulated by introducing both electron-withdrawing F atoms into the equatorial pyridine rings and electron-donating –CH3 groups into the axial phenolic hydroxyl rings. The results of magnetic characterization show that 1 and 2 exhibit single molecule magnet behavior with magnetization reversal barriers of 990(13) and 1189(16) K under a zero dc external field and magnetic hysteresis loops up to 26 K and 36 K, respectively. The results of ab initio calculations are consistent with the experimental observations, confirming that the simultaneous introduction of electron-withdrawing groups into the equatorial positions and electron-donating groups into the axial positions can lead to PBP Dy-SMMs with improved properties. [ABSTRACT FROM AUTHOR]

The change in the fractal structure of anthracite mined in Jincheng, China, during high-temperature (1200°C) carbonisation was studied in situ by small-angle X-ray scattering (SAXS) at Beijing Synchrotron Radiation Facility (BSRF). The results show that, during carbonisation, the anthracite structure changes from a pore fractal to a surface fractal and then back to a pore fractal. With increase of temperature, the fractal dimension of the sample presents a trend of rise, decline, rise and decline again, which probably corresponds to the four stages of physical desorption, thermal decomposition, thermal condensation, and residual carbon aging in the process of carbonisation. The pore fractal exists in the initial and final stages, and the surface fractal exists in the middle two stages. [ABSTRACT FROM AUTHOR]

High temperature carbonization, an important approach to cleanly and efficiently use coal, refers to a complex process in which a series of physical phenomena and chemical reactions occur when coal is heated to ≥1000 °C in anoxic conditions. A furnace was developed for the in-situ small angle X-ray scattering (SAXS) and wide angle X-ray scattering (WAXS) measurements with the scattering angle 2θ between 0° and 60° during sample heating from room temperature to 1200 °C. The usefulness of the furnace for high temperature carbonization of coal was verified at the 1W2A SAXS station at the Beijing Synchrotron Radiation Facility (BSRF). [ABSTRACT FROM AUTHOR]

In this paper, a micromechanics-based constitutive model is proposed for linear viscoelastic fiber-reinforced composites via a homogenization procedure in the time domain. Based on an additive decomposition, a general deformation is split into four simple deformations, namely, longitudinal tension/compression, transversely hydrostatic deformation, along-fiber shear and transverse shear. For each simple deformation, the mechanical response of the composite is reformulated utilizing the effective time-dependent relaxation functions and the effective referred elastic (time-independent) stresses, which are computed based on micromechanics. The constitutive equations for the linear viscoelastic fiber-reinforced composites are then derived through superposing the effective stresses for all the four simple deformations. The constitutive model has a simple form, which facilitates to study the effective mechanical behaviors of the composites in both the time and frequency domains. The representative volume element (RVE) models with different fiber volume fractions are created to simulate the effective viscoelastic behaviors of the fiber-reinforced composites. The comprehensive numerical simulation results reveal that the constitutive model can offer quite consistent effective mechanical responses with the finite element simulations. The experimental results in the literature are also employed to validate the constitutive model, and the findings show that the constitutive model can offer satisfactory prediction accuracy. [ABSTRACT FROM AUTHOR]

For the development of self-assembly donor-σ-acceptor (D-σ-A) molecules, a series of D-σ-A low-molecular mass organogelators, consisting of tetrathiafulvalene (D) and cyanobiphenyl (A) connected by a thioalkanoyloxy spacer of varying lengths modified with hydrophobic chains incorporating amide groups on the side, was designed and readily synthesized. Their gelation properties were studied. The results showed that the gelation capability of these compounds was highly dependent on the alkyl chain length in the spacer group and the TTF and cyanobiphenyl units. Derivative 1a with short alkyl chain (n = 4) efficiently gelated in some aromatic solvents, forming opaque organogels. These gelators reacted with F4TCNQ to form stable charge-transfer complex gels in ethanol. Clear evidence of self-assembled micro/nanoflower, fibrous, or tubular morphologies in gelation state was obtained by scanning electron microscopy. It was found that the molecules adopted lamellar and rectangular columnar molecular packing models in the gel phase by X-ray diffraction. The native gels underwent a reversible gel-sol phase transition upon exposure to external stimuli. The gel-sol transition of the organogel was stimulated by the addition of fluoride anions. Interestingly, all gels showed an irreversible gel-sol transition triggered by TFA and TEA. The formation of flower-like morphologies of TTF-based derivatives in the gel state was observed. [ABSTRACT FROM AUTHOR]

The deformation behaviour of the austenitic and ferritic phases in an aged duplex stainless steel is investigated experimentally and numerically. The effect of the ferritic phase's spinoidal decomposition during thermal ageing on the mechanical behaviour of the alloy is studied through micropillar compression tests on the individual single crystal phases before and after ageing, and APT and TEM investigations of the decomposed ferrite and corresponding dislocation structures. Dislocation density-based crystal plasticity models are formulated for the austenitic and ferritic phases, and calibrated from the measured micropillars responses. A considerably higher and more homogeneously distributed initial dislocation density is observed in the austenite, resulting in a more homogeneous deformation of the austenitic micropillars than the ferritic ones. The spinoidal decomposition of the ferrite leads to a considerable increase of its initial flow stress. The strengthening effect of thermal ageing and the resulting localised deformation response of the aged ferritic micropillars are correctly described by the crystal plasticity results, which required a higher initial obstacle (dislocations + inter-phases of the newly formed α ′ domains) density to dislocation motion. Moreover, a strong size effect was observed on the behaviour of the as-received and aged austenitic and as-received ferritic micropillars, but not in the aged ferritic ones. Such contrasting behaviour originates from the fact that, for the size sensitive cases, the dislocation mean free path is controlled by the mean micropillar diameter, whereas in the aged ferrite micropillars, it is by the ∼ 5 nm wide Cr-rich domains within the spinoidal decomposed ferrite. [Display omitted] [ABSTRACT FROM AUTHOR]

• Hydro operations led to 56.8% decrease in sediment load in upper Yangtze River. • The construction of cascade hydropower reduced the sediment concentration by 56.6%. • Changes in sediment transport and high flow pulses reduce spawning abundance. • The effect of flooding processes on spawning abundance was not significant. • Novel methodology analysed the effects of cascade hydropower on fish spawning. The upper reaches of the Yangtze River (YR) constitute the largest group of hydropower cascade projects in the world. The construction of cascade hydropower systems has a significant impact on the flow regimes and sediment transport in rivers, ultimately affecting fish spawning. Previous studies have examined the effects of fluctuating flow and water temperature on spawning; however, insufficient attention has been paid to their effects on sediment transport. This study analysed changes in runoff and sediment load (SL) at the Xiangjiaba hydrologic station (XJB) and Zhutuo hydrologic station (ZT) in the upper reaches of the YR over the past 60 years. Based on the indicators of hydrological regimes and sediment transport, we used the generalized additive models (GAM) to investigate the effects of cascade hydropower operations from 2009 to 2018 on the spawning abundance of Coreius heterodon (C. H) in the upper YR Fish Reserve. Following the operation of cascade hydropower, the SL and sediment concentration decreased by 56.8% and 56.6%, respectively, while the median size of the bed-material load demonstrated an initial thinning trend followed by subsequent coarsening. In addition, the frequency of the high-flow pulse increased by 32.1%, whereas the peak flow and duration of the high-flow pulse decreased by 41.2% and 62.6%, respectively. However, no significant changes were noted in the indicators of the flooding process. The decrease in sediment transport and changes in the flow regime led to a reduction in the spawning abundance of C. H. Reductions in sediment transport and changes in high-flow pulses caused by cascade hydropower can negatively affect C. H spawning, and SL is the most important indicator of impacts on spawning abundance (contribution of 77.7%). These findings are critical for evaluating the long-term impacts of cascade hydropower on fish habitats. [ABSTRACT FROM AUTHOR]

• Stage change during seasonal extreme streamflow exhibited more evident adjustments. • Phase variation of ENSO dominated the interannual dynamics of extreme streamflow. • Extreme streamflow anomalies mainly occurred in the decay year of ENSO events. • Dams altered the timing and seasonal changing patterns of extreme streamflow. Climate change has led to anomalous fluctuations in extreme streamflow from global river systems, and the superposition of human activities such as damming has compounded the changes in extreme streamflow, affecting floods and river ecosystems. However, muti-temporal scale variations of extreme streamflow and the dominant driving factors were limitedly understood. In this study, we examined the changing patterns of inter- and intra-annual extreme (maximum 1-day, consecutive 3-days and 7-days) streamflow (including magnitude and timing) in the Yangtze River Basin (YRB) from the 1940 s to 2020. Furthermore, the roles of ENSO events and dams on temporal anomalies of extreme streamflow at inter- and intra-annual scales were identified in the whole basin. We found that the annual streamflow extremes increased in the source YRB and the middle and lower YRB but decreased in the upper YRB. The extreme streamflow during spring and autumn was characterized by increasing trends in the source and decreasing trends in other reaches. The occurrence timing of winter extreme streamflow in the upper and middle YRB was significantly delayed. The inter-annual extreme streamflow in the source and upper YRB had a negative relationship with ENSO, while the positive relationship held in the middle and lower YRB. The major anomalies (>50 %) of annual extreme streamflow generally occurred in ENSO (1+2) yrs, while precipitation contributes to the seasonal distribution of extreme streamflow. There was a good correlation between precipitation and both annual and summer extreme streamflow in the lower YRB, but the relationship completely shifted in the upper YRB after 2003. Further, the construction of dams has severely affected extreme streamflow, leading to a stepwise drop in annual and summer/autumn flows and a sudden rise in spring/winter flows. This study facilitates the prediction of extreme streamflow and the development of sustainable basin management strategies. [ABSTRACT FROM AUTHOR]

Background: Discovering potential predictive risks in the super precarcinomatous phase of hepatocellular carcinoma (HCC) without any clinical manifestations is impossible under normal paradigm but critical to control this complex disease.Methods: In this study, we utilized a proposed sequential allosteric modules (AMs)-based approach and quantitatively calculated the topological structural variations of these AMs.Results: We found the total of 13 oncogenic allosteric modules (OAMs) among chronic hepatitis B (CHB), cirrhosis and HCC network used SimiNEF. We obtained the 11 highly correlated gene pairs involving 15 genes (r > 0.8, P < 0.001) from the 12 OAMs (the out-of-bag (OOB) classification error rate < 0.5) partial consistent with those in independent clinical microarray data, then a three-gene set (cyp1a2-cyp2c19-il6) was optimized to distinguish HCC from non-tumor liver tissues using random forests with an average area under the curve (AUC) of 0.973. Furthermore, we found significant inhibitory effect on the tumor growth of Bel-7402, Hep 3B and Huh7 cell lines in zebrafish treated with the compounds affected those three genes.Conclusions: These findings indicated that the sequential AMs-based approach could detect HCC risk in the patients with chronic liver disease and might be applied to any time-dependent risk of cancer. [ABSTRACT FROM AUTHOR]

Ferrihydrite (Fh) has been demonstrated acting as a hole‐storage layer (HSL) in photoelectrocatalysis system. However, the intrinsic structure responsible for the hole storage function for Fh remains unclear. Herein, by dehydrating the Fh via a careful calcination, the essential relation between the HSL function and the structure evolution of Fh material is unraveled. The irreversible and gradual loss of crystal water molecules in Fh leads to the weakening of the HSL function, accompanied with the arrangement of inner structure units. A structure evolution of the dehydration process is proposed and the primary active structure of Fh for HSL is identified as the [FeO6] polyhedral units bonding with two or three molecules of crystal water. With the successive loss of chemical crystal water, the coordination symmetry of [FeO6] hydration units undergoes mutation and a more ordered structure is formed, causing the difficulty for accepting photogenerated holes as a consequence. [ABSTRACT FROM AUTHOR]

Ferrihydrite (Fh) has been demonstrated acting as a hole‐storage layer (HSL) in photoelectrocatalysis system. However, the intrinsic structure responsible for the hole storage function for Fh remains unclear. Herein, by dehydrating the Fh via a careful calcination, the essential relation between the HSL function and the structure evolution of Fh material is unraveled. The irreversible and gradual loss of crystal water molecules in Fh leads to the weakening of the HSL function, accompanied with the arrangement of inner structure units. A structure evolution of the dehydration process is proposed and the primary active structure of Fh for HSL is identified as the [FeO6] polyhedral units bonding with two or three molecules of crystal water. With the successive loss of chemical crystal water, the coordination symmetry of [FeO6] hydration units undergoes mutation and a more ordered structure is formed, causing the difficulty for accepting photogenerated holes as a consequence. [ABSTRACT FROM AUTHOR]

The changes in fractal structure during high-temperature (1200°C) carbonisation of a Chinese non-caking coal were studied in situ by synchrotron radiation small-angle X-ray scattering (SAXS). The results indicate that the raw coal, char and carbon residue possess a surface fractal structure, and a change in fractal dimension during carbonisation indicates that the process exhibits different stages. Changes in the fractal dimension and the various mechanisms during carbonisation are revealed and analysed. [ABSTRACT FROM AUTHOR]

Full-range strain hardening behaviour, containing the post-necking stage, is difficult to account for in detail. Hence, a Swift–Voce (S–V) model was used to describe the full-range stress–strain behaviour of 7050-T7451 aluminium alloy under uniaxial-tension, tension-with-notch and pure-shear processes with a hybrid experimental-numerical framework. Since the S–V model is not able to describe accurately the behaviour of Ti–6Al–4V alloy, a combined Swift and 4th degree polynomial (S-P4) model is proposed. Results indicate that the S–V model can successfully describe large-deformation behaviour of the 7050-T7451 aluminium alloy, and the S-P4 model can successfully describe that of the Ti–6Al–4V alloy based on careful designing process of the constitutive equation. [ABSTRACT FROM AUTHOR]

Structure evaluation was comparably studied with the traditional thin anode‐supported solid oxide fuel cells based on single‐sided electrolyte (SSE‐SOFCs) and the thick flat‐tube solid oxide fuel cells based on double‐sided electrolytes (DSE‐SOFCs) under redox conditions. Results showed that the structure of DSE‐SOFCs remained unchanged, especially the electrolyte kept un‐cracked during the redox process, whereas SSE‐SOFC was warped and, in some cases, cracked as the thickness of supported anode was less than 1 mm, which indicated that the DSE‐SOFCs exhibited better redox stability than the SSE‐SOFCs. [ABSTRACT FROM AUTHOR]

A series of ethylenedithiotetrathiafulvalene (EDT-TTF) compounds with cyanobiphenyl moieties attached with different length alkyl chains has been designed and synthesized. The phase behavior of these derivatives was investigated by a combination of polarizing optical microscopy, differential scanning calorimetry, and X-ray diffraction. Among the derivatives, the derivatives with spacer group lengths of n = 6–12 (3b–3d) show a distinct glassy transition during the heating and cooling processes, and 3c (n = 8) and 3d (n = 12) show liquid crystal (LC) phases below the isotropic temperature. An electrochemical study shows that the longer the spacer group, the more readily the target compound is oxidized. Density functional theory calculations show that the LC molecules are typical donor–σ-bridge–acceptor molecules. [ABSTRACT FROM AUTHOR]

As one of the typical nanostructures, nanotwins (NTs) have been utilized to evade the trade-off between strength and ductility, which is also applicable to improve the mechanical properties of superalloys. However, the optimization capability of mechanical properties by tailoring NTs has encountered bottleneck for the reasons such as inverse Hall-Petch effect and anisotropic effect. Based on the experimental observation of a special distribution pattern of NTs and nano-precipitates (NPs) in superalloys, that is, NPs are located at the twin boundaries (TBs), our work aims to study the distinctive synergistic deformation mechanism between NTs and NPs, which could become a new microstructure design strategy to optimize the mechanical properties of superalloys. Specifically, molecular dynamic (MD) method was employed to unveil the synergistic deformation mechanism of NTs and NPs in a model Ni-based superalloy. As expected, the introduction of NPs onto TBs can inhibit dislocation motion along or parallel to TBs, despite the softening deformation mode of NTs is activated. Moreover, the existence of NPs onto TBs can greatly improve the strengthening efficiency of NTs by impeding twin thickening/thinning. On the other hand, both phase boundaries and NPs interior have obstructive effect on dislocation motion, which could also be beneficial for material strengthening. More interestingly, anti-phase boundary (APB) structure will form along with the dislocations cutting through NPs. Subsequently, the APB structure can act as channels for dislocation slip and dislocation nucleation site induced by a kind of TB confinement effect, which may effectively accommodate plastic deformation. Our research outcomes could be utilized to facilitate the development of high-performance superalloys via rational collaborative design of NTs and NPs. [Display omitted] • The anisotropy of mechanical properties and deformation mechanisms of nano-precipitates and nanotwins are investigated. • The synergistic effect of nano-precipitates and nanotwins can enhance twin spacing dependent Hall-Petch strengthening. • The nano-precipitates located at the TBs can impede the migration of TBs, and thus relieve softening deformation behavior. • The APB structure can serve as the nucleation site and/or slip channel of dislocations with the confinement effect of TBs. [ABSTRACT FROM AUTHOR]

Small Angle X-ray Scattering (SAXS) is a common physical method to characterize the structure of materials on the nanoscale. The absolute scattering intensity contains quantitative information related to the mass and density of materials. We studied the absolute scattering intensity calibration method on the 1W2A SAXS station at Beijing Synchrotron Radiation Facility (BSRF) with standards such as glassy carbon and water, and further applied the method to determine the molecular weight of ovalbumin and the porosity of anthracite coal during pyrolysis. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) as an endocrine-disrupting chemical with weak estrogenic activity affects formation of primordial follicles. This study aimed to identify the potential effects and molecular mechanisms of BPA on meiosis and primordial follicle formation in chickens. The results suggest that the cortical layer was thickened and the number of germ cells that entered into meiosis was increased in BPA-treated ovaries. The percentage of γH2AX-positive cells increased significantly. In addition, up-regulated mRNA expression of meiotic genes, including stimulated by retinoic acid gene 8 ( Stra8 ), disrupted meiotic cDNA 1 homologue ( Dmc1 ) and synaptonemal complex protein 3 ( Scp3 ) were observed in BPA-treated ovaries. Therefore, progression to meiosis prophase I was accelerated by exposure to BPA. Furthermore, the results demonstrated that injection of BPA resulted in hypomethylation of Dazl (Deleted in A Zoospermia-Like gene) and Stra8 and up-regulation mRNA expression of Dazl and Stra8 during meiotic onset. Finally, the relationship between estrogen receptor (ER) expression and BPA-induced meiosis was revealed using an in vitro ovarian culture system. BPA enhanced ERβ expression at the levels of mRNA and protein, while BPA exerted no significant effect on ERα and membrane-bound estrogen receptor ( GPR30 ) expression. The inducing effects of BPA on meiosis were blocked by ER inhibitor. Collectively, these results demonstrate the dynamic ovarian response to BPA exposure, which indicate that BPA affects the formation of primordial follicles by promoting meiotic progression of oocytes via hypomethylation of Dazl and Stra8 and ERβ signaling pathways. [ABSTRACT FROM AUTHOR]

Vehicular sensor networks have been widely applied in intelligent traffic systems in recent years. Because of the specificity of vehicular sensor networks, they require an enhanced, secure and efficient authentication scheme. Existing authentication protocols are vulnerable to some problems, such as a high computational overhead with certificate distribution and revocation, strong reliance on tamper-proof devices, limited scalability when building many secure channels, and an inability to detect hardware tampering attacks. In this paper, an improved authentication scheme using certificateless public key cryptography is proposed to address these problems. A security analysis of our scheme shows that our protocol provides an enhanced secure anonymous authentication, which is resilient against major security threats. Furthermore, the proposed scheme reduces the incidence of node compromise and replication attacks. The scheme also provides a malicious-node detection and warning mechanism, which can quickly identify compromised static nodes and immediately alert the administrative department. With performance evaluations, the scheme can obtain better trade-offs between security and efficiency than the well-known available schemes. [ABSTRACT FROM AUTHOR]

Non-destructive imaging strategies to monitor long-term cultures is essential for vascular engineering. The goal of this study is to investigate whether optical coherence tomography (OCT) can be a suitable approach to monitor the long-term remodeling process of biodegradable polymeric scaffold-based tissue-engineered vascular grafts (TEVG) after pulsatile stimulation and to observe polymeric scaffold degradation during bioreactor cultivation. In the present study, a perfusion system driven by a ventricular assist device was provided for a three-dimensional culture system as a pulsatile force. We characterized the structural features of wall thickness and polyglycolic acid degradation based on optical signal attenuation using catheter-based OCT. Scanning electron microscopy confirmed morphological changes. Also, polymer degradation and the detection of different types of collagen was visualized after 4 weeks of culture by means of polarized microscopy. Findings on OCT imaging correlated with those on histological examination and revealed the effects of pulsatile stimulation on the development of engineered vessels. This finding demonstrated that real-time imaging with OCT may be a promising tool for monitoring the growth and remodeling characterization of TEVG and provide a basis to promote the ideal and long-term culture of vascular tissue engineering. [ABSTRACT FROM AUTHOR]

Fecal contamination from sewage and agricultural runoff has been a prevailing problem in coastal watersheds owing to accelerating human stressors and climate change in the Anthropocene. However, the patterns and drivers of fecal indicator bacteria (FIB) exports in typhoon-affected watersheds remain poorly understood. Here, the spatiotemporal variation of FIB and its drivers were systematically investigated in a subtropical coastal watershed, namely the Jiulong River Watershed (JRW), by integrating a decade of monthly in-situ observations and applying them to the Soil and Water Assessment Tool (SWAT) model. The SWAT model was calibrated and validated for streamflow and fecal coliform (FC) simulations with satisfactory performance (Nash-Sutcliffe Efficiency of 0.69 and 0.47, R2 of 0.72 and 0.60 for streamflow and FC in validation period, respectively). Observations of FC in both the North River (220–5580 cfu·100 mL−1) and the West River (3649–46,293 cfu·100 mL−1) of the JRW showed significant declining trends from 2010 to 2020. Source attribution analysis of FC export indicated that livestock manure emissions were the largest contributor (>60%) with urban domestic sewage being the least important contributor (<5%). Furthermore, our observation and modeling results show that FC exports were markedly enhanced during high rainfall events and typhoons, while FC exports decreased during the winter when the climate is dry and cold. The FC loads ranged from 2.6 × 107 to 2.8 × 1010cfu∙L−1∙s−1, with the average loads in agriculture, nature, and urban watershed accounting for 6.3 × 109, 8.3 × 108, and 7.4 × 109cfu∙L−1∙s−1, respectively. Our data support that the FC loads are closely related to anthropogenic indicators and are significantly higher in urban and agricultural watersheds than in natural or pristine watersheds. Future climate change with more frequent rainfall extremes will likely intensify FC exports. Such findings have important implications regarding mitigating FIB pollution for subtropical coastal watersheds under the context of climate change and increasing human impacts. [ABSTRACT FROM AUTHOR]

• Extreme streamflow and sediment load decreased during 1956–2019, but increased or stabilized since 2000. • Mainstream dams reduced synchronization probability of extreme streamflow and sediment load. • Soil conservation measures reduced extreme streamflow and sediment load in power function. In recent decades, the increasing frequency and magnitude of extreme hydrological events due to climate change and human activities have caused substantial economic losses and damages to human wellbeing. Here, we investigated the spatiotemporal variations of streamflow extremes (QE) and sediment load extremes (SE) in the Yellow River (YR) during 1956–2019. Furthermore, the effects of main human activities and climate change were identified by establishing quantitative relationships between these factors and changing hydrological extremes. Specifically, the QE and SE have decreased significantly (p < 0.05) since 1956 except the headwater (reach above Tangnaihai). However, the QE increased significantly (p < 0.05) during 2000–2019 due to increased extreme precipitation, while the SE tended to stabilize at most stations. Besides, the contribution of QE to annual streamflow declined distinctly in the upper-middle reaches (Lanzhou-Tongguan reach) but increased significantly in the lower reaches (reach below Huayuankou). Likewise, the contribution of SE to annual sediment load increased remarkably in the middle-lower reaches (Huayuankou-Lijin reach). Furthermore, the timing of QE and SE generally tended to disperse from the flood season to the four seasons. While extreme precipitation fundamentally caused the extreme water and sediment discharge, the magnitude and hazard of QE and SE can be strongly regulated by human activities. Particularly, mainstream dams can artificially regulate QE and SE magnitudes and relationships and reduce their synchronization probability, and intra-basin engineering construction and revegetation measures can substantially reduce their possible peaks in a power function form. In addition, changes in the extreme water–sediment relationships indicated that declining erosive power in the middle reaches and decreasing sediment availability in the lower reaches dominated SE reduction. This study provides a scientific basis for flood risk management and water resources development and utilization in large complex river basins. [ABSTRACT FROM AUTHOR]

Regulation of skeletal muscle development requires many of the regulatory networks that are fundamental to developmental myogenesis. ErbB3 binding protein-1 ( Ebp1) is involved in the control of myoblasts development in chicken. However, the expression and biological functions of Ebp1 in the progress of myogenesis are unclear. This study focused on determining the effect of Ebp1 on myogenic proliferation and differentiation using a primary myoblasts culture model. Ebp1 was found to upregulate in proliferating myoblasts and decrease at the early stage of myogenic differentiation. The level of endogenous Ebp1 increased from E9 to E20 chicken leg muscles. Knockdown of Ebp1 had no effect on myoblasts proliferation. However, myogenic differentiation into multinucleated myotubes was significantly reduced. The mRNA and protein expression of MRFs was decreased when Ebp1 was knocked down. Downregulation of Ebp1, accompanied by elevated levels of pSMAD2/3, suggests that Ebp1 is involved in regulating myogenic differentiation via SMAD2/3 inhibition. The phosphorylation of SMAD2/3 was activated and the expression of MYOD and MYOG was reduced in Ebp1 knockdown myoblasts, but addition of LY2109761 (an inhibitor specified to SMAD2/3) blocked these effects. Collectively, these results indicate that Ebp1 promotes myoblast differentiation by inhibition of SMAD2/3 signaling pathway during chicken myogenesis. These data provide new insights into the biological role of Ebp1 in embryonic chicken skeletal muscle development. [ABSTRACT FROM AUTHOR]

Gliomas are the most common and aggressive brain tumors, and a poor prognosis is correlated with its World Health Organization (WHO) grade. MicroRNAs (miRNAs) may serve as diagnostic and prognostic biomarkers in gliomas. In the present study, we collected plasma samples from patients with gliomas to evaluate the expression of miR-122 and analyzed the role of miR-122 in the diagnosis and prognosis of gliomas. We found that the expression of miR-122 in the plasma of patients with gliomas was significantly down-regulated compared to that in healthy individuals. In addition, the expression of miR-122, which was significantly correlated with WHO grade, decreased along with the development of gliomas. A receiver operating characteristic curve analysis showed high sensitivity and specificity of miR-122 for diagnosing gliomas (sensitivity 91.9%; specificity 81.1%; area under the curve 0.939). Finally, we found that lower expression of miR-122 was correlated with poor prognosis, and miR-122 was an independent prognostic parameter indicating poor prognosis for gliomas. In conclusion, our results showed that plasma miR-122 expression might act as a diagnostic and prognostic biomarker for gliomas. [ABSTRACT FROM AUTHOR]

[Display omitted] • BDNF via its receptor TrkB enhances the excitability and decreases the membrane input resistance and membrane time constant of song premotor nucleus RA projection neurons in adult male zebra finches. • BDNF via TrkB increases the excitatory synaptic transmission of RA projection neurons through presynaptic mechanisms. • These findings suggest a possible cellular mechanism of BDNF regulating song behavior of songbirds. The singing of songbirds is a complex vocal behavior. It was reported that brain-derived neurotrophic factor (BDNF), a key neurotrophic factor involved in neuronal survival and activity, plays an important role in regulation of songbirds' song behavior. In all song-related nuclei, the electrophysiological activity of robust nucleus of the arcopallium (RA) in the forebrain of songbirds is directly related to birdsong output. Whether BDNF regulates the electrophysiological activity and synaptic transmission of RA causing the change of song behavior need be further explored. In this study, the effects of BDNF on the electrophysiological activity and excitatory synaptic transmission of RA projection neurons (PNs) in adult male zebra finches were investigated using whole-cell patch clamp recordings in vitro. Our results showed that BDNF increased the firing of evoked action potentials in RA PNs and decreased the membrane input resistance and membrane time constant of RA PNs, indicating that BDNF can promote RA PNs excitability by reducing membrane input resistance and membrane time constant. Meanwhile, BDNF increased the frequency rather than amplitude of miniature excitatory postsynaptic currents (mEPSCs) in RA PNs. Moreover, the effects of BDNF on the excitability, intrinsic membrane properties and mEPSCs of RA PNs were blocked by its receptor TrkB antagonist K252a. These results indicate that BDNF via TrkB enhances the excitability and excitatory synaptic transmission of RA PNs in adult male songbirds through presynaptic mechanisms, suggesting a possible cellular mechanism by which BDNF regulates song behavior. [ABSTRACT FROM AUTHOR]

The intergranular corrosion in a partially recrystallized 2A97 Al-Cu-Li alloy at various tempers was investigated. Immersion tests showed that the T6-tempered alloy was susceptible to intergranular corrosion (IGC) and intersubgranular corrosion (ISGC), and local corrosion preferentially initiated and propagated at subgrain boundary. The IGC and ISGC sensitivity decreased notably in the T8-tempered alloy and intragranular pitting dominated the corrosion in this case. The precipitates and solutes distribution at grain and subgrain boundary in T6- and T8-tempered alloy were characterized by TEM, STEM-EDX and APT to address the key influencing factor to the localized corrosion. ● Subgrain boundary is more sensitive to corrosion than grain boundary at T6 temper. ● Locally enriched Al 2 Cu phase on subgrain boundary facilitates local corrosion. ● Pre-stretching decreases the corrosion susceptibility of grain and subgrain boundary. ● Cu-rich film protects grain boundary from being attacked at T8 temper. [ABSTRACT FROM AUTHOR]

With the increase of heat treatment temperature, the angle between the fiber axis and the long axis of the pore decreases, the parallelism between the pores become more orderly, the short axis increases and the long axis decreases. [Display omitted] • In-situ SAXS study on the fractal structure change of a kind of pitch-based carbon fiber during HTT (1200 °C ∼ 1700 °C). • From the meridional to equatorial directions, carbon fiber exhibit pore and surface fractal at low (μ ≤ 71°) and high (μ ≥ 73°) azimuth angles, respectively. • During HTT from 1200 °C to 1700 °C, the fractal dimension gradually increases near the meridian direction, decreases in the equatorial direction, and first decreases and then increases in other directions. • Both pore fractal and surface fractal dimension gradually increase with increasing azimuth angle. High-temperature treatment (HTT) is a vital process to change the structure and improve the performance of pitch-based carbon fiber. The complexity of pore structure and their change during heating can be described by a mathematical concept of fractal. This short contribution reports an in-situ synchrotron radiation small angle X-ray scattering (SAXS) study on the fractal structure change of a kind of pitch-based carbon fiber during heating from 1200 °C to 1700 °C with Joule effect in a small furnace. The change of the fractal structure at different azimuth angles with temperature is revealed, and the corresponding mechanism is analyzed. [ABSTRACT FROM AUTHOR]

• Variations in cross-sections and planimetric morphology are investigated for steady bars and migrating bars. • The dominant discharge range controlling bar adjustments is identified to be 12,500 m3/s to 27,500 m3/s. • Changes in flow, sediment supply and vegetation jointly regulate bar changes. Dams alter downstream river flow and sediment regimes, causing significant changes in river morphologies. The middle Yangtze River downstream of the Three Gorges Dam (TGD) has experienced rapid erosion in recent years, and the associated morphodynamic changes have negatively impacted the riverbank stability, navigation waterways and ecological functioning. Earlier studies have analyzed recent channel adjustments in the Yangtze River; however, our understanding of changes in the bar morphodynamics remains incomplete. In this study, we collected and analyzed flow and sediment data (1991–2016) and river bathymetry data (1975–2017) and investigated the mechanisms of bar adjustments along the Jingjiang Reach in the post-TGD period. The results indicate that most steady bars with a higher elevation and better vegetation coverage have experienced lateral erosion, while their elevations have remained stable overall. The unvegetated migrating bars with a lower elevation have experienced severe surficial erosion and area shrinkages. A new assessment method of the dominant discharge range on downstream bars is provided after dam closure. The dominant discharge range that determines bar adjustments corresponds to the flow stages between the submersion of migrating bars (∼12,500 m3/s) and the overtopping of vegetated steady bars (∼27,500 m3/s) in the Jingjiang Reach. A quantitative relationship exists between bar erosion in response to changed dominant discharge regimes and sediment decline. The significant bar erosion after the operation of the TGD can be attributed to the increased flow duration and the sharp decline in the suspended sediment concentration (SSC) of the dominant discharge range, and changes in SSCs play a primary role. The bar area will decrease by ∼0.003 km2 when the annual cumulative duration of the dominant discharge increases by one day and by ∼0.234 km2 when the annual average SSC of the dominant discharge decreases by 0.01 kg/m3. Furthermore, vegetation encroachment and colonization play a positive role in stabilizing bar morphologies and limiting surficial erosion, whereas vegetation soley cannot prevent the lateral erosion of steady bars. These findings suggest that multiple controls of discharge, sediment and vegetation on the evolution of fluvial bars and have important implications for river management and ecological evaluation in response to the operation of large dams. [ABSTRACT FROM AUTHOR]

A novel, silicon-linked, symmetric, V-shaped, coumarin derivative ( 1 ) with an electron-deficient 1,3,4-oxadiazoles unit and a phenyl moiety was synthesized and characterized. An efficient multifunctional organic light-emitting diode material was obtained through the use of optical, electrochemical, thermal, and theoretical investigations. We show that the Si atom induces a V-shaped structure that weakens π–π stacking and thus limits aggregation-induced quenching. As expected, a gradual transition from a locally excited state to an intramolecular charge-transfer state is observed with increasing solvent polarity. This new type of compound exhibits tunable light emission in solution making it a versatile emitter. [ABSTRACT FROM AUTHOR]

The reactions of tricyanometallate precursors, (Ph3PMe)[(Tp4-Me)Fe(CN)3·0.5CH3CN] (1) (Tp4-Me = tri(4-methyl-pyrazol-1-yl)borate) and (NBu4)[(MeTp)Fe(CN)3] (MeTp = methyltris(pyrazolyl)borate) with the presence of the tetradentate tpa ligand (tpa = tris(2-pyridylmethyl)amine) and Fe(ClO4)2·6H2O afford two new cyano-bridged mixed-valence {FeIII2FeII2} molecular squares: [(Tp4-Me)FeIII(CN)3]2[FeII(tpa)]2·2ClO4·H2O (2·H2O) and [(MeTp)FeIII(CN)3]2[FeII(tpa)]2·2ClO4·CH3OH (3·CH3OH). Solvent-exchange compounds of 3·CH3OH, [(MeTp)FeIII(CN)3]2[FeII(tpa)]2·2ClO4·2H2O (3·2H2O), and their solvent-free form (2 and 3) are also obtained, respectively. The spin crossover (SCO) properties of all compounds are confirmed by detailed structural analyses of the coordination environments of the FeII centres and magnetic susceptibility measurements. All compounds exhibit SCO behaviour near room temperature (T1/2 = 320 K for 2·H2O; 302 K for 2; 292 K for 3·CH3OH; 306 K for 3·2H2O and 290 K for 3) and reversible single-crystal to single-crystal (SC–SC) transformations induced by guest desorption and resorption or solvent exchange. The transition temperature close to room temperature can be tuned by the dehydration and re-hydration processes. The structure–property analysis discloses that the distorted {Fe4(μ-CN)4} core and deviations of bent 〈Fe−N≡C angles play a key role in tuning the transition temperature of these similar mixed-valence {FeIII2FeII2} complexes. [ABSTRACT FROM AUTHOR]

Landslide is a hazard that has drastic repercussions on population and the environment worldwide. Landslide susceptibility mapping (LSM) is vital for landslide disaster management and formulating mitigation strategies. In this study, with the support of geographic information system and remote sensing, a new LSM hybrid framework is developed based on random forest (RF) and cusp catastrophe model (CCM). Under the framework, 15 conditioning factors and 2082 historical landslides are selected to test and compare its performance in a landslide-prone area in Liangshan, Southwest China. The results depicted a better performance of the new LSM hybrid framework (RF-CCM) than those of RF or traditional application mode of catastrophe model (Catastrophe fuzzy membership functions, CFMFs) only. The RF-CCM achieved the highest accuracy (0.901), the narrowest confidence interval (0.895–0.907), and the smallest standard error (0.004) among all the models. Notably, RF-CCM successfully decreased the uncertainty of CFMFs in determining the relative importance of conditioning factors, overcame the dependence of the CFMFs on independence among the conditioning factors, and had a higher stability level than RF. Moreover, distance to human engineering activities and slope had the greatest impact on LSM in the modeling process. The study result can provide insights for developing reliable predictive models for other landslide-prone areas with similar geo-environmental conditions. • The spatial database of 15 conditioning factors is constructed. • A novel framework (RF-CCM) is developed for landslide susceptibility mapping. • The RF-CCM has the best performance in comparison to RF and CFMFs. • It reveals the importance of driving factors and their categories for landslides. [ABSTRACT FROM AUTHOR]

The effects of human activity on geomorphic processes, particularly those related to denudation/sedimentation, are investigated by reviewing case studies and global assessments covering the past few centuries. Evidence we have assembled from different parts of the world, as well as from the literature, show that certain geomorphic processes are experiencing an acceleration, especially since the mid-twentieth century. This suggests that a global geomorphic change is taking place, largely caused by anthropogenic landscape changes. Direct human-driven denudation (through activities involving excavation, transport, and accumulation of geological materials) has increased by a factor of 30 between 1950 and 2015, representing a ten-fold increase of per capita effect. Direct plus indirectly human-induced denudation (triggered by land surface alteration) is presently at least one order of magnitude greater than denudation due to purely natural processes. The activity of slope movements, which represent an important contribution to denudation, sediment generation and landscape evolution, also shows a clear intensification. Frequency of hazardous events and disasters related to slope movements (an indirect measure of process frequency) in specific regions, as well as at continental and global levels, has grown considerably, in particular after the mid-twentieth century. Intense rainstorm events are often related to slope movement occurrence, but the general increasing trend observed is not satisfactorily explained by climate. Sedimentation has augmented considerably in most regions and all kinds of sedimentation environments. Although the link between denudation and sedimentation is not direct and unequivocal, it is safe to assume that if sedimentation rates increase in different regions during a given period, denudation must have increased too, even though their magnitudes could be different. This augmentation, particularly marked from the second half of the last century onwards, appears to be determined mainly by land surface changes, in conjunction with climate change. The changes observed suggest: a) there is evidence at a global scale of a growing response of geomorphic systems to socio-economic drivers, being Gross Domestic Product density, a good indicator of the human potential to cause such impacts; b) Land use/cover changes enhance effects of climate change on global denudation/sedimentation and landslide/flood frequency, and appear to be a stronger controlling factor; c) Our findings point to the existence of a global geomorphic change. This manifestation of global change is especially evident since the "great geomorphic acceleration" that began in the middle of the 20th century, and constitutes one of the characteristics of the proposed Anthropocene. [Display omitted] • Technological denudation is presently over one order of magnitude greater than natural denudation. • Increasing trends of slope movements observed not satisfactorily explained by climate • Strong sedimentation increase in most regions and all kinds of sedimentation environments. • Increases described, particularly clear since mid-20th century, respond to land surface changes. • A global "great geomorphic acceleration" is taking place and characterizes the Anthropocene. [ABSTRACT FROM AUTHOR]

• Islands underwent 'deposition–erosion–stabilization' stages from 1989 to 2019. • Reductions in sediment and high flow duration affected bars shrinkage. • Local engineering structures maintained island stability in recent decades. Riverine islands are widespread fluvial landforms with exceptional economic and environmental values. However, anthropogenic pressures have further induced drastic changes worldwide in fluvial islands, which endanger fluvial organism habitation and enable potential ecological degradation. Here, the hydromorphodynamics on these prominent riverine landforms of the seriously regulated Upper Jinjiang reach (UJR) of the Changjiang (Yangtze) River were detected based on the Google Earth Engine (GEE) platform between 1988 and 2019. The results indicated that total vegetated islands area in the UJR experienced expansion, while bars area exhibited a dramatic decrease by 15% between 1988 and 2019. Given the total areas and their subaquatic bars' volume variations, the island's evolution could be divided into "deposition–erosion–stabilization" stages. During the deposition phase from 1988 to 1999, the bars volumes showed a gradually increasing trend, and then it shifted to erosion between 1999 and 2010. After 2010, the islands maintained stability with a total volume of approximately 177 × 106 m3. The multi-year sediment and water discharge variations contributed to the evolution of riverine islands. In particular, resulting from the Three Gorges Dam (TGD) project in 2003, the fluvial sediment load and duration of overbank discharges (25000 m3/s) decreased significantly, which were the dominant factors inducing islands with their subaquatic bars shrinkage. Recent multiple island protection projects were responsible for defending islands with their subaquatic bars against erosion and maintaining their stability. This work reveals the islands' evolution in the UJR response to the TGD effect and local artificial engineering, which is vital for managing riverine islands in global rivers affected by nature and human activities. [ABSTRACT FROM AUTHOR]

The reaction of water-soluble hydroxyl-rich salicylaldehyde Schiff base ligands with the metal salt Cu(OAc) 2 ·H 2 O affords three novel tetracopper complexes via solvothermal method: [Cu 4 (H 2 L1) 4 ]·CH 3 OH( 1 ), [Cu 4 (HL2) 2 (Py) 2 (OAc) 2 ]( 2 ), [Cu 4 (HL3) 2 (Py) 2 (OAc) 2 ]( 3 ). The X-ray crystal structures reveal the cubane Cu 4 O 4 for complex 1 with μ 3 -alkoxo bridges and quasi-stepped cubane Cu 4 O 4 for 2 and 3 bearing two central copper atoms bridged by two alkoxy groups and two peripheral copper atoms bridged with central copper atoms by one another alkoxy oxygen. Temperature-dependent magnetic measurements indicate that the dominant ferromagnetic interactions among metal ions within the cubic core of 1 with J 1 = +27.44 cm −1 , J 2 = −0.21 cm −1 ( g = 2.1157) while there are antiferromagnetic interactions between two metal centers in 3 with J 1 = −268 cm −1 , J 2 = −297 cm −1 ( g = 2.068). [ABSTRACT FROM AUTHOR]

• Axisymmetrically loaded layer-substrate system is solved analytically in polar coordinates using Hankel transform. • The discretization using annular ring is advantageous over rectangular mesh for axisymmetric contact analyses. • The CGM-based iterative scheme shows a superlinear rate of convergence for solving axisymmetric contact problems. Axisymmetric contact analysis of layered half-space is of considerable interest in many tribological applications including protective hard coating, metal-matrix composites, etc. Polonsky-Keer's iterative scheme based on conjugate gradient method (CGM) is powerful for a general three-dimensional contact problem using rectangular meshes, but would inevitably lead to excessive computational burden and inaccurate boundary discretization for axisymmetric contact. In this paper, Polonsky-Keer's CG-based iterative scheme is adapted for axisymmetric indentation of a layered elastic half-space by taking advantage of annular ring discretization, where the elementary solutions for the surface deflection and subsurface stresses can be determined with assistance of the Hankel transforms. The present method can not only effectively circumvent the discretization error, but is also versatile and flexible to solve the contact between the layered materials and an arbitrary axisymmetric indenter. Parametric studies are provided to validate the present solutions, and the comparisons of the average relative errors for different types of elements are conducted to demonstrate the excellent convergence and accuracy of the proposed numerical scheme. [ABSTRACT FROM AUTHOR]

The planar Eshelby's inclusion model has been widely applied in exploring the micromechanical behavior of fiber-reinforced composites. Based on contour integral formulation, we first present a closed-form solution to the displacement of a polygonal inclusion subjected to linear eigenstrains. In view of isoparametric representation, the resulting contributions from a triangular inclusion are conceived as the elementary solution, which may be regarded as building blocks for analyzing an arbitrarily shaped inclusion with any distributed eigenstrains. The present numerical discretization is merely performed on the inclusion domain, as opposed to the traditional Finite Element Method where the infinitely extended matrix also requires tremendous meshing efforts. • Closed-form solution of the displacements is derived for a polygonal inclusion subjected to linear eigenstrains. •Numerical scheme through boundary discretization is proposed to solve arbitrarily shaped inclusion with linear eigenstrains; •The isoparametric triangular inclusion model is versatile and powerful for handling any planar Eshelby's inclusion problem. [ABSTRACT FROM AUTHOR]

During embryonic development, IGF-1 fulfils crucial roles in skeletal myogenesis. However, the involvement of IGF-1-induced myoblast proliferation in muscle growth is still unclear. In the present study, we have characterised the role of IGF-1 in myoblast proliferation both in vitro and in vivo and have revealed novel details of how exogenous IGF-1 influences myogenic genes in chicken embryos. The results show that IGF-1 significantly induces the proliferation of cultured myoblasts in a dose-dependent manner. Additionally, the IGF-1 treatment significantly promoted myoblasts entering a new cell cycle and increasing the mRNA expression levels of cell cycle-dependent genes. However, these effects were inhibited by the PI3K inhibitor LY294002 and the Akt inhibitor KP372-1. These data indicated that the pro-proliferative effect of IGF-1 was mediated in response to the PI3K/Akt signalling pathway. Moreover, we also showed that exogenous IGF-1 stimulated myoblast proliferation in vivo. IGF-1 administration obviously promoted the incorporation of BrdU and remarkably increased the number of PAX7-positive cells in the skeletal muscle of chicken embryos. Administration of IGF-1 also significantly induced the upregulation of myogenic factors gene, the enhancement of c-Myc and the inhibition of myostatin (Mstn) expression. These findings demonstrate that IGF-1 has strong activity as a promoter of myoblast expansion and muscle fiber formation during early myogenesis. Therefore, this study offers insight into the mechanisms responsible for IGF-1-mediated stimulation of embryonic skeletal muscle development, which could have important implications for the improvement of chicken meat production. [ABSTRACT FROM AUTHOR]

Zebra finches are ideal animals to investigate sex difference in songbirds. Only males can sing. The brain nuclei controlling song learning and production in males are considerably larger than in females. The robust nucleus of the arcopallium (RA) is a premotor nucleus, playing a key role in controlling singing. RA receives denser synapse inputs in males than in females. Sex differences of excitatory synaptic transmission in the RA projection neurons (PNs) have not been reported. In the present study, using whole-cell voltage-clamp recording, spontaneous EPSCs (sEPSCs) and miniature EPSCs (mEPSCs) of RA PNs in the intact males and females were recorded. The average frequency and amplitude of sEPSCs/mEPSCs in the intact males were higher than females. The half-width and decay time of sEPSCs/mEPSCs in the intact males were longer than females. In order to verify whether these sex differences related to sex steroids, males were castrated. The average frequency of sEPSCs/mEPSCs in castrated males was lower than intact males and was similar to in females; the amplitude was not changed after castrating. These results demonstrate the sexually dimorphic of the excitatory synaptic transmission in the RA PNs, the RA PNs in males receive more excitatory synaptic transmission and these sex differences were partly affected by sex hormones. These findings contribute to further illuminate the neural mechanisms under the sexually dimorphism in song production of adult zebra finches. [ABSTRACT FROM AUTHOR]

Theelectronic structures and phosphorescent properties of a seriesof heteroleptic iridium(III) complexes (mpmi)2Ir(dmpypz)(1; mpmi = 1-(4-tolyl)-3-methylimidazolium, dmpypz =3,5-dimethyl-2-(pyrazol-3-yl)pyridine), (bpmi)2Ir(dmpypz)(2; bpmi = 1-biphenyl-4-yl-3-methylimidazole), (dfmi)2Ir(dmpypz) (3; dfmi = 1-(2,6-difluorobiphenyl)-3-methylimidazole),(mtmi)2Ir(dmpypz) (4; mtmi = 1-methyl-3-(4′-(trifluoromethyl)biphenyl-4-yl)imidazole),(fmmi)2Ir(dmpypz) (5; fmmi = 1-(fluoren-2-yl)-3-methylimidazole),and (mhmi)2Ir(dmpypz) (6; mhmi = 1-methyl-3-phenanthren-2-ylimidazole)have been investigated by using density functional theory (DFT) andtime-dependent density functional theory (TDDFT) methods. The influenceof different substituent groups and π-conjugation degrees onthe optical and electronic properties of Ir(III) complexes was alsoexplored by introducing phenyl, fluorophenyl, (trifluoromethyl)phenyl,and rigid construction on the phenylimidazole moiety of a cyclometalatedligand (C∧C) in complex 1. The calculatedresults show that the lowest energy absorption wavelengths of complexes 1–6are 387, 380, 378, 375, 391, and 384nm, respectively. The introduction of different substituent groupsleads to different degrees of red shift for complexes 2–6in emission spectra in comparison with thatof complex 1. It is believed that the highest tripletmetal to ligand charge transfer 3MLCT (%) contribution,smallest ΔES1–T1and higher μS1values,and larger 3MC–3MLCT energy gap for 3ensure its higher quantum yield in comparison with thatof other complexes. [ABSTRACT FROM AUTHOR]

Twothree-dimensional microporous compounds, Cu6(BTTC)4(H2O)6·xS (1) and [(CH3)2NH2]3[(Cu4Cl)3(BTTC)8]·yS (2, H3BTTC= benzo-(1,2;3,4;5,6)-tris (thiophene-2′-carboxylic acid),S represents noncoordinated solvent molecules), have been solvothermallysynthesized and characterized, both of which are based upon truncatedoctahedron subunits and contain uniform nanosized cavities but exhibitdifferent topological frameworks. Complex 1demonstrateshigh adsorption enthalpies for H2and CO2gasmolecules, stemming principally from the presence of the exposed metalCu(II) sites on the pore surface. In particular, activated complex 1shows high efficiency for the separation of energy-correlatedmolecules, including CO2over N2and CH4under ambient conditions. [ABSTRACT FROM AUTHOR]

Highlights: [•] We study effect of quench rate on corrosion behaviour in various over-aged alloys. [•] Corrosion resistance keeps increase with ageing time if slowly quenched. [•] Severe overageing will slightly reduce corrosion resistance if fast quenched. [•] Quenching has a much higher effect on intergranular corrosion than overageing step. [•] Copper content in precipitates is the most important factor for corrosion property. [Copyright &y& Elsevier]

Solvothermal reactions of 2,5-thiophenedicarboxylate (H2tdc) and N-auxiliary ligands in the presence of cobalt(ii), zinc(ii) and cadmium(ii) salts have given rise to seven new metal–organic frameworks, namely, [Co2(tdc)2(bpp)2(H2O)·(H2O)]n (bpp = 1,3-bis(4-pyridyl)propane) (1), [Cd(tdc)(bpp)(H2O)·(H2O)2]n (2), [Zn2(tdc)2(bbi)2·(H2O)2]n (bbi = 1,1′-(1,4-butanediyl)bis(imidazole)) (3), [Co4(tdc)3(bimb)4(H2O)5·(tdc)·(DMF)·(H2O)2]n (bimb = 4,4′-bis(1-imidazolyl)biphenyl) (4), [Zn4(O)(tdc)3(bimb)4·(H2O)5.25·(CH3OH)]n (5), [Cd4(tdc)4(bimb)6·(H2O)2·(CH3OH)2·(DMF)4] (6) and [Co2(tdc)2(tib)2·(H2tdc)·(DMF)2] (tib = 1,3,5-tris(1-imidazolyl)benzene) (7), which exhibit structural diversity. Compounds 1–3 display 3D 2-fold interpenetrating 8-connected tsi net, 2D 4-connected sql net, and 3D 5-fold interpenetrating 4-connected dia net, respectively; while compound 4 features an extremely rare 3D 7-connected hxg-d cationic net and compound 5 adopts a 3D trinodal (4,4,6)-connected net with a new topology structure. For compounds 6 and 7, the topology in the structures were determined as 3D 3-fold interpenetrating 5-connected bnn net and 3D 2-fold interpenetrating binodal (3,5)-connected net, respectively. In the solid state, complexes 1, 4 and 5 exhibit nonlinear optical properties, and complex 5 has also been evaluated as a promising visible-light-driven photocatalyst for degradation of organic pollutants. The magnetic investigation of complexes 1 and 4 shows that there exists spin-canted antiferromagnetism for 1, whereas strong antiferromagnetic interaction and/or the depopulation of the higher energy Kramers doublets of the Co(ii) centers are dominant in 4. [ABSTRACT FROM AUTHOR]