Search

Baffin Bay serves as a huge reservoir of sea ice which would provide the solid freshwater sources to the seas downstream. By employing satellite-derived sea ice motion and concentration fields, we obtain a nearly 40-year-long record (1978–1979 to 2016–2017) of the sea ice area flux through key fluxgates of Baffin Bay. Based on the estimates, the Baffin Bay sea ice area budget in terms of inflow and outflow are quantified and possible causes for its interannual variations and trends are analyzed. On average, the annual (September–August) inflows through the northern gate and Lancaster Sound are on the order of 205.8(±74.7)×103 km 2 and 55.2(±17.8)×103 km 2. In particular, a comparison with published results seems to suggest that about 75 %–85 % of the inflow through the northern gates is newly formed ice produced in the recurring North Water Polynya (NOW), in addition to the inflow via Nares Strait and Jones Sound. Meanwhile, the mean outflow via the southern gate approaches 394.3(±110.2)×103 km 2. The distinct interannual variability for ice area flux through the northern gate and southern gate is partly explained by wind forcing associated with cross-gate sea level pressure difference, with correlations of 0.62 and 0.68, respectively. Also, significant increasing trends are found for the annual sea ice area flux through the three gates, amounting to 38.9×103 , 82.2×103 , and 7.5×103 km 2 decade -1 for the northern gate, southern gate, and Lancaster Sound. These trends are chiefly related to the increasing ice motion, which is associated with thinner ice owing to the warmer climate (i.e., higher surface air temperature and shortened freezing period) and increased air and water drag coefficients over the past decades. [ABSTRACT FROM AUTHOR]

The lepidopteran crop pest Plutella xylostella causes severe constraints on Brassica cultivation. Here, we report a novel role for RPX1 (resistance to P. xylostella) in resistance to this pest in Arabidopsis thaliana. The rpx1‐1 mutant repels P. xylostella larvae, and feeding on the rpx1‐1 mutant severely damages the peritrophic matrix structure in the midgut of the larvae, thereby negatively affecting larval growth and pupation. This resistance results from the accumulation of defence compounds, including the homoterpene (3E)−4,8‐dimethyl‐1,3,7‐nonatriene (DMNT), due to the upregulation of PENTACYCLIC TRITERPENE SYNTHASE 1 (PEN1), which encodes a key DMNT biosynthetic enzyme. P. xylostella infestation and wounding induce RPX1 protein degradation, which may confer a rapid response to insect infestation. RPX1 inactivation and PEN1 overexpression are not associated with negative trade‐offs for plant growth but have much higher seed production than the wild‐type in the presence of P. xylostella infestation. This study offers a new strategy for plant molecular breeding against P. xylostella. Summary statement: Plutella xylostella pests show severely negative influence on plant growth and reproduction, and the identification of resistant genes is essential. This study reveals that inactivation of RPX1 confers significant resistance to the pest by enhancing PEN1 expression and accumulating the homoterpene DMNT in Arabidopsis thaliana. [ABSTRACT FROM AUTHOR]

Due to the stochastic grid loads and intermittent renewable energy sources in today's power grid, hydro-generator and grid system stability is increasingly dependent on the hydro-turbine governing system (HTGS). For the HTGS with external disturbances and system uncertainties, an intelligent nonlinear robust controller (INRC) based on state-dynamic-measurement feedback linearization (SDMFL) is proposed to enhance the HTGS's control performance in this paper. This strategy establishes a dynamic output function including actuator displacement, generator rotor angle, and turbine parameters. The relationship between dynamic output and control input is derived based on this function to establish the corresponding linear state-space model. Then, the mixed H 2 / H ∞ robust controller based on the linear model is designed to suppress the effects of external disturbances and system uncertainties on the system performance. In addition, the controller performance is optimized by levy flight and chaos theory-based gravitational search algorithm (LCGSA), resulting in the INRC. Simulations are performed in MATLAB, and the results are compared with the nonlinear robust controller (NRC) and PID controller. The results show that the proposed controller INRC improves the control performance of nonlinear HTGS with smaller overshoot and shorter adjustment time in all cases. • Design of nonlinear robust controller based on SDMFL method for HTGS. • Application of LCGSA algorithm for optimal tuning of NRC parameters. • Damping the speed oscillations against large fluctuations in grid power. • Excellent damping efficiency, especially, low overshoot, steady-state error, and settling time. • Study of robustness of HTGS against variations of system parameters. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel, green and environmental benign TC-AALLME-SFDES technique was developed. • Solid DES was used as extraction solvent. • The method was applied for the determination of TCS and APs from water samples. • The green profile of the method was assessed by analytical Eco-Scale and ComplexGAPI. • The method opened up the application of solid DESs in LLME technique. A novel and green microextraction technique, temperature-controlled air-assisted liquid–liquid microextraction based on the solidification of floating deep eutectic solvents (DESs), was developed and applied for the extraction of triclosan and alkylphenols in different environmental waters. Hydrophobic DESs composed of menthol and myristic acid with melting points slightly higher than room temperature (25 ± 2 °C) were prepared and used as extraction solvent. First, the solid DES was transformed into liquid DES while the aqueous sample was heated in a water bath. Then, fine droplets were formed by withdrawing and injecting the mixture of aqueous sample and DES with a 1 mL pipette several times. After extraction, the solidified DES phase was obtained in an ice water bath. And then the analyses were performed by HPLC-UV. The microextraction parameters were investigated by the Plackett-Burman design and central composite design. The analytical parameters of this method were investigated and good linear ranges (0.5/1.0–400 μg/L, R2 ≥ 0.9950), limits of detection (0.1–0.5 μg/L) and precision (≤5.9 %) were obtained. This method was successfully applied for the determination of triclosan and alkylphenols from five water samples with satisfactory recoveries (80.0–104.3 %). Subsequently, the green profile of the method was assessed by analytical Eco-Scale and Complementary Green Analytical Procedure Index. This method has the advantages of simplicity, rapidity, low cost, high sensitivity and green, which expands the application of solid solvents in liquid–liquid microextraction and has a wide application prospect. [ABSTRACT FROM AUTHOR]

Background: Intracardiac echocardiography (ICE) technology has been increasingly accepted as an integral part of atrial fibrillation (AF) ablation procedures. It is still unknown whether ICE can routinely replace transesophageal echocardiography (TEE) for routine thrombus screening in non‐selective AF patients. Objective: To assess whether ICE can routinely replace TEE in screening for left atrial (LA)/left atrial appendage (LAA) thrombus in general patients undergoing catheter ablation for AF. Methods: A total of 2003 consecutive patients undergoing AF ablation were included. 1155 patients (ICE group) received intra‐procedural ICE examination for LA/LAA thrombus screening, while 848 patients (TEE group) received pre‐procedure TEE examination. The incidence of thrombus, peri‐procedure complications, and hospital efficiency were assessed. Results: The LA and LAA were adequately visualized in all patients. Five patients in the ICE group and 15 patients in the TEE group were found to have LAA thrombus. The incidence of major periprocedural thrombo‐embolic events was comparable between two groups (0.2% vs. 0.1%, p =.76), none were due to undetected LA/LAA thrombus. Other major periprocedural complications occurred at similar rates in both groups, while post‐procedure fever was less common in the ICE group (12.7% vs. 17.4%, p <.001). Procedure times and hospital length of stay were both shorter in the ICE group (142 min [87–197 min] vs. 150 min [95–205 min], and 3[2–4] day vs. 4[3–5] day, respectively, both p <.001). Conclusions: ICE can replace TEE for atrial thrombus screening in AF patients undergoing ablation without increased complications. An "ICE replacing TEE" workflow can also reduce the incidence of postoperative fever and improve hospital efficiency. [ABSTRACT FROM AUTHOR]

• One-step derivatization and TC-VA-LLME-SFDES method was developed. • Hydrophobic DESs were used as both reducing agent and extraction solvent. • Only 2 min was needed for derivatization and extraction process. • The method was applied for analysis of total Fe in water and food samples. • The method opened up the application of solid DESs in LLME technique. In our work, hydrophobic thymol-based deep eutectic solvents (DESs) with strong reducibility, a lower density than water, and a slightly higher melting point than room temperature were synthesized. Based on these solid DESs, one-step derivatization and temperature-controlled vortex-assisted liquid-liquid microextraction based on the solidification of a floating DES (TC-VA-LLME-SFDES) via UV–Vis spectrophotometry for the rapid determination of total iron was developed. The derivatization and TC-VA-LLME were carried out simultaneously by the addition of DES as both the reducing agent and extraction solvent. After optimization, the calibration curve (5–250 μg L−1, R2 = 0.9982), limit of detection (1.5 μg L−1), limit of quantitation (5.0 μg L−1), precision (≤4.0%) and enrichment factor (92) was obtained. This method was applied for the determination of total iron in water and food samples with satisfactory recoveries (85.4–106.2%). One-step derivatization and TC-VA-LLME only required 2 min. Furthermore, this method opened up the application of solid DESs in liquid–liquid microextraction. [ABSTRACT FROM AUTHOR]

In recent years, contrastive learning has made great progress in the field of computer vision, which shows great potential in action representation learning. Current contrastive learning methods usually employ contrastive loss function to learn video motion representation, which attend to capturing the similar background appearance but ignore similar motion information. This problem is called background bias, which restricts the model from exploring motion patterns. The background bias can be divided into wide background bias and micro background bias. The wide background bias refers to the statistically significant background bias, while the micro background bias refers to the background bias directly interacting with the moving object. To tackle these problems, this paper first proposes a semi-negative pair merging foreground–background, which mainly decouples the dynamic factor with obvious motion and the static factor with stable invariants in the video frame sequence. Then the dynamic factor of the original video is fused with other static factors to obtain a random background image where the foreground is more similar than the background to solve the wide background bias. Secondly, a pixel-level motion aware representation decomposition module calculates the pixel-level intensity variations from the feature space of adjacent frames, and these variations are further accumulated to obtain the salient map that focuses on the boundaries of moving objects, so the model attends to the motion pattern rather than the background to solve the micro background bias. Furthermore, a new dual loss function is proposed based on joint wide and micro background bias to better capture both static and dynamic features. The heat map shows that the proposed method effectively can solve background bias and achieve better performance in public datasets compared with other existing methods. [ABSTRACT FROM AUTHOR]

T-shaped welded multi-partition composite members, which are made of several rectangular concrete-filled steel tubes, are proposed to speed up the fabrication procedure. Seven half-scale T-shaped specimens were tested by considering the section height-to-width ratio and slenderness ratio. In the test, a slight torsion angle was measured when the instability failure along the asymmetric axis occurred, indicating the specimens had good torsion resistance. When the relative slenderness ratio of the specimen was larger than 0.44, the specimens failed due to the instability along the asymmetric axis. Parametric numerical analysis is conducted by considering the slenderness ratio, cross-section dimension, steel ratio, and material strength. The results show that the strength of concrete negatively impacts the ductility of the specimens, leading to a decrease of 43%, while the strength of the material positively influences the stability of the specimens. The formulas from different traditional codes are verified by the parametric numerical analysis results, indicating most codes can conservatively predict the sectional bearing capacity, but overestimate the stability coefficient of the specimens by neglecting the reduction effect of the excessive height-to-depth ratio. Recommendations are provided for calculating the stability coefficient under axial compression applicable to T-shaped welded multi-partition composite members. • Axial compression of T-shaped welded multi-partition composite members was studied through experiments and FE analysis. • The measured torsion angle confirms the good torsional capacity of T-shaped composite members. • Both sectional bearing capacity and stability bearing capacity have been discussed. • A suggestion for calculating stability coefficients is proposed, which is suitable for T-shaped columns and shear walls. [ABSTRACT FROM AUTHOR]

Single measures of adiposity markers, such as body mass index (BMI) and waist circumference (WC), are associated with adverse mental health outcomes; however, long-term patterns of adiposity and their health effects remain unclear. The current study assessed adiposity trajectories during a 14-year span beyond middle age and their relevance to mental well-being in late life, and the contribution of genetic and lifestyle factors to the trajectories. Based on a nationally representative sample with longitudinal anthropometric measures, adiposity trajectories were identified by latent mixture modeling, and logistic regression model was used to estimate their associations with mental well-being, with adjustment for confounders. Of the 3491 eligible participants included (mean [SD] age, 69.5 [8.9] years), five discrete BMI and four WC trajectory patterns were identified over 14 years. Compared with the low-stable BMI group (range, 22.8 to 22.9 kg/m²; representing stable healthy body weight), the high-stable group (range, 34.3 to 35.4 kg/m²; stable obese) was associated with increased risk of depression (odds ratio [OR], 1.63; 95 % CI, 1.28–2.07) and low subjective well-being (OR, 1.35; 95 % CI, 1.02–1.79). Compared with the low-stable WC group (range, 75 to 79 cm healthy WC), the high-increasing group (range, 114 to 121 cm) was associated with increased risk of depression (odds ratio [OR], 1.64; 95 % CI, 1.19–2.25) and low well-being (OR, 1.48; 95 % CI, 1.01–2.16). The adiposity trajectories, especially the high-stable/increasing groups, were driven by genetic factors in a dose-response manner, whereas the high/moderate-increasing groups were also behaviorally related. This longitudinal cohort study reveals that stably high trajectory patterns of central and general adiposity during middle age were associated with higher risk of depression and low well-being in late life. The findings indicate the importance of weight management beyond middle age, such as adherence to a healthy lifestyle, in promoting mental health and well-being. [ABSTRACT FROM AUTHOR]

Neural architecture search (NAS) is to automatically design task-specific neural architectures, whose performance has already surpassed those of many manually designed neural networks. Existing NAS techniques focus on searching for the neural architecture and training the optimal network weights from the scratch. Nevertheless, it could be essential to study how to tune a given neural architecture instead of producing a completely new neural architecture in some scenarios, which may lead to a more optimal solution by combining human experience and the advantages of the machine's automatic searching. This paper proposes to learn to tune the architectures at hand to achieve better performance. The proposed Neural Architecture Tuning (NAT) algorithm trains a deep Q-network to tune neural architectures given a random architecture so that we can achieve better performance on a reduced space. We then apply adversarial autoencoder to make the learned policy be generalized to a different searching space in real-world applications. The proposed algorithm is evaluated on the NAS-Bench-101 dataset. The results indicate that our NAT framework can achieve state-of-the-art performance on the NAS-Bench-101 benchmark, and the learned policy can be adapted to a different search space while maintaining the performance. [ABSTRACT FROM AUTHOR]

The satellite observations unveiled that the July sea ice extent of the Arctic shrank to the lowest value, since 1979, in 2020 with a major ice retreat in the Eurasian shelf seas including Kara, Laptev, and East Siberian seas. Based on the ERA-5 reanalysis products, we explored the impacts of warm and moist air-mass transport on this extreme event. The results revealed that anomalously high energy and moisture converged into these regions in the spring months (April to June) of 2020, leading to a burst of high moisture content and warming within the atmospheric column. The convergence is accompanied by local enhanced downward longwave surface radiation and turbulent fluxes, which is favorable for initiating an early melt onset in the region with severe ice loss. Once the melt begins, solar radiation plays a decisive role in leading to further sea ice depletion due to ice–albedo positive feedback. The typical trajectories of the synoptic cyclones that occurred on the Eurasian side in spring 2020 agree well with the path of atmospheric flow. Assessments suggest that variations in characteristics of the spring cyclones are conducive to the severe melt of sea ice. We argue that large-scale atmospheric circulation and synoptic cyclones acted in concert to trigger the exceptional poleward transport of total energy and moisture from April to June to cause this record minimum of sea ice extent in the following July. [ABSTRACT FROM AUTHOR]

The combustion mechanism and gaseous products of asphalt binder at five different oxygen concentrations (21%, 18%, 15%, 12%, and 10%) were studied by thermogravimetry-Fourier transform infrared spectroscopy (TG-FTIR). The evolution of the functional groups and microscopic morphology of condensed phase were also analyzed by infrared spectroscopy (IR) and scanning electron microscopy (SEM). The semi quantitative research was realized by calculating the absorption peak area of IR, proximate and ultimate analyses. Results show that the oxygen concentration influences both the pyrolysis and combustion stages of asphalt, and the influence on the combustion of heavy components is more significant. With the decrease of oxygen concentration, the residual mass after the combustion of asphalt binder increases. Additionally, the temperature zone of combustion shifts higher, and a thermal reaction lag effect becomes more obvious. The concentration of oxygen only changes the concentration of gaseous products, instead of the types. Moreover, the concentrations of CO 2 , CO, H 2 O, SO 2 , etc. all decrease, and there is the biggest drop in CO 2. The low oxygen concentration inhibits the dehydrogenation reaction of asphalt in the aerobic pyrolysis stage, while the complete combustion of asphalt residues is inhibited in the combustion of heavy components stage. These will all provide more scientific basis for the analysis of asphalt combustion under low oxygen conditions in tunnel fires. • Combustion mechanism of asphalt binder under different oxygen concentration was discussed. • Dynamic evolution of volatiles released from asphalt binder combustion at different oxygen concentration was described. • Evolution of functional groups in the condensed phase of asphalt binder was analyzed. • Combustion mechanism of asphalt binder under low oxygen conditions was further understood. [ABSTRACT FROM AUTHOR]

This study experimentally and numerically explores the axial-compression behaviours of tapered recycled aggregate concrete-filled high-strength double skin steel tubular (RAC-FHDST) stub column. Twelve specimens were fabricated and tested, considering the effects of tapered angle, hollow ratio and replacement level of coarse recycled aggregate (CRA). The experimental results, consisting of deformation patterns, axial load versus strain responses and confining effect from external high-strength steel tube were obtained and analyzed. Failure mode showed that all stub columns exhibited good ductile behaviour. The elastic stiffness and ultimate strength of RAC-FHDSTs decreased with rising tapered angles, while the ductile index increased. As the replacement levels of CRA varied from 0% to 100%, the elastic stiffness and ductility index obviously reduced. Larger confining effect from outer steel tube to RAC occurred close to the top section of specimens, and the occurrence of confinement was advanced with decreasing hollow ratio and increasing CRA content. Additionally, detailed numerical models were constructed and validated using experiment results. The validated finite element (FE) models were then employed to analyze the working mechanism of specimen, encompassing the load distributions and the interaction between the sandwiched RAC and steel tubes. Afterwards, a parametric study was performed to reveal the influences of essential parameters on the axial compressive performance. Finally, the existing design approaches to normal CFST and CFDST stub columns were employed to assess their applicability for estimating the ultimate strengths of tapered RAC-FHDSTs. • Axial-load tests conducted on 12 RAC-FHDST stub columns. • Effects of tapered angle, hollow ratio and CRA content on the axial response of RAC-FHDSTs. • Confinement effect from outer high-strength steel tube. • The applicability of existing design provisions to tapered RAC-FHDSTs. [ABSTRACT FROM AUTHOR]

Perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), as emerging endocrine-disrupting chemicals (EDCs), pose adverse effects on aquatic organisms. Conventional ecological risk assessment (ERA) not fully considering the mode of toxicity action of PFOS and PFOA, may result in an underestimation of risks and confuse decision-makers. In the study, we developed species sensitivity weighted distribution (SSWD) models based on adverse outcome pathway (AOP) networks for deriving predicted no-effect concentrations (PNECs). Three kinds of weighting criteria (intraspecies variation, trophic level abundance, and data quality) and weighted log-normal distribution methods were adopted. The developed models considered the inter/intraspecies variation and integrated nontraditional endpoints of endocrine-disrupting effects. The PNECs of endocrine disruption effects were derived as 2.52 μg/L (95% confidence intervals 0.667–9.85 μg/L) for PFOS and 18.7 μg/L (5.40–71.0 μg/L) for PFOA, which were more conservative than those derived from the SSD method and were comparable with the values in the literature based on the chronic toxicity data. For PFOS, the effect of growth and development was the most sensitive; however, for PFOA, the effect of reproduction was the most sensitive in the effects of growth and development, reproduction, biochemistry and genetics, and survival. The endocrine-disrupting effects of PFOS and PFOA are significant and need to be fully recognized in the ERA. This study provided an ERA framework that can improve the ecological relevance and reduce the uncertainty of PNECs of EDCs. [Display omitted] • SSWD considers the inter/intraspecies variation and data quality of toxicity. • AOP network integrates endocrine disruption effects of muti-biological levels. • PNECs of endocrine disruption effects as 2.52 (PFOS) and 18.7 (PFOA) μg/L. • SSWD-based PNECs are more conservative than those from SSD models. • AOP-SSWD improves ecological relevance and reduce uncertainty of PNEC. [ABSTRACT FROM AUTHOR]

• Impact-resistant behaviours of steel–concrete composite wall with recycled aggregate concrete. • Time histories of impact force and deformation, and failure mode. • Effects of CRA content, material strength, steel plate ratio, tie-bar spacing, impact energy and axial load ratio on the impact response. • Single degree of freedom approach used to predict the displacement response. This paper investigates the impact-resistant behaviours of steel–concrete (SC) composite walls experimentally and numerically, which consist of two outer steel plates and infilled recycled aggregate concrete (RAC). Totally eight SC walls were designed and fabricated with different coarse recycled aggregate (CRA) content and steel plate thicknesses. Drop-hammer impact testing was first performed to obtain the failure mode, impact force and deformation. Test results indicated that the impact resistance behaviour of SC walls enhanced considerably with a decrease in CRA content. The tie bars combined with studs were effective to avoid the separation of steel plate from the concrete core. Afterwards, the finite element (FE) models were developed and calibrated, and then used to obtain more information on the full-range motion response, development of stress and strain, and energy absorption. In addition, the influences of different parameters, including the CRA content, material strength, steel plate ratio, tie-bar spacing, impact energy and axial load ratio on the impact resistance performance were assessed. Finally, the displacement response of SC composite walls with RAC was predicted using single-degree of freedom (SDOF) approach. [ABSTRACT FROM AUTHOR]

Background: Left atrial (LA) and left atrial appendage (LAA) dysfunction has been demonstrated to contribute to atrial fibrillation (AF)-related stroke. However, usefulness of LA and LAA mechanics has not been fully compared. We sought to investigate the association of LA and LAA mechanics with stroke and to compare their diagnostic values in the risk stratification of stroke in patients with nonvalvular AF.Methods: A total of 208 consecutive patients with AF (63.58 ± 10.37 years, 63.9% male,57.7% persistent AF) who underwent echocardiography before catheter ablation were prospectively enrolled. Speckle-tracking was used to measure LA and LAA global longitudinal strain (GLS). LA and LAA mechanical dispersions (MD) were defined as the standard deviation (SD) of time to peak positive strain corrected by the R-R interval.Results: Patients with prior stroke/ transient ischemic attack (TIA) (n = 31) had significantly higher LA and LAA MD than those without (n = 177) (11.56 ± 4.38% vs. 8.43 ± 3.44%, 15.15 ± 5.46% vs. 10.94 ± 4.40%, both P < 0.01). In multivariable analysis, LA and LAA MD were independently associated with stroke/TIA (odds ratio, 1.18-1.29, 1.19-1.22, respectively, both P < 0.01), providing incremental values over clinical and standard echocardiographic parameters. In a subgroup analysis, LA MD was more useful than LAA MD in patients with normal LA volumes, while LAA MD was superior to LA MD in patients with LA enlargement.Conclusions: Higher LA and LAA mechanical dispersion are independently associated with stroke/TIA in AF patients and had incremental values over clinical and conventional echocardiographic parameters. What's more, priorities of dispersion assessment are different depending on patients' LA size. [ABSTRACT FROM AUTHOR]

Key message: A novel genomic region controlling thermotolerance at flowering was identified by the combination of whole genomic re-sequencing and bulked segregant analysis in maize. The increasing frequency of extreme high temperature has brought a great threat to the development of maize throughout its life cycle, especially during the flowering phase. However, the genetic basis of thermotolerance at flowering in maize remains poorly understood. Here, we characterized a thermotolerant maize ecotype Abe2 and dissected its genetic basis using a F2:8 recombinant inbred line (RIL) population generated from a cross between Abe2 and B73. After continuous high temperature stress above 35 °C for 17 days, Abe2 and B73 show distinct leaf scorching phenotype under field conditions. To identify the genomic regions associated with the phenotypic variation, we applied a combination of whole genomic re-sequencing and bulked segregant analysis, and revealed 10,316,744 SNPs and 1,488,302 InDels between the two parental lines, and 2,693,054 SNPs and 313,757 InDels between the two DNA pools generated from the thermos-tolerant and the sensitive individuals of the RIL, of which, 108,655 and 17,853 SNPs may cause nonsynonymous variations. Finally, a 7.41 Mb genomic region on chromosome 1 was identified, and 7 candidate genes were annotated to participate in high temperature-related stress response. A candidate gene Zm00001d033339 encoding a serine/threonine protein kinase was proposed to be the most likely causative gene contributing to the thermotolerance at flowering by involving in stomatal movement (GO: 0010119) via Abscisic acid (ABA) pathway (KO04075). This work could provide an opportunity for gene cloning and pyramiding breeding to improve thermotolerance at flowering in maize. [ABSTRACT FROM AUTHOR]

• Novel AA-LLME based on solidification of floating DES method was developed. • DESs with low viscosity, density and melting point near room temperature were used. • Central composite design was used for the method optimization. • This method is simple, low cost, centrifugal-free, and environment friendly. For this work, a novel air-assisted liquid-liquid microextraction based on solidification of floating deep eutectic solvent (AA-LLME-SFDES), coupled with a high performance liquid chromatography (HPLC) method was developed for the detection of benzophenone and salicylate ultraviolet filters in water samples. Three types of fatty acid-based hydrophobic deep eutectic solvents (DESs) with low viscosity, low-density, and melting point close to room temperature were prepared and employed as extraction solvents. This air-assisted liquid-liquid microextraction was carried out in a glass centrifuge tube. Subsequently, the glass tube was introduced into ice-water bath and held for 3 min, during which the upper DES phase was solidified. The water phase was easily extracted using a syringe equipped with a long needle, and later, the glass tube was removed from ice-water bath. The solidified DES phase was immediately melted at room temperature and used for HPLC analysis. The response surface methodology was employed to optimize some influencing parameters such as the volume of the extraction solvent, the pH value of sample solution, the number of extraction cycles, and the addition of salt. A quadratic model, namely a central composite design, was used to replace the conventional single factor analysis. It was found that under optimal conditions, the limits of determination and quantification were 0.045–0.54 µg L−1 and 0.15–2.0 µg L−1, respectively. The relative standard deviations for inter-day (n = 5) and intra-day (n = 5) precision were ≤ 4.2%, whereas the enrichment factors for the ultraviolet filters were obtained from 41 to 50. Furthermore, this novel method was successfully employed for the detection of benzophenone and salicylate ultraviolet filters from real water samples. The recoveries ranged from 87.5% to 105.8%, whereas the RSDs were lower than 3.6%. [ABSTRACT FROM AUTHOR]

As a new class of green solvents, hydrophobic deep eutectic solvents (DESs) have attracted considerable attention for liquid phase microextraction. In this study, a hydrophobic DES composed of trioctylmethylammonium chloride and oleic acid was successfully applied for the vortex-assisted liquid-liquid microextraction (VA-LLME) of Sudan I in food samples coupled with high performance liquid chromatography with diode array detection (HPLC-DAD). Trioctylmethylammonium chloride and oleic acid at a molar ratio of 1:2 showed higher extraction recovery for Sudan I than other DESs. The deep eutectic solvent was prepared and characterized by Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance spectroscopy (1H NMR). The parameters affecting extraction recovery were optimized in detail. This hydrophobic DES based VA-LLME technique exhibited a high extraction recovery close to 100% at room temperature within 3 min. Under the optimized conditions, wide linear ranges were acquired with r2 equal to 0.9992. The limit of detection was 0.3 µg kg−1. The inter day and intra-day precision values were less than 5.4%. This hydrophobic DES based VA-LLME technique was successfully applied for the determination of Sudan I from duck blood and chili power samples with the satisfactory recoveries from 83.4 to 114.1% and relative standard deviations from 1.5 to 7.6%. In addition, the analytical parameters of this method and other liquid phase microextraction methods were compared. [ABSTRACT FROM AUTHOR]

Left atrial appendage (LAA) dysfunction is associated with increased risk of thromboembolic events. However, little is known about LAA mechanical dispersion (MD) would provide additional information toward thromboembolism over the CHA2DS2-VASc score. The aim of this study was to determine the association of LAA mechanics as assessed by speckle-tracking imaging with thromboembolic events in patients with nonvalvular atrial fbrillation (AF). A total of 116 consecutive patients with AF referred for transesophageal echocardiography (TEE) were prospectively enrolled. Of these, 17(14.7%) patients had prior embolic events. Using speckle-tracking echocardiography (STE), we measured the LAA strain in each of 24 segments in mid-esophageal TEE views obtained at 0°, 45°, 90° and 135°. LAA MD was defined as the standard deviation (SD) of time to peak positive strain corrected by the R-R interval. Patients with embolism had lower LAA global longitudinal strain (GLS) (8.56 ± 2.62% vs 11.37 ± 5.54%, p = 0.002) and higher LAA MD (16.90 ± 6.67% vs 12.10 ± 3.94%; P = 0.010) than those without embolism. LAA MD >13.1% differentiated patients with embolism from controls, with an area under the curve (AUC) of 0.709(p = 0.004). LAA MD was independently associated with the presence of thromboembolism in multivariate analysis (odds ratio, 1.24; 95% confidence interval, 1.08–1.42; P = 0.002). The model based on CHA 2 DS 2 -VASc score for discrimination of patients with embolism was significantly improved by adding LAA MD (P < 0.01). LAA MD obtained from strain echocardiography was significantly associated with a prior history of embolic events and had incremental diagnostic value over CHA2DS2VASc score, suggesting that LAA MD may be useful in refining thromboembolic risk stratification in patients with AF. • Patients with embolism had higher LAA mechanical dispersion (MD) than those without embolism. • LAA MD was independently associated with the presence of thromboembolism in multivariate analysis. • LAA MD significantly improved the model based on CHA2DS2-VASc score for discrimination of patients with embolism. [ABSTRACT FROM AUTHOR]

Deeply buried Oligocene Zhuhai sandstones are important gas exploration targets in the western Pearl River Mouth Basin, South China Sea. The tight sandstones are characterized by low porosity (less than 10%), low permeability (less than 1 mD) and strong microscopic heterogeneity due to diagenesis during their geologic history. Petrographic analysis is undertaken based on cores, thin sections, X-ray diffraction and scanning electron microscope, that is helpful to understand the facies, lithologic characteristics, diagenesis and their impact on reservoir quality. Six lithofacies were defined in the Zhuhai sandstones, namely bedded granule-rich coarse sandstone to granule conglomerate, cross-bedded medium-to coarse-grained sandstone, cross-bedded fine-to coarse-grained sandstone, structureless sandstone, interbedded sandstone and siltstone and claystone and shale. They were accumulated in the fan delta systems and tidal flat systems. The sandstones are dominated by feldspathic litharenite, litharenite, sublitharenite and quartz arenite. Major portion of the porosity is due to secondary pores and primary pores are relatively less dominant. Primary pores are more important to tight sandstones, well preserved with moderate compaction and weak cementation. Well-sorted, medium-to coarse-grained sandstones with rigid quartz and rock fragment grains commonly have high primary porosity. Early cements such as chlorite rims are helpful for primary porosity preservation. The dissolution of feldspars in the Zhuhai Formation helps to increase the total porosity, whereas it also decreases the permeability and spoils the tight reservoir quality. • Diagenesis and reservoir quality in tight gas sandstones of a tidally influenced fan delta is investigated. • sTwo depositional systems are recognised in the Zhuhai Formation. • Lithology characteristics, pore systems, reservoir properties and diagenetic minerals are identified. • Diagenetic mineral and diagenetic phase control the primary porosity and secondary porosity preservation. [ABSTRACT FROM AUTHOR]

Five specimens have been tested under cyclic lateral loads to explore the seismic behavior of T-shaped multi-partition steel–concrete shear walls along the asymmetrical axis. The loading has been applied by considering the torsion effect from non-coincidence between the lateral loads and the shear center in this study. The main parameters of the test are the axial compression ratio and section height-to-breadth ratio aiming to study the vertical load and web constraint effect. The test results indicate that the failure mode of all specimens along the asymmetric axis is bending failure with minor shear deformation measured during loading. The yield drift (1/138) and the ultimate drift (1/41) of the T-shaped multi-partition steel–concrete shear walls could meet the requirement of the corresponding code, namely 1/350 and 1/70, respectively. The increase in axial compression ratio increases the out-of-plane displacement but decreases the ductility of the specimens, whilst the increase in section height-to-breadth ratio decreases the out-of-plane displacement of the specimens. The relatively small torsion angle of less than 0.6° indicates that the T-shaped multi-partition steel–concrete shear walls have good torsion resistance. Under the cyclic lateral loads along the asymmetrical axis, the out-of-plane displacement of the T-shaped specimen will occur on the side without the web. The web elastic stress distribution model can predict the lateral resistance more accurately, whilst the full-section plastic stress distribution model overestimates the lateral resistance of T-shaped multi-partition steel–concrete shear walls. • T-shaped multi-partition steel–concrete shear walls were tested under asymmetrical loads. • The ductility of T-shaped composite shear walls meets the requirement in Chinese code. • The measured torsion angle confirms the good torsional capacity of T-shaped composite shear walls. • The flange of T-shaped walls is under additional loads due to the out-of-plane deformation. • The web elastic stress distribution model is more suitable to predict the lateral resistance of the specimens. [ABSTRACT FROM AUTHOR]

The Pacific sector of the Arctic Ocean (PA, hereafter) is a region sensitive to climate change. Given the alarming changes in sea ice cover during recent years, knowledge of sea ice loss with respect to ice advection and melting processes has become critical. With satellite-derived products from the National Snow and Ice Center (NSIDC), a 38-year record (1979–2016) of the loss in sea ice area in summer within the Pacific-Arctic (PA) sector due to the two processes is obtained. The average sea ice outflow from the PA to the Atlantic-Arctic (AA) Ocean during the summer season (June–September) reaches 0.173×106 km 2 , which corresponds to approximately 34 % of the mean annual export (October to September). Over the investigated period, a positive trend of 0.004×106 km 2 yr -1 is also observed for the outflow field in summer. The mean estimate of sea ice retreat within the PA associated with summer melting is 1.66×106 km 2 , with a positive trend of 0.053×106 km 2 yr -1. As a result, the increasing trends of ice retreat caused by outflow and melting together contribute to a stronger decrease in sea ice coverage within the PA (0.057×106 km 2 yr -1) in summer. In percentage terms, the melting process accounts for 90.4 % of the sea ice retreat in the PA in summer, whereas the remaining 9.6 % is explained by the outflow process, on average. Moreover, our analysis suggests that the connections are relatively strong (R=0.63), moderate (R=-0.46), and weak (R=-0.24) between retreat of sea ice and the winds associated with the dipole anomaly (DA), North Atlantic Oscillation (NAO), and Arctic Oscillation (AO), respectively. The DA participates by impacting both the advection (R=0.74) and melting (R=0.55) processes, whereas the NAO affects the melting process (R=-0.46). [ABSTRACT FROM AUTHOR]

In recent years, hydrophobic deep eutectic solvents as new generation of green solvents have attracted wide attention in liquid microextraction technique. In this article, four hydrophobic deep eutectic solvents composed of trioctylmethylammonium chloride and oleic acid were designed and prepared firstly. Combined with high‐performance liquid chromatography, these deep eutectic solvents were used as an extraction solvent in vortex‐assisted dispersive liquid–liquid microextraction for the selective enrichment and indirect determination of trace nitrite from real water and biological samples. This method is based on the diazotization‐coupling reaction of nitrite with p‐nitroaniline and diphenylamine in acidic water, and then the nitrite is quantified indirectly by measuring the obtained azo compounds. Some factors influencing the extraction efficiency, including the reaction and extraction conditions, were investigated. Under the optimized conditions, the method has a linear range of 1–300 μg/L with a correlation coefficient of 0.9924, limit of detection of 0.2 μg/L, limit of quantitation of 1 μg/L, intraday and interday relative standard deviations of 4.0 and 6.0%. This method was successfully applied in determination of nitrite from three environmental water and two biological samples with the recovery in the range of 90.5–115.2%. In addition, these results were well agreement with those obtained by the conventional Griess method. [ABSTRACT FROM AUTHOR]

Abstract Polymer solar cells (PSCs) suffer energy loss due to a number of reasons including high thermalisation, large exciton binding energy and electron-hole recombination within the active layer of the device. Although much effort has gone into addressing the above, interface recombination between a FTO cathode and ZnO electron transport layer (ETL) has remained relatively unnoticed. In this paper, an efficient inverted PSC is demonstrated by introducing a solution-processed SnO 2 film between the ZnO ETL and FTO cathode. The use of the SnO 2 layer, improves significantly all the device performance parameters of PSCs based on P3HT:PC 61 BM and PCDTBT:PC 71 BM system, achieving higher power conversion efficiency (PCE) up to 4.25% and 7.16%, compared to that without the SnO 2 film (PCE 3.10% and 5.52%). The improved performance is attributed to the enhanced optical transmission, the reduced energy barrier and suppression of carrier recombination at the interface between the ZnO layer and cathode. Furthermore, the SnO 2 film is shown to facilitate electron injection as well as effective hole blocking from the active layer. This study provides an efficient approach to optimize the device performance of PSCs by interfacial modification at bottom conductive electrode. Graphical abstract Image Highlights • Solution-processed SnO 2 nanoparticles were introduced to improve the electron transport in ZnO-based PSCs. • The PCE of PCDTBT: PC 71 BM-based PSCs was increased to 7.16% by incorporating the SnO 2 /ZnO bilayer interlayer. • Enhanced performance could be attributed to the reduced energy barrier and suppressed carrier recombination. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) chiral self-assembly system of 5-(benzyloxy)-isophthalic acid derivative/(S)-(+)-2-octanol/highly oriented pyrolytic graphite was studied. A combined density functional theory/molecular mechanics/molecular dynamics (DFT/MM/MD) approach for system of 2D chiral molecular self-assembly driven by hydrogen bond at the liquid/solid interface was thus proposed. Structural models of the chiral assembly were built on the basis of scanning tunneling microscopy (STM) images and simplified for DFT geometry optimization. Merck Molecular Force Field (MMFF) was singled out as the suitable force field by comparing the optimized configurations of MM and DFT. MM and MD simulations for hexagonal unit model which better represented the 2D assemble network were then preformed with MMFF. The adhesion energy, evolution of self-assembly process and characteristic parameters of hydrogen bond were obtained and analyzed. According to the above simulation, the stabilities of the clockwise and counterclockwise enantiomorphous networks were evaluated. The calculational results were supported by STM observations and the feasibility of the simulation method was confirmed by two other systems in the presence of chiral co-absorbers (R)-(-)−2-octanol and achiral co-absorbers 1-octanol. This theoretical simulation method assesses the stability trend of 2D enantiomorphous assemblies with atomic scale and can be applied to the similar hydrogen bond driven 2D chirality of molecular self-assembly system. [ABSTRACT FROM AUTHOR]

• Coupling the traditional mechanical rolling and high frequency ultrasonic vibration process. • Numerical analysis and research on the residual stress and surface roughness of the processed components. • Explore the influence of different process parameters on component residual stress and surface roughness. In order to improve the surface performance of the key components of Ti-6Al-4 V titanium alloy and meet its requirements for surface performance and life in complex service environments, this study combines traditional mechanical rolling with high-frequency ultrasonic vibration, and achieves high-speed impact on the surface of titanium alloy and traditional rolling at the same time. Numerical simulation of ultrasonic rolling processing of titanium alloy workpiece is carried out, the residual stress and surface roughness of the workpiece after processing are analyzed, and the influence of different process parameters on it is explored. The results show that ultrasonic rolling processing can effectively improve the surface properties of Ti-6Al-4 V titanium alloy, so that the residual stress distribution of the workpiece is more uniform and increases with the increase of static force and amplitude. When the static force is 1000 N and the amplitude is 8 μm, the surface finishing effect is the best. [ABSTRACT FROM AUTHOR]

Materials and structures with enhanced energy-absorbing and impact perception capabilities are widely deployed for crash mitigation, protective packaging of sensitive elements, and personal impact protection. However, conventional lightweight structures with a monolithic constitutive material cannot simultaneously achieve exceptional energy-absorbing capacity and electromechanical sensitivity. Here we proposed a new class of architected ceramic-polymer composites with improved energy-absorbing capacity and piezoelectric performance. An interconnected porous lead zirconate titanate ([Pb(Zr 0.52 Ti 0.48)O 3 ], PZT) skeleton with uniformly distributed cellular-like pores in the transverse section and directionally aligned porous structure in the longitudinal section was fabricated using a facial camphene-templated freeze-casting method. Subsequently, the polymeric polydimethylsiloxane (PDMS) was impregnated into the skeleton to form the three-dimensional (3-D) interpenetrating-phase piezoelectric composite (IP3C). The as-fabricated interpenetrating architecture with each phase interconnected has endowed the proposed IP3C with an unprecedented combination of mechanical-damping (energy-absorption efficiency ∼ 7.71 MJ m−3) and electromechanical-conversion (piezoelectric constant d 33 ∼ 146 pC N−1) properties, which are 9 times and 7 times higher than the conventional counterpart 0–3 piezoelectric composite, respectively. As evidenced by numerical simulations, this remarkable enhancement is attributed to the high stress transfer efficiency within the IP3C, which is intrinsically controlled by the rationally designed interpenetrating architecture. The findings reported here demonstrate that multifunction, e.g., exceptional energy absorption and high sensitivity, can be achieved in one composite with architecture design, thereby driving forward and expanding the fundamental understanding in the area of multifunctional materials in hostile loading environments. • An interconnected porous lead zirconate titanate ([Pb(Zr 0.52 Ti 0.48)O 3 ], PZT) skeleton with uniformly distributed cellular-like pores in the transverse section and directionally aligned porous structure in the longitudinal section was fabricated using a facial camphene-templated freeze-casting method. • The as-fabricated interpenetrating architecture with each phase is interconnected has endowed the proposed IP3C with an unprecedented combination of mechanical-damping and electromechanical-conversion properties, which are 9 times and 7 times higher than the conventional counterpart 0–3 piezoelectric composite, respectively. • The findings reported here demonstrate that multifunction, e.g., exceptional energy absorption and high sensitivity, can be achieved in one composite with architecture design, thereby driving forward and expanding the fundamental understanding in the area of multifunctional materials in hostile loading environments. [ABSTRACT FROM AUTHOR]

• Corn straw biogas residues is an ideal material for full-scale composting. • The biogas residues get maturity after 80 days of composting. • Temperature and NI was easily and credibly parameters to evaluate maturity. • Anaerolineaceae and Limnochordaceae were the most abundant bacteria. • Chaetomium was the most important fungal to decompose lignocellulose. Recycling of biogas residues from corn stover anaerobic digestion is crucial for the development of biogas industry. Full-scale composting process is the feasible way to convert biogas residues to fertilizer. The aim of the study was to explore the feasibility of full-scale composting process to dispose biogas residue to fertilizer, and to evaluate the quality of the compost. The results showed the biogas residues could rapidly reach the thermophilic stage and last at least 20 days, NH 4 +-N, TOC and C/N decreased along with the composting process, while TP, TK and NO 3 –-N showed an opposite trend. Germination index(GI) and seedling growth index showed that raw biogas residues was toxic for plant, but the GI and seedling growth index were increased during the composting process, except for the cooling stage sample. Anaerolineaceae and Limnochordaceae were the main bacteria involved in the composting process, and Chaetomium was the most important fungus. [ABSTRACT FROM AUTHOR]

Auxin regulates diverse aspects of growth and development. Furthermore, polar auxin transport, which is mediated by the PIN-FORMED (PIN) and AUXIN1/LIKE-AUX (AUX/LAX) proteins, plays a crucial role in auxin distribution. In this study, six PIN and four AUX/LAX genes were identified in ramie (Boehmeria nivea L.). We used qRT-PCR to characterize and analyze the two gene families, including phylogenetic relationships, intron/exon structures, cis-elements, subcellular localization, and the expression patterns in different tissues. The expression of these genes in response to indole-3-acetic acid (IAA) treatment and drought stress was also assessed; the results indicate that most of the BnAUX/LAX and BnPIN genes were regulated as a result of IAA treatment and drought stress. Our study provides insights into ramie auxin transporters and lays the foundation for further analysis of their biological functions in ramie fiber development and adaptation to environmental stresses. [ABSTRACT FROM AUTHOR]