Search

The three‐point bending test was conducted and the digital image correlation (DIC) technique was used to observe the full‐field displacement and strain of the notched beam. The initial cracking load and the crack mouth opening displacement were determined based on the deformation field near the tip and mouth of the notch. The initial cracking toughness Kini and the unstable fracture toughness Kun calculated according to the double‐K fracture model, the fracture energy GF and the ductility index Du determined with a modified method, and the equivalent fracture toughness K at four different deformation stages, were analyzed under different temperatures and basalt fiber contents. The results showed that Kini exhibited a monotonic decrease trend with the increasing temperature, indicating that the notched beam was prone to initial cracking after high temperatures. However, Kini rose slowly with the increase of the fiber content, suggesting that the basalt fiber had little influence on Kini. At the temperatures below 400°C, the Kun, GF, Du, and K at each deformation stage increased with the rise of temperature. At the temperatures above 400°C, the Kun, GF, Du, and K at each deformation stage apparently decreased with the increase of temperature. Under the current test conditions, the basalt fiber content of 0.4% by volume had the greatest improvement on the fracture performances of concrete after high temperatures. [ABSTRACT FROM AUTHOR]

Digital Image Correlation (DIC) technique is used to collect the whole‐field strain of concrete subjected to bending loads under different temperature change cycles, cooling rates, and water‐binder ratio. The bending damage behavior of concrete under large‐difference temperature circulation is analyzed with the whole‐field strain cloud map and data. In addition, with the whole‐field strain obtained by 3D‐DIC technology, the strain‐based damage variable is defined. Furthermore, the damage degree of concrete specimen in the bending process is quantified, and the bending damage evolution process of concrete under the action of temperature circulation is discussed. The results show that the damage of concrete in areas with large temperature differences is related to the number of temperature change cycles as well as the cooling rate. Moreover, the increase in the number of temperature change cycles and the cooling rate will aggravate the bending damage of the concrete. Additionally, the higher the water‐binder ratio, the more serious the adverse effect of temperature circulation on the concrete. This paper provide certain reference for the evaluation of concrete bending deformation damage in areas with a large temperature difference. [ABSTRACT FROM AUTHOR]

To study the effect of pore structure changes on the fatigue life of concrete in areas with large temperature differences, a concrete fatigue test program was designed after a temperature cycle of −50 to 70°C. Results show that temperature differences considerably influence pores with a size ranging from 0.1 to 27.98 nm. Furthermore, the fatigue life of concrete gradually decreases with the increase in the pore structure parameters of 0.1 to 27.98 nm. This result indicates that the effect of temperature difference on the fatigue life of concrete in areas with large temperature differences must not be ignored. The combined effect of temperature differences and load increases the coarsening rate of the pore structure, and the load remarkably affects pores with a size ranging from 524.26 to 10,000 nm. To characterize the pore structure of concrete under temperature cycling and fatigue load, two pore structure characteristic parameters, namely, comprehensive change rate of pore size (Sz) and pore structure complexity coefficient (Cz), are proposed. These parameters, together with the total porosity (Ptotal), form a three‐dimensional pore structure characteristic parameter and establish the relationship expression between the three‐dimensional pore structure parameters and the fatigue life of concrete (N); thus, they provide basis for the prediction of the fatigue life of concrete on the basis of pore structure. [ABSTRACT FROM AUTHOR]

Dragonflies fly in flapping wing flight, bearing a variety of variable forces during flight. To comprehend and study from the biological system and then carry out technological innovation, the characteristic point cloud data of dragonfly wings were obtained and the 3D geometric models were reconstructed. The biomechanical characteristics of Costa, Radius and Postal veins of the wings were examined by a nanoindenter. It was shown that the reduced modulus and nanohardness of Radius of dragonfly forewings and hindwings are large. The maximum reduced modulus and nanohardness of Costa, Radius and Postal veins of hindwings appear at the place 0.7L of dragonfly wings. The biomechanical characteristics of dragonfly wings were researched and then the deformations and stresses of the bionic models under the uniform load were investigated. It was shown that the dragonfly wings are less deformed under the uniform load and the chief veins have stronger stability and bearing capacity. The combinations of the main veins and branch veins can improve the overall strength and load-bearing capacity of dragonfly wings. It tries to explore the structural models of imitating dragonfly wings with good load-bearing capacity and, then, were used to guide the plan and manufacturing of thin film and offer novel ideas and methods for the study of thin film. [ABSTRACT FROM AUTHOR]

The roof collapse of deep cavities has been investigated only under fully dry or saturated conditions. However, natural soils are largely unsaturated, and consequently, their mechanical behavior is significantly different owing to the presence of matric suction. In this study, a novel analytical solution for the roof collapse of deep cavities in unsaturated soils is developed based on the upper bound theorem and the nonlinear Mohr–Coulomb criterion, and the width of a cavity with an arbitrary shape at collapse is derived. Subsequently, a parametric study is conducted to investigate the effects of water retention properties, effective cohesion, friction angle, supporting pressure, and nonlinear coefficient on the safety factors of rectangular deep cavities. It is found that matric suction and soil type have significant influences on the stability of deep cavities. There is a peak for the safety factors of deep cavities as the matric suction increases when the water‐holding capacity of the soil is low. This novel analytical solution provides a new insight into the stability of deep cavities in unsaturated soils. [ABSTRACT FROM AUTHOR]

Based on data obtained from ERA-20C during 1900–2010, this study statistically conducts spatiotemporal characteristics and relations between boundary layer height (BLH) and aridity index (AI) in East Asian drylands, thus originally understanding dry–wet changes from perspective of atmospheric boundary layer. A high (low) BLH generally coincides with regions that have small (large) AI. The annual variability of BLH and AI is negatively correlated with correlation coefficients of − 0.469, − 0.880, and − 0.947 for hyper-arid, arid, and semiarid regions, respectively. This correlation is followed in 61.3, 55.9, and 55.9% of years, whereas in 12.6, 8.1, and 9.9% of years the changes in BLH are in advance of the changes in AI for hyper-arid, arid, and semiarid regions, respectively. The BLH and area of East Asian drylands have a positive correlation coefficient of 0.651. These results indicate that there is a connection between changes in BLH and dry–wet changes in the climate of arid regions, confirming the changes in BLH drive dry–wet changes. [ABSTRACT FROM AUTHOR]

• Vitamin d is known to play a pivotal role in depression. However the two independent metabolites, 25(OH)D 3 and 25(OH)D 2 have totally different associations with depression. • Serum 25(OH)D 3 level has an inverse linear association with depressive symptoms in US females. • The association between 25(OH)D 2 and depression follows an inverted U-shaped curve. The role of vitamin D in depression has been gaining increased research interest. However, little is known about the independent associations of serum 25-hydroxyvitamin D 3 (25(OH)D 3) and D 2 (25(OH)D 2) with depressive symptoms. The goal of this study was to examine the metabolites of vitamin D and their associations with depression. This study was conducted in US females using data from the National Health and Nutrition Examination Survey 2011–2014. Depressive symptoms were assessed using a nine-item Patient Health Questionnaire, and serum 25(OH)D 3 and 25(OH)D 2 levels were measured using liquid chromatography-tandem mass spectrometry. Linear regression and generalized additive models were applied to evaluate the associations between 25(OH)D 3 , 25(OH)D 2 and depression. A negative association between serum 25(OH)D 3 and depressive symptoms was observed in the fully adjusted model. This association was also found among widowed, divorced, separated, and never-married individuals. The association between 25(OH)D 2 and depressive symptoms was not statistically significant, but the dose-response analysis revealed an inverted U-shaped relationship between them with an inflection point at 56.2 nmol/L. To the left of the inflection point, we detected a positive association between 25(OH)D 2 and depressive symptoms, whereas a negative association was observed to the right of the inflection point. The study used a cross-sectional approach, so causation cannot be determined. Our study shows an inverse linear association between serum 25(OH)D 3 and depressive symptoms in US females. The association between 25(OH)D 2 and depression follows an inverted U-shaped curve with the inflection point at 56.2 nmol/L. [ABSTRACT FROM AUTHOR]

Pulse oximetry saturation (SpO2) is a main parameter that reflects the condition of the human cardiovascular system. It is best to detect SpO2 non-destructively with photoplethysmography (PPG). The embedded technique was used to control the dual-wavelength LED illuminating the fingertips, photoelectric sensors to detect reflection data and, then, upload the data to computers, IIR filtering and S-G smoothing filtering on MatLab to process the collected data. The results is shown that the discreteness of the processed data was reduced by 2–6% and the high-frequency noise and motion artifact were removed effectively. It would provide some references for improving the accuracy of the pulse oxygen saturation monitoring system in a complex environment. [ABSTRACT FROM AUTHOR]

BACKGROUND: Highbush blueberry (Vaccinium corymbosum), the species primarily grown in the state of Washington, U.S., is relatively cold hardy. However, low temperatures in winter and early spring can still cause freeze damage to the buds. OBJECTIVE: This study explored hyperspectral imaging (HSI) for detecting freeze induced bud damage. Blueberry buds (c.v. Duke) were collected over two seasons and tested in the laboratory to detect damage at four typical phenological stages. METHODS: The HSI data was acquired via line scan HSI system with spectral wavelength ranging from 517 to 1729 nm for buds grouped into either normal or injured mortalities. The successive projection algorithm was employed for pertinent feature wavelength selection. Analysis of variance and linear regression were then applied for evaluating sensitivity of feature wavelengths. RESULTS: Overall, five salient wavelengths (706, 723, 872, 1384, and 1591 nm) were selected to detect bud freeze injury. A quadratic discriminant analysis method-based analysis verified reliability of these five wavelengths in bud damage detection with overall accuracy in the ranges of 64 to 82%for the test datasets of each stage in two seasons. CONCLUSIONS: This study indicated potential of optical sensing to identify the injured buds using five salient wavelengths. [ABSTRACT FROM AUTHOR]

Background: The role of vitamin D in depression has been gaining increased research interest. However, little is known about the independent associations of serum 25-hydroxyvitamin D3 (25(OH)D3) and D2 (25(OH)D2) with depressive symptoms. The goal of this study was to examine the metabolites of vitamin D and their associations with depression.Methods: This study was conducted in US females using data from the National Health and Nutrition Examination Survey 2011-2014. Depressive symptoms were assessed using a nine-item Patient Health Questionnaire, and serum 25(OH)D3 and 25(OH)D2 levels were measured using liquid chromatography-tandem mass spectrometry. Linear regression and generalized additive models were applied to evaluate the associations between 25(OH)D3, 25(OH)D2 and depression.Results: A negative association between serum 25(OH)D3 and depressive symptoms was observed in the fully adjusted model. This association was also found among widowed, divorced, separated, and never-married individuals. The association between 25(OH)D2 and depressive symptoms was not statistically significant, but the dose-response analysis revealed an inverted U-shaped relationship between them with an inflection point at 56.2 nmol/L. To the left of the inflection point, we detected a positive association between 25(OH)D2 and depressive symptoms, whereas a negative association was observed to the right of the inflection point.Limitations: The study used a cross-sectional approach, so causation cannot be determined.Conclusions: Our study shows an inverse linear association between serum 25(OH)D3 and depressive symptoms in US females. The association between 25(OH)D2 and depression follows an inverted U-shaped curve with the inflection point at 56.2 nmol/L. [ABSTRACT FROM AUTHOR]

• An automatic monitoring-control framework for excavation is proposed. • An automatic monitoring-control system is established with the IoT technology. • Successful application to an ultra-deep excavation extremely adjacent to the tunnels. • A well-documented field data is presented. This paper proposes an automatic monitoring and control system to control the construction disturbances of an ultra-deep foundation pit extremely adjacent to the operational metro tunnels. By real-time monitoring the structural response of tunnels and foundation pits, the reinjection wells and servo support system were automatically controlled to change the groundwater level and support axial force, respectively. All the relevant monitoring and control equipment was integrated into the system through Internet of Things technology. The field observations revealed that the proposed automatic monitoring-control system and framework can well control the excavation disturbance in adjacent metro tunnels. Under the ultra-deep excavation depth of 42.25 m and ultra-close spacing of 3.0 m, the maximum absolute value of the observed tunnel displacement was less than 5 mm. All the relevant structural responses of the tunnel and foundation pit were within limits. The wall deformation of the servo side is different from the common bulging deformation curve and is approximately 2 times smaller compared to the non-servo side. The observed tunnel deformation mainly changed at the excavation stage within the buried depth of tunnels. The presented system, data, advised control index and framework can provide useful guidance for similar scenarios. [ABSTRACT FROM AUTHOR]

The soil water characteristic curve (SWCC) is an important tool in soil science and geotechnical applications. Most previous studies on SWCCs are limited to one to three drying‐wetting cycles, mainly because SWCC measurement is complex and time‐consuming. The numerous models that have been proposed to predict hysteresis in SWCCs. In this paper, a novel simplified equation is proposed based on the van Genuchten model, whereby SWCC hysteresis can be easily predicted from the initial drying SWCC. The theory for describing the main wetting curve and main drying curve considers the ink‐bottle effect and entrapped air. Laboratory experiments on silicon micro‐powder (SMP) and Guangxi Guiping clay (GGC) were conducted to determine SWCCs for five drying‐wetting cycles. The proposed equation was verified using the experimental SMP data and data from the literature. The predicted hysteretic SWCCs are in good agreement with the experimental data. [ABSTRACT FROM AUTHOR]

The cutting efficiency and wear of tunnel boring machine (TBM) cutters are two important parameters commonly used to estimate the boring performance and lifetime of the TBM in the tunneling process. These problems have been investigated by several researchers, whereas the influence of jointed rock mass and mixed ground condition on the cutting efficiency and cutter wear remains insufficiently understood. This study aims to elucidate the influence of rock mass and ground parameters on the cutting efficiency and cutter wear of the TBM by conducting a series of newly developed rolling boring tests on prefabricated joint sandstone samples with different orientations, spacings, and interlayers. Moreover, a numerical simulation is implemented through ANSYS software to verify the rationality of experimental results. The experimental and numerical results indicate that the optimal joint orientation is 30° for the TBM to intrude into a jointed rock mass. As joint spacing increases, the cutting efficiency decreases and the cutter wear increases. Furthermore, specific energy (SE) and cutter wear simultaneously reach their maximum values when the rock abrasivity index (RAI) is 60. Both the specific energy and cutter wear decrease with increasing specific strength. For the rock mass with a soft interlayer in mixed ground, the optimal dip angle is 45°. Additionally, the fitting formulas of SE and cutter wear in mixed ground are proposed to quantitatively illustrate the effect of RAI and interlayer strength on the cutting efficiency and cutter wear. The present study provides an improved understanding of rock-breaking mechanics, thereby making it possible for designers to adjust their design to enhance the TBM cutting efficiency. [ABSTRACT FROM AUTHOR]

• ADAR1 mRNA is downregulated in peripheral blood of aGVHD patients. • ADAR1 binds with the pri-miR-21b to inhibit miR-21b production. • ADAR1 promotes Treg proliferation and immunosuppressive effect. • FOXP3 is a targeted and negatively regulated by miR-21b. • ADAR1 increases Treg proportion and relieves aGVHD in mice. Th17/Treg equilibrium towards the pro-inflammatory Th17 side contributes greatly to the rejection during allogeneic hematopoietic stem cell transplantation (allo-HSCT). Forkhead box P3 (Foxp3) is important in the pathogenic conversion between Th17 and Treg cells. However, how Foxp3 expression was regulated is largely unknown. Here, we investigated the role of RNA-editing enzyme ADAR1 in Foxp3-mediated Th17/Treg imbalance and progression of acute graft-versus-host disease (aGVHD), a most serious complication in patients received allo-HSCT. Th1, Th17 and Treg cells were respectively isolated from peripheral blood CD4 + T cells of allo-HSCT patients, and we found that proportions of Th1 and Th17 were markedly increased, while Treg proportion was significantly decreased in aGVHD patients post transplantation compared with non-aGVHD patients, accompanied by decreased ADAR1 and increased miR-21b levels. RNA-immunoprecipitation (RIP) combined with gain- and loss-of-function experiments demonstrated that ADAR1 improved Treg cell functions and negatively regulated the production of miR-21b, a Foxp3-targeting miRNA. Inhibition of miR-21b improved Treg functions, and Foxp3 knockdown could eliminate the effect of miR-21b inhibition or ADAR1 overexpression on Treg function. Finally, an aGVHD mouse model was established and Ad-O/E-ADAR1 was injected into aGVHD mice to verify the effect of ADAR1 on aGVHD progression in vivo. The results showed that ADAR1 overexpression decreased Th17 proportion and increased Treg proportion in aGVHD mice and obviously improved tissue necrosis and reticular structure of aGVHD liver and lung in vivo. Collectively, ADAR1 suppresses miR-21b production and improves Foxp3-mediated Treg cell function to inhibit the progression of aGVHD after allo-HSCT. [ABSTRACT FROM AUTHOR]

This paper proposes a new comprehensive control strategy to precisely control a piezoelectric positioner by combining discrete-time sliding mode control (DSMC) with the Prandtl-Ishlinskii hysteresis model. In order to obtain precision tracking control, a direct inverse hysteresis compensation method is firstly adopted to compensate for the asymmetric hysteresis nonlinearity. Due to the existence of hysteresis modeling error, the dynamics behavior of the piezoelectric positioner with hysteresis compensation can be treated as a linear second order plant plus an unknown lumped disturbance term. Then a discrete-time sliding mode controller with a disturbance observer is designed to stabilize the position error and improve the position accuracy. The stability of DSMC and the convergence of the disturbance observer are both carried out. It is shown that the tracking performances are robust to the parametric uncertainties and unknown disturbances. Eventually, different trajectory-tracking experiments are performed, and the comparative experimental results are presented to confirm the significantly better performance of the proposed control strategy. [ABSTRACT FROM AUTHOR]

A novel visible-light-driven ZnO/graphite-like carbon (ZnO/g-C) core-shell nanowires (NWs) were synthesized for promoting the separation of electron-hole pairs, enhancing photocatalytic activity and suppressing the photocorrosion. The fireworks-shaped ZnO NWs were firstly prepared by thermal decomposition of zinc acetate dihydrate and then loaded with carbon layer via a microwave-assisted aqueous solution method. The target products were obtained after ZnO/C nanocomposites were graphited at high temperatures. The results revealed that the photocatalytic activity of the ZnO/g-C NWs was 2.4 times as high as that of pure ZnO under UV–vis light irradiation. And the ZnO/g-C NWs showed a dramatic visible light photocatalytic activity under visible light irradiation. The enhanced photocatalytic activity of ZnO/g-C NWs could be explained by the synergistic effect of the ZnO and graphite-like carbon layer. In the same way, a possible mechanism was discussed in order to explain the enhanced photoactivity under visible light irradiation. [ABSTRACT FROM AUTHOR]

Epithelial-to-mesenchymal transition ( EMT) plays a significant role in tubulointerstitial fibrosis, which is a hallmark of diabetic nephropathy. Thus, identifying the mechanisms of EMT activation could be meaningful. In this study, loss of miR-30c accompanied with increased EMT was observed in renal tubules of db/db mice and cultured HK2 cells exposed to high glucose. To further explore the roles of miR-30c in EMT and tubulointerstitial fibrosis, recombinant adeno-associated viral vector was applied to manipulate the expression of miR-30c. In vivo study showed that overexpression of miR-30c suppressed EMT, attenuated renal tubulointerstitial fibrosis and reduced proteinuria, serum creatinine, and BUN levels. In addition, Snail1 was identified as a direct target of miR-30c by Ago2 co-immunoprecipitation, luciferase reporter, and Western blot assays. Downregulating Snail1 by si RNA reduced high glucose-induced EMT in HK2 cells, and miR-30c mimicked the effects. Moreover, miR-30c inhibited Snail1- TGF-β1 axis in tubular epithelial cells undergoing EMT and thereby impeded the release of TGF-β1; oppositely, knockdown of miR-30c enhanced the secretion of TGF-β1 from epitheliums and significantly promoted proliferation of fibroblasts and fibrogenesis of myofibroblasts, aggravated tubulointerstitial fibrosis, and dysfunction of diabetic nephropathy. These results suggest a protective role of miR-30c against diabetic nephropathy by suppressing EMT via inhibiting Snail1- TGF-β1 pathway. [ABSTRACT FROM AUTHOR]

• Evolution of tunnel uplift induced by long and collinear excavation is studied. • An effective protective measure of excavation-induced tunnel uplift is proposed. • The time-dependent excavation-induced tunnel deformation is evaluated. • A well-documented case history is presented. Tunnel uplift control is an important issue for excavation construction near an existing tunnel, especially for long and collinear excavations. In this study, an effective anti-floating measure combining shaft excavation with the frictional pile slab (FPS) was proposed based on a long and collinear foundation pit above existing metro tunnels. The convergence of the shield segments was carefully measured using automatic total stations over 800 days. Numerical simulation was applied to analyze the effect of the width of the shaft excavation and geometric dimension of the frictional pile on the tunnel uplift. Furthermore, a multiobjective optimization procedure was proposed to optimize anti-floating design considering both safety and economy. A comparison between the FPS method and the high-pressure jet-grouting pile (HJP) method shows that the FPS method is a more effective way to control the heave of the underlying tunnel induced by long and colinear excavation due to its small-scale graded unloading and integral portal anti-floating structure. Combining the FPS method with sectional excavation, all the heaves of the underlying tunnel can be controlled to be less than 9 mm. For granite residual strata, the width of shaft excavation is advised to be lower than 8 m, and the length of the frictional pile is suggested to be longer than the distance between the pit bottom and tunnel invert. The heave of the tunnel crown is suggested as the key index to evaluate the excavation-induced disturbance on the underlying tunnel. The unloading ratio and construction time are the key factors that influence the magnitude of tunnel heave. Compared with the actual design, an optimal design with a lower cost and better anti-floating effect is obtained with the proposed multiobjective optimization procedure. The presented tunnel deformation data, advised anti-floating method and construction sequence can provide useful guidance for similar scenarios. [ABSTRACT FROM AUTHOR]

Flower-like ZnO hollow microspheres were synthesized on flexible ceramic mesh substrate using a simple and economical hydrothermal technique and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The photocatalytic reduction of Cr(VI) in leather tannery wastewater by flower-like ZnO hollow microspheres was evaluated under ultraviolet light irradiation for the first time. The addition of different organics and pH value of the reaction solution played important roles in the photocatalytic reduction of Cr(VI). In addition, UV radiation intensity and catalyst content were critical parameters in the photocatalytic reduction process and their effects were also investigated. Under the optimal conditions, ZnO hollow microspheres exhibited excellent removal efficiency of Cr(VI) (~86%) and good photocatalytic stability. Moreover, more than 24% biochemical oxygen demand (BOD 5 ), 32% chemical oxygen demand (COD) and 30% total organic carbon (TOC) of tannery wastewater were reduced significantly after only 180 min of exposure to the UV lamp. It shows much promise to be an attractive photocatalyst for photocatalytic application. [ABSTRACT FROM AUTHOR]

• Warp direction fatigue behaviors of 2.5DSSWCs at various temperatures were investigated. • Fracture morphologies of 2.5DSSWCs at various temperatures were analyzed. • Probable temperature-dependent fatigue damage mechanisms were studied. • Temperature-dependent fatigue life prediction model of 2.5DSSWCs was proposed. • Fatigue lives and damage propagation processes at different temperatures were predicted. When woven composites are used in aeroengine components, it is possible for them to experience high-temperature fatigue loads in service. 2.5D shallow straight-link-shaped woven composites (2.5DSSWCs) are increasingly replacing metal materials in the aeroengine field owing to their excellent fatigue resistance. In this work, warp direction fatigue behaviors of 2.5DSSWCs were experimentally and numerically investigated at 20 °C and 180 °C for the first time. Results show that when temperature is less than 180 °C, the thermo-mechanical properties of 2.5DSSWCs decline with the increase of temperature. However, the strength at 240 °C is totally consistent with that at 180 °C, indicating that the fiber architecture has an important effect on mechanical properties at high temperature. The average fatigue life almost experiences a linear decrease trend with the increase of fatigue load at 180 °C. A fiber-dominated fatigue failure mode without necking phenomenon was observed at 180 °C. Additionally, a temperature-dependent fatigue life prediction model was proposed to predict fatigue behaviors of 2.5DSSWCs at 20 °C and 180 °C. The fatigue failure mechanism was revealed based on test and simulation. Finally, the effects of temperature and warp arranged density on the thermo-mechanical properties were discussed. [ABSTRACT FROM AUTHOR]

• As an emerging atomic spectroscopy technique, laser induced breakdown spectroscopy (LIBS) has great potential for agronomic and environmental applications; • The analysis of nutrition and toxic elements in soil, water, and crops by LIBS are reviewed. • Techniques and methods for enhancing LIBS signal and minimizing matrix effects are presented. • The LIBS advantages, challenges, and limitations of application in agriculture are discussed. In recent years, rapid urbanization and industrialization have caused severe damage to the agro-ecological environment, such as heavy metal pollution of soil, eutrophication, and pollution of water, and excessive harmful substances in crops. Traditional atomic spectroscopy detection techniques, like atomic absorption spectroscopy (AAS), atomic fluorescence spectroscopy (AFS), atomic mass spectrometry (AMS), and X-ray fluorescence spectroscopy (XRFS), enable high-quality detection of agricultural pollution, but they are time-consuming and labor-intensive. Laser Induced Breakdown Spectroscopy (LIBS) technology is widely applied in agro-ecological monitoring because of its strengths in situ and non-destructive, no (little) sample pre-processing, fast and accurate. This review summarizes the applications of LIBS in agriculture in the last five years from 2017 to 2021. The detailed contents of the review are as follow: (a) analysis of soil and fertilizers elemental composition, (b) water quality detection, and (c) pests, diseases, and elements in crops. Lastly, the challenges and developing prospects of LIBS in agriculture are presented. [ABSTRACT FROM AUTHOR]

In this paper, chalcopyrite CuFeS with sheet-like or rod-like morphology has been synthesized by solvothermal reaction route in the presence of poly(vinylpyrrolidone) (PVP). The concentration of PVP has significant influences on the morphology of CuFeS nanocrystals. With the increasing concentrations of PVP, the sheet morphology of CuFeS becomes more uniform. Meanwhile, the average dimensions of CuFeS sheets are reduced and small CuFeS nanoparticles are clearly decreased. When the molar ratio of CuFeS to PVP is 1:2, the shape of CuFeS changes to rod-like, which is composed of CuFeS sheets. Considering the influence of uniformity and shape of CuFeS nanocrystals, the CuFeS nanocrystals with different molar ratios of PVP have been used as active component to prepare anode for Li-ion batteries. The Li-ion battery using CuFeS nanocrystals with the molar ratio of 1:2 to PVP shows the highest reversible specific capacity of ~519 mAh/g after 50 cycles at a current density of 100 mA/g and maintains a specific capacity of ~400 mAh/g at a density of 1000 mA/g. The results demonstrate that the PVP-assisted CuFeS electrodes are promising candidates for use as Li-ion batteries. [ABSTRACT FROM AUTHOR]

In this work, a novel strategy to fabricate ternary MoS 2 /SiO 2 /graphene hybrids (MSGs) was developed by incorporating amorphous SiO 2 with MoS 2 and graphene nanosheets. Serving as anode material in lithium ion batteries, the inert silica component can effectively prevent the pulverization caused by the inner-plane volume expansion of MoS 2 . It turns out that MSGs with ∼40 wt% of SiO 2 and ∼42 wt% of MoS 2 manifest the capacity stabilized at 1060 mAh g −1 for more than 100 cycles at the current density of 0.1 A g −1 . Further, this MSG electrode maintains the specific capacity of 580 mAh g −1 at an ultrahigh current density of 8 Ag −1 , which outperforms those of the reported MoS 2 and MoS 2 /graphene hybrids. [ABSTRACT FROM AUTHOR]

A dragonfly can hover, flap its wings for flight and fly vertically for a short distance. The membranous wings of a dragonfly have a high load-bearing capacity for static and dynamic load during flight. The mass of the wings of a dragonfly is only 1%-2% of its whole body but the wings can stabilize its body. The statics properties of biomimetic models were researched. The finite element software ANSYS was used to simulate the dragonfly wing. The veins were simulated by pipe20 with two nodes and the membranes by shell43 with four nodes. The influence of geometrical nonlinearity was taken into account but material nonlinearity. The models were assumed in the elastic range. The three-dimensional model of the dragonfly wing was reconstructed using reverse engineering software Imageware. The veins of dragonfly wing were drawn with AutoCAD and the membranes were added with ANSYS. The finite element models imitating the dragonfly wing were established by using free meshing. The finite element models of the dragonfly wing were simulated with structural statics. The deformation, the stress and the strain of the models under loads were analyzed respectively. The loads include the uniform load, the bending moment and the torque. Under the uniform load, the deformation of the finite element model imitating a dragonfly wing is very small, and increases gradually from the base to the wing tip. The base of the model bears heavy stress, the middle parts smaller, and the wing tip the least. The strain shows a radial pattern along the longitudinal veins, and reduces gradually from the base to the wing tip of the model. Under the bending moment, the deformation and the rotation angle around y axis increase gradually from the base to the wing tip of the model. The heavy stress and strain are mainly concentrated on the base of the model. The small stress and strain are acted on the middle parts and the wing tip. The distribution trend of the stress and strain is in substantial agreement. Under the torque, the finite element model imitating a dragonfly wing deforms only a little as a whole. The heavy deformation is mainly concentrated on the leading edges and the rear edges of the model. The smaller deformation is acted on the middle parts and the least deformation on the base. The maximum stress and strain occur at the middle parts of the model. The minimum stress and strain occur at the base of the model. The dragonfly wing is a two-dimensional truss structure with excellent rigidity. The dragonfly wing deforms only a little under loads. It is shown that the grid structures of the dragonfly wing deforming together at the boundaries of veins and membranes have excellent integrity. The understanding of dragonfly wings' characteristics provides some reference for improving the properties of two-dimensional composite materials through biomimetic designs. [ABSTRACT FROM AUTHOR]

• The frost resistance durability in aeolian sand concrete at different replacement rates has been discussed from the macroscopic and microscopic perspectives. • The evolution law of freeze–thaw damage characteristics in aeolian sand concrete at both macroscopic and microscopic scales has been studied. • The freeze–thaw damage evolution model for aeolian sand concrete has been established following the continuum damage mechanics and thermodynamics. At present, the existing freeze–thaw damage models are mostly phenomenological damage models that use macroscopic indicators as variables, and there is a lack of a multi-scale freeze–thaw damage model that combines the macroscopic and microscopic perspectives. In this study, eight types of aeolian sand concrete (ASC) at the aeolian sand replacement rates of 0%, 10%, 20%, 30%, 40%, 60%, 80%, and 100% were subjected to freeze–thaw cycle test. Comprehensive analysis and evaluation were done of the frost resistance durability of ASC from the dynamic elastic modulus at the macro-scale and the pore structure at the micro-scale. The evolution law of the freeze–thaw damage characteristics of ASC was studied from a macroscopic and microscopic perspective. The freeze–thaw damage degradation model for ASC was established by transforming the irreversible energy dissipation into cumulative fatigue damage, and the applicability and reliability of the model were verified from the macro and micro multi-scale perspectives. The findings indicate that the introduction of aeolian sand could inhibit and delay concrete damage and deterioration, thus reinforcing the frost resistance durability of concrete. The decrease in the percentage of gel pores and transition pores and the increase in the percentage of large pores deteriorate ASC in freeze–thaw cycles. Whereas, increasing the percentage of gel pores and transition pores and decreasing the percentage of large pores could reinforce the frost resistance of ASC. The damage evolution model can manifest the development law for freeze–thaw deterioration in ASC from the macroscopic and microscopic perspectives. The model can be used as the theoretical foundation for the application of ASC in cold regions. [ABSTRACT FROM AUTHOR]

Based on digital image correlation (DIC) technology and uniaxial compression tests, the deformation evolution characteristics of concrete were analyzed in the heating process under a sustained load and in the failure process under uniaxial compression. The effect of the sustained load on the mechanical properties of concrete at high temperatures was explored. A damage constitutive model of concrete under the combined action of high temperature and the sustained load was established. The research results show that a sustained load can effectively restrain the vertical thermal expansion of concrete and compact loose and weak zones of concrete. However, when the load level or temperature is too high, excessive lateral deformation of concrete will cause local strain concentration and cracking failure. In the failure process under uniaxial compression, both high temperature and sustained load can make the macroscopic cracks more smeared and branched. When the temperature is 200 °C and 400 °C, the sustained load has only a little enhancement effect on the high-temperature mechanical properties of concrete. When the temperature is 600 °C and 800 °C, the sustained load can significantly enhance the mechanical properties of concrete at high temperatures. However, at higher temperatures, excessive sustained loads can cause premature failure of the specimen. Based on the Weibull distribution, a statistical damage constitutive model of concrete under the combined action of sustained load and high temperature is established, which is in good agreement with the test curve. The curve of the degree of damage of concrete D m shows that the sustained load causes the damage D m to start earlier, the damage rate to increase, and the degree of damage at the peak stress to increase in the failure stage under uniaxial compression. [ABSTRACT FROM AUTHOR]

• The pore structure of soil can be accurately assessed by X-ray CT. • The cement can improve the distribution of soil pore structure. • The cement reduces the connectivity of pores and increases isolated pores. • 6% cement content can increase the strength of soil and decrease permeability. Granite residual soil is widely distributed in southeastern China. Notably, this soil easily softens when exposed to water and is easily damaged when subjected to stress, and these characteristics are not conducive to engineering construction and underground space development. In this study, computed tomography(CT), mercury intrusion tests, XRD and SEM techniques are used to examine the improvement of granite residual soil in the Shenzhen area through the addition of cement. The soil micropore structure, saturated permeability coefficient and soil strength characteristics for improved soil specimens with different cement contents (2%, 4%, 6% and 8%) and curing durations (3 d, 5 d and 8 d) are examined. The results show that the pore distribution of granite residual soil has a bimodal structure. In the cement-improved soil, the large pores are eliminated, connectivity of pores is decreased, and number of isolated pores increases. Moreover, the unconfined compressive strength of the improved soil is higher than that of the granite residual soil. The introduction of cement contents of 6% can effectively increase the strength of granite residual soil while decreasing the permeability. [ABSTRACT FROM AUTHOR]

Biodiesel (fatty acid methyl or ethyl esters) is made from vegetable oil or animal fat (triglycerides) reacting with methanol or ethanol using a catalyst (lye). It is safe, biodegradable, and produces less air pollutants than petroleum-based diesel or recycled restaurant greases. With the increasing demand of green energy source and the decreasing of fossil fuel, biodiesel has gained increasing attention as one of the alternative fuels. 100% biodiesel (B100) was used in this study. Experimental samples with water content of 0, 2.50%, 5.00%, 7.50% and 10.0% were set. There were 35 samples for every treatment with different water contents, and total 175 samples. 116 samples were selected for calibration set, and 58 samples for prediction set based with Kennard-Stone (K-S) method. Visible and near infrared spectra (Vis-NIR) technique which was a nondestructive and rapid method, was used to measure the water content in biodiesel. Samples were scanned using the ADS Handheld FieldSpec spectrometer and spectra of samples were acquired. Principal component analysis (PCA) was used to compress spectral data and observe the cluster's situation of biodiesel with different water contents. The scores plot showed a good cluster distribution and the total accumulated variance of PC-1 and PC-2 was up to 99.3%. Random Frog algorithm was applied to extract spectral feature. Then, 8 sensitive wavelengths (563, 560, 642, 565, 562, 493, 559 and 779 nm) were selected respectively. Spectral feature and different water contents were set as input values of partial least squares regression (PLSR) and least squares-support vector machine (LS-SVM) models. It was showed that LS-SVM and PLSR with full spectra had good results, while the variables were too much (116×591) compared with the regression models (116×8). Results of the Random Frog-LS-SVM were better than the Random Frog-PLSR. R of the non-linear LS-SVM models with spectral feature extracted by Random Frog was higher than 0.965, RMSEC of 0.722, RMSEP of 0.520. Sensitive wavelengths extracted were good for eliminating the interfering spectral and improving the accuracy of the model. Results indicated that the Random Frog-LS-SVM as a satisfactory model can measure the water content in biodiesel accurately, which could provide a reference for practical application. [ABSTRACT FROM AUTHOR]

Highlights: [•] Obtain the spectra and image feature of crack jujube based on a Vis/NIR hyperspectral imaging system. [•] Extract characteristic wavebands with chemometrics methods of PLSR, SPCA, SICA. [•] Achieve qualitative discrimination of crack feature using LS-SVM discrimination models with characteristic wavebands. [•] Identify crack feature of fresh jujube using a developed image processing algorithm. [Copyright &y& Elsevier]

A letter to the editor is presented on the nanochemical properties of dragonfly Anax parthenope julius Brauer in the March 24, 2007 issue.

• Providing a novel method to detect determine apple valsa canker (AVC) at different infection stages using molecular vibrational spectroscopy information.Selecting several variables based on x -loadings and CARS algorithm. • Developing LS-SVM models for diagnosing AVC infection stages and using ROC to evaluate models. Detecting of apple valsa canker (AVC), which is caused by Valsa mali Miyabe et Yamada, at early infection stage is beneficial to disease prevention and control for ensuring yield and quality of apples. Applying simple, economical and non-destructive rapid detection method for the early diagnosis of AVC is of great significance for precision management of orchards. In this research, near-infrared (NIR) spectroscopy (900−1700 nm) and Raman scattering (0−2000 cm−1) combined with machine learning algorithms were employed to diagnose 3 infection degrees of AVC (healthy, disease 1, disease 2) based on optimal variables which were selected by chemometric methods. NIR and Raman spectroscopy were obtained using portable spectrometers in reflection mode, respectively. Firstly, adaptive iterative reweighting partial least squares (air-PLS) was utilized to remove fluorescence background in Raman spectra. Secondly, clustering analysis was developed using principal component analysis (PCA). After that, optimal variables were selected by x -loadings (XLs) of PCA and competitive adaptive reweighted sampling (CARS) algorithm, respectively. Four optimal wavelengths at 983, 1156, 1395, and 1457 nm from NIR spectra and five optimal wavenumbers at 175, 229, 326, 409, and 1523 cm−1 from Raman spectra were identified by XLs. Six optimal wavelengths at 943, 949, 967, 1240, 1632, 1666 nm from NIR spectra and eight optimal wavelengths at 412, 1500, 1585, 1596, 1599, 1602, 1672 and 1709 cm−1 from Raman spectra were selected according to CARS. Finally, AVC diagnosing models were developed using least square support vector machine (LS-SVM), and receiver operating characteristic (ROC) curves were applied to evaluate the performance of the classification models. Overall, the relatively good classification results on optimal variables (94.67% and 97.33% in NIR, 89.33% and 89.33% in Raman) were obtained using LS-SVM. This study confirmed that molecular vibrational spectroscopy techniques (NIR and Raman) is promising for early detecting AVC and providing a practical way for diagnosing diseases in large-scale orchards. [ABSTRACT FROM AUTHOR]

With the increasing prevalence and mortality, chronic kidney disease (CKD) has become a world public health problem. As the primary pathological manifestation in CKD, renal fibrosis is often used as a critical target for the treatment of CKD and inhibits the progression of CKD to end-stage renal disease (ESRD). As a potential drug, natural products have been confirmed to have the potential as a routine or supplementary therapy for chronic kidney disease, which may target renal fibrosis and act through various pharmacological activities such as anti-inflammatory and anti-oxidation of natural products. This article briefly introduces the pathological mechanism of renal fibrosis and systematically summarizes the latest research on the treatment of renal fibrosis with natural products of Chinese herbal medicines. [ABSTRACT FROM AUTHOR]

The aim of the study was to investigate the iodine intake in the resident population in Xi'an and analyze the relationship between iodine nutritional status and the prevalence of subclinical hypothyroidism and thyroid nodules (TNs). A total of 2507 people were enrolled in Xi'an. Venous serum thyroid stimulating hormone (TSH), thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb), urinary iodine concentration (UIC), and thyroid ultrasonography were collected. Patients with abnormal TSH were checked for free thyroxine (FT4) and triiodothyronine (FT3). Adults in Xi'an had median UICs of 220.80 μg/L and 178.56 μg/l, respectively. A sum of 16.78% of people had subclinical hypothyroidism. Both iodine excess and iodine deficit increased the frequency of subclinical hypothyroidism. The lowest was around 15.09% in females with urine iodine levels between 200 and 299 μg/l. With a rate of 10.69%, the lowest prevalence range for males was 100–199 μg/l. In Xi'an, 11.37% of people have TNs. In comparison to other UIC categories, TN occurrences were higher in females (18.5%) and males (12%) when UIC were below 100 μg/l. In conclusion, iodine intake was sufficient in the Xi'an area, while the adults' UIC remains slightly higher than the criteria. Iodine excess or deficiency can lead to an increase in the prevalence of subclinical hypothyroidism. Patients with iodine deficiency are more likely to develop TNs. [ABSTRACT FROM AUTHOR]

Background: Alzheimer's disease (AD), the most common form of dementia, remains long-term and challenging to diagnose. Furthermore, there is currently no medication to completely cure AD patients. Rapamycin has been clinically demonstrated to postpone the aging process in mice and improve learning and memory abilities in animal models of AD. Therefore, rapamycin has the potential to be significant in the discovery and development of drugs for AD patients. Objective: The main objective of this systematic review and meta-analysis was to investigate the effects and mechanisms of rapamycin on animal models of AD by examining behavioral indicators and pathological features. Methods: Six databases were searched and 4,277 articles were retrieved. In conclusion, 13 studies were included according to predefined criteria. Three authors independently judged the selected literature and methodological quality. Use of subgroup analyses to explore potential mechanistic effects of rapamycin interventions: animal models of AD, specific types of transgenic animal models, dosage, and periodicity of administration. Results: The results of Morris Water Maze (MWM) behavioral test showed that escape latency was shortened by 15.60 seconds with rapamycin therapy, indicating that learning ability was enhanced in AD mice; and the number of traversed platforms was increased by 1.53 times, indicating that the improved memory ability significantly corrected the memory deficits. CONCLUSIONS: Rapamycin therapy reduced age-related plaque deposition by decreasing AβPP production and down-regulating β-secretase and γ-secretase activities, furthermore increased amyloid-β clearance by promoting autophagy, as well as reduced tau hyperphosphorylation by up-regulating insulin-degrading enzyme levels. [ABSTRACT FROM AUTHOR]

Detection and characterization of interactions between crop plants and hydrogen peroxide (H 2 O 2) is significant for the exploration of the mechanisms in plant pathology. The objective of this research is to estimate spectral characteristics of rapeseed leaves (Brassica napus L.) during treatment with different H 2 O 2 concentrations (0, 0.5, 1.0, and 3.0 mmol/L) by using Raman spectroscopy (RS) (800–1800 cm−1) and hyperspectral imaging (HSI) (400–1000 nm). Cluster analysis of RS and HSI data between the control and treated samples was conducted using kernel principal component analysis (KPCA) and principal component analysis (PCA), respectively. Characteristic Raman shifts at 1012, 1163, and 1530 cm−1 and hyperspectral featured wavelengths at 452, 558, 655, and 703 nm were selected for discriminating control and treated samples. The one-way analysis of variance (ANOVA) was applied to demonstrate the significant difference in spectral signatures of samples, and results showed that 452 nm is promising to assess the control and treated samples at the p < 0.05 level. The featured Raman shifts and hyperspectral wavelengths were employed to establish least squares-support vector machine (LS-SVM) discriminative models. The approach of multiple-level data fusion of 1163 cm−1 combined with 452 nm produced the best recognize rate (RR) of 81.7% to detect the control and treated leaves than other models. Therefore, the results encouraged multiple sensor fusion to improve models for better model performance and to detect plant treatment situations with H 2 O 2 solutions. Unlabelled Image • Providing a method to determine hydrogen peroxide treatment of plant leaves using Raman spectroscopy and hyperspectral information. • KPCA and PCA provided good cluster results based on Raman shift and hyperspectral data between controlled and treated samples. • Multiple level data fusion of 1163 cm-1 combined with 452 nm produced the better recognize rate of 81.7%. [ABSTRACT FROM AUTHOR]

Optimization of testing parameters are the prerequisite for laser induced breakdown spectroscopy (LIBS) further data analysis, which can offer important reference value for the soil detection in the field. This work investigated the influence of the main testing parameters laser energy (LE), delay time (DT), and lens to sample distance (LTSD) of LIBS system. Based on the spectral characteristic of main elements in soils, the testing parameters of LIBS for soil detection were obtained and verified. The optimization analysis of three testing parameters LE (50–160 mJ), DT (0.5–4.5 μs), and LTSD (94–102 mm) were conducted by response surface methodology (RSM). Central composite design (CCD) in RSM was introduced to carry out experimental runs. The combined signal-background-ratio (SBR) of characteristic spectral lines from main elements (Si, Fe, Mg, Ca, Al, Na, K, etc.) in soil were defined as the objective function (named Y SBR). The interaction influences among three independent variables (LE, DT, and LTSD) on soil plasma characteristics were explored and the optimized testing parameters of LIBS were summarized. Results revealed as follows: the factor LE showed a remarkable linear effect to Y SBR , and factors DT and LTSD exhibited opposite results. The interactive items of three factors displayed a non-significant relationship. Meanwhile, the quadratic items of LE2, DT2 and LTSD2 offered significant surface relationships. Through the RSM analysis, the optimized testing parameters for LIBS soil detection were LE: 103.09 mJ; DT: 2.92 μs; LTSD: 97.69 mm; and a peak value Y SBR of 198.60. After that, the LIBS data of 21 representative soil samples were collected under the optimized LIBS testing parameters. Partial least squares regression (PLSR) was introduced to predict the main elemental contents. Results indicated that PLSR models offered promising outputs for predicting the contents of Al, Ca, Fe, K, Mg, and Na in the sampled soil, which revealed that the testing parameters of LIBS optimized by RSM were available. This work provided a theoretical basis for the accurate LIBS data analysis and regarded as a technical support for the field soil LIBS testing parameters selection. • Carry out the three factors (LTSD, DT, and LE) experimental design using central composite design (CCD) based RSM. • Structure an objective function based on signal-background-ratio (SBR) of characteristic spectral lines of main elements in soil. • Reveal the interaction effects among three factors on soil plasma characteristics. • Verify the optimized testing parameters based on quantitative analysis of multi-elements content in soil. [ABSTRACT FROM AUTHOR]

• Assessed was the blueberry buds damage due to lab-simulated freezing events. • Buds were imaged at bud swell and early pink stages in 2017 and 2018 season. • Salient wavelengths were selected using principal component analysis and successive projection algorithm technique. • Partial least squares discriminant analysis classifier evaluated the robustness of salient wavelengths. The floral tissue of blueberry buds is very sensitive to the freezing and can be damaged during early spring freeze events. Such damage results in loss of yield to the commercial blueberry producers. Therefore, this study investigated the feasibility of injured blueberry buds damage detection during early spring freeze using hyperspectral imaging (HSI) technique. Imaged were the buds from bud swell and early pink stage for two growing seasons. Prior to imaging, buds in 2017 were subjected to freezing temperatures of −7 to −16 °C and −2 to −11 °C at respective growth stages. In 2018 season, buds were frozen at −11 to −20 °C and −4 to −13 °C at two respective sampling date for bud swell stage and at −2 to −11 °C for early pink growth stage. The HSI data was obtained using a push broom type system in the spectral wavelength ranges of 517–1729 nm. For the imaged buds, each of the indivisual buds on sampled shoot was considered as one sample, and the average spectra of such bud within 540 to 1599 nm was extracted for further analysis. Principal component analysis and successive projection algorithms were applied to select key wavelengths related to bud damage symptoms. Common wavelengths of 615, 673, 690, 756, 979 and 1467 nm were identified for both the growth stages. Partial least squares discriminant analysis was performed to identify normal and injured bud samples with the selected common wavelengths. Performance of the models manifested good results with better sensitivity (>0.80), specificity (>0.75), the area under the receiver operating characteristic curve (>0.84) and accuracy (>0.75) attributes for 2017, 2018 seasons and two seasons combined test dataset. [ABSTRACT FROM AUTHOR]

Background: Metabolic abnormalities have been implicated as a causal event in diabetic cardiomyopathy (DCM). However, the mechanisms underlying cardiac metabolic disorder in DCM were not fully understood. Results: Db/db mice, palmitate treated H9c2 cells and primary neonatal rat cardiomyocytes were employed in the current study. Microarray data analysis revealed that PGC-1β may play an important role in DCM. Downregulation of PGC-1β relieved palmitate induced cardiac metabolism shift to fatty acids use and relevant lipotoxicity in vitro. Bioinformatics coupled with biochemical validation was used to confirm that PGC-1β was one of the direct targets of miR-30c. Remarkably, overexpression of miR-30c by rAAV system improved glucose utilization, reduced excessive reactive oxygen species production and myocardial lipid accumulation, and subsequently attenuated cardiomyocyte apoptosis and cardiac dysfunction in db/db mice. Similar effects were also observed in cultured cells. More importantly, miR-30c overexpression as well as PGC-1β knockdown reduced the transcriptional activity of PPARα, and the effects of miR-30c on PPARα was almost abated by PGC-1β knockdown. Conclusions: Our data demonstrated a protective role of miR-30c in cardiac metabolism in diabetes via targeting PGC-1β, and suggested that modulation of PGC-1β by miR-30c may provide a therapeutic approach for DCM. [ABSTRACT FROM AUTHOR]

[Display omitted] • Acquisition of rapid response curves and spectral peak attribution of samples. • Rapid detection of Cu stress level by SERS and SAE-CNN model. • TEM confirmed that excessive copper damaged the cell structure of apple rootstock. Copper-containing chemicals are commonly used in orchard management, and their use over a long time causes excessive copper content in orchard soil. Surface-enhanced Raman spectroscopy (SERS) technique combined with deep learning (DL) methods were used to characterize the response of apple rootstocks under heavy metal Cu stress. The hydroponic method prepared Apple rootstocks under five concentration gradients of heavy metal Cu stress as the experimental samples. The Raman spectral data were collected and subjected to spectral preprocessing. A stacked auto-encoder convolutional neural network (SAE-CNN) model was used to develop a rapid discriminative model for root, stem, and leaf stress levels of heavy metal Cu on apple rootstocks. The SAE-CNN models all outperformed the traditional models, with performance metrics above 99%. The results showed that the proposed SAE-CNN model could rapidly discriminate heavy metal Cu in apple rootstocks. [ABSTRACT FROM AUTHOR]

[Display omitted] • HSI and CNN models for rapid detection of heavy metal Cu contamination levels in apple rootstocks. • The CNN model showed superior performance in all aspects compared to the conventional model. • PCA and t-SNE data visualization for model validation. In recent years, the prolonged application of copper-based fungicides, ripening agents, and fertilizers in agricultural activities has resulted in copper (Cu) levels in the soil exceeding safe levels. Excess Cu has a negative impact on plant growth and crop yields. The practice of grafting horticultural crops onto appropriate rootstocks is frequently employed as a preventive measure against copper accumulation and its associated toxicity. Therefore, the selection of high-quality rootstocks that are not contaminated with heavy metal Cu is important for the growth of grafted crops and the breeding of grafted crops. This study proposed a technique based on convolutional neural network (CNN) and hyperspectral imaging (HSI) for the rapid, non-destructive, and accurate identification of copper contamination levels in apple rootstocks. The effect of different heavy metal Cu contamination levels on leaves was obtained by measuring chlorophyll content in leaves using the ultraviolet spectrophotometer method. A hybrid strategy for spectral variable selection was utilized, involving competitive adaptive reweighted sampling and successive projection algorithms. A traditional partial least squares discriminant analysis linear classification model, and least squares support vector machine, random forest, and extreme learning machine nonlinear models were developed. The results showed that the accuracy of the CNN model and Macro-F1 were 99.6% and 99.2%, respectively, which were better than the traditional linear and nonlinear models. Principal component analysis and t-distributed stochastic neighbor embedding were used for visual analysis to investigate the clustering patterns among sample classes. The results indicated that the combination of CNN and HSI techniques has great potential for classifying copper contamination levels in apple rootstocks. [ABSTRACT FROM AUTHOR]

Heavy metal lead (Pb) accumulation in agricultural soil has become a serious threat to human health through the food chain in recent decades. Wheat, being one of the most important crops, is a crucial source of food for humans. Pb in soil can pose a significant risk to the wheat grain, as it can be transported through the root and stem. This transportation not only increases the Pb concentration in wheat, but also threatens the wheat's overall food security. Therefore, it is imperative to investigate the effects of Pb stress on wheat seedlings. Double-pulse laser-induced breakdown spectroscopy (DP-LIBS) and surface-enhanced Raman spectroscopy (SERS) as promising enhanced spectroscopy techniques were coupled to estimate Pb stress in wheat seedlings. Wheat seedling samples under Pb stress at 6 concentration gradients (0(c.k.), 500, 1000, 2000, 3000, and 5000 mg L−1) were cultivated with the same substrate and management. The SERS and DP-LIBS spectra of the root, stem and leaf were obtained by using spectrometers in an enhanced way. Principal component analysis (PCA) was employed for preliminary analysis of DP-LIBS and SERS data to investigate the clustering of samples, including substrates and the wheat seedling root and leaf, under different Pb concentration stresses. However, while PCA enabled the rough differentiation of the samples, the classification accuracy requires improvement. The pre-processed SERS, DP-LIBS, and fusion spectral data (LIBS-Raman) were analyzed using discriminant models such as least squares support vector machines (LS-SVM), multi-layer perceptron-artificial neural network (MLP-ANN), radial basis function-artificial neural network (RBF-ANN) and probabilistic neural networks (PNN). The accuracy of the model built by LIBS-Raman was significantly better than the model built based on SERS and DP-LIBS data alone. LIBS-Raman increased the accuracy of the discrimination model, which highlights the effectiveness of collaborative spectroscopic methods for heavy metal detection. This study investigated the migration of Pb in the substrate-root-leaf. At 0 concentration (c.k.), Pb was not detected in the substrate and wheat seedling root and leaf. At the same concentration, the level of Pb stress in the root was higher than that in the leaf. This might be attributed to the self-protection mechanism of wheat seedlings, which had a weak ability to transport Pb ions. This work provides theoretical support for collaborative spectral data, furnishes a reference for the development of a combined spectrometer, and offers a valuable method for monitoring heavy metal contamination in plants. [ABSTRACT FROM AUTHOR]

• The flexural fatigue life of aeolian sand concrete is analyzed by using two-parameter Weibull distribution. • The double logarithmic fatigue equations of freeze–thaw-damaged aeolian sand concrete under different failure probabilities are established. • The fatigue damage evolutions of aeolian sand concrete after freeze–thaw cycle are studied. Aeolian sand is abundant and is widely distributed in western China and thus can reduce the project cost, alleviate the consumption of river sand resources, as well as protect the ecological environment in the application of concrete. Concrete structures, such as roads, bridges, and airport runways in northern cold regions, are exposed to the combined action of freeze–thaw cycle and fatigue load, and the damage mechanism is more serious and complex than that under a single factor. In the present study, the flexural fatigue behavior and damage evolution of aeolian sand concrete under freeze–thaw cycles are studied. Results show that freeze–thaw damage aggravates the flexural fatigue failure of concrete with aeolian sand, and the addition of aeolian sand enhances the average fatigue life of concrete after freeze–thaw cycle. The fatigue life of concrete that has aeolian sand content of 100% is improved more significantly than that of concrete with aeolian sand content of 50%. A double logarithmic fatigue equation is established for varying numbers of freeze–thaw cycles and different failure probabilities. Additionally, the course of flexural fatigue strain and fatigue modulus of aeolian sand concrete under freeze–thaw cycle action follows a typical three-stage development course. The effects of freezing and thawing action on fatigue behavior, such as fatigue strain growth, stiffness degradation, stress–strain relationship, and dissipated energy of 50% aeolian sand concrete (ASC50), are more significant, whereas the effects of 50 and 100 freeze–thaw cycles on the fatigue properties of 100% aeolian sand concrete (ASC100) are not evident. The research results are of great significance for the popularization and use of aeolian sand concrete in cold regions. [ABSTRACT FROM AUTHOR]

Encapsulating peritoneal sclerosis (EPS) is an uncommon and harmful complication which may cause destructive outcomes. Matrix metalloproteinase-2 (MMP-2) as a protease can reduce constituents of the extracellular matrix and play a crucial role in the progression of EPS. As a new biomarker, MMP-2 may improve the detection rate of EPS patients in clinical work. In this review, we summarize the recent study of MMP-2 in different etiologies and the assessment of its application value and draw attention to its future directions. [ABSTRACT FROM AUTHOR]

Abstract Herbal medicine (HM), derived from various therapeutic plants, has garnered considerable attention for its remarkable effectiveness in treating diseases. However, numerous issues including improved varieties selection, hazardous residue detection, and concoction management affect herb quality throughout the manufacturing process. Therefore, a practical, rapid, nondestructive detection technology is necessary. Terahertz (THz) spectroscopy, with low energy, penetration, and fingerprint features, becomes preferable method for herb quality appraisal. There are three parts in our review. THz techniques, data processing, and modeling methods were introduced in Part I. Three primary applications (authenticity, composition and active ingredients, and origin detection) of THz in medicinal plants quality detection in industrial processing and marketing were detailed in Part II. A thorough investigation and outlook on the well-known applications and advancements of this field were presented in Part III. This review aims to bring new enlightenment to the in-depth THz application research in herbal medicinal plants. [ABSTRACT FROM AUTHOR]

Tree diseases endanger forestry and fruit tree plantations seriously worldwide in the past decades, leading to significant economic losses for the agricultural production sector. Rapid and accurate detection of tree diseases is crucial in tree protection. Despite molecular biological detection methods have prominent specificity, they are time-consuming and laborious, and are not suitable for large-scale detection of tree diseases. Spectroscopy with nondestructive, rapid, and high throughput characteristics has been applied to plant disease detection. Spectral detection systems are divided into three categories according to the spectrometer's carrying platform: portable hand-held spectrometer, airborne vehicle-mounted spectrometer, and large laboratory spectrometer. This review summarized three main spectral detection systems and their advantages and disadvantages in detecting various diseases of forestry and fruit trees: including detection of the single disease, multiple stress, and early disease using Visible/near-infrared, Raman, and hyperspectral imaging. Finally, spectroscopy detection technology applications of challenges were summarized, highlighting future trends. [ABSTRACT FROM AUTHOR]

Aims: Krüppel-like Factor 9 (KLF9) is a transcription factor that regulates multiple disease processes. Studies have focused on the role of KLF9 in the redox system. In this study, we aimed to explore the effect of KLF9 on diabetic cardiomyopathy. Methods and Results: Cardiac-specific overexpression or silencing of KLF9 in C57BL/6 J mice was induced with an adeno-associated virus 9 (AAV9) delivery system. Mice were also subjected to streptozotocin injection to establish a diabetic cardiomyopathy model. In addition, neonatal rat cardiomyocytes were used to assess the possible role of KLF9 in vitro by incubation with KLF9 adenovirus or small interfering RNA against KLF9. To clarify the involvement of peroxisome proliferator-activated receptors (PPARγ), mice were subjected to GW9662 injection to inhibit PPARγ. KLF9 was upregulated in the hearts of mice with diabetic cardiomyopathy and in cardiomyocytes. In addition, KLF9 overexpression in the heart deteriorated cardiac function and aggravated hypertrophic fibrosis, the inflammatory response and oxidative stress in mice with diabetic cardiomyopathy. Conversely, cardiac-specific silencing of KLF9 ameliorated cardiac dysfunction and alleviated hypertrophy, fibrosis, the cardiac inflammatory response and oxidative stress. In vitro, KLF9 silencing in cardiomyocytes enhanced inflammatory cytokine release and oxidative stress; KLF9 overexpression increased these detrimental responses. Moreover, KLF9 was found to regulate the transcription of PPARγ, which suppressed the expression and nuclear translocation of nuclear Factor E2-related Factor 2 (NRF2). In mice injected with a PPARγ inhibitor, the protective effects of KLF9 knockdown on diabetic cardiomyopathy were counteracted by GW9662 injection. Conclusions: KLF9 aggravates cardiac dysfunction, the inflammatory response and oxidative stress in mice with diabetic cardiomyopathy. KLF9 may become a therapeutic target for diabetic cardiomyopathy. [ABSTRACT FROM AUTHOR]

Heavy metal pollution in agriculture is a significant problem that endangers human health. Laser-induced breakdown spectroscopy (LIBS) is an emerging technique for material and elemental analysis, especially heavy metals, based on atomic emission spectroscopy. The LIBS technique has been widely used for rapid detection of heavy metals with its advantages of convenient operation, simultaneous detection of multi-elements, wide range of elements, and no requirement for the state and quantity of samples. However, the development of LIBS is limited by its detection sensitivity and limit of detection (LOD). Therefore, in order to improve the detection sensitivity and LOD of LIBS, it is necessary to enhance the LIBS signal to achieve the purpose of detecting heavy metal elements in agriculture. This review mainly introduces the basic instruments and principles of LIBS and summarizes the methods of enhanced LIBS signal detection of heavy metal elements in agriculture over the past 10 years. The three main approaches to enhancing LIBS are sample pretreatment, adding laser pulses, and using auxiliary devices. An enhanced LIBS signal may improve the LOD of heavy metal elements in agriculture and the sensitivity and stability of the LIBS technique. The enhanced LIBS technique will have a broader prospect in agricultural heavy metal monitoring and can provide technical support for developing heavy metal detection instruments. [ABSTRACT FROM AUTHOR]