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Accurate, timely, and fine-resolution crop phenology is essential for determining the optimal timing of agronomic management practices supporting precision agriculture and food security. Synthetic Aperture Radar (SAR) methods, unaffected by cloud occlusion, have been widely applied in monitoring maize phenology. Nonetheless, their reliance on manual threshold settings, which depend on the user's expertise, limits their applicability. Furthermore, the neglect of SAR's potential for monitoring other phenological periods (e.g., seven-leaves date (V7), jointing date (JD), tassel date (TD), and milky date (MID)) hinders their robustness, particularly for regional-scale applications. To address these issues, this study used an adaptive dynamic threshold to evaluate the ability of the Sentinel-1 cross-polarization ratio (CR) in detecting the three-leaves date (V3), V7, JD, TD, MID, and maturity date (MD) of maize. We analyzed the effect of incidence angle, precipitation, and wind speed on Sentinel-1 features to identify the optimal feature for time series fitting. Then, we employed linear regression to determine the optimal threshold and developed an adaptive dynamic threshold for phenology detection. This approach effectively mitigated the speckle noise of Sentinel-1 and minimized artificial interference caused by customary conventional thresholds. Finally, we mapped phenology across 8.3 million ha in Heilongjiang Province. The results indicated that the approach has a higher ability to detect JD (RMSE = 11.10 d), MID (RMSE = 10.31 d), and MD (RMSE = 9.41 d) than that of V3 (RMSE = 32.07 d), V7 (RMSE = 56.37 d), and TD (RMSE = 43.33 d) in Sentinel-1. Compared with Sentinel-2, the average RMSE of JD, MID, and MD decreased by 4.14%, 35.28%, and 26.48%. Moreover, when compared to different thresholds, the adaptive dynamic threshold can quickly determine the optimal threshold for detecting each phenological stage. CR is least affected by incident angle, precipitation, and wind speed, effectively suppressing noise to reflect phenological development better. This approach supports the rapid and feasible mapping of maize phenology across broad spatial regions with a few samples. [ABSTRACT FROM AUTHOR]

Spatiotemporal fusion (STF) is crucial for reconciling the conflict between temporal and spatial resolutions of remote sensing observations. However, fusing images in heterogeneous areas remains challenging under continuous missing values. Moreover, most current STF methods only consider temporal errors and disregard the spatial scale error in time variation. Therefore, we proposed a Quick Spatiotemporal Fusion with Coarse- and Fine-Resolution Scale Transformation Errors and Pixel-Based Synthesis Base Image Pair (STEPSBI). First, the optimal pixel-based image synthesis strategy was designed using all available fine- and coarse-resolution images. Then, the scale transformation error (STE) of coarse-resolution downscaling to fine-resolution in temporal variation was quantified. And a residual term was introduced to reduce the prediction error from the temporal variation. Finally, the spatial scale and temporal errors were corrected using the results of super-pixel segmentation as spatial weights. This model has two strengths: (1) Pixel-based image synthesis alleviates the absence of base images under continuous missing values; and (2) STE correction restores spatial details of heterogeneous areas in rapid land cover change. In scenarios of continuous missing images, abrupt land cover changes, and high-resolution heterogeneity, we evaluated STEPSBI, the Gap Filling and Savitzky–Golay filtering method (GF-SG), the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM), the Flexible Spatiotemporal DAta Fusion (FSDAF), the cross-attention-based adaptive weighting fusion network (CAFE), and the Multi-scene Spatiotemporal Fusion Network (MUSTFN). The results indicate that STEPSBI yields better overall performance than other models in cropland, woodland, grassland, and other land cover types. Furthermore, ablation experiments demonstrated that each component improved the model's performance. In addition, STEPSBI had higher fusion efficiency because it was developed on the Google Earth Engine cloud computing platform. Therefore, STEPSBI was feasible for advancing fine monitoring of spatiotemporal image fusion under continuous missing values and heterogeneous surfaces. The program of STEPBSI is freely available at: https://code.earthengine.google.com/684844aa42f64fa6b4eebe3bc0dd6483. [ABSTRACT FROM AUTHOR]

Oyster is nutritious shellfish, wildly consumed throughout the world. Its polysaccharide (OPS) has various bioactivity. In the present study, the anti-obesity effect of OPS was evaluated in obese mice induced by a high-fat diet (HFD). The results showed that OPS significantly alleviated weight gain, dyslipidemia, and metabolic endotoxemia of obese mice, and accelerated the production of short-chain fatty acids. OPS also regulated lipid metabolism of adipose and liver by activating the expression of p-AMPKα to further down-regulate the expression of SREBP-1c, PPARγ, and p-ACC-1. 16S rRNA results indicated that OPS corrected HFD-induced gut microbiota dysbiosis by enriching beneficial bacteria (Bifidobacterium , Lactobacillus , Dobosiella , and Faecalibaculum) and decreasing harmful bacteria (Erysipelatoclostridium , Helicobacter , and Mucispirillum). In summary, these results revealed that OPS could serve as a potential prebiotic to improve obesity. • Oyster polysaccharides (OPS) attenuated high-fat-diet (HFD)-induced mice obesity. • OPS alleviated the lipid metabolism disorder induced by HFD. • OPS improved gut microbiota dysbiosis and increased the production of SCFAs. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the molecular mechanism by which polysaccharides from Crassostrea gigas (RPS) prevent alcoholic liver injury and to uncover whether the steaming process affects the bioactivities of RPS. Oral administration of RPS or polysaccharides from steamed oyster (SPS) (282 mg/kg b.w.) significantly attenuated alcoholic liver injury in mice. RPS and SPS treatments protected gut functions by significantly enhancing the expression of tight-junction proteins and suppressing inflammatory responses. RPS and SPS treatments also significantly increased Lactobacillus reuteri and Roseburia spp. and decreased the level of Escherichia. Microbial metabolites, especially propionate and butyrate, were also increased in RPS- and SPS-treated mice. Correlation analysis revealed that the beneficial effects of RPS and SPS were strongly correlated with the microbiota composition and SCFAs. These results indicated that oyster polysaccharides alleviated alcoholic liver injury by mediating the gut-liver-metabolite axis, and the steaming process had little influence on the bioactivity. • Oyster polysaccharides attenuated alcoholic hepatosteatosis via microbiome-liver axis. • Oyster polysaccharides treatment increased the level of Lactobacillus _ reuteri. • Oyster polysaccharides supplementation decreased the level of Escherichia. • Steaming process has little influence on its bioactivities. [ABSTRACT FROM AUTHOR]

• HHP reduced the IgG binding capacity of TM from Pacific oysters. • 600 MPa was the optimal pressure for reducing the immunoreactivity of TM. • The α-helix content of HHP-treated TM was decreased. • The tertiary structure of TM was changed after HHP treatment. To investigate the effects of high hydrostatic pressure (HHP) on the conformation and IgG binding capacity, tropomyosin (TM) from Pacific oysters was subjected to high pressures of 300, 450 or 600 MPa. The results showed that the α-helix of TM with HHP-induced was decreased, while β-turn, β-sheet (predominantly) and random coil were increased. The surface hydrophobicity and sulfhydryl group content of TM were increased, while the fluorescence/UV intensity were decreased after HHP treatment. Atomic force microscopy (AFM) result exhibited that the morphology of TM was changed at 600 MPa and formed fibrous structures. The IgG binding capacity of TM and digested TM was markedly reduced when the pressure was increased, especially at 600 MPa. Overall, this study indicated that HHP-induced conformational changes in TM contributed to the reduction in IgG binding capacity. These findings suggested that HHP may be a promising non-thermal technology for producing hypoallergenic oyster products. [ABSTRACT FROM AUTHOR]

[Display omitted] • Loading of oyster hydrolysate into the chitosan-coated nanoliposomes was performed. • The chitosan coating improves the physical stability and EE of the nanoliposomes. • The chitosan coating delayed the release rate of OPH during the digestive process. • The stability of nanoliposomes after spray/freeze drying was evaluated. Oyster protein hydrolysate (OPH) has high bioactivity and excellent performance, but its application in food formulation is still limited due to poor flavor and instability. In the present study, OPH was prepared by enzymatic hydrolysis and loaded into nanoliposomes. Then, the effects of chitosan coating (0, 0.25, 0.5, and 1.0%) on the physical properties, stability, and antioxidant activity were evaluated. The results showed that 1% chitosan-coated nanoliposomes had high encapsulation efficiency (EE) and physical stability. Additionally, chitosan coating slowed the release rate of nanoliposomes and increased the retention rate of antioxidant activity of OPH. The stability of the uncoated/coated nanoliposomes in a maltodextrin matrix by spray/freeze drying was evaluated. FTIR spectrum showed that hydrogen bonds, hydrophobic, and electrostatic interactions had been formed between chitosan-coated nanoliposomes and maltodextrin. Chitosan coating significantly improved the physical stability and antioxidant activity retention of nanoliposomes during powder reconstitution. [ABSTRACT FROM AUTHOR]

• Higher concentration of κ-carrageenan accelerated the gelation of oyster protein. • The κ-carrageenan increased the gel strength of oyster protein (OP). • OP/κ-carrageenan gel had more compact network structure compared with OP. Proteins and polysaccharides commonly coexist in the food system, forming complexes and coacervates to make tailor-made food. In this study, the effects of κ-carrageenan on the rheological behavior, network structure, textures, and molecular force of oyster protein (OP treated with high-pressure homogenization were investigated. Rheological results showed that κ-carrageenan improved the storage modulus of OP, and the higher concentration of κ-carrageenan accelerated the gelation of OP. The second derivative of infrared spectroscopy revealed that κ-carrageenan contributed to the formation of β-sheet in OP. Molecular force and texture analysis showed that κ-carrageenan might promote the increase of hydrophobic bonds and disulfide bonds, which was helpful to enhance gel strength. The microstructure showed that the OP gel with 1.5% κ-carrageenan had a compact network structure with abundant minor mesh and sheet edge. This study reveals the gelation mechanism of OP/κ-carrageenan and provides the theoretical basis for developing innovative oyster products. [ABSTRACT FROM AUTHOR]

The purpose of this study was to explore the effect of gelatin on the formation of oyster protein gel and reveal the interaction mechanism between gelatin and oyster protein. In the present study, the oyster protein (OP 100) was obtained after being high pressure homogenized (100 MPa) and subsequently reconstituted with different concentrations (0, 2.0, 4.0, 6.0, and 8.0%) of gelatin. The rheological results showed that gelatin improved the storage modulus of OP 100 , and accelerated the gelation of OP 100 during the cooling period. Moreover, gelatin improved the gel strength and texture properties of OP 100. Infrared scanning indicated that new hydrogen bonds and β-sheets structures had been formed between the OP 100 and gelatin. Molecular force results showed that hydrophobic interaction, hydrogen bonds, and disulfide bonds were the main molecular forces of the OP 100 /gelatin composite gel. These results provide a new reference for developing oyster protein nutritional gel products and reveal that gelatin can improve the texture properties of oyster protein gel. • Gelatin and oyster protein exhibited synergistic gelation. • Gelatin significantly improved the texture properties of oyster protein gel. • The mechanism of interaction between gelatin and oyster protein was evaluated. [ABSTRACT FROM AUTHOR]

[Display omitted] • Oyster polysaccharide (OPS) could be partially degraded during simulated digestion in vitro. • The indigestible OPS could be degraded and utilized by gut microbiota. • Indigestible OPS could regulate gut microbiota. • The fermentation of indigestible OPS promoted the production of SCFAs. Oyster is a kind of nutritious shellfish widely consumed globally, and its polysaccharide (OPS) has been verified to have strong functional activity. However, it is still unclear about the specific digestion and prebiotic properties of OPS. In the present study, the digestion and fermentation properties of OPS and its effect on gut microbiota were evaluated using simulated digestion (saliva, stomach, and small intestine) and fermentation models in vitro. The results showed that the molecular weight (Mw) of OPS decreased from 5.73 × 106 to 4.35 × 106 Da, and the reducing sugar content increased from 0.043 to 0.096 mg/mL, indicating that OPS was partially degraded during the saliva-gastrointestinal digestion. During fermentation, the Mw and carbohydrate residue of indigestible OPS (OPSI) decreased, and free monosaccharides were released, suggesting that OPSI could be further degraded and utilized by gut microbiota. Notably, OPSI could regulate the composition and diversity of the microbial community, especially increase the abundance of beneficial bacteria such as Bacteroides , Prevotella , and Faecalibacterium. Additionally, after fermentation for 24 h, OPSI promoted the production of short-chain fatty acids (SCFAs), and acetic acid, propionic acid, and n-butyric acid were the main metabolites. These results provided a reference for the digestive characteristics of OPS and revealed that OPS might be a potential prebiotic to prevent diseases by improving intestinal health. [ABSTRACT FROM AUTHOR]

High hydrostatic pressure (HHP) treatment is a non-thermal processing technology, which is widely used in the food processing field at present. In this study, the effects of HHP treatment (100~500 MPa for 5 min) on the physicochemical properties, texture parameters, and volatile flavor compounds of oysters were investigated. The results showed that HHP treatment increased the water content while reducing the crude protein and ash content of the oyster. Texture parameters showed that HHP treatment improved the hardness, springiness, chewiness, and cohesiveness of oysters, compared with the control group. In addition, the saturated fatty acid (SFA) content was slightly increased after HHP treatment, while the difference in monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) content was not significant. Furthermore, HHP increased hexenoic aldehyde, 2,4-heptadienal, 1-octene-3-ol, and 2-octen-1-ol and decreased the contents of 3. 6-nadien-1-ol, 3-octanone, and 2-undecanone, suggesting that HHP might inhibit the fishiness of oyster and showed a positive effect on its flavor. Based on the above results, HHP improved the edible qualities such as texture properties and volatile flavor of oysters. This meets the requirements of consumers on the edible quality of seafood and provides new ideas for the development of seafood. [ABSTRACT FROM AUTHOR]

The redistribution of solar radiation, temperature, soil moisture and heat by topography affects the physical and chemical properties of the soil and the spatial distribution characteristics of crop growth. Analyses of the relationship between topography and these variables may help to improve the accuracy of digital elevation models (DEMs). The purpose of correcting Shuttle Radar Topography Mission (SRTM) data is to obtain high-precision DEM data in cultivated land. A typical black soil area was studied. A high-precision reference DEM was generated from an unmanned aerial vehicle (UAV) and extensive measured ground elevation data. The normalized differential vegetation index (NDVI), perpendicular drought index (PDI) extracted from SPOT-6 remote sensing images and potential solar radiation (PSR) extracted from SRTM. The interactions between topography and NDVI, PDI, and PSR were analyzed. The NDVI, PDI and PSR in June, July, August and September of 2016 and the SRTM were used as independent variables, and the UAV DEM was used as the dependent variable. Linear stepwise regression (LSR) and a back-propagation neural network (BPNN) were used to establish an elevation prediction model. The results indicated that (1) The correlation between topography and NDVI, PSR, PDI was significant at 0.01 level. The PDI and PSR improved the spatial resolution of SRTM data and reduce the vertical error. (2) The BPNN (R21 = 0.98, root mean square error, RMSE1 = 0.54) yielded a higher SRTM accuracy than did the studied linear model (RMSE1 = 1.00, R21 = 0.90). (3) A series of significant improvements in the SRTM were observed when assessed with the reference DEMs for two different areas, with RMSE reductions of 91% (from 14.95 m to 1.23 m) and 93% (from 15.6 m to 0.94 m). The proposed method improved the accuracy of existing DEMs and could provide support for accurate farmland management. [ABSTRACT FROM AUTHOR]

Metal-based additive manufacturing (AM) is a disruptive technique with great potential across multiple industries; however, its manufacturing quality is unstable, leading to an urgent requirement for component properties detection. The distribution of grain size has an important effect on many mechanical properties in AM, while the distribution of added elements, such as titanium (Ti), has a measurable effect on the grain size of an aluminum (Al) alloy. Therefore, the detection of the distributions of grain size and elements is of great significance for AM. In this study, we investigated the distribution of grain size and elements simultaneously for wire + arc additive manufacturing (WAAM) with an Al alloy using laser opto-ultrasonic dual (LOUD) detection. The average grain size obtained from the acoustic attenuation of ultrasonic signals was consistent with the results of electron backscatter diffraction (EBSD), with a coefficient of determination (R2) of 0.981 for linear fitting. The Ti element distribution obtained from optical spectra showed that the enrichment of Ti corresponded to the grain refinement area in the detected area. The X-ray diffraction (XRD) spectra showed that the spectral peaks were moved from Al to AlTi and Al2Ti forms in the Ti-rich areas, which confirmed the LOUD results. The results indicated that LOUD detection holds promise for becoming an effective method of analyzing the mechanical and chemical properties of components simultaneously, which could help explain the complex physical and chemical changes in AM and ultimately improve the manufacturing quality. [ABSTRACT FROM AUTHOR]

Compared to SnTe and PbTe base materials, the GeTe matrix exhibits a relatively high Seebeck coefficient and power factor but has garnered significant attention due to its poor thermal transport performance and environmental characteristics. As a typical p-type IV–VI group thermoelectric material, W-doped GeTe material can bring additional enhancement to thermoelectric performance. In this study, the introduction of W, Ge1−xWxTe (x = 0, 0.002, 0.005, 0.007, 0.01, 0.03) resulted in the presence of high-valence state atoms, providing additional charge carriers, thereby elevating the material's power factor to a maximum PFpeak of approximately 43 μW cm−1 K−2, while slightly optimizing the Seebeck coefficient of the solid solution. Moreover, W doping can induce defects and promote slight rhombohedral distortion in the crystal structure of GeTe, further reducing the lattice thermal conductivity κlat to as low as approximately 0.14 W m−1 K−1 (x = 0.002 at 673 K), optimizing it to approximately 85% compared to the GeTe matrix. This led to the formation of a p-type multicomponent composite thermoelectric material with ultra-low thermal conductivity. Ultimately, W doping achieves the comprehensive enhancement of the thermoelectric performance of GeTe base materials, with the peak ZT value of sample Ge0.995W0.005Te reaching approximately 0.99 at 673 K, and the average ZT optimized to 0.76 in the high-temperature range of 573–723 K, representing an increase of approximately 17% compared to pristine GeTe within the same temperature range. [ABSTRACT FROM AUTHOR]

A visible-light-mediated fluorosulfonylation reaction of thianthrenium salts has been developed to prepare various sulfonyl fluorides with 1,4-diazabicyclo [2.2.2] octane bis (sulfur dioxide) (DABSO) as sulfonyl source and cheap KHF2 as fluorine source based on radical sulfur dioxide insertion and fluorination strategy. This operationally simple protocol proceeds with high functional-group tolerance under mild reaction conditions. [ABSTRACT FROM AUTHOR]

Poor spectral stability and low detection accuracy have limited the development of laser-induced breakdown spectroscopy (LIBS) for use in liquid analysis. A simple and fast new liquid pretreatment method, named geometric constraint liquid-to-solid conversion (GCLSC), was used in sample pretreatment for LIBS to simultaneously improve the spectral stability and detection accuracy. An aluminum (Al) target was used as a substrate. Boron (B) and chromium (Cr) in aqueous solution were determined using LIBS with GCLSC. The results showed that the spectral stability and detection accuracy of LIBS in liquid analysis could be improved by using GCLSC when compared with using filter paper assisted liquid-to-solid conversion (FPLSC) and unconstrained direct liquid-to-solid conversion (UDLSC). The relative standard deviation (RSD) values of B and Cr from the GCLSC method were 6.8% and 4.6%, respectively. The root-mean-square error of cross validation (RMSECV) values of B and Cr for GCLSC were 2.09 mg L−1 and 1.63 mg L−1, respectively. The experimental results demonstrated that the GCLSC method is promising for improving the stability and accuracy of LIBS quantitative analysis in liquid detection. [ABSTRACT FROM AUTHOR]

Heavy metal particles in water are mainly derived from acidic industrial wastewater and seriously endanger the environment and public health. In this work, the pH effect on the detection of toxic metals in wastewater by laser-induced breakdown spectroscopy coupled with a phase transformation method (LIBS-PT) was investigated. Heavy metals of cadmium (Cd) and chromium (Cr) were selected as examples. The results showed that the presence of acids in wastewater inhibited the spectral enhancement of LIBS-PT on a metal substrate. This was mainly due to the presence of the salt floccule formed by the reaction of an acid with a metal substrate on the substrate surface. The floccule content increased as pH decreased, and the corresponding substrate ablation threshold increased. Therefore, more laser energy was used for ablation, resulting in reduced laser energy for ionization and reduced electron density. Eventually, spectral intensity decreased as electron density decreased. However, there was no significant change in plasma temperature. Meanwhile, the determination coefficients (R2) of Cd and Cr were all above 0.99 under the optimal pH 6.5 and on the optimal zinc (Zn) substrate. Limits of detection (LoDs) of 0.0089 mg L−1 and 0.0006 mg L−1 for Cd and Cr were obtained, respectively. The LoDs of Cd and Cr elements met the sewage discharge standard of China. The results indicated that the detection sensitivity of heavy metal elements in acidic wastewater can be significantly improved by optimizing the pH value of the solution using LIBS-PT. [ABSTRACT FROM AUTHOR]

As harmless alternative of antibiotics, two antimicrobial peptides (AMPs), including anti-lipopolysaccharide factor isoform 3 (ALFPm3) and cathelicidin (CATHPb1), were co-expressed in the common fish food Tetraselmis subcordiformis. Lysates from T.subcordiformis transformant were able to inhibit the bacterial growth of Staphylococcus aureus, Vibrio parahaemolyticus, and Vibrio splendidus. To test the effects of AMPs in vivo, turbot (Scophthalmusmaximus) underwent three dietary treatments, including commercial feeds (CON group), commercial feeds mixed with wild-type T.subcordiformis (WT group), and commercial feeds mixed with a mutant strain of T. subcordiformis (CSD group). Compared to CON group, both CSD and WT groups showed an increase in both the relative abundance and diversity of beneficial bacteria. The content of malondialdehyde was reduced and the enzymatic activities of lysozyme were increased in plasma. Comparisons of the biochemical factors in CSD group with those in CON group revealed that the relative abundance of Vibrio was decreased from 92.7% to 75.1%, and the number of bacteria containing the potentially pathogenic phenotypes was reduced. In the CSD group, the enzymatic activities of catalase and the expression levels of IgM, NKEF, IFNγ, MHC I, and IL-8R were higher compared to the WT group, whereas the levels of both TNFα and IL-1β were reduced. These results indicated that as an oral delivery vehicle for the AMPs, T.subcordiformis transformant improved the immunity, inflammatory response, and gut microbiome community of turbot. [ABSTRACT FROM AUTHOR]

• A comprehensive scheme for vision measurement under the refraction effect is studied. • A three-parameter calibration method for flat glass is developed. • A dynamic interval constraint for stereo matching in refraction images is proposed. • A new binocular disparity method used for refraction images is suggested. Vision measurement has become an indispensable technology in tunnel construction. However, the harsh construction environment necessitates the provision of a certain thickness of flat glass windows to protect the vision system. This, in turn, leads to an obvious refraction effect, rendering the pinhole model and traditional vision measurement methods inadequate. As such, this paper offers a comprehensive solution to this problem. Firstly, the imaging model under the refraction of flat glass is shown based on the virtual camera and virtual space point, respectively. Secondly, a three-parameter calibration method for flat glass was proposed, which could determine the refractive index, unit normal vector, and light path normal distance. A practical dynamic interval constraint was introduced to address the failure of the epipolar constraint in refraction image pairs. Lastly, a new binocular disparity method is presented to avoid the impact of refraction distortion on the solution accuracy of three-dimensional coordinates. Effectiveness experiments are conducted, showing a refractive index relative error within ±1%, a miniaturized and efficient dynamic interval constraint, a maximum reconstruction error of 0.120 mm, and a maximum measurement error of only 0.093 mm. A series of stability experiments are also performed under different target attitudes, glass attitudes, working distances, and pollution conditions. The results demonstrate the robustness of the proposed solution. Although the scheme is developed for the vision system in harsh tunnel construction environments, it can serve as a reference for any vision measurement applications under glass protection windows. [ABSTRACT FROM AUTHOR]

Correction for 'The pH effect on the detection of heavy metals in wastewater by laser-induced breakdown spectroscopy coupled with a phase transformation method' by Shixiang Ma et al., J. Anal. At. Spectrom., 2020, 35, 198–203, DOI: 10.1039/C9JA00349E. [ABSTRACT FROM AUTHOR]

BACKGROUND: Rice adulteration in the food industry that infringes on the interests of consumers is considered very serious. To realize the rapid and precise quantitation of adulterated rice, a visible near infrared (VNIR) hyperspectral imaging system (380–1000 nm) was developed in the present study. A Savitsky–Golay first derivative (SG1) transform was utilized to eliminate the constant spectral baseline offset. Then, the adulterated levels of rice samples were quantified by partial least squares regression (PLSR). RESULTS: A SG1‐PLSR model based on full‐wavelength was attained with a coefficient of determination of prediction set (RP) of 0.9909, root‐mean‐square error of prediction set (RMSEP) of 0.0447 g kg−1 and residual predictive deviation (RPDP) of 11.28. Furthermore, fifteen important wavelengths were selected based on the weighted regression coefficients (BW) and a simplified model (PLSR‐15) was established with RP of 0.9769, RMSEP of 0.0708 g kg−1 and RPDP of 3.49. Finally, two visualization maps produced by applying the optimal models (SG1‐PLSR and PLSR‐15) were used to visualize the adulterated levels of rice. CONCLUSION: These results demonstrate that VNIR hyperspectral imaging system is an effective tool for rapidly quantifying and visualizing the adulterated levels of rice. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Accurate and timely monitoring of flooded crop areas is crucial for disaster rescue and loss assessment. However, most flooded crop monitoring methods based on synthetic aperture radar (SAR) imagery were developed for rice, which is probably inappropriate for crops with complex canopy structures that strongly attenuate SAR signals. Additionally, these methods often rely on empirical thresholds and region-specific reference samples, limiting their reliability and applicability on a larger spatial scale. To address these issues, we developed a novel flooded crop mapping approach at a regional scale using Sentinel-1 time-series data and an unsupervised Gaussian Mixture Model (GMM). Our approach leverages a Flood Separability Index (FSI) derived from the fitted probability density function of flooded and non-flooded crop areas in a GMM. This allows us to overcome the limitations of manual input selection in previous studies. The multi-temporal GMM was constructed using the time-series images with optimal polarization to estimate the flooded crop extents on a regional scale. We also investigated the scattering mechanisms of three typical crop disaster structures within an agricultural landscape area. Our results indicate that the proposed multi-temporal GMM is robust in crop planting areas with complex canopy structures. The performance of both single-temporal and multi-temporal GMMs surpasses that of baseline methods such as Otsu and K-means. Compared with VV polarization, VH polarization exhibits greater potential for accurately mapping flooded crops in complex agricultural regions. Our approach does not require labeled samples or many predefined parameters, making it fast and feasible for mapping flooded crops with complex canopy structures in large spatial areas. • We developed an automatic approach to map flooded crop dynamics with GMM. • We analyzed the crop scattering mechanisms under complicated flooding situations. • We presented a novel Flooding Separability Index (FSI) based on GMM. • The VH polarization is potential to identify the flooded crops. [ABSTRACT FROM AUTHOR]

Highlights • DEX ameliorates early brain injury at 24 h after SAH. • DEX alleviates neuroinflammation, apoptosis, and BBB disruption after SAH. • DEX inhibits the activation of TLR4/NF-κB pathway and NLRP3 inflammasome after SAH. Abstract Early brain injury (EBI) plays a pivotal role in the prognosis of patients with subarachnoid haemorrhage (SAH). Dexmedetomidine (DEX), a highly selective α 2 receptor agonist, is reported to exert multiple protective effects in many neurological diseases. This study was designed to investigate whether DEX had neuroprotective functions in EBI after SAH, and to explore the possible mechanisms. The SAH model was established by an endovascular perforation in adult male Sprague-Dawley (SD) rats. DEX (25 µg/kg) or vehicle was administered intraperitoneally 2 h after SAH. Neurological deficits, brain oedema, inflammation, BBB damage, and cell apoptosis at 24 h after SAH were evaluated. Additionally, the expression of components of the Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) pathway, and the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome were also assessed. We demonstrated that DEX treatment improved neurological scores, alleviated brain oedema, reduced the permeability of the blood-brain barrier (BBB), and up-regulated the expression of tight junction proteins. DEX treatment could reduce the neutrophil infiltration, microglial activation, and pro-inflammatory factor release. In addition, DEX alleviated cell apoptosis at 24 h after SAH. Notably, DEX could also suppress the activation of the TLR4/NF-κB pathway and the NLRP3 inflammasome. These findings suggested that treatment with DEX after SAH attenuated SAH-induced EBI, partially through the suppression of the TLR4/NF-κB pathway and the NLRP3 inflammasome. [ABSTRACT FROM AUTHOR]

• LIBS assisted with laser-stimulated absorption (LSA-LIBS) was proposed to reduce self-absorption in the presence of spectral interference. • Rational selection of the excitation line was proved to be an important factor for self-absorption reduction. • The self-absorption factor of the Ni I 341.47 nm line was reduced by 85% using LSA-LIBS. Spectral interference and self-absorption seriously affect the accuracy of quantitative analysis in laser-induced breakdown spectroscopy (LIBS). In this work, we used LIBS assisted with laser-stimulated absorption (LSA-LIBS) to solve these problems. Taking nickel (Ni) in the alloy structural steel as an example, the results show that the spectral interference of Ni lines was eliminated, the self-absorption factor of the Ni I 341.47 nm line was reduced by 85%, and the average relative error for determination of Ni element was reduced by 83% using LSA-LIBS. The results indicate that spectral interference and self-absorption can be reduced simultaneously in LSA-LIBS. [ABSTRACT FROM AUTHOR]

Many studies have achieved efficient and accurate methods for identifying crop lodging under homogeneous field surroundings. However, under complex field conditions, such as diverse fertilization methods, different crop growth stages, and various sowing periods, the accuracy of lodging identification must be improved. Therefore, a maize plot featuring different growth stages was selected in this study to explore an applicable and accurate lodging extraction method. Based on the Akaike information criterion (AIC), we propose an effective and rapid feature screening method (AIC method) and compare its performance using indexed methods (i.e., variation coefficient and relative difference). Seven feature sets extracted from unmanned aerial vehicle (UAV) images of lodging and nonlodging maize were established using a canopy height model (CHM) and the multispectral imagery acquired from the UAV. In addition to accuracy parameters (i.e., Kappa coefficient and overall accuracy), the difference index (DI) was applied to search for the optimal window size of texture features. After screening all feature sets by applying the AIC method, binary logistic regression classification (BLRC), maximum likelihood classification (MLC), and random forest classification (RFC) were utilized to discriminate among lodging and nonlodging maize based on the selected features. The results revealed that the optimal window sizes of the gray-level cooccurrence matrix (GLCM) and the gray-level difference histogram statistical (GLDM) texture information were 17 × 17 and 21 × 21, respectively. The AIC method incorporating GLCM texture yielded satisfactory results, obtaining an average accuracy of 82.84% and an average Kappa value of 0.66 and outperforming the index screening method (59.64%, 0.19). Furthermore, the canopy structure feature (CSF) was more beneficial than other features for identifying maize lodging areas at the plot scale. Based on the AIC method, we achieved a positive maize lodging recognition result using the CSFs and BLRC. This study provides a highly robust and novel method for monitoring maize lodging in complicated plot environments. [ABSTRACT FROM AUTHOR]

The detection sensitivity of chlorine (Cl) and sulfur (S) elements is poor using direct laser-induced breakdown spectroscopy (LIBS) because of the high ionization energy of Cl and S. Therefore, a new technique, namely indirect laser-induced breakdown spectroscopy (ID-LIBS), was proposed to improve the detection sensitivity of Cl and S elements. The method detected Cl in water by indirectly detecting the excess silver (Ag) after the precipitation reaction of Ag and chloride. Similarly, the method indirectly detected S in water by detecting the excess barium (Ba) after the precipitation reaction of Ba and sulfate, due to Ag and Ba with low ionization energy and easy excitation. The lines of Ag I 546.5 nm and Ba I 553.5 nm were detected. The R2 values of 0.999 and 0.997 were obtained for Cl and S, respectively. The limit of quantitation (LoQ) was 2 mg/L for Cl and 5 mg/L for S. The detection sensitivity was improved by about three orders of magnitude compared to using Cl I 822.17 nm and S I 921.28 nm. The results showed that the technique of indirect LIBS can achieve the sensitive detection of Cl and S in water indicating that the technique has tremendous potential for element analysis of water. Image 1 • A rapid ID-LIBS method was proposed to sensitively and accurately detect Cl and S in water. • Ag and Ba were used as observational elements to indirectly analyze Cl and S in water, respectively. • Self-absorption effect in Ag and Ba detection was investigated. • The detection sensitivity could be improved by about three orders of magnitude using ID-LIBS. • This approach provides a potential method to improve the elemental detection sensitivity in solution in LIBS. [ABSTRACT FROM AUTHOR]

Remote sensing image data are often used as input in digital soil mapping (DSM). However, it is difficult to distinguish and identify soil types with less difference in reflectance spectral characteristics, because a small amount of input is not enough to provide enough common features. We consider that the hyper-temporal remote sensing data can be used to extract more common features of soil. The accuracy of DSM is improved by using the common features of soil or effective terrain attributes. We took Mingshui County of the Songnen Plain in northeast China as study area, which is known as a Black soil region. STRM DEM, legacy soil data, and 20 scenes Landsat images of bare soil period from 1984 to 2018 (April and May are considered a period of cultivated soil exposure in the study area), were used, with a maximum likelihood method classifier. A digital soil mapping model was constructed based on hyper-temporal data. Results from the study show that the accuracy of mapping with hyper-temporal classification characteristics, with an overall accuracy of 85.18% and a Kappa coefficient of 0.772, is higher than that of mono-temporal classification characteristics, with an average overall accuracy of 64.35% and an average Kappa coefficient of 0.467. After the introduction of relief degree of land surface (RDLS), the overall accuracy and Kappa coefficient of hyper-temporal mapping were 88.22% and 0.818, higher than the accuracy of other terrain factors. The research results signal the advantages of hyper-temporal remote sensing data in DSM, and the common features were able to improve the accuracy of DSM extracted from hyper-temporal data. This paper provided new insight to explain the impact of diverse terrain on DSM of Black soil region, and the mapping of soil type level could be accomplished more easily by the combination of the two characteristics. • Hyper-temporal remote sensing data are useful for DSM. • Use twenty scenes images and five terrain attributes to accomplish DSM • Use K–T transformation to compress and reduce dimension • RDLS and ELE are the key terrain attributes to distinguish soil types. • Hyper-temporal data can improve mapping accuracy and stability. [ABSTRACT FROM AUTHOR]

Background: Studies from Western countries reported a positive relationship between residential density (RD) and physical activity (PA) among adults. There was no such study from China, a rapidly-urbanizing country in the world. This study aimed to investigate the RD-PA association among urban adults in China.Methods: A multistage sampling approach was used to randomly select participants (aged 35-74 years old) in urban areas of Nanjing in 2017. The outcome variable was PA (dichotomized into "sufficient" or "insufficient"), while the independent variable was RD (tertiled into three sub-groups). Odds ratios (OR) and 95% confidence interval (CI) were computed to examine the RD-PA association using mixed-effects logistic regression models with adjustment for age, sex, nationality, marriage, educational attainment, employment status, body weight status, green space and neighborhood-level clustering effects.Results: Of the 1568 eligible participants, 1551 were interviewed (response rate = 98.9%), with the mean age (standard deviation) of 54.7 (11.1) years old, and 46% of men. After adjustment for potential confounders and community-level clustering effects, participants lived in communities with higher (OR = 0.31, 95% CI = 0.21, 0.47) and middle (OR = 0.70, 95% CI = 0.50, 0.99) residential density were significantly less likely to achieve sufficient physical activity relative to their counterparts lived in the lower densed communities. Similar negative RD-PA association was examined for men or women, separately. The difference in the ORs between the middle and higher RD tertiles was also statistically significant (P < 0.01).Conclusions: A negatively gradient RD-PA association, independent of body weight status and green space, was observed among urban adults in regional China. It has public health implications for China to help residents' promote and maintain physical activity through planning and constructing PA-/health-friendly built environment in future. [ABSTRACT FROM AUTHOR]

Background: Extracellular accumulation of amyloid β-peptide (Aβ) is one of pathological hallmarks of Alzheimer's disease (AD) and contributes to the neuronal loss. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an endoplasmic reticulum (ER) stress-inducible neurotrophic factor. Many groups, including ours, have proved that MANF rescues neuronal loss in several neurological disorders, such as Parkinson's disease and cerebral ischemia. However, whether MANF exerts its protective effect against Aβ neurotoxicity in AD remains unknown.Methods: In the present study, the characteristic expressions of MANF in Aβ1-42-treated neuronal cells as well as in the brains of APP/PS1 transgenic mice were analyzed by immunofluorescence staining, qPCR, and Western blot. The effects of MANF overexpression, MANF knockdown, or recombination human MANF protein (rhMANF) on neuron viability, apoptosis, and the expression of ER stress-related proteins following Aβ1-42 exposure were also investigated.Results: The results showed the increased expressions of MANF, as well as ER stress markers immunoglobulin-binding protein (BiP) and C/EBP homologous protein (CHOP), in the brains of the APP/PS1 transgenic mice and Aβ1-42-treated neuronal cells. MANF overexpression or rhMANF treatment partially protected against Aβ1-42-induced neuronal cell death, associated with marked decrease of cleaved caspase-3, whereas MANF knockdown with siRNA aggravated Aβ1-42 cytotoxicity including caspase-3 activation. Further study demonstrated that the expressions of BiP, ATF6, phosphorylated-IRE1, XBP1s, phosphorylated-eIF2α, ATF4, and CHOP were significantly downregulated by MANF overexpression or rhMANF treatment in neuronal cells following Aβ1-42 exposure, whereas knockdown of MANF has the opposite effect.Conclusions: These findings demonstrate that MANF may exert neuroprotective effects against Aβ-induced neurotoxicity through attenuating ER stress, suggesting that an applicability of MANF as a therapeutic candidate for AD. [ABSTRACT FROM AUTHOR]