Hyperspectral anomaly detection is a widely used technique for exploring target of interest in hyperspectral images (HSIs). In recent years, the low-rank and sparse-decomposition-based anomaly ...detection model has attracted extensive attention. However, these models suffer from two main problems. First, it is difficult for them to completely separate the low-rank background and the sparse anomaly. Moreover, the extracted sparse component is inevitably contaminated by noise. Second, the incorporation of various constraints increases the cost of selecting the optimal parameters. To solve the two key problems, we propose a self-adaptive low-rank and sparse decomposition (SLaSD) method for hyperspectral anomaly detection in this article. The proposed method decomposes the sparse (anomaly) part of the HSI through a novel self-adaptive alternating direction method (S-ADM). The noise of the sparse part is suppressed through a dual strategy of integrating guided filter and the difference between the S-ADM-derived sparse features of pixels. The performance of the proposed method is evaluated by comparing with ten state-of-the-art methods using six real HSIs. It is shown that the proposed SLaSD method can produce more accurate detection results than the ten benchmark methods.
Past studies suggested that ginseng extracts and ginseng-derived molecules exerted significant regulatory effects on skin. However, no reports have described the effects of ginseng-derived ...nanoparticles (GDNPs) on skin cell proliferation and wound healing. In this study, we investigated whether GDNPs regulate the proliferation of skin cells and promote wound healing in a mouse model.
GDNPs were separated and purified via differential centrifugation and sucrose/D2O gradient ultracentrifugation. GDNP uptake, cell proliferation and cell cycle progression were measured by confocal microscopy, CCK-8 assay and flow cytometry, respectively. Cell migration and angiogenic effects were assessed by the wound scratch assay and tube formation assay, respectively. ELISA was used to detect extracellular matrix secretion. The relevant signaling pathway was confirmed by western blotting. The effects of GDNPs on skin wound healing were assessed by wound observation, HE staining, and western blotting.
GDNPs possessed the essential features of exosomes, and they were accumulated by skin cells. Treatment with GDNPs notably enhanced the proliferation of HaCaT, BJ and HUVECs. GDNPs also enhanced the migration in HaCaT cells and HUVECs and angiogenesis in HUVECs. GDNPs increased the secretion of MMP-1, fibronectin-1, elastin-1, and COL1A1 in all three cell lines. GDNPs regulated cell proliferation through the ERK and AKT/ mTOR pathways. Furthermore, GDNPs facilitated skin wound healing and decreased inflammation in a mouse skin wound model.
GDNPs can promote skin wound healing through the ERK and AKT/mTOR pathways. GDNPs thus represent an alternative treatment for chronic skin wounds.
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•Type II heterojunction materials with good piezoelectric response were prepared.•Bi-based composites showed rapid degradation of organic pollutants.•The piezoelectric catalytic ...mechanism and polarity matching principle were revealed.
Among numerous polluting compounds, the organic dyes and antibiotics are two servious factors causing water pollution. Hence, it is urgent to find a fast and safe way to degrade waste water in a sustainable approach. Here, ferroelectric heterostructure based on 2D Bi2MoO6 nanosheets and Bi2S3 nanorods has been prepared by a two-step solvothermal method for the reduction of organic dyes and antibiotics. Due to the energy band balance between Bi2S3 and Bi2MoO6, the formed type-II heterostructure can populate charge transfer at the junction and effectively inhibit electron-hole recombination. Under ultrasonic stimulation, catalytic active sites of a Bi2MoO6/Bi2S3 heterostructure for pollutant degradation can be generated through rapid charge transfer activation, thus enhancing the catalytic degradation effect of organic dyes and antibiotics. The Bi2MoO6/Bi2S3 heterostructure not only has good degradation effect, but also shows better stability. This work opens up new avenues for designing highly-efficient catalysts, which is of importance for wastewater degradation and energy-saving applications.
N-CQDs@W18O49 nanocomposites showed high activity in the photodegradation of ciprofloxacin (CIP) and methyl orange (MO). The excellent photocatalytic performance of N-CQDs@W18O49 was attributed to ...the promotion of charge separation by N-CQDs and the local surface plasmon resonance (LSPR) effect of W18O49 under full-spectrum light irradiation.
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Increasing the charge separation and the utilization efficiency of sunlight are essential factors in a photocatalytic process. In this study, we prepared crystalline N-CQDs@W18O49 heterostructures, through the in situ growth of W18O49 nanocrystals on nitrogen-doped carbon quantum dots (N-CQDs). N-CQDs@W18O49 nanocomposites showed high activity in the photodegradation of ciprofloxacin (CIP) and methyl orange (MO). The photodegradation activity of the optimized N-CQDs@W18O49-5 sample was four times higher than that of W18O49 under ultraviolet-visible (UV–vis) light irradiation. The photodegradation activity of N-CQDs@W18O49-5 sample was two times higher than that of W18O49 under near-infrared (NIR) light irradiation. The enhanced photosensitivity of the nanocomposites was attributed to the promotion of charge separation by N-CQDs and the local surface plasmon resonance (LSPR) effect of W18O49 under NIR light irradiation. This work provides a promising approach for designing and manufacturing photocatalysts with full-spectral responsiveness and improved charge separation.
The rapid and efficient acquisition of field-scale farmland soil profile moisture-distribution information is very important for achieving precise irrigation and the adjustment and deployment of ...irrigation strategies in farmland. EM38-MK2 is a portable, non-invasive device that induces electric currents in soil to generate secondary magnetic fields for the rapid measurement of apparent electrical conductivity in the field. In this study, cotton fields were used as experimental objects to obtain soil apparent conductivity data for three periods, which were combined with soil-moisture content data collected simultaneously from soil samples and measured in the laboratory to construct an apparent soil-profile moisture regression model. A simple kriging interpolation method was used to map the distribution of the irrigation volume in the field, considering only the highest irrigation volume in the field as the maximum water-holding capacity in the field. The results showed that EM38 could accurately detect the spatial variation of soil moisture in the field. The R2 of the linear fit between measured and predicted soil-water content ranged from 0.51 to 0.89; the RMSE ranged from 0.66 to 1.87; and the R2 and RPD of each soil-layer water content model of the single-period model were higher than those of the full-period model. By plotting the distribution of field irrigation, it could be seen that by comparing the predicted field irrigation with the actual irrigation, at least 160 m3 ha−1 of irrigation could be saved in all three periods at an irrigation depth of 40 cm, which is about 30% of the actual irrigation; at an irrigation depth of 60 cm, about 30% and 15% of irrigation could be reduced in July and August, respectively. There are three areas in the study area with high fixed-irrigation volumes located in the northwest corner, near 500 m in the northern half of the study area and 750 m east of the southern half of the study area. The results of this study proved that the use of EM38-MK2 to monitor and evaluate the soil-moisture content of the farmland at different periods can, to a certain extent, guide the irrigation amount needed to achieve efficient and precise irrigation in the field.
Cells sense various in vivo mechanical stimuli, which initiate downstream signaling to mechanical forces. While a body of evidences is presented on the impact of limited mechanical regulators in past ...decades, the mechanisms how biomechanical responses globally affect cell function need to be addressed. Complexity and diversity of in v/vo mechanical clues present dis- tinct patterns of shear flow, tensile stretch, or mechanical compression with various parametric combination of its magnitude, duration, or frequency. Thus, it is required to understand, from the viewpoint of mechanobiology, what mechanical features of cells are, why mechanical properties are different among distinct cell types, and how forces are transduced to down- stream biochemical signals. Meanwhile, those in vitro isolated mechanical stimuli are usually coupled together in vivo, suggesting that the different factors that are in effect individually could be canceled out or orchestrated with each other. Evidently, omics analysis, a powerful tool in the field of system biology, is advantageous to combine with mechanobiology and then to map the fullset of mechanically sensitive proteins and transcripts encoded by its genome. This new emerging field, namely mechanomics, makes it possible to elucidate the global responses under systematically-varied mechanical stimuli. This review discusses the current advances in the related fields of mechanomics and elaborates how cells sense external forces and activate the biological responses.
With great significance in military and civilian applications, subpixel target detection is of great interest in hyperspectral remote sensing. The subpixel targets usually also need to be unmixed to ...identify their components. Traditionally, these subpixel targets are first detected and then unmixed to obtain their corresponding abundances. Therefore, target detection and target unmixing are independently performed. However, there are potential relations between these two processes that need to be investigated. In this article, we integrate these two processes using iterative constrained sparse representation. The main idea of this algorithm is that each pixel can be linearly and sparsely represented by the prior target spectra and several background endmembers extracted from its neighborhood. Moreover, the sum-to-one and nonnegativity constraints are introduced to ensure the sparse representation coefficients to have physical meaning. Specifically, the background endmembers are automatically extracted from the local background based on an iterative process. Then, the test pixel is represented by these extracted endmembers. Finally, the detection output is determined by the total target abundance and the residuals. The main innovation of this method is that it implements detection and unmixing of subpixel target simultaneously, even if the local background is contaminated by target signals. Experiments conducted on both synthetic and real hyperspectral datasets demonstrate that the proposed detector achieves an outstanding performance on detection and unmixing.
Dry eye disease (DED) is one of the most prevalent ocular diseases in the world. In China, new lifestyles driven by information technology and the rapid ageing process have brought DED a severe ...public health concern. The aim of our study was to obtain the pooled prevalence of DED in China and explore its potential correlates.
A comprehensive systematic review was conducted to identify all relevant literature published since 1990. Meta-analysis and meta-regression approaches were adopted to estimate the prevalence of DED. The number of people with DED was obtained by multiplying the corresponding demographic data in 2010.
Advanced age, female sex and larger latitude were significant risk factors for DED by symptoms and signs, whereas only advanced age was positively associated with an increased prevalence of DED by symptoms. In 2010, the prevalence of DED by symptoms and signs were 13.55% (95% CI = 10.00-18.05) and that of DED by symptoms was 31.40% (95% CI = 23.02-41.13) in Chinese people aged 5-89 years, corresponding to a total of 170.09 million (95% CI = 125.52-226.63) and 394.13 million (95% CI = 288.99-516.30) affected individuals respectively.
The huge burden of DED in China calls for more public health attention and actions. Improved epidemiological studies on DED prevalence are still urgently needed.
The aim of this study was to identify the influence of specimen geometry and size on the results of aortic uniaxial tensile tests using custom-designed tissue cutters, clamps and molds. Six ...descending thoracic aortas from pigs were used for rectangular sample tests, in which the circumferential and axial specimens had widths of 6 mm, 8 mm and 10 mm. The other six aortas were used for the dog-bone-shaped sample tests and were punched into circumferential, axial and oblique specimens with widths of 2 mm, 4 mm and 6 mm. We performed uniaxial tensile tests on the specimens and compared the test results. The results showed that mid-sample failure occurred in 85.2% of the dog-bone-shaped specimens and in 11.1% of the rectangular samples, which could be caused by Saint-Venant's principle. Therefore, rectangular specimens were not suitable for aortic uniaxial tensile testing performed until rupture. The results also showed that the size effect of the aorta conformed to Weibull theory, and dog-bone-shaped specimens with a width of 4 mm were the optimal choice for aortic uniaxial tensile testing performed until rupture.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
► Three-year root zone soil water datasets in a large gully were used for analysis. ► Considerable soil moisture time stability existed in the large gully. ► Time-stale locations were showed ...temporally robust by cross validation. ► Spatial averages were reliably estimated by only a few randomly selected locations. ► A simple model was developed and well reproduced soil moisture time series.
Characterizing root-zone soil moisture patterns in large gullies is challenging as relevant datasets are scarce and difficult to collect. Therefore, we explored several statistical and modeling approaches, mainly focusing on time stability analysis, for estimating spatial soil moisture averages from point observations and precipitation time series, using 3-year root-zone (0–20, 20–40, 40–60 and 60–80cm) soil moisture datasets for a large gully in the Loess Plateau, China. We also developed a new metric, the root mean square error (RMSE) of estimated mean soil moisture, to identify time-stable locations. The time stability analysis revealed that different time-stable locations were identified at various depths. These locations were shown to be temporally robust, by cross-validation, and more likely to be located in ridges than in pipes or plane surfaces. However, we found that MRD (mean relative difference) operators, used to predict spatial soil moisture averages by applying a constant offset, could not be transferred across root zone layers for most time-stable locations. Random combination analysis revealed that at most four randomly selected locations were needed for accurate estimation of mean soil moisture time series. Finally, a simple empirical model was developed to predict root-zone soil moisture dynamics in large gullies from precipitation time series. The results showed that the model reproduced root-zone soil moisture well in dry seasons, whereas relatively large estimation error was observed during wet seasons. This implies that only precipitation observations might be not enough to accurately predict root-zone soil moisture dynamics in large gullies, and time series of soil moisture loss coefficient should be modeled and included.
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