92 research outputs found

    Accreted seamounts in North Tianshan, NW China: implications for the evolution of the Central Asian Orogenic Belt

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    The Carboniferous Bayingou ophiolitic mĂ©lange is exposed in North Tianshan accretionary complex in the southwestern part of the Central Asian Orogenic Belt (CAOB). The mĂ©lange is mainly composed of serpentinised ultramafic rocks (including harzburgite, lherzolite, pyroxenite, dunite and peridotite), pillowed and massive basalts, layered gabbros, radiolarian cherts, pelagic limestones, breccias and tuffs, and displays block-in-matrix structures. The blocks of ultramafic rocks, gabbros, basalts, cherts, and limestones are set in a matrix of serpentinised ultramafic rocks, massive basalts and tuffs. The basaltic rocks in the mĂ©lange show significant geochemical heterogeneity, and two compositional groups, one ocean island basalt-like, and the other mid-ocean ridge-like, can be distinguished on the basis of their isotopic compositions and immobile trace element contents (such as light rare earth element enrichment in the former, but depletion in the latter). The more-enriched basaltic rocks are interpreted as remnants/fragments of seamounts, derived from a deep mantle reservoir with low degrees (2–3%) of garnet lherzolite mantle melting. The depleted basalts most likely formed by melting of a shallower spinel lherzolite mantle source with ∌15% partial melting. It is probable that both groups owe their origin to melting of a mixture between plume and depleted MORB mantle. The results from this study, when integrated with previous work, indicate that the Junggar Ocean crust (comprising a significant number of seamounts) was likely to have been subducted southward beneath the Yili-Central Tianshan block in Late Devonian-Early Carboniferous. The seamounts were scraped-off and accreted along with the oceanic crust in an accretionary wedge to form the Bayingou ophiolitic mĂ©lange. We present a model for the tectonomagmatic evolution of this portion of the CAOB involving prolonged intra-oceanic subduction with seamount accretion

    Cloud Extraction from Chinese High Resolution Satellite Imagery by Probabilistic Latent Semantic Analysis and Object-Based Machine Learning

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    Automatic cloud extraction from satellite imagery is a vital process for many applications in optical remote sensing since clouds can locally obscure the surface features and alter the reflectance. Clouds can be easily distinguished by the human eyes in satellite imagery via remarkable regional characteristics, but finding a way to automatically detect various kinds of clouds by computer programs to speed up the processing efficiency remains a challenge. This paper introduces a new cloud detection method based on probabilistic latent semantic analysis (PLSA) and object-based machine learning. The method begins by segmenting satellite images into superpixels by Simple Linear Iterative Clustering (SLIC) algorithm while also extracting the spectral, texture, frequency and line segment features. Then, the implicit information in each superpixel is extracted from the feature histogram through the PLSA model by which the descriptor of each superpixel can be computed to form a feature vector for classification. Thereafter, the cloud mask is extracted by optimal thresholding and applying the Support Vector Machine (SVM) algorithm at the superpixel level. The GrabCut algorithm is then applied to extract more accurate cloud regions at the pixel level by assuming the cloud mask as the prior knowledge. When compared to different cloud detection methods in the literature, the overall accuracy of the proposed cloud detection method was up to 90 percent for ZY-3 and GF-1 images, which is about a 6.8 percent improvement over the traditional spectral-based methods. The experimental results show that the proposed method can automatically and accurately detect clouds using the multispectral information of the available four bands

    Autophagy in Atherosclerosis: A Phenomenon Found in Human Carotid Atherosclerotic Plaques

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    Background: Autophagy has been found to be involved in animal and cell models of atherosclerosis, but to date, it lacks general observation in human atherosclerotic plaques. Here, we investigated autophagy in smooth muscle cells (SMCs), endothelial cells (ECs), and macrophages in human atherosclerotic plaques via transmission electron microscopy (TEM), western blotting, and immunohistochemistry analysis. Methods: The histopathologic morphology of these plaques was observed via hematoxylin and eosin staining. The ultrastructural morphology of the SMCs, ECs, and macrophages in these plaques was observed via TEM. The localization of microtubule-associated protein 1 light chain 3 (MAP1-LC3), a relatively special maker of autophagy, in plaques was observed by double fluorescent immunochemistry and western blotting. Results: All of these human atherosclerotic plaques were considered advanced and unstable in histologically observation. By double fluorescent immunochemistry, the expression of LC3-II increased in the SMCs of the fibrous cap, the macrophages, and the microvascular ECs of the plaque shoulders. The protein level of LC3-II by western blotting significantly increased in plaques compared with normal controls. In addition, TEM observation of plaques revealed certain features of autophagy in SMCs, ECs, and macrophages including the formation of myelin figures, vacuolization, and the accumulation of inclusions in the cytosol. These results indicate that autophagy is activated in SMCs, ECs, and macrophages in human advanced atherosclerotic plaques. Conclusions: Our study is to demonstrate the existence of autophagy in human atherosclerotic plaques by different methods, which may contribute to the development of pharmacological approaches to stabilize vulnerable and rupture-prone lesions

    Automatic Cloud Detection for Chinese High Resolution Remote Sensing Satellite Imagery

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    Cloud detection is always an arduous problem in satellite imagery processing, especially the thin cloud which has the similar spectral characteristics as ground surfacehas long been the obstacle of the production of imagery product. In this paper, an automatic cloud detection method for Chinese high resolution remote sensing satellite imagery is introduced to overcome this problem.Firstly, the image is transformed from RGB to HIS color space by an improved color transformation model. The basic cloud coverage figure is obtained by using the information of intensity and saturation,followed by getting the modified figure with the information of near-infrared band and hue. Methods of histogram equalization and bilateral filtering, combined with conditioned Otsu thresholding are adopted to generate texture information. Then the cloud seed figureis obtained by using texture information to eliminate the existed errors in the modified figure. Finally, cloud covered areas are accurately extracted by integration of intensity information from the HIS color space and cloud seed figure. Compared to the detection results of other automatic and interactive methods, the overall accuracy of our proposed method achieves nearly 10% improvement, and it is capable of improving the efficiency of cloud detection significantly

    LncRNA NR2F2-AS1 functions as a tumor suppressor in gastric cancer through targeting miR-320b/PDCD4 pathway

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    Gastric cancer is among the most frequently occurring gastrointestinal malignancies with a high mortality rate worldwide. Long non-coding RNAs (lncRNAs) are defined as core regulators in the occurrence and progression of multiple cancers, including gastric carcinoma. Mounting evidence has indicated that NR2F2-AS1 can inhibit several malignant tumors. However, the function and potential mechanism of NR2F2-AS1 remain unclear. In the current study, we found that NR2F2-AS1 was weakly expressed in gastric cancer cells in comparison with normal cells. The study has further disclosed that ectopic of NR2F2-AS1 repressed cell proliferation, migration, invasion and EMT whereas it promoted cell apoptosis in gastric carcinoma. Subsequently, our results confirmed that miR-320b was negatively regulated and that suppression of miR-320b alleviated the malignant behaviors of GC cells. More importantly, PDCD4 was a target of miR320b. Mechanistically, NR2F2-AS1 modulated the expression level of PDCD4 by sponging miR-320b. Finally, rescue assays demonstrated that NR2F2-AS1 down-regulated PDCD4 expression to restrain the development of gastric cancer by competitively binding to miR-320b. On the whole, our study revealed the role of NR2F2-AS1/miR-320b/PDCD4 regulatory network in gastric cancer, suggesting NR2F2-AS1 may represent a novel therapeutic target for patients with gastric carcinoma

    A Novel Security Scheme Based on Instant Encrypted Transmission for Internet of Things

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    Internet of Things (IoT) is a research field that has been continuously developed and innovated in recent years and is also an important driving force for the improvement of people’s life in the future. There are lots of scenarios in IoT where we need to collaborate through devices to complete tasks; that is, a device sends data to other devices, and other devices operate on the aid of the data. These transmitted data are often users’ privacy data, such as medical data and grid data. We propose an instant encrypted transmission based security scheme for such scenarios in IoT. The analysis in this paper indicates that our scheme can guarantee the security of users’ data while ensuring rapid transmission and acquisition of instant IoT data

    Sinhronizacija in stabilnost treh sovrtečih se rotorjev, povezanih z vzmetmi v neresonančni sistem

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    With the rapid development of horizontal drilling technology, the drilling fluid shale shaker (DFSS) features high capacity and high efficiency. Hence, a vibrating mechanism of a three co-rotating rotor system coupled with springs is proposed for designing large-sized and heavy-duty vibrating screens in petroleum drilling engineering. To master synchronization of the vibrating system, the dynamic equations of three co-rotating rotors coupled with springs are first developed based on Lagrange’s equations. Second, synchronous conditions of the system are derived based on the average method, and its stability criterion is obtained by adopting Hamilton’s principle. Furthermore, the influences of various factors, including positional parameters of three motors, stiffness coefficient of the springs and frequency ratio on synchronization behaviour, are numerically analysed in the steady state. Additionally, the Runge–Kutta algorithm with adaptive control is employed to build an electromagnetic coupling model, and the relationships between the synchronization state of the system and its mechanical-electrical coupling characteristics are investigated. Finally, an experimental prototype is designed to validate the theory and numerical analysis. The research result shows that the in-phase synchronization of three co-rotating rotors coupled with springs is easy to implement with the selection of a sufficiently large stiffness

    Improvement in Noodle Quality and Changes in Microstructure and Disulfide Bond Content through the Addition of Pepper Straw Ash Leachate

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    Every year, a significant amount of pepper stalks are wasted due to low utilization. The ash produced from pepper stalks contains a significant amount of alkaline salts, which are food additives that can enhance the quality of noodles. Therefore, utilizing natural pepper straw ash to improve the quality of noodles shows promising development prospects. In this study, pepper straw ash leachate (PSAL) was extracted and added to noodles. The quality of the noodles gradually improved with the addition of PSAL, with the best effect observed at a concentration of 18% (PSAL mass/flour mass). This addition resulted in a 57.8% increase in noodle hardness, a 55.43% increase in chewiness, a 19.41% rise in water absorption rate, and a 13.28% increase in disulfide bond content. These alterations rendered the noodles more resilient during cooking, reducing their tendency to soften and thus enhancing chewiness and palatability. Incorporating PSAL also reduced cooking loss by 57.79%. Free sulfhydryl groups decreased by 5.1%, and scanning electron microscopy revealed a denser gluten network structure in the noodles, with more complete starch wrapping. This study significantly enhanced noodle quality and provided a new pathway for the application of pepper straw resources in the food industry

    Quality Improvement of Zao Pepper by Inoculation with <i>Lactobacillus plantarum</i> 5-1: Probiotic Ability and Fermentation Characteristics of Lactic Acid Bacteria

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    Zao pepper is a fermented type with a distinct flavor, and Zao pepper-based dishes are popular. However, in spontaneous fermentation (SF), the adverse microorganisms of Zao pepper are uncontrollable and alter the product quality. Lactic acid bacteria (LAB) inhibit the growth of harmful bacteria and endow a sour taste in SF. Therefore, the purpose of this study was to isolate autochthonic LAB from SF and through inoculated fermentation (IF) to improve Zao pepper quality. Four LAB strains were selected for probiotic experiments by sensory evaluation based on the flavor of Zao pepper in vitro. Intriguingly, Lactobacillus plantarum 5-1 showed superior safety and probiotics, with the fastest growth and acid-production rate. Moreover, the nitrite reductase viability of L. plantarum 5-1 reached 4.73 Όmol/mL·h. The use of IF via L. plantarum 5-1 increased the total acid content 2-fold and reduced the nitrite content by 0.36-fold compared to SF in Zao pepper. In addition, IF improved the color and texture of Zao pepper. These results indicate that the autochthonic L. plantarum 5-1 improved the quality of Zao pepper, providing a new strategy for enhancing the stability of fermented pepper

    CD13-Mediated Pegylated Carboxymethyl Chitosan-Capped Mesoporous Silica Nanoparticles for Enhancing the Therapeutic Efficacy of Hepatocellular Carcinoma

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    Liver cancer, especially hepatocellular carcinoma, is an important cause of cancer-related death, and its incidence is increasing worldwide. Nano drug delivery systems have shown great promise in the treatment of cancers. In order to improve their therapeutic efficacy, it is very important to realize the high accumulation and effective release of drugs at the tumor site. In this manuscript, using doxorubicin (DOX) as a model drug, CD13-targeted mesoporous silica nanoparticles coated with NGR-peptide-modified pegylated carboxymethyl chitosan were constructed (DOX/MSN-CPN). DOX/MSN-CPN comprises a spherical shape with an obvious capping structure and a particle size of 125.01 ± 1.52 nm. With a decrease in pH, DOX/MSN-CPN showed responsive desorption from DOX/MSN-CPN and pH-responsive release of DOX was observed. Meanwhile, DOX/MSN-CPN could be efficiently absorbed through NGR-mediated internalization in vitro and could efficiently deliver DOX to tumor tissues with long accumulation times in vivo, suggesting good active targeting properties. Moreover, significant tumor inhibition has been observed in antitumor studies in vivo. This study provides a strategy of utilizing DOX/MSN-CPN as a nano-platform for drug delivery, which has superb therapeutic efficacy and safety for the treatment of hepatocellular carcinoma both in vivo and in vitro
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