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With the development of remote sensing technology and imaging spectrometer, the resolution of hyperspectral remote sensing image has been continually improved, its vast amount of data not only improves the ability of the remote sensing detection but also brings great difficulties for analyzing and processing at the same time. Band selection of hyperspectral imagery can effectively reduce data redundancy and improve classification accuracy and efficiency. So how to select the optimum band combination from hundreds of bands of hyperspectral images is a key issue. In order to solve these problems, we use spectral clustering algorithm based on graph theory. Firstly, taking of the original hyperspectral image bands as data points to be clustered , mutual information between every two bands is calculated to generate the similarity matrix. Then according to the graph partition theory, spectral decomposition of the non-normalized Laplacian matrix generated by the similarity matrix is used to get the clusters, which the similarity between is small and the similarity within is large. In order to achieve the purpose of dimensionality reduction, the inter-class separability factor of feature types on each band is calculated, which is as the reference index to choose the representative bands in the clusters furthermore. Finally, the support vector machine and minimum distance classification methods are employed to classify the hyperspectral image after band selection. The method in this paper is different from the traditional unsupervised clustering method, we employ spectral clustering algorithm based on graph theory and compute the interclass separability factor based on a priori knowledge to select bands. Comparing with traditional adaptive band selection algorithm and band index based on automatically subspace divided algorithm, the two sets of experiments results show that the overall accuracy of SVM is about 94. 08% and 94. 24% and the overall accuracy of MDC is about 87. 98% and 89. 09%, when the band selection achieves a relatively optimal number of clusters using the method propoesd in this paper. It effectively remains spectral information and improves the classification accuracy.
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As the rotation speed of ground based hyperspectral imaging system is too fast in the image collection process, which exceeds the speed limitation, there is data missed in the rectified image, it shows as the_black lines. At the same time, there is serious distortion in the collected raw images, which effects the feature information classification and identification. To solve these problems, in this paper, we introduce the each component of the ground based hyperspectral imaging system at first, and give the general process of data collection. The rotation speed is controlled in data collection process, according to the image cover area of each frame and the image collection speed of the ground based hyperspectral imaging system, And then the spatial orientation model is deduced in detail combining with the star scanning angle, stop scanning angle and the minimum distance between the sensor and the scanned object etc. The oriented image is divided into grids and resampled with new spectral. The general flow of distortion image corrected is presented in this paper. Since the image spatial resolution is different between the adjacent frames, and in order to keep the highest image resolution of corrected image, the minimum ground sampling distance is employed as the grid unit to divide the geo-referenced image. Taking the spectral distortion into account caused by direct sampling method when the new uniform grids and the old uneven grids are superimposed to take the pixel value, the precise spectral sampling method based on the position distribution is proposed. The distortion image collected in Lao Si Cheng ruin which is in the Zhang Jiajie town Hunan province is corrected through the algorithm proposed on above. The features keep the original geometric characteristics. It verifies the validity of the algorithm. And we extract the spectral of different features to compute the correlation coefficient. The results show that the improved spectral sampling method is better than the direct sampling method. It provides the reference for the similar product used on the ground.
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In order to correct the image distortion in the hyperspectral camera side-scan geometric Imaging, the image pixel geo-referenced algorithm was deduced in detail in the present paper, which is suitable to the linear push-broom camera side-scan imaging on the ground in any direction. It takes the orientation of objects in the navigation coordinates system into account. Combined with the ground sampling distance of geo-referenced image and the area of push broom imaging, the general process of geo-referenced image divided into grids is also presented. The new image rows and columns will be got through the geo-referenced image area dividing the ground sampling distance. Considering the error produced by round rule in the pixel grids generated progress, and the spectral mixing problem caused by traditional direct spectral sampling method in the process of image correction, the improved spectral sampling method based on the weighted fusion method was proposed. It takes the area proportion of adjacent pixels in the new generated pixel as coefficient and then the coefficients are normalized to avoid the spectral overflow. So the new generated pixel is combined with the geo-referenced adjacent pixels spectral. Finally the amounts of push-broom imaging experiments were taken on the ground, and the distortion images were corrected according to the algorithm proposed above. The results show that the linear image distortion correction algorithm is valid and robust. At the same time, multiple samples were selected in the corrected images to verify the spectral data. The results indicate that the improved spectral sampling method is better than the direct spectral sampling algorithm. It provides reference for the application of similar productions on the ground.
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Aiming at the spectral distortion produced in PCA fusion process, the present paper proposes an improved low spectral distortion PCA fusion method. This method uses NCUT (normalized cut) image segmentation algorithm to make a complex hyperspectral remote sensing image into multiple sub-images for increasing the separability of samples, which can weaken the spectral distortions of traditional PCA fusion; Pixels similarity weighting matrix and masks were produced by using graph theory and clustering theory. These masks are used to cut the hyperspectral image and high-resolution image into some sub-region objects. All corresponding sub-region objects between the hyperspectral image and high-resolution image are fused by using PCA method, and all sub-regional integration results are spliced together to produce a new image. In the experiment, Hyperion hyperspectral data and Rapid Eye data were used. And the experiment result shows that the proposed method has the same ability to enhance spatial resolution and greater ability to improve spectral fidelity performance.
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Yungang Grottoes were built in the mid-5th century A. D., and named as a UNESCO World Heritage site in 2001. Most of the grottoes were built on the feldspathic quartz sandstones. They were seriously damaged due to the environmental impact. The main form of the weathering is the powdered weathering. The weathering conditions are generally characterized by electrical sounding, penetration resistance, molecular spectroscopy, etc. However, although these methods can give good results about the weathering conditions for a specified sample or site, they are not suitable for providing a global profile of the weathering conditions. The present paper provides a method for effectively and roundly assessing the overall powdered weathering conditions of the Yungang Grottoes based on hyperspectral imaging. Powdered weathering could change the structure and granularity of the sandstone, and thus change the spectral reflectance of the sandstone surface. Based on the hyperspectral data collected from 400 nm to 1 000 nm and normalized by log residuals method, the powdered weathering conditions of the sandstones were classified into strong weathering and weak weathering. The weathering profile was also mapped in the Envi platform. The mapping images were verified using the measured hyperspectal data of the columns in front of the 9th and 10th grottoes as the examples. The mapping images were substantially fitted to the real observations, showing that hyperspectral imaging can be used to estimate the overall powdered weathering of the sandstones.
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For the past several decades, only a few studies were conducted on the change in immature rice liposomes during seed development. To evaluate and compare the lipid material of different degrees of developing rice grains, this paper focused on fresh rice seeds from only one most popular species of Dasan divided into five growth periods. The lipid components of fresh rice, especially γ-oryzanol and fatty acids equipped with extremely beneficial phytonutrients, were investigated. The results illustrated that the level of extracted liposome increased gradually along with the development of rice and in the third stage of development, the level of liposome achieved maximum. And then, instead of increasing, it was decreased at later stages of development. Moreover, the antioxidant activity of fresh edible rice (FER) was also evaluated by DPPH and ABTS assay. It was shown that FER has the higher antioxidant activity than the ripened rice seed on lipids, which will improve FER using on the functional foods and help provide certainly theoretical basis in food processing industry.
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Antioxidantes/metabolismo , Lipossomos/metabolismo , Oryza/metabolismo , Sementes/crescimento & desenvolvimento , Ácidos Graxos/metabolismo , Metabolismo dos Lipídeos , Oryza/crescimento & desenvolvimento , Fenilpropionatos/metabolismo , Sementes/metabolismoRESUMO
Cathepsin S plays an important role in the pathogenesis of several cardiovascular diseases; however, the relationship between serum cathepsin S and cerebral infarction (CI) is still unknown. This study aimed to investigate the relationship between acute phase serum cathepsin S level and cerebral infarction. A total of 202 stroke patients were enrolled into this study, and were divided into cerebral infarction (n = 140) group and non-cerebral infarction group (non-CI, n = 62). Fifty healthy individuals were recruited as the control group. Serum levels of cathepsin S and cystatin C were measured at days 1, 7, and 14 posthospitalization. Compared to the non-CI group, the CI group had significantly higher rates of hypertension, dyslipidemia, and smoking (all P < 0.05). The CI group had significantly higher cathepsin S levels and cathepsin S to cystatin C ratio (CatS/CysC) at both days 1 and 7 posthospitalization (both P < 0.05). Multivariate logistic regression analysis demonstrated that cathepsin S level (day 7) and CatS/CysC (days 1 and 7) were the associated factors with CI (all P < 0.05). Receiver operating characteristic (ROC) curve analysis revealed that the Area Under Curve (AUC) value of CatS-day7, CatS/CysC-day1, and CatS/CysC-day7 were 0.726 (95% CI: 0.652-0.800, P < 0.001), 0.641 (95% CI: 0.559-0.723, P = 0.001), and 0.721 (95% CI: 0.645-0.797, P = 0.039), respectively. Cathepsin S and CatS/CysC were associated with acute CI, and may have the potential to be the diagnostic biomarkers for CI. Our findings help to better understand the role of serum cathepsin S level in CI.
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Proteínas de Fase Aguda/metabolismo , Catepsinas/sangue , Infarto Cerebral/sangue , Cistatina C/sangue , Idoso , Infarto Cerebral/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROCRESUMO
OBJECTIVE: To investigate the expression and the subcellular localization of HDAC9 in different brain regions of mice after cerebral ischemic injury and explore the association between HDAC9 and ischemic stroke. METHODS: Twenty-one male C57BL/6 mice were randomly divided into sham-operated group (n=9) and operated group (n=12). In the latter group, the mice with Zea-Longa neurological deficit scores of 2 or 3 following middle cerebral artery occlusion (MCAO) were assigned into MCAO group (n=9). Immunofluorescence was performed to investigate the subcellular localization of HDAC9 in the brain tissues on day 3 after MCAO. Western blotting and qRT-PCR were used to analyze the expression of HDAC9 in different regions of the brain. Results Immunofluorescence showed more intense HDAC9 expressions in the brain tissues around the infarct focus, and in the cells surrounding the infarct, HDAC9 expression was obviously increased in the cytoplasm and reduced in the cell nuclei. Compared with the other brain regions, the ipsilesional cortex with MCAO showed more abundant HDAC9 expressions at both the mRNA and protein levels (P<0.05). CONCLUSION: HDAC9 may be closely related to cerebral ischemic injury and participate in the pathophysiological process of ischemic stroke.
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Isquemia Encefálica/metabolismo , Encéfalo/metabolismo , Histona Desacetilases/metabolismo , Proteínas Repressoras/metabolismo , Acidente Vascular Cerebral/metabolismo , Animais , Modelos Animais de Doenças , Infarto da Artéria Cerebral Média , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
The aim of this study is to explore the therapeutic potential of RYGB, a common used bariatric surgery, on diabetic polyneuropathy (DPN) in streptozotocin (STZ)-induced diabetic rats. In animal model experiments, rats were made diabetic by STZ administration, and after 12 weeks of diabetes, two groups were studied: RYGB and sham surgery control (PF). Change in oral glucose tolerance, insulin sensitivity, and the plasma concentrations of insulin, glucagon, glucagon-like peptide-1 (GLP-1) were measured. Peripheral nerve function was determined by the current perception threshold. Sciatic nerve blood flow (SNBF) and intraepidermal nerve fiber densities (IENFDs) also were evaluated. The results indicated that glucose tolerance and insulin sensitivity were significantly improved in the RYGB group. Fasting total GLP-1 were increased in the RYGB group. The increase seen in current perception threshold vales in RYGB group was reduced. The decreased IENFDs in sole skins of RYGB group were ameliorated by RYGB. In conclusion, the findings indicate that RYGB ameliorates the severity of DPN, which may be associated with increased GLP-1 and improved insulin sensitivity/action.
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OBJECTIVE: To observe the expression of Na(v)1.1 and Na(v)1.6 after the electroacupuncture therapy (ET) on acute cerebral ischemia, and discuss the mechanism of function of ET. METHODS: Focal acute cerebral ischemia model was established by the occlusion of right middle cerebral artery. Rats were randomly divided into sham operation control (SC), ischemia control (IC) and ET groups. Four acupoints, 'NEIGUAN', 'WAIGUAN', 'SANYINJIAO', and 'ZUSANLI', were selected to be acupunctured. Immunofluorescence and real-time PCR methods were used to detect Na(v)1.1 and Na(v)1.6 expression, and 2,3,5-triphenyl tetra-zolium chloride staining was used to detect infarct volume at 6 hours, 1, 2, 3, and 7 days after ischemia. RESULTS: There is no change in the expression of Na(v)1.1 and Na(v)1.6 in SC group. After ischemia the expression of Na(v)1.1 and Na(v)1.6 was up-regulated compared with that of SC group. The Na(v)1.1 expression was down-regulated from 6 hours to 2 days, then up-regulated from 3 to 7 days. The Na(v)1.6 expression was up-regulated from 6 hours to 1 day, then down-regulated from 2 to 7 days after ischemia. In ET group the neurological deficit behavior, the change in Na(v)1.1 and Na(v)1.6 expression, and the infarct volume were more dramatic than those in IC group at the same time point, and the difference had a statistic value (P<0.05). CONCLUSION: Na(v)1.1 and Na(v)1.6 play a role in the injury of cerebral ischemia, ET could regulate the expression of Na(v)1.1 and Na(v)1.6 after ischemia, reduce the infarction volume and decrease cerebral ischemic damage. ET had a cerebral protective function, and one of its important mechanism may be it could regulate the expression of Na(v)1.1 and Na(v)1.6 after ischemia.
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Infarto Encefálico/metabolismo , Infarto Encefálico/terapia , Isquemia Encefálica/metabolismo , Isquemia Encefálica/terapia , Eletroacupuntura/métodos , Proteínas do Tecido Nervoso/biossíntese , Canais de Sódio/biossíntese , Animais , Infarto Encefálico/fisiopatologia , Isquemia Encefálica/fisiopatologia , Modelos Animais de Doenças , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/fisiopatologia , Infarto da Artéria Cerebral Média/terapia , Masculino , Canal de Sódio Disparado por Voltagem NAV1.1 , Canal de Sódio Disparado por Voltagem NAV1.6 , Proteínas do Tecido Nervoso/genética , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Canais de Sódio/genéticaRESUMO
OBJECTIVE: To observe the expression of Nav1.1 and the effect of electroacupuncture therapy (ET) on it after acute cerebral ischemia. METHODS: Focal acute cerebral ischemic model was established by occluding right middle cerebral artery. One hundred and forty-five male adult Sprague-Dawley rats were randomly divided into four groups: sham operation group, middle cerebral artery occlusion (MCAO) group, ET group and riluzole group. Double immunofluorescence and real-time PCR were used to observe Nav1.1 expression, and TTC staining was used to detect infarct volume at 6 hours, 1 day, 2 days, 3 days and 7 days after ischemia. RESULTS: The expression of Nav1.1 in sham operation group had no change. After ischemia, the expression of Nav1.1 was up-regulated evidently at 6 hours compared with sham operation group, down-regulated at 1 day and up-regulated again from 2 to 7 days after ischemia; the expression at 7 days was lower than that at 6 hours. In ET group and riluzole group, Nav1.1 expression were down-regulated compared with that in MCAO group after ischemia, the infarct volume was smaller than that in MCAO group at the same time point, and the difference is significant (p<0.05); however, the difference between ET group and riluzole group is not significant (p>0.05). CONCLUSION: ET and riluzole could regulate the expression of Nav1.1 after ischemia, decrease the infarction volume and reduce cerebral ischemic injury. One of the important mechanisms for ET's cerebral protective function may be that it could regulate the expression of Nav1.1 after ischemia.
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Encéfalo/metabolismo , Eletroacupuntura , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/terapia , Proteínas do Tecido Nervoso/metabolismo , Canais de Sódio/metabolismo , Análise de Variância , Animais , Imunofluorescência , Infarto da Artéria Cerebral Média/genética , Masculino , Canal de Sódio Disparado por Voltagem NAV1.1 , Proteínas do Tecido Nervoso/genética , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Riluzol/farmacologia , Riluzol/uso terapêutico , Canais de Sódio/genéticaRESUMO
OBJECTIVE: To explore the effect of leukoaraiosis on conscious disturbance in patients with acute cerebral infarction. METHODS: A follow-up study including 138 patients with acute cerebral infarction matched with the diagnostic criteria of the Forth Cerebrovascular Disease Conference, were carried out. Patients were divided into two groups, using MRI to estimate the white substance process around cerebral ventricle, including 78 of them with leukoaraiosis and 60 without leukoaraiosis were followed up using Glasgow coma scale scores and England OCSP classification in 1 month, 3 month and 6 month after onset. RESULTS: The independent factors of conscious disturbance included leukoaraiosis (OR = 5.294, 95% CI: 1.451-19.318), and OCSP classification (TACI and POCI especially) (OR = 14.489, 95% CI: 4.121-50.934). At the initial, the first month and the third month of the stroke episodes, significant difference (P < 0.05) was noticed when using Glasgow coma scales, and the scales in leukoaraiosis group was lower than the control. CONCLUSION: TACI and POCI in OCSP classification were independent risk factors of conscious disturbance, and leukoaraiosis was also the independent factor. The incidence of conscious disturbance after stroke in patients with leukoaraiosis were lower than in that without leukoaraiosis. On the other hand, the degree of conscious disturbance was more serious and slower than those without leukoaraiosis, suggesting that the effect of leukoaraiosis was duplicate for conscious disturbance. Because patients with leukoraiosis had tolerance of chronic cerebral ischemia. The number of patients with conscious disturbance after stroke was fewer relatively. Leukoaraiosis had inactive effect for amelioration of conscious disturbance after three months of the episode. The grouping of OCSP played a primary while leukoaraiosis playing a secondary role, despite the patients with or without conscious disturbance after stroke.