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Deng X.,Central South University | Deng X.,Jiangxi University of Science and Technology | Deng X.,Key Laboratory of Medical Information Research | Chen Z.,Central South University | And 4 more authors.
Journal of Nanoscience and Nanotechnology

This paper proposes a new region-based tampering detection and recovering method that utilizes both reversible digital watermarking and quad-tree decomposition for medical diagnostic image's authentication. Firstly, the quad-tree decomposition is used to divide the original image into blocks with high homogeneity, and then we computer pixels' linear interpolation as each block's recovery feature. Secondly, these recovery features as the first layer watermarking information is embedded by using simple invertible integer transformation. In order to enhance the proposed method's security, the logistic chaotic map is exploited to choose each block's reference pixel. The second layer watermark comprises by the quad-tree information and essential parameters for extraction are embedded by LSB replacement. In the authentication phase, the embedded watermark is extracted and the source image is recovered, and the similar linear interpolation technique is utilized to get each block's feature. Therefore, the tampering detection and localization can be achieved through comparing the extracted feature with the recomputed one, and the extracted feature can be used to recover those tampered regions with high similarity to their original state. Experimental results show that, compared with previous similar existing scheme, the proposed method not only achieves high embedding capacity and good visual quality of marked and restored image, but also has more accuracy for tampering detection. Copyright © 2013 American Scientific Publishers All rights reserved. Source

Chen Z.,Central South University | Chen Z.,Key Laboratory of Medical Information Research | Deng X.,Central South University | Deng X.,Jiangxi University of Science and Technology | And 4 more authors.
Journal of Nanoscience and Nanotechnology

Nanoscience and Nanotechnology promotes the development of biomedical imaging devices, more and more valuable biomedical images are transmitted through the open network, and their copyright suffers a major challenge. This paper proposes a new lossless robust watermarking method to realize biomedical image's copyright protection. For high-resolution biomedical images, the redundant theory and histogram shifting method based on image block's difference are utilized to repeatedly embed copyright watermark into different color channels. In the extracting procedure, each layer's watermark information can be extracted from watermarked image respectively, and the final watermark is judged by the voting theory. The redundant scheme and voting theory guarantees the watermark can resist against random noise's attack well. Besides, in order to reduce the watermark overhead in embedding procedure, the histogram narrowing down technique is used to tackle with those image blocks would overflows and underflows. Experimental results showed that the proposed method outperformed the existing semi-fragile reversible watermarking scheme and provided a great robustness against moderate JPEG compression and salt-pepper and Gaussian noise. Copyright © 2013 American Scientific Publishers All rights reserved. Source

Guo H.,Central South University | Jin X.,Zhengzhou University | Zhu T.,Central South University | Wang T.,Central South University | And 25 more authors.
Journal of Medical Genetics

Background: High myopia, with the characteristic feature of refractive error, is one of the leading causes of blindness worldwide. It has a high heritability, but only a few causative genes have been identified and the pathogenesis is still unclear. Methods: We used whole genome linkage and exome sequencing to identify the causative mutation in a non-syndromic high myopia family. Direct Sanger sequencing was used to screen the candidate gene in additional sporadic cases or probands. Immunofluorescence was used to evaluate the expression pattern of the candidate gene in the whole process of eye development. Real-time quantitative PCR and immunoblot was used to investigate the functional consequence of the disease-associated mutations. Results: We identified a nonsense mutation (c.141C>G: p.Y47*) in SLC39A5 co-segregating with the phenotype in a non-syndromic severe high myopia family. The same nonsense mutation (c.141C>G:p.Y47*) was detected in a sporadic case and a missense mutation (c.911T>C:p. M304T) was identified and co-segregated in another family by screening additional cases. Both diseaseassociated mutations were not found in 1276 control individuals. SLC39A5 was abundantly expressed in the sclera and retina across different stages of eye development. Furthermore, we found that wild-type, but not disease-associated SLC39A5 inhibited the expression of Smadl, a key phosphate protein in the downstream of the BMP/TGF-β (bone morphogenic protein/transforming growth factor-β) pathway. Conclusions: Our study reveals that loss-of-function mutations of SLC39A5 are associated with the autosome dominant non-syndromic high myopia, and interference with the BMP/TGF-β pathway may be one of the molecular mechanisms for high myopia. Source

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