Image quality assessment based on the perceived structural similarity index of an image.

Image quality assessment (IQA) has a very important role and wide applications in image acquisition, storage, transmission and processing. In designing IQA models, human visual system (HVS) characteristics introduced play an important role in improving their performances. In this paper, combining image distortion characteristics with HVS characteristics, based on the structure similarity index (SSIM) model, a novel IQA model based on the perceived structure similarity index (PSIM) of image is proposed. In the method, first, a perception model for HVS perceiving real images is proposed, combining the contrast sensitivity, frequency sensitivity, luminance nonlinearity and masking characteristics of HVS; then, in order to simulate HVS perceiving real image, the real images are processed with the proposed perception model, to eliminate their visual redundancy, thus, the perceived images are obtained; finally, based on the idea and modeling method of SSIM, combining with the features of perceived image, a novel IQA model, namely PSIM, is proposed. Further, in order to illustrate the performance of PSIM, 5335 distorted images with 41 distortion types in four image databases (TID2013, CSIQ, LIVE and CID) are used to simulate from three aspects: overall IQA of each database, IQA for each distortion type of images, and IQA for special distortion types of images. Further, according to the comprehensive benefit of precision, generalization performance and complexity, their IQA results are compared with those of 12 existing IQA models. The experimental results show that the accuracy (PLCC) of PSIM is 9.91% higher than that of SSIM in four databases, on average; and its performance is better than that of 12 existing IQA models. Synthesizing experimental results and theoretical analysis, it is showed that the proposed PSIM model is an effective and excellent IQA model.

Malus micromalus Makino phenolic extract preserves hepatorenal function by regulating PKC-α signaling pathway and attenuating endoplasmic reticulum stress in lead (II) exposure mice.

Lead (Pb), which widely recognized as a nonessential heavy metal and a major environmental contamination, is a growing threat to the ecosystem and human body. In the present study, Malus micromalus Makino cv. 'Dong Hong' phenolic extract (MMPE) has been used to antagonise Pb-induced erythrocyte injury, hepatic and renal dysfunction in mice. Six-week-old male Kunming mice were gavaged with PbCl2 (20 mg/kg mouse/day) and/or MMPE (100 mg/kg mouse/day) by gavage administration for 10 days. We evaluated erythrocyte fragility, relative organ mass, biochemical parameters and histopathological changes to evaluate the protection effect of MMPE on the injury of liver and kidney in Pb-treated mice. MMPE significantly inhibited the increase of protein kinase C-α, B-cell lymphoma-2-associated X, cytochrome C and Caspase-3 protein levels and decreased calreticulin protein expression level in Pb-exposed mice. MMPE supplementation could maintain the integrity of erythrocyte membranes and ameliorate the endoplasmic reticulum stress in Pb-treated mice. It suggested MMPE as a natural nutritional supplement to alleviate Pb-induced hazardous effects in Pb-exposed humans.

Study on the mechanism underlying Al-induced hepatotoxicity based on the identification of the Al-binding proteins in liver.

Aluminum (Al) is the most abundant metal element in the earth's crust, and is implicated in the pathogenesis of liver lesions. However, the mechanisms underlying Al3+-induced hepatotoxicity are still largely elusive. Based on analysis with native gel electrophoresis, Al3+ plus 8-hydroxyquinoline staining and LC-MS/MS, the proteins with high Al3+ affinity were identified to be carbamoyl-phosphate synthase, adenosylhomocysteinase, heat shock protein 90-alpha, carbonic anhydrase 3, serum albumin and calreticulin. These proteins are involved in physiological processes such as the urea cycle, redox reactions, apoptosis and so on. Then we established an Al3+-treated rat model for biochemical tests, morphology observation and Ca2+ homeostasis analysis, in order to evaluate the extent of oxidative damage, hepatic histopathology and specific indicators of Al3+-related proteins in liver. Our findings indicated the high-affinity interactions with Al3+ perturbed the normal function of the above proteins, which could account for the mechanism underlying Al3+-induced hepatotoxicity.