756 research outputs found
The Role of Manganese Superoxide Dismutase in Skin Cancer
Recent studies have shown that antioxidant enzyme expression and activity are drastically reduced in most human skin diseases, leading to propagation of oxidative stress and continuous disease progression. However, antioxidants, an endogenous defense system against reactive oxygen species (ROS), can be induced by exogenous sources, resulting in protective effects against associated oxidative injury. Many studies have shown that the induction of antioxidants is an effective strategy to combat various disease states. In one approach, a SOD mimetic was applied topically to mouse skin in the two-stage skin carcinogenesis model. This method effectively reduced oxidative injury and proliferation without interfering with apoptosis. In another approach, Protandim, a combination of 5 well-studied medicinal plants, was given via dietary administration and significantly decreased tumor incidence and multiplicity by 33% and 57%, respectively. These studies suggest that alterations in antioxidant response may be a novel approach to chemoprevention. This paper focuses on how regulation of antioxidant expression and activity can be modulated in skin disease and the potential clinical implications of antioxidant-based therapies
Characterization of Ductile Crack Propagation by Fractal Energy Dissipation Rate
Because of its geometry dependence and loss of physical meaning, the incremental crack
resistance curve cannot characterize ductile fractures with large crack extensions and plastic deformations. Therefore, the energy dissipation rate R is employed to overcome these deficiencies, even though specimen size effects still exist. In the study, considering the fractal crack path and concomitant plastic dissipation in the fractal domain, a scale‑invariant energy dissipation rate, γp*, is proposed in the context of renormalization group theory. Some experiments in the literature have validated this approach. The fitted fractal energy dissipation rate is independent of the specimen size and initial crack length; moreover, as the specimen size increases, progressive fractality vanishing is found consistently with geometrical multifractality
Investigation on Remote Monitoring System for Heat-Supply Thermal Characters Based GPRS
AbstractWith the strategy requirements of low-carbon and energy-saving, the appropriate auto-control methods become more and more important. Aiming to monitor the thermal characters of the heat exchange station in the real time, the investigation framework in this paper presents an integral solution. We incorporate wireless data gathering from different heat exchange station, sending data to the service through the Internet and managing by sever.Net. We exploit formalization software by three-layer Browser-Server structure to regulate how thermal characters data should be gathered, communicated among concerned parties and interpreted to server/Date Base in decision-making. Meanwhile, the communication among the nodes that form the distributed system is implemented by means of the utilization of wireless networks, and secondary data transmission services (GSM or GPRS) provided by a mobile telephone operator. This monitoring system has been running in good condition and stable operation with lower fault rate and higher credibility data. This system, once fully deployed, can significantly reduce human labor and provide real-time data monitoring to achieve the propose of energy conservation and emission reduction
Ursodeoxycholic acid lowers bile lithogenicity by regulating SCP2 expression in rabbit cholesterol gallstone models
Aims: We designed this study to get insight into the disorder of lipid metabolism during cholesterol gallstone formation and evaluate the effect of ursodeoxycholic acid on the improvement of bile lithogenicity and on expression of lipid related genes.
Methods: Rabbit cholesterol gallstone models were induced by high cholesterol diet. Bile,
blood and liver tissues were obtained from rabbits after 0, 1, 2, 3, 4 and 5 weeks. Bile and blood lipids were measured enzymatically. 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), cytochrome P450, family 7, subfamily A, polypeptide 1 (CYP7A1) and sterol carrier protein 2 (SCP2) mRNA expressions were detected by using quantitative real-time RT-PCR. Cholesterol saturation index (CSI) was calculated by using Carey table to represent the bile lithogenicity.
Results: Rates of gallstone formation of the 4 and 5 week treatment groups were 100 %, but
that of the ursodeoxycholic acid treatment group was only 33.3 %. Expression of HMGCR
and SCP2 mRNA in the 4 week group was upregulated and that of CYP7A1 mRNA decreased
as compared with the 0 week group. Ursodeoxycholic acid could significantly extend nucleation time of bile and lower CSI. Ursodeoxycholic acid could reduce the expression of SCP2, but couldn’t influence expression of HMGCR and CYP7A1.
Conclusions: Abnormal expression of HMGCR, CYP7A1 and SCP2 might lead to high lithogenicity of bile. Ursodeoxycholic acid could improve bile lipids and lower bile lithogenicity, thereby reducing the incidence of gallstones. So it might be a good preventive drug for cholesterol
gallstones
Colour alignment for relative colour constancy via non-standard references
Relative colour constancy is an essential requirement for many scientific
imaging applications. However, most digital cameras differ in their image
formations and native sensor output is usually inaccessible, e.g., in
smartphone camera applications. This makes it hard to achieve consistent colour
assessment across a range of devices, and that undermines the performance of
computer vision algorithms. To resolve this issue, we propose a colour
alignment model that considers the camera image formation as a black-box and
formulates colour alignment as a three-step process: camera response
calibration, response linearisation, and colour matching. The proposed model
works with non-standard colour references, i.e., colour patches without knowing
the true colour values, by utilising a novel balance-of-linear-distances
feature. It is equivalent to determining the camera parameters through an
unsupervised process. It also works with a minimum number of corresponding
colour patches across the images to be colour aligned to deliver the applicable
processing. Two challenging image datasets collected by multiple cameras under
various illumination and exposure conditions were used to evaluate the model.
Performance benchmarks demonstrated that our model achieved superior
performance compared to other popular and state-of-the-art methods.Comment: 14 pages, 8 figures, 2 tables, accepted by IEEE Transactions on Image
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