Seven symptomatic patients with Wilson's disease have so far been diagnosed at King Khalid University Hospital (KKUH), Riyadh, over the last six years. On family screening, another three asymptomatic patients were found to be affected. Five of the symptomatic patients had clinical features of liver disease on initial presentation and was preceded by renal dysfunction in another patient. The remaining patient presented with neurological features. Six patients had Kayser-Fleisher ring. Abnormal liver function tests were found in half of the patients. Ceruloplasmin was reduced in 7 of 10 patients. Serum copper and urinary copper estimations were most useful diagnostic laboratory tests. Morphological alteration was found in all 9 patients who had a percutaneous liver biopsy. All patients were treated initially with D-penicillamine and clinical response was noted in seven, of whom one developed neurological manifestations while receiving the treatment. D-penicillamine was replaced by zinc sulfate in 3 patients who developed thrombocytopenia. The data suggest that Wilson's disease may not be rare in Saudi Arabia. For early detection and prompt treatment, the disease should be suspected under appropriate clinical circumstances especially in young patients with liver diseases. Close relatives of such index patients should be routinely screened. 相似文献
A generalized enthalpy-temperature correlation for light hydrocarbon vapor has been developed to represent the data for a wide range of temperatures 460-1080°F. Detailed analysis shows that the proposed correlation fits the experimental measurements of vapor enthalpy with the corresponding calculated values with an overall absolute error of 1.8% for 131 data points. 相似文献
In this study, soymilk powder was produced by spray drying. The inlet air temperature of spray dryer was varied from 200 to 280°C and the feed concentration was varied from 15 to 25% (w/v). Response surface methodology was used to examine the effects of these independent variables on the detailed characteristics in terms of physical, structural, functional properties of powder. Overall, results show that rising the inlet air temperature caused a decrease in tapped and loose bulk density, true density, filling rate, water holding capacity, and water content of powder; and an increase in compressibility, Hausner ratio, porosity, interstitial air volume, and wettability index. An increase in feed concentration led to an increase in true density, compressibility, Hausner ratio, porosity, interstitial air volume, and wettability index; and a decrease in tapped and loose bulk density, filling rate, water holding capacity, and water content; whereas oil holding capacity might be increased or decreased and it depended almost solely on the feed concentration. 相似文献
Presently, the design and development of an effective image steganography system are facing several challenges including the low capacity, poor robustness and imperceptibility. To surmount such limitations, it is important to improve the capacity and security of the steganography system while maintaining a high signal-to-noise ratio (PSNR). Based on these factors, this study is aimed to design and develop a distinction grade value (DGV) method to effectively embed the secret data into a cover image for achieving a robust steganography scheme. The design and implementation of the proposed scheme involved three phases. First, a new encryption method called the shuffle the segments of secret message (SSSM) was incorporated with an enhanced Huffman compression algorithm to improve the text security and payload capacity of the scheme. Second, the Fibonacci-based image transformation decomposition method was used to extend the pixel’s bit from 8 to 12 for improving the robustness of the scheme. Third, an improved embedding method was utilized by integrating a random block/pixel selection with the DGV and implicit secret key generation for enhancing the imperceptibility of the scheme. The performance of the proposed scheme is assessed experimentally to determine the imperceptibility, security, robustness and capacity. The resistance of the proposed scheme is tested against the statistical, χ2, Histogram and non-structural steganalysis detection attacks. The obtained PSNR values revealed the accomplishment of the higher imperceptibility and security by the proposed DGV scheme while maintaining higher capacity compared to the reported findings. In short, the proposed steganography scheme outperformed the commercially available data hiding schemes, thereby resolved the existing issues.
Wireless Personal Communications - Present-day wireless methods are necessary to support a variety of higher-speed data communication facilities for its subscribers such as cloud-based video... 相似文献
Nowadays, the security of communication becomes very important with the rapid development of network technology. So, the transmission and distribution of the several digital information must be protected and secured against other users. Many steganography techniques have been proposed for embedding secret digital data in other digital data. In this article, we propose a new steganography algorithm based on a linear algebraic tool that is the polar decomposition (PD) for hiding secret data in an image. A host image is selected and divided into blocks of size 2 × 2, a PD is applied on each block, and the secret data are embedded in suitable blocks. Experimental results show that our proposed algorithm gives a higher hiding capacity, achieves good imperceptibility, and also provides a high degree of security against common types of attacks such as compression attack with quality 10%, gamma correction attack, and impulse noise attack. 相似文献
In solid-liquid separation of coal preparation plant tailings by flocculation, in addition to the type and amount of flocculants, the composition of waste materials including clay minerals must be determined in order to devise an effective and economic sedimentation system. In this study, the characterization of organic and inorganic impurities was made with the help of mineralogical data and instrumental analysis techniques. The effects of polymer type (medium and low anionic, cationic and nonionic), polymer dosage and suspension pH on flocculation mechanism of tailings particles (-0.18 mm) in the Tun?bilek Coal Preparation Plant tailings of Tun?bilek (Turkey) were investigated. Medium anionic polymer accelerated the settling rate of particles. An optimum settling rate (300 mm/min) was reached at a dosage rate of 34.19 g/ton-solids (2.0 mg/l), 51.28 g/ton-solids (3.0 mg/l), 102.56 g/ton-solids (6.0 mg/l) and 119.66 g/ton-solids (7.0mg/l) for medium anionic, low charged anionic, nonionic and cationic polymers, respectively. The lowest turbidity values at low polymer dosages were obtained by the cationic polymer at around 25.64 g/ton-solids (1.5 mg/l) polymer dosages; however, the low anionic and nonionic polymers produced lower turbidity values at higher dosages (>25.64 g/ton-solids). At optimum dosages of the polymer, the settling rate decreased at low and high pHs indicating that the natural pH (pH 8.3) of the suspension is the most appropriate pH for the settling rate. On the other hand, the water clarity values at natural pHs were high for all of the polymers. 相似文献