344 research outputs found

    Solar Cell Design Using Metamaterials

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    Natural structure with simultaneous negative permittivity and permeability has not been discovered yet. However, using specially-designed metal embedded in dielectric bodies can achieve a kind of artificial negative index. This periodic structure which is smaller than the guided wavelength is known as a metamaterial. However, recent designs of metamaterials have some disadvantages when they are used in the application of solar cell. The perfect absorption is only within a narrow band, and for most of the solar spectrum, the absorption is no more than 10%. Here, a new kind of absorber for the solar spectrum has been designed and analyzed, in order to utilize the solar energy effectively

    A Digital Watermarking Approach Based on DCT Domain Combining QR Code and Chaotic Theory

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    This paper proposes a robust watermarking approach based on Discrete Cosine Transform domain that combines Quick Response Code and chaotic system.Comment: 7 pages, 6 figure

    Cytokines in the Progression of Pancreatic β-Cell Dysfunction

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    The dysfunction of pancreatic β-cell and the reduction in β-cell mass are the decisive events in the progression of type 2 diabetes. There is increasing evidence that cytokines play important roles in the procedure of β-cell failure. Cytokines, such as IL-1β, IFN-γ, TNF-α, leptin, resistin, adiponectin, and visfatin, have been shown to diversely regulate pancreatic β-cell function. Recently, islet-derived cytokine PANcreatic DERived factor (PANDER or FAM3B) has also been demonstrated to be a regulator of islet β-cell function. The change in cytokine profile in islet and plasma is associated with pancreatic β-cell dysfunction and apoptosis. In this paper, we summarize and discuss the recent studies on the effects of certain important cytokines on pancreatic β-cell function. The imbalance in deleterious and protective cytokines plays pivotal roles in the development and progression of pancreatic β-cell dysfunction under insulin-resistant conditions

    The First Case of a Class I Glucose-6-phosphate Dehydrogenase Deficiency, G6PD Santiago de Cuba (1339 GA), in a Chinese Population as Found in a Survey for G6PD Deficiency in Northeastern and Central China

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    In Liaoning Province in northeastern China, we found a G6PD-deficient patient at the age of 3. By the classification of the World Health Organization, this patient was categorized as class I (very severe G6PD deficiency). When we investigated the G6PD gene of the patient, we found that he had a replacement of G to A at nucleotide 1339. As a result, the amino acid at position 447 should change from Gly to Arg. This replacement is known as G6PD Santiago de Cuba, because it was first discovered in a Cuban boy who showed heavy chronic anemia. Today, 28 G6PD variants have been reported in the Chinese population, and all are categorized as class II (severe deficiency) or class III (mild deficiency);in class II or III deficiency, anemia is not present in daily life, but hemolytic attack can occur when the carrier ingests certain oxidative medicines or foods. This is the first report of a G6PD-deficient Chinese patient in the category of class I. We intended to find other G6PD-deficient cases in northeastern China and tested several hundred blood samples, but no cases of G6PD deficiency were found (0/414). In central China, where falciparum malaria was endemic from the 1950s to 1970s, we found two G6PD-deficient cases (2/27) and the other members from their families whose variant type was G6PD Kaiping (1388GT), which is a common variant in the Chinese population.</p

    Suppression of FM-to-AM conversion in third-harmonic generation at the retracing point of a crystal

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    FM-to-AM conversion can cause many negative effects (e.g., reducing of margin against damage to the optics, and etc.) on performances of third-harmonic conversion system. In this letter, the FM-to-AM conversion effect in third-harmonic generation is investigated both at and away from the retracing point of type-II KDP crystal. Obtained results indicate that the FM-to-AM conversion can be suppressed effectively when the crystal works at the retracing point.Comment: 8 pages, 5 figures, 1 tabl

    Screening high potassium efficiency potato genotypes and physiological responses at different potassium levels

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    Potato (Solanum tuberosum L.) growth and production is highly dependent on potassium (K) levels in the soil. Southwest China is the largest potato production region but it has low availability of soil potassium. To assess the genetic variation in K use efficiency, 20 potato genotypes were collected to compare the yield and K content in a pot experiment. Moreover, ‘Huayu-5’ and ‘Zhongshu-19’ were cultivated in five K applications to investigate the K distribution and sucrose in different organs. The results indicated that there were highly significant effects of K, genotype and K×G interactions on tuber yield, plant and tuber K content, plant K uptake efficiency and K harvest index. Cluster analysis classified 20 potato genotypes into four types: DH (high efficiency at low and high K application), LKH (high efficiency at low K application), HKH (high efficiency at high K application) and DL (low efficiency at low and high K application). The potassium distribution percentage in the tubers of the potassium-efficient genotype was higher than that of the potassium-inefficient genotype under low potassium application. The sucrose content in the tuber gently declined as the application of K rose in both cultivars, and that in the tuber of ‘Huayu-5’ was higher than that in ‘Zhongshu-19’. ‘Huayu-5’ reached the highest yield when the potassium application was 159.45 kg ha-1, and ‘Zhongshu-19’ reached the highest yield when the potassium application was 281.4 kg ha-1. This study indicated that genetic variation for K utilization efficiency existed among 20 genotypes, and yield in low K application and relative yield were suitable criteria for screening K utilization efficiency genotypes
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