24 research outputs found

    Resonant transmission of light through surface plasmon structures

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    Plasmonics enables the realization of new optical components. Here, we report yet another plasmonic component based on a pair of surfaces displaying grating coupled plasmon enhanced transmission. We observe high quality factor transmission peaks as high as 100 through our plasmonic filter based on gratings obtained directly from optical storage disks. Wavelength and polarization dependent transmission is also demonstrated in the visible and infrared portions of the spectrum. The resonance wavelength of this filter can be tuned by simply changing the angle of incidence. Numerical calculations agree well with measurements. Our work can open up directions toward disposable optical components such as filters and polarizers. © 2009 American Institute of Physics

    Biochemical stress indicators of greater wax moth exposure to organophosphorus insecticides

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    Although acetyleholinesterase (AChE) is the primary target of organophosphorus insecticides (OPs), increasing evidence regarding their secondary effects suggests that OP's disturb homeostasis of insects by generating free radical intermediates that trigger lipid peroxidation. We therefore investigated alterations in lipid peroxidation product, malondialdehyde (MDA) content, and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, in conjunction with AChE activity as biochemical stress indicators in greater wax moth, Galleria mellonella (L.) larvae for OPs methyl parathion (MP) and ethyl parathion (EP). The effects of MP and EP were first investigated by rearing the young larvae on an artificial diet containing 0.01, 0.1, 1, 10, and 100 ppm of each insecticide. Second, the mature larvae were injected with 0.05, 0.5, 5, 50, and 500 ng of insecticides for determining the changes in biochemical stress responses. The diet with lowest level of MP significantly decreased the activities of all measured enzymes, whereas it increased MDA content. However ALT and AST were significantly higher in the larvae reared with the diet with high levels of MP than in control larvae. All tested levels of MP resulted in a decrease in AChE activity. The lowest level of EP in diet (0.01 ppm) significantly increased ALT activity, whereas it reduced that of AChE. This insecticide at 0.1 ppm resulted in reduced AST activity, but 1 ppm in diet elevated AST activity and MDA content. EP at 0.1 ppm and higher levels in the diet reduced ALT activity. All dietary EP levels significantly decreased AChE activity. ALT, AST, and AChE were lower in larvae fed with the diet containing 100 ppm ethyl parathion compared with larvae on control diet. MP at 50 ng per larva increased ALT and AST activities from 35.42 +/- 0.74 and 26.34 +/- 0.83 to 203.57 +/- 1.09, and 122.90 +/- 1.21 U/g, respectively, when the mature larvae were injected. All injected doses of EP dramatically reduced both ALT and AST activities, but only the lowest and highest levels of this insecticide decreased AChE activity. The lowest level of this insecticide also significantly increased MDA content in larvae. High levels of both insecticides increased MDA content. We observed a significant higher increase in MDA content in the larvae reared with 10 ppm EP (102.16 +/- 1.57 nmol/g protein) than the control group (30.28 +/- 1.42 nmol/g protein). These results suggest that OPs caused the metabolic and synaptic dysfunctions in greater wax moth and alter its biochemical physiology in response to oxidative stress

    The Importance of Quality Control within the Relationship between the Quality Engineering and Taguchi Methodology

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    © (2015) Trans Tech Publications, Switzerland.Nowadays there is a strong relationship between the quality control and quality engineering in the modern advanced manufacturing. Quality engineering is an interdisciplinary science which is concerned with not only producing satisfactory products for customers but also reducing the total loss. Quality engineering involves engineering design, process operations, aftersales services, economics and statistics. Although the Taguchi Robust Design is the first concept comes to mind when thinking of quality engineering, the definition of this major has been used in different manners in the literature. There are also differences on the definition of the quality which has been made by experts. The aim of this study is to contribute to the literature to avoid deviations on definition of the concept of "Quality Engineering", which has not been defined yet by ISO - International Organization for Standardization. This study pointed out that the process of quality control is a part of on-line quality engineering rather than off-line phase and tries to ensure planned and/or improved values are satisfied during mass production

    The importance of quality control within the relationship between the quality engineering and Taguchi methodology

    No full text
    © (2015) Trans Tech Publications, Switzerland.Nowadays there is a strong relationship between the quality control and quality engineering in the modern advanced manufacturing. Quality engineering is an interdisciplinary science which is concerned with not only producing satisfactory products for customers but also reducing the total loss. Quality engineering involves engineering design, process operations, aftersales services, economics and statistics. Although the Taguchi Robust Design is the first concept comes to mind when thinking of quality engineering, the definition of this major has been used in different manners in the literature. There are also differences on the definition of the quality which has been made by experts. The aim of this study is to contribute to the literature to avoid deviations on definition of the concept of "Quality Engineering", which has not been defined yet by ISO - International Organization for Standardization. This study pointed out that the process of quality control is a part of on-line quality engineering rather than off-line phase and tries to ensure planned and/or improved values are satisfied during mass production

    Multiple distant metastases in a case of malignant pleural mesothelioma

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    AbstractIntroductionMalignant pleural mesothelioma (MPM) is a malignant of mesodermal neoplasm and arises from multipotential mesothelial or subserosal cells of the pleura, pericardium and peritoneum.CaseA seventy five year-old male patient was admitted with chest and lower limb pain. He was a heavy smoker and exposed to environmental asbestos in his childhood. PET-CT scans showed multiple pathological FDG uptakes in lungs and other organs. Biopsies performed from lung and anterior thigh muscles were reported as epitheloid type malignant pleural mesothelioma.DiscussionWe emphasize that unexpected distant metastases can be observed in MPM and occasionally primary diagnosis can be determined by the biopsy of the metastatic regions. This case also points out the role of PET-CT in the staging of malign mesothelioma by determining different metastatic sites

    Effects of curcumin on tumour necrosis factor-alpha and interleukin-6 in the late phase of experimental acute pancreatitis

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    Inflammatory cytokines have been demonstrated to play an important role in the induction and severity of acute pancreatitis (AP) in the recent studies. The aim of this study was to investigate the effects of curcumin on inflammatory cytokines, such as tumour necrosis factor (TNF)-alpha and interleukin (IL)-6 in the late phase of AP. The study was conducted on 40 male Wistar Albino rats. The animals were divided randomly into four equal groups. AP was induced by the infusion of 3% sodium taurocholate into the biliopancreatic duct (in groups I and II). Starting on day 20 prior to the induction of AP, rats in group I received daily dose of 100 mg/kg of curcumin, dissolved in 9% ethanol via an intragastric tube. The same procedure was repeated for 6 days following the onset of AP. Group III was infused only on saline solution. Group IV (curcumin control group) received 9% ethanol via an intragastric tube, during the experimental period (totally 26 days). All the animals were sacrificed on day 6 after the collection of blood samples and serum TNF-alpha and IL-6 levels were determined. Tissue samples were taken from pancreas, mesenteric lymph nodes, liver, lungs, spleen and the kidneys for histopathological evaluation. Serum TNF-alpha and IL-6 levels in the group, which received curcumin (group I), were determined to be significantly lower than those of the untreated group (group II) (P < 0.05). No statistically significant difference was detected in terms of total histopathological scores in the treatment group versus untreated group. Curcumin has been shown to markedly reduce serum TNF-alpha and IL-6 levels in the late phase of AP, but failed in the prevention of tissue injury
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