Cytochrome P-450 dependent ethanol oxidation. Kinetic isotope effects and absence of stereoselectivity

International Nuclear Information System (INIS)

Ekstroem, G.; Norsten, C.; Cronholm, T.; Ingelman-Sundberg, M.

1987-01-01

Deuterium isotope effects [/sup D/(V/K)] and stereoselectivity of ethanol oxidation in cytochrome P-450 containing systems and in the xanthine-xanthine oxidase system were compared with those of yeast alcohol dehydrogenase. The isotope effects were determined by using both a noncompetitive method, including incubation of unlabeled of [1,1- 2 H 2 ] ethanol at various concentrations, and a competitive method, where 1:1 mixtures of [1- 13 C]- and [ 2 H 6 ] ethanol or [2,2,2- 2 H 3 ]- and [1,1- 2 H 2 ] ethanol were incubated and the acetaldehyde formed was analyzed by gas chromatography/mass spectrometry. The /sup D/(V/K) isotope effects of the cytochrome P-450 dependent ethanol oxidation were about 4 with liver microsomes from imidazole-, phenobarbital- or acetone-treated rabbits or with microsomes from acetone- or ethanol-treated rats. Similar isotope effects were reached with reconstituted membranes containing the rabbit ethanol-inducible cytochrome P-450 (LMeb), whereas control rat microsomes and membranes containing rabbit phenobarbital-inducible P-450 LM 2 oxidized the alcohol with /sup D/(V/K) of about 2.8 and 1.8, respectively. Addition of Fe/sup III/EDTA either to microsomes from phenobarbital-treated rabbits or to membranes containing P-450 LMeb significantly lowered the isotope effect. Incubations of all cytochrome P-450 containing systems of the xanthine-xanthine oxidase systems with (1R)- and (1S)-[1- 2 H] ethanol, revealed, taking the isotope effects into account, that 44-66% of the ethanol oxidized had lost the 1-pro-R hydrogen. The data indicate that cytochrome P-450 dependent ethanol oxidation is not stereospecific and that cleavage of the C 1 -H bond appears to be a rate-determining step in the catalysis by the ethanol-inducible form of P-450. The contribution of hydroxyl radicals in ethanol oxidation by the various enzymic systems is discussed

Effects of Exercise Intensity on Postexercise Endothelial Function and Oxidative Stress

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Conor McClean

2015-01-01

Full Text Available Purpose. To measure endothelial function and oxidative stress immediately, 90 minutes, and three hours after exercise of varying intensities. Methods. Sixteen apparently healthy men completed three exercise bouts of treadmill running for 30 minutes at 55% V˙O2max (mild; 20 minutes at 75% V˙O2max (moderate; or 5 minutes at 100% V˙O2max (maximal in random order. Brachial artery flow-mediated dilation (FMD was assessed with venous blood samples drawn for measurement of endothelin-1 (ET-1, lipid hydroperoxides (LOOHs, and lipid soluble antioxidants. Results. LOOH increased immediately following moderate exercise (P0.05. Conclusions. Acute exercise at different intensities elicits varied effects on oxidative stress, shear rate, and ET-1 that do not appear to mediate changes in endothelial function measured by FMD.

Exercise and oxidative stress: potential effects of antioxidant dietary strategies in sports.

Science.gov (United States)

Pingitore, Alessandro; Lima, Giuseppina Pace Pereira; Mastorci, Francesca; Quinones, Alfredo; Iervasi, Giorgio; Vassalle, Cristina

2015-01-01

Free radicals are produced during aerobic cellular metabolism and have key roles as regulatory mediators in signaling processes. Oxidative stress reflects an imbalance between production of reactive oxygen species and an adequate antioxidant defense. This adverse condition may lead to cellular and tissue damage of components, and is involved in different physiopathological states, including aging, exercise, inflammatory, cardiovascular and neurodegenerative diseases, and cancer. In particular, the relationship between exercise and oxidative stress is extremely complex, depending on the mode, intensity, and duration of exercise. Regular moderate training appears beneficial for oxidative stress and health. Conversely, acute exercise leads to increased oxidative stress, although this same stimulus is necessary to allow an up-regulation in endogenous antioxidant defenses (hormesis). Supporting endogenous defenses with additional oral antioxidant supplementation may represent a suitable noninvasive tool for preventing or reducing oxidative stress during training. However, excess of exogenous antioxidants may have detrimental effects on health and performance. Whole foods, rather than capsules, contain antioxidants in natural ratios and proportions, which may act in synergy to optimize the antioxidant effect. Thus, an adequate intake of vitamins and minerals through a varied and balanced diet remains the best approach to maintain an optimal antioxidant status. Antioxidant supplementation may be warranted in particular conditions, when athletes are exposed to high oxidative stress or fail to meet dietary antioxidant requirements. Aim of this review is to discuss the evidence on the relationship between exercise and oxidative stress, and the potential effects of dietary strategies in athletes. The differences between diet and exogenous supplementation as well as available tools to estimate effectiveness of antioxidant intake are also reported. Finally, we advocate the need

Effects of adsorbates on Zircaloy oxidation in air

International Nuclear Information System (INIS)

Cho, Y.; Kim, Y-G.; Park, K.

1997-01-01

The air-oxidation of Zry and the effects of adsorbates on the oxidation are found by the intermittent measurement of the weight gain of specimens. NaC1 enhances the oxidation, where nonuniform stresses on the surface and C1 ions are the cause. LiOH also enhances the oxidation, where the initial oxide formed by LiOH seems to the reason. The effects of fluorides on oxidation are also measured. NaF is most harmful and KF follows next. LiF does not effect the oxidation of Zry. Diffusion of fluorides in oxide determines the enhancement. (author)

Protective Effect of Nitric Oxide (NO against Oxidative Damage in Larix gmelinii Seedlings under Ultraviolet-B Irradiation

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Haiqing Hu

2016-10-01

Full Text Available Ultraviolet-B (UV-B stress appears to be more striking than other research works because of the thin ozone layer. The protective influence of an exogenous nitric oxide donor and sodium nitroprusside (SNP on the growth properties of Larix gmelinii seedlings was investigated under ultraviolet-B radiation conditions. The results indicated that 0.1 mM SNP could effectively alleviate the damage caused by ultraviolet-B radiation, and improved the seedling growth properties, the relative water content, and photosynthetic pigment content in leaves. Additionally, the photosynthetic capacity and antioxidant enzyme activity were increased during the exposure. On the contrary, the damage caused by active oxygen was decreased in SNP-treated seedling leaves. The damage caused by ultraviolet-B radiation was slightly reduced after treating with 0.01 mM SNP. Nevertheless, treatment with 0.5 mM SNP had a negative effect under ultraviolet-B radiation. Furthermore, supplementing NO (nitric oxide improved the photosynthetic capacity and antioxidant enzyme activity and alleviated the damage of caused by active oxygen. The best effective concentration of SNP was 0.1 mM. Therefore, a suitable amount of exogenous NO can protect the Larix gmelinii seedlings and increase their tolerance to ultraviolet-B radiation.

Molecular-beam-deposited yttrium-oxide dielectrics in aluminum-gated metal - oxide - semiconductor field-effect transistors: Effective electron mobility

International Nuclear Information System (INIS)

Ragnarsson, L.-A degree.; Guha, S.; Copel, M.; Cartier, E.; Bojarczuk, N. A.; Karasinski, J.

2001-01-01

We report on high effective mobilities in yttrium-oxide-based n-channel metal - oxide - semiconductor field-effect transistors (MOSFETs) with aluminum gates. The yttrium oxide was grown in ultrahigh vacuum using a reactive atomic-beam-deposition system. Medium-energy ion-scattering studies indicate an oxide with an approximate composition of Y 2 O 3 on top of a thin layer of interfacial SiO 2 . The thickness of this interfacial oxide as well as the effective mobility are found to be dependent on the postgrowth anneal conditions. Optimum conditions result in mobilities approaching that of SiO 2 -based MOSFETs at higher fields with peak mobilities at approximately 210 cm 2 /Vs. [copyright] 2001 American Institute of Physics

Arginine appearance and nitric oxide synthesis in critically ill infants can be increased with a protein-energy–enriched enteral formula12345

Science.gov (United States)

de Betue, Carlijn TI; Joosten, Koen FM; Deutz, Nicolaas EP; Vreugdenhil, Anita CE; van Waardenburg, Dick A

2013-01-01

Background: Arginine is considered an essential amino acid during critical illness in children, and supplementation of arginine has been proposed to improve arginine availability to facilitate nitric oxide (NO) synthesis. Protein-energy–enriched enteral formulas (PE-formulas) can improve nutrient intake and promote anabolism in critically ill infants. However, the effect of increased protein and energy intake on arginine metabolism is not known. Objective: We investigated the effect of a PE-formula compared with that of a standard infant formula (S-formula) on arginine kinetics in critically ill infants. Design: A 2-h stable-isotope tracer protocol was conducted in 2 groups of critically ill infants with respiratory failure because of viral bronchiolitis, who received either a PE-formula (n = 8) or S-formula (n = 10) in a randomized, blinded, controlled setting. Data were reported as means ± SDs. Results: The intake of a PE-formula in critically ill infants (aged 0.23 ± 0.14 y) resulted in an increased arginine appearance (PE-formula: 248 ± 114 μmol · kg−1 · h−1; S-formula: 130 ± 53 μmol · kg−1 · h−1; P = 0.012) and NO synthesis (PE-formula: 1.92 ± 0.99 μmol · kg−1 · h−1; S-formula: 0.84 ± 0.36 μmol · kg−1 · h−1; P = 0.003), whereas citrulline production and plasma arginine concentrations were unaffected. Conclusion: In critically ill infants with respiratory failure because of viral bronchiolitis, the intake of a PE-formula increases arginine availability by increasing arginine appearance, which leads to increased NO synthesis, independent of plasma arginine concentrations. This trial was registered at www.trialregister.nl as NTR515. PMID:23945723

Effect of aspartame on biochemical and oxidative stress parameters in rat blood

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Prokić Marko D.

2015-01-01

Full Text Available Aspartame (ASP is one of the most widely used nonnutritive sweeteners. This study investigates the chronic effects of ASP on hematological and biochemical parameters, and its effects on the oxidative/antioxidative status in the red blood cells of Wistar albino rats. Rats were provided with ASP (40 mg/kg/daily for six weeks in drinking water. Increased food and fluid intake was observed in the ASP-treated rats. Total body mass was significantly decreased in the ASP-treated rats. Treatment with ASP caused an increase in the concentrations of glucose, cholesterol, LDL-cholesterol, and in the activities of alanine aminotransferase (ALT, aspartate aminotransferase (AST and lactate dehydrogenase (LDH, as well as a decrease in the levels of HDL-cholesterol in the serum. A significant decline in the number of white blood cells (WBC was observed after ASP uptake. Based on the results we conclude that ASP induces oxidative stress, observed as an alteration of the glutathione redox status, which leads to increased concentrations of nitric oxide (NO and lipid peroxides (LPO in the red blood cells. Changes in biochemical parameters, lipid metabolism, as well as changes in the levels of oxidative stress markers and the appearance of signs of liver damage indicate that chronic use of ASP can lead to the development of hyperglycemia, hypercholesterolemia and associated diseases. [Projekat Ministarstva nauke Republike Srbije, br. 173041

Transmission electron microscopy of oxide dispersion strengthened (ODS) molybdenum: effects of irradiation on material microstructure

International Nuclear Information System (INIS)

Baranwal, R.; Burke, M.G.

2003-01-01

Oxide dispersion strengthened (ODS) molybdenum has been characterized using transmission electron microscopy (TEM) to determine the effects of irradiation on material microstructure. This work describes the results-to-date from TEM characterization of unirradiated and irradiated ODS molybdenum. The general microstructure of the unirradiated material consists of fine molybdenum grains (< 5 (micro)m average grain size) with numerous low angle boundaries and isolated dislocation networks. 'Ribbon'-like lanthanum oxides are aligned along the working direction of the product form and are frequently associated with grain boundaries, serving to inhibit grain boundary and dislocation movement. In addition to the 'ribbons', discrete lanthanum oxide particles have also been detected. After irradiation, the material is characterized by the presence of nonuniformly distributed large (∼ 20 to 100 nm in diameter), multi-faceted voids, while the molybdenum grain size and oxide morphology appear to be unaffected by irradiation

Effect of TMP variables upon structure and properties in ODS alloy HDA 8077 sheet. [ThermoMechanical Processing of Oxide Dispersion Strengthened nickel alloy

Science.gov (United States)

Rothman, M. F.; Tawancy, H. M.

1980-01-01

The effects of oxide content level and variations in thermomechanical processing upon the final structure and properties of HDA 8077 sheet have been systematically examined. It was found that creep strength and formability are substantially influenced by both oxide content and TMP schedule. Variations in creep properties obtained appear to correlate with observed microstructures.

Interaction at the silicon/transition metal oxide heterojunction interface and its effect on the photovoltaic performance.

Science.gov (United States)

Liang, Zhimin; Su, Mingze; Zhou, Yangyang; Gong, Li; Zhao, Chuanxi; Chen, Keqiu; Xie, Fangyan; Zhang, Weihong; Chen, Jian; Liu, Pengyi; Xie, Weiguang

2015-11-07

The interfacial reaction and energy level alignment at the Si/transition metal oxide (TMO, including MoO3-x, V2O5-x, WO3-x) heterojunction are systematically investigated. We confirm that the interfacial reaction appears during the thermal deposition of TMO, with the reaction extent increasing from MoO3-x, to V2O5-x, and to WO3-x. The reaction causes the surface oxidation of silicon for faster electron/hole recombination, and the reduction of TMO for effective hole collection. The photovoltaic performance of the Si/TMO heterojunction devices is affected by the interface reaction. MoO3-x are the best hole selecting materials that induce least surface oxidation but strongest reduction. Compared with H-passivation, methyl group passivation is an effective way to reduce the interface reaction and improve the interfacial energy level alignment for better electron and hole collection.

Differential effects of experimental and cold-induced hyperthyroidism on factors inducing rat liver oxidative damage.

Science.gov (United States)

Venditti, P; Pamplona, R; Ayala, V; De Rosa, R; Caldarone, G; Di Meo, S

2006-03-01

Thyroid hormone-induced increase in metabolic rates is often associated with increased oxidative stress. The aim of the present study was to investigate the contribution of iodothyronines to liver oxidative stress in the functional hyperthyroidism elicited by cold, using as models cold-exposed and 3,5,3'-triiodothyronine (T3)- or thyroxine (T4)-treated rats. The hyperthyroid state was always associated with increases in both oxidative capacity and oxidative damage of the tissue. The most extensive damage to lipids and proteins was found in T3-treated and cold-exposed rats, respectively. Increase in oxygen reactive species released by mitochondria and microsomes was found to contribute to tissue oxidative damage, whereas the determination of single antioxidants did not provide information about the possible contribution of a reduced effectiveness of the antioxidant defence system. Indeed, liver oxidative damage in hyperthyroid rats was scarcely related to levels of the liposoluble antioxidants and activities of antioxidant enzymes. Conversely, other biochemical changes, such as the degree of fatty acid unsaturation and hemoprotein content, appeared to predispose hepatic tissue to oxidative damage associated with oxidative challenge elicited by hyperthyroid state. As a whole, our results confirm the idea that T3 plays a key role in metabolic changes and oxidative damage found in cold liver. However, only data concerning changes in glutathione peroxidase activity and mitochondrial protein content favour the idea that dissimilarities in effects of cold exposure and T3 treatment could depend on differences in serum levels of T4.

Effects of some anaesthetics on honeybees: nitrous oxide, carbon dioxide, ammonium nitrate smoker fumes

Energy Technology Data Exchange (ETDEWEB)

Simpson, J

1954-08-01

Honeybees were apparently unaffected by atmospheric oxygen concentrations between 7% and 100%, and only became motionless when the oxygen concentration was less than 2%. The effects of nitrous oxide-oxygen mixtures differed little, if at all, from those nitrogen-oxygen mixtures. Bees were not visibly affected by carbon dioxide concentrations up to 10-15% but they became motionless if the concentration exceeded 40-45%. Fumes produced by adding ammonium nitrate to the fuel in a beekeeper's smoker were found to contain hydrogen cyanide or cyanogen. Their effectiveness as an anaesthetic may be due to this or to some unidentified component, but not to nitrous oxide. All three anaesthetics caused foraging bees to stop collecting pollen, and accelerated the retrogression of the pharyngeal glands of young bees. Anaesthesia of a few bees in a colony with nitrous oxide, carbon dioxide, or ammonium nitrate smoker fumes did not appear to inhibit their drift back to the original site when their hive was moved, nor was any reduction in drifting observed when a whole colony was moved while anaesthetized with ammonium nitrate smoker fumes. 4 tables.

Effects Of Combinations Of Patternmaking Methods And Dress Forms On Garment Appearance

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Fujii Chinami

2017-09-01

Full Text Available We investigated the effects of the combinations of patternmaking methods and dress forms on the appearance of a garment. Six upper garments were made using three patternmaking methods used in France, Italy, and Japan, and two dress forms made in Japan and France. The patterns and the appearances of the garments were compared using geometrical measurements. Sensory evaluations of the differences in garment appearance and fit on each dress form were also carried out. In the patterns, the positions of bust and waist darts were different. The waist dart length, bust dart length, and positions of the bust top were different depending on the patternmaking method, even when the same dress form was used. This was a result of differences in the measurements used and the calculation methods employed for other dimensions. This was because the ideal body shape was different for each patternmaking method. Even for garments produced for the same dress form, the appearances of the shoulder, bust, and waist from the front, side, and back views were different depending on the patternmaking method. As a result of the sensory evaluation, it was also found that the bust and waist shapes of the garments were different depending on the combination of patternmaking method and dress form. Therefore, to obtain a garment with better appearance, it is necessary to understand the effects of the combinations of patternmaking methods and body shapes.

Properties of Polydisperse Tin-doped Dysprosium and Indium Oxides

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Malinovskaya Tatyana

2017-01-01

Full Text Available The results of investigations of the complex permittivity, diffuse-reflectance, and characteristics of crystal lattices of tin-doped indium and dysprosium oxides are presented. Using the methods of spectroscopy and X-ray diffraction analysis, it is shown that doping of indium oxide with tin results in a significant increase of the components of the indium oxide complex permittivity and an appearance of the plasma resonance in its diffuse-reflectance spectra. This indicates the appearance of charge carriers with the concentration of more than 1021 cm−3 in the materials. On the other hand, doping of the dysprosium oxide with the same amount of tin has no effect on its optical and electromagnetic properties.

Effect of oxygen deficiency on electronic properties and local structure of amorphous tantalum oxide thin films

Energy Technology Data Exchange (ETDEWEB)

Denny, Yus Rama [Department of Physics Education, University of Sultan Ageng Tirtayasa, Banten 42435 (Indonesia); Firmansyah, Teguh [Department of Electrical Engineering, University of Sultan Ageng Tirtayasa, Banten 42435 (Indonesia); Oh, Suhk Kun [Department of Physics, Chungbuk National University, Cheongju 28644 (Korea, Republic of); Kang, Hee Jae, E-mail: hjkang@cbu.ac.kr [Department of Physics, Chungbuk National University, Cheongju 28644 (Korea, Republic of); Yang, Dong-Seok [Department of Physics Education, Chungbuk National University, Cheongju 28644 (Korea, Republic of); Heo, Sung; Chung, JaeGwan; Lee, Jae Cheol [Analytical Engineering Center, Samsung Advanced Institute of Technology, Suwon 16678 (Korea, Republic of)

2016-10-15

Highlights: • The effect of oxygen flow rate on electronic properties and local structure of tantalum oxide thin films was studied. • The oxygen deficiency induced the nonstoichiometric state a-TaOx. • A small peak at 1.97 eV above the valence band side appeared on nonstoichiometric Ta{sub 2}O{sub 5} thin films. • The oxygen flow rate can change the local electronic structure of tantalum oxide thin films. - Abstract: The dependence of electronic properties and local structure of tantalum oxide thin film on oxygen deficiency have been investigated by means of X-ray photoelectron spectroscopy (XPS), Reflection Electron Energy Loss Spectroscopy (REELS), and X-ray absorption spectroscopy (XAS). The XPS results showed that the oxygen flow rate change results in the appearance of features in the Ta 4f at the binding energies of 23.2 eV, 24.4 eV, 25.8, and 27.3 eV whose peaks are attributed to Ta{sup 1+}, Ta{sup 2+}, Ta{sup 3+}/Ta{sup 4+}, and Ta{sup 5+}, respectively. The presence of nonstoichiometric state from tantalum oxide (TaOx) thin films could be generated by the oxygen vacancies. In addition, XAS spectra manifested both the increase of coordination number of the first Ta-O shell and a considerable reduction of the Ta-O bond distance with the decrease of oxygen deficiency.

Effects of exposure to information about appearance stereotyping and discrimination on women's body images.

Science.gov (United States)

Lavin, M A; Cash, T F

2001-01-01

There is widespread public dissemination of research findings and media messages regarding social advantages of physical attractiveness and liabilities of unattractiveness. The purpose of this experimental study was to determine the effects of such information on women's body-image experiences. College women (n = 66) listened to one of two audiotapes that detailed research-based information either on the subject of appearance stereotyping and discrimination or on the control topic of television violence and aggression. Although the two conditions did not differentially alter mood, exposure to appearance-related versus control information produced significantly less favorable body-image evaluations. Furthermore, as predicted, women who were schematically invested in their physical appearance were especially susceptible to the deleterious effects of the appearance information. The scientific and clinical implications of these findings were discussed, particularly with respect to eating disturbances.

Nivalenol induces oxidative stress and increases deoxynivalenol pro-oxidant effect in intestinal epithelial cells

Energy Technology Data Exchange (ETDEWEB)

Del Regno, Marisanta; Adesso, Simona; Popolo, Ada [Department of Pharmacy, School of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132–84084 Fisciano, Salerno (Italy); Quaroni, Andrea [Department of Biomedical Sciences, Cornell University, Veterinary Research Tower, Cornell University, Ithaca, NY 14853–6401 (United States); Autore, Giuseppina [Department of Pharmacy, School of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132–84084 Fisciano, Salerno (Italy); Severino, Lorella [Department of Pathology and Animal Health, Division of Toxicology, School of Veterinary Medicine, University of Naples “Federico II”, Via Delpino 1, 80137 Naples (Italy); Marzocco, Stefania, E-mail: smarzocco@unisa.it [Department of Pharmacy, School of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132–84084 Fisciano, Salerno (Italy)

2015-06-01

Mycotoxins are secondary fungal metabolites often found as contaminants in almost all agricultural commodities worldwide, and the consumption of food or feed contaminated by mycotoxins represents a major risk for human and animal health. Reactive oxygen species are normal products of cellular metabolism. However, disproportionate generation of reactive oxygen species poses a serious problem to bodily homeostasis and causes oxidative tissue damage. In this study we analyzed the effect of two trichothecenes mycotoxins: nivalenol and deoxynivalenol, alone and in combination, on oxidative stress in the non-tumorigenic intestinal epithelial cell line IEC-6. Our results indicate the pro-oxidant nivalenol effect in IEC-6, the stronger pro-oxidant effect of nivalenol when compared to deoxynivalenol and, interestingly, that nivalenol increases deoxynivalenol pro-oxidative effects. Mechanistic studies indicate that the observed effects were mediated by NADPH oxidase, calcium homeostasis alteration, NF-kB and Nrf2 pathways activation and by iNOS and nitrotyrosine formation. The toxicological interaction by nivalenol and deoxynivalenol reported in this study in IEC-6, points out the importance of the toxic effect of these mycotoxins, mostly in combination, further highlighting the risk assessment process of these toxins that are of growing concern. - Highlights: • Nivalenol induces oxidative stress in intestinal epithelial cells (IECs). • Nivalenol increases deoxynivalenol pro-oxidant effects in IECs. • Nivalenol and deoxynivalenol trigger antioxidant response IECs. • These results indicate the importance of mycotoxins co-contamination.

Pre-exposure to nitric oxide modulates the effect of ozone on oxidative defenses and volatile emissions in lima bean

International Nuclear Information System (INIS)

Souza, Silvia R.; Blande, James D.; Holopainen, Jarmo K.

2013-01-01

The roles that ozone and nitric oxide (NO), the chief O 3 precursor, play in the antioxidative balance and inducible volatile emissions of lima bean were assessed. Exposure to O 3 inhibited APX, CAT, and GR, decreased GSH content and induced emissions of (E)-β-ocimene, limonene, 1,8-cineole, linalool, (E)-4,8-dimethyl-1,3,7-nonatriene (E)-DMNT, 2-butanone and nonanal. O 3 did not induce emissions of (E)-β-caryophyllene and appeared to reduce the antioxidative capacity of plants to a greater extent than NO and NO followed by O 3 (NO/O 3 ) treatments. There were significant differences in emissions of (E)-β-ocimene and linalool between NO/O 3 treated plants and controls, but no differences in antioxidant concentrations. A model to explain the relationships between the ascorbate–glutathione cycle and O 3 and NO inducible volatiles was proposed. Our findings suggest that prior exposure to NO modulates the oxidative effect of ozone by the process of cross-tolerance, which might regulate the antioxidative system and induction of volatile organic compounds. -- Highlights: •NO and O 3 disturb antioxidant defenses and cause lipid peroxidation in lima bean plants. •Exposure to NO before exposure to O 3 does not alter the antioxidant defenses and malondialdehyde levels. •The total sum of induced volatiles is reduced in plants that are exposed to NO and then O 3 . •The antioxidant system and induced VOC emission were balanced by pre-exposure to NO before O 3 . -- Capsule: Nitric oxide modulates the ozone-induced oxidative stress in lima bean by cross-tolerance effect

Color appearance of familiar objects: effects of object shape, texture, and illumination changes.

Science.gov (United States)

Olkkonen, Maria; Hansen, Thorsten; Gegenfurtner, Karl R

2008-05-26

People perceive roughly constant surface colors despite large changes in illumination. The familiarity of colors of some natural objects might help achieve this feat through direct modulation of the objects' color appearance. Research on memory colors and color appearance has yielded controversial results and due to the employed methods has often confounded perceptual with semantic effects. We studied the effect of memory colors on color appearance by presenting photographs of fruit on a monitor under various simulated illuminations and by asking observers to make either achromatic or typical color settings without placing demands on short-term memory or semantic processing. In a control condition, we presented photographs of 3D fruit shapes without texture and 2D outline shapes. We found that (1) achromatic settings for fruit were systematically biased away from the gray point toward the opposite direction of a fruit's memory color; (2) the strength of the effect depended on the degree of naturalness of the stimuli; and (3) the effect was evident under all tested illuminations, being strongest for illuminations whose chromaticity was closest to the stimulus chromaticity. We conclude that the visual identity of an object has a measurable effect on color perception, and that this effect is robust under illuminant changes, indicating its potential significance as an additional mechanism for color constancy.

Effect of I125 on oxidation behavior of lipoprotein subpopulations

International Nuclear Information System (INIS)

Majtenyi, S.

2002-07-01

Lipoproteins play a central role in lipid metabolism. They serve as a transport vehicle for cholesterol and triglycerides keeping them in plasma in solution. Lipoproteins are characterized by the content of specific apoproteins and differences in the hydrated density ranges. Moreover, they are distinguished by electrophoretic mobility and other characteristics as high and low-density lipoproteins, respectively lipoprotein (a). More specifically, HDL is classified into HDL 2 and HDL 3 . In atherogenesis, lipoproteins are considered to play a key-role. Oxidatively modified LDL is selectively taken up via scavenger receptors of the macrophage-monocyte system. These cells are transformed into foam cells promoting atherogenesis in vessels in the subendothelial space. Oxidized HDL essentially appears to loose its protective effects on LDL and its beneficial function in reverse cholesterol transport. Thus, it turns proatherogenic. The effects various species of free radicals exert on lipoproteins are the reason for this oxidative modification. Thyroid function also influences lipoproteins in a complex manner. Based on their hydrated density ranges, lipoprotein subpopulations were fractionated and isolated via isopycnic density gradient ultracentrifugation. After investigation of the general oxidation behavior, initiated by addition of CuSO 4 to the isolated samples of HDL 3 , HDL 2 , LDL and Lp(a), the influence of different activities of radioiodine-125 on the kinetics of the formation of conjugated dienes was assessed. This was achieved by coincubation of plasma with I 125 . The spectrophotometrical measurement of the concentration of conjugated dienes in the course of CuSO 4 -induced lipid peroxidation leads to measurable changes in absorption at 234 nm. These changes in absorption over time result in a characteristically shaped curve graphically plotted. The shape of these curves mirrors different indicators of lipid peroxidation. Therefrom lag time, maximal

Mixed Pro- and Anti-Oxidative Effects of Pomegranate Polyphenols in Cultured Cells

Science.gov (United States)

Danesi, Francesca; Kroon, Paul A.; Saha, Shikha; de Biase, Dario; D’Antuono, Luigi Filippo; Bordoni, Alessandra

2014-01-01

In recent years, the number of scientific papers concerning pomegranate (Punica granatum L.) and its health properties has increased greatly, and there is great potential for the use of bioactive-rich pomegranate extracts as ingredients in functional foods and nutraceuticals. To translate this potential into effective strategies it is essential to further elucidate the mechanisms of the reported bioactivity. In this study HepG2 cells were supplemented with a pomegranate fruit extract or with the corresponding amount of pure punicalagin, and then subjected to an exogenous oxidative stress. Overall, upon the oxidative stress the gene expression and activity of the main antioxidant enzymes appeared reduced in supplemented cells, which were more prone to the detrimental effects than unsupplemented ones. No differences were detected between cells supplemented with the pomegranate juice or the pure punicalagin. Although further studies are needed due to the gaps existing between in vitro and in vivo studies, our results suggest caution in the administration of high concentrations of nutraceutical molecules, particularly when they are administered in concentrated form. PMID:25350111

Strengthening effect of reduced graphene oxide in steel clad copper rod

Science.gov (United States)

Gao, Haitao; Liu, Xianghua; Ai, Zhengrong; Zhang, Shilong; Liu, Lizhong

2016-11-01

Reduced graphene oxide has been extensively used as reinforcing agent owing to their high mechanical properties. In this work, an attempt is made to synthesize steel clad copper rod reinforced with reduced graphene oxide (RGO) by the combination of powder-in-tube and intermediate annealing (IA). Experiments show that the Fe/RGO/Cu composites manifest better mechanical properties than Fe/Cu composites. In the process of groove rolling, RGO acts as effective binder, which can greatly improve the adhesive strength of copper scrap and two metals. Moreover, the strengthening effect of RGO is tightly related to its dispersion state. The RGO diffuses much more uniformly on the metallic substrate under the IA temperature of 1100 °C than 800 °C, which can be characterized by less deformation twins appearing at the interface of core copper and the formation of Fe-RGO-Cu transition belt at the bonding interface. In this case, the peak hardness, tensile strength and shear strength of Fe/RGO/Cu composites are 52 HV, 125 and 41 MPa higher than those of the Fe/Cu composites, respectively. The difference of strengthening effect and mechanisms of RGO under 800 and 1100 °C of IA are systematically discussed by referring to experimental results.

Effect of the Lithium Oxide Concentration on a Reduction of Lanthanide Oxides

International Nuclear Information System (INIS)

Choi, In-Kyu; Jeong, Myeong-Soo; Do, Jae-Bum; Seo, Chung-Seok

2007-01-01

The pyrochemical reduction process of spent oxide fuel is one of the options to handle spent PWR fuels in Korea. After spent oxide fuel is converted to a metallic form, fission products will be removed from the resultant uranium and higher actinide metals by an electrorefining process. The chemical behaviors of lanthanide oxides during the pyrochemical process has been extensively studied. It was also reported that about 30 to 50% of several lanthanide oxides were reduced to corresponding metals by an electrolytic reduction process having 1 wt% of a lithium oxide concentration. Korea Atomic Energy Research Institute (KAERI), however, has been used 3 wt% of lithium oxide to increase the applied current of the electrolytic reduction process. Though it was reported that U 3 O 8 was reduced to uranium metal having a high reduction yield at 3 wt% of the Li 2 O concentration, the effect of the lithium oxide concentration on the reduction of lanthanide oxides has not been clarified

La doping effect on TZM alloy oxidation behavior

International Nuclear Information System (INIS)

Yang, Fan; Wang, Kuai-She; Hu, Ping; He, Huan-Cheng; Kang, Xuan-Qi; Wang, Hua; Liu, Ren-Zhi; Volinsky, Alex A.

2014-01-01

Highlights: • The oxidation can be resisted by doping La into TZM alloy. • La doped TZM alloy has more compact organization. • It can rise the starting temperature of severe oxidation reaction by more than 50 °C. • Effectively slow down the oxidation rate. • Provide guidance for experiments of improving high-temperature oxidation resistance. - Abstract: Powder metallurgy methods were utilized to prepare lanthanum-doped (La-TZM) and traditional TZM alloy plates. High temperature oxidation experiments along with the differential thermal analysis were employed to study the oxidation behavior of the two kinds of TZM alloys. An extremely volatile oxide layer was generated on the surface of traditional TZM alloy plates when the oxidation started. Molybdenum oxide volatilization exposed the alloy matrix, which was gradually corroded by oxygen, losing its quality with serious surface degradation. The La-TZM alloy has a more compact structure due to the lanthanum doping. The minute lanthanum oxide particles are pinned at the grain boundaries and refine the grains. Oxide layer generated on the matrix surface can form a compact coating, which effectively blocks the surface from being corroded by oxidation. The oxidation resistance of La-TZM alloys has been enhanced, expanding its application range

Lipid oxidation in fish oil enriched mayonnaise : Calcium disodium ethylenediaminetetraacetate, but not gallic acid, strongly inhibited oxidative deterioration

DEFF Research Database (Denmark)

Jacobsen, Charlotte; Hartvigsen, Karsten; Thomsen, Mikael Holm

2001-01-01

The antioxidative effects of gallic acid, EDTA, and extra emulsifier Panodan DATEM TR in mayonnaise enriched with 16% fish oil were investigated. EDTA reduced the formation of free radicals, lipid hydroperoxides, volatiles, and fishy and rancid off-flavors. The antioxidative effect of EDTA...... acid may therefore promote the decomposition of lipid hydroperoxides to volatile oxidation products. Addition of extra emulsifier reduced the lipid hydroperoxide levels but did not influence the level of free radicals or the oxidative flavor deterioration in mayonnaisse; however, it appeared to alter...

The mediating effect of self-esteem, depression and anxiety between satisfaction with body appearance and problematic internet use.

Science.gov (United States)

Koronczai, Beatrix; Kökönyei, Gyöngyi; Urbán, Róbert; Kun, Bernadette; Pápay, Orsolya; Nagygyörgy, Katalin; Griffiths, Mark D; Demetrovics, Zsolt

2013-07-01

Given that dissatisfaction with bodily appearance can sometimes lead to the avoidance of personal contacts and the increase of internet use, this study examines this relationship. The direct role of dissatisfaction with bodily appearance along with the possible mediation effects of depression, anxiety and self-esteem were tested. A total of 694 participants completed an online questionnaire (58.5% male, mean age 21.5 years), containing measures on problematic internet use, depression and anxiety symptoms, self-esteem and satisfaction with body image. Path analyses were used to test direct and indirect effects. Satisfaction with body appearance had a significant negative direct effect on problematic internet use among both sexes. Though, satisfaction with body appearance had a positive effect on self-esteem and negative on anxiety, neither self-esteem nor anxiety had a direct significant effect on problematic internet use. The effect of dissatisfaction with body appearance was mediated via the self-esteem-depression path toward problematic internet use. Dissatisfaction with physical appearance seems to have a significant role in individuals' immersing themselves in internet use.

Health Effects Associated With Exposure to Anesthetic Gas Nitrous Oxide-N2O in Clinical Hospital - Shtip Personel.

Science.gov (United States)

Eftimova, Bilijana; Sholjakova, Marija; Mirakovski, Dejan; Hadzi-Nikolova, Marija

2017-10-15

To show certain health effects associated with acute and chronic exposure to nitrous oxide of staff of the Department of Anaesthesiology and Intensive Care at the Clinical Hospital in Shtip. A transversal study was conducted, that include 43 health workers (23 - exposed and 20 - unexposed). Personal exposure to nitrous oxide for this group members was assessed through continuous measurement over 8 hours shift within breathing zone of the subjects involved, using handheld electrochemical instrument with datalogging option direct. In order to determine presence of possible health effects associated with acute and chronic exposure to nitrous oxide in ORs and ICUs, a specially designed questionnaire was prepared and distributed to be anonymously filled out, by all the examinees from both examined groups. Data were statistically tested for normality and also quantitative and qualitative assessment was performed. From the results obtained, a significant difference in several health effects between exposed and unexposed groups can be noted, including headaches, dizziness, nausea and vomiting, euphoria and tachycardia. Regarding the excitement, the appearance of depression, the feeling of numbness and tingling of the hands and feet, the differences between the two examined groups were not significant. It can be concluded that chronic exposure to nitrous oxide is associated with the adverse health effects.

Effect of the pre-transient oxide on Zy-4 cladding degradation in air and air+steam atmospheres

International Nuclear Information System (INIS)

Duriez, C.; Guerain, M.; Lacote, P.; Mermoux, M.

2015-01-01

High temperature reactivity in air of Zr based alloys has been mostly investigated with initially bare cladding materials. In this study, attention is paid to the influence of a low temperature pre-oxidation scale aiming to simulate the corrosion scale existing on spent fuel. Different out of pile pre-oxidation methods, inducing significant variation in the pre-oxides microstructure, are compared. The reaction kinetics in air and in mixed air + steam atmospheres, investigated in the 700-950 C. degrees temperature range by thermogravimetry (TGA), shows that a pre-oxide scale formed at low temperature has a protective effect at high temperature by significantly delaying occurrence of the kinetic acceleration, which however still occurs. Efficiency of this protective effect appears to depend on the type of pre-oxide. To better understand the exact role of the pre-oxide, oxygen transport through the pre-oxide has been investigated using the 18 O tracer technique. 18 O distribution maps have been obtained by micro-Raman imaging, which has proved to offer interesting capabilities for that purpose. Results obtained with a 30 μm pre-oxide scale formed at 425 C. degrees in oxygen suggest that, at 850 C. degrees, only the inner part of the scale acts as a barrier against oxidation while the outermost part of the scale (5 to 15 μm in thickness) seems to be permeable to gaseous oxygen. The use of the 18 O isotope tracer technique associated with micro-Raman mapping of the scales is demonstrated to be a powerful method to investigate the transport properties of the scales and will help to gain understanding of the kinetic differences between the different pre-oxides

The effect of gamma-ray and ethylene oxide sterilization on collagen-based wound-repair materials

International Nuclear Information System (INIS)

Gorham, S.D.; Scott, R.

1993-01-01

The effects of 2.5, 5.0, 7.5 and 10 Mrad gamma-irradiation and ethylene oxide sterilization on collagen-coated vicryl mesh, on collagen film and vicryl mesh were investigated. No cytotoxic effects were observed towards either L929 cells or human fibroblasts with any of the treatments, even at the highest doses of irradiation. Although the rate of biodegradation and tissue reaction towards the test materials appeared to be relatively unaffected by ethylene oxide, the rate of breakdown in the lumbar muscles of laboratory rats was considerably increased by irradiation. Dose-dependent irradiation damage to the vicryl mesh was confirmed in vitro using viscometry and by an increase in the rate of hydrolysis in phosphate-buffered saline (PBS) at 37 o C. Tensiometric studies on irradiated collagen films showed a dose-dependent reduction in both the break load and elongation before breaking. A small reduction in the break load and stretch to breaking was also observed following treatment with ethylene oxide. The findings presented favour ethylene oxide as a method of sterilization of both the composite membrane and its individual components. However, gamma-irradiation produced no toxic effects or adverse tissue reaction under the conditions described, and is more convenient to use. Hence, provided that the efficacy of the membrane would not be compromised by the higher rate of degradation, it could also be considered for sterilization of the material. (author)

Effect of yttrium on the oxide scale adherence of pre-oxidized silicon-containing heat-resistant alloy

International Nuclear Information System (INIS)

Yan Jingbo; Gao Yimin; Shen Yudi; Yang Fang; Yi Dawei; Ye Zhaozhong; Liang Long; Du Yingqian

2011-01-01

Highlights: → AE experiment shows yttrium has a beneficial effect on the pre-oxidized HP40 alloy. → Yttrium facilitates the formation of internal oxide after 10 h of oxidation. → Internal oxide changes the rupture behaviour of the oxide scale. → Twins form in the internal oxide and improve the binding strength of the scale. - Abstract: This paper investigates the effect of the rare earth element yttrium on the rupture behaviour of the oxide scale on the silicon-containing heat-resistant alloy during cooling. After 10 h of oxidation, yttrium is found to facilitate the formation of internal oxides (silica) at the scale-matrix interface. Due to the twinning observed by scanning transmission electron microscopy (STEM) in silica, the critical strain value for the scale failure can be dramatically improved, and the formation of cracks at the scale-matrix interface is inhibited.

Involvement of nitric oxide in anticompulsive-like effect of agmatine on marble-burying behaviour in mice.

Science.gov (United States)

Gawali, Nitin B; Chowdhury, Amrita A; Kothavade, Pankaj S; Bulani, Vipin D; Nagmoti, Dnyaneshwar M; Juvekar, Archana R

2016-01-05

In view of the reports that nitric oxide modulates the neurotransmitters implicated in obsessive-compulsive disorder (OCD), patients with OCD exhibit higher plasma nitrate levels, and drugs useful in OCD influence nitric oxide. Agmatine is a polyamine and widely distributed in mammalian brain which interacts with nitrergic systems. Hence, the present study was carried out to understand the involvement of nitrergic systems in the anticompulsive-like effect of agmatine. We used marble-burying behaviour (MBB) of mice as the animal model of OCD, and nitric oxide levels in hippocampus (HC) and cortex homogenate were measured. Results revealed that, agmatine (20 and 40mg/kg, i.p) significantly inhibited the MBB. Intraperitoneal administration of nitric oxide enhancers viz. nitric oxide precursor - l-arginine (l-ARG) (400mg/kg and 800mg/kg) increased MBB as well as brain nitrites levels, whereas treatment with N(G)-nitro-l-arginine methyl ester (l-NAME) neuronal nitric oxide synthase inhibitor (30mg/kg and 50mg/kg, i.p.) and 7-nitroindazole (7-NI) (20mg/kg and 40mg/kg) attenuated MBB and nitrites levels in brain. Further, in combination studies, the anticompulsive-like effect of agmatine (20mg/kg, ip) was exacerbated by prior administration of l-ARG (400mg/kg) and conversely l-NAME (15mg/kg) or 7-NI (10.0mg/kg) attenuated OCD-like behaviour with HC and cortex changes in the levels of NO. None of the above treatment had any significant influence on locomotor activity. In conclusion, Agmatine is effective in ameliorating the compulsive-like behaviour in mice which appears to be related to nitric oxide in brain. Copyright © 2015 Elsevier B.V. All rights reserved.

Corrosion mechanisms of zirconium alloys - study of the initial oxidation kinetics and of the mechanical behaviour of the metal/oxide system

International Nuclear Information System (INIS)

Parise, M.

1996-12-01

Nuclear fuel claddings are made of zirconium alloys. The conditions of use lead the cladding oxidize outside. The so-formed layers behaves like a thermal barrier and prevents from using oxidized claddings with an oxide thickness larger than 100 μm. The oxidation kinetic is approximately cubic for oxide thicknesses smaller than about 2μm, linear beyond. A kinetic model has been proposed which estimates the post-transition growth rate from the kinetic parameters of the pre-transition state and morphological features of post-transition layers. This work aims at providing the necessary elements to validate this model and studying the layers around the kinetic transition, in order to determine whether the oxidation mechanisms before and after the transition are similar. Thicknesses of the 50 - 500 nm range of the oxide layers are measured by an optical method; pre-transition kinetics are thus precisely determined. The effect of the composition, the thermal treatment and the presence of oxygen in solid solution is studied. The morphological and crystallographic study of the layers show that they exhibit a lot of similarities before and after the kinetic transition. The results concerning the kinetic aspects and the morphology of the post-transition layers point out that the proposed model leads to realistic post-transition growth rates. Furthermore, the kinetic transition corresponds to the appearance of cracks in the oxide layer. The mechanical behaviour of the metal/oxide system has been modelled at different scales. When the specific behaviours of the metal and the oxide are taken into account together with the interface geometry, radial stresses appear, which are high enough to locally open cracks. The appearance and localization of cracks depend on both the interface geometry and the stress distribution in the metal/oxide system. (author)

Evolution, Appearance, and Occupational Success

Directory of Open Access Journals (Sweden)

Anthony C. Little

2012-12-01

Full Text Available Visual characteristics, including facial appearance, are thought to play an important role in a variety of judgments and decisions that have real occupational outcomes in many settings. Indeed, there is growing evidence suggesting that appearance influences hiring decisions and even election results. For example, attractive individuals are more likely to be hired, taller men earn more, and the facial appearance of candidates has been linked to real election outcomes. In this article, we review evidence linking physical appearance to occupational success and evaluate the hypothesis that appearance based biases are consistent with predictions based on evolutionary theories of coalition formation and leadership choice. We discuss why appearance based effects are so pervasive, addressing ideas about a “kernel of truth” in attributions and about coalitional psychology. We additionally highlight that appearance may be differently related to success at work according to the types of job or task involved. For example, leaders may be chosen because the characteristics they possess are seen as best suited to lead in particular situations. During a time of war, a dominant-appearing leader may inspire confidence and intimidate enemies while during peace-time, when negotiation and diplomacy are needed, interpersonal skills may outweigh the value of a dominant leader. In line with these ideas, masculine-faced leaders are favored in war-time scenarios while feminine-faced leaders are favored in peace-time scenarios. We suggest that such environment or task specific competencies may be prevalent during selection processes, whereby individuals whose appearance best matches perceived task competences are most likely selected, and propose the general term “task-congruent selection” to describe these effects. Overall, our review highlights how potentially adaptive biases could influence choices in the work place. With respect to certain biases

Effect of post oxidation anneal on VUV radiation-hardness of the Si/SiO2 system studied by positron annihilation spectroscopy

International Nuclear Information System (INIS)

Clement, M.; Nijs, J.M.M. de; Veen, A. van; Schut, H.; Balk, P.

1995-01-01

The effect of a post oxidation anneal at 1,000 C in a N 2 ambient of the thermally grown Si/SiO 2 system was investigated using vacuum ultraviolet irradiation for determining the generation of interface traps of the Al metallized system in combination with positron annihilation spectroscopy to characterize the structure of the oxide network. A correlation was found between the generation of interface traps and the S parameter of the positron trapping sites in the oxide close to the Si. It appears likely that the positrons are trapped in the larger near-interfacial oxide network interstices. These interstices could act as scavengers for the metastable intermediate (atomic hydrogen or excitons) involved in the generation of the interface traps

Effect of turmeric and curcumin on oxidative stress and antioxidant enzymes in streptozotocin-induced diabetic rat.

Science.gov (United States)

Suryanarayana, Palla; Satyanarayana, Alleboena; Balakrishna, Nagalla; Kumar, Putcha Uday; Reddy, Geereddy Bhanuprakash

2007-12-01

There is increasing evidence that complications related to diabetes are associated with increased oxidative stress. Curcumin, an active principle of turmeric, has several biological properties, including antioxidant activity. The protective effect of curcumin and turmeric on streptozotocin (STZ)-induced oxidative stress in various tissues of rats was studied. Three-month-old Wistar-NIN rats were made diabetic by injecting STZ (35 mg/kg body weight) intraperitoneally and fed either only the AIN-93 diet or the AIN-93 diet containing 0.002% or 0.01% curcumin or 0.5% turmeric for a period of eight weeks. After eight weeks the levels of oxidative stress parameters and activity of antioxidant enzymes were determined in various tissues. STZ-induced hyperglycemia resulted in increased lipid peroxidation and protein carbonyls in red blood cells and other tissues and altered antioxidant enzyme activities. Interestingly, feeding curcumin and turmeric to the diabetic rats controlled oxidative stress by inhibiting the increase in TBARS and protein carbonyls and reversing altered antioxidant enzyme activities without altering the hyperglycemic state in most of the tissues. Turmeric and curcumin appear to be beneficial in preventing diabetes-induced oxidative stress in rats despite unaltered hyperglycemic status.

Postponed effect of neostigmine on oxidative homeostasis

Directory of Open Access Journals (Sweden)

Pohanka Miroslav

2014-09-01

Full Text Available Cholinesterases are enzymes able to hydrolyze the neurotransmitter acetylcholine and thus to terminate transmission. Once the enzymes are inhibited, excitotoxicity can appear in the adjacent cells. It is well known that oxidative stress is involved in the toxicity of cholinesterase inhibitors. Commonly, stress follows inhibition of cholinesterases and disappears shortly afterwards. In the present experiment, it was decided to test the impact of an inhibitor, neostigmine, on oxidative stress in BALB/c mice after a longer interval. The animals were sacrificed three days after onset of the experiment and spleens and livers were collected. Reduced glutathione (GSH, glutathione reductase (GR, glutathione S-transferase (GST, thiobarbituric acid reactive substances (TBARS, ferric reducing antioxidant power (FRAP, caspase-3 and activity of acetylcholinesterase (AChE were assayed. The tested markers were not altered with exceptions of FRAP. The FRAP values indicate accumulation of low molecular weight antioxidants in the examined organs. The role of low molecular weight antioxidants in the toxicity of AChE inhibitors is discussed.

Anodization and Optical Appearance of Sputter Deposited Al-Zr Coatings

DEFF Research Database (Denmark)

Gudla, Visweswara Chakravarthy; Canulescu, Stela; Shabadi, Rajashekhara

2014-01-01

of the anodized layer. The microstructure of the coating is found to influence the appearance of anodized layer owing to the presence of completely or partially dissolved second phases during anodizing process. Oxidation status of the second phase particles in the coatings affected the light absorption......Anodized Al alloy components are extensively used in various applications like architectural, decorative and automobiles for corrosion protection and/or decorative optical appearance. However, tailoring the anodized layer for specific optical appearance is limited due to variation in composition...... and microstructure of the commercial alloys, and even more difficult with recycled alloys. Sputter coating methods promise to control the chemical composition of the Al alloy surfaces and eventually modify the microstructure of the surfaces with heat treatments thus enabling the freedom on the substrate quality...

Appearance of anodised aluminium: Effect of alloy composition and prior surface finish

DEFF Research Database (Denmark)

Aggerbeck, Martin; Canulescu, Stela; Dirscherl, Kai

2014-01-01

Effect of alloy composition and prior surface finish on the optical appearance of the anodised layer on aluminium alloys was investigated. Four commercial alloys namely AA1050, Peraluman 706, AA5754, and AA6082 were used for the investigation. Microstructure and surface morphology of the substrat...

Effects of trace volatile organic compounds on methane oxidation

Directory of Open Access Journals (Sweden)

Chiemchaisri Wilai

2001-01-01

Full Text Available The effects of volatile organic compounds (VOCs on methane oxidation in landfill cover soils were examined. The batch experiments were conducted using single and mixed VOCs, such as, dichloromethane (DCM, trichloroethylene (TCE, tetrachloroethylene (PCE, and benzene. The results from all combinations showed a decrease in methane oxidation rate with increase in VOC concentrations. Moreover, inhibition effects of TCE and DCM were found higher than benzene and PCE. The reduction of methane oxidation by benzene and PCE could be attributed to the toxicity effect, whereas TCE and DCM were found to exhibit the competitive-inhibition effect. When the soil was mixed with DCM, no methane oxidation was found. Damage to the cell's internal membrane was found in a methanotrophic culture exposed to VOC gases which is the attachment site of a key enzyme needed for methane oxidation

Memory and disgust: Effects of appearance-congruent and appearance-incongruent information on source memory for food.

Science.gov (United States)

Mieth, Laura; Bell, Raoul; Buchner, Axel

2016-01-01

The present study was stimulated by previous findings showing that people preferentially remember person descriptions that violate appearance-based first impressions. Given that until now all studies used faces as stimuli, these findings can be explained by referring to a content-specific module for social information processing that facilitates social orientation within groups via stereotyping and counter-stereotyping. The present study tests whether the same results can be obtained with fitness-relevant stimuli from another domain--pictures of disgusting-looking or tasty-looking food, paired with tasty and disgusting descriptions. A multinomial model was used to disentangle item memory, guessing and source memory. There was an old-new recognition advantage for disgusting-looking food. People had a strong tendency towards guessing that disgusting-looking food had been previously associated with a disgusting description. Source memory was enhanced for descriptions that disconfirmed these negative, appearance-based impressions. These findings parallel the results from the social domain. Heuristic processing of stimuli based on visual appearance may be complemented by intensified processing of incongruent information that invalidates these first impressions.

Effect of electrolyte temperature on the formation of self-organized anodic niobium oxide microcones in hot phosphate-glycerol electrolyte

Science.gov (United States)

Yang, S.; Aoki, Y.; Habazaki, H.

2011-07-01

Nanoporous niobium oxide films with microcone-type surface morphology were formed by anodizing at 10 V in glycerol electrolyte containing 0.6 mol dm -3 K 2HPO 4 and 0.2 mol dm -3 K 3PO 4 in a temperature range of 428-453 K. The microcones appeared after prolonged anodizing, but the required time was largely reduced by increasing electrolyte temperature. The anodic oxide was initially amorphous at all temperatures, but crystalline oxide nucleated during anodizing. The anodic oxide microcones, which were crystalline, appeared on surface as a consequence of preferential chemical dissolution of initially formed amorphous oxide. The chemical dissolution of an initially formed amorphous layer was accelerated by increasing the electrolyte temperature, with negligible influence of the temperature on the morphology of microcones up to 448 K.

Oxidative Metabolism Genes Are Not Responsive to Oxidative Stress in Rodent Beta Cell Lines

Directory of Open Access Journals (Sweden)

Faer Morrison

2012-01-01

Full Text Available Altered expression of oxidative metabolism genes has been described in the skeletal muscle of individuals with type 2 diabetes. Pancreatic beta cells contain low levels of antioxidant enzymes and are particularly susceptible to oxidative stress. In this study, we explored the effect of hyperglycemia-induced oxidative stress on a panel of oxidative metabolism genes in a rodent beta cell line. We exposed INS-1 rodent beta cells to low (5.6 mmol/L, ambient (11 mmol/L, and high (28 mmol/L glucose conditions for 48 hours. Increases in oxidative stress were measured using the fluorescent probe dihydrorhodamine 123. We then measured the expression levels of a panel of 90 oxidative metabolism genes by real-time PCR. Elevated reactive oxygen species (ROS production was evident in INS-1 cells after 48 hours (P<0.05. TLDA analysis revealed a significant (P<0.05 upregulation of 16 of the 90 genes under hyperglycemic conditions, although these expression differences did not reflect differences in ROS. We conclude that although altered glycemia may influence the expression of some oxidative metabolism genes, this effect is probably not mediated by increased ROS production. The alterations to the expression of oxidative metabolism genes previously observed in human diabetic skeletal muscle do not appear to be mirrored in rodent pancreatic beta cells.

Graphene-graphite oxide field-effect transistors.

Science.gov (United States)

Standley, Brian; Mendez, Anthony; Schmidgall, Emma; Bockrath, Marc

2012-03-14

Graphene's high mobility and two-dimensional nature make it an attractive material for field-effect transistors. Previous efforts in this area have used bulk gate dielectric materials such as SiO(2) or HfO(2). In contrast, we have studied the use of an ultrathin layered material, graphene's insulating analogue, graphite oxide. We have fabricated transistors comprising single or bilayer graphene channels, graphite oxide gate insulators, and metal top-gates. The graphite oxide layers show relatively minimal leakage at room temperature. The breakdown electric field of graphite oxide was found to be comparable to SiO(2), typically ~1-3 × 10(8) V/m, while its dielectric constant is slightly higher, κ ≈ 4.3. © 2012 American Chemical Society

Oxidation phase growth diagram of vanadium oxides film fabricated by rapid thermal annealing

Institute of Scientific and Technical Information of China (English)

Tamura KOZO; Zheng-cao LI; Yu-quan WANG; Jie NI; Yin HU; Zheng-jun ZHANG

2009-01-01

Thermal evaporation deposited vanadium oxide films were annealed in air by rapid thermal annealing (RTP). By adjusting the annealing temperature and time, a series of vanadium oxide films with various oxidation phases and surface morphologies were fabricated, and an oxidation phase growth diagram was established. It was observed that different oxidation phases appear at a limited and continuous annealing condition range, and the morphologic changes are related to the oxidation process.

No late effect of ionizing radiation on the aging-related oxidative changes in the mouse brain

International Nuclear Information System (INIS)

Jang, Beom Su; Kim, Seol Wha; Jung, U Hee; Jo, Sung Kee

2010-01-01

Radiation-induced late injury to normal tissue is a primary area of radiation biology research. The present study was undertaken to investigate whether the late effect of the ionizing radiation appears as an age-related oxidative status in the brain. Three groups of 4-month old C57BL/6 mice that were exposed to 137 Cs γ-rays at a single dose (5 Gy) or fractionated doses (1 Gy x 5 times, or 0,2 Gy x 25 times) at 2 months old were investigated for the oxidative status of their brains with both young (2-month) and old (24-month) mice. A significant (p< o.05) decrease in superoxide dismutase (SOD) activity was observed in old mice brains compared with that of the young mice. Malondialdehyde (MDA) content was significantly (p<0.05) increased in the old mice brain. However, any significant difference in SOD activity and MDA contents of the irradiated brain was not observed compared to age-matched control group mice. SOD activity and MDA content were observed within good parameters of brain aging and there no late effects on the age-related oxidative level in the γ-ray irradiated mice brains

No late effect of ionizing radiation on the aging-related oxidative changes in the mouse brain

Energy Technology Data Exchange (ETDEWEB)

Jang, Beom Su; Kim, Seol Wha; Jung, U Hee; Jo, Sung Kee [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

2010-09-15

Radiation-induced late injury to normal tissue is a primary area of radiation biology research. The present study was undertaken to investigate whether the late effect of the ionizing radiation appears as an age-related oxidative status in the brain. Three groups of 4-month old C57BL/6 mice that were exposed to {sup 137}Cs {gamma}-rays at a single dose (5 Gy) or fractionated doses (1 Gy x 5 times, or 0,2 Gy x 25 times) at 2 months old were investigated for the oxidative status of their brains with both young (2-month) and old (24-month) mice. A significant (peffects on the age-related oxidative level in the {gamma}-ray irradiated mice brains.

Fatty Acid Oxidation Compensates for Lipopolysaccharide-Induced Warburg Effect in Glucose-Deprived Monocytes

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Nora Raulien

2017-05-01

Full Text Available Monocytes enter sites of microbial or sterile inflammation as the first line of defense of the immune system and initiate pro-inflammatory effector mechanisms. We show that activation with bacterial lipopolysaccharide (LPS induces them to undergo a metabolic shift toward aerobic glycolysis, similar to the Warburg effect observed in cancer cells. At sites of inflammation, however, glucose concentrations are often drastically decreased, which prompted us to study monocyte function under conditions of glucose deprivation and abrogated Warburg effect. Experiments using the Seahorse Extracellular Flux Analyzer revealed that limited glucose supply shifts monocyte metabolism toward oxidative phosphorylation, fueled largely by fatty acid oxidation at the expense of lipid droplets. While this metabolic state appears to provide sufficient energy to sustain functional properties like cytokine secretion, migration, and phagocytosis, it cannot prevent a rise in the AMP/ATP ratio and a decreased respiratory burst. The molecular trigger mediating the metabolic shift and the functional consequences is activation of AMP-activated protein kinase (AMPK. Taken together, our results indicate that monocytes are sufficiently metabolically flexible to perform pro-inflammatory functions at sites of inflammation despite glucose deprivation and inhibition of the LPS-induced Warburg effect. AMPK seems to play a pivotal role in orchestrating these processes during glucose deprivation in monocytes.

Effect of processing on structural features of anodic aluminum oxides

Science.gov (United States)

Erdogan, Pembe; Birol, Yucel

2012-09-01

Morphological features of the anodic aluminum oxide (AAO) templates fabricated by electrochemical oxidation under different processing conditions were investigated. The selection of the polishing parameters does not appear to be critical as long as the aluminum substrate is polished adequately prior to the anodization process. AAO layers with a highly ordered pore distribution are obtained after anodizing in 0.6 M oxalic acid at 20 °C under 40 V for 5 minutes suggesting that the desired pore features are attained once an oxide layer develops on the surface. While the pore features are not affected much, the thickness of the AAO template increases with increasing anodization treatment time. Pore features are better and the AAO growth rate is higher at 20 °C than at 5 °C; higher under 45 V than under 40 V; higher with 0.6 M than with 0.3 M oxalic acid.

Effect of electrolyte temperature on the formation of self-organized anodic niobium oxide microcones in hot phosphate-glycerol electrolyte

Energy Technology Data Exchange (ETDEWEB)

Yang, S.; Aoki, Y. [Division of Materials Chemistry, Faculty of Engineering, Hokkaido University, Sapporo 060-8628 (Japan); Habazaki, H., E-mail: habazaki@eng.hokudai.ac.jp [Division of Materials Chemistry, Faculty of Engineering, Hokkaido University, Sapporo 060-8628 (Japan)

2011-07-15

Nanoporous niobium oxide films with microcone-type surface morphology were formed by anodizing at 10 V in glycerol electrolyte containing 0.6 mol dm{sup -3} K{sub 2}HPO{sub 4} and 0.2 mol dm{sup -3} K{sub 3}PO{sub 4} in a temperature range of 428-453 K. The microcones appeared after prolonged anodizing, but the required time was largely reduced by increasing electrolyte temperature. The anodic oxide was initially amorphous at all temperatures, but crystalline oxide nucleated during anodizing. The anodic oxide microcones, which were crystalline, appeared on surface as a consequence of preferential chemical dissolution of initially formed amorphous oxide. The chemical dissolution of an initially formed amorphous layer was accelerated by increasing the electrolyte temperature, with negligible influence of the temperature on the morphology of microcones up to 448 K.

Synchrotron X-ray irradiation effects on the device characteristics and the resistance to hot-carrier damage of MOSFETs with 4 nm thick gate oxides

International Nuclear Information System (INIS)

Tanaka, Yuusuke; Tanabe, Akira; Suzuki, Katsumi

1998-01-01

The effects of synchrotron x-ray irradiation on the device characteristics and hot-carrier resistance of n- and p-channel metal oxide semiconductor field effect transistors (MOSFETs) with 4 nm thick gate oxides are investigated. In p-channel MOSFETs, device characteristics were significantly affected by the x-ray irradiation but completely recovered after annealing, while the device characteristics in n-channel MOSFETs were not noticeably affected by the irradiation. This difference appears to be due to a difference in interface-state generation. In p-channel MOSFETs, defects caused by boron-ion penetration through the gate oxides may be sensitive to x-ray irradiation, causing the generation of many interface states. These interface states are completely eliminated after annealing in hydrogen gas. The effects of irradiation on the resistance to hot-carrier degradation in annealed 4 nm thick gate-oxide MOSFETs were negligible even at an x-ray dose of 6,000 mJ/cm 2

Alumina composites for oxide/oxide fibrous monoliths

International Nuclear Information System (INIS)

Cruse, T. A.; Polzin, B. J.; Picciolo, J. J.; Singh, D.; Tsaliagos, R. N.; Goretta, K. C.

2000-01-01

Most work on ceramic fibrous monoliths (FMs) has focused on the Si 3 N 4 /BN system. In an effort to develop oxidation-resistant FMs, several oxide systems have recently been examined. Zirconia-toughened alumina and alumina/mullite appear to be good candidates for the cell phase of FMs. These composites offer higher strength and toughness than pure alumina and good high-temperature stability. By combining these oxides, possibly with a weaker high-temperature oxide as the cell-boundary phase, it should be possible to product a strong, resilient FM that exhibits graceful failure. Several material combinations have been examined. Results on FM fabrication and microstructural development are presented

Effects of Caloric Restriction on Cardiac Oxidative Stress and Mitochondrial Bioenergetics: Potential Role of Cardiac Sirtuins

Directory of Open Access Journals (Sweden)

Ken Shinmura

2013-01-01

Full Text Available The biology of aging has not been fully clarified, but the free radical theory of aging is one of the strongest aging theories proposed to date. The free radical theory has been expanded to the oxidative stress theory, in which mitochondria play a central role in the development of the aging process because of their critical roles in bioenergetics, oxidant production, and regulation of cell death. A decline in cardiac mitochondrial function associated with the accumulation of oxidative damage might be responsible, at least in part, for the decline in cardiac performance with age. In contrast, lifelong caloric restriction can attenuate functional decline with age, delay the onset of morbidity, and extend lifespan in various species. The effect of caloric restriction appears to be related to a reduction in cellular damage induced by reactive oxygen species. There is increasing evidence that sirtuins play an essential role in the reduction of mitochondrial oxidative stress during caloric restriction. We speculate that cardiac sirtuins attenuate the accumulation of oxidative damage associated with age by modifying specific mitochondrial proteins posttranscriptionally. Therefore, the distinct role of each sirtuin in the heart subjected to caloric restriction should be clarified to translate sirtuin biology into clinical practice.

The Inhibition Effect of Cell DNA Oxidative Damage and LDL Oxidation by Bovine Colostrums

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Chih-Wei Chen

2016-10-01

Full Text Available In the present study, we investigated the effect of bovine colostrums on inhibition of DNA oxidative damage and low density lipoprotein (LDL oxidation in vitro. Results showed that whey and skimmed milk exhibited not only higher inhibitory activities of oxidative damage of deoxyribose but also an inhibitory effect on the breakdown of supercoiled DNA into open circular DNA and linear DNA. The quantities of 8-OH-2′-dG formed under whey, caseins and skimmed milk treatment were 0.24, 0.24 and 1.24 μg/mL, respectively. The quantity of malondialdehyde formed through LDL oxidation induced by copprous ion was significantly decreased as colostrums protein solutions were added, in which whey and caseins led to a more significant decrease than skimmed milk. The formation of conjugated dienes could be inhibited by treatment with colostrums protein solutions. Whey exhibited the longest lag time of conjugated dienes formation among the colostrums proteins. The lag time of the whey was 2.33 times that of the control. From the results of foregoing, the bovine colostrums protein has potential value in the inhibition of DNA oxidation damage and LDL oxidation.

The 2016 oxide electronic materials and oxide interfaces roadmap

DEFF Research Database (Denmark)

Lorenz, M.; Rao, M. S. Ramachandra; Venkatesan, T.

2016-01-01

of these materials to understand the tunability of their properties and the novel properties that evolve due to their nanostructured nature is another facet of the challenge. The research related to the oxide electronic field is at an impressionable stage, and this has motivated us to contribute with a roadmap......, Pentcheva, and Gegenwart. Finally, Miletto Granozio presents the European action ‘towards oxide-based electronics’ which develops an oxide electronics roadmap with emphasis on future nonvolatile memories and the required technologies.In summary, we do hope that this oxide roadmap appears as an interesting...

The Effects of Physical Appearance and Behavior Upon Ratings of Social Attractiveness.

Science.gov (United States)

Mahoney, Sandra D.

A videotaped interaction between a stimulus person (SP) and an interviewer was viewed by 80 male and 80 female college students. The SP's physical appearance and behavior were varied in a 2 X 2 X 2 factorial design with student gender as the third independent variable. The effects of these three variables upon general attractiveness ratings and…

Short-term and long-term effects of transient exogenous cortisol manipulation on oxidative stress in juvenile brown trout.

Science.gov (United States)

Birnie-Gauvin, Kim; Peiman, Kathryn S; Larsen, Martin H; Aarestrup, Kim; Willmore, William G; Cooke, Steven J

2017-05-01

In the wild, animals are exposed to a growing number of stressors with increasing frequency and intensity, as a result of human activities and human-induced environmental change. To fully understand how wild organisms are affected by stressors, it is crucial to understand the physiology that underlies an organism's response to a stressor. Prolonged levels of elevated glucocorticoids are associated with a state of chronic stress and decreased fitness. Exogenous glucocorticoid manipulation reduces an individual's ability to forage, avoid predators and grow, thereby limiting the resources available for physiological functions like defence against oxidative stress. Using brown trout ( Salmo trutta ), we evaluated the short-term (2 weeks) and long-term (4 months over winter) effects of exogenous cortisol manipulations (versus relevant shams and controls) on the oxidative status of wild juveniles. Cortisol caused an increase in glutathione over a 2 week period and appeared to reduce glutathione over winter. Cortisol treatment did not affect oxidative stress levels or low molecular weight antioxidants. Cortisol caused a significant decrease in growth rates but did not affect predation risk. Over-winter survival in the stream was associated with low levels of oxidative stress and glutathione. Thus, oxidative stress may be a mechanism by which elevated cortisol causes negative physiological effects. © 2017. Published by The Company of Biologists Ltd.

Oxidation in fish oil-enriched mayonnaise 4 : Effect of tocopherol concentration on oxidative deterioration

DEFF Research Database (Denmark)

Jacobsen, Charlotte; Hartvigsen, Karsten; Lund, Pia

2001-01-01

The effect of the water-dispersible tocopherol preparation, Grindox 1032, and the oil-soluble tocopherol preparation, Toco 70, on oxidative stability in fish oil-enriched mayonnaise was examined. The two commercial antioxidant preparations were supplemented in different levels corresponding to 20......-280 ppm tocopherol in addition to the 600 ppm present in the oils used for the mayonnaise. The oxidative stability was assessed by sensory analysis, the tendency of formation of free radicals, and concentrations of lipid hydroperoxides and volatile oxidation products. The effect of tocopherol on oxidation...... depended on the nature and the concentration of the tocopherol preparation employed, and it also depended on the parameters evaluated. Addition of high levels of Grindox 1032 (similar to 140-280 ppm tocopherol) thus decreased the intensity of rancid off-flavor, but increased the formation of fishy off...

Object Knowledge Modulates Colour Appearance

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Christoph Witzel

2011-01-01

Full Text Available We investigated the memory colour effect for colour diagnostic artificial objects. Since knowledge about these objects and their colours has been learned in everyday life, these stimuli allow the investigation of the influence of acquired object knowledge on colour appearance. These investigations are relevant for questions about how object and colour information in high-level vision interact as well as for research about the influence of learning and experience on perception in general. In order to identify suitable artificial objects, we developed a reaction time paradigm that measures (subjective colour diagnosticity. In the main experiment, participants adjusted sixteen such objects to their typical colour as well as to grey. If the achromatic object appears in its typical colour, then participants should adjust it to the opponent colour in order to subjectively perceive it as grey. We found that knowledge about the typical colour influences the colour appearance of artificial objects. This effect was particularly strong along the daylight axis.

Object knowledge modulates colour appearance

Science.gov (United States)

Witzel, Christoph; Valkova, Hanna; Hansen, Thorsten; Gegenfurtner, Karl R

2011-01-01

We investigated the memory colour effect for colour diagnostic artificial objects. Since knowledge about these objects and their colours has been learned in everyday life, these stimuli allow the investigation of the influence of acquired object knowledge on colour appearance. These investigations are relevant for questions about how object and colour information in high-level vision interact as well as for research about the influence of learning and experience on perception in general. In order to identify suitable artificial objects, we developed a reaction time paradigm that measures (subjective) colour diagnosticity. In the main experiment, participants adjusted sixteen such objects to their typical colour as well as to grey. If the achromatic object appears in its typical colour, then participants should adjust it to the opponent colour in order to subjectively perceive it as grey. We found that knowledge about the typical colour influences the colour appearance of artificial objects. This effect was particularly strong along the daylight axis. PMID:23145224

Biomonitoring of the genotoxic effects and oxidative potentials of commercial edible dung beetles (Onitis sp.), grasshopper (Caelifera sp.) and mole crickets (Gryllotalpa sp.) in vitro.

Science.gov (United States)

Koc, Kubra; Incekara, Umit; Turkez, Hasan

2014-09-01

In this investigation, the genotoxic and oxidative effects of water soluble extracts of dung beetles, flying grasshopper and mole crickets have been assessed on cultured human blood cells. The extracts were added to the culture tubes at 12 different concentrations (0-2000 ppm). Micronucleus test was used to monitor the DNA and the chromosomal damage produced by aqueous extracts in vitro. In addition, to assess the oxidative effects, total antioxidant capacity (TAC) and total oxidant status (TOS) levels were also measured. Our results indicated that these extracts did not show genotoxic effects at the tested concentrations. However, the extracts caused dose-dependent alterations in both TAC and TOS levels. Based on the findings, it was concluded that the studied insects can be consumed safely, but it is necessary to consider the cellular damages which are likely to appear depending on oxidative stress at higher concentrations. It has also been suggested that this in vitro approach for oxidative and genotoxicity assessments may be useful to evaluate the potential health risks of edible insects. © The Author(s) 2014.

Effect of systemic nitric oxide synthase inhibition on optic disc oxygen partial pressure in normoxia and in hypercapnia.

Science.gov (United States)

Petropoulos, Ioannis K; Pournaras, Jean-Antoine C; Stangos, Alexandros N; Pournaras, Constantin J

2009-01-01

To investigate the effect of systemic nitric oxide synthase (NOS) inhibition on optic disc oxygen partial pressure (PO(2)) in normoxia and hypercapnia. Intervascular optic disc PO(2) was measured in 12 anesthetized minipigs by using oxygen-sensitive microelectrodes placed 0.1), despite a 21% increase of mean arterial pressure. Optic disc PO(2) increase under hypercapnia was blunted after L-NAME injection (DeltaPO(2) = 0.6 +/- 1.1 mm Hg; 3%; P > 0.1), and this effect was reversible by L-arginine. Moreover, L-NAME reduced the response to carbogen by 29% (DeltaPO(2) = 9.1 +/- 4.4 mm Hg; 49%; P = 0.01 versus before L-NAME). The response to hyperoxia was not affected. Whereas systemic NOS inhibition did not affect optic disc PO(2) in normoxia, a blunting effect was noted on the CO(2)-induced optic disc PO(2) increase. Nitric oxide appears to mediate the hypercapnic optic disc PO(2) increase.

Interactions of silica with iron oxides: Effects on oxide transformations and sorption properties

Energy Technology Data Exchange (ETDEWEB)

Taylor, P

1995-08-01

This report is a review of the literature on the adsorption of silica species on iron oxides and oxyhydroxides, and its effects on the adsorption of other species and on oxide interconversion reactions. The information is discussed briefly in the contexts of nuclear waste disposal and boiler-water chemistry. (author). 76 refs.

Interactions of silica with iron oxides: Effects on oxide transformations and sorption properties

International Nuclear Information System (INIS)

Taylor, P.

1995-08-01

This report is a review of the literature on the adsorption of silica species on iron oxides and oxyhydroxides, and its effects on the adsorption of other species and on oxide interconversion reactions. The information is discussed briefly in the contexts of nuclear waste disposal and boiler-water chemistry. (author). 76 refs

Effect of exercise training on leucine oxidation

International Nuclear Information System (INIS)

Hendrix, M.K.; Layman, D.K.

1986-01-01

Oxidation of the BCAA leucine is increased during a bout of exhaustive exercise. The purpose of this study was to determine the effects of exercise training on leu oxidation during aerobic exercise. Female Sprague-Dawley rats were fed a commercial diet ad lib and divided into sedentary and two trained groups. Animals were trained to run on a treadmill with a 10 0 incline at 28 m/min for 5 wks for either 50 or 120 min/day. There were no differences in food intake or body weight. After a 12 hr fast, animals were run for 50 or 120 min and changes in leu catabolism determined by measurement of in vivo leu oxidation and activity of branched chain keto acid dehydrogenase (BCKAD). For measurement of leu oxidation, rats were injected IP with 4 μCi 1- 14 C-leu during the last 15 min of exercise, placed in glass metabolic chambers, and 14 CO 2 collected in 1 N NaOH for 30 min periods. Leu oxidation was increased by 40% after 50 min of exercise and by 79% after 120 min of exercise. Five weeks of training reduced the rate of leu oxidation during an exercise bout. The activity of the BCKAD was not increased in the trained animals after either 50 or 120 min of exercise. These data indicate that the rate of leu oxidation during exercises is dependent on the duration of the exercise and that training will reduce the magnitude of this effect

Effect of exercise training on leucine oxidation

Energy Technology Data Exchange (ETDEWEB)

Hendrix, M.K.; Layman, D.K.

1986-03-01

Oxidation of the BCAA leucine is increased during a bout of exhaustive exercise. The purpose of this study was to determine the effects of exercise training on leu oxidation during aerobic exercise. Female Sprague-Dawley rats were fed a commercial diet ad lib and divided into sedentary and two trained groups. Animals were trained to run on a treadmill with a 10/sup 0/ incline at 28 m/min for 5 wks for either 50 or 120 min/day. There were no differences in food intake or body weight. After a 12 hr fast, animals were run for 50 or 120 min and changes in leu catabolism determined by measurement of in vivo leu oxidation and activity of branched chain keto acid dehydrogenase (BCKAD). For measurement of leu oxidation, rats were injected IP with 4 ..mu..Ci 1-/sup 14/C-leu during the last 15 min of exercise, placed in glass metabolic chambers, and /sup 14/CO/sub 2/ collected in 1 N NaOH for 30 min periods. Leu oxidation was increased by 40% after 50 min of exercise and by 79% after 120 min of exercise. Five weeks of training reduced the rate of leu oxidation during an exercise bout. The activity of the BCKAD was not increased in the trained animals after either 50 or 120 min of exercise. These data indicate that the rate of leu oxidation during exercises is dependent on the duration of the exercise and that training will reduce the magnitude of this effect.

Color appearance in stereoscopy

Science.gov (United States)

Gadia, Davide; Rizzi, Alessandro; Bonanomi, Cristian; Marini, Daniele; Galmonte, Alessandra; Agostini, Tiziano

2011-03-01

The relationship between color and lightness appearance and the perception of depth has been studied since a while in the field of perceptual psychology and psycho-physiology. It has been found that depth perception affects the final object color and lightness appearance. In the stereoscopy research field, many studies have been proposed on human physiological effects, considering e.g. geometry, motion sickness, etc., but few has been done considering lightness and color information. Goal of this paper is to realize some preliminar experiments in Virtual Reality in order to determine the effects of depth perception on object color and lightness appearance. We have created a virtual test scene with a simple 3D simultaneous contrast configuration. We have created three different versions of this scene, each with different choices of relative positions and apparent size of the objects. We have collected the perceptual responses of several users after the observation of the test scene in the Virtual Theater of the University of Milan, a VR immersive installation characterized by a semi-cylindrical screen that covers 120° of horizontal field of view from an observation distance of 3.5 m. We present a description of the experiments setup and procedure, and we discuss the obtained results.

Oxidative stress and the effect of parasites on a carotenoid-based ornament.

Science.gov (United States)

Mougeot, F; Martínez-Padilla, J; Blount, J D; Pérez-Rodríguez, L; Webster, L M I; Piertney, S B

2010-02-01

Oxidative stress, the physiological condition whereby the production of reactive oxygen and nitrogen species overwhelms the capacity of antioxidant defences, causes damage to key bio-molecules. It has been implicated in many diseases, and is proposed as a reliable currency in the trade-off between individual health and ornamentation. Whether oxidative stress mediates the expression of carotenoid-based signals, which are among the commonest signals of many birds, fish and reptiles, remains controversial. In the present study, we explored interactions between parasites, oxidative stress and the carotenoid-based ornamentation of red grouse Lagopus lagopus scoticus. We tested whether removing nematode parasites influenced both oxidative balance (levels of oxidative damage and circulating antioxidant defences) and carotenoid-based ornamentation. At the treatment group level, parasite purging enhanced the size and colouration of ornaments but did not significantly affect circulating carotenoids, antioxidant defences or oxidative damage. However, relative changes in these traits among individuals indicated that males with a greater number of parasites prior to treatment (parasite purging) showed a greater increase in the levels of circulating carotenoids and antioxidants, and a greater decrease in oxidative damage, than those with initially fewer parasites. At the individual level, a greater increase in carotenoid pigmentation was associated with a greater reduction in oxidative damage. Therefore, an individual's ability to express a carotenoid-based ornament appeared to be linked to its current oxidative balance and susceptibility to oxidative stress. Our experimental results suggest that oxidative stress can mediate the impact of parasites on carotenoid-based signals, and we discuss possible mechanisms linking carotenoid-based ornaments to oxidative stress.

The kinetics for ammonium and nitrite oxidation under the effect of hydroxylamine.

Science.gov (United States)

Wan, Xinyu; Xiao, Pengying; Zhang, Daijun; Lu, Peili; Yao, Zongbao; He, Qiang

2016-01-01

The kinetics for ammonium (NH4(+)) oxidation and nitrite (NO2(-)) oxidation under the effect of hydroxylamine (NH2OH) were studied by respirometry using the nitrifying sludge from a laboratory-scale sequencing batch reactor. Modified models were used to estimate kinetics parameters of ammonia and nitrite oxidation under the effect of hydroxylamine. An inhibition effect of hydroxylamine on the ammonia oxidation was observed under different hydroxylamine concentration levels. The self-inhibition coefficient of hydroxylamine oxidation and noncompetitive inhibition coefficient of hydroxylamine for nitrite oxidation was estimated by simulating exogenous oxygen-uptake rate profiles, respectively. The inhibitive effect of NH2OH on nitrite-oxidizing bacteria was stronger than on ammonia-oxidizing bacteria. This work could provide fundamental data for the kinetic investigation of the nitrification process.

Effect of oxygen on decomposition of nitrous oxide over various metal oxide catalysts

International Nuclear Information System (INIS)

Satsuma, Atsushi; Maeshima, Hajime; Watanabe, Kiyoshi; Hattori, Tadashi

2001-01-01

The inhibitory effect of oxygen on decomposition of nitrous oxide over various metal oxide catalysts was investigated. The activity of nitrous oxide decomposition significantly decreased over CuO, Co 3 O 4 , NiO, Fe 2 O 3 , SnO 2 , In 2 O 3 and Cr 2 O 3 by reversible adsorption of oxygen onto the active sites. On the contrary to this, there was no or small change in the activity of TiO 2 , Al 2 O 3 , MgO, La 2 O 3 and CaO. A good correlation was observed between the degree of inhibition and the heat of formation of metal oxides. On the basis of kinetic model, the reduction of catalytic activity in the presence of oxygen was rationalized with the strength of oxygen adsorption on the metal oxide surface. (author)

Protective effect of nitric oxide against arsenic-induced oxidative ...

African Journals Online (AJOL)

The effects of NO on alleviating arsenic-induced oxidative damage in tall fescue leaves were investigated. Arsenic (25 M) treatment induced significantly accumulation of reactive oxygen species (ROS) and led to serious lipid peroxidation in tall fescue leaves and the application of 100 M SNP before arsenic stress resulted ...

EFFECTS OF TOLUENE ON BRAIN OXIDATIVE STRESS PARAMETERS IN AGING BROWN NORWAY RATS

Science.gov (United States)

Aging-related susceptibility to environmental chemicals is poorly understood. Oxidative stress (OS) appears to play an important role in susceptibility and disease in old age. The objectives of this study, therefore, were to test whether OS is a potential toxicity pathway for tol...

Irradiation Effect on Oxidative Condition and Tocopherol Content of Vegetable Oils

Directory of Open Access Journals (Sweden)

Konstantinos Sflomos

2007-06-01

Full Text Available The effect on induction period and tocopherol content after γ-irradiation onsamples of olive oil and seed oils (sunflower and soybean was determined. In seed oilsamples 0, 100, 200 and 300 ppm of δ-tocopherol were added before irradiation with 1, 2and 3kGy. The results of induction period showed that, after irradiation, all samplespresented a significant decreased in resistance to oxidation. However, this decrease wasminimized when δ-tocopherol was added. Irradiation significantly decreased the level oftocopherols. δ-Tocopherol appeared more sensitive in irradiation process than α- andγ-tocopherol. The addition of δ-tocopherol significantly reduced, in most cases, thedepletion of the other tocopherols.

Possible oxidative effects of isotretinoin and modulatory effects of ...

African Journals Online (AJOL)

... in the treatment of nodular cystic acne and as an inhibitor of proliferation of neoplastic cells, by exerting a regulatory effect on the cell differentiation. This study aimed at investigating the possible oxidative effects of ITN and modulatory effects of vitamins A and C in mutant and non-mutant Saccharomyces cerevisiae strains.

The effect of anesthesia on the radiographic appearance of the coxofemoral joints

International Nuclear Information System (INIS)

Aronson, E.; Kraus, K.H.; Smith, J.

1991-01-01

The effect of anesthesia on the radiographic appearance of the coxofemoral joints was evaluated by taking pelvic radiographs of thirty dogs. Each dog was radiographed twice, once under general anesthesia and once without anesthesia. The radiographs were submitted to the Orthopedic Foundation for Animals independently of one another to be evaluated for signs of hip dysplasia. Results suggest there was no statistical difference between the two groups of dogs. Twenty five dogs received the same reading. Three dogs received readings that were worse by one grade while under anesthesia and two dogs received readings that were one grade better while under anesthesia. This study failed to demonstrate any changes due to anesthesia on the radiographic appearance of the coxofemoral joints. Anesthesia may, however, be beneficial for proper positioning and to decrease unnecessary patient, and personnel exposure to radiation

Inhibition of apparent photosynthesis by nitrogen oxides

Energy Technology Data Exchange (ETDEWEB)

Hill, A C; Bennett, J H

1970-01-01

The nitrogen oxides (NO/sub 2/ and NO) inhibited apparent photosynthesis of oats and alfalfa at concentrations below those required to cause visible injury. There appeared to be a threshold concentration of about 0.6 ppm for each pollutant. An additive effect in depressing apparent photosynthesis occurred when the plants were exposed to a mixture of NO and NO/sub 2/. Although NO produced a more rapid effect on the plants, lower concentrations of NO/sub 2/ were required to cause a given inhibition after 2 hour of exposure. Inhibition by nitric oxide was more closely related to its partial pressure than was inhibition by NO/sub 2/.

The effects of trichloroethane HCl and ion-implantation on the oxidation rate of silicon

International Nuclear Information System (INIS)

Ahmed, W.; Ahmed, E.

1994-01-01

The thermal oxidation of silicon was studied using a large-scale industrial oxidation system. The characteristics of the oxides resulting from pure hydrogen/oxygen (Hsub(2)/Osub(2)), trichloroethane/oxygen (TCA/Osub(2) and hydrogen chloride/oxygen (HCI/Osub(2)) mixtures are compared. Both HCI and TCA addition to oxygen produced an enhanced oxidation rate. The oxidation rate for TCA/Osub(2) was approximately 30-40% higher than for HCI/Osub(2) mixtures. A molar ratio of TCA/Osub(2) of 1% gives an optimum process for very-large-scale industrial (VLSI) applications. However, 3% HCI/Osub(2) gives comparable results to 1% TCA. In addition, boron and phosphorus implantation are observed to increase the oxidation rate. Phosphorus doping of the silicon yields a higher rate than boron-doped wafers. This behaviour is explained in terms of surface damage and chemistry. It appears that the overall mechanisms governing all these processes are similar. (8 figures, 22 references) (Author)

The effect of grape-skin extract on oxidative status

DEFF Research Database (Denmark)

Young, J. F.; Dragsted, L. O.; Daneshvar, B.

2000-01-01

dismutase or catalase. Likewise, no effect was found on 2-aminoadipic semialdehyde (AAS) residues, a plasma protein oxidation product, or on malondialdehyde in plasma or in LDL, which are markers of lipoprotein oxidation. A marginal effect of grape-skin intervention was observed on plasma ascorbate levels...

Review: Effect of Sexual Violence in Appearance of Post Traumatic Stress Disorder (PTSD

Directory of Open Access Journals (Sweden)

Ja'far Mirzaei

2007-01-01

Full Text Available The familial violence is any violent action based on sexual dispute that result in somatic, sexual or psychiatric hurts or pain. One of the familial violence is child and spouse abuse that result in depression, anxiety and PTSD. The aim of this article is study of familial violence phenomena from different psychiatric and social views and the rate of appearance and epidemiology and clinical character of PTSD as the result of sexual rape. This study is based on review of literature and antecedent & internal and external investigations from 1989 to 2004 from internet sites like NC PTSD psychilt – psych Info. Conclusions of different accidental and nonaccidental studies sign the rate of 25 – 30% psychiatric side effects as the result of somatic and sexual abuse and appearance of PTSD-Depression and Anxiety. Because the phenomena of familial and sexual violence has social and psychiatric nature, It is necessary to take health care and educative and preventive methods for prevention of appearance of such injuries in society and support from familial and social network.

Effects of stress on the oxide layer thickness and post-oxidation creep strain of zircaloy-4

International Nuclear Information System (INIS)

Lim, Sang Ho; Yoon, Young Ku

1986-01-01

Effects of compressive stress generated in the oxide layer and its subsequent relief on oxidation rate and post-oxidation creep characteristics of zircaloy-4 were investigated by oxidation studies in steam with and without applied tensile stress and by creep testing at 700 deg C in high purity argon. The thickness of oxide layer increased with the magnitude of tensile stress applied during oxidation at 650 deg C in steam whereas similar phenomenon was not observed during oxidation at 800 deg C. Zircaloy-4 specimens oxidized at 600 deg C in steam without applied stress exhibited higher creep strain than that shown by unoxidized specimens when creep-tested in argon. Zircaloy-4 specimens oxidized at 600 deg C steam under the applied stress of 8.53MPa and oxidized at 800 deg C under the applied stress of 0 and 8.53MPa exhibited lower strain than that shown by unoxidized specimen. The above experimental results were accounted for on the basis of interactions among applied stress during oxidation, compressive stress generated in the oxide layer and elasticity of zircaloy-4 matrix. (Author)

Protective effects of hesperidin against oxidative stress of tert-butyl hydroperoxide in human hepatocytes.

Science.gov (United States)

Chen, Mingcang; Gu, Honggang; Ye, Yiyi; Lin, Bing; Sun, Lijuan; Deng, Weiping; Zhang, Jingzhe; Liu, Jianwen

2010-10-01

Increasing evidence regarding free radical generating agents and the inflammatory process suggest that accumulation of reactive oxygen species (ROS) could involve hepatotoxicity. Hesperidin, a naturally occurring flavonoid presents in fruits and vegetables, has been reported to exert a wide range of pharmacological effects that include antioxidant, anti-inflammatory, antihypercholesterolemic, and anticarcinogenic actions. However, the cytoprotection and mechanism of hesperidin to neutralize oxidative stress in human hepatic L02 cells remain unclear. In this work, we assessed the capability of hesperidin to prevent tert-butyl hydroperoxide (t-BuOOH)-induced cell damage by augmenting cellular antioxidant defense. Hesperidin significantly protected hepatocytes against t-BuOOH-induced cell cytotoxicity, such as mitochondrial membrane potential (MMP) deplete and lactate dehydrogenase (LDH) release. Hesperidin also remarkably prevented indicators of oxidative stress, such as the ROS and lipid peroxidation level in a dose-dependent manner. Western blot showed that hesperidin facilitated ERK/MAPK phosphorylation which appeared to be responsible for nuclear translocation of Nrf2, thereby inducing cytoprotective heme oxygenase-1 (HO-1) expression. Based on the results described above, it suggested that hesperidin has potential as a therapeutic agent in the treatment of oxidative stress-related hepatocytes injury and liver dysfunctions. Copyright © 2010 Elsevier Ltd. All rights reserved.

Anti-oxidative effects of Rooibos tea (Aspalathus linearis on immobilization-induced oxidative stress in rat brain.

Directory of Open Access Journals (Sweden)

In-Sun Hong

Full Text Available Exposure to chronic psychological stress may be related to increased reactive oxygen species (ROS or free radicals, and thus, long-term exposure to high levels of oxidative stress may cause the accumulation of oxidative damage and eventually lead to many neurodegenerative diseases. Compared with other organs, the brain appears especially susceptible to excessive oxidative stress due to its high demand for oxygen. In the case of excessive ROS production, endogenous defense mechanisms against ROS may not be sufficient to suppress ROS-associated oxidative damage. Dietary antioxidants have been shown to protect neurons against a variety of experimental neurodegenerative conditions. In particular, Rooibos tea might be a good source of antioxidants due to its larger proportion of polyphenolic compounds. An optimal animal model for stress should show the features of a stress response and should be able to mimic natural stress progression. However, most animal models of stress, such as cold-restraint, electric foot shock, and burn shock, usually involve physical abuse in addition to the psychological aspects of stress. Animals subjected to chronic restraint or immobilization are widely believed to be a convenient and reliable model to mimic psychological stress. Therefore, in the present study, we propose that immobilization-induced oxidative stress was significantly attenuated by treatment with Rooibos tea. This conclusion is demonstrated by Rooibos tea's ability to (i reverse the increase in stress-related metabolites (5-HIAA and FFA, (ii prevent lipid peroxidation (LPO, (iii restore stress-induced protein degradation (PD, (iv regulate glutathione metabolism (GSH and GSH/GSSG ratio, and (v modulate changes in the activities of antioxidant enzymes (SOD and CAT.

Lipolysis and lipid oxidation in fermented sausages depending on different processing conditions and different antioxidants.

Science.gov (United States)

Zanardi, Emanuela; Ghidini, Sergio; Battaglia, Alessandra; Chizzolini, Roberto

2004-02-01

Lipolysis and lipid oxidation in Mediterranean and North Europe type sausages were studied in relation to raw material, processing conditions and additives. In particular the effect of ascorbic acid, nitrites and spices was evaluated. Lipolysis was measured by the determination of total and free fatty acids of fresh minces and matured products and lipid oxidation was evaluated by thiobarbituric acid reactive substances and cholesterol oxidation products. The increase of free fatty acids during maturation appears to be independent from processing conditions and the differences in polyunsaturated fatty acids increment found among the formulations appear to be due to inherent variations of raw materials. The presence of ascorbic acid and/or nitrite seems important for cholesterol protection and, as a consequence, for the safety of fermented meat products while spices at doses up to 0.1% do not seem to have a remarkable effect. The effect on fatty acid oxidation of the same additives and of the different processing technologies is not significantly different and the variations linked to raw material may play the greatest role.

Body Dissatisfaction among Adolescent Boys and Girls: The Effects of Body Mass, Peer Appearance Culture and Internalization of Appearance Ideals

Science.gov (United States)

Lawler, Margaret; Nixon, Elizabeth

2011-01-01

Body image dissatisfaction is a significant risk factor in the onset of eating pathology and depression. Therefore, understanding predictors of negative body image is an important focus of investigation. This research sought to examine the contributions of body mass, appearance conversations with friends, peer appearance criticism and…

Color categories and color appearance

Science.gov (United States)

Webster, Michael A.; Kay, Paul

2011-01-01

We examined categorical effects in color appearance in two tasks, which in part differed in the extent to which color naming was explicitly required for the response. In one, we measured the effects of color differences on perceptual grouping for hues that spanned the blue–green boundary, to test whether chromatic differences across the boundary were perceptually exaggerated. This task did not require overt judgments of the perceived colors, and the tendency to group showed only a weak and inconsistent categorical bias. In a second case, we analyzed results from two prior studies of hue scaling of chromatic stimuli (De Valois, De Valois, Switkes, & Mahon, 1997; Malkoc, Kay, & Webster, 2005), to test whether color appearance changed more rapidly around the blue–green boundary. In this task observers directly judge the perceived color of the stimuli and these judgments tended to show much stronger categorical effects. The differences between these tasks could arise either because different signals mediate color grouping and color appearance, or because linguistic categories might differentially intrude on the response to color and/or on the perception of color. Our results suggest that the interaction between language and color processing may be highly dependent on the specific task and cognitive demands and strategies of the observer, and also highlight pronounced individual differences in the tendency to exhibit categorical responses. PMID:22176751

Effect of oxide ion concentration on the electrochemical oxidation of carbon in molten LiCl

International Nuclear Information System (INIS)

Yun, J. W.; Choi, I. K.; Park, Y. S.; Kim, W. H.

2001-01-01

The continuous measurement of lithium oxide concentration was required in DOR (Direct Oxide Reduction) process, which converts spent nuclear fuel to metal form, for the reactivity monitor and effective control of the process. The concentration of lithium oxide was measured by the electrochemical method, which was based on the phenomenon that carbon atoms of glassy carbon electrode electrochemically react with oxygen ions of lithium oxide in molten LiCl medium. From the results of electrode polarization experiments, the trend of oxidation rate of carbon atoms was classified into two different regions, which were proportional and non-proportional ones, dependent on the amount of lithium oxide. Below about 2.5 wt % Li 2 O, as the carbon atom ionization rate was fast enough for reacting with diffusing lithium oxide to the surface of carbon electrode. In this concentration range, the oxidation rate of carbon atoms was controlled by the diffusion of lithium oxide, and the concentration of lithium oxide could be measured by electrochemical method. But, above 2.5 wt % Li 2 O, the oxidation rate of carbon atoms was controlled by the applied electrochemical potential, because the carbon atom ionization rate was suppressed by the huge amounts of diffusing Li 2 O. Above this concentration, the electrochemical method was not applicable to determine the concentration of lithium oxide

Protective effects of flavonoids from corn silk on oxidative stress ...

African Journals Online (AJOL)

Protective effects of flavonoids from corn silk on oxidative stress induced by ... The present study aims at exploring the effects of flavonoids from corn silk (FCS) on oxidative stress induced by exhaustive exercise in mice. ... from 32 Countries:.

Effect of catalysts on heterogeneous oxidation of coal

Energy Technology Data Exchange (ETDEWEB)

Glazkova, A P; Kazarova, Yu A; Suslov, A V

1978-01-01

Analyzes the effects of catalysts on the heterogeneous oxidation of coal in deflagration processes of stoichiometric mixtures. The following substances are studied as catalysts: alkali and alkaline-earth metals, and compounds of copper, lead, chromium, iron, and sulfur. In the first case the catalysts are used in the form of nitrates and the nitrate simultaneously plays the role of an oxidizer. In the second case the catalysts are added to stoichiometric mixtures of ammonium nitrate with carbon. It is shown that during carbon oxidation by nitrates the catalytic efficiency of the metals studied forms the following order: sodium > lead > potassium > barium > aluminium > calcium > magnesium > copper. The calculated and experimental parameters of combustion are given. The problem of dependence of combustion rate on combustion heat, the mechanism of the combustion reaction and the catalytic effects of the additives are discussed. Features of heterogeneous catalysis in the oxidation process of carbon by various oxidizers are analyzed. The investigations on the combustion process are important as the process takes place during explosion of coal dust in underground coal mines and during burning of coal in industrial furnaces. (34 refs.) (In Russian)

Effects of sulfur oxides on eicosanoids

International Nuclear Information System (INIS)

Chen, L.C.; Miller, P.D.; Amdur, M.O.

1989-01-01

Ultrafine metal oxides and SO2 react during coal combustion or smelting operations to form primary emissions coated with an acidic SOx layer. Ongoing work in this laboratory has examined the effects of sulfur oxides on pulmonary functions of guinea pigs. We have previously reported that 20 micrograms/m3 acidic sulfur oxide as a surface layer on ultrafine ZnO particles decreases lung volumes, decreases carbon monoxide diffusing capacity, and causes lung inflammation in guinea pigs after 4 daily 3-h exposures. It also produces bronchial hypersensitivity following a single 1-h exposure. The importance of this surface layer is demonstrated by our observation that 200 micrograms/m3 of sulfuric acid droplets of equivalent size are needed to produce the same degree of hypersensitivity. This study characterized the concentration-dependent effects of in vivo exposures to sulfur oxides on arachidonic acid metabolism in the guinea pig lung, and investigated the time course and the relation between eicosanoid composition and pulmonary functions. We focused specifically on four cyclooxygenase metabolites of arachidonic acid, that is, prostaglandins (PG) E1, F2 alpha, 6-keto prostaglandin F1 alpha, and thromboxane (Tx) B2, and two groups of sulfidopeptide leukotrienes (C4, D4, E4, and F4). Guinea pigs were exposed to ultrafine ZnO aerosol (count median diameter = 0.05 microns, sigma g = 1.80) with a layer of acidic sulfur oxide on the surface of the particles. Lung lavage was collected after exposures, and the levels of arachidonic acid metabolites were determined using radioimmunoassay (RIA). Concentration-dependent promotion of PGF2 alpha and concentration-dependent suppression of LtB4 were observed. The increased PGF2 alpha was associated with depressed vital capacity and diffusing capacity of the lungs measured in guinea pigs exposed to the same atmosphere described in a previous study

A Nucleocytoplasmic Shuttling Protein in Oxidative Stress Tolerance

Energy Technology Data Exchange (ETDEWEB)

Ow, David W.; Song, Wen

2003-03-26

Plants for effective extraction of toxic metals and radionuclides must tolerate oxidative stress. To identify genes that enhance oxidative stress tolerance, an S. pombe cDNA expression plasmid library was screened for the ability to yield hypertolerant colonies. Here, we report on the properties of one gene that confers hypertolerance to cadmium and oxidizing chemicals. This gene appears to be conserved in other organisms as homologous genes are found in human, mouse, fruitfly and Arabidopsis. The fruitfly and Arabidopsis genes likewise enhance oxidative stress tolerance in fission yeast. During oxidative stress, the amount of mRNA does not change, but protein fusions to GFP relocate from the cytoplasm to the nucleus. The same pattern is observed with the Arabidopsis homologue-GFP fusion protein. This behavior suggests a signaling role in oxidative stress tolerance and these conserved proteins may be targets for engineering stress tolerant plants for phytoremediation.

Color Categories and Color Appearance

Science.gov (United States)

Webster, Michael A.; Kay, Paul

2012-01-01

We examined categorical effects in color appearance in two tasks, which in part differed in the extent to which color naming was explicitly required for the response. In one, we measured the effects of color differences on perceptual grouping for hues that spanned the blue-green boundary, to test whether chromatic differences across the boundary…

Effect of meat appearance on consumer preferences for pork chops in Greece and Cyprus.

Science.gov (United States)

Fortomaris, P; Arsenos, G; Georgiadis, M; Banos, G; Stamataris, C; Zygoyiannis, D

2006-04-01

The effect of meat appearance on consumers' preferences for pork chops was assessed using images manipulated for appearance characteristics. Data were collected from 412 consumers in Greece and Cyprus. Consumers were asked for their preference for pork chops from a book of computer-modified images and then completed a questionnaire of socio-demographic information, including eating and purchasing behaviour. Consumers under the age of 35 years showed preferences for dark red, lean pork, while consumers aged 35 years and older preferred either dark or light red pork. Gender appeared to be an important selection factor as men showed an increased preference for dark red pork while women preferred the light red. Consumers who stated that they like pork for its taste (91%) preferred either dark or light red pork chops while those who like pork for reasons other than taste preferred dark red, lean pork. Urban consumers preferred light red, fatty pork chops while the rural consumers preferred the dark red pork chops.

Stability and effectiveness against bacterial adhesion of poly(ethylene oxide) coatings in biological fluids.

Science.gov (United States)

Roosjen, Astrid; de Vries, Joop; van der Mei, Henny C; Norde, Willem; Busscher, Henk J

2005-05-01

Poly(ethylene oxide) (PEO) coatings have been shown to reduce the adhesion of different microbial strains and species and thus are promising as coatings to prevent biomaterial-centered infection of medical implants. Clinically, however, PEO coatings are not yet applied, as little is known about their stability and effectiveness in biological fluids. In this study, PEO coatings coupled to a glass substratum through silyl ether bonds were exposed for different time intervals to saliva, urine, or phosphate-buffered saline (PBS) as a reference at 37 degrees C. After exposure, the effectiveness of the coatings against bacterial adhesion was assessed in a parallel plate flow chamber. The coatings appeared effective against Staphylococcus epidermidis adhesion for 24, 48, and 0.5 h in PBS, urine, and saliva, respectively. Using XPS and contact-angle measurements, the variations in effectiveness could be attributed to conditioning film formation. The overall short stability results from hydrolysis of the coupling of the PEO chains to the substratum. (c) 2005 Wiley Periodicals, Inc.

Low temperature spent fuel oxidation under tuff repository conditions

International Nuclear Information System (INIS)

Einziger, R.E.; Woodley, R.E.

1985-01-01

The Nevada Nuclear Waste Storage Investigations Project is studying the suitability of tuffaceous rocks at Yucca Mountain, Nye County, Nevada, for high level waste disposal. The oxidation state of LWR spent fuel in a tuff repository may be a significant factor in determining its ability to inhibit radionuclide migration. Long term exposure at low temperatures to the moist air expected in a tuff repository is expected to increase the oxidation state of the fuel. A program is underway to determine the spent fuel oxidation mechanisms which might be active in a tuff repository. Initial work involves a series of TGA experiments to determine the effectiveness of the technique and to obtain preliminary oxidation data. Tests were run at 200 0 C and 225 0 C for as long as 720 hours. Grain boundary diffusion appears to open up a greater surface area for oxidation prior to onset of bulk diffusion. Temperature strongly influences the oxidation rates. The effect of moisture is small but readily measurable. 25 refs., 7 figs., 4 tabs

A Comparison of the Effects of Neuronal Nitric Oxide Synthase and Inducible Nitric Oxide Synthase Inhibition on Cartilage Damage

Directory of Open Access Journals (Sweden)

Nevzat Selim Gokay

2016-01-01

Full Text Available The objective of this study was to investigate the effects of selective inducible nitric oxide synthase and neuronal nitric oxide synthase inhibitors on cartilage regeneration. The study involved 27 Wistar rats that were divided into five groups. On Day 1, both knees of 3 rats were resected and placed in a formalin solution as a control group. The remaining 24 rats were separated into 4 groups, and their right knees were surgically damaged. Depending on the groups, the rats were injected with intra-articular normal saline solution, neuronal nitric oxide synthase inhibitor 7-nitroindazole (50 mg/kg, inducible nitric oxide synthase inhibitor amino-guanidine (30 mg/kg, or nitric oxide precursor L-arginine (200 mg/kg. After 21 days, the right and left knees of the rats were resected and placed in formalin solution. The samples were histopathologically examined by a blinded evaluator and scored on 8 parameters. Although selective neuronal nitric oxide synthase inhibition exhibited significant (P=0.044 positive effects on cartilage regeneration following cartilage damage, it was determined that inducible nitric oxide synthase inhibition had no statistically significant effect on cartilage regeneration. It was observed that the nitric oxide synthase activation triggered advanced arthrosis symptoms, such as osteophyte formation. The fact that selective neuronal nitric oxide synthase inhibitors were observed to have mitigating effects on the severity of the damage may, in the future, influence the development of new agents to be used in the treatment of cartilage disorders.

Clumped isotope effects during OH and Cl oxidation of methane

DEFF Research Database (Denmark)

Whitehill, Andrew R.; Joelsson, Lars Magnus T.; Schmidt, Johan Albrecht

2017-01-01

A series of experiments were carried out to determine the clumped (13CH3D) methane kinetic isotope effects during oxidation of methane by OH and Cl radicals, the major sink reactions for atmospheric methane. Experiments were performed in a 100 L quartz photochemical reactor, in which OH was produ......A series of experiments were carried out to determine the clumped (13CH3D) methane kinetic isotope effects during oxidation of methane by OH and Cl radicals, the major sink reactions for atmospheric methane. Experiments were performed in a 100 L quartz photochemical reactor, in which OH...... effects for singly substituted species were consistent with previous experimental studies. For doubly substituted methane, 13CH3D, the observed kinetic isotope effects closely follow the product of the kinetic isotope effects for the 13C and deuterium substituted species (i.e., 13,2KIE = 13KIE × 2KIE...... reactions. In a closed system, however, this effect is overtaken by the large D/H isotope effect, which causes the residual methane to become anti-clumped relative to the initial methane. Based on these results, we demonstrate that oxidation of methane by OH, the predominant oxidant for tropospheric methane...

Further studies on 4-hydroxy-3-methoxyphenylglycol oxidation in humans: effect of pool expansion and stereochemistry

Energy Technology Data Exchange (ETDEWEB)

Mardh, G.

1983-08-01

The in vivo oxidation of the norepinephrine metabolite 4-hydroxy-3-methoxyphenylglycol (HMPG) to 4-hydroxy-3-methoxymandelic acid was studied in man with two different doses of deuterium-labeled HMPG and a tracer dose of (/sup 14/C)HMPG. HMPG oxidation appeared to be dose-dependent with an oxidation of 62-70% for doses below or equal to 2.2 mumol. With the use of a capillary column coated with an optically active phase (Chirasil-Val) and gas chromatography mass-spectrometry the human urinary excretions of the two stereoisomers of deuterium-labelled HMPG (free + conjugates) were found to be equal.

The Impact of Appearance Management Training, Work Status, and Plans after High School on Opinions Regarding Appearance at Work and School

Science.gov (United States)

Freeburg, Beth Winfrey; Arnett, Sally E.

2010-01-01

The purpose of this study was to measure the effect of appearance management training, work status, and plans after high school on students' opinions about appearance at school and at work. A nonprobability sample of 132 high school juniors and seniors in a consumer education class were administered the Appearance Management Survey before and…

Effects of maternal subclinical hypothyroidism on amniotic fluid cells oxidative status.

Science.gov (United States)

Novakovic, Tanja R; Dolicanin, Zana C; Djordjevic, Natasa Z

2018-06-01

In this study, we researched the effects of maternal subclinical hypothyroidism on the amniotic fluid cells oxidative metabolism during the first trimester of pregnancy. Oxidative stress and damage biomarkers were assayed in the amniotic fluid cells of healthy and pregnant women with subclinical hypothyroidism. Obtained results show that amniotic fluid cells of pregnant women with subclinical hypothyroidism have significantly higher concentrations of oxidative stress biomarkers (superoxide anion, nitric oxide, peroxynitrite) and oxidative damage (lipid peroxide and micronuclei frequency), but lower concentrations of hydrogen peroxide and oxidized glutathione in comparison to healthy pregnant women. We also showed that oxidative stress biomarkers were positively correlated with micronuclei frequency and lipid peroxide concentration in amniotic fluid cells of pregnant women with subclinical hypothyroidism. The present study provides the first evidence for prooxidative effects of maternal subclinical hypothyroidism on the fetus obtained by the estimating oxidative metabolism in the amniotic fluid cells. Copyright © 2018 Elsevier Inc. All rights reserved.

A method to measure the effect of food appearance factors on children's visual preferences

DEFF Research Database (Denmark)

Kildegaard, Heidi; Olsen, Annemarie; Gabrielsen, Gorm

2011-01-01

The aim of the study was to examine children’s visual preferences for two food products; yoghurts and smoothies, by using a conjoint layout. In total, 274 children performed an incomplete ranking of 8 pictures formed by three factors each with two levels (23 design). The three food appearance...... for the eight smoothies. The children visually preferred the two products without visible fruit and colour had a large influence on visual preferences too. As regards the yoghurts, the children accepted a less simple variant whereas the most preferred smoothie was very simple. Significant synergetic effects...... between food appearance factors and segmentation factors were found. Additionally gender and ethnicity were found to be influential drivers for food choice....

Comparing XPS on bare and capped ZrN films grown by plasma enhanced ALD: Effect of ambient oxidation

Science.gov (United States)

Muneshwar, Triratna; Cadien, Ken

2018-03-01

In this article we compare x-ray photoelectron spectroscopy (XPS) measurements on bare- and capped- zirconium nitride (ZrN) films to investigate the effect of ambient sample oxidation on the detected bound O in the form of oxide ZrO2 and/or oxynitride ZrOxNy. ZrN films in both bare- and Al2O3/AlN capped- XPS samples were grown by plasma-enhanced atomic layer deposition (PEALD) technique using tetrakis dimethylamino zirconium (TDMAZr) precursor, forming gas (5% H2, rest N2) inductively coupled plasma (ICP), and as received research grade process gases under identical process conditions. Capped samples were prepared by depositing 1 nm thick PEALD AlN on ZrN, followed by additional deposition of 1 nm thick ALD Al2O3, without venting of ALD reactor. On bare ZrN sample at room temperature, spectroscopic ellipsometry (SE) measurements with increasing ambient exposure times (texp) showed a self-limiting surface oxidation with the oxide thickness (dox) approaching 3.7 ± 0.02 nm for texp > 120 min. In XPS data measured prior to sample sputtering (tsput = 0), ZrO2 and ZrOxNy were detected in bare- samples, whereas only ZrN and Al2O3/AlN from capping layer were detected in capped- samples. For bare-ZrN samples, appearance of ZrO2 and ZrOxNy up to sputter depth (dsput) of 15 nm in depth-profile XPS data is in contradiction with measured dox = 3.7 nm, but explained from sputtering induced atomic inter-diffusion within analyzed sample. Appearance of artifacts in the XPS spectra from moderately sputtered (dsput = 0.2 nm and 0.4 nm) capped-ZrN sample, provides an evidence to ion-bombardment induced modifications within analyzed sample.

Protective Effect against Oxidative Stress in Medicinal Plant Extracts

International Nuclear Information System (INIS)

Kim, Jeong Hee; Lee, Eun Ju; Shin, Dong O; Hong, Sung Eun; Kim, Jin Kyu

2000-01-01

Protective effect of medicinal plant extracts against oxidative stress were screened in this study. Methanol extracts from 48 medicinal plants, which were reported to have antioxidative or anti-inflammatory effect were prepared and screened for their protective activity against chemically-induced and radiation-induced oxidative stress by using MTT assay. Thirty three samples showed protective activity against chemically-induced oxidative stress in various extent. Among those samples, extract of Glycyrrhiza uralensis revealed the strongest activity (25.9% at 100 μg/ml) with relatively lower cytotoxicity. Seven other samples showed higher than 20% protection at 100 μg/ml. These samples were tested for protection activity against radiation-induced oxidative stress. Methanol extract of Alpina officinarum showed the highest activity (17.8% at 20 μg/ml). Five fractions were prepared from the each 10 methanol extracts which showed high protective activity against oxidative stress. Among those fraction samples butanol fractions of Areca catechu var. dulcissima and Spirodela polyrrhiza showed the highest protective activities (78.8% and 77.2%, respectively, at 20 μg/ml)

Photocatalytic Ethanol Oxidative Dehydrogenation over Pt/TiO2: Effect of the Addition of Blue Phosphors

Directory of Open Access Journals (Sweden)

J. J. Murcia

2012-01-01

Full Text Available Ethanol oxidative dehydrogenation over Pt/TiO2 photocatalyst, in the presence and absence of blue phosphors, was performed. The catalyst was prepared by photodeposition of Pt on sulphated TiO2. This material was tested in a gas-solid photocatalytic fluidized bed reactor at high illumination efficiency. The effect of the addition of blue phosphors into the fluidized bed has been evaluated. The synthesized catalysts were extensively characterized by different techniques. Pt/TiO2 with a loading of 0.5 wt% of Pt appeared to be an active photocatalyst in the selective partial oxidation of ethanol to acetaldehyde improving its activity and selectivity compared to pure TiO2. In the same way, a notable enhancement of ethanol conversion in the presence of the blue phosphors has been obtained. The blue phosphors produced an increase in the level of ethanol conversion over the Pt/TiO2 catalyst, keeping at the same time the high selectivity to acetaldehyde.

Rhesus monkey lens as an in vitro model for studying oxidative stress

International Nuclear Information System (INIS)

Zigler, J.S. Jr.; Lucas, V.A.; Du, X.Y.

1989-01-01

Lenses from young rhesus monkeys were incubated in the presence of H 2 O 2 or oxygen radical generating systems to determine their suitability as a model for investigating lenticular oxidative stress. Additionally, direct comparisons were made between the effects found with the monkey lenses and those observed with cultured rat lenses exposed to the same oxidizing systems. As in earlier studies with rat lenses the monkey lenses exhibited impaired ability to actively accumulate from the medium radioactively labelled rubidium and choline following exposure to oxidative stress. Based on the effects of various scavengers of oxygen radicals it appeared that the mechanisms responsible for lens damage were the same for both rat and monkey lenses. However, rat lenses were damaged by lower concentrations of oxidants than were monkey lenses. It was concluded that oxidative stress affects both rat and monkey lenses by similar mechanisms but that lenses from monkeys, and probably other primates, are more resistant to these effects because they have better endogenous antioxidant defenses

Quantitative Appearance Inspection for Film Coated Tablets.

Science.gov (United States)

Yoshino, Hiroyuki; Yamashita, Kazunari; Iwao, Yasunori; Noguchi, Shuji; Itai, Shigeru

2016-01-01

The decision criteria for the physical appearance of pharmaceutical products are subjective and qualitative means of evaluation that are based entirely on human interpretation. In this study, we have developed a comprehensive method for the quantitative analysis of the physical appearance of film coated tablets. Three different kinds of film coated tablets with considerable differences in their physical appearances were manufactured as models, and their surface roughness, contact angle, color measurements and physicochemical properties were investigated as potential characteristics for the quantitative analysis of their physical appearance. All of these characteristics were useful for the quantitative evaluation of the physical appearances of the tablets, and could potentially be used to establish decision criteria to assess the quality of tablets. In particular, the analysis of the surface roughness and film coating properties of the tablets by terahertz spectroscopy allowed for an effective evaluation of the tablets' properties. These results indicated the possibility of inspecting the appearance of tablets during the film coating process.

Oxidative potential of particulate matter 2.5 as predictive indicator of cellular stress

International Nuclear Information System (INIS)

Crobeddu, Bélinda; Aragao-Santiago, Leticia; Bui, Linh-Chi; Boland, Sonja; Baeza Squiban, Armelle

2017-01-01

Particulate air pollution being recognized to be responsible for short and long term health effects, regulations for particulate matter with an aerodynamic diameter less than 2.5 (PM 2.5 ) are more and more restrictive. PM 2.5 regulation is based on mass without taking into account PM 2.5 composition that drives toxicity. Measurement of the oxidative potential (OP) of PM could be an additional PM indicator that would encompass the PM components involved in oxidative stress, the main mechanism of PM toxicity. We compared different methods to evaluate the intrinsic oxidative potential of PM 2.5 sampled in Paris and their ability to reflect the oxidative and inflammatory response in bronchial epithelial cells used as relevant target organ cells. The dithiothreitol depletion assay, the antioxidant (ascorbic acid and glutathione) depletion assay (OP AO ), the plasmid scission assay and the dichlorofluorescein (DCFH) oxidation assay used to characterize the OP of PM 2.5 (10–100 μg/mL) provided positive results of different magnitude with all the PM 2.5 samples used with significant correlation with different metals such as Cu and Zn as well as total polyaromatic hydrocarbons and the soluble organic fraction. The OP AO assay showed the best correlation with the production of intracellular reactive oxygen species by NCI-H292 cell line assessed by DCFH oxidation and with the expression of anti-oxidant genes (superoxide dismutase 2, heme-oxygenase-1) as well as the proinflammatory response (Interleukin 6) when exposed from 1 to 10 μg/cm 2 . The OP AO assay appears as the most prone to predict the biological effect driven by PM 2.5 and related to oxidative stress. - Highlights: • 5 Acellular assays were used to compare the intrinsic oxidative potential (OP) of PM. • The amount of ROS generation in bronchial cells is particle dependent. • Particles induce the expression of anti-oxidant and proinflammatory genes. • Biological effects correlates with OP assay

Surface morphology study on chromium oxide growth on Cr films by Nd-YAG laser oxidation process

International Nuclear Information System (INIS)

Dong Qizhi; Hu Jiandong; Guo Zuoxing; Lian Jianshe; Chen Jiwei; Chen Bo

2002-01-01

Grain sized (60-100 nm) Cr 2 O 3 thin films were prepared on Cr thin film surfaces by Nd-YAG laser photothermal oxidation process. Surface morphology study showed crack-free short plateau-like oxide films formed. Increase of dislocation density after pulsed laser irradiation was found. Thin film external surfaces, grain boundaries and dislocations are main paths of laser surface oxidation. Pinning and sealing of grain boundary was the reason that deeper oxidation did not produce. Grain growth and agglomeration of Cr sub-layer yielded tensile stress on the surface Cr 2 O 3 thin film. It was the reason that short plateau-like surface morphology formed and cracks appeared sometimes. In oxygen annealing at 700 deg. C, grain boundaries were considered not to be pinned at the surface, mixture diffusion was main mechanism in growth of oxide. Compression stress development in whole film led to extrusion of grains that was the reason that multiple appearances such as pyramid-like and nutshell-like morphology formed

Strong impacts on aerosol indirect effects from historical oxidant changes

Science.gov (United States)

Hafsahl Karset, Inger Helene; Koren Berntsen, Terje; Storelvmo, Trude; Alterskjær, Kari; Grini, Alf; Olivié, Dirk; Kirkevåg, Alf; Seland, Øyvind; Iversen, Trond; Schulz, Michael

2018-06-01

Uncertainties in effective radiative forcings through aerosol-cloud interactions (ERFaci, also called aerosol indirect effects) contribute strongly to the uncertainty in the total preindustrial-to-present-day anthropogenic forcing. Some forcing estimates of the total aerosol indirect effect are so negative that they even offset the greenhouse gas forcing. This study highlights the role of oxidants in modeling of preindustrial-to-present-day aerosol indirect effects. We argue that the aerosol precursor gases should be exposed to oxidants of its era to get a more correct representation of secondary aerosol formation. Our model simulations show that the total aerosol indirect effect changes from -1.32 to -1.07 W m-2 when the precursor gases in the preindustrial simulation are exposed to preindustrial instead of present-day oxidants. This happens because of a brightening of the clouds in the preindustrial simulation, mainly due to large changes in the nitrate radical (NO3). The weaker oxidative power of the preindustrial atmosphere extends the lifetime of the precursor gases, enabling them to be transported higher up in the atmosphere and towards more remote areas where the susceptibility of the cloud albedo to aerosol changes is high. The oxidation changes also shift the importance of different chemical reactions and produce more condensate, thus increasing the size of the aerosols and making it easier for them to activate as cloud condensation nuclei.

Effects of reading health and appearance exercise magazine articles on perceptions of attractiveness and reasons for exercise.

Directory of Open Access Journals (Sweden)

Melanie Pankratow

Full Text Available OBJECTIVE: To examine the effects of reading exercise-related magazine articles (health, appearance, or control and the moderating effects of exercise self-identity on reasons for exercise and perceptions of attractiveness, among women in first year university. An additional purpose was to use a thought listing technique, the results of which were examined for evidence of internalization of the exercise-related messages. PARTICIPANTS: Female students in their first year of studies between September 2010 and April 2011 (N = 173; mean age = 19.31 years, mean body mass index = 22.01. METHODS: Participants read a health, appearance, or control article, listed thoughts, and completed questionnaires measuring reasons for exercising, physical self-perception, and exercise self-identity. RESULTS: Participants in the health condition rated exercise for health significantly higher than control condition participants. Participants with high exercise self-identity rated attractiveness as a reason for exercising significantly higher than low exercise self-identity participants in both the health and appearance conditions. Participants with higher internalization scores (i.e., accepted societal norms of appearance reported exercising for attractiveness reasons more so than participants with lower internalization scores. CONCLUSIONS: The good news is that health messages may be influential and result in wanting to exercise for health purposes. However, exercising for attractiveness was rated highly by participants with high exercise identity who read either the health or appearance articles. Health and appearance are not necessarily distinct concepts for female undergraduate students and the media may influence cited reasons for exercise.

Copper-mediated oxidative degradation of catecholamines and oxidative damage of protein

Energy Technology Data Exchange (ETDEWEB)

Goncalves, P.R.; Harria, M.I.N.; Felix, J.M.; Hoffmann, M.E. [Universidade Estadual de Campinas, SP (Brazil). Inst. de Biologia

1997-12-31

Full text. Degradative oxidation of catecholamines has been a matter of large interest in recent years due to the evidences associating their autoxidation with the etiology of neurotoxic and cardiotoxic processes. In this work we present data on the degradative oxidation of catecholamines of physiological importance: isoproterenol (IP), epinephrine (EP), norepinephrine (NEP), deoxyepinephrine (DEP) and dopamine (DA). The degradative oxidation of the catecholamines was followed by measurement of spectral changes and oxygen consumption by neutral aqueous solutions. The data show that Cu{sup 2+} strongly accelerated the rate of catecholamine oxidation, following the decreasing order; EP>DEP>IP>NEP>DA. The production of superoxide anion radical during catecholamine oxidation was very slow, even in the presence of Cu{sup 2+}. The ability of IP to induce damages on bovine serum albumin (BSA) was determined by measuring the formation of carbonyl-groups in the protein, detected by reduction with tritiated Na BH{sub 4}. The incubation of BSA with IP (50-500{mu}M), in the presence of 100{mu}M Cu{sup 2+} leaded to an increased and dose dependent {sup 3} H-incorporation by the oxidized protein. The production of oxidative damage by IP/Cu{sup 2+} was accompanied by marked BSA fragmentation, detected by SDS-polyacrylamide gel dependent (25-400{mu}M IP) des appearance of the original BSA band and appearance of smaller fragments spread in the gel, when incubation has been done in the presence of 100{mu}M Cu{sup 2+}. These results suggest that copper-catalysed oxidative degradation of proteins induced by catecholamines might be critically involved in the toxic action of these molecules

Perceiving Direction of a Walker: Effect of Body Appearance

Directory of Open Access Journals (Sweden)

Kazuya Ono

2011-05-01

Full Text Available Human can perceive others' walking direction accurately even with 117ms observation (Sato, et al., ECVP2008. We aimed to see whether appearance of walker's body affects the accuracy of perceiving direction of the walker. Thus, we employed three different appearances: realistic human computer-graphics body (CG-human, nonrealistic cylinder-assembled body (Cylinders, and point-light walker (Points. We made a three-dimensional model of an adult-size walker who walked at a place. CG-human stimuli were generated by rendering the model with smooth shading. We made Cylinders stimuli by replacing body parts such as arms, legs, head, and hands with cylinders. Points stimuli were made by tracking 18 positions (mostly joints of the body like biological motion. One of walkers was presented for 117, 250, 500 or 1000ms while its direction was randomly varied by 3deg steps to 21deg left or right. Observers judged whether the walker was walking toward them (hit or not (miss, and self-range was measured in terms of the standard deviation for hit distributions. The perceived self-range was narrowed with long duration, and with CG-human stimulus. It is suggested that the accuracy of perceiving walker's direction depends on body appearance, and it is higher for human-like body than nonhuman body.

Heavy metals and manganese oxides in the genesee watershed, New York state: effects of geology and land use

Science.gov (United States)

Whitney, P.R.

1981-01-01

Manganese oxide coatings on gravels from 255 sites on tributary streams in the Genesee River Watershed were analyzed for Mn, Fe, Zn, Cd, Co, Ni, Pb, and Cu. The results were compared with data on bedrock geology, surficial geology and land use, using factor analysis and stepwise multiple regression. All metals except Pb show strong positive correlation with Mn. This association results from the well-known tendency of Mn oxide precipitates to adsorb and incorporate dissolved trace metals. Pb may be present in a separate phase on the gravel surfaces; alternatively Pb abundance may be so strongly influenced by environmental factors that the effect of varying abundance of the carrier phase becomes relatively unimportant. When the effects of varying Mn abundance are allowed for, Pb and to a lesser extent Zn and Cu abundances are seen to be related to commercial, industrial and residential land use. In addition to this pollution effect, all the trace metals, Cd and Ni most strongly, tend to be more abundant in oxide coatings from streams in the forested uplands in the southern part of the area. This probably reflects increased geochemical mobility of the metals in the more acid soils and groundwater of the southern region. A strong Zn anomaly is present in streams draining areas underlain by the Lockport Formation. Oxide coatings in these streams contain up to 5% Zn, originating from disseminated sphalerite in the Lockport and secondary Zn concentrations in the overlying muck soils. The same group of metals, plus calcium and loss on ignition, were determined in the silt and clay (minus 230 mesh) fraction of stream sediments from 129 of the same sites, using a hot nitric acid leach. The amounts of manganese in the sediments are low (average 1020 ppm) and manganese oxides are, at most, of relatively minor significance in the trace-metal geochemistry of these sediments. The bulk of the trace metals in sediment appears to be associated with iron oxides, clays and organic

Cycle oxidation behavior and anti-oxidation mechanism of hot-dipped aluminum coating on TiBw/Ti6Al4V composites with network microstructure.

Science.gov (United States)

Li, X T; Huang, L J; Wei, S L; An, Q; Cui, X P; Geng, L

2018-04-10

Controlled and compacted TiAl 3 coating was successfully fabricated on the network structured TiBw/Ti6Al4V composites by hot-dipping aluminum and subsequent interdiffusion treatment. The network structure of the composites was inherited to the TiAl 3 coating, which effectively reduces the thermal stress and avoids the cracks appeared in the coating. Moreover, TiB reinforcements could pin the TiAl 3 coating which can effectively improve the bonding strength between the coating and composite substrate. The cycle oxidation behavior of the network structured coating on 873 K, 973 K and 1073 K for 100 h were investigated. The results showed the coating can remarkably improve the high temperature oxidation resistance of the TiBw/Ti6Al4V composites. The network structure was also inherited to the Al 2 O 3 oxide scale, which effectively decreases the tendency of cracking even spalling about the oxide scale. Certainly, no crack was observed in the coating after long-term oxidation due to the division effect of network structured coating and pinning effect of TiB reinforcements. Interfacial reaction between the coating and the composite substrate occurred and a bilayer structure of TiAl/TiAl 2 formed next to the substrate after oxidation at 973 K and 1073 K. The anti-oxidation mechanism of the network structured coating was also discussed.

Differential requirement for nitric oxide in IGF-1-induced anti-apoptotic, anti-oxidant and anti-atherosclerotic effects

Science.gov (United States)

Sukhanov, Sergiy; Higashi, Yusuke; Shai, Shaw-Yung; Blackstock, Christopher; Galvez, Sarah; Vaughn, Charlotte; Titterington, Jane; Delafontaine, Patrick

2011-01-01

We have shown previously that insulin like-growth factor I (IGF-1) suppressed atherosclerosis in Apoe−/− mice and activated endothelial nitric oxide (NO) synthase. To determine whether IGF-1-induced atheroprotection depends on NO, IGF-1- or saline-infused mice were treated with L-NAME, the pan-NO synthase inhibitor or with D-NAME (control). IGF-1 reduced atherosclerosis in both the D-NAME and L-NAME groups suggesting that IGF-1’s anti-atherogenic effect was NO-independent. IGF-1 increased plaque smooth muscle cells, suppressed cell apoptosis and downregulated lipoprotein lipase and these effects were also NO-independent. On the contrary, IGF-1 decreased oxidative stress and suppressed TNF-α levels and these effects were blocked by L-NAME. Thus IGF-1’s anti-oxidant effect is dependent on its ability to increase NO but is distinct from its anti-atherosclerotic effect which is NO-independent. PMID:21872589

Effects of an oxidizing atmosphere in a spent fuel packaging facility

International Nuclear Information System (INIS)

Einziger, R.E.

1991-09-01

Sufficient oxidation of spent fuel can cause a cladding breach to propagate, resulting in dispersion of fuel particulates and gaseous radionuclides. The literature for spent fuel oxidation in storage and disposal programs was reviewed to evaluate the effect of an oxidizing atmosphere in a preclosure packaging facility on (1) physical condition of the fuel and (2) operations in the facility. Effects such as cladding breach propagation, cladding oxidation, rod dilation, fuel dispersal, 14 C and 85 Kr release, and crud release were evaluated. The impact of these effects, due to oxidation, upon a spent fuel handling facility is generally predicted to be less than the impact of similar effects due to fuel rod breached during handling in an inert-atmosphere facility. Preliminary temperature limits of 240 degree C and 227 degree C for a 2-week or 4-week handling period and 175 degree C for 2-year lag storage would prevent breach propagation and fuel dispersal. Additional data that are needed to support the assumptions in this analysis or complete the database were identified

Effects of titanium on a ferritic steel oxidation at 950 C

Energy Technology Data Exchange (ETDEWEB)

Issartel, C.; Buscail, H.; Caudron, E.; Cueff, R.; Riffard, F.; El Messki, S.; Karimi, N. [Lab. Vellave sur l' Elaboration et l' Etude des Materiaux (LVEEM), IUT de Clermont-Fd1 - Dept. de Chimie - Science des materiaux, Le Puy en Velay (France); Antoni, L. [CEA Grenoble, DTEN/SCSE/LHPAC (France)

2004-07-01

This work presents the titanium effect on the oxidation behaviour of chromia-forming alloys at 950 C. When the amount of titanium is high enough in the substrate, in situ XRD permit to show that this element reacts with oxygen to form Cr{sub 2}TiO{sub 5}. This oxide is quickly transformed into TiO{sub 2} during the first hours of oxidation. These oxides contribute to an increase of the mass gain registered. Titanium leads to a doping effect of the chromia layer inducing an increase of the cationic vacancies concentration and chromium diffusion. (orig.)

Oxidation kinetics and auger microprobe analysis of some oxidized zirconium alloys

International Nuclear Information System (INIS)

Ploc, R.A.

1989-01-01

Oxidation kinetics at 300 o C in dry oxygen of 0.5 wt% binary alloys of iron, nickel, and chromium in zirconium were determined for several surface preparations. Further, chemical profiles of the oxides as they existed on the matrix and on the precipitates were obtained by sputtering and Auger electron analysis. The appearance of 'breakaway' oxidation was controlled by the surface finish of the alloy, a variable that could be used to eliminate the phenomenon for all alloys except the Zr/Ni binary, which required β-quenching to accomplish the same purpose. (author)

Effects of tocopherols on oxidative stability of margarine

International Nuclear Information System (INIS)

Azizkhani, M.; Kamkar, A.; Nejad, A.S.M.

2011-01-01

Tocopherols are the most important natural antioxidants which are now added to edible oils. Each individual tocopherol (a, beta and gamma) was added to the oil phase of margarine in 0 (control), 100, 250, and 500 ppm. Anti oxidative activity was evaluated through oven test (at 60 +- 1 deg. C in 5 days and measuring peroxide value and anisidine value) and Ransimat test (110 +- 1 deg. C). Anti oxidative activity increased progressively as concentration of gamma-tocopherol increased. As the concentration of gamma-tocopherol increased from 0 to 100, and 250 ppm, oxidation of oil phase decreased. At 500 ppm, a-tocopherol acted as a prooxidant and gamma-tocopherol did not have any noticable effect, but gamma-tocopherol acted as an antioxidant. The order of anti oxidative activity of tocopherols was: a- < beta- < gamma-. (author)

Nb effect on Zr-alloy oxidation under high pressure steam at high temperatures

International Nuclear Information System (INIS)

Park, Kwangheon; Yang, Sungwoo; Kim, Kyutae

2005-01-01

The high-pressure steam effects on the oxidation of Zircaloy-4 (Zry-4) and Zirlo (Zry-1%Nb) claddings at high temperature have been analyzed. Test temperature range was 700-900degC, and pressures were 1-150 bars. High pressure-steam enhances oxidation of Zry-4, and the dependency of enhancement looks exponential to steam pressure. The origin of the oxidation enhancement turned out to be the formation of cracks in oxide. The loss of tetragonal phase by high-pressure steam seems related to the crack formation. Addition of Nb as an alloying element to Zr alloy reduces significantly the steam pressure effects on oxidation. The higher compressive stresses and the smaller fraction of tetragonal oxides in Zry-1%Nb seem to be the diminished effect of high-pressure steam on oxidation. (author)

An ecological momentary assessment of comparison target as a moderator of the effects of appearance-focused social comparisons.

Science.gov (United States)

Leahey, Tricia M; Crowther, Janis H

2008-09-01

This research examined whether comparison target moderates the effects of naturally occurring appearance-focused social comparisons on women's affect, appearance esteem, and dieting thoughts. During daily activities, body-satisfied (BS) women and body-dissatisfied (BD) women recorded their comparison targets and reactions to comparison information. For BS women, upward comparisons with peers were associated with more positive affect (PA) and appearance esteem and less guilt than upward comparisons with media images and downward comparisons with peers were associated with less PA than downward comparisons with media images. For BD women, upward comparisons with peers were associated with more appearance esteem and diet thoughts than upward comparisons with media images and downward comparisons with peers were associated with less PA, appearance esteem, and diet thoughts and more guilt than downward comparisons with media images.

Strong impacts on aerosol indirect effects from historical oxidant changes

Directory of Open Access Journals (Sweden)

I. H. H. Karset

2018-06-01

Full Text Available Uncertainties in effective radiative forcings through aerosol–cloud interactions (ERFaci, also called aerosol indirect effects contribute strongly to the uncertainty in the total preindustrial-to-present-day anthropogenic forcing. Some forcing estimates of the total aerosol indirect effect are so negative that they even offset the greenhouse gas forcing. This study highlights the role of oxidants in modeling of preindustrial-to-present-day aerosol indirect effects. We argue that the aerosol precursor gases should be exposed to oxidants of its era to get a more correct representation of secondary aerosol formation. Our model simulations show that the total aerosol indirect effect changes from −1.32 to −1.07 W m−2 when the precursor gases in the preindustrial simulation are exposed to preindustrial instead of present-day oxidants. This happens because of a brightening of the clouds in the preindustrial simulation, mainly due to large changes in the nitrate radical (NO3. The weaker oxidative power of the preindustrial atmosphere extends the lifetime of the precursor gases, enabling them to be transported higher up in the atmosphere and towards more remote areas where the susceptibility of the cloud albedo to aerosol changes is high. The oxidation changes also shift the importance of different chemical reactions and produce more condensate, thus increasing the size of the aerosols and making it easier for them to activate as cloud condensation nuclei.

Low nitrous oxide production in intermittent-feed high performance nitritating reactors

DEFF Research Database (Denmark)

Su, Qingxian; Jensen, Malene M.; Smets, Barth F.

Nitrous oxide (N2O) production from autotrophic nitrogen removal processes, especially nitritating systems, is of growing concern. N2O dynamics were characterized and N2O production factors were quantified in two lab-scale intermittent-feed nitritating SBRs. 93 ± 14% of the oxidized ammonium...... was converted to nitrite, with the average total net N2O production of 2.1 ± 0.7% of the ammonium oxidized. Operation with intermittent feeding appears an effective optimization approach to mitigate N2O emissions from nitritating systems. Net N2O production rates transiently increased with a rise in pH after...

Effect of preliminary oxidation on process of steel carburization

Energy Technology Data Exchange (ETDEWEB)

Devochkin, O V; Vorontsov, E S; Filonov, V N [Voronezhskij Politekhnicheskij Inst. (USSR)

1975-01-01

Effects of preliminary oxidation of the metal surface and its subsequent reduction steel cementation were studied. The samples with interferentionally coloured oxide film on the surface had deeper carbonated layer than those without film. The kinetics of carbonation process and the mechanism proposed for this phenomenon are given.

Effects of acute and chronic administration of methylprednisolone on oxidative stress in rat lungs

Directory of Open Access Journals (Sweden)

Ronaldo Lopes Torres

2014-06-01

Full Text Available Objective: To determine the effects of acute and chronic administration of methylprednisolone on oxidative stress, as quantified by measuring lipid peroxidation (LPO and total reactive antioxidant potential (TRAP, in rat lungs. Methods: Forty Wistar rats were divided into four groups: acute treatment, comprising rats receiving a single injection of methylprednisolone (50 mg/kg i.p.; acute control, comprising rats i.p. injected with saline; chronic treatment, comprising rats receiving methylprednisolone in drinking water (6 mg/kg per day for 30 days; and chronic control, comprising rats receiving normal drinking water. Results: The levels of TRAP were significantly higher in the acute treatment group rats than in the acute control rats, suggesting an improvement in the pulmonary defenses of the former. The levels of lung LPO were significantly higher in the chronic treatment group rats than in the chronic control rats, indicating oxidative damage in the lung tissue of the former. Conclusions: Our results suggest that the acute use of corticosteroids is beneficial to lung tissue, whereas their chronic use is not. The chronic use of methylprednisolone appears to increase lung LPO levels.

Effects of diet, packaging, and irradiation on protein oxidation, lipid oxidation, and color of raw broiler thigh meat during refrigerated storage.

Science.gov (United States)

Xiao, S; Zhang, W G; Lee, E J; Ma, C W; Ahn, D U

2011-06-01

This study was designed to evaluate the effects of dietary treatment, packaging, and irradiation singly or in combination on the oxidative stability of broiler chicken thigh meat. A total of 120 four-week-old chickens were divided into 12 pens (10 birds/pen), and 4 pens of broilers were randomly assigned to a control oxidized diet (5% oxidized oil) or an antioxidant-added diet [500 IU of vitamin E + 200 mg/kg of butylated hydroxyanisole (BHA)] and fed for 2 wk. After slaughter, thigh meats were separated, ground, packaged in either oxygen-permeable or oxygen-impermeable vacuum bags, and irradiated at 0 or 3 kGy. Lipid oxidation (TBA-reactive substances), protein oxidation (carbonyl), and color of the meat were measured at 1, 4, and 7 d of refrigerated storage. The lipid and protein oxidation of thigh meats from birds fed the diet supplemented with antioxidants (vitamin E + BHA) was significantly lower than the lipid and protein oxidation of birds fed the control diet, whereas the lipid and protein oxidation of broilers fed the oxidized oil diet was higher than that of birds fed the control diet. Vacuum packaging slowed, but irradiation accelerated, the lipid and protein oxidation of thigh meat during storage. Dietary antioxidants (vitamin E + BHA) and irradiation treatments showed a stronger effect on lipid oxidation than on protein oxidation. A significant correlation between lipid and protein oxidation in meat was found during storage. Dietary supplementation of vitamin E + BHA and the irradiation treatment increased the lightness and redness of thigh meat, respectively. It is suggested that appropriate use of dietary antioxidants in combination with packaging could be effective in minimizing oxidative changes in irradiated raw chicken thigh meat.

Influence of nutrition on liver oxidative metabolism.

Science.gov (United States)

Jorquera, F; Culebras, J M; González-Gallego, J

1996-06-01

The liver plays a major role in the disposition of the majority of drugs. This is due to the presence of several drug-metabolizing enzyme systems, including a group of membrane-bound mixed-function oxidative enzymes, mainly the cytochrome P450 system. Hepatic oxidative capacity can be assessed by changes in antipyrine metabolism. Different drugs and other factors may induce or inhibit the cytochrome P450-dependent system. This effect is important in terms of the efficacy or toxicity of drugs that are substrates for the system. Microsomal oxidation in animals fed with protein-deficient diets is depressed. The mixed-function oxidase activity recovers after a hyperproteic diet or the addition of lipids. Similar findings have been reported in patients with protein-calorie malnutrition, although results in the elderly are conflicting. Different studies have revealed that microsomal oxidation is impaired by total parenteral nutrition and that this effect is absent when changing the caloric source from carbohydrates to a conventional amino acid solution or after lipid addition, especially when administered as medium-chain/long-chain triglyceride mixtures. Peripheral parenteral nutrition appears to increase antipyrine clearance.

Halogen effect for improving high temperature oxidation resistance of Ti-50Al by anodization

Science.gov (United States)

Mo, Min-Hua; Wu, Lian-Kui; Cao, Hua-Zhen; Lin, Jun-Pin; Zheng, Guo-Qu

2017-06-01

The high temperature oxidation resistance of Ti-50Al was significantly improved via halogen effect which was achieved by anodizing in an ethylene glycol solution containing with fluorine ion. The anodized Ti-50Al with holes and micro-cracks could be self-repaired during oxidation at 1000 °C. The thickness of the oxide scale increases with the prolonging of oxidation time. On the basis of halogen effect for improving the high temperature oxidation resistance of Ti-50Al by anodization, only fluorine addition into the electrolyte can effectively improve the high temperature oxidation resistance of Ti-50Al.

Effects of oxidation in the mechanical behavior of zircaloy-4 tubes

International Nuclear Information System (INIS)

Santos, A.M.M. dos.

1981-07-01

The kinetics of oxidation of zircaloy-4 is isothermally studied utilizing discontinous gravimetric method under two different oxidizing conditions, using gaseous oxigen and steam. The total weight gain during oxidation occurs in two different way: formation of oxide and solid solution. A mechanical test for studying the effect of embrittlement due to the absorption of oxygen in small zircalloy tubes have been developed. (Author) [pt

Broadband dielectric spectroscopy of oxidized porous silicon

International Nuclear Information System (INIS)

Axelrod, Ekaterina; Urbach, Benayahu; Sa'ar, Amir; Feldman, Yuri

2006-01-01

Dielectric measurements accompanied by infrared absorption and photoluminescence (PL) spectroscopy were used to investigate the electrical and optical properties of oxidized porous silicon (PS). As opposed to non-oxidized PS, only high temperature relaxation processes could be resolved for oxidized PS. Two relaxation processes have been observed. The first process is related to dc-conductivity that dominates at high temperatures and low frequencies. After subtraction of dc-conductivity we could analyse a second high-temperature relaxation process that is related to interface polarization induced by charge carriers trapped at the host matrix-pore interfaces. We found that, while the main effect of the oxidation on the PL appears to be a size reduction in the silicon nanocrystals that gives rise to a blue shift of the PL spectrum, its main contribution to the dielectric properties turns out to be blocking of transport channels in the host tissue and activation of hopping conductivity between silicon nanocrystals

Broadband dielectric spectroscopy of oxidized porous silicon

Energy Technology Data Exchange (ETDEWEB)

Axelrod, Ekaterina [Department of Applied Physics, Hebrew University of Jerusalem, Jerusalem, 91904 (Israel); Urbach, Benayahu [Racah Institute of Physics and the Center for Nanoscience and Nanotechnology, Hebrew University of Jerusalem, Jerusalem, 91904 (Israel); Sa' ar, Amir [Racah Institute of Physics and the Center for Nanoscience and Nanotechnology, Hebrew University of Jerusalem, Jerusalem, 91904 (Israel); Feldman, Yuri [Department of Applied Physics, Hebrew University of Jerusalem, Jerusalem, 91904 (Israel)

2006-04-07

Dielectric measurements accompanied by infrared absorption and photoluminescence (PL) spectroscopy were used to investigate the electrical and optical properties of oxidized porous silicon (PS). As opposed to non-oxidized PS, only high temperature relaxation processes could be resolved for oxidized PS. Two relaxation processes have been observed. The first process is related to dc-conductivity that dominates at high temperatures and low frequencies. After subtraction of dc-conductivity we could analyse a second high-temperature relaxation process that is related to interface polarization induced by charge carriers trapped at the host matrix-pore interfaces. We found that, while the main effect of the oxidation on the PL appears to be a size reduction in the silicon nanocrystals that gives rise to a blue shift of the PL spectrum, its main contribution to the dielectric properties turns out to be blocking of transport channels in the host tissue and activation of hopping conductivity between silicon nanocrystals.

Effects of inorganic carbon on the nitrous oxide emissions and microbial diversity of an anaerobic ammonia oxidation reactor.

Science.gov (United States)

Zhang, Wenjie; Wang, Dunqiu; Jin, Yue

2018-02-01

Inorganic carbon (IC) is important for anaerobic ammonium oxidation (anammox). In this study, the effects of the IC concentration on N 2 O emissions and microbial diversity in an anammox reactor were investigated. N 2 O emissions were positively correlated with IC concentrations, and IC concentrations in the range of 55-130 mg/L were optimal, considering the nitrogen removal rate and N 2 O emissions. High IC concentrations resulted in the formation of CaCO 3 on the surface of anammox granules, which impacted the diffusion conditions of the substrate. Microbial community analysis indicated that high IC concentrations decreased the populations of specific bacteria, such as Achromobacter spanius strain YJART-7, Achromobacter xylosoxidans strain IHB B 6801, and Denitratisoma oestradiolicum clone 20b_15. D. oestradiolicum clone 20b_15 appeared to be the key contributor to N 2 O emissions. High N 2 O emissions may result from changes in organic carbon sources, which lead to denitrification by D. oestradiolicum clone 20b_15. Copyright © 2017 Elsevier Ltd. All rights reserved.

In vitro potential cytogenetic and oxidative stress effects of roxithromycin.

Science.gov (United States)

Arslan, Mehmet; Timocin, Taygun; Ila, Hasan B

2017-10-01

Macrolide antibiotic roxithromycin was evaluated in terms of its genotoxic, cytotoxic and oxidative stress effects. For this purpose; 25, 50, 100 and 200 μg/mL concentrations of roxithromycin were dissolved in dimethyl sulfoxide and treated to human peripheral blood lymphocytes for two different treatment periods (24 and 48 h). In chromosome aberration (CA) and micronucleus (MN) tests, roxithromycin did not show genotoxic effect. But it induced sister chromatid exchange (SCE) at the highest concentration (200 μg/mL) for the 24-h treatment period and at all concentrations (except 25 μg/mL) for the 48-h treatment period. Looking at cytotoxic effect of roxithromycin, statistically insignificant decreases on mitotic index and proliferation index were observed. Roxithromycin decreased nuclear division index (NDI) at highest two concentrations (100 and 200 μg/mL) for the 24-h treatment period and at all concentrations (expect 25 μg/mL) for the 48-h treatment period. Total oxidant values, total antioxidant values and oxidative stress index did not change with roxithromycin treatment. Eventually, roxithromycin did not have genotoxic and oxidative stress effects in human-cultured lymphocytes.

On Multiple Appearances

DEFF Research Database (Denmark)

Bork Petersen, Franziska

2012-01-01

reduction and epoché to focus on how dancing bodies appear in a stage context. To test these tools’ ability to explore dancing bodies from a third-person perspective, I analyse the Danish choreographer Kitt Johnson’s solo performance Drift (2011) - focussing on her shifting physical appearance. While...... phenomenology helps me to describe the multiple and radically different guises that Johnson assumes in her piece, my analysis, ultimately, does not aim to distil a truer, more real being from her appearances as is often the case in phenomenological philosophy. I complement my analytical approach...... with the Deleuzian notion of becoming animal and suggest that Johnson stages what could, in Judith Butler’s terms, be called a critical contingency of bodily appearance....

The effect of substrate texture and oxidation temperature on oxide texture development in zirconium alloys

Energy Technology Data Exchange (ETDEWEB)

Garner, A., E-mail: alistair.garner@manchester.ac.uk [Materials Performance Centre, University of Manchester, Grosvenor Street, Manchester, M17HS (United Kingdom); Frankel, P. [Materials Performance Centre, University of Manchester, Grosvenor Street, Manchester, M17HS (United Kingdom); Partezana, J. [Westinghouse Electric Company, 1332 Beulah Road, Pittsburgh, PA 15235 (United States); Preuss, M. [Materials Performance Centre, University of Manchester, Grosvenor Street, Manchester, M17HS (United Kingdom)

2017-02-15

During corrosion of zirconium alloys a highly textured oxide is formed, the degree of this preferred orientation has previously been shown to be an important factor in determining the corrosion behaviour of these alloys. Two distinct experiments were designed in order to investigate the origin of this oxide texture development on two commercial alloys. Firstly, sheet samples of Zircaloy-4 were oxidised between 500 and 800 °C in air. The resulting monoclinic oxide texture strength was observed to decrease with increasing oxidation temperature. In a second experiment, orthogonal faces of Low Tin ZIRLO{sub ™} were oxidised in 360 °C water, providing different substrate textures but identical microstructures. The substrate texture was observed to have a negligible effect on the corrosion performance whilst the major orientation of both oxide phases was found to be independent of substrate orientation. It is concluded that the main driving force for oxide texture development in single-phase zirconium alloys is the compressive stress caused by the Zr−ZrO{sub 2} transformation. - Highlights: • Substrate orientation does not significantly affect oxide texture development. • Corrosion performance is independent of substrate texture. • Monoclinic oxide texture strength decreases with increasing oxidation temperature. • The main driving force for texture development is the oxidation-induced stress.

Effects of gender, media influences, and traditional gender role orientation on disordered eating and appearance concerns among Latino adolescents.

Science.gov (United States)

Lopez, Vera; Corona, Rosalie; Halfond, Raquel

2013-08-01

This study examined the main and interaction effects of gender, traditional gender role orientation, and media-influenced sociocultural values and ideals about appearance in a sample of 96 Latino adolescents controlling for age, country of origin, and BMI. Girls and less traditionally oriented youth reported significantly more disordered eating and appearance concerns than did boys and more traditionally oriented youth. Gender moderated the relationship between traditional gender role orientation and disordered eating and appearance concerns. Contrary to our hypothesis, media-influenced sociocultural values and ideals about appearance did not significantly predict disordered eating and appearance concerns. However, the interaction between gender and sociocultural values and ideals about appearance was significant. Our findings highlight the importance of continued research on gender, media, and cultural influences as they relate to disordered eating and appearance concerns among Latino youth. Copyright © 2013 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Examination of several pre-oxidation procedures and their effect as hydrogen permeation-barrier

International Nuclear Information System (INIS)

Heimes, E.

1986-03-01

Several pre-oxidation procedures have been tested with respect to their effect as a hydrogen permeation barrier at the high temperature alloys Hastelloy X and Inconel 617. By outside coating of Hastelloy X samples with alumina the determined impeding effects were very low. A surface aluminium enrichment by different procedures were accomplished before selective oxidation. The method of Aluminium-Hot-Dipping generated oxide layers with a four- to fivefold higher impeding effect compared to specimens fabricated by a standard procedure. With the aid of a metallographical follow-up examination it was shown that the higher impeding effects are due to an improved adhesion between the oxide layer and the high temperature material, whereby in the cooling period after manufacturing a smaller amount of oxide cracking is obtainable. (orig./PW) [de

Unintended inhalation of nitric oxide by contamination of compressed air: physiologic effects and interference with intended nitric oxide inhalation in acute lung injury.

Science.gov (United States)

Benzing, A; Loop, T; Mols, G; Geiger, K

1999-10-01

Compressed air from a hospital's central gas supply may contain nitric oxide as a result of air pollution. Inhaled nitric oxide may increase arterial oxygen tension and decrease pulmonary vascular resistance in patients with acute lung injury and acute respiratory distress syndrome. Therefore, the authors wanted to determine whether unintentional nitric oxide inhalation by contamination of compressed air influences arterial oxygen tension and pulmonary vascular resistance and interferes with the therapeutic use of nitric oxide. Nitric oxide concentrations in the compressed air of a university hospital were measured continuously by chemiluminescence during two periods (4 and 2 weeks). The effects of unintended nitric oxide inhalation on arterial oxygen tension (n = 15) and on pulmonary vascular resistance (n = 9) were measured in patients with acute lung injury and acute respiratory distress syndrome by changing the source of compressed air of the ventilator from the hospital's central gas supply to a nitric oxide-free gas tank containing compressed air. In five of these patients, the effects of an additional inhalation of 5 ppm nitric oxide were evaluated. During working days, compressed air of the hospital's central gas supply contained clinically effective nitric oxide concentrations (> 80 parts per billion) during 40% of the time. Change to gas tank-supplied nitric oxide-free compressed air decreased the arterial oxygen tension by 10% and increased pulmonary vascular resistance by 13%. The addition of 5 ppm nitric oxide had a minimal effect on arterial oxygen tension and pulmonary vascular resistance when added to hospital-supplied compressed air but improved both when added to tank-supplied compressed air. Unintended inhalation of nitric oxide increases arterial oxygen tension and decreases pulmonary vascular resistance in patients with acute lung injury and acute respiratory distress syndrome. The unintended nitric oxide inhalation interferes with the

Optical appearance of distant galaxies

International Nuclear Information System (INIS)

Pritchet, C.; Kline, M.I.

1981-01-01

We have used the recent evolutionary and K-corrections of Bruzual and Kron to predict the optical appearance of galaxies spanning a wide range of magnitudes and redshifts. It is found that nearly all galaxies with J< or approx. =25 are resolved in 1-arcsec seeing. At fixed apparent magnitude, galaxies with large redshifts are more diffuse in appearance than those at small z. This fact causes the most distant galaxies at any magnitude level to be missed, and, depending on the measurement algorithm employed, may cause the luminosities of detected galaxies to be seriously underestimated. Both of these effects deserve consideration when attempting to interpret number counts of faint galaxies. Observations made with the Space Telescope are expected to resolve nearly all galaxies at J< or approx. =27.5; however, several factors conspire to render Space Telescope observations less effective than certain ground-based CCD observations for the optical detection of distant galaxies. Finally, we note that most of our conclusions are unaffected by changes in the assumed cosmology

The origin of traps and the effect of nitrogen plasma in oxide-nitride-oxide structures for non-volatile memories

International Nuclear Information System (INIS)

Kim, W. S.; Kwak, D. W.; Oh, J. S.; Lee, D. W.; Cho, H. Y.

2010-01-01

Ultrathin oxide-nitride-oxide (ONO) dielectric stacked layers are fundamental structures of silicon-oxide-nitride-oxide-silicon (SONOS) non-volatile memory devices in which information is known to be stored as charges trapped in silicon nitride. Deep-level transient spectroscopy (DLTS) and a capacitance-voltage (CV) analysis were introduced to observe the trap behavior related to the memory effect in memory devices. The DLTS results verified that the nitride-related traps were a dominant factor in the memory effect. The energy of hole traps was 0.307 eV above the balance band. To improve the memory effects of the non-volatile memory devices with ONO structures, we introduced a nitrogen plasma treatment. After the N-plasma treatment, the flat-band voltage shift (ΔV FB ) was increased by about 1.5 times. The program and the erase (P-E) characteristics were also shown to be better than those for the as-ONO structure. In addition, the retention characteristics were improved by over 2.4 times.

Geometric Evaluation of the Effect of Prosthetic Rehabilitation on the Facial Appearance of Mandibulectomy Patients: A Preliminary Study.

Science.gov (United States)

Aswehlee, Amel M; Elbashti, Mahmoud E; Hattori, Mariko; Sumita, Yuka I; Taniguchi, Hisashi

The purpose of this study was to geometrically evaluate the effect of prosthetic rehabilitation on the facial appearance of mandibulectomy patients. Facial scans (with and without prostheses) were performed for 16 mandibulectomy patients using a noncontact three-dimensional (3D) digitizer, and 3D images were reconstructed with the corresponding software. The 3D datasets were geometrically evaluated and compared using 3D evaluation software. The mean difference in absolute 3D deviations for full face scans was 382.2 μm. This method may be useful in evaluating the effect of conventional prostheses on the facial appearance of individuals with mandibulectomy defects.

Effect of antioxidant on biodiesel properties under accelerated oxidation

Energy Technology Data Exchange (ETDEWEB)

Silva, Adriano Sant' ana; Carvalho, Maria Wilma N.C.; Silva, Flavio Luiz Honorato da; Lima, Ezenildo Emanuel de [Universidade Federal de Campina Grande (CCT/UFCG), PB (Brazil). Centro de Ciencia e Tecnologia; Silva, Everson de Lima [Universidade Estadual de Campinas (FEAGRI/UNICAMP), SP (Brazil). Fac. de Engenharia Agricola; Dantas, Hermeval Jales [Universidade Federal de Campina Grande (CTRN/UFCG), PB (Brazil). Centro de Tecnologia e Recursos Naturais

2008-07-01

This work aimed to study the effect of antioxidant tert-butyl hydroquinone (TBHQ) on oxidative stability of biodiesel. The effect of antioxidant was analyzed under aspects such as acid value, specific gravity, dynamic viscosity and FTIR spectroscopy. According to the results, the degraded samples treated with antioxidant presented the lowest values for acid value, specific mass and dynamic viscosity. FTIR spectra showed that the degraded samples treated with antioxidant have increased their oxidative stability, while those without antioxidant had an increase in the stretch band of hydroxyl (OH). (author)

Effects of an Appearance-Focused Interpretation Training Intervention on Eating Disorder Symptoms.

Science.gov (United States)

Summers, Berta J; Cougle, Jesse R

2018-03-13

Previous research suggests that computerized interpretation bias modification (IBM) techniques may be useful for modifying thoughts and behaviours relevant to eating pathology; however, little is known about the utility of IBM for decreasing specific eating disorder (ED) symptoms (e.g. bulimia, drive for thinness). The current study sought to further examine the utility of IBM for ED symptoms via secondary analyses of an examination of IBM for individuals with elevated body dysmorphic disorder (BDD) symptoms (see Summers and Cougle, 2016), as these disorders are both characterized by threat interpretation biases of ambiguous appearance-related information. We recruited 41 participants for a randomized trial comparing four sessions of IBM aimed at modifying problematic social and appearance-related threat interpretation biases with a placebo control training (PC). At 1-week post-treatment, and relative to the PC, the IBM group reported greater reductions in negative/threat interpretations of ambiguous information in favour of positive/benign biases. Furthermore, among individuals with high pre-treatment bulimia symptoms, IBM yielded greater reductions in bulimia symptoms compared with PC at post-treatment. No treatment effects were observed on drive for thinness symptoms. The current study suggests that cognitive interventions for individuals with primary BDD symptoms may improve co-occurring ED symptoms such as bulimia.

Memory colours affect colour appearance.

Science.gov (United States)

Witzel, Christoph; Olkkonen, Maria; Gegenfurtner, Karl R

2016-01-01

Memory colour effects show that colour perception is affected by memory and prior knowledge and hence by cognition. None of Firestone & Scholl's (F&S's) potential pitfalls apply to our work on memory colours. We present a Bayesian model of colour appearance to illustrate that an interaction between perception and memory is plausible from the perspective of vision science.

Amphoteric oxide semiconductors for energy conversion devices: a tutorial review.

Science.gov (United States)

Singh, Kalpana; Nowotny, Janusz; Thangadurai, Venkataraman

2013-03-07

In this tutorial review, we discuss the defect chemistry of selected amphoteric oxide semiconductors in conjunction with their significant impact on the development of renewable and sustainable solid state energy conversion devices. The effect of electronic defect disorders in semiconductors appears to control the overall performance of several solid-state ionic devices that include oxide ion conducting solid oxide fuel cells (O-SOFCs), proton conducting solid oxide fuel cells (H-SOFCs), batteries, solar cells, and chemical (gas) sensors. Thus, the present study aims to assess the advances made in typical n- and p-type metal oxide semiconductors with respect to their use in ionic devices. The present paper briefly outlines the key challenges in the development of n- and p-type materials for various applications and also tries to present the state-of-the-art of defect disorders in technologically related semiconductors such as TiO(2), and perovskite-like and fluorite-type structure metal oxides.

Effects of Borax on the Reduction of Pre-oxidized Panzhihua Ilmenite

Science.gov (United States)

Guo, Yufeng; Zheng, Fuqiang; Jiang, Tao; Chen, Feng; Wang, Shuai; Qiu, Guanzhou

2018-01-01

The effects of borax (sodium borate) on the enhancement reduction of pre-oxidized Panzhihua ilmenite were investigated. The effects of borax on the mineral phase transformation, microstructures, crystal cell parameter, melting point and Mg distribution were studied to reveal the mechanism of enhancement reduction. Under the constant reduction conditions, the borax could reduce the reduction activation energy of pre-oxidized ilmenite. The reduction kinetics analysis indicated that the reduction rate was controlled by interfacial chemical reaction. The reduction activation energy of the pre-oxidized ilmenite with 4% borax was 80.263 kJ/mol, which was 28.585 kJ/mol less than that of the pre-oxidized ilmenite without borax. Borax could eliminate the migration of Mg into the reduced particle center. The crystal cell parameter of the reduced product was increased by adding borax. Borax could improve the growth of dendritic crystals in the pre-oxidized ilmenite.

Greenhouse effect due to atmospheric nitrous oxide

Science.gov (United States)

Yung, Y. L.; Wang, W. C.; Lacis, A. A.

1976-01-01

The greenhouse effect due to nitrous oxide in the present atmosphere is about 0.8 K. Increase in atmospheric N2O due to perturbation of the nitrogen cycle by man may lead to an increase in surface temperature as large as 0.5 K by 2025, or 1.0 K by 2100. Other climatic effects of N2O are briefly discussed.

Heterogeneous nucleation of calcium oxalate on native oxide surfaces

International Nuclear Information System (INIS)

Song, L.; Pattillo, M.J.; Graff, G.L.; Campbell, A.A.; Bunker, B.C.

1994-04-01

The aqueous deposition of calcium oxalate onto colloidal oxides has been studied as a model system for understanding heterogeneous nucleation processes of importance in biomimetic synthesis of ceramic thin films. Calcium oxalate nucleation has been monitored by measuring induction times for nucleation using Constant Composition techniques and by measuring nucleation densities on extended oxide surfaces using an atomic force microscope. Results show that the dependence of calcium oxalate nucleation on solution supersaturation fits the functional form predicted by classical nucleation theories. Anionic surfaces appear to promote nucleation better than cationic surfaces, lowering the effective energy barrier to heterogeneous nucleation

At first glance: social meanings of dental appearance.

Science.gov (United States)

Eli, I; Bar-Tal, Y; Kostovetzki, I

2001-01-01

An important factor in social interaction is physical appearance. Major elements in the evaluation of physical appearance are the mouth and teeth. The purpose of this study was to evaluate the effect of tooth appearance on the development of a first impression of the other person, with regard to the sex of both the respondent and the target. Eight facial photographs of individuals with intact upper teeth were manipulated: one set was left untouched and the other was professionally altered so that the front anterior teeth appeared decayed. The photographs were randomly aligned in sets of eight, each set consisting of four individuals with an original, intact dentition and four other individuals with a "decayed" dentition. The sets of photographs were then presented to 115 respondents (65 males and 50 females). Evaluations were made according to three categories of traits--esthetic, social, and professional. For all three evaluation categories, the difference in scores between decayed and intact dentition given to targets were significantly higher when participants of one sex evaluated targets of the opposite sex, as compared to evaluating targets of their own sex. The effect of tooth appearance on the physical attractiveness stereotype is more evident when males evaluate females and vice versa, rather than when evaluating their own sex.

Effect of salting on back fat hydrolysis and oxidation

Science.gov (United States)

Tunieva, E. К; Nasonova, V. V.; Stanovova, I. A.; Spiridonov, К I.; Kurzova, A. A.

2017-09-01

Technological factors significantly affect the rate of hydrolytic and oxidative changes in fat. The aim of the research was to study the effect of sodium chloride on hydrolysis and oxidation of fat raw material, including the impact of thermal treatment. Back fat was minced, sodium chloride was added (in amounts of 0.0, 2.0, 3.5 or 5.0%), then it was thermally treated or not. Determination of the acid value (AV) was carried out by titration with aqueous potassium hydroxide of free fatty acids in the ether-alcohol solution of back fat; the peroxide value (PV) was based on oxidation of iodhydric acid with peroxides contained in fat followed by titration of released iodine with sodium thiosulphate. The thiobarbituric acid value (TBAV) was determined by the development of stained substances due to interaction of fat oxidation products with 2-thiobarbituric acid and measurement of color intensity using a spectrophotometer. Adding 5.0% sodium chloride to back fat led to a 30.1% decrease in AV. Addition of 2.0% sodium chloride inhibited the development of the oxidation products and led to a 17% decrease in the PV and to a 25% decrease in TBAV (p0.05). The results obtained showed an ambiguous effect of sodium chloride on the processes of fat oxidation, depending on dosage and the use of thermal treatment, justifying the necessity to develop approaches that allow reduction of the sodium chloride content in meat products that are not subjected to thermal treatment.

Comparing the effects of cryotherapy with nitrous oxide gas versus topical corticosteroids in the treatment of oral lichen planus.

Science.gov (United States)

Amanat, Dariush; Ebrahimi, Hooman; Zahedani, Maryam Zahed; Zeini, Nasim; Pourshahidi, Sara; Ranjbar, Zahra

2014-01-01

Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa with treatment challenges for clinicians. The objective of this study is to compare the effects of cryotherapy as a new modality with topical corticosteroids as a conventional therapy in the treatment of OLP. Thirty patients with bilateral OLP lesions were selected. From each patient a lesion on one side was chosen randomly for a single session of cryotherapy with nitrous oxide gas and the lesion on the other side received triamcinolone acetonide 0.1% ointment in orabase. Treatment outcome was measured by means of an appearance score, pain score (visual analogue scale), and severity of lesions before treatment and after 2, 4 and 6 weeks of treatment. Paired samples t-test and Wilcoxon test. In both methods of treatment sign score, pain score and severity of lesions was significantly reduced in all follow-up sessions (Ptreatment outcome and relapse was not significantly different between the two treatment methods (P>0.05). Cryotherapy with nitrous oxide gas is as effective as topical triamcinolone acetonide in the treatment of OLP with no systemic side effects and needs less patient compliance. It can be considered as an alternative or adjuvant therapy in OLP patients to reduce the use of treatments with adverse effects.

Effect of thyroid function on LDL oxidation.

Science.gov (United States)

Costantini, F; Pierdomenico, S D; De Cesare, D; De Remigis, P; Bucciarelli, T; Bittolo-Bon, G; Cazzolato, G; Nubile, G; Guagnano, M T; Sensi, S; Cuccurullo, F; Mezzetti, A

1998-05-01

In this study, the effect of different levels of thyroid hormone and metabolic activity on low density lipoprotein (LDL) oxidation was investigated. Thus, in 16 patients with hyperthyroidism, 16 with hypothyroidism, and 16 age- and sex-matched healthy normolipidemic control subjects, the native LDL content in lipid peroxides, vitamin E, beta-carotene, and lycopene, as well as the susceptibility of these particles to undergo lipid peroxidation, was assessed. Hyperthyroidism was associated with significantly higher lipid peroxidation, as characterized by a higher native LDL content in lipid peroxides, a lower lag phase, and a higher oxidation rate than in the other two groups. This elevated lipid peroxidation was associated with a lower LDL antioxidant concentration. Interestingly, hypothyroid patients showed an intermediate behavior. In fact, in hypothyroidism, LDL oxidation was significantly lower than in hyperthyroidism but higher than in the control group. Hypothyroidism was also characterized by the highest beta-carotene LDL content, whereas vitamin E was significantly lower than in control subjects. In hyperthyroidism but not in the other two groups, LDL oxidation was strongly influenced by free thyroxine blood content. In fact in this group, the native LDL lipid peroxide content and the lag phase were directly and indirectly, respectively, related to free thyroxine blood levels. On the contrary, in hypothyroidism LDL oxidation was strongly and significantly related to serum lipids. In conclusion, both hypothyroidism and hyperthyroidism are characterized by higher levels of LDL oxidation when compared with normolipidemic control subjects. In hyperthyroid patients, the increased lipid peroxidation was strictly related to free thyroxine levels, whereas in hypothyroidism it was strongly influenced by serum lipids.

High-temperature steam-oxidation behavior of Zr-1Nb-1Sn-0.1Fe cladding tube at temperatures of 800-1000

International Nuclear Information System (INIS)

Lee, Cheol Min; Cho, Tae Won; Jeong, Gwan Yoon; Kim, Mi Jin; Kim, Ji Hyeon; Lee, Hee Jae; Sohn, Dong Seong; Mok, Yong Kyoon

2016-01-01

To prevent cladding failure, NRC issued a regulation Title 10 § 50.46, which specifies cladding temperature of 1204 .deg. C and 17% ECR should not be exceeded. The fundamental reason of the mechanical degradation of cladding is the formation of the oxide which is brittle. Theoretically, the oxide layer is formed following parabolic rate. However, from many experiments, sub-parabolic rates are often observed. There have been many suggestions so far; chemical and stress gradient across the oxide layer could initiate the sub-parabolic rate, the phase transformation of Zirconium dioxide from tetragonal to monoclinic could be the reason, change of the grain size of Zirconium dioxide could cause the cubic oxidation rate, and there is a suggestion that if electron migration is the major mechanism of the oxide growth, then the subparabolic rate can show up. However, the reason why the sub-parabolic rate appears is still not certain. Another important degradation mechanism is breakaway oxidation. A clear explanation that why the breakaway oxidation appears is still not clear. Most of the people believe the phase transformation of Zirconium dioxide cause instability within the oxide, which causes breakaway oxidation to appear. However, how much effect is caused from the phase transformation is not so sure. In this study, detailed analysis about the oxidation kinetics and the breakaway oxidation of Zr-1Nb-1Sn- 0.1Fe were carried out at temperatures between 800 - 1000 .deg. C.

Iron Oxide Minerals in Atmospheric Dust and Source Sediments-Studies of Types and Properties to Assess Environmental Effects

Science.gov (United States)

Reynolds, R. L.; Goldstein, H. L.; Moskowitz, B. M.; Till, J. L.; Flagg, C.; Kokaly, R. F.; Munson, S.; Landry, C.; Lawrence, C. R.; Hiza, M. M.; D'Odorico, P.; Painter, T. H.

2011-12-01

Ferric oxide minerals in atmospheric dust can influence atmospheric temperatures, accelerate melting of snow and ice, stimulate marine phytoplankton productivity, and impact human health. Such effects vary depending on iron mineral type, size, surface area, and solubility. Generally, the presence of ferric oxides in dust is seen in the red, orange, or yellow hues of plumes that originate in North Africa, central and southwest Asia, South America, western North America, and Australia. Despite their global importance, these minerals in source sediments, atmospheric dust, and downwind aeolian deposits remain poorly described with respect to specific mineralogy, particle size and surface area, or presence in far-traveled aerosol compounds. The types and properties of iron minerals in atmospheric dust can be better understood using techniques of rock magnetism (measurements at 5-300 K), Mössbauer and high-resolution visible and near-infrared reflectance spectroscopy; chemical reactivity of iron oxide phases; and electron microscopy for observing directly the ferric oxide coatings and particles. These studies can elucidate the diverse environmental effects of iron oxides in dust and can help to identify dust-source areas. Dust-source sediments from the North American Great Basin and Colorado Plateau deserts and the Kalahari Desert, southern Africa, were used to compare average reflectance values with a magnetic parameter (hard isothermal remanent magnetization, HIRM) for ferric oxide abundance. Lower reflectance values correspond strongly with higher HIRM values, indicating that ferric oxides (hematite or goethite, or both) contribute to absorption of solar radiation in these sediments. Dust deposited to snow cover of the San Juan Mountains (Colorado) and Wasatch Mountains (Utah) was used to characterize dust composition compared with properties of sediments exposed in source-areas identified from satellite retrievals. Results from multiple methods indicate that

Formation and effect of orientation domains in layered oxide cathodes of lithium-ion batteries

International Nuclear Information System (INIS)

Jarvis, Karalee A.; Wang, Chih-Chieh; Knight, James C.; Rabenberg, Lew; Manthiram, Arumugam; Ferreira, Paulo J.

2016-01-01

We show that in layered oxides that are employed as cathodes in lithium-ion batteries, the cation layers can order on different {111} NaCl planes within a single particle, which makes the lithium layer discontinuous across a particle. The findings challenge previous assertions that lithium undergoes 2-D diffusion in layered oxides and the data provide new insights into the decrease in rate capabilities for some layered oxides. Therefore, it is critically important to understand how these discontinuities form and how the loss of 2-D diffusion impacts the overall performance of the layered oxide cathode materials. Employing X-ray diffraction (XRD) and aberration-corrected scanning transmission electron microscopy (STEM), we find that as the material transitions from a disordered to an ordered state, it forms four orientation variants corresponding to the four {111} NaCl planes. This transition is not intrinsic to all layered oxides and appears to be more strongly affected by nickel. Furthermore, with energy dispersive spectroscopy (EDS), we show that there is an increase in the nickel concentration at the interface between each orientation variant. This reduces the rate of lithium diffusion, negatively affects the rate capability, and could be contributing to the overall capacity fade.

Effects of sucrose on rFVIIa aggregation and methionine oxidation

DEFF Research Database (Denmark)

Soenderkaer, Susanne; Carpenter, John F; van de Weert, Marco

2004-01-01

The aim of this study was to characterize the effects of sucrose on the stability of recombinant factor VIIa (rFVIIa), with special emphasis on aggregation and methionine oxidation, as well as to investigate the impact of various environmental conditions on the rFVIIa conformation. The stability...... of rFVIIa was studied at pH 5. Aggregation was monitored using size exclusion high-performance liquid chromatography (SE-HPLC), whereas formation of methionine oxidation products was measured by reversed-phase high-performance liquid chromatography (RP-HPLC). Fourier transform infrared (FTIR...... the protein's surface, which shifts the protein molecular population away from expanded aggregation competent species and toward the compact native state, is thought to account for these observations. rFVIIa is sensitive to methionine oxidation; two mono-oxidized and one di-oxidized product were formed upon...

Interaction effects in magnetic oxide nanoparticle systems

Indian Academy of Sciences (India)

The interaction effects in magnetic nanoparticle system were studied through a Monte Carlo simulation. The results of simulations were compared with two different magnetic systems, namely, iron oxide polymer nanocomposites prepared by polymerization over core and nanocrystalline cobalt ferrite thin films prepared by ...

Effects of rare earth oxide addition on NdFeB magnets

International Nuclear Information System (INIS)

Ohashi, K.; Yokoyama, T.; Tawara, Y.

1988-01-01

The effects of addition of rare-earth oxides on the magnetic properties of Nd-Fe-B sintered magnets are studied. The addition of Dy 2 O 3 and Tb 4 O 7 leads to an increase in intrinsic coercivity. For addition of Dy 2 O 3 , the optimum conditions for powder mixing and the optimum Dy 2 O 3 particle size were determined. A mixing time of more than 10 minutes, and a Dy 2 O 3 particle size of less than 3 μm, are required to obtain a high intrinsic coercivity. EPMA measurements of NdFeBAl magnets with Dy 2 O 3 added reveal an inhomogeneous distribution of Dy in the Nd 2 Fe 14 B matrix: the material is Dy-rich near grain boundaries, but Dy-poor within the matrix. The appearance of such an inhomogeneous distribution of Dy is attributed to the reduction of Dy 2 O 3 in the Nd-rich phases, followed by diffusion of the resulting Dy atoms into the matrix

Comparison of the Effects of Pre-training Administration of Zinc Oxide and ‎Zinc Oxide Nanoparticles on Long-term Memory of Adult Male Mice

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N Issapare

2016-01-01

Full Text Available BACKGROUND AND OBJECTIVE: Zinc oxide nanoparticles are one of the most widely used nanoparticles in fields of industry, medicine, pharmaceutical sciences, cosmetics, and nutrition. Multiple studies have demonstrated the negative effects of zinc oxide nanoparticles on the nervous system, while others have revealed their enhancing effects on the activity of nerve cells, involved in memory processes. The aim of this study was to compare the effects of zinc oxide nanoparticles and zinc oxide on long-term memory of mice. METHODS: In this experimental study, 49 NMRI adult male mice, with the mean weight of 25±5 g, were randomly divided into seven groups, each consisting of seven mice: control group, three treatment groups receiving zinc oxide nanoparticles (1, 2.5, and 5 mg/kg of  zinc oxide nanoparticles, respectively, and three treatment groups receiving zinc oxide (1, 2.5, and 5 mg/kg of zinc oxide, respectively. Intraperitoneal injections were performed before training (electric shock. Passive avoidance memory of mice was evaluated, using the Step-Down device. The latency time to descend the platform was regarded as an indicator of memory on days 1, 3, and 7 following training. FINDINGS: Pre-training administration of zinc oxide nanoparticles and zinc oxide at a dose of 2.5 mg/kg yielded no effects on the motor activity of mice. However, a significant decline was reported in the latency time to descend the platform on days 1, 3, and 7 following training (58±17, 45±13, and 39±14 in the zinc oxide group and 93±18, 62±12, and 14±3 in the nano zinc oxide group, respectively (p<0.01 however, the dosage of 5 mg/kg had less significant short-term effects (130±38, 49±14, and 68±10 in the zinc oxide group and 132±46, 41±13, and 58±24 in the nano zinc oxide group, respectively. Also, the dosage of 1 mg/kg was almost ineffective. CONCLUSION: The results showed that weakened long-term memory, caused by zinc oxide administration, is not

Modulator effect of watercress against cyclophosphamide-induced oxidative stress in mice

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Natalia A. Casanova

2017-06-01

Full Text Available Watercress (Nasturtium officinale, Cruciferae; W. Aiton is a vegetable widely consumed in our country, with nutritional and potentially chemopreventive properties. Previous reports from our laboratory demonstrated the protective effect of watercress juice against DNA damage induced by cyclophosphamide in vivo. In this study, we evaluated the in vivo effect of cress plant on the oxidative stress in mice. Animals were treated by gavage with different doses of watercress juice (0.5 and 1g/kg body weight for 15 consecutive days before intraperitoneal injection of cyclophosphamide (100 mg/kg body weight. After 24 h, mice were killed by cervical dislocation. The effect of watercress was investigated by assessing the following oxidative stress biomarkers: catalase activity, superoxide dismutase activity, lipid peroxidation, and glutathione balance. Intake of watercress prior to cyclophosphamide administration enhanced superoxide dismutase activity in erythrocytes with no effect on catalase activity. In bone marrow and liver tissues, watercress juice counteracted the effect of cyclophosphamide. Glutathione balance rose by watercress supplementation and lipid oxidation diminished in all matrixes when compared to the respective control groups. Our results support the role of watercress as a diet component with promising properties to be used as health promoter or protective agent against oxidative damage

Oxidative Stress in Myopia

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Bosch-Morell Francisco

2015-01-01

Full Text Available Myopia affected approximately 1.6 billion people worldwide in 2000, and it is expected to increase to 2.5 billion by 2020. Although optical problems can be corrected by optics or surgical procedures, normal myopia and high myopia are still an unsolved medical problem. They frequently predispose people who have them to suffer from other eye pathologies: retinal detachment, glaucoma, macular hemorrhage, cataracts, and so on being one of the main causes of visual deterioration and blindness. Genetic and environmental factors have been associated with myopia. Nevertheless, lack of knowledge in the underlying physiopathological molecular mechanisms has not permitted an adequate diagnosis, prevention, or treatment to be found. Nowadays several pieces of evidence indicate that oxidative stress may help explain the altered regulatory pathways in myopia and the appearance of associated eye diseases. On the one hand, oxidative damage associated with hypoxia myopic can alter the neuromodulation that nitric oxide and dopamine have in eye growth. On the other hand, radical superoxide or peroxynitrite production damage retina, vitreous, lens, and so on contributing to the appearance of retinopathies, retinal detachment, cataracts and so on. The objective of this review is to suggest that oxidative stress is one of the key pieces that can help solve this complex eye problem.

Effect of vitamin A and vitamin C supplementation on oxidative stress in HIV and HIV-TB co-infection at Lagos University Teaching Hospital (LUTH) Nigeria.

Science.gov (United States)

Makinde, Oluwamayowa; Rotimi, Kunle; Ikumawoyi, Victor; Adeyemo, Titilope; Olayemi, Sunday

2017-06-01

HIV and TB infections are both associated with elevated oxidative stress parameters. Anti-oxidant supplementation may offer beneficial effects in positively modulating oxidative stress parameters in HIV and HIV-TB infected patients. We investigated the effects of vitamin A and C supplementation on oxidative stress in HIV infected and HIV-TB co-infected subjects. 40 HIV/TB co-infected and 50 HIV mono-infected patients were divided into 2 equal groups. Participants provided demographic information and blood was collected to determine oxidative stress parameters before and after vitamin A (5000 IU) and C (2600 mg) supplementation for 1 month. There was a significantly (p < 0.05) higher level of Malondialdehyde (MDA) at baseline for HIV infected subjects compared with HIV-TB co-infected subjects. There was a significantly (p < 0.05) lower level of MDA and higher level of Catalase (CAT) in subjects administered supplementation compared to subjects without supplementation for the HIV infected group. There was a significantly lower level of Reduced Glutathione (GSH), Superoxide Dismutase (SOD) and higher level of MDA after one month of supplementation compared with baseline levels for HIV/TB co infected subjects. A similar result was also obtained for the HIV mono-infected groups which had a significantly lower level of SOD, MDA and CAT compared to the baseline. There was a significantly lower level of GSH and SOD, and higher level of MDA after supplementation compared with the baseline for HIV/TB co-infected subjects. Comparing the indices at baseline and post no-supplementation in HIV/TB co-infection showed no significant differences in the oxidative stress parameters. HIV/TB co-infection and HIV mono-infection seems to diminish the capacity of the anti-oxidant system to control oxidative stress, however exogenous anti-oxidant supplementation appears not to have beneficial roles in positively modulating the associated oxidative stress.

Effect of Magnesium Oxide Nanoparticles on Water Glass Structure

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Bobrowski A.

2012-09-01

Full Text Available An attempt has been made to determine the effect of an addition of colloidal suspensions of the nanoparticles of magnesium oxide on the structure of water glass, which is a binder for moulding and core sands. Nanoparticles of magnesium oxide MgO in propanol and ethanol were introduced in the same mass content (5wt.% and structural changes were determined by measurement of the FT-IR absorption spectra.

Effect of seasonal affective disorder and pathological tanning motives on efficacy of an appearance-focused intervention to prevent skin cancer.

Science.gov (United States)

Hillhouse, Joel; Turrisi, Rob; Stapleton, Jerod; Robinson, June

2010-05-01

To evaluate the robustness of an appearance-focused intervention to prevent skin cancer in individuals reporting seasonal affective disorder (SAD) symptoms and pathological tanning motives. Randomized, controlled clinical trial. College campus. Four hundred thirty adult female indoor tanners (200 in the intervention group and 230 control participants). A booklet discussing the history of tanning, current tanning norms, UV radiation's effects on skin, recommendations for indoor tanning use focusing on abstinence and harm reduction recommendations, and information on healthier, appearance-enhancing alternatives to tanning. Self-reported attitudes, intentions, and tanning behaviors; pathological tanning motives assessed by a questionnaire developed for this study; and SAD symptoms assessed by the Seasonal Pattern Assessment Questionnaire. Two of the 4 pathological tanning scales, opiatelike reactions to tanning and dissatisfaction with natural skin tone, were significant moderators demonstrating stronger treatment effects for individuals scoring higher on these scales. Treatment effects were equivalently positive (ie, no significant moderator effects) for all levels of SAD symptoms and all levels of the other 2 pathological tanning motive scales (ie, perceiving tanning as a problem and tolerance to the effects of tanning). The appearance-focused skin cancer prevention intervention is robust enough to reduce indoor tanning among tanners who exhibit SAD symptoms or pathological tanning motives. Tailored interventions may address individuals' motivations for tanning and their relation to maladaptive behavior, such as dissatisfaction with appearance or the need for relaxation because of anxiety.

Acute effects of nandrolone decanoate on oxidative stress in isolated rat heart

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Jevđević Maja

2015-01-01

Full Text Available Abuse of anabolic-androgenic steroids (AAS produces side effects in different tissues, with oxidative stress linked to their pathophysiology, being involved in fibrosis, cellular proliferation, and tumorigenesis. The aim of this study was to examine the acute effects of nandrolone decanoate (ND on oxidative stress in isolated rat heart. The hearts of male Wistar albino were excised and perfused according to the Langendorff technique at gradually increasing coronary perfusion pressures (40-120 cmH2O. The hearts were perfused with ND at doses of 1, 10 and 100 μM. Oxidative stress markers, including the index of lipid peroxidation (thiobarbituric acid reactive substances (TBARS, nitric oxide (nitrites; NO2-, the superoxide anion radical (O2- and hydrogen peroxide (H2O2 were measured in the coronary venous effluent. Our results showed that acute effects of ND do not promote the production of reactive oxygen species (ROS. Our finding pointed out that the highest concentration of ND may even possess some anti-oxidative potential, which should be examined further.

Effect of drying method on properties of vanadium-molybdenum oxide catalysts

International Nuclear Information System (INIS)

Gorshkova, T.P.; Savchenko, L.A.; Tarasova, D.V.; Tret'yakov, Yu.D.; Olen'kova, I.P.; Nikoro, T.A.; Maksimov, N.G.

1981-01-01

Effect of drying method of molybdenum and vanadium salt solutions on physicochemical and catalytical properties of vanadium-molybdenum catalysts is studied. It is shown that the drying method of solutions determines the completeness of vanadium binding into oxide vanadium-molybdenum compounds and thus effects the activity and selectivity of catalysts in acrolein oxidation into acrylic acid. Besides the drying method determines the porous structure of catalysts [ru

The effect of oxidative stress on the progression of Hashimoto's thyroiditis.

Science.gov (United States)

Ates, Ihsan; Arikan, Mehmet Fettah; Altay, Mustafa; Yilmaz, Fatma Meric; Yilmaz, Nisbet; Berker, Dilek; Guler, Serdar

2017-11-29

We aimed to investigate the effects of oxidative stress in the pathogenesis and progression of Hashimoto's thyroiditis (HT). Forty euthyroid and 40 subclinical hypothyroid patients older than 18 years and not yet had received treatment were enrolled in the study. In the 9 months follow-up, 14 of the HT patients developed overt hypothyroidism. The mean total oxidant status (TOS) and oxidative stress index (OSI) were higher in patients who developed overt hypothyroidism than those who did not (p  .05). Multivariable Cox regression model showed thyroid stimulating hormone level (HR = 1.348, p OSI ratio (HR = 2.349, p OSI level, being over 2.96 with 92.9% sensitivity and 62.5% specificity, predicts the risk of hypothyroidism. Oxidative stress may be an effective risk factor in the development of overt hypothyroidism in HT.

HPLC Separation of Vitamin E and Its Oxidation Products and Effects of Oxidized Tocotrienols on the Viability of MCF-7 Breast Cancer Cells in Vitro.

Science.gov (United States)

Drotleff, Astrid M; Büsing, Anne; Willenberg, Ina; Empl, Michael T; Steinberg, Pablo; Ternes, Waldemar

2015-10-14

Tocotrienols, a vitamin E subgroup, exert potent anticancer effects, but easily degrade due to oxidation. Eight vitamin E reference compounds, α-, β-, γ-, or δ-tocopherols or -tocotrienols, were thermally oxidized in n-hexane. The corresponding predominantly dimeric oxidation products were separated from the parent compounds by diol-modified normal-phase HPLC-UV and characterized by mass spectroscopy. The composition of test compounds, that is, α-tocotrienol, γ-tocotrienol, or palm tocotrienol-rich fraction (TRF), before and after thermal oxidation was determined by HPLC-DAD, and MCF-7 cells were treated with both nonoxidized and oxidized test compounds for 72 h. Whereas all nonoxidized test compounds (0-100 μM) led to dose-dependent decreases in cell viability, equimolar oxidized α-tocotrienol had a weaker effect, and oxidized TRF had no such effect. However, the IC50 value of oxidized γ-tocotrienol was lower (85 μM) than that of nonoxidized γ-tocotrienol (134 μM), thereby suggesting that γ-tocotrienol oxidation products are able to reduce tumor cell viability in vitro.

Adverse Cardiovascular Effects of Nitrous Oxide: It is not all about Hyperhomocysteinaemia

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Ata Mahmoodpoor

2015-04-01

Full Text Available Once admired for its supposed safety, nitrous oxide is presently blamed to increase adverse cardiovascular effects through augmenting plasma homocysteine concentrations (1, 2. Hemodynamic alterations following the administration of nitrous oxide are extremely complicated and sometimes contradictory. Enhanced venous return, arterial pressure, pulmonary and systemic vascular resistance, cardiac output, pupillary dilation and diaphoresis occur under nitrous oxide administration consistent with sympathomimetic properties of nitrous oxide (3. Conversely, reductions in arterial pressure are also probable, especially in patients with coronary artery disease. Nitrous oxide can also depress myocardial contractility due to decreased availability of Ca2+ for contractile activation; yet, myocardial relaxation kinetics remains intact (4. In the presence of a volatile anesthetic, nitrous oxide decreases MVO2 (Myocardial oxygen consumption and myocardial O2 extraction which may exacerbate myocardial ischemia during concomitant reductions in arterial pressure in patients with coronary artery disease. Consequently, it could be conjectured that probable adverse cardiovascular effects following nitrous oxide administration are variable and consequent of a multi-variable phenomenon rather than a single variable such as increased levels of homocysteine. Studied purely focusing on the effects of nitrous oxide are difficult to conduct due to the numerous confounding factors. In a study by Myles et al., hyperhomocysteinemia has been introduced as the source of the adverse cardiovascular effects of nitrous oxide. However, in this study, increased inspired oxygen concentrations were used to overcome arterial desaturation (1. Given the fact that a constant volume and flow rates are used throughout the anesthesia in a particular patient, increasing the concentrations of oxygen would be associated with decreased delivered nitrous oxide and volatile anesthetic concentrations

Effects of viewing a pro-ana website: an experimental study on body satisfaction, affect, and appearance self-efficacy.

Science.gov (United States)

Delforterie, Monique J; Larsen, Junilla K; Bardone-Cone, Anna M; Scholte, Ron H J

2014-01-01

Pro-anorexia websites portray an extreme form of thin-ideal. This between-subjects experiment examined the effects of viewing such a website on body satisfaction, affect, and appearance self-efficacy compared to viewing control websites (fashion, home decoration, automutilation). The sample consisted of 124 normal weight, young adult, Dutch women (mean age 21.2, mean body mass index 21.4). Participants did not differ on affect and appearance self-efficacy. One body satisfaction measure showed that pro-anorexia viewers were more satisfied with their bodies than home decoration viewers. Our findings suggest that viewing a pro-anorexia website might not have detrimental effects on body satisfaction and affect among normal weight young women.

Effect of temperature on the electro-oxidation of ethanol on platinum

Directory of Open Access Journals (Sweden)

Ana Paula M. Camargo

2010-01-01

Full Text Available We present in this work an experimental investigation of the effect of temperature (from 25 to 180 ºC in the electro-oxidation of ethanol on platinum in two different phosphoric acid concentrations. We observed that the onset potential for ethanol electro-oxidation shifts to lower values and the reaction rates increase as temperature is increased for both electrolytes. The results were rationalized in terms of the effect of temperature on the adsorption of reaction intermediates, poisons, and anions. The formation of oxygenated species at high potentials, mainly in the more diluted electrolyte, also contributes to increase the electro-oxidation reaction rate.

On the effect of pre-oxidation on the nitriding kinetics

DEFF Research Database (Denmark)

Friehling, Peter Bernhard; Somers, Marcel A. J.

2000-01-01

The oxidation of ferritic surfaces prior to gaseous nitriding has been reported to lead to improved uniformity of the compound layer thickness and enhanced nitriding kinetics. The present work considers the nucleation and growth of a model compound layer on pure iron and, using previous...... experimental and theoretical work reported in the literature, puts forward two hypotheses to explain the effects of pre-oxidation on compound layer formation. It is proposed that the nucleation of iron nitrides is enhanced by the presence of an iron-oxide layer and that the growth of an iron-nitride layer...... proceeds faster after pre-oxidation, due to a higher nitrogen content in the part of the compound layer closest to the surface....

Pressure effects on high temperature steam oxidation of Zircaloy-4

International Nuclear Information System (INIS)

Park, Kwangheon; Kim, Kwangpyo; Ryu, Taegeun

2000-01-01

The pressure effects on Zircaloy-4 (Zry-4) cladding in high temperature steam have been analyzed. A double layer autoclave was made for the high pressure, high temperature oxidation tests. The experimental test temperature range was 700 - 900 deg C, and pressures were 0.1 - 15 MPa. Steam partial pressure turns out to be an important one rather than total pressure. Steam pressure enhances the oxidation rate of Zry-4 exponentially. The enhancement depends on the temperature, and the maximum exists between 750 - 800 deg C. Pre-existing oxide layer decreases the enhancement about 40 - 60%. The acceleration of oxidation rate by high pressure team seems to be originated from the formation of cracks by abrupt transformation of tetragonal phase in oxide, where the un-stability of tetragonal phase comes from the reduction of surface energy by steam. (author)

Effect of Antifoam Agent on Oxidative Leaching of Hanford Tank Sludge Simulants

International Nuclear Information System (INIS)

Rapko, Brian M.; Jones, Susan A.; Lumetta, Gregg J.; Peterson, Reid A.

2010-01-01

Oxidative leaching of simulant tank waste containing an antifoam agent (AFA) to reduce the chromium content of the sludge was tested using permanganate as the oxidant in 0.25 M NaOH solutions. AFA is added to the waste treatment process to prevent foaming. The AFA, Dow Corning Q2-3183A, is a surface-active polymer that consists of polypropylene glycol, polydimethylsiloxane, octylphenoxy polyethoxy ethanol, treated silica, and polyether polyol. Some of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) waste slurries contain high concentrations of undissolved solids that would exhibit undesirable behavior without AFA addition. These tests were conducted to determine the effect of the AFA on oxidative leaching of Cr(III) in waste by permanganate. It has not previously been determined what effect AFA has on the permanganate reaction. This study was conducted to determine the effect AFA has on the oxidation of the chromium, plus plutonium and other criticality-related elements, specifically Fe, Ni and Mn. During the oxidative leaching process, Mn is added as liquid permanganate solution and is converted to an insoluble solid that precipitates as MnO2 and becomes part of the solid waste. Caustic leaching was performed followed by an oxidative leach at either 25 C or 45 C. Samples of the leachate and solids were collected at each step of the process. Initially, Battelle-Pacific Northwest Division (PNWD) was contracted by Bechtel National, Inc. to perform these further scoping studies on oxidative alkaline leaching. The data obtained from the testing will be used by the WTP operations to develop procedures for permanganate dosing of Hanford tank sludge solids during oxidative leaching. Work was initially conducted under contract number 24590-101-TSA-W000-00004. In February 2007, the contract mechanism was switched to Pacific Northwest National Laboratory (PNNL) operating Contract DE-AC05-76RL01830. In summary, this report describes work focused on determining

Effect of Antifoam Agent on Oxidative Leaching of Hanford Tank Sludge Simulants

Energy Technology Data Exchange (ETDEWEB)

Rapko, Brian M.; Jones, Susan A.; Lumetta, Gregg J.; Peterson, Reid A.

2010-02-26

Oxidative leaching of simulant tank waste containing an antifoam agent (AFA) to reduce the chromium content of the sludge was tested using permanganate as the oxidant in 0.25 M NaOH solutions. AFA is added to the waste treatment process to prevent foaming. The AFA, Dow Corning Q2-3183A, is a surface-active polymer that consists of polypropylene glycol, polydimethylsiloxane, octylphenoxy polyethoxy ethanol, treated silica, and polyether polyol. Some of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) waste slurries contain high concentrations of undissolved solids that would exhibit undesirable behavior without AFA addition. These tests were conducted to determine the effect of the AFA on oxidative leaching of Cr(III) in waste by permanganate. It has not previously been determined what effect AFA has on the permanganate reaction. This study was conducted to determine the effect AFA has on the oxidation of the chromium, plus plutonium and other criticality-related elements, specifically Fe, Ni and Mn. During the oxidative leaching process, Mn is added as liquid permanganate solution and is converted to an insoluble solid that precipitates as MnO2 and becomes part of the solid waste. Caustic leaching was performed followed by an oxidative leach at either 25°C or 45°C. Samples of the leachate and solids were collected at each step of the process. Initially, Battelle-Pacific Northwest Division (PNWD) was contracted by Bechtel National, Inc. to perform these further scoping studies on oxidative alkaline leaching. The data obtained from the testing will be used by the WTP operations to develop procedures for permanganate dosing of Hanford tank sludge solids during oxidative leaching. Work was initially conducted under contract number 24590-101-TSA-W000-00004. In February 2007, the contract mechanism was switched to Pacific Northwest National Laboratory (PNNL) operating Contract DE-AC05-76RL01830. In summary, this report describes work focused on

Effect of total pressure on graphite oxidation

International Nuclear Information System (INIS)

Burnette, R.D.; Hoot, C.G.

1983-04-01

Graphite corrosion in the high-temperature gas-cooled reactor (HTGR) is calculated using two key assumptions: (1) the kinetic, catalysis, and transport characteristics of graphite determined by bench-scale tests apply to large components at reactor conditions and (2) the effects of high pressure and turbulent flow are predictable. To better understand the differences between laboratory tests and reactor conditions, a high-pressure test loop (HPTL) has been constructed and used to perform tests at reactor temperature, pressure, and flow conditions. The HPTL is intended to determine the functional dependence of oxidation rate and characteristics on total pressure and gas velocity and to compare the oxidation results with calculations using models and codes developed for the reactor

Temperature effect on surface oxidation of titanium

International Nuclear Information System (INIS)

Vaquilla, I.; Barco, J.L. del; Ferron, J.

1990-01-01

The effect of temperature on the first stages of the superficial oxidation of polycrystalline titanium was studied using both Auger electron spectroscopy (AES) and emission shreshold (AEAPS). The number of compounds present on the surface was determined by application of the factor analysis technique. Reaction evolution was followed through the relative variation of Auger LMM and LMV transitions which are characteristic of titanium. Also the evolution of the chemical shift was determined by AEAPS. The amount of oxygen on the surface was quantified using transition KLL of oxygen. It was found that superficial oxidation depends on temperature. As much as three different compounds were determined according to substrate temperature and our exposure ranges. (Author). 7 refs., 5 figs

The Effect of atmospheric humidity level to the determination of Islamic Fajr/morning prayer time and twilight appearance

Science.gov (United States)

Rohmah, Nihayatur

2016-11-01

Islamic prayer times are based on the astronomical position of the Sun in the sky. One of them is the Fajr prayer. It is marked by some indicators in the morning twilight which is white light spread in the Eastern horizon. However, determining the true time of twilight can be difficult. One of the reasons is the effect of atmospheric humidity to the appearance of morning twilight. The higher the humidity, the redder twilight sky appearance. This paper discusses this effect. It is shown that despite of the same Sun's position, sky color can vary considerably. Observations of various solar dip angle have been made to study this effect. Visibility for different angle can change accordingly. We obtained that the average solar dip for Fajr prayer by morning twilight images was -18°39'29.4".

Optimal linguistic expression in negotiations depends on visual appearance.

Science.gov (United States)

Sakamoto, Maki; Kwon, Jinhwan; Tamada, Hikaru; Hirahara, Yumi

2018-01-01

We investigate the influence of the visual appearance of a negotiator on persuasiveness within the context of negotiations. Psychological experiments were conducted to quantitatively analyze the relationship between visual appearance and the use of language. Male and female participants were shown three female and male photographs, respectively. They were asked to report how they felt about each photograph using a seven-point semantic differential (SD) scale for six affective factors (positive impression, extraversion, intelligence, conscientiousness, emotional stability, and agreeableness). Participants then answered how they felt about each negotiation scenario (they were presented with pictures and a situation combined with negotiation sentences) using a seven-point SD scale for seven affective factors (positive impression, extraversion, intelligence, conscientiousness, emotional stability, agreeableness, and degree of persuasion). Two experiments were conducted using different participant groups depending on the negotiation situations. Photographs with good or bad appearances were found to show high or low degrees of persuasion, respectively. A multiple regression equation was obtained, indicating the importance of the three language factors (euphemistic, honorific, and sympathy expressions) to impressions made during negotiation. The result shows that there are optimal negotiation sentences based on various negotiation factors, such as visual appearance and use of language. For example, persons with good appearance might worsen their impression during negotiations by using certain language, although their initial impression was positive, and persons with bad appearance could effectively improve their impressions in negotiations through their use of language, although the final impressions of their negotiation counterpart might still be more negative than those for persons with good appearance. In contrast, the impressions made by persons of normal appearance

Effects of sulfur dioxide and nitric oxide on mercury oxidation and reduction under homogeneous conditions

Energy Technology Data Exchange (ETDEWEB)

Yongxin Zhao; Michael D. Mann; Edwin S. Olson; John H. Pavlish; Grant E. Dunham [University of North Dakota, Grand Forks, ND (United States). Department of Chemical Engineering

2006-05-15

This paper is particularly related to elemental mercury (Hg{sup 0}) oxidation and divalent mercury (Hg{sup 2+} reduction under simulated flue gas conditions in the presence of nitric oxide (NO) and sulfur dioxide (SO{sub 2}). As a powerful oxidant and chlorinating reagent, Cl{sub 2} has the potential for Hg oxidation. However, the detailed mechanism for the interactions, especially among chlorine (Cl)-containing species, SO{sub 2}, NO, as well as H{sub 2}O, remains ambiguous. Research described in this paper therefore focused on the impacts of SO{sub 2} and NO on Hg{sup 0} oxidation and Hg{sup 2+} reduction with the intent of unraveling unrecognized interactions among Cl species, SO{sub 2}, and NO most importantly in the presence of H{sub 2}O. The experimental results demonstrated that SO{sub 2} and NO had pronounced inhibitory effects on Hg{sup 0} oxidation at high temperatures when H{sub 2}O was also present in the gas blend. Such a demonstration was further confirmed by the reduction of Hg{sup 2+} back into its elemental form. Data revealed that SO{sub 2} and NO were capable of promoting homogeneous reduction of Hg{sup 2+} to Hg{sup 0} with H{sub 2}O being present. However, the above inhibition or promotion disappeared under homogeneous conditions when H{sub 2}O was removed from the gas blend. 23 refs., 8 figs.

A novel hydrogen oxidizer amidst the sulfur-oxidizing Thiomicrospira lineage

Science.gov (United States)

Hansen, Moritz; Perner, Mirjam

2015-01-01

Thiomicrospira species are ubiquitously found in various marine environments and appear particularly common in hydrothermal vent systems. Members of this lineage are commonly classified as sulfur-oxidizing chemolithoautotrophs. Although sequencing of Thiomicrospira crunogena's genome has revealed genes that encode enzymes for hydrogen uptake activity and for hydrogenase maturation and assembly, hydrogen uptake ability has so far not been reported for any Thiomicrospira species. We isolated a Thiomicrospira species (SP-41) from a deep sea hydrothermal vent and demonstrated that it can oxidize hydrogen. We show in vivo hydrogen consumption, hydrogen uptake activity in partially purified protein extracts and transcript abundance of hydrogenases during different growth stages. The ability of this strain to oxidize hydrogen opens up new perspectives with respect to the physiology of Thiomicrospira species that have been detected in hydrothermal vents and that have so far been exclusively associated with sulfur oxidation. PMID:25226028

Effect of selective removal of organic matter and iron oxides on the ...

African Journals Online (AJOL)

The effect of selective removal of organic matter and amorphous and crystalline iron oxides on N2-BET specific surface areas of some soil clays was evaluated. Clay fractions from 10 kaolinitic tropical soils were successively treated to remove organic matter by oxidation with Na hypochlorite, amorphous Fe oxide with acid ...

Electrochemical One-Electron Oxidation of Low-Generation Polyamidoamine-Type Dendrimers with a 1,4-Phenylenediamine Core

DEFF Research Database (Denmark)

Hammerich, Ole; Hansen, Thomas; Thorvildsen, Asbjørn

2009-01-01

voltammetry (DPV) in methanol, acetonitrile, dichloromethane, and dimethyl sulfoxide. The dendrimers are more difficult to oxidize than N,N,N',N'-tetramethyl-p-phenylenediamine (TMePD). The oxidation potentials decrease with increasing dendrimer generation up to G0.5, after which the potential is essentially......A series of polyamidoamine (PAMAM)-type dendrimers with a 1,4-phenylenediamine (PD) core is prepared from PD by procedures including Michael addition of methyl acrylate followed by aminolysis with 1,2-ethanediamine. Their one-electron oxidation potentials are determined by differential pulse......,N,N',N'-tetra-n-alkyl-p-phenylenediamines, including a planar arrangement of the atoms linked to the two PD nitrogen atoms. Thus, the effect of chain size on the oxidation potential appears to be caused primarily by a simple electronic effect. The calculations indicate considerable reorientation of the dendrimer side chains on oxidation, presumably...

Effects of Muscle-Specific Oxidative Stress on Cytochrome c Release and Oxidation-Reduction Potential Properties.

Science.gov (United States)

Ke, Yiling; Mitacek, Rachel M; Abraham, Anupam; Mafi, Gretchen G; VanOverbeke, Deborah L; DeSilva, Udaya; Ramanathan, Ranjith

2017-09-06

Mitochondria play a significant role in beef color. However, the role of oxidative stress in cytochrome c release and mitochondrial degradation is not clear. The objective was to determine the effects of display time on cytochrome c content and oxidation-reduction potential (ORP) of beef longissimus lumborum (LL) and psoas major (PM) muscles. PM discolored by day 3 compared with LL. On day 0, mitochondrial content and mitochondrial oxygen consumption were greater in PM than LL. However, mitochondrial content and oxygen consumption were lower (P stress can affect cytochrome c release and ORP changes.

Effect of oxygen partial pressure on oxidation of Mo-metal

Science.gov (United States)

Sharma, Rabindar Kumar; Kumar, Prabhat; Singh, Megha; Gopal, Pawar; Reddy, G. B.

2018-05-01

This report explains the effect of oxygen partial pressure (PO2 ) on oxidation of Mo-metal in oxygen plasma. XRD results indulge that oxide layers formed on Mo-surfaces at different oxygen partial pressures have two different oxide phases (i.e. orthorhombic MoO3 and monoclinic Mo8O23). Intense XRD peaks at high pressure (i.e. 2.0×10-1 Torr) points out the formation of thick oxide layer on Mo-surface due to presence of large oxygen species in chamber and less oxide volatilization. Whereas, at low PO2 (6.5×10-2 and 7.5×10-2 Torr.) the reduced peak strength is owing to high oxide volatilization rate. SEM micrographs and thickness measurements also support XRD results and confirm that the optimum -2value of PO2 to deposited thicker and uniform oxide film on glass substrate is 7.5×10-2 Torr through plasma assistedoxidation process. Further to study the compositional properties, EDX of the sample M2 (the best sample) is carried out, which confirms that the stoichiometric ratio is less than 3 (i.e. 2.88). Less stoichiometric ratio again confirms the presence of sub oxides in oxide layers on Mo metal as evidenced by XRD results. All the observed results are well in consonance with each other.

On hydrazine oxidation in nitric acid media

International Nuclear Information System (INIS)

Zil'berman, B.Ya.; Lelyuk, G.A.; Mashkin, A.N.; Yasnovitskaya, A.L.

1988-01-01

Yield of products of radiolytic ( 60 Co gamma radiation) and chemical hydrazine (HZ) oxidation in nitric acid media is studied. Under radiolyte HZ oxidation by nitric acid hydrazoic acid, ammonia and nitrogen appear to be the reaction products. HN 3 yield maximum under HZN oxidation makes up ∼ 0.35 mol per a mol of oxiduzed HZN. Under chemical oxidation HZN is oxidized by HNO 3 according to reaction catalysed by technetium HN 3 yield makes up ∼ 0.35 mol per a mol of oxidized HZN. Radiation-chemical oxidation of HN 3 proceeds up to its complete decomposition, decomposition rate is comparable with HZ oxidation rate. Under the chemical oxidation HN 3 is more stable, it is slowly decomposed after complete HZ decomposition

Effects of concurrent training on oxidative capacity in rat gastrocnemius muscle

NARCIS (Netherlands)

Furrer, R.; Bravenboer, N.; Kos, D.; Lips, P.; de Haan, A.; Jaspers, R.T.

2013-01-01

PURPOSE: Training for improvement of oxidative capacity of muscle fibers may be attenuated when concurrently training for peak power. However, because of fiber type-specific recruitment, such attenuation may only account for high-oxidative muscle fibers. Here, we investigate the effects of

The Effect of Hypochlorite Oxidation and Acetylation on Some of the ...

African Journals Online (AJOL)

The study evaluated the effect of hypochlorite oxidation and acetylation on some physicochemical properties of Icacina trichantha starch. The native and modified (oxidized and acetylated) starches were studied with respect to Infrared spectroscopy(IR), microscopy, gelatinization, swelling power, solubility index, amylose ...

Oxidants and anti-oxidants in turbot seminal plasma and their effects on sperm quality

Science.gov (United States)

Han, Mingming; Ding, Fuhong; Meng, Zhen; Lei, Jilin

2015-08-01

In this research, the concentration and activity of oxidants and anti-oxidants in turbot semen, and their effects on sperm quality were studied. The results showed that superoxide dismutase (SOD), catalase, glutathione reductase (GR), uric acid, vitamin E (VE) and vitamin C (VC) were more abundant in seminal plasma than in spermatozoa. The variation for each of them was specific. In seminal plasma, the activity of SOD and GR increased from November 15, November 30 to December 15, and then decreased on December 30. The concentrations of both VC and uric acid decreased during the first 3 sampling times and increased on December 30. The oxidants in seminal plasma accumulated to the highest on December 30. Lactic acid (LA) and ATP levels decreased to the lowest on December 30. The correlation analysis showed that GR had the significant positive relevance to sperm motility and VSL/VCL, while ·OH had negative relevance to them.

TOLUENE EFFECTS ON OXIDATIVE STRESS IN BRAIN REGIONS OF YOUNG-ADULT, MIDDLE-AGE AND SENESCENT BROWN NORWAY RATS

Science.gov (United States)

Aging-related susceptibility to environmental chemicals is poorly understood. Oxidative stress (OS) appears to play an important role in susceptibility and disease in old age. The objectives of this study, therefore, were to test whether OS is a potential toxicity pathway for tol...

Effect of cocoa bran on low-density lipoprotein oxidation and fecal bulking.

Science.gov (United States)

Jenkins, D J; Kendall, C W; Vuksan, V; Vidgen, E; Wong, E; Augustin, L S; Fulgoni, V

Legumes have reported benefits in terms of reduced risk for coronary heart disease and of colonic health. A novel legume fiber, cocoa bran, also may have favorable health effects on serum lipid levels, low-density lipoprotein (LDL) cholesterol oxidation, and fecal bulk. Twenty-five healthy normolipidemic subjects (13 men and 12 women) (mean +/- SEM age, 37 +/- 2 years; mean +/- SEM body mass index [calculated as weight in kilograms divided by the square of height in meters], 24.6 +/- 0.7) ate cocoa-bran and chocolate-flavored low-fiber breakfast cereals for 2-week periods, with 2-week washout, in a double-blind crossover study. The cocoa-bran cereal provided 25.0 g/d of total dietary fiber (TDF). The low-fiber cereal (5.6 g/d TDF) was of similar appearance and energy value. Fasting blood samples were obtained at the start and end of each period, and 4-day fecal collections were made from days 11 through 14. High-density lipoprotein (HDL) cholesterol level was higher (7.6% +/- 2.9%; P =.02) and the LDL/HDL cholesterol ratio was lower (6.7% +/- 2.3%; P =.007) for cocoa-bran compared with low-fiber cereal at 2 weeks. No effect was seen on LDL cholesterol oxidation. Mean fecal output was significantly higher for cocoa-bran than for low-fiber cereal (56 +/- 14 g/d; Pchocolate-flavored cocoa-bran cereal increased fecal bulk similarly to wheat bran and was associated with a reduction in the LDL/HDL cholesterol ratio. In view of the low-fat, high-fiber nature of the material, these results suggest a possible role for this novel fiber source in the diets of normal, hyperlipidemic, and constipated subjects.

Nitric oxide-related species-induced protein oxidation: reversible, irreversible, and protective effects on enzyme function of papain.

Science.gov (United States)

Väänänen, Antti J; Kankuri, Esko; Rauhala, Pekka

2005-04-15

Protein oxidation, irreversible modification, and inactivation may play key roles in various neurodegenerative disorders. Therefore, we studied the effects of the potentially in vivo occurring nitric oxide-related species on two different markers of protein oxidation: protein carbonyl generation on bovine serum albumine (BSA) and loss of activity of a cysteine-dependent protease, papain, in vitro by using Angeli's salt, papanonoate, SIN-1, and S-nitrosoglutathione (GSNO) as donors of nitroxyl, nitric oxide, peroxynitrite, and nitrosonium ions, respectively. Angeli's salt, SIN-1, and papanonoate (0-1000 microM) all generated a concentration-dependent increase in carbonyl formation on BSA (107, 60, and 45%, respectively). GSNO did not affect carbonyl formation. Papain was inhibited by Angeli's salt, SIN-1, papanonoate, and GSNO with IC50 values of 0.62, 2.3, 54, and 80 microM, respectively. Angeli's salt (3.16 microM)-induced papain inactivation was only partially reversible, while the effects of GSNO (316 microM) and papanonoate (316 microM) were reversible upon addition of excess DTT. The Angeli's salt-mediated DTT-irreversible inhibition of papain was prevented by GSNO or papanonoate pretreatment, hypothetically through mixed disulfide formation or S-nitrosylation of the catalytically critical thiol group of papain. These results, for the first time, compare the generation of carbonyls in proteins by Angeli's salt, papanonoate, and SIN-1. Furthermore, these results suggest that S-nitrosothiols may have a novel function in protecting critical thiols from irreversible oxidative damage.

High temperature oxidation of thin FeCrAl strips

International Nuclear Information System (INIS)

Andrieu, E.; Germidis, A.; Molins, R.

1997-01-01

This study concerns the oxidation behaviour between 850 and 1100 C of FeCrAl thin strips. Oxidation kinetics have been continuously recorded on a thermobalance as well as discontinuously in an ''industrial'' furnace. Detailed observations of oxide layers have been performed in transmission electron microscopy on oxidized thin foil cross-sections. Oxide morphologies are correlated with kinetics: Slow kinetics and columnar α alumina grains above 950 C, fast kinetics and transition alumina platelets (γ-alumina) at 850 C and 900 C, followed by small α-alumina grains formation underneath. The weight gains in the industrial furnace displayed significant scatter and were generally greater than those measured in the thermobalance. The effect of extrinsic factors such as specimen size and shape, atmosphere, air flow conditions on the early formation of transition aluminas explains the observed differences. It appears then that in given cases parabolic constant identification from TGA recordings is difficult, or even impossible. This might contribute to explain the differences in the results presented in the literature. (orig.)

Protective effects of dietary glycine and glutamic acid toward the toxic effects of oxidized mustard oil in rabbits.

Science.gov (United States)

Zeb, Alam; Rahman, Saleem Ur

2017-01-25

The protective role of glycine and glutamic acid against the toxic effects of oxidized oil was studied for the first time. Mustard seed oil was thermally oxidized and characterized for quality characteristics and polyphenolic composition using reversed phase HPLC-DAD. Significant changes in the quality characteristics occurred with thermal oxidation. Fourteen polyphenolic compounds were identified and quantified in oils. Quercetin-3-glucoside, quercetin-3-feruloylsophoroside, catechin, quercetin-3-rutinoside, quercetin-3,7-diglucoside, sinapic acid and vanillic acid hexoside were the major compounds in the fresh and oxidized oil. Oxidized, un-oxidized mustard oils, glycine and glutamic acid were given to rabbits alone or in combination. The biochemical responses were studied in terms of haematological and biochemical parameters and histopathology. It has been observed that biochemical and haematological parameters were adversely affected by the oxidized oil, while supplementation of both amino acids was beneficial in normalizing these parameters. Both amino acids alone have no significant effects, however, oxidized oil affected the liver by enhancing fat accumulation, causing hepatitis, reactive Kupffer cells and necrosis. The co-administration of oxidized oils with glycine or glutamic acid revealed significant recovery of the liver structure and function. In conclusion, glycine or glutamic acid is beneficial and protective against food toxicity and can be considered as an ameliorative food supplement.

Effect of soy sauce on lipid oxidation of irradiated pork patties

International Nuclear Information System (INIS)

Kim, Hyun-Wook; Hwang, Ko-Eun; Choi, Yun-Sang; Choi, Ji-Hun; Lee, Mi-Ai; Song, Dong-Heon; Kim, Hack-Youn; Lee, Ju-Woon; Kim, Cheon-Jei

2013-01-01

This study was conducted to find out the antioxidant effect of the soy sauce on lipid oxidation of electron beam irradiated pork patties. The pork patties prepared with sodium chloride or soy sauce solution at identical salt concentrations were irradiated at 0 or 5 kGy, and peroxide value, conjugated diene, 2-thiobarbituric acid, and free fatty acid values were evaluated for 10 days (4 °C). The irradiated pork patties treated with soy sauce showed the lowest peroxide value and 2-thiobarbituric acid value at the end of storage compared to those prepared with sodium chloride. The irradiated pork patties formulated with soy sauce and 0.5% ascorbic acid had similar 2-thiobarbituric acid and free fatty acid values compared to those of the non-irradiated pork patties treated with sodium chloride. Our results suggested that the soy sauce can retard the lipid oxidation of irradiated pork patty, and a synergistic effect between soy sauce and ascorbic acid was observed. - Highlights: • Antioxidant effect of soy sauce on irradiated pork patties was studied. • The soy sauce can retard lipid oxidation of the irradiated pork patties. • A synergistic effect of ascorbic acid for preventing lipid oxidation was observed

Effect of Perovskite coating on oxide scale growth on Fe-22Cr

DEFF Research Database (Denmark)

Persson, Åsa; Mikkelsen, Lars; Hendriksen, Peter Vang

2006-01-01

A coating consisting of La0.85Sr0.15MnO3 (LSM) was deposited onto two Fe 22 wt % Cr alloys Crofer 22APU and Sandvik lC44Mo20. The evolution of the oxide layers developing underneath the coatings during oxidation was investigated. The effect of the LSM coating on oxidation rate and microstructure ...

Effects of Uric Acid on Exercise-induced Oxidative Stress

OpenAIRE

平井, 富弘

2001-01-01

We studied effects of uric acid on exercise― induced oxidative stress in humans based on a hypothesis that uric acid acts as an antioxidant to prevent from exercise―induced oxidative stress. Relation between uric acid level in plasma and increase of thiobarbituric acid reactive substance (TBARS)after the cycle ergometer exercise was examined. Thiobarbituricacid reactive substance in plasma increased after the ergometer exercise. High uric acid in plasma did not result in low increase of TBARS...

Effects of solid fission products forming dissolved oxide (Nd) and metallic precipitate (Ru) on the thermal conductivity of uranium base oxide fuel

International Nuclear Information System (INIS)

Kim, Dong-Joo; Yang, Jae-Ho; Kim, Jong-Hun; Rhee, Young-Woo; Kang, Ki-Won; Kim, Keon-Sik; Song, Kun-Woo

2007-01-01

The effects of solid fission products on the thermal conductivity of uranium base oxide nuclear fuel were experimentally investigated. Neodymium (Nd) and ruthenium (Ru) were added to represent the physical states of solid fission products such as 'dissolved oxide' and 'metallic precipitate', respectively. Thermal conductivity was determined on the basis of the thermal diffusivity, density and specific heat values. The effects of the additives on the thermal conductivity were quantified in the form of the thermal resistivity equation - the reciprocal of the phonon conduction equation - which was determined from the measured data. It is concluded that the thermal conductivity of the irradiated nuclear fuel is affected by both the 'dissolved oxide' and the 'metallic precipitate', however, the effects are in the opposite direction and the 'dissolved oxide' influences the thermal conductivity more significantly than that of the 'metallic precipitate'

The effect of obstructive sleep apnea on DNA damage and oxidative stress.

Science.gov (United States)

Kang, Il Gyu; Jung, Joo Hyun; Kim, Seon Tae

2013-06-01

Obstructive sleep apnea syndrome (OSAS) is associated with repeated hypoxia and re-oxygenation. This characteristic of OSAS may cause oxidative stress and DNA damage. However, the link of OSAS with oxidative stress and DNA damage is still controversial. In the current study, we investigated whether OSAS causes DNA damage using alkaline single-cell gel electrophoresis (comet assay) and measuring oxidative stress by monitoring serum malondialdehyde (MDA) levels. From March 2009 to August 2010, 51 patients who underwent polysomnography (PSG) during the night were enrolled in this study. We obtained serum from the patients at 6 AM. DNA damage and oxidative stress were evaluated using a comet assay and measuring serum MDA, respectively. We divided the patients into two groups according to the existence of comets appearing in the comet assay. Group 1 included 44 patients with negative assay results and group 2 consisted of seven patients with positive comet assay findings. We compared the age, gender proportion, PSG data (respiratory disturbance index [RDI], lowest O2 saturation level, and arousal index [AI]), time of disease onset, smoking habits, and serum MDA levels between the two groups. The average age and gender proportion of the two groups were not statistically different (P>0.05). The average of RDI for group 1 was 30.4±18.4 and 8.0±7.7 (P0.05). No relationship between positive comet assay results and OSAS severity was identified. Results of the current study showed that OSAS was not associated with DNA damage as measured by comet assays or oxidative stress according to serum MDA levels.

A time effect in the early stages of a surface oxidation of a Pt(111 plane in alkaline solution

Directory of Open Access Journals (Sweden)

J. D. LOVIC

2001-12-01

Full Text Available A time effect in the early stages of surface oxidation of a Pt(111 plane in 0.1 M NaOH solution was studied by examining the reduction parts of the j/E profile recorded after holding the potential for various times at several values at the end of anodic-going sweeps. The processes associated with the two peaks, which appear in the anodic part of the voltammogram, are assigned to the early stages of a surface oxidation. Two OHad states are suggested based on the existence of reversibly or weakly bound OHad species and irreversibly or strongly bound OHad species. The reversibly bound OHad species are involved in the “normal” structure of the butterfly peak, while the irreversibly adsorbed OHad species can be obtained only by the slow diffusion of a part of the initially electrosorbed OH species from sites with low to sites with higher binding energies. The irreversibly reduced OHad species cannot be completely removed from the surface causing, therefore, some permanent transformation of the initial state of the surface. This kind of species was not detected in the area of the second oxidation peak. The phenomena observed in the reduction part of the j/E profile induced by a time effect in the second peak could be associated with a place-exchange mechanism between oxygen containing species, whatever they are, and the platinum surface.

Effect of microorganisms on the plutonium oxidation states

International Nuclear Information System (INIS)

Lukšienė, Benedikta; Druteikienė, Rūta; Pečiulytė, Dalia; Baltrūnas, Dalis; Remeikis, Vidmantas; Paškevičius, Algimantas

2012-01-01

Particular microbes from substrates at the low-level radioactive waste repository in the Ignalina NPP territory were exposed to 239 Pu (IV) at low pH under aerobic conditions. Pu(III) and Pu(IV) were separated and quantitatively evaluated using the modified anion exchange method and alpha spectrometry. Tested bacteria Bacillus mycoides and Serratia marcescens were more effective in Pu reduction than Rhodococcus fascians. Fungi Paecillomyces lilacinus and Absidia spinosa var. spinosa as well as bacterium Rhodococcus fascians did not alter the plutonium oxidation state. - Highlights: ► Particular microbes from low-level radioactive waste repository were exposed to Pu (IV). ► Some tested bacteria induced slight Pu (IV) reduction at low pH under aerobic conditions. ► Tested fungi did not show peculiarities to alter Pu oxidation state. ► The modified radiochemical method was applied to differentiate Pu oxidation states.

Effects of heat-activated persulfate oxidation on soil microorganisms

DEFF Research Database (Denmark)

Tsitonaki, Aikaterini; Smets, Barth F.; Bjerg, Poul Løgstrup

2008-01-01

/L). The results emphasize the necessity of using multiple toxicity assays and indigenous cultures in order to realistically assess the potential effects of in situ chemical oxidation on soil microorganisms. A comparison to other studies suggests that the effects of activated persulfate on soil microorganisms...

Effects of p-Synephrine and Caffeine Ingestion on Substrate Oxidation during Exercise.

Science.gov (United States)

Gutiérrez-Hellín, Jorge; Del Coso, Juan

2018-04-27

Caffeine and p-synephrine are substances usually included in commercially-available products for weight loss because of their purported thermogenic effects. However, scientific information is lacking about the effects of combining these substances on substrate oxidation during exercise. The purpose of this investigation was to determine the isolated and combined effects of p-synephrine and caffeine on fat oxidation rate during exercise. In a double-blind randomized experiment, 13 healthy subjects participated in 4 experimental trials after the ingestion of a capsule containing either a placebo, 3 mg·kg of caffeine, 3 mg·kg of p-synephrine, or the combination of these doses of caffeine and p-synephrine. Energy expenditure and substrate oxidation rates were measured by indirect calorimetry during a cycle ergometer ramp test from 30 to 90% of VO2max. In comparison to the placebo, the ingestion of caffeine, p-synephrine, or p-synephrine+caffeine did not alter total energy expenditure or heart rate during the whole exercise test. However, the ingestion of caffeine (0.44 ± 0.15 g·min, P = 0.03), p-synephrine (0.43 ± 0.19 g·min, P < 0.01), and p-synephrine+caffeine (0.45 ± 0.15 g·min, P = 0.02) increased the maximal rate of fat oxidation during exercise when compared to the placebo (0.30 ± 0.12 g·min). The exercise intensity that elicited maximal fat oxidation was similar in all trials (~46.2 ± 10.2% of VO2max). Caffeine, p-synephrine and p-synephrine+caffeine increased the maximal rate of fat oxidation during exercise compared to a placebo, without modifying energy expenditure or heart rate. However, the co-ingestion of p-synephrine and caffeine did not present an additive effect to further increase fat oxidation during exercise.

Fast Appearance Modeling for Automatic Primary Video Object Segmentation.

Science.gov (United States)

Yang, Jiong; Price, Brian; Shen, Xiaohui; Lin, Zhe; Yuan, Junsong

2016-02-01

Automatic segmentation of the primary object in a video clip is a challenging problem as there is no prior knowledge of the primary object. Most existing techniques thus adapt an iterative approach for foreground and background appearance modeling, i.e., fix the appearance model while optimizing the segmentation and fix the segmentation while optimizing the appearance model. However, these approaches may rely on good initialization and can be easily trapped in local optimal. In addition, they are usually time consuming for analyzing videos. To address these limitations, we propose a novel and efficient appearance modeling technique for automatic primary video object segmentation in the Markov random field (MRF) framework. It embeds the appearance constraint as auxiliary nodes and edges in the MRF structure, and can optimize both the segmentation and appearance model parameters simultaneously in one graph cut. The extensive experimental evaluations validate the superiority of the proposed approach over the state-of-the-art methods, in both efficiency and effectiveness.

Effects of silver nanoparticles to soil invertebrates: Oxidative stress biomarkers in Eisenia fetida

International Nuclear Information System (INIS)

Gomes, Susana I.L.; Hansen, Ditte; Scott-Fordsmand, Janeck J.; Amorim, Mónica J.B.

2015-01-01

Silver nanoparticles (Ag-NPs) are among the most produced NPs worldwide having several applications in consumer products. Ag-NPs are known to cause oxidative stress in several organisms and cell lines, however comparatively less information is available regarding their effects on soil living invertebrates. The purpose of this study was to investigate if Ag-NPs cause oxidative stress on soil invertebrates. The model soil species Eisenia fetida was used. Our results showed that total glutathione (TG) is the first mechanism triggered by Ag-NPs, followed by glutathione peroxidase (GPx) and glutathione reductase (GR), however oxidative damage was observed for higher doses and exposure time (increased lipid peroxidation, LPO). AgNO 3 exposure caused impairment in GPx and glutathione-S-transferase (GST), probably as result of the higher bioavailability of Ag in the salt-form. The current results indicate that effects are partly caused by Ag ions released from Ag-NPs, but specific particle effects cannot be excluded. - Highlights: • Oxidative stress of Ag-NPs and AgNO 3 was assessed in Eisenia fetida. • Both Ag forms induced oxidative damage (LPO) via different mechanisms. • Ag-NPs activated total glutathione, followed by GPx and GR. • AgNO 3 impaired GPx and GST. • Overall results indicated effects from Ag ionization and NPs specific effects. - Oxidative stress to Ag in Eisenia fetida occurs via different mechanisms for Ag nanoparticles and AgNO 3

Modes of oxidation in SiC-reinforced mullite/ZrO2 composites: Oxidation vs depth behavior

International Nuclear Information System (INIS)

Lin, C.C.; Ruh, R.

1999-01-01

Two basic oxidation modes of composites with oxidizing particles in a non-oxidizing matrix have been observed. Mode I is defined as the complete oxidation of all the particles within an outer layer of the composite, while mode II exhibits partial oxidation of the particles, deep into the composite. Using microscopic observations to plot the silica layer thickness on particles (whiskers) vs the depth of the particles (whiskers) below the composite surface is proposed as a powerful means of categorizing and quantifying actual oxidation modes. Thus, mullite/SiC-whisker composites were found to have mode I oxidation behavior, while certain (mullite + ZrO 2 )/SiC-whisker composites were found to exhibit mode II behavior, followed by a mixed mode after severe exposures. It is proposed that mode II behavior appears when oxygen diffusivity in the matrix is much higher than that in the product oxide layer

Body Image and the Appearance Culture Among Adolescent Girls and Boys: An Examination of Friend Conversations, Peer Criticism, Appearance Magazines, and the Internalization of Appearance Ideals

Science.gov (United States)

Jones, Diane Carlson; Vigfusdottir, Thorbjorg Helga; Lee, Yoonsun

2004-01-01

This research evaluates the contributions of three dimensions of appearance culture (appearance magazine exposure, appearance conversations with friends, and peer appearance criticism) and body mass index (BMI) to internalization of appearance ideals and body image dissatisfaction. Four hundred thirty-three girls and 347 boys in Grades 7 through…

Effect of metallurgical factors on the oxidation of Zr - 1% Nb Alloy

International Nuclear Information System (INIS)

Soliman, H.M.

1979-01-01

The importance of study of the oxidation behaviour of zirconium and its niobium alloys arises from their suitability as cladding and structural materials in nuclear reactors and their use in oxidizing conditions. This work includes the oxidation behaviour of Zr - 1%Nb in both air and steam, and to less extent, zirconium was investigated in air. The effect of 1%Nb, oxidizing medium, fluoride ions contamination and thermal cycling on the oxidation behaviour has been investigated using weight gain, plastic deformation generated during oxidation, electron microscopy , metallography and X- ray techniques. The kinetics of oxidation of Zr-1%Nb alloy have been studied in the temperature range 500 - 1200 degree C and 500 - 900 degree C in both air and steam, respectively. The oxidation rate increases with temperature, Initially, the reaction proceeds with a decreasing rate ( mainly parabolic) followed by transition to a linear or acceleration, indicating breakaway. As the oxidation temperature increases, the time to breakaway transition decreases

Inhibition effect on lipid oxidation of irradiated pork by adding hawthorn flavonoid extract

International Nuclear Information System (INIS)

Wang Xiaoming; Liu Chao; Cao Lei; Li Kexi

2011-01-01

The antioxidant activity of hawthorn flavonoid extract and its inhibition effect on irradiated pork lipid oxidant were investigated. The results showed that hawthorn flavonoids had efficient scavenging effect on DPPH free radicals (DPPH ·), and the scavenging rate reached 56% while 2 ml of 0.035 mg/ml hawthorn flavonoid extract was added. Hawthorn flavonoid extract can inhibition the lipid oxidation of irradiated pork effectively and it showed a stronger inhibition ability while the hawthorn flavonoid extract were used together with Vc. It is concluded that can decrease the lipid oxidation of pork, hawthorn flavonoid extract is a remarkable natural antioxidant. (authors)

Effects of tunnel oxide process on SONOS flash memory characteristics

International Nuclear Information System (INIS)

Li, Dong Hua; Park, Il Han; Yun, Jang-Gn; Park, Byung-Gook

2010-01-01

In this paper, various process conditions of tunnel oxides are applied in SONOS flash memory to investigate their effects on charge transport during the program/erase operations. We focus the key point of analysis on Fermi-level (E F ) variation at the interface of silicon substrate and tunnel oxide. The Si-O chemical bonding information which describes the interface oxidation states at the Si/SiO 2 is obtained by the core-level X-ray photoelectron spectroscopy (XPS). Moreover, relative E F position is determined by measuring the Si 2p energy shift from XPS spectrums. Experimental results from memory characteristic measurement show that MTO tunnel oxide structure exhibits faster erase speed, and larger memory window during P/E cycle compared to FTO and RTO tunnel oxide structures. Finally, we examine long-term charge retention characteristic and find that the memory windows of all the capacitors remain wider than 2 V after 10 5 s.

Oxidative Decarboxylation of Levulinic Acid by Cupric Oxides

Directory of Open Access Journals (Sweden)

Lu Lin

2010-11-01

Full Text Available In this paper, cupric oxides was found to effectively oxidize levulinic acid (LA and lead to the decarboxylation of levulinic acid to 2-butanone. The effects of cupric oxide dosage, reaction time and initial pH value were investigated in batch experiments and a plausible mechanism was proposed. The results showed that LA decarboxylation over cupric oxides at around 300 °C under acidic conditions produced the highest yield of butanone (67.5%. In order to elucidate the catalytic activity of cupric oxides, XRD, AFM, XPS and H2-TPR techniques was applied to examine their molecular surfaces and their effects on the reaction process.

Nb effect in the nickel oxide-catalyzed low-temperature oxidative dehydrogenation of ethane

KAUST Repository

Zhu, Haibo

2012-01-01

A method for the preparation of NiO and Nb-NiO nanocomposites is developed, based on the slow oxidation of a nickel-rich Nb-Ni gel obtained in citric acid. The resulting materials have higher surface areas than those obtained by the classical evaporation method from nickel nitrate and ammonium niobium oxalate. These consist in NiO nanocrystallites (7-13 nm) associated, at Nb contents >3 at.%., with an amorphous thin layer (1-2 nm) of a niobium-rich mixed oxide with a structure similar to that of NiNb 2O 6. Unlike bulk nickel oxides, the activity of these nanooxides for low-temperature ethane oxidative dehydrogenation (ODH) has been related to their redox properties. In addition to limiting the size of NiO crystallites, the presence of the Nb-rich phase also inhibits NiO reducibility. At Nb content >5 at.%, Nb-NiO composites are thus less active for ethane ODH but more selective, indicating that the Nb-rich phase probably covers part of the unselective, non-stoichiometric, active oxygen species of NiO. This geometric effect is supported by high-resolution transmission electron microscopy observations. The close interaction between NiO and the thin Nb-rich mixed oxide layer, combined with possible restructuration of the nanocomposite under ODH conditions, leads to significant catalyst deactivation at high Nb loadings. Hence, the most efficient ODH catalysts obtained by this method are those containing 3-4 at.% Nb, which combine high activity, selectivity, and stability. The impact of the preparation method on the structural and catalytic properties of Nb-NiO nanocomposites suggests that further improvement in NiO-catalyzed ethane ODH can be expected upon optimization of the catalyst. © 2011 Elsevier Inc. All rights reserved.

Preparation of molybdenum oxide thin films by MOCVD

International Nuclear Information System (INIS)

Guerrero, R. Martinez; Garcia, J.R. Vargas; Santes, V.; Gomez, E.

2007-01-01

In this study, molybdenum oxide films were prepared in a horizontal hot-wall MOCVD apparatus using molybdenum dioxide acetylacetonate as precursor. The molybdenum precursor was synthesized from acetylacetone and molybdenum oxide powder. Thermal gravimetric (TG) and differential thermal analyses (DTA) of the precursor suggested the formation of molybdenum oxides around 430 o C (703 K). Thus, a range of deposition temperatures varying from 350 to 630 o C (623-903 K) was explored to investigate the effects on the nature of the molybdenum oxide films. X-ray diffraction (XRD) results showed that the films consisted of α-MoO 3 phase at deposition temperatures ranging from 400 to 560 o C (673-833 K). Crystalline α-MoO 3 films can be obtained from molybdenum dioxide acetylacetonate precursor, without need of a post-annealing treatment. The best crystalline quality was found in films having needle-like crystallites grown at deposition temperature of about 560 o C (833 K), which exhibit a strong (0 1 0) preferred orientation and a transparent visual appearance

Preparation of molybdenum oxide thin films by MOCVD

Energy Technology Data Exchange (ETDEWEB)

Guerrero, R. Martinez [Depto. de Ingenieria Metalurgica, ESIQIE-IPN, Mexico 07300, D.F. (Mexico); Garcia, J.R. Vargas [Depto. de Ingenieria Metalurgica, ESIQIE-IPN, Mexico 07300, D.F. (Mexico)]. E-mail: rvargasga@ipn.mx; Santes, V. [CIIEMAD-IPN, Miguel Othon de Mendizabal 485, Mexico 07700, D.F. (Mexico); Gomez, E. [Instituto de Quimica-UNAM, Circuito Exterior-Ciudad Universitaria, Mexico 04510, D.F. (Mexico)

2007-05-31

In this study, molybdenum oxide films were prepared in a horizontal hot-wall MOCVD apparatus using molybdenum dioxide acetylacetonate as precursor. The molybdenum precursor was synthesized from acetylacetone and molybdenum oxide powder. Thermal gravimetric (TG) and differential thermal analyses (DTA) of the precursor suggested the formation of molybdenum oxides around 430 {sup o}C (703 K). Thus, a range of deposition temperatures varying from 350 to 630 {sup o}C (623-903 K) was explored to investigate the effects on the nature of the molybdenum oxide films. X-ray diffraction (XRD) results showed that the films consisted of {alpha}-MoO{sub 3} phase at deposition temperatures ranging from 400 to 560 {sup o}C (673-833 K). Crystalline {alpha}-MoO{sub 3} films can be obtained from molybdenum dioxide acetylacetonate precursor, without need of a post-annealing treatment. The best crystalline quality was found in films having needle-like crystallites grown at deposition temperature of about 560 {sup o}C (833 K), which exhibit a strong (0 1 0) preferred orientation and a transparent visual appearance.

Effect of temperature on the electro-oxidation of ethanol on platinum

OpenAIRE

Camargo, Ana Paula M.; Previdello, Bruno A. F.; Varela, Hamilton; Gonzalez, Ernesto R.

2010-01-01

We present in this work an experimental investigation of the effect of temperature (from 25 to 180 ºC) in the electro-oxidation of ethanol on platinum in two different phosphoric acid concentrations. We observed that the onset potential for ethanol electro-oxidation shifts to lower values and the reaction rates increase as temperature is increased for both electrolytes. The results were rationalized in terms of the effect of temperature on the adsorption of reaction intermediates, poisons, an...

Effect of dietary α-tocopherol + ascorbic acid, selenium, and iron on oxidative stress in sub-yearling Chinook salmon (Oncorhynchus tshawytscha Walbaum)

Science.gov (United States)

Welker, T.L.; Congleton, J.L.

2009-01-01

A three-variable central composite design coupled with surface-response analysis was used to examine the effects of dietary ??-tocopherol + ascorbic acid (TOCAA), selenium (Se), and iron (Fe) on indices of oxidative stress in juvenile spring Chinook salmon. Each dietary factor was tested at five levels for a total of fifteen dietary combinations (diets). Oxidative damage in liver and kidney (lipid peroxidation, protein carbonyls) and erythrocytes (erythrocyte resistance to peroxidative lysis, ERPL) was determined after feeding experimental diets for 16 (early December) and 28 (early March) weeks. Only TOCAA influenced oxidative stress in this study, with most measures of oxidative damage decreasing (liver lipid peroxidation in December and March; ERPL in December; liver protein carbonyl in March) with increasing levels of TOCAA. We also observed a TOCAA-stimulated increase in susceptibility of erythrocytes to peroxidative lysis in March at the highest levels of TOCAA. The data suggest that under most circumstances a progressive decrease in oxidative stress occurs as dietary TOCAA increases, but higher TOCAA concentrations can stimulate oxidative damage in some situations. Higher levels of TOCAA in the diet were required in March than in December to achieve comparable levels of protection against oxidative damage, which may have been due to physiological changes associated with the parr-smolt transformation. Erythrocytes appeared to be more sensitive to variation in dietary levels of TOCAA than liver and kidney tissues. Using the March ERPL assay results as a baseline, a TOCAA level of approximately 350-600 mg/kg diet would provide adequate protection against lipid peroxidation under most circumstances in juvenile Chinook salmon. ?? 2008 The Authors.

Tetrahydrobiopterin Has a Glucose-Lowering Effect by Suppressing Hepatic Gluconeogenesis in an Endothelial Nitric Oxide Synthase–Dependent Manner in Diabetic Mice

Science.gov (United States)

Abudukadier, Abulizi; Fujita, Yoshihito; Obara, Akio; Ohashi, Akiko; Fukushima, Toru; Sato, Yuichi; Ogura, Masahito; Nakamura, Yasuhiko; Fujimoto, Shimpei; Hosokawa, Masaya; Hasegawa, Hiroyuki; Inagaki, Nobuya

2013-01-01

Endothelial nitric oxide synthase (eNOS) dysfunction induces insulin resistance and glucose intolerance. Tetrahydrobiopterin (BH4) is an essential cofactor of eNOS that regulates eNOS activity. In the diabetic state, BH4 is oxidized to 7,8-dihydrobiopterin, which leads to eNOS dysfunction owing to eNOS uncoupling. The current study investigates the effects of BH4 on glucose metabolism and insulin sensitivity in diabetic mice. Single administration of BH4 lowered fasting blood glucose levels in wild-type mice with streptozotocin (STZ)-induced diabetes and alleviated eNOS dysfunction by increasing eNOS dimerization in the liver of these mice. Liver has a critical role in glucose-lowering effects of BH4 through suppression of hepatic gluconeogenesis. BH4 activated AMP kinase (AMPK), and the suppressing effect of BH4 on gluconeogenesis was AMPK-dependent. In addition, the glucose-lowering effect and activation of AMPK by BH4 did not appear in mice with STZ-induced diabetes lacking eNOS. Consecutive administration of BH4 in ob/ob mice ameliorated glucose intolerance and insulin resistance. Taken together, BH4 suppresses hepatic gluconeogenesis in an eNOS-dependent manner, and BH4 has a glucose-lowering effect as well as an insulin-sensitizing effect in diabetic mice. BH4 has potential in the treatment of type 2 diabetes. PMID:23649519

UNS S31603 Stainless Steel Tungsten Inert Gas Welds Made with Microparticle and Nanoparticle Oxides

Directory of Open Access Journals (Sweden)

Kuang-Hung Tseng

2014-06-01

Full Text Available The purpose of this study was to investigate the difference between tungsten inert gas (TIG welding of austenitic stainless steel assisted by microparticle oxides and that assisted by nanoparticle oxides. SiO2 and Al2O3 were used to investigate the effects of the thermal stability and the particle size of the activated compounds on the surface appearance, geometric shape, angular distortion, delta ferrite content and Vickers hardness of the UNS S31603 stainless steel TIG weld. The results show that the use of SiO2 leads to a satisfactory surface appearance compared to that of the TIG weld made with Al2O3. The surface appearance of the TIG weld made with nanoparticle oxide has less flux slag compared with the one made with microparticle oxide of the same type. Compared with microparticle SiO2, the TIG welding with nanoparticle SiO2 has the potential benefits of high joint penetration and less angular distortion in the resulting weldment. The TIG welding with nanoparticle Al2O3 does not result in a significant increase in the penetration or reduction of distortion. The TIG welding with microparticle or nanoparticle SiO2 uses a heat source with higher power density, resulting in a higher ferrite content and hardness of the stainless steel weld metal. In contrast, microparticle or nanoparticle Al2O3 results in no significant difference in metallurgical properties compared to that of the C-TIG weld metal. Compared with oxide particle size, the thermal stability of the oxide plays a significant role in enhancing the joint penetration capability of the weld, for the UNS S31603 stainless steel TIG welds made with activated oxides.

Effects of mechanical force on grain structures of friction stir welded oxide dispersion strengthened ferritic steel

International Nuclear Information System (INIS)

Han, Wentuo; Kimura, Akihiko; Tsuda, Naoto; Serizawa, Hisashi; Chen, Dongsheng; Je, Hwanil; Fujii, Hidetoshi; Ha, Yoosung; Morisada, Yoshiaki; Noto, Hiroyuki

2014-01-01

The weldability of oxide dispersion strengthened (ODS) ferritic steels is a critical obstructive in the development and use of these steels. Friction stir welding has been considered to be a promising way to solve this problem. The main purpose of this work was to reveal the effects of mechanical force on grain structures of friction stir welded ODS ferritic steel. The grain appearances and the misorientation angles of grain boundaries in different welded zones were investigated by the electron backscatter diffraction (EBSD). Results showed that the mechanical force imposed by the stir tool can activate and promote the recrystallization characterized by the transformation of boundaries from LABs to HABs, and contribute to the grain refinement. The type of recrystallization in the stir zone can be classified as the continuous dynamic recrystallization (CDRX)

Effects of mechanical force on grain structures of friction stir welded oxide dispersion strengthened ferritic steel

Energy Technology Data Exchange (ETDEWEB)

Han, Wentuo, E-mail: hanwentuo@hotmail.com [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Kimura, Akihiko [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Tsuda, Naoto [Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Serizawa, Hisashi [Joining and Welding Research Institute, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Chen, Dongsheng [Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Je, Hwanil [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Fujii, Hidetoshi [Joining and Welding Research Institute, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Ha, Yoosung [Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Morisada, Yoshiaki [Joining and Welding Research Institute, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Noto, Hiroyuki [Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan)

2014-12-15

The weldability of oxide dispersion strengthened (ODS) ferritic steels is a critical obstructive in the development and use of these steels. Friction stir welding has been considered to be a promising way to solve this problem. The main purpose of this work was to reveal the effects of mechanical force on grain structures of friction stir welded ODS ferritic steel. The grain appearances and the misorientation angles of grain boundaries in different welded zones were investigated by the electron backscatter diffraction (EBSD). Results showed that the mechanical force imposed by the stir tool can activate and promote the recrystallization characterized by the transformation of boundaries from LABs to HABs, and contribute to the grain refinement. The type of recrystallization in the stir zone can be classified as the continuous dynamic recrystallization (CDRX)

Oxidative treatment of a waste water stream from a molasses processing using ozone and advanced oxidation technologies

International Nuclear Information System (INIS)

Gehringer, P.; Szinovatz, W.; Eschweiler, H.; Haberl, R.

1994-08-01

The discoloration of a biologically pretreated waste water stream from a molasses processing by ozonation and two advanced oxidation processes (O 3 /H 2 O 2 and O 3 /γ-irradiation, respectively) was studied. Colour removal occurred with all three processes with almost the same efficiency. The main difference of the methods applied was reflected by the BOD increase during the discoloration period. By ozonation it was much higher than by AOPs but it also appeared with AOPs. AOPs were, therefore, not apt for an effective BOD control during discoloration. (authors)

Effect of microorganisms on the plutonium oxidation states

Energy Technology Data Exchange (ETDEWEB)

Luksiene, Benedikta, E-mail: bena@ar.fi.lt [Center for Physical Sciences and Technology, Savanoriu ave 231, LT-02300 Vilnius (Lithuania); Druteikiene, Ruta [Center for Physical Sciences and Technology, Savanoriu ave 231, LT-02300 Vilnius (Lithuania); Peciulyte, Dalia [Nature Research Centre, Akademijos street 2, LT-08412 Vilnius (Lithuania); Baltrunas, Dalis; Remeikis, Vidmantas [Center for Physical Sciences and Technology, Savanoriu ave 231, LT-02300 Vilnius (Lithuania); Paskevicius, Algimantas [Nature Research Centre, Akademijos street 2, LT-08412 Vilnius (Lithuania)

2012-03-15

Particular microbes from substrates at the low-level radioactive waste repository in the Ignalina NPP territory were exposed to {sup 239}Pu (IV) at low pH under aerobic conditions. Pu(III) and Pu(IV) were separated and quantitatively evaluated using the modified anion exchange method and alpha spectrometry. Tested bacteria Bacillus mycoides and Serratia marcescens were more effective in Pu reduction than Rhodococcus fascians. Fungi Paecillomyces lilacinus and Absidia spinosa var. spinosa as well as bacterium Rhodococcus fascians did not alter the plutonium oxidation state. - Highlights: Black-Right-Pointing-Pointer Particular microbes from low-level radioactive waste repository were exposed to Pu (IV). Black-Right-Pointing-Pointer Some tested bacteria induced slight Pu (IV) reduction at low pH under aerobic conditions. Black-Right-Pointing-Pointer Tested fungi did not show peculiarities to alter Pu oxidation state. Black-Right-Pointing-Pointer The modified radiochemical method was applied to differentiate Pu oxidation states.

Influence of Nitinol wire surface treatment on oxide thickness and composition and its subsequent effect on corrosion resistance and nickel ion release.

Science.gov (United States)

Clarke, B; Carroll, W; Rochev, Y; Hynes, M; Bradley, D; Plumley, D

2006-10-01

Medical implants and devices are now used successfully in surgical procedures on a daily basis. Alloys of nickel and titanium, and in particular Nitinol are of special interest in the medical device industry, because of their shape memory and superelastic properties. The corrosion behavior of nitinol in the body is also of critical importance because of the known toxicological effects of nickel. The stability of a NiTi alloy in the physiological environment is dependant primarily on the properties of the mostly TiO(2) oxide layer that is present on the surface. For the present study, a range of nitinol wires have been prepared using different drawing processes and a range of surface preparation procedures. It is clear from the results obtained that the wire samples with very thick oxides also contain a high nickel content in the oxide layer. The untreated samples with the thicker oxides show the lowest pitting potential values and greater nickel release in both long and short-term experiments. It was also found that after long-term immersion tests breakdown potentials increased for samples that exhibited lower values initially. From these results it would appear that surface treatment is essential for the optimum bioperformance of nitinol. (c) 2006 Wiley Periodicals, Inc

Effect of antimony oxide on magnesium vanadates for the selective oxidation of hydrogen sulfide to sulfur

Energy Technology Data Exchange (ETDEWEB)

Li, K.T.; Chi, Z.H. [Department of Chemical Engineering, Tunghai University, ROC Taichung (Taiwan)

2001-05-17

The effect of antimony oxide addition to MgV{sub 2}O{sub 6} and Mg{sub 3}V{sub 2}O{sub 8} was studied in the selective oxidation of hydrogen sulfide to sulfur. Significant improvements in sulfur selectivity and yield were observed for the uncalcined mechanical mixtures of magnesium vanadates with {alpha}-Sb{sub 2}O{sub 4}. Calcination of the mechanical mixtures resulted in the much stronger synergy in catalytic activity and sulfur selectivity. For the uncalcined samples, XRD, TPR and XPS studies indicated that antimony reduction behaviors in the mechanical mixtures differed very much from those in {alpha}-Sb{sub 2}O{sub 4} alone, suggested that their selectivity improvements might be due to the interactions (probably oxygen transfer) between {alpha}-Sb{sub 2}O{sub 4} and magnesium vanadates. For the calcined samples, XRD results indicated that their better catalytic performances in H{sub 2}S oxidation were primarily attributed to the formation of VSbO{sub 4} compound from antimony oxide and magnesium vanadates.

Effects of increased meal frequency on fat oxidation and perceived hunger.

Science.gov (United States)

Ohkawara, Kazunori; Cornier, Marc-Andre; Kohrt, Wendy M; Melanson, Edward L

2013-02-01

Consuming smaller, more frequent meals is often advocated as a means of controlling body weight, but studies demonstrating a mechanistic effect of this practice on factors associated with body weight regulation are lacking. The purpose of this study was to compare the effect of consuming three (3M) vs. six meals (6M) per day on 24-h fat oxidation and subjective ratings of hunger. Lean (body mass index meal frequency from three to six per day has no significant effect on 24-h fat oxidation, but may increase hunger and the desire to eat. Copyright © 2012 The Obesity Society.

Thermal gradient effects on the oxidation of Zircaloy fuel cladding

International Nuclear Information System (INIS)

Klein, A.C.; Reyes, J.N. Jr.; Maguire, M.A.

1990-01-01

A Thermal Gradient Test Facility (TGTF) has been designed and constructed to measure the thermal gradient effect on pressurized water reactor (PWR) fuel rod cladding. The TGTF includes a heat flux simulator assembly capable of producing a wide range of PWR operating conditions including water flow velocities and temperatures, water chemistry conditions, cladding temperatures, and heat fluxes ranging to 160 W/cm 2 . It is fully instrumented including a large number of thermocouples both inside the water flow channel and inside the cladding. Two test programs are in progress. First, cladding specimens are pre-oxidized in air at 500 deg. C and in 400 deg. C steam for various lengths of time to develop a range of uniform oxide thicknesses from 1 to 60 micrometers. The pre-oxidized specimens are placed in the TGTF to characterize the oxide thermal conductivity under a variety of water flow and heat flux conditions. Second, to overcome the long exposure times required under typical PWR conditions a series of tests with the addition of high concentrations of lithium hydroxide to the water are being considered. Static autoclave tests have been conducted with lithium hydroxide concentrations ranging from 0 to 2 moles per liter at 300, 330, and 360 deg. C for up to 36 hours. Results for zircaloy-4 show a considerable increase in the weight gain for the exposed samples with oxidation rate enhancement factors as high as 70 times that of pure water. Operation of the TGTF with elevated lithium hydroxide levels will yield real-time information concerning the effects of a heat flux on the oxidation kinetics of zircaloy fuel rod cladding. (author). 5 refs, 5 figs, 2 tabs

Effect of Myricetin, Pyrogallol, and Phloroglucinol on Yeast Resistance to Oxidative Stress

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Vanda Mendes

2015-01-01

Full Text Available The health beneficial effects of dietary polyphenols have been attributed to their intrinsic antioxidant activity, which depends on the structure of the compound and number of hydroxyl groups. In this study, the protective effects of pyrogallol, phloroglucinol, and myricetin on the yeast Saccharomyces cerevisiae were investigated. Pyrogallol and myricetin, which have a pyrogallol structure in the B ring, increased H2O2 resistance associated with a reduction in intracellular oxidation and protein carbonylation, whereas phloroglucinol did not exert protective effects. The acquisition of oxidative stress resistance in cells pretreated with pyrogallol and myricetin was not associated with an induction of endogenous antioxidant defences as assessed by the analysis of superoxide dismutase and catalase activities. However, myricetin, which provided greater stress resistance, prevented H2O2-induced glutathione oxidation. Moreover, myricetin increased the chronological lifespan of yeast lacking the mitochondrial superoxide dismutase (Sod2p, which exhibited a premature aging phenotype and oxidative stress sensitivity. These findings show that the presence of hydroxyl groups in the ortho position of the B ring in pyrogallol and myricetin contributes to the antioxidant protection afforded by these compounds. In addition, myricetin may alleviate aging-induced oxidative stress, particularly when redox homeostasis is compromised due to downregulation of endogenous defences present in mitochondria.

Oxidative Metabolites of Curcumin Poison Human Type II Topoisomerases†

Science.gov (United States)

Ketron, Adam C.; Gordon, Odaine N.; Schneider, Claus; Osheroff, Neil

2013-01-01

The polyphenol curcumin is the principal flavor and color component of the spice turmeric. Beyond its culinary uses, curcumin is believed to positively impact human health and displays antioxidant, anti-inflammatory, antibacterial, and chemopreventive properties. It also is in clinical trials as an anticancer agent. In aqueous solution at physiological pH, curcumin undergoes spontaneous autoxidation that is enhanced by oxidizing agents. The reaction proceeds through a series of quinone methide and other reactive intermediates to form a final dioxygenated bicyclopentadione product. Several naturally occurring polyphenols that can form quinones have been shown to act as topoisomerase II poisons (i.e., increase levels of topoisomerase II-mediated DNA cleavage). Because several of these compounds have chemopreventive properties, we determined the effects of curcumin, its oxidative metabolites, and structurally related degradation products (vanillin, ferulic acid, and feruloylmethane), on the DNA cleavage activities of human topoisomerase IIα and IIβ. Intermediates in the curcumin oxidation pathway increased DNA scission mediated by both enzymes ~4-5–fold. In contrast, curcumin and the bicyclopentadione, as well as vanillin, ferulic acid, and feruloylmethane, had no effect on DNA cleavage. As found for other quinone-based compounds, curcumin oxidation intermediates acted as redox-dependent (as opposed to interfacial) topoisomerase II poisons. Finally, under conditions that promote oxidation, the dietary spice turmeric enhanced topoisomerase II-mediated DNA cleavage. Thus, even within the more complex spice formulation, oxidized curcumin intermediates appear to function as topoisomerase II poisons. PMID:23253398

Kinetics of oxidic phase dissolution in acids

International Nuclear Information System (INIS)

Gorichev, I.G.; Kipriyanov, N.A.

1981-01-01

The critical analysis of the experimental data on dissolution kinetics of metal oxides (BeO, V 2 O 5 , UO 2 , Nb 2 O 5 , Ta 2 O 5 etc.) in acid media is carried out. Kinetic peculiarities of oxide dissolution are explained on the basis of the notions of electron- proton theory. It is established that the surface nonstoichiometric ccomposition of oxide phase and potential jump, appearing on the interface of the oxide-electrolyte phase are the important factors, determining the dissolution rate of a solid phase. The dissolution rate of metal oxides is limited by the transition of protons into the solid oxide phase. Morphological models of heterogeneous kinetics are used when explaining kinetic regularities of oxide dissolution process [ru

Anti-oxidant effect of gold nanoparticles restrains hyperglycemic conditions in diabetic mice

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Eom SooHyun

2010-07-01

Full Text Available Abstract Background Oxidative stress is imperative for its morbidity towards diabetic complications, where abnormal metabolic milieu as a result of hyperglycemia, leads to the onset of several complications. A biological antioxidant capable of inhibiting oxidative stress mediated diabetic progressions; during hyperglycemia is still the need of the era. The current study was performed to study the effect of biologically synthesized gold nanoparticles (AuNPs to control the hyperglycemic conditions in streptozotocin induced diabetic mice. Results The profound control of AuNPs over the anti oxidant enzymes such as GSH, SOD, Catalase and GPx in diabetic mice to normal, by inhibition of lipid peroxidation and ROS generation during hyperglycemia evidence their anti-oxidant effect during hyperglycemia. The AuNPs exhibited an insistent control over the blood glucose level, lipids and serum biochemical profiles in diabetic mice near to the control mice provokes their effective role in controlling and increasing the organ functions for better utilization of blood glucose. Histopathological and hematological studies revealed the non-toxic and protective effect of the gold nanoparticles over the vital organs when administered at dosage of 2.5 mg/kilogram.body.weight/day. ICP-MS analysis revealed the biodistribution of gold nanoparticles in the vital organs showing accumulation of AuNPs in the spleen comparatively greater than other organs. Conclusion The results obtained disclose the effectual role of AuNPs as an anti-oxidative agent, by inhibiting the formation of ROS, scavenging free radicals; thus increasing the anti-oxidant defense enzymes and creating a sustained control over hyperglycemic conditions which consequently evoke the potential of AuNPs as an economic therapeutic remedy in diabetic treatments and its complications.

Theory of the Spin Galvanic Effect at Oxide Interfaces

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Seibold, Götz; Caprara, Sergio; Grilli, Marco; Raimondi, Roberto

2017-12-01

The spin galvanic effect (SGE) describes the conversion of a nonequilibrium spin polarization into a transverse charge current. Recent experiments have demonstrated a large conversion efficiency for the two-dimensional electron gas formed at the interface between two insulating oxides, LaAlO3 and SrTiO3 . Here, we analyze the SGE for oxide interfaces within a three-band model for the Ti t2 g orbitals which displays an interesting variety of effective spin-orbit couplings in the individual bands that contribute differently to the spin-charge conversion. Our analytical approach is supplemented by a numerical treatment where we also investigate the influence of disorder and temperature, which turns out to be crucial to providing an appropriate description of the experimental data.

Effect of the degree of oxidation and defects of graphene oxide on adsorption of Cu2+ from aqueous solution

Science.gov (United States)

Tan, Ping; Bi, Qi; Hu, Yongyou; Fang, Zheng; Chen, Yuancai; Cheng, Jianhua

2017-11-01

Graphene oxide (GO) is a promising adsorbent for heavy metal ions from water. However, the relationship between the degree of oxidation and defects of GO and the adsorption performance has been rarely reported. In this study, a series of GO with different degree of oxidation (GO1, GO5, GO6) and defects (GO1-GO4) were prepared by the improved Hummers method and were employed to explore the relationship between the degree of oxidation and defects of GO and the Cu2+ adsorption. The results showed that the adsorption of Cu2+ on GO was strongly dependent on the degree of oxidation and independent of the defects under various pH levels and ionic strength. The adsorption isotherms of Cu2+ on GO with different degree of oxidation and defects were well described by the Langmuir model and the maximum adsorption capacity of GO for Cu2+ increased with the improvement of the degree of oxidation but was independent of the defects, indicating that the adsorption of Cu2+ on GO was mainly proportional to the degree of oxidation but become insignificant in the structure integrity of aromatic matrixes, which might be due to the shielding effect of oxygen-containing groups. The adsorption of Cu2+ on GO with different degree of oxidation and defects reached an equilibrium state after 50 min, the adsorption kinetics followed the pseudo-second-order model and the adsorption process was controlled by the degree of oxidation.

Effective Prevention of Oxidative Deterioration of Fish Oil: Focus on Flavor Deterioration.

Science.gov (United States)

Miyashita, Kazuo; Uemura, Mariko; Hosokawa, Masashi

2018-03-25

Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), both abundant in fish oil, are known to have significant biochemical and physiological effects primarily linked to the improvement of human health, especially cardiovascular and brain health. However, the incorporation of fish oil into foods and beverages is often challenging, as fish oil is very easily oxidized and can cause undesirable flavors. This review discusses this rapid formation of the fishy and metallic off-flavors, focusing especially on an early stage of fish oil oxidation. Although oxidative stability and quality of commercialized fish oil have improved over the past few years, there is a still a problem with its application: Flavor deterioration can be found even at very low oxidation levels. This review also notes the effective way to inhibit the formation of the volatile compounds responsible for the flavor deterioration.

Appearance-based rejection sensitivity: implications for mental and physical health, affect, and motivation.

Science.gov (United States)

Park, Lora E

2007-04-01

Appearance-Based Rejection Sensitivity (Appearance-RS) is a personality-processing system characterized by anxious concerns and expectations about being rejected based on one's physical attractiveness. People differ in their sensitivity to rejection based on appearance, with consequences for mental and physical health, self-esteem, affect, and feelings of belonging. Study 1 describes the development and validation of the Appearance-RS scale, its relation to personality variables and to health-related outcomes. Study 2 provides experimental evidence that high Appearance-RS people feel more alone and rejected when asked to think about negative aspects of their appearance. Finally, Study 3 tests ways to reduce the negative effects of receiving an appearance threat among high Appearance-RS participants. Specifically, high Appearance-RS participants who engaged in self-affirmation (thought of their personal strengths) or received a secure attachment prime (thought of a close, caring relationship) were buffered from the negative effects of an appearance threat on subsequent state self-esteem and mood.

Rosemary and oxygen scavenger in active packaging for prevention of high-pressure induced lipid oxidation in pork patties

DEFF Research Database (Denmark)

Bolumar Garcia, Jose Tomas; Lapena Gomez, David; Skibsted, Leif Horsfelt

2016-01-01

Three different packaging systems: vacuum packaging, rosemary active packaging, and oxygen scavenger packaging were compared for their ability to counteract lipid oxidation in pork patties upon storage at 5 °C for 60 days following high pressure processing (HPP) (700 MPa, 10 min, 5 °C). Lipid...... oxidation was studied at the surface and the inner part by measuring secondary lipid oxidation products (TBARs) and the tendency to form radicals by electron spin resonance (ESR) spectroscopy. Lipid oxidation was lower in the inner part than at the surface for all three packaging systems. Rosemary active...... packaging was the most effective method to protect pork patties from the HPP-induced lipid oxidation, while oxygen scavenger packaging was not effective since residual oxygen remained in the package in the initial period of storage. The kinetics of the oxygen trapping by oxygen scavengers appears...

Effects of irradiation on color and lipid oxidation of prosciutto

International Nuclear Information System (INIS)

Kong Qiulian; Qi Wenyuan; Yue Ling; Chen Zhijun; Bao Yingzi; Dai Xudong; Xu Yun

2011-01-01

This study dealt with the effect of irradiation on the color, ordor and lipid oxidation of prosciutto crudo. The hams were irradiated by γ-ray and electronic beam (EB). Changes of color, ordor, TBA value (TBARS), peroxide value (POV), carbonyl value and conjugated diene value were analyzed and compared with nonirradiated hams. Results showed that color index (a * ) of control, γ-ray irradiated and EB irradiated were 14.39, 9.45 and 11.71 respectively. γ-ray irradiation had been shown to have apparently detrimental effect on the color and ordor of hams, while EB irradiation had little detrimental effect. Irradiation increased POV and conjugated diene value, but the amounts of lipid oxidation products (TBARS, carbonyl value) were less than nonirradiated hams. (authors)

Anti-Oxidant effects of pomegranate juice on Saccharomyces ...

African Journals Online (AJOL)

Conclusion: Pomegranate juice has a positive effect on fatty acid, vitamin and protein synthesis by Saccharomyces cerevisiae. Accordingly, we believe that it has significantly decreased oxidative damage thereby making a positive impact on yeast development. Key words: Pomegranate juice, SDS-PAGE, fatty acid, vitamin.

Bilirubin and its oxidation products damage brain white matter

Science.gov (United States)

Lakovic, Katarina; Ai, Jinglu; D'Abbondanza, Josephine; Tariq, Asma; Sabri, Mohammed; Alarfaj, Abdullah K; Vasdev, Punarjot; Macdonald, Robert Loch

2014-01-01

Brain injury after intracerebral hemorrhage (ICH) occurs in cortex and white matter and may be mediated by blood breakdown products, including hemoglobin and heme. Effects of blood breakdown products, bilirubin and bilirubin oxidation products, have not been widely investigated in adult brain. Here, we first determined the effect of bilirubin and its oxidation products on the structure and function of white matter in vitro using brain slices. Subsequently, we determined whether these compounds have an effect on the structure and function of white matter in vivo. In all, 0.5 mmol/L bilirubin treatment significantly damaged both the function and the structure of myelinated axons but not the unmyelinated axons in brain slices. Toxicity of bilirubin in vitro was prevented by dimethyl sulfoxide. Bilirubin oxidation products (BOXes) may be responsible for the toxicity of bilirubin. In in vivo experiments, unmyelinated axons were found more susceptible to damage from bilirubin injection. These results suggest that unmyelinated axons may have a major role in white-matter damage in vivo. Since bilirubin and BOXes appear in a delayed manner after ICH, preventing their toxic effects may be worth investigating therapeutically. Dimethyl sulfoxide or its structurally related derivatives may have a potential therapeutic value at antagonizing axonal damage after hemorrhagic stroke. PMID:25160671

Implications of red Panax ginseng in oxidative stress associated chronic diseases

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Yoon-Mi Lee

2017-04-01

Full Text Available The steaming process of Panax ginseng has been reported to increase its major known bioactive components, ginsenosides, and, therefore, its biological properties as compared to regular Panax ginseng. Biological functions of red Panax ginseng attenuating pro-oxidant environments associated with chronic diseases are of particular interest, since oxidative stress can be a key contributor to the pathogenesis of chronic diseases. Additionally, proper utilization of various biomarkers for evaluating antioxidant activities in natural products, such as ginseng, can also be important to providing validity to their activities. Thus, studies on the effects of red ginseng against various diseases as determined in cell lines, animal models, and humans were reviewed, along with applied biomarkers for verifying such effects. Limitations and future considerations of studying red ginseng were been discussed. Although further clinical studies are warranted, red ginseng appears to be beneficial for attenuating disease-associated symptoms via its antioxidant activities, as well as for preventing oxidative stress-associated chronic diseases.

Protective Effects of Alkaloid Compounds from Nelumbinis Plumula on tert-Butyl Hydroperoxide-Induced Oxidative Stress

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Ze-Bin Guo

2013-08-01

Full Text Available This study was conducted to investigate the effect of Nelumbinis Plumula total alkaloid (NPA and its main alkaloid components on oxidative stress induced by tert-butyl hydroperoxide (t-BHP in the human hepatocellular HepG2 cell line. According to HPLC analysis, several major alkaloid compounds such as liensinine, isoliensinine and neferine were present in NPA. The cytotoxic effects in 0.55 mM t-BHP-induced HepG2 cells were significantly inhibited by NPA and the major compound in NPA, neferine, showed the strongest activities. The protective effect of neferine against oxidative stress induced by t-BHP may be associated with decreased ROS formation, TBARS generation, LDH release and increased GSH levels, suggesting their involvement of the cytoprotective on oxidative stress. The effects were comparable with quercetin, which was used as positive control. Overall, total alkaloid and alkaloid compounds from Nelumbinis Plumula displayed a significant cytoprotective effect against oxidative stress. Further study is needed to elucidate the relationship between the chemical structures of the components in NPA and their protective effect on oxidative stress.

Crosslinking and photoreaction of ozone-oxidized calf-lens alpha-crystallin

International Nuclear Information System (INIS)

Fujimori, E.

1982-01-01

Direct-photo-oxidation, singlet oxygen-oxidation, or photosensitized oxidation can modify lens crystallins, causing an increase in blue fluorescence and covalent crosslinking. A relationship between these changes has not been elucidated. We now report results from experiments with ozone oxidation. When calf-lens alpha-crystallin is treated with zone oxidation. When calf-lens alpha-crystallin is treated with ozone, new absorption, fluorescence, and phosphorescence, which are characteristic of the oxidized product of tryptophan (N-formylkynurenine), appear at 320, 435, and 445 nm, respectively. In addition, in this ozonization of alpha-crystallin, its polypeptides are crosslinked by nondisulfide bonds. Irradiation of ozone-treated alpha-crystallin with near-ultraviolet (365 nm) light increases crosslinking and reduces the 320 nm absorbance with a concomitant appearance of a new absorption at about 420 nm. This photoproduct exhibits an intense fluorescence around 450 nm and a weak phosphorescence at 510 nm, with excitation peaks at 400, 415, and 422 nm. These findings are essentially the same as those observed in photo-oxidized alpha-crystallin, suggesting the involvement of the same tryptophan oxidized product in the modification of the lens protein

MRI appearance of stereotactic thalamic lesions in Parkinson's disease

Energy Technology Data Exchange (ETDEWEB)

Terada, Kousaku; Asakura, Tetsuhiko; Kasamo, Shizuya; Kusumoto, Kazuhiro; Niiro, Masaki [Kagoshima Univ. (Japan). Faculty of Medicine; Uetsuhara, Kouichi

1990-04-01

Stereotactic thalamotomy is a useful method of treatment in selected cases of Parkinsonism. Previously, the consequences of these stereotactic lesions have been assessed by means of their postoperative clinical effects and CT appearances. Now, however, MR imaging allows a clearer, three-dimensional demonstration of the lesion than does CT scanning; its appearance can now be correlated with the results obtained by the use of the radiofrequency method and its clinical effects. The authors have performed postoperative MR imaging on 12 patients with a total of 13 thalamotomies. The early postoperative MR appearance of these lesions is composed of two relatively clear and distinct parts. In T{sub 1}-weighted imaging, there is a central hyper-intense core and a low-intensity area surrounding it. In T{sub 2}-weighted imaging, there is a central hypo-intense core and a high-intensity area surrounding it. The late postoperative MR appearance is a low-intensity spot in T{sub 1}-weighted imaging and a high-intensity spot in T{sub 2}-weighted imaging. MR imaging is very useful for the postoperative evaluation of stereotactic thalamotomy in helping to identify the location of and the chronological change in the radiofrequency lesions. (author).

Properties of Copper Doped Neodymium Nickelate Oxide as Cathode Material for Solid Oxide Fuel Cells

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Lee Kyoung-Jin

2016-06-01

Full Text Available Mixed ionic and electronic conducting K2NiF4-type oxide, Nd2Ni1-xCuxO4+δ (x=0~1 powders were synthesized by solid state reaction technique and solid oxide fuel cells consisting of a Nd2Ni1-xCuxO4+δ cathode, a Ni-YSZ anode and ScSZ as an electrolyte were fabricated. The effect of copper substitution for nickel on the electrical and electrochemical properties was examined. Small amount of copper doping (x=0.2 resulted in the increased electrical conductivity and decreased polarization resistance. It appears that this phenomenon was associated with the high mean valence of nickel and copper and the resulting excess oxygen (δ. It was found that power densities of the cell with the Nd2Ni1-xCuxO4+δ (x=0.1 and 0.2 cathode were higher than that of the cell with the Nd2NiO4+δ cathode.

Effects of tillage on the Fe oxides activation in soil

Science.gov (United States)

Chi, Guangyu; Chen, Xin; Shi, Yi; Wang, Jun; Zheng, Taihui

2009-07-01

Since mid-1950s, the wetland ecosystems in Sanjiang Plain of Northeast China have been experiencing greater changes in land use, which had negative effects on the soil environments. This study assessed the effects of soil tillage on the activation of soil Fe in the region. The test ecosystems included natural wetland, paddy field and upland field converted from wetland. Soil samples at the depths of 0-10 cm, 10-20 cm, 20-30 cm, 30-40 cm, 40-60 cm, 60-90 cm and 90-120 cm were collected from each of the ecosystems for the analysis of vertical distribution of soil pH, organic carbon, chelate Fe oxides and Fe(II). The results showed that the conversion of wetland into paddy field and upland field induced a decrease of organic carbon content in 0-10 cm soil layer by 61.8% (P carbon showed that chelate Fe oxides and Fe(II) was correlated positively with soil organic carbon and chelate ratio had a more positive relationship with organic carbon than chelate Fe oxides and Fe(II). The results of chelate Fe oxides, Fe(II) and chelate ratio of Fe suggested that reclamation could prevent the Fe activation and organic matter is credited for having an important influence on the process of Fe activation.

Effect of Graphene Oxide on the Reaction Kinetics of Methyl Methacrylate In Situ Radical Polymerization via the Bulk or Solution Technique

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Ioannis S. Tsagkalias

2017-09-01

Full Text Available The synthesis of nanocomposite materials based on poly(methyl methacrylate and graphene oxide (GO is presented using the in situ polymerization technique, starting from methyl methacrylate, graphite oxide, and an initiator, and carried out either with (solution or without (bulk in the presence of a suitable solvent. Reaction kinetics was followed gravimetrically and the appropriate characterization of the products took place using several experimental techniques. X-ray diffraction (XRD data showed that graphite oxide had been transformed to graphene oxide during polymerization, whereas FTIR spectra revealed no significant interactions between the polymer matrix and GO. It appears that during polymerization, the initiator efficiency was reduced by the presence of GO, resulting in a reduction of the reaction rate and a slight increase in the average molecular weight of the polymer formed, measured by gel permeation chromatography (GPC, along with an increase in the glass transition temperature obtained from differential scanning calorimetry (DSC. The presence of the solvent results in the suppression of the gel-effect in the reaction rate curves, the synthesis of polymers with lower average molecular weights and polydispersities of the Molecular Weight Distribution, and lower glass transition temperatures. Finally, from thermogravimetric analysis (TG, it was verified that the presence of GO slightly enhances the thermal stability of the nano-hybrids formed.

Radiation effects on the electrical properties of hafnium oxide based MOS capacitors.

Energy Technology Data Exchange (ETDEWEB)

Petrosky, J. C. (Air Force Institute of Technology, Wright-Patterson Air Force Base, OH); McClory, J. W. (Air Force Institute of Technology, Wright-Patterson Air Force Base, OH); Bielejec, Edward Salvador; Foster, J. C. (Air Force Institute of Technology, Wright-Patterson Air Force Base, OH)

2010-10-01

Hafnium oxide-based MOS capacitors were investigated to determine electrical property response to radiation environments. In situ capacitance versus voltage measurements were analyzed to identify voltage shifting as a result of changes to trapped charge with increasing dose of gamma, neutron, and ion radiation. In situ measurements required investigation and optimization of capacitor fabrication to include dicing, cleaning, metalization, packaging, and wire bonding. A top metal contact of 200 angstroms of titanium followed by 2800 angstroms of gold allowed for repeatable wire bonding and proper electrical response. Gamma and ion irradiations of atomic layer deposited hafnium oxide on silicon devices both resulted in a midgap voltage shift of no more than 0.2 V toward less positive voltages. This shift indicates recombination of radiation induced positive charge with negative trapped charge in the bulk oxide. Silicon ion irradiation caused interface effects in addition to oxide trap effects that resulted in a flatband voltage shift of approximately 0.6 V also toward less positive voltages. Additionally, no bias dependent voltage shifts with gamma irradiation and strong oxide capacitance room temperature annealing after ion irradiation was observed. These characteristics, in addition to the small voltage shifts observed, demonstrate the radiation hardness of hafnium oxide and its applicability for use in space systems.

The anti-aging and anti-oxidation effects of tea water extract in Caenorhabditis elegans.

Science.gov (United States)

Fei, Tianyi; Fei, Jian; Huang, Fang; Xie, Tianpei; Xu, Jifeng; Zhou, Yi; Yang, Ping

2017-10-15

Tea includes puer tea, black tea, green tea and many others. By using model organism Caenorhabditis elegans, the anti-aging and anti-oxidation effects of tea water extract were systemically examined in this study. We found that water extract of puer tea, black tea and green tea all increased the lifespan of worms, postponed Aβ-induced progressive paralysis in Alzheimer's disease transgenic worms, and improved the tolerance of worms to the oxidative stress induced by heavy metal Cr 6+ . Moreover, the anti-oxidation effects of tea water extract at low concentration were different among 4 kinds of brands of green tea. The underlying mechanisms were further explored using genetically manipulated-mutant worms. The anti-oxidative stress effects of green tea water extract depend on the dietary restriction and germline signaling pathways, but not the FOXO and mitochondrial respiratory chain signals. Therefore, tea water extract provides benefits of anti-aging, anti-AD and anti-oxidation. Copyright © 2017. Published by Elsevier Inc.

Curvature effect on nuclear 'pasta': Is it helpful for gyroid appearance?

International Nuclear Information System (INIS)

Nakazato, Ken'ichiro; Iida, Kei; Oyamatsu, Kazuhiro

2011-01-01

In supernova cores and neutron star crusts, nuclei are thought to deform to rodlike and slablike shapes, which are often called nuclear pasta. We study the equilibrium properties of the nuclear pasta by using a liquid-drop model with curvature corrections. It is confirmed that the curvature effect acts to lower the transition densities between different shapes. We also examine the gyroid structure, which was recently suggested as a different type of nuclear pasta by analogy with the polymer systems. The gyroid structure investigated in this paper is approximately formulated as an extension of the periodic minimal surface whose mean curvature vanishes. In contrast to our expectations, we find, from the present approximate formulation, that the curvature corrections act to slightly disfavor the appearance of the gyroid structure. By comparing the energy corrections in the gyroid phase and the hypothetical phases composed of d-dimensional spheres, where d is a general dimensionality, we show that the gyroid is unlikely to belong to a family of the generalized dimensional spheres.

Reciprocal effects of 5-(tetradecyloxy)-2-furoic acid on fatty acid oxidation.

Science.gov (United States)

Otto, D A; Chatzidakis, C; Kasziba, E; Cook, G A

1985-10-01

Under certain incubation conditions 5-(tetradecyloxy)-2-furoic acid (TOFA) stimulated the oxidation of palmitate by hepatocytes, as observed by others. A decrease in malonyl-CoA concentration accompanied the stimulation of oxidation. Under other conditions, however, TOFA inhibited fatty acid oxidation. The observed effects of TOFA depended on the TOFA and fatty acid concentrations, the cell concentration, the time of TOFA addition relative to the addition of fatty acid, and the nutritional state of the animal (fed or starved). The data indicate that only under limited incubation conditions may TOFA be used as an inhibitor of fatty acid synthesis without inhibition of fatty acid oxidation. When rat liver mitochondria were preincubated with TOFA, ketogenesis from palmitate was slightly inhibited (up to 20%) at TOFA concentrations that were less than that of CoA, but the inhibition became almost complete (up to 90%) when TOFA was greater than or equal to the CoA concentration. TOFA had only slight or no inhibitory effects on the oxidation of palmitoyl-CoA, palmitoyl(-)carnitine, or butyrate. Since TOFA can be converted to TOFyl-CoA, the data suggest that the inhibition of fatty acid oxidation from palmitate results from the decreased availability of CoA for extramitochondrial activation of fatty acids. These data, along with previous data of others, indicate that inhibition of fatty acid oxidation by CoA sequestration is a common mechanism of a group of carboxylic acid inhibitors. A general caution is appropriate with regard to the interpretation of results when using TOFA in studies of fatty acid oxidation.

Effects of N-acetylcysteine on semen parameters and oxidative/antioxidant status.

Science.gov (United States)

Ciftci, Halil; Verit, Ayhan; Savas, Murat; Yeni, Ercan; Erel, Ozcan

2009-07-01

To examine whether a beneficial effect of N-acetylcysteine (NAC) on semen parameters and oxidative/antioxidant status in idiopathic male infertility exists. The production of reactive oxygen species is a normal physiologic event in various organs. However, overproduction of reactive oxygen species can be detrimental to sperm and has been associated with male infertility. Our study included 120 patients who had attended our clinic and were diagnosed with idiopathic infertility according to medical history and physical and seminal examination findings, as initial evaluations. The patients were divided randomly into 2 groups. Those in the study group (60 men) were given NAC (600 mg/d orally) for 3 months; the control group (60 men) received a placebo. The oxidative status was determined by measuring the total antioxidant capacity, total peroxide and oxidative stress index in plasma samples. The sperm parameters were evaluated after NAC treatment and were compared with those in the control group. NAC had significant improving effects on the volume, motility, and viscosity of semen. After NAC treatment, the serum total antioxidant capacity was greater and the total peroxide and oxidative stress index were lower in the NAC-treated group compared with the control group. These beneficial effects resulted from reduced reactive oxygen species in the serum and reduced viscosity of the semen. No significant differences were found in the number or morphology of the sperm between the 2 groups. We believe that NAC could improve some semen parameters and the oxidative/antioxidant status in patients with male infertility.

Effect of hydrothermal treatment of coal on the oxidation susceptibility and electrical resistivity of HTT coke

Energy Technology Data Exchange (ETDEWEB)

Sarkar, N.B.; Sarkar, P.; Choudhury, A. [Central Fuel Research Institute, P.O. FRI, Dhanbad-828108, Jharkhand (India)

2005-02-25

The influence of hydrothermal treatment of coal prior to carbonization, on the oxidation susceptibility of resultant coke/char, calcined at 1350, 1800 and 2200 {sup o}C has been investigated. The non-isothermal thermogravimetric analysis technique has been employed, and parameters such as onset, DTG peak temperatures, and cumulative oxidation loss (wt.%) at different temperatures have been utilized to compare proneness to oxidation with respective untreated samples apart from electrical resistivity. Data suggest that all the cokes/chars samples produced from hydrothermally treated coals are less reactive and more electrically conductive (less resistive) than their respective untreated counterparts. But the extent of improvement of oxidation resistance and electrical conductivity appears to be coal-specific. The kinetic parameters obtained by non-linear regression analysis on multi-curve reveal that the n{sup th} order reaction model (where 'n' was found to vary from 0.9 to 1.3) is the best-fitted model. The higher activation energy values observed for hydrothermally treated coke samples are in agreement with the observation of TG analysis data. Overall results indicate the importance of introducing a hydrothermal treatment step for the improvement of oxidation resistance as well as electrical conductivity of the coke samples.

Effects of viewing a pro-Ana website: An experimental study on body satisfaction, affect, and appearance self-efficacy

NARCIS (Netherlands)

Delforterie, M.J.; Larsen, J.K.; Bardone-Cone, A.M.; Scholte, R.H.J.

2014-01-01

Pro-anorexia websites portray an extreme form of thin-ideal. This between-subjects experiment examined the effects of viewing such a website on body satisfaction, affect, and appearance self-efficacy compared to viewing control websites (fashion, home decoration, automutilation). The sample

Effects of Viewing a Pro-Ana Website: An Experimental Study on Body Satisfaction, Affect, and Appearance Self-Efficacy

NARCIS (Netherlands)

Delforterie, M.J.; Larsen, J.K.; Bardone, A.; Scholte, R.H.J.

2014-01-01

Pro-anorexia websites portray an extreme form of thin-ideal. This between-subjects experiment examined the effects of viewing such a website on body satisfaction, affect, and appearance self-efficacy compared to viewing control websites (fashion, home decoration, automutilation). The sample

Oxidation effect on templating of metal oxide nanoparticles within block copolymers

International Nuclear Information System (INIS)

Akcora, Pinar; Briber, Robert M.; Kofinas, Peter

2009-01-01

Amphiphilic norbornene-b-(norbornene dicarboxylic acid) diblock copolymers with different block ratios were prepared as templates for the incorporation of iron ions using an ion exchange protocol. The disordered arrangement of iron oxide particles within these copolymers was attributed to the oxidation of the iron ions and the strong interactions between iron oxide nanoparticles, particularly at high iron ion concentrations, which was found to affect the self-assembly of the block copolymer morphologies.

Heat-Activated Persulfate Oxidation of Chlorinated Solvents in Sandy Soil

Directory of Open Access Journals (Sweden)

Jialu Liu

2014-01-01

Full Text Available Heat-activated persulfate oxidative treatment of chlorinated organic solvents containing chlorinated ethenes and ethanes in soil was investigated with different persulfate dosages (20 g/L, 40 g/L, and 60 g/L and different temperatures (30°C, 40°C, and 50°C. Chlorinated organic solvents removal was increased as persulfate concentration increase. The persulfate dosage of 20 g/L with the highest OE (oxidant efficiency value was economically suitable for chlorinated organic solvents removal. The increasing temperature contributed to the increasing depletion of chlorinated organic solvents. Chlorinated ethenes were more easily removed than chlorinated ethanes. Moreover, the persulfate depletion followed the pseudo-first-order reaction kinetics (kps=0.0292 [PS]0+0.0008, R2=0.9771. Heat-activated persulfate appeared to be an effective oxidant for treatment of chlorinated hydrocarbons.

Media-portrayed idealized images, body shame, and appearance anxiety.

Science.gov (United States)

Monro, Fiona; Huon, Gail

2005-07-01

This study was designed to determine the effects of media-portrayed idealized images on young women's body shame and appearance anxiety, and to establish whether the effects depend on advertisement type and on participant self-objectification. Participants were 39 female university students. Twenty-four magazine advertisements comprised 12 body-related and 12 non-body-related products, one half of each with, and the other one half without, idealized images. Preexposure and post exposure body shame and appearance anxiety measures were recorded. Appearance anxiety increased after viewing advertisements featuring idealized images. There was also a significant interaction between self-objectification level and idealized body (presence vs. absence). No differences emerged for body-related compared with non-body-related product advertisements. The only result for body shame was a main effect for time. Participants' body shame increased after exposure to idealized images, irrespective of advertisement type. Although our findings reveal that media-portrayed idealized images detrimentally affect the body image of young women, they highlight the individual differences in vulnerability and the different effects for different components of body image. These results are discussed in terms of their implications for the prevention and early intervention of body image and dieting-related disorders. ( Copyright 2005 by Wiley Periodicals, Inc

Effect of curcumin against oxidation of biomolecules by hydroxyl radicals.

Science.gov (United States)

Borra, Sai Krishna; Mahendra, Jaideep; Gurumurthy, Prema; Jayamathi; Iqbal, Shabeer S; Mahendra, Little

2014-10-01

Among various reactive oxygen species, hydroxyl radicals have the strongest chemical activity, which can damage a wide range of essential biomolecules such as lipids, proteins, and DNA. The objective of this study was to investigate the beneficial effects of curcumin on prevention of oxidative damage of biomolecules by hydroxyl radicals generated in in vitro by a Fenton like reaction. We have incubated the serum, plasma and whole blood with H2O2/Cu2+/ Ascorbic acid system for 4 hours at 37 0C and observed the oxidation of biomolecules like albumin, lipids, proteins and DNA. Curcumin at the concentrations of 50,100 and 200 μmoles, prevented the formation of ischemia modified albumin, MDA, protein carbonyls, oxidized DNA and increased the total antioxidant levels and GSH significantly. These observations suggest the hydroxyl radical scavenging potentials of curcumin and protective actions to prevent the oxidation of biomolecules by hydroxyl radicals.

Redox proteomic evaluation of oxidative modification and recovery in a 3D reconstituted human skin tissue model exposed to UVB.

Science.gov (United States)

Dyer, J M; Haines, S R; Thomas, A; Wang, W; Walls, R J; Clerens, S; Harland, D P

2017-04-01

Exposure to UV in humans resulting in sunburn triggers a complex series of events that are a mix of immediate and delayed damage mediation and healing. While studies on the effects of UV exposure on DNA damage and repair have been reported, changes in the oxidative modification of skin proteins are poorly understood at the molecular level, despite the important role played by structural proteins in skin tissue, and the effect of the integrity of these proteins on skin appearance and health. Proteomic molecular mapping of oxidation was here applied to try to enhance understanding of skin damage and recovery from oxidative damage and UVB exposure. A redox proteomic-based approach was applied to evaluating skin protein modification when exposed to varying doses of UVB after initial oxidative stress, via tracking changes in protein oxidation during the healing process in vitro using a full-thickness reconstituted human skin tissue model. Bioassays and structural evaluation confirmed that our cultured skin tissues underwent a normal physiological response to UVB exposure. A set of potential skin marker peptides was generated, for use in tracking skin protein oxidative modification. Exposure to UVB after thermal oxidative stress was found to result in higher levels of skin protein oxidation than a non-irradiated control for up to seven days after exposure. Recovery of the skin proteins from oxidative stress, as assessed by the overall protein oxidation levels, was found to be impaired by UVB exposure. Oxidative modification was largely observed in skin structural proteins. Exposure of skin proteins to UVB exacerbates oxidative damage to structural skin proteins, with higher exposure levels leading to increasingly impaired recovery from this damage. This has potential implications for the functional performance of the proteins and inter-related skin health and cosmetic appearance. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Comparative effects of macro-sized aluminum oxide and aluminum oxide nanoparticles on erythrocyte hemolysis: influence of cell source, temperature, and size

Energy Technology Data Exchange (ETDEWEB)

Vinardell, M. P., E-mail: mpvinardellmh@ub.edu; Sordé, A. [Universitat de Barcelona, Departament de Fisiologia, Facultat de Farmàcia (Spain); Díaz, J. [Universitat de Barcelona CCiT, Scientific and Technological Centers (Spain); Baccarin, T.; Mitjans, M. [Universitat de Barcelona, Departament de Fisiologia, Facultat de Farmàcia (Spain)

2015-02-15

Al{sub 2}O{sub 3} is the most abundantly produced nanomaterial and has been used in diverse fields, including the medical, military, and industrial sectors. As there are concerns about the health effects of nanoparticles, it is important to understand how they interact with cells, and specifically with red blood cells. The hemolysis induced by three commercial nano-sized aluminum oxide particles (nanopowder 13 nm, nanopowder <50 nm, and nanowire 2–6 × 200–400 nm) was compared to aluminum oxide and has been studied on erythrocytes from humans, rats, and rabbits, in order to elucidate the mechanism of action and the influence of size and shape on hemolytic behavior. The concentrations inducing 50 % hemolysis (HC{sub 50}) were calculated for each compound studied. The most hemolytic aluminum oxide particles were of nanopowder 13, followed by nanowire and nanopowder 50. The addition of albumin to PBS induced a protective effect on hemolysis in all the nano-forms of Al{sub 2}O{sub 3}, but not on Al{sub 2}O{sub 3}. The drop in HC{sub 50} correlated to a decrease in nanomaterial size, which was induced by a reduction of aggregation. Aluminum oxide nanoparticles are less hemolytic than other oxide nanoparticles and behave differently depending on the size and shape of the nanoparticles. The hemolytic behavior of aluminum oxide nanoparticles differs from that of aluminum oxide.

HDL enhances oxidation of LDL in vitro in both men and women

Directory of Open Access Journals (Sweden)

Lehtimäki T

2005-10-01

Full Text Available Abstract Background Oxidative modification of low-density lipoprotein (LDL is a key event in the oxidation hypothesis of atherogenesis. Some in vitro experiments have previously suggested that high-density lipoprotein (HDL co-incubated with LDL prevents Cu2+-induced oxidation of LDL, while some other studies have observed an opposite effect. To comprehensively clarify the role of HDL in this context, we isolated LDL, HDL2 and HDL3 from sera of 61 free-living individuals (33 women and 28 men. Results When the isolated LDL was subjected to Cu2+-induced oxidation, both HDL2 and HDL3 particles increased the rate of appearance and the final concentration of conjugated dienes similarly in both genders. Oxidation rate was positively associated with polyunsaturated fatty acid content of the lipoproteins in that it was positively related to the content of linoleate and negatively related to oleate. More saturated fats thus protected the lipoproteins from damage. Conclusion We conclude that in vitro HDL does not protect LDL from oxidation, but is in fact oxidized fastest of all lipoproteins due to its fatty acid composition, which is oxidation promoting.

Large fractions of CO2-fixing microorganisms in pristine limestone aquifers appear to be involved in the oxidation of reduced sulfur and nitrogen compounds

Science.gov (United States)

Herrmann, Martina; Rusznyák, Anna; Akob, Denise M.; Schulze, Isabel; Opitz, Sebastian; Totsche, Kai Uwe; Küsel, Kirsten

2015-01-01

The traditional view of the dependency of subsurface environments on surface-derived allochthonous carbon inputs is challenged by increasing evidence for the role of lithoautotrophy in aquifer carbon flow. We linked information on autotrophy (Calvin-Benson-Bassham cycle) with that from total microbial community analysis in groundwater at two superimposed—upper and lower—limestone groundwater reservoirs (aquifers). Quantitative PCR revealed that up to 17% of the microbial population had the genetic potential to fix CO2 via the Calvin cycle, with abundances of cbbM and cbbL genes, encoding RubisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) forms I and II, ranging from 1.14 × 103 to 6 × 106 genes liter−1 over a 2-year period. The structure of the active microbial communities based on 16S rRNA transcripts differed between the two aquifers, with a larger fraction of heterotrophic, facultative anaerobic, soil-related groups in the oxygen-deficient upper aquifer. Most identified CO2-assimilating phylogenetic groups appeared to be involved in the oxidation of sulfur or nitrogen compounds and harbored both RubisCO forms I and II, allowing efficient CO2 fixation in environments with strong oxygen and CO2 fluctuations. The genera Sulfuricellaand Nitrosomonas were represented by read fractions of up to 78 and 33%, respectively, within the cbbM and cbbL transcript pool and accounted for 5.6 and 3.8% of 16S rRNA sequence reads, respectively, in the lower aquifer. Our results indicate that a large fraction of bacteria in pristine limestone aquifers has the genetic potential for autotrophic CO2 fixation, with energy most likely provided by the oxidation of reduced sulfur and nitrogen compounds.

Fabrication and characterization on reduced graphene oxide field effect transistor (RGOFET) based biosensor

Energy Technology Data Exchange (ETDEWEB)

Rashid, A. Diyana [School of Microelectronic Engineering, Universiti Malaysia Perlis (UniMAP), Pauh, Perlis (Malaysia); Ruslinda, A. Rahim, E-mail: ruslinda@unimap.edu.my; Fatin, M. F. [Institute of Nano Electronic Engineering, Universiti Malaysia Perlis (UniMAP), 01000 Kangar, Perlis (Malaysia); Hashim, U.; Arshad, M. K. [School of Microelectronic Engineering, Universiti Malaysia Perlis (UniMAP), Pauh, Perlis (Malaysia); Institute of Nano Electronic Engineering, Universiti Malaysia Perlis (UniMAP), 01000 Kangar, Perlis (Malaysia)

2016-07-06

The fabrication and characterization on reduced graphene oxide field effect transistor (RGO-FET) were demonstrated using a spray deposition method for biological sensing device purpose. A spray method is a fast, low-cost and simple technique to deposit graphene and the most promising technology due to ideal coating on variety of substrates and high production speed. The fabrication method was demonstrated for developing a label free aptamer reduced graphene oxide field effect transistor biosensor. Reduced graphene oxide (RGO) was obtained by heating on hot plate fixed at various temperatures of 100, 200 and 300°C, respectively. The surface morphology of RGO were examined via atomic force microscopy to observed the temperature effect of produced RGO. The electrical measurement verify the performance of electrical conducting RGO-FET at temperature 300°C is better as compared to other temperature due to the removal of oxygen groups in GO. Thus, reduced graphene oxide was a promising material for biosensor application.

in vivo EFFECTS OF RARE-EARTH BASED NANOPARTICLES ON OXIDATIVE BALANCE IN RATS

Directory of Open Access Journals (Sweden)

V. K. Klochkov

2016-12-01

Full Text Available The purpose of the research was to find the influence of rare-earth based nanoparticles (CeO2, GdVO2: Eu3+ on the oxidative balance in rats. We analyzed biochemical markers of oxidative stress (lipid peroxidation level, nitric oxide metabolites, sulfhydryl groups content and enzyme activities (superoxide dismutase, catalase in tissues of rats. It has been found that administration of both types of the nanoparticles increased nitric oxide metabolites and products of lipid peroxidation in liver and spleen within 5 days. At injections of GdVO2: Eu3+ lipid peroxidation products, nitric oxide metabolites in serum at 5, 10 and 15 days of the experiment was also increased whereas the level of sulfhydryl groups decreased compared to the intact state and the control. In contrast, under the influence of nanoparticle CeO2 level diene conjugates were not significantly changed and the level of nitric oxide metabolites within 15 day even decreased. During this period, under the influence of both types of nanoparticles the activity of superoxide dismutase was increased, catalase activity was not changed. Oxidative stress coefficient showed the less pronounced CeO2 prooxidant effect (2.04 in comparison to GdVO2: Eu3+ (6.89. However, after-effect of both types of nanoparticles showed complete restoration of oxidative balance values.

Effect of thermal treatment conditions on properties of vanadium molybdenum oxide catalyst in acrolein oxidation reaction to acrylic acid

International Nuclear Information System (INIS)

Gorshkova, T.P.; Tarasova, D.V.; Olen'kova, I.P.; Andrushkevich, T.V.; Nikoro, T.A.

1984-01-01

The effect of thermal treatment conditions (temperature and gas medium) on properties of vanadium molybdenum oxide catalyst in acrolein oxidation reaction to acrylic acid is investigated. It is shown that active and selective catalysts are formed in the course of thermal decomposition of the drying product of ammonium metavanadate and paramolybdate under the conditions ensuring the vanadium ion reduction up to tetravalent state with conservation of molybdenum oxidation degree equal to 6. It is possible to realize it either by treatment of the catalyst calcinated in the air flow at 300 deg by the reaction mixture at the activation stage or by gas-reducer flow treatment at 280 deg. Thermal treatment in the reducing medium of the oxidized catalyst does not lead to complete regeneration of its properties

Wine and oxidative stress: up-to-date evidence of the effects of moderate wine consumption on oxidative damage in humans.

Science.gov (United States)

Covas, María Isabel; Gambert, Philippe; Fitó, Montserrat; de la Torre, Rafael

2010-02-01

Wine and alcohol consumption has been considered to be protective against coronary heart disease development, an oxidative stress associated disease. Wine contains polyphenols displaying antioxidant properties tested in in vitro and in vivo studies. Due to this, a general consensus exists, both among the general public and the scientific community, that wine, particularly red wine, is an antioxidant beverage. Alcohol consumption, however, is associated with oxidative damage. Several studies have been carried out on the antioxidant health benefits of wine and wine polyphenols. However, adequate scientific evidence (Level I or II) is required to be provided before recommendations or statements which can reach the general public can be formulated. Here, we summarize the state of the art of the up-to-date body of knowledge, and the extent to which there exists evidence of the benefits of moderate wine consumption on oxidative damage in humans. From the available data, there is no evidence, at present, that sustained wine consumption provides antioxidant benefits in healthy volunteers other than to counteract a possible pro-oxidative effect of the alcohol. On the contrary, data on the antioxidant protective effect of red wine in oxidative stress situations are promising. In this way, the postprandial oxidative stress after a meal, despite the diversity of biomarkers used for its evaluation, is counteracted by the ingestion of wine. Further studies are warranted. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

Effects of ethanol extract of Bersama engleriana leaves on oxidative ...

African Journals Online (AJOL)

Pesticides are used to improve agricultural yields; meanwhile they have detrimental effects on human and animal reproduction. This study aimed at evaluating the protective effects of ethanol extract of Bersama engleriana leaves against cypermethrin-induced oxidative stress and reproductive toxicity. Fifty male guinea.

National Needs for Appearance Metrology

Science.gov (United States)

Nadal, Maria E.

2003-04-01

Appearance greatly influences a customer's judgement of the quality and acceptability of manufactured products, as yearly there is approximately $700 billion worth of shipped goods for which overall appearance is critical to their sale. For example, appearance is reported to be a major factor in about half of automobile purchases. The appearance of an object is the result of a complex interaction of the light field incident upon the object, the scattering and absorption properties of the object, and human perception. The measurable attributes of appearance are divided into color (hue, saturation, and lightness) and geometry (gloss, haze). The nature of the global economy has increased international competition and the need to improve the quality of many manufactured products. Since the manufacturing and marketing of these products is international in scope, the lack of national appearance standard artifacts and measurement protocols results in a direct loss to the supplier. One of the primary missions of the National Institute of Standards and Technology (NIST) is to strengthen the U.S. economy by working with industry to develop and apply technology, measurements and standards. The NIST Physics Laboratory has established an appearance metrology laboratory. This new laboratory provides calibration services for 0^o/45^o color standards and 20^o°, 60^o°, and 85^o° specular gloss, and research in the colorimetric characterization of gonioapparent including a new Standard Reference Material for metallic coatings (SRM 2017) and measurement protocols for pearlescent coatings. These services are NIST's first appearance metrology efforts in many years; a response to needs articulated by industry. These services are designed to meet demands for improved measurements and standards to enhance the acceptability of final products since appearance often plays a major role in their acceptability.

Effect of morphology and solvent on two-photon absorption of nano zinc oxide

Energy Technology Data Exchange (ETDEWEB)

Kavitha, M.K. [Department of Chemistry, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram 695547, Kerala (India); Haripadmam, P.C.; Gopinath, Pramod; Krishnan, Bindu [Department of Physics, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram 695547, Kerala (India); John, Honey, E-mail: honey@iist.ac.in [Department of Chemistry, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram 695547, Kerala (India)

2013-05-15

Highlights: ► ZnO nanospheres and triangular structures synthesis by novel precipitation technique. ► The effect of precursor concentration on the size and shape of nano ZnO. ► Open aperture Z-scan measurements of the ZnO nanoparticle dispersions. ► Nanospheres exhibit higher two photon absorption coefficient than triangular nanostructures. ► Nanospheres dispersed in water exhibit higher two photon absorption coefficient than its dispersion in 2-propanol. - Abstract: In this paper, we report the effect of morphology and solvent on the two-photon absorption of nano zinc oxide. Zinc oxide nanoparticles in two different morphologies like nanospheres and triangular nanostructures are synthesized by novel precipitation technique and their two-photon absorption coefficient is measured using open aperture Z-scan technique. Experimental results show that the zinc oxide nanospheres exhibit higher two-photon absorption coefficient than the zinc oxide triangular nanostructures. The zinc oxide nanospheres dispersed in water exhibit higher two-photon absorption coefficient than that of its dispersion in 2-propanol. The zinc oxide nanospheres dispersed in water shows a decrease in two-photon absorption coefficient with an increase in on-axis irradiance. The result confirms the dependence of shape and solvent on the two-photon absorption of nano zinc oxide.

Interpretation of appearance: the effect of facial features on first impressions and personality

DEFF Research Database (Denmark)

Wolffhechel, Karin Marie Brandt; Fagertun, Jens; Jacobsen, Ulrik Plesner

2014-01-01

Appearance is known to influence social interactions, which in turn could potentially influence personality development. In this study we focus on discovering the relationship between self-reported personality traits, first impressions and facial characteristics. The results reveal that several...... personality traits can be read above chance from a face, and that facial features influence first impressions. Despite the former, our prediction model fails to reliably infer personality traits from either facial features or first impressions. First impressions, however, could be inferred more reliably from...... facial features. We have generated artificial, extreme faces visualising the characteristics having an effect on first impressions for several traits. Conclusively, we find a relationship between first impressions, some personality traits and facial features and consolidate that people on average assess...

Antioxidant effects of 14 Chinese traditional medicinal herbs against human low-density lipoprotein oxidation

Directory of Open Access Journals (Sweden)

Hsin-Hung Lin

2015-01-01

Full Text Available The relationship between the antioxidant activities and inhibitory effect of 14 Chinese medicinal herbs against oxidized low-density lipoprotein (LDL formation was evaluated. Prolongation of the lag phase of LDL oxidation depended on the concentration of the herbs. The concentration of each herb that was able to prolong the lag time by about two-fold was calculated and expressed as doubling-time concentration. The lower the doubling-time concentration, the stronger the inhibitory effect exhibited toward LDL oxidation. Among them, Chrysanthemi Flos (Chrysanthemum morifolium ramat; 甘菊花 gān jú huā, Crataegi Fructus (Crataegus pinnatifida Bge. var. major N.E.Br.; 山楂 shān zhā, and Roselle (Hibiscus sabdariffa Linn.; 洛神 luò shén showed significant inhibitory effects. Correlation coefficients between doubling-time concentration and radical-scavenging activities were high; the total phenolic content was also high. In conclusion, phenolic compounds contributed not only to antioxidant activities, but also to the inhibitory effect against LDL oxidation. Chrysanthemi Flos, Crataegi Fructus, and H. sabdariffa, with lower doubling-time concentrations, could be potent phytochemical agents to reduce LDL oxidation and prevent the progression of atherosclerosis.

On the mechanism of cytogenetic effect of electromagnetic radiation: role of oxidation homeostasis

International Nuclear Information System (INIS)

Brezitskaya, N.V.; Timchenko, O.I.

2000-01-01

The evaluation of the role of changes in oxidation homeostasis in developing the cytogenetic effects arising by the electromagnetic irradiation impact is carried out. The experiments were performed on white male rats. The animals were subjected to impact of the nonionizing radiations in the microwave range during 40 days by 7 hours a day. It is established that changes in the free-radical oxidation by the impact of nonionizing radiation of the electromagnetic fields have a wave-like character. It is established that changes in the oxidation homeostasis proceed the development of cytogenetic effects and may be the cause thereof [ru

Synergistic effect of aluminum and ionizing radiation upon ultrastructure, oxidative stress and apoptotic alterations in Paneth cells of rat intestine.

Science.gov (United States)

Eltahawy, N A; Elsonbaty, S M; Abunour, S; Zahran, W E

2017-03-01

Environmental and occupational exposure to aluminum along with ionizing radiation results in serious health problems. This study was planned to investigate the impact of oxidative stress provoked by exposure to ionizing radiation with aluminum administration upon cellular ultra structure and apoptotic changes in Paneth cells of rat small intestine . Animals received daily aluminum chloride by gastric gavage at a dose 0.5 mg/Kg BW for 4 weeks. Whole body gamma irradiation was applied at a dose 2 Gy/week up to 8 Gy. Ileum malondialdehyde, advanced oxidative protein products, protein carbonyl and tumor necrosis factor-alpha were assessed as biomarkers of lipid peroxidation, protein oxidation and inflammation respectively along with superoxide dismutase, catalase, and glutathione peroxidase activities as enzymatic antioxidants. Moreover, analyses of cell cycle division and apoptotic changes were evaluated by flow cytometry. Intestinal cellular ultra structure was investigated using transmission electron microscope.Oxidative and inflammatory stresses assessment in the ileum of rats revealed that aluminum and ionizing radiation exposures exhibited a significant effect upon the increase in oxidative stress biomarkers along with the inflammatory marker tumor necrosis factor-α accompanied by a significant decreases in the antioxidant enzyme activities. Flow cytometric analyses showed significant alterations in the percentage of cells during cell cycle division phases along with significant increase in apoptotic cells. Ultra structurally, intestinal cellular alterations with marked injury in Paneth cells at the sites of bacterial translocation in the crypt of lumens were recorded. The results of this study have clearly showed that aluminum and ionizing radiation exposures induced apoptosis with oxidative and inflammatory disturbance in the Paneth cells of rat intestine, which appeared to play a major role in the pathogenesis of cellular damage. Furthermore, the

Influence of water on the anodic oxidation mechanism of ...

African Journals Online (AJOL)

Diethylenetriamine was oxidised in different electrolytes on platinum electrode. In non-aqueous electrolyte, an irreversible oxidation peak characteristic of DETA oxidation appears on the voltammogram followed by a constant current until the higher limit of the sweeping potential domain is attained. The following successive ...

Effect of ozone oxidative preconditioning in preventing early radiation-induced lung injury in rats

Energy Technology Data Exchange (ETDEWEB)

Bakkal, B.H. [Department of Radiation Oncology, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey); Gultekin, F.A. [Department of General Surgery, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey); Guven, B. [Department of Biochemistry, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey); Turkcu, U.O. [Mugla School of Health Sciences, Mugla Sitki Kocman University, Mugla (Turkey); Bektas, S. [Department of Pathology, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey); Can, M. [Department of Biochemistry, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey)

2013-09-27

Ionizing radiation causes its biological effects mainly through oxidative damage induced by reactive oxygen species. Previous studies showed that ozone oxidative preconditioning attenuated pathophysiological events mediated by reactive oxygen species. As inhalation of ozone induces lung injury, the aim of this study was to examine whether ozone oxidative preconditioning potentiates or attenuates the effects of irradiation on the lung. Rats were subjected to total body irradiation, with or without treatment with ozone oxidative preconditioning (0.72 mg/kg). Serum proinflammatory cytokine levels, oxidative damage markers, and histopathological analysis were compared at 6 and 72 h after total body irradiation. Irradiation significantly increased lung malondialdehyde levels as an end-product of lipoperoxidation. Irradiation also significantly decreased lung superoxide dismutase activity, which is an indicator of the generation of oxidative stress and an early protective response to oxidative damage. Ozone oxidative preconditioning plus irradiation significantly decreased malondialdehyde levels and increased the activity of superoxide dismutase, which might indicate protection of the lung from radiation-induced lung injury. Serum tumor necrosis factor alpha and interleukin-1 beta levels, which increased significantly following total body irradiation, were decreased with ozone oxidative preconditioning. Moreover, ozone oxidative preconditioning was able to ameliorate radiation-induced lung injury assessed by histopathological evaluation. In conclusion, ozone oxidative preconditioning, repeated low-dose intraperitoneal administration of ozone, did not exacerbate radiation-induced lung injury, and, on the contrary, it provided protection against radiation-induced lung damage.

Effect of ozone oxidative preconditioning in preventing early radiation-induced lung injury in rats

International Nuclear Information System (INIS)

Bakkal, B.H.; Gultekin, F.A.; Guven, B.; Turkcu, U.O.; Bektas, S.; Can, M.

2013-01-01

Ionizing radiation causes its biological effects mainly through oxidative damage induced by reactive oxygen species. Previous studies showed that ozone oxidative preconditioning attenuated pathophysiological events mediated by reactive oxygen species. As inhalation of ozone induces lung injury, the aim of this study was to examine whether ozone oxidative preconditioning potentiates or attenuates the effects of irradiation on the lung. Rats were subjected to total body irradiation, with or without treatment with ozone oxidative preconditioning (0.72 mg/kg). Serum proinflammatory cytokine levels, oxidative damage markers, and histopathological analysis were compared at 6 and 72 h after total body irradiation. Irradiation significantly increased lung malondialdehyde levels as an end-product of lipoperoxidation. Irradiation also significantly decreased lung superoxide dismutase activity, which is an indicator of the generation of oxidative stress and an early protective response to oxidative damage. Ozone oxidative preconditioning plus irradiation significantly decreased malondialdehyde levels and increased the activity of superoxide dismutase, which might indicate protection of the lung from radiation-induced lung injury. Serum tumor necrosis factor alpha and interleukin-1 beta levels, which increased significantly following total body irradiation, were decreased with ozone oxidative preconditioning. Moreover, ozone oxidative preconditioning was able to ameliorate radiation-induced lung injury assessed by histopathological evaluation. In conclusion, ozone oxidative preconditioning, repeated low-dose intraperitoneal administration of ozone, did not exacerbate radiation-induced lung injury, and, on the contrary, it provided protection against radiation-induced lung damage

Investigations on MGy ionizing dose effects in thin oxides of micro-electronic devices

Energy Technology Data Exchange (ETDEWEB)

Gaillardin, M.; Paillet, P.; Raine, M.; Martinez, M.; Marcandella, C.; Duhamel, O.; Richard, N.; Leray, J.L. [CEA, DAM, DIF, F-91297 Arpajon (France); Goiffon, V.; Corbiere, F.; Rolando, S.; Molina, R.; Magnan, P. [ISAE, Universite de Toulouse, 10 avenue Edouard Belin, BP 54032, 31055 Toulouse Cedex 4 (France); Girard, S.; Ouerdane, Y.; Boukenter, A. [Universite de Saint-Etienne, Laboratoire H. Curien, UMR-5516, 42000, Saint-Etienne (France)

2015-07-01

Total ionizing dose (TID) effects have been studied for a long time in micro-electronic components designed to operate in natural and artificial environments. In most cases, TID induces both charge trapping in the bulk of irradiated oxides and the buildup of interface traps located at semiconductor/dielectric interfaces. Such effects result from basic mechanisms driven by both the shape of the electric field which stands into the oxide and by fabrication process parameters inducing pre-existing traps in the oxide's bulk. From the pioneering studies based on 'thick' oxide technologies to the most recent ones dedicated to innovative technologies, most studies concluded that the impact of total ionizing dose effects reduces with the oxide thinning. This is specifically the case for the gate-oxide of Metal-Oxide-Semiconductor Field Effect Transistors (MOSFET) for which it is generally considered that TID is not a major issue anymore at kGy dose ranges. TID effects are now mainly due to charge trapping in the field oxides such as Shallow Trench Isolation. This creates either parasitic conduction paths or Radiation-Induced Narrow Channel Effects (RINCE). Static current-voltage (I-V) electrical characteristics are then modified through a significant increase of the off-current of NMOS transistors or by shifting the whole I-V curves (of both NMOS and PMOS transistors). Based on these assumptions, no significant shift of I-V curves should be observed in modern bulk CMOS technologies. However, such phenomenon may not be directly extrapolated to higher TID ranges, typically of several MGy for which only few data are available in the literature. This paper presents evidences of large threshold voltage shifts measured at MGy dose levels despite the fact that transistors are designed in a submicron bulk technology which features a 7-nm thin gate-oxide on GO2 transistors dedicated to mixed analog/digital integrated circuits. Such electrical shifts are encountered

Investigations on MGy ionizing dose effects in thin oxides of micro-electronic devices

International Nuclear Information System (INIS)

Gaillardin, M.; Paillet, P.; Raine, M.; Martinez, M.; Marcandella, C.; Duhamel, O.; Richard, N.; Leray, J.L.; Goiffon, V.; Corbiere, F.; Rolando, S.; Molina, R.; Magnan, P.; Girard, S.; Ouerdane, Y.; Boukenter, A.

2015-01-01

Total ionizing dose (TID) effects have been studied for a long time in micro-electronic components designed to operate in natural and artificial environments. In most cases, TID induces both charge trapping in the bulk of irradiated oxides and the buildup of interface traps located at semiconductor/dielectric interfaces. Such effects result from basic mechanisms driven by both the shape of the electric field which stands into the oxide and by fabrication process parameters inducing pre-existing traps in the oxide's bulk. From the pioneering studies based on 'thick' oxide technologies to the most recent ones dedicated to innovative technologies, most studies concluded that the impact of total ionizing dose effects reduces with the oxide thinning. This is specifically the case for the gate-oxide of Metal-Oxide-Semiconductor Field Effect Transistors (MOSFET) for which it is generally considered that TID is not a major issue anymore at kGy dose ranges. TID effects are now mainly due to charge trapping in the field oxides such as Shallow Trench Isolation. This creates either parasitic conduction paths or Radiation-Induced Narrow Channel Effects (RINCE). Static current-voltage (I-V) electrical characteristics are then modified through a significant increase of the off-current of NMOS transistors or by shifting the whole I-V curves (of both NMOS and PMOS transistors). Based on these assumptions, no significant shift of I-V curves should be observed in modern bulk CMOS technologies. However, such phenomenon may not be directly extrapolated to higher TID ranges, typically of several MGy for which only few data are available in the literature. This paper presents evidences of large threshold voltage shifts measured at MGy dose levels despite the fact that transistors are designed in a submicron bulk technology which features a 7-nm thin gate-oxide on GO2 transistors dedicated to mixed analog/digital integrated circuits. Such electrical shifts are encountered

The effects of radiation on the oxidation of rice bran

International Nuclear Information System (INIS)

Gunawan; Kompiang, S.; Tangenjaya, B.

1988-01-01

The effect of radiation on the oxidation of oil in rice bran during storage was studied. As much as 0.25 kg rice bran (Var. Cisadane) in plastic bag was radiated with 2, 4, 6, and 10 kGy (gamma 60-Co) and storedin room temperature (25 Celcius centigrade) for 8 weeks. Peroxide value was determined biweekly. Although peroxide value was significantl increased, there was no interaction between radiation and storage. Radiation using 10 kGy effected the oxidation, in which the peroxide value was 113.24 mg eq/kg at 8 weeks storage compared to 87.85 mg eq/kg for the unradiated rice bran. (author). 10 refs, 1 fig, 1 tab

[Effect of occupational stress on oxidation/antioxidant capacity in nurses].

Science.gov (United States)

Cao, Lili; Tian, Honger; Zhang, Qingdong; Zhu, Xinyun; Zhan, Yongguo; Su, Jingguo; Xu, Tian; Zhu, Huabin; Liu, Ling

2014-02-01

To investigate the effect of occupational stress on the oxidation/antioxidant capacity in nurses. A total of 131 nurses were included as study subjects. The occupational health information collection system (based on the Internet of things) was used for measurement of occupational stress. Levels of hydroxyl free radicals and antioxidant enzymes were determined. The serum level of superoxide dismutase (SOD) was the highest in nurses under the age of 30 and the lowest in those over 45 (P occupational stress factors for SOD. Job hazards were negative occupational stress factors for POD. Psychological satisfaction was negative occupational stress reaction for hydroxyl free radicals. Calmness was positive occupational stress reaction for SOD, and daily stress was a negative one. The positive occupational stress reactions for GSH-Px were psychological satisfaction and job satisfaction, and daily stress was negative reaction. Nurses with higher occupational stress have stronger oxidation and weaker antioxidant capacity, which intensifies oxidant-antioxidant imbalance and leads to oxidative stress damage.

Magnetron sputtered transparent conductive zinc-oxide stabilized amorphous indium oxide thin films on polyethylene terephthalate substrates at ambient temperature

International Nuclear Information System (INIS)

Yan, Y.; Zhang, X.-F.; Ding, Y.-T.

2013-01-01

Amorphous transparent conducting zinc-oxide stabilized indium oxide thin films, named amorphous indium zinc oxide (a-IZO), were deposited by direct current magnetron sputtering at ambient temperature on flexible polyethylene terephthalate substrates. It has been demonstrated that the electrical resistivity could attain as low as ∼ 5 × 10 −4 Ω cm, which was noticeably lower than amorphous indium tin oxide films prepared at the same condition, while the visible transmittance exceeded 84% with the refractive index of 1.85–2.00. In our experiments, introduction of oxygen gas appeared to be beneficial to the improvement of the transparency and electrical conductivity. Both free carrier absorption and indirect transition were observed and Burstein–Moss effect proved a-IZO to be a degenerated amorphous semiconductor. However, the linear relation between the optical band gap and the band tail width which usually observed in covalent amorphous semiconductor such as a-Si:H was not conserved. Besides, porosity could greatly determine the resistivity and optical constants for the thickness variation at this deposition condition. Furthermore, a broad photoluminescence peak around 510 nm was identified when more than 1.5 sccm oxygen was introduced. - Highlights: ► Highly conducting amorphous zinc-oxide stabilized indium oxide thin films were prepared. ► The films were fabricated on polyethylene terephthalate at ambient temperature. ► Introduction of oxygen can improve the transparency and electrical conductivity. ► The linear relation between optical band gap and band tail width was not conserved

The effects of trace element content on pyrite oxidation rates

Science.gov (United States)

Gregory, D. D.; Lyons, T.; Cliff, J. B.; Perea, D. E.; Johnson, A.; Romaniello, S. J.; Large, R. R.

2017-12-01

Pyrite acts as both an important source and sink for many different metals and metalloids in the environment, including many that are toxic. Oxidation of pyrite can release these elements while at the same time producing significant amounts of sulfuric acid. Such issues are common in the vicinity of abandoned mines and smelters, but, as pyrite is a common accessory mineral in many different lithologies, significant pyrite oxidation can occur whenever pyritic rocks are exposed to oxygenated water or the atmosphere. Accelerated exposure to oxygen can occur during deforestation, fracking for petroleum, and construction projects. Geochemical models for pyrite oxidation can help us develop strategies to mitigate these deleterious effects. An important component of these models is an accurate pyrite oxidation rate; however, current pyrite oxidation rates have been determined using relatively pure pyrite. Natural pyrite is rarely pure and has a wide range of trace element concentrations that may affect the oxidation rate. Furthermore, the position of trace elements within the mineral lattice can also affect the oxidation rate. For example, elements such as Ni and Co, which substitute into the pyrite lattice, are thought to stabilize the lattice and thus prevent pyrite oxidation. Alternatively, trace elements that are held within inclusions of other minerals could form a galvanic cell with the surrounding pyrite, thus enhancing pyrite oxidation rates. In this study, we present preliminary analyses from three different pyrite oxidation experiments each using natural pyrite with different trace element compositions. These results show that the pyrite with the highest trace element concentration has approximately an order of magnitude higher oxidation rate compared to the lowest trace element sample. To further elucidate the mechanisms, we employed microanalytical techniques to investigate how the trace elements are held within the pyrite. LA-ICPMS was used to determine the

A graphene oxide-carbon nanotube grid for high-resolution transmission electron microscopy of nanomaterials

International Nuclear Information System (INIS)

Zhang Lina; Zhang Haoxu; Zhou Ruifeng; Chen Zhuo; Li Qunqing; Fan Shoushan; Jiang Kaili; Ge Guanglu; Liu Renxiao

2011-01-01

A novel grid for use in transmission electron microscopy is developed. The supporting film of the grid is composed of thin graphene oxide films overlying a super-aligned carbon nanotube network. The composite film combines the advantages of graphene oxide and carbon nanotube networks and has the following properties: it is ultra-thin, it has a large flat and smooth effective supporting area with a homogeneous amorphous appearance, high stability, and good conductivity. The graphene oxide-carbon nanotube grid has a distinct advantage when characterizing the fine structure of a mass of nanomaterials over conventional amorphous carbon grids. Clear high-resolution transmission electron microscopy images of various nanomaterials are obtained easily using the new grids.

Neuroprotective effect of a new variant of Epo nonhematopoietic against oxidative stress

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C. Castillo

2018-04-01

Full Text Available Human erythropoietin is mainly recognized for its hematopoietic function; however, by binding to its receptor (EpoR, it can activate different signaling pathways as STAT, PI3K, MAPK and RAS to increase cellular differentiation or provide neuroprotective effects, among others. A recombinant human erythropoietin variant with low glycosylation and without hematopoietic effect (EpoL was purified from skimmed goat milk. Recombinant human erythropoietin (Epo was obtained from CHO cell line and used as control to compare EpoL effects. Neuroprotection studies were performed in PC12 cells and rat hippocampal slices. Cells were pretreated during 1 h with EpoL or Epo and exposed to oxidative agents (H2O2 or FCCP; cell viability was assayed at the end of the experiment by the MTT method. Hippocampal slices were exposed to 15 min of oxygen and glucose deprivation (OGD and the neuroprotective drugs EpoL or Epo were incubated for 2 h post-OGD in re-oxygenated medium. Cell cultures stressed with oxidative agents, and pretreated with EpoL, showed neuroprotective effects of 30% at a concentration 10 times lower than that of Epo. Moreover, similar differences were observed in OGD ex vivo assays. Neuroprotection elicited by EpoL was lost when an antibody against EpoR was present, indicating that its effect is EpoR-dependent. In conclusion, our results suggest that EpoL has a more potent neuroprotective profile than Epo against oxidative stress, mediated by activation of EpoR, thus EpoL represents an important target to develop a potential biopharmaceutical to treat different central nervous system pathologies related to oxidative stress such as stroke or neurodegenerative diseases. Keywords: Erythropoietin, Erythropoietin receptor, Neuroprotection, Oxidative stress

Photoelectron binding energy shifts observed during oxidation of group IIA, IIIA and IVA elemental surfaces

International Nuclear Information System (INIS)

Heide, P.A.W. van der

2006-01-01

An extensive re-evaluation of XPS binding energies (BE's) and binding energy shifts (ΔBE's) from metals, oxides and the carbonates of the group II, III and IVA elements (exceptions are Be, Mg and Hf) has been carried out using a substrate specific BE referencing approach. From this, O-1s BE's are found to fall into surface oxide, bulk oxide and carbonate groupings, with bulk oxides showing the lowest BE's followed by surface oxides (+∼1.5 eV) and then carbonates (+∼3.0 eV). The O-1s BE's from the bulk oxides also appear to scale with 1/d, where d is inter-atomic distance. The same is noted in the ΔBE's observed from the metallic counterparts during oxidation of the elemental surfaces. This, and the decreasing BE exhibited by Ca, Sr and Ba on oxidation is explained within the charge potential model as resulting from competing inter- and intra-atomic effects, and is shown to be consistent with partial covalency arguments utilizing Madulung potentials. The ΔBE's also fall into groups according to the elements location in the periodic table, i.e. s, p or d block. These trends open up the possibility of approximating ΔBE's arising from initial and final state effects, and bond distances

Effects of creep and oxidation on reduced modulus in high-temperature nanoindentation

International Nuclear Information System (INIS)

Li, Yan; Fang, Xufei; Lu, Siyuan; Yu, Qingmin; Hou, Guohui; Feng, Xue

2016-01-01

Nanoindentation tests were performed on single crystal Ni-based superalloy at temperatures ranging from 20 °C to 800 °C in inert environment. Load-displacement curves at temperatures higher than 500 °C exhibit obvious creep inferred by increasing displacements at load-holding segments. Load-displacement curves obtained at 800 °C also display negative unloading stiffness. Examination of the microstructure beneath the indented area using Transmission Electron Microscope (TEM) reveals abundant dislocation piling up as well as oxide formation on the substrate. A method considering the creep effect is proposed to calculate the reduced modulus. In addition, a dimensionless ratio relating indentation depth and oxide film thickness is introduced to explain the oxidation effect on the mechanical properties derived from the load-displacement curves.

[Flavonoid oxidation kinetics in aqueous and aqueous organic media in the presence of peroxidase, tyrosynase, and hemoglobin].

Science.gov (United States)

Barsukova, M E; Tokareva, A I; Buslova, T S; Malinina, L I; Veselova, I A; Shekhovtsova, T N

2017-01-01

The kinetics of oxidation reactions of flavonoids, quercetin, dihydroquercetin, and epicatechin has been studied in the presence of biocatalysts of different natures: horseradish peroxidase, mushroom tyrosinase, and hemoglobin from bull blood. Comparison of the kinetic parameters of the oxidation reaction showed that peroxidase appeared to be the most effective biocatalyst in these processes. The specificity of the enzyme for quercetin increased with increasing the polarity of the solvent in a series of ethanol–acetonitrile–dimethyl sulfoxide.

Time-dependence hole and electron trapping effects in SIMOX buried oxides

International Nuclear Information System (INIS)

Boesch, H.E. Jr.; Taylor, T.L.; Hite, L.R.; Bailey, W.E.

1990-01-01

Back-channel threshold shift associated with the buried oxide layers of separation by implanted oxygen (SIMOX) and zone-melted recrystallization (ZMR) field-effect transistors (FETs) was measured following pulsed irradiation as a function of temperature and back-gate bias using a fast time-resolved I-V measurement technique. The SIMOX FETs showed large initial negative voltage shifts at 0.2 ms after irradiation followed by temperature- and bias-dependent additional negative shifts to 800s. Analysis and modeling of the results indicate efficient deep trapping of radiation-generated holes in the bulk of the oxide, substantial initial trapping of radiation-generated electrons in the oxide, and rapid removal of the trapped electrons by a thermal detrapping process. The ZMR FETs showed evidence of substantial trapping of holes alone in the oxide bulk

Toxicological effects of graphene oxide on adult zebrafish (Danio rerio)

Energy Technology Data Exchange (ETDEWEB)

Souza, Jaqueline P., E-mail: souza.jaqueline@gmail.com; Baretta, Jéssica F.; Santos, Fabrício; Paino, Ieda M.M.; Zucolotto, Valtencir

2017-05-15

Highlights: • Graphene oxide exposure caused apoptotic and necrotic stages in zebrafish gill cells. • Graphene oxide induced reactive oxygen generation in zebrafish gill cells. • Gill and liver tissues suffered injuries after graphene oxide chronic exposure. • Zebrafish blood cells did not present DNA damages after graphene oxide exposure. - Abstract: Graphene exhibits unique physical and chemical properties that facilitate its application in many fields, including electronics and biomedical areas. However, the use of graphene and its derivatives could result in accumulation in aquatic environments, and the risks posed by these compounds for organisms are not completely understood. In this study, we investigated the effects of graphene oxide (GO) on adult zebrafish (Danio rerio). Experimental fish were exposed to 2, 10 or 20 mg L{sup −1} GO, and the cytotoxicity, genotoxicity and oxidative stress were assessed. The morphology of the gills and liver tissues was also analyzed. Graphene oxide exposure led to an increase in the number of gill cells that were in early apoptotic and necrotic stages, but genotoxicity was not observed in blood cells. We also observed the generation of Reactive Oxygen Species (ROS) in gill cells. Structural analysis revealed injuries to gill tissues, including a dilated marginal channel, lamellar fusion, clubbed tips, swollen mucocytes, epithelial lifting, aneurysms, and necrosis. Liver tissues also presented lesions such as peripherally located nuclei. Furthermore, hepatocytes exhibited a non-uniform shape, picnotic nuclei, vacuole formation, cell rupture, and necrosis. Our results showed that sub-lethal doses of graphene oxide could be harmful to fish species and thus represent risks for the aquatic food chain.

Neuroprotective effect of resveratrol against scopolamine-induced cognitive impairment and oxidative stress in rats

Directory of Open Access Journals (Sweden)

Pushpalatha Bunadri

2013-01-01

Full Text Available The objective of this study was to examine the neuroprotective effect of resveratrol on cognitive impairment induced by scopolamine, a muscarinic antagonist, in rats. Memory impairment was induced by administration of scopolamine (1 mg/kg intraperitoneally. Cognitive functions were assessed using radial arm maze, an active avoidance paradigm. Oxidative stress parameters like malondialdehyde, catalase and superoxide dismutase were assessed and acetylcholinesterase activity was estimated. More working and reference memory errors in the radial arm maze test and fewer avoidances in the active avoidance test were observed with scopolamine in the 1 mg/kg i.p.-treated animals. This phenomenon is a clear indication of memory impairment. Oral administration of resveratrol (20 mg/kg inhibited the occurrence of higher working, reference memory errors and prevented the incidence of less avoidances. Resveratrol appeared to have exerted memory-enhancing effects by inhibiting acetylcholinesterase activity and prevented the rise in malondialdehyde levels and loss of antioxidant enzymes catalase and superoxide dismutase, showing antioxidant potential. Based on the above results of behavioral and biochemical studies, it can be concluded that resveratrol protected against scopolamine-induced loss of cognition. The results also indicate that resveratrol is an antioxidant and an acetylcholinesterase inhibitor, and it is likely that resveratrol’s protective effect is related to its antioxidant and cholinesterase inhibitory effects.

Effects of garlic extract on color, lipid oxidation and oxidative breakdown products in raw ground beef during refrigerated storage

Directory of Open Access Journals (Sweden)

XINZHUANG ZHANG

2016-03-01

Full Text Available The study aims to investigate the effects of garlic extracts on color, lipid oxidation, and oxidative breakdown products in raw ground beef during refrigerated storage. The two treatments were:control group (C, with no addition and experiment group (D, 50 mg garlic extracts added to 100 g beef. Adding garlic extracts significant increased a* value (PA ≤ 0.05, and significant decreased TBARS and PV values (PA ≤ 0.05. The pH and –SH value of D group had a decreasing tendency (PA=0.0522 and an increasing tendency (PA=0.0636 respectively compared to C group. Garlic extracts protected phospholipids, fatty acids and polypeptides from oxidation. The results indicatethat garlic extracts have the antioxidant activity, helping maintain the meat color, inhibiting lipid oxidation and protein degradation of raw ground beef during refrigerated storage.

The effect of water injection on nitric oxide emissions of a gas turbine combustor burning ASTM Jet-A fuel

Science.gov (United States)

Marchionna, N. R.; Diehl, L. A.; Trout, A. M.

1973-01-01

Tests were conducted to determine the effect of water injection on oxides of nitrogen (NOx) emissions of a full annular, ram induction gas turbine combustor burning ASTM Jet-A fuel. The combustor was operated at conditions simulating sea-level takeoff and cruise conditions. Water at ambient temperature was injected into the combustor primary zone at water-fuel ratios up to 2. At an inlet-air temperature of 589 K (600 F) water injection decreased the NOx emission index at a constant exponential rate: NOx = NOx (o) e to the -15 W/F power (where W/F is the water-fuel ratio and NOx(o) indicates the value with no injection). The effect of increasing combustor inlet-air temperature was to decrease the effect of the water injection. Other operating variables such as pressure and reference Mach number did not appear to significantly affect the percent reduction in NOx. Smoke emissions were found to decrease with increasing water injection.

Perform Tests and Document Results and Analysis of Oxide Layer Effects and Comparisons

Energy Technology Data Exchange (ETDEWEB)

Collins, E. D. [ORNL; DelCul, G. D. [ORNL; Spencer, B. B. [ORNL; Hunt, R. D. [ORNL; Ausmus, C. [ORNL

2014-08-30

During the initial feasibility test using actual used nuclear fuel (UNF) cladding in FY 2012, an incubation period of 30–45 minutes was observed in the initial dry chlorination. The cladding hull used in the test had been previously oxidized in a dry air oxidation pretreatment prior to removal of the fuel. The cause of this incubation period was attributed to the resistance to chlorination of an oxide layer imparted by the dry oxidation pretreatment on the cladding. Subsequently in 2013, researchers at the Korea Atomic Energy Institute (KAERI) reported on their chlorination study [R1] on ~9-gram samples of unirradiated ZirloTM cladding tubes that had been previously oxidized in air at 500oC for various time periods to impart oxide layers of varying thickness. In early 2014, discussions with Indefinite Delivery, Indefinite Quantity (IDIQ) contracted technical consultants from Westinghouse described their previous development (and patents) [R2] on methods of chemical washing to remove some or all of the hydrous oxide layer imparted on UNF cladding during irradiation in light water reactors (LWRs) . Thus, the Oak Ridge National Laboratory (ORNL) study, described herein, was planned to extend the KAERI study on the effects of anhydrous oxide layers, but on larger ~100-gram samples of unirradiated zirconium alloy cladding tubes, and to investigate the effects of various methods of chemical pretreatment prior to chlorination with 100% chlorine on the average reaction rates and Cl2 usage efficiencies.

Ovarian metastases: Computed tomographic appearances

International Nuclear Information System (INIS)

Megibow, A.J.; Hulnick, D.H.; Bosniak, M.A.; Balthazar, E.J.

1985-01-01

Computed tomographic scans of 34 patients with ovarian metastases were reviewed to assess the radiographic appearances and to correlate these with the primary neoplasms. Primary neoplasms were located in the colon (20 patients), breast (six), stomach (five), small bowel (one), bladder (one), and Wilms tumor of the kidney (one). The radiographic appearance of the metastatic lesions could be described as predominantly cystic (14 lesions), mixed (12 lesions), or solid (seven lesions). The cystic and mixed lesions tended to be larger in overall diameter than the solid. The metastases from gastric carcinoma appeared solid in four of five cases. The metastases from the other neoplasms had variable appearances simulating primary ovarian carcinoma

Anti-oxidant and anti-inflammatory effects of rice bran and green tea ...

African Journals Online (AJOL)

Purpose: To investigate the anti-inflammatory and anti-oxidant properties of an enzyme bath of Oryza sativa (rice bran) and Camellia sinensis O. Kuntz (green tea) fermented with Bacillus subtilis (OCB). Methods: The anti-oxidant effects of OCB were assessed by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay and flow ...

Nitrous Oxide Anesthesia and Plasma Homocysteine in Adolescents

Science.gov (United States)

Nagele, Peter; Tallchief, Danielle; Blood, Jane; Sharma, Anshuman; Kharasch, Evan D.

2011-01-01

Background Nitrous oxide inactivates vitamin B12, inhibits methionine synthase and consequently increases plasma total homocysteine (tHcy). Prolonged exposure to nitrous oxide can lead to neuropathy, spinal cord degeneration and even death in children. We tested the hypothesis that nitrous oxide anesthesia causes a significant increase in plasma tHcy in children. Methods Twenty-seven children (age 10-18 years) undergoing elective major spine surgery were enrolled and serial plasma samples from 0 – 96 hours after induction were obtained. The anesthetic regimen, including the use of nitrous oxide, was at the discretion of the anesthesiologist. Plasma tHcy was measured using standard enzymatic assays. Results The median baseline plasma tHcy concentration was 5.1 μmol/L (3.9 – 8.0 μmol/L, interquartile range) and increased in all patients exposed to nitrous oxide (n=26) by an average of +9.4 μmol/L (geometric mean; 95% CI 7.1 – 12.5 μmol/L) or +228% (mean; 95% CI 178% - 279%). Plasma tHcy peaked between 6-8 hours after induction of anesthesia. One patient who did not receive nitrous oxide had no increase in plasma tHcy. Several patients experienced a several-fold increase in plasma tHcy (max. +567%). The increase in plasma tHcy was strongly correlated with the duration and average concentration of nitrous oxide anesthesia (r= 0.80; pnitrous oxide anesthesia develop significantly increased plasma tHcy concentrations. The magnitude of this effect appears to be greater compared to adults; however, the clinical relevance is unknown. PMID:21680854

Magnetic resonance imaging appearance of oxidized regenerated cellulose in breast cancer surgery.

Science.gov (United States)

Giuliani, Michela; Rella, Rossella; Fubelli, Rita; Patrolecco, Federica; Di Giovanni, Silvia Eleonora; Buccheri, Chiara; Padovano, Federico; Belli, Paolo; Romani, Maurizio; Rinaldi, Pierluigi; Bufi, Enida; Franceschini, Gianluca; Bonomo, Lorenzo

2016-09-01

To describe magnetic resonance imaging (MRI) findings in patients who underwent breast-conserving surgery followed by oxidized regenerated cellulose (ORC) implantation in surgical cavity. We retrospectively reviewed 51 MRI examinations performed between January 2009 and January 2014 in 51 patients who underwent BCS with ORC implantation. In 29/51 (57 %) cases, MRIs showed abnormal findings with three main MRI patterns: (1) complex masses: hyperintense collections on T2-weighted (w) images with internal round hypointense nodules without contrast enhancement (55 %); (2) completely hyperintense collections (17 %); and (3) completely hypointense lesions (28 %). All lesions showed rim enhancement on T1w images obtained in the late phase of the dynamic study with a type 1 curve. Diffusion-weighted imaging was negative in all MRIs and, in particular, 22/29 (76 %) lesions were hyperintense but showing ADC values >1.4 × 10(-3) mm(2)/s, while the remaining 7/29 (24 %) lesions were hypointense. In four cases, linear non-mass-like enhancement was detected at the periphery of surgical cavity; these patients were addressed to a short-term follow-up, and the subsequent examinations showed the resolution of these findings. When applied to surgical residual cavity, ORC can lead alterations in surgical scar. This could induce radiologists to misinterpret ultrasonographic and mammographic findings, addressing patients to MRI or biopsy; so knowledge of MRI specific features of ORC, it is essential to avoid misdiagnosis of recurrence.

Nitrous Oxide Effects the Uptake of Sevoflurane to the Body During Induction

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Kamil Varlık Erel

2018-04-01

Full Text Available Objective: To determine the effects of nitrous oxide (N2O on the speed and quality of the uptake process of sevoflurane during inhalation induction in adult patients. Materials­ and­ Methods: For randomized controlled study, eighty-four American Society of Anesthesiologists I-II patients undergoing gynecological interventions were randomly assigned to receive an 8% sevoflurane mixture with either 67% N2O plus 33% oxygen [Group sevoflurane and nitrous oxide (SA] or 100% oxygen only [Group sevoflurane (S]. Both groups were induced by a single-breath induction. End-tidal and inspiratory concentrations of respiratory and anesthetic gasses were continuously assessed during induction as well as time to loss of eyelash reflex, time to cessation of eye movements, and time to initiation of spontaneous breaths. Patients were intubated by the 5th minute of induction and their vital signs, bispectral indexes, reflex responses to intubation and additional drug requirements for intubation were also recorded. Results: End-tidal sevoflurane concentrations and the ratio of alveolar to inspiratory sevoflurane concentrations (FA/Fi of patients in group SA recorded at the 2nd, the third and the 5th minute of induction showed statistically significant increases when compared with patients in group S. Time to loss of eyelash reflex and time to cessation of eye movements were found to be decreased in group SA by 25 and 13%, respectively. Patients who presented with a reflex response to intubation in group S exceeded patients in group SA by 38.8% and patients who required additional medication for intubation in group S exceeded patients in group SA by 28.6%. Conclusion: The findings of this study support the view that administration of N2O improves the rate and quality of mask induction with sevoflurane. The benefits provided by N2O attributable to the concentrating and second gas effects appear during the first few minutes of induction (2nd, 3rd, and 4th minutes as

Nanostructured magnesium oxide as cure activator for polychloroprene rubber.

Science.gov (United States)

Kar, Sritama; Bhowmick, Anil K

2009-05-01

The aim of this research was to synthesize magnesium oxide nanoparticles and to use them as cure activator for polychloroprene rubber (CR). The effects of counterions of magnesium salts on the homogeneous phase precipitation reaction to control size, monodispersity, crystallinity, and morphology of Mg(OH)2 nanoparticles were also investigated. Magnesium oxide nanoparticles were synthesized by optimizing the calcination temperature of Mg(OH)2 nanoparticles. Finally, the MgO nanoparticles were dispersed in polychloroprene rubber (CR) solution along with zinc oxide (ZnO) powder. The influence of MgO nanoparticles on the mechanical, dynamic mechanical and thermal properties of the resulting nanocomposites was quantified. The modulus and strength of ZnO-cured polychloroprene rubber with 4% MgO nanoparticles appeared to be superior to those with ZnO particles or ZnO with rubber grade MgO particles. These composites were further characterized by transmission electron microscopy and infrared spectroscopy in order to understand the morphology of the resulting system and the load transfer mechanism.

Effects of Temperature on Aggregation Kinetics of Graphene Oxide in Aqueous Solutions

Science.gov (United States)

Wang, M.; Gao, B.; Tang, D.; Sun, H.; Yin, X.; Yu, C.

2017-12-01

Temperature may play an important role in controlling graphene oxide (GO) stability in aqueous solutions, but it has been overlooked in the literature. In this work, laboratory experiments were conducted to determine the effects of temperature (6, 25, and 40 °C) on GO aggregation kinetics under different combinations of ionic strength, cation type, humic acid (HA) concentration by monitoring GO hydrodynamic radii and attachment efficiencies. The results showed that, without HA, temperature increase promoted GO aggregation in both monovalent (Na+ and K+) and divalent (Ca2+) solutions. This phenomenon might be caused by multiple processes including enhanced collision frequency, enhanced cation dehydration, and reduced electrostatic repulsion. The presence of HA introduced steric repulsion forces that enhanced GO stability and temperature showed different effects GO aggregation kinetics in monovalent and divalent electrolytes. In monovalent electrolytes, cold temperature diminished the steric repulsion of HA-coated GO. As a result, the fastest increasing rate of GO hydrodynamic radius and the smallest critical coagulation concentration value appeared at the lowest temperature (6 °C). Conversely, in divalent electrolyte solutions with HA, high temperate favored GO aggregation, probably because the interactions between Ca2+ and HA increased with temperature resulting in lower HA coating on GO. Findings of this work emphasized the importance of temperature as well as solution chemistry on the stability and fate of GO nanoparticles in aquatic environment.

Modulation of oxidative damage by nitroxide free radicals.

Science.gov (United States)

Dragutan, Ileana; Mehlhorn, Rolf J

2007-03-01

Piperidine nitroxides like 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) are persistent free radicals in non-acidic aqueous solutions and organic solvents that may have value as therapeutic agents in medicine. In biological environments, they undergo mostly reduction to stable hydroxylamines but can also undergo oxidation to reactive oxoammonium compounds. Reactions of the oxoammonium derivatives could have adverse consequences including chemical modification of vital macromolecules and deleterious effects on cell signaling. An examination of their reactivity in aqueous solution has shown that oxoammonium compounds can oxidize almost any organic as well as many inorganic molecules found in biological systems. Many of these reactions appear to be one-electron transfers that reduce the oxoammonium to the corresponding nitroxide species, in contrast to a prevalence of two-electron reductions of oxoammonium in organic solvents. Amino acids, alcohols, aldehydes, phospholipids, hydrogen peroxide, other nitroxides, hydroxylamines, phenols and certain transition metal ions and their complexes are among reductants of oxoammonium, causing conversion of this species to the paramagnetic nitroxide. On the other hand, thiols and oxoammonium yield products that cannot be detected by ESR even under conditions that would oxidize hydroxylamines to nitroxides. These products may include hindered secondary amines, sulfoxamides and sulfonamides. Thiol oxidation products other than disulfides cannot be restored to thiols by common enzymatic reduction pathways. Such products may also play a role in cell signaling events related to oxidative stress. Adverse consequences of the reactions of oxoammonium compounds may partially offset the putative beneficial effects of nitroxides in some therapeutic settings.

Polycrystalline oxides formation during transient oxidation of (001) Cu-Ni binary alloys studied by in situ TEM and XRD

International Nuclear Information System (INIS)

Yang, J.C.; Li, Z.Q.; Sun, L.; Zhou, G.W.; Eastman, J.A.; Fong, D.D.; Fuoss, P.H.; Baldo, P.M.; Rehn, L.E.; Thompson, L.J.

2009-01-01

The nucleation and growth of Cu 2 O and NiO islands due to oxidation of Cu x Ni 1-x (001) films were monitored, at various temperatures, by in situ ultra-high vacuum (UHV) transmission electron microscopy (TEM) and in situ synchrotron X-ray diffraction (XRD). In remarkable contrast to our previous observations of Cu and Cu-Au oxidation, irregular-shaped polycrystalline oxide islands formed with respect to the Cu-Ni alloy film, and an unusual second oxide nucleation stage was noted. In situ XRD experiments revealed that NiO formed first epitaxially, then other orientations appeared, and finally polycrystalline Cu 2 O developed as the oxidation pressure was increased. The segregation of Ni and Cu towards or away, respectively, from the alloy surface during oxidation could disrupt the surface and cause polycrystalline oxide formation.

Protective effect of taurine against potassium bromate-induced hemoglobin oxidation, oxidative stress, and impairment of antioxidant defense system in blood.

Science.gov (United States)

Ahmad, Mir Kaisar; Mahmood, Riaz

2016-03-01

Potassium bromate (KBrO3 ) is widely used as a food-additive and is a major water disinfection by-product. KBrO3 causes severe toxicity in humans and experimental animals. Bromate is considered a probable human carcinogen and a complete carcinogen in animals. We have investigated the potential role of taurine in protecting against KBrO3 -induced oxidative stress in rat blood. Animals were given taurine for 5 days prior to KBrO3 and then sacrificed. Blood was collected and used to prepare hemolysates and plasma, which were then used for the analysis of several biochemical parameters. Administration of single oral dose of KBrO3 alone induced hepato- and nephro-toxicity as evident by elevated marker levels in plasma. Lipid peroxidation and protein oxidation were increased both in plasma and erythrocytes, suggesting the induction of oxidative stress. KBrO3 increased methemoglobin, nitric oxide, and hydrogen peroxide levels. It also altered the activities of the major antioxidant enzymes and lowered the antioxidant power of blood. Administration of taurine, prior to treatment with KBrO3 , resulted in significant attenuation in all these parameters but the administration of taurine alone had no effect. These results show that taurine is effective in mitigating the oxidative insult induced in rat blood by KBrO3 . © 2014 Wiley Periodicals, Inc.

Effect of annealing and oxide layer thickness on doping profiles shape of ''through-oxide'' implanted P+ ions in textured silicon

International Nuclear Information System (INIS)

El-Dessouki, M.S.; Galloni, R.

1987-10-01

Phosphorous ions at energies of 60+100 KeV, and doses (4+5)x10 15 atom/cm 2 have been implanted randomly through SiO 2 layers into textured silicon crystals. The penetration profiles of the P + ions have been determined by means of differential sheet resistivity and Hall-effect, together with the anodic oxidation stripping technique. The effect of the oxide layer thickness, annealing temperature on the junction properties has been studied. The damage produced by implantation, has also been investigated using transmission electron microscope (TEM). From the mobility measurements of the free carriers as a function of depth through the junction, two minima have been observed in through oxide implanted samples. The one nearer to the Si-SiO 2 interface (at about 200A from the interface) was related to the damage produced by the recoil oxygen atoms from the oxide layer into silicon. The deeper minimum is lying at ∼ 0.2μm from the interface and was attributed to the damage produced by the implanted P + ions, which caused clusters and defect loops after annealing. This damage was observed through TEM photographs. The optimum conditions for producing shallow junction without losing much of the implanted P + ions through the oxide layer were estimated. (author). 22 refs, 7 figs, 1 tab

The role of appearance schematicity in the internalization of media appearance ideals: A panel study of preadolescents.

Science.gov (United States)

Rousseau, Ann; Gamble, Hilary; Eggermont, Steven

2017-10-01

Individuals who are more strongly invested in their appearance, appearance schematics, have a tendency to engage in appearance-related comparison. Appearance schematicity consists of two components. The self-evaluative component concerns the degree to which appearance is central to self-worth, referred to as dysfunctional appearance beliefs. Motivational salience refers to the engagement in behaviors designed to enhance appearance, such as body surveillance. Based on a three-wave panel survey of 973 Flemish preadolescents (M age  = 11.15, SD = 1.13) we found that the motivational and self-evaluative components had a different impact on media internalization. For preadolescents who engaged in more body surveillance, watching television resulted in more media internalization. For preadolescents who had fewer dysfunctional appearance beliefs, watching television resulted in more media internalization. These findings suggest that appearance schematicity is an important susceptibility variable in the relationship between TV-exposure and media internalization, and emphasize the importance of investigating individual dispositions beyond gender differences. Copyright © 2017 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Lutein as protective agent against neonatal oxidative stress

Directory of Open Access Journals (Sweden)

Giuseppe Buonocore

2014-06-01

Full Text Available Free radicals (FR are important for a correct development of neonatal organs and tissues. However, newborn and fetus have profoundly impaired antioxidant system. In these subjects, oxidative stress (OS may be detrimental by activating deleterious cellular processes. Decreasing FR and restoring oxidative imbalance certainly appear to be beneficial in perinatal period. Among the therapeutic antioxidant approaches in newborns, lutein, a compound belonging to the xanthophyll family of carotenoids, is one of the emerging strategies. Humans cannot synthesize lutein, hence the intake primarily depends on diet. In the neonatal period, fresh, non-processed human milk is the main dietary source of lutein, while infant formula is lacking it. Lutein has antioxidant and anti-inflammatory properties. Lutein supplementation in human newborns during the first days of life has been demonstrated to decrease plasma biomarkers of OS and increase antioxidant capacities. Numerous experimental study have demonstrated that lutein effectively neutralizes oxidants and modulates inflammatory processes, showing particular protective effects on macula and photoreceptors against phototoxicity and oxidative injury. Only few clinical studies evaluated the effectiveness of lutein in reducing preterm and term infant morbidity, reporting no definitive results. The challenge for the future is to better clarify the timing, the optimal dose and the duration of lutein intervention in perinatal period and to verify its impact on infants’ health. Proceedings of the 10th International Workshop on Neonatology · Cagliari (Italy · October 22nd-25th, 2014 · The last ten years, the next ten years in Neonatology Guest Editors: Vassilios Fanos, Michele Mussap, Gavino Faa, Apostolos Papageorgiou

Effects of oxide traps, interface traps, and ''border traps'' on metal-oxide-semiconductor devices

International Nuclear Information System (INIS)

Fleetwood, D.M.; Winokur, P.S.; Reber, R.A. Jr.; Meisenheimer, T.L.; Schwank, J.R.; Shaneyfelt, M.R.; Riewe, L.C.

1993-01-01

We have identified several features of the 1/f noise and radiation response of metal-oxide-semiconductor (MOS) devices that are difficult to explain with standard defect models. To address this issue, and in response to ambiguities in the literature, we have developed a revised nomenclature for defects in MOS devices that clearly distinguishes the language used to describe the physical location of defects from that used to describe their electrical response. In this nomenclature, ''oxide traps'' are simply defects in the SiO 2 layer of the MOS structure, and ''interface traps'' are defects at the Si/SiO 2 interface. Nothing is presumed about how either type of defect communicates with the underlying Si. Electrically, ''fixed states'' are defined as trap levels that do not communicate with the Si on the time scale of the measurements, but ''switching states'' can exchange charge with the Si. Fixed states presumably are oxide traps in most types of measurements, but switching states can either be interface traps or near-interfacial oxide traps that can communicate with the Si, i.e., ''border traps'' [D. M. Fleetwood, IEEE Trans. Nucl. Sci. NS-39, 269 (1992)]. The effective density of border traps depends on the time scale and bias conditions of the measurements. We show the revised nomenclature can provide focus to discussions of the buildup and annealing of radiation-induced charge in non-radiation-hardened MOS transistors, and to changes in the 1/f noise of MOS devices through irradiation and elevated-temperature annealing

The Effect of Zinc Oxide Nanoparticles on Safflower Plant Growth and Physiology

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Z. Hafizi

2018-02-01

Full Text Available In this paper, a study of the effect of ZnO nanoparticles on safflower growth and physiology was performed. Each of these elements plays a particular role in the plant life, the presence of these elements is necessary for plant’s life cycle and growth. Zinc deficiency causes the biggest problems in safflower’s production. Considering the importance of nanoparticles in today's world, this research investigated the effect of Zinc oxide nanoparticles on the concentration of guaiacol peroxidase, polypeptide oxidase, dehydrogenase and malondialdehyde in four plant sample groups in greenhouse and laboratory conditions. Results of showed that malondialdehyde enzyme increased with different treatments of various concentrations of Zinc oxide. The enzyme guaiacol oxidase increased at concentrations of 100 mg/L and polyphenol oxide at concentrations of 10 and 500 mg/L and dehydrogenase in 1000 mg/L and decreased in other treatments. In addition to showing the effect of nanoparticles in plants, these findings determine the beneficial concentrations of nanoparticles that have a positive effect on the level of enzymes in plants.

Effect of excess ozone on UV-stimulated tritium oxidation

International Nuclear Information System (INIS)

Hasegawa, Kiyoshi; Horii, Kazuhiro; Matsuyama, Masao; Watanabe, Kuniaki.

1995-01-01

The authors have reported that the oxidation of tritium is considerably accelerated by irradiating a mixture gas of HT(H 2 )-O 2 with UV-photons, and this UV-stimulated HT oxidation is mainly due to the formation of intermediates such as ozone and activated oxygen species. This suggests that the oxidation will be much more enhanced in the presence of excess ozone in the reaction system. To examine this possibility, effects of the excess ozone on the UV-stimulated HT oxidation was experimentally studied on the one hand, and reaction mechanisms were investigated by developing a computer simulation program applicable to the three-component system of HT(H 2 )-O 2 -O 3 . The formation rate of HTO was measured for gas mixtures consisting of O 2 (75.5 Torr), O 3 (0.5-2% of O 2 ), H 2 (0.1-3% of O 2 ) and HT(H 2 /HT=12000). The experiments showed considerable enhancement of the HTO production rate in the presence of excess ozone by UV-photons from a low pressure mercury lamp(5W). The time course of the reaction was reproduced quite well by computer simulation, indicating that the assumed reaction mechanism is valid. This is also supported by observations that computer simulation reproduced the experimentally observed dependence of ozone decomposition rate on ozone and hydrogen pressures under the UV-irradiation. Those results showed that UV-stimulated HT oxidation was accelerated by about 14000 times in the presence of excess ozone. It strongly suggests that the UV-stimulated oxidation in the presence of excess ozone will be applicable to tritium handling systems as a non-catalytic tritium removal method. (author)

Effect of TEMPO-oxidization and rapid cooling on thermo-structural properties of nanocellulose.

Science.gov (United States)

Mhd Haniffa, Mhd Abd Cader; Ching, Yern Chee; Chuah, Cheng Hock; Yong Ching, Kuan; Nazri, Nik; Abdullah, Luqman Chuah; Nai-Shang, Liou

2017-10-01

Recently, surface functionality and thermal property of the green nanomaterials have received wide attention in numerous applications. In this study, microcrystalline cellulose (MCC) was used to prepare the nanocrystalline celluloses (NCCs) using acid hydrolysis method. The NCCs was treated with TEMPO [(2,2,6,6-tetramethylpiperidin-1-yl)oxy radical]-oxidation to prepare TEMPO-oxidized NCCs. Cellulose nanofibrils (CNFs) also prepared from MCC using TEMPO-oxidation. The effects of rapid cooling and chemical treatments on the thermo-structural property studies of the prepared nanocelluloses were investigated through FTIR, thermogravimetric analysis-derivative thermogravimetric (TGA-DTG), and XRD. A posteriori knowledge of the FTIR and TGA-DTG analysis revealed that the rapid cooling treatment enhanced the hydrogen bond energy and thermal stability of the TEMPO-oxidized NCC compared to other nanocelluloses. XRD analysis exhibits the effect of rapid cooling on pseudo 2 I helical conformation. This was the first investigation performed on the effect of rapid cooling on structural properties of the nanocellulose. Copyright © 2017 Elsevier Ltd. All rights reserved.

Intrinsic stress of bismuth oxide thin films: effect of vapour chopping and air ageing

International Nuclear Information System (INIS)

Patil, R B; Puri, R K; Puri, V

2008-01-01

Bismuth oxide thin films of thickness 1000 A 0 have been prepared by thermal oxidation (in air) of vacuum evaporated bismuth thin films (on glass substrate) at different oxidation temperatures and duration. Both the vapour chopped and nonchopped bismuth oxide thin films showed polycrystalline and polymorphic structure. The monoclinic bismuth oxide was found to be predominant in both the cases. The effect of vapour chopping and air exposure for 40 days on the intrinsic stress of bismuth oxide thin films has been studied. The vapour chopped films showed low (3.92 - 4.80 x 10 9 N/m 2 ) intrinsic stress than those of nonchopped bismuth oxide thin films (5.77 - 6.74 x 10 9 N/m 2 ). Intrinsic stress was found to increase due to air ageing. The effect of air ageing on the vapour chopped films was found low. The vapour chopped films showed higher packing density. Higher the packing density, lower the film will age. The process of chopping vapour flow creates films with less inhomogenety i.e. a low concentration of flaws and non-planar defects which results in lower intrinsic stress

Perceived functional impact of abnormal facial appearance.

Science.gov (United States)

Rankin, Marlene; Borah, Gregory L

2003-06-01

Functional facial deformities are usually described as those that impair respiration, eating, hearing, or speech. Yet facial scars and cutaneous deformities have a significant negative effect on social functionality that has been poorly documented in the scientific literature. Insurance companies are declining payments for reconstructive surgical procedures for facial deformities caused by congenital disabilities and after cancer or trauma operations that do not affect mechanical facial activity. The purpose of this study was to establish a large, sample-based evaluation of the perceived social functioning, interpersonal characteristics, and employability indices for a range of facial appearances (normal and abnormal). Adult volunteer evaluators (n = 210) provided their subjective perceptions based on facial physical appearance, and an analysis of the consequences of facial deformity on parameters of preferential treatment was performed. A two-group comparative research design rated the differences among 10 examples of digitally altered facial photographs of actual patients among various age and ethnic groups with "normal" and "abnormal" congenital deformities or posttrauma scars. Photographs of adult patients with observable congenital and posttraumatic deformities (abnormal) were digitally retouched to eliminate the stigmatic defects (normal). The normal and abnormal photographs of identical patients were evaluated by the large sample study group on nine parameters of social functioning, such as honesty, employability, attractiveness, and effectiveness, using a visual analogue rating scale. Patients with abnormal facial characteristics were rated as significantly less honest (p = 0.007), less employable (p = 0.001), less trustworthy (p = 0.01), less optimistic (p = 0.001), less effective (p = 0.02), less capable (p = 0.002), less intelligent (p = 0.03), less popular (p = 0.001), and less attractive (p = 0.001) than were the same patients with normal facial

Effect of eicosapentaenoic and docosahexaenoic acid on resting and exercise-induced inflammatory and oxidative stress biomarkers: a randomized, placebo controlled, cross-over study

Directory of Open Access Journals (Sweden)

Galpin Andrew J

2009-08-01

Full Text Available Abstract Background The purpose of the present investigation was to determine the effects of EPA/DHA supplementation on resting and exercise-induced inflammation and oxidative stress in exercise-trained men. Fourteen men supplemented with 2224 mg EPA+2208 mg DHA and a placebo for 6 weeks in a random order, double blind cross-over design (with an 8 week washout prior to performing a 60 minute treadmill climb using a weighted pack. Blood was collected pre and post exercise and analyzed for a variety of oxidative stress and inflammatory biomarkers. Blood lactate, muscle soreness, and creatine kinase activity were also measured. Results Treatment with EPA/DHA resulted in a significant increase in blood levels of both EPA (18 ± 2 μmol·L-1 vs. 143 ± 23 μmol·L-1; p -1 vs. 157 ± 13 μmol·L-1; p 0.05. There was a mild increase in oxidative stress in response to exercise (XO and H2O2 (p Conclusion EPA/DHA supplementation increases blood levels of these fatty acids and results in decreased resting levels of inflammatory biomarkers in exercise-trained men, but does not appear necessary for exercise-induced attenuation in either inflammation or oxidative stress. This may be due to the finding that trained men exhibit a minimal increase in both inflammation and oxidative stress in response to moderate duration (60 minute aerobic exercise.

Effect of nitrous oxide on cisatracurium infusion demands: a randomized controlled trial

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Illman Hanna L

2010-08-01

Full Text Available Abstract Background Recent studies have questioned our previous understanding on the effect of nitrous oxide on muscle relaxants, since nitrous oxide has been shown to potentiate the action of bolus doses of mivacurium, rocuronium and vecuronium. This study was aimed to investigate the possible effect of nitrous oxide on the infusion requirements of cisatracurium. Methods 70 ASA physical status I-III patients aged 18-75 years were enrolled in this randomized trial. The patients were undergoing elective surgery requiring general anesthesia with a duration of at least 90 minutes. Patients were randomized to receive propofol and remifentanil by target controlled infusion in combination with either a mixture of oxygen and nitrous oxide (Nitrous oxide/TIVA group or oxygen in air (Air/TIVA group. A 0.1 mg/kg initial bolus of cisatracurium was administered before tracheal intubation, followed by a closed-loop computer controlled infusion of cisatracurium to produce and maintain a 90% neuromuscular block. Cumulative dose requirements of cisatracurium during the 90-min study period after bolus administration were measured and the asymptotic steady state rate of infusion to produce a constant 90% block was determined by applying nonlinear curve fitting to the data on the cumulative dose requirement during the study period. Results Controller performance, i.e. the ability of the controller to maintain neuromuscular block constant at the setpoint and patient characteristics were similar in both groups. The administration of nitrous oxide did not affect cisatracurium infusion requirements. The mean steady-state rates of infusion were 0.072 +/- 0.018 and 0.066 +/- 0.017 mg * kg-1 * h-1 in Air/TIVA and Nitrous oxide/TIVA groups, respectively. Conclusions Nitrous oxide does not affect the infusion requirements of cisatracurium. Trial registration ClinicalTrials.gov NCT01152905; European Clinical Trials Database at http://eudract.emea.eu.int/2006-006037-41.

Modulatory effects of caffeine on oxidative stress and anxiety-like behavior in ovariectomized rats.

Science.gov (United States)

Caravan, Ionut; Sevastre Berghian, Alexandra; Moldovan, Remus; Decea, Nicoleta; Orasan, Remus; Filip, Gabriela Adriana

2016-09-01

Menopause is accompanied by enhanced oxidative stress and behavioral changes, effects attenuated by antioxidants. The aim of this study was to evaluate the effects of caffeine on behavior and oxidative stress in an experimental model of menopause. Female rats were divided into the following groups: sham-operated (CON), sham-operated and caffeine-treated (CAF), ovariectomized (OVX), ovariectomized and caffeine-treated (OVX+CAF). Caffeine (6 mg/kg) and vehicle were administered for 21 days (subchronic) and 42 days (chronic), using 2 experimental subsets. Behavioral tests and oxidative stress parameters in the blood, whole brain, and hippocampus were assessed. The subchronic administration of caffeine decreased the lipid peroxidation and improved the antioxidant defense in the blood and brain. The GSH/GGSG ratio in the brain was improved by chronic administration, with reduced activities of antioxidant enzymes and enhanced nitric oxide and malondialdehyde levels. In particular, the lipid peroxidation in the hippocampus decreased in both experiments. The rats became hyperactive after 21 days of treatment, but no effect was observed after chronic administration. In both experimental subsets, caffeine had anxiolytic effects as tested in elevated plus maze. The administration of low doses of caffeine, for a short period of time, may be a new therapeutic approach to modulating the oxidative stress and anxiety in menopause.

Effects of dew point on selective oxidation of TRIP steels containing Si, Mn, and B

Science.gov (United States)

Lee, Suk-Kyu; Kim, Jong-Sang; Choi, Jin-Won; Kang, Namhyun; Cho, Kyung-Mox

2011-04-01

The selective oxidation of Si, Mn, and B on TRIP steel surfaces is a widely known phenomenon that occurs during heat treatment. However, the relationship between oxide formation and the annealing factors is not completely understood. This study examines the effect of the annealing conditions (dew point and annealing temperature) on oxide formation. A low dew point of -40 °C leads to the formation of Si-based oxides on the surface. A high dew point of -20 °C changes the oxide type to Mn-based oxides because the formation of Si oxides on the surface is suppressed by internal oxidation. Mn-based oxides exhibit superior wettability due to aluminothermic reduction during galvanizing.

Gastrointestinal function in chronic radiation enteritis -effects of loperamide-N-oxide

International Nuclear Information System (INIS)

Yeoh, E.K.; Horowitz, M.; Russo, A.; Muecke, T.; Chatterton, B.E.; Robb, T.

1993-01-01

The effects of loperamide-N-oxide, a new peripheral opiate agonist precursor, on gastrointestinal function were evaluated in 18 patients with diarrhoea caused by radiation enteritis. Each patient was given loperamide-N-oxide and placebo for 14 days, separated by a washout period of 14 days. Gastrointestinal symptoms; absorption of bile acid, vitamin B12, lactose, and fat; gastric emptying; small intestinal and whole gut transit; and intestinal permeability were measured during placebo and loperamide-N-oxide phases. Data were compared with those obtained in 18 normal subjects. In the patient, in addition to an increased frequency of bowel actions there was reduced bile acid absorption, higher prevalence of lactose malabsorption associated with a reduced dietary intake of dairy products and faster small intestinal and whole gut transit when compared with the normal subjects. There was no significant difference in gastric emptying between the two groups. Treatment with loperamide-N-oxide was associated with a reduced frequency of bowel actions, slower small intestinal and total gut transit, more rapid gastric emptying improved absorption of bile acid and increased permeability to 51 Cr EDTA. These observations indicate that: (1) diarrhoea caused by chronic radiation enteritis is associated with more rapid intestinal transit and a high prevalence of bile acid and lactose malabsorption, and (2) loperamide-N-oxide slows small intestinal transit, increases bile acid absorption, and is effective in the treatment of diarrhoea associated with chronic radiation enteritis. (Author)

The Effect of the Concentration of Oxidant, Cr(VI), on the Iron Oxidation in Saline Water

Science.gov (United States)

Ahn, H.; Jo, H. Y.; Ryu, J. H.; Koh, Y. K.

2014-12-01

Deep geological disposal is currently considered as the most appropriate method to isolate high level radioactive wastes (HLRWs) from the ecosystem. If groundwater seeps into underground disposal facilities, water molecules can be dissociated to radicals or peroxides, which can oxidize metal canisters and HLRWs. The oxidized radionuclides with a high solubility can be dissolved in the groundwater. Some dissolved radionuclides can act as oxidants. The continuous radiolysis of water molecules, which results from continuous seepage of groundwater, can enable the continuous production of the radioactive oxidants, resulting in an increase in concentration of oxidants. In this study, the effect of oxidant concentration on iron oxidation in the presence of salt was evaluated. Zero valent iron (ZVI) particles were reacted with Cr(VI) solutions with initial Cr(VI) concentrations ranged from 50 to 300 mg/L in reactors. The initial pH and NaCl concentration were fixed at 3 and 0.5 M, respectively. An increase in the initial Cr(VI) concentration caused an increase in the rate and extend of H2 gas production. The decrement of Cr(VI) was increased as the initial Cr(VI) concentration was increased. The penetration of H+ ions in the presence Cl- ions through the passive film on the ZVI particles caused the reaction between H+ ions and ZVI particles, producing H2 gas and Fe2+ ions. The passive film was damaged during the reaction due to the eruption of H2 gas or peptization by Cl- ions. The Fe2+ ions were reacted with Cr(VI) ions in the solution, producing Fe(III)-Cr(III) (oxy)hydroxides on the passive film of ZVI particles or in the solution as colloidal particles. The Fe(III)-Cr(III) (oxy)hydroxides tends to be precipitated as colloidal particles at a high Cr(VI) concentration and precipitated on the passive film at a low Cr(VI) concentration. The passive film was repaired or thickened by additional formation of Fe(III)-Cr(III) (oxy)hydroxides at a lower Cr(VI) concentration.

Effect of nickel oxide substitution on bioactivity and mechanical ...

Indian Academy of Sciences (India)

In the present work, the effect of addition of nickel oxide that annualizes the .... for required dimension using grinding machine, then sam- ples were subjected to ... the hardness testing machine, the size of the sample was. 10 × 10 × 10 mm ...

Separation of effects of oxide-trapped charge and interface-trapped charge on mobility in irradiated power MOSFETs

International Nuclear Information System (INIS)

Zupac, D.; Galloway, K.F.; Khosropour, P.; Anderson, S.R.; Schrimpf, R.D.

1993-01-01

An effective approach to separating the effects of oxide-trapped charge and interface-trapped charge on mobility degradation in irradiated MOSFETs is demonstrated. It is based on analyzing mobility data sets which have different functional relationships between the radiation-induced-oxide-trapped charge and interface-trapped charge. Separation of effects of oxide-trapped charge and interface-trapped charge is possible only if these two trapped charge components are not linearly dependent. A significant contribution of oxide-trapped charge to mobility degradation is demonstrated and quantified

The effect of nitric oxide releasing cream on healing pressure ulcers

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Vahid Saidkhani

2016-01-01

Full Text Available Background: Pressure ulcer is one of the main concerns of nurses in medical centers around the world, which, if untreated, causes irreparable problems for patients. In recent years, nitric oxide (NO has been proposed as an effective method for wound healing. This study was conducted to determine the effect of nitric oxide on pressure ulcer healing. Materials and Methods: In this clinical trial, 58 patients with pressure ulcer at hospitals affiliated to Ahvaz Jundishapur University of Medical Sciences were homogenized and later divided randomly into two groups of treatment (nitric oxide cream; n = 29 and control (placebo cream; n = 29. In this research, the data collection tool was the Pressure Ulcer Scale for Healing (PUSH. At the outset of the study (before using the cream, the patients' ulcers were examined weekly in terms of size, amount of exudates, and tissue type using the PUSH tool for 3 weeks. By integrating these three factors, wound healing was determined. Data were analyzed using SPSS. Results: Although no significant difference was found in terms of the mean of score size, the amount of exudates, and the tissue type between the two groups, the mean of total score (healing between the two groups was statistically significant (P = 0.04. Conclusions: Nitric oxide cream seems to accelerate wound healing. Therefore, considering its easy availability and cost-effectiveness, it can be used for treating pressure ulcers in the future.

The effect of nitric oxide releasing cream on healing pressure ulcers

Science.gov (United States)

Saidkhani, Vahid; Asadizaker, Marziyeh; Khodayar, Mohammad Javad; Latifi, Sayed Mahmoud

2016-01-01

Background: Pressure ulcer is one of the main concerns of nurses in medical centers around the world, which, if untreated, causes irreparable problems for patients. In recent years, nitric oxide (NO) has been proposed as an effective method for wound healing. This study was conducted to determine the effect of nitric oxide on pressure ulcer healing. Materials and Methods: In this clinical trial, 58 patients with pressure ulcer at hospitals affiliated to Ahvaz Jundishapur University of Medical Sciences were homogenized and later divided randomly into two groups of treatment (nitric oxide cream; n = 29) and control (placebo cream; n = 29). In this research, the data collection tool was the Pressure Ulcer Scale for Healing (PUSH). At the outset of the study (before using the cream), the patients' ulcers were examined weekly in terms of size, amount of exudates, and tissue type using the PUSH tool for 3 weeks. By integrating these three factors, wound healing was determined. Data were analyzed using SPSS. Results: Although no significant difference was found in terms of the mean of score size, the amount of exudates, and the tissue type between the two groups, the mean of total score (healing) between the two groups was statistically significant (P = 0.04). Conclusions: Nitric oxide cream seems to accelerate wound healing. Therefore, considering its easy availability and cost-effectiveness, it can be used for treating pressure ulcers in the future. PMID:27186212

Trap state passivation improved hot-carrier instability by zirconium-doping in hafnium oxide in a nanoscale n-metal-oxide semiconductor-field effect transistors with high-k/metal gate

International Nuclear Information System (INIS)

Liu, Hsi-Wen; Tsai, Jyun-Yu; Liu, Kuan-Ju; Lu, Ying-Hsin; Chang, Ting-Chang; Chen, Ching-En; Tseng, Tseung-Yuen; Lin, Chien-Yu; Cheng, Osbert; Huang, Cheng-Tung; Ye, Yi-Han

2016-01-01

This work investigates the effect on hot carrier degradation (HCD) of doping zirconium into the hafnium oxide high-k layer in the nanoscale high-k/metal gate n-channel metal-oxide-semiconductor field-effect-transistors. Previous n-metal-oxide semiconductor-field effect transistor studies demonstrated that zirconium-doped hafnium oxide reduces charge trapping and improves positive bias temperature instability. In this work, a clear reduction in HCD is observed with zirconium-doped hafnium oxide because channel hot electron (CHE) trapping in pre-existing high-k bulk defects is the main degradation mechanism. However, this reduced HCD became ineffective at ultra-low temperature, since CHE traps in the deeper bulk defects at ultra-low temperature, while zirconium-doping only passivates shallow bulk defects.

Impedance analysis of nanostructured iridium oxide electrocatalysts

International Nuclear Information System (INIS)

Sunde, Svein; Lervik, Ingrid Anne; Tsypkin, Mikhail; Owe, Lars-Erik

2010-01-01

Impedance data were collected for nanostructured iridium oxide (NIROF) at potentials below those at which the oxygen evolution reaction commences. The measurements included thin oxide films covered by a protective Nafion TM layer and thicker composite Nafion TM -oxide electrodes. The time constants for the low-frequency diffusion process were approximately the same for both types of electrodes, indicating diffusion in individual particles in the porous electrode rather than across the film. The diffusion process involves trapping of the diffusion species. The impedance data indicated that there were no significant variations in conductivity of the oxides with potential, as opposed to what appears to be the case for anodically formed iridium oxide films (AIROF). This is interpreted to reflect differences in electronic structure between NIROF and AIROF.

Kinetics of abiotic nitrous oxide production via oxidation of hydroxylamine by particulate metals in seawater

Science.gov (United States)

Cavazos, A. R.; Taillefert, M.; Glass, J. B.

2016-12-01

The oceans are a significant of nitrous oxide (N2O) to the atmosphere. Current models of global oceanic N2­O flux focus on microbial N2O cycling and often ignore abiotic reactions, such as the thermodynamically favorable oxidation of the nitrification intermediate hydroxylamine (NH2OH) by Mn(IV) or Fe(III). At circumneutral pH, NH2OH oxidation is more thermodynamically favorable via Mn(IV) than Fe(III) reduction. We characterized the kinetics of NH2OH oxidation in synthetic ocean water at pH 5.1-8.8 using microsensor electrodes to measure real-time N2O production. N2O production rates and yield were greater when NH2OH was oxidized by Mn(IV) than Fe(III). Accordingly, the reduction of Mn(IV) was first order with respect to NH2OH whereas the reduction of Fe(III) was zero order with respect to NH2OH. Interestingly, the order of the reaction with respect to Mn(IV) appears to be negative whereas the reaction is second order with respect to Fe(III). The inverse order with respect to Mn(IV) may be due to the aggregation of particles in seawater, which decreases their surface area and changes their reactivity. Finally, the reaction is first order with respect to protons with Fe(III) as the oxidant but zero order with Mn(IV). The stronger effect of the pH on the reaction with Fe(III) as the oxidant compared to Mn(IV) reflects the stoichiometry of these two reactions, as each mole of N2O produced by Fe(III) reduction consumes eight protons while each mole of N2O produced with Mn(IV) as the oxidant requires only four protons. Our data show that abiotic NH2OH oxidation by Mn(IV) or Fe(III) particles may represent a significant source of N2O in seawater. These findings suggest that abiotic N2O production in marine waters may be significant in areas of the oceans where particulate metals originating from aerosols, dust, or rivers may react with NH2OH released from ammonia-oxidizing microorganisms.

Comparison of the protective effects of seven selected herbs against oxidative stress

Directory of Open Access Journals (Sweden)

Lee-Wen Chang

2015-07-01

Full Text Available Objective: To compare the protective effects of the water extracts of seven herbs, including Solanum indicum L., Mallotus repandus (Wild Muell-Arg. (MRM, Bombax malabarica DC (BMDC, Tadehagi triquetrum (L. Ohashi (TTLO, Clinacanthus nutans (Burm f. Lindau, Salvia plebeia R. Br (SPRB, Ixeris chinensis Mak (ICM, against tert-butylhydroperoxide (t-BHP-induced oxidative stress in Clone 9 cells. Methods: To evaluate the antioxidant properties of water extracts from seven herbs, reducing ability, metal-chelating activity and radical-scavenging activity such as 2,2′-azino-bis(3- ethylbenzothiazoline-6-sulphonic acid radical cation and 1,1-diphenyl-2-picrylhydrazyl (DPPH were determined. In cellular systems, t-BHP was used as a model oxidant to induce oxidative stress. 2′,7′-Dichlorofluorescin diacetate and chloromethylfluorescein-diacetate were used as fluorescence probe to determine reactive oxygen species generation and glutathione level in t-BHP-induced Clone 9 cells, respectively. In addition, total tannins, total anthocyanins, total polyphenolics and flavonoids were determined. Results: According to the data obtained from the trolox equivalent antioxidant capacity method, DPPH radical scavenging assay and reducing ability determination, MRM, SPRB, and BMDC showed relatively high antioxidant properties while TTLO and ICM were in the middle and Solanum indicum and Clinacanthus nutans had relatively low activity. In cellular model systems, SPRB, BMDC, and TTLO showed higher protective effects against t-BHP-induced oxidative stress. BMDC, ICM, and TTLO displayed higher inhibitory effects on reactive oxygen species generation in t-BHP-induced Clone 9 cells. In addition, SPRB, MRM, and BMDC showed significantly positive modulated glutathione levels. Tannins, anthocyanins, flavonoids and polyphenolics were present in the herbs, which may in part contribute to regulating the oxidative stress. Conclusions: These results indicated that the seven

Effects of quantum coupling on the performance of metal-oxide ...

Indian Academy of Sciences (India)

LING-FENG MAO. School of Electronics & Information Engineering, Soochow University, ... Quantum coupling; metal-oxide-semiconductor field transistors. ... effects of the barrier height reduction caused by the channel electron velocity due to.

Moessbauer effect and infrared study of some borate glass containing Mn and Fe oxides

International Nuclear Information System (INIS)

Gabr, M.

2005-01-01

Lithium borate glasses containing transition metals appeared now of very high technological and scientific interest. Therefore some lithium borate glasses containing mixed transition metal ions (manganese and iron) were investigated. The glass batches were melted at 1250 degree C for three hours and annealed at 350 degree C -over night- to obtain strain free glasses. Moessbauer Effect spectroscopy and Infrared analysis were employed to investigate the structural changes due to the change of their batches composition. Differential thermal analysis, magnetic susceptibility, density and molar volume measurements were also performed to study the effect of changing both manganese and iron oxides at the expense of boron oxide on these properties. Infrared analysis indicated the presence of different structural groups such as BO 3 , BO 4 , FeO 4 and MnO 6 as well as different vibrations indicated the presence of various bonds in the glass network. The values of the characteristic temperatures (T g , T c and T m ) showed gradual increase except those of the last sample where they showed a decrease. The mid sample showed the lowest stability value. It was found that the molar volume showed its highest value at R=0.33 [where R is the ratio of glass network modifier to the glass network former]. After that it showed gradual linear decrease. The magnetic susceptibility measurements showed approximately stable value between R=0.29 and 0.33, then it increased up to R=0.38, and after that, it decreased up to R= 0.43. The obtained magnetic susceptibility values indicated that all these glasses are paramagnetic. The obtained Moessbauer spectra and the calculated parameters confirmed that iron ions participated in the glass network as network former cations. It confirmed also that all glasses reflect paramagnetic character. The observed structural change were explained and correlated with the change of the measured physical properties

Synergistic effect of graphene oxide on the methanol oxidation for fuel cell application

Science.gov (United States)

Siwal, Samarjeet; Ghosh, Sarit; Nandi, Debkumar; Devi, Nishu; Perla, Venkata K.; Barik, Rasmita; Mallick, Kaushik

2017-09-01

Aromatic polypyrene was synthesized by the oxidative polymerization of pyrene with potassium tetrachloropalladate (II), as oxidant. During the polymerization process the palladium salt was reduced to metallic palladium and forms the metal-polymer composite material. Polypyrene stabilized palladium nanoparticles showed electrocatalytic activity toward the oxidation of methanol. The performance of the electrocatalytic activity was substantially improved with the incorporation of graphene oxide to the palladium-polypyrene composite and the synergistic performance was attributed to the electronic and structural properties of the system.

Low Dimensionality Effects in Complex Magnetic Oxides

Science.gov (United States)

Kelley, Paula J. Lampen

Complex magnetic oxides represent a unique intersection of immense technological importance and fascinating physical phenomena originating from interwoven structural, electronic and magnetic degrees of freedom. The resulting energetically close competing orders can be controllably selected through external fields. Competing interactions and disorder represent an additional opportunity to systematically manipulate the properties of pure magnetic systems, leading to frustration, glassiness, and other novel phenomena while finite sample dimension plays a similar role in systems with long-range cooperative effects or large correlation lengths. A rigorous understanding of these effects in strongly correlated oxides is key to manipulating their functionality and device performance, but remains a challenging task. In this dissertation, we examine a number of problems related to intrinsic and extrinsic low dimensionality, disorder, and competing interactions in magnetic oxides by applying a unique combination of standard magnetometry techniques and unconventional magnetocaloric effect and transverse susceptibility measurements. The influence of dimensionality and disorder on the nature and critical properties of phase transitions in manganites is illustrated in La0.7 Ca0.3MnO3, in which both size reduction to the nanoscale and chemically-controlled quenched disorder are observed to induce a progressive weakening of the first-order nature of the transition, despite acting through the distinct mechanisms of surface effects and site dilution. In the second-order material La0.8Ca0.2MnO3, a strong magnetic field is found to drive the system toward its tricritical point as competition between exchange interactions in the inhomogeneous ground state is suppressed. In the presence of large phase separation stabilized by chemical disorder and long-range strain, dimensionality has a profound effect. With the systematic reduction of particle size in microscale-phase-separated (La, Pr

Anodic ammonia oxidation to nitrogen gas catalyzed by mixed biofilms in bioelectrochemical systems

International Nuclear Information System (INIS)

Zhan, Guoqiang; Zhang, Lixia; Tao, Yong; Wang, Yujian; Zhu, Xiaoyu; Li, Daping

2014-01-01

In this paper we report ammonia oxidation to nitrogen gas using microbes as biocatalyst on the anode, with polarized electrode (+600 mV vs. Ag/AgCl) as electron acceptor. In batch experiments, the maximal rate of ammonia-N oxidation by the mixed culture was ∼ 60 mg L −1 d −1 , and nitrogen gas was the main products in anode compartment. Cyclic voltammetry for testing the electroactivity of the anodic biofilms revealed that an oxidation peak appeared at +600 mV (vs. Ag/AgCl), whereas the electrode without biofilms didn’t appear oxidation peak, indicating that the bioanode had good electroactivities for ammonia oxidation. Microbial community analysis of 16S rRNA genes based on high throughput sequencing indicated that the combination of the dominant genera of Nitrosomonas, Comamonas and Paracocus could be important for the electron transfer from ammonia oxidation to anode

Effects of electrolytes variation on formation of oxide layers of 6061 Al alloys by plasma electrolytic oxidation

Institute of Scientific and Technical Information of China (English)

Kai WANG; Bon-Heun KOO; Chan-Gyu LEE; Young-Joo KIM; Sung-Hun LEE; Eungsun BYON

2009-01-01

Plasma electrolytic oxidation(PEO) processes were carried out to produce ceramic layers on 6061 aluminum substrates in four kinds of electrolytes such as silicate and aluminate solution with and without sodium fluorosilicate. The PEO processes were carried out under a hybrid voltage (260 V DC combined with 200 V, 60 Hz AC amplitude) at room temperature for 5 min. The composition, microstructure and element distribution analyses of the PEO-treated layers were carried out by XRD and SEM & EDS. The effect of the electrolyte contents on the growth mechanism, element distribution and properties of oxide layers were studied. It is obvious that the layers generated in aluminate solutions show smoother surfaces than those in silicate solutions. Moreover, an addition of fluorine ion can effectively control the layer porosity; therefore, it can enhance the properties of the layers.

Oxidative stress in cardiovascular diseases

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Shyamal K Goswami

2015-01-01

Full Text Available Oxidative stress caused by various oxygen containing free radicals and reactive species (collectively called "Reactive Oxygen Species" or ROS has long been attributed to cardiovascular diseases. In human body, major oxidizing species are super oxide, hydrogen peroxide, hydroxyl radical, peroxy nitrite etc. ROS are produced from distinct cellular sources, enzymatic and non-enzymatic; have specific physicochemical properties and often have specific cellular targets. Although early studies in nineteen sixties and seventies highlighted the deleterious effects of these species, later it was established that they also act as physiological modulators of cellular functions and diseases occur only when ROS production is deregulated. One of the major sources of cellular ROS is Nicotinamide adenine dinucleotide phosphate oxidases (Noxes that are expressed in almost all cell types. Superoxide and hydrogen peroxide generated from them under various conditions act as signal transducers. Due to their immense importance in cellular physiology, various Nox inhibitors are now being developed as therapeutics. Another free radical of importance in cardiovascular system is nitric oxide (a reactive nitrogen species generated from nitric oxide synthase(s. It plays a critical role in cardiac function and its dysregulated generation along with superoxide leads to the formation of peroxynitrite a highly deleterious agent. Despite overwhelming evidences of association between increased level of ROS and cardiovascular diseases, antioxidant therapies using vitamins and omega 3 fatty acids have largely been unsuccessful till date. Also, there are major discrepancies between studies with laboratory animals and human trials. It thus appears that the biology of ROS is far complex than anticipated before. A comprehensive understanding of the redox biology of diseases is thus needed for developing targeted therapeutics.

Appearance of the minority dz2 surface state and disappearance of the image-potential state: Criteria for clean Fe(001)

Science.gov (United States)

Eibl, Christian; Schmidt, Anke B.; Donath, Markus

2012-10-01

The unoccupied surface electronic structure of clean and oxidized Fe(001) was studied with spin-resolved inverse photoemission and target current spectroscopy. For the clean surface, we detected a dz2 surface state with minority spin character just above the Fermi level, while the image-potential surface state disappears. The opposite is observed for the ordered p(1×1)O/Fe(001) surface: the dz2-type surface state is quenched, while the image-potential state shows up as a pronounced feature. This behavior indicates enhanced surface reflectivity at the oxidized surface. The appearance and disappearance of specific unoccupied surface states prove to be decisive criteria for a clean Fe(001) surface. In addition, enhanced spin asymmetry in the unoccupied states is observed for the oxidized surface. Our results have implications for the use of clean and oxidized Fe(001) films as spin-polarization detectors.

Effects of naringin on apoptosis and oxidative stress in type 2 diabetic rats

Science.gov (United States)

Adelani, Isaacson; Bankole, Esther; Rotimi, Oluwakemi; Rotimi, Solomon

2018-04-01

Oxidative stress and apoptosis have been reported to play major roles in the pathogenesis of Type 2 Diabetes Mellitus (T2DM) through insulin resistance and β-cell dysfunction. Naringin is a citrus derived flavonoid that has been reported for its antioxidant properties. Even though effects of naringin in T2DM related oxidative stress has been reported, varying dose concentration in oxidative stress and mechanism of action involving T2DM related apoptosis is far-fetched. This research studied the effects of naringin at varying dose concentration on apoptosis, biomarkers of organ function and oxidative stress in high fat diet/low-streptozotocin-induced T2DM in albino Wistar rats. Diabetic rats were treated with naringin at 50mg/kg, 100mg/kg and 200mg/kg body weight for 21 days. Some biomarkers of organ function and oxidative stress in the animals were assayed using spectrophotometric techniques. The levels of expression of caspases and apoptotic regulators were quantified using semi-quantitative reverse transcriptase polymerase chain reaction (RT PCR). Enzyme - linked immunosorbent assay was used to determine inducible nitric oxide synthase (iNOS) level. Naringin treatment shows a dose dependent significant (plipid peroxidation, glutathione- s-transferase, glutathione peroxidase and glutathione reductase activities in the liver. Naringin treatment also showed a significant (p<0.05) increase in the expression of caspase 3 and reduction in BCL-2 as against the diabetic control. In addition, there was dose dependent decrease in plasma CO2 concentration and increase in the plasma iNOS concentration as compared to the diabetic control. This result highlights positive effect of naringin as an antioxidant, its role in apoptosis and also reverting the effects of organ damage in type 2 diabetes.

Support Effects in the Gold-Catalyzed Preferential Oxidation of CO

KAUST Repository

Ivanova, S.

2010-04-08

The study of support effects on the gold-catalyzed preferential oxidation of carbon monoxide in the presence of hydrogen (PROX reaction) is possible only with careful control of the gold particle size, which is facilitated by the application of the direct anionic exchange method. Catalytic evaluation of thermally stable gold nanoparticles, with an average size of around 3 nm on a variety of supports (alumina, titania, zirconia, or ceria), clearly shows that the influence of the support on the CO oxidation rate is of primary importance under CO+O 2 conditions and that this influence becomes secondary in the presence of hydrogen. The impact of the support surface structure on the oxidation rates, catalyst selectivity, and catalyst activation/deactivation is investigated in terms of oxygen vacancies, oxygen mobility, OH groups, and surface area on the oxidation rates, catalyst selectivity and catalyst activation/deactivation. It allows the identification of key morphological and structural features of the support to ensure high activity and selectivity in the gold-catalyzed PROX reaction. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mechanisms of realization of THz-waves of nitrogen oxide occurrence physiological effects

Directory of Open Access Journals (Sweden)

Vyacheslav F. Kirichuk

2013-11-01

Full Text Available In this review, there is generalized material of many experimental researches in interaction of THz-waves molecular emission and absorption spectrum (MEAS of nitrogen oxide occurrence with bioobjects. Thrombocytes and experimental animals were used as bioobjects. The experiments let indicate changes caused by THz-waves: at the cellular, tissular, system, organismic levels. There are all data of changes in physiological mechanisms of reglations at all levels: autocrine, paracrine, endocrine and nervous. There is a complex overview of experimental material firstly performed in the article. There had been shown that the effect of THz-waves of the given occurrence is realized by the changed activity of nitroxidergic system. It had been proved that THz-waves of nitrogen oxide occurrence can stimulate nitrogen oxide producing in organs and tissues in condition of its low concentration. Possible mechanisms of antiaggregative effect of the given waves had been described. There had been shown the possibility of regulating of vascular tone and system hemodynamics with the help of the studying these frequencies. The represented data of lipid peroxidation and enzymatic and nonenzymatic components of organism system under the influence of THz-waves of nitrogen oxide occurrence in stress conditions. Besides, there were shown changes of stress-regulating system activity and in concentration of important mediators - catecholamines and glucocorticosteroids. These data let characterize mechanism of realization of THz-waves basic effects. The research had shown the possibility of THz-waves of nitrogen oxide occurrence usage as a method of natural physiological noninvasive regulation of significant organism functions.

Breaking the circle: challenging Western sociocultural norms for appearance influences young women's attention to appearance-related media.

Science.gov (United States)

Mischner, Isabelle H S; van Schie, Hein T; Engels, Rutger C M E

2013-06-01

Paying attention to thin media models may negatively affect women's self-evaluation. This study aimed to reduce the amount of attention that young women give to appearance-related information by challenging the sociocultural norms for appearance, and studied the moderating role of self-esteem. Seventy-one college women either received norm-confirming, norm-challenging, or no information regarding the sociocultural norms for appearance. Subsequently, participants' visual attention to appearance-related and neutral advertisements was measured using an eye-tracker. The results demonstrate that when no information or norm-confirming information was received, women with lower self-esteem paid more attention to the appearance-related advertisements than women with higher self-esteem. Importantly however, when norm-challenging information was received, women with lower self-esteem paid significantly less attention to the appearance-related ads than women with lower self-esteem who did not receive this manipulation. These findings indicate that challenging the sociocultural norms for appearance can attenuate the amount of attention women give to appearance-related media. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of bicarbonate on iron-mediated oxidation of low-density lipoprotein

Science.gov (United States)

Arai, Hirofumi; Berlett, Barbara S.; Chock, P. Boon; Stadtman, Earl R.

2005-07-01

Oxidation of low-density lipoprotein (LDL) may play an important role in atherosclerosis. We studied the effects of bicarbonate/CO2 and phosphate buffer systems on metal ion-catalyzed oxidation of LDL to malondialdehyde (MDA) and to protein carbonyl and MetO derivatives. Our results revealed that LDL oxidation in mixtures containing free iron or heme derivatives was much greater in bicarbonate/CO2 compared with phosphate buffer. However, when copper was substituted for iron in these mixtures, the rate of LDL oxidation in both buffers was similar. Iron-catalyzed oxidation of LDL was highly sensitive to inhibition by phosphate. Presence of 0.3-0.5 mM phosphate, characteristic of human serum, led to 30-40% inhibition of LDL oxidation in bicarbonate/CO2 buffer. Iron-catalyzed oxidation of LDL to MDA in phosphate buffer was inhibited by increasing concentrations of albumin (10-200 μM), whereas MDA formation in bicarbonate/CO2 buffer was stimulated by 10-50 μM albumin but inhibited by higher concentrations. However, albumin stimulated the oxidation of LDL proteins to carbonyl derivatives at all concentrations examined in both buffers. Conversion of LDL to MDA in bicarbonate/CO2 buffer was greatly stimulated by ADP, ATP, and EDTA but only when EDTA was added at a concentration equal to that of iron. At higher than stoichiometric concentrations, EDTA prevented oxidation of LDL. Results of these studies suggest that interactions between bicarbonate and iron or heme derivatives leads to complexes with redox potentials that favor the generation of reactive oxygen species and/or to the generation of highly reactive CO2 anion or bicarbonate radical that facilitates LDL oxidation. Freely available online through the PNAS open access option.Abbreviations: LDL, low-density lipoprotein; MDA, malondialdehyde; MetO, methionine sulfoxide.

Appearance of Keplerian discs orbiting Kerr superspinars

Energy Technology Data Exchange (ETDEWEB)

Stuchlik, Zdenek; Schee, Jan, E-mail: zdenek.stuchlik@fpf.slu.c, E-mail: jan.schee@fpf.slu.c [Institute of Physics, Faculty of Philosophy and Science, Silesian University in Opava, Bezrucovo nam. 13, Opava (Czech Republic)

2010-11-07

We study optical phenomena related to the appearance of Keplerian accretion discs orbiting Kerr superspinars predicted by string theory. The superspinar exterior is described by standard Kerr naked singularity geometry breaking the black hole limit on the internal angular momentum (spin). We construct local photon escape cones for a variety of orbiting sources that enable us to determine the superspinars silhouette in the case of distant observers. We show that the superspinar silhouette depends strongly on the assumed edge where the external Kerr spacetime is joined to the internal spacetime governed by string theory and significantly differs from the black hole silhouette. The appearance of the accretion disc is strongly dependent on the value of the superspinar spin in both their shape and frequency shift profile. Apparent extension of the disc grows significantly with the growing spin, while the frequency shift grows with the descending spin. This behaviour differs substantially from the appearance of discs orbiting black holes enabling thus, at least in principle, to distinguish clearly the Kerr superspinars and black holes. In vicinity of a Kerr superspinar the non-escaped photons have to be separated to those captured by the superspinar and those being trapped in its strong gravitational field leading to self-illumination of the disc that could even influence its structure and cause self-reflection effect of radiation of the disc. The amount of trapped photons grows with descending superspinar spin. We thus can expect significant self-illumination effects in the field of Kerr superspinars with near-extreme spin a {approx} 1.

Oxidized low-density lipoprotein in children with familial hypercholesterolemia and unaffected siblings: effect of pravastatin

NARCIS (Netherlands)

Rodenburg, Jessica; Vissers, Maud N.; Wiegman, Albert; Miller, Elizabeth R.; Ridker, Paul M.; Witztum, Joseph L.; Kastelein, John J. P.; Tsimikas, Sotirios

2006-01-01

OBJECTIVES: To assess the role of oxidized phospholipids (OxPLs) in children with familial hypercholesterolemia (FH) and the effect of pravastatin. BACKGROUND: Oxidized phospholipids are a major component of oxidized low-density lipoprotein (OxLDL) and are bound to lipoprotein (a) [Lp(a)]. The

Study of cryoprotectors effect on oxidation processes at storage of frozen halffinished products

Directory of Open Access Journals (Sweden)

O. Glushkov

2016-12-01

Full Text Available The publication presents data on the effect of polysaccharides as cryoprotectants on changes of the lipid fraction of quick-frozen semi-finished products during storage. Since the structure of minced systems is formed as a result of the destruction of the native structure of the meat and the formation of a new secondary structure, it is important to establish the effect of cryoprotectants on the key functional and technological properties of meat systems after freezing, and in the process of storage. Based on studies of the kinetics of the oxidation of fat and accumulation data on the accumulation of the primary and secondary products of oxidation inhibition of oxidative processes has been found.

Effects of prior surface damage on high-temperature oxidation of Fe-, Ni-, and Co-based alloys

Energy Technology Data Exchange (ETDEWEB)

Blau, Peter Julian [ORNL; Lowe, Tracie M [ORNL; Pint, Bruce A [ORNL

2009-01-01

Multi-component metallic alloys have been developed to withstand high-temperature service in corrosive environments. Some of these applications, like exhaust valve seats in internal combustion engines, must also resist sliding, impact, and abrasion. The conjoint effects of temperature, oxidation, and mechanical contact can result in accelerated wear and the formation of complex surface layers whose properties differ from those of the base metal and the oxide scale that forms in the absence of mechanical contact. The authors have investigated the effects of prior surface damage, produced by scratch tests, on the localized reformation of oxide layers. Three high-performance commercial alloys, based on iron, nickel, and cobalt, were used as model materials. Thermogravimetric analysis (TGA) was used to determine their static oxidation rates at elevated temperature (850o C). A micro-abrasion, ball-cratering technique was used to measure oxide layer thickness and to compare it with TGA results. By using taper-sectioning techniques and energy-dispersive elemental mapping, a comparison was made between oxide compositions grown on non-damaged surfaces and oxides that formed on grooves produced by a diamond stylus. Microindentation and scratch hardness data revealed the effects of high temperature exposure on both the substrate hardness and the nature of oxide scale disruption. There were significant differences in elemental distribution between statically-formed oxides and those that formed on scratched regions

A study on microwave oxidation of landfill leachate—Contributions of microwave-specific effects

International Nuclear Information System (INIS)

Chou, Yu-Chieh; Lo, Shang-Lien; Kuo, Jeff; Yeh, Chih-Jung

2013-01-01

Highlights: ► pH has an insignificant effect on TOC removals and 550 W has a well performance. ► MOP has well removals of color, UV 254 , and TOC at 550 W/85 °C. ► TOC removals were higher at higher microwave setting (550 W vs. 128 W). ► The microwave-specific effects on TOC removal were usually synergistic in MOP. ► COD analyses showed persulfate decayed rapidly in either MOP or CHO treatment. -- Abstract: Microwave oxidation process (MOP) was evaluated for treatment of landfill leachate. The experimental parameters include pH, temperature, oxidant doses, microwave power setting, and irradiation time. The study explored the microwave-specific effects of the MOP. The contributions of pure thermal, persulfate oxidation and microwave irradiation on TOC removal were quantified. It was then found the combinations of them were usually synergistic in MOP except two of them were antagonistic (128 W/85 °C/1 M Na 2 S 2 O 8 and 128 W/85 °C/2 M Na 2 S 2 O 8 ). At the highest temperature tested (85 °C) in this study, microwave irradiation may cause generation and termination of oxidizing radicals at adverse rates. The study also found that persulfate decayed rapidly in either MOP or conventional heating oxidation (CHO) treatment of landfill leachate

Effect of aerobic exercise intervention on DDT degradation and oxidative stress in rats.

Science.gov (United States)

Li, Kefeng; Zhu, Xiaohua; Wang, Yuzhan; Zheng, Shuqian; Dong, Guijun

2017-03-01

Dichlorodiphenyltrichloroethane (DDT) reportedly causes extensively acute or chronic effects to human health. Exercise can generate positive stress. We evaluated the effect of aerobic exercise on DDT degradation and oxidative stress. Male Wistar rats were randomly assigned into control (C), DDT without exercise training (D), and DDT plus exercise training (DE) groups. The rats were treated as follows: DDT exposure to D and DE groups at the first 2 weeks; aerobic exercise treatment only to the DE group from the 1st day until the rats are killed. DDT levels in excrements, muscle, liver, serum, and hearts were analyzed. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) levels were determined. Aerobic exercise accelerated the degradation of DDT primarily to DDE due to better oxygen availability and aerobic condition and promoted the degradation of DDT. Cumulative oxidative damage of DDT and exercise led to significant decrease of SOD level. Exercise resulted in consistent increase in SOD activity. Aerobic exercise enhanced activities of CAT and GSH-Px and promoted MDA scavenging. Results suggested that exercise can accelerate adaptive responses to oxidative stress and activate antioxidant enzymes activities. Exercise can also facilitate the reduction of DDT-induced oxidative damage and promoted DDT degradation. This study strongly implicated the positive effect of exercise training on DDT-induced liver oxidative stress.

Rye cover crop effects on nitrous oxide emissions from a corn-soybean system

Science.gov (United States)

Agricultural activities are a major source nitrous oxide emitted to the atmosphere. Development of management practices to reduce these emissions is needed. Non-leguminous cover crops are efficient scavengers of residual soil nitrate, but their effects on nitrous oxide emissions have not been well d...

The impact of forced social comparison on adolescents’ self-esteem and appearance satisfaction

Directory of Open Access Journals (Sweden)

Purić Danka

2011-01-01

Full Text Available The impact of forced social comparison on adolescents’ self-esteem and appearance satisfaction research, conducted on a sample of 133 high school seniors, consisted of two phases. In phase one, participants were given the Rosenberg Self-Esteem Inventory, Appearance Satisfaction Scale and Appearance Relevance Scale, and in phase two, one month later, they were exposed to photographs of attractive and unattractive individuals. Two groups of boys and girls each assessed attractive or unattractive individuals of their own gender, while two control groups (of both genders were not exposed to any photographs. Immediately after assessing the photographs, the participants were again given the Rosenberg Self-Esteem Inventory and Appearance Satisfaction Scale. We found that forced social comparison had an impact on self-esteem and a marginally significant effect on appearance satisfaction in the group of participants (of both genders assessing the photographs of unattractive individuals, while no effects were found in the either the control group or the group assessing the photographs of attractive individuals. We also examined the impact of self-esteem, appearance satisfaction and appearance relevance as moderating variables on the effect size of social comparison and showed that higher pretest self-esteem and appearance relevance and lower appearance satisfaction predict higher posttest self-esteem scores, regardless of the participants’ group membership. The group of participants exposed to photographs of unattractive people, however, showed the opposite pattern - those participants who had initially lower self-esteem have increased it more as a result of the experimental exposure.

Anti-oxidation and scavenging effects of some extracts from Chinese medicines on free radicals

International Nuclear Information System (INIS)

Wang Chongdao; Qiang Yizhong; Lao Qinhua; Cui Fengmei; Shao Yuan; Sun Cunpu

1999-11-01

The inhibiting effects of Chinonin, Quercetin and Tannic Acid on the lipid oxidation induced by radiation exposure were investigated by means of a modified TBA spectrophotometry. The scavenging effects on free radicals caused by γ-irradiation exposure of the three active principles were observed by technique of ESR. The results showed that anti-oxidation effects of Chinonin and Quercetin were better than that of Tannic Acid, while the scavenging effects of the three active principles on free radicals were similar

Oxidation of zirconium-aluminum alloys

International Nuclear Information System (INIS)

Cox, B.

1967-10-01

Examination of the processes occurring during the oxidation of Zr-1% A1, Zr-3% A1, and Zr-1.5% A1-0.5% Mo alloys has shown that in steam rapid oxidation occurs predominantly around the Zr 3 A1 particles, which at low temperatures appear to be relatively unattacked. The unoxidised particles become incorporated in the oxide, and become fully oxidised as the film thickens. This rapid localised oxidation is preceded by a short period of uniform film growth, during which the oxide film thickness does not exceed ∼200A-o. Thus the high oxidation rates can probably be ascribed to aluminum in solution in the zirconium matrix, although its precise mode of operation has not been determined. Once the solubility limit of aluminum is exceeded, the size, distribution and number of intermetallic particles affects the oxidation rate merely by altering the distribution of regions of metal giving high oxidation rates. The controlling process during the early stages of oxidation is electron transport and not ionic transport. Thus, the aluminum in the oxide film is presumably increasing the ionic conductivity more than the electronic. The oxidation rates in atmospheric pressure steam are very high and their irregular temperature dependence suggests that the oxidation rate will be pressure dependent. This was confirmed, in part, by a comparison with oxidation in moist air. It was found that the rate of development of white oxide around intermetallic particles was considerably reduced by the decrease in the partial pressure of H 2 O; the incubation period was not much different, however. (author)

Exciting imperfection. Real-structure effects in magnesium-, cadmium-, and zinc-oxide

Energy Technology Data Exchange (ETDEWEB)

Schleife, Andre

2010-07-01

We employ recent ab-initio methods and theoretical spectroscopy techniques that rely on heavy numerical calculations to describe electronic excitations in non-ideal crystals of three group-II oxides. We study the ideal equilibrium polymorphs of these oxides, for gaining a thorough understanding as well as the necessary confidence in our approaches to generalize and apply them to the electronic excitations in imperfect crystals. As such imperfections we take the influence of strain, the alloying of the different oxides, an intrinsic point defect, and free electrons in the lowest conduction band into account. We employ the DFT results as input in order to compute quasiparticle electronic structures, which are in good agreement with experimental findings. According to Hedin's equations for interacting electrons, the electron-hole interaction is taken into account by solving a Bethe-Salpeter equation for the polarization function. Thereafter the equilibrium polymorphs of ideal bulk MgO, ZnO, and CdO and investigates the structure of their valence and conduction bands are described. We present densities of states and effective masses, as well as natural band discontinuities. Furthermore, our description of the dielectric function, which takes excitonic effects into account, enables us to derive the electron-energy loss function. The influence of uniaxial and biaxial strain on the ordering of the valence bands in ZnO is investigated. In addition, we explore the electronic band structure of the non-equilibrium wurtzite structures of MgO and CdO. We predict valence-band splittings and band gaps as they might occur at interfaces of Mgo or CdO with ZnO substrates. Thereafter we study pseudobinary alloys by means of a cluster expansion method. Due to the different crystal structures of the respective oxides, i.e. rocksalt and wurtzite, the description of their heterostructural combination has to be achieved. The electronic and optical properties of the group-II oxide

Exciting imperfection. Real-structure effects in magnesium-, cadmium-, and zinc-oxide

International Nuclear Information System (INIS)

Schleife, Andre

2010-01-01

We employ recent ab-initio methods and theoretical spectroscopy techniques that rely on heavy numerical calculations to describe electronic excitations in non-ideal crystals of three group-II oxides. We study the ideal equilibrium polymorphs of these oxides, for gaining a thorough understanding as well as the necessary confidence in our approaches to generalize and apply them to the electronic excitations in imperfect crystals. As such imperfections we take the influence of strain, the alloying of the different oxides, an intrinsic point defect, and free electrons in the lowest conduction band into account. We employ the DFT results as input in order to compute quasiparticle electronic structures, which are in good agreement with experimental findings. According to Hedin's equations for interacting electrons, the electron-hole interaction is taken into account by solving a Bethe-Salpeter equation for the polarization function. Thereafter the equilibrium polymorphs of ideal bulk MgO, ZnO, and CdO and investigates the structure of their valence and conduction bands are described. We present densities of states and effective masses, as well as natural band discontinuities. Furthermore, our description of the dielectric function, which takes excitonic effects into account, enables us to derive the electron-energy loss function. The influence of uniaxial and biaxial strain on the ordering of the valence bands in ZnO is investigated. In addition, we explore the electronic band structure of the non-equilibrium wurtzite structures of MgO and CdO. We predict valence-band splittings and band gaps as they might occur at interfaces of Mgo or CdO with ZnO substrates. Thereafter we study pseudobinary alloys by means of a cluster expansion method. Due to the different crystal structures of the respective oxides, i.e. rocksalt and wurtzite, the description of their heterostructural combination has to be achieved. The electronic and optical properties of the group-II oxide alloys

Intergranular oxidation of austenistic stainless steels in steam at 6000C

International Nuclear Information System (INIS)

Hersubeno, Johannes Baptista de la Salle.

1981-11-01

The oxidation kinetics of a 17.13 bicrystalline and polycrystalline stainless steel was determined at 600 0 C in the presence of steam. The appearance, structure and composition of the oxides at the grain boundaries were particularly studied [fr

Effects of porosity and temperature on oxidation behavior in air of selected nuclear graphites

International Nuclear Information System (INIS)

Chen Dongyue; Li Zhengcao; Miao Wei; Zhang Zhengjun

2012-01-01

Nuclear graphite endures gas oxidation in High Temperature Gas-cooled Reactor (HTGR), which may threaten the safety of reactor. To study the oxidation behavior of nuclear graphite, weight loss curve is usually measured through Thermo Gravimetric Analysis (TGA) method. In this work, three brands of nuclear graphite for HTGR (i.e., HSM-SC, IG-11, and NBG-18) are oxidized under 873 and 1073 K in open air, and their weight loss curves are obtained. The acceleration of oxidizing rate is observed for both HSM-SC and IG-11, and is attributed to the large porosity increase during oxidation process. For HSM-SC, the porosity increase comes from preferential binder oxidation, and thus its binder quality shall be improved to obtain better oxidation resistance. Temperature effects on oxidation for HSM-SC are also studied, which shows that oxidizing gas tends to be exhausted at graphite surface at high temperature instead of penetrate into the interior of bulk. (author)

Effect of surface oxidation on thermomechanical behavior of NiTi shape memory alloy wire

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Ng, Ching Wei; Mahmud, Abdus Samad

2017-12-01

Nickel titanium (NiTi) alloy is a unique alloy that exhibits special behavior that recovers fully its shape after being deformed to beyond elastic region. However, this alloy is sensitive to any changes of its composition and introduction of inclusion in its matrix. Heat treatment of NiTi shape memory alloy to above 600 °C leads to the formation of the titanium oxide (TiO2) layer. Titanium oxide is a ceramic material that does not exhibit shape memory behaviors and possess different mechanical properties than that of NiTi alloy, thus disturbs the shape memory behavior of the alloy. In this work, the effect of formation of TiO2 surface oxide layer towards the thermal phase transformation and stress-induced deformation behaviors of the NiTi alloy were studied. The NiTi wire with composition of Ti-50.6 at% Ni was subjected to thermal oxidation at 600 °C to 900 °C for 30 and 60 minutes. The formation of the surface oxide layers was characterized by using the Scanning Electron Microscope (SEM). The effect of surface oxide layers with different thickness towards the thermal phase transformation behavior was studied by using the Differential Scanning Calorimeter (DSC). The effect of surface oxidation towards the stress-induced deformation behavior was studied through the tensile deformation test. The stress-induced deformation behavior and the shape memory recovery of the NiTi wire under tensile deformation were found to be affected marginally by the formation of thick TiO2 layer.

The effects of the mode of delivery on oxidative-antioxidative balance.

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Mutlu, Birgul; Aksoy, Nurten; Cakir, Hale; Celik, Hakim; Erel, Ozcan

2011-11-01

The purpose of this study was to investigate the effects of the mode of delivery on the oxidant and antioxidant systems in mothers and infants and to demonstrate which mode leads more oxidative stress. The participants were divided into two groups according to the mode of their labour and delivery: group 1 (n = 33) women with normal labour and delivery and group 2 (n = 33) with scheduled caesarean section (C/S) and delivery. The maternal, cord, and infant blood samples in both groups were collected. The serum total antioxidant capacity (TAC) and the total oxidant status (TOS) were evaluated by using an automated colorimetric measurement method. The parameters indicating oxidative stress (TOS, oxidative stress index, and lipid hydroperoxide) in maternal, cord, and newborn blood samples were higher in patients delivering with C/S than those normal spontaneous vaginal deliveries (NSVD) patient group, while it was vice versa for TAC. It may be concluded that both the mothers and neonates in C/S group are exposed to higher oxidative stress as compared with those in NSVD group and the antioxidant mechanisms are insufficient to cope with this stress during C/S. This result indicates that the normal delivery through the physiological route is healthier for the bodies of mothers and infants.

Statistical Study of the Effects of the Composition on the Oxidation Resistance of Ni-Based Superalloys

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Si-Jun Park

2015-01-01

Full Text Available The effects of alloying elements (Co, Cr, Mo, W, Al, Ti, and Ta on the oxidation resistance of Ni-based superalloys are studied using the Response Surface Methodology (RSM. The statistical analysis showed that Al and Ta generally improve the oxidation resistance of the alloy, whereas Ti and Mo degrade the oxidation resistance. Co, Cr, and W did not alter oxidation rate significantly when examined by the mass gain averaged for all model alloys. However, it is remarkable that the degree of the effects of alloying elements varied with the concentration of other elements. Further, the effect of each element was sometimes found to be reversed for alloy groups specified by the concentration of another element.

Total-ionizing-dose effects on isolation oxides in modern CMOS technologies

International Nuclear Information System (INIS)

Barnaby, Hugh J.; Mclain, Michael; Esqueda, Ivan Sanchez

2007-01-01

This paper presents experimental data on the total dose response of deep sub-micron bulk CMOS devices and integrated circuits. Ionizing radiation experiments on shallow trench isolation (STI) field oxide MOS capacitors (FOXCAP) indicate a characteristic build-up of radiation-induced defects in the dielectric. In this paper, capacitors fabricated with STI, thermal, SIMOX and bipolar base oxides of similar thickness are compared and show the STI oxide to be most susceptible to radiation effects. Experimental data on irradiated shift registers and n-channel MOSFETs are also presented. These data indicate that radiation damage to the STI can increase the off-state current of n-channel devices and the standby current of CMOS integrated circuits

Newly designed PdRuBi/N-Graphene catalysts with synergistic effects for enhanced ethylene glycol electro-oxidation

International Nuclear Information System (INIS)

Li, Tengfei; Huang, Yiyin; Ding, Kui; Wu, Peng; Abbas, Syed Comail; Ghausi, Muhammad Arsalan; Zhang, Teng; Wang, Yaobing

2016-01-01

Graphical abstract: We rationally design and synthesize a ternary PdRuBi/NG catalyst with significantly enhanced catalytic activity with synergetic effect of Ru and Bi towards ethylene glycol electro-oxidation. - Abstract: Palladium (Pd)-based catalysts are appealing electro-catalysts for alcohol oxidation reaction in fuel cell, but still not efficient as the complicated oxidation process and sluggish kinetic. Here we rationally design and synthesize a PdRuBi/NG tri-metallic catalyst with space synergetic effect for enhanced ethylene glycol electro-oxidation, in which both Ru and Bi in the catalyst are synergistic effective in promoting catalytic activity of Pd catalytic interlayer by electronic effect and surface modification mechanism respectively. It shows 4.2 times higher peak current density towards ethylene glycol electro-oxidation than commercial Pd/C catalyst, and the catalytic durability is also greatly improved.

An Abnormal Nitric Oxide Metabolism Contributes to Brain Oxidative Stress in the Mouse Model for the Fragile X Syndrome, a Possible Role in Intellectual Disability

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Lima-Cabello, Elena; Garcia-Guirado, Francisco; Calvo-Medina, Rocio; el Bekay, Rajaa; Perez-Costillas, Lucia; Quintero-Navarro, Carolina; Sanchez-Salido, Lourdes

2016-01-01

Background. Fragile X syndrome is the most common genetic cause of mental disability. Although many research has been performed, the mechanism underlying the pathogenesis is unclear and needs further investigation. Oxidative stress played major roles in the syndrome. The aim was to investigate the nitric oxide metabolism, protein nitration level, the expression of NOS isoforms, and furthermore the activation of the nuclear factor NF-κB-p65 subunit in different brain areas on the fragile X mouse model. Methods. This study involved adult male Fmr1-knockout and wild-type mice as controls. We detected nitric oxide metabolism and the activation of the nuclear factor NF-κBp65 subunit, comparing the mRNA expression and protein content of the three NOS isoforms in different brain areas. Results. Fmr1-KO mice showed an abnormal nitric oxide metabolism and increased levels of protein tyrosine nitrosylation. Besides that, nuclear factor NF-κB-p65 and inducible nitric oxide synthase appeared significantly increased in the Fmr1-knockout mice. mRNA and protein levels of the neuronal nitric oxide synthase appeared significantly decreased in the knockout mice. However, the epithelial nitric oxide synthase isoform displayed no significant changes. Conclusions. These data suggest the potential involvement of an abnormal nitric oxide metabolism in the pathogenesis of the fragile X syndrome. PMID:26788253

An Abnormal Nitric Oxide Metabolism Contributes to Brain Oxidative Stress in the Mouse Model for the Fragile X Syndrome, a Possible Role in Intellectual Disability

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Elena Lima-Cabello

2016-01-01

Full Text Available Background. Fragile X syndrome is the most common genetic cause of mental disability. Although many research has been performed, the mechanism underlying the pathogenesis is unclear and needs further investigation. Oxidative stress played major roles in the syndrome. The aim was to investigate the nitric oxide metabolism, protein nitration level, the expression of NOS isoforms, and furthermore the activation of the nuclear factor NF-κB-p65 subunit in different brain areas on the fragile X mouse model. Methods. This study involved adult male Fmr1-knockout and wild-type mice as controls. We detected nitric oxide metabolism and the activation of the nuclear factor NF-κBp65 subunit, comparing the mRNA expression and protein content of the three NOS isoforms in different brain areas. Results. Fmr1-KO mice showed an abnormal nitric oxide metabolism and increased levels of protein tyrosine nitrosylation. Besides that, nuclear factor NF-κB-p65 and inducible nitric oxide synthase appeared significantly increased in the Fmr1-knockout mice. mRNA and protein levels of the neuronal nitric oxide synthase appeared significantly decreased in the knockout mice. However, the epithelial nitric oxide synthase isoform displayed no significant changes. Conclusions. These data suggest the potential involvement of an abnormal nitric oxide metabolism in the pathogenesis of the fragile X syndrome.

Involvement of oxidative stress in SAMP10 mice with age-related neurodegeneration.

Science.gov (United States)

Wang, Jun; Lei, Hongtao; Hou, Jincai; Liu, Jianxun

2015-05-01

Age-related changes in the brain tissue are reflected in many aspects. We sought to determine the morphology, Nissl bodies, behavioral appearance and oxidative stress in the brain using SAMP10 mice, a substrain of the senescence-accelerated mouse. SAMP10 mice groups divided by different ages (3, 5, 8 and 14 months) were compared with those of control groups with the above corresponding ages. Cortical thickness, Nissl bodies, behavioral appearance and oxidative stress were evaluated through image software, thionine staining, step-down test and colorimetry, respectively. The weight and cortical thickness of the brain in SAMP10 mice significantly reduced from 8 months of age. The results showed that the number of Nissl bodies decreased or Nissl bodies shrank with dark staining in histology. The same result appeared in a step-down test. As the SAMP10 mice grew older, the oxidative stress-related markers superoxide dismutase decreased and malondialdehyde increased after 8 months. Glutathione peroxidase activities showed no age-related changes. The changes of brain morphology and productions of oxidative stress in the brain tissue might contribute to the behavioral abnormality. Deceleration of age-related production of oxidative stress might be expected to be a potent strategy for anti-aging interventions.

Effects of gamma irradiation in graphene/poly (ethylene oxide) nanocomposites

International Nuclear Information System (INIS)

Braz, Elton P.; Goncalves, Natercia Antunes; Araujo, Patricia L.B.; Araujo, Elmo S.

2013-01-01

Nanotechnology is the understanding and control of matter in dimensions between 1 and 100nm. In such small matter portions, improved or even new properties may arise, as a direct consequence of reduced size. Thus, the development of multifunctional nanomaterials is nowadays one of the main goals of the materials research field. In this context, we produced graphene sheets through ultrasound exfoliation of graphite oxide, followed by chemical reduction. Composite nanofibers of these graphene sheets with biocompatible polymer poly (ethylene oxide) (PEO) were obtained by electrospinning technique, and irradiated up to 75kGy dose to assess the effects of gamma irradiation in the molecular structure of these composite nanomaterial. Our findings showed that PEO is quite resistant to radiation damage and that the incorporation of graphene oxide has no significant influence on its radiostability. (author)

Nanostructure-Directed Chemical Sensing: The IHSAB Principle and the Effect of Nitrogen and Sulfur Functionalization on Metal Oxide Decorated Interface Response

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James L. Gole

2013-08-01

Full Text Available The response matrix, as metal oxide nanostructure decorated n-type semiconductor interfaces are modified in situ through direct amination and through treatment with organic sulfides and thiols, is demonstrated. Nanostructured TiO2, SnOx, NiO and CuxO (x = 1,2, in order of decreasing Lewis acidity, are deposited to a porous silicon interface to direct a dominant electron transduction process for reversible chemical sensing in the absence of significant chemical bond formation. The metal oxide sensing sites can be modified to decrease their Lewis acidity in a process appearing to substitute nitrogen or sulfur, providing a weak interaction to form the oxynitrides and oxysulfides. Treatment with triethylamine and diethyl sulfide decreases the Lewis acidity of the metal oxide sites. Treatment with acidic ethane thiol modifies the sensor response in an opposite sense, suggesting that there are thiol (SH groups present on the surface that provide a Brønsted acidity to the surface. The in situ modification of the metal oxides deposited to the interface changes the reversible interaction with the analytes, NH3 and NO. The observed change for either the more basic oxynitrides or oxysulfides or the apparent Brønsted acid sites produced from the interaction of the thiols do not represent a simple increase in surface basicity or acidity, but appear to involve a change in molecular electronic structure, which is well explained using the recently developed inverse hard and soft acids and bases (IHSAB model.

Comparison of oral midazolam with a combination of oral midazolam and nitrous oxide-oxygen inhalation in the effectiveness of dental sedation for young children

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Al-Zahrani A

2009-03-01

Full Text Available Aim: To compare the effectiveness of 0.6 mg/kg oral midazolam sedation alone and a combination of 0.6 mg/kg oral midazolam plus nitrous oxide-oxygen inhalation sedation, in controlling the behavior of uncooperative children during dental treatment. Study Design: The study had a crossover design where the same patient received two different sedation regimens, that is, oral midazolam 0.6 mg/kg and oral midazolam 0.6 mg/kg with nitrous oxide-oxygen inhalation during two dental treatment visits. Materials and Methods: Thirty children (17 males and 13 females were randomly selected for the study, with a mean age of 55.07 (± 9.29 months, ranging from 48 - 72 months. A scoring system suggested by Houpt et al. (1985 was utilized for assessment of the children′s behavior. Results : There was no significant (p > 0.05 difference in the overall behavior assessment between the two sedation regimens, that is, oral midazolam alone and oral midazolam plus nitrous oxide-oxygen. However, the combination of midazolam and nitrous oxide-oxygen showed significantly (p < 0.05 superior results as compared to midazolam alone, in terms of controlling movement and crying during local anesthesia administration and restorative procedures. Conclusion: Compared to oral midazolam alone, a combination of oral midazolam and nitrous oxide inhalation sedation appears to provide more comfort to pediatric dental patients and operators during critical stages of dental treatment.

Effects of irradiation on color and lipid oxidation of prosciutto

International Nuclear Information System (INIS)

Kong Qiulian; Qi Wenyuan; Yue Ling; Chen Zhijun; Bao Yingzi; Dai Xudong; Xu Yun

2012-01-01

This study dealt with the effect of irradiation on the color, irradiation odor and lipid oxidation of prosciutto crudo. The hams were irradiated by γ-ray and electronic beam (EB). Changes of color, irradiation odor, TBA value (TBARS), peroxide value (POV), carbonyl value and conjugated diene value were analyzed and compared with non-irradiated hams. Results showed that color index (a * ) of control, γ-ray irradiated and EB irradiated were 14.39, 9.45 and 11.71 respectively. The ratios of a * /b * were different with the type of rays. The ratio of a * /b * of EB irradiation was same with control, while that of γ-ray irradiation was decreased apparently. γ-ray irradiation had been shown to have apparently detrimental effect on the color and odor of hams, while EB irradiation had little detrimental effect. Irradiation increased POV and conjugated diene value, but the amounts of lipid oxidation products (TBARS, carbonyl value) were less than nonirradiated hams. (authors)

Effect of active zinc oxide dispersion on reduced graphite oxide for hydrogen sulfide adsorption at mid-temperature

Science.gov (United States)

Song, Hoon Sub; Park, Moon Gyu; Croiset, Eric; Chen, Zhongwei; Nam, Sung Chan; Ryu, Ho-Jung; Yi, Kwang Bok

2013-09-01

Composites of Zinc oxide (ZnO) with reduced graphite oxide (rGO) were synthesized and used as adsorbents for hydrogen sulfide (H2S) at 300 °C. Various characterization methods (TGA, XRD, FT-IR, TEM and XPS) were performed in order to link their H2S adsorption performance to the properties of the adsorbent's surface. Microwave-assisted reduction process of graphite oxide (GO) provided mild reduction environment, allowing oxygen-containing functional groups to remain on the rGO surface. It was confirmed that for the ZnO/rGO synthesize using the microwave-assisted reduction method, the ZnO particle size and the degree of ZnO dispersion remained stable over time at 300 °C, which was not the case for only the ZnO particles themselves. This stable highly dispersed feature allows for sustained high surface area over time. This was confirmed through breakthrough experiments for H2S adsorption where it was found that the ZnO/rGO composite showed almost four times higher ZnO utilization efficiency than ZnO itself. The effect of the H2 and CO2 on H2S adsorption was also investigated. The presence of hydrogen in the H2S stream had a positive effect on the removal of H2S since it allows a reducing environment for Znsbnd O and Znsbnd S bonds, leading to more active sites (Zn2+) to sulfur molecules. On the other hand, the presence of carbon dioxide (CO2) showed the opposite trend, likely due to the oxidation environment and also due to possible competitive adsorption between H2S and CO2.

Effect of active zinc oxide dispersion on reduced graphite oxide for hydrogen sulfide adsorption at mid-temperature

International Nuclear Information System (INIS)

Song, Hoon Sub; Park, Moon Gyu; Croiset, Eric; Chen, Zhongwei; Nam, Sung Chan; Ryu, Ho-Jung; Yi, Kwang Bok

2013-01-01

Composites of Zinc oxide (ZnO) with reduced graphite oxide (rGO) were synthesized and used as adsorbents for hydrogen sulfide (H 2 S) at 300 °C. Various characterization methods (TGA, XRD, FT-IR, TEM and XPS) were performed in order to link their H 2 S adsorption performance to the properties of the adsorbent's surface. Microwave-assisted reduction process of graphite oxide (GO) provided mild reduction environment, allowing oxygen-containing functional groups to remain on the rGO surface. It was confirmed that for the ZnO/rGO synthesize using the microwave-assisted reduction method, the ZnO particle size and the degree of ZnO dispersion remained stable over time at 300 °C, which was not the case for only the ZnO particles themselves. This stable highly dispersed feature allows for sustained high surface area over time. This was confirmed through breakthrough experiments for H 2 S adsorption where it was found that the ZnO/rGO composite showed almost four times higher ZnO utilization efficiency than ZnO itself. The effect of the H 2 and CO 2 on H 2 S adsorption was also investigated. The presence of hydrogen in the H 2 S stream had a positive effect on the removal of H 2 S since it allows a reducing environment for Zn-O and Zn-S bonds, leading to more active sites (Zn 2+ ) to sulfur molecules. On the other hand, the presence of carbon dioxide (CO 2 ) showed the opposite trend, likely due to the oxidation environment and also due to possible competitive adsorption between H 2 S and CO 2 .

A DMS kinetic study of the boron oxides vapor in the combustion front of SHS system Mo + B

International Nuclear Information System (INIS)

Kashireninov, O.E.; Yuranov, I.A.

1994-01-01

The distribution of the boron oxides vapor in the combustion wave of the SHS system Mo + B has been studied by the dynamic mass spectrometry technique (DMS) to test the thermodynamically based hypothesis for the key role of gas-phase transport in solid-state combustion. The molecular beam sampling of the gases over the burning tablet was performed by a stationary probe cone from the moving combustion wave. Ion currents of boron oxides were recorded at 10--20 ms intervals that afforded spatial resolution of 0.1--0.2 mm. It has been found that the distribution of the boron oxides vapor pressure along the combustion wave corresponds to the known zones of preheating, reaction, and postcombustion. The rapid increase of B 2 O 2 pressure takes place in the preheating zone as a result of the reaction B(s) + B 2 O 3 (g) = B 2 O 2 (g). Boron oxides are not observed over the reaction zone because of their complete decay in the reaction with Mo(s) to form molybdenum boride(s). The appearance The appearance of boron oxide vapors over the postcombustion zone is due to the evaporation of B 2 O 3 (l). The effective kinetic parameters are estimated from the data obtained. The results show that solid-state combustion of the Mo + B system proceeds predominantly through formation of gas-phase boron oxides

Effects of a sexy appearance on perceived competence of women.

Science.gov (United States)

Wookey, Melissa L; Graves, Nell A; Butler, J Corey

2009-02-01

The present study replicates P. Glick, S. Larsen, C. Johnson, and H. Branstiter's (2005) previous research showing that a sexy appearance may be detrimental to women in high-status jobs. The authors used a larger sample and different stimulus materials and evaluation measures. As in the original experiment, participants rated sexually and professionally dressed women in both low- and high-status positions on perceived ability. The results were consistent with the original study and showed that high-status, sexually dressed women receive lower ratings in competence.

Comparison Between the Acute Pulmonary Vascular Effects of Oxygen with Nitric Oxide and Sildenafil

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Ronald W. Day

2015-03-01

Full Text Available Objective. Right heart catheterization is performed in patients with pulmonary arterial hypertension to determine the severity of disease and their pulmonary vascular reactivity. The acute pulmonary vascular effect of inhaled nitric oxide is frequently used to identify patients who will respond favorably to vasodilator therapy. This study sought to determine whether the acute pulmonary vascular effects of oxygen with nitric oxide and intravenous sildenafil are similar. Methods. A retrospective, descriptive study of 13 individuals with pulmonary hypertension who underwent heart catheterization and acute vasodilator testing was performed. The hemodynamic measurements during five phases (21% to 53% oxygen, 100% oxygen, 100% oxygen with 20 ppm nitric oxide, 21% to 51% oxygen, and 21% to 51% oxygen with 0.05 mg/kg to 0.29 mg/kg intravenous sildenafil of the procedures were compared.Results. Mean pulmonary arterial pressure and pulmonary vascular resistance acutely decreased with 100% oxygen with nitric oxide, and 21% to 51% oxygen with sildenafil. Mean pulmonary arterial pressure (mm Hg, mean ± standard error of the mean was 38 ± 4 during 21% to 53% oxygen, 32 ± 3 during 100% oxygen, 29 ± 2 during 100% oxygen with nitric oxide, 37 ± 3 during 21% to 51% oxygen, and 32 ± 2 during 21% to 51% oxygen with sildenafil. There was not a significant correlation between the percent change in pulmonary vascular resistance from baseline with oxygen and nitric oxide, and from baseline with sildenafil (r2 = 0.011, p = 0.738. Conclusions. Oxygen with nitric oxide and sildenafil decreased pulmonary vascular resistance. However, the pulmonary vascular effects of oxygen and nitric oxide cannot be used to predict the acute response to sildenafil. Additional studies are needed to determine whether the acute response to sildenafil can be used to predict the long-term response to treatment with an oral phosphodiesterase V inhibitor.

Effects of curcumin on angiotensin-converting enzyme gene expression, oxidative stress and anti-oxidant status in thioacetamide-induced hepatotoxicity.

Science.gov (United States)

Fazal, Yumna; Fatima, Syeda Nuzhat; Shahid, Syed Muhammad; Mahboob, Tabassum

2015-12-01

This study aimed to evaluate the protective effects of curcumin on angiotensin-converting enzyme (ACE) gene expression, oxidative stress and anti-oxidant status in thioacetamide (TAA)-induced hepatotoxicity in rats. Total 32 albino Wistar rats (male, 200-250 g) were divided into six groups (n=8). Group 1: untreated controls; Group 2: received TAA (200 mg/kg body weight (b.w.); i.p.) for 12 weeks; Group 3: received curcumin (75 mg/kg b.w.) for 24 weeks; Group 4: received TAA (200 mg/kg b.w.; i.p.) for 12 weeks+curcumin (75 mg/kg b.w.) for 12 weeks. A significantly higher ACE gene expression was observed in TAA-induced groups as compared with control, indicating more synthesis of ACE proteins. Treatment with curcumin suppressed ACE expression in TAA liver and reversed the toxicity produced. TAA treatment results in higher lipid peroxidation and lower GSH, SOD and CAT than the normal, and this produces oxidative stress in the liver. Cirrhotic conditions were confirmed by serum enzymes (ALT, AST and ALP) as well as histopathological observations. Curcumin treatment reduced oxidative stress in animals by scavenging reactive oxygen species, protecting the anti-oxidant enzymes from being denatured and reducing the oxidative stress marker lipid peroxidation. Curcumin treatment restores hepatocytes, damaged by TAA, and protects liver tissue approaching cirrhosis. © The Author(s) 2014.

Effect of acid on the aggregation of poly(ethylene xide)-poly(propylene oxide)-poly(ethylene oxide) block copolymers.

Science.gov (United States)

Yang, Bin; Guo, Chen; Chen, Shu; Ma, Junhe; Wang, Jing; Liang, Xiangfeng; Zheng, Lily; Liu, Huizhou

2006-11-23

The acid effect on the aggregation of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymers EO(20)PO(70)EO(20) has been investigated by transmission electron microscopy (TEM), particle size analyzer (PSA), Fourier transformed infrared, and fluorescence spectroscopy. The critical micellization temperature for Pluronic P123 in different HCl aqueous solutions increases with the increase of acid concentration. Additionally, the hydrolysis degradation of PEO blocks is observed in strong acid concentrations at higher temperatures. When the acid concentration is low, TEM and PSA show the increase of the micelle mean diameter and the decrease of the micelle polydispersity at room temperature, which demonstrate the extension of EO corona and tendency of uniform micelle size because of the charge repulsion. When under strong acid conditions, the aggregation of micelles through the protonated water bridges was observed.

The effects of Bifidobacteria on the lipid profile and oxidative stress biomarkers of male rats fed thermally oxidized soybean oil.

Science.gov (United States)

Awney, Hala A

2011-08-01

Over the years, there has been concern about the changes taking place in heated oils and the effects on individuals consuming them. The present study investigated the effects of a diet containing thermally oxidized soybean oil (TO) or TO supplemented with probiotic Bifidobacteria (TO+Pro) on the serum lipid profile and oxidative stress biomarkers of male rats. The data showed several indicators of oil deterioration after thermal processing, including high levels of % free fatty acid (FFA; 15-fold), acid value (AV; 14-fold), peroxide value (8-fold), p-anisidine value (AnV; 39-fold), total oxidation value (TOTOX; 19-fold), thiobarbituric acid-reactive substances (TBARS) value (8.5-fold), and trans-FA (TFA) isomers (2.5-fold) compared to the control. The rats that were fed a diet containing TO showed a significant (p blood serum samples. High levels of TBARS, superoxide dismutase (SOD), and glutathione reductase (GR) activities were also detected in the livers, kidneys, testes, and brains of rats. Interestingly, a diet containing TO+Pro restored all biological parameters to their control values. The present data suggested that Bifidobacteria may ameliorate the serum lipid profile and oxidative stress biomarkers that are generated in animals that are fed a TO diet.

Alleviating effect of exogenous nitric oxide in cucumber seedling ...

African Journals Online (AJOL)

Administrator

2011-05-23

May 23, 2011 ... oxidation (Shi et al., 2007). To protect cells and organelles from the damaging effects of ROS, complex antioxidant defense system have been evolved which comprises of enzymes such as superoxide dismutase (SOD), catalase. (CAT), peroxidase (POD) and glutathione reeducate (GR). (Lee et al., 2000; ...

A comparative study of silver-graphene oxide nanocomposites as a recyclable catalyst for the aerobic oxidation of benzyl alcohol: Support effect

Energy Technology Data Exchange (ETDEWEB)

Zahed, Bahareh; Hosseini-Monfared, Hassan, E-mail: monfared@znu.ac.ir

2015-02-15

Graphical abstract: - Highlights: • Characteristics of three different graphene oxide (GO) are studied as a support for Ag nanoparticles. • The required conditions for a best support are determined. • For the first time the silver nanoparticles decorated GO as catalyst for aerobic oxidation of benzyl alcohol and the effects of the degree of reduction of GO on AgNPs on GO are reported. - Abstract: Three different nanocomposites of silver and graphene oxide, namely silver nanoparticles (AgNPs) immobilized on reduced graphene oxide (AgNPs/rGO), partially reduced graphene oxide (AgNPs/GO) and thiolated partially reduced graphene oxide (AgNPs/GOSH), were synthesized in order to compare their properties. Characterizations were carried out by infrared and UV–Vis and Raman spectroscopy, ICP, X-ray diffraction, SEM and TEM, confirming both the targeted chemical modification and the composite formation. The nanocomposites were successfully employed in the aerobic oxidation of benzyl alcohol at atmospheric pressure. AgNPs/GOSH is stable and recyclable catalyst which showed the highest activity in the aerobic oxidation of benzyl alcohol in the presence of N-hydroxyphthalimide (NHPI) to give benzaldehyde with 58% selectivity in 24 h at 61% conversion. The favorite properties of AgNPs/GOSH are reasonably attributed to the stable and well distributed AgNPs over GOSH due to strong adhesion between AgNPs and GOSH.

Maltol, a Food Flavoring Agent, Attenuates Acute Alcohol-Induced Oxidative Damage in Mice

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Ye Han

2015-01-01

Full Text Available The purpose of this study was to evaluate the hepatoprotective effect of maltol, a food-flavoring agent, on alcohol-induced acute oxidative damage in mice. Maltol used in this study was isolated from red ginseng (Panax ginseng C.A Meyer and analyzed by high performance liquid chromatography (HPLC and mass spectrometry. For hepatoprotective activity in vivo, pretreatment with maltol (12.5, 25 and 50 mg/kg; 15 days drastically prevented the elevated activities of aspartate transaminase (AST, alanine transaminase (ALT, alkaline phosphatase (ALP and triglyceride (TG in serum and the levels of malondialdehyde (MDA, tumor necrosis factor-α (TNF-α, interleukin-1β (IL-1β in liver tissue (p < 0.05. Meanwhile, the levels of hepatic antioxidant, such as catalase (CAT, superoxide dismutase (SOD, glutathione peroxidase (GSH-Px were elevated by maltol pretreatment, compared to the alcohol group (p < 0.05. Histopathological examination revealed that maltol pretreatment significantly inhibited alcohol-induced hepatocyte apoptosis and fatty degeneration. Interestingly, pretreatment of maltol effectively relieved alcohol-induced oxidative damage in a dose-dependent manner. Maltol appeared to possess promising anti-oxidative and anti-inflammatory capacities. It was suggested that the hepatoprotective effect exhibited by maltol on alcohol-induced liver oxidative injury may be due to its potent antioxidant properties.

Emotion and anxiety potentiate the way attention alters visual appearance.

Science.gov (United States)

Barbot, Antoine; Carrasco, Marisa

2018-04-12

The ability to swiftly detect and prioritize the processing of relevant information around us is critical for the way we interact with our environment. Selective attention is a key mechanism that serves this purpose, improving performance in numerous visual tasks. Reflexively attending to sudden information helps detect impeding threat or danger, a possible reason why emotion modulates the way selective attention affects perception. For instance, the sudden appearance of a fearful face potentiates the effects of exogenous (involuntary, stimulus-driven) attention on performance. Internal states such as trait anxiety can also modulate the impact of attention on early visual processing. However, attention does not only improve performance; it also alters the way visual information appears to us, e.g. by enhancing perceived contrast. Here we show that emotion potentiates the effects of exogenous attention on both performance and perceived contrast. Moreover, we found that trait anxiety mediates these effects, with stronger influences of attention and emotion in anxious observers. Finally, changes in performance and appearance correlated with each other, likely reflecting common attentional modulations. Altogether, our findings show that emotion and anxiety interact with selective attention to truly alter how we see.

Low Temperature Processed Complementary Metal Oxide Semiconductor (CMOS) Device by Oxidation Effect from Capping Layer

KAUST Repository

Wang, Zhenwei

2015-04-20

In this report, both p- and n-type tin oxide thin-film transistors (TFTs) were simultaneously achieved using single-step deposition of the tin oxide channel layer. The tuning of charge carrier polarity in the tin oxide channel is achieved by selectively depositing a copper oxide capping layer on top of tin oxide, which serves as an oxygen source, providing additional oxygen to form an n-type tin dioxide phase. The oxidation process can be realized by annealing at temperature as low as 190°C in air, which is significantly lower than the temperature generally required to form tin dioxide. Based on this approach, CMOS inverters based entirely on tin oxide TFTs were fabricated. Our method provides a solution to lower the process temperature for tin dioxide phase, which facilitates the application of this transparent oxide semiconductor in emerging electronic devices field.

The effect of consuming oxidized oil supplemented with fiber on lipid profiles in rat model

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Shila Shafaeizadeh

2011-01-01

Conclusions: Pectin consumption could decrease serum malondialdehyde and cholesterol in the diet that contains oxidized oil. Pectin supplementation could decrease the detrimental effects of thermally oxidized oil.

Neuroprotective effects of ganoderma lucidum polysaccharides against oxidative stress-induced neuronal apoptosis

Science.gov (United States)

Sun, Xin-zhi; Liao, Ying; Li, Wei; Guo, Li-mei

2017-01-01

Ganoderma lucidum polysaccharides have protective effects against apoptosis in neurons exposed to ischemia/reperfusion injury, but the mechanisms are unclear. The goal of this study was to investigate the underlying mechanisms of the effects of ganoderma lucidum polysaccharides against oxidative stress-induced neuronal apoptosis. Hydrogen peroxide (H2O2) was used to induce apoptosis in cultured cerebellar granule cells. In these cells, ganoderma lucidum polysaccharides remarkably suppressed H2O2-induced apoptosis, decreased expression of caspase-3, Bax and Bim and increased that of Bcl-2. These findings suggested that ganoderma lucidum polysaccharides regulate expression of apoptosis-associated proteins, inhibit oxidative stress-induced neuronal apoptosis and, therefore, have significant neuroprotective effects. PMID:28761429

Punica granatum juice effects on oxidative stress in severe physical activity.

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Naghizadeh-Baghi, Abbas; Mazani, Mohammad; Shadman-Fard, Ali; Nemati, Ali

2015-02-01

The aim of this study was to investigate Punica granatum juice effects on oxidative stress in young healthy males during severe physical activity. Our subjects were selected from healthy males at 18 - 24 years. They were enrolled and randomly distributed into control and supplemented groups. 240 ml of Punica granatum juice and tap water were given to supplement and control groups daily for two weeks, respectively. Fasting blood samples were taken at the starting and the end of two weeks of intervention. Subjects were given once severe physical activity and then fasting blood samples were taken. Fasting blood samples were used for testing of oxidative and antioxidative factors. Data were analyzed using descriptive statistical tests, paired samples t-test, and independent samples t-test. The levels of arylesterase, superoxide dismutase, glutathione peroxidase and total antioxidant capacity after severe physical activity in supplement group were significantly increased (pPunica granatum juice significantly modulates oxidative stress and thus protects against severe physical activity oxidative injury in young healthy males.

Effects of selected metal oxide nanoparticles on Artemia salina larvae: evaluation of mortality and behavioural and biochemical responses.

Science.gov (United States)

Gambardella, Chiara; Mesarič, Tina; Milivojević, Tamara; Sepčić, Kristina; Gallus, Lorenzo; Carbone, Serena; Ferrando, Sara; Faimali, Marco

2014-07-01

The aim was to investigate the toxicity of selected metal oxide nanoparticles (MO-NPs) on the brine shrimp Artemia salina, by evaluating mortality and behavioural and biochemical responses. Larvae were exposed to tin(IV) oxide (stannic oxide (SnO2)), cerium(IV) oxide (CeO2) and iron(II, III) oxide (Fe3O4) NPs for 48 h in seawater, with MO-NP suspensions from 0.01 to 1.0 mg/mL. Mortality and behavioural responses (swimming speed alteration) and enzymatic activities of cholinesterase, glutathione-S-transferase and catalase were evaluated. Although the MO-NPs did not induce any mortality of the larvae, they caused changes in behavioural and biochemical responses. Swimming speed significantly decreased in larvae exposed to CeO2 NPs. Cholinesterase and glutathione-S-transferase activities were significantly inhibited in larvae exposed to SnO2 NPs, whereas cholinesterase activity significantly increased after CeO2 NP and Fe3O4 NP exposure. Catalase activity significantly increased in larvae exposed to Fe3O4 NPs. In conclusion, swimming alteration and cholinesterase activity represent valid endpoints for MO-NP exposure, while glutathione-S-transferase and catalase activities appear to be NP-specific.

The Effects of Oxidative Stress in Urinary Tract Infection

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Ergul Belge Kurutas

2005-01-01

Full Text Available We aimed to determine the effects of oxidative stress in urinary tract infection (UTI. One hundred sixty-four urine samples obtained from patients with the prediagnosis of acute UTI admitted to the Faculty of Medicine, Kahramanmaras Sutcu Imam University, were included in this study. Urine cultures were performed according to standard techniques. Urinary isolates were identified by using API ID 32E. The catalase and superoxide dismutase activity and the lipid peroxidation levels known as oxidative stress markers were measured in all urine samples. Thirty-six pathogen microorganisms were identified in positive urine cultures. These microorganisms were as follows: 23 (63.8% E coli, 5 (13.8% P mirabilis, 4 (11.1% K pneumoniae, 2 (5.5% Candida spp, 1 (2.7% S saprophyticus, and 1 (2.7% P aeruginosa. It was observed that lipid peroxidation levels were increased while catalase and superoxide dismutase activities were decreased in positive urine cultures, compared to negative cultures. We conclude that urinary tract infection causes oxidative stress, increases lipid peroxidation level, and leads to insufficiency of antioxidant enzymes.

The effects of female "Thin Ideal" media on men's appearance schema, cognitive performance, and self-evaluations: A self-determination theory approach.