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Sample records for plasma oxidative status

  1. The effect of quercetin on plasma oxidative status, C-reactive protein and blood pressure in women with rheumatoid arthritis

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    Fatemeh Javadi

    2014-01-01

    Conclusions: In this study, quercetin had no effect on oxidative and inflammatory status of plasma and blood pressure in patients with RA. Further studies are needed to ensure the effect of quercetin on oxidative stress and inflammation in human.

  2. Altered Antioxidant Status and Increased Lipid Per-Oxidation in Seminal Plasma of Tunisian Infertile Men

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    Atig, Fatma; Raffa, Monia; Ali, Habib Ben; Abdelhamid, Kerkeni; Saad, Ali; Ajina, Mounir

    2012-01-01

    Human seminal plasma is a natural reservoir of antioxidants that protect spermatozoa from oxidative damages. There is evidence in literature supports the fact that impairments in seminal antioxidant and lipid per-oxidation status play important roles in the physiopathology of male infertility. Our present study forms the first one which was carried out in Tunisia. We evaluated the antioxidant status in the seminal plasma of 120 infertile men programmed to In Vitro Fertilization (IVF) for the first tentative. Patients were characterized by an idiopathic infertility. They were divided into three groups: normozoospermics who were considered as controls (n=40), asthenozoospermics (Astheno; n=45) and oligoasthenoteratozoospermics (OAT; n=35). Seminal activities of superoxide dismutase (SOD) and glutathione peroxidase (GPX) and the levels of glutathione (GSH), zinc (Zn) and malondialdehyde (MDA) were measured. With the significant increase of the seminal activities of SOD and GPX in normozoospermics group, there were positive correlations observed between this enzymes and sperm quality. Also, significant elevated rates of seminal zinc and GSH were observed in control group, but there was contradictory associations reflecting the effects of these antioxidants on semen parameters. However, we noted significant increase of MDA levels in groups with abnormal seminogram. We showed negative associations between this per-oxidative marker and sperm parameters. These results obviously suggested that impairment on seminal antioxidants is an important risk factor for low sperm quality associated to idiopathic infertility and as a result can lead to poor IVF outcome. PMID:22211112

  3. Altered Antioxidant Status and Increased Lipid Per-Oxidation in Seminal Plasma of Tunisian Infertile Men

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    Fatma Atig, Monia Raffa, Habib Ben Ali, Kerkeni Abdelhamid, Ali Saad, Mounir Ajina

    2012-01-01

    Full Text Available Human seminal plasma is a natural reservoir of antioxidants that protect spermatozoa from oxidative damages. There is evidence in literature supports the fact that impairments in seminal antioxidant and lipid per-oxidation status play important roles in the physiopathology of male infertility. Our present study forms the first one which was carried out in Tunisia. We evaluated the antioxidant status in the seminal plasma of 120 infertile men programmed to In Vitro Fertilization (IVF for the first tentative. Patients were characterized by an idiopathic infertility. They were divided into three groups: normozoospermics who were considered as controls (n=40, asthenozoospermics (Astheno; n=45 and oligoasthenoteratozoospermics (OAT; n=35. Seminal activities of superoxide dismutase (SOD and glutathione peroxidase (GPX and the levels of glutathione (GSH, zinc (Zn and malondialdehyde (MDA were measured. With the significant increase of the seminal activities of SOD and GPX in normozoospermics group, there were positive correlations observed between this enzymes and sperm quality. Also, significant elevated rates of seminal zinc and GSH were observed in control group, but there was contradictory associations reflecting the effects of these antioxidants on semen parameters. However, we noted significant increase of MDA levels in groups with abnormal seminogram. We showed negative associations between this per-oxidative marker and sperm parameters. These results obviously suggested that impairment on seminal antioxidants is an important risk factor for low sperm quality associated to idiopathic infertility and as a result can lead to poor IVF outcome.

  4. Plasma paraoxonase, oxidative status level, and their relationship with asthma control test in children with asthma.

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    Emin, O; Hasan, A; Rusen, D M

    2015-01-01

    Assessment of asthma with a control test has been suggested as a relevant approach in recent years. However, no biomarker of systemic inflammation has been included in the assessment of asthma control. To evaluate plasma paraoxonase (PON1), total oxidant status (TOS), and total antioxidant status (TAS) levels in children with asthma according to the disease control, and the performance in the identification of uncontrolled patients. Stable asthmatic children (n=85) and healthy controls (n=55) were recruited for this study. Blood samples were collected for plasma PON1, TOS, and TAS measurements. Any contributing factors that may affect plasma PON1, TAS, and TOS levels were excluded from both groups. The diagnostic potential of these measures was evaluated using receiver operating characteristic (ROC) analysis. Comparing the asthmatic children with the control group, plasma TAS and TOS levels were significantly higher (TAS; 6.9 ± 2.1, 1.05 ± 0.32, Pasthma, respectively. Asthma Control Test (ACT) presented an AUC of 0.972 for the identification of uncontrolled asthma. PON1 and TOS levels may be systemic markers of uncontrolled asthma in children. Combined use of these two biomarkers with asthma control test may identify patients with uncontrolled asthma in children. Copyright © 2014 SEICAP. Published by Elsevier Espana. All rights reserved.

  5. Plasma nitrite levels, total antioxidant status, total oxidant status, and oxidative stress index in patients with tension-type headache and fibromyalgia.

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    Neyal, Munife; Yimenicioglu, Fatih; Aydeniz, Ali; Taskin, Abdullah; Saglam, Sadullah; Cekmen, Mustafa; Neyal, Abdurrahman; Gursoy, Savas; Erel, Ozcan; Balat, Ayse

    2013-06-01

    Tension-type headache (TTH) and fibromyalgia syndrome (FM) are worldwide seen chronic pain syndromes of unknown etiology. Despite the growing body of data on pathophysiology and generation mechanisms of pain; our knowledge on pain mechanisms in both FM and TTH is yet to be limited. We investigated the plasma nitrite levels, total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) in 35 TTH, 33 FM patients and 31 healthy controls. The mean plasma nitrite levels and TAS levels were significantly low and OSI was found to be significantly high in TTH and FM groups compared to the control group (p=0.001, p=0.001, p=0.001 and p=0.001, respectively). The mean serum TOS levels were also significantly higher in FM group according to the control group (p=0.034), but there was not a significant difference between TTH and control groups (p=0.066). These results indicated that; FM and TTH patients revealed higher oxidative stress index and lower total nitrite levels than healthy controls. We conclude that oxidative stress may have a role in the pathophysiological mechanisms of TTH and FM, although, whether it is the cause or the consequence, is not clear. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. The role of platelet and plasma markers of antioxidant status and oxidative stress in thrombocytopenia among patients with vivax malaria

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    Claudio F Araujo

    2008-09-01

    Full Text Available Malaria remains an important health problem in tropical countries like Brazil. Thrombocytopenia is the most common hematological disturbance seen in malarial infection. Oxidative stress (OS has been implicated as a possible mediator of thrombocytopenia in patients with malaria. This study aimed to investigate the role of OS in the thrombocytopenia of Plasmodium vivax malaria through the measurement of oxidant and antioxidant biochemical markers in plasma and in isolated platelets. Eighty-six patients with P. vivax malaria were enrolled. Blood samples were analyzed for total antioxidant and oxidant status, albumin, total protein, uric acid, zinc, magnesium, bilirubin, total thiols, glutathione peroxidase (GPx, malondialdehyde (MDA, antibodies against mildly oxidized low-density lipoproteins (LDL-/nLDL ratio and nitrite/nitrate levels in blood plasma and GPx and MDA in isolated platelets. Plasma MDA levels were higher in thrombocytopenic (TCP (median 3.47; range 1.55-12.90 µmol/L compared with the non-thrombocytopenic (NTCP patients (median 2.57; range 1.95-8.60 µmol/L. Moreover, the LDL-/nLDL autoantibody ratio was lower in TCP (median 3.0; range 1.5-14.8 than in NTCP patients (median 4.0; range 1.9-35.5. Finally, GPx and MDA were higher in the platelets of TPC patients. These results suggest that oxidative damage of platelets might be important in the pathogenesis of thrombocytopenia found in P. vivax malaria as indicated by alterations of GPx and MDA.

  7. Effects of acute and chronic heat stress on plasma metabolites, hormones and oxidant status in restrictedly fed broiler breeders.

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    Xie, Jingjing; Tang, Li; Lu, Lin; Zhang, Liyang; Lin, Xi; Liu, Hsiao-Ching; Odle, Jack; Luo, Xugang

    2015-07-01

    Heat tolerance can be improved by feed restriction in broiler chickens. It is unknown whether the same is true for broiler breeders, which are restrictedly fed. Therefore, the current study was conducted to study the effects of heat stress on plasma metabolites, hormones, and oxidative status of restricted fed broiler breeders with special emphases on the temperature and latency of heat exposure. In trial 1, 12 broiler breeders were kept either in a thermoneutral chamber (21°C, control, n = 6) or in a chamber with a step-wise increased environmental temperature from 21 to 33°C (21, 25, 29, 33°C, heat-stressed, n = 6). Changes in plasma total cholesterol, glucose, and triiodothyronine (T3) were closely related to the environmental temperature. When the temperature reached 29°C, plasma T3 (P stressed birds, whereas plasma glucose (P stressed birds than controls regardless of the temperatures applied. In Trial 2, 24 broiler breeders were divided into 2 groups and raised under 21°C and 32°C for 8 weeks, respectively. Total cholesterol was increased in chronic heat-stressed broiler breeders after 4 weeks. Plasma lactate dehydrogenase (LDH, P = 0.047) and glutamic-oxaloacetic transaminase (GOT, P = 0.036) was up-regulated after 6 weeks of thermal treatment, whereas plasma CK (P = 0.009) was increased at the end of thermal treatment. Plasma malonaldehyde, protein carbonyl content, activity of total superoxide dismutase (SOD), and corticosterone content were not altered after acute and prolonged heat challenges. Taken together, acute heat stress primarily resulted in disturbance of plasma metabolites, whereas chronic heat stress caused tissue damage reflected by increased plasma LDA, GOT, and CK. During acute heat stress, plasma metabolites were minimally disturbed in broiler breeders until the environmental temperature reached 33°C. © 2015 Poultry Science Association Inc.

  8. Status of plasma nitric oxide and non-enzymatic antioxidants before and after antipsychotic treatment in Nigerian patients with schizophrenia

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    Ganiyu Olatubosun Arinola

    2009-02-01

    Full Text Available

    • BACKGROUND: Recently, it is proposed that oxidant-antioxidant imbalance may have a role in the pathophysiology of schizophrenia. The present study was performed to assess differences in plasma levels of nitric oxide (as oxidant, caeruloplasmin (secondary antioxidant, and antioxidant trace metals (Zn, Se, Mn, Cu and Fe in patients with schizophrenia compared with healthy controls. Our secondary aim was to further evaluate the impact of psychopharmacologic treatment on these parameters.
    • METHODS: Plasma levels of nitric oxides (NO, caeruloplasmin, zinc (Zn, selenium (Se, manganese (Mn, copper (Cu and iron (Fe in patients with schizophrenia before (n = 15 and after antipsychotic drug treatment (n = 20 were compared with those of healthy controls (n = 20. Convenient sampling method was used for the selection of subjects. NO was estimated by the use of Griess method, caeruloplasmin was estimated by the use of immunodiffusion method and antioxidant trace metals was estimated by the use of atomic absorption spectrophotometer.
    • RESULTS: The levels of Cu and caeruloplasmin were not significantly different while Fe and Se were significantly reduced in both groups of schizophrenic patients compared with the controls. Zn was significantly elevated in medicated
    • schizophrenics compared with drug-free patients or controls. NO was significantly elevated in drug free patients with schizophrenia compared with controls or treated patients.
    • CONCLUSIONS: Our findings suggest the application of management strategies that will reduce NO but will increase antioxidant trace metals in patients with schizophrenia.
    • KEYWORDS: Schizophrenia, antioxidant defense system, antioxidant status, oxidative Stress.

  9. Plasma total oxidant and antioxidant status after oral glucose tolerance and mixed meal tests in patients with polycystic ovary syndrome.

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    Kucukaydın, Zehra; Duran, Cevdet; Basaran, Mustafa; Camlica, Fatos; Erdem, Sami Said; Basaran, Ahmet; Kutlu, Orkide; Burnik, Ferda Sevimli; Elmas, Halis; Gonen, Mustafa Sait

    2016-10-01

    Insulin resistance (IR) and increased oxidative stress (OS) are the characteristics of polycystic ovary syndrome (PCOS). In this study, we aimed to evaluate the effects of oral glucose tolerance (OGTT) and mixed meal tests (MMT) on plasma total oxidant (TOS) and total antioxidant status (TAS) in patients with PCOS and the relationship between these parameters and IR, calculated via homeostasis of model assessment-IR (HOMA-IR) and Matsuda's insulin sensitivity index (ISI) derived from OGTT and MMT. Twenty-two patients with PCOS, and age- and body mass index (BMI)-matched 20 women as controls were enrolled into the study. Five-hour OGTT and MMT were performed on different days, and before and after these tests, plasma TOS and TAS levels were investigated. IR was calculated with HOMA-IR and Matsuda's ISI. HOMA-IR levels were higher in patients with PCOS, compared to controls, while Matsuda's ISI derived from OGTT and MMT was higher in controls. Plasma TOS levels before OGTT and MMT were higher in patients with PCOS than controls, while TAS levels were similar. After OGTT, plasma TOS levels became decreased at 5th hour, when compared to baseline values in PCOS group. Likewise, the same decrement was found in controls, but the decrement was not significant. After OGTT and MMT at 5th hour, no changes were observed in TAS levels, compared to baseline. Matsuda's ISIs derived from OGTT and MMT can be used instead of each other, and interestingly, we found a decrease in TOS levels after OGTT in patients with PCOS.

  10. Association of plasma proteins at multiple stages of glycation and antioxidant status with erythrocyte oxidative stress in patients with type 2 diabetes.

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    Tupe, R S; Diwan, A G; Mittal, V D; Narayanam, P S; Mahajan, K B

    2014-01-01

    This study examines the individual stages of plasma protein glycation, antioxidant status and their association with erythrocyte oxidative stress in patients with type 2 diabetes mellitus (T2DM). Study was carried out on blood from 70 patients with T2DM and 40 healthy age- and gender-matched volunteers. Biomarkers of plasma protein glycation (fructosamine, protein carbonyls, advanced glycation end products [AGEs], amyloid), antioxidant status (thiols, total antioxidant capacity and erythrocyte oxidative parameters), osmotic fragility, lipid peroxidation (LPO), reduced glutathione (GSH) and catalase were determined. Plasma glycation markers were higher in T2DM patients than in healthy volunteers: fructosamine 578 vs. 525 micromol/mL; carbonyl 21.23 vs. 18.84 nmol/mg protein (P glycation markers, positive correlations were evident between fructosamine and amyloid (r = 0.350, P glycation markers showed negative correlation with plasma antioxidant status while positive correlation was demonstrated between erythrocytes fragility and AGEs and amyloid. Erythrocyte LPO levels correlated positively with amyloid. These data suggest that increased levels of multiple plasma protein glycation products in T2DM patients play a key role in reduced plasma antioxidant status and amplified erythrocyte oxidative damage.

  11. Present status of thin oxide films creation in a microwave plasma

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    Loncar, G. (Ceske Vysoke Uceni Technicke, Prague (Czechoslovakia). Fakulta Jaderna a Fysikalne Inzenyrska); Musil, J.; Bardos, L. (Ceskoslovenska Akademie Ved, Prague. Ustav Fyziky Plazmatu)

    1980-01-01

    The paper summarizes present knowledge of the creation of thin films in both isotropic and magnetoactive plasmas. It analyses conditions under which films in the microwave plasma can be created and shows how the growth rates and properties of films depend on microparameters of the plasma. On the basis of plasma floating potential measurements it is shown why the creation of thin films in microwave discharges takes place at high electron plasma densities (N > or approximately 10/sup 12/ cm/sup -3/) only. Besides, it describes properties of formed films, underlines the negative role of fast electrons in forming good quality films and gives recommendation of how to avoid their generation. Considerable attention is devoted also to a comparison of film creation in pulsed and continuous plasmas. The possibility of film creation at low temperatures by the deposition technique utilizing microwave excitation of molecular gases is given.

  12. Effect of sulfite treatment on total antioxidant capacity, total oxidant status, lipid hydroperoxide, and total free sulfydryl groups contents in normal and sulfite oxidase-deficient rat plasma.

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    Herken, Emine Nur; Kocamaz, Erdogan; Erel, Ozcan; Celik, Hakim; Kucukatay, Vural

    2009-08-01

    Sulfites, which are commonly used as preservatives, are continuously formed in the body during the metabolism of sulfur-containing amino acids. Sulfite oxidase (SOX) is an essential enzyme in the pathway of the oxidative degradation of sulfite to sulfate protecting cells from sulfite toxicity. This article investigated the effect of sulfite on total antioxidant capacity (TAC), total oxidant status, lipid hydroperoxide (LOOH), and total free sulfydryl groups (-SH) levels in normal and SOX-deficient male albino rat plasma. For this purpose, rats were divided into four groups: control, sulfite-treated, SOX-deficient, and sulfite-treated SOX-deficient groups. SOX deficiency was established by feeding rats a low molybdenum diet and adding to their drinking water 200 ppm tungsten. Sulfite (70 mg/kg) was administered to the animals via their drinking water. SOX deficiency together with sulfite treatment caused a significant increase in the plasma LOOH and total oxidant status levels. -SH content of rat plasma significantly decreased by both sulfite treatment and SOX deficiency compared to the control. There was also a significant decrease in plasma TAC level by sulfite treatment. In conclusion, sulfite treatment affects the antioxidant/oxidant balance of the plasma cells of the rats toward oxidants in SOX-deficient groups.

  13. Plasma lipid oxidation predicts atherosclerotic status better than cholesterol in diabetic apolipoprotein E deficient mice

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    Petersen, Karen Ekkelund; Lykkesfeldt, Jens; Raun, Kirsten

    2017-01-01

    significantly different from the control group as they had higher blood glucose, HbA1c, total cholesterol, low-density lipoprotein, very low-density lipoprotein, together with a lower high-density lipoprotein concentration and body weight. Animals in the diabetic group had significantly higher plaque area......Increased levels of oxidative stress have been suggested to play a detrimental role in the development of diabetes-related vascular complications. Here, we investigated whether the concentration of malondialdehyde, a marker of lipid oxidation correlated to the degree of aortic plaque lesions...... in a proatherogenic diabetic mouse model. Three groups of apolipoprotein E knockout mice were studied for 20 weeks, a control, a streptozotocin-induced diabetic, and a diabetic enalapril-treated group. Enalapril was hypothesized to lower oxidative stress level and thus the plaque burden. Both diabetic groups were...

  14. The effect of agility exercise on eicosanoid excretion, oxidant status, and plasma lactate in dogs

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    Baltzer Wendy I

    2012-12-01

    Full Text Available Abstract Background The objective was to determine the effects of agility exercise on dogs of different skill levels with respect to urinary eicosanoids, urinary 15F2t-isoprostane (lipid peroxidation marker and hematological/biochemical changes in plasma. Fifteen adult dogs had blood and urine samples obtained prior to, immediately and 4-hours following an agility exercise. Results Hematocrit, red blood cells (RBC, albumin, and hemoglobin increased following exercise, with greatest increases correlating to increased skill group (novice, intermediate, masters; at 4-hours post-exercise, hematocrit, RBC, and hemoglobin were decreased. Phosphorus increased following exercise with the greatest increase in novice and intermediates. Plasma lactate increased 3.6-fold in masters, 3.2-fold in intermediates, and 1.2-fold in novice dogs. Urine thromboxane B2 (TXB2 more than tripled 4-hours post-exercise while 6-keto prostaglandin F1α (PGF1α, prostacyclin metabolite, prostaglandin E2 metabolites (13,14-dihydro-15-keto-prostaglandin A2 and 13,14-dihydro-15-keto-prostaglandin E2, and 13,14-dihydro-15-keto prostaglandin F2α were unaffected as determined by a competitive enzyme immunoassay and standardized by division with urine creatinine. Urine 15F2t-isoprostane increased insignificantly. Conclusions Alterations in the plasma post-exercise were likely due to hemoconcentration from insensible water loss, splenic contraction and sympathetic stimulation while 4-hours later autohemodilution reduced RBC parameters. Elevations in plasma lactate and urinary TXB2 correlated with advanced skill level/speed of the dogs.

  15. The effect of acute pre-exercise dark chocolate consumption on plasma antioxidant status, oxidative stress and immunoendocrine responses to prolonged exercise.

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    Davison, Glen; Callister, Robin; Williamson, Gary; Cooper, Karen A; Gleeson, Michael

    2012-02-01

    Acute antioxidant supplementation may modulate oxidative stress and some immune perturbations that typically occur following prolonged exercise. The aims of the present study were to examine the effects of acutely consuming dark chocolate (high polyphenol content) on plasma antioxidant capacity, markers of oxidative stress and immunoendocrine responses to prolonged exercise. Fourteen healthy men cycled for 2.5 h at ~60% maximal oxygen uptake 2 h after consuming 100 g dark chocolate (DC), an isomacronutrient control bar (CC) or neither (BL) in a randomised-counterbalanced design. DC enhanced pre-exercise antioxidant status (P = 0.003) and reduced by trend (P = 0.088) 1 h post-exercise plasma free [F₂-isoprostane] compared with CC (also, [F₂-isoprostane] increased post-exercise in CC and BL but not DC trials). Plasma insulin concentration was significantly higher pre-exercise (P = 0.012) and 1 h post-exercise (P = 0.026) in the DC compared with the CC trial. There was a better maintenance of plasma glucose concentration on the DC trial (2-way ANOVA trial × time interaction P = 0.001), which decreased post-exercise in all trials but was significantly higher 1 h post-exercise (P = 0.039) in the DC trial. There were no between trial differences in the temporal responses (trial × time interactions all P > 0.05) of hypothalamic-pituitary-adrenal axis stress hormones, plasma interleukin-6, the magnitude of leukocytosis and neutrophilia and changes in neutrophil function. Acute DC consumption may affect insulin, glucose, antioxidant status and oxidative stress responses, but has minimal effects on immunoendocrine responses, to prolonged exercise.

  16. Effects of erdosteine treatment against doxorubicin-induced toxicity through erythrocyte and plasma oxidant/antioxidant status in rats.

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    Fadillioğlu, Ersin; Erdoğan, Hasan

    2003-04-01

    The clinical use of doxorubicin (Dxr), an antineoplastic agent, is limited by its extensive toxicity which is mostly mediated by oxidant injury. We have studied the effect of erdosteine, a mucolytic drug showing antioxidant properties, in preventing Dxr-toxicity to improve future Dxr therapy. Male Sprague-Dawley rats were divided into four groups. The first group that underwent no medication was accepted as control group; the second group was treated with a single i.p. injection of Dxr (20 mg kg(-1) b.wt.); the third group was treated with oral erdosteine alone (10 mg kg(-1) b.wt. day(-1) for 12 days); and in the last group erdosteine was administered starting before Dxr injection for 12 days. The thiobarbituric acid reactive substances (TBARS) level of Dxr group was higher in both plasma and erythrocyte than the other groups. In plasma and erythrocyte, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were increased in Dxr plus erdosteine group in comparison with control group, and the activities of GSH-Px were increased in Dxr plus erdosteine group in comparison with Dxr group. The erythrocyte catalase (CAT) activity of Dxr plus erdosteine group was higher than control and Dxr groups. Plasma xanthine oxidase activities and nitric oxide (NO) levels were not significantly different between groups, however erythrocyte NO level of Dxr group was higher than control. In conclusion, Dxr administration resulted in increased lipid peroxidation in plasma as well as erythrocyte and erdosteine treatment helped to prevent oxidative injury by increasing antioxidant enzymes, especially SOD, GSH-Px and CAT, in rats.

  17. Intermittent hypoxia and diet-induced obesity: effects on oxidative status, sympathetic tone, plasma glucose and insulin levels, and arterial pressure.

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    Olea, Elena; Agapito, Maria Teresa; Gallego-Martin, Teresa; Rocher, Asuncion; Gomez-Niño, Angela; Obeso, Ana; Gonzalez, Constancio; Yubero, Sara

    2014-10-01

    Obstructive sleep apnea (OSA) consists of sleep-related repetitive obstructions of upper airways that generate episodes of recurrent or intermittent hypoxia (IH). OSA commonly generates cardiovascular and metabolic pathologies defining the obstructive sleep apnea syndrome (OSAS). Literature usually links OSA-associated pathologies to IH episodes that would cause an oxidative status and a carotid body-mediated sympathetic hyperactivity. Because cardiovascular and metabolic pathologies in obese patients and those with OSAS are analogous, we used models (24-wk-old Wistar rats) of IH (applied from weeks 22 to 24) and diet-induced obesity (O; animals fed a high-fat diet from weeks 12 to 24) to define the effect of each individual maneuver and their combination on the oxidative status and sympathetic tone of animals, and to quantify cardiovascular and metabolic parameters and their deviation from normality. We found that IH and O cause an oxidative status (increased lipid peroxides and diminished activities of superoxide dismutases), an inflammatory status (augmented C-reactive protein and nuclear factor kappa-B activation), and sympathetic hyperactivity (augmented plasma and renal artery catecholamine levels and synthesis rate); combined treatments worsened those alterations. IH and O augmented liver lipid content and plasma cholesterol, triglycerides, leptin, glycemia, insulin levels, and HOMA index, and caused hypertension; most of these parameters were aggravated when IH and O were combined. IH diminished ventilatory response to hypoxia, and hypercapnia and O created a restrictive ventilatory pattern; a combination of treatments led to restrictive hypoventilation. Data demonstrate that IH and O cause comparable metabolic and cardiovascular pathologies via misregulation of the redox status and sympathetic hyperactivity.

  18. Maternal plasma levels of interleukin-6, C-reactive protein, vitamins C, E and A, 8-isoprostane and oxidative status in women with preterm premature rupture of membranes.

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    Ilhan, Nevin; Celik, Ebru; Kumbak, Banu

    2015-02-01

    Preterm premature rupture of membranes (PPROM) is associated with significant maternal and perinatal morbidity. This study examined maternal oxidative stress in PPROM. This was a prospective cross-sectional study conducted in a university hospital. A total of 72 pregnant women were recruited into two groups, those with PPROM (38 cases) and those without PPROM (34 controls) matched for gestational age. Plasma interleukin-6, C-reactive protein, vitamins C, E and A, 8-isoprostane, total oxidant status (TOS) and antioxidant status (TAS) were determined for all study participants and the data were compared between the PPROM and control groups. Both case and control groups were comparably matched in age, parity, gestational age and smoking status. There was a significant association between low 8-isoprostane, low vitamin C and high total oxidant status and the occurrence of PPROM (p vitamin C and 8-isoprostane levels were lower and TOS higher in women with PPROM. Further research is needed to identify robust biological markers for the prevention and also prognosis of PPROM.

  19. Dietary arginine and N-carbamylglutamate supplementation enhances the antioxidant statuses of the liver and plasma against oxidative stress in rats.

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    Cao, Wei; Xiao, Liang; Liu, Guangmang; Fang, Tingting; Wu, Xianjian; Jia, Gang; Zhao, Hua; Chen, Xiaoling; Wu, Caimei; Cai, Jingyi; Wang, Jing

    2016-05-18

    N-Carbamylglutamate (NCG), an effective precursor of arginine (ARG), can enhance ARG synthesis, increase intestinal growth, and improve reproductive performance. However, the antioxidant effect of NCG remains largely unknown. This study aims to survey the effects of ARG and NCG supplementation on the antioxidant statuses of the liver and plasma in rats under oxidative stress. Rats were fed for 30 days with one of the three iso-nitrogenous diets: basal diet (BD), BD plus 1% ARG, and BD plus 0.1% NCG. On day 28, half of the rats fed with BD were intraperitoneally injected with 12 mg per kg body weight of diquat (diquat group) and the other half was injected intraperitoneally with sterile 0.9% NaCl solution (control group). The other diet groups also received an intraperitoneal injection of 12 mg per kg body weight of diquat, as follows: diquat + 1% ARG (DT + ARG), and diquat + 0.1% NCG (DT + NCG). Rat liver and plasma samples obtained 48 h after diquat injection were analyzed. Results indicated that diquat significantly affected the plasma conventional biochemical components (relative to the controls), which were partially alleviated in both the DT + ARG and DT + NCG groups (P < 0.05). Diquat also significantly decreased the glutathione (GSH) content (by 30.0%), and decreased anti-superoxide anion (ASA; by 13.8%) and anti-hydroxyl radical (AHR; by 38.9%) abilities in the plasma, and also decreased catalase (CAT) activity both in the liver (by 17.5%) and plasma (by 33.4%) compared with the control group. By contrast, diquat increased the malondialdehyde (MDA) content (by 23.0%) in the plasma (P < 0.05) compared with the control group. Relative to those of the diquat group, higher CAT activity and GSH content were noted in the plasma of the DT + ARG group and in the liver of both DT + ARG and DT + NCG groups (P < 0.05). Furthermore, the DT + ARG group exhibited significantly enhanced plasma ASA activity (P < 0.05). The DT + NCG group showed significantly improved total

  20. Role of Lipid Peroxidation Products, Plasma Total Antioxidant Status, and Cu-, Zn-Superoxide Dismutase Activity as Biomarkers of Oxidative Stress in Elderly Prediabetics

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    Sylwia Dzięgielewska-Gęsiak

    2014-01-01

    Full Text Available The relationship between hyperglycemia and oxidative stress in diabetes is well known, but the influence of metabolic disturbances recognized as prediabetes, in elderly patients especially, awaits for an explanation. Methods. 52 elderly persons (65 years old and older with no acute or severe chronic disorders were assessed: waist circumference (WC, body mass index (BMI, percentage of body fat (FAT, and arterial blood pressure. During an oral glucose tolerance test (OGTT fasting (0′ and 120-minute (120′ glycemia and insulinemia were determined, and type 2 diabetics (n=6 were excluded. Subjects were tested for glycated hemoglobin HbA1c, plasma lipids, total antioxidant status (TAS, thiobarbituric acid-reacting substances (TBARS, and activity of erythrocyte superoxide dismutase (SOD-1. According to OGTT results, patients were classified as normoglycemics, (NGT, n=18 and prediabetics, (PRE, n=28. Results. Both groups did not differ with their lipids, FAT, and TBARS. PRE group had higher WC (P<0.002 and BMI (P<0.002. Lower SOD-1 activity (P<0.04 and TAS status (P<0.04 were found in PRE versus NGT group. Significance. In elderly prediabetics, SOD-1 and TAS seem to reflect the first symptoms of oxidative stress, while TBARS are later biomarkers of oxidative stress.

  1. Influences of Intermittent Anaerobic Exercise Program on Physical Fitness and Plasma Lactate, Oxidant and Anti-oxidant Status in Smokers and Non-smokers Judo Players

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    Bushra H. El-Zawahry*; Gamal A. Shawer**

    2007-06-01

    Full Text Available Background: There is evidence of smoking's negative impact and physical activity's positive impact on long-term health. However, evidences regarding the association between smoking and exercise activity and the independent effects of these factors on antioxidant defense are lacking. The aim of this study is to investigate the association between smoking and the intermittent anaerobic exercise on the physical fitness, oxidant and antioxidant status in Judo player. Methods: Twenty male Judo player student from Department of Physical Education Al-Azhar University were enrolled in the study. They were of 2 groups, Non-smokers (NS and smokers (SM. Both groups were subjected to regular Judo training program (2 hours/day, 3 sessions/week for 12 weeks. Also, both groups were subjected to an effort test (running of submaximal intensity until exhaustion and record of the maximum oxygen capacity (VO2max using an ergometric bicycle. Heart rate (HR, mean arterial blood pressure (MBP were recorded and blood samples were taken pre and post-effort test for determination of malondialdehyde (MDA,total antioxidant capacity (TAC, uric acid (Ua and lactate (La in the plasma. Also the time to exhaustion was recorded during the effort test. These measures were performed pre and post the training program. Results: At rest the pre-program data of SM showed significantly higher H.R., and plasma MDA ,and significantly lower TAC with tendency to increase in MBP and La levels, and decrease in VO2max, and Ua levels compared to NS. Before program and in response to acute exercise SM showed significantly higher H.R, MDA and La levels with significantly lower TAC, Ua and time to exhaustion compared to NS. On the other hand, after the program and in response to acute exercise, SM showed more pronounced significantly higher HR, MBP, MDA and La with significantly lower VO2max, time to exhaustion and TAC with insignificant changes in the Ua compared to the NS that showed

  2. Total antioxidant and oxidant status of plasma and renal tissue of cisplatin-induced nephrotoxic rats: protection by floral extracts of Calendula officinalis Linn.

    Science.gov (United States)

    Verma, Pawan Kumar; Raina, Rajinder; Sultana, Mudasir; Singh, Maninder; Kumar, Pawan

    2016-01-01

    The present study was aimed to determine the total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI) of plasma and renal tissue in cisplatin (cDDP) induced nephrotoxic rats and its protection by treatments with floral extracts of Calendula officinalis Linn. Treatment with cDDP elevated (p GSH) and antioxidant enzymes compared to the control group. Pre- and post-treatments of ethanolic floral extract of C. officinalis along with cDDP restored (p > 0.05) CR, albumin, TOS, GSH and activities of antioxidant enzymes in blood and renal tissue. Ethanolic extract treatments reduced (p < 0.05) MDA level in renal tissue without restoring the erythrocyte MDA level following cDDP treatment. These observations were further supported by the histopathological findings in renal tissue. Observations of the present study have shown that treatments with ethanolic floral extract of C. officinalis protect cDDP induced nephrotoxicity by restoring antioxidant system of the renal tissue.

  3. Chronic fatigue syndrome: acute infection and history of physical activity affect resting levels and response to exercise of plasma oxidant/antioxidant status and heat shock proteins.

    Science.gov (United States)

    Jammes, Y; Steinberg, J G; Delliaux, S

    2012-07-01

    A history of high-level physical activity and/or acute infection might constitute stress factors affecting the plasma oxidant-antioxidant status and levels of heat shock proteins (HSPs) in patients with chronic fatigue syndrome (CFS). This case-control study compared data from 43 CFS patients to results from a matched control group of 23 healthy sedentary subjects. Five patients had no relevant previous history (group I). Eighteen had practised high-level sport (group II), and severe acute infection had been diagnosed in nine patients (group III). A combination of sport practice and infection was noted in 11 patients (group IV). After examination at rest, all subjects performed a maximal cycling exercise test. Plasma levels of two markers of oxidative stress [thiobarbituric acid reactive substances (TBARS) and reduced ascorbic acid (RAA)] and both HSP27 and HSP70 were measured. At rest, compared with the control group, the TBARS level was higher in groups II, III and IV patients, and the RAA level was lower in groups III and IV. In addition, HSP70 levels were significantly lower in all CFS groups, compared with controls, but negative correlations were found between resting HSP27 and HSP70 levels and the history of physical activity. After exercise, the peak level of TBARS significantly increased in groups II, III and IV, and the variations in HSP27 and HSP70 were attenuated or suppressed, with the greatest effects in groups III and IV. The presence of stress factors in the history of CFS patients is associated with severe oxidative stress and the suppression of protective HSP27 and HSP70 responses to exercise. © 2011 The Association for the Publication of the Journal of Internal Medicine.

  4. Comparative blood and seminal plasma oxidant/antioxidant status of Arab stallions with different ages and their relation to semen quality

    OpenAIRE

    2016-01-01

    Objective: To investigate the antioxidant/oxidant levels in blood serum and seminal plasma of Arab stallion with different ages and their relation to semen quality. Methods: Healthy Arabian stallions (n = 57), were divided into three groups. Young (5–10years), Moderate (11–16 years) and Old stallions (>16 years) were subjected to semen evaluation. Seminal plasma and blood samples were collected and stored at −20 °C for measuring glutathione reduced, nitric oxide, Malondialdehyde, ascorbic ...

  5. Plasma electrolytic oxidation of metals

    Directory of Open Access Journals (Sweden)

    Stojadinović Stevan

    2013-01-01

    Full Text Available In this lecture results of the investigation of plasma electrolytic oxidation (PEO process on some metals (aluminum, titanium, tantalum, magnesium, and zirconium were presented. Whole process involves anodizing metals above the dielectric breakdown voltage where numerous micro-discharges are generated continuously over the coating surface. For the characterization of PEO process optical emission spectroscopy and real-time imaging were used. These investigations enabled the determination of electron temperature, electron number density, spatial density of micro-discharges, the active surface covered by micro-discharges, and dimensional distribution of micro-discharges at various stages of PEO process. Special attention was focused on the results of the study of the morphology, chemical, and phase composition of oxide layers obtained by PEO process on aluminum, tantalum, and titanium in electrolytes containing tungsten. Physicochemical methodes: atomic force microscopy (AFM, scanning electron microscopy (SEM-EDS, x-ray diffraction (XRD, x-ray photoelectron spectroscopy (XPS, and Raman spectroscopy served as tools for examining obtained oxide coatings. Also, the application of the obtained oxide coatings, especially the application of TiO2/WO3 coatings in photocatalysis, were discussed.

  6. Plasma electrolytic oxidation of AMCs

    Science.gov (United States)

    Morgenstern, R.; Sieber, M.; Lampke, T.

    2016-03-01

    Aluminum Matrix Composites (AMCs) consisting of high-strength alloys and ceramic reinforcement phases exhibit a high potential for security relevant lightweight components due to their high specific mechanical properties. However, their application as tribologically stressed components is limited because of their susceptibility against fatigue wear and delamination wear. Oxide ceramic protective coatings produced by plasma electrolytic oxidation (PEO) can solve these problems and extend the possible applications of AMCs. The substrate material was powder metallurgically processed using alloy EN AW 2017 and SiC or Al2O3 particles. The influence of material properties like particle type, size and volume fraction on coating characteristics is clarified within this work. An alkaline silicate electrolyte was used to produce PEO coatings with technically relevant thicknesses under bipolar-pulsed current conditions. Coating properties were evaluated with regard to morphology, chemical composition, hardness and wear resistance. The particle type proved to have the most significant effect on the coating properties. Whereas compactness and thickness are not deteriorated by the incorporation of thermodynamically stable alumina particles, the decomposition of silica particles during the PEO processes causes an increase of the porosity. The higher silica particle content decreases also the coating thickness and hardness, which leads in particular to reduction of the wear resistance of the PEO coatings. Finally, different approaches for the reduction of the coating porosity of silica reinforced AMCs are discussed.

  7. Periodontal treatment decreases plasma oxidized LDL level and oxidative stress.

    Science.gov (United States)

    Tamaki, Naofumi; Tomofuji, Takaaki; Ekuni, Daisuke; Yamanaka, Reiko; Morita, Manabu

    2011-12-01

    Periodontitis induces excessive production of reactive oxygen species in periodontal lesions. This may impair circulating pro-oxidant/anti-oxidant balance and induce the oxidation of low-density lipoprotein (LDL) in blood. The purpose of this study was to monitor circulating oxidized LDL and oxidative stress in subjects with chronic periodontitis following non-surgical periodontal treatment. Plasma levels of oxidized LDL and oxidative stress in 22 otherwise healthy non-smokers with chronic periodontitis (mean age 44.0 years) were measured at baseline and at 1 and 2 months after non-surgical periodontal treatment. At baseline, chronic periodontitis patients had higher plasma levels of oxidized LDL and oxidative stress than healthy subjects (p surgical periodontal treatment were effective in decreasing oxLDL, which was positively associated with a reduction in circulating oxidative stress.

  8. Alterations in magnesium and oxidative status during chronic emotional stress.

    Science.gov (United States)

    Cernak, I; Savic, V; Kotur, J; Prokic, V; Kuljic, B; Grbovic, D; Veljovic, M

    2000-03-01

    Magnesium and oxidative status were investigated in young volunteers exposed to chronic stress (political intolerance, awareness of potential military attacks, permanent stand-by duty and reduced holidays more than 10 years) or subchronic stress consisting of everyday mortal danger in military actions lasting more than 3 months. Significant decreases in plasma ionized Mg2+, total Mg and ionized Ca2+ concentrations were found in both groups. Similarly, both study groups exhibited oxidative stress as assessed by increased plasma superoxide anions and malondialdehyde and modified antioxidant defense. There were no significant differences between the two stress groups. A negative correlation between magnesium balance and oxidative stress was observed suggesting that the same etiological factor (chronic stress) initiate decreases in both free and total magnesium concentrations and simultaneously increase oxidative stress intensity. These findings support the need for magnesium supplementation with antioxidant vitamins for people living in conditions of chronic stress.

  9. Oxidative stress and antioxidant status in fetal circulation in preeclampsia.

    Science.gov (United States)

    Braekke, Kristin; Harsem, Nina K; Staff, Anne C

    2006-11-01

    Preeclampsia is associated with oxidative stress in maternal circulation. The purpose of this study was to explore oxidative stress and antioxidants in the fetal circulation in preeclampsia. Women with preeclampsia (n = 19) or uncomplicated pregnancies (n = 33) delivered by cesarean section were included. Blood was sampled separately from the umbilical vein and artery. 8-Iso-prostaglandin F(2alpha) (8-isoprostane), a stable product of lipid peroxidation, is a reliable marker of oxidative stress. Concentration of total 8-isoprostane in cord plasma was analyzed by gas chromatography-mass spectrometry. Antioxidant status was evaluated measuring ferric reducing ability of plasma and vitamin E. There was no difference between preeclampsia and control groups regarding median plasma concentration of 8-isoprostane in umbilical vein (955 versus 780 pg/mL, p = 0.41) or in umbilical artery (233 versus 276 pg/mL, p = 0.65). Concentration of 8-isoprostane was much higher in plasma from the umbilical vein than artery, suggesting placenta as the source of 8-isoprostane. Median ferric reducing ability of plasma concentration was higher in preeclampsia than in controls, both in the umbilical vein and artery. Median vitamin E concentration in the umbilical vein was higher in preeclampsia, but no difference was found in the umbilical artery. In conclusion, no evidence of increased oxidative stress, evaluated by 8-isoprostane concentration, was found in fetal circulation in preeclampsia.

  10. Can Breast Tumors Affect the Oxidative Status of the Surrounding Environment? A Comparative Analysis among Cancerous Breast, Mammary Adjacent Tissue, and Plasma.

    Science.gov (United States)

    Panis, C; Victorino, V J; Herrera, A C S A; Cecchini, A L; Simão, A N C; Tomita, L Y; Cecchini, R

    2015-01-01

    In this paper, we investigated the oxidative profile of breast tumors in comparison with their normal adjacent breast tissue. Our study indicates that breast tumors present enhanced oxidative/nitrosative stress, with concomitant augmented antioxidant capacity when compared to the adjacent normal breast. These data indicate that breast cancers may be responsible for the induction of a prooxidant environment in the mammary gland, in association with enhanced TNF-α and nitric oxide.

  11. Plasma Post Oxidation of Plasma Nitrocarburized SKD 61 Steel

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Plasma nitrocarburizing and plasma oxidizing treatments were performed to improve the wear and corrosion resistance of SKD 61 steel. Plasma nitrocarburizing was conducted for 12 h at 540℃ in the nitrogen,hydrogen and methane atmosphere to produce the ε-Fe,2-3(N,C) phase. The compound layer produced by plasma nitrocarburising was predominantly composed of ε-phase, with a small proportion of γ′-Fe4(N,C) phase.The thickness of the compound layer and the diffusion layer are about 10 μm and about 200μm, respectively.Plasma post oxidation was performed on the nitrocarburized samples with various oxygen/hydrogen ratio at constant temperature of 500℃ for 1 h. The very thin magnetite (Fe3O4) layer of 1-2μm in thickness on top of the compound layer was obtained. Anodic polarization test revealed that plasma nitrocarburizing process contributed a significant improvement of corrosion resistance of SKD 61 steel. However, the corrosion characteristics of the nitrocarburized compound layer was deteriorated by oxidation treatment.

  12. Peroxynitrite-mediated oxidation of plasma fibronectin

    DEFF Research Database (Denmark)

    Degendorfer, Georg; Chuang, Christine Y; Kawasaki, Hiroaki

    2016-01-01

    Fibronectin is a large dimeric glycoprotein present in both human plasma and in basement membranes. The latter are specialized extracellular matrices underlying endothelial cells in the artery wall. Peroxynitrous acid (ONOOH) a potent oxidizing and nitrating agent, is formed in vivo from superoxide...... and nitric oxide radicals by stimulated macrophages and other cells. Considerable evidence supports ONOOH involvement in human atherosclerotic lesion development and rupture, possibly via extracellular matrix damage. Here we demonstrate that Tyr and Trp residues on human plasma fibronectin are highly...

  13. Plasma gasification of coal in different oxidants

    Energy Technology Data Exchange (ETDEWEB)

    Matveev, I.B.; Messerle, V.E.; Ustimenko, A.B. [Applied Plasma Technology, Mclean, VA (USA)

    2008-12-15

    Oxidant selection is the highest priority for advanced coal gasification-process development. This paper presents comparative analysis of the Powder River Basin bituminous-coal gasification processes for entrained-flow plasma gasifier. Several oxidants, which might be employed for perspective commercial applications, have been chosen, including air, steam/carbon-dioxide blend, carbon dioxide, steam, steam/air, steam/oxygen, and oxygen. Synthesis gas composition, carbon gasification degree, specific power consumptions, and power efficiency for these processes were determined. The influence of the selected oxidant composition on the gasification-process main characteristics have been investigated.

  14. Optical endpoint detection for plasma reduction of graphene oxide

    Directory of Open Access Journals (Sweden)

    MaengJun Kim

    2013-03-01

    Full Text Available The plasma reduction process for the production of reduced graphene oxide (rGO requires precise process control in order to avoid the degradation of electrical characteristics. We report that the reduction status of the graphene oxides could be determined by monitoring the optical emission intensity at 844.6 nm. Properties of the rGO samples processed with various plasma exposure times were characterized by X-ray photoelectron spectroscopy, Raman spectroscopy, atomic force microscopy, and 4-point probe measurements. Optimum electrical performance and surface morphology were obtained from the sample for which the reduction process was stopped when the emission intensity at 844.6 nm began to decrease.

  15. Reactive plasma synthesis of nanocrystalline ceramic oxides

    Science.gov (United States)

    Sreekumar, K. P.; Vijay, M.; Thiyagarajan, T. K.; Krishnan, K.; Ananthapadmanabhan, P. V.

    2010-02-01

    Reactive plasma synthesis is an attractive route to synthesize nanocrystalline materials. A 40 kW DC non-transferred arc plasma reactor has been designed and developed in our laboratory for synthesis of nanocrystalline materials. The main components of the plasma reactor include a 40 kW DC plasma generator or plasma torch, water-cooled reactor segment, product collection facility, DC power supply, cooling-water system and exhaust gas vent. The system has been used to synthesize nano-crystalline oxides of aluminium, titanium and zirconium. Aluminium metal powder was used as the starting material to synthesize alumina. The hydrides of Ti and Zr were used as the precursor for synthesis of nanocrystalline titania and zirconia respectively. The precursor powders were injected into the thermal plasma jet and were allowed to react with oxygen injected downstream the jet. The precursor powder particles were oxidized 'in-flight' to form nano-sized powder of the respective metal, which deposited on the walls of the reactor and collector assembly. Various analytical tools were used to characterized the products.

  16. Status of Chronic Oxidation Studies of Graphite

    Energy Technology Data Exchange (ETDEWEB)

    Contescu, Cristian I. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mee, Robert W. [Univ. of Tennessee, Knoxville, TN (United States)

    2016-05-01

    Graphite will undergo extremely slow, but continuous oxidation by traces of moisture that will be present, albeit at very low levels, in the helium coolant of HTGR. This chronic oxidation may cause degradation of mechanical strength and thermal properties of graphite components if a porous oxidation layer penetrates deep enough in the bulk of graphite components during the lifetime of the reactor. The current research on graphite chronic oxidation is motivated by the acute need to understand the behavior of each graphite grade during prolonged exposure to high temperature chemical attack by moisture. The goal is to provide the elements needed to develop predictive models for long-time oxidation behavior of graphite components in the cooling helium of HTGR. The tasks derived from this goal are: (1) Oxidation rate measurements in order to determine and validate a comprehensive kinetic model suitable for prediction of intrinsic oxidation rates as a function of temperature and oxidant gas composition; (2) Characterization of effective diffusivity of water vapor in the graphite pore system in order to account for the in-pore transport of moisture; and (3) Development and validation of a predictive model for the penetration depth of the oxidized layer, in order to assess the risk of oxidation caused damage of particular graphite grades after prolonged exposure to the environment of helium coolant in HTGR. The most important and most time consuming of these tasks is the measurement of oxidation rates in accelerated oxidation tests (but still under kinetic control) and the development of a reliable kinetic model. This report summarizes the status of chronic oxidation studies on graphite, and then focuses on model development activities, progress of kinetic measurements, validation of results, and improvement of the kinetic models. Analysis of current and past results obtained with three grades of showed that the classical Langmuir-Hinshelwood model cannot reproduce all

  17. DNA damage and oxidative status in PFAPA syndrome.

    Science.gov (United States)

    Tuğrul, Selahattin; Doğan, Remzi; Kocyigit, Abdurrahim; Torun, Emel; Senturk, Erol; Ozturan, Orhan

    2015-10-01

    PFAPA syndrome is a clinical entity of unknown etiology which presents with periodic episodes of fever, aphthous stomatitis, tonsillitis or pharyngitis, and cervical adenitis. In this study we investigated DNA damage and the oxidative stress parameters in patients diagnosed with PFAPA, to elucidate the underlying pathophysiological mechanism of this syndrome. Thirty-one patients diagnosed with PFAPA (Group 1), 22 patients diagnosed with normal tonsillitis or pharyngitis (Group 2), and 20 healthy volunteers (Group 3) were included in our study. Heparinized peripheral blood samples were drawn from all patients and volunteers. DNA damage was assessed by single cell alkaline electrophoresis assay in peripheral mononuclear leukocytes. Plasma levels of total antioxidant status (TAS) and total oxidative status (TOS) were determined by using a novel automated measurement method, and oxidative stress index (OSI) was calculated. DNA damage in the mononuclear leukocytes of Group 1 was significantly higher than that of Group 2 and Group 3. The oxidative stress parameters revealed that the TOS and OSI values of Group 1 were significantly higher than those of Group 2 and Group 3. TAS values of Group 1 were significantly lower than those of Group 2 and Group 3. Correlation analysis of Group 1 demonstrated a significant correlation between TOS, one of the oxidative stress parameters, and DNA damage. Correlations between DNA damage and C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) values were also significant. Our study indicated that both the inflammatory and the oxidative stress parameters were significantly increased in patients with PFAPA syndrome, accompanied by a significant positive correlation between DNA damage and oxidative stress. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  18. Serum Biomarkers of (AntiOxidant Status for Epidemiological Studies

    Directory of Open Access Journals (Sweden)

    Eugène Jansen

    2015-11-01

    Full Text Available In this review, we disclose a selection of serum/plasma biomarkers of (antioxidant status related to nutrition, which can be used for measurements in large-scale epidemiological studies. From personal experience, we have come to the following proposal of a set of biomarkers for nutritional intake, (antioxidant status, and redox status. We have selected the individual antioxidant vitamins E and A, and the carotenoids which can be measured in large series by HPLC. In addition, vitamin C was selected, which can be measured by an auto-analyzer or HPLC. As a biomarker for oxidative stress, the ROM assay (reactive oxygen metabolites was selected; for the redox status, the total thiol assay; and for the total antioxidant status the BAP assay (biological antioxidant potential. All of these biomarkers can be measured in large quantities by an auto-analyzer. Critical points in biomarker validation with respect to blood sampling, storage conditions, and measurements are discussed. With the selected biomarkers, a good set is presented for use in the risk assessment between nutrition and (chronic diseases in large-scale epidemiological studies. Examples of the successful application of these biomarkers in large international studies are presented.

  19. Plasma electrolytic oxidation of Titanium Aluminides

    Science.gov (United States)

    Morgenstern, R.; Sieber, M.; Grund, T.; Lampke, T.; Wielage, B.

    2016-03-01

    Due to their outstanding specific mechanical and high-temperature properties, titanium aluminides exhibit a high potential for lightweight components exposed to high temperatures. However, their application is limited through their low wear resistance and the increasing high-temperature oxidation starting from about 750 °C. By the use of oxide ceramic coatings, these constraints can be set aside and the possible applications of titanium aluminides can be extended. The plasma electrolytic oxidation (PEO) represents a process for the generation of oxide ceramic conversion coatings with high thickness. The current work aims at the clarification of different electrolyte components’ influences on the oxide layer evolution on alloy TNM-B1 (Ti43.5Al4Nb1Mo0.1B) and the creation of compact and wear resistant coatings. Model experiments were applied using a ramp-wise increase of the anodic potential in order to show the influence of electrolyte components on the discharge initiation and the early stage of the oxide layer growth. The production of PEO layers with technically relevant thicknesses close to 100 μm was conducted in alkaline electrolytes with varying amounts of Na2SiO3·5H2O and K4P2O7 under symmetrically pulsed current conditions. Coating properties were evaluated with regard to morphology, chemical composition, hardness and wear resistance. The addition of phosphates and silicates leads to an increasing substrate passivation and the growth of compact oxide layers with higher thicknesses. Optimal electrolyte compositions for maximum coating hardness and thickness were identified by statistical analysis. Under these conditions, a homogeneous inner layer with low porosity can be achieved. The frictional wear behavior of the compact coating layer is superior to a hard anodized layer on aluminum.

  20. Nanodispersed Oxides-Plasma-Chemical Synthesis and Properties

    Institute of Scientific and Technical Information of China (English)

    Gheorghi VISSOKOV; Katerina ZAHARIEVA

    2007-01-01

    We discuss the plasma-chemical synthesis and the properties of transition metals oxides, Al2O3, SiO2, rare-earth oxides, oxides for ceramics and metal-ceramics, and oxides used as catalysts. Bearing in mind the indisputable advantages of using plasma-chemically synthesized nanodispersed oxides for the needs of various industrial fields, we set out to review the articles published in the past few years devoted to the problems of plasma-chemical synthesis and characterization of nanodispersed oxides.

  1. Oxidants and anti-oxidants status in acne vulgaris patients with varying severity.

    Science.gov (United States)

    Al-Shobaili, Hani A

    2014-01-01

    Acne vulgaris is a common dermatological disorder with a multifactorial pathogenesis. Oxidative status has been implicated in the pathogenesis of several skin diseases, including acne. This study was aimed to investigate the levels of oxidative stress biomarkers in acne vulgaris patients with varying severities. The study involved 156 patients with acne and 46 healthy human controls. Based on clinical examination, patients were grouped into 3 subgroups as follows: mild, moderate, and severe acne. Oxidative stress was examined by measuring plasma levels of catalase (CAT), superoxide dismutase (SOD), total antioxidant capacity (TAC), and malondialdehyde (MDA). Plasma levels of MDA in acne patients were significantly higher as compared with that of the controls, whereas activities of the antioxidant enzymes SOD and CAT were lower. Moreover, TAC was also low in acne patients as compared with that of the controls. Higher MDA levels in the severe acne subgroup as compared with that of the mild and moderate subgroups were also observed. Furthermore, in the severe acne subgroup, a significant negative correlation was observed between MDA and CAT levels. The data suggests that oxidative stress plays a key role in acne progress and may be employed as a biomarker index to assess the disease's activity and to monitor its treatment.

  2. Solid Oxide Fuel Cells: Technology Status

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Prabhakar; Minh, Nguyen Q.

    2004-08-01

    In its most common configuration, solid oxide fuel cell (SOFC) uses an oxygen ion conducting ceramic electrolyte membrane, perovskite cathode and nickel cermet anode electrode. Cells operate in the 600-1000 C temperature range and utilize metallic or ceramic current collectors for cell-to-cell interconnection. Recent development in engineered electrode architectures, component materials chemistry, cell and stack designs and fabrication processes have led to significant improvement in the electrical performance and performance stability as well as reduction in the operating temperature of such cells. Large kW-size power generation systems have been designed and field demonstrated. This paper reviews the status of SOFC power generation systems with emphasis on cell and stack component materials, electrode reactions, materials reactions and corrosion processes

  3. Comparison of direct and indirect plasma oxidation of NO combined with oxidation by catalyst

    DEFF Research Database (Denmark)

    Jogi, Indrek; Stamate, Eugen; Irimiea, Cornelia

    2015-01-01

    Direct and indirect plasma oxidation of NOx was tested in a medium-scale test-bench at gas flows of 50 slm (3 m(3)/h). For direct plasma oxidation the synthetic flue gas was directed through a stacked DBD reactor. For indirect plasma oxidation, a DBD reactor was used to generate ozone from pure O-2...... of the DBD reactor decreased the long-term efficiency of direct plasma oxidation. At the same time, the efficiency of indirect oxidation increased at elevated reactor temperatures. Additional experiments were carried out to investigate the improvement of indirect oxidation by the introduction of catalyst...

  4. Acute Exercise Increases Plasma Total Antioxidant Status and Antioxidant Enzyme Activities in Untrained Men

    OpenAIRE

    Berzosa, C.; I. Cebrián; Fuentes-Broto, L.; E. Gómez-Trullén; Piedrafita, E.; Martínez-Ballarín, E.; López-Pingarrón, L.; Reiter, R. J.; García, J. J.

    2011-01-01

    Antioxidant defences are essential for cellular redox regulation. Since free-radical production may be enhanced by physical activity, herein, we evaluated the effect of acute exercise on total antioxidant status (TAS) and the plasma activities of catalase, glutathione reductase, glutathione peroxidase, and superoxide dismutase and its possible relation to oxidative stress resulting from exercise. Healthy untrained male subjects ( = 3 4 ) performed three cycloergometric tests, including maxi...

  5. Plasma Homocysteine Is Associated with Increased Oxidative Stress and Antioxidant Enzyme Activity in Welders

    Directory of Open Access Journals (Sweden)

    Hung-Hsin Liu

    2013-01-01

    Full Text Available The purpose of this study was to examine the association of vitamin B6 status and plasma homocysteine with oxidative stress and antioxidant capacities in welders. Workers were divided into either the welding exposure group (n=57 or the nonexposure controls (n=42 based on whether they were employed as welders. There were no significant differences in vitamin B6 status and plasma homocysteine concentration between the welding exposure group and the nonexposure controls. The welding exposure group had significantly higher levels of oxidized low-density lipoprotein cholesterol and lower erythrocyte glutathione concentration and superoxide dismutase (SOD activities when compared to nonexposure controls. Plasma pyridoxal 5′-phosphate concentration did not correlate with oxidative stress indicators or antioxidant capacities in either group. However, plasma homocysteine significantly correlated with total antioxidant capacity (TAC (partial rs=-0.34, P<0.05 and erythrocyte SOD activities (partial rs=0.29, P<0.05 after adjusting for potential confounders in the welding exposure group. In the welding exposure group, adequate vitamin B6 status was not associated with oxidative stress or antioxidant capacities. However, elevated plasma homocysteine seemed to be a major contributing factor to antioxidant capacities (TAC and erythrocyte SOD activities in welders.

  6. Effect of off‐road competitive motocross race on plasma oxidative stress and damage markers

    Science.gov (United States)

    Ascensão, António; Ferreira, Rita; Marques, Franklim; Oliveira, Eduardo; Azevedo, Victor; Soares, José; Magalhães, José

    2007-01-01

    Aim To analyse the effect of an off‐road motocross heat on plasma levels of oxidative stress and damage, blood leucocyte counts and urine catecholamine concentration. Methods Plasma contents of total, reduced and oxidised (GSSG) glutathione, %GSSG, malondialdehyde (MDA), protein carbonyl and sulphydryl groups, total antioxidant status (TAS), uric acid, and blood neutrophil and lymphocyte counts were evaluated in 10 male top‐level riders before, immediately after (0 h) and 1 h after a simulated competitive motocross race. 24‐h urine adrenaline, noradrenaline and dopamine concentrations were also measured. Results The motocross heat resulted in an increase in plasma oxidative stress and damage (pmotocross, resulting in a condition of enhanced plasma oxidative stress and damage. PMID:17138632

  7. Effect of off-road competitive motocross race on plasma oxidative stress and damage markers.

    Science.gov (United States)

    Ascensão, António; Ferreira, Rita; Marques, Franklim; Oliveira, Eduardo; Azevedo, Victor; Soares, José; Magalhães, José

    2007-02-01

    To analyse the effect of an off-road motocross heat on plasma levels of oxidative stress and damage, blood leucocyte counts and urine catecholamine concentration. Plasma contents of total, reduced and oxidised (GSSG) glutathione, %GSSG, malondialdehyde (MDA), protein carbonyl and sulphydryl groups, total antioxidant status (TAS), uric acid, and blood neutrophil and lymphocyte counts were evaluated in 10 male top-level riders before, immediately after (0 h) and 1 h after a simulated competitive motocross race. 24-h urine adrenaline, noradrenaline and dopamine concentrations were also measured. The motocross heat resulted in an increase in plasma oxidative stress and damage (pmotocross, resulting in a condition of enhanced plasma oxidative stress and damage.

  8. Status and challenges in electrical diagnostics of processing plasmas

    DEFF Research Database (Denmark)

    Stamate, Eugen

    Reactive plasmas produced in oxygen, nitrogen, hydrogen and other complex gas mixture are used for various applications including thin films, etching, ion implantation, ashing, particles growth, oxidation and other surface functionalization processes. Most of the reactive gases are also...... the possibility to control and use these plasmas for processing. Development of reactive plasma sources for both applications and basic science is rather challenging and some of these efforts will be presented in direct correlation with diagnostic approaches....... electronegative so that, the role of negative ions cannot be neglected. The continuous decrease of the features size in micro- and nanoelectronic industry requires a precise control of plasma parameters including the negative ions. Despite of a good progress in plasma diagnostics, yet more is to be done...

  9. [Changes in Kinetics of Chemiluminescence of Plasma as a Measure of Systemic Oxidative Stress in Humans].

    Science.gov (United States)

    Sozarukova, M M; Polimova, A M; Proskurnina, E V; Vladimirov, Yu A

    2016-01-01

    Oxidative stress is a pathogenetic factor of many diseases. The control of its level is important for early diagnosis and therapy adjustment. In this work, antioxidant status was estimated in blood plasma. In the system of 2,2'-azo-bis(2-amidinopropane)dihydrochloride-luminol a set of chemiluminescence kinetic curve parameters is proposed for oxidative stress level estimation (the latent period τ(lat) and the increasing of analytical signal ΔI(CL)). Uric acid and albumin were shown as the main components that responsible for changes in chemiluminescence kinetic curve of plasma. Serum albumin undergoes oxidative modification in dose-depend manner under the action of UV irradiation, it causes the enhancement of antioxidant properties. Changes in plasma chemiluminescence kinetics are proposed as a measure of oxidative stress in human body.

  10. Operational status of the Magnum-PSI linear plasma device

    Energy Technology Data Exchange (ETDEWEB)

    Scholten, John, E-mail: j.scholten@differ.nl; Zeijlmans van Emmichoven, P.A.; Eck, H.J.N. van; Smeets, P.H.M.; De Temmerman, G.C.; Brons, S.; Berg, M.A. van den; Meiden, H.J. van der; Pol, M.J. van de; Graswinckel, M.F.; Groen, P.W.C.; Poelman, A.J.; Genuit, J.W.

    2013-10-15

    Highlights: • High heat flux, high density plasmas in a highly accessible linear plasma device. • Plasma exposure of targets of different sizes under selectable plasma beam angles. • Dedicated plasma and surface diagnostics. • Differential vacuum pumping system. -- Abstract: The construction phase of the linear plasma generator Magnum-PSI at the FOM institute DIFFER has been completed and the facility has been officially opened in March 2012. The scientific program to gain more insight in the plasma–wall interactions relevant for ITER and future fusion reactors has started. In Magnum-PSI, targets of a wide range of materials and shapes can be exposed to high particle, high heat flux plasmas (>10{sup 24} ions m{sup −2} s{sup −1}; >10 MW/m{sup 2}). For magnetization of the plasma, oil-cooled electromagnets are temporarily installed to enable pulsed operation until the device is upgraded with a superconducting magnet. The magnets generate a field of up to 1.9 T close to the plasma source for a duration of 6 s. Longer exposure times are available for lower field settings. Plasma characterizations were done with a variety of gases (H, D, He, Ne and Ar) to determine the machine performance and prepare for subsequent scientific experiments. Thomson scattering and optical emission spectroscopy were used to determine the plasma parameters while infrared thermography and target calorimetry were used to determine the power loads to the surface. This paper reports on the status of Magnum-PSI and its diagnostic systems. In addition, an overview of the plasma parameters that can be achieved in the present state will be given.

  11. Products of DNA, protein and lipid oxidative damage in relation to vitamin C plasma concentration.

    Science.gov (United States)

    Krajcovicová-Kudlácková, M; Dusinská, M; Valachovicová, M; Blazícek, P; Pauková, V

    2006-01-01

    Oxidative stress plays an important role in the pathogenesis of numerous chronic age-related free radical-induced diseases. Improved antioxidant status minimizes oxidative damage to DNA, proteins, lipids and other biomolecules. Diet-derived antioxidants such as vitamin C, vitamin E, carotenoids and related plant pigments are important in antioxidative defense and maintaining health. The results of long-term epidemiological and clinical studies suggest that protective vitamin C plasma concentration for minimum risk of free radical disease is higher than 50 micromol/l. Products of oxidative damage to DNA (DNA strand breaks with oxidized purines and pyrimidines), proteins (carbonyls) and lipids (conjugated dienes of fatty acids, malondialdehyde) were estimated in a group of apparently healthy adult non-smoking population in dependence on different vitamin C plasma concentrations. Under conditions of protective plasma vitamin C concentrations (>50 micromol/l) significantly lower values of DNA, protein and lipid oxidative damage were found in comparison with the vitamin C-deficient group (fruit and vegetable consumption (leading to higher vitamin C intake and higher vitamin C plasma concentrations) on oxidation of DNA, proteins and lipids is also expressed by an inverse significant correlation between plasma vitamin C and products of oxidative damage. The results suggest an important role of higher and frequent consumption of protective food (fruit, vegetables, vegetable oils, nuts, seeds and cereal grains) in prevention of free radical disease.

  12. Cool oxygen plasma oxidation of the organic matter of coal

    Energy Technology Data Exchange (ETDEWEB)

    Korobetskii, I.A.; Nazimov, S.A.; Romanchuk, V.V. [COAL-C Ltd., Kemerovo (Russian Federation)

    1997-12-31

    Oxidation of the sapropelitic coals has been carried out by cool oxygen plasma. The changes in concentration of oxygen- and hydrogen-containing groups of organic matter were observed by photoacoustic FTIR-spectroscopy during the cool oxygen plasma oxidation (COPO). The accumulation of oxygen-containing bands, such as C-O and O-H, during COPO was shown. The complete elimination of aromatic and aliphatic structure occurred in first two hours of oxidation. (orig.)

  13. Effect of Dietary n-3 Polyunsaturated Fatty Acids on Oxidant/Antioxidant Status in Macrosomic Offspring of Diabetic Rats

    Directory of Open Access Journals (Sweden)

    B. Guermouche

    2014-01-01

    Full Text Available The aim of this work was to determine the effect of dietary n-3 PUFA on oxidant/antioxidant status, in vitro very low and low density lipoprotein (VLDL-LDL, and VLDL-LDL-fatty acid composition in macrosomic pups of diabetic mothers. We hypothesized that n-3 PUFA would improve oxidative stress in macrosomia. Diabetes was induced in female Wistar rats fed with the ISIO diet (control or with the EPAX diet (enriched in n-3 PUFAs, by streptozotocin. The macrosomic pups were killed at birth (day 0 and at adulthood (day 90. Lipid parameters and VLDL-LDL-fatty acid composition were investigated. The oxidant/antioxidant status was determined by measuring plasma oxygen radical absorbance capacity (ORAC, hydroperoxides, carbonyl proteins, and VLDL-LDL oxidation. Macrosomic rats of ISIO fed diabetic mothers showed an increase in plasma and VLDL-LDL-triglycerides and VLDL-LDL-cholesterol levels and altered VLDL-LDL-fatty acid composition. Plasma ORAC was low with high hydroperoxide and carbonyl protein levels. The in vitro oxidizability of VLDL-LDL was enhanced in these macrosomic rats. The EPAX diet corrected lipid parameters and improved oxidant/antioxidant status but increased VLDL-LDL susceptibility to oxidation. Macrosomia is associated with lipid abnormalities and oxidative stress. n-3 PUFA exerts favorable effects on lipid metabolism and on the oxidant/antioxidant status of macrosomic rats. However, there are no evident effects on VLDL-LDL oxidation.

  14. Studies on Nitrogen Oxides Removal Using Plasma Assisted Catalytic Reactor

    Institute of Scientific and Technical Information of China (English)

    V. Ravi; Young Sun Mok; B. S. Rajanikanth; Ho-Chul Kang

    2003-01-01

    An electric discharge plasma reactor combined with a catalytic reactor was studied for removing nitrogen oxides. To understand the combined process thoroughly, discharge plasma and catalytic process were separately studied first, and then the two processes were combined for the study. The plasma reactor was able to oxidize NO to NO2 well although the oxidation rate decreased with temperature. The plasma reactor alone did not reduce the NOx (NO+NO2)level effectively, but the increase in the ratio of NO2 to NO as a result of plasma discharge led to the enhancement of NOx removal efficiency even at lower temperatures over the catalyst surface (V2O5-WOa/TiO2). At a gas temperature of 100℃, the NOx removal efficiency obtained using the combined plasma catalytic process was 88% for an energy input of 36 eV/molecule or 30 J/1.

  15. Plasma enhanced vortex fluidic device manipulation of graphene oxide.

    Science.gov (United States)

    Jones, Darryl B; Chen, Xianjue; Sibley, Alexander; Quinton, Jamie S; Shearer, Cameron J; Gibson, Christopher T; Raston, Colin L

    2016-08-25

    A vortex fluid device (VFD) with non-thermal plasma liquid processing within dynamic thin films has been developed. This plasma-liquid microfluidic platform facilitates chemical processing which is demonstrated through the manipulation of the morphology and chemical character of colloidal graphene oxide in water.

  16. Magnesium Status and Its Association with Oxidative Stress in Obese Women.

    Science.gov (United States)

    Morais, Jennifer Beatriz Silva; Severo, Juliana Soares; de Oliveira, Ana Raquel Soares; Cruz, Kyria Jayanne Clímaco; da Silva Dias, Thaline Milany; de Assis, Régina Célia; Colli, Célia; do Nascimento Marreiro, Dilina

    2017-02-01

    The aim of this study was to assess the relationship between magnesium status and oxidative stress in obese and nonobese women. This cross-sectional study included 83 women, aged between 20 and 50 years, who were divided into two groups: the obese group (n = 31) and the control group (n = 52). The control group was age-matched with the obese group. Magnesium intake was monitored using 3-day food records and NutWin software version 1.5. The plasma and erythrocyte magnesium concentrations were determined by flame atomic absorption spectrophotometry. Plasma levels of thiobarbituric acid reactive substances (TBARS) were determined as biomarkers for lipid peroxidation and therefore of oxidative stress. The mean values of the magnesium content in the diet were found to be lower than those recommended, though there was no significant difference between groups (p > 0.05). The mean concentrations of plasma and erythrocyte magnesium were within the normal range, with no significant difference between groups (p > 0.05). The mean concentration of plasma TBARS was higher in obese woman, and the difference between the groups was statistically different (p magnesium and plasma TBARS in the obese group (p = 0.021). Obese patients ingest low dietary magnesium content, which does not seem to affect the plasma and erythrocyte concentrations of the mineral. The study showed a negative correlation between erythrocyte magnesium concentrations and plasma TBARS, suggesting the influence of magnesium status on the parameters of oxidative stress in obese women.

  17. Oxidation of vanadium metal in oxygen plasma and their characterizations

    Directory of Open Access Journals (Sweden)

    Rabindar Kumar Sharma

    2015-09-01

    Full Text Available In this report, the role of oxygen plasma on oxidation of vanadium (V metal and the volatilization of its oxides has been studied as a function of source (V metal strip temperature (Tss and oxygen partial pressure (PO2. The presence of O2-plasma not only enhances the oxidation rate but also ficilitates in transport of oxide molecules from metal to substrate, as confirmed by the simultanous deposition of oxide film onto substrate. Both the oxidized metal strips and oxide films deposited on substrates are characterized separately. The structural and vibrational results evidence the presence of two different oxide phases (i.e. orthorhombic V2O5 and monocilinic V O2 in oxide layers formed on V metal strips, whereas the oxide films deposited on substrates exhibit only orthorhombic phase (i.e. V2O5. The decrease in peak intensities recorded from heated V metal strips on increasing Tss points out the increment in the rate of oxide volatilization, which also confirms by the oxide layer thickness measurements. The SEM results show the noticeable surface changes on V-strips as the function of Tss and PO2 and their optimum values are recorded to be 500   ˚ C and 7.5 × 10−2 Torr, respectively to deposit maximum thick oxide film on substrate. The formation of microcracks on oxidized V-strips, those responsible to countinue oxidation is also confirmed by SEM results. The compositional study of oxide layers formed on V-strips, corroborates their pureness and further assures about the existence of mixed oxide phases. The effect of oxygen partial pressure on oxidation of V-metal has also been discussed in the present report. All the results are well in agreement to each other.

  18. The contribution of Nikola Tesla to plasma physics and current status of plasmas that he studied

    Directory of Open Access Journals (Sweden)

    Petrović Zoran Lj.

    2006-01-01

    Full Text Available One of the main Interests in science of Nikola Tesla were gas discharges plasmas, their application in lighting and in production of ozone as well as their role in conduction of electricity through the atmosphere. In particular Tesla is well known as the first person to produce rf plasmas. Such plasmas in the present day constitute the main technology required to produce integrated circuits (IC and have been essential in the revolution that resulted from IC technologies. In addition Tesla participated in studies of arcs especially arcs used as a source of light, corona discharges required to induce plasma chemical reactions and produce ozone and was involved in various aspects of gas breakdown and gaseous dielectrics. His ideas, level of his understanding and current status of these fields are discussed in this review.

  19. Oxidation efficiency of elemental mercury in two DBD plasma reactors

    Science.gov (United States)

    Jiang, Yuze; An, Jiutao; Shang, Kefeng; Jiang, Diwen; Li, Jie; Lu, Na; Wu, Yan

    2013-03-01

    Configuration of plasma reactors influences the generation of active species including the energized electrons, active radicals and the distribution of active species in reactor, and thus influences the removal efficiency of pollutants. Oxidation efficiency of elemental mercury (Hg0) in two different DBD plasma reactors was studied in this paper. One plasma reactor is a surface discharge reactor (SDR) with a spiral stainless steel thread as the high voltage electrode, and the other plasma reactor is a concentric cylinder type DBD reactor (CCDR) with a copper screw rod as the high voltage electrode. The oxidation efficiencies of Hg0 under different specific energy density (SED), oxygen content, flue gas residence time and the temperature of flue gas indicate that SDR had a better performance than CCDR in oxidation of Hg0, which can be attributed to the higher generation efficiency of ozone in SDR than in CCDR.

  20. The Oxidant and Antioxidant Status in Pityriasis Rosea

    Science.gov (United States)

    Emre, Selma; Akoglu, Gulsen; Metin, Ahmet; Demirseren, Duriye Deniz; Isikoglu, Semra; Oztekin, Aynure; Erel, Ozcan

    2016-01-01

    Background: Pityriasis rosea (PR) is usually an asymptomatic and self-limiting papulosquamous skin disease with acute onset. The etiology has not been clarified yet. Recently, increased oxidative stress was found to play a role in etiopathogenesis of multiple cutaneous diseases with T cell-mediated immune response. However, there are no studies demonstrating the oxidative stress status in PR. Aim: The aim of the study is to determine the status of oxidative stress (OS) and paraoxonase (PON) 1/arylesterase enzyme activities in PR. Materials and Methods: Study included 51 patients with active PR lesions, and 45 healthy volunteers. Serum levels of total oxidant status (TOS), total antioxidant status (TAS), and PON1/arylesterase (ARES) activity were determined and oxidative stress index (OSI) was calculated in all patients and controls. Results: TAS levels and ARES activities in the patient group were significantly lower than the control group. On the other hand, TOS and OSI levels were significantly higher in patients compared with controls. There was no significant correlation between the duration of disease and TAS, TOS, OSI levels, and ARES activities. Conclusion: A systemic oxidative stress exists in PR, which suggests that OS may be involved in the etiopathogenesis of disease. PMID:26955119

  1. The oxidant and antioxidant status in pityriasis rosea

    Directory of Open Access Journals (Sweden)

    Selma Emre

    2016-01-01

    Full Text Available Background: Pityriasis rosea (PR is usually an asymptomatic and self-limiting papulosquamous skin disease with acute onset. The etiology has not been clarified yet. Recently, increased oxidative stress was found to play a role in etiopathogenesis of multiple cutaneous diseases with T cell-mediated immune response. However, there are no studies demonstrating the oxidative stress status in PR. Aim: The aim of the study is to determine the status of oxidative stress (OS and paraoxonase (PON 1/arylesterase enzyme activities in PR. Materials and Methods: Study included 51 patients with active PR lesions, and 45 healthy volunteers. Serum levels of total oxidant status (TOS, total antioxidant status (TAS, and PON1/arylesterase (ARES activity were determined and oxidative stress index (OSI was calculated in all patients and controls. Results: TAS levels and ARES activities in the patient group were significantly lower than the control group. On the other hand, TOS and OSI levels were significantly higher in patients compared with controls. There was no significant correlation between the duration of disease and TAS, TOS, OSI levels, and ARES activities. Conclusion: A systemic oxidative stress exists in PR, which suggests that OS may be involved in the etiopathogenesis of disease.

  2. Hypochlorite-induced oxidation of proteins in plasma

    DEFF Research Database (Denmark)

    Hawkins, C L; Davies, Michael Jonathan

    1999-01-01

    Activated phagocyte cells generate hypochlorite (HOCl) via the release of H2O2 and the enzyme myeloperoxidase. Plasma proteins are major targets for HOCl, although little information is available about the mechanism(s) of oxidation. In this study the reaction of HOCl (at least 50 microM) with dil......Activated phagocyte cells generate hypochlorite (HOCl) via the release of H2O2 and the enzyme myeloperoxidase. Plasma proteins are major targets for HOCl, although little information is available about the mechanism(s) of oxidation. In this study the reaction of HOCl (at least 50 micro......M) with diluted fresh human plasma has been shown to generate material that oxidizes 5-thio-2-nitrobenzoic acid; these oxidants are believed to be chloramines formed from the reaction of HOCl with protein amine groups. Chloramines have also been detected with isolated plasma proteins treated with HOCl. In both....... These results are consistent with protein-derived chloramines, and the radicals derived from them, as contributing agents in HOCl-induced plasma protein oxidation....

  3. Green tea extract only affects markers of oxidative status postprandially: lasting antioxidant effect of flavonoid-free diet

    DEFF Research Database (Denmark)

    Young, J.F.; Dragsted, Lars Ove; Haraldsdottir, J.

    2002-01-01

    Epidemiological studies suggest that foods rich in flavonoids might reduce the risk of cardiovascular disease and cancer. The objective of the present study was to investigate the effect of green tea extract (GTE) used as a food antioxidant on markers of oxidative status after dietary depletion...... in flavonoids. GTE intervention increased plasma antioxidant capacity from 1.35 to 1.56 (P...

  4. Acute Exercise Increases Plasma Total Antioxidant Status and Antioxidant Enzyme Activities in Untrained Men

    Directory of Open Access Journals (Sweden)

    C. Berzosa

    2011-01-01

    Full Text Available Antioxidant defences are essential for cellular redox regulation. Since free-radical production may be enhanced by physical activity, herein, we evaluated the effect of acute exercise on total antioxidant status (TAS and the plasma activities of catalase, glutathione reductase, glutathione peroxidase, and superoxide dismutase and its possible relation to oxidative stress resulting from exercise. Healthy untrained male subjects (=34 performed three cycloergometric tests, including maximal and submaximal episodes. Venous blood samples were collected before and immediately after each different exercise. TAS and enzyme activities were assessed by spectrophotometry. An increase of the antioxidant enzyme activities in plasma was detected after both maximal and submaximal exercise periods. Moreover, under our experimental conditions, exercise also led to an augmentation of TAS levels. These findings are consistent with the idea that acute exercise may play a beneficial role because of its ability to increase antioxidant defense mechanisms through a redox sensitive pathway.

  5. Postprandial oxidative stress: influence of sex and exercise training status.

    Science.gov (United States)

    Bloomer, Richard J; Ferebee, David E; Fisher-Wellman, Kelsey H; Quindry, John C; Schilling, Brian K

    2009-12-01

    An individual's sex and exercise training status may influence oxidative stress. No study has compared postprandial oxidative stress in exercise-trained and untrained men and women. To compare oxidative stress biomarkers and triglycerides (TAG) in 16 trained and 16 untrained men and women after ingestion of a high-fat meal. Blood samples were collected before, and at 1, 2, 4, and 6 h after intake of a high-fat meal and analyzed for Trolox-equivalent antioxidant capacity (TEAC), malondialdehyde, hydrogen peroxide, xanthine oxidase activity, protein carbonyls (PC), and TAG. Area under the curve was calculated for each variable. Sex main effects were noted for all variables (P 0.05), with higher values for men compared with women. A training status main effect was noted for TEAC (P = 0.02), with higher values for trained compared with untrained subjects. No interaction effects were noted (P > 0.05). Regression analysis indicated that TAG explained the greatest degree of variability for oxidative stress variables, and premeal TAG best predicted the TAG response to feeding (R(2) = 0.50). With the exception of TEAC, for which higher values were noted for trained compared with untrained subjects, our findings indicate that sex, not exercise training status, influences postprandial oxidative stress. Specifically, women experience a significantly lower oxidative stress response to feeding compared with men. This seems mediated in part by the TAG response to feeding.

  6. Age-specific oxidative status and the expression of pre- and postcopulatory sexually selected traits in male red junglefowl, Gallus gallus.

    Science.gov (United States)

    Noguera, Jose C; Dean, Rebecca; Isaksson, Caroline; Velando, Alberto; Pizzari, Tommaso

    2012-09-01

    Oxidative stress is emerging as a key factor underpinning life history and the expression of sexually selected traits. Resolving the role of oxidative stress in life history and sexual selection requires a pluralistic approach, which investigates how age affects the relationship between oxidative status (i.e., antioxidants and oxidative damage) and the multiple traits contributing to variation in reproductive success. Here, we investigate the relationship between oxidative status and the expression of multiple sexually selected traits in two-age classes of male red junglefowl, Gallus gallus, a species which displays marked male reproductive senescence. We found that, irrespective of male age, both male social status and comb size were strongly associated with plasma oxidative status, and there was a nonsignificant tendency for sperm motility to be associated with seminal oxidative status. Importantly, however, patterns of plasma and seminal antioxidant levels differed markedly in young and old males. While seminal antioxidants increased with plasma antioxidants in young males, the level of seminal antioxidants remained low and was independent of plasma levels in old males. In addition, old males also accumulated more oxidative damage in their sperm DNA. These results suggest that antioxidant allocation across different reproductive traits and somatic maintenance might change drastically as males age, leading to age-specific patterns of antioxidant investment.

  7. Initial and post-treatment total oxidant-antioxidant status and oxidative stress index in male patients with manic episode.

    Science.gov (United States)

    Kalelioglu, Tevfik; Genc, Abdullah; Karamustafalioglu, Nesrin; Tasdemir, Akif; Can Gungor, Ferda; Cansiz, Alparslan; Incir, Said; Cem Ilnem, M; Emul, Murat

    2014-08-15

    We investigated serum total oxidative and anti-oxidative status in manic patients. Group1 was formed as ECT+antipsychotic, group2 was antipsychotic and healthy volunteers as group3. The anti-oxidative status was significantly lower in group1 than group3. No significant change was found between pre and post-treatment oxidative and anti-oxidative status, whereas significantly increased oxidative stress index has been found in group2. Total anti-oxidative status in manic states seems to be inadequate which remains to be maintained after the treatment. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  8. Oxidation Degradation of Aqueous Carbofuran Induced by Low Temperature Plasma

    Science.gov (United States)

    Pu, Lumei; Gao, Jinzhang; Hu, Yusen; Liang, Huiguang; Xiao, Wen; Wang, Xingmin

    2008-06-01

    The oxidative degradation of aqueous carbofuran, a heavily used toxic carbamate insecticide by low temperature plasma, was investigated. The results show that the treatment efficiency increases with the increase in initial concentration. Raising the treatment temperature and changing the pH value can result in enhanced degradation of carbofuran in solution. The results also show that low temperature plasma treatment can effectively remove chemical oxygen demand (COD) of carbofuran in the solution.

  9. Oxidation Degradation of Aqueous Carbofuran Induced by Low Temperature Plasma

    Institute of Scientific and Technical Information of China (English)

    PU Lumei; GAO Jinzhang; HU Yusen; LIANG Huiguang; XIAO Wen; WANG Xingmin

    2008-01-01

    The oxidative degradation of aqueous carbofuran, a heavily used toxic carbamate insecticide by low temperature plasma, was investigated. The results show that the treatment efficiency increases with the increase in initial concentration. Raising the treatment temperature and changing the pH value can result in enhanced degradation of carbofuran in solution. The results also show that low temperature plasma treatment can effectively remove chemical oxygen demand (COD) of carbofuran in the solution.

  10. Plasma diagnostics during magnetron sputtering of aluminum doped zinc oxide

    DEFF Research Database (Denmark)

    Stamate, Eugen; Crovetto, Andrea; Sanna, Simone

    2016-01-01

    Plasma parameters during magnetron sputtering of aluminum-doped zinc oxide are investigated with optical emission spectroscopy, electrostatic probes and mass spectrometry with the aim of understanding the role of negative ions of oxygen during the film growth and improving the uniformity of the f......Plasma parameters during magnetron sputtering of aluminum-doped zinc oxide are investigated with optical emission spectroscopy, electrostatic probes and mass spectrometry with the aim of understanding the role of negative ions of oxygen during the film growth and improving the uniformity...

  11. Plasma post oxidation of nitrocarburized AISI 4140 steel

    Institute of Scientific and Technical Information of China (English)

    LEE Insup

    2006-01-01

    Plasma nitrocarburizing and plasma oxidizing treatments were performed to improve the wear and corrosion resistance of AISI 4140 steel.Plasma nitrocarburizing was conducted for 3 h at 570 ℃ in the nitrogen, hydrogen and methane atmosphere to produce the ε-Fe2-3(N,C) phase.It was found that the compound layer produced by plasma nitrocarburising was predominantly composed of ε-phase, with a small proportion of γ'-Fe4(N,C) phase.The thickness of the compound layer was about 10 μm and the diffusion layer was about 300 μm in thickness, respectively.Plasma post oxidation was performed on the nitrocarburized samples with various oxygen/hydrogen ratio at a constant temperature of 500 ℃ for 1 h.The very thin magnetite (Fe3O4) layer 1-2 μm in thickness on top of the compound layer was obtained by plasma post oxidation.It was confirmed that the corrosion characteristics of the nitrocarburized compound layer can be further improved by the application of the superficial magnetite layer.

  12. Effects of Dietary Supplementation of Some Antioxidants on Liver Antioxidant Status and Plasma Biochemistry Parameters of Heat-Stressed Quail

    Directory of Open Access Journals (Sweden)

    Senay Sarıca

    2017-07-01

    Full Text Available This study aimed to compare the dietary supplementation of oleuropein (O and α-tocopherol acetate (TA alone or with organic selenium (Se on liver antioxidant status and some plasma biochemistry parameters in Japanese quails reared under heat stress (HS. A total of 800, two-weeks old quails were kept in wire cages in the temperature-controlled rooms at either 22°C or 34°C for 8 h/d and fed on a basal diet (NC or the diets supplemented with TA (TA200 or O (O200 at 200 mg/kg alone or with OSe (TA200+OSe and O200+OSe to the NC diet. HS decreased the total antioxidant status (TAS and increased the total oxidative stress (TOS and oxidative stress index (OSI of liver compared to thermoneutral temperature (TN. The TA200, O200, TA200+OSe and O200+OSe diets increased TAS and decreased TOS of liver compared to those of quails fed NC. OSI was decreased by the TA200, O200 and TA200+OSe diets compared to NC and O200+OSe diets. HS reduced plasma albumin (A and total protein (TP concentrations, on the other hand, increased plasma glucose (G, total cholesterol (CHO and triglyceride (TG levels compared to TN. The TA200, O200, TA200+OSe and O200+OSe diets reduced plasma total CHO and TG levels and increased plasma A level. The TA200 and TA200+OSe diets reduced plasma G level and increased plasma TP levels compared to those of quails fed the other diets. In conclusion, dietary supplementation of vitamin E and oleuropein alone or with organic selenium is necessary to remove the negative effects of heat stress on liver antioxidant status and some plasma parameters of quails.

  13. Physical Training Status Determines Oxidative Stress and Redox Changes in Response to an Acute Aerobic Exercise

    Directory of Open Access Journals (Sweden)

    Farnaz Seifi-skishahr

    2016-01-01

    Full Text Available Objective. To assess the influence of different physical training status on exercise-induced oxidative stress and changes in cellular redox state. Methods. Thirty male subjects participated in this study and were assigned as well-trained (WT, moderately trained (MT, and untrained (UT groups. The levels of cortisol, creatine kinase, plasma reduced glutathione to oxidized glutathione (GSH/GSSG, cysteine/cystine (Cys/CySS, and GSH/GSSG ratio in red blood cells (RBCs were measured immediately and 10 and 30 min after exercise. Results. Following the exercise, plasma GSH/GSSG (p=0.001 and Cys/CySS (p=0.005 were significantly reduced in all groups. Reduction in plasma GSH/GSSG ratio in all groups induced a transient shift in redox balance towards a more oxidizing environment without difference between groups (p=0.860, while RBCs GSH/GSSG showed significant reduction (p=0.003 and elevation (p=0.007 in UT and MT groups, respectively. The highest level of RBCs GSH/GSSG ratio was recorded in MT group, and the lowest one was recorded in the WT group. Conclusion. Long term regular exercise training with moderate intensity shifts redox balance towards more reducing environment, versus intensive exercise training leads to more oxidizing environment and consequently development of related diseases.

  14. Gate oxide punching thru mechanism in plasma dry etching

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The punching thru mechanism of gate oxide (thickness about 15A) was investi- gated. Because of the thin thickness of gate oxide, gate oxide punching thru may easily happen during the plasma process. It was found that what caused the punching thru was not only the selectivity of poly-silicon/oxide but also the pattern topography. We used the basic SRAM pattern to check this topography effect, and found that gate oxide located at the narrow spacing of two parallel serpentine lines was the most easily punched thru. What caused the topography effect was the starvation of oxygen in these places which were induced by the residue of poly-silicon and enhanced by electron shading effect. So, to solve the issue of gate oxide punching thru, firstly the selectivity should be enough, secondly we should pay attention to the etching pattern topography.

  15. Study of positive and negative plasma catalytic oxidation of ethylene.

    Science.gov (United States)

    Van Wesenbeeck, K; Hauchecorne, B; Lenaerts, S

    2017-06-01

    The effect of introducing a photocatalytically active coating inside a plasma unit is investigated. This technique combines the advantages of high product selectivity from catalysis and the fast start-up from plasma technology. In this study, a preselected TiO2 coating is applied on the collector electrode of a DC corona discharge unit as non-thermal plasma reactor, in order to study the oxidation of ethylene. For both positive and negative polarities an enhanced mineralization is observed while the formation of by-products drastically decreases. The plasma catalytic unit gave the best results when using negative polarity at a voltage of 15 kV. This shows the potential of plasma catalysis as indoor air purification technology.

  16. Thermal Plasma Synthesis of Superparamagnetic Iron Oxide Nanoparticles

    NARCIS (Netherlands)

    Lei, P.Y.; Boies, A.M.; Calder, S.A.; Girshick, S.L.

    2012-01-01

    Superparamagnetic iron oxide nanoparticles were synthesized by injecting ferrocene vapor and oxygen into an argon/helium DC thermal plasma. Size distributions of particles in the reactor exhaust were measured online using an aerosol extraction probe interfaced to a scanning mobility particle sizer,

  17. New iodo-acetamido cyanines for labeling cysteine thiol residues. A strategy for evaluating plasma proteins and their oxido-redox status.

    Science.gov (United States)

    Bruschi, Maurizio; Grilli, Stefano; Candiano, Giovanni; Fabbroni, Serena; Della Ciana, Leopoldo; Petretto, Andrea; Santucci, Laura; Urbani, Andrea; Gusmano, Rosanna; Scolari, Francesco; Ghiggeri, Gian Marco

    2009-01-01

    Two new iodoacetamide-substituted cyanines, C3NIASO3 and C5NIASO3, were synthesized starting from hemicyanine and were utilized for labeling plasma proteins. Specificity, sensitivity and feasibility for SH residues was tested utilizing an equimolar mixture of standard proteins and with normal plasma. Oxidized plasma proteins following H(2)O(2 )exposure and plasma from patients with focal glomerulosclerosis were analyzed as models of altered protein oxido-redox status. Following optimization of the assay (dye/protein ratio, pH), C3NIASO3 and C5NIASO3 gave a sensitivity slightly better than N-hydroxysuccinimidyl dyes for plasma proteins and were successfully employed for differential display electrophoresis (DIGE). Twenty-nine proteins were detected in normal plasma after 2-DE while less proteins were detected in plasma of patients with glomerulosclerosis. Following massive 'in vitro' oxidation with H(2)O(2), C3NIASO3 and C5NIASO3 failed to detect any residual SH, implicating massive oxidation. In conclusion, this study describes the synthesis of two new iodoacetamide cyanines that can be utilized for the analysis of plasma proteins with 2-DE and DIGE. They are also indicated for the definition of the oxido-redox status of proteins and were successfully utilized to extend the analysis of oxidation damage in patients with glomerulosclerosis.

  18. On the methodological limitations of detecting oxidative stress: effects of paraquat on measures of oxidative status in greenfinches.

    Science.gov (United States)

    Meitern, Richard; Sild, Elin; Kilk, Kalle; Porosk, Rando; Hõrak, Peeter

    2013-07-15

    Oxidative stress (OS) is widely believed to be responsible for the generation of trade-offs in evolutionary ecology by means of constraining investment into a number of components of fitness. Yet, progress in understanding the true role of OS in ecology and evolution has remained elusive. Interpretation of current findings is particularly hampered by the scarcity of experiments demonstrating which of the many available parameters of oxidative status respond most sensitively to and are relevant for measuring OS. We addressed these questions in wild-caught captive greenfinches (Carduelis chloris) by experimental induction of OS by administration of the pro-oxidant compound paraquat with drinking water. Treatment induced 50% mortality, a significant drop in body mass and an increase in oxidative DNA damage and glutathione levels in erythrocytes among the survivors of the high paraquat (0.2 g l(-1) over 7 days) group. Samples taken 3 days after the end of paraquat treatment showed no effect on the peroxidation of lipids (plasma malondialdehyde), carbonylation of proteins (in erythrocytes), parameters of plasma antioxidant protection (total antioxidant capacity and oxygen radical absorbance), uric acid or carotenoids. Our findings of an increase in one marker of damage and one marker of protection from the multitude of measured variables indicate that detection of OS is difficult even under the most stringent experimental induction of oxidative insult. We hope that this study highlights the need for reconsideration of over-simplistic models of OS and draws attention to the limitations of detection of OS due to time-lagged and hormetic upregulation of protective mechanisms. This study also underpins the diagnostic value of measurement of oxidative damage to DNA bases and assessment of erythrocyte glutathione levels.

  19. Consumption of Argan Oil Improves Anti-Oxidant and Lipid Status in Hemodialysis Patients.

    Science.gov (United States)

    Eljaoudi, Rachid; Elkabbaj, Driss; Bahadi, Abdelali; Ibrahimi, Azeddine; Benyahia, Mohammed; Errasfa, Mourad

    2015-10-01

    Virgin Argan oil (VAO) is of interest in oxidative stress and lipid profile because of its fat composition and antioxidant compounds. We investigated the effect of VAO consumption on lipid profile and antioxidant status in hemodialysis patients after a 4-week period of consumption. In a crossover, controlled trial, 37 patients (18 men, 19 women) with end-stage renal disease on maintenance hemodialysis, were randomly assigned to a 4-week VAO diet. Fasting plasma lipids, vitamin E and oxidized LDL (ox-LDL) were analyzed. Malondialdehyde (MDA) was determined before and after hemodialysis session. There was no significant change in serum total cholesterol and ox-LDL. However, VAO consumption decreased the levels of triglyceride (p = 0.03), total cholesterol (p = 0.02) and low-density lipoprotein (p = 0.03) and increased the levels of high-density lipoprotein (p = 0.01). Plasma vitamin E contents significantly increased from baseline only in VAO-group (p < 0.001). Hemodialysis session increased MDA levels, but the increase in VAO group was less than in control group. VAO consumption improved lipid profile and oxidative stress status in hemodialysis patients. Copyright © 2015 John Wiley & Sons, Ltd.

  20. Association between oxidative stress and nutritional status in the elderly.

    Science.gov (United States)

    Moreira, Priscila Lucelia; Villas Boas, Paulo Jose Fortes; Ferreira, Ana Lucia Anjos

    2014-01-01

    Ageing is a dynamic and progressive process that is characterized by the occurrence of morphological, biochemical, functional and psychological changes in the organism. The aim of the present article is to provide updated concepts on oxidative stress, covering its importance in aging, as well as nutritional status and supplementation with antioxidants (substances that prevent or attenuate oxidation of oxidizable substrates, such as lipids, proteins, carbohydrates and deoxyribonucleic acid) in the geriatric population. Evidence suggests that there is an inverse relationship between oxidative stress and nutritional status in elderly individuals. Although an increase in oxidative stress in chronic diseases associated with aging has been proven, such as Parkinson's disease and Alzheimer's disease, up to now there has been no consistent clinical evidence proving the efficiency of supplementation with antioxidants against oxidative stress. In this context, supplementation is not recommended. On the other hand, the elderly should be encouraged to eat antioxidant foods, such as fruits and vegetables. Maintaining a normal weight (body mass index between 23 and 28 Kg/m(2)) should also be stimulated.

  1. Status and prospects of intermediate temperature solid oxide fuel cells

    Institute of Scientific and Technical Information of China (English)

    Bangwu Liu; Yue Zhang

    2008-01-01

    Compared with conventional electric power generation systems, the solid oxide fuel cell (SOFC) has many advantages because of its unique features. High temperature SOFC has been successfully developed to its commercial applications, but it still faces many problems which hamper large-scale commercial applications of SOFC. To reduce the cost of SOFC, intermediate tem-perature solid oxide fuel cell (IT-SOFC) is presently under rapid development. The status of IT-SOFC was reviewed with emphasis on discussion of their component materials.

  2. Evaluation of total antioxidant status, total oxidant status and oxidative stress index in patients with alopecia areata.

    Science.gov (United States)

    Motor, Sedat; Ozturk, Sahin; Ozcan, Oguzhan; Gurpinar, Ahmet Burak; Can, Yesim; Yuksel, Rana; Yenin, Julide Zehra; Seraslan, Gamze; Ozturk, O Hasan

    2014-01-01

    In this study, we aimed to evaluate total oxidative stress and total antioxidant capacity in serum samples from patients with Alopesia Areata (AA) in our laboratory conditions. In this study, 46 subjects with AA (26 females, 20 males) and the control subjects of 36 (20 females, 16 males) age- and sex-matched healthy volunteers from our hospital staffs were enrolled (the mean age was 23.7 ± 11.0 years). Blood samples were obtained following an overnight fasting state, and were collected on ice at 4°C. The serum samples were separated from the cells by centrifugation at 3000 rpm for 15 min and were stored at -80°C and used for the analysis of the Total Antioxidant Status (TAS) and Total Oxidant Status (TOS). Total Antioxidant Status (TAS) and Total Oxidant Status (TOS), Oxidative Stress Index (OSI) (TOS/TAS) levels of AA patients were 1.4777 ± 0.1986; 9.7490 ± 6.0445; 0.6593 ± 0.4069 respectively. TAS; TOS; OSİ (TOS/TAS) levels of controls were 1.4028 ± 0.1687; 9.4627 ± 4.2781; 0.6875 ± 0.3232 respectively. TAS, TOS and OSİ levels showed no significant difference between the control and AA group (p > 0.05). Future studies about AA pathogenesis should be based not only on oxidant/antioxidant balance but also on several other factors. Because it was observed that the disease showed recurrence in different situations. Since the selection criteria of patients is affected from disease severity and environmental and genetical factors, multicentric studies with better sampled patient population and higher patient number is required.

  3. Plasma antioxidant status and motor features in de novo Chinese Parkinson's disease patients.

    Science.gov (United States)

    Yuan, Yongsheng; Tong, Qing; Zhang, Li; Jiang, Siming; Zhou, Hong; Zhang, Rui; Zhang, Shu; Xu, Qinrong; Li, Daqian; Zhou, Xiaobin; Ding, Jian; Zhang, Kezhong

    2016-01-01

    This study aimed to explore plasma antioxidant status in de novo Chinese Parkinson's disease (PD) patients and investigate its relationship with specific motor features of PD. Sixty-four de novo Chinese PD patients and 40 age- and sex-matched healthy controls were recruited. Each motor feature of PD patients was assessed by unified Parkinson's disease rating scale. Plasma antioxidant status, including plasma level of glutathione (GSH) and plasma activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), was detected using enzyme-linked immunosorbent assay. The relationship between the plasma antioxidant status and motor features of PD was evaluated by Spearman's coefficient. Plasma GSH level and plasma activities of GSH-Px, CAT and SOD of PD patients were lower than those of healthy controls. Moreover, the declining activity of plasma CAT was related with the increasing mean postural instability and gait disorder (PIGD) score and growing age. In contrast, the severity of tremor was positively correlated with plasma SOD activity. Our study demonstrates that the plasma antioxidant status is impaired in de novo Chinese PD patients. The complex relationship between the plasma antioxidant status and different motor features indicates that the antioxidant mechanisms underlying tremor and PIGD of PD may be different.

  4. Applications of plasma sources for nitric oxide medicine

    Science.gov (United States)

    Vasilets, Victor; Shekhter, Anatoly; Pekshev, Alexander

    2013-09-01

    Nitric oxide (NO) has important roles in the function of many tissues and organs. Wound healing processes are always accompanying by the increase of nitric oxide concentration in wound tissue. These facts suggest a possible therapeutic use of various NO donors for the acceleration of the wound healing and treatment of other diseases. Our previous studies indicated that gaseous NO flow produced by air-plasma generators acts beneficially on the wound healing. This beneficial effect could be caused by the mechanism involving peroxynitrite as an intermediate. As a result of mobilization of various antioxidant reactions more endogenous NO molecules become available as signaling molecules. to regulate the metabolic processes in wound tissue. In this paper different air plasma sources generated therapeutic concentrations of NO are discussed. The concentration of NO and other therapeutically important gas products are estimated by thermodynamic simulation. Synergy effects of NO with other plasma components are discussed as a factor enhancing therapeutic results. Some new medical application of plasma devices are presented. Advanced Plasma Therapies Inc.

  5. Serum Copper and Plasma Protein Status in Normal Pregnancy

    Directory of Open Access Journals (Sweden)

    Nushrat Noor, Nasim Jahan, Nayma Sultana

    2012-12-01

    Full Text Available AbstractBackground: Gradual alteration of serum copper and some plasma protein levels may occur with advancement of pregnancy, which is associated with increased maternal and infant morbidity and mortality.Objective: To observe serum copper and plasma protein levels in normal pregnant women of different trimesters in order to find out their nutritional status.Methods: This cross sectional study was carried out in the Department of Physiology, Sir Salimullah Medical College (SSMC, Dhaka, between 1st January 2010 and December 2010. Ninety normal pregnant women of different trimesters with age 20-30 years were included in the study group. They were selected from Out Patient Department of Obstetrics and Gynaecology, SSMC. Age matched 30 non-pregnant women were taken as control. Serum copper level was measured by Spectrophotometric method, serum total protein and albumin levels were estimated by standard method. Statistical analysis was done by one way ANOVA, Bonferroni and Pearson’s correlation coefficient test as applicable.Results: Serum Cu levels were significantly higher in all trimesters of pregnant women compared to control. Again, this value was significantly higher in 3rd trimester than that of in 1st and 2nd trimester and also in 2nd trimester than that of in 1st trimester. In addition, mean serum total protein level was significantly lower in 3rd trimester than control but no statistically significant difference was observed among different trimesters. Again, mean serum albumin level was significantly lower in 2nd and 3rd trimester than 1st trimester and control. In addition, serum Cu concentration showed significant positive correlation with different trimesters of gestation.Conclusion: This study reveals that hypercupremia along with hypoproteinemia occur in pregnant women from 1st to 3rd trimester of gestation. This gradual alteration of micro and macronutrients become more profound with advancement of pregnancy.

  6. Status of Research on Application of High Purity Rare Earth Oxides in Solid Oxide Fuel Cells

    Institute of Scientific and Technical Information of China (English)

    Ma Zhihong; Qiu Jufeng

    2004-01-01

    The solid oxide fuel cell (SOFC) is a high-efficient and environmentally friendly power generation system.The rare earth oxide materials are used extensively in the manufacturing of SOFC components.In particular, the CeO2doped with Gd2O3 or Sm2O3, lanthanide perovskite oxides are indispensable and key materials for developing the intermediate temperature SOFC.The research and development status of application of high purity rare earth oxides in SOFC was overviewed.The rare earth oxide-based and -doped materials were discussed for the SOFC components.Concerning the rare earth oxides applicable to SOFC, several topics were also pointed out for further researching and developing.

  7. NEW CATHODE MATERIALS FOR INERT AND OXIDIZING ATMOSPHERE PLASMA APPLICATION

    OpenAIRE

    1990-01-01

    This study has been carried out to develop new cathode materials for two types of thermionic cathode. First is concerning to the tungsten electrodes for the plasma furnace and welding torches. The second one is the electrodes for air plasma cutting torch. Tungsten electrodes activated with a single and combined additives of rare earth metal oxides, such as La2O3, Y2O3 and CeO2, are produced and pared with pure and thoriated tungsten electrode conventionally used, from the point of view of ele...

  8. Effects of protein malnutrition on oxidative status in rat brain.

    Science.gov (United States)

    Feoli, Ana M; Siqueira, Ionara R; Almeida, Lúcia; Tramontina, Ana C; Vanzella, Cláudia; Sbaraini, Sabrina; Schweigert, Ingrid D; Netto, Carlos A; Perry, Marcos L S; Gonçalves, Carlos A

    2006-02-01

    This study evaluated the effects of protein malnutrition on oxidative status in rat brain areas. We investigated various parameters of oxidative status, free radical content (dichlorofluorescein formation), indexes of damage to lipid (thiobarbituric acid-reactive substances assay), and protein damage (tryptophan and tyrosine content) in addition to total antioxidant reactivity levels and antioxidant enzyme activities of superoxide dismutase, glutathione peroxidase, and catalase in different cerebral regions (cortex, hippocampus, and cerebellum) from rats subjected to prenatal and postnatal protein malnutrition (control 25% casein and protein malnutrition 7% casein). Protein malnutrition altered various parameters of oxidative stress, especially damage to macromolecules. Free radical content was unchanged by protein malnutrition. There was an increase in levels of thiobarbituric acid-reactive substances, the index of lipid peroxidation, in the cerebellum and cerebral cortex (P brain structures (P malnutrition increased oxidative damage to lipids and proteins from the studied brain areas. These results may be an indication of an important mechanism for changes in brain development that are caused by protein malnutrition.

  9. Nonthermal plasma assisted photocatalytic oxidation of dilute benzene

    Indian Academy of Sciences (India)

    J Karuppiah; E Linga Reddy; L Sivachandiran; R Karvembu; Ch Subrahmanyam

    2012-07-01

    Oxidative decomposition of low concentrations (50-1000 ppm) of diluted benzene in air was carried out in a nonthermal plasma (NTP) dielectric barrier discharge (DBD) reactor with the inner electrode made up of stainless steel fibres (SMF) modified with transition metal oxides in such a way to integrate the catalyst in discharge zone. Typical results indicate the better performance of MnO and TiO2/MnO modified systems, which may be attributed to the in situ decomposition of ozone on the surface of MnO that may lead to the formation of atomic oxygen; whereas ultraviolet light induced photocatalytic oxidation may be taking place with TiO2 modified systems. Water vapour improved the selectivity to total oxidation.

  10. Obesity during pregnancy alters maternal oxidant balance and micronutrient status.

    Science.gov (United States)

    Sen, S; Iyer, C; Meydani, S N

    2014-02-01

    Little is known about the effect of obesity on inflammatory status in pregnant women. The objective of this study was to determine the effect of obesity on markers of inflammation, oxidative stress and micronutrient status in obese pregnant women and their infants compared with lean controls (Lc). This was a prospective case-control study. A total of 15 obese (Ob; body mass index (BMI) >30 kg m(-2)) and 15 lean (BMI 18-25 kg m(-2)) women were recruited based on prepregnancy BMI. Vitamins A, B6, C, E and 25-hydroxyvitamin D (25(OH)D), zinc, red blood cell (RBC) folate, C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-α and oxidized and reduced glutathione were measured from maternal blood between 24 and 28 weeks of gestation. Vitamins A, B6, C and E, 25(OH)D, zinc, red blood cell folate, CRP and IL-6 were measured from cord blood at delivery. Ob pregnant women have statistically significantly lower levels of vitamin B6, vitamin C, vitamin E, RBC folate, higher CRP and IL-6 levels and higher ratio of oxidized to reduced glutathione compared with Lc pregnant women. Infants born to Ob mothers did not have statistically significantly higher measures of inflammation or oxidative stress. There were no differences in micronutrient concentrations between Lc and Ob infants, but folate, vitamin B6 and zinc levels correlated strongly between mother and infant. There was no statistically significant difference in any parameter between Ob and Lc cord blood. Ob pregnant women have increased inflammation and oxidative stress, and lower levels of nutritional antioxidant defenses compared with Lc pregnant women. We speculate that lower antioxidant defenses combined with increased oxidative stress and inflammation may contribute to the adverse outcomes associated with pregnancy in Ob women.

  11. Plasma Prolidase Activity and Oxidative Stress in Patients with Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Akhilesh Kumar Verma

    2015-01-01

    Full Text Available Prolidase deficiency has been related to mental retardation and oxidative stress. The study aimed to observe plasma prolidase activity (PPA, total oxidant status (TOS, total antioxidant status (TAS, and oxidative stress index (OSI in patients with Parkinson’s disease (PD. 240 subjects with PD and 150 healthy volunteers were considered as cases and controls, respectively. PPA, TOS, TAS, and OSI were measured spectrophotometrically. PPA and TAS in cases were more significantly decreased than controls (P<0.01, while TOS and OSI were significantly increased (P<0.001. In cases, nonsignificant, positive correlation was observed between PPA and TOS and OSI while significant, negative correlation was observed between PPA and TAS (P=0.047. PPA in cases was nonsignificantly decreased with increased duration of PD (P=0.747 while TAS was significantly decreased (P<0.001 and TOS and OSI were significantly increased (P<0.001. It was observed that higher age groups had decreased PPA, and TAS and increased TOS and OSI compared to lower age groups in cases. In summary, patients with PD have decreased PPA and increased oxidative stress compared to healthy volunteers. PPA was associated with oxidative stress markers in patients with PD. Decreased PPA and TAS and increased TOS and OSI were associated with progression of disease and higher age.

  12. Plasma Prolidase Activity and Oxidative Stress in Patients with Parkinson's Disease

    Science.gov (United States)

    Verma, Akhilesh Kumar; Raj, Janak; Sharma, Vivek; Singh, Tej Bali; Srivastava, Shalabh; Srivastava, Ragini

    2015-01-01

    Prolidase deficiency has been related to mental retardation and oxidative stress. The study aimed to observe plasma prolidase activity (PPA), total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI) in patients with Parkinson's disease (PD). 240 subjects with PD and 150 healthy volunteers were considered as cases and controls, respectively. PPA, TOS, TAS, and OSI were measured spectrophotometrically. PPA and TAS in cases were more significantly decreased than controls (P < 0.01), while TOS and OSI were significantly increased (P < 0.001). In cases, nonsignificant, positive correlation was observed between PPA and TOS and OSI while significant, negative correlation was observed between PPA and TAS (P = 0.047). PPA in cases was nonsignificantly decreased with increased duration of PD (P = 0.747) while TAS was significantly decreased (P < 0.001) and TOS and OSI were significantly increased (P < 0.001). It was observed that higher age groups had decreased PPA, and TAS and increased TOS and OSI compared to lower age groups in cases. In summary, patients with PD have decreased PPA and increased oxidative stress compared to healthy volunteers. PPA was associated with oxidative stress markers in patients with PD. Decreased PPA and TAS and increased TOS and OSI were associated with progression of disease and higher age. PMID:26347150

  13. Oxidant-antioxidant status and pulmonary function in welding workers.

    Science.gov (United States)

    Fidan, Fatma; Unlü, Mehmet; Köken, Tülay; Tetik, Levent; Akgün, Sema; Demirel, Reha; Serteser, Mustafa

    2005-07-01

    Welding is a process during which fumes, gases, electromagnetic radiation and noise are emitted as by-products. Metal oxide particles are particularly hazardous components of welding fumes. Welding has been found to be associated with respiratory symptoms and our objective in the present study was to study the effects of welding on pulmonary function and serum oxidant-antioxidant status. Fifty-one welding workers and 31 control subjects were recruited. Face to face interviews were conducted using the respiratory illness questionnaire adapted from the American Thoracic Society with the addition of demographic characteristics, work history and working conditions. Additionally physical examinations and spirometric measurements were performed at workplaces. Thiobarbituric acid reactive substances (TBARS), protein carbonyls, protein sulfhydryls (SH) and erythrocyte reduced glutathione (GSH) levels were measured to evaluate oxidant-antioxidant status in 34 welding workers and in 20 control subjects. No statistically significant differences were observed in age, height, weight, body mass index (BMI), smoking status and annual working durations between welding workers and controls. Coughing, sputting and wheezing were significantly higher in welding workers (pwelding work showed a significant risk for chronic bronchitis (OR: 4.78, 95%CI: 1.30-17.54). Forced expiratory volume in one second (FEV(1))/forced vital capacity (FVC) and four parameters of forced expiratory flow (FEF: FEF(25), FEF(50), FEF(75), FEF(25-75)) levels measured in the welding workers were significantly lower than those in the control group (pwelding workers than those in controls (pwelding workers chronically exposed to welding fumes and gases. Preventive measures should be taken to improve the health status of these workers.

  14. Oxidative Stress Status in Childhood Obesity: A Potential Risk Predictor

    Science.gov (United States)

    Kilic, Elif; Özer, Ömer Faruk; Erek, Aybala Toprak; Erman, Hayriye; Torun, Emel; Ayhan, Sıddıka Kesgin; Caglar, Hifa Gülru; Selek, Sahbettin; Kocyigit, Abdurrahim

    2016-01-01

    Background Childhood obesity characterized by excessive fat in the body is one of the most serious health problems worldwide due to the social, medical, and physiological complications. Obesity and associated diseases are triggering factors for oxidative stress and inflammation. The aim of this study was to explore the possible association between childhood obesity and inflammatory and oxidative status. Material/Methods Thirty-seven obese children and 37 healthy controls selected from among children admitted to BLIND University Paediatrics Department were included in the study. Anthropometric measurements were performed using standard methods. Glucose, lipid parameters, CRP, insulin, total oxidant status (TOS), total anti-oxidant status (TAS) levels, and total thiol levels (TTL) were measured in serum. HOMA index (HOMA-IR) were calculated. The differences between the groups were evaluated statistically using the Mann-Whitney U test. Results Body mass index was significantly higher in the obese group (median: 28.31(pLDL cholesterol, and triglyceride levels were significantly higher in the obese group (p<0.001). TAS (med: 2.5 μmol Trolox eq/L (1.7–3.3)) and TOS (med: 49.1 μmol H2O2 eq/L (34.5–78.8)) levels and TTL (med: 0.22 mmol/L (0.16–0.26)) were significantly higher in the obese group (p=0.001). CRP levels showed positive correlation with TOS and negative correlation with TTL levels (p=0.005, r=0.473; p=0.01, r=−0.417; respectively). TTL levels exhibited negative correlation with TOS levels (p=0.03, r=−0.347). Conclusions In conclusion, obese children were exposed to more oxidative burden than children with normal weight. Increased systemic oxidative stress induced by childhood obesity can cause development of obesity-related complications and diseases. Widely focussed studies are required on the use of oxidative parameters as early prognostic parameters in detection of obesity-related complications. PMID:27733746

  15. Plasma protein oxidation and total antioxidant power in premenstrual syndrome

    Institute of Scientific and Technical Information of China (English)

    Eans Tara Tuladhar; Anjali Rao

    2010-01-01

    Objective:To explore whether oxidative stress has any role inpremenstrual syndrome (PMS). Methods: Female volunteers suffering from PMS , in the age group of 20-24 years were compared to their asymptomatic normomennorhoeic counterparts in follicular phase and late luteal phase for ferric reducing antioxidant power of plasma(FRAP), plasma protein thiols(PPT) and protein carbonyls(PPC) levels.Results:There was no significant change in FRAP and PPC levels in controls andPMS groups but PPT decreased significantly in luteal phase ofPMS (P< 0.05) when compared to follicular phase.Conclusions:Estrogen and progesterone, might be responsible for a healthy antioxidant profile inPMS. However, a marked decrease inPPT in luteal phase of PMS group may be due to pro-oxidant nature of estrogen-active in this phase of PMS leading to consumption of the sacrificial antioxidant-protein thiol.

  16. Differential plasma protein binding to metal oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Zhou J; Mortimer, Gysell; Minchin, Rodney F [School of Biomedical Sciences, University of Queensland, Brisbane, QLD 4072 (Australia); Schiller, Tara; Musumeci, Anthony; Martin, Darren, E-mail: r.minchin@uq.edu.a [Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Brisbane, QLD 4072 (Australia)

    2009-11-11

    Nanoparticles rapidly interact with the proteins present in biological fluids, such as blood. The proteins that are adsorbed onto the surface potentially dictate the biokinetics of the nanomaterials and their fate in vivo. Using nanoparticles with different sizes and surface characteristics, studies have reported the effects of physicochemical properties on the composition of adsorbed plasma proteins. However, to date, few studies have been conducted focusing on the nanoparticles that are commonly exposed to the general public, such as the metal oxides. Using previously established ultracentrifugation approaches, two-dimensional gel electrophoresis and mass spectrometry, the current study investigated the binding of human plasma proteins to commercially available titanium dioxide, silicon dioxide and zinc oxide nanoparticles. We found that, despite these particles having similar surface charges in buffer, they bound different plasma proteins. For TiO{sub 2}, the shape of the nanoparticles was also an important determinant of protein binding. Agglomeration in water was observed for all of the nanoparticles and both TiO{sub 2} and ZnO further agglomerated in biological media. This led to an increase in the amount and number of different proteins bound to these nanoparticles. Proteins with important biological functions were identified, including immunoglobulins, lipoproteins, acute-phase proteins and proteins involved in complement pathways and coagulation. These results provide important insights into which human plasma proteins bind to particular metal oxide nanoparticles. Because protein absorption to nanoparticles may determine their interaction with cells and tissues in vivo, understanding how and why plasma proteins are adsorbed to these particles may be important for understanding their biological responses.

  17. Air trichloroethylene oxidation in a corona plasma-catalytic reactor

    Science.gov (United States)

    Masoomi-Godarzi, S.; Ranji-Burachaloo, H.; Khodadadi, A. A.; Vesali-Naseh, M.; Mortazavi, Y.

    2014-08-01

    The oxidative decomposition of trichloroethylene (TCE; 300 ppm) by non-thermal corona plasma was investigated in dry air at atmospheric pressure and room temperature, both in the absence and presence of catalysts including MnOx, CoOx. The catalysts were synthesized by a co-precipitation method. The morphology and structure of the catalysts were characterized by BET surface area measurement and Fourier Transform Infrared (FTIR) methods. Decomposition of TCE and distribution of products were evaluated by a gas chromatograph (GC) and an FTIR. In the absence of the catalyst, TCE removal is increased with increases in the applied voltage and current intensity. Higher TCE removal and CO2 selectivity is observed in presence of the corona and catalysts, as compared to those with the plasma alone. The results show that MnOx and CoOx catalysts can dissociate the in-plasma produced ozone to oxygen radicals, which enhances the TCE decomposition.

  18. Relationships between isotopic values and oxidative status: insights from populations of gentoo penguins.

    Science.gov (United States)

    Beaulieu, Michaël; González-Acuña, Daniel; Thierry, Anne-Mathilde; Polito, Michael J

    2015-04-01

    Feeding strategies can affect the balance between the production of reactive oxygen species and antioxidant defences (i.e. oxidative status). This is ecologically relevant, as variation in oxidative status can in turn strongly affect fitness. However, how animals regulate their oxidative status through their feeding behaviour under natural conditions remains poorly understood. Thus, relating the isotopic values of free-ranging animals to their oxidative status may prove useful. Here, we considered three colonies of gentoo penguins (Pygoscelis papua) in which we measured (1) δ(13)C and δ(15)N values, and (2) antioxidant defences and oxidative damage. We found that colonies with the highest δ(13)C and δ(15)N values also had the highest levels of antioxidant defences and oxidative damage, resulting in positive relationships between isotopic values and markers of oxidative status. As a result, colony segregation in terms of isotopic values was reflected by segregation in terms of oxidative markers (although more markedly for oxidative damage than for antioxidant defences). Interestingly, variation in the estimated contribution of krill in the diet of penguins followed an opposite pattern to that observed for markers of oxidative status, providing evidence that inter-population differences in terms of foraging strategies can result in inter-population differences in terms of oxidative status. More studies examining simultaneously oxidative status, isotopic signature, foraging behaviour and food allocation between parents and young are, however, needed to understand better the interplay between the foraging strategies adopted by animals in their natural habitat and their oxidative status.

  19. Oxidative stress and nutritional status in chronic obstructive pulmonary disease.

    Science.gov (United States)

    Dhakal, Niraj; Lamsal, Madhab; Baral, Nirmal; Shrestha, Shrijana; Dhakal, Subodh Sagar; Bhatta, Narendra; Dubey, Raju Kumar

    2015-02-01

    Oxidative stress and malnutrition are shown to have pathogenic effect in Chronic Obstructive Pulmonary Disease (COPD). This study was done to assess the burden of oxidative stress in COPD and to determine its relation to their nutritional status. In this cross-sectional study, 100 COPD cases from emergency and medical ward and meeting inclusion criteria, along with age, sex and occupation (mainly farmers, housewives and drivers) matched 100 controls without COPD and meeting inclusion criteria were enrolled. Oxidative stress was assessed by measuring lipid peroxidation product, Malondialdehyde (MDA) and antioxidants, like Vitamin C, E and Red Blood Cell Catalase (RBCC). Mini Nutritional Assessment (MNA) tool and Body Mass Index (BMI) were used to assess nutritional status. Chi-square test was applied for categorical variable. Student t-test was applied for comparison of means. Analysis of Variance (ANOVA) was applied for comparison between groups followed by Bonferroni post hoc analysis. Pearson correlation method was used for quantitative variables. Statistical significance was defined as pnutritional management.

  20. Study on electrolytic plasma discharging behavior and its influence on the plasma electrolytic oxidation coatings

    Science.gov (United States)

    Hussein, Riyad Omran

    In this study, aluminum oxide was deposited on a pure aluminum substrate to produce hard ceramic coatings using a Plasma Electrolytic Oxidation (PEO) process. The process utilized DC, unipolar pulsed DC in the frequency range (0.2 KHz -- 20 KHz) and bipolar pulsed DC current modes. The effects of process parameters (i.e., electrolyte concentration, current density and treatment time) on the plasma discharge behavior during the PEO treatment were investigated using optical emission spectroscopy (OES) in the visible and near ultraviolet (NUV) band (285 nm -- 900 nm). The emission spectra were recorded and plasma temperature profile versus processing time was constructed using the line intensity ratios method. Scanning Electron Microscopy (SEM) with energy dispersive x-ray analysis (EDS) was used to study the coating microstructure. It was found that the plasma discharge behavior significantly influenced the microstructure and the morphology of the oxide coatings. The main effect came from the strongest discharges which were initiated at the interface between the substrate and the coating. Through manipulation of process parameters to control or reduce the strongest discharge, the density and quality of the coating layers could be modified. This work demonstrated that by adjusting the ratio of the positive to negative pulse currents as well as their timing in order to eliminate the strongest discharges, the quality of the coatings was considerably improved.

  1. DIABETES, DYSLIPIDEMIA, ANTIOXIDANT AND STATUS OF OXIDATIVE STRESS

    Directory of Open Access Journals (Sweden)

    Bisht Shradha

    2010-09-01

    Full Text Available The cluster of lipid abnormalities associated with type 2 diabetes is defined by increases in triglyceride (TG and small, dense low-density lipoprotein (LDL concentrations and decreases in high-density lipoprotein (HDL cholesterol. Plasma LDL cholesterol levels are generally normal because the increase in the number of small, dense LDL particles is accompanied by a reduction in large LDL particles. Each of the features of diabetic dyslipidemia has been associated with increased risk of cardiovascular disease, the leading cause of death in type 2 diabetics. Increasing evidence in both experimental and clinical studies suggests that oxidative stress plays a major role in the pathogenesis of both types of diabetes mellitus. Free radicals are formed disproportionately in diabetes by glucose oxidation, nonenzymatic glycation of proteins, and the subsequent oxidative degradation of glycated proteins. Abnormally high levels of free radicals and the simultaneous decline of antioxidant defense mechanisms can lead to damage of cellular organelles and enzymes, increased lipid peroxidation, and development of insulin resistance. These consequences of oxidative stress can promote the development of complications of diabetes mellitus. Changes in oxidative stress biomarkers, including superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase, glutathione levels, vitamins, lipid peroxidation, nitrite concentration, nonenzymatic glycosylated proteins, and hyperglycemia in diabetes, and their consequences, are discussed in this review. In vivo studies of the effects of various conventional and alternative drugs on these biomarkers are surveyed. There is a need to continue to explore the relationship between free radicals, diabetes, and its complications, and to elucidate the mechanisms by which increased oxidative stress accelerates the development of diabetic complications, in an effort to expand treatment options.

  2. Status and challenges in electrical diagnostics of processing plasmas

    DEFF Research Database (Denmark)

    Stamate, Eugen

    2014-01-01

    Dry processing based on reactive plasmas was the main driven force for micro- and recently nano-electronic industry. Once with the increasing in plasma complexity new diagnostics methods have been developed to ensure a proper process control during etching, thin film deposition, ion implantation...... or other steps in device fabrication. This work reviews some of the unconventional methods developed in the last two decays to measure the parameters of reactive plasmas including, the test function method, thermal probes, and plasma-sheath-lens probes. The negative ion detection and surface contamination...... in plasmas with a high degree of contamination are also addressed. (C) 2014 Elsevier B.V. All rights reserved....

  3. Evaluation of Oxidative Status in Patients Treated with Electroconvulsive Therapy

    Science.gov (United States)

    Şenyurt, Mahmut; Aybek, Hulya; Herken, Hasan; Kaptanoglu, Bunyamin; Korkmaz, Ali

    2017-01-01

    Objective Electroconvulsive therapy (ECT) is used in the treatment of many psychiatric diseases and this therapy may be effective on antioxidant defence system. In this study, we aimed to evaluate the effects of ECT on oxidative stress. Methods Fourteen major depression, 11 schizophrenia and 8 bipolar affective disorder patients diagnosed and received ECT treatment, and 37 healthy volunteers enrolled in the study. ECT was applied to all patients. Before ECT, after the first and last ECTs, serum samples were obtained. Serum total antioxidant status (TAS), total oxidant status (TOS), and calculated oxidative stress index (OSI) were measured in patients before and after ECTs. Results TOS values before ECT were higher in major depression (p=0.005) and schizophrenia (p=0.001) groups compared to the control group. TAS values were lower in major depression (p=0.0001), schizophrenia (p=0.004), bipolar affective disorder (p=0.004) groups compared to the controls. Also OSI values were higher in major depression (p=0.0001), schizophrenia (p=0.001), bipolar affective disorder (p=0.009) groups compared to healthy group. After the last ECT, TOS values were significantly lower compared to TOS values before ECT in major depression (p=0.004) and schizophrenia patients (p=0.004). TAS values after the first ECT were higher compared to values before ECT in major depression patients (p=0.004). After last ECT, OSI values were significantly lower compared to before ECT in schizophrenia patients (p=0.006). Conclusion As a result, it can be said that ECT did not increase oxidative stress. However, further studies with more patients are needed. PMID:28138109

  4. MERCURY OXIDIZATION IN NON-THERMAL PLASMA BARRIER DISCHARGE SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    V.K. Mathur

    2003-02-01

    In the past decade, the emission of toxic elements from human activities has become a matter of great public concern. Hg, As, Se and Cd typically volatilize during a combustion process and are not easily caught with conventional air pollution control techniques. In addition, there is no pollution prevention technique available now or likely be available in the foreseeable future that can prevent the emission of these trace elements. These trace elements pose additional scientific challenge as they are present at only ppb levels in large gas streams. Mercury, in particular, has attracted significant attention due to its high volatility, toxicity and potential threat to human health. In the present research work, a non-thermal plasma dielectric barrier discharge technique has been used to oxidize Hg{sup 0}(g) to HgO. The basic premise of this approach is that Hg{sup 0} in vapor form cannot be easily removed in an absorption tower whereas HgO as a particulate is amiable to water scrubbing. The work presented in this report consists of three steps: (1) setting-up of an experimental apparatus to generate mercury vapors at a constant rate and modifying the existing non-thermal plasma reactor system, (2) solving the analytical challenge for measuring mercury vapor concentration at ppb level, and (3) conducting experiments on mercury oxidation under plasma conditions to establish proof of concept.

  5. Present status on atomic and molecular data relevant to fusion plasma diagnostics and modeling

    Energy Technology Data Exchange (ETDEWEB)

    Tawara, H. [ed.

    1997-01-01

    This issue is the collection of the paper presented status on atomic and molecular data relevant to fusion plasma diagnostics and modeling. The 10 of the presented papers are indexed individually. (J.P.N.)

  6. The changes and clinical significance of plasma redox status in acute coronary syndromes

    Institute of Scientific and Technical Information of China (English)

    段明勤

    2013-01-01

    Objective To explore the changes and clinical significance of plasma redox status in patients with acute myocardial infarction,angina pectoris and people with normal coronary artery.Methods According to the clinical

  7. Total oxidant status and oxidative stress are increased in infants with necrotizing enterocolitis.

    Science.gov (United States)

    Aydemir, Cumhur; Dilli, Dilek; Uras, Nurdan; Ulu, Hulya Ozkan; Oguz, Serife Suna; Erdeve, Omer; Dilmen, Ugur

    2011-11-01

    Oxidative stress has been implicated in the pathogenesis of necrotizing enterocolitis (NEC). In this study, we compared the global oxidant/antioxidant status by measuring total antioxidant capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) in preterm infants with NEC and with control preterms. Forty-one preterm neonates with NEC (stage 1 [group 1; n = 23] and stages 2 and 3 [group 2; n = 18]) and age-matched 36 healthy preterm controls (group 3) were included in this study. Blood samples were obtained both at the time of NEC diagnosis and 72 hours after for the evaluation of TAC and TOS. Serum levels of TAC, TOS, and OSI in patients with NEC were compared with controls. Demographic characteristics were comparable in all 3 groups. Preterm neonates in group 2 (with stages 2 and 3 NEC) had the highest TOS levels and OSI (P oxidant stress mechanisms were activated in preterm neonates with definite NEC (stages 2 and 3 NEC). Premature neonates with increased levels of TOS and OSI were associated with severity of NEC. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. High-Frequency-Induced Cathodic Breakdown during Plasma Electrolytic Oxidation

    Science.gov (United States)

    Nominé, A.; Nominé, A. V.; Braithwaite, N. St. J.; Belmonte, T.; Henrion, G.

    2017-09-01

    The present communication shows the possibility of observing microdischarges under cathodic polarization during plasma electrolytic oxidation at high frequency. Cathodic microdischarges can ignite beyond a threshold frequency found close to 2 kHz. The presence (respectively, absence) of an electrical double layer is put forward to explain how the applied voltage can be screened, which therefore prevents (respectively, promotes) the ignition of a discharge. Interestingly, in the conditions of the present study, the electrical double layer requires between 175 and 260 μ s to form. This situates the expected threshold frequency between 1.92 and 2.86 kHz, which is in good agreement with the value obtained experimentally.

  9. Stimulation of colonic mucosal growth associated with oxidized redox status in rats.

    Science.gov (United States)

    Tian, Junqiang; Washizawa, Naohiro; Gu, Li H; Levin, Marc S; Wang, Lihua; Rubin, Deborah C; Mwangi, Simon; Srinivasan, Shanthi; Gao, Yuhao; Jones, Dean P; Ziegler, Thomas R

    2007-03-01

    Limited data in animal models suggest that colonic mucosa undergoes adaptive growth following massive small bowel resection (SBR). In vitro data suggest that intestinal cell growth is regulated by reactive oxygen species and redox couples [e.g., glutathione (GSH)/glutathione disulfide (GSSG) and cysteine (Cys)/cystine (CySS) redox]. We investigated the effects of SBR and alterations in redox on colonic growth indexes in rats after either small bowel transection (TX) or 80% midjejunoileal resection (RX). Rats were pair fed +/- blockade of endogenous GSH synthesis with buthionine sulfoximine (BSO). Indexes of colonic growth, proliferation, and apoptosis and GSH/GSSG and Cys/CySS redox potentials (E(h)) were determined. RX significantly increased colonic crypt depth, number of cells per crypt, and epithelial cell proliferation [crypt cell bromodeoxyuridine (BrdU) incorporation]. Administration of BSO markedly decreased colonic mucosal GSH, GSSG, and Cys concentrations in both TX and RX groups, with a resultant oxidation of GSH/GSSG and Cys/CySS E(h). BSO did not alter colonic crypt cell apoptosis but significantly increased all colonic mucosal growth indexes (crypt depth, cells/crypt, and BrdU incorporation) in both TX and RX groups in a time- and dose-dependent manner. BSO significantly decreased plasma GSH and GSSG, oxidized GSH/GSSG E(h), and increased plasma Cys and CySS concentrations. Collectively, these data provide in vivo evidence indicating that oxidized colonic mucosal redox status stimulates colonic mucosal growth in rats. The data also suggest that GSH is required to maintain normal colonic and plasma Cys/CySS homeostasis in these animal models.

  10. Corrosion evaluation of zirconium doped oxide coatings on aluminum formed by plasma electrolytic oxidation.

    Science.gov (United States)

    Bajat, Jelena; Mišković-Stanković, Vesna; Vasilić, Rastko; Stojadinović, Stevan

    2014-01-01

    The plasma electrolytic oxidation (PEO) of aluminum in sodium tungstate (Na(2)WO(4) · (2)H(2)O) and Na(2)WO(4) · (2)H(2)O doped with Zr was analyzed in order to obtain oxide coatings with improved corrosion resistance. The influence of current density in PEO process and anodization time was investigated, as well as the influence of Zr, with the aim to find out how they affect the chemical content, morphology, surface roughness, and corrosion stability of oxide coatings. It was shown that the presence of Zr increases the corrosion stability of oxide coatings for all investigated PEO times. Evolution of EIS spectra during the exposure to 3% NaCl, as a strong corrosive agent, indicated the highest corrosion stability for PEO coating formed on aluminum at 70 mA/cm(2) for 2 min in a zirconium containing electrolyte.

  11. Oxidative stress and antioxidant status in beta-thalassemia heterozygotes

    Directory of Open Access Journals (Sweden)

    Luciana de Souza Ondei

    2013-01-01

    Full Text Available Background: Several studies have evaluated the oxidant and antioxidant status of thalassemia patients but most focused mainly on the severe and intermediate states of the disease. Moreover, the oxidative status has not been evaluated for the different beta-thalassemia mutations. Objective: To evaluate lipid peroxidation and Trolox equivalent antioxidant capacity in relation to serum iron and ferritin in beta thalassemia resulting from two different mutations (CD39 and IVS-I-110 compared to individuals without beta-thalassemia. Methods: One hundred and thirty subjects were studied, including 49 who were heterozygous for beta-thalassemia and 81 controls. Blood samples were subjected to screening tests for hemoglobin. Allele-specific polymerase chain reaction was used to confirm mutations for beta-thalassemia, an analysis of thiobarbituric acid reactive species was used to determine lipid peroxidation, and Trolox equivalent antioxidant capacity evaluations were performed. The heterozygous beta-thalassemia group was also evaluated for serum iron and ferritin status. Results: Thiobarbituric acid reactive species (486.24 ± 119.64 ng/mL and Trolox equivalent antioxidant capacity values (2.23 ± 0.11 mM/L were higher in beta-thalassemia heterozygotes compared to controls (260.86 ± 92.40 ng/mL and 2.12 ± 0.10 mM/L, respectively; p-value < 0.01. Increased thiobarbituric acid reactive species values were observed in subjects with the CD39 mutation compared with those with the IVS-I-110 mutation (529.94 ± 115.60 ng/mL and 453.39 ± 121.10 ng/mL, respectively; p-value = 0.04. However, average Trolox equivalent antioxidant capacity values were similar for both mutations (2.20 ± 0.08 mM/L and 2.23 ± 0.12 mM/L, respectively; p-value = 0.39. There was no influence of serum iron and ferritin levels on thiobarbituric acid reactive species and Trolox equivalent antioxidant capacity values. Conclusion: This study shows an increase of oxidative stress and

  12. Perioperative plasma concentrations of stable nitric oxide products are predictive of cognitive dysfunction after laparoscopic cholecystectomy.

    LENUS (Irish Health Repository)

    Iohom, G

    2012-02-03

    In this study our objectives were to determine the incidence of postoperative cognitive dysfunction (POCD) after laparoscopic cholecystectomy under sevoflurane anesthesia in patients aged >40 and <85 yr and to examine the associations between plasma concentrations of i) S-100beta protein and ii) stable nitric oxide (NO) products and POCD in this clinical setting. Neuropsychological tests were performed on 42 ASA physical status I-II patients the day before, and 4 days and 6 wk after surgery. Patient spouses (n = 13) were studied as controls. Cognitive dysfunction was defined as deficit in one or more cognitive domain(s). Serial measurements of serum concentrations of S-100beta protein and plasma concentrations of stable NO products (nitrate\\/nitrite, NOx) were performed perioperatively. Four days after surgery, new cognitive deficit was present in 16 (40%) patients and in 1 (7%) control subject (P = 0.01). Six weeks postoperatively, new cognitive deficit was present in 21 (53%) patients and 3 (23%) control subjects (P = 0.03). Compared with the "no deficit" group, patients who demonstrated a new cognitive deficit 4 days postoperatively had larger plasma NOx at each perioperative time point (P < 0.05 for each time point). Serum S-100beta protein concentrations were similar in the 2 groups. In conclusion, preoperative (and postoperative) plasma concentrations of stable NO products (but not S-100beta) are associated with early POCD. The former represents a potential biochemical predictor of POCD.

  13. Systemic Inflammatory Response Syndrome in End-Stage Heart Failure Patients Following Continuous-Flow Left Ventricular Assist Device Implantation: Differences in Plasma Redox Status and Leukocyte Activation.

    Science.gov (United States)

    Mondal, Nandan K; Sorensen, Erik N; Pham, Si M; Koenig, Steven C; Griffith, Bartley P; Slaughter, Mark S; Wu, Zhongjun J

    2016-05-01

    The role of oxidative stress and leukocyte activation has not been elucidated in developing systemic inflammatory response syndrome (SIRS) in heart failure (HF) patients after continuous-flow left ventricular assist device (CF-LVAD) implantation. The objective of this study was to investigate the change of plasma redox status and leukocyte activation in CF-LVAD implanted HF patients with or without SIRS. We recruited 31 CF-LVAD implanted HF patients (16 SIRS and 15 non-SIRS) and 11 healthy volunteers as the control. Pre- and postimplant blood samples were collected from the HF patients. Plasma levels of oxidized low-density lipoprotein (oxLDL), malondialdehyde (MDA), total antioxidant capacity (TAC), superoxide dismutase (SOD) in erythrocyte, myeloperoxidase (MPO), and polymorphonuclear elastase (PMN-elastase) were measured. The HF patients had a preexisting condition of oxidative stress than healthy controls as evident from the higher oxLDL and MDA levels as well as depleted SOD and TAC. Leukocyte activation in terms of higher plasma MPO and PMN-elastase was also prominent in HF patients than controls. Persistent oxidative stress and reduced antioxidant status were found to be more belligerent in HF patients with SIRS after the implantation of CF-LVAD when compared with non-SIRS patients. Similar to oxidative stress, the activation of blood leukocyte was significantly highlighted in SIRS patients after implantation compared with non-SIRS. We identified that the plasma redox status and leukocyte activation became more prominent in CF-LVAD implanted HF patients who developed SIRS. Our findings suggest that plasma biomarkers of oxidative stress and leukocyte activation may be associated with the development of SIRS after CF-LVAD implant surgery.

  14. Fetal undernutrition is associated with perinatal sex-dependent alterations in oxidative status.

    Science.gov (United States)

    Rodríguez-Rodríguez, Pilar; de Pablo, Angel Luis López; Condezo-Hoyos, Luis; Martín-Cabrejas, María Angeles; Aguilera, Yolanda; Ruiz-Hurtado, Gema; Gutierrez-Arzapalo, Perla Y; Ramiro-Cortijo, David; Fernández-Alfonso, María Soledad; González, María Del Carmen; Arribas, Silvia M

    2015-12-01

    Intrauterine growth retardation predisposes to hypertension development, known as fetal programming. Females are less susceptible, which has been mainly attributed to estrogen influence. We hypothesize that perinatal differences in oxidative status might also contribute. We studied 21-day-old (prepuberal) and 6-month-old male and female offspring from rats fed ad libitum during gestation (Control) or with 50% of Control daily intake from day 10 to delivery (maternal undernutrition, MUN). We assessed in vivo blood pressure and the following plasma biomarkers of oxidative status: protein carbonyls, thiols, reduced glutathione (GSH), total antioxidant capacity, superoxide anion scavenging activity (SOSA) and catalase activities; we calculated a global score (oxy-score) from them. Estradiol and melatonin concentration was measured in young rats. Prepuberal MUN males were normotensive but already exhibited increased carbonyls and lower thiols, GSH, SOSA and melatonin; oxy-score was significantly lower compared to Control males. Prepuberal MUN females only exhibited reduced SOSA compared to Control females. Adult rats from all experimental groups showed a significant increase in carbonyls and a decrease in antioxidants compared to prepuberal rats; oxy-score was negative in adult rats suggesting the development of a prooxidative status as rat age. Adult MUN males were hypertensive and exhibited the highest increase in carbonyls despite similar or even higher antioxidant levels compared to Controls. Adult MUN females remained normotensive and did not exhibit differences in any of the biomarkers compared to Controls. The better global antioxidant status developed by MUN females during perinatal life could contribute to their protection against hypertension programming.

  15. Serum total oxidant and antioxidant status in earthquake survivors with post-traumatic stress disorder.

    Science.gov (United States)

    Ozdemir, Pinar Guzel; Kaplan, İbrahim; Uysal, Cem; Bulut, Mahmut; Atli, Abdullah; Bez, Yasin; Kaya, Mehmet Cemal; Ozdemir, Osman

    2015-06-01

    Oxidative stress has been shown to play an important role in the pathogenesis of post-traumatic stress disorder (PTSD). Although there are some studies on oxidative stress and PTSD, there is no report available on the serum total oxidant and antioxidant status in earthquake survivors with PTSD. Therefore, this study aimed to investigate the serum total oxidant and antioxidant status in earthquake survivors with chronic PTSD. The study group included 45 earthquake survivors with PTSD and 40 earthquake survivors without PTSD. The oxidative status was determined using the total antioxidant status and total oxidant status (TOS) measurements and by calculating the oxidative stress index (OSI). There were no statistically significant differences in the total antioxidant status, TOS, or OSI when comparing individuals with and without PTSD (all, p>0.05). There were no correlations between Clinician-Administered PTSD Scale scores and oxidant and antioxidant stress markers (all, p>0.05). Our results suggest that the total oxidant and antioxidant status may not affect earthquake survivors with PTSD. This is the first study to evaluate the oxidative status in earthquake survivors with PTSD. Further studies are necessary to confirm these findings.

  16. The effect of grape-skin extract on oxidative status

    DEFF Research Database (Denmark)

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

    2000-01-01

    Epidemiological studies indicate that moderate alcohol consumption, particularly wine, reduce the risk of CHD. The present study was designed to investigate the effect of grape-skin extract on markers of oxidative status. The study was designed as a randomised crossover. A diet with a low content...... of flavonoids was served with strict control of intake in two consecutive 1-week intervention periods to fifteen subjects (nine women, six men) divided randomly into two groups. During one of the weeks the subjects from either group consumed 200 ml grape-skin extract in water (1 mg extract/ml) at each of three...... daily meals (31.3 mg total phenolics, including 9.0 mg catechin). An increased activity of glutathione reductase and a borderline increase of glutathione peroxidase activity in erythrocytes were observed after grape-skin intervention, while the intervention had no significant effect on superoxide...

  17. The effect of grape-skin extract on oxidative status

    DEFF Research Database (Denmark)

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

    2000-01-01

    Epidemiological studies indicate that moderate alcohol consumption, particularly wine, reduce the risk of CHD. The present study was designed to investigate the effect of grape-skin extract on markers of oxidative status. The study was designed as a randomised crossover. A diet with a low content...... of flavonoids was served with strict control of intake in two consecutive 1-week intervention periods to fifteen subjects (nine women, six men) divided randomly into two groups. During one of the weeks the subjects from either group consumed 200 ml grape-skin extract in water (1 mg extract/ml) at each of three...... daily meals (31.3 mg total phenolics, including 9.0 mg catechin). An increased activity of glutathione reductase and a borderline increase of glutathione peroxidase activity in erythrocytes were observed after grape-skin intervention, while the intervention had no significant effect on superoxide...

  18. Plasma Measurements: An Overview of Requirements and Status

    Energy Technology Data Exchange (ETDEWEB)

    Kenneth M. Young

    2008-01-04

    This paper introduces this special issue on plasma diagnostics for magnetic fusion devices. Its primary purpose is to relate the measurements of plasma parameters to the physics challenges to be faced on operating and planned devices, and also to identify the diagnostic techniques that are used to make these measurements. The specific physics involved in the application of the techniques will be addressed in subsequent chapters. This chapter is biased toward measurements for tokamaks because of their proximity to the burning plasma frontier, and to set the scene for the development work associated with ITER. Hence, there is some emphasis on measurements for alpha-physics studies and the needs for plasma measurements as input to actuators to control the plasma, both for optimizing the device performance and for protection of the surrounding material. The very different approach to the engineering of diagnostics for a burning plasma is considered, emphasizing the needs for new calibration ideas, reliability and hardness against, and compatibility with, radiation. New ideas take a long time to be converted into "work-horse" sophisticated diagnostics so that investment in new developments is essential for ITER, particularly for the measurement of alpha-particles.

  19. Nitrogen oxides and methane treatment by non-thermal plasma

    Science.gov (United States)

    Alva, E.; Pacheco, M.; Colín, A.; Sánchez, V.; Pacheco, J.; Valdivia, R.; Soria, G.

    2015-03-01

    Non thermal plasma was used to treat nitrogen oxides (NOx) and methane (CH4), since they are important constituents of hydrocarbon combustion emissions processes and, both gases, play a key role in the formation of tropospheric ozone. These gases are involved in environmental problems like acid rain and some diseases such as bronchitis and pneumonia. In the case of methane is widely known its importance in the global climate change, and currently accounts for 30% of global warming. There is a growing concern for methane leaks, associated with a rapid expansion of unconventional oil and gas extraction techniques as well as a large-scale methane release from Arctic because of ice melting and the subsequent methane production of decaying organic matter. Therefore, methane mitigation is a key to avoid dangerous levels of global warming. The research, here reported, deals about the generation of non-thermal plasma with a double dielectric barrier (2DBD) at atmospheric pressure with alternating current (AC) for NOx and CH4 treatment. The degradation efficiencies and their respective power consumption for different reactor configurations (cylindrical and planar) are also reported. Qualitative and quantitative analysis of gases degradation are reported before and after treatment with cold plasma. Experimental and theoretical results are compared obtaining good removal efficiencies, superior to 90% and to 20% respectively for NOx and CH4.

  20. Nitric oxide, cholesterol oxides and endothelium-dependent vasodilation in plasma of patients with essential hypertension

    Directory of Open Access Journals (Sweden)

    P. Moriel

    2002-11-01

    Full Text Available The objective of the present study was to identify disturbances of nitric oxide radical (·NO metabolism and the formation of cholesterol oxidation products in human essential hypertension. The concentrations of·NO derivatives (nitrite, nitrate, S-nitrosothiols and nitrotyrosine, water and lipid-soluble antioxidants and cholesterol oxides were measured in plasma of 11 patients with mild essential hypertension (H: 57.8 ± 9.7 years; blood pressure, 148.3 ± 24.8/90.8 ± 10.2 mmHg and in 11 healthy subjects (N: 48.4 ± 7.0 years; blood pressure, 119.4 ± 9.4/75.0 ± 8.0 mmHg.Nitrite, nitrate and S-nitrosothiols were measured by chemiluminescence and nitrotyrosine was determined by ELISA. Antioxidants were determined by reverse-phase HPLC and cholesterol oxides by gas chromatography. Hypertensive patients had reduced endothelium-dependent vasodilation in response to reactive hyperemia (H: 9.3 and N: 15.1% increase of diameter 90 s after hyperemia, and lower levels of ascorbate (H: 29.2 ± 26.0, N: 54.2 ± 24.9 µM, urate (H: 108.5 ± 18.9, N: 156.4 ± 26.3 µM, ß-carotene (H: 1.1 ± 0.8, N: 2.5 ± 1.2 nmol/mg cholesterol, and lycopene (H: 0.4 ± 0.2, N: 0.7 ± 0.2 nmol/mg cholesterol, in plasma, compared to normotensive subjects. The content of 7-ketocholesterol, 5alpha-cholestane-3ß,5,6ß-triol and 5,6alpha-epoxy-5alpha-cholestan-3alpha-ol in LDL, and the concentration of endothelin-1 (H: 0.9 ± 0.2, N: 0.7 ± 0.1 ng/ml in plasma were increased in hypertensive patients. No differences were found for ·NO derivatives between groups. These data suggest that an increase in cholesterol oxidation is associated with endothelium dysfunction in essential hypertension and oxidative stress, although ·NO metabolite levels in plasma are not modified in the presence of elevated cholesterol oxides.

  1. Plasma etching of polystyrene latex particles for the preparation of graphene oxide nanowalls

    Directory of Open Access Journals (Sweden)

    Bon Bittolo Silvia

    2012-01-01

    Full Text Available Graphene oxide nanowalls were prepared by casting a water dispersion of polystyrene latex particles onto a graphene oxide film followed by tetrafluoromethane plasma etching. Mild plasma etching conditions allow one to retain the oxygen functional groups on the graphene oxide nanowalls. It was found that the exposure to a xenon light source of such graphene oxide nanowalls coated with a gold thin film results in an increase of the electrical conductivity.

  2. Protective action of proanthocyanidin fraction from Medemia argun nuts against oxidative/nitrative damages of blood platelet and plasma components.

    Science.gov (United States)

    Morel, Agnieszka; Hamed, Arafa I; Oleszek, Wieslaw; Stochmal, Anna; Głowacki, Rafał; Olas, Beata

    2014-01-01

    The oxidative/nitrative stress induced by different factors plays an important role in the pathogenesis of various disorders, including cardiovascular diseases and cancer. Proanthocyanidins have antioxidative properties and may protect biomolecules (lipids, DNA, and proteins) exposed to reactive oxygen and nitrogen species, including peroxynitrite (ONOO(-)). The effects of proanthocyanidin fraction from Medemia argun nuts on oxidative/nitrative protein damages (determined by such parameters as level of thiol groups, carbonyl groups, and nitrotyrosine residues) and on the amount of glutathione (as an important component of redox status; using HPLC) in human blood platelets and plasma after treatment with peroxynitrite were studied in vitro. The preincubation of blood platelets and plasma with proanthocyanidin fraction from M. argun nuts (0.5-50 µg/ml) reduced the formation of 3-nitrotyrosine, diminished oxidation of thiol groups, and decreased the level of carbonyl groups in proteins caused by 100 µM peroxynitrite. An action of tested plant fraction and ONOO(-) evoked a significant increase of GSH in platelets and plasma in comparison with platelets and plasma treated with ONOO(-) only. The proanthocyanidin fraction from M. argun nuts can be useful as a protecting factor against oxidative/nitrative stress associated with different diseases (cancer, cardiovascular, and neurodegenerative diseases) and proanthocyanidins of M. argun nuts may be promising antioxidants.

  3. Oxidative stress and plasma lipoproteins in cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Maia, Fernanda Maria Machado; Santos, Emanuelly Barbosa; Reis, Germana Elias [Universidade Estadual do Ceará, Fortaleza, CE (Brazil)

    2014-07-01

    To evaluate the relation between oxidative stress and lipid profile in patients with different types of cancer. This was an observational cross-sectional. A total of 58 subjects were evaluated, 33 males, divided into two groups of 29 patients each: Group 1, patients with cancer of the digestive tract and accessory organs; Group 2 patients with other types of cancers, all admitted to a public hospital. The plasma levels (lipoproteins and total cholesterol, HDL, and triglycerides, for example) were analyzed by enzymatic kits, and oxidative stress based on thiobarbituric acid-reactive substances, by assessing the formation of malondialdehyde. In general the levels of malondialdehyde of patients were high (5.00μM) as compared to 3.31μM for healthy individuals. The median values of lipids exhibited normal triacylglycerol (138.78±89.88mg/dL), desirable total cholesterol values (163.04±172.38mg/dL), borderline high LDL (151.30±178.25mg/dL) and low HDL (31.70±22.74mg/dL). Median HDL levels in Group 1 were lower (31.32mg/dL) than the cancer patients in Group 2 (43.67mg/dL) (p=0.038). Group 1 also showed higher levels of oxidative stress (p=0.027). The lipid profile of patients with cancer was not favorable, which seems to have contributed to higher lipid peroxidation rate, generating a significant oxidative stress.

  4. Influence of plasma peening on oxidation of H13 hot work steel in water vapor

    Institute of Scientific and Technical Information of China (English)

    MIN Yong-an; XU Xiao; WU Xiao-chun; LI Lin; XU Luo-ping

    2004-01-01

    The surface oxidation films on H13 steel samples, obtained by different oxidation processes were observed by optical microscope. It is shown that the oxidation speed of H13 steel is increased remarkably due to the surface modification of plasma peening. Further researches were made by XRD, SEM and EDS. The activation of H13 surface caused by plasma peening and the subsequent higher oxygen diffusion rate into the steel seem to be the main reasons of higher oxidation speed. The nitride layer, generally formed on the steel surface under plasma nitriding process, can be substituted by oxide in subsequent oxidation process, which can reduce the risk of heat cracking in some hot work applications. Therefore, the plasma nitriding plus oxidation process is a proper choice for some hot work dies, which demands high hardness to avoid indentation as well as high toughness to avoid cracks.

  5. Synthesis of copper/copper oxide nanoparticles by solution plasma

    Science.gov (United States)

    Saito, Genki; Hosokai, Sou; Tsubota, Masakatsu; Akiyama, Tomohiro

    2011-07-01

    This paper describes the synthesis of copper/copper oxide nanoparticles via a solution plasma, in which the effect of the electrolyte and electrolysis time on the morphology of the products was mainly examined. In the experiments, a copper wire as a cathode was immersed in an electrolysis solution of a K2CO3 with the concentration from 0.001 to 0.50 M or a citrate buffer (pH = 4.8), and was melted by the local-concentration of current. The results demonstrated that by using the K2CO3 solution, we obtained CuO nanoflowers with many sharp nanorods, the size of which decreased with decreasing the concentration of the solution. Spherical particles of copper with/without pores formed when the citrate buffer was used. The pores in the copper nanoparticles appeared when the applied voltage changed from 105 V to 130 V, due to the dissolution of Cu2O.

  6. Fundamentals and applications of the combination of plasma nitrocarburizing and oxidizing

    Energy Technology Data Exchange (ETDEWEB)

    Hoppe, S. [METAPLAS IONON Oberflaechenveredelungstechnik GmbH, Bergisch-Gladbach (Germany)

    1998-01-01

    With the so-called IONIT {sup trademark} OX process, a combined plasma nitrocarburizing and oxidizing, iron based materials, especially non-alloyed steel, had been treated. It is shown that the oxidation of the nitrocarburized layers lead to a significant improvement of the corrosion resistance. The basic fundamentals of the formation of the oxide layer on nitrocarburized surfaces are discussed. The results of metallographic examinations explain the technological figures. Inspections of the oxide layer growth kinetics show a parabolic law. The growth rate depends on the oxidation temperature. Properties of plasma nitrocarburized and further oxidized components are summarized. Examples are given which demonstrate the wide range of potential applications. (orig.) 16 refs.

  7. Plasma Accelerator Development for Dynamic Formation of Plasma Liners: A Status Report

    Science.gov (United States)

    Thio, Y. C. Francis; Eskridge, Richard; Martin, Adam; Smith, James; Lee, Michael; Rodgers, Stephen L. (Technical Monitor)

    2001-01-01

    An experimental plasma accelerator for magnetic target fusion (MTF) applications under development at the NASA Marshall Space Flight Center is described. The accelerator is a pulsed plasma thruster and has been tested experimentally and plasma jet velocities of approximately 50 km/sec have been obtained. The plasma jet structure has been photographed with 10 ns exposure times to reveal a stable and repeatable plasma structure. Data for velocity profile information has been obtained using light pipes embedded in the gun walls to record the plasma transit at various barrel locations. Preliminary spatially resolved spectral data and magnetic field probe data are also presented. A high speed triggering system has been developed and tested as a means of reducing the gun "jitter". This jitter is being characterized and future work for second generation "ultra-low jitter" gun development is being identified.

  8. Relationship between sound signal and weld pool status in plasma arc welding

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The sound features of the weld pool status in plasma arc welding were systematically investigated after the sound signal was collected with a microphone. The results show that it is difficult to extract information about the weld pool status directly in time domain although the sound signal varies with the weld pool behaviors to some extent. The frequency spectra of the sound signal contain plenty of information about the weld pool behaviors. It is shown from the analysis of the sound generation mechanism that the sound signal of plasma arc welding is mainly caused by the weld pool oscillation, the power source fluctuation and so on. RS algorithm is designed to determine the weld pool status, and it is able to offer the feedback information for the closed-loop control of the penetration quality of plasma arc welding.

  9. Immune response in a wild bird is predicted by oxidative status, but does not cause oxidative stress.

    Science.gov (United States)

    Cram, Dominic L; Blount, Jonathan D; York, Jennifer E; Young, Andrew J

    2015-01-01

    The immune system provides vital protection against pathogens, but extensive evidence suggests that mounting immune responses can entail survival and fecundity costs. The physiological mechanisms that underpin these costs remain poorly understood, despite their potentially important role in shaping life-histories. Recent studies involving laboratory models highlight the possibility that oxidative stress could mediate these costs, as immune-activation can increase the production of reactive oxygen species leading to oxidative stress. However, this hypothesis has rarely been tested in free-ranging wild populations, where natural oxidative statuses and compensatory strategies may moderate immune responses and their impacts on oxidative status. Furthermore, the possibility that individuals scale their immune responses according to their oxidative status, conceivably to mitigate such costs, remains virtually unexplored. Here, we experimentally investigate the effects of a phytohaemagglutinin (PHA) immune-challenge on oxidative status in wild male and female white-browed sparrow weavers, Plocepasser mahali. We also establish whether baseline oxidative status prior to challenge predicts the scale of the immune responses. Contrary to previous work on captive animals, our findings suggest that PHA-induced immune-activation does not elicit oxidative stress. Compared with controls (n = 25 birds), PHA-injected birds (n = 27 birds) showed no evidence of a differential change in markers of oxidative damage or enzymatic and non-enzymatic antioxidant protection 24 hours after challenge. We did, however, find that the activity of a key antioxidant enzyme (superoxide dismutase, SOD) prior to immune-activation predicted the scale of the resulting swelling: birds with stronger initial SOD activity subsequently produced smaller swellings. Our findings (i) suggest that wild birds can mount immune responses without suffering from systemic oxidative stress, and (ii) lend support to

  10. Inflammatory cytokines and plasma redox status responses in hypertensive subjects after heat exposure

    Directory of Open Access Journals (Sweden)

    S.F. Fonseca

    2016-03-01

    Full Text Available Hypertension is characterized by a pro-inflammatory status, including redox imbalance and increased levels of pro-inflammatory cytokines, which may be exacerbated after heat exposure. However, the effects of heat exposure, specifically in individuals with inflammatory chronic diseases such as hypertension, are complex and not well understood. This study compared the effects of heat exposure on plasma cytokine levels and redox status parameters in 8 hypertensive (H and 8 normotensive (N subjects (age: 46.5±1.3 and 45.6±1.4 years old, body mass index: 25.8±0.8 and 25.6±0.6 kg/m2, mean arterial pressure: 98.0±2.8 and 86.0±2.3 mmHg, respectively. They remained at rest in a sitting position for 10 min in a thermoneutral environment (22°C followed by 30 min in a heated environmental chamber (38°C and 60% relative humidity. Blood samples were collected before and after heat exposure. Plasma cytokine levels were measured using sandwich ELISA kits. Plasma redox status was determined by thiobarbituric acid reactive substances (TBARS levels and ferric reducing ability of plasma (FRAP. Hypertensive subjects showed higher plasma levels of IL-10 at baseline (P<0.05, although levels of this cytokine were similar between groups after heat exposure. Moreover, after heat exposure, hypertensive individuals showed higher plasma levels of soluble TNF receptor (sTNFR1 and lower TBARS (P<0.01 and FRAP (P<0.05 levels. Controlled hypertensive subjects, who use angiotensin-converting-enzyme inhibitor (ACE inhibitors, present an anti-inflammatory status and balanced redox status. Nevertheless, exposure to a heat stress condition seems to cause an imbalance in the redox status and an unregulated inflammatory response.

  11. Fast low-temperature plasma reduction of monolayer graphene oxide at atmospheric pressure

    Science.gov (United States)

    Bodik, Michal; Zahoranova, Anna; Micusik, Matej; Bugarova, Nikola; Spitalsky, Zdenko; Omastova, Maria; Majkova, Eva; Jergel, Matej; Siffalovic, Peter

    2017-04-01

    We report on an ultrafast plasma-based graphene oxide reduction method superior to conventional vacuum thermal annealing and/or chemical reduction. The method is based on the effect of non-equilibrium atmospheric-pressure plasma generated by the diffuse coplanar surface barrier discharge in proximity of the graphene oxide layer. As the reduction time is in the order of seconds, the presented method is applicable to the large-scale production of reduced graphene oxide layers. The short reduction times are achieved by the high-volume power density of plasma, which is of the order of 100 W cm‑3. Monolayers of graphene oxide on silicon substrate were prepared by a modified Langmuir–Schaefer method and the efficient and rapid reduction by methane and/or hydrogen plasma was demonstrated. The best results were obtained for the graphene oxide reduction in hydrogen plasma, as verified by x-ray photoelectron spectroscopy and Raman spectroscopy.

  12. Vitamin C affects the antioxidative/oxidative status in rats irradiated with ultraviolet (UV) and infrared (IR) light

    DEFF Research Database (Denmark)

    Niemiec, T.; Sawosz, E.; Chwalibog, André

    2006-01-01

    Four grups of twenty growing Wistar rats were irradiated with either UV, IR, UV+IR light or were not irradiated (control). Ten rats from each group received a diet supplemented with 0.6% of L-ascorbic acid. The effects of the mega-dose of vitamin C were evaluated by changes in the antioxidative....../oxidative status. UV and IR radiation promoted oxidative DNA degradation in rat livers and supplementation with ascorbic acid strengthened the prooxidative effects on DNA oxidation in rats irradiated with UV or IR light. Vitamin C also increased the tiobarbituric acid reactive substances (TBARS) concentration...... in rats from all groups except UV+IR-irradiated. The combined UV+IR light, corresponding to solar radiation, had no negative effects on redox homeostasis in rats. Furthermore, L-ascorbic acid showed antioxidative properties by increasing the concentration of Total Antioxidative State (TAS) in plasma...

  13. Reduction of a thin chromium oxide film on Inconel surface upon treatment with hydrogen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Vesel, Alenka, E-mail: alenka.vesel@guest.arnes.si [Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Mozetic, Miran [Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Balat-Pichelin, Marianne [PROMES-CNRS Laboratory, 7 Rue du four solaire, 66120 Font Romeu Odeillo (France)

    2016-11-30

    Highlights: • Oxidized Inconel alloy was exposed to hydrogen at temperatures up to 1500 K. • Oxide reduction in hydrogen plasma started at approximately 1300 K. • AES depth profiling revealed complete reduction of oxides in plasma. • Oxides were not reduced, if the sample was heated just in hydrogen atmosphere. • Surface of reduced Inconel preserved the same composition as the bulk material. - Abstract: Inconel samples with a surface oxide film composed of solely chromium oxide with a thickness of approximately 700 nm were exposed to low-pressure hydrogen plasma at elevated temperatures to determine the suitable parameters for reduction of the oxide film. The hydrogen pressure during treatment was set to 60 Pa. Plasma was created by a surfaguide microwave discharge in a quartz glass tube to allow for a high dissociation fraction of hydrogen molecules. Auger electron depth profiling (AES) was used to determine the decay of the oxygen in the surface film and X-ray diffraction (XRD) to measure structural modifications. During hydrogen plasma treatment, the oxidized Inconel samples were heated to elevated temperatures. The reduction of the oxide film started at temperatures of approximately 1300 K (considering the emissivity of 0.85) and the oxide was reduced in about 10 s of treatment as revealed by AES. The XRD showed sharper substrate peaks after the reduction. Samples treated in hydrogen atmosphere under the same conditions have not been reduced up to approximately 1500 K indicating usefulness of plasma treatment.

  14. The effect of conjugated linoleic acid supplements on oxidative and antioxidative status of dairy cows.

    Science.gov (United States)

    Hanschke, N; Kankofer, M; Ruda, L; Höltershinken, M; Meyer, U; Frank, J; Dänicke, S; Rehage, J

    2016-10-01

    Dairy cows develop frequently negative energy balance around parturition and in early lactation, resulting in excessive mobilization of body fat and subsequently in increased risk of ketosis and other diseases. Dietary conjugated linoleic acid (CLA) supplements are used in dairy cows mainly for their depressing effect on milk fat content, but are also proposed to have antioxidative properties. As negative energy balance is associated with oxidative stress, which is also assumed to contribute to disease development, the present study was conducted to examine effects of CLA on oxidative and antioxidative status of lactating dairy cows. German Holstein cows (primiparous n=13, multiparous n=32) were divided into 3 dietary treatment groups receiving 100g/d of control fat supplement, containing 87% stearic acid (CON; n=14), 50g/d of control fat supplement and 50g/d of CLA supplement (CLA 50; n=15), or 100g/d of CLA supplement (CLA 100; n=16). The CLA supplement was lipid-encapsulated and contained 12% of trans-10,cis-12 CLA and cis-9,trans-11 CLA each. Supplementation took place between d1 and 182 postpartum; d 182 until 252 postpartum served as a depletion period. Blood was sampled at d -21, 1, 21, 70, 105, 140, 182, 224, and 252 relative to calving. The antioxidative status was determined using the ferric-reducing ability of plasma, α-tocopherol, α-tocopherol-to-cholesterol mass ratio, and retinol. For determination of oxidative status concentrations of hydroperoxides, thiobarbituric acid-reactive substances (TBARS), N'-formylkynurenine, and bityrosine were measured. Mixed models of fixed and random effects with repeated measures were used to evaluate period 1 (d -21 to 140) and 2 (d182-252) separately. Cows showed increased oxidative stress and lipid peroxidation during the periparturient period in terms of increased serum concentrations of hydroperoxides and TBARS, which decreased throughout lactation. During period 1, the supplemented cows had lower TBARS

  15. Blood oxidative stress biomarkers: influence of sex, exercise training status, and dietary intake.

    Science.gov (United States)

    Bloomer, Richard J; Fisher-Wellman, Kelsey H

    2008-09-01

    Sex and lifestyle factors are known to influence the oxidation of protein, lipids, and DNA. Biomarkers such as protein carbonyls (PC), malondialdehyde (MDA), and 8-hydroxydeoxyguanosine (8-OHdG) have been commonly used in an attempt to characterize the oxidative status of human subjects. This study compared resting blood oxidative stress biomarkers, in relation to exercise training status and dietary intake, between men and women. Exercise-trained and sedentary men and women (with normal menstrual cycles; reporting during the early follicular phase) were recruited from the University of Memphis, Tennessee, campus and surrounding community via recruitment flyers and word of mouth. Participants were categorized by sex and current exercise training status (ie, trained or untrained). Each completed a detailed 5-day food record of all food and drink consumed. Diets were analyzed for kilocalories and macro- and micronutrient (vitamins C, E, A) intake. Venous blood samples were obtained at rest and analyzed for PC, MDA, and 8-OHdG. In the 131 participants (89 men, of whom 74 were exercise trained and 15 untrained, and 42 women, of whom 22 were exercise trained and 20 untrained; mean [SD] age, 24 [4] years), PC did not differ significantly between trained men and women or between untrained men and women. However, trained participants had significantly lower plasma PC (measured in nmol . mg protein(-1)) (mean [SEM] 0.0966 [0.0055]) than did untrained participants (0.1036 [0.0098]) (P women (0.4264 [0.0559]) compared with trained men (0.6959 [0.0593]); in trained men and women combined (0.5621 [0.0566]) compared with untrained men and women combined (0.7397 [0.0718]); and in women combined (0.5665 [0.0611]) compared with men combined (0.7338 [0.0789]) (P men (r = 0.552; P = 0.033). MDA was positively correlated to protein intake and negatively correlated to percent of carbohydrate and vitamin C intake, primarily in trained men (P women than in men and in trained compared

  16. Probable preventive effects of placenta from oxidative stress; Evaluation of total antioxidant status, total oxidant status and oxidative stress index in fetal cord blood during the delivery.

    Science.gov (United States)

    Camkurt, Mehmet Akif; Fındıklı, Ebru; Tolun, Fatma İnanç; Bakacak, Murat; Bal, Nilay Gül; Sakallı, Hilal; Güneş, Mehmet

    2016-06-30

    Depression in pregnancy may have negative effects on birth outcomes. It may also effect the intrauterine environment of the fetus. The umbilical cord is the conduit between the fetus and placenta, and functions in the transport between fetus and mother. Investigating biochemical parameters in fetal cord blood (FCB) during delivery may be helpful to understanding to what the fetus is exposed to, at least in the last trimester. In this study, we aimed to investigate total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) in the FCB of depressed mothers and healthy controls during delivery. Our study included 33 depressed mothers and 37 healthy controls. TAS, TOS, and OSI were measured according to Erel's method. We found that TAS, TOS, and OSI levels were similar in patients and healthy controls; however, the birth weights of depressed patients were significantly lower than those of healthy controls. Our results suggest that the placental barrier may prevent from oxidative stress. Future studies should include blood samples collected simultaneously from mothers during delivery. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. The Main Plasma Chemical Process of Nitric Oxide Production by Arc Discharge%The Main Plasma Chemical Process of Nitric Oxide Production by Arc Discharge

    Institute of Scientific and Technical Information of China (English)

    杨旗; 胡辉; 陈卫鹏; 许杰; 张锦丽; 吴双

    2011-01-01

    By adopting the optical multi-channel analyzer combined with fourier transform infrared (FTIR) spectrometer, the dominant free radicals and products generated by arc discharge were measured and studied, and the main plasma chemical reaction process in the nitric oxide production by arc discharge was identified. Plasma chemical kinetic curves of O, O2, N2, N and NO were simulated by using CHEMKIN and MATLAB. The results show that the main plasma chemical reaction process of nitric oxide production by arc discharge is a replacement reaction between O and N2, where NO can be generated instantaneously when discharging reaches stable.

  18. Alteration of Oxidative Status in Rats Following Administration of Acrylamide

    Directory of Open Access Journals (Sweden)

    Hanaa H. El-Sayed1, Shawkia S. Abd El- Halim1,

    2007-09-01

    Full Text Available Introduction: Acrylamide (ACR is a known industrial neurotoxic and carcinogenic chemical in rodents. The recent discovery of acrylamide in wide variety of commonly consumed foods has energized research efforts worldwide to define toxic mechanisms. Objective: The present study is carried out to investigate the effect of acrylamide administration on in vivo malondialdehyde (MDA, a product of lipid peroxidation, reduced glutathione (GSH as well as copper and zinc superoxide dismutase enzyme activity (Cu/Zn SOD of rats. Material and Methods: Fourteen adult male Sprague Dawley rats were divided into two groups each containing "7" rats. Group 1 served as negative control fed on basal diet and group 2 (positive control received basal diet and acrylamide (0.34g/ kg diet for 11 days. Levels of MDA, GSH and activity of SOD were determined in liver, kidneys, brain, heart, testes, spleen and lungs of rats. Results: ACR treatment significantly increased MDA in all organs; the highest increase was detected in testis (87.9% and heart (71.5% while the lowest one was found in kidneys (28.2%. On the other hand, GSH levels and SOD activities were significantly reduced in ACR treated rats. However, the reduction of GSH level ranged from 10.2% to 36.5 %.The inhibition of SOD activities were higher in testis (57.3% and lungs (38.5%. Conclusion: The present study showed that ACR exerts deteriorated effects on oxidative status of rats

  19. Interaction between sexual steroids and immune response in affecting oxidative status of birds

    NARCIS (Netherlands)

    Casagrande, Stefania; Costantini, David; Groothuis, Ton G. G.

    2012-01-01

    One hypothesis explaining the honesty of secondary sexual traits regulated by testosterone (T) is that T can impair the balance between pro-oxidant compounds and antioxidant defences, favouring a status of oxidative stress that only good quality individuals can sustain (oxidative handicap

  20. Plasma Thruster Development: Magnetoplasmadynamic Propulsion, Status and Basic Problems.

    Science.gov (United States)

    1986-02-01

    Closed Drift Hall-Ion Thruster Flown on the Russian Satellite Meteor I, 1971, from Reference 13 12 4 Flat Coil Induction Thruster Schematic from...the Russian Satellite Meteor 1, 1971. from Ref. 1-3. 13 COIL Br PLASMA SWITCH0 0 FZ jeBr 0 CAPACITOR 0 Fig.- 4:Fa olInuto huse ceai fromRef-22 40 14 is...minute crater (on the order of 10- 4 cm diameter). High pressures, on the order of 100 bar, and vaporization rates in these craters have been

  1. Effects of Sulla forage (Sulla coronarium L.) on the oxidative status and milk polyphenol content in goats.

    Science.gov (United States)

    Di Trana, A; Bonanno, A; Cecchini, S; Giorgio, D; Di Grigoli, A; Claps, S

    2015-01-01

    Twelve milking Girgentana goats were allocated into 3 groups and fed 3 diets ad libitum in a 3×3 Latin square design with 3 periods. The diets were Sulla fresh forage ad libitum (SUL), Sulla fresh forage ad libitum and 800g/d of barley meal (SULB), and mixed hay ad libitum and 800g/d of barley meal (HB). Changes were observed in total polyphenol intake, plasma oxidative status, plasma polyphenol content, metabolic status, milk polyphenol content, and total antioxidant capacity. The fresh forage diets (SUL and SULB) increased dry matter, total polyphenol, nontannic polyphenol and tannin intakes, and the milk total protein, casein, milk total polyphenols, and milk free polyphenols compared with the HB diet. The intake of condensed tannins was higher in the SUL than in the HB group, and an intermediate value was recorded for the SULB group. Plasma from the SUL- and SULB-fed goats exhibited greater total antioxidant capacity and greater total polyphenol and free polyphenol levels compared with the plasma from the HB group. Positive correlations between plasma total antioxidant capacity and condensed tannins intake (r=0.43), plasma total polyphenol and total polyphenol intake (r=0.61), and plasma free polyphenol and milk total polyphenols (r=0.38) were observed. The correlation between milk free polyphenols and whey total antioxidant capacity (r=0.42) highlights the role of free polyphenols in the determination of the antioxidant activity of milk. These results indicate that Sulla fresh forage exerts an antioxidant activity due to its secondary compounds that provide additional antioxidant value and that Sulla forage appears to be a promising strategy for improving product quality.

  2. Plasma Markers of Oxidative Stress in Patients with Gestational Diabetes Mellitus in the Second and Third Trimester

    Science.gov (United States)

    Ouyang, Zhenbo

    2016-01-01

    Objective. To determine plasma markers of oxidative stress during the second and third trimester of pregnancy in patients with gestational diabetes mellitus (GDM). Study Design. We conducted a prospective nested case-control study involving 400 pregnant women, 22 of whom developed GDM. As control group, 30 normal pregnant women were chosen randomly. Plasma samples were analyzed for 8-iso-prostaglandin F2α (8-iso-PGF2α), advanced oxidative protein products (AOPPs), protein carbonyl (PCO), glutathione peroxidase-3 (GPX-3), and paraoxonase-1 (PON1) at 16–20 weeks, 24–28 weeks, and 32–36 weeks of gestation. Results. Compared to control subjects, the plasma levels of PCO, AOPPs, and 8-iso-PGF2α were elevated at 16–20 weeks' and 32–36 weeks' gestation in GDM. There was no significant difference in PCO and 8-iso-PGF2α at 24–28 weeks in GDM. GPX-3 was statistically significantly increased at 16–20 weeks and 32–36 weeks in GDM. PON1 reduced in patients with GDM. No significant differences were found at 24–28 and 32–36 weeks between the GDM and control groups. In GDM, PCO, AOPPs, and 8-iso-PGF2α levels were higher and GPX-3 and PON1 levels were lower in the second than the third trimester. Conclusion. Oxidation status increased in GDM, especially protein oxidation, which may contribute to the pathogenesis of GDM. PMID:27803713

  3. Circulating and PBMC Lp-PLA2 associate differently with oxidative stress and subclinical inflammation in nonobese women (menopausal status.

    Directory of Open Access Journals (Sweden)

    Jean Kyung Paik

    Full Text Available BACKGROUND: This study aimed to determine the association of lipoprotein-associated phospholipase A(2 (Lp-PLA(2 activity in circulation and peripheral blood mononuclear cells (PBMCs with inflammatory and oxidative stress markers in nonobese women and according to menopausal status. Lp-PLA(2 activity, a marker for cardiovascular risk is associated with inflammation and oxidative stress. METHODOLOGY/PRINCIPAL FINDINGS: Eighty postmenopausal women (53.0±4.05 yr and 96 premenopausal women (39.7±9.25 yr participated in this study. Lp-PLA(2 activities, interleukin (IL-6, tumor necrosis factor (TNF-α, and IL-1β in plasma as well as in PBMCs were measured. Plasma ox-LDL was also measured. Postmenopausal women demonstrated higher circulating levels of ox-LDL and IL-6, as well as IL-6, TNF-α, and IL-1β in PBMCs, than premenopausal women. In both groups, plasma Lp-PLA(2 activity positively correlated with Lp-PLA(2 activity in PBMCs and plasma ox-LDL. In premenopausal women, Lp-PLA(2 activities in plasma and PBMCs positively correlated with IL-6, TNF-α, and IL-1β in PBMCs. In postmenopausal women, plasma ox-LDL positively correlated with PBMC cytokine production. In subgroup analysis of postmenopausal women according to plasma ox-LDL level (median level: 48.715 U/L, a significant increase in Lp-PLA(2 activity in the plasma but not the PBMCs was found in the high ox-LDL subgroup. Plasma Lp-PLA(2 activity positively correlated with unstimulated PBMC Lp-PLA(2 activity in the low ox-LDL subgroup (r = 0.627, P<0.001, whereas in the high ox-LDL circulating Lp-PLA(2 activity positively correlated with plasma ox-LDL (r = 0.390, P = 0.014 but not with Lp-PLA(2 activity in PBMCs. CONCLUSIONS/SIGNIFICANCE: The lack of relation between circulating Lp-PLA(2 activity and Lp-PLA(2 activity in PBMCs was found in postmenopausal women with high ox-LDL. This may indicate other sources of circulating Lp-PLA(2 activity except PBMC in postmenopausal women

  4. Peroxisome Proliferator-Activated Receptor Activation is Associated with Altered Plasma One-Carbon Metabolites and B-Vitamin Status in Rats.

    Science.gov (United States)

    Lysne, Vegard; Strand, Elin; Svingen, Gard F T; Bjørndal, Bodil; Pedersen, Eva R; Midttun, Øivind; Olsen, Thomas; Ueland, Per M; Berge, Rolf K; Nygård, Ottar

    2016-01-05

    Plasma concentrations of metabolites along the choline oxidation pathway have been linked to increased risk of major lifestyle diseases, and peroxisome proliferator-activated receptors (PPARs) have been suggested to be involved in the regulation of key enzymes along this pathway. In this study, we investigated the effect of PPAR activation on circulating and urinary one-carbon metabolites as well as markers of B-vitamin status. Male Wistar rats (n = 20) received for 50 weeks either a high-fat control diet or a high-fat diet with tetradecylthioacetic acid (TTA), a modified fatty acid and pan-PPAR agonist with high affinity towards PPARα. Hepatic gene expression of PPARα, PPARβ/δ and the enzymes involved in the choline oxidation pathway were analyzed and concentrations of metabolites were analyzed in plasma and urine. TTA treatment altered most biomarkers, and the largest effect sizes were observed for plasma concentrations of dimethylglycine, nicotinamide, methylnicotinamide, methylmalonic acid and pyridoxal, which were all higher in the TTA group (all p Pparα mRNA was increased after TTA treatment, but genes of the choline oxidation pathway were not affected. Long-term TTA treatment was associated with pronounced alterations on the plasma and urinary concentrations of metabolites related to one-carbon metabolism and B-vitamin status in rats.

  5. Rapid Deposition of Titanium Oxide and Zinc Oxide Films by Solution Precursor Plasma Spray

    Science.gov (United States)

    Ando, Yasutaka

    In order to develop a high rate atmospheric film deposition process for functional films, as a basic study, deposition of titanium oxide film and zinc oxide film by solution precursor plasma spray (SPPS) was conducted in open air. Consequently, in the case of titanium oxide film deposition, anantase film and amorphous film as well as rutile film could be deposited by varying the deposition distance. In the case of anatase dominant film, photo-catalytic properties of the films could be confirmed by wettability test. In addition, the dye sensitized sollar cell (DSC) using the TiO2 film deposited by this SPPS technique as photo voltaic device generates 49mV in OCV. On the other hand, in the case of zinc oxide film deposition, it was proved that well crystallized ZnO films with photo catalytic properties could be deposited. From these results, this process was found to have high potential for high rate functional film deposition process conducted in the air.

  6. Preparation and Characterization of Plasma-Sprayed Ultrafine Chromium Oxide Coatings

    Institute of Scientific and Technical Information of China (English)

    LIN Feng; JIANG Xianliang; YU Yueguang; ZENG Keli; REN Xianjing; LI Zhenduo

    2007-01-01

    Ultrafine chromium oxide coatings were prepared by plasma spraying with ultrafine feedstock. Processing parameters of plasma spraying were optimized. Optical microscope (OM) was used to observe the microstructure of the ultrafine chromium oxide coatings. Scanning electron microscopy (SEM) was used to observe the morphology and particle size of ultrafine powder feedstock as well as to examine the microstructure of the chromium oxide coating. In addition, hardness and bonding strength of the ultrafine chromium oxide coatings were measured.The results showed that the optimized plasma spraying parameters were suitable for ultrafine chromium oxide coating and the properties and microstructure of the optimized ultrafine chromium oxide coating were superior compared to conventional chromium oxide wear resistant coatings.

  7. Quark-gluon plasma: Status of heavy ion physics

    Indian Academy of Sciences (India)

    R V Gavai

    2000-07-01

    Lattice quantum chromodynamics (QCD), defined on a discrete space–time lattice, leads to a spectacular non-perturbative prediction of a new state of matter, called quark-gluon plasma (QGP), at sufficiently high temperatures or equivalently large energy densities. The experimental programs of CERN, Geneva and BNL, New York of relativistic heavy ion collisions are expected to produce such energy densities, thereby providing us a chance to test the above prediction. After a brief introduction of the necessary theoretical concepts, I will present a critical review of the experimental results already obtained by the various experiments in order to examine whether QGP has already been observed by them.

  8. Production of nitric oxide using a microwave plasma torch and its application to fungal cell differentiation

    Science.gov (United States)

    Na, Young Ho; Kumar, Naresh; Kang, Min-Ho; Cho, Guang Sup; Choi, Eun Ha; Park, Gyungsoon; Uhm, Han Sup

    2015-03-01

    The generation of nitric oxide by a microwave plasma torch is proposed for its application to cell differentiation. A microwave plasma torch was developed based on basic kinetic theory. The analytical theory indicates that nitric oxide density is nearly proportional to oxygen molecular density and that the high-temperature flame is an effective means of generating nitric oxide. Experimental data pertaining to nitric oxide production are presented in terms of the oxygen input in units of cubic centimeters per minute. The apparent length of the torch flame increases as the oxygen input increases. The various levels of nitric oxide are observed depending on the flow rate of nitrogen gas, the mole fraction of oxygen gas, and the microwave power. In order to evaluate the potential of nitric oxide as an activator of cell differentiation, we applied nitric oxide generated from the microwave plasma torch to a model microbial cell (Neurospora crassa: non-pathogenic fungus). Germination and hyphal differentiation of fungal cells were not dramatically changed but there was a significant increase in spore formation after treatment with nitric oxide. In addition, the expression level of a sporulation related gene acon-3 was significantly elevated after 24 h upon nitric oxide treatment. Increase in the level of nitric oxide, nitrite and nitrate in water after nitric oxide treatment seems to be responsible for activation of fungal sporulation. Our results suggest that nitric oxide generated by plasma can be used as a possible activator of cell differentiation and development.

  9. Betaine and folate status as cooperative determinants of plasma homocysteine in humans.

    NARCIS (Netherlands)

    Holm, P.I.; Ueland, P.M.; Vollset, S.E.; Midttun, O.; Blom, H.J.; Keijzer, M.B.; Heijer, M. den

    2005-01-01

    OBJECTIVE: Two published studies have demonstrated that betaine in the circulation is a determinant of plasma total homocysteine, but none had sufficient power to investigate the possible effect modification by folate status. METHODS AND RESULTS: We measured homocysteine, betaine, folate, vitamin B(

  10. Improving electrical properties of sol-gel derived zinc oxide thin films by plasma treatment

    Science.gov (United States)

    Talukder, Al-Ahsan; Pokharel, Jyotshna; Shrestha, Maheshwar; Fan, Qi H.

    2016-10-01

    Being a direct and wide bandgap semiconductor, zinc oxide is a suitable material for various optoelectronic applications. These applications require tuning and controlling over the electrical and optical properties of zinc oxide films. In this work, zinc oxide thin films were prepared by a solution method that led to oriented crystal growth along (002) plane. The zinc oxide thin films were treated with oxygen, hydrogen, and nitrogen plasmas. The films were characterized to reveal the effects of plasma treatments on transmittance, crystallinity, carrier density, carrier mobility, and electrical resistivity. Oxygen plasma treatment improved the crystallinity of the zinc oxide thin film without affecting the film's transmittance. Hydrogen plasma treatments were found very effective in improving the electrical conductivity sacrificing the film's transmittance. Nitrogen plasma treatment led to improved electrical conductivity without compromising the crystallinity and optical transmittance. Sequential oxygen, hydrogen, and nitrogen plasma treatments significantly reduced the resistivity of zinc oxide thin films by over two orders and maintained the transmittance close to the as-deposited films of ˜80% in visible wavelength range. This is the first work on the improvement of conductivity of solution-based zinc oxide films using the plasma treatment.

  11. Associations between nitric oxide synthase genes and exhaled NO-related phenotypes according to asthma status.

    Directory of Open Access Journals (Sweden)

    Emmanuelle Bouzigon

    Full Text Available BACKGROUND: The nitric oxide (NO pathway is involved in asthma, and eosinophils participate in the regulation of the NO pool in pulmonary tissues. We investigated associations between single nucleotide polymorphisms (SNPs of NO synthase genes (NOS and biological NO-related phenotypes measured in two compartments (exhaled breath condensate and plasma and blood eosinophil counts. METHODOLOGY: SNPs (N = 121 belonging to NOS1, NOS2 and NOS3 genes were genotyped in 1277 adults from the French Epidemiological study on the Genetics and Environment of Asthma (EGEA. Association analyses were conducted on four quantitative phenotypes: the exhaled fraction of NO (Fe(NO, plasma and exhaled breath condensate (EBC nitrite-nitrate levels (NO2-NO3 and blood eosinophils in asthmatics and non-asthmatics separately. Genetic heterogeneity of these phenotypes between asthmatics and non-asthmatics was also investigated. PRINCIPAL FINDINGS: In non-asthmatics, after correction for multiple comparisons, we found significant associations of Fe(NO levels with three SNPs in NOS3 and NOS2 (P ≤ 0.002, and of EBC NO2-NO3 level with NOS2 (P = 0.002. In asthmatics, a single significant association was detected between Fe(NO levels and one SNP in NOS3 (P = 0.004. Moreover, there was significant heterogeneity of NOS3 SNP effect on Fe(NO between asthmatics and non-asthmatics (P = 0.0002 to 0.005. No significant association was found between any SNP and NO2-NO3 plasma levels or blood eosinophil counts. CONCLUSIONS: Variants in NO synthase genes influence Fe(NO and EBC NO2-NO3 levels in adults. These genetic determinants differ according to asthma status. Significant associations were only detected for exhaled phenotypes, highlighting the critical relevance to have access to specific phenotypes measured in relevant biological fluid.

  12. Lipid components and oxidative status of selected specialty oils

    Energy Technology Data Exchange (ETDEWEB)

    Madawala, S. R. P.; Kochhar, S. P.; Dutta, P. C.

    2012-11-01

    Many vegetable oils are marketed as specialty oils because of their retained flavors, tastes and distinct characteristics. Specialty oil samples which were commercially produced and retailed were purchased from local superstores in Reading, UK, and Uppsala, Sweden and profiled for detailed lipid composition and oxidative status. These oil samples include: almond, hazelnut, walnut, macadamia nut, argan, avocado, grape seed, roasted sesame, rice bran, cold pressed, organic and cold pressed, warm pressed and refined rapeseed oils. The levels of PV were quite low (0.5-1.3mEq O{sub 2}/kg) but AV and Rancimat values at 100 degree centigrade (except for rapeseed oils) varied considerably at (0.5-15.5) and (4.2-37.0 h) respectively. Macadamia nut oil was found to be the most stable oil followed by argan oil, while walnut oil was the least stable. Among the specialty oils, macadamia nut oil had the lowest (4%) and walnut oil had the highest (71%) level of total PUFA. The organic cold pressed rapeseed oil had considerably lower PUFA (27%) compared with other rapeseed oils (28- 35%). In all the samples, {alpha}- and {gamma}- tocopherols were the major tocopherols; nut oils had generally lower levels. Total sterols ranged from 889 to 15,106 {mu}g/g oil. The major sterols were {beta}-sitosterol (61-85%) and campesterol (6-20%). Argan oil contained schottenol (35%) and spinasterol (32%). Compared with literature values, no marked differences were observed among the differently processed, organically grown or cold pressed rapeseed oils and other specialty oils in this study. (Author) 33 refs.

  13. Peptide translocation through the plasma membrane of human cells: Can oxidative stress be exploited to gain better intracellular access?

    Science.gov (United States)

    Wang, Ting-Yi; Pellois, Jean-Philippe

    2016-01-01

    Cell-penetrating peptides (CPPs) enter cells primarily by escaping from endosomal compartments or by directly translocating across the plasma membrane. Due to their capability of permeating into the cytosolic space of the cell, CPPs are utilized for the delivery of cell-impermeable molecules. However, the fundamental mechanisms and parameters associated with the penetration of CPPs and their cargos through the lipid bilayer have not been fully determined. This in turn has hampered their usage in biotechnological or therapeutic applications. We have recently reported that the cell penetration activity of poly-arginine CPPs (PACPPs) is dependent on the oxidation status of the plasma membrane of cells. Our data support a model where the positively-charged PACPP binds negatively-charged lipids exposed on the cell surface as a result of oxidative damage. The PACPP then crosses the membrane via formation of inverted micelles with these anionic lipids. This model provides a plausible explanation for the high variability in the cell delivery efficiency of a PACPP often observed in different settings. Notably, taking into account the current literature describing the effects of lipid oxidation, our data point to a highly complex and underappreciated interplay between PACPPs and oxidized membrane species. Overall, a better understanding of oxidation-dependent cell penetration might provide a fundamental basis for development of optimal cell permeable peptides (including cyclic peptides, stapled peptides, peptoids, etc…) and of robust delivery protocols.

  14. Plasma antioxidant status in healthy smoking and non-smoking men.

    Science.gov (United States)

    Goraca, A; Skibska, B

    2005-01-01

    Human serum contains many different antioxidants which may be important in the maintenance of an antioxidant status. The aim of this study was to evaluate the relationship between lipid peroxidation and total plasma antioxidant capacity in healthy smoking and non-smoking young and elderly subjects. Plasma concetrations of alpha-tocopherol, beta-carotene and ascorbic acid were detected by HPLC. Additionally, in the in vitro experiments, the effects of exogenous compounds (ascorbic acid, uric acid, Trolox) on total ferric reducing activity of plasma were tested. We demonstrated that total antioxidant capacity of plasma obtained from healthy non-smoking young subjects was significantly higher than plasma antioxidant capacity of smoking elderly subjects. The concentration of thiobarbituric acid-reactive substances (TBARS) (p < 0.001) in young non-smoking volunteers was lower than that in young smokers. The concentration of TBARS in elderly non-smoking volunteers was lower than in elderly smokers. Plasma concentrations of alpha-tocopherol, beta-carotene and ascorbic acid were significantly lower in elderly smokers than in elderly non-smokers of same age. No difference in plasma levels of alpha-tocopherol, beta-carotene and ascorbic acid were found in 22-year-old smoking and non-smoking subjects. In vitro addition of ascorbic acid, uric acid, or Trolox to plasma samples significantly increased their total antioxidant capacity. Decrease of FRAP values and increase of TBARS concentra-' tions is a significant physiologic condition of aging process. Supplementation of antioxidants could be useful for the enhancement of plasma antioxidant status (Tab. 1, Fig. 3, Ref: 35).

  15. Individuals with hematological malignancies before undergoing chemotherapy present oxidative stress parameters and acute phase proteins correlated with nutritional status.

    Science.gov (United States)

    Camargo, Carolina de Quadros; Borges, Dayanne da Silva; de Oliveira, Paula Fernanda; Chagas, Thayz Rodrigues; Del Moral, Joanita Angela Gonzaga; Durigon, Giovanna Steffanello; Dias, Bruno Vieira; Vieira, André Guedes; Gaspareto, Patrick; Trindade, Erasmo Benício Santos de Moraes; Nunes, Everson Araújo

    2015-01-01

    Hematological malignancies present abnormal blood cells that may have altered functions. This study aimed to evaluate nutritional status, acute phase proteins, parameters of cell's functionality, and oxidative stress of patients with hematological malignancies, providing a representation of these variables at diagnosis, comparisons between leukemias and lymphomas and establishing correlations. Nutritional status, C-reactive protein (CRP), albumin, phagocytic capacity and superoxide anion production of mononuclear cells, lipid peroxidation and catalase activity in plasma were evaluated in 16 untreated subjects. Main diagnosis was acute leukemia (n = 9) and median body mass index (BMI) indicated overweight (25.6 kg/m(2)). Median albumin was below (3.2 g/dL) and CRP above (37.45 mg/L) the reference values. Albumin was inversely correlated with BMI (r = -0.53). Most patients were overweight before the beginning of treatment and had a high CRP/albumin ratio, which may indicate a nutrition inflammatory risk. BMI values correlated positively with lipid peroxidation and catalase activity. A strong correlation between catalase activity and lipid peroxidation was found (r = 0.75). Besides the elevated BMI, these patients also have elevated CRP values and unexpected relations between nutritional status and albumin, reinforcing the need for nutritional counseling during the course of chemotherapy, especially considering the correlations between oxidative stress parameters and nutritional status evidenced here.

  16. Effect of Multicomponent Training on Blood Pressure, Nitric Oxide, Redox Status, and Physical Fitness in Older Adult Women: Influence of Endothelial Nitric Oxide Synthase (NOS3 Haplotypes

    Directory of Open Access Journals (Sweden)

    Atila Alexandre Trapé

    2017-01-01

    Full Text Available The purpose of this study was to verify the influence of the genotype or haplotype (interaction of the NOS3 polymorphisms [-786T>C, 894G>T (Glu298Asp, and intron 4b/a] on the response to multicomponent training (various capacities and motor skills on blood pressure (BP, nitrite concentration, redox status, and physical fitness in older adult women. The sample consisted of 52 participants, who underwent body mass index and BP assessments. Physical fitness was evaluated by six-minute walk, elbow flexion, and sit and stand up tests. Plasma/blood samples were used to evaluate redox status, nitrite concentration, and genotyping. Associations were observed between isolated polymorphisms and the response of decreased systolic and diastolic BP and increased nitrite concentration and antioxidant activity. In the haplotype analysis, the group composed of ancestral alleles (H1 was the only one to present improvement in all variables studied (decrease in systolic and diastolic BP, improvement in nitrite concentration, redox status, and physical fitness, while the group composed of variant alleles (H8 only demonstrated improvement in some variables of redox status and physical fitness. These findings suggest that NOS3 polymorphisms and physical training are important interacting variables to consider in evaluating redox status, nitric oxide availability and production, and BP control.

  17. Modeling of evaporation and oxidation phenomena in plasma spraying of metal powders

    Science.gov (United States)

    Zhang, Hanwei

    Plasma spraying of metals in air is usually accompanied by evaporation and oxidation of the sprayed material. Optimization of the spraying process must ensure that the particles are fully molten during their short residence time in the plasma jet and prior to hitting the substrate, but not overheated to minimize evaporation losses. In atmospheric plasma spraying (ASP), it is also clearly desirable to be able to control the extent of oxide formation. The objective of this work to develop an overall mathematical model of the oxidization and volatilization phenomena involved in the plasma-spraying of metallic particles in air atmosphere. Four models were developed to simulate the following aspects of the atmospheric plasma spraying (APS) process: (a) the particle trajectories and the velocity and temperature profiles in an Ar-H 2 plasma jet, (b) the heat and mass transfer between particles and plasma jet, (c) the interaction between the evaporation and oxidation phenomena, and (d) the oxidation of liquid metal droplets. The resulting overall model was generated by adapting the computational fluid dynamics code FIDAP and was validated by experimental measurements carried out at the collaborating plasma laboratory of the University of Limoges. The thesis also examined the environmental implications of the oxidization and volatilization phenomena in the plasma spraying of metals. The modeling results showed that the combination of the standard k-s model of turbulence and the Boussinesq eddy-viscosity model provided a more accurate prediction of plasma gas behavior. The estimated NOx generation levels from APS were lower than the U.S.E.P.A. emission standard. Either enhanced evaporation or oxidation can occur on the surface of the metal particles and the relative extent is determined by the process parameters. Comparatively, the particle size has the greatest impact on both evaporation and oxidation. The extent of particle oxidation depends principally on gas

  18. Unfiltered Diesel Engine Exhaust Treatment by Discharge Plasma:Effect of Soot Oxidation

    Institute of Scientific and Technical Information of China (English)

    B. S. Rajanikanth; Subhankar Das; A. D. Srinivasan

    2004-01-01

    A cascaded system of electrical discharges (Non-thermal plasma), catalyst and adsorption process was investigated for the removal of oxides of nitrogen (NO x) and carbon monoxide (CO) from a Diesel engine raw exhaust. The three processes were separately studied first, and then the cascaded processes, namely plasma-catalyst and plasma-adsorbent, were investigated. In this paper main emphasis was laid on the effect of carbonaceous soot oxidation on the plasma treatment process. While the cascaded plasma-catalyst process exhibits a higher CO removal, the cascaded plasma-adsorbent process exhibits a higher NO x removal. The experiments were conducted under no-load. The plasma and adsorbent reactors were kept at room temperature throughout the experiment while the catalyst reactor was kept at 200oC / 300oC.

  19. Bioactive constituents from "triguero" asparagus improve the plasma lipid profile and liver antioxidant status in hypercholesterolemic rats.

    Science.gov (United States)

    Vázquez-Castilla, Sara; De la Puerta, Rocío; Garcia Gimenez, María Dolores; Fernández-Arche, María Angeles; Guillén-Bejarano, Rafael

    2013-10-24

    We have previously shown that the Andalusian-cultivated Asparagus officinalis L. "triguero" variety produces hypocholesterolemic and hepatoprotective effects on rats. This asparagus is a rich source of phytochemicals although we hypothesized there would be some of them more involved in these functional properties. Thus, we aimed to study the effects of asparagus (500 mg/kg body weight (bw)/day) and their partially purified fractions in flavonoids (50 mg/kg bw/day), saponins (5 mg/kg bw/day) and dietary fiber (500 mg/kg bw/day) on oxidative status and on lipid profile in rats fed a cholesterol-rich diet. After 5 weeks treatment, plasma lipid values, hepatic enzyme activities and liver malondialdehyde (MDA) concentrations were measured. With the exception of the saponin fraction (SF), the administration of lyophilized asparagus (LA), fiber fraction (FF), and flavonoid fraction (FVF) to hypercholesterolemic rats produced a significant hypolipidemic effect compare to a high-cholesterol diet (HCD). In addition, the LA and FVF groups exhibited a significant increase in enzyme activity from multiple hepatic antioxidant systems including: superoxide dismutase, catalase, and gluthatione reductase/peroxidase as well as a decrease in MDA concentrations compared to HCD group. These results demonstrate that "triguero" asparagus possesses bioactive constituents, especially dietary fiber and flavonoids, that improve the plasma lipid profile and prevent hepatic oxidative damage under conditions of hypercholesterolemia.

  20. Bioactive Constituents from “Triguero” Asparagus Improve the Plasma Lipid Profile and Liver Antioxidant Status in Hypercholesterolemic Rats

    Directory of Open Access Journals (Sweden)

    Rafael Guillén-Bejarano

    2013-10-01

    Full Text Available We have previously shown that the Andalusian-cultivated Asparagus officinalis L. “triguero” variety produces hypocholesterolemic and hepatoprotective effects on rats. This asparagus is a rich source of phytochemicals although we hypothesized there would be some of them more involved in these functional properties. Thus, we aimed to study the effects of asparagus (500 mg/kg body weight (bw/day and their partially purified fractions in flavonoids (50 mg/kg bw/day, saponins (5 mg/kg bw/day and dietary fiber (500 mg/kg bw/day on oxidative status and on lipid profile in rats fed a cholesterol-rich diet. After 5 weeks treatment, plasma lipid values, hepatic enzyme activities and liver malondialdehyde (MDA concentrations were measured. With the exception of the saponin fraction (SF, the administration of lyophilized asparagus (LA, fiber fraction (FF, and flavonoid fraction (FVF to hypercholesterolemic rats produced a significant hypolipidemic effect compare to a high-cholesterol diet (HCD. In addition, the LA and FVF groups exhibited a significant increase in enzyme activity from multiple hepatic antioxidant systems including: superoxide dismutase, catalase, and gluthatione reductase/peroxidase as well as a decrease in MDA concentrations compared to HCD group. These results demonstrate that “triguero” asparagus possesses bioactive constituents, especially dietary fiber and flavonoids, that improve the plasma lipid profile and prevent hepatic oxidative damage under conditions of hypercholesterolemia.

  1. Laughing Gas in a Pediatric Emergency Department-Fun for All Participants: Vitamin B12 Status Among Medical Staff Working With Nitrous Oxide.

    Science.gov (United States)

    Staubli, Georg; Baumgartner, Matthias; Sass, Jörn Oliver; Hersberger, Martin

    2016-12-01

    The efficiency of nitrous oxide in an equimolar mixture with oxygen or in concentrations up to 70% is approved for short painful procedures. Evaluation of the vitamin B12 levels in anesthetic staff applying nitrous oxide showed reduced vitamin B12 plasma levels. This study examines the vitamin B12 status of medical staff working with nitrous oxide in a pediatric emergency department (ED). Medical staff of the ED at the University Children's Hospital Zurich participated. The vitamin B12 status was evaluated by measuring homocysteine, methylmalonic acid, vitamin B12, blood count, and the MTHFR C677T genotype. As a control group, medical personnel working in the "nitrous oxide-free" pediatric intensive care unit were recruited.

  2. Thermal conductivities of nanostructured magnesium oxide coatings deposited on magnesium alloys by plasma electrolytic oxidation.

    Science.gov (United States)

    Shen, Xinwei; Nie, Xueyuan; Hu, Henry

    2014-10-01

    The resistances of magnesium alloys to wear, friction and corrosion can be effectively improved by depositing coatings on their surfaces. However, the coatings can also reduce the heat transfer from the coated components to the surroundings (e.g., coated cylinder bores for internal combustion of engine blocks). In this paper, nanostructured magnesium oxides were produced by plasma electrolytic oxidation (PEO) process on the magnesium alloy AJ62 under different current densities. The guarded comparative heat flow method was adopted to measure the thermal conductivities of such coatings which possess gradient nanoscale grain sizes. The aim of the paper is to explore how the current density in the PEO process affects the thermal conductivity of the nanostructured magnesium coatings. The experimental results show that, as the current density rises from 4 to 20 A/mm2, the thermal conductivity has a slight increase from 0.94 to 1.21 W/m x K, which is significantly smaller than that of the corresponding bulk magnesium oxide materials (29.4 W/m x K). This mostly attributed to the variation of the nanoscale grain sizes of the PEO coatings.

  3. Plasma levels of interleukin-10 and nitric oxide in response to two different desflurane anesthesia flow rates

    Directory of Open Access Journals (Sweden)

    Dilek Kalayci

    2014-07-01

    Full Text Available OBJECTIVE: This study investigated interleukin-10 and nitric oxide plasma levels following surgery to determine whether there is a correlation between these two variables and if different desflurane anesthesia flow rates influence nitric oxide and interleukin-10 concentrations in circulation. MATERIALS AND METHODS: Forty patients between 18 and 70 years and ASA I-II physical status who were scheduled to undergo thyroidectomy were enrolled in the study. INTERVENTIONS: Patients were allocated into two groups to receive two different desflurane anesthesia flow rates: high flow (Group HF and low flow (Group LF. MEASUREMENTS: Blood samples were drawn at the beginning (t 0 and end (t 1 of the operation and after 24 h (t 2. Plasma interleukin-10 and nitric oxide levels were measured using an enzyme-linked-immunosorbent assay and a Griess reagents kit, respectively. Hemodynamic and respiratory parameters were assessed. RESULTS: There was no statistically significant difference between the two groups with regard to interleukin-10 levels at the times of measurement. Interleukin-10 levels were increased equally in both groups at times t 1 and t 2 compared with preoperative concentrations. For both groups, nitric oxide circulating concentrations were significantly reduced at times t 1 and t 2 compared with preoperative concentrations. However, the nitric oxide value was lower for Group HF compared to Group LF at t 2. No correlation was found between the IL-10 and nitric oxide levels. CONCLUSION: Clinical usage of two different flow anesthesia forms with desflurane may increase interleukin-10 levels both in Group HF and Group LF; nitric oxide levels circulating concentrations were significantly reduced at times t 1 and t 2 compared with preoperative concentrations; however, at 24 h postoperatively they were higher in Group LF compared to Group HF. No correlation was detected between interleukin-10 and nitric oxide levels.

  4. [Plasma levels of interleukin-10 and nitric oxide in response to two different desflurane anesthesia flow rates].

    Science.gov (United States)

    Kalayci, Dilek; Dikmen, Bayazit; Kaçmaz, Murat; Taşpınar, Vildan; Ornek, Dilşen; Turan, Ozlem

    2014-01-01

    This study investigated interleukin-10 and nitric oxide plasma levels following surgery to determine whether there is a correlation between these two variables and if different desflurane anesthesia flow rates influence nitric oxide and interleukin-10 concentrations in circulation. Forty patients between 18 and 70 years and ASA I-II physical status who were scheduled to undergo thyroidectomy were enrolled in the study. Patients were allocated into two groups to receive two different desflurane anesthesia flow rates: high flow (Group HF) and low flow (Group LF). Blood samples were drawn at the beginning (t0) and end (t1) of the operation and after 24h (t2). Plasma interleukin-10 and nitric oxide levels were measured using an enzyme-linked-immunosorbent assay and a Griess reagents kit, respectively. Hemodynamic and respiratory parameters were assessed. There was no statistically significant difference between the two groups with regard to interleukin-10 levels at the times of measurement. Interleukin-10 levels were increased equally in both groups at times t1 and t2 compared with preoperative concentrations. For both groups, nitric oxide circulating concentrations were significantly reduced at times t1 and t2 compared with preoperative concentrations. However, the nitric oxide value was lower for Group HF compared to Group LF at t2. No correlation was found between the IL-10 and nitric oxide levels. Clinical usage of two different flow anesthesia forms with desflurane may increase interleukin-10 levels both in Group HF and Group LF; nitric oxide levels circulating concentrations were significantly reduced at times t1 and t2 compared with preoperative concentrations; however, at 24h postoperatively they were higher in Group LF compared to Group HF. No correlation was detected between interleukin-10 and nitric oxide levels. Copyright © 2013 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  5. Plasma levels of interleukin-10 and nitric oxide in response to two different desflurane anesthesia flow rates.

    Science.gov (United States)

    Kalaycı, Dilek; Dikmen, Bayazit; Kaçmaz, Murat; Taşpınar, Vildan; Ornek, Dilşen; Turan, Ozlem

    2014-01-01

    This study investigated interleukin-10 and nitric oxide plasma levels following surgery to determine whether there is a correlation between these two variables and if different desflurane anesthesia flow rates influence nitric oxide and interleukin-10 concentrations in circulation. Forty patients between 18 and 70 years and ASA I-II physical status who were scheduled to undergo thyroidectomy were enrolled in the study. Patients were allocated into two groups to receive two different desflurane anesthesia flow rates: high flow (Group HF) and low flow (Group LF). Blood samples were drawn at the beginning (t0) and end (t1) of the operation and after 24h (t2). Plasma interleukin-10 and nitric oxide levels were measured using an enzyme-linked-immunosorbent assay and a Griess reagents kit, respectively. Hemodynamic and respiratory parameters were assessed. There was no statistically significant difference between the two groups with regard to interleukin-10 levels at the times of measurement. Interleukin-10 levels were increased equally in both groups at times t1 and t2 compared with preoperative concentrations. For both groups, nitric oxide circulating concentrations were significantly reduced at times t1 and t2 compared with preoperative concentrations. However, the nitric oxide value was lower for Group HF compared to Group LF at t2. No correlation was found between the IL-10 and nitric oxide levels. Clinical usage of two different flow anesthesia forms with desflurane may increase interleukin-10 levels both in Group HF and Group LF; nitric oxide levels circulating concentrations were significantly reduced at times t1 and t2 compared with preoperative concentrations; however, at 24h postoperatively they were higher in Group LF compared to Group HF. No correlation was detected between interleukin-10 and nitric oxide levels. Copyright © 2013 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  6. Pyrroloquinoline quinone prevents oxidative stress-induced neuronal death probably through changes in oxidative status of DJ-1.

    OpenAIRE

    Nunome, Kana; Miyazaki, Shin; Nakano, Masahiko; Iguchi-Ariga, Sanae; Ariga, Hiroyoshi

    2008-01-01

    Pyrroloquinoline quinone (PQQ) has been shown to play a role as an anti-oxidant in neuronal cells and prevent neuronal cell death in a rodent stroke model. DJ-1, a causative gene product for a familial form of Parkinson's disease, plays a role in anti-oxidative stress function by self-oxidation of DJ-1. In this study, the expression level and oxidation status of DJ-1 were examined in SHSY-5Y cells and primary cultured neurons treated with 6-hydroxydopamine (6-OHDA) or H(2)O(2) in the presence...

  7. The influence of selenium status on body composition, oxidative DNA damage and total antioxidant capacity in newly diagnosed type 2 diabetes mellitus: A case-control study.

    Science.gov (United States)

    Othman, Fatimah Binti; Mohamed, Hamid Jan Bin Jan; Sirajudeen, K N S; Noh, Mohd Fairulnizal B Md; Rajab, Nor Fadilah

    2017-09-01

    Selenium is involved in the complex system of defense against oxidative stress in diabetes through its biological function of selenoproteins and the antioxidant enzyme. A case-control study was carried out to determine the association of plasma selenium with oxidative stress and body composition status presented in Type 2 Diabetes Mellitus (T2DM) patient and healthy control. This study involved 82 newly diagnosed T2DM patients and 82 healthy controls. Plasma selenium status was determined with Graphite Furnace Atomic Absorption Spectrometry. Body Mass Index, total body fat and visceral fat was assessed for body composition using Body Composition Analyzer (TANITA). Oxidative DNA damage and total antioxidant capacity were determined for oxidative stress biomarker status. In age, gender and BMI adjustment, no significant difference of plasma selenium level between T2DM and healthy controls was observed. There was as a significant difference of Oxidative DNA damage and total antioxidant capacity between T2DM patients and healthy controls with tail DNA% 20.62 [95% CI: 19.71,21.49] (T2DM), 17.67 [95% CI: 16.87,18.56] (control); log tail moment 0.41[95% CI: 0.30,0.52] (T2DM), 0.41[95% CI: 0.30,0.52] (control); total antioxidant capacity 0.56 [95% CI: 0.54,0.58] (T2DM), 0.60 [95% CI: 0.57,0.62] (control). Waist circumference, BMI, visceral fat, body fat and oxidative DNA damage in the T2DM group were significantly lower in the first plasma selenium tertile (38.65-80.90μg/L) compared to the second (80.91-98.20μg/L) and the third selenium tertiles (98.21-158.20μg/L). A similar trend, but not statistically significant, was observed in the control group. Copyright © 2016 Elsevier GmbH. All rights reserved.

  8. A Chilean Berry Concentrate Protects against Postprandial Oxidative Stress and Increases Plasma Antioxidant Activity in Healthy Humans

    Science.gov (United States)

    Ávila, Felipe; Echeverria, Guadalupe; Perez, Druso; Trejo, Sebastian; Leighton, Federico

    2017-01-01

    This study formulated and characterized an antioxidant-rich concentrate of berries (BPC-350) produced in Chile, which was used to perform a crossover study aimed at determining the effect of the berries on the modulation of plasma postprandial oxidative stress and antioxidant status. Healthy male volunteers (N = 11) were randomly assigned to three experimental meals: (1) 250 g of ground turkey burger (GTB) + 500 mL of water; (2) 250 g of GTB + 500 mL of 5% BPC-350; (3) 250 g of GTB prepared with 6% BPC-350 + 500 mL of 5% BPC-350. Venous blood samples were collected prior to meal intake and every hour for six hours after intake. Malondialdehyde (MDA), carbonyls in proteins, and DPPH (2,2-diphenyl-1-picrylhydrazyl) antioxidant capacity were quantified in plasma. Significant differences indicated that BPC-350 decreases MDA plasma concentration and protein carbonyls (p < 0.05). Additionally, a significant increase in the DPPH antioxidant capacity was observed in Meals 2 and 3 when compared to Meal 1 (p < 0.05). The results are discussed in terms of oxidative reactions that occur during digestion at the stomach level and the important effect of oxidative reactions that occur during the thermal processing of red meat. PMID:28243359

  9. A Chilean Berry Concentrate Protects against Postprandial Oxidative Stress and Increases Plasma Antioxidant Activity in Healthy Humans

    Directory of Open Access Journals (Sweden)

    Ines Urquiaga

    2017-01-01

    Full Text Available This study formulated and characterized an antioxidant-rich concentrate of berries (BPC-350 produced in Chile, which was used to perform a crossover study aimed at determining the effect of the berries on the modulation of plasma postprandial oxidative stress and antioxidant status. Healthy male volunteers (N=11 were randomly assigned to three experimental meals: (1 250 g of ground turkey burger (GTB + 500 mL of water; (2 250 g of GTB + 500 mL of 5% BPC-350; (3 250 g of GTB prepared with 6% BPC-350 + 500 mL of 5% BPC-350. Venous blood samples were collected prior to meal intake and every hour for six hours after intake. Malondialdehyde (MDA, carbonyls in proteins, and DPPH (2,2-diphenyl-1-picrylhydrazyl antioxidant capacity were quantified in plasma. Significant differences indicated that BPC-350 decreases MDA plasma concentration and protein carbonyls (p<0.05. Additionally, a significant increase in the DPPH antioxidant capacity was observed in Meals 2 and 3 when compared to Meal 1 (p<0.05. The results are discussed in terms of oxidative reactions that occur during digestion at the stomach level and the important effect of oxidative reactions that occur during the thermal processing of red meat.

  10. Idiopathic recurrent calcium urolithiasis (IRCU: pathophysiology evaluated in light of oxidative metabolism, without and with variation of several biomarkers in fasting urine and plasma - a comparison of stone-free and -bearing male patients, emphasizing mineral, acid-base, blood pressure and protein status*

    Directory of Open Access Journals (Sweden)

    Schwilie PO

    2011-08-01

    Full Text Available Abstract Background IRCU is traditionally considered as lifestyle disease (associations with, among others, overweight, obesity, hypertension, type-2 diabetes, arising from excess, in 24 h urine, of calcium (Ca salts (calcium oxalate (CaOx, calcium phosphate (CaPi, supersaturation of, and crystallization in, tubular fluid and urine, causing crystal-induced epithelial cell damage, proteinuria, crystal aggregation and uroliths. Methods Another picture emerges from the present uncontrolled study of 154 male adult IRCU patients (75 stone-bearing (SB and 79 age-matched stone-free (SF, in whom stone-forming and other parameters in fasting urine and plasma were contrasted with five biomarkers (see footnote of oxidative metabolism (OM, without and with variation of markers. Results 1 In SB vs. SF unstratified OM biomarkers were statistically unchanged, but the majority of patients was overweight; despite, in SB vs. SF urine pH, total and non-albumin protein concentration were elevated, fractional urinary uric acid excretion and blood bicarbonate decreased, whereas urine volume, sodium, supersaturation with CaOx and CaPi (as hydroxyapatite were unchanged; 2 upon variation of OM markers (strata below and above median numerous stone parameters differed significant!', among others urine volume, total protein, Ca/Pi ratio, pH, sodium, potassium, plasma Ca/Pi ratio and parathyroid hormone, blood pressure, renal excretion of non-albumin protein and other substances; 3 a significant shift from SF to SB patients occurred with increase of urine pH, decrease of blood bicarbonate, and increase of diastolic blood pressure, whereas increase of plasma uric acid impacted only marginally; 4 in both SF and SB patients a strong curvilinear relationship links a rise of urine Ca/Pi to urine Ca/Pi divided by plasma Ca/Pi, but in SB urine Ca/Pi failed to correlate significantly with urine hydroxyapatite supersaturation; 5 also in SB, plasma Ca/Pi and urinary nitrate were

  11. Pendulum support of the W7-X plasma vessel: Design, tests, manufacturing, assembly, critical aspects, status

    Energy Technology Data Exchange (ETDEWEB)

    Missal, B., E-mail: bernd.missal@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, EURATOM Association, Teilinstitut Greifswald, Wendelsteinstraße 1, D-17491 Greifswald (Germany); Leher, F.; Schiller, T. [MAN Diesel and Turbo SE, Werftstraße 17, 94469 Deggendorf (Germany); Friedrich, P. [Universität Rostock, FB Maschinenbau und Schiffstechnik, Albert-Einsteins-Straße 2, 18051 Rostock (Germany); Capriccioli, A. [ENEA Frascati, Fusion Technology Unit, Frascati (Italy)

    2014-10-15

    Highlights: • Plasma vessel support has to allow vertical adjustment and horizontal passive movement. • Planar sliding tables with PTFE do not fulfill all requirements. • Pendulums can fulfill all requirements. • Geometry and material of spherical bearings had to be optimized in calculations and tests. • Optimized pendulums were manufactured and assembled. - Abstract: The superconducting helical advanced stellarator Wendelstein 7-X (W7-X) is under construction at the Max-Planck-Institut für Plasmaphysik (IPP) in Greifswald, Germany. The three dimensional shape of plasma will be generated by 50 non-planar magnetic coils. The plasma vessel geometry follows exactly this three dimensional shape of plasma. To ensure the superconductivity of coils a cryo vacuum has to be generated. Therefore the coils and their support structure are enclosed within the outer vessel. Plasma vessel, coil structures and outer vessel have to be supported separately. This paper will describe the vertical supports of plasma vessel which have to fulfill two special requirements, vertical adjustability and horizontal mobility. These two tasks will be carried out by plasma vessel supports (PVS) with hydraulic cylinders, special sliding tables during assembly and pendulum supports during operating phase. The paper will give an overview of design, calculation, tests, fabrication, assembly, critical aspects and status of PVS.

  12. Oxidation behavior of niobized TiA1 by plasma surface alloying

    Institute of Scientific and Technical Information of China (English)

    Dongdong Chen; Wenhuai Tian; Jian Wang; Xiaoping Liu

    2008-01-01

    Plasma surface alloying of element Nb in TiM-based alloys and the oxidation behavior were studied. The composition and microstructure of the surface alloyed layers were investigated by means of scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and X-ray diffraction (XRD). The experimental results indicate that the diffusion layers are formed on the TiAl substrate during the plasma niobizing process. The result from oxidation resistance investigation shows that plasma niobizing greatly improves the oxidation resistance of TiAl compared with the untreated TiAI. The role of element Nb for improving the oxida-tion resistance is considered to be achieved by strengthening the activity of Al, which is induced by the plasma niobizing process.

  13. Analysis of plasma lipid peroxidation and antioxidant enzymes status in patients of oral leukoplakia: A case control study

    Science.gov (United States)

    Srivastava, Kumar Chandan; Shrivastava, Deepti

    2016-01-01

    Aims and Objectives: Imbalances between the oxidant-antioxidant status have been implicated in the pathogenesis of several diseases, including oral cancer. Mostly, all oral cancer lesions are preceded by a stage of premalignancy. The present study aims to evaluate lipid peroxidation and antioxidant status in the venous blood of patients with different clinicopathologic stages of leukoplakia. Materials and Methods: A case control study was designed with the inclusion of 20 new cases of histopathologically proven leukoplakia of various clinical stages along with an equal number of positive and negative control individuals. The concentrations of thiobarbituric acid reactive substances and the activities of the antioxidant enzymes, namely superoxide dismutase, reduced glutathione, glutathione peroxidase, and catalase, were estimated in plasma using spectrophotometric methods. The data are expressed as mean ± SD. The statistical comparisons between and within the study groups were performed by one-way analysis of variance followed by post hoc analysis. Karl Pearson correlation was performed for the biochemical parameters within the group and between the groups. For statistically significant correlations, simple linear regression was performed. Results: Significant enhanced lipid peroxidation (P leukoplakia patients compared with positive as well as negative controls. Accordingly, significant (P < 0.001) pattern of progression in thiobarbituric acid reactive substances levels was observed at various clinical stages among patients of both control groups. Among enzymes, glutathione showed significant (P < 0.001) reduction along the stages on comparison with two control groups. Conclusion: Enhanced lipid peroxidation and compromised antioxidant defense in plasma indicate the development of oxidative stress. Among the antioxidant enzymes, reduced glutathione and glutathione Pperoxidase may play a decisive role in malignant transformation. PMID:28217539

  14. Significance of Serum Total Oxidant/Antioxidant Status in Patients with Colorectal Cancer.

    Science.gov (United States)

    Wu, Rong; Feng, Jiafu; Yang, Yuwei; Dai, Chunmei; Lu, Anyang; Li, Jie; Liao, Yao; Xiang, Miao; Huang, Qingmei; Wang, Dong; Du, Xiao-Bo

    2017-01-01

    Oxidative stress is involved in a variety of diseases. Prospective studies investigating the relationship between oxidative stress biomarkers and the status and development of colorectal cancer (CRC) are scarce; previous studies have failed to establish a relationship between the serum total oxidant/antioxidant status and CRC. Therefore, we compared the total serum oxidant/antioxidant levels of CRC patients and healthy subjects, and analyzed their clinical significance in the CRC. Fasting blood samples from 132 CRC patients and 64 healthy subjects were collected. Oxidative stress parameters, including total oxidant status (TOS) and total antioxidant status (TAS), were measured, and the oxidative stress index (OSI) was calculated. The TOS and OSI levels increased significantly (POxidative stress parameters differed significantly depending on the patient's smoking and drinking status (P0.05).However, the levels of TOS, TAS, and OSI were significantly different between patients with no metastasis and those with metastases to two organs (P<0.05) Finally, the parameters are affected by smoking and drinking, and subsequent research should be conducted excluding the relevant influencing factors.

  15. Enhancement of corrosion resistance for plasma nitrided AISI 4140 steel by plain air plasma post-oxidizing

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jiqiang; Liu, Han; Ye, Xuemei [Jiangsu Key Laboratory of Materials Surface Technology, Changzhou University, Changzhou 213164 (China); Chai, Yating [Materials Research and Education Center, Auburn University, AL 36849 (United States); Hu, Jing, E-mail: jinghoo@126.com [Jiangsu Key Laboratory of Materials Surface Technology, Changzhou University, Changzhou 213164 (China); Materials Research and Education Center, Auburn University, AL 36849 (United States)

    2015-05-25

    Highlights: • Plain air was primarily used for plasma post-oxidation for AISI 4140 steel. • A thin iron oxide layer composed of Fe{sub 3}O{sub 4} to Fe{sub 2}O{sub 3} was formed on top of the compound layer. • The ratio of Fe{sub 3}O{sub 4} to Fe{sub 2}O{sub 3} was closely related to the post-oxidizing conditions. • Post-oxidizing at 673 K for 60 min brought out highest ratio of Fe{sub 3}O{sub 4} to Fe{sub 2}O{sub 3} and optimum corrosion resistance. - Abstract: Plasma post-oxidizing was conducted immediately after plasma nitriding in the same equipment for AISI 4140 steel, and plain air was used as the oxygen bearing gas. The cross-sectional microstructures of the treated samples were observed by optical metallography and scanning electron microcopy (SEM), and the thickness of compound layer was measured accordingly. The phases were determined by X-ray diffraction (XRD), corrosion resistance was evaluated by electrochemical polarization, and the surface morphology before and after polarization test was also observed by SEM. Meanwhile, standard Gibbs free energy of the oxidation reactions existed in Fe–O system was calculated. The results show that a thin iron oxide layer composed of magnetite (Fe{sub 3}O{sub 4}) and hematite (Fe{sub 2}O{sub 3}) is formed on top of the compound layer during plasma post-oxidizing process, and the ratio of magnetite (Fe{sub 3}O{sub 4}) to hematite (Fe{sub 2}O{sub 3}) is depended on plasma post-oxidizing temperature and time. Highest ratio of Fe{sub 3}O{sub 4} to Fe{sub 2}O{sub 3} is obtained while post-oxidizing at 673 K for 60 min due to lower standard Gibbs free energy and appropriate forming rate for the formation of Fe{sub 3}O{sub 4} at this temperature. The thin oxide layer brings out significant enhancement of corrosion resistance, especially at higher ratios of Fe{sub 3}O{sub 4} to Fe{sub 2}O{sub 3}, due to the dense and adherent characteristic of Fe{sub 3}O{sub 4} oxide. Surface images of the post-oxidizing specimen

  16. Plasma deuterium oxide accumulation following ingestion of different carbohydrate beverages.

    Science.gov (United States)

    Currell, Kevin; Urch, Joanna; Cerri, Erika; Jentjens, Roy L P; Blannin, Andy K; Jeukendrup, Asker E

    2008-12-01

    Optimal fluid delivery from carbohydrate solutions such as oral rehydration solutions or sports drinks is essential. The aim of the study was to investigate whether a beverage containing glucose and fructose would result in greater fluid delivery than a beverage containing glucose alone. Six male subjects were recruited (average age (+/-SD): 22 +/- 2 y). Subjects entered the laboratory between 0700 h and 0900 h after an overnight fast. A 600 mL bolus of 1 of the 3 experimental beverages was then given. The experimental beverages were water (W), 75 g glucose (G), or 50 g glucose and 25 g fructose (GF); each beverage also contained 3.00 g of D2O. Following administration of the experimental beverage subjects remained in a seated position for 180 min. Blood and saliva samples were then taken every 5 min in the first hour and every 15 min thereafter. Plasma and saliva samples were analyzed for deuterium enrichment by isotope ratio mass spectrometry. Deuterium oxide enrichments were compared using a 2-way repeated measures analysis of variance. The water trial (33 +/- 3 min) showed a significantly shorter time to peak than either G (82 +/- 40 min) or GF (59 +/- 25 min), but the difference between G and GF did not reach statistical significance. There was a significantly greater AUC for GF (55 673 +/- 10 020 delta per thousand vs. Vienna Standard Mean Ocean Water (VSMOW).180 min) and W (60 497 +/- 9864 delta per thousand vs. VSMOW.180 min) compared with G (46 290 +/- 9622 delta per thousand vs. VSMOW.180 min); W and GF were not significantly different from each other. These data suggest that a 12.5% carbohydrate beverage containing glucose and fructose results in more rapid fluid delivery in the first 75 min than a beverage containing glucose alone.

  17. Semiconductor photocatalysts for water oxidation: current status and challenges.

    Science.gov (United States)

    Yang, Lingling; Zhou, Han; Fan, Tongxiang; Zhang, Di

    2014-04-21

    Artificial photosynthesis is a highly-promising strategy to convert solar energy into hydrogen energy for the relief of the global energy crisis. Water oxidation is the bottleneck for its kinetic and energetic complexity in the further enhancement of the overall efficiency of the artificial photosystem. Developing efficient and cost-effective photocatalysts for water oxidation is a growing desire, and semiconductor photocatalysts have recently attracted more attention due to their stability and simplicity. This article reviews the recent advancement of semiconductor photocatalysts with a focus on the relationship between material optimization and water oxidation efficiency. A brief introduction to artificial photosynthesis and water oxidation is given first, followed by an explanation of the basic rules and mechanisms of semiconductor particulate photocatalysts for water oxidation as theoretical references for discussions of componential, surface structure, and crystal structure modification. O2-evolving photocatalysts in Z-scheme systems are also introduced to demonstrate practical applications of water oxidation photocatalysts in artificial photosystems. The final part proposes some challenges based on the dynamics and energetics of photoholes which are fundamental to the enhancement of water oxidation efficiency, as well as on the simulation of natural water oxidation that will be a trend in future research.

  18. Ascorbic acid protects lipids in human plasma and low-density lipoprotein against oxidative damage

    Energy Technology Data Exchange (ETDEWEB)

    Frei, B. (Department of Nutrition, Harvard School of Public Health, Boston, MA (Unites States))

    1991-12-01

    The authors exposed human blood plasma and low-density lipoprotein (LDL) to many different oxidative challenges and followed the temporal consumption of endogenous antioxidants in relation to the initiation of oxidative damage. Under all types of oxidizing conditions, ascorbic acid completely protects lipids in plasma and LDL against detectable peroxidative damage as assessed by a specific and highly sensitive assay for lipid peroxidation. Ascorbic acid proved to be superior to the other water-soluble plasma antioxidants bilirubin, uric acid, and protein thiols as well as to the lipoprotein-associated antioxidants alpha-tocopherol, ubiquinol-10, lycopene, and beta-carotene. Although these antioxidants can lower the rate of detectable lipid peroxidation, they are not able to prevent its initiation. Only ascorbic acid is reactive enough to effectively intercept oxidants in the aqueous phase before they can attack and cause detectable oxidative damage to lipids.

  19. Plasma oxidative stress biomarkers and progesterone profiles in a dairy cow diagnosed with an ovarian follicular cyst.

    Science.gov (United States)

    Talukder, S; Ingenhoff, L; Kerrisk, K L; Celi, P

    2014-01-01

    This study was conducted to examine the oxidative stress biomarkers in a cow diagnosed with a follicular cyst in her left ovary. Progesterone (P4) and plasma oxidative stress status was measured in 13 Holstein cows after synchronization of oestrus with controlled internal drug release (CIDR) and prostaglandinF2α (PGF2α) protocol. The presence and size of ovarian structures were monitored by transrectal ultrasound at 4 hourly intervals. Of the 13 cows, 12 were monitored until ovulation was detected and recorded, whereas one cow failed to ovulate and developed a follicular cyst. Oxidative stress biomarkers; reactive oxygen metabolites (ROMs), biological antioxidant potential (BAP), oxidative stress index (OSI), glutathione (GSH), ceruloplasmin and advanced oxidation protein products (AOPP) were measured in the cystic cow and compared to those of the 12 ovulated cows and are referred to as higher or lower if they are outside the mean ± standard error of mean of those of ovulated cows. The cystic cow had lower ROMs and OSI between 36 and 84 h after PGF2α injection and at 9 h, from 36 to 60 h after PGF2α injection respectively. On the other hand, antioxidant (BAP and GSH) was higher in the cystic cow compared to her ovulated herd mates. The observed imbalance between oxidant and antioxidant might have disrupted the physiological events for ovulation to occur, leading to cystic ovarian disease.

  20. Electrical properties of plasma-deposited silicon oxide clarified by chemical modeling

    NARCIS (Netherlands)

    Kovalgin, A.Y.; Boogaard, A.; Brunets, I.; Aarnink, A.A.I.; Wolters, R.A.M.

    2009-01-01

    Our study is focused on Plasma Enhanced Chemical Vapor Deposition (PECVD) of silicon dioxide films at low temperatures (< 150 oC) using Inductively Coupled (IC) High-Density (HD) plasma source. We recently fabricated Thin Film Transistors (TFTs) with high-quality ICPECVD gate oxides, which exhibited

  1. Plasma-enhanced Chemical Vapor Deposition of Aluminum Oxide Using Ultrashort Precursor Injection Pulses

    NARCIS (Netherlands)

    Dingemans, G.; M. C. M. van de Sanden,; Kessels, W. M. M.

    2012-01-01

    An alternative plasma-enhanced chemical vapor deposition (PECVD) method is developed and applied for the deposition of high-quality aluminum oxide (AlOx) films. The PECVD method combines a continuous plasma with ultrashort precursor injection pulses. We demonstrate that the modulation of the precurs

  2. OXIDANT/ANTIOXIDANT STATUS IN OBESE ADOLESCENT FEMALES WITH ACNE VULGARIS

    OpenAIRE

    Abulnaja Khalid

    2009-01-01

    Background and Objectives: Acne vulgaris is a distressing skin condition, which can carry with it significant psychological disability. Oxidant/antioxidant imbalance leads to increased production of free radicals, that cause many diseases. Some nutrients, along with systemic oxidative stress, have been implicated in acne vulgaris. The goal of the present study was to assess oxidant and antioxidant status in correlation with the incidence of acne vulgaris in adolescent obese females. Materia...

  3. Is oxidative status influenced by dietary carotenoid and physical activity after moult in the great tit (Parus major)?

    Science.gov (United States)

    Vaugoyeau, Marie; Decencière, Beatriz; Perret, Samuel; Karadas, Filiz; Meylan, Sandrine; Biard, Clotilde

    2015-07-01

    In the context of sexual and natural selection, an allocation trade-off for carotenoid pigments may exist because of their obligate dietary origin and their role both in the antioxidant and immune systems and in the production of coloured signals in various taxa, particularly birds. When birds have expended large amounts of carotenoids to feather growth such as after autumn moult, bird health and oxidative status might be more constrained. We tested this hypothesis in a bird species with carotenoid-based plumage colour, by manipulating dietary carotenoids and physical activity, which can decrease antioxidant capacity and increase reactive oxygen metabolite (ROM) concentration. Great tits were captured after moult and kept in aviaries, under three treatments: physical handicap and dietary supplementation with carotenoids, physical handicap and control diet, and no handicap and control diet. We measured plasma composition (antioxidant capacity, ROM concentration, and vitamin A, vitamin E and total carotenoid concentrations), immune system activation (blood sedimentation) and stress response (heterophil/lymphocyte ratio) and predicted that handicap treatment should influence these negatively and carotenoid supplementation positively. Coloration of yellow feathers was also measured. Carotenoid supplementation increased total plasma carotenoid concentration, decreased feather carotenoid chroma and marginally increased ROM concentration. Handicap increased blood sedimentation only in males but had no clear influence on oxidative stress, which contradicted previous studies. Further studies are needed to investigate how physical activity and carotenoid availability might interact and influence oxidative stress outside the moult period, and their combined potential influence on attractiveness and reproductive investment later during the breeding season.

  4. The effect of antioxidant supplementation on hepatitis C viral load, transaminases and oxidative status: a randomized trial among chronic hepatitis C virus-infected patients

    DEFF Research Database (Denmark)

    Groenbaek, K.; Friis, H.; Hansen, Max

    2006-01-01

    . During supplementation, the antioxidant group had significantly higher levels of plasma ascorbic acid and a-tocopherol than the placebo group and the activity of erythrocyte glutathione peroxidase had significantly increased from baseline to month 6. No differences were observed in serum alanine...... aminotransferase and logo-transformed plasma hepatitis C virus-RNA between the groups or changes from the baseline at any time. No consistent differences between groups or changes from the baseline with respect to erythrocyte activities of antioxidative enzymes (glutathione reductase, superoxide dismutase...... and catalase) or plasma levels of oxidative markers (malondialdehyde and 2-amino-adipic semialdehyde) were found. Conclusion Supplementation with vitamin C, E and selenium increased the antioxidant status, but had no effects on alanine aminotransferase, viral load or oxidative markers....

  5. Effects of Hybrid Voltages on Oxide Formation on 6061 Al-alloys During Plasma Electrolytic Oxidation

    Institute of Scientific and Technical Information of China (English)

    Kai Wang; Bon Heun Koo; Chan Gyu Lee; Young Joo Kim; Sunghun Lee; Eungsun Byon

    2009-01-01

    Plasma electrolytic oxidation (PEO) is carried out on 6061 Al-alloys in a weak alkaline electrolyte containing NaOH, Na_2SiO_3 and NaCl. Centered on the correlation of composition and structure, analyses by means of X-ray diffration (XRD), scanning electron microscope (SEM) and energy dispersive spectrometry (EDS) are conducted on the specimens, which have been PEO-treated under hybrid voltages of different direct current (DC) values (140-280 V) with constant alternate current (AC) amplitude (200 V). Attention is paid to the composition, properties and growth mechanism of oxide layers formed with hybrid voltages. Moreover, the main effects of DC value are discussed. Ceramic layers with a double-layer structure which combines hard outer and soft inner layers are found to be consist of α-Al_2O_3, γ-Al_2O_3 and mullite. With the DC values increasing, the growth of the ceramic layers tends to have increasingly obvious three-stage feature.

  6. Multinary wurtzite-type oxide semiconductors: present status and perspectives

    Science.gov (United States)

    Suzuki, Issei; Omata, Takahisa

    2017-01-01

    Oxide-based optoelectronic devices have been limited in applicable wavelength to the near-UV region because there are few viable binary wurtzite-type oxides, but ternary wurtzite-type (β-NaFeO2-type) oxides are promising materials to expand the applicable wavelengths of these devices. In the past decade, many attractive properties of β-NaFeO2-type oxide semiconductors have been revealed, such as the band-engineering of ZnO by alloying with β-LiGaO2 and β-AgGaO2, the photocatalytic activities of β-AgGaO2 and β-AgAlO2, and the discovery that β-CuGaO2 is suitable for thin-film solar-cell absorbers. In this review article, we consider previous studies of β-NaFeO2-type oxide semiconductors—β-LiGaO2, β-AgGaO2, β-AgAlO2, β-CuGaO2—and their alloys with ZnO, and discuss their structural features, optical and electrical properties, and the relationship between their crystal structures and electronic band structures. We describe the outlook of β-NaFeO2-type oxide semiconductors and the remaining issues that hinder the development of optoelectronic devices made from β-NaFeO2-type oxide semiconductors.

  7. Plasma glutathione and oxidized glutathione level, glutathione/oxidized glutathione ratio, and albumin concentration in complicated and uncomplicated falciparum malaria

    Institute of Scientific and Technical Information of China (English)

    Loeki Enggar Fitri; Agustin Iskandar; Teguh Wahju Sardjono; Ummu Ditya Erliana; Widya Rahmawati; Didi Candradikusuma; Utama Budi Saputra; Eko Suhartono; Bambang Setiawan; Erma Sulistyaningsih

    2016-01-01

    Objective: To compare the level of glutathione(GSH) and oxidized glutathione(GSSG),the ratio of GSH/GSSG and the concentration of albumin in plasma of patients with complicated and un-complicated falciparum malaria.Methods: This research was a cross sectional study using comparison analysis with the plasma GSH and GSSG, the ratio of plasma GSH/GSSG and the concentration of plasma albumin as variables. The complicated malaria patients were obtained from Dr. Saiful Anwar Hospital Malang, whereas uncomplicated malaria patients were obtained from the Regency of Pleihari South Kalimantan. Plasma GSH and GSSG levels were determined by the spectrophotometer at the wave length of 412 nm, whereas the concentration of albumin was determined by bromocresol green method in the p H of 4.1.Results: There were no significant differences between the level of plasma GSH and GSSG in complicated and uncomplicated malaria patients, as well as the ratio of plasma GSH/GSSG in the two groups(P = 0.373; P = 0.538; and P = 0.615, respectively, independent ttest). In contrast, the plasma albumin concentration in complicated malaria patients were significantly higher than uncomplicated malaria patients(P = 0.000, Mann Whitney U test).Conclusions: It can be concluded that the average of plasma GSH and GSSG level, also plasma GSH/GSSG ratio in complicated malaria are not different from uncomplicated malaria. Although plasma concentration of albumin in both groups is below the normal range,there is an increase in complicated malaria that might be as compensation of oxidative stress.

  8. Plasma glutathione and oxidized glutathione level, glutathione/oxidized glutathione ratio, and albumin concentration in complicated and uncomplicated falciparum malaria

    Institute of Scientific and Technical Information of China (English)

    Loeki Enggar Fitri; Erma Sulistyaningsih; Agustin Iskandar; Teguh Wahju Sardjono; Ummu Ditya Erliana; Widya Rahmawati; Didi Candradikusuma; Utama Budi Saputra; Eko Suhartono; Bambang Setiawan

    2016-01-01

    Objective: To compare the level of glutathione (GSH) and oxidized glutathione (GSSG), the ratio of GSH/GSSG and the concentration of albumin in plasma of patients with complicated and un-complicated falciparum malaria. Methods: This research was a cross sectional study using comparison analysis with the plasma GSH and GSSG, the ratio of plasma GSH/GSSG and the concentration of plasma albumin as variables. The complicated malaria patients were obtained from Dr. Saiful Anwar Hospital Malang, whereas uncomplicated malaria patients were obtained from the Regency of Pleihari South Kalimantan. Plasma GSH and GSSG levels were determined by the spectrophotometer at the wave length of 412 nm, whereas the concentration of albumin was determined by bromocresol green method in the pH of 4.1. Results: There were no significant differences between the level of plasma GSH and GSSG in complicated and uncomplicated malaria patients, as well as the ratio of plasma GSH/GSSG in the two groups (P=0.373;P=0.538;and P=0.615, respectively, independent t-test). In contrast, the plasma albumin concentration in complicated malaria patients were significantly higher than uncomplicated malaria patients (P=0.000, Mann Whitney U test). Conclusions: It can be concluded that the average of plasma GSH and GSSG level, also plasma GSH/GSSG ratio in complicated malaria are not different from uncomplicated ma-laria. Although plasma concentration of albumin in both groups is below the normal range, there is an increase in complicated malaria that might be as compensation of oxidative stress.

  9. Study on the Oxidant and Antioxidant Status in Vitiligo Patients

    Directory of Open Access Journals (Sweden)

    Fatma Hassan Shabaka*, Sawsan Khalifa EL- Sayed*,

    2007-09-01

    Full Text Available Backgrounds: The aetiology of vitiligo is still unknown. Several hypotheses have been proposed to explain vitiligo: genetic neural, immunological, self destructive, convergence hypothesis and oxidative stress hypothesis The current study is concerned with the oxidative stress hypothesis and how oxidants and antioxidants affect the pathogenesis of vitiligo. So, our aim is to determine the role of malondialdehyde and glutathione in the pathogenesis of vitiligo. The amount of malondialdehyde (oxidant and glutathione (antioxidant were measured in serum and in skin tissue in 30 vitiligo cases and 20 healthy controls Results: The study showed significant changes between patients and controls in glutathione level in blood and tissue samples. Also there were significant changes between patients and controls in malondialdehyde in blood and in tissue samples favoring that glutathione and malondialdehyde play a role in the pathogenesis of vitiligo.

  10. The tunable plasma synthesis of Pt-reduced graphene oxide nanocomposites

    Directory of Open Access Journals (Sweden)

    Yulong Ma

    2017-06-01

    Full Text Available Herein, we have developed Pt-plasma reduced graphene oxide (Pt/P-rGO catalysts displaying high overpotentials for methanol oxidation reaction (MOR through facile and tunable plasma treatments. We provide insight into the improved performance of these catalysts by combining electrochemical measurements with microscopic and spectroscopic characterization techniques. The analysis results showed that the Pt nanoparticles (NPs were successfully deposited on P-rGO. The deposition and uniformity of Pt NPs were influenced by tuning the discharge power of the plasma. The catalytic performance towards the methanol oxidation reaction is investigated. The Pt/P-rGO NPs composites under 100 W show the best electrocatalytic activity. These results were vital to the further application of graphene-based metal nanocomposites synthesized by plasma technology.

  11. Synthesis of bio-active titanium oxide coatings stimulated by electron-beam plasma

    Directory of Open Access Journals (Sweden)

    Vasilieva Tatiana

    2014-11-01

    Full Text Available Advantages of the electron-beam plasma (EBP for production of bioactive titanium oxide coatings were experimentally studied. The coatings were synthesized in EBP of oxygen on the surface of plane titanium substrates. A number of analytical techniques were used to characterize morphology, chemical composition, and structure of the synthesized titanium oxide. The analysis showed the titanium oxide (IV in the rutile form to predominate in the coatings composition.

  12. The copper recovery from cupric oxide catalysts by plasma reduction process

    Energy Technology Data Exchange (ETDEWEB)

    Imris, I.; Klenovcanova, A. [Technical Univ. of Kosice, Kosice (Slovakia). Dept. of Power Engineering

    2007-07-01

    A plasma reduction process was used to recover copper from cupric oxide catalysts. Two types of plasma reduction smelting tests were conducted to verify the thermodynamic calculations. The plasma reactor consisted of a cylindrical steel shell lined with a castable alumina and a graphite crucible. Cupric oxide catalyst ESM 461 was mixed with stoichiometric amounts of carbon reductant and a 10 per cent addition of calcium oxide flux. Results of the experimental tests and the thermodynamic analysis showed that the copper can be extracted from cupric oxide using the plasma reduction process. Copper recovery was limited by physico-chemical copper losses. Copper oxide solubility was relatively high, so that copper recovery was low in their first series of plasma tests. The addition of calcium oxide flux improved copper recovery rates when dicalcium silicate was formed in the slag. The offgas samples indicated that concentrations of carbon monoxide (CO) in the gas phase was very high. It was concluded that the process is both commercially feasible and does not produce liquid or solid wastes. 7 refs., 2 tabs., 4 figs.

  13. Ultrathin oxide grown on polysilicon by using an electron cyclotron resonance N sub 2 O plasma

    CERN Document Server

    Han, S Y

    2000-01-01

    We have developed a process for growing ultrathin oxide on a polysilicon layer by using an electron cyclotron resonance (ECR) N sub 2 O plasma. Sub-4-nm thick polyoxides were grown on n sup + and p sup + polysilicon layers and were characterized. These oxides had larger breakdown fields, smaller electron trapping characteristics, and larger Q sub B sub D values than those of thermal polyoxides. The electron trapping characteristics of ECR N sub 2 O plasma polyoxides, which were smaller than those of thermal polyoxides at positive bias, resulted from the smaller roughness of the polysilicon surface after the oxidation process. Under a negative constant-current stress of 20 mA/cm sup 2 for polyoxide on p sup + polysilicon were obtained. These ultrathin plasma polyoxides would be good candidates for future inter-poly dielectrics and gate oxides for thin film transistors.

  14. Room temperature plasma oxidation: A new process for preparation of ultrathin layers of silicon oxide, and high dielectric constant materials

    Energy Technology Data Exchange (ETDEWEB)

    Tinoco, J.C. [Seccion de Electronica del Estado Solido, Depto. Ingenieria Electrica, CINVESTAV-IPN, Av. IPN, No. 2508, CP 07730, Mexico D.F. (Mexico) and Facultad de Ingenieria y Arquitectura, Universidad de San Martin de Porres (FIA-USMP), Av. La Fontana 1250, La Molina, Lima 12 (Peru)]. E-mail: jcesartinoco@yahoo.com.mx; Estrada, M. [Seccion de Electronica del Estado Solido, Depto. Ingenieria Electrica, CINVESTAV-IPN, Av. IPN, No. 2508, CP 07730, Mexico D.F. (Mexico)]. E-mail: mestrada@mail.cinvestav.mx; Baez, H. [Seccion de Electronica del Estado Solido, Depto. Ingenieria Electrica, CINVESTAV-IPN, Av. IPN, No. 2508, CP 07730, Mexico D.F. (Mexico); Cerdeira, A. [Seccion de Electronica del Estado Solido, Depto. Ingenieria Electrica, CINVESTAV-IPN, Av. IPN, No. 2508, CP 07730, Mexico D.F. (Mexico)

    2006-02-21

    In this paper we present basic features and oxidation law of the room temperature plasma oxidation (RTPO), as a new process for preparation of less than 2 nm thick layers of SiO{sub 2}, and high-k layers of TiO{sub 2}. We show that oxidation rate follows a potential law dependence on oxidation time. The proportionality constant is function of pressure, plasma power, reagent gas and plasma density, while the exponent depends only on the reactive gas. These parameters are related to the physical phenomena occurring inside the plasma, during oxidation. Metal-Oxide-Semiconductor (MOS) capacitors fabricated with these layers are characterized by capacitance-voltage, current-voltage and current-voltage-temperature measurements. Less than 2.5 nm SiO{sub 2} layers with surface roughness similar to thermal oxide films, surface state density below 3 x 10{sup 11} cm{sup -2} and current density in the expected range for each corresponding thickness, were obtained by RTPO in a parallel-plate reactor, at 180 mW/cm{sup 2} and pressure range between 9.33 and 66.5 Pa (0.07 and 0.5 Torr) using O{sub 2} and N{sub 2}O as reactive gases. MOS capacitors with TiO{sub 2} layers formed by RTPO of sputtered Ti layers are also characterized. Finally, MOS capacitors with stacked layers of TiO{sub 2} over SiO{sub 2}, both layers obtained by RTPO, were prepared and evaluated to determine the feasibility of the use of TiO{sub 2} as a candidate for next technology nodes.

  15. Lipid components and oxidative status of selected specialty oils

    Directory of Open Access Journals (Sweden)

    P. Madawala, S. R.

    2012-06-01

    Full Text Available Many vegetable oils are marketed as specialty oils because of their retained flavors, tastes and distinct characteristics. Specialty oil samples which were commercially produced and retailed were purchased from local superstores in Reading, UK, and Uppsala, Sweden and profiled for detailed lipid composition and oxidative status. These oil samples include: almond, hazelnut, walnut, macadamia nut, argan, avocado, grape seed, roasted sesame, rice bran, cold pressed, organic and cold pressed, warm pressed and refined rapeseed oils. The levels of PV were quite low (0.5-1.3mEq O₂/kg but AV and Rancimat values at 100 °C (except for rapeseed oils varied considerably at (0.5-15.5 and (4.2-37.0 h respectively. Macadamia nut oil was found to be the most stable oil followed by argan oil, while walnut oil was the least stable. Among the specialty oils, macadamia nut oil had the lowest (4% and walnut oil had the highest (71% level of total PUFA. The organic cold pressed rapeseed oil had considerably lower PUFA (27% compared with other rapeseed oils (28- 35%. In all the samples, α- and γ- tocopherols were the major tocopherols; nut oils had generally lower levels. Total sterols ranged from 889 to 15,106 μg/g oil. The major sterols were β-sitosterol (61-85% and campesterol (6-20%. Argan oil contained schottenol (35% and spinasterol (32%. Compared with literature values, no marked differences were observed among the differently processed, organically grown or cold pressed rapeseed oils and other specialty oils in this study.

    Muchos aceites vegetales se venden como aceites especiales debido a su flavor, gusto y características distintas. Muestras de aceites especiales de almendra, avellana, nuez, nuez de macadamia, argán, aguacate, semillas de uva, de sésamo tostadas, salvado de arroz, y aceites orgánico de semillas de colza prensado en frío y, prensado caliente, y refinados que se producen y comercializan al por menor, se obtuvieron en

  16. Determining oxidant and antioxidant status in patients with genital warts.

    Science.gov (United States)

    Cokluk, Erdem; Sekeroglu, Mehmet Ramazan; Aslan, Mehmet; Balahoroglu, Ragip; Bilgili, Serap Gunes; Huyut, Zubeyir

    2015-09-01

    Warts are abnormal skin growths caused by human papilloma virus (HPV) infections within the skin of patients. Genital warts usually appear in the perianal and perigenital regions. Asymptomatic warts may be activated after years and may damage natural immunity. The inflammation that occurs during this process may lead to an imbalance between the prooxidant and the antioxidant systems. The aim of this study was to investigate erythrocyte glutathione peroxidase (GSH-Px) activity, serum paraoxonase enzyme levels, and oxidative stress levels in patients with genital warts. In total, 32 patients with genital warts and 35 healthy subjects were included in this study. Erythrocyte GSH-Px activity, serum catalase activity, and paraoxonase enzyme, and malondialdehyde (MDA) levels were determined. Erythrocyte GSH-Px activity, serum MDA levels, and catalase activity were significantly higher in patients with genital warts than in controls (P 0.05). Serum triglyceride levels were significantly lower in patients with genital warts than in controls (P 0.05). Our data suggest that oxidative stress is increased in genital warts. Increased oxidative stress levels may contribute to the pathogenesis of genital warts, and prolonged HPV infection due to chronic inflammation could also affect oxidative stress.

  17. Markers of oxidative/nitrative damage of plasma proteins correlated with EDSS and BDI scores in patients with secondary progressive multiple sclerosis.

    Science.gov (United States)

    Morel, Agnieszka; Bijak, Michał; Niwald, Marta; Miller, Elżbieta; Saluk, Joanna

    2017-05-19

    Objectives The objective of the present study was to evaluate oxidative/nitrative stress in the plasma of 50 patients suffering from the secondary progressive course of multiple sclerosis (MS), and to verify its correlation with physical and mental disability as assessed by the Expanded Disability Status Scale (EDSS), and the Beck Depression Inventory (BDI). Methods Oxidative and nitrative damage to proteins was determined by the level of carbonyl groups and 3-nitrotyrosine using ELISA test. Based on the reaction with Ellman's reagent, we estimated the concentration of oxidized thiol groups. Additionally, we measured the level of lipid peroxidation. Results In plasma drawn from MS patients, we observed a significantly higher level of 3-NT (92%; P EDSS and BDI. Negative correlations were observed between concentration of -SH groups and EDSS and BDI. Conclusion Our results indicate that impaired red-ox balance can significantly promote neurodegeneration in secondary progressive MS.

  18. Effect of chronic periodontitis on oxidative status in patients with rheumatoid arthritis.

    Science.gov (United States)

    Sezer, Ufuk; Erciyas, Kamile; Ustün, Kemal; Pehlivan, Yavuz; Şenyurt, Süleyman Ziya; Aksoy, Nurten; Tarakçıoğlu, Mehmet; Taysı, Seyithan; Onat, Ahmet Mesut

    2013-06-01

    Rheumatoid arthritis (RA) and chronic periodontitis (CP) are the most common chronic inflammatory diseases and have remarkable similar pathologies. The aim of this study is to investigate the impact of periodontal status on oxidative stress in patients with RA by evaluating serum oxidative parameters and prolidase levels. For this cross-sectional comparative study, the following four groups were composed of 20 individuals each (80 individuals total): 1) RA with CP (RA-CP group); 2) RA but periodontally healthy (RA-C group); 3) systemically healthy with CP (CP group); and 4) systemically and periodontally healthy (C group). Demographic, periodontal, rheumatological, and serum oxidative parameters as determined by serum total antioxidant status, total oxidant status, oxidative stress index (OSI), lipid hydroperoxide levels, paraoxonase, arylesterase, and ceruloplasmin activity, prolidase level, and total sulfhydryl groups were evaluated. The OSI values of the RA-CP group were statistically significantly higher than those of the C group (P <0.05). The prolidase levels of the RA-C, RA-CP groups and the CP group were statistically higher than those of the C group (P = 0.001, P = 0.007, and P = 0.001, respectively). Although CP and RA each increase oxidative stress, in a small sample size these effects are only significant when both CP and RA are combined relative to neither exposure. In addition, increased prolidase levels in patients with RA and CP may be related to increased oxidative tissue damage.

  19. Effect of oxygen plasma and thermal oxidation on shallow nitrogen-vacancy centers in diamond

    Energy Technology Data Exchange (ETDEWEB)

    Kim, M.; Rugar, D., E-mail: rugar@us.ibm.com [IBM Research Division, Almaden Research Center, San Jose, California 95120 (United States); Center for Probing the Nanoscale, Stanford University, Stanford, California 94305 (United States); Mamin, H. J.; Sherwood, M. H.; Rettner, C. T.; Frommer, J. [IBM Research Division, Almaden Research Center, San Jose, California 95120 (United States)

    2014-07-28

    We investigate the effect of two different surface treatments on shallow nitrogen-vacancy (NV) centers in diamond. Short duration oxygen plasma exposure is found to damage near-surface NV centers, resulting in their disappearance in fluorescence images. Subsequent annealing creates large numbers of new NV centers, attributed to plasma-induced vacancy creation. By tracking individual NV centers during thermal oxidation, we show that oxidation at 550 °C results in modest improvement of spin coherence. Higher temperature oxidations correlate with gradual decline in spin coherence and eventual instability of NV centers before ultimate disappearance. This is indicative of a reduction of the NV-to-surface distance due to oxidative etching. Thermal oxidation can offer controlled access to near-surface NV spins at the nanometer scale, an important requirement for many applications of NV-based nanomagnetometry.

  20. Evidence of Higher Oxidative Status in Depression and Anxiety

    Directory of Open Access Journals (Sweden)

    G. Grases

    2014-01-01

    Full Text Available We use a simple method for evaluating antioxidative status, by measuring the redox potential of urine, and correlate the findings with measures of anxiety and depression. We include 63 individuals (28 males and 35 females aged between 20 and 65 years. The validated anxiety State-Trait Anxiety Inventory questionnaire and the validated BDI (Beck Depression Inventory questionnaire were used to evaluate anxiety and depression. Antioxidative status was determined by measuring the redox potential of urine collected in standard conditions. Correlation of the antioxidant capacity of urines evaluated using the ferric ion/specific dye method or through redox potential using the platinum electrode demonstrated the suitability of this last procedure. We found that normal anxiety state values corresponded to low urine redox potentials, whereas higher anxiety states were associated with high urinary redox potential. We also found that individuals with normal BDI values had significantly lower urine redox potentials than individuals with higher BDI values.

  1. How plasma induced oxidation, oxygenation, and de-oxygenation influences viability of skin cells

    Science.gov (United States)

    Oh, Jun-Seok; Strudwick, Xanthe; Short, Robert D.; Ogawa, Kotaro; Hatta, Akimitsu; Furuta, Hiroshi; Gaur, Nishtha; Hong, Sung-Ha; Cowin, Allison J.; Fukuhara, Hideo; Inoue, Keiji; Ito, Masafumi; Charles, Christine; Boswell, Roderick W.; Bradley, James W.; Graves, David B.; Szili, Endre J.

    2016-11-01

    The effect of oxidation, oxygenation, and de-oxygenation arising from He gas jet and He plasma jet treatments on the viability of skin cells cultured in vitro has been investigated. He gas jet treatment de-oxygenated cell culture medium in a process referred to as "sparging." He plasma jet treatments oxidized, as well as oxygenated or de-oxygenated cell culture medium depending on the dissolved oxygen concentration at the time of treatment. He gas and plasma jets were shown to have beneficial or deleterious effects on skin cells depending on the concentration of dissolved oxygen and other oxidative molecules at the time of treatment. Different combinations of treatments with He gas and plasma jets can be used to modulate the concentrations of dissolved oxygen and other oxidative molecules to influence cell viability. This study highlights the importance of a priori knowledge of the concentration of dissolved oxygen at the time of plasma jet treatment, given the potential for significant impact on the biological or medical outcome. Monitoring and controlling the dynamic changes in dissolved oxygen is essential in order to develop effective strategies for the use of cold atmospheric plasma jets in biology and medicine.

  2. Cytokines and Oxidative Stress Status Following a Handball Game in Elite Male Players

    Directory of Open Access Journals (Sweden)

    Douglas Popp Marin

    2011-01-01

    Full Text Available Background. Handball is considered an intermittent sport that places an important stress on a player's aerobic and anaerobic metabolism. However, the oxidative stress responses following a handball game remain unknown. We investigated the responses of plasma and erythrocyte antioxidant system and oxidative stress biomarkers following a single handball game. Methods. Fourteen male elite Brazilian handball athletes were recruited in the present study. Blood samples were taken before, immediately, and 24 hours after the game. Results. After the game and during 24 hours of recovery, the concentration of all oxidative stress indices changed significantly in a way indicating increased oxidative stress in the blood (thiol groups and reduced glutathione decreased, whereas TBARS and plasma antioxidant capacity was increased as well as in erythrocyte (increased levels of TBARS and protein carbonyls. Erythrocyte antioxidant enzyme activities were also significantly changed by handball. Muscle damage indices (creatine kinase and lactate dehydrogenase increased significantly after exercise. In addition, IL-6 increased after the game, whereas TNF-α decreased during recovery. Conclusion. This study demonstrates that a single handball game in elite athletes induces a marked state of oxidative stress evidenced by the oxidative modification in plasma and erythrocyte macromolecules, as well as by changes in the enzymatic and nonenzymatic antioxidant system.

  3. The influence of maternal smoking habits before pregnancy and antioxidative supplementation during pregnancy on oxidative stress status in a non-complicated pregnancy.

    Science.gov (United States)

    Ardalić, Daniela; Stefanović, Aleksandra; Kotur-Stevuljević, Jelena; Vujović, Ana; Spasić, Slavica; Spasojević-Kaliomanvska, Vesna; Jelić-Ivanović, Zorana; Mandić-Marković, Vesna; Miković, Zeljko; Cerović, Nikola

    2014-01-01

    As a physiological condition closely linked with increased susceptibility to oxidative stress, pregnancy can be further compromised by cigarette smoking. Inadequate nutrition and reduced intake of antioxidants can also disrupt the prooxidant/antioxidant relationship and contribute to oxidative stress. Increased oxidative stress during pregnancy may be involved in several complications of pregnancy, such as preterm labor, fetal growth restriction, preeclampsia and miscarriage. The aim of this study was to investigate the influence of maternal smoking habits before pregnancy on the parameters of oxidative stress and the antioxidative defense system, lipid profile parameters and paraoxonase-1 (PON1) activity during the third trimester of uncomplicated pregnancies. Healthy pregnant women (n = 86) were divided into non-smoking and smoking groups, and into groups taking vitamin supplements and not taking them. Oxidative damage was measured through the levels of thiobarbituric acid-reacting substances (TBARS) and plasma antioxidant status was evaluated by measuring total antioxidant capacity (TAC). TBARS concetration was significantly higher (p pregnancy is associated with increased oxidative stress. Vitamin supplementation has no effect on the oxidative stress status of healthy pregnant women.

  4. Plasma levels of oxidative stress-responsive apoptosis inducing protein (ORAIP) in rats subjected to physicochemical oxidative stresses.

    Science.gov (United States)

    Yao, Takako; Fujimura, Tsutomu; Murayama, Kimie; Seko, Yoshinori

    2016-01-01

    Oxidative stress is known to play a pivotal role in the pathogenesis of various disorders including atherosclerosis, aging and especially ischaemia/reperfusion injury. It causes cell damage that leads to apoptosis. However, the precise mechanism has been uncertain. Recently, we identified an apoptosis-inducing humoral factor in a hypoxia/reoxygenated medium of cardiac myocytes. We named this novel post-translationally modified secreted form of eukaryotic translation initiation factor 5A (eIF5A) as oxidative stress-responsive apoptosis inducing protein (ORAIP). We developed a sandwich ELISA and confirmed that myocardial ischaemia/reperfusion markedly increased plasma levels of ORAIP. To investigate whether the role of ORAIP is common to various types of oxidative stress, we measured plasma ORAIP levels in rats subjected to three physicochemical models of oxidative stress including N2/O2 inhalation, cold/warm-stress (heat shock) and blood acidification. In all three models, plasma ORAIP levels significantly increased and reached a peak level at 10-30 min after stimulation, then decreased within 60 min. The (mean±S.E.M.) plasma ORAIP levels before and after (peak) stimulation were (16.4±9.6) and (55.2±34.2) ng/ml in N2/O2 inhalation, (14.1±12.4) and (34.3±14.6) ng/ml in cold/warm-stress, and (18.9±14.3) and (134.0±67.2) ng/ml in blood acidification study. These data strongly suggest that secretion of ORAIP in response to oxidative stress is universal mechanism and plays an essential role. ORAIP will be an important novel biomarker as well as a specific therapeutic target of these oxidative stress-induced cell injuries. © 2016 The Author(s).

  5. Current status of Westinghouse tubular solid oxide fuel cell program

    Energy Technology Data Exchange (ETDEWEB)

    Parker, W.G. [Westinghouse Science and Technology Center, Pittsburgh, PA (United States)

    1996-04-01

    In the last ten years the solid oxide fuel cell (SOFC) development program at Westinghouse has evolved from a focus on basic material science to the engineering of fully integrated electric power systems. Our endurance for this cell is 5 to 10 years. To date we have successfully operated at power for over six years. For power plants it is our goal to have operated before the end of this decade a MW class power plant. Progress toward these goals is described.

  6. The association between low-grade inflammation, iron status and nucleic acid oxidation in the elderly

    DEFF Research Database (Denmark)

    Broedbaek, Kasper; Siersma, Volkert Dirk; Andersen, Jon T

    2011-01-01

    This study applied a case-control approach to investigate the association between low-grade inflammation, defined by high values within the normal range of C-reactive protein (CRP) and interleukin-6 (IL-6), and urinary markers of nucleic acid oxidation. No differences in excretion of urinary...... markers of nucleic acid oxidation between cases and controls were found and multivariable linear regression analysis showed no association between urinary markers of nucleic acid oxidation and inflammatory markers. Post-hoc multivariable linear regression analysis showed significant associations between...... nucleic acid oxidation and various iron status markers and especially a close relationship between nucleic acid oxidation and ferritin. This study shows no association between low-grade inflammation and urinary markers of nucleic acid oxidation in a population of elderly Italian people. The results...

  7. Serum paraoxonase activity, total thiols levels, and oxidative status in patients with acute brucellosis.

    Science.gov (United States)

    Esen, Ramazan; Aslan, Mehmet; Kucukoglu, Mehmet Emin; Cıkman, Aytekin; Yakan, Umit; Sunnetcioglu, Mahmut; Selek, Sahbettin

    2015-06-01

    It is well known that paraoxonase-1 (PON1) activity may decrease during the course of infection and inflammation. The aim of this study was to investigate serum PON1 activity, oxidative status, and thiols levels in patients with acute brucellosis. In addition, we investigated the PON1 phenotype in patients with acute brucellosis. Thirty patients with acute brucellosis and 35 healthy controls were enrolled. Serum paraoxonase and arylesterase activities, thiols levels, lipid hydroperoxide levels, total antioxidant capacity (TAC), total oxidant status (TOS) and oxidative stress index (OSI) were determined. Serum basal and salt-stimulated paraoxonase-arylesterase activities, TAC levels and thiols levels were significantly lower in patients with acute brucellosis than controls (for all, p brucellosis. These results indicate that lower PON1 activity is associated with oxidant-antioxidant imbalance.

  8. Oxidation Control of Atmospheric Plasma Sprayed FeAl Intermetallic Coatings Using Dry-Ice Blasting

    Science.gov (United States)

    Song, Bo; Dong, Shujuan; Coddet, Pierre; Hansz, Bernard; Grosdidier, Thierry; Liao, Hanlin; Coddet, Christian

    2013-03-01

    The performance of atmospheric plasma sprayed FeAl coatings has been remarkably limited because of oxidation and phase transformation during the high-temperature process of preparation. In the present work, FeAl intermetallic coatings were prepared by atmospheric plasma spraying combined with dry-ice blasting. The microstructure, oxidation, porosity, and surface roughness of FeAl intermetallic coatings were investigated. The results show that a denser FeAl coating with a lower content of oxide and lower degree of phase transformation can be achieved because of the cryogenic, the cleaning, and the mechanical effects of dry-ice blasting. The surface roughness value decreased, and the adhesive strength of FeAl coating increased after the application of dry-ice blasting during the atmospheric plasma spraying process. Moreover, the microhardness of the FeAl coating increased by 72%, due to the lower porosity and higher dislocation density.

  9. Influence of Moxifloxacin on Hepatic Redox Status and Plasma Biomarkers of Hepatotoxicity and Nephrotoxicity in Rat

    Directory of Open Access Journals (Sweden)

    Ayokanmi Ore

    2015-01-01

    Full Text Available Moxifloxacin is a broad spectrum fluoroquinolone antibacterial agent. We examined the hepatic redox status and plasma biomarkers of nephrotoxicity and hepatotoxicity in rat following administration of moxifloxacin (MXF. Twenty-four Wistar rats, 180–200 g, were randomized into four groups (I–IV. Animals in group I (control received 1 mL of distilled water, while animals in groups II, III, and IV received 1 mL each of MXF equivalent to 4 mg/kg b.w., 8 mg/kg b.w., and 16 mg/kg b.w., respectively. After seven days, plasma urea, bilirubin, and creatinine were significantly (P<0.05 elevated in the MXF-treated animals. Activities of alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase were significantly increased in the plasma of MXF-treated animals compared to control. Also plasma total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides increased significantly in the MXF-treated groups relative to control. Moreover, MXF triggered a significant decrease in hepatic catalase, superoxide dismutase, and glutathione-S transferase activities. Likewise, MXF caused a decrease in the hepatic levels of glutathione and vitamin C. A significant increase in hepatic MDA content was also observed in the MXF-treated animals relative to control. Overall, our data suggest that the half-therapeutic, therapeutic, and twice the therapeutic dose of MXF induced nephrotoxicity, hepatotoxicity, and altered hepatic redox balance in rats.

  10. Formation of nitrogen oxides from atmospheric electrodeless microwave plasmas in nitrogen-oxygen mixtures

    Science.gov (United States)

    Lee, Jungwun; Sun, Hojoong; Im, Seong-kyun; Soo Bak, Moon

    2017-08-01

    Electrodeless microwave plasmas were produced in nitrogen-oxygen mixtures at atmospheric pressure to investigate the formation of nitrogen oxides (NOx) from the plasma. The oxygen content in the mixtures is varied in the range of 1%-3%, and the total flowrate is varied in the range of 25-45 slpm while the microwave power is fixed at 2 kW. The rotational and vibrational temperatures of the plasma are measured based on plasma optical emission spectroscopy, and the amount of NOx is measured using a NOx analyzer far downstream from the plasma. The temperatures at the plasma region reach ˜6700 K, and little difference is observed between the rotational and vibrational temperatures as a result of fast vibrational-translational relaxation. Moreover, these temperatures are found to be independent of the flowrate. As the flowrate decreases and the oxygen content in the mixture increases, the level of NOx is increased from 1612 ppm to 9380 ppm. For detailed investigation, plasma kinetic simulations considering trans-rotational, vibrational, and electron temperatures separately are developed and conducted for the plasma region. The level of NOx from the kinetic simulations is found to be considerably smaller than that measured. As the equilibrium mole fraction of NOx is the highest at a temperature of 3120 ± 100 K, with the variation attributable to the composition of species, significant production of NOx is expected to occur at the post-plasma region when the plasma stream is quenched by mixing with the surrounding flow.

  11. Plasma selenium levels and oxidative stress biomarkers: a gene-environment interaction population-based study.

    Science.gov (United States)

    Galan-Chilet, Inmaculada; Tellez-Plaza, Maria; Guallar, Eliseo; De Marco, Griselda; Lopez-Izquierdo, Raul; Gonzalez-Manzano, Isabel; Carmen Tormos, M; Martin-Nuñez, Gracia M; Rojo-Martinez, Gemma; Saez, Guillermo T; Martín-Escudero, Juan C; Redon, Josep; Javier Chaves, F

    2014-09-01

    The role of selenium exposure in preventing chronic disease is controversial, especially in selenium-repleted populations. At high concentrations, selenium exposure may increase oxidative stress. Studies evaluating the interaction of genetic variation in genes involved in oxidative stress pathways and selenium are scarce. We evaluated the cross-sectional association of plasma selenium concentrations with oxidative stress levels, measured as oxidized to reduced glutathione ratio (GSSG/GSH), malondialdehyde (MDA), and 8-oxo-7,8-dihydroguanine (8-oxo-dG) in urine, and the interacting role of genetic variation in oxidative stress candidate genes, in a representative sample of 1445 men and women aged 18-85 years from Spain. The geometric mean of plasma selenium levels in the study sample was 84.76 µg/L. In fully adjusted models the geometric mean ratios for oxidative stress biomarker levels comparing the highest to the lowest quintiles of plasma selenium levels were 0.61 (0.50-0.76) for GSSG/GSH, 0.89 (0.79-1.00) for MDA, and 1.06 (0.96-1.18) for 8-oxo-dG. We observed nonlinear dose-responses of selenium exposure and oxidative stress biomarkers, with plasma selenium concentrations above ~110 μg/L being positively associated with 8-oxo-dG, but inversely associated with GSSG/GSH and MDA. In addition, we identified potential risk genotypes associated with increased levels of oxidative stress markers with high selenium levels. Our findings support that high selenium levels increase oxidative stress in some biological processes. More studies are needed to disentangle the complexity of selenium biology and the relevance of potential gene-selenium interactions in relation to health outcomes in human populations. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Kinetic aspects of the formation of aluminium oxide by use of a microwave-induced plasma.

    Science.gov (United States)

    Quade, A; Steffen, H; Hippler, R; Wulff, H

    2002-10-01

    The oxidation of thin aluminium layers in a microwave plasma has been investigated to determine the kinetics of oxide growth. Thin Al-coatings were oxidized by means of a variety of gas mixtures, characterized by different partial pressures of oxygen, in microwave-induced plasmas of different power. To study the whole kinetic process the Al-metal and the oxide formed were investigated by means of a combination of grazing incidence X-ray reflectometry (GIXR) and grazing incidence X-ray diffractometry (GIXRD). XPS and FTIR spectroscopy confirmed the formation of stoichiometric Al(2)O(3). The alumina formed is X-ray amorphous. Quantitative description of oxide formation was achieved indirectly by determination of the decrease in the integrated intensity of the Al(111)-peak and the total thickness of the whole coating. These values enabled calculation of kinetic data. It was found that oxide growth was a combination of two simultaneous processes - diffusion and sputter processes. The diffusion coefficient D (cm(2) s(-1)) and the sputter rate S (nm s(-1)) were determined. The effect of the composition of the gas mixture, microwave power, and concentration of activated oxygen species on the oxidation process will be discussed. For calculation of the activation energy, E(A), of this plasma-enhanced diffusion process the temperature-dependence of D was investigated.

  13. Photoinduced Charge Transfer at Metal Oxide/Oxide Interfaces Prepared with Plasma Enhanced Atomic Layer Deposition

    Science.gov (United States)

    Kaur, Manpuneet

    LiNbO3 and ZnO have shown great potential for photochemical surface reactions and specific photocatalytic processes. However, the efficiency of LiNbO3 is limited due to recombination or back reactions and ZnO exhibits a chemical instability in a liquid cell. In this dissertation, both materials were coated with precise thickness of metal oxide layers to passivate the surfaces and to enhance their photocatalytic efficiency. LiNbO 3 was coated with plasma enhanced atomic layer deposited (PEALD) ZnO and Al2O3, and molecular beam deposited TiO2 and VO2. On the other hand, PEALD ZnO and single crystal ZnO were passivated with PEALD SiO2 and Al2O3. Metal oxide/LiNbO3 heterostructures were immersed in aqueous AgNO3 solutions and illuminated with ultraviolet (UV) light to form Ag nanoparticle patterns. Alternatively, Al2O3 and SiO2/ZnO heterostructures were immersed in K3PO 4 buffer solutions and studied for photoelectrochemical reactions. A fundamental aspect of the heterostructures is the band alignment and band bending, which was deduced from in situ photoemission measurements. This research has provided insight to three aspects of the heterostructures. First, the band alignment at the interface of metal oxides/LiNbO 3, and Al2O3 or SiO2/ZnO were used to explain the possible charge transfer processes and the direction of carrier flow in the heterostructures. Second, the effect of metal oxide coatings on the LiNbO3 with different internal carrier concentrations was related to the surface photochemical reactions. Third is the surface passivation and degradation mechanism of Al2O 3 and SiO2 on ZnO was established. The heterostructures were characterized after stability tests using atomic force microscopy (AFM), scanning electron microscopy (SEM), and cross-section transmission electron microscopy (TEM). The results indicate that limited thicknesses of ZnO or TiO2 on polarity patterned LiNbO3 (PPLN) enhances the Ag+ photoinduced reduction process. ZnO seems more efficient

  14. Behavior of incorporated nitrogen in plasma-nitrided silicon oxide formed by chemical vapor deposition

    Science.gov (United States)

    Shinoda, Nao; Itokawa, Hiroshi; Fujitsuka, Ryota; Sekine, Katsuyuki; Onoue, Seiji; Tonotani, Junichi

    2016-04-01

    The behavior of nitrogen (N) atoms in plasma-nitrided silicon oxide (SiO2) formed by chemical vapor deposition (CVD) was characterized by physical analysis and from electrical properties. The changes in the chemical bonding and distribution of N in plasma-nitrided SiO2 were investigated for different subsequent processes. N-Si3, N-Si2O, and N2 are formed in a SiO2 film by plasma nitridation. N2 molecules diffuse out during annealing at temperatures higher than 900 °C. NH species are generated from N2 molecules and H in the SiO2 film with subsequent oxide deposition using O3 as an oxidant. The capacitance-voltage (C-V) curves of metal-oxide-semiconductor (MOS) capacitors are obtained. The negative shift of the C-V curve is caused by the increase in the density of positive fix charge traps in CVD-SiO2 induced by plasma nitridation. The C-V curve of plasma-nitrided SiO2 subjected to annealing shifts to the positive direction and that subjected to the subsequent oxide deposition shifts markedly to the negative direction. It is clarified that the density of positive charge fixed traps in plasma-nitrided SiO2 films decrease because the amount of N2 molecules is decreased by annealing, and that the density of traps increases because NH species are generated and move to the interface between SiO2 and the Si substrate with the subsequent oxide deposition.

  15. Oxidative stress and antioxidant status in cervical cancer patients.

    Science.gov (United States)

    Naidu, M Smita K; Suryakar, A N; Swami, Sanjay C; Katkam, R V; Kumbar, K M

    2007-09-01

    Cervical cancer (CaCx) is a global public health problem as it is the second most common cancer leading to the death of women worldwide. Many references revealed that the low levels of antioxidants induce the generation of free radicals leading to DNA damage and further mutations. In the present study attempt have been made to evaluate the levels of serum Lipid peroxide, Nitric Oxide (NO(.)) Erythrocytic-Superoxide Dismutase (RBC-SOD), Vitamin-C, serum Copper (Cu) and serum Zinc (Zn). 120 patients were divided in 4 groups according to the increasing CaCx stages i.e. stage I, II, III & IV respectively. All the patients were around the age group of 25-65 years. 30 healthy women between the same age group were treated as controls. Highly significant increased values of MDA, NO(.) and Cu were observed (p<0.001) whereas the activity of RBC-SOD, levels of Vitamin-C and Zn were significantly decreased in CaCx patients as compared with healthy controls (p<0.001). Cu/Zn ratio was found to be altered in CaCx patients. From our findings it can be concluded that the oxidative stress is induced among CaCx patients, which inturn increases the risk of CaCx.

  16. Influence of Echinacea extract pre- or postnatal supplementation on immune and oxidative status of growing rabbits

    Directory of Open Access Journals (Sweden)

    Salem M.A. Salem

    2010-09-01

    Full Text Available Our study aimed to investigate the effect of Echinacea purpurea (E root extract supplementation on the immune response and antioxidant status of growing New Zealand White rabbits. The study started with twenty pregnant does divided into two groups (10 each: the control (MC group and the E-treated (MT group. Twenty pups obtained from both the MC and MT does were divided into four sub-groups (n=10 each: (i PCMC (control pups from control mothers, (ii PTMC (E-treated pups from control mothers, (iii PCMT (control pups from E-treated mothers, and (iv PTMT (E-treated pups from E-treated mothers. Treatment with Echinacea showed, at the end of the fattening period, as compared to the control, a reduction in the mortality rate in the PTMC and PTMT groups and significantly increased body weight and red blood cells; the percentage of packed cell volume increased significantly in the PTMT group at the end of the experiment as compared to the PCMC group. The white blood cell count and particularly the percentage of lymphocytes increased (P<0.05 in the PTMC and PTMT groups while the percentage of neutrophils decreased (P<0.05. Plasma total protein (TP, serum total IgG, serum glutathione and nitric oxide increased (P<0.05 while the serum albumin/globulin ratio and malondialdehyde (MDA decreased (P<0.05 in the PTMC and PTMT groups. Our results suggest that Echinacea purpurea extract supplementation to pregnant and weaned rabbits might enhance the immune function and increase the activities of the antioxidant defence system in addition to the reduction of mortality rate after weaning, which is a strategy to improve growth performance and animal health when fattening rabbits for production.

  17. Surface reaction mechanisms during ozone and oxygen plasma assisted atomic layer deposition of aluminum oxide.

    Science.gov (United States)

    Rai, Vikrant R; Vandalon, Vincent; Agarwal, Sumit

    2010-09-07

    We have elucidated the reaction mechanism and the role of the reactive intermediates in the atomic layer deposition (ALD) of aluminum oxide from trimethyl aluminum in conjunction with O(3) and an O(2) plasma. In situ attenuated total reflection Fourier transform infrared spectroscopy data show that both -OH groups and carbonates are formed on the surface during the oxidation cycle. These carbonates, once formed on the surface, are stable to prolonged O(3) exposure in the same cycle. However, in the case of plasma-assisted ALD, the carbonates decompose upon prolonged O(2) plasma exposure via a series reaction kinetics of the type, A (CH(3)) --> B (carbonates) --> C (Al(2)O(3)). The ratio of -OH groups to carbonates on the surface strongly depends on the oxidizing agent, and also the duration of the oxidation cycle in plasma-assisted ALD. However, in both O(3) and O(2) plasma cycles, carbonates are a small fraction of the total number of reactive sites compared to the hydroxyl groups.

  18. Oxidation of limonene using activated carbon modified in dielectric barrier discharge plasma

    Science.gov (United States)

    Glonek, Karolina; Wróblewska, Agnieszka; Makuch, Edyta; Ulejczyk, Bogdan; Krawczyk, Krzysztof; Wróbel, Rafał. J.; Koren, Zvi C.; Michalkiewicz, Beata

    2017-10-01

    The waste from industrial fruits processing is utilized for the extraction of limonene, a renewable terpene biomass compound obtained from orange peels. This was followed by limonene oxidation, which produces highly useful oxygenated derivatives (carveol, and perillyl alcohol, 1,2-epoxylimonene and its diol). New catalysts were obtained by treating relatively inexpensive commercially available EuroPh and FPV activated carbons with plasma. These catalysts were characterized by the following instrumental methods XRD, sorption of N2 and CO2, SEM, EDS, TEM, XPS, and Raman spectroscopy. The activities of the plasma-treated catalysts were measured in the oxidation of limonene by means of either hydrogen peroxide or t-butyl hydroperoxide as the oxidizing agents. During the oxidation with hydrogen peroxide the new plasma-treated catalysts were more active than their untreated counterparts. This effect was noticeable in the considerable increase in the conversion of limonene. The mechanism explaining this property is proposed, and it takes into account the role of the appropriate functional groups on the surface of the catalysts. This work has shown for the first time that the commercial EuroPh and FPV activated carbons, after having been treated by plasma, are active catalysts for the selective limonene oxidation for the production of value-added industrial products.

  19. Red wine prevents the postprandial increase in plasma cholesterol oxidation products: a pilot study.

    Science.gov (United States)

    Natella, F; Macone, A; Ramberti, A; Forte, M; Mattivi, F; Matarese, R M; Scaccini, C

    2011-06-28

    Moderate wine consumption has been shown to lower cardiovascular risk. One of the mechanisms could involve the control of postprandial hyperlipaemia, a well-defined risk factor for atherosclerosis, reasonably by reducing the absorption of lipid oxidised species from the meal. The objective of the present study was to investigate whether wine consumption with the meal is able to reduce the postprandial increase in plasma lipid hydroperoxides and cholesterol oxidation products, in human subjects. In two different study sessions, twelve healthy volunteers consumed the same test meal rich in oxidised and oxidisable lipids (a double cheeseburger), with 300 ml of water (control) or with 300 ml of red wine (wine). The postprandial plasma concentration of cholesterol oxidation products was measured by GC-MS. The control meal induced a significant increase in the plasma concentration of lipid hydroperoxides and of two cholesterol oxidation products, 7-β-hydroxycholesterol and 7-ketocholesterol. The postprandial increase in lipid hydroperoxides and cholesterol oxidation products was fully prevented by wine when consumed with the meal. In conclusion, the present study provides evidence that consumption of wine with the meal could prevent the postprandial increase in plasma cholesterol oxidation products.

  20. The effect of antioxidant supplementation on hepatitis C viral load, transaminases and oxidative status: a randomized trial among chronic hepatitis C virus-infected patients

    DEFF Research Database (Denmark)

    Groenbaek, K.; Friis, H.; Hansen, Max

    2006-01-01

    Objective To assess the effect of antioxidant supplementation on hepatitis C viral load, transaminases and oxidative status. Methods We performed a randomized, placebo-controlled, double-blind trial to assess the effect of antioxidant supplementation on serum alanine aminotransferase, plasma...... hepatitis C viral load as well as oxidative and antioxidant markers in patients with hepatitis C virus infection. The participants received a daily dose of ascorbic acid (500 mg), D-alpha-tocopherol (9451 U) and selenium (200 mu g) or placebo tablets for 6 months. Results Twenty-three patients were included...... aminotransferase and logo-transformed plasma hepatitis C virus-RNA between the groups or changes from the baseline at any time. No consistent differences between groups or changes from the baseline with respect to erythrocyte activities of antioxidative enzymes (glutathione reductase, superoxide dismutase...

  1. Effects of physical activity on systemic oxidative/DNA status in breast cancer survivors

    Science.gov (United States)

    Tomasello, Barbara; Malfa, Giuseppe Antonio; Strazzanti, Angela; Gangi, Santi; Di Giacomo, Claudia; Basile, Francesco; Renis, Marcella

    2017-01-01

    Physical activity offers a paradoxical hormetic effect and a health benefit to cancer survivors; however, the biochemical mechanisms have not been entirely elucidated. Despite the well-documented evidence implicating oxidative stress in breast cancer, the association between health benefits and redox status has not been investigated in survivors who participate in dragon boating. The present study investigated the plasmatic systemic oxidative status (SOS) in breast cancer survivors involved in two distinct physical training exercises. A total of 75 breast cancer survivors were allocated to one of three groups: Control (resting), dragon boat racing and walking group; the latter is a type of aerobic conditioning exercise often advised to cancer patients. Various biochemical oxidative stress markers were examined, including oxidant status (hydroperoxide levels, lipid oxidation) and antioxidant status (enzymatic activities of superoxide dismutase and glutathione peroxidase, reduced glutathione levels and antioxidant capability). In addition, the individual DNA fragmentation and DNA repair capability of nucleotide excision repair (NER) systems were examined by comet assays. According to the results, all patients exhibited high levels of oxidative stress. Physical activity maintained this oxidative stress condition but simultaneously had a positive influence on the antioxidant component of the SOS, particularly in the dragon boat racing group. DNA fragmentation, according to the levels of single- and double-strand breaks, were within the normal range in the two survivor groups that were involved in training activities. Radiation-induced damage was not completely recognised or repaired by NER systems in any of the patients, probably leading to radiosensitivity and/or susceptibility of patients to cancer. These findings suggest that physical activity, particularly dragon boat racing, that modulates SOS and DNA repair capability could represent a strategy for enhancing the

  2. Liquid Phase Plasma Synthesis of Iron Oxide/Carbon Composite as Dielectric Material for Capacitor

    Directory of Open Access Journals (Sweden)

    Heon Lee

    2014-01-01

    Full Text Available Iron oxide/carbon composite was synthesized using a liquid phase plasma process to be used as the electrode of supercapacitor. Spherical iron oxide nanoparticles with the size of 5~10 nm were dispersed uniformly on carbon powder surface. The specific capacitance of the composite increased with increasing quantity of iron oxide precipitate on the carbon powder up to a certain quantity. When the quantity of the iron oxide precipitate exceeds the threshold, however, the specific capacitance was rather reduced by the addition of precipitate. The iron oxide/carbon composite containing an optimum quantity (0.33 atomic % of iron oxide precipitate exhibited the smallest resistance and the largest initial resistance slope.

  3. Evaluating Oxidative Stress Factors Induced by Chlorpyrifos Poisoning in Plasma of Wistar Rat

    OpenAIRE

    Saberi, M.; A Zare’i Mahmoudabadi; M Fasihi Ramandi; A Kazemi; J Rasouli Vani

    2014-01-01

    Introduction: Chlorpyrifos (CPF) is a broad-spectrum organophosphorus insecticide that has been used abundantly over the globe during the past 40 years. Chemical pesticides may induce oxidative stress via generating free radicals and altering antioxidant levels of the free radical scavenging enzyme activity. Therefore, this study aimed to evaluate the toxicity of Chlorpyrifos-induced oxidative stress in the plasma samples of Wistar rat. Methods: Twenty-four male Wistar rats were selected r...

  4. Solid oxide fuel cell electrolytes produced via very low pressure suspension plasma spray and electrophoretic deposition

    OpenAIRE

    Fleetwood, James D

    2014-01-01

    Solid oxide fuel cells (SOFCs) are a promising element of comprehensive energy policies due to their direct mechanism for converting the oxidization of fuel, such as hydrogen, into electrical energy. Both very low pressure plasma spray and electrophoretic deposition allow working with high melting temperature SOFC suspension based feedstock on complex surfaces, such as in non-planar SOFC designs. Dense, thin electrolytes of ideal composition for SOFCs can be fabricated with each of these proc...

  5. Zinc oxide and silver nanoparticles influence the antioxidative status in a higher aquatic plant, Spirodela punctata

    CSIR Research Space (South Africa)

    Thwala, Melusi

    2012-09-01

    Full Text Available , and emphasize the importance of a comprehensive evaluation of the sublethal effects on various aquatic species. T35 Zinc oxide and silver nanoparticles influence the antioxidative status in a higher aquatic plant, Spirodela punctata. M Thwala 1,2, N Musee3...

  6. Effect of vitamin E on oxidative stress ,status in small intestine of diabetic rat

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To investigate the effect of vitamin E on oxidative stress status in the small intestine of diabetic rats.METHODS: Twenty-four male Wistar rats were randomly divided into three groups: Control (C), non-treated diabetic (NTD) and vitamin E-treated diabetic (VETD)groups. The increases in lipid peroxidation, protein oxidation and superoxide dismutase (SOD) in these three groups was compared after 6 wk.RESULTS: There was no significant difference in catalase activity between NTD and control rats.Compared to NTD rats, the treatment with vitamin E significantly decreased lipid peroxidation and protein oxidation, and also increased catalase activity and SOD.CONCLUSION: The results revealed the occurrence of oxidative stress in the small intestine of diabetic rats. Vitamin E, as an antioxidant, attenuates lipid peroxidation and protein oxidation, and increases antioxidant defense mechanism.

  7. Non-thermal dielectric-barrier discharge plasma damages human keratinocytes by inducing oxidative stress

    Science.gov (United States)

    KIM, KI CHEON; PIAO, MEI JING; HEWAGE, SUSARA RUWAN KUMARA MADDUMA; HAN, XIA; KANG, KYOUNG AH; JO, JIN OH; MOK, YOUNG SUN; SHIN, JENNIFER H.; PARK, YEUNSOO; YOO, SUK JAE; HYUN, JIN WON

    2016-01-01

    The aim of this study was to identify the mechanisms through which dielectric-barrier discharge plasma damages human keratinocytes (HaCaT cells) through the induction of oxidative stress. For this purpose, the cells were exposed to surface dielectric-barrier discharge plasma in 70% oxygen and 30% argon. We noted that cell viability was decreased following exposure of the cells to plasma in a time-dependent manner, as shown by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The levels of intracellular reactive oxygen species (ROS) were determined using 2′,7′-dichlorodihydro-fluorescein diacetate and dihydroethidium was used to monitor superoxide anion production. Plasma induced the generation of ROS, including superoxide anions, hydrogen peroxide and hydroxyl radicals. N-acetyl cysteine, which is an antioxidant, prevented the decrease in cell viability caused by exposure to plasma. ROS generated by exposure to plasma resulted in damage to various cellular components, including lipid membrane peroxidation, DNA breaks and protein carbonylation, which was detected by measuring the levels of 8-isoprostane and diphenyl-1-pyrenylphosphine assay, comet assay and protein carbonyl formation. These results suggest that plasma exerts cytotoxic effects by causing oxidative stress-induced damage to cellular components. PMID:26573561

  8. Analysis of a gas-liquid film plasma reactor for organic compound oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Kevin [Department of Chemical and Biomedical Engineering, Florida State University, Tallahassee, FL 32310 (United States); Wang, Huijuan [School of Environmental and Safety Engineering, Jiangsu University, Zhenjiang 212013 (China); Locke, Bruce R., E-mail: blocke@fsu.edu [Department of Chemical and Biomedical Engineering, Florida State University, Tallahassee, FL 32310 (United States)

    2016-11-05

    Highlights: • Non-homogeneous filamentary plasma discharge formed along gas-liquid interface. • Hydrogen peroxide formed near interface favored over organic oxidation from liquid. • Post-plasma Fenton reactions lead to complete utilization of hydrogen peroxide. - Abstract: A pulsed electrical discharge plasma formed in a tubular reactor with flowing argon carrier gas and a liquid water film was analyzed using methylene blue as a liquid phase hydroxyl radical scavenger and simultaneous measurements of hydrogen peroxide formation. The effects of liquid flow rate, liquid conductivity, concentration of dye, and the addition of ferrous ion on dye decoloration and degradation were determined. Higher liquid flow rates and concentrations of dye resulted in less decoloration percentages and hydrogen peroxide formation due to initial liquid conductivity effects and lower residence times in the reactor. The highest decoloration energy yield of dye found in these studies was 5.2 g/kWh when using the higher liquid flow rate and adding the catalyst. The non-homogeneous nature of the plasma discharge favors the production of hydrogen peroxide in the plasma-liquid interface over the chemical oxidation of the organic in the bulk liquid phase and post-plasma reactions with the Fenton catalyst lead to complete utilization of the plasma-formed hydrogen peroxide.

  9. Effects of pre-competitional rapid weight loss on nutrition, vitamin status and oxidative stress in elite boxers.

    Science.gov (United States)

    Reljic, Dejan; Jost, Joachim; Dickau, Kirsten; Kinscherf, Ralf; Bonaterra, Gabriel; Friedmann-Bette, Birgit

    2015-01-01

    Dietary intake, vitamin status and oxidative stress were evaluated in 17 elite male boxers. Ten of them frequently reduced body weight rapidly before competitions (Weight Loss Group) and 7 did not practice rapid weight loss (Control Group). Food record checklists, blood samples for determination of vitamin status and plasma glutathione levels were obtained during a week of weight maintenance, a pre-competition week and a post-competition week. The average dietary intakes in both groups were 33 ± 8 kcal·kg(-1), 3.7 ± 1.1 g·kg(-1) carbohydrates, 1.5 ± 0.4 g·kg(-1) protein, 1.2 ± 0.4 g·kg(-1) fat and 2.2 ± 1.0 L water per day (excluding pre-competition week in Weight Loss Group). Energy (18 ± 7 kcal·kg(-1)), carbohydrate (2.2 ± 0.8 g·kg(-1)), protein (0.8 ± 0.4 g·kg(-1)), fat (0.6 ± 0.3 g·kg(-1)) and water (1.6 ± 0.6 L) consumption (P-values <0.001) and intakes of most vitamins (P-values < 0.05) were significantly reduced during the pre-competition week in the Weight Loss Group. In both groups, the intakes of vitamins A, E and folate were below recommended values throughout the three periods; however, blood vitamin and plasma glutathione levels did not change significantly. Our findings indicate a low-caloric and low-carbohydrate diet in elite boxers, regardless of participating in rapid weight loss or not. Apparently, the pre-competitional malnutitrition in the Weight Loss Group did not induce alterations in the vitamin and glutathione status.

  10. High temperature Oxidation of ODS alloy with zirconia dispersions synthesized using Arc Plasma Sintering

    Science.gov (United States)

    Bandriyana; Sujatno, A.; Salam, R.; Sugeng, B.; Dimyati, A.

    2017-02-01

    Microstructure formation and oxidation behaviour of the Oxide Dispersion Strengthened (ODS) steels for application as structure material in Nuclear Power Plant was investigated. A mixture composed of Fe and 12 wt. % Cr powder with addition of 0.5 and 1 wt.% ZrO2 particles was milled and isostatic pressed to form a sample coin. The coin was then consolidated in the Arc Plasma Sintering (APS) for 4 minutes. The samples were subjected to the high temperature oxidation test in the Magnetic Suspension Balance (MSB). The oxidation test was carried out at 700°C for 6 hours to evaluate the oxide growth in the early stage of it formation by extraction the mass gain curve. The Scanning Electron Microscope (SEM) imaging and X-ray Diffraction Spectroscopy (EDX) elemental mapping were performed to study the microstructure change and compositional distribution. SEM and EDX observation revealed the time dependent development of the Fe-Cr-phases during consolidation. The oxidation rate behaviour of the samples followed the parabolic rate characteristic for inward oxidation process driven by oxygen inward diffusion through the oxide scale with the maximum weight gain around of 60 g/m2. The oxidation resistance was strongly affected by the formation of the oxide protective layer on the surface. In so far, addition of zirconia particles has played no significant role to the oxidation behaviour.

  11. Evaluation of total antioxidant status, total oxidant status and oxidative stress index in patients with alopecia areata

    OpenAIRE

    Motor, Sedat; Ozturk, Sahin; Ozcan, Oguzhan; Gurpinar, Ahmet Burak; Can, Yesim; Yuksel, Rana; Yenin, Julide Zehra; Seraslan, Gamze; Ozturk, O Hasan

    2014-01-01

    Objectives: In this study, we aimed to evaluate total oxidative stress and total antioxidant capacity in serum samples from patients with Alopesia Areata (AA) in our laboratory conditions. Methods: In this study, 46 subjects with AA (26 females, 20 males) and the control subjects of 36 (20 females, 16 males) age- and sex-matched healthy volunteers from our hospital staffs were enrolled (the mean age was 23.7 ± 11.0 years). Blood samples were obtained following an overnight fasting state, and ...

  12. Oxidative stress status in elite athletes engaged in different sport disciplines.

    Science.gov (United States)

    Hadžović-Džuvo, Almira; Valjevac, Amina; Lepara, Orhan; Pjanić, Samra; Hadžimuratović, Adnan; Mekić, Amel

    2014-05-01

    Exercise training may increase production of free radicals and reactive oxygen species in different ways. The training type and intensity may influence free radicals production, which leads to differences in oxidative stress status between athletes, but the results of the previous studies are incosistent. The aim of our study was to estimate oxidative stress status in elite athletes engaged in different sport disciplines. The study included 39 male highly skilled professional competitors with international experience (2 Olympic players): 12 wrestlers, 14 soccer players and 13 basketball players in whom we determined the levels of advanced oxidation protein products (AOPP) and malondialdehyde (MDA), as markers of oxidative stress and the total antioxidative capacity (ImAnOX) using commercially available assay kits. The mean AOPP concentration was not significantly different between soccer players, wrestler and basketball players (60.0 ± 23.0 vs. 68.5 ± 30.8 and 80.72 ± 29.1 μmol/L respectively). Mean ImAnOX concentration was not different between soccer players (344.8 ± 35.6 μmol/L), wrestlers (342.5 ± 36.2 μmol/L) and basketball players (347.95 ± 31.3 μmol/L). Mean MDA concentration was significantly higher in basketball players (1912.1 ± 667.7 ng/mL) compared to soccer players (1060.1 ± 391.0 ng/mL, p=0.003). In spite of this fact, oxidative stress markers levels were increased compared to referral values provided by the manufacturer. Type of sports (soccer, wrestler or basketball) have no impact on the levels of oxidative stress markers. Elite sports engagement is a potent stimulus of oxidative stress that leads to the large recruitment of antioxidative defense. Oxidative stress status monitoring followed by appropriate use of antioxidants is recommended as a part of training regime.

  13. Oxidative stress status in elite athletes engaged in different sport disciplines

    Science.gov (United States)

    Hadžović - Džuvo, Almira; Valjevac, Amina; Lepara, Orhan; Pjanić, Samra; Hadžimuratović, Adnan; Mekić, Amel

    2014-01-01

    Exercise training may increase production of free radicals and reactive oxygen species in different ways. The training type and intensity may influence free radicals production, which leads to differences in oxidative stress status between athletes, but the results of the previous studies are incosistent. The aim of our study was to estimate oxidative stress status in elite athletes engaged in different sport disciplines. The study included 39 male highly skilled professional competitors with international experience (2 Olympic players): 12 wrestlers, 14 soccer players and 13 basketball players in whom we determined the levels of advanced oxidation protein products (AOPP) and malondialdehyde (MDA), as markers of oxidative stress and the total antioxidative capacity (ImAnOX) using commercially available assay kits. The mean AOPP concentration was not significantly different between soccer players, wrestler and basketball players (60.0±23.0 vs. 68.5±30.8 and 80.72±29.1 μmol/L respectively). Mean ImAnOX concentration was not different between soccer players (344.8±35.6 μmol/L), wrestlers (342±36.2 μmol/L) and basketball players (347.95±31.3 μmol/L). Mean MDA concentration was significantly higher in basketball players (1912.1±667.7 ng/mL) compared to soccer players (1060.1±391.0 ng/mL, p=0.003). In spite of this fact, oxidative stress markers levels were increased compared to referral values provided by the manufacturer. Type of sports (soccer, wrestler or basketball) have no impact on the levels of oxidative stress markers. Elite sports engagement is a potent stimulus of oxidative stress that leads to the large recruitment of antioxidative defense. Oxidative stress status monitoring followed by appropriate use of antioxidants is recommended as a part of training regime. PMID:24856375

  14. Associations between Vitamin B-12 Status and Oxidative Stress and Inflammation in Diabetic Vegetarians and Omnivores.

    Science.gov (United States)

    Lee, Yau-Jiunn; Wang, Ming-Yang; Lin, Mon-Chiou; Lin, Ping-Ting

    2016-02-26

    Diabetes is considered an oxidative stress and a chronic inflammatory disease. The purpose of this study was to investigate the correlations between vitamin B-12 status and oxidative stress and inflammation in diabetic vegetarians and omnivores. We enrolled 154 patients with type 2 diabetes (54 vegetarians and 100 omnivores). Levels of fasting glucose, glycohemoglobin (HbA1c), lipid profiles, oxidative stress, antioxidant enzymes activity, and inflammatory makers were measured. Diabetic vegetarians with higher levels of vitamin B-12 (>250 pmol/L) had significantly lower levels of fasting glucose, HbA1c and higher antioxidant enzyme activity (catalase) than those with lower levels of vitamin B-12 (≤ 250 pmol/L). A significant association was found between vitamin B-12 status and fasting glucose (r = -0.17, p = 0.03), HbA1c (r = -0.33, p = 0.02), oxidative stress (oxidized low density lipoprotein-cholesterol, r = -0.19, p = 0.03), and antioxidant enzyme activity (catalase, r = 0.28, p = 0.01) in the diabetic vegetarians; vitamin B-12 status was significantly correlated with inflammatory markers (interleukin-6, r = -0.33, p diabetic omnivores. As a result, we suggest that it is necessary to monitor the levels of vitamin B-12 in patients with diabetes, particularly those adhering to a vegetarian diet.

  15. Serum chemical elements and oxidative status in Alzheimer's disease, Parkinson disease and multiple sclerosis.

    Science.gov (United States)

    Alimonti, Alessandro; Ristori, Giovanni; Giubilei, Franco; Stazi, Maria Antonia; Pino, Anna; Visconti, Andrea; Brescianini, Sonia; Sepe Monti, Micaela; Forte, Giovanni; Stanzione, Paolo; Bocca, Beatrice; Bomboi, Giuseppe; D'Ippolito, Cristina; Annibali, Viviana; Salvetti, Marco; Sancesario, Giuseppe

    2007-05-01

    The role of some chemical elements in neurodegeneration was suggested by various authors. To obtain a profile of chemical elements and oxidative status in complex neurological diseases, an unbiased "omics" approach, i.e., quantification of 26 elements and oxidative stress parameters (serum oxidative status (SOS) and serum anti-oxidant capacity (SAC)), combined with multivariate statistical procedures (forward discriminant analysis, FDA) to analyse the vast amount of data, was applied to four groups of subjects (53 patients with Alzheimer's disease (AD), 71 with Parkinson disease (PD), 60 with multiple sclerosis (MS) and 124 healthy individuals). Descriptive statistics revealed numerous differences between each disease and healthy status. A concordant imbalance (reduction in Fe, Zn and SAC, and increase in SOS) was shared by AD, PD and MS. The FDA yielded three significant discriminant functions based on age, SOS, Ca, Fe, Si, Sn, V, Zn and Zr, and identified disease-specific profiles of element imbalances, thus showing the appropriateness of the "omics" approach. It may help assess the contribution of chemical elements and oxidative stress to disease causation and may provide complex predictors of disease evolution or treatment response.

  16. Oxidative stress status and placental implications in diabetic rats undergoing swimming exercise after embryonic implantation.

    Science.gov (United States)

    Volpato, Gustavo Tadeu; Damasceno, Débora Cristina; Sinzato, Yuri Karen; Ribeiro, Viviane Maria; Rudge, Marilza Vieira Cunha; Calderon, Iracema Mattos Paranhos

    2015-05-01

    The potential benefits and risks of physical exercise on fetal development during pregnancy remain unclear. The aim was to analyze maternal oxidative stress status and the placental morphometry to relate to intrauterine growth restriction (IUGR) from diabetic female rats submitted to swimming program after embryonic implantation. Pregnant Wistar rats were distributed into 4 groups (11 animals/group): control-nondiabetic sedentary rats, control exercised-nondiabetic exercised rats, diabetic-diabetic sedentary rats, and diabetic exercised-diabetic exercised rats. A swimming program was used as an exercise model. At the end of pregnancy, the maternal oxidative stress status, placental morphology, and fetal weight were analyzed. The swimming program was not efficient to reduce the hyperglycemia-induced oxidative stress. This fact impaired placental development, resulting in altered blood flow and energy reserves, which contributed to a deficient exchange of nutrients and oxygen for the fetal development, leading to IUGR. © The Author(s) 2014.

  17. Serum oxidative stress status in CagA positive Helicobacter pylori infection

    Directory of Open Access Journals (Sweden)

    Zeynep Çizmeci

    2011-06-01

    Full Text Available Previous studies have suggested that CagA positive Helicobacter pylori (H.pylori infection may cause the various oxidative damages. The objective of this study was to investigate serum oxidative status in infectetion with CagA positive H.pylori strains.Materials and methods: Forty-two H.pylori CagA positive subjects and 39 H.pylori CagA negative subjects were enrolled. H.pylori infection was diagnosed by the histopathological assessment of gastric mucosa. CagA status was detected by enzyme immuno assay in a micro ELISA machine. Total antioxidant status (TAS and total oxidant status (TOS were measured autoanalyzer using commercially available kits. Serum oxidative stress index (OSI was calculated using TAS and TOS measurements.Results: The levels TAS and TOS of CagA positive subjects were found to be 1.48 ± 0.18 mmol/L, 36.88 ± 19.84 mmol/L. Those of CagA negative group were measured to be 1.43 ± 0.19 mmol/L and 38.44 ± 14.72 mmol/L respectively. The values of serum OSI were similar (25.28 ± 15.85 and 26.48 ± 10.02 in CagA positive and negative groups.Conclusions: The measurements of serum oxidative status did not show any sigficant difference between the patients infected with CagA positive and CagA negative H.pilori strains. J Clin Exp Invest 2011;2(2:202-6

  18. Plasma Retinol, Thyroid Stimulating Hormone and Zinc as Predictors of Bone Mineral Density Status

    Directory of Open Access Journals (Sweden)

    Shawkia S. A. El-Sherbeny*, Effat A. A., Afifi**, Wafaa M. A. Saleh**, Asmaa, M

    2006-12-01

    . Bone status and thyroid function support the adverse effect of hyperthyroidism upon either bone osteoporosis or osteopenia and subsequently upon fracture risk. Plasma zinc deficiency correlated negatively with BMD in adult osteoporotic men.

  19. Effects of non-surgical periodontal treatment on the L-arginine-nitric oxide pathway and oxidative status in platelets.

    Science.gov (United States)

    Siqueira, Mariana Alves de Sá; Fischer, Ricardo Guimarães; Pereira, Natália Rodrigues; Martins, Marcela Anjos; Moss, Monique Bandeira; Mendes-Ribeiro, Antônio Cláudio; Figueredo, Carlos Marcelo da Silva; Brunini, Tatiana Marlowe Cunha

    2013-06-01

    Several studies have suggested an increase of cardiovascular disease (CVD) risk on periodontitis patients. An enhancement has been demonstrated on both platelet activation and oxidative stress on periodontitis patients, which may contribute for this association. Therefore, the aim of this study was to evaluate the effects of non-surgical periodontal treatment on the l-arginine-nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) pathway and oxidative status in platelets. A total of eight periodontitis patients and eight controls were included in this study. Clinical, laboratory and experimental evaluations were performed on baseline and 90 days after periodontal treatment (except for western blot analysis). The clinical periodontal evaluation included measurements of probing pocket depth (PPD), clinical attachment loss (CAL), % of sites with plaque and % of sites with bleeding on probing. We evaluated: l-[(3)H]arginine influx; nitric oxide synthase (NOS) and arginase enzymes activity and expression; expression of guanylate cyclase and phosphodiesterase-5 enzymes; cGMP levels; platelet aggregation; oxidative status through superoxide dismutase (SOD) and catalase activities, and measurement of reactive oxygen species (ROS) levels and C-reactive protein (CRP) levels. The initial results showed an activation of both l-arginine influx and via system y (+ )L associated with reduced intraplatelet cGMP levels in periodontitis patients and increased systemic levels of CRP. After periodontal treatment, there was a significant reduction of the % of sites with PPD 4-5mm, % of sites with CAL 4-5 mm, and an enhancement in cGMP levels and SOD activity. Moreover, CRP levels were reduced after treatment. Therefore, alterations in the intraplatelet l-arginine-NO-cGMP pathway and oxidant-antioxidant balance associated with a systemic inflammatory response may lead to platelet dysfunction, which may contribute to a higher risk of CVD in periodontitis.

  20. Dietary antioxidants at supranutritional doses improve oxidative status and reduce the negative effects of heat stress in sheep.

    Science.gov (United States)

    Chauhan, S S; Celi, P; Leury, B J; Clarke, I J; Dunshea, F R

    2014-08-01

    The present study was undertaken to investigate the impact of heat (thermal) stress and dietary antioxidant supplementation on the oxidative and physiological status of sheep. Twenty-four Merino × Poll Dorset crossbred ewes were housed in 1 of 2 climatic chambers (thermoneutral or heat stress) and offered either a control (10 IU vitamin E/kg DM and 0.24 mg Se/kg DM) or high antioxidant (100 IU vitamin E/kg DM and 1.20 mg Se/kg DM) diet. The sheep were exposed to 2 thermal (temperature) treatments (thermoneutral [TN]: 18-21°C and 26-30% relative humidity; and heat stress [HS]: 28-40°C and 40-50% relative humidity) for 2 wk in a single reversal design. After 1 wk of dietary treatment, animals in 1 chamber were subjected to HS for 1 wk, with the temperature being increased to 40°C between 0900 and 1700 h and then maintained at 28°C overnight. Those sheep in the TN group were maintained at 18 to 21°C. Physiological parameters were recorded 4 times a day (0900, 1300, 1700, and 2100 h) and blood samples were collected on d 1 and 7 of heat treatment. Plasma samples and red blood cell lysates were assayed for oxidative stress biomarkers. The thermal treatments were then reversed and the above measures repeated. All measured physiological parameters were elevated (P antioxidants as indicated by a diet × temperature × time interaction (P = 0.010). There was 13% decline (P = 0.014) in feed intake of the unsupplemented animals during HS whereas the same was maintained in sheep supplemented with high doses of antioxidants. Plasma reactive oxygen metabolites concentrations were reduced (114 vs. 85 units/dL; P antioxidant potential tended to be increased (3,688 vs. 3,985 μmol/L; P = 0.070) in heat stressed sheep supplemented with antioxidants. The oxidative stress index was 30% lower (P antioxidant supplemented heat stressed sheep as compared to their unsupplemented counterparts. It was concluded that heat stress negatively affects the oxidative status of sheep along

  1. Oxidation of Inconel 625 superalloy upon treatment with oxygen or hydrogen plasma at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Vesel, Alenka; Drenik, Aleksander; Elersic, Kristina; Mozetic, Miran; Kovac, Janez [Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Gyergyek, Tomaz [University of Ljubljana, Faculty of Electrical Engineering, Trzaska 25, SI-1000 Ljubljana (Slovenia); Stockel, Jan; Varju, Jozef; Panek, Radomir [Institute of Plasma Physics, Academy of Sciences of the Czech Republic, Ze Slovankou 3, Praha 8 (Czech Republic); Balat-Pichelin, Marianne, E-mail: marianne.balat@promes.cnrs.fr [PROMES-CNRS Laboratory, 7 rue du four solaire, 66120 Font Romeu Odeillo (France)

    2014-06-01

    Initial stages of Inconel 625 superalloy (Ni{sub 60}Cr{sub 30}Mo{sub 10}Ni{sub 4}Nb{sub 1}) oxidation upon short treatment with gaseous plasma at different temperatures up to about 1600 K were studied. Samples were treated for different periods up to a minute by oxygen or hydrogen plasma created with a microwave discharge in the standing-wave mode at a pressure of 40 Pa and a power 500 W. Simultaneous heating of the samples was realized by focusing concentrated solar radiation from a 5 kW solar furnace directly onto the samples. The morphological changes upon treatment were monitored using scanning electron microscopy, compositional depth profiling was performed using Auger electron spectroscopy, while structural changes were determined by X-ray diffraction. The treatment in oxygen plasma caused formation of metal oxide clusters of three dimensional crystallites initially rich in nickel oxide with the increasing chromium oxide content as the temperature was increasing. At about 1100 K iron and niobium oxides prevailed on the surface causing a drop of the material emissivity at 5 μm. Simultaneously the NiCr{sub 2}O{sub 4} compound started growing at the interface between the oxide film and bulk alloy and the compound persisted up to temperatures close to the Inconel melting point. Intensive migration of minority alloying elements such as Fe and Ti was observed at 1600 K forming mixed surface oxides of sub-micrometer dimensions. The treatment in hydrogen plasma with small admixture of water vapor did not cause much modification unless the temperature was close to the melting point. At such conditions aluminum segregated on the surface and formed well-defined Al{sub 2}O{sub 3} crystals.

  2. Removal of carbon films by oxidation in narrow gaps: Thermo-oxidation and plasma-assisted studies

    Energy Technology Data Exchange (ETDEWEB)

    Tanarro, I., E-mail: itanarro@iem.cfmac.csic.e [Instituto de Estructura de la Materia, CSIC, C/Serrano 123, 28006 Madrid (Spain); Ferreira, J.A. [Laboratorio Nacional de Fusion, As. Euratom/Ciemat, Avda. Complutense 22, 28040 Madrid (Spain); Herrero, V.J. [Instituto de Estructura de la Materia, CSIC, C/Serrano 123, 28006 Madrid (Spain); Tabares, F.L. [Laboratorio Nacional de Fusion, As. Euratom/Ciemat, Avda. Complutense 22, 28040 Madrid (Spain); Gomez-Aleixandre, C. [Instituto de Ciencia de Materiales de Madrid, CSIC, C/Sor Juana Ines de la Cruz 3, Cantoblanco, 28049 Madrid (Spain)

    2009-06-15

    The removal of hard amorphous hydrogenated carbon (a-C:H) films from narrow gaps simulating the macro-brush structures present in controlled fusion devices has been investigated. Films with a thickness of 50-150 nm were generated through plasma-assisted chemical vapor deposition (PACVD) in glow discharges of CH{sub 4}/He on Si and stainless steel plates. The deposited plates were then arranged to form sandwich structures building narrow gaps and were subjected to erosion by exposure to O{sub 2}/He plasmas and to thermal oxidation by O{sub 2} and by a NO{sub 2}/N{sub 2} (1:1) mixture. In the plasma etching experiments, the deposited layers were only partially removed by the plasma at the side wall gap surfaces, but were efficiently removed at the bottom of the gap. In the thermo-oxidation experiments, the deposited films were effectively and homogeneously removed with oxygen at 670 K and with the NO{sub 2}/N{sub 2} mixture at T > 570 K.

  3. Nitric oxide and phytohormone interactions: current status and perspectives

    Directory of Open Access Journals (Sweden)

    Luciano eFreschi

    2013-10-01

    Full Text Available Nitric oxide (NO is currently considered a ubiquitous signal in plant systems, playing significant roles in a wide range of plant responses to environmental and endogenous cues. During the signaling events leading to these plant responses, NO frequently interacts with plant hormones and other endogenous molecules, at times originating remarkably complex signaling cascades. Accumulating evidence indicates that virtually all major classes of plant hormones may influence, at least to some degree, the endogenous levels of NO. In addition, studies conducted during the induction of diverse plant responses have demonstrated that NO may also affect biosynthesis, catabolism/conjugation, transport, perception and/or transduction of different phytohormones, such as auxins, gibberellins, cytokinins, abscisic acid, ethylene, salicylic acid, jasmonates and brassinosteroids. Although still not completely elucidated, the mechanisms underlying the interaction between NO and plant hormones have recently been investigated in a number of species and plant responses. This review specifically focuses on the current knowledge of the mechanisms implicated in NO-phytohormone interactions during the regulation of developmental and metabolic plant events. The modifications triggered by NO on the transcription of genes encoding biosynthetic/degradative enzymes as well as proteins involved in the transport and signal transduction of distinct plant hormones will be contextualized during the control of developmental, metabolic and defense responses in plants. Moreover, the direct post-translational modification of phytohormone biosynthetic enzymes and receptors through S-nitrosylation will also be discussed as a key mechanism for regulating plant physiological responses. Finally, some future perspectives toward a more complete understanding of NO-phytohormone interactions will also be presented and discussed.

  4. Plasma Niobium Surface Alloying of Pure Titanium and its Oxidation at 900 ℃

    Institute of Scientific and Technical Information of China (English)

    WANG Wen-bo; ZHONG Xu; HE Zhi-yong; WANG Zhen-xia; ZHANG Ping-ze

    2007-01-01

    A niobium-modified layer on pure titanium surface was obtained by means of double glow plasma surface alloying technique. The modified layer was uniform, continuous, compact and well adhered to the substrate. The niobium composition in the modified layer decreased gradually from the surface to the substrate. The oxidation behavior of the niobium-modified layer was investigated and compared with the untreated surface at 900 ℃ for 100 h. Characterization of the layers was performed using X-ray diffraction and scanning electron microscope, respectively. The test results show that the oxidation behavior of pure titanium was improved by niobium alloying process. Niobium has a positive influence on the oxidation resistance.

  5. Studies on non-oxide coating on carbon fibers using plasma enhanced chemical vapor deposition technique

    Science.gov (United States)

    Patel, R. H.; Sharma, S.; Prajapati, K. K.; Vyas, M. M.; Batra, N. M.

    2016-05-01

    A new way of improving the oxidative behavior of carbon fibers coated with SiC through Plasma Enhanced Chemical Vapor Deposition technique. The complete study includes coating of SiC on glass slab and Stainless steel specimen as a starting test subjects but the major focus was to increase the oxidation temperature of carbon fibers by PECVD technique. This method uses relatively lower substrate temperature and guarantees better stoichiometry than other coating methods and hence the substrate shows higher resistance towards mechanical and thermal stresses along with increase in oxidation temperature.

  6. Plasma-induced high efficient synthesis of boron doped reduced graphene oxide for supercapacitors

    DEFF Research Database (Denmark)

    Li, Shaobo; Wang, Zhaofeng; Jiang, Hanmei

    2016-01-01

    In this work, we presented a novel route to synthesize boron doped reduced graphene oxide (rGO) by using the dielectric barrier discharge (DBD) plasma technology under ambient conditions. The doping of boron (1.4 at%) led to a significant improvement in the capacitance of rGO and supercapacitors...

  7. High thermoelectric performance of reduced lanthanide molybdenum oxides densified by spark plasma sintering

    DEFF Research Database (Denmark)

    Xu, Jianxiao Jackie; Sonne, Monica; Yanangiya, Shun-ichi

    2010-01-01

    Four highly reduced molybdenum oxides LnMo8O14 (Ln = La, Ce, Nd and Sm) containing bicapped Mo8 clusters were synthesized via solid state reaction followed by spark plasma sintering. The thermoelectric properties were investigated, and NdMo8O14 exhibits the best performance with the maximum power...

  8. Impact of Seminal Chemical Elements on the Oxidative Balance in Bovine Seminal Plasma and Spermatozoa

    OpenAIRE

    Eva Tvrdá; Norbert Lukáč; Monika Schneidgenová; Jana Lukáčová; Csaba Szabó; Zofia Goc; Agnieszka Greń; Peter Massányi

    2013-01-01

    Mutual relationships between selected chemical elements (Na, K, Fe, Cu, Mg, and Zn), basic motility characteristics (motility and progressive motility), and markers of the oxidative balance (superoxide dismutase, catalase, glutathione, albumin, and malondialdehyde) were investigated in bovine seminal plasma and spermatozoa. Computer assisted sperm analysis was used to assess the motility parameters; mineral concentrations were determined by the voltammetric method and flame absorption spectro...

  9. The kinetic studies of direct methane oxidation to methanol in the plasma process

    Institute of Scientific and Technical Information of China (English)

    INDARTO Antonius; CHOI Jae-Wook; LEE Hwaung; SONG Hyung Keun

    2008-01-01

    The research outlined here includes a study of methanol production from direct methane conversion by means of thermal and plasma method. The kinetic study, derived from thermal-based approach, was carried out to investigate thoroughly the possible intermediate species likely to be presented in the process. A set of plasma experiments was undertaken by using dielectric barrier discharge (DBD), classified as non-thermal plasma, done at atmospheric pressure and room temperature. Plasma proc-ess yields more methanol than thermal process at the same methane conversion rates and methane to oxygen feed ratios. Oxidation reaction of thermal process resulted CO and CO2 as the most dominant products and the selectivity reached 19% and 68%, respectively. Moreover, more CO and less CO2 were produced in plasma process than in thermal process. The selectivity of CO and CO2 by plasma was 47% and 20%, respectively. Ethane (C2H6) was detected as the only higher hydrocarbon with a signifi-cant concentration. The concentration of ethane reached 9% of the total products in plasma process and 17% in thermal process. The maximum selectivity of methanol, the target material of this research, was 12% obtained by plasma method and less than 5% by thermal process. In some certain points, the kinetic model closely matched with the experimental results.

  10. Catalyst-Packed Non-Thermal Plasma Reactor for Removal of Nitrogen Oxides

    Science.gov (United States)

    Ravi, V.; Young, Sun Mok; Rajanikanth, B. S.; Kang, Ho-Chul

    2003-02-01

    A single-stage plasma-catalytic reactor in which catalytic materials were packed was used to remove nitrogen oxides. The packing material was scoria being made of various metal oxides including Al2O3, MgO, TiO2, etc. Scoria was able to act not only as dielectric pellets but also as a catalyst in the presence of reducing agent such as ethylene and ammonia. Without plasma discharge, scoria did not work well as a catalyst in the temperature range of 100 °C to 200 °C, showing less than 10% of NOx removal efficiency. When plasma is produced inside the reactor, the NOx removal efficiency could be increased to 60% in this temperature range.

  11. Atmospheric-pressure glow plasma synthesis of plasmonic and photoluminescent zinc oxide nanocrystals

    Science.gov (United States)

    Bilik, N.; Greenberg, B. L.; Yang, J.; Aydil, E. S.; Kortshagen, U. R.

    2016-06-01

    In this paper, we present a large-volume (non-micro) atmospheric pressure glow plasma capable of rapid, large-scale zinc oxide nanocrystal synthesis and deposition (up to 400 μg/min), whereas in the majority of the literature, nanoparticles are synthesized using micro-scale or filamentary plasmas. The reactor is an RF dielectric barrier discharge with a non-uniform gap spacing. This design encourages pre-ionization during the plasma breakdown, making the discharge uniform over a large volume. The produced zinc oxide nanocrystals typically have diameters ranging from 4 to 15 nm and exhibit photoluminescence at ≈550 nm and localized surface plasmon resonance at ≈1900 cm-1 due to oxygen vacancies. The particle size can be tuned to a degree by varying the gas temperature and the precursor mixing ratio.

  12. Atmospheric-pressure glow plasma synthesis of plasmonic and photoluminescent zinc oxide nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Bilik, N., E-mail: bilik006@umn.edu, E-mail: kortshagen@umn.edu; Greenberg, B. L.; Yang, J.; Kortshagen, U. R., E-mail: bilik006@umn.edu, E-mail: kortshagen@umn.edu [Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Aydil, E. S. [Department of Chemical Engineering, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2016-06-28

    In this paper, we present a large-volume (non-micro) atmospheric pressure glow plasma capable of rapid, large-scale zinc oxide nanocrystal synthesis and deposition (up to 400 μg/min), whereas in the majority of the literature, nanoparticles are synthesized using micro-scale or filamentary plasmas. The reactor is an RF dielectric barrier discharge with a non-uniform gap spacing. This design encourages pre-ionization during the plasma breakdown, making the discharge uniform over a large volume. The produced zinc oxide nanocrystals typically have diameters ranging from 4 to 15 nm and exhibit photoluminescence at ≈550 nm and localized surface plasmon resonance at ≈1900 cm{sup −1} due to oxygen vacancies. The particle size can be tuned to a degree by varying the gas temperature and the precursor mixing ratio.

  13. Hydrogen plasma treatment for improved conductivity in amorphous aluminum doped zinc tin oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Morales-Masis, M., E-mail: monica.moralesmasis@epfl.ch; Ding, L.; Dauzou, F. [Photovoltaics and Thin-Film Electronics Laboratory (PVLab), Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne - EPFL, Rue de la Maladière 71b, CH-2002 Neuchatel (Switzerland); Jeangros, Q. [Interdisciplinary Centre for Electron Microscopy, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne (Switzerland); Hessler-Wyser, A. [Photovoltaics and Thin-Film Electronics Laboratory (PVLab), Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne - EPFL, Rue de la Maladière 71b, CH-2002 Neuchatel (Switzerland); Interdisciplinary Centre for Electron Microscopy, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne (Switzerland); Nicolay, S. [Centre Suisse d’Electronique et de Microtechnique (CSEM) SA, Rue Jaquet-Droz 1, CH-2002 Neuchatel (Switzerland); Ballif, C. [Photovoltaics and Thin-Film Electronics Laboratory (PVLab), Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne - EPFL, Rue de la Maladière 71b, CH-2002 Neuchatel (Switzerland); Centre Suisse d’Electronique et de Microtechnique (CSEM) SA, Rue Jaquet-Droz 1, CH-2002 Neuchatel (Switzerland)

    2014-09-01

    Improving the conductivity of earth-abundant transparent conductive oxides (TCOs) remains an important challenge that will facilitate the replacement of indium-based TCOs. Here, we show that a hydrogen (H{sub 2})-plasma post-deposition treatment improves the conductivity of amorphous aluminum-doped zinc tin oxide while retaining its low optical absorption. We found that the H{sub 2}-plasma treatment performed at a substrate temperature of 50 °C reduces the resistivity of the films by 57% and increases the absorptance by only 2%. Additionally, the low substrate temperature delays the known formation of tin particles with the plasma and it allows the application of the process to temperature-sensitive substrates.

  14. Effect of pharmacological lowering of plasma urate on exercise-induced oxidative stress.

    Science.gov (United States)

    McAnulty, S R; Hosick, P A; McAnulty, L S; Quindry, J C; Still, L; Hudson, M B; Dibarnardi, A N; Milne, G L; Morrow, J D; Austin, M D

    2007-12-01

    Urate is a metabolic end product of purine metabolism that contributes about 66% of the antioxidant capacity of plasma. The objective of this study was to evaluate the importance of plasma urate as an antioxidant using pharmacological lowering and examining the impact on plasma antioxidant capacity and oxidative stress after intense exercise. Fifteen subjects ran for 45 min at approximately 80% VO2 max under the influence of probenecid (1 g/d) (PRO) or placebo (PLA) in a double-blind, crossover design. Blood samples obtained at baseline, pre-exercise, and immediately post-exercise were analyzed for F2-isoprostanes, lipid hydroperoxides (LHs), ferric-reducing ability of plasma (FRAP), urate, ascorbate (AA), and nitrite. A 2 (group)x2 (time) repeated-measures analysis of variance (ANOVA), one-way ANOVA, Tukey-Kramer multiple comparison tests, and Student's t tests were used for statistical analysis. PRO exhibited lowered urate and FRAP compared with baseline (pplasma markers of exercise-induced oxidative stress were not affected by below-normal physiological concentrations of urate and a diminished antioxidant capacity within the plasma compartment.

  15. Oxidation Behavior of Titanium Carbonitride Coating Deposited by Atmospheric Plasma Spray Synthesis

    Science.gov (United States)

    Zhu, Lin; He, Jining; Yan, Dianran; Liao, Hanlin; Zhang, Nannan

    2017-08-01

    Abstract: As a high-hardness and anti-frictional material, titanium carbonitride (TiCN) thick coatings or thin films are increasingly being used in many industrial fields. In the present study, TiCN coatings were obtained by atmospheric plasma spray synthesis or reactive plasma spray. In order to promote the reaction between the Ti particles and reactive gases, a home-made gas tunnel was mounted on a conventional plasma gun to perform the spray process. The oxidation behavior of the TiCN coatings under different temperatures in static air was carefully investigated. As a result, when the temperature was over 700 °C, the coatings suffered from serious oxidation, and finally they were entirely oxidized to the TiO2 phase at 1100 °C. The principal oxidation mechanism was clarified, indicating that the oxygen can permeate into the defects and react with TiCN at high temperatures. In addition, concerning the use of a TiCN coating in high-temperature conditions, the microhardness of the oxidized coatings at different treatment temperatures was also evaluated.

  16. Fabrication of bioactive titania coating on nitinol by plasma electrolytic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Siu, H.T.; Man, H.C., E-mail: mfhcman@polyu.edu.hk

    2013-06-01

    Surface modification was attempted on Nitinol (NiTi) by plasma electrolytic oxidation (PEO) in aqueous solutions of sodium sulphate and sodium hydroxide (Na{sub 2}SO{sub 4}-NaOH) using an AC power supply. A thick and porous oxide layer with micron-sized pores was formed on the Nitinol substrate, with the thickness of the oxide layer ranging from a few μm to over 10 μm, depending on the processing time. X-ray diffraction (XRD) analysis confirmed that the oxide formed was anatase. Potentiodynamic polarization tests in Hanks’ solution showed that the corrosion resistance of PEO-coated Nitinol was much higher than that of the substrate. More importantly, the apatite-forming ability of the PEO-treated NiTi was found to be enhanced. This could be attributed to the anatase crystalline structure of the titanium oxide and the porous structure that facilitates the anchorage of the hydroxyapatite particles.

  17. Role of dietary fish oil on nitric oxide synthase activity and oxidative status in mice red blood cells.

    Science.gov (United States)

    Martins, Marcela A; Moss, Monique B; Mendes, Iara K S; Águila, Márcia B; Mandarim-de-Lacerda, Carlos Alberto; Brunini, Tatiana M C; Mendes-Ribeiro, Antônio Cláudio

    2014-12-01

    The consumption of n-3 polyunsaturated fatty acids (PUFAs) derived from fish oil concomitant with a reduced intake of saturated fats is associated with cardiovascular benefits, which may result from the participation of nitric oxide (NO). In contrast, PUFAs are vulnerable to peroxidation, which could affect the oxidative stability of the cell and reduce NO bioavailability. Therefore, we investigated the effects of high fat diets with increasing amounts of fish oil (0-40% of energy) in place of lard on the l-arginine-NO pathway, the arginase pathway and oxidative status in mice red blood cells (RBC). We found that l-arginine transport, as well as NO synthase (NOS) expression and activity, was enhanced by the highest doses of fish oil (30 and 40%). In contrast, diets rich in lard led to NOS expression and activity impairment. Arginase expression was not significantly affected by any of the dietary regimens. No significant difference in protein and lipid oxidative markers was observed among any of the fish-oil fed mice; only lard feeding induced protein damage in addition to a decreased superoxide dismutase activity. These data suggest that a substantial dose of fish oil, but not low doses, activates the RBC l-arginine-NO pathway without resulting in oxidative damage.

  18. Plasma in-liquid method for reduction of zinc oxide in zinc nanoparticle synthesis

    Science.gov (United States)

    Amaliyah, Novriany; Mukasa, Shinobu; Nomura, Shinfuku; Toyota, Hiromichi; Kitamae, Tomohide

    2015-02-01

    Metal air-batteries with high-energy density are expected to be increasingly applied in electric vehicles. This will require a method of recycling air batteries, and reduction of metal oxide by generating plasma in liquid has been proposed as a possible method. Microwave-induced plasma is generated in ethanol as a reducing agent in which zinc oxide is dispersed. Analysis by energy-dispersive x-ray spectrometry (EDS) and x-ray diffraction (XRD) reveals the reduction of zinc oxide. According to images by transmission electron microscopy (TEM), cubic and hexagonal metallic zinc particles are formed in sizes of 30 to 200 nm. Additionally, spherical fiber flocculates approximately 180 nm in diameter are present.

  19. Characterization of Bimetallic Fe-Ru Oxide Nanoparticles Prepared by Liquid-Phase Plasma Method

    Science.gov (United States)

    Lee, Sung-Jin; Lee, Heon; Jeon, Ki-Joon; Park, Hyunwoong; Park, Young-Kwon; Jung, Sang-Chul

    2016-07-01

    The bimetallic Fe-Ru oxide nanoparticles were synthesized in the liquid-phase plasma (LPP) method which employed iron chloride and ruthenium chloride as precursors. The active species (OH·, Hα, Hβ, and OI) and the iron and ruthenium ions were observed in the plasma field created by the LPP process. The spherical-shaped bimetallic Fe-Ru oxide nanoparticles were synthesized by the LPP reaction, and the size of the particles was growing along with the progression of the LPP reaction. The synthesized bimetallic Fe-Ru oxide nanoparticles were comprised of Fe2O3, Fe3O4, RuO, and RuO2. Ruthenium had a higher reduction potential than iron and resulted in higher ruthenium composition in the synthesized bimetallic nanoparticles. The control of the molar ratio of the precursors in the reactant solution was found to be employed as a means to control the composition of the elements in bimetallic nanoparticles.

  20. Defective iron-oxide nanoparticles synthesised by high temperature plasma processing: a magnetic characterisation versus temperature

    Science.gov (United States)

    Balasubramanian, C.; Joseph, B.; Orpe, PB; Saini, NL; Mukherjee, S.; Dziedzic-Kocurek, K.; Stanek, J.; Di Gioacchino, D.; Marcelli, A.

    2016-11-01

    Magnetic properties and phase compositions of iron-oxide nanoparticles synthesised by a high temperature arc plasma route have been investigated by Mössbauer spectroscopy and high harmonic magnetic AC susceptibility measurements, and correlated with morphological and structural properties for different synthesis conditions. The Mössbauer spectra precisely determined the presence of different iron-oxide fractions in the investigated nanoparticles, while the high harmonic magnetic susceptibility measurements revealed the occurrence of metastable magnetic phases evolving in temperature and time. This study illustrates magnetic properties and dynamics of the magnetic configurations of iron-oxide nanoparticles grown by high temperature plasma, a process less explored so far but extremely useful for synthesising large numbers of nanoparticles for industrial applications.

  1. Atmospheric plasma generates oxygen atoms as oxidizing species in aqueous solutions

    Science.gov (United States)

    Mokhtar Hefny, Mohamed; Pattyn, Cedric; Lukes, Petr; Benedikt, Jan

    2016-10-01

    A remote microscale atmospheric pressure plasma jet (µAPPJ) with He, He/H2O, He/O2, and He/O2/H2O gas mixtures was used to study the transport of reactive species from the gas phase into the liquid and the following aqueous phase chemistry. The effects induced by the µAPPJ in water were quantitatively studied using phenol as a chemical probe and by measuring H2O2 concentration and pH values. These results were combined with the analysis of the absolute densities of the reactive species and the modeling of convective/diffusion transport and recombination reactions in the effluent of the plasma jet. Additionally, modified plasma jets were used to show that the role of emitted photons in aqueous chemistry is negligible for these plasma sources. The fastest phenol degradation was measured for the He/O2 plasma, followed by He/H2O, He/O2/H2O, and He plasmas. The modeled quantitative flux of O atoms into the liquid in the He/O2 plasma case was highly comparable with the phenol degradation rate and showed a very high transfer efficiency of reactive species from the plasma into the liquid, where more than half of the O atoms leaving the jet nozzle entered the liquid. The results indicate that the high oxidative effect of He/O2 plasma was primarily due to solvated O atoms, whereas OH radicals dominated the oxidative effects induced in water by plasmas with other gas mixtures. These findings help to understand, in a quantitative way, the complex interaction of cold atmospheric plasmas with aqueous solutions and will allow a better understanding of the interaction of these plasmas with water or buffered solutions containing biological macromolecules, microorganisms, or even eukaryotic cells. Additionally, the µAPPJ He/O2 plasma source seems to be an ideal tool for the generation of O atoms in aqueous solutions for any future studies of their reactivity.

  2. Influence of O2 – plasma ambience and growth temperature on the oxidation of Mo-metal and volatilization of oxides

    Directory of Open Access Journals (Sweden)

    Rabindar K. Sharma

    2013-09-01

    Full Text Available In this communication, we investigated role of the oxygen plasma on the oxidation of Mo strip surface (source of Mo and volatilization of formed oxide species. Molybdenum oxide thin films are deposited on Si substrate simultaneously by using the volatilized oxide species as vapor source. A special setup is designed to create stable discharge oxygen plasma. Both the Mo strip surface and oxide films deposited on Si substrates at different temperatures are characterized independently. The presence of well indexed and intense peaks corresponding to MoO3 and Mo8O23 oxide phases in x-ray diffraction (XRD patterns of metals strips, heated at different temperatures in oxygen plasma ambience has been considered as proof of oxidation of Mo-strip surface. The reduction in peaks intensity with increase in metal strip temperature indicates high rate of oxidation and oxide volatilization. It is observed that film formation on silicon substrate could not take place without oxygen plasma even at 500ºC. The scanning electron microscopy (SEM studies of Mo strips as well as the films deposited on Si substrates, at different temperatures are showing the modifications in surface morphology and agreed with the XRD results. Both Raman and FTIR observations of Mo strip are also in consonance with the XRD and SEM findings. The occurrence of oxidation of Mo metal and volatilization of oxide species at this low temperature 300ºC is reported for the first time.

  3. Application of a novel plasma-induced CD/MWCNT/iron oxide composite in zinc decontamination.

    Science.gov (United States)

    Yang, Shitong; Guo, Zhiqiang; Sheng, Guodong; Wang, Xiangke

    2012-10-01

    Herein, β-cyclodextrin (β-CD) was grafted onto magnetic MWCNT/iron oxide particles by using low temperature plasma-induced technique to synthesize a novel nanocomposite. The prepared composite (denoted as CD/MWCNT/iron oxide) exhibited high magnetic property (saturation magnetization M(s)=37.8 emu/g) and good dispersion property in aqueous solution. Batch experiments were conducted to evaluate the application potential of CD/MWCNT/iron oxide in the decontamination of Zn(II) from aqueous solutions. The sorption amount of Zn(II) on CD/MWCNT/iron oxide was higher than that of Zn(II) on MWCNT/iron oxides and oxidized MWCNTs, indicating that the grafted β-CD could enhance the sorption capacity of CD/MWCNT/iron oxide composite toward Zn(II) by providing multiple hydroxyl functional groups. Due to its high magnetic, CD/MWCNT/iron oxide could be easily separated from aqueous solution with an external magnetic field. Regeneration studies suggested that CD/MWCNT/iron oxide can support long term use as a cost-effective material in sewage treatment with minimum replacement costs.

  4. Effect upon biocompatibility and biocorrosion properties of plasma electrolytic oxidation in trisodium phosphate electrolytes.

    Science.gov (United States)

    Kim, Yu-Kyoung; Park, Il-Song; Lee, Kwang-Bok; Bae, Tae-Sung; Jang, Yong-Seok; Oh, Young-Min; Lee, Min-Ho

    2016-03-01

    Surface modification to improve the corrosion resistance and biocompatibility of the Mg-Al-Zn-Ca alloy was conducted via plasma electrolytic oxidation (PEO) in an electrolyte that included phosphate. Calcium phosphate can be easily induced on the surface of a PEO coating that includes phosphate in a physiological environment because Ca(2+) ions in body fluids can be combined with PO4 (3-). Cytotoxicity of the PEO coating formed in electrolytes with various amounts of Na3PO4 was identified. In particular, the effects that PEO films have upon oxidative stress and differentiation of osteoblast activity were studied. As the concentration of Na3PO4 in the electrolyte increased, the oxide layer was found to become thicker, which increased corrosion resistance. However, the PEO coating formed in electrolytes with over 0.2 M of added Na3PO4 exhibited more microcracks and larger pores than those formed in smaller Na3PO4 concentrations owing to a large spark discharge. A nonuniform oxide film that included more phosphate caused more cytotoxicity and oxidative stress, and overabundant phosphate content in the oxide layer interrupted the differentiation of osteoblasts. The corrosion resistance of the magnesium alloy and the thickness of the oxide layer were increased by the addition of Na3PO4 in the electrolyte for PEO treatment. However, excessive phosphate content in the oxide layer led to oxidative stress, which resulted in reduced cell viability and activity.

  5. Alterations in antioxidant and oxidant status of children after on-pump surgery for cyanotic and acyanotic congenital heart diseases.

    Science.gov (United States)

    Altin, Firat H; Yildirim, Hayriye A; Tanidir, Ibrahim C; Yildiz, Okan; Kahraman, Meliha Z; Ozturk, Erkut; Celebi, Sinem B; Kyaruzi, Mugisha; Bakir, İhsan

    2017-03-01

    Oxidative stress refers to an imbalance between reactive oxidative species and antioxidants. In this case-controlled, prospective, observational study, we investigated the total oxidant status, total antioxidant status, oxidative stress index, and albumin and C-reactive protein levels of children with cyanotic and acyanotic congenital heart diseases who had undergone on-pump cardiac surgery. The study groups consisted of 60 patients with congenital heart disease, who were operated under cardiopulmonary bypass, and a control group of 30 healthy individuals. The patients were classified into two groups. Among them, one was a patient group that consisted of 30 patients with acyanotic congenital heart disease and the other group consisted of 30 patients with cyanotic congenital heart disease. In the patient groups, blood samples were collected before surgery and at one and 24 hours following surgery. In control groups, blood samples were collected once during hospital admission. No statistically significant differences were found between the groups in terms of baseline total oxidant status, total antioxidant status, and oxidative stress index values. Regarding the postoperative first-hour and 24-hour total oxidant status and total antioxidant status levels as well as oxidative stress index values, there were no significant differences between the groups, except for an increase in total antioxidant status levels (p=0.002) 24 hours after surgery in cyanotic patients. There was no difference between oxidative stress status of cyanotic and acyanotic congenital heart disease patients and healthy individuals. Oxidative stress status of cyanotic and acyanotic patients does not change after cardiac surgery under cardiopulmonary bypass.

  6. The effects of exposure of {sup 60}Co on the oxidant/antioxidant status among radiation victims

    Energy Technology Data Exchange (ETDEWEB)

    Demir, Mustafa E-mail: mmdemir@e-kolay.net; Konukoglu, Dildar; Kabasakal, Levent; Yelke, Hakan Kadir; Ergen, Kadir; Ahmed, Sabbir

    2002-07-01

    This retrospective study has been performed with radiation victims who were accidentally exposed to a {sup 60}Co source and its release into the environment. The aim of the study was to assess the effects of elevated radiation exposures on plasma level, on erythrocyte thio barbituric acid reactive substance (TBARS) level and on erythrocyte glutathione (GSH) levels. Patients were treated in different hospitals with different symptoms such as nausea, vomiting, dizziness, along with severe anemia in some patients. Blood samples were collected 3-5 days following the radiation accident. Increases in plasma (6.25{+-}0.90 nmol ml{sup -1}) and erythrocyte TBARS levels (330.5{+-}30.5 {mu}mol gHb{sup -1}) were found in comparison to a healthy group (3.72{+-}0.68 nmol ml{sup -1} and 150.7{+-}20.5 {mu}mol gHb{sup -1}, respectively) at a significant level (p<0.001). Erythrocyte GSH levels (5.2{+-}0.30 {mu}mol gHb{sup -1}) were found to be decreased among the victims (healthy group: 10.2{+-}0.7 {mu}mol gHb{sup -1}) at the same significance level (p<0.001). These observations confirm a significant change induced by radiation in the oxidant/antioxidant status among the victims. It is suggested here that antioxidant supplementation therapy might be effective in preventing the harmful effects of {sup 60}Co radiation among radiation victims.

  7. Vitamin B-6 and colorectal cancer risk: a prospective population-based study using 3 distinct plasma markers of vitamin B-6 status.

    Science.gov (United States)

    Gylling, Björn; Myte, Robin; Schneede, Jörn; Hallmans, Göran; Häggström, Jenny; Johansson, Ingegerd; Ulvik, Arve; Ueland, Per M; Van Guelpen, Bethany; Palmqvist, Richard

    2017-03-08

    Background: Higher plasma concentrations of the vitamin B-6 marker pyridoxal 5'-phosphate (PLP) have been associated with reduced colorectal cancer (CRC) risk. Inflammatory processes, including vitamin B-6 catabolism, could explain such findings.Objective: We investigated 3 biomarkers of vitamin B-6 status in relation to CRC risk.Design: This was a prospective case-control study of 613 CRC cases and 1190 matched controls nested within the Northern Sweden Health and Disease Study (n = 114,679). Participants were followed from 1985 to 2009, and the median follow-up from baseline to CRC diagnosis was 8.2 y. PLP, pyridoxal, pyridoxic acid (PA), 3-hydroxykynurenine, and xanthurenic acids (XAs) were measured in plasma with the use of liquid chromatography-tandem mass spectrometry. We calculated relative and absolute risks of CRC for PLP and the ratios 3-hydroxykynurenine:XA (HK:XA), an inverse marker of functional vitamin B-6 status, and PA:(PLP + pyridoxal) (PAr), a marker of inflammation and oxidative stress and an inverse marker of vitamin B-6 status.Results: Plasma PLP concentrations were associated with a reduced CRC risk for the third compared with the first quartile and for PLP sufficiency compared with deficiency [OR: 0.60 (95% CI: 0.44, 0.81) and OR: 0.55 (95% CI: 0.37, 0.81), respectively]. HK:XA and PAr were both associated with increased CRC risk [OR: 1.48 (95% CI: 1.08, 2.02) and OR: 1.50 (95% CI: 1.10, 2.04), respectively] for the fourth compared with the first quartile. For HK:XA and PAr, the findings were mainly observed in study participants with B-6 deficiency as measured by plasma PLP is associated with a clear increase in CRC risk. Furthermore, our analyses of novel markers of functional vitamin B-6 status and vitamin B-6-associated oxidative stress and inflammation suggest a role in tumor progression rather than initiation.

  8. The Effect of White Tea on the Increment of Smokers' Oxidative Status

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    Rosyanne Kushargina

    2015-01-01

    Full Text Available Smokers are at high risk of oxidative stress. Many previous studies proved that tea is a source of antioxidants which might reduce oxidative stress. White tea is known to have the highest antioxidant capacity compared to other kinds of tea. Yet there was no sufficient evidence regarding the effect of white tea, especially against oxidative stress on smokers. This study was aimed to analyze the effect of white tea on oxidative status of smokers, using a pre-post experimental design. Nine medium smokers (11-21 cig/day aged 30-45 years were instructed to drink 200 ml white tea three times a day for 4 weeks. Total Antioxidant Capacity (TAC of blood serum was measured 3 times. The first at baseline, the second after four weeks intervention, and the third 2 weeks after intervention period. The level of TAC significantly increased from 1,17 m mol/L to 1,42 m mol/L after 4 weeks intervention (P=0.000. The increase in the TAC was only temporary, TAC significantly decreased from 1.42 m mol/L to 1.18 m mol/L 2 weeks after the intervention (P= 0.000. These results prove that drinking 200 ml of white tea 3 times a day for 4 weeks has a significant benefit on the oxidative status of smokers, although temporary. Smokers are advised to consume white tea continuously for to sustain these positive effects.

  9. Remote Plasma Oxidation and Atomic Layer Etching of MoS2.

    Science.gov (United States)

    Zhu, Hui; Qin, Xiaoye; Cheng, Lanxia; Azcatl, Angelica; Kim, Jiyoung; Wallace, Robert M

    2016-07-27

    Exfoliated molybdenum disulfide (MoS2) is shown to chemically oxidize in a layered manner upon exposure to a remote O2 plasma. X-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED), and atomic force microscopy (AFM) are employed to characterize the surface chemistry, structure, and topography of the oxidation process and indicate that the oxidation mainly occurs on the topmost layer without altering the chemical composition of underlying layer. The formation of S-O bonds upon short, remote plasma exposure pins the surface Fermi level to the conduction band edge, while the MoOx formation at high temperature modulates the Fermi level toward the valence band through band alignment. A uniform coverage of monolayer amorphous MoO3 is obtained after 5 min or longer remote O2 plasma exposure at 200 °C, and the MoO3 can be completely removed by annealing at 500 °C, leaving a clean ordered MoS2 lattice structure as verified by XPS, LEED, AFM, and scanning tunneling microscopy. This work shows that a remote O2 plasma can be useful for both surface functionalization and a controlled thinning method for MoS2 device fabrication processes.

  10. Effect of grape seed extract on postprandial oxidative status and metabolic responses in men and women with the metabolic syndrome - randomized, cross-over, placebo-controlled study

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    Indika Edirisinghe

    2012-12-01

    Full Text Available Objective: This investigation was undertaken to determine whether a grape seed extract (GSE that is rich in mono-, oligo- and poly- meric polyphenols would modify postprandial oxidative stress and inflammation in individuals with the metabolic syndrome (MetS.Background: MetS is known to be associated with impaired glucose tolerance and poor glycemic control. Consumption of a meal high in readily available carbohydrates and fat causes postprandial increases in glycemia and lipidemia and markers of oxidative stress, inflammation and insulin resistance. Materials/methods: After an overnight fast, twelve subjects with MetS (5 men and 7 women consumed a breakfast meal high in fat and carbohydrate in a cross-over design. A GSE (300 mg or placebo capsule was administrated 1 hr before the meal (-1 hr. Changes in plasma insulin, glucose, oxidative stress and inflammatory markers were measured hourly for 6 hr. Results: Plasma hydrophilic oxygen radical absorbance capacity (ORAC measured as the positive incremental area under the curve (-1 to 5 hr was significantly increased when the meal was preceded by GSE compared with placebo (P0.05. No changes in inflammatory markers were evident. Conclusion: These data suggest that GSE enhances postprandial plasma antioxidant status and reduces the glycemic response to a meal, high in fat and carbohydrate in subjects with the MetS.

  11. Losartan reduces oxidative damage to renal DNA and conserves plasma antioxidant capacity in diabetic rats.

    Science.gov (United States)

    Lodovici, Maura; Bigagli, Elisabetta; Tarantini, Francesca; Di Serio, Claudia; Raimondi, Laura

    2015-11-01

    Increased reactive oxygen species (ROS) levels produced by hyperglycemia and angiotensin-II (AT-II) are considered among the pathogenic factors in the malignant transformation of diabetic renal cells. We aimed to investigate the potential role of AT-II in the increased cancer risk seen in diabetes; measuring oxidative damage to renal DNA and protective antioxidant defenses, including adiponectin (Adp) and plasma antioxidant capacity by the Ferric Reducing Ability of Plasma (FRAP) method. In the kidney of streptozotocin (STZ)-induced (55 mg/kg) diabetic rats either treated or not treated for 3 weeks with losartan, an AT-II type 1 receptor antagonist (20 mg/kg/day); we measured 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) levels, as an index of oxidative DNA damage, circulating Adp and FRAP. Diabetic rats showed significantly higher 8-oxodGuo levels in renal DNA (8.48 ± 0.98 × 10(-6) dG, mean ± SEM n = 11) than normoglycemic ones (1.18 ± 0.04 × 10(-6) dG, mean ± SEM, n=7) and lower plasma Adp and FRAP levels in comparison to normoglycemics. The treatment of diabetic rats with losartan significantly (P Losartan treatment preserves FRAP levels, reduces DNA oxidative injury and thus the carcinogenesis risk. Furthermore, our results indicate that Adp plasma levels are a further marker of oxidative injury to the kidney and confirm that it is an important part of the plasma antioxidant defense.

  12. ANTIOXIDANT STATUS, OXIDATIVE STRESS AND LIPID PROF ILE IN ESSENTIAL HYPERTENSIVE MEN

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    Shantha Kumari

    2013-04-01

    Full Text Available ABSTRACT: Hypertension is a major health burden and coexists o f with imbalance in antioxidants and lipid profile. This study is done to evaluate the total antioxidant status and oxidative stress like Malondialdehyde (MDA, catala se, superoxide dismutase (SOD, uric acid and correlate with lipid profile among hypertensive m en. Significant increase in MDA, uric acid and dyslipidemia was found among hypertensive men. Al so total antioxidant status and other antioxidants like SOD, catalase was found to be dec reased in hypertensive men. Hence it is concluded that lipid peroxidation occur in hypertensi on which leads to endothelial dysfunction, renal blood flow alteration and tissue damage. As a result of which dyslipidemia, hyperuricemia and decrease in anti oxidants are seen. Hence decre ase in antioxidants is a useful marker for antioxidant therapy to prevent organ damage among hype rtensive.

  13. Plasma dynamic synthesis of ultradispersed zinc oxide and sintering ceramics on its basis by SPS method

    Science.gov (United States)

    Shanenkova, Yu; Sivkov, A.; Ivashutenko, A.; Shanenkov, I.; Firsov, K.

    2017-05-01

    Zinc oxide is a well-known semiconductor material having good electrical, optical and catalytic properties. It can be used in different areas from cosmetics to drug delivery and biosensors. The synthesis of nanosized zinc oxide is an urgent task for obtaining ZnO-based ceramics with enhanced physical properties. This work shows the possibility to implement the plasma dynamic synthesis of zinc oxide in one short-term process (less than 1 ms) using an electrodischarge zinc-containing plasma jet, flowing into oxygen atmosphere. It allows synthesizing a mono-crystalline powder with particle size distribution from tens to hundred nanometers. The synthesized powdered product is investigated using by X-Ray diffractometry (XRD), scanning electron microscopy and high-resolution transmission electron microscopy. According to XRD, the obtained product consists of hexagonal zinc oxide with lattice parameters a = b = 3.24982 Å, c = 5.20661 Å that is clearly confirmed by microscopy data. This powder was used to produce a bulk ceramics sample on its basis by spark plasma sintering. The influence of sintering parameters on the structure of the resulting sample was studied. The optimal parameters were found which allows obtaining the more dense ceramics with a better microstructure. It was also found that the absence of exposure time after reaching the working temperature and pressure allows decreasing the porosity of ceramics.

  14. Adsorption kinetics of organophosphonic acids on plasma-modified oxide-covered aluminum surfaces.

    Science.gov (United States)

    Giza, M; Thissen, P; Grundmeier, G

    2008-08-19

    Tailoring of oxide chemistry on aluminum by means of low-pressure water and argon plasma surface modification was performed to influence the kinetics of the self-assembly process of octadecylphosphonic acid monolayers. The plasma-induced surface chemistry was studied by in situ FTIR reflection-absorption spectroscopy (IRRAS). Ex situ IRRAS and X-ray photoelectron spectroscopy were applied for the analysis of the adsorbed self-assembled monolayers. The plasma-induced variation of the hydroxide to oxide ratio led to different adsorption kinetics of the phosphonic acid from dilute ethanol solutions as measured by means of a quartz crystal microbalance. Water plasma treatment caused a significant increase in the density of surface hydroxyl groups in comparison to that of the argon-plasma-treated surface. The hydroxyl-rich surface led to significantly accelerated adsorption kinetics of the phosphonic acid with a time of monolayer formation of less than 1 min. On the contrary, decreasing the surface hydroxyl density slowed the adsorption kinetics.

  15. Oxidative damage of workers in secondary metal recovery plants affected by smoking status and joining the smelting work.

    Science.gov (United States)

    Chia, Taipau; Hsu, Ching Yi; Chen, Hsiu Ling

    2008-04-01

    In Taiwan, secondary copper smelters and zinc recovery plants primarily utilize recovering metal from scrap and dross, and handles mostly fly ash and slag with high temperature to produce ZnO from the iron and steel industry. The materials may contain organic impurities, such as plastic and organic chloride chemicals, and amounts of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) are produced during the smelting process. Therefore, secondary metal recovery industries are major emission sources of PCDD/Fs, which may have been demonstrated to elicit oxidative stress and to involve the production of plasma malondialdehyde (MDA). Many studies have also indicated that the intake of antioxidants, smoking, age and exposure to environmental pollutants may be implicated to DNA damage or lipid peroxidation. This study therefore aims to elucidate the roles of occupational exposure like joining the smelting work, age, smoking and alcohol status, and antioxidant intake on oxidative damage in secondary metal recovery workers in Taiwan. 73 workers were recruited from 2 secondary metal recovery plants. The analysis of 8-hydroxydeoxyguanosine (8-OH-dG) in urine, DNA strand breakage (comet assay) and lipid peroxidation (MDA) in blood samples were completed for all of the workers. The results showed that the older subjects exhibited significantly lower levels of 8-OH-dG and MDA than younger subjects. Our investigation also showed that working departments were in related to plasma MDA and DNA strand breakage levels of nonsmokers, however, the observation become negligible in smokers. And it is implicated that cigarette type might affect 8-OH-dG levels in secondary metal recovery workers. Since, adding to results above, the MDA level in production workers was significantly higher than those in managerial departments, it is important for the employers to make efforts on improving occupational environments or serving protective equipments to protect workers

  16. Evaluating Oxidative Stress Factors Induced by Chlorpyrifos Poisoning in Plasma of Wistar Rat

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    M Saberi

    2014-06-01

    Results: The oral administration of CPF could induce symptoms such as tremors, hair erection, weakness, diarrhea and asthma on Day 7 and onward. The data analysis of plasma samples showed significant (P<0.001 decrease in the levels of glutathione and CAT enzymatic activity and a significant increase in SOD enzymatic activity and the MDA level. Conclusion: CPF could induce oxidative stress probably via production of free radicals as was evident by reduction of GSH level and CAT activity accompanied by increase in the activity of SOD and enhancement in the level of MDA in plasma samples. This necessitates the application of antioxidants when having exposure with OP pesticides.

  17. Determination of fetal rhesus d status by maternal plasma DNA analysis.

    Science.gov (United States)

    Aykut, A; Onay, H; Sagol, S; Gunduz, C; Ozkinay, F; Cogulu, O

    2013-12-01

    In this study, we assessed the feasibility of fetal RhD genotyping by analysis of cell-free fetal DNA(cffDNA) extracted from plasma samples of Rhesus (Rh) D-negative pregnant women by using real-time polymerase chain reaction (PCR). Fetal genotyping was performed on 30 RhD-negative women between 9 and 39 weeks of gestation who were referred to us for invasive testing [amniocentesis/chorionic villi sampling (CVS)]. The fetal RHD genotype was determined based on real-time PCR method. Exons 7 and 10 of the RHD and SRY genes were targeted. Among the pregnant women, 12 were carrying male and 17 were carrying female fetuses. Out of 29 pregnant women, 21 had RhD-positive and nine had RhD-negative fetuses. One sample (case 12, whose blood group was found to be AB Rh [+]) was excluded due to controversial results from repeated serological analyses. All prenatal results were in concordance with postnatal RhD status and fetal sex without false- positive or -negative results. Performing real-time PCR on cffDNA showed accurate, efficient and reliable results, allowing rapid and high throughput non invasive determination of fetal sex and RhD status in clinical samples.

  18. Tantalum-Tungsten Oxide Thermite Composite Prepared by Sol-Gel Synthesis and Spark Plasma Sintering

    Energy Technology Data Exchange (ETDEWEB)

    Cervantes, O; Kuntz, J; Gash, A; Munir, Z

    2009-02-13

    Energetic composite powders consisting of sol-gel derived nanostructured tungsten oxide were produced with various amounts of micrometer-scale tantalum fuel metal. Such energetic composite powders were ignition tested and results show that the powders are not sensitive to friction, spark and/or impact ignition. Initial consolidation experiments, using the High Pressure Spark Plasma Sintering (HPSPS) technique, on the sol-gel derived nanostructured tungsten oxide produced samples with higher relative density than can be achieved with commercially available tungsten oxide. The sol-gel derived nanostructured tungsten oxide with immobilized tantalum fuel metal (Ta - WO{sub 3}) energetic composite was consolidated to a density of 9.17 g.cm{sup -3} or 93% relative density. In addition those parts were consolidated without significant pre-reaction of the constituents, thus the sample retained its stored chemical energy.

  19. Study of Coating Growth Behavior During the Plasma Electrolytic Oxidation of Magnesium Alloy ZK60

    Science.gov (United States)

    Qiu, Zhaozhong; Wang, Rui; Zhang, Yushen; Qu, Yunfei; Wu, Xiaohong

    2015-04-01

    Plasma electrolytic oxidation technique was used to coat ZK60 magnesium alloy in a silicate-based electrolyte. Effects of oxidation time on the morphology, phase structure, and corrosion resistance of the resulting coatings were systematically investigated by scanning electron microscopy, energy-dispersive spectrometry, x-ray diffraction, x-ray photoelectron spectroscopy, and potentiodynamic polarization. The main components of the inner and the outer coating layers were MgO and Mg2SiO4, respectively. It was also found that the oxidation time has a significant impact on the corrosion resistance properties of the coatings. The coating obtained within the oxidation time of 360 s exhibited a corrosion current of 7.6 × 10-8 A/cm2 in 3.5 wt.% NaCl solution, which decreased significantly when comparing with the pristine magnesium alloy.

  20. Effects of α-Tocopherol on Oxidative Status and Metabolic Profile in Overweight Women

    Science.gov (United States)

    Ble-Castillo, J. L.; Cleva-Villanueva, G.; Díaz-Zagoya, J. C.; Medina-Santillán, R.; Rubio-Arias, H. O.; Méndez, J. D.

    2007-01-01

    Despite extensive research, the effects of α-tocopherol supplementation remain controversial. Few studies have been focused on obese and overweight people. We examined the effects of α-tocopherol (AT) on the oxidative status and metabolic profile in overweight women. Sixteen overweight women between the ages of 40–60 years old, received AT, 800 IU/day during 12 weeks, followed by a 6-week washout period. Blood samples were taken at the beginning and then every 6 weeks until the end of the study. AT, retinol, malondialdehyde (MDA), total antioxidant status (TAS), selenium-dependent glutathione peroxidase (GPx) and CuZn-superoxide dismutase (SOD) were quantified to evaluate the oxidative stress. The metabolic profile was estimated by measuring glycated hemoglobin (HbA1c) in erythrocytes and glucose, phosphate, magnesium, lipid and lipoprotein concentrations in serum. Under AT administration HbA1c, serum-MDA levels and erythrocyte GPx activity were markedly reduced. TAS, AT and Mg2+ concentrations in serum and SOD activity in erythrocytes were higher after AT treatment. Body weight; glucose, lipid and retinol concentrations, or blood cells count were unchanged. Lipid peroxidation was considerably reduced in AT treated women and also improved serum antioxidant status was observed, but the imbalanced response between erythrocyte SOD and GPx activities could affect normal response to oxidative stress. PMID:18180536

  1. Comparative evaluation of antioxidant drug influence on a radio therapy efficiency and oxidative status in mice

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    Alexander V. Siprov

    2013-09-01

    Full Text Available The aim of the study is a comparative analysis of the effect of melatonin (Melaxen and 3-hydroxypyridine (Mexidol on antitumor and antimetastatic influence of chemoradiotherapy and oxidative status at mice with Lewis lung carcinoma. Material — Experiments have been organized on 95 mice of C57Bl/6 line and of 20–22 g in weight. Cyclophosphan has been abdominally administered two times in a dosage of 60 mg/kg within the interval of 120 hours — 20-30 min before radiotherapy. It has been located on the area of initial tumor in a dosage of 2 g at the same time as cyclophosphan injection. Melaxen and Mexidol have been intramuscularly injecting in the dosage of 45 and 50 mg/ kg for 14 days. Antitumor and antimetastatic effect of the applied therapy and changes in the oxidative status of the animals have been estimated. Results — Melaxen and Mexidol do not decrease antitumour and antimetastatic effects of radiotherapy and prevent the activation of free radical processes at animals with tumors. Mexidol was more effective than Melaxen in correction of superoxide dismutase activity in liver. The drugs under the study do not decrease radiotherapy-induced lipid peroxidation in the initial tumor. Conclusion — Melaxen and Mexidol do not decrease the radio therapy efficiency and oxidative status at mice with tumor (on the background of antitumor treatment.

  2. Inhibition of central angiotensin II enhances memory function and reduces oxidative stress status in rat hippocampus.

    Science.gov (United States)

    Bild, Walther; Hritcu, Lucian; Stefanescu, Cristinel; Ciobica, Alin

    2013-06-03

    While it is now well established that the independent brain renin-angiotensin system (RAS) has some important central functions besides the vascular ones, the relevance of its main bioactive peptide angiotensin II (Ang II) on the memory processes, as well as on oxidative stress status is not completely understood. The purpose of the present work was to evaluate the effects of central Ang II administration, as well as the effects of Ang II inhibition with either AT1 and AT 2 receptor specific blockers (losartan and PD-123177, respectively) or an angiotensin-converting enzyme (ACE) inhibitor (captopril). These effects were studied on the short-term memory (assessed through Y-maze) or long-term memory (as determined in passive avoidance) and on the oxidative stress status of the hippocampus. Our results demonstrate memory deficits induced by the administration of Ang II, as showed by the significant decrease of the spontaneous alternation in Y-maze (p=0.015) and latency-time in passive avoidance task (p=0.001) when compared to saline. On the other side, the administration of all the aforementioned Ang II blockers significantly improved the spontaneous alternation in Y-maze task, while losartan also increased the latency time as compared to saline in step-through passive avoidance (p=0.042). Also, increased oxidative stress status was induced in the hippocampus by the administration of Ang II, as demonstrated by increased levels of lipid peroxidation markers (malondialdehyde-MDA concentration) (p0.0001) vs. saline. Moreover, significant correlations were found between all of the memory related behavioral parameters and the main oxidative stress markers from the hippocampus, which is known for its implication in the processes of memory and also where RAS components are well expressed. This could be relevant for the complex interactions between Ang II, behavioral processes and neuronal oxidative stress, and could generate important therapeutic approaches. Copyright

  3. Nitric Oxide Plasma Level as a Barometer of Endothelial Dysfunction in Factory Workers.

    Science.gov (United States)

    Miyata, Seiko; Noda, Akiko; Hara, Yuki; Ueyama, Jun; Kitaichi, Kiyoyuki; Kondo, Takaaki; Koike, Yasuo

    2017-07-27

    Objective Nitric oxide (NO) plays a key role in the regulation of vascular tone and is known as one of the key markers of endothelial dysfunction. We investigated the relationship between NO and risk factors of lifestyle-related disease in factory workers. Methods Our study included 877 factory workers presenting hypertension, dyslipidemia and type 2 diabetes. oxidated forms of NO, NO2-/NO3- (NOx) plasma concentrations were measured using a colorimetric method. Results NOx plasma levels in patients with lifestyle-related disease were significantly lower than those in the controls. The brachial-ankle pulse wave velocity (baPWV) measured in those patients was significantly greater than that of the controls. Multiple regression analysis revealed that LDL cholesterol was an independent risk factor for reducing NOx plasma concentrations. Interestingly, individuals with low NOx plasma concentrations were more likely to present type 2 diabetes compared to those with the highest plasma levels of NOx (odds ratio [OR] [95% confidence interval; CI]=3.65 [1.61-8.28], P=0.002, 2.67 [1.15-6.20], P=0.022, and 3.27 [1.43-7.48], P=0.005). Subjects with the lowest levels of plasma NOx were more likely to present dyslipidemia (OR [95% CI]=1.69 [1.13-2.53], P=0.01). Conclusion Endothelial function evaluated with plasma NOx may be indicative of lifestyle-related diseases independently from the vascular function assessed using baPWV. © Georg Thieme Verlag KG Stuttgart · New York.

  4. Impact of nutrient excess and endothelial nitric oxide synthase on the plasma metabolite profile in mice

    Directory of Open Access Journals (Sweden)

    Brian E Sansbury

    2014-11-01

    Full Text Available An increase in calorie consumption is associated with the recent rise in obesity prevalence. However, our current understanding of the effects of nutrient excess on major metabolic pathways appears insufficient to develop safe and effective metabolic interventions to prevent obesity. Hence, we sought to identify systemic metabolic changes caused by nutrient excess and to determine how endothelial nitric oxide synthase (eNOS—which has anti-obesogenic properties—affects systemic metabolism by measuring plasma metabolites. Wild-type (WT and eNOS transgenic (eNOS-TG mice were placed on low fat or high fat diets for six weeks, and plasma metabolites were measured using an unbiased metabolomic approach. High fat feeding in WT mice led to significant increases in fat mass, which was associated with significantly lower plasma levels of 1,5-anhydroglucitol, lysophospholipids, 3-dehydrocarnitine, and bile acids, as well as branched chain amino acids (BCAAs and their metabolites. Plasma levels of several lipids including sphingomyelins, stearoylcarnitine, dihomo-linoleate and metabolites associated with oxidative stress were increased by high fat diet. In comparison with low fat-fed WT mice, eNOS-TG mice showed lower levels of several free fatty acids, but in contrast, the levels of bile acids, amino acids, and BCAA catabolites were increased. When placed on a high fat diet, eNOS overexpressing mice showed remarkably higher levels of plasma bile acids and elevated levels of plasma BCAAs and their catabolites compared with WT mice. Treatment with GW4064, an inhibitor of bile acid synthesis, decreased plasma bile acid levels but was not sufficient to reverse the anti-obesogenic effects of eNOS overexpression. These findings reveal unique metabolic changes in response to high fat diet and eNOS overexpression and suggest that the anti-obesity effects of eNOS are likely independent of changes in the bile acid pool.

  5. Exogenous nitric oxide (NO) generated by NO-plasma treatment modulates osteoprogenitor cells early differentiation

    Science.gov (United States)

    Elsaadany, Mostafa; Subramanian, Gayathri; Ayan, Halim; Yildirim-Ayan, Eda

    2015-09-01

    In this study, we investigated whether nitric oxide (NO) generated using a non-thermal plasma system can mediate osteoblastic differentiation of osteoprogenitor cells without creating toxicity. Our objective was to create an NO delivery mechanism using NO-dielectric barrier discharge (DBD) plasma that can generate and transport NO with controlled concentration to the area of interest to regulate osteoprogenitor cell activity. We built a non-thermal atmospheric pressure DBD plasma nozzle system based on our previously published design and similar designs in the literature. The electrical and spectral analyses demonstrated that N2 dissociated into NO under typical DBD voltage-current characteristics. We treated osteoprogenitor cells (MC3T3-E1) using NO-plasma treatment system. Our results demonstrated that we could control NO concentration within cell culture media and could introduce NO into the intracellular space using NO-plasma treatment with various treatment times. We confirmed that NO-plasma treatment maintained cell viability and did not create any toxicity even with prolonged treatment durations. Finally, we demonstrated that NO-plasma treatment induced early osteogenic differentiation in the absence of pro-osteogenic growth factors/proteins. These findings suggest that through the NO-plasma treatment system we are able to generate and transport tissue-specific amounts of NO to an area of interest to mediate osteoprogenitor cell activity without subsequent toxicity. This opens up the possibility to develop DBD plasma-assisted tissue-specific NO delivery strategies for therapeutic intervention in the prevention and treatment of bone diseases.

  6. Plasma surface oxidation of 316L stainless steel for improving adhesion strength of silicone rubber coating to metal substrate

    Energy Technology Data Exchange (ETDEWEB)

    Latifi, Afrooz, E-mail: afroozlatifi@yahoo.com [Department of Biomaterials, Biomedical Engineering Faculty, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Imani, Mohammad [Novel Drug Delivery Systems Dept., Iran Polymer and Petrochemical Institute, P.O. Box 14965/115, Tehran (Iran, Islamic Republic of); Khorasani, Mohammad Taghi [Biomaterials Dept., Iran Polymer and Petrochemical Institute, P.O. Box 14965/159, Tehran (Iran, Islamic Republic of); Daliri Joupari, Morteza [Animal and Marine Biotechnology Dept., National Institute of Genetic Engineering and Biotechnology, P.O. Box 14965/161, Tehran (Iran, Islamic Republic of)

    2014-11-30

    Highlights: • Stainless steel 316L was surface modified by plasma surface oxidation (PSO) and silicone rubber (SR) coating. • On the PSO substrates, concentration of oxide species was increased ca. 2.5 times comparing to non-PSO substrates. • The surface wettability was improved to 12.5°, in terms of water contact angle, after PSO. • Adhesion strength of SR coating on the PSO substrates was improved by more than two times comparing to non-PSO ones. • After pull-off test, the fractured area patterns for SR coating were dependent on the type of surface modifications received. - Abstract: Stainless steel 316L is one of the most widely used materials for fabricating of biomedical devices hence, improving its surface properties is still of great interest and challenging in biomaterial sciences. Plasma oxidation, in comparison to the conventional chemical or mechanical methods, is one of the most efficient methods recently used for surface treatment of biomaterials. Here, stainless steel specimens were surface oxidized by radio-frequency plasma irradiation operating at 34 MHz under pure oxygen atmosphere. Surface chemical composition of the samples was significantly changed after plasma oxidation by appearance of the chromium and iron oxides on the plasma-oxidized surface. A wettable surface, possessing high surface energy (83.19 mN m{sup −1}), was observed after plasma oxidation. Upon completion of the surface modification process, silicone rubber was spray coated on the plasma-treated stainless steel surface. Morphology of the silicone rubber coating was investigated by scanning electron microscopy (SEM). A uniform coating was formed on the oxidized surface with no delamination at polymer–metal interface. Pull-off tests showed the lowest adhesion strength of coating to substrate (0.12 MPa) for untreated specimens and the highest (0.89 MPa) for plasma-oxidized ones.

  7. Multi-physics study of plasma in liquids: The case of Plasma Electrolytic Oxidation (PEO)

    Science.gov (United States)

    Nomine, Alexandre; Troughton, Sam; Nomine, Anna; Henrion, Gerard; Clyne, Bill

    2015-09-01

    PEO is a promising technique in order to grow rapidly oxide coatings with high corrosion and wear resistance. Oxidation is driven by millions of simultaneous micro-discharges (MD) that occur at the interface between the substrate and the liquid electrolyte. However, the mechanisms of breakdown and the subsequent oxidation are not well understood yet. Current profiles and Ultra-Fast Imaging of single discharges allows to correlate the size and life-time of the discharge with different electric parameters (Q, Imax). MD are found to appear in cascade, switching on and off with a frequency in the order of 1-10 kHz. Formation of a bubble is observed directly after the ignition of the discharge. The growth rate that varies between 1 and 10 m/s, is used to estimate the gas pressure in the bubble. The influence of the pulse frequency on the bubble shape and on the coatings will be presented. MD size and life time are known to increase with coating thickness presumably due to higher charge accumulation. This study shows that ms scale, the evolution of MD size and life time evaluates similarly, suggesting that the coating thickness is not the only parameter governing the MD size and life-time. second affiliation: The Open University.

  8. Oxidation behavior of plasma sintered beryllium–titanium intermetallic compounds as an advanced neutron multiplier

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae-Hwan, E-mail: kim.jaehwan@jaea.go.jp; Nakamichi, Masaru

    2013-07-15

    Beryllium intermetallic compounds (beryllides) such as Be{sub 12}Ti are very promising candidates for advanced neutron multiplier materials in a demonstration fusion power reactor (DEMO). However, beryllides are too brittle to be fabricated either into pebble-type or rod-type shapes via conventional methods (i.e. arc melting and hot isostatic pressing). We have proposed a plasma sintering technique as a new method for beryllide fabrication, and our studies on the properties of plasma sintered beryllides are ongoing. In the present work, the oxidation properties of plasma sintered beryllides were investigated at 1273 K for 24 h in a dry air atmosphere to evaluate the high temperature properties of this material. Thermal gravimetry measurements indicate that specimens with larger fractions of Be{sub 12}Ti phase corresponding to samples that have been sintered for longer time periods, exhibit superior oxidation properties. Our evaluation of the oxidation behavior of each phase in our beryllide samples is as follows: Be{sub 12}Ti and Be{sub 17}Ti{sub 2} both have good oxidation resistance, owing to the formation of dense and protective scales, while the Be and Be{sub 2}Ti phases are mainly responsible for thermal-gravimetry (TG) weight gains, which is indicative of severe oxidation. We attribute the degradation in oxidation resistance specifically to Be{sub 2}Ti that transforms into TiO{sub 2}, and also find this phase to be the cause of deterioration in the mechanical properties of samples, owing to cracks near Be{sub 2}Ti phase conglomerates.

  9. Development and evaluation of magnesium oxide-based ceramics for chamber parts in mass-production plasma etching equipment

    Science.gov (United States)

    Kasashima, Yuji; Tsutsumi, Kota; Mitomi, Shinzo; Uesugi, Fumihiko

    2017-06-01

    In mass-production plasma etching equipment, the corrosion of ceramic chamber parts reduces the production yield of LSI and overall equipment effectiveness (OEE) owing to contamination, short useful life, and particle generation. Novel ceramics that can improve the production yield and OEE are highly required. We develop magnesium oxide (MgO)-based ceramics and evaluate them under mass-production plasma etching conditions. The results of this study indicate that the developed MgO-based ceramics with high mechanical properties and low electric resistivity have a higher resistance to corrosion in plasma etching using CF4 gas than Si and conventional ceramic materials such as aluminum oxide and yttrium oxide.

  10. Hubungan Aktivitas Fisik dengan Kadar Nitric Oxide (NO Plasma pada Masyarakat di Kota Padang

    Directory of Open Access Journals (Sweden)

    Ghozi Natul Isral

    2014-05-01

    Full Text Available AbstrakNitric oxide merupakan faktor relaksan yang disentesis oleh endotel pembuluh darah yang kadarnya dapat dipengaruhi oleh aktivitas fisik. Penelitian ini bertujuan untuk mengetahui hubungan aktivitas fisik dengan kadar NO plasma pada masyarakat di kota Padang. Penelitian ini merupakan penelitian dengan data sekunder dari penelitian Delmi Sulastri dkk dalam “Pengaruh Asupan Antioksidan terhadap ekspresi Gen eNOS3 pada penderita Hipertensi Etnik Minangkabau”. Subyek penelitian adalah semua responden penelitian Delmi Sulastri dkk dalam “Pengaruh Asupan Antioksidan terhadap ekspresi Gen eNOS3 pada Penderita Hipertensi Etnik Minangkabau” berjumlah 130 orang yang dinilai aktivitas fisiknya dengan menggunakan kuisioner Baecke dkk. dan dilakukan pemeriksaan kadar NO plasma. Hasil penelitian menunjukkan bahwa sebagian besar responden memiliki tingkat aktivitas fisik ringan dan NO plasma rendah dengan dengan rerata 26,3±15,2 μmol/L. Dari analisis data didapatkan bahwa responden dengan aktivitas fisik ringan lebih banyak memiliki kadar NO plasma rendah (61,7% dibandingkan kadar NO plasma normal (38,3%. Dari analisis statistik uji Chi-Square didapatkan nilai p = 0,007 yang berarti terdapat hubungan bermakna antara aktivitas fisik dengan kadar NO plasma (p<0,05. Kesimpulan penelitian ini adalah sebagian besar masyarakat di kota Padang memiliki tingkat aktivitas fisik ringan dan kadar NO plasma rendah. Dari uji statistik menunjukkan bahwa terdapat hubungan bermakna antara aktivitas fisik dengan kadar NO plasma pada masyarakat di kota Padang.Kata kunci: Aktivitas fisik, NOAbstractNitric oxide is relaxan factor that is synthesized by endothelial cell of blood vessel. From previous research showed that plasma NO level influenced by physical activity. The purpose of this study is to know correlation between physical activity with plasma NO level to Padang city people. The research is a research with secondary data by Delmi Sulastri et al., in

  11. Microstructure and Oxidation Resistance of Laser Remelted Plasma Sprayed Nicraly Coating

    Directory of Open Access Journals (Sweden)

    Niemiec D.

    2016-06-01

    Full Text Available The article presents results of research relating to the impact of laser treatment done to the surface of plasma sprayed coatings NiCrAlY. Analysis consisted microstructure and oxidation resistance of coatings subjected to two different laser melting surfaces. The test were performed at a temperature 1000°C the samples were removed from the furnace after 25, 300, 500, 750 and 1000 hours. The investigations range included analysis of top surface of coatings by XRD characterization oxides formed types and microscopic investigations of coatings morphology

  12. Corrosion behavior of plasma electrolytically oxidized gamma titanium aluminide alloy in simulated body fluid.

    Science.gov (United States)

    Lara Rodriguez, L; Sundaram, P A

    2016-09-15

    Plasma electrolytic oxidized (PEO) γTiAl alloy samples were electrochemically characterized by open circuit potential (OCP), cyclic polarization and electrochemical impedance spectroscopy (EIS) to evaluate their corrosion resistance in simulated body fluid (SBF) in order to gauge their potential for biomedical applications. Experimental results through OCP and cyclic polarization studies demonstrated the protective nature and the beneficial effect of the PEO coatings on γTiAl. The PEO surface increased corrosion resistance of these surface modified alloys. EIS data indicated the presence of an underlying compact oxide layer with surface pores represented by two domes in the Nyquist plots. Electrical equivalent circuits to describe the EIS results are proposed.

  13. Altered DNA repair, oxidative stress and antioxidant status in coronary artery disease

    Indian Academy of Sciences (India)

    A Supriya Simon; V Chithra; Anoop Vijayan; Roy D Dinesh; T Vijayakumar

    2013-06-01

    Coronary artery disease (CAD) is a multifactorial disease caused by the interplay of environmental risk factors with multiple predisposing genes. The present study was undertaken to evaluate the role of DNA repair efficiency and oxidative stress and antioxidant status in CAD patients. Malonaldehyde (MDA), which is an indicator of oxidative stress, and mean break per cell (b/c) values, which is an indicator of decreased DNA repair efficiency, were found to be significantly increased in patients compared to normal controls ( < 0.05) whereas ascorbic acid and GSH were found to be lower among patients than the control group. It has been found that elevated oxidative stress decreased antioxidant level and decreased DNA repair efficiency can contribute to the development of CAD. This study also showed that high MDA, low ascorbic acid and GSH were significantly associated with high b/c value.

  14. Non-thermal atmospheric pressure HF plasma source: generation of nitric oxide and ozone for bio-medical applications

    Science.gov (United States)

    Kühn, S.; Bibinov, N.; Gesche, R.; Awakowicz, P.

    2010-01-01

    A new miniature high-frequency (HF) plasma source intended for bio-medical applications is studied using nitrogen/oxygen mixture at atmospheric pressure. This plasma source can be used as an element of a plasma source array for applications in dermatology and surgery. Nitric oxide and ozone which are produced in this plasma source are well-known agents for proliferation of the cells, inhalation therapy for newborn infants, disinfection of wounds and blood ozonation. Using optical emission spectroscopy, microphotography and numerical simulation, the gas temperature in the active plasma region and plasma parameters (electron density and electron distribution function) are determined for varied nitrogen/oxygen flows. The influence of the gas flows on the plasma conditions is studied. Ozone and nitric oxide concentrations in the effluent of the plasma source are measured using absorption spectroscopy and electro-chemical NO-detector at variable gas flows. Correlations between plasma parameters and concentrations of the particles in the effluent of the plasma source are discussed. By varying the gas flows, the HF plasma source can be optimized for nitric oxide or ozone production. Maximum concentrations of 2750 ppm and 400 ppm of NO and O3, correspondingly, are generated.

  15. Elevated tissue Cr levels, increased plasma oxidative markers, and global hypomethylation of blood DNA in male Sprague-Dawley rats exposed to potassium dichromate in drinking water.

    Science.gov (United States)

    Wang, Yu; Wu, Wei; Yao, Chunji; Lou, Jianlin; Chen, Riping; Jin, Lingzhi; Wu, Nanxiang; Gao, Ming; Song, Peng; Tan, Yufeng; Liu, Kecheng

    2016-09-01

    Hexavalent chromium [Cr (VI)] is prevalent in ground water in some areas, but evidence on the toxic effects of Cr (VI) via ingestion through drinking water remains insufficient. The aims of our study were to investigate the toxic effects of Cr (VI) through oral water ingestion on oxidative stress and DNA methylation. Thirty-two Sprague-Dawley rats were randomly divided into four groups, and exposed to porassium dichromate (K2 Cr2 O7 ; 0, 30, 100, and 300 mg/L) in drinking water for 4 weeks. Mean body weight gain, mean water consumption, clinical chemistry determinations, and oxidative stress levels in plasma were measured. Global DNA methylation changes and DNA methylation status at the promoter of p16 gene were also detected. After 4 weeks, mild anemic effects and increased plasma malondialdehyde (MDA) levels occurred in rats exposed to 100 mg/L or 300 mg/L of Cr (VI). Plasma glutathione peroxidase (GSH-Px) activity decreased in all exposed groups. Global DNA methylation levels were reduced in 100 mg/L and 300 mg/L exposure groups. However, DNA methylation status at the promoter of P16 gene remained unchanged in all K2 Cr2 O7- treated groups. The correlation analysis indicated that increased MDA levels were closely correlated to global DNA hypomethylation. Our results indicated that oral ingestion of Cr (VI) through drinking water caused not only oxidative stress in plasma, but also global DNA hypomethylation in blood cells from male rats, and a good correlation was found between increased MDA levels and reduced global DNA methylation. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1080-1090, 2016.

  16. Oxidation of laser-induced plasma species in different background conditions

    Science.gov (United States)

    Bator, Matthias; Schneider, Christof W.; Lippert, Thomas; Wokaun, Alexander

    2013-08-01

    The evolution of Lu and LuO species in a laser ablation plasma from different targets has been investigated by simultaneously performing mass spectrometry and plasma imaging. Ablation was achieved with a 248 nm KrF laser from a Lu, a Lu2O5 and a LuMnO3 target under different background gas conditions. Mass spectrometry measurements show very similar intensities and ratios for the respective species for all three targets under the same ablation conditions. This indicates only a small influence of the target on the final Lu and LuO contents in the plasma, with the major influence coming from collisions with the background gas. Furthermore, spatially, timely and spectrally resolved plasma imaging was utilized to clearly identify the shockwave at the plasma front as the main region for Lu oxidation. A strong decrease of Lu intensities together with a directly correlated increase of LuO was observed toward the outer regions of the plasma.

  17. Optimizing the electrical excitation of an atmospheric pressure plasma advanced oxidation process.

    Science.gov (United States)

    Olszewski, P; Li, J F; Liu, D X; Walsh, J L

    2014-08-30

    The impact of pulse-modulated generation of atmospheric pressure plasma on the efficiency of organic dye degradation has been investigated. Aqueous samples of methyl orange were exposed to low temperature air plasma and the degradation efficiency was determined by absorbance spectroscopy. The plasma was driven at a constant frequency of 35kHz with a duty cycle of 25%, 50%, 75% and 100%. Relative concentrations of dissolved nitrogen oxides, pH, conductivity and the time evolution of gas phase ozone were measured to identify key parameters responsible for the changes observed in degradation efficiency. The results indicate that pulse modulation significantly improved dye degradation efficiency, with a plasma pulsed at 25% duty showing a two-fold enhancement. Additionally, pulse modulation led to a reduction in the amount of nitrate contamination added to the solution by the plasma. The results clearly demonstrate that optimization of the electrical excitation of the plasma can enhance both degradation efficiency and the final water quality.

  18. Creation of hydrophilic nitric oxide releasing polymers via plasma surface modification.

    Science.gov (United States)

    Pegalajar-Jurado, A; Joslin, J M; Hawker, M J; Reynolds, M M; Fisher, E R

    2014-08-13

    Herein, we describe the surface modification of an S-nitrosated polymer derivative via H2O plasma treatment, resulting in polymer coatings that maintained their nitric oxide (NO) releasing capabilities, but exhibited dramatic changes in surface wettability. The poly(lactic-co-glycolic acid)-based hydrophobic polymer was nitrosated to achieve a material capable of releasing the therapeutic agent NO. The NO-loaded films were subjected to low-temperature H2O plasma treatments, where the treatment power (20-50 W) and time (1-5 min) were varied. The plasma treated polymer films were superhydrophilic (water droplet spread completely in plasma-treated materials; however, they still result in physiologically relevant NO fluxes. XPS, SEM-EDS, and ATR-IR characterization suggests the plasma treatment resulted in polymer rearrangement and implantation of hydroxyl and carbonyl functional groups. Plasma treated samples maintained both hydrophilic surface properties and NO release profiles after storage at -18 °C for at least 10 days, demonstrating the surface modification and NO release capabilities are stable over time. The ability to tune polymer surface properties while maintaining bulk properties and NO release properties, and the stability of those properties under refrigerated conditions, represents a unique approach toward creating enhanced therapeutic biopolymers.

  19. Empirical modeling of plasma clouds produced by the Metal Oxide Space Clouds experiment

    Science.gov (United States)

    Pedersen, Todd R.; Caton, Ronald G.; Miller, Daniel; Holmes, Jeffrey M.; Groves, Keith M.; Sutton, Eric

    2017-05-01

    The Advanced Research Project Agency (ARPA) Long-Range Tracking And Instrumentation Radar (ALTAIR) radar at Kwajalein Atoll was used in incoherent scatter mode to measure plasma densities within two artificial clouds created by the Air Force Research Laboratory (AFRL) Metal Oxide Space Clouds (MOSC) experiment in May 2013. Optical imager, ionosonde, and ALTAIR measurements were combined to create 3-D empirical descriptions of the plasma clouds as a function of time, which match the radar measurements to within 15%. The plasma clouds closely track the location of the optical clouds, and the best fit plasma cloud widths are generally consistent with isotropic neutral diffusion. Cloud plasma densities decreased as a power of time, with exponents between -0.5 and -1.0, or much more slowly than the -1.5 predicted by diffusion. These exponents and estimates of total ion number from integration through the model volume are consistent with a scenario of slow ionization and a gradually increasing total number of ions with time, reaching a net ionization fraction of 20% after approximately half an hour. These robust representations of the plasma density are being used to study impacts of the artificial clouds on the dynamics of the background ionosphere and on RF propagation.

  20. Effect of atmospheric oxidative plasma treatments on polypropylenic fibers surface: Characterization and reaction mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Nisticò, Roberto, E-mail: roberto.nistico@unito.it [University of Torino, Department of Chemistry and NIS Centre of Excellence, Via P. Giuria 7, 10125 Torino (Italy); Magnacca, Giuliana [University of Torino, Department of Chemistry and NIS Centre of Excellence, Via P. Giuria 7, 10125 Torino (Italy); Faga, Maria Giulia; Gautier, Giovanna [CNR-IMAMOTER, Strada delle Cacce 73, 10135 Torino (Italy); D’Angelo, Domenico; Ciancio, Emanuele [Clean-NT Lab, Environment Park S.p.A., Via Livorno 60, 10144 Torino (Italy); Lamberti, Roberta; Martorana, Selanna [Herniamesh S.r.l., Via F.lli Meliga 1/C, 10034 Chivasso (Italy)

    2013-08-15

    Atmospheric pressure plasma-dielectric barrier discharge (APP-DBD, open chamber configuration) was used to functionalize polypropylene (PP) fibers surface in order to generate oxidized-reactive groups such as hydroperoxides, alcohols and carbonyl species (i.e. ketones and others). Such a species increased the surface polarity, without causing material degradation. Three different types of plasma mixture (He, He/O{sub 2}, He/O{sub 2}/H{sub 2}O) under three different values of applied power (750, 1050, 1400 W) were investigated. The formed plasma species (O{sub 2}{sup +}, O single atom and OH radical) and their distribution were monitored via optical emission spectrometry (OES) measurements, and the plasma effects on PP surface species formation were followed by X-ray photoemission spectroscopy (XPS). Results allowed to better understand the reaction pathways between plasma phase and PP fibers. In fact, two reaction mechanisms were proposed, the first one concerning the plasma phase reactions and the second one involving material surface modifications.

  1. 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.

  2. In vitro evaluation of cell proliferation and collagen synthesis on titanium following plasma electrolytic oxidation.

    Science.gov (United States)

    Whiteside, Paul; Matykina, Endzhe; Gough, Julie E; Skeldon, Peter; Thompson, George E

    2010-07-01

    Titania-based coatings produced by plasma electrolytic oxidation are being investigated as bioactive surfaces for titanium implants. In this study, plasma electrolytic oxidation was performed in calcium- and phosphorus-based electrolytes under DC conditions, resulting in coatings of thickness of approximately 8-15 mum. Coating morphologies, microstructures, and compositions were examined by scanning electron microscopy with energy-dispersive X-ray analysis, X-ray diffraction, and electron probe microanalysis. The coatings revealed a cratered morphology, with incorporated calcium and phosphorus species. Proliferation rates of primary human osteoblasts cells on the coatings were up to approximately 37% faster than those for uncoated titanium and 316L stainless steel reference materials. Further, the coatings assisted cell adhesion and generation and anchorage of collagen. The amount of collagen was upto approximately 2.4 times greater than for the reference substrates. (c) 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010.

  3. Cobalt oxide nanoparticles can enter inside the cells by crossing plasma membranes.

    Science.gov (United States)

    Bossi, Elena; Zanella, Daniele; Gornati, Rosalba; Bernardini, Giovanni

    2016-02-29

    The ability of nanoparticles (NPs) to be promptly uptaken by the cells makes them both dangerous and useful to human health. It was recently postulated that some NPs might cross the plasma membrane also by a non-endocytotic pathway gaining access to the cytoplasm. To this aim, after having filled mature Xenopus oocytes with Calcein, whose fluorescence is strongly quenched by divalent metal ions, we have exposed them to different cobalt NPs quantifying quenching as evidence of the increase of the concentration of Co(2+) released by the NPs that entered into the cytoplasm. We demonstrated that cobalt oxide NPs, but not cobalt nor cobalt oxide NPs that were surrounded by a protein corona, can indeed cross plasma membranes.

  4. Plasma surface modified TiO2 nanoparticles: improved photocatalytic oxidation of gaseous m-xylene.

    Science.gov (United States)

    Sumitsawan, Sulak; Cho, Jai; Sattler, Melanie L; Timmons, Richard B

    2011-08-15

    Titanium dioxide (TiO(2)) is a preferred catalyst for photocatalytic oxidation of many air pollutants. In an effort to enhance its photocatalytic activity, TiO(2) was modified by pulsed plasma treatment. In this work, TiO(2) nanoparticles, coated on a glass plate, were treated with a plasma discharge of hexafluoropropylene oxide (HFPO) gas. By appropriate adjustment of discharge conditions, it was discovered that the TiO(2) particles can be either directly fluorinated (Ti-F) or coated with thin perfluorocarbon films (C-F). Specifically, under relatively high power input, the plasma deposition process favored direct surface fluorination. The extent of Ti-F formation increased with increasing power input. In contrast, at lower average power inputs, perfluorocarbon films are deposited on the surface of the TiO(2) particles. The plasma surface modified TiO(2) nanoparticles were subsequently employed as catalysts in the photocatalytic oxidation of m-xylene in air, as carried out inside a batch reactor with closed loop constant gas circulation. Both types of modified TiO(2) were significantly more catalytically active than that of the unmodified particles. For example, the rate constant of m-xylene degradation was increased from 0.012 min(-1) with untreated TiO(2) to 0.074 min(-1) with fluorinated TiO(2). Although it is not possible to provide unequivocal reasons for this increased photocatalytic activity, it is noted that the plasma surface treatment converted the TiO(2) from hydrophilic to highly hydrophobic, which would provide more facile catalyst adsorption of the xylene from the flowing air. Also, based on literature reports, the use of fluorinated TiO(2) reduces electron-hole recombination rates, thus increasing the photocatalytic activity.

  5. Echium oil and linseed oil as alternatives for fish oil in the maternal diet: Blood fatty acid profiles and oxidative status of sows and piglets.

    Science.gov (United States)

    Tanghe, S; Millet, S; De Smet, S

    2013-07-01

    Echium oil (source of stearidonic acid) and linseed oil (source of α-linolenic acid) were evaluated as alternatives for fish oil in the diet of sows to increase the docosahexaenoic acid (DHA) status of the offspring. The hypothesis was that echium oil would be more efficient than linseed oil to increase the DHA concentration, as it bypasses the enzyme Δ6-desaturase. In addition, it was determined whether adding PUFA to the diet affected the plasma oxidative status. Sows were fed either a palm oil diet or a diet containing 1% linseed oil, echium oil, or fish oil from d 73 of gestation and during lactation (n = 16 per dietary treatment). Total oil concentrations in the diets were similar among dietary treatments. Blood samples were taken for fatty acid analysis and oxidative status of sows on d 73 and 93 of gestation and at parturition and the lightest and heaviest piglet per litter at birth and weaning. Colostrum was also sampled. No effect of diet was observed on total number of piglets born (13.7 ± 0.4), number of weaned piglets (10.8 ± 0.4), and gestation length (114.8 ± 0.2 d). Piglets from sows fed fish oil had lighter birth weights (1.41 ± 0.03 kg) than piglets from the linseed oil diet (1.54 ± 0.03 kg; P = 0.006), with no difference between the palm oil (1.45 ± 0.03 kg) and echium oil diet (1.49 ± 0.03 kg). Daily BW gain until weaning was less for piglets from sows fed the fish oil diet (214 ± 5 g) compared with piglets from sows fed the echium oil (240 ± 5 g; P oil diet (234 ± 5 g; P = 0.02). Compared with the palm oil diet, echium and linseed oil in the maternal diet increased the DHA concentration in the colostrum and the sow and piglet plasma to the same extent (1.1 to 1.4-fold; P oil diet, 20.7-fold, 10-fold, and 2.4-fold increases in DHA in colostrum, sow, and piglet plasma, respectively, were observed (P oil had, thus, no benefit over linseed oil and resulted in a twofold less DHA concentration in the plasma of piglets compared with fish

  6. Low temperature high density plasma nitriding of stainless steel molds for stamping of oxide glasses

    Directory of Open Access Journals (Sweden)

    Aizawa Tatsuhiko

    2016-01-01

    Full Text Available Various kinds of stainless steels have been widely utilized as a die for mold- and direct-stamping processes of optical oxide glasses. Since they suffered from high temperature transients and thermal cycles in practice, they must be surface-treated by dry and wet coatings, or, by plasma nitriding. Martensitic stainless steel mold was first wet plated by the nickel phosphate (NiP, which was unstable at the high temperature stamping condition; and, was easy to crystalize or to fracture by itself. This issue of nuisance significantly lowered the productivity in fabrication of optical oxide-glass elements. In the present paper, the stainless steel mold was surface-treated by the low-temperature plasma nitriding. The nitrided layer by this surface modification had higher nitrogen solute content than 4 mass%; the maximum solid-solubility of nitrogen is usually 0.1 mass% in the equilibrium phase diagram. Owing to this solid-solution with high nitrogen concentration, the nitrided layer had high hardness over 1400 HV within its thickness of 50 μm without any formation of nitrides after plasma nitriding at 693 K for 14.4 ks. This plasma-nitrided mold was utilized for mold-stamping of two colored oxide glass plates at 833 K; these plates were successfully deformed and joined into a single glass plate by this stamping without adhesion or galling of oxide glasses onto the nitrided mold surface.

  7. Evaluation of Residence Time on Nitrogen Oxides Removal in Non-Thermal Plasma Reactor

    OpenAIRE

    2015-01-01

    Non-thermal plasma (NTP) has been introduced over the last few years as a promising after- treatment system for nitrogen oxides and particulate matter removal from diesel exhaust. NTP technology has not been commercialised as yet, due to its high rate of energy consumption. Therefore, it is important to seek out new methods to improve NTP performance. Residence time is a crucial parameter in engine\\ud exhaust emissions treatment. In this paper, different electrode shapes are analysed and the ...

  8. Plasma-induced highly efficient synthesis of boron doped reduced graphene oxide for supercapacitors.

    Science.gov (United States)

    Li, Shaobo; Wang, Zhaofeng; Jiang, Hanmei; Zhang, Limei; Ren, Jingzheng; Zheng, Mingtao; Dong, Lichun; Sun, Luyi

    2016-09-21

    In this work, we presented a novel route to synthesize boron doped reduced graphene oxide (rGO) by using the dielectric barrier discharge (DBD) plasma technology under ambient conditions. The doping of boron (1.4 at%) led to a significant improvement in the capacitance of rGO and supercapacitors based on the as-synthesized B-rGO exhibited an outstanding specific capacitance.

  9. Laws of the oxidation of carbon isotopes in plasma processes under magnetic field

    Science.gov (United States)

    Myshkin, V. F.; Bespala, E. V.; Khan, V. A.; Makarevich, S. V.

    2016-06-01

    From law of quantum mechanics it follows that spin precession phase of unpaired electron in external magnetic field cannot be determined. It uncertainty necessary take into account in different physical and chemical processes. The expression of the rate constant of a chemical reaction based on the number of discrete spin states was obtained. The equations of chemical kinetics of plasma oxidation of carbon isotopes in the magnetic field were given.

  10. Toluene Oxidation by Non-Thermal Plasma Combined with Palladium Catalysts

    Directory of Open Access Journals (Sweden)

    Monica eMagureanu

    2013-06-01

    Full Text Available The oxidation of toluene in air was investigated using a dielectric barrier discharge (DBD combined with a Pd/Al2O3 catalyst. When using only plasma, rather low selectivity towards CO2 was obtained: 32-35%. By filling the DBD reactor with Pd/Al2O3 catalyst the CO2 selectivity was significantly enhanced (80-90%, however, a large amount of toluene was desorbed from the catalyst when the discharge was operated. By filling a quarter of the discharge gap with catalyst and placing the rest of the catalyst downstream of the plasma reactor, an important increase of CO2 selectivity (~75% and a 15% increase in toluene conversion were achieved as compared to the results with plasma alone. The catalyst exhibited a very good stability in this reaction.

  11. Levels of lipid peroxidation, nitric oxide, and antioxidant vitamins in plasma of patients with fibromyalgia.

    Science.gov (United States)

    Akkuş, Selami; Naziroğlu, Mustafa; Eriş, Sevilay; Yalman, Kadir; Yilmaz, Nigar; Yener, Mahmut

    2009-06-01

    The etiology of fibromyalgia is not clearly understood. In recent years, a few studies have investigated the possible role of reactive oxygen species (ROS) in the etiology and pathogenesis of fibromyalgia. The aim of this study was to investigate plasma antioxidant vitamins, lipid peroxidation (LP), and nitric oxide (NO) levels in patients with fibromyalgia and controls. The study was performed on the blood plasma of 30 female patients and 30 age-matched controls. After a fast of 12 h, blood samples were taken, and plasma samples were obtained for measurement of vitamins A, C, E, and beta-carotene concentrations and levels of LP and NO. Concentrations of vitamins A (p fibromyalgia than in controls, and LP levels were significantly (p vitamin C and beta-carotene and levels of NO did not change significantly. These results provide some evidence for a potential role of LP and fat-soluble antioxidants in the patients with fibromyalgia.

  12. Identification of the Oxidized Low-Density Lipoprotein Scavenger Receptor CD36 in Plasma

    DEFF Research Database (Denmark)

    Handberg, Aase; Levin, Klaus; Højlund, Kurt

    2006-01-01

    BACKGROUND: Macrophage CD36 scavenges oxidized low-density lipoprotein, leading to foam cell formation, and appears to be a key proatherogenic molecule. Increased expression of CD36 has been attributed to hyperglycemia and to defective macrophage insulin signaling in insulin resistance. Premature...... atherosclerosis is the major cause of morbidity and mortality in type 2 diabetes. Here, we report the identification of a soluble form of CD36 (sCD36) in plasma and hypothesize that sCD36 would be elevated in patients with type 2 diabetes and insulin resistance. METHODS AND RESULTS: sCD36 in plasma...... was demonstrated by immunopurification and Western blotting. We established ELISA assays to determine sCD36 in plasma and measured sCD36 in obese type 2 diabetic patients, obese nondiabetic relatives, and obese and lean control subjects. sCD36 was markedly elevated in type 2 diabetic patients compared with both...

  13. Plasma Deposition and Characterization of Copper-doped Cobalt Oxide Nanocatalysts

    Directory of Open Access Journals (Sweden)

    Jacek TYCZKOWSKI

    2013-09-01

    Full Text Available A series of pure and copper-doped cobalt oxide films was prepared by plasma-enhanced metalorganic chemical vapor deposition (PEMOCVD. The effect of Cu-doping on the chemical structure and morphology of the deposited films was investigated. Raman and FTIR spectroscopies were used to characterize the chemical structure and morphology of the produced films. The bulk composition and homogeneity of the samples were investigated by energy dispersive X-ray microanalysis (EDX, and X-ray photoelectron spectroscopy (XPS was employed to assess the surface chemical composition of pure and doped materials. The obtained results permit to affirm that the PEMOCVD technique is a simple, versatile and efficient method for providing homogeneous layers of cobalt oxides with a different content of copper. It has been found that pure cobalt oxide films mainly contain Co3O4 in the form of nanoclusters whereas the films doped with Cu are much more complex, and CoOx (also Co3O4, mixed Co-Cu oxides and CuOx nanoclusters are detected in them. Preliminary catalytical tests show that Cu-doped cobalt oxide films allow to initiate catalytic combustion of n-hexane at a lower temperature compared to the pure cobalt oxide (Co3O4 films. From what has been stated above, the plasma-deposited thin films of Cu-doped cobalt oxides pave the way towards a new class of nanomaterials with interesting catalytic properties. DOI: http://dx.doi.org/10.5755/j01.ms.19.3.2320

  14. Effect of oxidative stress on plasma membrane fluidity of THP-1 induced macrophages.

    Science.gov (United States)

    de la Haba, Carlos; Palacio, José R; Martínez, Paz; Morros, Antoni

    2013-02-01

    Plasma membrane is one of the preferential targets of reactive oxygen species which cause lipid peroxidation. This process modifies membrane properties such as membrane fluidity, a very important physical feature known to modulate membrane protein localization and function. The aim of this study is to evaluate the effect of oxidative stress on plasma membrane fluidity regionalization of single living THP-1 macrophages. These cells were oxidized with H(2)O(2) at different concentrations, and plasma membrane fluidity was analyzed by two-photon microscopy in combination with the environment-sensitive probe Laurdan. Results show a significant H(2)O(2) concentration dependent increase in the frequency of rigid lipid regions, mainly attributable to lipid rafts, at the expense of the intermediate fluidity regions. A novel statistical analysis evaluated changes in size and number of lipid raft domains under oxidative stress conditions, as lipid rafts are platforms aiding cell signaling and are thought to have relevant roles in macrophage functions. It is shown that H(2)O(2) causes an increase in the number, but not the size, of raft domains. As macrophages are highly resistant to H(2)O(2), these new raft domains might be involved in cell survival pathways.

  15. Oxidant-antioxidant status in the blood of horses with symptomatic recurrent airway obstruction (RAO).

    Science.gov (United States)

    Niedzwiedz, A; Jaworski, Z

    2014-01-01

    Systemic oxidative stress in horses with recurrent airway obstruction (RAO) is poorly characterized. The goal of this study was to investigate whether equine RAO is associated with systemic disturbances in the oxidant-antioxidant equilibrium. Seven healthy horses and 7 horses with symptomatic RAO. A prospective study. Healthy and RAO-affected horses were exposed to a 48-hour challenge with moldy hay and straw to induce clinical exacerbation of RAO. Venous blood was collected and the activities of the superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) in equine erythrocyte lysates were measured. The concentration of thiobarbituric acid-reactive substances (TBARSs) was assessed both in erythrocyte lysates and in plasma. A significant increase in the activities of GPx and SOD was detected in RAO-affected horses compared with the control animals. There was no significant difference between groups in terms of the erythrocyte lysate activities of CAT, GR, or TBARs or the plasma concentration of TBARs. Our results support the hypothesis that RAO in horses is associated with systemic oxidative stress. Future studies are needed to assess whether horses suffering from RAO can benefit from antioxidant supplementation. Copyright © 2014 by the American College of Veterinary Internal Medicine.

  16. Oxidant Status following Cardiac Surgery with Phosphorylcholine-Coated Extracorporeal Circulation Systems

    Science.gov (United States)

    Kaya, Ayşem

    2016-01-01

    Introduction. Extracorporeal circulation (ECC) related systemic oxidative stress is a well-known entity but the underlying mechanisms are not clearly described. Our aim was to investigate the relation between the oxidative stress indices, inflammatory markers, and phosphorylcholine-coated (PCC) ECC systems. Patients and Methods. Thirty-two consecutive coronary artery bypass grafting (CABG) cases were randomly assigned to Group I (PCC, n = 18) and Group II (noncoated, n = 14) ECC circuits. Total Antioxidant Status (TAS), Total Oxidant Status (TOS), Tumor Necrosis Factor-α (TNF-α), Interleukin-1β (IL-β), Interleukin-6 (IL-6), Interleukin-8 (IL-8), Interleukin-10 (IL-10), and Procalcitonin (PCT) levels were measured at 5 different time points. The association between the oxidative indices levels and PCC system used was analyzed. Results. In Group I TOS and TAS statuses were increased at T1, T2, T3, and T4, while IL-10 and TNF-α levels accompanied those raises only at T2 (Group I-Group II, 4.73 ± 2.04 versus 2.79 ± 0.63, p = 0.002, and 30.56 ± 8.11 versus 23.97 ± 7.8, p = 0.031, resp.). In contrast, mean TAS and TOS levels were similar to baseline at all time points in Group II but IL-6 and IL-8 levels were increased at T2 (Group I-Group II, 16.84 ± 5.63 versus 44.81 ± 17.0, p = 0.001, and 38.88 ± 9.8 versus 46.14 ± 9.25, p = 0.038, resp.). Conclusion. Even coated ECC systems are still incapable of attenuating the inflammatory response to cardiopulmonary bypass (CPB). PMID:27994711

  17. Arginines Plasma Concentration and Oxidative Stress in Mild to Moderate COPD

    Science.gov (United States)

    Zinellu, Angelo; Fois, Alessandro Giuseppe; Sotgia, Salvatore; Sotgiu, Elisabetta; Zinellu, Elisabetta; Bifulco, Fabiana; Mangoni, Arduino A; Pirina, Pietro; Carru, Ciriaco

    2016-01-01

    Background Elevated plasma concentrations of the endogenous nitric oxide synthase (NOS) inhibitor asymmetric dimethylarginine (ADMA) have been observed in respiratory conditions such as asthma and cystic fibrosis. Since oxidative stress has been shown to increase the activity of arginine methylating enzymes, hence increased ADMA synthesis, and to reduce ADMA degrading enzymes, hence increased ADMA concentrations, we assessed methylated arginines concentrations in chronic obstructive pulmonary disease (COPD), a disease characterized by increased oxidative stress. Methods Plasma arginine, ADMA and symmetric dimethylarginine (SDMA), oxidative stress markers (thiobarbituric acid reactive substances, TBARS, and plasma proteins SH, PSH) and antioxidants (taurine and paraoxonase 1, PON1, activity) were measured in 43 COPD patients with mild (n = 29) or moderate (n = 14) disease and 43 age- and sex-matched controls. Results TBARS significantly increased with COPD presence and severity (median 2.93 vs 3.18 vs 3.64 μmol/L, respectively in controls, mild and moderate group, p<0.0001 by ANOVA) whereas PSH decreased (6.69±1.15 vs 6.04±0.85 vs 5.33±0.96 μmol/gr prot, p<0.0001 by ANOVA). Increased ADMA/arginine ratio, primarily due to reduced arginine concentrations, was also observed with COPD presence and severity (median 0.0067 vs 0.0075 vs 0.0100, p<0.0001 by ANOVA). In multiple logistic regression analysis, only TBARS (OR 0.44, 95% CI 0.25–0.77; p = 0.0045) and ADMA/Arginine ratio (OR 1.72, 95% CI 2.27–13.05; p = 0.02) were independently associated with COPD severity. Conclusion COPD presence and severity are associated with increased oxidative stress and alterations in arginine metabolism. The reduced arginine concentrations in COPD may offer a new target for therapeutic interventions increasing arginine availability. PMID:27479314

  18. Analysis of oxidative stress status, catalase and catechol-O-methyltransferase polymorphisms in Egyptian vitiligo patients.

    Directory of Open Access Journals (Sweden)

    Dina A Mehaney

    Full Text Available Vitiligo is the most common depigmentation disorder of the skin. Oxidative stress is implicated as one of the probable events involved in vitiligo pathogenesis possibly contributing to melanocyte destruction. Evidence indicates that certain genes including those involved in oxidative stress and melanin synthesis are crucial for development of vitiligo. This study evaluates the oxidative stress status, the role of catalase (CAT and catechol-O-Methyltransferase (COMT gene polymorphisms in the etiology of generalized vitiligo in Egyptians. Total antioxidant capacity (TAC and malondialdehyde (MDA levels as well as CAT exon 9 T/C and COMT 158 G/A polymorphisms were determined in 89 patients and 90 age and sex-matched controls. Our results showed significantly lower TAC along with higher MDA levels in vitiligo patients compared with controls. Meanwhile, genotype and allele distributions of CAT and COMT polymorphisms in cases were not significantly different from those of controls. Moreover, we found no association between both polymorphisms and vitiligo susceptibility. In conclusion, the enhanced oxidative stress with the lack of association between CAT and COMT polymorphisms and susceptibility to vitiligo in our patients suggest that mutations in other genes related to the oxidative pathway might contribute to the etiology of generalized vitiligo in Egyptian population.

  19. Production of hydroxyapatite layers on the plasma electrolytically oxidized surface of titanium alloys.

    Science.gov (United States)

    Lugovskoy, Alex; Lugovskoy, Svetlana

    2014-10-01

    Hydroxyapatite (HA) is a bioactive material that is widely used for improving the osseointegration of titanium dental implants. Titanium can be coated with HA by various methods, such as chemical vapor deposition (CVD), thermal spray, or plasma spray. HA coatings can also be grown on titanium surfaces by hydrothermal, chemical, and electrochemical methods. Plasma electrolytic oxidation (PEO), or microarc oxidation (MAO), is an electrochemical method that enables the production of a thick porous oxide layer on the surface of a titanium implant. If the electrolyte in which PEO is performed contains calcium and phosphate ions, the oxide layer produced may contain hydroxyapatite. The HA content can then be increased by subsequent hydrothermal treatment. The HA thus produced on titanium surfaces has attractive properties, such as a high porosity, a controllable thickness, and a considerable density, which favor its use in dental and bone surgery. This review summarizes the state of the art and possible further development of PEO for the production of HA on Ti implants.

  20. Isothermal Oxidation Behavior of Supersonic Atmospheric Plasma-Sprayed Thermal Barrier Coating System

    Science.gov (United States)

    Bai, Yu; Ding, Chunhua; Li, Hongqiang; Han, Zhihai; Ding, Bingjun; Wang, Tiejun; Yu, Lie

    2013-10-01

    In this work, Y2O3 stabilized zirconia-based thermal barrier coatings (TBCs) were deposited by conventional atmospheric plasma spraying (APS) and high efficiency supersonic atmospheric plasma spraying (SAPS), respectively. The effect of Al2O3 layer stability on the isothermal growth behavior of thermally grown oxides (TGOs) was studied. The results revealed that the Al2O3 layer experienced a three-stage change process, i.e., (1) instantaneous growth stage, (2) steady-state growth stage, and (3) depletion stage. The thickness of Al2O3 scale was proved to be an important factor for the growth rate of TGOs. The SAPS-TBCs exhibited a higher Al2O3 stability and better oxidation resistance as compared with the APS-TBCs. Additionally, it was found that inner oxides, especially nucleated on the top of the crest, continually grew and swallowed the previously formed Al2O3 layer, leading to the granulation and disappearance of continuous Al2O3 scale, which was finally replaced by the mixed oxides and spinel.

  1. Cyclic oxidation behavior of plasma surface chromising coating on titanium alloy Ti-6Al-4V

    Energy Technology Data Exchange (ETDEWEB)

    Wei Dongbo, E-mail: weidb1982@163.com [College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211100 (China); Zhang Pingze; Yao Zhengjun; Zhou Jintang; Wei Xiangfei; Zhou Peng [College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211100 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer A chromising coating in gradient distribution was obtained on Ti-6Al-4V titanium alloy. Black-Right-Pointing-Pointer The cyclic oxidation behavior of chromising coating was studied at 650-850 Degree-Sign C. Black-Right-Pointing-Pointer The Ti-Cr mutual diffusion layer changed into the Ti(Cr, Al){sub 2} laves phase layer, which prevented the inward diffusion of oxygen. Black-Right-Pointing-Pointer A multi-layers structure of Cr{sub 2}O{sub 3}, TiO{sub 2} and Al{sub 2}O{sub 3} formed during oxidation. Black-Right-Pointing-Pointer Ti, Al diffused toward the oxide-gas interface, Cr diffused predominantly outward. - Abstract: The cyclic oxidation behavior of plasma surface chromising coating on titanium alloy (Ti-6Al-4V) was researched in air at 650 Degree-Sign C, 750 Degree-Sign C and 850 Degree-Sign C. A NiCrAlY coating was prepared by multi-arc ion plating as a comparison. The surface morphologies, microstructures and phases of both coatings before and after oxidation were investigated using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffractometry (XRD). The results show that the chromising coating consisted of an outer layer of loose Cr deposition, an intermediate layer of compact Cr deposition and an inner Ti-Cr mutual diffusion layer. The multilayer oxide scales formed in the oxidation process, which has the better cyclic oxidation resistance compared with NiCrAlY thermal barrier coating. However, the brittleness of Ti(Cr, Al){sub 2} laves phase resulted in spallation of oxide scales at 750 Degree-Sign C and 850 Degree-Sign C.

  2. Hematological, oxidative stress, and immune status profiling in elite combat sport athletes.

    Science.gov (United States)

    Dopsaj, Violeta; Martinovic, Jelena; Dopsaj, Milivoj; Kasum, Goran; Kotur-Stevuljevic, Jelena; Koropanovski, Nenad

    2013-12-01

    The aim of this study was to profile hematological, oxidative stress, and immunological parameters in male athletes who practiced combat sports and to determine whether the type of combat sport influenced the measured parameters. Eighteen karate professionals, 15 wrestlers, and 14 kickboxers participated in the study. Hematological, iron-related, oxidative stress, and immunological parameters were measured at the beginning of a precompetitive period. The general linear model showed significant differences between the karate professionals, wrestlers, and kickboxers with respect to their hematological and iron status parameters (Wilks' Lambda = 0.270, F = 2.186, p < 0.05) and oxidative stress status (Wilks' Lambda = 0.529, F = 1.940, p < 0.05). The immature reticulocyte fraction was significantly higher in wrestlers (0.30 ± 0.03) compared with kickboxers (0.24 ± 0.04; p < 0.05) and karate professionals (0.26 ± 0.04; p < 0.05). Low hemoglobin density was significantly lower in wrestlers and kickboxers (p < 0.05) compared with karate professionals (karate: 3.51 ± 1.19, wrestlers: 1.95 ± 1.10, and kickboxers: 1.77 ± 0.76). Significant differences were observed between the karate professionals and wrestlers with respect to their pro-oxidant-antioxidant balance (437 ± 103 vs. 323 ± 148, p < 0.05) and superoxide-dismutase activity (SOD) (73 ± 37 vs. 103 ± 30, p < 0.05). All the measured parameters (with the exception of SOD activity) fell within their physiological ranges, indicating that the study participants represented a young and healthy male population. Hematological parameters differed between kickboxers and karate professionals. The low pro-oxidant-antioxidant balance and high SOD activity in wrestlers could be associated with the long-term impact of wrestling as a type of strenuous exercise.

  3. Influence of calcitriol treatment on nutritional status, inflammation and oxidative stress of patients undergoing maintenance hemodialysis

    Institute of Scientific and Technical Information of China (English)

    Lin-Fang Zhang; Hong-Li Yan; Xin Chen

    2015-01-01

    Objective:To analyze influences of calcitriol treatment on nutritional status, inflammation and oxidative stress of patients undergoing maintenance hemodialysis.Methods:A total of 132 patients undergoing maintenance hemodialysis in our hospital were enrolled and randomly divided into observation group and control group. The observation group (n=66 cases) underwent calcitriol treatment, while control group (n=66 cases) underwent routine treatment. Nutrition status, micro inflammation and oxidative stress of the two groups were compared. Results: (1) After treatment, patients’ TSF, MAC, AMC, Hb levels of the observation group were higher than that of the control group (P<0.05); (2) After treatment, TGF-beta 1, CTGF levels of the observation group was significantly lower than that of the control group (P<0.05), but BMP-7 level was higher than control group (P<0.05). (3) Patients’ MPO, CAT, NO, TAC levels of the observation group were higher than control group (P<0.05).Conclusion:For patients with maintenance hemodialysis, Calcitriol can optimize patients' nutritional status, reduce systemic inflammatory response, enhance antioxidant capacity.

  4. Dynamics of cathode spots in low-pressure arc plasma removing oxide layer on steel surfaces

    Science.gov (United States)

    Tang, Z. L.; Yang, K.; Liu, H. X.; Zhang, Y. C.; Li, H.; Zhu, X. D.

    2016-03-01

    The dynamics of cathode spots has been investigated in low-pressure arc plasma for removing oxide layer on low carbon steel surfaces. The motion of cathode spots was observed with a high speed camera, and the arc voltage was analyzed by fast Fourier transform. The spots move on clean steel surface as a random walk, and the low-frequency components dominated the voltage waveform. However, the spots on steel surfaces with oxide layer tend to burn on the rim of the eroded area formed in the previous arcing, and the low-frequency components decrease correspondingly. The "color" of the colored random noise for arc voltage varies from the approximate brown noise for clean steel surface to pink noise for thick oxide layer, where the edge effect of boundary is considered to play a significant role.

  5. Characterization of ultrathin SiO 2/Si interface grown by low temperature plasma oxidation

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Ultrathin SiO 2 layers on Si (100) wafers were prepared by plasma oxidation at a low temperature (250℃). The analyses of X-ray photoelectron spectroscopy (XPS) and TEM reveal that the chemical composition of the oxide layer is stoichiometric SiO 2 and the SiO 2/Si interface is abrupt. The thickness of the ultrathin oxide layer obtained from XPS, capacitance-voltage (C-V) and ellipsometry measurements indicate a nonlinear time dependence. The high frequency C-V characterization of MOS structure shows that the fixed charge density in SiO 2 film is about 10 11 cm -2 . It is also shown that the strength of breakdown electrical field of SiO 2 film with 6 nm thickness is of the order of 10 6 Vcm -1 . These properties of the ultrathin SiO 2 layer ensure its application in silicon quantum devices.

  6. Formation of a Spinel Coating on AZ31 Magnesium Alloy by Plasma Electrolytic Oxidation

    Science.gov (United States)

    Sieber, Maximilian; Simchen, Frank; Scharf, Ingolf; Lampke, Thomas

    2016-03-01

    Plasma electrolytic oxidation (PEO) is a common means for the surface modification of light metals. However, PEO of magnesium substrates in dilute electrolytes generally leads to the formation of coatings consisting of unfavorable MgO magnesium oxide. By incorporation of electrolyte components, the phase constitution of the oxide coatings can be modified. Coatings consisting exclusively of MgAl2O4 magnesium-aluminum spinel are produced by PEO in an electrolyte containing hydroxide, aluminate, and phosphate anions. The hardness of the coatings is 3.5 GPa on Martens scale on average. Compared to the bare substrate, the coatings reduce the corrosion current density in dilute sodium chloride solution by approx. one order of magnitude and slightly shift the corrosion potential toward more noble values.

  7. Analysis of a gas-liquid film plasma reactor for organic compound oxidation.

    Science.gov (United States)

    Hsieh, Kevin; Wang, Huijuan; Locke, Bruce R

    2016-11-01

    A pulsed electrical discharge plasma formed in a tubular reactor with flowing argon carrier gas and a liquid water film was analyzed using methylene blue as a liquid phase hydroxyl radical scavenger and simultaneous measurements of hydrogen peroxide formation. The effects of liquid flow rate, liquid conductivity, concentration of dye, and the addition of ferrous ion on dye decoloration and degradation were determined. Higher liquid flow rates and concentrations of dye resulted in less decoloration percentages and hydrogen peroxide formation due to initial liquid conductivity effects and lower residence times in the reactor. The highest decoloration energy yield of dye found in these studies was 5.2g/kWh when using the higher liquid flow rate and adding the catalyst. The non-homogeneous nature of the plasma discharge favors the production of hydrogen peroxide in the plasma-liquid interface over the chemical oxidation of the organic in the bulk liquid phase and post-plasma reactions with the Fenton catalyst lead to complete utilization of the plasma-formed hydrogen peroxide.

  8. Simultaneous Oxidization of NOx and 802 by a New Non-thermal Plasma Reactor Enhanced by Catalyst and Additive

    Institute of Scientific and Technical Information of China (English)

    Heejoon KIM; HAN Jun; Yuhei SAKAGUCHI; Wataru MINAMI

    2008-01-01

    The non-thermal plasma as one of the most promising technologies for removing NOx and SO2 has attracted much attention. In this study, a new plasma reactor combined with catalyst and additive was developed to effectively oxidize and remove NOx and SO2 in the flue gas. The experimental results showed that TiO2 could improve the oxidation efficiency of SO2 in the case of applying plasma while having a negative effect on the oxidation process of NO and NOx. With the addition of NH3, the oxidation rates of NOx, NO and SO2 were slightly increased. However, the effect of adding NH3 on NOx oxidation was negative when the temperature was above 200℃.

  9. Plasma oxidative stress parameters in men and women with early stage Alzheimer type dementia.

    Science.gov (United States)

    Puertas, M C; Martínez-Martos, J M; Cobo, M P; Carrera, M P; Mayas, M D; Ramírez-Expósito, M J

    2012-08-01

    It is well known that oxidative stress is one of the earliest events in Alzheimer's disease pathogenesis, indicating that may play a key role in this disease. In our study, we measured the levels of oxidative stress indicators (TBARS and protein carbonyls content) and the non-enzymatic (glutathione (GSH) and oxidized glutathione (GSSG)) and enzymatic (glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD)) defense systems in the plasma of 46 patients diagnosed of ATD and 46 age-matched controls. We found decreased levels in total GSH in ATD patients, although healthy control women showed lower levels of total GSH than healthy control men. On the contrary, we found increased levels of TBARS and carbonyl groups content in ATD patients in both genders. The activity of the plasma antioxidant enzymes showed no changes for SOD activity in ATD patients, independently of the gender, although western blot analysis showed an increase in SOD-1 protein. CAT activity was also decreased in ATD patients, although this decrease is mainly due to the decrease found in men but not in women. However, western blot analysis did not show differences in CAT protein between controls and ATD patients. Finally, a decrease of GPx activity was found in ATD patients in both genders. However, as with CAT protein, western blot analysis did not show differences in GPx protein between controls and ATD patients. Our results suggest that there is a defect in the antioxidant defense system that is incapable of responding to increased free radical production, which may lead to oxidative damage and the development of the pathological alterations that characterize the neurodegenerative disorder of patients with ATD. Thus, oxidative damage could be one important aspect for the onset of ATD and oxidative stress markers could be useful to diagnose the illness in their earliest stages through both non-invasive, reliable and cost-affordable methods.

  10. Effects of Melissa officinalis L. on oxidative status and DNA damage in subjects exposed to long-term low-dose ionizing radiation.

    Science.gov (United States)

    Zeraatpishe, Akbar; Oryan, Shahrbano; Bagheri, Mohammad Hadi; Pilevarian, Ali Asghar; Malekirad, Ali Akbar; Baeeri, Maryam; Abdollahi, Mohammad

    2011-04-01

    The aim of this study was to determine the capability of Melissa officinalis L. (Lemon balm) infusion on improvement of oxidative stress status in radiology staff that were exposed to persistent low-dose radiation during work. The study was a before-after clinical trial performed on 55 radiology staff. They were asked to drink Lemon balm infusion which was prepared like a tea bag twice daily (1.5 g/100 mL) for 30 days. In the plasma, lipid peroxidation, DNA damage, catalase, superoxide dismutase, myeloperoxidase, and glutathione peroxidase activity were measured before and after using Lemon balm infusion.Use of Lemon balm infusion in radiology unit workers resulted in a significant improvement in plasma levels of catalase, superoxide dismutase, and glutathione peroxidase and a marked reduction in plasma DNA damage, myeloperoxidase, and lipid peroxidation. It is concluded that infusion of Lemon balm markedly improve oxidative stress condition and DNA damage in radiology staff when used as a dietary supplement for radiation protection.

  11. Weight reduction and the impaired plasma-derived free fatty acid oxidation in type 2 diabetic subjects

    NARCIS (Netherlands)

    Blaak, EE; Wolffenbuttel, BHR; Saris, WHM; Pelsers, MMAL; Wagenmakers, AJM

    2001-01-01

    In a previous study the oxidation of plasma free fatty acids (FFA) under baseline conditions and during exercise was lower in type 2 diabetic subjects compared with weight-matched controls. The present study intended to investigate the effect of weight reduction (very low calorie diet) on plasma FFA

  12. Weight reduction and the impaired plasma-derived free fatty acid oxidation in type 2 diabetic subjects

    NARCIS (Netherlands)

    Blaak, EE; Wolffenbuttel, BHR; Saris, WHM; Pelsers, MMAL; Wagenmakers, AJM

    2001-01-01

    In a previous study the oxidation of plasma free fatty acids (FFA) under baseline conditions and during exercise was lower in type 2 diabetic subjects compared with weight-matched controls. The present study intended to investigate the effect of weight reduction (very low calorie diet) on plasma FFA

  13. Plasma membrane Ca2+-ATPases:Targets of oxidative stress in brain aging and neurodegeneration

    Institute of Scientific and Technical Information of China (English)

    Asma; Zaidi

    2010-01-01

    The plasma membrane Ca2+-ATPase(PMCA)pumps play an important role in the maintenance of precise levels of intracellular Ca2+[Ca2+]i,essential to the functioning of neurons.In this article,we review evidence showing age-related changes of the PMCAs in synaptic plasma membranes(SPMs).PMCA activity and protein levels in SPMs diminish progressively with increasing age. The PMCAs are very sensitive to oxidative stress and undergo functional and structural changes when exposed to oxidants of physiological relevance.The major signatures of oxidative modification in the PMCAs are rapid inactivation,conformational changes,aggregation, internalization from the plasma membrane and proteolytic degradation.PMCA proteolysis appears to be mediated by both calpains and caspases.The predominance of one proteolytic pathway vs the other,the ensuing pattern of PMCA degradation and its consequence on pump activity depends largely on the type of insult,its intensity and duration.Experimental reduction of PMCA expression not only alters the dynamics of cellular Ca2+ handling but also has a myriad of downstream conse-quences on various aspects of cell function,indicating a broad role of these pumps.Age-and oxidation-related down-regulation of the PMCAs may play an important role in compromised neuronal function in the aging brain and its several-fold increased susceptibility to neurodegenerative disorders such as Alzheimer’s disease, Parkinson’s disease,and stroke.Therapeutic approaches that protect the PMCAs and stabilize[Ca2+]i homeostasis may be capable of slowing and/or preventing neuronal degeneration.The PMCAs are therefore emerging as a new class of drug targets for therapeutic interventions in various chronic degenerative disorders.

  14. Assessment of fetal antioxidant and oxidant status during different anesthesia techniques for elective cesarean sections

    Directory of Open Access Journals (Sweden)

    Safinaz Karabayirli

    2015-01-01

    Full Text Available Background: We aimed to investigate the effects of general, spinal and epidural anesthesia on fetal total antioxidant status (TAS and total oxidant status (TOS, and oxidative stress index (OSI during elective cesarean section in this study. Materials and Methods: Forty-seven parturients scheduled for elective cesarean section were randomly allocated into three groups: Group spinal (n = 15, group epidural (n = 17, and group general (n = 15, This prospective randomized study was performed in Faculty of Medicine, Turgut Ozal University, Turkey. After the baby was delivered; TAS, TOS levels, and arterial blood gases parameters were analyzed in an umbilical arterial blood sample. OSI values are calculated by a ratio of TOS to the TAS. Results: The levels of TAS and TOS in umbilical arterial blood sample were not statistically different among three. However, OSI values were significantly different among the three groups (P = 0.042. Median OSI values is 24 (interquartile range [IQR], 2-37 in group spinal, 19 (IQR, 4-44 in group epidural, and 8 (IQR, 4-36 in group general. There was no significant difference in OSI values in the comparison of group spinal with group general and group epidural, but it was significantly lower in group general when compared with group epidural with Bonferroni correction (P = 0.017. Umbilical cord arterial blood gas values (pH, PaCO 2 , PaO 2 , SaO 2 , HCO 3 , and CtO 2 , glucose, lactate, and hemoglobin levels were similar in three groups. Conclusion: General anesthesia may be more favorable than epidural in those undergoing cesarean section when fetal oxidative status gains importance.

  15. Combined in situ PM-IRRAS/QCM studies of water adsorption on plasma modified aluminum oxide/aluminum substrates

    Science.gov (United States)

    Giner, Ignacio; Maxisch, Michael; Kunze, Christian; Grundmeier, Guido

    2013-10-01

    Water adsorption on plasma modified oxyhydroxide covered aluminum surfaces was analyzed by means of a set-up combining in situ photoelastic modulated infrared reflection absorption spectroscopy (PM-IRRAS) and quartz crystal microbalance (QCM) in a low-temperature plasma cell. The chemical structure of the surface before and after the plasma treatment was moreover characterized by means of X-ray photoelectron spectroscopy (XPS) analysis. The surface chemistry of oxide covered aluminum was modified by oxidative and reductive low-temperature plasma pre-treatments. The Ar-plasma treatment reduced the surface hydroxyl density and effectively removed adsorbed organic contaminations. Surface modification by means of a water plasma treatment led to an increased surface hydroxyl density as well as an increase of the thickness of the native oxide film. The adsorption of water at atmospheric pressures on plasma modified aluminum surfaces led to a superimposition of reversible water layer adsorption and a simultaneous increase of the oxyhydroxide film thickness as a result of a chemisorption process. The amount of physisorbed water increased with the surface hydroxyl density whereas the chemisorption process was most significant for the surface after Ar-plasma treatment and almost negligible for the already water plasma treated surface.

  16. Microstructural evolution and growth kinetics of thermally grown oxides in plasma sprayed thermal barrier coatings

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    Xiaoju Liu

    2016-02-01

    Full Text Available The formation of thermally grown oxide (TGO during high temperature is a key factor to the degradation of thermal barrier coatings (TBCs applied on hot section components. In the present study both the CoNiCrAlY bond coat and ZrO2-8 wt.% Y2O3 (8YSZ ceramic coat of TBCs were prepared by air plasma spraying (APS. The composition and microstructure of TGO in TBCs were investigated using scanning electron microscopy (SEM, energy dispersive spectroscopy (EDS and X-ray diffraction (XRD analysis. The growth rate of TGO for TBC and pure BC were gained after isothermal oxidation at 1100 °C for various times. The results showed that as-sprayed bond coat consisted of β and γ/γ′phases, β phase reducesd as the oxidation time increased. The TGO comprised α-Al2O3 formed in the first 2 h. CoO, NiO, Cr2O3 and spinel oxides appeared after 20 h of oxidation. Contents of CoO and NiO reduced while that of Cr2O3 and spinel oxides increased in the later oxidation stage. The TGO eventually consisted of a sub-Al2O3 layer with columnar microstructure and the upper porous CS clusters. The TGO growth kinetics for two kinds of samples followed parabolic laws, with oxidation rate constant of 0.344 μm/h0.5 for TBCs and 0.354 μm/h0.5 for pure BCs.

  17. Microstructural evolution and growth kinetics of thermally grown oxides in plasma sprayed thermal barrier coatings

    Institute of Scientific and Technical Information of China (English)

    Xiaoju Liu; Teng Wang; Caicai Li; Zhenhuan Zheng; Qiang Li

    2016-01-01

    The formation of thermally grown oxide (TGO) during high temperature is a key factor to the degradation of thermal barrier coatings (TBCs) applied on hot section components. In the present study both the CoNiCrAlY bond coat and ZrO2-8 wt.% Y2O3 (8YSZ) ceramic coat of TBCs were prepared by air plasma spraying (APS). The composition and microstructure of TGO in TBCs were investigated using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analysis. The growth rate of TGO for TBC and pure BC were gained after isothermal oxidation at 1100 °C for various times. The results showed that as-sprayed bond coat consisted of β and γ/γ'phases,β phase reducesd as the oxidation time increased. The TGO comprised α-Al2O3 formed in the first 2 h. CoO, NiO, Cr2O3 and spinel oxides appeared after 20 h of oxidation. Contents of CoO and NiO reduced while that of Cr2O3 and spinel oxides increased in the later oxidation stage. The TGO eventually consisted of a sub-Al2O3 layer with columnar microstructure and the upper porous CS clusters. The TGO growth kinetics for two kinds of samples followed parabolic laws, with oxidation rate constant of 0.344 μm/h0.5 for TBCs and 0.354 μm/h0.5 for pure BCs.

  18. Growth performance and oxidative status in piglets supplemented with verbascoside and teupolioside

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    G. Pastorelli

    2010-04-01

    Full Text Available Two hundred forty piglets, half female and half barrows, 8.1 ± 1.40 kg LW, were divided into 6 experimental groups and fed ad libitum with a diet supplemented with the following levels of antioxidants: 0 (CON + = positive control added with 100 mg lincomicine/kg, 5 (LT = low teupolioside or LV = low verbascoside, 10 (HT = high teupolioside; HV = high verbascoside; LT+LV mg/kg of diet for 56 days. Body weight and feed intake were recorded on d0, 14 and 56 of the trial. Ten piglets from each group were selected and blood collected by anterior vena cava puncture at 0, 14 and 56 d for reactive oxygen metabolite (ROMs determination. HV showed final weight higher than the other groups (P<0.05, and oxidative stability was improved by both integrations of verbascoside. These results support the view that Verbascoside influences the growth performances and oxidative status of piglets.

  19. The influence of vitamin E supplementation on the oxidative status of rat liver

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    Đurašević S.F.

    2010-01-01

    Full Text Available We tested to see if the additional intake of vitamin E in the form of α-tocopheryl-succinate would improve liver antioxidative protection. Thus, we studied the tissue oxidative status in rats supplemented by two doses of the antioxidant over a four week period of time. Our results confirmed that the additional intake of vitamin E decreased the liver lipid peroxidation level and SOD activity level and preserved its vitamin C content. However, the hydrogen peroxide content and catalase activity remained unchanged, probably due to the mechanism of vitamin E liver metabolism. .

  20. Changes in oxidative status of the heart in rats receiving vitamin C supplements

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    Đurašević S.F.

    2007-01-01

    Full Text Available We studied the oxidative status of the heart in rats receiving by two doses of vitamin C over a period of four weeks. The activities of copper zinc superoxide dismutase (CuZnSOD, manganese superoxide dismutase (MnSOD, and catalase, hydrogen peroxide concentration, the level of lipid peroxidation, and total vitamin C content were determined in the heart of the experimental animals, as well as the concentration of vitamin C in their serum. Our results indicate that, apart from the ability of rats to synthesize vitamin C, supplementation leads to additional antioxidative protection.

  1. Tocotrienol rich fraction supplementation improved lipid profile and oxidative status in healthy older adults: A randomized controlled study

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    Mohd Yusof Yasmin Anum

    2011-06-01

    Full Text Available Abstract Background Vitamin E supplements containing tocotrienols are now being recommended for optimum health but its effects are scarcely known. The objective was to determine the effects of Tocotrienol Rich Fraction (TRF supplementation on lipid profile and oxidative status in healthy older individuals at a dose of 160 mg/day for 6 months. Methods Sixty-two subjects were recruited from two age groups: 35-49 years (n = 31 and above 50 years (n = 31, and randomly assigned to receive either TRF or placebo capsules for six months. Blood samples were obtained at 0, 3rd and 6th months. Results HDL-cholesterol in the TRF-supplemented group was elevated after 6 months (p 50 year-old group (p 50 year-old group after receiving 6 months of TRF supplementation. Changes in enzyme activities were only observed in the > 50 year-old group. SOD activity was decreased after 3 (p Conclusion The observed improvement of plasma cholesterol, AGE and antioxidant vitamin levels as well as the reduced protein damage may indicate a restoration of redox balance after TRF supplementation, particularly in individuals over 50 years of age.

  2. Antioxidant status, lipid peroxidation and nitric oxide in fibromyalgia: etiologic and therapeutic concerns.

    Science.gov (United States)

    Ozgocmen, Salih; Ozyurt, Huseyin; Sogut, Sadik; Akyol, Omer; Ardicoglu, Ozge; Yildizhan, Hulya

    2006-05-01

    We proposed to assess the oxidant/antioxidant status, lipid peroxidation and nitric oxide (NO) in untreated fibromyalgia (FM) patients and controls. The effect of amitriptyline (A, 20 mg daily) and sertraline (S, 100 mg daily) treatment on patients' superoxide dismutase (SOD), xanthine oxidase (XO), adenosine deaminase (ADA) enzyme activities, thiobarbituric acid reactive substances (TBARS) and NO levels was investigated. Thirty female patients with primary FM and age-matched 16 healthy female controls were included. Patients received an 8-week course of treatment with either A or S. FM patients had higher serum levels of TBARS (particularly malondialdehyde) and lower levels of nitrite compared to controls whereas enzyme activities were similar. A and S significantly improved Fibromyalgia Impact Questionnaire (FIQ) pain scores, Hamilton anxiety and depression rating scales. But neither A nor S had significant effects on measured oxidative stress parameters, except SOD activity that was significantly reduced after S treatment. Total myalgic scores negatively correlated with XO activity, and depression scales negatively correlated with levels of TBARS. Our results indicate that patients with FM are under oxidative stress. These findings represent a rationale for further research assessing the effect of free radical scavengers or antioxidant agents like vitamins and omega-3 fatty acids on peripheral and central mechanisms in FM.

  3. Coenzyme Q10 and Oxidative Stress: Inflammation Status in Hepatocellular Carcinoma Patients after Surgery

    Science.gov (United States)

    Liu, Hsiao-Tien; Cheng, Shao-Bin; Huang, Yi-Chia; Huang, Yin-Tzu; Lin, Ping-Ting

    2017-01-01

    (1) Background: Hepatocellular carcinoma (HCC) is the second leading cause of cancer deaths worldwide, and surgical resection is the main treatment for HCC. To date, no published study has examined the status of coenzyme Q10 in patients with HCC after surgery. Thus, the purpose of this study was to investigate the correlations between the level of coenzyme Q10, oxidative stress, and inflammation in patients with HCC after surgery; (2) Methods: 71 primary HCC patients were recruited. Levels of coenzyme Q10, vitamin E, oxidative stress (malondialdehyde), antioxidant enzymes activity (superoxidase dismutase, catalase, and glutathione peroxidase), and inflammatory markers (high sensitivity C-reactive protein; tumor necrosis factor-α; and interleukin-6) were measured; (3) Results: Patients with HCC had a significantly lower levels of coenzyme Q10 (p = 0.01) and oxidative stress (p < 0.01), and significantly higher levels of antioxidant enzymes activities and inflammation after surgery (p < 0.05). The level of coenzyme Q10 was significantly positively correlated with antioxidant capacity (vitamin E and glutathione peroxidase activity) and negatively correlated with inflammation markers after surgery; (4) Conclusion: Hepatocarcinogenesis is associated with oxidative stress, and coenzyme Q10 may be considered an antioxidant therapy for patients with HCC, particularly those with higher inflammation after surgery. PMID:28054958

  4. Acute phase response and oxidative stress status in familial Mediterranean fever (FMF).

    Science.gov (United States)

    Guzel, Savas; Andican, Gulnur; Seven, Arzu; Aslan, Mahmure; Bolayirli, Murat; Guzel, Eda Celik; Hamuryudan, Vedat

    2012-06-01

    We aimed to determine acute phase response (APR) and oxidative stress in patients with familial Mediterranean fever (FMF) and compare these characteristics with those in healthy controls; 20 patients with FMF and 15 healthy controls were enrolled in the study. The erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), fibrinogen, and leukocyte levels were determined as markers of APR. Thiobarbituric acid reactive substances (TBARS), conjugated diene, and lipid hydroperoxide levels were measured as markers of lipid peroxidation. Carbonyl group and thiol (T-SH) levels were analyzed to determine the oxidative damage to proteins, and 8-hydroxy-2-deoxyguanosine (8-OHdG) was measured to reflect DNA oxidation. The erythrocyte glutathione (GSH) level, and glutathione peroxidase (GSH-Px), CuZn superoxide dismutase (CuZn SOD), and catalase activities were measured as markers of antioxidant status. Conjugated diene (p FMF patients compared with controls. FMF patients in the attack period (n = 8) had significantly higher CRP, ESR, fibrinogen, and leukocyte levels (p FMF patients in the attack period. The findings revealed upregulated APR during the attack period in FMF patients and enhanced oxidative stress in the FMF patients as compared to controls.

  5. Atmospheric pressure plasma jet-synthesized electrochromic organomolybdenum oxide thin films for flexible electrochromic devices

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yung-Sen, E-mail: yslin@fcu.edu.tw; Tsai, Tsung-Hsien; Tien, Shih-Wei

    2013-02-01

    An investigation is conducted into fast synthesis of electrochromic organomolybdenum oxide (MoO{sub x}C{sub y}) thin films onto 40 Ω/□ flexible polyethylene terephthalate/indium tin oxide substrates via atmospheric pressure plasma jet. A precursor [molybdenum carbonyl, Mo(CO){sub 6}] vapor, carried by argon gas, is injected into air plasma torch to synthesize MoO{sub x}C{sub y} films for offering extraordinary electrochromic performance. Only low driving voltages from − 1 V to 1 V are needed to offer reversible Li{sup +} ion intercalation and deintercalation in a 1 M LiClO{sub 4}-propylene carbonate electrolyte. Light modulation with transmittance variation of up to 61%, optical density change of 0.54 and coloration efficiency of 37.5 cm{sup 2}/C at a wavelength of 550 nm after 200 cycles of cyclic voltammetry switching measurements is achieved. - Highlights: ► Fast deposition of MoO{sub x}C{sub y} film by an atmospheric pressure plasma jet ► Organic–inorganic hybrid MoO{sub x}C{sub y} films synthesized ► Flexible and electrochromic MoO{sub x}C{sub y} films produced.

  6. Hippophae rhamnoides L. Fruits Reduce the Oxidative Stress in Human Blood Platelets and Plasma.

    Science.gov (United States)

    Olas, Beata; Kontek, Bogdan; Malinowska, Paulina; Żuchowski, Jerzy; Stochmal, Anna

    2016-01-01

    Effects of the phenolic fraction from Hippophae rhamnoides fruits on the production of thiobarbituric acid reactive substances (TBARS, a marker of lipid peroxidation) and the generation of superoxide anion (O2 (-∙)) in human blood platelets (resting platelets and platelets stimulated by a strong physiological agonist, thrombin) were studied in vitro. We also examined antioxidant properties of this fraction against human plasma lipid peroxidation and protein carbonylation induced by a strong biological oxidant, hydrogen peroxide (H2O2) or H2O2/Fe (a donor of hydroxyl radicals). The tested fraction of H. rhamnoides (0.5- 50 µg/mL; the incubation time: 15 and 60 min) inhibited lipid peroxidation induced by H2O2 or H2O2/Fe. The H. rhamnoides phenolic fraction inhibited not only plasma lipid peroxidation, but also plasma protein carbonylation stimulated by H2O2 or H2O2/Fe. Moreover, the level of O2 (-∙) in platelets significantly decreased. In comparative experiments, the H. rhamnoides fraction was a more effective antioxidant than aronia extract or grape seed extract (at the highest tested concentration, 50 µg/mL). The obtained results suggest that H. rhamnoides fruits may be a new, promising source of natural compounds with antioxidant and antiplatelet activity beneficial not only for healthy people, but also for those with oxidative stress-associated diseases.

  7. Hippophae rhamnoides L. Fruits Reduce the Oxidative Stress in Human Blood Platelets and Plasma

    Directory of Open Access Journals (Sweden)

    Beata Olas

    2016-01-01

    Full Text Available Effects of the phenolic fraction from Hippophae rhamnoides fruits on the production of thiobarbituric acid reactive substances (TBARS, a marker of lipid peroxidation and the generation of superoxide anion (O2-∙ in human blood platelets (resting platelets and platelets stimulated by a strong physiological agonist, thrombin were studied in vitro. We also examined antioxidant properties of this fraction against human plasma lipid peroxidation and protein carbonylation induced by a strong biological oxidant, hydrogen peroxide (H2O2 or H2O2/Fe (a donor of hydroxyl radicals. The tested fraction of H. rhamnoides (0.5– 50 µg/mL; the incubation time: 15 and 60 min inhibited lipid peroxidation induced by H2O2 or H2O2/Fe. The H. rhamnoides phenolic fraction inhibited not only plasma lipid peroxidation, but also plasma protein carbonylation stimulated by H2O2 or H2O2/Fe. Moreover, the level of O2-∙ in platelets significantly decreased. In comparative experiments, the H. rhamnoides fraction was a more effective antioxidant than aronia extract or grape seed extract (at the highest tested concentration, 50 µg/mL. The obtained results suggest that H. rhamnoides fruits may be a new, promising source of natural compounds with antioxidant and antiplatelet activity beneficial not only for healthy people, but also for those with oxidative stress-associated diseases.

  8. Products and mechanisms of the oxidation of organic compounds in atmospheric air plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Marotta, Ester; Schiorlin, Milko; Paradisi, Cristina [Department of Chemical Sciences, Universita di Padova, Via Marzolo 1, 35131 Padova (Italy); Rea, Massimo, E-mail: cristina.paradisi@unipd.i [Department of Electrical Engineering, Universita di Padova, 35131 Padova (Italy)

    2010-03-31

    Atmospheric plasma-based technologies are developing as a powerful means for air purification, specifically for the oxidation of organic pollutants. To achieve a better control on the emissions produced by such treatments mechanistic insight is needed in the complex reactions of volatile organic compounds (VOCs) within the plasma. An account is given here of our comparative studies of the behaviour of model VOCs in response to different corona regimes (+dc, -dc and +pulsed) implemented within the same flow reactor. Model VOCs considered include two alkanes (n-hexane and i-octane), one aromatic hydrocarbon (toluene) and two halogenated methanes, dibromomethane (CH{sub 2}Br{sub 2}) and dibromodifluoromethane (CF{sub 2}Br{sub 2}, halon 1202). Efficiency and product data are reported and discussed as well as various possible initiation reactions. A powerful diagnostic tool is ion analysis, performed by atmospheric pressure chemical ionization-mass spectrometry: it provides a map of major ions and ion-molecule reactions and a rationale for interpreting current/voltage characteristics of dc coronas. It is shown that, depending on the specific VOC and corona regime adopted, different initiation steps prevail in the VOC-oxidation process and that the presence of a VOC, albeit in small amounts (500 ppm), can greatly affect some important plasma properties (ion population, current/voltage profile, post-discharge products).

  9. Effect of Ar bubbling during plasma electrolytic oxidation of AZ31B magnesium alloy in silicate electrolyte

    Science.gov (United States)

    Lee, Junghoon; Kim, Yonghwan; Chung, Wonsub

    2012-10-01

    Argon gas was bubbled during plasma electrolytic oxidation (PEO) treatment of magnesium alloy in a silicate solution. The appearance of arcs and plasma discharging was locally concentrated on the magnesium alloy surface and phase fraction of Mg2SiO4 in the oxide layer was increased due to Argon gas bubbling. The higher energy density of the Ar plasma atmosphere is believed to contribute to the effective formation of the high temperature phase (Mg2SiO4), particularly in the inner layer. Furthermore, the PEO treated Mg alloy with Ar bubbling showed improved corrosion resistance by a change of open pores structure.

  10. Oxidative status, in vitro iron-induced lipid oxidation and superoxide dismutase, catalase and glutathione peroxidase activities in rhea meat.

    Science.gov (United States)

    Terevinto, A; Ramos, A; Castroman, G; Cabrera, M C; Saadoun, A

    2010-04-01

    Rhea (Rhea americana) muscles Obturatorius medialis (OM) Iliotibialis lateralis (IL) and Iliofibularis (I), obtained from farmed animals, were evaluated regarding their oxidative/antioxidant status. The mean level of thiobarbituric acid reactive substances (TBARS) expressed as malonaldehyde (MDA) content was of 0.84 mg MDA/kg wet tissue for the three muscles. TBARS level was significantly higher in IL than OM and I, with the two latter showing similar levels. The mean level of carbonyl proteins expressed as dinitrophenylhydrazine (DNPH) was 1.59 nmol DNPH mg(-1). Carbonyl protein levels were significantly different (Pmuscles (IL>OM>I). Iron-induced TBARS generation was not significantly different between the three muscles at any time, nor for each muscle during the 5 h of the experiment. Superoxide dismutase activity in IL muscle was significantly higher (Pmuscle. However, the difference between IL and OM muscles was not significant. The differences between the three muscles became not significant when the results were expressed by mg of protein contained in the extract, instead by g of wet tissue. No differences were found for catalase (micromol of discomposed H(2)O(2) min(-1) g(-1) wet tissue or by mg of protein contained in the extract) and glutathione peroxidase (micromol ol of oxidized NADPH min(-1) g(-1) of wet tissue or by mg of protein contained in the extract) activities between the three muscles.

  11. Kinetic analysis of soil contained pyrene oxidation by a pulsed discharge plasma process

    Science.gov (United States)

    Huijuan, Wang; Guangshun, Zhou; He, Guo; Cong, Geng

    2017-01-01

    A pulsed discharge plasma (PDP) reactor with net anode and net cathode was established for investigating the pyrene degradation in soil under different pulse peak voltage, air flow rate, pyrene content in soil, initial pH value and initial water content of the soil. Pyrene oxidation within the 60 min discharge time was fitting according to the pseudo-first order equation and the corresponding reaction kinetics constants (k values) were calculated. The obtained results show that pyrene oxidation under all the different reaction conditions obeyed the pseudo-first order equation well. Higher pulsed peak voltage and appropriate air flow rate were in favor of the increase of reaction rate of pyrene oxidation. A higher k value could be achieved in the lower initial pyrene content (the value was 100 mg kg-1). The k value of pyrene oxidation in the case of pH = 4 was 11.2 times higher than the value obtained under the condition of pH = 9, while the initial water content of the soil also has a large effect on the oxidation rate of pyrene due to the effect of PDP. Supported by National Natural Science Foundation of China (No. 21207052).

  12. Phobic anxiety and plasma levels of global oxidative stress in women

    Directory of Open Access Journals (Sweden)

    Kaitlin A. Hagan

    2015-03-01

    Full Text Available Background and Objectives: Psychological distress has been hypothesized to be associated with adverse biologic states such as higher oxidative stress and inflammation. Yet, little is known about associations between a common form of distress -phobic anxiety- and global oxidative stress. Thus, we related phobic anxiety to plasma fluorescent oxidation products (FlOPs, a global oxidative stress marker. Methods: We conducted a cross-sectional analysis among 1,325 women (aged 43-70 years from the Nurses' Health Study. Phobic anxiety was measured using the Crown-Crisp Index (CCI. Adjusted least-squares mean log-transformed FlOPs were calculated across phobic categories. Logistic regression models were used to calculate odds ratios (OR comparing the highest CCI category (≥ 6 points vs. lower scores, across FlOPs quartiles. Results: No association was found between phobic anxiety categories and mean FlOP levels in multivariable adjusted linear models. Similarly, in multivariable logistic regression models there were no associations between FlOPs quartiles and likelihood of being in the highest phobic category. Comparing women in the highest vs. lowest FlOPs quartiles: FlOP_360: OR = 0.68 (95% CI: 0.40 - 1.15; FlOP_320: OR = 0.99 (95% CI: 0.61 - 1.61; FlOP_400: OR = 0.92 (95% CI: 0.52, 1.63. Conclusions: No cross-sectional association was found between phobic anxiety and a plasma measure of global oxidative stress in this sample of middle-aged and older women.

  13. Oxidative status imbalance in patients with metabolic syndrome: role of the myeloperoxidase/hydrogen peroxide axis.

    Science.gov (United States)

    da Fonseca, Lucas José Sá; Nunes-Souza, Valéria; Guedes, Glaucevane da Silva; Schettino-Silva, Glauber; Mota-Gomes, Marco Antônio; Rabelo, Luíza Antas

    2014-01-01

    The present study evaluated the cardiometabolic and redox balance profiles in patients with Metabolic Syndrome compared to apparently healthy individuals, and the participation of the myeloperoxidase/hydrogen peroxide axis in systemic lipid peroxidation. Twenty-four patients with Metabolic Syndrome and eighteen controls underwent a full clinical assessment. Venous blood samples were collected for general biochemical dosages, as well as for the oxidative stress analyses (superoxide dismutase, catalase, and arginase activities; and lipid peroxidation, myeloperoxidase activity, nitrite, and hydrogen peroxide concentrations in plasma). Arterial stiffness was assessed by radial artery applanation tonometry. Plasma lipid peroxidation, erythrocyte superoxide dismutase activity, myeloperoxidase activity, and hydrogen peroxide concentrations were shown to be increased in Metabolic Syndrome patients, without significant differences for the other enzymes, plasma nitrite concentrations, and arterial stiffness. Linear regression analysis revealed a positive and significant correlation between lipid peroxidation and myeloperoxidase and also between this enzyme and hydrogen peroxide. In contrast, such correlation was not observed between lipid peroxidation and hydrogen peroxide. In summary, Metabolic Syndrome patients exhibited evident systemic redox imbalance compared to controls, with the possible participation of the myeloperoxidase/hydrogen peroxide axis as a contributor in lipid peroxidation.

  14. Ceramic coatings of LA141 alloy formed by plasma electrolytic oxidation for corrosion protection.

    Science.gov (United States)

    Li, Zhijun; Yuan, Yi; Sun, Pengpeng; Jing, Xiaoyan

    2011-09-01

    Superlight Mg-Li alloy is a promising structural materials in aerospace, automobile, and electronics because of its excellent properties such as low density, high ductility, superior strength-to-weight ratio, and good damping ability. The fabrication of compact plasma electrolytic oxidation coatings with excellent corrosion resistance is valuable for the widespread application of Mg-Li alloy. Here we present a ceramic coating on the surface of Mg-14Li-1Al (LA141) alloy for corrosion protection via plasma electrolytic oxidation (PEO) in an alkaline silicate electrolyte with tungstate as an additive. X-ray photoelectron spectroscopy and thin film-X-ray diffraction analysis of coatings show that the surface coating is mainly comprised of Mg(2)SiO(4), MgO and WO(3). Scanning electron microscopy observations have revealed that the dense and compact coating formed in the presence of tungstate has less structural imperfections in comparison to the control one fabricated without use of tungstate. The effect of oxidation time on the morphology and phase composition of coatings is also examined in detail.

  15. TiO2 Deposition on AZ31 Magnesium Alloy Using Plasma Electrolytic Oxidation

    Directory of Open Access Journals (Sweden)

    Leon White

    2013-01-01

    Full Text Available Plasma electrolytic oxidation (PEO has been used in the past as a useful surface treatment technique to improve the anticorrosion properties of Mg alloys by forming protective layer. Coatings were prepared on AZ31 magnesium alloy in phosphate electrolyte with the addition of TiO2 nanoparticles using plasma electrolytic oxidation (PEO. This present work focuses on developing a TiO2 functional coating to create a novel electrophotocatalyst while observing the surface morphology, structure, composition, and corrosion resistance of the PEO coating. Microstructural characterization of the coating was investigated by X-ray diffraction (XRD and scanning electron microscopy (SEM followed by image analysis and energy dispersive spectroscopy (EDX. The corrosion resistance of the PEO treated samples was evaluated with electrochemical impedance spectroscopy (EIS and DC polarization tests in 3.5 wt.% NaCl. The XRD pattern shows that the components of the oxide film include Mg from the substrate as well as MgO and Mg2TiO4 due to the TiO2 nanoparticle addition. The results show that the PEO coating with TiO2 nanoparticles did improve the corrosion resistance when compared to the AZ31 substrate alloy.

  16. Spectroscopic study of plasma during electrolytic oxidation of magnesium-aluminium alloys

    Science.gov (United States)

    Jovović, J.

    2014-12-01

    Plasma during Electrolytic Oxidation (PEO) of magnesium-aluminium alloys is studied in this work by means of Optical Emission Spectroscopy (OES). Spectral line shapes of the Hβ, Al II 704.21 nm and Mg II 448.11 nm line are analyzed to measure plasma electron number density Ne. From the Hβ line profile, two PEO processes characterized by relatively low electron number densities Ne ≈ 1015 cm-3 and Ne ≈ 2 × 1016 cm-3 were discovered while the shape and shift of Al II and Mg II lines revealed the third process characterized by large electron density Ne = (1-2) × 1017 cm-3. Low Ne processes, related with breakdown in gas bubbles and on oxide surface, are not influenced by anode material or electrolyte composition. The ejection of evaporated anode material through oxide layer is designated here as third PEO process. Using the Boltzmann plot technique, electron temperature of 4000 K and 33000 K is determined from relative intensities of Mg I and O II lines, respectively. Several difficulties in the analysis of spectral line shapes are met during this study and the ways to overcome some of the obstacles are demonstrated.

  17. SEM And EDS Analysis Of Nitinol Surfaces Treated By Plasma Electrolytic Oxidation

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    Rokosz K.

    2015-09-01

    Full Text Available In the paper, the surface layers formed on nickel-titanium alloy during Plasma Electrolytic Oxidation (PEO, known also as Micro Arc Oxidation (MAO, are described. The mixture of phosphoric acid and copper nitrate as the electrolyte for all plasma electrochemical processes was used. Nitinol biomaterial was used for the studies. All the experiments were performed under the voltage of 450 V and current density of 0.3 A/dm2. The main purpose of the studies was to achieve the highest amount of copper in the surface layer versus amount of the copper nitrate in phosphoric acid. The highest copper concentration was found in the surface layer after the PEO treatment in the electrolyte consisting of 150g Cu(NO32 in 0.5 dm3 H3PO4. The worst results, in case of the amount of copper in the NiTi surface layer, were recorded after oxidizing in the solution with 5 g Cu(NO32.

  18. Response of cardiac endothelial nitric oxide synthase to plasma viscosity modulation in acute isovolemic hemodilution

    Directory of Open Access Journals (Sweden)

    Kanyanatt Kanokwiroon

    2014-01-01

    Full Text Available Background: Endothelial nitric oxide synthase (eNOS is generally expressed in endocardial cells, vascular endothelial cells and ventricular myocytes. However, there is no experimental study elucidating the relationship between cardiac eNOS expression and elevated plasma viscosity in low oxygen delivery pathological conditions such as hemorrhagic shock-resuscitation and hemodilution. This study tested the hypothesis that elevated plasma viscosity increases cardiac eNOS expression in a hemodilution model, leading to positive effects on cardiac performance. Materials and Methods: Two groups of golden Syrian hamster underwent an acute isovolemic hemodilution where 40% of blood volume was exchanged with 2% (low-viscogenic plasma expander [LVPE] or 6% (high-viscogenic plasma expander [HVPE] of dextran 2000 kDa. In control group, experiment was performed without hemodilution. All groups were performed in awake condition. Experimental parameters, i.e., mean arterial blood pressure (MAP, heart rate, hematocrit, blood gas content and viscosity, were measured. The eNOS expression was evaluated by eNOS Western blot analysis. Results: After hemodilution, MAP decreased to 72% and 93% of baseline in the LVPE and HVPE, respectively. Furthermore, pO 2 in the LVPE group increased highest among the groups. Plasma viscosity in the HVPE group was significantly higher than that in control and LVPE groups. The expression of eNOS in the HVPE group showed higher intensity compared to other groups, especially compared with the control group. Conclusion: Our results demonstrated that cardiac eNOS has responded to plasma viscosity modulation with HVPE and LVPE. This particularly supports the previous studies that revealed the positive effects on cardiac function in animals hemodiluted with HVPE.

  19. Manganese-cerium oxide catalysts prepared by non-thermal plasma for NO oxidation: Effect of O2 in discharge atmosphere

    Science.gov (United States)

    Liu, Lu; Zheng, Chenghang; Wu, Shenghao; Gao, Xiang; Ni, Mingjiang; Cen, Kefa

    2017-09-01

    Non-thermal plasma with different O2 concentration in discharge atmosphere was applied to synthesize manganese and cerium mixed-oxides catalysts, which were compared in NO oxidation activity. Discharge atmosphere displayed a crucial influence on the performance of the catalysts prepared by plasma. Relatively low O2 concentration in discharge atmosphere allows synthesizing manganese-cerium oxides catalysts in a moderate environment and therefore is favorable for better physicochemical properties which lead to superior catalytic behavior. The best catalyst was obtained by treatment with 10% O2/N2 plasma and presented over 80% NO conversion in the temperature range of 275-325 °C, whereas catalyst prepared in pure O2 discharge atmosphere had the same activity with a catalyst prepared by calcinations. A correlation between the surface properties of the plasma prepared catalysts and its catalytic activity in NO oxidation is proposed. The amount of the surface adsorbed oxygen has an obvious linear correlation with the amount of Ce3+, the H2 consumption at low temperatures and the catalytic performance. The superior catalytic performance is mainly attributed to the stronger interaction between manganese oxides and ceria, and the formation of poorly crystallized Mn-O-Ce phase in the catalyst which resulted from the slow decomposition of nitrates and organics during plasma treatment. Catalysts prepared in relatively low O2 concentration have large specific surface area and is abundant in Ce3+ species and active oxygen species. The study suggests that plasma treatment with proper discharge gas components is a promising method to prepare effective manganese- cerium oxides catalyst for NO oxidation.

  20. Preparation and high-temperature oxidation behavior of plasma Cr-Ni alloying on Ti6Al4V alloy based on double glow plasma surface metallurgy technology

    Science.gov (United States)

    Wei, Dong-Bo; Zhang, Ping-Ze; Yao, Zheng-Jun; Wei, Xiang-Fei; Zhou, Jin-Tang; Chen, Xiao-Hu

    2016-12-01

    To improve the oxidation resistance of Ti6Al4V alloy, it was coated with a Cr-Ni alloy with 20, 40, 60, and 80 at.% Ni content using the double-glow plasma surface metallurgy technology. The coatings were dense, uniform, and compact, including a complete structure of deposited layer, interdiffusion layer, and sputtering-affected zone. The effect of Ni content on the isothermal oxidation behavior of coating was investigated at 750, 850, and 950 °C. The results show that the oxide scale consisted of NiO and Cr2O3. The morphology and distribution of NiO in oxide scale were affected by oxidation temperature and Ni content. When the Ni content was ≤40 at.%, the oxidation resistance of the Cr-Ni alloy coating was enhanced.

  1. Association Analysis for Neuronal Nitric Oxide Synthase Gene Polymorphism with Plasma Nitrite/Nitrate Concentration in Schizophrenia

    Directory of Open Access Journals (Sweden)

    Đorđević Vladimir V.

    2014-09-01

    Full Text Available Background: Single nucleotide polymorphisms (SNP of many genes, including the gene for neuronal nitric oxide syn-thase (NOS1, were found significantly associated with schizo-phrenia. According to our previously published results of increased plasma nitric oxide concentration in patients with schizophrenia, we hypothesized that the NOS1 gene polymorphism might be a cause of increased nitric oxide production in patients with schizophrenia and tested the interdependence between plasma nitrite/nitrate concentrations and SNP (a CT transition located in exon 29 of the human NOS1 gene.

  2. Effects of atmospheric-pressure non-thermal bio-compatible plasma and plasma activated nitric oxide water on cervical cancer cells.

    Science.gov (United States)

    Li, Ying; Ho Kang, Min; Sup Uhm, Han; Joon Lee, Geon; Ha Choi, Eun; Han, Ihn

    2017-03-31

    Atmospheric-pressure non-thermal bio-compatible plasma is a partially ionized gas with electrically charged particles. Previous studies demonstrated that dielectric barrier discharge (DBD) plasma could induce apoptosis of various cancer cells, in particular demonstrating the selective cytotoxicity of cancer cells over normal cells. Therefore, DBD plasma can be considered as a potential cancer treatment method for clinical applications. We previously developed a microwave jet plasma system, producing nitric oxide called nitric oxide-plasma activated water (NO-PAW). In this study, we explored the effects of NO-PAW on a cervical cancer cell line, in comparison with DBD plasma. The cytotoxicity results showed that the treatment of HeLa cell with DBD for 4 minutes and 7 μM concentration of NO-PAW could reach almost IC60. For the apoptosis assay, 4 minutes treatment of DBD could induce 7% apoptotic effect, whereas 7 μM NO-PAW could induce 18% apoptotic effect. In addition, we assumed that both DBD plasma and NO-PAW could induce HeLa cell apoptosis by facilitating an accumulation of intracellular reactive oxygen and nitrogen species (RONS). Although further detail on the molecular signal pathway is still needed, DBD and NO-PAW could become promising applications for effective and safe clinical trials for cancer therapy.

  3. Effects of atmospheric-pressure non-thermal bio-compatible plasma and plasma activated nitric oxide water on cervical cancer cells

    Science.gov (United States)

    Li, Ying; Ho Kang, Min; Sup Uhm, Han; Joon Lee, Geon; Ha Choi, Eun; Han, Ihn

    2017-01-01

    Atmospheric-pressure non-thermal bio-compatible plasma is a partially ionized gas with electrically charged particles. Previous studies demonstrated that dielectric barrier discharge (DBD) plasma could induce apoptosis of various cancer cells, in particular demonstrating the selective cytotoxicity of cancer cells over normal cells. Therefore, DBD plasma can be considered as a potential cancer treatment method for clinical applications. We previously developed a microwave jet plasma system, producing nitric oxide called nitric oxide-plasma activated water (NO-PAW). In this study, we explored the effects of NO-PAW on a cervical cancer cell line, in comparison with DBD plasma. The cytotoxicity results showed that the treatment of HeLa cell with DBD for 4 minutes and 7 μM concentration of NO-PAW could reach almost IC60. For the apoptosis assay, 4 minutes treatment of DBD could induce 7% apoptotic effect, whereas 7 μM NO-PAW could induce 18% apoptotic effect. In addition, we assumed that both DBD plasma and NO-PAW could induce HeLa cell apoptosis by facilitating an accumulation of intracellular reactive oxygen and nitrogen species (RONS). Although further detail on the molecular signal pathway is still needed, DBD and NO-PAW could become promising applications for effective and safe clinical trials for cancer therapy. PMID:28361987

  4. Temperature and Nitric Oxide Generation in a Pulsed Arc Discharge Plasma

    Institute of Scientific and Technical Information of China (English)

    T.NAMIHIRA; S.SAKAI; M.MATSUDA; D.WANG; T.KIYAN; H.AKIYAMA; K.OKAMOTO; K.TODA

    2007-01-01

    Nitric oxide (NO) is increasingly being used in medical treatments of high blood pressure,acute respiratory distress syndrome and other illnesses related to the lungs.Currently a NO inhalation system consists of a gas cylinder of N2 mixed with a high concentration of NO.This arrangement is potentially risky due to the possibility of an accidental leak of NO from the cylinder.The presence of NO in the air leads to the formation of nitric dioxide (NO2),which is toxic to the lungs.Therefore,an on-site generator of NO would be highly desirable for medical doctors to use with patients with lung disease.To develop the NO inhalation system without a gas cylinder,which would include a high concentration of NO,NAMIHIRA et al have recently reported on the production of NO from room air using a pulsed arc discharge.In the present work,the temperature of the pulsed arc discharge plasma used to generate NO was measured to optimize the discharge condition.The results of the temperature measurements showed the temperature of the pulsed arc discharge plasma reached about 10,000 K immediately after discharge initiation and gradually decreased over tens of microseconds.In addition,it was found that NO was formed in a discharge plasma having temperatures higher than 9,000 K and a smaller input energy into the discharge plasma generates NO more efficiently than a larger one.

  5. Plasma trimethylamine-N-oxide following supplementation with vitamin D or D plus B vitamins.

    Science.gov (United States)

    Obeid, Rima; Awwad, Hussain M; Kirsch, Susanne H; Waldura, Christiane; Herrmann, Wolfgang; Graeber, Stefan; Geisel, Juergen

    2017-02-01

    We compared the effect of supplementation with vitamin D + B or vitamin D on plasma trimethylamine N-oxide (TMAO) and choline metabolites. This is a randomized single-blinded nonplacebo-controlled study. Twenty-seven participants received 1200 IU vitamin D3 and 800 mg calcium, and 25 participants received additionally 0.5 mg folic acid, 50 mg B6, and 0.5 mg B12 for 1 year. Plasma homocysteine (Hcy), TMAO, and choline metabolites were measured at baseline and 12 months later. TMAO declined in the vitamin D arm by 0.5 versus 2.8 μmol/L in the D + B arm (p = 0.005). Hcy decreased and betaine increased in the D + B compared to the D arm. Within-subject levels of plasma choline and dimethylglycine and urine betaine increased in both arms and changes did not differ between the arms. TMAO reduction was predicted by higher baseline TMAO and lowering Hcy in stepwise regression analysis. The test-retest variations of TMAO were greater in the D + B arm compared to vitamin D arm. B vitamins plus vitamin D lowered plasma fasting TMAO compared to vitamin D. Vitamin D caused alterations in choline metabolism, which may reflect the metabolic flexibility of C1-metabolism. The molecular mechanisms and health implications of these changes are currently unknown. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Identification of plasma proteins that are susceptible to thiol oxidation by hypochlorous acid and N-chloramines.

    Science.gov (United States)

    Summers, Fiona A; Morgan, Philip E; Davies, Michael J; Hawkins, Clare L

    2008-09-01

    Hypochlorous acid (HOCl), the major strong oxidant produced by myeloperoxidase, reacts readily with free amino groups to form N-chloramines. Although HOCl and N-chloramines play an important role in the human immune system by killing bacteria and invading pathogens, they have also been shown to cause damage to tissues, which is believed to contribute to a number of diseases. It has been shown previously that N-chloramines react more readily with protein thiols than with other targets in plasma, but the nature of the plasma thiol-containing proteins oxidized is unknown. In this study, the ability of N-chloramines to selectively oxidize thiol-containing plasma proteins was determined using the thiol-specific probe, 5-iodoacetamidofluorescein, combined with two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Experiments were performed with N-chloramines formed on Nalpha-acetyl-lysine, Nalpha-acetyl-histidine (HisCA), glycine, taurine, and ammonia. With the exception of HisCA, the N-chloramines were more efficient than HOCl at oxidizing plasma thiols. The thiol-containing plasma proteins alpha1-antitrypsin and transthyretin were found to be oxidized in addition to albumin, with this treatment resulting in the inactivation of alpha1-antitrypsin. A similar selectivity of reaction and extent of thiol oxidation were also observed with myeloperoxidase in the presence of hydrogen peroxide and chloride ions.

  7. Catalyst-Packed Non-Thermal Plasma Reactor for Removal of Nitrogen Oxides

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A single-stage plasma-catalytic reactor in which catalytic materials were packedwas used to remove nitrogen oxides. The packing material was scoria being made of various metaloxides including A12O3, MgO, TiO2, etc. Scoria was able to act not only as dielectric pelletsbut also as a catalyst in the presence of reducing agent such as ethylene and ammonia. Withoutplasma discharge, scoria did not work well as a catalyst in the temperature range of 100 °Cto 200 °C, showing less than 10% of NOx removal efficiency. When plasma is produced inside thereactor, the NOx removal efficiency could be increased to 60% in this temperature range.

  8. Synthesis of Magnesium Oxide Nanopowder by Thermal Plasma Using Magnesium Nitrate Hexahydrate

    Directory of Open Access Journals (Sweden)

    V. Sirota

    2016-01-01

    Full Text Available Magnesium oxide (MgO nanopowder was synthesized by thermal plasma in a novel thermal DC plasma torch using magnesium nitrate hexahydrate. Magnesium nitrate hexahydrate (Mg(NO32·6H2O was obtained from serpentinite (Mg3Si2O5(OH4; lizardite (Halilovskiy array, Orenburg region, Russia. The synthesized samples were characterized by analytical techniques including X-ray diffraction (XRD and transmission electron microscopy (TEM. XRD and TEM characterization studies confirmed that MgO nanopowder obtained has periclase structure with high purity, and the particle sizes vary within the range of 100 nm to 150 nm. We believe that the present work will promote further experimental studies on the physical properties and the applications of MgO nanopowders in the fields such as high-densed ceramics, additives in bactericide, and refractory products.

  9. A cleaning method for reduced graphene oxide by inductively coupled plasma

    Science.gov (United States)

    Shen, Yan; Zhou, Peng; Zhang, David Wei

    2016-10-01

    In this work, we make reduced graphene oxide (rGO) solution via chemical way and use it to fabricate Field-effect transistor (FET) channel by spin coating for investigating the performance of grapheme-based devices. An inductively coupled plasma (ICP) with very low plasma density is applied to etch the surface of rGO. It has been confirmed that residues and contaminations can be removed through etching and proper etching parameters can lead to better electrical properties more like the pristine graphene without creating defects. Considering the application of graphene added to silicon-based electronic devices, such a cleaning method can be used due to its advantages of being a low-temperature, large-area, high-throughput, and Si-compatible process.

  10. Correlation between discharging property and coatings microstructure during plasma electrolytic oxidation

    Institute of Scientific and Technical Information of China (English)

    GUAN Yong-jun; XIA Yuan

    2006-01-01

    The voltage-current properties during plasma electrolytic discharge were determined by measuring the current density and cell voltage as functions of processing time and then by mathematical transformation. Correlation between discharge I-V property and the coatings microstructure on aluminum alloy during plasma electrolytic oxidation was determined by comparing the voltage-current properties at different process stages with SEM results of the corresponding coatings. The results show that the uniform passive film corresponds to a I-V property with one critical voltage, and a compound of porous layer and sintered ceramic particles corresponds to a I-V property with two critical voltages. The growth regularity of PEO cermet coatings was also studied.

  11. The importance of the oxidative status of dairy cattle in the periparturient period: revisiting antioxidant supplementation.

    Science.gov (United States)

    Abuelo, A; Hernández, J; Benedito, J L; Castillo, C

    2015-12-01

    Dairy cows are especially vulnerable to health disorders during the transition period, when they shift from late pregnancy to the onset of lactation. Diseases at this stage affect not only the animals' well-being, but also cause a major economic impact in dairy farms, because apart from treatment costs, affected cows will not reach their peak milk-producing capacity. The overproduction of reactive oxygen species (ROS) leads to oxidative stress, which has been identified as an underlying factor of dysfunctional inflammatory responses. Supplementation with vitamins and trace elements attempts to minimize the harmful consequences of excessive ROS production, thereby trying to improve animals' health status and to reduce disease incidence. However, results regarding the effects of supplementing antioxidants on dairy cows' health and performance have been inconsistent, because in most cases, the antioxidant potential of the animals was not assessed beforehand and the nutritional strategy planned accordingly. Therefore, reviewing the physiological and harmful effects of ROS production, along with the different options available for assessing the redox balance in dairy cattle and some of the key findings of different supplementation trials, could bring one step forward the on-farm application of determinations of oxidative status for establishing nutritional strategies early enough in the dry period that could improve transition cow health.

  12. Effect of Echinacea purpurea L. on oxidative status and meat quality in Arbor Acres broilers.

    Science.gov (United States)

    Lee, Tzu Tai; Ciou, Jhih Ying; Chen, Chung Li; Yu, Bi

    2013-01-15

    Echinacea purpurea L. (EP) is a popular herbal antioxidant and immunomodulator. The present study was conducted to evaluate the effects of EP on meat quality and oxidative status in broilers. Two hundred and fifty (1-day-old) male broilers (Arbor Acres) were randomly allocated to five groups including the control (corn-soybean meal diet) and 0.1, 0.5, 1.0 and 2.0% EP powder groups, with two replicates per treatment group. The results indicated that the addition of 0.5% and 1.0% EP significantly increased water-holding capacity and decreased storage loss of breast and thigh fillets at 35 days old. For fillet colour, L* (lightness) values were lower, and a* (redness) and b* (yellowness) values were higher with EP supplementation. Lower crude fat contents were observed in EP groups in comparison with control at 35 days of age in breast and thigh fillets, respectively. Production of malondialdehyde was slightly reduced in serum of EP supplemented birds compared to the control group. Results for Trolox equivalent antioxidant capacity, catalase and superoxide dismutase were significantly higher for the 0.5, 1.0 and 2.0% EP supplemental groups than control group in serum. Liver and spleen tissues results showed that the antioxidative enzymes activities were higher with EP powder at 35 days of age. Dried EP can be used as a feed additive to improve the meat quality and oxidative status in Arbor Acres broilers. Copyright © 2012 Society of Chemical Industry.

  13. MCP-1 binds to oxidized LDL and is carried by lipoprotein(a) in human plasma

    Science.gov (United States)

    Wiesner, Philipp; Tafelmeier, Maria; Chittka, Dominik; Choi, Soo-Ho; Zhang, Li; Byun, Young Sup; Almazan, Felicidad; Yang, Xiaohong; Iqbal, Navaid; Chowdhury, Punam; Maisel, Alan; Witztum, Joseph L.; Handel, Tracy M.; Tsimikas, Sotirios; Miller, Yury I.

    2013-01-01

    Lipoprotein oxidation plays an important role in pathogenesis of atherosclerosis. Oxidized low density lipoprotein (OxLDL) induces profound inflammatory responses in vascular cells, such as production of monocyte chemoattractant protein-1 (MCP-1) [chemokine (C-C motif) ligand 2], a key chemokine in the initiation and progression of vascular inflammation. Here we demonstrate that OxLDL also binds MCP-1 and that the OxLDL-bound MCP-1 retains its ability to recruit monocytes. A human MCP-1 mutant in which basic amino acids Arg-18 and Lys-19 were replaced with Ala did not bind to OxLDL. The MCP-1 binding to OxLDL was inhibited by the monoclonal antibody E06, which binds oxidized phospholipids (OxPLs) in OxLDL. Because OxPLs are carried by lipoprotein(a) [Lp(a)] in human plasma, we tested to determine whether Lp(a) binds MCP-1. Recombinant wild-type but not mutant MCP-1 added to human plasma bound to Lp(a), and its binding was inhibited by E06. Lp(a) captured from human plasma contained MCP-1 and the Lp(a)-associated endogenous MCP-1 induced monocyte migration. These results demonstrate that OxLDL and Lp(a) bind MCP-1 in vitro and in vivo and that OxPLs are major determinants of the MCP-1 binding. The association of MCP-1 with OxLDL and Lp(a) may play a role in modulating monocyte trafficking during atherogenesis. PMID:23667177

  14. Increased oxidative stress and plasma Hsp70 levels among gasoline filling station attendants.

    Science.gov (United States)

    Xia, Bing; Chen, Kangcheng; Lv, Yingnan; Huang, Damin; Liu, Jing; Liang, Guiqiang; Zhang, Li'e; Wang, Fenfen; Su, Cheng; Zou, Yunfeng; Yang, Xiaobo

    2017-02-01

    Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic derivative of manganese (Mn) and is used as an antiknock agent and octane enhancer in gasoline. In this article, we tested the oxidative stress and heat stress protein (Hsp) 70 levels of gasoline station attendants to explore potential plasma biomarkers. Furthermore, the dose-response relationship was also identified. A total of 144 workers, including 96 petrol fillers and 48 cashiers, participated in the study. Ambient concentrations of benzene, toluene, ethylbenzene, and xylene (BTEX) and Mn were monitored at nine filling stations. During the measuring process, the individual cumulative exposure index was calculated. Plasma oxidative stress and Hsp70 levels were also analysed using enzyme-linked immunosorbent assay. The BTEX time-weighted average in office areas was significantly lower than in refuelling areas ( p stress indicators compared with the control group, respectively: superoxide dismutase (SOD), 39.18 ± 6.05 U/mL versus 52.84 ± 3.87 U/mL; glutathione peroxidase (GSH-Px), 186.07 ± 15.63 U versus 194.38 ± 10.42 U; and malondialdehyde (MDA), 1.68 ± 0.52 nmol/L versus 1.43 ± 0.64 nmol/L (in all comparisons, p level in the exposed group (2.77 ± 0.64 ng/mL) was significantly higher than in the control group (2.32 ± 0.87 ng/mL; p levels were inversely correlated with the activities of SOD ( r = -0.305) and GSH-Px ( r = -0.302) in the exposed group ( p levels and plasma MDA levels ( p stress among filling station attendants. Plasma Hsp70 levels could be used as a sensitive responsive biomarker for exposed workers.

  15. Oxidative Stress Assessment in Response to Ultraendurance Exercise: Thiols Redox Status and ROS Production according to Duration of a Competitive Race

    Directory of Open Access Journals (Sweden)

    Alessandra Vezzoli

    2016-01-01

    Full Text Available Purpose. Response to an ultraendurance competitive race on thiols redox status, reactive oxygen species (ROS production, and oxidative stress (OxS was investigated according to duration. Methods. Twenty-four elite runners were examined: six completed 50 km and eighteen 100 km. Blood and urine samples were collected before and immediately after the race. Erythrocytes and plasma aminothiols by high-performance liquid chromatography, total antioxidant capacity (TAC, and OxS biomarkers (protein carbonyl (PC, thiobarbituric acid-reactive substances (TBARS, 8-isoprostane (8-iso-PGF2α, and 8-OH-2-deoxyguanosine (8-OH-dG by immunoenzymatic assays and ROS production by Electron Paramagnetic Resonance were assessed. Results. Significant increases (P between <0.05 and <0.0001 were recorded in plasma total and oxidized aminothiols concentration and TAC (P<0.0001 only after 100 km: plasmatic (ROS production (+12 versus +29%, PC (+54 versus +115%, and TBARS (+28 versus +55% and urinary (8-OH-dG.creatinine−1 (+71 versus +158% and 8-iso-PGF2α.creatinine−1 (+43 versus +135% concentrations for 50 and 100 km (duration 4 h 3′ versus 8 h 42′, respectively. Conclusion. Very prolonged ultraendurance exercise causes an increase in ROS production and OxS depending on specific biomarker examined but always linearly and directly related to exercise duration. Redox status of erythrocytes was preserved. A relationship between running performance and both prerace ROS production and antioxidant-redox status was found in 100 km race.

  16. Note: Rapid reduction of graphene oxide paper by glow discharge plasma

    Energy Technology Data Exchange (ETDEWEB)

    Bo, Zheng; Qian, Jiajing; Duan, Liangping; Qiu, Kunzan, E-mail: qiukz@zju.edu.cn; Yan, Jianhua; Cen, Kefa [State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou, Zhejiang 310027 (China); Han, Zhao Jun [CSIRO Manufacturing Flagship, P.O. Box 218, Bradfield Road, Lindfield, New South Wales 2070 (Australia); Ostrikov, Kostya [CSIRO Manufacturing Flagship, P.O. Box 218, Bradfield Road, Lindfield, New South Wales 2070 (Australia); Institute for Future Environments and School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, Queensland 4000 (Australia)

    2015-05-15

    This note reports on a novel method for the rapid reduction of graphene oxide (GO) paper using a glow discharge plasma reactor. Glow discharge is produced and sustained between two parallel-plate graphite electrodes at a pressure of 240 mTorr. By exposing GO paper at the junction of negative-glow and Faraday-dark area for 4 min, the oxygen-containing groups can be effectively removed (C/O ratio increases from 2.6 to 7.9), while the material integrality and flexibility are kept well. Electrochemical measurements demonstrate that the as-obtained reduced GO paper can be potentially used for supercapacitor application.

  17. Plasma Electrolytic Oxidation (PEO) Coatings on an A356 Alloy for Improved Corrosion and Wear Resistance

    Science.gov (United States)

    Peng, Zhijing

    Plasma electrolytic oxidizing (PEO) is an advanced technique that has been used to deposit thick and hard ceramic coatings on aluminium (Al) alloys. This work was however to use the PEO process to produce thin ceramic oxide coatings on an A356 Al alloy for improving corrosion and wear resistance of the alloy. Effects of current density and treatment time on surface morphologies and thickness of the PEO coatings were investigated. The improvement of galvanic corrosion properties of the coated A356 alloy vs. steel and carbon fibre were evaluated in E85 fuel or NaCl environments. Tribological properties of the coatings were studied with comparison to the uncoated A356 substrate and other commercially-used engine bore materials. The research results indicated that the PEO coatings could have excellent tribological and corrosion properties for aluminium engine applications.

  18. Gas Sensors Based on Tin Oxide Nanoparticles Synthesized from a Mini-Arc Plasma Source

    Directory of Open Access Journals (Sweden)

    Ganhua Lu

    2006-01-01

    Full Text Available Miniaturized gas sensors or electronic noses to rapidly detect and differentiate trace amount of chemical agents are extremely attractive. In this paper, we report on the fabrication and characterization of a functional tin oxide nanoparticle gas sensor. Tin oxide nanoparticles are first synthesized using a convenient and low-cost mini-arc plasma source. The nanoparticle size distribution is measured online using a scanning electrical mobility spectrometer (SEMS. The product nanoparticles are analyzed ex-situ by high resolution transmission electron microscopy (HRTEM for morphology and defects, energy dispersive X-ray (EDX spectroscopy for elemental composition, electron diffraction for crystal structure, and X-ray photoelectron spectroscopy (XPS for surface composition. Nonagglomerated rutile tin oxide (SnO2 nanoparticles as small as a few nm have been produced. Larger particles bear a core-shell structure with a metallic core and an oxide shell. The nanoparticles are then assembled onto an e-beam lithographically patterned interdigitated electrode using electrostatic force to fabricate the gas sensor. The nanoparticle sensor exhibits a fast response and a good sensitivity when exposed to 100 ppm ethanol vapor in air.

  19. Reproductive parameters and oxidative stress status of male rats fed with low and high salt diet

    Directory of Open Access Journals (Sweden)

    Bolanle O Iranloye

    2013-01-01

    Full Text Available Background: Deficiency of minerals and micronutrients has been reported to impair the process of spermatogenesis. Historically, salt has been used by women on their husbands to increase their libido, however, the role of salt diet on sperm parameters are yet to be ascertained. AIM: The present study was designed to determine the effect of low and high salt diet on sperm parameters, oxidative status and reproductive hormone levels of male rats. Materials and Methods: A total of 18 rats were divided into three groups: Group I: (control received 0.3% salt diet, Group II: low salt (received 0.14% salt diet and Group III: high salt (received 8% salt diet. All animals were treated for 6 weeks; after which epididymal sperm parameters; oxidative stress markers (malondialdehyde, glutathione, catalase and superoxide dismutase in the testes and epididymal tissues, as well as follicle stimulating hormone (FSH, luteinizing hormone (LH and testosterone levels were determined. Results: The results showed decreased sperm count in the low salt diet rats while increased sperm count was observed in the high salt diet treated rats. Both low salt and high salt diet fed rats exhibited increased abnormal sperm cells and increased epididymal oxidative stress when compared with their respective control. FSH and testosterone levels were increased in the high salt fed rats while LH level was decreased when compared with the control values. Conclusion: This study suggests that both low and high salt diet play a negative role in the fertility of male rats.

  20. Effect of Plasma Uric Acid on Antioxidant Capacity, Oxidative Stress, and Insulin Sensitivity in Obese Subjects

    Science.gov (United States)

    Fabbrini, Elisa; Serafini, Mauro; Colic Baric, Irena; Hazen, Stanley L.; Klein, Samuel

    2014-01-01

    Oxidative stress is purported to be involved in the pathogenesis of obesity-associated insulin resistance. We evaluated whether alterations in levels of circulating uric acid (UA), a systemic antioxidant, affects the following: 1) systemic (plasma and saliva) nonenzymatic antioxidant capacity (NEAC); 2) markers of systemic (urinary 8-iso-prostaglandin-F2α) and muscle (carbonylated protein content) oxidative stress; and 3) whole-body insulin sensitivity (percentage increase in glucose uptake during a hyperinsulinemic-euglycemic clamp procedure). Thirty-one obese subjects (BMI 37.1 ± 0.7 kg/m2) with either high serum UA (HUA; 7.1 ± 0.4 mg/dL; n = 15) or normal serum UA (NUA; 4.5 ± 0.2 mg/dL; n = 16) levels were studied; 13 subjects with HUA levels were studied again after reduction of serum UA levels to 0 by infusing a recombinant urate oxidase. HUA subjects had 20–90% greater NEAC, but lower insulin sensitivity (40%) and levels of markers of oxidative stress (30%) than subjects in the NUA group (all P < 0.05). Acute UA reduction caused a 45–95% decrease in NEAC and a 25–40% increase in levels of systemic and muscle markers of oxidative stress (all P < 0.05), but did not affect insulin sensitivity (from 168 ± 25% to 156 ± 17%, P = NS). These results demonstrate that circulating UA is a major antioxidant and might help protect against free-radical oxidative damage. However, oxidative stress is not a major determinant of insulin action in vivo. PMID:24353177

  1. Zinc oxide based nanocomposite thin film electrodes and the effect of D.C. plasma oxidation power on discharge capacity for lithium ion batteries.

    Science.gov (United States)

    Akbulut, Hatem; Guler, Mehmet Oguz; Aydin, Yasemin

    2012-12-01

    Zinc oxide based thin films have been grown on glass and stainless steel substrates in two steps; thermal evaporation from high purity metallic zinc and D.C. plasma oxidation. X-ray diffraction has shown that the films were polycrystalline nature and small predominant orientation at some specific planes. Analysis showed that plasma oxidation starts from the thermally evaporated leaf-like surfaces and produces a core-shell structure of ZnO on the metallic Zn. Increasing plasma oxidation power causes increased amount of ZnO volume and resistivity. Coin-type (CR2016) test cells were assembled in an argon-filled glove box and cyclically tested. The electrochemical performance of the films has been studied by cyclic voltammetry. The dependence of converted Li-ions on voltage profile of the films has been determined. It was found that the Zn/ZnO films exhibited highest the number of converted Li-ions at 175 W plasma oxidation conditions. Discharge capacity measurements revealed the double phase structures of Zn/ZnO exhibited significantly high reversible capacities. The high capacity and low capacity fade values were attributed to the high electrical conductivity and buffering ability of metallic Zn in the anodes.

  2. Comparison of Nitric Oxide Concentrations in μs- and ns-Atmospheric Pressure Plasmas by UV Absorption Spectroscopy

    Science.gov (United States)

    Peters, F.; Hirschberg, J.; Mertens, N.; Wieneke, S.; Viöl, W.

    2016-04-01

    In this paper, an absorption spectroscopy measurement method was applied on two atmospheric pressure plasma sources to determine their production of nitric oxide. The concentrations are essential for evaluating the plasma sources based on the principle of the Dielectric Barrier Discharge (DBD) for applications in plasma medicine. The described method is based on a setup with an electrodeless discharge lamp filled with a mixture of oxygen and nitrogen. One of the emitted wavelengths is an important resonance wavelength of nitric oxide (λ = 226.2 nm). By comparing the absorption behaviour at the minimum and maximum of the spectral absorption cross section of nitric oxide around that wavelength, and measuring the change in intensity by the absorbing plasma, the concentration of nitric oxide inside the plasma can be calculated. The produced nitric oxide concentrations depend on the pulse duration and are in the range of 180 ppm to 1400 ppm, so that a distance of about 10cm to the respiratory tract is enough to conform to the VDI Guideline 2310.

  3. Growth and Corrosion Characteristics of Plasma Electrolytic Oxidation Ceramic Films Formed on AZ31 Magnesium Alloy

    Institute of Scientific and Technical Information of China (English)

    王丽; 陈砺; 严宗诚; 王红林; 彭家志

    2009-01-01

    The growth characteristics of oxide ceramic films formed on AZ31 magnesium alloy with plasma electrolytic oxidation(PEO)technique in alkaline silicate solution Were investigated.The composition,slructure and morphology of the coatings were detected by energy dispersive X-ray spectroscope and scanning electron microscope.The amount of dissolved magnesium in the electrolytes during PEO process was measured by atomic absorption spectrometry.The results indicated that the growth process of PEO films had three stages when applied with constant voltage mode.In the first stage,the growth rate of PEO films was low,and concentrations of elements O.Mg and Si varied slightly.Atter sparking occurred(the second stage).the PEO films showed higher growth rate due to the high transfer rate of ionS and electrons,and the existoncc of plasma reactions.When the growth rate tended to maintain stable with time,the third stage happened.PEO films exhibited different uniform and pitting.corrosion characteristiCS in difierent reaction stages.The films formed at 300 V for 30 min performed best corrosion resistance and the phase of ceramic films was mainly composed of MgSiO3 and forsterite Mg2SiO4.

  4. Impact of Seminal Chemical Elements on the Oxidative Balance in Bovine Seminal Plasma and Spermatozoa.

    Science.gov (United States)

    Tvrdá, Eva; Lukáč, Norbert; Schneidgenová, Monika; Lukáčová, Jana; Szabó, Csaba; Goc, Zofia; Greń, Agnieszka; Massányi, Peter

    2013-01-01

    Mutual relationships between selected chemical elements (Na, K, Fe, Cu, Mg, and Zn), basic motility characteristics (motility and progressive motility), and markers of the oxidative balance (superoxide dismutase, catalase, glutathione, albumin, and malondialdehyde) were investigated in bovine seminal plasma and spermatozoa. Computer assisted sperm analysis was used to assess the motility parameters; mineral concentrations were determined by the voltammetric method and flame absorption spectrophotometry; antioxidants and malondialdehyde were evaluated by UV/VIS spectrophotometry. Concentrations of chemical elements in both seminal fractions were in the following descending order: Na > K > Zn > Mg > Fe > Cu. Higher amounts of all minerals and nonenzymatic antioxidants were detected in the seminal plasma (P Zn were positively correlated with the motility and antioxidant parameters (P < 0.05; P < 0.01; P < 0.001). Inversely, K exhibited the positive associations with malondialdehyde (P < 0.05). This study demonstrates that most chemical elements are integral components of bovine semen and are needed for the protection against oxidative stress development.

  5. Impact of Seminal Chemical Elements on the Oxidative Balance in Bovine Seminal Plasma and Spermatozoa

    Directory of Open Access Journals (Sweden)

    Eva Tvrdá

    2013-01-01

    Full Text Available Mutual relationships between selected chemical elements (Na, K, Fe, Cu, Mg, and Zn, basic motility characteristics (motility and progressive motility, and markers of the oxidative balance (superoxide dismutase, catalase, glutathione, albumin, and malondialdehyde were investigated in bovine seminal plasma and spermatozoa. Computer assisted sperm analysis was used to assess the motility parameters; mineral concentrations were determined by the voltammetric method and flame absorption spectrophotometry; antioxidants and malondialdehyde were evaluated by UV/VIS spectrophotometry. Concentrations of chemical elements in both seminal fractions were in the following descending order: Na > K > Zn > Mg > Fe > Cu. Higher amounts of all minerals and nonenzymatic antioxidants were detected in the seminal plasma (P<0.01; P<0.001, while higher MDA concentration and activity of enzymatic antioxidants were recorded in the cell lysates (P<0.01; P<0.001. Na, Fe, Cu, Mg, and Zn were positively correlated with the motility and antioxidant parameters (P<0.05; P<0.01; P<0.001. Inversely, K exhibited the positive associations with malondialdehyde (P<0.05. This study demonstrates that most chemical elements are integral components of bovine semen and are needed for the protection against oxidative stress development.

  6. Electric Field Prediction using Micro-plasma Inside a Microwave Cavity for Soot Oxidation

    Directory of Open Access Journals (Sweden)

    Al-Wakeel Haitham B.

    2014-07-01

    Full Text Available The reduction of the harmful emission soot is necessary in recent years due to the environmental protection regulation. Soot is a carbonaceous matter and a strong absorber of microwave energy. Microwave heating offers the advantage over conventional heating to oxide soot. Where plasma is high electric field that leads to instantaneous temperature rising. This paper proposes a recent concept for soot oxidation using micro-plasma in a microwave cavity. The concept was presented by simulating the electric field using microwave heating and thin metal object. Five cases were examined numerically in a mono-mode TE10 microwave cavity WR430 having closed surfaces of perfect electric conductors working under 2.45 GHz frequency and 1500 W power supply to predict the electric field and dissipated heat distribution. The methodology of prediction was implemented using ANSYS based on FEM. The present prediction results showed higher electric field (400 kV/m and high dissipated heat (3.7×1010 W/m3 can be obtained for a soot sample backed with metal rods inserted vertically with gaps not exceeding 1.5 mm between the rods tips. Also increasing the number of metal rods, from 8 to 14 increases the maximum value of electric field formed in the soot sample to 575 kV/m. The simulation results revealed the ability of achieving high electric field by using microwave heating with the assistance of metal objects.

  7. Thermal annealing and exposure to divertor-like deuterium plasma of tailored tungsten oxide coatings

    Energy Technology Data Exchange (ETDEWEB)

    Pezzoli, A., E-mail: andrea.pezzoli@polimi.it [Dipartimento di Energia and NEMAS, Center for NanoEngineered Materials and Surfaces, Politecnico di Milano, Milano (Italy); Dellasega, D. [Dipartimento di Energia and NEMAS, Center for NanoEngineered Materials and Surfaces, Politecnico di Milano, Milano (Italy); Istituto di Fisica del Plasma, CNR, EURATOM-ENEA-CNR Association, Milano (Italy); Russo, V. [Dipartimento di Energia and NEMAS, Center for NanoEngineered Materials and Surfaces, Politecnico di Milano, Milano (Italy); Gallo, A. [Dipartimento di Energia and NEMAS, Center for NanoEngineered Materials and Surfaces, Politecnico di Milano, Milano (Italy); FOM Institute DIFFER – Dutch Institute for Fundamental Energy Research, Association EURATOM-FOM, Partner in the Trilateral Euregio Cluster, Nieuwegein (Netherlands); Zeijlmans van Emmichoven, P.A. [FOM Institute DIFFER – Dutch Institute for Fundamental Energy Research, Association EURATOM-FOM, Partner in the Trilateral Euregio Cluster, Nieuwegein (Netherlands); Passoni, M. [Dipartimento di Energia and NEMAS, Center for NanoEngineered Materials and Surfaces, Politecnico di Milano, Milano (Italy); Istituto di Fisica del Plasma, CNR, EURATOM-ENEA-CNR Association, Milano (Italy)

    2015-08-15

    In this work we produced tungsten (W) and W oxide (WO{sub x}) films by pulsed laser deposition (PLD) with the aim of the addressing modifications of structure and morphology that occur after annealing treatments and high-flux deuterium plasma. Thanks to the high flexibility of PLD we produced nanostructured W containing non-bounded oxygen, different types of WO{sub x} and multilayered films. W coatings are dense, non-porous and exhibit a nanocrystalline structure, resembling the coatings used as first wall in tokamaks. The oxide films are nearly stoichiometric amorphous WO{sub x} (x = 3) with different morphology from compact to porous. Depending on annealing temperature, nucleation of different crystalline phases (e.g. WO{sub 3}, W{sub 18}O{sub 49}) occurs. Exposure of films to high-flux (∼10{sup 24} m{sup −2} s{sup −1}) deuterium plasmas in Magnum-PSI at different surface temperatures (T{sub max} = 580 K) determines material modifications at the nanoscale (e.g. nanometric defects) but no delamination. In addition preliminary deuterium retention results are reported.

  8. Omega-3 fatty acids status in human subjects estimated using a food frequency questionnaire and plasma phospholipids levels

    Directory of Open Access Journals (Sweden)

    Garneau Véronique

    2012-07-01

    Full Text Available Abstract Background Intakes of omega-3 (n-3 fatty acids (FA are associated with several health benefits. The aim of this study was to verify whether intakes of n-3 FA estimated from a food frequency questionnaire (FFQ correlate with n-3 FA levels measured in plasma phospholipids (PL. Methods The study sample consisted of 200 French-Canadians men and women aged between 18 to 55 years. Dietary data were collected using a validated FFQ. Fasting blood samples were collected and the plasma PL FA profile was measured by gas chromatography. Results Low intakes of n-3 long-chain FA together with low percentages of n-3 long-chain FA in plasma PL were found in French-Canadian population. Daily intakes of eicosapentaenoic acid (EPA, docosapentaenoic acid (DPA and docosahexaenoic acid (DHA were similar between men and women. Yet, alpha-linolenic acid (ALA and total n-3 FA intakes were significantly higher in men compared to women (ALA: 2.28 g and 1.69 g, p n-3 FA: 2.57 g and 1.99 g, p n-3 FA (men: r = 0.47, p  Conclusion Estimated n-3 long-chain FA intake among this young and well-educated French-Canadian population is lower than the recommendations. Further, FFQ data is comparable to plasma PL results to estimate DHA and total n-3 FA status in healthy individuals as well as to evaluate the EPA and DPA status in women. Overall, this FFQ could be used as a simple, low-cost tool in future studies to rank n-3 FA status of individuals.

  9. Plasma-based conversion of CO2: current status and future challenges.

    Science.gov (United States)

    Bogaerts, Annemie; Kozák, Tomas; van Laer, Koen; Snoeckx, Ramses

    2015-01-01

    This paper discusses our recent results on plasma-based CO2 conversion, obtained by a combination of experiments and modeling, for a dielectric barrier discharge (DBD), a microwave plasma and a packed bed DBD reactor. The results illustrate that plasma technology is quite promising for CO2 conversion, but more research is needed to better understand the underlying mechanisms and to further improve the capabilities.

  10. Evaluation of oxidant and antioxidant status in term neonates: a plausible protective role of bilirubin.

    Science.gov (United States)

    Shekeeb Shahab, M; Kumar, Praveen; Sharma, Neeraj; Narang, Anil; Prasad, Rajendra

    2008-10-01

    In vitro studies have shown unequivocally that bilirubin is an antioxidant. We hypothesized that bilirubin serves a physiological role of an antioxidant in vivo. To investigate the probable protective role of bilirubin in vivo, term babies with clinical jaundice were grouped into four categories-serum total bilirubin (STB) 200 mg/l, and kernicterus. Serum bilirubin, serum albumin, plasma glucose-6-phosphate dehydrogenase (G6PD), lipid peroxidation in blood cells, and reduced glutathione (GSH) content in whole blood were investigated. We also measured superoxide dismutase (SOD) and catalase in hemolysate and total plasma antioxidant capacity (TAC). Lipid peroxidation and antioxidant enzymes were significantly lower in babies with STB 200 mg/l and in babies with bilirubin encephalopathy. Elevated levels of MDA, SOD, and catalase and significantly decreased levels of reduced glutathione and total antioxidant capacity were observed in STB >200 mg/l group. Antioxidant enzymes were also significantly inhibited in bilirubin encephalopathy babies. Post phototherapy, MDA production and antioxidant levels were significantly increased whilst total antioxidant capacity and reduced glutathione were significantly decreased compared to pre-phototherapy values. Exchange transfusion resulted in reduced oxidative stress in subjects with encephalopathy, whereas no significant difference was observed in other babies with STB >200 mg/l. Taken together, the present study propounds that bilirubin acts as a physiological antioxidant till 200 mg/l concentration in full-term normal neonates. It is conjectured that beyond 200 mg/l, it can no longer be considered physiologic. However, the cause of pathological jaundice needs to be identified and treated. The present data documents that phototherapy also induces oxidative stress.

  11. Real-time imaging, spectroscopy, and structural investigation of cathodic plasma electrolytic oxidation of molybdenum

    Energy Technology Data Exchange (ETDEWEB)

    Stojadinović, Stevan, E-mail: sstevan@ff.bg.ac.rs; Tadić, Nenad; Šišović, Nikola M.; Vasilić, Rastko [Faculty of Physics, University of Belgrade, Studentski trg 12-16, 11000 Belgrade (Serbia)

    2015-06-21

    In this paper, the results of the investigation of cathodic plasma electrolytic oxidation (CPEO) of molybdenum at 160 V in a mixed solution of borax, water, and ethylene glycol are presented. Real-time imaging and optical emission spectroscopy were used for the characterization of the CPEO. During the process, vapor envelope is formed around the cathode and strong electric field within the envelope caused the generation of plasma discharges. The spectral line shape analysis of hydrogen Balmer line H{sub β} (486.13 nm) shows that plasma discharges are characterized by the electron number density of about 1.4 × 10{sup 21 }m{sup −3}. The electron temperature of 15 000 K was estimated by measuring molybdenum atomic lines intensity. Surface morphology, chemical, and phase composition of coatings formed by CPEO were characterized by scanning electron microscopy with energy dispersive x-ray spectroscopy and x-ray diffraction. The elemental components of CPEO coatings are Mo and O and the predominant crystalline form is MoO{sub 3}.

  12. Hole injection enhancement in organic light emitting devices using plasma treated graphene oxide

    Science.gov (United States)

    Jesuraj, P. Justin; Parameshwari, R.; Kanthasamy, K.; Koch, J.; Pfnür, H.; Jeganathan, K.

    2017-03-01

    The hole injection layer (HIL) with high work function (WF) is desirable to reduce the injection barrier between anode and hole transport layer in organic light emitting devices (OLED). Here, we report a novel approach to tune the WF of graphene oxide (GO) using oxygen and hydrogen plasma treatment and its hole injection properties in OLEDs. The mild exposure of oxygen plasma on GO (O2-GO) significantly reduces the injection barrier by increasing the WF of anode (4.98 eV) through expansion of Csbnd O bonds. In contrast, the hole injection barrier was drastically increased for hydrogen plasma treated GO (H2-GO) layers as the WF is lowered by the contraction of Csbnd O bond. By employing active O2-GO as HIL in OLEDs found to exhibit superior current efficiency of 4.2 cd/A as compared to 3.3 cd/A for pristine GO. Further, the high injection efficiency of O2-GO infused hole only device can be attributed to the improved energy level matching. Ultraviolet and X-ray photoelectron spectroscopy were used to correlate the WF of HIL infused anode towards the enhanced performance of OLEDs with their capricious content of Csbnd O in GO matrix.

  13. Pentose phosphate pathway activity: effect on in vitro maturation and oxidative status of bovine oocytes.

    Science.gov (United States)

    Gutnisky, Cynthia; Dalvit, Gabriel C; Thompson, Jeremy G; Cetica, Pablo D

    2014-08-01

    The relationship between pentose phosphate pathway (PPP) activity in cumulus-oocyte complexes (COCs) and oxidative and mitochondrial activity in bovine oocytes was evaluated with the aim of analysing the impact of two inhibitors (NADPH and 6-aminonicotinamide (6-AN)) and a stimulator (NADP) of the key enzymes of the PPP on the maturation rate, oxidative and mitochondrial activity and the mitochondrial distribution in oocytes. The proportion of COCs with measurable PPP activity (assessed using brilliant cresyl blue staining), glucose uptake, lactate production and meiotic maturation rate diminished when 6-AN (0.1, 1, 5 and 10mM for 22h) was added to the maturation medium (P<0.05). The addition of NADPH did not modify glucose uptake or lactate production, but reduced PPP activity in COCs and meiotic maturation rates (P<0.05). The presence of NADP (0.0125, 0.125, 1.25 and 12.5mM for 22h of culture) in the maturation medium had no effect on PPP activity in COCs, glucose uptake, lactate production and meiotic maturation rate. However, in the absence of gonadotropin supplementation, NADP stimulated both glucose uptake and lactate production at 12.5mM (the highest concentration tested; P<0.05). NADP did not modify cleavage rate, but decreased blastocyst production (P<0.05). During IVM, oocyte oxidative and mitochondrial activity was observed to increase at 15 and 22h maturation, which was also related to progressive mitochondrial migration. Inhibiting the PPP with 6-AN or NADPH led to reduced oxidative and mitochondrial activity compared with the respective control groups and inhibition of mitochondrial migration (P<0.05). Stimulation of the PPP with NADP increased oxidative and mitochondrial activity at 9h maturation (P<0.05) and delayed mitochondrial migration. The present study shows the significance of altering PPP activity during bovine oocyte IVM, revealing that there is a link between the activity of the PPP and the oxidative status of the oocyte.

  14. Association of Oxidative Stress Markers with Atherogenic Index of Plasma in Adult Sickle Cell Nephropathy

    Directory of Open Access Journals (Sweden)

    M. A. Emokpae

    2012-01-01

    Full Text Available This paper evaluates the association of oxidative stress and atherogenic index of plasma in order to assess the cardiovascular risk in Sickle cell nephropathy especially as lipoprotein levels are lower in SCD than non-SCD patients. Antioxidant enzymes, malondialdehyde(MDA, urea, creatinine, and glomerular filtration rate were evaluated in 110 confirmed sickle cell disease patients: 65 males in steady state, aged 21.1±6.0 years, 30 males with macroalbuminuria, aged 24.5±7.0, years and 15 with chronic kidney disease (CKD, aged 31.8±2.0 years. The mean activity levels of glutathione peroxidase (GPx, superoxide dismutase (Cu/ZnSOD, and catalase (CAT were significantly lower (P<0.001 in SCD with macroalbuminuria and CKD while MDA was higher (P<0.001 in SCD with macroalbuminuria and CKD compared with controls. There was negative correlation between GPx (P<0.001, Cu/ZnSOD (P<0.02, and Atherogenic index of plasma in SCD with CKD, while MDA shows a positive correlation (P<0.001 with AIP in SCD with CKD. There was however no correlation between CAT and AIP. Decreased activity levels of antioxidant enzymes and low HDL-cholesterol concentration were confirmed in adult SCD with CKD in Nigerians. The increase oxidative stress and high atherogenic index in CKD may accelerate the process of cardiovascular complications in adult SCD patients. Atherogenic index of plasma was negatively correlated with antioxidant enzymes and positively with MDA.

  15. Oxidant and enzymatic antioxidant status (gene expression and activity) in the brain of chickens with cold-induced pulmonary hypertension

    Science.gov (United States)

    Hassanpour, Hossein; Khalaji-Pirbalouty, Valiallah; Nasiri, Leila; Mohebbi, Abdonnaser; Bahadoran, Shahab

    2015-11-01

    To evaluate oxidant and antioxidant status of the brain (hindbrain, midbrain, and forebrain) in chickens with cold-induced pulmonary hypertension, the measurements of lipid peroxidation, protein oxidation, antioxidant capacity, enzymatic activity, and gene expression (for catalase, glutathione peroxidase, and superoxide dismutases) were done. There were high lipid peroxidation/protein oxidation and low antioxidant capacity in the hindbrain of cold-induced pulmonary hypertensive chickens compared to control ( P hypertensive chickens, superoxide dismutase activity was decreased (forebrain, midbrain, and hindbrain), while catalase activity was increased (forebrain and midbrain) ( P hypertensive chickens. Probably, these situations in the oxidant and antioxidant status of the brain especially hindbrain may change its function at cardiovascular center and sympathetic nervous system to exacerbate pulmonary hypertension.

  16. Status of Issues in U.S. Edge-Plasma Research and Priority Topics for the Next Five Years

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, G; Chang, C; Fenstermacher, M; Guzdar, P; Hahm, T S; Krasheninnikov, S; Kritz, A; Rognlien, T D; Schnack, D; Schultz, D; Snyder, P; Stotler, D; Terry, J; Ulrickson, M; Bolton, C

    2005-03-16

    The Edge Coordinating Committee (ECC) was formed in July 14-15, 2004 when OFES Theory Team invited 14 plasma researchers to a two-day meeting in Germantown, MD to discuss the state of edge-plasma research in the U.S. with a focus on theory and modeling (see http://www.mfescience.org/ecc/ ecc/). At that time, OFES tasked the ECC with providing, in about a six month period, a report on the present status of key issues in this area together with a roadmap of what range of activities should be undertaken in the next five years to resolve these issues. This document is a response to that charge. Future edge-plasma research described here is assumed to fit into a budget constraint of a ''flat budget,'' with some additional activities cited for budget increases of as much as 50%. To obtain some measure of the relative fraction of OFES Theory funding presently devoted to edge plasma research, the OFES Theory Team informally surveyed funded work they support in this area at National Labs, Universities, and industry. John Mandrekas reported to us that approximately 10% of the present budget goes to edge-physics areas at 10 institutions, for a total of {approx}$2.5M each year. While not explicitly estimated, we note that there are also important edge plasma projects in the Plasma Technology program, especially related to plasma/material sputtering interactions, near-surface plasma chemistry and transport, and impurity transport. Likewise, the Confinement Program has important efforts in interpreting edge-plasma data through modeling codes. This initial status/roadmap work of the ECC is complimentary to the Fusion Energy Science Sciences Advisory Committee (FESAC) Panel on Program Priorities (see http://www.mfescience.org/fesac/ fesac/). This Panel is charged with identifying major science and technology issues for all of controlled fusion and also with recommending campaigns to address these issues. The Panel has organized their report along six thematic

  17. Artificial light at night affects body mass but not oxidative status in free-living nestling songbirds: an experimental study

    Science.gov (United States)

    Raap, Thomas; Casasole, Giulia; Costantini, David; Abdelgawad, Hamada; Asard, Han; Pinxten, Rianne; Eens, Marcel

    2016-10-01

    Artificial light at night (ALAN), termed light pollution, is an increasingly important anthropogenic environmental pressure on wildlife. Exposure to unnatural lighting environments may have profound effects on animal physiology, particularly during early life. Here, we experimentally investigated for the first time the impact of ALAN on body mass and oxidative status during development, using nestlings of a free-living songbird, the great tit (Parus major), an important model species. Body mass and blood oxidative status were determined at baseline (=13 days after hatching) and again after a two night exposure to ALAN. Because it is very difficult to generalise the oxidative status from one or two measures we relied on a multi-biomarker approach. We determined multiple metrics of both antioxidant defences and oxidative damage: molecular antioxidants GSH, GSSG; antioxidant enzymes GPX, SOD, CAT; total non-enzymatic antioxidant capacity and damage markers protein carbonyls and TBARS. Light exposed nestlings showed no increase in body mass, in contrast to unexposed individuals. None of the metrics of oxidative status were affected. Nonetheless, our study provides experimental field evidence that ALAN may negatively affect free-living nestlings’ development and hence may have adverse consequences lasting throughout adulthood.

  18. A comparative study of oxidant-antioxidant status in stable and active vitiligo patients.

    Science.gov (United States)

    Ines, Dammak; Sonia, Boudaya; Riadh, Ben Mansour; Amel, El Gaied; Slaheddine, Marrekchi; Hamida, Turki; Hamadi, Attia; Basma, Hentati

    2006-09-01

    The pathogenetic mechanisms in vitiligo have not been completely clarified. One of the major hypotheses in the pathogenesis of vitiligo is the oxidative stress hypothesis. The active or stable phase of vitiligo is defined on the basis of the progression or appearance of new lesions in the last 3 months and the absence of new lesions or their progression in the last 6 months, respectively. Eighteen patients with active vitiligo, 18 patients with stable vitiligo, and 40 controls were included in this study. We examined serum levels of malondialdehyde, selenium, vitamin E and A, and the erythrocyte activities of glutathione peroxidase, superoxide dismutase, and catalase. Our results revealed a significantly higher level of serum malondialdehyde, selenium in patients with active disease compared with the controls. Significant higher increase in erythrocytes superoxide dismutase activities was observed in active vitiligo group, erythrocyte glutathione peroxidase activity was decreased significantly in active disease, whereas erythrocyte catalase activity and plasma vitamin E and A levels were not different in vitiligo patients as compared with controls. Our study shows that oxidative stress is involved in the pathophysiology of both active and stable vitiligo but increased imbalance of antioxidants was observed in the blood of active vitiligo patients.

  19. Total antioxidant capacity and total oxidant status in saliva of periodontitis patients in relation to bacterial load

    OpenAIRE

    2016-01-01

    The detection of salivary biomarkers has a potential application in early diagnosis and monitoring of periodontal inflammation. However, searching sensitive salivary biomarkers for periodontitis is still ongoing. Oxidative stress is supposed to play an important role in periodontitis progression and tissue destruction. In this cross-sectional study, we investigated total antioxidant capacity (TAC) and total oxidant status (TOS) in saliva of periodontitis patients compared to healthy controls ...

  20. Plasma-based ambient mass spectrometry techniques: The current status and future prospective.

    Science.gov (United States)

    Ding, Xuelu; Duan, Yixiang

    2015-01-01

    Plasma-based ambient mass spectrometry is emerging as a frontier technology for direct analysis of sample that employs low-energy plasma as the ionization reagent. The versatile sources of ambient mass spectrometry (MS) can be classified according to the plasma formation approaches; namely, corona discharge, glow discharge, dielectric barrier discharge, and microwave-induced discharge. These techniques allow pretreatment-free detection of samples, ranging from biological materials (e.g., flies, bacteria, plants, tissues, peptides, metabolites, and lipids) to pharmaceuticals, food-stuffs, polymers, chemical warfare reagents, and daily-use chemicals. In most cases, plasma-based ambient MS performs well as a qualitative tool and as an analyzer for semi-quantitation. Herein, we provide an overview of the key concepts, mechanisms, and applications of plasma-based ambient MS techniques, and discuss the challenges and outlook.

  1. Reducing Dietary Cation-Anion Difference on Acid-Base Balance, Plasma Minerals Level and Anti-Oxidative Stress of Female Goats

    Institute of Scientific and Technical Information of China (English)

    WU Wen-xuan; YANG Yi; ZHANG Ji-kun; LI Sheng-li

    2013-01-01

    Reducing dietary cation-anion difference (DCAD) has been proved an effective way to prevent milk fever in dairy cows. Based on the similar physiological gastro-intestinal tract anatomy and metabolic process between female goats and dairy cows, this study was conducted to evaluate the effects of varying DCAD on fluid acid-base status, plasma minerals concentration and anti-oxidative stress capacity of female goats. Urinary pH, plasma Ca, P and Mg;and anti-oxidative stress indices of total superoxide dismutase (T-SOD), hydrogen peroxide (H2O2), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) were determined to evaluate the effect. Forty-eight Guizhou black female goats ((15±1.9) mon of old, (22.3±3.75) kg of BW) were randomly allocated to 4 blocks of 12 goats each and were fed 1 of 4 diets differed in DCAD level (calculated as Na+K-Cl-S, mEq kg-1 DM). Levels of DCAD were preliminarily designed to be control (+150 mEq kg-1 DM, CON), high DCAD (+300 mEq kg-1 DM, HD), low DCAD (0 mEq kg-1 DM, LD) and negative DCAD (-150 mEq kg-1 DM, ND), respectively. A commercial anionic salts (Animate) and sodium bicarbonate (NaHCO3) were supplemented to reduce and increase DCAD level, respectively. There was no difference in dry matter intake for 4 groups of goats. Urine pH was aggressively decreased (P0.05) plasma Mg level. There was no significant (P>0.05) difference in plasma GSH-Px activity and H2O2, but anionic salts supplementation in LD and ND significantly increased (P<0.05) plasma T-SOD activity and tended to reduce MDA (P<0.1) over HD and CON. Results from this study indicated that reducing DCAD could decrease urine pH and increase plasma Ca concentration of female goats. Additionally, reducing DCAD was helpful to enhance anti-oxidative stress capability of female goats.

  2. Serum oxidant and antioxidant status in adolescents undergoing professional endurance sports training.

    Science.gov (United States)

    Tong, Tom K; Lin, Hua; Lippi, Giuseppe; Nie, Jinlei; Tian, Ye

    2012-01-01

    This study evaluated the impact of professional training on serum oxidant and antioxidant status in adolescent endurance athletes and compared it with that of untrained individuals. Firstly, serum thiobarbituric-acid-reactive substances (TBARSs), xanthine oxidase (XO), catalase (CAT), reduced glutathione (GSH), superoxide dismutase (SOD), and total antioxidant capacity (T-AOC) were measured in 67 male runners, cyclists, and untrained adolescents. Seven-day dietary intakes were also assessed. Secondly, for age- and Tanner-stage-matched comparison, 36 out of the 67 subjects (12 for each group) were then selected and investigated. In cyclists, XO, GSH, and CAT were higher as compared with runners and controls. The CAT in runners, but not GSH and XO, was also higher than in controls. TBARS, T-AOC, and SOD did not differ among the study populations. Regarding the inter-individual relationships among serum redox statuses and dietary nutrient intakes, significant correlations were noted in CAT versus carbohydrates, protein, magnesium, and manganese; GSH versus carbohydrates, protein, fat, selenium, zinc, iron, and magnesium; XO versus cholesterol; CAT versus GSH. These findings suggest that the resting blood redox balance in the professional adolescent athletes was well maintained partly by the increase of individual antioxidant in adaptation to chronic exercise.

  3. Serum Oxidant and Antioxidant Status in Adolescents Undergoing Professional Endurance Sports Training

    Directory of Open Access Journals (Sweden)

    Tom K. Tong

    2012-01-01

    Full Text Available This study evaluated the impact of professional training on serum oxidant and antioxidant status in adolescent endurance athletes and compared it with that of untrained individuals. Firstly, serum thiobarbituric-acid-reactive substances (TBARSs, xanthine oxidase (XO, catalase (CAT, reduced glutathione (GSH, superoxide dismutase (SOD, and total antioxidant capacity (T-AOC were measured in 67 male runners, cyclists, and untrained adolescents. Seven-day dietary intakes were also assessed. Secondly, for age- and Tanner-stage-matched comparison, 36 out of the 67 subjects (12 for each group were then selected and investigated. In cyclists, XO, GSH, and CAT were higher as compared with runners and controls. The CAT in runners, but not GSH and XO, was also higher than in controls. TBARS, T-AOC, and SOD did not differ among the study populations. Regarding the inter-individual relationships among serum redox statuses and dietary nutrient intakes, significant correlations were noted in CAT versus carbohydrates, protein, magnesium, and manganese; GSH versus carbohydrates, protein, fat, selenium, zinc, iron, and magnesium; XO versus cholesterol; CAT versus GSH. These findings suggest that the resting blood redox balance in the professional adolescent athletes was well maintained partly by the increase of individual antioxidant in adaptation to chronic exercise.

  4. CORRELATION OF PLASMA FIBRINOGEN WITH BLOOD PRESSURE, BMI, LIPID PROFILE AND GLYCEMIC STATUS IN TYPE II D M

    Directory of Open Access Journals (Sweden)

    Suresh

    2014-12-01

    Full Text Available BACKGROUND: Diabetes is the most common metabolic disorder all over the world3.The incidence of diabetes is showing an alarming rise in developing countries, particularly in India. Type 2 diabetes is the most prevalent form in India and constitutes more than 95% of the cases.9 During the past decade, the potential role of haemostatic factors particularly fibrinogen in various disorders and their complication has gained considerable interest. Plasma fibrinogen is a important marker in type 2 Diabetes, but its correlation with smoking, age, sex, hypertension, obesity, family history lipids, has not been evaluated in large studies. In view of paucity of data from Indian studies, we attempt to correlate plasma fibrinogen with blood pressure, BMI, lipid profile and glycemic status in type 2 diabetes mellitus. METHODS: A total of 100, known and newly detected type-2 diabetic patients with and without associated hypertension of more than 40 years of age belonging to both sexes were included. All these patients were registered cases in Basaveshwar Teaching & General Hospital, Gulbarga as outpatients and in-patients. Type-2 diabetic patients associated with myocardial infarction, stroke, chronic inflammatory diseases, tuberculosis, malignancy, secondary hypertension and pregnancy were excluded from this study. After a detailed clinical examination, the following investigations were done: For diabetes mellitus: Random blood sugar, fasting blood sugar, post-prandial blood sugar and glycosylated haemoglobin (ERBA Kit. Renal profile: Blood urea and serum creatinine. Serum lipids: Cholesterol, triglyceride (TG, high density lipoprotein (HDL and low density lipoprotein (LDL by commercially available kits (ERBA Kit. Routine urine examination: Sugar and albumin. Estimation of plasma fibrinogen: The plasma fibrinogen was estimated by thrombin-clotting method by using FIBROQUANT KIT [Tulip Diagnostics (P Ltd.]. OBJECTIVES: To know the fibrinogen levels in patients

  5. Oxidation of metals by a plasma formed as a result of low-threshold breakdown of air

    Science.gov (United States)

    Goncharov, I. N.; Goncharov, Yu N.; Konov, Vitalii I.; Minaev, I. M.; Skvortsov, Yu A.; Chapliev, N. I.

    1981-12-01

    The characteristics of the oxidation of copper, aluminum, and titanium were determined in the case when breakdown of air was initiated by CO2 laser pulses incident on targets made of these metals. A study was made of the influence of surface oxide films on the threshold radiation intensity necessary to produce a plasma. The dependence of the efficiency of the thermal interaction of an optical-breakdown plasma on the magnitude and sign of the charge carried by the surface of a metal target was investigated for the first time in the specific case of titanium.

  6. The Effects of Lithium Administration on Oxidant/Antioxidant Status in Rats: Biochemical and Histomorphological Evaluations.

    Science.gov (United States)

    Toplan, Selmin; Ozdemir, Semra; Tanriverdi, Gamze; Akyolcu, M Can; Ozcelik, Dervis; Darıyerli, Nuran

    2016-02-01

    Present study was planned to determine possible dose-dependent effects of lithium (Li) on oxidant-antioxidant status and histomorphological changes in liver and kidney tissues. For this purpose, twenty-four Wistar male rats were equally divided into three groups: the rats in group I served as controls, drinking tap water without lithium. Groups II and III received 0.1 and 0.2 % lithium carbonate (Li2CO3) through their drinking water, respectively, for 30 days. At the end of the experimental period, lithium concentrations, levels of malondialdehyde (MDA) and glutathione (GSH) and superoxide dismutase (SOD) activities were measured in considered tissues. Histomorphological study was also performed on liver and kidney tissues. Compared to controls, MDA was significantly higher but GSH level lower in groups II and III. SOD activity was higher in group III, but no difference was determined in group II in liver tissue. In kidney tissue, there was no difference determined in MDA and GSH levels between control and experimental groups but SOD activity in groups II and III was significantly higher. In histologic sections of both experimental liver and kidney tissues, specific degenerations were observed. The results of the present study show that treatment with lithium carbonate may result in liver and kidney tissue abnormalities and oxidative damage.

  7. Status of neurocognitive and oxidative stress conditions in iron-steel workers.

    Science.gov (United States)

    Malekirad, Ali Akbar; Mirabdollahi, Mansuoreh; Pilehvarian, Ali Asghar; Nassajpour, Ali Reza; Abdollahi, Mohammad

    2015-07-01

    The aim of this study was to determine oxidative stress status as well as ferrous (Fe) and Copper (Cu) levels in blood, neurocognitive impairment, and clinical markers in iron-steel workers. A comparative cross-sectional analysis was performed in 50 iron-steel workers who have been in contact with Fe and Cu in comparison with a control group containing 50 healthy subjects in the same age group and sex. Blood levels of lipid peroxidation, total antioxidant capacity, Fe, and Cu along with neurocognitive impairment were measured in workers and controls. Clinical examination was accomplished to record any abnormal sign or symptoms. Comparing with controls, the workers showed higher blood levels of lipid peroxidation and Cu and also a lower total antioxidant capacity. There was a positive correlation between work history and interstitial lung disease that strengths the presumption to progress to chronic obstructive lung disease in future. The results indicate that exposure to a combination of Fe and Cu in iron-steel workers induces oxidative stress. Especially, in the present case, toxic effect of Cu has been more than positive effects of Fe, but the combined exposure resulted in no such critical toxicity.

  8. Status of oxidative stress on lesional skin surface of plantar warts.

    Science.gov (United States)

    Arican, O; Ozturk, P; Kurutas, E B; Unsal, V

    2013-03-01

    Warts are abnormal skin growths caused by human papilloma virus (HPV) infections within the skin of the patients. Sometimes the disease is difficult to treatment, and also, the relationship between HPV and some forms of skin cancers is important. The cutaneous oxidative stress status of warts is absent in the literature. To evaluate the role of oxidative stress in affected skin areas in a group of patients with plantar warts. Thirty-six consecutive patients with a diagnosis of plantar warts were enrolled. The samples were obtained by scraping the skin surface. Superoxide dismutase (SOD) and catalase (CAT) activities and malondialdehyde (MDA) levels were measured spectrophotometrically at samples. The SOD activity was significantly lower, and the MDA level was significantly higher on the lesional area than on the non-lesional area (P warts may play a role in pathogenesis of the disease. The addition of topical drugs with antioxidative effects may be valuable in the treatment of warts. © 2012 The Authors. Journal of the European Academy of Dermatology and Venereology © 2012 European Academy of Dermatology and Venereology.

  9. Association of oxidative status and insulin sensitivity in periparturient dairy cattle: an observational study.

    Science.gov (United States)

    Abuelo, A; Hernández, J; Benedito, J L; Castillo, C

    2016-04-01

    Post-parturient insulin resistance (IR) is a common feature in all mammalian animals. However, in dairy cows, it can be exacerbated because of high milk yield, leading to excessive negative energy balance, which is related with increased disease incidence, reduced milk production and worsened reproductive performance. IR has been extensively investigated in humans suffering from diabetes mellitus. In these subjects, it is known that oxidative stress (OS) plays a causative role in the onset of IR. Although OS occurs in transitional dairy cattle, there are yet no studies that investigated the association between IR and OS in dairy cattle. Therefore, the aim of this study was to investigate whether there is a relationship between OS and IR in dairy cattle. Serum samples were taken repeatedly from 22 dairy cows from 2 months prior to the expected calving date to 2 months after calving and were analysed for markers of metabolic and redox balance. Surrogate indices of insulin sensitivity were also calculated. Generalised linear mixed models revealed an effect of the oxidative status on peripheral insulin concentration and on indices of insulin sensitivity. Hence, field trials should investigate the effectiveness of antioxidant therapy on insulin sensitivity in peripheral tissues during the transition period of dairy cattle.

  10. Salidroside protects against kainic acid-induced status epilepticus via suppressing oxidative stress.

    Science.gov (United States)

    Si, Pei-Pei; Zhen, Jun-Li; Cai, Yun-Lei; Wang, Wen-Jing; Wang, Wei-Ping

    2016-04-01

    There are numerous mechanisms by which the brain generates seizures. It is well known that oxidative stress plays a pivotal role in status epilepticus (SE). Salidroside (SDS) extracted from Rhodiola rosea L. shows multiple bioactive properties, such as neuroprotection and antioxidant activity in vitro and in vivo. This study explored the role of SDS in kainic acid (KA)-induced SE and investigated the underlying mechanism. Latency to SE increased in the SDS-pretreated mice compared to the KA group, while the percentage of incidence of SE was significantly reduced. These results suggested that pretreatment with SDS not only delayed SE, but it also decreased the incidence of SE induced by KA. KA increased MDA level and reduced the production of SOD and GSH at multiple timepoints after KA administration. SDS inhibited the change of MDA, SOD and GSH induced by KA prior to SE onset, indicating that SDS protects against KA-induced SE via suppressing oxidative stress. Based on these results, we investigated the possible molecular mechanism of SDS. Pretreatment with SDS reversed the KA-induced decrease in AMP-activated protein kinase (AMPK); increased the sirtuin 1 (SIRT1) deacetylase activity in KA-treated mice, which had no demonstrable effect on SIRT1 mRNA and protein; and suppressed the KA-induced increase in Ace-FoxO1. These results showed that AMPK/SIRT1/FoxO1 signaling is possibly the molecular mechanism of neuroprotection by SDS.

  11. Oxidative stress and innate immunity status in chickens exposed to high dose of ascorbic acid.

    Science.gov (United States)

    Berzina, Nadezhda; Markovs, Jurijs; Dizhbite, Tatiana; Apsite, Mirdza; Vasilyeva, Svetlana; Basova, Nataliya; Smirnova, Galina; Isajevs, Sergejs

    2013-10-01

    The effects of high dose ascorbic acid (10 000 mg·kg(-1) in the diet) and the transition metal on the presence of oxidative stress in the internal organs of growing chicks, as well as on the innate immune system status, were investigated. Supplementation with a high dose of ascorbic acid had pro-inflammatory effects on the intestinal mucosa, and lysozyme levels were decreased significantly in all organs studied. High-dose ascorbic acid caused an imbalance between prooxidative and antioxidative activities and was associated with the generation of semiquinone radicals. We observed that ascorbic acid increased iron and cadmium absorption. When a high dose of ascorbic acid was applied, elevated kidney and intestinal mucosa iron concentrations were observed. The amount of free malondialdehyde in the above organs has increased as well. These data have important implications for the mechanism of the oxidative stress development under the influence of high dose of ascorbic acid, indicating the importance of the side reactions of the mitochondrial electron transport chain with the formation of semiquinone radicals and the role of transition metals in this process.

  12. Haemato-biochemical and oxidative status of buffaloes naturally infected with Trypanosoma evansi.

    Science.gov (United States)

    Pandey, Vijay; Nigam, Rajesh; Jaiswal, Amit Kumar; Sudan, Vikrant; Singh, Rakesh Kumar; Yadav, Pramod Kumar

    2015-09-15

    Blood samples were collected from 05 clinically healthy and 10 adult female water buffaloes naturally infected with Trypanosoma evansi. Confirmation of disease free and infected status of buffaloes was made on clinical signs, observation of T. evansi parasites in the blood smear and duplex PCR based assay. Blood samples were evaluated for levels of haemoglobin (Hb), packed cell volume (PCV), differential leucocytes count (DLC), lipid peroxidation (LPO), calcium, phosphorous, magnesium sodium and potassium and activities of superoxide dismutase (SOD), catalase (CAT), aspartate transaminase (AST), lactate dehydogenase (LDH) and alkaline phosphatase (ALP). The results of the study revealed substantial decrease in levels of Hb, PCV and increase in LPO, SOD, CAT and AST in infected animals compared to healthy animals. However other haematological and biochemical indices did not show significant variations in infected and healthy buffaloes. The enhanced erythrocytic oxidation and reduction of hematological indices, suggests that the enhanced oxidation of the erythrocytes may be a contributory factor in erythrocytic destruction and progression of the anaemia in T. evansi infection in water buffaloes.

  13. Influence of Oxidation Behavior of Feedstock on Microstructure and Ablation Resistance of Plasma-Sprayed Zirconium Carbide Coating

    Science.gov (United States)

    Hu, Cui; Ge, Xuelian; Niu, Yaran; Li, Hong; Huang, Liping; Zheng, Xuebin; Sun, Jinliang

    2015-10-01

    Plasma spray is one of the suitable technologies to deposit carbide coatings with high melting point, such as ZrC. However, in the spray processes performed under atmosphere, oxidation of the carbide powder is inevitable. To investigate the influence of the oxidation behavior of feedstock on microstructure and ablation resistance of the deposited coating, ZrC coatings were prepared by atmospheric and vacuum plasma spray (APS and VPS) technologies, respectively. SiC-coated graphite was applied as the substrate. The obtained results showed that the oxidation of ZrC powder in APS process resulted in the formation of ZrO and Zr2O phases. Pores and cracks were more likely to be formed in the as-sprayed APS-ZrC coating. The VPS-ZrC coating without oxides possessed denser microstructure, higher thermal diffusivity, and lower coefficients of thermal expansion as compared with the APS-ZrC coating. A dense ZrO2 layer would be formed on the surface of the VPS-ZrC-coated sample during the ablation process and the substrate can be protected sufficiently after being ablated in high temperature plasma jet. However, the ZrO2 layer, formed by oxidation of the APS-ZrC coating having loose structure, was easy to be washed away by the shearing action of the plasma jet.

  14. Numerically controlled atmospheric-pressure plasma sacrificial oxidation using electrode arrays for improving silicon-on-insulator layer uniformity

    Science.gov (United States)

    Takei, Hiroyasu; Yoshinaga, Keinosuke; Matsuyama, Satoshi; Yamauchi, Kazuto; Sano, Yasuhisa

    2015-01-01

    Silicon-on-insulator (SOI) wafers are important semiconductor substrates in high-performance devices. In accordance with device miniaturization requirements, ultrathin and highly uniform top silicon layers (SOI layers) are required. A novel method involving numerically controlled (NC) atmospheric-pressure plasma sacrificial oxidation using an electrode array system was developed for the effective fabrication of an ultrathin SOI layer with extremely high uniformity. Spatial resolution and oxidation properties are the key factors controlling ultraprecision machining. The controllability of plasma oxidation and the oxidation properties of the resulting experimental electrode array system were examined. The results demonstrated that the method improved the thickness uniformity of the SOI layer over one-sixth of the area of an 8-in. wafer area.

  15. High-temperature and high-speed oxidation of 4H-SiC by atmospheric pressure thermal plasma jet

    Science.gov (United States)

    Hanafusa, Hiroaki; Ishimaru, Ryosuke; Higashi, Seiichiro

    2017-04-01

    The application of atmospheric pressure thermal plasma jet (TPJ) annealing to the high-temperature and high-speed thermal oxidation of Si-face of 4H-SiC wafer is reported. A high SiO2 film growth rate of 288 nm min‑1 was obtained at an oxidation temperature of 1640 °C without intentional dry O2 gas feeding. Ambient analysis suggested that ozone generated from oxygen in the ambient air by the plasma irradiation was supplied to the SiC surface. It is implied that a mono-oxygen decomposed from ozone was diffused into the oxide growth interface. As a result, high-speed oxidation occurred by combination of high-temperature TPJ annealing and ozone feeding.

  16. Oxidant/antioxidant status in obese adolescent females with acne vulgaris

    Directory of Open Access Journals (Sweden)

    Abulnaja Khalid

    2009-01-01

    Full Text Available Background and Objectives: Acne vulgaris is a distressing skin condition, which can carry with it significant psychological disability. Oxidant/antioxidant imbalance leads to increased production of free radicals, that cause many diseases. Some nutrients, along with systemic oxidative stress, have been implicated in acne vulgaris. The goal of the present study was to assess oxidant and antioxidant status in correlation with the incidence of acne vulgaris in adolescent obese females. Materials and Methods: A total of 60 adolescent females (age 16-22 years were divided into four groups (15 each as follows: The first included obese females with acne; the second included obese females without acne; the third included non obese with acne and the fourth included non obese without acne. Fasting serum Malondialdehyde (MDA, β-carotene, and Vitamins A, E, and C were measured. In addition, platelet monoamineoxidase (MAO, and erythrocyte catechol-o-methyltransferase (COMT activities were determined. Results: It was found that serum MDA was statistically significantly decreased in obese and non obese subjects with acne, as compared to those without acne ( P < 0.05, P < 0.001 respectively. In contrast, the levels of β-carotene, vitamins A, E and C and the activity of MAO were significantly decreased in the obese and non obese with acne, as against the obese and non obese without acne. Interpretation: In obese subjects, increased fat content facilitates free radical production and lipid peroxidation, as indicated by increased MDA level, which is scavenged by the antioxidant vitamins. The decreased activity of MAO may be inhibited by free radicals and this causes psychological depression in adolescents. However there were non significant changes in the activity of COMT among the studied groups. Conclusion: The nutritional factors and a weakened antioxidant defense system may interplay, to increase the risk of psychological sequelae in acne vulgaris.

  17. Assessment of oxidant/antioxidant status in saliva of cell phone users.

    Science.gov (United States)

    Khalil, Ahmad M; Abu Khadra, Khalid M; Aljaberi, Ahmad M; Gagaa, Marwan H; Issa, Hamzah S

    2014-06-01

    Hazardous health effects resulting from exposure to radiofrequency electromagnetic radiation (RF-EMR) emitted from cell phones have been reported in the literature. However, the cellular and molecular targets of RF-EMR are still controversial. The aim of this study was to examine the oxidant/antioxidant status in saliva of cell phone users. Saliva samples collected before using a cell phone as well as at the end of 15 and 30 min calls were tested for two commonly used oxidative stress biomarkers: malondialdehyde (MDA) and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-Oxo-dG). The 8-oxo-dG levels were determined by enzyme-linked immunosorbent (ELISA) competitive assay, while the MDA levels were measured using the OxiSelect MDA adduct ELISA Kit. The antioxidant capacity of the saliva was evaluated using the oxygen radical absorption capacity (ORAC) and the hydroxyl radical averting capacity (HORAC) assays according to the manufacture instructions. The mean 8-oxo-dG and the Bradford protein concentrations (ng/ml and mg/ml, respectively) peaked at 15 min. The levels of HORAC, ORAC and MDA progressively increased with time and reached maximum at 30 min. However, there was no significant effect of talking time on the levels of 8-OxodG and MDA. Similarly, there was no statistically significant effect of talking time on the oxygen and hydroxyl radicals averting capacities, (ORAC) and (HORAC), respectively. These findings suggest that there is no relationship between exposure to radio frequency radiation (RFR) and changes in the salivary oxidant/antioxidant profile.

  18. Solid oxide fuel cell electrolytes produced via very low pressure suspension plasma spray and electrophoretic deposition

    Science.gov (United States)

    Fleetwood, James D.

    Solid oxide fuel cells (SOFCs) are a promising element of comprehensive energy policies due to their direct mechanism for converting the oxidization of fuel, such as hydrogen, into electrical energy. Both very low pressure plasma spray and electrophoretic deposition allow working with high melting temperature SOFC suspension based feedstock on complex surfaces, such as in non-planar SOFC designs. Dense, thin electrolytes of ideal composition for SOFCs can be fabricated with each of these processes, while compositional control is achieved with dissolved dopant compounds that are incorporated into the coating during deposition. In the work reported, sub-micron 8 mole % Y2O3-ZrO2 (YSZ) and gadolinia-doped ceria (GDC), powders, including those in suspension with scandium-nitrate dopants, were deposited on NiO-YSZ anodes, via very low pressure suspension plasma spray (VLPSPS) at Sandia National Laboratories' Thermal Spray Research Laboratory and electrophoretic deposition (EPD) at Purdue University. Plasma spray was carried out in a chamber held at 320 - 1300 Pa, with the plasma composed of argon, hydrogen, and helium. EPD was characterized utilizing constant current deposition at 10 mm electrode separation, with deposits sintered from 1300 -- 1500 °C for 2 hours. The role of suspension constituents in EPD was analyzed based on a parametric study of powder loading, powder specific surface area, polyvinyl butyral (PVB) content, polyethyleneimine (PEI) content, and acetic acid content. Increasing PVB content and reduction of particle specific surface area were found to eliminate the formation of cracks when drying. PEI and acetic acid content were used to control suspension stability and the adhesion of deposits. Additionally, EPD was used to fabricate YSZ/GDC bilayer electrolyte systems. The resultant YSZ electrolytes were 2-27 microns thick and up to 97% dense. Electrolyte performance as part of a SOFC system with screen printed LSCF cathodes was evaluated with peak

  19. R&D Status for In-Situ Plasma Surface Cleaning of SRF Cavities at Spallation Neutron Source

    Energy Technology Data Exchange (ETDEWEB)

    S.-H. Kim, M.T. Crofford, M. Doleans, J.D. Mammosser, J. Saunders

    2011-03-01

    The SNS SCL is reliably operating at 0.93 GeV output energy with an energy reserve of 10MeV with high availability. Most of the cavities exhibit field emission, which directly or indirectly (through heating of end groups) limits the gradients achievable in the high beta cavities in normal operation with the beam. One of the field emission sources would be surface contaminations during surface processing for which mild surface cleaning, if any, will help in reducing field emission. An R&D effort is in progress to develop in-situ surface processing for the cryomodules in the tunnel without disassembly. As the first attempt, in-situ plasma processing has been applied to the CM12 in the SNS SRF facility after the repair work with a promising result. This paper will report the R&D status of plasma processing in the SNS.

  20. Assessment of the toxic potential of engineered metal oxide nanomaterials using an acellular model: citrated rat blood plasma.

    Science.gov (United States)

    Gormley, Patrick Thomas; Callaghan, Neal Ingraham; MacCormack, Tyson James; Dieni, Christopher Anthony

    2016-10-01

    Citrated Sprague-Dawley rat blood plasma was used as a biologically relevant exposure medium to assess the acellular toxic potential of two metal oxide engineered nanomaterials (ENMs), zinc oxide (nZnO), and cerium oxide (nCeO2). Plasma was incubated at 37 °C for up to 48 h with ENM concentrations ranging between 0 and 200 mg/L. The degree of ENM-induced oxidation was assessed by assaying for reactive oxygen species (ROS) levels using dichlorofluorescein (DCF), pH, ferric reducing ability of plasma (FRAP), lipase activity, malondialdehyde (MDA), and protein carbonyls (PC). Whereas previous in vitro studies showed linear-positive correlations between ENM concentration and oxidative damage, our results suggested that low concentrations were generally pro-oxidant and higher concentrations appeared antioxidant or protective, as indicated by DCF fluorescence trends. nZnO and nCeO2 also affected pH in a manner dependent on concentration and elemental composition; higher nZnO concentrations maintained a more alkaline pH, while nCeO2 tended to decrease pH. No other biomarkers of oxidative damage (FRAP, MDA, PC, lipase activity) showed changes at any ENM concentration or time-point tested. Differential dissolution of the two ENMs was also observed, where as much as ∼31.3% of nZnO was instantaneously dissolved to Zn(2+ )and only negligible nCeO2 was degraded. The results suggest that the direct oxidative potential of nZnO and nCeO2 in citrated rat blood plasma is low, and that a physiological or immune response is needed to generate appreciable damage biomarkers. The data also highlight the need for careful consideration when selecting a model for assessing ENM toxicity.

  1. Influence of oxidative stress, diaphragm fatigue, and inspiratory muscle training on the plasma cytokine response to maximum sustainable voluntary ventilation.

    Science.gov (United States)

    Mills, Dean E; Johnson, Michael A; McPhilimey, Martin J; Williams, Neil C; Gonzalez, Javier T; Barnett, Yvonne A; Sharpe, Graham R

    2014-04-15

    The influence of oxidative stress, diaphragm fatigue, and inspiratory muscle training (IMT) on the cytokine response to maximum sustainable voluntary ventilation (MSVV) is unknown. Twelve healthy males were divided equally into an IMT or placebo (PLA) group, and before and after a 6-wk intervention they undertook, on separate days, 1 h of (1) passive rest and (2) MSVV, whereby participants undertook volitional hyperpnea at rest that mimicked the breathing and respiratory muscle recruitment patterns commensurate with heavy cycling exercise. Plasma cytokines remained unchanged during passive rest. There was a main effect of time (P ventilation and increases in plasma IL-6 concentration. In conclusion, increases in plasma IL-1β and IL-6 concentrations during MSVV were not due to diaphragm fatigue or DNA damage in PBMC. Increases in plasma IL-6 concentration during MSVV are attenuated following IMT, and the plasma IL-6 response is dependent upon the level of respiratory muscle work and minute ventilation.

  2. Effects of silicate ion concentration on the formation of ceramic oxide layers produced by plasma electrolytic oxidation on Al alloy

    Science.gov (United States)

    Lee, Jung-Hyung; Kim, Seong-Jong

    2017-01-01

    Plasma electrolytic oxidation (PEO) coatings were fabricated on 5083 Al alloy in KOH electrolyte solution with adding various concentrations of Na2SiO3. Changes in voltage-time response and micro-discharge evolution were analyzed, and the surface and cross-section of the resulting coating layer were further characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The results showed that discharge characteristics were evidently changed with different Na2SiO3 concentrations, particularly higher Na2SiO3 concentrations leading to lower dielectric breakdown voltages. It was found that porous surface structure became prevalent with increasing Na2SiO3 concentration. The EDS analysis confirmed the incorporation of Si element in the PEO coatings. The result of XRD analysis revealed that metastable phases such as γ- and η-alumina were produced as a result of PEO, while amorphous phases appeared with excessive Na2SiO3 concentrations (10 and 14 g/L). The coating thickness was significantly increased about 2-8 times with increasing Na2SiO3, almost depending on Na2SiO3 concentration.

  3. Human plasma platelet-activating factor acetylhydrolase. Oxidatively fragmented phospholipids as substrates.

    Science.gov (United States)

    Stremler, K E; Stafforini, D M; Prescott, S M; McIntyre, T M

    1991-06-15

    Human plasma platelet-activating factor (PAF) acetylhydrolase hydrolyzes the sn-2 acetyl residue of PAF, but not phospholipids with long chain sn-2 residues. It is associated with low density lipoprotein (LDL) particles, and is the LDL-associated phospholipase A2 activity that specifically degrades oxidatively damaged phospholipids (Stremler, K. E., Stafforini, D. M., Prescott, S. M., Zimmerman, G. A., and McIntyre, T. M. (1989) J. Biol. Chem. 264, 5331-5334). To identify potential substrates, we synthesized phosphatidylcholines with sn-2 residues from two to nine carbon atoms long, and found the V/k ratio decreased as the sn-2 residue was lengthened: the C5 homolog was 50%, the C6 20%, while the C9 homolog was only 2% as efficient as PAF. However, the presence of an omega-oxo function radically affected hydrolysis: the half-life of the sn-2 9-aldehydic homolog was identical to that of PAF. We oxidized [2-arachidonoyl]phosphatidylcholine and isolated a number of more polar phosphatidylcholines. We treated these with phospholipase C, derivatized the resulting diglycerides for gas chromatographic/mass spectroscopic analysis, and found a number of diglycerides where the m/z ratio was consistent with a series of short to medium length sn-2 residues. We treated the polar phosphatidylcholines with acetylhydrolase and derivatized the products for analysis by gas chromatography/mass spectroscopy. The liberated residues were more polar than straight chain standards and had m/z ratios from 129 to 296, consistent with short to medium chain residues. Therefore, oxidation fragments the sn-2 residue of phospholipids, and the acetylhydrolase specifically degrades such oxidatively fragmented phospholipids.

  4. Aqueous Extract from Hibiscus sabdariffa Linnaeus Ameliorate Diabetic Nephropathy via Regulating Oxidative Status and Akt/Bad/14-3-3γ in an Experimental Animal Model

    Directory of Open Access Journals (Sweden)

    Shou-Chieh Wang

    2011-01-01

    Full Text Available Several studies point out that oxidative stress maybe a major culprit in diabetic nephropathy. Aqueous extract of Hibiscus sabdariffa L. (HSE has been demonstrated as having beneficial effects on anti-oxidation and lipid-lowering in experimental studies. This study aimed at investigating the effects of Hibiscus sabdariffa L. on diabetic nephropathy in streptozotocin induced type 1 diabetic rats. Our results show that HSE is capable of reducing lipid peroxidation, increasing catalase and glutathione activities significantly in diabetic kidney, and decreasing the plasma levels of triglyceride, low-density lipoprotein (LDL and increasing high-density lipoprotein (HDL value. In histological examination, HSE improves hyperglycemia-caused osmotic diuresis in renal proximal convoluted tubules (defined as hydropic change in diabetic rats. The study also reveals that up-regulation of Akt/Bad/14-3-3γ and NF-κB-mediated transcription might be involved. In conclusion, our results show that HSE possesses the potential effects to ameliorate diabetic nephropathy via improving oxidative status and regulating Akt/Bad/14-3-3γ signaling.

  5. Vitamin A status affects the plasma parameters and regulation of hepatic genes in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Li, Yang; Liu, Yang; Chen, Guoxun

    2017-06-01

    Vitamin A (VA) status regulates metabolism in rats. Whether VA status and availability of retinoic acid (RA) contribute to the insulin-regulated hepatic gene expression remains to be determined. Zucker lean rats with VA sufficient (VAS) or VA deficient (VAD) status were treated with streptozotocin (STZ) to induce insulin-dependent diabetes. They were treated with saline (STZ-VAS-C or STZ-VAD-C), RA (STZ-VAS-RA or STZ-VAD-RA), insulin (STZ-VAS-INS or STZ-VAD-INS), or insulin + RA (STZ-VAS-INS + RA or STZ-VAD-INS + RA) for 3 h. Insulin and insulin + RA treatments reduced tail tip blood glucose, raised plasma insulin and suppressed plasma β-hydroxybutyrate levels in both STZ-VAD and STZ-VAS rats. STZ-VAD-INS and STZ-VAD-INS + RA rats had lower plasma glucose levels than STZ-VAD-C rats had. STZ-VAD-INS and STZ-VAD-INS + RA rats had higher plasma leptin level and lower glucagon level than STZ-VAD-C rats did. Insulin treatment induced Gck, Srebp-1c and Fas and suppressed Pck1 expression levels in the liver of STZ-VAS and STZ-VAD rats. Interestingly, insulin treatment inhibited Cyp26a1 expression in STZ-VAD, but not STZ-VAS rats, whereas RA treatment induced it in both. RA treatment induced Gck expression only in STZ-VAD rats. Insulin + RA treatment further induced the Cyp26a1 and Gck expressions in STZ-VAD rats. The Srebp-1c expression levels of STZ-VAD-INS and STZ-VAD-INS + RA rats were higher than that of STZ-VAS-INS and STZ-VAS-INS + RA rats. The changes of Gck mRNA and glucokinase protein were consistent. In STZ-induced diabetic rats, VA is not required for insulin-regulated Gck, Srebp-1c, Fas and Pck1 expression. However, VA status altered responses of certain genes (Cyp26a1 and Srebp-1c) to insulin treatment. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  6. Effects of immune supplementation and immune challenge on oxidative status and physiology in a model bird: implications for ecologists

    NARCIS (Netherlands)

    Crommenacker, van de J.; Horrocks, N.P.C.; Versteegh, M.A.; Tieleman, B.I.; Komdeur, J.; Matson, K.D.

    2010-01-01

    One route to gain insight into the causes and consequences of ecological differentiation is to understand the underlying physiological mechanisms. We explored the relationships between immunological and oxidative status and investigated how birds cope physiologically with the effects of immune-deriv

  7. Analysis of the Oxidative Stress Status in Nonspecific Vaginitis and Its Role in Vaginal Epithelial Cells Apoptosis

    Science.gov (United States)

    Chen, Zhaojie; Zhang, Zhen; Zhang, Haiyan; Xie, Beibei

    2015-01-01

    Nonspecific vaginitis (NSV), also named bacterial vaginosis, is one of the most common genital system diseases in women during their reproductive years. The specific pathogenic mechanism of NSV is not clear yet. Upon the balance alteration, large amount of reactive oxidant species (ROS) is generated and accumulated in the genital tract, and thus resulting in oxidative stress, which has been reported to be an important trigger of mitochondrial pathway cell apoptosis. In this study, the antioxidant secretion level and antioxidant enzyme activity in the vaginal discharge were evaluated to analyze the oxidative status in the vaginal tract of NSV patients. The effect of oxidative stress on the vaginal mucosa epithelial cell apoptosis was then studied. The role of oxidative stress on NSV development was uncovered; thus open new direction for the prevention and treatment of NSV by providing antiradical agents was revealed. PMID:26558281

  8. Analysis of the Oxidative Stress Status in Nonspecific Vaginitis and Its Role in Vaginal Epithelial Cells Apoptosis

    Directory of Open Access Journals (Sweden)

    Zhaojie Chen

    2015-01-01

    Full Text Available Nonspecific vaginitis (NSV, also named bacterial vaginosis, is one of the most common genital system diseases in women during their reproductive years. The specific pathogenic mechanism of NSV is not clear yet. Upon the balance alteration, large amount of reactive oxidant species (ROS is generated and accumulated in the genital tract, and thus resulting in oxidative stress, which has been reported to be an important trigger of mitochondrial pathway cell apoptosis. In this study, the antioxidant secretion level and antioxidant enzyme activity in the vaginal discharge were evaluated to analyze the oxidative status in the vaginal tract of NSV patients. The effect of oxidative stress on the vaginal mucosa epithelial cell apoptosis was then studied. The role of oxidative stress on NSV development was uncovered; thus open new direction for the prevention and treatment of NSV by providing antiradical agents was revealed.

  9. Status of Hollow Cathode Heater Development for the Space Station Plasma Contactor

    Science.gov (United States)

    Soulas, George C.

    1994-01-01

    A hollow cathode-based plasma contactor has been selected for use on the Space Station. During the operation of the plasma contactor, the hollow cathode heater will endure approximately 12000 thermal cycles. Since a hollow cathode heater failure would result in a plasma contactor failure, a hollow cathode heater development program was established to produce a reliable heater. The development program includes the heater design, process documents for both heater fabrication and assembly, and heater testing. The heater design was a modification of a sheathed ion thruster cathode heater. Heater tests included testing of the heater unit alone and plasma contactor and ion thruster testing. To date, eight heaters have been or are being processed through heater unit testing, two through plasma contactor testing and three through ion thruster testing, all using direct current power supplies. Comparisons of data from heater unit performance tests before cyclic testing, plasma contactor tests, and ion thruster tests at the ignition input current level show the average deviation of input power and tube temperature near the cathode tip to be +/-0.9 W and +/- 21 C, respectively. Heater unit testing included cyclic testing to evaluate reliability under thermal cycling. The first heater, although damaged during assembly, completed 5985 ignition cycles before failing. Four additional heaters successfully completed 6300, 6300, 700, and 700 cycles. Heater unit testing is currently ongoing for three heaters which have to date accumulated greater than 7250, greater than 5500, and greater than 5500 cycles, respectively.

  10. Removal of Nitrogen Oxides in Diesel Engine Exhaust by Plasma Assisted Molecular Sieves

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper reports the studies conducted on removal of oxides of nitrogen (NOx) from diesel engine exhaust using electrical discharge plasma combined with adsorbing materials such as molecular sieves. This study is being reported for the first time. The exhaust is taken from a diesel engine of 6 kW under no load conditions. The characteristic behavior of a pulse energized dielectric barrier discharge reactor in the diesel exhaust treatment is reported. The NOx removal was not significant (36%) when the reactor without any packing was used. However, when the reactor was packed with molecular sieves (MS -3A, -4A & -13X), the NOx removal efficiency was increased to 78% particularly at a temperature of 200 o C. The studies were conducted at different temperatures and the results were discussed.

  11. Factors Influencing Plasma Electrolytic Oxidation(PEO) Coatings on Magnesium Alloys: A Review

    Energy Technology Data Exchange (ETDEWEB)

    Shim, Gunchoo [KISTI ReSEAT Program, Daejon (Korea, Republic of)

    2017-05-15

    Magnesium alloys, which possess excellent specific strength and castability, are highly susceptible to corrosion. Although anodizing is widely used to resolve this problem, it requires toxic electrolytes and produces relatively thin and weak surface coatings. Recently, plasma electrolytic oxidation (PEO) has emerged as an alternative to anodizing. Although it is derived from conventional anodizing, it uses eco-friendly electrolytes and forms thicker, denser, and harder coatings on the surface of magnesium alloys. However, PEO is a complex process involving physical, chemical, and electrochemical reactions, and it is influenced by various factors such as the alloy substrate composition, electrolyte/additive composition, and the electrical variables including the mode of power supply, applied voltage/current density, frequency, and duty cycle. In this article, the detailed effects of these parameters on the microstructure and properties of the PEO coatings are reviewed, and methods of improving the coatings are proposed.

  12. Effect of cerium and lanthanum additives on plasma electrolytic oxidation of AZ31 magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    沈德久; 马豪杰; 郭长虹; 蔡景瑞; 李国龙; 何东磊; 杨庆祥

    2013-01-01

    Plasma electrolytic oxidation (PEO) coatings on AZ31 magnesium (Mg) alloy were developed using the aqueous solution with alkaline silicate and sodium hydroxide as a base electrolyte system. The effects of cerium (Ce) nitrate and lanthanum (La) nitrate additives on the voltage response, microstructure, compositions and corrosion resistance of PEO coatings were investigated by scan-ning electron microscopy (SEM), energy-dispersive spectrum (EDS), X-ray diffraction (XRD) and potentiodynamic polarization tests, etc. The results showed that Ce and La additives increased the stable voltage and compactness of the PEO coatings, while, those did not change the compositions of the PEO coatings. The corrosion resistance of the PEO coating obtained in solutions with La nitrate of 0.1 g/L was the best, followed by that with Ce nitrate of 0.1 g/L and that without additives.

  13. Sound Absorption Characteristics of Aluminum Foams Treated by Plasma Electrolytic Oxidation

    Directory of Open Access Journals (Sweden)

    Wei Jin

    2015-11-01

    Full Text Available Open-celled aluminum foams with different pore sizes were fabricated. A plasma electrolytic oxidation (PEO treatment was applied on the aluminum foams to create a layer of ceramic coating. The sound absorption coefficients of the foams were measured by an impedance tube and they were calculated by a transfer function method. The experimental results show that the sound absorption coefficient of the foam increases gradually with the decrease of pore size. Additionally, when the porosity of the foam increases, the sound absorption coefficient also increases. The PEO coating surface is rough and porous, which is beneficial for improvement in sound absorption. After PEO treatment, the maximum sound absorption of the foam is improved to some extent.

  14. The evidence of cathodic micro-discharges during plasma electrolytic oxidation process

    Energy Technology Data Exchange (ETDEWEB)

    Nominé, A., E-mail: alexandre.nomine@univ-lorraine.fr [Institut Jean Lamour, UMR 7198 CNRS, Université de Lorraine, Parc de Saurupt, 54011 Nancy (France); National Institute of Science and Technology “MISiS,” 4, Leninskij Prospekt, Moscow 119049 (Russian Federation); Martin, J.; Noël, C.; Henrion, G.; Belmonte, T. [Institut Jean Lamour, UMR 7198 CNRS, Université de Lorraine, Parc de Saurupt, 54011 Nancy (France); Bardin, I. V.; Kovalev, V. L.; Rakoch, A. G. [National Institute of Science and Technology “MISiS,” 4, Leninskij Prospekt, Moscow 119049 (Russian Federation)

    2014-02-24

    Plasma electrolytic oxidation (PEO) processing of EV31 magnesium alloy has been carried out in fluoride containing electrolyte under bipolar pulse current regime. Unusual PEO cathodic micro-discharges have been observed and investigated. It is shown that the cathodic micro-discharges exhibit a collective intermittent behavior, which is discussed in terms of charge accumulations at the layer/electrolyte and layer/metal interfaces. Optical emission spectroscopy is used to determine the electron density (typ. 10{sup 15} cm{sup −3}) and the electron temperature (typ. 7500 K) while the role of F{sup −} anions on the appearance of cathodic micro-discharges is pointed out.

  15. Environmental friendly plasma electrolytic oxidation of AM60 magnesium alloy and its corrosion resistance

    Institute of Scientific and Technical Information of China (English)

    CAO Fa-he; LIN Long-yong; ZHANG Zhao; ZHANG Jian-qing; CAO Chu-nan

    2008-01-01

    Plasma electrolytic oxidation of Mg-based AM60 alloys was investigated using 50 Hz AC anodizing technique in an alkaline borate solution, which contained a new kind of organic. The anodic film is relatively smooth with some micro pores and cracks, while the anodic film consists of MgO, MgAl2O4 and MgSiO3. The electrochemical behavior of anodic film was studied by electrochemical impedance spectroscopy and potentiodynamic polarization. Polarization results indicate the PEO treatment can decrease corrosion current by 3-4 magnitude compared with blank AM60 alloy. The anodic film presents a good level of corrosion protection for AM60 magnesium alloy, over 272 h of the salt spray test based on ASTM B117. The effect of micro-structure and composition on corrosion protection efficiency was also investigated.

  16. Characterization of Green-Emitting Translucent Zinc Oxide Ceramics Prepared Via Spark Plasma Sintering

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Mei [University of California; DeVito, David M [ORNL; Howe, Jane Y [ORNL; Yang, Xiaocheng [West Virginia University; Giles, Nancy C. [Air Force Institute of Technology; Neal, John S [ORNL; Munir, Zuhair [University of California

    2011-01-01

    Translucent, green-emitting zinc oxide (ZnO) bodies, 19 mm in diameter and 0.72 mm in thickness, have been prepared via spark plasma sintering method. The consolidation of ZnO powders was investigated over the temperature range of 550-1050 C and the pressure range of 55-530 MPa. Samples sintered at temperatures >850 C and pressures of {approx}120 MPa were translucent and had densities of {approx}100%. Samples sintered at 950 C and 130 MPa showed a higher maximum transmittance than the samples sintered at higher or lower temperatures or pressures, with an excellent in-line transmission of 70% in the IR region around 2330 nm. The dense ZnO ceramics exhibited a strong green emission and a weak ultraviolet emission, and the relative intensity of the green emission increased with increasing sintering temperature.

  17. Long-term exposure to electromagnetic radiation from mobile phones and Wi-Fi devices decreases plasma prolactin, progesterone, and estrogen levels but increases uterine oxidative stress in pregnant rats and their offspring.

    Science.gov (United States)

    Yüksel, Murat; Nazıroğlu, Mustafa; Özkaya, Mehmet Okan

    2016-05-01

    We investigated the effects of mobile phone (900 and 1800 MHz)- and Wi-Fi (2450 MHz)-induced electromagnetic radiation (EMR) exposure on uterine oxidative stress and plasma hormone levels in pregnant rats and their offspring. Thirty-two rats and their forty newborn offspring were divided into the following four groups according to the type of EMR exposure they were subjected to: the control, 900, 1800, and 2450 MHz groups. Each experimental group was exposed to EMR for 60 min/day during the pregnancy and growth periods. The pregnant rats were allowed to stand for four generations (total 52 weeks) before, plasma and uterine samples were obtained. During the 4th, 5th, and 6th weeks of the experiment, plasma and uterine samples were also obtained from the developing rats. Although uterine lipid peroxidation increased in the EMR groups, uterine glutathione peroxidase activity (4th and 5th weeks) and plasma prolactin levels (6th week) in developing rats decreased in these groups. In the maternal rats, the plasma prolactin, estrogen, and progesterone levels decreased in the EMR groups, while the plasma total oxidant status, and body temperatures increased. There were no changes in the levels of reduced glutathione, total antioxidants, or vitamins A, C, and E in the uterine and plasma samples of maternal rats. In conclusion, although EMR exposure decreased the prolactin, estrogen, and progesterone levels in the plasma of maternal rats and their offspring, EMR-induced oxidative stress in the uteri of maternal rats increased during the development of offspring. Mobile phone- and Wi-Fi-induced EMR may be one cause of increased oxidative uterine injury in growing rats and decreased hormone levels in maternal rats. TRPV1 cation channels are the possible molecular pathways responsible for changes in the hormone, oxidative stress, and body temperature levels in the uterus of maternal rats following a year-long exposure to electromagnetic radiation exposure from mobile phones and

  18. Intake of up to 3 Eggs/Day Increases HDL Cholesterol and Plasma Choline While Plasma Trimethylamine-N-oxide is Unchanged in a Healthy Population.

    Science.gov (United States)

    DiMarco, Diana M; Missimer, Amanda; Murillo, Ana Gabriela; Lemos, Bruno S; Malysheva, Olga V; Caudill, Marie A; Blesso, Christopher N; Fernandez, Maria Luz

    2017-03-01

    Eggs are a source of cholesterol and choline and may impact plasma lipids and trimethylamine-N-oxide (TMAO) concentrations, which are biomarkers for cardiovascular disease (CVD) risk. Therefore, the effects of increasing egg intake (0, 1, 2, and 3 eggs/day) on these and other CVD risk biomarkers were evaluated in a young, healthy population. Thirty-eight subjects [19 men/19 women, 24.1 ± 2.2 years, body mass index (BMI) 24.3 ± 2.5 kg/m(2)] participated in this 14-week crossover intervention. Participants underwent a 2-week washout with no egg consumption, followed by intake of 1, 2, and 3 eggs/day for 4 weeks each. Anthropometric data, blood pressure (BP), dietary records, and plasma biomarkers (lipids, glucose, choline, and TMAO) were measured during each intervention phase. BMI, waist circumference, systolic BP, plasma glucose, and plasma triacylglycerol did not change throughout the intervention. Diastolic BP decreased with egg intake (P HDL cholesterol (HDL-c) (P HDL-c ratio (P HDL-c, a reduced LDL-c/HDL-c ratio, and increased plasma choline in combination with no change in plasma LDL-c or TMAO concentrations.

  19. Plasma Carotenoids and Biomarkers of Oxidative Stress in Patients with prior Head and Neck Cancer

    Directory of Open Access Journals (Sweden)

    Kathryn J. Hughes

    2009-01-01

    Full Text Available Diets high in fruits and vegetables are generally believed protective against several chronic diseases. One suggested mechanism is a reduction in oxidative stress. The carotenoids, nutrients found in colored fruits and vegetables, possess antioxidant properties in vitro, but their role in humans is less well documented. The aim of this cross-sectional study was to explore the relationships between the most abundant plasma carotenoids (alpha-carotene, beta-carotene, lycopene, lutein, zeaxanthin and beta-cryptoxanthin, as well as grouped carotenoids (total xanthophylls, carotenes and carotenoids, and urinary excretion of the F2-isoprostanes (F2-IsoPs, stable and specific biomarkers of oxidative damage to lipids. Two F2-IsoP measures were utilized: total F2-IsoPs and 8-iso-PGF2α. The study population (N = 52 was drawn from a study among patients curatively treated for early-stage head and neck cancer. Unadjusted linear regression analyses revealed significant inverse associations between plasma lutein, total xanthophylls and both F2-IsoP measures at baseline. After control for potential confounders, all individual and grouped xanthophylls remained inversely associated with the F2-IsoP measures, but none of these associations achieved significance. The carotenes were not inversely associated with total F2-IsoPs or 8-iso-PGF2a concentrations. The finding of consistent inverse associations between individual and grouped xanthophylls, but not individual and grouped carotenes, and F2-IsoPs is intriguing and warrants further investigation.

  20. Plasma electrolytic oxidation coating of synthetic Al-Mg binary alloys

    Energy Technology Data Exchange (ETDEWEB)

    Tarakci, Mehmet, E-mail: mtarakci@gyte.edu.tr

    2011-12-15

    The binary Al-Mg synthetic alloys were prepared in a vacuum/atmosphere controlled furnace with the addition of 0.5, 1, 2, 4, 7, and 15 wt.% pure Mg into pure aluminum as substrate material. The surfaces of the Al-Mg alloys and pure aluminum were coated for 120 min by plasma electrolytic oxidation in the same electrolyte of 12 g/L sodium silicate and 2 g/L KOH in distilled water. The coating was characterized by X-ray diffraction, scanning electron microscopy, profilometry and Vickers microhardness measurements. There regions of loose outer layer, dense inner layer with precipitate like particles of {alpha}-Al{sub 2}O{sub 3} and a thin transition layer were identified for the coated samples. The coating thickness increases from 85 to 150 {mu}m with Mg contents in the alloys. The surface morphology becomes more porous and consequently surface roughness tends to increase with plasma electrolytic oxidation treatment and further with Mg content. The increase in magnesium content reduces the formation of {alpha}-Al{sub 2}O{sub 3} and crystalline mullite phases in the coating and decreases microhardness of coating. The Mg concentration is constant throughout the other loose and dense regions of coating though it gradually decreases in the thin inner region. - Research Highlights: Black-Right-Pointing-Pointer The average thickness of PEO coating of Al-Mg alloys increases with Mg content. Black-Right-Pointing-Pointer The addition of Mg reduces and prevents the formation of {alpha}-Al{sub 2}O{sub 3} and mullite. Black-Right-Pointing-Pointer The surface roughness increases with Mg content in the Al-Mg alloys. Black-Right-Pointing-Pointer The hardness values of the coating decreases with the Mg amount in the substrate. Black-Right-Pointing-Pointer The Mg concentration is constant throughout the main regions of coating.

  1. The plasma membrane redox system: a candidate source of aging-related oxidative stress.

    Science.gov (United States)

    de Grey, Aubrey D N J

    2005-06-01

    The plasma membrane redox system (PMRS) is an electron transport chain in the plasma membrane that transfers electrons from either intra- or extracellular donors to extracellular acceptors. Unlike the superoxide-generating NADPH oxidase of phagocytes and the homologous (but much less active) enzymes found in some other cells, the PMRS is still incompletely characterised at the molecular level. Much is known, however, concerning its function and affinity for both physiological and non-physiological substrates. A role for it in aging, the 'reductive hotspot hypothesis' (RHH), was proposed in 1998 as part of an explanation for the apparently indefinite survival in vivo of cells that have entirely lost mitochondrial respiratory capacity as a result of the accumulation of mitochondrial mutations. Stimulation of the PMRS might allow the cell to maintain redox homeostasis even while continuing to operate the Krebs cycle, which may be advantageous in many ways. However, the PMRS may, like the mitochondrial respiratory chain, be prone to generate superoxide when thus dysregulated - and in this case superoxide would be generated outside the cell, where antioxidant defences are more limited than inside the cell and where much highly oxidisable material is present. Cascades of peroxidation chain reactions initiated by this process may greatly amplify the oxidative stress on the organism that is caused by rare mitochondrially mutant cells. Since such cells increase in abundance with aging (though remaining rare), this is an economical hypothesis to explain the rise in oxidative stress seen in (and generally believed to contribute substantially to) mammalian aging. In an extension of previously published accounts of RHH, I propose here that the lysosomal toxicity of oxidised cholesterol derivatives (oxysterols) may contribute to the toxicity of mitochondrial mutations by affecting lysosomal function in many cell types in the same way as they have been proposed to do in arterial

  2. Effect of dietary linseed oil and Ganoderma lucidum or olive leaves supplementation on fatty acid composition and oxidative status of rabbits

    Directory of Open Access Journals (Sweden)

    Tina Trebušak

    2014-03-01

    Full Text Available The aim of the present study was to evaluate the influence of natural antioxidant supplementation on the oxidative stress induced by a high proportion of polyunsaturated fatty acids (PUFA in rabbit diets. Forty-eight SIKA rabbits (24 male, 24 female were penned individually and after a 5-d adaptation period divided into 4 homogeneous groups (2.58±0.3 kg. The CONT– group received a diet with 60 g/kg palm fat, while the other 3 groups received a diet with 60 g/kg linseed oil which was either unsupplemented (CONT+ or supplemented with 10 g/kg of Ganoderma lucidum (REISHI or 10 g/kg of olive leaves (OLIVE. Rabbits were euthanised at 102 d of age, 22 d after the start of the experiment. Live weight, weight gain, feed intake and feed conversion rate were recorded. The fatty acid composition of back (M. longissimus dorsi and hind leg muscle (thigh muscle, adipose tissue (abdominal fat and liver were determined. To evaluate the oxidative status of rabbits, the malondialdehyde (MDA concentration in the plasma, liver and both muscles was measured. DNA damage in the leukocytes was measured. Linseed oil addition increased the PUFA ratio and decreased the proportion of saturated fatty acids in all tissues (P<0.001, with no detrimental effect on productive performance of rabbits compared to palm fat. Linseed oil also reduced n-6/n-3 PUFA ratio in all tissues (P<0.001. However, linseed oil addition increased the oxidative stress by increasing MDA concentrations in the liver and muscles (P<0.001, but did not affect the plasma MDA concentrations and the extent of DNA damage in the blood leukocytes compared to palm fat. Addition of olive leaves tended to decrease the concentration of MDA in the liver Addition of olive leaves tended to decrease the concentration of MDA in the liver compared to CONT+ (P=0.059, with no effect of Ganoderma lucidum.

  3. Evaluation of Residence Time on Nitrogen Oxides Removal in Non-Thermal Plasma Reactor

    Science.gov (United States)

    Talebizadeh, Pouyan; Rahimzadeh, Hassan; Babaie, Meisam; Javadi Anaghizi, Saeed; Ghomi, Hamidreza; Ahmadi, Goodarz; Brown, Richard

    2015-01-01

    Non-thermal plasma (NTP) has been introduced over the last few years as a promising after- treatment system for nitrogen oxides and particulate matter removal from diesel exhaust. NTP technology has not been commercialised as yet, due to its high rate of energy consumption. Therefore, it is important to seek out new methods to improve NTP performance. Residence time is a crucial parameter in engine exhaust emissions treatment. In this paper, different electrode shapes are analysed and the corresponding residence time and NOx removal efficiency are studied. An axisymmetric laminar model is used for obtaining residence time distribution numerically using FLUENT software. If the mean residence time in a NTP plasma reactor increases, there will be a corresponding increase in the reaction time and consequently the pollutant removal efficiency increases. Three different screw thread electrodes and a rod electrode are examined. The results show the advantage of screw thread electrodes in comparison with the rod electrode. Furthermore, between the screw thread electrodes, the electrode with the thread width of 1 mm has the highest NOx removal due to higher residence time and a greater number of micro-discharges. The results show that the residence time of the screw thread electrode with a thread width of 1 mm is 21% more than for the rod electrode. PMID:26496630

  4. Evaluation of Residence Time on Nitrogen Oxides Removal in Non-Thermal Plasma Reactor.

    Directory of Open Access Journals (Sweden)

    Pouyan Talebizadeh

    Full Text Available Non-thermal plasma (NTP has been introduced over the last few years as a promising after- treatment system for nitrogen oxides and particulate matter removal from diesel exhaust. NTP technology has not been commercialised as yet, due to its high rate of energy consumption. Therefore, it is important to seek out new methods to improve NTP performance. Residence time is a crucial parameter in engine exhaust emissions treatment. In this paper, different electrode shapes are analysed and the corresponding residence time and NOx removal efficiency are studied. An axisymmetric laminar model is used for obtaining residence time distribution numerically using FLUENT software. If the mean residence time in a NTP plasma reactor increases, there will be a corresponding increase in the reaction time and consequently the pollutant removal efficiency increases. Three different screw thread electrodes and a rod electrode are examined. The results show the advantage of screw thread electrodes in comparison with the rod electrode. Furthermore, between the screw thread electrodes, the electrode with the thread width of 1 mm has the highest NOx removal due to higher residence time and a greater number of micro-discharges. The results show that the residence time of the screw thread electrode with a thread width of 1 mm is 21% more than for the rod electrode.

  5. Evaluation of Residence Time on Nitrogen Oxides Removal in Non-Thermal Plasma Reactor.

    Science.gov (United States)

    Talebizadeh, Pouyan; Rahimzadeh, Hassan; Babaie, Meisam; Javadi Anaghizi, Saeed; Ghomi, Hamidreza; Ahmadi, Goodarz; Brown, Richard

    2015-01-01

    Non-thermal plasma (NTP) has been introduced over the last few years as a promising after- treatment system for nitrogen oxides and particulate matter removal from diesel exhaust. NTP technology has not been commercialised as yet, due to its high rate of energy consumption. Therefore, it is important to seek out new methods to improve NTP performance. Residence time is a crucial parameter in engine exhaust emissions treatment. In this paper, different electrode shapes are analysed and the corresponding residence time and NOx removal efficiency are studied. An axisymmetric laminar model is used for obtaining residence time distribution numerically using FLUENT software. If the mean residence time in a NTP plasma reactor increases, there will be a corresponding increase in the reaction time and consequently the pollutant removal efficiency increases. Three different screw thread electrodes and a rod electrode are examined. The results show the advantage of screw thread electrodes in comparison with the rod electrode. Furthermore, between the screw thread electrodes, the electrode with the thread width of 1 mm has the highest NOx removal due to higher residence time and a greater number of micro-discharges. The results show that the residence time of the screw thread electrode with a thread width of 1 mm is 21% more than for the rod electrode.

  6. Graphene Oxide Modulates B Cell Surface Phenotype and Impairs Immunoglobulin Secretion in Plasma Cell.

    Science.gov (United States)

    Xu, Shaohai; Xu, Shengmin; Chen, Shaopeng; Fan, Huadong; Luo, Xun; Yang, Xiaoyao; Wang, Jun; Yuan, Hang; Xu, An; Wu, Lijun

    2016-04-01

    Since discovery, graphene oxide (GO) has been used in all aspects of human life and revealed promising applications in biomedicine. Nevertheless, the potential risks of GO were always being revealed. Although GO was found to induce immune cell death and innate immune response, little is known regarding its toxicity to the specific adaptive immune system that is crucial for protecting against exotic invasion. The B-cell mediated adaptive immune system, which composed of highly specialized cells (B and plasma cell) and specific immune response (antibody response) is the focus in our present study. Using diverse standard immunological techniques, we found that GO modulated B cell surface phenotype, both costimulatory molecules (CD80, CD86 and especially CD40) and antigen presenting molecules (both classical and nonclassical) under the condition without causing cell death. Meanwhile, the terminal differentiated immunoglobulin (Ig) secreting plasma cell was affected by GO, which displayed a less secretion of Ig and more severe ER stress caused by the retention of the secreted form of Ig in cell compartment. The combined data reveal that GO has a particular adverse effect to B cell and the humoral immunity, directly demonstrating the potential risk of GO to the specific adaptive immunity.

  7. Study of the Deburring Process for Low Carbon Steel by Plasma Electrolytic Oxidation

    Science.gov (United States)

    Li, Hongtao; Kan, Jinfeng; Jiang, Bailing; Liu, Yanjie; Liu, Zheng

    2016-08-01

    In an appropriate electrochemical environment, the discrete thermal electron emission could be induced in the micro area due to the uneven distribution of electron flux on the anode surface. Thus an oxygen molecule could be ionized at the liquid-solid interface after collision, and then oxygen plasma with distribution characteristics would be formed. The plasma electrolytic oxidation (PEO) could happen at the liquid-solid interface. In this work, the low carbon steel was used to study the deburring process by PEO at a high frequency (70000 Hz) pulse DC mode. Its burr height H from 3.23 mm to 0.04 mm was removed to form a smooth surface within 6 min. The values of corrosion potential and current density for the untreated sample were -0.667 V and 6.735×10-5 A/cm2, respectively. But for the treated sample, the corrosion potential and current density were relatively lower, -0.354 V and 1.19×10-7 A/cm2. Therefore, PEO was expected to be a new deburring method of carbon steel for the material processing field. supported by National Natural Science Foundation of China (No. 51571114) and Natural Science Foundation of Jiangsu Province, China (No. BK20130935)

  8. Plasma-produced phase-pure cuprous oxide nanowires for methane gas sensing

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Qijin, E-mail: ijin.cheng@xmu.edu.cn; Zhang, Fengyan [School of Energy Research, Xiamen University, Xiamen City, Fujian Province 361005 (China); Yan, Wei [School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052 (Australia); Plasma Nanoscience Laboratories, CSIRO Materials Science and Engineering, Lindfield, New South Wales 2070 (Australia); Randeniya, Lakshman [Plasma Nanoscience Laboratories, CSIRO Materials Science and Engineering, Lindfield, New South Wales 2070 (Australia); Ostrikov, Kostya [Plasma Nanoscience Laboratories, CSIRO Materials Science and Engineering, Lindfield, New South Wales 2070 (Australia); Plasma Nanoscience, School of Physics, The University of Sydney, Sydney, New South Wales 2006 (Australia)

    2014-03-28

    Phase-selective synthesis of copper oxide nanowires is warranted by several applications, yet it remains challenging because of the narrow windows of the suitable temperature and precursor gas composition in thermal processes. Here, we report on the room-temperature synthesis of small-diameter, large-area, uniform, and phase-pure Cu{sub 2}O nanowires by exposing copper films to a custom-designed low-pressure, thermally non-equilibrium, high-density (typically, the electron number density is in the range of 10{sup 11}–10{sup 13} cm{sup −3}) inductively coupled plasmas. The mechanism of the plasma-enabled phase selectivity is proposed. The gas sensors based on the synthesized Cu{sub 2}O nanowires feature fast response and recovery for the low-temperature (∼140 °C) detection of methane gas in comparison with polycrystalline Cu{sub 2}O thin film-based gas sensors. Specifically, at a methane concentration of 4%, the response and the recovery times of the Cu{sub 2}O nanowire-based gas sensors are 125 and 147 s, respectively. The Cu{sub 2}O nanowire-based gas sensors have a potential for applications in the environmental monitoring, chemical industry, mining industry, and several other emerging areas.

  9. Fabrication and electrochemical performance of solid oxide fuel cell components by atmospheric and suspension plasma spray

    Institute of Scientific and Technical Information of China (English)

    XIA Wei-sheng; YANG Yun-zhen; ZHANG Hai-ou; WANG Gui-lan

    2009-01-01

    The theory of functionally graded material (FGM) was applied in the fabrication process of PEN (Positive- Electrolyte-Negative),the core component of solid oxide fuel cell (SOFC).To enhance its electrochemical performance,the functionally graded PEN of planar SOFC was prepared by atmospheric plasma spray (APS).The cross-sectional SEM micrograph and element energy spectrum of the resultant PEN were analyzed.Its interface resistance was also compared with that without the graded layers to investigate the electrochemical performance enhanced by the functionally graded layers.Moreover,a new process,suspension plasma spray (SPS) was applied to preparing the SOFC electrolyte.Higher densification of the coating by SPS,1.61%,is observed,which is helpful to effectively improve its electrical conductivity.The grain size of the electrolyte coating fabricated by SPS is also smaller than that by APS,which is more favourable to obtain the dense electrolyte coatings.To sum up,all mentioned above can prove that the hybrid process of APS and SPS could be a better approach to fabricate the PEN of SOFC stacks,in which APS is for porous electrodes and SPS for dense electrolyte.

  10. Compound Ceramic Coatings Grown by Micro-plasma Oxidation on Ti-6Al-4V Alloy

    Institute of Scientific and Technical Information of China (English)

    XUE Wei; YAO Zhong-ping; JIANG Zhao-hua

    2006-01-01

    Compound ceramics coatings on the Ti-6Al-4V alloy were prepared by the direct current micro-plasma oxidation (MPO) in NaAlO2 solution. The composition and morphology of the coatings were studied with the X-ray diffraction (XRD) and the scanning electron microscopy (SEM), respectively. Inductively coupled plasma atomic emission spectrometer technique was used to analyze the solution features of Ti-6Al-4V alloy in the process of preparation. The results reveal that Al2TiO5 forms in the coatings at the initial stages of MPO reaction, and its content changes rapidly with the reaction continuing: after 20 min, the ceramics coatings are composed of α-Al2O3, γ-Al2O3 and Al2TiO5, but after 40 min, its main composition is of α-Al2O3. The content of Ti in the solution will increase when the MPO time extends, and as will Al in the anode area until, after 30 min, it reaches the maximum and keeps constant from then on. Both substrata of Ti and Al in the electrolyte join the MPO reaction at the initial stage, where the formation of Al2TiO5 happens; but as the MPO reaction prolongs, more and more Al in the electrolyte will take part in the reaction, leading to the appearance of a large amount of Al2O3.

  11. Cytoprotective effects of mild plasma-activated medium against oxidative stress in human skin fibroblasts

    Science.gov (United States)

    Horiba, Minori; Kamiya, Tetsuro; Hara, Hirokazu; Adachi, Tetsuo

    2017-01-01

    Non-thermal atmospheric pressure plasma (NTAPP) has recently been applied to living cells and tissues and has emerged as a novel technology for medical applications. NTAPP affects cells not only directly, but also indirectly with previously prepared plasma-activated medium (PAM). The objective of this study was to demonstrate the preconditioning effects of “mild PAM” which was prepared under relatively mild conditions, on fibroblasts against cellular injury generated by a high dose of hydrogen peroxide (H2O2). We observed the preconditioning effects of mild PAM containing approximately 50 μM H2O2. Hydrogen peroxide needs to be the main active species in mild PAM for it to exert preconditioning effects because the addition of catalase to mild PAM eliminated these effects. The nuclear translocation and recruitment of nuclear factor erythroid 2-related factor 2 (Nrf2) to antioxidant response elements (ARE) in heme oxygenase 1 (HO-1) promoters and the up-regulation of HO-1 were detected in fibroblasts treated with mild PAM. The addition of ZnPP, a HO-1-specific inhibitor, or the knockdown of Nrf2 completely abrogated the preconditioning effects. Our results demonstrate that mild PAM protects fibroblasts from oxidative stress by up-regulating HO-1, and the H2O2-induced activation of the Nrf2-ARE pathway needs to be involved in this reaction. PMID:28169359

  12. Cell adhesion to plasma electrolytic oxidation (PEO) titania coatings, assessed using a centrifuging technique.

    Science.gov (United States)

    Robinson, H J; Markaki, A E; Collier, C A; Clyne, T W

    2011-11-01

    The adhesion of bovine chondrocytes and human osteoblasts to three titania-based coatings, formed by plasma electrolytic oxidation (PEO), was compared to that on uncoated Ti-6Al-4V substrates, and some comparisons were also made with plasma sprayed hydroxyapatite (HA) coatings. This was done using a centrifuge, with accelerations of up to 160,000 g, so as to induce buoyancy forces that created normal or shear stresses at the interface. It is shown that, on all surfaces, it was easier to remove cells under normal loading than under shear loading. Cell adhesion to the PEO coatings was stronger than that on Ti-6Al-4V and similar to that on HA. Cell proliferation rates were relatively high on one of the PEO coatings, which was virtually free of aluminium, but low on the other two, which contained significant levels of aluminium. It is concluded that the Al-free PEO coating offers promise for application to prosthetic implants.

  13. Surface Modification of Graphene Oxides by Plasma Techniques and Their Application for Environmental Pollution Cleanup.

    Science.gov (United States)

    Wang, Xiangxue; Fan, Qiaohui; Chen, Zhongshan; Wang, Qi; Li, Jiaxing; Hobiny, Aatef; Alsaedi, Ahmed; Wang, Xiangke

    2016-02-01

    Graphene oxides (GOs) have come under intense multidisciplinary study because of their unique physicochemical properties and possible applications. The large amount of oxygen-containing functional groups on GOs leads to a high sorption capacity for the removal of various kinds of organic and inorganic pollutants from aqueous solutions in environmental pollution cleanup. However, the lack of selectivity results in difficulty in the selective removal of target pollutants from aqueous solutions in the presence of other coexisting pollutants. Herein, the surface grafting of GOs with special oxygen-containing functional groups using low-temperature plasma techniques and the application of the surface-modified GOs for the efficient removal of organic and inorganic pollutants in environmental pollution are reviewed. This paper gives an account of our research on the application of GO-based nanomaterials in environmental pollution cleanup, including: (1) the synthesis and surface grafting of functional groups on GOs, summarizing various types of low-temperature plasma techniques for the synthesis of graphene/GOs; and (2) the application of graphene/GOs and their composites for the efficient removal of organic and inorganic pollutants from aqueous solutions, including the interaction mechanism according to recently published results.

  14. Synthesis of Nanosized Titanium Oxide and Nitride Through Vacuum Arc Plasma Expansion Technique

    Science.gov (United States)

    Lepeshev, A. A.; Karpov, I. V.; Ushakov, A. V.; Fedorov, L. Yu.; Shaihadinov, A. A.

    2016-12-01

    Physical vapor deposition techniques such vacuum arc plasma deposition — which are very commonly used in thin film technology — appear to hold much promise for the synthesis of nanocrystalline thin films as well as nanoparticles. Monodisperse and spherical titanium oxide (TiO2) and nitride nanoparticles were produced at room temperature as a cluster beam in the gas phase using a cluster-deposition source. Using the basic principles of the gas condensation method, this study has developed vacuum arc nanoparticle synthesis system. We demonstrate that major process deposition parameter is the pressure in the plasma chamber. This is the major advantage of these techniques over thermal evaporation. Our method affords TiN powders with high specific surface areas exceeding 200m2g-1. TEM micrograph of TiO2 nanoparticles prepared at an oxygen pressure of 60Pa show an average particle size of 6nm. TiO2 nanoparticles prepared at an oxygen pressure of 70Pa were observed to not have a reduced average particle size.

  15. Durian Consumption Effect on the Plasma Malondialdehyde Level as Biomarker of Stress Oxidative in Rats

    Directory of Open Access Journals (Sweden)

    Anugrah Aulia Ulil Amri

    2016-03-01

    Full Text Available Background: Excessive consumption of durian (Durio zibethinus Murray in Indonesia is often connected with its effect on health. This study aims to understand the effect of durian consumption to malondialdehyde (MDA in plasma as oxidative stress biomarker. Methods: The study used an experimental research design on animal models, in the Biochemistry and Molecular Biology Department, Faculty of Medicine, Universitas Indonesia, July–August 2012. Thirty two Sprague-Dawley rats were used, divided into four groups: control, treatment week 1, 2, and 3. Each treatment group was given 20 gram durian fruit diluted with water until 20 ml volume per oral, divided into two doses (10 ml each with 4 hours interlude between doses for 1 week, 2 weeks, and 3 weeks. All groups got normal diet and water ad libitum. Plasma MDA level was measured by TBARS method, then analyzed using Kurskal-Wallis and Mann-Whitney tests. Results: Seventeen samples were successfully decapitated (5 for control; 6 for week 1; 3 for week 2; 3 for week 3. Average plasma MDA level for control treatment week 1, 2 and 3 groups were 0.707 nmol/ml, 0.432 nmol/ml, 0.312 nmol/ml, and 0.746 nmol/ml respectively. Data was significant (p<0.05 with p=0.02. Compared with control group, a significant increase occurred in week 1 and 2 groups with p=0.028 and p=0.025 respectively. Conclusions: Results of durian consumption show MDA level significantly decreases in week 1 and 2. However, MDA level dramatically increases exceeding control group level in week 3.

  16. Leptin reduces plasma ANP level via nitric oxide-dependent mechanism.

    Science.gov (United States)

    Yuan, Kuichang; Yu, Jiahua; Shah, Amin; Gao, Shan; Kim, Sun Young; Kim, Sung Zoo; Park, Byung-Hyun; Kim, Suhn Hee

    2010-04-01

    Leptin is a circulating adipocyte-derived hormone that influences blood pressure (BP) and metabolism. This study was designed to define the possible role of leptin in regulation of the atrial natriuretic peptide (ANP) system using acute and chronic experiments. Intravenous infusion of rat leptin (250 microg/kg injection plus 2 microg.kg(-1).min(-1) for 20 min) into Sprague-Dawley rats increased BP by 25 mmHg and decreased plasma level of ANP from 80.3 +/- 3.45 to 51.8 +/- 3.3 pg/ml. Reserpinization attenuated the rise in BP, but not the reduction of plasma ANP during leptin infusion. N(omega)-nitro-l-arginine methyl ester prevented the effects of leptin on the reduction of ANP level. In hyperleptinemic rats that received adenovirus containing rat leptin cDNA (AdCMV-leptin), BP increased during first 2 days and then recovered to control value. Plasma concentration of ANP and expression of ANP mRNA, but not of atrial ANP, in hyperleptinemic rats were lower than in the control groups on the first and second week after administration of AdCMV-leptin. These effects were not observed by the pretreatment with N(omega)-nitro-l-arginine methyl ester. No differences in renal function and ANP receptor density in the kidney were found between hyperleptinemic and control rats. Basal ANP secretion and isoproterenol-induced suppression of ANP secretion from isolated, perfused atria of hyperleptinemic rats were not different from those of other control groups. These data suggest that leptin inhibits ANP secretion indirectly through nitric oxide without changing basal or isoproterenol-induced ANP secretion.

  17. Tailoring the chemical composition and dispersion behavior of fluorinated graphene oxide via CF4 plasma

    Science.gov (United States)

    Zhou, Baoming; Qian, Xiaoming; Li, Mingming; Ma, Jilan; Liu, Liangsen; Hu, Chuansheng; Xu, Zhiwei; Jiao, Xiaoning

    2015-03-01

    Grafting fluorine onto graphene oxide (GO) by CF4 plasma treatment was investigated in this study. An easy, low-cost, and effective synthesis of the high-dispersive fluorinated GO (FGO) with tunable atomic ratio of F/O ( R F/O) has been realized and the R F/O can be readily manipulated just by adjusting the reaction time. The influence of plasma treatment time on the microstructure, morphology, and dispersion of graphene nanosheets was systematically analyzed. X-ray photoelectron spectroscopy analysis confirmed that fluorine has been grafted onto graphene, and the R F/O was gradually increased to 3.54 for the FGO treated for 20 min. Morphology investigation indicated that etching on the edge of GO occurred during the fluorination. The dispersion performance of FGO in water reduced continuously, which in N, N-dimethylacetamide (DMAc) increased firstly and then decreased with the increase in plasma time. The zeta potentials of FGO in DMAc reached the lowest at -28.6 mV when GO was treated for 10 min. The dispersion of FGO in water should be attributed to the decrease of C-O group, while there was a same variation trend of FGO zeta potential in DMAc as the value of C-F content, regardless of R F/O, CF2 group content and CF3 group content. The GO film was super-hydrophilic and the film of FGO treated for 20 min was found to be neither hydrophilic nor hydrophobic.

  18. Spectroscopic study of plasma during electrolytic oxidation of magnesium- and aluminium-alloy

    Science.gov (United States)

    Jovović, J.; Stojadinović, S.; Šišović, N. M.; Konjević, N.

    2012-10-01

    We present the results of an optical emission spectroscopy study of Plasma during Electrolytic Oxidation (PEO) of magnesium- and aluminum-alloy. Plasma electron number density Ne diagnostics is performed either from the Hβ line shape or from the width or shift of non-hydrogenic ion lines of aluminum and magnesium. The line profile analysis of the Hβ suggests presence of two PEO processes characterized by relatively low electron number densities Ne≈1.2×1015 cm-3 and Ne≈2.3×1016 cm-3. Apart from these two low Ne processes, there is the third one related to the ejection of evaporated anode material through micro-discharge channels. This process is characterized by larger electron density Ne=(1.2-1.6)1017 cm-3, which is detected from the shape and shift of aluminum and magnesium singly charged ion lines. Two low Ne values detected from the Hβ and large Ne measured from the widths and shift of ion lines suggest presence of three types of discharges during PEO with aluminum- and magnesium-alloy anode. On the basis of present and earlier results one can conclude that low Ne processes do not depend upon anode material or electrolyte composition.The electron temperature of 4000 K and 33,000 K are determined from relative intensities of Mg I and O II lines, respectively. The attention is drawn to the possibility of Ne application for Te evaluation using Saha equation what is of importance for PEO metal plasma characterization. During the course of this study, difficulties in the analysis of spectral line shapes are encountered and the ways to overcome some of the obstacles are demonstrated.

  19. Development of glucose biosensors based on plasma polymerization-assisted nanocomposites of polyaniline, tin oxide, and three-dimensional reduced graphene oxide

    Science.gov (United States)

    Wu, Shide; Su, Fangfang; Dong, Xiaodong; Ma, Chuang; Pang, Long; Peng, Donglai; Wang, Minghua; He, Linghao; Zhang, Zhihong

    2017-04-01

    A biosensor based on the plasma polyaniline (pPANI)-modified tin oxide and 3D reduced graphene oxide (SnO2@3D-rGO) nanocomposite was fabricated to detect glucose. The SnO2@3D-rGO nanocomposite was synthesized by simultaneously reducing 3D graphene oxide (3D-GO) and translating SnCl4 into SnO2, followed by pPANI modification. The content of amino groups in the SnO2@3D-rGO@pPANI nanocomposites depended on the plasma input powers used in plasma deposition. The SnO2@3D-rGO nanocomposite was important in the electrochemical biosensor to detect glucose. The fabricated biosensor exhibited a much higher sensitivity than that formed from individual components, namely, SnO2@3D-rGO and pPANI. This biosensor demonstrated a low detection limit of 0.047 ng mL-1 (0.26 nM) (S/N = 3) within the concentration range of 0.1 ng mL-1 to 5 μg mL-1. The selectivity, stability, and practicality of the SnO2@3D-rGO@pPANI-based biosensor were observed. In conclusion, the plasma surface-modified nanocomposite is a promising candidate as biosensor for glucose detection and biological diagnosis.

  20. Fe{sub 2}O{sub 3} nanopowders prepared by a thermal plasma process for water oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dongeun; Choi, Yong-Wook; Na, Ye-Seul; Choi, Soo-Suk; Park, Dong-Wha; Choi, Jinsub, E-mail: jinsub@inha.ac.kr

    2015-08-15

    Highlights: • Hematite nanopowders with a high purity were synthesized by a DC thermal plasma process. • Fe{sub 3}O{sub 4} is formed during the formation of Fe{sub 2}O{sub 3} by thermal plasma with iron and oxygen sources. • Hematite nanopowders with a high purity show higher PEC performance compared to mixed oxides. - Abstract: Hematite (Fe{sub 2}O{sub 3}) nanopowders were synthesized from commercially available micro-sized iron powders by a DC thermal plasma process at atmospheric pressure. The micro-sized iron powders were vaporized in the plasma region, after which the plasma processing equipment was rapidly quenched, resulting in the formation of iron nanopowders with a size of less than 100 nm. Subsequently, the iron nanopowders were heated to convert hematite with a high purity, which was then formed into a thin film with a binder for preparation of electrodes for photoelectrochemical water oxidation. Iron oxide nanopowders were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), particle size analysis (PSA) and transmission electron microscopy (TEM). The photoelectrochemical properties of the Fe{sub 2}O{sub 3} film were characterized in 1 M NaOH under AM 1.5 conditions.

  1. Effects of garcinol and guttiferone K isolated from Garcinia cambogia on oxidative/nitrative modifications in blood platelets and plasma.

    Science.gov (United States)

    Kolodziejczyk, Joanna; Masullo, Milena; Olas, Beata; Piacente, Sonia; Wachowicz, Barbara

    2009-11-01

    The effects of garcinol and guttiferone K, two polyisoprenylated benzophenones occurring a food plant called Garcinia cambogia, on oxidative/nitrative protein damage (determined by parameters such as levels of protein carbonyl groups and nitrotyrosine residues) in human blood platelets and plasma after treatment with peroxynitrite (ONOO(-)) were studied in vitro. We also investigated the effects of garcinol and guttiferone K on lipid peroxidation in blood platelets and plasma induced by ONOO(-) (100 microM). Exposure of blood platelets or plasma to peroxynitrite (100 microM) resulted in an increased level of carbonyl groups and nitrotyrosine residues in proteins, and an increase of lipid peroxidation measured by the level of thiobarbituric acid reactive species (TBARS). In the presence of garcinol and guttiferone K (0.1-25 microg/ml), a distinct reduction in the formation of carbonyl groups in plasma and platelet proteins together with the decrease of TBARS caused by 100 microM peroxynitrite, was observed. However, garcinol and guttiferone K did not inhibit plasma and platelet protein nitration induced by peroxynitrite. Polyisoprenylated benzophenones present in human diet such as garcinol or guttiferone K in vitro have protective effects against lipid and protein oxidation and may have some promising effects in vivo because they are good antioxidants in the tested models in vitro. Garcinol and guttiferone K can be also useful as protecting factors against diseases associated with oxidative stress.

  2. Supplementation of iron alone and combined with vitamins improves haematological status, erythrocyte membrane fluidity and oxidative stress in anaemic pregnant women.

    Science.gov (United States)

    Ma, Ai Guo; Schouten, Evert G; Sun, Yong Ye; Yang, Fang; Han, Xiu Xia; Zhang, Feng Zhi; Jiang, Dian Chen; Kok, Frans J

    2010-12-01

    Pregnancy is a condition exhibiting increased susceptibility to oxidative stress, and Fe plays a central role in generating harmful oxygen species. The objective of the present study is to investigate the changes in haematological status, oxidative stress and erythrocyte membrane fluidity in anaemic pregnant women after Fe supplementation with and without combined vitamins. The study was a 2 months double-blind, randomised trial. Pregnant women (n 164) were allocated to four groups: group C was the placebo control group; group I was supplemented daily with 60 mg Fe (ferrous sulphate) daily; group IF was supplemented daily with Fe plus 400 μg folic acid; group IM was supplemented daily with Fe plus 2 mg retinol and 1 mg riboflavin, respectively. After the 2-month trial, Hb significantly increased by 15.8, 17.3 and 21.8 g/l, and ferritin by 2.8, 3.6 and 11.0 μg/l, in the I, IF and IM groups compared with placebo. Polarisation (ρ) and microviscosity (η) decreased significantly in other groups compared with placebo, indicating an increase in membrane fluidity. Significant decreases of ρ and η values compared with group C were 0.033 and 0.959 for group I, 0.037 and 1.074 for group IF and 0.064 and 1.865 for group IM, respectively. In addition, significant increases of glutathione peroxidase activities and decreases of malondialdehyde were shown in all treated groups, as well as increases of plasma retinol and urine riboflavin in group IM. The findings show that supplementation with Fe and particularly in combination with vitamins could improve the haematological status as well as oxidative stress and erythrocyte membrane fluidity.

  3. Characterization of plasma electrolytic oxide formed onAZ91 Mg alloy in KMnO4 electrolyte

    Institute of Scientific and Technical Information of China (English)

    Duck-Young HWANG; Ki-Ryong SHIN; Bongyoung YOO; Dong-Heon LEE; Deok-Yong PARK; Dong-Hyuk SHIN

    2009-01-01

    The aim of this work is to investigate microstructure, corrosion resistance characteristics and nanohardness of the oxide layer on AZ91 Mg alloy by applying different voltage with KMnO4 contained solution. There are lots of closed pores that are filled with another oxide compound compared with the typical surface morphology with pore coated until 350 V of coating voltage. The thickness of oxide layer increases with increasing coating voltage. The oxide layer formed on AZ91 Mg alloy in electrolyte with potassium permanganate consists of MgO and Mn2O3. Corrosion potential of the oxide layer on AZ91 Mg alloy obtained at different plasma electrolytic oxidation(PEO) reaction stages increases with increasing coating voltage. The corrosion resistance of AZ91 Mg alloy depends on the existence of the manganese oxide in the oxide layer. The inner barrier layer composed of the MgO and Mn2O3 may serve as diffusion barrier to enhance the corrosion resistance and may partially explain the excellent anti-corrosion performance in corrosion test. Nanohardness values increase with increasing coating voltage. The increase in the nanohardness may be due to the effect of manganese oxide in the oxide layer on AZ91 Mg alloy coated from electrolyte containing KMnO4.

  4. Study of Nanodispersed Iron Oxides Produced in Steel Drilling by Contracted Electric-Arc Air Plasma Torch

    Institute of Scientific and Technical Information of China (English)

    P. STEFANOV; D. GALANOV; G. VISSOKOV; D. PANEVA; B. KUNEV; I. MITOV

    2008-01-01

    The optimal conditions on the plasma-forming gas flowrate, discharge current and voltage, distance between the plasma-torch nozzle and the metal plate surface for the process of penetration in and vaporization of steel plates by the contracted electric-arc air plasma torch accompanied by water quenching, were determined. The X-ray structural and phase studies as well as M6ssbauer and electron microscope studies on the samples treated were performed. It was demonstrated that the vaporized elemental iron was oxidized by the oxygen present in the air plasma jet to form iron oxides (wiistite, magnetite, hematite), which, depending on their mass ra-tios, determined the color of the iron oxide pigments, namely, beginning from light yellow, through deep yellow, light brown, deep brown, violet, red-violet, to black. A high degree of dispersity of the iron oxides is thus produced, with an averaged diameter of the particles below 500 nm, and their defective crystal structure form the basis of their potential application as components of iron-containing catalysts and pigments.

  5. Study of Nanodispersed Iron Oxides Produced in Steel Drilling by Contracted Electric-Arc Air Plasma Torch

    Science.gov (United States)

    Stefanov, P.; Galanov, D.; Vissokov, G.; Paneva, D.; Kunev, B.; Mitov, I.

    2008-06-01

    The optimal conditions on the plasma-forming gas flowrate, discharge current and voltage, distance between the plasma-torch nozzle and the metal plate surface for the process of penetration in and vaporization of steel plates by the contracted electric-arc air plasma torch accompanied by water quenching, were determined. The X-ray structural and phase studies as well as Mössbauer and electron microscope studies on the samples treated were performed. It was demonstrated that the vaporized elemental iron was oxidized by the oxygen present in the air plasma jet to form iron oxides (wüstite, magnetite, hematite), which, depending on their mass ratios, determined the color of the iron oxide pigments, namely, beginning from light yellow, through deep yellow, light brown, deep brown, violet, red-violet, to black. A high degree of dispersity of the iron oxides is thus produced, with an averaged diameter of the particles below 500 nm, and their defective crystal structure form the basis of their potential application as components of iron-containing catalysts and pigments.

  6. Persistent high levels of plasma oxidized low-density lipoprotein after acute myocardial infarction predict stent restenosis

    NARCIS (Netherlands)

    T. Naruko; M. Ueda; S. Ehara; A. Itoh; K. Haze; N. Shirai; Y. Ikura; M. Ohsawa; H. Itabe; Y. Kobayashi; H. Yamagishi; M. Yoshiyama; J. Yoshikawa; A.E. Becker

    2006-01-01

    Objective-Recently, elevated levels of plasma oxidized low-density lipoprotein (LDL) have been shown to relate to plaque instability in human atherosclerotic lesions. We investigated prospectively patients admitted with acute myocardial infarction (AMI) who underwent primary coronary stenting to eva

  7. Characterization of calcium containing plasma electrolytic oxidation coatings on AM50 magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)