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  1. Total peroxynitrite scavenging capacity of phenylethanoid and flavonoid glycosides from the flowers of Buddleja officinalis.

    Science.gov (United States)

    Tai, Bui Huu; Jung, Bong Yong; Cuong, Nguyen Manh; Linh, Pham Thuy; Tung, Nguyen Huu; Nhiem, Nguyen Xuan; Huong, Tran Thu; Anh, Ngo Thi; Kim, Jeong Ah; Kim, Sang Kyum; Kim, Young Ho

    2009-12-01

    Nine compounds, including six phenylethanoid glycosides: acteoside (1); bioside (2); echinacoside (3); poliumoside (4); phenylethyl glycoside (5); salidroside (6) and three flavonoids; linarin (7); apigenin (8); isorhoifolin (9), were isolated from the flowers of Buddleja officinalis MAXIM. (Buddlejaceae). Chemical structures were confirmed by (1)H-, and (13)C-NMR, and MS spectral methods and compared with those reported in the literature. Antioxidant activities of the methanol and water extracts, and all isolated compounds were evaluated using the total oxidant scavenging capacity (TOSC) assay against peroxynitrite. Results of the assay showed that the phenylethanoid glycosides, a major class of compounds of the flowers of B. officinalis, possess strong antioxidant activity. Of these, acteoside, echinacoside and poliumoside have 9.9-, 9.8- and 9.5-fold TOSC value, respectively, compared with the positive control, Trolox.

  2. Antioxidant Capacity, Radical Scavenging Kinetics and Phenolic ...

    African Journals Online (AJOL)

    Antioxidant Capacity, Radical Scavenging Kinetics and Phenolic Profile of Methanol Extracts of Wild Plants of Southern Sonora, Mexico. EF Moran-Palacio, LA Zamora-Álvarez, NA Stephens-Camacho, GA Yáñez- Farías, A Virgen-Ortiz, O Martínez-Cruz, JA Rosas-Rodríguez ...

  3. Antioxidant Capacity, Radical Scavenging Kinetics and Phenolic ...

    African Journals Online (AJOL)

    HP

    Phenolic Profile of Methanol Extracts of Wild Plants of. Southern Sonora ... plant extracts. Phenolic compounds determination was carried out by high ... Determination of antioxidant capacity ..... In vitro antioxidant and antiproliferative activities ...

  4. Multiple free-radical scavenging capacity in serum

    Science.gov (United States)

    Oowada, Shigeru; Endo, Nobuyuki; Kameya, Hiromi; Shimmei, Masashi; Kotake, Yashige

    2012-01-01

    We have developed a method to determine serum scavenging-capacity profile against multiple free radical species, namely hydroxyl radical, superoxide radical, alkoxyl radical, alkylperoxyl radical, alkyl radical, and singlet oxygen. This method was applied to a cohort of chronic kidney disease patients. Each free radical species was produced with a common experimental procedure; i.e., uv/visible-light photolysis of free-radical precursor/sensitizer. The decrease in free-radical concentration by the presence of serum was quantified with electron spin resonance spin trapping method, from which the scavenging capacity was calculated. There was a significant capacity change in the disease group (n = 45) as compared with the healthy control group (n = 30). The percent values of disease’s scavenging capacity with respect to control group indicated statistically significant differences in all free-radical species except alkylperoxyl radical, i.e., hydroxyl radical, 73 ± 12% (p = 0.001); superoxide radical, 158 ± 50% (p = 0.001); alkoxyl radical, 121 ± 30% (p = 0.005); alkylperoxyl radical, 123 ± 32% (p>0.1); alkyl radical, 26 ± 14% (p = 0.001); and singlet oxygen, 57 ± 18% (p = 0.001). The scavenging capacity profile was illustrated using a radar chart, clearly demonstrating the characteristic change in the disease group. Although the cause of the scavenging capacity change by the disease state is not completely understood, the profile of multiple radical scavenging capacities may become a useful diagnostic tool. PMID:22962529

  5. High throughput assay for evaluation of reactive carbonyl scavenging capacity.

    Science.gov (United States)

    Vidal, N; Cavaille, J P; Graziani, F; Robin, M; Ouari, O; Pietri, S; Stocker, P

    2014-01-01

    Many carbonyl species from either lipid peroxidation or glycoxidation are extremely reactive and can disrupt the function of proteins and enzymes. 4-hydroxynonenal and methylglyoxal are the most abundant and toxic lipid-derived reactive carbonyl species. The presence of these toxics leads to carbonyl stress and cause a significant amount of macromolecular damages in several diseases. Much evidence indicates trapping of reactive carbonyl intermediates may be a useful strategy for inhibiting or decreasing carbonyl stress-associated pathologies. There is no rapid and convenient analytical method available for the assessment of direct carbonyl scavenging capacity, and a very limited number of carbonyl scavengers have been identified to date, their therapeutic potential being highlighted only recently. In this context, we have developed a new and rapid sensitive fluorimetric method for the assessment of reactive carbonyl scavengers without involvement glycoxidation systems. Efficacy of various thiol- and non-thiol-carbonyl scavenger pharmacophores was tested both using this screening assay adapted to 96-well microplates and in cultured cells. The scavenging effects on the formation of Advanced Glycation End-product of Bovine Serum Albumin formed with methylglyoxal, 4-hydroxynonenal and glucose-glycated as molecular models were also examined. Low molecular mass thiols with an α-amino-β-mercaptoethane structure showed the highest degree of inhibitory activity toward both α,β-unsaturated aldehydes and dicarbonyls. Cysteine and cysteamine have the best scavenging ability toward methylglyoxal. WR-1065 which is currently approved for clinical use as a protective agent against radiation and renal toxicity was identified as the best inhibitor of 4-hydroxynonenal.

  6. High throughput assay for evaluation of reactive carbonyl scavenging capacity

    Directory of Open Access Journals (Sweden)

    N. Vidal

    2014-01-01

    Full Text Available Many carbonyl species from either lipid peroxidation or glycoxidation are extremely reactive and can disrupt the function of proteins and enzymes. 4-hydroxynonenal and methylglyoxal are the most abundant and toxic lipid-derived reactive carbonyl species. The presence of these toxics leads to carbonyl stress and cause a significant amount of macromolecular damages in several diseases. Much evidence indicates trapping of reactive carbonyl intermediates may be a useful strategy for inhibiting or decreasing carbonyl stress-associated pathologies. There is no rapid and convenient analytical method available for the assessment of direct carbonyl scavenging capacity, and a very limited number of carbonyl scavengers have been identified to date, their therapeutic potential being highlighted only recently. In this context, we have developed a new and rapid sensitive fluorimetric method for the assessment of reactive carbonyl scavengers without involvement glycoxidation systems. Efficacy of various thiol- and non-thiol-carbonyl scavenger pharmacophores was tested both using this screening assay adapted to 96-well microplates and in cultured cells. The scavenging effects on the formation of Advanced Glycation End-product of Bovine Serum Albumin formed with methylglyoxal, 4-hydroxynonenal and glucose-glycated as molecular models were also examined. Low molecular mass thiols with an α-amino-β-mercaptoethane structure showed the highest degree of inhibitory activity toward both α,β-unsaturated aldehydes and dicarbonyls. Cysteine and cysteamine have the best scavenging ability toward methylglyoxal. WR-1065 which is currently approved for clinical use as a protective agent against radiation and renal toxicity was identified as the best inhibitor of 4-hydroxynonenal.

  7. Scavenging Capacities of Some Wines and Wine Phenolic Extracts

    Directory of Open Access Journals (Sweden)

    Ioannis G. Roussis

    2005-01-01

    Full Text Available The aim of this study was to assess the ability of different wines – a sweet red, a dry red, a sweet white, and a dry white – to scavenge the stable 1,1’-diphenyl-2-picryl-hydrazyl radical (DPPH. and to determine their phenolic composition. Both red wines contained, apart from anthocyanins, also higher concentration of total phenolics, tartaric esters, and flavonols than the two white wines. All wines exhibited scavenging activity analogous to their total phenolic content. However, their phenolics differed in antiradical potency, which was visible in their EC50 values. The dry red wine, Xinomavro, had a lower EC50 value, indicating the higher antiradical potency of its phenolics. The scavenging capacities of phenolic extracts from Xinomavro red wine on hydroxyl radicals, superoxide radicals, and singlet oxygen were also assessed. Wine total extract was fractionated by extraction, and each of the three fractions was then subfractionated by column chromatography into two subfractions. Wine total extract, and its fractions and subfractions exhibited scavenging capacity on hydroxyl radicals, superoxide radicals, and singlet oxygen, indicating the activity of many wine phenolics. The most active wine extracts towards hydroxyl radicals were characterized by the high peaks of flavanols, anthocyanins and flavonols in their HPLC-DAD chromatograms. The most active extract towards superoxide radicals was rich in flavanols and anthocyanins. The characteristic phenolics of the most active wine extracts towards singlet oxygen were flavanols, flavonols and phenolic acids. The ability of all red wine phenolic extracts to scavenge singlet oxygen, along with hydroxyl and superoxide radicals, emphasizes its health functionality.

  8. Scavenger

    DEFF Research Database (Denmark)

    2009-01-01

    Scavenger is one of the cyber foraging frameworks developed in the Locusts project. It has been released as open source software at http://code.google.com/p/scavenger-cf/......Scavenger is one of the cyber foraging frameworks developed in the Locusts project. It has been released as open source software at http://code.google.com/p/scavenger-cf/...

  9. pH-dependent radical scavenging capacity of green tea catechins

    NARCIS (Netherlands)

    Muzolf, M.; Szymusiak, H.; Gliszczynska-Swiglo, A.; Rietjens, I.M.C.M.; Tyrakowska, B.

    2008-01-01

    The effect of pH on the radical scavenging capacity of green tea catechins was investigated using experimental as well as theoretical methods. It was shown that the radical scavenging capacity of the catechins, quantified by the TEAC value, increases with increasing pH of the medium. Comparison of

  10. Radical Scavenging Capacity of Wine Anthocyanins Is Strongly pH-Dependent

    NARCIS (Netherlands)

    Borowski, T.; Tyrakowska, B.; Oszmianski, J.; Rietjens, I.M.C.M.

    2005-01-01

    The radical scavenging capacity of red wine anthocyanins was quantified by the so-called TEAC assay with special emphasis on the influence of pH and conjugation on this activity. The pH appears to be a dominant factor in the radical scavenging capacity of wine anthocyanins, with higher pH values

  11. Multiple free-radical scavenging (MULTIS) capacity in cattle serum.

    Science.gov (United States)

    Sueishi, Yoshimi; Kamogawa, Erisa; Kimura, Anna; Kitahara, Go; Satoh, Hiroyuki; Asanuma, Taketoshi; Oowada, Shigeru

    2017-01-01

    Multiple free-radical scavenging (MULTIS) activity in cattle and human sera was evaluated with electron spin resonance spectroscopy. Scavenging rates against six active species, namely hydroxyl radical, superoxide anion, alkoxyl radical, alkylperoxyl radical, methyl radical, and singlet oxygen were quantified. The difference in the electron spin resonance signal intensity in the presence and absence of the serum was converted into the scavenging rates. Comparative MULTIS measurements were made in sera from eight beef cattle, three fetal calves and fifteen healthy human volunteers. Further, we determined the MULTIS value of albumin, the most abundant component in serum. MULTIS values in cattle sera indicated higher scavenging activity against most free radical species tested than human sera. In particular, cattle serum scavenging activities against superoxide and methyl radical were higher than human serum by 2.6 and 3.7 fold, respectively. In cattle serum, albumin appears to play a dominant role in MULTIS activity, but in human serum that is not the case. Previous data indicated that the abundance of uric acid in bovine blood is nearly 80% less than humans; however, this difference does not explain the deviation in MULTIS profile.

  12. The French Paradox: Determining the Superoxide-Scavenging Capacity of Red Wine and Other Beverages

    Science.gov (United States)

    Logan, Barry A.; Hammond, Matthew P.; Stormo, Benjamin M.

    2008-01-01

    Plant-derived phenolic compounds such as those found in red wine, tea, and certain fruit juices may protect against cardiovascular disease by detoxifying (scavenging) superoxide and other unstable reactive oxygen species. We present a laboratory exercise that can be used to assess the superoxide-scavenging capacity of beverages. Among the…

  13. Scavenging capacity of medicinal plants against free radical-induced cellular damage by radiation and photoactivation

    Energy Technology Data Exchange (ETDEWEB)

    Gadkar, Shalaka [Ruia College, Mumbai (India); Mohan, H [Chemistry Group, Bhabha Atomic Research Centre, Mumbai (India); Kamat, J P [Radiation Biology and Health Science Division, Bhabha Atomic Research Centre, Mumbai (India)

    2004-01-01

    The scavenging capacity of medicinal plants. Andrographis paniculata (Ap) and Swertia chirata (Sc) was examined against cellular damage, induced by radiation and photo-activation in sub-cellular membranes. The results demonstrated significant radical scavenging capacity of the extracts. The rate constants as evaluated by deoxyribose degradation studies and the pulse radiolysis studies carried in presence of ABTS radical well supported the antioxidant properties of the extracts. (author)

  14. Rainwater capacities for BTEX scavenging from ambient air

    Science.gov (United States)

    Šoštarić, A.; Stanišić Stojić, S.; Vuković, G.; Mijić, Z.; Stojić, A.; Gržetić, I.

    2017-11-01

    The contribution of atmospheric precipitation to volatile organic compound (VOC) removal from the atmosphere remains a matter of scientific debate. The aim of this study was to examine the potential of rainwater for benzene, toluene, ethylbenzene and xylene (BTEX) scavenging from ambient air. To that end, air and rainwater samples were collected simultaneously during several rain events that occurred over two distinct time periods in the summer and autumn of 2015. BTEX concentrations in the gaseous and aqueous phases were determined using proton transfer reaction mass spectrometry. The results reveal that the registered amounts of BTEX in rainwater samples were higher than those predicted by Henry's law. Additional analysis, including physico-chemical characterization and source apportionment, was performed and a possible mechanism underlying the BTEX adsorption to the aqueous phase was considered and discussed herein. Finally, regression multivariate methods (MVA) were successfully applied (with relative errors from 20%) to examine the functional dependency of BTEX enrichment factor on gaseous concentrations, physico-chemical properties of rainwater and meteorological parameters.

  15. Antioxidant and Nitrite-Scavenging Capacities of Phenolic Compounds from Sugarcane (Saccharum officinarum L. Tops

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    Jian Sun

    2014-08-01

    Full Text Available Sugarcane tops were extracted with 50% ethanol and fractionated by petroleum ether, ethyl acetate (EtOAc, and n-butyl alcohol successively. Eight phenolic compounds in EtOAc extracts were purified through silica gel and Sephadex LH-20 column chromatographies, and then identified by nuclear magnetic resonance and electrospray ionization mass spectra. The results showed that eight phenolic compounds from EtOAc extracts were identified as caffeic acid, cis-p-hydroxycinnamic acid, quercetin, apigenin, albanin A, australone A, moracin M, and 5'-geranyl-5,7,2',4'-tetrahydroxyflavone. The antioxidant and nitrite-scavenging capacities of different solvent extracts correlated positively with their total phenolic (TP contents. Amongst various extracts, EtOAc extracts possessed the highest TP content and presented the strongest oxygen radical absorbance capacity (ORAC, 1,1'-diphenyl-2-picrylhydrazyl (DPPH radical-scavenging capacity, 2,2'-azobis-3-ethylbenthiaazoline-6-sulfonic acid (ABTS radical-scavenging capacity, ferric reducing antioxidant power (FRAP and nitrite-scavenging capacity. Thus, sugarcane tops could be promoted as a source of natural antioxidant.

  16. Serum Hydroxyl Radical Scavenging Capacity as Quantified with Iron-Free Hydroxyl Radical Source

    Science.gov (United States)

    Endo, Nobuyuki; Oowada, Shigeru; Sueishi, Yoshimi; Shimmei, Masashi; Makino, Keisuke; Fujii, Hirotada; Kotake, Yashige

    2009-01-01

    We have developed a simple ESR spin trapping based method for hydroxyl (OH) radical scavenging-capacity determination, using iron-free OH radical source. Instead of the widely used Fenton reaction, a short (typically 5 seconds) in situ UV-photolysis of a dilute hydrogen peroxide aqueous solution was employed to generate reproducible amounts of OH radicals. ESR spin trapping was applied to quantify OH radicals; the decrease in the OH radical level due to the specimen’s scavenging activity was converted into the OH radical scavenging capacity (rate). The validity of the method was confirmed in pure antioxidants, and the agreement with the previous data was satisfactory. In the second half of this work, the new method was applied to the sera of chronic renal failure (CRF) patients. We show for the first time that after hemodialysis, OH radical scavenging capacity of the CRF serum was restored to the level of healthy control. This method is simple and rapid, and the low concentration hydrogen peroxide is the only chemical added to the system, that could eliminate the complexity of iron-involved Fenton reactions or the use of the pulse-radiolysis system. PMID:19794928

  17. Radical Scavenging Capacity of Methanolic Phillyrea latifolia L. Extract: Anthocyanin and Phenolic Acids Composition of Fruits

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    Naciye Erkan

    2013-01-01

    Full Text Available Radical scavenging capacity of a crude methanolic extract from the fruits of Phillyrea latifolia L., commonly known as green olive tree or mock privet, was investigated with reference to anthocyanin standards, as flavonoids, and phenolic acid standards, as phenylpropanoids. Characterization with high performance liquid chromatography-diode array detection (HPLC-DAD indicated the presence of keracyanin, kuromanin, cyanidin, ferulic acid, caffeic acid and rosmarinic acid at amounts of 289.1, 90.4, 191.4, 225.2, 221.2 and 190.1 mg/100 g fresh weight (FW of fruits, respectively. Chlorogenic and p-coumaric acids were found to exist in lower amounts. Trolox equivalent antioxidant capacity (TEAC and IC50 values of the plant extract were found to be 1.8 mM Trolox equivalents (TE/g FW of fruits and 69.4 µg/mL, respectively, indicating the close radical scavenging activity of the extract to those of keracyanin and p-coumaric acid. The crude methanolic P. latifolia L. fruit extract was seen to be fairly potent in radical scavenging. Total phenolic content (TPC of the plant extract was found to be 1652.9 mg gallic acid equivalent (GAE/100 g FW of fruits.

  18. Rapid high-throughput assay to assess scavenging capacity index using DPPH.

    Science.gov (United States)

    Abderrahim, Fatima; Arribas, Silvia M; Gonzalez, M Carmen; Condezo-Hoyos, Luis

    2013-11-15

    A new microplate-adapted DPPH rapid assay was developed to assess the antioxidant capacity of pure compounds and foods. The assay was carried out in buffered medium (methanol: 10mmol/l Tris buffer pH 7.5, 1:1 v/v) and reaction was completed at 10min. The scavenging capacity index (SCI), a theoretical antioxidant parameter directly related to the antioxidant capacity of samples, was calculated. SCI for pure compounds: gallic acid (6.76±0.08), quercetin (7.89±0.24), catechin (6.05±0.23), trolox (2.32±0.03), ascorbic acid (2.52±0.15) and gluthatione (1.08±0.08) and foods (μmol DPPH scavenged/100ml): tropical juice (655.62±12.18), mediterraneo juice (702.87±11.13), apple juice (212.52±17.22), pomegranate juice (319.83±9.45), red grape nectar (1093.05±18.69), Don Simon orange juice (632.94±17.22) and date syrup (15992.34±250.7) were comparable to those in previous reports using the classic DPPH assay. The relative standard deviation (RSD) for the SCI on the same and different days was less than 8.12% in all cases. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Effect of processing on phenolic acids composition and radical scavenging capacity of barley pasta.

    Science.gov (United States)

    De Paula, Rosanna; Rabalski, Iwona; Messia, Maria Cristina; Abdel-Aal, El-Sayed M; Marconi, Emanuele

    2017-12-01

    Phenolic acids, total phenolics content and DPPH radical scavenging capacity in raw ingredients, fresh and dried spaghetti, and in uncooked and cooked spaghetti were evaluated and compared with semolina spaghetti as a reference. Ferulic acid was the major phenolic acid found in the free and bound phenolic extracts in all the investigated pasta samples. The addition of barley flour into pasta at incorporation levels of 30, 50 and 100% increased phenolic acids and total phenolics content. Pasta processing did not significantly affect the total phenolics content and free radical scavenging capacity, but a significant reduction in total phenolic acids measured by HPLC was found. Drying process differently affected individual phenolic compounds in the free and bound fractions, and thus, the total phenolic acids content. Free vanillic, caffeic and p-coumaric acids did not significantly change, while p-hydroxybenzoic and ferulic acids of the free extracts showed higher values compared to the corresponding fresh pasta. Cooking did not greatly affect total phenolic acids, more leading to conserving free and bound phenolic compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Evaluation of Both Free Radical Scavenging Capacity and Antioxidative Damage Effect of Polydatin.

    Science.gov (United States)

    Jin, Ju; Li, Yan; Zhang, Xiuli; Chen, Tongsheng; Wang, Yifei; Wang, Zhiping

    Cellular damage such as oxidation and lipid peroxidation, and DNA damage induced by free-radicals like reactive oxygen species, has been implicated in several diseases. Radicals generated by 2,2-azobis (2-amidino-propane) dihydrochloride (AAPH) are similar to physiologically active ones. In this study we found that polydatin, a resveratrol natural precursor derived from many sources, has the capacity of free radical scavenging and antioxidative damage. Using free radical scavenging assays, the IC50 values of polydatin were 19.25 and 5.29 μg/ml with the DPPH and the ABTS assay, respectively, and 0.125 mg ferrous sulfate/1 mg polydatin with the FRAP assay. With the AAPH-induced oxidative injury cell model assay, polydatin showed a strong protective effect against the human liver tumor HepG2 cell oxidative stress damage. These results indicate that the antioxidant properties of polydatin have great potential for use as an alternative to more toxic synthetic antioxidants as an additive in food, cosmetics and pharmaceutical preparations for the treatment of oxidative diseases.

  1. Free radical scavenging and total antioxidant capacity of root extracts of Anchomanes difformis Engl. (Araceae).

    Science.gov (United States)

    Aliyu, Abubakar B; Ibrahim, Mohammed A; Musa, Aliyu M; Musa, Aisha O; Kiplimo, Joyce J; Oyewale, Adebayo O

    2013-01-01

    Antioxidants activities from plants sources have attracted a wide range of interest across the world in recent times. This is due to growing concern for safe and alternative sources of antioxidants. The free radical scavenging activity using 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), reducing power assay, total antioxidant capacity of the phosphomolybdenum method and the total phenolics content using the Folin-Ciocalteu reagent were carried out on the acetone, n-butanol and methanol root extracts of Anchomanes difformis. The results of the total phenolics content expressed in mg/100 g of gallic acid equivalent (GAE) showed that the n-butanol extract has significantly (p extracts. All the extracts displayed strong concentration dependent radical scavenging activity. It was also observed that the n-butanol extract showed higher activity of 70.87% and 78.59% at low concentrations of 31.25 microg/mL and 62.5 microg/mL, respectively, than methanol and acetone extracts. The results also showed that the n-butanol extract has strongest reducing ability which is comparable to that of gallic acid at all the concentrations tested. Phytochemical screening on the extracts revealed the presence of flavonoids, saponins, and tannins. The results suggest that n-butanol extract of the plant is very rich in antioxidant compounds worthy of further investigations.

  2. Polyphenol contents and radical scavenging capacities of red maple (Acer rubrum L.) extracts.

    Science.gov (United States)

    Royer, Mariana; Diouf, Papa Niokhor; Stevanovic, Tatjana

    2011-09-01

    The crude ethanol and water extracts of different red maple (Acer rubrum L.) tissues: whole branches (WB), wood of branches (BW), bark of branches (BB), stem bark (SB) and whole twigs (T), were examined in order to determine their phenolic contents as well as their radical scavenging capacities. The total phenols (TP), total extractable tanins (TET) and non-precipitable phenols (NPP), were determined by combination of spectrophotometric and precipitation methods, while total flavonoids, hydroxy cinanmic acids and proanthocyanidins were determined spectrophotometrically. The radical scavenging activities of the extracts were determined against five reactive oxygen species (ROS): superoxide anion (O(2)(·-)), hydroxyl radical (HO(·)), peroxyl radical (ROO(·)), hypochlorite ion (ClO(-)), and hydrogen peroxide (H(2)O(2)) and one reactive nitrogen species (RNS): nitric oxide (NO). The extracts of stem bark were significantly more efficient (exhibiting the highest antioxidant efficiencies, AE) than the other studied extracts against all ROS (at p<0.05, Duncan statistical tests), except against NO. The correlation coefficients determined between total phenolic (TP) content and antiradical efficiencies were R(2)=0.12 for O(2)(·-); R(2)=0.29 for HO(·); R(2)=0.40 for H(2)O(2); R(2)=0.86 for ROO(·); R(2)=0.03 for NO(·) and R(2)=0.73 for ClO(-). Our results indicate potential utilisation of extracts as natural antioxidants. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Antioxidant and Free Radical Scavenging Capacity of Seed and Shell Essential Oils Extracted from Abrus precatorius (L

    Directory of Open Access Journals (Sweden)

    Sunday O. Okoh

    2014-04-01

    Full Text Available Essential oils from plants have been proven safe as natural antioxidants, and few are already marketed as digestive enhancers as well as in prevention of several degenerative diseases. This study evaluated the antioxidant capacity of seed and shell essential oils of Abrus precatorius (L, a herb used for ethno-medicinal practices in Nigeria. The essential oils were obtained by hydro-distillation. The ability of the oils to act as hydrogen/electrons donor or scavenger of radicals were determined by in-vitro antioxidant assays using 2,2-diphenyl-2-picryl-hydrazyl free radical (DPPH. scavenging; 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS radical scavenging; lipid peroxide and nitric oxide radicals scavenging assays. The IC50 of the seed and shell oils (2.10 mg/mL and 1.20 mg/mL respectively showed that antioxidant activity is higher than that for the standard drugs (3.20 mg/mL and 3.40 mg/mL for the nitric oxide scavenging assay. The lipid peroxidation radical activity of the oils were similar to vitamin C, weak DPPH and ABTS radical scavenging activities were discovered in comparison to vitamin C and rutin. Generally, in the four antioxidant assays, a significant correlation existed between concentrations of the oils and percentage inhibition of free radicals and lipid peroxidation. The composition of A. precatorius essential oils reported earlier may account for their antioxidant capacity.

  4. Analysis of Ethyl Acetate Extract of Enzymatic Hydrolysate from High Purity Oleuropein and DPPH Radical Scavenging Capacity

    Science.gov (United States)

    Yuan, Jiaojiao; Li, Bing; Qin, Frank G. F.; Tu, Junling

    2018-01-01

    High purify oleuropein (81.04% OL) was hydrolyzed by hemicellulase and phenols was existed in the ethyl acetate extract of enzymatic hydrolysate (EAE). The results presented that there were hydroxytyrosol (HT), tyrosol, caffeic acid, 3,4-dihydroxybenzoic acid, 3,4-dihydroxy phenylacetic acid in EAE by HPLC, and HT content was 19.36%. Antioxidant activities (DPPH radical scavenging capacity) were all added as the samples concentration increased, and dose-effect relationships also existed. HT possessed the highest DPPH radical scavenging capacity, followed by Vc, and eugenol, OL, caffeic acid, 3,4-dihydroxy phenylacetic acid and 3,4-dihydroxybenzoic acid.

  5. The experimental scavenging capacity and the degradation potential of the mixture of carotenoid and vitamin E, vitamin C

    Science.gov (United States)

    Tuyet, Nguyen Thi Ngoc; Khoa, Tran Anh; Quan, Vu Thi Hong; Chinh, Vuong Ngoc; Phung, Le Thi Kim

    2017-09-01

    The antioxidant capacity of Gac oil can be enhanced by the presence of these other active antioxidants such as vitamin E, vitamin C. Since many of these natural antioxidants are consumed together in foods, the potential for scavenging capacity is high in the human diet. The aim of this study was to determine what concentrations and combinations of antioxidants among Gac oil, vitamin E, vitamin C are capable of producing high scavenging capacity. The fact has resulted in detailed studies of antioxidation capacity of carotenoid of and vitamin. In addition, the antioxidant capacity and degradation potential of the combined mixture of carotenoid and vitamin E, vitamin C were discussed in view of their antioxidant properties as beneficial species in preventing various diseases.

  6. Comparison of Copper Scavenging Capacity between Two Different Red Mud Types

    Science.gov (United States)

    Ma, Yingqun; Si, Chunhua; Lin, Chuxia

    2012-01-01

    A batch experiment was conducted to compare the Cu scavenging capacity between two different red mud types: the first one was a highly basic red mud derived from a combined sintering and Bayer process, and the second one was a seawater-neutralized red mud derived from the Bayer process. The first red mud contained substantial amounts of CaCO3, which, in combination with the high OH− activity, favored the immobilization of water-borne Cu through massive formation of atacamite. In comparison, the seawater-neutralized red mud had a lower pH and was dominated by boehmite, which was likely to play a significant role in Cu adsorption. Overall, it appears that Cu was more tightly retained by the CaCO3-dominated red mud than the boehmite-dominated red mud. It is concluded that the heterogeneity of red mud has marked influences on its capacity to immobilize water-borne Cu and maintain the long-term stability of the immobilized Cu species. The research findings obtained from this study have implications for the development of Cu immobilization technology by using appropriate waste materials generated from the aluminium industry.

  7. Comparison of Copper Scavenging Capacity between Two Different Red Mud Types

    Directory of Open Access Journals (Sweden)

    Yingqun Ma

    2012-09-01

    Full Text Available A batch experiment was conducted to compare the Cu scavenging capacity between two different red mud types: the first one was a highly basic red mud derived from a combined sintering and Bayer process, and the second one was a seawater-neutralized red mud derived from the Bayer process. The first red mud contained substantial amounts of CaCO3, which, in combination with the high OH− activity, favored the immobilization of water-borne Cu through massive formation of atacamite. In comparison, the seawater-neutralized red mud had a lower pH and was dominated by boehmite, which was likely to play a significant role in Cu adsorption. Overall, it appears that Cu was more tightly retained by the CaCO3-dominated red mud than the boehmite-dominated red mud. It is concluded that the heterogeneity of red mud has marked influences on its capacity to immobilize water-borne Cu and maintain the long-term stability of the immobilized Cu species. The research findings obtained from this study have implications for the development of Cu immobilization technology by using appropriate waste materials generated from the aluminium industry.

  8. Evaluation of free radical scavenging capacity and antioxidative damage effect of resveratrol-nanostructured lipid carriers

    Science.gov (United States)

    Jin, Ju; Shi, Fan; Li, Qiu-wen; Li, Pei-shan; Chen, Tong-sheng; Wang, Yi-fei; Wang, Zhi-ping

    2016-03-01

    Cellular damage induced by free-radicals like reactive oxygen species has been implicated in several diseases. 2, 2-azobis(2-amidino-propane) dihydrochloride(AAPH) generates two potent ROS capable of inducing lipid peroxidation: alkoxy radical(RO-) and peroxy radical(ROO-). These radicals are similar to those that are physiologically active and thus might initiate a cascade of intracellular toxic events leading to oxidation, lipid peroxidation, DNA damage and subsequent cell death. Hence naturally anti-oxidant play a vital role in combating these conditions. In this study, resveratrol loaded nanostructured lipid carriers (Res-NLC) was prepared by hot melting and then high pressure homogenization technique. The effects of Res-NLC on free radical scavenging capacity and antioxidative damage is investigated. The particle size and zeta potential of Res-NLC were 139.3 ± 1.7 nm and -11.21 ± 0.41 mV, respectively. By free radical scavenging assays, the IC50 value of Res-NLC were 19.25, 5.29 μg/mL with DPPH, ABTS assay respectively, and 0.161 mg ferrous sulfate/1 mg Res-NLC with FRAP assay; and by AAPH-induced oxidative injury cell model assay, Res-NLC showed the strong protective effect against the human liver tumor HepG2 cell oxidative stress damage. These results indicated that the antioxidant properties of Res-NLC hold great potential used as an alternative to more toxic synthetic antioxidants as an additive in food, cosmetic and pharmaceutical preparations for the oxidative diseases treatment.

  9. Screening of free radical scavenging capacity and antioxidant activities of Rosmarinus officinalis extracts with focus on location and harvesting times

    NARCIS (Netherlands)

    Yesil Celiktas, O.; Girgin, G.; Orhan, H.; Wichers, H.J.; Bedir, E.; Vardar Sukan, F.

    2007-01-01

    Methanolic extracts from the leaves of Rosmarinus officinalis (rosemary) harvested from different locations of Turkey at four different times of the year were analyzed by HPLC, and their radical scavenging capacities and antioxidant activities were studied by various assays. The amounts of carnosol,

  10. Optimization of free radical scavenging capacity and pH of Hylocereus polyrhizus peel by Response Surface Methodology

    Science.gov (United States)

    Putranto, A. W.; Dewi, S. R.; Puspitasari, Y.; Nuriah, F. A.

    2018-03-01

    Red dragon fruit (Hylocereus polyrhizus) peel, a by-product of juice processing, contains a high antioxidant that can be used for nutraceuticals. Hence, it is important to extract and investigate its antioxidant stability. The aim of this study was to optimize the free radical scavenging capacity and pH of H. polyrhizus peel extract using Central Composite Design (CCD) under Response Surface Methodology (RSM). The extraction of H. polyrhizus peel was done by using green-Pulsed Electric Field (PEF)-assisted extraction method. Factors optimized were electric field strength (kV/cm) and extraction time (seconds). The result showed that the correlation between responses (free radical-scavenging capacity and pH) and two factors was quadratic model. The optimum conditions was obtained at the electric field strength of 3.96 kV/cm, and treatment time of 31.9 seconds. Under these conditions, the actual free radical-scavenging capacity and pH were 75.86 ± 0.2 % and 4.8, respectively. The verification model showed that the actual values are in accordance with the predicted values, and have error rate values of free radical-scavenging capacity and pH responses were 0.1% and 3.98%, respectively. We suggest to extract the H. polyrhizus peel using a green and non-thermal extraction technology, PEF-assisted extraction, for research, food applications and nutraceuticals industry.

  11. Cupric ion reducing antioxidant capacity assay for antioxidants in human serum and for hydroxyl radical scavengers.

    Science.gov (United States)

    Apak, Reşat; Güçlü, Kubilay; Ozyürek, Mustafa; Bektaşoğlu, Burcu; Bener, Mustafa

    2010-01-01

    , for which the FRAP (ferric reducing antioxidant potency) test is basically nonresponsive. The additivity of absorbances of all the tested antioxidants confirmed that antioxidants in the CUPRAC test do not chemically interact among each other so as to cause an intensification or quenching of the theoretically expected absorbance, and that a total antioxidant capacity (TAC) assay of serum is possible. As a distinct advantage over other electron-transfer based assays (e.g., Folin, FRAP, ABTS, DPPH), CUPRAC is superior in regard to its realistic pH close to the physiological pH, favorable redox potential, accessibility and stability of reagents, and applicability to lipophilic antioxidants as well as hydrophilic ones. The CUPRAC procedure can also assay hydroxyl radicals, being the most reactive oxygen species (ROS). As a more convenient, efficient, and less costly alternative to HPLC/electrochemical detection techniques and to the nonspecific, low-yield TBARS test, we use p-aminobenzoate, 2,4- and 3,5-dimethoxybenzoate probes for detecting hydroxyl radicals generated from an equivalent mixture of [Fe(II)+EDTA] with hydrogen peroxide. The produced hydroxyl radicals attack both the probe and the water-soluble antioxidants in 37 degrees C-incubated solutions for 2 h. The CUPRAC absorbance of the ethylacetate extract due to the reduction of Cu(II)-neocuproine reagent by the hydroxylated probe decreases in the presence of (.)OH scavengers, the difference being proportional to the scavenging ability of the tested compound. The developed method is less lengthy, more specific, and of a higher yield than the classical TBARS assay.

  12. Scavenging capacity of strawberry tree (Arbutus unedo L.) leaves on free radicals.

    Science.gov (United States)

    Oliveira, Ivo; Coelho, Valentim; Baltasar, Raquel; Pereira, José Alberto; Baptista, Paula

    2009-07-01

    Despite strawberry tree (Arbutus unedo L.) leaves had a long use in traditional medicine due to its antiseptic, diuretic, astringent and depurative properties, the potential of their antioxidant activity are still lacking. Our study goals to assess the antioxidant and free radical scavenging potential of water, ethanol, methanol and diethyl ether extracts of A. unedo leaves. Total phenols content was achieved spectrophotometrically using Folin-Ciocalteau reagent with gallic acid as standard. Antioxidant activity was evaluated using three different methods: reducing power of iron (III)/ferricyanide complex assay, scavenging effect on DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals and scavenging effect on superoxide radicals by using the PMS-NADH-nitroblue tetrazolium system. Ethanol extracts of A. unedo leaves were the highest in reducing power (IC(50) 232.7 microg/mL) and DPPH scavenging effect (IC(50) 63.2 microg/mL) followed by water extracts (with IC(50) of 287.7 and 73.7 microg/mL, respectively); whereas diethyl ether extracts were the lowest. In the scavenging on superoxide radical assay, methanol extracts obtained the best results (IC(50) 6.9 microg/mL). For all the methods tested the antioxidant activity was concentration dependent. In accordance with antioxidant activity, highest total phenols content were found in ethanol, followed by water, methanol and diethyl ether extract. The results indicated that A. unedo leaves are a potential source of natural antioxidants.

  13. Free radical scavenging actions of three Trifolium species in the protection of blood plasma antioxidant capacity in vitro.

    Science.gov (United States)

    Kolodziejczyk-Czepas, Joanna; Nowak, Pawel; Moniuszko-Szajwaj, Barbara; Kowalska, Iwona; Stochmal, Anna

    2015-01-01

    Three clover [Trifolium L. (Leguminosae)] species were selected on the basis of data from traditional medicine, phytochemical profiles, and agricultural significance. The in vitro evaluations of free radical scavenging properties, ferric reducing abilities, and antioxidant effects of extracts from T. pratense L. (crude extract and phenolic fraction), T. pallidum L., and T. scabrum L. (phenolic fractions) were performed. Activities of the Trifolium extracts were determined at their final concentrations of 1.5-50 µg/ml. Free radical scavenging properties of methanol extract solutions were estimated by the reduction of DPPH(•) and ABTS(•) radicals. Measurements of the total antioxidant capacity (TAC) were carried out to assess the antioxidant activities of the extracts in human blood plasma under conditions of oxidative stress, induced by 200 μM peroxynitrite. The phenolic fraction of T. pratense displayed the strongest ABTS(•) and DPPH(•) radical scavenging effects (EC50 value of 21.69 and 12.27 µg/ml, respectively). The EC50 value for T. pallidum extract attained 29.77 and 30.06 µg/ml. The two remaining extracts were less potent scavengers (EC50 value higher than 50 µg/ml). Similar differences were obtained during evaluation of the ferric reducing abilities. Analysis of antioxidant properties of the extracts in blood plasma did not provide such evident differences in their actions, however, it indicated that the T. pratense phenolic fraction displayed the strongest effect. The examined Trifolium extracts partly protected blood plasma and enhanced its non-enzymatic antioxidant defense against harmful action of peroxynitrite in vitro.

  14. Correlation, by multivariate statistical analysis, between the scavenging capacity against reactive oxygen species and the bioactive compounds from frozen fruit pulps

    Directory of Open Access Journals (Sweden)

    Lizziane Cynara Vissotto

    2013-02-01

    Full Text Available The contents of total phenolic compounds (TPC, total flavonoids (TF, and ascorbic acid (AA of 18 frozen fruit pulps and their scavenging capacities against peroxyl radical (ROO•, hydrogen peroxide (H2O2, and hydroxyl radical (•OH were determined. Principal Component Analysis (PCA showed that TPC (total phenolic compounds and AA (ascorbic acid presented positive correlation with the scavenging capacity against ROO•, and TF (total flavonoids showed positive correlation with the scavenging capacity against •OH and ROO• However, the scavenging capacity against H2O2 presented low correlation with TF (total flavonoids, TPC (total phenolic compounds, and AA (ascorbic acid. The Hierarchical Cluster Analysis (HCA allowed the classification of the fruit pulps into three groups: one group was formed by the açai pulp with high TF, total flavonoids, content (134.02 mg CE/100 g pulp and the highest scavenging capacity against ROO•, •OH and H2O2; the second group was formed by the acerola pulp with high TPC, total phenolic compounds, (658.40 mg GAE/100 g pulp and AA , ascorbic acid, (506.27 mg/100 g pulp contents; and the third group was formed by pineapple, cacao, caja, cashew-apple, coconut, cupuaçu, guava, orange, lemon, mango, passion fruit, watermelon, pitanga, tamarind, tangerine, and umbu pulps, which could not be separated considering only the contents of bioactive compounds and the scavenging properties.

  15. Selenium and Zinc content and radical scavenging capacity of edible mushrooms Armilaria mellea and Lycoperdon saccatum

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    Z. Zeković

    2010-01-01

    Full Text Available Armillaria mellea and Lycoperdon saccatum are two delicious mushrooms growing widely trough all Balkan region. Investigation of A. mellea and L. saccatum antioxidant properties includes preparation of mushrooms extracts, determination of Selenium and Zinc content and evaluation of theirs antioxidant activity involving scavenging activity of ˙O2- radicals, DPPH and reducing power assay. Higher extraction yield of 24.48 % has been achieved for L. saccatum, but higher content of Selenium and Zinc was determined in A. mallea extract, 2.359 mg/kg and 50.380 mg/kg, respectively. The radical scavenging activity was found to exhibit 50 % of inhibition value (IC50 value at the extracts concentration of 0.0161±0.0001 mg/ml for the L. saccatum extract and 0.0108±0.0002 mg/ml for A. mallea extract. The determined relative inhibition of ˙O2- radicals for L. sacatum extract is lower than for A. malea. It was determined that both mushrooms extract posses’ reductive capabilities and thus were capable of reducing iron (III.

  16. Free radical-scavenging capacity, antioxidant activity and phenolic content of Pouzolzia zeylanica

    Directory of Open Access Journals (Sweden)

    PEIYUAN LI

    2011-05-01

    Full Text Available Pouzolzia zeylanica was extracted with different solvents (acetone, ethyl acetate and petroleum ether, using different protocols (cold-extraction and Soxhlet extraction. To evaluate the antiradical and antioxidant abilities of the extracts, four in vitro test systems were employed, i.e., DPPH, ABTS and hydroxyl radical scavenging assays and a reducing power assay. All extracts exhibited outstanding antioxidant activities that were superior to that of butylated hydroxytoluene. The ethyl acetate extracts exhibited the most significant antioxidant activities, and cold-extraction under stirring seemed to be the more efficacious method for acquiring the predominant antioxidants. Furthermore, the antioxidant activities and total phenolic (TP content of different extracts followed the same order, i.e., there is a good correlation between antioxidant activities and TP content. The results showed that these extracts, especially the ethyl acetate extracts, could be considered as natural antioxidants and may be useful for curing diseases arising from oxidative deterioration.

  17. FREE RADICAL SCAVENGING CAPACITY OF PAPAVER SOMNIFERUM L. AND DETERMINATION OF PHARMACOLOGICALLY ACTIVE ALKALOIDS USING CAPILLARY ELECTROPHORESIS

    Directory of Open Access Journals (Sweden)

    Marián Valko

    2012-02-01

    Full Text Available The free radical generation is related to the oxidation process in biological systems as well as in foods. It was found that oxidation is affected by antioxidants that can act as radical scavengers. Objective of the present work was to study the free radical scavenging capacity of opium poppy (Papaver somniferum L. extract by using the DPPH test and to verify the suitability of the micellar electrokinetic capillary chromatography (MEKC technique for analytical assessment and determination of three major poppy alkaloids (thebaine, morphine and papaverine. Because of its generally high separation efficiency, the MEKC is successfully used for analytical evaluation of biologically active substances usually without special claims for sample preparation. The results of DPPH test have shown that poppy contains components capable of terminating free radicals. We have confirmed that nature of the solvent used for the electrophoretic medium in MEKC has a strong influence on the separation efficiency. In our experiments, the most effective solvent was mixture of water to acetonitrile (ratio 4:6.

  18. A computational fluid dynamics analysis on stratified scavenging system of medium capacity two-stroke internal combustion engines

    Directory of Open Access Journals (Sweden)

    Pitta Srinivasa Rao

    2008-01-01

    Full Text Available The main objective of the present work is to make a computational study of stratified scavenging system in two-stroke medium capacity engines to reduce or to curb the emissions from the two-stroke engines. The 3-D flows within the cylinder are simulated using computational fluid dynamics and the code Fluent 6. Flow structures in the transfer ports and the exhaust port are predicted without the stratification and with the stratification, and are well predicted. The total pressure and velocity map from computation provided comprehensive information on the scavenging and stratification phenomenon. Analysis is carried out for the transfer ports flow and the extra port in the transfer port along with the exhaust port when the piston is moving from the top dead center to the bottom dead center, as the ports are closed, half open, three forth open, and full port opening. An unstructured cell is adopted for meshing the geometry created in CATIA software. Flow is simulated by solving governing equations namely conservation of mass momentum and energy using SIMPLE algorithm. Turbulence is modeled by high Reynolds number version k-e model. Experimental measurements are made for validating the numerical prediction. Good agreement is observed between predicted result and experimental data; that the stratification had significantly reduced the emissions and fuel economy is achieved.

  19. Chemical constituents, radical scavenging activity and enzyme inhibitory capacity of fruits from Cotoneaster pannosus Franch.

    Science.gov (United States)

    Les, Francisco; López, Víctor; Caprioli, Giovanni; Iannarelli, Romilde; Fiorini, Dennis; Innocenti, Marzia; Bellumori, Maria; Maggi, Filippo

    2017-05-24

    Cotoneaster pannosus (Rosaceae) is a semievergreen shrub, producing globose dark red pomes, native to China and widely used as an ornamental plant all over the world. Despite its extensive cultivation, little information is available on the chemical composition and biological activities of its fruits. In this work, the analysis of the chemical composition of C. pannosus fruits, in terms of phenolic components, carotenoids and ascorbic acid by HPLC/DAD, HPLC/ESI-MS and MS/MS as well as in terms of macro- and micro-nutrients was performed. The fruits proved to be a good source of shikimic acid and caffeoylquinic acids, whereas β-carotene, pelargonidin-3-O glucoside and cyanidin-3,5-rutinoside gave an important contribution to the color of the fruit. Both the polar and apolar fruit extracts showed noteworthy radical scavenger activity and inhibitory effects against monoamine oxidase A (MAO-A), tyrosinase (TYR) and α-glucosidase, making C. pannosus red pomes a promising candidate ingredient in functional foods and dietary supplements.

  20. In vitro antioxidant capacity and free radical scavenging evaluation of active metabolite constituents of Newbouldia laevis ethanolic leaf extract.

    Science.gov (United States)

    Habu, Josiah Bitrus; Ibeh, Bartholomew Okechukwu

    2015-03-14

    The aim of the present study was to evaluate the in vitro antioxidant and free radical scavenging capacity of bioactive metabolites present in Newbouldia laevis leaf extract. Chromatographic and spectrophotometric methods were used in the study and modified where necessary in the study. Bioactivity of the extract was determined at 10 μg/ml, 50 μg/ml, 100 μg/ml, 200 μg/ml and 400 μg/ml concentrations expressed in % inhibition. The yield of the ethanolic leaf extract of N.laevis was 30.3 g (9.93%). Evaluation of bioactive metabolic constituents gave high levels of ascorbic acid (515.53 ± 12 IU/100 g [25.7 mg/100 g]), vitamin E (26.46 ± 1.08 IU/100 g), saponins (6.2 ± 0.10), alkaloids (2.20 ± 0.03), cardiac glycosides(1.48 ± 0.22), amino acids and steroids (8.01 ± 0.04) measured in mg/100 g dry weight; moderate levels of vitamin A (188.28 ± 6.19 IU/100 g), tannins (0.09 ± 0.30), terpenoids (3.42 ± 0.67); low level of flavonoids (1.01 ± 0.34 mg/100 g) and absence of cyanogenic glycosides, carboxylic acids and aldehydes/ketones. The extracts percentage inhibition of DPPH, hydroxyl radical (OH.), superoxide anion (O2 .-), iron chelating, nitric oxide radical (NO), peroxynitrite (ONOO-), singlet oxygen (1O2), hypochlorous acid (HOCl), lipid peroxidation (LPO) and FRAP showed a concentration-dependent antioxidant activity with no significant difference with the controls. Though, IC50 of the extract showed significant difference only in singlet oxygen (1O2) and iron chelating activity when compared with the controls. The extract is a potential source of antioxidants/free radical scavengers having important metabolites which maybe linked to its ethno-medicinal use.

  1. Free-radical scavenging capacity and antioxidant properties of some selected onions (Allium cepa L. and garlic (Allium sativum L. extracts

    Directory of Open Access Journals (Sweden)

    Noureddine Benkeblia

    2005-09-01

    Full Text Available The radical scavenging activity (RAS, chain-breaking activity, H2O2-scavenging, reducing capacity and total phenolics of four types of onions (Green onion, Yellow, Red and Purple and garlic were investigated. Total phenolics varied from 30 mg (green onion to 49 mg.100 g-1 fresh weight (garlic. Garlic extract showed the highest RAS, while green onion showed the lowest one. The chain-breaking activity of green onion extract was higher (0.48 than garlic extract (0.029. Chain-breaking activity of yellow, red and purple onion extracts was 0.19, 0.048 and 0.032 respectively. However, heating treatment (90 ºC, 3h caused an increase in this activity. Low ability of green onion extract to scavenge hydrogen peroxide was noted (35%, whereas high ability was noted in other onion and garlic extracts and ranged from 60 to 90%. The lowest reducing capacity was noted in green onion extract (18%, whereas the highest in garlic extract (196%. Statistically, high significant correlations were observed between total phenolics content and reducing power, scavenging of hydrogen peroxide and chain-breaking activity of extract

  2. Homogenate-assisted Vacuum-powered Bubble Extraction of Moso Bamboo Flavonoids for On-line Scavenging Free Radical Capacity Analysis.

    Science.gov (United States)

    Sun, Yinnan; Yang, Kui; Cao, Qin; Sun, Jinde; Xia, Yu; Wang, Yinhang; Li, Wei; Ma, Chunhui; Liu, Shouxin

    2017-07-11

    A homogenate-assisted vacuum-powered bubble extraction (HVBE) method using ethanol was applied for extraction of flavonoids from Phyllostachys pubescens (P. pubescens) leaves. The mechanisms of homogenate-assisted extraction and vacuum-powered bubble generation were discussed in detail. Furthermore, a method for the rapid determination of flavonoids by HPLC was established. HVBE followed by HPLC was successfully applied for the extraction and quantification of four flavonoids in P. pubescens , including orientin, isoorientin, vitexin, and isovitexin. This method provides a fast and effective means for the preparation and determination of plant active components. Moreover, the on-line antioxidant capacity, including scavenging positive ion and negative ion free radical capacity of different fractions from the bamboo flavonoid extract was evaluated. Results showed that the scavenging DPPH ˙ free radical capacity of vitexin and isovitexin was larger than that of isoorientin and orientin. On the contrary, the scavenging ABTS⁺ ˙ free radical capacity of isoorientin and orientin was larger than that of vitexin and isovitexin.

  3. The scavenging of free radical and oxygen species activities and hydration capacity of collagen hydrolysates from walleye pollock ( Theragra chalcogramma) skin

    Science.gov (United States)

    Zhuang, Yongliang; Li, Bafang; Zhao, Xue

    2009-06-01

    Fish skin collagen hydrolysates (FSCH) were prepared from walleye pollock ( Theragra chalcogramma) using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3%. FSCH was mainly composed of low-molecular-weight peptides and the relative proportion of <1000Da fraction was 70.6%. Free radical and oxygen species scavenging activities of FSCH were investigated in four model systems, including diphenylpicrylhy-drazyl radical (DPPH), superoxide anion radical, hydroxyl radical and hydrogen peroxide model, and compared with that of a native antioxidant, reduced glutathione (GSH). FSCH was also evaluated by water-absorbing and water-holding capacity. The results showed that FSCH was able to scavenge free radical and oxygen species significantly and to enhance water-absorbing and water-holding capacity remarkably. Therefore, FSCH may have potential applications in the medicine and food industries.

  4. Antioxidant capacity and radical scavenging effect of polyphenol rich Mallotus philippenensis fruit extract on human erythrocytes: an in vitro study.

    Science.gov (United States)

    Gangwar, Mayank; Gautam, Manish Kumar; Sharma, Amit Kumar; Tripathi, Yamini B; Goel, R K; Nath, Gopal

    2014-01-01

    Mallotus philippinensis is an important source of molecules with strong antioxidant activity widely used medicinal plant. Previous studies have highlighted their anticestodal, antibacterial, wound healing activities, and so forth. So, present investigation was designed to evaluate the total antioxidant activity and radical scavenging effect of 50% ethanol fruit glandular hair extract (MPE) and its role on Human Erythrocytes. MPE was tested for phytochemical test followed by its HPLC analysis. Standard antioxidant assays like DPPH, ABTS, hydroxyl, superoxide radical, nitric oxide, and lipid peroxidation assay were determined along with total phenolic and flavonoids content. Results showed that MPE contains the presence of various phytochemicals, with high total phenolic and flavonoid content. HPLC analysis showed the presence of rottlerin, a polyphenolic compound in a very rich quantity. MPE exhibits significant strong scavenging activity on DPPH and ABTS assay. Reducing power showed dose dependent increase in concentration absorption compared to standard, Quercetin. Superoxide, hydroxyl radical, lipid peroxidation, nitric oxide assay showed a comparable scavenging activity compared to its standard. Our finding further provides evidence that Mallotus fruit extract is a potential natural source of antioxidants which have a protective role on human Erythrocytes exhibiting minimum hemolytic activity and this justified its uses in folklore medicines.

  5. Free radical scavenging capacity, anticandicidal effect of bioactive compounds from Sida cordifolia L., in combination with nystatin and clotrimazole and their effect on specific immune response in rats.

    Science.gov (United States)

    Ouédraogo, Maurice; Konaté, Kiessoun; Lepengué, Alexis Nicaise; Souza, Alain; M'Batchi, Bertrand; Sawadogo, Laya L

    2012-12-26

    Infectious diseases caused by fungi are still a major threat to public health, despite numerous efforts by researchers. Use of ethnopharmacological knowledge is one attractive way to reduce empiricism and enhance the probability of success in new drug-finding efforts. In this work, the total alkaloid compounds (AC) from Sida cordifolia L. (Malvaceae) have been investigated for their free radical scavenging capacity, antifungal and immunostimulatory properties. The antifungal activity was investigated against five candida strains using the microplate dilution method and the Fractional Inhibitory Concentration Index (FICI) of compounds was evaluated. The antioxidant activity of the samples was evaluate using three separate methods, at last, the immunostimulatory effect on immunosuppressed wistar rats was performed. As for the antifungal activity, result varied according to microorganism. The results obtained in this antifungal activity were interesting and indicated a synergistic effect between alkaloid compounds and the antifungal references such as Nystatin and Clotrimazole. Antioxidant capacity noticed that the reduction capacity of DPPH radicals obtained the best result comparatively to the others methods of free radical scavenging. Our results showed a low immunostimulatory effect and this result could be explained by the lack of biologically active antioxidants such as polyphenol compounds lowly contained in the alkaloid compounds. The results of this study showed that alkaloid compounds in combination with antifungal references (Nystatin and Clotrimazole) exhibited antimicrobial effects against candida strains tested. The results supported the utilization of these plants in infectious diseases particularly in treatment of candida infections.

  6. Free radical scavenging capacity, anticandicidal effect of bioactive compounds from Sida Cordifolia L., in combination with nystatin and clotrimazole and their effect on specific immune response in rats

    Directory of Open Access Journals (Sweden)

    Ouédraogo Maurice

    2012-12-01

    Full Text Available Abstract Background Infectious diseases caused by fungi are still a major threat to public health, despite numerous efforts by researchers. Use of ethnopharmacological knowledge is one attractive way to reduce empiricism and enhance the probability of success in new drug-finding efforts. In this work, the total alkaloid compounds (AC from Sida cordifolia L. (Malvaceae have been investigated for their free radical scavenging capacity, antifungal and immunostimulatory properties. Method The antifungal activity was investigated against five candida strains using the microplate dilution method and the Fractional Inhibitory Concentration Index (FICI of compounds was evaluated. The antioxidant activity of the samples was evaluate using three separate methods, at last, the immunostimulatory effect on immunosuppressed wistar rats was performed. Results As for the antifungal activity, result varied according to microorganism. The results obtained in this antifungal activity were interesting and indicated a synergistic effect between alkaloid compounds and the antifungal references such as Nystatin and Clotrimazole. Antioxidant capacity noticed that the reduction capacity of DPPH radicals obtained the best result comparatively to the others methods of free radical scavenging. Our results showed a low immunostimulatory effect and this result could be explained by the lack of biologically active antioxidants such as polyphenol compounds lowly contained in the alkaloid compounds. Conclusion The results of this study showed that alkaloid compounds in combination with antifungal references (Nystatin and Clotrimazole exhibited antimicrobial effects against candida strains tested. The results supported the utilization of these plants in infectious diseases particularly in treatment of candida infections.

  7. Analysis of passion fruit rinds (Passiflora edulis: isoorientin quantification by HPTLC and evaluation of antioxidant (radical scavenging capacity

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    Maria Luiza Zeraik

    2012-01-01

    Full Text Available The content of isoorientin in passion fruit rinds (Passiflora edulis fo. flavicarpa O. Degener was determined by HPTLC (high performance thin layer chromatography with densitometric analysis. The results revealed a higher amount of isoorientin in healthy rinds of P. edulis (92.275 ± 0.610 mg L-1 than in rinds with typical symptoms of PWV (Passion fruit Woodiness Virus infection (28.931 ± 0.346 mg L-1. The HPTLC data, allied to assays of radical scavenging activity, suggest the potential of P. edulis rinds as a natural source of flavonoids or as a possible functional food.

  8. Development of an in Silico Model of DPPH• Free Radical Scavenging Capacity: Prediction of Antioxidant Activity of Coumarin Type Compounds

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    Elizabeth Goya Jorge

    2016-06-01

    Full Text Available A quantitative structure-activity relationship (QSAR study of the 2,2-diphenyl-l-picrylhydrazyl (DPPH• radical scavenging ability of 1373 chemical compounds, using DRAGON molecular descriptors (MD and the neural network technique, a technique based on the multilayer multilayer perceptron (MLP, was developed. The built model demonstrated a satisfactory performance for the training ( R 2 = 0.713 and test set ( Q ext 2 = 0.654 , respectively. To gain greater insight on the relevance of the MD contained in the MLP model, sensitivity and principal component analyses were performed. Moreover, structural and mechanistic interpretation was carried out to comprehend the relationship of the variables in the model with the modeled property. The constructed MLP model was employed to predict the radical scavenging ability for a group of coumarin-type compounds. Finally, in order to validate the model’s predictions, an in vitro assay for one of the compounds (4-hydroxycoumarin was performed, showing a satisfactory proximity between the experimental and predicted pIC50 values.

  9. Effects of chlorogenic acid on capacity of free radicals scavenging and proteomic changes in postharvest fruit of nectarine.

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    Yu Xi

    Full Text Available To study how chlorogenic acid affects changes of reactive oxygen species (ROS and the proteins involved in ROS scavenging of nectarine during storage time, the fruits were treated with chlorogenic acid (CHA then stored at 25°C for further studies. The CHA-treatment significantly reduced O2-· production rate, H2O2 content, and membrane permeability of nectarine fruit during storage. The key proteins related the nectarine fruit senescence during storage were identified by two-dimensional electrophoresis and MALDI-TOF/TOF. Level and enzymatic activity of peroxidase were reduced, while both the protein levels and the enzymatic activities of superoxide dismutase, glutathione reductase, glutathione-s-transferase and monodehydroascorbate reductase were enhanced in nectarine fruit treated with CHA. In addition, levels of several pathogen-related proteins were also enhanced by CHA-treatment. Taking together, the present study showed that CHA could influence changes in defense related proteins and reduced oxidative damage in nectarine fruit during postharvest ripening.

  10. Bioactive Profiles, Antioxidant Activities, Nitrite Scavenging Capacities and Protective Effects on H2O2-Injured PC12 Cells of Glycyrrhiza Glabra L. Leaf and Root Extracts

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    Yi Dong

    2014-06-01

    Full Text Available This study compared the total flavonoid content of Glycyrrhiza glabra L. leaf and root extracts. Results suggested that the total flavonoid content in the leaf extract was obviously higher than that in the root extract. Pinocembrin, the main compound in the leaf extract after purification by column chromatography, showed good antioxidant activity and nitrite scavenging capacity, but moderate inhibitory effect on mushroom tyrosinase. Liquiritin was the main compound in root extract and possessed strong inhibitory effect on mushroom tyrosinase. Both compounds exhibited significant protection effect on H2O2-injured PC12 cells at a low concentration. These results indicate that Glycyrrhiza glabra L. leaf is potential as an important raw material for functional food.

  11. Effect of Solvent System on Extractability of Lipidic Components of Scenedesmus obliquus (M2-1) and Gloeothece sp. on Antioxidant Scavenging Capacity Thereof

    Science.gov (United States)

    Amaro, Helena M.; Fernandes, Fátima; Valentão, Patrícia; Andrade, Paula B.; Sousa-Pinto, I.; Malcata, F. Xavier; Guedes, A. Catarina

    2015-01-01

    Microalgae are well known for their biotechnological potential, namely with regard to bioactive lipidic components—especially carotenoids and polyunsaturated fatty acids (PUFA), well-known for therapeutic applications based on their antioxidant capacity. The aim of this work was to evaluate the influence of four distinct food-grade solvents upon extractability of specific lipidic components, and on the antioxidant capacity exhibited against both synthetic (2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS+•)) and biological reactive species (O2•− and •NO−). A eukaryotic microalga (Scenedesmus obliquus (M2-1)) and a prokaryotic one (Gloeothece sp.) were used as case studies. Concerning total antioxidant capacity, the hexane:isopropanol (3:2) and acetone extracts of Sc. obliquus (M2-1) were the most effective against DPPH• and ABTS+•, respectively. Gloeothece sp. ethanol extracts were the most interesting scavengers of O2•−, probably due the high content of linolenic acid. On the other hand, acetone and hexane:isopropanol (3:2) extracts were the most interesting ones in •NO− assay. Acetone extract exhibited the best results for the ABTS assay, likely associated to its content of carotenoids, in both microalgae. Otherwise, ethanol stood out in PUFA extraction. Therefore, profiles of lipidic components extracted are critical for evaluating the antioxidant performance—which appears to hinge, in particular, on the balance between carotenoids and PUFAs. PMID:26492257

  12. Effect of Solvent System on Extractability of Lipidic Components of Scenedesmus obliquus (M2-1 and Gloeothece sp. on Antioxidant Scavenging Capacity Thereof

    Directory of Open Access Journals (Sweden)

    Helena M. Amaro

    2015-10-01

    Full Text Available Microalgae are well known for their biotechnological potential, namely with regard to bioactive lipidic components—especially carotenoids and polyunsaturated fatty acids (PUFA, well-known for therapeutic applications based on their antioxidant capacity. The aim of this work was to evaluate the influence of four distinct food-grade solvents upon extractability of specific lipidic components, and on the antioxidant capacity exhibited against both synthetic (2,2-diphenyl-1-picrylhydrazyl (DPPH• and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS+• and biological reactive species (O2•- and •NO-. A eukaryotic microalga (Scenedesmus obliquus (M2-1 and a prokaryotic one (Gloeothece sp. were used as case studies. Concerning total antioxidant capacity, the hexane:isopropanol (3:2 and acetone extracts of Sc. obliquus (M2-1 were the most effective against DPPH• and ABTS+•, respectively. Gloeothece sp. ethanol extracts were the most interesting scavengers of O2•-, probably due the high content of linolenic acid. On the other hand, acetone and hexane:isopropanol (3:2 extracts were the most interesting ones in •NO- assay. Acetone extract exhibited the best results for the ABTS assay, likely associated to its content of carotenoids, in both microalgae. Otherwise, ethanol stood out in PUFA extraction. Therefore, profiles of lipidic components extracted are critical for evaluating the antioxidant performance—which appears to hinge, in particular, on the balance between carotenoids and PUFAs.

  13. Some biological compounds, radical scavenging capacities and antimicrobial activities in the seeds of Nepeta italica L. and Sideritis montana L. sub sp. montana from Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Emre, I.; Kursat, M.; Yilmaz, O.; Erecevit, P.

    2011-07-01

    This study determined some biological compounds (fatty acid compositions, lipid-soluble vitamins, sterols, flavonoids), radical scavenging capacities and antimicrobial activities in the seeds of Nepeta italica L. and Sideritis montana L. subsp. montana. It was found that palmitic acid (C16:0; 8.54+-0.13-3.05+-0.04%), oleic acid (C18:1 n9, 22.41+-0.8-18.83+-0.1%) and a-inolenic acid were the dominant fatty acids in both Nepeta italica L. and Sideritis montana L. subsp. montana. It was concluded that both Nepeta italica L. and Sideritis montana L. subsp. montana contained stigmasterol and ergosterol as well as beta-sitosterol. The present findings show that Nepeta italica L. contains morin, catechin, naringin and Sideritis montana L. subsp. montana contains morin, naringenin as major flavonoids. It was also determined that methanol extracts of Nepeta italica L. and Sideritis montana L. subsp. montana were most effective against DPPH radicals. The results of the present study show that the vitamins, flavonoids and fatty acid extracts in the seeds of N. italica L. and S. montana L. subsp. montana prevented the growth of the microorganisms used in the tests at different ratios. (Author).

  14. A multiple free-radical scavenging (MULTIS) study on the antioxidant capacity of a neuroprotective drug, edaravone as compared with uric acid, glutathione, and trolox.

    Science.gov (United States)

    Kamogawa, Erisa; Sueishi, Yoshimi

    2014-03-01

    Edaravone (3-methyl-1-phenyl-2-pyrazoline-5-one) is a neuroprotective drug that has been used for brain ischemia injury treatment. Because its activity is speculated to be due to free radical scavenging activity, we carried out a quantitative determination of edaravone's free radical scavenging activity against multiple free radical species. Electron spin resonance (ESR) spin trapping-based multiple free-radical scavenging (MULTIS) method was employed, where target free radicals were hydroxyl radical, superoxide anion, alkoxyl radical, alkylperoxyl radical, methyl radical, and singlet oxygen. Edaravone showed relatively high scavenging abilities against hydroxyl radical (scavenging rate constant k=2.98×10(11) M(-1) s(-1)), singlet oxygen (k=2.75×10(7) M(-1) s(-1)), and methyl radical (k=3.00×10(7) M(-1) s(-1)). Overall, edaravone's scavenging activity against multiple free radical species is as robust as other known potent antioxidant such as uric acid, glutathione, and trolox. A radar chart illustration of the MULTIS activity relative to uric acid, glutathione, and trolox indicates that edaravone has a high and balanced antioxidant activity with low specificity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Screening of Six Medicinal Plant Extracts Obtained by Two Conventional Methods and Supercritical CO₂ Extraction Targeted on Coumarin Content, 2,2-Diphenyl-1-picrylhydrazyl Radical Scavenging Capacity and Total Phenols Content.

    Science.gov (United States)

    Molnar, Maja; Jerković, Igor; Suknović, Dragica; Bilić Rajs, Blanka; Aladić, Krunoslav; Šubarić, Drago; Jokić, Stela

    2017-02-24

    Six medicinal plants Helichrysum italicum (Roth) G. Don, Angelica archangelica L., Lavandula officinalis L., Salvia officinalis L., Melilotus officinalis L., and Ruta graveolens L. were used. The aim of the study was to compare their extracts obtained by Soxhlet (hexane) extraction, maceration with ethanol (EtOH), and supercritical CO₂ extraction (SC-CO₂) targeted on coumarin content (by high performance liquid chromatography with ultraviolet detection, HPLC-UV), 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging capacity, and total phenols (TPs) content (by Folin-Ciocalteu assay). The highest extraction yields were obtained by EtOH, followed by hexane and SC-CO₂. The highest coumarin content (316.37 mg/100 g) was found in M. officinalis EtOH extracts, but its SC-CO₂ extraction yield was very low for further investigation. Coumarin was also found in SC-CO₂ extracts of S. officinalis , R. graveolens , A. archangelica , and L. officinalis . EtOH extracts of all plants exhibited the highest DPPH scavenging capacity. SC-CO₂ extracts exhibited antiradical capacity similar to hexane extracts, while S. officinalis SC-CO₂ extracts were the most potent (95.7%). EtOH extracts contained the most TPs (up to 132.1 mg gallic acid equivalents (GAE)/g from H. italicum ) in comparison to hexane or SC-CO₂ extracts. TPs content was highly correlated to the DPPH scavenging capacity of the extracts. The results indicate that for comprehensive screening of different medicinal plants, various extraction techniques should be used in order to get a better insight into their components content or antiradical capacity.

  16. Screening of Six Medicinal Plant Extracts Obtained by Two Conventional Methods and Supercritical CO2 Extraction Targeted on Coumarin Content, 2,2-Diphenyl-1-picrylhydrazyl Radical Scavenging Capacity and Total Phenols Content

    Directory of Open Access Journals (Sweden)

    Maja Molnar

    2017-02-01

    Full Text Available Six medicinal plants Helichrysum italicum (Roth G. Don, Angelica archangelica L., Lavandula officinalis L., Salvia officinalis L., Melilotus officinalis L., and Ruta graveolens L. were used. The aim of the study was to compare their extracts obtained by Soxhlet (hexane extraction, maceration with ethanol (EtOH, and supercritical CO2 extraction (SC-CO2 targeted on coumarin content (by high performance liquid chromatography with ultraviolet detection, HPLC-UV, 2,2-diphenyl-1-picrylhydrazyl radical (DPPH scavenging capacity, and total phenols (TPs content (by Folin–Ciocalteu assay. The highest extraction yields were obtained by EtOH, followed by hexane and SC-CO2. The highest coumarin content (316.37 mg/100 g was found in M. officinalis EtOH extracts, but its SC-CO2 extraction yield was very low for further investigation. Coumarin was also found in SC-CO2 extracts of S. officinalis, R. graveolens, A. archangelica, and L. officinalis. EtOH extracts of all plants exhibited the highest DPPH scavenging capacity. SC-CO2 extracts exhibited antiradical capacity similar to hexane extracts, while S. officinalis SC-CO2 extracts were the most potent (95.7%. EtOH extracts contained the most TPs (up to 132.1 mg gallic acid equivalents (GAE/g from H. italicum in comparison to hexane or SC-CO2 extracts. TPs content was highly correlated to the DPPH scavenging capacity of the extracts. The results indicate that for comprehensive screening of different medicinal plants, various extraction techniques should be used in order to get a better insight into their components content or antiradical capacity.

  17. Some Biological Compounds, Radical Scavenging Capacities and Antimicrobial Activities in the seeds of Nepeta italica L. and Sideritis montana L. subsp. montana from Turkey

    Directory of Open Access Journals (Sweden)

    Erecevit, Pınar

    2011-03-01

    Full Text Available This study determined some biological compounds (fatty acid compositions, lipid-soluble vitamins, sterols, flavonoids, radical scavenging capacities and antimicrobial activities in the seeds of Nepeta italica L. and Sideritis montana L. subsp. montana. It was found that palmitic acid (C16:0; 8.54±0.13- 3.05±0.04%, oleic acid (C18:1 n9, 22.41±0.8-18.83±0.1% and α-linolenic acid (C18:3 n3;39.56±0.67-77.04±2.07% were the dominant fatty acids in both Nepeta italica L. and Sideritis montana L. subsp. montana. It was concluded that both Nepeta italica L. and Sideritis montana L. subsp. montana contained stigmasterol (630.07±1.81µg/g, 80.74±0.71µg/g, respectively and ergosterol (1.11±0.14µg/g, 161.32±0.63µg/g respectively as well as beta-sitosterol (2.93±0.03 µg/g. The present findings show that Nepeta italica L. contains morin (37.79±1.09μg/g, catechin (124.39±2.23µg/g, naringin (475.96±3.57µg/g and Sideritis montana L. subsp. montana contains morin (188.41±2.53µg/g, catechin (64.14±1.86μg/g, naringenin (38.34±1.78μg/g as major flavonoids. It was also determined that methanol extracts of Nepeta italica L. and Sideritis montana L. subsp. montana were most effective against DPPH radicals. The results of the present study show that the vitamins, flavonoids and fatty acid extracts in the seeds of N. italica L. and S. montana L. subsp. montana prevented the growth of the microorganisms used in the tests at different ratios.Este estudio ha determinado algunos compuestos biológicos (ácidos grasos, vitaminas liposolubles, esteroles y flavonoides, capacidad atrapadora de radicales libres, y actividades antimicrobianas de las semillas de Nepeta italica L. y Sideritis montana L. subsp. montana. Se encontró que el ácido palmítico (C16:0; 8.54±0.13-3.05±0.04%, ácido oleico (C18:1 n9, 22.41±0.8-18.83±0.1% y α-linolénico (C18:3 n 3;39.56±0.67-77.04±2.07% eran mayoritarios en ambas semillas de Nepeta italica L. y Sideritis

  18. Peroxynitrite scavenging by flavonids.

    NARCIS (Netherlands)

    Haenen, G.R.M.M.; Paquay, J.B.G.; Korthouwer, R.E.M.; Bast, A.

    1997-01-01

    The peroxynitrite scavenging activity of a series of structurally related flavonoids was tested. It was found that flavonoids are excellent scavengers of peroxynitrite. Compared to the known peroxynitrite scavenger ebselen, the most active flavonoids proved to be 10 times more effective. Indications

  19. Free radical scavenging capacity and antioxidant activity of methanolic and ethanolic extracts of plum (Prunus domestica L. in both fresh and dried samples

    Directory of Open Access Journals (Sweden)

    Amin Morabbi Najafabad

    2014-09-01

    Full Text Available Objectives: Consumption of fruits, such as plums and prunes, is useful in treating blood circulation disorder, measles, digestive disorder, and prevention of cancer, diabetes, and obesity. The paper presents a description of antioxidant and antiradical capacity of plum (Prunus domestica L. in both fresh and dried samples. Materials and Methods: Samples were mixed with methanol and ethanol (as solvents and were extracted on magnetic shaker, separately. The experiments were carried out to measure the Total Phenolic Content (TPC, Total Flavonoid Content (TFC, Total Antioxidant Capacity (TAC, Reducing Power Assay (RPA, Chain Breaking Activity (CBA, and quantity of Malondialdehyde (MDA, 2,2-Diphenyl-1-Picrylhydrazyl (DPPH,Nitric Oxide (NO,Hydrogen peroxide (H2O2 and superoxide(O2- radicals inhibition. Results: The results showed that the highest values for the TPC, TFC,TAC, RPA, CBA, DPPH, and NO were related to ethanolic extractsof dried sample which showed statistically significant differences (p2O2 and O2-were related to ethanolic extracts of fresh sample. The correlations data were analyzed among all parameters and the TPC and TFC had a significant correlation (r2=0.977. Moreover, it was found that methanol was more successful in extraction procedure than ethanol (p

  20. Botanical Scavenger Hunt

    Science.gov (United States)

    Walker-Livingston, Wendy

    2009-01-01

    Why not combine the use of technology with the excitement of a scavenger hunt that moves middle-level students out into the "wilds" of their school campus to classify plants? In the lesson plan described here, students embark on a botanical scavenger hunt and then document their findings using a digital camera. This project was designed to allow…

  1. Free Radicals Scavenging Capacity, Antidiabetic and Antihypertensive Activities of Flavonoid-Rich Fractions from Leaves of Trichilia emetica and Opilia amentacea in an Animal Model of Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Kiessoun Konaté

    2014-01-01

    Full Text Available Trichilia emetica and Opilia amentacea traditional Burkinabe medicinal plants were investigated to determine their therapeutic potential to inhibit key enzymes in carbohydrate metabolism, which has relevance to the management of type 2 diabetes. In vitro and in vivo antioxidant and antihypertensive potential and antilipidemia and antihyperglycemia activities in an animal model of type 2 diabetes mellitus have been studied. The antioxidant activity of the flavonoids from leaves of Trichilia emetica and Opilia amentacea has been evaluated using β-carotene-linoleic acid system, 1,1-diphenyl-2-picrylhydrazyl inhibitory activity, chelation of iron (II ions, and lipid peroxidation which showed more pronounced antioxidant capacities of Trichilia emetica. Total cholesterol concentrations decreased in an animal model of type 2 diabetes mellitus under effects of flavonoid-rich fractions from leaves of Trichilia emetica and Opilia amentacea has been observed. Extract of flavonoid-rich fractions from Trichilia emetica shown maximum radical scavenging activity and possessed marked antiamylase activity which may be due to the presence of certain secondary metabolites. Suggested better antihyperglycemia, antilipidemia, and antihypertensive properties of flavonoid-rich fractions from Trichilia emetica compared to the extract of Opilia amentacea are demonstrating antidiabetic potential of Trichilia emetica as therapeutic targets for the management of type 2 diabetes.

  2. Hemoglobin and heme scavenger receptors

    DEFF Research Database (Denmark)

    Nielsen, Marianne Jensby; Møller, Holger Jon; Moestrup, Søren Kragh

    2010-01-01

    Heme, the functional group of hemoglobin, myoglobin, and other hemoproteins, is a highly toxic substance when it appears in the extracellular milieu. To circumvent potential harmful effects of heme from hemoproteins released during physiological or pathological cell damage (such as hemolysis...... and rhabdomyolysis), specific high capacity scavenging systems have evolved in the mammalian organism. Two major systems, which essentially function in a similar way by means of a circulating latent plasma carrier protein that upon ligand binding is recognized by a receptor, are represented by a) the hemoglobin...

  3. A Geospatial Scavenger Hunt

    Science.gov (United States)

    Martinez, Adriana E.; Williams, Nikki A.; Metoyer, Sandra K.; Morris, Jennifer N.; Berhane, Stephen A.

    2009-01-01

    With the use of technology such as Global Positioning System (GPS) units and Google Earth for a simple-machine scavenger hunt, you will transform a standard identification activity into an exciting learning experience that motivates students, incorporates practical skills in technology, and enhances students' spatial-thinking skills. In the…

  4. Free Radical Scavenging Properties of Annona squamosa

    Science.gov (United States)

    Vikas, Biba; Akhil B, S; P, Remani; Sujathan, K

    2017-10-26

    Annona squamosa has extensively been used in the traditional and folkloric medicine and found to possess many biological activities. Different solvents, petroleum ether, chloroform, ethyl acetate and methanol extracts of Annona squamosa seeds (ASPE, ASCH, ASEA, ASME) have been used to prepare plant extracts. The present investigations dealt with the free radical scavenging activity of four extracts using various techniques such as total reducing power estimation, total phenolic count, 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging effect, evaluation of ABTS cation decolorisation capacity, FRAP assay, hdroxyl radical scavenging assay, super oxide assay and Nitric oxide radical scavenging assay of the extracts. The results showed that the four extracts of Annona squamosa showed significant reducing power in four extracts. The total phenolic contents in petroleum ether, chloroform, ethyl acetate, methanol extracts and positive control were 0.64±0.17, 0.54±0.27, 0.49±0.24, 0.57±0.22 and 0.66±0.33. The antioxidant capacity by ABTS assay of ASPE, ASCH, ASEA, ASME and positive control, trolox showed 77.75±0.5,73.25±1.7,78.5± 1.2 , 80 ± 0.8 μg/ml and 94.2 ± 0.9 respectively. The (50 % scavenging activity) SA50 of ASPE and ASCH, ASEA and ASME was found to be 34.4 μg/ml, 43.8 μg/ml 34.7 μg/m and 28.8 μg/ml respectively by DPPH assay. The percentage of hydroxyl radical scavenging increased with the increasing concentration of the extracts. ASPE, ASCH, ASEA and ASME showed superoxide radical scavenging activity, as indicated by their values 66 ± 0.5, 68 ± 1 ,63 ± 1 and 70 ± 0.5 μg/ml respectively compared to gallic acid which was 97 ± 0.5 μg/ml. The values for scavenging of nitric oxide for ASPE, ASCH, ASEA and ASME were 91.0 ± 1.0, 66.75 ± 0.5, 71.75 ± 1.1 and 75.75 ± 1.15 μg/ml while value for standard ascorbic acid was 91.0 ± 1.0 μg/ml. The results revealed strong antioxidants in four extracts may lead to the development of potent

  5. Acclimation to Chronic O3 in Field-grown Soybean is Characterized by Increased Levels of TCA Cycle Transcripts and ROS Scavenging Compounds in Addition to Decreased Photosynthetic Capacity

    Science.gov (United States)

    Tropospheric ozone (O3) is a pollutant that is generated by volatile organic compounds, nitrogen oxides and sunlight. When plants take in O3 through stomata, harmful reactive oxygen species (ROS) are produced that induce the production of ROS scavenging antioxidants. Climate change predictions indic...

  6. Correlation, by multivariate statistical analysis, between the scavenging capacity against reactive oxygen species and the bioactive compounds from frozen fruit pulps Correlação, por análise estatística multivariada, entre desativação de espécies reativas de oxigênio e compostos bioativos de polpas de frutas congeladas

    Directory of Open Access Journals (Sweden)

    Lizziane Cynara Vissotto

    2013-02-01

    Full Text Available The contents of total phenolic compounds (TPC, total flavonoids (TF, and ascorbic acid (AA of 18 frozen fruit pulps and their scavenging capacities against peroxyl radical (ROO•, hydrogen peroxide (H2O2, and hydroxyl radical (•OH were determined. Principal Component Analysis (PCA showed that TPC (total phenolic compounds and AA (ascorbic acid presented positive correlation with the scavenging capacity against ROO•, and TF (total flavonoids showed positive correlation with the scavenging capacity against •OH and ROO• However, the scavenging capacity against H2O2 presented low correlation with TF (total flavonoids, TPC (total phenolic compounds, and AA (ascorbic acid. The Hierarchical Cluster Analysis (HCA allowed the classification of the fruit pulps into three groups: one group was formed by the açai pulp with high TF, total flavonoids, content (134.02 mg CE/100 g pulp and the highest scavenging capacity against ROO•, •OH and H2O2; the second group was formed by the acerola pulp with high TPC, total phenolic compounds, (658.40 mg GAE/100 g pulp and AA , ascorbic acid, (506.27 mg/100 g pulp contents; and the third group was formed by pineapple, cacao, caja, cashew-apple, coconut, cupuaçu, guava, orange, lemon, mango, passion fruit, watermelon, pitanga, tamarind, tangerine, and umbu pulps, which could not be separated considering only the contents of bioactive compounds and the scavenging properties.Os teores de compostos fenólicos totais (CFT, flavonoides totais (FT e ácido ascórbico (AA foram determinados em 18 polpas de frutas congeladas, assim como a capacidade antioxidante na desativação do radical peroxila (ROO•, peróxido de hidrogênio (H2O2 e radical hidroxila (•OH. De acordo com a Análise de Componentes Principais (ACP, CFT e AA apresentaram correlação positiva com a capacidade de desativar o ROO• e o teor de FT apresentou correlação positiva com a capacidade de desativar o •OH e ROO•. Entretanto, a

  7. Organobasierter Sauerstoff-Scavenger/-Indikator

    OpenAIRE

    Langowski, H.C.; Wanner, T.

    2007-01-01

    WO 2007059901 A1 UPAB: 20070911 NOVELTY - Oxygen scavenger/indicator which contains at least one substance having combined scavenging and indicating functions for oxygen which is capable of absorbing oxygen under the effect of moisture in alkaline conditions, and at least one alkaline compound. The indicator effect is caused by a change in at least one physical property of the substance having combined scavenging and indicating function for oxygen, the change being initiated by the presence o...

  8. In vitro free radical scavenging activity of Ixora coccinea L

    Directory of Open Access Journals (Sweden)

    Moni Rani Saha

    2008-06-01

    Full Text Available Antioxidant activity of the methanol extract of Ixora coccinea L. was determined by DPPH free radical scavenging assay, reducing power and total antioxidant capacity using phosphomolybdenum method. Preliminary phytochemical screening revealed that the extract of the flower of I. coccinea possesses flavonoids, steroids and tannin materials. The extract showed significant activities in all antioxidant assays compared to the standard antioxidant in a dose dependent manner and remarkable activities to scavenge reactive oxygen species (ROS may be attributed to the high amount of hydrophilic phenolics. In DPPH radical scavenging assay the IC50 value of the extract was found to be 100.53 μg/mL while ascorbic acid had the IC50 value 58.92 μg/mL. Moreover, I. coccinea extract showed strong reducing power and total antioxidant capacity.

  9. Rain scavenging of radioactive particles

    International Nuclear Information System (INIS)

    Williams, A.L.

    1975-01-01

    An assessment is made of the rainout of airborne radioactive particles from a nuclear detonation with emphasis on the microphysical removal processes. For submicron particles the scavenging processes examined are Brownian and turbulent diffusion to cloud droplets. For particles larger than 1 μm radius, nucleation scavenging is examined. For various particle size and radioactivity distributions, it is found that from 27 to 99 percent of the radioactivity is attached to cloud droplets and subject to rapid removal by rain. (U.S.)

  10. Precipitation scavenging of aerosol particles

    International Nuclear Information System (INIS)

    Radke, L.F.; Eltgroth, M.W.; Hobbs, P.V.

    1978-01-01

    The paper presents the results of precipitation scavenging measurements of particles in the atmosphere and in plumes which were obtained using an airborne measuring system. Attention is given to the so-called 'Greenfield gap' and collection efficiencies for submicron particles

  11. Interactive effects of silicon and arbuscular mycorrhiza in modulating ascorbate-glutathione cycle and antioxidant scavenging capacity in differentially salt-tolerant Cicer arietinum L. genotypes subjected to long-term salinity.

    Science.gov (United States)

    Garg, Neera; Bhandari, Purnima

    2016-09-01

    Salinity is the major environmental constraint that affects legume productivity by inducing oxidative stress. Individually, both silicon (Si) nutrition and mycorrhization have been reported to alleviate salt stress. However, the mechanisms adopted by both in mediating stress responses are poorly understood. Thus, pot trials were undertaken to evaluate comparative as well as interactive effects of Si and/or arbuscular mycorrhiza (AM) in alleviating NaCl toxicity in modulating oxidative stress and antioxidant defence mechanisms in two Cicer arietinum L. (chickpea) genotypes-HC 3 (salt-tolerant) and CSG 9505 (salt-sensitive). Plants subjected to different NaCl concentrations (0-100 mM) recorded a substantial increase in the rate of superoxide radical (O2 (·-)), H2O2, lipoxygenase (LOX) activity and malondialdehyde (MDA) content, which induced leakage of ions and disturbed Ca(2+)/Na(+) ratio in roots and leaves. Individually, Si and AM reduced oxidative burst by strengthening antioxidant enzymatic activities (superoxide dismutase (SOD), catalase (CAT) and guaiacol peroxidase (GPOX)). Si was relatively more efficient in reducing accumulation of stress metabolites, while mycorrhization significantly up-regulated antioxidant machinery and modulated ascorbate-glutathione (ASA-GSH) cycle. Combined applications of Si and AM complemented each other in reducing reactive oxygen species (ROS) build-up by further enhancing the antioxidant defence responses. Magnitude of ROS-mediated oxidative burden was lower in HC 3 which correlated strongly with more effective AM symbiosis, better capacity to accumulate Si and stronger defence response when compared with CSG 9505. Study indicated that Si and/or AM fungal amendments upgraded salt tolerance through a dynamic shift from oxidative destruction towards favourable antioxidant defence system in stressed chickpea plants.

  12. Magnetic graphene based nanocomposite for uranium scavenging

    Energy Technology Data Exchange (ETDEWEB)

    El-Maghrabi, Heba H. [Egyptian Petroleum Research Institute, 11727, Cairo (Egypt); Abdelmaged, Shaimaa M. [Nuclear Materials Authority, 6530 P.O. Box Maadi, Cairo (Egypt); Nada, Amr A. [Egyptian Petroleum Research Institute, 11727, Cairo (Egypt); Zahran, Fouad, E-mail: f.zahran@quim.ucm.es [Faculty of Science, Helwan University, 11795, Cairo (Egypt); El-Wahab, Saad Abd; Yahea, Dena [Faculty of Science, Ain shams University, Cairo (Egypt); Hussein, G.M.; Atrees, M.S. [Nuclear Materials Authority, 6530 P.O. Box Maadi, Cairo (Egypt)

    2017-01-15

    Graphical abstract: Graphical representation of U{sup 6+} adsorption on Magnetic Ferberite-Graphene Nanocomposite. - Highlights: • Synthesis of new magnetic wolframite bimetallic nanostructure on graphene. • A promising adsorption capacity of 455 mg/g was recorded for FG-20 within 60 min at room temperature. • The uranium removal was followed pseudo-second order kinetics and Langmuir isotherm. - Abstract: Magnetic graphene based ferberite nanocomposite was tailored by simple, green, low cost and industrial effective method. The microstructure and morphology of the designed nanomaterials were examined via XRD, Raman, FTIR, TEM, EDX and VSM. The prepared nanocomposites were introduced as a novel adsorbent for uranium ions scavenging from aqueous solution. Different operating conditions of time, pH, initial uranium concentration, adsorbent amount and temperature were investigated. The experimental data shows a promising adsorption capacity. In particular, a maximum value of 455 mg/g was obtained within 60 min at room temperature with adsorption efficiency of 90.5%. The kinetics and isotherms adsorption data were fitted with the pseudo-second order model and Langmuir equation, respectively. Finally, the designed nanocomposites were found to have a great degree of sustainability (above 5 times of profiteering) with a complete maintenance of their parental morphology and adsorption capacity.

  13. 21 CFR 868.5590 - Scavenging mask.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Scavenging mask. 868.5590 Section 868.5590 Food... DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5590 Scavenging mask. (a) Identification. A scavenging mask is a device positioned over a patient's nose to deliver anesthetic or analgesic gases to the...

  14. Scavenging in the genus Natrix

    Directory of Open Access Journals (Sweden)

    Cesar Ayres

    2012-07-01

    Full Text Available Scavenging is reported as an unusual behaviour of snakes. However, it is likely more common than is supposed. Here I report the use of dead newts as prey source by water snakes of the genus Natrix at a dam in north-western Spain. Juveniles and adults viperine snakes (Natrix maura, and also an adult grass snake (Natrix natrix were found feeding on newt carcasses.

  15. The Impact of Flight Hardware Scavenging on Space Logistics

    Science.gov (United States)

    Oeftering, Richard C.

    2011-01-01

    For a given fixed launch vehicle capacity the logistics payload delivered to the moon may be only roughly 20 percent of the payload delivered to the International Space Station (ISS). This is compounded by the much lower flight frequency to the moon and thus low availability of spares for maintenance. This implies that lunar hardware is much more scarce and more costly per kilogram than ISS and thus there is much more incentive to preserve hardware. The Constellation Lunar Surface System (LSS) program is considering ways of utilizing hardware scavenged from vehicles including the Altair lunar lander. In general, the hardware will have only had a matter of hours of operation yet there may be years of operational life remaining. By scavenging this hardware the program, in effect, is treating vehicle hardware as part of the payload. Flight hardware may provide logistics spares for system maintenance and reduce the overall logistics footprint. This hardware has a wide array of potential applications including expanding the power infrastructure, and exploiting in-situ resources. Scavenging can also be seen as a way of recovering the value of, literally, billions of dollars worth of hardware that would normally be discarded. Scavenging flight hardware adds operational complexity and steps must be taken to augment the crew s capability with robotics, capabilities embedded in flight hardware itself, and external processes. New embedded technologies are needed to make hardware more serviceable and scavengable. Process technologies are needed to extract hardware, evaluate hardware, reconfigure or repair hardware, and reintegrate it into new applications. This paper also illustrates how scavenging can be used to drive down the cost of the overall program by exploiting the intrinsic value of otherwise discarded flight hardware.

  16. To scavenge or not to scavenge: that is the question

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, Elzbieta; Brzuszkiewicz, Anna [Synchrotron Radiation Research Section, MCL, National Cancer Institute, Argonne National Laboratory, Argonne, IL 60439 (United States); Dauter, Miroslawa [SAIC-Frederick Inc., Basic Research Program, Argonne National Laboratory, Argonne, IL 60439 (United States); Dauter, Zbigniew, E-mail: dauter@anl.gov [Synchrotron Radiation Research Section, MCL, National Cancer Institute, Argonne National Laboratory, Argonne, IL 60439 (United States); Rosenbaum, Gerd, E-mail: dauter@anl.gov [Department of Biochemistry, University of Georgia, SER-CAT at the APS, Argonne, IL 60439 (United States); Synchrotron Radiation Research Section, MCL, National Cancer Institute, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2009-09-01

    Analysis of a series of diffraction data sets measured from several native as well as nicotinic acid-soaked crystals of trypsin suggests that this potential scavenger does not have any statistically significant effect on the amount of radiation damage incurred in the crystals on X-ray irradiation at 100 K. Analysis of a series of diffraction data sets measured from four native as well as four nicotinic acid-soaked crystals of trypsin at 100 K shows a high variability in radiation-sensitivity among individual crystals for both nicotinic acid-soaked and native crystals. The level of radiation-sensitivity and the extent of its variability is statistically indistinguishable between the two conditions. This suggests that this potential scavenger does not have any statistically significant effect on the amount of radiation damage incurred in the crystals on X-ray irradiation. This is in contrast to previous results [Kauffmann et al. (2006 ▶), Structure, 14, 1099–1105] where only one crystal specimen was used for each condition (native and nicotinic acid-soaked)

  17. In vitro evaluation of peroxyl radical scavenging capacity of water ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-04-06

    Apr 6, 2009 ... ... phenolics viz. condensed tannin and phlobatannin, gallic acid, protocatechuic acid pyrocatechol, (+)- ... Lipid peroxidation by thiobarbituric acid assay (TBA). TBA reacts with .... Antifungal activity of polyphenolic complex of ...

  18. Oxygen radical-scavenging capacities of peptides from swine blood

    African Journals Online (AJOL)

    USER

    2010-08-02

    Aug 2, 2010 ... ... a basic factor in maintaining life and health (Stadtman and Levine, 2003). ... these problems, peptides from swine blood (PSB) was obtained by the ... (0.05 µm ceramic membrane), ultra-filtration (1000 Da), and spray-drying.

  19. Free-radical scavenging capacity and antimicrobial activity of wild ...

    African Journals Online (AJOL)

    ... Escherichia coli, Morganella morganii and Proteus vulgaris. The antimicrobial activity profile of R. flava against tested strains indicated that Micrococcus flavus, Micrococcus luteus and Yersinia enterocolitica was the most susceptible bacteria of all the test strains. R. flava was found to be inactive against Candida albicans.

  20. Scavenging and recombination kinetics in radiation chemistry.

    Science.gov (United States)

    Al-Samra, Eyad H; Green, Nicholas J B

    2017-08-02

    This work describes stochastic models developed to study the competition between radical scavenging and recombination for simple model systems typical of radiation chemistry, where the reactive particles are tightly clustered and reactions are assumed fully diffusion limited. Three models are developed: a Monte Carlo random flights model with a periodic boundary condition for scavengers, Monte Carlo simulations in which the scavenging rate is calculated from the Smoluchowski theory for diffusion-limited reactions and a modification of the independent reaction times method where the scavengers close to the spur are explicitly included and the scavengers further away are treated as a continuum. The results indicate that the Smoluchowski theory makes a systematic overestimate of the scavenging rate when such competition is present. A correction for the Smoluchowski rate constant is suggested, an analytical justification is presented and it is tested against the simulations, and shown to be a substantial improvement.

  1. Energy scavenging from environmental vibration.

    Energy Technology Data Exchange (ETDEWEB)

    Galchev, Tzeno (University of Michigan); Apblett, Christopher Alan; Najafi, Khalil (University of Michigan)

    2009-10-01

    The goal of this project is to develop an efficient energy scavenger for converting ambient low-frequency vibrations into electrical power. In order to achieve this a novel inertial micro power generator architecture has been developed that utilizes the bi-stable motion of a mechanical mass to convert a broad range of low-frequency (< 30Hz), and large-deflection (>250 {micro}m) ambient vibrations into high-frequency electrical output energy. The generator incorporates a bi-stable mechanical structure to initiate high-frequency mechanical oscillations in an electromagnetic scavenger. This frequency up-conversion technique enhances the electromechanical coupling and increases the generated power. This architecture is called the Parametric Frequency Increased Generator (PFIG). Three generations of the device have been fabricated. It was first demonstrated using a larger bench-top prototype that had a functional volume of 3.7cm3. It generated a peak power of 558{micro}W and an average power of 39.5{micro}W at an input acceleration of 1g applied at 10 Hz. The performance of this device has still not been matched by any other reported work. It yielded the best power density and efficiency for any scavenger operating from low-frequency (<10Hz) vibrations. A second-generation device was then fabricated. It generated a peak power of 288{micro}W and an average power of 5.8{micro}W from an input acceleration of 9.8m/s{sup 2} at 10Hz. The device operates over a frequency range of 20Hz. The internal volume of the generator is 2.1cm{sup 3} (3.7cm{sup 3} including casing), half of a standard AA battery. Lastly, a piezoelectric version of the PFIG is currently being developed. This device clearly demonstrates one of the key features of the PFIG architecture, namely that it is suitable for MEMS integration, more so than resonant generators, by incorporating a brittle bulk piezoelectric ceramic. This is the first micro-scale piezoelectric generator capable of <10Hz operation. The

  2. Further assessment of scavenging feed resource base

    International Nuclear Information System (INIS)

    Sonaiya, E.B.; Dazogbo, J.S.; Olukosi, O.A.

    2002-01-01

    The scavenging feed resource base (SFRB) was estimated in four villages located in a rainforest ecozone in Nigeria. The average SFRB estimated for the villages was 110 kg dry weight/family flock/year. Productivity of the birds in the villages was low. A low survivability of chicks was detected indicating a lot of wastage of eggs that could have been used for human consumption. The SFRB was low in nutritive value with less than 2 g crude protein (CP) available to each bird daily. To more quantitatively describe the SFRB, the concept of using bird unit in determining what is available to each bird is suggested. This helped in evaluating at first glance the differential accessibility of each class of bird to the SFRB and assisted in strategic supplementation of the SFRB. The use of predictors of the SFRB could help in establishing prediction equation which would help in predicting the carrying capacity of the SFRB and in determining the optimum flock biomass more accurately. (author)

  3. Americans with Disabilities Act Scavenger Hunt

    Science.gov (United States)

    Ramsey, Ursula

    2018-01-01

    This article describes a scavenger hunt for Business Law students. Specifically, students compete in this scavenger hunt to identify accessible design features on campus to undergird their study of Title III of the Americans with Disabilities Act (ADA). Title III of the ADA prohibits public accommodations from discriminating on the basis of…

  4. Dielectric polymer: scavenging energy from human motion

    Science.gov (United States)

    Jean-Mistral, Claire; Basrour, Skandar; Chaillout, Jean-Jacques

    2008-03-01

    More and more sensors are embedded in human body for medical applications, for sport. The short lifetime of the batteries, available on the market, reveals a real problem of autonomy of these systems. A promising alternative is to scavenge the ambient energy such as the mechanical one. Up to now, few scavenging structures have operating frequencies compatible with ambient one. And, most of the developed structures are rigid and use vibration as mechanical source. For these reasons, we developed a scavenger that operates in a large frequency spectrum from quasi-static to dynamic range. This generator is fully flexible, light and does not hamper the human motion. Thus, we report in this paper an analytical model for dielectric generator with news electrical and mechanical characterization, and the development of an innovating application: scavenging energy from human motion. The generator is located on the knee and design to scavenge 0.1mJ per scavenging cycle at a frequency of 1Hz, enough to supply a low consumption system and with a poling voltage as low as possible to facilitate the power management. Our first prototype is a membrane with an area of 5*3cm and 31µm in thickness which scavenge 0.1mJ under 170V at constant charge Q.

  5. Peroxynitrite scavenging activity of herb extracts.

    Science.gov (United States)

    Choi, Hye Rhi; Choi, Jae Sue; Han, Yong Nam; Bae, Song Ja; Chung, Hae Young

    2002-06-01

    Peroxynitrite (ONOO(-)) is a cytotoxicant with strong oxidizing properties toward various cellular constituents, including sulphydryls, lipids, amino acids and nucleotides and can cause cell death, lipid peroxidation, carcinogenesis and aging. The aim of this study was to characterize ONOO(-) scavenging constituents from herbs. Twenty-eight herbs were screened for their ONOO(-) scavenging activities with the use of a fluorometric method. The potency of scavenging activity following the addition of authentic ONOO(-) was in the following order: witch hazel bark > rosemary > jasmine tea > sage > slippery elm > black walnut leaf > Queen Anne's lace > Linden flower. The extracts exhibited dose-dependent ONOO(-) scavenging activities. We found that witch hazel (Hamamelis virginiana L.) bark showed the strongest effect for scavenging ONOO(-) of the 28 herbs. Hamamelitannin, the major active component of witch hazel bark, was shown to have a strong ability to scavenge ONOO(-). It is suggested that hamamelitannin might be developed as an effective peroxynitrite scavenger for the prevention of ONOO(-) involved diseases. Copyright 2002 John Wiley & Sons, Ltd.

  6. Free radical scavenging window of infertile patients with polycystic ovary syndrome: correlation with embryo quality.

    Science.gov (United States)

    Huang, Bo; Li, Zhou; Ren, Xinling; Ai, Jihui; Zhu, Lixia; Jin, Lei

    2017-06-01

    The activity of free radicals in follicular fluid was related to ovarian responsiveness, in vitro fertilization (IVF), and embryo transfer success rate. However, studies analyzing the relationship between the free radical scavenging capacity and embryo quality of infertile women with polycystic ovarian syndrome (PCOS) were lacking. The aim of this study was to evaluate the relationship between the free radical scavenging window of women with PCOS and their embryo quality. The free radical scavenging capacity of follicular fluid from women with PCOS was determined by a,a-diphenyl-b-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzthiazoline-6-sulphonic acid) assay, superoxide radical, and reactive oxygen species (ROS) assay. In the DPPH and ROS assays, the follicular fluid from grades I and II embryos was significantly higher than the follicular fluid from grades III and IVembryos. The lower control limit of DPPH radical scavenging capacity and upper control limit of ROS level were 13.2% and 109.0 cps, respectively. The calculated lower control limit and upper control limit were further confirmed in the follicular fluid of embryos of all grades. These cut-off values of free radical scavenging activity of follicular fluid could assist embryologists in choosing the development of embryos in PCOS patients undergoing IVF.

  7. Scavenger receptors in homeostasis and immunity.

    Science.gov (United States)

    Canton, Johnathan; Neculai, Dante; Grinstein, Sergio

    2013-09-01

    Scavenger receptors were originally identified by their ability to recognize and to remove modified lipoproteins; however, it is now appreciated that they carry out a striking range of functions, including pathogen clearance, lipid transport, the transport of cargo within the cell and even functioning as taste receptors. The large repertoire of ligands recognized by scavenger receptors and their broad range of functions are not only due to the wide range of receptors that constitute this family but also to their ability to partner with various co-receptors. The ability of individual scavenger receptors to associate with different co-receptors makes their responsiveness extremely versatile. This Review highlights recent insights into the structural features that determine the function of scavenger receptors and the emerging role that these receptors have in immune responses, notably in macrophage polarization and in the pathogenesis of diseases such as atherosclerosis and Alzheimer's disease.

  8. Role of antioxidant scavenging enzymes and extracellular ...

    African Journals Online (AJOL)

    ChithrashreeGS

    2012-08-23

    Aug 23, 2012 ... peroxidase are two important antioxidant scavenging enzymes involved in ... Catalase was assayed using the method of Beers and Sizer. (1951) with .... yeast dextrose calcium carbonate agar (YDC) medium. Catalase and ...

  9. Flavonoids as scavengers of nitric oxide radical.

    NARCIS (Netherlands)

    van Acker, S.A.B.E.; Tromp, M.N.J.L.; Haenen, G.R.M.M.; van der Vijgh, W.J.F.; Bast, A.

    1995-01-01

    Flavonoids are a group of naturally occurring compounds used, e.g., in the treatment of vascular endothelial damage. They are known to be excellent scavengers of oxygen free radicals. Since the nitric oxide radical (

  10. Radical scavenging propensity of Cu2 +, Fe3 + complexes of flavonoids and in-vivo radical scavenging by Fe3 +-primuletin

    Science.gov (United States)

    Jabeen, Erum; Janjua, Naveed Kausar; Ahmed, Safeer; Murtaza, Iram; Ali, Tahir; Hameed, Shahid

    2017-01-01

    Cu2 + and Fe3 + complexes of three flavonoids (morin or mo, quercetin or quer and primuletin or prim) were synthesized with the objective of improving antioxidant capacities of flavonoids. The radical scavenging activities of pure flavonoids and their metal complexes were assayed to monitor their tendencies towards sequestering of radicals at physiological conditions. The scavenger potencies of metal-flavonoid complexes were significantly higher than those of the parent flavonoids. Further, influence of the solvent polarity on the radical capturing by flavonoids and their metal complexes was in favor for the polar solvent. Fe3 +-prim displayed its radical scavenging ability via up gradation of CAT and SOD activities in in-vivo antioxidant assays.

  11. In vitro anti-inflammatory and free radical scavenging activities of ...

    African Journals Online (AJOL)

    Methods: In vitro antioxidant activity was determined using free radical scavenging assays such as DPPH, ABTS and NO2. The antiinflammatory potential was carried out using inhibition of protein denaturation of egg albumin as a model of anti-inflammatory capacity. Results: Both the crude methanolic extract and saponins ...

  12. Boundary scavenging in the Pacific Ocean

    International Nuclear Information System (INIS)

    Anderson, R.F.; Lao, Y.; Broecker, W.S.; Trumbore, S.E.; Hofmann, H.J.; Wolfli, W.

    1990-01-01

    Concentrations of U, Th, 231 Pa and 10 Be were measured in Holocene sediments from two cores collected off the west coast of South America, two cores from the East Pacific Rise, two from the equatorial Pacific and one from the south Pacific central gyre. Our results, together with data from 5 cores reported in the literature, show that boundary scavenging plays a major role in the removal of 10 Be from the Pacific Ocean. Deposition rates of 10 Be at three margin sites are more than an order of magnitude greater than at sites of red clay accumulation in the deep central Pacific. Deposition of 231 Pa is 4 to 5-fold greater at the margin sites. The residence time of 10 Be with respect to chemical scavenging, defined as its inventory in the water column divided by its rate of removal to the sediments, varies regionally from >1000 years at the red-clay sites in the deep central Pacific to ∝100 years at the margin sites. Different factors control boundary scavenging of Pa and Be. For example, scavenging of 231 Pa is enhanced by metal-oxide coatings of particles, whereas this seems to have little influence on the scavenging of 10 Be. (orig.)

  13. Blood Glutamate Scavenging: Insight into Neuroprotection

    Directory of Open Access Journals (Sweden)

    Alexander Zlotnik

    2012-08-01

    Full Text Available Brain insults are characterized by a multitude of complex processes, of which glutamate release plays a major role. Deleterious excess of glutamate in the brain’s extracellular fluids stimulates glutamate receptors, which in turn lead to cell swelling, apoptosis, and neuronal death. These exacerbate neurological outcome. Approaches aimed at antagonizing the astrocytic and glial glutamate receptors have failed to demonstrate clinical benefit. Alternatively, eliminating excess glutamate from brain interstitial fluids by making use of the naturally occurring brain-to-blood glutamate efflux has been shown to be effective in various animal studies. This is facilitated by gradient driven transport across brain capillary endothelial glutamate transporters. Blood glutamate scavengers enhance this naturally occurring mechanism by reducing the blood glutamate concentration, thus increasing the rate at which excess glutamate is cleared. Blood glutamate scavenging is achieved by several mechanisms including: catalyzation of the enzymatic process involved in glutamate metabolism, redistribution of glutamate into tissue, and acute stress response. Regardless of the mechanism involved, decreased blood glutamate concentration is associated with improved neurological outcome. This review focuses on the physiological, mechanistic and clinical roles of blood glutamate scavenging, particularly in the context of acute and chronic CNS injury. We discuss the details of brain-to-blood glutamate efflux, auto-regulation mechanisms of blood glutamate, natural and exogenous blood glutamate scavenging systems, and redistribution of glutamate. We then propose different applied methodologies to reduce blood and brain glutamate concentrations and discuss the neuroprotective role of blood glutamate scavenging.

  14. Radical scavenging potentials of single and combinatorial herbal formulations in vitro

    Directory of Open Access Journals (Sweden)

    Okey A. Ojiako

    2016-04-01

    Full Text Available Reactive oxygen and nitrogen species (RONS are involved in deleterious/beneficial biological processes. The present study sought to investigate the capacity of single and combinatorial herbal formulations of Acanthus montanus, Emilia coccinea, Hibiscus rosasinensis, and Asystasia gangetica to act as superoxide radicals (SOR, hydrogen peroxide (HP, nitric oxide radical (NOR, hydroxyl radical (HR, and 2,2-diphenyl-1-picrylhydrazyl (DPPH radical antagonists using in vitro models. The herbal extracts were single herbal formulations (SHfs, double herbal formulations (DHfs, triple herbal formulations (THfs, and a quadruple herbal formulation (QHf. The phytochemical composition and radical scavenging capacity index (SCI of the herbal formulations were measured using standard methods. The flavonoids were the most abundant phytochemicals present in the herbal extracts. The SCI50 defined the concentration (μg/mL of herbal formulation required to scavenge 50% of the investigated radicals. The SHfs, DHfs, THfs, and QHf SCI50 against the radicals followed the order HR > SOR > DPPH radical > HP > NOR. Although the various herbal formulations exhibited ambivalent antioxidant activities in terms of their radical scavenging capabilities, a broad survey of the results of the present study showed that combinatorial herbal formulations (DHfs, THfs, and QHf appeared to exhibit lower radical scavenging capacities than those of the SHfs in vitro.

  15. Nature or Nurture? Gender Roles Scavenger Hunt

    Science.gov (United States)

    Whalen, Shannon; Maurer-Starks, Suanne

    2008-01-01

    The examination of gender roles and stereotypes and their subsequent impact on sexual behavior is a concept for discussion in many sex education courses in college and sex education units in high school. This analysis often leads to a discussion of the impact of nature vs. nurture on gender roles. The gender roles scavenger hunt is an interactive…

  16. Role of antioxidant scavenging enzymes and extracellular ...

    African Journals Online (AJOL)

    In the present work, we studied the role of antioxidant scavenging enzymes of plant pathogenic bacteria: catalase, ascorbate peroxidase and a virulence factor; extracelluar polysaccharide production in determining the virulence of Xanthomonas oryzae pv. oryzae (Xoo) isolates and its differential reaction to rice cultivars.

  17. Phytochemical screening, free radical scavenging and antibacterial ...

    African Journals Online (AJOL)

    Cassia sieberiana is a tropical plant, widely distributed throughout Sudan and Guinea savannah. It is used in traditional medicine for the treatment of malarial, cancer and stomach ache. The study was conducted to screen for phytochemicals, free radical scavenging and antibacterial potentials of the root bark.

  18. [In vitro anti-inflammatory and free radical scavenging activities of flavans from Ilex centrochinensis].

    Science.gov (United States)

    Li, Lu-jun; Yu, Li-juan; Li, Yan-ci; Liu, Meng-yuan; Wu, Zheng-zhi

    2015-04-01

    This study was carried out to evaluate the anti-inflammatory and free radical scavenging activities of flavans from flex centrochinensis S. Y. Hu in vitro and their structure-activity relationship. LPS-stimulated RAW 264.7 macrophage was used as inflammatory model. MTT assay for cell availability, Griess reaction for nitric oxide (NO) production, the content of TNF-alpha, IL-1beta, IL-6 and PGE, were detected with ELISA kits; DPPH, superoxide anion and hydroxyl free radicals scavenging activities were also investigated. According to the result, all flavans tested exhibited anti-inflammatory effect in different levels. Among them, compounds 1, 3, 4 and 6 showed potent anti-inflammatory effect through the inhibition of NO, TNF-alpha, IL-lp and IL-6, of which 1 was the most effective inhibitor, however, 2 and 5 were relatively weak or inactive. The order of free radical scavenging activities was similar to that of anti-inflammatory activities. Therefore, these results suggest that 3, 4 and 6, especially of 1, were,in part responsible for the anti-inflammatory and free radical scavenging activity of Ilex centrochinensis. Hydroxyl group at 4'-position of B-ring plays an important role in the anti-inflammatory and free radical scavenging capacities.

  19. Free radical scavenging potential and HPTLC analysis of Indigofera tinctoria linn (Fabaceae

    Directory of Open Access Journals (Sweden)

    Sakthivel Srinivasan

    2016-04-01

    Full Text Available The objective of this study was to evaluate the free radical scavenging potential and high performance thin layer chromatography (HPTLC fingerprinting of Indigofera tinctoria (I. tinctoria. Phytochemical analysis was carried out using standard methods, and free radical scavenging activity of the plant was determined using 2,2-diphenyl-1-picrylhydrazy (DPPH, nitric oxide (NO and superoxide anion (O2− radical scavenging capacities. HPTLC plate was kept in CAMAG TLC Scanner 3 and the Rf values at fingerprint data were recorded by WINCATS software. Aqueous extract of I. tinctoria reliably showed the total phenolics (267.2±2.42 mg/g, flavonoids (75.43±3.36 mg/g and antioxidants (349.11±8.04 mg/g. The extract was found to have DPPH (52.08%, NO (23.12% and O2− (26.79% scavenging activities at the concentration of 250 μg/mL and the results were statistically significant compared with ascorbic acid standard (p<0.05. HPTLC results confirmed that the extract contained several potential active components such as phenols, flavonoids, saponins and terpenoids as the slides revealed multi-colored bands of varying intensities. This study confirmed that the plant had multipotential antioxidant and free radicals scavenging activities.

  20. Scavenging and recombination kinetics in a radiation spur: The successive ordered scavenging events

    Science.gov (United States)

    Al-Samra, Eyad H.; Green, Nicholas J. B.

    2018-03-01

    This study describes stochastic models to investigate the successive ordered scavenging events in a spur of four radicals, a model system based on a radiation spur. Three simulation models have been developed to obtain the probabilities of the ordered scavenging events: (i) a Monte Carlo random flight (RF) model, (ii) hybrid simulations in which the reaction rate coefficient is used to generate scavenging times for the radicals and (iii) the independent reaction times (IRT) method. The results of these simulations are found to be in agreement with one another. In addition, a detailed master equation treatment is also presented, and used to extract simulated rate coefficients of the ordered scavenging reactions from the RF simulations. These rate coefficients are transient, the rate coefficients obtained for subsequent reactions are effectively equal, and in reasonable agreement with the simple correction for competition effects that has recently been proposed.

  1. Intracellular ROS protection efficiency and free radical-scavenging activity of curcumin.

    Directory of Open Access Journals (Sweden)

    Abolfazl Barzegar

    Full Text Available Curcumin has many pharmaceutical applications, many of which arise from its potent antioxidant properties. The present research examined the antioxidant activities of curcumin in polar solvents by a comparative study using ESR, reduction of ferric iron in aqueous medium and intracellular ROS/toxicity assays. ESR data indicated that the steric hindrance among adjacent big size groups within a galvinoxyl molecule limited the curcumin to scavenge galvinoxyl radicals effectively, while curcumin showed a powerful capacity for scavenging intracellular smaller oxidative molecules such as H₂O₂, HO•, ROO•. Cell viability and ROS assays demonstrated that curcumin was able to penetrate into the polar medium inside the cells and to protect them against the highly toxic and lethal effects of cumene hydroperoxide. Curcumin also showed good electron-transfer capability, with greater activity than trolox in aqueous solution. Curcumin can readily transfer electron or easily donate H-atom from two phenolic sites to scavenge free radicals. The excellent electron transfer capability of curcumin is because of its unique structure and different functional groups, including a β-diketone and several π electrons that have the capacity to conjugate between two phenyl rings. Therfore, since curcumin is inherently a lipophilic compound, because of its superb intracellular ROS scavenging activity, it can be used as an effective antioxidant for ROS protection within the polar cytoplasm.

  2. Investigation into Seasonal Scavenging Patterns of Raccoons on Human Decomposition.

    Science.gov (United States)

    Jeong, Yangseung; Jantz, Lee Meadows; Smith, Jake

    2016-03-01

    Although raccoons are known as one of the most common scavengers in the U.S., scavenging by these animals has seldom been studied in terms of forensic significance. In this research, the seasonal pattern of raccoon scavenging and its effect on human decomposition was investigated using 178 human cadavers placed at the Anthropological Research Facility (ARF) of the University of Tennessee, Knoxville (UTK) between February 2011 and December 2013. The results reveal that (i) the frequency of scavenging increases during summer, (ii) scavenging occurs relatively immediately and lasts shorter in summer months, and (iii) scavenging influences the decomposition process by hollowing limbs and by disturbing insect activities, both of which eventually increases the chance of mummification on the affected body. This information is expected to help forensic investigators identify raccoon scavenging as well as make a more precise interpretation of the effect of raccoon scavenging on bodies at crime scenes. © 2015 American Academy of Forensic Sciences.

  3. Precipitation scavenging of tritiated water vapour (HTO)

    International Nuclear Information System (INIS)

    Ogram, G.L.

    1985-10-01

    Precipitation scavenging (or washout) is an important mechanism for the removal of HTO from the atmosphere. Methods of parameterizing the depletion of a plume of HTO released to the atmosphere are examined. Simple approaches, commonly used for atmospheric transport modelling purposes, such as the use of a constant washout coefficient or washout ratio, or the use of parameters based on equilibrium assumptions, are often not justified. It is shown that these parameters depend strongly on ambient temperature and plume dimensions, as well as rainfall rate. An approximate expression for washout ratio, as a function of these variables, is developed, and it is shown that near equilibrium washout conditions are only expected to hold at long plume travel distances. A possible method of treating scavenging by snow is also suggested

  4. Mobile vapor recovery and vapor scavenging unit

    International Nuclear Information System (INIS)

    Stokes, C.A.; Steppe, D.E.

    1991-01-01

    This patent describes a mobile anti- pollution apparatus, for the recovery of hydrocarbon emissions. It comprises a mobile platform upon which is mounted a vapor recovery unit for recovering vapors including light hydrocarbons, the vapor recovery unit having an inlet and an outlet end, the inlet end adapted for coupling to an external source of hydrocarbon vapor emissions to recover a portion of the vapors including light hydrocarbons emitted therefrom, and the outlet end adapted for connection to a means for conveying unrecovered vapors to a vapor scavenging unit, the vapor scavenging unit comprising an internal combustion engine adapted for utilizing light hydrocarbon in the unrecovered vapors exiting from the vapor recovery unit as supplemental fuel

  5. Scavenger Receptors and Resistance to Inhaled Allergens

    Science.gov (United States)

    2010-02-01

    throughput manner which will enable future studies. We plan to continue two especially interesting aspects of these studies. First, the epigenetic control...directs mod- ified proteins to antigen presentation. Eur. J. Immunol. 29: 512–521. 30. Granucci, F., F. Petralia, M. Urbano , S. Citterio, F. Di Tota, L...11 Suppl:S32-6. 50. Granucci F, Petralia F, Urbano M, Citterio S, Di Tota F, Santambrogio L, Ricciardi-Castagnoli P: The scavenger receptor MARCO

  6. Energy scavenging sources for biomedical sensors

    International Nuclear Information System (INIS)

    Romero, E; Warrington, R O; Neuman, M R

    2009-01-01

    Energy scavenging has increasingly become an interesting option for powering electronic devices because of the almost infinite lifetime and the non-dependence on fuels for energy generation. Moreover, the rise of wireless technologies promises new applications in medical monitoring systems, but these still face limitations due to battery lifetime and size. A trade-off of these two factors has typically governed the size, useful life and capabilities of an autonomous system. Energy generation from sources such as motion, light and temperature gradients has been established as commercially viable alternatives to batteries for human-powered flashlights, solar calculators, radio receivers and thermal-powered wristwatches, among others. Research on energy harvesting from human activities has also addressed the feasibility of powering wearable or implantable systems. Biomedical sensors can take advantage of human-based activities as the energy source for energy scavengers. This review describes the state of the art of energy scavenging technologies for powering sensors and instrumentation of physiological variables. After a short description of the human power and the energy generation limits, the different transduction mechanisms, recent developments and challenges faced are reviewed and discussed. (topical review)

  7. Scavenger receptors in human airway epithelial cells: role in response to double-stranded RNA.

    Directory of Open Access Journals (Sweden)

    Audrey Dieudonné

    Full Text Available Scavenger receptors and Toll-like receptors (TLRs cooperate in response to danger signals to adjust the host immune response. The TLR3 agonist double stranded (dsRNA is an efficient activator of innate signalling in bronchial epithelial cells. In this study, we aimed at defining the role played by scavenger receptors expressed by bronchial epithelial cells in the control of the innate response to dsRNA both in vitro and in vivo. Expression of several scavenger receptor involved in pathogen recognition was first evaluated in human bronchial epithelial cells in steady-state and inflammatory conditions. Their implication in the uptake of dsRNA and the subsequent cell activation was evaluated in vitro by competition with ligand of scavenger receptors including maleylated ovalbumin and by RNA silencing. The capacity of maleylated ovalbumin to modulate lung inflammation induced by dsRNA was also investigated in mice. Exposure to tumor necrosis factor-α increased expression of the scavenger receptors LOX-1 and CXCL16 and the capacity to internalize maleylated ovalbumin, whereas activation by TLR ligands did not. In contrast, the expression of SR-B1 was not modulated in these conditions. Interestingly, supplementation with maleylated ovalbumin limited dsRNA uptake and inhibited subsequent activation of bronchial epithelial cells. RNA silencing of LOX-1 and SR-B1 strongly blocked the dsRNA-induced cytokine production. Finally, administration of maleylated ovalbumin in mice inhibited the dsRNA-induced infiltration and activation of inflammatory cells in bronchoalveolar spaces and lung draining lymph nodes. Together, our data characterize the function of SR-B1 and LOX-1 in bronchial epithelial cells and their implication in dsRNA-induced responses, a finding that might be relevant during respiratory viral infections.

  8. A Targeted "Capture" and "Removal" Scavenger toward Multiple Pollutants for Water Remediation based on Molecular Recognition.

    Science.gov (United States)

    Wang, Jie; Shen, Haijing; Hu, Xiaoxia; Li, Yan; Li, Zhihao; Xu, Jinfan; Song, Xiufeng; Zeng, Haibo; Yuan, Quan

    2016-03-01

    For the water remediation techniques based on adsorption, the long-standing contradictories between selectivity and multiple adsorbability, as well as between affinity and recyclability, have put it on weak defense amid more and more severe environment crisis. Here, a pollutant-targeting hydrogel scavenger is reported for water remediation with both high selectivity and multiple adsorbability for several pollutants, and with strong affinity and good recyclability through rationally integrating the advantages of multiple functional materials. In the scavenger, aptamers fold into binding pockets to accommodate the molecular structure of pollutants to afford perfect selectivity, and Janus nanoparticles with antibacterial function as well as anisotropic surfaces to immobilize multiple aptamers allow for simultaneously handling different kinds of pollutants. The scavenger exhibits high efficiencies in removing pollutants from water and it can be easily recycled for many times without significant loss of loading capacities. Moreover, the residual concentrations of each contaminant are well below the drinking water standards. Thermodynamic behavior of the adsorption process is investigated and the rate-controlling process is determined. Furthermore, a point of use device is constructed and it displays high efficiency in removing pollutants from environmental water. The scavenger exhibits great promise to be applied in the next generation of water purification systems.

  9. Electrochemically reduced water exerts superior reactive oxygen species scavenging activity in HT1080 cells than the equivalent level of hydrogen-dissolved water.

    Directory of Open Access Journals (Sweden)

    Takeki Hamasaki

    Full Text Available Electrochemically reduced water (ERW is produced near a cathode during electrolysis and exhibits an alkaline pH, contains richly dissolved hydrogen, and contains a small amount of platinum nanoparticles. ERW has reactive oxygen species (ROS-scavenging activity and recent studies demonstrated that hydrogen-dissolved water exhibits ROS-scavenging activity. Thus, the antioxidative capacity of ERW is postulated to be dependent on the presence of hydrogen levels; however, there is no report verifying the role of dissolved hydrogen in ERW. In this report, we clarify whether the responsive factor for antioxidative activity in ERW is dissolved hydrogen. The intracellular ROS scavenging activity of ERW and hydrogen-dissolved water was tested by both fluorescent stain method and immuno spin trapping assay. We confirm that ERW possessed electrolysis intensity-dependent intracellular ROS-scavenging activity, and ERW exerts significantly superior ROS-scavenging activity in HT1080 cells than the equivalent level of hydrogen-dissolved water. ERW retained its ROS-scavenging activity after removal of dissolved hydrogen, but lost its activity when autoclaved. An oxygen radical absorbance capacity assay, the 2,2-diphenyl-1-picrylhydrazyl assay and chemiluminescence assay could not detect radical-scavenging activity in both ERW and hydrogen-dissolved water. These results indicate that ERW contains electrolysis-dependent hydrogen and an additional antioxidative factor predicted to be platinum nanoparticles.

  10. Differential Scavenging Among Pig, Rabbit, and Human Subjects.

    Science.gov (United States)

    Steadman, Dawnie Wolfe; Dautartas, Angela; Kenyhercz, Michael W; Jantz, Lee M; Mundorff, Amy; Vidoli, Giovanna M

    2018-04-12

    Different animal species have been used as proxies for human remains in decomposition studies for decades, although few studies have sought to validate their use in research aimed at estimating the postmortem interval. This study examines 45 pig, rabbit, and human subjects placed in three seasonal trials at the Anthropology Research Facility. In an earlier paper, we found that overall decomposition trends did vary between species that could be due to differential insect and scavenger behavior. This study specifically examines if scavenger behavior differs by carrion species. Daily photographs, game camera photographs, written observations, and Total Body Score (TBS) documented scavenging and decomposition changes. Results show that raccoons were the most commonly observed vertebrate scavenger, that scavenging was most extensive in winter, and that certain human subjects were preferred over other humans and all non-human subjects. Finally, scavenging activity greatly reduces the accuracy of postmortem interval estimates based on TBS. © 2018 American Academy of Forensic Sciences.

  11. Free-Radical-Scavenging, Antityrosinase, and Cellular Melanogenesis Inhibitory Activities of Synthetic Isoflavones.

    Science.gov (United States)

    Lu, Tzy-Ming; Ko, Horng-Huey; Ng, Lean-Teik; Hsieh, Yen-Pin

    2015-06-01

    In this study, we examined the potential of synthetic isoflavones for application in cosmeceuticals. Twenty-five isoflavones were synthesized and their capacities of free-radical-scavenging and mushroom tyrosinase inhibition, as well as their impact on cell viability of B16F10 murine melanoma cells and HaCaT human keratinocytes were evaluated. Isoflavones that showed significant mushroom tyrosinase inhibitory activities were further studied on reduction of cellular melanin formation and antityrosinase activities in B16F10 melanocytes in vitro. Among the isoflavones tested, 6-hydroxydaidzein (2) was the strongest scavenger of both ABTS(.+) and DPPH(.) radicals with SC50 values of 11.3 ± 0.3 and 9.4 ± 0.1 μM, respectively. Texasin (20) exhibited the most potent inhibition of mushroom tyrosinase (IC50 14.9 ± 4.5 μM), whereas retusin (17) showed the most efficient inhibition both of cellular melanin formation and antityrosinase activity in B16F10 melanocytes, respectively. In summary, both retusin (17) and texasin (20) exhibited potent free-radical-scavenging capacities as well as efficient inhibition of cellular melanogenesis, suggesting that they are valuable hit compounds with potential for advanced cosmeceutical development. Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.

  12. Radical scavenging activity of crude polysaccharides from Camellia sinensis

    Directory of Open Access Journals (Sweden)

    Yang Fan

    2011-01-01

    Full Text Available A preparation of crude polysaccharides (TPS was isolated from Camellia sinensis by precipitation and ultrafiltration. TPS1, TPS2, and TPS3 had molecular weights of 240, 21.4, and 2.46 kDa, respectively. The radical scavenging activities of TPS were evaluated by DPPH free radical, hydroxyl radical and superoxide radical scavenging. These results revealed that TPS exhibited strong radical scavenging activity in a concentration-dependent manner. TPS3 with lowest molecular weight showed a higher radical scavenging activity.

  13. Isolation and characterisation of in vitro and cellular free radical scavenging peptides from corn peptide fractions.

    Science.gov (United States)

    Wang, Liying; Ding, Long; Wang, Ying; Zhang, Yan; Liu, Jingbo

    2015-02-16

    Corn gluten meal, a corn processing industry by-product, is a good source for the preparation of bioactive peptides due to its special amino acid composition. In the present study, the in vitro and cellular free radical scavenging activities of corn peptide fractions (CPFs) were investigated. Results indicated that CPF1 (molecular weight less than 1 kDa) and CPF2 (molecular weight between 1 and 3 kDa) exhibited good hydroxyl radical, superoxide anion radical and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonicacid) diammonium salt (ABTS) radical scavenging activity and oxygen radical absorbance capacity (ORAC). Meanwhile, the in vitro radical scavenging activity of CPF1 was slightly higher than that of CPF2. Both CPF1 and CPF2 also exhibited significant cytoprotective effects and intracellular reactive oxygen species scavenging activity in Caco-2 cells exposed to hydrogen peroxide (H2O2). The amino acid composition analysis revealed that the CPF were rich in hydrophobic amino acids, which comprised of more than 45% of total amino acids. An antioxidant peptide sequence of Tyr-Phe-Cys-Leu-Thr (YFCLT) was identified from CPF1 using matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (MALDI TOF/TOF MS). The YFCLT exhibited excellent ABTS radical scavenging activity with a 50% effective concentration (EC50) value of 37.63 µM, which was much lower than that of Trolox. In conclusion, corn gluten meal might be a good source to prepare antioxidant peptides.

  14. Free radical scavenging activities of yellow gentian (Gentiana lutea L.) measured by electron spin resonance.

    Science.gov (United States)

    Kusar, A; Zupancic, A; Sentjurc, M; Baricevic, D

    2006-10-01

    Yellow gentian (Gentiana lutea L.) is a herbal species with a long-term use in traditional medicine due to its digestive and stomachic properties. This paper presents an investigation of the free radical scavenging activity of methanolic extracts of yellow gentian leaves and roots in two different systems using electron spin resonance (ESR) spectrometry. Assays were based on the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the superoxide radicals (O2*-) generated by the xanthine/xanthine oxidase (X/XO) system. The results of gentian methanolic extracts were compared with the antioxidant capacity of synthetic antioxidant butylated hydroxyanisole (BHA). This study proves that yellow gentian leaves and roots exhibit considerable antioxidant properties, expressed either by their capability to scavenge DPPH or superoxide radicals.

  15. Rain scavenging studies. Progress report No. 11

    International Nuclear Information System (INIS)

    Dingle, A.N.

    1975-05-01

    The modeling of convective storm scavenging processes is going forward on two distinct fronts. The first of these relates to the microphysical processes, particularly to the study of their response to micro-dynamical components of the convective circulation. It is found that the droplet size spectra generated are responsive to variations of vertical velocity due to turbulence within the cloud and to humidity variations due to entrainment processes. Both sets of variations give responses that differ for different amplitudes and frequencies, i.e., rapid, small-amplitude eddies appear to enhance small-droplet development, whereas slow, large-amplitude oscillations tend to enhance large-droplet development. An allied study of the assumptions used in the microphysical equations is also being made. The second modeling effort is addressed to the problem of three-dimensional representation of convective dynamics. Equations are presented, and some of the problems under attack are discussed

  16. Biological activity of clovers - free radical scavenging ability and antioxidant action of six Trifolium species.

    Science.gov (United States)

    Kolodziejczyk-Czepas, Joanna; Nowak, Pawel; Kowalska, Iwona; Stochmal, Anna

    2014-10-01

    Clovers were chosen on the basis of traditional medicine recommendations, agricultural value, or available information on their promising chemical profiles. This study evaluates and compares free radical scavenging and antioxidant properties of six clover species: Trifolium alexandrinum L. (Leguminosae), Trifolium fragiferum L., Trifolium hybridum L., Trifolium incarnatum L., Trifolium resupinatum var. majus Boiss., and Trifolium resupinatum var. resupinatum L. Free radical scavenging activity of the extracts (1.5-50 µg/ml) was estimated by reduction of 1,1-diphenyl-2-picrylhydrazyl (DPPH(•)) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic) acid (ABTS(•)) radicals. The Trifolium extract effects on total antioxidant capacity of blood plasma were determined by the reduction of ABTS(•+) and DPPH(•) radicals, as well as with the use of the ferric reducing ability of plasma (FRAP) assay. The UPLC analysis of chemical profiles of the examined extracts showed the presence of three or four groups of phenolic substances, including phenolic acids, clovamides, isoflavones, and other flavonoids. The measurements of free radical scavenging and ferric reducing ability of the examined clover extracts revealed the strongest effect for T. alexandrinum. Furthermore, antioxidant activity assays in human plasma have shown protective effects of all extracts against peroxynitrite-induced reduction of total antioxidant capacity. Trifolium plants may be a rich source of bioactive substances with antioxidant properties. The examined extracts displayed free radical scavenging action and partly protected blood plasma against peroxynitrite-induced oxidative stress; however, the beneficial effects of T. alexandrinum and T. incarnatum seem to be slightly higher.

  17. Carcass Type Affects Local Scavenger Guilds More than Habitat Connectivity.

    Directory of Open Access Journals (Sweden)

    Zachary H Olson

    Full Text Available Scavengers and decomposers provide an important ecosystem service by removing carrion from the environment. Scavenging and decomposition are known to be temperature-dependent, but less is known about other factors that might affect carrion removal. We conducted an experiment in which we manipulated combinations of patch connectivity and carcass type, and measured responses by local scavenger guilds along with aspects of carcass depletion. We conducted twelve, 1-month trials in which five raccoon (Procyon lotor, Virginia opossum (Didelphis virginiana, and domestic rabbit (Oryctolagus spp. carcasses (180 trials total were monitored using remote cameras in 21 forest patches in north-central Indiana, USA. Of 143 trials with complete data, we identified fifteen species of vertebrate scavengers divided evenly among mammalian (N = 8 and avian species (N = 7. Fourteen carcasses (9.8% were completely consumed by invertebrates, vertebrates exhibited scavenging behavior at 125 carcasses (87.4%, and four carcasses (2.8% remained unexploited. Among vertebrates, mammals scavenged 106 carcasses, birds scavenged 88 carcasses, and mammals and birds scavenged 69 carcasses. Contrary to our expectations, carcass type affected the assemblage of local scavenger guilds more than patch connectivity. However, neither carcass type nor connectivity explained variation in temporal measures of carcass removal. Interestingly, increasing richness of local vertebrate scavenger guilds contributed moderately to rates of carrion removal (≈6% per species increase in richness. We conclude that scavenger-specific differences in carrion utilization exist among carcass types and that reliable delivery of carrion removal as an ecosystem service may depend on robust vertebrate and invertebrate communities acting synergistically.

  18. Carcass Type Affects Local Scavenger Guilds More than Habitat Connectivity

    Science.gov (United States)

    Olson, Zachary H.; Beasley, James C.; Rhodes, Olin E.

    2016-01-01

    Scavengers and decomposers provide an important ecosystem service by removing carrion from the environment. Scavenging and decomposition are known to be temperature-dependent, but less is known about other factors that might affect carrion removal. We conducted an experiment in which we manipulated combinations of patch connectivity and carcass type, and measured responses by local scavenger guilds along with aspects of carcass depletion. We conducted twelve, 1-month trials in which five raccoon (Procyon lotor), Virginia opossum (Didelphis virginiana), and domestic rabbit (Oryctolagus spp.) carcasses (180 trials total) were monitored using remote cameras in 21 forest patches in north-central Indiana, USA. Of 143 trials with complete data, we identified fifteen species of vertebrate scavengers divided evenly among mammalian (N = 8) and avian species (N = 7). Fourteen carcasses (9.8%) were completely consumed by invertebrates, vertebrates exhibited scavenging behavior at 125 carcasses (87.4%), and four carcasses (2.8%) remained unexploited. Among vertebrates, mammals scavenged 106 carcasses, birds scavenged 88 carcasses, and mammals and birds scavenged 69 carcasses. Contrary to our expectations, carcass type affected the assemblage of local scavenger guilds more than patch connectivity. However, neither carcass type nor connectivity explained variation in temporal measures of carcass removal. Interestingly, increasing richness of local vertebrate scavenger guilds contributed moderately to rates of carrion removal (≈6% per species increase in richness). We conclude that scavenger-specific differences in carrion utilization exist among carcass types and that reliable delivery of carrion removal as an ecosystem service may depend on robust vertebrate and invertebrate communities acting synergistically. PMID:26886299

  19. Carcass Type Affects Local Scavenger Guilds More than Habitat Connectivity.

    Science.gov (United States)

    Olson, Zachary H; Beasley, James C; Rhodes, Olin E

    2016-01-01

    Scavengers and decomposers provide an important ecosystem service by removing carrion from the environment. Scavenging and decomposition are known to be temperature-dependent, but less is known about other factors that might affect carrion removal. We conducted an experiment in which we manipulated combinations of patch connectivity and carcass type, and measured responses by local scavenger guilds along with aspects of carcass depletion. We conducted twelve, 1-month trials in which five raccoon (Procyon lotor), Virginia opossum (Didelphis virginiana), and domestic rabbit (Oryctolagus spp.) carcasses (180 trials total) were monitored using remote cameras in 21 forest patches in north-central Indiana, USA. Of 143 trials with complete data, we identified fifteen species of vertebrate scavengers divided evenly among mammalian (N = 8) and avian species (N = 7). Fourteen carcasses (9.8%) were completely consumed by invertebrates, vertebrates exhibited scavenging behavior at 125 carcasses (87.4%), and four carcasses (2.8%) remained unexploited. Among vertebrates, mammals scavenged 106 carcasses, birds scavenged 88 carcasses, and mammals and birds scavenged 69 carcasses. Contrary to our expectations, carcass type affected the assemblage of local scavenger guilds more than patch connectivity. However, neither carcass type nor connectivity explained variation in temporal measures of carcass removal. Interestingly, increasing richness of local vertebrate scavenger guilds contributed moderately to rates of carrion removal (≈6% per species increase in richness). We conclude that scavenger-specific differences in carrion utilization exist among carcass types and that reliable delivery of carrion removal as an ecosystem service may depend on robust vertebrate and invertebrate communities acting synergistically.

  20. Antioxidant capacity of anthocyanins from acerola genotypes

    Directory of Open Access Journals (Sweden)

    Vera Lúcia Arroxelas Galvão De Lima

    2011-03-01

    Full Text Available Anthocyanins from 12 acerola genotypes cultivated at the Active Germplasm Bank at Federal Rural University of Pernambuco were isolated for antioxidant potential evaluation. The antioxidant activity and radical scavenging capacity of the anthocyanin isolates were measured according to the β-carotene bleaching method and 1,1-diphenyl-2-picrylhydrazyl (DPPH free radical scavenging assay, respectively. The antioxidant activity varied from 25.58 to 47.04% at 0.2 mg.mL-1, and it was measured using the β-carotene bleaching method. The free radical scavenging capacity increased according to the increase in concentration and reaction time by the DPPH assay. At 16.7 μg.mL-1 concentration and after 5 minutes and 2 hours reaction time, the percentage of scavenged radicals varied from 36.97 to 63.92% and 73.27 to 94.54%, respectively. Therefore, the antioxidant capacity of acerola anthocyanins varied amongst acerola genotypes and methods used. The anthocyanins present in this fruit may supply substantial dietary source of antioxidant which may promote health and produce disease prevention effects.

  1. Nitric oxide radical scavenging potential of some Elburz medicinal ...

    African Journals Online (AJOL)

    Some plants scavenge nitric oxide (NO) with high affinity. For this purpose, forty extracts from 26 medicinal plants, growing extensively in Elburz mountains, were evaluated for their NO scavenging activity. Total phenolic and flavonoid contents of these extracts were also measured by Folin Ciocalteu and AlCl3 colorimetric ...

  2. Free Radical Scavenging Activities of Methanol Extract and ...

    African Journals Online (AJOL)

    Michael Horsfall

    fractions were subjected to in vitro antioxidant evaluation using the DPPH free radical scavenging ... The crude extract has IC-50 value for radical scavenging activity of 5μg/mL which was .... effective concentration of the sample that is required.

  3. Modeling of an Integrated Electromagnetic Generator for Energy Scavenging

    NARCIS (Netherlands)

    Lu, J.; Kovalgin, Alexeij Y.; Schmitz, Jurriaan

    2007-01-01

    The ubiquitous deploying of wireless electronic devices due to pervasive computing results in the idea of Energy Scavenging, i.e., harvesting ambient energy from surroundings of the electronic devices. As an approach to possible practical realization of such an energy scavenger, we aim at the

  4. Radical Scavenging Efficacy of Thiol Capped Silver Nanoparticles

    Indian Academy of Sciences (India)

    aSchool of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur 492 010, India. bDepartment of ... of nanosilver in foods, health care and consumer products as antimi- ... of the radical scavenging behavior of thiolated antiox- idants (alone) and ..... case of GSH@AgNPs; DPPH scavenging activity was found to be ...

  5. Identification of Radical Scavengers in Sweet Grass (Hierochloe odorata)

    NARCIS (Netherlands)

    Pukalskas, A.; Beek, van T.A.; Venskutonis, R.P.; Linssen, J.P.H.; Veldhuizen, van A.; Groot, de Æ.

    2002-01-01

    Extracts from aerial parts of sweet grass (Hierochloe odorata) were active DPPH free radical scavengers, The active compounds were detected in extract fractions using HPLC with on-line radical scavenging detection. After multistep fractionation of the extract, two new natural products possessing

  6. Characterization and DPPH Radical Scavenging Activity of Gallic ...

    African Journals Online (AJOL)

    Characterization and DPPH Radical Scavenging Activity of Gallic Acid-Lecithin Complex. C Liu, C Chen, H Ma, E Yuan, Q Li. Abstract. Purpose: To investigate the physicochemical properties and DPPH radical scavenging activity of gallic acid–lecithin complex. Methods: The complex of gallic acid with lecithin was prepared ...

  7. Functionalized graphene quantum dots loaded with free radicals combined with liquid chromatography and tandem mass spectrometry to screen radical scavenging natural antioxidants from Licorice and Scutellariae.

    Science.gov (United States)

    Wang, Guoying; Niu, XiuLi; Shi, Gaofeng; Chen, Xuefu; Yao, Ruixing; Chen, Fuwen

    2014-12-01

    A novel screening method was developed for the detection and identification of radical scavenging natural antioxidants based on a free radical reaction combined with liquid chromatography with tandem mass spectrometry. Functionalized graphene quantum dots were prepared for loading free radicals in the complex screening system. The detection was performed with and without a preliminary exposure of the samples to specific free radicals on the functionalized graphene quantum dots, which can facilitate charge transfer between free radicals and antioxidants. The difference in chromatographic peak areas was used to identify potential antioxidants. This is a novel approach to simultaneously evaluate the antioxidant power of a component versus a free radical, and to identify it in a vegetal matrix. The structures of the antioxidants in the samples were identified using tandem mass spectrometry and comparison with standards. Fourteen compounds were found to possess potential antioxidant activity, and their free radical scavenging capacities were investigated. The order of scavenging capacity of 14 compounds was compared according to their free radical scavenging rate. 4',5,6,7-Tetrahydroxyflavone (radical scavenging rate: 0.05253 mL mg(-1) s(-1) ) showed the strongest capability for scavenging free radicals. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Effects of vulture exclusion on carrion consumption by facultative scavengers.

    Science.gov (United States)

    Hill, Jacob E; DeVault, Travis L; Beasley, James C; Rhodes, Olin E; Belant, Jerrold L

    2018-03-01

    Vultures provide an essential ecosystem service through removal of carrion, but globally, many populations are collapsing and several species are threatened with extinction. Widespread declines in vulture populations could increase the availability of carrion to other organisms, but the ways facultative scavengers might respond to this increase have not been thoroughly explored. We aimed to determine whether facultative scavengers increase carrion consumption in the absence of vulture competition and whether they are capable of functionally replacing vultures in the removal of carrion biomass from the landscape. We experimentally excluded 65 rabbit carcasses from vultures during daylight hours and placed an additional 65 carcasses that were accessible to vultures in forested habitat in South Carolina, USA during summer (June-August). We used motion-activated cameras to compare carrion use by facultative scavenging species between the experimental and control carcasses. Scavenging by facultative scavengers did not increase in the absence of competition with vultures. We found no difference in scavenger presence between control carcasses and those from which vultures were excluded. Eighty percent of carcasses from which vultures were excluded were not scavenged by vertebrates, compared to 5% of carcasses that were accessible to vultures. At the end of the 7-day trials, there was a 10.1-fold increase in the number of experimental carcasses that were not fully scavenged compared to controls. Facultative scavengers did not functionally replace vultures during summer in our study. This finding may have been influenced by the time of the year in which the study took place, the duration of the trials, and the spacing of carcass sites. Our results suggest that under the warm and humid conditions of our study, facultative scavengers would not compensate for loss of vultures. Carcasses would persist longer in the environment and consumption of carrion would likely shift from

  9. Scavenger hunt in the CERN Computing Centre

    CERN Multimedia

    CERN Bulletin

    2013-01-01

    Hidden among the racks of servers and disks in the CERN Computing Centre, you’ll find Hawaiian dancers, space aliens, gorillas… all LEGO® figurines! These characters were placed about the Centre for the arrival of Google’s Street View team for the world to discover.   PLEASE NOTE THAT THE COMPETITION IS OVER. ONLY FOR REFERENCE, HERE IS THE ORIGINAL ARTICLE. We’re pleased to announce our first global scavenger hunt! Spot three LEGO® figurines using Google’s Street View and you’ll be entered to win a gift of your choice from our CERN Gift Guide. A LEGO® figurine in the CERN Computing Centre, as seen on Google Street View. Here are the details: Find at least three LEGO® figurines hidden around the CERN Computing Centre using Google Street View.   Take screencaps of the figurines and e-mail the pictures to TreasureHunt-ComputingCentre@cern.ch. This email is no longer active.   The...

  10. HUNT: Scavenger Hunt with Augmented Reality

    Directory of Open Access Journals (Sweden)

    Yan Lu

    2015-04-01

    Full Text Available This project shows a creative approach to the familiar scavenger hunt game. It involved the implementation of an iPhone application, HUNT, with Augmented Reality (AR capability for the users to play the game as well as an administrative website that game organizers can use to create and make available games for users to play. Using the HUNT mobile app, users will first make a selection from a list of games, and they will then be shown a list of objects that they must seek. Once the user finds a correct object and scans it with the built-in camera on the smartphone, the application will attempt to verify if it is the correct object and then display associated multi-media AR content that may include images and videos overlaid on top of real world views. HUNT not only provides entertaining activities within an environment that players can explore, but the AR contents can serve as an educational tool. The project is designed to increase user involvement by using a familiar and enjoyable game as a basis and adding an educational dimension by incorporating AR technology and engaging and interactive multimedia to provide users with facts about the objects that they have located

  11. A numerical model of aerosol scavenging

    International Nuclear Information System (INIS)

    Bradley, M.M.; Molenkamp, C.R.

    1991-10-01

    Using a three-dimensional numerical cloud/smoke-plume model, we have simulated the burning of a large, mid-latitude city following a nuclear exchange. The model includes 18 dynamic and microphysical equations that predict the fire-driven airflow, cloud processes, and smoke-cloud interactions. In the simulation, the intense heating from the burning city produces a firestorm with updraft velocities exceeding 60 m/s. Within 15 minutes of ignition, the smoke plume penetrates the tropopause. The updraft triggers a cumulonimbus cloud that produces significant quantities of ice, snow, and hail. These solid hydrometeors, as well as cloud droplets and rain, interact with the smoke particles from the fire. At the end of the one-hour simulation, over 20% of the smoke is in slowly falling snowflakes. If the snow reaches the ground before the flakes completely sublimate (or melt and then evaporate), then only approximately 50% of the smoke will survive the scavenging processes and remain in the atmosphere to affect the global climate

  12. Computational studies of free radical-scavenging properties of phenolic compounds.

    Science.gov (United States)

    Alov, Petko; Tsakovska, Ivanka; Pajeva, Ilza

    2015-01-01

    For more than half a century free radical-induced alterations at cellular and organ levels have been investigated as a probable underlying mechanism of a number of adverse health conditions. Consequently, significant research efforts have been spent for discovering more effective and potent antioxidants / free radical scavengers for treatment of these adverse conditions. Being by far the most used antioxidants among natural and synthetic compounds, mono- and polyphenols have been the focus of both experimental and computational research on mechanisms of free radical scavenging. Quantum chemical studies have provided a significant amount of data on mechanisms of reactions between phenolic compounds and free radicals outlining a number of properties with a key role for the radical scavenging activity and capacity of phenolics. The obtained quantum chemical parameters together with other molecular descriptors have been used in quantitative structure-activity relationship (QSAR) analyses for the design of new more effective phenolic antioxidants and for identification of the most useful natural antioxidant phenolics. This review aims at presenting the state of the art in quantum chemical and QSAR studies of phenolic antioxidants and at analysing the trends observed in the field in the last decade.

  13. Increase in the free radical scavenging capability of bitter gourd by a heat-drying process.

    Science.gov (United States)

    Wei, Lu; Shaoyun, Wang; Shutao, Liu; Jianwu, Zhou; Lijing, Ke; Pingfan, Rao

    2013-12-01

    Bitter gourd (Momordica charantia Linn.) is widely regarded as one of the best remedy foods for diabetes. The positive effect of bitter gourd on diabetes has been attributed in part to the remarkable free radical scavenging activity of its boiled water extract from sun-dried fruits. It is well known that a heat process significantly influences the antioxidant activity of fresh fruits. However, the heat drying processes of bitter gourd have not been studied so far. Here, we show that the free radical scavenging capability of bitter gourd extract significantly increases after the heat drying process, while the content of flavonoids and phenols, which are generally regarded as the main antioxidant components in bitter gourd, remain unaffected. Furthermore, the content of free amino acids and the total reducing sugar were found to decrease with increasing browning index, indicating the progression of the Maillard reaction, products of which are known to possess significant antioxidant activity. Therefore, it suggests that Maillard reaction products may be the main contributors to the increase in antioxidant capability. Finally, the bitter gourd extract with the higher antioxidant activity, was shown to manifest a corresponding higher proliferation activity on NIT-1 beta-cells. These results suggest that controllable conditions in the heat-drying processing of fresh bitter gourd fruit is of significance for enhancing the total free radical scavenging capacity, beta-cell proliferation activity and possibly the anti-diabetic activity of this fruit.

  14. Gallic Acid as an Oxygen Scavenger in Bio-Based Multilayer Packaging Films.

    Science.gov (United States)

    Pant, Astrid F; Sängerlaub, Sven; Müller, Kajetan

    2017-05-03

    Oxygen scavengers are used in food packaging to protect oxygen-sensitive food products. A mixture of gallic acid (GA) and sodium carbonate was used as an oxygen scavenger (OSc) in bio-based multilayer packaging films produced in a three-step process: compounding, flat film extrusion, and lamination. We investigated the film surface color as well as oxygen absorption at different relative humidities (RHs) and temperatures, and compared the oxygen absorption of OSc powder, monolayer films, and multilayer films. The films were initially brownish-red in color but changed to greenish-black during oxygen absorption under humid conditions. We observed a maximum absorption capacity of 447 mg O₂/g GA at 21 °C and 100% RH. The incorporation of GA into a polymer matrix reduced the rate of oxygen absorption compared to the GA powder because the polymer acted as a barrier to oxygen and water vapor diffusion. As expected, the temperature had a significant effect on the initial absorption rate of the multilayer films; the corresponding activation energy was 75.4 kJ/mol. Higher RH significantly increased the oxygen absorption rate. These results demonstrate for the first time the production and the properties of a bio-based multilayer packaging film with GA as the oxygen scavenger. Potential applications include the packaging of food products with high water activity (a w > 0.86).

  15. In vitro antioxidant and free radical scavenging activity of different parts of Tabebuia pallida growing in Bangladesh.

    Science.gov (United States)

    Rahman, Md Mahbubur; Islam, Md Badrul; Biswas, Mohitosh; Khurshid Alam, A H M

    2015-10-30

    In humans, many diseases are associated with the accumulation of free radicals. Antioxidants can scavenge free radicals and minimize their impact. Therefore, the search for naturally occurring antioxidants of plant origin is imperative. Here, we aimed to investigate the antioxidant and free radical scavenging properties of methanolic extracts from Tabebuia pallida (T. pallida) stem bark (TPSB), root bark (TPRB), leaves (TPL), and flowers (TPF). The antioxidant and free radical scavenging activity were determined by several standard methods using spectrophotomer. Total phenolic and flavonoid contents were estimated using Folin-Ciocalteu reagent and aluminum chloride colorimetric assay methods, respectively. Among the extracts, TPL showed the highest total antioxidant capacity followed by TPRB, TPF, and TPSB. Based on DPPH and hydroxyl radical scavenging activity, TPL showed strong scavenging activity (91.05 ± 1.10 and 62.00 ± 0.57) with IC50 of 9.20 ± 0.28 and 46.00 ± 2.84 μg/mL, respectively when compared with standard BHT (IC50 of 7.00 ± 0.25 μg/mL) and CA (75.00 ± 0.14 μg/mL). These results suggest that TPL had the highest radical scavenging activity among the extractives that closely resembled the standard's. In lipid peroxidation inhibition assay, TPL exhibited the most potent inhibitory activity (83.18 ± 2.12 %) with IC50 of 12.00 ± 2.12 μg/mL, which closely resembled standard CA (IC50 of 10.50 ± 0.28 μg/mL). Also, the reducing capacity on ferrous ion was in the following order: TPL > TPRB > TF > TPSB. The phenolic and flavonoid contents of TPL were higher than other extractives. A positive correlation (p value free radical (DPPH(·) and (·)OH) scavenging efficiencies and lipid peroxidation inhibition activity. Methanolic extract of T. pallida leaf is a potential source of natural antioxidants and serves as an effective free radical scavenger and/or inhibitor. Hence, T. pallida might be a good plant-based pharmaceutical product for several

  16. Theoretical insights on the antioxidant activity of edaravone free radical scavengers derivatives

    Science.gov (United States)

    Cerón-Carrasco, José P.; Roy, Hélène M.; Cerezo, Javier; Jacquemin, Denis; Laurent, Adèle D.

    2014-04-01

    The prediction of antioxidant properties is not straightforward due to the complexity of the in vivo systems. Here, we use theoretical descriptors, including the potential of ionization, the electrodonating power and the spin density distribution, to characterize the antioxidant capacity of edaravone (EDV) derivatives. Our computations reveal the relationship between these parameters and their potential bioactivity as free radical scavengers. We conclude that more efficient antioxidants could be synthesized by tuning the R1 and R2 positions of the EDV structure, rather than modifying the R3 group. Such modifications might improve the antioxidant activity in neutral and deprotonated forms.

  17. The research progress of several kinds of free radical scavengers

    International Nuclear Information System (INIS)

    Qian Liren; Huang Yuecheng; Cai Jianming

    2009-01-01

    Ionization radiation can generate free radicals in biological system, which could induce lipid peroxi-dation, biomacromolecule and biomembrane damage, lost of cell function, cell cycle disturbance, genetic mutation and so on. The scavenging free radicals can protect organism from radiation damage. Many radio-protective agents, such as amylase, hydroxyl-benzene derivatives, hormone, vitamin, have great abilities to protect organism from radiation via scavenging free radicals. In this paper, we mainly review the free radical scavenging effects of several kinds of radio-protective agents. (authors)

  18. Polymorphic ROS scavenging revealed by CCCP in a lizard

    Science.gov (United States)

    Olsson, Mats; Wilson, Mark; Isaksson, Caroline; Uller, Tobias

    2009-07-01

    Ingestion of antioxidants has been argued to scavenge circulating reactive molecules (e.g., free radicals), play a part in mate choice (by mediating access to this important resource), and perhaps increase life span. However, recent work has come to question these relationships. We have shown elsewhere in the polychromatic lizard, Ctenophorus pictus, that diet supplementation of carotenoids as antioxidants does not depress circulating natural reactive oxygen species (ROS) levels and leads to no corresponding improvement of color traits. However, a much stronger test would be to experimentally manipulate the ROS levels themselves and assess carotenoid-induced ROS depression. Here, we achieve this by using carbonyl cyanide 3-chlorophenylhydrazone, which elevates superoxide (SO) formation approximately threefold at 10 μM in this model system. We then look for depressing effects on ROS of the carotenoids in order to assess whether ‘super-production’ of SO makes carotenoid effects on elevated ROS levels detectable. The rationale for this treatment was that if not even such elevated levels of SO are reduced by carotenoid supplementation, the putative link carotenoids, ROS depression, and mate quality (in terms of antioxidant capacity) is highly questionable. We conclude that there is no significant effect of carotenoids on mean SO levels even at the induced ROS levels. However, our results showed a significant interaction effect between carotenoid treatment and male color, with red males having higher ROS levels than yellow males. We suggest that this may be because different pigments are differently involved in the generation of the integumental colors in the two morphs with concomitant effects on ROS depletion depending on carotenoid uptake or allocation to coloration and antioxidation.

  19. HPLC-Analysis of Polyphenolic Compounds in Gardenia jasminoides and Determination of Antioxidant Activity by Using Free Radical Scavenging Assays

    OpenAIRE

    Riaz Uddin; Moni Rani Saha; Nusrat Subhan; Hemayet Hossain; Ismet Ara Jahan; Raushanara Akter; Ashraful Alam

    2014-01-01

    Purpose: Gardenia jasminoides is a traditional medicinal plant rich in anti-inflammatory flavonoids and phenolic compounds and used for the treatment of inflammatory diseases and pain. In this present study, antioxidant potential of Gardenia jasminoides leaves extract was evaluated by using various antioxidant assays. Methods: Various antioxidant assays such as 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, reducing power and total antioxidant capacity expressed as equival...

  20. Development of a new free radical absorption capacity assay method for antioxidants: aroxyl radical absorption capacity (ARAC).

    Science.gov (United States)

    Nagaoka, Shin-ichi; Nagai, Kanae; Fujii, Yuko; Ouchi, Aya; Mukai, Kazuo

    2013-10-23

    A new free radical absorption capacity assay method is proposed with use of an aroxyl radical (2,6-di-tert-butyl-4-(4'-methoxyphenyl)phenoxyl radical) and stopped-flow spectroscopy and is named the aroxyl radical absorption capacity (ARAC) assay method. The free radical absorption capacity (ARAC value) of each tocopherol was determined through measurement of the radical-scavenging rate constant in ethanol. The ARAC value could also be evaluated through measurement of the half-life of the aroxyl radical during the scavenging reaction. For the estimation of the free radical absorption capacity, the aroxyl radical was more suitable than the DPPH radical, galvinoxyl, and p-nitrophenyl nitronyl nitroxide. The ARAC value in tocopherols showed the same tendency as the free radical absorption capacities reported previously, and the tendency was independent of an oxygen radical participating in the scavenging reaction and of a medium surrounding the tocopherol and oxygen radical. The ARAC value can be directly connected to the free radical-scavenging rate constant, and the ARAC method has the advantage of treating a stable and isolable radical (aroxyl radical) in a user-friendly organic solvent (ethanol). The ARAC method was also successfully applied to a palm oil extract. Accordingly, the ARAC method would be useful in free radical absorption capacity assay of antioxidative reagents and foods.

  1. Free Radical Scavenging and Cellular Antioxidant Properties of Astaxanthin.

    Science.gov (United States)

    Dose, Janina; Matsugo, Seiichi; Yokokawa, Haruka; Koshida, Yutaro; Okazaki, Shigetoshi; Seidel, Ulrike; Eggersdorfer, Manfred; Rimbach, Gerald; Esatbeyoglu, Tuba

    2016-01-14

    Astaxanthin is a coloring agent which is used as a feed additive in aquaculture nutrition. Recently, potential health benefits of astaxanthin have been discussed which may be partly related to its free radical scavenging and antioxidant properties. Our electron spin resonance (ESR) and spin trapping data suggest that synthetic astaxanthin is a potent free radical scavenger in terms of diphenylpicryl-hydrazyl (DPPH) and galvinoxyl free radicals. Furthermore, astaxanthin dose-dependently quenched singlet oxygen as determined by photon counting. In addition to free radical scavenging and singlet oxygen quenching properties, astaxanthin induced the antioxidant enzyme paroxoanase-1, enhanced glutathione concentrations and prevented lipid peroxidation in cultured hepatocytes. Present results suggest that, beyond its coloring properties, synthetic astaxanthin exhibits free radical scavenging, singlet oxygen quenching, and antioxidant activities which could probably positively affect animal and human health.

  2. Performance of Chickens under Semi-scavenging Conditions: A ...

    African Journals Online (AJOL)

    Performance of Chickens under Semi-scavenging Conditions: A Case Study of ... per household was lost per year due to diseases, predators, accidents, and theft. ... as well as chicken house construction so as to avoid the risks of predators.

  3. Nitric oxide radical scavenging potential of some Elburz medicinal ...

    African Journals Online (AJOL)

    ONOS

    2010-08-09

    Aug 9, 2010 ... NO is also implicated in inflammation and other pathological ... adhesion and prevention of smooth muscle cell prolife- ... reduce NO levels is making use of NO scavengers. For ..... human nutrition and health are considerable.

  4. Antimicrobial and free radical scavenging activities of five ...

    African Journals Online (AJOL)

    Extracts from five indigenous Palestinian medicinal plants including Rosmarinus officinalis, Pisidium guajava, Punica granatum peel, grape seeds and Teucrium polium were investigated for antimicrobial and free radical scavenging activities against eight microorganisms, using well diffusion method. The microorganisms ...

  5. Shark scavenging behavior in the presence of competition

    Directory of Open Access Journals (Sweden)

    Shannon P. GERRY, Andrea J. SCOTT

    2010-02-01

    Full Text Available The distribution of organisms within a community can often be determined by the degree of plasticity or degree of specialization of resource acquisition. Resource acquisition is often based on the morphology of an organism, behavior, or a combination of both. Performance tests of feeding can identify the possible interactions that allow one species to better exploit a prey item. Scavenging behaviors in the presence or absence of a competitor were investigated by quantifying prey selection in a trophic generalist, spiny dogfish Squalus acanthias, and a trophic specialist, smooth-hounds Mustelus canis, in order to determine if each shark scavenged according to its jaw morphology. The diet of dogfish consists of small fishes, squid, ctenophores, and bivalves; they are expected to be nonselective predators. Smooth-hounds primarily feed on crustaceans; therefore, they are predicted to select crabs over other prey types. Prey selection was quantified by ranking each prey item according to the order it was consumed. Dietary shifts were analyzed by comparing the percentage of each prey item selected during solitary versus competitive scavenging. When scavenging alone, dogfish prefer herring and squid, which are easily handled by the cutting dentition of dogfish. Dogfish shift their diet to include a greater number of prey types when scavenging with a competitor. Smooth-hounds scavenge on squid, herring, and shrimp when alone, but increase the number of crabs in the diet when scavenging competitively. Competition causes smooth-hounds to scavenge according to their jaw morphology and locomotor abilities, which enables them to feed on a specialized resource [Current Zoology 56 (1: 100–108 2010].

  6. Station Capacity

    DEFF Research Database (Denmark)

    Landex, Alex

    2011-01-01

    the probability of conflicts and the minimum headway times into account. The last method analyzes how optimal platform tracks are used by examining the arrival and departure pattern of the trains. The developed methods can either be used separately to analyze specific characteristics of the capacity of a station......Stations are often limiting the capacity of railway networks. This is due to extra need of tracks when trains stand still, trains turning around, and conflicting train routes. Although stations are often the capacity bottlenecks, most capacity analysis methods focus on open line capacity. Therefore...... for platform tracks and the probability that arriving trains will not get a platform track immediately at arrival. The third method is a scalable method that analyzes the conflicts in the switch zone(s). In its simplest stage, the method just analyzes the track layout while the more advanced stages also take...

  7. Bergenin Content and Free Radical Scavenging Activity of Bergenia Extracts. .

    Science.gov (United States)

    Hendrychová, Helena; Martin, Jan; Tůmová, Lenka; Kočevar-Glavač, Nina

    2015-07-01

    Our research was focused on the evaluation of bergenin content and free radical scavenging activity of extracts prepared from three different species of Bergenia - B. crassifolia (L.) Fritsch., B. ciliata (Haw.) Sternb. and B. x ornata Stein. collected during different seasons. Using an HPLC method, the highest total amount of bergenin was revealed in the leaves of B. x ornata and B. crassifolia (4.9 - 5.1 mg x g(-1)). Free radical scavenging power was determined by two methods--FRAP and NADH. The best free radical scavengers were B. crassifolia (FRAP: 6.7 - 15.9 mg GAE. 100g(-1); NADH: 20.3 - 50.9%) and B. ornata (FRAP: 13.7 - 15.2 mg GAE. 100g(-1); NADH: 29.3 - 31.1%). The lowest content of bergenin and the weakest radical scavenger was B. ciliata (bergenin: 3.1 mg x g(-1); FRAP: 5.5 - 11.0 mg GAE.100g(-1); NADH: 23.2 - 25.6%). The presence of a large percentage of bergenin is responsible for the radical scavenging activity, as shown by the results from the FRAP and NADH assays. Significant, positive correlation was found between bergenin content and radical scavenging activity in both methods.

  8. Weight savings in aerospace vehicles through propellant scavenging

    Science.gov (United States)

    Schneider, Steven J.; Reed, Brian D.

    1988-01-01

    Vehicle payload benefits of scavenging hydrogen and oxygen propellants are addressed. The approach used is to select a vehicle and a mission and then select a scavenging system for detailed weight analysis. The Shuttle 2 vehicle on a Space Station rendezvous mission was chosen for study. The propellant scavenging system scavenges liquid hydrogen and liquid oxygen from the launch propulsion tankage during orbital maneuvers and stores them in well insulated liquid accumulators for use in a cryogenic auxiliary propulsion system. The fraction of auxiliary propulsion propellant which may be scavenged for propulsive purposes is estimated to be 45.1 percent. The auxiliary propulsion subsystem dry mass, including the proposed scavenging system, an additional 20 percent for secondary structure, an additional 5 percent for electrical service, a 10 percent weight growth margin, and 15.4 percent propellant reserves and residuals is estimated to be 6331 kg. This study shows that the fraction of the on-orbit vehicle mass required by the auxiliary propulsion system of this Shuttle 2 vehicle using this technology is estimated to be 12.0 percent compared to 19.9 percent for a vehicle with an earth-storable bipropellant system. This results in a vehicle with the capability of delivering an additional 7820 kg to the Space Station.

  9. An illicit economy: scavenging and recycling of medical waste.

    Science.gov (United States)

    Patwary, Masum A; O'Hare, William Thomas; Sarker, M H

    2011-11-01

    This paper discusses a significant illicit economy, including black and grey aspects, associated with medical waste scavenging and recycling in a megacity, considering hazards to the specific group involved in scavenging as well as hazards to the general population of city dwellers. Data were collected in Dhaka, Bangladesh, using a variety of techniques based on formal representative sampling for fixed populations (such as recycling operatives) and adaptive sampling for roaming populations (such as scavengers). Extremely hazardous items (including date expired medicines, used syringes, knives, blades and saline bags) were scavenged, repackaged and resold to the community. Some HCE employees were also observed to sell hazardous items directly to scavengers, and both employees and scavengers were observed to supply contaminated items to an informal plastics recycling industry. This trade was made possible by the absence of segregation, secure storage and proper disposal of medical waste. Corruption, a lack of accountability and individual responsibility were also found to be contributors. In most cases the individuals involved with these activities did not understand the risks. Although motivation was often for personal gain or in support of substance abuse, participants sometimes felt that they were providing a useful service to the community. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Weight savings in aerospace vehicles through propellant scavenging

    Science.gov (United States)

    Schneider, Steven J.; Reed, Brian D.

    1988-05-01

    Vehicle payload benefits of scavenging hydrogen and oxygen propellants are addressed. The approach used is to select a vehicle and a mission and then select a scavenging system for detailed weight analysis. The Shuttle 2 vehicle on a Space Station rendezvous mission was chosen for study. The propellant scavenging system scavenges liquid hydrogen and liquid oxygen from the launch propulsion tankage during orbital maneuvers and stores them in well insulated liquid accumulators for use in a cryogenic auxiliary propulsion system. The fraction of auxiliary propulsion propellant which may be scavenged for propulsive purposes is estimated to be 45.1 percent. The auxiliary propulsion subsystem dry mass, including the proposed scavenging system, an additional 20 percent for secondary structure, an additional 5 percent for electrical service, a 10 percent weight growth margin, and 15.4 percent propellant reserves and residuals is estimated to be 6331 kg. This study shows that the fraction of the on-orbit vehicle mass required by the auxiliary propulsion system of this Shuttle 2 vehicle using this technology is estimated to be 12.0 percent compared to 19.9 percent for a vehicle with an earth-storable bipropellant system. This results in a vehicle with the capability of delivering an additional 7820 kg to the Space Station.

  11. Electron scavenging in ethylene glycol-water glass at 4 and 77 K: scavenging of trapped vs mobile electrons. [. gamma. -rays, x radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lin, D P; Kevan, L [Wayne State Univ., Detroit, Mich. (USA). Dept. of Chemistry; Steen, H B

    1976-01-01

    Electron scavenging efficiencies have been measured at 77 and 4 K in ethylene glycol-water glass for the following scavengers which span a 250-fold range of scavenger efficiencies at 77 K: HCl, NaNO/sub 3/ and K/sub 2/Cr0/sub 4/. The range of scavenging efficiencies decreases to 62 at 4 K with the largest relative change occurring for the less efficient scavengers. These results are suggested to be most consistent with a model in which scavenging occurs by tunneling from shallowly and deeply trapped electrons at 4 and 77 K, respectively.

  12. Alkylperoxyl radical scavenging activity of red leaf lettuce (Lactuca sativa L.) phenolics.

    Science.gov (United States)

    Caldwell, Charles R

    2003-07-30

    Although lettuce may provide relatively low levels of antioxidative phytochemicals which may contribute to human health, lettuce leaf extracts in fact contained compounds with high specific peroxyl radical scavenging activities. After determining the extraction conditions that minimized phenolic oxidation and produced the highest oxygen radical absorbance capacity (ORAC) values, the phenolic compounds from red leaf lettuce were separated by reverse-phase high-performance liquid chromatography (HPLC). The primary phenolic compounds in the leaf tissue extracts were mono- and dicaffeoyltartaric acid (CTA and DCTA), mono- and dicaffeoylquinic acid (CQA and DCQA), quercetin 3-malonylglucoside (QMG), quercetin 3-glucoside (QG), cyanidin 3-malonylglucoside (CMG), and an unknown phenolic ester (UPE). Significant levels of DCQA were only found after wounding. Using the new fluorescein-based ORAC assay procedures, fractions from the HPLC analyses were assayed for peroxyl radical absorbance capacity. Using absorbance to estimate concentration, the decreasing order of contribution to the total ORAC value of an extract from wounded tissue was QMG > DCQA > CMG > DCTA > UPE > QG > CTA. The decreasing order of the specific peroxyl radical scavenging activities was CMG > QG > DCTA > DCQA > QMG > UPE > CQA > CTA. Since the concentrations of plant flavonoid and phenolic acid esters are sensitive to environmental factors, this information may be used to develop pre- and postharvest conditions which increase the dietary benefits of leaf lettuce.

  13. Free radical scavenging activity of ethanolic extracts from herbs and spices commercialized in Brazil

    Directory of Open Access Journals (Sweden)

    Lilian Regina Barros Mariutti

    2008-12-01

    Full Text Available Ethanolic extracts from 23 different dried herbs and spices commercialized in Brazil were investigated for their free radical scavenging properties using the stable free radicals 2,2'-diphenyl-β-picrylhydrazyl (DPPH• and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS•+, and Trolox as reference (TEAC for both radicals. The kinetic curves for both radicals showed to follow the first order kinetics model and the decay rate constant (k obs was calculated. For all the samples, the two methods showed a good linear TEAC correlation, indicating that the average reactivity of the compounds present in the ethanolic extracts was similar. Sage and rosemary extracts showed the highest free radical scavenging capacities, while onion showed negligible activity and colorifico, one of the most consumed spices in Brazil, showed low ABTS•+ scavenging activity. Three distinct situations were found for the extracts concerning the DPPH• scavenging capacities: (1 extracts, like rosemary and laurel, that presented the same efficient concentrations (EC50 but differed in the TEAC values and velocities of action (k obs, (2 extracts, such as garlic and basil, that showed similar EC50 and TEAC values, but different k obs values and (3 extracts that reacted at the same velocities but completely differed in the free radical scavenging capacities, like black pepper, savory, nutmeg, rosemary and sage. Similar considerations could be done for the ABTS•+ results. For the first time the ABTS•+ scavenging activity for allspice, basil, cardamom, chives, colorifico, cumin, dill, laurel, marjoram, parsley and tarragon was reported.Extratos etanólicos de 23 ervas e condimentos desidratados comercializados no Brasil foram analisados quanto as suas propriedades antioxidantes utilizando os radicais 2,2'-difenil-β-picrilhidrazil (DPPH• e ácido 2,2'-azino-bis(3-etilbenzotiazolina-6-sulfônico (ABTS•+, Trolox foi usado como referência para ambos radicais

  14. Synthesis and Free Radical Scavenging Activity of New Hydroxybenzylidene Hydrazines

    Directory of Open Access Journals (Sweden)

    Frantisek Sersen

    2017-05-01

    Full Text Available Hydroxybenzylidene hydrazines exhibit a wide spectrum of biological activities. Here, we report synthesis and free radical scavenging activity of nine new N-(hydroxybenzylidene-N′-[2,6-dinitro-4-(trifluoromethyl]phenylhydrazines. The chemical structures of these compounds were confirmed by 1H-NMR, 13C-NMR, 19F-NMR, IR spectroscopy, LC-MS, and elemental analysis. The prepared compounds were tested for their activity to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH, galvinoxyl radical (GOR, and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS radicals. The free radical scavenging activity expressed as SC50 values of these compounds varied in a wide range, from a strong to no radical scavenging effect. The most effective radical scavengers were hydroxybenzylidene hydrazines containing three hydroxyl groups in the benzylidene part of their molecules. The prepared compounds were also tested for their activity to inhibit photosynthetic electron transport in spinach chloroplasts. IC50 values of these compounds varied in wide range, from an intermediate to no inhibitory effect.

  15. Synthesis and Free Radical Scavenging Activity of New Hydroxybenzylidene Hydrazines.

    Science.gov (United States)

    Sersen, Frantisek; Gregan, Fridrich; Kotora, Peter; Kmetova, Jarmila; Filo, Juraj; Loos, Dusan; Gregan, Juraj

    2017-05-29

    Hydroxybenzylidene hydrazines exhibit a wide spectrum of biological activities. Here, we report synthesis and free radical scavenging activity of nine new N-(hydroxybenzylidene)-N'-[2,6-dinitro-4-(trifluoromethyl)]phenylhydrazines. The chemical structures of these compounds were confirmed by 1H-NMR, 13C-NMR, 19F-NMR, IR spectroscopy, LC-MS, and elemental analysis. The prepared compounds were tested for their activity to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH), galvinoxyl radical (GOR), and 2,2'-azino-bis(3-ethylbenzothiazoline)-6-sulphonic acid (ABTS) radicals. The free radical scavenging activity expressed as SC50 values of these compounds varied in a wide range, from a strong to no radical scavenging effect. The most effective radical scavengers were hydroxybenzylidene hydrazines containing three hydroxyl groups in the benzylidene part of their molecules. The prepared compounds were also tested for their activity to inhibit photosynthetic electron transport in spinach chloroplasts. IC50 values of these compounds varied in wide range, from an intermediate to no inhibitory effect.

  16. Carrying Capacity

    DEFF Research Database (Denmark)

    Schroll, Henning; Andersen, Jan; Kjærgård, Bente

    2012-01-01

    A spatial planning act was introduced inIndonesia 1992 and renewed in 2008. It emphasised the planning role of decentralised authorities. The spatial planning act covers both spatial and environmental issues. It defines the concept of carrying capacity and includes definitions of supportive....../cities. Four different sectors (water, food production, waste, and forests) were selected as core areas for decentralised spatial planning. Indicators for SCC and ACC were identified and assessed with regard to relevance and quantifiability. For each of the indicators selected, a legal threshold or guiding...... was introduced inIndonesia 1992 and renewed in 2008. It emphasised the planning role of decentralised authorities. The spatial planning act covers both spatial and environmental issues. It defines the concept of carrying capacity and includes definitions of supportive carrying capacity (SCC) and assimilative...

  17. The Evolution of the Scavenger Receptor Cysteine-Rich Domain of the Class A Scavenger Receptors

    Directory of Open Access Journals (Sweden)

    Nicholas eYap

    2015-07-01

    Full Text Available The class A Scavenger Receptor (cA-SR family is a group of five evolutionarily related innate immune receptors. The cA-SRs are known for their promiscuous ligand binding; as they have been shown to bind bacteria such as Streptococcus pneumoniae, and Escherichia coli, as well as different modified forms of low-density lipoprotein. Three of the five family members possess a Scavenger Receptor Cysteine Rich (SRCR domain while the remaining two receptors lack the domain. Previous work has suggested that the Macrophage Associated Receptor with COllagenous structure (MARCO shares a recent common ancestor with the non-SRCR-containing receptors; however the origin of the SRCR domain within the cA-SRs remains unknown. We hypothesize that the SRCR domains of the cA-SRs have a common origin that predates teleost fish. Using the newly available sequence data from sea lamprey and ghost shark genome projects, we have shown that MARCO shares a common ancestor with the SRCR-containing proteins. In addition, we explored the evolutionary relationships within the SRCR domain by reconstructing the ancestral SRCR domains of the cA-SRs. We identified a motif that is highly conserved between the cA-SR SRCR domains and the ancestral SRCR domain that consist of WGTVCDD. We also show that the GRAEVYY motif, a functionally important motif within MARCO, is poorly conserved in the other cA-SRs and in the reconstructed ancestral domain. Further, we identified three sites within MARCO’s SRCR domain which are under positive selection. Two of these sites lie adjacent to the conserved WGTVCDD motif, and may indicate a potential biological function for these sites. Together these findings indicate a common origin of the SRCR domain within the cA-SRs; however different selective pressures between the proteins may have caused MARCOs SRCR domain to evolve to contain different functional motifs when compared to the other SRCR-containing cA-SRs.

  18. Scavenging energy from human motion with tubular dielectric polymer

    Science.gov (United States)

    Jean-Mistral, Claire; Basrour, Skandar

    2010-04-01

    Scavenging energy from human motion is a challenge to supply low consumption systems for sport or medical applications. A promising solution is to use electroactive polymers and especially dielectric polymers to scavenge mechanical energy during walk. In this paper, we present a tubular dielectric generator which is the first step toward an integration of these structures into textiles. For a 10cm length and under a strain of 100%, the structure is able to scavenge 1.5μJ for a poling voltage of 200V and up to 40μJ for a poling voltage of 1000V. A 30cm length structure is finally compared to our previous planar structure, and the power management module for those structures is discussed.

  19. Free radical scavenging properties of some wine probes

    International Nuclear Information System (INIS)

    Stasko, A.; Liptakova, M.; Malik, F.

    1999-01-01

    There are preliminary results of investigation of scavenging properties of 8 probes of Slovak wines (consisting of one reference, 3 probes of white wine and 4 probes of red wine). According to the literature so far, wine probes contain paramagnetic species (Mn 2+ , characterised with sextet spectrum, and a singlet line around g=2,00). In our probes we observed Mn 2+ signals, but no significant evidence for a single line of free radical was found. We can conclude that Mn 2+ content in the red wines is generally higher than in the white ones. Further, we investigated the scavenging activities of the probes adding solution of dinitropicryl hydrazyl (DPPH-stable radical) to them. Their ability to terminate free radicals resulted in the decrease of the final DPPH concentrations in the probes. The red wines have significantly higher capability to scavenge free radicals than the probes of white wines. (authors)

  20. Antiradical capacity and reducing power of different extraction ...

    African Journals Online (AJOL)

    Areca catechu is a common traditional Chinese medicinal plant used to treat dyspepsia, constipation, beriberi and oedema. The antiradical capacities of different extraction method of A. catechu extracts were evaluated by scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide radicals. Reducing power ...

  1. Electron beam treatment with radical scavengers/enhancers

    International Nuclear Information System (INIS)

    Gehringer, P.

    1994-08-01

    E-beam treatment of low level contaminated groundwater is best apt to demonstrate the role of scavengers and enhancers, respectively because groundwater already contains some scavengers as natural solutes. The action of ionizing radiation to water is known to result in the formation of ions, molecular and free radical species. For low level contaminations of groundwater (pollutant concentration aqu - and H are of interest for pollutant decomposition. The pollutants have to compete for the free radical species with the natural solutes. 10 figures are discussed. (author)

  2. Free radical scavenging injectable hydrogels for regenerative therapy

    International Nuclear Information System (INIS)

    Komeri, Remya; Thankam, Finosh Gnanaprakasam; Muthu, Jayabalan

    2017-01-01

    Pathological free radicals generated from inflamed and infarcted cardiac tissues interferes natural tissue repair mechanisms. Hypoxic microenvironment at the injured zone of non-regenerating cardiac tissues hinders the therapeutic attempts including cell therapy. Here we report an injectable, cytocompatible, free radical scavenging synthetic hydrogel formulation for regenerative therapy. New hydrogel (PEAX-P) is prepared with D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer (PEAX) and PEGDiacrylate. PEAX-P hydrogel swells 4.9 times the initial weight and retains 100.07 kPa Young modulus at equilibrium swelling, which is suitable for cardiac applications. PEAX-P hydrogel retains elastic nature even at 60% compressive strain, which is favorable to fit with the dynamic and elastic natural tissue counterparts. PEAX-P hydrogel scavenges 51% DPPH radical, 40% hydroxyl radicals 41% nitrate radicals with 31% reducing power. The presence of hydrogel protects 62% cardiomyoblast cells treated with stress inducing media at LD 50 concentration. The free hydroxyl groups in sugar alcohols of the comacromer influence the free radical scavenging. Comparatively, PEAX-P hydrogel based on xylitol evinces slightly lower scavenging characteristics than with previously reported PEAM-P hydrogel containing mannitol having more hydroxyl groups. The possible free radical scavenging mechanism of the present hydrogel relies on the free π electrons associated with uncrosslinked fumarate bonds, hydrogen atoms associated with sugar alcohols/PEG and radical dilution by free water in the matrix. Briefly, the present PEAX-P hydrogel is a potential injectable system for combined antioxidant and regenerative therapy. - Graphical abstract: Injectable hydrogel with inherent free radical scavenging property for regenerative tissue engineering application. - Highlights: • Novel injectable hydrogel (PEAX-P) is prepared using D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer

  3. Free radical scavenging injectable hydrogels for regenerative therapy

    Energy Technology Data Exchange (ETDEWEB)

    Komeri, Remya [Sree Chitra Tirunal Institute for Medical Sciences and Technology, Polymer Science Division, BMT Wing, Thiruvananthapuram 695 012, Kerala State (India); Thankam, Finosh Gnanaprakasam [Dept. of Biomedical Sciences, Creighton University, 2500 California Plaza, Omaha NE68178 (United States); Muthu, Jayabalan, E-mail: mjayabalan52@gmail.com [Sree Chitra Tirunal Institute for Medical Sciences and Technology, Polymer Science Division, BMT Wing, Thiruvananthapuram 695 012, Kerala State (India)

    2017-02-01

    Pathological free radicals generated from inflamed and infarcted cardiac tissues interferes natural tissue repair mechanisms. Hypoxic microenvironment at the injured zone of non-regenerating cardiac tissues hinders the therapeutic attempts including cell therapy. Here we report an injectable, cytocompatible, free radical scavenging synthetic hydrogel formulation for regenerative therapy. New hydrogel (PEAX-P) is prepared with D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer (PEAX) and PEGDiacrylate. PEAX-P hydrogel swells 4.9 times the initial weight and retains 100.07 kPa Young modulus at equilibrium swelling, which is suitable for cardiac applications. PEAX-P hydrogel retains elastic nature even at 60% compressive strain, which is favorable to fit with the dynamic and elastic natural tissue counterparts. PEAX-P hydrogel scavenges 51% DPPH radical, 40% hydroxyl radicals 41% nitrate radicals with 31% reducing power. The presence of hydrogel protects 62% cardiomyoblast cells treated with stress inducing media at LD 50 concentration. The free hydroxyl groups in sugar alcohols of the comacromer influence the free radical scavenging. Comparatively, PEAX-P hydrogel based on xylitol evinces slightly lower scavenging characteristics than with previously reported PEAM-P hydrogel containing mannitol having more hydroxyl groups. The possible free radical scavenging mechanism of the present hydrogel relies on the free π electrons associated with uncrosslinked fumarate bonds, hydrogen atoms associated with sugar alcohols/PEG and radical dilution by free water in the matrix. Briefly, the present PEAX-P hydrogel is a potential injectable system for combined antioxidant and regenerative therapy. - Graphical abstract: Injectable hydrogel with inherent free radical scavenging property for regenerative tissue engineering application. - Highlights: • Novel injectable hydrogel (PEAX-P) is prepared using D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer

  4. Free radical-scavenging delta-lactones from Boletus calopus.

    Science.gov (United States)

    Kim, Jin-Woo; Yoo, Ick-Dong; Kim, Won-Gon

    2006-12-01

    The methanol extracts from the fruiting body of the mushroom Boletus calopus showed free radical-scavenging activity. Bioactivity-guided fractionation of the methanol extracts led to a new hydroxylated calopin named calopin B, along with the known delta-lactones calopin and cyclocalopin A. The structure of the new calopin analogue was elucidated by spectroscopic methods. All compounds showed potent free radical-scavenging activity against superoxide, DPPH, and ABTS radicals with IC (50) values of 1.2 - 5.4 microg/mL.

  5. Process for scavenging hydrogen sulfide from hydrocarbon gases

    International Nuclear Information System (INIS)

    Fox, I.

    1981-01-01

    A process for scavenging hydrogen sulfide from hydrocarbon gases utilizes iron oxide particles of unique chemical and physical properties. These particles have large surface area, and are comprised substantially of amorphous Fe 2 O 3 containing a crystalline phase of Fe 2 O 3 , Fe 3 O 4 and combinations thereof. In scavenging hydrogen sulfide, the iron oxide particles are suspended in a liquid which enters into intimate mixing contact with hydrocarbon gases; the hydrogen sulfide is reacted at an exceptional rate and only acid-stable reaction products are formed. Thereafter, the sweetened hydrocarbon gases are collected

  6. Performance of zeolite scavenge column in Xe monitoring system

    International Nuclear Information System (INIS)

    Wang Qian; Wang Hongxia; Li Wei; Bian Zhishang

    2010-01-01

    In order to improve the performance of zeolite scavenge column, its ability of removal of humidity and carbon dioxide was studied by both static and dynamic approaches. The experimental results show that various factors, including the column length and diameter, the mass of zeolite, the content of water in air, the temperature rise during adsorption, and the activation effectiveness all effect the performance of zeolite column in scavenging humanity and carbon dioxide. Based on these results and previous experience, an optimized design of the zeolite column is made for use in xenon monitoring system. (authors)

  7. Free radical scavenging activity of Eagle tea and their flavonoids

    Directory of Open Access Journals (Sweden)

    Qiong Meng

    2012-06-01

    Full Text Available In this study, an online HPLC-DAD-MS coupled with 2,2′-azinobis (3-ethylbenzthiazoline-6-sulfonic acid diammonium salt (ABTS assay was employed for evaluating free radical scavenging activity of Eagle tea and their active components. Twenty-three chromatographic peaks were detected, and nineteen components had free radical scavenging activity. Among them, eight compounds were identified as flavonoids (hyperin, isoquercitrin, quercitrin, quercetin, kaempferol, catechins, chlorogenic acid and epicatechin based on MS data and standard chromatographic characters.

  8. Applicability of an improved Trolox equivalent antioxidant capacity (TEAC) assay for evaluation of antioxidant capacity measurements of mixtures

    NARCIS (Netherlands)

    Berg, R. van den; Haenen, G.R.M.M.; Berg, H. van den; Bast, A.

    1999-01-01

    The TEAC (Trolox equivalent antioxidant capacity) assay is based on scavenging of 2,2'-azinobis-(3- ethylbenzothiazoline-6-sulfonate) radical anions (ABTS(.-)). In this report we describe a modification based on pre-generation of the ABTS radical anions with a thermolabile azo compound, 2,2'-azobis-

  9. Graphene oxide as efficient high-concentration formaldehyde scavenger and reutilization in supercapacitor.

    Science.gov (United States)

    Liang, Hongyu; Bu, Yongfeng; Zhang, Yutian; Zhang, Junyan

    2015-04-15

    Graphene oxide (GO) was investigated as a low-cost and high-efficient scavenger for high-concentration formaldehyde in alkali media. It showed very high removal capacity, 411 mg of formaldehyde per milligram of GO, and strong resistant to temperature changes. Additionally, the used GO can be easily renewed by a simple electrochemical method. By analyzing the componential and electrochemical characterizations of GO before and after use, the results showed that the degradation mechanism of formaldehyde is a collaborative process of chemical oxidation and physical adsorption, and the former dominates the degradation process. With the aid of oxygen-containing groups in GO, most formaldehyde can be easily oxidized by GO in alkaline media (this is equivalent to GO was reduced by formaldehyde). On the other hand, the used GO (reduced GO, noted as rGO) exhibits more ideal electronic double-layer capacitor (EDLC) feature than GO, along with higher rate capacitance (up to 136 F g(-1) at 50 A g(-1)). In short, GO is not only an efficient formaldehyde scavenger, but the used GO (rGO) can serve as promising electrical energy storage material. This study provides new insights for us to reutilize the discarded adsorbents generated from the environmental protection. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. A comment on "Novel scavenger removal trials increase wind turbine-caused avian fatality estimates"

    Science.gov (United States)

    Huso, Manuela M.P.; Erickson, Wallace P.

    2013-01-01

    In a recent paper, Smallwood et al. (2010) conducted a study to compare their “novel” approach to conducting carcass removal trials with what they term the “conventional” approach and to evaluate the effects of the different methods on estimated avian fatality at a wind power facility in California. A quick glance at Table 3 that succinctly summarizes their results and provides estimated fatality rates and 80% confidence intervals calculated using the 2 methods reveals a surprising result. The confidence intervals of all of their estimates and most of the conventional estimates extend below 0. These results imply that wind turbines may have the capacity to create live birds. But a more likely interpretation is that a serious error occurred in the calculation of either the average fatality rate or its standard error or both. Further evaluation of their methods reveals that the scientific basis for concluding that “many estimates of scavenger removal rates prior to [their] study were likely biased low due to scavenger swamping” and “previously reported estimates of avian fatality rates … should be adjusted upwards” was not evident in their analysis and results. Their comparison to conventional approaches was not applicable, their statistical models were questionable, and the conclusions they drew were unsupported.

  11. Enzyme inhibitory and radical scavenging effects of some antidiabetic plants of Turkey

    Science.gov (United States)

    Orhan, Nilüfer; Hoçbaç, Sanem; Orhan, Didem Deliorman; Asian, Mustafa; Ergun, Fatma

    2014-01-01

    Objective(s): Ethnopharmacological field surveys demonstrated that many plants, such as Gentiana olivieri, Helichrysum graveolens, Helichrysum plicatum ssp. plicatum, Juniperus oxycedrus ssp. oxycedrus, Juniperus communis var. saxatilis, Viscum album (ssp. album, ssp. austriacum), are used as traditional medicine for diabetes in different regions of Anatolia. The present study was designed to evaluate the in vitro antidiabetic effects of some selected plants, tested in animal models recently. Materials and Methods: α-glucosidase and α-amylase enzyme inhibitory effects of the plant extracts were investigated and Acarbose was used as a reference drug. Additionally, radical scavenging capacities were determined using 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) ABTS radical cation scavenging assay and total phenolic content of the extracts were evaluated using Folin Ciocalteu method. Results: H. graveolens ethanol extract exhibited the highest inhibitory activity (55.7 % ± 2.2) on α-amylase enzyme. Additionally, J. oxycedrus hydro-alcoholic leaf extract had potent α-amylase inhibitory effect, while the hydro-alcoholic extract of J. communis fruit showed the highest α-glucosidase inhibitory activity (IC50: 4.4 μg/ml). Conclusion: Results indicated that, antidiabetic effect of hydro-alcoholic extracts of H. graveolens capitulums, J. communis fruit and J. oxycedrus leaf might arise from inhibition of digestive enzymes. PMID:25140204

  12. Phytochemical composition and radical scavenging activities of watermelon (Citrullus lanatus seed constituents

    Directory of Open Access Journals (Sweden)

    O. L. Otutu

    2016-01-01

    Full Text Available It is a known fact that antioxidant phytochemicals in foods have many health benefits including prevention of various diseases associated with oxidative stress such as cancer, cardiovascular disease, neuro-degeneration and diabetes. Watermelon seed constituents (whole meal, shelled and shells flours were evaluated for phytochemical components and in vitro antioxidant activity to determine the potential practical applications in food and other related areas. Antioxidant activity was investigated by measuring its DPPH (2,2-diphenyl-2-picryl hydrazyl and ABTS (2, 2’-azinobis-3-ethylbenzothiozoline- 6-sulphonic acid radical scavenging ability as well as FRAP method (ferric reducing power. Quantitative estimation of the constituents showed cardiac glycosides (9.94-14.35 mg/g and saponins (11.62-32.48 mg/g as the most concentrated phytochemicals in the constituents, while alkaloids (47.2-95.8 mg/g, total phenol (5.63-8.40 mg GAE/g, flavonoids 3.51-7.76 mg QE/g. A positive radical scavenging ability of the constituents against ABTS and DPPH free radicals ranged from 0.02 to 0.04 mg Trolox equivalent /g seed flour and 39.89 to 61.11 mg ascorbic acid equivalent /g seed flour respectively. There was a considerable ferric reducing power and higher activity was observed in whole meal than shelled seeds and shells. The significant antioxidant capacities of the seed constituents underline the potential source of natural antioxidants and bioactive compounds for therapeutic purposes.

  13. Enzyme inhibitory and radical scavenging effects of some antidiabetic plants of Turkey

    Directory of Open Access Journals (Sweden)

    Nilüfer Orhan

    2014-06-01

    Full Text Available Objective(s:Ethnopharmacological field surveys demonstrated that many plants, such as Gentiana olivieri, Helichrysum graveolens, Helichrysum plicatum ssp. plicatum, Juniperus oxycedrus ssp. oxycedrus, Juniperus  communis var. saxatilis, Viscum album (ssp. album, ssp. austriacum, are used as traditional medicine for diabetes in different regions of Anatolia. The present study was designed to evaluate the in vitro antidiabetic effects of some selected plants, tested in animal models recently. Materials and Methods: α-glucosidase and α-amylase enzyme inhibitory effects of the plant extracts were investigated and Acarbose was used as a reference drug. Additionally, radical scavenging capacities were determined using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid ABTS radical cation scavenging assay and total phenolic content of the extracts were evaluated using Folin Ciocalteu method. Results: H. graveolens ethanol extract exhibited the highest inhibitory activity (55.7 % ± 2.2 on α-amylase enzyme. Additionally, J. oxycedrus hydro-alcoholic leaf extract had potent α-amylase inhibitory effect, while the hydro-alcoholic extract of J. communis fruit showed the highest α-glucosidase inhibitory activity (IC50: 4.4 μg/ml. Conclusion:Results indicated that, antidiabetic effect of hydro-alcoholic extracts of H. graveolens capitulums, J. communis fruit and J. oxycedrus leaf might arise from inhibition of digestive enzymes.

  14. Exerting Capacity.

    Science.gov (United States)

    Leger, J Michael; Phillips, Carolyn A

    2017-05-01

    Patient safety has been at the forefront of nursing research since the release of the Institute of Medicine's report estimating the number of preventable adverse events in hospital settings; yet no research to date has incorporated the perspectives of bedside nurses using classical grounded theory (CGT) methodology. This CGT study explored the perceptions of bedside registered nurses regarding patient safety in adult acute care hospitals. Data analysis used three techniques unique to CGT-the constant comparative method, coding, and memoing-to explore the values, realities, and beliefs of bedside nurses about patient safety. The analysis resulted in a substantive theory, Exerting Capacity, which explained how bedside nurses balance the demands of keeping their patients safe. Exerting Capacity has implications for health care organization leaders, nursing leaders, and bedside nurses; it also has indications for future research into the concept of patient safety.

  15. Evaluation of Antioxidant and Free Radical Scavenging Abilities of ...

    African Journals Online (AJOL)

    Objective: This study was aimed at determining the antioxidants and free radical scavenging abilities of some packaged fruit juices (PFJ) widely used as source of fluids in Nigeria. Materials and methods: Packaged fruit juice samples produced by The Coca cola Company and Chi company namely: Apple(AP), blackcurrant, ...

  16. Scavenger and antioxidant properties of prenylflavones isolated from Artocarpus heterophyllus.

    Science.gov (United States)

    Ko, F N; Cheng, Z J; Lin, C N; Teng, C M

    1998-07-15

    The antioxidant properties of prenylflavones, isolated from Artocarpus heterophyllus Lam., was evaluated in this study. Among them, artocarpine, artocarpetin, artocarpetin A, and cycloheterophyllin diacetate and peracetate had no effect on iron-induced lipid peroxidation in rat brain homogenate. They also did not scavenge the stable free radical 1,1-diphenyl-2-picrylhydrazyl. In contrast, cycloheterophyllin and artonins A and B inhibited iron-induced lipid peroxidation in rat brain homogenate and scavenged 1,1-diphenyl-2-picrylhydrazyl. They also scavenged peroxyl radicals and hydroxyl radicals that were generated by 2,2'-azobis(2-amidinopropane) dihydrochloride and the Fe3+-ascorbate-EDTA-H2O2 system, respectively. However, they did not inhibit xanthine oxidase activity or scavenge superoxide anion, hydrogen peroxide, carbon radical, or peroxyl radicals derived from 2,2'-azobis(2,4-dimethylvaleronitrile) in hexane. Moreover, cycloheterophyllin and artonins A and B inhibited copper-catalyzed oxidation of human low-density lipoprotein, as measured by fluorescence intensity, thiobarbituric acid-reactive substance and conjugated-diene formations and electrophoretic mobility. It is concluded that cycloheterophyllin and artonins A and B serve as powerful antioxidants against lipid peroxidation when biomembranes are exposed to oxygen radicals.

  17. Energy scavenging strain absorber: application to kinetic dielectric elastomer generator

    Science.gov (United States)

    Jean-Mistral, C.; Beaune, M.; Vu-Cong, T.; Sylvestre, A.

    2014-03-01

    Dielectric elastomer generators (DEGs) are light, compliant, silent energy scavengers. They can easily be incorporated into clothing where they could scavenge energy from the human kinetic movements for biomedical applications. Nevertheless, scavengers based on dielectric elastomers are soft electrostatic generators requiring a high voltage source to polarize them and high external strain, which constitutes the two major disadvantages of these transducers. We propose here a complete structure made up of a strain absorber, a DEG and a simple electronic power circuit. This new structure looks like a patch, can be attached on human's wear and located on the chest, knee, elbow… Our original strain absorber, inspired from a sailing boat winch, is able to heighten the external available strain with a minimal factor of 2. The DEG is made of silicone Danfoss Polypower and it has a total area of 6cm per 2.5cm sustaining a maximal strain of 50% at 1Hz. A complete electromechanical analytical model was developed for the DEG associated to this strain absorber. With a poling voltage of 800V, a scavenged energy of 0.57mJ per cycle is achieved with our complete structure. The performance of the DEG can further be improved by enhancing the imposed strain, by designing a stack structure, by using a dielectric elastomer with high dielectric permittivity.

  18. Is the scavenger receptor MARCO a new immune checkpoint?

    Science.gov (United States)

    Arredouani, Mohamed S

    2014-11-01

    Whereas macrophages use the scavenger receptor MARCO primarily in antimicrobial immunity by interacting with both exogenous and endogenous environments, in dendritic cells (DCs) MARCO is believed to pleiotropically link innate to adaptive immunity. MARCO exerts a significant modulatory effect on TLR-induced DC activation, thus offering novel avenues in cancer immunotherapy.

  19. Scavenging rate ecoassay: a potential indicator of estuary condition.

    Science.gov (United States)

    Porter, Augustine G; Scanes, Peter R

    2015-01-01

    Monitoring of estuary condition is essential due to the highly productive and often intensely impacted nature of these ecosystems. Assessment of the physico-chemical condition of estuaries is expensive and difficult due to naturally fluctuating water quality and biota. Assessing the vigour of ecosystem processes is an alternative method with potential to overcome much of the variability associated with physico-chemical measures. Indicators of estuary condition should have small spatial and temporal variability, have a predictable response to perturbation and be ecologically relevant. Here, we present tests of the first criterion, the spatio-temporal variability of a potential ecoassay measuring the rate of scavenging in estuaries. We hypothesised that the proposed scavenging ecoassay would not vary significantly among A) sites in an estuary, B) trips separated by weeks, or C) days in a trip. Because not all habitats are present in all estuaries, this test was undertaken in two habitats. When conducted over bare substrate there were occasional significant differences, but no discernible patterns, within levels of the experiment. When conducted over vegetated substrate, days within a trip did not vary significantly, but later trips experienced greater scavenging. This scavenging ecoassay shows potential as a tool for assessing the condition of estuarine ecosystems, and further exploration of this protocol is warranted by implementation in estuaries across a gradient of anthropogenic stress.

  20. Free radical scavenging activity and phenolic contents of ...

    African Journals Online (AJOL)

    Anthocleista djalonensis extract is widely used in Nigerian folk medicine to treat conditions whose pathogenesis implicate oxidative stress, such as diabetes and hepatitis. However, little is known of the mechanism underlying these activities. In this study, the free radical scavenging potential of a methanol extract of A.

  1. 21 CFR 868.5430 - Gas-scavenging apparatus.

    Science.gov (United States)

    2010-04-01

    ...) Identification. A gas-scavenging apparatus is a device intended to collect excess anesthetic, analgesic, or trace gases or vapors from a patient's breathing system, ventilator, or extracorporeal pump-oxygenator, and to conduct these gases out of the area by means of an exhaust system. (b) Classification. Class II...

  2. Reward Your Students with an Online Scavenger Hunt!

    Science.gov (United States)

    Board, Keith

    2013-01-01

    Do you have a class of students who do excellent work and whom you would like to give an enjoyable reward? Try an "Internet scavenger hunt" for a fun and educational change of pace! This article shares how to run the activity.

  3. Scavenger receptor AI/II truncation, lung function and COPD

    DEFF Research Database (Denmark)

    Thomsen, M; Nordestgaard, B G; Tybjaerg-Hansen, A

    2011-01-01

    The scavenger receptor A-I/II (SRA-I/II) on alveolar macrophages is involved in recognition and clearance of modified lipids and inhaled particulates. A rare variant of the SRA-I/II gene, Arg293X, truncates the distal collagen-like domain, which is essential for ligand recognition. We tested whet...

  4. Contrasting Boundary Scavenging in two Eastern Boundary Current Regimes

    Science.gov (United States)

    Anderson, R. F.; Fleisher, M. Q.; Pavia, F. J.; Vivancos, S. M.; Lu, Y.; Zhang, P.; Cheng, H.; Edwards, R. L.

    2016-02-01

    We use data from two US GEOTRACES expeditions to compare boundary scavenging intensity in two eastern boundary current systems: the Canary Current off Mauritania and the Humboldt Current off Peru. Boundary scavenging refers to the enhanced removal of trace elements from the ocean by sorption to sinking particles in regions of greater than average particle abundance. Both regimes experience high rates of biological productivity and generation of biogenic particles, with rates of productivity potentially a little greater off Peru, whereas dust fluxes are an order of magnitude greater off NW Africa (see presentation by Vivancos et al., this meeting). Despite greater productivity off Peru, we find greater intensity of scavenging off NW Africa as measured by the residence time of dissolved 230Th integrated from the surface to a depth of 2500 m (10-11 years off NW Africa vs. 15-17 years off Peru). Dissolved 231Pa/230Th ratios off NW Africa (Hayes et al., Deep Sea Res.-II 116 (2015) 29-41) are nearly twice the values observed off Peru. We attribute this difference to the well-known tendency for lithogenic phases (dust) to strongly fractionate in favor of Th uptake during scavenging and removal, leaving the dissolved phase enriched in Pa. This behavior needs to be considered when interpreting sedimentary 231Pa/230Th ratios as a paleo proxy.

  5. Clustered DNA damage on subcellular level: effect of scavengers

    Czech Academy of Sciences Publication Activity Database

    Pachnerová Brabcová, Kateřina; Sihver, L.; Yasuda, N.; Matuo, Y.; Štěpán, Václav; Davídková, Marie

    2014-01-01

    Roč. 53, č. 4 (2014), s. 705-712 ISSN 0301-634X R&D Projects: GA MŠk LD12008 Institutional support: RVO:61389005 Keywords : clustered damage * indirect effects * haevy ion * plasmid in liquid water * scavenger Subject RIV: BO - Biophysics Impact factor: 1.528, year: 2014

  6. Hydroxyl radical scavenging activity of peptide from sea cucumber ...

    African Journals Online (AJOL)

    enzyme complex, sea cucumber protein hydrolysis was carried out to obtain hydrolysates that have hydroxyl-radical-scavenging activity (HRSA). The hydrolytic process was monitored by HRSA and conditions for this process were optimized as follows: pH 6.5, temperature 35°C, 12 mg enzyme complex in a reaction solution ...

  7. Free Radical Scavenging Activity of Scoparia dulcis Extract.

    Science.gov (United States)

    Babincová, M.; Sourivong, P.

    2001-01-01

    We studied the scavenging capabilities of an extract of Scoparia dulcis (a cosmopolitan weed widespread in Laos and Vietnam) for 1-diphenyl-2-picrylhydrazyl and measured hemoglobin-catalyzed linoleic acid peroxidation with an oxygen electrode. Our results demonstrated strong antioxidant activity corresponding to mitigation of the generation of hydroxyl radicals, a possible rationale for the observed therapeutic effects of this weed.

  8. Scavenger Receptor BI Plays a Role in Facilitating Chylomicron Metabolism

    NARCIS (Netherlands)

    Out, R.; Kruijt, J.K.; Rensen, P.C.N.; Hildebrand, R.B.; Vos, P. de; Eck, M. van; Berkel, T.J.C. van

    2004-01-01

    The function of scavenger receptor class B type I (SR-BI) in mediating the selective uptake of high density lipoprotein (HDL) cholesterol esters is well established. However, the potential role of SR-BI in chylomicron and chylomicron remnant metabolism is largely unknown. In the present

  9. Genetic Variant of the Scavenger Receptor BI in Humans

    NARCIS (Netherlands)

    Vergeer, Menno; Korporaal, Suzanne J. A.; Franssen, Remco; Meurs, Illiana; Out, Ruud; Hovingh, G. Kees; Hoekstra, Menno; Sierts, Jeroen A.; Dallinga-Thie, Geesje M.; Motazacker, Mohammad Mahdi; Holleboom, Adriaan G.; van Berkel, Theo J. C.; Kastelein, John J. P.; van Eck, Miranda; Kuivenhoven, Jan Albert

    2011-01-01

    BACKGROUND In mice, the scavenger receptor class B type I (SR-BI) is essential for the delivery of high-density lipoprotein (HDL) cholesterol to the liver and steroidogenic organs. Paradoxically, elevated HDL cholesterol levels are associated with increased atherosclerosis in SR-BI-knockout mice. It

  10. Genetic variant of the scavenger receptor BI in humans

    NARCIS (Netherlands)

    Vergeer, Menno; Korporaal, Suzanne J A; Franssen, Remco; Meurs, Illiana; Out, Ruud; Hovingh, G Kees; Hoekstra, Menno; Sierts, Jeroen A; Dallinga-Thie, Geesje M; Motazacker, Mohammad Mahdi; Holleboom, Adriaan G; Van Berkel, Theo J C; Kastelein, John J P; Van Eck, Miranda; Kuivenhoven, Jan Albert

    2011-01-01

    BACKGROUND: In mice, the scavenger receptor class B type I (SR-BI) is essential for the delivery of high-density lipoprotein (HDL) cholesterol to the liver and steroidogenic organs. Paradoxically, elevated HDL cholesterol levels are associated with increased atherosclerosis in SR-BI-knockout mice.

  11. Antioxidant and free radical scavenging activities of plant extracts ...

    African Journals Online (AJOL)

    Twenty-two species of medicinal plants collected in the Mexican state of Morelos were selected to evaluate their free radical scavenging and antioxidant activities. The extracts from the aerial parts of the plants were obtained using hexane, acetone and methanol (66 extracts). The initial qualitative screening of antioxidants ...

  12. Mitochondrial respiration scavenges extramitochondrial superoxide anion via a nonenzymatic mechanism.

    OpenAIRE

    Guidot, D M; Repine, J E; Kitlowski, A D; Flores, S C; Nelson, S K; Wright, R M; McCord, J M

    1995-01-01

    We determined that mitochondrial respiration reduced cytosolic oxidant stress in vivo and scavenged extramitochondrial superoxide anion (O2-.) in vitro. First, Saccharomyces cerevisiae deficient in both the cytosolic antioxidant cupro-zinc superoxide dismutase (Cu,Zn-SOD) and electron transport (Rho0 state) grew poorly (P 0.05) in all yeast. Seco...

  13. Free radical scavenging and cytotoxic activity of five commercial ...

    African Journals Online (AJOL)

    Polygonum cuspidatum), and pomegranate (Punica granatum). It shows radical scavenging activity in the following order, according to their median effective concentration (EC

  14. Using Scavenger Hunts to Familiarize Students with Scientific Journal Articles.

    Science.gov (United States)

    Lijek, Rebeccah S; Fankhauser, Sarah C

    2016-03-01

    Primary scientific literature can be difficult to navigate for anyone unfamiliar with its foreign, formal structure. We sought to create a fun, easy learning tool to help familiarize students of all ages with the structure of a scientific article. Our main learning objective was for the student to realize that science writing is formulaic-that specific information is found in predictable locations within an article-and that, with an understanding of the formula, anyone can comfortably navigate any journal article and accurately predict what to expect to find in each section. To this end, we designed a Journal Article Scavenger Hunt that requires the user to find and identify a series of commonplace features of a primary research article. The scavenger hunt activity is quick and easy to implement, and is adaptable to various ages and settings, including the classroom, lab, and at outreach events. The questions in the scavenger hunt can be scaled in difficulty and specificity to suit the instructor's needs. Over many years of using this activity, we have received positive feedback from students of all ages, from elementary school students to lay adult-learners as well as science teachers themselves. By making the unknown seem predictable and approachable, the scavenger hunt helps a variety of audiences feel more comfortable with science and more confident in their ability to engage directly with the scientific literature. Journal of Microbiology & Biology Education.

  15. Ambient RF energy scavenging: GSM and WLAN power density measurements

    NARCIS (Netherlands)

    Visser, H.J.; Reniers, A.C.F.; Theeuwes, J.A.C.

    2009-01-01

    To assess the feasibility of ambient RF energy scavenging, a survey of expected power density levels distant from GSM-900 and GSM-1800 base stations has been conducted and power density measurements have been performed in a WLAN environment. It appears that for distances ranging from 25 m to 100 m

  16. Forensically significant scavenging guilds in the southwest of Western Australia.

    Science.gov (United States)

    O'Brien, R Christopher; Forbes, Shari L; Meyer, Jan; Dadour, Ian

    2010-05-20

    Estimation of time since death is an important factor in forensic investigations and the state of decomposition of a body is a prime basis for such estimations. The rate of decomposition is, however, affected by many environmental factors such as temperature, rainfall, and solar radiation as well as by indoor or outdoor location, covering and the type of surface the body is resting upon. Scavenging has the potential for major impact upon the rate of decomposition of a body, but there is little direct research upon its effect. The information that is available relates almost exclusively to North American and European contexts. The Australian faunal assemblage is unique in that it includes no native large predators or large detrivorous avians. This research investigates the animals that scavenge carcasses in natural outdoor settings in southern Western Australia and the factors which can affect each scavenger's activity. The research was conducted at four locations around Perth, Western Australia with different environmental conditions. Pig carcasses, acting as models for the human body, were positioned in an outdoor environment with no protection from scavengers or other environmental conditions. Twenty-four hour continuous time-lapse video capture was used to observe the pattern of visits of all animals to the carcasses. The time of day, length of feeding, material fed upon, area of feeding, and any movement of the carcass were recorded for each feeding event. Some species were observed to scavenge almost continually throughout the day and night. Insectivores visited the carcasses mostly during bloat and putrefaction; omnivores fed during all stages of decomposition and scavenging by carnivores, rare at any time, was most likely to occur during the early stages of decomposition. Avian species, which were the most prolific visitors to the carcasses in all locations, like reptiles, fed only during daylight hours. Only mammals and amphibians, which were seldom seen

  17. Free radical scavenging injectable hydrogels for regenerative therapy.

    Science.gov (United States)

    Komeri, Remya; Thankam, Finosh Gnanaprakasam; Muthu, Jayabalan

    2017-02-01

    Pathological free radicals generated from inflamed and infarcted cardiac tissues interferes natural tissue repair mechanisms. Hypoxic microenvironment at the injured zone of non-regenerating cardiac tissues hinders the therapeutic attempts including cell therapy. Here we report an injectable, cytocompatible, free radical scavenging synthetic hydrogel formulation for regenerative therapy. New hydrogel (PEAX-P) is prepared with D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer (PEAX) and PEGDiacrylate. PEAX-P hydrogel swells 4.9 times the initial weight and retains 100.07kPa Young modulus at equilibrium swelling, which is suitable for cardiac applications. PEAX-P hydrogel retains elastic nature even at 60% compressive strain, which is favorable to fit with the dynamic and elastic natural tissue counterparts. PEAX-P hydrogel scavenges 51% DPPH radical, 40% hydroxyl radicals 41% nitrate radicals with 31% reducing power. The presence of hydrogel protects 62% cardiomyoblast cells treated with stress inducing media at LD 50 concentration. The free hydroxyl groups in sugar alcohols of the comacromer influence the free radical scavenging. Comparatively, PEAX-P hydrogel based on xylitol evinces slightly lower scavenging characteristics than with previously reported PEAM-P hydrogel containing mannitol having more hydroxyl groups. The possible free radical scavenging mechanism of the present hydrogel relies on the free π electrons associated with uncrosslinked fumarate bonds, hydrogen atoms associated with sugar alcohols/PEG and radical dilution by free water in the matrix. Briefly, the present PEAX-P hydrogel is a potential injectable system for combined antioxidant and regenerative therapy. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Greenland sharks (Somniosus microcephalus scavenge offal from minke (Balaenoptera acutorostrata whaling operations in Svalbard (Norway

    Directory of Open Access Journals (Sweden)

    Lisa-Marie Leclerc

    2011-06-01

    Full Text Available Minke whale (Balaenoptera acutorostrata tissue (mainly blubber was found in the gastrointestinal tracks of Greenland sharks (Somniosus microcephalus collected in Kongsfjorden, Svalbard, Norway. In order to determine whether the sharks were actively hunting the whales, finding naturally dead whales or consuming offal from whaling, we checked the genetic identity of the whale tissue found in the sharks against the DNA register for minke whales taken in Norwegian whaling operations. All of the minke whale samples from the sharks that had DNA of sufficient quality to perform individual identifications were traceable to the whaling DNA register. During whaling operations, the blubber is stripped from the carcass and thrown overboard. The blubber strips float on the surface and are available for surface-feeding predators. This study revealed that Greenland sharks are scavenging this material; additionally, it demonstrates the capacity of this ‘benthic-feeding’ shark to utilize the whole water column for foraging.

  19. Radical scavenging behavior of eriodictyol and fustin flavonoid compounds - A DFT study

    Science.gov (United States)

    Sadasivam, K.; Praveena, R.; Anbakzhakan, K.

    2018-05-01

    The density functional theory (DFT) protocol together with B3LYP/6-311G(d,p) level of theory has been utilized to explore and compare the structural features and molecular characteristics of two naturally occurring flavonoid compounds eriodictyol and fustin. The -OH bond dissociation energy (BDE) for all the radical species have been computed and interpreted in accordance with the radical scavenging activity. The ionization potential (IP) value of fustin flavonoid compound was found to be within the range of synthetic food additives. The polar nature and their capacity to polarise other atoms are established through the dipole moment analysis. Additionally, various parameters that are relevant to chemical potential such as electron affinity, hardness, softness, electro negativity and electrophilic index were calculated and analysed in the light of quercetin flavonoid compound in view of their antioxidant activity. The antioxidant capability of fustin is found to be superior to eriodictyol flavonoid.

  20. Capacity Building

    International Nuclear Information System (INIS)

    Molloy, Brian; Mallick, Shahid

    2014-01-01

    Outcomes & Recommendations: • Significant increase needed in the nuclear workforce both to replace soon-to-retire current generation and to staff large numbers of new units planned • Key message, was the importance of an integrated approach to workforce development. • IAEA and other International Organisations were asked to continue to work on Knowledge Management, Networks and E&T activities • IAEA requested to conduct Global Survey of HR needs – survey initiated but only 50% of operating countries (30% of capacity) took part, so results inconclusive

  1. Fermentation of Smilax china root by Aspergillus usami and Saccharomyces cerevisiae promoted concentration of resveratrol and oxyresveratrol and the free-radical scavenging activity.

    Science.gov (United States)

    Yoon, So-Ra; Yang, Seung-Hwan; Suh, Joo-Won; Shim, Soon-Mi

    2014-07-01

    Smilax china root, which is rich in resveratrol and oxyresveratrol, has been used as emergency foods as well as folk medicine. This study investigated changes in concentration of bioactive components and the free-radical scavenging capacity of Smilax china root during fermentation by Aspergillus usami and Saccharomyces cerevisiae. Resveratrol, oxyresveratrol and piceid were quantified as major constituents in Smilax china root by using UPLC-ESI-MS. The concentration of oxyresveratrol and resveratrol remarkably increased through fermentation and the transformation of piceid to resveratrol. Its concentration in 4% Smilax china root was 1.16-2.95 times higher than that of a 2% preparation throughout fermentation. The vitamin C equivalent antioxidant capacity of 2% Smilax china root was 1.51-1.91 times higher than that of 4% Smilax china root during fermentation. Meanwhile, ABTS free-radical scavenging capacity was enhanced up to 95.07 and 99.35% for 2% and 4% Smilax china root, respectively. Results from our study propose that bioactive components in Smilax China root were highly extracted by fermentation followed by saccharification and ethanol production, resulting in enhanced free-radical scavenging capacity. © 2013 Society of Chemical Industry. © 2013 Society of Chemical Industry.

  2. Free radical scavenging potential, reducing power, phenolic and biochemical constituents of Porphyra species from India

    Digital Repository Service at National Institute of Oceanography (India)

    Pise, N.M.; Jena, K.B.; Maharana, D.; Gaikwad, D.; Jagtap, T.G.

    . Antioxidant potentials of algae were assessed through phenolic content, 2, 2-diphenyl-1- picrylhydrazyl (DPPH) activity, hydrogen peroxide (H sub(2)O sub(2)), scavenging power and reducing potential. A dose-dependent free radical scavenging action against DPPH...

  3. HPLC-Analysis of Polyphenolic Compounds in Gardenia jasminoides and Determination of Antioxidant Activity by Using Free Radical Scavenging Assays

    Directory of Open Access Journals (Sweden)

    Riaz Uddin

    2014-05-01

    Full Text Available Purpose: Gardenia jasminoides is a traditional medicinal plant rich in anti-inflammatory flavonoids and phenolic compounds and used for the treatment of inflammatory diseases and pain. In this present study, antioxidant potential of Gardenia jasminoides leaves extract was evaluated by using various antioxidant assays. Methods: Various antioxidant assays such as 1, 1-diphenyl-2-picrylhydrazyl (DPPH radical scavenging assay, reducing power and total antioxidant capacity expressed as equivalent to ascorbic acid were employed. Moreover, phenolic compounds were detected by high-performance liquid chromatography (HPLC coupled with diode-array detection. Results: The methanol extract showed significant free radical scavenging activities in DPPH radical scavenging antioxidant assays compared to the reference antioxidant ascorbic acid. Total antioxidant activity was increased in a dose dependent manner. The extract also showed strong reducing power. The total phenolic content was determined as 190.97 mg/g of gallic acid equivalent. HPLC coupled with diode-array detection was used to identify and quantify the phenolic compounds in the extracts. Gallic acid, (+-catechin, rutin hydrate and quercetin have been identified in the plant extracts. Among the phenolic compounds, catechin and rutin hydrate are present predominantly in the extract. The accuracy and precision of the presented method were corroborated by low intra- and inter-day variations in quantitative results in leaves extract. Conclusion: These results suggest that phenolic compounds and flavonoids might contribute to high antioxidant activities of Gardenia jasminoides leaves.

  4. Highly functionalized piperidines: Free radical scavenging, anticancer activity, DNA interaction and correlation with biological activity

    OpenAIRE

    Suvankar Das; Cristiane J. da Silva; Marina de M. Silva; Maria Dayanne de A. Dantas; Ângelo de Fátima; Ana Lúcia T. Góis Ruiz; Cleiton M. da Silva; João Ernesto de Carvalho; Josué C.C. Santos; Isis M. Figueiredo; Edeildo F. da Silva-Júnior; Thiago M. de Aquino; João X. de Araújo-Júnior; Goutam Brahmachari; Luzia Valentina Modolo

    2018-01-01

    Twenty-five piperidines were studied as potential radical scavengers and antitumor agents. Quantitative interaction of compounds with ctDNA using spectroscopic techniques was also evaluated. Our results demonstrate that the evaluated piperidines possesses different abilities to scavenge the radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the anion radical superoxide (·O2−). The piperidine 19 was the most potent radical DPPH scavenger, while the most effective to ·O2− scavenger was piperidine...

  5. Superoxide scavenging activity of pirfenidone-iron complex

    International Nuclear Information System (INIS)

    Mitani, Yoshihiro; Sato, Keizo; Muramoto, Yosuke; Karakawa, Tomohiro; Kitamado, Masataka; Iwanaga, Tatsuya; Nabeshima, Tetsuji; Maruyama, Kumiko; Nakagawa, Kazuko; Ishida, Kazuhiko; Sasamoto, Kazumi

    2008-01-01

    Pirfenidone (PFD) is focused on a new anti-fibrotic drug, which can minimize lung fibrosis etc. We evaluated the superoxide (O 2 ·- ) scavenging activities of PFD and the PFD-iron complex by electron spin resonance (ESR) spectroscopy, luminol-dependent chemiluminescence assay, and cytochrome c reduction assay. Firstly, we confirmed that the PFD-iron complex was formed by mixing iron chloride with threefold molar PFD, and the complex was stable in distillated water and ethanol. Secondary, the PFD-iron complex reduced the amount of O 2 ·- produced by xanthine oxidase/hypoxanthine without inhibiting the enzyme activity. Thirdly, it also reduced the amount of O 2 ·- released from phorbor ester-stimulated human neutrophils. PFD alone showed few such effects. These results suggest the possibility that the O 2 ·- scavenging effect of the PFD-iron complex contributes to the anti-fibrotic action of PFD used for treating idiopathic pulmonary fibrosis

  6. The significance of cooking for early hominin scavenging.

    Science.gov (United States)

    Smith, Alex R; Carmody, Rachel N; Dutton, Rachel J; Wrangham, Richard W

    2015-07-01

    Meat scavenged by early Homo could have contributed importantly to a higher-quality diet. However, it has been suggested that because carrion would normally have been contaminated by bacteria it would have been dangerous and therefore eaten rarely prior to the advent of cooking. In this study, we quantified bacterial loads on two tissues apparently eaten by hominins, meat and bone marrow. We tested the following three hypotheses: (1) the bacterial loads on exposed surfaces of raw meat increase within 24 h to potentially dangerous levels, (2) simple roasting of meat on hot coals kills most bacteria, and (3) fewer bacteria grow on marrow than on meat, making marrow a relatively safe food. Our results supported all three hypotheses. Our experimental data imply that early hominins would have found it difficult to scavenge safely without focusing on marrow, employing strategies of carrion selection to minimize pathogen load, or cooking. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Radical scavenging compounds from the aerial parts of ...

    African Journals Online (AJOL)

    Results: The ethyl acetate and n-butanol fractions were the most active fractions and contained apigenin, apigenin glucuronide, luteolin, caffeic acid, methyl caffeate, rosmarinic acid and methyl rosmarinate as the radical scavenging compounds with EC50 values of 26.67 ± 0.31, 185.89 ± 1.02, 5.35 ± 0.31, 3.92 ± 0.06, ...

  8. Radical scavenging activities of Rio Red grapefruits and Sour orange fruit extracts in different in vitro model systems.

    Science.gov (United States)

    Jayaprakasha, G K; Girennavar, Basavaraj; Patil, Bhimanagouda S

    2008-07-01

    Antioxidant fractions from two different citrus species such as Rio Red (Citrus paradise Macf.) and Sour orange (Citrus aurantium L.) were extracted with five different polar solvents using Soxhlet type extractor. The total phenolic content of the extracts was determined by Folin-Ciocalteu method. Ethyl acetate extract of Rio Red and Sour orange was found to contain maximum phenolics. The dried fractions were screened for their antioxidant activity potential using in vitro model systems such as 1,1-diphenyl-2-picryl hydrazyl (DPPH), phosphomolybdenum method and nitroblue tetrazolium (NBT) reduction at different concentrations. The methanol:water (80:20) fraction of Rio Red showed the highest radical scavenging activity 42.5%, 77.8% and 92.1% at 250, 500 and 1000 ppm, respectively, while methanol:water (80:20) fraction of Sour orange showed the lowest radical scavenging activity at all the tested concentrations. All citrus fractions showed good antioxidant capacity by the formation of phosphomolybdenum complex at 200 ppm. In addition, superoxide radical scavenging activity was assayed using non-enzymatic (NADH/phenaxine methosulfate) superoxide generating system. All the extracts showed variable superoxide radical scavenging activity. Moreover, methanol:water (80:20) extract of Rio Red and methanol extract of Sour orange exhibited marked reducing power in potassium ferricyanide reduction method. The data obtained using above in vitro models clearly establish the antioxidant potential of citrus fruit extracts. However, comprehensive studies need to be conducted to ascertain the in vivo bioavailability, safety and efficacy of such extracts in experimental animals. To the best of our knowledge, this is the first report on antioxidant activity of different polar extracts from Rio Red and Sour oranges.

  9. In vitro free radical scavenging activity of platinum nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Aki; Kajita, Masashi; Kim, Juewon; Kanayama, Atsuhiro; Miyamoto, Yusei [Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Bioscience Building 402, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562 (Japan); Takahashi, Kyoko; Mashino, Tadahiko, E-mail: yusei74@k.u-tokyo.ac.j [Department of Pharmaceutical Sciences, Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato, Tokyo 105-8512 (Japan)

    2009-11-11

    A polyacrylic acid (PAA)-protected platinum nanoparticle species (PAA-Pt) was prepared by alcohol reduction of hexachloroplatinate. The PAA-Pt nanoparticles were well dispersed and homogeneous in size with an average diameter of 2.0 {+-} 0.4 nm (n = 200). We used electron spin resonance to quantify the residual peroxyl radical AOO. generated from 2,2-azobis (2-aminopropane) dihydrochloride (AAPH) by thermal decomposition in the presence of O{sub 2} and a spectrophotometric method to quantify the residual 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. PAA-Pt scavenged these two radicals in a dose-dependent manner. Platinum was the functional component. PAA-Pt reduced the rate of oxygen consumption required for linoleic acid peroxidation initiated by AOO. generated from AAPH, indicating inhibition of the propagation of linolate peroxidation. A thiobarbituric acid test also revealed dose-dependent inhibition of the linolate peroxidation by PAA-Pt. Fifty micromolar platinum, as PAA-Pt, completely quenched 250 {mu}M DPPH radical for 5 min. Even when twice diluted in half, the PAA-Pt still quenched 100% of the 250 {mu}M DPPH radical. The scavenging activity of PAA-Pt is durable. These observations suggest that PAA-Pt is an efficient scavenger of free radicals.

  10. Scavenging of radionuclides in the marine environment, (1)

    International Nuclear Information System (INIS)

    Mahara, Yasunori

    1989-01-01

    It is very important to predict diffusion, scavenging and accumulation of the long lives radionuclides which may be discharged from the reprocessing plant in the marine environment, for the purpose of polishing up methods of the radiation does estimation to the high quality stage. This study reports that distribution and behavior of transuranic elements, which are extremely harmful for the human beings and are discharged probably from the reprocessing plant, are investigated in both the survey of bibliography and the in-situ observation. Results of the field observation on the distribution of transuranic elements in the marine show that plutonium and americium are easily scavenged from the sea water and are accumulated on the sea bottom. Transuranic elements, which are originated from fallout and are discharged from the reprocessing plant, have generally the similar distribution in the marine and the same chemical behavior. This facts suggest that the fallout data which are probably and easily collected in the world are available for fabrication of the scavenging model for transuranic elements discharged from the reprocessing plants. (author)

  11. Diet and scavenging habits of the smooth skate Dipturus innominatus.

    Science.gov (United States)

    Forman, J S; Dunn, M R

    2012-04-01

    The diet of smooth skate Dipturus innominatus was determined from examination of stomach contents of 321 specimens of 29·3-152·0 cm pelvic length, sampled from research and commercial trawlers at depths of 231-789 m on Chatham Rise, New Zealand. The diet was dominated by the benthic decapods Metanephrops challengeri and Munida gracilis, the natant decapod Campylonotus rathbunae and fishes from 17 families, of which hoki Macruronus novaezelandiae, sea perch Helicolenus barathri, various Macrouridae and a variety of discarded fishes were the most important. Multivariate analyses indicated the best predictors of diet variability were D. innominatus length and a spatial model. The diet of small D. innominatus was predominantly small crustaceans, with larger crustaceans, fishes and then scavenged discarded fishes increasing in importance as D. innominatus got larger. Scavenged discards were obvious as fish heads or tails only, or skeletal remains after filleting, often from pelagic species. Demersal fish prey were most frequent on the south and west Chatham Rise, in areas where commercial fishing was most active. Dipturus innominatus are highly vulnerable to overfishing, but discarding practices by commercial fishing vessels may provide a positive feedback to populations through improved scavenging opportunities. © 2012 NIWA. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  12. Body Size as a Driver of Scavenging in Theropod Dinosaurs.

    Science.gov (United States)

    Kane, Adam; Healy, Kevin; Ruxton, Graeme D; Jackson, Andrew L

    2016-06-01

    Theropod dinosaurs dominated Earth's terrestrial ecosystem as a diverse group of predators for more than 160 million years, yet little is known about their foraging ecology. Maintaining a balanced energy budget presented a major challenge for therapods, which ranged from the chicken-sized Microraptor up to the whale-sized Giganotosaurus, in the face of intense competition and the demands of ontogenetic growth. Facultative scavenging, a behavior present in almost all modern predators, may have been important in supplementing energetically expensive lifestyles. By using agent-based models based on the allometric relationship between size and foraging behaviors, we show that theropods between 27 and 1,044 kg would have gained a significant energetic advantage over individuals at both the small and large extremes of theropod body mass through their scavenging efficiency. These results were robust to rate of competition, primary productivity, and detection distance. Our models demonstrate the potential importance of facultative scavenging in theropods and the role of body size in defining its prevalence in Mesozoic terrestrial systems.

  13. Scavenger Receptor CD163 and Its Biological Functions

    Directory of Open Access Journals (Sweden)

    Gabriela Onofre

    2009-01-01

    Full Text Available CD163 is a member of scavenger receptor super family class B of the first subgroup. It is mapped to the region p13 on chromosome 12. Five different isoforms of CD163 have been described, which differ in the structure of their cytoplasmic domains and putative phosporylation sites. This scavenger receptor is selectively expressed on cells of monocytes and macrophages lineage exclusively. CD163 immunological function is essentially homeostatic. It also has other functions because participates in adhesion to endothelial cells, in tolerance induction and tissues regeneration. Other very important function of CD163 is the clearance of hemoglobin in its cell-free form and participation in anti-inflammation in its soluble form, exhibiting cytokine-like functions. We review the biological functions of CD163 which have been discovered until now. It seems apparent from this review that CD163 scavenger receptor can be used as biomarker in different diseases and as a valuable diagnostic parameter for prognosis of many diseases especially inflammatory disorders and sepsis.

  14. Shape similarities and differences in the skulls of scavenging raptors.

    Science.gov (United States)

    Guangdi, S I; Dong, Yiyi; Ma, Yujun; Zhang, Zihui

    2015-04-01

    Feeding adaptations are a conspicuous feature of avian evolution. Bill and cranial shape as well as the jaw muscles are closely related to diet choice and feeding behaviors. Diurnal raptors of Falconiformes exhibit a wide range of foraging behaviors and prey preferences, and are assigned to seven dietary groups in this study. Skulls of 156 species are compared from the dorsal, lateral and ventral views, by using geometric morphometric techniques with those landmarks capturing as much information as possible on the overall shape of cranium, bill, orbits, nostrils and attachment area for different jaw muscles. The morphometric data showed that the skull shape of scavengers differ significantly from other raptors, primarily because of different feeding adaptations. As a result of convergent evolution, different scavengers share generalized common morphology, possessing relatively slender and lower skulls, longer bills, smaller and more sideward orbits, and more caudally positioned quadrates. Significant phylogenetic signals suggested that phylogeny also played important role in shape variation within scavengers. New World vultures can be distinguished by their large nostrils, narrow crania and small orbits; Caracaras typically show large palatines, crania and orbits, as well as short, deep and sharp bill.

  15. Separation of nanoparticles: Filtration and scavenging from waste incineration plants.

    Science.gov (United States)

    Förster, Henning; Thajudeen, Thaseem; Funk, Christine; Peukert, Wolfgang

    2016-06-01

    Increased amounts of nanoparticles are applied in products of everyday life and despite material recycling efforts, at the end of their life cycle they are fed into waste incineration plants. This raises the question on the fate of nanoparticles during incineration. In terms of environmental impact the key question is how well airborne nanoparticles are removed by separation processes on their way to the bag house filters and by the existing filtration process based on pulse-jet cleanable fibrous filter media. Therefore, we investigate the scavenging and the filtration of metal nanoparticles under typical conditions in waste incineration plants. The scavenging process is investigated by a population balance model while the nanoparticle filtration experiments are realized in a filter test rig. The results show that depending on the particle sizes, in some cases nearly 80% of the nanoparticles are scavenged by fly ash particles before they reach the bag house filter. For the filtration step dust cakes with a pressure drop of 500Pa or higher are found to be very effective in preventing nanoparticles from penetrating through the filter. Thus, regeneration of the filter must be undertaken with care in order to guarantee highly efficient collection of particles even in the lower nanometre size regime. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. The evolution of the class A scavenger receptors

    Directory of Open Access Journals (Sweden)

    Whelan Fiona J

    2012-11-01

    Full Text Available Abstract Background The class A scavenger receptors are a subclass of a diverse family of proteins defined based on their ability to bind modified lipoproteins. The 5 members of this family are strikingly variable in their protein structure and function, raising the question as to whether it is appropriate to group them as a family based on their ligand binding abilities. Results To investigate these relationships, we defined the domain architecture of each of the 5 members followed by collecting and annotating class A scavenger receptor mRNA and amino acid sequences from publicly available databases. Phylogenetic analyses, sequence alignments, and permutation tests revealed a common evolutionary ancestry of these proteins, indicating that they form a protein family. We postulate that 4 distinct gene duplication events and subsequent domain fusions, internal repeats, and deletions are responsible for the diverse protein structures and functions of this family. Despite variation in domain structure, there are highly conserved regions across all 5 members, indicating the possibility that these regions may represent key conserved functional motifs. Conclusions We have shown with significant evidence that the 5 members of the class A scavenger receptors form a protein family. We have indicated that these receptors have a common origin which may provide insight into future functional work with these proteins.

  17. Radical-Scavenging Activity and Ferric Reducing Ability of Juniperus thurifera (L.), J. oxycedrus (L.), J. phoenicea (L.) and Tetraclinis articulata (L.)

    OpenAIRE

    El Jemli, Meryem; Kamal, Rabie; Marmouzi, Ilias; Zerrouki, Asmae; Cherrah, Yahia; Alaoui, Katim

    2016-01-01

    Objective. The aim of this work is to study and compare the antioxidant properties and phenolic contents of aqueous leaf extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus Phoenicea, and Tetraclinis articulata from Morocco. Methods. Antioxidant activities of the extracts were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging ability, Trolox equivalent antioxidant capacity (TEAC), and ferric reducing antioxidant power (FRAP) assays. Also the total phenolic ...

  18. Spatial complexity of carcass location influences vertebrate scavenger efficiency and species composition.

    Science.gov (United States)

    Smith, Joshua B; Laatsch, Lauren J; Beasley, James C

    2017-08-31

    Scavenging plays an important role in shaping communities through inter- and intra-specific interactions. Although vertebrate scavenger efficiency and species composition is likely influenced by the spatial complexity of environments, heterogeneity in carrion distribution has largely been disregarded in scavenging studies. We tested this hypothesis by experimentally placing juvenile bird carcasses on the ground and in nests in trees to simulate scenarios of nestling bird carrion availability. We used cameras to record scavengers removing carcasses and elapsed time to removal. Carrion placed on the ground was scavenged by a greater diversity of vertebrates and at > 2 times the rate of arboreal carcasses, suggesting arboreal carrion may represent an important resource to invertebrate scavengers, particularly in landscapes with efficient vertebrate scavenging communities. Nonetheless, six vertebrate species scavenged arboreal carcasses. Rat snakes (Elaphe obsolete), which exclusively scavenged from trees, and turkey vultures (Cathartes aura) were the primary scavengers of arboreal carrion, suggesting such resources are potentially an important pathway of nutrient acquisition for some volant and scansorial vertebrates. Our results highlight the intricacy of carrion-derived food web linkages, and how consideration of spatial complexity in carcass distribution (i.e., arboreal) may reveal important pathways of nutrient acquisition by invertebrate and vertebrate scavenging guilds.

  19. Integrated Analysis of the Scavenging Process in Marine Two-Stroke Diesel Engines

    DEFF Research Database (Denmark)

    Andersen, Fredrik Herland

    Large commercial ships such as container vessels and bulk carriers are propelledby low-speed, uniow scavenged two-stroke diesel engines. An integralin-cylinder process in this type of engine is the scavenging process, where the burned gases from the combustion process are evacuated through...... receiver fora two-stroke diesel engine. Time resolved boundary conditions corresponding to measurements obtained from an operating engine as well as realistic initial conditions are used in the simulations. The CFD model provides a detailed description of the in-cylinder ow from exhaust valve opening (EVO...... in the scavenge and exhaust receivers increase while the scavenge port exposure time, tscav, decrease. Further the scavenging pressure is varied while the engine speed is kept constant. From the perspective of the scavenging process this will resemble a load sweep following a generator curve. The scavenge port...

  20. Antioxidant capacity of Macaronesian traditional medicinal plants.

    Science.gov (United States)

    Tavares, Lucélia; Carrilho, Dina; Tyagi, Meenu; Barata, David; Serra, Ana Teresa; Duarte, Catarina Maria Martins; Duarte, Rui Oliveira; Feliciano, Rodrigo Pedro; Bronze, Maria Rosário; Chicau, Paula; Espírito-Santo, Maria Dalila; Ferreira, Ricardo Boavida; dos Santos, Cláudia Nunes

    2010-04-12

    The use of many traditional medicinal plants is often hampered by the absence of a proper biochemical characterization, essential to identify the bioactive compounds present. The leaves from five species endemic to the Macaronesian islands with recognized ethnobotanical applications were analysed: Apollonias barbujana (Cav.) Bornm., Ocotea foetens (Ainton) Baill, Prunus azorica (Mouill.) Rivas-Mart., Lousã, Fern. Prieto, E. Días, J.C. Costa & C. Aguiar, Rumex maderensis Lowe and Plantago arborescens Poir. subsp. maderensis (Dcne.) A. Hans. et Kunk.. Since oxidative stress is a common feature of most diseases traditionally treated by these plants, it is important to assess their antioxidant capacity and determine the molecules responsible for this capacity. In this study, the antioxidant capacity of these plants against two of the most important reactive species in human body (hydroxyl and peroxyl radicals) was determined. To trace the antioxidant origin total phenol and flavonoid contents as well as the polyphenolic profile and the amount of trace elements were determined. There was a wide variation among the species analysed in what concerns their total leaf phenol and flavonoid contents. From the High Performance Liquid Chromatography (HPLC) electrochemically detected peaks it was possible to attribute to flavonoids the antioxidant capacity detected in A. barbujana, O. foetens, R. maderensis and P. azorica extracts. These potential reactive flavonoids were identified for A. barbujana, R. maderensis and P. azorica. For R. maderensis a high content (7 mg g-1 dry weight) of L-ascorbic acid, an already described antioxidant phytomolecule, was found. A high content in selenomethionine (414.35 microg g-1 dry weight) was obtained for P. arborescens subsp. maderensis extract. This selenocompound is already described as a hydroxyl radical scavenger is reported in this work as also possessing peroxyl radical scavenging capacity. This work is a good illustration of

  1. Habitat of in vivo transformation influences the levels of free radical scavengers in Clinostomum complanatum: implications for free radical scavenger based vaccines against trematode infections.

    Science.gov (United States)

    Zafar, Atif; Rizvi, Asim; Ahmad, Irshad; Ahmad, Masood

    2014-01-01

    Since free radical scavengers of parasite origin like glutathione-S-transferase and superoxide dismutase are being explored as prospective vaccine targets, availability of these molecules within the parasite infecting different hosts as well as different sites of infection is of considerable importance. Using Clinostomum complanatum, as a model helminth parasite, we analysed the effects of habitat of in vivo transformation on free radical scavengers of this trematode parasite. Using three different animal models for in vivo transformation and markedly different sites of infection, progenetic metacercaria of C. complanatum were transformed to adult ovigerous worms. Whole worm homogenates were used to estimate the levels of lipid peroxidation, a marker of oxidative stress and free radical scavengers. Site of in vivo transformation was found to drastically affect the levels of free radical scavengers in this model trematode parasite. It was observed that oxygen availability at the site of infection probably influences levels of free radical scavengers in trematode parasites. This is the first report showing that habitat of in vivo transformation affects levels of free radical scavengers in trematode parasites. Since free radical scavengers are prospective vaccine targets and parasite infection at ectopic sites is common, we propose that infections at different sites, may respond differently to free radical scavenger based vaccines.

  2. Scavenging of particulate elemental carbon into stratus cloud

    Energy Technology Data Exchange (ETDEWEB)

    Kaneyasu, Naoki; Maeda, Takahisa [National Inst. for Resources and Environment, Tsukuba (Japan)

    1995-12-31

    The role of atmospheric aerosols on the alternation of cloud radiative properties has widely been recognized since 1977 when Tomey and his coworkers have numerically demonstrated the effect of increased cloud condensation nuclei (CCN). At the same time, cloud processes are one of the most important factor in controlling the residence time of atmospheric aerosols through the wet removal process. The redistribution of the size and the composition of pre-cloud aerosols is also the important role of cloud process on the nature of atmospheric aerosols. In order to study these cloud-aerosol interaction phenomena, the incorporation of aerosols into cloud droplets is the first mechanism to be investigated. Among the several mechanisms for the incorporation of aerosols into cloud droplets, nucleation scavenging, is the potentially important process in the view of cloud-aerosol interactions. This critical supersaturation for a given radius of a particle can be theoretically calculated only for pure species, e.g., NaCl. However, a significant portion of the atmospheric aerosols is in the form of internal mixture of multiple components, such as SO{sub 4}{sup 2-}, NO{sub 3}{sup -}, NH{sub 4}{sup +} and particulate elemental carbon. The knowledge acquired by field measurements is therefore essential on this subject. The present study focuses on the scavenging of major components of urban atmospheric aerosols, in particular the incorporation of particulate elemental carbon into stratus cloud. Particulate elemental carbon is the strongest light absorbing species in visible region, and has potential to change the optical property of cloud. On the basis of the measurements conducted at a mountain located in the suburb of Tokyo Metropolitan area, Japan, some insights on the scavenging of particulate elemental carbon into cloud droplet will be presented

  3. Scavenging of particulate elemental carbon into stratus cloud

    Energy Technology Data Exchange (ETDEWEB)

    Kaneyasu, Naoki; Maeda, Takahisa [National Inst. for Resources and Environment, Tsukuba (Japan)

    1996-12-31

    The role of atmospheric aerosols on the alternation of cloud radiative properties has widely been recognized since 1977 when Tomey and his coworkers have numerically demonstrated the effect of increased cloud condensation nuclei (CCN). At the same time, cloud processes are one of the most important factor in controlling the residence time of atmospheric aerosols through the wet removal process. The redistribution of the size and the composition of pre-cloud aerosols is also the important role of cloud process on the nature of atmospheric aerosols. In order to study these cloud-aerosol interaction phenomena, the incorporation of aerosols into cloud droplets is the first mechanism to be investigated. Among the several mechanisms for the incorporation of aerosols into cloud droplets, nucleation scavenging, is the potentially important process in the view of cloud-aerosol interactions. This critical supersaturation for a given radius of a particle can be theoretically calculated only for pure species, e.g., NaCl. However, a significant portion of the atmospheric aerosols is in the form of internal mixture of multiple components, such as SO{sub 4}{sup 2-}, NO{sub 3}{sup -}, NH{sub 4}{sup +} and particulate elemental carbon. The knowledge acquired by field measurements is therefore essential on this subject. The present study focuses on the scavenging of major components of urban atmospheric aerosols, in particular the incorporation of particulate elemental carbon into stratus cloud. Particulate elemental carbon is the strongest light absorbing species in visible region, and has potential to change the optical property of cloud. On the basis of the measurements conducted at a mountain located in the suburb of Tokyo Metropolitan area, Japan, some insights on the scavenging of particulate elemental carbon into cloud droplet will be presented

  4. Development and validation of a simple high performance thin layer chromatography method combined with direct 1,1-diphenyl-2-picrylhydrazyl assay to quantify free radical scavenging activity in wine.

    Science.gov (United States)

    Agatonovic-Kustrin, Snezana; Morton, David W; Yusof, Ahmad P

    2016-04-15

    The aim of this study was to: (a) develop a simple, high performance thin layer chromatographic (HPTLC) method combined with direct 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay to rapidly assess and compare free radical scavenging activity or anti-oxidant activity for major classes of polyphenolics present in wines; and (b) to investigate relationship between free radical scavenging activity to the total polyphenolic content (TPC) and total antioxidant capacity (TAC) in the wine samples. The most potent free radical scavengers that we tested for in the wine samples were found to be resveratrol (polyphenolic non-flavonoid) and rutin (flavonoid), while polyphenolic acids (caffeic acid and gallic acid) although present in all wine samples were found to be less potent free radical scavengers. Therefore, the total antioxidant capacity was mostly affected by the presence of resveratrol and rutin, while total polyphenolic content was mostly influenced by the presence of the less potent free radical scavengers gallic and caffeic acids. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Trophic facilitation or limitation? Comparative effects of pumas and black bears on the scavenger community.

    Science.gov (United States)

    Allen, Maximilian L; Elbroch, L Mark; Wilmers, Christopher C; Wittmer, Heiko U

    2014-01-01

    Scavenging is a widespread behaviour and an important process influencing food webs and ecological communities. Large carnivores facilitate the movement of energy across trophic levels through the scavenging and decomposition of their killed prey, but competition with large carnivores is also likely to constrain acquisition of carrion by scavengers. We used an experimental approach based on motion-triggered video cameras at black-tailed deer (Odocoileus hemionus columbianus) carcasses to measure the comparative influences of two large carnivores in the facilitation and limitation of carrion acquisition by scavengers. We found that pumas (Puma concolor) and black bears (Ursus americanus) had different effects on their ecological communities. Pumas, as a top-level predator, facilitated the consumption of carrion by scavengers, despite significantly reducing their observed sum feeding times (165.7 min ± 21.2 SE at puma kills 264.3 min ± 30.1 SE at control carcasses). In contrast, black bears, as the dominant scavenger in the system, limited consumption of carrion by scavengers as evidenced by the observed reduction of scavenger species richness recorded at carcasses where they were present (mean = 2.33 ± 0.28 SE), compared to where they were absent (mean = 3.28 ± 0.23 SE). Black bears also had large negative effects on scavenger sum feeding times (88.5 min ± 19.8 SE at carcasses where bears were present, 372.3 min ± 50.0 SE at carcasses where bears were absent). In addition, we found that pumas and black bears both increased the nestedness (a higher level of order among species present) of the scavenger community. Our results suggest that scavengers have species-specific adaptions to exploit carrion despite large carnivores, and that large carnivores influence the structure and composition of scavenger communities. The interactions between large carnivores and scavengers should be considered in future studies of food webs and ecological communities.

  6. Trophic facilitation or limitation? Comparative effects of pumas and black bears on the scavenger community.

    Directory of Open Access Journals (Sweden)

    Maximilian L Allen

    Full Text Available Scavenging is a widespread behaviour and an important process influencing food webs and ecological communities. Large carnivores facilitate the movement of energy across trophic levels through the scavenging and decomposition of their killed prey, but competition with large carnivores is also likely to constrain acquisition of carrion by scavengers. We used an experimental approach based on motion-triggered video cameras at black-tailed deer (Odocoileus hemionus columbianus carcasses to measure the comparative influences of two large carnivores in the facilitation and limitation of carrion acquisition by scavengers. We found that pumas (Puma concolor and black bears (Ursus americanus had different effects on their ecological communities. Pumas, as a top-level predator, facilitated the consumption of carrion by scavengers, despite significantly reducing their observed sum feeding times (165.7 min ± 21.2 SE at puma kills 264.3 min ± 30.1 SE at control carcasses. In contrast, black bears, as the dominant scavenger in the system, limited consumption of carrion by scavengers as evidenced by the observed reduction of scavenger species richness recorded at carcasses where they were present (mean = 2.33 ± 0.28 SE, compared to where they were absent (mean = 3.28 ± 0.23 SE. Black bears also had large negative effects on scavenger sum feeding times (88.5 min ± 19.8 SE at carcasses where bears were present, 372.3 min ± 50.0 SE at carcasses where bears were absent. In addition, we found that pumas and black bears both increased the nestedness (a higher level of order among species present of the scavenger community. Our results suggest that scavengers have species-specific adaptions to exploit carrion despite large carnivores, and that large carnivores influence the structure and composition of scavenger communities. The interactions between large carnivores and scavengers should be considered in future studies of food webs and ecological communities.

  7. Loading of free radicals on the functional graphene combined with liquid chromatography-tandem mass spectrometry screening method for the detection of radical-scavenging natural antioxidants.

    Science.gov (United States)

    Wang, Guoying; Shi, Gaofeng; Chen, Xuefu; Chen, Fuwen; Yao, Ruixing; Wang, Zhenju

    2013-11-13

    A novel free radical reaction combined with liquid chromatography electrospray ionization tandem mass spectrometry (FRR-LC-PDA-ESI/APCI-MS/MS) screening method was developed for the detection and identification of radical-scavenging natural antioxidants. Functionalized graphene was prepared by chemical method for loading free radicals (superoxide radical, peroxyl radical and PAHs free radical). Separation was performed with and without a preliminary exposure of the sample to specific free radicals on the functionalized graphene, which can facilitate reaction kinetics (charge transfers) between free radicals and potential antioxidants. The difference in chromatographic peak areas is used to identify potential antioxidants. The structure of the antioxidants in one sample (Swertia chirayita) is identified using MS/MS and comparison with standards. Thirteen compounds were found to possess potential antioxidant activity, and their free radical-scavenging capacities were investigated. The thirteen compounds were identified as 1,3,5-trihydroxyxanthone-8-O-β-D-glucopyranoside (PD1), norswertianin (PD2), 1,3,5,8-tetrahydroxyxanthone (PD3), 3, 3', 4', 5, 8-penta hydroxyflavone-6-β-D-glucopyranosiduronic acid-6'-pentopyranose-7-O-glucopyranoside (PD4), 1,5,8-trihydroxy-3-methoxyxanthone (PD5), swertiamarin (PS1), 2-C-β-D-glucopyranosyl-1,3,7-trihydroxylxanthone (PS2), 1,3,7-trihydroxylxanthone-8-O-β-D-glucopyranoside (PL1), 1,3,8-trihydroxyl xanthone-5-O-β-D-glucopyranoside (PL2), 1,3,7-trihydroxy-8-methoxyxanthone (PL3), 1,2,3-trihydroxy-7,8-dimethoxyxanthone (PL4), 1,8-dihydroxy-2,6-dimethoxy xanthone (PL5) and 1,3,5,8-tetramethoxydecussatin (PL6). The reactivity and SC50 values of those compounds were investigated, respectively. PD4 showed the strongest capability for scavenging PAHs free radical; PL4 showed prominent scavenging capacities in the lipid peroxidation processes; it was found that all components in S. chirayita exhibited weak reactivity in the superoxide

  8. Energy scavenging system by acoustic wave and integrated wireless communication

    Science.gov (United States)

    Kim, Albert

    The purpose of the project was developing an energy-scavenging device for other bio implantable devices. Researchers and scientist have studied energy scavenging method because of the limitation of traditional power source, especially for bio-implantable devices. In this research, piezoelectric power generator that activates by acoustic wave, or music was developed. Follow by power generator, a wireless communication also integrated with the device for monitoring the power generation. The Lead Zirconate Titanate (PZT) bimorph cantilever with a proof mass at the free end tip was studied to convert acoustic wave to power. The music or acoustic wave played through a speaker to vibrate piezoelectric power generator. The LC circuit integrated with the piezoelectric material for purpose of wireless monitoring power generation. However, wireless monitoring can be used as wireless power transmission, which means the signal received via wireless communication also can be used for power for other devices. Size of 74 by 7 by 7cm device could generate and transmit 100mVp from 70 mm distance away with electrical resonant frequency at 420.2 kHz..

  9. Phytoconstituents with Radical Scavenging and Cytotoxic Activities from Diospyros shimbaensis

    Directory of Open Access Journals (Sweden)

    Per Aronsson

    2016-01-01

    Full Text Available As part of our search for natural products having antioxidant and anticancer properties, the phytochemical investigation of Diospyros shimbaensis (Ebenaceae, a plant belonging to a genus widely used in East African traditional medicine, was carried out. From its stem and root barks the new naphthoquinone 8,8′-oxo-biplumbagin (1 was isolated along with the known tetralones trans-isoshinanolone (2 and cis-isoshinanolone (3, and the naphthoquinones plumbagin (4 and 3,3′-biplumbagin (5. Compounds 2, 4, and 5 showed cytotoxicity (IC50 520–82.1 μM against MDA-MB-231 breast cancer cells. Moderate to low cytotoxicity was observed for the hexane, dichloromethane, and methanol extracts of the root bark (IC50 16.1, 29.7 and > 100 μg/mL, respectively, and for the methanol extract of the stem bark (IC50 59.6 μg/mL. The radical scavenging activity of the isolated constituents (1–5 was evaluated on the 2,2-diphenyl-1-picrylhydrazyl (DPPH radical scavenging assay. The applicability of the crude extracts and of the isolated constituents for controlling degenerative diseases is discussed.

  10. Phytoconstituents with Radical Scavenging and Cytotoxic Activities from Diospyros shimbaensis.

    Science.gov (United States)

    Aronsson, Per; Munissi, Joan J E; Gruhonjic, Amra; Fitzpatrick, Paul A; Landberg, Göran; Nyandoro, Stephen S; Erdelyi, Mate

    2016-01-15

    As part of our search for natural products having antioxidant and anticancer properties, the phytochemical investigation of Diospyros shimbaensis (Ebenaceae), a plant belonging to a genus widely used in East African traditional medicine, was carried out. From its stem and root barks the new naphthoquinone 8,8'-oxo-biplumbagin ( 1 ) was isolated along with the known tetralones trans -isoshinanolone ( 2 ) and cis -isoshinanolone ( 3 ), and the naphthoquinones plumbagin ( 4 ) and 3,3'-biplumbagin ( 5 ). Compounds 2 , 4 , and 5 showed cytotoxicity (IC 50 520-82.1 μM) against MDA-MB-231 breast cancer cells. Moderate to low cytotoxicity was observed for the hexane, dichloromethane, and methanol extracts of the root bark (IC 50 16.1, 29.7 and > 100 μg/mL, respectively), and for the methanol extract of the stem bark (IC 50 59.6 μg/mL). The radical scavenging activity of the isolated constituents ( 1 - 5 ) was evaluated on the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. The applicability of the crude extracts and of the isolated constituents for controlling degenerative diseases is discussed.

  11. Development of oxygen scavenger additives for jet fuels

    Energy Technology Data Exchange (ETDEWEB)

    Beaver, B.D.; Demunshi, R.; Sharief, V.; Tian, D.; Teng, Y. [Duquesne Univ., Pittsburgh, PA (United States)

    1995-05-01

    Our current research program is in response to the US Air Force`s FY93 New Initiative entitled {open_quotes}Advanced Fuel Composition and Use.{close_quotes} The critical goal of this initiative is to develop aircraft fuels which can operate at supercritical conditions. This is a vital objective since future aircraft designs will transfer much higher heat loads into the fuel as compared with current heat loads. In this paper it is argued that the thermal stability of most jet fuels would be dramatically improved by the efficient in flight-removal of a fuel`s dissolved oxygen. It is proposed herein to stabilize the bulk fuel by the addition of an additive which will be judiciously designed and programmed to react with oxygen and produce an innocuous product. It is envisioned that a thermally activated reaction will occur, between the oxygen scavenging additive and dissolved oxygen, in a controlled and directed manner. Consequently formation of insoluble thermal degradation products will be limited. It is believed that successful completion of this project will result in the development of a new type of jet fuel additive which will enable current conventional jet fuels to obtain sufficient thermal stability to function in significantly higher temperature regimes. In addition, it is postulated that the successful development of thermally activated oxygen scavengers will also provide the sub-critical thermal stability necessary for future development of endothermic fuels.

  12. Occurrence and distribution of nitrogen-scavenging bacteria in marine environment

    OpenAIRE

    Sugahara, Isao; Kimura, Toshio; Hayashi, Koichiro

    1987-01-01

    The occurrence and distribution nitrogen-scavenging bacteria in the water of coastal and oceanic of Japan were studied during the Seisui-Maru cruises from 1986 to 1987. Nitroben-scavenging bacteria in the water usually occurred at the level of 10-104 cfu/ml.This value was almost comparable to that of aerobic heterotrophic bacteria. It seems that nitrogen-scavenging bacteria play an important role in the efficient uptake of low levels of nitrogenous compounds in marine enviroment.

  13. Assessment of Free Radical Scavenging Activity of Dimethylglycine Sodium Salt and Its Role in Providing Protection against Lipopolysaccharide-Induced Oxidative Stress in Mice.

    Science.gov (United States)

    Bai, Kaiwen; Xu, Wen; Zhang, Jingfei; Kou, Tao; Niu, Yu; Wan, Xiaoli; Zhang, Lili; Wang, Chao; Wang, Tian

    2016-01-01

    In the present study, the free radical scavenging activities (against 1,1-diphenyl-2-pierylhydrazy (DPPH), 2,2'-Azinobis-(3-ethylbenzthiazoline-6- sulphonate) (ABTS+), Hydrogen peroxide (H2O2)) of dimethylglycine sodium salt (DMG-Na) were measured and compared with those of Trolox (6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid), a commonly used antioxidant. The radical scavenging activities of DMG-Na were found to be the highest at 40 mg/ml. In Experiment 2, gastric intubation in mice with 12 mg DMG-Na/0.3 ml sterile saline solution significantly increased (P DMG-Na/0.3 ml sterile saline solution, which showed the highest antioxidant capacity, was further studied using a mice model. In Experiment 3, the mice CL (CON+ lipopolysaccharide (LPS)) group showed a significant decrease (P DMG+LPS) group showed a significant decrease (P DMG-Na could protect against the LPS-induced oxidative stress by enhancing the free radical scavenging capacity, and increasing the activity of antioxidant defense system.

  14. Scavenging efficiency and red fox abundance in Mediterranean mountains with and without vultures

    Science.gov (United States)

    Morales-Reyes, Zebensui; Sánchez-Zapata, José A.; Sebastián-González, Esther; Botella, Francisco; Carrete, Martina; Moleón, Marcos

    2017-02-01

    Vertebrate scavenging assemblages include two major functional groups: obligate scavengers (i.e., vultures), which depend totally on carrion and are undergoing severe declines around the globe, and facultative scavengers, which exploit carrion opportunistically and are generally ubiquitous. Our goal was to investigate the hypothesis that vultures can indirectly regulate the abundance of mesopredators (i.e., facultative scavengers) through modulating their access to carrion resources. We studied scavenging efficiency and red fox (Vulpes vulpes) abundance in two neighbouring areas of South-eastern Spain where vultures (mainly griffon vultures Gyps fulvus) are present (Cazorla) and absent (Espuña). To do so, we monitored ungulate carcasses consumption during winter and summer, and counted red fox scats along walking transects as a proxy of fox density. Our results confirmed that scavenging efficiency was higher in Cazorla and in carcasses visited by vultures. This resulted in increasing scavenging opportunities for facultative scavengers where vultures were absent. Accordingly, mean red fox abundance was higher in Espuña. These results suggest the existence of a vulture-mediated mesopredator release (i.e., an increase of mesopredator numbers following vulture loss), which could trigger important indirect ecological effects. Also, our study demonstrates that facultative scavengers are hardly able to functionally replace vultures, mainly because the former exploit carrion on a slower time scale.

  15. Influence of environmental factors on the contents of active ingredients and radical scavenging property of potentilla fruticosa in the main production areas of China

    International Nuclear Information System (INIS)

    Liu, W.; Yin, D. X.; Wang, D. M.; Li, D. W.

    2015-01-01

    Extracts from Potentilla fruticosa have been applied in traditional medicine and exhibited antioxidant property, but little has been known about the diversity of phytochemicals and properties on this species from different growing environment. This study investigated the influence of environmental factors on the active ingredient contents and radical scavenging property of P. fruticosa from different production areas of China in order to discover a location could produce high-quality resources for pharmaceutical products. The contents of tannin, total flavonoids, and rutin were determined and varied within the range of 7.64 ± 0.43 ∼ 10.68 ± 0.67 percentage, 2.29 ± 0.34 ∼ 5.37 ± 0.36 percentage, and 0.19 ± 0.053 ∼ 0.79 ± 0.125 percentage, respectively. Radical scavenging property was quantified, with the IC /sub 50/ of 7.24 ± 0.423 to 17.23 ± 0.551 μ g mL-1. Principal component analysis, multiple linear stepwise regression analysis, and path analysis were conducted to further analysis the relationship between the variations of active ingredients and radical scavenging capacity and growth environment. The results showed dominant environmental factors for these variations were rapidly available nitrogen, rapidly available phosphorus, pH, July average temperature, and annual sunshine duration. Furthermore, a significant positive correlation was observed between pH, annual sunshine duration and active ingredients and radical scavenging property (p<0.05). Considering the high active ingredient contents and strong radical scavenging property, leaf extracts from P. fruticosa could become useful supplements for pharmaceutical products as a new antioxidant agent, and Huzhu Northern Mountain in Qinghai Province and E-mei Mountain in Sichuan Province were selected as favorable production locations. (author)

  16. Enhanced reactive oxygen species scavenging by overproduction of superoxide dismutase and catalase delays postharvest physiological deterioration of cassava storage roots.

    Science.gov (United States)

    Xu, Jia; Duan, Xiaoguang; Yang, Jun; Beeching, John R; Zhang, Peng

    2013-03-01

    Postharvest physiological deterioration (PPD) of cassava (Manihot esculenta) storage roots is the result of a rapid oxidative burst, which leads to discoloration of the vascular tissues due to the oxidation of phenolic compounds. In this study, coexpression of the reactive oxygen species (ROS)-scavenging enzymes copper/zinc superoxide dismutase (MeCu/ZnSOD) and catalase (MeCAT1) in transgenic cassava was used to explore the intrinsic relationship between ROS scavenging and PPD occurrence. Transgenic cassava plants integrated with the expression cassette p54::MeCu/ZnSOD-35S::MeCAT1 were confirmed by Southern-blot analysis. The expression of MeCu/ZnSOD and MeCAT1 was verified by quantitative reverse transcription-polymerase chain reaction and enzymatic activity analysis both in the leaves and storage roots. Under exposure to the ROS-generating reagent methyl viologen or to hydrogen peroxide (H2O2), the transgenic plants showed higher enzymatic activities of SOD and CAT than the wild-type plants. Levels of malondialdehyde, chlorophyll degradation, lipid peroxidation, and H2O2 accumulation were dramatically reduced in the transgenic lines compared with the wild type. After harvest, the storage roots of transgenic cassava lines show a delay in their PPD response of at least 10 d, accompanied by less mitochondrial oxidation and H2O2 accumulation, compared with those of the wild type. We hypothesize that this is due to the combined ectopic expression of Cu/ZnSOD and CAT leading to an improved synergistic ROS-scavenging capacity of the roots. Our study not only sheds light on the mechanism of the PPD process but also develops an effective approach for delaying the occurrence of PPD in cassava.

  17. Energy scavenging sensors for ultra-low power sensor networks

    Science.gov (United States)

    O'Brien, Dominic C.; Liu, Jing Jing; Faulkner, Grahame E.; Vachiramon, Pithawat; Collins, Steve; Elston, Steven J.

    2010-08-01

    The 'internet of things' will require very low power wireless communications, preferably using sensors that scavenge power from their environment. Free space optics allows communications over long ranges, with simple transceivers at each end, offering the possibility of low energy consumption. In addition there can be sufficient energy in the communications beam to power simple terminals. In this paper we report experimental results from an architecture that achieves this. A base station that tracks sensors in its coverage area and communicates with them using low divergence optical beams is presented. Sensor nodes use modulated retro-reflectors to communicate with the base station, and the nodes are powered by the illuminating beam. The paper presents design and implementation details, as well as future directions for this work.

  18. The energy stabilization for the SLC scavenger beam

    International Nuclear Information System (INIS)

    Hsu, I.; Browne, M.; Himel, T.; Humphrey, R.; Jobe, K.; Ross, M.; Pellegrin, J.L.; Seeman, J.

    1991-01-01

    The energy of the SLC scavenger beam which is used to produce positrons must be carefully maintained so that the beam can be transported through the collimators in the dispersive region of the extraction line which leads from the Linac to the positron target. A feedforward control loop has been developed to compensate the energy fluctuations due to the beam intensity fluctuations. The loop detects the beam intensities in the damping rings and then calculates how much energy needs to be compensated due to beam loading effects. The energy is corrected by adjusting the acceleration phases of two sets of klystrons right before the extraction. Because there is feedback loop using the same controls, their interaction needs to be carefully treated. This paper presents an overview of the feedforward algorithms

  19. The energy stabilization for the SLC scavenger beam

    International Nuclear Information System (INIS)

    Hsu, Ian; Browne, M.; Himel, T.; Humphrey, R.; Jobe, K.; Ross, M.; Pellegrin, J.L.; Seeman, J.

    1990-08-01

    The energy of the SLC scavenger beam which is used to produce positrons must be carefully maintained so that the beam can be transported through the collimators in the dispersive region of the extraction line which leads from the Linac to the positron target. A feedforward control loop has been developed to compensate the energy fluctuations due to the beam intensity fluctuations. The loop detects the beam intensities in the damping rings and then calculates how much energy needs to be compensated due to beam loading effects. The energy is corrected by adjusting the acceleration phases of two sets of klystrons right before the extraction. Because there is feedback loop using the same controls, their interaction needs to be carefully treated. This paper presents an overview of the feedforward algorithms. 3 figs

  20. Scavenger Receptor Structure and Function in Health and Disease

    Directory of Open Access Journals (Sweden)

    Izma Abdul Zani

    2015-05-01

    Full Text Available Scavenger receptors (SRs are a ‘superfamily’ of membrane-bound receptors that were initially thought to bind and internalize modified low-density lipoprotein (LDL, though it is currently known to bind to a variety of ligands including endogenous proteins and pathogens. New family of SRs and their properties have been identified in recent years, and have now been classified into 10 eukaryote families, defined as Classes A-J. These receptors are classified according to their sequences, although in each class they are further classified based in the variations of the sequence. Their ability to bind a range of ligands is reflected on the biological functions such as clearance of modified lipoproteins and pathogens. SR members regulate pathophysiological states including atherosclerosis, pathogen infections, immune surveillance, and cancer. Here, we review our current understanding of SR structure and function implicated in health and disease.

  1. Flavonoids: hemisynthesis, reactivity, characterization and free radical scavenging activity.

    Science.gov (United States)

    Es-Safi, Nour-Eddine; Ghidouche, Souhila; Ducrot, Paul Henri

    2007-09-26

    Phenolic compounds form one of the main classes of secondary metabolites. They display a large range of structures and they are responsible for the major organoleptic characteristics of plant-derived-foods and beverages, particularly color and taste properties and they also contribute to the nutritional qualities of fruits and vegetables. Phenolic compounds are also highly unstable compounds which undergo numerous enzymatic and chemical reactions during postharvest food storage and processing thus adding to the complexity of plant polyphenol composition. Among these compounds flavonoids constitute one of the most ubiquitous groups of all plant phenolics. Owing to their importance in food organoleptic properties and in human health, a better understanding of their structures, their reactivity and chemical properties in addition to the mechanisms generating them appears essential to predict and control food quality. The purpose of this work is an overview of our findings concerning the hemisynthesis, the reactivity and the enzymatic oxidation of some flavonoids and shed light on the mechanisms involved in some of these processes and the structures of the resulting products. The free radical scavenging activity of some of the synthesized compounds is also presented and a structure-activity relationship is discussed. The first part of this review concerns the synthesis and structural characterization of modified monomeric flavanols. The use of these compounds as precursor for the preparation of natural and modified dimeric procyanidin derivatives was then explored through different coupling reactions. The full characterization of the synthesized compounds was achieved by concerted use of NMR and ESI-MS techniques. The free radical scavenging activity of some of the synthesized compounds was investigated. The second part of this review concerns the enzymatic oxidation of several flavonols by Trametes versicolor laccase. Most of the major oxidation products have been

  2. Flavonoids: Hemisynthesis, Reactivity, Characterization and Free Radical Scavenging Activity

    Directory of Open Access Journals (Sweden)

    Paul Henri Ducrot

    2007-09-01

    Full Text Available Phenolic compounds form one of the main classes of secondary metabolites. They display a large range of structures and they are responsible for the major organoleptic characteristics of plant-derived-foods and beverages, particularly color and taste properties and they also contribute to the nutritional qualities of fruits and vegetables. Phenolic compounds are also highly unstable compounds which undergo numerous enzymatic and chemical reactions during postharvest food storage and processing thus adding to the complexity of plant polyphenol composition. Among these compounds flavonoids constitute one of the most ubiquitous groups of all plant phenolics. Owing to their importance in food organoleptic properties and in human health, a better understanding of their structures, their reactivity and chemical properties in addition to the mechanisms generating them appears essential to predict and control food quality. The purpose of this work is an overview of our findings concerning the hemisynthesis, the reactivity and the enzymatic oxidation of some flavonoids and shed light on the mechanisms involved in some of these processes and the structures of the resulting products. The free radical scavenging activity of some of the synthesized compounds is also presented and a structure-activity relationship is discussed. The first part of this review concerns the synthesis and structural characterization of modified monomeric flavanols. The use of these compounds as precursor for the preparation of natural and modified dimeric procyanidin derivatives was then explored through different coupling reactions. The full characterization of the synthesized compounds was achieved by concerted use of NMR and ESI-MS techniques. The free radical scavenging activity of some of the synthesized compounds was investigated. The second part of this review concerns the enzymatic oxidation of several flavonols by Trametes versicolor laccase. Most of the major oxidation

  3. Molecular Mechanisms behind Free Radical Scavengers Function against Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Fereshteh Ahmadinejad

    2017-07-01

    Full Text Available Accumulating evidence shows that oxidative stress is involved in a wide variety of human diseases: rheumatoid arthritis, Alzheimer’s disease, Parkinson’s disease, cancers, etc. Here, we discuss the significance of oxidative conditions in different disease, with the focus on neurodegenerative disease including Parkinson’s disease, which is mainly caused by oxidative stress. Reactive oxygen and nitrogen species (ROS and RNS, respectively, collectively known as RONS, are produced by cellular enzymes such as myeloperoxidase, NADPH-oxidase (nicotinamide adenine dinucleotide phosphate-oxidase and nitric oxide synthase (NOS. Natural antioxidant systems are categorized into enzymatic and non-enzymatic antioxidant groups. The former includes a number of enzymes such as catalase and glutathione peroxidase, while the latter contains a number of antioxidants acquired from dietary sources including vitamin C, carotenoids, flavonoids and polyphenols. There are also scavengers used for therapeutic purposes, such as 3,4-dihydroxyphenylalanine (L-DOPA used routinely in the treatment of Parkinson’s disease (not as a free radical scavenger, and 3-methyl-1-phenyl-2-pyrazolin-5-one (Edaravone that acts as a free radical detoxifier frequently used in acute ischemic stroke. The cell surviving properties of L-DOPA and Edaravone against oxidative stress conditions rely on the alteration of a number of stress proteins such as Annexin A1, Peroxiredoxin-6 and PARK7/DJ-1 (Parkinson disease protein 7, also known as Protein deglycase DJ-1. Although they share the targets in reversing the cytotoxic effects of H2O2, they seem to have distinct mechanism of function. Exposure to L-DOPA may result in hypoxia condition and further induction of ORP150 (150-kDa oxygen-regulated protein with its concomitant cytoprotective effects but Edaravone seems to protect cells via direct induction of Peroxiredoxin-2 and inhibition of apoptosis.

  4. Study of atmospheric pollution scavenging. Seventeenth progress report

    Energy Technology Data Exchange (ETDEWEB)

    Semonin, R.G.; Bartlett, J.; Gatz, D.F.; Peden, M.E.; Skowron, L.M.; Stensland, G.J.

    1979-07-01

    The continued study of historical precipitation chemistry, air quality, and emissions data shows that the nitrate concentrations in precipitation have increased over the past 20 years with little change in sulfate concentrations. An analysis of aerosol concentrations at MAP3S precipitation collection sites shows consistently higher elemental concentrations at urban Champaign, Illinois, than sites at Whiteface Mountain, New York, and rural Champaign. Scavenging ratios at Whiteface exceeded those obtained previously at St. Louis, Missouri, possibly due to mid-tropospheric long-range transport and differing synoptic situations. Factor analysis of 6 storms during METROMEX shows that different deposition patterns were found for the soluble and insoluble concentrations of the same element. This suggests different scavenging processes may be active for these fractions. Using METROMEX data, no correlation was found between pollutant source strength and the urban-related precipitation anomaly. Four different Nuclepore air filter setups were used to compare air concentrations of sulfate, nitrate, and ammonium. The sulfate comparison was good, but the large variability for nitrate and ammonium raise serious questions on the credibility of measurements using Nuclepore as the collection medium. The details of a case study of wet deposition from SCORE-78 are presented and shows the pollutant concentrations are more variable than the rainfall. A brief description of the progress on the SCORE-79 project is presented. The progress on acid rainfall studies shows that the high pH values in the Midwest in the mid-1950's were due in part to elevated concentrations of calcium and magnesium. A variety of model calculations are presented to show the effects of adjusting past data to currently observed values. Recent results of continuing research on ionic stability of precipitation samples are given.

  5. Scavenging Iron: A Novel Mechanism of Plant Immunity Activation by Microbial Siderophores1[C][W

    Science.gov (United States)

    Aznar, Aude; Chen, Nicolas W.G.; Rigault, Martine; Riache, Nassima; Joseph, Delphine; Desmaële, Didier; Mouille, Grégory; Boutet, Stéphanie; Soubigou-Taconnat, Ludivine; Renou, Jean-Pierre; Thomine, Sébastien; Expert, Dominique; Dellagi, Alia

    2014-01-01

    Siderophores are specific ferric iron chelators synthesized by virtually all microorganisms in response to iron deficiency. We have previously shown that they promote infection by the phytopathogenic enterobacteria Dickeya dadantii and Erwinia amylovora. Siderophores also have the ability to activate plant immunity. We have used complete Arabidopsis transcriptome microarrays to investigate the global transcriptional modifications in roots and leaves of Arabidopsis (Arabidopsis thaliana) plants after leaf treatment with the siderophore deferrioxamine (DFO). Physiological relevance of these transcriptional modifications was validated experimentally. Immunity and heavy-metal homeostasis were the major processes affected by DFO. These two physiological responses could be activated by a synthetic iron chelator ethylenediamine-di(o-hydroxyphenylacetic) acid, indicating that siderophores eliciting activities rely on their strong iron-chelating capacity. DFO was able to protect Arabidopsis against the pathogenic bacterium Pseudomonas syringae pv tomato DC3000. Siderophore treatment caused local modifications of iron distribution in leaf cells visible by ferrocyanide and diaminobenzidine-H2O2 staining. Metal quantifications showed that DFO causes a transient iron and zinc uptake at the root level, which is presumably mediated by the metal transporter iron regulated transporter1 (IRT1). Defense gene expression and callose deposition in response to DFO were compromised in an irt1 mutant. Consistently, plant susceptibility to D. dadantii was increased in the irt1 mutant. Our work shows that iron scavenging is a unique mechanism of immunity activation in plants. It highlights the strong relationship between heavy-metal homeostasis and immunity. PMID:24501001

  6. Scavenging behaviour of meranti sawdust in the removal of methylene blue from aqueous solution

    International Nuclear Information System (INIS)

    Ahmad, A.; Rafatullah, M.; Sulaiman, O.; Ibrahim, M.H.; Hashim, R.

    2009-01-01

    Meranti (Philippine mahogany) sawdust, an inexpensive material, showed strong scavenging behaviour through adsorption for the removal of methylene blue (MB) from aqueous solution. Batch studies were performed to evaluate and optimize the effects of various parameters such as contact time, pH, initial dye concentrations and adsorbent dosage. Langmuir, Freundlich and Temkin isotherms were used to analyze the equilibrium data at different temperatures. The experimental data fitted well with the Langmuir adsorption isotherm, indicating thereby the mono layer adsorption of the dye. The monolayer sorption capacity of meranti sawdust for MB was found to be 120.48, 117.64, 149.25 and 158.73 mg/g at 30, 40, 50 and 60 deg. C, respectively. Thermodynamic calculations showed that the MB adsorption process is endothermic and spontaneous in nature. Kinetic studies showed that the adsorption followed a pseudo-second-order kinetic model. The results indicated that the meranti sawdust could be an alternative material in place of more costly adsorbents used for dye removal.

  7. Influence of various scavengers of •OH radicals on the radiation sensitivity of yeast and bacteria.

    Science.gov (United States)

    Múčka, Viliam; Bláha, Pavel; Čuba, Václav; Červenák, Jaroslav

    2013-12-01

    To quantitatively investigate the influence of various •OH (hydroxyl radical) scavengers on the radiation sensitivity of yeast and bacteria, particularly to define the relationship between the protective effect of a scavenger and its •OH scavenging efficiency. In order to study the protective effect of •OH scavengers we used various concentrations of four scavengers (methanol, potassium formate, ethanol and ascorbic acid) in isotonic salt solutions. These solutions containing live yeast (Saccharomyces cerevisiae) or bacteria (Escherichia coli) were irradiated with (60)Co isotope γ -radiation using two different doses and dose rates. The number of surviving cells was determined prior to and after irradiation both in suspension with and without scavengers. The surviving fractions after irradiation with and without the scavenger were evaluated. The main results of the paper were: The surviving fraction increased approximately linearly within the measured interval with increasing concentration of the scavenger. The same dependences were found for the protecting effect depending on the scavenging efficiency. The slopes of these dependences (k) were found to be characteristic for each scavenger. The k value determined the degree in which the scavenging of •OH radicals participated in the protection of living cells. The protective effects of scavengers at the same scavenging efficiency were different and unique for each scavenger. No simple relation was found between the efficiency of scavenger k and the rate constant kOH of the reactions between scavengers and •OH radicals. Our results suggest that the studied scavengers effectively protected yeast and bacteria against ionizing radiation. Although the scavenging of •OH radicals seems to be important for protection of living cells, it is clearly not the only process on which the protection is based.

  8. Thermal Behavior and Free-Radical-Scavenging Activity of Phytic Acid Alone and Incorporated in Cosmetic Emulsions

    Directory of Open Access Journals (Sweden)

    André Luis Máximo Daneluti

    2015-07-01

    Full Text Available Phytic acid is a natural compound widely used as depigmenting agent in cosmetic emulsions. Few studies are available in the literature covering the stability and the antioxidating property of this substance, used alone or into emulsions. Therefore, the purpose of this work was to investigate the thermal behavior and antioxidant properties of phytic acid alone and into cosmetic emulsions. The thermal behavior of this substance was evaluated by thermogravimetry (TG/derivative thermogravimetry (DTG and differential scanning calorimetry (DSC and the free-radical-scavenging activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH. TG/DTG and DSC curves allowed evaluation of the thermal behavior of phytic acid. These results showed that the substance presented four stages of mass loss. Thermal decomposition of the material initiated at 150 °C. Thermal behavior of the cosmetic emulsions detected that the addition of phytic acid decreased the thermal stability of the system. DPPH free-radical-scavenging activity showed that phytic acid incorporated into emulsion had no antioxidant capacity compared to BHT. In summary, we concluded that the thermoanalytical techniques (TG and DSC were efficient and reliable in the characterization of phytic acid alone and incorporated into cosmetic emulsions.

  9. Prooxidant/Antioxidant Ratio (ProAntidex as a Better Index of Net Free Radical Scavenging Potential

    Directory of Open Access Journals (Sweden)

    Hwee Ming Cheng

    2010-11-01

    Full Text Available The antioxidant activity of several Malaysian plant extracts was analyzed simultaneously with their pro-oxidant capacity. This ratio represents an index (ProAntidex of the net free radical scavenging ability of whole plant extracts. We observed that ethanolic extracts of Nephelium lappaceum peel, Fragaria x ananassa leaf, Lawsonia inermis leaf, Syzygium aqueum leaf and grape seed had a lower Pro-Antidex than the commercially available Emblica™ extract which is an antioxidant agent with very low pro-oxidant activity. Among the aqueous extracts, Lawsonia inermis leaf, Nephelium mutobile leaf and grape seed had lower pro-oxidant activity compared to the Emblica™ extract. Among these extracts, aqueous extract of Nephelium mutobile leaf had a very low index of 0.05 compared to 0.69 for Emblica™. Most of the extracts had a far lower ProAntidex compared to the Vitamin C. The index enables us to identify extracts with high net free radical scavenging activity potential. The ProAntidex is beneficial as a screening parameter to the food industries and healthcare.

  10. Preparation of Orthosiphon stamineus enriched-extracts and evaluation of their free radical scavenging activity

    Science.gov (United States)

    Mansor, Che Nurul Ain Nadirah Che; Latip, Jalifah; Markom, Masturah

    2016-11-01

    Orthosiphon stamineus is one of the important herbal plants used in folk medicine to cure variety of diseases. Three compounds namely rosmarinic acid (RA), sinensetin (SEN) and eupatorin (EUP) were identified as the bioactive markers. However, a standardized extraction method for the preparation of O. stamineus extract enriched with the bioactive compounds was still undiscovered. Thus, this study aims to establish the optimal extraction method that can be used to prepare the enriched extract with anti-oxidant property. Maceration, reflux and Soxhlet were the extraction methods employed, with ethanol, 50% (v/v) aqueous ethanol and water were chosen as the solvents. Each extracts were evaluated for their biomarker contents (RA, SEN and EUP) and anti-oxidant capacity using thin layer chromatography (TLC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay respectively. Among the three extraction methods employed, the highest total extraction yield was obtained from reflux (72.73%) followed by Soxhlet (62.51%) and maceration (37.78%). Although all extracts found to contain the three biomarkers via TLC visualization analysis, there was variation in the extracts' anti-oxidant capacity, ranging from 6.17% to 72.97%. The variation was expected to be due to the difference in the quantity of the biomarkers in each extract. Furthermore, the anti-oxidative potency of the RA was found comparable to natural anti-oxidant vitamin C, and higher than the synthetic anti-oxidant butylated hydroxyl toluene (BHT). These preliminary results may serve as a starting point towards the preparation of standardized bioactive O. stamineus extract.

  11. How Predictability of Feeding Patches Affects Home Range and Foraging Habitat Selection in Avian Social Scavengers?

    NARCIS (Netherlands)

    Monsarrat, S.; Benhamou, S.; Sarrazin, F.; Bessa-Gomes, C.; Bouten, W.; Duriez, O.

    2013-01-01

    Feeding stations are commonly used to sustain conservation programs of scavengers but their impact on behaviour is still debated. They increase the temporal and spatial predictability of food resources while scavengers have supposedly evolved to search for unpredictable resources. In the Grands

  12. Identification, characterisation and composition of scavengeable feed resources for rural poultry production in Central Tanzania

    NARCIS (Netherlands)

    Goromela, E.H.; Kwakkel, R.P.; Verstegen, M.W.A.; Katule, A.M.

    2007-01-01

    A participatory study was carried out in four villages of central Tanzania to appraise existing and potential scavengeable feed resources available for rural poultry. In addition, proximate analysis of selected scavengeable feed resources including chicken crop and gizzards contents was carried out

  13. Predatory blue crabs induce stronger nonconsumptive effects in eastern oysters Crassostrea virginica than scavenging blue crabs

    Directory of Open Access Journals (Sweden)

    Avery E. Scherer

    2017-02-01

    Full Text Available By influencing critical prey traits such as foraging or habitat selection, predators can affect entire ecosystems, but the nature of cues that trigger prey reactions to predators are not well understood. Predators may scavenge to supplement their energetic needs and scavenging frequency may vary among individuals within a species due to preferences and prey availability. Yet prey reactions to consumers that are primarily scavengers versus those that are active foragers have not been investigated, even though variation in prey reactions to scavengers or predators might influence cascading nonconsumptive effects in food webs. Oysters Crassostrea virginica react to crab predators by growing stronger shells. We exposed oysters to exudates from crabs fed live oysters or fed aged oyster tissue to simulate scavenging, and to controls without crab cues. Oysters grew stronger shells when exposed to either crab exudate, but their shells were significantly stronger when crabs were fed live oysters. The stronger response to predators than scavengers could be due to inherent differences in diet cues representative of reduced risk in the presence of scavengers or to degradation of conspecific alarm cues in aged treatments, which may mask risk from potential predators subsisting by scavenging.

  14. New actualistic data on the ecology and energetics of hominin scavenging opportunities.

    Science.gov (United States)

    Pobiner, Briana L

    2015-03-01

    For decades, the 'hunting-scavenging debate' has been an important research focus in Plio-Pleistocene hominin behavioral ecology. Here I present new data on potential scavenging opportunities from fresh carnivore kills on a conservancy in central Kenya. This ecosystem is dominated by felids (mainly lions) and has a different carnivore guild than in many earlier studies of scavenging opportunities that took place in areas such as Ngorongoro and Serengeti in Tanzania and Maasai Mara in Kenya, where lions face high levels of inter-specific competition from bone-crunching hyenas. I found that while scavenging opportunities vary among carcasses, most carcasses retained some scavengeable resources. Excluding within-bone resources, even the scavengeable meat on 'defleshed' larger sized prey carcasses is usually substantial enough to meet the total daily caloric requirements of at least one adult male Homo erectus individual. I argue, as others have before me, that scavenging opportunities in a particular ecosystem will vary in part due to carnivore taxon, density and guild composition; prey size, biomass and community structure; and habitat (e.g., vegetation, physiography). We should expect variability in scavenging opportunities in different locales and should focus our research efforts on identifying which variables condition these differences in order to make our findings applicable to the diversity of ecological settings characterizing the past. Published by Elsevier Ltd.

  15. Optimum injection dose rate of hydrogen sulfide scavenger for treatment of petroleum crude oil

    Directory of Open Access Journals (Sweden)

    T.M. Elshiekh

    2016-03-01

    Full Text Available Hydrogen sulfide H2S scavengers are chemicals that favorably react with hydrogen sulfide gas to eliminate it and produce environmental friendly products. These products depend on the type and composition of the scavenger and the conditions at which the reaction takes place. The scavenger should be widely available and economical for industry acceptance by having a low unit cost. The optimum values of H2S scavenger injection dose rate of scavenging hydrogen sulfide from the multiphase fluid produced at different wells conditions in one of the Petroleum Companies in Egypt were studied. The optimum values of H2S scavenger injection dose rate depend on pipe diameter, pipe length, gas molar mass velocity, inlet H2S concentration and pressure. The optimization results are obtained for different values of these parameters using the software program Lingo. In general, the optimum values of H2S scavenger injection dose rate of the scavenging of hydrogen sulfide are increased by increasing of the pipe diameter and increasing the inlet H2S concentration, and decreased by increasing the pipe length, gas molar mass velocity and pressure.

  16. Identification of Radical Scavenging Compounds in Rhaponticum carthamoides by Means of LC-DAD-SPE-NMR

    NARCIS (Netherlands)

    Miliauskas, G.; Beek, van T.A.; Waard, de P.; Venskutonis, R.P.; Sudhölter, E.J.R.

    2005-01-01

    A hyphenated LC-DAD-SPE-NMR setup in combination with on-line radical scavenging detection has been applied for the identification of radical scavenging compounds in extracts of Rhaponticum carthamoides. After NMR measurements, the pure compounds were infused into a mass spectrometer. The technique

  17. Isolation and Structure Elucidation of Radical Scavengers from Thymus vulgaris Leaves

    NARCIS (Netherlands)

    Dapkevicius, A.; Beek, van T.A.; Lelyveld, G.P.; Veldhuizen, van A.; Groot, de Æ.; Linssen, J.P.H.; Venskutonis, R.

    2002-01-01

    2,2-Diphenyl-1-picrylhydrazyl radical (DPPH*) scavenging activity-guided fractionation of a leaf extract of Thymus vulgaris led to the isolation of the radical scavengers rosmarinic acid 1, eriodictyol, taxifolin, luteolin 7-glucuronide, p-cymene 2,3-diol, p-cymene 2,3-diol 6-6'-dimer, carvacrol,

  18. Apoptotic and free radical scavenging properties of the methanolic extract of Gentianella alborosea.

    Science.gov (United States)

    Acero, Nuria; Llinares, Francisco; Galán de Mera, Antonio; Oltra, Beatriz; Muñoz-Mingarro, Dolores

    2006-09-01

    Gentianella alborosea ("Hercampure") is a Peruvian species used in folk medicine for the treatment of a variety of health disorders. We tested the free radical scavenging (DPPH) and induction of apoptosis on a human uterus tumor cell line (HeLa) by its methanolic extract. The results showed a noticeable radical scavenging activity and a dose-dependent apoptotic effect.

  19. A method for nitric oxide radical scavenging properties of sulfur containing compounds.

    NARCIS (Netherlands)

    Vriesman, M.F.; Haenen, G.R.M.M.; Westerveld, G.J.; Paquay, J.B.G.; Voss, H.P.; Bast, A.

    1997-01-01

    A new method for the quantification of the nitric oxide (NO) scavenging activity of compounds in aqueous solutions is described using an amperometric NO sensor. After correction for the spontaneous degradation of NO, second-order rate kinetics of the scavenging reaction are observed.

  20. Comparative investigation of the free radical scavenging potential and anticancer property of Diospyros blancoi (Ebenaceae

    Directory of Open Access Journals (Sweden)

    Muhammad Ali Khan

    2016-05-01

    Conclusions: Our results indicate that Diospyros blancoi stem bark had the significant highest antioxidant and free radical scavenging properties as well as moderate anticancer activity. Hence, we assume that the anticancer activity of this plant can be, at least in part, attributed to its content in phenolic compounds as well as its significant free radical scavenging properties.

  1. Synthesis and Evaluation of the Anti-Oxidant Capacity of Curcumin Glucuronides, the Major Curcumin Metabolites

    OpenAIRE

    Choudhury, Ambar K.; Raja, Suganya; Mahapatra, Sanjata; Nagabhushanam, Kalyanam; Majeed, Muhammed

    2015-01-01

    Curcumin metabolites namely curcumin monoglucuronide and curcumin diglucuronide were synthesized using an alternative synthetic approach. The anti-oxidant potential of these curcumin glucuronides was compared with that of curcumin using DPPH scavenging method and Oxygen Radical Absorbance Capacity (ORAC) assay. The results show that curcumin monoglucuronide exhibits 10 fold less anti-oxidant activity (DPPH method) and the anti-oxidant capacity of curcumin diglucuronide is highly attenuated co...

  2. Fatal embryo chondral damage associated with fluoroquinolones in eggs of threatened avian scavengers

    International Nuclear Information System (INIS)

    Lemus, J.A.; Blanco, G.; Arroyo, B.; Martinez, F.; Grande, J.

    2009-01-01

    Stabled livestock reared in housed conditions are often subjected to intensive treatments with veterinary drug, which residues may be present in livestock meat ingested by scavengers, but nothing is known about their presence in eggs of wild birds and their potential detrimental effects on breeding success. We searched for residues of veterinary drugs and other toxicants in infertile and embryonated unhatched eggs of griffon vultures (Gyps fulvus) and red kites (Milvus milvus), two threatened avian scavengers. Quinolones (ciprofloxacin and enrofloxacin) were found in most unhatched eggs of both scavenger species clearly associated with severe alterations in the development of embryo cartilage and bones that could preclude embryo movements and subsequently normal development, pre-hatch position and successful hatching. The detrimental effects on developing eggs of veterinary drugs from livestock operations may help to explain reduced breeding success of avian scavengers. - Fluoroquinolones used in livestock farming and found in eggs of avian scavenger caused severe alterations in embryo cartilage and bone development.

  3. Fatal embryo chondral damage associated with fluoroquinolones in eggs of threatened avian scavengers

    Energy Technology Data Exchange (ETDEWEB)

    Lemus, J.A. [Departamento de Ecologia Evolutiva, Museo Nacional de Ciencias Naturales (CSIC), J. Gutierrez Abascal 2, 28006 Madrid (Spain); Blanco, G., E-mail: gublanco2@yahoo.e [Departamento de Ecologia Evolutiva, Museo Nacional de Ciencias Naturales (CSIC), J. Gutierrez Abascal 2, 28006 Madrid (Spain); Arroyo, B.; Martinez, F.; Grande, J. [Departamento de Ecologia Evolutiva, Museo Nacional de Ciencias Naturales (CSIC), J. Gutierrez Abascal 2, 28006 Madrid (Spain)

    2009-08-15

    Stabled livestock reared in housed conditions are often subjected to intensive treatments with veterinary drug, which residues may be present in livestock meat ingested by scavengers, but nothing is known about their presence in eggs of wild birds and their potential detrimental effects on breeding success. We searched for residues of veterinary drugs and other toxicants in infertile and embryonated unhatched eggs of griffon vultures (Gyps fulvus) and red kites (Milvus milvus), two threatened avian scavengers. Quinolones (ciprofloxacin and enrofloxacin) were found in most unhatched eggs of both scavenger species clearly associated with severe alterations in the development of embryo cartilage and bones that could preclude embryo movements and subsequently normal development, pre-hatch position and successful hatching. The detrimental effects on developing eggs of veterinary drugs from livestock operations may help to explain reduced breeding success of avian scavengers. - Fluoroquinolones used in livestock farming and found in eggs of avian scavenger caused severe alterations in embryo cartilage and bone development.

  4. Accumulation of primary and secondary metabolites in edible jackfruit seed tissues and scavenging of reactive nitrogen species.

    Science.gov (United States)

    Fernandes, Fátima; Ferreres, Federico; Gil-Izquierdo, Angel; Oliveira, Andreia P; Valentão, Patrícia; Andrade, Paula B

    2017-10-15

    Studies involving jackfruit tree (Artocarpus heterophyllus Lam.) focus on its fruit. Nevertheless a considerable part of jackfruit weight is represented by its seeds. Despite being consumed in several countries, knowledge about the chemical composition of these seeds is scarce. In this work, the accumulation of primary and secondary metabolites in jackfruit seed kernel and seed coating membrane was studied. Sixty-seven compounds were identified, sixty of them being reported for the first time in jackfruit seed. Both tissues had a similar qualitative profile, but significant quantitative differences were found. The capacity of aqueous extracts from jackfruit seed kernel and seed coating membranes to scavenge nitric oxide radical was also evaluated for the first time, the extract prepared from the seed coating membrane being the most potent. This work increases the potential revenue from a food that is still largely wasted. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Radical Scavenging by Acetone: A New Perspective to Understand Laccase/ABTS Inactivation and to Recover Redox Mediator.

    Science.gov (United States)

    Liu, Hao; Zhou, Pandeng; Wu, Xing; Sun, Jianliang; Chen, Shicheng

    2015-11-04

    The biosynthetic utilization of laccase/mediator system is problematic because the use of organic cosolvent causes significant inhibition of laccase activity. This work explored how the organic cosolvent impacts on the laccase catalytic capacity towards 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) in aqueous solution. Effects of acetone on the kinetic constants of laccase were determined and the results showed Km and Vmax varied exponentially with increasing acetone content. Acetone as well as some other cosolvents could transform ABTS radicals into its reductive form. The content of acetone in media significantly affected the radical scavenging rates. Up to 95% of the oxidized ABTS was successfully recovered in 80% (v/v) acetone in 60 min. This allows ABTS recycles at least six times with 70%-75% of active radicals recovered after each cycle. This solvent-based recovery strategy may help improve the economic feasibility of laccase/ABTS system in biosynthesis.

  6. Different Reactive Oxygen Species Scavenging Properties of Flavonoids Determine Their Abilities to Extend the Shelf Life of Tomato1[OPEN

    Science.gov (United States)

    Zhang, Yang; De Stefano, Rosalba; Robine, Marie; Butelli, Eugenio; Bulling, Katharina; Hill, Lionel; Rejzek, Martin; Martin, Cathie; Schoonbeek, Henk-jan

    2015-01-01

    The shelf life of tomato (Solanum lycopersicum) fruit is determined by the processes of overripening and susceptibility to pathogens. Postharvest shelf life is one of the most important traits for commercially grown tomatoes. We compared the shelf life of tomato fruit that accumulate different flavonoids and found that delayed overripening is associated with increased total antioxidant capacity caused by the accumulation of flavonoids in the fruit. However, reduced susceptibility to Botrytis cinerea, a major postharvest fungal pathogen of tomato, is conferred by specific flavonoids only. We demonstrate an association between flavonoid structure, selective scavenging ability for different free radicals, and reduced susceptibility to B. cinerea. Our study provides mechanistic insight into how flavonoids influence the shelf life, information that could be used to improve the shelf life of tomato and, potentially, other soft fruit. PMID:26082399

  7. Different Reactive Oxygen Species Scavenging Properties of Flavonoids Determine Their Abilities to Extend the Shelf Life of Tomato.

    Science.gov (United States)

    Zhang, Yang; De Stefano, Rosalba; Robine, Marie; Butelli, Eugenio; Bulling, Katharina; Hill, Lionel; Rejzek, Martin; Martin, Cathie; Schoonbeek, Henk-jan

    2015-11-01

    The shelf life of tomato (Solanum lycopersicum) fruit is determined by the processes of overripening and susceptibility to pathogens. Postharvest shelf life is one of the most important traits for commercially grown tomatoes. We compared the shelf life of tomato fruit that accumulate different flavonoids and found that delayed overripening is associated with increased total antioxidant capacity caused by the accumulation of flavonoids in the fruit. However, reduced susceptibility to Botrytis cinerea, a major postharvest fungal pathogen of tomato, is conferred by specific flavonoids only. We demonstrate an association between flavonoid structure, selective scavenging ability for different free radicals, and reduced susceptibility to B. cinerea. Our study provides mechanistic insight into how flavonoids influence the shelf life, information that could be used to improve the shelf life of tomato and, potentially, other soft fruit. © 2015 American Society of Plant Biologists. All Rights Reserved.

  8. The natural food colorant Peonidin from cranberries as a potential radical scavenger - A DFT based mechanistic analysis.

    Science.gov (United States)

    Rajan, Vijisha K; Hasna, C K; Muraleedharan, K

    2018-10-01

    A theoretical evaluation of the antioxidant property of a natural food colorant Peonidin has been performed. The most suitable mechanism for explaining the radical scavenging capacity of Peonidin is the Hydrogen Atom Transfer and the most active site for radical formation is position 3 and is confirmed through Mulliken charge analysis, pKa value evaluation, Bond Dissociation Energy values, and Natural Bond Orbital analysis. Position 3 and 5 in Peonidin exists in blood as deprotonated as their pKa values are lower than the pH of blood. Peonidin is highly reactive than Quercetin and less stable than flavan-3-ols due to the small band gap. Global descriptor analysis shows that PN prefers to accept electrons than to donate. The effect of number of OH groups and the nature of substituents are well explained through this work. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. The scavenger receptor SSc5D physically interacts with bacteria through the SRCR-containing N-terminal domain

    Directory of Open Access Journals (Sweden)

    Catarina Bessa-Pereira

    2016-10-01

    Full Text Available The scavenger receptor cysteine-rich (SRCR family comprises a group of membrane-attached or secreted proteins that contain one or more modules/domains structurally similar to the membrane distal domain of type I macrophage scavenger receptor. Although no all-inclusive biological function has been ascribed to the SRCR family, some of these receptors have been shown to recognize pathogen-associated molecular patterns (PAMP of bacteria, fungi or other microbes. SSc5D is a recently described soluble SRCR receptor produced by monocytes/macrophages and T lymphocytes, consisting of an N-terminal portion which contains five SRCR modules, and a large C-terminal mucin-like domain. Towards establishing a global common role for SRCR domains, we interrogated whether the set of five SRCR domains of SSc5D displayed pattern recognition receptor (PRR properties. For that purpose, we have expressed in a mammalian expression system the N-terminal SRCR-containing moiety of SSC5D (N-SSc5D, thus excluding the mucin-like domain likely by nature to bind microorganisms, and tested the capacity of the SRCR functional groups to physically interact with bacteria. Using conventional protein-bacteria binding assays, we showed that N-SSc5D had a superior capacity to bind to E. coli strains RS218 and IHE3034 compared with that of the extracellular domains of the SRCR proteins CD5 and CD6 (sCD5 and sCD6, respectively, and similar E. coli-binding properties as Spα, a proven PRR of the SRCR family. We have further designed a more sensitive, real-time and label-free surface plasmon resonance (SPR-based assay, and examined the capacity of N-SSc5D, Spα, sCD5 and sCD6 to bind to different bacteria. We demonstrated that the N-SSc5D compares with Spα in the capacity to bind to E. coli and L. monocytogenes, and further that it can distinguish between pathogenic E. coli RS218 and IHE3034 strains and the non-pathogenic laboratory E. coli strain BL21(DE3. Our work thus advocates the

  10. Study of air pollution scavenging. Fourteenth progress report

    Energy Technology Data Exchange (ETDEWEB)

    Semonin, R.G.

    1976-04-01

    The field experiments were continued to estimate convective storm particulate scavenging efficiency in proximity to the St. Louis, Missouri urban-industrial complex. Complementary studies of the urban aerosol characterization, source strength, and removal processes were also studied. The 1975 field effort shifted emphasis from the immediate St. Louis area to the Alton-Wood River industrial complex. Along with the change in size and configuration of the network, there were increases in the numbers of most types of samplers. The new network yielded the following types of samples for analysis and interpretation: 1065 total rain samples from 85 sites; 68 sequential rainwater samples from 2 locations; 272 wet/dry samples from 7 locations; 216 air filter samples from 7 locations; 36 air filter samples from aircraft; and raindrop spectrometer data from 11 sites for the period 17 June-18 August. The analysis procedures require that all water samples undergo filtering for separate analyses of soluble and insoluble fractions of the elemental concentrations. This data collection effort provided a record number of samples for chemical analysis. Approximately 4000 pibals and over 370 radiosondes were released in the operational period, providing wind and thermodynamic data on 33 days. Aircraft missions were flown on 24 days, with one air tracer release of cesium on 19 July 1975. The status of the analysis of all types of data is described.

  11. Microbial fuel cell as a free-radical scavenging tool

    International Nuclear Information System (INIS)

    Koleva, Ralitza; Yemendzhiev, Hyusein; Nenov, Valentin

    2017-01-01

    Microbial fuel cells (MFCs) are known for their capability to directly convert organic substrates into electricity by the biochemical activity of specific microorganisms. Availability of a proper terminal electron acceptor is crucial for this process. Free radicals, with their one or more unpaired electrons, are extremely reducible and could be considered as electron acceptors in terms of cathodic processes in MFC. During this reduction, free radicals could be transformed in the same manner as they are transformed by antioxidants. The present study investigated this opportunity by utilization of 2,2-diphenyl-1-picrylhydrazyl (150 mmol/dm"3 methanol solution) as a free-radical molecule. During the studied process, over 90% radical neutralization was observed in less than 16 hours. The results obtained demonstrate for the first time the potential of MFC type bioelectrochemical systems to serve as a free-radical scavenging tool and to provide antioxidant and anti-radical activity. In this way, this study opens a completely new field of research and application of bio-electrochemical systems

  12. Microfibre-nanowire hybrid structure for energy scavenging.

    Science.gov (United States)

    Qin, Yong; Wang, Xudong; Wang, Zhong Lin

    2008-02-14

    A self-powering nanosystem that harvests its operating energy from the environment is an attractive proposition for sensing, personal electronics and defence technologies. This is in principle feasible for nanodevices owing to their extremely low power consumption. Solar, thermal and mechanical (wind, friction, body movement) energies are common and may be scavenged from the environment, but the type of energy source to be chosen has to be decided on the basis of specific applications. Military sensing/surveillance node placement, for example, may involve difficult-to-reach locations, may need to be hidden, and may be in environments that are dusty, rainy, dark and/or in deep forest. In a moving vehicle or aeroplane, harvesting energy from a rotating tyre or wind blowing on the body is a possible choice to power wireless devices implanted in the surface of the vehicle. Nanowire nanogenerators built on hard substrates were demonstrated for harvesting local mechanical energy produced by high-frequency ultrasonic waves. To harvest the energy from vibration or disturbance originating from footsteps, heartbeats, ambient noise and air flow, it is important to explore innovative technologies that work at low frequencies (such as wind energy and body-movement energy using fabrics.

  13. Postmortem Scavenging of Human Remains by Domestic Cats

    Directory of Open Access Journals (Sweden)

    Ananya Suntirukpong, M.D.

    2017-11-01

    Full Text Available Objective: Crime scene investigators, forensic medicine doctors and pathologists, and forensic anthropologists frequently encounter postmortem scavenging of human remains by household pets. Case presentation: The authors present a case report of a partially skeletonized adult male found dead after more than three months in his apartment in Thailand. The body was in an advanced stage of decomposition with nearly complete skeletonization of the head, neck, hands, and feet. The presence of maggots and necrophagous (flesh eating beetles on the body confirmed that insects had consumed much of the soft tissues. Examination of the hand and foot bones revealed canine tooth puncture marks. Evidence of chewing indicated that one or more of the decedent’s three house cats had fed on the body after death. Recognizing and identifying carnivore and rodent activity on the soft flesh and bones of human remains is important in interpreting and reconstructing postmortem damage. Thorough analysis may help explain why skeletal elements are missing, damaged, or out of anatomical position. Conclusion: This report presents a multi-disciplinary approach combining forensic anthropology and forensic medicine in examining and interpreting human remains.

  14. Solvent optimization extraction of antioxidants from foxtail millet species' insoluble fibers and their free radical scavenging properties.

    Science.gov (United States)

    Bangoura, Mohamed Lamine; Nsor-Atindana, John; Ming, Zhou Hui

    2013-11-15

    In this study, water and 80% of four organic solvents were employed to optimize the extraction of antioxidants from two species of foxtail millet's insoluble fibers under the same temperature, time, and solid/solvent ratio. The results showed that the acetone was able to extract the maximum amount of antioxidants (2.32 mg/g fiber for white specie and 3.86 mg/g fiber for yellow specie) followed by methanol and propanol from both samples. The neutral and the ethanol on the other hand extracted small amount of the antioxidants from the two fiber materials. While considerable level of Total Polyphenols Content (TPC) was recorded in both the water and the organic solvents' extracts, only traces of Total Flavonoid content (TFC) were observed in water, methanol and ethanol extracts. Propanol and acetone extracts was negative to the TFC test. The potency of both white and yellow foxtail millets' insoluble fibers antioxidant extracts was investigated using five different in vitro tests. It was realized that there was a variation in their capacities to quench DPPH and ABTS(+) radicals for the time running of 0-60 min. The samples from the yellow cereal exhibited high inhibition capacity against ABTS(+). No correlation was observed between TPC and radical scavenging capacities for DPPH and ABTS(+). In general, the yellow species contained more antioxidants in comparison with the white one and this accounted for its high antioxidant activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Uric acid contributes greatly to hepatic antioxidant capacity besides protein.

    Science.gov (United States)

    Mikami, T; Sorimachi, M

    2017-12-20

    Uric acid is the end-product of purine nucleotide metabolism and an increase in uric acid concentration in the body results in hyperuricemia, ultimately leading to gout. However, uric acid is a potent antioxidant and interacts with reactive oxygen species (ROS) to be non-enzymatically converted to allantoin. Uric acid accounts for approximately 60 % of antioxidant capacity in the plasma; however, its contribution to tissue antioxidant capacity is unknown. In this study, the contribution of uric acid to tissue antioxidant capacity and its conversion to allantoin by scavenging ROS in tissue were examined. The results showed that a decrease in hepatic uric acid content via allopurinol administration significantly reduced hepatic total-radical trapping antioxidant parameter (TRAP) content in protein-free cytosol. Additionally, treating protein-free cytosol with uricase led to a further reduction of hepatic TRAP content. Allantoin was also detected in the solution containing protein-free cytosol that reacted with ROS. These findings suggest that in the absence of protein, uric acid contributes greatly to antioxidant capacity in the liver, where uric acid is converted to allantoin by scavenging ROS.

  16. Man-Machine Communication in Remote Manipulation: Task-Oriented Supervisory Command Language (TOSC).

    Science.gov (United States)

    1980-03-01

    2-32 WvNIPUa.ATY wWMj.IAYCOYOLLID 𔃾 -XNEMILPU . 310?!3us mI.I Sr 1lR ROBO ........... O4WIUVISYN CP"CRIAumaN OWW411 -femi y PACISS PSTISH ’uucomC...task description 3-15 and as a machine advisor for an apprentice. Thus, the PN are developed hierarchically, by the machine from the top down to the...96734 rs Defense Technical Information Center Dr. A. L. Slafkosky Cameron Station, Bldg. 5 Scientific Advisor Alexandria, VA 22314 (12 cys) Commandant

  17. The Challenge to Scavenge IRON from Tailings Produced By FLOTATION A New Approach: The Super-WHIMS & the BigFLUX Magnetic Matrix

    Directory of Open Access Journals (Sweden)

    José Pancrácio Ribeiro

    Full Text Available Abstract Tailings recovery has been a constant challenge for most engineers. Along more than five years, GAUSTEC joined major players in the mining Industry to scavenge Iron from tailings produced by flotation making use of WHIMS (Wet High Intensity Magnetic Separation. In the early 1980s, in USA, the US 4,192,738 patent was granted with promising results. Despite this, thirty years have passed with no significant application worldwide. One main reason is reported: the market missed a really high feed capacity WHIMS in order to avoid the huge number of the WHIMS that were available at that time (such projects would typically require more than 20 WHIMS to scavenge iron from tailings produced by flotation plants. Such a huge asset to scavenge low grade iron tailings would not payback. The Mega sized WHIMS launched by GAUSTEC in 2014, the GHX-1400, improved by the Super-WHIMS Technology (18.000 Gauss and BigFlow Magnetic Matrixes (Gaps smaller than 1.5 mm, faced this challenge. Specially designed ancillary equipment described here also played a decisive role in the scene.

  18. Assessment of antioxidant activity of cane brown sugars by ABTS and DPPH radical scavenging assays: determination of their polyphenolic and volatile constituents.

    Science.gov (United States)

    Payet, Bertrand; Shum Cheong Sing, Alain; Smadja, Jacqueline

    2005-12-28

    Seven cane brown sugars (four from La Réunion, two from Mauritius, and one from France) were investigated for their polyphenol content and volatile composition in relation to their free radical scavenging capacity determined by ABTS and DPPH assays. The thin layer coated on the sugar crystal was extracted by Soxhlet extractor with dichloromethane. The volatile compounds of brown sugars were studied by GC-MS, and 43 compounds were identified. The total phenolic content of brown sugars was determined according to the Folin-Ciocalteu method. Phenolic compounds were quantified in the brown sugar extracts by LC-UV-ESI-MS. Brown sugar aqueous solutions exhibited weak free radical scavenging activity in the DPPH assay and higher antioxidant activity in the ABTS assay at relatively high concentration. The brown sugar extracts showed interesting free radical scavenging properties despite the low concentration of phenolic and volatile compounds. Sugar is a common foodstuff traditionally used for its sweetening properties, which might be accompanied by antioxidant properties arising from molecules (polyphenols, Maillard products) other than sucrose of the cane brown sugars.

  19. Effects of P25 TiO2 Nanoparticles on the Free Radical-Scavenging Ability of Antioxidants upon Their Exposure to Simulated Sunlight.

    Science.gov (United States)

    Li, Meng; Chong, Yu; Fu, Peter P; Xia, Qingsu; Croley, Timothy R; Lo, Y Martin; Yin, Jun-Jie

    2017-11-15

    Although nanosized ingredients, including TiO 2 nanoparticles (NPs), can be found in a wide range of consumer products, little is known about the effects these particles have on other active compounds in product matrices. These NPs can interact with reactive oxygen species (ROS), potentially disrupting or canceling the benefits expected from antioxidants. We used electron spin resonance spectrometry to assess changes in the antioxidant capacities of six dietary antioxidants (ascorbic acid, α-tocopherol, glutathione, cysteine, epicatechin, and epicatechin gallate) during exposure to P25 TiO 2 and/or simulated sunlight. Specifically, we determined the ability of these antioxidants to scavenge 1-diphenyl-2-picryl-hydrazyl radical, superoxide radical, and hydroxyl radical. Exposure to simulated sunlight alone did not lead to noticeable changes in radical-scavenging abilities; however, in combination with P25 TiO 2 NPs, the scavenging abilities of most antioxidants were weakened. We found glutathione to be the most resistant to treatment with sunlight and NPs among these six antioxidants.

  20. Recovery of Li from alloys of Al- Li and Li- Al using engineered scavenger compounds

    Science.gov (United States)

    Riley, W. D.; Jong, B. W.; Collins, W. K.; Gerdemann, S. J.

    1994-01-01

    A method of producing lithium of high purity from lithium aluminum alloys using an engineered scavenger compound, comprising: I) preparing an engineered scavenger compound by: a) mixing and heating compounds of TiO2 and Li2CO3 at a temperature sufficient to dry the compounds and convert Li.sub.2 CO.sub.3 to Li.sub.2 O; and b) mixing and heating the compounds at a temperature sufficient to produce a scavenger Li.sub.2 O.3TiO.sub.2 compound; II) loading the scavenger into one of two electrode baskets in a three electrode cell reactor and placing an Al-Li alloy in a second electrode basket of the three electrode cell reactor; III) heating the cell to a temperature sufficient to enable a mixture of KCl-LiCl contained in a crucible in the cell to reach its melting point and become a molten bath; IV) immersing the baskets in the bath until an electrical connection is made between the baskets to charge the scavenger compound with Li until there is an initial current and voltage followed by a fall off ending current and voltage; and V) making a connection between the basket electrode containing engineered scavenger compound and a steel rod electrode disposed between the basket electrodes and applying a current to cause Li to leave the scavenger compound and become electrodeposited on the steel rod electrode.

  1. Scavenger Receptors and Their Potential as Therapeutic Targets in the Treatment of Cardiovascular Disease

    Directory of Open Access Journals (Sweden)

    Sam L. Stephen

    2010-01-01

    Full Text Available Scavenger receptors act as membrane-bound and soluble proteins that bind to macromolecular complexes and pathogens. This diverse supergroup of proteins mediates binding to modified lipoprotein particles which regulate the initiation and progression of atherosclerotic plaques. In vascular tissues, scavenger receptors are implicated in regulating intracellular signaling, lipid accumulation, foam cell development, and cellular apoptosis or necrosis linked to the pathophysiology of atherosclerosis. One approach is using gene therapy to modulate scavenger receptor function in atherosclerosis. Ectopic expression of membrane-bound scavenger receptors using viral vectors can modify lipid profiles and reduce the incidence of atherosclerosis. Alternatively, expression of soluble scavenger receptors can also block plaque initiation and progression. Inhibition of scavenger receptor expression using a combined gene therapy and RNA interference strategy also holds promise for long-term therapy. Here we review our current understanding of the gene delivery by viral vectors to cells and tissues in gene therapy strategies and its application to the modulation of scavenger receptor function in atherosclerosis.

  2. Scavenging by spiders (Araneae) and its relationship to pest management of the brown recluse spider.

    Science.gov (United States)

    Vetter, Richard S

    2011-06-01

    Experiments reported in Sandidge (2003; Nature 426: 30) indicated that the brown recluse spider, Loxosceles reclusa Gertsch & Mulaik, preferred to scavenge dead prey over live prey and that the spiders were not detrimentally affected when fed insecticide-killed crickets. Extrapolations made in subsequent media coverage disseminating the results of this research made counter-intuitive statements that pesticide treatment in houses would increase brown recluse populations in homes. This information was presented as if the scavenging behavior was specialized in the brown recluse; however, it was more likely that this behavior has not been well studied in other species. To provide a comparison, the current laboratory study examined the likelihood of non-Loxosceles spiders to scavenge dead prey. Of 100 non-Loxosceles spiders that were tested (from 11 families, 24 genera, and at least 29 species from a variety of spider hunting guilds), 99 scavenged dead crickets when offered in petri dishes. Some of the spiders were webspinners in which real-world scavenging of dead prey is virtually impossible, yet they scavenge when given the opportunity. Therefore, scavenging is a flexible opportunistic predatory behavior that is spread across a variety of taxa and is not a unique behavior in brown recluses. These findings are discussed in relation to pest management practices.

  3. Reactive oxygen species and lipid peroxidation product-scavenging ability of yogurt organisms.

    Science.gov (United States)

    Lin, M Y; Yen, C L

    1999-08-01

    The antioxidative activity of the intracellular extracts of yogurt organisms was investigated. All 11 strains tested, including five strains of Streptococcus thermophilus and six strains of Lactobacillus delbrueckii ssp. bulgaricus, demonstrated an antioxidative effect on the inhibition of linoleic acid peroxidation. The antioxidative effect of intracellular extracts of 10(8) cells of yogurt organisms was equivalent to 25 to 96 ppm butylated hydroxytoluene, which indicated that all strains demonstrated excellent antioxidative activity. The scavenging of reactive oxygen species, hydroxyl radical, and hydrogen peroxide was studied for intracellular extracts of yogurt organisms. All strains showed reactive oxygen species-scavenging ability. Lactobacillus delbrueckii ssp. bulgaricus Lb demonstrated the highest hydroxyl radical-scavenging ability at 234 microM. Streptococcus thermophilus MC and 821 and L. delbrueckii ssp. bulgaricus 448 and 449 scavenged the most hydrogen peroxide at approximately 50 microM. The scavenging ability of lipid peroxidation products, t-butylhydroperoxide and malondialdehyde, was also evaluated. Results showed that the extracts were not able to scavenge the t-butylhydroperoxide. Nevertheless, malondialdehyde was scavenged well by most strains.

  4. Modelling the effect of boundary scavenging on Thorium and Protactinium profiles in the ocean

    International Nuclear Information System (INIS)

    Roy-Barman, M.

    2009-01-01

    The 'boundary scavenging' box model is a cornerstone of our understanding of the particle-reactive radionuclide fluxes between the open ocean and the ocean margins. However, it does not describe the radionuclide profiles in the water column. Here, I present the transport-reaction equations for radionuclides transported vertically by reversible scavenging on settling particles and laterally by horizontal currents between the margin and the open ocean. Analytical solutions of these equations are compared with existing data. In the Pacific Ocean, the model produces 'almost' linear 230 Th profiles (as observed in the data) despite lateral transport. However, omitting lateral transport biases the 230 Th based particle flux estimates by as much as 50%. 231 Pa profiles are well reproduced in the whole water column of the Pacific Margin and from the surface down to 3000 m in the Pacific subtropical gyre. Enhanced bottom scavenging or inflow of 231 Pa-poor equatorial water may account for the model-data discrepancy below 3000 m. The lithogenic 232 Th is modelled using the same transport parameters as 230 Th but a different source function. The main source of the 232 Th scavenged in the open Pacific is advection from the ocean margin, whereas a net flux of 230 Th produced in the open Pacific is advected and scavenged at the margin, illustrating boundary exchange. In the Arctic Ocean, the model reproduces 230 Th measured profiles that the uni-dimensional scavenging model or the scavenging-ventilation model failed to explain. Moreover, if lateral transport is ignored, the 230 Th based particle settling speed may by underestimated by a factor 4 at the Arctic Ocean margin. The very low scavenging rate in the open Arctic Ocean combined with the enhanced scavenging at the margin accounts for the lack of high 231 Pa/ 230 Th ratio in arctic sediments. (authors)

  5. The scavenger activities of tea polyphenol and quercetin against oxygen radicals

    International Nuclear Information System (INIS)

    Fang Ruoying; Cheng Jiwu; Hu Tianxi; Tu Tiecheng; Dong Jirong; Wang Wenfeng; Lin nianyun

    1992-01-01

    Studies of free radical biology and medicine have shown that carcinogenesis, vascular diseases of heart and brain, radiation injuries, ageing etc are strictly correlated with free radical injury of tissues. Thus, pharmacologists and biologists are focusing attention on searching for scavengers, especially naturally occurring antioxidant of oxidizing free radicals. Previous studies have indicated that phenolic antioxidants have efficient scavenger activities. Utilizing following methods including chemical luminescence, ESR spectroscopy and pulse radiolysis techniques the scavenger activities of tea polyphenols and quercetin against active species of oxygen have been studied

  6. Numerical Investigation of the Scavenging Process in Marine Two-Stroke Diesel Engines

    DEFF Research Database (Denmark)

    Andersen, Fredrik Herland; Hult, Johan; Nogenmyr, Karl-Johan

    2013-01-01

    The scavenging process is an integral part of any two-stroke internal combustion engine cycle whether it is spark ignited or compression ignited. The scavenging process is responsible for transporting the burned gases from the previous working stroke out of the combustion chamber to allow...... for the fresh charge or fresh air to enter for the next combustion/working stroke. This implies that the scavenging process is responsible for setting the initial condition for the combustion process, consequently affecting fuel economy, power output and emission of hazardous gases. Two-stroke diesel engines...

  7. Attendance of scavenging seabirds at trawler discards off Galicia, Spain

    Directory of Open Access Journals (Sweden)

    Julio Valeiras

    2003-07-01

    Full Text Available The occurrence of scavenger seabirds at fishing trawlers was studied off Galicia, Spain. A total of 9,368 seabirds of 23 species were recorded during 92 fishing operations in 1998 and 1999. The most common species were the yellow-legged and lesser black-backed gull (Larus cachinnans and L. fuscus, Sabine´s gull (L. sabini, the northern gannet (Morus bassanus, the great shearwater (Puffinus gravis, sooty shearwater (P. griseus, the Manx and Balearic shearwater (P. puffinus and P. mauretanicus, the great skua (Catharacta skua and terns (mainly Sterna hirundo and S. paradisaea. Other species occurred in small numbers: Leach´s petrel (Oceanodroma leucorhoa, the storm petrel (Hydrobates pelagicus, the little shearwater (Puffinus assimilis, Cory´s shearwater (Calonectris diomedea, the parasitic skua (Stercorarius parasiticus, the pomarine skua (S. pomarinus, the black-headed gull (Larus ridibundus, the glaucous gull (L. hyperboreus, the kittiwake (Rissa tridactyla, the sandwich tern (Sterna sandvicensis, the black tern (Chlidonias niger, the guillemot (Uria aalge and the little auk (Alle alle. The maximum number of seabirds recorded at a haul was 320. The maximum number of a particular species ranged from 120 great shearwaters to 250 yellow-legged/lesser black-backed gulls during a single haul. The differences in ship-follower species abundance are related to migratory movements but fisheries could also have a strong influence at a smaller scale on the distribution of seabirds off Galicia. The degree to which seabirds rely on fishery discards as food was not quantified, but may be important for several species.

  8. Effects of edaravone, a radical scavenger, on hepatocyte transplantation.

    Science.gov (United States)

    Hayashi, Chihiro; Ito, Masahiro; Ito, Ryoutaro; Murakumo, Akiko; Yamamoto, Naoki; Hiramatsu, Noriko; Fox, Ira J; Horiguchi, Akihiko

    2014-12-01

    Hepatocyte transplantation (HTx) has yielded significant improvements in liver function and survival in experimentally induced acute liver failure and liver-based metabolic disease. However, transplantation is inefficient, and it is thought that transplanted hepatocytes have a shortened lifespan because of inflammation involving excess nitric oxide (NO). The present study aimed to clarify whether edaravone, a free radical scavenger used to treat ischemic stroke, could reduce ischemic changes in hepatocyte-transplanted livers. Edaravone (3 mg/kg) was administered intravenously 24 h before HTx to Nagase analbuminemic rats (NARs). Hepatocytes were isolated, and 30 × 10(6) cells were injected in a 1.0-ml volume directly into the spleens of NARs. All experimental groups studied received FK506 to control rejection. Animals in Group A received medium-only; Group B received HTx only; and Group C received HTx and edaravone. Forty-eight hours after transplantation, the hepatocytes from animals were isolated and analyzed for staining with propidium iodide- and annexin-V using flow cytometry. Liver sections were also studied by immunostaining for albumin, and TUNEL. Peripheral blood serum albumin levels were measured on post-transplant days 0, 3, 5, 7, 10 and 14 using ELISA. The edaravone-treated animals demonstrated an increased number of engrafted donor hepatocytes in the liver. The edaravone-treated liver sections also contained fewer TUNEL-positive cells and animals that received edaravone had higher serum albumin levels post-transplantation. Hepatocytes were also found to have increased in numbers 2 weeks following treatment with edaravone. Edaravone administration during HTx can suppress apoptosis near the transplanted cells, increasing engraftment. These studies indicate its potential usefulness for future clinical application. © 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  9. Study of atmospheric pollution scavenging. Eighteenth progress report

    Energy Technology Data Exchange (ETDEWEB)

    Semonin, R.G.; Bartlett, J.D.; Bowersox, V.C.; Gatz, D.F.; Naiman, D.Q.; Peden, M.E.; Stahlhut, R.K.; Stensland, G.J.

    1980-07-01

    The analysis of aerosol samples obtained in rural east-central Illinois reveals a seasonal maximum in SO/sub 4/ during May to July and a similar pattern for NH/sub 4/. The annual median SO/sub 4/ is about 1 to 1.5 ..mu..g/m/sup 3/. In contrast to these ions, NO/sub 3/ displays highest values in the cold season. Soil-related species (Ca, K) seem to maximize in relation to farm tillage and harvesting practices. The NO/sub 3/ in recent precipitation samples over the northeast US increased between 1 and 2 times the values observed in the mid-1950's. A case study from SCORE-78 suggests that all ion concentrations analyzed from sequentially collected samples decreased from the onset of rain to a minimum corresponding to the heaviest rain rates. Four groups of elements in 10 event rain samples were identified using factor analysis. The groups include soluble and insoluble crustal elements, soluble pollutant metals and sulfate, and insoluble pollutant metals. Utilizing the factor analysis approach, the St. Louis METROMEX precipitation chemistry data showed that the SO/sub 4/ deposition patterns group consistently with those of other soluble pollutants. Additional factor analysis efforts on the St. Louis rainwater data set revealed that soluble and insoluble concentrations of a given element have different deposition patterns suggesting that scavenging and/or precipitation formation processes dictate the patterns. An approach to managing the vast data base of rain chemistry used in the above studies is described. The software also examines the data for certain aspects of quality assurance. The procedures used to analyze ambient air filter samples are discussed.

  10. Total iron binding capacity

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003489.htm Total iron binding capacity To use the sharing features on this page, please enable JavaScript. Total iron binding capacity (TIBC) is a blood test to ...

  11. Air capacity for Sydney

    OpenAIRE

    Forsyth, Peter

    2013-01-01

    Like most large cities, Sydney has an airport problem. Demand is increasing faster than supply, and additional capacity will be needed if costly rationing, and delays, are to be avoided. However, compared to many cities, the problems facing Sydney are modest. At the moment, demand is only just exceeding capacity. There is a good chance that the available capacity will be rationed efficiently. Options for expanding capacity are being evaluated well. There may be problems in the future- poor op...

  12. Responsibility and Capacities

    DEFF Research Database (Denmark)

    Ryberg, Jesper

    2014-01-01

    That responsible moral agency presupposes certain mental capacities, constitutes a widely accepted view among theorists. Moreover, it is often assumed that degrees in the development of the relevant capacities co-vary with degrees of responsibility. In this article it is argued that, the move from...... the view that responsibility requires certain mental capacities to the position that degrees of responsibility co-vary with degrees of the development of the mental capacities, is premature....

  13. Streptomyces sp. MUM212 as a Source of Antioxidants with Radical Scavenging and Metal Chelating Properties

    Directory of Open Access Journals (Sweden)

    Loh Teng-Hern Tan

    2017-05-01

    Full Text Available Reactive oxygen species and other radicals potentially cause oxidative damage to proteins, lipids, and DNA which may ultimately lead to various complications including mutations, carcinogenesis, neurodegeneration, cardiovascular disease, aging, and inflammatory disease. Recent reports demonstrate that Streptomyces bacteria produce metabolites with potent antioxidant activity that may be developed into therapeutic drugs to combat oxidative stress. This study shows that Streptomyces sp. MUM212 which was isolated from mangrove soil in Kuala Selangor, Malaysia, could be a potential source of antioxidants. Strain MUM212 was characterized and determined as belonging to the genus Streptomyces using 16S rRNA gene phylogenetic analysis. The MUM212 extract demonstrated significant antioxidant activity through DPPH, ABTS and superoxide radical scavenging assays and also metal-chelating activity of 22.03 ± 3.01%, 61.52 ± 3.13%, 37.47 ± 1.79%, and 41.98 ± 0.73% at 4 mg/mL, respectively. Moreover, MUM212 extract was demonstrated to inhibit lipid peroxidation up to 16.72 ± 2.64% at 4 mg/mL and restore survival of Vero cells from H2O2-induced oxidative damages. The antioxidant activities from the MUM212 extract correlated well with its total phenolic contents; and this in turn was in keeping with the gas chromatography–mass spectrometry analysis which revealed the presence of phenolic compounds that could be responsible for the antioxidant properties of the extract. Other chemical constituents detected included hydrocarbons, alcohols and cyclic dipeptides which may have contributed to the overall antioxidant capacity of MUM212 extract. As a whole, strain MUM212 seems to have potential as a promising source of novel molecules for future development of antioxidative therapeutic agents against oxidative stress-related diseases.

  14. Scoparone attenuates RANKL-induced osteoclastic differentiation through controlling reactive oxygen species production and scavenging

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang-Hyun; Jang, Hae-Dong, E-mail: haedong@hnu.kr

    2015-02-15

    Scoparone, one of the bioactive components of Artemisia capillaris Thunb, has various biological properties including immunosuppressive, hepatoprotective, anti-allergic, anti-inflammatory, and antioxidant effects. This study aims at evaluating the anti-osteoporotic effect of scoparone and its underlying mechanism in vitro. Scoparone demonstrated potent cellular antioxidant capacity. It was also found that scoparone inhibited the receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation and suppressed cathepsin K and tartrate-resistant acid phosphatase (TRAP) expression via c-jun N-terminal kinase (JNK)/extracellular signal-regulated kinase (ERK)/p38-mediated c-Fos–nuclear factor of activated T cells, cytoplasmic 1 (NFATc1) signaling pathway. During osteoclast differentiation, the production of general reactive oxygen species (ROS) and superoxide anions was dose-dependently attenuated by scoparone. In addition, scoparone diminished NADPH (nicotinamide adenine dinucleotide phosphate) oxidase 1 (Nox1) expression and activation via the tumor necrosis factor receptor-associated factor 6 (TRAF6)–cSrc–phosphatidylinositol 3-kinase (PI3k) signaling pathway and prevented the disruption of mitochondrial electron transport chain system. Furthermore, scoparone augmented the expression of superoxide dismutase 1 (SOD1) and catalase (CAT). The overall results indicate that the inhibitory effect of scoparone on RANKL-induced osteoclast differentiation is attributed to the suppressive effect on ROS and superoxide anion production by inhibiting Nox1 expression and activation and protecting the mitochondrial electron transport chain system and the scavenging effect of ROS resulting from elevated SOD1 and CAT expression. - Highlights: • Scoparone dose-dependently inhibited RANKL-induced osteoclast differentiation. • Scoparone diminished general ROS and superoxide anions in a dose-dependent manner. • Scoparone inhibited Nox1 expression and

  15. CDMA systems capacity engineering

    CERN Document Server

    Kim, Kiseon

    2004-01-01

    This new hands-on resource tackles capacity planning and engineering issues that are crucial to optimizing wireless communication systems performance. Going beyond the system physical level and investigating CDMA system capacity at the service level, this volume is the single-source for engineering and analyzing systems capacity and resources.

  16. PAYMENT CAPACITY SENSITIVITY FACTORS

    Directory of Open Access Journals (Sweden)

    Daniel BRÎNDESCU – OLARIU

    2014-11-01

    The results of the study facilitate the determination and classification of the main sensitivity factors for the payment capacity at sample level, the establishment of general benchmarks for the payment capacity (as no such benchmarks currently exist in the Romanian literature and the identification of the mechanisms through which the variation of different factors impacts the payment capacity.

  17. Computational study of the structure-free radical scavenging relationship of procyanidins.

    Science.gov (United States)

    Mendoza-Wilson, Ana María; Castro-Arredondo, Sergio Ivan; Balandrán-Quintana, René Renato

    2014-10-15

    Procyanidins (PCs) are effective free radical scavengers, however, their antioxidant ability is variable because they have different degrees of polymerisation, are composed by distinct types of subunits and are very susceptible to changes in conformation. In this work the structure-free radical scavenging relationship of monomers, dimers and trimers of PCs was studied through the hydrogen atom transfer (HAT), sequential proton-loss electron-transfer (SPLET) and single electron transfer followed by proton transfer (SET-PT) mechanisms in aqueous phase, employing the Density Functional Theory (DFT) computational method. The structure-free radical scavenging relationship of PCs showed a very similar behaviour in HAT and SET-PT mechanisms, but very different in the SPLET mechanism. The structural factor that showed more effects on the ability of PCs to scavenge free radicals in aqueous phase was the conformation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Comparative in vitro study on free radical scavenging potential of selected bivalve species

    Digital Repository Service at National Institute of Oceanography (India)

    Shenai-Tirodkar, P.S.; Pawar, R.T.; Jagtap, T.G.

    Bivalves such as, Crassostrea spp., Meretrix casta, Placuna placenta and Polymesoda erosa are largely consumed as edible seafood. It forms natural source of nutrition in coastal and worldwide population. Free radical scavenging activities...

  19. Pigment and amylase production in Penicillium sp NIOM-02 and its radical scavenging activity

    Digital Repository Service at National Institute of Oceanography (India)

    Dhale, M.A.; VijayRaj, A.S.

    Penicillium sp NIOM-02 was isolated from the marine sediment, produced red pigment. The pigment extracted from this fungus scavenged 2, 2-diphenyl-1-pycrylhydrazyl (DPPH) radical. Penicillium sp NIOM-02 grown in media containing corn steep liquor...

  20. Antioxidant properties of a radical-scavenging peptide purified from enzymatically prepared fish skin gelatin hydrolysate.

    Science.gov (United States)

    Mendis, Eresha; Rajapakse, Niranjan; Kim, Se-Kwon

    2005-02-09

    Hoki (Johnius belengerii) skin gelatin was hydrolyzed with three commercial enzymes to identify radical-scavenging potencies of derived peptides. Peptides derived from tryptic hydrolysate exhibited the highest scavenging activities on superoxide, carbon-centered 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals assessed by ESR spectroscopy. Following consecutive chromatographic separations of tryptic hydroolysate, the peptide sequence His-Gly-Pro-Leu-Gly-Pro-Leu (797 Da) acted as a strong radical scavenger under studied conditions. Further, this peptide could act as an antioxidant against linoleic acid peroxidation and the activity was closer to the highly active synthetic antioxidant butylated hydroxytoluene (BHT). In addition, antioxidative enzyme levels in cultured human hepatoma cells were increased in the presence of this peptide and it was presumed to be the peptide involved in maintaining the redox balance in the cell environment. Present data indicate that free-radical-scavenging activities of hoki skin gelatin peptides substantially contribute to their antioxidant properties measured in different oxidative systems.

  1. Screening of radical scavenging activity of some medicinal and aromatic plant extracts

    NARCIS (Netherlands)

    Miliauskas, G.; Venskutonis, R.P.; Beek, van T.A.

    2004-01-01

    Extracts of 12 medicinal and aromatic plants were investigated for their radical scavenging activity using DPPH and ABTS assays: Salvia sclarea, Salvia glutinosa, Salvia pratensis, Lavandula angustifolia, Calendula officinalis, Matricaria recutita, Echinacea purpurea, Rhaponticum carthamoides,

  2. In vivo heme scavenging by Staphylococcus aureus IsdC and IsdE proteins

    International Nuclear Information System (INIS)

    Mack, John; Vermeiren, Christie; Heinrichs, David E.; Stillman, Martin J.

    2004-01-01

    We report the first characterization of the in vivo porphyrin scavenging abilities of two components of a newly discovered heme scavenging system involving iron-regulated surface determinant (Isd) proteins. These proteins are present within the cell envelope of the Gram-positive human pathogen Staphylococcus aureus. IsdC and IsdE, when expressed heterologously in Escherichia coli, efficiently scavenged intracellular heme and resulted in de novo heme synthesis in excess of 100-fold above background. Magnetic circular dichroism analyses showed that the heme-binding properties of the two proteins differ significantly from one another. IsdC bound almost exclusively free-base protoporphyrin IX, whereas the IsdE protein was associated with low spin Fe(III) and Fe(II) heme. These properties provide important insight into the possible mechanisms of iron scavenging from bound heme by Isd proteins

  3. Deer carcass decomposition and potential scavenger exposure to chronic wasting disease

    Science.gov (United States)

    Jennelle, C.S.; Samuel, M.D.; Nolden, C.A.; Berkley, E.A.

    2009-01-01

    Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy afflicting the Cervidae family in North America, causing neurodegeneration and ultimately death. Although there are no reports of natural cross-species transmission of CWD to noncervids, infected deer carcasses pose a potential risk of CWD exposure for other animals. We placed 40 disease-free white-tailed deer (Odocoileus virginianus) carcasses and 10 gut piles in the CWD-affected area of Wisconsin (USA) from September to April in 2003 through 2005. We used photos from remotely operated cameras to characterize scavenger visitation and relative activity. To evaluate factors driving the rate of carcass removal (decomposition), we used KaplanMeier survival analysis and a generalized linear mixed model. We recorded 14 species of scavenging mammals (6 visiting species) and 14 species of scavenging birds (8 visiting species). Prominent scavengers included American crows (Corvus brachyrhynchos), raccoons (Procyon lotor), and Virginia opossums (Didelphis virginiana). We found no evidence that deer consumed conspecific remains, although they visited gut piles more often than carcasses relative to temporal availability in the environment. Domestic dogs, cats, and cows either scavenged or visited carcass sites, which could lead to human exposure to CWD. Deer carcasses persisted for 18 days to 101 days depending on the season and year, whereas gut piles lasted for 3 days. Habitat did not influence carcass decomposition, but mammalian and avian scavenger activity and higher temperatures were positively associated with faster removal. Infected deer carcasses or gut piles can serve as potential sources of CWD prions to a variety of scavengers. In areas where surveillance for CWD exposure is practical, management agencies should consider strategies for testing primary scavengers of deer carcass material.

  4. Uses and flock management practices of scavenging chickens in Wolaita Zone of southern Ethiopia.

    Science.gov (United States)

    Desta, Takele Taye; Wakeyo, Oli

    2012-03-01

    Rearing of scavenging chickens is among the most commonly practiced farm activities in Ethiopia. This system is dominated by indigenous chickens. Output from indigenous chickens is low due to poor management and absence of intense selection that is intended to improve economically important traits. This showed that village chickens are rather evolved for adaptation traits. However, the level of risk is low, and this has made rearing of scavenging chickens a choice of farm activity for smallholder farmers. The objective of this study was to characterize the scavenging chickens' production system in Wolaita Zone. Single-visit survey involving individual interview of 119 farmers and 6 focus group discussions was used to collect the data. Our results showed that rearing of scavenging chickens was constrained especially by disease and predation problems. However, farmers proposed a set of solutions to minimize the effect of these problems. Rearing of scavenging chickens fulfils the multi-functional need of the society. This system has special features because it can sustain in its own without the need for modern commercial chicken farming facilities. However, farmers also reported the drawbacks of rearing of scavenging chickens and these mainly include uproot of garden crops and tiresomeness of the night watching. Selection of chickens was mainly depending on physically observed traits like body size and plumage colour. The initial foundation flock was mainly obtained from the local market. The ideal place for scavenging chickens production is the one that has intermediate weather condition and has some trees that can be used as shade; however, it was substantiated that it has to be free from bush and shrubs, weeds and wet lands. Therefore, these pieces of knowledge embedded among smallholder farmers need to be well documented and synthesized to design an appropriate type of technology packages that can be communicated back to farmers to improve productivity of the

  5. Study of anti-oxidation and scavenging effects on free radicals of quercetin

    International Nuclear Information System (INIS)

    Wang Chongdao; Qiang Yizhong; Lao Qinhua; Shao Yuan

    1999-01-01

    The effects of Quercetin on the contents of lipid peroxides (LPO) in the mice caused by γ-whole-body irradiation by method of the modified spectrophotometry of TBA, and the scavenging effects of Quercetin on the free radicals of DNA induced by radiation exposure by means of ESR technique were investigated. The results demonstrates that Quercetin has a good anti-oxidation effect and is very effective in scavenging of free radicals

  6. Studies on free radical scavenging activity in Chinese seaweeds part I. Screening results

    Science.gov (United States)

    Yan, Xiao-Jun; Fang, Guo-Ming; Lou, Qing-Xiang

    1999-09-01

    Antioxidants have attracted the attention of researchers due to their beneficial effects as free radical scavengers. Application of a stable free radical named 1, 1-diphenyl-2-picrylhydrazyl(DPPH) to screen the free radical scavenging activity in 27 species of Chinese seaweed showed that 15 of them had significant activity in at least one of the organic solvent extracts. The most interesting seaweed species were Gelidium amansii, Gloiosiphonia capillaris, Polysiphonia urceolata, Sargassum kjellmanianum, Desmarestia viridis, and Rhodomela teres.

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

    International Nuclear Information System (INIS)

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

    1999-11-01

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

  8. Numerical modeling of aerosol particles scavenging by drops as a process of air depollution

    OpenAIRE

    Cherrier , Gaël

    2017-01-01

    This PhD-Thesis is dedicated to the numerical modeling of aerosol particles scavenging by drops. Investigated situations are about aerosol particles of aerodynamic diameter ranging from 1 nm to 100 µm captured in the air by water drops of diameter varying between 80 µm and 600 µm, with corresponding droplet Reynolds number ranging between 1 and 100. This air depollution modeling is achieved in two steps. The first step consists in obtaining a scavenging kernel predicting the flow rate of aero...

  9. Precipitation Scavenging of Aerosol Particles at a Rural Site in the Czech Republic.

    Czech Academy of Sciences Publication Activity Database

    Zíková, Naděžda; Ždímal, Vladimír

    2016-01-01

    Roč. 67, č. 2016 (2016), s. 27343 ISSN 0280-6509 R&D Projects: GA ČR GAP209/11/1342 EU Projects: European Commission(XE) 654109 - ACTRIS-2; European Commission(XE) 262254 - ACTRIS Institutional support: RVO:67985858 Keywords : below- cloud scavenging * in- cloud scavenging * hydrometeors Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.402, year: 2015

  10. Gallic acid as an oxygen scavenger in bio-based multilayer packaging films

    OpenAIRE

    Pant, Astrid; Sängerlaub, Sven; Müller, Kajetan

    2017-01-01

    Oxygen scavengers are used in food packaging to protect oxygen-sensitive food products. A mixture of gallic acid (GA) and sodium carbonate was used as an oxygen scavenger (OSc) in bio-based multilayer packaging films produced in a three-step process: compounding, flat film extrusion, and lamination. We investigated the film surface color as well as oxygen absorption at different relative humidities (RHs) and temperatures, and compared the oxygen absorption of OSc powder, monolayer films, and ...

  11. Increasing land-use intensity reverses the relative occupancy of two quadrupedal scavengers

    OpenAIRE

    Twining, Joshua P.; Bernard, Henry; Ewers, Robert M.

    2017-01-01

    Human land use is continuously altering the natural environment, yet the greater ecological implications of this change for many groups that are key to healthy ecosystem functioning remains uncharacterised in the tropics. Terrestrial scavenging vertebrates are one such group, providing integral ecosystem services through the removal of carrion which is a crucial component of both nutrient cycling and disease dynamics. To explore how anthropogenic processes may affect forest scavengers, we inv...

  12. The scavenging effects of tea polyphenol and quercetin on active oxygen species

    International Nuclear Information System (INIS)

    Fang Ruoying; Cheng Jiwu; Hu Tianxi; Tu Tiechen; Dong Jirong; Wang Wenfeng; Lin Nianyun

    1993-01-01

    The abilities of scavenging active oxygen species, O 2 free radical and OH., by tea polyphenols and quercetin have been studied by chemiluminescence, ESR and pulse radiolysis. Tea polyphenols and quercetin are all phenolic antioxidants. The synergetic studies show that both tea polyphenols and quercetin are strong free radical scavengers. Tea polyphenols are better than quercetin. the results from CL studies are in good accord with those from ESR and PR studies

  13. Postmortem scavenging by the Virginia opossum (Didelphis virginiana): Impact on taphonomic assemblages and progression.

    Science.gov (United States)

    King, Kama A; Lord, Wayne D; Ketchum, Heather R; O'Brien, R Christopher

    2016-09-01

    The Virginia opossum (Didelphis virginiana) is a highly active scavenger whose behavior has significant impacts on rates of decomposition and skeletonization, which have previously not been addressed. In this study, scavenging by the opossum led to the skeletonization of carcasses in half of the accumulated degree days (ADD) of a comparable non-scavenged control carcass. Opossums used body orifices, as well as natural tears caused by the decomposition process, to access internal tissues and consume them. This activity resulted in little movement of the carcass and the retained appearance of natural undisturbed decomposition. This concealed activity has the potential to cause drastically incorrect estimates of time since deposition and post-mortem interval. Scavenging by opossums was also found to leave distinct tooth mark and other defects on bone, which have not been previously distinguished in the literature. This research suggests, beyond effects on PMI, that scavenging by opossums has been historically overlooked and misattributed to canid scavengers. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. Radical Scavenging and Anti-Inflammatory Activities of Representative Anthocyanin Groupings from Pigment-Rich Fruits and Vegetables

    Directory of Open Access Journals (Sweden)

    Federica Blando

    2018-01-01

    Full Text Available Anthocyanins, the naturally occurring pigments responsible for most red to blue colours of flowers, fruits and vegetables, have also attracted interest because of their potential health effects. With the aim of contributing to major insights into their structure–activity relationship (SAR, we have evaluated the radical scavenging and biological activities of selected purified anthocyanin samples (PASs from various anthocyanin-rich plant materials: two fruits (mahaleb cherry and blackcurrant and two vegetables (black carrot and “Sun Black” tomato, differing in anthocyanin content (ranging from 4.9 to 38.5 mg/g DW and molecular structure of the predominant anthocyanins. PASs from the abovementioned plant materials have been evaluated for their antioxidant capacity using Trolox Equivalent Antioxidant Capacity (TEAC and Oxygen Radical Absorbance Capacity (ORAC assays. In human endothelial cells, we analysed the anti-inflammatory activity of different PASs by measuring their effects on the expression of endothelial adhesion molecules VCAM-1 and ICAM-1. We demonstrated that all the different PASs showed biological activity. They exhibited antioxidant capacity of different magnitude, higher for samples containing non-acylated anthocyanins (typical for fruits compared to samples containing more complex anthocyanins acylated with cinnamic acid derivatives (typical for vegetables, even though this order was slightly reversed when ORAC assay values were expressed on a molar basis. Concordantly, PASs containing non-acylated anthocyanins reduced the expression of endothelial inflammatory antigens more than samples with aromatic acylated anthocyanins, suggesting the potential beneficial effect of structurally diverse anthocyanins in cardiovascular protection.

  15. Silica-scavenging effects in ceria-based solid electrolytes

    Directory of Open Access Journals (Sweden)

    Ivanova, D.

    2008-08-01

    Full Text Available Composite materials based on gadolinium doped ceria (CGO with additions of silica, with both silica and lanthanum oxide, and with lanthanum silicate, were prepared by the conventional ceramic route, to assess the silica scavenging role of lanthanum oxide additions. Structural, microstructural and electrical characterization of these samples confirmed the formation of one apatite type lanthanum silicate-based phase from reaction of silica with lanthanum oxide. The formation of this phase occurred in parallel with a significant enhancement of the grain boundary conductivity of these composite materials. Further interaction between constituents, involving diffusion of La to CGO, and Ce and Gd to the apatite phase, had no significant consequences on the electrical performance of these materials. Overall, lanthanum oxide was shown to remove the siliceous phases from the grain boundaries of CGO.

    Se prepararon materiales compuestos basados en óxido de cerio dopado con gadolinio (TGO con adicciones de sílice, con sílice y óxido de lantano y silicato del lantano, mediante procesamiento cerámico convencional con objeto de confirmar el papel secuestrante de sílice de las adicciones. La caracterización estructural, microestructural y eléctrica de las muestras confirmó la formación de una fase tipo apatito basada en silicato de lantano a partir de la reacción de la sílice con el óxido de lantano. La formación de esta fase ocurre en paralelo con un incremento significativo de la conductividad a través del borde de grano de estos materiales. La interacción entre los constituyentes, incluyendo la difusión del La al CGO, y el Ce y el Gd a la fase apatito, no tiene consecuencias significativas sobre el comportamiento eléctrico de estos materiales. Resumiendo, el óxido de lantano es capaz de eliminar las fases silicias del borde de grano del CGO.

  16. Antioxidant Capacity of Selected Plant Extracts and Their Essential Oils

    Directory of Open Access Journals (Sweden)

    Charalampos Proestos

    2013-01-01

    Full Text Available The main objective of this study was the screening of some selected aromatic plants very popular in Greece, with respect to their total phenolic content, antioxidant capacity, reducing activity, and oxidative stability. All plants were extracted with the conventional method, reflux with methanol. The essential oils of the plants were also analyzed for their antioxidant properties. The total phenolic content was determined by the Folin-Ciocalteu method using gallic acid as the standard, while the phenolic substances were identified and quantified by High Performance Liquid Chromatography (HPLC coupled with a multi-wavelength ultraviolet-visible (UV-vis detector. The antioxidant capacity of the plant extracts was measured by their ability to scavenge free radicals such as (a DPPH (2,2-diphenyl-1-picrylhydrazyl and, (b ABTS (2,2′-azinobis-(3-ethylbenzothiaziline-6- sulfonate. The Folin-Ciocalteu method proved the existence of antioxidants in the aromatic plant extracts. Taking into account the results of the DPPH and ABTS methods, the free radical scavenging capacity was confirmed. Eventually, all plants exhibited low but noticeable protection levels against lipid oxidation, as determined by the Rancimat test.

  17. Quantification of Phenolic Compounds and In Vitro Radical Scavenging Abilities with Leaf Extracts from Two Varieties of Psidium guajava L.

    Directory of Open Access Journals (Sweden)

    Julio César Camarena-Tello

    2018-02-01

    Full Text Available Guava leaf (Psidium guajava L. extracts are used in both traditional medicine and the pharmaceutical industry. The antioxidant compounds in P. guajava leaves can have positive effects including anti-inflammatory, anti-hyperglycemic, hepatoprotective, analgesic, anti-cancer effects, as well as protecting against cardiovascular diseases. In the present study, phenolic compounds and in vitro antioxidant capacity were measured in extracts obtained with polar and non-polar solvents from leaves of two varieties of guava, Calvillo Siglo XXI and Hidrozac. The quantity of total phenolics and total flavonoids were expressed as equivalents of gallic acid and quercetin, respectively. Hydroxyl radical, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS, 2,2-diphenyl-1-picrylhydrazyl (DPPH, and Oxygen Radical Absorbance Capacity using fluorescein (ORAC-FL in vitro tests were used to assess the radical scavenging abilities of the extracts. The total phenolics were higher in the aqueous fraction of the variety Calvillo Siglo XXI, while in the Hidrozac variety total phenolics were higher in the acetone and chloroform fractions. Total flavonoids were higher in all fractions in the variety Calvillo Siglo XXI. Total phenolics showed a highly positive correlation for ORAC-FL, and a moderately positive correlation with hydroxyl radicals. Finally, total flavonoids showed a slightly positive correlation for ORAC-FL and hydroxyl radicals. Both varieties of guava leaf extract showed excellent antioxidant properties.

  18. Quantification of Phenolic Compounds and In Vitro Radical Scavenging Abilities with Leaf Extracts from Two Varieties of Psidium guajava L.

    Science.gov (United States)

    Martínez-Flores, Héctor Eduardo; Garnica-Romo, Ma. Guadalupe; Padilla-Ramírez, José Saúl; Saavedra-Molina, Alfredo; Alvarez-Cortes, Osvaldo; Bartolomé-Camacho, María Carmen; Rodiles-López, José Octavio

    2018-01-01

    Guava leaf (Psidium guajava L.) extracts are used in both traditional medicine and the pharmaceutical industry. The antioxidant compounds in P. guajava leaves can have positive effects including anti-inflammatory, anti-hyperglycemic, hepatoprotective, analgesic, anti-cancer effects, as well as protecting against cardiovascular diseases. In the present study, phenolic compounds and in vitro antioxidant capacity were measured in extracts obtained with polar and non-polar solvents from leaves of two varieties of guava, Calvillo Siglo XXI and Hidrozac. The quantity of total phenolics and total flavonoids were expressed as equivalents of gallic acid and quercetin, respectively. Hydroxyl radical, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and Oxygen Radical Absorbance Capacity using fluorescein (ORAC-FL) in vitro tests were used to assess the radical scavenging abilities of the extracts. The total phenolics were higher in the aqueous fraction of the variety Calvillo Siglo XXI, while in the Hidrozac variety total phenolics were higher in the acetone and chloroform fractions. Total flavonoids were higher in all fractions in the variety Calvillo Siglo XXI. Total phenolics showed a highly positive correlation for ORAC-FL, and a moderately positive correlation with hydroxyl radicals. Finally, total flavonoids showed a slightly positive correlation for ORAC-FL and hydroxyl radicals. Both varieties of guava leaf extract showed excellent antioxidant properties. PMID:29495514

  19. Quantification of Phenolic Compounds and In Vitro Radical Scavenging Abilities with Leaf Extracts from Two Varieties of Psidium guajava L.

    Science.gov (United States)

    Camarena-Tello, Julio César; Martínez-Flores, Héctor Eduardo; Garnica-Romo, Ma Guadalupe; Padilla-Ramírez, José Saúl; Saavedra-Molina, Alfredo; Alvarez-Cortes, Osvaldo; Bartolomé-Camacho, María Carmen; Rodiles-López, José Octavio

    2018-02-27

    Guava leaf ( Psidium guajava L.) extracts are used in both traditional medicine and the pharmaceutical industry. The antioxidant compounds in P. guajava leaves can have positive effects including anti-inflammatory, anti-hyperglycemic, hepatoprotective, analgesic, anti-cancer effects, as well as protecting against cardiovascular diseases. In the present study, phenolic compounds and in vitro antioxidant capacity were measured in extracts obtained with polar and non-polar solvents from leaves of two varieties of guava, Calvillo Siglo XXI and Hidrozac. The quantity of total phenolics and total flavonoids were expressed as equivalents of gallic acid and quercetin, respectively. Hydroxyl radical, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and Oxygen Radical Absorbance Capacity using fluorescein (ORAC-FL) in vitro tests were used to assess the radical scavenging abilities of the extracts. The total phenolics were higher in the aqueous fraction of the variety Calvillo Siglo XXI, while in the Hidrozac variety total phenolics were higher in the acetone and chloroform fractions. Total flavonoids were higher in all fractions in the variety Calvillo Siglo XXI. Total phenolics showed a highly positive correlation for ORAC-FL, and a moderately positive correlation with hydroxyl radicals. Finally, total flavonoids showed a slightly positive correlation for ORAC-FL and hydroxyl radicals. Both varieties of guava leaf extract showed excellent antioxidant properties.

  20. Catalytic soman scavenging by Y337A/F338A acetylcholinesterase mutant assisted with novel site-directed aldoximes

    Science.gov (United States)

    Kovarik, Zrinka; Hrvat, Nikolina Maček; Katalinić, Maja; Sit, Rakesh K.; Paradyse, Alexander; Žunec, Suzana; Musilek, Kamil; Fokin, Valery V.; Taylor, Palmer; Radić, Zoran

    2016-01-01

    Exposure to the nerve agent soman is difficult to treat due to the rapid dealkylation of soman-acetylcholinesterase (AChE) conjugate known as aging. Oxime antidotes commonly used to reactivate organophosphate inhibited AChE are ineffective against soman, while the efficacy of the recommended nerve agent bioscavenger butyrylcholinesterase is limited by strictly stoichiometric scavenging. To overcome this limitation, we tested ex vivo, in human blood, and in vivo, in soman exposed mice, the capacity of aging-resistant human AChE mutant Y337A/F338A in combination with oxime HI-6 to act as a catalytic bioscavenger of soman. HI-6 was previously shown in vitro to efficiently reactivate this mutant upon soman, as well as VX, cyclosarin, sarin and paraoxon inhibition. We here demonstrate that ex vivo, in whole human blood, 1 μM soman was detoxified within 30 minutes when supplemented with 0.5 μM Y337A/F338A AChE and 100 μM HI-6. This combination was further tested in vivo. Catalytic scavenging of soman in mice improved the therapeutic outcome and resulted in the delayed onset of toxicity symptoms. Furthermore, in a preliminary in vitro screen we identified an even more efficacious oxime than HI-6, in a series of forty-two pyridinium aldoximes, and five imidazole 2-aldoxime N-propyl pyridinium derivatives. One of the later imidazole aldoximes, RS-170B, was a 2–3 –fold more effective reactivator of Y337A/F338A AChE than HI-6 due to the smaller imidazole ring, as indicated by computational molecular models, that affords a more productive angle of nucleophilic attack. PMID:25835984

  1. Enhanced protection of PDMS-embedded palladium catalysts by co-embedding of sulphide-scavengers.

    Science.gov (United States)

    Comandella, Daniele; Ahn, Min Hyung; Kim, Hojeong; Mackenzie, Katrin

    2017-12-01

    For Pd-containing hydrodechlorination catalysts, coating with poly(dimethyl siloxane) (PDMS) was proposed earlier as promising protection scheme against poisoning. The PDMS coating can effectively repel non-permeating poisons (such as SO 3 2- ) retaining the hydrodechlorination Pd activity. In the present study, the previously achieved protection efficiency was enhanced by incorporation of sulphide scavengers into the polymer. The embedded scavengers were able to bind permeating non-ionic poisons (such as H 2 S) during their passage through PDMS prior to Pd contact which ensured an extended catalyst lifetime. Three scavenger types forming non-permeable sulphur species from H 2 S - alkaline, oxidative or iron-based compounds - were either incorporated into single-layer coats around individual Pd/Al 2 O 3 particles or into a second layer above Pd-containing PDMS films (Pd-PDMS). Hydrodechlorination and hydrogenation were chosen as model reactions, carried out in batch and continuous-flow reactors. Batch tests with all scavenger-containing catalysts showed extended Pd protection compared to scavenger-free catalysts. Solid alkaline compounds (Ca(OH) 2 , NaOH, CaO) and MnO 2 showed the highest instantaneous scavenger efficiencies (retained Pd activity=30-60%), while iron-based catalysts, such as nano zero-valent iron (nZVI) or ferrocene (FeCp 2 ), proved less efficient (1-10%). When stepwise poisoning was applied, the protection efficiency of iron-based and oxidizing compounds was higher in the long term than that of alkaline solids. Long-term experiments in mixed-flow reactors were performed with selected scavengers, revealing the following trend of protection efficiency: CaO 2 >Ca(OH) 2 >FeCp 2 . Under field-simulating conditions using a fixed-bed reactor, the combination of sulphide pre-oxidation in the water phase by H 2 O 2 and local scavenger-enhanced Pd protection was successful. The oxidizing agent H 2 O 2 does not disturb the Pd-catalysed reduction, while the

  2. Experimental Assessment of Moringa oleifera Leaf and Fruit for Its Antistress, Antioxidant, and Scavenging Potential Using In Vitro and In Vivo Assays

    Science.gov (United States)

    Luqman, Suaib; Srivastava, Suchita; Kumar, Ritesh; Maurya, Anil Kumar; Chanda, Debabrata

    2012-01-01

    We have investigated effect of Moringa oleifera leaf and fruit extracts on markers of oxidative stress, its toxicity evaluation, and correlation with antioxidant properties using in vitro and in vitro assays. The aqueous extract of leaf was able to increase the GSH and reduce MDA level in a concentration-dependent manner. The ethanolic extract of fruit showed highest phenolic content, strong reducing power and free radical scavenging capacity. The antioxidant capacity of ethanolic extract of both fruit and leaf was higher in the in vitro assay compared to aqueous extract which showed higher potential in vivo. Safety evaluation studies showed no toxicity of the extracts up to a dose of 100 mg/kg body weight. Our results support the potent antioxidant activity of aqueous and ethanolic extract of Moringa oleifera which adds one more positive attribute to its known pharmacological importance. PMID:22216055

  3. Experimental Assessment of Moringa oleifera Leaf and Fruit for Its Antistress, Antioxidant, and Scavenging Potential Using In Vitro and In Vivo Assays

    Directory of Open Access Journals (Sweden)

    Suaib Luqman

    2012-01-01

    Full Text Available We have investigated effect of Moringa oleifera leaf and fruit extracts on markers of oxidative stress, its toxicity evaluation, and correlation with antioxidant properties using in vitro and in vitro assays. The aqueous extract of leaf was able to increase the GSH and reduce MDA level in a concentration-dependent manner. The ethanolic extract of fruit showed highest phenolic content, strong reducing power and free radical scavenging capacity. The antioxidant capacity of ethanolic extract of both fruit and leaf was higher in the in vitro assay compared to aqueous extract which showed higher potential in vivo. Safety evaluation studies showed no toxicity of the extracts up to a dose of 100 mg/kg body weight. Our results support the potent antioxidant activity of aqueous and ethanolic extract of Moringa oleifera which adds one more positive attribute to its known pharmacological importance.

  4. Seasonal Difference in Antioxidant Capacity and Active Compounds Contents of Eucommia ulmoides Oliver Leaf

    Directory of Open Access Journals (Sweden)

    Jingfang Zhang

    2013-02-01

    Full Text Available Leaf of Eucommia ulmoides Oliver (EU is a Traditional Chinese Medicine and a functional food in China. Antioxidant contents of EU leaves, which were collected monthly during the period of May–October in three years, were determined. Samples’ antioxidant capacity was characterized by DPPH radical scavenging activity, hydroxyl radical scavenging activity, ferrous chelating ability, and antioxidant capacity in linoleic acid emulsion and in rapeseed oil assays. The results showed that contents of some active compounds and antioxidant activity were related to a certain time of the year. Samples collected in August showed high content of phenolics, and the samples collected in May contained higher amount of flavonoids than other samples. Leaves collected in May or June exhibited high contents of rutin, quercetin, geniposidic acid and aucubin. The August leaves showed stable and high DPPH radical scavenging activity, and ferrous chelating ability. May samples showed strong inhibitory effects on oxidation of rapeseed oil and linoleic acid. The DPPH radical scavenging activity was related to the total phenolics content. Flavonoids played an important role in the inhibitory effects on rapeseed oil and linoleic acid oxidation. Therefore, August and May were indicated as the best months to harvest EU leaves for industry.

  5. Antioxidant Capacity and Proanthocyanidin Composition of the Bark of Metasequoia glyptostroboides.

    Science.gov (United States)

    Chen, Fengyang; Zhang, Lin; Zong, Shuling; Xu, Shifang; Li, Xiaoyu; Ye, Yiping

    2014-01-01

    Metasequoia glyptostroboides Hu et Cheng is the only living species in the genus Metasequoia Miki ex Hu et Cheng (Taxodiaceae), which is well known as a "living fossil" species. In the Chinese folk medicine, the leaves and bark of M. glyptostroboides are used as antimicrobic, analgesic, and anti-inflammatory drug for dermatic diseases. This study is the first to report the free radical scavenging capacity, antioxidant activity, and proanthocyanidin composition of the bark of M. glyptostroboides. We observed total of six extracts and fractions, which were easily obtained by water-ethanol extraction and followed by a further separation with D101 resin column chromatography, had significant DPPH radical, superoxide anion radical, and hydroxyl radical scavenging capacity, total antioxidative capacity (T-AOC), lipid peroxidation inhibitory activity, and metal ions chelating capacity. The fraction MGEB, which was obtained by 60% ethanol extraction and followed by a further separation with D101 resin column chromatograph, possessed the highest proanthocyanidin content and the highest free radical scavenging and antioxidant activities. Furthermore, MGEB could significantly protect against CCl4 induced acute liver injury through inhibition of oxidative stress in mice. In addition, ten proanthocyanidins were isolated from MGEB, and six of them were firstly reported from this plant.

  6. Antioxidant Capacity and Proanthocyanidin Composition of the Bark of Metasequoia glyptostroboides

    Directory of Open Access Journals (Sweden)

    Fengyang Chen

    2014-01-01

    Full Text Available Metasequoia glyptostroboides Hu et Cheng is the only living species in the genus Metasequoia Miki ex Hu et Cheng (Taxodiaceae, which is well known as a “living fossil” species. In the Chinese folk medicine, the leaves and bark of M. glyptostroboides are used as antimicrobic, analgesic, and anti-inflammatory drug for dermatic diseases. This study is the first to report the free radical scavenging capacity, antioxidant activity, and proanthocyanidin composition of the bark of M. glyptostroboides. We observed total of six extracts and fractions, which were easily obtained by water-ethanol extraction and followed by a further separation with D101 resin column chromatography, had significant DPPH radical, superoxide anion radical, and hydroxyl radical scavenging capacity, total antioxidative capacity (T-AOC, lipid peroxidation inhibitory activity, and metal ions chelating capacity. The fraction MGEB, which was obtained by 60% ethanol extraction and followed by a further separation with D101 resin column chromatograph, possessed the highest proanthocyanidin content and the highest free radical scavenging and antioxidant activities. Furthermore, MGEB could significantly protect against CCl4 induced acute liver injury through inhibition of oxidative stress in mice. In addition, ten proanthocyanidins were isolated from MGEB, and six of them were firstly reported from this plant.

  7. Antioxidant Capacity and Metal Content of Physalis Peruviana L. Fruit Sold in Markets

    Directory of Open Access Journals (Sweden)

    Ayse Eken

    2014-12-01

    Full Text Available Aim: The dietary intake of medicinal food with antioxidant activity and required amounts of trace elements is important to pursue good healthy life. In our study, we aimed to determine the antioxidant capacity and metal content of goldenberry (Physalis peruviana L. fruit sold in markets in Kayseri. Material and Method: The antioxidant capacity of P. peruviana fruit was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH free radical scavenging assay. The DPPH radical scavenger capacity of the methanol extract of fruit was compared with known antioxidants such as ascorbic acid, gallic acid, and butylated hydroxytoluene (BHT as references. The metal content of P. peruviana fruit was measured by using atomic absorption spectrometer (AAS. Results: The fruit of P. peruviana was found to possess DPPH free radical scavenging activity but the antioxidant capacity was lower than the standard substances. Inhibitory concentration 50% (IC50 values of P. peruviana, ascorbic acid, gallic acid, and BHT were determined as 32 mg/ml, 3.8 mg/ml, 3.51 mg/ml, and 1.21 mg/ml, respectively. As a result of the analysis by AAS, it was observed that P. peruviana fruit contented plentiful trace elements and the content of heavy metal was small amount or not detected. Discussion: These observations suggest that the fruit of P. peruviana has a potential source of antioxidant and trace elements of natural origin.

  8. Flavonoids from Agrimonia pilosa Ledeb: Free Radical Scavenging and DNA Oxidative Damage Protection Activities and Analysis of Bioactivity-Structure Relationship Based on Molecular and Electronic Structures.

    Science.gov (United States)

    Zhu, Liancai; Chen, Jinqiu; Tan, Jun; Liu, Xi; Wang, Bochu

    2017-02-26

    To clarify the substantial basis of the excellent antioxidant capacity of Agrimonia pilosa Ledeb. Fourteen flavonoids were isolated and identified from Agrimonia pilosa Ledeb, seven of which have notable DPPH radical scavenging activities, i.e., catechin, luteolin, quercetin, quercitrin, hyperoside, rutin, luteolin-7- O -β-glucoside with IC 50 values of 5.06, 7.29, 4.36, 7.12, 6.34, 6.36 and 8.12 µM, respectively. The DNA nicking assay showed that five flavonoids from Agrimonia pilosa Ledeb-taxifolin, catechin, hyperoside, quercitrin and rutin-have good protective activity against DNA oxidative damage. Further, we analyzed the bioactivity-structure relationship of these 14 flavonoids by applying quantum theory. According to their O-H bond dissociation enthalpy (BDE), C ring's spin density and stable molecular structure, the relationship between their structures and radical scavenging capacities was evaluated and clarified. We found that among flavonoid aglycones from Agrimonia pilosa Ledeb, the O-H BDE of quercetin is lowest with the values of 69.02 and the O-H BDE of apigenin is highest with the values of 79.77. It is interesting that the O-H BDE value of isovitexin (78.55) with glycoside at C-6 position is lower than that of its aglycone (79.77) and vitexin (99.20) with glycoside at C-8 position. Further analysis indicated that the glycosidation of flavonoids at C-6 in the A-ring makes a more uniform distribution of spin density and improves the stability of free radicals leading to the increase in antioxidant capacity. Flavonoids with good antioxidant capacity might contribute to the pharmacological effects of Agrimonia pilosa Ledeb.

  9. Flavonoids from Agrimonia pilosa Ledeb: Free Radical Scavenging and DNA Oxidative Damage Protection Activities and Analysis of Bioactivity-Structure Relationship Based on Molecular and Electronic Structures

    Directory of Open Access Journals (Sweden)

    Liancai Zhu

    2017-02-01

    Full Text Available To clarify the substantial basis of the excellent antioxidant capacity of Agrimonia pilosa Ledeb. Fourteen flavonoids were isolated and identified from Agrimonia pilosa Ledeb, seven of which have notable DPPH radical scavenging activities, i.e., catechin, luteolin, quercetin, quercitrin, hyperoside, rutin, luteolin-7-O-β-glucoside with IC50 values of 5.06, 7.29, 4.36, 7.12, 6.34, 6.36 and 8.12 µM, respectively. The DNA nicking assay showed that five flavonoids from Agrimonia pilosa Ledeb—taxifolin, catechin, hyperoside, quercitrin and rutin—have good protective activity against DNA oxidative damage. Further, we analyzed the bioactivity-structure relationship of these 14 flavonoids by applying quantum theory. According to their O-H bond dissociation enthalpy (BDE, C ring’s spin density and stable molecular structure, the relationship between their structures and radical scavenging capacities was evaluated and clarified. We found that among flavonoid aglycones from Agrimonia pilosa Ledeb, the O-H BDE of quercetin is lowest with the values of 69.02 and the O-H BDE of apigenin is highest with the values of 79.77. It is interesting that the O-H BDE value of isovitexin (78.55 with glycoside at C-6 position is lower than that of its aglycone (79.77 and vitexin (99.20 with glycoside at C-8 position. Further analysis indicated that the glycosidation of flavonoids at C-6 in the A-ring makes a more uniform distribution of spin density and improves the stability of free radicals leading to the increase in antioxidant capacity. Flavonoids with good antioxidant capacity might contribute to the pharmacological effects of Agrimonia pilosa Ledeb.

  10. Capacity planning and management

    OpenAIRE

    Boydell, Briony

    2011-01-01

    After reading this chapter you should be able to: • Define and measure capacity and appreciate the factors that influence it. • Assess the difficulties of matching capacity to demand. • Evaluate and apply the different strategies for matching capacity with demand in the short, medium and long term. • Analyse the impact of constraints and bottlenecks on a process and consider the Theory of Constraints. • Outline the different strategies available for both manufacturing and service operations. ...

  11. Turbulent swirling flow in a dynamic model of a uniflow-scavenged two-stroke engine

    Science.gov (United States)

    Ingvorsen, K. M.; Meyer, K. E.; Walther, J. H.; Mayer, S.

    2014-06-01

    It is desirable to use computational fluid dynamics for optimization of the in-cylinder processes in low-speed two-stroke uniflow-scavenged marine diesel engines. However, the complex nature of the turbulent swirling in-cylinder flow necessitates experimental data for validation of the used turbulence models. In the present work, the flow in a dynamic scale model of a uniflow-scavenged cylinder is investigated experimentally. The model has a transparent cylinder and a moving piston driven by a linear motor. The flow is investigated using phase-locked stereoscopic particle image velocimetry (PIV) and time-resolved laser Doppler anemometry (LDA). Radial profiles of the phase-locked mean and rms velocities are computed from the velocity fields recorded with PIV, and the accuracy of the obtained profiles is demonstrated by comparison with reference LDA measurements. Measurements are carried out at five axial positions for 15 different times during the engine cycle and show the temporal and spatial development of the swirling in-cylinder flow. The tangential velocity profiles in the bottom of the cylinder near the end of the scavenge process are characterized by a concentrated swirl resulting in wake-like axial velocity profiles and the occurrence of a vortex breakdown. After scavenge port closing, the axial velocity profiles indicate that large transient swirl-induced structures exist in the cylinder. Comparison with profiles obtained under steady-flow conditions shows that the scavenge flow cannot be assumed to be quasi-steady. The temporal development of the swirl strength is investigated by computing the angular momentum. The swirl strength shows an exponential decay from scavenge port closing to scavenge port opening corresponding to a reduction of 34 %, which is in good agreement with theoretical predictions.

  12. Polyphenolic Compounds and Free Radical Scavenging Activity in Eight Lamiaceae Herbs of Manipur

    Directory of Open Access Journals (Sweden)

    Sandhyarani Devi KHOMDRAM

    2011-05-01

    Full Text Available Eight plants of Lamiaceae under subfamily Nepetoideae found in Manipur, India were selected for estimation of their polyphenolic compounds and free radical scavenging activity which is expressed on dry weight basis. In this present study, the total phenol and flavonoid contents as well as the free radical scavenging activity were studied using spectrophotometric method. The total phenol content was determined based on Folin-Ciocalteau reagent, flavonoid was determined by aluminium chloride spectrophotometric method and tannin by Folin Dennis Method. The free radical scavenging activity was determined by using DPPH radical which is expressed as IC50 (μg/ml. The total phenolic content varied from 21.39±0.927 to 46.28±0.543 mg/g, flavonoids content in the selected samples varied from 13.30±0.684 to 26.03±0.217 mg/g and tannin content varied from 8.72±0.160 to 17.04±0.206 mg/g. The free radical scavenging activity among the selected samples varied from 11.67±0.221 to 38.29±0.532 μg/ml. The correlation between the free radical scavenging activity with total phenol content (R2=0.511, with flavonoids (R2=0.241 and with tannin (R2=0.690 was calculated and maximum correlation value was found between tannin content and the free radical scavenging activity of the plant samples. The result supports that tannins were more responsible for free radical scavenging activity in the presently selected plants.

  13. The French capacity mechanism

    International Nuclear Information System (INIS)

    2014-01-01

    The French capacity mechanism has been design to ensure security of supply in the context of the energy transition. This energy transition challenges the electricity market design with several features: peak load growth, the development of renewables, demand response,... To ensure security of supply in this context, a capacity mechanism is being implemented in France. It is a market wide capacity obligation on electricity suppliers, based on market principles. Suppliers are responsible for forecasting their obligation, which corresponds to their contribution to winter peak load, and must procure enough capacity certificates to meet their obligations. Capacity certificates are granted to capacities through a certification process, which assesses their contribution to security of supply on the basis of availability commitments. This certification process is technology neutral and performance based, associated with controls and penalties in case of non compliance. Demand Side is fully integrated in the market, either through the reduction of suppliers' capacity obligation or direct participation after certification. In addition to the expected benefits in terms of security of supply, the French capacity market will foster the development of demand response. The participation of foreign capacities will require adaptations which are scheduled in a road-map, and could pave the way for further European integration of energy policies. (authors)

  14. Heat Capacity Analysis Report

    International Nuclear Information System (INIS)

    Findikakis, A.

    2004-01-01

    The purpose of this report is to provide heat capacity values for the host and surrounding rock layers for the waste repository at Yucca Mountain. The heat capacity representations provided by this analysis are used in unsaturated zone (UZ) flow, transport, and coupled processes numerical modeling activities, and in thermal analyses as part of the design of the repository to support the license application. Among the reports that use the heat capacity values estimated in this report are the ''Multiscale Thermohydrologic Model'' report, the ''Drift Degradation Analysis'' report, the ''Ventilation Model and Analysis Report, the Igneous Intrusion Impacts on Waste Packages and Waste Forms'' report, the ''Dike/Drift Interactions report, the Drift-Scale Coupled Processes (DST and TH Seepage) Models'' report, and the ''In-Drift Natural Convection and Condensation'' report. The specific objective of this study is to determine the rock-grain and rock-mass heat capacities for the geologic stratigraphy identified in the ''Mineralogic Model (MM3.0) Report'' (BSC 2004 [DIRS 170031], Table 1-1). This report provides estimates of the heat capacity for all stratigraphic layers except the Paleozoic, for which the mineralogic abundance data required to estimate the heat capacity are not available. The temperature range of interest in this analysis is 25 C to 325 C. This interval is broken into three separate temperature sub-intervals: 25 C to 95 C, 95 C to 114 C, and 114 C to 325 C, which correspond to the preboiling, trans-boiling, and postboiling regimes. Heat capacity is defined as the amount of energy required to raise the temperature of a unit mass of material by one degree (Nimick and Connolly 1991 [DIRS 100690], p. 5). The rock-grain heat capacity is defined as the heat capacity of the rock solids (minerals), and does not include the effect of water that exists in the rock pores. By comparison, the rock-mass heat capacity considers the heat capacity of both solids and pore

  15. Effect of superoxide anion scavenger on rat hearts with chronic intermittent hypoxia.

    Science.gov (United States)

    Pai, Peiying; Lai, Ching Jung; Lin, Ching-Yuang; Liou, Yi-Fan; Huang, Chih-Yang; Lee, Shin-Da

    2016-04-15

    Only very limited information regarding the protective effects of the superoxide anion scavenger on chronic intermittent hypoxia-induced cardiac apoptosis is available. The purpose of this study is to evaluate the effects of the superoxide anion scavenger on cardiac apoptotic and prosurvival pathways in rats with sleep apnea. Forty-two Sprague-Dawley rats were divided into three groups, rats with normoxic exposure (Control, 21% O2, 1 mo), rats with chronic intermittent hypoxia exposure (Hypoxia, 3-7% O2vs. 21% O2per 40 s cycle, 8 h per day, 1 mo), and rats with pretreatment of the superoxide anion scavenger and chronic intermittent hypoxia exposure (Hypoxia-O2 (-)-Scavenger, MnTMPyP pentachloride, 1 mg/kg ip per day; 3-7% O2vs. 21% O2per 40 s cycle, 8 h per day, 1 mo) at 5-6 mo of age. After 1 mo, the protein levels and apoptotic cells of excised hearts from three groups were measured by Western blotting and terminal deoxynucleotide transferase-mediated dUTP nick end labeling (TUNEL) assay. The superoxide anion scavenger decreased hypoxia-induced myocardial architecture abnormalities, left ventricular hypertrophy, and TUNEL-positive apoptosis. The superoxide anion scavenger decreased hypoxia-induced Fas ligand, Fas death receptors, Fas-associated death domain (FADD), activated caspase-8, and activated caspase-3 (Fas-dependent apoptotic pathway) as well as Bad, activated caspase-9 and activated caspase-3 (mitochondria-dependent apoptotic pathway), endonuclease G (EndoG), apoptosis-inducing factor (AIF), and TUNEL-positive apoptosis. The superoxide anion scavenger increased IGF-1, IGF-1R, p-PI3k, p-Akt, p-Bad, Bcl-2, and Bcl-xL (survival pathway). Our findings imply that the superoxide anion scavenger might prevent cardiac Fas-mediated and mitochondrial-mediated apoptosis and enhance the IGF-1-related survival pathway in chronic intermittent hypoxia. The superoxide anion scavenger may prevent chronic sleep apnea-enhanced cardiac apoptotic pathways and enhances

  16. Modelling the effect of boundary scavenging on Thorium and Protactinium profiles in the ocean

    Directory of Open Access Journals (Sweden)

    M. Roy-Barman

    2009-12-01

    Full Text Available The "boundary scavenging" box model is a cornerstone of our understanding of the particle-reactive radionuclide fluxes between the open ocean and the ocean margins. However, it does not describe the radionuclide profiles in the water column. Here, I present the transport-reaction equations for radionuclides transported vertically by reversible scavenging on settling particles and laterally by horizontal currents between the margin and the open ocean. Analytical solutions of these equations are compared with existing data. In the Pacific Ocean, the model produces "almost" linear 230Th profiles (as observed in the data despite lateral transport. However, omitting lateral transport biaises the 230Th based particle flux estimates by as much as 50%. 231Pa profiles are well reproduced in the whole water column of the Pacific Margin and from the surface down to 3000 m in the Pacific subtropical gyre. Enhanced bottom scavenging or inflow of 231Pa-poor equatorial water may account for the model-data discrepancy below 3000 m. The lithogenic 232Th is modelled using the same transport parameters as 230Th but a different source function. The main source of the 232Th scavenged in the open Pacific is advection from the ocean margin, whereas a net flux of 230Th produced in the open Pacific is advected and scavenged at the margin, illustrating boundary exchange. In the Arctic Ocean, the model reproduces 230Th measured profiles that the uni-dimensional scavenging model or the scavenging-ventilation model failed to explain. Moreover, if lateral transport is ignored, the 230Th based particle settling speed may by underestimated by a factor 4 at the Arctic Ocean margin. The very low scavenging rate in the open Arctic Ocean combined with the enhanced scavenging at the margin accounts for the lack of high 231Pa/230Th ratio in arctic

  17. Development of nitroxide radicals–containing polymer for scavenging reactive oxygen species from cigarette smoke

    International Nuclear Information System (INIS)

    Yoshitomi, Toru; Kuramochi, Kazuhiro; Binh Vong, Long; Nagasaki, Yukio

    2014-01-01

    We developed a nitroxide radicals–containing polymer (NRP), which is composed of poly(4-methylstyrene) possessing nitroxide radicals as a side chain via amine linkage, to scavenge reactive oxygen species (ROS) from cigarette smoke. In this study, the NRP was coated onto cigarette filters and its ROS-scavenging activity from streaming cigarette smoke was evaluated. The intensity of electron spin resonance signals of the NRP in the filter decreased after exposure to cigarette smoke, indicating consumption of nitroxide radicals. To evaluate the ROS-scavenging activity of the NRP-coated filter, the amount of peroxy radicals in an extract of cigarette smoke was measured using UV–visible spectrophotometry and 1,1-diphenyl-2-picrylhydrazyl (DPPH). The absorbance of DPPH at 517 nm decreased with exposure to cigarette smoke. When NRP-coated filters were used, the decrease in the absorbance of DPPH was prevented. In contrast, both poly[4-(cyclohexylamino)methylstyrene]- and poly(acrylic acid)-coated filters, which have no nitroxide radical, did not show any effect, indicating that the nitroxide radicals in the NRP scavenge the ROS in cigarette smoke. As a result, the extract of cigarette smoke passed through the NRP-coated filter has a lower cellular toxicity than smoke passed through poly[4-(cyclohexylamino)methylstyrene]- and poly(acrylic acid)-coated filters. Accordingly, NRP is a promising material for ROS scavenging from cigarette smoke. (papers)

  18. Invertebrates outcompete vertebrate facultative scavengers in simulated lynx kills in the Bavarian Forest National Park, Germany

    Directory of Open Access Journals (Sweden)

    Ray, R.–R.

    2014-06-01

    Full Text Available Understanding the role of scavengers in ecosystems is important for species conservation and wildlife management. We used road–killed animals, 15 in summer 2003 (June–August and nine in winter 2003/2004 (from November to January, to test the following hypotheses: (1 vertebrate scavengers such as raven (Corvus corax, red fox (Vulpes vulpes and wild boar (Sus scrofa consume a higher proportion of the carcasses than invertebrates; (2 the consumption rate is higher in winter than in summer due to the scarcity of other food resources; and (3 vertebrate scavengers are effective competitors of Eurasian lynx. We monitored 65 animals belonging to eight different mammal and bird species with camera traps. Surprisingly, Eurasian lynx (Lynx lynx was the most important vertebrate scavenger. However, in both seasons, the consumption of vertebrate scavengers was of minor impact. In summer, the carcasses were completely consumed within 10 days, mostly by invertebrates. In winter, only 5% of the carcasses were consumed within 10 days and 16% within 15 days. We conclude that vertebrates in the Bavarian Forest National Park are not strong competitors for lynx.

  19. Low frequency energy scavenging using sub-wave length scale acousto-elastic metamaterial

    Directory of Open Access Journals (Sweden)

    Riaz U. Ahmed

    2014-11-01

    Full Text Available This letter presents the possibility of energy scavenging (ES utilizing the physics of acousto-elastic metamaterial (AEMM at low frequencies (<∼3KHz. It is proposed to use the AEMM in a dual mode (Acoustic Filter and Energy Harvester, simultaneously. AEMM’s are typically reported for filtering acoustic waves by trapping or guiding the acoustic energy, whereas this letter shows that the dynamic energy trapped inside the soft constituent (matrix of metamaterials can be significantly harvested by strategically embedding piezoelectric wafers in the matrix. With unit cell AEMM model, we experimentally asserted that at lower acoustic frequencies (< ∼3 KHz, maximum power in the micro Watts (∼35µW range can be generated, whereas, recently reported phononic crystal based metamaterials harvested only nano Watt (∼30nW power against 10KΩ resistive load. Efficient energy scavengers at low acoustic frequencies are almost absent due to large required size relevant to the acoustic wavelength. Here we report sub wave length scale energy scavengers utilizing the coupled physics of local, structural and matrix resonances. Upon validation of the argument through analytical, numerical and experimental studies, a multi-frequency energy scavenger (ES with multi-cell model is designed with varying geometrical properties capable of scavenging energy (power output from ∼10µW – ∼90µW between 0.2 KHz and 1.5 KHz acoustic frequencies.

  20. Free radical scavenging and COX-2 inhibition by simple colon metabolites of polyphenols: A theoretical approach.

    Science.gov (United States)

    Amić, Ana; Marković, Zoran; Marković, Jasmina M Dimitrić; Jeremić, Svetlana; Lučić, Bono; Amić, Dragan

    2016-12-01

    Free radical scavenging and inhibitory potency against cyclooxygenase-2 (COX-2) by two abundant colon metabolites of polyphenols, i.e., 3-hydroxyphenylacetic acid (3-HPAA) and 4-hydroxyphenylpropionic acid (4-HPPA) were theoretically studied. Different free radical scavenging mechanisms are investigated in water and pentyl ethanoate as a solvent. By considering electronic properties of scavenged free radicals, hydrogen atom transfer (HAT) and sequential proton loss electron transfer (SPLET) mechanisms are found to be thermodynamically probable and competitive processes in both media. The Gibbs free energy change for reaction of inactivation of free radicals indicates 3-HPAA and 4-HPPA as potent scavengers. Their reactivity toward free radicals was predicted to decrease as follows: hydroxyl>alkoxyls>phenoxyl≈peroxyls>superoxide. Shown free radical scavenging potency of 3-HPAA and 4-HPPA along with their high μM concentration produced by microbial colon degradation of polyphenols could enable at least in situ inactivation of free radicals. Docking analysis with structural forms of 3-HPAA and 4-HPPA indicates dianionic ligands as potent inhibitors of COX-2, an inducible enzyme involved in colon carcinogenesis. Obtained results suggest that suppressing levels of free radicals and COX-2 could be achieved by 3-HPAA and 4-HPPA indicating that these compounds may contribute to reduced risk of colon cancer development. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Environment, urban poverty and scavenging: review of relationship and its effectiveness

    International Nuclear Information System (INIS)

    Chamhuri Siwar; Amzad Hossain; Norshamleeda Chamhuri

    2001-01-01

    Urban poverty and environment is interrelated to each other. Environmental degradation is a crucial factor for urban poverty and vice-versa. The generation of solid waste all over the world has reached an alarming proportion and constitutes one of the world's greatest sources of environmental degradation (fagan, 1974). Solid waste is one of the three major environmental problems faced by municipalities in Malaysia (World Bank, 1993) which is one of the major cause or contributor to urban poverty. However, urban solid waste consists of two strata such as source of environmental degradation and income generating agents for urban poor scavengers. In Malaysia, full-time and part-time scavengers are recycling 6% of total generated residential solid waste in some selected areas other wise its emitted or disposed to the environment. On the other hand, by doing this work full-time scavengers are earning wages of RM750 per month which is equal to that of the majority of Third world urbanities; part-time scavengers are earning 33% of their daily income. This paper discusses a theoretical framework of the relationship of environment and urban poverty. Policies, issues and some case studies of scavenging as a means of urban poverty reduction and environmental improvements of sustainable urban development are also explored. (Author)

  2. Human macrophage scavenger receptors: Primary structure, expression, and localization in atherosclerotic lesions

    International Nuclear Information System (INIS)

    Matsumoto, Akiyo; Itakura, Hiroshige; Kodama, Tatsuhiko; Naito, Makoto; Takahashi, Kiyoshi; Ikemoto, Shinji; Asaoka, Hitoshi; Hayakawa, Ikuho; Kanamori, Hiroshi; Takaku, Fumimaro; Aburatani, Hiroyuki; Suzuki, Hiroshi; Kobari, Yukage; Miyai, Tatsuya; Cohen, E.H.; Wydro, R.; Housman, D.E.

    1990-01-01

    Two types of cDNAs for human macrophage scavenger receptors were cloned from a cDNA library derived from the phorbol ester-treated human monocytic cell line THP-1. The type I and type II human scavenger receptors encoded by these cDNAs are homologous (73% and 71% amino acid identity) to their previously characterized bovine counterparts and consist of six domains: cytoplasmic (I), membrane-spanning (II), spacer (III), α-helical coiled-coil (IV), collagen-like (V), and a type-specific C-terminal (VI). The receptor gene is located on human chromosome 8. The human receptors expressed in CHO-K1 cells mediated endocytosis of modified low density lipoproteins. Two mRNAs, 4.0 and 3.2 kilobases, have been detected in human liver, placenta, and brain. Immunohistochemical studies using an anti-peptide antibody which recognizes human scavenger receptors indicated the presence of the scavenger receptors in the macrophages of lipid-rich atherosclerotic lesions, suggesting the involvement of scavenger receptors in atherogenesis

  3. Multi-dimensional scavenging analysis of a free-piston linear alternator based on numerical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Jinlong; Zuo, Zhengxing; Li, Wen; Feng, Huihua [School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081 (China)

    2011-04-15

    A free-piston linear alternator (FPLA) is being developed by the Beijing Institute of Technology to improve the thermal efficiency relative to conventional crank-driven engines. A two-stroke scavenging process recharges the engine and is crucial to realizing the continuous operation of a free-piston engine. In order to study the FPLA scavenging process, the scavenging system was configured using computational fluid dynamics. As the piston dynamics of the FPLA are different to conventional crank-driven two-stroke engines, a time-based numerical simulation program was built using Matlab to define the piston's motion profiles. A wide range of design and operating options were investigated including effective stroke length, valve overlapping distance, operating frequency and charging pressure to find out their effects on the scavenging performance. The results indicate that a combination of high effective stroke length to bore ratio and long valve overlapping distance with a low supercharging pressure has the potential to achieve high scavenging and trapping efficiencies with low short-circuiting losses. (author)

  4. Investigation of the chemistry of liquid H{sub 2}S scavengers

    Energy Technology Data Exchange (ETDEWEB)

    Buhaug, Janne Bjoerntvedt

    2002-07-01

    The production of natural gas in the North Sea is facing a growing problem: contamination of the natural gas with dihydrogen sulfide, H{sub 2}S. As a gas reservoir is emptied, seawater containing sulfates is pumped into it, and the sulfates are reduced to dihydrogen sulfide by sulfate-reducing bacteria. Dihydrogen sulfide is then pumped up along with the oil, gas and water from the reservoir, causing severe corrosion of pipelines and contamination of the final natural gas product. Dihydrogen sulfide is extremely toxic, and in fields with especially large concentrations of H{sub 2}S this is a severe health risk for the platform workers. Hence, it is desirable to remove the dihydrogen sulfide at the earliest stage possible. There are four main methods for removing H{sub 2}S from natural gas: (1) Liquid scavengers, (2) Solid scavengers, (3) Liquid redox processes, (4) Amine / Claus catalyst. Liquid scavengers are widely used in the natural gas industry, especially at sites with relatively low concentrations of H{sub 2}S. As a rule of thumb, liquid scavengers are economically favourable at sites with a removal of less than 50 kg/day of H{sub 2}S. This thesis is concerned with the cyclic amine 1,3,5 -tris(2-hydroxyethyl)-1,3,5-triazinane, often referred to as Triazine. This is used in fields with relatively low concentration of H{sub 2}S and dominates the liquid scavenger market.

  5. Demonstration of physical phenomenas and scavenging activity from d-psicose and methionine maillard reaction products

    Directory of Open Access Journals (Sweden)

    Arum Tiyas Suminar

    2017-01-01

    Full Text Available Maillard reaction has been well understood as a non-enzymatic reaction between reducing sugars and amino acids to generate the Maillard reaction products (MRPs. This study is aimed to demonstrate the browning intensity, color development, spectra measurements, scavenging activity, and the correlation between browning intensity and scavenging activity of the MRPs generated from D-Psicose and Methionine (Psi-Met at 50℃. The browning intensity of MRPs was investigated based on the absorbance using spectrophotometer at 420 nm, the color development was observed using digital colorimeter to gained L*a*b* value then calculated as browning index, the spectra development was analyzed using spectrophotometer at 190 - 750 nm, and the scavenging activity was determined with ABTS method using spectrophotometer at 734 nm. The browning intensity, color development, and scavenging activity were improved along with the increase in heating process. Based on spectra analysis, MRPs from Psi-Met was initially detected at 21 h and Psi at 24 h of heating treatment, which indicating that Psi-Met have faster and better reaction than Psi during heating process. Positive non-linear and significant correlation between browning intensity and scavenging activity were assigned. This finding may provide beneficial information of D-psicose and MRPs to the next scientific research and to the food industries which applies MRPs in their products.

  6. Increasing land-use intensity reverses the relative occupancy of two quadrupedal scavengers.

    Directory of Open Access Journals (Sweden)

    Joshua P Twining

    Full Text Available Human land use is continuously altering the natural environment, yet the greater ecological implications of this change for many groups that are key to healthy ecosystem functioning remains uncharacterised in the tropics. Terrestrial scavenging vertebrates are one such group, providing integral ecosystem services through the removal of carrion which is a crucial component of both nutrient cycling and disease dynamics. To explore how anthropogenic processes may affect forest scavengers, we investigated the changes in the relative occupancy of two important terrestrial scavengers along a gradient of land use intensity, ranging from protected forest to oil palm plantation in Borneo. We found the Malay civet (Viverra tangalunga had highest, albeit variable, occupancy in areas of low land use intensity and the Southeast Asian water monitor (Varanus salvator macromaculatus had highest occupancy in areas of high land use intensity. Land use had no effect on the combined occupancy of the two species. In high land use intensity sites, individual water monitors were larger and had better body condition, but at population level had a highly biased sex ratio with more males than females and increased signs of intraspecific conflict. We did not assess scavenging rate or efficiency as a process, but the high occupancy rates and apparent health of the scavengers in high land use intensity landscapes suggests this ecological process is robust to land use change.

  7. Changes in free-radical scavenging ability of kombucha tea during fermentation.

    Science.gov (United States)

    Jayabalan, R; Subathradevi, P; Marimuthu, S; Sathishkumar, M; Swaminathan, K

    2008-07-01

    Kombucha tea is a fermented tea beverage produced by fermenting sugared black tea with tea fungus (kombucha). Free-radical scavenging abilities of kombucha tea prepared from green tea (GTK), black tea (BTK) and tea waste material (TWK) along with pH, phenolic compounds and reducing power were investigated during fermentation period. Phenolic compounds, scavenging activity on DPPH radical, superoxide radical (xanthine-xanthine oxidase system) and inhibitory activity against hydroxyl radical mediated linoleic acid oxidation (ammonium thiocyanate assay) were increased during fermentation period, whereas pH, reducing power, hydroxyl radical scavenging ability (ascorbic acid-iron EDTA) and anti-lipid peroxidation ability (thiobarbituric assay) were decreased. From the present study, it is obvious that there might be some chances of structural modification of components in tea due to enzymes liberated by bacteria and yeast during kombucha fermentation which results in better scavenging performance on nitrogen and superoxide radicals, and poor scavenging performance on hydroxyl radicals. Copyright © 2007 Elsevier Ltd. All rights reserved.

  8. Prospects for OPEC capacity

    International Nuclear Information System (INIS)

    Adelman, M.A.

    1995-01-01

    OPEC capacity is not exogenous, but responds to demand. Price increases have not been caused by capacity shortages. OPEC nations find it hard to set aside even very small portions of their revenues for oil investment, despite its extreme profitability. Foreign investors face high risks. Production sharing makes their after-tax return even more unstable. (author)

  9. In vitro free radical scavenging activity of ethanolic extract of the whole plant of Evolvulus alsinoides (L.) L.

    Science.gov (United States)

    Gomathi, Duraisamy; Ravikumar, Ganesan; Kalaiselvi, Manokaran; Vidya, Balasubramaniam; Uma, Chandrasekar

    2015-06-01

    To identify the free radical scavenging activity of ethanolic extract of Evolvulus alsinoides. The free radical scavenging activity was evaluated by in vitro methods like reducing power assay, total antioxidant activity, 2,2-diphenyl-1-picrylhydrazyl (DPPH) reduction, superoxide radical scavenging activity, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(+)) scavenging activity, hydroxyl radical scavenging assay, and nitric oxide radical scavenging assay, which were studied by using ascorbic acid as standard. The extract showed significant activities in all antioxidant assays compared with the reference antioxidant ascorbic acid. The total antioxidant activity as well as the reducing power was also found to increase in a dose-dependent manner. Evolvulus alsinoides may act as a chemopreventive agent, providing antioxidant properties and offering effective protection from free radicals.

  10. Uncertainty in adaptive capacity

    International Nuclear Information System (INIS)

    Neil Adger, W.; Vincent, K.

    2005-01-01

    The capacity to adapt is a critical element of the process of adaptation: it is the vector of resources that represent the asset base from which adaptation actions can be made. Adaptive capacity can in theory be identified and measured at various scales, from the individual to the nation. The assessment of uncertainty within such measures comes from the contested knowledge domain and theories surrounding the nature of the determinants of adaptive capacity and the human action of adaptation. While generic adaptive capacity at the national level, for example, is often postulated as being dependent on health, governance and political rights, and literacy, and economic well-being, the determinants of these variables at national levels are not widely understood. We outline the nature of this uncertainty for the major elements of adaptive capacity and illustrate these issues with the example of a social vulnerability index for countries in Africa. (authors)

  11. Scavenging of peroxynitrite by phycocyanin and phycocyanobilin from Spirulina platensis: protection against oxidative damage to DNA.

    Science.gov (United States)

    Bhat, V B; Madyastha, K M

    2001-07-13

    Peroxynitrite (ONOO(-)) is known to inactivate important cellular targets and also mediate oxidative damage in DNA. The present study has demonstrated that phycocyanin, a biliprotein from spirulina platensis and its chromophore, phycocyanobilin (PCB), efficiently scavenge ONOO(-), a potent physiological inorganic toxin. Scavenging of ONOO(-) by phycocyanin and PCB was established by studying their interaction with ONOO(-) and quantified by using competition kinetics of pyrogallol red bleaching assay. The relative antioxidant ratio and IC(50) value clearly indicate that phycocyanin is a more efficient ONOO(-) scavenger than PCB. The present study has also shown that PCB significantly inhibits the ONOO(-)-mediated single-strand breaks in supercoiled plasmid DNA in a dose-dependent manner with an IC(50) value of 2.9 +/- 0.6 microM. These results suggest that phycocyanin, has the ability to inhibit the ONOO(-)-mediated deleterious biological effects and hence has the potential to be used as a therapeutic agent. Copyright 2001 Academic Press.

  12. Trypsin Binding with Copper Ions Scavenges Superoxide: Molecular Dynamics-Based Mechanism Investigation

    Directory of Open Access Journals (Sweden)

    Xin Li

    2018-01-01

    Full Text Available Trypsin is a serine protease, which has been proved to be a novel superoxide scavenger. The burst of superoxide induced by polychlorinated biphenyls can be impeded by trypsin in both wild type and sod knockout mutants of Escherichia coli. The experimental results demonstrated that the activities of superoxide scavenging of trypsin were significantly accelerated by Cu ions. Also, with the addition of Cu ions, a new β-sheet (β7 transited from a random coil in the Cu(II-trypsin (TP system, which was favorable for the formation of more contacts with other sheets of trypsin. Residue–residue network analysis and the porcupine plots proved that the Cu ion in trypsin strengthened some native interactions among residues, which ultimately resulted in much greater stability of the Cu(II-TP system. Moreover, compact and stable trypsin structures with Cu ions might be responsible for significantly provoking the activity of superoxide scavenging.

  13. Expression of NO scavenging hemoglobin is involved in the timing of bolting in Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Hebelstrup, Kim Henrik; Jensen, Erik Østergaard

    2008-01-01

    -symbiotic hemoglobin gene, GLB2, in Arabidopsis thaliana. Lines with GLB1 silencing had a significant delay of bolting and after bolting, shoots reverted to the rosette vegetative phase by formation of aerial rosettes at lateral meristems. Lines with overexpression of GLB1 or GLB2 bolted earlier than wild type plants....... By germinating the lines in a medium containing the nitric oxide (NO) donor, sodium nitroprusside (SNP), it was demonstrated that both GLB1 and GLB2 promote bolting by antagonizing the effect of NO, suggesting that non-symbiotic plant hemoglobin controls bolting by scavenging the floral transition signal...... molecule, NO. So far, NO scavenging has only been demonstrated for class 1 non-symbiotic hemoglobins. A direct assay in Arabidopsis leaf cells shows that GLB1 as well as the class 2 non-symbiotic hemoglobin, GLB2, scavenge NO in vivo. NO has also been demonstrated to be a growth stimulating signal...

  14. Antioxidant Capacity and Proanthocyanidin Composition of the Bark of Metasequoia glyptostroboides

    OpenAIRE

    Chen, Fengyang; Zhang, Lin; Zong, Shuling; Xu, Shifang; Li, Xiaoyu; Ye, Yiping

    2014-01-01

    Metasequoia glyptostroboides Hu et Cheng is the only living species in the genus Metasequoia Miki ex Hu et Cheng (Taxodiaceae), which is well known as a “living fossil” species. In the Chinese folk medicine, the leaves and bark of M. glyptostroboides are used as antimicrobic, analgesic, and anti-inflammatory drug for dermatic diseases. This study is the first to report the free radical scavenging capacity, antioxidant activity, and proanthocyanidin composition of the bark of M. glyptostroboid...

  15. Comparison of bee products based on assays of antioxidant capacities

    Directory of Open Access Journals (Sweden)

    Mishima Satoshi

    2009-02-01

    Full Text Available Abstract Background Bee products (including propolis, royal jelly, and bee pollen are popular, traditional health foods. We compared antioxidant effects among water and ethanol extracts of Brazilian green propolis (WEP or EEP, its main constituents, water-soluble royal jelly (RJ, and an ethanol extract of bee pollen. Methods The hydrogen peroxide (H2O2-, superoxide anion (O2·--, and hydroxyl radical (HO·- scavenging capacities of bee products were measured using antioxidant capacity assays that employed the reactive oxygen species (ROS-sensitive probe 5-(and-6-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate, acetyl ester (CM-H2DCFDA or aminophenyl fluorescein (APF. Results The rank order of antioxidant potencies was as follows: WEP > EEP > pollen, but neither RJ nor 10-hydroxy-2-decenoic acid (10-HDA had any effects. Concerning the main constituents of WEP, the rank order of antioxidant effects was: caffeic acid > artepillin C > drupanin, but neither baccharin nor coumaric acid had any effects. The scavenging effects of caffeic acid were as powerful as those of trolox, but stronger than those of N-acetyl cysteine (NAC or vitamin C. Conclusion On the basis of the present assays, propolis is the most powerful antioxidant of all the bee product examined, and its effect may be partly due to the various caffeic acids it contains. Pollen, too, exhibited strong antioxidant effects.

  16. Comparison of bee products based on assays of antioxidant capacities.

    Science.gov (United States)

    Nakajima, Yoshimi; Tsuruma, Kazuhiro; Shimazawa, Masamitsu; Mishima, Satoshi; Hara, Hideaki

    2009-02-26

    Bee products (including propolis, royal jelly, and bee pollen) are popular, traditional health foods. We compared antioxidant effects among water and ethanol extracts of Brazilian green propolis (WEP or EEP), its main constituents, water-soluble royal jelly (RJ), and an ethanol extract of bee pollen. The hydrogen peroxide (H2O2)-, superoxide anion (O2.-)-, and hydroxyl radical (HO.)- scavenging capacities of bee products were measured using antioxidant capacity assays that employed the reactive oxygen species (ROS)-sensitive probe 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate, acetyl ester (CM-H2DCFDA) or aminophenyl fluorescein (APF). The rank order of antioxidant potencies was as follows: WEP > EEP > pollen, but neither RJ nor 10-hydroxy-2-decenoic acid (10-HDA) had any effects. Concerning the main constituents of WEP, the rank order of antioxidant effects was: caffeic acid > artepillin C > drupanin, but neither baccharin nor coumaric acid had any effects. The scavenging effects of caffeic acid were as powerful as those of trolox, but stronger than those of N-acetyl cysteine (NAC) or vitamin C. On the basis of the present assays, propolis is the most powerful antioxidant of all the bee product examined, and its effect may be partly due to the various caffeic acids it contains. Pollen, too, exhibited strong antioxidant effects.

  17. Antioxidant capacity and phenolic acids of virgin coconut oil.

    Science.gov (United States)

    Marina, A M; Man, Y B Che; Nazimah, S A H; Amin, I

    2009-01-01

    The antioxidant properties of virgin coconut oil produced through chilling and fermentation were investigated and compared with refined, bleached and deodorized coconut oil. Virgin coconut oil showed better antioxidant capacity than refined, bleached and deodorized coconut oil. The virgin coconut oil produced through the fermentation method had the strongest scavenging effect on 1,1-diphenyl-2-picrylhydrazyl and the highest antioxidant activity based on the beta-carotene-linoleate bleaching method. However, virgin coconut oil obtained through the chilling method had the highest reducing power. The major phenolic acids detected were ferulic acid and p-coumaric acid. Very high correlations were found between the total phenolic content and scavenging activity (r=0.91), and between the total phenolic content and reducing power (r=0.96). There was also a high correlation between total phenolic acids and beta-carotene bleaching activity. The study indicated that the contribution of antioxidant capacity in virgin coconut oil could be due to phenolic compounds.

  18. OPEC future capacity expansions

    International Nuclear Information System (INIS)

    Sandrea, I.

    2005-01-01

    This conference presentation examined OPEC future capacity expansions including highlights from 2000-2004 from the supply perspective and actions by OPEC; OPEC spare capacity in 2005/2006; medium-term capacity expansion and investments; long-term scenarios, challenges and opportunities; and upstream policies in member countries. Highlights from the supply perspective included worst than expected non-OPEC supply response; non-OPEC supply affected by a number of accidents and strikes; geopolitical tensions; and higher than expected demand for OPEC crude. OPEC's actions included closer relationship with other producers and consumers; capacity expansions in 2004 and 2005/2006; and OPEC kept the market well supplied with crude in 2004. The presentation also provided data using graphical charts on OPEC net capacity additions until 2005/2006; OPEC production versus spare capacity from 2003 to 2005; OPEC production and capacity to 2010; and change in required OPEC production from 2005-2020. Medium term expansion to 2010 includes over 60 projects. Medium-term risks such as project execution, financing, costs, demand, reserves, depletion, integration of Iraq, and geopolitical tensions were also discussed. The presentation concluded that in the long term, large uncertainties remain; the peak of world supply is not imminent; and continued and enhanced cooperation is essential to market stability. tabs., figs

  19. Tourism in protected areas: Disentangling road and traffic effects on intra-guild scavenging processes.

    Science.gov (United States)

    Donázar, José Antonio; Ceballos, Olga; Cortés-Avizanda, Ainara

    2018-07-15

    The expansion of road networks and the increase in traffic have emerged in recent years as key threats to the conservation of biodiversity. This is particularly concerning in many protected areas because the increase of recreational activities requiring the use of vehicles. Effects of roads and traffic within guild scenarios and ecological processes remain however poorly known. Here we examined how road proximity and traffic intensity influence patterns of resource use in an Old-World avian scavenger guild living in a protected natural park in northern Spain. We experimentally placed 130 carcasses at different distances from a scenic road in the centre of the park. Vehicles were recorded by means of traffic counters which revealed that maximum numbers were reached during weekends and holidays and during the middle hours of the day. Avian scavenger attendance at carcasses was recorded by means of camera-traps. Obligated scavengers, Eurasian griffon (Gyps fulvus) and Egyptian vultures (Neophron percnopterus) were frequently observed (59.4% and 37.7% of the consumed carcasses) together with five other facultative scavenger species. We found that the richness (number of species) and the probability of consumption of the resource were reduced the smaller the distance to the road and in days with higher traffic intensity. The same factors affected the probability of presence of all the scavenger species. Moreover, some of them, notably griffon vultures, showed hourly patterns of carcass attendance suggesting avoidance of maximum traffic levels. Our results highlight that roads and traffic would trigger consequences on the structure and functioning of scavenger food webs, which may be particularly concerning in protected areas with remarkable levels of biodiversity. Future regulations at protected areas should couple both traffic and tourist affluence with wildlife conservation. In this way important ecological processes would be preserved while maintaining a good

  20. The scavenging of volatile anesthetic agents in the cardiovascular intensive care unit environment: a technical report.

    Science.gov (United States)

    Pickworth, Thomas; Jerath, Angela; DeVine, Rita; Kherani, Nazmin; Wąsowicz, Marcin

    2013-01-01

    The use of volatile-based sedation within critical care environments has been limited by difficulties of drug administration and safety concerns over environment pollution and staff exposure in an intensive care unit (ICU) with no scavenging. The aim of this study was to develop a simple scavenging system to be used with the Anesthesia Conserving Device (AnaConDa(®)) and to determine whether or not ambient concentrations of residual anesthetic are within current acceptable limits. The scavenging system consists of two Deltasorb(®) canisters attached to the ICU ventilator in series. AnaConDa is a miniature vaporizer designed to provide volatile-based sedation within an ICU. The first ten patients recruited into a larger randomized trial assessing outcomes after elective coronary graft bypass surgery were sedated within the cardiac ICU using either isoflurane or sevoflurane. Sedation was guided by the Sedation Agitation Scale, resulting in an end-tidal minimum anesthetic concentration of volatile agent ranging from 0.1-0.3. At one hour post ICU admission, infrared photometric analysis was used to assess environmental contamination at four points along the ventilator circuit and scavenging system and around the patient's head. All measurements taken within the patient's room were below 1 part per million, which satisfies criteria for occupational exposure. This study shows that volatile agents can be administered safely within critical care settings using a simple scavenging system. Our scavenging system used in conjunction with the AnaConDa device reduced the concentration of environmental contamination to a level that is acceptable to Canadian standards and standards in most Western countries and thus conforms to international safety standards. The related clinical trial was registered at www.clinicaltrials.gov (NCT01151254).

  1. Analysis of the Scavenging Process of a Two-Stroke Free-Piston Engine Based on the Selection of Scavenging Ports or Valves

    Directory of Open Access Journals (Sweden)

    Boru Jia

    2018-02-01

    Full Text Available The free-piston engine generator (FPEG is a linear energy conversion device with the objective of utilisation within a hybrid-electric automotive vehicle power system. In this research, the piston dynamic characteristics of an FPEG is compared with that of a conventional engine (CE of the same size, and the difference in the valve timing is compared for both port scavenging type and valve scavenging type, with the exhaust valve closing timing is selected as the parameter. A zero-dimensional simulation model is developed in Ricardo WAVE software (2016.1, with the piston dynamics obtained from the simulation model in Matlab/SIMULINK (R2017a. For the CE and FEPG using scavenging ports, in order to improve its power output to the same level as that of a CE, the inlet gas pressure is suggested to be improved to above 1.2 bar, approximately 0.2 bar higher than that used for a CE. If a CE cylinder with exhaust valves is adopted or referred to during the development of an FPEG prototype, the exhaust valve is suggested to be closed earlier to improve its power output, and a higher intake pressure is also suggested if its output power is expected to be the same or higher than that of a CE.

  2. Vedr.: Military capacity building

    DEFF Research Database (Denmark)

    Larsen, Josefine Kühnel; Struwe, Lars Bangert

    2013-01-01

    Military capacity building has increasingly become an integral part of Danish defence. Military capacity is a new way of thinking Danish defence and poses a new set of challenges and opportunities for the Danish military and the Political leadership. On the 12th of december, PhD. Candidate Josefine...... Kühnel Larsen and researcher Lars Bangert Struwe of CMS had organized a seminar in collaboration with Royal Danish Defense Colleg and the East African Security Governance Network. The seminar focused on some of the risks involved in Military capacity building and how these risks are dealt with from...

  3. Turbulent swirling flow in a dynamic model of a uniflow-scavenged two-stroke engine

    DEFF Research Database (Denmark)

    Ingvorsen, Kristian Mark; Meyer, Knud Erik; Walther, Jens Honore

    2014-01-01

    turbulence models. In the present work, the flow in a dynamic scale model of a uniflowscavenged cylinder is investigated experimentally. The model has a transparent cylinder and a moving piston driven by a linear motor. The flow is investigated using phase-locked stereoscopic particle image velocimetry (PIV...... cannot be assumed to be quasi-steady. The temporal development of the swirl strength is investigated by computing the angular momentum. The swirl strength shows an exponential decay from scavenge port closing to scavenge port opening corresponding to a reduction of 34 %, which is in good agreement...

  4. The Prohibition of Employment as Manual Scavengers and their Rehabilitation Act, 2013: A Review

    Directory of Open Access Journals (Sweden)

    Aparajita Baruah

    2014-02-01

    Full Text Available Manual scavenging is a caste-based and hereditary occupation for Dalits (untouchables, which is predominantly linked with forced labour or slavery. In this article, an attempt has been made to trace out the brief history of the practice of manual scavenging in India. The author has also dwelt upon the constitutional commitment as well as measures taken up by the successive governments to improve the conditions of this class of people. The hallmark of the article lies in the detailed analysis along with some suitable suggestions on the Prohibition of Employment as Manual Scav- engers and their Rehabilitation Act, 2013 recently enacted by the Parliament of India.

  5. Protective role of OH scavengers and DNA/chromatin organization in the induction of DNA breaks: mechanistic models and Monte Carlo simulations

    International Nuclear Information System (INIS)

    Ballarini, F.; Rossetti, M.; Scannicchio, D.; Jacob, P.; Molinelli, S.; Ottolenghi, A.; Volata, A.

    2003-01-01

    Radiation-induced DNA damage can be modulated by various factors, including the environment scavenging capacity (SC) and the DNA organization within the cell nucleus (chromatin compactness, DNA-binding proteins etc.). In this context the induction of ssb and dsb by photons and light ions of different energies impinging on different DNA structures (e.g. linear DNA, SV40 'minichromosomes' and cellular DNA) at different OH-radical SC values was modelled with the Monte Carlo PARTRAC code. Presently PARTRAC can transport electrons, photons, protons and alpha particles in liquid water with an 'event-by-event' approach, and can simulate the DNA content of mammalian cells with an 'atom-by-atom' description, from nucleotide pairs to chromatin fibre loops and chromosome territories. Energy depositions in the sugar-phosphate were considered as potential (direct) ssb. The production, diffusion and reaction of chemical species were explicitly simulated; reactions of OH radicals with the sugar-phosphate were assumed to lead to 'indirect' ssb with probability 65%. Two ssb on opposite strands within 10 bp were considered as a dsb. Yields of ssb and dsb/Gy/Dalton were calculated for different DNA structures as a function of the OH mean life time. By Zyuzikov, N.; Michael, B.D. (Gray Cancer Institute, (GB)); Wu, L. (Ch Zyuzdirect damage yields. In general, also depending on radiation quality, linear DNA was found to be more susceptible to strand breakage than SV40 minichromosomes, which in turn showed higher damage yields with respect to cellular DNA. The very good agreement found with available experimental data provided a validation of the model and allowed us to quantify separately the protective effect of OH scavengers and DNA/chromatin organization. Comparisons with data on nucleoids (DNA unfolded and depleted of histones) suggested that the experimental procedures used to obtain such targets might lower the environment SC, due to the loss of cellular scavenging compounds

  6. In vitro antioxidant properties, free radicals scavenging activities of extracts and polyphenol composition of a non-timber forest product used as spice: Monodora myristica

    Directory of Open Access Journals (Sweden)

    Bruno Moukette Moukette

    2015-01-01

    Full Text Available BACKGROUND: Excessive production of free radicals causes direct damage to biological molecules such as DNA, proteins, lipids, carbohydrates leading to tumor development and progression. Natural antioxidant molecules from phytochemicals of plant origin may directly inhibit either their production or limit their propagation or destroy them to protect the system. In the present study, Monodora myristica a non-timber forest product consumed in Cameroon as spice was screened for its free radical scavenging properties, antioxidant and enzymes protective activities. Its phenolic compound profile was also realized by HPLC. RESULTS: This study demonstrated that M. myristica has scavenging properties against DPPH',OH',NO', and ABTS'radicals which vary in a dose depending manner. It also showed an antioxidant potential that was comparable with that of Butylated Hydroxytoluene (BHT and vitamin C used as standard. The aqueous ethanol extract of M. myristica barks (AEH; showed a significantly higher content in polyphenolic compounds (21.44 ±0.24 mg caffeic acid/g dried extract and flavonoid (5.69 ± 0.07 quercetin equivalent mg/g of dried weight as compared to the other studied extracts. The HPLC analysis of the barks and leaves revealed the presence of several polyphenols. The acids (3,4-OH-benzoic, caffeic, gallic, O- and P- coumaric, syringic, vanillic, alcohols (tyrosol and OH-tyrosol, theobromine, quercetin, rutin, catechine and apigenin were the identified and quantified polyphenols. All the tested extracts demonstrated a high protective potential on the superoxide dismutase (SOD, catalase and peroxidase activities. CONCLUSION: Finally, the different extracts from M. myristica and specifically the aqueous ethanol extract reveal several properties such as higher free radical scavenging properties, significant antioxidant capacities and protective potential effects on liver enzymes.

  7. Effect of Microwave-Assisted Extraction on the Phenolic Compounds and Antioxidant Capacity of Blackthorn Flowers.

    Science.gov (United States)

    Lovrić, Vanja; Putnik, Predrag; Kovačević, Danijela Bursać; Jukić, Marijana; Dragović-Uzelac, Verica

    2017-06-01

    This research was undertaken to investigate the influence of extraction parameters during microwave-assisted extraction on total phenolic content, total flavonoids, total hydroxycinnamic acids and total flavonols of blackthorn flowers as well as to evaluate the antioxidant capacity by two different methods (2,2-diphenyl-1-picrylhydrazyl free radical scavenging capacity and ferric reducing antioxidant power assays). The investigated extraction parameters were: solvent type and volume fraction of alcohol in solvent (50 and 70% aqueous solutions of ethanol and methanol), extraction time (5, 15 and 25 min) and extraction temperature (40, 50 and 60 °C) controlled by microwave power of 100, 200 and 300 W. Multivariate analysis of variance (MANOVA) was used to evaluate the differences at a 95% confidence level (p≤0.05). The obtained results show that aqueous solution of ethanol was more appropriate solvent for extraction of phenolic compounds (total flavonoids, total hydroxycinnamic acids and total flavonols) than aqueous solution of methanol. The amount of phenolic compounds was higher in 70% aqueous solution of ethanol or methanol, while higher antioxidant capacity was observed in 50% aqueous solution of methanol. Higher temperature of extraction improved the amount of phenolic compounds and also antioxidant capacity determined by 2,2-diphenyl-1-picrylhydrazyl free radical scavenging capacity assay. Extensive duration of extraction (15- to 25-minute interval) has a significant effect only on the increase of total phenolic content, while specific phenolic compound content and antioxidant capacity were the highest when microwave extraction time of 5 min was applied.

  8. Evaluating Capacity Development

    International Development Research Centre (IDRC) Digital Library (Canada)

    She also had the dubious pleasure of checking and correcting the text numerous ... Has your organization received training or other types of support for capacity ...... processors, and consumer groups in its research and development work.

  9. Revisiting Absorptive Capacity

    DEFF Research Database (Denmark)

    de Araújo, Ana Luiza Lara; Ulhøi, John Parm; Lettl, Christopher

    Absorptive capacity has mostly been perceived as a 'passive' outcome of R&D investments. Recently, however, a growing interest into its 'proactive' potentials has emerged. This paper taps into this development and proposes a dynamic model for conceptualizing the determinants of the complementary...... learning processes of absorptive capacity, which comprise combinative and adaptive capabilities. Drawing on survey data (n=169), the study concludes that combinative capabilities primarily enhance transformative and exploratory learning processes, while adaptive capabilities strengthen all three learning...

  10. Influences of in-cloud aerosol scavenging parameterizations on aerosol concentrations and wet deposition in ECHAM5-HAM

    Directory of Open Access Journals (Sweden)

    B. Croft

    2010-02-01

    Full Text Available A diagnostic cloud nucleation scavenging scheme, which determines stratiform cloud scavenging ratios for both aerosol mass and number distributions, based on cloud droplet, and ice crystal number concentrations, is introduced into the ECHAM5-HAM global climate model. This scheme is coupled with a size-dependent in-cloud impaction scavenging parameterization for both cloud droplet-aerosol, and ice crystal-aerosol collisions. The aerosol mass scavenged in stratiform clouds is found to be primarily (>90% scavenged by cloud nucleation processes for all aerosol species, except for dust (50%. The aerosol number scavenged is primarily (>90% attributed to impaction. 99% of this impaction scavenging occurs in clouds with temperatures less than 273 K. Sensitivity studies are presented, which compare aerosol concentrations, burdens, and deposition for a variety of in-cloud scavenging approaches: prescribed fractions, a more computationally expensive prognostic aerosol cloud processing treatment, and the new diagnostic scheme, also with modified assumptions about in-cloud impaction and nucleation scavenging. Our results show that while uncertainties in the representation of in-cloud scavenging processes can lead to differences in the range of 20–30% for the predicted annual, global mean aerosol mass burdens, and near to 50% for accumulation mode aerosol number burden, the differences in predicted aerosol mass concentrations can be up to one order of magnitude, particularly for regions of the middle troposphere with temperatures below 273 K where mixed and ice phase clouds exist. Different parameterizations for impaction scavenging changed the predicted global, annual mean number removal attributed to ice clouds by seven-fold, and the global, annual dust mass removal attributed to impaction by two orders of magnitude. Closer agreement with observations of black carbon profiles from aircraft (increases near to one order of magnitude for mixed phase clouds

  11. Consumption of Big Game Remains by Scavengers: A Potential Risk as Regards Disease Transmission in Central Spain

    Directory of Open Access Journals (Sweden)

    Ricardo Carrasco-Garcia

    2018-03-01

    Full Text Available Understanding the role that facultative scavenger species may play in spreading infectious pathogens, and even becoming reservoirs for humans, domestic and wild ungulates or, on the contrary, preventing the spread of disease, requires a prior understanding of the pattern of carrion scavenging in specific scenarios. The objectives of this paper are (i to describe the guild of vertebrate scavengers and (ii to study the species-specific, habitat, and management-related factors involved in the usage of gut piles in South Central Spain (SCS, a tuberculosis (TB endemic area. We used camera trapping at 18 hunting piles on seven hunting estates. A total of eight bird and five mammal taxa were detected at the remains of hunting piles. The most frequently detected species in terms of number of gut piles visited (78% and scavenged (61% was the red fox Vulpes vulpes, followed by the griffon vulture Gyps fulvus (56% as regards both presence and scavenging and the raven Corvus corax (61 and 39% as regards presence and scavenging, respectively. We evidenced that griffon vultures accounted for most of the scavenging activity in open habitats, while facultative mammal scavengers, red fox, and wild boar Sus scrofa made the highest contribution to scavenging in vegetation-covered habitats. In the case of wild boar, the gut piles deposited during the evening and night favored higher rates of scavenging, while the opposite pattern was observed for griffons. Overall, our findings suggest that when disposing of hunting remains in areas of risk as regards disease transmission it is particularly important to consider the access that facultative mammals, and especially wild boar, have to material, while the presence of the resource needs to be safeguarded to protect specialist scavengers of conservation value. These results are of particular relevance in the case of wild boar in the current context of re-emerging TB and emerging African swine fever (ASF in Europe.

  12. Changes in the amino acid profiles and free radical scavenging activities of Tenebrio molitor larvae following enzymatic hydrolysis.

    Science.gov (United States)

    Tang, Yujiao; Debnath, Trishna; Choi, Eun-Ju; Kim, Young Wook; Ryu, Jung Pyo; Jang, Sejin; Chung, Sang Uk; Choi, Young-Jin; Kim, Eun-Kyung

    2018-01-01

    Tenebrio molitor (T. molitor) larvae provide food at low environmental cost and contribute positively to livelihoods. In this research, we compared the amino acids compositions and antioxidant activities of various extracts of T. molitor to enhance their quality as food. For the comparison, distilled water extracts, enzymatic hydrolysates, and condensed enzymatic hydrolysates of T. molitor larvae were prepared. Their amino acids (AAs) profiles and antioxidant activities, including ferric-reducing antioxidant power, oxygen radical absorption capacity, and DPPH, hydroxyl radical, and hydrogen peroxide radical scavenging properties assay were analyzed. DW extracts had the lowest AAs contents and antioxidant activity compared with enzymatic extracts. Condensed hydrolysates with a combination of alcalase and flavourzyme (C-A+F) exhibited the highest levels of total free AAs (11.1759 g/100 g). C-A+F produced higher total hydrolyzed AAs (32.5292 g/100 g) compared with the other groups. The C-A+F possessed the strongest antioxidant activity. Notably, the antioxidant activities of the hydrolysates and the total hydrolyzed AAs amount were correlated. Taken together, our findings showed that C-A+F was a promising technique for obtaining extracts of T. molitor larvae with antioxidant activity as potential nutritious functional food.

  13. Assessment of radical scavenging, whitening and moisture retention activities of Panax ginseng berry mediated gold nanoparticles as safe and efficient novel cosmetic material.

    Science.gov (United States)

    Jiménez, Zuly; Kim, Yeon-Ju; Mathiyalagan, Ramya; Seo, Kwang-Hoon; Mohanan, Padmanaban; Ahn, Jong-Chan; Kim, Yu-Jin; Yang, Deok Chun

    2018-03-01

    Panax ginseng berry extract possess remarkable pharmacological effects on skin treatment such as anti-aging, antioxidant, promotor of collagen synthesis and alleviation against atopic dermatitis. In recent years, gold nanoparticles have gained much attention due to their extensive range of applications in particular in the field of drug delivery as a result of their biological compatibility and low toxicity. In a previous study, we designed and developed biocompatible gold and silver nanoparticles based on phytochemical profile and pharmacological efficacy of P. ginseng berry extract, we were able to reduce gold ions to nanoparticles through the process of green synthesis. However, its potential as a cosmetic ingredient is still unexplored. The aim of the present study is to investigate the moisture retention, in-vitro scavenging and whitening properties of gold nanoparticles synthesized from P. ginseng berry in cosmetic applications. Our findings confirm that P. ginseng berry mediated gold nanoparticles exhibited moisture retention capacity. In addition, MTT assay results confirmed that P. ginseng berry mediated gold nanoparticles are non-toxic to human dermal fibroblast and murine melanoma skin cells, possess scavenging activity, protect and provide alleviation against injured caused by H 2 O 2 -induced damage. In addition, P. ginseng berry mediated gold nanoparticles, significantly reduced melanin content and suppress tyrosinase activity in α-MSH-stimulated B16BL6 cells. We conclude that P. ginseng berry mediated gold nanoparticles are biocompatible and environmental affable materials and can be a potential novel cosmetic ingredient.

  14. Lipid organics in background aerosols, cloudwater, and snow and implication for organic scavenging

    International Nuclear Information System (INIS)

    Groellert, C.

    1998-01-01

    During three years free tropospheric snow, aerosol, and cloudwater samples were collected at Mount Sonnblick, Austria, at an elevation of 3106 m a.s.l. The samples were analyzed for their lipid organic trace components using extraction with n-hexane as sample pretreatment and gas chromatography-mass spectrometry-flame ionization detection for identification and quantification of the substances. The main components identified in all the samples were the phthalic acid esters which are of anthropogenic origin. Of further interest were aliphatic alcohols (not detected in aerosols) and phenols. They are of biogenic origin. The concentrations were found to be higher in spring than in the fall season. To compare the concentrations of aerosol, cloudwater and snow samples scavenging ratios (aerosol to snow), scavenging efficiencies (aerosol to cloud) and cloud to snow ratios were calculated for the first time for organic compounds. Scavenging ratios were 10 to 100 times lower, scavenging efficiencies 2 to 10 times lower than sulfate. This can result from the poor watersolubility of the compounds or from gas phase sorptions on the filter surface (overestimation of aerosol concentrations). The cloud to snow ratios were generally higher than for sulfate. However, a few components exhibited very low cloud to snow ratios which might be due to additional sources in snow for these substances (alcohols). (author)

  15. Evaluation of antioxidant, free radical scavenging and antimicrobial, activity of Quercus incana Roxb.

    Directory of Open Access Journals (Sweden)

    Rizwana eSarwar

    2015-11-01

    Full Text Available Considering the indigenous utilization of Quercus incana Roxb., the present study deals with the investigation of antioxidant, free radical scavenging activity, total phenolic content and antimicrobial activity of Quercus incana Roxb. In vitro antioxidant activity of the plant fractions were determined by DPPH and NO scavenging method. Total phenolic contents were determined by gallic acid equivalent (GAE and antimicrobial activities were determined by agar well diffusion method. It was observed that Quercus incana Roxb. showed significant antibacterial activity against Gram-positive and Gram-negative bacteria. n-Butanol fraction showed maximum activity against Micrococcus leuteus with 19 mm zone of inhibition. n-Butanol fraction of Quercus incana Roxb. showed immense antifungal activity against Aspergillus niger (32 mm ± 0.55 and Aspergillus flavus (28 mm ± 0.45. Similarly n-butanol fraction showed relatively good antioxidant activity with IC50 value of 55.4 ± 0.21μg/mL. The NO scavenging activity of ethyl acetate fraction (IC50 = 23.21 ± 0.31 μg/mL was fairly good compared to other fractions. The current study of Quercus incana Roxb. suggests the presences of synergetic action of some biological active compounds that may be present in the leaves of medicinal plant. Further studies are needed to better characterize the important active constituents responsible for the antimicrobial, antioxidant and free radical scavenging activity.

  16. Variation in bird-window collision mortality and scavenging rates within an urban landscape

    Science.gov (United States)

    Annual avian mortality from collisions with windows and buildings is estimated to range from a million to a billion birds in the United States alone. However, estimates of mortality based on carcass counts suffer from bias due to imperfect detection and carcass scavenging. We stu...

  17. 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...

  18. Extraction and free radical scavenging activity of polysaccharide from 'Anji Baicha' (Camellia sinensis (L.) O. Kuntze).

    Science.gov (United States)

    Zhang, Zhongshan; Wang, Xiaomei; Li, Jingfen; Wang, Guozhi; Mao, Genxiang

    2016-03-01

    In this study, the optimization of the extraction conditions of polysaccharide from 'Anji Baicha' (Camellia sinensis (L.) O. Kuntze) (AP) was investigated by response surface methodology (RSM). Three main independent variables (extraction temperature, time, ratio of water to raw material) were taken into consideration. And then the free radical scavenging activities of the sample were investigated including scavenging effects of superoxide and hydroxyl radicals. The RSM analysis showed good correspondence between experimental and predicted values.. The optimal condition to obtain the highest yield of AP was determined as follows: temperature 76.79 °C, time 2.48 h, ratio of water to material 22.53 mL/g. For the free radical scavenging activity, the IC50 values of Vc and AP were 7.78 and 83.25 μg/mL. And for the scavenging effect on hydroxyl radical, that of AP and Vc were 1.80 and 1.69 mg/mL. AP showed excellent antioxidant activity. This exhibited AP had a good potential for antioxidant. The purification and structure needs to be study in further. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Control-Oriented Model of Molar Scavenge Oxygen Fraction for Exhaust Recirculation in Large Diesel Engines

    DEFF Research Database (Denmark)

    Nielsen, Kræn Vodder; Blanke, Mogens; Eriksson, Lars

    2016-01-01

    the behavior of the scavenge oxygen fraction well over the entire envelope of load and blower speed range that are relevant for EGR. The simplicity of the new model makes it suitable for observer and control design, which are essential steps to meet the emission requirements for marine diesel engines that take...

  20. A new class of free radical scavengers reducing adriamycin mitochondrial toxicity

    NARCIS (Netherlands)

    Praet, M.; Calderon, P. B.; Pollakis, G.; Roberfroid, M.; Ruysschaert, J. M.

    1988-01-01

    Beef heart mitochondria were incubated with ADM and NADH. An adriamycin semiquinone radical was detected using ESR spectroscopy. The semiquinone radical production rate is decreased upon addition of a scavenger (AD 20) in the reaction medium. NMRI mice were treated with AD 20 (70 mg/kg, i.p.) 15 min

  1. CFD analysis of the scavenging process in marine two-stroke diesel engines

    DEFF Research Database (Denmark)

    Andersen, Fredrik Herland; Hult, Johan; Nogenmyr, Karl-Johan

    2014-01-01

    /charge before the subsequent compression stroke. This implies that the scavenging process is integral to engine performance as it influence the initial condition for the combustion process, thus affecting the fuel economy, power output and emission of hazardous gases. Two-stroke diesel engines for marine...

  2. Radiation inactivation analysis of enzymes. Effect of free radical scavengers on apparent target sizes

    International Nuclear Information System (INIS)

    Eichler, D.C.; Solomonson, L.P.; Barber, M.J.; McCreery, M.J.; Ness, G.C.

    1987-01-01

    In most cases the apparent target size obtained by radiation inactivation analysis corresponds to the subunit size or to the size of a multimeric complex. In this report, we examined whether the larger than expected target sizes of some enzymes could be due to secondary effects of free radicals. To test this proposal we carried out radiation inactivation analysis on Escherichia coli DNA polymerase I, Torula yeast glucose-6-phosphate dehydrogenase, Chlorella vulgaris nitrate reductase, and chicken liver sulfite oxidase in the presence and absence of free radical scavengers (benzoic acid and mannitol). In the presence of free radical scavengers, inactivation curves are shifted toward higher radiation doses. Plots of scavenger concentration versus enzyme activity showed that the protective effect of benzoic acid reached a maximum at 25 mM then declined. Mannitol alone had little effect, but appeared to broaden the maximum protective range of benzoic acid relative to concentration. The apparent target size of the polymerase activity of DNA polymerase I in the presence of free radical scavengers was about 40% of that observed in the absence of these agents. This is considerably less than the minimum polypeptide size and may reflect the actual size of the polymerase functional domain. Similar effects, but of lesser magnitude, were observed for glucose-6-phosphate dehydrogenase, nitrate reductase, and sulfite oxidase. These results suggest that secondary damage due to free radicals generated in the local environment as a result of ionizing radiation can influence the apparent target size obtained by this method

  3. Radical-scavenging-linked antioxidant activities of extracts from black chokeberry and blueberry cultivated in Korea.

    Science.gov (United States)

    Hwang, Seok Joon; Yoon, Won Byong; Lee, Ok-Hwan; Cha, Seung Ju; Kim, Jong Dai

    2014-03-01

    The objective of this study was to investigate the radical-scavenging-linked antioxidant properties of the extracts from black chokeberry and blueberry cultivated in Korea. The 70% ethanol extracts were prepared from black chokeberry and blueberry, and evaluated for total phenolic content, total flavonoid content, total proanthocyanidin content, and antioxidative activities, using various in vitro assays, such as DPPH(2,2-diphenyl-1-picrylhydrazyl), ABTS(2,2-azino-bis-(3-ethylenebenzothiozoline-6-sulphonic acid)) radical-scavenging activity, FRAP(ferric-reducing antioxidant power) and reducing power. The major phenolic compounds, including cyanidin-3-galactoside, cyanidin-3-arabinoside, neochlorogenic acid, procyanidin B1, were analysed by HPLC with a photodiode array detector. Results showed that total phenol, flavonoid and proanthocyanidin contents of black chokeberry extract were higher than those of blueberry extract. In addition, black chokeberry extract exhibited higher free radical-scavenging activity and reducing power than did blueberry extract. Cyanidin-3-galactoside was identified as a major phenolic compound, with considerable content in black chokeberry, that correlated with its higher antioxidant and radical-scavenging effects. These results suggest that black chokeberry extracts could be considered as a good source of natural antioxidants and functional food ingredients. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. A Cloud-Based Scavenger Hunt: Orienting Undergraduates to ACS National Meetings

    Science.gov (United States)

    Kubasik, Matthew A.; Van Dyke, Aaron R.; Harper-Leatherman, Amanda S.; Miecznikowski, John R.; Steffen, L. Kraig; Smith-Carpenter, Jillian

    2016-01-01

    American Chemical Society (ACS) National Meetings are valuable for the development of undergraduate researchers but can be overwhelming for first-time attendees. To orient and engage students with the range of offerings at an ACS meeting, we developed a cloud-based scavenger hunt. Using their mobile devices, teams of undergraduates…

  5. Preliminary assay on the radical scavenging activity of olive wood extracts

    NARCIS (Netherlands)

    Altarejos, J.; Salido, S.; Pérez-Bonilla, M.; Linares-Palomino, P.J.; Beek, van T.A.; Nogueras, M.; Sánchez, A.

    2005-01-01

    The dichloromethane and ethanol extracts of Olea europaea wood (picual olive cultivar) were screened for antioxidant activity, determined by the DPPH free radical scavenging assay. The ethanol extract displayed potent antioxidant activity. (c) 2005 Elsevier B.V. All rights reserved.

  6. Chemical Constituents with Free-Radical-Scavenging Activities from the Stem of Microcos paniculata

    Directory of Open Access Journals (Sweden)

    Yu Chen

    2010-08-01

    Full Text Available The free-radical-scavenging activities of various solvent extracts of Microcos paniculata were evaluated through in vitro model systems, such as 1,1-diphenyl-2-picrylhydrazyl (DPPH, 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonate (ABTS and Co (II EDTA-induced luminol chemiluminescence by flow injection. In all three of these systems the ethyl acetate (EtOAc extract showed the highest free-radical-scavenging activity compared with the other three (n-BuOH, water and petroleum ether extracts. Free-radical-scavenging assay-guided chromatographic separation of the EtOAc extract, using a normal-phase and reverse-phase silica gel column chromatography yielded five compounds: a new triterpene named methyl 3b-O-p-hydroxy-E-cinnamoyloxy-2a,23-dihydroxyolean-12-en-28-oate (1, whose spectral data are presented for the first time, together with four known compounds, epicatechin (2, 3-trans-feruloyl maslinic acid (3, maslinic acid (4 and sucrose (5. All of the compounds were isolated from Microcos paniculata for the first time. The compounds were identified by spectroscopic methods. Among them, compound 2 displayed significant free-radical-scavenging activity which is similar to that of standard antioxidant ascorbic acid (VC and therefore may be a promising natural antioxidant.

  7. Proteolytic shedding of the macrophage scavenger receptor CD163 in multiple sclerosis

    DEFF Research Database (Denmark)

    Fabriek, Babs O; Møller, Holger J; Vloet, Rianka P M

    2007-01-01

    The scavenger receptor CD163 is selectively expressed on tissue macrophages and human monocytes. CD163 has been implicated to play a role in the clearance of hemoglobin and in the regulation of cytokine production by macrophages. Membrane CD163 can be cleaved by matrix metalloproteinases (MMP...

  8. Parametric Study of the Scavenging Process in Marine Two-Stroke Diesel Engines

    DEFF Research Database (Denmark)

    Andersen, Fredrik Herland; Mayer, Stefan

    2015-01-01

    pressure are varied. TheCFD model comprise the full geometry from scavenge receiverto exhaust receiver. Asymmetric inlet and outlet conditions isincluded as well as the dynamics of a moving piston and valve.Time resolved boundary conditions corresponding tomeasurements from an operating, full scale...

  9. Transgenic mouse models to study the role of the macrophage scavenger receptor class A in atherosclerosis

    NARCIS (Netherlands)

    de Winther, M. P.; Gijbels, M. J.; van Dijk, K. W.; Havekes, L. M.; Hofker, M. H.

    2000-01-01

    Several in vivo studies have been performed on the role of the macrophage scavenger receptor class A (SR-A) in atherosclerosis using SR-A knockout mice. The results indicate both an antiatherogenic and a proatherogenic role of SR-A, depending on the nature of the animal model serving as the

  10. The macrophage scavenger receptor CD163 functions as an innate immune sensor for bacteria

    NARCIS (Netherlands)

    Fabriek, Babs O.; van Bruggen, Robin; Deng, Dong Mei; Ligtenberg, Antoon J. M.; Nazmi, Kamran; Schornagel, Karin; Vloet, Rianka P. M.; Dijkstra, Christine D.; van den Berg, Timo K.

    2009-01-01

    The plasma membrane glycoprotein receptor CD163 is a member of the scavenger receptor cystein-rich (SRCR) superfamily class B that is highly expressed on resident tissue macrophages in vivo. Previously, the molecule has been shown to act as a receptor for hemoglobin-haptoglobin complexes and to

  11. Novel mutations in scavenger receptor BI associated with high HDL cholesterol in humans

    NARCIS (Netherlands)

    Brunham, Liam R.; Tietjen, Ian; Bochem, Andrea E.; Singaraja, Roshni R.; Franchini, Patrick L.; Radomski, Chris; Mattice, Maryanne; Legendre, Annick; Hovingh, G. Kees; Kastelein, John J. P.; Hayden, Michael R.

    2011-01-01

    The scavenger receptor class B, member 1 (SR-BI), is a key cellular receptor for high-density lipoprotein (HDL) in mice, but its relevance to human physiology has not been well established. Recently a family was reported with a mutation in the gene encoding SR-BI and high HDL cholesterol (HDL-C).

  12. CXCR7 functions as a scavenger for CXCL12 and CXCL11.

    Directory of Open Access Journals (Sweden)

    Ulrike Naumann

    2010-02-01

    Full Text Available CXCR7 (RDC1, the recently discovered second receptor for CXCL12, is phylogenetically closely related to chemokine receptors, but fails to couple to G-proteins and to induce typical chemokine receptor mediated cellular responses. The function of CXCR7 is controversial. Some studies suggest a signaling activity in mammalian cells and zebrafish embryos, while others indicate a decoy activity in fish. Here we investigated the two propositions in human tissues.We provide evidence and mechanistic insight that CXCR7 acts as specific scavenger for CXCL12 and CXCL11 mediating effective ligand internalization and targeting of the chemokine cargo for degradation. Consistently, CXCR7 continuously cycles between the plasma membrane and intracellular compartments in the absence and presence of ligand, both in mammalian cells and in zebrafish. In accordance with the proposed activity as a scavenger receptor CXCR7-dependent chemokine degradation does not become saturated with increasing ligand concentrations. Active CXCL12 sequestration by CXCR7 is demonstrated in adult mouse heart valves and human umbilical vein endothelium.The finding that CXCR7 specifically scavenges CXCL12 suggests a critical function of the receptor in modulating the activity of the ubiquitously expressed CXCR4 in development and tumor formation. Scavenger activity of CXCR7 might also be important for the fine tuning of the mobility of hematopoietic cells in the bone marrow and lymphoid organs.

  13. Hunting for Knowledge: Using a Scavenger Hunt to Orient Graduate Veterinary Students

    Science.gov (United States)

    Pike, Caitlin; Alpi, Kristine M.

    2015-01-01

    Active participation in orientation is hoped to increase understanding and use of library resources and services beyond the effect of tours or welcome lectures. Timed scavenger hunts have been used to orient undergraduate and medical students to academic libraries. This report describes the planning, execution, and evaluation of an untimed…

  14. Ultimate Scaling of High-κ Gate Dielectrics: Higher-κ or Interfacial Layer Scavenging?

    Directory of Open Access Journals (Sweden)

    Takashi Ando

    2012-03-01

    Full Text Available Current status and challenges of aggressive equivalent-oxide-thickness (EOT scaling of high-κ gate dielectrics via higher-κ ( > 20 materials and interfacial layer (IL scavenging techniques are reviewed. La-based higher-κ materials show aggressive EOT scaling (0.5–0.8 nm, but with effective workfunction (EWF values suitable only for n-type field-effect-transistor (FET. Further exploration for p-type FET-compatible higher-κ materials is needed. Meanwhile, IL scavenging is a promising approach to extend Hf-based high-κ dielectrics to future nodes. Remote IL scavenging techniques enable EOT scaling below 0.5 nm. Mobility-EOT trends in the literature suggest that short-channel performance improvement is attainable with aggressive EOT scaling via IL scavenging or La-silicate formation. However, extreme IL scaling (e.g., zero-IL is accompanied by loss of EWF control and with severe penalty in reliability. Therefore, highly precise IL thickness control in an ultra-thin IL regime ( < 0.5 nm will be the key technology to satisfy both performance and reliability requirements for future CMOS devices.

  15. Radical-Scavenging Compounds from Olive Tree (Olea europaea L.) wood

    NARCIS (Netherlands)

    Pérez-Bonilla, M.; Salido, S.; Beek, van T.A.; Altarejos, J.

    2014-01-01

    The purpose of this study was to complete knowledge on the chemical composition and radical-scavenging activity of olive tree wood. Two new monoterpene glycosides, (-)-oleuropeic acid 6'-O-a-d-glucopyranosyl ester (6a) and (-)-perillic acid 1'-O-ß-d-primeverosyl ester (8), together with the known

  16. Isolation and identification of radical scavengers in olive tree (Olea europaea) wood

    NARCIS (Netherlands)

    Pérez-Bonilla, M.; Salido, S.; Beek, van T.A.; Linares-Palomino, P.J.; Altarejos, J.; Nogueras, M.; Sánchez, A.

    2006-01-01

    Several extracts of Olea europaea wood (Picual olive cultivar) were obtained with solvents of different polarity and their antioxidant activities determined. The active compounds were detected in fractions of an ethyl acetate extract using HPLC with on-line radical scavenging detection. After

  17. A note on scavenging behaviour of adult Hermann’s tortoise (Testudo hermanni

    Directory of Open Access Journals (Sweden)

    Nikolić, M.

    2016-09-01

    Full Text Available Report of the first observation of scavenging behaviour in the population of Testudo hermanni boettgeri that has been monitored for six years in the village Kunovica near the city of Niš in Serbia. On 31 May 2015 at 10:18 a.m., the adult tortoise was observed while eating a dead European green lizard (Lacerta viridis.

  18. An anaerobic bacterium, Bacteroides thetaiotaomicron, uses a consortium of enzymes to scavenge hydrogen peroxide

    Science.gov (United States)

    Mishra, Surabhi; Imlay, James A.

    2013-01-01

    Summary Obligate anaerobes are periodically exposed to oxygen, and it has been conjectured that on such occasions their low-potential biochemistry will predispose them to rapid ROS formation. We sought to identify scavenging enzymes that might protect the anaerobe Bacteroides thetaiotaomicron from the H2O2 that would be formed. Genetic analysis of eight candidate enzymes revealed that four of these scavenge H2O2 in vivo: rubrerythrins 1 and 2, AhpCF, and catalase E. The rubrerythrins served as key peroxidases under anoxic conditions. However, they quickly lost activity upon aeration, and AhpCF and catalase were induced to compensate. The AhpCF is an NADH peroxidase that effectively degraded low micromolar levels of H2O2, while the catalytic cycle of catalase enabled it to quickly degrade higher concentrations that might arise from exogenous sources. Using a non-scavenging mutant we verified that endogenous H2O2 formation was much higher in aerated B. thetaiotaomicron than in Escherichia coli. Indeed, the OxyR stress response to H2O2 was induced when B. thetaiotaomicron was aerated, and in that circumstance this response was necessary to forestall cell death. Thus aeration is a serious threat for this obligate anaerobe, and to cope it employs a set of defenses that includes a repertoire of complementary scavenging enzymes. PMID:24164536

  19. Seroepidemiologic Survey of Potential Pathogens in Obligate and Facultative Scavenging Avian Species in California

    Science.gov (United States)

    Straub, Mary H.; Kelly, Terra R.; Rideout, Bruce A.; Eng, Curtis; Wynne, Janna; Braun, Josephine; Johnson, Christine K.

    2015-01-01

    Throughout the world, populations of scavenger birds are declining rapidly with some populations already on the brink of extinction. Much of the current research into the factors contributing to these declines has focused on exposure to drug residues, lead, and other toxins. Despite increased monitoring of these declining populations, little is known about infectious diseases affecting scavenger bird species. To assess potential infectious disease risks to both obligate and facultative scavenger bird species, we performed a serosurvey for eleven potential pathogens in three species of scavenging birds in California: the California condor (Gymnogyps californianus), turkey vulture (Cathartes aura) and golden eagle (Aquila chrysaetos). California condors were seropositive for avian adenovirus, infectious bronchitis virus, Mycoplasma gallisepticum, avian paramyxovirus-2, West Nile virus (WNV) and Toxoplasma gondii. Golden eagles were seropositive for avian adenovirus, Chlamydophila psittaci and Toxoplasma gondii, and turkey vultures were seropositive for avian adenovirus, Chlamydophila psittaci, avian paramyxovirus-1, Toxoplasma gondii and WNV. Risk factor analyses indicated that rearing site and original release location were significantly associated with a positive serologic titer to WNV among free-flying condors. This study provides preliminary baseline data on infectious disease exposure in these populations for aiding in early disease detection and provides potentially critical information for conservation of the endangered California condor as it continues to expand its range and encounter new infectious disease threats. PMID:26606755

  20. [Correlation Between Functional Groups and Radical Scavenging Activities of Acidic Polysaccharides from Dendrobium].

    Science.gov (United States)

    Liao, Ying; Yuan, Wen-yu; Zheng, Wen-ke; Luo, Ao-xue; Fan, Yi-jun

    2015-11-01

    To compare the radical scavenging activity of five different acidic polysaccharides, and to find the correlation with the functional groups. Alkali extraction method and Stepwise ethanol precipitation method were used to extract and concentrate the five Dendrobium polysaccharides, and to determine the contents of sulfuric acid and uronic acid of each kind of acidic polysaccharides, and the scavenging activity to ABTS+ radical and hydroxyl radical. Functional group structures were examined by FTIR Spectrometer. Five kinds of Dendrobium polysaccharides had different ability of scavenging ABTS+ free radical and hydroxyl free radical. Moreover, the study had shown that five kinds of antioxidant activity of acidic polysaccharides had obvious correlation withuronic acid and sulfuric acid. The antioxidant activity of each sample was positively correlated with the content of uronic acid, and negatively correlated with the content of sulfuric acid. Sulfuric acid can inhibit the antioxidant activity of acidic polysaccharide but uronic acid can enhance the free radical scavenging activity. By analyzing the structure characteristics of five acidic polysaccharides, all samples have similar structures, however, Dendrobium denneanum, Dendrobium devonianum and Dendrobium officinale which had β configuration have higher antioxidant activity than Dendrobium nobile and Dendrobium fimbriatum which had a configuration.

  1. Simulation for estimation of hydrogen sulfide scavenger injection dose rate for treatment of crude oil

    Directory of Open Access Journals (Sweden)

    T.M. Elshiekh

    2015-12-01

    Full Text Available The presence of hydrogen sulfide in the hydrocarbon fluids is a well known problem in many oil and gas fields. Hydrogen sulfide is an undesirable contaminant which presents many environmental and safety hazards. It is corrosive, malodorous, and toxic. Accordingly, a need has been long left in the industry to develop a process which can successfully remove hydrogen sulfide from the hydrocarbons or at least reduce its level during the production, storage or processing to a level that satisfies safety and product specification requirements. The common method used to remove or reduce the concentration of hydrogen sulfide in the hydrocarbon production fluids is to inject the hydrogen sulfide scavenger into the hydrocarbon stream. One of the chemicals produced by the Egyptian Petroleum Research Institute (EPRI is EPRI H2S scavenger. It is used in some of the Egyptian petroleum producing companies. The injection dose rate of H2S scavenger is usually determined by experimental lab tests and field trials. In this work, this injection dose rate is mathematically estimated by modeling and simulation of an oil producing field belonging to Petrobel Company in Egypt which uses EPRI H2S scavenger. Comparison between the calculated and practical values of injection dose rate emphasizes the real ability of the proposed equation.

  2. Rare variant in scavenger receptor BI raises HDL cholesterol and increases risk of coronary heart disease

    Science.gov (United States)

    Scavenger receptor BI (SR-BI) is the major receptor for high-density lipoprotein (HDL) cholesterol (HDL-C). In humans, high amounts of HDL-C in plasma are associated with a lower risk of coronary heart disease (CHD). Mice that have depleted Scarb1 (SR-BI knockout mice) have markedly elevated HDL-C l...

  3. Turbulent swirling flow in a model of a uniflow-scavenged two-stroke engine

    DEFF Research Database (Denmark)

    Ingvorsen, Kristian Mark; Meyer, Knud Erik; Walther, Jens Honore

    2013-01-01

    The turbulent and swirling flow of a uniflow-scavenged two-stroke engine cylinder is investigated using a scale model with a static geometry and a transparent cylinder. The swirl is generated by 30 equally spaced ports with angles of 0°, 10°, 20°, and 30°. A detailed characterization of the flow...

  4. Rare variant in scavenger receptor BI raises HDL cholesterol and increases risk of coronary heart disease

    DEFF Research Database (Denmark)

    Zanoni, Paolo; Khetarpal, Sumeet A; Larach, Daniel B

    2016-01-01

    Scavenger receptor BI (SR-BI) is the major receptor for high-density lipoprotein (HDL) cholesterol (HDL-C). In humans, high amounts of HDL-C in plasma are associated with a lower risk of coronary heart disease (CHD). Mice that have depleted Scarb1 (SR-BI knockout mice) have markedly elevated HDL-...

  5. Highly functionalized piperidines: Free radical scavenging, anticancer activity, DNA interaction and correlation with biological activity

    Directory of Open Access Journals (Sweden)

    Suvankar Das

    2018-01-01

    Full Text Available Twenty-five piperidines were studied as potential radical scavengers and antitumor agents. Quantitative interaction of compounds with ctDNA using spectroscopic techniques was also evaluated. Our results demonstrate that the evaluated piperidines possesses different abilities to scavenge the radical 2,2-diphenyl-1-picrylhydrazyl (DPPH and the anion radical superoxide (·O2−. The piperidine 19 was the most potent radical DPPH scavenger, while the most effective to ·O2− scavenger was piperidine 10. In general, U251, MCF7, NCI/ADR-RES, NCI-H460 and HT29 cells were least sensitive to the tested compounds and all compounds were considerably more toxic to the studied cancer cell lines than to the normal cell line HaCaT. The binding mode of the compounds and ctDNA was preferably via intercalation. In addition, these results were confirmed based on theoretical studies. Finally, a linear and exponential correlation between interaction constant (Kb and GI50 for several human cancer cell was observed.

  6. Variations of Antioxidant Properties and NO Scavenging Abilities during Fermentation of Tea

    Science.gov (United States)

    Xu, Yang; Zhao, Hang; Zhang, Min; Li, Chun-Jie; Lin, Xue-Zhen; Sheng, Jun; Shi, Wei

    2011-01-01

    Tea is known as one of the most popular beverages in the world, which is believed to be beneficial for health. The main components in tea will change a lot depending on the different processes of fermentation, and thus the effects of different teas on human health may differ. The aim of this study is to explore the varied abilities of reactive oxygen species (ROS) and nitric oxide (NO) scavenging during the fermentation of tea. In this study, we conducted the in vitro experiments which involved some reaction systems indicating the abilities of scavenging ROS and NO. We also investigated the effects of tea and their components (catechins, theabrownins, caffeine) on the intracellular levels of ROS and NO, using Raw 264.7 cells as the model. We found that regardless of whether it was out of cell system or in Raw 264.7 cells, the abilities of scavenging ROS would decrease during the fermentation of tea. Further, the post-fermented pu-erh tea showed the best effect on inhibiting the lipopolysaccharide (LPS)-induced production of NO. These findings indicated that the fermentation process caused a change of the components which might be due to the changes of their antioxidant properties and NO scavenging abilities. PMID:21845097

  7. Efficacy of HOCl scavenging by sulfur-containing compounds: antioxidant activity of glutathione disulfide?

    NARCIS (Netherlands)

    den Hartog, G.J.M.; Haenen, G.R.M.M.; Vegt, E.; van der Vijgh, W.J.F.; Bast, A.

    2002-01-01

    Efficacy of HOCl scavenging by sulfur-containing compounds: antioxidant activity of glutathione disulfide? den Hartog GJ, Haenen GR, Vegt E, van der Vijgh WJ, Bast A. Department of Pharmacology and Toxicology, Maastricht University, The Netherlands. Hypochlorous acid (HOCl) is a bactericidal

  8. Structure dependent antioxidant capacity of phlorotannins from Icelandic Fucus vesiculosus by UHPLC-DAD-ECD-QTOFMS

    DEFF Research Database (Denmark)

    Hermund, Ditte Baun; Plaza, Merichel; Turner, Charlotta

    2018-01-01

    Brown algae are rich in polyphenolic compounds, phlorotannins, which have been found to possess high in vitro antioxidant capacity, especially DPPH radical scavenging activity, due to the high number of hydroxyl groups. Whereas, the overall antioxidant capacity of brown algae extracts has been...... was determined by an on-line method using liquid chromatography and an electrochemical detector followed by quadrupole Time of Flight mass spectrometry (UHPLC-DAD-ECD-QTOFMS). Tentative structural elucidation of 13 phlorotannin isomers from EAF was obtained by LC-DAD-QTOFMS, ranging from 374 to 870 Da. On...

  9. Scavenger receptor classes A and B. Their roles in atherogenesis and the metabolism of modified LDL and HDL

    NARCIS (Netherlands)

    van Berkel, T. J.; van Eck, M.; Herijgers, N.; Fluiter, K.; Nion, S.

    2000-01-01

    Scavenger-receptor class A has been held responsible for the clearance of modified LDL from the blood circulation. However, in mice deficient in scavenger-receptor class A, the decay in vivo of acetylated LDL (t1/2 <2 min), as well as tissue distribution and liver uptake (at 5 min 77.4 +/- 4.6% of

  10. Constraints from Airborne (210)Pb Observations on Aerosol Scavenging and Lifetime in a Global Chemical Transport Model

    Science.gov (United States)

    Zhang, Bo; Liu, Hongyu; Crawford, James H.; Fairlie, Duncan T.; Chen, Gao; Dibb, Jack E.; Shah, Viral; Sulprizio, Melissa P.; Yantosca, Robert M.

    2016-01-01

    Lead-210 distribution and lifetime in the atmosphere are not sensitive to ice in-cloud scavenging in convective updraft. Ice in-cloud scavenging in stratiform clouds reduce tropospheric (210)Pb lifetime by approximately 1 day and results in better agreements with observed surface observations and aircraft measured profiles. However, the process results in significant underestimate of (210)Pb in UT/LS.

  11. Free radical scavenging activity and lipid peroxidation inhibition of Hypericum helianthemoides (spach Boiss

    Directory of Open Access Journals (Sweden)

    Soheila Moein

    2015-06-01

    Full Text Available Antioxidants are compounds that obstruct the oxidation of macromolecules in the body. In general, there are two categories of antioxidants, natural and synthetic. Recently, interest has been increased considerably for obtaining new natural antioxidants. In this study, the scavenging of free radicals such as DPPH, NO and OH by Hypericum helianthemoides extract was evaluated. Also, the antioxidant properties of this extract were evaluated by FRAP, FTC methods and determination phenolic compounds. The plant was collected from north of Fars Province and plant extraction was obtained using ethanol. In DPPH radical scavenging, different concentrations of the Hypericum extract were added to DPPH radical. In hydroxyl radical scavenging, Fenton reaction mixture, TCA and TBA were mixed with Hypericum extract. In nitric radical scavenging, nitropruside was mixed with Hypericum extract and then sulphanilic acid, naphthylene diamine were added. In determination of phenolic compounds, Folin-ciocalteu and sodium carbonate were added to Hypericum extract. In DPPH radical scavenging, the IC50 of Hypericum extract (309.35±6.5μg/ml was higher than the antioxidant standards, BHT (IC50=81.9±2.6 μg/ml and quercetin (IC50=60.04±6.48 μg/ml. The highest scavenging of hydroxyl radicals was observed in Hypericum extract (70.3±0.8%, 125 μg/ml. In gallic acid it was (73.8±3.3%. In 200 μg/ml of Hypericum extract scavenged NO radical (85.2±2.7%. In FRAP method, the IC50 of this extract was 109.7±10.5 μg/ml. In FTC method, the inhibition of lipid peroxidation by Hypericum extract, BHT and ascorbic acid were 59.2±2.2, 66.9±0.15, 64.06±0.02 respectively. Total phenol of the plant extract was 3±0.4 mg/g.

  12. Phytochemical Analysis and Free Radical Scavenging Activity of Medicinal Plants Gnidia glauca and Dioscorea bulbifera

    Science.gov (United States)

    Ghosh, Sougata; Derle, Abhishek; Ahire, Mehul; More, Piyush; Jagtap, Soham; Phadatare, Suvarna D.; Patil, Ajay B.; Jabgunde, Amit M.; Sharma, Geeta K.; Shinde, Vaishali S.; Pardesi, Karishma; Dhavale, Dilip D.; Chopade, Balu A.

    2013-01-01

    Gnidia glauca and Dioscorea bulbifera are traditional medicinal plants that can be considered as sources of natural antioxidants. Herein we report the phytochemical analysis and free radical scavenging activity of their sequential extracts. Phenolic and flavonoid content were determined. Scavenging activity was checked against pulse radiolysis generated ABTS•+ and OH radical, in addition to DPPH, superoxide and hydroxyl radicals by biochemical methods followed by principal component analysis. G. glauca leaf extracts were rich in phenolic and flavonoid content. Ethyl acetate extract of D. bulbifera bulbs and methanol extract of G. glauca stem exhibited excellent scavenging of pulse radiolysis generated ABTS•+ radical with a second order rate constant of 2.33×106 and 1.72×106, respectively. Similarly, methanol extract of G. glauca flower and ethyl acetate extract of D. bulbifera bulb with second order rate constants of 4.48×106 and 4.46×106 were found to be potent scavengers of pulse radiolysis generated OH radical. G. glauca leaf and stem showed excellent reducing activity and free radical scavenging activity. HPTLC fingerprinting, carried out in mobile phase, chloroform: toluene: ethanol (4: 4: 1, v/v) showed presence of florescent compound at 366 nm as well as UV active compound at 254 nm. GC-TOF-MS analysis revealed the predominance of diphenyl sulfone as major compound in G. glauca. Significant levels of n-hexadecanoic acid and octadecanoic acid were also present. Diosgenin (C27H42O3) and diosgenin (3á,25R) acetate were present as major phytoconstituents in the extracts of D. bulbifera. G. glauca and D. bulbifera contain significant amounts of phytochemicals with antioxidative properties that can be exploited as a potential source for herbal remedy for oxidative stress induced diseases. These results rationalize further investigation in the potential discovery of new natural bioactive principles from these two important medicinal plants. PMID:24367520

  13. Evaluation of free radical scavenging activity of tea infusion of commercial tea products available in uae

    International Nuclear Information System (INIS)

    Nessa, F.; Khan, S.A.

    2014-01-01

    In the present study, twenty four commercial tea samples were assayed to determine their free radical scavenging activity and polyphenolic contents based on the brewing/infusing period. Tea samples were infused/brewed in 200 mL boiled water at 120 degree C for 1, 2 and 5 min, respectively. The radical scavenging activities of tea infusion/brewing were measured using 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) assay method. The results were ranged from 67.81-90.51% for black tea bags, 90.37-94.51% for green tea bags, 24.66-92.25% for black tea powder, 16.08-93.06% for green tea powder and 32.90- 45.54% for Camomile herbal infusion. The results showed that 1 or 2 min black tea bags infusion exhibited highest radical scavenging activity than 5 min infusion. Antioxidant activities of tea powders were variable with the amount of tea powder. It was observed that antioxidant activity increased with increasing boiling time for smaller amount of sample. In contrary, shorter boiling time was better for larger amount of sample. The polyphenol contents of tea infusion were determined and the results were expressed as milligram quercetin equivalent/200 mL of tea infusion. The polyphenol content was increased with increased brewing period. In contrary, brewing for longer time rendered extract less antiradical activity. This study suggests that infusing tea bag for 1 or 2 min is sufficient for getting infusion with maximum radical scavenging activity and in case of tea powder, shorter boiling time is better for larger amount of powder or small amount of powder should be boiled for minimum 5 min for rendering extract with maximum radical scavenging activity. (author)

  14. High risk of lead contamination for scavengers in an area with high moose hunting success.

    Science.gov (United States)

    Legagneux, Pierre; Suffice, Pauline; Messier, Jean-Sébastien; Lelievre, Frédérick; Tremblay, Junior A; Maisonneuve, Charles; Saint-Louis, Richard; Bêty, Joël

    2014-01-01

    Top predators and scavengers are vulnerable to pollutants, particularly those accumulated along the food chain. Lead accumulation can induce severe disorders and alter survival both in mammals (including humans) and in birds. A potential source of lead poisoning in wild animals, and especially in scavengers, results from the consumption of ammunition residues in the tissues of big game killed by hunters. For two consecutive years we quantified the level lead exposure in individuals of a sentinel scavenger species, the common raven (Corvus corax), captured during the moose (Alces alces) hunting season in eastern Quebec, Canada. The source of the lead contamination was also determined using stable isotope analyses. Finally, we identified the different scavenger species that could potentially be exposed to lead by installing automatic cameras targeting moose gut piles. Blood lead concentration in ravens increased over time, indicating lead accumulation over the moose-hunting season. Using a contamination threshold of 100 µg x L(-1), more than 50% of individuals were lead-contaminated during the moose hunting period. Lead concentration was twice as high in one year compared to the other, matching the number of rifle-shot moose in the area. Non-contaminated birds exhibited no ammunition isotope signatures. The isotope signature of the lead detected in contaminated ravens tended towards the signature from lead ammunition. We also found that black bears (Ursus americanus), golden eagles and bald eagles (Aquila chrysaetos and Haliaeetus leucocephalus, two species of conservation concern) scavenged heavily on moose viscera left by hunters. Our unequivocal results agree with other studies and further motivate the use of non-toxic ammunition for big game hunting.

  15. High risk of lead contamination for scavengers in an area with high moose hunting success.

    Directory of Open Access Journals (Sweden)

    Pierre Legagneux

    Full Text Available Top predators and scavengers are vulnerable to pollutants, particularly those accumulated along the food chain. Lead accumulation can induce severe disorders and alter survival both in mammals (including humans and in birds. A potential source of lead poisoning in wild animals, and especially in scavengers, results from the consumption of ammunition residues in the tissues of big game killed by hunters. For two consecutive years we quantified the level lead exposure in individuals of a sentinel scavenger species, the common raven (Corvus corax, captured during the moose (Alces alces hunting season in eastern Quebec, Canada. The source of the lead contamination was also determined using stable isotope analyses. Finally, we identified the different scavenger species that could potentially be exposed to lead by installing automatic cameras targeting moose gut piles. Blood lead concentration in ravens increased over time, indicating lead accumulation over the moose-hunting season. Using a contamination threshold of 100 µg x L(-1, more than 50% of individuals were lead-contaminated during the moose hunting period. Lead concentration was twice as high in one year compared to the other, matching the number of rifle-shot moose in the area. Non-contaminated birds exhibited no ammunition isotope signatures. The isotope signature of the lead detected in contaminated ravens tended towards the signature from lead ammunition. We also found that black bears (Ursus americanus, golden eagles and bald eagles (Aquila chrysaetos and Haliaeetus leucocephalus, two species of conservation concern scavenged heavily on moose viscera left by hunters. Our unequivocal results agree with other studies and further motivate the use of non-toxic ammunition for big game hunting.

  16. Chlorine dioxide as phenol and H2S scavenger - formation of halogenated phenols and subsequent environmental risk

    Energy Technology Data Exchange (ETDEWEB)

    Melbye, Alf G.; Faksness, Liv-Guri; Knudsen, Boerre Leif

    2006-03-15

    Formation of halogenated phenols as side products from treatment of produced water with aqueous chlorine dioxide has been investigated. The literature describes formation of halogenated hydrocarbons in effluent treatment using chlorine, hypochlorite and chlorine dioxide. A new chlorine dioxide product, originally intended as a H2S scavenger in the oil and gas industry, has been tested both as a phenol scavenger and H2S-scavenger for produced water applications. The concern about the possible formation of halogenated by-products initiated laboratory testing of chlorine dioxide as phenol and H2S scavenger for produced water applications. The tests also included synthetic matrixes containing phenols, and the tests show that halogenated phenols, mainly brominated species, are found in produced water after treatment with chlorine dioxide. Due to potential environmental risk from halogenated organic contaminants, the use of chlorine dioxide as phenol and H2S scavenger is not recommended. (Author)

  17. Effect of concentration and molecular weight of chitosan and its derivative on the free radical scavenging ability.

    Science.gov (United States)

    Li, Huili; Xu, Qing; Chen, Yun; Wan, Ajun

    2014-03-01

    Chitosan is a biodegradable and biocompatible natural scaffold material, which has numerous applications in biomedical sciences. In this study, the in vitro antioxidant activity of chitosan scaffold material was investigated by the chemiluminescence signal generated from the hydroxyl radical (•OH) scavenging assay. The scavenging mechanism was also discussed. The results indicated that the free radical scavenging ability of chitosan scaffold material significantly depends on the chitosan concentration and shows interesting kinetic change. Within the experimental concentration range, the optimal concentration of chitosan was 0.2 mg/mL. The molecular weight of chitosan also attributed to the free radical scavenging ability. Comparison between chitosan and its derivative found that carboxymethyl chitosan possessed higher scavenging ability. Copyright © 2013 Society of Plastics Engineers.

  18. Capacity Maximizing Constellations

    Science.gov (United States)

    Barsoum, Maged; Jones, Christopher

    2010-01-01

    Some non-traditional signal constellations have been proposed for transmission of data over the Additive White Gaussian Noise (AWGN) channel using such channel-capacity-approaching codes as low-density parity-check (LDPC) or turbo codes. Computational simulations have shown performance gains of more than 1 dB over traditional constellations. These gains could be translated to bandwidth- efficient communications, variously, over longer distances, using less power, or using smaller antennas. The proposed constellations have been used in a bit-interleaved coded modulation system employing state-ofthe-art LDPC codes. In computational simulations, these constellations were shown to afford performance gains over traditional constellations as predicted by the gap between the parallel decoding capacity of the constellations and the Gaussian capacity

  19. Dual capacity reciprocating compressor

    Science.gov (United States)

    Wolfe, Robert W.

    1984-01-01

    A multi-cylinder compressor 10 particularly useful in connection with northern climate heat pumps and in which different capacities are available in accordance with reversing motor 16 rotation is provided with an eccentric cam 38 on a crank pin 34 under a fraction of the connecting rods, and arranged for rotation upon the crank pin between opposite positions 180.degree. apart so that with cam rotation on the crank pin such that the crank throw is at its normal maximum value all pistons pump at full capacity, and with rotation of the crank shaft in the opposite direction the cam moves to a circumferential position on the crank pin such that the overall crank throw is zero. Pistons 24 whose connecting rods 30 ride on a crank pin 36 without a cam pump their normal rate with either crank rotational direction. Thus a small clearance volume is provided for any piston that moves when in either capacity mode of operation.

  20. Visual attention capacity

    DEFF Research Database (Denmark)

    Habekost, Thomas; Starrfelt, Randi

    2009-01-01

    Psychophysical studies have identified two distinct limitations of visual attention capacity: processing speed and apprehension span. Using a simple test, these cognitive factors can be analyzed by Bundesen's Theory of Visual Attention (TVA). The method has strong specificity and sensitivity......, and measurements are highly reliable. As the method is theoretically founded, it also has high validity. TVA-based assessment has recently been used to investigate a broad range of neuropsychological and neurological conditions. We present the method, including the experimental paradigm and practical guidelines...... to patient testing, and review existing TVA-based patient studies organized by lesion anatomy. Lesions in three anatomical regions affect visual capacity: The parietal lobes, frontal cortex and basal ganglia, and extrastriate cortex. Visual capacity thus depends on large, bilaterally distributed anatomical...

  1. Aerosol size-dependent below-cloud scavenging by rain and snow in the ECHAM5-HAM

    Directory of Open Access Journals (Sweden)

    R. Posselt

    2009-07-01

    Full Text Available Wet deposition processes are highly efficient in the removal of aerosols from the atmosphere, and thus strongly influence global aerosol concentrations, and clouds, and their respective radiative forcings. In this study, physically detailed size-dependent below-cloud scavenging parameterizations for rain and snow are implemented in the ECHAM5-HAM global aerosol-climate model. Previously, below-cloud scavenging by rain in the ECHAM5-HAM was simply a function of the aerosol mode, and then scaled by the rainfall rate. The below-cloud scavenging by snow was a function of the snowfall rate alone. The global mean aerosol optical depth, and sea salt burden are sensitive to the below-cloud scavenging coefficients, with reductions near to 15% when the more vigorous size-dependent below-cloud scavenging by rain and snow is implemented. The inclusion of a prognostic rain scheme significantly reduces the fractional importance of below-cloud scavenging since there is higher evaporation in the lower troposphere, increasing the global mean sea salt burden by almost 15%. Thermophoretic effects are shown to produce increases in the global and annual mean number removal of Aitken size particles of near to 10%, but very small increases (near 1% in the global mean below-cloud mass scavenging of carbonaceous and sulfate aerosols. Changes in the assumptions about the below-cloud scavenging by rain of particles with radius smaller than 10 nm do not cause any significant changes to the global and annual mean aerosol mass or number burdens, despite a change in the below-cloud number removal rate for nucleation mode particles by near to five-fold. Annual and zonal mean nucleation mode number concentrations are enhanced by up to 30% in the lower troposphere with the more vigourous size-dependent below-cloud scavenging. Closer agreement with different observations is found when the more physically detailed below-cloud scavenging parameterization is employed in the ECHAM5

  2. Value for railway capacity

    DEFF Research Database (Denmark)

    Sameni, Melody Khadem; Preston, John M.

    2012-01-01

    to analyze the efficiency of operators in transforming inputs of allocated capacity of infrastructure and franchise payments into valuable passenger service outputs while avoiding delays. By addressing operational and economic aspects of capacity utilization simultaneously, the paper deviates from existing...... DEA work on the economic efficiency of railways by considering a new combination of input-output that also incorporates quality of service. The constant and variable returns to scale models are applied to the case study of franchised passenger operators in Great Britain. The follow-up Tobit regression...

  3. Mass Proportion, Bioactive Compounds and Antioxidant Capacity of Carrot Peel as Affected by Various Solvents

    Directory of Open Access Journals (Sweden)

    Van Tang Nguyen

    2016-11-01

    Full Text Available The aim of this study was to determine the mass proportion of carrot root and the effects of four various solvents (methanol, water, ethanol and hexane on the contents of total phenolics and saponins as well as antioxidant capacity of carrot peel to identify an optimal solvent for effective extraction of bioactive compounds from carrot peel for further investigation. The results showed that carrot root consisted of body, heads and peel with their mass proportion of 83.19%, 5.01% and 14.19% by fresh weight, respectively. Among four solvents tested, methanol obtained the highest levels of extraction yield (54.02% by dry weight, total phenolic content (9.02 mg GAE/g dry weight and antioxidant capacity (DPPH radical scavenging capacity, cupric ion reducing antioxidant capacity, and ferric reducing antioxidant power from carrot peel, while water extracted the highest content of saponins (272.9 mg EE/g dry weight and possessed the maximum ABTS radical scavenging capacity. Therefore, methanol and water are considered for effective extraction of phenolics and saponins from carrot peel, respectively. The phenolic/saponin-enriched extracts are potential sources for further applications in the healthy food and/or pharmaceutical industries.

  4. Angiotensin I-converting enzyme inhibitory activity and antioxidant capacity of bioactive peptides derived from enzymatic hydrolysis of buffalo milk proteins

    DEFF Research Database (Denmark)

    Abdel-Hamid, Mahmoud; Otte, Jeanette; De Gobba, Cristian

    2017-01-01

    was hydrolysed using papain, pepsin or trypsin. The papain hydrolysate showed the highest ACE-inhibitory activity and radical scavenging capacity and was fractionated by size exclusion chromatography (SEC) and characterized by LC-MS analysis. A SEC-fraction with intermediate peptide size showed very high ACE...

  5. Antioxidant capacity and polyphenolic content of blueberry (Vaccinium corymbosum L.) leaf infusions.

    Science.gov (United States)

    Piljac-Zegarac, J; Belscak, A; Piljac, A

    2009-06-01

    Antioxidant capacity and polyphenolic content of leaf infusions prepared from six highbush blueberry cultivars (Vaccinium corymbosum L.), one wild lowbush blueberry cultivar (Vaccinium myrtillus L.), and one commercially available mix of genotypes were determined. In order to simulate household tea preparation conditions, infusions were prepared in water heated to 95 degrees C. The dynamics of extraction of polyphenolic antioxidants were monitored over the course of 30 minutes. Extraction efficiency, quantified in terms of the total phenol (TP) content, and antioxidant capacity of infusions, evaluated by the ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging assays, were compared with cultivar type and extraction time. The 30-minute infusions exhibited the highest TP content and antioxidant capacity according to all three assays. Wild blueberry infusion had the highest TP content (1,879 mg/L gallic acid equivalents [GAE]) and FRAP values (20,050 microM). The range of TP values for 30-minute infusions was 394-1,879 mg/L GAE with a mean of 986 mg/L GAE across cultivars; FRAP values fell between 3,015 and 20,050 microM with a mean of 11,234 microM across cultivars. All 30-minute infusions exhibited significant scavenging capacity for DPPH(*) and ABTS(*+) radicals, comparable to different concentrations of catechin, gallic acid, and 6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid. Overall, tested infusions showed significant reducing capacity as well as radical scavenging potential, which places blueberry leaf tea high on the list of dietary sources of antioxidants.

  6. Evaluation of railway capacity

    DEFF Research Database (Denmark)

    Landex, Alex; Kaas, Anders H.; Schittenhelm, Bernd

    2006-01-01

    capacity consumptions. This paper describes the UIC 406 method and how it is expounded in Denmark. The paper describes the importance of choosing the right length of the line sections examined and how line sections with multiple track sections are examined. Furthermore, the possibility of using idle...

  7. Markets and Institutional Capacity

    DEFF Research Database (Denmark)

    Ingemann, Jan Holm

    2010-01-01

    Adequate explanations concerning the introduction of production and consumption of organic food in Denmark imply the necessity to engage a certain understanding of markets. Markets should subsequently not be seen as entities nor places but as complex relations between human actors. Further......, the establishment, maintenance and development of markets are depending on the capacity of the actors to enter into continuous and enhancing interplay....

  8. Phytochemicals and Antioxidant Capacity from Nypa fruticans Wurmb. Fruit

    Science.gov (United States)

    Prasad, Nagendra; Yang, Bao; Kong, Kin Weng; Khoo, Hock Eng; Sun, Jian; Azlan, Azrina; Ismail, Amin; Romli, Zulfiki Bin

    2013-01-01

    Nypa fruticans Wurmb. is one of the important underutilized fruit of Malaysia, which lacks scientific attention. Total phenolics, flavonoid content, and antioxidant capacities from endosperm extracts of Nypa fruticans (unripe and ripe fruits) were evaluated. Endosperm extract of unripe fruits (EEU) exhibited the highest phenolics (135.6 ± 4.5 mg GAE/g), flavonoid content (68.6 ± 3.1 RE/g), and antioxidant capacity. Free radical scavenging capacity of EEU as assessed by 2-2′-azino-bis (3-ethylbenz-thiazoline-6-sulfonic acid (ABTS) and 1,1-diphenyl-2-picryl hydrazyl (DPPH) radicals showed inhibitory activity of 78 ± 1.2% and 85 ± 2.6%, respectively. Beta carotene bleaching coefficient of EEU was higher (2550 ± 123), when compared to endosperm extract of ripe fruits (1729 ± 172). Additionally, EEU exhibited high antioxidant capacity by phosphomolybdenum method and ferric reducing antioxidant power values. Eight phenolic compounds from Nypa fruticans endosperm extracts were identified and quantified by ultra-high-performance liquid chromatography. Chlorogenic acid, protocatechuic acid, and kaempferol were the major phenolic compounds. Thus this fruit could be used as a potential source of natural antioxidant. PMID:23710209

  9. Phenolic Compounds of Cereals and Their Antioxidant Capacity.

    Science.gov (United States)

    Van Hung, Pham

    2016-01-01

    Phenolic compounds play an important role in health benefits because of their highly antioxidant capacity. In this review, total phenolic contents (TPCs), phenolic acid profile and antioxidant capacity of the extracted from wheat, corn, rice, barley, sorghum, rye, oat, and millet, which have been recently reported, are summarized. The review shows clearly that cereals contain a number of phytochemicals including phenolics, flavonoids, anthocyanins, etc. The phytochemicals of cereals significantly exhibit antioxidant activity as measured by trolox equivalent antioxidant capacity (TEAC), 2,2-diphenyl-1-picrylhydrazyl radical scavenging, reducing power, oxygen radical absorbance capacity (ORAC), inhibition of oxidation of human low-density lipoprotein (LDL) cholesterol and DNA, Rancimat, inhibition of photochemilumenescence (PCL), and iron(II) chelation activity. Thus, the consumption of whole grains is considered to have significantly health benefits in prevention from chronic diseases such as cardiovascular disease, diabetes, and cancer because of the contribution of phenolic compounds existed. In addition, the extracts from cereal brans are considered to be used as a source of natural antioxidants.

  10. Evaluation of antioxidant capacity of Aidia borneensis leaf infusion, an endemic plant in Brunei Darussalam

    Directory of Open Access Journals (Sweden)

    Metussin, N.,

    2017-08-01

    Full Text Available We investigated the total antioxidant capacity of Aidia borneensis leaf infusion, a Bornean endemic plant, which is traditionally consumed as a home-remedy beverage in Brunei Darussalam. The antioxidant capacity of the infusion of A. borneensis leaves was evaluated by 2,2-diphenyl-1-picryhydrazyl (DPPH radical-scavenging ability. We found that the infusion shows a relatively high antioxidant capacity, and it was attributed to its high phenolic, flavonoid, and flavanol contents which were evaluated by Folin–Ciocalteu reagent, colorimetric assay, and aluminum chloride colorimetric method, respectively. By comparing its total antioxidant capacity, we estimated that the infusion of A. borneensis leaves is in the middle rank among twelve different commercially available Camellia sinensis teas. Our findings would have significant implications on A. borneensis products from Brunei Darussalam and on the feasibility of establishing this new beverage among the commercially available conventional C. sinensis and herbal teas.

  11. Radical-scavenging Activity of Natural Methoxyphenols vs. Synthetic Ones using the Induction Period Method

    Directory of Open Access Journals (Sweden)

    Seiichiro Fujisawa

    2007-02-01

    Full Text Available The radical-scavenging activities of the synthetic antioxidants 2-allyl-4-X-phenol (X=NO2, Cl, Br, OCH3, COCH3, CH3, t-(CH33, C6H5 and 2,4-dimethoxyphenol, and the natural antioxidants eugenol and isoeugenol, were investigated using differential scanning calorimetry (DSC by measuring their anti-1,1-diphenyl-2-picrylhydrazyl (DPPH radical activity and the induction period for polymerization of methyl methacrylate (MMA initiated by thermal decomposition of 2,2'-azobisisobutyronitrile (AIBN and benzoyl peroxide (BPO. 2-Allyl-4-methoxyphenol and 2,4-dimethoxy-phenol scavenged not only oxygen-centered radicals (PhCOO. derived from BPO, but also carbon-centered radicals (R. derived from the AIBN and DPPH radical much more efficiently, in comparison with eugenol and isoeugenol. 2-Allyl-4-methoxyphenol may be useful for its lower prooxidative activity.

  12. Direct degradation of dyes by piezoelectric fibers through scavenging low frequency vibration

    Science.gov (United States)

    Zhu, Ruijian; Xu, Yunhua; Bai, Qing; Wang, Zengmei; Guo, Xinli; Kimura, Hideo

    2018-06-01

    A newly discovered nanometer material-mediated piezoelectrochemical (PZEC) for the direct conversion of mechanical energy to chemical energy has attracted increasing attention, for its great potential to be a green dye water decomposition technique. However, it is far from being a cost-effective and practical technique because only ultrasonic can be scavenged to decomposed organic pollutant in previous studies. Here, we prepared 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 (BZT-BCT) piezoelectric fibers for the degradation of dye solution via slow stirring and studied the degradation mechanism. It provides a practical, green and low-cost method for decomposing organic dye by scavenging waste mechanical energy from the surrounding environment.

  13. Using the EDTA Hole Scavenger to Accelerate Decolorization in the Immobilized Photocatalytic Process

    Directory of Open Access Journals (Sweden)

    raziye Asgari

    2015-07-01

    Full Text Available This study investigated the effect of EDTA as a hole scavenger on accelerating the photocatalytic decolorization of direct blue 71 as a non-degradable model pollutant with nano TiO2 powder immobilized on a cementitious bed. For this purpose, 75 mg/L of the dye was decolorized in 75 minutes with 0.03 M of EDTA at a pH level of 6 and under irradiation produced by a 60-W UV-C lamp. This is while decolorization under identical conditions but in the absence of EDTA had been accomplished in 225 minutes. The experiment, therefore, confirmed the accelerating effect of the scavenger on decolorization. The kinetics of the photocatalytic process with EDTA followed a first order reaction with a constant rate of 0.05 min-1, which is 2.5 times faster than the process without EDTA.

  14. Antinociceptive and free radical scavenging activities of Cocos nucifera L. (Palmae) husk fiber aqueous extract.

    Science.gov (United States)

    Alviano, Daniela S; Rodrigues, Karen F; Leitão, Suzana G; Rodrigues, Marcio L; Matheus, Maria Eline; Fernandes, Patrícia D; Antoniolli, Angelo R; Alviano, Celuta S

    2004-06-01

    In the current study, the analgesic and free radical scavenging properties of an aqueous extract from the husk fiber of Cocos nucifera L. (Palmae) were demonstrated by the use of in vivo and in vitro models. The orally administered Cocos nucifera aqueous extract (200 or 400 mg/kg) inhibited the acetic acid-induced writhing response in mice. Tail flick and hot plate assays demonstrated that treatment of animals with this plant extract at 200 mg/kg induced attenuation in the response to a heat stimulus. A LD(50) of 2.30 g/kg was obtained in acute toxicity tests. Topic treatment of rabbits with the Cocos nucifera extract indicated that it does not induce any significant dermic or ocular irritation. In vitro experiments using the 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) photometric assay demonstrated that this plant extract also possesses free radical scavenging properties.

  15. Reduction of cathodic delamination rates of anticorrosive coatings using free radical scavengers

    DEFF Research Database (Denmark)

    Sørensen, Per Aggerholm; Weinell, C. E.; Dam-Johansen, Kim

    2010-01-01

    Cathodic delamination is one of the major modes of failure for anticorrosive coatings subjected to a physical damage and immersed in seawater. The cause of cathodic delamination has been reported to be the result of a chemical attack at the coating-steel interface by free radicals and peroxides...... formed as intermediates in the cathodic reaction during the corrosion process. In this study, antioxidants (i.e., free radical scavengers and peroxide decomposers) have been incorporated into various generic types of coatings to investigate the effect of antioxidants on the rate of cathodic delamination...... of epoxy coatings on cold rolled steel. The addition of free radical scavengers to epoxy coatings improved the resistance toward cathodic delamination by up to 50% during seawater immersion, while peroxide decomposers had a limited effect. Testing using substrates prepared from stainless steel...

  16. Free radical scavenging activity and lipoxygenase inhibition of Mahonia aquifolium extract and isoquinoline alkaloids

    Directory of Open Access Journals (Sweden)

    Kettmann Viktor

    2007-07-01

    Full Text Available Abstract Roots and stem-bark of Mahonia aquifolium (Oregon grape (Berberidaceae are effectively used in the treatment of skin inflammatory conditions. In the present study, the effect of Mahonia aquifolium crude extract and its two representative alkaloid fractions containing protoberberine and bisbenzylisoquinoline (BBIQ alkaloids on activity of 12-lipoxygenase (12-LOX, was studied. The reactivity with 1,1-diphenyl-2-picryl-hydrazyl (DPPH, a free stable radical, was evaluated to elucidate the rate of possible lipid-derived radical scavenging in the mechanism of the enzyme inhibition. The results indicate that although the direct radical scavenging mechanism cannot be ruled out in the lipoxygenase inhibition by Mahonia aquifolium and its constituents, other mechanisms based on specific interaction between enzyme and alkaloids could play the critical role in the lipoxygenase inhibition rather than non-specific reactivity with free radicals.

  17. A One-Structure-Based Multieffects Coupled Nanogenerator for Simultaneously Scavenging Thermal, Solar, and Mechanical Energies.

    Science.gov (United States)

    Ji, Yun; Zhang, Kewei; Yang, Ya

    2018-02-01

    Rapid advances in various energy harvesters impose the challenge on integrating them into one device structure with synergetic effects for full use of the available energies from the environment. Here, a multieffect coupled nanogenerator based on ferroelectric barium titanate is reported. It promotes the ability to simultaneously scavenging thermal, solar, and mechanical energies. By integration of a pyroelectric nanogenerator, a photovoltaic cell, and a triboelectric-piezoelectric nanogenerator in one structure with only two electrodes, multieffects interact with each other to alter the electric output, and a complementary power source with peak current of ≈1.5 µA, peak voltage of ≈7 V, and platform voltage of ≈6 V is successfully achieved. Compared with traditional hybridized nanogenerators with stacked architectures, the one-structure-based multieffects coupled nanogenerator is smaller, simpler, and less costly, showing prospective in practical applications and represents a new trend of all-in-one multiple energy scavenging.

  18. The evaluation of secondary system oxygen-scavenging chemicals using a water-circulating rig

    Energy Technology Data Exchange (ETDEWEB)

    Collins, M.W. [Nuclear Dept., HMS Sultan (United Kingdom)

    2002-07-01

    To assess the efficiency, mode of action and possible by-products of chemical dosing agents, e.g. oxygen scavengers, a circulating water rig was constructed. The rig uses a demineralized water supply as a source of make-up water to fill a recirculating loop of approx. 10 litres volume. The rig pipework is made of polythene with standard off-the shelf pipe fittings and connectors. The following parameters can be measured within the rig: pH and conductivity measured by in-line monitor, dissolved oxygen level, temperature. The system has already been used for some preliminary testing. The following oxygen scavengers have been used for tests: ascorbic acid (vitamin C), N,N-diethyl-hydroxylamine (DEHA), Hydroquinone, hydrazine hydrate and anhydrous sodium sulfite. (authors)

  19. Efficient scavenging of β-carotene radical cations by antiinflammatory salicylates

    DEFF Research Database (Denmark)

    Cheng, Hong; Liang, Ran; Han, Rui-Min

    2014-01-01

    by the anion of salicylic acid with 2.2 × 10 L mol s, but still of possible importance for light-exposed tissue. Surprisingly, acetylsalicylate, the aspirin anion, reacts with an intermediate rate in a reaction assigned to the anion of the mixed acetic-salicylic acid anhydride formed through base induced......The radical cation generated during photobleaching of β-carotene is scavenged efficiently by the anion of methyl salicylate from wintergreen oil in a second-order reaction approaching the diffusion limit with k = 3.2 × 10 L mol s in 9:1 v/v chloroform-methanol at 23 °C, less efficiently...... rearrangements. The relative scavenging rate of the β-carotene radical cation by the three salicylates is supported by DFT-calculations....

  20. The macrophage scavenger receptor (CD163): a double-edged sword in treatment of malignant disease

    DEFF Research Database (Denmark)

    Maniecki, Maciej Bogdan

    2009-01-01

    of inflammatory processes. The receptor is expressed by circulatory monocytes and it is highly expressed on tissue-resident macrophages. CD163 is also expressed on leukemic blast cells of AML type M4/M5 and tumor cells in malignant melanoma and breast cancer. Although circumstantial evidence of the potential...... was investigated in biopsies from bladder cancer patients. We demonstrated that CD163 mRNA expression was significantly elevated in muscle invasive tumors (T2-T4) compared with superficial tumors (Ta), and that a high level of CD163 mRNA expression in tumor biopsies was significantly associated with poor 13-year......The hemoglobin scavenger receptor CD163 is a transmembrane glycoprotein belonging to the scavenger receptor cysteine-rich (SRCR) domain family. It mediates the clearance of hemoglobin released to the circulation during intravascular hemolysis, and it is also involved in the regulation...

  1. The LOX-1 Scavenger Receptor and Its Implications in the Treatment of Vascular Disease

    Directory of Open Access Journals (Sweden)

    M. W Twigg

    2012-01-01

    Full Text Available Cardiovascular disease is the leading cause of death. The disease is due to atherosclerosis which is characterized by lipid and fat accumulation in arterial blood vessel walls. A key causative event is the accumulation of oxidised low density lipoprotein particles within vascular cells, and this is mediated by scavenger receptors. One such molecule is the LOX-1 scavenger receptor that is expressed on endothelial, vascular smooth muscle, and lymphoid cells including macrophages. LOX-1 interaction with OxLDL particles stimulates atherosclerosis. LOX-1 mediates OxLDL endocytosis via a clathrin-independent internalization pathway. Transgenic animal model studies show that LOX-1 plays a significant role in atherosclerotic plaque initiation and progression. Administration of LOX-1 antibodies in cellular and animal models suggest that such intervention inhibits atherosclerosis. Antiatherogenic strategies that target LOX-1 function using gene therapy or small molecule inhibitors would be new ways to address the increasing incidence of vascular disease in many countries.

  2. Increasing the Air Charge and Scavenging the Clearance Volume of a Compression-Ignition Engine

    Science.gov (United States)

    Spanogle, J A; Hicks, C W; Foster, H H

    1934-01-01

    The object of the investigation presented in this report was to determine the effects of increasing the air charge and scavenging the clearance volume of a 4-stroke-cycle compression-ignition engine having a vertical-disk form combustion chamber. Boosting the inlet-air pressure with normal valve timing increased the indicated engine power in proportion to the additional air inducted and resulted in smoother engine operation with less combustion shock. Scavenging the clearance volume by using a valve overlap of 145 degrees and an inlet-air boost pressure of approximately 2 1/2 inches of mercury produced a net increase in performance for clear exhaust operation of 33 percent over that obtained with normal valve timing and the same boost pressure. The improved combustion characteristics result in lower specific fuel consumption, and a clearer exhaust.

  3. Antioxidant and free radical scavenging activities of Gastrodia elata Bl. and Uncaria rhynchophylla (Miq.) Jacks.

    Science.gov (United States)

    Liu, J; Mori, A

    1992-12-01

    Gastrodia elata Bl. (GE) and Uncaria rhynchophylla (Miq.) Jacks (UR) are two traditional Chinese medicinal herbal drugs, used for the treatment of convulsions and epilepsy. Their antioxidant effects in vivo and their free radical scavenging effects in vitro were investigated. Epileptogenic foci in the lateral brain of the rat were induced by the injection of ferric chloride into the lateral cortex. Both extracts significantly inhibited the increase in levels of lipid peroxide in the ipsilateral cortex, at all times observed. In addition, the two extracts also induced an early increase of activity of superoxide dismutase in the mitochondrial fraction of the ipsilateral cortex. In in vitro experiments, the two extracts exhibited significant dose-dependent scavenging effects on free radicals, using electron spin resonance spectroscopy. These results suggest that the proposed antiepileptic effects of GE and UR may be attributable to the antioxidant activity of the active components in these two medicinal herbs.

  4. The evaluation of secondary system oxygen-scavenging chemicals using a water-circulating rig

    International Nuclear Information System (INIS)

    Collins, M.W.

    2002-01-01

    To assess the efficiency, mode of action and possible by-products of chemical dosing agents, e.g. oxygen scavengers, a circulating water rig was constructed. The rig uses a demineralized water supply as a source of make-up water to fill a recirculating loop of approx. 10 litres volume. The rig pipework is made of polythene with standard off-the shelf pipe fittings and connectors. The following parameters can be measured within the rig: pH and conductivity measured by in-line monitor, dissolved oxygen level, temperature. The system has already been used for some preliminary testing. The following oxygen scavengers have been used for tests: ascorbic acid (vitamin C), N,N-diethyl-hydroxylamine (DEHA), Hydroquinone, hydrazine hydrate and anhydrous sodium sulfite. (authors)

  5. Neuronal discrimination capacity

    International Nuclear Information System (INIS)

    Deng Yingchun; Williams, Peter; Feng Jianfeng; Liu Feng

    2003-01-01

    We explore neuronal mechanisms of discriminating between masked signals. It is found that when the correlation between input signals is zero, the output signals are separable if and only if input signals are separable. With positively (negatively) correlated signals, the output signals are separable (mixed) even when input signals are mixed (separable). Exact values of discrimination capacity are obtained for two most interesting cases: the exactly balanced inhibitory and excitatory input case and the uncorrelated input case. Interestingly, the discrimination capacity obtained in these cases is independent of model parameters, input distribution and is universal. Our results also suggest a functional role of inhibitory inputs and correlated inputs or, more generally, the large variability of efferent spike trains observed in in vivo experiments: the larger the variability of efferent spike trains, the easier it is to discriminate between masked input signals

  6. Seismic capacity of switchgear

    International Nuclear Information System (INIS)

    Bandyopadhyay, K.; Hofmayer, C.; Kassir, M.; Pepper, S.

    1989-01-01

    As part of a component fragility program sponsored by the USNRC, BNL has collected existing information on the seismic capacity of switchgear assemblies from major manufacturers. Existing seismic test data for both low and medium voltage switchgear assemblies have been evaluated and the generic results are presented in this paper. The failure modes are identified and the corresponding generic lower bound capacity levels are established. The test response spectra have been used as a measure of the test vibration input. The results indicate that relays chatter at a very low input level at the base of the switchgear cabinet. This change of state of devices including relays have been observed. Breaker tripping occurs at a higher vibration level. Although the structural failure of internal elements have been noticed, the overall switchgear cabinet structure withstands a high vibration level. 5 refs., 2 figs., 2 tabs

  7. Neuronal discrimination capacity

    Energy Technology Data Exchange (ETDEWEB)

    Deng Yingchun [Department of Mathematics, Hunan Normal University 410081, Changsha (China); COGS, University of Sussex at Brighton, BN1 9QH (United Kingdom); Williams, Peter; Feng Jianfeng [COGS, University of Sussex at Brighton, BN1 9QH (United Kingdom); Liu Feng [COGS, University of Sussex at Brighton, BN1 9QH (United Kingdom); Physics Department, Nanjing University (China)

    2003-12-19

    We explore neuronal mechanisms of discriminating between masked signals. It is found that when the correlation between input signals is zero, the output signals are separable if and only if input signals are separable. With positively (negatively) correlated signals, the output signals are separable (mixed) even when input signals are mixed (separable). Exact values of discrimination capacity are obtained for two most interesting cases: the exactly balanced inhibitory and excitatory input case and the uncorrelated input case. Interestingly, the discrimination capacity obtained in these cases is independent of model parameters, input distribution and is universal. Our results also suggest a functional role of inhibitory inputs and correlated inputs or, more generally, the large variability of efferent spike trains observed in in vivo experiments: the larger the variability of efferent spike trains, the easier it is to discriminate between masked input signals.

  8. Riboflavin Phototransformation on the Changes of Antioxidant Capacities in Phenolic Compounds.

    Science.gov (United States)

    Song, Juhee; Seol, Nam Gyu; Kim, Mi-Ja; Lee, JaeHwan

    2016-08-01

    Eight phenolic compounds including: p-coumaric acid, vanillic acid, caffeic acid, chlorogenic acid, trolox, quercetin, curcumin, and resveratrol were treated with riboflavin (RF) photosensitization and in vitro antioxidant capacities of the mixtures were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2' azino bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays. Mixtures containing p-coumaric acid and vanillic acid under RF photosensitization showed increases in ferric ion reducing ability and radical scavenging activity of DPPH, whereas mixtures of other compounds had decreases in both radical scavenging ability and ferric reducing antioxidant power. Hydroxycoumaric acid and conjugated hydroxycoumaric and coumaric acids were tentatively identified from RF photosensitized p-coumaric acid, whereas dimmers of vanillic acid were tentatively identified from RF photosensitized vanillic acid. RF photosensitization may be a useful method to enhance antioxidant properties like ferric ion reducing abilities of some selected phenolic compounds. © 2016 Institute of Food Technologists®

  9. PAYMENT CAPACITY SENSITIVITY FACTORS

    OpenAIRE

    Daniel BRÎNDESCU – OLARIU

    2014-01-01

    The current study focuses on the sensitivity of the corporate payment capacity. Through the nature of the subject, the research is based on simulating variations of the forecasted cash-flows of the companies included in the sample. The study employs 391 forecasted yearly cash-flows statements collected from 50 companies from Timis County (Romania), as well as the detailed hypotheses of the forecasts. The results of the study facilitate the determination and classification of the main se...

  10. Options on capacity imbalance

    International Nuclear Information System (INIS)

    Roggen, M.

    2002-01-01

    Since the start of this year, the Dutch energy company Nuon has been using a computer system to formulate real-time responses to national capacity imbalances in the electricity supply market. The work earns Nuon a fixed fee from TenneT (Dutch Transmission System Operator) and ensures a more stable imbalance price for everyone. The key to success has been the decision to start the project from scratch [nl

  11. Efficacy of Odor Scavengers in Reducing Odor Compounds in Water, Milk, and Soymilk

    OpenAIRE

    Norton, Jenny Lynn

    2003-01-01

    Odor detection thresholds of hexanal, 2-heptenal, 2-pentanone, and 2,4-nonadienal were determined in spring water, high temperature short time (HTST) 2% fat milk, and extended shelf life soymilk. The efficacy of odor scavenger's beta-cyclodextrin, D-sorbitol, and nylon 6 in removing these odors was also determined. The odor thresholds of the different odor and media combinations were as follows: hexanal in spring water, milk, and soymilk were 585, 339, and 536 ppb respectively; 2-heptenal ...

  12. Direct antioxidant properties of methotrexate: Inhibition of malondialdehyde-acetaldehyde-protein adduct formation and superoxide scavenging

    Directory of Open Access Journals (Sweden)

    Matthew C. Zimmerman

    2017-10-01

    Full Text Available Methotrexate (MTX is an immunosuppressant commonly used for the treatment of autoimmune diseases. Recent observations have shown that patients treated with MTX also exhibit a reduced risk for the development of cardiovascular disease (CVD. Although MTX reduces systemic inflammation and tissue damage, the mechanisms by which MTX exerts these beneficial effects are not entirely known. We have previously demonstrated that protein adducts formed by the interaction of malondialdehyde (MDA and acetaldehyde (AA, known as MAA-protein adducts, are present in diseased tissues of individuals with rheumatoid arthritis (RA or CVD. In previously reported studies, MAA-adducts were shown to be highly immunogenic, supporting the concept that MAA-adducts not only serve as markers of oxidative stress but may have a direct role in the pathogenesis of inflammatory diseases. Because MAA-adducts are commonly detected in diseased tissues and are proposed to mitigate disease progression in both RA and CVD, we tested the hypothesis that MTX inhibits the generation of MAA-protein adducts by scavenging reactive oxygen species. Using a cell free system, we found that MTX reduces MAA-adduct formation by approximately 6-fold, and scavenges free radicals produced during MAA-adduct formation. Further investigation revealed that MTX directly scavenges superoxide, but not hydrogen peroxide. Additionally, using the Nrf2/ARE luciferase reporter cell line, which responds to intracellular redox changes, we observed that MTX inhibits the activation of Nrf2 in cells treated with MDA and AA. These studies define previously unrecognized mechanisms by which MTX can reduce inflammation and subsequent tissue damage, namely, scavenging free radicals, reducing oxidative stress, and inhibiting MAA-adduct formation.

  13. Assessment of a chemical getter for scavenging tritium from an inert gas

    International Nuclear Information System (INIS)

    Maienschein, J.L.

    1976-01-01

    Results are presented of a study aimed at determining the feasibility of using chemical getter beds to scavenge tritium from inert gases. Two types of getter bed, fixed and fluidized, were considered, using cerium as the getter material. Mathematical-modeling results and capital-cost estimates indicate that not only is the gettering approach technically feasible, it could lead to considerable cost savings over catalytic oxidation, the tritium-removal method traditionally used

  14. Scavenger removal: Bird and bat carcass persistence in a tropical wind farm

    Science.gov (United States)

    Villegas-Patraca, Rafael; Macías-Sánchez, Samuel; MacGregor-Fors, Ian; Muñoz-Robles, Carlos

    2012-08-01

    Energy produced by wind farms has diverse positive environmental effects, but can also be related to negative impacts, including wildlife mortality through collisions with wind turbines. Bird and bat mortality caused by collisions with wind turbines can be estimated indirectly by counting carcasses within wind farms. However, carcass removal by scavengers often biases such measurements. In this study, we identified the main scavengers removing bird and bat carcasses in a tropical wind farm. A known fate analysis was done to assess the effect of carcass type (i.e., small bird, large bird, bat), vegetation type (i.e., secondary vegetation, croplands) and season (dry and rainy seasons of 2009) on carcass persistence rates. We identified three main scavenger groups, with mammals being the most abundant group. Our results show high rates of carcass removal relative to previous studies, especially for bats; there were fewer remaining carcasses after 20 days in our tropical site than in non-tropical environments reported elsewhere. We found a higher carcass persistence rate during the rainy season than in the dry season, possibly due to a greater abundance of food resources for scavenger organisms in the rainy season. Although we found some evidence for higher persistence rates for large bird carcasses than for small bird and bat carcasses during the rainy season, overall carcass type was not a strong predictor of persistence rates. Similarly, we did not find a strong effect of vegetation type on carcass persistence rates. Results suggest that in order to estimate accurate bird and bat mortality in tropical wind farm areas, seasonality should be incorporated to correction factors of carcass removal rates.

  15. The use of peppermint Leaves as scavengers Of lead Π ions

    International Nuclear Information System (INIS)

    EL-Sheikh, A.; El-Khatib; Naddaf, A.

    2002-01-01

    Peppermint Leaves were examined to be scavengers in removing lead from its aqueous medium. Different factors have been studied. These factors include leaf content, initial lead concentration, drying the leaves, ph, crushing the leaves, agitating the solution, type of leaf sample, and the presence of competing ions as well as complexing agents. The present results prove that the interaction between lead ions and peppermint leaves is mainly an adsorption process and obeys Freundlich adsorption isotherm. ( Author's) 18 refs., 12 figs., 3 tabs

  16. Extraction method for high free radical scavenging activity of Siamese neem tree flowers

    Directory of Open Access Journals (Sweden)

    Worarat Chaisawangwong

    2009-10-01

    Full Text Available Siamese neem tree (Azadirachta indica A. Juss. var. siamensis Valeton is a medicinal plant found in Thailand. Youngleaves and young flowers of this plant are commonly consumed as a bitter tonic vegetable. The flowers are also used fortreatment of fever. The flower extract has been reported to exhibit in vitro free radical scavenging activity and can inhibitlipid peroxidation of bronchogenic cancer cell line. Active compounds in the flowers are flavonoids such as rutin andquercetin. The content of these compounds in the crude extract depends on the method of extraction. Therefore, the appropriateextraction method promoting high yield of total flavonoids and high free radical scavenging activity was investigated inthis study. Six different extraction methods, i.e. maceration, percolation, decoction, soxhlet extraction, ultrasonic extraction(UE, and microwave assisted extraction (MA were carried out for extracting dried powder of Siamese neem tree young flowers. The solvent used for maceration, percolation, and soxhlet extraction was 50% ethanol, while distilled water was used for decoction and MA, and both solvents were used for UE. The content of crude extract, free radical scavenging activity, and total flavonoids content of each extract were investigated and compared. Comparing the various extraction methods, decoction provided an extract containing a high amount of total flavonoids (17.54 mgRE/g extract and promoting the highest scavenging activity at EC50 11.36 g/ml. Decoction is also simple, cheap, and convenient and could be used in developing countries. Thus, it should be the recommended extraction method for the flowers of Siamese neem tree for furtherdevelopment of antioxidant pharmaceutical preparations.

  17. Culture- and molecular-based detection of swine-adapted Salmonella shed by avian scavengers.

    Science.gov (United States)

    Blanco, Guillermo; Díaz de Tuesta, Juan A

    2018-04-13

    Salmonella can play an important role as a disease agent in wildlife, which can then act as carriers and reservoirs of sanitary importance at the livestock-human interface. Transmission from livestock to avian scavengers can occur when these species consume contaminated carcasses and meat remains in supplementary feeding stations and rubbish dumps. We compared the performance of PCR-based detection with conventional culture-based methods to detect Salmonella in the faeces of red kites (Milvus milvus) and griffon vultures (Gyps fulvus) in central Spain. The occurrence of culturable Salmonella was intermediate in red kites (1.9%, n=52) and high in griffon vultures (26.3%, n=99). These proportions were clearly higher with PCR-based detection (13.5% and 40.4%, respectively). Confirmation cultures failed to grow Salmonella in all faecal samples positive by the molecular assay but negative by the initial conventional culture in both scavenger species, indicating the occurrence of false (non-culturable) positives by PCR-based detection. This suggests that the molecular assay is highly sensitive to detecting viable Salmonella in cultures, but also partial genomes and dead or unviable bacteria from past infections or contamination. Thus, the actual occurrence of Salmonella in a particular sampling time period can be underestimated when using only culture detection. The serovars found in the scavenger faeces were among the most frequently isolated in pigs from Spain and other EU countries, especially those generally recognized as swine-adapted monophasic variants of S. Typhimurium. Because the studied species obtain much of their food from pig carcasses, this livestock may be the primary source of Salmonella via direct ingestion of infected carcasses and indirectly via contamination due to the unsanitary conditions found in supplementary feeding stations established for scavenger conservation. Combining culture- and molecular-based detection is encouraged to understand the

  18. Scavenger receptor AI/II truncation, lung function and COPD: a large population-based study

    DEFF Research Database (Denmark)

    Thomsen, M; Nordestgaard, B G; Tybjærg-Hansen, Anne

    2011-01-01

    The scavenger receptor A-I/II (SRA-I/II) on alveolar macrophages is involved in recognition and clearance of modified lipids and inhaled particulates. A rare variant of the SRA-I/II gene, Arg293X, truncates the distal collagen-like domain, which is essential for ligand recognition. We tested...... whether the Arg293X variant is associated with reduced lung function and risk of chronic obstructive pulmonary disease (COPD) in the general population....

  19. Potent Antioxidative Activity of Lycopene: A Potential Role in Scavenging Hypochlorous Acid †

    OpenAIRE

    Pennathur, Subramaniam; Maitra, Dhiman; Byun, Jaeman; Sliskovic, Inga; Abdulhamid, Ibrahim; Saed, Ghassan M.; Diamond, Michael P.; Abu-Soud, Husam M.

    2010-01-01

    Lycopene, a carotenoid found in tomatoes, is a proven anti-oxidant that may lower the risk of certain disorders including heart disease and cancer. Hypochlorous acid (HOCl) is an oxidant linked to tissue oxidation in cardiovascular disease and other inflammatory disorders through its ability to modify proteins, deoxyribonucleic acid, ribonucleic acid and lipids. Here we show that lycopene can function as a potent scavenger of HOCl at a wide range of concentrations that span various pathophysi...

  20. Invasive carnivores alter ecological function and enhance complementarity in scavenger assemblages on ocean beaches.

    Science.gov (United States)

    Brown, Marion B; Schlacher, Thomas A; Schoeman, David S; Weston, Michael A; Huijbers, Chantal M; Olds, Andrew D; Connolly, Rod M

    2015-10-01

    Species composition is expected to alter ecological function in assemblages if species traits differ strongly. Such effects are often large and persistent for nonnative carnivores invading islands. Alternatively, high similarity in traits within assemblages creates a degree of functional redundancy in ecosystems. Here we tested whether species turnover results in functional ecological equivalence or complementarity, and whether invasive carnivores on islands significantly alter such ecological function. The model system consisted of vertebrate scavengers (dominated by raptors) foraging on animal carcasses on ocean beaches on two Australian islands, one with and one without invasive red foxes (Vulpes vulpes). Partitioning of scavenging events among species, carcass removal rates, and detection speeds were quantified using camera traps baited with fish carcasses at the dune-beach interface. Complete segregation of temporal foraging niches between mammals (nocturnal) and birds (diurnal) reflects complementarity in carrion utilization. Conversely, functional redundancy exists within the bird guild where several species of raptors dominate carrion removal in a broadly similar way. As predicted, effects of red foxes were large. They substantially changed the nature and rate of the scavenging process in the system: (1) foxes consumed over half (55%) of all carrion available at night, compared with negligible mammalian foraging at night on the fox-free island, and (2) significant shifts in the composition of the scavenger assemblages consuming beach-cast carrion are the consequence of fox invasion at one island. Arguably, in the absence of other mammalian apex predators, the addition of red foxes creates a new dimension of functional complementarity in beach food webs. However, this functional complementarity added by foxes is neither benign nor neutral, as marine carrion subsidies to coastal red fox populations are likely to facilitate their persistence as exotic

  1. CSTI High Capacity Power

    International Nuclear Information System (INIS)

    Winter, J.M.

    1989-01-01

    The SP-100 program was established in 1983 by DOD, DOE, and NASA as a joint program to develop the technology necessary for space nuclear power systems for military and civil application. During FY-86 and 87, the NASA SP-100 Advanced Technology Program was devised to maintain the momentum of promising technology advancement efforts started during Phase 1 of SP-100 and to strengthen, in key areas, the chances for successful development and growth capability of space nuclear reactor power systems for future space applications. In FY-88, the Advanced Technology Program was incorporated into NASA's new Civil Space Technology Initiative (CSTI). The CSTI Program was established to provide the foundation for technology development in automation and robotics, information, propulsion, and power. The CSTI High Capacity Power Program builds on the technology efforts of the SP-100 program, incorporates the previous NASA SP-100 Advanced Technology project, and provides a bridge to NASA Project Pathfinder. The elements of CSTI High Capacity Power development include Conversion Systems, Thermal Management, Power Management, System Diagnostics, and Environmental Interactions. Technology advancement in all areas, including materials, is required to assure the high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems. The overall program will develop and demonstrate the technology base required to provide a wide range of modular power systems as well as allowing mission independence from solar and orbital attitude requirements. Several recent advancements in CSTI High Capacity power development will be discussed

  2. Particle scavenging in a cylindrical ultrasonic standing wave field using levitated drops

    Science.gov (United States)

    Merrell, Tyler; Saylor, J. R.

    2015-11-01

    A cylindrical ultrasonic standing wave field was generated in a tube containing a flow of particles and fog. Both the particles and fog drops were concentrated in the nodes of the standing wave field where they combined and then grew large enough to fall out of the system. In this way particles were scavenged from the system, cleaning the air. While this approach has been attempted using a standing wave field established between disc-shaped transducers, a cylindrical resonator has not been used for this purpose heretofore. The resonator was constructed by bolting three Langevin transducers to an aluminum tube. The benefit of the cylindrical geometry is that the acoustic energy is focused. Furthermore, the residence time of the particle in the field can be increased by increasing the length of the resonator. An additional benefit of this approach is that tubes located downstream of the resonator were acoustically excited, acting as passive resonators that enhanced the scavenging process. The performance of this system on scavenging particles is presented as a function of particle diameter and volumetric flow rate. It is noted that, when operated without particles, the setup can be used to remove drops and shows promise for liquid aerosol retention from systems where these losses can be financially disadvantageous and/or hazardous.

  3. Microglial Scavenger Receptors and Their Roles in the Pathogenesis of Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Kim Wilkinson

    2012-01-01

    Full Text Available Alzheimer’s disease (AD is increasing in prevalence with the aging population. Deposition of amyloid-β (Aβ in the brain of AD patients is a hallmark of the disease and is associated with increased microglial numbers and activation state. The interaction of microglia with Aβ appears to play a dichotomous role in AD pathogenesis. On one hand, microglia can phagocytose and clear Aβ, but binding of microglia to Aβ also increases their ability to produce inflammatory cytokines, chemokines, and neurotoxic reactive oxygen species (ROS. Scavenger receptors, a group of evolutionally conserved proteins expressed on the surface of microglia act as receptors for Aβ. Of particular interest are SCARA-1 (scavenger receptor A-1, CD36, and RAGE (receptor for advanced glycation end products. SCARA-1 appears to be involved in the clearance of Aβ, while CD36 and RAGE are involved in activation of microglia by Aβ. In this review, we discuss the roles of various scavenger receptors in the interaction of microglia with Aβ and propose that these receptors play complementary, nonredundant functions in the development of AD pathology. We also discuss potential therapeutic applications for these receptors in AD.

  4. Total phenolic and phytosterol compounds and the radical scavenging activity of germinated Australian sweet lupin flour.

    Science.gov (United States)

    Rumiyati; Jayasena, Vijay; James, Anthony P

    2013-12-01

    In addition to their favourable nutritional profile, legumes also contain a range of bioactive compounds such as phenolic compounds and phytosterols which may protect against chronic diseases including cancer and cardiovascular disease. Germination of some legume seeds has been previously reported to increase the concentration of the bioactive compounds. In this study, the effect of germination of Australian Sweet Lupin (ASL) seeds for 9 days on the concentration of some bioactive compounds and the radical scavenging activity in the resulting flour was determined. The concentration of total phenolic compounds in methanolic extracts of germinated ASL flour was determined using Folin Ciocalteu reagent and phytosterols in oil extracts were analyzed by gas-liquid chromatography. The methanolic and oil extracts were also used to determine radical scavenging activity toward 2,2-diphenyl-1-picrylhydrazyl. In the methanolic extracts of germinated ASL flour, phenolic contents and the antioxidant activity were significantly increased following germination (700 and 1400 %, respectively). Analysis of the oil extracts of germinated ASL flour revealed that the concentration of phytosterols and the antioxidant activity were also increased significantly compared to ungerminated ASL flour (300 and 800 %, respectively). The relative proportion of phytosterols in germinated ASL flour was: β-sitosterol (60 %), stigmasterol (30 %) and campesterol (10 %). Germination increases the concentration of bioactive compounds and the radical scavenging activity in the germinated ASL flour.

  5. Free Radical Scavenging Activity and Anthocyanin Profile of Cabernet Sauvignon Wines from the Balkan Region

    Directory of Open Access Journals (Sweden)

    Blaga Radovanović

    2010-06-01

    Full Text Available The present study is focused on anthocyanin derivatives characterizing the antioxidant activity of Cabernet Sauvignon wines produced from different vineyard regions in the Balkans. These bioactive compounds were quantified with a high performance liquid chromatography (HPLC-diode array detection (DAD method. The antiradical activity was estimated by the ability of the wine to scavenge the stable 2,2`-diphenyl-1-picrylhydrazyl free radical (DPPH·. The results show that the total anthocyanin content varied from 205.88 to 1940.28 mg/L, depending on agroclimatic factors and the enological practices of the corresponding vineyard region. The most prominent antocyanin in all investigated Cabernet Sauvignon wines was malvidin-3-O-monoglucoside, which accounted for 50.57% of total content, followed by its acetyl derivatives, 15.45%, and p-coumaryl derivatives 5.66%. The relationship between the anthocyanin derivatives and free radical scavenging activity is discussed. A high correlation between total anthocyanin content and DPPH· scavenging ability of tested wines was confirmed (r2 = 0.9619. The significant correlations were obtained between antiradical activity and the sum of 3-monoglucoside (r2 = 0.95594, the sum of 3-acetyl-3-glucoside (r2 = 0.9728 and the sum of p-coumaryl-3-glucoside (r2 = 0.8873 of wine samples. It can be concluded that, the anthocyanin composition can be used as biochemical marker for the authenticity of red grape cultivar and their corresponding single-cultivar wine.

  6. Remarks relating to field experiments to measure the wet scavenging of tracer aerosols

    International Nuclear Information System (INIS)

    Stensland, G.J.

    1977-12-01

    An important question is whether or not the wet deposition of debris from a single (or multiple) airburst of a nuclear device poses a significant hazard to people on the ground. To answer this question for various scenarios, a basic understanding of the aerosol attachment rates to cloud water and raindrops is needed. The attachment rates can then be incorporated into the cloud physics scavenging models to make intelligent assessments. In order to gain an initial impression as to the importance (order of magnitude) of the wet scavenging effects and to provide the data to validate the cloud scavenging models, tracer release field experiments are useful and necessary. The major purpose of this report is to address questions related to the operation and interpretation of such field tracer efforts and in particular to consider the results from the August 3, 1972, Battelle Northwest Laboratory tracer experiment in St. Louis. The Battelle experiment involved the release of several aerosol tracers at 10,000 to 13,000 feet, near rain clouds, and the measurement of the resulting tracer in the rain collected at the ground level sampling sites

  7. Free radical scavenging activity of coenzyme Q measured by a chemiluminescent assay

    International Nuclear Information System (INIS)

    Battino, Maurizio; Ferri, Elida; Girotti, Stefano; Lenaz, Giorgio

    1991-01-01

    Involvement of coenzyme Q (CoQ) in anti-oxydant activities, in addition to its major redox role, has frequently been suggested in recent years. In order to elucidate if CoQ could really be engaged in scavenging free radicals produced endogenously in a biological system, an experimental system was developed in which beef heart mitochondria in the presence of a saturating NADH concentration and of rotenone produce free radicals. The presence of oxygen-reactive forms was easily detected by a luminol-dependent chemiluminescence process. The chemi-luminescence assay showed that short-chain CoQ homologues can act as pro-oxidants, enhancing free radical effects, while exogenous coenzyme Q 10 could scavenge free radicals, especially at very low concentration. In this system, exogenous CoQ 10 was more effective than α-tocopherol at the same concentration in scavenging free radicals. The molecular mechanism that leads to this activity is still unclear, but these results are of biochemical importance because they indicate that CoQ may act as an anti=oxidant in situations mimicking physiopathological conditions. This direct chemiluminescent method is promising for studies of biochemical processes which involve active oxygen species. (author). 24 refs.; 4 figs

  8. The efficacy of edaravone (radicut), a free radical scavenger, for cardiovascular disease.

    Science.gov (United States)

    Kikuchi, Kiyoshi; Tancharoen, Salunya; Takeshige, Nobuyuki; Yoshitomi, Munetake; Morioka, Motohiro; Murai, Yoshinaka; Tanaka, Eiichiro

    2013-07-04

    Edaravone was originally developed as a potent free radical scavenger, and has been widely used to treat acute ischemic stroke in Japan since 2001. Free radicals play an important role in the pathogenesis of a variety of diseases, such as cardiovascular diseases and stroke. Therefore, free radicals may be targets for therapeutic intervention in these diseases. Edaravone shows protective effects on ischemic insults and inflammation in the heart, vessel, and brain in experimental studies. As well as scavenging free radicals, edaravone has anti-apoptotic, anti-necrotic, and anti-cytokine effects in cardiovascular diseases and stroke. Edaravone has preventive effects on myocardial injury following ischemia and reperfusion in patients with acute myocardial infarction. Edaravone may represent a new therapeutic intervention for endothelial dysfunction in the setting of atherosclerosis, heart failure, diabetes, or hypertension, because these diseases result from oxidative stress and/or cytokine-induced apoptosis. This review evaluates the potential of edaravone for treatment of cardiovascular disease, and covers clinical and experimental studies conducted between 1984 and 2013. We propose that edaravone, which scavenges free radicals, may offer a novel option for treatment of cardiovascular diseases. However, additional clinical studies are necessary to verify the efficacy of edaravone.

  9. Edaravone, a potent free radical scavenger, reacts with peroxynitrite to produce predominantly 4-NO-edaravone.

    Science.gov (United States)

    Fujisawa, Akio; Yamamoto, Yorihiro

    2016-05-01

    3-Methyl-1-phenyl-2-pyrazolin-5-one (edaravone) is used in clinical treatment of acute brain infarction to rescue the penumbra, based on its ability to prevent lipid peroxidation by scavenging lipid peroxyl radicals. Here, we show that edaravone also reacts with peroxynitrite to yield 4-NO-edaravone as the major product and 4-NO2-edaravone as a minor product. We observed little formation of 3-methyl-1-phenyl-2-pyrazolin-4,5-dione (4-oxoedaravone) and its hydrate, 2-oxo-3-(phenylhydrazono)butanoic acid, which are the major free radical-induced oxidation products of edaravone, suggesting that free radicals are not involved in the reaction with peroxynitrite. The reaction of peroxynitrite with edaravone is approximately 30-fold greater than with uric acid, a physiological peroxynitrite scavenger (reaction rate k = 1.5 × 10 (4)  M(-1) s(-1) vs. 480 M(-1) s(-1)). These results suggest that edaravone functions therapeutically as a scavenger of peroxynitrite as well as lipid peroxyl radicals, which is consistent with a report that edaravone treatment reduced levels of 3-nitrotyrosine in the cerebrospinal fluid of patients with amyotrophic lateral sclerosis.

  10. The Efficacy of Edaravone (Radicut, a Free Radical Scavenger, for Cardiovascular Disease

    Directory of Open Access Journals (Sweden)

    Eiichiro Tanaka

    2013-07-01

    Full Text Available Edaravone was originally developed as a potent free radical scavenger, and has been widely used to treat acute ischemic stroke in Japan since 2001. Free radicals play an important role in the pathogenesis of a variety of diseases, such as cardiovascular diseases and stroke. Therefore, free radicals may be targets for therapeutic intervention in these diseases. Edaravone shows protective effects on ischemic insults and inflammation in the heart, vessel, and brain in experimental studies. As well as scavenging free radicals, edaravone has anti-apoptotic, anti-necrotic, and anti-cytokine effects in cardiovascular diseases and stroke. Edaravone has preventive effects on myocardial injury following ischemia and reperfusion in patients with acute myocardial infarction. Edaravone may represent a new therapeutic intervention for endothelial dysfunction in the setting of atherosclerosis, heart failure, diabetes, or hypertension, because these diseases result from oxidative stress and/or cytokine-induced apoptosis. This review evaluates the potential of edaravone for treatment of cardiovascular disease, and covers clinical and experimental studies conducted between 1984 and 2013. We propose that edaravone, which scavenges free radicals, may offer a novel option for treatment of cardiovascular diseases. However, additional clinical studies are necessary to verify the efficacy of edaravone.

  11. Hunger for iron: the alternative siderophore iron scavenging systems in highly virulent Yersinia.

    Directory of Open Access Journals (Sweden)

    Alexander eRakin

    2012-11-01

    Full Text Available Low molecular weight siderophores are used by many living organisms to scavenge scarcely available ferric iron. Presence of at least a single siderophore-based iron acquisition system is usually acknowledged as a virulence-associated trait and a prerequisite to become an efficient and successful pathogen. Currently it is assumed that yersiniabactin (Ybt is the solely functional endogenous siderophore iron uptake system in highly virulent Yersinia (Yersinia pestis, Y. pseudotuberculosis and Y. enterocolitica biotype 1B. Genes responsible for biosynthesis, transport and regulation of the yersiniabactin (ybt production are clustered on a mobile genetic element, the High Pathogenicity Island (HPI that is responsible for broad dissemination of the ybt genes in Enterobacteriaceae. However, the ybt gene cluster is absent from nearly half of Y. pseudotuberculosis O3 isolates and epidemic Y. pseudotuberculosis O1 isolates responsible for the Far East Scarlet-like Fever. Several potential siderophore-mediated iron uptake gene clusters are documented in Yersinia genomes, however neither of them have been proven to be functional. It has been suggested that at least two siderophores alternative to Ybt may operate in the highly virulent Yersinia pestis / Y. pseudotuberculosis group, and are referred to as pseudochelin (Pch and yersiniachelin (Ych. Furthermore, most sporadic Y. pseudotuberculosis O1 strains possess gene clusters encoding all three iron scavenging systems. Thus, the Ybt system appears not to be the sole endogenous siderophore iron uptake system in the highly virulent yersiniae and may be efficiently substituted and / or supplemented by alternative iron scavenging systems.

  12. Efficient Scavenging of Solar and Wind Energies in a Smart City.

    Science.gov (United States)

    Wang, Shuhua; Wang, Xue; Wang, Zhong Lin; Yang, Ya

    2016-06-28

    To realize the sustainable energy supply in a smart city, it is essential to maximize energy scavenging from the city environments for achieving the self-powered functions of some intelligent devices and sensors. Although the solar energy can be well harvested by using existing technologies, the large amounts of wasted wind energy in the city cannot be effectively utilized since conventional wind turbine generators can only be installed in remote areas due to their large volumes and safety issues. Here, we rationally design a hybridized nanogenerator, including a solar cell (SC) and a triboelectric nanogenerator (TENG), that can individually/simultaneously scavenge solar and wind energies, which can be extensively installed on the roofs of the city buildings. Under the same device area of about 120 mm × 22 mm, the SC can deliver a largest output power of about 8 mW, while the output power of the TENG can be up to 26 mW. Impedance matching between the SC and TENG has been achieved by using a transformer to decrease the impedance of the TENG. The hybridized nanogenerator has a larger output current and a better charging performance than that of the individual SC or TENG. This research presents a feasible approach to maximize solar and wind energies scavenging from the city environments with the aim to realize some self-powered functions in smart city.

  13. Glutathione as a radical scavenger and the biological consequences of thiyl radical production

    International Nuclear Information System (INIS)

    Winterbourn, C.C.

    1996-01-01

    A large number of compounds that have toxic effects can be metabolised to free radicals and secondary reactive oxygen species. These may be directly damaging or affect cell function by altering regulatory mechanisms through changing redox status. Protection is provided by an integrated system of antioxidant defenses. This includes reduced glutathione (GSH), one of the functions of which is as a free radical scavenger. For GSH to be an effective radical scavenging antioxidant, therefore, it must act in concert with superoxide dismutase to remove the superoxide so generated. Superoxide is produced in a variety of metabolic processes. It is also a secondary product of radicals reacting with oxygen either directly or through GSH. The biological reactivity of superoxide has been the subject of much debate ever since the discovery of superoxide dismutase in 1968. It has more recently become apparent that its rapid reaction with nitric oxide to give peroxynitrite, and its ability to reversibly oxidise and inactivate iron sulphur enzymes, contribute to the toxicity of superoxide. Another mechanism that could be important involves addition reactions of superoxide with other radicals to give organic peroxides. This reaction, to form a tyrosine peroxide, has come to authors attention through the study of the scavenging of tyrosyl radicals by GSH. It is also shown that a tyrosine peroxide is a major product of the oxidation of tyrosine by neutrophils

  14. Preparation of Egg White Liquid Hydrolysate (ELH) and Its Radical-Scavenging Activity

    Science.gov (United States)

    Noh, Dong Ouk; Suh, Hyung Joo

    2015-01-01

    In the present study, an optimum protease was selected to hydrolyze the egg white liquid protein for the antioxidant peptides. Alcalase treatment yielded the highest amount of α-amino groups (15.27 mg/mL), while the control (no enzymatic hydrolysis) showed the lowest amount of α-amino groups (1.53 mg/mL). Alcalase also gave the highest degree of hydrolysis (DH) value (43.2%) and was more efficient for egg white liquid hydrolysis than the other enzymes. The Alcalase hydrolysate had the highest radical-scavenging activity (82.5%) at a concentration of 5.0 mg/mL. The conditions for enzymatic hydrolysis of egg white liquid with Alcalase were selected as substrate : water ratio of 2:1. Five percent Alacalse treatment did not show significant (P>0.05) increases of DH and α-amino nitrogen content after 24 h-hydrolysis. Thirty two hour-hydrolysis with 5% Alcalase is sufficient to make antioxidative egg white liquid hydrolysate from egg white liquid. DPPH and ABTS radical-scavenging activities were significantly (P<0.05) higher after enzymatic digestion. These results suggest that active peptides released from egg-white protein are effective radical-scavengers. Thus, this approach may be useful for the preparation of potent antioxidant products. PMID:26451355

  15. Evaluation of Radical Scavenging Activity of Sempervivum tectorum and Corylus avellana Extracts with Different Phenolic Composition.

    Science.gov (United States)

    Alberti, Ágnes; Riethmüller, Eszter; Béni, Szabolcs; Kéry, Ágnes

    2016-04-01

    Semnpervivum tectorum L. and Corylus avellana L. are traditional herbal remedies exhibiting antioxidant activity and representing diverse phenolic composition. The aim of this study was to reveal the contribution of certain compounds to total radical scavenging activity by studying S. tectorum and C. avellana extracts prepared with solvents of different selectivity for diverse classes of phenolics. Antioxidant activity of S. tectorum and C. avellana samples was determined in the ABTS and DPPH radical scavenging assays, and phenolic composition was evaluated by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). Correlations between antioxidant activity and phenolic content of houseleek extracts have been revealed. Significant differences regarding antioxidant activity have been shown between S. tectorum 80% (v/v) methanol extract and its fractions. Additionally, synergism among the constituents present together in the whole extract was assumed. Significantly higher radical scavenging activity of hazel extracts has been attributed to the differences in phenolic composition compared with houseleek extracts.

  16. Comparison of taurine, GABA, Glu, and Asp as scavengers of malondialdehyde in vitro and in vivo

    Science.gov (United States)

    Deng, Yan; Wang, Wei; Yu, Pingfeng; Xi, Zhijiang; Xu, Lijian; Li, Xiaolong; He, Nongyue

    2013-04-01

    The purpose of this study is to determine if amino acid neurotransmitters such as gamma-aminobutyric acid (GABA), taurine, glutamate (Glu), and aspartate (Asp) can scavenge activated carbonyl toxicants. In vitro, direct reaction between malondialdehyde (MDA) and amino acids was researched using different analytical methods. The results indicated that scavenging activated carbonyl function of taurine and GABA is very strong and that of Glu and Asp is very weak in pathophysiological situations. The results provided perspective into the reaction mechanism of taurine and GABA as targets of activated carbonyl such as MDA in protecting nerve terminals. In vivo, we studied the effect of taurine and GABA as antioxidants by detecting MDA concentration and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities. It was shown that MDA concentration was decreased significantly, and the activities of SOD and GSH-Px were increased significantly in the cerebral cortex and hippocampus of acute epileptic state rats, after the administration of taurine and GABA. The results indicated that the peripherally administered taurine and GABA can scavenge free radicals and protect the tissue against activated carbonyl in vivo and in vitro.

  17. Extracts, Anthocyanins and Procyanidins from Aronia melanocarpa as Radical Scavengers and Enzyme Inhibitors

    Directory of Open Access Journals (Sweden)

    Hilde Barsett

    2013-03-01

    Full Text Available Extracts, subfractions, isolated anthocyanins and isolated procyanidins B2, B5 and C1 from the berries and bark of Aronia melanocarpa were investigated for their antioxidant and enzyme inhibitory activities. Four different bioassays were used, namely scavenging of the diphenylpicrylhydrazyl (DPPH radical, inhibition of 15-lipoxygenase (15-LO, inhibition of xanthine oxidase (XO and inhibition of α-glucosidase. Among the anthocyanins, cyanidin 3-arabinoside possessed the strongest and cyanidin 3-xyloside the weakest radical scavenging and enzyme inhibitory activity. These effects seem to be influenced by the sugar units linked to the anthocyanidin. Subfractions enriched in procyanidins were found to be potent α-glucosidase inhibitors; they possessed high radical scavenging properties, strong inhibitory activity towards 15-LO and moderate inhibitory activity towards XO. Trimeric procyanidin C1 showed higher activity in the biological assays compared to the dimeric procyanidins B2 and B5. This study suggests that different polyphenolic compounds of A. melanocarpa can have beneficial effects in reducing blood glucose levels due to inhibition of α-glucosidase and may have a potential to alleviate oxidative stress.

  18. Free radical scavengers and antioxidants from Lemongrass (Cymbopogon citratus (DC.) Stapf.).

    Science.gov (United States)

    Cheel, José; Theoduloz, Cristina; Rodríguez, Jaime; Schmeda-Hirschmann, Guillermo

    2005-04-06

    Methanol, MeOH/water extracts, infusion, and decoction of Cymbopogon citratus were assessed for free radical scavenging effects measured by the bleaching of the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical, scavenging of the superoxide anion, and inhibition of the enzyme xanthine oxidase (XO) and lipid peroxidation in human erythrocytes. The extracts presented effect in the DPPH and superoxide anion assay, with values ranging between 40 and 68% and 15-32% at 33 and 50 microg/mL, respectively, inhibited lipid peroxidation in erythrocytes by 19-71% at 500 microg/mL and were inactive toward the XO at 50 microg/mL. Isoorientin, isoscoparin, swertiajaponin, isoorientin 2' '-O-rhamnoside, orientin, chlorogenic acid, and caffeic acid were isolated and identified by spectroscopic methods. Isoorientin and orientin presented similar activities toward the DPPH (IC(50): 9-10 microM) and inhibited lipid peroxidation by 70% at 100 microg/mL. Caffeic and chlorogenic acid were active superoxide anion scavengers with IC(50) values of 68.8 and 54.2 microM, respectively, and a strong effect toward DPPH. Caffeic acid inhibited lipid peroxidation by 85% at 100 microg/mL.

  19. 2,4,6-Trichlorophenylhydrazine Schiff bases as DPPH radical and super oxide anion scavengers.

    Science.gov (United States)

    Khan, Khalid Mohammed; Shah, Zarbad; Ahmad, Viqar Uddin; Khan, Momin; Taha, Muhammad; Rahim, Fazal; Ali, Sajjad; Ambreen, Nida; Perveen, Shahnaz; Choudhary, M Iqbal; Voelter, Wolfgang

    2012-05-01

    Syntheses of thirty 2,4,6-trichlorophenylhydrazine Schiff bases 1-30 were carried out and evaluated for their in vitro DPPH radical and super oxide anion scavenging activities. Compounds 1-30 have shown a varying degree of DPPH radical scavenging activity and their IC50 values range between 4.05-369.30 µM. The compounds 17, 28, 18, 14, 8, 15, 12, 2, 29, and 7 exhibited IC50 values ranging between 4.05±0.06-24.42±0.86 µM which are superior to standard n-propylgallate (IC50=30.12±0.27 µM). Selected compounds have shown a varying degree of superoxide anion radical scavenger activity and their IC50 values range between 91.23-406.90 µM. The compounds 28, 8, 17, 15, and 14, showed IC50 values between 91.23±1.2-105.31±2.29 µM which are superior to standard n-propylgallate (IC50=106.34±1.6 µM).

  20. An experimental evaluation of potential scavenger effects on snake road mortality detections

    Science.gov (United States)

    Hubbard, Kaylan A.; Chalfoun, Anna D.

    2012-01-01

    As road networks expand and collisions between vehicles and wildlife become more common, accurately quantifying mortality rates for the taxa that are most impacted will be critical. Snakes are especially vulnerable to collisions with vehicles because of their physiology and behavior. Reptile road mortality is typically quantified using driving or walking surveys; however, scavengers can rapidly remove carcasses from the road and cause underestimation of mortality. Our objective was to determine the effect that scavengers might have had on our ability to accurately detect reptile road mortality during over 150 h and 4,000 km of driving surveys through arid shrublands in southwest Wyoming, which resulted in only two observations of mortality. We developed unique simulated snake carcasses out of Burbot (Lota lota), a locally invasive fish species, and examined removal rates across three different road types at three study sites. Carcass size was not a significant predictor of time of removal, and carcass removal was comparable during the daytime and nighttime hours. However, removal of simulated carcasses was higher on paved roads than unpaved or two-track roads at all study sites, with an average of 75% of the carcasses missing within 60 h compared to 34% and 31%, respectively. Scavengers may therefore negatively impact the ability of researchers to accurately detect herpetofaunal road mortality, especially for paved roads where road mortality is likely the most prevalent.

  1. Competence building capacity shortage

    International Nuclear Information System (INIS)

    Doorman, Gerard; Wangensteen, Ivar; Bakken, Bjoern

    2005-02-01

    The objective of the project 'Competence Building Capacity Shortage' has been 'to increase knowledge about central approaches aimed at solving the peaking capacity problem in restructured power systems'. With respect to reserve markets, a model was developed in the project to analyze the relations between reserve requirements and prices in the spot and reserve markets respectively. A mathematical model was also developed and implemented, which also includes the balance market, and has a good ability to predict the relations between these markets under various assumptions. With some further development, this model can be used fore realistic analyses of these markets in a Nordic context. It was also concluded that certain system requirements with respect to frequency and time deviation can be relaxed without adverse effects. However, the requirements to system bias, Frequency Activated Operating Reserves and Frequency Activated Contingency Reserves cannot be relaxed, the latter because they must cover the dimensioning fault in the system. On the other hand, Fast Contingency Reserves can be reduced by removing requirements to national balances. Costs can furthermore be reduced by increasingly adapting a Nordic as opposed to national approach. A model for stepwise power flow was developed in the project, which is especially useful to analyze slow power system dynamics. This is relevant when analysing the effects of reserve requirements. A model for the analysis of the capacity balance in Norway and Sweden was also developed. This model is useful for looking at the future balance under various assumptions regarding e.g. weather conditions, demand growth and the development of the generation system. With respect to the present situation, if there is some price flexibility on the demand side and system operators are able to use reserves from the demand side, the probability for load shedding during the peak load hour is close to zero under the weather conditions after

  2. Polyphenolic content and antioxidant capacity of white, green, black, and herbal teas: a kinetic study

    Directory of Open Access Journals (Sweden)

    Shannon, E.,

    2017-08-01

    Full Text Available Camellia sinensis teas, and tisanes derived from herbs or fruit, are rich in polyphenolic, antioxidant compounds. This study compared the total phenolic content (TPC, total flavonoid content (TFC, ferric reducing antioxidant power (FRAP, DPPH radical scavenging capacity, and caffeine content of teas (black, green, white, chamomile, and mixed berry/hibiscus over a range of infusion times (0.5–10 mins at 90°C. Green, followed by black tea, respectively, had the greatest TPC (557.58 and 499.19μg GAE/g, TFC (367.84 and 325.18μg QE/g, FRAP (887.38 and 209.38μg TE/g, and DPPH radical scavenging capacity (1233.03 and 866.39μg AAE/g. Caffeine content per cup (200mL in black, green, and white tea was 63, 51, and 49mg respectively. Changes in the phenolic content and antioxidant capacity of teas were modelled using zero, first, and fractional-conversion-first-order (FCFO kinetic models. Results fitted a FCFO kinetic model, providing useful data for maximum phytochemical preservation in the optimisation of industrial and domestic processing. As a dietary comparison, green, black, and white tea were found to have a greater phenolic content and antioxidant capacity than fresh orange and apple juice. It can be concluded that green and black teas are significant sources of dietary phenolic antioxidants.

  3. Principled Scavenging

    National Research Council Canada - National Science Library

    Monnier, Stefan; Saha, Bratin; Shao, Zhong

    2000-01-01

    .... Unfortunately, these systems cannot get rid of the dependency on a trusted garbage collector. Indeed, constructing a provably type-safe garbage collector is one of the major open problems in the area of certifying compilation...

  4. Expression of scavenger receptor‐AI promotes alternative activation of murine macrophages to limit hepatic inflammation and fibrosis

    Science.gov (United States)

    Labonte, Adam C.; Sung, Sun‐Sang J.; Jennelle, Lucas T.; Dandekar, Aditya P.

    2016-01-01

    The liver maintains an immunologically tolerant environment as a result of continuous exposure to food and bacterial constituents from the digestive tract. Hepatotropic pathogens can take advantage of this niche and establish lifelong chronic infections causing hepatic fibrosis and hepatocellular carcinoma. Macrophages (Mϕ) play a critical role in regulation of immune responses to hepatic infection and regeneration of tissue. However, the factors crucial for Mϕ in limiting hepatic inflammation or resolving liver damage have not been fully understood. In this report, we demonstrate that expression of C‐type lectin receptor scavenger receptor‐AI (SR‐AI) is crucial for promoting M2‐like Mϕ activation and polarization during hepatic inflammation. Liver Mϕ uniquely up‐regulated SR‐AI during hepatotropic viral infection and displayed increased expression of alternative Mϕ activation markers, such as YM‐1, arginase‐1, and interleukin‐10 by activation of mer receptor tyrosine kinase associated with inhibition of mammalian target of rapamycin. Expression of these molecules was reduced on Mϕ obtained from livers of infected mice deficient for the gene encoding SR‐AI (msr1). Furthermore, in vitro studies using an SR‐AI‐deficient Mϕ cell line revealed impeded M2 polarization and decreased phagocytic capacity. Direct stimulation with virus was sufficient to activate M2 gene expression in the wild‐type (WT) cell line, but not in the knockdown cell line. Importantly, tissue damage and fibrosis were exacerbated in SR‐AI–/– mice following hepatic infection and adoptive transfer of WT bone‐marrow–derived Mϕ conferred protection against fibrosis in these mice. Conclusion: SR‐AI expression on liver Mϕ promotes recovery from infection‐induced tissue damage by mediating a switch to a proresolving Mϕ polarization state. (Hepatology 2017;65:32‐43). PMID:27770558

  5. Determination of Free Radical Scavenging, Antioxidative DNA Damage Activities and Phytochemical Components of Active Fractions from Lansium domesticum Corr. Fruit

    Science.gov (United States)

    Klungsupya, Prapaipat; Suthepakul, Nava; Muangman, Thanchanok; Rerk-Am, Ubon; Thongdon-A, Jeerayu

    2015-01-01

    Lansium domesticum Corr. or “long-kong” is one of the most popular fruits in Thailand. Its peel (skin, SK) and seeds (SD) become waste unless recycled or applied for use. This study was undertaken to determine the bioactivity and phytochemical components of L. domesticum (LD) skin and seed extracts. Following various extraction and fractionation procedures, 12 fractions were obtained. All fractions were tested for antioxidant capacity against O2−• and OH•. It was found that the peel of L. domesticum fruits exhibited higher O2−• and OH• scavenging activity than seeds. High potential antioxidant activity was found in two fractions of 50% ethanol extract of peel followed by ethyl acetate (EA) fractionation (LDSK50-EA) and its aqueous phase (LDSK50-H2O). Therefore, these two active fractions were selected for further studies on their antioxidative activity against DNA damage by hydrogen peroxide (H2O2) in human TK6 cells using comet assay. The comet results revealed DNA-protective activity of both LDSK50-EA and LDSK50-H2O fractions when TK6 human lymphoblast cells were pre-treated at 25, 50, 100, and 200 μg/mL for 24 h prior to H2O2 exposure. The phytochemical analysis illustrated the presence of phenolic substances, mainly scopoletin, rutin, and chlorogenic acid, in these two active fractions. This study generates new information on the biological activity of L. domesticum. It will promote and strengthen the utilization of L. domesticum by-products. PMID:26287238

  6. Determination of Free Radical Scavenging, Antioxidative DNA Damage Activities and Phytochemical Components of Active Fractions from Lansium domesticum Corr. Fruit

    Directory of Open Access Journals (Sweden)

    Prapaipat Klungsupya

    2015-08-01

    Full Text Available Lansium domesticum Corr. or “long-kong” is one of the most popular fruits in Thailand. Its peel (skin, SK and seeds (SD become waste unless recycled or applied for use. This study was undertaken to determine the bioactivity and phytochemical components of L. domesticum (LD skin and seed extracts. Following various extraction and fractionation procedures, 12 fractions were obtained. All fractions were tested for antioxidant capacity against O2−• and OH•. It was found that the peel of L. domesticum fruits exhibited higher O2−• and OH• scavenging activity than seeds. High potential antioxidant activity was found in two fractions of 50% ethanol extract of peel followed by ethyl acetate (EA fractionation (LDSK50-EA and its aqueous phase (LDSK50-H2O. Therefore, these two active fractions were selected for further studies on their antioxidative activity against DNA damage by hydrogen peroxide (H2O2 in human TK6 cells using comet assay. The comet results revealed DNA-protective activity of both LDSK50-EA and LDSK50-H2O fractions when TK6 human lymphoblast cells were pre-treated at 25, 50, 100, and 200 μg/mL for 24 h prior to H2O2 exposure. The phytochemical analysis illustrated the presence of phenolic substances, mainly scopoletin, rutin, and chlorogenic acid, in these two active fractions. This study generates new information on the biological activity of L. domesticum. It will promote and strengthen the utilization of L. domesticum by-products.

  7. Radical scavenging, prolyl endopeptidase inhibitory, and antimicrobial potential of a cultured Himalayan lichen Cetrelia olivetorum.

    Science.gov (United States)

    Savale, Swapnil Anil; Pol, Chaitrali Satish; Khare, Roshni; Verma, Neeraj; Gaikwad, Subhash; Mandal, Bapi; Behera, Bhaskar C

    2016-01-01

    Lichens are source of natural bioactive compounds which are traditionally used to cure a variety of ailments. The objective of this study is to assess free radical scavenging, prolyl endopeptidase inhibitory (PEPI), and antimicrobial potential of a high altitude lichen species Cetrelia olivetorum (Nyl.) W. L. Culb. & C. F. Culb (Parmeliaceae). Lichen C. olivetorum has been cultured in vitro, and optimized culture conditions were implemented in bioreactor to obtain high quantity of biomass for the study of radical scavenging, PEPI, and antimicrobial activities. Radical scavenging activity of methanol extract of Cetrelia olivetorum (MECO) was tested at 100 µg/mL, PEPI activity at 25 and 50 µg/mL, and antimicrobial activity at 5, 25, 50, and 100 µg/mL conc. All the biological activities of natural thallus extract and its derived culture extract were evaluated spectrophotometrically. Murashige and Skoog medium supplemented with 3% glucose and 100 ppb indole-3-butyric acid (IBA) supported biomass growth at flask level and yielded 5.095 g biomass in bioreactor. MECO of both the cultured and the natural lichen exhibited half inhibiting concentration (IC50) for radical scavenging activities in the range of 50-60 µg/mL, whereas the IC50 value of standard antioxidants was found to be in the range of 12-29 µg/mL. The IC50 value of lichen extract for PEPI activity was 144-288 µg/mL, whereas the IC50 value of standard prolyl endopeptidase inhibitor, Z-pro-prolinal, was 57.73 µg/mL. As far as the antimicrobial activity of MECO is concerned, minimum inhibitory concentration (MIC) value of lichen extracts against tested microorganisms was obtained in the range of 50-104 µg/mL and found to be more effective than commercially available standard erythromycin. Murashige and Skoog medium containing IBA was found to be suitable for maximum biomass production of C. olivetorum under bioreactor conditions. The cultured lichen biomass extract also showed

  8. Hydroxyl radical-scavenging property of secoisolariciresinol diglucoside (SDG) isolated from flax-seed.

    Science.gov (United States)

    Prasad, K

    1997-03-01

    Recently there has been a moderate resurgence in the use of flax-seed in a variety of ways including bread. The scientific basis of its use is very limited. There is some claim for beneficial effects in cancer and lupus nephritis. These claims could be due to its ability to scavenge oxygen radicals. However, its antioxidant activity is not known. Recently a method has been developed to isolate secoisolariciresinol diglucoside (SDG) from defatted flax-seed in large quantity (patent pending). We investigated the ability of SDG to scavenge .OH using high pressure liquid chromatography (HPLC) method. .OH was generated by photolysis of H2O2 (1.25-10.0 mumoles/ml) with ultraviolet light and was trapped with salicylic acid which is hydroxylated to produce .OH-adduct products 2,3-dihydroxybenzoic acid (DHBA) and 2,5-DHBA. H2O2 produced a concentration-dependent .OH as estimated by 2,3-DHBA and 2,5-DHBA. A standard curve was constructed for known concentrations of 2,3-DHBA and 2,5-DHBA against corresponding area under the peaks which then was used for measurement of 2,3-DHBA and 2,5-DHBA generated by UV irradiation of H2O2 in the presence of salicylic acid. SDG in the concentration range of 25, 50, 100, 250, 500, 750, 1000 and 2000 micrograms/ml (36.4, 72.8, 145.6, 364.0, 728.0, 1092.0, 1456.0 and 2912.0 microM respectively) produced a concentration-dependent decrease in the formation of 2,3-DHBA and 2,5-DHBA, the inhibition being 4 and 4.65% respectively with 25 micrograms/ml (36.4 microM) and 82 and 74% respectively with 2000 micrograms/ml (2912.0 microM). The decrease in .OH-adduct products was due to scavenging of .OH and not by scavenging of formed 2,3-DHBA and 2,5-DHBA. SDG prevented the lipid peroxidation of liver homogenate in a concentration-dependent manner in the concentration range from 319.3-2554.4 microM. These results suggest that SDG scavenges .OH and therefore has an antioxidant activity.

  9. Extracellular hemoglobin polarizes the macrophage proteome toward Hb-clearance, enhanced antioxidant capacity and suppressed HLA class 2 expression.

    OpenAIRE

    Kaempfer Theresa; Duerst Elena; Gehrig Peter; Roschitzki Bernd; Rutishauser Dorothea; Grossmann Jonas; Schoedon Gabriele; Vallelian Florence; Schaer Dominik J

    2011-01-01

    Peripheral blood monocytes and macrophages are the only cell population with a proven hemoglobin (Hb) clearance capacity through the CD163 scavenger receptor pathway. Hb detoxification and related adaptive cellular responses are assumed to be essential processes to maintaining tissue homeostasis and promoting wound healing in injured tissues. Using a dual platform mass spectrometry analysis with MALDI TOF/TOF and LTQ Orbitrap instruments combined with isobaric tag for relative and absolute qu...

  10. Novel Water Soluble Chitosan Derivatives with 1,2,3-Triazolium and Their Free Radical-Scavenging Activity.

    Science.gov (United States)

    Li, Qing; Sun, Xueqi; Gu, Guodong; Guo, Zhanyong

    2018-03-28

    Chitosan is an abundant and renewable polysaccharide, which exhibits attractive bioactivities and natural properties. Improvement such as chemical modification of chitosan is often performed for its potential of providing high bioactivity and good water solubility. A new class of chitosan derivatives possessing 1,2,3-triazolium charged units by associating "click reaction" with efficient 1,2,3-triazole quaternization were designed and synthesized. Their free radical-scavenging activity against three free radicals was tested. The inhibitory property and water solubility of the synthesized chitosan derivatives exhibited a remarkable improvement over chitosan. It is hypothesized that triazole or triazolium groups enable the synthesized chitosan to possess obviously better radical-scavenging activity. Moreover, the scavenging activity against superoxide radical of chitosan derivatives with triazolium (IC 50 radical-scavenging assay, the same pattern were observed, which should be related to the triazolium grafted at the periphery of molecular chains.

  11. Evaluation of Free Radical Scavenging Activity in Ethanolic Extract from Promising Accessions of Curcuma aeruginosa RoxB.

    Directory of Open Access Journals (Sweden)

    Waras Nurcholis

    2017-11-01

    Full Text Available This study evaluated the free radical scavenging activity in ethanolic extracts from 20 accessions of Curcuma aeruginosa. The radical scavenging activity of the extract accessions was investigated with 2,2-diphenyl-1-picrylhydrazyl (DPPH radical. IC50 values for DPPH radical scavenging activity ranged from 89.81 to 505.65 µg mL-1. Based on IC50 values, twenty accessions of C. aeruginosa can be divided into three groups: strong (two accessions; moderate (seventeen accessions; and low (one accession of DPPH scavenger. Sukoharjo (SH and Muara Bungo (MB showed promising accessions for antioxidant potential, thus these accessions important to selection for future breeding program in pharmaceutical products.

  12. The effect of pressure and temperature on aluminium hydrolysis: Implications to trace metal scavenging in natural waters

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.

    Removal of aluminium through precipitation/scavenging in natural waters was evaluated based on its hydrolysis at different temperatures and pressures. In general, pH for the occurrence of cation hydrolysis was lowered with hike in temperature which...

  13. 1992 Annual Capacity Report

    International Nuclear Information System (INIS)

    1993-05-01

    The Standard Contract for Disposal of Spent Nuclear Fuel and/or High-Level Radioactive Waste (10 CFR Part 961) requires the Department of Energy (DOE) to issue an Annual Capacity Report (ACR) for planning purposes. This report is the fifth in the series published by DOE. In May 1993, DOE published the 1992 Acceptance Priority Ranking (APR) that established the order in which DOE will allocate projected acceptance capacity. As required by the Standard Contract, the acceptance priority ranking is based on the date the spent nuclear fuel (SNF) was permanently discharged, with the owners of the oldest SNF, on an industry-wide basis, given the highest priority. The 1992 ACR applies the projected waste acceptance rates in Table 2.1 to the 1992 APR, resulting in individual allocations for the owners and generators of the SNF. These allocations are listed in detail in the Appendix, and summarized in Table 3.1. The projected waste acceptance rates for SNF presented in Table 2.1 are nominal and assume a site for a Monitored Retrievable Storage (MRS) facility will be obtained; the facility will initiate operations in 1998; and the statutory linkages between the MRS facility and the repository set forth in the Nuclear Waste Policy Act of 1982, as amended (NWPA), will be modified. During the first ten years following projected commencement of Civilian Radioactive Waste Management System (CRWMS) operation, the total quantity of SNF that could be accepted is projected to be 8,200 metric tons of uranium (MTU). This is consistent with the storage capacity licensing conditions imposed on an MRS facility by the NWPA. The annual acceptance rates provide an approximation of the system throughput and are subject to change as the program progresses

  14. Quantum reading capacity

    International Nuclear Information System (INIS)

    Pirandola, Stefano; Braunstein, Samuel L; Lupo, Cosmo; Mancini, Stefano; Giovannetti, Vittorio

    2011-01-01

    The readout of a classical memory can be modelled as a problem of quantum channel discrimination, where a decoder retrieves information by distinguishing the different quantum channels encoded in each cell of the memory (Pirandola 2011 Phys. Rev. Lett. 106 090504). In the case of optical memories, such as CDs and DVDs, this discrimination involves lossy bosonic channels and can be remarkably boosted by the use of nonclassical light (quantum reading). Here we generalize these concepts by extending the model of memory from single-cell to multi-cell encoding. In general, information is stored in a block of cells by using a channel-codeword, i.e. a sequence of channels chosen according to a classical code. Correspondingly, the readout of data is realized by a process of ‘parallel’ channel discrimination, where the entire block of cells is probed simultaneously and decoded via an optimal collective measurement. In the limit of a large block we define the quantum reading capacity of the memory, quantifying the maximum number of readable bits per cell. This notion of capacity is nontrivial when we suitably constrain the physical resources of the decoder. For optical memories (encoding bosonic channels), such a constraint is energetic and corresponds to fixing the mean total number of photons per cell. In this case, we are able to prove a separation between the quantum reading capacity and the maximum information rate achievable by classical transmitters, i.e. arbitrary classical mixtures of coherent states. In fact, we can easily construct nonclassical transmitters that are able to outperform any classical transmitter, thus showing that the advantages of quantum reading persist in the optimal multi-cell scenario. (paper)

  15. Capacity at Railway Stations

    DEFF Research Database (Denmark)

    Landex, Alex

    2011-01-01

    zone(s) the possible conflicts with other trains (also in the opposite direction) are taken into account leading to more trustworthy results. Although the UIC 406 methodology proposes that the railway network should be divided into line sections when trains turn around and when the train order...... is changed, this paper recommends that the railway lines are not always be divided. In case trains turn around on open (single track) line, the capacity consumption may be too low if a railway line is divided. The same can be the case if only few trains are overtaken at an overtaking station. For dead end...

  16. Structure dependent antioxidant capacity of phlorotannins from Icelandic Fucus vesiculosus by UHPLC-DAD-ECD-QTOFMS.

    Science.gov (United States)

    Hermund, Ditte B; Plaza, Merichel; Turner, Charlotta; Jónsdóttir, Rosa; Kristinsson, Hordur G; Jacobsen, Charlotte; Nielsen, Kristian Fog

    2018-02-01

    Brown algae are rich in polyphenolic compounds, phlorotannins, which have been found to possess high in vitro antioxidant capacity, especially DPPH radical scavenging activity, due to the high number of hydroxyl groups. Whereas, the overall antioxidant capacity of brown algae extracts has been widely studied, the antioxidant capacity of individual phlorotannins has been rarely explored. The aim of this study was to determine the structure dependant antioxidant capacity of phlorotannins from Icelandic brown algae, Fucus vesiculosus. The antioxidant capacity of individual phlorotannins was determined by an on-line method using liquid chromatography and an electrochemical detector followed by quadrupole Time of Flight mass spectrometry (UHPLC-DAD-ECD-QTOFMS). Tentative structural elucidation of 13 phlorotannin isomers from EAF was obtained by LC-DAD-QTOFMS, ranging from 374 to 870Da. On-line determination of antioxidant capacity of the individual phlorotannins generally showed that low molecular phlorotannins exhibited higher antioxidant capacity and that the capacity decreased with polymerisation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Applying Knowledge of Species-Typical Scavenging Behavior to the Search and Recovery of Mammalian Skeletal Remains.

    Science.gov (United States)

    Young, Alexandria; Stillman, Richard; Smith, Martin J; Korstjens, Amanda H

    2016-03-01

    Forensic investigations involving animal scavenging of human remains require a physical search of the scene and surrounding areas. However, there is currently no standard procedure in the U.K. for physical searches of scavenged human remains. The Winthrop and grid search methods used by police specialist searchers for scavenged remains were examined through the use of mock red fox (Vulpes vulpes) scatter scenes. Forty-two police specialist searchers from two different regions within the U.K. were divided between those briefed and not briefed with fox-typical scavenging information. Briefing searchers with scavenging information significantly affected the recovery of scattered bones (χ(2) = 11.45, df = 1, p = 0.001). Searchers briefed with scavenging information were 2.05 times more likely to recover bones. Adaptions to search methods used by searchers were evident on a regional level, such that searchers more accustom to a peri-urban to rural region recovered a higher percentage of scattered bones (58.33%, n = 84). © 2015 American Academy of Forensic Sciences.

  18. Smooth Interfacial Scavenging for Resistive Switching Oxide via the Formation of Highly Uniform Layers of Amorphous TaOx.

    Science.gov (United States)

    Tsurumaki-Fukuchi, Atsushi; Nakagawa, Ryosuke; Arita, Masashi; Takahashi, Yasuo

    2018-02-14

    We demonstrate that the inclusion of a Ta interfacial layer is a remarkably effective strategy for forming interfacial oxygen defects at metal/oxide junctions. The insertion of an interfacial layer of a reactive metal, that is, a "scavenging" layer, has been recently proposed as a way to create a high concentration of oxygen defects at an interface in redox-based resistive switching devices, and growing interest has been given to the underlying mechanism. Through structural and chemical analyses of Pt/metal/SrTiO 3 /Pt structures, we reveal that the rate and amount of oxygen scavenging are not directly determined by the formation free energies in the oxidation reactions of the scavenging metal and unveil the important roles of oxygen diffusibility. Active oxygen scavenging and highly uniform oxidation via scavenging are revealed for a Ta interfacial layer with high oxygen diffusibility. In addition, the Ta scavenging layer is shown to exhibit a highly uniform structure and to form a very flat interface with SrTiO 3 , which are advantageous for the fabrication of a steep metal/oxide contact.

  19. Health risk reduction behaviors model for scavengers exposed to solid waste in municipal dump sites in Nakhon Ratchasima Province, Thailand

    Directory of Open Access Journals (Sweden)

    Thirarattanasunthon P

    2012-08-01

    Full Text Available Phiman Thirarattanasunthon,1 Wattasit Siriwong,1,2 Mark Robson,2–4 Marija Borjan3 1College of Public Health Sciences, Chulalongkorn University, 2Thai Fogarty ITREOH Center, Chulalongkorn University, Bangkok, Thailand; 3School of Environmental and Biological Sciences, Rutgers University, New Brunswick, 4UMDNJ-School of Public Health, Piscataway, NJ, USAAbstract: The aim of this study was to evaluate the effect of comprehensive health risk protection behaviors, knowledge, attitudes, and practices among scavengers in open dump sites. A control group of 44 scavengers and an intervention group of 44 scavengers participated in this study. Interventions included the use of personal protective equipment, health protection training, and other measures. The analysis showed significant differences before and after the intervention program and also between the control and intervention groups. These observations suggest that further action should be taken to reduce adverse exposure during waste collection. To reduce health hazards to workers, dump site scavenging should be incorporated into the formal sector program. Solid waste and the management of municipal solid waste has become a human and environmental health issue and future research should look at constructing a sustainable model to help protect the health of scavengers and drive authorities to adopt safer management techniques.Keywords: scavenger, health risk reduction behaviors model (HRRBM, personal protective equipment (PPE, knowledge, attitude, and practice (KAP, waste health coordinator (WHC

  20. Deficiency of employability capacity

    Directory of Open Access Journals (Sweden)

    Pelse I.

    2012-10-01

    Full Text Available Young unemployed people have comprised one of the significantly largest groups of the unemployed people in Latvia in recent years. One of the reasons why young people have difficulty integrating into the labour market is the “expectation gap” that exists in the relations between employers and the new generation of workers. Employers focus on capacity-building for employability such individual factors as strength, patience, self-discipline, self-reliance, self-motivation, etc., which having a nature of habit and are developed in a long-term work socialization process, which begins even before the formal education and will continue throughout the life cycle. However, when the socialization is lost, these habits are depreciated faster than they can be restored. Currently a new generation is entering the labour market, which is missing the succession of work socialization. Factors, such as rising unemployment and poverty in the background over the past twenty years in Latvia have created a very unfavourable employability background of “personal circumstances” and “external factors”, which seriously have impaired formation of the skills and attitudes in a real work environment. The study reveals another paradox – the paradox of poverty. Common sense would want to argue that poverty can be overcome by the job. However, the real state of affairs shows that unfavourable coincidence of the individual, personal circumstances and external factors leads to deficit of employability capacity and possibility of marked social and employment deprivation.