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Sample records for european female silver

  1. Swimming suppresses hepatic vitellogenesis in European female silver eels as shown by expression of the estrogen receptor 1, vitellogenin1 and vitellogenin2 in the liver

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    Nieveen Maaike C

    2010-03-01

    Full Text Available Abstract Background When European silver eels (Anguilla anguilla venture into the Atlantic Ocean for their 6,000 km semelparous spawning run to the Sargasso Sea, they are still in a prepubertal stage. Further sexual development appears to be blocked by dopaminergic inhibition of hypothalamus and pituitary activity. Recently, we found that swimming for several weeks in freshwater stimulated the incorporation of fat droplets in the oocytes. So, it was hypothesized that long term swimming in seawater would release the inhibition further and would also stimulate the production of vitellogenin by the liver. Methods For this study a swim-flume was constructed to allow simulated migration of migratory female silver eels for 3 months (1,420 km in natural seawater at 20 degrees C. Primers were designed for polymerase chain reactions to measure the mRNA expression of estrogen receptor 1 (esr1, vitellogenin1 (vtg1 and vitellogenin2 (vtg2 genes in the liver of European female silver eels. Results In comparison to resting eels, swimming eels showed a diminished expression of esr1, vtg1 and vtg2 in the liver. They also had lower plasma calcium (Ca; indicative of vitellogenin levels in their blood. This showed that vitellogenesis is more strongly suppressed in swimming than in resting eels. However, when eels were subsequently stimulated by 3 weekly carp pituitary extract injections, the expression of the same genes and plasma levels of Ca strongly increased in both groups to similar levels, thus equalizing the initial differences between resting and swimming. Conclusions It is concluded that vitellogenesis remains suppressed during resting and even more during swimming. The fact that swimming stimulates fat deposition in the oocytes but suppresses vitellogenesis indicates that these events are separated in nature and occur sequentially. Swimming-suppressed vitellogenesis may imply that in nature eels undergo vitellogenesis and final maturation near or at the

  2. Reproductive potential of silver European eels (Anguilla anguilla migrating from Vistonis Lake (Northern Aegean Sea, Greece

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    R. MACNAMARA

    2014-06-01

    Full Text Available The European eel (Anguilla anguilla, once abundant throughout much of Europe and North Africa, has recently been classified as critically endangered. Information on its biology from the eastern Mediterranean is lacking, especially in relation to spawner quality. Therefore, silver eels were sampled during their seaward spawning migration from Vistonis Lake in Greece. Characteristics linked to reproductive output and success (i.e. body size and condition, sex ratio, silvering, Anguillicola crassus infection, fecundity and oocyte diameter were examined. The lake produced large (687–1138 mm, exclusively female silver eels, 61.7% of which were infected by A. crassus. Silver eel fecundity, the first estimates from the southern part of the species range, was positively related to body length (R2 = 0.693; P < 0.001 and body weight (R2 = 0.731; P < 0.001. Fecundity did not differ between A. crassus infected and uninfected silver eels, but Greek silver eels were significantly more fecund than those in north-west Europe. The reproductive potential of Vistonis Lake silver eels and their contribution to the A. anguilla spawning stock is discussed.

  3. Loss of European silver eel passing a hydropower station

    DEFF Research Database (Denmark)

    Pedersen, Michael Ingemann; Jepsen, Niels; Aarestrup, Kim

    2012-01-01

    The aim of this study was to assess escapement success of silver eels, Anguilla anguilla (L.), in a lowland river while passing a reservoir and a hydropower station. It was hypothesized that passage success would be lowest at the hydropower station and that survival and migration speed would...... be highest in the free-flowing river section upstream the reservoir. Forty-five female silver eels 56–86 cm in length were tagged with acoustic transmitters and released in November 2006. Their migration was monitored via automatic listening stations (ALS) in various sections of the river, covering a total...

  4. Endocrine profiles during silvering of the European eel (Anguilla anguilla L.) living in saltwater

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    Ginneken, van V.; Durif, C.; Dufour, C.; Sbaihi, M.; Boot, R.; Noorlander, K.; Doornbos, J.; Murk, A.J.; Thillart, van den G.

    2007-01-01

    The transformation of yellow eel into silver eel is called 'silvering', and takes place prior to migration. This is the first study to provide hormonal profiles of European eel (Anguilla anguilla L.) during silvering. This transformation occurs in association with hormonal surges of testosterone (T)

  5. The migration behaviour of European silver eels (Anguilla anguilla) released in open ocean conditions

    DEFF Research Database (Denmark)

    Wysujack, K.; Westerberg, H.; Aarestrup, Kim

    2015-01-01

    Despite some recent progress, there are still large gaps of knowledge about migration routes and behaviour of European eels, Anguilla anguilla, during their long-distance oceanic migration. To achieve a better understanding of the migration behaviour, 28 large female silver eels were equipped...... with pop-up satellite transmitters and released at three different locations in the north-eastern Atlantic Ocean and in the Sargasso Sea. The study covers tracking periods between 7 and 92 days. The distance between release point and estimated pop-up position ranged from 40 to 1000 km, the mean minimum...

  6. Should we train urologists in female urology? A European view.

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    Heesakkers, J.P.F.A.; Costantini, E.; Oelke, M.

    2009-01-01

    PURPOSE OF REVIEW: Training in female urology in Europe so far has been a national focus of individual European countries. Because of reasons like differentiation in pathology, activities of other specialisms like gynaecology and reimbursement issues, the way in which extra training in female

  7. A comparative study of female sterilization via modified Uchida and silver clip techniques in rural China.

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    Qiu, Hongyan; Li, Li; Wu, Shangchun; Liang, Hong; Yuan, Wei; He, Yingqin

    2011-03-01

    To compare the specific effects of 2 female sterilization methods: the modified Uchida technique and the application of silver clips. A total of 2198 women living in rural areas who were still of reproductive age but opting for sterilization were enrolled. The participants were randomly divided into 2 groups, and underwent sterilization by either modified Uchida technique or silver clips. Information on acceptability, operation conditions, effectiveness, adverse effects, and complaints was collected 3, 6, and 12 months after the procedure. No significant difference in effectiveness, adverse effects or chief complaints between the 2 procedures was found. Differences in operative outcome, bleeding volume during the procedure, and operation time were found. A shorter operation time and less bleeding for the silver clip method indicated that female sterilization by this technique was as safe as that by modified Uchida technique. Copyright © 2010 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  8. Survival and progression rates of large European silver eel Anguilla anguilla in late freshwater and early marine phases

    DEFF Research Database (Denmark)

    Aarestrup, Kim; Thorstad, Eva B.; Koed, Anders

    2010-01-01

    The population of European silver eel Anguilla anguilla has declined tremendously in the last decades. The cause of this decline is unknown, and it is necessary to investigate the migratory behaviour and survival rates of silver eels during the reproductive migration in order to understand...... was high in fresh water. However, 60% of eels were lost in the inner and outer fjord, supporting the hypothesis that mortality is large in the early phase of the marine migration and that fishing may be a major cause of mortality of silver eels. There was no indication that the slowest-migrating...... if the decline is related to factors acting during that migration. We estimated survival and progression rates of European silver eel migrating in the lower part of the River Gudenaa and during the first phase of the marine migration in the Randers Fjord in Denmark. Fifty migrating silver eel (total body length...

  9. Binding and movement of silver in the intestinal epithelium of a marine teleost fish, the European flounder (Platichthys flesus)

    DEFF Research Database (Denmark)

    Hogstrand, C.; Wood, C. M.; Bury, N.R.

    2002-01-01

    mixtures at concentrations ranging from 1.6 to 950 nM total silver. Appearance of 110mAg was analysed in mucosal scrapings, muscle layers, and in the plasma saline on the serosal side of the intestine. The latter represented uptake into blood and other extra-intestinal compartments. Mucosal scrapings......The intestine has been indicated as a site of waterborne silver toxicity in marine fish and chronic effects at the intestine have been observed at concentrations far below acutely toxic level. Thus, models of silver toxicity to marine fish need to consider the intestine as a biotic ligand....... The present study characterises binding of silver to the intestine of the European flounder (Platichthys flesus). Everted intestinal sacks were prepared and submersed in a solution mimicking the intestinal fluid of the fish at the acclimation salinity (21‰). Silver was added as 110mAgNO3 or 110mAgNO3/AgNO3...

  10. Kinetics of radiolabelled silver uptake and depuration in the gills of rainbow trout (Oncorhynchus mykiss) and European eel (Anguilla anguilla)

    DEFF Research Database (Denmark)

    Wood, C.M.; Grosell, M.; Hogstrand, C.

    2002-01-01

    We examined the influence of speciation on the kinetics of silver uptake and deputation in the gills of two freshwater fish, the rainbow trout (Oncorhynchus mykiss) which has high branchial Na+ and Cl- uptake rates and is relatively sensitive to silver, and the European eel (Anguilla anguilla...... labile than from Ag+ exposures, with 1.6-1.8-fold greater loss rates during the fast phases in both species. Differences in branchial silver uptake between eel and trout correlate well with differences in acute toxicity, but are not as large as differences in ion uptake rates. The complex time-dependent...

  11. Swimming physiology of European silver eels (Anguilla anguilla L.): energetic costs and effects on sexual maturation and reproduction

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    van den Thillart, Guido E. E. J. M.

    2010-01-01

    The European eel migrates 5,000–6,000 km to the Sargasso Sea to reproduce. Because they venture into the ocean in a pre-pubertal state and reproduce after swimming for months, a strong interaction between swimming and sexual maturation is expected. Many swimming trials have been performed in 22 swim tunnels to elucidate their performance and the impact on maturation. European eels are able to swim long distances at a cost of 10–12 mg fat/km which is 4–6 times more efficient than salmonids. The total energy costs of reproduction correspond to 67% of the fat stores. During long distance swimming, the body composition stays the same showing that energy consumption calculations cannot be based on fat alone but need to be compensated for protein oxidation. The optimal swimming speed is 0.61–0.67 m s−1, which is ~60% higher than the generally assumed cruise speed of 0.4 m s−1 and implies that female eels may reach the Sargasso Sea within 3.5 months instead of the assumed 6 months. Swimming trials showed lipid deposition and oocyte growth, which are the first steps of sexual maturation. To investigate effects of oceanic migration on maturation, we simulated group-wise migration in a large swim-gutter with seawater. These trials showed suppressed gonadotropin expression and vitellogenesis in females, while in contrast continued sexual maturation was observed in silver males. The induction of lipid deposition in the oocytes and the inhibition of vitellogenesis by swimming in females suggest a natural sequence of events quite different from artificial maturation protocols. PMID:20390348

  12. [The comparison of efficacy of female sterilization by modified Uchida technique and silver clips in China].

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    Qiu, Hong-yan; Zou, Yan; Li, Li; Liang, Hong; Zhang, Hong-yan; Wu, Shang-chun

    2011-02-01

    To compare efficacy of female sterilization by modified Uchida technique and silver clips and to evaluate the influence on operation procedure and clinical effect with or without surgery training of service providers. A comparative, multicenter clinical trial was performed in 18 county and township-level service centers. Totally 2198 women underwent sterilization from these 18 study center were divided into 1116 women sterilized by modified Uchida technique and 1082 women by silver clips. Those 18 centers were classified into 9 training groups which provide surgical skills of sterilization and other contents and 9 non training groups. Clinical documents of sterilization were recorded. All women were follow-up at 3, 6 and 12 months after surgery. There were no complications during surgery by both sterilization. The failure rate was 2.03% (22/1082) in silver clip method and the mean operative time were (12.4 ± 6.4) minutes in training group and (14.4 ± 8.1) minutes in non training group. In modified Uchida method, the failure rate was 0.18% (2/1116) and the mean operative time were (16.2 ± 4.9) minutes in training group and (19.0 ± 8.6) minutes in non training group. The mean operative time between two groups reached statistical difference (all P 0.05). There was no significant difference in acceptability and side effects of all women between two methods (P > 0.05). The training of service providers could influence acceptability of women (P < 0.05). Clinical efficacy was not influenced by those two methods. The operative time and acceptability were improved by training surgeons in silver clips method.

  13. Morphological separation of the Central European Trochosa females (Araneae, Lycosidae

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    Hepner, Martin

    2006-06-01

    Full Text Available Adult females of the five Central European wolf spiders Trochosa hispanica Simon, 1870, T. robusta (Simon, 1876, T. ruricola (DeGeer, 1778, T. spinipalpis (F.O.P.-Cambridge, 1895, and T. terricola Thorell, 1856 were morphologically analysed. We defined sets of continuous and binary (presence/absence variables. Continuous data of various epigynal and carapace dimensions were subjected to Principal Component Analysis (PCA. Using the PC loadings each individual was plotted along the PC axis in order to find gaps(overlaps between the species. The binary data sets were subjected to Hierarchical Cluster Analysis (HCA in order to find characters that clearly separate the five Trochosa species. Using PCA only individuals of T.robusta and T.ruricola and of T.robusta and T.hispanica could be separated from each other. Using HCA all five species could clearly be separated by epigynal and vulval characteristics."

  14. Sexual harassment in sport toward females in three European countries

    OpenAIRE

    Fasting, Kari; Chroni, Stilani; Hervik, Stein Egil; Knorre, Nada

    2011-01-01

    This article presents data from a cross-cultural study titled ‘Gender Relations in Sport — The Experiences of Czech, Greek, and Norwegian Female Sport Students’. The main research question asked is: what are the amounts and the forms of male and female sexual harassment experienced in a sport setting by female sport students in Czech Republic, Greece, and Norway? Women (N = 616) who were studying in sport departments of academic institutions in the three countries participated in the study. T...

  15. ATTEMPT TO ANALYSE THE DIFFERENCES BETWEEN EARLY MEDIEVAL FEMALE SILVER JEWELLERY FROM THE SOUTHWESTERN AND SOUTHEASTERN AREA OF POLAND

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    Dagmara Krol

    2015-09-01

    Full Text Available The article is an attempt to analyze female silver jewellery produces and used during Early Middle Ages in regions of southeastern and southwestern Poland. Those regions correspond to the area of nowadays Poland, respectively southwestern voivodeships: Dolnoslaskie, Slaskie, Opolskie, Malopolskie and southeastern voivodeships: Podkarpackie and Lubuskie.The presented work deals with similarities and differences in quality and types of jewellery from those regions. The analysis focuses on silver items found in settlements, cemeteries and hoards. The recovered female jewellery highlights the divergence between east, under influence of culture from Byzantine Empire, and west.Thanks to described archeological relics, the southern region of present Poland can be easily divided into two distinguishable parts representing different cultures.

  16. Changes in body weight and eye size in female European eel kept in fresh and salt water

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    Joanna Nowosad

    2014-05-01

    Full Text Available The eel is a catadromous fish which spends most of its life in freshwater and adults swim to the Sargasso Sea region to spawn. While preparing for the reproductive process, eels undergo a metamorphosis to become what is called silver eel; a process involving changes in the colour and weight of the body and an increase in the eye size. These are indicators of fish maturity and they facilitate the selection of fish for reproduction under controlled conditions. During this study, changes in the body weight (BW and eye size in female European eel were observed while being given weekly hormonal injections of 20 mg kg–1 carp pituitary homogenate and kept in 15°C freshwater and in 15°C saltwater with a salinity of 32-33‰. Fish kept in saltwater but not subjected to hormonal stimulation were used as a control group. Furthermore, after the experiment was finished, females in the control group were kept for next 5 months, with the same environmental parameters maintained. Differences between the treated groups were observed as early as week 4 of the experiment. An increase in fish BW was observed in fish kept both in salt and freshwater which were subjected to hormonal stimulation. On the other hand, changes in eye size were observed in the fish kept in saltwater, both in those hormonally stimulated and otherwise. The eye diameter in the fish kept in fresh after hormonal stimulation did not change significantly.

  17. Timing and pattern of annual silver eel migration in two European watersheds are determined by similar cues.

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    Sandlund, Odd Terje; Diserud, Ola H; Poole, Russell; Bergesen, Knut; Dillane, Mary; Rogan, Gerard; Durif, Caroline; Thorstad, Eva B; Vøllestad, Leif Asbjørn

    2017-08-01

    Many animals perform long-distance migrations in order to maximize lifetime reproductive success. The European eel migrates several thousand kilometers between their feeding habitats in continental waters (fresh-, brackish, and sea water) and their spawning area in the Sargasso Sea. Eels residing in freshwaters usually initiate their spawning migration as silver eels during autumn, triggered by diverse environmental cues. We analyzed the time series of silver eel downstream migration in Burrishoole, Ireland (1971-2015), and Imsa, Norway (1975-2015), to examine factors regulating the silver eel migration from freshwater to the sea. The migration season (90% of the run) generally lasted from 1 August to 30 November. Environmental factors acting in the months before migration impacted timing and duration of migration, likely through influencing the internal processes preparing the fish for migration. Once the migration had started, environmental factors impacted the day-to-day variation in number of migrants, apparently stimulating migration among those eels ready for migration. Both the day-to-day variation in the number of migrants and the onset of migration were described by nearly identical models in the two rivers. Variables explaining day-to-day variation were all associated with conditions that may minimize predation risk; number of migrants was reduced under a strong moon and short nights and increased during high and increasing water levels. Presence of other migrants stimulated migration, which further indicates that silver eel migration has evolved to minimize predation risk. The onset of migration was explained mainly by water levels in August. The models for duration of the migration season were less similar between the sites. Thus, the overall migration season seems governed by the need to reach the spawning areas in a synchronized manner, while during the actual seaward migration, antipredator behavior seems of overriding importance.

  18. Influence of temperature regime on endocrine parameters and vitellogenesis during experimental maturation of European eel (Anguilla anguilla) females

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    Perez, L.; Penaranda, D.S.; Dufour, S.; Baloche, S.; Palstra, A.P.; Thillart, G.E.E.J.M.; Asturiano, J.F.

    2011-01-01

    We examined the effect of temperature in European silver eels during their maturation induced by injections of carp pituitary extract on endocrine parameters: pituitary fshß and lhß expression, plasma 17ß-estradiol (E2) and vitellogenin, estrogen receptor 1 (esr1), and vitellogenin 2 (vtg2)

  19. "Governmentality" in the Origins of European Female PE and Sport: The Spanish Case Study (1883-1936)

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    Garcia, Raul Sanchez; Herraiz, Antonio Rivero

    2013-01-01

    The purpose of the paper is twofold: (1) to contribute to the analysis of the origins of modern European female PE and sports from a power perspective, inspired by Foucault's work; and (2) to present a detailed analysis of female PE and sport in Spain (1883-1936) as a specific European case study. It is argued that these physical activities could…

  20. Green synthesis, characterization and anti-inflammatory activity of silver nanoparticles using European black elderberry fruits extract.

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    David, Luminita; Moldovan, Bianca; Vulcu, Adriana; Olenic, Liliana; Perde-Schrepler, Maria; Fischer-Fodor, Eva; Florea, Adrian; Crisan, Maria; Chiorean, Ioana; Clichici, Simona; Filip, Gabriela Adriana

    2014-10-01

    This research aimed at reporting the synthesis, characterization and evaluation of the anti-inflammatory effects of some new biomaterials based on silver nanoparticles and polyphenols rich natural extracts. A fast and eco-friendly extracellular biosynthesis of silver nanoparticles (AgNPs), using European black elderberry (Sambucus nigra - SN, Adoxaceae family) fruit extracts was developed. The phytosynthesized nanoparticles exhibited an absorbance peak at 426nm, characteristic for AgNPs and their sizes were ranged from 20 to 80nm. The anti-inflammatory properties of AgNPs were assessed in vitro on HaCaT cells exposed to UVB radiation, in vivo on acute inflammation model and in humans on psoriasis lesions. In vitro, our results demonstrated the anti-inflammatory effects of functionalized AgNPs by the decrease of cytokines production induced by UVB irradiation. In vivo, the pre-administration of AgNPs reduced the edema and cytokines levels in the paw tissues, early after the induction of inflammation. The present study also demonstrated the possible use of synthesized AgNPs for the treatment of psoriasis lesions. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Female nutrition and assisted reproduction in European eel: influences on oogenesis and egg quality

    DEFF Research Database (Denmark)

    da Silva, Filipa

    maturation scale, which may result in an increase in production of viable European eel eggs. Overall, this PhD project contributed to the development of assisted reproduction procedures by providing new and valuable knowledge about the factors influencing the maturational response of European female eels...... in techniques for induction of maturation and fertilization of the eggs has enabled the production of many viable eggs and yolk-sac larvae that are able of exogenous feeding. The present studies have contributed to this progress by addressing some of the challenges commonly associated with the induction...

  2. Intraspecific brood parasitism: a strategy for floating females in the European starling.

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    Sandell; Diemer

    1999-01-01

    In many bird species, there is a floating population of females that are excluded from breeding because of competition for limited breeding resources. Female floaters may enhance their reproductive success by engaging in intraspecific brood parasitism. We studied female floaters in a population of European starlings, Sturnus vulgaris, in order to determine their identity and potential parasitic behaviour. Females were caught after being attracted to nestboxes with artificial nests during 1993-1995. None of the females was known to have a nest of her own at capture but 47% of the females either laid an egg in the nest or carried a fully developed egg within the reproductive tract, indicating that they were intraspecific brood parasites. The floating females were significantly younger and smaller than breeding females. Of 13 females equipped with radiotransmitters and followed daily, all but one started a breeding attempt of their own after 3-8 days and the majority settled as secondary females or mated with males where the original female had disappeared. This suggests that females that are unable to compete successfully for nest sites or males early in the breeding season may use intraspecific brood parasitism to enhance reproductive success during the period that they are constrained from breeding. The importance of settling rapidly because of a seasonal decline in reproductive success may also promote the evolution of intraspecific brood parasitism in the starling. The relative reproductive success of combining egg dumping with breeding compared with traditional breeding will depend on the costs of delaying breeding as well as the probability of finding a mate later in the breeding season. Copyright 1999 The Association for the Study of Animal Behaviour.

  3. EFFECTS OF SILVER NANOPARTICLES IN SOLUTION AND LIPOSOMAL FORM ON SOME BLOOD PARAMETERS IN FEMALE RABBITS DURING FERTILIZATION AND EARLY EMBRYONIC DEVELOPMENT

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    Vasyl Syrvatka

    2014-02-01

    Full Text Available Silver nanoparticles are the most rapidly growing classes of nanoproducts. In this study, we investigated the influence of subcutaneous injections of silver nanoparticles in solution and in liposomal form on hematological and biochemical parameters of blood of New Zealand White rabbits during hormonal treatment, fertilization and early embryonic development. The females treated by free silver nanoparticles and silver nanoparticles in liposomal form received silver at a dose of 10 µg/kg/day in 5 % glucose solution during 28 days. Blood sampling was done four times: the day before the compounds administration; on day 7 after the compounds administration; in the period after hormonal induction and fertilization and on the 14th day of pregnancy. Our results showed changes in some biochemical (lactate dehydrogenase activities, progesterone and estradiol concentration, malondialdehyde level, etc. and hematological (hematocrit, mean cell volume, mean corpuscular hemoglobin concentration, etc. parameters under the influence of hormonal treatment and pregnancy. The concentration of progesterone showed significantly higher values (P˂0.05 on GDs 1 in S group than in C group. The percentage of neutrophils was significantly higher in SG rabbits after 7 days of silver nanoparticles administration than that in the CG. There were no significant changes in red blood cells parameters, platelets, and activity of some ferments (ALP, AST, ALT, LDH, GGT between control and silver groups during the entire period of experiment. In conclusion, the hematological and biochemical values of blood obtained in the given study showed that free silver nanoparticles and silver nanoparticles in liposomal form in the investigated concentrations had no toxic effect on hormonal treatment, fertilization and early embryonic development in New Zealand White rabbits.

  4. Temporal progression in migratory status and sexual maturation in European silver eels during downstream migration

    NARCIS (Netherlands)

    Palstra, A.P.; Guerrero, M.A.; Klein Breteler, J.G.P.; Thillart, G.E.E.J.M.

    2011-01-01

    The onset of downstream migration of European eels is accompanied by a cessation of feeding and the start of sexual maturation which stresses the link between metabolism and sexual maturation, also suggesting an important role for exercise. Exercise has been tested with eels in swim tunnels and was

  5. Noninvasive monitoring of female reproductive hormone metabolites in the endangered European mink (Mustela lutreola).

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    Nagl, Astrid; Kneidinger, Nadja; Kiik, Kairi; Lindeberg, Heli; Maran, Tiit; Schwarzenberger, Franz

    2015-12-01

    This study examined the reproductive physiology of female European mink (Mustela lutreola) to augment the available information on estrus, ovulation, and pregnancy with the long-term goal of supporting ex situ breeding management of this highly endangered species. Fecal reproductive hormone metabolites were measured using EIAs for estrogen and 20-oxo-pregnane metabolites. Seasonal hormone profiles were established. A comparison of hormone fluctuations in pregnant and nonpregnant females showed that both estrogen and 20-oxo-pregnane metabolites were significantly elevated during gestation, which is 42 days in length. Delayed implantation or embryonic diapause does not occur in this species. Litter size was correlated with 20-oxo-pregnane levels but not with estrogen concentrations. During lactation, 20-oxo-pregnane metabolite levels remained higher than in nonpregnant females. The breeding season was characterized by peaks in vaginal cornified cells and fecal estrogen metabolite levels. Up to four peaks in estrogen levels were identified and confirmed that European mink are seasonally polyestrous. The results of 20-oxo-pregnane measurements indicated that hCG can be applied to induce ovulation. With the establishment of this noninvasive method, we present a new tool to support population management of this species. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Vitamin E supplementation increases the attractiveness of males' scent for female European green lizards.

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    Renáta Kopena

    2011-04-01

    Full Text Available In spite that chemoreception is important in sexual selection for many animals, such as reptiles, the mechanisms that confer reliability to chemical signals are relatively unknown. European green lizards (Lacerta viridis have substantial amounts of α-tocopherol ( = vitamin E in their femoral secretions. Because vitamin E is metabolically important and can only be attained from the diet, its secretion is assumed to be costly. However, its role in intraspecific communication is unknown.Here, we experimentally show that male European green lizards that received a dietary supplement of vitamin E increased proportions of vitamin E in their femoral secretions. Furthermore, our experiments revealed that females preferred to use areas scent marked by males with experimentally increased vitamin E levels in their secretions. Finally, female preferences were stronger when vitamin E differences between a pair of males' secretions were larger.Our results demonstrate that female green lizards are able to discriminate between males based on the vitamin E content of the males' femoral secretions. We suggest that the possible cost of allocating vitamin E to secretions, which might be dependent on male quality, may be a mechanism that confers reliability to scent marks of green lizards and allows their evolution as sexual signals.

  7. Vitamin E supplementation increases the attractiveness of males' scent for female European green lizards.

    Science.gov (United States)

    Kopena, Renáta; Martín, José; López, Pilar; Herczeg, Gábor

    2011-04-28

    In spite that chemoreception is important in sexual selection for many animals, such as reptiles, the mechanisms that confer reliability to chemical signals are relatively unknown. European green lizards (Lacerta viridis) have substantial amounts of α-tocopherol ( = vitamin E) in their femoral secretions. Because vitamin E is metabolically important and can only be attained from the diet, its secretion is assumed to be costly. However, its role in intraspecific communication is unknown. Here, we experimentally show that male European green lizards that received a dietary supplement of vitamin E increased proportions of vitamin E in their femoral secretions. Furthermore, our experiments revealed that females preferred to use areas scent marked by males with experimentally increased vitamin E levels in their secretions. Finally, female preferences were stronger when vitamin E differences between a pair of males' secretions were larger. Our results demonstrate that female green lizards are able to discriminate between males based on the vitamin E content of the males' femoral secretions. We suggest that the possible cost of allocating vitamin E to secretions, which might be dependent on male quality, may be a mechanism that confers reliability to scent marks of green lizards and allows their evolution as sexual signals.

  8. Skin-Color Preferences and Body Satisfaction among South Asian-Canadian and European-Canadian Female University Students.

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    Sahay, Sarita; Piran, Niva

    1997-01-01

    Examines skin-color preferences and body satisfaction among South Asian-Canadian and European-Canadian female university students. Hypothesizes that South Asian-Canadians would display a greater wish to be lighter in skin color than would European-Canadians and that the discrepancy would be greater the darker their skin color. Reports that the…

  9. What Affects Reintegration of Female Drug Users after Prison Release? Results of a European Follow-Up Study

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    Zurhold, Heike; Moskalewicz, Jacek; Sanclemente, Cristina; Schmied, Gabriele; Shewan, David; Verthein, Uwe

    2011-01-01

    The main objective of this follow-up study is to explore factors influencing the success or failure of women in reintegrating after their release from prison. Female drug users in five European cities were tracked after being released from prison. Out of 234 female prisoners contacted in prisons, 59 were included in the follow-up study. Structured…

  10. Endogenous, photoperiodic and hormonal control of the body weight rhythm in the female European hamster, Cricetus cricetus.

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    Canguilhem, B; Masson-Pévet, M; Pévet, P; Bentz, I

    1992-03-01

    1. Body weight and hibernation rhythms were followed on normal and castrated female European hamsters raised in different conditions of photoperiod and ambient temperature. 2. In the normal females, the photoperiod was more effective than the ambient temperature regarding the control of the body weight rhythm. 3. In the castrated females, testosterone was more effective than oestradiol in suppressing both body weight and hibernation rhythms. 4. In short photoperiod conditions, the existence of endogenous rhythmicity depends upon prior photoperiodic exposure of the animals.

  11. Anguillicola crassus infection significantly affects the silvering related modifications in steady state mRNA levels in gas gland tissue of the European eel

    Directory of Open Access Journals (Sweden)

    Bernd ePelster

    2016-05-01

    Full Text Available Using Illumina sequencing, transcriptional changes occurring during silvering in swimbladder tissue of the European eel have been analyzed by comparison of yellow eel and silver eel tissue samples. Functional annotation analysis based on GO terms revealed significant expression changes in a number of genes related to the extracellular matrix, important for the control of gas permeability of the swimbladder, and to ROS (reactive oxygen species defense, important to cope with reactive oxygen species generated under hyperbaric oxygen partial pressures. Focusing on swimbladder tissue metabolism, levels of several mRNA species encoding glucose transport proteins were several-fold higher in silver eels, while enzymes of the glycolytic pathway were not affected. The significantly higher steady state level of a transcript encoding for membrane bound carbonic anhydrase, however, suggested that CO2 production in the pentose phosphate shunt and diffusion of CO2 was of particular importance in silver eel swimbladder. In addition, the mRNA level of a large number of genes related to immune response and to sexual maturation was significantly modified in the silver eel swimbladder. The modification of several processes related to protein metabolism and transport, cell cycle, and apoptosis suggested that these changes in swimbladder metabolism and permeability were achieved by increasing cell turn-over. The impact of an infection of the swimbladder with the nematode Anguillicola crassus has been assessed by comparing these expression changes with expression changes observed between uninfected yellow eel swimbladder tissue and infected silver eel swimbladder tissue. In contrast to uninfected silver eel swimbladder tissue, in infected tissue the mRNA level of several glycolytic enzymes was significantly elevated, and with respect to extracellular matrix, several mucin genes were many-fold higher in their mRNA level. Modification of many immune related genes and

  12. Female ever-smoking, education, emancipation and economic development in 19 European countries

    DEFF Research Database (Denmark)

    Schaap, Maartje M; Kunst, Anton E; Leinsalu, Mall

    2009-01-01

    product (GDP) and the Gender Empowerment Measure (GEM) was explored. Less educated women aged 25-39 years were more likely to have ever smoked than more educated women in all countries, except Portugal. In the age groups 40-59 years the educational pattern differed between countries. Women aged 60+ years...... for more educated women. The association of ever-smoking rates with GEM was positive for less educated women, but negative for more educated women. The results are consistent with the idea that economic development and social-cultural processes related to gender empowerment have affected the diffusion......Large differences in ever-smoking rates among women are found between countries and socio-economic groups. This study examined the socio-economic inequalities in female ever-smoking rates in 19 European countries, and explored the association between cross-national differences in these inequalities...

  13. Female Reproductive Disorders, Diseases, and Costs of Exposure to Endocrine Disrupting Chemicals in the European Union

    Science.gov (United States)

    Hunt, Patricia A.; Sathyanarayana, Sheela; Fowler, Paul A.

    2016-01-01

    Context: A growing body of evidence suggests that endocrine-disrupting chemicals (EDCs) contribute to female reproductive disorders. Objective: To calculate the associated combined health care and economic costs attributable to specific EDC exposures within the European Union (EU). Design: An expert panel evaluated evidence for probability of causation using the Intergovernmental Panel on Climate Change weight-of-evidence characterization. Exposure-response relationships and reference levels were evaluated, and biomarker data were organized from carefully identified studies from the peer-reviewed literature to represent European exposure and approximate burden of disease as it occurred in 2010. Cost-of-illness estimation used multiple peer-reviewed sources. Setting, Patients and Participants and Intervention: Cost estimation was carried out from a societal perspective, ie, including direct costs (eg, treatment costs) and indirect costs such as productivity loss. Results: The most robust EDC-related data for female reproductive disorders exist for 1) diphenyldichloroethene-attributable fibroids and 2) phthalate-attributable endometriosis in Europe. In both cases, the strength of epidemiological evidence was rated as low and the toxicological evidence as moderate, with an assigned probability of causation of 20%–39%. Across the EU, attributable cases were estimated to be 56 700 and 145 000 women, respectively, with total combined economic and health care costs potentially reaching €163 million and €1.25 billion. Conclusions: EDCs (diphenyldichloroethene and phthalates) may contribute substantially to the most common reproductive disorders in women, endometriosis and fibroids, costing nearly €1.5 billion annually. These estimates represent only EDCs for which there were sufficient epidemiologic studies and those with the highest probability of causation. These public health costs should be considered as the EU contemplates regulatory action on EDCs. PMID

  14. The Situation of the Female Workforce in the Field of Scientific Research in European Countries

    Directory of Open Access Journals (Sweden)

    CRISTINA LEOVARIDIS

    2010-04-01

    Full Text Available This study aims at identifying if and to what extent we can speak of the existence of gender imbalances in the field of scientific research in the European Union as a whole, but also comparatively between different countries, including the situation in Romania. After a short overview of the context in which this preoccupation appeared in European gender studies and of the possible causes which can determine this imbalance, the paper continues with a presentation of the general situation of the female/male workforce in the member states, followed by a analysis of the educational levels of women compared with men, with respect to stages of education. The study also analyzes the data on the participation of women in the field of scientific research from the point of view of share of the total, broken down by sectors of activity and scientific fields. A related focus is the participation of women in the field of higher education, according to hierarchical levels, from the perspective of access to research financing, of expenses per researchers, etc., focusing on the gender imbalances pointed out earlier and on the specificity of former communist countries.

  15. Reproductive state modulates testosterone-induced singing in adult female European starlings (Sturnus vulgaris).

    Science.gov (United States)

    Rouse, Melvin L; Stevenson, Tyler J; Fortune, Eric S; Ball, Gregory F

    2015-06-01

    European starlings (Sturnus vulgaris) exhibit seasonal changes in singing and in the volumes of the neural substrate. Increases in song nuclei volume are mediated at least in part by increases in day length, which is also associated with increases in plasma testosterone (T), reproductive activity, and singing behavior in males. The correlations between photoperiod (i.e. daylength), T, reproductive state and singing hamper our ability to disentangle causal relationships. We investigated how photoperiodic-induced variation in reproductive state modulates the effects of T on singing behavior and song nuclei volumes in adult female starlings. Female starlings do not naturally produce measureable levels of circulating T but nevertheless respond to exogenous T, which induces male-like singing. We manipulated photoperiod by placing birds in a photosensitive or photorefractory state and then treated them with T-filled or empty silastic implants. We recorded morning singing behavior for 3 weeks, after which we assessed reproductive condition and measured song nuclei volumes. We found that T-treated photosensitive birds sang significantly more than all other groups including T-treated photorefractory birds. All T-treated birds had larger song nuclei volumes than with blank-treated birds (despite photorefractory T-treated birds not increasing song-rate). There was no effect of photoperiod on the song nuclei volumes of T-treated birds. These data show that the behavioral effects of exogenous T can be modulated by reproductive state in adult female songbirds. Furthermore, these data are consistent with other observations that increases in singing rate in response to T are not necessarily due to the direct effects of T on song nuclei volume. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Accumulation of neurotoxic organochlorines and trace elements in brain of female European eel (Anguilla anguilla).

    Science.gov (United States)

    Bonnineau, C; Scaion, D; Lemaire, B; Belpaire, C; Thomé, J-P; Thonon, M; Leermaker, M; Gao, Y; Debier, C; Silvestre, F; Kestemont, P; Rees, J-F

    2016-07-01

    Xenobiotics such as organochlorine compounds (OCs) and metals have been suggested to play a significant role in the collapse of European eel stocks in the last decades. Several of these pollutants could affect functioning of the nervous system. Still, no information is so far available on levels of potentially neurotoxic pollutants in eel brain. In present study, carried out on female eels caught in Belgian rivers and canals, we analyzed brain levels of potentially-neurotoxic trace elements (Ag, Al, As, Cd, Co, Cr, Cu, Fe, Hg, MeHg, Mn, Ni, Pb, Sn, Sb, Zn) and OCs (Polychlorinated biphenyls, PCBs; Hexachlorocyclohexanes, HCHs; Dichlorodiphenyltrichloroethane and its metabolites, DDTs). Data were compared to levels in liver and muscle tissues. Eel brain contained very high amounts of OCs, superior to those found in the two other tissues. Interestingly, the relative abundance of PCB congeners markedly differed between tissues. In brain, a predominance of low chlorinated PCBs was noted, whereas highly chlorinated congeners prevailed in muscle and liver. HCHs were particularly abundant in brain, which contains the highest amounts of β-HCH and ϒ-HCH. p,p'-DDTs concentration was similar between brain and muscle (i.e., about twice that of liver). A higher proportion of p,p'-DDT was noticed in brain. Except for Cr and inorganic Hg, all potentially neurotoxic metals accumulated in brain to levels equal to or lower than hepatic levels. Altogether, results indicate that eel brain is an important target for organic and, to a lesser extent, for inorganic neurotoxic pollutants. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Female genital mutilation : a hidden epidemic (statement from the European Academy of Paediatrics)

    NARCIS (Netherlands)

    Sauer, Pieter J. J.; Neubauer, David

    Female genital mutilation or female circumcision is frequently performed worldwide. It is estimated by the World Health Organisation that worldwide, 100-140 million girls and women currently have to live with the consequences of female genital mutilation. The article argues that the tradition is one

  18. The Experiences of Sexual Harassment in Sport and Education among European Female Sports Science Students

    Science.gov (United States)

    Fasting, Kari; Chroni, Stiliani; Knorre, Nada

    2014-01-01

    The study investigates whether sport is an especially risky environment for sexual harassment to occur. It explores female students' experiences of sexual harassment in organized sport and compares them with their experiences in formal education, by addressing the following research questions: (1) Are there any differences in female sport…

  19. An exposure study with polybrominated diphenyl ethers (PBDEs) in female European starlings (Sturnus vulgaris): Toxicokinetics and reproductive effects

    Energy Technology Data Exchange (ETDEWEB)

    Steen, Evi van den [Laboratory of Ethology, Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium)], E-mail: evi.vandensteen@ua.ac.be; Eens, Marcel [Laboratory of Ethology, Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Covaci, Adrian [Toxicological Centre, University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, 2610 Wilrijk (Belgium); Dirtu, Alin C. [Toxicological Centre, University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, 2610 Wilrijk (Belgium); Department of Inorganic and Analytical Chemistry, ' Al.I.Cuza' University of Iassy, Carol I Bvd. No 11, 700506 Iassy (Romania); Jaspers, Veerle L.B. [Laboratory of Ethology, Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Neels, Hugo [Toxicological Centre, University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, 2610 Wilrijk (Belgium); Pinxten, Rianne [Laboratory of Ethology, Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium)

    2009-02-15

    We exposed female European starlings to a pentabromodiphenyl ether (Penta-BDE) mixture through subcutaneous implants, and examined levels and profiles of polybrominated diphenyl ethers (PBDEs) together with reproductive effects. Sum PBDE levels increased significantly in the serum of the exposed females from 218 {+-} 43 to 23,400 {+-} 2035 pg/ml. Sum PBDE concentrations in the eggs of the exposed group ranged from 130 {+-} 12 to 220 {+-} 37 ng/g wet weight (ww). The profile in serum after egg laying was very similar to that in eggs. There were no detectable levels of HO-PBDEs in both serum and eggs. Fewer females of the exposed group initiated egg laying compared to the control group, although the difference was not significant. In addition, egg weight and volume were significantly higher in the exposed group. These results suggest that, at the investigated exposure levels (150 {mu}g sum PBDEs/bird), PBDEs may have a negative effect on reproductive performance. - Exposure to an environmentally relevant concentration of PBDEs may result in adverse reproductive effects in a terrestrial songbird species, the European starling.

  20. Towards an ethnographic understanding of the European Marriage Pattern: Global correlates and links with female status

    NARCIS (Netherlands)

    Carmichael, S.G.; van Zanden, J.L.

    2015-01-01

    This contribution compares the EMP, and the associated Western European family system (inheritance practices, intergenerational co-residence and exogamy), with what is known about family systems and marriage patterns in the rest of the world, with a special focus on the consequences of these family

  1. Reproductive state modulates testosterone-induced singing in adult female European starlings (Sturnus vulgaris)

    OpenAIRE

    Rouse, Melvin L.; Stevenson, Tyler J.; Fortune, Eric S.; Ball, Gregory F.

    2015-01-01

    European starlings (Sturnus vulgaris) exhibit seasonal changes in singing and in the volumes of the neural substrate. Increases in song nuclei volume are mediated at least in part by increases in day length, which is also associated with increases in plasma testosterone (T), reproductive activity, and singing behavior in males. The correlations between photoperiod (i.e. daylength), T, reproductive state and singing hamper our ability to disentangle causal relationships. We investigated how ph...

  2. The senior female international managerial career move: a qualitative study in a European context

    OpenAIRE

    Linehan, Margaret

    1998-01-01

    Research investigating the position of women in management has, largely, been confined within national boundaries. Over the last fifteen years, empirical studies of women in international management have been undertaken, predominantly in North America. In this research field, many questions remain unanswered or have been only partially addressed. The particular focus of this study is on the senior female international managerial career move in Europe — a relatively unexplored area. Fifty seni...

  3. Application of talcum powder, trichloroacetic acid and silver nitrate in female rats for non-surgical sterilization: evaluation of the apoptotic pathway mRNA and miRNA genes.

    Science.gov (United States)

    Yumrutas, Onder; Kara, Murat; Atilgan, Remzi; Kavak, Salih Burcin; Bozgeyik, Ibrahim; Sapmaz, Ekrem

    2015-04-01

    There are several methods used for non-surgical sterilization in birth control including quinacrine, trichloroacetic acid (TCA), erythromycin, tetracycline, silver nitrate and talcum powder. Among these, talcum powder, TCA and silver nitrate are the most commonly used. However, the toxic and carcinogenic activities of these chemicals in ovarian tissue have been poorly elucidated. This study demonstrates the expression levels of antioxidant, apoptotic and anti-apoptotic genes after administration of talc powder, TCA and silver nitrate for non-surgical sterilization in female rat models. The expression changes of some microRNAs (miR-15b, miR-21, miR-34a and miR-98) that play key roles in the apoptosis pathway were also included. All expression analyses were evaluated with real-time PCR. The expression levels of all genes appeared to be upregulated in the talcum powder group, but the results were not statistically significant. Increased expression of Gsr and Sod1 genes was statistically significant in the talcum powder group. In TCA and silver nitrate group, expression of all genes was appeared to be elevated but only the Gsr expression was statistically significant in the TCA-administrated group; there were no statistically significant changes in the silver nitrate group. miRNA expression levels were increased in talcum powder and TCA-administrated groups, but these results were not significant. Expression levels of miR-15b, miR-21 and miR-98 in the silver nitrate group were significantly increased. Consequently, these chemicals appear to be non-carcinogenic agents for rat ovarian tissue which do not induce apoptosis. However, talcum powder and TCA can be considered as agents that are toxic to ovarian tissue. © 2015 The Authors. International Journal of Experimental Pathology © 2015 International Journal of Experimental Pathology.

  4. The Tripler Army Medical Center's LE3AN program: a six-month retrospective analysis of program effectiveness for African-American and European-American females.

    Science.gov (United States)

    Simpson, Mark; Earles, Jay; Folen, Raymond; Trammel, Rick; James, Larry

    2004-10-01

    This is a retrospective study that examines the effectiveness of the Tripler Army Medical Center (TAMC) LE3AN Program for weight management among African-American and European American women. African-American and European-American active-duty females who enrolled in the TAMC LE3AN Program between July 1998 and December 2001, and completed six months of follow-up were included in the analysis. The results indicate that the program is associated with significant weight loss for participants, and that it is equally effective for African-American and European-American women. Weekly follow-up visits were correlated with greater weight loss.

  5. Using RNA sequencing to characterize female reproductive genes between Z and E Strains of European Corn Borer moth (Ostrinia nubilalis).

    Science.gov (United States)

    Al-Wathiqui, Nooria; Lewis, Sara M; Dopman, Erik B

    2014-03-12

    Reproductive proteins often evolve rapidly and are thought to be subject to strong sexual selection, and thus may play a key role in reproductive isolation and species divergence. However, our knowledge of reproductive proteins has been largely limited to males and model organisms with sequenced genomes. With advances in sequencing technology, Lepidoptera are emerging models for studies of sexual selection and speciation. By profiling the transcriptomes of the bursa copulatrix and bursal gland from females of two incipient species of moth, we characterize reproductive genes expressed in the primary reproductive tissues of female Lepidoptera and identify candidate genes contributing to a one-way gametic incompatibility between Z and E strains of the European corn borer (Ostrinia nubilalis). Using RNA sequencing we identified transcripts from ~37,000 and ~36,000 loci that were expressed in the bursa copulatrix or the bursal gland respectively. Of bursa copulatrix genes, 8% were significantly differentially expressed compared to the female thorax, and those that were up-regulated or specific to the bursa copulatrix showed functional biases toward muscle activity and/or organization. In the bursal gland, 9% of genes were differentially expressed compared to the thorax, with many showing reproduction or gamete production functions. Of up-regulated bursal gland genes, 46% contained a transmembrane region and 16% possessed secretion signal peptides. Divergently expressed genes in the bursa copulatrix were exclusively biased toward protease-like functions and 51 proteases or protease inhibitors were divergently expressed overall. This is the first comprehensive characterization of female reproductive genes in any lepidopteran system. The transcriptome of the bursa copulatrix supports its role as a muscular sac that is the primary site for disruption of the male ejaculate. We find that the bursal gland acts as a reproductive secretory body that might also interact with male

  6. RESEARCH ON THE COMPETITIVE PERFORMANCE OF THE BULGARIAN NATIONAL TEAM OF UNDER – 16 FEMALE PLAYERS IN THE EUROPEAN CHAMPIONSHIP, DIVISION B IN 2012

    OpenAIRE

    Tsanko Tsankov; Jasmine Tsankova

    2013-01-01

    In today's basketball, the opinion that achieving high and stable sports results can be realized only by science-based long-term preparation is gaining more and more popularity. A major part of this preparation is the participation of adolescent female players in European Championships for the respective age group. The purpose of this study is to analyze the competitive performance of the Bulgarian National basketball team, consisting of female players up to 16 years of age, who took part in ...

  7. Identification of the Female-Produced Sex Pheromone of an Invasive Greenhouse Pest, the European Pepper Moth (Duponchelia fovealis).

    Science.gov (United States)

    Molnár, Péter Béla; Bognár, Csengele; Erdei, Anna Laura; Fujii, Takeshi; Vági, Pál; Jósvai, Júlia Katalin; Kárpáti, Zsolt

    2018-01-29

    The European pepper moth (Duponchelia fovealis, Lepidoptera, Crambidae, Spilomelinae) is an invasive pest of greenhouses in many countries, causing serious damages to horticultural plants. Coupled gas chromatographic-electroantennographic detection analysis of the female gland extract revealed two antennally active peaks. Using coupled gas chromatography-mass spectrometry (GC-MS), one was identified as (Z)-11-hexadecenal (Z11-16:Ald); however, further analysis on different types of capillary columns indicated that the second active compound has two different isomers, (E)-13-octadecenal (E13-18:Ald) and (Z)-13-octadecenal (Z13-18:Ald). The approximate ratio of E13-18:Ald, Z13-18:Ald and Z11-16:Ald in the crude pheromone gland extract was 10:1:0.1, respectively. Single sensillum recordings showed that there was one sensory neuron that responded with a high amplitude spike to both E13-18:Ald and Z13-18:Ald, while another neuron housed in the same sensillum responded to Z11-16:Ald. Field evaluation of the identified compounds indicated that the E13-18:Ald was necessary to evoke the attraction of males; although the presence of Z13-18:Ald and Z11-16:Ald increased the catches in traps. The highest number of caught males was achieved when E13-18:Ald, Z13-18:Ald and Z11-16:Ald were present in baits in the same ratio as in the female gland extract. This pheromone can be used in a monitoring strategy and could potentially lead to the development of mating disruption.

  8. Silver Nanoparticles

    Science.gov (United States)

    Khaydarov, R. R.; Khaydarov, R. A.; Estrin, Y.; Evgrafova, S.; Scheper, T.; Endres, C.; Cho, S. Y.

    The bactericidal effect of silver nanoparticles obtained by a novel electrochemical method on Escherichia coli, Staphylococcus aureus, Aspergillus niger and Penicillium phoeniceum cultures has been studied. The tests conducted have demonstrated that synthesized silver nanoparticles — when added to water paints or cotton fabrics — show a pronounced antibacterial/antifungal effect. It was shown that smaller silver nanoparticles have a greater antibacterial/antifungal efficacy. The paper also provides a review of scientific literature with regard to recent developments in the field of toxicity of silver nanoparticles and its effect on environment and human health.

  9. Analysis using national databases reveals a positive association between dietary polyunsaturated fatty acids with TV watching and diabetes in European females.

    Science.gov (United States)

    Pither, Jason; Botta, Amy; Maity, Chittaranjan; Ghosh, Sanjoy

    2017-01-01

    In recent years, dietary polyunsaturated fatty acids (PUFA) have increased in parallel to sedentary behavior and diabetes across the world. To test any putative association between dietary PUFA and sedentary behavior or diabetes in females, we obtained country-specific, cross-sectional data on sedentary activity and diabetes prevalence from European Cardiovascular Statistics 2012. Age and gender-specific, nutritional data from each country were obtained from nutritional surveys as well. Socioeconomic (GDP), physical environment (urbanization index) and climatic confounders were accounted for each country. Upon analysis, we found a strong, positive association between sedentary lifestyle in 11-yr old girls (> = 2 hours of TV/ weekday) and dietary PUFA across 21 European countries. Further, a weak association of dietary PUFA and a strong relationship of per-capita GDP was established with elevated fasting blood glucose [(> = 7.0 mmol/L; or on medication] among 25+ year old adult females across 23 countries in Europe. In summary, we present novel ecological evidence that dietary PUFA is strongly associated with sedentary behavior among pre-teen girls and weakly associated with diabetes among adult women across Europe. In the latter group, per-capita GDP was a significant predictor for diabetes as well. Therefore, we recommend that prospective randomized controlled trials (RCTs) be implemented to evaluate if ubiquitous presence of dietary PUFA and low socioeconomic status are possible confounders when intervening to treat/prevent sedentary lifestyle or diabetes in female subjects in Western nations.

  10. Analysis using national databases reveals a positive association between dietary polyunsaturated fatty acids with TV watching and diabetes in European females.

    Directory of Open Access Journals (Sweden)

    Jason Pither

    Full Text Available In recent years, dietary polyunsaturated fatty acids (PUFA have increased in parallel to sedentary behavior and diabetes across the world. To test any putative association between dietary PUFA and sedentary behavior or diabetes in females, we obtained country-specific, cross-sectional data on sedentary activity and diabetes prevalence from European Cardiovascular Statistics 2012. Age and gender-specific, nutritional data from each country were obtained from nutritional surveys as well. Socioeconomic (GDP, physical environment (urbanization index and climatic confounders were accounted for each country. Upon analysis, we found a strong, positive association between sedentary lifestyle in 11-yr old girls (> = 2 hours of TV/ weekday and dietary PUFA across 21 European countries. Further, a weak association of dietary PUFA and a strong relationship of per-capita GDP was established with elevated fasting blood glucose [(> = 7.0 mmol/L; or on medication] among 25+ year old adult females across 23 countries in Europe. In summary, we present novel ecological evidence that dietary PUFA is strongly associated with sedentary behavior among pre-teen girls and weakly associated with diabetes among adult women across Europe. In the latter group, per-capita GDP was a significant predictor for diabetes as well. Therefore, we recommend that prospective randomized controlled trials (RCTs be implemented to evaluate if ubiquitous presence of dietary PUFA and low socioeconomic status are possible confounders when intervening to treat/prevent sedentary lifestyle or diabetes in female subjects in Western nations.

  11. Interactive effects of dietary composition and hormonal treatment on reproductive development of cultured female European eel, Anguilla anguilla

    DEFF Research Database (Denmark)

    da Silva, Filipa; Støttrup, Josianne Gatt; Kjørsvik, Elin

    2016-01-01

    weight (BW) and ii) a variable hormone dosage that increased from 12.5mg SPE/kg initial BW to 25mg SPE/kg initial BW. Results showed a significant interaction between diets and hormonal treatments on gonadosomatic index (GSI), indicating that the effect of broodstock diets on ovarian development depends......) in the plasma did not differ between diets and hormonal treatments, but was significantly correlated with ovarian developmental stage. In conclusion, increasing dietary levels of n-3 PUFAs seemed to promote oocyte growth, leading to a more rapid progression of ovarian development in European eel subjected...

  12. Physical demands on young elite European female basketball players with special reference to speed, agility, explosive strength, and take-off power.

    Science.gov (United States)

    Erčulj, Frane; Blas, Mateja; Bračič, Mitja

    2010-11-01

    The aim of the study was to determine and analyze the level of certain motor abilities (acceleration and agility, the explosive strength of arms, and take-off power) of young elite European female basketball players. We also wanted to establish whether there were any differences between 3 groups of female basketball players who differed in terms of their playing performance. The sample of subjects consists of 65 female basketball players aged 14.49 (± 0.61) years who were divided into 3 groups (divisions A, B, and C of the European Championships). We compare the groups by using 8 motor tests. p Values <0.05 were considered statistically significant. The results show that the division C players achieved below-average results in all tests and thus differ from the players from divisions A and B whose test results were relatively homogeneous. The division C players differ from those from divisions A and B mainly in the 6 × 5-m sprint dribble (discriminant ratio coefficients [DRC] = 0.435), medicine ball throw (DRC = 0.375), and 20-m sprint (DRC = 0.203). Discriminatory power in the 6 × 5-m sprint dribble and 20-m sprint tests is preserved even after eliminating the effect of body height. We assume that, besides the deficit in body height and training status, this is also 1 of the key reasons for these players' lower playing efficiency compared to those from divisions A and B. We hope the findings of this study will enable the generation of model values, which can assist basketball coaches for this age category in basketball clubs, high schools, national teams, and basketball camps.

  13. Relationship between Personality Traits and Nicotine Dependence in Male and Female Smokers of African-American and European-American Samples.

    Science.gov (United States)

    Choi, Jung-Seok; Payne, Thomas J; Ma, Jennie Z; Li, Ming D

    2017-01-01

    Personality characteristics are linked to nicotine dependence (ND). It remains unclear whether these factors differ across African-American (AA) and European-American (EA) male and female smokers. This study was aimed to determine the relationship between personality traits and smoking status, as well as the degree of ND, in AA and EA male and female samples. A total of 5,040 participants (AA: N = 3,737, female = 54.31%; EA: N = 1,313, female = 64.51%) were included in this study, with 2,474 smokers and 2,566 non-smokers. The measures used in this study included five dimensions of personality by the NEO-personality inventory-revised (neuroticism, extraversion, agreeableness, openness to experience, and conscientiousness), Fagerström test for ND, and drive subscale of the ND Syndrome Scale (NDSS). In the AA sample, neuroticism was significantly associated with a higher risk of smoking [odds ratio (OR) = 1.057; 95% confidence interval (CI) 1.032, 1.083; p smoking (OR = 0.936; 95% CI 0.912, 0.961; p predicting the severity of ND in the AA samples. However, no differential association was detected between male and female smokers of both AA and EA samples. There exist differential relationships between personality traits and the severity of ND in the AA and EA samples.

  14. Comparative assessment of study groups of elderly female computer users from four European countries: questionnaires used in the NEW study

    DEFF Research Database (Denmark)

    Sandsjö, L; Larsman, P; Vollenbroek-Hutten, M M R

    2006-01-01

    There is a lack of consistent and comprehensive questionnaire forms for the studies of factors associated with work-related musculoskeletal disorders at the European level. One of the results of the EU-funded project, neuromuscular assessment in the elderly worker (NEW), is a set of questionnaires...... for the screening of musculoskeletal status and the studies of factors that are believed to affect musculoskeletal health. The questionnaires have been used among elderly women (45+) in different occupations and organisations in Denmark, The Netherlands, Sweden and Switzerland. The aim of this short communication...... is to present the questionnaires used in the NEW study and to evaluate the appropriateness of pooling data gathered in each participating country into a common database. It is concluded that although differences exist among the study samples, these are not of such a magnitude or pattern that data from the four...

  15. Russell-Silver syndrome

    Science.gov (United States)

    Silver-Russell syndrome; Silver syndrome; RSS; Russell-Silver syndrome ... One in 10 children with this syndrome has a problem involving chromosome 7. In other people with the syndrome, it may affect chromosome 11. Most of the time, it ...

  16. RESEARCH ON THE COMPETITIVE PERFORMANCE OF THE BULGARIAN NATIONAL TEAM OF UNDER – 16 FEMALE PLAYERS IN THE EUROPEAN CHAMPIONSHIP, DIVISION B IN 2012

    Directory of Open Access Journals (Sweden)

    Tsanko Tsankov

    2013-07-01

    Full Text Available In today's basketball, the opinion that achieving high and stable sports results can be realized only by science-based long-term preparation is gaining more and more popularity. A major part of this preparation is the participation of adolescent female players in European Championships for the respective age group. The purpose of this study is to analyze the competitive performance of the Bulgarian National basketball team, consisting of female players up to 16 years of age, who took part in the European Championship, Division B, held in Tallinn, Estonia from 12 to 22 July 2012. For the purpose of the study information was gathered on the gaming performance of the players of the national team in all 9 played matches, comparing them by 16 indicators. The unit of observation of this study was the single game. The team competitive efficiency is a combination of the gaming performance of all players involved in the basketball game, regardless of the time that they were actually playing in the match. After analyzing the surveyed indicators, the following conclusions were made and those need to be the ground for the future education and training program of the researched national team, namely: increased activity in shooting from the two-point and three-point lines; increasing the effectiveness of the shooting from the two-point line and the free throws; improved ability to pass accurate (in space, time and effort assists; improving the technique of blocking in defense and offense; improving the quality and the aggressiveness in defense play, which would increase the number of steals, but not at the expense of increased number of fouls.

  17. Alcohol-related blackouts across 55 weeks of college: Effects of European-American ethnicity, female sex, and low level of response to alcohol.

    Science.gov (United States)

    Schuckit, Marc A; Smith, Tom L; Goncalves, Priscila Dib; Anthenelli, Robert

    2016-12-01

    While high blood alcohol concentrations (BACs) are required for alcohol-related blackouts (ARBs), additional characteristics also contribute to the risk, including a person's ethnicity, sex, and phenotypes relating to heavier drinking. Few prospective studies of ARBs have evaluated how these additional characteristics interact. Data regarding 398 European American (EA), Asian and Hispanic students were extracted from a 55-week prospective study of different approaches to decrease heavy drinking among college freshmen. Information on past month ARB frequency was determined at 8 assessments. While controlling for the prior month maximum BAC and active education vs. control group assignment, the patterns and intensities of ARBs over time across ethnic groups were evaluated with ANOVA at each follow-up for the full sample, and then separately by sex and then by low vs. high levels of response to alcohol status (LR). The overall pattern of ARBs over time was evaluated with a 3 ethnic groups by 2 sexes by 2 LR status by 8 time points mixed-design ANOVA. Higher rates of ARBs over time were associated with EA ethnicity, female sex and a low LR to alcohol, with the ethnic differences in ARBs most robust in females and drinkers with high LRs. Participation in education programs aimed at heavy drinking was associated with decreases in ARBs. The data indicate that in addition to BACs achieved, propensities toward ARBs relate to complex interactions between additional risk factors, including ethnicity, sex, and LR status. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Silver deposition on stainless steel container surfaces in contact with disinfectant silver aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Petala, M., E-mail: petala@civil.auth.gr [Department of Civil Engineering, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Tsiridis, V. [Department of Civil Engineering, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Mintsouli, I. [Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Pliatsikas, N. [Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Spanos, Th. [Department of Petroleum and Mechanical Engineering Sciences, Eastern Macedonia and Thrace Institute of Technology, Kavala, 65404 (Greece); Rebeyre, P. [ESA/ESTEC, P.O.Box 299, 2200 AG, Noordwijk (Netherlands); Darakas, E. [Department of Civil Engineering, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Patsalas, P.; Vourlias, G. [Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Kostoglou, M.; Sotiropoulos, S.; Karapantsios, Th. [Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece)

    2017-02-28

    Highlights: • Silver is one of the biocides of water consumed in the International Space Station. • Ionic silver is depleted from potable water when in contact with stainless steel (SS). • SEM and XPS analysis reveal a uniform silver deposition over the SS surface. • Silver deposits in its metallic form, in line with a galvanic deposition mechanism. • Evidence is provided that Cr and/ or Ni oxide builds-up on SS surfaces. - Abstract: Silver is the preservative used on the Russian segment of the International Space Station (ISS) to prevent microbial proliferation within potable water supplies. Yet, in the frame of the European Automated Transfer Vehicle (ATV) missions to ISS, silver depletion from water has been detected during ground transportation of this water to launch site, thereby indicating a degradation of water quality. This study investigates the silver loss from water when in contact with stainless steel surfaces. Experiments are conducted with several types of stainless steel surfaces being exposed to water containing 10 or 0.5 mg/L silver ions. Results show that silver deposits on stainless steel surfaces even when a passivation layer protects the metallic surface. The highest protection to silver deposition is offered by acid passivated and electropolished SS 316L. SEM and XPS experiments were carried out at several locations of the sample area that was in contact with the Ag solution and found similar morphological (SEM) and compositional (sputter-etch XPS) results. The results reveal that silver deposits uniformly across the wetted surface to a thickness larger than 3 nm. Moreover, evidence is provided that silver deposits in its metallic form on all stainless steel surfaces, in line with a galvanic deposition mechanism. Combination of ICP-MS and XPS results suggests a mechanism for Ag deposition/reduction with simultaneous substrate oxidation resulting in oxide growth at the exposed stainless steel surface.

  19. Biosynthesis of silver nanoparticles

    African Journals Online (AJOL)

    SIMBU

    2013-05-22

    May 22, 2013 ... exposure to silver can cause agyrosis and argyria also; it is toxic to mammalian cells (Gong et al., 2007). The current investigation supports that use of silver ion or metallic silver as well as, silver nanoparticles can be exploited in medicine for burn treatment, dental materials, coating stainless steel materials, ...

  20. Silver deposition on stainless steel container surfaces in contact with disinfectant silver aqueous solutions

    Science.gov (United States)

    Petala, M.; Tsiridis, V.; Mintsouli, I.; Pliatsikas, N.; Spanos, Th.; Rebeyre, P.; Darakas, E.; Patsalas, P.; Vourlias, G.; Kostoglou, M.; Sotiropoulos, S.; Karapantsios, Th.

    2017-02-01

    Silver is the preservative used on the Russian segment of the International Space Station (ISS) to prevent microbial proliferation within potable water supplies. Yet, in the frame of the European Automated Transfer Vehicle (ATV) missions to ISS, silver depletion from water has been detected during ground transportation of this water to launch site, thereby indicating a degradation of water quality. This study investigates the silver loss from water when in contact with stainless steel surfaces. Experiments are conducted with several types of stainless steel surfaces being exposed to water containing 10 or 0.5 mg/L silver ions. Results show that silver deposits on stainless steel surfaces even when a passivation layer protects the metallic surface. The highest protection to silver deposition is offered by acid passivated and electropolished SS 316L. SEM and XPS experiments were carried out at several locations of the sample area that was in contact with the Ag solution and found similar morphological (SEM) and compositional (sputter-etch XPS) results. The results reveal that silver deposits uniformly across the wetted surface to a thickness larger than 3 nm. Moreover, evidence is provided that silver deposits in its metallic form on all stainless steel surfaces, in line with a galvanic deposition mechanism. Combination of ICP-MS and XPS results suggests a mechanism for Ag deposition/reduction with simultaneous substrate oxidation resulting in oxide growth at the exposed stainless steel surface.

  1. Childhood Trauma and Two Stages of Alcohol Use in African American and European American Women: Findings from a Female Twin Sample.

    Science.gov (United States)

    Sartor, Carolyn E; Grant, Julia D; Few, Lauren R; Werner, Kimberly B; McCutcheon, Vivia V; Duncan, Alexis E; Nelson, Elliot C; Madden, Pamela A F; Bucholz, Kathleen K; Heath, Andrew C; Agrawal, Arpana

    2017-09-05

    The current investigation assessed for moderating effects of childhood trauma on genetic and environmental contributions to timing of alcohol use initiation and alcohol use disorder in African American (AA) and European American (EA) women. Data were drawn from diagnostic telephone interviews conducted with 3786 participants (14.6% AA) in a longitudinal female twin study. Childhood trauma was defined alternately as child maltreatment and more broadly to include other events (e.g., witnessing violence). Phenotypic associations between childhood trauma and alcohol outcomes were estimated using logistic regression analyses. Twin modeling was conducted to test for moderating effects of childhood trauma on the contributions of genetic and environmental factors to timing of initiation and alcohol use disorder. Under both definitions, childhood trauma was associated with early initiation (relative risk ratios: 1.90, 1.72) and alcohol use disorder (odds ratios: 1.92, 1.76). Yet gene by environment effects were observed only for child maltreatment and timing of initiation in EA women, with heritable influences less prominent in those who had experienced child maltreatment (0.35, 95% CI: 0.05-0.66 vs. 0.52, 95% CI: 0.30-0.73). We found more similarities than differences in the association of childhood trauma with alcohol outcomes across racial/ethnic groups, trauma type, and stages of alcohol use. However, findings suggest that the relative contribution of genetic factors to alcohol outcomes differs by childhood maltreatment history in EA women specifically in the earliest stage of alcohol use.

  2. Relationship between Personality Traits and Nicotine Dependence in Male and Female Smokers of African-American and European-American Samples

    Directory of Open Access Journals (Sweden)

    Jung-Seok Choi

    2017-07-01

    Full Text Available AimsPersonality characteristics are linked to nicotine dependence (ND. It remains unclear whether these factors differ across African-American (AA and European-American (EA male and female smokers. This study was aimed to determine the relationship between personality traits and smoking status, as well as the degree of ND, in AA and EA male and female samples.MethodsA total of 5,040 participants (AA: N = 3,737, female = 54.31%; EA: N = 1,313, female = 64.51% were included in this study, with 2,474 smokers and 2,566 non-smokers. The measures used in this study included five dimensions of personality by the NEO-personality inventory-revised (neuroticism, extraversion, agreeableness, openness to experience, and conscientiousness, Fagerström test for ND, and drive subscale of the ND Syndrome Scale (NDSS.ResultsIn the AA sample, neuroticism was significantly associated with a higher risk of smoking [odds ratio (OR = 1.057; 95% confidence interval (CI 1.032, 1.083; p < 0.0001], and conscientiousness was significantly associated with decreased risk of smoking (OR = 0.936; 95% CI 0.912, 0.961; p < 0.0001. In the EA sample, higher neuroticism was associated with increased risk of being a current smoker (OR = 1.058; 95% CI 1.013, 1.104; p = 0.0105. Furthermore, we found that a lower level of neuroticism and higher level of conscientiousness were associated with the severity of ND in both the AA and EA samples and a broader range of personality factors were involved in predicting the severity of ND in the AA samples. However, no differential association was detected between male and female smokers of both AA and EA samples.ConclusionThere exist differential relationships between personality traits and the severity of ND in the AA and EA samples.

  3. The similar neurotoxic effects of nanoparticulate and ionic silver in vivo and in vitro

    DEFF Research Database (Denmark)

    Hadrup, Niels; Loeschner, Katrin; Mortensen, Alicja

    2012-01-01

    We compared the neurotoxic effects of 14nm silver nanoparticles (AgNPs) and ionic silver, in the form of silver acetate (AgAc), in vivo and in vitro. In female rats, we found that AgNPs (4.5 and 9mg AgNP/kg bw/day) and ionic silver (9mg Ag/kg bw/day) increased the dopamine concentration in the br...

  4. Are There Common Familial Influences for Major Depressive Disorder and an Overeating-Binge Eating Dimension in both European-American and African-American Female Twins?

    Science.gov (United States)

    Munn-Chernoff, Melissa A.; Grant, Julia D.; Agrawal, Arpana; Koren, Rachel; Glowinski, Anne L.; Bucholz, Kathleen K.; Madden, Pamela A. F.; Heath, Andrew C.; Duncan, Alexis E.

    2014-01-01

    Objective Although prior studies have demonstrated that depression is associated with an overeating-binge eating dimension (OE-BE), phenotypically, little research has investigated whether familial factors contribute to the co-occurrence of these phenotypes, especially in community samples with multiple racial/ethnic groups. We examined the extent to which familial (i.e., genetic and shared environmental) influences overlapped between Major Depressive Disorder (MDD) and OE-BE in a population-based sample and whether these influences were similar across racial/ethnic groups Method Participants included 3226 European-American (EA) and 550 African-American (AA) young adult women from the Missouri Adolescent Female Twin Study. An adaptation of the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA) was administered to assess lifetime DSM-IV MDD and OE-BE. Quantitative genetic modeling was used to estimate familial influences between both phenotypes; all models controlled for age. Results The best-fitting model, which combined racial/ethnic groups, found that additive genetic influences accounted for 44% (95% CI: 34%, 53%) of the MDD variance and 40% (25%, 54%) for OE-BE, with the remaining variances due to non-shared environmental influences. Genetic overlap was substantial (rg = .61 [.39, .85]); non-shared environmental influences on MDD and OE-BE overlapped weakly (re = .26 [.09, .42]) Discussion Results suggest that common familial influences underlie MDD and OE-BE, and the magnitude of familial influences contributing to the comorbidity between MDD and OE-BE is similar between EA and AA women. If racial/ethnic differences truly exist, then larger sample sizes may be needed to fully elucidate familial risk for comorbid MDD and OE-BE across these groups. PMID:24659561

  5. Are there common familial influences for major depressive disorder and an overeating-binge eating dimension in both European American and African American female twins?

    Science.gov (United States)

    Munn-Chernoff, Melissa A; Grant, Julia D; Agrawal, Arpana; Koren, Rachel; Glowinski, Anne L; Bucholz, Kathleen K; Madden, Pamela A F; Heath, Andrew C; Duncan, Alexis E

    2015-05-01

    Although prior studies have demonstrated that depression is associated with an overeating-binge eating dimension (OE-BE) phenotypically, little research has investigated whether familial factors contribute to the co-occurrence of these phenotypes, especially in community samples with multiple racial/ethnic groups. We examined the extent to which familial (i.e., genetic and shared environmental) influences overlapped between Major Depressive Disorder (MDD) and OE-BE in a population-based sample and whether these influences were similar across racial/ethnic groups. Participants included 3,226 European American (EA) and 550 African American (AA) young adult women from the Missouri Adolescent Female Twin Study. An adaptation of the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA) was administered to assess lifetime DSM-IV MDD and OE-BE. Quantitative genetic modeling was used to estimate familial influences between both phenotypes; all models controlled for age. The best-fitting model, which combined racial/ethnic groups, found that additive genetic influences accounted for 44% (95% CI: 34%, 53%) of the MDD variance and 40% (25%, 54%) for OE-BE, with the remaining variances due to non-shared environmental influences. Genetic overlap was substantial (rg  = .61 [.39, .85]); non-shared environmental influences on MDD and OE-BE overlapped weakly (re  = .26 [.09, .42]). Results suggest that common familial influences underlie MDD and OE-BE, and the magnitude of familial influences contributing to the comorbidity between MDD and OE-BE is similar between EA and AA women. If racial/ethnic differences truly exist, then larger sample sizes may be needed to fully elucidate familial risk for comorbid MDD and OE-BE across these groups. © 2014 Wiley Periodicals, Inc.

  6. Optimization of silver-dielectric-silver nanoshell for sensing applications

    Energy Technology Data Exchange (ETDEWEB)

    Shirzaditabar, Farzad; Saliminasab, Maryam [Department of Physics, Razi University, Kermanshah 67144-15111 (Iran, Islamic Republic of)

    2013-08-15

    In this paper, resonance light scattering (RLS) properties of a silver-dielectric-silver nanoshell, based on quasi-static approach and plasmon hybridization theory, are investigated. Scattering spectrum of silver-dielectric-silver nanoshell has two intense and clearly separated RLS peaks and provides a potential for biosensing based on surface plasmon resonance and surface-enhanced Raman scattering. The two RLS peaks in silver-dielectric-silver nanoshell are optimized by tuning the geometrical dimensions. In addition, the optimal geometry is discussed to obtain the high sensitivity of silver-dielectric-silver nanoshell. As the silver core radius increases, the sensitivity of silver-dielectric-silver nanoshell decreases whereas increasing the middle dielectric thickness increases the sensitivity of silver-dielectric-silver nanoshell.

  7. Comparative assessment of study groups of elderly female computer users from four European countries: Questionnaires used in the NEW-study

    NARCIS (Netherlands)

    Sandsjö, L.; Larsman, P.; Vollenbroek-Hutten, Miriam Marie Rosé; Läubli, T.; Juul-Kristensen, B.; Klipstein, A.; Hermens, Hermanus J.; Sogaard, K.

    There is a lack of consistent and comprehensive questionnaire forms for the studies of factors associated with work-related musculoskeletal disorders at the European level. One of the results of the EU-funded project, neuromuscular assessment in the elderly worker (NEW), is a set of questionnaires

  8. The silver ions contribution into the cytotoxic activity of silver and silver halides nanoparticles

    Science.gov (United States)

    Klimov, A. I.; Zherebin, P. M.; Gusev, A. A.; Kudrinskiy, A. A.; Krutyakov, Y. A.

    2015-11-01

    The biocidal action of silver nanoparticles capped with sodium citrate and silver halides nanoparticles capped with non-ionic surfactant polyoxyethylene(20)sorbitan monooleate (Tween 80®) against yeast cells Saccharomyces cerevisiae was compared to the effect produced by silver nitrate and studied through the measurement of cell loss and kinetics of K+ efflux from the cells. The cytotoxicity of the obtained colloids was strongly correlated with silver ion content in the dispersions. The results clearly indicated that silver and silver halides nanoparticles destroyed yeast cells through the intermediate producing of silver ions either by dissolving of salts or by oxidation of silver.

  9. Copper and silver halates

    CERN Document Server

    Woolley, EM; Salomon, M

    2013-01-01

    Copper and Silver Halates is the third in a series of four volumes on inorganic metal halates. This volume presents critical evaluations and compilations for halate solubilities of the Group II metals. The solubility data included in this volume are those for the five compounds, copper chlorate and iodate, and silver chlorate, bromate and iodate.

  10. Silver delafossite oxides.

    Science.gov (United States)

    Sheets, William C; Stampler, Evan S; Bertoni, Mariana I; Sasaki, Makoto; Marks, Tobin J; Mason, Thomas O; Poeppelmeier, Kenneth R

    2008-04-07

    A single-step, low-temperature (<210 degrees C) and -pressure (<20 atm) hydrothermal method has been developed to synthesize a series of silver delafossites, AgBO2 (B = Al, Ga, Sc, and In). Experimental and computational studies were performed to understand the optical and electric properties of these silver delafossites, including the first in-depth study of AgAlO2 and AgScO2. Their properties were examined as a function of the trivalent cation radius and compared to those of copper delafossites to elucidate the role of both the A- and B-site cations. While optical band gaps for silver delafossites were larger and visible light absorption was lower than values previously reported for polycrystalline powder samples of copper delafossites, the conductivities of silver delafossites are similar or lower. Electronic structure calculations indicate that these properties are due to the scarcity of silver 4d states just below the valence band maximum.

  11. Mineral commodity profiles: Silver

    Science.gov (United States)

    Butterman, W.C.; Hilliard, Henry E.

    2005-01-01

    Overview -- Silver is one of the eight precious, or noble, metals; the others are gold and the six platinum-group metals (PGM). World mine production in 2001 was 18,700 metric tons (t) and came from mines in 60 countries; the 10 leading producing countries accounted for 86 percent of the total. The largest producer was Mexico, followed by Peru, Australia, and the United States. About 25 percent of the silver mined in the world in 2001 came from silver ores; 15 percent, from gold ores and the remaining 60 percent, from copper, lead, and zinc ores. In the United States, 14 percent of the silver mined in 2001 came from silver ores; 39 percent, from gold ores; 10 percent, from copper and copper-molybdenum ores; and 37 percent, from lead, zinc, and lead-zinc ores. The precious metal ores (gold and silver) came from 30 lode mines and 10 placer mines; the base-metal ores (copper, lead, molybdenum, and zinc) came from 24 lode mines. Placer mines yielded less than 1 percent of the national silver production. Silver was mined in 12 States, of which Nevada was by far the largest producer; it accounted for nearly one-third of the national total. The production of silver at domestic mines generated employment for about 1,100 mine and mill workers. The value of mined domestic silver was estimated to be $290 million. Of the nearly 27,000 t of world silver that was fabricated in 2001, about one-third went into jewelry and silverware, one-fourth into the light-sensitive compounds used in photography, and nearly all the remainder went for industrial uses, of which there were 7 substantial uses and many other small-volume uses. By comparison, 85 percent of the silver used in the United States went to photography and industrial uses, 8 percent to jewelry and silverware, and 7 percent to coins and medals. The United States was the largest consumer of silver followed by India, Japan, and Italy; the 13 largest consuming countries accounted for nearly 90 percent of the world total. In the

  12. Annual Developmental Cycle of Gonads of European Perch Females (Perca fluviatilis L.) from Natural Sites and a Canal Carrying Post-cooling Water from the Dolna Odra Power Plant (NW Poland).

    Science.gov (United States)

    Kirczuk, Lucyna; Domagała, Józef; Pilecka-Rapacz, Małgorzata

    2015-01-01

    The European perch is a species endowed with high adaptation capabilities as regards different environmental conditions. The aim of the study was to analyse the annual developmental cycle of ovaries of the European perch from the Oder river, Lake Dąbie and a drainage canal (Warm Canal) carrying post-cooling water from the Dolna Odra power plant (annual average water temperature in the canal is higher by 6-8°C than the water of the other sampling sites). Most of the female perch caught in the canal carrying post-cooling water had immature stage 2 gonads (delayed development of the gonads) and were smaller than the fish from the other sites. No traces of spawning in the form of deposed egg strings were found in the drainage canal. Adult individuals avoid high temperatures found in the Warm Canal. In April, in perch from all sites, ovaries with post-spawning oocytes were observed. The spawning season of the females lasted from the beginning of April until May. Stage 4 of gonad development, with oocytes in advanced vitellogenesis, was the longest and ranged from September through February.

  13. Do female colleagues and supervisors influence family role attitudes? A three-level test of exposure explanations among employed men and women in 27 European countries

    NARCIS (Netherlands)

    Meuleman, R.; Kraaykamp, G.L.M.; Verbakel, C.M.C.

    2017-01-01

    This study examines the relationship between various aspects of female labor participation and people's family role attitudes. Following exposure theory, we expect that individuals may adopt more egalitarian family roles as they are more often exposed to employed women because it dispels negative

  14. Isotopic Ag–Cu–Pb record of silver circulation through 16th–18th century Spain

    Science.gov (United States)

    Desaulty, Anne-Marie; Telouk, Philippe; Albalat, Emmanuelle; Albarède, Francis

    2011-01-01

    Estimating global fluxes of precious metals is key to understanding early monetary systems. This work adds silver (Ag) to the metals (Pb and Cu) used so far to trace the provenance of coinage through variations in isotopic abundances. Silver, copper, and lead isotopes were measured in 91 coins from the East Mediterranean Antiquity and Roman world, medieval western Europe, 16th–18th century Spain, Mexico, and the Andes and show a great potential for provenance studies. Pre-1492 European silver can be distinguished from Mexican and Andean metal. European silver dominated Spanish coinage until Philip III, but had, 80 y later after the reign of Philip V, been flushed from the monetary mass and replaced by Mexican silver. PMID:21606351

  15. The response to selection for broad male response to female sex pheromone and its implications for divergence in close-range mating behavior in the European corn borer moth, Ostrinia nubilalis.

    Science.gov (United States)

    Droney, David C; Musto, Callie J; Mancuso, Katie; Roelofs, Wendell L; Linn, Charles E

    2012-12-01

    Coordinated sexual communication systems, seen in many species of moths, are hypothesized to be under strong stabilizing natural selection. Stabilized communication systems should be resistant to change, but there are examples of species/populations that show great diversification. A possible solution is that it is directional sexual selection on variation in male response that drives evolution. We tested a component of this model by asking whether 'rare' males (ca. 5 % of all males in a population) of the European corn borer moth (ECB), Ostrinia nubilalis, that respond to the sex pheromones of both ECB and a different Ostrinia species (O. furnacalis, the Asian corn borer, ACB), might play an important role in diversification. We specifically tested, via artificial selection, whether this broad male response has an evolvable genetic component. We increased the frequency of broad male response from 5 to 70 % in 19 generations, showing that broad-responding males could be important for the evolution of novel communication systems in ECB. We did not find a broader range of mating acceptance of broad males by females of the base population, however, suggesting that broad response would be unlikely to increase in frequency without the involvement of other factors. However, we found that ECB selection-line females accepted a broader range of courting males, including those of ACB, than did females of the base population. Thus, a genetic correlation exists between broad, long-range response to female sex pheromone and the breadth of female acceptance of males at close range. These results are discussed in the context of evolution of novel communication systems in Ostrinia.

  16. Human exposure to silver released from silver-modified activated carbon applied in the new type of jug filter systems.

    Science.gov (United States)

    Garboś, Sławomir; Swiecicka, Dorota

    2013-01-01

    A water filtered by jug filter system (JFS) can be applied for the preparation of food products, as well as it can be directly consumed as drinking water. In the European Union, in both above-mentioned cases the quality of water filtered using JFSs has to fulfill the requirements listed in Directive 98/83/EC. However, Directive 98/83/EC sets no parametric value for silver, JFSs are not regulated under this legislative act and additionally, silver-modified activated carbon (applied in such systems) has not been approved by European Food Safety Authority (EFSA). Therefore, the exposure to this metal should be assessed for all JFSs containing filtration cartridges with silver-modified activated carbon, present on the retail market. A comprehensive study was conducted in order to examine the effect ofJFSs (consisted of filtration oval-cartridges of the new type with silver-modified activated carbon) on the quality of filtered water regarding the released amounts of silver. Silver migration from such type of cartridges has not been examined before. The aim of work was the assessment of exposure to silver released into filtered water from silver-modified activated carbon applied in such types of FSs. Silver migration from six brands of JFSs (A-F) was investigated according to British Standard BS 8427:2004 using a validated inductively coupled plasma mass spectrometry method. . The average daily silver concentrations in the composite samples collected on six measurement days forA, B, C, D, E and F JFSs were in the ranges of: 3.95-18.1 microg/l, 4.6-21.7 microg/l, 0.41-8.7 microLg/l, 6.9-10.9 microg/l, 3.3-17.1 microg/1 and 10.1-20.8 pg/1l, respectively. The established grand mean concentrations of released silver from all six oval cartridges were in the range of 2.7-14.3 jg/1. The estimated Hazard Quotient (HQ) indices were in the range of 0.015-0.082 CONCLUSIONS:. The estimated HQ indices were significantly lower than 1 and therefore no long-term risk for human health

  17. Ultrastable silver nanoparticles.

    Science.gov (United States)

    Desireddy, Anil; Conn, Brian E; Guo, Jingshu; Yoon, Bokwon; Barnett, Robert N; Monahan, Bradley M; Kirschbaum, Kristin; Griffith, Wendell P; Whetten, Robert L; Landman, Uzi; Bigioni, Terry P

    2013-09-19

    Noble-metal nanoparticles have had a substantial impact across a diverse range of fields, including catalysis, sensing, photochemistry, optoelectronics, energy conversion and medicine. Although silver has very desirable physical properties, good relative abundance and low cost, gold nanoparticles have been widely favoured owing to their proved stability and ease of use. Unlike gold, silver is notorious for its susceptibility to oxidation (tarnishing), which has limited the development of important silver-based nanomaterials. Despite two decades of synthetic efforts, silver nanoparticles that are inert or have long-term stability remain unrealized. Here we report a simple synthetic protocol for producing ultrastable silver nanoparticles, yielding a single-sized molecular product in very large quantities with quantitative yield and without the need for size sorting. The stability, purity and yield are substantially better than those for other metal nanoparticles, including gold, owing to an effective stabilization mechanism. The particular size and stoichiometry of the product were found to be insensitive to variations in synthesis parameters. The chemical stability and structural, electronic and optical properties can be understood using first-principles electronic structure theory based on an experimental single-crystal X-ray structure. Although several structures have been determined for protected gold nanoclusters, none has been reported so far for silver nanoparticles. The total structure of a thiolate-protected silver nanocluster reported here uncovers the unique structure of the silver thiolate protecting layer, consisting of Ag2S5 capping structures. The outstanding stability of the nanoparticle is attributed to a closed-shell 18-electron configuration with a large energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital, an ultrastable 32-silver-atom excavated-dodecahedral core consisting of a hollow 12-silver

  18. Leaching of Silver from Silver-Impregnated Food Storage Containers

    Science.gov (United States)

    Hauri, James F.; Niece, Brian K.

    2011-01-01

    The use of silver in commercial products has proliferated in recent years owing to its antibacterial properties. Food containers impregnated with micro-sized silver promise long food life, but there is some concern because silver can leach out of the plastic and into the stored food. This laboratory experiment gives students the opportunity to…

  19. Genetics Home Reference: Silver syndrome

    Science.gov (United States)

    ... movement and sensations. Silver syndrome is a complex hereditary spastic paraplegia. The first sign of Silver syndrome is usually ... links) GeneReview: BSCL2-Related Neurologic Disorders/Seipinopathy GeneReview: Hereditary ... Paraplegia Foundation, Inc.: Treatments and Therapies ...

  20. Printing Silver Nanogrids on Glass

    Science.gov (United States)

    Sanders, Wesley C.; Valcarce, Ron; Iles, Peter; Smith, James S.; Glass, Gabe; Gomez, Jesus; Johnson, Glen; Johnston, Dan; Morham, Maclaine; Befus, Elliot; Oz, Aimee; Tomaraei, Mohammad

    2017-01-01

    This manuscript describes a laboratory experiment that provides students with an opportunity to create conductive silver nanogrids using polymeric templates. A microcontact-printed polyvinylpyrrolidone grid directs the citrate-induced reduction of silver ions for the fabrication of silver nanogrids on glass substrates. In addition to…

  1. Silver-palladium cathode

    Energy Technology Data Exchange (ETDEWEB)

    Poizot, Philippe [Laboratoire de Reactivite et Chimie des Solides, UMR CNRS 6007, Universite de Picardie Jules Verne, 33 rue Saint-Leu, 80039 Amiens Cedex (France); Simonet, Jacques, E-mail: jacques.simonet@univ-rennes1.f [Laboratoire MaCSE, UMR CNRS 6226, Universite de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex (France)

    2010-12-15

    The formation of silver-palladium electrodes is described. It mainly corresponds to the palladization of silver by means of treatment with palladium salts (nitrate and sulphate) in acidic media. Other ways may exist such as the modification of solid conductors like carbons by deposition of a silver-palladium alloy. By using those electrodes in polar aprotic solvents, the one-electron cleavage of carbon-halogen bonds of most alkyl iodides and bromides may yield free alkyl radicals. Coupling and cross-coupling reactions can easily be carried out at such electrodes. The present review aims at discussing the electro-catalytic process as well as providing an update on the state of the art on this new mode of scission regarding carbon-heteroatom bonds.

  2. Silver-Russell syndrome

    Directory of Open Access Journals (Sweden)

    Shohela Akhter

    2016-08-01

    Full Text Available Silver-Russell syndrome is clinically and genetically a heterogeneous disorder. In most of the cases, etiology is unknown, only in 10% cases defect in chromosome 7 is identified. It bas distinctive facial features and asymmetric limbs. Most predominant symptom is growth failure. A case of Silver-Russell syndrome reported here who presented with growth failure, hemihypertrophy ofleft side oftbe body, dysmorphic facial profile and difficulty in speech. Counseling was done with the parents regarding the etiology, progression and outcome of the disease.

  3. War silver coins

    Directory of Open Access Journals (Sweden)

    Pantelić Svetlana

    2016-01-01

    Full Text Available There were two issues of silver 50-para, 1- and 2-dinar coins minted in the Parisian minting house marked with the year 1915 and bearing the image of King Petar I Karadjordjevic. Minted during the I World War, these two issues of silver coins only differed in that the first one had the specified name of the engraver (Schwarte, whereas the second issue had the engraver's name left out. These coins were used as the official legal tender until 28 June 1931.

  4. Perspectives on Female Entrepreneurs

    DEFF Research Database (Denmark)

    Kuada, John Ernest; Janulevièienë, Rûta

    2003-01-01

    The aim of this paper is to compare the contents of the academic evidence and debate on female entrepreneurship in the West with the current stream of research and thinking in the Central and Eastern European Countries with a view to identifying similarities and differences in thoughts and findin...

  5. Antibacterial activity and toxicity of silver - nanosilver versus ionic silver

    Science.gov (United States)

    Kvitek, L.; Panacek, A.; Prucek, R.; Soukupova, J.; Vanickova, M.; Kolar, M.; Zboril, R.

    2011-07-01

    The in vitro study of antibacterial activity of silver nanoparticles (NPs), prepared via modified Tollens process, revealed high antibacterial activity even at very low concentrations around several units of mg/L. These concentrations are comparable with concentrations of ionic silver revealing same antibacterial effect. However, such low concentrations of silver NPs did not show acute cytotoxicity to mammalian cells - this occurs at concentrations higher than 60 mg/L of silver, while the cytotoxic level of ionic silver is much more lower (approx. 1 mg/L). Moreover, the silver NPs exhibit lower acute ecotoxicity against the eukaryotic organisms such as Paramecium caudatum, Monoraphidium sp. and D. melanogaster. The silver NPs are toxic to these organisms at the concentrations higher than 30 mg/L of silver. On contrary, ionic silver retains its cytoxicity and ecotoxicity even at the concentration equal to 1 mg/L. The performed experiments demonstrate significantly lower toxicity of silver NPs against the eukaryotic organisms than against the prokaryotic organisms.

  6. Antibacterial activity and toxicity of silver - nanosilver versus ionic silver

    Energy Technology Data Exchange (ETDEWEB)

    Kvitek, L; Panacek, A; Prucek, R; Soukupova, J; Vanickova, M; Zboril, R [Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University, 17. Listopadu 12, 77146 Olomouc (Czech Republic); Kolar, M, E-mail: ales.panacek@upol.cz [Department of Microbiology, Faculty of Medicine and Dentistry, Palacky University, Hnevotinska 3, 77520 Olomouc (Czech Republic)

    2011-07-06

    The in vitro study of antibacterial activity of silver nanoparticles (NPs), prepared via modified Tollens process, revealed high antibacterial activity even at very low concentrations around several units of mg/L. These concentrations are comparable with concentrations of ionic silver revealing same antibacterial effect. However, such low concentrations of silver NPs did not show acute cytotoxicity to mammalian cells - this occurs at concentrations higher than 60 mg/L of silver, while the cytotoxic level of ionic silver is much more lower (approx. 1 mg/L). Moreover, the silver NPs exhibit lower acute ecotoxicity against the eukaryotic organisms such as Paramecium caudatum, Monoraphidium sp. and D. melanogaster. The silver NPs are toxic to these organisms at the concentrations higher than 30 mg/L of silver. On contrary, ionic silver retains its cytoxicity and ecotoxicity even at the concentration equal to 1 mg/L. The performed experiments demonstrate significantly lower toxicity of silver NPs against the eukaryotic organisms than against the prokaryotic organisms.

  7. Interference of Steroidogenesis by Gold Nanorod Core/Silver Shell Nanostructures: Implications for Reproductive Toxicity of Silver Nanomaterials.

    Science.gov (United States)

    Jiang, Xiumei; Wang, Liming; Ji, Yinglu; Tang, Jinglong; Tian, Xin; Cao, Mingjing; Li, Jingxuan; Bi, Shuying; Wu, Xiaochun; Chen, Chunying; Yin, Jun-Jie

    2017-03-01

    As a widely used nanomaterial in daily life, silver nanomaterials may cause great concern to female reproductive system as they are found to penetrate the blood-placental barrier and gain access to the ovary. However, it is largely unknown about how silver nanomaterials influence ovarian physiology and functions such as hormone production. This study performs in vitro toxicology study of silver nanomaterials, focusing especially on cytotoxicity and steroidogenesis and explores their underlying mechanisms. This study exposes primary rat granulosa cells to gold nanorod core/silver shell nanostructures (Au@Ag NRs), and compares outcomes with cells exposed to gold nanorods. The Au@Ag NRs generate more reactive oxygen species and reduce mitochondrial membrane potential and less production of adenosine triphosphate. Au@Ag NRs promote steroidogenesis, including progesterone and estradiol, in a time- and dose-dependent manner. Chemical reactivity and transformation of Au@Ag NRs are then studied by electron spin resonance spectroscopy and X-ray absorption near edge structure, which analyze the generation of free radical and intracellular silver species. Results suggest that both particle-specific activity and intracellular silver ion release of Au@Ag NR contribute to the toxic response of granulosa cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. The gender gap in risk factor control: Effects of age and education on the control of cardiovascular risk factors in male and female coronary patients. The EUROASPIRE IV study by the European Society of Cardiology.

    Science.gov (United States)

    De Smedt, Delphine; De Bacquer, Dirk; De Sutter, Johan; Dallongeville, Jean; Gevaert, Sofie; De Backer, Guy; Bruthans, Jan; Kotseva, Kornelia; Reiner, Željko; Tokgözoğlu, Lale; Clays, Els

    2016-04-15

    The aim of this study was to investigate gender related differences in the management and risk factor control of patients with coronary heart disease (CHD), taking into account their age and educational level. Analyses are based on the EUROASPIRE IV (EUROpean Action on Secondary and Primary Prevention through Intervention to Reduce Events) survey. Males and females between 18 and 80years of age, hospitalized for a first or recurrent coronary event were included in the study. Data were available for 7998 patients of which 75.6% were males. Overall, females had a worse risk factor profile compared to males and were more likely to have 3 or more risk factors (29.5% vs. 34.9%; p<0.001) across all age groups. A significant gender by education interaction (p<0.05) and gender by age interaction effect (p<0.05) was found. Furthermore, males were more likely to have a LDL-cholesterol on target (OR=1.50[1.28-1.76]), a HbA1c on target (OR=1.33[1.07-1.64]), to be non-obese (OR=1.45[1.30-1.62]) and perform adequate physical activity (OR=1.71[1.46-2.00]). In contrast males were less likely to be non-smokers (OR=0.71[0.60-0.83]). Furthermore, males were less likely to have made a dietary change (OR=0.78[0.64-0.95]) or a smoking cessation attempt (OR=0.70[0.50-0.96]) and more likely to have received smoking cessation advice if they were smokers (OR=1.52[1.10-2.09]). Whereas gender differences in CHD treatment are limited, substantial differences were found regarding target achievement. The largest gender difference was seen in less educated and elderly patients. The gender gap declined with decreasing age and higher education. Copyright © 2016. Published by Elsevier Ireland Ltd.

  9. Bioaccumulation of persistent organic pollutants in female common dolphins (Delphinus delphis) and harbour porpoises (Phocoena phocoena) from western European seas: Geographical trends, causal factors and effects on reproduction and mortality

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, G.J. [School of Biological Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ (United Kingdom); Instituto Espanol de Oceanografia, Centro Oceanografico de Vigo, P.O. Box 1552, 36200, Vigo (Spain)], E-mail: g.j.pierce@abdn.ac.uk; Santos, M.B. [School of Biological Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ (United Kingdom); Instituto Espanol de Oceanografia, Centro Oceanografico de Vigo, P.O. Box 1552, 36200, Vigo (Spain); Murphy, S. [AFDC, Department of Zoology, Ecology and Plant Science, University College, National University of Ireland, Enterprise Centre, North Mall, Cork (Ireland); Sea Mammal Research Unit, Gatty Marine Laboratory, University of St. Andrews, St. Andrews, Fife KY16 8LB (United Kingdom); Learmonth, J.A. [School of Biological Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ (United Kingdom); Zuur, A.F. [Highland Statistics, 6 Laverock Road, Newburgh, Aberdeenshire AB41 6FN (United Kingdom); Rogan, E. [AFDC, Department of Zoology, Ecology and Plant Science, University College, National University of Ireland, Enterprise Centre, North Mall, Cork (Ireland); Bustamante, P.; Caurant, F. [Centre de Recherche sur les Ecosystemes Littoraux Anthropises, UMR 6217 CNRS-IFREMER-Universite de la Rochelle, 22 avenue Michel Crepeau, 17042 La Rochelle (France); Lahaye, V. [School of Biological Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ (United Kingdom); Centre de Recherche sur les Ecosystemes Littoraux Anthropises, UMR 6217 CNRS-IFREMER-Universite de la Rochelle, 22 avenue Michel Crepeau, 17042 La Rochelle (France); Ridoux, V. [Centre de Recherche sur les Ecosystemes Littoraux Anthropises, UMR 6217 CNRS-IFREMER-Universite de la Rochelle, 22 avenue Michel Crepeau, 17042 La Rochelle (France); Zegers, B.N.; Mets, A. [Royal Netherlands Institute for Sea Research (NIOZ), P.O. Box 59, 1790 AB Den Burg, Texel (Netherlands)] (and others)

    2008-05-15

    Concentrations of polychlorinated biphenyls (PCBs) in blubber of female common dolphins and harbour porpoises from the Atlantic coast of Europe were frequently above the threshold at which effects on reproduction could be expected, in 40% and 47% of cases respectively. This rose to 74% for porpoises from the southern North Sea. PCB concentrations were also high in southern North Sea fish. The average pregnancy rate recorded in porpoises (42%) in the study area was lower than in the western Atlantic but that in common dolphins (25%) was similar to that of the western Atlantic population. Porpoises that died from disease or parasitic infection had higher concentrations of persistent organic pollutants (POPs) than animals dying from other causes. Few of the common dolphins sampled had died from disease or parasitic infection. POP profiles in common dolphin blubber were related to individual feeding history while those in porpoises were more strongly related to condition. - High PCB levels were recorded in porpoises and common dolphins from European coasts.

  10. Estimation of cumulative aquatic exposure and risk due to silver: contribution of nano-functionalized plastics and textiles.

    Science.gov (United States)

    Blaser, Sabine A; Scheringer, Martin; Macleod, Matthew; Hungerbühler, Konrad

    2008-02-15

    Products with antimicrobial effect based on silver nanoparticles are increasingly used in Asia, North America and Europe. This study presents an analysis of risk to freshwater ecosystems from silver released from these nanoparticles incorporated into textiles and plastics. The analysis is presented in four stages; (i) silver mass flow analysis and estimation of emissions, (ii) assessment of the fate of silver in a river system and estimation of predicted environmental concentrations (PECs), (iii) critical evaluation of available toxicity data for environmentally relevant forms of silver and estimation of predicted no-effect concentrations (PNECs), and (iv) risk characterization. Our assessment is based on estimated silver use in the year 2010, focusing on the Rhine river as a case study. In 2010, biocidal plastics and textiles are predicted to account for up to 15% of the total silver released into water in the European Union. The majority of silver released into wastewater is incorporated into sewage sludge and may be spread on agricultural fields. The amount of silver reaching natural waters depends on the fraction of wastewater that is effectively treated. Modeled PECs in the Rhine river are in satisfactory agreement with monitoring data from other river systems. Because a complete characterization of the toxicity of environmentally relevant silver species is lacking, only a limited risk assessment is possible at this time. However, our study indicates that PEC/PNEC ratios greater than 1 cannot be ruled out for freshwater ecosystems, in particular sediments. No risk is predicted for microbial communities in sewage treatment plants.

  11. Nucleic acid nanomaterials: Silver-wired DNA

    Science.gov (United States)

    Auffinger, Pascal; Ennifar, Eric

    2017-10-01

    DNA double helical structures are supramolecular assemblies that are typically held together by classical Watson-Crick pairing. Now, nucleotide chelation of silver ions supports an extended silver-DNA hybrid duplex featuring an uninterrupted silver array.

  12. The disappearance of the European eel from the western Wadden Sea

    NARCIS (Netherlands)

    van der Meer, J.; van der Veer, H.W.; Witte, J.IJ.

    2011-01-01

    A cohort model for the European eel is presented, which enables the interpretation of observed catches of yellow eel and silver eel in the western Wadden Sea in terms of recruitment data of glasseel. The model builds on various assumptions on length-dependent mortality and silvering rates and on the

  13. Effect of silver nanoparticles and silver ions on growth and adaptive response mechanisms of Pseudomonas putida mt-2.

    Science.gov (United States)

    Hachicho, Nancy; Hoffmann, Philipp; Ahlert, Kristin; Heipieper, Hermann J

    2014-06-01

    The distribution and use of nanoparticles increased rapidly during the last years, while the knowledge about mode of action, ecological tolerance and biodegradability of these chemicals is still insufficient. The effect of silver nanoparticles (AgNP) and free silver ions (Ag(+) , AgNO3 ) on Pseudomonas putida mt-2 as one of the best described bacterial strains for stress response were investigated. The effective concentration (EC50) causing 50% growth inhibition for AgNP was about 250 mg L(-1) , whereas this was only 0.175 mg L(-1) for AgNO3 . However, when calculating the amount of free silver ions released from AgNP both tested compounds showed very similar results. Therefore, the antibacterial activity of AgNP can be explained and reduced, respectively, to the amount of silver ions released from the nanoparticles. Both tested compounds showed a strong activation of the unique membrane adaptive response of Pseudomonas strains, the cis-trans isomerization of unsaturated fatty acids, whereas another important adaptive response of these bacteria, changes in cell surface hydrophobicity, measured as water contact angle, was not activated. These results are important informations for the estimation of environmental tolerance of newly developed, active ingredients like silver nanoparticles. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  14. Orthodontic silver brazing alloys.

    Science.gov (United States)

    Brockhurst, P J; Pham, H L

    1989-10-01

    Orthodontic silver brazing alloys suffer from the presence of cadmium, excessive flow temperatures, and crevice corrosion on stainless steel. Seven alloys were examined. Two alloys contained cadmium. The lowest flow temperature observed was 629 degrees C for a cadmium alloy and 651 degrees C for two cadmium free alloys. Three alloys had corrosion resistance superior to the other solders. Addition of low melting temperature elements gallium and indium reduced flow temperature in some cases but produced brittleness in the brazing alloy.

  15. Biosynthesis of silver nanoparticles.

    Science.gov (United States)

    Poulose, Subin; Panda, Tapobrata; Nair, Praseetha P; Théodore, Thomas

    2014-02-01

    Metal nanoparticles have unique optical, electronic, and catalytic properties. There exist well-defined physical and chemical processes for their preparation. Those processes often yield small quantities of nanoparticles having undesired morphology, and involve high temperatures for the reaction and the use of hazardous chemicals. Relatively, the older technique of bioremediation of metals uses either microorganisms or their components for the production of nanoparticles. The nanoparticles obtained from bacteria, fungi, algae, plants and their components, etc. appear environment-friendly, as toxic chemicals are not used in the processes. In addition to this, the formation of nanoparticles takes place at almost normal temperature and pressure. Control of the shape and size of the nanoparticles is possible by appropriate selection of the pH and temperature. Three important steps are the bioconversion of Ag+ ions, conversion of desired crystals to nanoparticles, and nanoparticle stability. Generally, nanoparticles are characterized by the UV-visible spectroscopy and use of the electron microscope. Silver nanoparticles are used as antimicrobial agents and they possess antifungal, anti-inflammatory, and anti-angiogenic properties. This review highlights the biosynthesis of silver nanoparticles by various organisms, possible mechanisms of their synthesis, their characterization, and applications of silver nanoparticles.

  16. Incontri e riflessioni con studentesse universitarie in Europa / Rencontres et réflexions avec des étudiantes universitaires en Europe / Meetings and reflections with European female university students

    Directory of Open Access Journals (Sweden)

    Sette Raffaella

    2013-07-01

    Full Text Available Con riferimento alla ricerca europea “Gender-Based Violence, Stalking and Fear of Crime – Prevention and Intervention”, nell’articolo vengono messi a confronto alcuni dati ricavati dalla somministrazione di un questionario a studentesse di 34 università ubicate in Germania, Inghilterra, Italia, Polonia e Spagna. In particolare, ci si soffermerà su aspetti relativi alle difficoltà riscontrate nel riconoscere la violenza e al raccontarla ad altri e su caratteristiche dell’esperienza subìta.Infine, verrà focalizzata l’attenzione su alcune tematiche che si collegano all’identificazione di buone prassi per prevenire ed intervenire in casi di violenza di genere a danno di studentesse universitarie. RésuméEn référence à la recherche européenne “Gender-Based Violence, Stalking and Fear of Crime – Prevention and Intervention”, dans cet article, l’auteur analyse des données provenant d’un questionnaire soumis aux étudiantes de 34 universités situées en Allemagne, en Angleterre, en Italie, en Pologne et en Espagne. L’auteur se concentre tout particulièrement sur certains aspects liés aux difficultés rencontrées pour reconnaître la violence et pour la raconter aux autres, et sur certaines caractéristiques de l’expérience vécue. Enfin, l’auteur concentre son attention sur les bonnes pratiques à adopter pour prévenir la violence de genre infligée aux étudiantes universitaires et intervenir contre celle-ci.AbstractReferring to the European research “Gender-Based Violence, Stalking and Fear of Crime – Prevention and Intervention”, in this article the author will compare some data gathered from a questionnaire carried out among female students of 34 universities situated in Germany, England, Italy, Poland and Spain. In particular, the author will dwell on some aspects related to difficulties in recognizing violence, disclosing this experience, and on some characteristics of it.In conclusion, the

  17. Silver against Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Kirketerp-Møller, K.; Kristiansen, S.

    2007-01-01

    bacteria in both the planktonic and biofilm modes of growth. The action of silver on mature in vitro biofilms of Pseudomonas aeruginosa, a primary pathogen of chronic infected wounds, was investigated. The results show that silver is very effective against mature biofilms of P. aeruginosa...

  18. Corrosion protection for silver reflectors

    Science.gov (United States)

    Arendt, Paul N.; Scott, Marion L.

    1991-12-31

    A method of protecting silver reflectors from damage caused by contact with gaseous substances which are often present in the atmosphere and a silver reflector which is so protected. The inventive method comprises at least partially coating a reflector with a metal oxide such as aluminum oxide to a thickness of 15 .ANG. or less.

  19. Food and feeding habits of silver carp, Hypophthalmichthys molitrix (Val., 1844 in Gobindsagar Reservoir, India.

    Directory of Open Access Journals (Sweden)

    Hamid Reza Esmaeili

    2015-08-01

    Full Text Available Investigation on the food and feeding habits of silver carp in Gobindsgar reservoir indicated that the diet of silver carp was dominated by Cyclotella spp. (diatom followed by Chlorophyceae, Cyanophyceae, Crustacea, Dianophyceae and Rotifera. The size range of Cyclotella spp. varied between 5-25 µm indicating that silver carp is capable to collect the food particles smaller than distance between its gill rakers. Probably, excretion of mucus plays an important role in collecting such small particles. By applying Costello method, it was concluded that Cyclotella spp. is very important food item while the others are general food items in the diet of silver carp in this water body. Study of diet overlap index of different size groups revealed that the value of “D” varied between 0.461 (moderate to 0.972 (high, indicating that the diet of small size groups was significantly different from those of large size groups. The present observations indicated that the diet overlap index between female and male silver carp was very high (0.915, clearly indicating that the diet of male and females specimens did not differ significantly. Analysis of gut contents of silver carp indicated that zooplankton comprised only 7.7% by number and 19.3% by volume in the fore–gut contents of this fish, hence, silver carp can be considered as microphytoplankton feeder.

  20. European communion

    DEFF Research Database (Denmark)

    Manners, Ian James

    2013-01-01

    Political theory of European union, through an engagement between political concepts and theoretical understandings, provides a means of identifying the EU as a political object. It is argued that understanding the projects, processes and products of European union, based on ‘sharing’ or ‘communion......’, provides a better means of perceiving the EU as a political object rather than terms such as ‘integration’ or ‘co-operation’. The concept of ‘European communion’ is defined as the ‘subjective sharing of relationships’, understood as the extent to which individuals or groups believe themselves to be sharing...... relations (or not), and the consequences of these beliefs for European political projects, processes and products. By exploring European communion through an engagement with contemporary political theory, using very brief illustrations from the Treaty of Lisbon, the article also suggests that European...

  1. Oral toxicity of silver ions, silver nanoparticles and colloidal silver – a review

    DEFF Research Database (Denmark)

    Hadrup, Niels; Lam, Henrik Rye

    2014-01-01

    Orally administered silver has been described to be absorbed in a range of 0.4-18% in mammals with a human value of 18%. Based on findings in animals, silver seems to be distributed to all of the organs investigated, with the highest levels being observed in the intestine and stomach. In the skin......, silver induces a blue-grey discoloration termed argyria. Excretion occurs via the bile and urine. The following dose-dependent animal toxicity findings have been reported: death, weight loss, hypoactivity, altered neurotransmitter levels, altered liver enzymes, altered blood values, enlarged hearts...... and immunological effects. Substantial evidence exists suggesting that the effects induced by particulate silver are mediated via silver ions that are released from the particle surface. With the current data regarding toxicity and average human dietary exposure, a Margin of Safety calculation indicates at least...

  2. Stature of early Europeans.

    Science.gov (United States)

    Hermanussen, Michael

    2003-01-01

    The ancestors of modern Europeans arrived in Europe at least 40,000 years before present. Pre-glacial maximum Upper Palaeolithic males (before 16,000 BC) were tall and slim (mean height 179 cm, estimated average body weight 67 kg), while the females were comparably small and robust (mean height 158 cm, estimated average body weight 54 kg). Late Upper Palaeolithic males (8000-6600 BC) were of medium stature and robusticity (mean height 166 cm, estimated average body weight 62 kg). Stature further decreased to below 165 cm with estimated average body weight of 64 kg in Neolithic males of the Linear Band Pottery Culture, and to 150 cm with estimated average body weight of 49 kg in Neolithic females. The body stature of European males remained within the range of 165 to 170 cm up to the end of the 19th century.

  3. The Pituitary Gland of the European Eel Reveals Massive Expression of Genes Involved in the Melanocortin System

    Science.gov (United States)

    Ager-Wick, Eirill; Dirks, Ron P.; Burgerhout, Erik; Nourizadeh-Lillabadi, Rasoul; de Wijze, Daniëlle L.; Spaink, Herman P.; van den Thillart, Guido E. E. J. M.; Tsukamoto, Katsumi; Dufour, Sylvie; Weltzien, Finn-Arne; Henkel, Christiaan V.

    2013-01-01

    Hormones secreted from the pituitary gland regulate important processes such as development, growth and metabolism, reproduction, water balance, and body pigmentation. Synthesis and secretion of pituitary hormones are regulated by different factors from the hypothalamus, but also through feedback mechanisms from peripheral organs, and from the pituitary itself. In the European eel extensive attention has been directed towards understanding the different components of the brain-pituitary-gonad axis, but little is known about the regulation of upstream processes in the pituitary gland. In order to gain a broader mechanistic understanding of the eel pituitary gland, we have performed RNA-seq transcriptome profiling of the pituitary of prepubertal female silver eels. RNA-seq reads generated on the Illumina platform were mapped to the recently assembled European eel genome. The most abundant transcript in the eel pituitary codes for pro-opiomelanocortin, the precursor for hormones of the melanocortin system. Several genes putatively involved in downstream processing of pro-opiomelanocortin were manually annotated, and were found to be highly expressed, both by RNA-seq and by qPCR. The melanocortin system, which affects skin color, energy homeostasis and in other teleosts interacts with the reproductive system, has so far received limited attention in eels. However, since up to one third of the silver eel pituitary’s mRNA pool encodes pro-opiomelanocortin, our results indicate that control of the melanocortin system is a major function of the eel pituitary. PMID:24130881

  4. The pituitary gland of the European eel reveals massive expression of genes involved in the melanocortin system.

    Directory of Open Access Journals (Sweden)

    Eirill Ager-Wick

    Full Text Available Hormones secreted from the pituitary gland regulate important processes such as development, growth and metabolism, reproduction, water balance, and body pigmentation. Synthesis and secretion of pituitary hormones are regulated by different factors from the hypothalamus, but also through feedback mechanisms from peripheral organs, and from the pituitary itself. In the European eel extensive attention has been directed towards understanding the different components of the brain-pituitary-gonad axis, but little is known about the regulation of upstream processes in the pituitary gland. In order to gain a broader mechanistic understanding of the eel pituitary gland, we have performed RNA-seq transcriptome profiling of the pituitary of prepubertal female silver eels. RNA-seq reads generated on the Illumina platform were mapped to the recently assembled European eel genome. The most abundant transcript in the eel pituitary codes for pro-opiomelanocortin, the precursor for hormones of the melanocortin system. Several genes putatively involved in downstream processing of pro-opiomelanocortin were manually annotated, and were found to be highly expressed, both by RNA-seq and by qPCR. The melanocortin system, which affects skin color, energy homeostasis and in other teleosts interacts with the reproductive system, has so far received limited attention in eels. However, since up to one third of the silver eel pituitary's mRNA pool encodes pro-opiomelanocortin, our results indicate that control of the melanocortin system is a major function of the eel pituitary.

  5. Silver nanoparticle release from commercially available plastic food containers into food simulants

    Science.gov (United States)

    Mackevica, Aiga; Olsson, Mikael Emil; Hansen, Steffen Foss

    2016-01-01

    Silver nanoparticles (AgNPs) are currently being used in many different kinds of consumer products in order to take advantage of their antimicrobial properties. However, the potential migration of silver nanoparticles into food and subsequent consumer exposure has hardly been addressed. In the current study, we investigated four brands of commercially available plastic food storage containers and measured the total amount of silver, particle size and number concentration, and the migration rates into three different food simulants (Milli-Q grade water, 10 % ethanol, and 3 % acetic acid) for 10 days at 40 °C. The experimental setup was made according to the European Commission Directive (EU 10/2011) for articles intended to be in contact with food. The total amount of silver in plastic containers and migration solutions was quantified by ICP-MS analysis, and the size of the migrated particles was investigated by single particle ICP-MS and TEM-EDS. The total mass and median size of released particulate Ag were generally highest in 3 % acetic acid for three out of four food container brands. The total content of silver in the containers varied from 13 to 42 µg/g. The highest migration was observed in the 3 % acetic acid food simulant for all four brands of containers, with total silver release up to 3.1 ng/cm2 after 10 days. In conclusion, the experimental results show that silver has the potential of migrating into food, especially when in contact with more acidic substances.

  6. European Institutions?

    NARCIS (Netherlands)

    Meacham, Darian

    2016-01-01

    The aim of this article is to sketch a phenomenological theory of political institutions and to apply it to some objections and questions raised by Pierre Manent about the project of the European Union and more specifically the question of “European Construction”, i.e. what is the aim of the

  7. Selective Europeanization

    DEFF Research Database (Denmark)

    Hoch Jovanovic, Tamara; Lynggaard, Kennet

    2014-01-01

    political contexts at the European level. We further show how the “translation” of international norms to a domestic context has worked to reinforce the original institutional setup, dating back to the mid-1950s. The translation of European-level minority policy developed in the 1990s and 2000s works most...

  8. Silver nanoparticles in dentistry.

    Science.gov (United States)

    Noronha, Victor T; Paula, Amauri J; Durán, Gabriela; Galembeck, Andre; Cogo-Müller, Karina; Franz-Montan, Michelle; Durán, Nelson

    2017-10-01

    Silver nanoparticles (AgNPs) have been extensively studied for their antimicrobial properties, which provide an extensive applicability in dentistry. Because of this increasing interest in AgNPs, the objective of this paper was to review their use in nanocomposites; implant coatings; pre-formulation with antimicrobial activity against cariogenic pathogens, periodontal biofilm, fungal pathogens and endodontic bacteria; and other applications such as treatment of oral cancer and local anesthesia. Recent achievements in the study of the mechanism of action and the most important toxicological aspects are also presented. Systematic searches were carried out in Web of Science (ISI), Google, PubMed, SciFinder and EspaceNet databases with the keywords "silver nano* or AgNP*" and "dentist* or dental* or odontol*". A total of 155 peer-reviewed articles were reviewed. Most of them were published in the period of 2012-2017, demonstrating that this topic currently represents an important trend in dentistry research. In vitro studies reveal the excellent antimicrobial activity of AgNPs when associated with dental materials such as nanocomposites, acrylic resins, resin co-monomers, adhesives, intracanal medication, and implant coatings. Moreover, AgNPs were demonstrated to be interesting tools in the treatment of oral cancers due to their antitumor properties. The literature indicates that AgNPs are a promising system with important features such as antimicrobial, anti-inflammatory and antitumor activity, and a potential carrier in sustained drug delivery. However, there are some aspects of the mechanisms of action of AgNPs, and some important toxicological aspects arising from the use of this system that must be completely elucidated. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  9. European Whiteness?

    DEFF Research Database (Denmark)

    Blaagaard, Bolette

    2008-01-01

    Born out of the United States’ (U.S.) history of slavery and segregation and intertwined with gender studies and feminism, the field of critical whiteness studies does not fit easily into a European setting and the particular historical context that entails. In order for a field of European...... critical whiteness studies to emerge, its relation to the U.S. theoretical framework, as well as the particularities of the European context need to be taken into account.. The article makes a call for a multi-layered approach to take over from the identity politics so often employed in the fields of U...

  10. European Security

    DEFF Research Database (Denmark)

    Møller, Bjørn

    Theoretical chapters on "Security", "Organisations" and "Regions," Historical Chapters on "Europe and Its Distinguishing Features" and on "The United Nations," "NATO," "The CSCE/OSCE and the Council of Europe" and "The European Union"......Theoretical chapters on "Security", "Organisations" and "Regions," Historical Chapters on "Europe and Its Distinguishing Features" and on "The United Nations," "NATO," "The CSCE/OSCE and the Council of Europe" and "The European Union"...

  11. Seasonal changes in platform use by adult farmbred silver foxes (Vulpes vulpes

    Directory of Open Access Journals (Sweden)

    H. T. KORHONEN

    2008-12-01

    Full Text Available Seasonal changes in platform use (Wooden U-type platform, area 3090 cm2 were studied during one year in adult farmbred silver foxes (Vulpes vulpes by daytime scan sampling observations and 24-h video recordings. Platform use was found to be lowest during the coldest part of the year (winter, late autumn and highest in mid-summer (July. The seasonal pattern in platform use obtained by the scan samplings was in agreement with that obtained by video recordings. Platform use was sex-related being significantly (p < 0.001 higher in females than males. Circadian distribution of platform use was rather similar for both sexes. Hourly use was highest from 4 to 5 a.m. and lowest at about 8-9 a.m. when farm work started. Platforms were mostly used for sleeping and the least for jumping. The animals' needs for rest, observation and seclusion required by the European Convention were met fairly well by the presently studied platform type. This is demonstrated by of its rather high amount of general use, and because it functioned appropriately as a place for observation and rest. Based on the present data, wooden U-type platforms can be recommended for practical farming purposes, particularly outside the winter period. ;

  12. Biosynthesis of silver nanoparticles | Silambarasan | African Journal ...

    African Journals Online (AJOL)

    friendly and exciting approach. Several microorganisms have been known to produce silver nanoparticles (Ag NPs), when silver molecules are exposed either intracellularly or extracellularly. Intracellular synthesis may accomplish a better ...

  13. Silver recovery from spent photographic solutions

    Energy Technology Data Exchange (ETDEWEB)

    Kunda, W.; Etsell, T.H.

    1991-04-12

    A process is disclosed for recovering silver sulfide from a silver-containing spent photographic fixer solution. The process is particularly suited for treating the fixer solution in a manner which enables recycling of the solution, and does not have the inefficiencies and high costs of alternative processes such as electrolysis. The process comprises introducing hydrosulfide ion into the silver-containing spent fixer solution to precipitate silver sulfide. The resultant precipitate is isolated from the fixer solution in order to remove silver from the solution. The process is especially suited for treating spent solutions which contain thiosulfate, in particular sodium or ammonium thiosulfate. The preferred hydrosulfide is either a sodium or ammonium hydrosulfide for precipitating silver in the form of silver sulfide. The quantity of hydrosulfide used is in the range of greater than 0.5 mole per mole of silver in the fixer solution. Experiments are described to illustrate the process of the invention. 3 figs., 5 tabs.

  14. Thermally induced morphological transition of silver fractals

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Solov'yov, Andrey; Kébaili, Nouari

    2014-01-01

    We present both experimental and theoretical study of thermally induced morphological transition of silver nanofractals. Experimentally, those nanofractals formed from deposition and diffusion of preformed silver clusters on cleaved graphite surfaces exhibit dendritic morphologies that are highly...

  15. European visit

    CERN Multimedia

    2006-01-01

    The European Commissioner for Science and Research, Janez Potočnik, (on the right) visited the CMS assembly hall accompanied by Jim Virdee, Deputy Spokesman of CMS (on the left), and Robert Aymar, Director-General of CERN. The European Commissioner for Science and Research, Janez Potočnik, visited CERN on Tuesday 31 January. He was welcomed by the Director-General, Robert Aymar, who described the missions and current activities of CERN to him, in particular the realisation of the LHC with its three components: accelerator, detectors, storage and processing of data. The European Commissioner then visited the CMS assembly hall, then the hall for testing the LHC magnets and the ATLAS cavern. During this first visit since his appointment at the end of 2004, Janez Potočnik appeared very interested by the operation of CERN, an example of successful scientific co-operation on a European scale. The many projects (30 on average) that CERN and the European Commission carry out jointly for the benefit of res...

  16. Silver and Chan revisited

    Science.gov (United States)

    Walsh, E.; Arnold, R.; Savage, M. K.

    2013-10-01

    Seismic shear waves emitted by earthquakes can be modeled as plane (transverse) waves. When entering an anisotropic medium, they can be split into two orthogonal components moving at different speeds. This splitting occurs along an axis, the fast polarization, that is determined by geologic conditions. We present here a comprehensive analysis of the Silver and Chan (1991) method, used to obtain shear wave splitting parameters, comprising theoretical derivations and statistical tests of the assumptions used to construct the standard errors. We find discrepancies in the derivations of equations in their article, with the most important being a mistake in how the standard errors are calculated. Our simulations suggest that the degrees of freedom are being overestimated by this method, and consequently, the standard errors are too small. Using a set of S waveforms from very similar shallow earthquakes on Reunion Island, we perform a statistical analysis on the noise of these replicates and find that the assumption of Gaussian noise does not hold. Further, the properties of background noise differ substantially from the noise obtained from the shear wave splitting analysis. However, we find that the estimated standard errors for the fast polarization are comparable to the spread in the fast polarization parameters between events. Delay time errors appear to be comparable to delay time estimates once cycle skipping is accounted for. Future work using synthetic seismograms with simulated noise should be conducted to confirm this is the case for earthquakes in general.

  17. The Mode of Action of Silver and Silver Halides Nanoparticles against Saccharomyces cerevisiae Cells

    Directory of Open Access Journals (Sweden)

    A. A. Kudrinskiy

    2014-01-01

    Full Text Available Silver and silver halides nanoparticles (NPs (Ag, AgCl, AgBr, and AgI capped with two different stabilizers (sodium citrate and nonionic surfactant Tween 80 were obtained via sodium borohydride reduction of silver nitrate in an aqueous solution. The effect of the biocidal action of as-prepared synthesized materials against yeast cells Saccharomyces cerevisiae was compared to the effect produced by silver nitrate and studied through the measurement of cell loss and kinetics of K+ efflux from the cells depending on concentration of silver. The results clearly indicate that the silver ions either remained in the dispersion of silver NPs and silver halides NPs after their synthesis or were generated afterwards by dissolving silver and silver halides particles playing a major part in the cytotoxic activity of NPs against yeast cells. It was also supposed that this activity most likely does not relate to the damage of cell membrane.

  18. Female Condom

    Science.gov (United States)

    ... P080002. Accessed Nov. 13, 2014. Female condom About Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  19. Physiological response to acute silver exposure in the freshwater crayfish (Cambarus diogenes diogenes) - a model invertebrate?

    DEFF Research Database (Denmark)

    Grosell, Martin Hautopp; Brauner, C.J.; Kelly, S.P.

    2002-01-01

    Crayfish, Silver toxicity, Osmoregulatory disturbance, Silver accumulation, Unidirectional Na+ flux......Crayfish, Silver toxicity, Osmoregulatory disturbance, Silver accumulation, Unidirectional Na+ flux...

  20. Topical silver for treating infected wounds

    NARCIS (Netherlands)

    Vermeulen, H.; van Hattem, J. M.; Storm-Versloot, M. N.; Ubbink, D. T.

    2007-01-01

    BACKGROUND: Topical silver treatments and silver dressings are increasingly used for the local treatment of contaminated or infected wounds, however, there is a lack of clarity regarding the evidence for their effectiveness. OBJECTIVES: To evaluate the effects on wound healing of topical silver and

  1. Geometrical parameters effects on local electric field enhancement of silver-dielectric-silver multilayer nanoshell

    Energy Technology Data Exchange (ETDEWEB)

    Shirzaditabar, Farzad; Saliminasab, Maryam [Department of Physics, Razi University, Kermanshah 67144-15111 (Iran, Islamic Republic of)

    2013-05-15

    The local electric field enhancement at different points of silver-dielectric-silver nanoshell is investigated using quasi-static theory. Because of the symmetric and anti-symmetric coupling between surface plasmon of inner silver core and outer silver shell, the local electric field spectrum of silver-dielectric-silver has two distinct peaks at resonance wavelengths. The silver core size and middle dielectric thickness affect the local electric field enhancement at different points of silver-dielectric-silver nanoshell. Increasing the silver core radius always leads to blue shift of shorter resonance wavelength and red shift of longer resonance wavelength. We observed two distinct local electric field peaks, which are corresponded to the symmetric and anti-symmetric coupling between inner and outer surface plasmons. In a system with thick silver shell, local electric field enhancement is greater than a system with thin silver shell. However, the local electric field variations as a function of silver core radius in both systems are different at different points of nanoshell. The effects of the dielectric thickness variations on local electric field are different from those from silver core size variations. As the dielectric thickness is about 3 nm, the highest local electric field enhancement occurs at the surface of the inner silver core, where the symmetric and anti-symmetric modes are mixed together.

  2. Movement symmetry and asymmetry of goal shots in female football ...

    African Journals Online (AJOL)

    This study examined the phenomenon of symmetrical skills in goal shot technique in female football players, of nine video recorded matches. The recording was taken during the 2nd Under 19 female football World Cup in 2004 and the 6th European female Championships of female seniors in 2005. The study comprised ...

  3. European Cinema

    NARCIS (Netherlands)

    Elsaesser, Thomas

    2005-01-01

    In the face of renewed competition from Hollywood since the early 1980s and the challenges posed to Europe's national cinemas by the fall of the Wall in 1989, independent filmmaking in Europe has begun to re-invent itself. European Cinema: Face to Face with Hollywood re-assesses the different

  4. Antituberculous effect of silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kreytsberg, G N; Gracheva, I E [Limited Liability Company ' Scientific and Production Association (NPO)' Likom' , 150049, Yaroslavl, Magistralnaya str., 32 (Russian Federation); Kibrik, B S [Yaroslavl State Medical Academy Russia, 150000, Yaroslavl, Revolutsionnaya str., 5 (Russian Federation); Golikov, I V, E-mail: likomm@yaroslavl.ru [Yaroslavl State Technical University Russia, 150023, Yaroslavl, Moskovskiy avenue, 88 (Russian Federation)

    2011-04-01

    The in vitro experiment, involving 1164 strains of the tuberculosis mycobacteria, exhibited a potentiating effect of silver nanoparticles on known antituberculous preparations in respect of overcoming drug-resistance of the causative agent. The in vitro experiment, based on the model of resistant tuberculosis, was performed on 65 white mice. An evident antituberculous effect of the nanocomposite on the basis of silver nanoparticles and isoniazid was proved. Toxicological assessment of the of nanopreparations was carried out. The performed research scientifically establishes efficacy and safety of the nanocomposite application in combination therapy of patients suffering from drug-resistant tuberculosis.

  5. Silver nitrate cauterization: a treatment option for aphthous stomatitis.

    Science.gov (United States)

    Soylu Özler, Gül

    2014-07-01

    In this study we compared silver nitrate cautery with placebo to assess the effect of silver nitrate cautery in aphthous stomatitis for pain relief and healing time. In this study, sixty-five patients with aphthous stomatitis were assessed. Silver nitrate sticks were used in group A (treatment group) and placebo sticks were used for group B (control group). Change in the severity of pain, change in the size of the ulcers, healing time, side effects of the procedure were assessed. Although the mean value of pain scores before the procedure was similar in both of the groups, there were statistically significant differences between two groups after the procedure on the first to the seventh day. On the seventh day after the procedure, the ulcers were completely reepithelialized in 21 patients (60%) in the treatment group and in 10 patients (32%) in the placebo group. The difference was statistically significant (p aphthous stomatitis. Also this treatment shortens the healing time of ulcers. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  6. Papillomatosis in a European bison.

    Science.gov (United States)

    Literák, I; Tomita, Y; Ogawa, T; Shirasawa, H; Smíd, B; Novotny, L; Adamec, M

    2006-01-01

    Five European bison (Bison bonasus) from three European zoos were shipped to the Bukovské Vrchy Hills (Slovakia) in June 2004 and kept together in an acclimatization enclosure. The European bison were released into the wild in December 2004. At that time, papillomas were found at the medial canthus of the left eye of a 12-yr-old female bison. Cutaneous papillomatosis was confirmed histologically. Negative stain transmission electron microscopic examination revealed papillomavirus in the papillomas, and papillomavirus DNA also was detected using the polymerase chain reaction with FAP59 and FAP64 primers. The amplified 413 bp DNA sequence was identical to that of BAPV2 bovine papillomavirus. This paper is the first report of papillomatosis in European bison.

  7. The Dynamics of Female Employment around Childbirth

    NARCIS (Netherlands)

    Vlasblom, J.D.; Schippers, J.J.

    2003-01-01

    There is a strong effect of childbirth on female labour supply. This effect is expected to be influenced, among others, by the institutional context. This paper uses panel data on the last two decades on three European countries (The Netherlands, Germany, United Kingdom) to link changes in female

  8. Silver-Palladium Surfaces Inhibit Biofilm Formation

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Schroll, Casper; Hilbert, Lisbeth Rischel

    2009-01-01

    Undesired biofilm formation is a major concern in many areas. In the present study, we investigated biofilm-inhibiting properties of a silver-palladium surface that kills bacteria by generating microelectric fields and electrochemical redox processes. For evaluation of the biofilm inhibition...... efficacy and study of the biofilm inhibition mechanism, the silver-sensitive Escherichia coli J53 and the silver-resistant E. coli J53[pMG101] strains were used as model organisms, and batch and flow chamber setups were used as model systems. In the case of the silver-sensitive strain, the silver......-palladium surfaces killed the bacteria and prevented biofilm formation under conditions of low or high bacterial load. In the case of the silver-resistant strain, the silver-palladium surfaces killed surface-associated bacteria and prevented biofilm formation under conditions of low bacterial load, whereas under...

  9. Toxicogenomic study in rat thymus of F1 generation offspring following maternal exposure to silver ion

    Directory of Open Access Journals (Sweden)

    Xiugong Gao

    2015-01-01

    Full Text Available Male and female rats (26-day-old were exposed to 0.0, 0.4, 4 or 40 mg/kg body weight silver acetate (AgAc in drinking water for 10 weeks prior to and during mating. Sperm-positive females remained within their dose groups and were exposed to silver acetate during gestation and lactation. At postnatal day 26, the effect of silver ions on the developing F1 generation rat thymus was evaluated at the transcriptional level using whole-genome microarrays. Gene expression profiling analyses identified a dozen differentially expressed genes (DEGs in each dose group using a loose criterion of fold change (FC >1.5 and unadjusted p < 0.05, regardless of whether the analysis was conducted within each gender group or with both gender groups combined. No dose-dependent effect was observed on the number of DEGs. In addition, none of these genes had a false discovery rate (FDR <0.05 after correction for multiple testing. These results in combination with the observation that thymus-to-body-weight ratios were not affected and no histopathological abnormalities were identified indicate that in utero exposure to silver ions up to 26.0 mg/kg (equivalent to 40.0 mg/kg silver acetate did not have an adverse effect on the developing thymus.

  10. Plasmonic characterization of photo-induced silver nanoparticles extracted from silver halide based TEM film

    Energy Technology Data Exchange (ETDEWEB)

    Sudheer,, E-mail: sudheer@rrcat.gov.in; Tiwari, P.; Rai, V. N.; Srivastava, A. K. [Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology Indore, Madhya Pradesh 452013 (India); Varshney, G. K. [Laser Bio-medical Applications & Instrumentation Division, Raja Ramanna Centre for Advanced Technology Indore, Madhya Pradesh 452013 (India)

    2016-05-23

    The plasmonic responses of silver nanoparticles extracted from silver halide based electron microscope film are investigated. Photo-reduction process is carried out to convert the silver halide grains into the metallic silver. The centrifuge technique is used for separating the silver nanoparticles from the residual solution. Morphological study performed by field emission scanning electron microscope (FESEM) shows that all the nanoparticles have an average diameter of ~120 nm with a high degree of mono dispersion in size. The localized surface plasmon resonance (LSPR) absorption peak at ~537 nm confirms the presence of large size silver nanoparticles.

  11. Differential Effects of Silver Nanoparticles and Silver Ions on Tissue Accumulation, Distribution, and Toxicity in the Sprague Dawley Rat Following Daily Oral Gavage Administration for 13 Weeks.

    Science.gov (United States)

    Boudreau, Mary D; Imam, Mohammed S; Paredes, Angel M; Bryant, Matthew S; Cunningham, Candice K; Felton, Robert P; Jones, Margie Y; Davis, Kelly J; Olson, Greg R

    2016-03-01

    There are concerns within the regulatory and research communities regarding the health impact associated with consumer exposure to silver nanoparticles (AgNPs). This study evaluated particulate and ionic forms of silver and particle size for differences in silver accumulation, distribution, morphology, and toxicity when administered daily by oral gavage to Sprague Dawley rats for 13 weeks. Test materials and dose formulations were characterized by transmission electron microscopy (TEM), dynamic light scattering, and inductively coupled mass spectrometry (ICP-MS). Seven-week-old rats (10 rats per sex per group) were randomly assigned to treatments: AgNP (10, 75, and 110 nm) at 9, 18, and 36 mg/kg body weight (bw); silver acetate (AgOAc) at 100, 200, and 400 mg/kg bw; and controls (2 mM sodium citrate (CIT) or water). At termination, complete necropsies were conducted, histopathology, hematology, serum chemistry, micronuclei, and reproductive system analyses were performed, and silver accumulations and distributions were determined. Rats exposed to AgNP did not show significant changes in body weights or intakes of feed and water relative to controls, and blood, reproductive system, and genetic tests were similar to controls. Differences in the distributional pattern and morphology of silver deposits were observed by TEM: AgNP appeared predominantly within cells, while AgOAc had an affinity for extracellular membranes. Significant dose-dependent and AgNP size-dependent accumulations were detected in tissues by ICP-MS. In addition, sex differences in silver accumulations were noted for a number of tissues and organs, with accumulations being significantly higher in female rats, especially in the kidney, liver, jejunum, and colon. Published by Oxford University Press on behalf of the Society of Toxicology 2016. This work is written by US Government employees and is in the public domain in the US.

  12. Female Genital Cutting

    Science.gov (United States)

    ... Z Health Topics Female genital cutting Female genital cutting > A-Z Health Topics Female genital cutting fact ... Publications email updates Enter email Submit Female genital cutting Female genital cutting (FGC), sometimes called female circumcision ...

  13. Female aging

    Directory of Open Access Journals (Sweden)

    Isabel Cristina Esposito Sorpreso

    2015-12-01

    Full Text Available SUMMARY Female aging is a process that involves hypoestrogenism time, the individual impact on each woman, and what we can do as experts to reduce morbidity and provide quality of life. This natural process in the female life cycle has been of concern to women after menopause. Changes in different biophysical and psychosocial aspects, and their individual experiences, have repercussions on the lives of patients seeking specialized and multidisciplinary support to reduce the harmful effects of prolonged hypoestrogenism. Overweight and obesity, inadequate living habits and the presence of multi-morbidities cause damage to the quality of life and impact the functional capacity. Behavioral prescription and hormone therapy are among the treatments given to ease symptoms and reduce morbidity. A better understanding of these factors can help identify groups that require more care after menopause.

  14. Female sexuality

    Science.gov (United States)

    Rao, T.S. Sathyanarana; Nagaraj, Anil Kumar M.

    2015-01-01

    Sex is a motive force bringing a man and a woman into intimate contact. Sexuality is a central aspect of being human throughout life and encompasses sex, gender identities and roles, sexual orientation, eroticism, pleasure, intimacy, and reproduction. Sexuality is experienced and expressed in thoughts, fantasies, desires, beliefs, attitudes, values, behaviors, practices, roles and relationships. Though generally, women are sexually active during adolescence, they reach their peak orgasmic frequency in their 30 s, and have a constant level of sexual capacity up to the age of 55 with little evidence that aging affects it in later life. Desire, arousal, and orgasm are the three principle stages of the sexual response cycle. Each stage is associated with unique physiological changes. Females are commonly affected by various disorders in relation to this sexual response cycle. The prevalence is generally as high as 35–40%. There are a wide range of etiological factors like age, relationship with a partner, psychiatric and medical disorders, psychotropic and other medication. Counseling to overcome stigma and enhance awareness on sexuality is an essential step in management. There are several effective psychological and pharmacological therapeutic approaches to treat female sexual disorders. This article is a review of female sexuality. PMID:26330647

  15. Female sexuality.

    Science.gov (United States)

    Rao, T S Sathyanarana; Nagaraj, Anil Kumar M

    2015-07-01

    Sex is a motive force bringing a man and a woman into intimate contact. Sexuality is a central aspect of being human throughout life and encompasses sex, gender identities and roles, sexual orientation, eroticism, pleasure, intimacy, and reproduction. Sexuality is experienced and expressed in thoughts, fantasies, desires, beliefs, attitudes, values, behaviors, practices, roles and relationships. Though generally, women are sexually active during adolescence, they reach their peak orgasmic frequency in their 30 s, and have a constant level of sexual capacity up to the age of 55 with little evidence that aging affects it in later life. Desire, arousal, and orgasm are the three principle stages of the sexual response cycle. Each stage is associated with unique physiological changes. Females are commonly affected by various disorders in relation to this sexual response cycle. The prevalence is generally as high as 35-40%. There are a wide range of etiological factors like age, relationship with a partner, psychiatric and medical disorders, psychotropic and other medication. Counseling to overcome stigma and enhance awareness on sexuality is an essential step in management. There are several effective psychological and pharmacological therapeutic approaches to treat female sexual disorders. This article is a review of female sexuality.

  16. Distribution of silver in rats following 28 days of repeated oral exposure to silver nanoparticles or silver acetate

    DEFF Research Database (Denmark)

    Löschner, Katrin; Hadrup, Niels; Qvortrup, Klaus

    2011-01-01

    Background: The study investigated the distribution of silver after 28 days repeated oral administration of silver nanoparticles (AgNPs) and silver acetate (AgAc) to rats. Oral administration is a relevant route of exposure because of the use of silver nanoparticles in products related to food...... and food contact materials. Results: AgNPs were synthesized with a size distribution of 14 ± 4 nm in diameter (90% of the nanoparticle volume) and stabilized in aqueous suspension by the polymer polyvinylpyrrolidone (PVP). The AgNPs remained stable throughout the duration of the 28-day oral toxicity study...... in rats. The organ distribution pattern of silver following administration of AgNPs and AgAc was similar. However the absolute silver concentrations in tissues were lower following oral exposure to AgNPs. This was in agreement with an indication of a higher fecal excretion following administration of Ag...

  17. Celioscopic liver biopsy in silver catfish (Rhamdia quelen

    Directory of Open Access Journals (Sweden)

    João P.S. Feranti

    2015-01-01

    Full Text Available Endosurgery has been used for assessment of fish celomatic cavity, as well as for obtaining biopsies for organic analysis. Such minimally invasive access may also be used for the analysis of environmental impact on biomarkers of pollution. In Brazil, studies and literature regarding the use of celioscopy in fish are sparse. The purpose of the current study was to develop a two-port celioscopy technique to obtain liver biopsy in silver catfish (Rhamdia quelen. Six adult female silver catfish were used. The animals were anesthetized and the inspection of the celomatic cavity were performed using a telescope and celioscopic-guided liver biopsy were taken using laparoscopic Kelly forceps. On the early postoperative period, the animals were released in a confined water reservoir where mortality could be checked. The liver samples were sent for histological assessment. There were no complications during surgery on early postoperative period. It was possible to visualize meticulously several organs (liver, spleen, stomach, pancreas, swim bladder, ovaries, bowel and transverse septum. In conclusion, the surgical technique and the anesthetic protocol proposed were suitable to perform liver biopsies in silver catfish and provided low morbidity.

  18. Silver nanoparticle release from commercially available plastic food containers into food simulants

    Energy Technology Data Exchange (ETDEWEB)

    Mackevica, Aiga, E-mail: aima@env.dtu.dk; Olsson, Mikael Emil; Hansen, Steffen Foss [Technical University of Denmark, Department of Environmental Engineering (Denmark)

    2016-01-15

    Silver nanoparticles (AgNPs) are currently being used in many different kinds of consumer products in order to take advantage of their antimicrobial properties. However, the potential migration of silver nanoparticles into food and subsequent consumer exposure has hardly been addressed. In the current study, we investigated four brands of commercially available plastic food storage containers and measured the total amount of silver, particle size and number concentration, and the migration rates into three different food simulants (Milli-Q grade water, 10 % ethanol, and 3 % acetic acid) for 10 days at 40 °C. The experimental setup was made according to the European Commission Directive (EU 10/2011) for articles intended to be in contact with food. The total amount of silver in plastic containers and migration solutions was quantified by ICP-MS analysis, and the size of the migrated particles was investigated by single particle ICP-MS and TEM-EDS. The total mass and median size of released particulate Ag were generally highest in 3 % acetic acid for three out of four food container brands. The total content of silver in the containers varied from 13 to 42 µg/g. The highest migration was observed in the 3 % acetic acid food simulant for all four brands of containers, with total silver release up to 3.1 ng/cm{sup 2} after 10 days. In conclusion, the experimental results show that silver has the potential of migrating into food, especially when in contact with more acidic substances.

  19. Pyrethroid toxicity in silver catfish, Rhamdia quelen

    Directory of Open Access Journals (Sweden)

    Francisco P. Montanha

    2012-12-01

    Full Text Available This study aimed to determine both the lethal and sublethal concentrations of Cypermethrin in young Silver Catfish (Brazilian "Jundiá", Rhamdia quelen on aquatic environment during 96 hours, as well as to determine the Cypermethrin and Deltamethrin sublethal concentrations during the initial embryonic development period of Rhamdia quelen, and to verify their respective rates of fertilization, hatching and survival. Pyrethroid nowadays is a widely used insecticide, which presents a high toxicity to fish. In order to determine lethal and sublethal concentrations, 120 silver catfish were used; each one had an average weight of 59.58±4.50g and an average size of 20.33±2.34cm. Concentrations used were 0, 1.0, 1.5, 2.0, 2.5, 3.0, 5.0, 10.0, 15.0 and 20.0mg of Cypermethrin per liter of water (mg/L. Fish were exposed to the product in 30-liter fish tanks. In each fish tank there were four fishes and the product was applied three times, i.e., a total of twelve fish were exposed to the product at each application, and a total of 120 fish during the entire experiment (n=120. In order to determine the Cypermethrin and Deltamethrin sublethal concentrations during the initial embryonic development, ovulation induction was performed on female fishes using hormones, and then and egg collection was performed. The eggs were then hydrated and fertilized in Cypermethrin and Deltamethrin in different concentrations: 0.001, 0.01, 0.1, 1.0 and 10.0mg/L of Cypermethrin and 0.001, 0.01, 0.1, 0.5 and 1.0mg/L of Deltamethrin, in addition to the control group (0mg/L. After fertilization, the eggs were kept in containers with the respective pesticides of Cypermethrin and Deltamethrin until hatching, when hatching rate was verified. Then the alevins, from the hatching, were kept on their respective concentrations of Cypermethrin and Deltamethrin so that the survival rate could be analyzed regarding the tested insecticides, during both 12-hour and 24-hour periods

  20. Preparation of silver nanoparticles at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Mini, E-mail: mishramini5@gmail.com [Centre of Environmental Science, Department of Botany, University of Allahabad, Allahabad, U.P. (India); Chauhan, Pratima, E-mail: mangu167@yahoo.co.in [Department of Physics, University of Allahabad, Allahabad U.P. (India)

    2016-04-13

    Silver from ancient time is used as antimicrobial agent in the bulk form but now with the advancement in nanotechnology silver in the form of nanoparticles shown potential effect against microbes which make us easy to fight with many diseases plants and animals. In this work silver nanoparticles were synthesized by chemical routes using sodium borohydride as reducing agent at low temperature. The particles were characterized through UV-Visible spectroscopy as well as X-Ray Diffraction. The UV-visible spectra of silver nanoparticles exhibited absorption at 425 cm; the crystallite size of the particles is between 19nm to 39nm. EDAX graph shows two peaks of silver and oxygen. Water absorbed by silver nanoparticles was removed by the calcinations.

  1. Biosynthesis of Silver Nanoparticles and Its Applications

    OpenAIRE

    M. Jannathul Firdhouse; Lalitha, P

    2015-01-01

    Silver nanoparticles possess unique properties which find myriad applications such as antimicrobial, anticancer, larvicidal, catalytic, and wound healing activities. Biogenic syntheses of silver nanoparticles using plants and their pharmacological and other potential applications are gaining momentum owing to its assured rewards. This critical review is aimed at providing an insight into the phytomediated synthesis of silver nanoparticles, its significant applications in various fields, and c...

  2. Multifunctionality of silver closo-boranes

    DEFF Research Database (Denmark)

    Paskevicius, Mark; Hansen, Bjarne R. S.; Jorgensen, Mathias

    2017-01-01

    Silver compounds share a rich history in technical applications including photography, catalysis, photocatalysis, cloud seeding and as antimicrobial agents. Here we present a class of silver compounds (Ag2B10H10 and Ag2B12H12) that are semiconductors with a bandgap at 2.3 eV in the green visible...... of silver closo-boranes and open up avenues in a wide range of fields including photocatalysis, solid state ionics and nano-wire production....

  3. Risk assessment of silver nanoparticles

    Science.gov (United States)

    Shipelin, V. A.; Gmoshinski, I. V.; Khotimchenko, S. A.

    2015-11-01

    Nanoparticles of metallic silver (Ag) are among the most widely used products of nanotechnology. Nanosized colloidal silver (NCS) is presented in many kinds of production as solutions of particles with diameter less than 100 nm. NCS is used in a variety of fields, including food supplements, medicines, cosmetics, packaging materials, disinfectants, water filters, and many others. Problems of toxicity and related safety of NCS for humans and environmental systems are recently overestimated basing on data of numerous toxicological studies in vitro and in vivo. The article discusses the results of current studies in recent years and the data of author's own experiments on studying the safety of NCS, that allows to move on to risk assessment of this nanomaterial presented in consumer products and environmental samples.

  4. Topical silver for infected wounds.

    Science.gov (United States)

    Beam, Joel W

    2009-01-01

    Vermeulen H, van Hattem JM, Storm-Versloot MN, Ubbink DT. Topical silver for treating infected wounds. Cochrane Database Syst Rev. 2007(1);CD005486. What is the clinical evidence base for silver dressings in the management of contaminated and infected acute and chronic wounds? Investigations were identified by Cochrane Wounds Group Specialized Register (2006), CENTRAL (2006), MEDLINE (2002-2006), EMBASE (2002-2006), CINAHL (2002-2006), and digital dissertations (2006) searches. Product manufacturers were contacted to identify additional eligible studies. The search terms included wound infection, surgical wound infection, ulcer, wound healing, and silver. Each study fulfilled the following criteria: (1) The study was a randomized controlled trial of human participants that compared dressings containing silver with any dressings without silver, dressings with other antiseptics, or dressings with different dosages of silver. (2) The participants were aged 18 years and older with contaminated and infected open wounds of any cause. (3) The study had to evaluate the effectiveness of the dressings using an objective measure of healing. No language or publication status restrictions were imposed, and participants could be recruited in any care setting. Studies were excluded if the wounds were ostomies (surgically formed passages). Study quality assessment was conducted independently by 3 authors using the Dutch Institute for Health Care Improvement and Dutch Cochrane Centre protocols. Characteristics of the study, participants, interventions, and outcome measures were extracted by one author and verified by a second using a standard form. The principal outcome measure was healing (time to complete healing, rate of change in wound area and volume, number and proportion of wounds healed within trial period). Secondary measures were adverse events (eg, pain, maceration, erythema), dressing leakage, and wound odor. Based on the unique comparisons in the studies, a meta

  5. Is Cl- protection against silver toxicity due to chemical speciation?

    Science.gov (United States)

    Bielmyer, G K; Brix, K V; Grosell, M

    2008-04-28

    In freshwater teleosts, the primary mechanism of acute silver toxicity is inhibition of Na(+)/K(+) ATPase and carbonic anhydrase at the gill, leading to net Na(+) and Cl(-) loss due to the continued diffusion of these ions into the hypoosmotic external environment. External Cl(-) has been shown to protect rainbow trout (Oncorhychus mykiss) against silver toxicity presumably by complexation to form AgCl. However, Cl(-) does not appear to greatly influence silver toxicity to at least two other species, the European eel (Anguilla Anguilla) and the fathead minnow (Pimephales promelas). We hypothesized that differences in protective effects of Cl(-) at the gill were due to differing requirements or mechanisms for Cl(-) uptake among fish species. To test this hypothesis, we exposed Fundulus heteroclitus, which does not take up Cl(-) across the gills, and Danio rerio and P. promelas, which do rely on Cl(-) uptake across the gills, to Ag(+) in waters of varying Cl(-) concentration. The 96-h LC50s of F. heteroclitus exposed to Ag(+) in soft water with 10 microM Cl(-), 1mM KCl, and 0.5mM MgCl(2) were 3.88, 1.20, and 3.20 microg/L, respectively, and not significantly different. The 96-h LC50s for D. rerio exposed to Ag(+) in soft water with 10 microM Cl(-) and 1mM KCl were 10.3 and 11.3 microg/L, respectively and P. promelas exposed under the same conditions were 2.32 and 2.67 microg/L, respectively. Based on these results, increasing external Cl(-) concentration by as much as 1mM (35.5mg/L) did not offer protection against Ag(+) toxicity to any fish species tested. Although previous results in our laboratory have demonstrated that P. promelas do take up Cl(-) at the gill, a mechanism of uptake has not been identified. Additional experiments, investigating the mechanisms of Na(+) and Cl(-) influx at the gill of P. promelas and the influence of silver, demonstrated that Cl(-) uptake in P. promelas acclimated to soft water occurs through both a Na(+):K(+):2Cl(-) co

  6. Female sterilization.

    Science.gov (United States)

    Chapman, Lynne; Magos, Adam

    2008-07-01

    There has been considerable development and implementation of new contraceptive methods over the last 15 years. However, sterilization has remained the most widely used method around the world. Ideally, the procedure should be safe, have a high efficacy, be readily accessible, and be personally and culturally acceptable. The cost for each procedure would be low and the method would be simple, quick, easily learned and be able to be performed in an outpatient setting without general anesthesia. A transuterine method of female sterilization has long been the ideal for the gynecologist. The Essure system fulfils many of the criteria, and is the first one to be approved by the US FDA. However, there is still a need for further research to find a device with the success rate of the Essure but without its irreversibility.

  7. Effects of water hardness on size and hatching success of silver carp eggs

    Science.gov (United States)

    Rach, Jeff J.; Sass, Greg G.; Luoma, James A.; Gaikowski, Mark P.

    2010-01-01

    Eggs of silver carp Hypophthalmichthys molitrix absorb water after release from the female, causing them to become turgid and to increase substantially in size. The volume of water that diffuses within an egg is most likely determined by (1) the difference in ionic concentration between the egg and the water that surrounds it and (2) the elasticity of the egg membrane. Prior observations suggest that silver carp eggs may swell and burst in soft waters. If water hardness affects silver carp reproductive success in nonnative ecosystems, this abiotic factor could limit silver carp distribution or abundance. In this study, we tested the effect of water hardness on silver carp egg enlargement and hatching success. Groups of newly fertilized silver carp eggs were placed in water at one of five nominal water hardness levels (50, 100, 150, 200, or 250 mg/L as CaCO3) for 1 h to harden (absorb water after fertilization). Egg groups were then placed in separate incubation vessels housed in two recirculation systems that were supplied with either soft (50 mg/L as CaCO3) or hard (250 mg/L as CaCO3) water to evaluate hatching success. Tests were terminated within 24 h after viable eggs had hatched. Eggs that were initially placed in 50-mg/L water to harden were larger (i.e., swelled more) and had a greater probability of hatch than eggs hardened in other water hardness levels. Unlike the effect of water hardness during egg hardening, the water hardness during incubation appeared to have no effect on egg hatching success. Our research suggests that water hardness may not be a limiting factor in the reproduction, recruitment, and range expansion of silver carp in North America.

  8. Biogenic silver nanoparticles associated with silver chloride nanoparticles (Ag@AgCl) produced by laccase from Trametes versicolor.

    Science.gov (United States)

    Durán, Nelson; Cuevas, Raphael; Cordi, Livia; Rubilar, Olga; Diez, Maria Cristina

    2014-01-01

    In the present study, semi-purified laccase from Trametes versicolor was applied for the synthesis of silver nanoparticles, and the properties of the produced nanoparticles were characterized. All of the analyses of the spectra indicated silver nanoparticle formation. A complete characterization of the silver nanoparticles showed that a complex of silver nanoparticles and silver ions was produced, with the majority of the particles having a Ag(2+) chemical structure. A hypothetical mechanistic scheme was proposed, suggesting that the main pathway that was used was the interaction of silver ions with the T1 site of laccase, producing silver nanoparticles with the concomitant inactivation of laccase activity and posterior complexing with silver ions.

  9. Uptake and elimination kinetics of silver nanoparticles and silver nitrate by Raphidocelis subcapitata: The influence of silver behaviour in solution

    NARCIS (Netherlands)

    Ribeiro, Fabianne; Gallego-Urrea, Julián Alberto; Goodhead, Rhys M.; van Gestel, C.A.M.; Moeger, Julian; Soares, Amadeu M.V.M.; Loureiro, Susana

    2015-01-01

    Raphidocelis subcapitata is a freshwater algae species that constitutes the basis of many aquatic trophic chains. In this study, R. subcapitata was used as a model species to investigate the kinetics of uptake and elimination of silver nanoparticles (AgNP) in comparison to silver nitrate

  10. Synthesis and antimicrobial effects of silver nanoparticles

    Directory of Open Access Journals (Sweden)

    S kheybari

    2010-09-01

    Full Text Available "n  "n "nBackground and the purpose of the study:The most prominent nanoparticles for medical uses are nanosilver particles which are famous for their high anti-microbial activity. Silver ion has been known as a metal ion that exhibit anti-mold, anti-microbial and anti-algal properties for a long time. In particular, it is widely used as silver nitrate aqueous solution which has disinfecting and sterilizing actions. The purpose of this study was to evaluate the antimicrobial activity as well as physical properties of the silver nanoparticles prepared by chemical reduction method. "nMethods:Silver nanoparticles (NPs were prepared by reduction of silver nitrate in the presence of a reducing agent and also poly [N-vinylpyrolidone] (PVP as a stabilizer. Two kinds of NPs were synthesized by ethylene glycol (EG and glucose as reducing agent. The nanostructure and particle size of silver NPs were confirmed by scanning electron microscopy (SEM and laser particle analyzer (LPA. The formations of the silver NPs were monitored using ultraviolet-visible spectroscopy. The anti-bacterial activity of silver NPs were assessed by determination of their minimum inhibitory concentrations (MIC against the Gram positive (Staphylococcus aureus and Staphylococcus epidermidis as well as Gram-negative (Escherichia coli and Pseudomonas aeruginosa bacteria. "nResults and Conclusion:The silver nanoparticles were spherical with particle size between 10 to 250 nm. Analysis of the theoretical (Mie light scattering theory and experimental results showed that the silver NPs in colloidal solution had a diameter of approximately 50 nm. "nBoth colloidal silver NPs showed high anti-bacterial activity against Gram positive and Gram negative bacteria. Glucose nanosilver colloids showed a shorter killing time against most of the tested bacteria which could be due to their nanostructures and uniform size distribution patterns.

  11. Distribution of silver in rats following 28 days of repeated oral exposure to silver nanoparticles or silver acetate

    Directory of Open Access Journals (Sweden)

    Mortensen Alicja

    2011-06-01

    Full Text Available Abstract Background The study investigated the distribution of silver after 28 days repeated oral administration of silver nanoparticles (AgNPs and silver acetate (AgAc to rats. Oral administration is a relevant route of exposure because of the use of silver nanoparticles in products related to food and food contact materials. Results AgNPs were synthesized with a size distribution of 14 ± 4 nm in diameter (90% of the nanoparticle volume and stabilized in aqueous suspension by the polymer polyvinylpyrrolidone (PVP. The AgNPs remained stable throughout the duration of the 28-day oral toxicity study in rats. The organ distribution pattern of silver following administration of AgNPs and AgAc was similar. However the absolute silver concentrations in tissues were lower following oral exposure to AgNPs. This was in agreement with an indication of a higher fecal excretion following administration of AgNPs. Besides the intestinal system, the largest silver concentrations were detected in the liver and kidneys. Silver was also found in the lungs and brain. Autometallographic (AMG staining revealed a similar cellular localization of silver in ileum, liver, and kidney tissue in rats exposed to AgNPs or AgAc. Using transmission electron microscopy (TEM, nanosized granules were detected in the ileum of animals exposed to AgNPs or AgAc and were mainly located in the basal lamina of the ileal epithelium and in lysosomes of macrophages within the lamina propria. Using energy dispersive x-ray spectroscopy it was shown that the granules in lysosomes consisted of silver, selenium, and sulfur for both AgNP and AgAc exposed rats. The diameter of the deposited granules was in the same size range as that of the administered AgNPs. No silver granules were detected by TEM in the liver. Conclusions The results of the present study demonstrate that the organ distribution of silver was similar when AgNPs or AgAc were administered orally to rats. The presence of silver

  12. Electrically Conductive Silver Paste Obtained by Use of Silver Neodecanoate as Precursor

    Science.gov (United States)

    Shen, Longguang; Liu, Jianguo; Zeng, Xiaoyan; Ren, Zhao

    2015-02-01

    An electrically conductive silver paste has been prepared from an organometallic compound, silver neodecanoate, as silver precursor. The precursor was highly soluble in organic solvents and decomposed into metallic silver at low sintering temperatures (pseudoplastic liquid with viscosity in the range 6.5-9 Pa s. The paste was compatible with the micro-pen direct-writing process, enabling production of silver lines on a substrate. The electrical resistivity of the silver lines was 9 × 10-6 Ω cm after sintering at 115°C for 60 min, 5.8 × 10-6 Ω cm when sintered at 150°C for 60 min, and 3 × 10-6 Ω cm when sintered above 300°C, values which are similar to those of bulk silver. Hence, the prepared paste can be successfully used on flexible substrates such as polymers.

  13. Development of nanostructured silver vanadates decorated with silver nanoparticles as a novel antibacterial agent

    Energy Technology Data Exchange (ETDEWEB)

    Holtz, R D; Souza Filho, A G; Alves, O L [Laboratorio de Quimica do Estado Solido (LQES), Instituto de Quimica, Universidade Estadual de Campinas, CP 6154, 13081-970, Campinas-SP (Brazil); Brocchi, M; Martins, D [Departamento de Genetica, Evolucao and Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas, Campinas-SP (Brazil); Duran, N, E-mail: rholtz@iqm.unicamp.br, E-mail: agsf@fisica.ufc.br, E-mail: oalves@iqm.unicamp.br [Laboratorio de Quimica Biologica, Instituto de Quimica, Universidade Estadual de Campinas, Campinas-SP (Brazil)

    2010-05-07

    In this work we report the synthesis, characterization and application of silver vanadate nanowires decorated with silver nanoparticles as a novel antibacterial agent. These hybrid materials were synthesized by a precipitation reaction of ammonium vanadate and silver nitrate followed by hydrothermal treatment. The silver vanadate nanowires have lengths of the order of microns and diameters around 60 nm. The silver nanoparticles decorating the nanowires present a diameter distribution varying from 1 to 20 nm. The influence of the pH of the reaction medium on the chemical structure and morphology of silver vanadates was studied and we found that synthesis performed at pH 5.5-6.0 led to silver vanadate nanowires with a higher morphological yield. The antimicrobial activity of these materials was evaluated against three strains of Staphylococcus aureus and very promising results were found. The minimum growth inhibiting concentration value against a MRSA strain was found to be ten folds lower than for the antibiotic oxacillin.

  14. PEMIJAHAN ALAMI ARWANA SILVER (Osteoglossum bicirrhosum DALAM BAK TERKONTROL

    Directory of Open Access Journals (Sweden)

    Agus Priyadi

    2016-11-01

    Full Text Available Ikan arwana silver (Osteoglossum bicirrhosum adalah ikan hias introduksi berasal dari Brazil yang sudah menjadi ikan hias potensial. Tujuan penelitian ini ialah untuk mengetahui teknik pemijahan secara alami ikan arwana silver dalam bak terkontrol. Induk arwana jantan dan betina yang sudah diberi penanda (tagging sebanyak 12 ekor diadaptasikan dalam bak beton (3 m x 2 m x 1 m yang diletakkan di dalam ruangan yang dilengkapi dengan instalasi aerasi. Pakan diberikan berupa percil (50 g dan ikan selar (360 g dua hari sekali. Setelah 10 bulan ikan arwana mencapai panjang berkisar 59-64 cm dan bobot berkisar 1.208,5-1.849,5 g. Semua ikan arwana (11 ekor dipindah ke luar ruangan, dipelihara dalam bak beton (5 m x 2 m x 1.2 m dengan media air yang diputar menggunakan pompa dan bak pemeliharaan ditutup dengan jala. Pakan diberikan sama seperti saat adaptasi. Pengamatan keberhasilan pemijahan ikan dilakukan setiap saat dengan mengetahui ada tidaknya telur yang dierami dalam mulut arwana jantan. Pengeluaran larva dari dalam mulut induk jantan dilakukan setelah telur dierami selama 1-1,5 bulan. Hasil penelitian menunjukkan bahwa setelah 8 bulan pemeliharaan di luar ruangan, arwana silver jantan terlihat mengerami telur dalam mulutnya pertama kali dan menghasilkan larva sebanyak 17 ekor, kemudian berturut-turut menghasilkan larva setiap bulan pada bulan ke-22, 23, dan 24 berkisar 25-107 ekor/induk/bulan.  Silver arowana (Osteoglossum bicirrhosum is an ornamental fish introduced from Brazil and has been popular among fish collectors. The objective of this research was to determine the optimal spawning technique of silver arowana in controlled tank. Tagged male and female of arowana broodstock were adapted in 3 m x 2 m x 1 m indoor concrete tank with stocking density of 12 individual/tank. Lift frogs (50 g and raw fish (360 g were given as feed once per two days. After ten months of rearing, the total length of silver arowana broodstock varied from 59 to 64

  15. Biosynthesis of silver nanoparticles synthesized by Aspergillus ...

    Indian Academy of Sciences (India)

    In the present study, biosynthesis of silver nanoparticles and its antioxidant, antimicrobial and cytotoxic activities were investigated. Silver nanoparticles were extracellularly synthesized using Aspergillus flavus and the formation of nanoparticles was observed after 72 h of incubation. The results recorded from colour ...

  16. Synthesis and characterization of fluorophore attached silver ...

    Indian Academy of Sciences (India)

    Administrator

    - sized using starch as both reducing and stabilizing agent. Such starch stabilized silver nanoparticles were attached with rhodamine 6G for in vivo studies. So far no in vivo study was done for silver nanoparticles in animals except for some in ...

  17. Preparation of amine coated silver nanoparticles using ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. This article presents a simple method towards the preparation of functionalized silver nano- particles in a continuous medium. Silver nanoparticles were obtained through AgNO3 chemical reduction in ethanol and triethylenetetramine was used to stabilize and functionalize the metal. The product was characterized ...

  18. ECO-FRIENDLY SYNTHESIS OF SILVER NANOPARTICLES ...

    African Journals Online (AJOL)

    userpc

    as medical diagnosis/therapy, solar cell development, water treatment, surface coating and cosmetic production. Bacterial synthesis of silver nanoparticles is regarded as eco-friendly due to minimal waste generated while being energy efficient. This study was aimed at synthesizing silver nanoparticles using Lactobacillus ...

  19. Intravesical silver nitrate for refractory hemorrhagic cystitis.

    Science.gov (United States)

    Montgomery, Brian D; Boorjian, Stephen A; Ziegelmann, Matthew J; Joyce, Daniel D; Linder, Brian J

    2016-09-01

    Hemorrhagic cystitis is a challenging clinical entity with limited evidence available to guide treatment. The use of intravesical silver nitrate has been reported, though supporting literature is sparse. Here, we sought to assess outcomes of patients treated with intravesical silver nitrate for refractory hemorrhagic cystitis. We identified nine patients with refractory hemorrhagic cystitis treated at our institution with intravesical silver nitrate between 2000-2015. All patients had failed previous continuous bladder irrigation with normal saline and clot evacuation. Treatment success was defined as requiring no additional therapy beyond normal saline irrigation after silver nitrate instillation prior to hospital discharge. Median patient age was 80 years (IQR 73, 82). Radiation was the most common etiology for hemorrhagic cystitis 89% (8/9). Two patients underwent high dose (0.1%-0.4%) silver nitrate under anesthesia, while the remaining seven were treated with doses from 0.01% to 0.1% via continuous bladder irrigation for a median of 3 days (range 2-4). All nine patients (100%) had persistent hematuria despite intravesical silver nitrate therapy, requiring additional interventions and red blood cell transfusion during the hospitalization. There were no identified complications related to intravesical silver nitrate instillation. Although well tolerated, we found that intravesical silver nitrate was ineffective for bleeding control, suggesting a limited role for this agent in the management of patients with hemorrhagic cystitis.

  20. Fluorescent silver nanoparticles via exploding wire technique

    Indian Academy of Sciences (India)

    (SPR) of silver nanoparticles has been studied extensively [1] concluding particle size, shape and surrounding environment dependence. However, only a few re- searchers were able to observe the fluorescence behavior of silver nanoparticles and hence research is going on in order to understand the physics behind the ...

  1. Silver disinfection in water distribution systems

    Science.gov (United States)

    Silvestry Rodriguez, Nadia

    Silver was evaluated as disinfectant to maintain water quality in water distribution system. It was used to inhibit growth of two opportunistic bacteria in planktonik form and in biofilm formation in Robbins devices with stainless steel and PVC surfaces. The results of this work show that silver is a potential secondary disinfectant to be used in water distribution systems.

  2. Preparation, Characterization and Antibacterial Properties of Silver ...

    African Journals Online (AJOL)

    Purpose: To study the effect of chitosan molecular weight on the physicochemical and antibacterial properties of silver-chitosan nanoparticles. Methods: A series of silver-chitosan nanoparticles of different sizes were produced using various molecular weight (MW) grades of chitosan by an aqueous chemical reduction ...

  3. Synthesis and characterization of fluorophore attached silver ...

    Indian Academy of Sciences (India)

    Silver nanoparticles stabilized by soluble starch were synthesized and characterized. in vivo studies in rats showed no toxicity and revealed their distribution in various tissues and permeability across BBB. This starch stabilized silver nanoparticles have good biological characteristics to act as a potential promising vector for ...

  4. Preparation of silver powder through glycerol process

    Indian Academy of Sciences (India)

    High purity fine silver powder with uniform particle morphology was prepared through glycerol process. The process involves reduction of silver nitrate by glycerol under atmospheric conditions at a temperature below 175°C. Glycerol, in this process, acts as a solvent as well as a reducing agent. The powders prepared ...

  5. Female Versus Male Entrepreneurship within Europe

    Directory of Open Access Journals (Sweden)

    Ardelean Dorina

    2015-08-01

    Full Text Available Entrepreneurship is a topic much debated and analyzed by many research institutions and organizations. In recent years, the total number of entrepreneurs has been increasing significantly, female entrepreneurship being the one that has increased a lot. In this study, we are going to present and analyze the results of studies conducted at European level regarding the comparative evolution of male versus female entrepreneurship. The main conclusion that emerges from the analysis of the results obtained is that the number of women entrepreneurs is almost equal to that of men entrepreneurs in many European countries.

  6. Silver manganese oxide electrodes for lithium batteries

    Energy Technology Data Exchange (ETDEWEB)

    Thackeray, Michael M.; Vaughey, John T.; Dees, Dennis W.

    2006-05-09

    This invention relates to electrodes for non-aqueous lithium cells and batteries with silver manganese oxide positive electrodes, denoted AgxMnOy, in which x and y are such that the manganese ions in the charged or partially charged electrodes cells have an average oxidation state greater than 3.5. The silver manganese oxide electrodes optionally contain silver powder and/or silver foil to assist in current collection at the electrodes and to improve the power capability of the cells or batteries. The invention relates also to a method for preparing AgxMnOy electrodes by decomposition of a permanganate salt, such as AgMnO4, or by the decomposition of KMnO4 or LiMnO4 in the presence of a silver salt.

  7. Silver manganese oxide electrodes for lithium batteries

    Science.gov (United States)

    Thackeray, Michael M.; Vaughey, John T.; Dees, Dennis W.

    2006-05-09

    This invention relates to electrodes for non-aqueous lithium cells and batteries with silver manganese oxide positive electrodes, denoted AgxMnOy, in which x and y are such that the manganese ions in the charged or partially charged electrodes cells have an average oxidation state greater than 3.5. The silver manganese oxide electrodes optionally contain silver powder and/or silver foil to assist in current collection at the electrodes and to improve the power capability of the cells or batteries. The invention relates also to a method for preparing AgxMnOy electrodes by decomposition of a permanganate salt, such as AgMnO4, or by the decomposition of KMnO4 or LiMnO4 in the presence of a silver salt.

  8. Silver dressings--do they work?

    Science.gov (United States)

    2010-04-01

    The metal silver is well known to have antimicrobial properties and this underlies its incorporation into the many types of silver releasing wound dressings available in the UK. These products are classed as 'advanced' dressings and were developed primarily for difficult to heal wounds, chronic ulcers and extensive burns.1 The use of silver dressings has increased rapidly in recent years in the UK, with the amount spent on such products in the NHS being around pound23million in 2005 and around pound25million in 2006/7.2(,)3 The latter figure represents a quarter of the total cost of wound dressings, with one seventh of the wound dressing items prescribed being silver dressings.3 Here we discuss the evidence on the place of silver dressings in burns, chronic ulcers and acute wounds.

  9. Corrosion processes of triangular silver nanoparticles compared to bulk silver

    Energy Technology Data Exchange (ETDEWEB)

    Keast, V. J., E-mail: vicki.keast@newcastle.edu.au; Myles, T. A. [University of Newcastle, School of Mathematical and Physical Sciences (Australia); Shahcheraghi, N.; Cortie, M. B. [University of Technology Sydney, Institute for Nanoscale Technology (Australia)

    2016-02-15

    Excessive corrosion of silver nanoparticles is a significant impediment to their use in a variety of potential applications in the biosensing, plasmonic and antimicrobial fields. Here we examine the environmental degradation of triangular silver nanoparticles (AgNP) in laboratory air. In the early stages of corrosion, transmission electron microscopy shows that dissolution of the single-crystal, triangular, AgNP (side lengths 50–120 nm) is observed with the accompanying formation of smaller, polycrystalline Ag particles nearby. The new particles are then observed to corrode to Ag{sub 2}S and after 21 days nearly full corrosion has occurred, but some with minor Ag inclusions remaining. In contrast, a bulk Ag sheet, studied in cross section, showed an adherent corrosion layer of only around 20–50 nm in thickness after over a decade of being exposed to ambient air. The results have implications for antibacterial properties and ecotoxicology of AgNP during corrosion as the dissolution and reformation of Ag particles during corrosion will likely be accompanied by the release of Ag{sup +} ions.

  10. Green synthesis of silver nanoparticles from leaf extracts of ...

    African Journals Online (AJOL)

    In this work, metallic silver nanoparticles were synthesized from leaf extracts of Parquetina nigrescens and Synedrella nodiflora. Silver ion was reduced to metallic silver on treatment of AgNO solution with aqueous extracts of the 3 two plants within 30minutes. The effects of time and the volume of extract to silver salt solution ...

  11. 21 CFR 872.3840 - Endodontic silver point.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Endodontic silver point. 872.3840 Section 872.3840...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3840 Endodontic silver point. (a) Identification. An endodontic silver point is a device made of silver intended for use during endodontic therapy to...

  12. Suitsetamisega võitlemisel ei aita inimeste kiusamine / Silver Meikar

    Index Scriptorium Estoniae

    Meikar, Silver, 1978-

    2004-01-01

    Suitsetamise vastu võitlemisel ei tohiks kasutada rangelt seadusi vaid võimaldada soodsalt osta suitsetamisvastaseid vahendeid, leiab autor. Vt. ka: Silver Meikar: Olen valmis hoidma Eesti edu; Silver Meikar saatis lugejakirja Saksamaa päevalehtedele; Arvamusi Silver Meikarist; Silver Meikar loobus paberkandjale trükitud seaduseelnõudest

  13. Nanopackaging of Silver using Spice Extract and their ...

    African Journals Online (AJOL)

    The aim of the present study was to synthesize silver nanoparticles using spice extracts as reducing agents and further evaluate their anti-microbial activities. Silver has been shown to possess antimicrobial activity. The silver nanoparticles were prepared by solvent evaporation method. The silver nanoparticles were ...

  14. Mycosynthesis of Silver Nanoparticles from Candida albicans and its ...

    African Journals Online (AJOL)

    Purpose: To produce and characterize silver nanoparticles using Candida albicans and evaluate its antibacterial properties. Methods: Extracellular silver nanoparticles were biosynthesized using C. albicans. The biomass obtained from cultures of C. albicans was used to synthesize silver nanoparticles in 1.5 mM silver ...

  15. Silver Uptake and Reuse of Biomass by Saccharomyces cerevisiae ...

    African Journals Online (AJOL)

    Studies were carried out on the recovery of bound silver and reuse of Chlorella emersonii and Saccharomyces cerevisiae biomass for further silver uptake after they were placed in contact with 20mg/l silver for 30 minutes to allow for maximum binding. It was found that 0.16M nitric acid gave the best recovery rates of silver.

  16. Electrospun polyacrylonitrile nanofibers loaded with silver nanoparticles by silver mirror reaction

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Yongzheng; Li, Yajing; Zhang, Jianfeng; Yu, Zhongzhen; Yang, Dongzhi, E-mail: yangdz@mail.buct.edu.cn

    2015-06-01

    The silver mirror reaction (SMR) method was selected in this paper to modify electrospun polyacrylonitrile (PAN) nanofibers, and these nanofibers loaded with silver nanoparticles showed excellent antibacterial properties. PAN nanofibers were first pretreated in AgNO{sub 3} aqueous solution before the SMR process so that the silver nanoparticles were distributed evenly on the outer surface of the nanofibers. The final PAN nanofibers were characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), transmission electron microscopy (TEM), TEM-selected area electron diffraction (SAED), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). SEM, TEM micrographs and SAED patterns confirmed homogeneous dispersion of the silver nanoparticles which were composed of monocrystals with diameters 20–30 nm. EDS and XRD results showed that these monocrystals tended to form face-centered cubic single silver. TGA test indicated that the nanoparticles loaded on the nanofibers reached above 50 wt.%. This material was also evaluated by the viable cell-counting method. The results indicated that PAN nanofibers loaded with silver nanoparticles exhibited excellent antimicrobial activities against gram-negative Escherichia coli (E. coli), gram-positive Staphylococcus aureus (S. aureus) and the fungus Monilia albicans. Thus, this material had many potential applications in biomedical fields. - Highlights: • Silver mirror reaction was used to prepare nanofibers loaded with silver nanoparticles. • The SAED patterns demonstrated the monocrystallinity of silver nanocrystals. • The XRD results showed nanoparticles tended to be face-centered cubic single silver. • The material showed excellent antimicrobial activities against bacteria and fungi.

  17. Female Reproductive System

    Science.gov (United States)

    ... Kidney Transplant Vision Facts and Myths Female Reproductive System KidsHealth > For Parents > Female Reproductive System Print A ... or sperm. continue Parts of the Female Reproductive System Unlike the male, the human female has a ...

  18. Polystyrene Based Silver Selective Electrodes

    Directory of Open Access Journals (Sweden)

    Shiva Agarwal

    2002-06-01

    Full Text Available Silver(I selective sensors have been fabricated from polystyrene matrix membranes containing macrocycle, Me6(14 diene.2HClO4 as ionophore. Best performance was exhibited by the membrane having a composition macrocycle : Polystyrene in the ratio 15:1. This membrane worked well over a wide concentration range 5.0×10-6–1.0×10-1M of Ag+ with a near-Nernstian slope of 53.0 ± 1.0 mV per decade of Ag+ activity. The response time of the sensor is <15 s and the membrane can be used over a period of four months with good reproducibility. The proposed electrode works well in a wide pH range 2.5-9.0 and demonstrates good discriminating power over a number of mono-, di-, and trivalent cations. The sensor has also been used as an indicator electrode in the potentiometric titration of silver(II ions against NaCl solution. The sensor can also be used in non-aqueous medium with no significant change in the value of slope or working concentration range for the estimation of Ag+ in solution having up to 25% (v/v nonaqueous fraction.

  19. Silver in health care: antimicrobial effects and safety in use.

    Science.gov (United States)

    Lansdown, Alan B G

    2006-01-01

    Silver has a long and intriguing history as an antibiotic in human health care. It has been developed for use in water purification, wound care, bone prostheses, reconstructive orthopaedic surgery, cardiac devices, catheters and surgical appliances. Advancing biotechnology has enabled incorporation of ionizable silver into fabrics for clinical use to reduce the risk of nosocomial infections and for personal hygiene. The antimicrobial action of silver or silver compounds is proportional to the bioactive silver ion (Ag(+)) released and its availability to interact with bacterial or fungal cell membranes. Silver metal and inorganic silver compounds ionize in the presence of water, body fluids or tissue exudates. The silver ion is biologically active and readily interacts with proteins, amino acid residues, free anions and receptors on mammalian and eukaryotic cell membranes. Bacterial (and probably fungal) sensitivity to silver is genetically determined and relates to the levels of intracellular silver uptake and its ability to interact and irreversibly denature key enzyme systems. Silver exhibits low toxicity in the human body, and minimal risk is expected due to clinical exposure by inhalation, ingestion, dermal application or through the urological or haematogenous route. Chronic ingestion or inhalation of silver preparations (especially colloidal silver) can lead to deposition of silver metal/silver sulphide particles in the skin (argyria), eye (argyrosis) and other organs. These are not life-threatening conditions but cosmetically undesirable. Silver is absorbed into the human body and enters the systemic circulation as a protein complex to be eliminated by the liver and kidneys. Silver metabolism is modulated by induction and binding to metallothioneins. This complex mitigates the cellular toxicity of silver and contributes to tissue repair. Silver allergy is a known contra-indication for using silver in medical devices or antibiotic textiles.

  20. Preparation and Characterization of Gelatin Nanofibers Containing Silver Nanoparticles

    OpenAIRE

    Lim Jeong; Won Ho Park

    2014-01-01

    Ag nanoparticles (NPs) were synthesized in formic acid aqueous solutions through chemical reduction. Formic acid was used for a reducing agent of Ag precursor and solvent of gelatin. Silver acetate, silver tetrafluoroborate, silver nitrate, and silver phosphate were used as Ag precursors. Ag+ ions were reduced into Ag NPs by formic acid. The formation of Ag NPs was characterized by a UV-Vis spectrophotometer. Ag NPs were quickly generated within a few minutes in silver nitrate (AgNO3)/formic ...

  1. Nanostructured Antibacterial Silver Deposited on Polypropylene Nonwovens

    Science.gov (United States)

    Hong-Bo, Wang; Jin-Yan, Wang; Qu-Fu, Wei; Jian-Han, Hong; Xiao-Yan, Zhao

    Nanostructured silver films were deposited on polypropylene (PP) nonwovens by RF magnetron sputter coating to obtain the antibacterial properties. Shake flask test was used to evaluate the antibacterial properties of the materials. Atomic force microscope (AFM) was utilized to observe the surface morphology. Energy-dispersive X-ray (EDX) was also employed to analyze the surface elemental compositions. The antibacterial results indicated that the prolonged deposition time led to a significant improvement in antibacterial effect, and sputtering power and argon pressure did not show obvious effect on antibacterial performance. It is believed that the total amount of silver ions released from the silver coating was increased as the deposition time increased. AFM images and quantitative analysis of EDX, respectively revealed that increase in deposition time led to the increased coverage of silver film and the increased silver weight percentage per unit surface, which provided evidences for the increased release rate of silver ions from the coating. Moreover, it was found that the optimum silver coating thickness was about 3 nm, taking antibacterial effect and cost of production into account.

  2. Deposition of amorphous carbon-silver composites

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Zarco, O. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Circuito Exterior s/n, Ciudad Universitaria. 04510, Mexico D. F. Mexico (Mexico); Rodil, S.E., E-mail: ser42@iim.unam.m [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Circuito Exterior s/n, Ciudad Universitaria. 04510, Mexico D. F. Mexico (Mexico); Camacho-Lopez, M.A. [Facultad de Quimica, Universidad Autonoma del Estado de Mexico, Tollocan s/n, esq. Paseo Colon, Toluca, Estado de Mexico, 50110 (Mexico)

    2009-12-31

    Composites of amorphous carbon films and silver were deposited by co-sputtering, where the target (10 cm diameter) was of pure graphite with small inclusion of pure silver (less than 1 cm{sup 2}). The films were deposited under different powers, from 40 to 250 W, and different target-substrate distances. The substrate was earthed and rotated in order to obtain a uniform distribution of the silver content. The addition of the Ag piece into the target increased the deposition rate of the carbon films, which could be related to the higher sputter yield of the silver, but there seems to be also a contribution from a larger emission of secondary electrons from the Ag that enhances the plasma and therefore the sputtering process becomes more efficient. Scanning electron micrographs acquired using backscattered electrons showed that the silver was segregated from the carbon matrix, forming nanoparticles or larger clusters as the power was increased. The X-ray diffraction pattern showed that the silver was crystalline and the carbon matrix remained amorphous, although for certain conditions a peak attributed to fullerene-like structures was obtained. Finally, we used Raman spectroscopy to understand the bonding characteristics of the carbon-silver composites, finding that there are variations in the D/G ratio, which can be correlated to the observed structure and X-ray diffraction results.

  3. Increased sensitivity of lateral flow immunoassay for ochratoxin A through silver enhancement.

    Science.gov (United States)

    Anfossi, L; Di Nardo, F; Giovannoli, C; Passini, C; Baggiani, C

    2013-12-01

    Silver nucleation on gold has been exploited for signal amplification and has found application in several qualitative and quantitative bio-sensing techniques, thanks to the simplicity of the method and the high sensitivity achieved. Very recently, this technique has been tentatively applied to improve the performance of gold-based immunoassays. In this work, the exploitation of the signal amplification due to silver deposition on gold nanoparticles has been first applied to a competitive lateral flow immunoassay (LFIA). The signal enhancement due to silver allowed us to strongly reduce the amount of the competitor and of specific antibodies employed to build an LF device for measuring ochratoxin A (OTA), thus permitting the attainment of a highly sensitive assessment of OTA contamination, with a sensitivity gain of more than 10-fold compared to the gold-based LFIA that used the same immunoreagents and to all previously reported LFIA for measuring OTA. In addition, a less sensitive "quantitative" LFIA could be established, by suitably tuning competitor and antibody amounts, which was characterized by reproducible and accurate OTA determinations (RSD% 6-12%, recovery% 82-117%). The quantitative system allowed a reliable OTA quantification in wines and grape musts at the microgram per liter level requested by the European legislation, as demonstrated by a highly results obtained through the quantitative silver-enhanced LFIA and a reference HPLC-FLD on 30 samples.

  4. Silver Nanoparticles and Graphitic Carbon Through Thermal Decomposition of a Silver/Acetylenedicarboxylic Salt

    Directory of Open Access Journals (Sweden)

    Komninou Philomela

    2009-01-01

    Full Text Available Abstract Spherically shaped silver nanoparticles embedded in a carbon matrix were synthesized by thermal decomposition of a Ag(I/acetylenedicarboxylic acid salt. The silver nanoparticles, which are formed either by pyrolysis at 300 °C in an autoclave or thermolysis in xylene suspension at reflux temperature, are acting catalytically for the formation of graphite layers. Both reactions proceed through in situ reduction of the silver cations and polymerization of the central acetylene triple bonds and the exact temperature of the reaction can be monitored through DTA analysis. Interestingly, the thermal decomposition of this silver salt in xylene partly leads to a minor fraction of quasicrystalline silver, as established by HR-TEM analysis. The graphitic layers covering the silver nanoparticles are clearly seen in HR-TEM images and, furthermore, established by the presence of sp2carbon at the Raman spectrum of both samples.

  5. Presence of nanoparticles in wash water from conventional silver and nano-silver textiles.

    Science.gov (United States)

    Mitrano, Denise M; Rimmele, Elisa; Wichser, Adrian; Erni, Rolf; Height, Murray; Nowack, Bernd

    2014-07-22

    Questions about how to regulate nanoenhanced products regularly arise as researchers determine possible nanoparticle transformation(s). Focusing concern on the incorporation and subsequent release of nano-Ag in fabrics often overshadows the fact that many "conventional silver" antimicrobials such as ionic silver, AgCl, metallic Ag, and other forms will also form different species of silver. In this study we used a laboratory washing machine to simulate the household laundering of a number of textiles prepared with known conventional Ag or nano-Ag treatments and a commercially available fabric incorporating yarns coated with bulk metallic Ag. Serial filtration allowed for quantification of total Ag released in various size fractions (>0.45 μm, nano-Ag treatments. Incorporating nano-silver into the fiber (as opposed to surface treatments) yielded less total Ag during fabric washing. A variety of metallic Ag, AgCl, and Ag/S particles were observed in washing solution by TEM/EDX to various extents depending on the initial Ag speciation in the fabrics. Very similar particles were also observed when dissolved ionic Ag was added directly into the washing liquid. On the basis of the present study, we can state that all silver-treated textiles, regardless of whether the treatment is "conventional" or "nano", can be a source of silver nanoparticles in washing solution when laundering fabrics. Indeed, in this study we observed that textiles treated with "conventional" silver have equal or greater propensity to form nano-silver particles during washing conditions than those treated with "nano"-silver. This fact needs to be strongly considered when addressing the risks of nano-silver and emphasizes that regulatory assessment of nano-silver warrants a similar approach to conventional silver.

  6. Thermal decomposition as route for silver nanoparticles

    Directory of Open Access Journals (Sweden)

    Navaladian S

    2006-01-01

    Full Text Available AbstractSingle crystalline silver nanoparticles have been synthesized by thermal decomposition of silver oxalate in water and in ethylene glycol. Polyvinyl alcohol (PVA was employed as a capping agent. The particles were spherical in shape with size below 10 nm. The chemical reduction of silver oxalate by PVA was also observed. Increase of the polymer concentration led to a decrease in the size of Ag particles. Ag nanoparticle was not formed in the absence of PVA. Antibacterial activity of the Ag colloid was studied by disc diffusion method.

  7. Anti-bacterial Studies of Silver Nanoparticles

    CERN Document Server

    Theivasanthi, T

    2011-01-01

    We discuss about the antibacterial activities of Silver nanoparticles and compare them on both Gram negative and Gram positive bacteria in this investigation. The activities of Silver nanoparticles synthesized by electrolysis method are more in Gram (-) than Gram (+) bacteria. First time, we increase its antibacterial activities by using electrical power while on electrolysis synthesis and it is confirmed from its more antibacterial activities (For Escherichia coli bacteria). We investigate the changes of inner unit cell Lattice constant of Silver nanoparticles prepared in two different methods and its effects on antibacterial activities. We note that slight change of the lattice constant results in the enhancement of its antibacterial activities.

  8. Biogenic silver nanoparticles associated with silver chloride nanoparticles (Ag@AgCl) produced by laccase from Trametes versicolor

    OpenAIRE

    Duran N; Cuevas R.; Cordi L.; Rubilar O.; Diez M.C.

    2014-01-01

    In the present study, semi-purified laccase from Trametes versicolor was applied for the synthesis of silver nanoparticles, and the properties of the produced nanoparticles were characterized. All of the analyses of the spectra indicated silver nanoparticle formation. A complete characterization of the silver nanoparticles showed that a complex of silver nanoparticles and silver ions was produced, with the majority of the particles having a Ag(2+) chemical structure. A hypothetical mechanisti...

  9. Discovery of ionic silver in silver nanoparticle suspension fabricated by arc discharge method

    Energy Technology Data Exchange (ETDEWEB)

    Tien, D.-C. [Graduate Institute of Mechanical and Electrical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan (China)], E-mail: s3408508@ntut.edu.tw; Tseng, K.-H.; Liao, C.-Y.; Huang, J.-C. [Department of Electrical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan (China); Tsung, T.-T. [Graduate Institute of Mechanical and Electrical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan (China)

    2008-09-08

    As a result of mankind's over-reliance on antibiotics, germs are becoming more drug-resistant every year. The gradual but inexorable decline in the efficacy of traditional antibiotics is forcing scientists and doctors to search for new weapons in the fight against germs. Metallic silver nanoparticle (Ag{sup 0}) and ionic silver (Ag{sup +}) are the future of the post-antibiotic era, with the latter playing perhaps the central role in this fight. Using the arc discharge method (ADM), our research has allowed us to fabricate silver nanoparticle suspension (SNPS) in deionized water with no added surfactants. Most related research in this field is confined to explore the composition of nanoparticle, ignoring ions. However, we aim to identify and measure the proportion of ionic silver in ADM-SNPS, using conductivity meters, centrifuges, titrator, and atomic absorption spectrophotometer (AA). The results of our experiments show that SNPS fabricated by means of ADM with no added surfactants contains metallic silver nanoparticle and ionic silver. The fabrication consumes silver rods at a rate of 100 mg/min, yielding metallic silver nanoparticle and ionic silver with concentrations of approximately 11 ppm and 19 ppm, respectively.

  10. Certain Aspects of Silver and Silver Nanoparticles in Wound Care: A Minireview

    Directory of Open Access Journals (Sweden)

    Marek Konop

    2016-01-01

    Full Text Available Resistance to antimicrobial agents by pathogenic bacteria has emerged in recent years and is a major health problem. In this context silver and silver nanoparticles (AgNP have been known to have inhibitory and bactericidal effects and was used throughout history for treatment of skin ulcer, bone fracture, and supporting wound healing. In all of these applications prevention and treatment of bacterial colonized/infected wounds are critical. In this context silver and its derivatives play an important role in health care. Silver is widely used in clinical practice in the form of silver nitrate and/or silver sulfadiazine. In the last few years silver nanoparticles entered into clinical practice as both antimicrobial and antifungal agents. In addition, nanosilver is used in coating medical devices (catheters and as component of wound dressings. In this paper we present summarized information about silver and nanoparticles made of silver in the context of their useful properties, especially antibacterial ones, being of a great interest for researchers and clinicians.

  11. Ultrastructural localization of silver in rat testis and organ distribution of radioactive silver in the rat

    DEFF Research Database (Denmark)

    Ernst, E; Rungby, J; Baatrup, E

    1992-01-01

    The deposition of silver after a single intravenous injection (2 micrograms Ag g-1 body weight) was studied in the testes of Wistar rats 24 h and 1 and 2 weeks after dosing with radiolabelled 110AgNo3 (2 micrograms Ag and 1.2 kBq g-1 body weight). Also, the temporal accumulation of silver during...... the experimental period was monitored in the blood, testes, epididymides, kidney, liver and brain. The subcellular distribution of silver within the testes was demonstrated by using the histochemical technique of autometallography. Silver was cleared rapidly from the blood. After an initial rise, concentrations...

  12. Transfer of European mink (Mustela lutreola) embryos into hybrid recipients.

    Science.gov (United States)

    Amstislavsky, Sergei; Aalto, Jussi; Järvinen, Mikko; Lindeberg, Heli; Valtonen, Maija; Zudova, Galina; Ternovskaya, Yulia

    2004-08-01

    The European mink is considered as a highly endangered Mustelidae species. The objective of this study was to explore the intriguing possibility of embryo transfer from European mink to closely related Mustelidae recipient females. To overcome interspecies pregnancy failure, embryos of European mink (Mustela lutreola) were transferred into hybrid females obtained after mating of European polecat (Mustela putorius) males and European mink (M. lutreola) females and vice versa. A total of 32 blastocysts were surgically flushed from the uteri of nine European mink donors and surgically transferred into six pseudopregnant hybrid recipients. One of the recipients received a single embryo and did not whelp. The remaining five recipients each received five to eight embryos and delivered kits. The overall success rate was 50% (16 kits/32 transferred embryos). For both male and female offspring, the average birth weight was lower in ET group when compared with naturally bred control population of European mink. The postnatal mortality rate was significantly higher in ET group as compared to controls: only 9 of 16 kits survived past the first week. At 10 days of age, the average weight for male offspring from the ET and control groups did not differ, although differences still persisted at this age for female offspring. At 3 months of age, the weight of male and female offspring in the ET group did not differ from European minks born after natural mating. We propose that transfer of European mink embryos to hybrid recipients be considered as a new experimental tool within the framework of ex situ approach conservation of this aboriginal European mustelid.

  13. EUROPEAN AUSTERITY WITHOUT GROWTH? EUROPEAN GROWTH WITHOUT EUROPEAN DEMOCRACY?

    Directory of Open Access Journals (Sweden)

    Montani Guido

    2011-07-01

    Full Text Available The European project is facing a crisis. Citizens no longer understand what the EU is about. Young people and the new ruling class have forgotten the clear message of the European project launched just after the Second World War "No wars ever again among Europeans." The founding fathers of the European Union are mentioned in history textbooks, but today Europe is felt as an irritating bureaucracy. In Europe, peace and economic stability are considered as a natural state, a gift from above. Why keep a useless EU alive? The state of the European Union is swiftly degenerating. In almost all the member states, the anti-European forces are gaining ground. Populism is not a new ideology and is not necessarily European: let's recall Peronism. In today's Europe populism is the new manifestation of nationalism. In Italy the Lega Nord is in Berlusconi's eurosceptic government. In France, the National Front is endangering UMP's hegemony. In Belgium the rows between the Flemish and the Walloons threatens the state's unity. In the Netherlands, Hungary, the Czech Republic, Austria and Finland, populist forces are either in the government or strongly influencing the government. National-populism is different from the nationalism of the past. De Gaulle's nationalism was an ideology founded on the "grandeur" of France's history and on a certain idea of Europe, which was "l'Europe de patrie", a kind of European unity accepting French leadership in world politics. Today national-populism is a form of micro-nationalism: it opposes the European project but without having a serious alternative. This is why populism is dangerous. Its real goal is not only the breaking down of the European Union but also the disintegration of the old nation states into micro-ethnic states, as what happened in former Yugoslavia.

  14. Silver-hafnium braze alloy

    Science.gov (United States)

    Stephens, Jr., John J.; Hosking, F. Michael; Yost, Frederick G.

    2003-12-16

    A binary allow braze composition has been prepared and used in a bonded article of ceramic-ceramic and ceramic-metal materials. The braze composition comprises greater than approximately 95 wt % silver, greater than approximately 2 wt % hafnium and less than approximately 4.1 wt % hafnium, and less than approximately 0.2 wt % trace elements. The binary braze alloy is used to join a ceramic material to another ceramic material or a ceramic material, such as alumina, quartz, aluminum nitride, silicon nitride, silicon carbide, and mullite, to a metal material, such as iron-based metals, cobalt-based metals, nickel-based metals, molybdenum-based metals, tungsten-based metals, niobium-based metals, and tantalum-based metals. A hermetic bonded article is obtained with a strength greater than 10,000 psi.

  15. Cadmium hazard in silver brazing.

    Science.gov (United States)

    Gan, S L; Tan, S H; Pinnagoda, J; Tan, K T

    1995-03-01

    This study evaluates the usage of cadmium-containing silver brazing alloys in Singapore and the potential cadmium hazard from its use. Of the 137 factories which responded to the survey questionnaire, only 28 (20.4%) carried out brazing. Of these, only 7 factories used cadmium-containing filler alloys. One hundred and six out of 123 workers from one of these factories had cadmium-in-blood concentrations exceeding 10 mcg/l. Thirty-one (29.2%) of the workers with excessive cadmium absorption had urinary beta-2 microglobulin levels exceeding 28 mcg/g creat. Workers in the other factories who were intermittently exposed had cadmium-in-blood concentrations of 10 mcg/l and below.

  16. Tuning Properties in Silver Clusters

    KAUST Repository

    Joshi, Chakra Prasad

    2015-07-09

    The properties of Ag nanoclusters are not as well understood as those of their more precious Au cousins. However, a recent surge in the exploration of strategies to tune the physicochemical characteristics of Ag clusters addresses this imbalance, leading to new insights into their optical, luminescence, crystal habit, metal-core, ligand-shell and environmental properties. In this Perspective, we provide an overview of the latest strategies along with a brief introduction of the theoretical framework necessary to understand the properties of silver nanoclusters and the basis for their tuning. The advances in cluster research and the future prospects presented in this Perspective will eventually guide the next large systematic study of nanoclusters, resulting in a single collection of data similar to the periodic table of elements.

  17. Sealed Cylindrical Silver/Zinc Batteries Project

    Data.gov (United States)

    National Aeronautics and Space Administration — RBC Technologies has significanly improved the cycle life and wet life of silver/zinc battery technology through novel separator and anode formulations. This...

  18. Silver nanoparticles – wolves in sheep's clothing?

    DEFF Research Database (Denmark)

    Foldbjerg, Rasmus; Jiang, Xiumei; Miclaus, Teodora

    2015-01-01

    Silver nanoparticles (Ag NPs) are one of the most widely utilized engineered nanomaterials (ENMs) in commercial products due to their effective antibacterial activity, high electrical conductivity, and optical properties. Therefore, they have been one of the most intensively investigated nanomate...

  19. Silver Sulfadiazine Nanosystems for Burn Therapy

    National Research Council Canada - National Science Library

    Venkataraman, Meenakshi; Nagarsenker, Mangal

    2013-01-01

    The objective of the present study was to formulate stable silver sulfadiazine (SSD) nanosuspensions and nanogels suitable for topical delivery with a view to increase bactericidal activity in burn therapy...

  20. Electrolytic silver ion cell sterilizes water supply

    Science.gov (United States)

    Albright, C. F.; Gillerman, J. B.

    1968-01-01

    Electrolytic water sterilizer controls microbial contamination in manned spacecraft. Individual sterilizer cells are self-contained and require no external power or control. The sterilizer generates silver ions which do not impart an unpleasant taste to water.

  1. Realistic Silver Optical Constants for Plasmonics

    Science.gov (United States)

    Jiang, Yajie; Pillai, Supriya; Green, Martin A.

    2016-07-01

    Silver remains the preferred conductor for optical and near-infrared plasmonics. Many high-profile studies focus exclusively on performance simulation in such applications. Almost invariably, these use silver optical data either from Palik’s 1985 handbook or, more frequently, an earlier Johnson and Christy (J&C) tabulation. These data are inconsistent, making it difficult to ascertain the reliability of the simulations. The inconsistency stems from challenges in measuring representative properties of pristine silver, due to tarnishing on air exposure. We demonstrate techniques, including use of silicon-nitride membranes, to access the full capabilities of multiple-angle, spectrometric-ellipsometry to generate an improved data set, representative of overlayer-protected, freshly-deposited silver films on silicon-nitride and glass.

  2. Silver nasal sprays: misleading Internet marketing.

    Science.gov (United States)

    Gaslin, Michael T; Rubin, Cory; Pribitkin, Edmund A

    2008-04-01

    Long-term use of silver-containing products is associated with a permanent bluish-gray discoloration of the skin known as argyria, but they remain widely available despite several measures by the FDA to regulate them. Several recent case reports have described the occurrence of argyria as a result of using these "natural" products. We used the five most common Internet search engines to find Web sites providing information on silver-containing nasal sprays. Of 49 Web sites analyzed, only 2 (4%) mentioned argyria as a possible complication, although 30 (61%) did caution against long-term use. Eight sites (16%) made specific claims about the health benefits of the product. All 49 sites (100%) provided direct or indirect links to buy silver-containing nasal sprays. We conclude that information about silver-containing nasal sprays on the Internet is misleading and inaccurate. Therefore, otolaryngologists should be aware of the misinformation their patients may be receiving about these products.

  3. Green synthesis of silver nanoparticles using tannins

    Science.gov (United States)

    Raja, Pandian Bothi; Rahim, Afidah Abdul; Qureshi, Ahmad Kaleem; Awang, Khalijah

    2014-09-01

    Colloidal silver nanoparticles were prepared by rapid green synthesis using different tannin sources as reducing agent viz. chestnut (CN), mangrove (MG) and quebracho (QB). The aqueous silver ions when exposed to CN, MG and QB tannins were reduced which resulted in formation of silver nanoparticles. The resultant silver nanoparticles were characterized using UV-Visible, X-ray diffraction (XRD), scanning electron microscopy (SEM/EDX), and transmission electron microscopy (TEM) techniques. Furthermore, the possible mechanism of nanoparticles synthesis was also derived using FT-IR analysis. Spectroscopy analysis revealed that the synthesized nanoparticles were within 30 to 75 nm in size, while XRD results showed that nanoparticles formed were crystalline with face centered cubic geometry.

  4. Clinical spectrum of silver - Russell syndrome

    Directory of Open Access Journals (Sweden)

    Sapna N.K. Varma

    2013-01-01

    Full Text Available Silver - Russell syndrome is a clinically and genetically heterogenous condition characterized by severe intrauterine and postnatal growth retardation, craniofacial disproportion and normal intelligence downward curvature of the corner of the mouth, syndactyly and webbed fingers. Diagnosis of Silver - Russell syndrome remains clinical; no definite etiology or specific tests have been established. In the recent years, it has been shown that more than 38% of patients have hypomethylation in the imprinting control region 1 of 11p15 and one-tenth of patients carry a maternal uniparental disomy of chromosome seven. The pathophysiological mechanisms resulting in the Silver - Russell phenotype remain unknown despite the recent progress in deciphering the molecular defects associated with this condition. This case report describes the clinical features of Silver - Russell syndrome in a father and daughter.

  5. Elastocapillary assembly of silver nanotube forest

    Science.gov (United States)

    Yang, Xin; Pack, Min; Sun, Ying

    2014-11-01

    Nanorods/nanotubes have large surface areas making them promising for applications such as high-performance battery and capacitor electrodes, photovoltaics, and interconnects. In this study, we demonstrate the formation of 3D microarchitectures via elastocapillary self-assembly of silver nanotube forests. Patterned silver nanotube forests of different lengths and diameters are made by inkjet printing of silver nanoinks into nanoporous anodic aluminum oxide membranes. These silver nanotube forests are then self-assembled into ordered microstructures via capillary forces induced by liquid condensation, which is compared with immersing nanotubes directly into a liquid. The effects of length, diameter, and footprint of the nanotube forest on self-assembled patterns are systematically studied. By decreasing the footprint and/or increasing the length of nanotube forest, the stiffness of the nanotube forest decreases, bringing the nanotubes together to form closely packed microstructures.

  6. Genetics Home Reference: Russell-Silver syndrome

    Science.gov (United States)

    ... T, Spengler S, Gogiel M, Begemann M, Elbracht M. Epigenetic and genetic diagnosis of Silver-Russell syndrome. Expert ... PubMed More from Genetics Home Reference Bulletins Rare Disease Day 2018 Darwin Day 2018 February is Age- ...

  7. Anaerobic Toxicity of Cationic Silver Nanoparticles

    Data.gov (United States)

    U.S. Environmental Protection Agency — Toxicity data for the impact of nano-silver on anaerobic degradation. This dataset is associated with the following publication: Gitipour, A., S. Thiel, K. Scheckel,...

  8. Tartu on Eesti Boston / Silver Meikar

    Index Scriptorium Estoniae

    Meikar, Silver, 1978-

    2007-01-01

    Tartu eeldustest kujuneda hariduse, innovaatilise tootmise, pärimuskultuuri ja linnaruumi tasakaalustatud kasutamise südameks. Ettevõtluse, transpordi ja turismi arengust. Lisa: Silver Meikari Lõuna-Eesti edu top 10

  9. Biosynthesis Of Silver Nanoparticles From Marine Seaweed Sargassum Cinereum And Their Antibacterial Activity

    Digital Repository Service at National Institute of Oceanography (India)

    Mohandass, C.; VijayRaj, A.S.; Rajasabapathy, R.; SatheeshBabu, S.; Rao, S.V.; Shiva, C.; De-Mello, I.

    Seaweed extracts of Sargassum cinereum was used as a reducing agent in the eco-friendly extracellular synthesis of silver nanoparticles from an aqueous solution of silver nitrate (AgNO3 ). High conversion of silver ions to silver nanoparticles...

  10. Gold and Silver Extraction from Leach Solutions

    Directory of Open Access Journals (Sweden)

    Bagdaulet K. Kenzhaliyev

    2014-03-01

    Full Text Available There has been carried out an investigation on the extraction of gold and silver from thiosulfate solutions: standard test and technological solutions of chemical and electrochemical leaching. The influence of related metals on the process of extracting gold from solution was studied. There has been conducted a comparative study of the IR spectra of solutions after the sorption of gold, silver and related metals.

  11. Electrocatalytic activity of bismuth doped silver electrodes

    CERN Document Server

    Amjad, M

    2002-01-01

    Investigation of redox reactions on silver, and bismuth doped silver electrodes in aqueous KOH solutions, by using potentiostatic steady-state polarization technique, has been carried out. The redox wave potential and current displacements along with multiplicity of the latter have been examined. These electrodes were employed for the oxidation of organic molecules such as ethylamine in alkaline media. Subsequently, these electrodes were ranked with respect to their activity for the redox reactions. (author)

  12. Realistic Silver Optical Constants for Plasmonics

    OpenAIRE

    Yajie Jiang; Supriya Pillai; Green, Martin A.

    2016-01-01

    Silver remains the preferred conductor for optical and near-infrared plasmonics. Many high-profile studies focus exclusively on performance simulation in such applications. Almost invariably, these use silver optical data either from Palik?s 1985 handbook or, more frequently, an earlier Johnson and Christy (J&C) tabulation. These data are inconsistent, making it difficult to ascertain the reliability of the simulations. The inconsistency stems from challenges in measuring representative prope...

  13. Analysis of normal and transparent silver Teflon

    Science.gov (United States)

    Stuckey, W. K.; Galuska, A. A.; Uht, J.

    1985-01-01

    Samples of Inconel/silver/Teflon exposed to solar radiation, and atomic oxygen on Solar Max were microcharacterized. Those samples exposed to atomic oxygen from the metallic side had become transparent while those exposed from the Teflon side remained reflective. The difference between the transparent and non-transparent material was determined. Microcharacterization of these Inconel/silver/Teflon samples was performed using scanning electron microscopy with windowless energy dispersive X ray analysis, secondary ion mass spectrometry, and X ray photoelectron spectroscopy.

  14. Selective Electroless Silver Deposition on Graphene Edges

    DEFF Research Database (Denmark)

    Durhuus, D.; Larsen, M. V.; Andryieuski, Andrei

    2015-01-01

    We demonstrate a method of electroless selective silver deposition on graphene edges or between graphene islands without covering the surface of graphene. Modifications of the deposition recipe allow for decoration of graphene edges with silver nanoparticles or filling holes in damaged graphene...... on silica substrate and thus potentially restoring electric connectivity with minimal influence on the overall graphene electrical and optical properties. The presented technique could find applications in graphene based transparent conductors as well as selective edge functionalization and can be extended...

  15. In vitro percutaneous penetration and characterization of silver from silver-containing textiles.

    Science.gov (United States)

    Bianco, Carlotta; Kezic, Sanja; Crosera, Matteo; Svetličić, Vesna; Šegota, Suzana; Maina, Giovanni; Romano, Canzio; Larese, Francesca; Adami, Gianpiero

    2015-01-01

    The objective of this study was to determine the in vitro percutaneous penetration of silver and characterize the silver species released from textiles in different layers of full thickness human skin. For this purpose, two different wound dressings and a garment soaked in artificial sweat were placed in the donor compartments of Franz cells for 24 hours. The concentration of silver in the donor phase and in the skin was determined by an electrothermal atomic absorption spectrometer (ET-AAS) and by inductively coupled plasma mass spectrometer (ICP-MS). The characterization of silver species in the textiles and in the skin layers was made by scanning electron microscopy with integrated energy dispersive X-ray spectroscopy (SEM-EDX). Additionally, the size distribution of silver nanoparticles in the textiles was performed by atomic force microscopy (AFM). On the surface of all investigated materials, silver nanoparticles of different size and morphology were found. Released silver concentrations in the soaking solutions (ie, exposure concentration) ranged from 0.7 to 4.7 μg/mL (0.6-4.0 μg/cm(2)), fitting the bactericidal range. Silver and silver chloride aggregates at sizes of up to 1 μm were identified both in the epidermis and dermis. The large size of these particles suggests that the aggregation occurred in the skin. The formation of these aggregates likely slowed down the systemic absorption of silver. Conversely, these aggregates may form a reservoir enabling prolonged release of silver ions, which might lead to local effects.

  16. Engineered Escherichia coli silver-binding periplasmic protein that promotes silver tolerance.

    Science.gov (United States)

    Sedlak, Ruth Hall; Hnilova, Marketa; Grosh, Carolynn; Fong, Hanson; Baneyx, Francois; Schwartz, Dan; Sarikaya, Mehmet; Tamerler, Candan; Traxler, Beth

    2012-04-01

    Silver toxicity is a problem that microorganisms face in medical and environmental settings. Through exposure to silver compounds, some bacteria have adapted to growth in high concentrations of silver ions. Such adapted microbes may be dangerous as pathogens but, alternatively, could be potentially useful in nanomaterial-manufacturing applications. While naturally adapted isolates typically utilize efflux pumps to achieve metal resistance, we have engineered a silver-tolerant Escherichia coli strain by the use of a simple silver-binding peptide motif. A silver-binding peptide, AgBP2, was identified from a combinatorial display library and fused to the C terminus of the E. coli maltose-binding protein (MBP) to yield a silver-binding protein exhibiting nanomolar affinity for the metal. Growth experiments performed in the presence of silver nitrate showed that cells secreting MBP-AgBP2 into the periplasm exhibited silver tolerance in a batch culture, while those expressing a cytoplasmic version of the fusion protein or MBP alone did not. Transmission electron microscopy analysis of silver-tolerant cells revealed the presence of electron-dense silver nanoparticles. This is the first report of a specifically engineered metal-binding peptide exhibiting a strong in vivo phenotype, pointing toward a novel ability to manipulate bacterial interactions with heavy metals by the use of short and simple peptide motifs. Engineered metal-ion-tolerant microorganisms such as this E. coli strain could potentially be used in applications ranging from remediation to interrogation of biomolecule-metal interactions in vivo.

  17. Microchemical investigation of Greek and Roman silver and gold plated coins: coating techniques and corrosion mechanisms

    Science.gov (United States)

    Ingo, G. M.; Balbi, S.; de Caro, T.; Fragalà, I.; Riccucci, C.; Bultrini, G.

    2006-06-01

    Within the framework of a project financially supported by the European Commission (contract Nr. 509126, acronym PROMET) the metallurgical techniques used by Romans and Greeks for coating the copper core of coins with a thin or thick layer of gold or silver are studied by means of the combined use of scanning electron microscopy combined with energy dispersive spectrometry (SEM-EDS) and optical microscopy (OM) techniques. This approach is utilised to gain further insight into the micro-chemical structure of the external regions of the coins as well as into the bulk metallurgical features. The results indicate that several methods were used by the Greek and Roman craftsmen including the mechanical application of a thin malleable gold or silver foils to be welded via thermal treatment. The analytical approach is also used for investigating the corrosion products grown on the coins during the long-term burial and for identifying degradation mechanisms.

  18. Activity of Antimicrobial Silver Polystyrene Nanocomposites

    Directory of Open Access Journals (Sweden)

    M. Palomba

    2012-01-01

    Full Text Available A simple technique based on doping polymers with in situ generated silver nanoparticles (Ag/PS films has been developed. In particular, an antiseptic material has been prepared by dissolving silver 1,5-cyclooctadiene-hexafluoroacetylacetonate in amorphous polystyrene, and the obtained solid solution has been heated for ca. 10 s at a convenient temperature (180°C. Under such conditions the metal precursor decomposes producing silver atoms that diffuse into the polymer and clusterize. The antimicrobial characteristics of the resulting polystyrene-based material have been accurately evaluated toward Escherichia coli (E. coli comparing the cytotoxicity effect of 10 wt.% and 30 wt.% (drastic and mild annealing silver-doped polystyrene to the corresponding pure micrometric silver powder. Two different bacterial viability assays were performed in order to demonstrate the cytotoxic effect of Ag/PS films on cultured E. coli: (1 turbidimetric determination of optical density; (2 BacLight fluorescence-based test. Both methods have shown that silver-doped polystyrene (30 wt.% provides higher antibacterial activity than pure Ag powder, under similar concentration and incubation conditions.

  19. Silver As Antibacterial toward Listeria monocytogenes.

    Science.gov (United States)

    Belluco, Simone; Losasso, Carmen; Patuzzi, Ilaria; Rigo, Laura; Conficoni, Daniele; Gallocchio, Federica; Cibin, Veronica; Catellani, Paolo; Segato, Severino; Ricci, Antonia

    2016-01-01

    Listeria monocytogenes is a serious foodborne pathogen that can contaminate food during processing and can grow during food shelf-life. New types of safe and effective food contact materials embedding antimicrobial agents, like silver, can play an important role in the food industry. The present work aimed at evaluating the in vitro growth kinetics of different strains of L. monocytogenes in the presence of silver, both in its ionic and nano form. The antimicrobial effect was determined by assaying the number of culturable bacterial cells, which formed colonies after incubation in the presence of silver nanoparticles (AgNPs) or silver nitrate (AgNO3). Ionic release experiments were performed in parallel. A different reduction of bacterial viability between silver ionic and nano forms was observed, with a time delayed effect exerted by AgNPs. An association between antimicrobial activity and ions concentration was shown by both silver chemical forms, suggesting the major role of ions in the antimicrobial mode of action.

  20. Blood and Tissue Silver Levels Following Application of Silver-Based Dressings to Sulfur Mustard Chemical Burns.

    Science.gov (United States)

    Barillo, David J; Croutch, Claire R; Reid, Frances; Culley, Tara; Sosna, William; Roseman, Julie

    Silver-based dressings are commonly used in burn care. Silver sulfadiazine use is associated with elevated blood, urine, and tissue levels of silver ion. We examined wound and tissue levels of silver ion in a two-species model of sulfur mustard chemical burn injury treated with two different silver-based dressings. Superficial dermal and moderate thickness dermal chemical burns were induced in 16 hairless guinea pigs and in 16 Gottingen minipigs by exposure to sulfur mustard vapor. After debridement, silver-nylon burn dressings or silver-calcium alginate dressings were applied and changed every 7 days until wound healing or a maximum of 60 days post exposure. At autopsy, liver, spleen, and wound samples were harvested. Silver ion was measured using inductively coupled plasma-mass spectrography with a lower level of detection of 0.02 parts per billion. Negligible silver ion levels were found in the liver (mean burn wound dressings than with silver-calcium alginate dressings. Silver ion could be detected in some wounds 40 days after dressings were removed. In a chemical burn model, application of silver-nylon or silver-calcium alginate dressings is associated with elevated wound levels but negligible tissue levels of silver ion.

  1. Propagation of plasmons in designed single crystalline silver nanostructures

    DEFF Research Database (Denmark)

    Kumar, Shailesh; Lu, Ying-Wei; Huck, Alexander

    2012-01-01

    We demonstrate propagation of plasmons in single crystalline silver nanostructures fabricated using a combination of a bottom-up and a top-down approach. Silver nanoplates of thickness around 65 nm and a surface area of about 100 μm2 are made using a wet chemical method. Silver nanotips and nanow......We demonstrate propagation of plasmons in single crystalline silver nanostructures fabricated using a combination of a bottom-up and a top-down approach. Silver nanoplates of thickness around 65 nm and a surface area of about 100 μm2 are made using a wet chemical method. Silver nanotips...

  2. Effect of gelatin sponge with colloid silver on bone healing in infected cranial defects.

    Science.gov (United States)

    Dong, Yuliang; Liu, Weiqing; Lei, Yiling; Wu, Tingxi; Zhang, Shiwen; Guo, Yuchen; Liu, Yuan; Chen, Demeng; Yuan, Quan; Wang, Yongyue

    2017-01-01

    Oral infectious diseases may lead to bone loss, which makes it difficult to achieve satisfactory restoration. The rise of multidrug resistant bacteria has put forward severe challenges to the use of antibiotics. Silver (Ag) has long been known as a strong antibacterial agent. In clinic, gelatin sponge with colloid silver is used to reduce tooth extraction complication. To investigate how this material affect infected bone defects, methicillin-resistant Staphylococcus aureus (MRSA) infected 3-mm-diameter cranial defects were created in adult female Sprague-Dawley rats. One week after infection, the defects were debrided of all nonviable tissue and then implanted with gelatin sponge with colloid silver (gelatin/Ag group) or gelatin alone (gelatin group). At 2 and 3days after debridement, significantly lower mRNA expression levels of IL-6 and TNF-α and lower plate colony count value were detected in gelatin/Ag group than control. Micro-CT analysis showed a significant increase of newly formed bone volume fraction (BV/TV) in gelatin/Ag treated defects. The HE stained cranium sections also showed a faster rate of defect closure in gelatin/Ag group than control. These findings demonstrated that gelatin sponge with colloid silver can effectively reduce the infection caused by MRSA in cranial defects and accelerate bone healing process. Copyright © 2016. Published by Elsevier B.V.

  3. Relaxation of the silver/silver iodide electrode in aqueous solution

    NARCIS (Netherlands)

    Peverelli, K.J.

    1979-01-01

    The aim of this study is to detect and characterize relaxation processes on silver/silver iodide electrodes in aqueous electrolyte solution. The information obtained is to be used for an estimation of the consequences of similar processes on colloidal AgI

  4. The safety of nanocrystalline silver dressings on burns: a study of systemic silver absorption.

    Science.gov (United States)

    Vlachou, Evangelia; Chipp, Elizabeth; Shale, Elizabeth; Wilson, Yvonne T; Papini, Remo; Moiemen, Naiem S

    2007-12-01

    Wound dressings containing silver have been in widespread use for many years. However, there are few quantitative data on the systemic absorption of silver or whether there is associated clinical risk. To assess systemic silver levels when Acticoat dressings containing nanocrystalline silver were used, and to determine whether increases in such levels were associated with haematological or biochemical indicators of toxicity. A prospective, single-centre, open-label study of 30 patients with relatively small burns that required skin grafting. Serum silver levels were measured before, during and at discontinuation of the use of the Acticoat dressings, and again at 3 and 6 months following completion of treatment. The median total postoperative wound size was 12% of the total body surface area. The median time to maximum silver levels was 9 days. The median maximum serum silver level was 56.8 microg/l. The median serum level at 6 months was 0.8 microg/l. There were no haematological or biochemical indicators of toxicity associated with the silver absorption observed in this study. This study has confirmed our view that Acticoat products are safe for use on burns and they remain a standard part of treatment at our centre.

  5. Preparation of sintered silver nanosheets by coating technique using silver carbamate complex

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Hee-Yong; Cha, Jae-Ryung; Gong, Myoung-Seon, E-mail: msgong@dankook.ac.kr

    2015-03-01

    This study describes a coating technique approach for large-scale preparation of sintered silver nanosheets whose lateral dimensions were controlled in the thickness range of 50–65 nm. These procedures involved coating water-soluble poly (vinyl alcohol) (PVA) and silver 2-ethylhexylcarbamate (Ag-EHC), as well as thermal reduction of a silver precursor by heating at 150 °C, followed by dissolving away the PVA layer with alcoholic water. When the silver carbamate layer on the PVA layer was heated to 150 °C, the silver carbamate layer was thermally reduced and directed to grow into uniform sintered nanosheets with aspect ratios as high as 1000. The multi-stacked PVA/Ag structures and sintered silver nanosheets were confirmed by scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. Measurements of the conductive property at room temperature indicated that these nanosheets were electrically continuous with a resistivity of approximately 7.3 × 10{sup −6} Ω cm. - Highlights: • A coating technique is used to make sintered Ag nanosheets. • PVA and silver carbamate act as a separation layer and a silver precursor. • The Ag nanosheets have thickness width 50–60 nm and width up to hundred μm. • The Ag nanosheets showed a resistivity of ca. 7.3 × 10{sup −6} Ω cm.

  6. Silver Recovery and Power Generation from Ammonia Chelated Silver Solution in a Bio-Electrochemical Reactor

    Science.gov (United States)

    Ho, N. A. D.; Babel, S.

    2017-06-01

    Silver has valuable features and limited availability, and thus recovery from wastewater or aqueous solutions plays an important role in environmental protection and economic profits. In this study, silver recovery along with power generation and COD removal were investigated in a bio-electrochemical system (BES). The BES comprised of an anode and a cathode chamber which were separated by a cation exchange membrane to prevent the cross-over of electrolytes. During the biological oxidation of acetate as an electron donor in the anode chamber, the reduction of ammonia chelated silver ions as electron acceptors in the cathode side occurred spontaneously. Results showed that a silver recovery of 99% and COD removal efficiency of 60% were achieved at the initial silver concentration of 1,000 mg/L after 48 hours of operation. The power generation improved 4.66%, from 3,618 to 3,795 mW/m3, by adding NaNO3 of 850 mg/L to the catholyte containing 2,000 mg/L of silver ions. Deposits on the cathode surface were characterized using scanning electron microscope (SEM) and energy dispersive X-ray (EDX). Metallic silver with dendritic structures and high purity were detected. This study demonstrated that BES technology can be employed to recover silver from complex chelating solution, produce electricity, and treat wastewater.

  7. In vitro percutaneous penetration and characterization of silver from silver-containing textiles

    NARCIS (Netherlands)

    Bianco, Carlotta; Kezic, Sanja; Crosera, Matteo; Svetličić, Vesna; Šegota, Suzana; Maina, Giovanni; Romano, Canzio; Larese, Francesca; Adami, Gianpiero

    2015-01-01

    The objective of this study was to determine the in vitro percutaneous penetration of silver and characterize the silver species released from textiles in different layers of full thickness human skin. For this purpose, two different wound dressings and a garment soaked in artificial sweat were

  8. Combined use of SEM-EDS, OM and XRD for the characterization of corrosion products grown on silver roman coins

    Science.gov (United States)

    Ingo, G. M.; Balbi, S.; de Caro, T.; Fragalà, I.; Angelini, E.; Bultrini, G.

    2006-06-01

    In the framework of the PROMET project (European Commission contract No. 509126) aimed to develop new analytical techniques and materials for monitoring and protecting metal artefacts and monuments from the Mediterranean region, the corrosion products grown on silver Roman coins during archaeological burial is studied by means of scanning electron microscopy combined with energy dispersive spectrometry (SEM-EDS), X-ray diffraction (XRD) and optical microscopy (OM) techniques.

  9. Normal Female Reproductive Anatomy

    Science.gov (United States)

    ... historical Searches are case-insensitive Reproductive System, Female, Anatomy Add to My Pictures View /Download : Small: 720x756 ... Large: 3000x3150 View Download Title: Reproductive System, Female, Anatomy Description: Anatomy of the female reproductive system; drawing ...

  10. 'Peony Nebula' Star Settles for Silver Medal

    Science.gov (United States)

    2008-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Poster Version Movie If our galaxy, the Milky Way, were to host its own version of the Olympics, the title for the brightest known star would go to a massive star called Eta Carina. However, a new runner-up now the second-brightest star in our galaxy has been discovered in the galaxy's dusty and frenzied interior. This image from NASA's Spitzer Space Telescope shows the new silver medalist, circled in the inset above, in the central region of our Milky Way. Dubbed the 'Peony nebula' star, this blazing ball of gas shines with the equivalent light of 3.2 million suns. The reigning champ, Eta Carina, produces the equivalent of 4.7 million suns worth of light though astronomers say these estimates are uncertain, and it's possible that the Peony nebula star could be even brighter than Eta Carina. If the Peony star is so bright, why doesn't it stand out more in this view? The answer is dust. This star is located in a very dusty region jam packed with stars. In fact, there could be other super bright stars still hidden deep in the stellar crowd. Spitzer's infrared eyes allowed it to pierce the dust and assess the Peony nebula star's true brightness. Likewise, infrared data from the European Southern Observatory's New Technology Telescope in Chile were integral in calculating the Peony nebula star's luminosity. The Peony nebula, which surrounds the Peony nebular star, is the reddish cloud of dust in and around the white circle. The movie begins by showing a stretch of the dusty and frenzied central region of our Milky Way galaxy. It then zooms in to reveal the 'Peony nebula' star the new second-brightest star in the Milky Way, discovered in part by NASA's Spitzer Space Telescope. This is a three-color composite showing infrared observations from two Spitzer instruments. Blue represents 3.6-micron light and green shows light of 8 microns, both captured by Spitzer's infrared array

  11. Novel Nanohybrids of Silver Particles on Clay Platelets for Inhibiting Silver-Resistant Bacteria

    Science.gov (United States)

    Su, Hong-Lin; Lin, Siou-Hong; Wei, Jiun-Chiou; Pao, I-Chuan; Chiao, Shu-Her; Huang, Chieh-Chen; Lin, Shinn-Zong; Lin, Jiang-Jen

    2011-01-01

    We develop a novel nanohybrid showing a strong antibacterial activity on all of the tested pathogens, including methicillin-resistant Staphylococcus auerus and silver-resistant E. coli. The nanohybrid consists of silver nanoparticles (AgNPs) supported on 1 nm-thick silicate platelets (NSPs). The AgNP/NSP nanohybrid enables to encapsulate bacteria and triggers death signals from the cell membrane. The geographic shape of the NSPs concentrates AgNPs but impedes their penetration into attached cells, mitigating the detrimental effect of silver ion deposition in applied tissues. Moreover, the tightly tethered AgNPs on NSP surface achieve a stronger biocidal effect than silver nitrate, but bypassing Ag+ mechanism, on silver-resistant bacteria. This nanohybrid presents an effective and safe antimicrobial agent in a new perspective. PMID:21695045

  12. Novel nanohybrids of silver particles on clay platelets for inhibiting silver-resistant bacteria.

    Directory of Open Access Journals (Sweden)

    Hong-Lin Su

    Full Text Available We develop a novel nanohybrid showing a strong antibacterial activity on all of the tested pathogens, including methicillin-resistant Staphylococcus auerus and silver-resistant E. coli. The nanohybrid consists of silver nanoparticles (AgNPs supported on 1 nm-thick silicate platelets (NSPs. The AgNP/NSP nanohybrid enables to encapsulate bacteria and triggers death signals from the cell membrane. The geographic shape of the NSPs concentrates AgNPs but impedes their penetration into attached cells, mitigating the detrimental effect of silver ion deposition in applied tissues. Moreover, the tightly tethered AgNPs on NSP surface achieve a stronger biocidal effect than silver nitrate, but bypassing Ag(+ mechanism, on silver-resistant bacteria. This nanohybrid presents an effective and safe antimicrobial agent in a new perspective.

  13. Silver nanoparticles from silver halide photography to plasmonics

    CERN Document Server

    Tani, Tadaaki

    2015-01-01

    This book provides systematic knowledge and ideas on nanoparticles of Ag and related materials. While Ag and metal nanoparticles are essential for plasmonics, silver halide (AgX) photography relies to a great extent on nanoparticles of Ag and AgX which have the same crystal structure and have been studied extensively for many years. This book has been written to combine the knowledge of nanoparticles of Ag and related materials in plasmonics and AgX photography in order to provide new ideas for metal nanoparticles in plasmonics. Chapters 1–3 of this book describe the structure and formation of nanoparticles of Ag and related materials. Systematic descriptions of the structure and preparation of Ag, Au, and noble-metal nanoparticles for plasmonics are followed by and related to those of nanoparticles of Ag and AgX in AgX photography. Knowledge of the structure and preparation of Ag and AgX nanoparticles in photography covers nanoparticles with widely varying sizes, shapes, and structures, and formation proce...

  14. Glass frits coated with silver nanoparticles for silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yingfen, E-mail: lyf350857423@163.com; Gan, Weiping; Zhou, Jian; Li, Biyuan

    2015-06-30

    Graphical abstract: - Highlights: • Silver-coated glass frits for solar cells were prepared by electroless plating. • Gum Arabic was used as the activating agent of glass frits. • Silver-coated glass frits can improve the photovoltaic performances of solar cells. - Abstract: Glass frits coated with silver nanoparticles were prepared by electroless plating. Gum Arabic (GA) was used as the activating agent of glass frits without the assistance of stannous chloride or palladium chloride. The silver-coated glass frits prepared with different GA dosages were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA). The characterization results indicated that silver-coated glass frits had the structures of both glass and silver. Spherical silver nanoparticles were distributed on the glass frits evenly. The density and particle size of silver nanoparticles on the glass frits can be controlled by adjusting the GA dosage. The silver-coated glass frits were applied to silver pastes to act as both the densification promoter and silver crystallite formation aid in the silver electrodes. The prepared silver-coated glass frits can improve the photovoltaic performances of solar cells.

  15. Silver, gold, and alloyed silver-gold nanoparticles: characterization and comparative cell-biologic action

    Energy Technology Data Exchange (ETDEWEB)

    Mahl, Dirk; Diendorf, Joerg; Ristig, Simon [University of Duisburg-Essen, Department of Inorganic Chemistry, Center for Nanointegration Duisburg-Essen (CeNIDE) (Germany); Greulich, Christina [Ruhr-University of Bochum, Bergmannsheil University Hospital/Surgical Research (Germany); Li Zian; Farle, Michael [University of Duisburg-Essen, Faculty of Physics, Center for Nanointegration Duisburg-Essen (CeNIDE) (Germany); Koeller, Manfred [Ruhr-University of Bochum, Bergmannsheil University Hospital/Surgical Research (Germany); Epple, Matthias, E-mail: matthias.epple@uni-due.de [University of Duisburg-Essen, Department of Inorganic Chemistry, Center for Nanointegration Duisburg-Essen (CeNIDE) (Germany)

    2012-10-15

    Silver, gold, and silver-gold-alloy nanoparticles were prepared by citrate reduction modified by the addition of tannin during the synthesis, leading to a reduction in particle size by a factor of three. Nanoparticles can be prepared by this easy water-based synthesis and subsequently functionalized by the addition of either tris(3-sulfonatophenyl)phosphine or poly(N-vinylpyrrolidone). The resulting nanoparticles of silver (diameter 15-25 nm), gold (5-6 nm), and silver-gold (50:50; 10-12 nm) were easily dispersable in water and also in cell culture media (RPMI + 10 % fetal calf serum), as shown by nanoparticle tracking analysis and differential centrifugal sedimentation. High-resolution transmission electron microscopy showed a polycrystalline nature of all nanoparticles. EDX on single silver-gold nanoparticles indicated that the concentration of gold is higher inside a nanoparticle. The biologic action of the nanoparticles toward human mesenchymal stem cells (hMSC) was different: Silver nanoparticles showed a significant concentration-dependent influence on the viability of hMSC. Gold nanoparticles showed only a small effect on the viability of hMSC after 7 days. Surprisingly, silver-gold nanoparticles had no significant influence on the viability of hMSC despite the silver content. Silver nanoparticles and silver-gold nanoparticles in the concentration range of 5-20 {mu}g mL{sup -1} induced the activation of hMSC as indicated by the release of IL-8. In contrast, gold nanoparticles led to a reduction of the release of IL-6 and IL-8.

  16. Synthesis and characterization of silver nanoparticles from (bis)alkylamine silver carboxylate precursors

    Science.gov (United States)

    Uznanski, Pawel; Zakrzewska, Joanna; Favier, Frederic; Kazmierski, Slawomir; Bryszewska, Ewa

    2017-03-01

    A comparative study of amine and silver carboxylate adducts [R1COOAg-2(R2NH2)] (R1 = 1, 7, 11; R2 = 8, 12) as a key intermediate in NPs synthesis is carried out via differential scanning calorimetry, solid-state FT-infrared spectroscopy, 13C CP MAS NMR, powder X-ray diffraction and X-ray photoelectron spectroscopy, and various solution NMR spectroscopies (1H and 13C NMR, pulsed field gradient spin-echo NMR, and ROESY). It is proposed that carboxyl moieties in the presence of amine ligands are bound to silver ions via chelating bidentate type of coordination as opposed to bridging bidentate coordination of pure silver carboxylates resulting from the formation of dimeric units. All complexes are packed as lamellar bilayer structures. Silver carboxylate/amine complexes show one first-order melting transition. The evidence presented in this study shows that phase behavior of monovalent metal carboxylates are controlled, mainly, by head group bonding. In solution, insoluble silver salt is stabilized by amine molecules which exist in dynamic equilibrium. Using (bis)amine-silver carboxylate complex as precursor, silver nanoparticles were fabricated. During high-temperature thermolysis, the (bis)amine-carboxylate adduct decomposes to produce silver nanoparticles of small size. NPs are stabilized by strongly interacting carboxylate and trace amounts of amine derived from the silver precursor interacting with carboxylic acid. A corresponding aliphatic amide obtained from silver precursor at high-temperature reaction conditions is not taking part in the stabilization. Combining NMR techniques with FTIR, it was possible to follow an original stabilization mechanism.

  17. Synthesis and characterization of silver nanoparticles from (bis)alkylamine silver carboxylate precursors

    Energy Technology Data Exchange (ETDEWEB)

    Uznanski, Pawel, E-mail: puznansk@cbmm.lodz.pl; Zakrzewska, Joanna [Centre of Molecular and Macromolecular Studies, PAS (Poland); Favier, Frederic, E-mail: fredf@univ-montp2.fr [Université Montpellier II, ICGM - UMR5253- Equipe AIME (France); Kazmierski, Slawomir; Bryszewska, Ewa [Centre of Molecular and Macromolecular Studies, PAS (Poland)

    2017-03-15

    A comparative study of amine and silver carboxylate adducts [R{sub 1}COOAg-2(R{sub 2}NH{sub 2})] (R{sub 1} = 1, 7, 11; R{sub 2} = 8, 12) as a key intermediate in NPs synthesis is carried out via differential scanning calorimetry, solid-state FT-infrared spectroscopy, {sup 13}C CP MAS NMR, powder X-ray diffraction and X-ray photoelectron spectroscopy, and various solution NMR spectroscopies ({sup 1}H and {sup 13}C NMR, pulsed field gradient spin-echo NMR, and ROESY). It is proposed that carboxyl moieties in the presence of amine ligands are bound to silver ions via chelating bidentate type of coordination as opposed to bridging bidentate coordination of pure silver carboxylates resulting from the formation of dimeric units. All complexes are packed as lamellar bilayer structures. Silver carboxylate/amine complexes show one first-order melting transition. The evidence presented in this study shows that phase behavior of monovalent metal carboxylates are controlled, mainly, by head group bonding. In solution, insoluble silver salt is stabilized by amine molecules which exist in dynamic equilibrium. Using (bis)amine-silver carboxylate complex as precursor, silver nanoparticles were fabricated. During high-temperature thermolysis, the (bis)amine-carboxylate adduct decomposes to produce silver nanoparticles of small size. NPs are stabilized by strongly interacting carboxylate and trace amounts of amine derived from the silver precursor interacting with carboxylic acid. A corresponding aliphatic amide obtained from silver precursor at high-temperature reaction conditions is not taking part in the stabilization. Combining NMR techniques with FTIR, it was possible to follow an original stabilization mechanism.

  18. Educating in European Identity?

    National Research Council Canada - National Science Library

    Enrique Banús

    2007-01-01

    In the last decades, the claim for a "European identity" has been manifested sometimes as a solution for the citizens' distance to the European project, sometimes also as a precondition for a further...

  19. Polypyrrole-silver Nanocomposite: Synthesis and Characterization

    Directory of Open Access Journals (Sweden)

    D. M. Nerkar

    2016-07-01

    Full Text Available Polypyrrole-Silver (PPy-Ag nanocomposite has been successfully synthesized by the chemical oxidative polymerization of pyrrole with iron (III chloride as an oxidant, in the presence of a colloidal suspension of silver nanoparticles. Turkevich method (Citrate reduction method was used for the synthesis of silver nanoparticles (Ag NPs. The silver nanoparticles were characterized by UV-Visible spectroscopy which showed an absorption band at 423 nm confirming the formation of nanoparticles. PPy-Ag nanocomposite was characterized by Transmission Electron Microscopy (TEM, Scanning Electron Microscopy (SEM, Fourier Transform Infrared Spectroscopy (FTIR and X-ray diffraction (XRD techniques for morphological and structural confirmations. TEM and SEM images revealed that the silver nanoparticles were well dispersed in the PPy matrix. XRD pattern showed that PPy is amorphous but the presence of the peaks at 2q values of 38.24°, 44.57°, 64.51° and 78.45° corresponding to a cubic phase of silver, revealed the incorporation of silver nanoparticles in the PPy matrix. A possible formation mechanism of PPy-Ag nanocomposite was also proposed. The electrical conductivity of PPy-Ag nanocomposite was studied using two probe method. The electrical conductivity of the PPy-Ag nanocomposite prepared was found to be 4.657´10- 2 S/cm, whereas that of pure PPy was found to be 9.85´10-3 S/cm at room temperature (303 K. The value of activation energy (Ea for pure PPy was 0.045 eV while it decreased to 0.034 eV for PPy-Ag nanocomposite. The synthesized nanocomposite powder can be utilized as a potential material for fabrication of gas sensors operating at room temperature.

  20. The female reproductive cycle of the european common carp ...

    African Journals Online (AJOL)

    1982); Hanyu, Asahima & Shimizu. (1982) and Richter, Eding, Leuven & van der Wijst (1982) showed that photoperiod and environmental temperature are amongst the major factors affecting the breeding cycle. These and other related physical ...

  1. The female reproductive cycle of the european common carp ...

    African Journals Online (AJOL)

    The annual reproductive cycle of Cyprinus carpio was investigated using morphometric parameters of the body and gonads, including fecundity estimations, gonadosomatic indexes as well as histological evaluation and classification of oocyte developmental stages. It was concluded the C. carpio has an extended ...

  2. Behaviour and passage of European silver eels (Anguilla anguilla at a small hydropower plant during their downstream migration Comportement et passage de l’anguille argentée (Anguilla anguilla au niveau d’une petite centrale hydroélectrique lors de sa migration de dévalaison

    Directory of Open Access Journals (Sweden)

    De-Oliveira E.

    2010-09-01

    Full Text Available Between 2004 and 2007, 116 downstream migrant silver eels (Anguilla anguilla were monitored at a hydropower plant on the Gave de Pau river in South-West France using radio and PIT telemetry. The objectives of the study were: (i to determine the environmental conditions when eels arrived and passed the facility; (ii to determine the rate of eel escapement (passage other than via the turbines; (iii to describe the behaviour of eels faced with the intake structure and the permeability of the intake trashracks for the different sizes of eel; and (iv to determine whether surface bypasses originally designed for salmon could be effective for eels. Five types of behaviour of silver eels in the forebay and at the plant intakes were identified. The study showed the key factor influencing both eel behaviour and the route taken through the plant was variation in river discharge. Escapement rate was related to eel length and the spill flow to river flow ratio, which could be described by a logistic regression model. The surface bypasses originally designed for salmon were found to aid downstream eel migration significantly. At velocities < 0.40 m·s−1, no eels, even the largest, for which the racks are a physical barrier, were found impinged on the trashracks. De 2004 à 2007, une étude sur la migration de dévalaison de l’anguille argentée européenne (Anguilla anguilla a été menée sur la centrale hydroélectrique de Baigts sur le Gave de Pau dans le Sud-Ouest de la France. Cette étude, au cours de laquelle 116 individus ont été suivis par télémétrie PIT et radio, avait pour objectifs : (i de déterminer les conditions de milieu propices à l’arrivée sur site et au franchissement de l’aménagement; (ii de déterminer les taux d’échappement (passages par des voies autres que les turbines; (iii d’analyser le comportement des anguilles devant les ouvrages et la perméabilité des grilles de la prise d’eau en fonction de la taille

  3. Silver nitrate masquerading as a radiopaque foreign body.

    Science.gov (United States)

    Healy, Claragh; Canney, Mark; Murphy, Adrian; Regan, Padraic

    2007-04-01

    Silver nitrate is commonly used as a method of chemical cauterization to areas of hypergranulation. We report two cases wherein silver nitrate in the hand was misinterpreted radiologically as foreign bodies.

  4. Electrical properties of silver selenide thin films prepared by reactive ...

    Indian Academy of Sciences (India)

    Unknown

    2001-07-29

    805 Å. Keywords. Thin film; silver selenide; reactive evaporation; electrical conductivity. 1. Introduction. Silver selenide attracts the interest of researchers because of its application in the switching devices. The binary and ternary ...

  5. Green biosynthesis of silver nanoparticles using Curcuma longa tuber powder

    National Research Council Canada - National Science Library

    Shameli, Kamyar; Ahmad, Mansor Bin; Zamanian, Ali; Sangpour, Parvanh; Shabanzadeh, Parvaneh; Abdollahi, Yadollah; Zargar, Mohsen

    2012-01-01

    .... In this study, silver nanoparticles were biosynthesized from aqueous silver nitrate through a simple and eco-friendly route using Curcuma longa tuber-powder extracts, which acted as a reductant...

  6. DNA-Mediated Morphological Control of Silver Nanoparticles.

    Science.gov (United States)

    Li, Jiuxing; Zhu, Zhi; Liu, Fang; Zhu, Bingqing; Ma, Yanli; Yan, Jinmao; Lin, Bingqian; Ke, Guoliang; Liu, Rudi; Zhou, Leiji; Tu, Song; Yang, Chaoyong

    2016-10-01

    It is demonstrated that DNA can be used to control the synthesis of silver nanoplates with different morphologies using spherical silver seeds. UV-vis spectroscopy, transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy are used to characterize the synthesized nanoparticles. Silver nanoprisms are encoded by poly C and poly G, while silver flower bouquets and silver nanodiscs are synthesized using poly A and poly T, respectively. The length of DNA is found to have little effect on the morphology of silver nanoparticles. Moreover, the synthesized silver nanoplates are found to have high surface enhanced Raman scattering enhancement ability, good antibacterial activity, and good biocompatibility. These discoveries will broaden the application of DNA in nanoscience and will provide a new platform to investigate the interaction between DNA sequences and silver nanoparticles. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Silver-catalyzed synthesis of amides from amines and aldehydes

    Science.gov (United States)

    Madix, Robert J; Zhou, Ling; Xu, Bingjun; Friend, Cynthia M; Freyschlag, Cassandra G

    2014-11-18

    The invention provides a method for producing amides via the reaction of aldehydes and amines with oxygen adsorbed on a metallic silver or silver alloy catalyst. An exemplary reaction is shown in Scheme 1: (I), (II), (III). ##STR00001##

  8. Functional finishing of cotton fabrics using silver nanoparticles.

    Science.gov (United States)

    Vigneshwaran, N; Kathe, A A; Varadarajan, P V; Nachane, R P; Balasubramanya, R H

    2007-06-01

    We have reported a novel in situ synthesis protocol for silver nanoparticles onto cotton fabrics. Here, cotton fabric immersed in silver nitrate solution is autoclaved at 15 psi, 121 degrees C for 15 min. At this temperature and pressure, the aldehyde terminal of starch (residual size material on cotton fabric) reduced the silver nitrate to silver metal and simultaneously stabilized the nanoparticles on fabric itself. The UV-visible absorption spectrum of both cotton fabrics and bath solution showed a typical absorption peak at 420 nm corresponding to the surface plasmon resonance of silver nanoparticles. With the help of transmission electron micrographs, the average size of the dislodged silver nanoparticles in water is calculated to be 20.9 +/- 13.7 nm. This silver nanoparticles impregnated cotton fabrics showed excellent antibacterial activity against Staphylococcus aureus and bacteriostasis activity against Klebsiella pneumoniae. Also, silver nanoparticles impregnated fabrics expressed significant UV-protection capability in comparison with the untreated fabrics.

  9. Sintered silver joints via controlled topography of electronic packaging subcomponents

    Science.gov (United States)

    Wereszczak, Andrew A.

    2014-09-02

    Disclosed are sintered silver bonded electronic package subcomponents and methods for making the same. Embodiments of the sintered silver bonded EPSs include topography modification of one or more metal surfaces of semiconductor devices bonded together by the sintered silver joint. The sintered silver bonded EPSs include a first semiconductor device having a first metal surface, the first metal surface having a modified topography that has been chemically etched, grit blasted, uniaxial ground and/or grid sliced connected to a second semiconductor device which may also include a first metal surface with a modified topography, a silver plating layer on the first metal surface of the first semiconductor device and a silver plating layer on the first metal surface of the second semiconductor device and a sintered silver joint between the silver plating layers of the first and second semiconductor devices which bonds the first semiconductor device to the second semiconductor device.

  10. Ink composition for making a conductive silver structure

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Steven B.; Lewis, Jennifer A.

    2016-10-18

    An ink composition for making a conductive silver structure comprises a silver salt and a complex of (a) a complexing agent and a short chain carboxylic acid or (b) a complexing agent and a salt of a short chain carboxylic acid, according to one embodiment. A method for making a silver structure entails combining a silver salt and a complexing agent, and then adding a short chain carboxylic acid or a salt of the short chain carboxylic acid to the combined silver salt and a complexing agent to form an ink composition. A concentration of the complexing agent in the ink composition is reduced to form a concentrated formulation, and the silver salt is reduced to form a conductive silver structure, where the concentrated formulation and the conductive silver structure are formed at a temperature of about 120.degree. C. or less.

  11. Biosynthesis of silver nanoparticles by Aspergillus niger , Fusarium ...

    African Journals Online (AJOL)

    ... scanning electron microscope (SEM). Results indicate the synthesis of silver nanoparticles in the reaction mixture. The synthesis of nanoparticles would be suitable for developing a microbial nanotechnology biosynthesis process for mass scale production. Keywords: Silver nanoparticles, biosynthesis, fungi, Aspergillus.

  12. In vivo comparisons of silver nanoparticle and silver ion transport after intranasal delivery in mice.

    Science.gov (United States)

    Falconer, Jonathan L; Grainger, David W

    2017-10-20

    Silver nanoparticles (AgNPs) are widely available as consumer goods, and over-the-counter or nutraceutical products used for alleged therapeutic and antibacterial properties. Among these products, AgNP topical therapy is proposed for treating patients with upper airway bacterial rhinosinusitis. While silver ion release from AgNPs in biological systems is well known, limited investigations actually characterize this silver ion release and their subsequent biological effects distinct from delivered particulate metallic silver. This is in part due to the analytical complexity and difficulty involved in distinguishing silver ion release from metallic AgNPs in biological media. Therefore, this study compared intranasal administration of AgNPs versus soluble silver ion (AgNO3) control to examine their transport and biological differences in tissues. First, we compared bactericidal activities of AgNPs and AgNO3 in those bacteria commonly associated with clinical rhinosinusitis in vitro. Next, we evaluated silver residence time in the sinus cavity after intranasal delivery of AgNPs and AgNO3 to mice, and characterized tissue distribution of silver in the sinonasal mucosal epithelium. We found that AgNPs show reduced bactericidal activity compared to AgNO3 (i.e., MBC of 15ppm compared to 5ppm), and significantly lower residence times in the sinus cavity (AgNP concentrations of 3.76ppm after 3h compared to 9ppm for AgNO3). AgNPs were not readily taken up into or through respiratory epithelium, with very low silver levels found in blood and no detectable silver measured in the olfactory bulb and brain. Results indicate that limited tissue distribution of silver detected from AgNPs is due to AgNP dissolution to silver ion. AgNPs therefore demonstrate adequate safety through limited penetration and absorption, but limited potential therapeutic efficacy as antimicrobials in nasal applications, as concentrations of silver in the sinus cavity drop below the minimum bactericidal

  13. Silver Nanoparticles and Mitochondrial Interaction

    Directory of Open Access Journals (Sweden)

    Eriberto Bressan

    2013-01-01

    Full Text Available Nanotechnology has gone through a period of rapid growth, thus leading to the constant increase in the application of engineered nanomaterials in daily life. Several different types of nanoparticles have been engineered to be employed in a wide array of applications due to their high surface to volume ratio that leads to unique physical and chemical properties. So far, silver nanoparticles (AgNps have been used in many more different medical devices than any other nanomaterial, mainly due to their antimicrobial properties. Despite the promising advantages posed by using AgNps in medical applications, the possible health effects associated with the inevitable human exposure to AgNps have raised concerns as to their use since a clear understanding of their specific interaction with biological systems has not been attained yet. In light of such consideration, aim of the present work is the morphological analysis of the intracellular behavior of AgNps with a diameter of 10 nm, with a special attention to their interaction with mitochondria.

  14. Multifunctionality of silver closo-boranes

    Science.gov (United States)

    Paskevicius, Mark; Hansen, Bjarne R. S.; Jørgensen, Mathias; Richter, Bo; Jensen, Torben R.

    2017-04-01

    Silver compounds share a rich history in technical applications including photography, catalysis, photocatalysis, cloud seeding and as antimicrobial agents. Here we present a class of silver compounds (Ag2B10H10 and Ag2B12H12) that are semiconductors with a bandgap at 2.3 eV in the green visible light spectrum. The silver boranes have extremely high ion conductivity and dynamic-anion facilitated Ag+ migration is suggested based on the structural model. The ion conductivity is enhanced more than two orders of magnitude at room temperature (up to 3.2 mS cm-1) by substitution with AgI to form new compounds. Furthermore, the closo-boranes show extremely fast silver nano-filament growth when excited by electrons during transmission electron microscope investigations. Ag nano-filaments can also be reabsorbed back into Ag2B12H12. These interesting properties demonstrate the multifunctionality of silver closo-boranes and open up avenues in a wide range of fields including photocatalysis, solid state ionics and nano-wire production.

  15. Characterization of antibacterial silver coated yarns.

    Science.gov (United States)

    Pollini, M; Russo, M; Licciulli, A; Sannino, A; Maffezzoli, A

    2009-11-01

    Surface treatments of textile fibers and fabrics significantly increase their performances for specific biomedical applications. Nowadays, silver is the most used antibacterial agent with a number of advantages. Among them, it is worth to note the high degree of biocompatibility, an excellent resistance to sterilization conditions, antibacterial properties with respect to different bacteria associated with a long-term of antibacterial efficiency. However, there are only a few antibacterial fibres available, mainly synthetic with high production cost and limited effectiveness. Cotton yarns with antimicrobial properties are most suitable for wound healing applications and other medical treatments thanks to their excellent moisture absorbance while synthetic based fibres are most suitable for industrial applications such as automotive tapestry and air filters. The silver-coated fibers were developed applying an innovative and low cost silver deposition technique for natural and synthetic fibers or yarns. The structure and morphology of the silver nanoclusters on the fibers was observed by scanning electron microscopy (SEM), atomic force microscopy analysis (AFM) and XRD analysis, and quantitatively confirmed by thermogravimetric analysis (TGA) measurements. Good silver coating stability has been confirmed performing several industrial washing. Antimicrobial tests with Escherichia coli were performed.

  16. Complex conductivity response to silver nanoparticles in ...

    Science.gov (United States)

    The increase in the use of nanoscale materials in consumer products has resulted in a growing concern of their potential hazard to ecosystems and public health from their accidental or intentional introduction to the environment. Key environmental, health, and safety research needs include knowledge and methods for their detection, characterization, fate, and transport. Specifically, techniques available for the direct detection and quantification of their fate and transport in the environment are limited. Their small size, high surface area to volume ratio, interfacial, and electrical properties make metallic nanoparticles, such as silver nanoparticles, good targets for detection using electrical geophysical techniques. Here we measured the complex conductivity response to silver nanoparticles in sand columns under varying moisture conditions (0–30%), nanoparticle concentrations (0–10 mg/g), lithology (presence of clay), pore water salinity (0.0275 and 0.1000 S/m), and particle size (35, 90–210 and 1500–2500 nm). Based on the Cole-Cole relaxation models we obtained the chargeability and the time constant. We demonstrate that complex conductivity can detect silver nanoparticles in porous media with the response enhanced by higher concentrations of silver nanoparticles, moisture content, ionic strength, clay content and particle diameter. Quantification of the volumetric silver nanoparticles content in the porous media can also be obtained from complex co

  17. Biosynthesis of PVA encapsulated silver nanoparticles

    Directory of Open Access Journals (Sweden)

    Sharmila Chandran

    2016-10-01

    Full Text Available Green synthesis of metal nanoparticles is an important technique in the methods of eco-friendly nanoparticle production. The synthesis of silver nanoparticles was accomplished using Ocimum sanctum leaf extract at room temperature. These particles were then encapsulated with polyvinyl alcohol (PVA polymer matrix. The presence of silver was confirmed by different characterization techniques such as UV–vis spectroscopy, Fourier transform infrared spectroscopy (FTIR and X-Ray Diffraction (XRD. Scanning electron microscopic (SEM images of the synthesized powder shows spherical shaped silver nanoparticles embedded in sponge-like polymer matrix. The energy dispersive X-ray analysis confirms the presence of elemental silver along with iron signal. Energy dispersive signal corresponding to elemental iron has been attributed to O. sanctum plant. The silver nanoparticles in PVA matrix thus obtained shows high antibacterial activity against gram positive Staphylococcus aureus (S. aureus and gram negative Escherichia coli (E. coli water borne bacteria. The inhibition zone against S. aureus and E. coli were also calculated.

  18. Biocidal properties of maltose reduced silver nanoparticles against American foulbrood diseases pathogens.

    Science.gov (United States)

    Çulha, Mustafa; Kalay, Şaban; Sevim, Elif; Pinarbaş, Müberra; Baş, Yıldız; Akpinar, Rahşan; Karaoğlu, Şengül Alpay

    2017-12-01

    Bee disease caused by spore-forming Paenibacillus larvae and Paenibacillus alvei is a serious problem for honey production. Thus, there is an ongoing effort to find an effective agent that shows broad biocidal activity with minimal environmental hazard. In this study, the biocidal effect of maltose reduced silver nanoparticles (AgNPs) is evaluated against American foulbrood and European foulbrood pathogens. The results demonstrate that the maltose reduced AgNPs are excellent short and long-term biocides against P. larvae isolates. The long-term effect suggests that the Ag+ ions are released from the AgNPs with increasing time in a controlled manner.

  19. First evidence of European eels exiting the Mediterranean Sea during their spawning migration

    DEFF Research Database (Denmark)

    Amilhat, Elsa; Aarestrup, Kim; Faliex, Elisabeth

    2016-01-01

    female silver eels from the south of France with pop-up satellite tags during escapement from coastal waters. Once in deeper water, the eels quickly established diel vertical migration (DVM) between the upper and lower mesopelagic zone. Five tagged eels were taken by predators within the Mediterranean...

  20. Silver-functionalized carbon nanofiber composite electrodes for ibuprofen detection

    NARCIS (Netherlands)

    Manea, F.; Motoc, S.; Pop, A.; Remes, A.; Schoonman, J.

    2012-01-01

    The aim of this study is to prepare and characterize two types of silver-functionalized carbon nanofiber (CNF) composite electrodes, i.e., silver-decorated CNF-epoxy and silver-modified natural zeolite-CNF-epoxy composite electrodes suitable for ibuprofen detection in aqueous solution. Ag carbon

  1. Synthesis of nanosized silver colloids by microwave dielectric heating

    Indian Academy of Sciences (India)

    Silver nanosized crystallites have been synthesized in aqueous and polyols viz., ethylene glycol and glycerol, using a microwave technique. Dispersions of colloidal silver have been prepared by the reduction of silver nitrate both in the presence and absence of stabilizer poly(vinylpyrolidone) (PVP). It was observed that ...

  2. Fabrication and Antibacterial Performance of Nano-silver-Doped ...

    African Journals Online (AJOL)

    NICO

    enhancing the antibacterial activity of nanoparticles.15,16 In addi- tion, the antibacterial properties of nano-silver-doped filter paper against Escherichia coli have been studied.17 Silver ion release from sol-gel coatings has demonstrated antibacterial activ- ity against E. coli.18,19 Also, nano-silver-coated fabric inhibited the.

  3. Physicochemical properties of protein-modified silver nanoparticles in seawater

    Science.gov (United States)

    Zhong, Hangyue

    2013-10-01

    This study investigated the physicochemical properties of silver nanoparticles stabilized with casein protein in seawater. UV?vis spectrometry, dynamic light scattering (DLS), and transmission electron microscopy (TEM) were applied to measure the stability of silver nanoparticles in seawater samples. The obtained results show an increased aggregation tendency of silver nanoparticles in seawater, which could be attributed its relatively high cation concentration that could neutralize the negatively charges adsorbed on the surface of silver nanoparticles and reduce the electrostatic repulsion forces between nanoparticles. Similarly, due to the surface charge screening process, the zeta potential of silver nanoparticles in seawater decreased. This observation further supported the aggregation behavior of silver nanoparticles. This study also investigated the dissolution of silver nanoparticles in seawater. Result shows that the silver nanoparticle dissolution in DI water is lower than in seawater, which is attributed to the high Cl? concentration present in seawater. As Cl? can react with silver and form soluble AgCl complex, dissolution of silver nanoparticles was enhanced. Finally, this study demonstrated that silver nanoparticles are destabilized in seawater condition. These results may be helpful in understanding the environmental risk of discharged silver nanoparticles in seawater conditions.

  4. Synthesis of silver impregnated carbon nanotubes and cyclodextrin ...

    African Journals Online (AJOL)

    Silver impregnated carbon nanotubes and cyclodextrin polymers were synthesised by first functionalising carbon nanotubes in a mixture of nitric and sulphuric acid before impregnating them with silver nanoparticles. The silver impregnated functionalised carbon nanotubes were then polymerised with β cyclodextrin using ...

  5. Biosynthesis of silver nanoparticles by marine bacterium, Idiomarina ...

    Indian Academy of Sciences (India)

    In this paper, we report the intracellular synthesis of silver nanoparticles (SNPs) by the highly silver-tolerant marine bacterium, Idiomarina sp. PR58-8 on exposure to 5mM silver nitrate. SNPs were characterized by UV-visible spectrophotometry, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission ...

  6. A New Silver Complex with Ofloxacin – Preliminary Study

    Directory of Open Access Journals (Sweden)

    Rusu Aura

    2016-06-01

    Full Text Available Objective: Silver complexes of antibacterial quinolones have the potential advantage of combining the antibacterial activity of silver and fluoroquinolones. The objective of our study was the preparation and the preliminary physico-chemical characterization of a silver complex with ofloxacin.

  7. 25 CFR 304.3 - Classifying and marking of silver.

    Science.gov (United States)

    2010-04-01

    ... Indians INDIAN ARTS AND CRAFTS BOARD, DEPARTMENT OF THE INTERIOR NAVAJO, PUEBLO, AND HOPI SILVER, USE OF GOVERNMENT MARK § 304.3 Classifying and marking of silver. For the present the Indian Arts and Crafts Board... Government mark. All such marking of silver shall, for the present, be done by an agent of the Indian Arts...

  8. 25 CFR 304.7 - Eligibility of silver meeting standards.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Eligibility of silver meeting standards. 304.7 Section 304.7 Indians INDIAN ARTS AND CRAFTS BOARD, DEPARTMENT OF THE INTERIOR NAVAJO, PUEBLO, AND HOPI SILVER... currently made in compliance with the standards of the Indian Arts and Crafts Board, other silver products...

  9. Pulsed laser excitation of phosphate stabilised silver nanoparticles

    Indian Academy of Sciences (India)

    Laser flash photolysis studies were carried out on two types of silver nanoparticles prepared by -radiolysis of Ag+ solutions in the presence of polyphosphate as the stabiliser. Type I silver nanoparticles displayed a surface plasmon band at 390 nm. Type II silver nanoparticles showed a 390 nm surface plasmon band with a ...

  10. Antimicrobial Activity of Silver Nanoparticles Synthesized by Marine ...

    African Journals Online (AJOL)

    In this work, in vitro biosynthesis of silver nanoparticles was achieved using AgNO3 as a substrate by L. plantrum isolated from mangrove rhizosphere region in South East Coast of India (Gulf of Mannar). The biosynthesis was faster within a minute of silver ion coming in contact with the cell filtrate. Presence of silver ...

  11. Synthesis of silver nanoparticles by sophorolipids: Effect of ...

    Indian Academy of Sciences (India)

    We report in situ synthesis of silver nanoparticles using biosurfactants called sophorolipids as reducing and capping agents. We further study the effect of temperature and the structure of sophorolipid on the size of silver nanoparticles obtained. The silver nanoparticles were characterized by UVvisible, transmission electron ...

  12. In vitro assessment of activity of graphene silver composite sheets ...

    African Journals Online (AJOL)

    Purpose: To synthesize graphene-based silver nanocomposites and evaluate their antimicrobial and anti-Tomato Bushy Stunt Virus (TBSV) activities. Methods: A graphene-based silver composite was prepared by adsorbing silver nanoparticles AgNPs to the surfaces of graphene oxide (GO) sheets. Scanning electron ...

  13. The Antifungal Activity and Cytotoxicity of Silver Containing Denture ...

    African Journals Online (AJOL)

    2015-10-30

    Oct 30, 2015 ... time- or silver-dependent cytotoxicity of PMMA denture base material containing ... dental materials.[14] Silver ions are biologically active,[15,16] so silver may have adverse effects on human cells.[17]. Although the literature reports various ..... vitro Candida colonization on acrylic resins and denture liners:.

  14. Mechanism of silver nanoparticle toxicity is dependent on dissolved silver and surface coating in Caenorhabditis elegans.

    Science.gov (United States)

    Yang, Xinyu; Gondikas, Andreas P; Marinakos, Stella M; Auffan, Melanie; Liu, Jie; Hsu-Kim, Heileen; Meyer, Joel N

    2012-01-17

    The rapidly increasing use of silver nanoparticles (Ag NPs) in consumer products and medical applications has raised ecological and human health concerns. A key question for addressing these concerns is whether Ag NP toxicity is mechanistically unique to nanoparticulate silver, or if it is a result of the release of silver ions. Furthermore, since Ag NPs are produced in a large variety of monomer sizes and coatings, and since their physicochemical behavior depends on the media composition, it is important to understand how these variables modulate toxicity. We found that a lower ionic strength medium resulted in greater toxicity (measured as growth inhibition) of all tested Ag NPs to Caenorhabditis elegans and that both dissolved silver and coating influenced Ag NP toxicity. We found a linear correlation between Ag NP toxicity and dissolved silver, but no correlation between size and toxicity. We used three independent and complementary approaches to investigate the mechanisms of toxicity of differentially coated and sized Ag NPs: pharmacological (rescue with trolox and N-acetylcysteine), genetic (analysis of metal-sensitive and oxidative stress-sensitive mutants), and physicochemical (including analysis of dissolution of Ag NPs). Oxidative dissolution was limited in our experimental conditions (maximally 15% in 24 h) yet was key to the toxicity of most Ag NPs, highlighting a critical role for dissolved silver complexed with thiols in the toxicity of all tested Ag NPs. Some Ag NPs (typically less soluble due to size or coating) also acted via oxidative stress, an effect specific to nanoparticulate silver. However, in no case studied here was the toxicity of a Ag NP greater than would be predicted by complete dissolution of the same mass of silver as silver ions.

  15. Europeanization and transnational states

    DEFF Research Database (Denmark)

    Jacobsson, Bengt; Lægreid, Per; Pedersen, Ove K.

    This work investigates what happens to an organized political unit when it becomes part of a larger entity and, in particular, how increased European integration and the tentative moves towards a transnational state will affect the European Union's nation state. Europeanization and the transforma......This work investigates what happens to an organized political unit when it becomes part of a larger entity and, in particular, how increased European integration and the tentative moves towards a transnational state will affect the European Union's nation state. Europeanization...... in central government agencies. It concludes that the consequences of Europeanization can be described as the growth of a transnational administration where identities as well as loyalties are created in processes that transcend the borders of states....

  16. Morphological and molecular characteristics of foliar nematode attacking silver birch (Betula pendula Roth in Poland

    Directory of Open Access Journals (Sweden)

    Chałańska A.

    2017-09-01

    Full Text Available Aphelenchoides fragariae (Ritzema Bos, 1890 Christie, 1932 was isolated from leaves of silver birch (Betula pendula Roth seedlings proving that the source of infection was anemones plants. This is the first report to our best knowledge showing that the source of nematode infection of a woody plant could be a perennial plant. A. fragariae was identified by morphometric and molecular analyses. Morphological diagnosis based on the bending shape of the tail of males and pronounced apex and rostrum proved to be the most accurate reliable characteristic. On the opposite, the high variability of the mucron shape in female tails made the identification by microscopic analyses difficult. Identification of the species was confirmed by analysis of 28S rDNA sequences. The morphometric data of adults extracted from silver birch was compared with that of nematodes isolated from Anemone hupehensis (Lemoine Lemoine. Males body length varied highly in samples collected from both host plant species.

  17. Comparison of silver nylon wound dressing and silver sulfadiazine in partial burn wound therapy.

    Science.gov (United States)

    Abedini, Fereydoon; Ahmadi, Abdollah; Yavari, Akram; Hosseini, Vahid; Mousavi, Sarah

    2013-10-01

    The study aims to perform a comparative assessment of two types of burn wound treatment. To do the assessment, patients with partial thickness burn wounds with total body surface area nylon wound dressing or silver sulfadiazine cream. Efficacy of treatment, use of analgesics, number of wound dressing change, wound infection and final hospitalisation cost were evaluated. The study showed silver nylon wound dressing significantly reduced length of hospital stay, analgesic use, wound infection and inflammation compared with silver sulfadiazine. © 2012 The Authors. International Wound Journal © 2012 John Wiley & Sons Ltd and Medicalhelplines.com Inc.

  18. In-Situ Silver Acetylide Silver Nitrate Explosive Deposition Measurements Using X-Ray Fluorescence.

    Energy Technology Data Exchange (ETDEWEB)

    Covert, Timothy Todd

    2014-09-01

    The Light Initiated High Explosive facility utilized a spray deposited coating of silver acetylide - silver nitrate explosive to impart a mechanical shock into targets of interest. A diagnostic was required to measure the explosive deposition in - situ. An X - ray fluorescence spectrometer was deployed at the facility. A measurement methodology was developed to measure the explosive quantity with sufficient accuracy. Through the use of a tin reference material under the silver based explosive, a field calibration relationship has been developed with a standard deviation of 3.2 % . The effect of the inserted tin material into the experiment configuration has been explored.

  19. Silver nanoparticle containing silk fibroin bionanotextiles

    Energy Technology Data Exchange (ETDEWEB)

    Calamak, Semih; Aksoy, Eda Ayse [Hacettepe University, Department of Basic Pharmaceutical Sciences, Faculty of Pharmacy (Turkey); Erdogdu, Ceren; Sagıroglu, Meral [Hacettepe University, Department of Pharmaceutical Microbiology, Faculty of Pharmacy (Turkey); Ulubayram, Kezban, E-mail: ukezban@hacettepe.edu.tr [Hacettepe University, Department of Basic Pharmaceutical Sciences, Faculty of Pharmacy (Turkey)

    2015-02-15

    Development of new generation bionanotextiles is an important growing field, and they have found applications as wound dressings, bandages, tissue scaffolds, etc. In this study, silver nanoparticle (AgNP) containing silk-based bionanotextiles were fabricated by electrospinning, and processing parameters were optimized and discussed in detail. AgNPs were in situ synthesized within fibroin nanofibers by UV reduction of silver ions to metallic silver. The influence of post-treatments via methanol treatment and glutaraldehyde (GA) vapor exhibited changes in the secondary structure of silk. Methanol treatment increased the tensile properties of fibers due to supported crystalline silk structure, while GA vapor promoted amorphous secondary structure. AgNP containing silk fibroin bionanotextiles had strong antibacterial activity against gram-positive Staphylococcus aureus and gram-negative Pseudomonas aeruginosa.

  20. Silver containing sorbents: Physicochemical and biological properties

    Directory of Open Access Journals (Sweden)

    L.N. Rachkovskaya

    2016-06-01

    Full Text Available New silver containing sorbents, based on mineral carriers, such as alumina and silica systems with a meso- and macro- porous structure, have a higher mechanical resistance and, hydrophilic and hydrophobic chemical composition of the surface. These sorbents are easy to find and relatively inexpensive, compared to their known equivalents. They are furthermore characterised by high specific surface and simple preparation, whilst the addition of silver considerably increases their antiseptic activity. The results of research of the physical, chemical and biological properties of the developed substances, as well as bio-comparability of sorbents with biological tissues, are presented in this paper. The modified material acts simultaneously as the carrier for active substances to the area of therapeutic application and as a sorbent used to remove toxic agents from such areas. This approach led us to modify the sorbent, and prolong the delivery of substances such as silver, as an effective antibacterial and antimycotic agent.

  1. Modifications to the silver physical developer.

    Science.gov (United States)

    Burow, David; Seifert, Donald; Cantu, Antonio A

    2003-09-01

    The silver physical developer is currently the most successful reagent used for visualizing the water-insoluble components (e.g., lipids) of latent prints on porous surfaces. It is normally used after the amino acid visualizing reagents (e.g., ninhydrin and DFO) are used. This work found that the performance of the current formulation of silver physical developer is strongly reduced when the water used is changed from the usual distilled water to the more purified reverse osmosis/deionized (RO/DI) water. Based on numerous experiments involving the systematic variation of the component concentrations, the performance was restored and even improved by reducing the concentration of all the components (except that of the ferric salt) and by including malic acid in the formulation. These modifications resulted in a new silver physical developer formulation that performs as well as or better than the current formulation and is less expensive to make.

  2. Percutaneous penetration of silver from a silver containing garment in healthy volunteers and patients with atopic dermatitis

    NARCIS (Netherlands)

    Pluut, Olivier A.; Bianco, Carlotta; Jakasa, Ivone; Visser, Maaike J.; Krystek, Petra; Larese-Filon, Francesca; Rustemeyer, Thomas; Kezic, Sanja

    2015-01-01

    Human data on dermal absorption of silver under "in use" scenario are scarce which hampers health risk assessment. The main objective of the present study was to determine percutaneous penetration of silver after dermal exposure to silver containing garment in healthy individuals and atopic

  3. Silver Nanoparticles in the Lung: Toxic Effects and Focal Accumulation of Silver in Remote Organs

    Directory of Open Access Journals (Sweden)

    Martin Wiemann

    2017-12-01

    Full Text Available The distribution of silver (Ag into remote organs secondary to the application of Ag nanoparticles (Ag-NP to the lung is still incompletely understood and was investigated in the rat with imaging methods. Dose-finding experiments were carried out with 50 nm- or 200 nm-sized polyvinyl pyrrolidine (PVP-coated Ag-NP using alveolar macrophages in vitro and female rats, which received Ag-NP via intratracheal instillation. In the main study, we administered 37.5–300 µg per rat lung of the more toxic Ag50-PVP and assessed the broncho-alveolar lavage fluid (BALF for inflammatory cells, total protein and fibronectin after three and 21 days. In parallel, lung tissue was analysed for DNA double-strand breaks and altered cell proliferation. While 75–150 µg Ag50-PVP per rat lung caused a reversible inflammation, 300 µg led to DNA damage, accelerated cell proliferation and progressively increasing numbers of neutrophilic granulocytes. Ag accumulation was significant in homogenates of liver and other peripheral organs upon lung dose of ≥75 µg. Quantitative laser-ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS combined with enhanced dark field microscopy and autometallography revealed focal accumulations of Ag and/or Ag-NP in sections of peripheral organs: mediastinal lymph nodes contained Ag-NP especially in peripheral macrophages and Ag in argyrophilic fibres. In the kidney, Ag had accumulated within proximal tubuli, while renal filter structures contained no Ag. Discrete localizations were also observed in immune cells of liver and spleen. Overall, the study shows that concentrations of Ag-NP, which elicit a transient inflammation in the rat lung, lead to focal accumulations of Ag in peripheral organs, and this might pose a risk to particular cell populations in remote sites.

  4. Recovery of silver from CEPOD anolyte solutions

    Energy Technology Data Exchange (ETDEWEB)

    Blanchard, D.L.; Surma, J.E.; Alexander, D.L.; Shade, E.H.; Matheson, J.D.; Cochran, D.L.; Wheelwright, E.J. [Pacific Northwest Lab., Richland, WA (United States); Boyd, T. [EG& G Rocky Flats Plant, Golden, CO (United States)

    1994-09-01

    The process known as Catalyzed Electrochemical Plutonium Oxide Dissolution (CEPOD) has been shown effective for removing plutonium from a variety of residues and solids. This process involves the electrochemical oxidation of PuO{sub 2} (and other Pu species) to (PuO{sub 2}){sup 2+}, and dissolution of the latter species in the anode solution (anolyte). Silver is used to transfer charge from the electrodes to the solid Pu oxide. Ag (1) is oxidized at the anode to Ag(II) and carried by the solution to the plutonium oxide solids, where the silver and oxide undergo a redox reaction that converts Pu(IV) to Pu(VI), and Ag(II) to Ag(I). Other metal ions [such as Ce(IV) and Co(III)] may also be used for this charge transfer, but have been found to be less effective than silver. The same process may be used to destroy various organic materials (such as paper and wood, oil and fuels, and synthetic polymer materials) by complete oxidation to CO{sub 2} or H{sub 2}O, for example. Upon completion of a CEPOD dissolver run, the anolyte may be processed to remove solution species of interest (i.e., Pu), or the anolyte may be recycled, or disposed. Because silver is a Resource Conservation and Recovery Act (RCRA) land ban material, it must be removed from waste streams. Preliminary experiments, completed in FY 1991, demonstrated a simple, effective technique for silver removal from solutions. Ascorbic acid (C{sub 6}H{sub 8}O{sub 6}) Was Used to reduce silver ion to metallic silver, which precipitates from solution. The process was demonstrated effective on a bench scale using samples of actual CEPOD anolyte. Further experiments, in FY 1993, optimized these parameters and demonstrated the effectiveness of the technique on CEPOD anolyte on a larger, process scale (liters of solution). This report describes both the preliminary bench-scale experiments and the more recent process-scale experiments. The results are also compared to electro-deposition, another method of silver ion removal.

  5. Fluorescent DNA Stabilized Silver Nanoclusters as Biosensors

    Directory of Open Access Journals (Sweden)

    Alfonso Latorre

    2013-01-01

    Full Text Available DNA stabilized fluorescent silver nanoclusters are promising materials, of which fluorescent properties can be exploited to develop sensors. Particularly, the presence of a DNA strand in the structure has promoted the development of gene sensors where one part of the sensor is able to recognize the target gene sequence. Moreover, since oligonucleotides can be designed to have binding properties (aptamers a variety of sensors for proteins and cells have been developed using silver nanoclusters. In this review the applications of this material as sensors of different biomolecules are summarized.

  6. Mineral resource of the month: silver

    Science.gov (United States)

    Katrivanos, Florence C.

    2015-01-01

    Silver, one of the eight precious or noble metals, has been used extensively throughout recorded history for various medical purposes, ornaments and utensils, and for its intrinsic value as the basis for trade and monetary systems. Silver has played a significant role in world history, financing a Greek victory over the Persians in 480 B.C., helping Spain become a world power in the 16th and 17th centuries, and helping fund the Union forces during the U.S. Civil War, to give a few examples.

  7. Autometallography: tissue metals demonstrated by a silver enhancement kit

    DEFF Research Database (Denmark)

    Danscher, G; Nørgaard, J O; Baatrup, E

    1987-01-01

    In biological tissue, minute accumulations of gold, silver, mercury and zinc can be visualized by a technique whereby metallic silver is precipitated on tiny accumulations of the two noble metals, or on selenites or sulphides of all four metals. In the present study a silver enhancement kit, prim...... methods and for demonstration of gold, silver, and mercury in tissues from animals intravitally exposed to these metals. It can also be used for counterstaining silver treated osmium fixed tissues embedded in plastic. Udgivelsesdato: 1987-null...

  8. Management of silver fir (Abies alba Mill.) in Slovenia

    OpenAIRE

    Bončina, Andrej; Ficko, Andrej; Klopčič, Matija; Matijašič, Dragan; Poljanec, Aleš

    2009-01-01

    In the paper, we analysed the structure and developmental characteristics of forest stands with silver fir in Slovenia, the management and cut in four forest site strata, where silver fir occurs. We used databases from the Slovenia Forest Service. In growing stock (GS) of silver fir, large (dbh=30-49cm) and very large (d=50 cm and more) diameter trees account for 84.9 % at the national level. The highest share of very large diameter silver fir trees (45 %) is in Dinaric silver fir forests and...

  9. Silver surface enrichment of silver-copper alloys: a limitation for the analysis of ancient silver coins by surface techniques

    Science.gov (United States)

    Beck, L.; Bosonnet, S.; Réveillon, S.; Eliot, D.; Pilon, F.

    2004-11-01

    The surface enrichment of archaeological silver-copper alloys has been recognized for many years. However, the origin of this enrichment is not well defined and many hypotheses have been put forward to account for this behaviour: segregation of the components during casting, deliberate thermal and/or chemical post-treatment, abrasion or corrosion. Among the hypotheses mentioned above, we have focused our study on the first step of coin manufacturing. Replications of silver-copper standards of various compositions ranging from 30% to 80% Ag, reflecting the composition of silver blanks, have been produced. Metallographic examination, PIXE and SEM-EDS have been used for the characterization of each sample. A model of the direct enrichment has been established. This model allows us to propose a relationship between the surface composition and the silver content of the core. Comparison with data of Roman coins from the Roman site of Châteaubleau (France) and from the literature and consequences for the analyses of ancient coins by surface methods are presented.

  10. Bioaccumulation of silver in Daphnia magna:Waterborne and dietary exposure to nanoparticles and dissolved silver

    NARCIS (Netherlands)

    Ribeiro, Fabianne; van Gestel, C.A.M.; Pavlaki, M.D.; Azevedo, S.; Soares, A.M.V.M.; Loureiro, S.

    2017-01-01

    Silver nanoparticles (Ag-NP) are incorporated into commercial products as antimicrobial agents, which potentiate their emission to the environment. The toxicity of Ag-NP has been associated with the release of Ag ions (Ag

  11. Synthesis and characterization of silver nanoparticles in AOT microemulsion system

    Science.gov (United States)

    Zhang, Wanzhong; Qiao, Xueliang; Chen, Jianguo

    2006-11-01

    Colloidal silver nanoparticles have been synthesized in water-in-oil microemulsion using silver nitrate solubilized in the water core of one microemulsion as source of silver ions, hydrazine hydrate solubilized in the water core of another microemulsion as reducing agent, dodecane as the oil phase, sodium bis(2-ethylhexyl) sulfosuccinate (AOT) as the surfactant. The UV-vis absorption spectra and transmission electron microscopy (TEM) have been used to trace the growth process and elucidate the structure of the silver nanoparticles. UV-vis spectra show that the Ag4+ intermediates formed at early stages of the reaction and then the clusters grow or aggregate to larger nanoparticles. TEM micrographs confirm that the silver nanoparticles are all spherical. The resulting particles have a very narrow size distribution. Meanwhile, the diameter size of the particles is so small that the smallest mean diameter is only 1.6 nm. IR results show that the surfactant molecules are strongly adsorbed on the surface of silver particles through a coordination bond between the silver atom and the sulfonic group of AOT molecules, which endows the particles with a good stability in oil solvents. As dodecane is used as oil solvent to prepare silver nanoparticles, the formed nano-silver sol is almost nontoxic. As a result, the silver nanoparticles need not be separated from the reaction solution and the silver sol may be directly used in antibacterial fields.

  12. Latent synthesis of electrically conductive surface-silvered polyimide films.

    Science.gov (United States)

    Davis, Luke M; Abelt, Christopher J; Scott, Joseph L; Orlova, Evguenia; Thompson, David W

    2009-01-01

    A facile ambient temperature route to the fabrication of surface silver-metallized polyimide films is described. Silver(I) trifluoromethanesulfonate or silver(I) nitrate and a polyimide, derived from 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride and an equimolar amount of 4,4'-oxydianiline and 3,5-diaminobenzoic acid, were dissolved together in dimethylacetamide. Silver(I)-doped films were prepared at thicknesses of 25-40 microm and depleted of solvent by evaporation at ambient temperature and low humidity. The silver(I)-ion-containing films were then treated with aqueous solutions of the reducing agents hydrazine hydrate and hydroxylamine, which brought forth surface-silvered films exhibiting conductivity on the order of bulk polycrystalline silver accompanied by modest-to-high specular reflectivity.

  13. Phytochemical Synthesis and Preliminary Characterization of Silver Nanoparticles Using Hesperidin

    Directory of Open Access Journals (Sweden)

    Anish Stephen

    2013-01-01

    Full Text Available This paper is the first of its kind for development of rapid and ecofriendly method for synthesis of silver nanoparticles from aqueous solution of silver nitrate using the flavonoid “hesperidin” and optimization of the methodology. There is formation of stable spherical silver nanoparticles in the size range of 20–40 nm. Optimization of methodology in terms of concentration of reactants and pH of the reaction mixture reduced the reaction time for silver nanoparticle formation to 2 mins. Silver nanoparticles (AgNPs were characterized by UV-Vis spectroscopy and transmission electron microscopy (TEM. UV-vis spectroscopy derived spectrum demonstrated a peak of 430 nm which corresponds to the plasmon absorbance of silver nanoparticles. Transmission electron microscopy revealed spherical shaped silver nanoparticles in the size range of 20–40 nm.

  14. Silver nanosystems for photoacoustic imaging and image-guided therapy

    Science.gov (United States)

    Homan, Kimberly; Shah, Jignesh; Gomez, Sobeyda; Gensler, Heidi; Karpiouk, Andrei; Brannon-Peppas, Lisa; Emelianov, Stanislav

    2010-01-01

    Due to their optical absorption properties, metallic nanoparticles are excellent photoacoustic imaging contrast agents. A silver nanosystem is presented here as a potential contrast agent for photoacoustic imaging and image-guided therapy. Currently, the nanosystem consists of a porous silver layer deposited on the surface of spherical silica cores ranging in diameter from 180 to 520 nm. The porous nature of the silver layer will allow for release of drugs or other therapeutic agents encapsulated in the core in future applications. In their current PEGylated form, the silver nanosystem is shown to be nontoxic in vitro at concentrations of silver up to 2 mg∕ml. Furthermore, the near-infrared absorbance properties of the nanosystem are demonstrated by measuring strong, concentration-dependent photoacoustic signal from the silver nanosystem embedded in an ex vivo tissue sample. Our study suggests that silver nanosystems can be used as multifunctional agents capable of augmenting image-guided therapy techniques. PMID:20459238

  15. Selective separation of silver(I) by novel substituted thiourea

    Energy Technology Data Exchange (ETDEWEB)

    Khan, A. [Pakistan Inst. of Nuclear Science and Technology (PINSTECH), Islamabad (Pakistan). Chemistry Div.

    2007-07-01

    The extraction of silver(I) from nitric acid solutions using naphthyl substituted thiourea such as 1-naphthylthiourea (ANTU) has been studied. Different variables: equilibration time, aqueous pH, chloride and extractant concentrations and organic phase diluent that could affect the extraction system were evaluated at 28.0 {+-} 2.0 C. It was found that silver is quantitatively extracted by ANTU over the entire studied range of nitric acid concentration. Extraction of silver by ANTU is fast and equilibration was achieved in less than five minutes. Experimental data relating to silver have been analysed to determine the stoichiometry of the extracted species. Effect of foreign ions on the extraction of silver was carried out. Recycling capacity of the extractant was also studied. Thiourea and EDTA solutions were found suitable for > 99% stripping of extracted silver(I). The reagent has been found to have high selectivity for silver against copper, cadmium, nickel, cobalt, hafnium, zirconium and europium. (orig.)

  16. Evidence for a receiver bias underlying female preference for a male mating pheromone in sea lamprey

    Science.gov (United States)

    Buchinger, Tyler J.; Wang, Huiyong; Li, Weiming; Johnson, Nicholas S.

    2013-01-01

    Receiver bias models suggest that a male sexual signal became exaggerated to match a pre-existing sensory, perceptual or cognitive disposition of the female. Accordingly, these models predict that females of related taxa possessing the ancestral state of signalling evolved preference for the male trait in a non-sexual context. We postulated that female preference for the male-released bile alcohol mating pheromone, 3 keto petromyzonol sulfate (3kPZS), of the sea lamprey (Petromyzon marinus) evolved as a result of a receiver bias. In particular, we propose that migratory silver lamprey (Ichthyomyzon unicuspis), a basal member of the Petromyzontidae, evolved a preference for 3kPZS released by stream-resident larvae as a means of identifying productive habitat for offspring. Larval silver lamprey released 3kPZS at rates sufficient to be detected by migratory lampreys. Females responded to 3kPZS by exhibiting upstream movement behaviours relevant in a migratory context, but did not exhibit proximate behaviours important to mate search and spawning. Male silver lamprey did not release 3kPZS at rates sufficient to be detected by females in natural high-volume stream environments. We infer that female silver lamprey cue onto 3kPZS excreted by stream-resident larvae as a mechanism to locate habitat conducive to offspring survival and that males do not signal with 3kPZS. We suggest that this female preference for a male signal in a non-sexual context represents a bias leading to the sexual signalling observed in sea lamprey.

  17. Yeast-derived biosynthesis of silver/silver chloride nanoparticles and their antiproliferative activity against bacteria

    OpenAIRE

    Eugenio, Mateus; Müller, Nathalia; Frasés, Susana; Almeida-Paes, Rodrigo; Lima, Luís Maurício T.R.; Lemgruber, Leandro; Farina, Marcos; de Souza, Wanderley; Sant'Anna, Celso

    2016-01-01

    Here, we provide the first evidence of yeast strains assisted Ag/AgCl-NPs production in vitro. The formed nanoparticles were characterized by spectroscopic and electron microscopy approaches. UV-vis supported the biosynthesis. TEM analysis evidenced that the nanoparticles mainly presented a circular shape and their diameters varied mostly being in the range 2 to 10 nm. XRD analysis showed a crystalline structure, with diffraction peaks corresponding to metallic silver and silver chloride nano...

  18. A physiologically based pharmacokinetic model for ionic silver and silver nanoparticles

    Science.gov (United States)

    Bachler, Gerald; von Goetz, Natalie; Hungerbühler, Konrad

    2013-01-01

    Silver is a strong antibiotic that is increasingly incorporated into consumer products as a bulk, salt, or nanosilver, thus potentially causing side-effects related to human exposure. However, the fate and behavior of (nano)silver in the human body is presently not well understood. In order to aggregate the existing experimental information, a physiologically based pharmacokinetic model (PBPK) was developed in this study for ionic silver and nanosilver. The structure of the model was established on the basis of toxicokinetic data from intravenous studies. The number of calibrated parameters was minimized in order to enhance the predictive capability of the model. We validated the model structure for both silver forms by reproducing exposure conditions (dermal, oral, and inhalation) of in vivo experiments and comparing simulated and experimentally assessed organ concentrations. Therefore, the percutaneous, intestinal, or pulmonary absorption fraction was estimated based on the blood silver concentration of the respective experimental data set. In all of the cases examined, the model could successfully predict the biodistribution of ionic silver and 15–150 nm silver nanoparticles, which were not coated with substances designed to prolong the circulatory time (eg, polyethylene glycol). Furthermore, the results of our model indicate that: (1) within the application domain of our model, the particle size and coating had a minor influence on the biodistribution; (2) in vivo, it is more likely that silver nanoparticles are directly stored as insoluble salt particles than dissolve into Ag+; and (3) compartments of the mononuclear phagocytic system play a minor role in exposure levels that are relevant for human consumers. We also give an example of how the model can be used in exposure and risk assessments based on five different exposure scenarios, namely dietary intake, use of three separate consumer products, and occupational exposure. PMID:24039420

  19. Antimicrobial activity of biogenic silver nanoparticles, and silver chloride nanoparticles: an overview and comments.

    Science.gov (United States)

    Durán, Nelson; Nakazato, Gerson; Seabra, Amedea B

    2016-08-01

    The antimicrobial impact of biogenic-synthesized silver-based nanoparticles has been the focus of increasing interest. As the antimicrobial activity of nanoparticles is highly dependent on their size and surface, the complete and adequate characterization of the nanoparticle is important. This review discusses the characterization and antimicrobial activity of biogenic synthesized silver nanoparticles and silver chloride nanoparticles. By revising the literature, there is confusion in the characterization of these two silver-based nanoparticles, which consequently affects the conclusion regarding to their antimicrobial activities. This review critically analyzes recent publications on the synthesis of biogenic silver nanoparticles and silver chloride nanoparticles by attempting to correlate the characterization of the nanoparticles with their antimicrobial activity. It was difficult to correlate the size of biogenic nanoparticles with their antimicrobial activity, since different techniques are employed for the characterization. Biogenic synthesized silver-based nanoparticles are not completely characterized, particularly the nature of capped proteins covering the nanomaterials. Moreover, the antimicrobial activity of theses nanoparticles is assayed by using different protocols and strains, which difficult the comparison among the published papers. It is important to select some bacteria as standards, by following international foundations (Pharmaceutical Microbiology Manual) and use the minimal inhibitory concentration by broth microdilution assays from Clinical and Laboratory Standards Institute, which is the most common assay used in antibiotic ones. Therefore, we conclude that to have relevant results on antimicrobial effects of biogenic silver-based nanoparticles, it is necessary to have a complete and adequate characterization of these nanostructures, followed by standard methodology in microbiology protocols.

  20. Green synthesis of colloid silver nanoparticles and resulting biodegradable starch/silver nanocomposites.

    Science.gov (United States)

    Cheviron, Perrine; Gouanvé, Fabrice; Espuche, Eliane

    2014-08-08

    Environmentally friendly silver nanocomposite films were prepared by an ex situ method consisting firstly in the preparation of colloidal silver dispersions and secondly in the dispersion of the as-prepared nanoparticles in a potato starch/glycerol matrix, keeping a green chemistry process all along the synthesis steps. In the first step concerned with the preparation of the colloidal silver dispersions, water, glucose and soluble starch were used as solvent, reducing agent and stabilizing agent, respectively. The influences of the glucose amount and reaction time were investigated on the size and size distribution of the silver nanoparticles. Two distinct silver nanoparticle populations in size (diameter around 5 nm size for the first one and from 20 to 50 nm for the second one) were distinguished and still highlighted in the potato starch/glycerol based nanocomposite films. It was remarkable that lower nanoparticle mean sizes were evidenced by both TEM and UV-vis analyses in the nanocomposites in comparison to the respective colloidal silver dispersions. A dispersion mechanism based on the potential interactions developed between the nanoparticles and the polymer matrix and on the polymer chain lengths was proposed to explain this morphology. These nanocomposite film series can be viewed as a promising candidate for many applications in antimicrobial packaging, biomedicines and sensors. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Silver nanoparticles decorated lipase-sensitive polyurethane micelles for on-demand release of silver nanoparticles.

    Science.gov (United States)

    Su, Yuling; Zhao, Lili; Meng, Fancui; Wang, Quanxin; Yao, Yongchao; Luo, Jianbin

    2017-04-01

    In order to improve the antibacterial activities while decrease the cytotoxity of silver nanoparticles, we prepared a novel nanocomposites composed of silver nanoparticles decorated lipase-sensitive polyurethane micelles (PUM-Ag) with MPEG brush on the surface. The nanocomposite was characterized by UV-vis, TEM and DLS. UV-vis and TEM demonstrated the formation of silver nanoparticles on PU micelles and the nanoassembly remained intact without the presence of lipase. The silver nanoparticles were protected by the polymer matrix and PEG brush which show good cytocompatibility to HUVEC cells and low hemolysis. Moreover, at the presence of lipase, the polymer matrix of nanocomposites is subject to degradation and the small silver nanoparticles were released as is shown by DLS and TEM. The MIC and MBC studies showed an enhanced toxicity of the nanocomposites to both gram negative and gram positive bacteria, i.e. E. coli and S. aureus, as the result of the degradation of polymer matrix by bacterial lipase. Therefore, the nanocomposites are biocompatible to mammalian cells cells which can also lead to activated smaller silver nanoparticles release at the presence of bacteria and subsequently enhanced inhibition of bacteria growth. The satisfactory selectivity for bacteria compared to HUVEC and RBCs make PUM-Ag a promising antibacterial nanomedicine in biomedical field. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Biosynthesis and structural characterization of silver nanoparticles from bacterial isolates

    Energy Technology Data Exchange (ETDEWEB)

    Zaki, Sahar, E-mail: saharzaki@yahoo.com [Environmental Biotechnology Department, Genetic Engineering and Biotechnology Research Institute, Mubarak City for Scientific Research and Technology Applications, Alexandria, 21934 New Burgelarab City (Egypt); El Kady, M.F. [Fabrication Technology Department, Advanced Technology and New Materials Research Institute (ATNMRI), Mubarak City for Scientific Research and Technology Applications, Alexandria (Egypt); Abd-El-Haleem, Desouky [Environmental Biotechnology Department, Genetic Engineering and Biotechnology Research Institute, Mubarak City for Scientific Research and Technology Applications, Alexandria, 21934 New Burgelarab City (Egypt)

    2011-10-15

    Graphical abstract: In this study five bacterial isolates belong to different genera were found to be able to biosynthesize silver nanoparticles. Biosynthesis and spectral characterization are reported here. Highlights: {yields} About 300 bacterial isolates were screened for their ability to produce nanosilvers {yields} Five of them were potential candidates for synthesis of silver nanoparticles {yields} Production of silver nanoparticles was examined using UV-Vis, XRD, SEM and EDS. {yields} The presence of nanoparticles with all five bacterial isolates was confirmed. -- Abstract: This study aimed to develop a green process for biosynthesis of silver nanomaterials by some Egyptian bacterial isolates. This target was achieved by screening an in-house culture collection consists of 300 bacterial isolates for silver nanoparticle formation. Through screening process, it was observed that strains belonging to Escherichia coli (S30, S78), Bacillus megaterium (S52), Acinetobacter sp. (S7) and Stenotrophomonas maltophilia (S54) were potential candidates for synthesis of silver nanoparticles. The extracellular production of silver nanoparticles by positive isolates was investigated by UV-Vis spectroscopy, X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results demonstrated that UV-visible spectrum of the aqueous medium containing silver ion showed a peak at 420 nm corresponding to the plasmon absorbance of silver nanoparticles. Scanning electron microscopy micrograph showed formation of silver nanoparticles in the range of 15-50 nm. XRD-spectrum of the silver nanoparticles exhibited 2{theta} values corresponding to the silver nanocrystal that produce in hexagonal and cubic crystal configurations with different plane of orientation. In addition, the signals of the silver atoms were observed by EDS-spectrum analysis that confirms the presence of silver nanoparticles (Ag

  3. Female Sexual Dysfunction

    Science.gov (United States)

    ... medically as female sexual dysfunction. Many women experience problems with sexual function at some point. Female sexual dysfunction can occur at any stage of life. It can be lifelong or be acquired later in life. It can ...

  4. Female reproductive disorders

    DEFF Research Database (Denmark)

    Crain, D Andrew; Janssen, Sarah J; Edwards, Thea M

    2008-01-01

    To evaluate the possible role of endocrine-disrupting compounds (EDCs) on female reproductive disorders emphasizing developmental plasticity and the complexity of endocrine-dependent ontogeny of reproductive organs. Declining conception rates and the high incidence of female reproductive...

  5. Fertility Treatments for Females

    Science.gov (United States)

    ... for Females Share Facebook Twitter Pinterest Email Print Fertility Treatments for Females Once a woman is diagnosed ... The presence or absence of male factor infertility Fertility treatments are most likely to benefit women whose ...

  6. Colloidal silver solutions with antimicrobial properties

    Energy Technology Data Exchange (ETDEWEB)

    Petica, A. [INCDIE ICPE-Advanced Research, Bucharest (Romania)], E-mail: petica@icpe-ca.ro; Gavriliu, S.; Lungu, M.; Buruntea, N. [INCDIE ICPE-Advanced Research, Bucharest (Romania); Panzaru, C. [Institute of Medicine and Pharmacy, Iassy (Romania)

    2008-08-25

    Some colloidal silver solutions involving the electrochemical technique with 'sacrificial anode method and different stabilizers and co-stabilizers' have been prepared. A constant current pulse generator with stirrer at different working times has been used. To achieve stable colloidal silver solutions, a mix of different tensioactive agents namely [poly (N-vinylpyrrolidone)], Na-naphthalene sulphonate, Na-lauryl sulfate and Na-dodecyl sulphonate were tested. The effects of these various mixes of polymer and ionic surfactants upon the Ag concentration and UV-vis spectra of silver nanoparticles were determined by spectrophotometer techniques. The nanoparticles sizes have been analyzed through dynamic light scattering technique and the silver nanoparticle morphology has been evidenced by transmission electron microscopy (TEM). Micobiological analysis has been made by determining minimal inhibitorial concentration upon the following germs: Staphylococcus aureus (ATCC) (Gram-positive cocci), Pseudomonas aeruginosa (ATTC), Escherichia coli (ATCC) and Acinetobacter spp. (Gram-negative coccobacillus). To evaluate the antifungal effect, the antibiogram method involving various tests using a fungi mix of Aspergillus, Penicillium and Trichoderma species has been used. The presented method allows obtaining of some stable colloidal solutions containing up to 35 ppm of Ag with very good antimicrobial and antifungal properties.

  7. Microwave assisted template synthesis of silver nanoparticles

    Indian Academy of Sciences (India)

    Easier, less time consuming, green processes, which yield silver nanoparticles of uniform size, shape and morphology are of interest. Various methods for synthesis, such as conventional temperature assisted process, controlled reaction at elevated temperatures, and microwave assisted process have been evaluated for ...

  8. Reinforcement of Conducting Silver-based Materials

    Directory of Open Access Journals (Sweden)

    Heike JUNG

    2014-09-01

    Full Text Available Silver is a well-known material in the field of contact materials because of its high electrical and thermal conductivity. However, due to its bad mechanical and switching properties, silver alloys or reinforcements of the ductile silver matrix are required. Different reinforcements, e. g. tungsten, tungsten carbide, nickel, cadmium oxide or tin oxide, are used in different sectors of switches. To reach an optimal distribution of these reinforcements, various manufacturing techniques (e. g. powder blending, preform infiltration, wet-chemical methods, internal oxidation are being used for the production of these contact materials. Each of these manufacturing routes offers different advantages and disadvantages. The mechanical alloying process displays a successful and efficient method to produce particle-reinforced metal-matrix composite powders. This contribution presents the obtained fine disperse microstructure of tungsten-particle-reinforced silver composite powders produced by the mechanical alloying process and displays this technique as possible route to provide feedstock powders for subsequent consolidation processes. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.4889

  9. Characterization of Fe -doped silver phosphate glasses

    Indian Academy of Sciences (India)

    tures of the glass and at lower concentration of dopant, a nanostructure is obtained. Electrical conductivity mea- surements from 303 to 373 K in a frequency range from 100 Hz to 5 MHz have indicated that all glasses are ionic conductors with Ag+ ions as the charge carrier. Fe2O3 doping in silver phosphate glass increased ...

  10. Biosynthesis of silver nanoparticles synthesized by Aspergillus ...

    Indian Academy of Sciences (India)

    agents. Keywords. Aspergillus flavus; silver nanoparticles; antimicrobial; antioxidant; cytotoxicity. 1. Introduction. Nanoparticles with controlled size and composition are of fundamental and technological interest as they provide solu- tions to technological and environmental challenges in the areas of solar energy conversion ...

  11. Development and antibacterial performance of silver nanoparticles ...

    Indian Academy of Sciences (India)

    impregnation of silver nanoparticles (SNPs). This was done by applying a polymeric foundation on the polyester- knitted fabric by simply dip-coating in the aqueous solution of dopamine. Then the SNPs were in situ fabricated and impregnated on the surface of polydopamine-modified polyester-knitted fabric in an aqueous ...

  12. ELECTRO-GRAVIMETRIC RECOVERY OF SILVER FROM ...

    African Journals Online (AJOL)

    with gold and other metals. Generally, silver is associated with sulfides of Fe, As, Cu as well compounds of antimony and selenium [7]. Cyanide leaching, activated carbon and thiourea methods have been applied for effective leaching, adsorption and desorption of precious metals. In this regard an electrolytic cell holding.

  13. PIXE analysis of medieval silver coins

    Energy Technology Data Exchange (ETDEWEB)

    Abdelouahed, H. Ben, E-mail: habdelou@cern.ch [Centre National des Sciences et Technologies Nucleaires (CNSTN), Pole technologique, 2020 Sidi Thabet, Tunis (Tunisia); Gharbi, F. [Centre National des Sciences et Technologies Nucleaires (CNSTN), Pole technologique, 2020 Sidi Thabet, Tunis (Tunisia); Roumie, M. [IBA Laboratory, Lebanese Atomic Energy Commission, National Council for Scientific Research, 11-8281, Beirut (Lebanon); Baccouche, S. [Centre National des Sciences et Technologies Nucleaires (CNSTN), Pole technologique, 2020 Sidi Thabet, Tunis (Tunisia); Romdhane, K. Ben [Faculte des lettres et des sciences humaines, Universite de Tunis (Tunisia); Nsouli, B. [IBA Laboratory, Lebanese Atomic Energy Commission, National Council for Scientific Research, 11-8281, Beirut (Lebanon); Trabelsi, A. [Centre National des Sciences et Technologies Nucleaires (CNSTN), Pole technologique, 2020 Sidi Thabet, Tunis (Tunisia)

    2010-01-15

    We applied the proton-induced X-ray emission (PIXE) analytical technique to twenty-eight medieval silver coins, selected from the Tunisian treasury. The purpose is to study the fineness evolution from the beginning of the 7th to the 15th centuries AD. Each silver coin was cleaned with a diluted acid solution and then exposed to a 3 MeV proton beam from a 1.7 MV tandem accelerator. To allow the simultaneous detection of light and heavy elements, a funny aluminum filter was positioned in front of the Si(Li) detector entrance which is placed at 135{sup o} to the beam direction. The elements Cu, Pb, and Au were observed in the studied coins along with the major component silver. The concentration of Ag, presumably the main constituent of the coins, varies from 55% to 99%. This significant variation in the concentration of the major constituent reveals the economical difficulties encountered by each dynasty. It could be also attributed to differences in the composition of the silver mines used to strike the coins in different locations. That fineness evolution also reflects the poor quality of the control practices during this medieval period. In order to verify the ability of PIXE analytical method to distinguish between apparently similar coins, we applied hierarchical cluster analysis to our results to classify them into different subgroups of similar elemental composition.

  14. Preparation of amine coated silver nanoparticles using ...

    Indian Academy of Sciences (India)

    The product was characterized with X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), UVvisible spectroscopy, thermal gravimetric analysis (TGA) and transmission electron microscopy (TEM). Monocrystalline silver particles with cubic structure and an average size of 20 nm were obtained.

  15. Synthesis and characterization of silver molybdate nanowires ...

    Indian Academy of Sciences (India)

    Wintec

    organic free hydrothermal process using ammonium molybdate and silver nitrate solutions. The powder X-ray diffraction ... luminescence (PL) spectrum exhibits UV emission at 335 nm, violet emission at 408 nm and a weak green emission at 540 nm. ... Few reports are related to the synthesis of metal molybdates through ...

  16. Stability of Silver Nanoparticles as Imaging Materials

    Directory of Open Access Journals (Sweden)

    Umi Nur Sholikhah

    2016-09-01

    Full Text Available Determining the stability of silver nanoparticles is a very important process. It was associated with unwanted metal charge and materials properties. Therefore, we studied to synthesis and stability of silver nanoparticles (AgNPs. The synthesis was performed by reduction method used sodium borohydride (NaBH4. Silver nitrate solution 0.0005 M in 1 mL was reduced using 1 mL 0.002 M of NaBH4. Then a 40.0 mL of polyvinylpyrrolidone 0.3% and 20 mL of 1.5 N NaCl was added to the mixture. Characterization of silver nanoparticles is undertaken using spectrophotometer UV-Vis, transmission electron microscopy, particle size analyzer and zeta potential. The stability of products is observed for 5 times using spectrophotometer UV-Vis. The product was characterized by determining its surface plasmon resonance (SPR of AgNPs and the result was obtained at 403 nm. The size of AgNPs was 20 nm using tomography emission microscopy analysis and the particle size distribution give 5.8 nm. The dielectric charge was 53 mV. The stable AgNPs showed no significant SPR shift at 402±0.89 nm wavelength during 5 days observation. Based on the size and stability, it was suitable for imaging materials.

  17. Synthesis and Study of Silver Nanoparticles

    Science.gov (United States)

    Soloman, Sally D.; Bahadory, Mozghan; Jeyarajasingam, Aravindan V.; Rutkowsky, Susan A.; Boritz, Charles; Mulfinger, Lorraine

    2007-01-01

    A laboratory experiment was conducted in which the students synthesized yellow colloidal silver, estimate particle size using visible spectroscopy and studied aggregation effects. The students were thus introduced to nanotechnology along with other topics such as redox chemistry, limiting and excess reactants, spectroscopy and atomic size.

  18. Biological and electrical properties of biosynthesized silver ...

    Indian Academy of Sciences (India)

    In this work, silver nanoparticles (AgNPs) were synthesized biochemically at room temperature using aqueous extract of rhizome of Rheum australe plant. The as-synthesized AgNPs were further studied for their morphological, biological and electrical characterization. The morphological studies, such as scanning electron ...

  19. Anaerobic Toxicity of Cationic Silver Nanoparticles

    Science.gov (United States)

    The microbial toxicity of silver nanoparticles (AgNPs) stabilized with different capping agents was compared to that of Ag+ under anaerobic conditions. Three AgNPs were investigated: (1) negatively charged citrate-coated AgNPs (citrate-AgNPs), (2) minimally charged p...

  20. Aqueous dispersions of silver nanoparticles in polyelectrolyte ...

    Indian Academy of Sciences (India)

    In this report, we present the versatile and effective technique, using environmental friendly reductant glucose, to prepare stable silver nanodispersions by reduction of Ag+ ions. Alternant copolymers of maleic anhydride with vinyl acetate and styrene sulphonate sodium acid salt polyelectrolytes were synthesized in aqueous ...

  1. Electrosorption of tetraalkylammonium ions on silver iodide

    NARCIS (Netherlands)

    Keizer, de A.

    1981-01-01

    The object of the present investigations was to study the ef fect of the adsorption of charged organic ions on electrically charged, solid-liquid interfaces. To that end, symmetrical quater nary ammonium ions were adsorbed on a silver iodide-electrolyte interface at various

  2. Radon capture with silver exchanged zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Hedstroem, H. [Chalmers Univ. of Technology, Goeteborg (Sweden). Nuclear Chemistry; Foreman, M.; Ekberg, C. [Chalmers Univ. of Technology, Goeteborg (Sweden). Nuclear Chemistry; Chalmers Univ. of Technology, Goeteborg (Sweden). Industrial Materials Recycling; Ramebaeck, H. [Chalmers Univ. of Technology, Goeteborg (Sweden). Nuclear Chemistry; Chalmers Univ. of Technology, Goeteborg (Sweden). Industrial Materials Recycling; Swedish Defence Research Agency (FOI), Division of CBRN Defence and Security, Umeaa (Sweden)

    2012-07-01

    To enable laboratory work with larger amounts of {sup 226}Ra and its decay products, e.g., {sup 222}Rn and its daughters, these need to be captured in order to avoid unnecessary alpha contamination of the laboratory work space and ventilation systems. In this study, radon gas was pumped through a column filled with the silver exchanged zeolite called 'silver exchanged molecular sieves 13X' (Ag{sub 84}Na{sub 2}[(AlO{sub 2}){sub 86}(SiO{sub 2}){sub 106}].xH{sub 2}O). After exposure to radon, the radioactivity of the zeolite was measured repeatedly using high resolution gamma spectrometry. It was shown that radon was captured and retained in the silver exchanged zeolite. The zeolites' ability to retain radon was decreased by formation of metallic silver, caused by ionizing radiation. However, the zeolite was regenerated by heating and its radon capture ability was restored. The daughters of radon are not in gas phase and will hence stay on the column. (orig.)

  3. Study of environmental degradation of silver surface

    Energy Technology Data Exchange (ETDEWEB)

    Aguas, H.; Silva, R.J.C.; Viegas, M.; Pereira, L.; Fortunato, E.; Martins, R. [Materials Science Department, CENIMAT/I3N, FCT-UNL, Campus de Caparica (Portugal)

    2008-05-15

    To evaluate the evolution of a dark film formation on silver surface objects, several coupons were catalogued and place inside a museum, located in an urban area. The changes on these samples were measured by spectroscopic ellipsometry, in periods of months. This technique allows the reduction of the coupons exposure time, in several months, due to its high sensitivity to surface modifications, with acceptable results for the evaluation of its degradation. The thicknesses of the degradation layers and the optical properties of silver oxide, chloride and sulphide reference samples were determined using a mixture of Tauc-Lorentz and Drude models. The composition of the silver corrosion layer was determined by fitting the layer using a Bruggeman Effective Medium Approximation (BEMA) of the three products plus voids. It was found that the thickness of the layer depends in the placement of the coupons, namely, inside or outside displayers. The average film thickness after 6 months was of 180 Aa and 280 Aa, inside and outside the displayers, respectively. The main compounds found in the layers were the silver chlorides and sulphides, which composition changed with the thickness of the layer, and the exposition time. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. Biosynthesis of silver nanoparticles by Leishmania tropica

    African Journals Online (AJOL)

    ahmadcanon

    2013-11-27

    Nov 27, 2013 ... Biosynthesis and characterizations of nanoparticles have become an important branch of nanotechnology. A novel ... tropica for synthesis of silver nanoparticles was found to be higher; also this method was cost effective and easily scaled up ..... generation of nanoproduct in biomedical applications. Trends.

  5. Biological synthesis and characterization of silver nanoparticles ...

    Indian Academy of Sciences (India)

    The biosynthesis of silver nanoparticles (AgNPs) using plant extracts became one of the potential areas ... Biosynthesized AgNPs were characterized by the help of UV–visible spectroscopy for their stability and physicochemical ... spectroscopy, X-ray diffraction, scanning electron microscopy. The obtained results confirmed ...

  6. A systematic review of silver-containing dressings and topical silver agents (used with dressings) for burn wounds.

    Science.gov (United States)

    Aziz, Z; Abu, S F; Chong, N J

    2012-05-01

    Silver preparations are commonly used for burns, but evidence of their effectiveness remains poorly defined. The aim of the study was to evaluate the effectiveness of silver-containing dressings and topical silver for preventing infection and promoting healing in burns wounds through a meta-analysis of the available evidence. The Cochrane Central Register of Controlled Trials and relevant databases were searched. Drug companies and experts in this field were also contacted. Randomised controlled trials (RCTs) of silver dressings or topical silver (used with dressings) compared with non-silver dressings were eligible for inclusion. We identified 14 RCTs involving 877 participants. One small trial of a silver-containing dressing showed significantly better healing time compared to the control [MD -3.6; 95% CI -4.94 to -2.26 for partial thickness burns and MD -3.9; 95% CI -4.54 to -3.26 for superficial burns]. Topical silver showed significantly worse healing time compared to the non-silver group [WMD 3.96; 95% CI 2.41-5.51] and showed no evidence of effectiveness in preventing wounds infection [WMD 2.48; 95% CI 0.39-15.73]. Our review suggests that silver-containing dressings and topical silver were either no better or worse than control dressings in preventing wound infection and promoting healing of burn wounds. Copyright © 2011 Elsevier Ltd and ISBI. All rights reserved.

  7. Female reproductive disorders

    DEFF Research Database (Denmark)

    Crain, D Andrew; Janssen, Sarah J; Edwards, Thea M

    2008-01-01

    To evaluate the possible role of endocrine-disrupting compounds (EDCs) on female reproductive disorders emphasizing developmental plasticity and the complexity of endocrine-dependent ontogeny of reproductive organs. Declining conception rates and the high incidence of female reproductive...... disruptions warrant evaluation of the impact of EDCs on female reproductive health....

  8. Female Prisoners in Malaysia

    Science.gov (United States)

    Teh, Yik Koon

    2006-01-01

    This is a study on 422 female prisoners in peninsular Malaysia. More than half of the female prisoners are foreigners, mainly from Indonesia and Thailand. This study surveys the background of the respondents and identifies factors that may have influenced them to commit the offences. Female prisoners in Malaysia, particularly those who are…

  9. The Gender Wealth Gap Across European Countries

    OpenAIRE

    Schneebaum, Alyssa; Rehm, Miriam; Mader, Katharina; Hollan, Katarina

    2017-01-01

    This paper studies the gap in wealth between male and female single households using 2010 Household Finance and Consumption Survey data for eight European countries. In the raw data, a large gap emerges at the upper end of the unconditional distribution. While OLS estimates show no difference in average net wealth levels, quantile regressions at the 95th percentile yield mixed evidence for the gender wealth gap in different specifications. Labour market characteristics and participation in as...

  10. The behavior of silver nanotextiles during washing.

    Science.gov (United States)

    Geranio, L; Heuberger, M; Nowack, B

    2009-11-01

    The widespread use of silver nanoparticles (Ag-NPs) in commercial products, especially textiles, will likely result in an unknown spread of Ag into the environment. The quantification and characterization of the Ag released from nano-Ag-products is an important parameter needed to predict the effect of Ag-NPs on the environment. The aim of this study was to determine the amount and the form of Ag released during washing from nine fabrics with different ways of silver incorporation into or onto the fibers. The effect of pH, surfactants, and oxidizing agents was evaluated. The results show that little dissolution of Ag-NPs occurs under conditions relevant to washing (pH 10) with dissolved concentrations 10 times lower than at pH 7. However, bleaching agents such as hydrogen peroxide or peracetic acid (formed by the perborate/TAED system) can greatly accelerate the dissolution of Ag. The amount and form of Ag released from the fabrics as ionic and particulate Ag depended on the type of Ag-incorporation into the textile. The percentage of the total silver emitted during one washing of the textiles varied considerably among products (from less than 1 to 45%). In the washing machine the majority of the Ag (at least 50% but mostly >75%) was released in the size fraction >450 nm, indicating the dominant role of mechanical stress. A conventional silver textile did not show any significant difference in the size distribution of the released silver compared to many of the textiles containing nano-Ag. These results have important implications for the risk assessment of Ag-textiles and also for environmental fate studies of nano-Ag, because they show that under conditions relevant to washing, primarily coarse Ag-containing particles are released.

  11. Preparation of starch-stabilized silver nanoparticles from amylose-sodium palmitate inclusion complexes

    Science.gov (United States)

    Starch-stabilized silver nanoparticles were prepared from amylose-sodium palmitate complexes by first converting sodium palmitate to silver palmitate by reaction with silver nitrate and then reducing the silver ion to metallic silver. This process produced water solutions that could be dried and the...

  12. Fractionation of silver isotopes in native silver explained by redox reactions

    Science.gov (United States)

    Mathur, Ryan; Arribas, Antonio; Megaw, Peter; Wilson, Marc; Stroup, Steven; Meyer-Arrivillaga, Danilo; Arribas, Isabel

    2018-03-01

    Scant data exist on the silver isotope composition of native silver specimens because of the relative newness of the technique. This study increases the published dataset by an order of magnitude and presents 80 silver new isotope analyses from native silver originating from a diverse set of worldwide deposits (8 deposit types, 33 mining districts in five continents). The measured isotopic range (defined as δ109Ag/107Ag in per mil units compared to NIST 978 Ag isotope standard) is +2.1 to -0.86‰ (2σ errors less than 0.015); with no apparent systematic correlations to date with deposit type or even within districts. Importantly, the data centering on 0‰ all come from high temperature hypogene/primary deposits whereas flanking and overlapping data represent secondary supergene deposits. To investigate the causes for the more fractionated values, several laboratory experiments involving oxidation of silver from natural specimens of Ag-rich sulfides and precipitation and adsorption of silver onto reagent grade MnO2 and FeOOH were conducted. Simple leach experiments demonstrate little Ag isotope fractionation occurred through oxidation of Ag from native Ag (Δsolution-native109Ag = 0.12‰). In contrast, significant fractionation occurred through precipitation of native Ag onto MnO2 (up to Δsolution-MnO2109Ag = 0.68‰, or 0.3amu). Adsorption of silver onto the MnO2 and FeOOH did not produce as large fractionation as precipitation (mean value of Δsolution-MnO2109Ag = 0.10‰). The most likely cause for the isotopic variations seen relates to redox effects such as the reduction of silver from Ag (I) to Ag° that occurs during precipitation onto the mineral surface. Since many Ag deposits have halos dominated by MnO2 and FeOOH phases, potential may exist for the silver isotope composition of ores and surrounding geochemical haloes to be used to better understand ore genesis and potential exploration applications. Aside from the Mn oxides, surface fluid silver

  13. THE EUROPEAN BUSINESS CYCLE

    Directory of Open Access Journals (Sweden)

    Ignat Ion

    2009-05-01

    Full Text Available The construction of European Monetary Union has raised several questions about the existence of a common business cycle, a European one. The lack of cyclical synchronization would complicate the monetary and fiscal policies in the Union, being a negative

  14. European Home Energy

    DEFF Research Database (Denmark)

    Tommerup, Henrik M.

    2009-01-01

    An important aim of the european energy performance of buildings directive is to improve the overall energy efficiency of new homes......An important aim of the european energy performance of buildings directive is to improve the overall energy efficiency of new homes...

  15. European Industry, 1700 - 1870

    NARCIS (Netherlands)

    Broadberry, Stephen; Fremdling, Rainer; Solar, Peter M.

    2008-01-01

    This paper offers an overview of the development of European industry between 1700 and 1870, drawing in particular on the recent literature that has emerged following the formation of the European Historical Economics Society in 1991. The approach thus makes use of economic analysis and quantitative

  16. The European Programme Manager

    DEFF Research Database (Denmark)

    Larson, Anne; Bergman, E.; Ehlers, S.

    The publication is a result of a cooperation between organisations in six European countries with the aim to develop a common European education for programme managers. It contains of a description of the different elements of the education together with a number of case-studies from the counties...

  17. European works councils

    DEFF Research Database (Denmark)

    Knudsen, Herman Lyhne

    2003-01-01

    The theme adressed by this paper is the opportunities for European Works Councils (EWCs) of gaining influence on corporate decisions in multinational companies.......The theme adressed by this paper is the opportunities for European Works Councils (EWCs) of gaining influence on corporate decisions in multinational companies....

  18. European works councils

    DEFF Research Database (Denmark)

    Knudsen, Herman Lyhne

    2004-01-01

    The theme addressed by this artcle is the opportunities for European Works Councils of gaining influence on corporate decisions in multinational companies.......The theme addressed by this artcle is the opportunities for European Works Councils of gaining influence on corporate decisions in multinational companies....

  19. Introduction: European climate leadership

    NARCIS (Netherlands)

    Wurzel, R.K.W.; Liefferink, J.D.; Connelly, J.

    2017-01-01

    There is no shortage of would-be leaders in EU climate change politics. The EU institutions (e.g. European Council, Council of the EU, Commission and the European Parliament (EP)), member states and societal actors have all, though to varying degrees and at different time periods, tried to offer

  20. Europeanization : A Poststructuralist Approach

    NARCIS (Netherlands)

    Neuman-Stanivukovic, Senka

    2014-01-01

    This dissertation begins from the hypothesis that the direction and extent of Europeanization depends on domestic perception of the European Union and its norms. Accordingly, it was my empirical ambition to study how competing articulations of the EU and its norms constructed debates in EU member

  1. European media law

    NARCIS (Netherlands)

    Castendyk, O.; Dommering, E.; Scheuer, A.

    2008-01-01

    European Union legislation concerning electronic communications media is firmly established as an essential part of the law in the field in Europe. From relevant provisions of the European Convention of Human Rights and the EC Treaty to numerous directives, the most recent being the Audiovisual

  2. Acticoat dressings and major burns: systemic silver absorption.

    Science.gov (United States)

    Moiemen, Naiem S; Shale, Elizabeth; Drysdale, Kate J; Smith, Gary; Wilson, Yvonne T; Papini, Remo

    2011-02-01

    Despite widespread use of wound dressings containing silver, few studies have investigated patients' serum silver levels. An earlier study of Acticoat use in small burns showed transient elevations of serum silver. The aim of this study was to examine the serum silver profile when Acticoat is used in major burns. A prospective study of 6 patients with burns greater than 20% total body surface area (TBSA). All burn wounds, including grafted and non-grafted areas and skin graft donor sites, were dressed with Acticoat or Acticoat Absorbent. Patients' serum silver levels, biochemistry and haematology were examined before, during and after the application of the silver dressings. The median total wound size (including donor sites) was 46.1% TBSA. The median maximum serum silver level recorded, 200.3 μg/L, reached at a median of 9.5 days following initial silver dressing application. This decreased to a median of 164.8 μg/L at the end of the treatment period and to a median of 8.2 μg/L at the end of follow-up. One adverse event, partial skin graft loss was thought to be dressing related. In this small study, serum silver levels were elevated but remained similar to that reported following the use of silver sulfadiazine. This study confirmed our view that Acticoat is safe to use on patients with burns, even when they are extensive. Copyright © 2010 Elsevier Ltd and ISBI. All rights reserved.

  3. In situ synthesis of silver benzene-dithiolate hybrid films

    Energy Technology Data Exchange (ETDEWEB)

    Brenier, Roger, E-mail: roger.brenier@univ-lyon1.fr [Institut Lumière Matière, UMR 5306, Université Lyon 1-CNRS, Université de Lyon, Domaine Scientifique de La Doua, Batiment Kastler, 10 rue Ada Byron, 69622 Villeurbanne, Cedex (France); Piednoir, Agnès, E-mail: agnes.piednoir@univ-lyon1.fr [Institut Lumière Matière, UMR 5306, Université Lyon 1-CNRS, Université de Lyon, Domaine Scientifique de La Doua, Batiment Kastler, 10 rue Ada Byron, 69622 Villeurbanne, Cedex (France); Bertorelle, Franck, E-mail: franck.bertorelle@univ-lyon1.fr [Institut Lumière Matière, UMR 5306, Université Lyon 1-CNRS, Université de Lyon, Domaine Scientifique de La Doua, Batiment Kastler, 10 rue Ada Byron, 69622 Villeurbanne, Cedex (France); Penuelas, José, E-mail: jose.penuelas@ec-lyon.fr [Université de Lyon, Institut des Nanotechnologies de Lyon, Ecole Centrale de Lyon, CNRS, UMR 5270, 36 rue Guy de Collongues, F69134 Ecully (France); Grenet, Geneviève, E-mail: genevieve.grenet@ec-lyon.fr [Université de Lyon, Institut des Nanotechnologies de Lyon, Ecole Centrale de Lyon, CNRS, UMR 5270, 36 rue Guy de Collongues, F69134 Ecully (France)

    2016-02-01

    In this article, a method for in situ synthesis of silver benzene-dithiolate hybrid films is presented. Silver nanoparticles, generated on ZrO{sub 2} films, are transformed into silver benzene 1,4-dithiolate or, partially, into silver benzene 1,2-dithiolate after sample immersion in the corresponding thiol solutions. These transformations occur at room temperature owing to the catalytic action of ZrO{sub 2}. It is also shown that TiO{sub 2} in place of ZrO{sub 2} is very efficient, both for the catalytic generation of silver nanoparticles and for their further transformation in benzene 1,4-dithiolate compound. This latter semiconductor has an optical bandgap of about 3 eV and the film is made of touching nanoparticles in an amorphous state. Our work has potential applications in the electronic and photovoltaic fields. - Highlights: • A method for in situ synthesis of silver benzene-dithiolate hybrid semiconductor films is presented. • Silver nanoparticles are, first, generated on ZrO{sub 2} or on TiO{sub 2} coated silica substrates. • The samples are immersed in benzene dithiol solution for two days at room temperature. • During the immersion, the silver nanoparticles are transformed into silver benzene dithiolate. • The silver benzene dithiolate film is made of amorphous nanoparticles with a banbgap of 3 eV.

  4. Innovative phytosynthesized silver nanoarchitectures with enhanced antifungal and antioxidant properties

    Science.gov (United States)

    Ortan, Alina; Fierascu, Irina; Ungureanu, Camelia; Fierascu, Radu Claudiu; Avramescu, Sorin Marius; Dumitrescu, Ovidiu; Dinu-Pirvu, Cristina Elena

    2015-12-01

    While in the early era of nanotechnology, nanoparticles of noble metals were obtained through expensive methods, using toxic chemical reagents, in the last decade attempts are made to obtain the desired chemical composition, size, morphology, and other properties by eco and green synthesis, using plants. The aim of this paper is to compare two extraction methods (hydroalcoholic extraction and microwave extraction) used to phytosynthesize silver nanoparticles, in terms of nanoparticle (NP) morphology, antioxidant, and antifungal action, using an European native plant, Anthriscus cerefolium (L.) Hoffm. The extracts and the obtained NPs were characterized by modern analytical techniques (GC-MS, UV-Vis, SEM, TEM) and by phytochemical assays (total flavonoids, total terpenoids and total phenolic content). The antifungal activity (evaluated using the Kirby-Bauer method, against Aspergillus niger and Penicillium hirsutum) and the antioxidant activity (determined by the DPPH assay and a chemiluminescence assay) revealed notable differences between the samples, differences due to the extraction procedure followed. Also, preliminary studies regarding the stability and the toxicity of the nanoparticles are presented. By using the microwave-assisted extraction, not only smaller particles (less than 10 nm) were obtained, but also with better antifungal and antioxidant properties than the ones obtained by classical extraction.

  5. Speciation Matters: Bioavailability of Silver and Silver Sulfide Nanoparticles to Alfalfa (Medicago sativa).

    Science.gov (United States)

    Stegemeier, John P; Schwab, Fabienne; Colman, Benjamin P; Webb, Samuel M; Newville, Matthew; Lanzirotti, Antonio; Winkler, Christopher; Wiesner, Mark R; Lowry, Gregory V

    2015-07-21

    Terrestrial crops are directly exposed to silver nanoparticles (Ag-NPs) and their environmentally transformed analog silver sulfide nanoparticles (Ag2S-NPs) when wastewater treatment biosolids are applied as fertilizer to agricultural soils. This leads to a need to understand their bioavailability to plants. In the present study, the mechanisms of uptake and distribution of silver in alfalfa (Medicago sativa) were quantified and visualized upon hydroponic exposure to Ag-NPs, Ag2S-NPs, and AgNO3 at 3 mg total Ag/L. Total silver uptake was measured in dried roots and shoots, and the spatial distribution of elements was investigated using transmission electron microscopy (TEM) and synchrotron-based X-ray imaging techniques. Despite large differences in release of Ag(+) ions from the particles, Ag-NPs, Ag2S-NPs, and Ag(+) became associated with plant roots to a similar degree, and exhibited similarly limited (<1%) amounts of translocation of silver into the shoot system. X-ray fluorescence (XRF) mapping revealed differences in the distribution of Ag into roots for each treatment. Silver nanoparticles mainly accumulated in the (columella) border cells and elongation zone, whereas Ag(+) accumulated more uniformly throughout the root. In contrast, Ag2S-NPs remained largely adhered to the root exterior, and the presence of cytoplasmic nano-SixOy aggregates was observed. Exclusively in roots exposed to particulate silver, NPs smaller than the originally dosed NPs were identified by TEM in the cell walls. The apparent accumulation of Ag in the root apoplast determined by XRF, and the presence of small NPs in root cell walls suggests uptake of partially dissolved NPs and translocation along the apoplast.

  6. Topical antibiotic ointment versus silver-containing foam dressing for second-degree burns in swine.

    Science.gov (United States)

    Toussaint, Jimmy; Chung, Won Taek; Osman, Naureen; McClain, Steve A; Raut, Vivek; Singer, Adam J

    2015-08-01

    Second-degree burns are very common but their management is controversial. These burns may be treated with either topical antimicrobial agents or advanced occlusive dressings; however, there is no established treatment comparator for preclinical studies. This study was designed to determine which of two commonly used comparator therapies (a silver-containing advanced dressing or a topical antibiotic ointment) resulted in faster reepithelialization and less scarring. The hypothesis was that second-degree burns treated with a topical antimicrobial ointment would heal faster and with less scarring than those treated with a silver-containing occlusive foam dressing in a porcine model. Deep partial-thickness burns were created on the flanks of three anesthetized female domestic pigs (20 to 25 kg) using a 150-g aluminum bar preheated in 80°C water bath and applied to the skin for 20 seconds using a force of 2 kg. The burn eschars were excised 48 hours later with an electric dermatome set at a depth of 0.75 mm. The wound beds were treated with a thin layer of triple-antibiotic petrolatum-based ointment (changed three times weekly) or a silver-containing foam dressing (changed once weekly). Full-thickness punch biopsies were obtained at 9, 11, 14, 16, 18, and 21 days for determination of percentage complete wound reepithelialization and at 28 days for measurement of scar depth. At all dressing changes the wounds treated with the topical antibiotic appeared moist, while those treated with the silver-based dressings appeared dry. At day 21 all wounds treated with the ointment were completely reepithelialized, while only 55% of those treated with the silver dressing were reepithelialized (p dressing (mean ± SD = 25.0% ± 14.6% vs. 38.9% ± 16.9%, difference = 13.9%; 95% CI = 5.7% to 22.0%). In this model of excised deep partial-thickness burns, a triple-antibiotic ointment enhanced reepithelialization and reduced scar depth and contraction compared with a silver-based foam

  7. A novel green synthesis of silver nanoparticles using soluble starch and its antibacterial activity

    National Research Council Canada - National Science Library

    Yakout, Sobhy M; Mostafa, Ashraf A

    2015-01-01

    .... It was observed that use of starch makes convenient method for the synthesis of silver nanoparticles and can reduce silver ions into the produced silver nanoparticles within one hour of reaction time...

  8. In Vivo Toxicity of Silver Nanoparticles and Silver Ions in Zebrafish (Danio rerio

    Directory of Open Access Journals (Sweden)

    Katrine Bilberg

    2012-01-01

    Full Text Available The influence of water chemistry on characterised polyvinyl pyrrolidone- (PVP- coated silver nanoparticles (81 nm was investigated. NaCl solution series of 100–800 mg L−1 lead to initial and temporal increase in nanoparticles size, but agglomeration was limited. pH variation (5–8 had only minor influence on the hydrodynamic particle size. Acute toxicity of nanosivler to zebrafish (Danio rerio was investigated in a 48-hour static renewal study and compared with the toxicity of silver ions (AgNO3. The nanosilver and silver ion 48-hour median lethal concentration (LC50 values were 84 μg L−1 and 25 μg L−1, respectively. To investigate exposure-related stress, the fish behaviour was observed visually after 0, 3, 6, 12, 24, 27, 30, and 48 hours of both nanosilver and ionic silver treatments. These observations revealed increased rate of operculum movement and surface respiration after nanosilver exposure, suggesting respiratory toxicity. The present study demonstrates that silver nanoparticles are lethal to zebrafish.

  9. Impact of silver ions and silver nanoparticles on the plant growth and soil microorganisms

    Directory of Open Access Journals (Sweden)

    D. Tomacheski

    2017-12-01

    Full Text Available There is a growing consumer market for products that proclaim to decrease microorganism counts to prevent infections. Most of these products are loaded with silver in its ionic or nanoparticle form. Through use or during production, these particles can find their way into the soil and cause an impact in microbial and plant communities. This study aims to evaluate the impact of silver based particles in Avena byzantina (oat, Lactuca sativa (lettuce and Raphanus sativus (radish development and in the soil microorganism abundance. Oat, lettuce and radish plants were cultivated in soil contaminated with particles of bentonite organomodified with silver (Ag+_bentonite, silver phosphate glass (Ag+_phosphate and silver nanoparticles adsorbed on fumed silica (AgNp_silica. Plant development and microorganisms’ abundance were evaluated. To some degree, Ag+_bentonite impacted plants development and AgNp_silica causes an adverse effect on microbial abundance. The impact on plants and microorganisms was contradictory and varied according to soil and particles physicochemical characteristics.

  10. Femtosecond laser structuring of silver-containing glass: Silver redistribution, selective etching, and surface topology engineering

    Energy Technology Data Exchange (ETDEWEB)

    Desmoulin, Jean-Charles; Petit, Yannick; Cardinal, Thierry, E-mail: thierry.cardinal@icmcb.cnrs.fr [CNRS, ICMCB, UPR 9048, F-33600 Pessac, France and Univ. Bordeaux, ICMCB, UPR 9048, F-33600 Pessac (France); Canioni, Lionel [Université Bordeaux, Centre Lasers Intenses et Applications–UMR 5107 CNRS, 351 cours de la Libération, 33405 Talence Cedex (France); Dussauze, Marc [Université de Bordeaux, Institut des Sciences Moléculaires, CNRS UMR 5255, 351 cours de la Libération, 33405 Talence Cedex (France); Lahaye, Michel [Université de Bordeaux, Placamat, avenue Docteur Albert Schweitzer, 33608 Pessac Cedex (France); Gonzalez, Hernando Magallanes; Brasselet, Etienne [Université Bordeaux, Laboratoire Ondes et Matière d' Aquitaine–UMR 5798, CNRS, 351 cours de la Libération, 33405 Talence Cedex (France)

    2015-12-07

    Femtosecond direct laser writing in silver-containing phosphate glasses allows for the three-dimensional (3D) implementation of complex photonic structures. Sample translation along or perpendicular to the direction of the beam propagation has been performed, which led to the permanent formation of fluorescent structures, either corresponding to a tubular shape or to two parallel planes at the vicinity of the interaction voxel, respectively. These optical features are related to significant modifications of the local material chemistry. Indeed, silver depletion areas with a diameter below 200 nm were evidenced at the center of the photo-produced structures while photo-produced luminescence properties are attributed to the formation of silver clusters around the multiphoton interaction voxel. The laser-triggered oxidation-reduction processes and the associated photo-induced silver redistribution are proposed to be at the origin of the observed original 3D luminescent structures. Thanks to such material structuring, surface engineering has been also demonstrated. Selective surface chemical etching of the glass has been obtained subsequently to laser writing at the location of the photo-produced structures, revealing features with nanometric depth profiles and radial dimensions strongly related to the spatial distributions of the silver clusters.

  11. Formation of dense cellulose monolayers on silver surfaces

    Directory of Open Access Journals (Sweden)

    Soo Whan Choi

    2000-01-01

    Full Text Available The adsorption of a new cellulose derivative,6-O-(2,3-bis(thiosulfato propyl-oxy-2-hydroxy-propyl-cellulose (TSHP, onto silver surfaces was investigated by means of ellipsometry, contact angle measurements and X-ray photoelectron spectroscopy (XPS. The results showed that the formation of a dense TSHP monolayer on silver surfaces is an irreversible and slow process. Based on XPS results a model was proposed to explain the chemisorption of TSHP on silver substrates. This model considers the homolytical cleavage of the thiosulfate groups attached to the cellulose chains with the formation of thio radicals, which bind covalently to the silver surface. The formation of silver thiolates lead to a stable TSHP monolayer on silver surfaces.

  12. Toxicity of silver nanoparticles in monocytes and keratinocytes

    DEFF Research Database (Denmark)

    Orłowski, Piotr; Krzyzowska, Malgorzata; Winnicka, Anna

    2012-01-01

    Silver nanoparticles are of interest to be used as antimicrobial agents in wound dressings and coatings in medical devices, but potential adverse effects have been reported in the literature. The possible local inflammatory response to silver nanoparticles and the role of cell death in determining...... these effects are largely unknown. Effects of the mixture of silver nanoparticles of different sizes were compared in in vitro assays for cytotoxicity, caspase-1 and caspase-9 activity and bax expression. In all tested concentrations, silver nanoparticles were more toxic for RAW 264.7 monocytes than for 291.03C...... keratinocytes and induced significant caspase-1 activity and necrotic cell death. In keratinocytes, more significantly than in macrophages, silver nanoparticles led to increase of caspase-9 activity and apoptosis. These results indicate that effects of silver nanoparticles depend on the type of exposed cells...

  13. Silver nanoparticles-coated glass frits for silicon solar cells

    Science.gov (United States)

    Li, Yingfen; Gan, Weiping; Li, Biyuan

    2016-04-01

    Silver nanoparticles-coated glass frit composite powders for silicon solar cells were prepared by electroless plating. Silver colloids were used as the activating agent of glass frits. The products were characterized by X-ray diffraction, scanning electron microscopy, and differential scanning calorimetry. The characterization results indicated that silver nanoparticles with the melting temperature of 838 °C were uniformly deposited on glass frit surface. The particle size of silver nanoparticles could be controlled by adjusting the [Ag(NH3)2]NO3 concentration. The as-prepared composite powders were applied in the front side metallization of silicon solar cells. Compared with those based on pure glass frits, the solar cells containing the composite powders had the denser silver electrodes and the better silver-silicon ohmic contacts. Furthermore, the photovoltaic performances of solar cells were improved after the electroless plating.

  14. Step-reduced synthesis of starch-silver nanoparticles.

    Science.gov (United States)

    Raghavendra, Gownolla Malegowd; Jung, Jeyoung; Kim, Dowan; Seo, Jongchul

    2016-05-01

    In the present process, silver nanoparticles were directly synthesized in a single step by microwave irradiation of a mixture of starch, silver nitrate, and deionized water. This is different from the commonly adopted procedure for starch-silver nanoparticle synthesis in which silver nanoparticles are synthesized by preparing a starch solution as a reaction medium first. Thus, the additional step associated with the preparation of the starch solution was eliminated. In addition, no additional reducing agent was utilized. The adopted method was facile and straight forward, affording spherical silver nanoparticles with diameter below 10nm that exhibited good antibacterial activity. Further, influence of starch on the size of the silver nanoparticles was noticed. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Update of European bioethics

    DEFF Research Database (Denmark)

    Rendtorff, Jacob Dahl

    2015-01-01

    , the principles of autonomy, dignity, integrity and vulnerability are proposed as the most important ethical principles for respect for the human person in biomedical and biotechnological development. This approach to bioethics and biolaw is presented here in a short updated version that integrates the earlier......This paper presents an update of the research on European bioethics undertaken by the author together with Professor Peter Kemp since the 1990s, on Basic ethical principles in European bioethics and biolaw. In this European approach to basic ethical principles in bioethics and biolaw...... research in a presentation of the present understanding of the basic ethical principles in bioethics and biolaw....

  16. Democratic Citizenship: European referents

    Directory of Open Access Journals (Sweden)

    María PUIG GUTIÉRREZ

    2011-09-01

    Full Text Available Let’s sense beforehand in this article a tour concerning the educational European policies that favors the development of a democratic citizenship. The aim that we chase is to understand the way in which nowadays it is being interpreted and stimulated the Citizenship education from European Union. for it we offer a conceptual delimiting of «Citizenship education» and later, we show an analysis of the principal documents and materials elaborated principally by the Council of Europe that mark the way followed by European Union as for education for Democratic Citizenship (EDC.

  17. Silver fir and Douglas fir are more tolerant to extreme droughts than Norway spruce in south-western Germany.

    Science.gov (United States)

    Vitali, Valentina; Büntgen, Ulf; Bauhus, Jürgen

    2017-12-01

    Improving our understanding of the potential of forest adaptation is an urgent task in the light of predicted climate change. Long-term alternatives for susceptible yet economically important tree species such as Norway spruce (Picea abies) are required, if the frequency and intensity of summer droughts will continue to increase. Although Silver fir (Abies alba) and Douglas fir (Pseudotsuga menziesii) have both been described as drought-tolerant species, our understanding of their growth responses to drought extremes is still limited. Here, we use a dendroecological approach to assess the resistance, resilience, and recovery of these important central Europe to conifer species the exceptional droughts in 1976 and 2003. A total of 270 trees per species were sampled in 18 managed mixed-species stands along an altitudinal gradient (400-1200 m a.s.l.) at the western slopes of the southern and central Black Forest in southwest Germany. While radial growth in all species responded similarly to the 1976 drought, Norway spruce was least resistant and resilient to the 2003 summer drought. Silver fir showed the overall highest resistance to drought, similarly to Douglas fir, which exhibited the widest growth rings. Silver fir trees from lower elevations were more drought prone than trees at higher elevations. Douglas fir and Norway spruce, however, revealed lower drought resilience at higher altitudes. Although the 1976 and 2003 drought extremes were quite different, Douglas fir maintained consistently the highest radial growth. Although our study did not examine population-level responses, it clearly indicates that Silver fir and Douglas fir are generally more resistant and resilient to previous drought extremes and are therefore suitable alternatives to Norway spruce; Silver fir more so at higher altitudes. Cultivating these species instead of Norway spruce will contribute to maintaining a high level of productivity across many Central European mountain forests under

  18. Antimicrobial Bacterial Cellulose-Silver Nanoparticles Composite Membranes

    OpenAIRE

    Hernane S. Barud; Thaís Regiani; Marques, Rodrigo F. C.; Lustri, Wilton R.; Younes Messaddeq; Ribeiro, Sidney J.L.

    2011-01-01

    Antimicrobial bacterial cellulose-silver nanoparticles composite membranes have been obtained by “in situ” preparation of Ag nanoparticles from hydrolytic decomposition of silver nitrate solution using triethanolamine as reducing and complexing agent. The formation of silver nanoparticles was evidenced by the X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and absorption in the UV-Visible (350 nm to 600 nm). Thermal and mechanical properties toge...

  19. Characterizations of silver alloys used in modern Mexican coins

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza-Lopez, M.L. [Instituto Tecnologico de Queretaro, Avenida Tecnologico S/N, Queretaro, Qro, C.P. 76000 (Mexico); Centro de Fisica Aplicada y Tecnologia Avanzada, Departamento de Nanotecnologia, Universidad Nacional Autonoma de Mexico, Campus Juriquilla, Apdo. Postal 1-1010, Queretaro Qro. C.P. 76230 (Mexico); Perez-Bueno, J.J. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Parque Tecnologico Queretaro-Sanfandila, Pedro Escobedo, Qro., C.P. 760703 (Mexico); Rodriguez-Garcia, M.E., E-mail: marioga@fata.unam.mx [Departamento de Posgrado e Investigacion, Facultad de Ingenieria, Centro Universitario S/N, Queretaro, Qro (Mexico)

    2009-09-15

    This paper presents a complete methodology for the characterization of silver alloys used in modern coin production. Mexican coins with a nominal silver concentration from 10% to 99.99% were used in this study. Calibrated Glow Discharge Optical Emission Spectrometers were used to determine the chemical composition of the alloys as a function of the depth, while inductively coupled plasma was used to determine the total element composition in bulk. Scanning Electron Microscope was used to study the phase distributions in the different silver coins. According to Glow Discharge Optical Emission Spectrometers and inductively coupled plasma, the silver content found in the studied samples was consistently greater than that of the nominal silver content reported by the Mexican mint. This may lead to a review of the new methods of analysis used nowadays in contemporary coin minting. This result is very important because silver is increasing in value as metal and, considering the volume of production of silver coins, this may increase further as a consequence of a growing popular confidence in silver currency. In the case of silver studies, an advantage of the absence of silver detector in the Glow Discharge Optical Emission Spectrometers system is that it allows for the recalibration to have a better range of detection of other metals present in the alloys. A calibration curve using the copper content obtained by inductively coupled plasma (bulk) and Glow Discharge Optical Emission Spectrometers (depth profile) was performed. The relevance of control in modern silver coin minting was clarified, especially in minimizing the discrepancy between the nominal and the core fineness. The physical and chemical properties of the alloys studied are defined, revealing important variations in silver and copper contents. A new methodology and metrology for the control of coinage are suggested.

  20. Silver Nanoparticle Storage Stability in Aqueous and Biological Media

    Science.gov (United States)

    2015-06-22

    NAVAL MEDICAL RESEARCH UNIT SAN ANTONIO SILVER NANOPARTICLE STORAGE STABILITY IN AQUEOUS AND BIOLOGICAL MEDIA NATALIE A... Silver Nanoparticle au Arbitrary Units Da Dalton NaBH4 Sodium Borohydride Na3C6H5O7 · 2H2O Tribasic Sodium Citrate dihydrate PVP Poly...successfully incorporated into wound treatments to reduce infections. Dressings and implant coatings are being developed which integrate silver nanoparticles

  1. Towards localization of engineered silver nanoparticles in Pseudokirchneriella subcapitata

    DEFF Research Database (Denmark)

    Jensen, Louise Helene Søgaard; Sørensen, Sara Nørgaard; Hartmann, Nanna Isabella Bloch

    Silver nanoparticles have increased cytotoxic properties compared to larger particles. Reflecting these properties, engineered silver nanoparticles are now added to an increasing number of consumer products often labelled as anti-bacterial. These particles are presently considered the fastest...... growing nanotechnology application. Accordingly, silver nanoparticles are now postulated to be released into the sewerage systems and wider environment in increasing quantities. Here they could potentially interfere with aquatic life and this ongoing project aims to localize possible particles taken up...

  2. Electrocatalytic dechlorination of chloroacetic acids on silver nanodendrites electrode.

    Science.gov (United States)

    Liu, Benzhi; Ding, Cheng; Xiao, Bo; Cui, Liqiang; Wang, Min

    2014-04-01

    Silver nanodendrites were successfully prepared by electrodeposition on the glassy carbon electrode. The effects of synthesis parameters such as concentrations of reagents and applied potentials on the morphology and structure of silver nanodendrites have been investigated. Electrochemical experiments showed that silver nanodendrites electrode had extraordinary electrocatalytic activity toward the dechlorination of chloroacetic acids. The electrocatalytic hydrogenolysis mechanism was the main pathway for the dechlorination of chloroacetic acids. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Alcohol selective oxidation over modified foam-silver catalysts

    OpenAIRE

    Pestryakov, Alexeij N.; Bogdanchikova, Nina. E.; Knop-Gericke, Axel

    2004-01-01

    Catalysts based on silver supported on foam ceramics and modified by Zr, Ce and La oxides have been studied in the process of partial oxidation of methanol to formaldehyde. The foam catalysts exhibit high catalytic, mechanical and gas-dynamic properties exceeding the characteristics of conventional crystalline and supported silver samples. Modifying additives of Zr and Ce oxides raise activity and selectivity of the supported foam-silver catalyst as well as its stability during the prolonged ...

  4. Avance: silver hydropolymer dressing for critically colonized wounds.

    Science.gov (United States)

    Ballard, Kate; McGregor, Fiona

    Avance is a hydropolymer dressing that has a silver compound bonded into it. The silver acts as a bacterial shield to prevent bacterial invasion, and as a bacterial barrier to impede cross-infection. This article aims to give an overview of the use of silver in eradicating surface bacteria, and provides case study evidence of the use of Avance on the leg ulcers of two patients. Both patients had complex medical histories and underlying aetiologies that delayed the wound-healing process.

  5. Release of silver nanoparticles from outdoor facades.

    Science.gov (United States)

    Kaegi, Ralf; Sinnet, Brian; Zuleeg, Steffen; Hagendorfer, Harald; Mueller, Elisabeth; Vonbank, Roger; Boller, Markus; Burkhardt, Michael

    2010-09-01

    In this study we investigate the release of metallic silver nanoparticles (Ag-NP) from paints used for outdoor applications. A facade panel mounted on a model house was exposed to ambient weather conditions over a period of one year. The runoff volume of individual rain events was determined and the silver and titanium concentrations of 36 out of 65 runoff events were measured. Selected samples were prepared for electron microscopic analysis. A strong leaching of the Ag-NP was observed during the initial runoff events with a maximum concentration of 145 micro Ag/l. After a period of one year, more than 30% of the Ag-NP were released to the environment. Particles were mostly paint. Microscopic results indicate that the Ag-NP are likely transformed to considerably less toxic forms such as Ag2S. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  6. SILVER NANOPARTICLES AS PENICILLIN ACTION ENHANCERS

    Directory of Open Access Journals (Sweden)

    O. A. Vasylchenko

    2013-04-01

    Full Text Available Nowadays, the value of bactericidal nanomaterials research increases at the increasing number of bacteria strains resistant to the most highly potent antibiotics. In the review the characteristic of nanoparticles and methods for their production are done. The scope of nanoparticles application is observed, special attention is focused on silver nanoparticles usage in medicine, in particular, as bactericidal products. It is indicated that nanoparticles may have toxic effects. Much attention is paid to nanoparticles application in the treatment of various diseases, for example, for targeted drug delivery, wound healing, bone regeneration, local heating of tumors in cancer pathology, immune system stimulation, for antibodies, viruses, bacteria detection, for liquids filtration. Penicillins and their producers — Penicillium sp. characteristic is done. The mechanism of penicillin antimicrobial action is estimated. It is revealed that silver nanoparticles usage in combination with antibiotics, particularly penicillin, leads to antibiotics antibacterial activity increasing against gram-positive and gram-negative microorganisms.

  7. Silver Nanoparticles in Alveolar Bone Surgery Devices

    Directory of Open Access Journals (Sweden)

    Stefano Sivolella

    2012-01-01

    Full Text Available Silver (Ag ions have well-known antimicrobial properties and have been applied as nanostrategies in many medical and surgical fields, including dentistry. The use of silver nanoparticles (Ag NPs may be an option for reducing bacterial adhesion to dental implant surfaces and preventing biofilm formation, containing the risk of peri-implant infections. Modifying the structure or surface of bone grafts and membranes with Ag NPs may also prevent the risk of contamination and infection that are common when alveolar bone augmentation techniques are used. On the other hand, Ag NPs have revealed some toxic effects on cells in vitro and in vivo in animal studies. In this setting, the aim of the present paper is to summarize the principle behind Ag NP-based devices and their clinical applications in alveolar bone and dental implant surgery.

  8. Standard specification for silvered flat glass mirror

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This specification covers the requirements for silvered flat glass mirrors of rectangular shape supplied as cut sizes, stock sheets or as lehr ends and to which no further processing (such as edgework or other fabrication) has been done. 1.2 This specification covers the quality requirements of silvered annealed monolithic clear and tinted flat glass mirrors up to 6 mm (¼ in.) thick. The mirrors are intended to be used indoors for mirror glazing, for components of decorative accessories or for similar uses. 1.3 This specification does not address safety glazing materials nor requirements for mirror applications. Consult model building codes and other applicable standards for safety glazing applications. 1.4 Mirrors covered in this specification are not intended for use in environments where high humidity or airborne corrosion promoters, or both, are consistently present (such as swimming pool areas, ocean-going vessels, chemical laboratories and other corrosive environments). 1.5 The dimensional val...

  9. Silver from Ur of Ancient Mesopotamia.

    Science.gov (United States)

    Mellichamp, J W; Levey, M

    1963-10-04

    Silver jewelry from the Royal Tombs of Ur, about 2500 B.C., compares favorably in purity with present-day sterling, and it also met specifications recorded in cuneiform literatutre of a later period for similar objects. The original chemical composition has been greatly modified by corrosion, calcification, and chlorination. The source and diffusion of various elements detected were traced to study the original composition.

  10. Silver nanoparticles as penicillin action enhancers

    OpenAIRE

    O. A. Vasylchenko; V. V. Sologub; K. K. Vasylchenko

    2013-01-01

    Nowadays, the value of bactericidal nanomaterials research increases at the increasing number of bacteria strains resistant to the most highly potent antibiotics. In the review the characteristic of nanoparticles and methods for their production are done. The scope of nanoparticles application is observed, special attention is focused on silver nanoparticles usage in medicine, in particular, as bactericidal products. It is indicated that nanoparticles may have toxic effects. Much attentio...

  11. Silver Foam Technologies Healing Research Program

    Science.gov (United States)

    2009-09-01

    incorporated into the foam at sufficient concentrations without congealing. Open-ended hydrophilic foam sponges incorporating Zeolite and Silver Glass Beads...1: Research open-end hydrophilic foam: The result of this research has produced an open-end hydrophilic foam with an absorption ration of fifteen...quarter inch thick and ten inches in length, eight inches in width and one half inch thick. Task 2: Metalized open-end hydrophilic foam: Uniform

  12. Removal of silver nanoparticles by coagulation processes

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Qian; Li, Yan [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Tang, Ting [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); College of Earth and Environment, Anhui University of Science and Technology, Huainan 232001 (China); Yuan, Zhihua [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Yu, Chang-Ping, E-mail: cpyu@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China)

    2013-10-15

    Highlights: • This study investigated the removal of AgNP suspensions by four regular coagulants. • The optimal removal efficiencies for the four coagulants were achieved at pH 7.5. • The removal efficiency of AgNPs was affected by the natural water characteristics. • TEM and XRD showed that AgNPs or silver-containing NPs were adsorbed onto the flocs. -- Abstract: Commercial use of silver nanoparticles (AgNPs) will lead to a potential route for human exposure via potable water. Coagulation followed by sedimentation, as a conventional technique in the drinking water treatment facilities, may become an important barrier to prevent human from AgNP exposures. This study investigated the removal of AgNP suspensions by four regular coagulants. In the aluminum sulfate and ferric chloride coagulation systems, the water parameters slightly affected the AgNP removal. However, in the poly aluminum chloride and polyferric sulfate coagulation systems, the optimal removal efficiencies were achieved at pH 7.5, while higher or lower of pH could reduce the AgNP removal. Besides, the increasing natural organic matter (NOM) would reduce the AgNP removal, while Ca{sup 2+} and suspended solids concentrations would also affect the AgNP removal. In addition, results from the transmission electron microscopy and X-ray diffraction showed AgNPs or silver-containing nanoparticles were adsorbed onto the flocs. Finally, natural water samples were used to validate AgNP removal by coagulation. This study suggests that in the case of release of AgNPs into the source water, the traditional water treatment process, coagulation/sedimentation, can remove AgNPs and minimize the silver ion concentration under the well-optimized conditions.

  13. Fano resonances in planar silver nanosphere clusters

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Kui; Nordlander, Peter [Rice Quantum Institute, Laboratory for Nanophotonics, Houston (United States); Rice University, Department of Physics, Houston, TX (United States); Mirin, Nikolay A. [Rice Quantum Institute, Laboratory for Nanophotonics, Houston (United States); Rice University, Department of Chemistry, Houston, TX (United States)

    2010-08-15

    The plasmonic properties of silver nanosphere clusters are investigated using the finite element and the plasmon hybridization methods. The nanoparticle clusters are found to exhibit multiple plasmon resonances with large induced electromagnetic field enhancements. For symmetric clusters, we show how group theory can be used to identify the microscopic nature of the plasmon resonances. For larger clusters, we show that narrow Fano resonances are frequently present in their optical spectra. (orig.)

  14. Electrosorption of tetraalkylammonium ions on silver iodide

    OpenAIRE

    Keizer, de, R.J.W.

    1981-01-01

    The object of the present investigations was to study the ef fect of the adsorption of charged organic ions on electrically charged, solid-liquid interfaces. To that end, symmetrical quater nary ammonium ions were adsorbed on a silver iodide-electrolyte interface at various surface charges. The electrochemistry of this model interface is well developed in comparison with other solid liquid interfaces and it is very suited for fundamental electrosorption studies. Special a...

  15. Alternative Plasmonic Materials: Beyond Gold and Silver

    DEFF Research Database (Denmark)

    Naik, Gururaj V.; Shalaev, Vladimir M.; Boltasseva, Alexandra

    2013-01-01

    such as gold and silver, that exhibit metallic properties and provide advantages in device performance, design flexibility, fabrication, integration, and tunability. This review explores different material classes for plasmonic and metamaterial applications, such as conventional semiconductors, transparent...... conducting oxides, perovskite oxides, metal nitrides, silicides, germanides, and 2D materials such as graphene. This review provides a summary of the recent developments in the search for better plasmonic materials and an outlook of further research directions....

  16. LL37 peptide@silver nanoparticles : combining the best of the two worlds for skin infection control

    OpenAIRE

    Vignoni, Mariana; de Alwis Weerasekera, Hasitha; Simpson, Madeline J.; Phopase, Jaywant; Mah, Thien-Fah; Griffith, May; Alarcon, Emilio I.; Scaiano, Juan

    2014-01-01

    Capping silver nanoparticles with LL37 peptide eradicates the anti-proliferative effect of silver on primary skin cells, but retains the bactericidal properties of silver nanoparticles with activities comparable to silver nitrate or silver sulfadiazine. In addition, LL37 capped silver nanoparticles have anti-biofilm formation activity.

  17. Rapid synthesis of silver nanoparticles from Polylthia longifolia leaves

    Directory of Open Access Journals (Sweden)

    Tollamadugu Nagavenkata

    2012-10-01

    Full Text Available Objective: Metallic nanoparticles are traditionally synthesized by wet chemical techniques, where the chemicals used are quite often toxic and flammable. In this research article we present a simple and eco-friendly biosynthesis of silver nanoparticles using P. longifolia leaf extract as reducing agent. Methods: Characterization using UV-Vis spectrophotometry, Transmission Electron Microscopy (TEM was performed. Results: TEM showed the formation of silver nanoparticles with an average size of 57 nm. Conclusions: P. longifolia demonstrated strong potential for synthesis of silver nanoparticles by rapid reduction of silver ions (Ag+ to Ag0. Biological methods are a good competent for the chemical procedures, which are enviro- friendly and convenient.

  18. Synthesis of silver nanoparticles using medicinal Zizyphus xylopyrus bark extract

    Science.gov (United States)

    Sumi Maria, Babu; Devadiga, Aishwarya; Shetty Kodialbail, Vidya; Saidutta, M. B.

    2015-08-01

    In the present paper, biosynthesis of silver nanoparticles using Zizyphus xylopyrus bark extract is reported. Z. xylopyrus bark extract is efficiently used for the biosynthesis of silver nanoparticles. UV-Visible spectroscopy showed surface plasmon resonance peaks in the range 413-420 nm confirming the formation of silver nanoparticles. Different factors affecting the synthesis of silver nanoparticles like methodology for the preparation of extract, concentration of silver nitrate solution used for biosynthesis and initial pH of the reaction mixture were studied. The extract prepared with 10 mM AgNO3 solution by reflux extraction method at optimum initial pH of 11, resulted in higher conversion of silver ions to silver nanoparticles as compared with those prepared by open heating or ultrasonication. SEM analysis showed that the biosynthesized nanoparticles are spherical in nature and ranged from 60 to 70 nm in size. EDX suggested that the silver nanoparticles must be capped by the organic components present in the plant extract. This simple process for the biosynthesis of silver nanoparticles using aqueous extract of Z. xylopyrus is a green technology without the usage of hazardous and toxic solvents and chemicals and hence is environment friendly. The process has several advantages with reference to cost, compatibility for its application in medical and drug delivery, as well as for large-scale commercial production.

  19. The antifungal effect of silver nanoparticles on Trichosporon asahii.

    Science.gov (United States)

    Xia, Zhi-Kuan; Ma, Qiu-Hua; Li, Shu-Yi; Zhang, De-Quan; Cong, Lin; Tian, Yan-Li; Yang, Rong-Ya

    2016-04-01

    Silver nanoparticles are receiving increasing attention in biomedical applications. This study aims at evaluating the antifungal properties of silver nanoparticles against the pathogenic fungus Trichosporon asahii. The growth of T. asahii on potato dextrose agar medium containing different concentrations of silver nanoparticles was examined and the antifungal effect was evaluated using minimum inhibitory concentration. Scanning and transmission electron microscopy were also used to investigate the antifungal effect of silver nanoparticles on T. asahii. Silver nanoparticles had a significant inhibitory effect on the growth of T. asahii. The minimum inhibitory concentration of silver nanoparticles against T. asahii was 0.5 μg/mL, which was lower than amphotericin B, 5-flucytosine, caspofungin, terbinafine, fluconazole, and itraconazole and higher than voriconazole. Silver nanoparticles obviously damaged the cell wall, cell membrane, mitochondria, chromatin, and ribosome. Our results demonstrate that silver nanoparticles have good antifungal activity against T. asahii. Based on our electron microscopy observations, silver nanoparticles may inhibit the growth of T. asahii by permeating the fungal cell and damaging the cell wall and cellular components. Copyright © 2014. Published by Elsevier B.V.

  20. Silver nanoparticles are broad-spectrum bactericidal and virucidal compounds

    National Research Council Canada - National Science Library

    Lara, Humberto H; Garza-Treviño, Elsa N; Ixtepan-Turrent, Liliana; Singh, Dinesh K

    2011-01-01

    .... Interactions between viral biomolecules and silver nanoparticles suggest that the use of nanosystems may contribute importantly for the enhancement of current prevention of infection and antiviral therapies...

  1. Immobilizing silver nanoparticles (SNP) on Musa balbisiana cellulose.

    Science.gov (United States)

    Gogoi, Krishna; Saikia, Jyoti Prasad; Konwar, Bolin Kumar

    2013-02-01

    Cellulose from Musa balbisiana was purified. A part of it was dispersed in distilled water using ultrasonication. The silver nanoparticles (SNP) were synthesized in the colloidal cellulose solution and stability of the nanoparticles was tested using UV-Vis spectrophotometer. Further characterization of the composite was done using spectral analysis by Fourier Transform Infrared Spectroscopy (FTIR) to reveal any bond formation between silver nanoparticles with M. balbisiana cellulose. Here we found that cellulose/silver nanoparticle colloid is stable for 29 days and there is no chemical interaction of cellulose with silver nanoparticles. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Fungal mediated biosynthesis of silver nanoparticles, characterization and antimicrobial activity.

    Science.gov (United States)

    Jaidev, L R; Narasimha, G

    2010-12-01

    Microbial assisted biosynthesis of nanoparticles is a rapidly progressing area of nanobiotechnology. In this paper Aspergillus niger assisted extracellular synthesis of silver nanoparticles is reported. The silver nanoparticles were characterized by UV-vis spectrophotometry, TEM, EDX and FTIR. TEM studies showed the size of the silver nanoparticles to be in the range of 3-30 nm. The probable mechanism for the extracellular synthesis of silver nanoparticles by Aspergillus niger was investigated. The nanoparticles showed antimicrobial activity against fungal and bacterial strains. Copyright © 2010 Elsevier B.V. All rights reserved.

  3. Tuning of optical properties of PMMA by incorporating silver nanoparticles

    Science.gov (United States)

    Alisha, Rozra, Jyoti; Saini, Isha; Sharma, Annu; Sharma, Pawan

    2012-06-01

    Nanocomposite films of Poly (methylmethacrylate) filled with different concentration of silver nanoparticles were prepared by ex-situ method. Firstly, silver nanoparticles were obtained by reducing the aqueous solution of silver nitrate with sodium borohydride then Ag/PMMA films were prepared by mixing colloidal solution of silver nanoparticles with solution of polymer. From absorption and specular reflection spectra, the optical band gap and refractive index (n) have been calculated. The decrease in optical bandgap and increase in refractive index has been indicative of the modifications in optical band structure of the PMMA matrix.

  4. Green synthesis of silver nanoparticles and their characterization by XRD

    Science.gov (United States)

    Mehta, B. K.; Chhajlani, Meenal; Shrivastava, B. D.

    2017-05-01

    A cost effective and environment friendly technique for green synthesis of silver nanoparticles has been reported. Silver nanoparticles have been synthesized using ethanol extract of fruits of Santalum album (Family Santalaceae), commonly known as East Indian sandalwood. Fruits of S.album were collected and crushed. Ethanol was added to the crushed fruits and mixture was exposed to microwave for few minutes. Extract was concentrated by Buchi rotavaporator. To this extract, 1mM aqueous solution of silver nitrate (AgNO3) was added. After about 24 hr incubation Ag+ ions in AgNO3 solution were reduced to Ag atoms by the extract. Silver nanoparticles were obtained in powder form. X-ray diffraction (XRD) pattern of the prepared sample of silver nanoparticles was recorded The diffractogram has been compared with the standard powder diffraction card of JCPDS silver file. Four peaks have been identified corresponding to (hkl) values of silver. The XRD study confirms that the resultant particles are silver nanoparticles having FCC structure. The average crystalline size D, the value of the interplanar spacing between the atoms, d, lattice constant and cell volume have been estimated. Thus, silver nanoparticles with well-defined dimensions could be synthesized by reduction of metal ions due to fruit extract of S.album.

  5. The Adsorption of Argon and Oxygen on Silver Mordenite

    Science.gov (United States)

    1990-01-01

    argon and oxygen using 5A or 13X zeolites . Silver mordenite was studied as an alternative to the conventional adsorbents. Silver mordenite was...the history and development of PSA, see Yang [3] or Collins [4]). In the case of oxygen production using zeolite 5A or 13X , for example [5], air is...difficulty in separating argon and oy, ’gPn using 5A or 13X zeulites. Silver mordenitc was studied as an alternative to the conventional adsorbents. Silver

  6. Dielectric elastomeric bimorphs using electrolessly deposited silver electrodes

    Science.gov (United States)

    Goh, Simon Chun-Kiat; Lau, Gih-Keong

    2010-04-01

    Metallic thin films, which are widely used for micro-electronics circuits, are seldom used as the electrodes for dielectric elastomer actuators (DEA). This is because metalized film restrains the lateral strain of soft dielectric elastomer. In this paper, we demonstrated utilizing metalized elastomeric layers to make a bimorph capable of a large bending. A compliant silver electrode is deposited on onto a VHB tape (F-9469 PC) using electroless deposition method, as for mirror silvering. The deposited silver is 200 nm thick and highly conductively though having an uneven surface. A silvered DEA bimorph is made of an active layer of silvered VHB elastomers and a passive layer of polydimethylsiloxane (PDMS). Experiments show that the silvered dielectric elastomer actuator is capable of producing a large bending, with a curvature of 32 mm for a 20 mm length at a driving voltage of 3000V. In addition, the electrolessly silvered elastomeric capacitor (130 μm thick VHB as dielectric) exhibits a breakdown voltage of 4kV, higher than 2kV of the silver-greased capacitor. In addition, the silvered VHB layer is found to be able to self clear after electrical breakdown. It remains functional at a lower voltage after surviving an electrical breakdown.

  7. Phytochemical Synthesis and Preliminary Characterization of Silver Nanoparticles Using Hesperidin

    OpenAIRE

    Anish Stephen; Sankar Seethalakshmi

    2013-01-01

    This paper is the first of its kind for development of rapid and ecofriendly method for synthesis of silver nanoparticles from aqueous solution of silver nitrate using the flavonoid “hesperidin” and optimization of the methodology. There is formation of stable spherical silver nanoparticles in the size range of 20–40 nm. Optimization of methodology in terms of concentration of reactants and pH of the reaction mixture reduced the reaction time for silver nanoparticle formation to 2 mins. Silve...

  8. The silver layers in fiber-optic sensors

    Science.gov (United States)

    Listewnik, Paulina; Aydoǧan, Melike; Majchrowicz, Daria; Jedrzejewska-Szczerska, Małgorzata

    2017-12-01

    In this paper a method of deposition of the silver layers on the surface of an optical fiber was proposed. The optical properties and surface quality of the silver layer was examined by optical microscopy. The reflection and transmission of the sample were investigated. To investigate the quality the silver mirror it was placed in a fiber-optic Fabry-Perot interferometer and the quality of the spectra was analyzed. The commercial mirror was used as a reference reflective layer. Our studies confirm that the silver layer obtained in laboratory can be used for the application in the fiber-optic sensor and it is just as good as commercial mirror.

  9. Separation of silver ions and starch modified silver nanoparticles using high performance liquid chromatography with ultraviolet and inductively coupled mass spectrometric detection

    Science.gov (United States)

    Hanley, Traci A.; Saadawi, Ryan; Zhang, Peng; Caruso, Joseph A.; Landero-Figueroa, Julio

    2014-10-01

    The production of commercially available products marketed to contain silver nanoparticles is rapidly increasing. Species-specific toxicity is a phenomenon associated with many elements, including silver, making it imperative to develop a method to identify and quantify the various forms of silver (namely, silver ions vs. silver nanoparticles) possibly present in these products. In this study a method was developed using high performance liquid chromatography (HPLC) with ultraviolet (UV-VIS) and inductively coupled mass spectrometric (ICP-MS) detection to separate starch stabilized silver nanoparticles (AgNPs) and silver ions (Ag+) by cation exchange chromatography with 0.5 M nitric acid mobile phase. The silver nanoparticles and ions were baseline resolved with an ICP-MS response linear over four orders of magnitude, 0.04 mg kg- 1 detection limit, and 90% chromatographic recovery for silver solutions containing ions and starch stabilized silver nanoparticles smaller than 100 nm.

  10. Electrochemical Cycling of Polycrystalline Silver Nanoparticles Produces Single-Crystal Silver Nanocrystals.

    Science.gov (United States)

    Singh, Poonam; Carpenter, Ray W; Buttry, Daniel A

    2017-11-13

    Electrochemically driven phase transformations in redox-active nanoparticles (NPs) are important in a number of areas, including batteries and sensors. We use high-resolution electron microscopy in conjunction with ex situ electrochemical experiments on TEM grids to study the oxidative conversion of polycrystalline silver NPs to amorphous silver oxide nanoparticles and their reductive conversion back to single-crystal silver nanocrystals (NCs). Results show that during oxidation nucleation occurs uniformly at the NP surface, producing a Ag@Ag2O core@shell structure during growth. The images reveal polycrystalline Ag cores and amorphous Ag2O shells for these structures. Electron microscopy also showed that the electrochemical reduction of Ag2O NPs can produce single-crystal Ag nanocrystals, suggesting that point nucleation at the NP-electrode interface during reduction enables a growth mechanism favoring the formation of single-crystal nanoparticles.

  11. Kyllinga brevifolia mediated greener silver nanoparticles

    Science.gov (United States)

    Isa, Norain; Bakhari, Nor Aziyah; Sarijo, Siti Halimah; Aziz, Azizan; Lockman, Zainovia

    2017-12-01

    Kyllinga brevifolia extract (KBE) was studied in this research as capping as well as reducing agent for the synthesis of greener plant mediated silver nanoparticles. This research was conducted in order to identify the compounds in the KBE that probable to work as reductant for the synthesis of Kyllinga brevifolia-mediated silver nanoparticles (AgNPs). Screening test such as Thin Layer Chromatography (TLC), Fourier Transform Infra-Red (FTIR), Carlo Erba Elemental analysis and Gas Chromatography-Mass Spectroscopy (GCMS) were used in identifying the natural compounds in KBE. The as-prepared AgNPs were characterized by UV-vis spectroscopy (UV-vis), Transmission Electron Microscope (TEM) and X-ray Diffraction (XRD). The TEM images showed that the as-synthesized silver have quasi-spherical particles are distributed uniformly with a narrow distribution from 5 nm to 40 nm. The XRD results demonstrated that the obtained AgNPs were face centre-cubic (FCC) structure. The catalytic activity of AgNPs on reduction of methylene blue (MB) using sodium borohydride (SB) was analyzed using UV-vis spectroscopy. This study showed that the efficacy of mediated AgNPs in catalysing the reduction of MB.

  12. Cysteine sensing by plasmons of silver nanocubes

    Energy Technology Data Exchange (ETDEWEB)

    Elfassy, Eitan, E-mail: eitan.elfassi@gmail.com; Mastai, Yitzhak, E-mail: Yitzhak.Mastai@biu.ac.il; Salomon, Adi, E-mail: adi.salomon@biu.ac.il

    2016-09-15

    Noble metal nanoparticles are considered to be valuable nanostructures in the field of sensors due to their spectral response sensitivity to small changes in the surrounding refractive index which enables them to detect a small amount of molecules. In this research, we use silver nanocubes of about 50 nm length to detect low concentrations of cysteine, a semi-essential amino acid. Following cysteine adsorption onto the nanocubes, a redshift in the plasmonic modes was observed, enabling the detection of cysteine down to 10 µM and high sensitivity of about 125 nm/RIU (refractive index units). Furthermore, we found that multilayer adsorption of cysteine leads to the stabilization of the silver nanocubes. The cysteine growth onto the nanocubes was also characterized by high-resolution transmission electron microscopy (HR-TEM). - Highlights: • Silver nanocubes (50 nm length) are used to detect low concentrations of cysteine. • A redshift in the plasmonic modes was observed following cysteine adsorption onto the nanocubes. • The cysteine growth onto the nanocubes is also characterized by TEM.

  13. Silver Nanoparticles as Potential Antibacterial Agents

    Directory of Open Access Journals (Sweden)

    Gianluigi Franci

    2015-05-01

    Full Text Available Multi-drug resistance is a growing problem in the treatment of infectious diseases and the widespread use of broad-spectrum antibiotics has produced antibiotic resistance for many human bacterial pathogens. Advances in nanotechnology have opened new horizons in nanomedicine, allowing the synthesis of nanoparticles that can be assembled into complex architectures. Novel studies and technologies are devoted to understanding the mechanisms of disease for the design of new drugs, but unfortunately infectious diseases continue to be a major health burden worldwide. Since ancient times, silver was known for its anti-bacterial effects and for centuries it has been used for prevention and control of disparate infections. Currently nanotechnology and nanomaterials are fully integrated in common applications and objects that we use every day. In addition, the silver nanoparticles are attracting much interest because of their potent antibacterial activity. Many studies have also shown an important activity of silver nanoparticles against bacterial biofilms. This review aims to summarize the emerging efforts to address current challenges and solutions in the treatment of infectious diseases, particularly the use of nanosilver antimicrobials.

  14. A new neutron monitor with silver activation

    CERN Document Server

    Luszik-Bhadra, M; Hohmann, E

    2010-01-01

    A moderator-type neutron monitor has been developed, which registers delayed beta rays from neutron-induced silver activation and which is able to measure dose equivalent in pulsed fields with peak dose rates of several thousand Sv h(-1). The monitor uses four silicon diodes in the centre of a polyethylene moderator, 30 cm in diameter. Two of the diodes are covered by natural silver foils and two of them by tin foils. The latter are used to subtract photon-induced pulses. For registering signals, a pulse height threshold is set at 662 key, which minimizes the effect of Cs-137 and lower energy radiation and - in addition - enhances the detection of beta rays from the shorter half-life silver isotope Ag-110 (25 s) as compared to the longer half-life isotope Ag-108 (144 s). The results of measurements in neutron and photon calibration fields, of MCNPX neutron response calculations and of first measurements in a high-intensity pulsed field at the PSI accelerator are shown. (c) 2010 Elsevier Ltd. All rights reserv...

  15. Silver enhancement of nanogold and undecagold

    Energy Technology Data Exchange (ETDEWEB)

    Hainfield, J.F.; Furuya, F.R.

    1995-07-01

    A recent advance in immunogold technology has been the use of molecular gold instead of colloidal gold. A number of advantages are realized by this approach, such as stable covalent, site-specific attachment, small probe size and absence of aggregates for improved penetration. Silver enhancement has led to improved and unique results for electron and light microscopy, as well as their use with blots and gels. Most previous work with immunogold silver staining has been done with colloidal gold particles. More recently, large gold compounds (``clusters``) having a definite number of gold atoms and defined organic shell, have been used, frequently with improved results. These gold dusters, large compared to simple compounds, are, however, at the small end of the colloidal gold scale in size; undecagold is 0.8 nm and Nanogold is 1.4 nm. They may be used in practically all applications where colloidal gold is used (Light and electron microscopy, dot blots, etc.) and in some unique applications, where at least the larger colloidal golds don`t work, such as running gold labeled proteins on gels (which are later detected by silver enhancement). The main differences between gold clusters and colloidal golds are the small size of the dusters and their covalent attachment to antibodies or other molecules.

  16. Thermoluminescence of X irradiated chlorapatite containing silver

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Y.; Mizuguchi, K.; Yokota, S.; Takeuchi, N.

    1987-01-01

    Thermoluminescence (TL) of sintered calcium chlorapatites doped with 0.03 wt% silver and appreciable amounts of sodium ions have been investigated, because the effective atomic number of calcium chlorapatite is close to that of human bones and teeth. The presence of silver ions increases the sensitivity of the TL peaks to radiation dose, but the peak temperatures are not affected by the activators. For the sake of comparison, CuCl/sub 2/ and NdCl/sub 3/ doped samples were made and their TL glow curves were measured. They showed the same peak temperatures at 65 and 170/sup 0/C as the silver doped sample, but the intensities were different. These results may indicate that the charge carriers should be holes which are trapped by matrices of the samples. Electrons are trapped by the metal activators, some of which are detected by ESR. The linear response of the TL peak at 170/sup 0/C relative to exposure was observed up to about 2.58 C.kg/sup -1/. About 85% of the original intensity after an irradiation of 2.58 x 10/sup -2/C.kg/sup -1/ was preserved for 30 days at room temperature in the dark. This material could therefore be used for a TL dosemeter.

  17. Preparation of Silver Nanostructures from Bicontinuous Microemulsions

    Directory of Open Access Journals (Sweden)

    M. A. Pedroza-Toscano

    2012-01-01

    Full Text Available Precipitation of silver nanoparticles at 70°C was carried out by dosing a 1.3 M sodium borohydride aqueous solution over bicontinuous microemulsions formed with a mixture of sodium bis(2-ethylhexyl sulfosuccinate (AOT and sodium dodecylsulfate (SDS as surfactants, a 0.5 M silver nitrate aqueous solution, and toluene. Weight ratios of 2.5/1 and 3/1 AOT/SDS were used in the precipitation reactions. Silver nanoparticles were characterized by transmission electronic microscopy, X-ray diffraction, and atomic absorption spectroscopy. A mixture of isolated spheroidal nanoparticles (≈15 wt.% with an average diameter around 10 nm and wormlike structures (≈85 wt.% with an average length close to 480 nm and an average diameter ca. 40 nm was obtained, regardless of the AOT/SDS ratio. Higher yields were obtained compared with those reported when reverse microemulsions were employed. Formation of wormlike structures was ascribed to one-dimensional aggregation of crystal and particles within the channels of bicontinuous microemulsions, which performed as templates.

  18. CERN welcomes European science

    CERN Multimedia

    2002-01-01

    On 3 and 4 October CERN will host a special workshop for Marie Curie fellows. This programme is a key plank in the EU's strategy for creating a European research area.     With thousands of scientists from all over the continent working together, CERN is already an exemplary European science showcase. On 3 and 4 October, the Laboratory will contribute further to unifying all European science by hosting a special workshop for EU-funded Marie Curie fellows. This scheme gives young researchers from around the continent the mobility to go to wherever Europe's best facilities in their chosen field happen to be. The event that will take place at CERN, entitled 'Special workshop of Marie Curie Fellows on research and training in physics and technology', organised together with the European Commission, is a continuation of a series of workshops with the aim, among others, of promoting young researchers, supporting their training and mobility, and facilitating the interdisciplinary dissemination of knowledge. Dur...

  19. European Economic Integration

    Science.gov (United States)

    Huston, James A.

    1971-01-01

    Recounts the history and problems of European Economic Integration from the first post World War II organization, the OEEC, to the EEC (Common Market) and the EFTA. Suggestions for further reading are included. (JB)

  20. European Molecular Biology Laboratory

    CERN Multimedia

    1973-01-01

    On 10 May an Agreement was signed at CERN setting up a new European Laboratory. It will be concerned with research in molecularbiology and will be located at Heidelberg in the Federal Republic of Germany.

  1. The European University Landscape

    DEFF Research Database (Denmark)

    Daraio, Cinzia; Bonaccorsi, Andrea; Geuna, Aldo

    2011-01-01

    This paper provides a new and systematic characterization of 488 universities, from 11 European countries: Finland, France, Germany, Hungary, Italy, Netherlands, Norway, Portugal, Spain, Switzerland and UK. Using micro indicators built on the integrated Aquameth database, we characterize the Euro...

  2. European mobility cultures

    DEFF Research Database (Denmark)

    Haustein, Sonja; Nielsen, Thomas A. Sick

    2016-01-01

    More targeted European policies promoting green travel patterns require better knowledge on differing mobility cultures across European regions. As a basis for this, we clustered the EU population into eight mobility styles based on Eurobarometer data. The mobility styles - including, for example......-economic resources. In a second step, the 28 EU member countries were clustered into six country clusters based on their representation of mobility styles. The country clusters indicate the existence of considerably different mobility cultures across the EU. Sub-regions can be identified that have highly different...... positions on the path towards sustainable mobility and therefore different requirements towards European platforms and support measures, e.g. for 'Sustainable Urban Mobility Plans'. The country clusters can provide a starting point for future communication and targeting of European efforts in sustainable...

  3. Sponge-like silver obtained by decomposition of silver nitrate hexamethylenetetramine complex

    Energy Technology Data Exchange (ETDEWEB)

    Afanasiev, Pavel, E-mail: pavel.afanasiev@ircelyon.univ-lyon.fr

    2016-07-15

    Silver nitrate hexamethylenetetramine [Ag(NO{sub 3})·N{sub 4}(CH{sub 2}){sub 6}] coordination compound has been prepared via aqueous route and characterized by chemical analysis, XRD and electron microscopy. Decomposition of [Ag(NO{sub 3})·N{sub 4}(CH{sub 2}){sub 6}] under hydrogen and under inert has been studied by thermal analysis and mass spectrometry. Thermal decomposition of [Ag(NO{sub 3})·N{sub 4}(CH{sub 2}){sub 6}] proceeds in the range 200–250 °C as a self-propagating rapid redox process accompanied with the release of multiple gases. The decomposition leads to formation of sponge-like silver having hierarchical open pore system with pore size spanning from 10 µm to 10 nm. The as-obtained silver sponges exhibited favorable activity toward H{sub 2}O{sub 2} electrochemical reduction, making them potentially interesting as non-enzyme hydrogen peroxide sensors. - Graphical abstract: Thermal decomposition of silver nitrate hexamethylenetetramine coordination compound [Ag(NO{sub 3})·N{sub 4}(CH{sub 2}){sub 6}] leads to sponge like silver that possesses open porous structure and demonstrates interesting properties as an electrochemical hydrogen peroxide sensor. Display Omitted - Highlights: • [Ag(NO{sub 3})·N{sub 4}(CH{sub 2}){sub 6}] orthorhombic phase prepared and characterized. • Decomposition of [Ag(NO{sub 3})·N{sub 4}(CH{sub 2}){sub 6}] leads to metallic silver sponge with opened porosity. • Ag sponge showed promising properties as a material for hydrogen peroxide sensors.

  4. Alkyne-Azide Cycloaddition Catalyzed by Silver Chloride and “Abnormal” Silver N-Heterocyclic Carbene Complex

    Science.gov (United States)

    Ortega-Arizmendi, Aldo I.; Aldeco-Pérez, Eugenia; Cuevas-Yañez, Erick

    2013-01-01

    A library of 1,2,3-triazoles was synthesized from diverse alkynes and azides using catalytic amounts of silver chloride instead of copper compounds. In addition, a novel “abnormal” silver N-heterocyclic carbene complex was tested as catalyst in this process. The results suggest that the reaction requires only 0.5% of silver complex, affording 1,2,3-triazoles in good yields. PMID:24307866

  5. European Cyber Security Policy

    OpenAIRE

    Bendiek, Annegret

    2012-01-01

    The gradually developing European cyber security policy tries to establish minimum standards in all EU member states with regard to prevention, resilience and international cooperation. It aims to foster national security without compromising democratic principles or unduly limiting individual liberties. However, it is hard to find a balance between these goals, and the EU’s measures thus inevitably raise questions about the democratic implications of European cyber security policy. Are the i...

  6. Timetabling on European Corridors

    OpenAIRE

    Lischke, Andreas; Führer, B. (Bernhard); Garavagno, G.

    2005-01-01

    The Path Allocation Re-engineering of Timetable Networks for European Railways (PARTNER) project aims to demonstrate a new way of train path allocation and assembly along international corridors towards a faster and more coordinated railway infrastructure capacity management. PARTNER will assist two neighbour infrastructure managers to develop a common understanding of the effects of international train paths. The results of a survey of European infrastructure managers and railway underta...

  7. European Physical Society awards

    CERN Multimedia

    2004-01-01

    The winners of the 2004 Accelerator Prizes, awarded by the European Physical Society's Interdivisional Group on Accelerators (EPS-IGA), have been announced. Vladmir Shiltsev (Fermilab) and Igor Meshkov (JINR, Joint Institute of Nuclear Research, Dubna) will be presented with their awards during the 9th European Particle Accelerator Conference, EPAC'04, on 8 July 2004 in Lucerne. Both physicists will also give a talk about their work. More details on: http://epac.web.cern.ch/

  8. European Banking Union

    OpenAIRE

    Breuss, Fritz

    2013-01-01

    The ongoing Euro crisis and the worse economic development in Europe than in the USA are grounded, not the least in the delayed implementation of reforms of the banking sector. Whereas the leaks in economic governance of EMU have been fixed the banking sector is still not stabilised, even five years after Lehman Brothers. From the grand solution of a "European Banking Union" (EBU) only the first pillar, the European Bank Supervision with the single supervisory mechanism (SSM) will come into e...

  9. European DHC Research Issues

    Energy Technology Data Exchange (ETDEWEB)

    Wiltshire, Robin; Williams, Jonathan (Building Research Establishment, BRE, Bucknalls Lane, Watford (United Kingdom)); Werner, Sven (Halmstad University, School of Business and Engineering, Halmstad (Sweden))

    2008-09-15

    Euroheat and Power is now working towards a European Technology Platform for District Heating and Cooling. In response to this important European DHC research initiative, a preliminary detailed list of research issues within 18 dimensions was elaborated and communicated to more than 100 people in February 2008. After additions and comments received, an updated list of research issues was again distributed in July 2008. This paper contains the current list of suggested research issues

  10. Distinct genecological patterns in seedlings of Norway spruce and silver fir from a mountainous landscape.

    Science.gov (United States)

    Frank, Aline; Sperisen, Christoph; Howe, Glenn Thomas; Brang, Peter; Walthert, Lorenz; St Clair, John Bradley; Heiri, Caroline

    2017-01-01

    Understanding the genecology of forest trees is critical for gene conservation, for predicting the effects of climate change and climate change adaptation, and for successful reforestation. Although common genecological patterns have emerged, species-specific details are also important. Which species are most vulnerable to climate change? Which are the most important adaptive traits and environmental drivers of natural selection? Even though species have been classified as adaptive specialists vs. adaptive generalists, large-scale studies comparing different species in the same experiment are rare. We studied the genecology of Norway spruce (Picea abies) and silver fir (Abies alba), two co-occurring but ecologically distinct European conifers in Central Europe. For each species, we collected seed from more than 90 populations across Switzerland, established a seedling common-garden test, and developed genecological models that associate population variation in seedling growth and phenology to climate, soil properties, and site water balance. Population differentiation and associations between seedling traits and environmental variables were much stronger for Norway spruce than for silver fir, and stronger for seedling height growth than for bud phenology. In Norway spruce, height growth and second flushing were strongly associated with temperature and elevation, with seedlings from the lowlands being taller and more prone to second flush than seedlings from the Alps. In silver fir, height growth was more weakly associated with temperature and elevation, but also associated with water availability. Soil characteristics explained little population variation in both species. We conclude that Norway spruce has become an adaptive specialist because trade-offs between rapid juvenile growth and frost avoidance have subjected it to strong diversifying natural selection based on temperature. In contrast, because silver fir has a more conservative growth habit, it has

  11. Different mixtures of Norway spruce, silver fir, and European beech modify competitive interactions in central European mature mixed forests

    National Research Council Canada - National Science Library

    Tobin, Brian; Larocque, Guy R; Petráš, Rudolf; Bosela, Michal; Šebeň, Vladimír

    2015-01-01

    ...–spruce forests, mostly because of a lack of long-term experimental research. In the 1960s, long-term sample plots were established in the Western Carpathians to develop region-specific yield models...

  12. Deposition and Characterization of Silver Oxide from Solution of Silver, Cassava and Sugarcane Juice Effects

    OpenAIRE

    Uche E. Ekpunobi; Austine I Anozie; Onyebuchi O. OKWUKOGU; Adaora S. OGBUAGU; Valentine I. AJIWE

    2013-01-01

    Silver oxide was deposited on metallic substrates (zinc and lead) from silver solution with different additives at a pH of 5, dc current of 0.2A, 4V for 20seconds at 25°C. The additives were cassava solution and sugarcane juice. The metallic substrates served as cathode while a copper electrode serves as the anode. Compositions of the electrolytes were 50ml AgNO3, 50ml AgNO3 and 50ml of cassava solution or 50ml of sugarcane juice. Structural and textural characterizations were carried out on ...

  13. Transfer of Silver Nanoparticles through the Placenta and Breast Milk during in vivo Experiments on Rats.

    Science.gov (United States)

    Melnik, E A; Buzulukov, Yu P; Demin, V F; Demin, V A; Gmoshinski, I V; Tyshko, N V; Tutelyan, V A

    2013-07-01

    Silver nanoparticles (NPs), widely used in the manufacture of various types of consumer products and for medical applications, belong to novel types of materials that pose potential risks to human health. The potential negative effects of the influence of these NPs on reproduction are insufficiently researched. A quantitative assessment of the transfer of metallic silver nanoparticles through the placenta and breast milk was carried out during an in vivo experiment. We used 34.9 ± 14.8 nm in size silver NPs that were stabilized by low-molecularweight polyvinylpyrrolidone and labeled with the (110m)Ag radioactive isotope using thermal neutron irradiation in a nuclear reactor. [(110m)Ag]-labeled NPs preparations were administered intragastrically via a gavage needle to pregnant (20(th) day of gestation) or lactating (14-16th day of lactation) female rats at a dose of 1.69-2.21 mg/kg of body weight upon conversion into silver. The accumulation of NPs in rat fetuses and infant rats consuming their mother's breast milk was evaluated using a low-background semiconductor gamma-ray spectrometer 24 and 48 hours following labeling, respectively. In all cases, we observed a penetration of the [(110m)Ag]-labeled NPs through the placenta and ther entry into the mother's milk in amounts exceeding by 100-1,000 times the sensitivity of the utilized analytical method. The average level of accumulation of NPs in fetuses was 0.085-0.147% of the administered dose, which was comparable to the accumulation of the label in the liver, blood, and muscle carcass of adult animals and exceeded the penetration of NPs across the hematoencephalic barrier into the brain of females by a factor of 10-100. In lactating females, the total accumulation of [(110m)Ag]-labeled NPs into the milk exceeded 1.94 ± 0.29% of the administered dose over a 48 h period of lactation; not less than 25% of this amount was absorbed into the gastrointestinal tract of infant rats. Thus, this was the first time

  14. Female terrorism : a review

    NARCIS (Netherlands)

    Jacques, Karen; Taylor, Paul J.

    2009-01-01

    The sharp growth in the number of publications examining female involvement in terrorism has produced a valuable but un-integrated body of knowledge spread across many disciplines. In this paper, we bring together 54 publications on female terrorism and use qualitative and quantitative analyses to

  15. The Female Athlete Triad

    Science.gov (United States)

    Sherman, Roberta Trattner; Thompson, Ron A.

    2004-01-01

    The Female Athlete Triad is a syndrome of the interrelated components of disordered eating, amenorrhea, and osteoporosis. Sometimes inadvertently, but more often by willful dietary restriction, many female athletes do not ingest sufficient calories to adequately fuel their physical or sport activities, which can disrupt menstrual functioning,…

  16. Selective recovery of silver from waste low-temperature co-fired ceramic and valorization through silver nanoparticle synthesis.

    Science.gov (United States)

    Swain, Basudev; Shin, Dongyoon; Joo, So Yeong; Ahn, Nak Kyoon; Lee, Chan Gi; Yoon, Jin-Ho

    2017-11-01

    Considering the value of silver metal and silver nanoparticles, the waste generated during manufacturing of low temperature co-fired ceramic (LTCC) were recycled through the simple yet cost effective process by chemical-metallurgy. Followed by leaching optimization, silver was selectively recovered through precipitation. The precipitated silver chloride was valorized though silver nanoparticle synthesis by a simple one-pot greener synthesis route. Through leaching-precipitation optimization, quantitative selective recovery of silver chloride was achieved, followed by homogeneous pure silver nanoparticle about 100nm size were synthesized. The reported recycling process is a simple process, versatile, easy to implement, requires minimum facilities and no specialty chemicals, through which semiconductor manufacturing industry can treat the waste generated during manufacturing of LTCC and reutilize the valorized silver nanoparticles in manufacturing in a close loop process. Our reported process can address issues like; (i) waste disposal, as well as value-added silver recovery, (ii) brings back the material to production stream and address the circular economy, and (iii) can be part of lower the futuristic carbon economy and cradle-to-cradle technology management, simultaneously. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Influence of nano-fiber membranes on the silver ions released from hollow fibers containing silver particles

    Directory of Open Access Journals (Sweden)

    Li Huigai

    2016-01-01

    Full Text Available Polyether sulfone was dissolved into dimethylacetamide with the concentration of 20% to prepare a uniform solution for fabrication of nanofiber membranes by bubble electrospinning technique. Morphologies of the nanofiber film were carried out with a scanning electron microscope. The influence on the silver ions escaped from hollow fiber loaded with silver particles was exerted by using different release liquid. The water molecular clusters obtained from the nanofiber membranes filter can slow down the release of silver ions. However, the effect of slowing was weakened with the time increasing. In the end, the trend of change is gradually consistent with the trend of release of silver ions in the deionized water.

  18. Capillary electrophoresis coupled with inductively coupled mass spectrometry as an alternative to cloud point extraction based methods for rapid quantification of silver ions and surface coated silver nanoparticles.

    Science.gov (United States)

    Qu, Haiou; Mudalige, Thilak K; Linder, Sean W

    2016-01-15

    Speciation and accurate quantification of ionic silver and metallic silver nanoparticles are critical to investigate silver toxicity and to determine the shelf-life of products that contain nano silver under various storage conditions. We developed a rapid method for quantification of silver ions and silver nanoparticles using capillary electrophoresis (CE) interfaced with inductively-coupled plasma mass spectrometry (ICPMS). The addition of 2-mercaptopropionylglycine (tiopronin) to the background electrolyte was used to facilitate the chromatographic separation of ionic silver and maintain the oxidation state of silver. The obtained limits of detection were 0.05 μg kg(-1) of silver nanoparticles and 0.03 μg kg(-1) of ionic silver. Nanoparticles of varied sizes (10-110 nm) with different surface coating, including citrate acid, lipoic acid, polyvinylpyrrolidone and bovine serum albumin (BSA) were successfully analyzed. Particularly good recoveries (>93%) were obtained for both ionic silver and silver nanoparticle in the presence of excess amount of BSA. The method was further tested with six commercially available dietary supplements which varied in concentration and matrix components. The summed values of silver ions and silver nanoparticles correlated well with the total silver concentration determined by ICPMS after acid digestion. This method can serve as an alternative to cloud point extraction technique when the extraction efficiency for protein coated nanoparticles is low. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Female sexual dysfunction in female genital mutilation.

    Science.gov (United States)

    Elneil, Sohier

    2016-01-01

    Female genital mutilation (FGM), otherwise known as female genital cutting (FGC), is currently very topical and has become a significant global political issue. The impact of FGM on the lives of women and girls is enormous, as it often affects both their psychology and physical being. Among the complications that are often under-reported and not always acknowledged is female sexual dysfunction (FSD). FSD presents with a complex of symptoms including lack of libido, arousability and orgasm. This often occurs in tandem with chronic urogenital pain and anatomical disruption due to perineal scarring.To treat FSD in FGM each woman needs specifically directed holistic care, geared to her individual case. This may include psychological support, physiotherapy and, on occasion, reconstructive surgery. In many cases the situation is complicated by symptoms of chronic pelvic pain, which can make treatment increasingly difficult as this issue needs a defined multidisciplinary approach for its effective management in its own right. The problems suffered by women with FGM are wholly preventable, as the practice need not happen. The current global momentum to address the social, cultural, economic and medical issues of FGM is being supported by communities, governments, non-governmental agencies (NGOs) and healthcare providers. It is only by working together that the practice can be abolished and women and girls may be free from this practice and its associated consequences. © The Author(s) 2016.

  20. Habermas on European Constitution and European Identity

    Directory of Open Access Journals (Sweden)

    Éva Biró-Kaszás

    2010-12-01

    Full Text Available For the last two decades or so philosophers have been reflecting on a set of practical and political concerns in connection with the new political structural arrangements beyond the nation-state. In this article two essays by Jürgen Habermas shall be examined. An attempt shall be made to tackle Habermas’ philosophical concepts of personal and collective identity as well as the role that a constitution may play in building the post-national constellation. It has been shown that Habermas has normative answers. Firstly, according to him, the fragile balance between the legal order and the particular cultures and traditions of a community has to be protected by the constitutional state. For that reason the political culture has to be “decoupled” from the majority culture. Secondly, the democratically structured attempt to achieve shared meaning has to find the delicate balance between the context-transcending universal normative claims and the claims of particular individual and collective life. Thirdly, it is possible to expand legally mediated civil solidarity trans-nationally, across Europe – we may recognize this development as the emergence of European identity –, since the process of democratic will-formation of citizens may get loose from the structures provided by the state if both shared democratic political cultures as well as a European-wide public sphere exist. The European Constitution may have a catalytic function in materialization of these conditions. It has been shown that in his deliberations Habermas tried to find a reflective equilibrium between the normative and the empirical.

  1. Perceptions of Jewish Female Bodies through Gustav Klimt and Peter Altenberg

    National Research Council Canada - National Science Library

    Susanne Kelley

    2012-01-01

    Gustav Klimt and Peter Altenberg are two figures within Viennese fin-de-siècle cultural production whose art may reveal a perception of local Jewish culture through their different foci on the non-European female body image...

  2. Hepatic Hemangiosarcoma : An Absolute Contraindication to Liver Transplantation-The European Liver Transplant Registry Experience

    NARCIS (Netherlands)

    Orlando, Giuseppe; Adam, Rene; Mirza, Darius; Soderdahl, Goran; Porte, Robert J.; Paul, Andreas; Burroughs, Andrew K.; Seiler, Christian A.; Colledan, Michele; Graziadei, Ivo; Garcia Valdecasas, Juan-Carlos; Pruvot, Francois-Rene; Karam, Vincent; Lerut, Jan

    2013-01-01

    Background. Liver transplantation (LT) is performed for hemangiosarcoma (HAS) despite disappointing results. Methods. Retrospective study of 14 males and 8 females reported to the European Liver Transplant Registry. In view of the difficult differential diagnosis between HAS and hemangioendothelioma

  3. Antimicrobial activity of silver nanoparticles synthesized by the ...

    African Journals Online (AJOL)

    Silver nanoparticles have been widely reported in literature due to their vast industrial application in different areas. In this work, we explored a simple procedure for the biosynthesis of silver nanoparticles at room temperature from the action of Curvularia inaequalis as reduction agent. The degree of aggregation and size of ...

  4. Nanomaterial Case Study: Nanoscale Silver in Disinfectant Spray (Final Report)

    Science.gov (United States)

    EPA announced the release of the final report, Nanomaterial Case Study: Nanoscale Silver in Disinfectant Spray. This report represents a case study of engineered nanoscale silver (nano-Ag), focusing on the specific example of nano-Ag as possibly used in disinfectant spr...

  5. Green synthesis of silver nanoparticles using Arbutus andrachne ...

    African Journals Online (AJOL)

    Purpose: To synthesize silver nanoparticles (AgNPs) of Arbutus andrachne leaf water extract (LE) and ... Silver is the most important metal in the synthesis of bionanoparticles because it is an antimicrobial agent that protects against the increasing threat posed by antibiotic ... For the determination of the mean particle size.

  6. Silver recovery aqueous techniques from diverse sources: Hydrometallurgy in recycling.

    Science.gov (United States)

    Syed, S

    2016-04-01

    The demand of silver is ever increasing with the advance of the industrialized world, whereas worldwide reserves of high grade silver ores are retreating. However, there exist large stashes of low and lean grade silver ores that are yet to be exploited. The main impression of this work was to draw attention to the most advance technologies in silver recovery and recycling from various sources. The state of the art in recovery of silver from different sources by hydrometallurgical and bio-metallurgical processing and varieties of leaching, cementing, reducing agents, peeling, electro-coagulants, adsorbents, electro-dialysis, solvent extraction, ion exchange resins and bio sorbents are highlighted in this article. It is shown that the major economic driver for recycling of depleted sources is for the recovery of silver. In order to develop an nature-friendly technique for the recovery of silver from diverse sources, a critical comparison of existing technologies is analyzed for both economic viability and environmental impact was made in this amendment and silver ion toxicity is highlighted. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Laser ablation deposition measurements from silver and nickel

    DEFF Research Database (Denmark)

    Svendsen, Winnie Edith; Ellegaard, Ole; Schou, Jørgen

    1996-01-01

    The deposition rate for laser ablated metals has been studied in a standard geometry for fluences up to 20 J/cm(2). The rate for silver and nickel is a few percent of a monolayer per pulse at the laser wavelengths 532 nm and 355 nm. The rate for nickel is significantly higher than that for silver...

  8. Unexplored vegetal green synthesis of silver nanoparticles: A ...

    African Journals Online (AJOL)

    Francois Eyaane Meva

    2016-03-09

    Mar 9, 2016 ... Key words: Silver, nanoparticles, Corchorus olitorus, Ipomea batatas, X-ray diffraction. INTRODUCTION. Silver nanoparticles are receiving great attention due to their applications in different areas such as biotechnology, packaging, electronics, medicine and coatings (Solgi,. 2014). The synthesis of ...

  9. Eco-friendly synthesis of silver nanoparticles using Lactobacillus ...

    African Journals Online (AJOL)

    Silver nanoparticles have gained global popularity because of its application in crucial areas such as medical diagnosis/therapy, solar cell development, water treatment, surface coating and cosmetic production. Bacterial synthesis of silver nanoparticles is regarded as eco-friendly due to minimal waste generated while ...

  10. A Hoard of Silver Currency from Achaemenid Babylon

    DEFF Research Database (Denmark)

    Reade, Julian

    1986-01-01

    Analytical appendix by M.J. Hughes and M.R. Cowell of some 25 silver items, both sheets and coins, from the hoard, includes analysis by x-ray fluorescence and atomic absorption spectroscopy. All items are of fairly good silver, with one or two parts of copper, and substantial traces of gold and a...

  11. Electrochemical formation and reduction of silver oxides in alkaline media

    NARCIS (Netherlands)

    Droog, J.M.M.; Huisman, F.

    1980-01-01

    The anodic oxidation of silver electrodes in NaOH solution and the reduction of the silver oxides formed were studied by potential step chronoamperometry. Oxidation of Ag to Ag2O is a diffusion-controlled reaction, the diffusion control being established in the solid phase. Oxidation of Ag2O to AgO

  12. Preparation and characterization of silver nanoparticles in natural ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 35; Issue 5. Preparation and characterization of silver nanoparticles in natural polymers using laser ablation ... In this paper we have done a comparative study on efficiency of natural polymers for stabilizing silver nanoparticles (Ag-NPs) prepared by laser ablation ...

  13. Recent development in deciphering the structure of luminescent silver nanodots

    Science.gov (United States)

    Choi, Sungmoon; Yu, Junhua

    2017-05-01

    Matrix-stabilized silver clusters and stable luminescent few-atom silver clusters, referred to as silver nanodots, show notable difference in their photophysical properties. We present recent research on deciphering the nature of silver clusters and nanodots and understanding the factors that lead to variations in luminescent mechanisms. Due to their relatively simple structure, the matrix-stabilized clusters have been well studied. However, the single-stranded DNA (ssDNA)-stabilized silver nanodots that show the most diverse emission wavelengths and the best photophysical properties remain mysterious species. It is clear that their photophysical properties highly depend on their protection scaffolds. Analyses from combinations of high-performance liquid chromatography, inductively coupled plasma-atomic emission spectroscopy, electrophoresis, and mass spectrometry indicate that about 10 to 20 silver atoms form emissive complexes with ssDNA. However, it is possible that not all of the silver atoms in the complex form effective emission centers. Investigation of the nanodot structure will help us understand why luminescent silver nanodots are stable in aqueous solution and how to further improve their chemical and photophysical properties.

  14. Facile synthesis and catalytic properties of silver colloidal ...

    Indian Academy of Sciences (India)

    Administrator

    Organic thiol compounds, long-chain amines and surfactants are commonly used as capping agents to stabilize colloidal silver (Wani et al 2013). Sodium oleate, valine, xanthate and cyclodextrin have also been used to stabilize silver nanostructures. In addition, poly- mers, such as polyvinyl pyrrolidone (PVP) and polysty-.

  15. Visualizing the mobility of silver during catalytic soot oxidation

    DEFF Research Database (Denmark)

    Gardini, Diego; Christensen, Jakob M.; Damsgaard, Christian Danvad

    2016-01-01

    The catalytic activity and mobility of silver nanoparticles used as catalysts in temperature programmed oxidation of soot:silver (1:5 wt:wt) mixtures have been investigated by means of flow reactor experiments and in situ environmental transmission electron microscopy (ETEM). The carbon oxidation...

  16. Interpretation of neutron activation analysis data of ancient silver

    Energy Technology Data Exchange (ETDEWEB)

    Meyers, P; van Zelst, L; Sayre, E V

    1976-01-01

    Results from work on Sasanian silver and objects from related periods and geographic provenances are used to demonstrate that analytical data in combination with other properties can be used with reasonable success in establishing groups of objects of common geographic provenances, in providing information on the production, use, and distribution of silver metal, and on ancient metal working techniques. (LK)

  17. Dermal exposure potential from textiles that contain silver nanoparticles.

    Science.gov (United States)

    Stefaniak, Aleksandr B; Duling, Mathew G; Lawrence, Robert B; Thomas, Treye A; LeBouf, Ryan F; Wade, Eleanor E; Virji, M Abbas

    2014-01-01

    Factors that influence exposure to silver particles from the use of textiles are not well understood. The aim of this study was to evaluate the influence of product treatment and physiological factors on silver release from two textiles. Atomic and absorbance spectroscopy, electron microscopy, and dynamic light scattering (DLS) were applied to characterize the chemical and physical properties of the textiles and evaluate silver release in artificial sweat and saliva under varying physiological conditions. One textile had silver incorporated into fiber threads (masterbatch process) and the other had silver nanoparticles coated on fiber surfaces (finishing process). Several complementary and confirmatory analytical techniques (spectroscopy, microscopy, etc.) were required to properly assess silver release. Silver released into artificial sweat or saliva was primarily in ionic form. In a simulated "use" and laundering experiment, the total cumulative amount of silver ion released was greater for the finishing process textile (0·51±0·04%) than the masterbatch process textile (0·21±0·01%); Ptextile fibers was a more influential exposure factor than physiological properties of artificial sweat or saliva.

  18. Transformation of Silver Nanoparticles in Fresh, Aged, and Incinerated Biosolids

    Science.gov (United States)

    Abstract The purpose of this research was to assess the chemical transformation of silver nanoparticles (AgNPs) in aged, fresh, and incinerated biosolids in order to provide information for AgNP life cycle analyses. Silver nanoparticles were introduced to the influent of a pilot...

  19. Evolution, dissolution and reversible generation of gold and silver ...

    Indian Academy of Sciences (India)

    Unknown

    In this brief communication, we have highlighted for the first time the in situ preparation, dissolution and reversible generation of gold and silver nanoparticles from their cyano complexes by the UV-light. Here we have exhibited the preparation of gold and silver nanoparticles by UV- photoactivation method and then their ...

  20. Tuning photoluminescence of ZnS nanoparticles by silver

    Indian Academy of Sciences (India)

    Wintec

    Tuning photoluminescence of ZnS nanoparticles by silver. A MURUGADOSS. 1 and ARUN CHATTOPADHYAY. 1,2,. *. 1. Department of Chemistry and. 2. Centre for Nanotechnology, Indian Institute of Technology Guwahati,. Guwahati 781 039, India. Abstract. We report the results of investigation of the interaction of silver ...

  1. Dermal exposure potential from textiles that contain silver nanoparticles

    Science.gov (United States)

    Stefaniak, Aleksandr B; Duling, Mathew G; Lawrence, Robert B; Thomas, Treye A; LeBouf, Ryan F; Wade, Eleanor E; Abbas Virji, M

    2014-01-01

    Background: Factors that influence exposure to silver particles from the use of textiles are not well understood. Objectives: The aim of this study was to evaluate the influence of product treatment and physiological factors on silver release from two textiles. Methods: Atomic and absorbance spectroscopy, electron microscopy, and dynamic light scattering (DLS) were applied to characterize the chemical and physical properties of the textiles and evaluate silver release in artificial sweat and saliva under varying physiological conditions. One textile had silver incorporated into fiber threads (masterbatch process) and the other had silver nanoparticles coated on fiber surfaces (finishing process). Results: Several complementary and confirmatory analytical techniques (spectroscopy, microscopy, etc.) were required to properly assess silver release. Silver released into artificial sweat or saliva was primarily in ionic form. In a simulated “use” and laundering experiment, the total cumulative amount of silver ion released was greater for the finishing process textile (0.51±0.04%) than the masterbatch process textile (0.21±0.01%); P<0.01. Conclusions: We found that the process (masterbatch vs finishing) used to treat textile fibers was a more influential exposure factor than physiological properties of artificial sweat or saliva. PMID:25000110

  2. Biosynthesis of silver nanoparticles and its antibacterial activity ...

    African Journals Online (AJOL)

    In the present research work, biosynthesis of silver nanoparticles and its activity on bacterial pathogens were investigated. Silver nanoparticles were rapidly synthesized using Urospora sp. and the formation of nanoparticles was observed within 30 min. The results recorded from UV–vis spectrum, Fourier Transform Infrared ...

  3. Diffusion of silver during sintering in high permittivity COG dielectrics

    NARCIS (Netherlands)

    Mikkenie, R.; Groen, W.A.; Drift, R. van der

    2010-01-01

    To achieve cost reduction in multi-layer ceramic capacitors and actuators, which use a silver-palladium alloy as internal electrode, the trend is to use alloys with the highest silver content possible. This requires ceramic materials which must be sintered at a relative low temperature. Goal is to

  4. Biosynthesis of silver nanoparticles by Leishmania tropica | Rahi ...

    African Journals Online (AJOL)

    A novel biosynthesis route for Silver Nanoparticles (Ag-NPs) was attempted in the present study using Leishmania tropica the causative agent of cutaneous leishmaniasis in different countries, particularly in Mediterranean region in Iraq. Silver nanoparticles were successfully synthesized from AgNO3 by reduction of ...

  5. Characterization and Biocompatibility of Green Synthesized Silver Nanoparticles

    Science.gov (United States)

    There are currently ~1,000 commercially available products which contain some form of silver nanotechnology, ranging from topological creams and cosmetics, to anti-microbial socks and household cleansers. Previous studies have indicated that silver nanoparticles (Ag NPs) have a ...

  6. Effect of silver nanoparticle on the properties of poly (methyl ...

    Indian Academy of Sciences (India)

    Photopolymerization was performed in the presence of allyl methacrylate, as crosslinking agent, and various amount of silver nanoparticles (AgNPs). AgNPs were synthesized via chemical reduction of silver nitrate with t-BuONa-activated sodium hydride in tetrahydrofuran. The degree of monomer conversion (DC%) during ...

  7. Noble silver nanoparticles (AgNPs) synthesis and characterization ...

    African Journals Online (AJOL)

    Nanotechnology is rapidly growing with nanoparticles produced and utilized in a wide range of pharmaceutical and commercial products throughout the world. In this study, fig (Ficus carica) leaf extracts were used for ecofriendly extracellular synthesis of stable silver nanoparticles (AgNPs) by treating an aqueous silver ...

  8. Silver nanoparticles – a material of the future…?

    Directory of Open Access Journals (Sweden)

    Pulit-Prociak Jolanta

    2016-01-01

    Full Text Available The paper presents properties of nanomaterials and methods of their principal applications. Environmental aspects of using nanomaterials and reasons for their toxicity are also reviewed. The vast part of the paper is devoted to properties, application and market of silver nanoparticles. Their biocidal activity is clarified. However, silver nanoparticles may cause environmental pollution. Reasons for their toxicity have been also described.

  9. Otvetshajet Silver Vohu, starshii spetsialist bjuro po svjazam s obshtshestvennostju Eesti Pank / Silver Vohu

    Index Scriptorium Estoniae

    Vohu, Silver, 1980-

    2006-01-01

    17. juulil 2006 korrigeeris reitinguagentuur Standard & Poor's Eesti Vabariigi reitingu väljavaadet, muutes selle võimaliku euroalaga liitumise edasilükkumise tõttu positiivsest stabiilseks. Küsimustele vastab Eesti Panga avalike suhete büroo juhtivspetsialist Silver Vohu

  10. Silver nanowires decorated with silver nanoparticles for low-haze flexible transparent conductive films.

    Science.gov (United States)

    Menamparambath, Mini Mol; Ajmal, C Muhammed; Kim, Kwang Hee; Yang, Daejin; Roh, Jongwook; Park, Hyeon Cheol; Kwak, Chan; Choi, Jae-Young; Baik, Seunghyun

    2015-11-17

    Silver nanowires have attracted much attention for use in flexible transparent conductive films (TCFs) due to their low sheet resistance and flexibility. However, the haze was too high for replacing indium-tin-oxide in high-quality display devices. Herein, we report flexible TCFs, which were prepared using a scalable bar-coating method, with a low sheet resistance (24.1 Ω/sq at 96.4% transmittance) and a haze (1.04%) that is comparable to that of indium-tin-oxide TCFs. To decrease the haze and maintain a low sheet resistance, small diameter silver nanowires (~20 nm) were functionalized with low-temperature surface-sintering silver nanoparticles (~5 nm) using bifunctional cysteamine. The silver nanowire-nanoparticle ink stability was excellent. The sheet resistance of the TCFs was decreased by 29.5% (from 34.2 to 24.1 Ω/sq) due to the functionalization at a low curing temperature of 85 °C. The TCFs were highly flexible and maintained their stability for more than 2 months and 10,000 bending cycles after coating with a protective layer.

  11. Bioaccumulation and toxicity of silver nanoparticles and silver nitrate to the soil arthropod Folsomia candida

    NARCIS (Netherlands)

    Waalewijn-Kool, P.L.; Mallenco Forniés, R.; van Gestel, C.A.M.

    2014-01-01

    The growing use of silver nanoparticles (Ag-NP) triggered an increasing interest in their environmental fate and possible ecotoxicological impacts. To investigate the potential risk of Ag-NP to soil organisms, the springtail Folsomia candida was exposed to Ag-NP (reported diameter size 3–8 nm) and

  12. Computational probes into the basis of silver ion chromatography. II. Silver(I)-olefin complexes

    NARCIS (Netherlands)

    Kaneti, J.; Smet, de L.C.P.M.; Boom, R.M.; Zuilhof, H.; Sudhölter, E.J.R.

    2002-01-01

    Alkene complexes of silver(I) are studied by four computational methodologies: ab initio RHF, MP2, and MP4 computations, and density functional B3LYP computations, with a variety of all-electron and effective core potential basis sets. Methodological studies indicate that MP2/SBK(d) computations can

  13. European Union: Gender and politics

    Directory of Open Access Journals (Sweden)

    Žunić Natalija

    2014-01-01

    Full Text Available Political representation is the central issue in contemporary debates on the level of democracy in political institutions and processes in the European Union. Underrepresentation of particular groups in political institutions, decision-making and policy-making processes is perceived as the problem of justice, legitimacy and effectiveness in democratic societies. In this paper, the author analyzes the gender aspects of democratic decision-making processes and political representation of women in the EU member states. The social, historical and political dimension of women's efforts to obtain and promote their civil status and political rights have been the framework for developing the principle of gender equality as one of the founding EU principles. In the past hundred years, one of the most significant trends in politics has been the expansion of formal political representation of women. Yet, even though it has been more than a hundered years since women won their political rights in the 19th and the 20th century (the right to vote and the right to be voted, gender differences in political rights are still a substantial part of debate. Today, women's political representation is still inadequate and their political capacity and power have not been exercised to a sufficient extent (or proportionally through their actual representation in parliament. In March 2012, the European Commisision published a report on gender equality in different areas of social life; the Eurobarometer survey shows that women are generally underrepresented in politics. In national parliaments, only one out of four MPs is a woman. In the European Parliament, three out of ten parliamentarians are women. The statistics shows a huge discrepancy among the EU Member States in terms of women's representation in parliament (44.7% in Sweden as contrasted to 13.3% in Romania. The prevailing view in many studies is that post-industrial democracies are deficient as they have failed

  14. Recent migration developments in the European perspective

    Directory of Open Access Journals (Sweden)

    Milan Palát

    2012-01-01

    Full Text Available The aim of the paper is to evaluate the development of international migration in relationship to the recent economic situation in member countries of the European Union using quantitative methods including cluster analysis. The number of immigration in Europe has declined since the start of the global recession. The main reason was the decrease of demand in many sectors of the national economy, for instance the demand for retail and construction workers. Despite the drop in new immigration, labour markets of the EU countries were hit very severely. Unemployment rates in the most of European countries increased much more in the category of migrants than among natives. Despite the general decline in immigration in Europe during the economic crisis, the number of immigrants employed in educational sector and health care has increased. Also the number of female immigrants has been growing. The cluster analysis uses a multidimensional variable that includes GDP, unemployment, inflation rate and also net migration. We can distinguish two main clusters in 2010. The majority of highly developed West European countries are a part of the first cluster; the second cluster includes the group of post-communist countries. The latter countries form two sub-groups. A relatively independent sub-cluster is formed by some of the EU15 countries that were hit by the financial crisis the most. In general, the main two clusters illustrate that the economic division of established and new member countries of the European Union is still present.

  15. Preparation and characterization of antibacterial silver/vermiculites and silver/montmorillonites

    Science.gov (United States)

    Valášková, Marta; Hundáková, Marianna; Kutláková, Kateřina Mamulová; Seidlerová, Jana; Čapková, Pavla; Pazdziora, Erich; Matějová, Kateřina; Heřmánek, Martin; Klemm, Volker; Rafaja, David

    2010-11-01

    The reason for the preparation and characterization of the novel antibacterial silver/vermiculites (Ag/V) together with the silver/montmorillonites (Ag/M) was that the information on the vermiculite structure change and stability of Ag/V in water as well as its effect on bacteria are sporadic. The vermiculite (V), (Si 3.02Al 0.98) IV (Mg 2.27Al 0.12Fe0.283+Fe0.052+Ti 0.07) VI O 10(OH) 2 Ca 0.09Na 0.21K 0.50 from West China and montmorillonite (M), (Si 3.96Al 0.04) IV (Al 1.20Fe0.343+Mg 0.42Ti 0.02) VI O 10 (OH) 2Ca 0.15Na 0.14K 0.08 from Ivančice (Czech Republic), fraction treated with the aqueous solution of AgNO 3 for two times. The cation exchange and reduced metallic silver on M1 and V1 evoked the specific surface area (SSA) diminution, the mean particle-size diameter extension and appearance of micropores with radius (treated samples: 0.9 wt.% Ag in V1, 1.4 wt.% Ag in V2, 0.6 wt.% Ag in M1 and 1.0 wt.% Ag in M2. Vermiculite structure consisting of the hydrated interstratified phases and the mica-like phase changed to the cation-one-zero layer hydrate interstratification structure in V1 and to the random of two-one layer hydrate interstratifications in V2. Infrared and Mössbauer spectroscopy revealed no changes in the structure of the clay minerals that could be related directly to the sorption and crystallization of silver. Transmission electron microscopy showed that the silver nanoparticles size distribution was much narrower for the samples Ag/M than for Ag/V. The mean size of the Ag particles was between 40 and 50 nm. Although the Ag nanoparticles did not adhere sufficiently at the clay minerals surface and migrated moderately into water, all samples under study were approved to be effective inhibitors of the bacterial growth persisting for the whole testing period of 6 days. Silver/vermiculite was antimicrobial more efficient against Klebsiella pneumoniae and Pseudomonas aeruginosa than silver/montmorillonite.

  16. Nutritional risk of European elderly.

    Science.gov (United States)

    de Morais, C; Oliveira, B; Afonso, C; Lumbers, M; Raats, M; de Almeida, M D V

    2013-11-01

    The elderly constitute a population group with a high prevalence of non-communicable chronic diseases and high risk of malnutrition. The aim of this study was to identify factors associated to nutritional risk in free-living European elderly. The sample included 644 European citizens, free living in the community, aged 65 years or more. The sample was quota controlled for age groups (65-74, ≥75 years), gender (male/female) and living circumstances (living alone/with others). Logistic regression was performed to identify factors associated with nutritional risk. Several variables regarding socio-demographic characteristics, food choice, health status and the satisfaction with food-related life were included in the analysis. According to the recoded score of the 'Determine your nutritional health' (NSI checklist), 53% of the elderly were at nutritional risk. Nutritional risk was more likely to occur in elderly who considered that it was more important to choose foods 'easy to chew'; with lower average number of fruit and vegetables (F&V) intake episodes and lower score for general health. It was also found in non-married participants; those that did not identify changes in their appetite; and those that felt changes in health status. In this sample, the lowest nutritional risk was found for body mass index (BMI) around 18.5 kg/m(2). Country of residence, gender and age were not found to have a significant effect on nutritional risk. Attention should be drawn to the living circumstances, changes in appetite or health, the general heath perception, F&V intake, choice of foods easy to chew and having a low or high BMI.

  17. Facile Preparation of Silver Halide Nanoparticles as Visible Light Photocatalysts

    Directory of Open Access Journals (Sweden)

    Linfan Cui

    2015-07-01

    Full Text Available In this study, highly efficient silver halide (AgX-based photocatalysts were successfully fabricated using a facile and template-free direct-precipitation method. AgX nanoparticles, which included silver chloride (AgCl, silver bromide (AgBr and silver iodide (AgI, were synthesized using different potassium halides and silver acetate as reactive sources. The size distribution of the AgX nanopar‐ ticles was determined by the reaction time and ratio of the reagents, which were monitored by UV-vis spectra. The as- prepared AgX nanoparticles exhibited different photoca‐ talytic properties. This shows the differences for the photodegradation of methyl orange and Congo red dyes. In addition, the AgCl nanoparticle-based photocatalyst exhibited the best photocatalytic property among all three types of AgX nanoparticles that are discussed in this study. Therefore, it is a good candidate for removing organic pollutants.

  18. ELLIPSOMETRIC STUDY OF SEMITRANSPARENT SILVER LAYERS DEPOSITED ON GLASS

    Directory of Open Access Journals (Sweden)

    Víctor Toranzos

    2014-12-01

    Full Text Available Using ellipsometry, the film structure is characterized by optical indices n, k (visible region, 450 nm <  < 580 nm and the thickness (15 < d < 35 nm. The optical indices change with the quantity of silver deposited, obtaining effective indices of 1.0 < n < 1.8 and 1.6 < k < 2.6 to the smaller deposits that belong to a volumetric fraction between 0.35 and 0.5 of silver in the air. An effective optical thickness film decrease is observed when the silver volumetric fraction increases, and a thickness increase with close indices to solid silver when the deposited silver increases. Optical and effective medium theory indices are compared.

  19. Nanometer Sized Silver Particles Embedded Silica Particles—Spray Method

    Directory of Open Access Journals (Sweden)

    Karunagaran B

    2009-01-01

    Full Text Available Abstract Spherical shaped, nanometer to micro meter sized silica particles were prepared in a homogeneous nature by spray technique. Silver nanoparticles were produced over the surface of the silica grains in a harmonized manner. The size of silver and silica particles was effectively controlled by the precursors and catalysts. The electrostatic repulsion among the silica spheres and the electro static attraction between silica spheres and silver particles make the synchronized structure of the synthesized particles and the morphological images are revealed by transmission electron microscope. The silver ions are reduced by sodium borohydride. Infra red spectroscopy and X-ray photoelectron spectroscopy analysis confirm the formation of silver–silica composite particles. Thermal stability of the prepared particles obtained from thermal analysis ensures its higher temperature applications. The resultant silver embedded silica particles can be easily suspended in diverse solvents and would be useful for variety of applications.

  20. Compositional study of Parthian silver coins using PIXE technique

    Science.gov (United States)

    Hajivaliei, M.; Khademi Nadooshan, F.

    2012-10-01

    The study of the elemental composition of silver coins minted in the Ecbatana mint houses during the Parthian period can help to elucidate key questions such as provenance of the silver metal and the socio-economic situation of that period. Commercial activity and population growth increased the demand for silver, forcing the Parthian to look for new sources of this metal. The aim of this work is to study the chemical composition of some Parthian coins to find any relation between the mines used for extraction of silver and the actual silver coins minted at that time. Using PIXE technique, the metallic elements Ti, Fe, Cu, Zn, Ag, Au, and Pb were observed. The results show that Parthian's kings used almost two types of mines for their coins.

  1. Synthesis of Silver nanoparticles (AgNPs) with Antibacterial Activity

    Science.gov (United States)

    Campillo Gloria, E.; Ederley, Vélez; Gladis, Morales; César, Hincapié; Jaime, Osorio; Oscar, Arnache; Uribe José, Ignacio; Franklin, Jaramillo

    2017-06-01

    The synthesis of nanomaterials is currently one of the most active in nanoscience branches; especially those help improve the human quality life. Silver nanoparticles (AgNPs) are an example of this as it is known to have inhibitory and bactericidal effects. In this work, we report the synthesis of silver nanoparticles by chemical reduction method of silver nitrate (AgNO3) from aqueous solution, using a mix of polivinyl pyrrolidone (PVP) - Aloe Vera as reducing agent and for stabilization and control of particle size. Silver nanoparticles obtained were characterized by Scanning Electron Microscopy (SEM), UV-visible spectroscopy and measurements using Zetasizer Nano ZS were applied to size estimation. The existence of surface plasmon resonance peak at λmax ~ 420 nm is evidence of silver nanoparticles formation. It was possible to standardize an appropriate protocol for the evaluation of bactericidal activity of the nanoparticles, for mesophilic microorganisms. Bactericidal activity above 90% against these kinds of bacteria was demonstrated.

  2. Antimicrobial Bacterial Cellulose-Silver Nanoparticles Composite Membranes

    Directory of Open Access Journals (Sweden)

    Hernane S. Barud

    2011-01-01

    Full Text Available Antimicrobial bacterial cellulose-silver nanoparticles composite membranes have been obtained by “in situ” preparation of Ag nanoparticles from hydrolytic decomposition of silver nitrate solution using triethanolamine as reducing and complexing agent. The formation of silver nanoparticles was evidenced by the X-ray diffraction, scanning electron microscopy (SEM, transmission electron microscopy (TEM, and absorption in the UV-Visible (350 nm to 600 nm. Thermal and mechanical properties together with swelling behavior for water were considered. TEA concentration was observed to be important in order to obtain only Ag particles and not a mixture of silver oxides. It was also observed to control particle size and amount of silver contents in bacterial cellulose. The composite membranes exhibited strong antimicrobial activity against Gram-negative and Gram-positive bacteria.

  3. Sonochemical synthesis of silver nanoparticles using starch: a comparison.

    Science.gov (United States)

    Kumar, Brajesh; Smita, Kumari; Cumbal, Luis; Debut, Alexis; Pathak, Ravinandan Nath

    2014-01-01

    A novel approach was applied to synthesize silver nanoparticles using starch under sonication. Colloidal silver nanoparticles solution exhibited an increase of absorption from 420 to 440 nm with increase starch quantity. Transmission electron microscopy followed by selected area electron diffraction pattern analysis indicated the formation of spherical, polydispersed, amorphous, silver nanoparticles of diameter ranging from 23 to 97 nm with mean particle size of 45.6 nm. Selected area electron diffraction (SAED) confirmed partial crystalline and amorphous nature of silver nanoparticles. Silver nanoparticles synthesized in this manner can be used for synthesis of 2-aryl substituted benzimidazoles which have numerous biomedical applications. The optimized reaction conditions include 10 ml of 1 mM AgNO3, 25 mg starch, 11 pH range, and sonication for 20 min at room temperature.

  4. Biological synthesis of silver nanoparticles by using Viola serpens extract

    Directory of Open Access Journals (Sweden)

    Anu Kumar

    2016-03-01

    Full Text Available Objective: To formulate a biological approach for the biological synthesis of silver nanoparticles using aqueous extracts of leaves of Viola serpens which is considered as a ecofriendly method as it does not include any harmful chemicals. Methods: The synthesized silver nanoparticles were characterized by using UV-vis spectroscopy analysis, scanning electron microscopy analysis and X-ray diffraction analysis. Results: Scanning electron microscopy analysis study revealed that synthesized silver nanoparticles were of an average size of 80–90 nm. Crystalline nature of synthesized silver nanoparticles was confirmed by X-ray diffraction analysis. Conclusions: The leaves of Viola serpens can be a potent source for the biological synthesis of silver nanoparticles. The outcome of the study can lead to the development of a novel drug for biomedical field.

  5. Photo response of silver-TiO2 film.

    Science.gov (United States)

    Viernes, M A J; Mahinay, C L S; Villamayor, M M S; Ramos, H J

    2014-02-01

    Silver and TiO2 films were deposited on glass substrates via the plasma sputter type negative ion source and a compact planar magnetron, respectively. A silver target was biased and is sputtered by argon plasma for 30 min. TiO2 was deposited by sputtering a titanium disk and introducing oxygen in a 1:13 ratio with argon plasma for 2 h. The resulting composite films (silver on TiO2 and TiO2 on silver) were analyzed by its transmissivity in the UV-VIS region showing increased optical absorbance. The synthesized films were used in the photocatalytic degradation of methylene blue showing an increase in photocatalytic degradation when only TiO2 is used. The introduction of silver with TiO2 inhibited the effective photocatalytic degradation of methylene blue.

  6. Female pattern baldness

    Science.gov (United States)

    Alopecia in women; Baldness - female; Hair loss in women; Androgenetic alopecia in women; Hereditary balding or thinning in women ... in the skin called a follicle. In general, baldness occurs when the hair follicle shrinks over time, ...

  7. Female Athlete Triad

    Science.gov (United States)

    ... be due to an eating disorder, such as anorexia.Girls and women may be at risk for the female athlete triad if they:are a competitive athleteplay sports that require them to maintain a certain weight ...

  8. Inbreeding Promotes Female Promiscuity

    National Research Council Canada - National Science Library

    Łukasz Michalczyk; Anna L. Millard; Oliver Y. Martin; Alyson J. Lumley; Brent C. Emerson; Tracey Chapman; Matthew J. G. Gage

    2011-01-01

    .... Using the red flour beetle, Tribolium castaneum, we identify major fitness benefits of polyandry to females under inbreeding, when the risks of fertilization by incompatible male haplotypes are especially high...

  9. Transnational European Television Drama

    DEFF Research Database (Denmark)

    Bondebjerg, Ib; Redvall, Eva Novrup; Helles, Rasmus

    This book deals with the role of television drama in Europe as enabler of transnational, cultural encounters for audiences and the creative community. It demonstrates that the diversity of national cultures is a challenge for European TV drama but also a potential richness and source of creative...... variation. Based on data on the production, distribution and reception of recent TV drama from several European countries, the book presents a new picture of the transnational European television culture. The authors analyse main tendencies in television policy and challenges for national broadcasters...... coming from new global streaming services. Comparing cases of historical, contemporary and crime drama from several countries, this study shows the importance of creative co-production and transnational mediated cultural encounters between national cultures of Europe....

  10. The Europeanization of Eurosceptics?

    DEFF Research Database (Denmark)

    Dutceac Segesten, Anamaria; Bossetta Jr, Michael Joseph

    with the case of Sweden. Sweden is a good example because it has a high density of internet use, a politically active population as reflected in voter turnout and many politicians and political parties with a web presence. The main research questions of the paper are: Which actors are involved in the Swedish...... of a Europeanized network of anti-European voices for European integration and democracy. We plan to operationalize our research question through the use of webcrawling (i.e. Issue Crawler) and social media analytic softwares (Twitonomy and Bluenod). Using these softwares we will be able to discern whether...... or not non-Swedish Twitter users are participating in and/or affecting the Swedish Eurosceptic dialogue on social media....

  11. European Analytical Column

    DEFF Research Database (Denmark)

    Karlberg, B.; Grasserbauer, M.; Andersen, Jens Enevold Thaulov

    2009-01-01

    The European Analytical Column has once more invited a guest columnist to give his views on various matters related to analytical chemistry in Europe. This year, we have invited Professor Manfred Grasserbauer of the Vienna University of Technology to present some of the current challenges...... for European analytical chemistry. During the period 2002–07, Professor Grasserbauer was Director of the Institute for Environment and Sustainability, Joint Research Centre of the European Commission (EC), Ispra, Italy. There is no doubt that many challenges exist at the present time for all of us representing...... a major branch of chemistry, namely analytical chemistry. The global financial crisis is affecting all branches of chemistry, but analytical chemistry, in particular, since our discipline by tradition has many close links to industry. We have already noticed decreased industrial commitment with respect...

  12. European Universe Awareness

    Science.gov (United States)

    Russo, P.; Miley, G.; Westra van Holthe, F.; Schrier, W.; Reed, S.

    2011-10-01

    The European Universe Awareness (EU-UNAWE) programme uses the beauty and grandeur of the cosmos to encourage young children, particularly those from underprivileged backgrounds, to develop an interest in science and technology and to foster a sense of global citizenship. EU-UNAWE is already active in 40 countries and comprises a global network of almost 500 astronomers, teachers and other educators. The programme was recently awarded a grant of 1.9 million euros by the European Union so that it can be further developed in five European countries and South Africa. The grant will be used to organise teacher training workshops and to develop educational materials, such as an astronomy news service for children and games. During this presentation we will outline some of the biggest achievements of EU-UNAWE to date and discuss future plans for the programme.

  13. Oxygen isotope exchange with quartz during pyrolysis of silver sulfate and silver nitrate.

    Science.gov (United States)

    Schauer, Andrew J; Kunasek, Shelley A; Sofen, Eric D; Erbland, Joseph; Savarino, Joel; Johnson, Ben W; Amos, Helen M; Shaheen, Robina; Abaunza, Mariana; Jackson, Terri L; Thiemens, Mark H; Alexander, Becky

    2012-09-30

    Triple oxygen isotopes of sulfate and nitrate are useful metrics for the chemistry of their formation. Existing measurement methods, however, do not account for oxygen atom exchange with quartz during the thermal decomposition of sulfate. We present evidence for oxygen atom exchange, a simple modification to prevent exchange, and a correction for previous measurements. Silver sulfates and silver nitrates with excess (17)O were thermally decomposed in quartz and gold (for sulfate) and quartz and silver (for nitrate) sample containers to O(2) and byproducts in a modified Temperature Conversion/Elemental Analyzer (TC/EA). Helium carries O(2) through purification for isotope-ratio analysis of the three isotopes of oxygen in a Finnigan MAT253 isotope ratio mass spectrometer. The Δ(17)O results show clear oxygen atom exchange from non-zero (17)O-excess reference materials to zero (17)O-excess quartz cup sample containers. Quartz sample containers lower the Δ(17)O values of designer sulfate reference materials and USGS35 nitrate by 15% relative to gold or silver sample containers for quantities of 2-10 µmol O(2). Previous Δ(17)O measurements of sulfate that rely on pyrolysis in a quartz cup have been affected by oxygen exchange. These previous results can be corrected using a simple linear equation (Δ(17)O(gold) = Δ(17)O(quartz) * 1.14 + 0.06). Future pyrolysis of silver sulfate should be conducted in gold capsules or corrected to data obtained from gold capsules to avoid obtaining oxygen isotope exchange-affected data. Copyright © 2012 John Wiley & Sons, Ltd.

  14. The Gender Gap in European Business Schools

    DEFF Research Database (Denmark)

    Roseberry, Lynn; Remke, Robyn; Klæsson, Johan

    "The Gender Gap in European Business Schools: A Leadership Perspective" is a research project initiated and funded by EFMD, EQUAL, and the business schools represented on the project’s Steering Committee with following motivations for the study: Numerous studies by policy makers and academics have...... (the highest positions in the academic hierarchy) in HEIs in the vast majority of EU member states. In thirteen EU countries, women represented less than 20% of grade A academic staff. Business schools are no exception to this pattern. The average proportion of all full-time female faculty – not just...... senior professors – employed by the top 85 business schools on the Financial Times 2015 European Business School Rankings is 33%. It is even less than that (23.3%) at the top 10 business schools on the list....

  15. The European Identity

    Directory of Open Access Journals (Sweden)

    Alberto Martinelli

    2017-09-01

    Full Text Available European identity is not only a scientifically interesting question, but also a politically important issue: in fact, sixty years after the signing of the Treaty of Rome, the European Union finds itself for the first time facing risks that threaten its own existence. The European Union is a limited and incomplete project because Europe’s economic integration has not been accompanied by a genuine supranational political union and greater cultural integration. The deficit of democratic representation and cultural integration is due to the fact that the community process is based only on economic rationality and not on a feeling of common belonging. In the current situation in which the Union faces difficult challenges which threaten to undermine the future, it necessary to affirm the policy of interests with a policy of identity. In this essay, we will first concentrate on the concept of identity – that is on the nucleus of values and common institutions –; then we will discuss how the European identity has changed over time (also in relation to national identities and what are the mechanisms that may favour its taking root in the current situation. The European project of political unification needs to be re-emphasized, finding the way to a European collective identity, not contrasted with but alongside the different national identities, referring to loyalty and shared commitment to a whole collection of cultural values: fundamental human rights, civil liberties, democratic political institutions, rule of law, freedom of movement of people, goods and capital, social justice and non-violent resolution of conflicts.

  16. Mechanism of acute silver toxicity in marine invertebrates.

    Science.gov (United States)

    Bianchini, Adalto; Playle, Richard C; Wood, Chris M; Walsh, Patrick J

    2005-03-25

    In freshwater crustaceans and in both freshwater and marine fish, the key mechanism of acute silver toxicity involves ionoregulatory impairment. An inhibition of the Na+ ,K+-ATPase located at the basolateral membrane of the gill epithelium seems to be the key site for silver toxicity. However, studies to determine if the same mechanism of toxicity is occurring in marine invertebrates, which also are ionoregulators, had not been done. Thus, the present study was carried out to determine acute silver effects on hemolymph osmo- and ionoregulation in three marine invertebrates: the shrimp Penaeus duorarum, the sea hare Aplysia californica, and the sea urchin Diadema antillarum. Animals were exposed to silver (1 or 10 microg/L), as silver nitrate, in seawater for 48 h. Results show that acute silver exposure did not affect hemolymph osmolality or ion concentration (Na+, Cl-, K+, Ca2+ and Mg2+) in the three species studied. However, silver induced significant changes in the water content in shrimp gill and sea hare gill and hepatopancreas. Silver also caused significant changes in Na+ ,K+-ATPase activity and in both total and intracellular ion (Cl-, Na+, K+, Mg2+, and Ca2+) concentrations in different tissues of the three species studied. Overall, these results show that the key mechanism of acute silver toxicity in marine invertebrates is not associated with an osmotic or ionoregulatory impairment at the hemolymph level, as observed in freshwater fish and crustaceans and in seawater fish. However, they indicate that acute waterborne silver induces significant changes in Na+ ,K(+)-ATPase activity and probably affects other mechanisms involved in water and ion transport at the cell membrane level, inducing impairments in water and ion regulation at the cellular level in different tissues of marine invertebrates. These results indicate the need to consider other "toxic sites" than gills in any future extension of the biotic ligand model (BLM) for seawater.

  17. Green chemical synthesis of silver nanomaterials with maltodextrin.

    Energy Technology Data Exchange (ETDEWEB)

    Tallant, David Robert; Lu, Ping; Lambert, Timothy N.; Bell, Nelson Simmons

    2010-11-01

    Silver nanomaterials have significant application resulting from their optical properties related to surface enhanced Raman spectroscopy, high electrical conductivity, and anti-microbial impact. A 'green chemistry' synthetic approach for silver nanomaterials minimizes the environmental impact of silver synthesis, as well as lowers the toxicity of the reactive agents. Biopolymers have long been used for stabilization of silver nanomaterials during synthesis, and include gum Arabic, heparin, and common starch. Maltodextrin is a processed derivative of starch with lower molecular weight and an increase in the number of reactive reducing aldehyde groups, and serves as a suitable single reactant for the formation of metallic silver. Silver nanomaterials can be formed under either a thermal route at neutral pH in water or by reaction at room temperature under more alkaline conditions. Deposited silver materials are formed on substrates from near neutral pH solutions at low temperatures near 50 C. Experimental conditions based on material concentrations, pH and reaction time are investigated for development of deposited films. Deposit morphology and optical properties are characterized using SEM and UV-vis techniques. Silver nanoparticles are generated under alkaline conditions by a dissolution-reduction method from precipitated silver (II) oxide. Synthesis conditions were explored for the rapid development of stable silver nanoparticle dispersions. UV-vis absorption spectra, powder X-ray diffraction (PXRD), dynamic light scattering (DLS), and transmission electron microscopy (TEM) techniques were used to characterize the nanoparticle formation kinetics and the influence of reaction conditions. The adsorbed content of the maltodextrin was characterized using thermogravimetric analysis (TGA).

  18. Fabrication, Conductive Properties and Photocatalytic Application of Silver Nanorods

    Science.gov (United States)

    Chen, Yi-Hsun; Liu, Pai-Chung; Lin, C. B.

    2017-07-01

    This study proposes a process for fabricating silver nanorods used in conductive circuits and photocatalytic applications. In this process, UV-irradiated silver chloride nanoparticles are added to ethylene glycol solution containing polyvinyl pyrrolidone (PVP) and silver nitrate at 120 °C. With the seed crystal synthesis method, this process yielded a solution containing silver nanowires with an aspect ratio (AR) of approximately 1055 after 12 h. Aluminum foam was then placed in this solution, and the solution was stirred using a magnetic stirrer at 400 rpm. After 4 days, this process yielded a solution of silver nanorods with an AR of approximately 130. After completely washing away any PVP on the surface of the silver nanorods, a conductive ethanol ink containing 25 wt.% silver nanorods was prepared, and a conductive layer approximately 3 μm thick was applied on a glass slide. Measurements obtained using a four-point probe indicated that this layer had a sheet resistance of approximately 0.012 Ω/sq. Furthermore, a conductive ethanol ink containing 26 wt.% silver nanorods was used in a pen to draw conductive circuits on Bristol board and matte paper; the resulting sheet resistances were 132 and 0.018 Ω/sq, respectively. Finally, a visible-light-responsive photocatalyst consisting of silver nanorods dispersed over the Ag@AgCl film (Ag@AgCl/Ag nanorods; AR = 25) was synthesized through heterogeneous precipitation. The photocatalytic activity of the Ag@AgCl film can be further improved by the addition of silver nanorods.

  19. Gender Earnings Gap among Young European Higher Education Graduates

    Science.gov (United States)

    Garcia-Aracil, Adela

    2007-01-01

    This paper examines the composition of the gender earnings gap among young European higher education graduates, with a particular focus on competencies controlling for individual background and job characteristics. The results show that much of the female worker's earnings advantage can be explained by job characteristics. With respect to the…

  20. Educational inequalities in tuberculosis mortality in sixteen European populations

    NARCIS (Netherlands)

    J.L. Álvarez Morán (Jose Luis); A.E. Kunst (Anton); M. Leinsalu (Mall); M. Bopp (Matthias); B.H. Strand; G. Menvielle (Gwenn); O. Lundberg; P. Martikainen (Pekka); P. Deboosere (Patrick); R. Kalediene; B. Artnik (Barbara); J.P. Mackenbach (Johan); J.H. Richardus (Jan Hendrik)

    2011-01-01

    textabstractOBJECTIVE: To describe the magnitude of socioe conomic inequalities in tuberculosis (TB) mortality by level of education in male, female, urban and rural populations in several European countries. DESIGN: Data were obtained from the Eurothine Project, covering 16 populations between 1990

  1. The oxidative dehydrogenation of methanol to formaldehyde over silver catalysts in relation to the oxygen-silver interaction

    NARCIS (Netherlands)

    Lefferts, Leonardus; van Ommen, J.G.; Ross, J.R.H.

    1986-01-01

    The properties of silver in the oxidative dehydrogenation of methanol were studied in a flow reactor under near industrial conditions. The influences of temperature, concentration of both reactants, gas velocity, space velocity, the form of the silver catalyst and surface composition of the catalyst

  2. The distribution of silver specimens from the Kongsberg Silver Mines, Norway, 17th and 18th centuries

    NARCIS (Netherlands)

    Berg, B.I.; Nordrum, F.S.

    2004-01-01

    Specimens of native silver from the Kongsberg mines in Norway are world famous and have been distributed through sales and gifts during the whole period of mining from 1623 to 1958. Names of customers, the number of sold specimens and their silver content are documented in accounts which are

  3. Online Female Escort Advertisements

    Directory of Open Access Journals (Sweden)

    James D. Griffith

    2016-05-01

    Full Text Available Female escorts represent an occupational group that charges a fee for sex, which can be regarded as an extreme form of short-term mating. The present study examined if the fees charged by escorts are related to traits typically associated with female short-term mate value. A total of 2,925 advertisements for female escorts offering sexual services in the United States were examined, as a customized software program was used to download all the advertisements from an online escort directory. The advertisement content was coded, and relationships between advertised physical characteristics and the hourly rate charged by female escorts were examined. The analyses showed that higher fees were associated with female escorts who advertised a waist-to-hip ratio near 0.7, lower weight and body mass index, younger age, and photographic displays of breast and buttocks nudity. The findings provide evidence that evolutionarily relevant traits associated with female short-term mate value are systematically related to fees charged for sexual services.

  4. European Gas Dependency

    OpenAIRE

    Antonsen, Iben; Bieber, Martin; Gandrup, Tobias; Lehmann, Tina; Weinberger, Ashley

    2008-01-01

    The focal point of the project is, as it is implied in the title, European gas dependency, to be more specific; the dependency of Russian gas. We chose Russia, because the EU's import of gas is mainly supplied by Russia. We present background information and knowledge to describe why the case is of relevance and that a situation of dependency exists. We solely look at the dependency from the European Union's point of view, taking point of departure in the Green Paper. The Green Paper is a pap...

  5. European Values and Globalization

    Directory of Open Access Journals (Sweden)

    Heinz Theisen

    2011-03-01

    Full Text Available Good Governance, Social Market Economy, Culture and Education are the decisive elements for Human Development. We need a third way between the extremes of the Utopian Global Free Market and a new nationalism. A Social Market Economy and the European Model of a Union could be such third way. For a new Social Market Economy we need a renaissance of the European dialectics between culture and society, idealism and materialism, religion and enlightenment, solidarity and profitability. The balancing of those poles is deeply rooted in our best traditions. 

  6. Energy loss of silver ions in gadolinium

    Energy Technology Data Exchange (ETDEWEB)

    Ribas, R.V.; Medina, N.H.; Rao, M.N.; Cybulska, E.W.; Seale, W.A. (Laboratorio Pelletron, Departamento de Fisica Nuclear, Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo (Brazil))

    1995-03-01

    The energy loss of silver ions in metallic gadolinium foil at low velocities (2.7--4.3)[ital v][sub 0], where [ital v][sub 0] is the Bohr velocity, was measured with the Doppler shift technique. The results are about 20% smaller than the predictions of a semiempirical formulation [J. F. Ziegler, J. P. Biersack, and U. L. Littmark, in [ital The] [ital Stopping] [ital and] [ital Ranges] [ital of] [ital Ions] [ital in] [ital Solids], edited by J. F. Ziegler (Pergamon, New York, 1985), Vol. 1] for the electronic stopping power.

  7. Graphene-protected copper and silver plasmonics

    DEFF Research Database (Denmark)

    Kravets, V. G.; Jalil, R.; Kim, Y. J.

    2014-01-01

    suitable for plasmonic applications. To this end, there has been a continuous search for alternative plasmonic materials that are also compatible with complementary metal oxide semiconductor technology. Here we show that copper and silver protected by graphene are viable candidates. Copper films covered...... with one to a few graphene layers show excellent plasmonic characteristics. They can be used to fabricate plasmonic devices and survive for at least a year, even in wet and corroding conditions. As a proof of concept, we use the graphene-protected copper to demonstrate dielectric loaded plasmonic...... waveguides and test sensitivity of surface plasmon resonances. Our results are likely to initiate wide use of graphene-protected plasmonics....

  8. Uptake of silver from metallic silver surfaces induces cell death and a pro-inflammatory response in cultured J774 macrophages.

    Science.gov (United States)

    Locht, Linda J; Smidt, Kamille; Rungby, Jørgen; Stoltenberg, Meredin; Larsen, Agnete

    2011-06-01

    In clinical medicine metallic silver is used as anti-bacterial coating on various catheters, bandages and prostheses. By means of dissolucytosis, i.e. extracellular macrophage-mediated bio-liberation of metal ions, silver ions are continuously liberated from silver surfaces starting within minutes of exposure. The present study investigates how bio-liberation and subsequent cellular uptake of silver ions affects cell viability and cell signalling within the first 3-24 hours of exposure when J774 macrophages are grown directly on a silver surface. Autometallography (AMG) was applied to demonstrate cytoplasmatic silver uptake and localisation after 1, 3, 12 and 24 hours of exposure to metallic silver. From 12 hours onwards the cells were completely filled with silver enhanced silver-sulphur nanocrystals (AMG-silver grains). At the ultrastructural level, the silver accumulations were located to lysosome-like structures. An immunoassay cell death kit found silver-induced apoptosis after 12 and 24 hours of exposure. Necrosis was seen at the same times. Judged by mRNA analysis silver exposure statistically significantly induces TNF-α and m-CSF gene expression, especially at 3 hours. Furthermore, anti-inflammatory IL-10 transcription is reduced by silver uptake and 24 hours of silver exposure induces massive iNOS-2 gene expression. At the same time silver exposure increases the gene expression of metallothionein (MT-I/MT-II), a cystein-rich protein known for its role in detoxifying heavy metals. Our data suggest that silver ions liberated from metallic silver surfaces accumulate in lysosomes, reduce macrophage viability by apoptosis and necrosis and induce a pro-inflammatory response.

  9. Female genital cutting.

    Science.gov (United States)

    Perron, Liette; Senikas, Vyta; Burnett, Margaret; Davis, Victoria

    2013-11-01

    To strengthen the national framework for care of adolescents and women affected by female genital cutting (FGC) in Canada by providing health care professionals with: (1) information intended to strengthen their knowledge and understanding of the practice; (2) directions with regard to the legal issues related to the practice; (3) clinical guidelines for the management of obstetric and gynaecological care, including FGC related complications; and (4) guidance on the provision of culturally competent care to adolescents and women with FGC. Published literature was retrieved through searches of PubMed, CINAHL, and The Cochrane Library in September 2010 using appropriate controlled vocabulary (e.g., Circumcision, Female) and keywords (e.g., female genital mutilation, clitoridectomy, infibulation). We also searched Social Science Abstracts, Sociological Abstracts, Gender Studies Database, and ProQuest Dissertations and Theses in 2010 and 2011. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to December 2011. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). Summary Statements 1. Female genital cutting is internationally recognized as a harmful practice and a violation of girls' and women's rights to life, physical integrity, and health. (II-3) 2. The immediate and long-term health risks and complications of female genital cutting can be serious and life threatening. (II-3) 3. Female genital cutting continues to be practised in many countries, particularly in sub-Saharan Africa, Egypt, and Sudan. (II-3) 4. Global migration

  10. Recovery of silver from used X-ray film using alkaline protease from ...

    African Journals Online (AJOL)

    Silver is an important industrial metal used in several areas such as photographic and x-ray films, jewelries, silver wares and electronic objects. Silver is used for photographic film/x-ray film because of its matchless quality as a light-sensitive material for making a photographic image. Silver is not destroyed in the ...

  11. 77 FR 61649 - Order of Suspension of Trading; In the Matter of Liberty Silver Corp.

    Science.gov (United States)

    2012-10-10

    ... COMMISSION Order of Suspension of Trading; In the Matter of Liberty Silver Corp. October 5, 2012. It appears... concerning the securities of Liberty ] Silver Corp. (``Liberty Silver'') because of questions concerning publicly available information about Liberty Silver, the control of its stock, its market price, and...

  12. Stable silver/biopolymer hybrid plasmonic nanostructures for high performance surface enhanced raman scattering (SERS)

    Science.gov (United States)

    Silver/biopolymer nanoparticles were prepared by adding 100 mg silver nitrate to 2% polyvinyl alcohol solution and reduced the silver nitrate into silver ion using 2 % trisodium citrate for high performance Surface Enhanced Raman Scattering (SERS) substrates. Optical properties of nanoparticle were ...

  13. The potential/pH diagram of silver in aqueous ammonium salt solution

    NARCIS (Netherlands)

    Sluyters, J.H.; Wijnen, M.D.; Hul, H.J. van den

    1961-01-01

    The potential/pH diagram of silver in aqueous ammonium salt solution at 25°C has been calculated and verified experimentally. Calculations were carried out on the basis of the standard potential of the silver/silver-ion couple, the dissociation constants of the silver mono- and di-ammonia

  14. The Effect of Hydrothermal Treatment on Silver Nanoparticles Stabilized by Chitosan and Its Possible Application to Produce Mesoporous Silver Powder

    Directory of Open Access Journals (Sweden)

    Dang Viet Quang

    2013-01-01

    Full Text Available Aggregation state of silver nanoparticles dispersed in an aqueous solution greatly varies with storage and treatment conditions. In this study, silver nanoparticles synthesized in chitosan solution by a chemical reduction method were hydrothermally treated at different temperatures. The variation in the aggregation state of silver nanoparticles in the solution was observed by UV-Vis spectroscopy and field emission transmission electron microscopy. Results indicated that a phase transition occurred while silver nanoparticles were hydrothermally treated for 5 h at 100 and 120∘C; however, they aggregated and completely precipitated at 150∘C. Mesoporous silver powder obtained by hydrothermal treatment at 150∘C was characterized by using X-ray diffraction technique, BET analyzer, and scanning electron spectroscope.

  15. In situ reduction of antibacterial silver ions to metallic silver nanoparticles on bioactive glasses functionalized with polyphenols

    Science.gov (United States)

    Ferraris, S.; Miola, M.; Cochis, A.; Azzimonti, B.; Rimondini, L.; Prenesti, E.; Vernè, E.

    2017-02-01

    The realization of surfaces with antibacterial properties due to silver nanoparticles loaded through a green approach is a promising research challenge of the biomaterial field. In this research work, two bioactive glasses have been doubly surface functionalized with polyphenols (gallic acid or natural polyphenols extracted from red grape skins and green tea leaves) and silver nanoparticles deposited by in situ reduction from a silver nitrate aqueous solution. The presence of biomolecules - showing reducing ability to directly obtain in situ metallic silver - and silver nanoparticles was investigated by means of UV-vis spectroscopy, X-Ray Photoelectron Spectroscopy (XPS) and Field Emission Scanning Electron Microscopy (FESEM). The antibacterial activity of the modified surfaces was tested against a multidrug resistant Staphylococcus aureus bacterial strain.

  16. Gold and silver health plans: accommodating demand heterogeneity in managed competition.

    Science.gov (United States)

    Glazer, Jacob; McGuire, Thomas G

    2011-09-01

    New regulation of health insurance markets creates multiple levels of health plans, with designations like "Gold" and "Silver." The underlying rationale for the heavy-metal approach to insurance regulation is that heterogeneity in demand for health care is not only due to health status (sick demand more than the healthy) but also to other, "taste" related factors (rich demand more than the poor). This paper models managed competition with demand heterogeneity to consider plan payment and enrollee premium policies in relation to efficiency (net consumer benefit) and fairness (the European concept of "solidarity"). Specifically, this paper studies how to implement a "Silver" and "Gold" health plan efficiently and fairly in a managed competition context. We show that there are sharp tradeoffs between efficiency and fairness. When health plans cannot or may not (because of regulation) base premiums on any factors affecting demand, enrollees do not choose the efficient plan. When taste (e.g., income) can be used as a basis of payment, a simple tax can achieve both efficiency and fairness. When only health status (and not taste) can be used as a basis of payment, health status-based taxes and subsidies are required and efficiency can only be achieved with a modified version of fairness we refer to as "weak solidarity." An overriding conclusion is that the regulation of premiums for both the basic and the higher level plans is necessary for efficiency. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Silver ion-mediated killing of a food pathogen: Melting curve analysis data of silver resistance genes and growth curve data

    Directory of Open Access Journals (Sweden)

    Kuppan Gokulan

    2017-04-01

    Full Text Available Limited antibacterial activity of silver ions leached from silver-impregnated food contact materials could be due to: 1 the presence of silver resistance genes in tested bacteria; or 2 lack of susceptibility to silver ion-mediated killing in the bacterial strain (K. Williams, L. Valencia, K. Gokulan, R. Trbojevich, S. Khare, 2016 [1]. This study contains data to address the specificity of silver resistance genes in Salmonella Typhimurium during the real time PCR using melting curve analysis and an assessment of the minimum inhibitory concentration of silver ions for Salmonella.

  18. Bacterial inhibiting surfaces caused by the effects of silver release and/or electrical field

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Hilbert, Lisbeth Rischel; Schroll, Casper

    2008-01-01

    In this study, silver-palladium surfaces and silver-bearing stainless steels were designed and investigated focusing on electrochemical principles to form inhibiting effects on planktonic and/or biofilm bacteria in water systems. Silver-resistant Escherichia coli and silver-sensitive E. coli were...... silver ions release can occur from their Surfaces. For silver-bearing stainless steels, the inhibiting effect can only be explained by high local silver ions release. and can be limited or deactivated dependent on the specific environment. (c) 2008 Elsevier Ltd. All rights reserved....

  19. Green preparation and spectroscopic characterization of plasmonic silver nanoparticles using fruits as reducing agents

    DEFF Research Database (Denmark)

    Hyllested, Jes Ærøe; Espina Palanco, Marta; Hagen, Nicolai

    2015-01-01

    Chemicals typically available in plants have the capability to reduce silver and gold salts and to create silver and gold nanoparticles. We report the preparation of silver nanoparticles with sizes between 10 and 300 nm from silver nitrate using fruit extract collected from pineapples and oranges...... as reducing agents. The evolvement of a characteristic surface plasmon extinction spectrum in the range of 420 nm to 480 nm indicates the formation of silver nanoparticles after mixing silver nitrate solution and fruit extract. Shifts in plasmon peaks over time indicate the growth of nanoparticles. Electron...... absorption correlates with the decrease of absorption band in the UV. This confirms the evolution of silver nanoparticles from silver clusters. The presence of various silver clusters on the surface of the “green” plasmonic silver nanoparticles is also supported by a strong multi-color luminesce signal...

  20. Causality in Europeanization Research

    DEFF Research Database (Denmark)

    Lynggaard, Kennet

    2012-01-01

    to develop discursive institutional analytical frameworks and something that comes close to the formulation of hypothesis on the effects of European Union (EU) policies and institutions on domestic change. Even if these efforts so far do not necessarily amount to substantive theories or claims of causality...