Validating the use of embryonic fish otoliths as recorders of sublethal exposure to copper in estuarine sediments

International Nuclear Information System (INIS)

Barbee, Nicole C.; Greig, Alan; Swearer, Stephen E.

2013-01-01

In this study we explore the use of fish otoliths (‘earbones’) as a tool for detecting exposure to heavy metals in sediments. Because otoliths are metabolically inert and incorporate chemical impurities during growth, they can potentially provide a more permanent record of pollutant exposure history in aquatic environments than soft tissues. To validate this technique we cultured embryos of a native Australian fish, the common Galaxias (Galaxias maculatus), in the laboratory on sediments spiked with copper in a concentration gradient. Our aims were to test whether exposure to copper contaminated sediments is recorded in the otoliths of embryos and determine over what range in concentrations we can detect differences in exposure. We found elevated copper levels in otoliths of embryos exposed to high copper concentrations in sediments, suggesting that otoliths can be used as a tool to track a history of exposure to elevated copper levels in the environment. -- Highlights: •Our aim was to determine if exposure to Cu is recorded in embryonic fish otoliths. •Fish eggs were cultured on Cu-spiked sediments in a gradient of concentrations. •Fish do uptake and incorporate Cu into their otoliths during development. •High sediment Cu concentrations resulted in high otolith Cu concentrations. •With further validation, otoliths could be used to track a history of Cu exposure. -- We use sediments spiked with Cu to examine the uptake of heavy metals into embryonic fish otoliths as a novel tool for tracking pollution exposure history

Biochemical and Physiological Responses in Atlantic Salmon (Salmo salar) Following Dietary Exposure to Copper and Cadmium

International Nuclear Information System (INIS)

Lundebye, A.-K.; Berntssen, M.H.G.; Bonga, S.E.Wendelaar; Maage, A.

1999-01-01

Three experiments were conducted with Atlantic salmon (Salmo salar) to assess the effects of dietary exposure to copper and cadmium. The results presented here provide an overview, details of each experiment will be published in full elsewhere. In the first experiment, salmon parr exposed for four weeks to 35 and 700 mg Cu kg -1 diet had significantly elevated intestinal copper concentrations, cell proliferation (PCNA) and apoptosis rates compared to control fish. No differences were observed in gill or plasma copper concentrations among the groups. In contrast to the controls, the Cu exposed groups did not grow significantly during the exposure period. The second experiment (three months exposure) was conducted to assess the effects of dietary copper (control, 35, 500, 700, 900 or 1750 mg Cu kg -1 diet) on growth and feed utilization in salmon fingerlings. Growth was significantly reduced after three months exposure to dietary Cu concentrations above 500 mg kg -1 . Similarly, copper body burdens were significantly higher in fish exposed to elevated dietary copper concentrations (above 35 mg Cu kg -1 diet). In the third experiment, salmon parr were exposed to one of six dietary cadmium concentrations (0, 0.5, 5, 25, 125 or 250 mg Cd kg -1 diet) for four months. Cadmium accumulated in the liver>intestine>gills of exposed fish. Rates of apoptosis and cell proliferation in the intestine increased following exposure to dietary cadmium. Exposure to elevated concentrations of dietary cadmium had no effect on growth in salmon parr. Results from these studies indicate that cellular biomarkers have potential as early warning signs of negative effects on the overall fitness of an organism

Prolonged particulate chromate exposure does not inhibit homologous recombination repair in North Atlantic right whale (Eubalaena glacialis) lung cells.

Science.gov (United States)

Browning, Cynthia L; Wise, Catherine F; Wise, John Pierce

2017-09-15

Chromosome instability is a common feature of cancers that forms due to the misrepair of DNA double strand breaks. Homologous recombination (HR) repair is a high fidelity DNA repair pathway that utilizes a homologous DNA sequence to accurately repair such damage and protect the genome. Prolonged exposure (>72h) to the human lung carcinogen, particulate hexavalent chromium (Cr(VI)), inhibits HR repair, resulting in increased chromosome instability in human cells. Comparative studies have shown acute Cr(VI) exposure induces less chromosome damage in whale cells than human cells, suggesting investigating the effect of this carcinogen in other species may inform efforts to prevent Cr(VI)-induced chromosome instability. Thus, the goal of this study was to determine the effect of prolonged Cr(VI) exposure on HR repair and clastogenesis in North Atlantic right whale (Eubalaena glacialis) lung cells. We show particulate Cr(VI) induces HR repair activity after both acute (24h) and prolonged (120h) exposure in North Atlantic right whale cells. Although the RAD51 response was lower following prolonged Cr(VI) exposure compared to acute exposure, the response was sufficient for HR repair to occur. In accordance with active HR repair, no increase in Cr(VI)-induced clastogenesis was observed with increased exposure time. These results suggest prolonged Cr(VI) exposure affects HR repair and genomic stability differently in whale and human lung cells. Future investigation of the differences in how human and whale cells respond to chemical carcinogens may provide valuable insight into mechanisms of preventing chemical carcinogenesis. Copyright © 2017. Published by Elsevier Inc.

Responses of Lyngbya wollei to exposures of copper-based algaecides: the critical burden concept.

Science.gov (United States)

Bishop, W M; Rodgers, J H

2012-04-01

The formulation of a specific algaecide can greatly influence the bioavailability, uptake, and consequent control of the targeted alga. In this research, three copper-based algaecide formulations were evaluated in terms of copper sorption to a specific problematic alga and amount of copper required to achieve control. The objectives of this study were (1) to compare the masses of copper required to achieve control of Lyngbya wollei using the algaecide formulations Algimycin-PWF, Clearigate, and copper sulfate pentahydrate in laboratory toxicity experiments; (2) to relate the responses of L. wollei to the masses of copper adsorbed and absorbed (i.e., dose) as well as the concentrations of copper in the exposure water; and (3) to discern the relation between the mass of copper required to achieve control of a certain mass of L. wollei among different algaecide formulations. The critical burden of copper (i.e., threshold algaecide concentration that must be absorbed or adsorbed to achieve control) for L. wollei averaged 3.3 and 1.9 mg Cu/g algae for Algimycin-PWF and Clearigate, respectively, in experiments with a series of aqueous copper concentrations, water volumes, and masses of algae. With reasonable exposures in these experiments, control was not achieved with single applications of copper sulfate despite copper sorption >13 mg Cu/g algae in one experiment. Factors governing the critical burden of copper required for control of problematic cyanobacteria include algaecide formulation and concentration, volume of water, and mass of algae. By measuring the critical burden of copper from an algaecide formulation necessary to achieve control of the targeted algae, selection of an effective product and treatment rate can be calculated at a given field site.

Systemic serum amyloid A as a biomarker for exposure to zinc and/or copper-containing metal fumes.

Science.gov (United States)

Baumann, R; Gube, M; Markert, A; Davatgarbenam, S; Kossack, V; Gerhards, B; Kraus, T; Brand, P

2018-01-01

Zinc- and copper-containing welding fumes increase systemic C-reactive protein (CRP). The aim of this study was to investigate the performance of the biomarkers serum amyloid A (SAA) and soluble vascular cell adhesion molecule-1 (VCAM-1) in this regard. Fifteen male subjects were exposed under controlled conditions to welding fumes containing either zinc, or copper, or copper and zinc for 6 h. Plasma samples were collected before, 6 and 24 h after start of exposure and biomarkers therein were measured by electrochemiluminescent assay. For each exposure, systemic concentrations of systemic SAA, but not VCAM-1, increased significantly at 24 h after exposure start compared with baseline ("copper only": P=0.0005, "zinc only": P=0.027, "copper and zinc": P=0.001). SAA showed a wider range of concentrations than did CRP and its levels increased up to 19-fold after welding fume exposure. The recognition of copper as a potential harmful component in welding fumes, also independent from zinc, deserves further consideration. SAA might represent a new sensitive biomarker for potential subclinical sterile inflammation after inhalation of copper- and/or zinc-containing welding fumes. As elevations of CRP and SAA protein have both been linked to a higher risk for cardiovascular disease, these findings might particularly be important for long-term welders.

Prolonged exposure to particulate chromate inhibits RAD51 nuclear import mediator proteins.

Science.gov (United States)

Browning, Cynthia L; Wise, John Pierce

2017-09-15

Particulate hexavalent chromium (Cr(VI)) is a human lung carcinogen and a human health concern. The induction of structural chromosome instability is considered to be a driving mechanism of Cr(VI)-induced carcinogenesis. Homologous recombination repair protects against Cr(VI)-induced chromosome damage, due to its highly accurate repair of Cr(VI)-induced DNA double strand breaks. However, recent studies demonstrate Cr(VI) inhibits homologous recombination repair through the misregulation of RAD51. RAD51 is an essential protein in HR repair that facilitates the search for a homologous sequence. Recent studies show prolonged Cr(VI) exposure prevents proper RAD51 subcellular localization, causing it to accumulate in the cytoplasm. Since nuclear import of RAD51 is crucial to its function, this study investigated the effect of Cr(VI) on the RAD51 nuclear import mediators, RAD51C and BRCA2. We show acute (24h) Cr(VI) exposure induces the proper localization of RAD51C and BRCA2. In contrast, prolonged (120h) exposure increased the cytoplasmic localization of both proteins, although RAD51C localization was more severely impaired. These results correlate temporally with the previously reported Cr(VI)-induced RAD51 cytoplasmic accumulation. In addition, we found Cr(VI) does not inhibit interaction between RAD51 and its nuclear import mediators. Altogether, our results suggest prolonged Cr(VI) exposure inhibits the nuclear import of RAD51C, and to a lesser extent, BRCA2, which results in the cytoplasmic accumulation of RAD51. Cr(VI)-induced inhibition of nuclear import may play a key role in its carcinogenic mechanism since the nuclear import of many tumor suppressor proteins and DNA repair proteins is crucial to their function. Copyright © 2017 Elsevier Inc. All rights reserved.

Media Impacts on Women's Fertility Desires: A Prolonged Exposure Experiment.

Science.gov (United States)

Knobloch-Westerwick, Silvia; Willis, Laura E; Kennard, Ashley R

2016-06-01

Media exposure may have implications for family planning, a public health issue of key importance. Drawing on social comparison theory and social identity theory, a prolonged exposure experiment examined whether media portrayals of women's social roles affect fertility desires among 166 American, nonstudent, never married, childless women ages 21-35 years old. After sign-up and baseline sessions, participants viewed magazine pages five days in a row. Stimuli presented women in either mother/homemaker roles, beauty ideal roles, or professional roles. Three days later, participants again indicated their number of desired children and time planned until first birth. Exposure to mother/homemaker and beauty ideal portrayals increased the number of desired children across time. Exposure to professional portrayals increased the time planned until 1st birth compared to beauty ideal portrayals-this impact was partially mediated by a shift toward more progressive gender norms (per social identity theory) and assimilation (per social comparison theory).

Copper-Based Aquatic Algaecide Adsorption and Accumulation Kinetics: Influence of Exposure Concentration and Duration for Controlling the Cyanobacterium Lyngbya wollei.

Science.gov (United States)

Bishop, West M; Lynch, Clayton L; Willis, Ben E; Cope, W Gregory

2017-09-01

Filamentous mat-forming cyanobacteria are increasingly impairing uses of freshwater resources. To effectively manage, a better understanding of control measures is needed. Copper (Cu)-based algaecide formulations are often applied to reactively control nuisance cyanobacterial blooms. This laboratory research assessed typical field exposure scenarios for the ability of Cu to partition to, and accumulate in Lyngbya wollei. Exposure factors (Cu concentration × duration) of 4, 8, 16, 24, 32 h were tested across three aqueous Cu concentrations (1, 2, 4 ppm). Results indicated that internally accumulated copper correlated with control of L. wollei, independent of adsorbed copper. L. wollei control was determined by filament viability and chlorophyll a concentrations. Similar exposure factors elicited similar internalized copper levels and consequent responses of L. wollei. Ultimately, a "concentration-exposure-time" (CET) model was created to assist water resource managers in selecting an appropriate treatment regime for a specific in-water infestation. By assessing the exposure concentration and duration required to achieve the internal threshold of copper (i.e., critical burden) that elicits control, water management objectives can be achieved while simultaneously decreasing the environmental loading of copper and potential for non-target species risks.

Implementation of Prolonged Exposure in the Army: Is Consultation Necessary for Effective Dissemination

Science.gov (United States)

2015-10-01

to hiring websites and local advertisements , and several candidates were identified. An initial part-time offer was made to Loreli Leos, LPC in July...2015). Prolonged exposure vs eye movement desensitization and reprocessing vs waiting list for posttraumatic stress disorder in patients with a

Chronic copper exposure and fatty acid composition of the amphipod Dikerogammarus villosus: Results from a field study

Energy Technology Data Exchange (ETDEWEB)

Maazouzi, Chafik [Universite de Metz, Laboratoire Interactions Ecotoxicologie Biodiversite Ecosystemes (LIEBE), CNRS UMR 7146, Avenue General Delestraint, 57070 Metz (France)], E-mail: maazouzi@univ-metz.fr; Masson, Gerard [Universite de Metz, Laboratoire Interactions Ecotoxicologie Biodiversite Ecosystemes (LIEBE), CNRS UMR 7146, Avenue General Delestraint, 57070 Metz (France)], E-mail: masson1@univ-metz.fr; Izquierdo, Maria Soledad [Grupo de Investigacion en Acuicultura, ULPGC and ICCM, P.O. Box 56, 35200 Telde, Las Palmas de Gran Canaria (Spain)], E-mail: mizquierdo@dbio.ulpgc.es; Pihan, Jean-Claude [Universite de Metz, Laboratoire Interactions Ecotoxicologie Biodiversite Ecosystemes (LIEBE), CNRS UMR 7146, Avenue General Delestraint, 57070 Metz (France)], E-mail: pihan@univ-metz.fr

2008-11-15

Field study allows assessment of long-term effects on fatty acid (FA) composition of organisms under chronic exposure to metals. One expected effect of copper is peroxidation of lipids and essentially polyunsaturated fatty acids (PUFA). FA analysis was established for the amphipod Dikerogammarus villosus subjected to different degrees of copper exposure (4-40 {mu}g Cu L{sup -1}). A previous study in our team showed that this species regulates its body Cu concentration (106-135 mg Cu kg{sup -1} dry weight). Despite the high capacity of bioaccumulation, the absence of a correlation between copper concentration in D. villosus and water prevents its use as bioindicator of copper pollution. Both sexes from the most polluted site showed the lowest total FA content, but the highest PUFA percent, mainly of the long-chained variety (C20-C22). Mechanisms leading to the prevention of lipid peroxidation in this species were discussed (metallothioneins and intracellular granules) and proposed with support from literature data. - Under chronic copper exposure, Dikerogammarus villosus loses in total fatty acids content but increases its essential {omega}3 and {omega}6 PUFA percent.

Dose formation and hematologic effects with prolonged internal exposure of rats by isotope 131I

International Nuclear Information System (INIS)

Sova, O.A.; Drozd, Yi.P.

2013-01-01

Processes in single dose formation and long-term domestic revenue 131 I in rats was investigated. Original method of estimating absorbed doses in hemacyte for macro-dosemeters indicators was proposed. Dose factors for hemacyte and the dynamics of the blood-forming organs doses for prolonged two cases of prolonged exposure was calculated. Hematologic effects were studied for two variants of entry of the isotope. Peculiarities of doses formation and identified hematological effects are discussed

Evidence of Complex Posttraumatic Stress Disorder (CPTSD) across populations with prolonged trauma of varying intensity and ages of exposure

DEFF Research Database (Denmark)

Palic, Sabina; Zerach, G; Shevlin, Mark

2016-01-01

, with a "Dissociative PTSD-subtype" class. ICD-11's CPTSD was not exclusively associated with childhood abuse, but also with exposure to adulthood trauma of severe interpersonal intensity. Furthermore, all types of prolonged trauma were equally associated with the "Anxiety symptoms" class. Finally, of all the classes......The ICD-11 proposes different types of prolonged trauma as risk factors for complex PTSD (CPTSD). However, CPTSD's construct validity has only been examined in childhood abuse, and single trauma exposure samples. Thus, the extent to which CPTSD applies to other repeatedly traumatized populations...... is unknown. This study examined ICD-11's PTSD and CPTSD across populations with prolonged trauma of varying interpersonal intensity and ages of exposure, including: 1) childhood sexual abuse, 2) adulthood trauma of severe interpersonal intensity (refugees and ex-prisoners of war), and 3) adulthood trauma...

Sound production in Japanese medaka (Oryzias latipes) and its alteration by exposure to aldicarb and copper sulfate.

Science.gov (United States)

Kang, Ik Joon; Qiu, Xuchun; Moroishi, Junya; Oshima, Yuji

2017-08-01

This study is the first to report sound production in Japanese medaka (Oryzias latipes). Sound production was affected by exposure to the carbamate insecticide (aldicarb) and heavy-metal compound (copper sulfate). Medaka were exposed at four concentrations (aldicarb: 0, 0.25, 0.5, and 1 mg L -1 ; copper sulfate: 0, 0.5, 1, and 2 mg L -1 ), and sound characteristics were monitored for 5 h after exposure. We observed constant average interpulse intervals (approx 0.2 s) in all test groups before exposure, and in the control groups throughout the experiment. The average interpulse interval became significantly longer during the recording periods after 50 min of exposure to aldicarb, and reached a length of more than 0.3 s during the recording periods after 120 min exposure. Most medaka fish stopped to produce sound after 50 min of exposure to copper sulfate at 1 and 2 mg L -1 , resulting in significantly declined number of sound pulses and pulse groups. Relative shortened interpulse intervals of sound were occasionally observed in medaka fish exposed to 0.5 mg L -1 copper sulfate. These alternations in sound characteristics due to toxicants exposure suggested that they might impair acoustic communication of medaka fish, which may be important for their reproduction and survival. Our results suggested that using acoustic changes of medaka has potential to monitor precipitate water pollutions, such as intentional poisoning or accidental leakage of industrial waste. Copyright © 2017 Elsevier Ltd. All rights reserved.

Protection of the public in situations of prolonged radiation exposure. The application of the Commission's system of radiological protection to controllable radiation exposure due to natural sources and long-lived radioactive residues.

Science.gov (United States)

1999-01-01

This report provides guidance on the application of the ICRP system of radiological protection to prolonged exposure situations affecting members of the public. It addresses the general application of the Commission's system to the control of prolonged exposures resulting from practices and to the undertaking of interventions in prolonged exposure situations. Additionally, it provides recommendations on generic reference levels for such interventions. The report also considers some specific situations and discusses a number of issues that have been of concern, namely: natural radiation sources that may give rise to high doses; the restoration and rehabilitation of sites where human activities involving radioactive substances have been carried out; the return to 'normality' following an accident that has released radioactive substances to the environment; and the global marketing of commodities for public consumption that contain radioactive substances. Annexes provide some examples of prolonged exposure situations and discuss the radiological protection quantities, radiation-induced health effects and aspects of the Commission's system of radiological protection relevant to prolonged exposure. Quantitative recommendations for prolonged exposures are provided in the report. They must be interpreted with extreme caution; Chapters 4 and 5 stress the upper bound nature of the following values: Generic reference levels for intervention, in terms of existing total annual doses, are given as < approximately 100 mSv, above which intervention is almost always justifiable (situations for which the annual dose threshold for deterministic effects in relevant organs is exceeded will almost always require intervention), and < approximately 10 mSv, below which intervention is not likely to be justifiable (and above which it may be necessary). Intervention exemption levels for commodities, especially building materials, are expressed as an additional annual dose of approximately 1

Physiological Stress Responses to Prolonged Exposure to MS-222 and Surgical Implantation in Juvenile Chinook Salmon

Energy Technology Data Exchange (ETDEWEB)

Wagner, Katie A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Woodley, Christa M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Seaburg, Adam [Univ. of Washington, Seattle, WA (United States); Skalski, John R. [Univ. of Washington, Seattle, WA (United States); Eppard, Matthew B. [U.S. Army Corps of Engineers, Portland, OR (United States)

2014-07-17

While many studies have investigated the effects of transmitters on fish condition, behavior, and survival, to our knowledge, no studies have taken into account anesthetic exposure time in addition to tag and surgery effects. We investigated stress responses to prolonged MS-222 exposure after stage 4 induction in surgically implanted juvenile Chinook salmon (Oncorhynchus tshawytscha). Survival, tag loss, plasma cortisol concentration, and blood Na⁺, K⁺, Ca²⁺, and pH were measured immediately following anesthetic exposure and surgical implantation and 1, 7, and 14 days post-treatment. Despite the prolonged anesthetic exposure, 3-15 minutes post Stage 4 induction, there were no mortalities or tag loss in any treatment. MS-222 was effective at delaying immediate cortisol release during surgical implantation; however, osmotic disturbances resulted, which were more pronounced in longer anesthetic time exposures. From day 1 to day 14, Na⁺, Ca²⁺, and pH significantly decreased, while cortisol significantly increased. The cortisol increase was exacerbated by surgical implantation. There was a significant interaction between MS-222 time exposure and observation day for Na⁺, Ca²⁺, K⁺, and pH; variations were seen in the longer time exposures, although not consistently. In conclusion, stress response patterns suggest stress associated with surgical implantation is amplified with increased exposure to MS-222.

Prolonged continuous exposure to high fine particulate matter associated with cardiovascular and respiratory disease mortality in Beijing, China

Science.gov (United States)

Wang, Jinfeng; Yin, Qian; Tong, Shilu; Ren, Zhoupeng; Hu, Maogui; Zhang, Hongrui

2017-11-01

Although many studies examined the effects of fine particulate matter (PM2.5) on the deaths of cardiovascular disease (CVD) and respiratory disease (RD), few research has paid attention to the effects of prolonged continuous exposure to high PM2.5 pollution. This study estimated the excess risks (ER) of CVD and RD mortalities associated with prolonged continuous exposure to high PM2.5 pollution for the whole population and specific subsociodemographic groups in Beijing, which is the capital city of China with over 20 million residents and having severe PM2.5 pollution problems. Our results suggested that when high PM2.5 pollution occurred continuously, at various thresholds and durations, the adverse effects on CVD and RD mortalities varied significantly. The CVD mortality risks in association with prolonged continuous high PM2.5 pollution exposure were more serious for single individuals (including unmarried, divorced, and widowed), illiterate and outdoor workers than for other specific subsociodemographic groups. When the daily PM2.5 concentration higher than 105 μg/m3 consecutively occurs, at the ninth day, the ERs of CVD death for single individuals, illiterate and outdoor workers groups reached to 45% (95% CI: 22, 71), 51% (95% CI: 28, 79) and 53% (95% CI: 29, 82) respectively. On the other hand, prolonged continuous high PM2.5 pollution level appeared to contribute a higher proportion of RD deaths among illiterate and outdoor workers, but less significant for the other specific subsociodemographic groups. When the duration with daily PM2.5 pollution higher than 115 μg/m3 reached to six days, the ERs for outdoor workers and illiterate attributed to prolonged continuous PM2.5 pollution exposure increased 36% (95% CI: 5, 76) and 49% (95% CI: 16, 91) respectively.

Prolonged Exposure Therapy for a Vietnam Veteran with PTSD and Early-Stage Dementia

Science.gov (United States)

Duax, Jeanne M.; Waldron-Perrine, Brigid; Rauch, Sheila A. M.; Adams, Kenneth M.

2013-01-01

Although prolonged exposure therapy (PE) is considered an evidence-based treatment for PTSD, there has been little published about the use of this treatment for older adults with comorbid early-stage dementia. As the number of older adults in the United States continues to grow, so will their unique mental health needs. The present article…

Effects of prolonged exposure to perchlorate on thyroid and reproductive function in zebrafish

Science.gov (United States)

Mukhi, S.; Patino, R.

2007-01-01

The objectives of this study were to determine the effects of prolonged exposure to perchlorate on (1) thyroid status and reproductive performance of adult zebrafish (Danio rerio) and (2) F1 embryo survival and early larval development. Using a static-renewal procedure, mixed sex populations of adult zebrafish were exposed to 0, 10, and 100 mg/l nominal concentrations of waterborne perchlorate for 10 weeks. Thyroid histology was qualitatively assessed, and females and males were separated and further exposed to their respective treatments for six additional weeks. Eight females in each tank replicate (n = 3) were paired weekly with four males from the same respective treatment, and packed-egg (spawn) volume (PEV) was measured each of the last five weeks. At least once during weeks 14-16 of exposure, other end points measured included fertilization rate, fertilized egg diameter, hatching rate, standard length, and craniofacial development of 4-day-postfertilization larvae and thyroid hormone content of 3.5-h embryos and of exposed mothers. At 10 weeks of exposure, perchlorate at both concentrations caused thyroidal hypertrophy and colloid depletion. A marked reduction in PEV was observed toward the end of the 6-week spawning period, but fertilization and embryo hatching rates were unaffected. Fertilized egg diameter and larval length were increased by parental exposure to perchlorate. Larval head depth was unaffected but the forward protrusion of the lower jaw-associated cartilage complexes, Meckel's and ceratohyal, was decreased. Exposure to both concentrations of perchlorate inhibited whole-body thyroxine content in mothers and embryos, but triiodothyronine content was unchanged. In conclusion, prolonged exposure of adult zebrafish to perchlorate not only disrupts their thyroid endocrine system but also impairs reproduction and influences early F1 development. ?? 2007 Oxford University Press.

Population growth rate and genetic variability of small and large populations of Red flour beetle (Tribolium castaneum) following multigenerational exposure to copper.

Science.gov (United States)

Laskowski, Ryszard; Radwan, Jacek; Kuduk, Katarzyna; Mendrok, Magdalena; Kramarz, Paulina

2015-07-01

We reared large (1000 individuals) and small (20 individuals) populations of Tribolium castaneum on diet contaminated with copper in order to determine if the size of a population affects its ability to adapt to adverse environmental conditions. After 10 generations, we used microsatellite markers to estimate and subsequently compare the genetic variability of the copper-treated populations with that of the control populations, which were reared on uncontaminated medium. Additionally, we conducted a full cross-factorial experiment which evaluated the effects of 10 generations of "pre-exposure" to copper on a population's fitness in control and copper-contaminated environments. In order to distinguish results potentially arising from genetic adaptation from those due to non-genetic effects associated to parental exposure to copper, we subjected also F11 generation, originating from parents not exposed to copper, to the same cross-factorial experiment. The effects of long-term exposure to copper depended on population size: the growth rates of small populations that were pre-exposed to copper were inhibited compared to those of small populations reared in uncontaminated environments. Large Cu-exposed populations had a higher growth rate in the F10 generation compared to the control groups, while the growth rate of the F11 generation was unaffected by copper exposure history. The only factor that had a significant effect on genetic variability was population size, but this was to be expected given the large difference in the number of individuals between large and small populations. Neither copper contamination nor its interaction with population size affected the number of microsatellite alleles retained in the F10 generation.

Neural Circuits via Which Single Prolonged Stress Exposure Leads to Fear Extinction Retention Deficits

Science.gov (United States)

Knox, Dayan; Stanfield, Briana R.; Staib, Jennifer M.; David, Nina P.; Keller, Samantha M.; DePietro, Thomas

2016-01-01

Single prolonged stress (SPS) has been used to examine mechanisms via which stress exposure leads to post-traumatic stress disorder symptoms. SPS induces fear extinction retention deficits, but neural circuits critical for mediating these deficits are unknown. To address this gap, we examined the effect of SPS on neural activity in brain regions…

Copper toxicity in housed lambs

Energy Technology Data Exchange (ETDEWEB)

Adamson, A H; Valks, D A; Appleton, M A; Shaw, W B

1969-09-27

Copper toxicity among 170 lambs artificially reared indoors at High Mowthorpe NAAS Experimental Husbandry Farm is reported. Although only three lambs were lost it is not unreasonable to suggest that the liver copper levels of the lambs which were slaughtered would have been high and losses could have been much heavier had there been any further copper supplementation. Even a copper level of 20 ppm in lamb concentrates given to lambs reared artificially indoors is dangerous, and intakes of much less than 38 mg per lamb per day can be fatal if given of a prolonged period. 5 references, 1 table.

Prolonged neuroinflammation after lipopolysaccharide exposure in aged rats.

Directory of Open Access Journals (Sweden)

Hui Qun Fu

Full Text Available Inflammation is a hallmark of several disease states ranging from neurodegeneration to sepsis but is also implicated in physiological processes like ageing. Non-resolving inflammation and prolonged neuroinflammation are unclear processes implicated in several conditions, including ageing. In this study we studied the long-term effects of endotoxemia, as systemic lipopolysaccharide (LPS injection, focusing on the role of astrocyte activation and cytokine release in the brain of aged rats. A single dose of LPS (2 mg/kg or 0.9% saline was injected intraperitoneally in aged rats. Levels of pro-inflammatory cytokines (TNFα and IL-1β and NF-κB p65 activation were measured systemically and in hippocampal tissue. Astrocytes and cytokines release in the CNS were detected via double immunofluorescence staining at different time-points up to day 30. Serum levels of TNFα and IL-1β were significantly increased acutely after 30 minutes (p<0.001 and up to 6 hours (p<0.001 following LPS-injection. Centrally, LPS-treated rats showed up-regulated mRNA expression and protein levels of pro-inflammatory cytokines in the hippocampus. These changes associated with astrogliosis in the hippocampus dentate gyrus (DG, IL-1β immunoreactivity and elevated NF-κB p65 expression up to day 30 post LPS exposure. Overall, these data demonstrate that LPS induces prolonged neuroinflammation and astrocyte activation in the hippocampus of aged rats. Hippocampal NF-κB p65 and excessive astrocytes-derived IL-1β release may play a pivotal role in regulating long-lasting neuroinflammation.

Relationship among aqueous copper half-lives and responses of Pimephales promelas to a series of copper sulfate pentahydrate concentrations.

Science.gov (United States)

Calomeni, Alyssa J; Kinley, Ciera M; Geer, Tyler D; Iwinski, Kyla J; Hendrikse, Maas; Rodgers, John H

2018-04-01

Copper algaecide exposures in situ are often of shorter duration than exposures for static toxicity experiments because aqueous concentrations in situ dissipate as a function of site-specific fate processes. Consequently, responses of organisms to static copper exposures may overestimate effects following in situ exposures. To understand the role of exposure duration for altering responses, Pimephales promelas survival was compared following static (96 h) and pulse (1.5, 4, 8, and 15 h half-lives) exposures of CuSO 4 •5H 2 O. Copper concentrations sorbed by fry indicated a consequence of different exposures. Responses of P. promelas to static exposures resulted in 96 h LC 50 s of 166 µgCu/L (95% confidence interval [CI], 142-189 µgCu/L) as soluble copper and 162 µgCu/L (CI, 140-183 µgCu/L) as acid soluble copper. Relative to static 96 h LC 50 s, exposures with half-lives of 1.5, 4 and 8 h resulted in LC 50 s 10, 3 and 2 times greater, respectively, for responses measured 96 h after exposure initiation. Copper concentrations extracted from fry exposed for 1.5, 4 and 8 h half-lives were less than the static experiment. However, copper sorbed by fry in the 15 h half-life experiment was not different than the static experiment. The relationship between 96 h LC 50 and 1/half-life was expressed using the equations y = 116 + 1360 × (R 2  = 0.97) for soluble copper and y = 147 + 1620 × (R 2  = 0.98) for acid soluble copper. Incorporation of exposure duration for predictions of P. promelas responses to copper pulse exposures increases prediction accuracy by an order of magnitude.

Chronic copper exposure causes spatial memory impairment, selective loss of hippocampal synaptic proteins, and activation of PKR/eIF2α pathway in mice.

Science.gov (United States)

Ma, Quan; Ying, Ming; Sui, Xiaojing; Zhang, Huimin; Huang, Haiyan; Yang, Linqing; Huang, Xinfeng; Zhuang, Zhixiong; Liu, Jianjun; Yang, Xifei

2015-01-01

Copper is an essential element for human growth and development; however, excessive intake of copper could contribute to neurotoxicity. Here we show that chronic exposure to copper in drinking water impaired spatial memory with simultaneous selective loss of hippocampal pre-synaptic protein synapsin 1, and post-synaptic density protein (PSD)-93/95 in mice. Copper exposure was shown to elevate the levels of nitrotyrosine and 8-hydroxydeoxyguanosine (8-OHdG) in hippocampus, two markers of oxidative stress. Concurrently, we also found that copper exposure activated double stranded RNA-dependent protein kinase (PKR) as evidenced by increased ratio of phosphorylated PKR at Thr451 and total PKR and increased the phosphorylation of its downstream signaling molecule eukaryotic initiation factor 2α (eIF2α) at Ser51 in hippocampus. Consistent with activation of PKR/eIF2α signaling pathway which was shown to mediate synaptic deficit and cognitive impairment, the levels of activating transcription factor 4 (ATF-4), a downstream signaling molecule of eIF2α and a repressor of CREB-mediated gene expression, were significantly increased, while the activity of cAMP response elements binding protein (CREB) was inactivated as suggested by decreased phosphorylation of CREB at Ser133 by copper exposure. In addition, the expression of the pro-apoptotic target molecule C/EBP homology protein (CHOP) of ATF-4 was upregulated and hippocampal neuronal apoptosis was induced by copper exposure. Taken together, we propose that chronic copper exposure might cause spatial memory impairment, selective loss of synaptic proteins, and neuronal apoptosis through the mechanisms involving activation of PKR/eIF2α signaling pathway.

Combined effects of sea water acidification and copper exposure on the symbiont-bearing foraminifer Amphistegina gibbosa

Science.gov (United States)

Marques, Joseane Aparecida; de Barros Marangoni, Laura Fernandes; Bianchini, Adalto

2017-06-01

Coral reefs are threatened by global and local stressors such as ocean acidification and trace metal contamination. Reliable early warning monitoring tools are needed to assess and monitor coral reef health. Symbiont-bearing foraminifers ( Amphistegina gibbosa) were kept under ambient conditions (no sea water acidification and no copper addition) or exposed to combinations of different levels of sea water pH (8.1, 7.8, 7.5 and 7.2) and environmentally relevant concentrations of dissolved copper (measured: 1.0, 1.6, 2.3 and 3.2 µg L-1) in a mesocosm system. After 10- and 25-d exposure, foraminifers were analyzed for holobiont Ca2+-ATPase activity, bleaching, growth and mortality. Enzyme activity was inhibited in foraminifers exposed to pH 7.2 and 3.2 µg L-1 Cu for 25 d. Bleaching frequency was also higher at pH 7.2 combined with copper addition. There was no significant effect of sea water acidification and copper addition on mortality. However, test size was smaller in foraminifers exposed to copper, with a positive interactive effect of sea water acidification. These findings can be explained by the higher availability of free copper ions at lower water pH. This condition would increase Cu competition with Ca2+ for the binding sites on the organism, thus inhibiting Ca2+-ATPase activity and affecting the organism's overall fitness. Findings reported here suggest that key processes in A. gibbosa, such as calcification and photosynthesis, are affected by the combined effect of global (sea water acidification) and local (copper contamination) stressors. Considering the experimental conditions employed (mesocosm system, possible ocean acidification scenarios, low copper concentrations, biomarkers of ecological relevance and chronic exposure), our findings support the use of foraminifera and biomarkers analyzed in the present study as reliable tools to detect and monitor the ecological impacts of multiple stressors in coral reef environments.

Advanced Copper Composites Against Copper-Tolerant Xanthomonas perforans and Tomato Bacterial Spot.

Science.gov (United States)

Strayer-Scherer, A; Liao, Y Y; Young, M; Ritchie, L; Vallad, G E; Santra, S; Freeman, J H; Clark, D; Jones, J B; Paret, M L

2018-02-01

Bacterial spot, caused by Xanthomonas spp., is a widespread and damaging bacterial disease of tomato (Solanum lycopersicum). For disease management, growers rely on copper bactericides, which are often ineffective due to the presence of copper-tolerant Xanthomonas strains. This study evaluated the antibacterial activity of the new copper composites core-shell copper (CS-Cu), multivalent copper (MV-Cu), and fixed quaternary ammonium copper (FQ-Cu) as potential alternatives to commercially available micron-sized copper bactericides for controlling copper-tolerant Xanthomonas perforans. In vitro, metallic copper from CS-Cu and FQ-Cu at 100 μg/ml killed the copper-tolerant X. perforans strain within 1 h of exposure. In contrast, none of the micron-sized copper rates (100 to 1,000 μg/ml) from Kocide 3000 significantly reduced copper-tolerant X. perforans populations after 48 h of exposure compared with the water control (P copper-based treatments killed the copper-sensitive X. perforans strain within 1 h. Greenhouse studies demonstrated that all copper composites significantly reduced bacterial spot disease severity when compared with copper-mancozeb and water controls (P copper composites significantly reduced disease severity when compared with water controls, using 80% less metallic copper in comparison with copper-mancozeb in field studies (P copper composites have the potential to manage copper-tolerant X. perforans and tomato bacterial spot.

Response of Escherichia coli to Prolonged Berberine Exposure.

Science.gov (United States)

Budeyri Gokgoz, Nilay; Avci, Fatma Gizem; Yoneten, Kubra Karaosmanoglu; Alaybeyoglu, Begum; Ozkirimli, Elif; Sayar, Nihat Alpagu; Kazan, Dilek; Sariyar Akbulut, Berna

2017-07-01

Berberine is a plant-derived alkaloid possessing antimicrobial activity; unfortunately, its efflux through multidrug resistance pumps reduces its efficacy. Cellular life span of Escherichia coli is generally shorter with prolonged berberine exposure; nevertheless, about 30% of the cells still remain robust following this treatment. To elucidate its mechanism of action and to identify proteins that could be involved in development of antimicrobial resistance, protein profiles of E. coli cells treated with berberine for 4.5 and 8 hours were compared with control cells. A total of 42 proteins were differentially expressed in cells treated with berberine for 8 hours when compared to control cells. In both 4.5 and 8 hours of berberine-treated cells, carbohydrate and peptide uptake regimens remained unchanged, although amino acid maintenance regimen switched from transport to synthesis. Defect in cell division persisted and this condition was confirmed by images obtained from scanning electron microscopy. Universal stress proteins were not involved in stress response. The significant increase in the abundance of elongation factors could suggest the involvement of these proteins in protection by exhibiting chaperone activities. Furthermore, the involvement of the outer membrane protein OmpW could receive special attention as a protein involved in response to antimicrobial agents, since the expression of only this porin protein was upregulated after 8 hours of exposure.

Stage specific effects of soluble copper and copper oxide nanoparticles during sea urchin embryo development and their relation to intracellular copper uptake.

Science.gov (United States)

Torres-Duarte, Cristina; Ramos-Torres, Karla M; Rahimoff, René; Cherr, Gary N

2017-08-01

The effects of exposure to either soluble copper (copper sulfate) or copper oxide nanoparticles (nano-CuO) during specific early developmental stages of sea urchin embryos were analyzed. Soluble copper caused significant malformations in embryos (skeletal malformations, delayed development or gut malformations) when present at any given stage, while cleavage stage was the most sensitive to nano-CuO exposure causing skeletal malformations and decreased total antioxidant capacity. The stage specificity was linked to higher endocytic activity during the first hours of development that leads to higher accumulation of copper in specific cells critical for development. Results indicate that nano-CuO results in higher accumulation of copper inside of embryos and this intracellular copper is more persistent as compared to soluble copper. The possible implications later in development are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Neural changes in extinction recall following prolonged exposure treatment for PTSD: A longitudinal fMRI study

Directory of Open Access Journals (Sweden)

Liat Helpman, PhD

2016-01-01

Conclusions: Prolonged exposure treatment appears to alter neural activation in PTSD patients during recall of fear extinction, and change in extinction recall (measured by SCR is associated with symptom reduction. We discuss results in the context of neural systems involved in response to affective stimuli.

Virtual reality exposure versus prolonged exposure for PTSD: Which treatment for whom?

Science.gov (United States)

Norr, Aaron M; Smolenski, Derek J; Katz, Andrea C; Rizzo, Albert A; Rothbaum, Barbara O; Difede, JoAnn; Koenen-Woods, Patricia; Reger, Mark A; Reger, Greg M

2018-06-01

The majority of studies comparing active psychological treatments for posttraumatic stress disorder (PTSD) do not find significant differences at posttreatment. This was the case in a recent trial examining prolonged exposure (PE) and virtual reality exposure (VRE) among active-duty soldiers with combat-related PTSD. Matching individual patients to specific treatments provides a potential avenue to improve significantly the public health impact of effective treatments for PTSD. A composite moderator approach was used to identify profiles of patients who would see superior PTSD symptom reduction in VRE or PE to inform future treatment matching. Active duty U.S. army soldiers (N = 108) were enrolled in a randomized clinical trial comparing VRE and PE in the treatment of PTSD stemming from deployments to Iraq or Afghanistan. Eighteen baseline variables were examined to identify treatment response heterogeneity in two patient groups: those with a superior response to PE and those with a superior response to VRE. The final composite moderator comprised four of 18 baseline variables. Results revealed that patients who were predicted to see greater PTSD symptom reduction in VRE were likely to be younger, not taking antidepressant medication, had greater PTSD hyperarousal symptoms, and were more likely to have greater than minimal suicide risk. Results suggest that treatment matching based on patient profiles could meaningfully improve treatment efficacy for combat-related PTSD. Future research can build on these results to improve our understanding of how to improve treatment matching for PTSD. © 2018 Wiley Periodicals, Inc.

Copper hypersensitivity

DEFF Research Database (Denmark)

Fage, Simon W; Faurschou, Annesofie; Thyssen, Jacob P

2014-01-01

hypersensitivity, a database search of PubMed was performed with the following terms: copper, dermatitis, allergic contact dermatitis, contact hypersensitivity, contact sensitization, contact allergy, patch test, dental, IUD, epidemiology, clinical, and experimental. Human exposure to copper is relatively common...

Chronic bronchiolitis in non-human primates after prolonged ozone exposure

International Nuclear Information System (INIS)

Eustis, S.L.

1979-01-01

Bonnet monkeys (Macaca radiata) were exposed to 0.0, 0.5, and 0.8 ppM ozone for 7, 28, or 90 consecutive d, eight h per d. Changes in the lung evoked by prolonged oxidant exposure were evaluated by light microscopy, scanning electron microscopy, transmission electron microscopy, autoradiography, and morphometry. Morphological changes were principally characterized as a low-grade chronic respiratory bronchiolitis. Proximal generations of respiratory bronchioles were the most consistently affected region of the pulmonary acinus. Major features of the bronchiolitis were intraluminal accumulations of macrophages and hypertrophy and hyperplasia of cuboidal bronchiolar epithelial cells. The degree of inflammation was greatest at the 0.8 ppM ozone concentration at each exposure period. The number of inflammatory cells observed at 90 d, however, was about one-half that observed at 7 d. Tritiated thymidine labeling and differential cell counts of respiratory bronchiolar epithelium demonstrated a proliferative response and an increase in the proportion of cubiodal bronchiolar cells which presumably function as the progenitor cell during cell renewal and repair of the epithelium. The labeling index remained elevated above control values through 90 d of ozone exposure despite a reduction below 7 d values at both 28 and 90 d. The epithelial hyperplasia persisted through 90 d at a level similar to but slightly above that present at 7 d. Since cell differentials remained shifted at 28 and 90 d, it appears that persistent ozone exposure delayed maturation and transformation of cubiodal bronchiolar cells to their mature phenotype

Prolonged Exposure Treatment of Chronic PTSD in Juvenile Sex Offenders: Promising Results from Two Case Studies

Science.gov (United States)

Hunter, John A.

2010-01-01

Prolonged exposure (PE) was used to treat chronic PTSD secondary to severe developmental trauma in two adolescent male sex offenders referred for residential sex offender treatment. Both youth were treatment resistant prior to initiation of PE and showed evidence of long-standing irritability and depression/anxiety. Clinical observation and…

Arsenic exposure levels in relation to different working departments in a copper mining and smelting plant

Science.gov (United States)

Sun, Qingshan; Song, Yingli; Liu, Shengnan; Wang, Fei; Zhang, Lin; Xi, Shuhua; Sun, Guifan

2015-10-01

The investigation was carried out to evaluate arsenic exposure and the urine metabolite profiles of workers with different working departments, including administration (Group1), copper ore mining (Group2), copper ore grinding (Group3), electrolytic procession (Group4) and copper smelting (Group5) in a Copper mining and processing plant in China. Information about characteristics of each subject was obtained by questionnaire and inorganic arsenic (iAs), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) in urine were determined. The highest urinary levels of iAs, MMA and DMA all were found in the Group 5. Group 4 workers had a higher iAs% and a lower PMI compared to Group 3. The urinary total As (TAs) levels of 54.7% subjects exceeded 50 μg/g Cr, and the highest percentage (93.3%) was found in Group 5, smelters. The results of the present study indicate that workers in copper production plant indeed exposed to As, especially for smelters and workers of electrolytic process.

Potential Adverse Effects of Prolonged Sevoflurane Exposure on Developing Monkey Brain: From Abnormal Lipid Metabolism to Neuronal Damage.

Science.gov (United States)

Liu, Fang; Rainosek, Shuo W; Frisch-Daiello, Jessica L; Patterson, Tucker A; Paule, Merle G; Slikker, William; Wang, Cheng; Han, Xianlin

2015-10-01

Sevoflurane is a volatile anesthetic that has been widely used in general anesthesia, yet its safety in pediatric use is a public concern. This study sought to evaluate whether prolonged exposure of infant monkeys to a clinically relevant concentration of sevoflurane is associated with any adverse effects on the developing brain. Infant monkeys were exposed to 2.5% sevoflurane for 9 h, and frontal cortical tissues were harvested for DNA microarray, lipidomics, Luminex protein, and histological assays. DNA microarray analysis showed that sevoflurane exposure resulted in a broad identification of differentially expressed genes (DEGs) in the monkey brain. In general, these genes were associated with nervous system development, function, and neural cell viability. Notably, a number of DEGs were closely related to lipid metabolism. Lipidomic analysis demonstrated that critical lipid components, (eg, phosphatidylethanolamine, phosphatidylserine, and phosphatidylglycerol) were significantly downregulated by prolonged exposure of sevoflurane. Luminex protein analysis indicated abnormal levels of cytokines in sevoflurane-exposed brains. Consistently, Fluoro-Jade C staining revealed more degenerating neurons after sevoflurane exposure. These data demonstrate that a clinically relevant concentration of sevoflurane (2.5%) is capable of inducing and maintaining an effective surgical plane of anesthesia in the developing nonhuman primate and that a prolonged exposure of 9 h resulted in profound changes in gene expression, cytokine levels, lipid metabolism, and subsequently, neuronal damage. Generally, sevoflurane-induced neuronal damage was also associated with changes in lipid content, composition, or both; and specific lipid changes could provide insights into the molecular mechanism(s) underlying anesthetic-induced neurotoxicity and may be sensitive biomarkers for the early detection of anesthetic-induced neuronal damage. Published by Oxford University Press on behalf of the

Quantifying fish swimming behavior in response to acute exposure of aqueous copper using computer assisted video and digital image analysis

Science.gov (United States)

Calfee, Robin D.; Puglis, Holly J.; Little, Edward E.; Brumbaugh, William G.; Mebane, Christopher A.

2016-01-01

Behavioral responses of aquatic organisms to environmental contaminants can be precursors of other effects such as survival, growth, or reproduction. However, these responses may be subtle, and measurement can be challenging. Using juvenile white sturgeon (Acipenser transmontanus) with copper exposures, this paper illustrates techniques used for quantifying behavioral responses using computer assisted video and digital image analysis. In previous studies severe impairments in swimming behavior were observed among early life stage white sturgeon during acute and chronic exposures to copper. Sturgeon behavior was rapidly impaired and to the extent that survival in the field would be jeopardized, as fish would be swept downstream, or readily captured by predators. The objectives of this investigation were to illustrate protocols to quantify swimming activity during a series of acute copper exposures to determine time to effect during early lifestage development, and to understand the significance of these responses relative to survival of these vulnerable early lifestage fish. With mortality being on a time continuum, determining when copper first affects swimming ability helps us to understand the implications for population level effects. The techniques used are readily adaptable to experimental designs with other organisms and stressors.

Evaluation of copper, aluminum bronze, and copper-nickel container material for the Yucca mountain project

International Nuclear Information System (INIS)

Kass, J.

1990-01-01

Copper, 70 percent aluminum bronze, and 70/30 copper-nickel were evaluated as potential waste-packaging materials as part of the Yucca Mountain Project. The proposed waste repository site is under a desert mountain in southern Nevada. The expected temperatures at the container surface are higher than at other sites, about 250C at the beginning of the containment period; they could fall below the boiling point of water during this period, but will be exposed to very little water, probably less than 5 l/a. Initial gamma flux will be 10 4 rad/h, and no significant hydrostatic or lithostatic pressure is expected. Packages will contain PWR or BWR fuel, or processed-glass waste. Three copper alloys are being considered for containers: oxygen-free copper (CDA 102); 7 percent aluminum bronze (CDA 613); and 70/30 copper-nickel (CDA 715). Phase separation due to prolonged thermal exposure could be a problem for the two alloys, causing embrittlement. The reduction of internal oxides present in pure copper by hydrogen could cause mechanical degradation. Corrosion and oxidation rates measured for the three materials in well water with and without gamma irradiation at flux rates about ten times higher than those expected were all quite small. The corrosion/oxidation rates for CDA715 show a marked increase under irradiation, but are still acceptable. In the presence of ammonia and other nitrogen-bearing species stress corrosion cracking (SCC) is a concern. Welded U-bend specimens of all three materials have been tested for up to 10000 h in highly irradiated environments, showing no SCC. There was some alloy segregation in the Al bronze specimens. The investigators believe that corrosion and mechanical properties will not present problems for these materials at this site. Further work is needed in the areas of weld inspection, welding techniques, embrittlement of weld metal, the effects of dropping the containers during emplacement, and stress corrosion cracking. Other materials

Acute and chronic sensitivity to copper of a promising ecotoxicological model species, the annual killifish Nothobranchius furzeri.

Science.gov (United States)

Philippe, Charlotte; Grégoir, Arnout F; Janssens, Lizanne; Pinceel, Tom; De Boeck, Gudrun; Brendonck, Luc

2017-10-01

Nothobranchius furzeri is a promising model for ecotoxicological research due to the species' short life cycle and the production of drought-resistant eggs. Although the species is an emerging vertebrate fish model for several fundamental as well as applied research domains, its potential for ecotoxicological research has not yet been tested. The aim of this study was to characterise the acute and chronic sensitivity of this species to copper as compared to other model organisms. Effects of both acute and chronic copper exposure were tested on survival, life history and physiological traits. We report a 24h-LC 50 of 53.93µg Cu/L, which is situated within the sensitivity range of other model species such as Brook Trout, Fathead Minnow and Rainbow Trout. Moreover, in the full life cycle exposure, we show that an exposure concentration of 10.27µg/L did not cause acute adverse effects (96h), but did cause mortality after prolonged exposure (3-4 weeks). Also chronic, sublethal effects were observed, such as a reduction in growth rate, delayed maturation and postponed reproduction. Based on our results, we define the NOEC at 6.68µg Cu/L, making N. furzeri more sensitive to copper as compared to Brook Trout and Fathead Minnow. We found stimulatory effects on peak fecundity at subinhibitory levels of copper concentrations (hormesis). Finally, we found indications for detoxifying and copper-excreting mechanisms, demonstrating the ability of the fish to cope with this essential metal, even when exposed to stressful amounts. The successful application of current ecotoxicological protocols on N. furzeri and its sensitivity range comparable to that of other model organisms forms the basis to exploit this species in further ecotoxicological practices. Copyright © 2017 Elsevier Inc. All rights reserved.

Concentration dependent transcriptome responses of zebrafish embryos after exposure to cadmium, cobalt and copper.

Science.gov (United States)

Sonnack, Laura; Klawonn, Thorsten; Kriehuber, Ralf; Hollert, Henner; Schäfers, Christoph; Fenske, Martina

2017-12-01

Environmental metals are known to cause harmful effects to fish of which many molecular mechanisms still require elucidation. Particularly concentration dependence of gene expression effects is unclear. Focusing on this matter, zebrafish embryo toxicity tests were used in combination with transcriptomics. Embryos were exposed to three concentrations of copper (CuSO 4 ), cadmium (CdCl 2 ) and cobalt (CoSO 4 ) from just after fertilization until the end of the 48hpf pre- and 96hpf post-hatch stage. The RNA was then analyzed on Agilent's Zebrafish (V3, 4×44K) arrays. Enrichment for GO terms of biological processes illustrated for cadmium that most affected GO terms were represented in all three concentrations, while for cobalt and copper most GO terms were represented in the lowest test concentration only. This suggested a different response to the non-essential cadmium than cobalt and copper. In cobalt and copper treated embryos, many developmental and cellular processes as well as the Wnt and Notch signaling pathways, were found significantly enriched. Also, different exposure concentrations affected varied functional networks. In contrast, the largest clusters of enriched GO terms for all three concentrations of cadmium included responses to cadmium ion, metal ion, xenobiotic stimulus, stress and chemicals. However, concentration dependence of mRNA levels was evident for several genes in all metal exposures. Some of these genes may be indicative of the mechanisms of action of the individual metals in zebrafish embryos. Real-time quantitative RT-PCR (qRT-PCR) verified the microarray data for mmp9, mt2, cldnb and nkx2.2a. Copyright © 2017 Elsevier Inc. All rights reserved.

Dynamic adaptation of cardiac baroreflex sensitivity to prolonged exposure to microgravity: data from a 16-day spaceflight

NARCIS (Netherlands)

Di Rienzo, Marco; Castiglioni, Paolo; Iellamo, Ferdinando; Volterrani, Maurizio; Pagani, Massimo; Mancia, Giuseppe; Karemaker, John M.; Parati, Gianfranco

2008-01-01

Di Rienzo M, Castiglioni P, Iellamo F, Volterrani M, Pagani M, Mancia G, Karemaker JM, Parati G. Dynamic adaptation of cardiac baroreflex sensitivity to prolonged exposure to microgravity: data from a 16-day spaceflight. J Appl Physiol 105: 1569-1575, 2008. First published August 28, 2008;

Corrosion and biofouling resistance evaluation of 90-10 copper-nickel

Energy Technology Data Exchange (ETDEWEB)

Powell, Carol [Consultant to Copper Development Association, UK, Square Covert, Caynham, Ludlow, Shropshire (United Kingdom)

2004-07-01

Copper-nickel alloys for marine use were developed for naval applications in the early part of the 20. century with a view to improving the corrosion resistance of condenser tubes and seawater piping. They still enjoy widespread use today not only for many navies but also in commercial shipping, floating production, storage and off loading vessels (FPSOs), and in multistage flash desalination. The two popular alloys contain 90% or 70% copper and differ in strength and maximum sea water velocity levels they can handle but it is the 90-10 copper-nickel (CuNi10Fe1Mn) which is the more economic and extensively used. An additional benefit of this alloy is its high resistance to biofouling: in recent years this has led to sheathing developments particularly for structures and boat hulls. This paper provides a review of the corrosion and biofouling resistance of 90-10 copper-nickel based on laboratory test data and documented experience of the alloy in marine environments. Particular attention is given to exposure trials over 8 years in Langstone Harbour, UK, which have recently been completed by Portsmouth University on behalf of the Nickel Institute. These examined four sheathing products; plate and foil as well as two composite products with rubber backing. The latter involved copper-nickel granules and slit sheet. The trial results are consistent with the behaviour of the alloy in the overall review. There is an inherent high resistance to marine biofouling when freely exposed. Prolonged exposure to quiet conditions can result in some growth of marine organisms but this is loosely attached and can readily be removed by wiping or a light scraping. The good corrosion resistance of 90-10 copper-nickel in sea water is also confirmed and associated with the formation of a thin, complex, protective and predominantly cuprous oxide surface film, which forms and matures naturally on exposure to seawater. Sound initial oxide film formation is also known to help protect against

Radiation-induced bystander effects in the Atlantic salmon (salmo salar L.) following mixed exposure to copper and aluminum combined with low-dose gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Mothersill, Carmel; Seymour, Colin B. [McMaster University, Medical Physics and Applied Radiation Sciences Department, Hamilton, ON (Canada); Norwegian University of Life Sciences, Department of Plant and Environmental Sciences, Aas (Norway); Smith, Richard W. [McMaster University, Medical Physics and Applied Radiation Sciences Department, Hamilton, ON (Canada); Heier, Lene Soerlie; Teien, Hans-Christian; Land, Ole Christian; Oughton, Deborah; Salbu, Brit [Norwegian University of Life Sciences, Department of Plant and Environmental Sciences, Aas (Norway)

2014-03-15

Very little is known about the combined effects of low doses of heavy metals and radiation. However, such ''multiple stressor'' exposure is the reality in the environment. In the work reported in this paper, fish were exposed to cobalt 60 gamma irradiation with or without copper or aluminum in the water. Doses of radiation ranged from 4 to 75 mGy delivered over 48 or 6 h. Copper doses ranged from 10 to 80 μg/L for the same time period. The aluminum dose was 250 μg/L. Gills and skin were removed from the fish after exposure and explanted in tissue culture flasks for investigation of bystander effects of the exposures using a stress signal reporter assay, which has been demonstrated to be a sensitive indicator of homeostatic perturbations in cells. The results show complex synergistic interactions of radiation and copper. Gills on the whole produce more toxic bystander signals than skin, but the additivity scores show highly variable results which depend on dose and time of exposure. The impacts of low doses of copper and low doses of radiation are greater than additive, medium levels of copper alone have a similar level of effect of bystander signal toxicity to the low dose. The addition of radiation stress, however, produces clear protective effects in the reporters treated with skin-derived medium. Gill-derived medium from the same fish did not show protective effects. Radiation exposure in the presence of 80 μg/L led to highly variable results, which due to animal variation were not significantly different from the effect of copper alone. The results are stressor type, stressor concentration and time dependent. Clearly co-exposure to radiation and heavy metals does not always lead to simple additive effects. (orig.)

In-situ real time measurements of net erosion rates of copper during hydrogen plasma exposure

Science.gov (United States)

Kesler, Leigh; Wright, Graham; Peterson, Ethan; Whyte, Dennis

2013-10-01

In order to properly understand the dynamics of net erosion/deposition in fusion reactors, such as tokamaks, a diagnostic measuring the real time rates of net erosion/deposition during plasma exposure is necessary. The DIONISOS experiment produces real time measurements of net erosion/deposition by using Rutherford backscattering spectroscopy (RBS) ion beam analysis simultaneously with plasma exposure from a helicon plasma source. This in-situ method improves on ex-situ weight loss measurements by allowing measurement of possible synergistic effects of high ion implantation rates and net erosion rate and by giving a real time response to changes in plasma parameters. Previous work has validated this new technique for measuring copper (Cu) erosion from helium (He) plasma ion bombardment. This technique is now extended to measure copper erosion due to deuterium and hydrogen plasma ion exposure. Targets used were a 1.5 μm Cu layer on an aluminum substrate. Cu layer thickness is tracked in real time using 1.2 MeV proton RBS. Measured erosion rates will be compared to results from literature and He erosion rates. Supported by US DoE award DE-SC00-02060.

Surface characteristics, copper release, and toxicity of nano- and micrometer-sized copper and copper(II) oxide particles: a cross-disciplinary study.

OpenAIRE

Midander, Klara; Cronholm, Pontus; Karlsson, Hanna L.; Elihn, Karine; Moller, Lennart; Leygraf, Christofer; Wallinder, Inger Odnevall

2009-01-01

An interdisciplinary and multianalytical research effort is undertaken to assess the toxic aspects of thoroughly characterized nano- and micrometer-sized particles of oxidized metallic copper and copper(II) oxide in contact with cultivated lung cells, as well as copper release in relevant media. All particles, except micrometer-sized Cu, release more copper in serum-containing cell medium (supplemented Dulbecco's minimal essential medium) compared to identical exposures in phosphate-buffered ...

Effects of prolonged exposure to space flight factors for 175 days on lettuce seeds

International Nuclear Information System (INIS)

Nevzgodina, L.V.; Maximova, E.N.; Akatov, Yu.A.

1981-01-01

The effects of prolonged (up to 175 days) exposure of Lactuca sativa seeds to space flight factors, including primary cosmic radiation heavy ions have been studied. The data obtained evidence a significant fourfold increase of spontaneous mutagenesis in seeds both with regard to the total number of aberrant cells as well as the formation of single cells with multiple aberrations. Comparison of the present experiment with earlier works shows that the frequency of such aberrations increases with the duration of the flight

Effects of Copper Exposure on Photosynthesis and Growth of the Seagrass Cymodocea nodosa: An Experimental Assessment.

Science.gov (United States)

Llagostera, Izaskun; Cervantes, Daniel; Sanmartí, Neus; Romero, Javier; Pérez, Marta

2016-09-01

Seagrasses form some of the most important coastal habitats. They may be negatively affected by trace metal contamination in certain coastal areas. In this study we experimentally assessed selected morphological and physiological traits of the seagrass Cymodocea nodosa, with increasing concentrations of copper (Cu) under controlled laboratory conditions. Short term (21 days) sub-lethal effects such as decreased maximum quantum yield, increased leaf necrosis and decreased shoot growth and shoot recruitment were clearly observed at the highest Cu exposure (5 mg L(-1)), while the effects were weaker at the intermediate concentration (2.5 mg L(-1)) and almost absent at the lowest concentration (1 mg L(-1)), indicating that this species is highly tolerant to copper exposure, at least in the short term. This fact could help to explain its distribution in relatively polluted coastal waters.

Inhibition in fertilisation of coral gametes following exposure to nickel and copper.

Science.gov (United States)

Gissi, Francesca; Stauber, Jenny; Reichelt-Brushett, Amanda; Harrison, Peter L; Jolley, Dianne F

2017-11-01

The mining and production of nickel in tropical regions have the potential to impact on ecologically valuable tropical marine ecosystems. Currently, few data exist to assess the risks of nickel exposure to tropical ecosystems and to derive ecologically relevant water quality guidelines. In particular, data are lacking for keystone species such as scleractinian corals, which create the complex structural reef habitats that support many other marine species. As part of a larger study developing risk assessment tools for nickel in the tropical Asia-Pacific region, we investigated the toxicity of nickel on fertilisation success in three species of scleractinian corals: Acropora aspera, Acropora digitifera and Platygyra daedalea. In the literature, more data are available on the effects of copper on coral fertilisation, so to allow for comparisons with past studies, the toxicity of copper to A. aspera and P. daedalea was also determined. Overall, copper was more toxic than nickel to the fertilisation success of the species tested. Acropora aspera was the most sensitive species to nickel (NOEC 4610µg Ni/L). Acropora aspera was also the more sensitive species to copper with an EC10 of 5.8µg Cu/L. The EC10 for P. daedalea was 16µg Cu/L, similar to previous studies. This is the first time that the toxicity of nickel on fertilisation success in Acropora species has been reported, and thus provides valuable data that can contribute to the development of reliable water quality guidelines for nickel in tropical marine waters. Copyright © 2017. Published by Elsevier Inc.

Pankiller effect of prolonged exposure to menadione on glioma cells: potentiation by vitamin C.

Science.gov (United States)

Vita, Marina F; Nagachar, Nivedita; Avramidis, Dimitrios; Delwar, Zahid M; Cruz, Mabel H; Siden, Åke; Paulsson, Kajsa M; Yakisich, Juan Sebastian

2011-12-01

Menadione (Vitamin K3) has anti-tumoral effects against a wide range of cancer cells. Its potential toxicity to normal cells and narrow therapeutic range limit its use as single agent but in combination with radiation or other anti-neoplastic agents can be of therapeutic use. In this paper, we first evaluated the early (within 3 h) effect of menadione on ongoing DNA replication. In normal rat cerebral cortex mini-units menadione showed an age dependent anti-proliferative effect. In tissue mini-units prepared from newborn rats, menadione inhibited ongoing DNA replication with an IC (50) of approximately 10 μM but 50 μM had no effect on mini-units from prepared adult rat tissue. The effect of short (72 h) and prolonged exposure (1-2 weeks) to menadione alone in the DBTRG.05MG human glioma cells line and in combination with vitamin C was studied. After short period of exposure data show that menadione alone or in combination with vitamin C provided similar concentration-response curves (and IC(50) values). Prolonged exposure to these drugs was evaluated by their ability to kill 100% of glioma cells and prevent regrowth when cells are re-incubated in drug-free media. In this long-term assay, menadione:vitamin C at a ratio 1:100 showed higher anti-proliferative activity when compared to each drug alone and allowed to reduce each drug concentration between 2.5 to 5-fold. Similar anti-proliferative effect was demonstrated in 8 patient derived glioblastoma cell cultures. Our data should be able to encourage further advanced studies on animal models to evaluate the potential use of this combination therapy for glioma treatment.

Glucocorticoid augmentation of prolonged exposure therapy: rationale and case report

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Laura Pratchett

2010-12-01

Full Text Available Rationale: Prolonged exposure (PE therapy has been found to reduce symptoms of posttraumatic stress disorder (PTSD; however, it is difficult for many patients to engage fully in the obligatory retelling of their traumatic experiences. This problem is compounded by the fact that habituation and cognitive restructuring – the main mechanisms through which PE is hypothesized to work – are not instantaneous processes, and often require several weeks before the distress associated with imaginal exposure abates. Case reports: Two cases are described that respectively illustrate the use of hydrocortisone and placebo, in combination with PE, for the treatment of combat-related PTSD. Based on known effects of glucocorticoids on learning and memory performance, we hypothesized that augmentation with hydrocortisone would improve the therapeutic effects of PE by hastening “new” learning and facilitating decreases in the emotional impact of fear memories during the course of treatment. The veteran receiving hydrocortisone augmentation of PE displayed an accelerated and ultimately greater decline in PTSD symptoms than the veteran receiving placebo. Conclusions: While no general conclusion can be derived from comparison of two patients, the findings are consistent with the rationale for augmentation. These case reports support the potential for an appropriately designed and powered clinical trial to examine the efficacy of glucocorticoids in augmenting the effects of psychotherapy for PTSD.

Bacterial Killing by Dry Metallic Copper Surfaces▿

OpenAIRE

Santo, Christophe Espírito; Lam, Ee Wen; Elowsky, Christian G.; Quaranta, Davide; Domaille, Dylan W.; Chang, Christopher J.; Grass, Gregor

2010-01-01

Metallic copper surfaces rapidly and efficiently kill bacteria. Cells exposed to copper surfaces accumulated large amounts of copper ions, and this copper uptake was faster from dry copper than from moist copper. Cells suffered extensive membrane damage within minutes of exposure to dry copper. Further, cells removed from copper showed loss of cell integrity. Acute contact with metallic copper surfaces did not result in increased mutation rates or DNA lesions. These findings are important fir...

Performance of copper-based wood preservatives in soil bed exposures

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Stan T. Lebow; Thomas Nilsson; Jeffrey J. Morrell

Copper-based biocides are widely used to protect wood from biological attack in a variety of environments. Chromated copper arsenate (CCA) is the dominant copper-based preservative for wood protection (J. T. MICKLEWRIGHT, 1989). First developed in India in the 1930s, CCA contains a very effective combination of materials. Copper provides protection against most...

Immunotoxicity of copper nanoparticle and copper sulfate in a common Indian earthworm.

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Gautam, Arunodaya; Ray, Abhishek; Mukherjee, Soumalya; Das, Santanu; Pal, Kunal; Das, Subhadeep; Karmakar, Parimal; Ray, Mitali; Ray, Sajal

2018-02-01

Copper oxide nanoparticles and copper sulfate are established contaminants of water and soil. Metaphire posthuma is a common variety of earthworm distributed in moist soil of Indian subcontinent. Comparative toxicity of copper nanoparticles and copper sulfate were investigated with reference to selected immune associated parameters of earthworm. Total count, phagocytic response, generation of cytotoxic molecules (superoxide anion, nitric oxide), activities of enzymes like phenoloxidase, superoxide dismutase, catalase, acid phosphatase, alkaline phosphatase and total protein of coelomocytes were estimated under the exposures of 100, 500, 1000mg of copper oxide nanoparticles and copper sulfate per kg of soil for 7 and 14 d. A significant decrease in the total coelomocyte count were recorded with maximum depletion as 15.45 ± 2.2 and 12.5 ± 2 × 10 4 cells/ml under the treatment of 1000mg/kg of copper nanoparticles and copper sulfate for 14 d respectively. A significant decrease in generation of nitric oxide and activity of phenoloxidase were recorded upon exposure of both toxins for 7 and 14 d indicating possible decline in cytotoxic status of the organism. A maximum inhibition of superoxide dismutase activity was recorded as 0.083 ± 0.0039 and 0.055 ± 0.0057 unit/mg protein/minute against 1000mg/kg of copper nanoparticles and copper sulfate treatment for 14 d respectively. Activities of catalase and alkaline phosphatase were inhibited by all experimental concentrations of both toxins in the coelomocytes of earthworm. These toxins were recorded to be modifiers of the major immune associated parameters of M. posthuma. Unrestricted contamination of soil by sulfate and oxide nanoparticles of copper may lead to an undesirable shift in the innate immunological status of earthworm leading to a condition of immune compromisation and shrinkage in population density of this species in its natural habitat. This article is the first time report of immunological toxicity of

Integrating Dialectical Behavior Therapy and Prolonged Exposure to Treat Co-Occurring Borderline Personality Disorder and PTSD: Two Case Studies

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Harned, Melanie S.; Linehan, Marsha M.

2008-01-01

Despite the high rate of trauma and PTSD among individuals with borderline personality disorder (BPD), no studies have specifically evaluated the treatment of PTSD in a BPD population. These case studies illustrate the use of a protocol based on prolonged exposure therapy that can be integrated into standard dialectical behavior therapy to treat…

Environmental Exposure to Arsenic, Lead, and Cadmium in People Living near Janghang Copper Smelter in Korea.

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Kim, Yong-Dae; Eom, Sang-Yong; Yim, Dong-Hyuk; Kim, In-Soo; Won, Hee-Kwan; Park, Choong-Hee; Kim, Guen-Bae; Yu, Seung-Do; Choi, Byung-Sun; Park, Jung-Duck; Kim, Heon

2016-04-01

Concentrations of heavy metals exceed safety thresholds in the soil near Janghang Copper Refinery, a smelter in Korea that operated from 1936 to 1989. This study was conducted to evaluate the level of exposure to toxic metals and the potential effect on health in people living near the smelter. The study included 572 adults living within 4 km of the smelter and compared them with 413 controls group of people living similar lifestyles in a rural area approximately 15 km from the smelter. Urinary arsenic (As) level did not decrease according to the distance from the smelter, regardless of gender and working history in smelters and mines. However, in subjects who had no occupational exposure to toxic metals, blood lead (Pb) and cadmium (Cd) and urinary Cd decreased according to the distance from the smelter, both in men and women. Additionally, the distance from the smelter was a determinant factor for a decrease of As, Pb, and Cd in multiple regression models, respectively. On the other hands, urinary Cd was a risk factor for renal tubular dysfunction in populations living near the smelter. These results suggest that Janghang copper smelter was a main contamination source of As, Pb, and Cd, and populations living near the smelter suffered some adverse health effects as a consequence. The local population should be advised to make efforts to reduce exposure to environmental contaminants, in order to minimize potential health effects, and to pay close attention to any health problems possibly related to toxic metal exposure.

Previous Repeated Exposure to Food Limitation Enables Rats to Spare Lipid Stores during Prolonged Starvation.

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McCue, Marshall D; Albach, Audrey; Salazar, Giovanni

The risk of food limitation and, ultimately, starvation dates back to the dawn of heterotrophy in animals, yet starvation remains a major factor in the regulation of modern animal populations. Researchers studying starvation more than a century ago suggested that animals subjected to sublethal periods of food limitation are somehow more tolerant of subsequent starvation events. This possibility has received little attention over the past decades, yet it is highly relevant to modern science for two reasons. First, animals in natural populations are likely to be exposed to bouts of food limitation once or more before they face prolonged starvation, during which the risk of mortality becomes imminent. Second, our current approach to studying starvation physiology in the laboratory focuses on nourished animals with no previous exposure to nutritional stress. We examined the relationship between previous exposure to food limitation and potentially adaptive physiological responses to starvation in adult rats and found several significant differences. On two occasions, rats were fasted until they lost 20% of their body mass maintained lower body temperatures, and had presumably lower energy requirements when subjected to prolonged starvation than their naive cohort that never experienced food limitation. These rats that were trained in starvation also had lower plasma glucose set -points and reduced their reliance on endogenous lipid oxidation. These findings underscore (1) the need for biologists to revisit the classic hypothesis that animals can become habituated to starvation, using a modern set of research tools; and (2) the need to design controlled experiments of starvation physiology that more closely resemble the dynamic nature of food availability.

Effects of chronic copper exposure during early life in rhesus monkeys.

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Araya, Magdalena; Kelleher, Shannon L; Arredondo, Miguel A; Sierralta, Walter; Vial, María Teresa; Uauy, Ricardo; Lönnerdal, Bo

2005-05-01

Whether infants regulate copper absorption and the potential effects of excess copper in early life remain poorly defined. The objective of the study was to assess copper retention, liver copper content, and liver function in infant rhesus monkeys fed infant formula containing 6.6 mg Cu/L. From birth to 5 mo of age, infant rhesus monkeys were fed formula that was supplemented with copper (0.6 mg Cu/L; n = 5) or not supplemented (n = 4). In all animals, weight and crown-rump length (by anthropometry), hemoglobin, hematocrit, plasma ceruloplasmin activity, and zinc and copper concentrations were measured monthly (birth to 6 mo) and at 8 and 12 mo. When the animals were 1, 5, and 8 mo old, liver copper and metallothionein concentrations, liver histology (by light and electron microscopy), and the number of Kupffer cells were assessed, and 67Cu retention was measured. Liver function was assessed by measurement of plasma alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, and alkaline phosphatase activities and protein, albumin, bilirubin, and blood urea nitrogen concentrations. 67Cu retention was 19.2% and 10.9% after 1 and 5 mo of copper treatment, respectively, compared with approximately 75% in controls at age 2 mo. At age 8 mo, 67Cu retention was 22.9% in copper-treated animals and 31.5% in controls. Liver histology remained normal by light microscopy, with mild ultrastructural signs of cell damage at 5 mo. Liver copper concentration was 4711, 1139, and 498 microg/g dry tissue at 1, 5, and 8 mo, respectively, in copper-treated animals and 250 microg/g at 2 mo in controls. Measurements could not be completed in all animals. No clinical evidence of copper toxicity was observed. Copper absorption was down-regulated; increases in liver copper content at ages 1 and 5 mo did not result in histologic damage. Ultrastructural changes at age 5 mo could signal early cellular damage.

Severe, multimodal stress exposure induces PTSD-like characteristics in a mouse model of single prolonged stress.

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Perrine, Shane A; Eagle, Andrew L; George, Sophie A; Mulo, Kostika; Kohler, Robert J; Gerard, Justin; Harutyunyan, Arman; Hool, Steven M; Susick, Laura L; Schneider, Brandy L; Ghoddoussi, Farhad; Galloway, Matthew P; Liberzon, Israel; Conti, Alana C

2016-04-15

Appropriate animal models of posttraumatic stress disorder (PTSD) are needed because human studies remain limited in their ability to probe the underlying neurobiology of PTSD. Although the single prolonged stress (SPS) model is an established rat model of PTSD, the development of a similarly-validated mouse model emphasizes the benefits and cross-species utility of rodent PTSD models and offers unique methodological advantages to that of the rat. Therefore, the aims of this study were to develop and describe a SPS model for mice and to provide data that support current mechanisms relevant to PTSD. The mouse single prolonged stress (mSPS) paradigm, involves exposing C57Bl/6 mice to a series of severe, multimodal stressors, including 2h restraint, 10 min group forced swim, exposure to soiled rat bedding scent, and exposure to ether until unconsciousness. Following a 7-day undisturbed period, mice were tested for cue-induced fear behavior, effects of paroxetine on cue-induced fear behavior, extinction retention of a previously extinguished fear memory, dexamethasone suppression of corticosterone (CORT) response, dorsal hippocampal glucocorticoid receptor protein and mRNA expression, and prefrontal cortex glutamate levels. Exposure to mSPS enhanced cue-induced fear, which was attenuated by oral paroxetine treatment. mSPS also disrupted extinction retention, enhanced suppression of stress-induced CORT response, increased mRNA expression of dorsal hippocampal glucocorticoid receptors and decreased prefrontal cortex glutamate levels. These data suggest that the mSPS model is a translationally-relevant model for future PTSD research with strong face, construct, and predictive validity. In summary, mSPS models characteristics relevant to PTSD and this severe, multimodal stress modifies fear learning in mice that coincides with changes in the hypothalamo-pituitary-adrenal (HPA) axis, brain glucocorticoid systems, and glutamatergic signaling in the prefrontal cortex

Copper Resistance of the Emerging Pathogen Acinetobacter baumannii

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Williams, Caitlin L.; Neu, Heather M.; Gilbreath, Jeremy J.; Michel, Sarah L. J.; Zurawski, Daniel V.

2016-01-01

ABSTRACT Acinetobacter baumannii is an important emerging pathogen that is capable of causing many types of severe infection, especially in immunocompromised hosts. Since A. baumannii can rapidly acquire antibiotic resistance genes, many infections are on the verge of being untreatable, and novel therapies are desperately needed. To investigate the potential utility of copper-based antibacterial strategies against Acinetobacter infections, we characterized copper resistance in a panel of recent clinical A. baumannii isolates. Exposure to increasing concentrations of copper in liquid culture and on solid surfaces resulted in dose-dependent and strain-dependent effects; levels of copper resistance varied broadly across isolates, possibly resulting from identified genotypic variation among strains. Examination of the growth-phase-dependent effect of copper on A. baumannii revealed that resistance to copper increased dramatically in stationary phase. Moreover, A. baumannii biofilms were more resistant to copper than planktonic cells but were still susceptible to copper toxicity. Exposure of bacteria to subinhibitory concentrations of copper allowed them to better adapt to and grow in high concentrations of copper; this copper tolerance response is likely achieved via increased expression of copper resistance mechanisms. Indeed, genomic analysis revealed numerous putative copper resistance proteins that share amino acid homology to known proteins in Escherichia coli and Pseudomonas aeruginosa. Transcriptional analysis revealed significant upregulation of these putative copper resistance genes following brief copper exposure. Future characterization of copper resistance mechanisms may aid in the search for novel antibiotics against Acinetobacter and other highly antibiotic-resistant pathogens. IMPORTANCE Acinetobacter baumannii causes many types of severe nosocomial infections; unfortunately, some isolates have acquired resistance to almost every available antibiotic

Copper Resistance of the Emerging Pathogen Acinetobacter baumannii.

Science.gov (United States)

Williams, Caitlin L; Neu, Heather M; Gilbreath, Jeremy J; Michel, Sarah L J; Zurawski, Daniel V; Merrell, D Scott

2016-10-15

Acinetobacter baumannii is an important emerging pathogen that is capable of causing many types of severe infection, especially in immunocompromised hosts. Since A. baumannii can rapidly acquire antibiotic resistance genes, many infections are on the verge of being untreatable, and novel therapies are desperately needed. To investigate the potential utility of copper-based antibacterial strategies against Acinetobacter infections, we characterized copper resistance in a panel of recent clinical A. baumannii isolates. Exposure to increasing concentrations of copper in liquid culture and on solid surfaces resulted in dose-dependent and strain-dependent effects; levels of copper resistance varied broadly across isolates, possibly resulting from identified genotypic variation among strains. Examination of the growth-phase-dependent effect of copper on A. baumannii revealed that resistance to copper increased dramatically in stationary phase. Moreover, A. baumannii biofilms were more resistant to copper than planktonic cells but were still susceptible to copper toxicity. Exposure of bacteria to subinhibitory concentrations of copper allowed them to better adapt to and grow in high concentrations of copper; this copper tolerance response is likely achieved via increased expression of copper resistance mechanisms. Indeed, genomic analysis revealed numerous putative copper resistance proteins that share amino acid homology to known proteins in Escherichia coli and Pseudomonas aeruginosa Transcriptional analysis revealed significant upregulation of these putative copper resistance genes following brief copper exposure. Future characterization of copper resistance mechanisms may aid in the search for novel antibiotics against Acinetobacter and other highly antibiotic-resistant pathogens. Acinetobacter baumannii causes many types of severe nosocomial infections; unfortunately, some isolates have acquired resistance to almost every available antibiotic, and treatment options

Behavioral and dermatologic changes and low serum zinc and copper concentrations in two premature infants after parenteral alimentation.

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Sivasubramanian, K N; Henkin, R I

1978-11-01

Two premature infants were observed to develop behavioral and dermatologic changes and low serum zinc and copper concentrations following cessation of prolonged parenteral alimentation, while being fed exclusively with human milk. Following treatment with exogenous oral zinc supplementation, prompt relief of symptoms and increases of serum zinc and copper concentrations were observed in both infants. These patients comprise about 5% of our premature infants who are treated with parenteral alimentation for more than two weeks. We recommend that premature infants on prolonged parenteral alimentation should be monitored for changes in serum zinc and copper concentrations and, if a marked fall is observed, supplementation should be considered.

Feasibility and Efficacy of Prolonged Exposure for PTSD among Individuals with a Psychotic Spectrum Disorder

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Anouk L. Grubaugh

2017-06-01

Full Text Available Objective: Few empirical studies have examined the feasibility of trauma-focused treatment among individuals with schizophrenia. This lack of research is important given the substantial overlap of trauma exposure and subsequent PTSD with psychotic spectrum disorders, and the potential for PTSD to complicate the course and prognosis of schizophrenia and other variants of severe mental illness.Method: As part of a larger study, 14 veterans with a psychotic spectrum disorder were enrolled to receive prolonged exposure (PE for PTSD within a single arm open trial study design. Patient reactions and responses to PE were examined using feasibility indices such as attrition, survey reactions, and treatment expectancy; pre and post-changes in PTSD severity and diagnostic status; and thematic interviews conducted post-intervention.Results: Quantitative and qualitative data indicate that implementation of PE is feasible, subjectively well-tolerated, and may result in clinically significant reductions in PTSD symptoms in patients with psychotic spectrum disorders.Conclusion: Consistent with treatment outcome data in clinical populations with a broader range of severe mental illnesses, the current results support the use of PTSD exposure-based interventions, such as PE, for individuals with psychotic spectrum disorders.

Cell density dependence of Microcystis aeruginosa responses to copper algaecide concentrations: Implications for microcystin-LR release.

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Kinley, Ciera M; Iwinski, Kyla J; Hendrikse, Maas; Geer, Tyler D; Rodgers, John H

2017-11-01

Along with mechanistic models, predictions of exposure-response relationships for copper are often derived from laboratory toxicity experiments with standardized experimental exposures and conditions. For predictions of copper toxicity to algae, cell density is a critical factor often overlooked. For pulse exposures of copper-based algaecides in aquatic systems, cell density can significantly influence copper sorbed by the algal population, and consequent responses. A cyanobacterium, Microcystis aeruginosa, was exposed to a copper-based algaecide over a range of cell densities to model the density-dependence of exposures, and effects on microcystin-LR (MC-LR) release. Copper exposure concentrations were arrayed to result in a gradient of MC-LR release, and masses of copper sorbed to algal populations were measured following exposures. While copper exposure concentrations eliciting comparable MC-LR release ranged an order of magnitude (24-h EC50s 0.03-0.3mg Cu/L) among cell densities of 10 6 through 10 7 cells/mL, copper doses (mg Cu/mg algae) were similar (24-h EC50s 0.005-0.006mg Cu/mg algae). Comparisons of MC-LR release as a function of copper exposure concentrations and doses provided a metric of the density dependence of algal responses in the context of copper-based algaecide applications. Combined with estimates of other site-specific factors (e.g. water characteristics) and fate processes (e.g. dilution and dispersion, sorption to organic matter and sediments), measuring exposure-response relationships for specific cell densities can refine predictions for in situ exposures and algal responses. These measurements can in turn decrease the likelihood of amending unnecessary copper concentrations to aquatic systems, and minimize risks for non-target aquatic organisms. Copyright © 2017 Elsevier Inc. All rights reserved.

Copper excess-induced large reversible and small irreversible adaptations in a population of Chlamydomonas reinhardtii CW15 (Chlorophyta

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Bartosz Pluciński

2018-03-01

Full Text Available Two Chlamydomonas reinhardtii CW15 populations modified by an excess of copper in growth medium were obtained: a “Cu” population that was continuously grown under the selection pressure of 5 µM Cu2+ (for at least 48 weeks and the “Re” population, where a relatively short (9 week exposure to elevated copper, necessary for acquiring tolerance, was followed by a prolonged period (at least 39 weeks of cultivation at a normal (0.25 µM copper concentration. Cells of the Cu population were able to multiply at a Cu2+ concentration 16 times higher than that of the control population at a normal light intensity and at a Cu2+ concentration 64 times higher when cultivated in dim light. The potential quantum yield of photosystem II (FV/FM ratio under copper stress was also significantly higher for the Cu population than for Re and control populations. The Re population showed only residual tolerance towards the elevated concentration of copper, which is revealed by an FV/FM ratio slightly higher than in the control population under Cu2+ stress in dim light or in darkness. We postulate that in the Chlamydomonas populations studied in this paper, at least two mechanisms of copper tolerance operate. The first mechanism is maintained during cultivation at a standard copper concentration and seems to be connected with photosynthetic apparatus. This mechanism, however, has only low adaptive value under excess of copper. The other mechanism, with a much higher adaptive value, is probably connected with Cu2+ homeostasis at the cellular level, but is lost during cultivation at a normal copper concentration.

Vectorization of copper complexes via biocompatible and biodegradable PLGA nanoparticles.

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Courant, T; Roullin, V G; Cadiou, C; Delavoie, F; Molinari, M; Andry, M C; Gafa, V; Chuburu, F

2010-04-23

A double emulsion-solvent diffusion approach with fully biocompatible materials was used to encapsulate copper complexes within biodegradable nanoparticles, for which the release kinetics profiles have highlighted their potential use for a prolonged circulating administration.

Vectorization of copper complexes via biocompatible and biodegradable PLGA nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Courant, T; Roullin, V G; Andry, M C [Institut de Chimie Moleculaire de Reims, CNRS UMR 6229, UFR Pharmacie Reims, 51 rue Cognacq-Jay, F-51100 Reims (France); Cadiou, C; Chuburu, F [Institut de Chimie Moleculaire de Reims, CNRS UMR 6229, UFR des Sciences Exactes et Naturelles, Batiment 18-Europol' Agro, BP 1039, F-51687 Reims Cedex 2 (France); Delavoie, F [Laboratoire de Microscopie Electronique Analytique, INSERM UMRS 926, 21 rue Clement Ader, F-51685 Reims Cedex 2 (France); Molinari, M [Laboratoire de Microscopies et d' Etudes des Nanostructures, UFR des Sciences, Universite de Reims Champagne-Ardenne, 21 rue Clement Ader, F-51685 Reims Cedex 2 (France); Gafa, V, E-mail: gaelle.roullin@univ-reims.fr, E-mail: francoise.chuburu@univ-reims.fr [EA4303 ' Inflammation et Immunite de l' Epithelium Respiratoire' , IFR53, UFR de Pharmacie, Universite de Reims Champagne-Ardenne, 51 rue Cognacq-Jay, F-51100 Reims (France)

2010-04-23

A double emulsion-solvent diffusion approach with fully biocompatible materials was used to encapsulate copper complexes within biodegradable nanoparticles, for which the release kinetics profiles have highlighted their potential use for a prolonged circulating administration.

Vectorization of copper complexes via biocompatible and biodegradable PLGA nanoparticles

International Nuclear Information System (INIS)

Courant, T; Roullin, V G; Andry, M C; Cadiou, C; Chuburu, F; Delavoie, F; Molinari, M; Gafa, V

2010-01-01

A double emulsion-solvent diffusion approach with fully biocompatible materials was used to encapsulate copper complexes within biodegradable nanoparticles, for which the release kinetics profiles have highlighted their potential use for a prolonged circulating administration.

Elastic stockings effect on leg volume variability in healthy workers under prolonged gravitational gradient exposure

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Mirko Tessari

2015-06-01

Full Text Available The aim of this study was to determine the elastic stockings effect on healthy workers (HW who are exposed to a prolonged hydrostatic pressure overload for professional reasons. The cohort was composed by 20 HW who voluntarily underwent a water plethysmography test before and after eight hour of standing up in an operating room, wearing elastic stockings. After 8 h of gravity exposure, we demonstrated the absence of leg volume increase in case of elastic stockings use. In the morning measurement we found that the lower limb volume was 1967.5 mL±224, while in the evening it was 1962.5 mL±227 (P<0.0828. The decreased volume is significantly correlated with the time that was spent under gravity forces for working purpose wearing elastic stockings (R2=0.99, P<0.0001. Our experiment demonstrates that elastic stockings may effectively counteract the increased leg volume over time in workers who are exposed to prolonged gravitational gradient. Further longitudinal studies are needed to determine if the above effect could correct one of the major risk factors for the development of chronic venous insufficiency.

Biodynamics of copper oxide nanoparticles and copper ions in an oligochaete - Part II: Subcellular distribution following sediment exposure

Energy Technology Data Exchange (ETDEWEB)

Thit, Amalie, E-mail: athitj@ruc.dk [U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 (United States); Department of Science and Environment, Roskilde University, Universitetsvej 1, Roskilde DK-4000 (Denmark); Ramskov, Tina, E-mail: tramskov@hotmail.com [U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 (United States); Department of Science and Environment, Roskilde University, Universitetsvej 1, Roskilde DK-4000 (Denmark); Croteau, Marie-Noële, E-mail: mcroteau@usgs.gov [Department of Science and Environment, Roskilde University, Universitetsvej 1, Roskilde DK-4000 (Denmark); Selck, Henriette [U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 (United States); Department of Science and Environment, Roskilde University, Universitetsvej 1, Roskilde DK-4000 (Denmark)

2016-11-15

Highlights: • L. variegatus was exposed to sediment spiked with either aqueous Cu or nanoparticulate CuO. • Both aqueous and nanoparticulate Cu were marginally accumulated by L. variegatus. • Elimination of Cu accumulated from both forms was limited. • The subcellular distribution of accumulated Cu varied between Cu forms. • The use of a tracer, greater exposure concentration and duration are recommended. - Abstract: The use and likely incidental release of metal nanoparticles (NPs) is steadily increasing. Despite the increasing amount of published literature on metal NP toxicity in the aquatic environment, very little is known about the biological fate of NPs after sediment exposures. Here, we compare the bioavailability and subcellular distribution of copper oxide (CuO) NPs and aqueous Cu (Cu-Aq) in the sediment-dwelling worm Lumbriculus variegatus. Ten days (d) sediment exposure resulted in marginal Cu bioaccumulation in L. variegatus for both forms of Cu. Bioaccumulation was detected because isotopically enriched {sup 65}Cu was used as a tracer. Neither burrowing behavior or survival was affected by the exposure. Once incorporated into tissue, Cu loss was negligible over 10 d of elimination in clean sediment (Cu elimination rate constants were not different from zero). With the exception of day 10, differences in bioaccumulation and subcellular distribution between Cu forms were either not detectable or marginal. After 10 d of exposure to Cu-Aq, the accumulated Cu was primarily partitioned in the subcellular fraction containing metallothionein-like proteins (MTLP, ≈40%) and cellular debris (CD, ≈30%). Cu concentrations in these fractions were significantly higher than in controls. For worms exposed to CuO NPs for 10 d, most of the accumulated Cu was partitioned in the CD fraction (≈40%), which was the only subcellular fraction where the Cu concentration was significantly higher than for the control group. Our results indicate that L. variegatus

Copper : recession and recovery

International Nuclear Information System (INIS)

Warwick-Ching, T.

2002-01-01

In 2002, the world output for copper will fall for the first time in nearly a decade because of financial pressure and voluntary constraints. Cutbacks at copper mines amount to 760,000 tonnes per year. These cutbacks have occurred mostly in the United States which holds the largest share of high cost mines. This paper discussed recent developments in both copper supply and demand. The United States is unique as both a large consumer and producer of copper. At 1.35 million tonnes, US mine output in 2001 was at its lowest since 1987. The cutbacks in mining in general were described in this paper with particular reference to the huge loss of mining and metallurgical activity in the United States during a prolonged period of low prices in the mid 1980s. The author noted that this period was followed by an exceptional decade when much of the industry rebounded. Only 8 mines closed outright in the United States and a handful in Canada since the recession of the 1980s, but that is partly because mines got bigger and there are fewer small mines in North America. There are only 4 electrolytic refineries and 3 smelters still active in the entire United States, of which 2 are operating at a fraction of capacity. It was noted that only the buoyancy of China prevented a much bigger decline in copper demand on a global scale

Biodynamics of copper oxide nanoparticles and copper ions in an oligochaete: Part I: relative importance of water and sediment as exposure routes

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Ramskov, Tina; Thit, Amalie; Croteau, Marie-Noele; Selck, Henriette

2015-01-01

Copper oxide (CuO) nanoparticles (NPs) are widely used, and likely released into the aquatic environment. Both aqueous (i.e., dissolved Cu) and particulate Cu can be taken up by organisms. However, how exposure routes influence the bioavailability and subsequent toxicity of Cu remains largely unknown. Here, we assess the importance of exposure routes (water and sediment) and Cu forms (aqueous and nanoparticulate) on Cu bioavailability and toxicity to the freshwater oligochaete, Lumbriculus variegatus, a head-down deposit-feeder. We characterize the bioaccumulation dynamics of Cu in L. variegatus across a range of exposure concentrations, covering both realistic and worst-case levels of Cu contamination in the environment. Both aqueous Cu (Cu-Aq; administered as Cu(NO3)2) and nanoparticulate Cu (CuO NPs), whether dispersed in artificial moderately hard freshwater or mixed into sediment, were weakly accumulated by L. variegatus. Once incorporated into tissues, Cu elimination was negligible, i.e., elimination rate constants were in general not different from zero for either exposure route or either Cu form. Toxicity was only observed after waterborne exposure to Cu-Aq at very high concentration (305 µgL-1), where all worms died. There was no relationship between exposure route, Cu form or Cu exposure concentration on either worm survival or growth. Slow feeding rates and low Cu assimilation efficiency (approximately 30%) characterized the uptake of Cu from the sediment for both Cu forms. In nature, L. variegatus is potentially exposed to Cu via both water and sediment. However, sediment progressively becomes the predominant exposure route for Cu in L. variegatus as Cu partitioning to sediment increases.

The Relationship between Posttraumatic and Depressive Symptoms during Prolonged Exposure with and without Cognitive Restructuring for the Treatment of Posttraumatic Stress Disorder

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Aderka, Idan M.; Gillihan, Seth J.; McLean, Carmen P.; Foa, Edna B.

2013-01-01

Objective: In the present study, we examined the relationship between posttraumatic and depressive symptoms during prolonged exposure (PE) treatment with and without cognitive restructuring (CR) for the treatment of posttraumatic stress disorder (PTSD). Method: Female assault survivors (N = 153) with PTSD were randomized to either PE alone or PE…

Critical review: Copper runoff from outdoor copper surfaces at atmospheric conditions.

Science.gov (United States)

Hedberg, Yolanda S; Hedberg, Jonas F; Herting, Gunilla; Goidanich, Sara; Odnevall Wallinder, Inger

2014-01-01

This review on copper runoff dispersed from unsheltered naturally patinated copper used for roofing and facades summarizes and discusses influencing factors, available literature, and predictive models, and the importance of fate and speciation for environmental risk assessment. Copper runoff from outdoor surfaces is predominantly governed by electrochemical and chemical reactions and is highly dependent on given exposure conditions (size, inclination, geometry, degree of sheltering, and orientation), surface parameters (age, patina composition, and thickness), and site-specific environmental conditions (gaseous pollutants, chlorides, rainfall characteristics (amount, intensity, pH), wind direction, temperature, time of wetness, season). The corrosion rate cannot be used to assess the runoff rate. The extent of released copper varies largely between different rain events and is related to dry and wet periods, dry deposition prior to the rain event and prevailing rain and patina characteristics. Interpretation and use of copper runoff data for environmental risk assessment and management need therefore to consider site-specific factors and focus on average data of long-term studies (several years). Risk assessments require furthermore that changes in copper speciation, bioavailability aspects, and potential irreversible retention on solid surfaces are considered, factors that determine the environmental fate of copper runoff from outdoor surfaces.

Dynamics of immediate early gene and neuropeptide gene response to prolonged immobilization stress: evidence against a critical role of the termination of exposure to the stressor.

Science.gov (United States)

Trnecková, Lenka; Rotllant, David; Klenerová, Vera; Hynie, Sixtus; Armario, Antonio

2007-02-01

Stress-induced expression of immediate early genes (IEGs) appears to be transient even if the exposure to the stressor persists. However, there are some exceptions which suggest that particular characteristics of stressors can affect the dynamics of IEG expression. We studied in selected telencephalic, diencephalic and brainstem regions the mRNA levels of two clearly distinct IEGs (c-fos and arc) during prolonged exposure to a severe stressor such as immobilization (IMO) and after releasing the rats from the situation. Although regional differences were observed with the two IEGs, overall, c-fos mRNA levels progressively declined over the course of 4 h of continuous exposure to IMO, whereas arc mRNA levels were maintained at high levels in the brain regions that express this gene under stress (telencephalon). Levels of CRF hnRNA in the hypothalamus paraventricular nucleus only slightly declined during prolonged exposure to IMO. Surprisingly, termination of exposure to IMO did not modify CRF gene expression in the paraventricular nucleus or the pattern of IEGs expression, with the exception of c-fos in the lateral septum. Thus, putative signals associated to the termination of exposure to IMO were unable to modify either IEG expression in most brain areas or CRF gene expression in the paraventricular nucleus.

Self-reduction of a copper complex MOD ink for inkjet printing conductive patterns on plastics.

Science.gov (United States)

Farraj, Yousef; Grouchko, Michael; Magdassi, Shlomo

2015-01-31

Highly conductive copper patterns on low-cost flexible substrates are obtained by inkjet printing a metal complex based ink. Upon heating the ink, the soluble complex, which is composed of copper formate and 2-amino-2-methyl-1-propanol, decomposes under nitrogen at 140 °C and is converted to pure metallic copper. The decomposition process of the complex is investigated and a suggested mechanism is presented. The ink is stable in air for prolonged periods, with no sedimentation or oxidation problems, which are usually encountered in copper nanoparticle based inks.

Psidium guajava and Piper betle leaf extracts prolong vase life of cut carnation (Dianthus caryophyllus) flowers.

Science.gov (United States)

Rahman, M M; Ahmad, S H; Lgu, K S

2012-01-01

The effect of leaf extracts of Psidium guajava and Piper betle on prolonging vase life of cut carnation flowers was studied. "Carola" and "Pallas Orange" carnation flowers, at bud stage, were pulsed 24 hours with a floral preservative. Then, flowers were placed in a vase solution containing sprite and a "germicide" (leaf extracts of P. guajava and P. betle, 8-HQC, or a copper coin). Flowers treated with 8-HQC, copper coin, and leaf extracts had longer vase life, larger flower diameter, and higher rate of water uptake compared to control (tap water). The leaf extracts of P. guajava and P. betle showed highest antibacterial and antifungal activities compared to the other treatments. Both showed similar effects on flower quality as the synthetic germicide, 8-HQC. Therefore, these extracts are likely natural germicides to prolong vase life of cut flowers.

Effect of Copper on Fatty-Acid Composition and Peroxidation of Lipids in the Roots of Copper Tolerant and Sensitive Silene-Cucubalus.

NARCIS (Netherlands)

De Vos, C.H.R.; TenBookum, W.M.; Vooijs, R.; Schat, H.; De Kok, L.J.

1993-01-01

The effect of high copper exposure in vivo on the lipid and fatty acid composition and lipid peroxidation was studied in the roots of plants from one copper sensitive and two copper tolerant genotypes of Silene cucubalus. At 0.5 muM Cu (control treatment) the compositions of lipids and fatty acids

Comparative analysis of the transcriptome responses of zebrafish embryos after exposure to low concentrations of cadmium, cobalt and copper.

Science.gov (United States)

Sonnack, Laura; Klawonn, Thorsten; Kriehuber, Ralf; Hollert, Henner; Schäfers, Christoph; Fenske, Martina

2018-03-01

Metal toxicity is a global environmental challenge. Fish are particularly prone to metal exposure, which can be lethal or cause sublethal physiological impairments. The objective of this study was to investigate how adverse effects of chronic exposure to non-toxic levels of essential and non-essential metals in early life stage zebrafish may be explained by changes in the transcriptome. We therefore studied the effects of three different metals at low concentrations in zebrafish embryos by transcriptomics analysis. The study design compared exposure effects caused by different metals at different developmental stages (pre-hatch and post-hatch). Wild-type embryos were exposed to solutions of low concentrations of copper (CuSO 4 ), cadmium (CdCl 2 ) and cobalt (CoSO 4 ) until 96h post-fertilization (hpf) and microarray experiments were carried out to determine transcriptome profiles at 48 and 96hpf. We found that the toxic metal cadmium affected the expression of more genes at 96hpf than 48hpf. The opposite effect was observed for the essential metals cobalt and copper, which also showed enrichment of different GO terms. Genes involved in neuromast and motor neuron development were significantly enriched, agreeing with our previous results showing motor neuron and neuromast damage in the embryos. Our data provide evidence that the response of the transcriptome of fish embryos to metal exposure differs for essential and non-essential metals. Copyright © 2017 Elsevier Inc. All rights reserved.

Hsp27, Hsp70, and metallothionein in MDCK and LLC-PK1 renal epithelial cells: effects of prolonged exposure to cadmium

International Nuclear Information System (INIS)

Bonham, Rita T.; Fine, Michael R.; Pollock, Fiona M.; Shelden, Eric A.

2003-01-01

Cadmium is a widely distributed industrial and environmental toxin. The principal target organ of chronic sublethal cadmium exposure is the kidney. In renal epithelial cells, acute high-dose cadmium exposure induces differential expression of proteins, including heat shock proteins. However, few studies have examined heat shock protein expression in cells after prolonged exposure to cadmium at sublethal concentrations. Here, we assayed total cell protein, neutral red uptake, cell death, and levels of metallothionein and heat shock proteins Hsp27 and inducible Hsp70 in cultures of MDCK and LLC-PK1 renal epithelial cells treated with cadmium for 3 days. Treatment with cadmium at concentrations equal to or greater than 10 μM (LLC-PK1) or 25 μM (MDCK) reduced measures of cell vitality and induced cell death. However, a concentration-dependent increase in Hsp27 was detected in both cell types treated with as little as 5 μM cadmium. Accumulation of Hsp70 was correlated only with cadmium treatment at concentrations also causing cell death. Metallothionein was maximally detected in cells treated with cadmium at concentrations that did not reduce cell vitality, and further increases were not detected at greater concentrations. These results reveal that heat shock proteins accumulate in renal epithelial cells during prolonged cadmium exposure, that cadmium induces differential expression of heat shock protein in epithelial cells, and that protein expression patterns in epithelial cells are specific to the cadmium concentration and degree of cellular injury. A potential role for Hsp27 in the cellular response to sublethal cadmium-induced injury is also implicated by our results

Effects of copper nanoparticle exposure on host defense in a murine pulmonary infection model

Directory of Open Access Journals (Sweden)

Grassian Vicki H

2011-09-01

Full Text Available Abstract Background Human exposure to nanoparticles (NPs and environmental bacteria can occur simultaneously. NPs induce inflammatory responses and oxidative stress but may also have immune-suppressive effects, impairing macrophage function and altering epithelial barrier functions. The purpose of this study was to assess the potential pulmonary effects of inhalation and instillation exposure to copper (Cu NPs using a model of lung inflammation and host defense. Methods We used Klebsiella pneumoniae (K.p. in a murine lung infection model to determine if pulmonary bacterial clearance is enhanced or impaired by Cu NP exposure. Two different exposure modes were tested: sub-acute inhalation (4 hr/day, 5 d/week for 2 weeks, 3.5 mg/m3 and intratracheal instillation (24 hr post-exposure, 3, 35, and 100 μg/mouse. Pulmonary responses were evaluated by lung histopathology plus measurement of differential cell counts, total protein, lactate dehydrogenase (LDH activity, and inflammatory cytokines in bronchoalveolar lavage (BAL fluid. Results Cu NP exposure induced inflammatory responses with increased recruitment of total cells and neutrophils to the lungs as well as increased total protein and LDH activity in BAL fluid. Both inhalation and instillation exposure to Cu NPs significantly decreased the pulmonary clearance of K.p.-exposed mice measured 24 hr after bacterial infection following Cu NP exposure versus sham-exposed mice also challenged with K.p (1.4 × 105 bacteria/mouse. Conclusions Cu NP exposure impaired host defense against bacterial lung infections and induced a dose-dependent decrease in bacterial clearance in which even our lowest dose demonstrated significantly lower clearance than observed in sham-exposed mice. Thus, exposure to Cu NPs may increase the risk of pulmonary infection.

Effect of in vitro exposure to cadmium and copper on sea bass blood cells

Directory of Open Access Journals (Sweden)

Vincenzo Arizza

2010-01-01

Full Text Available Blood cells freshly collected from sea bass (Dicentrarchus labrax were exposed in vitro to different concentrations of cadmium (Cd and copper (Cu at 10-7 M, 10-5 M, 10-3 M, and exam- ined for neutral red retention capacity and for cell vitality with MTT assay. A relationship between heavy metal exposure and alteration in responses of blood cells in a dose-time-dependent was found. Our results showed that fish blood cells may constitute an interesting biological model for experimen- tal and applied toxicology, especially in the case of environmental pollution.

Changes in CR-39 proton sensitivity due to prolonged exposure to high vacuums relevant to the National Ignition Facility and OMEGA.

Science.gov (United States)

Manuel, M J-E; Rosenberg, M J; Sinenian, N; Rinderknecht, H; Zylstra, A B; Séguin, F H; Frenje, J; Li, C K; Petrasso, R D

2011-09-01

When used at facilities like OMEGA and the NIF, CR-39 is exposed to high vacuum environments before and after irradiation by charged particles and neutrons. Using an electrostatic linear accelerator at MIT, studies have been conducted to investigate the effects of high vacuum exposure on the sensitivity of CR-39 to fusion protons in the ~1-9 MeV energy range. High vacuum conditions, of order 10(-5) Torr, experienced by CR-39 samples at these facilities were emulated. It is shown that vacuum exposure times longer than ~16 h before proton irradiation result in a decrease in proton sensitivity, whereas no effect was observed for up to 67 h of vacuum exposure after proton irradiation. CR-39 sensitivity curves are presented for samples with prolonged exposure to high vacuum before and after proton irradiation. © 2011 American Institute of Physics

Psidium guajava and Piper betle Leaf Extracts Prolong Vase Life of Cut Carnation (Dianthus caryophyllus Flowers

Directory of Open Access Journals (Sweden)

M. M. Rahman

2012-01-01

Full Text Available The effect of leaf extracts of Psidium guajava and Piper betle on prolonging vase life of cut carnation flowers was studied. “Carola” and “Pallas Orange” carnation flowers, at bud stage, were pulsed 24 hours with a floral preservative. Then, flowers were placed in a vase solution containing sprite and a “germicide” (leaf extracts of P. guajava and P. betle, 8-HQC, or a copper coin. Flowers treated with 8-HQC, copper coin, and leaf extracts had longer vase life, larger flower diameter, and higher rate of water uptake compared to control (tap water. The leaf extracts of P. guajava and P. betle showed highest antibacterial and antifungal activities compared to the other treatments. Both showed similar effects on flower quality as the synthetic germicide, 8-HQC. Therefore, these extracts are likely natural germicides to prolong vase life of cut flowers.

Psidium guajava and Piper betle Leaf Extracts Prolong Vase Life of Cut Carnation (Dianthus caryophyllus) Flowers

OpenAIRE

Rahman, M. M.; Ahmad, S. H.; Lgu, K. S.

2012-01-01

The effect of leaf extracts of Psidium guajava and Piper betle on prolonging vase life of cut carnation flowers was studied. “Carola” and “Pallas Orange” carnation flowers, at bud stage, were pulsed 24 hours with a floral preservative. Then, flowers were placed in a vase solution containing sprite and a “germicide” (leaf extracts of P. guajava and P. betle, 8-HQC, or a copper coin). Flowers treated with 8-HQC, copper coin, and leaf extracts had longer vase life, larger flower diameter, and hi...

The peculiarity of aerobic energy supply of rat tissues of different age upon prolonged ionizing and thermal exposure

International Nuclear Information System (INIS)

Tsyhun, G.F.

1998-01-01

Energy-producing functions of brain, myocardium, and hepatic mitochondria in mature and immature rats in remote period after prolonged ionizing X-ray at total dose 12,9 m C/kg and thermal exposure (4 hours, 37 degrees centigrade, 25 times) were studied. Dehydrogenase activities (pyruvate-, isocitrate-, 2-oxy glutarate-, succinate- and malate dehydrogenases) were reduced in mitochondria of different tissues of adult rats and it was especially considerable after combined influence. A higher resistance of young rats, as compared to adult ones, to combined radiation-thermal treatments was established

Copper stabilization in beneficial use of waterworks sludge and copper-laden electroplating sludge for ceramic materials.

Science.gov (United States)

Tang, Yuanyuan; Chan, Siu-Wai; Shih, Kaimin

2014-06-01

A promising strategy for effectively incorporating metal-containing waste materials into a variety of ceramic products was devised in this study. Elemental analysis confirmed that copper was the predominant metal component in the collected electroplating sludge, and aluminum was the predominant constituent of waterworks sludge collected in Hong Kong. The use of waterworks sludge as an aluminum-rich precursor material to facilitate copper stabilization under thermal conditions provides a promising waste-to-resource strategy. When sintering the mixture of copper sludge and the 900 °C calcined waterworks sludge, the CuAl2O4 spinel phase was first detected at 650 °C and became the predominant product phase at temperatures higher than 850 °C. Quantification of the XRD pattern using the Rietveld refinement method revealed that the weight of the CuAl2O4 spinel phase reached over 50% at 850 °C. The strong signals of the CuAl2O4 phase continued until the temperature reached 1150 °C, and further sintering initiated the generation of the other copper-hosting phases (CuAlO2, Cu2O, and CuO). The copper stabilization effect was evaluated by the copper leachability of the CuAl2O4 and CuO via the prolonged leaching experiments at a pH value of 4.9. The leaching results showed that the CuAl2O4 phase was superior to the CuAlO2 and CuO phases for immobilizing hazardous copper over longer leaching periods. The findings clearly indicate that spinel formation is the most crucial metal stabilization mechanism when sintering multiphase copper sludge with aluminum-rich waterworks sludge, and suggest a promising and reliable technique for reusing both types of sludge waste for ceramic materials. Copyright © 2013 Elsevier Ltd. All rights reserved.

Acute and chronic sensitivity of white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) to cadmium, copper, lead, or zinc in laboratory water-only exposures

Science.gov (United States)

Ingersoll, Christopher G.; Contributions by Wang, Ning; Calfee, Robin D.; Beahan, Erinn; Brumbaugh, William G.; Dorman, Rebecca A.; Hardesty, Doug K.; Kunz, James L.; Little, Edward E.; Mebane, Christopher A.; Puglis, Holly J.

2014-01-01

White sturgeon (Acipenser transmontanus) are experiencing poor recruitment in the trans boundary reach of the upper Columbia River in eastern Washington State. Limited toxicity data indicated that early life stages of white sturgeon are sensitive to metals. In acute 4-day (d) exposures with larval white sturgeon, previous studies have reported that the 4-day median lethal concentrations (LC50) based on biotic ligand model (BLM) normalization for copper were below the U.S. Environmental Protection Agency national recommended acute water-quality criterion. In previously published chronic 66-d exposures starting with newly fertilized eggs of white sturgeon, 20-percent lethal effect concentrations (LC20s) for copper, cadmium, or zinc generally were within a factor of two of the chronic values of the most sensitive fish species in the databases of the U.S. Environmental Protection Agency water-quality criteria (WQC) for the three metals. However, there were some uncertainties in the chronic exposures previously performed with white sturgeon, including (1) low control survival (37 percent), (2) more control fish tested in each replicate compared to other treatments, (3) limited replication of treatments (n=2), (4) lack of reported growth data (such as dry weight), and (5) wide dilution factors for exposure concentrations (6- to 8-fold dilutions). The U.S. Environmental Protection Agency concluded that additional studies are needed to generate more toxicity data to better define lethal and sublethal toxicity thresholds for metals for white sturgeon. The objective of the study was to further evaluate the acute and chronic toxicity of cadmium, copper, lead, or zinc to early life stages of white sturgeon in water-only exposures. Toxicity tests also were performed with commonly tested rainbow trout (Oncorhynchus mykiss) under similar test conditions to determine the relative sensitivity between white sturgeon and rainbow trout to these metals. Toxicity data generated from

Alantolactone Improves Prolonged Exposure of Interleukin-6-Induced Skeletal Muscle Inflammation Associated Glucose Intolerance and Insulin Resistance

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Minjee Kim

2017-06-01

Full Text Available The pro-inflammatory cytokine, Interleukin-6 (IL-6, has been proposed to be one of the mediators that link chronic inflammation to glucose intolerance and insulin resistance. Many studies have demonstrated the effects of IL-6 on insulin action in the skeletal muscle. However, few studies have investigated the effect of long-term treatment of IL-6, leading to glucose intolerance and insulin resistance. In the present study, we observed protective effects of alantolactone, a sesquiterpene lactone isolated from Inula helenium against glucose intolerance and insulin resistance induced by prolonged exposure of IL-6. Alantolactone has been reported to have anti-inflammatory and anti-cancer effects through IL-6-induced signal transducer and activator of transcription 3 (STAT3 signaling pathway. The relationship between IL-6 exposure and expression of toll-like receptor 4 (TLR4, involved in inflammation in the skeletal muscle, and the underlying mechanisms were investigated. We observed maximum dysregulation of glucose uptake after 40 ng/ml IL-6 induction for 24 h in L6 myotubes. Prolonged IL-6 exposure suppressed glucose uptake regulating alpha serine/threonine-protein kinase (AKT phosphorylation; however, pretreatment with alantolactone activated AKT phosphorylation and improved glucose uptake. Alantolactone also attenuated IL-6-stimulated STAT3 phosphorylation, followed by an increase in expression of negative regulator suppressor of cytokine signaling 3 (SOCS3. Furthermore, IL-6-induced expression of pathogen recognition receptor, TLR4, was also suppressed by alantolactone pretreatment. Post-silencing of STAT3 using siRNA approach, IL-6-stimulated siRNA-STAT3 improved glucose uptake and suppressed TLR4 gene expression. Taken together, we propose that, as a STAT3 inhibitor, alantolactone, improves glucose regulation in the skeletal muscle by inhibiting IL-6-induced STAT3-SOCS3 signaling followed by inhibition of the TLR4 gene expression. Therefore

Glycyrrhizin Treatment Facilitates Extinction of Conditioned Fear Responses After a Single Prolonged Stress Exposure in Rats

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Shuhua Lai

2018-03-01

Full Text Available Background/Aims: Impaired fear memory extinction is widely considered a key mechanism of post-traumatic stress disorder (PTSD. Recent studies have suggested that neuroinflammation after a single prolonged stress (SPS exposure may play a critical role in the impaired fear memory extinction. Studies have shown that high mobility group box chromosomal protein 1 (HMGB-1 is critically involved in neuroinflammation. However, the role of HMGB-1 underlying the development of impairment of fear memory extinction is still not known. Methods: Thus, we examined the levels of HMGB-1 in the basolateral amygdala (BLA following SPS using Western blot and evaluated the levels of microglia and astrocytes activation in the BLA after SPS using immunohistochemical staining. We then examined the effects of pre-SPS intra-BLA administration of glycyrrhizin, an HMGB1 inhibitor, or LPS-RS, a competitive TLR4 antagonist, on subsequent post-SPS fear extinction. Results: We found that SPS treatment prolonged the extinction of contextual fear memory after the SPS. The impairment of SPS-induced extinction of contextual fear memory was associated with increased HMGB1 and Toll-like receptor 4 (TLR4 levels in the BLA. Additionally, the impairment of SPS-induced extinction of contextual fear memory was associated with increased activation of microglia and astrocyte in the BLA. Intra-BLA administrations of glycyrrhizin (HMGB-1 inhibitor or LPS-RS (TLR4 antagonist can prevent the development of SPS-induced fear extinction impairment. Conclusion: Taken together, these results suggested that SPS treatment may not only produce short term effects on the HMGB1/TLR4-mediated pro-inflammation, but alter the response of microglia and astrocytes to the exposure to fear associated contextual stimuli.

Glycyrrhizin Treatment Facilitates Extinction of Conditioned Fear Responses After a Single Prolonged Stress Exposure in Rats.

Science.gov (United States)

Lai, Shuhua; Wu, Gangwei; Jiang, Zhixian

2018-01-01

Impaired fear memory extinction is widely considered a key mechanism of post-traumatic stress disorder (PTSD). Recent studies have suggested that neuroinflammation after a single prolonged stress (SPS) exposure may play a critical role in the impaired fear memory extinction. Studies have shown that high mobility group box chromosomal protein 1 (HMGB-1) is critically involved in neuroinflammation. However, the role of HMGB-1 underlying the development of impairment of fear memory extinction is still not known. Thus, we examined the levels of HMGB-1 in the basolateral amygdala (BLA) following SPS using Western blot and evaluated the levels of microglia and astrocytes activation in the BLA after SPS using immunohistochemical staining. We then examined the effects of pre-SPS intra-BLA administration of glycyrrhizin, an HMGB1 inhibitor, or LPS-RS, a competitive TLR4 antagonist, on subsequent post-SPS fear extinction. We found that SPS treatment prolonged the extinction of contextual fear memory after the SPS. The impairment of SPS-induced extinction of contextual fear memory was associated with increased HMGB1 and Toll-like receptor 4 (TLR4) levels in the BLA. Additionally, the impairment of SPS-induced extinction of contextual fear memory was associated with increased activation of microglia and astrocyte in the BLA. Intra-BLA administrations of glycyrrhizin (HMGB-1 inhibitor) or LPS-RS (TLR4 antagonist) can prevent the development of SPS-induced fear extinction impairment. Taken together, these results suggested that SPS treatment may not only produce short term effects on the HMGB1/TLR4-mediated pro-inflammation, but alter the response of microglia and astrocytes to the exposure to fear associated contextual stimuli. © 2018 The Author(s). Published by S. Karger AG, Basel.

Copper imbalances in ruminants and humans: unexpected common ground.

Science.gov (United States)

Suttle, Neville F

2012-09-01

Ruminants are more vulnerable to copper deficiency than humans because rumen sulfide generation lowers copper availability from forage, increasing the risk of conditions such as swayback in lambs. Molybdenum-rich pastures promote thiomolybdate (TM) synthesis and formation of unabsorbable Cu-TM complexes, turning risk to clinical reality (hypocuprosis). Selection pressures created ruminant species with tolerance of deficiency but vulnerability to copper toxicity in alien environments, such as specific pathogen-free units. By contrast, cases of copper imbalance in humans seemed confined to rare genetic aberrations of copper metabolism. Recent descriptions of human swayback and the exploratory use of TM for the treatment of Wilson's disease, tumor growth, inflammatory diseases, and Alzheimer's disease have created unexpected common ground. The incidence of pre-hemolytic copper poisoning in specific pathogen-free lambs was reduced by an infection with Mycobacterium avium that left them more responsive to treatment with TM but vulnerable to long-term copper depletion. Copper requirements in ruminants and humans may need an extra allowance for the "copper cost" of immunity to infection. Residual cuproenzyme inhibition in TM-treated lambs and anomalies in plasma copper composition that appeared to depend on liver copper status raise this question "can chelating capacity be harnessed without inducing copper-deficiency in ruminants or humans?" A model of equilibria between exogenous (TM) and endogenous chelators (e.g., albumin, metallothionein) is used to predict risk of exposure and hypocuprosis; although risk of natural exposure in humans is remote, vulnerability to TM-induced copper deficiency may be high. Biomarkers of TM impact are needed, and copper chaperones for inhibited cuproenzymes are prime candidates.

Effects of copper on Gammerus pseudolimneus, Physa integra, and Campeloma decisum in soft water

Energy Technology Data Exchange (ETDEWEB)

Arthur, J W; Leonard, E N

1970-01-01

Three invertebrate species were subjected to acute (96-hr), followed by long-term (6-week) copper exposured under continuous-flow bioassay conditions. Survival, growth, reproduction, and feeding were the responses used for measuring toxicant effects. The average 96-hr median tolerance limits (tlm) values for Campeloma decisum, Physa integra, and Gammarus pseudolimnaeus were 1.7, 0.039, and 0.020 micrograms/liter total copper, respectively. The total copper concentration having no effect after 6 weeks exposure for all three species was between 8.0 and 14.8 micrograms/liter. The newly hatched amphipods obtained from the second 6-week study were exposed to copper for 9 additional weeks, and grew to the adult age only in copper concentrations <4.6 micrograms/liter. After 5 weeks exposure to a water system, survival of newly hatched Gammarus was markedly reduced when copper concentrations were between 12.9 and 6.2 micrograms/liter.

Coexistence of Ureaplasma and chorioamnionitis is associated with prolonged mechanical ventilation.

Science.gov (United States)

Jung, Euiseok; Choi, Chang Won; Kim, Su Yeong; Sung, Tae-Jung; Kim, Haeryoung; Park, Kyoung Un; Kim, Han-Suk; Kim, Beyong Il; Choi, Jung-Hwan

2017-01-01

Both histologic chorioamnionitis (HCAM) and Ureaplasma infection are considered important contributors to perinatal lung injury. We tested the hypothesis that coexistence of maternal HCAM and perinatal Ureaplasma exposure increases the risk of prolonged mechanical ventilation in extremely low-birthweight (ELBW) infants. A retrospective cohort study was carried out of all ELBW infants born between January 2008 and December 2013 at a single academic center. Placental pathology and gastric fluid Ureaplasma data were available for all infants. Culture and polymerase chain reaction were used to detect Ureaplasma in gastric fluid. Prolonged mechanical ventilation was defined as mechanical ventilation that began within 28 days after birth and continued. Of 111 ELBW infants enrolled, 84 survived beyond 36 weeks of postmenstrual age (PMA) and were included in the analysis. Eighteen infants (21.4%) had both HCAM and Ureaplasma exposure. Seven infants (8.3%) required mechanical ventilation beyond 36 weeks of PMA. Coexistence of HCAM and Ureaplasma in gastric fluid was significantly associated with prolonged mechanical ventilation after adjustment for gestational age, sex, mode of delivery, and use of macrolide antibiotics (OR, 8.7; 95%CI: 1.1-67.2). Coexistence of maternal HCAM and perinatal Ureaplasma exposure significantly increases the risk of prolonged mechanical ventilation in ELBW infants. © 2016 Japan Pediatric Society.

Biodynamics of copper oxide nanoparticles and copper ions in an oligochaete – Part I: Relative importance of water and sediment as exposure routes

Energy Technology Data Exchange (ETDEWEB)

Ramskov, Tina, E-mail: tramskov@hotmail.com [Department of Environmental, Social and Spatial Change, Roskilde University, PO Box 260, Universitetsvej 1, DK-4000 Roskilde (Denmark); US Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 (United States); Thit, Amalie, E-mail: athitj@ruc.dk [Department of Environmental, Social and Spatial Change, Roskilde University, PO Box 260, Universitetsvej 1, DK-4000 Roskilde (Denmark); Croteau, Marie-Noële, E-mail: mcroteau@usgs.gov [US Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 (United States); Selck, Henriette, E-mail: selck@ruc.dk [Department of Environmental, Social and Spatial Change, Roskilde University, PO Box 260, Universitetsvej 1, DK-4000 Roskilde (Denmark); US Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 (United States)

2015-07-15

Highlights: • Both aqueous and nanoparticulate Cu forms are available for uptake by L. variegatus. • Cu accumulation is driven by both water and sediment uptake. • Cu form weakly influences Cu biodynamics in L. variegatus. • Food ingestion rate is a sensitive endpoint for dietborne Cu exposure. • Stable isotope tracers allow detecting accumulation after environmentally relevant exposures. - Abstract: Copper oxide (CuO) nanoparticles (NPs) are widely used, and likely released into the aquatic environment. Both aqueous (i.e., dissolved Cu) and particulate Cu can be taken up by organisms. However, how exposure routes influence the bioavailability and subsequent toxicity of Cu remains largely unknown. Here, we assess the importance of exposure routes (water and sediment) and Cu forms (aqueous and nanoparticulate) on Cu bioavailability and toxicity to the freshwater oligochaete, Lumbriculus variegatus, a head-down deposit-feeder. We characterize the bioaccumulation dynamics of Cu in L. variegatus across a range of exposure concentrations, covering both realistic and worst-case levels of Cu contamination in the environment. Both aqueous Cu (Cu-Aq; administered as Cu(NO{sub 3}){sub 2}) and nanoparticulate Cu (CuO NPs), whether dispersed in artificial moderately hard freshwater or mixed into sediment, were weakly accumulated by L. variegatus. Once incorporated into tissues, Cu elimination was negligible, i.e., elimination rate constants were in general not different from zero for either exposure route or either Cu form. Toxicity was only observed after waterborne exposure to Cu-Aq at very high concentration (305 μg L{sup −1}), where all worms died. There was no relationship between exposure route, Cu form or Cu exposure concentration on either worm survival or growth. Slow feeding rates and low Cu assimilation efficiency (approximately 30%) characterized the uptake of Cu from the sediment for both Cu forms. In nature, L. variegatus is potentially exposed to Cu

Surface-rain interactions: differences in copper runoff for copper sheet of different inclination, orientation, and atmospheric exposure conditions.

Science.gov (United States)

Hedberg, Yolanda S; Goidanich, Sara; Herting, Gunilla; Wallinder, Inger Odnevall

2015-01-01

Predictions of the diffuse dispersion of metals from outdoor constructions such as roofs and facades are necessary for environmental risk assessment and management. An existing predictive model has been compared with measured data of copper runoff from copper sheets exposed at four different inclinations facing four orientations at two different urban sites (Stockholm, Sweden, and Milan, Italy) during a 4-year period. Its applicability has also been investigated for copper sheet exposed at two marine sites(Cadiz, Spain, for 5 years, and Brest, France, for 9 years). Generally the model can be used for all given conditions. However, vertical surfaces should be considered as surfaces inclined 60-80 due to wind driven effects. The most important parameters that influence copper runoff, and not already included in the model, are the wind and rain characteristics that influence the actual rainfall volume impinging the surface of interest.

Monitoring losses of copper based wood preservatives in the Thames estuary

International Nuclear Information System (INIS)

Hingston, J.A.; Murphy, R.J.; Lester, J.N.

2006-01-01

Field trials were conducted at two sites in the Thames estuary to monitor losses of copper, chromium and arsenic from wood preservative treated timbers of varying sizes and treatment regimes. Results indicated that leaching tests conducted under standard laboratory conditions might overestimate losses compared to losses resulting from real environmental exposures. Amine copper treated wood was noted to leach higher levels of copper compared to chromated copper arsenate treated wood, and was therefore considered an inappropriate replacement biocide for fresh and marine construction purposes on this basis. Increases in copper concentrations in the outer sections of amine copper treated posts may have represented re-distribution of this component in this timber. No accumulation of metals was found in sediments surrounding field trial posts. - Wood preservative field trials in the UK indicate that standard laboratory tests overestimate losses compared to those resulting from real environmental exposures

Monitoring losses of copper based wood preservatives in the Thames estuary

Energy Technology Data Exchange (ETDEWEB)

Hingston, J.A. [Environmental Processes and Water Technology Research Group, Department of Environmental Science and Technology, Faculty of Life Sciences, Imperial College, London SW7 2AZ (United Kingdom)]. E-mail: james.hingston@psd.defra.gsi.gov.uk; Murphy, R.J. [Department of Biology, Imperial College, London SW7 2AZ (United Kingdom); Lester, J.N. [School of Water Sciences, Cranfield University, Cranfield, Bedfordshire, MK43 0AL (United Kingdom)

2006-09-15

Field trials were conducted at two sites in the Thames estuary to monitor losses of copper, chromium and arsenic from wood preservative treated timbers of varying sizes and treatment regimes. Results indicated that leaching tests conducted under standard laboratory conditions might overestimate losses compared to losses resulting from real environmental exposures. Amine copper treated wood was noted to leach higher levels of copper compared to chromated copper arsenate treated wood, and was therefore considered an inappropriate replacement biocide for fresh and marine construction purposes on this basis. Increases in copper concentrations in the outer sections of amine copper treated posts may have represented re-distribution of this component in this timber. No accumulation of metals was found in sediments surrounding field trial posts. - Wood preservative field trials in the UK indicate that standard laboratory tests overestimate losses compared to those resulting from real environmental exposures.

Native copper in Permian Mudstones from South Devon: A natural analogue of copper canisters for high-level radioactive waste

International Nuclear Information System (INIS)

Milodowski, A.E.; Styles, M.T.; Werme, L.; Oversby, V.M.

2001-01-01

Native copper (>99.9% Cu) sheets associated with complex uraniferous and vanadiferous concretions in Upper Permian Mudstones from south Devon (United Kingdom) have been studied as a 'natural analogue' for copper canisters designed to be used in the isolation of spent fuel and high-level radioactive wastes (HLW) for deep geological disposal. Detailed analysis demonstrates that the copper formed before the mudstones were compacted. The copper displays complex corrosion and alteration. The earliest alteration was to copper oxides, followed sequentially by the formation of copper arsenides, nickel arsenide and copper sulphide, and finally nickel arsenide accompanied by nickel-copper arsenide, copper arsenide and uranium silicates. Petrographic observations demonstrate that these alteration products also formed prior to compaction. Consideration of the published history for the region indicates that maximum compaction of the rocks will have occurred by at least the Lower Jurassic (i.e. over 176 Ma ago). Since that time the copper sheets have remained isolated by the compacted mudstones and were unaffected by further corrosion until uplift and exposure to present-day surface weathering

Long-term adaptation of Daphnia to toxic environment in Lake Orta: the effects of short-term exposure to copper and acidification

Directory of Open Access Journals (Sweden)

Marina MANCA

2010-08-01

Full Text Available Because of its 80-year history of heavy pollution and re-colonization, Lake Orta provides a good opportunity for investigating the response of zooplankton organisms to heavy metals and acidification as well as the mechanisms involved. After the recent establishment of Daphnia galeata Sars, and the detection of an extremely low clonal diversity of Lake Orta population, we carried out a study to investigate the lethal tolerance to ionic copper, as well as to acidity, and the impact of newborn Daphnia exposure to sublethal concentrations of copper for their later development and reproduction. We conducted acute toxicity tests to estimate the EC50 for ionic copper and tolerance to low pH, as well as life table experiments. Tolerance to ionic copper was high, three times that reported in literature. An increased mortality soon after exposure to low pH confirmed a high sensitivity to acidity and explained the success of the species in Lake Orta only after pH recovery. An analysis of reproductive and demographic parameters revealed that D. galeata Sars was stressed at concentrations of ionic copper only twice higher than those presently recorded in the lake (i.e., ca 3 μg L-1. An increased cumulative number of eggs produced by each female were in fact counterbalanced by an increasing abortion rate, which resulted in an unaltered or lower intrinsic rate of population increase. Our results are likely due to the strong selective pressure, more than physiological processes (acclimation, in a polluted area in which only specific adapted clones are able to grow, confirming the results previously obtained on Lake Orta's D. obtusa Kurz population. The reproductive response and the relatively low within treatment variability suggest that clone specificity, rather than physiological acclimation, was the driving force. The low variability confirmed results previously obtained from life tables experiments on Lake Orta's D. obtusa clone. Overall, our results

Acute and sub-lethal exposure to copper oxide nanoparticles causes oxidative stress and teratogenicity in zebrafish embryos.

Science.gov (United States)

Ganesan, Santhanamari; Anaimalai Thirumurthi, Naveenkumar; Raghunath, Azhwar; Vijayakumar, Savitha; Perumal, Ekambaram

2016-04-01

Nano-copper oxides are a versatile inorganic material. As a result of their versatility, the immense applications and usage end up in the environment causing a concern for the lifespan of various beings. The ambiguities surround globally on the toxic effects of copper oxide nanoparticles (CuO-NPs). Hence, the present study endeavored to study the sub-lethal acute exposure effects on the developing zebrafish embryos. The 48 hpf LC50 value was about 64 ppm. Therefore, we have chosen the sub-lethal dose of 40 and 60 ppm for the study. Accumulation of CuO-NPs was evidenced from the SEM-EDS and AAS analyzes. The alterations in the AChE and Na(+)/K(+)-ATPase activities disrupted the development process. An increment in the levels of oxidants with a concomitant decrease in the antioxidant enzymes confirmed the induction of oxidative stress. Oxidative stress triggered apoptosis in the exposed embryos. Developmental anomalies were observed with CuO-NPs exposure in addition to oxidative stress in the developing embryos. Decreased heart rate and hatching delay hindered the normal developmental processes. Our work has offered valuable data on the connection between oxidative stress and teratogenicity leading to lethality caused by CuO-NPs. A further molecular mechanism unraveling the uncharted connection between oxidative stress and teratogenicity will aid in the safe use of CuO-NPs. Copyright © 2015 John Wiley & Sons, Ltd.

Biodynamics of copper oxide nanoparticles and copper ions in an oligochaete

DEFF Research Database (Denmark)

Thit, Amalie; Ramskov, Tina; Croteau, Marie-Noële Croteau

2016-01-01

the bioavailability and subcellular distribution of copper oxide (CuO) NPs and aqueous Cu (Cu-Aq) in the sediment-dwelling worm Lumbriculus variegatus. Ten days (d) sediment exposure resulted in marginal Cu bioaccumulation in L. variegatus for both forms of Cu. Bioaccumulation was detected because isotopically...

The effects of silver ions on copper metabolism in rats.

Science.gov (United States)

Ilyechova, E Yu; Saveliev, A N; Skvortsov, A N; Babich, P S; Zatulovskaia, Yu A; Pliss, M G; Korzhevskii, D E; Tsymbalenko, N V; Puchkova, L V

2014-10-01

The influence of short and prolonged diet containing silver ions (Ag-diet) on copper metabolism was studied. Two groups of animals were used: one group of adult rats received a Ag-diet for one month (Ag-A1) and another group received a Ag-diet for 6 months from birth (Ag-N6). In Ag-A1 rats, the Ag-diet caused a dramatic decrease of copper status indexes that was manifested as ceruloplasmin-associated copper deficiency. In Ag-N6 rats, copper status indexes decreased only 2-fold as compared to control rats. In rats of both groups, silver entered the bloodstream and accumulated in the liver. Silver was incorporated into ceruloplasmin (Cp), but not SOD1. In the liver, a prolonged Ag-diet caused a decrease of the expression level of genes, associated with copper metabolism. Comparative spectrophotometric analysis of partially purified Cp fractions has shown that Cp from Ag-N6 rats was closer to holo-Cp by specific enzymatic activities and tertiary structure than Cp from Ag-A1 rats. However, Cp of Ag-N6 differs from control holo-Cp and Cp of Ag-A1 in its affinity to DEAE-Sepharose and in its binding properties to lectins. In the bloodstream of Ag-N6, two Cp forms are present as shown in pulse-experiments on rats with the liver isolated from circulation. One of the Cp isoforms is of hepatic origin, and the other is of extrahepatic origin; the latter is characterized by a faster rate of secretion than hepatic Cp. These data allowed us to suggest that the disturbance of holo-Cp formation in the liver was compensated by induction of extrahepatic Cp synthesis. The possible biological importance of these effects is discussed.

Occupational exposure to chromium, copper and arsenic during work with impregnated wood in joinery shops.

Science.gov (United States)

Nygren, O; Nilsson, C A; Lindahl, R

1992-10-01

CCA-impregnated timber contains copper, chromium and arsenic (CCA), and occupational exposure to wood dust as well as the CCA compounds may occur in work with such timber. Dust from commercially available impregnated wood has been found to contain hexavalent chromium, which is regarded as a carcinogen. Apart from determinations of the total amounts of the CCA compounds, specific determination of hexavalent chromium is therefore essential. Selective methods have been applied for control of the work environment in six joinery shops. The mean exposure to wood dust was found to be below 1 mg m-3. The mean airborne concentration of arsenic around various types of joinery machines was in the range from 0.54 to 3.1 micrograms m-3. No hexavalent chromium was detected in any samples and no increased concentrations of arsenic were found in urine from the workers. The presence of arsenic in the work-room air must be considered for appropriate assessment of the occupational environment in joinery shops.

Increased albumin excretion in industrial workers due to shift work rather than to prolonged exposure to low concentrations of chlorinated hydrocarbons.

OpenAIRE

Boogaard, P J; Caubo, M E

1994-01-01

OBJECTIVES--It has been reported that groups of workers in petrochemical industries who have been exposed to low concentrations of chemicals for prolonged periods have an increased urinary albumin excretion compared with unexposed controls. This increase, however, seemed to be unrelated to the extent, duration, and type of exposure. The aim of the present study was to investigate the suggestion that the small increase in albumin excretion might be due to differences in physical workload betwe...

Corrosion behavior of copper-base materials in a gamma-irradiated environment

International Nuclear Information System (INIS)

Yunker, W.H.

1990-09-01

Specimens of three copper-base materials were corrosion tested with gamma radiation exposure dose rates in the range of 1.9 x 10 3 R/h to 4.9 x 10 5 R/h. Materials used were pure copper, 7% aluminum bronze and 30% copper-nickel. Exposures were performed in moist air at 95 degree C and 150 degree C and liquid Well J-13 water at 95 degree C, for periods of up to 16 months. Specimens were monitored for uniform weight loss, stress-induced corrosion and crevice corrosion. Specimen surfaces were examined visually at 10X magnification as well as by Auger Electron Spectroscopy, x-ray diffraction and metallography. Corrosion was not severe in any of the cases. In general, the pure copper was corroded most uniformly while the copper-nickel was the least reproducibly corroded. 11 refs, 40 figs., 15 tabs

Copper substrate as a catalyst for the oxidation of chemical vapor deposition-grown graphene

International Nuclear Information System (INIS)

Li, Zhiting; Zhou, Feng; Parobek, David; Shenoy, Ganesh J.; Muldoon, Patrick; Liu, Haitao

2015-01-01

We report the catalytic effect of copper substrate on graphene–oxygen reaction at high temperature. Previous studies showed that graphene grown on copper are mostly defect-free with strong oxidation resistance. We found that a freshly prepared copper-supported graphene sample can be completely oxidized in trace amount of oxygen (<3 ppm) at 600 °C within 2 h. Both X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) suggest that upon ambient air exposure, oxygen molecules diffuse into the space between graphene and copper, resulting in the formation of copper oxide which acts as catalytic sites for the graphene-oxygen reaction. This result has important implications for the characterization, processing, and storage of copper-supported graphene samples. - Graphical abstract: The copper substrate enhances the thermel oxidation of single-layer graphene. - Highlights: • A copper-supported graphene can be oxidized in Ar (O 2 <3 ppm, 600 °C, 2 h). • O 2 intercalates between graphene and copper upon exposure to air. • The copper foil should not be considered as an inert substrate

Hepatocyte nuclear structure and subcellular distribution of copper in zebrafish Brachydanio rerio and roach Rutilus rutilus (Teleostei, Cyprinidae) exposed to copper sulphate

Energy Technology Data Exchange (ETDEWEB)

Paris-Palacios, Severine [Universite de Reims Champagne-Ardenne (URCA), UFR Sciences Exactes et Naturelles, Laboratoire d' Eco-Toxicologie, Institut International de Recherche sur les Ions Metalliques, B.P. 1039-51687 Reims cedex 2 (France)]. E-mail: severine.paris@univ-reims.fr; Biagianti-Risbourg, Sylvie [Universite de Reims Champagne-Ardenne (URCA), UFR Sciences Exactes et Naturelles, Laboratoire d' Eco-Toxicologie, Institut International de Recherche sur les Ions Metalliques, B.P. 1039-51687 Reims cedex 2 (France)]. E-mail: sylvie.biagianti@univ-reims.fr

2006-05-10

Copper is a trace element essential to life, but also a heavy metal with toxic effect clearly demonstrated. Cu induced perturbations in fish liver are well documented but the variability of the reported results is large. In this study two cyprinids, zebrafish and roach, were exposed to copper. Reported histocytological changes are either adaptative or degenerative depending on fish species, concentration of metal, and duration of exposure. Hepatic subcellular distribution of copper was determined by X-ray microanalysis in control and Cu-exposed roach and zebrafish. Sublethal copper sulphate contamination induced the development of a particular nucleolar alteration forming a network or honeycomb like structure in liver. This perturbation is observable in almost all the hepatocytes of zebrafish and roach exposed to copper for a minimum of 4 days of exposure. It seemed to concern more precisely the pars fibrosa. X-ray microanalysis showed that the appearance of network nucleolus was in relation to a Cu accumulation. Cu deposit was well located in the network as pars granulosa and nucloplasm showed very lower metal concentrations. The origin and consequence of network structure in nucleolus was discussed.

Hepatocyte nuclear structure and subcellular distribution of copper in zebrafish Brachydanio rerio and roach Rutilus rutilus (Teleostei, Cyprinidae) exposed to copper sulphate

International Nuclear Information System (INIS)

Paris-Palacios, Severine; Biagianti-Risbourg, Sylvie

2006-01-01

Copper is a trace element essential to life, but also a heavy metal with toxic effect clearly demonstrated. Cu induced perturbations in fish liver are well documented but the variability of the reported results is large. In this study two cyprinids, zebrafish and roach, were exposed to copper. Reported histocytological changes are either adaptative or degenerative depending on fish species, concentration of metal, and duration of exposure. Hepatic subcellular distribution of copper was determined by X-ray microanalysis in control and Cu-exposed roach and zebrafish. Sublethal copper sulphate contamination induced the development of a particular nucleolar alteration forming a network or honeycomb like structure in liver. This perturbation is observable in almost all the hepatocytes of zebrafish and roach exposed to copper for a minimum of 4 days of exposure. It seemed to concern more precisely the pars fibrosa. X-ray microanalysis showed that the appearance of network nucleolus was in relation to a Cu accumulation. Cu deposit was well located in the network as pars granulosa and nucloplasm showed very lower metal concentrations. The origin and consequence of network structure in nucleolus was discussed

The Role of Grain Size on Neutron Irradiation Response of Nanocrystalline Copper

Directory of Open Access Journals (Sweden)

Walid Mohamed

2016-03-01

Full Text Available The role of grain size on the developed microstructure and mechanical properties of neutron irradiated nanocrystalline copper was investigated by comparing the radiation response of material to the conventional micrograined counterpart. Nanocrystalline (nc and micrograined (MG copper samples were subjected to a range of neutron exposure levels from 0.0034 to 2 dpa. At all damage levels, the response of MG-copper was governed by radiation hardening manifested by an increase in strength with accompanying ductility loss. Conversely, the response of nc-copper to neutron irradiation exhibited a dependence on the damage level. At low damage levels, grain growth was the primary response, with radiation hardening and embrittlement becoming the dominant responses with increasing damage levels. Annealing experiments revealed that grain growth in nc-copper is composed of both thermally-activated and irradiation-induced components. Tensile tests revealed minimal change in the source hardening component of the yield stress in MG-copper, while the source hardening component was found to decrease with increasing radiation exposure in nc-copper.

Examining mechanism of toxicity of copper oxide nanoparticles to Saccharomyces cerevisiae and Caenorhabditis elegans

Science.gov (United States)

Mashock, Michael J.

Copper oxide nanoparticles (CuO NPs) are an up and coming technology increasingly being used in industrial and consumer applications and thus may pose risk to humans and the environment. In the present study, the toxic effects of CuO NPs were studied with two model organisms Saccharomyces cerevisiae and Caenorhabditis elegans. The role of released Cu ions during dissolution of CuO NPs in growth media were studied with freshly suspended, aged NPs, and the released Cu 2+ fraction. Exposures to the different Cu treatments showed significant inhibition of S. cerevisiae cellular metabolic activity. Inhibition from the NPs was inversely proportional to size and was not fully explained by the released Cu ions. S. cerevisiae cultures grown under respiring conditions demonstrated greater metabolic sensitivity when exposed to CuO NPs compared to cultures undergoing fermentation. The cellular response to both CuO NPs and released Cu ions on gene expression was analyzed via microarray analysis after an acute exposure. It was observed that both copper exposures resulted in an increase in carbohydrate storage, a decrease in protein production, protein misfolding, increased membrane permeability, and cell cycle arrest. Cells exposed to NPs up-regulated genes related to oxidative phosphorylation but also may be inducing cell cycle arrest by a different mechanism than that observed with released Cu ions. The effect of CuO NPs on C. elegans was examined by using several toxicological endpoints. The CuO NPs displayed a more inhibitory effect, compared to copper sulfate, on nematode reproduction, feeding, and development. We investigated the effects of copper oxide nanoparticles and copper sulfate on neuronal health, a known tissue vulnerable to heavy metal toxicity. In transgenic C. eleganswith neurons expressing a green fluorescent protein reporter, neuronal degeneration was observed in up to 10% of the population after copper oxide nanoparticle exposure. Additionally, nematode

Swelling of copper-aluminum and copper-nickel alloys in FFTF-MOTA at approximately 4500C

International Nuclear Information System (INIS)

Garner, F.A.; Brager, H.R.

1986-06-01

Pure copper appears to swell with an S-shaped behavior at 450 0 C, tending to saturate at higher fluence levels. The addition of solutes such as aluminum and nickel at 5 wt % leads to an extended transient regime and thereby a reduction in swelling at low to moderate fast neutron exposures. The addition of these elements also leads to an increase in the saturation level of swelling, however, resulting in an increase in swelling relative to that of pure copper at high fluence

Low water conductivity increases the effects of copper on the serum parameters in fish (Oreochromis niloticus).

Science.gov (United States)

Canli, Esin G; Canli, Mustafa

2015-03-01

The conductivity is largely determined by ion levels in water, predominant ion being Ca(2+) in the freshwaters. For this reason, the effects of copper were evaluated as a matter of conductivity of exposure media in the present study. Thus, freshwater fish Oreochromis niloticus were exposed to copper in differing conductivities (77, 163 and 330 μS/cm), using acute (0.3 μM, 3 d) and chronic (0.03 μM, 30 d) exposure protocols. Following the exposure serum parameters of fish were measured. Data showed that there was no significant alteration (P>0.05) in serum parameters of control fish. However, activities of ALP, ALT and AST decreased significantly at the lower conductivities in chronic copper exposure, but not in acute ones. Protein levels did not differ significantly in any of the exposure conditions. However, Cu exposure at the lowest conductivity sharply increased the levels of glucose in the acute exposure, while there was no significant difference in the chronic exposure. Cholesterol levels decreased only at the lower conductivities in chronic exposure, but increased in acute exposure. Similarly, triglyceride levels increased in acute exposures and decreased in chronic exposures at the lowest conductivity. There was no change in Na(+) levels, while there was an increase in K(+) levels and a decrease in Ca(2+) level at the lowest conductivity of acute exposures. However, Cl(-) levels generally decreased at the higher conductivities of chronic exposures. There was a strong negative relationship between significant altered serum parameters and water conductivity. In conclusion, this study showed that copper exposure of fish at lower conductivities caused more toxicities, indicating the protective effect of calcium ions against copper toxicity. Data suggest that conductivity of water may be used in the evaluation of metal data from different waters with different chemical characteristics. Copyright © 2015 Elsevier B.V. All rights reserved.

Is Exposure Necessary? A Randomized Clinical Trial of Interpersonal Psychotherapy for PTSD

Science.gov (United States)

Markowitz, John C.; Petkova, Eva; Neria, Yuval; Van Meter, Page E.; Zhao, Yihong; Hembree, Elizabeth; Lovell, Karina; Biyanova, Tatyana; Marshall, Randall D.

2015-01-01

Background Exposure to trauma reminders has been considered imperative in psychotherapy for posttraumatic stress disorder (PTSD). No treatment benefits all patients, however. We tested Interpersonal Psychotherapy, which has demonstrated antidepressant efficacy and showed promise in pilot PTSD research, as a non-exposure-based, non-cognitive behavioral PTSD treatment. Methods A randomized, fourteen-week trial compared Interpersonal Psychotherapy; Prolonged Exposure, an exposure-based exemplar; and Relaxation Therapy, an active control psychotherapy. Subjects were 110 unmedicated patients having DSM-IV chronic PTSD and Clinician-Administered PTSD Scale (CAPS) score >50. Randomization stratified for comorbid major depression. We hypothesized Interpersonal Psychotherapy would be no more than minimally inferior (CAPS difference 30% CAPS improvement) were: Interpersonal Psychotherapy 63%, Prolonged Exposure 47%, Relaxation Therapy 38% (n.s.). Interpersonal psychotherapy and Prolonged Exposure CAPS outcome differed by 5.5 points (n.s.); the null hypothesis of more than minimal Interpersonal Psychotherapy inferiority was rejected (p=0.035). Patients with comorbid major depression dropped out from Prolonged Exposure nine times more than non-depressed Prolonged Exposure patients. Interpersonal Psychotherapy and Prolonged Exposure improved quality of life and social functioning more than Relaxation Therapy. Conclusions This first controlled study of individual Interpersonal Psychotherapy for PTSD demonstrated non-inferiority to the “gold standard” PTSD treatment. Interpersonal Psychotherapy had (non-significantly) lower attrition and higher response rates than Prolonged Exposure. Contradicting a widespread clinical belief, PTSD treatment may not require cognitive behavioral exposure to trauma reminders. Moreover, as differential therapeutics, patients with comorbid major depression may fare better in Interpersonal Psychotherapy than Prolonged Exposure. PMID:25677355

Gold, nickel and copper mining and processing.

Science.gov (United States)

Lightfoot, Nancy E; Pacey, Michael A; Darling, Shelley

2010-01-01

Ore mining occurs in all Canadian provinces and territories except Prince Edward Island. Ores include bauxite, copper, gold, iron, lead and zinc. Workers in metal mining and processing are exposed, not only to the metal of interest, but also to various other substances prevalent in the industry, such as diesel emissions, oil mists, blasting agents, silica, radon, and arsenic. This chapter examines cancer risk related to the mining of gold, nickel and copper. The human carcinogenicity of nickel depends upon the species of nickel, its concentration and the route of exposure. Exposure to nickel or nickel compounds via routes other than inhalation has not been shown to increase cancer risk in humans. As such, cancer sites of concern include the lung, and the nasal sinus. Evidence comes from studies of nickel refinery and leaching, calcining, and sintering workers in the early half of the 20th century. There appears to be little or no detectable risk in most sectors of the nickel industry at current exposure levels. The general population risk from the extremely small concentrations detectable in ambient air are negligible. Nevertheless, animal carcinogenesis studies, studies of nickel carcinogenesis mechanisms, and epidemiological studies with quantitative exposure assessment of various nickel species would enhance our understanding of human health risks associated with nickel. Definitive conclusions linking cancer to exposures in gold and copper mining and processing are not possible at this time. The available results appear to demand additional study of a variety of potential occupational and non-occupational risk factors.

Identification of target organs of copper nanoparticles with ICP-MS technique

International Nuclear Information System (INIS)

Zhen Chen; Huan Meng; Yun Wang; Chengcheng Zhang; Yuliang Zhao

2007-01-01

Nanosized copper particles are widely used in fields of lubricants, polymers/plastic, metallic coating and ink. Recently, we found that copper particles in different sizes can lead to different toxicological effects. To clarify the target organs of copper particles of different sizes, the inductively coupled plasma mass spectroscopy (ICP-MS) was employed to evaluate the distribution of copper in different organs of mice after a single dose oral exposure. The results suggest that the main target organs for copper nanoparticles are kidney, liver and blood. Liver is the main damaged organ. (author)

Competing for Consciousness: Prolonged Mask Exposure Reduces Object Substitution Masking

Science.gov (United States)

Goodhew, Stephanie C.; Visser, Troy A. W.; Lipp, Ottmar V.; Dux, Paul E.

2011-01-01

In object substitution masking (OSM) a sparse, temporally trailing 4-dot mask impairs target identification, even though it has different contours from, and does not spatially overlap with the target. Here, we demonstrate a previously unknown characteristic of OSM: Observers show reduced masking at prolonged (e.g., 640 ms) relative to intermediate…

Cytogenetical and ultrastructural effects of copper on root meristem cells of Allium sativum L.

Science.gov (United States)

Liu, Donghua; Jiang, Wusheng; Meng, Qingmin; Zou, Jin; Gu, Jiegang; Zeng, Muai

2009-04-01

Different copper concentrations, as well as different exposure times, were applied to investigate both cytogenetical and ultrastructural alterations in garlic (Allium sativum L.) meristem cells. Results showed that the mitotic index decreased progressively when either copper concentration or exposure time increased. C-mitosis, anaphase bridges, chromosome stickiness and broken nuclei were observed in the copper treated root tip cells. Some particulates containing the argyrophilic NOR-associated proteins were distributed in the nucleus of the root-tip cells and the amount of this particulate material progressively increased with increasing exposure time. Finally, the nucleolar material was extruded from the nucleus into the cytoplasm. Also, increased dictyosome vesicles in number, formation of cytoplasmic vesicles containing electron dense granules, altered mitochondrial shape, disruption of nuclear membranes, condensation of chromatin material, disintegration of organelles were observed. The mechanisms of detoxification and tolerance of copper are briefly discussed.

Copper-induced immunotoxicity involves cell cycle arrest and cell death in the spleen and thymus

International Nuclear Information System (INIS)

Mitra, Soham; Keswani, Tarun; Dey, Manali; Bhattacharya, Shaswati; Sarkar, Samrat; Goswami, Suranjana; Ghosh, Nabanita; Dutta, Anuradha; Bhattacharyya, Arindam

2012-01-01

Copper is an essential trace element for human physiological processes. To evaluate the potential adverse health impact/immunotoxicological effects of this metal in situ due to over exposure, Swiss albino mice were treated (via intraperitoneal injections) with copper (II) chloride (copper chloride) at doses of 0, 5, or 7.5 mg copper chloride/kg body weight (b.w.) twice a week for 4 wk; these values were derived from LD 50 studies using copper chloride doses that ranged from 0 to 40 mg/kg BW (2×/wk, for 4 wk). Copper treated mice evidenced immunotoxicity as indicated by dose-related decreases and increases, respectively, in thymic and splenic weights. Histomorphological changes evidenced in these organs were thymic atrophy, white pulp shrinkage in the spleen, and apoptosis of splenocytes and thymocytes; these observations were confirmed by microscopic analyses. Cell count analyses indicated that the proliferative functions of the splenocytes and thymocytes were also altered because of the copper exposures. Among both cell types from the copper treated hosts, flow cytometric analyses revealed a dose related increase in the percentages of cells in the Sub-G 0 /G 1 state, indicative of apoptosis which was further confirmed by Annexin V binding assay. In addition, the copper treatments altered the expression of selected cell death related genes such as EndoG and Bax in a dose related manner. Immunohistochemical analyses revealed that there was also increased ubiquitin expression in both the cell types. In conclusion, these studies show that sublethal exposure to copper (as copper chloride) induces toxicity in the thymus and spleen, and increased Sub G 0 /G 1 population among splenocytes and thymocytes that is mediated, in part, by the EndoG–Bax–ubiquitin pathway. This latter damage to these cells that reside in critical immune system organs are likely to be important contributing factors underlying the immunosuppression that has been documented by other

Betacyanin accumulation and guaiacol peroxidase activity in Beta vulgaris L. leaves following copper stress

Directory of Open Access Journals (Sweden)

Janet M. León Morales

2012-07-01

Full Text Available The effect of copper stress on betacyanin accumulation and guaiacol peroxidase (GPOD activity in leaves of different age was evaluated in red beet (Beta vulgaris L. var. Crosby Egyptian plants. In hydroponic culture, plants were treated with 0.3 μM (control, 50 μM, 100 μM, and 250 μM of CuSO4 for 6 days. Copper was taken up and accumulated in old roots but was not translocated to leaves. However in young leaves, the increase of lipid peroxidation and reduction of growth were evident from day 3 of copper exposure; whereas in old leaves, the lipid peroxidation and growth were the same from either copper-treated or control plants. In response to copper exposure, the betacyanin accumulation was evident in young leaves by day 3, and continued to increase until day 6. Betacyanin only were accumulated in old leaves until day 6, but the contents were from 4 to 5 times lower than those observed in young leaves at the same copper concentrations. GPOD activity increased 3.3- and 1.4-fold in young and old leaves from day 3 of copper treatment respectively, but only in the young leaves was sustained at the same level until day 6. Old roots shown betacyanin in the control plants, but the betacyanin level and growth were reduced with the copper exposure. In contrast, young roots emerged by copper effect also accumulated copper and showed the highest betacyanin content of all plant parts assayed. These results indicate that betacyanin accumulation and GPOD activity are defense responses to copper stress in actively growing organs.

Chronic sensitivity of white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) to cadmium, copper, lead, or zinc in laboratory water-only exposures

Science.gov (United States)

Wang, Ning; Ingersoll, Christopher G.; Dorman, Rebecca A.; Brumbaugh, William G.; Mebane, Christopher A.; Kunz, James L.; Hardesty, Douglas K.

2014-01-01

Chronic toxicity of cadmium, copper, lead, or zinc to white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) was evaluated in water-only exposures started with newly hatched larvae or approximately 1-mo-old juveniles. The 20% effect concentration (EC20) for cadmium from the sturgeon tests was higher than the EC20 from the trout tests, whereas the EC20 for copper, lead, or zinc for the sturgeon were lower than those EC20s for the trout. When the EC20s from the present study were included in compiled toxicity databases for all freshwater species, species mean chronic value for white sturgeon was in a relatively low percentile of the species sensitivity distribution for copper (9th percentile) and in the middle percentile for cadmium (55th percentile), zinc (40th percentile), or lead (50th percentile). However, the species mean chronic value for rainbow trout was in a high percentile for copper, lead, and zinc (∼68th–82nd percentile), but in a low percentile for cadmium (23rd percentile). The trout EC20s for each of the 4 metals and the sturgeon EC20s for cadmium or lead were above US Environmental Protection Agency chronic ambient water quality criteria (AWQC) or Washington State chronic water quality standards (WQS), whereas the sturgeon EC20s for copper or zinc were approximately equal to or below the chronic AWQC and WQS. In addition, acute 50% effect concentrations (EC50s) for copper obtained in the first 4 d of the chronic sturgeon test were below the final acute value used to derive acute AWQC and below acute WQS for copper.

Sub-cellular damage by copper in the cnidarian Zoanthus robustus.

Science.gov (United States)

Grant, A; Trompf, K; Seung, D; Nivison-Smith, L; Bowcock, H; Kresse, H; Holmes, S; Radford, J; Morrow, P

2010-09-01

Sessile organisms may experience chronic exposure to copper that is released into the marine environment from antifoulants and stormwater runoff. We have identified the site of damage caused by copper to the symbiotic cnidarian, Zoanthus robustus (Anthozoa, Hexacorallia). External changes to the zoanthids were apparent when compared with controls. The normally flexible bodies contracted and became rigid. Histological examination of the zoanthid tissue revealed that copper had caused sub-cellular changes to proteins within the extracellular matrix (ECM) of the tubular body. Collagen in the ECM and the internal septa increased in thickness to five and seven times that of controls respectively. The epithelium, which stained for elastin, was also twice as thick and tough to cut, but exposure to copper did not change the total amount of desmosine which is found only in elastin. We conclude that copper stimulated collagen synthesis in the ECM and also caused cross-linking of existing proteins. However, there was no expulsion of the symbiotic algae (Symbiodinium sp.) and no effect on algal pigments or respiration (44, 66 and 110 microg Cu L(-1)). A decrease in net photosynthesis was observed only at the highest copper concentration (156 microg Cu L(-1)). These results show that cnidarians may be more susceptible to damage by copper than their symbiotic algae. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Prolonged Pulmonary Exposure to Diesel Exhaust Particles Exacerbates Renal Oxidative Stress, Inflammation and DNA Damage in Mice with Adenine-Induced Chronic Renal Failure

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Abderrahim Nemmar

2016-05-01

Full Text Available Background/Aims: Epidemiological evidence indicates that patients with chronic kidney diseases have increased susceptibility to adverse outcomes related to long-term exposure to particulate air pollution. However, mechanisms underlying these effects are not fully understood. Methods: Presently, we assessed the effect of prolonged exposure to diesel exhaust particles (DEP on chronic renal failure induced by adenine (0.25% w/w in feed for 4 weeks, which is known to involve inflammation and oxidative stress. DEP (0.5m/kg was intratracheally (i.t. instilled every 4th day for 4 weeks (7 i.t. instillation. Four days following the last exposure to either DEP or saline (control, various renal endpoints were measured. Results: While body weight was decreased, kidney weight increased in DEP+adenine versus saline+adenine or DEP. Water intake, urine volume, relative kidney weight were significantly increased in adenine+DEP versus DEP and adenine+saline versus saline. Plasma creatinine and urea increased and creatinine clearance decreased in adenine+DEP versus DEP and adenine+saline versus saline. Tumor necrosis factor α, lipid peroxidation and reactive oxygen species were significantly increased in adenine+DEP compared with either DEP or adenine+saline. The antioxidant calase was significantly decreased in adenine+DEP compared with either adenine+saline or DEP. Notably, renal DNA damage was significantly potentiated in adenine+DEP compared with either adenine+saline or DEP. Similarly, systolic blood pressure was increased in adenine+DEP versus adenine+saline or DEP, and in DEP versus saline. Histological evaluation revealed more collagen deposition, higher number of necrotic cell counts and dilated tubules, cast formation and collapsing glomeruli in adenine+DEP versus adenine+saline or DEP. Conclusion: Prolonged pulmonary exposure to diesel exhaust particles worsen renal oxidative stress, inflammation and DNA damage in mice with adenine-induced chronic

The effects of low-level ionizing radiation and copper exposure on the incidence of antibiotic resistance in lentic biofilm bacteria.

Science.gov (United States)

McArthur, J Vaun; Dicks, Christian A; Bryan, A Lawrence; Tuckfield, R Cary

2017-09-01

Environmental reservoirs of antibiotic resistant bacteria are poorly understood. Understanding how the environment selects for resistance traits in the absence of antibiotics is critical in developing strategies to mitigate this growing menace. Indirect or co-selection of resistance by environmental pollution has been shown to increase antibiotic resistance. However no attention has been given to the effects of low-level ionizing radiation or the interactions between radiation and heavy metals on the maintenance or selection for antibiotic resistance (AR) traits. Here we explore the effect of radiation and copper on antibiotic resistance. Bacteria were collected from biofilms in two ponds - one impacted by low-level radiocesium and the other an abandoned farm pond. Through laboratory controlled experiments we examined the effects of increasing concentrations of copper on the incidence of antibiotic resistance. Differences were detected in the resistance profiles of the controls from each pond. Low levels (0.01 mM) of copper sulfate increased resistance but 0.5 mM concentrations of copper sulfate depressed the AR response in both ponds. A similar pattern was observed for levels of multiple antibiotic resistance per isolate. The first principal component response of isolate exposure to multiple antibiotics showed significant differences among the six isolate treatment combinations. These differences were clearly visualized through a discriminant function analysis, which showed distinct antibiotic resistance response patterns based on the six treatment groups. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microwave enhanced recovery of nickel-copper ore: communition and floatability aspects.

Science.gov (United States)

Henda, R; Hermas, A; Gedye, R; Islam, M R

2005-01-01

A study describing the effect of microwave radiation, at a frequency of 2450 MHz, on the processes of communication and flotation of a complex sulphide nickel-copper ore is presented. Ore communication has been investigated under standard radiation-free conditions and after ore treatment in a radiated environment as a function of ore size, exposure time to radiation, and microwave power. The findings show that communication is tremendously improved by microwave radiation with values of the relative work index as low as 23% at a microwave power of 1.406 kW and after 10 s of exposure time. Communication is affected by exposure time and microwave power in a nontrivial manner. In terms of ore floatability, the experimental tests have been carried out on a sample of 75 microm in size under different exposure times. The results show that both ore concentrate recoveries and grades of nickel and copper are significantly enhanced after microwave treatment of the ore with relative increases in recovered concentrate, grade of nickel, and grade of copper of 26 wt%, 15 wt%, and 27%, respectively, at a microwave power of 1330 kW and after 30 s of exposure time.

Corrosion mechanism of copper in palm biodiesel

International Nuclear Information System (INIS)

Fazal, M.A.; Haseeb, A.S.M.A.; Masjuki, H.H.

2013-01-01

Highlights: ► Corrosion of copper in biodiesel increases with the increase of immersion time. ► The corrosion patina is found to be composed of CuO, Cu 2 O, CuCO 3 and Cu(OH) 2 . ► Green CuCO 3 was found as the major corrosion product. ► The mechanisms governing corrosion of copper in palm biodiesel are discussed. - Abstract: Biodiesel is a promising alternative fuel. However, it causes enhanced corrosion of automotive materials, especially of copper based components. In the present study, corrosion mechanism of copper was investigated by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Compositional change of biodiesel due to the exposure of copper was also investigated. Corrosion patina on copper is found to be composed of Cu 2 O, CuO, Cu(OH) 2 and CuCO 3. Dissolved O 2 , H 2 O, CO 2 and RCOO − radical in biodiesel seem to be the leading factors in enhancing the corrosiveness of biodiesel.

Prolonged Corrosion Stability of a Microchip Sensor Implant during In Vivo Exposure

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Paul Glogener

2018-02-01

Full Text Available A microelectronic biosensor was subjected to in vivo exposure by implanting it in the vicinity of m. trapezii (Trapezius muscle from cattle. The implant is intended for the continuous monitoring of glucose levels, and the study aimed at evaluating the biostability of exposed semiconductor surfaces. The sensor chip was a microelectromechanical system (MEMS prepared using 0.25 µm complementary metal–oxide–semiconductor CMOS/BiCMOS technology. Sensing is based on the principle of affinity viscometry with a sensoric assay, which is separated by a semipermeable membrane from the tissue. Outer dimensions of the otherwise hermetically sealed biosensor system were 39 × 49 × 16 mm. The test system was implanted into cattle in a subcutaneous position without running it. After 17 months, the device was explanted and analyzed by comparing it with unexposed chips and systems. Investigations focused on the MEMS chip using SEM, TEM, and elemental analysis by EDX mapping. The sensor chip turned out to be uncorroded and no diminishing of the topmost passivation layer could be determined, which contrasts remarkably with previous results on CMOS biosensors. The negligible corrosive attack is understood to be a side effect of the semipermeable membrane separating the assay from the tissue. It is concluded that the separation has enabled a prolonged biostability of the chip, which will be of relevance for biosensor implants in general.

How do anthropogenic contaminants (ACs) affect behaviour? Multi-level analysis of the effects of copper on boldness in hermit crabs.

Science.gov (United States)

White, Stephen J; Briffa, Mark

2017-02-01

Natural animal populations are increasingly exposed to human impacts on the environment, which could have consequences for their behaviour. Among these impacts is exposure to anthropogenic contaminants. Any environmental variable that influences internal state could impact behaviour across a number of levels: at the sample mean, at the level of among-individual differences in behaviour ('animal personality') and at the level of within-individual variation in behaviour (intra-individual variation, 'IIV'). Here we examined the effect of exposure to seawater-borne copper on the startle response behaviour of European hermit crabs, Pagurus bernhardus across these levels. Copper exposure rapidly led to longer startle responses on average, but did not lead to any change in repeatability indicating that individual differences were present and equally consistent in the presence and absence of copper. There was no strong evidence that copper exposure led to changes in IIV. Our data show that exposure to copper for 1 week produces sample mean level changes in the behaviour of hermit crabs. However, there is no evidence that this exposure led to changes in repeatability through feedback loops.

Music exposure induced prolongation of cardiac allograft survival and generated regulatory CD4⁺ cells in mice.

Science.gov (United States)

Uchiyama, M; Jin, X; Zhang, Q; Amano, A; Watanabe, T; Niimi, M

2012-05-01

In clinical practice, music has been used to decrease stress, heart rate, and blood pressure and to provide a distraction from disease symptoms. We investigated sound effects on alloimmune responses in murine heart transplantation. Naïve and eardrum-ruptured CBA/N (CBA, H2(K)) underwent transplantation of a C57BL/6 (B6, H2(b)) heart and were exposed to 1 of 3 types of music-opera (La Traviata), classical (Mozart), and New Age (Enya)-or 1 of 6 different single sound frequencies for 7 days. An adoptive transfer study was performed to determine whether regulatory cells were generated in allograft recipients. Cell-proliferation, cytokine, and flow cytometry assessments were also performed. CBA recipients of a B6 graft exposed to opera and classical music had significantly prolonged allograft survival (median survival times [MSTs], 26.5 and 20 days, respectively), whereas those exposed to 6 single sound frequencies and New Age did not (MSTs, 7, 8, 9, 8, 8, 8, and 11 days, respectively). Untreated and eardrum-ruptured CBA rejected B6 grafts acutely (MSTs, 7 and 8.5 days, respectively). Adoptive transfer of whole splenocytes, CD4(+) cells, and CD4(+)CD25(+) cells from opera-exposed primary recipients resulted in significantly prolonged allograft survival in naive secondary recipients (MSTs, 36, 68, and >50 days, respectively). Cell-proliferation, interleukin (IL)-2 and interferon-γ were suppressed in opera-exposed mice, whereas IL-4 and IL-10 from opera-exposed recipients were up-regulated. Flow cytometry studies showed an increased CD4(+)CD25(+)Foxp3(+) cell population in splenocytes from opera-exposed mice. In conclusion, exposure to some types of music may induce prolonged survival of fully allogeneic cardiac allografts and generate CD4(+)CD25(+)Foxp3(+) regulatory cells. Copyright © 2012 Elsevier Inc. All rights reserved.

Corrosion behavior of copper-base materials in a gamma-irradiated environment; Final report

Energy Technology Data Exchange (ETDEWEB)

Yunker, W.H.

1990-09-01

Specimens of three copper-base materials were corrosion tested with gamma radiation exposure dose rates in the range of 1.9 {times} 10{sup 3} R/h to 4.9 {times} 10{sup 5} R/h. Materials used were pure copper, 7% aluminum bronze and 30% copper-nickel. Exposures were performed in moist air at 95{degree}C and 150{degree}C and liquid Well J-13 water at 95{degree}C, for periods of up to 16 months. Specimens were monitored for uniform weight loss, stress-induced corrosion and crevice corrosion. Specimen surfaces were examined visually at 10X magnification as well as by Auger Electron Spectroscopy, x-ray diffraction and metallography. Corrosion was not severe in any of the cases. In general, the pure copper was corroded most uniformly while the copper-nickel was the least reproducibly corroded. 11 refs, 40 figs., 15 tabs.

Adsorption of 2-mercaptobenzothiazole on copper surface from phosphate solutions

International Nuclear Information System (INIS)

Kazansky, L.P.; Selyaninov, I.A.; Kuznetsov, Yu.I.

2012-01-01

Analysis of the electrochemical and XPS results has shown that adsorption of 2-mercaptobenzothiazole (MBT) on copper electrodes in neutral phosphate solutions proceeds through the formation of the chemical bonds by copper (I) cations with exo-sulfur and nitrogen atoms. A protection layer formed of Cu(I)MBT complex prevents precipitation of copper (II) phosphate on a copper surface. The thickness of the surface film consisting of a complex [Cu(I)MBT] n (having probably polymeric nature), where MBT acts as at least three-dentate ligand, increases depending on the exposure time, reaching 8-9 nm after immersing for 12 h in test solution. Even in a case of the preliminary formation of copper (II) phosphate on the copper electrode at the anodic potential addition of small amounts of MBT results in complete removal of copper (II) phosphate from the surface.

Within- and among-population level differences in response to chronic copper exposure in southern toads, Anaxyrus terrestris.

Science.gov (United States)

Lance, Stacey L; Flynn, R Wesley; Erickson, Matthew R; Scott, David E

2013-06-01

Environmental contaminants are implicated in the global decline of amphibian populations. Copper (Cu) is a widespread contaminant that can be toxic at concentrations just above the normal physiological range. In the present study we examined the effects of chronic Cu aqueous exposure on embryos and larvae of southern toads, Anaxyrus (Bufo) terrestris. Measurable levels of Cu were found in larvae, with tissue concentrations up to 27.5 μg Cu/g dry mass. Aqueous concentrations of Cu as low as 10 μg/L significantly reduced survival to the free-swimming stage and no larvae reached metamorphosis at concentrations above 15 μg/L. Clutches from populations with prior Cu exposure had the lowest survivorship. Among several populations there was significant variation in survivorship at different levels of Cu. More data are needed to understand the underlying causes of within- and among-population resilience to anthropogenic stressors. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of short- and long-term exposures to copper on lethal and reproductive endpoints of the harpacticoid copepod Tigriopus fulvus.

Science.gov (United States)

Biandolino, Francesca; Parlapiano, Isabella; Faraponova, Olga; Prato, Ermelinda

2018-01-01

The long-term exposure provides a realistic measurement of the effects of toxicants on aquatic organisms. The harpacticoid copepod Tigriopus fulvus has a wide geographical distribution and is considered as an ideal model organism for ecotoxicological studies for its good sensitivity to different toxicants. In this study, acute, sub-chronic and chronic toxicity tests based on lethal and reproductive responses of Tigriopus fulvus to copper were performed. The number of moults during larval development was chosen as an endpoint for sub-chronic test. Sex ratio, inhibitory effect on larval development, hatching time, fecundity, brood number, nauplii/brood, total newborn production, etc, were calculated in the chronic test (28d). Lethal effect of copper to nauplii showed the LC50-48h of 310 ± 72µgCu/L (mean ± sd). It was observed a significant inhibition of larval development at sublethal copper concentrations, after 4 and 7 d. After 4d, the EC50 value obtained for the endpoint in "moult naupliar reduction" was of 55.8 ± 2.5µgCu/L (mean ± sd). The EC50 for the inhibition of naupliar development into copepodite stage, was of 21.7 ± 4.4µgCu/L (mean ± sd), after 7 days. Among the different traits tested, copper did not affect sex ratio and growth, while fecundity and total nauplii production were the most sensitive endpoints. The reproductive endpoints offer the advantage of being detectable at very low pollutant concentrations. Copyright © 2017 Elsevier Inc. All rights reserved.

Corrosion of pure OFHC-copper in simulated repository conditions

International Nuclear Information System (INIS)

Aaltonen, P.

1990-04-01

The research program 'Corrosion of pure OFHC-copper in simulated repository conditions' was planned to provide an experimental evaluation with respect to the theoretical calculations and forecasts made for the corrosion behaviour of pure copper in bentonite groundwater environments at temperatures between 20-80 deg C. The aim of this study in the first place is to evaluate the effects of groundwater composition, bentonite and temperature on the equilibrium and possible corrosion reactions between pure copper and the simulated repository environment. The progress report includes the results obtained after 36 months exposure time

Prolonged inorganic arsenite exposure suppresses insulin-stimulated AKT S473 phosphorylation and glucose uptake in 3T3-L1 adipocytes: involvement of the adaptive antioxidant response.

Science.gov (United States)

Xue, Peng; Hou, Yongyong; Zhang, Qiang; Woods, Courtney G; Yarborough, Kathy; Liu, Huiyu; Sun, Guifan; Andersen, Melvin E; Pi, Jingbo

2011-04-08

There is growing evidence that chronic exposure of humans to inorganic arsenic, a potent environmental oxidative stressor, is associated with the incidence of type 2 diabetes (T2D). One critical feature of T2D is insulin resistance in peripheral tissues, especially in mature adipocytes, the hallmark of which is decreased insulin-stimulated glucose uptake (ISGU). Despite the deleterious effects of reactive oxygen species (ROS), they have been recognized as a second messenger serving an intracellular signaling role for insulin action. Nuclear factor erythroid 2-related factor 2 (NRF2) is a central transcription factor regulating cellular adaptive response to oxidative stress. This study proposes that in response to arsenic exposure, the NRF2-mediated adaptive induction of endogenous antioxidant enzymes blunts insulin-stimulated ROS signaling and thus impairs ISGU. Exposure of differentiated 3T3-L1 cells to low-level (up to 2 μM) inorganic arsenite (iAs³(+)) led to decreased ISGU in a dose- and time-dependent manner. Concomitant to the impairment of ISGU, iAs³(+) exposure significantly attenuated insulin-stimulated intracellular ROS accumulation and AKT S473 phosphorylation, which could be attributed to the activation of NRF2 and induction of a battery of endogenous antioxidant enzymes. In addition, prolonged iAs³(+) exposure of 3T3-L1 adipocytes resulted in significant induction of inflammatory response genes and decreased expression of adipogenic genes and glucose transporter type 4 (GLUT4), suggesting chronic inflammation and reduction in GLUT4 expression may also be involved in arsenic-induced insulin resistance in adipocytes. Taken together our studies suggest that prolonged low-level iAs³(+) exposure activates the cellular adaptive oxidative stress response, which impairs insulin-stimulated ROS signaling that is involved in ISGU, and thus causes insulin resistance in adipocytes. Copyright © 2011 Elsevier Inc. All rights reserved.

Cultural Adaptations of Prolonged Exposure Therapy for Treatment and Prevention of Posttraumatic Stress Disorder in African Americans

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Monnica T. Williams

2014-05-01

Full Text Available Posttraumatic stress disorder (PTSD is a highly disabling disorder, afflicting African Americans at disproportionately higher rates than the general population. When receiving treatment, African Americans may feel differently towards a European American clinician due to cultural mistrust. Furthermore, racism and discrimination experienced before or during the traumatic event may compound posttrauma reactions, impacting the severity of symptoms. Failure to adapt treatment approaches to encompass cultural differences and racism-related traumas may decrease treatment success for African American clients. Cognitive behavioral treatment approaches are highly effective, and Prolonged Exposure (PE in particular has the most empirical support for the treatment of PTSD. This article discusses culturally-informed adaptations of PE that incorporates race-related trauma themes specific to the Black experience. These include adding more sessions at the front end to better establish rapport, asking directly about race-related themes during the assessment process, and deliberately bringing to the forefront race-related experiences and discrimination during treatment when indicated. Guidelines for assessment and the development of appropriate exposures are provided. Case examples are presented demonstrating adaptation of PE for a survivor of race-related trauma and for a woman who developed internalized racism following a sexual assault. Both individuals experienced improvement in their posttrauma reactions using culturally-informed adaptations to PE.

Neonatal survival after prolonged preterm premature rupture of membranes before 24 weeks of gestation.

Science.gov (United States)

Brumbaugh, Jane E; Colaizy, Tarah T; Nuangchamnong, Nina; O'Brien, Emily A; Fleener, Diedre K; Rijhsinghani, Asha; Klein, Jonathan M

2014-11-01

To evaluate neonatal survival after prolonged preterm premature rupture of membranes (PROM) in the era of antenatal corticosteroids, surfactant, and inhaled nitric oxide. A single-center retrospective cohort study of neonates born from 2002-2011 after prolonged (1 week or more) preterm (less than 24 weeks of gestation) rupture of membranes was performed. The primary outcome was survival to discharge. Neonates whose membranes ruptured less than 24 hours before delivery (n=116) were matched (2:1) on gestational age at birth, sex, and antenatal corticosteroid exposure with neonates whose membranes ruptured 1 week or more before delivery (n=58). Analysis used conditional logistic regression for categorical data and Wilcoxon signed rank test for continuous data. The prolonged preterm PROM exposed and unexposed cohorts had survival rates of 90% and 95%, respectively, although underpowered to assess the statistical significance (P=.313). Exposed neonates were more likely have pulmonary hypoplasia (26/58 exposed, 1/114 unexposed, Prupture (20.4 weeks exposed, 22.3 weeks unexposed, P=.189), length of rupture (3.7 weeks exposed, 6.4 weeks unexposed, P=.717), and lowest maximal vertical pocket before 24 weeks of gestation (0 cm exposed, 1.4 cm unexposed, P=.114) did not discriminate between survivors and nonsurvivors after exposure to prolonged preterm PROM. With antenatal steroid exposure and aggressive pulmonary management, survival to discharge after prolonged preterm PROM was 90%. Pulmonary morbidities were common. Of note, the data were limited to women who remained pregnant 1 week or longer after rupture of membranes.

The sublethal effects of copper and lead on the haematology and ...

African Journals Online (AJOL)

Toxicity bioassays were conducted on groovy mullet, Liza dumerili, using copper and lead, in order to assess how these metals affected their blood haematology and acid-base balance. Short-term (96 hours) exposure to lead caused significantly more haematological response [PCO2] than copper, when compared to the ...

XPS response in the corrosion products analysis for copper exposed at clean air environment

International Nuclear Information System (INIS)

Mariaca, L.; Morcillo, M.; Feliu Jr, S.; Gonzalez, J.A.

1998-01-01

In this work is presented the obtained response for superficial analysis technique by X-ray photoelectron spectroscopy (XPS or ESCA), to determine the corrosion products formed during the copper exposure at environment without pollutants (clean air) at 50, 70 and 90 % of relative humidity at 35 Centigrade. One of the copper corrosion products most knew is Cu 2 O. This oxide is formed instantly to be exposed the copper at air. However in function of the exposure time and the relative humidity at it is exposed, the Cu 2 O oxide is transformed at Cu O and Cu(OH) 2 (Author)

Laser sintering of copper nanoparticles

International Nuclear Information System (INIS)

Zenou, Michael; Saar, Amir; Ermak, Oleg; Kotler, Zvi

2014-01-01

Copper nanoparticle (NP) inks serve as an attractive potential replacement to silver NP inks in functional printing applications. However their tendency to rapidly oxidize has so far limited their wider use. In this work we have studied the conditions for laser sintering of Cu-NP inks in ambient conditions while avoiding oxidation. We have determined the regime for stable, low-resistivity copper (< ×3 bulk resistivity value) generation in terms of laser irradiance and exposure duration and have indicated the limits on fast processing. The role of pre-drying conditions on sintering outcome has also been studied. A method, based on spectral reflectivity measurements, was used for non-contact monitoring of the sintering process evolution. It also indicates preferred spectral regions for sintering. Finally, we illustrated how selective laser sintering can generate high-quality, fine line (<5 µm wide) and dense copper circuits. (paper)

Differential sexual survival of Drosophila melanogaster on copper sulfate.

Science.gov (United States)

Balinski, Michael A; Woodruff, Ronny C

2017-04-01

Based on studies of the influence of X-chromosomes on the viability of Drosophila melanogaster exposed to cadmium, and on the role of X-linked genes on copper homeostasis, we examined the effect of copper sulfate (CuSO 4 ) on offspring viability using three independent, inbred D. melanogaster crosses (ensuring identical autosomes for males and females within each cross). Each cross was performed with attached X-chromosome females and males with a single X-chromosome. As female D. melanogaster have less metallothionein RNA expression than males, we predicted fewer female offspring than male offspring in crosses exposed to CuSO 4 , even though females have two copies of X-chromosome genes, possibly resulting in overdominant heterozygosity. In two of three crosses, CuSO 4 caused significantly higher numbers of male offspring compared to female offspring. We hypothesized that these gender-based viability differences to copper exposure are caused by X-chromosome ploidy and X-linked genetic variation affecting metallothionein expression. Observed differential offspring viability responses among crosses to copper exposure also showed that different genetic backgrounds (autosomal and/or X-chromosome) can result in significant differences in heavy metal and metallothionein regulation. These results suggest that the effect of copper on offspring viability depends on both genetic background and gender, as both factors can affect the regulation of metallothionein proteins as well as homeostasis of biologically necessary heavy metals.

Baking effect on initial pumping characteristics of oxygen free copper duct

International Nuclear Information System (INIS)

Nagai, Yasuchika; Yamamoto, Yoshiki; Saito, Yoshio; Matsuda, Namio.

1994-01-01

Recently, attention has been paid to the application of oxygen-free copper to the field of vacuum vessels, such as the beam duct material for the B Factory. The initial exhaust characteristics of oxygen-free copper vessels were compared before and after the baking, and the change of the surface condition was examined. The material used for this experiment was the oxygen-free copper, to which vacuum degassing treatment was applied. The vacuum vessels of this oxygen-free copper and SUS316L stainless steel were made. The turbo-molecular pump of 400 liter/min and the scroll pump of 270 liter/min were used, and pressure measurement and the analysis of the components in remaining gas were carried out. The procedure of the experiment is explained. The exhaust curves for the oxygen-free copper and stainless steel vacuum vessels are shown. The time required for reaching 1x10 -6 Pa was about 1/2 after the exposure to nitrogen as compared with after the exposure to air, thus the kinds of gas exerted large influence to the exhaust characteristics. The difference before and after baking arose in most cases. (K.I.)

Baking effect on initial pumping characteristics of oxygen free copper duct

Energy Technology Data Exchange (ETDEWEB)

Nagai, Yasuchika; Yamamoto, Yoshiki [Hitachi Cable, Ltd., Tsuchiura, Ibaraki (Japan). System' s Material Lab.; Saito, Yoshio; Matsuda, Namio

1994-03-01

Recently, attention has been paid to the application of oxygen-free copper to the field of vacuum vessels, such as the beam duct material for the B Factory. The initial exhaust characteristics of oxygen-free copper vessels were compared before and after the baking, and the change of the surface condition was examined. The material used for this experiment was the oxygen-free copper, to which vacuum degassing treatment was applied. The vacuum vessels of this oxygen-free copper and SUS316L stainless steel were made. The turbo-molecular pump of 400 liter/min and the scroll pump of 270 liter/min were used, and pressure measurement and the analysis of the components in remaining gas were carried out. The procedure of the experiment is explained. The exhaust curves for the oxygen-free copper and stainless steel vacuum vessels are shown. The time required for reaching 1x10[sup -6] Pa was about 1/2 after the exposure to nitrogen as compared with after the exposure to air, thus the kinds of gas exerted large influence to the exhaust characteristics. The difference before and after baking arose in most cases. (K.I.).

Microstructural characterization of copper corrosion in aqueous and soil environments

International Nuclear Information System (INIS)

Srivastava, A.; Balasubramaniam, R.

2005-01-01

Scanning electron microscopy has been used to investigate the surface films on pure copper after exposure to different aqueous and soil environments, containing chloride, sulfide and ammonium salts. The morphology of the films formed on copper surface in aqueous and soil environments was different for the same amount of pollutants. The surface films formed in soil environments were not homogenous in contrast to the films formed in aqueous environments. The damaging effect of chloride ions and the benign role of sulfide ions were revealed in both the environments. Local compositional analysis confirmed that the surface films formed on copper consisted predominantly of copper and oxygen

Utilization of Copper Alloys for Marine Applications

Science.gov (United States)

Drach, Andrew

Utilization of copper alloy components in systems deployed in marine environment presents potential improvements by reducing maintenance costs, prolonging service life, and increasing reliability. However, integration of these materials faces technological challenges, which are discussed and addressed in this work, including characterization of material performance in seawater environment, hydrodynamics of copper alloy components, and design procedures for systems with copper alloys. To characterize the hydrodynamic behavior of copper alloy nets, mesh geometry of the major types of copper nets currently used in the marine aquaculture are analyzed and formulae for the solidity and strand length are proposed. Experimental studies of drag forces on copper alloy net panels are described. Based on these studies, empirical values for normal drag coefficients are proposed for various types of copper netting. These findings are compared to the previously published data on polymer nets. It is shown that copper nets exhibit significantly lower resistance to normal currents, which corresponds to lower values of normal drag coefficient. The seawater performance (corrosion and biofouling) of copper alloys is studied through the field trials of tensioned and untensioned specimens in a one-year deployment in the North Atlantic Ocean. The corrosion behavior is characterized by weight loss, optical microscopy, and SEM/EDX analyses. The biofouling performance is quantified in terms of the biomass accumulation. To estimate the effects of stray electrical currents on the seawater corrosion measurements, a low cost three-axis stray electric current monitoring device is designed and tested both in the lab and in the 30-day field deployment. The system consists of a remotely operated PC with a set of pseudo-electrodes and a digital compass. The collected data is processed to determine magnitudes of AC and DC components of electric field and dominant AC frequencies. Mechanical behavior of

Prolonged Pulmonary Exposure to Diesel Exhaust Particles Exacerbates Renal Oxidative Stress, Inflammation and DNA Damage in Mice with Adenine-Induced Chronic Renal Failure.

Science.gov (United States)

Nemmar, Abderrahim; Karaca, Turan; Beegam, Sumaya; Yuvaraju, Priya; Yasin, Javed; Hamadi, Naserddine Kamel; Ali, Badreldin H

2016-01-01

Epidemiological evidence indicates that patients with chronic kidney diseases have increased susceptibility to adverse outcomes related to long-term exposure to particulate air pollution. However, mechanisms underlying these effects are not fully understood. Presently, we assessed the effect of prolonged exposure to diesel exhaust particles (DEP) on chronic renal failure induced by adenine (0.25% w/w in feed for 4 weeks), which is known to involve inflammation and oxidative stress. DEP (0.5m/kg) was intratracheally (i.t.) instilled every 4th day for 4 weeks (7 i.t. instillation). Four days following the last exposure to either DEP or saline (control), various renal endpoints were measured. While body weight was decreased, kidney weight increased in DEP+adenine versus saline+adenine or DEP. Water intake, urine volume, relative kidney weight were significantly increased in adenine+DEP versus DEP and adenine+saline versus saline. Plasma creatinine and urea increased and creatinine clearance decreased in adenine+DEP versus DEP and adenine+saline versus saline. Tumor necrosis factor α, lipid peroxidation and reactive oxygen species were significantly increased in adenine+DEP compared with either DEP or adenine+saline. The antioxidant calase was significantly decreased in adenine+DEP compared with either adenine+saline or DEP. Notably, renal DNA damage was significantly potentiated in adenine+DEP compared with either adenine+saline or DEP. Similarly, systolic blood pressure was increased in adenine+DEP versus adenine+saline or DEP, and in DEP versus saline. Histological evaluation revealed more collagen deposition, higher number of necrotic cell counts and dilated tubules, cast formation and collapsing glomeruli in adenine+DEP versus adenine+saline or DEP. Prolonged pulmonary exposure to diesel exhaust particles worsen renal oxidative stress, inflammation and DNA damage in mice with adenine-induced chronic renal failure. Our data provide biological plausibility that air

Hydrostatic pressure and temperature affect the tolerance of the free-living marine nematode Halomonhystera disjuncta to acute copper exposure.

Science.gov (United States)

Mevenkamp, Lisa; Brown, Alastair; Hauton, Chris; Kordas, Anna; Thatje, Sven; Vanreusel, Ann

2017-11-01

Potential deep-sea mineral extraction poses new challenges for ecotoxicological research since little is known about effects of abiotic conditions present in the deep sea on the toxicity of heavy metals. Due to the difficulty of collecting and maintaining deep-sea organisms alive, a first step would be to understand the effects of high hydrostatic pressure and low temperatures on heavy metal toxicity using shallow-water relatives of deep-sea species. Here, we present the results of acute copper toxicity tests on the free-living shallow-water marine nematode Halomonhystera disjuncta, which has close phylogenetic and ecological links to the bathyal species Halomonhystera hermesi. Copper toxicity was assessed using a semi-liquid gellan gum medium at two levels of hydrostatic pressure (0.1MPa and 10MPa) and temperature (10°C and 20°C) in a fully crossed design. Mortality of nematodes in each treatment was assessed at 4 time intervals (24 and 48h for all experiments and additionally 72 and 96h for experiments run at 10°C). LC 50 values ranged between 0.561 and 1.864mg Cu 2+ L -1 and showed a decreasing trend with incubation time. Exposure to high hydrostatic pressure significantly increased sensitivity of nematodes to copper, whereas lower temperature resulted in an apparently increased copper tolerance, possibly as a result of a slower metabolism under low temperatures. These results indicate that hydrostatic pressure and temperature significantly affect metal toxicity and therefore need to be considered in toxicity assessments for deep-sea species. Any application of pollution limits derived from studies of shallow-water species to the deep-sea mining context must be done cautiously, with consideration of the effects of both stressors. Copyright © 2017 Elsevier B.V. All rights reserved.

Swelling of pure copper and copper alloys after high fluence irradiation in FFTF [Fast Flux Test Facility] at approximately 4500C

International Nuclear Information System (INIS)

Garner, F.A.; Brager, H.R.

1986-03-01

The swelling of pure copper and various copper-base alloys has been determined at 47.2 dpa after irradiation in FFTF-MOTA at ∼450 0 C. Data are also becoming available at 63.3 dpa. The alloys tend to fall into two broad categories, those that swell appreciably, sometimes with an S-shaped behavior, and those that resist swelling to very high neutron exposures. It appears that copper may have an intrinsic swelling rate of ∼1%/dpa that is often not reached due to its tendency toward saturation of swelling. The most swelling-resistant alloys examined to date are CuAl25, MZC and Cu-2.0Be

Corrosion of copper and copper alloys in a basaltic repository environment

International Nuclear Information System (INIS)

Brehm, W.F.

1990-01-01

Corrosion testing done on copper and copper alloys in support of the basalt repository program is discussed. Tests were performed under anoxic conditions at 50C, 100C, 150C and 200C in the presence of a saturated basalt-bentonite packing. Tests were also performed in an air/steam mixture at temperatures between 150C and 200C. Some tests, particularly those in air/steam mixtures, were done in the presence of radiation fields of 10 2 , 10 3 or 10 4 rad/h. Exposure periods were up to 28 months. A synthetic groundwater, Grande Ronde ≠4, was used. The materials studied were ASTM B402μm·a for copper and 17 μm·a for cupronickel, but the average rates were muμm·a was obtained. The rates at longer times were less than a third of this value. Corrosion increased monotonically with time and temperature. Chalcocite (Cu 2 S) was the corrosion product at 200C. There was no detectable radiation effect, and no pitting was observed. In air/steam corrosion was uniform with no pitting. Linear corrosion was observed for pure copper. The maximum corrosion penetration after 25 months was 0.13 mm at 300C; cupronickel corroded more slowly, with a maximum penetration of 0.045mm after 25 months. Cuprite (Cu 2 O) and tenorite (CuO) were identified on cupronickel, but only Cu 2 O on copper. A pronounced radiation effect was seen at 250C, but not at 150C; the surface film morphology was different under irradiation. In the short term the presence of packing increased the corrosion rate. 5 refs

Human exposure assessment of silver and copper migrating from an antimicrobial nanocoated packaging material into an acidic food simulant.

Science.gov (United States)

Hannon, Joseph Christopher; Kerry, Joseph P; Cruz-Romero, Malco; Azlin-Hasim, Shafrina; Morris, Michael; Cummins, Enda

2016-09-01

To examine the human exposure to a novel silver and copper nanoparticle (AgNP and CuNP)/polystyrene-polyethylene oxide block copolymer (PS-b-PEO) food packaging coating, the migration of Ag and Cu into 3% acetic acid (3% HAc) food simulant was assessed at 60 °C for 10 days. Significantly lower migration was observed for Ag (0.46 mg/kg food) compared to Cu (0.82 mg/kg food) measured by inductively coupled plasma - atomic emission spectrometry (ICP-AES). In addition, no distinct population of AgNPs or CuNPs were observed in 3% HAc by nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). The predicted human exposure to Ag and Cu was used to calculate a margin of exposure (MOE) for ionic species of Ag and Cu, which indicated the safe use of the food packaging in a hypothetical scenario (e.g. as fruit juice packaging). While migration exceeded regulatory limits, the calculated MOE suggests current migration limits may be conservative for specific nano-packaging applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Presence of Algae Mitigates the Toxicity of Copper-Based Algaecides to a Non-Target Organism.

Science.gov (United States)

Bishop, West M; Willis, Ben E; Richardson, Robert J; Cope, W Gregory

2018-05-07

Copper-based algaecides are routinely applied to target noxious algal blooms in freshwaters. Standard toxicity testing data with copper suggest typical concentrations used to control algae can cause deleterious acute impacts to non-target organisms. These "clean" water experiments lack algae, which are specifically targeted in field applications of algaecides and contain competing ligands. This research measured the influence of algae on algaecide exposure and subsequent response of the non-target species Daphnia magna to copper sulfate and an ethanolamine-chelated copper algaecide (Captain®). Significant shifts (Palgae were present in exposures along with a copper salt or chelated copper formulation. Copper sulfate 48-h LC50 values shifted from 75.3 to 317.8 and 517.8 µg Cu/L whereas Captain increased from 353.8 to 414.2 and 588.5 µg Cu/L in no algae, 5 × 10 5 and 5 × 10 6 cells/mL algae treatments, respectively. Larger shifts were measured with copper sulfate exposures, although Captain was less toxic to Daphnia magna in all corresponding treatments. Captain was more effective at controlling Scenedesmus dimorphus at most concentrations, and control was inversely proportional to toxicity to D. magna. Overall, incorporating target competing ligands (i.e., algae) into standard toxicity testing is important for accurate risk assessment, and copper formulation can significantly alter algaecidal efficacy and risks to non-target organisms. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Pure and Oxidized Copper Materials as Potential Antimicrobial Surfaces for Spaceflight Activities

Science.gov (United States)

Hahn, C.; Hans, M.; Hein, C.; Mancinelli, R. L.; Mücklich, F.; Wirth, R.; Rettberg, P.; Hellweg, C. E.; Moeller, R.

2017-12-01

Microbial biofilms can lead to persistent infections and degrade a variety of materials, and they are notorious for their persistence and resistance to eradication. During long-duration space missions, microbial biofilms present a danger to crew health and spacecraft integrity. The use of antimicrobial surfaces provides an alternative strategy for inhibiting microbial growth and biofilm formation to conventional cleaning procedures and the use of disinfectants. Antimicrobial surfaces contain organic or inorganic compounds, such as antimicrobial peptides or copper and silver, that inhibit microbial growth. The efficacy of wetted oxidized copper layers and pure copper surfaces as antimicrobial agents was tested by applying cultures of Escherichia coli and Staphylococcus cohnii to these metallic surfaces. Stainless steel surfaces were used as non-inhibitory control surfaces. The production of reactive oxygen species and membrane damage increased rapidly within 1 h of exposure on pure copper surfaces, but the effect on cell survival was negligible even after 2 h of exposure. However, longer exposure times of up to 4 h led to a rapid decrease in cell survival, whereby the survival of cells was additionally dependent on the exposed cell density. Finally, the release of metal ions was determined to identify a possible correlation between copper ions in suspension and cell survival. These measurements indicated a steady increase of free copper ions, which were released indirectly by cells presumably through excreted complexing agents. These data indicate that the application of antimicrobial surfaces in spaceflight facilities could improve crew health and mitigate material damage caused by microbial contamination and biofilm formation. Furthermore, the results of this study indicate that cuprous oxide layers were superior to pure copper surfaces related to the antimicrobial effect and that cell density is a significant factor that influences the time dependence of

Effects of copper on growth, metamorphosis and endocrine disruption of Bufo gargarizans larvae.

Science.gov (United States)

Wang, Chao; Liang, Gang; Chai, Lihong; Wang, Hongyuan

2016-01-01

Chinese toad (Bufo gargarizans) tadpoles were exposed to copper (1, 6.4, 32 and 64μgL(-1) copper) from the beginning of larval period through completion of metamorphosis. We examined the effects of chronic copper exposure on mortality, growth, time to metamorphosis, tail resorption time, body size at the metamorphic climax (Gs 42) and completion of metamorphosis (Gs 46) and thyroid gland histology. In addition, type 2 and 3 iodothyronine deiodinase (Dio2 and Dio3), thyroid hormone receptors (TRα and TRβ) mRNA levels were also measured to assess disruption of TH synthesis. Our result showed that 6.4-64μgL(-1) copper concentration increased the mortality and inhibited the growth of B. gargarizans tadpoles. In addition, significant reduction in size at Gs 42 and a time delay to Gs 42 were observed at 6.4-64μgL(-1) copper treatments. Moreover, histological examinations have clearly revealed that 64μgL(-1) copper caused follicular cell hyperplasia in thyroid gland. According to real-time PCR results, exposure to 32 and 64μgL(-1) copper significantly up-regulated mRNA expression of Dio3, but down-regulated mRNA expression of TRα and TRβ mRNA level. We concluded that copper delayed amphibian metamorphosis through changing mRNA expression of Dio3, TRα and TRβ, which suggests that copper might have the endocrine-disrupting effect. Copyright © 2015 Elsevier B.V. All rights reserved.

Biodynamics of copper oxide nanoparticles and copper ions in an oligochaete, Part I

DEFF Research Database (Denmark)

Ramskov, Tina; Thit, Amalie; Croteau, Marie-Noelle

2015-01-01

Copper oxide (CuO) nanoparticles (NPs) are widely used, and likely released into the aquatic environment. Both aqueous (i.e., dissolved Cu) and particulate Cu can be taken up by organisms. However, how exposure routes influence the bioavailability and subsequent toxicity of Cu remains largely...... unknown. Here, we assess the importance of exposure routes (water and sediment) and Cu forms (aqueous and nanoparticulate) on Cu bioavailability and toxicity to the freshwater oligochaete, Lumbriculus variegatus, a head-down deposit-feeder. We characterize the bioaccumulation dynamics of Cu in L....... In nature, L. variegatus is potentially exposed to Cu via both water and sediment. However, sediment progressively becomes the predominant exposure route for Cu in L. variegatus as Cu partitioning to sediment increases...

ROS dependent copper toxicity in Hydra-biochemical and molecular study.

Science.gov (United States)

Zeeshan, Mohammed; Murugadas, Anbazhagan; Ghaskadbi, Surendra; Rajendran, Ramasamy Babu; Akbarsha, Mohammad Abdulkader

2016-01-01

Copper, an essential microelement, is known to be toxic to aquatic life at concentrations higher than that could be tolerated. Copper-induced oxidative stress has been documented in vitro, yet the in vivo effects of metal-induced oxidative stress have not been extensively studied in the lower invertebrates. The objective of the present study has been to find the effect of ROS-mediated toxicity of environmentally relevant concentrations of copper at organismal and cellular levels in Hydra magnipapillata. Exposure to copper at sublethal concentrations (0.06 and 0.1mg/L) for 24 or 48h resulted in generation of significant levels of intracellular reactive oxygen species (ROS). We infer that the free radicals here originate predominantly at the lysosomes but partly at the mitochondria also as visualized by H2-DHCFDA staining. Quantitative real-time PCR of RNA extracted from copper-exposed polyps revealed dose-dependent up-regulation of all antioxidant response genes (CAT, SOD, GPx, GST, GR, G6PD). Concurrent increase of Hsp70 and FoxO genes suggests the ability of polyps to respond to stress, which at 48h was not the same as at 24h. Interestingly, the transcript levels of all genes were down-regulated at 48h as compared to 24h incubation period. Comet assay indicated copper as a powerful genotoxicant, and the DNA damage was dose- as well as duration-dependent. Western blotting of proteins (Bax, Bcl-2 and caspase-3) confirmed ROS-mediated mitochondrial cell death in copper-exposed animals. These changes correlated well with changes in morphology, regeneration and aspects of reproduction. Taken together, the results indicate increased production of intracellular ROS in Hydra on copper exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

Micronized copper wood preservatives: An efficiency and potential health risk assessment for copper-based nanoparticles

International Nuclear Information System (INIS)

Civardi, Chiara; Schwarze, Francis W.M.R.; Wick, Peter

2015-01-01

Copper (Cu) is an essential biocide for wood protection, but fails to protect wood against Cu-tolerant wood-destroying fungi. Recently Cu particles (size range: 1 nm–25 μm) were introduced to the wood preservation market. The new generation of preservatives with Cu-based nanoparticles (Cu-based NPs) is reputedly more efficient against wood-destroying fungi than conventional formulations. Therefore, it has the potential to become one of the largest end uses for wood products worldwide. However, during decomposition of treated wood Cu-based NPs and/or their derivate may accumulate in the mycelium of Cu-tolerant fungi and end up in their spores that are dispersed into the environment. Inhaled Cu-loaded spores can cause harm and could become a potential risk for human health. We collected evidence and discuss the implications of the release of Cu-based NPs by wood-destroying fungi and highlight the exposure pathways and subsequent magnitude of health impact. - Highlights: • We compared copper particulate wood preservatives with conventional ones. • We assessed the fungicidal activity of particulate copper wood preservatives. • We reviewed the Cu-tolerance mechanisms of some wood-destroying fungi. • Fungi colonizing wood treated with particulate copper may release Cu-loaded spores. - We assess the fungicidal activity of particulate copper wood preservatives and their possible release in the air by Cu-tolerant wood-destroying fungi

Corrosion of copper alloys in sulphide containing district heting systems

DEFF Research Database (Denmark)

Thorarinsdottir, R.I.; Maahn, Ernst Emanuel

1999-01-01

Copper and some copper alloys are prone to corrosion in sulphide containing geothermal water analogous to corrosion observed in district heating systems containing sulphide due to sulphate reducing bacteria. In order to study the corrosion of copper alloys under practical conditions a test...... was carried out at four sites in the Reykjavik District Heating System. The geothermal water chemistry is different at each site. The corrosion rate and the amount and chemical composition of deposits on weight loss coupons of six different copper alloys are described after exposure of 12 and 18 months......, respectively. Some major differences in scaling composition and the degree of corrosion attack are observed between alloys and water types....

Corrosion of copper-based materials in gamma radiation

International Nuclear Information System (INIS)

Yunker, W.H.

1986-06-01

The corrosion behaviors of pure copper (CDA 101), 7% aluminum-copper bronze (CDA 613) and 30% nickel-copper (CDA 715) are being studied in a gamma radiation field of 1 x 10 5 R/h. These studies are in support of the Nevada Nuclear Waste Storage Investigations (NNWSI) Project, by Lawrence Livermore National Laboratory (LLNL), of copper-based materials for possible use in container systems for the permanent geologic burial of nuclear waste. Weight loss, tear drop (stressed), and crevice specimens of the three materials were exposed to water vapor-air atmospheres at 95 0 C and 150 0 C and to liquid water at 95 0 C for periods of one, three, and six months. Longer exposures are in progress. Measurements include: changes in the chemical composition of the gas and water, specimen weight changes, oxide film weights, evidence of microcracking and crevice corrosion, and chemical composition of the oxide films by Auger electron spectroscopy and x-ray diffraction. Interim results show considerable pit and under-film corrosion of alloys CDA 613 and CDA 715. Uniform corrosion rates range from 0.012 mil/yr (0.30 μm/yr) to 0.22 mil/yr (5.6 μm/yr), based on specimen weight losses during six- and seven-month exposures. The time dependencies will be determined as more data become available

FEASIBILITY AND EFFECTIVENESS OF DYADIC PROLONGED EXPOSURE INTERVENTION FOR PREVENTING POSTTRAUMATIC GRIEF IN YOUNG CHILDREN: A CASE REPORT OF TWO SIBLINGS.

Science.gov (United States)

Rachamim, Lilach

2017-09-01

This article highlights the feasibility of a dyadic prolonged exposure (DPE) intervention (L. Rachamim, I. Mirochnik, L. Helpman, N. Nacasch, & E. Yadin, ) in a 3-year-old preschooler and in a 6-year-old kindergartener immediately following the traumatic death of their younger sibling. It presents a detailed case description of the DPE treatment addressing traumatic grief and includes transcribed treatment dialogue. At the time of treatment termination, both children and caregivers resumed normal functioning. The results suggest that DPE intervention may ameliorate posttraumatic grief symptoms in young children. Controlled studies of preventive interventions for this population are clearly warranted. © 2017 Michigan Association for Infant Mental Health.

Effects on respiratory homeostasis of prolonged, continuous hyperoxia at 1.5 to 3.0 ATA in man in Predictive Studies V

Science.gov (United States)

Gelfand, R.; Clark, J. M.; Lambertsen, C. J.; Pisarello, J. B.

1987-01-01

Prolonged exposures of men to continuous hyperoxia at 3.0, 2.5, 2.0, and 1.5 ATA were conducted to define CNS oxygen tolerance and to investigate the effects of prolonged hyperoxia on CNS and other organ functions. Altered respiratory homeostasis was evident during exposures of men to 2.5 and 3.0 ATA O2 as nonprogressive increment in ventilation and reciprocal decrement in PET(CO2). These changes were progressive during exposure at 1.5 ATA O2. Mean values of respiratory reactivity at CO2 were somewhat increased following prolonged hyperoxia at 1.5 and 2.5 ATA, compared to preexposure mean values. Hypoxic ventilatory response was unchanged or enhanced after oxygen exposures at 1.5 and 2.5 ATA. Observed respiratory and body temperature changes were not of sufficient magnitude to impair function.

Prolonged sedation and/or analgesia and 5-year neurodevelopment outcome in very preterm infants: results from the EPIPAGE cohort.

Science.gov (United States)

Rozé, Jean-Christophe; Denizot, Sophie; Carbajal, Ricardo; Ancel, Pierre-Yves; Kaminski, Monique; Arnaud, Catherine; Truffert, Patrick; Marret, Stéphane; Matis, Jaqueline; Thiriez, Gérard; Cambonie, Gilles; André, Monique; Larroque, Béatrice; Bréart, Gérard

2008-08-01

To describe the long-term outcome of very preterm infants receiving prolonged sedation and/or analgesia and examine the relationship between prolonged sedation and/or analgesia and this long-term outcome. A prospective population-based study (Etude EPIdémiologique sur les Petits Ages GEstationnels [EPIPAGE]). To reduce bias, the propensity score method was used. Nine regions of France. The study population included very preterm infants of fewer than 33 weeks' gestational age, born in 1997, who received mechanical ventilation and/or surgery. Main Exposure Prolonged exposure to sedative and/or analgesic drugs in the neonatal period, defined as exposure of more than 7 days to sedative and/or opioid drugs. Presence of moderate or severe disability at 5 years of age. The analysis concerns 1572 premature infants who received mechanical ventilation for whom information about exposure to prolonged sedation and/or analgesia in the neonatal period was available. A total of 115 were exposed and 1457 were not exposed. There was no significant difference between the number of patients lost to follow-up from the group of very preterm infants who were exposed to prolonged sedation and/or analgesia and the group who were not. Exposed very preterm infants had severe or moderate disability at 5 years (41/97; 42%) more often than those who were not exposed (324/1248; 26%). After adjustment for gestational age and propensity score, this association was no longer statistically significant (adjusted relative risk, 1.0; 95% confidence interval, 0.8-1.2). Prolonged sedation and/or analgesia is not associated with a poor 5-year neurological outcome after adjustment for the propensity score.

Development of Copper Corrosion Products and Relation between Surface Appearance and Corrosion Rate

International Nuclear Information System (INIS)

Lan, Tran Thi Ngoc; Binh, Nguyen Thi Thanh; Tru, Nguyen Nhi; Yoshino, Tsujino; Yasuki, Maeda

2008-01-01

Copper was exposed unsheltered and sheltered in four humid tropical sites, representing urban, urban-industrial, urban-marine and rural environments. The corrosion rates and the sequence of corrosion product formation are presented and discussed in relation with climatic and atmospheric pollution parameters. Chemical compositions of corrosion products were found to depend on environments and duration of exposure. In all environments, cuprite was the predominating corrosion product that formed first and continuously increased during the exposure. Among the sulphur-containing corrosion products, posnjakite and brochantite were more frequently found and the first formed earlier. Nantokite was the most common chlorine-containing products for most cases, except the high-chloride environment, where atacamite was detected instead. The corrosion rate of copper was well indicated by the colour of patina. The red-purple colour corresponded to the high corrosion rate and the greenish grey colour corresponded to the low corrosion rate. Corrosion rate of sheltered copper in urban-marine environment increased with the exposure time

Subtleties in practical application of prolonged infusion of β-lactam antibiotics.

Science.gov (United States)

De Waele, Jan J; Lipman, Jeffrey; Carlier, Mieke; Roberts, Jason A

2015-05-01

Prolonged infusion (PI) of β-lactam antibiotics is increasingly used in order to optimise antibiotic exposure in critically ill patients. Physicians are often not aware of a number of subtleties that may jeopardise the treatment. In this clinically based paper, we stress pragmatic issues, such as the importance of a loading dose before PI, and discuss a number of important practicalities that are mandatory to benefit from the pharmacokinetic advantages of prolonged β-lactam antibiotic administration. Copyright © 2015 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Ecophysiological tolerance of duckweeds exposed to copper

Energy Technology Data Exchange (ETDEWEB)

Kanoun-Boule, Myriam [Centre for Functional Ecology, Department of Botany, University of Coimbra, Coimbra 3000-456 (Portugal)], E-mail: mkb@ci.uc.pt; Vicente, Joaquim A.F.; Nabais, Cristina [Centre for Functional Ecology, Department of Botany, University of Coimbra, Coimbra 3000-456 (Portugal); Prasad, M.N.V. [Department of Plant Sciences, University of Hyderabad, Hyderabad 500046 (India); Freitas, Helena [Centre for Functional Ecology, Department of Botany, University of Coimbra, Coimbra 3000-456 (Portugal)

2009-01-18

Although essential for plants, copper can be toxic when present in supra-optimal concentrations. Metal polluted sites, due to their extreme conditions, can harbour tolerant species and/or ecotypes. In this work we aimed to compare the physiological responses to copper exposure and the uptake capacities of two species of duckweed, Lemna minor (Lm(EC1)) and Spirodela polyrrhiza (SP), from an abandoned uranium mine with an ecotype of L. minor (Lm(EC2)) from a non-contaminated pond. From the lowest Cu concentration exposure (25 {mu}M) to the highest (100 {mu}M), Lm(EC2) accumulated higher amounts of copper than Lm(EC1) and SP. Dose-response curves showed that Cu content accumulated by Lm(EC2) increases linearly with Cu treatment concentrations (r{sup 2} = 0.998) whereas quadratic models were more suitable for Lm(EC1) and SP (r{sup 2} = 0.999 and r{sup 2} = 0.998 for Lm(EC1) and SP, respectively). A significant concentration-dependent decline of chlorophyll a (chl a) and carotenoid occurred as a consequence of Cu exposure. These declines were significant for Lm(EC2) exposed to the lowest Cu concentration (25 {mu}M) whereas for Lm(EC1) and SP a significant decrease in chl a and carotenoids was observed only at 50 and 100 {mu}M-Cu. Electric conductivity (EC) and malondialdehyde (MDA) content increased after Cu exposure, indicating oxidative stress. Significant increase of EC was observed in Lm(EC2) for all Cu concentrations whereas the increase for Lm(EC1) and SP became significant only after an exposure to 50 {mu}M-Cu. On the contrary, for Lm(EC1), SP, and Lm(EC2), MDA content significantly increased even at the lowest concentration. Protein content and catalase (CAT) activity showed a decrease with an increase in Cu concentration. For the species Lm(EC1) and SP, a significant effect of copper on CAT activity was observed only at the highest concentration (100 {mu}M-Cu) whereas, for Lm(EC2), this effect started to be significant after an exposure to 50 {mu

Ecophysiological tolerance of duckweeds exposed to copper

International Nuclear Information System (INIS)

Kanoun-Boule, Myriam; Vicente, Joaquim A.F.; Nabais, Cristina; Prasad, M.N.V.; Freitas, Helena

2009-01-01

Although essential for plants, copper can be toxic when present in supra-optimal concentrations. Metal polluted sites, due to their extreme conditions, can harbour tolerant species and/or ecotypes. In this work we aimed to compare the physiological responses to copper exposure and the uptake capacities of two species of duckweed, Lemna minor (Lm(EC1)) and Spirodela polyrrhiza (SP), from an abandoned uranium mine with an ecotype of L. minor (Lm(EC2)) from a non-contaminated pond. From the lowest Cu concentration exposure (25 μM) to the highest (100 μM), Lm(EC2) accumulated higher amounts of copper than Lm(EC1) and SP. Dose-response curves showed that Cu content accumulated by Lm(EC2) increases linearly with Cu treatment concentrations (r 2 = 0.998) whereas quadratic models were more suitable for Lm(EC1) and SP (r 2 = 0.999 and r 2 = 0.998 for Lm(EC1) and SP, respectively). A significant concentration-dependent decline of chlorophyll a (chl a) and carotenoid occurred as a consequence of Cu exposure. These declines were significant for Lm(EC2) exposed to the lowest Cu concentration (25 μM) whereas for Lm(EC1) and SP a significant decrease in chl a and carotenoids was observed only at 50 and 100 μM-Cu. Electric conductivity (EC) and malondialdehyde (MDA) content increased after Cu exposure, indicating oxidative stress. Significant increase of EC was observed in Lm(EC2) for all Cu concentrations whereas the increase for Lm(EC1) and SP became significant only after an exposure to 50 μM-Cu. On the contrary, for Lm(EC1), SP, and Lm(EC2), MDA content significantly increased even at the lowest concentration. Protein content and catalase (CAT) activity showed a decrease with an increase in Cu concentration. For the species Lm(EC1) and SP, a significant effect of copper on CAT activity was observed only at the highest concentration (100 μM-Cu) whereas, for Lm(EC2), this effect started to be significant after an exposure to 50 μM-Cu. Superoxide dismutase (SOD) activity

Effect of leucine supplementation on fat free mass with prolonged hypoxic exposure during a 13-day trek to Everest Base Camp: a double-blind randomized study.

Science.gov (United States)

Wing-Gaia, Stacie L; Gershenoff, Dana C; Drummond, Micah J; Askew, E Wayne

2014-03-01

Loss of body weight and fat-free mass (FFM) are commonly noted with prolonged exposure to hypobaric hypoxia. Recent evidence suggests protein supplementation, specifically leucine, may potentially attenuate loss of FFM in subcaloric conditions during normoxia. The purpose of this study was to determine if leucine supplementation would prevent the loss of FFM in subcaloric conditions during prolonged hypoxia. Eighteen physically active male (n = 10) and female (n = 8) trekkers completed a 13-day trek in Nepal to Everest Base Camp with a mean altitude of 4140 m (range 2810-5364 m). In this double-blind study, participants were randomized to ingest either leucine (LEU) (7 g leucine, 93 kcal, 14.5 g whey-based protein) or an isocaloric isonitrogenous control (CON) (0.3 g LEU, 93 kcal, 11.3 g collagen protein) twice daily prior to meals. Body weight, body composition, and circumferences of bicep, thigh, and calf were measured pre- and post-trek. There was a significant time effect for body weight (-2.2% ± 1.7%), FFM (-1.7% ± 1.5%), fat mass (-4.0% ± 6.9%), and circumferences (p FFM (CON -2.1 ± 1.5%; LEU -1.2 ± 1.6%), fat mass (CON -2.9% ± 5.9%; LEU -5.4% ± 8.1%), or circumferences. Although a significant loss of body weight, FFM, and fat mass was noted in 13 days of high altitude exposure, FFM loss was not attenuated by leucine. Future studies are needed to determine if leucine attenuates loss of FFM with longer duration high altitude exposure.

Evaluation of biocidal efficacy of copper alloy coatings in comparison with solid metal surfaces: generation of organic copper phosphate nanoflowers.

Science.gov (United States)

Gutierrez, H; Portman, T; Pershin, V; Ringuette, M

2013-03-01

To analyse the biocidal efficacy of thermal sprayed copper surfaces. Copper alloy sheet metals containing >60% copper have been shown to exhibit potent biocidal activity. Surface biocidal activity was assessed by epifluorescence microscopy. After 2-h exposure at 20 °C in phosphate-buffered saline (PBS), contact killing of Gram-negative Escherichia coli and Gram-positive Staphylococcus epidermidis by brass sheet metal and phosphor bronze was 3-4-times higher than that by stainless steel. SEM observations revealed that the surface membranes of both bacterial strains were slightly more irregular when exposed to brass sheet metal than stainless steel. However, when exposed to phosphor bronze coating, E. coli were 3-4 times larger with irregular membrane morphology. In addition, the majority of the cells were associated with spherical carbon-copper-phosphate crystalline nanostructures characteristic of nanoflowers. The membranes of many of the S. epidermidis exhibited blebbing, and a small subset was also associated with nanoflowers. Our data indicate that increasing the surface roughness of copper alloys had a pronounced impact on the membrane integrity of Gram-positive and, to a lesser degree, Gram-negative bacteria. In the presence of PBS, carbon-copper-phosphate-containing nanoflowers were formed, likely nucleated by components derived from killed bacteria. The intimate association of the bacteria with the nanoflowers and phosphor bronze coating likely contributed to their nonreversible adhesion. Thermal spraying of copper alloys provides a strategy for the rapid coating of three-dimensional organic and inorganic surfaces with biocidal copper alloys. Our study demonstrates that the macroscale surface roughness generated by the thermal spray process enhances the biocidal activity of copper alloys compared with the nanoscale surface roughness of copper sheet metals. Moreover, the coating surface topography provides conditions for the rapid formation of organic copper

Weight loss studies of fastener materials corrosion in contact with timbers treated with copper azole and alkaline copper quaternary compounds

Energy Technology Data Exchange (ETDEWEB)

Kear, Gareth [Building Research Association of New Zealand (BRANZ) Ltd., Science and Engineering Services, Private Bag 50 908, Porirua City 5240 (New Zealand)], E-mail: G.Kear@soton.ac.uk; Wu Haizhen; Jones, Mark S. [Building Research Association of New Zealand (BRANZ) Ltd., Science and Engineering Services, Private Bag 50 908, Porirua City 5240 (New Zealand)

2009-02-15

Corrosion rates of mild steel, AISI 316 stainless steel and hot-dipped galvanised steel in contact with preservative-treated Pinus radiata have been determined using four distinct accelerated (49 {+-} 1 deg. C) and non-accelerated (21 {+-} 2 deg. C) weight loss methodologies. The data were measured as a function of timber moisture content and copper concentration over periods of exposure ranging from 2 weeks to 14 months. The results show that the corrosion resistance of the stainless steel was not influenced by classification or magnitude of preservative loading. Corrosion rates of this material were multiple orders of magnitude lower than those of the mild and galvanised steels. In most instances, corrosion rates of hot-dipped galvanised layers in contact with alkaline copper quaternary-treated timbers were up to a factor of 10 times, or greater, than those measured for copper-chrome-arsenate treatments. A direct negative influence of copper ion concentration on the corrosion resistance of mild steel was also observed for each preservative type.

Characterization of copper oxides, iron oxides, and zinc copper ferrite desulfurization sorbents by X-ray photoelectron spectroscopy and scanning electron microscopy

Science.gov (United States)

Siriwardane, Ranjani V.; Poston, James A.

1993-05-01

Characterization of copper oxides, iron oxides, and zinc copper ferrite desulfurization sorbents was performed by X-ray photoelectron spectroscopy and scanning electron microscopy/energy-dispersive spectroscopy at temperatures of 298 to 823 K. Analysis of copper oxides indicated that the satellite structure of the Cu22p region was absent in the Cu(I) state but was present in the Cu(II) state. Reduction of CuO at room temperature was observed when the ion gauge was placed close to the sample. The satellite structure was absent in all the copper oxides at 823 K in vacuum. Differentiation of the oxidation state of copper utilizing both Cu(L 3M 4,5M 4,5) X-ray-induced Auger lines and Cu2p satellite structure, indicated that the copper in zinc copper ferrite was in the + 1 oxidation state at 823 K. This + 1 state of copper was not significantly changed after exposure to H 2, CO, and H 2O. There was an increase in Cu/Zn ratio and a decrease in Fe/Zn ratio on the surface of zinc copper ferrite at 823 K compared to that at room temperature. These conditions of copper offered the best sulfidation equilibrium for the zinc copper ferrite desulfurization sorbent. Analysis of iron oxides indicated that there was some reduction of both Fe 2O 3 and FeO at 823K. The iron in zinc copper ferrite was similar to that of Fe 2O 3 at room temperature but there was some reduction of this Fe(III) state to Fe(II) at 823 K. This reduction was more enhanced in the presence of H 2 and CO. Reduction to Fe(II) may not be desirable for the lifetime of the sorbent.

Within- and among-population level differences in response to chronic copper exposure in southern toads, Anaxyrus terrestris

International Nuclear Information System (INIS)

Lance, Stacey L.; Flynn, R. Wesley; Erickson, Matthew R.; Scott, David E.

2013-01-01

Environmental contaminants are implicated in the global decline of amphibian populations. Copper (Cu) is a widespread contaminant that can be toxic at concentrations just above the normal physiological range. In the present study we examined the effects of chronic Cu aqueous exposure on embryos and larvae of southern toads, Anaxyrus (Bufo) terrestris. Measurable levels of Cu were found in larvae, with tissue concentrations up to 27.5 μg Cu/g dry mass. Aqueous concentrations of Cu as low as 10 μg/L significantly reduced survival to the free-swimming stage and no larvae reached metamorphosis at concentrations above 15 μg/L. Clutches from populations with prior Cu exposure had the lowest survivorship. Among several populations there was significant variation in survivorship at different levels of Cu. More data are needed to understand the underlying causes of within- and among-population resilience to anthropogenic stressors. -- Highlights: ► Southern toad, Anaxyrus terrestris, embryos and larvae are highly sensitive to Cu. ► Significant variation in survivorship exists among clutches and populations. ► Clutches with prior Cu exposure had the lowest survivorship. ► Body burdens in larvae were up to 27.5 μg Cu/g dry mass. -- Capsule: Southern toad aquatic survival is significantly reduced at 15 μg Cu/L with variation in survivorship across clutches and populations

The influence of salinity on copper accumulation and its toxic effects in estuarine animals with differing osmoregulatory strategies.

Science.gov (United States)

Lee, Jacqueline A; Marsden, Islay D; Glover, Chris N

2010-08-01

Copper is an important ionoregulatory toxicant in freshwater, but its effects in marine and brackish water systems are less well characterised. The effect of salinity on short-term copper accumulation and sublethal toxicity in two estuarine animals was investigated. The osmoregulating crab Hemigrapsus crenulatus accumulated copper in a concentration-dependent, but salinity-independent manner. Branchial copper accumulation correlated positively with branchial sodium accumulation. Sublethal effects of copper were most prevalent in 125% seawater, with a significant increase in haemolymph chloride noted after 96h at exposure levels of 510 microg Cu(II) L(-1). The osmoconforming gastropod, Scutus breviculus, was highly sensitive to copper exposure, a characteristic recognised previously in related species. Toxicity, as determined by a behavioural index, was present at all salinities and was positively correlated with branchial copper accumulation. At 100% seawater, increased branchial sodium accumulation, decreased haemolymph chloride and decreased haemolymph osmolarity were observed after 48h exposure to 221 microg Cu(II) L(-1), suggesting a mechanism of toxicity related to ionoregulation. However, these effects were likely secondary to a general effect on gill barrier function, and possibly mediated by mucus secretion. Significant impacts of copper on haemocyanin were also noted in both animals, highlighting a potentially novel mechanism of copper toxicity to animals utilising this respiratory pigment. Overall these findings indicate that physiology, as opposed to water chemistry, exerts the greatest influence over copper toxicity. An understanding of the physiological limits of marine and estuarine organisms may be critical for calibration of predictive models of metal toxicity in waters of high and fluctuating salinities. Copyright 2010 Elsevier B.V. All rights reserved.

Computer mouse use predicts acute pain but not prolonged or chronic pain in the neck and shoulder

DEFF Research Database (Denmark)

Andersen, Johan Hviid; Harhoff, Mette; Grimstrup, Søren

2007-01-01

BACKGROUND: Computer use is one of the commonest work place exposures in modern society. An adverse effect on musculoskeletal outcomes has been claimed for decades, mainly on the basis of self reports of exposure. The purpose of this study was to assess the risk of neck and shoulder pain associat...... psychosocial factors predicted the risk of prolonged pain. CONCLUSIONS: From the NUDATA-study we can conclude that most computer workers have no or minor neck and shoulder pain, few experience prolonged pain, and even fewer, chronic neck and shoulder pain....

The toxicity of copper to crucian carp (Carassius carassius) in soft water

Energy Technology Data Exchange (ETDEWEB)

Schjolden, Joachim [Department of Basic Sciences and Aquatic Medicine, Norwegian School of Veterinary Science, P.O. Box 8146 Dep, Ullevalsveien 72, N-0033, Oslo (Norway); Sorensen, Jorgen [Department of Biology, University of Oslo, P.O. Box 1066, Blindern, N-0316, Oslo (Norway); Nilsson, Goeran E. [Department of Molecular Biosciences, University of Oslo, P.O. Box 1041 Blindern, N-0316 Oslo (Norway); Poleo, Antonio B.S. [Department of Biology, University of Oslo, P.O. Box 1066, Blindern, N-0316, Oslo (Norway)], E-mail: toni.poleo@bio.uio.no

2007-10-01

Crucian carp (Carassius carassius) were exposed to a Cu rich medium (pH 6.6, conductivity 25 {mu}S/cm, 2.91 mg Ca{sup 2+}/l, approximately 300 {mu}g Cu{sup 2+}/l). Untreated department water (pH 6.6, conductivity 25 {mu}S/cm, 2.91 mg Ca{sup 2+}/l) acted as control. Mortality in crucian carp was first observed after 13 days of exposure to the Cu rich medium. There were, however, significant changes in haematocrit, plasma chloride, plasma sodium and water content in muscle in fish exposed to the Cu rich medium after two days. After 14 days of exposure to copper, haematocrit increased to 52 {+-} 2% (control: between 37 and 40%), plasma chloride decreased to 45 {+-} 5 mmol/l (control: 99-106 mmol/l), plasma sodium decreased to 81 {+-} 6 mmol/l (control: 116-137 mmol/l), and water content in muscle increased to 83.0 {+-} 0.3% (control: 78.7-79.9%). No apparent changes in blood ethanol, and minor changes in plasma lactate were observed in copper exposed fish. Analyses of the gills revealed an increasing concentration of copper on the gills from fish exposed to Cu rich water. After 14 days, the concentration of copper accumulated in the gill was 12.8 {+-} 4.1 {mu}g Cu/g wet weight (control: 0.91-1.19 {mu}g Cu/g wet weight). A reduction of the respiratory area in fish exposed to copper was observed, in terms of both lamellar and filamental fusion. The normoxic O{sub 2} uptake did not change, but the critical oxygen tension was elevated to 6.12 {+-} 1.04 mg O{sub 2}/l after a 6 day exposure to copper (control: 1.03 {+-} 0.05 mg O{sub 2}/l). This study shows that crucian carp has a higher tolerance to copper compared to other freshwater fish species. Our results suggest that this tolerance is based on the ability of crucian carp to avoid becoming hypoxic as well as an extreme tolerance to severe loss of plasma ions.

Fatigue performance of copper and copper alloys before and after irradiation with fission neutrons

International Nuclear Information System (INIS)

Singh, B.N.; Toft, P.; Stubbins, J.F.

1997-05-01

The fatigue performance of pure copper of the oxygen free, high conductivity (OFHC) grade and two copper alloys (CuCrZr and CuAl-25) was investigated. Mechanical testing and microstructural analysis were carried out to establish the fatigue life of these materials in the unirradiated and irradiated states. The present report provides the first information on the ability of these copper alloys to perform under cyclic loading conditions when they have undergone significant irradiation exposure. Fatigue specimens of OFHC-Cu, CuCrZr and CuAl-25 were irradiated with fission neutrons in the DR-3 reactor at Risoe with a flux of ∼2.5 x 10 17 n/m 2 s (E > 1 MeV) to fluence levels of 1.5 - 2.5 x 10 24 n/m 2 s (E > 1 MeV) at ∼47 and 100 deg. C. Specimens irradiated at 47 deg. C were fatigue tested at 22 deg. C, whereas those irradiated at 100 deg. C were tested at the irradiation temperature. The major conclusion of the present work is that although irradiation causes significant hardening of copper and copper alloys, it does not appear to be a problem for the fatigue life of these materials. In fact, the present experimental results clearly demonstrate that the fatigue performance of the irradiated CuAl-25 alloy is considerably better in the irradiated than that in the unirradiated state tested both at 22 and 100 deg. C. This improvement, however, is not so significant in the case of the irradiated OFHC-copper and CuCrZr alloy tested at 22 deg. C. These conclusions are supported by the microstructural observations and cyclic hardening experiments. (au) 4 tabs., 26 ills., 10 refs

DNA methyltransferases and stress-related genes expression in zebrafish larvae after exposure to heat and copper during reprogramming of DNA methylation.

Science.gov (United States)

Dorts, Jennifer; Falisse, Elodie; Schoofs, Emilie; Flamion, Enora; Kestemont, Patrick; Silvestre, Frédéric

2016-10-12

DNA methylation, a well-studied epigenetic mark, is important for gene regulation in adulthood and for development. Using genetic and epigenetic approaches, the present study aimed at evaluating the effects of heat stress and copper exposure during zebrafish early embryogenesis when patterns of DNA methylation are being established, a process called reprogramming. Embryos were exposed to 325 μg Cu/L from fertilization (<1 h post fertilization - hpf) to 4 hpf at either 26.5 °C or 34 °C, followed by incubation in clean water at 26.5 °C till 96 hpf. Significant increased mortality rates and delayed hatching were observed following exposure to combined high temperature and Cu. Secondly, both stressors, alone or in combination, significantly upregulated the expression of de novo DNA methyltransferase genes (dnmt3) along with no differences in global cytosine methylation level. Finally, Cu exposure significantly increased the expression of metallothionein (mt2) and heat shock protein (hsp70), the latter being also increased following exposure to high temperature. These results highlighted the sensitivity of early embryogenesis and more precisely of the reprogramming period to environmental challenges, in a realistic situation of combined stressors.

Abundance and diversity of culturable Pseudomonas constitute sensitive indicators for adverse long-term copper impacts in soil

DEFF Research Database (Denmark)

Thorsen, Maja Kristine; Brandt, Kristian Koefoed; Nybroe, Ole

2013-01-01

heterotrophic bacteria. This indicates that the Pseudomonas population is not resilient towards copper stress and that culturable Pseudomonas spp. comprise sensitive bio-indicators of adverse copper impacts in contaminated soils. Further this study shows that copper exposure decreases bacterial diversity...

A climate signal in exhumation patterns revealed by porphyry copper deposits

Science.gov (United States)

Yanites, Brian J.; Kesler, Stephen E.

2015-06-01

The processes that build and shape mountain landscapes expose important mineral resources. Mountain landscapes are widely thought to result from the interaction between tectonic uplift and exhumation by erosion. Both climate and tectonics affect rates of exhumation, but estimates of their relative importance vary. Porphyry copper deposits are emplaced at a depth of about 2 km in convergent tectonic settings; their exposure at the surface therefore can be used to track landscape exhumation. Here we analyse the distribution, ages and spatial density of exposed Cenozoic porphyry copper deposits using a global data set to quantify exhumation. We find that the deposits exhibit young ages and are sparsely distributed--both consistent with rapid exhumation--in regions with high precipitation, and deposits are older and more abundant in dry regions. This suggests that climate is driving erosion and mineral exposure in deposit-bearing mountain landscapes. Our findings show that the emplacement ages of porphyry copper deposits provide a means to estimate long-term exhumation rates in active orogens, and we conclude that climate-driven exhumation influences the age and abundance of exposed porphyry copper deposits around the world.

Copper accumulation by stickleback nests containing spiggin.

Science.gov (United States)

Pinho, G L L; Martins, C M G; Barber, I

2016-07-01

The three-spined stickleback is a ubiquitous fish of marine, brackish and freshwater ecosystems across the Northern hemisphere that presents intermediate sensitivity to copper. Male sticklebacks display a range of elaborate reproductive behaviours that include nest construction. To build the nests, each male binds nesting material together using an endogenous glycoprotein nesting glue, known as 'spiggin'. Spiggin is a cysteine-rich protein and, therefore, potentially binds heavy metals present in the environment. The aim of this study was to investigate the capacity of stickleback nests to accumulate copper from environmental sources. Newly built nests, constructed by male fish from polyester threads in laboratory aquaria, were immersed in copper solutions ranging in concentration from 21.1-626.6 μg Cu L(-1). Bundles of polyester threads from aquaria without male fish were also immersed in the same copper solutions. After immersion, nests presented higher amounts of copper than the thread bundles, indicating a higher capacity of nests to bind this metal. A significant, positive correlation between the concentration of copper in the exposure solution and in the exposed nests was identified, but there was no such relationship for thread bundles. Since both spiggin synthesis and male courtship behaviour are under the control of circulating androgens, we predicted that males with high courtship scores would produce and secrete high levels of the spiggin protein. In the present study, nests built by high courtship score males accumulated more copper than those built by low courtship score males. Considering the potential of spiggin to bind metals, the positive relationship between fish courtship and spiggin secretion seems to explain the higher amount of copper on the nests from the fish showing high behaviour scores. Further work is now needed to determine the consequences of the copper binding potential of spiggin in stickleback nests for the health and survival of

Advanced hair damage model from ultra-violet radiation in the presence of copper.

Science.gov (United States)

Marsh, J M; Davis, M G; Flagler, M J; Sun, Y; Chaudhary, T; Mamak, M; McComb, D W; Williams, R E A; Greis, K D; Rubio, L; Coderch, L

2015-10-01

Damage to hair from UV exposure has been well reported in the literature and is known to be a highly complex process involving initiation via absorption of UV light followed by formation and propagation of reactive oxygen species (ROS). The objective of this work was to understand these mechanisms, explain the role of copper in accelerating the formation of ROS and identify strategies to reduce the hair damage caused by these reactive species. The location of copper in hair was measured by Transmission electron microscopy-(TEM) X-ray energy dispersive spectroscopy (XEDS) and levels measured by ICP-OES. Protein changes were measured as total protein loss via the Lowry assay, and MALDI ToF was used to identify the biomarker protein fragments. TBARS assay was used to measure lipid peroxide formation. Sensory methods and dry combing friction were used to measure hair damage due to copper and UV exposure and to demonstrate the efficacy of N,N' ethylenediamine disuccinic acid (EDDS) and histidine chelants to reduce this damage. In this work, a biomarker protein fragment formed during UV exposure is identified using mass spectrometry. This fragment originates from the calcium-binding protein S100A3. Also shown is the accelerated formation of this peptide fragment in hair containing low levels of copper absorbed from hair during washing with tap water containing copper ions. Transmission electron microscopy (TEM) X-ray energy dispersive spectroscopy (XEDS) studies indicate copper is located in the sulphur-poor endo-cuticle region, a region where the S100A3 protein is concentrated. A mechanism for formation of this peptide fragment is proposed in addition to the possible role of lipids in UV oxidation. A shampoo and conditioner containing chelants (EDDS in shampoo and histidine in conditioner) is shown to reduce copper uptake from tap water and reduce protein loss and formation of S100A3 protein fragment. In addition, the long-term consequences of UV oxidation and

Surface films and corrosion of copper

International Nuclear Information System (INIS)

Hilden, J.; Laitinen, T.; Maekelae, K.; Saario, T.; Bojinov, M.

1999-03-01

properties. The thin outer layer controls the corrosion properties of copper, corrosion rate being limited by ionic transport through the layer and the charge transfer step of the film dissolution. Chlorides cause a breakdown of the oxide film in the stability region of divalent copper, but they seem to have no effect on the properties of the film in the stability region of monovalent copper; oxidising conditions with simultaneous exposure to chlorides are thus expected to subject copper to localised corrosion. Sulphides at the concentration of 10 ppm dissolved H 2 S were found not to promote the formation of a three-dimensional film of Cu 2 S (or other copper sulphides), thus the mechanisms of localised corrosion which operate under reducing conditions and are based on the formation of copper sulphides seem not to be valid. In the presence of 10 ppm H 2 S the corrosion rate of copper is controlled by the charge transfer step of the dissolution of the outer layer

Biokinetics of copper in black-banded rainbowfish (Melanotaenia nigrans) tolerant to elevated copper concentrations, using the radioisotope 64Cu

International Nuclear Information System (INIS)

Gale, S.; Jeffree, R.; Smith, S.; Lim, R.

2000-01-01

Full text: For over 40 years black-banded rainbowfish (Melanotaenia nigrans) living in the East Branch of the Finniss River, Northern Territory have been exposed to elevated copper concentrations due to mine waste from the Rum Jungle uranium/copper mine. In the 1970s prior to remediation of the mine, fish kills were observed along the length of the East Branch. While copper concentrations remain comparatively high (up to 2000 μg/L) in the East Branch since remediation of the mine site, M. nigrans have been observed in the area. It was, therefore, hypothesised that due to selective pressure of lethal exposure, the population of black-banded rainbowfish in the East Branch have developed a tolerance to elevated copper concentrations. This project aimed to demonstrate copper tolerance and evaluate possible mechanism(s). In May 2000, fish were collected from the East Branch (exposed fish) and from a catchment previously unexposed to elevated metal concentrations (reference fish). The 96-hour EC 50 , fish imbalance (i.e. the concentration of copper that affects 50% of fish over 96 hours) for the exposed fish was over 8 times higher than the reference fish. Using the radioisotope, 64 Cu, the biokinetics of newly accumulated copper was traced in exposed and reference fish at low and elevated copper concentrations. The uptake rate, and therefore body burden, were significantly (p=0.000) lower in exposed fish, at both low and elevated copper concentrations compared to reference fish. Possible mechanisms of reducing copper uptake will be discussed. Tolerance was not lost when fish were maintained in relatively low copper concentrations in the laboratory. Also, the two populations of fish were genetically dissimilar based on allozyme analysis, which suggests that the mechanism is genetically mediated. The outcome of this project will be important in assisting accurate risk assessment and the development of environmental management strategies for the conservation of biota. The

Response of the Mediterranean sponge Chondrosia reniformis Nardo to copper pollution

International Nuclear Information System (INIS)

Cebrian, E.; Agell, G.; Marti, R.; Uriz, M.J.

2006-01-01

We examined the effects of exposure to copper pollution on the Atlanto-Mediterranean sponge Chondrosia reniformis. We transplanted sponges from an unpolluted control area to a harbour with a moderately high concentration of copper and measured several biological sponge variables. No effect of this habitat was detected on sponge growth, shape, heat-shock protein expression or metal accumulation. However, a decrease in the clearance rate, an increase in the collagen/cell rate (due to a decrease in the cellular components) and a lower survival rate after 4 months of the sponges transplanted to the harbour was observed. We suggest that copper may alter the sponge physiology, by reducing pumping capacity, which may ultimately lead to sponge death. Consequently, copper pollution exerts strong negative effects on this organism. - Contrasting effects of copper pollution on the Atlanto-Mediterranean sponge Chondrosia reniformis

Copper in household drinking water in the city of Zagreb, Croatia.

Science.gov (United States)

Pizent, Alica; Butković, Sanja

2010-09-01

Copper concentration was estimated in tap water samples obtained from 70 households in Zagreb, serviced by a public water supply system. First-draw and flushed samples of tap water were collected in the morning and total copper concentration was determined by graphite furnace atomic absorption spectrometry with Zeeman-effect background correction. We also estimated the contribution of plumbing material to copper concentrations in tap water. In households with copper pipes, median and range copper values were 310 μg L-1 [(27 to 632) μg L-1] in first-draw samples and 16 μg L-1 [(5 to 52) μg L-1] in flushed samples. Corresponding values for households with galvanised pipes were 140 μg L-1 [(11 to 289) μg L-1] and 8 μg L-1 [(1 to 42) μg L-1], respectively. Copper concentrations in household tap water in Zagreb were far below the proposed safe limits set by the Croatian and WHO regulations and EPA standards, and drinking water in Zagreb is not a significant source of copper exposure.

Metavanadate causes cellular accumulation of copper and decreased lysyl oxidase activity

International Nuclear Information System (INIS)

Cui, Changtai T.; Uriu-Adams, Janet Y.; Tchaparian, Eskouhie H.; Keen, Carl L.; Rucker, Robert B.

2004-01-01

Selected indices of copper metabolism in weanling rats and fibroblast cultures were progressively altered in response to increased levels of sodium metavanadate. In diets, vanadium was added in amounts ranging from 0 to 80 μg V/g of diet, that is, 0-1.6 μmol V/g of diet. In fibroblast cultures, vanadium ranged from 0 to 400 nmol V/ml. The inhibition of P-ATPase-7A activity by metavanadate, important to copper egress from cells, was a primary focus. In skin, and tendon, the copper concentration was increased in response to increased dietary levels of metavanadate, whereas lysyl oxidase activity, a secreted cuproprotein, was reduced. The reduction in lysyl oxidase activity was also accompanied by reduced redox cycling potential of isolated fractions of lysyl oxidase, presumably due to reduced lysyltyrosyl quinone (LTQ) formation at the active site of lysyl oxidase. In contrast, liver copper concentrations and plasma ceruloplasmin activity were not affected by metavanadate exposure. However, semicarbazide-sensitive benzylamine oxidase (SCBO) activity, which was taken as an indirect measure of vascular adhesive protein-1 (VAP-1), was increased. In cultured fibroblasts, cellular copper was also increased and lysyl oxidase decreased in response to metavanadate. Moreover, the steady-state levels of atp7a and lysyl oxidase mRNAs were not affected by addition of metavanadate to culture medium up to 200 nmol/ml. Taken together, these data suggest that pathways involving copper egress and lysyl oxidase activation are particularly sensitive to metavanadate exposure through processes that are predominately posttranslational

Copper and Copper Proteins in Parkinson's Disease

Science.gov (United States)

Rivera-Mancia, Susana; Diaz-Ruiz, Araceli; Tristan-Lopez, Luis; Rios, Camilo

2014-01-01

Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson's disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson's disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased protein-bound copper in brain may enhance iron accumulation and the associated oxidative stress. The function of other copper-binding proteins such as Cu/Zn-SOD and metallothioneins is also beneficial to prevent neurodegeneration. Copper may regulate neurotransmission since it is released after neuronal stimulus and the metal is able to modulate the function of NMDA and GABA A receptors. Some of the proteins involved in copper transport are the transporters CTR1, ATP7A, and ATP7B and the chaperone ATOX1. There is limited information about the role of those biomolecules in the pathophysiology of Parkinson's disease; for instance, it is known that CTR1 is decreased in substantia nigra pars compacta in Parkinson's disease and that a mutation in ATP7B could be associated with Parkinson's disease. Regarding copper-related therapies, copper supplementation can represent a plausible alternative, while copper chelation may even aggravate the pathology. PMID:24672633

Copper interacts with nonylphenol to cancel the effect of nonylphenol on fish chemosensory behaviour.

Science.gov (United States)

Ward, Ashley J W; Thistle, Maria; Ghandi, Khashayar; Currie, Suzanne

2013-10-15

The majority of ecotoxicological studies have been concerned with responses of organisms to a single contaminant. While this approach remains valid, the challenge now is to understand the way in which multiple contaminants and stressors interact to produce effects in study organisms. Here we take an integrated biological and physico-chemical approach to understand the effects of 4-nonylphenol and copper on fish (white perch, Morone americana) chemosensory behaviour. We show that a one hour exposure to 2 μg L(-1) nonylphenol removes chemosensory attraction to conspecific chemical cues, while exposure to 5 μg L(-1) copper for one hour had no significant effect on the fish's attraction to these cues. Further, we show that simultaneous exposure to both contaminants at the stated dosage and for the same duration has no significant effect on the chemosensory attraction of white perch to conspecific chemical cues suggesting that copper mediates the effect of nonylphenol on fish in this respect. Physico-chemical data show that copper ions bind to nonylphenol in water, providing a mechanistic explanation for this change in the effect of nonylphenol. Furthermore, the finding that the copper ions bind to the lone pair of O on the nonylphenol molecule offers the tantalising possibility that it is this region of the nonylphenol molecule that plays the key role in disrupting fish chemical communication. Copyright © 2013 Elsevier B.V. All rights reserved.

Separation of copper-64 from copper phthalocyanine

International Nuclear Information System (INIS)

Battaglin, R.I.M.

1979-01-01

The separation of copper-64 from irradiated copper phthalocyanine by Szilard-Chalmers effect is studied. Two methods of separation are used: one of them is based on the dissolution of the irradiated dry compound in concentrated sulfuric acid following its precipitation in water. In the other one the compound is irradiated with water in paste form following treatment with water and hydrochloric acid. The influence of the crystal form of the copper phthalocyanine on the separation yield of copper-64 is shown. Preliminary tests using the ionic exchange technique for purification and changing of copper-64 sulfate to chloride form are carried out. The specific activity using the spectrophotometric technique, after the determination of the copper concentration in solution of copper-64, is calculated. (Author) [pt

XPS studies of short pulse laser interaction with copper

International Nuclear Information System (INIS)

Stefanov, P.; Minkovski, N.; Balchev, I.; Avramova, I.; Sabotinov, N.; Marinova, Ts.

2006-01-01

The effect of laser ablation on copper foil irradiated by a short 30 ns laser pulse was investigated by X-ray photoelectron spectroscopy. The laser fluence was varied from 8 to 16.5 J/cm 2 and the velocity of the laser beam from 10 to 100 mm/s. This range of laser fluence is characterized by a different intensity of laser ablation. The experiments were done in two kinds of ambient atmosphere: air and argon jet gas. The chemical state and composition of the irradiated copper surface were determined using the modified Auger parameter (α') and O/Cu intensity ratio. The ablation atmosphere was found to influence the size and chemical state of the copper particles deposited from the vapor plume. During irradiation in air atmosphere the copper nanoparticles react with oxygen and water vapor from the air and are deposited in the form of a CuO and Cu(OH) 2 thin film. In argon atmosphere the processed copper surface is oxidized after exposure to air

Grain boundary corrosion of copper canister weld material

International Nuclear Information System (INIS)

Gubner, Rolf; Andersson, Urban; Linder, Mats; Nazarov, Andrej; Taxen, Claes

2006-01-01

The proposed design for a final repository for spent fuel and other long-lived residues in Sweden is based on the multi-barrier principle. The waste will be encapsulated in sealed cylindrical canisters, which will then be placed in granite bedrock and surrounded by compacted bentonite clay. The canister design is based on a thick cast inner container fitted inside a corrosion-resistant copper canister. During fabrication of the outer copper canisters there will be some unavoidable grain growth in the welded areas. As grains grow, they will tend to concentrate impurities within the copper at the new grain boundaries. The work described in this report was undertaken to determine whether there is any possibility of enhanced corrosion at grain boundaries within the copper canister, based on the recommendations of the report SKB-TR--01-09 (INIS ref. 32025363). Grain boundary corrosion of copper is not expected to be a problem for the copper canisters in a repository. However, as one step in the experimental verification it is necessary to study grain boundary corrosion of copper in an environment where it may occur. A literature study aimed to find one or several solutions that are aggressive with respect to grain boundary corrosion of copper. Copper specimens cut from welds of real copper canisters where exposed to aerated ammonium hydroxide solution for a period of 14 days at 80 degrees C and 10 bar pressure. The samples were investigated prior to exposure using the scanning Kelvin probe technique to characterize anodic and cathodic areas on the samples. The degree of corrosion was determined by optical microscopy. No grain boundary corrosion could be observed in the autoclave experiments, however, a higher rate of corrosion was observed for the weld material compared to the base material. The work suggests that grain boundary corrosion of copper weld material is most unlikely to adversely affect SKB's copper canisters under the conditions in the repository

Grain boundary corrosion of copper canister weld material

Energy Technology Data Exchange (ETDEWEB)

Gubner, Rolf; Andersson, Urban; Linder, Mats; Nazarov, Andrej; Taxen, Claes [Corrosion and Metals Research Inst. (KIMAB), Stockholm (Sweden)

2006-01-15

The proposed design for a final repository for spent fuel and other long-lived residues in Sweden is based on the multi-barrier principle. The waste will be encapsulated in sealed cylindrical canisters, which will then be placed in granite bedrock and surrounded by compacted bentonite clay. The canister design is based on a thick cast inner container fitted inside a corrosion-resistant copper canister. During fabrication of the outer copper canisters there will be some unavoidable grain growth in the welded areas. As grains grow, they will tend to concentrate impurities within the copper at the new grain boundaries. The work described in this report was undertaken to determine whether there is any possibility of enhanced corrosion at grain boundaries within the copper canister, based on the recommendations of the report SKB-TR--01-09 (INIS ref. 32025363). Grain boundary corrosion of copper is not expected to be a problem for the copper canisters in a repository. However, as one step in the experimental verification it is necessary to study grain boundary corrosion of copper in an environment where it may occur. A literature study aimed to find one or several solutions that are aggressive with respect to grain boundary corrosion of copper. Copper specimens cut from welds of real copper canisters where exposed to aerated ammonium hydroxide solution for a period of 14 days at 80 degrees C and 10 bar pressure. The samples were investigated prior to exposure using the scanning Kelvin probe technique to characterize anodic and cathodic areas on the samples. The degree of corrosion was determined by optical microscopy. No grain boundary corrosion could be observed in the autoclave experiments, however, a higher rate of corrosion was observed for the weld material compared to the base material. The work suggests that grain boundary corrosion of copper weld material is most unlikely to adversely affect SKB's copper canisters under the conditions in the repository.

In vitro studies of copper release from powder particles in synthetic biological media

International Nuclear Information System (INIS)

Midander, Klara; Wallinder, Inger Odnevall; Leygraf, Christofer

2007-01-01

The aim of this paper is to provide quantitative data on copper release from powder particles of different copper materials, including artificial copper patina, Cu 2 O and metallic Cu, when exposed to different synthetic biological media to simulate an inhalation scenario and/or skin contact. Generated data may contribute in risk assessment of potential health effects following exposure to and handling of various copper materials. All tests were performed in vitro to determine total copper concentrations, release rates of total copper, and to elucidate its time-dependence. The copper release process was interpreted in terms of specific surface area, surface morphology-, and composition. All powder materials show a time-dependent release process with total copper release rates less than 3 μg/cm 2 per hour at steady state conditions, for all media investigated. The importance of using relevant test media when simulating different interstitial lung conditions and difficulties encountered when comparing powder particles of essentially different properties are thoroughly discussed. - Copper release rates from particles are essential to assess potential health aspects

Sensing response of copper phthalocyanine salt dispersed glass with organic vapours

Energy Technology Data Exchange (ETDEWEB)

Ridhi, R.; Sachdeva, Sheenam; Saini, G. S. S.; Tripathi, S. K., E-mail: surya@pu.ac.in [Department of Physics, Center of Advanced Study in Physics, Panjab University, Chandigarh-160 014 (INDIA) Fax: +91-172-2783336; Tel.:+91-172-2544362 (India)

2016-05-06

Copper Phthalocyanine and other Metal Phthalocyanines are very flexible and tuned easily to modify their structural, spectroscopic, optical and electrical properties by either functionalizing them with various substituent groups or by replacing or adding a ligand to the central metal atom in the phthalocyanine ring and accordingly can be made sensitive and selective to various organic species or gaseous vapours. In the present work, we have dispersed Copper Phthalocyanine Salt (CuPcS) in sol-gel glass form using chemical route sol-gel method and studied its sensing mechanism with organic vapours like methanol and benzene and found that current increases onto their exposure with vapours. A variation in the activation energies was also observed with exposure of vapours.

Prolonged inorganic arsenite exposure suppresses insulin-stimulated AKT S473 phosphorylation and glucose uptake in 3T3-L1 adipocytes: Involvement of the adaptive antioxidant response

International Nuclear Information System (INIS)

Xue, Peng; Hou, Yongyong; Zhang, Qiang; Woods, Courtney G.; Yarborough, Kathy; Liu, Huiyu; Sun, Guifan; Andersen, Melvin E.; Pi, Jingbo

2011-01-01

Highlights: → In 3T3-L1 adipocytes iAs 3+ decreases insulin-stimulated glucose uptake. → iAs 3+ attenuates insulin-induced phosphorylation of AKT S473. → iAs 3+ activates the cellular adaptive oxidative stress response. → iAs 3+ impairs insulin-stimulated ROS signaling. → iAs 3+ decreases expression of adipogenic genes and GLUT4. -- Abstract: There is growing evidence that chronic exposure of humans to inorganic arsenic, a potent environmental oxidative stressor, is associated with the incidence of type 2 diabetes (T2D). One critical feature of T2D is insulin resistance in peripheral tissues, especially in mature adipocytes, the hallmark of which is decreased insulin-stimulated glucose uptake (ISGU). Despite the deleterious effects of reactive oxygen species (ROS), they have been recognized as a second messenger serving an intracellular signaling role for insulin action. Nuclear factor erythroid 2-related factor 2 (NRF2) is a central transcription factor regulating cellular adaptive response to oxidative stress. This study proposes that in response to arsenic exposure, the NRF2-mediated adaptive induction of endogenous antioxidant enzymes blunts insulin-stimulated ROS signaling and thus impairs ISGU. Exposure of differentiated 3T3-L1 cells to low-level (up to 2 μM) inorganic arsenite (iAs 3+ ) led to decreased ISGU in a dose- and time-dependent manner. Concomitant to the impairment of ISGU, iAs 3+ exposure significantly attenuated insulin-stimulated intracellular ROS accumulation and AKT S473 phosphorylation, which could be attributed to the activation of NRF2 and induction of a battery of endogenous antioxidant enzymes. In addition, prolonged iAs 3+ exposure of 3T3-L1 adipocytes resulted in significant induction of inflammatory response genes and decreased expression of adipogenic genes and glucose transporter type 4 (GLUT4), suggesting chronic inflammation and reduction in GLUT4 expression may also be involved in arsenic-induced insulin resistance in

Prolonged inorganic arsenite exposure suppresses insulin-stimulated AKT S473 phosphorylation and glucose uptake in 3T3-L1 adipocytes: Involvement of the adaptive antioxidant response

Energy Technology Data Exchange (ETDEWEB)

Xue, Peng [The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States); School of Public Health, China Medical University, Shenyang 110001 (China); Hou, Yongyong; Zhang, Qiang; Woods, Courtney G.; Yarborough, Kathy; Liu, Huiyu [The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States); Sun, Guifan [School of Public Health, China Medical University, Shenyang 110001 (China); Andersen, Melvin E. [The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States); Pi, Jingbo, E-mail: jpi@thehamner.org [The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States)

2011-04-08

Highlights: {yields} In 3T3-L1 adipocytes iAs{sup 3+} decreases insulin-stimulated glucose uptake. {yields} iAs{sup 3+} attenuates insulin-induced phosphorylation of AKT S473. {yields} iAs{sup 3+} activates the cellular adaptive oxidative stress response. {yields} iAs{sup 3+} impairs insulin-stimulated ROS signaling. {yields} iAs{sup 3+} decreases expression of adipogenic genes and GLUT4. -- Abstract: There is growing evidence that chronic exposure of humans to inorganic arsenic, a potent environmental oxidative stressor, is associated with the incidence of type 2 diabetes (T2D). One critical feature of T2D is insulin resistance in peripheral tissues, especially in mature adipocytes, the hallmark of which is decreased insulin-stimulated glucose uptake (ISGU). Despite the deleterious effects of reactive oxygen species (ROS), they have been recognized as a second messenger serving an intracellular signaling role for insulin action. Nuclear factor erythroid 2-related factor 2 (NRF2) is a central transcription factor regulating cellular adaptive response to oxidative stress. This study proposes that in response to arsenic exposure, the NRF2-mediated adaptive induction of endogenous antioxidant enzymes blunts insulin-stimulated ROS signaling and thus impairs ISGU. Exposure of differentiated 3T3-L1 cells to low-level (up to 2 {mu}M) inorganic arsenite (iAs{sup 3+}) led to decreased ISGU in a dose- and time-dependent manner. Concomitant to the impairment of ISGU, iAs{sup 3+} exposure significantly attenuated insulin-stimulated intracellular ROS accumulation and AKT S473 phosphorylation, which could be attributed to the activation of NRF2 and induction of a battery of endogenous antioxidant enzymes. In addition, prolonged iAs{sup 3+} exposure of 3T3-L1 adipocytes resulted in significant induction of inflammatory response genes and decreased expression of adipogenic genes and glucose transporter type 4 (GLUT4), suggesting chronic inflammation and reduction in GLUT4

Effect of copper on the characterization of proteins in the Spiny lobster, Panulirus homarus homarus (Linnaeus,1758

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Maharajan Athisuyambulingam

2014-07-01

Full Text Available Copper is most toxic metal in marine organisms. Characterization of protein occurring in the metabolically active tissues of muscle (MU, hepatopancreas (HP and gills (GL of the spiny lobster, Panulirus homarus homarus on exposure to two sub-lethal doses (9.55 and 19.1 µg/l of copper were studied for 28 days of exposure (DoE. The electrophoretic pattern of muscle, hepatopancreas and gill proteins revealed 12, 8 and 8 slow moving bands (control. The number of bands decreased to 8 and 7, 6 and 5, 6 and 4 after 7 days of exposure to 9.55 µg/l and 19.1 µg/l concentrations of copper, respectively. After 28 days, the protein bands decreased to 7 and 6, 5 and 4, 4 and 4 at 9.55 µg/l and 19.1 µg/l concentrations of copper, respectively. Present study to indicate that to avoid the Cupro-Nickel coil in lobster holding centers in chiller plants used for cooling of water was found to be responsible for the mortality of lobsters during live transportation.

Changes in negative cognitions mediate PTSD symptom reductions during client-centered therapy and prolonged exposure for adolescents.

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McLean, Carmen P; Yeh, Rebecca; Rosenfield, David; Foa, Edna B

2015-05-01

To assess whether changes in negative trauma-related cognitions play an important role in reducing symptoms of posttraumatic stress disorder (PTSD) and depression during prolonged exposure therapy for adolescents (PE-A). Secondary analysis of data from a randomized controlled trial comparing PE-A with client-centered therapy (CCT) for PTSD. Participants were 61 adolescent female sexual assault survivors ages 13-18 who received 8-14 weekly sessions of PE-A or CCT at a community rape crisis center. PTSD severity was assessed at baseline, mid-treatment, post-treatment, and 3-months post-treatment. Participants also completed self-report measures of negative posttraumatic cognitions and depressive symptoms at the same assessment points. Cross lag panel mediation analyses showed that change in negative trauma-related cognitions mediated change in PTSD symptoms and depressive symptoms whereas change in PTSD and depressive symptoms did not mediate change in negative cognitions. Our findings support EPT and suggest that change in negative trauma-related cognitions is a mechanism of both PE-A and CCT. Copyright © 2015 Elsevier Ltd. All rights reserved.

A PROBABILISTIC EXPOSURE ASSESSMENT FOR CHILDREN WHO CONTACT CCA-TREATED PLAYSETS AND DECKS USING THE STOCHASTIC HUMAN EXPOSURE AND DOSE SIMULATION (SHEDS) MODEL FOR THE WOOD PRESERVATIVE EXPOSURE SCENARIO

Science.gov (United States)

The U.S. Environmental Protection Agency has conducted a probabilistic exposure and dose assessment on the arsenic (As) and chromium (Cr) components of Chromated Copper Arsenate (CCA) using the Stochastic Human Exposure and Dose Simulation model for wood preservatives (SHEDS-Wood...

Copper and copper-nickel alloys as zebra mussel antifoulants

Energy Technology Data Exchange (ETDEWEB)

Dormon, J.M.; Cottrell, C.M.; Allen, D.G.; Ackerman, J.D.; Spelt, J.K. [Univ. of Toronto, Ontario (Canada)

1996-04-01

Copper has been used in the marine environment for decades as cladding on ships and pipes to prevent biofouling by marine mussels (Mytilus edulis L.). This motivated the present investigation into the possibility of using copper to prevent biofouling in freshwater by both zebra mussels and quagga mussels (Dreissena polymorpha and D. bugensis collectively referred to as zebra mussels). Copper and copper alloy sheet proved to be highly effective in preventing biofouling by zebra mussels over a three-year period. Further studies were conducted with copper and copper-nickel mesh (lattice of expanded metal) and screen (woven wire with a smaller hole size), which reduced the amount of copper used. Copper screen was also found to be strongly biofouling-resistant with respect to zebra mussels, while copper mesh reduced zebra mussel biofouling in comparison to controls, but did not prevent it entirely. Preliminary investigations into the mechanism of copper antifouling, using galvanic couples, indicated that the release of copper ions from the surface of the exposed metal into the surrounding water is directly or indirectly responsible for the biofouling resistance of copper.

Axenic aerobic biofilms inhibit corrosion of copper and aluminum.

Science.gov (United States)

Jayaraman, A; Ornek, D; Duarte, D A; Lee, C C; Mansfeld, F B; Wood, T K

1999-11-01

The corrosion behavior of unalloyed copper and aluminum alloy 2024 in modified Baar's medium has been studied with continuous reactors using electrochemical impedance spectroscopy. An axenic aerobic biofilm of either Pseudomonas fragi K or Bacillus brevis 18 was able to lessen corrosion as evidenced by a consistent 20-fold increase in the low-frequency impedance value of copper as well as by a consistent four- to seven-fold increase in the polarization resistance of aluminum 2024 after six days exposure compared to sterile controls. This is the first report of axenic aerobic biofilms inhibiting generalized corrosion of copper and aluminum. Addition of the representative sulfate-reducing bacterium (SRB) Desulfovibrio vulgaris (to simulate consortia corrosion behavior) to either the P. fragi K or B. brevis 18 protective biofilm on copper increased the corrosion to that of the sterile control unless antibiotic (ampicillin) was added to inhibit the growth of SRB in the biofilm.

Effects of Copper Oxide Nanoparticles on Antioxidant Enzyme Activities and on Tissue Accumulation of Oreochromis niloticus.

Science.gov (United States)

Tunçsoy, Mustafa; Duran, Servet; Ay, Özcan; Cicik, Bedii; Erdem, Cahit

2017-09-01

Accumulation of copper oxide nanoparticles (CuO NPs) in gill, liver and muscle tissues of Oreochromis niloticus and its effects on superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities in gill and liver tissues were studied after exposing the fish to 20 µg/L Cu over 15 days. Copper levels and enzyme activities in tissues were determined using spectrophotometric (ICP-AES and UV) techniques respectively. No mortality was observed during the experiments. Copper levels increased in gill and liver tissues of O. niloticus compared to control when exposed to CuO NPs whereas exposure to metal had no effect on muscle level at the end of the exposure period. Highest accumulation of copper was observed in liver while no accumulation was detected in muscle tissue. SOD, CAT activities decreased and GPx activity increased in gill and liver tissues when exposed to CuO NPs.

Copper induces expression and methylation changes of early development genes in Crassostrea gigas embryos.

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Sussarellu, Rossana; Lebreton, Morgane; Rouxel, Julien; Akcha, Farida; Rivière, Guillaume

2018-03-01

Copper contamination is widespread along coastal areas and exerts adverse effects on marine organisms such as mollusks. In the Pacific oyster, copper induces severe developmental abnormalities during early life stages; however, the underlying molecular mechanisms are largely unknown. This study aims to better understand whether the embryotoxic effects of copper in Crassostrea gigas could be mediated by alterations in gene expression, and the putative role of DNA methylation, which is known to contribute to gene regulation in early embryo development. For that purpose, oyster embryos were exposed to 4 nominal copper concentrations (0.1, 1, 10 and 20 μg L -1 Cu 2+ ) during early development assays. Embryotoxicity was monitored through the oyster embryo-larval bioassay at the D-larva stage 24 h post fertilization (hpf) and genotoxicity at gastrulation 7 hpf. In parallel, the relative expression of 15 genes encoding putative homeotic, biomineralization and DNA methylation proteins was measured at three developmental stages (3 hpf morula stage, 7 hpf gastrula stage, 24 hpf D-larvae stage) using RT-qPCR. Global DNA content in methylcytosine and hydroxymethylcytosine were measured by HPLC and gene-specific DNA methylation levels were monitored using MeDIP-qPCR. A significant increase in larval abnormalities was observed from copper concentrations of 10 μg L -1 , while significant genotoxic effects were detected at 1 μg L -1 and above. All the selected genes presented a stage-dependent expression pattern, which was impaired for some homeobox and DNA methylation genes (Notochord, HOXA1, HOX2, Lox5, DNMT3b and CXXC-1) after copper exposure. While global DNA methylation (5-methylcytosine) at gastrula stage didn't show significant changes between experimental conditions, 5-hydroxymethylcytosine, its degradation product, decreased upon copper treatment. The DNA methylation of exons and the transcript levels were correlated in control samples for HOXA1 but such

Copper and Copper Proteins in Parkinson’s Disease

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Sergio Montes

2014-01-01

Full Text Available Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson’s disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson’s disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased protein-bound copper in brain may enhance iron accumulation and the associated oxidative stress. The function of other copper-binding proteins such as Cu/Zn-SOD and metallothioneins is also beneficial to prevent neurodegeneration. Copper may regulate neurotransmission since it is released after neuronal stimulus and the metal is able to modulate the function of NMDA and GABA A receptors. Some of the proteins involved in copper transport are the transporters CTR1, ATP7A, and ATP7B and the chaperone ATOX1. There is limited information about the role of those biomolecules in the pathophysiology of Parkinson’s disease; for instance, it is known that CTR1 is decreased in substantia nigra pars compacta in Parkinson’s disease and that a mutation in ATP7B could be associated with Parkinson’s disease. Regarding copper-related therapies, copper supplementation can represent a plausible alternative, while copper chelation may even aggravate the pathology.

Assessment of the environmental effects associated with wooden bridges preserved with creosote, pentachlorophenol, or chromated copper arsenate

Science.gov (United States)

Kenneth M. Brooks

Timber bridges provide an economical alternative to concrete and steel structures, particularly in rural areas with light to moderate vehicle traffic. Wooden components of these bridges are treated with chromated copper arsenate type C (CCA), pentachlorophenol, or creosote to prolong the life of the structure from a few years to many decades. This results in reduced...

Pre-treatment Predictors of Dropout from Prolonged Exposure Therapy in Patients with Chronic Posttraumatic Stress Disorder and Comorbid Substance Use Disorders

Science.gov (United States)

Belleau, Emily L.; Chin, Eu Gene; Wanklyn, Sonya G.; Zambrano-Vazquez, Laura; Schumacher, Julie A.; Coffey, Scott F.

2017-01-01

Posttraumatic stress disorder (PTSD) and substance use disorders (SUDs) are commonly co-occurring disorders associated with more adverse consequences than PTSD alone. Prolonged exposure therapy (PE) is one of the most efficacious treatments for PTSD. However, among individuals with PTSD-SUD, 35–62% of individuals drop out of trauma-focused exposure treatments. Thus, it is important to identify predictors of PTSD treatment dropout among substance abusers with PTSD in order to gain information about adapting treatment strategies to enhance retention and outcomes. The current study explored pre-treatment predictors of early termination from PE treatment in a sample of 85 individuals receiving concurrent treatment for PTSD and a SUD in a residential treatment facility as part of a randomized controlled trial. The results indicated that less education and more anxiety sensitivity uniquely predicted PE treatment dropout. Demographic variables, PTSD severity, SUD severity, mental health comorbidities, and emotion regulation difficulties did not predict treatment dropout. These results suggest that adding pre-treatment interventions that address anxiety sensitivity, and promote social adjustment and cognitive flexibility, could possibly improve PE retention rates in clients with high anxiety or low education. PMID:28147254

Lung volumes identify an at-risk group in persons with prolonged secondhand tobacco smoke exposure but without overt airflow obstruction.

Science.gov (United States)

Arjomandi, Mehrdad; Zeng, Siyang; Geerts, Jeroen; Stiner, Rachel K; Bos, Bruce; van Koeverden, Ian; Keene, Jason; Elicker, Brett; Blanc, Paul D; Gold, Warren M

2018-01-01

Exposure to secondhand smoke (SHS) is associated with occult obstructive lung disease as evident by abnormal airflow indices representing small airway disease despite having preserved spirometry (normal forced expiratory volume in 1 s-to-forced vital capacity ratio, FEV 1 /FVC). The significance of lung volumes that reflect air trapping in the presence of preserved spirometry is unclear. To investigate whether lung volumes representing air trapping could determine susceptibility to respiratory morbidity in people with SHS exposure but without spirometric chronic obstructive pulmonary disease, we examined a cohort of 256 subjects with prolonged occupational SHS exposure and preserved spirometry. We elicited symptom prevalence by structured questionnaires, examined functional capacity (maximum oxygen uptake, VO 2max ) by exercise testing, and estimated associations of those outcomes with air trapping (plethysmography-measured residual volume-to-total lung capacity ratio, RV/TLC), and progressive air trapping with exertion (increase in fraction of tidal breathing that is flow limited on expiration during exercise (per cent of expiratory flow limitation, %EFL)). RV/TLC was within the predicted normal limits, but was highly variable spanning 22%±13% and 16%±8% across the increments of FEV 1 /FVC and FEV 1 , respectively. Respiratory complaints were prevalent (50.4%) with the most common symptom being ≥2 episodes of cough per year (44.5%). Higher RV/TLC was associated with higher OR of reporting respiratory symptoms (n=256; r 2 =0.03; p=0.011) and lower VO 2max (n=179; r 2 =0.47; p=0.013), and %EFL was negatively associated with VO 2max (n=32; r 2 =0.40; p=0.017). In those at risk for obstruction due to SHS exposure but with preserved spirometry, higher RV/TLC identifies a subgroup with increased respiratory symptoms and lower exercise capacity.

The Effect of Copper on the Color of Shrimps: Redder Is Not Always Healthier

Science.gov (United States)

Martínez, Ana; Romero, Yanet; Castillo, Tania; Mascaró, Maite; López-Rull, Isabel; Simões, Nuno; Arcega-Cabrera, Flor; Gaxiola, Gabriela; Barbosa, Andrés

2014-01-01

The objective of this research is to test the effects of copper on the color of pacific white shrimp (Litopenaeus vannamei) in vivo. Forty-eight shrimps (L. vannamei) were exposed to a low concentration of copper (1 mg/L; experimental treatment) and forty-eight shrimps were used as controls (no copper added to the water). As a result of this experiment, it was found that shrimps with more copper are significantly redder than those designated as controls (hue (500–700 nm): P = 0.0015; red chroma (625–700 nm): P<0.0001). These results indicate that redder color may result from exposure to copper and challenge the commonly held view that highly pigmented shrimps are healthier than pale shrimps. PMID:25229639

Copper carrier protein in copper toxic sheep liver

Energy Technology Data Exchange (ETDEWEB)

Harris, A L; Dean, P D.G.

1973-01-01

The livers of copper-toxic sheep have been analyzed by gel electrophoresis followed by staining the gels for copper with diethyldithiocarbamate and for protein with amido schwartz. These gels were compared with similar gels obtained from the livers of normal and copper-deficient animals. The copper-toxic livers contained an extra protein band which possessed relatively weakly bound copper. Possible origins of this protein are discussed. 8 references, 1 figure, 2 tables.

Prenatal nicotinic exposure upregulates pulmonary C-fiber NK1R expression to prolong pulmonary C-fiber-mediated apneic response

International Nuclear Information System (INIS)

Zhao, Lei; Zhuang, Jianguo; Zang, Na; Lin, Yong; Lee, Lu-Yuan; Xu, Fadi

2016-01-01

Prenatal nicotinic exposure (PNE) prolongs bronchopulmonary C-fiber (PCF)-mediated apneic response to intra-atrial bolus injection of capsaicin in rat pups. The relevant mechanisms remain unclear. Pulmonary substance P and adenosine and their receptors (neurokinin-A receptor, NK1R and ADA 1 receptor, ADA 1 R) and transient receptor potential cation channel subfamily V member 1 (TRPV1) expressed on PCFs are critical for PCF sensitization and/or activation. Here, we compared substance P and adenosine in BALF and NK1R, ADA 1 R, and TRPV1 expression in the nodose/jugular (N/J) ganglia (vagal pulmonary C-neurons retrogradely labeled) between Ctrl and PNE pups. We found that PNE failed to change BALF substance P and adenosine content, but significantly upregulated both mRNA and protein TRPV1 and NK1R in the N/J ganglia and only NK1R mRNA in pulmonary C-neurons. To define the role of NK1R in the PNE-induced PCF sensitization, the apneic response to capsaicin (i.v.) without or with pretreatment of SR140333 (a peripheral and selective NK1R antagonist) was compared and the prolonged apnea by PNE significantly shortened by SR140333. To clarify if the PNE-evoked responses depended on action of nicotinic acetylcholine receptors (nAChRs), particularly α7nAChR, mecamylamine or methyllycaconitine (a general nAChR or a selective α7nAChR antagonist) was administrated via another mini-pump over the PNE period. Mecamylamine or methyllycaconitine eliminated the PNE-evoked mRNA and protein responses. Our data suggest that PNE is able to elevate PCF NK1R expression via activation of nAChRs, especially α7nAChR, which likely contributes to sensitize PCFs and prolong the PCF-mediated apneic response to capsaicin. - Highlights: • PNE upregulated NK1R and TRPV1 gene and protein expression in the N/J ganglia. • PNE only elevated NK1R mRNA in vagal pulmonary C-neurons. • Blockage of peripheral NK1R reduced the PNE-induced PCF sensitization. • PNE induced gene and protein changes in

Accelerated Degradation Test and Predictive Failure Analysis of B10 Copper-Nickel Alloy under Marine Environmental Conditions

Science.gov (United States)

Sun, Bo; Ye, Tianyuan; Feng, Qiang; Yao, Jinghua; Wei, Mumeng

2015-01-01

This paper studies the corrosion behavior of B10 copper-nickel alloy in marine environment. Accelerated degradation test under marine environmental conditions was designed and performed based on the accelerated testing principle and the corrosion degradation mechanism. With the prolongation of marine corrosion time, the thickness of Cu2O film increased gradually. Its corrosion product was Cu2(OH)3Cl, which increased in quantity over time. Cl− was the major factor responsible for the marine corrosion of copper and copper alloy. Through the nonlinear fitting of corrosion rate and corrosion quantity (corrosion weight loss), degradation data of different corrosion cycles, the quantitative effects of two major factors, i.e., dissolved oxygen (DO) and corrosion medium temperature, on corrosion behavior of copper alloy were analyzed. The corrosion failure prediction models under different ambient conditions were built. One-day corrosion weight loss under oxygenated stirring conditions was equivalent to 1.31-day weight loss under stationary conditions, and the corrosion rate under oxygenated conditions was 1.31 times higher than that under stationary conditions. In addition, corrosion medium temperature had a significant effect on the corrosion of B10 copper sheet. PMID:28793549

Accelerated Degradation Test and Predictive Failure Analysis of B10 Copper-Nickel Alloy under Marine Environmental Conditions.

Science.gov (United States)

Sun, Bo; Ye, Tianyuan; Feng, Qiang; Yao, Jinghua; Wei, Mumeng

2015-09-10

This paper studies the corrosion behavior of B10 copper-nickel alloy in marine environment. Accelerated degradation test under marine environmental conditions was designed and performed based on the accelerated testing principle and the corrosion degradation mechanism. With the prolongation of marine corrosion time, the thickness of Cu₂O film increased gradually. Its corrosion product was Cu₂(OH)₃Cl, which increased in quantity over time. Cl - was the major factor responsible for the marine corrosion of copper and copper alloy. Through the nonlinear fitting of corrosion rate and corrosion quantity (corrosion weight loss), degradation data of different corrosion cycles, the quantitative effects of two major factors, i.e. , dissolved oxygen (DO) and corrosion medium temperature, on corrosion behavior of copper alloy were analyzed. The corrosion failure prediction models under different ambient conditions were built. One-day corrosion weight loss under oxygenated stirring conditions was equivalent to 1.31-day weight loss under stationary conditions, and the corrosion rate under oxygenated conditions was 1.31 times higher than that under stationary conditions. In addition, corrosion medium temperature had a significant effect on the corrosion of B10 copper sheet.

Accelerated Degradation Test and Predictive Failure Analysis of B10 Copper-Nickel Alloy under Marine Environmental Conditions

Directory of Open Access Journals (Sweden)

Bo Sun

2015-09-01

Full Text Available This paper studies the corrosion behavior of B10 copper-nickel alloy in marine environment. Accelerated degradation test under marine environmental conditions was designed and performed based on the accelerated testing principle and the corrosion degradation mechanism. With the prolongation of marine corrosion time, the thickness of Cu2O film increased gradually. Its corrosion product was Cu2(OH3Cl, which increased in quantity over time. Cl− was the major factor responsible for the marine corrosion of copper and copper alloy. Through the nonlinear fitting of corrosion rate and corrosion quantity (corrosion weight loss, degradation data of different corrosion cycles, the quantitative effects of two major factors, i.e., dissolved oxygen (DO and corrosion medium temperature, on corrosion behavior of copper alloy were analyzed. The corrosion failure prediction models under different ambient conditions were built. One-day corrosion weight loss under oxygenated stirring conditions was equivalent to 1.31-day weight loss under stationary conditions, and the corrosion rate under oxygenated conditions was 1.31 times higher than that under stationary conditions. In addition, corrosion medium temperature had a significant effect on the corrosion of B10 copper sheet.

Auger electron and X-ray photoelectron spectroscopic study of the biocorrosion of copper by alginic acid polysaccharide

Science.gov (United States)

Jolley, John G.; Geesey, Gill G.; Hankins, Michael R.; Wright, Randy B.; Wichlacz, Paul L.

1989-08-01

Thin films (3.4 nm) of copper on germanium substrates were exposed to 2% alginic acid polysaccharide aqueous solution. Pre- and post-exposure characterization were done by Auger electron spectroscopy and X-ray photoelectron spectroscopy. Ancillary graphite furnace atomic absorption spectroscopy was used to monitor the removal process of the copper thin film from the germanium substrate. Results indicate that some of the copper was oxidized by the alginic acid solution. Some of the copper was removed from the Cu/Ge interface and incorporated into the polymer matrix. Thus, biocorrosion of copper was exhibited by the alginic acid polysaccharide.

Proteomic and physiological responses of Kineococcus radiotolerans to copper.

Directory of Open Access Journals (Sweden)

Christopher E Bagwell

Full Text Available Copper is a highly reactive, toxic metal; consequently, transport of this metal within the cell is tightly regulated. Intriguingly, the actinobacterium Kineococcus radiotolerans has been shown to not only accumulate soluble copper to high levels within the cytoplasm, but the phenotype also correlated with enhanced cell growth during chronic exposure to ionizing radiation. This study offers a first glimpse into the physiological and proteomic responses of K. radiotolerans to copper at increasing concentration and distinct growth phases. Aerobic growth rates and biomass yields were similar over a range of Cu(II concentrations (0-1.5 mM in complex medium. Copper uptake coincided with active cell growth and intracellular accumulation was positively correlated with Cu(II concentration in the growth medium (R(2=0.7. Approximately 40% of protein coding ORFs on the K. radiotolerans genome were differentially expressed in response to the copper treatments imposed. Copper accumulation coincided with increased abundance of proteins involved in oxidative stress and defense, DNA stabilization and repair, and protein turnover. Interestingly, the specific activity of superoxide dismutase was repressed by low to moderate concentrations of copper during exponential growth, and activity was unresponsive to perturbation with paraquot. The biochemical response pathways invoked by sub-lethal copper concentrations are exceptionally complex; though integral cellular functions are preserved, in part, through the coordination of defense enzymes, chaperones, antioxidants and protective osmolytes that likely help maintain cellular redox. This study extends our understanding of the ecology and physiology of this unique actinobacterium that could potentially inspire new biotechnologies in metal recovery and sequestration, and environmental restoration.

Proteomic and physiological responses of Kineococcus radiotolerans to copper.

Science.gov (United States)

Bagwell, Christopher E; Hixson, Kim K; Milliken, Charles E; Lopez-Ferrer, Daniel; Weitz, Karl K

2010-08-26

Copper is a highly reactive, toxic metal; consequently, transport of this metal within the cell is tightly regulated. Intriguingly, the actinobacterium Kineococcus radiotolerans has been shown to not only accumulate soluble copper to high levels within the cytoplasm, but the phenotype also correlated with enhanced cell growth during chronic exposure to ionizing radiation. This study offers a first glimpse into the physiological and proteomic responses of K. radiotolerans to copper at increasing concentration and distinct growth phases. Aerobic growth rates and biomass yields were similar over a range of Cu(II) concentrations (0-1.5 mM) in complex medium. Copper uptake coincided with active cell growth and intracellular accumulation was positively correlated with Cu(II) concentration in the growth medium (R(2)=0.7). Approximately 40% of protein coding ORFs on the K. radiotolerans genome were differentially expressed in response to the copper treatments imposed. Copper accumulation coincided with increased abundance of proteins involved in oxidative stress and defense, DNA stabilization and repair, and protein turnover. Interestingly, the specific activity of superoxide dismutase was repressed by low to moderate concentrations of copper during exponential growth, and activity was unresponsive to perturbation with paraquot. The biochemical response pathways invoked by sub-lethal copper concentrations are exceptionally complex; though integral cellular functions are preserved, in part, through the coordination of defense enzymes, chaperones, antioxidants and protective osmolytes that likely help maintain cellular redox. This study extends our understanding of the ecology and physiology of this unique actinobacterium that could potentially inspire new biotechnologies in metal recovery and sequestration, and environmental restoration.

Metal X-ray microanalysis in the olfactory system of rainbow trout exposed to low level of copper

International Nuclear Information System (INIS)

Julliard, A.K.; Astic, L.; Saucier, D.

1995-01-01

It has recently been shown that a chronic copper exposure induces specific degeneration of olfactory receptor cells in rainbow trout; however, the exact mechanism of action of the metal is not yet known. Using X-ray microanalysis in transmission electron microscopy, we have studied the distribution of metal in the olfactory system of fish exposed for 15,30 and 60 days to 20 μg/l of copper. This was done in order to determine if it was accumulated in receptor cells and transported into the central nervous system via the olfactory nerve. No copper accumulation was detected either in the olfactory epithelium, in the olfactory nerve or in the olfactory bulb. The heavy metal was exclusively found within melanosomes of melanophores located in the lamina propria. After 60 days of exposure, the copper content in melanosomes was about two-fold higher than that in controls. As far as some morphological recovery took place in the olfactory organ during the metal exposure, which lets us suppose that some detoxication mechanism occurs, it could be suggested that metanophores might be somehow involved in such a mechanism. (authors). 57 refs., 15 figs

Temperature modulates phototrophic periphyton response to chronic copper exposure

International Nuclear Information System (INIS)

Lambert, Anne Sophie; Dabrin, Aymeric; Morin, Soizic; Gahou, Josiane; Foulquier, Arnaud; Coquery, Marina; Pesce, Stéphane

2016-01-01

Streams located in vineyard areas are highly prone to metal pollution. In a context of global change, aquatic systems are generally subjected to multi-stress conditions due to multiple chemical and/or physical pressures. Among various environmental factors that modulate the ecological effects of toxicants, special attention should be paid to climate change, which is driving an increase in extreme climate events such as sharp temperature rises. In lotic ecosystems, periphyton ensures key ecological functions such as primary production and nutrient cycling. However, although the effects of metals on microbial communities are relatively well known, there is scant data on possible interactions between temperature increase and metal pollution. Here we led a study to evaluate the influence of temperature on the response of phototrophic periphyton to copper (Cu) exposure. Winter communities, collected in a 8 °C river water, were subjected for six weeks to four thermal conditions in microcosms in presence or not of Cu (nominal concentration of 15 μg L"−"1). At the initial river temperature (8 °C), our results confirmed the chronic impact of Cu on periphyton, both in terms of structure (biomass, distribution of algal groups, diatomic composition) and function (photosynthetic efficiency). At higher temperatures (13, 18 and 23 °C), Cu effects were modulated. Indeed, temperature increase reduced Cu effects on algal biomass, algal class proportions, diatom assemblage composition and photosynthetic efficiency. This reduction of Cu effects on periphyton may be related to lower bioaccumulation of Cu and/or to selection of more Cu-tolerant species at higher temperatures. - Highlights: • At in situ temperature, Cu impacted structure and activity of phototrophic biofilms. • Cu effects were reduced with increasing temperature (from +5 °C to +15 °C). • The decrease in Cu effects may be related to lower Cu bioaccumulation in biofilms. • Changes in diatom

Effect of cold work on creep properties of oxygen-free copper

International Nuclear Information System (INIS)

Martinsson, Aasa; Andersson-Oestling, Henrik C.M.

2009-03-01

Spent nuclear fuel is in Sweden planned to be disposed by encapsulating in waste packages consisting of a cast iron insert surrounded by a copper canister. The cast iron is load bearing and the copper canister gives corrosion protection. The waste package is heavy. Throughout the manufacturing process from the extrusion/pierce-and-draw manufacturing to the final placement in the repository, the copper is subjected to handling which could introduce cold work in the material. It is well known that the creep properties of engineering materials at higher temperatures are affected by cold working. The study includes creep testing of four series of cold worked, oxygen-free, phosphorus doped copper (Cu-OFP) at 75 deg C. The results are compared to reference series for as series of copper cold worked in tension (12 and 24 %) and two series cold worked in compression (12 % parallel to creep load axis and 15 % perpendicular to creep load axis) were tested. The results show that pre-straining in tension of copper leads to prolonged creep life at 75 deg C. The creep rate and ductility are reduced. The influence on the creep properties increases with the amount of cold work. Cold work in compression applied along the creep load axis has no effect on the creep life or the creep rate. Nonetheless the ductility is still impaired. However, cold work in compression applied perpendicular to the creep load direction has a positive effect on the creep life. Cold work in both tension and compression results in a pronounced reduction of the initial creep strain, which is the strain obtained from the beginning of the loading until full creep load is achieved. Yet the area reduction is unaffected by the degree of cold work

Cellular membrane accommodation of copper-induced oxidative conditions in the coral Seriatopora caliendrum

Energy Technology Data Exchange (ETDEWEB)

Tang, Chuan-Ho, E-mail: chtang@nmmba.gov.tw [Institute of Marine Biodiversity and Evolutionary Biology, National Dong Hwa University, Pingtung, Taiwan, ROC (China); National Museum of Marine Biology and Aquarium, Pingtung, Taiwan, ROC (China); Lin, Ching-Yu [Institute of Environmental Health, National Taiwan University, Taipei City, Taiwan, ROC (China); Lee, Shu-Hui [Center of General Education, National Kaohsiung Marine University, Kaohsiung, Taiwan, ROC (China); Wang, Wei-Hsien [National Museum of Marine Biology and Aquarium, Pingtung, Taiwan, ROC (China); Department of Marine Biotechnology and Resources and Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan, ROC (China)

2014-03-01

Highlights: • Coral cells alter membrane lipid to accommodate copper-induce oxidative conditions • Coral membrane repair occur due to lipid alterations • Zooxanthellae release results from membrane repair by symbiosome fusion • Copper-induced lipid alterations perturb membrane-related functions in coral cells • Copper chronic effect on coral fitness are related to long-term membrane perturbation - Abstract: Oxidative stress has been associated with copper-induced toxicity in scleractinian corals. To gain insight into the accommodation of the cellular membrane to oxidative conditions, a pocilloporid coral, Seriatopora caliendrum, was exposed to copper at distinct, environmentally relevant dose for various lengths of time. Glycerophosphocholine profiling of the response of the coral to copper exposure was characterized using a validated method. The results indicate that coral lipid metabolism is programmed to induce membrane alterations in response to the cellular deterioration that occurs during the copper exposure period. Decreasing lyso-phosphatidylcholines and exchanging polyunsaturated phosphatidylcholines for polyunsaturated plasmanylcholines were the initial actions taken to prevent membrane permeabilization. To relax/resist the resulting membrane strain caused by cell/organelle swelling, the coral cells inversely exchanged polyunsaturated plasmanylcholines for polyunsaturated phosphatidylcholines and further increased the levels of monounsaturated glycerophosphocholines. At the same time, the levels of saturated phosphatidylcholines were also increased to increase membrane rigidity and protect against oxidative attack. Interestingly, such alterations in lipid metabolism were also required for membrane fusion to repair the deteriorated membranes by repopulating them with proximal lipid reservoirs, similar to symbiosome membranes. Additionally, increasing saturated and monounsaturated plasmanylcholines and inhibiting the suppression of saturated lyso

Cellular membrane accommodation of copper-induced oxidative conditions in the coral Seriatopora caliendrum

International Nuclear Information System (INIS)

Tang, Chuan-Ho; Lin, Ching-Yu; Lee, Shu-Hui; Wang, Wei-Hsien

2014-01-01

Highlights: • Coral cells alter membrane lipid to accommodate copper-induce oxidative conditions • Coral membrane repair occur due to lipid alterations • Zooxanthellae release results from membrane repair by symbiosome fusion • Copper-induced lipid alterations perturb membrane-related functions in coral cells • Copper chronic effect on coral fitness are related to long-term membrane perturbation - Abstract: Oxidative stress has been associated with copper-induced toxicity in scleractinian corals. To gain insight into the accommodation of the cellular membrane to oxidative conditions, a pocilloporid coral, Seriatopora caliendrum, was exposed to copper at distinct, environmentally relevant dose for various lengths of time. Glycerophosphocholine profiling of the response of the coral to copper exposure was characterized using a validated method. The results indicate that coral lipid metabolism is programmed to induce membrane alterations in response to the cellular deterioration that occurs during the copper exposure period. Decreasing lyso-phosphatidylcholines and exchanging polyunsaturated phosphatidylcholines for polyunsaturated plasmanylcholines were the initial actions taken to prevent membrane permeabilization. To relax/resist the resulting membrane strain caused by cell/organelle swelling, the coral cells inversely exchanged polyunsaturated plasmanylcholines for polyunsaturated phosphatidylcholines and further increased the levels of monounsaturated glycerophosphocholines. At the same time, the levels of saturated phosphatidylcholines were also increased to increase membrane rigidity and protect against oxidative attack. Interestingly, such alterations in lipid metabolism were also required for membrane fusion to repair the deteriorated membranes by repopulating them with proximal lipid reservoirs, similar to symbiosome membranes. Additionally, increasing saturated and monounsaturated plasmanylcholines and inhibiting the suppression of saturated lyso

Copper and copper-nickel-alloys - An overview

Energy Technology Data Exchange (ETDEWEB)

Klassert, Anton; Tikana, Ladji [Deutsches Kupferinstitut e.V. Am Bonneshof 5, 40474 Duesseldorf (Germany)

2004-07-01

With the increasing level of industrialization the demand for and the number of copper alloys rose in an uninterrupted way. Today, the copper alloys take an important position amongst metallic materials due to the large variety of their technological properties and applications. Nowadays there exist over 3.000 standardized alloys. Copper takes the third place of all metals with a worldwide consumption of over 15 millions tons per year, following only to steel and aluminum. In a modern industrial society we meet copper in all ranges of the life (electro-technology, building and construction industry, mechanical engineering, automotive, chemistry, offshore, marine engineering, medical applications and others.). Copper is the first metal customized by humanity. Its name is attributed to the island Cyprus, which supplied in the antiquity copper to Greece, Rome and the other Mediterranean countries. The Romans called it 'ore from Cyprus' (aes cyprium), later cuprum. Copper deposited occasionally also dapper and could be processed in the recent stone age simply by hammering. Already in early historical time copper alloys with 20 to 50 percent tin was used for the production of mirrors because of their high reflecting power. Although the elementary nickel is an element discovered only recently from a historical perspective, its application in alloys - without any knowledge of the alloy composition - occurred at least throughout the last 2.000 years. The oldest copper-nickel coin originates from the time around 235 B.C.. Only around 1800 AD nickel was isolated as a metallic element. In particular in the sea and offshore technology copper nickel alloys found a broad field of applications in piping systems and for valves and armatures. The excellent combination of characteristics like corrosion resistance, erosion stability and bio-fouling resistance with excellent mechanical strength are at the basis of this success. An experience of many decades supports the use

Comparison of interaction mechanisms of copper phthalocyanine and nickel phthalocyanine thin films with chemical vapours

Science.gov (United States)

Ridhi, R.; Singh, Sukhdeep; Saini, G. S. S.; Tripathi, S. K.

2018-04-01

The present study deals with comparing interaction mechanisms of copper phthalocyanine and nickel phthalocyanine with versatile chemical vapours: reducing, stable aromatic and oxidizing vapours namely; diethylamine, benzene and bromine. The variation in electrical current of phthalocyanines with exposure of chemical vapours is used as the detection parameter for studying interaction behaviour. Nickel phthalocyanine is found to exhibit anomalous behaviour after exposure of reducing vapour diethylamine due to alteration in its spectroscopic transitions and magnetic states. The observed sensitivities of copper phthalocyanine and nickel phthalcyanine films are different in spite of their similar bond numbers, indicating significant role of central metal atom in interaction mechanism. The variations in electronic transition levels after vapours exposure, studied using UV-Visible spectroscopy confirmed our electrical sensing results. Bromine exposure leads to significant changes in vibrational bands of metal phthalocyanines as compared to other vapours.

Effect of copper on the performance and bacterial communities of activated sludge using Illumina MiSeq platforms.

Science.gov (United States)

Sun, Fu-Lin; Fan, Lei-Lei; Xie, Guang-Jian

2016-08-01

The anaerobic-anoxic-aerobic (A2O) process is a highly efficient sewage treatment method, which uses complex bacterial communities. However, the effect of copper on this process and the bacterial communities involved remains unknown. In this study, a systematic investigation of the effect of persistent exposure of copper in the A2O wastewater treatment system was performed. An A2O device was designed to examine the effect of copper on the removal efficiency and microbial community compositions of activated sludge that was continuously treated with 10, 20, and 40 mg L(-1) copper, respectively. Surprisingly, a decrease in chemical oxygen demand (COD) and ammonia nitrogen (NH4N) removal efficiency was observed, and the toxicity of high copper concentration was significantly greater at 7d than at 1d. Proteobacteria, Bacteroidetes, Acidobacteria, Chlorobi, and Nitrospirae were the dominant bacterial taxa in the A2O system, and significant changes in microbial community were observed during the exposure period. Most of the dominant bacterial groups were easily susceptible to copper toxicity and diversely changed at different copper concentrations. However, not all the bacterial taxa were inhibited by copper treatment. At high copper concentration, many bacterial species were stimulated and their abundance increased. Cluster analysis and principal coordinate analysis (PCoA) based on operational taxonomic units (OTUs) revealed clear differences in the bacterial communities among the samples. These findings indicated that copper severely affected the performance and key microbial populations in the A2O system as well as disturbed the stability of the bacterial communities in the system, thus decreasing the removal efficiency. Copyright © 2016 Elsevier Ltd. All rights reserved.

Precursors for formation of copper selenide, indium selenide, copper indium diselenide, and/or copper indium gallium diselenide films

Science.gov (United States)

Curtis, Calvin J; Miedaner, Alexander; Van Hest, Maikel; Ginley, David S

2014-11-04

Liquid-based precursors for formation of Copper Selenide, Indium Selenide, Copper Indium Diselenide, and/or copper Indium Galium Diselenide include copper-organoselenides, particulate copper selenide suspensions, copper selenide ethylene diamine in liquid solvent, nanoparticulate indium selenide suspensions, and indium selenide ethylene diamine coordination compounds in solvent. These liquid-based precursors can be deposited in liquid form onto substrates and treated by rapid thermal processing to form crystalline copper selenide and indium selenide films.

Plant growth, development and change in GSH level in safflower (Carthamus tinctorius L. exposed to copper and lead

Directory of Open Access Journals (Sweden)

Li Shufen

2015-01-01

Full Text Available The effects of exposure to heavy metals, copper (Cu and lead (Pb in the soil, separately and in combination, were examined in Safflower (Carthamus tinctorius L.. Plant growth and development, GSH level and GSH2 expression at seedling, branching, and flowering stages were studied. Cu at lower concentrations had a stimulating effect on seedling height and root length. A significant positive correlation was observed between heavy metal concentrations and inhibition of plant growth. Plant height, root length and lateral root numbers decreased progressively with increasing concentrations of Cu and Pb. Except at the seedling stage, the metal mixture elicited a synergistic effect on safflower growth and development. The GSH content was significantly reduced in both safflower roots and leaves at increased concentrations of heavy metals, with the exception of the treatment with a low concentration of Cu that resulted in a slightl increase in GSH content at the seedling and branching stages. RT-PCR analysis revealed a negative correlation between GSH2 expression levels and metal concentration. Short exposure to low concentrations of Cu induce an increase in GSH synthesis to preserve normal plant growth, whereas prolonged exposure and large Cu and Pb concentrations affect the GSH metabolic chain, and are severely toxicity. The findings obtained in this study enhance our understanding of the role of the GSH pool in the response of plants to heavy metal-induced stress, and serve as a basis for improved cultivation of safflower.

Pharmacokinetics of prolonged-release tacrolimus and implications for use in solid organ transplant recipients.

Science.gov (United States)

Tanzi, Maria G; Undre, Nasrullah; Keirns, James; Fitzsimmons, William E; Brown, Malcolm; First, M Roy

2016-08-01

Prolonged-release tacrolimus was developed as a once-daily formulation with ethylcellulose as the excipient, resulting in slower release and reduction in peak concentration (Cmax ) for a given dose compared with immediate-release tacrolimus, which is administered twice daily. This manuscript reviews pharmacokinetic information on prolonged-release tacrolimus in healthy subjects, in transplant recipients converted from immediate-release tacrolimus, and in de novo kidney and liver transplant recipients. As with the immediate-release formulation, prolonged-release tacrolimus shows a strong correlation between trough concentration (Cmin ) and area under the 24-hour time-concentration curve (AUC24 ), indicating that trough whole blood concentrations provide an accurate measure of drug exposure. We present the pharmacokinetic similarities and differences between the two formulations, so that prescribing physicians will have a better understanding of therapeutic drug monitoring in patients receiving prolonged-release tacrolimus. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Nano Copper Induces Apoptosis in PK-15 Cells via a Mitochondria-Mediated Pathway.

Science.gov (United States)

Zhang, Hui; Chang, Zhenyu; Mehmood, Khalid; Abbas, Rao Zahid; Nabi, Fazul; Rehman, Mujeeb Ur; Wu, Xiaoxing; Tian, Xinxin; Yuan, Xiaodan; Li, Zhaoyang; Zhou, Donghai

2018-01-01

Nano-sized copper particles are widely used in various chemical, physical, and biological fields. However, earlier studies have shown that nano copper particles (40-100 μg/mL) can induce cell toxicity and apoptosis. Therefore, this study was conducted to investigate the role of nano copper in mitochondrion-mediated apoptosis in PK-15 cells. The cells were treated with different doses of nano copper (20, 40, 60, and 80 μg/mL) to determine the effects of apoptosis using acridine orange/ethidium bromide (AO/EB) fluorescence staining and a flow cytometry assay. The levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in the PK-15 cells were examined using commercially available kits. Moreover, the mRNA levels of the Bax, Bid, Caspase-3, and CYCS genes were assessed by real-time PCR. The results revealed that nano copper exposure induced apoptosis and changed the mitochondrial membrane potential. In addition, nano copper significantly altered the levels of the Bax, Bid, Caspase-3, and CYCS genes at a concentration of 40 μg/mL. To summarize, nano copper significantly (P nano copper can play an important role in inducing the apoptotic pathway in PK-15 cells, which may be the mechanism by which nano copper induces nephrotoxicity.

Physiologic effects of prolonged conducted electrical weapon discharge in ethanol-intoxicated adults.

Science.gov (United States)

Moscati, Ronald; Ho, Jeffrey D; Dawes, Donald M; Miner, James R

2010-06-01

This study examines the physiologic effects of prolonged conducted electrical weapon (CEW) exposure on alcohol-intoxicated adult subjects. Adult volunteers were recruited at a TASER International training conference. All subjects ingested mixed drinks until clinical intoxication or until a minimum breath alcohol level of 0.08 mg/dL was achieved. Blood samples for venous pH, Pco(2), bicarbonate, and lactate were measured in all subjects at baseline, immediately after alcohol ingestion, immediately after exposure to a 15-second TASER X26 discharge (Taser International Inc, Scottsdale, AZ), and 24 hours post-alcohol ingestion. Laboratory values were compared at sampling times using repeated-measure analysis of variance. A focused analysis comparing time points within groups was then performed using paired t tests. Twenty-two subjects were enrolled into the study. There was a decrease in pH and bicarbonate and an increase in lactate after alcohol ingestion. There was a further increase in lactate and drop in pH after CEW exposure. No subject experienced a significant adverse event. All values had returned to baseline levels at 24 hours except lactate, which demonstrated a small but clinically insignificant increase. Prolonged continuous CEW exposure in the setting of acute alcohol intoxication has no clinically significant effect on subjects in terms of markers of metabolic acidosis. The acidosis seen is consistent with what occurs with ethanol intoxication or moderate exertion. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Copper as a target for prostate cancer therapeutics: copper-ionophore pharmacology and altering systemic copper distribution

Science.gov (United States)

Denoyer, Delphine; Pearson, Helen B.; Clatworthy, Sharnel A.S.; Smith, Zoe M.; Francis, Paul S.; Llanos, Roxana M.; Volitakis, Irene; Phillips, Wayne A.; Meggyesy, Peter M.; Masaldan, Shashank; Cater, Michael A.

2016-01-01

Copper-ionophores that elevate intracellular bioavailable copper display significant therapeutic utility against prostate cancer cells in vitro and in TRAMP (Transgenic Adenocarcinoma of Mouse Prostate) mice. However, the pharmacological basis for their anticancer activity remains unclear, despite impending clinical trails. Herein we show that intracellular copper levels in prostate cancer, evaluated in vitro and across disease progression in TRAMP mice, were not correlative with copper-ionophore activity and mirrored the normal levels observed in patient prostatectomy tissues (Gleason Score 7 & 9). TRAMP adenocarcinoma cells harbored markedly elevated oxidative stress and diminished glutathione (GSH)-mediated antioxidant capacity, which together conferred selective sensitivity to prooxidant ionophoric copper. Copper-ionophore treatments [CuII(gtsm), disulfiram & clioquinol] generated toxic levels of reactive oxygen species (ROS) in TRAMP adenocarcinoma cells, but not in normal mouse prostate epithelial cells (PrECs). Our results provide a basis for the pharmacological activity of copper-ionophores and suggest they are amendable for treatment of patients with prostate cancer. Additionally, recent in vitro and mouse xenograft studies have suggested an increased copper requirement by prostate cancer cells. We demonstrated that prostate adenocarcinoma development in TRAMP mice requires a functional supply of copper and is significantly impeded by altered systemic copper distribution. The presence of a mutant copper-transporting Atp7b protein (tx mutation: A4066G/Met1356Val) in TRAMP mice changed copper-integration into serum and caused a remarkable reduction in prostate cancer burden (64% reduction) and disease severity (grade), abrogating adenocarcinoma development. Implications for current clinical trials are discussed. PMID:27175597

Effect of copper nanoparticles exposure in the physiology of the common carp (Cyprinus carpio: Biochemical, histological and proteomic approaches

Directory of Open Access Journals (Sweden)

Yugantak Raj Gupta

2016-12-01

Full Text Available Copper nanoparticles (Cu-NPs are serious water pollutants but their impact in teleosts performance remains poorly understood. In the present study, we have exposed juvenile carps (Cyprinus carpio, a freshwater teleost edible in India to two different doses (20 and 100 μg/L of Cu-NPs for seven days. The doses selected were eco-relevant considering the contamination levels of certain water resources. The results indicated that the activity oxidative stress enzymes catalase, superoxide dismutase, and glutathione-S-transferase were significantly increased in the kidney, liver and gills of the treated groups when compared to control. Histological analysis revealed that after exposure, disruption of the secondary lamellae of gills, liver damage with pyknotic nuclei and structural disarray of the kidney occurred. Proteomic analysis of the liver showed down-regulation of several proteins including the ferritin heavy chain, rho guanine nucleotide exchange factor 17-like, cytoglobin-1 and up-regulation of diphosphomevalonate decarboxylase and selenide & water dikinase-1. Taken together, the results of suggest that short-term exposure of juvenile carp to Cu-NPs causes oxidative stress and impart serious deleterious effects in the tissues which may affect fish growth and development.

Copper pellets simulating oral exposure to copper ammunition: Absence of toxicity in American kestrels (Falco sparverius)

Science.gov (United States)

Franson, J. Christian; Lahner, Lesanna L.; Meteyer, Carol U.; Rattner, Barnett A.

2012-01-01

To evaluate the potential toxicity of copper (Cu) in raptors that may consume Cu bullets, shotgun pellets containing Cu, or Cu fragments as they feed on wildlife carcasses, we studied the effects of metallic Cu exposure in a surrogate, the American kestrel (Falco sparverius). Sixteen kestrels were orally administered 5 mg Cu/g body mass in the form of Cu pellets (1.18–2.00 mm in diameter) nine times during 38 days and 10 controls were sham gavaged on the same schedule. With one exception, all birds retained the pellets for at least 1 h, but most (69%) regurgitated pellets during a 12-h monitoring period. Hepatic Cu concentrations were greater in kestrels administered Cu than in controls, but there was no difference in Cu concentrations in the blood between treated and control birds. Concentration of the metal-binding protein metallothionein was greater in male birds that received Cu than in controls, whereas concentrations in female birds that received Cu were similar to control female birds. Hepatic Cu and metallothionein concentrations in kestrels were significantly correlated. Histopathologic alterations were noted in the pancreas of four treated kestrels and two controls, but these changes were not associated with hepatic or renal Cu concentrations, and no lesions were seen in other tissues. No clinical signs were observed, and there was no treatment effect on body mass; concentrations of Cu, hemoglobin, or methemoglobin in the blood; or Cu concentrations in kidney, plasma biochemistries, or hematocrit. Based on the parameters we measured, ingested Cu pellets pose little threat to American kestrels (and presumably phylogenetically related species), although the retention time of pellets in the stomach was of relatively short duration. Birds expected to regurgitate Cu fragments with a frequency similar to kestrels are not likely to be adversely affected by Cu ingestion, but the results of our study do not completely rule out the potential for toxicity in

Native copper as a natural analogue for copper canisters

International Nuclear Information System (INIS)

Marcos, N.

1989-12-01

This paper discusses the occurrence of native copper as found in geological formations as a stability analogue of copper canisters that are planned to be used for the disposal of spent nuclear fuel in the Finnish bedrock. A summary of several publications on native copper occurrences is presented. The present geochemical and geohydrological conditions in which copper is met with in its metallic state show that metallic copper is stable in a wide range of temperatures. At low temperatures native copper is found to be stable where groundwater has moderate pH (about 7), low Eh (< +100 mV), and low total dissolved solids, especially chloride. Microscopical and microanalytical studies were carried out on a dozen of rock samples containing native copper. The results reveal that the metal shows no significant alteration. Only the surface of copper grains is locally coated. In the oldest samples there exist small corrosion cracks; the age of the oldest samples is over 1,000 million years. A review of several Finnish groundwater studies suggests that there are places in Finland where the geohydrological conditions are favourable for native copper stability. (orig.)

Formation of copper-indium-selenide and/or copper-indium-gallium-selenide films from indium selenide and copper selenide precursors

Science.gov (United States)

Curtis, Calvin J [Lakewood, CO; Miedaner, Alexander [Boulder, CO; Van Hest, Maikel [Lakewood, CO; Ginley, David S [Evergreen, CO; Nekuda, Jennifer A [Lakewood, CO

2011-11-15

Liquid-based indium selenide and copper selenide precursors, including copper-organoselenides, particulate copper selenide suspensions, copper selenide ethylene diamine in liquid solvent, nanoparticulate indium selenide suspensions, and indium selenide ethylene diamine coordination compounds in solvent, are used to form crystalline copper-indium-selenide, and/or copper indium gallium selenide films (66) on substrates (52).

COPPER AND COPPER-CONTAINING PESTICIDES: METABOLISM, TOXICITY AND OXIDATIVE STRESS

Directory of Open Access Journals (Sweden)

Viktor Husak

2015-05-01

Full Text Available The purpose of this paper is to provide a brief review of the current knowledge regarding metabolism and toxicity of copper and copper-based pesticides in living organisms. Copper is an essential trace element in all living organisms (bacteria, fungi, plants, and animals, because it participates in different metabolic processes and maintain functions of organisms. The transport and metabolism of copper in living organisms is currently the subject of many studies. Copper is absorbed, transported, distributed, stored, and excreted in the body via the complex of homeostatic processes, which provide organisms with a needed constant level of this micronutrient and avoid excessive amounts. Many aspects of copper homeostasis were studied at the molecular level. Copper based-pesticides, in particularly fungicides, bacteriocides and herbicides, are widely used in agricultural practice throughout the world. Copper is an integral part of antioxidant enzymes, particularly copper-zinc superoxide dismutase (Cu,Zn-SOD, and plays prominent roles in iron homeostasis. On the other hand, excess of copper in organism has deleterious effect, because it stimulates free radical production in the cell, induces lipid peroxidation, and disturbs the total antioxidant capacity of the body. The mechanisms of copper toxicity are discussed in this review also.

Assessment of the Bioaccessibility of Micronized Copper Wood on Simulated Stomach Fluid

Data.gov (United States)

U.S. Environmental Protection Agency — The widespread use of copper-treated lumber has increased the potential for human exposure. Moreover, there is a lack of information on the fate and behavior of...

Effects of copper particles on a model septic system's function and microbial community.

Science.gov (United States)

Taylor, Alicia A; Walker, Sharon L

2016-03-15

There is concern surrounding the addition of nanoparticles into consumer products due to toxicity potential and the increased risk of human and environmental exposures to these particles. Copper nanoparticles are found in many common consumer goods; therefore, the disposal and subsequent interactions between potentially toxic Cu-based nanoparticles and microbial communities may have detrimental impacts on wastewater treatment processes. This study investigates the effects of three copper particles (micron- and nano-scale Cu particles, and a nano-scale Cu(OH)2-based fungicide) on the function and operation of a model septic tank. Septic system analyses included water quality evaluations and microbial community characterizations to detect changes in and relationships between the septic tank function and microbial community phenotype/genotype. As would be expected for optimal wastewater treatment, biological oxygen demand (BOD5) was reduced by at least 63% during nano-scale Cu exposure, indicating normal function. pH was reduced to below the optimum anaerobic fermentation range during the micro Cu exposure, suggesting incomplete degradation of organic waste may have occurred. The copper fungicide, Cu(OH)2, caused a 57% increase in total organic carbon (TOC), which is well above the typical range for septic systems and also corresponded to increased BOD5 during the majority of the Cu(OH)2 exposure. The changes in TOC and BOD5 demonstrate that the system was improperly treating waste. Overall, results imply individual exposures to the three Cu particles caused distinct disruptions in septic tank function. However, it was observed that the system was able to recover to typical operating conditions after three weeks post-exposure. These results imply that during periods of Cu introduction, there are likely pulses of improper removal of total organic carbon and significant changes in pH not in the optimal range for the system. Copyright © 2016 Elsevier Ltd. All rights

Uptake and internalisation of copper by three marine microalgae: comparison of copper-sensitive and copper-tolerant species.

Science.gov (United States)

Levy, Jacqueline L; Angel, Brad M; Stauber, Jennifer L; Poon, Wing L; Simpson, Stuart L; Cheng, Shuk Han; Jolley, Dianne F

2008-08-29

Although it has been well established that different species of marine algae have different sensitivities to metals, our understanding of the physiological and biochemical basis for these differences is limited. This study investigated copper adsorption and internalisation in three algal species with differing sensitivities to copper. The diatom Phaeodactylum tricornutum was particularly sensitive to copper, with a 72-h IC50 (concentration of copper to inhibit growth rate by 50%) of 8.0 microg Cu L(-1), compared to the green algae Tetraselmis sp. (72-h IC50 47 microg Cu L(-1)) and Dunaliella tertiolecta (72-h IC50 530 microg Cu L(-1)). At these IC50 concentrations, Tetraselmis sp. had much higher intracellular copper (1.97+/-0.01 x 10(-13)g Cu cell(-1)) than P. tricornutum (0.23+/-0.19 x 10(-13)g Cu cell(-1)) and D. tertiolecta (0.59+/-0.05 x 10(-13)g Cu cell(-1)), suggesting that Tetraselmis sp. effectively detoxifies copper within the cell. By contrast, at the same external copper concentration (50 microg L(-1)), D. tertiolecta appears to better exclude copper than Tetraselmis sp. by having a slower copper internalisation rate and lower internal copper concentrations at equivalent extracellular concentrations. The results suggest that the use of internal copper concentrations and net uptake rates alone cannot explain differences in species-sensitivity for different algal species. Model prediction of copper toxicity to marine biota and understanding fundamental differences in species-sensitivity will require, not just an understanding of water quality parameters and copper-cell binding, but also further knowledge of cellular detoxification mechanisms.

Decision-making about chronic radiation exposure to the public. New recommendations from the ICRP

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, A.J. [Division of Radiation and Waste Safety, International Atomic Energy Agency, Vienna (Austria)

2000-05-01

The paper discusses decision-making in situations of chronic exposure within the framework of a forthcoming related ICRP report on the subject which has been produced by an ICRP Task Group chaired by the author. This ICRP report will provide guidance on the application of the ICRP System of Radiological Protection to prolonged exposure situations afflicting members of the public. It will address the general application of the System to the control of prolonged exposures resulting from practices and to the undertaking of interventions in prolonged exposure situations, and will provide recommendations on generic reference levels for such interventions. It will also consider some specific situations and will discuss a number of issues that have been of concern, namely: natural radiation sources that may give rise to high doses; the restoration and rehabilitation of sites where human activities involving radioactive substances have been carried out; the return to 'normality' following an accident that has released radioactive substances to the environment; and the global marketing of commodities for public consumption that contain relatively high levels of radioactive substances. Annexes will provide some examples of prolonged exposure situations and will discuss the radiological protection quantities, radiation-induced health effects and aspects of the System of Radiological Protection relevant to prolonged exposure. The quantitative recommendations for prolonged exposures provided in the report will be as follows: generic reference levels for intervention, in terms of existing annual doses, of < or approx. 100 mSv, above which intervention is almost always justifiable (situations for which the annual dose threshold for deterministic effects in relevant organs is exceeded will almost always require intervention), and of < or approx.10 mSv, below which intervention is not likely to be justifiable (and above which it may be necessary); intervention exemption

Prenatal nicotinic exposure upregulates pulmonary C-fiber NK1R expression to prolong pulmonary C-fiber-mediated apneic response

Energy Technology Data Exchange (ETDEWEB)

Zhao, Lei; Zhuang, Jianguo; Zang, Na; Lin, Yong [Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, NM (United States); Lee, Lu-Yuan [Department of Physiology, University of Kentucky, Lexington, KY (United States); Xu, Fadi, E-mail: fxu@lrri.org [Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, NM (United States); Department of Physiology, University of Kentucky, Lexington, KY (United States)

2016-01-01

Prenatal nicotinic exposure (PNE) prolongs bronchopulmonary C-fiber (PCF)-mediated apneic response to intra-atrial bolus injection of capsaicin in rat pups. The relevant mechanisms remain unclear. Pulmonary substance P and adenosine and their receptors (neurokinin-A receptor, NK1R and ADA{sub 1} receptor, ADA{sub 1}R) and transient receptor potential cation channel subfamily V member 1 (TRPV1) expressed on PCFs are critical for PCF sensitization and/or activation. Here, we compared substance P and adenosine in BALF and NK1R, ADA{sub 1}R, and TRPV1 expression in the nodose/jugular (N/J) ganglia (vagal pulmonary C-neurons retrogradely labeled) between Ctrl and PNE pups. We found that PNE failed to change BALF substance P and adenosine content, but significantly upregulated both mRNA and protein TRPV1 and NK1R in the N/J ganglia and only NK1R mRNA in pulmonary C-neurons. To define the role of NK1R in the PNE-induced PCF sensitization, the apneic response to capsaicin (i.v.) without or with pretreatment of SR140333 (a peripheral and selective NK1R antagonist) was compared and the prolonged apnea by PNE significantly shortened by SR140333. To clarify if the PNE-evoked responses depended on action of nicotinic acetylcholine receptors (nAChRs), particularly α7nAChR, mecamylamine or methyllycaconitine (a general nAChR or a selective α7nAChR antagonist) was administrated via another mini-pump over the PNE period. Mecamylamine or methyllycaconitine eliminated the PNE-evoked mRNA and protein responses. Our data suggest that PNE is able to elevate PCF NK1R expression via activation of nAChRs, especially α7nAChR, which likely contributes to sensitize PCFs and prolong the PCF-mediated apneic response to capsaicin. - Highlights: • PNE upregulated NK1R and TRPV1 gene and protein expression in the N/J ganglia. • PNE only elevated NK1R mRNA in vagal pulmonary C-neurons. • Blockage of peripheral NK1R reduced the PNE-induced PCF sensitization. • PNE induced gene and protein

Prolonged ultraviolet light-induced erythema and the cutaneous carcinoma phenotype

International Nuclear Information System (INIS)

Tanenbaum, L.; Parrish, J.A.; Haynes, H.A.; Fitzpatrick, T.B.; Pathak, M.A.

1976-01-01

A considerable amount of evidence exists in support of the role of ultraviolet radiation as a major etiologic factor in human skin cancer, both melanoma and carcinoma types. On the basis of epidemiologic studies a phenotype has been described which helps to identify the persons who are more susceptible to skin cancer. In an attempt to further define this population, patients with cutaneous carcinoma and a normal control group were exposed to artificial ultraviolet light (UVL) and the erythema and tanning responses of each group were measured over a 21-day period. UVL-induced erythema was prolonged in a significantly higher percentage of patients with skin cancer than in control patients, lasting two to three weeks after single exposures to 6 and 8 times the patient's minimal erythema dose. The presence of prolonged erythema correlated with this history of previous skin cancer but did not correlate with other established risk factors for cutaneous carcinoma, i.e., fair skin, light hair and light eyes, easy sunburning and poor tanning, and Celtic ancestry. Prolonged erythema following UVL radiation may therefore represent an additional risk factor and help to identify the skin cancer-susceptible population

Prolonged Exposure Therapy For Post Traumatic Stress Disorder

OpenAIRE

Levent SÜTÇÝGÝL; Selçuk ASLAN

2012-01-01

Post-traumatic Stress Disorder (PTSD) is a psychiatric illness that usually develops after an event that threatens one’s life and body integrity and it affects quality of life and impairs social functioning significantly. Many studies have shown therapeutic effect of cognitive behavioral therapies on posttraumatic stress disorder, so that these therapies take part in the first step of treatment guides. Exposure is a practice that is generally used to reduce pathological fear and related ...

Transcriptional response of the mussel Mytilus galloprovincialis (Lam. following exposure to heat stress and copper.

Directory of Open Access Journals (Sweden)

Alessandro Negri

Full Text Available Global warming is a major factor that may affect biological organization, especially in marine ecosystems and in coastal areas that are particularly subject to anthropogenic pollution. We evaluated the effects of simultaneous changes in temperature and copper concentrations on lysosomal membrane stability (N-acetyl-hexosaminidase activity and malondialdehyde accumulation (MDA in the gill of the blue mussel Mytilus galloprovincialis (Lam.. Temperature and copper exerted additive effects on lysosomal membrane stability, exacerbating the toxic effects of metal cations present in non-physiological concentrations. Mussel lysosomal membrane stability is known to be positively related to scope for growth, indicating possible effects of increasing temperature on mussel populations in metal-polluted areas. To clarify the molecular response to environmental stressors, we used a cDNA microarray with 1,673 sequences to measure the relative transcript abundances in the gills of mussels exposed to copper (40 µg/L and a temperature gradient (16°C, 20°C, and 24°C. In animals exposed only to heat stress, hierarchical clustering of the microarray data revealed three main clusters, which were largely dominated by down-regulation of translation-related differentially expressed genes, drastic up-regulation of protein folding related genes, and genes involved in chitin metabolism. The response of mussels exposed to copper at 24°C was characterized by an opposite pattern of the genes involved in translation, most of which were up-regulated, as well as the down-regulation of genes encoding heat shock proteins and "microtubule-based movement" proteins. Our data provide novel information on the transcriptomic modulations in mussels facing temperature increases and high copper concentrations; these data highlight the risk of marine life exposed to toxic chemicals in the presence of temperature increases due to climate change.

Accumulation of copper by the aquatic macrophyte Salvinia biloba Raddi (Salviniaceae

Directory of Open Access Journals (Sweden)

F. Freitas

2017-07-01

Full Text Available Abstract Aquatic macrophytes have properties and mechanisms which are useful for the removal of substances in solution, commonly used in phytoremediation processes in aquatic environments. This study evaluated the performance of copper (Cu accumulation by Salvinia biloba Raddi (Salviniaceae in different metal concentrations (1, 3 and 5 µg mL-1, as well as the control treatment, measured at intervals of 0, 7 and 14 days under laboratory conditions, with control as to pH and luminosity. After the experiment, the S. biloba biomass was washed, kiln dried, crushed and subjected to the process of digestion, and subsequently the accumulated copper content was determined by atomic absorption spectroscopy. The results showed that S. biloba is apt at accumulating copper, varying significantly between different treatments and days of exposure to the contaminant, as well as its interaction (treatment × days. The highest accumulation values were observed in treatment with 5 µg mL-1, which at 14 days, with 11,861 µg g-1 of copper. We observed symptoms of toxicity and mortality in plants, probably indicating the effect of copper on the species when at high levels. Salvinia biloba is an efficient species in the removal of copper in solution, its recommendation as a remediating agent in aquatic ecosystems being possible.

Evaluation of benzodiazepines and zolpidem in nails and their stability after prolonged exposure to chlorinated water.

Science.gov (United States)

Moretti, Matteo; Andrello, Luisa; Visonà, Silvia; Vignali, Claudia; Groppi, Angelo; Freni, Francesca; Osculati, Antonio; Tajana, Luca; Morini, Luca

2018-04-15

The study aims the development and validation of a LC-MS/MS method for the identification and quantification of benzodiazepines and zolpidem in nails as alternative keratinized matrix to hair in long-term monitoring of anxiolytic and hypnotic drugs. Both fingernail and toenail samples (1-2 mm) were collected by clipping the excess overhang of the nail from volunteers and from postmortem cases. They were washed twice with organic solvents, dried under nitrogen stream, pulverized, immersed in a methanol solution (internal standard: diazepam-D5) and sonicated up to two hours. The solution was then direct injected in the LC-MS/MS system. Mass spectrometry was set in MRM mode, selecting two transitions for each substance. 32 analytes among benzodiazepines, metabolites and hypnotics were included in the list. The method fulfilled the internationally required criteria for validation. Limits of detection ranged from 0.03 pg/mg (zolpidem) to 13.1 pg/mg (bromazepam). 9 subjects under therapy were positive at 7 different benzodiazepines and/or metabolites (lorazepam, desalkylflurazepam, bromazepam, diazepam, alprazolam, lormetazepam and prazepam), while 5 molecules were measured in 4 postmortem cases (diazepam, desmethyldiazepam, delorazepam, 7-aminoclonazepam and zolpidem). In vitro experiments on eight authentic samples suggested that benzodiazepines in nails are influenced by the prolonged exposure to chlorinated water. Copyright © 2018 Elsevier B.V. All rights reserved.

Monitoring and control of occupational radiation exposure in Switzerland

International Nuclear Information System (INIS)

Moser, M.

1997-01-01

Occupational exposure is the most prominent example for the prolonged exposure to low level ionizing radiation characterized by low doses and dose rates. In this paper the occupational exposure in Switzerland is presented and the regulatory control of this exposure in the framework of the new radiation protection regulations is discussed. (author)

[Secondary traumatization/trauma among employees in palliative care units--the products of prolonged repeated exposure to suffering and death].

Science.gov (United States)

Samson, Tali; Shvartzman, Pesach

2012-11-01

The palliative care philosophy accepts the dying process as a natural phase in the life cycle and provides quality end of life care for terminal patients and their family members. Prolonged exposure to the physical symptoms and pain, as well as the psychological, spiritual, and existential suffering of the dying patient, may be fertile ground for the development of post-traumatic stress symptoms among palliative care teams. Work-related positive outcomes (such as compassion, satisfaction and meaning) and work-related negative outcomes (such as compassion fatigue, secondary traumatization and burnout) can exist side by side, and the unique balance between them will determine the quality of life of the worker. This review presents the current knowledge about the prevalence and causes of work-related stress outcomes among palliative care teams and measurement tools that are available. The literature review discusses secondary traumatization in palliative care teams and relevant messages for the development of treatment options, burnout prevention programs and support interventions for professionals who lead the care for terminal patients in Israel.

The effect of boron implantation on the corrosion behaviour, microhardness and contact resistance of copper and silver surfaces

International Nuclear Information System (INIS)

Henriksen, O.; Johnson, E.; Johansen, A.; Sarholt-Kristensen, L.

1986-01-01

In order to investigate the influence of boron implantation on the corrosion resistance of electrical contacts, a number of pure copper, pure silver and copper edge connector samples have been implanted with boron (40 keV) to fluences of 5.10 20 m -2 and 2.10 21 m -2 . Atmospheric corrosion tests of the implanted species were conducted using the following exposures: H 2 S (12.5 ppm, 4 days), SO 2 (25 ppm, 21 days), saltfog (5% NaCl, 1 day), moist air (93% RH, 56 days), and hot/dry air (70 C, 56 days). The boron implantations lead to a significant reduction in the sulphidation rate of copper and silver. The corrosive film formed during exposure in H 2 S and SO 2 atmospheres is confined to pitted regions on the implanted areas, while a thick and relatively uniform film formation is observed on the unimplanted samples. The corrosion resistance of copper and silver in saltfog atmosphere is somewhat improved by boron implantation, whilst the results from exposures to moist air or hot/dry air are inconclusive. The improved corrosion behaviour is accompanied by an increase in the contact resistance and in the microhardness of the implanted samples. (orig.)

Synergistic interaction between prolonged increased glycemic exposure and mildly increased urinary albumin excretion on diabetic retinopathy.

Science.gov (United States)

Moon, Shinje; Yoo, Hyung-Joon; Ahn, You-Hern; Kim, Gheun-Ho; Yu, Jae Myung; Park, Joon-Sung

2018-01-01

The association of mild increase in urinary albumin excretion with diabetic retinopathy (DR) in clinical studies is controversial. The aim of this study is to clarify the interaction between increased glycemic exposure and mild increase in urinary albumin excretion on risk of DR.Data were collected from the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2012. Overall, data from 953 participants without microalbuminuria (477 men and 476 women) were assessed. Logistic regression analysis was constructed to evaluate the association between DR and related clinical parameters, including urinary albumin-creatinine ratio (UACR, mg/g creatinine). The biological interaction of glycemic status and UACR on DR was evaluated by 3 indices: RERI, the relative excess risk due to the interaction; AP, the attributable proportion due to the interaction; and S, the additive interaction index of synergy.We found that UACR, glycated hemoglobin (HbA1c), and diabetic duration were deeply associated with increased risk of DR (UACR, odds ratio [OR] = 1.04, 95% confidence interval [CI] = 1.02-1.07; HbA1c, OR = 1.16, 95% CI = 1.04-1.30; diabetic duration, OR = 1.06, 95% CI = 1.04-1.07). Furthermore, our interaction analysis demonstrated that synergistic interaction between HbA1c and UACR on development of DR was prominent in participants with diabetic duration of ≥10 years (adjusted RERI = 0.92, 95% CI = 0.10-1.74; adjusted AP = 0.29, 95% CI = -0.82-1.41; adjusted S = 1.76, 95% CI = 1.27-2.25), but not subjects with shorter diabetic duration.These findings imply that there is the interaction between prolonged hyperglycemic exposure and increased urinary albumin excretion may exert additive synergistic effect on vascular endothelial dysfunction in the eye, even before the appearance of overt diabetic nephropathy. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

Antenatal exposure to Ureaplasma species exacerbates bronchopulmonary dysplasia synergistically with subsequent prolonged mechanical ventilation in preterm infants.

Science.gov (United States)

Inatomi, Tadashi; Oue, Shinya; Ogihara, Tohru; Hira, Seigo; Hasegawa, Masashi; Yamaoka, Shigeo; Yasui, Masako; Tamai, Hiroshi

2012-03-01

The presence of microorganisms in gastric fluid in neonates at birth is postulated to reflect antenatal infection and also to be associated with the development of bronchopulmonary dysplasia (BPD). A logistic regression analysis, after controlling for other risk factors, indicated that Ureaplasma-positive infants were not at increased risk for moderate/severe BPD (adjusted odds ratio (OR): 2.58, 95% confidence interval (CI): 0.57-6.89, P = 0.12). However, the association between the presence of Ureaplasma species and the risk for moderate/severe BPD increased significantly in infants on mechanical ventilation (MV) ≥2 wk (adjusted OR: 4.17, 95% CI: 1.62-44.1, P = 0.009). An analysis using a lung injury marker indicated that Ureaplasma-positive infants with MV ≥2 wk, but not other infants, showed higher serum KL-6 levels in samples taken from cord blood, and that KL-6 levels increased time-dependently up to 4 wk of age. Antenatal exposure to Ureaplasma species induces lung injury prior to birth and synergistically contributes to the development of BPD in infants requiring prolonged MV (≥2 wk). We recovered gastric fluid specimens from 122 infants with gestational age (GA) Ureaplasma-positive or Ureaplasma-negative infants.

Influence of phosphorus on the creep ductility of copper

International Nuclear Information System (INIS)

Sandström, Rolf; Wu, Rui

2013-01-01

Around 1990 it was discovered that pure copper could have extra low creep ductility in the temperature interval 180–250 °C. The material was intended for use in canisters for nuclear waste disposal. Although extra low creep ductility was not observed much below 180 °C and the temperature in the canister will never exceed 100 °C, it was feared that the creep ductility could reach low values at lower temperatures after long term exposure. If 50 ppm phosphorus was added to the copper the low creep ductility disappeared. A creep cavitation model is presented that can quantitatively describe the cavitation behaviour in uniaxial and multiaxial creep tests as well as the observed creep ductility for copper with and without phosphorus. A so-called double ledge model has been introduced that demonstrates why the nucleation rate of creep cavities is often proportional to the creep rate. The phosphorus agglomerates at the grain boundaries and limits their local deformation and thereby reduces the formation and growth of cavities. This explains why extra low creep ductility does not occur in phosphorus alloyed copper

Prolonged Exposure of Cortical Neurons to Oligomeric Amyloid-β Impairs NMDA Receptor Function Via NADPH Oxidase-Mediated ROS Production: Protective Effect of Green Tea (--Epigallocatechin-3-Gallate

Directory of Open Access Journals (Sweden)

Yan He

2011-01-01

Full Text Available Excessive production of Aβ (amyloid β-peptide has been shown to play an important role in the pathogenesis of AD (Alzheimer's disease. Although not yet well understood, aggregation of Aβ is known to cause toxicity to neurons. Our recent study demonstrated the ability for oligomeric Aβ to stimulate the production of ROS (reactive oxygen species in neurons through an NMDA (N-methyl-D-aspartate-dependent pathway. However, whether prolonged exposure of neurons to aggregated Aβ is associated with impairment of NMDA receptor function has not been extensively investigated. In the present study, we show that prolonged exposure of primary cortical neurons to Aβ oligomers caused mitochondrial dysfunction, an attenuation of NMDA receptor-mediated Ca2+ influx and inhibition of NMDA-induced AA (arachidonic acid release. Mitochondrial dysfunction and the decrease in NMDA receptor activity due to oligomeric Aβ are associated with an increase in ROS production. Gp91ds-tat, a specific peptide inhibitor of NADPH oxidase, and Mn(III-tetrakis(4-benzoic acid-porphyrin chloride, an ROS scavenger, effectively abrogated Aβ-induced ROS production. Furthermore, Aβ-induced mitochondrial dysfunction, impairment of NMDA Ca2+ influx and ROS production were prevented by pretreatment of neurons with EGCG [(–-epigallocatechin-3-gallate], a major polyphenolic component of green tea. Taken together, these results support a role for NADPH oxidase-mediated ROS production in the cytotoxic effects of Aβ, and demonstrate the therapeutic potential of EGCG and other dietary polyphenols in delaying onset or retarding the progression of AD.

Corrosion of copper in oxygen-deficient groundwater with and without deep bedrock micro-organisms: Characterisation of microbial communities and surface processes

Energy Technology Data Exchange (ETDEWEB)

Huttunen-Saarivirta, E., E-mail: elina.huttunen-saarivirta@vtt.fi [VTT Technical Research Centre of Finland, Materials Performance, Kemistintie 3, FI-02044 VTT (Finland); Rajala, P. [VTT Technical Research Centre of Finland, Materials Performance, Kemistintie 3, FI-02044 VTT (Finland); Bomberg, M. [VTT Technical Research Centre of Finland, Geobiotechnology, Tietotie 2, FI-02044 VTT (Finland); Carpén, L. [VTT Technical Research Centre of Finland, Materials Performance, Kemistintie 3, FI-02044 VTT (Finland)

2017-02-28

Highlights: • Copper was exposed to groundwater with and without deep bedrock micro-organisms. • Biofilm composition was determined and correlated with the behaviour of copper. • Under biotic conditions, the film of Cu{sub 2}S formed on copper surfaces. • Bacterial pool was in a key role for the morphology and properties of Cu{sub 2}S film. • Under abiotic conditions, Cu{sub 2}O systematically developed on copper surfaces. - Abstract: Copper specimens were exposed to oxygen-deficient artificial groundwater in the presence and absence of micro-organisms enriched from the deep bedrock of the planned nuclear waste repository site at Olkiluoto island on the western coast of Finland. During the exposure periods of 4 and 10 months, the copper specimens were subjected to electrochemical measurements. The biofilm developed on the specimens and the water used in the exposures were subjected to microbiological analyses. Changes in the water chemistry were also determined and surfaces of the copper specimens were characterized with respect to the morphology and composition of the formed corrosion products. The results showed that under biotic conditions, redox of the water and open circuit potential (OCP) of the copper specimens were generally negative and resulted in the build-up of a copper sulphide, Cu{sub 2}S, layer due to the activity of sulphate-reducing bacteria (SRB) that were included in the system. In the 4-month test, the electrochemical behaviour of the specimens changed during the exposure and alphaproteobactria Rhizobiales were the dominant bacterial group in the biofilm where the highest corrosion rate was observed. In the 10-month test, however, deltaproteobacteria SRB flourished and the initial electrochemical behaviour and the low corrosion rate of the copper were retained until the end of the test period. Under abiotic conditions, the positive water redox potential and specimen OCP correlated with the formation of copper oxide, Cu{sub 2}O

Corrosion of copper in oxygen-deficient groundwater with and without deep bedrock micro-organisms: Characterisation of microbial communities and surface processes

International Nuclear Information System (INIS)

Huttunen-Saarivirta, E.; Rajala, P.; Bomberg, M.; Carpén, L.

2017-01-01

Highlights: • Copper was exposed to groundwater with and without deep bedrock micro-organisms. • Biofilm composition was determined and correlated with the behaviour of copper. • Under biotic conditions, the film of Cu_2S formed on copper surfaces. • Bacterial pool was in a key role for the morphology and properties of Cu_2S film. • Under abiotic conditions, Cu_2O systematically developed on copper surfaces. - Abstract: Copper specimens were exposed to oxygen-deficient artificial groundwater in the presence and absence of micro-organisms enriched from the deep bedrock of the planned nuclear waste repository site at Olkiluoto island on the western coast of Finland. During the exposure periods of 4 and 10 months, the copper specimens were subjected to electrochemical measurements. The biofilm developed on the specimens and the water used in the exposures were subjected to microbiological analyses. Changes in the water chemistry were also determined and surfaces of the copper specimens were characterized with respect to the morphology and composition of the formed corrosion products. The results showed that under biotic conditions, redox of the water and open circuit potential (OCP) of the copper specimens were generally negative and resulted in the build-up of a copper sulphide, Cu_2S, layer due to the activity of sulphate-reducing bacteria (SRB) that were included in the system. In the 4-month test, the electrochemical behaviour of the specimens changed during the exposure and alphaproteobactria Rhizobiales were the dominant bacterial group in the biofilm where the highest corrosion rate was observed. In the 10-month test, however, deltaproteobacteria SRB flourished and the initial electrochemical behaviour and the low corrosion rate of the copper were retained until the end of the test period. Under abiotic conditions, the positive water redox potential and specimen OCP correlated with the formation of copper oxide, Cu_2O. Furthermore, in the absence of

Electrical conduction in composites containing copper core-copper

Indian Academy of Sciences (India)

Composites of nanometre-sized copper core-copper oxide shell with diameters in the range 6.1 to 7.3 nm dispersed in a silica gel were synthesised by a technique comprising reduction followed by oxidation of a suitably chosen precursor gel. The hot pressed gel powders mixed with nanometre-sized copper particles ...

CCS and SOD1 mRNA are reduced after copper supplementation in peripheral mononuclear cells of individuals with high serum ceruloplasmin concentration.

Science.gov (United States)

Suazo, Miriam; Olivares, Felipe; Mendez, Marco A; Pulgar, Rodrigo; Prohaska, Joseph R; Arredondo, Miguel; Pizarro, Fernando; Olivares, Manuel; Araya, Magdalena; González, Mauricio

2008-04-01

The limits of copper homeostatic regulation in humans are not known, making it difficult to define the milder effects of early copper excess. Furthermore, a robust assay to facilitate the detection of early stages of copper excess is needed. To address these issues, we assessed changes in relative mRNA abundance of methallothionein 2A (MT2A), prion (PrP), amyloid precursor-like protein 2 (APLP2), Cu/Zn superoxide dismutase (SOD1) and its copper chaperone (CCS) in peripheral mononuclear cells (PMNCs) from healthy adults representing the 5% highest and lowest extremes in the distribution curve of serum ceruloplasmin (Cp) concentrations of 800 individuals. The intracellular Cu content was also determined. PMNCs were isolated from individuals before and after exposure to a single daily dose of 10 mg Cu (as CuSO(4)) for 2 months. Results showed that although there were fluctuations in serum Cp values of the samples assessed before copper exposure, no significant differences were observed in cell copper content or in the relative abundance of MT2A, PrP and APLP2 transcripts in PMNCs. Also, these values were not modified after copper supplementation. However, CCS and SOD1 mRNA levels were reduced in PMNCs after copper supplementation in the individuals with the high Cp values, suggesting that they should be further explored as biomarkers of moderate copper overload in humans.

Anti fouling effect of two saturated copper coatings applied on carbon steel structures

International Nuclear Information System (INIS)

Guiamet, P. S.; Gomez de Saravia, S. G.

2008-01-01

Biofouling is the colonization of man-made substrata by sessile organisms. The aim of this paper is to evaluate the performance of two anti fouling saturated copper coating. Bioassays were carried out at a harbor in Argentine (38 degree centigrade 02' S-57 degree centigrade 32'W). during six months, one series of pipes and panels were removed monthly to estimate the recruitment of macro and micro fouling species and immediately replaced by clean ones. Another series was removed from the beginning of exposure to monitor the development of the established community (accumulative pipes and panels along six months). Data obtained from control (without a saturated copper coating) and saturated-copper coated pipes and panels were compared in order to estimate performance of the coating. One of two saturated copper coating demonstrated a good effect anti fouling. (Author) 25 refs

Carcinogenic risk of chromium, copper and arsenic in CCA-treated wood

International Nuclear Information System (INIS)

Ohgami, Nobutaka; Yamanoshita, Osamu; Thang, Nguyen Dinh; Yajima, Ichiro; Nakano, Chihiro; Wenting, Wu; Ohnuma, Shoko

2015-01-01

We showed that 2.1% of 233 pieces of lumber debris after the Great East Japan Earthquake was chromated copper arsenate (CCA)-treated wood. Since hexavalent chromium (Cr), copper (Cu) and pentavalent arsenic (As) in the debris may be diffused in the air via incineration, we exposed human lung normal (BEAS-2B) and carcinoma (A549) cells to Cr, Cu and As at the molar ratio in a representative CCA-treated wood. Co-exposure to 0.10 μM Cr and 0.06 μM As, which solely had no effect on colony formation, synergistically promoted colony formation in BEAS-2B cells, but not A549 cells, with activation of the PI3K/AKT pathway. Sole exposure and co-exposure to Cu showed limited effects. Since previous reports showed Cr and As concentrations to which human lungs might be exposed, our results suggest the importance to avoid diffusion of Cr and As in the air via incineration of debris including CCA-treated wood after the disaster. - Highlights: • CCA-treated wood was found in debris after the Great East Japan Earthquake in 2011. • Carcinogenic risk of CCA-treated woods was evaluated with human lung cell lines. • Co-exposure to Cr and As synergistically promoted colony formation. • Co-exposure to Cr and As synergistically activated the PI3/AKT pathway. • Effects of sole exposure and co-exposure to Cu on colony formation were limited. - Co-exposure to Cr and As, but not Cu, in CCA-treated wood debris from the Great East Japan Earthquake showed carcinogenicity in vitro.

Stress-altered synaptic plasticity and DAMP signaling in the hippocampus-PFC axis; elucidating the significance of IGF-1/IGF-1R/CaMKIIα expression in neural changes associated with a prolonged exposure therapy.

Science.gov (United States)

Ogundele, Olalekan M; Ebenezer, Philip J; Lee, Charles C; Francis, Joseph

2017-06-14

Traumatic stress patients showed significant improvement in behavior after a prolonged exposure to an unrelated stimulus. This treatment method attempts to promote extinction of the fear memory associated with the initial traumatic experience. However, the subsequent prolonged exposure to such stimulus creates an additional layer of neural stress. Although the mechanism remains unclear, prolonged exposure therapy (PET) likely involves changes in synaptic plasticity, neurotransmitter function and inflammation; especially in parts of the brain concerned with the formation and retrieval of fear memory (Hippocampus and Prefrontal Cortex: PFC). Since certain synaptic proteins are also involved in danger-associated molecular pattern signaling (DAMP), we identified the significance of IGF-1/IGF-1R/CaMKIIα expression as a potential link between the concurrent progression of synaptic and inflammatory changes in stress. Thus, a comparison between IGF-1/IGF-1R/CaMKIIα, synaptic and DAMP proteins in stress and PET may highlight the significance of PET on synaptic morphology and neuronal inflammatory response. In behaviorally characterized Sprague-Dawley rats, there was a significant decline in neural IGF-1 (pIGF-1R expression. These animals showed a significant loss of presynaptic markers (synaptophysin; pIGF-1 (pIGF-1R was recorded in the Stress-PET group (pIGF-1/IGF-1R, an increase in activated hippocampal and cortical microglia was seen in stress (pIGF1/IGF-1R/CaMKIIα. Firstly, we showed a direct relationship between IGF-1/IGF-1R expression, presynaptic function (synaptophysin) and neurotransmitter activity in stress and PET. Secondly, we identified the possible role of CaMKIIα in post-synaptic function and regulation of small ion conductance channels. Lastly, we highlighted some of the possible links between IGF1/IGF-1R/CaMKIIα, the expression of DAMP proteins, Microglia activation, and its implication on synaptic plasticity during stress and PET. Copyright © 2017

Superhydrophobic Copper Surfaces with Anticorrosion Properties Fabricated by Solventless CVD Methods.

Science.gov (United States)

Vilaró, Ignasi; Yagüe, Jose L; Borrós, Salvador

2017-01-11

Due to continuous miniaturization and increasing number of electrical components in electronics, copper interconnections have become critical for the design of 3D integrated circuits. However, corrosion attack on the copper metal can affect the electronic performance of the material. Superhydrophobic coatings are a commonly used strategy to prevent this undesired effect. In this work, a solventless two-steps process was developed to fabricate superhydrophobic copper surfaces using chemical vapor deposition (CVD) methods. The superhydrophobic state was achieved through the design of a hierarchical structure, combining micro-/nanoscale domains. In the first step, O 2 - and Ar-plasma etchings were performed on the copper substrate to generate microroughness. Afterward, a conformal copolymer, 1H,1H,2H,2H-perfluorodecyl acrylate-ethylene glycol diacrylate [p(PFDA-co-EGDA)], was deposited on top of the metal via initiated CVD (iCVD) to lower the surface energy of the surface. The copolymer topography exhibited a very characteristic and unique nanoworm-like structure. The combination of the nanofeatures of the polymer with the microroughness of the copper led to achievement of the superhydrophobic state. AFM, SEM, and XPS were used to characterize the evolution in topography and chemical composition during the CVD processes. The modified copper showed water contact angles as high as 163° and hysteresis as low as 1°. The coating withstood exposure to aggressive media for extended periods of time. Tafel analysis was used to compare the corrosion rates between bare and modified copper. Results indicated that iCVD-coated copper corrodes 3 orders of magnitude slower than untreated copper. The surface modification process yielded repeatable and robust superhydrophobic coatings with remarkable anticorrosion properties.

Genotoxicology: Single and Joint Action of Copper and Zinc to ...

African Journals Online (AJOL)

Michael Horsfall

Synodontis clarias and Tilapia nilotica using the sensitive micronucleus assay in fish genome. ... concentrations are important for the physiological ... Fish were divided into exposure groups for every concentration studied. Fish in twenties were exposed to copper and zinc, forty fish to the mixture of metals, and twenty fish ...

Copper-induced activation of TRP channels promotes extracellular calcium entry and activation of CaMs and CDPKs leading to copper entry and membrane depolarization in Ulva compressa

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Melissa eGómez

2015-03-01

Full Text Available In order to identify channels involved in membrane depolarization, Ulva compressa was incubated with agonists of TRP channels C5, A1 and V1 and the level of intracellular calcium was detected. Agonists of TRPC5, A1 and V1 induced increases in intracellular calcium at 4, 9 and 12 min of exposure, respectively, and antagonists of TRPC5, A1 and V1 corresponding to SKF-96365 (SKF, HC-030031 (HC and capsazepin (CPZ, respectively, inhibited calcium increases indicating that functional TRPs exist in U. compressa. In addition, copper excess induced increases in intracellular calcium at 4, 9 and 12 min which were inhibited by SKF, HC and CPZ, respectively, indicating that copper activate TRPC5, A1 and V1 channels. Moreover, copper-induced calcium increases were inhibited by EGTA, a non-permeable calcium chelating agent, but not by thapsigargin, an inhibitor of endoplasmic reticulum (ER calcium ATPase, indicating that activation of TRPs leads to extracellular calcium entry. Furthermore, copper-induced calcium increases were not inhibited by W-7, an inhibitor of CaMs, and staurosporine, an inhibitor of CDPKs, indicating that extracellular calcium entry did not require CaMs and CDPKs activation. In addition, copper induced membrane depolarization events at 4, 8 and 11 min and these events were inhibited by SKF, HC, CPZ and bathocuproine, a specific copper chelating agent, indicating copper entry through TRP channels leading to membrane depolarization. Moreover, membrane depolarization events were inhibited by W-7 and staurosporine, indicating that CaMs and CDPKs are required in order to activate TRPs to allow copper entry. Thus, light-dependent copper-induced activation TRPC5, A1 and V1 promotes extracellular calcium entry leading to activation of CaMs and CDPKs which, in turn, promotes copper entry through these TRP channels leading to membrane depolarization.

Radiation effects limits on copper in superconducting magnets

International Nuclear Information System (INIS)

Guinan, M.W.

1984-01-01

The determination of the response of copper stabilizers to neutron irradiation in fusion reactor superconducting magnets requires information in four areas. (1) Neutron flux and spectrum determination are a major factor in the accuracy with which stabilizer response can be predicted. Since magnet stability depends on the weakest link, calculations must be made in sufficient detail to fully account for steep flux gradients and local pertubations from penetrations. (2) Resistivity changes at zero field in magnet spectra are generally calculated from the damage energy cross-section or the equivalent displacement (dpa) rate. (3) Resistivity changes at field for conceptual designs are generally determined from the changes predicted at zero field by the use of a Kohler plot. The cyclic irradiation and annealing, expected to be characteristic of fusion reactor magnet operation, is presently the largest source of uncertainty in determining the limits of neutron exposure for copper stabilizers. Applications of our current understanding of the limits of copper stabilizers in fusion reactor designs are explored in two examples. Recommendations for future additions to the data base are discussed

Effects of chronic copper exposure on development and survival in the southern leopard frog (Lithobates [Rana] sphenocephalus).

Science.gov (United States)

Lance, Stacey L; Erickson, Matthew R; Flynn, R Wesley; Mills, Gary L; Tuberville, Tracey D; Scott, David E

2012-07-01

Exposure to environmental contaminants contributes to the global decline of amphibian populations. The impacts of organic contaminants on amphibians are well documented. However, substantially less is known concerning the potential effects of metals on amphibian populations. Copper (Cu) is an essential element, but it can be toxic at concentrations only slightly higher than the normal physiological range. The present study examines the effects of chronic Cu exposure on embryos and larvae of southern leopard frogs, Lithobates (Rana) sphenocephalus. Groups of eggs from multiple clutches were collected from two wetlands and exposed to a range of Cu concentrations (0-150 µg/L) until they reached the free-swimming stage, and then individual larvae were reared to metamorphosis. Higher Cu concentrations significantly reduced embryo survival to the free-swimming stage but did not further reduce survival to metamorphosis. Larval period was affected by Cu treatment, but the clutch from which larvae originated (i.e., parentage) explained a higher proportion of the variation. Embryo survival to hatching varied significantly among clutches, ranging from 42.9 to 79.2%. Measurable levels of Cu were found in larvae with body burdens up to 595 µg Cu/g dry mass in the 100 µg/L treatment, and larval Cu body burdens were higher than in metamorphs. The present study also demonstrated that higher initial egg density ameliorated embryo mortality at higher Cu levels and should be accounted for in future studies. Copyright © 2012 SETAC.

Reagent conditions of the flotation of copper, copper - molybdenum and copper -zinc ores in foreing countries

International Nuclear Information System (INIS)

Nevaeva, L.M.

1983-01-01

Reagents-collectors and frothers, used abroad in reagent regimes of flotation of copper, copper-molybdenum and copper zinc ores, have been considered. Xanthogenates, aerofloats, xanthogenformiates, thionocarbamates are mainly used as reagents-collectors. Methylizobutylcarbinol and Daufros are used as reagents-frothers

Post-test examination of a copper electrode from deposition hole 5 in the Prototype Repository

International Nuclear Information System (INIS)

Rosborg, Bo

2013-04-01

can have a marked influence on the corrosion behaviour between the exposed small samples and the big components exist. The most convincing is that lubricants were used in manufacturing of the full-size bentonite blocks and rings (so available machines could handle the required pressure); lubricants have neither been used for the copper electrodes in the Prototype Repository, nor for the copper coupons in the LOT test parcels. Based upon the performed corrosion potential measurements and the findings from the post-test examination the following scenario of exposure is envisaged: When installed the copper electrode had merely a very thin cuprite film on the surface from exposure in air. After some length of exposure a corrosion potential was reached that allowed formation of Cu(II) corrosion products. Since the chloride activity in the pore water from start of exposure was low (the bentonite had been conditioned with tap water), malachite rather than paratacamite was formed. Later on the corrosion potential has decreased, influenced by changes in the near-field environment and filming of the surface, and obtained a corrosion potential of -40 mV SHE at the time when part of the concrete plug to the outer section had been removed, which indicates a mildly oxidizing environment. Thus, it is anticipated that the copper electrode has been exposed to oxic conditions all through the exposure period

Post-test examination of a copper electrode from deposition hole 5 in the Prototype Repository

Energy Technology Data Exchange (ETDEWEB)

Rosborg, Bo [Rosborg Consulting, Nykoeping (Sweden)

2013-04-15

bentonite. Differences that can have a marked influence on the corrosion behaviour between the exposed small samples and the big components exist. The most convincing is that lubricants were used in manufacturing of the full-size bentonite blocks and rings (so available machines could handle the required pressure); lubricants have neither been used for the copper electrodes in the Prototype Repository, nor for the copper coupons in the LOT test parcels. Based upon the performed corrosion potential measurements and the findings from the post-test examination the following scenario of exposure is envisaged: When installed the copper electrode had merely a very thin cuprite film on the surface from exposure in air. After some length of exposure a corrosion potential was reached that allowed formation of Cu(II) corrosion products. Since the chloride activity in the pore water from start of exposure was low (the bentonite had been conditioned with tap water), malachite rather than paratacamite was formed. Later on the corrosion potential has decreased, influenced by changes in the near-field environment and filming of the surface, and obtained a corrosion potential of -40 mV SHE at the time when part of the concrete plug to the outer section had been removed, which indicates a mildly oxidizing environment. Thus, it is anticipated that the copper electrode has been exposed to oxic conditions all through the exposure period.

Sampling in schools and large institutional buildings: Implications for regulations, exposure and management of lead and copper.

Science.gov (United States)

Doré, Evelyne; Deshommes, Elise; Andrews, Robert C; Nour, Shokoufeh; Prévost, Michèle

2018-04-21

Legacy lead and copper components are ubiquitous in plumbing of large buildings including schools that serve children most vulnerable to lead exposure. Lead and copper samples must be collected after varying stagnation times and interpreted in reference to different thresholds. A total of 130 outlets (fountains, bathroom and kitchen taps) were sampled for dissolved and particulate lead as well as copper. Sampling was conducted at 8 schools and 3 institutional (non-residential) buildings served by municipal water of varying corrosivity, with and without corrosion control (CC), and without a lead service line. Samples included first draw following overnight stagnation (>8h), partial (30 s) and fully (5 min) flushed, and first draw after 30 min of stagnation. Total lead concentrations in first draw samples after overnight stagnation varied widely from 0.07 to 19.9 μg Pb/L (median: 1.7 μg Pb/L) for large buildings served with non-corrosive water. Higher concentrations were observed in schools with corrosive water without CC (0.9-201 μg Pb/L, median: 14.3 μg Pb/L), while levels in schools with CC ranged from 0.2 to 45.1 μg Pb/L (median: 2.1 μg Pb/L). Partial flushing (30 s) and full flushing (5 min) reduced concentrations by 88% and 92% respectively for corrosive waters without CC. Lead concentrations were 45% than values in 1st draw samples collected after overnight stagnation. Concentrations of particulate Pb varied widely (≥0.02-846 μg Pb/L) and was found to be the cause of very high total Pb concentrations in the 2% of samples exceeding 50 μg Pb/L. Pb levels across outlets within the same building varied widely (up to 1000X) especially in corrosive water (0.85-851 μg Pb/L after 30MS) confirming the need to sample at each outlet to identify high risk taps. Based on the much higher concentrations observed in first draw samples, even after a short stagnation, the first 250mL should be discarded unless no sources

Reconnaissance and economic geology of Copper Mountain metamorphic complex, Owl Creek Mountains, Wyoming

International Nuclear Information System (INIS)

Hausel, W.D.

1983-01-01

The Copper Mountain metamorphic complex lies within a westerly trending belt of Precambrian exposures known as the Owl Creek Mountains uplift. The metamorphic complex at Copper Mountain is part of a larger complex known as the Owl Creek Mountains greenstone belt. Until more detailed mapping and petrographic studies can be completed, the Copper Mountain area is best referred to as a complex, even though it has some characteristics of a greestone belt. At least three episodes of Precambrian deformation have affected the supracrustals, and two have disturbed the granites. The final Precambrian deformation event was preceded by a weak thermal event expressed by retrogressive metamorphism and restricted metasomatic alteration. During this event, a second phase of pegmatization was accompanied by hydrothermal solutions. During the Laramide orogeny, Copper Mountain was again modified by deformation. Laramide deformation produced complex gravity faults and keystone grabens. Uranium deposits were formed following major Laramide deformation. The genesis of these deposits is attributable to either the leaching of granites or the leaching of overlying tuffaceous sediments during the Tertiary. Production of metals and industrial minerals has been limited, although some gold, copper, silver, tungsten, beryl, feldspar, and lithium ore have been shipped from Copper Mountain. A large amount of uranium was produced from the Copper Mountain district in the 1950s

Copper Contamination Impairs Herbivore Initiation of Seaweed Inducible Defenses and Decreases Their Effectiveness.

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Alexandria M Warneke

Full Text Available Seaweed-herbivore interactions are often mediated by environmental conditions, yet the roles of emerging anthropogenic stressors on these interactions are poorly understood. For example, chemical contaminants have unknown consequences on seaweed inducible resistance and herbivore response to these defenses despite known deleterious effects of contaminants on animal inducible defenses. Here, we investigated the effect of copper contamination on the interactions between a snail herbivore and a brown seaweed that displays inducible resistance to grazing. We examined seaweed inducible resistance and its effectiveness for organisms exposed to copper at two time points, either during induction or after herbivores had already induced seaweed defenses. Under ambient conditions, non-grazed tissues were more palatable than grazed tissues. However, copper additions negated the preference for non-grazed tissues regardless of the timing of copper exposure, suggesting that copper decreased both how herbivores initiated these inducible defenses and their subsequent effectiveness. Copper decreased stimulation of defenses, at least in part, by suppressing snail grazing pressure-the cue that turns inducible defenses on. Copper decreased effectiveness of defenses by preventing snails from preferentially consuming non-grazed seaweed. Thus, contaminants can potentially stress communities by changing seaweed-herbivore interactions mediated via inducible defenses. Given the ubiquity of seaweed inducible resistance and their potential influence on herbivores, we hypothesize that copper contamination may change the impact of these resistant traits on herbivores.

Composition of Whiskers Grown on Copper in Repository Environment

International Nuclear Information System (INIS)

Hermansson, Hans-Peter; Tarkpea, Peeter; Holgersson, Stellan

2001-11-01

There is a hypothesis that a special family of local attack on copper based on growth of whiskers of sulfide, oxide/hydroxide and also carbonate/malachite could appear in the repository environment. It was earlier demonstrated that such whiskers could grow in a laboratory simulated repository environment, containing sulfide. A suggested composition of whiskers has earlier been forwarded but was not demonstrated. In the present work whiskers and their substrates were grown and characterized by investigations with a combination of SEM-EDS, XRD and LRS (Laser Raman Spectroscopy) techniques. SEM-EDS was used to determine the morphology and an elemental composition and distribution of whiskers and their substrate. A special effort was made to find out if the whisker growth is of a local or global character. The phase status could be determined locally and globally by combining XRD and LRS techniques on whiskers and substrates. Ideally, LRS gives a phase resolution down to a radius of 1 μm on the sample surface. This is of great value as it is of interest to study if there are phase differences in different parts of a whisker. Such information is important to understand the whisker growth mechanism. Cylindrical samples of pure copper were prepared and exposed to the selected de-aerated model groundwater containing, among other ions, chloride and sulfide. Exposure was performed in sealed glass flasks under de-aerated conditions. After exposure the copper sample was investigated on the surface, in cross section and on whiskers using the mentioned techniques. The results show that a black, easily detached layer of corrosion products is formed on the sample surface. The corrosion layer was subdivided into at least five parallel strata (probably more) of different composition. Numerous small pits and shallow pitting attacks with a larger radius were observed in the copper metal and the metal surface was in general very rough. A multitude of very easily detached whiskers or

Hypoxic ventilatory sensitivity in men is not reduced by prolonged hyperoxia (Predictive Studies V and VI)

Science.gov (United States)

Gelfand, R.; Lambertsen, C. J.; Clark, J. M.; Hopkin, E.

1998-01-01

Potential adverse effects on the O2-sensing function of the carotid body when its cells are exposed to toxic O2 pressures were assessed during investigations of human organ tolerance to prolonged continuous and intermittent hyperoxia (Predictive Studies V and VI). Isocapnic hypoxic ventilatory responses (HVR) were determined at 1.0 ATA before and after severe hyperoxic exposures: 1) continuous O2 breathing at 1.5, 2.0, and 2.5 ATA for 17.7, 9.0, and 5.7 h and 2) intermittent O2 breathing at 2.0 ATA (30 min O2-30 min normoxia) for 14.3 O2 h within 30-h total time. Postexposure curvature of HVR hyperbolas was not reduced compared with preexposure controls. The hyperbolas were temporarily elevated to higher ventilations than controls due to increments in respiratory frequency that were proportional to O2 exposure time, not O2 pressure. In humans, prolonged hyperoxia does not attenuate the hypoxia-sensing function of the peripheral chemoreceptors, even after exposures that approach limits of human pulmonary and central nervous system O2 tolerance. Current applications of hyperoxia in hyperbaric O2 therapy and in subsea- and aerospace-related operations are guided by and are well within these exposure limits.

Improving Beneficiation of Copper and Iron from Copper Slag by Modifying the Molten Copper Slag

Directory of Open Access Journals (Sweden)

Zhengqi Guo

2016-04-01

Full Text Available In the paper, a new technology was developed to improve the beneficiation of copper and iron components from copper slag, by modifying the molten slag to promote the mineralization of valuable minerals and to induce the growth of mineral grains. Various parameters, including binary basicity, dosage of compound additive, modification temperature, cooling rate and the end point temperature of slow cooling were investigated. Meanwhile, optical microscope, scanning electron microscope and energy dispersive spectrometer (SEM-EDS was employed to determine the mineralogy of the modified and unmodified slag, as well as to reveal the mechanisms of enhancing beneficiation. The results show that under the proper conditions, the copper grade of rougher copper concentrate was increased from 6.43% to 11.04%, iron recovery of magnetic separation was increased significantly from 32.40% to 63.26%, and other evaluation indexes were changed slightly, in comparison with unmodified copper slag. Moreover, matte and magnetite grains in the modified slag aggregated together and grew obviously to the mean size of over 50 μm, resulting in an improvement of beneficiation of copper and iron.

Copper influence on bank vole's (Myodes glareolus) sexual behavior.

Science.gov (United States)

Miska-Schramm, Agata; Kapusta, Joanna; Kruczek, Małgorzata

2018-04-01

The impact of human activity on the environment has led to a steady increase of the amounts of copper in the ecosystems. This element accumulates in plants and water, potentially exposing rodents to its harmful effects. In industrial districts, a decrease in the density of small rodent populations has been observed. This decline may be caused by many factors, including mortality, decreased fertility, or impaired sexual behavior. The decline in the reproductive abilities of small rodents after copper exposure was demonstrated in our previous work (Miska-Schramm A, Kruczek M, Kapusta J, Ecotoxicology 23:1546-1554, 2014). The aim of the presented research was to determine how copper administered at concentrations similar to those recorded in industrial districts (Cu I-150 mg/kg, Cu II-600 mg/kg, C-control) affects the sexual behavior of small rodents. The model species was the bank vole (Myodes glareolus). The behavior and vocalizations of male-female pairs were recorded during open-field tests: ♂C vs. ♀C; ♂Cu I vs. ♀C; ♂Cu II vs. ♀C while in preference tests, female behavior was assessed in the following combinations: ♀C vs. ♂C & ♂Cu I; ♀C vs. ♂C & ♂Cu II. In the presented work, we show that copper decreased the males' sexual attractiveness. Females showed suppressed preference towards males treated with 600 mg/kg copper. The number of sniffs and a number of approaches towards Cu II males was significantly lower than towards control individuals. Also, in preference test with 150 mg/kg treated animals, total activity was lower towards copper treated animals. At the same time, copper did not influence intra-sexual interactions.

21 CFR 73.1125 - Potassium sodium copper chloropyhllin (chlorophyllin-copper complex).

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Potassium sodium copper chloropyhllin (chlorophyllin-copper complex). 73.1125 Section 73.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT....1125 Potassium sodium copper chloropyhllin (chlorophyllin-copper complex). (a) Identity. (1) The color...

21 CFR 73.2125 - Potassium sodium copper chlorophyllin (chlorophyllin-copper complex).

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). 73.2125 Section 73.2125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... § 73.2125 Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). (a) Identity and...

Carbon Nanotube Fiber Pretreatments for Electrodeposition of Copper

OpenAIRE

Hannula, Pyry-Mikko; Junnila, Minttu; Janas, Dawid; Aromaa, Jari; Forsén, Olof; Lundström, Mari

2018-01-01

There is increasing interest towards developing carbon nanotube-copper (CNT-Cu) composites due to potentially improved properties. Carbon nanotube macroscopic materials typically exhibit high resistivity, low electrochemical reactivity, and the presence of impurities, which impede its use as a substrate for electrochemical deposition of metals. In this research, different CNT fiber pretreatment methods, such as heat treatment, immersion in Watts bath, anodization, and exposure to boric acid (...

Comparison between micro- and nanosized copper oxide and water soluble copper chloride: interrelationship between intracellular copper concentrations, oxidative stress and DNA damage response in human lung cells.

Science.gov (United States)

Strauch, Bettina Maria; Niemand, Rebecca Katharina; Winkelbeiner, Nicola Lisa; Hartwig, Andrea

2017-08-01

Nano- and microscale copper oxide particles (CuO NP, CuO MP) are applied for manifold purposes, enhancing exposure and thus the potential risk of adverse health effects. Based on the pronounced in vitro cytotoxicity of CuO NP, systematic investigations on the mode of action are required. Therefore, the impact of CuO NP, CuO MP and CuCl 2 on the DNA damage response on transcriptional level was investigated by quantitative gene expression profiling via high-throughput RT-qPCR. Cytotoxicity, copper uptake and the impact on the oxidative stress response, cell cycle regulation and apoptosis were further analysed on the functional level. Cytotoxicity of CuO NP was more pronounced when compared to CuO MP and CuCl 2 in human bronchial epithelial BEAS-2B cells. Uptake studies revealed an intracellular copper overload in the soluble fractions of both cytoplasm and nucleus, reaching up to millimolar concentrations in case of CuO NP and considerably lower levels in case of CuO MP and CuCl 2 . Moreover, CuCl 2 caused copper accumulation in the nucleus only at cytotoxic concentrations. Gene expression analysis in BEAS-2B and A549 cells revealed a strong induction of uptake-related metallothionein genes, oxidative stress-sensitive and pro-inflammatory genes, anti-oxidative defense-associated genes as well as those coding for the cell cycle inhibitor p21 and the pro-apoptotic Noxa and DR5. While DNA damage inducible genes were activated, genes coding for distinct DNA repair factors were down-regulated. Modulation of gene expression was most pronounced in case of CuO NP as compared to CuO MP and CuCl 2 and more distinct in BEAS-2B cells. GSH depletion and activation of Nrf2 in HeLa S3 cells confirmed oxidative stress induction, mainly restricted to CuO NP. Also, cell cycle arrest and apoptosis induction were most distinct for CuO NP. The high cytotoxicity and marked impact on gene expression by CuO NP can be ascribed to the strong intracellular copper ion release, with subsequent

Effects of Prolonged Silver Nanoparticle Exposure on the Contextual Cognition and Behavior of Mammals

Directory of Open Access Journals (Sweden)

Anna Antsiferova

2018-04-01

Full Text Available Silver nanoparticles have been widely used in the lighting and food industries, in medicine, and in pharmaceutics as an antiseptic agent. Recent research demonstrates that, after prolonged oral administration, silver nanoparticles may cross the blood-brain barrier and accumulate in the brain in rather high amounts. In ex vivo experiments, it has also been shown that silver nanoparticles demonstrate neurotoxicity. The objective of this work was to answer the questions whether silver nanoparticles change cognitive and behavioral functions of mammals after prolonged administration if silver nanoparticles have accumulated in the brain. C57Bl/6 male mice were orally exposed to PVP-coated silver nanoparticles daily for 30, 60, 120 and 180 days. Control mice were exposed to distilled water. After that they were tested in the Open Field, Elevated Plus Maze, Light-Dark Box and contextual fear conditioning task. The data have shown that the experimental mice went through three periods of switching in the behavior caused by adaptation to the toxic silver nanoparticles: anxiety, appearance of research instinct and impairment of long-term memory. This provides evidence of the hazardous effect of silver nanoparticles, which appears after long periods of silver nanoparticle oral administration.

Contrasting effects of hypoxia on copper toxicity during development in the three-spined stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Fitzgerald, Jennifer A; Katsiadaki, Ioanna; Santos, Eduarda M

2017-03-01

Hypoxia is a global problem in aquatic systems and often co-occurs with pollutants. Despite this, little is known about the combined effects of these stressors on aquatic organisms. The objective of this study was to investigate the combined effects of hypoxia and copper, a toxic metal widespread in the aquatic environment. We used the three-spined stickleback (Gasterosteus aculeatus) as a model because of its environmental relevance and amenability for environmental toxicology studies. We focused on embryonic development as this is considered to be a sensitive life stage to environmental pollution. We first investigated the effects of hypoxia alone on stickleback development to generate the information required to design subsequent studies. Our data showed that exposure to low oxygen concentrations (24.7 ± 0.9% air saturation; AS) resulted in strong developmental delays and increased mortalities, whereas a small decrease in oxygen (75.0 ± 0.5%AS) resulted in premature hatching. Stickleback embryos were then exposed to a range of copper concentrations under hypoxia (56.1 ± 0.2%AS) or normoxia (97.6 ± 0.1%AS), continuously, from fertilisation to free swimming larvae. Hypoxia caused significant changes in copper toxicity throughout embryonic development. Prior to hatching, hypoxia suppressed the occurrence of mortalities, but after hatching hypoxia significantly increased copper toxicity. Interestingly, when exposures were conducted only after hatching, the onset of copper-induced mortalities was delayed under hypoxia compared to normoxia, but after 48 h, copper was more toxic to hatched embryos under hypoxia. This is the second species for which the protective effect of hypoxia on copper toxicity prior to hatching, followed by its exacerbating effect after hatching is demonstrated, suggesting the hypothesis that this pattern may be common for teleost species. Our research highlights the importance of considering the interactions between multiple

Low levels of copper reduce the reproductive success of a mobile invertebrate predator.

Science.gov (United States)

Lee, Ka-Man; Johnston, Emma L

2007-09-01

Marine organisms that occur in urbanised bays can be exposed to low-level chronic pollution that results in sublethal changes to behavior or reproduction. The effects of low levels of copper on the reproductive success of a mobile invertebrate were assessed. Free living flatworms are common predators of bivalves and barnacles. Flatworms (Stylochus pygmaeus) were exposed to low levels of copper ranging from 0 to 25 microg L(-1) in the presence and absence of their barnacle prey (Balanus variegatus). Flatworms laid fewer egg batches when exposed to copper and the hatching success of the eggs was also reduced. Exposure to 25 microg L(-1) copper for 10 d reduced the reproductive success of flatworms by up to 80%. Results were consistent regardless of the presence or absence of prey (barnacles). Barnacles were only moderately affected by copper but exhibited major avoidance behavior (feeding inhibition) in the presence of flatworm predators. This is the first ecotoxicological study on marine flatworms. Experiments are required to quantify the effects of flatworm predator populations on sessile invertebrate community structure in the field.

Chemical-specific health consultation for chromated copper arsenate chemical mixture: port of Djibouti.

Science.gov (United States)

Chou, Selene; Colman, Joan; Tylenda, Carolyn; De Rosa, Christopher

2007-05-01

The Agency for Toxic Substances and Disease Registry (ATSDR) prepared this health consultation to provide support for assessing the public health implications of hazardous chemical exposure, primarily through drinking water, related to releases of chromated copper arsenate (CCA) in the port of Djibouti. CCA from a shipment, apparently intended for treating electric poles, is leaking into the soil in the port area. CCA is a pesticide used to protect wood against decay-causing organisms. This mixture commonly contains chromium(VI) (hexavalent chromium) as chromic acid, arsenic(V) (pentavalent arsenic) as arsenic pentoxide and copper (II) (divalent copper) as cupric oxide, often in an aqueous solution or concentrate. Experimental studies of the fate of CCA in soil and monitoring studies of wood-preserving sites where CCA was spilled on the soil indicate that the chromium(VI), arsenic and copper components of CCA can leach from soil into groundwater and surface water. In addition, at CCA wood-preserving sites, substantial concentrations of chromium(VI), arsenic and copper remained in the soil and were leachable into water four years after the use of CCA was discontinued, suggesting prolonged persistence in soil, with continued potential for leaching. The degree of leaching depended on soil composition and the extent of soil contamination with CCA. In general, leaching was highest for chromium(VI), intermediate for arsenic and lowest for copper. Thus, the potential for contamination of sources of drinking water exists. Although arsenic that is leached from CCA-contaminated soil into surface water may accumulate in the tissues of fish and shellfish, most of the arsenic in these animals will be in a form (often called fish arsenic) that is less harmful. Copper, which leaches less readily than the other components, can accumulate in tissues of mussels and oysters. Chromium is not likely to accumulate in the tissues of fish and shellfish. Limited studies of air

Nickel, copper and cobalt coalescence in copper cliff converter slag

Directory of Open Access Journals (Sweden)

Wolf A.

2016-01-01

Full Text Available The aim of this investigation is to assess the effect of various additives on coalescence of nickel, copper and cobalt from slags generated during nickel extraction. The analyzed fluxes were silica and lime while examined reductants were pig iron, ferrosilicon and copper-silicon compound. Slag was settled at the different holding temperatures for various times in conditions that simulated the industrial environment. The newly formed matte and slag were characterized by their chemical composition and morphology. Silica flux generated higher partition coefficients for nickel and copper than the addition of lime. Additives used as reducing agents had higher valuable metal recovery rates and corresponding partition coefficients than fluxes. Microstructural studies showed that slag formed after adding reductants consisted of primarily fayalite, with some minute traces of magnetite as the secondary phase. Addition of 5 wt% of pig iron, ferrosilicon and copper-silicon alloys favored the formation of a metallized matte which increased Cu, Ni and Co recoveries. Addition of copper-silicon alloys with low silicon content was efficient in copper recovery but coalescence of the other metals was low. Slag treated with the ferrosilicon facilitated the highest cobalt recovery while copper-silicon alloys with silicon content above 10 wt% resulted in high coalescence of nickel and copper, 87 % and 72 % respectively.

Modeling U-Shaped Exposure-Response Relationships for Agents that Demonstrate Toxicity Due to Both Excess and Deficiency.

Science.gov (United States)

Milton, Brittany; Farrell, Patrick J; Birkett, Nicholas; Krewski, Daniel

2017-02-01

Essential elements such as copper and manganese may demonstrate U-shaped exposure-response relationships due to toxic responses occurring as a result of both excess and deficiency. Previous work on a copper toxicity database employed CatReg, a software program for categorical regression developed by the U.S. Environmental Protection Agency, to model copper excess and deficiency exposure-response relationships separately. This analysis involved the use of a severity scoring system to place diverse toxic responses on a common severity scale, thereby allowing their inclusion in the same CatReg model. In this article, we present methods for simultaneously fitting excess and deficiency data in the form of a single U-shaped exposure-response curve, the minimum of which occurs at the exposure level that minimizes the probability of an adverse outcome due to either excess or deficiency (or both). We also present a closed-form expression for the point at which the exposure-response curves for excess and deficiency cross, corresponding to the exposure level at which the risk of an adverse outcome due to excess is equal to that for deficiency. The application of these methods is illustrated using the same copper toxicity database noted above. The use of these methods permits the analysis of all available exposure-response data from multiple studies expressing multiple endpoints due to both excess and deficiency. The exposure level corresponding to the minimum of this U-shaped curve, and the confidence limits around this exposure level, may be useful in establishing an acceptable range of exposures that minimize the overall risk associated with the agent of interest. © 2016 Society for Risk Analysis.

Antwerp Copper Plates

DEFF Research Database (Denmark)

Wadum, Jørgen

1999-01-01

In addition to presenting a short history of copper paintings, topics detail artists’ materials and techniques, as well as aspects of the copper industry, including mining, preparation and trade routes.......In addition to presenting a short history of copper paintings, topics detail artists’ materials and techniques, as well as aspects of the copper industry, including mining, preparation and trade routes....

Supplementing exposure to hypoxia with a copper depleted diet does not exacerbate right ventricular remodeling in mice.

Directory of Open Access Journals (Sweden)

Ella M Poels

Full Text Available Pulmonary hypertension and subsequent right ventricular (RV failure are associated with high morbidity and mortality. Prognosis is determined by occurrence of RV failure. Currently, adequate treatment for RV failure is lacking. Further research into the molecular basis for the development of RV failure as well as the development of better murine models of RV failure are therefore imperative. We hypothesize that adding a low-copper diet to chronic hypoxia in mice reinforces their individual effect and that the combination of mild pulmonary vascular remodeling and capillary rarefaction, induces RV failure.Six week old mice were subjected to normoxia (N; 21% O2 or hypoxia (H; 10% O2 during a period of 8 weeks and received either a normal diet (Cu+ or a copper depleted diet (Cu-. Cardiac function was assessed by echocardiography and MRI analysis.Here, we characterized a mouse model of chronic hypoxia combined with a copper depleted diet and demonstrate that eight weeks of chronic hypoxia (10% is sufficient to induce RV hypertrophy and subsequent RV failure. Addition of a low copper diet to hypoxia did not have any further deleterious effects on right ventricular remodeling.

Paternal work stress and prolonged time to pregnancy.

Science.gov (United States)

Lee, Mi-Sun; Paek, Domyung; Eum, Ki-Do; Siegrist, Johannes; Li, Jian; Lee, Hye-Eun; Cho, Sung-Il

2009-01-01

The aim of this study was to explore an association between psychosocial stress at work in married men and their spouses' prolonged time to pregnancy (TTP). All married male workers of a large Korean petrochemical enterprise and their wives fulfilling the selection criteria were included. Main selection criteria were lack of use of contraceptives and experienced pregnancy in recent past. Data were available from 322 couples. Psychosocial stress at work was measured by the effort-reward imbalance questionnaire. Prolonged TTP was measured by the "TTP questionnaire". After adjustment for confounding effects of demographic and life-style characteristics and benzene exposure, delayed TTP, defined by frequency of first-cycle pregnancy, was associated with one standard deviation (SD) increase of the effort-reward ratio in the chronically stressed group of married men (OR = 0.47; 95% CI = 0.22-0.99) in logistic regression analysis. A similar, but somewhat weaker effect, was found for the overall group (OR = 0.67; 95% CI = 0.47-0.94). Paternal stress at work, as measured by effort-reward imbalance, seemed to be associated with a decreased number of conceptions in the first menstrual cycle.

A Comparison of Cognitive-Processing Therapy With Prolonged Exposure and a Waiting Condition for the Treatment of Chronic Posttraumatic Stress Disorder in Female Rape Victims

Science.gov (United States)

Resick, Patricia A.; Nishith, Pallavi; Weaver, Terri L.; Astin, Millie C.; Feuer, Catherine A.

2010-01-01

The purpose of this study was to compare cognitive-processing therapy (CPT) with prolonged exposure and a minimal attention condition (MA) for the treatment of posttraumatic stress disorder (PTSD) and depression. One hundred seventy-one female rape victims were randomized into 1 of the 3 conditions, and 121 completed treatment. Participants were assessed with the Clinician-Administered PTSD Scale, the PTSD Symptom Scale, the Structured Clinical Interview for DSM–IV, the Beck Depression Inventory, and the Trauma-Related Guilt Inventory. Independent assessments were made at pretreatment, posttreatment, and 3 and 9 months posttreatment. Analyses indicated that both treatments were highly efficacious and superior to MA. The 2 therapies had similar results except that CPT produced better scores on 2 of 4 guilt subscales. PMID:12182270

A novel zebrafish mutant with wavy-notochord: an effective biological index for monitoring the copper pollution of water from natural resources.

Science.gov (United States)

Chen, Yau-Hung; Lin, Ji-Sheng

2011-02-01

We identified a novel zebrafish mutant that has wavy-notochord phenotypes, such as severely twisted notochord and posterior malformations, but has normal melanocytes. Histological evidences showed that proliferating vacuolar cells extended their growth to the muscle region, and consequently caused the wavy-notochord phenotypes. Interestingly, those malformations can be greatly reversed by exposure with copper, suggesting that copper plays an important role on wavy-notochord phenotypes. In addition, after long-term copper exposure, the surviving larvae derived from wavy-notochord mutants displayed bone malformations, such as twisted axial skeleton and osteophyte. These phenotypic changes and molecular evidences of wavy-notochord mutants are highly similar to those embryos whose lysyl oxidases activities have been inactivated. Taken together, we propose that (i) the putative mutated genes of this wavy-notochord mutant might be highly associated with the lysyl oxidase genes in zebrafish; and (ii) this fish model is an effective tool for monitoring copper pollution of water from natural resources. Copyright © 2009 Wiley Periodicals, Inc.

The enzymatic and antioxidative stress response of Lemna minor to copper and a chloroacetamide herbicide.

Science.gov (United States)

Obermeier, Michael; Schröder, Christian A; Helmreich, Brigitte; Schröder, Peter

2015-12-01

Lemna minor L., a widely used model plant for toxicity tests has raised interest for its application to phytoremediation due to its rapid growth and ubiquitous occurrence. In rural areas, the pollution of water bodies with heavy metals and agrochemicals poses a problem to surface water quality. Among problematic compounds, heavy metals (copper) and pesticides are frequently found in water bodies. To establish duckweed as a potential plant for phytoremediation, enzymatic and antioxidative stress responses of Lemna minor during exposure to copper and a chloroacetamide herbicide were investigated in laboratory studies. The present study aimed at evaluating growth and the antioxidative and glutathione-dependent enzyme activity of Lemna plants and its performance in a scenario for phytoremediation of copper and a chloroacetamide herbicide. Lemna minor was grown in Steinberg medium under controlled conditions. Plants were treated with CuSO4 (ion conc. 50 and 100 μg/L) and pethoxamide (1.25 and 2.5 μg/L). Measurements following published methods focused on plant growth, oxidative stress, and basic detoxification enzymes. Duckweed proved to survive treatment with the respective concentrations of both pollutants very well. Its growth was inhibited scarcely, and no visible symptoms occurred. On the cellular basis, accumulation of O2(-) and H2O2 were detected, as well as stress reactions of antioxidative enzymes. Duckweed detoxification potential for organic pollutants was high and increased significantly with incubation. Pethoxamide was found to be conjugated with glutathione. Copper was accumulated in the fronds at high levels, and transient oxidative defense reactions were triggered. This work confirms the significance of L. minor for the removal of copper from water and the conjugation of the selective herbicide pethoxamide. Both organic and inorganic xenobiotics induced different trends of enzymatic and antioxidative stress response. The strong increase of stress

Translating QT interval prolongation from conscious dogs to humans.

Science.gov (United States)

Dubois, Vincent F S; Smania, Giovanni; Yu, Huixin; Graf, Ramona; Chain, Anne S Y; Danhof, Meindert; Della Pasqua, Oscar

2017-02-01

In spite of screening procedures in early drug development, uncertainty remains about the propensity of new chemical entities (NCEs) to prolong the QT/QTc interval. The evaluation of proarrhythmic activity using a comprehensive in vitro proarrhythmia assay does not fully account for pharmacokinetic-pharmacodynamic (PKPD) differences in vivo. In the present study, we evaluated the correlation between drug-specific parameters describing QT interval prolongation in dogs and in humans. Using estimates of the drug-specific parameter, data on the slopes of the PKPD relationships of nine compounds with varying QT-prolonging effects (cisapride, sotalol, moxifloxacin, carabersat, GSK945237, SB237376 and GSK618334, and two anonymized NCEs) were analysed. Mean slope estimates varied between -0.98 ms μM -1 and 6.1 ms μM -1 in dogs and -10 ms μM -1 and 90 ms μM -1 in humans, indicating a wide range of effects on the QT interval. Linear regression techniques were then applied to characterize the correlation between the parameter estimates across species. For compounds without a mixed ion channel block, a correlation was observed between the drug-specific parameter in dogs and humans (y = -1.709 + 11.6x; R 2  = 0.989). These results show that per unit concentration, the drug effect on the QT interval in humans is 11.6-fold larger than in dogs. Together with information about the expected therapeutic exposure, the evidence of a correlation between the compound-specific parameter in dogs and in humans represents an opportunity for translating preclinical safety data before progression into the clinic. Whereas further investigation is required to establish the generalizability of our findings, this approach can be used with clinical trial simulations to predict the probability of QT prolongation in humans. © 2016 The British Pharmacological Society.

Speciation and leachability of copper in mine tailings from porphyry copper mining

DEFF Research Database (Denmark)

Hansen, Henrik K.; Yianatos, Juan B; Ottosen, Lisbeth M.

2005-01-01

Mine tailing from the El Teniente-Codelco copper mine situated in VI Region of Chile was analysed in order to evaluate the mobility and speciation of copper in the solid material. Mine tailing was sampled after the rougher flotation circuits, and the copper content was measured to 1150mgkg^-^1 dry...... matter. This tailing was segmented into fractions of different size intervals: 0-38, 38-45, 45-53, 53-75, 75-106, 106-150, 150-212, and >212@mm, respectively. Copper content determination, sequential chemical extraction, and desorption experiments were carried out for each size interval in order...... to evaluate the speciation of copper. It was found that the particles of smallest size contained 50-60% weak acid leachable copper, whereas only 32% of the copper found in largest particles could be leached in weak acid. Copper oxides and carbonates were the dominating species in the smaller particles...

Tribological properties of copper-based composites with copper coated NbSe2 and CNT

International Nuclear Information System (INIS)

Chen, Beibei; Yang, Jin; Zhang, Qing; Huang, Hong; Li, Hongping; Tang, Hua; Li, Changsheng

2015-01-01

Graphical abstract: Morphology of copper coated NbSe 2 and CNT; friction coefficient and wear rate of copper-based composites. - Highlights: • NbSe 2 and CNT were coated with copper layers by the means of electroless plating. • The mechanical and tribological properties of copper composites were studied. • The enhancement mechanisms of copper coated NbSe 2 and CNT were proposed. • Copper–copper coated (12 wt.%NbSe 2 –3 wt.%CNT) composite had the best wear resistance. - Abstract: Copper-based composites with copper coated NbSe 2 and/or CNT were fabricated by the powder metallurgy technique. The morphology and phase composition of copper coated NbSe 2 and carbon nanotube (CNT) were observed using high solution transmission electronic microscope (HRTEM), scanning electronic microscope (SEM equipped with EDS) and X-ray diffraction (XRD). The density, hardness, and bending strength of as-prepared copper-based composites were measured, and their tribological properties were investigated using UMT-2 tester. Results indicated that all copper-based composites showed decreased density and bending strength, but increased hardness in comparison with copper matrix. Besides, the incorporation of copper coated NbSe 2 improved the friction-reducing and anti-wear properties of copper matrix. Addition of copper coated CNT greatly enhanced the mechanical and tribological properties. In particular, when the content of copper coated CNT was 3 wt.%, the corresponding composite exhibited the best tribological properties. This was because NbSe 2 was distributed chaotically in matrix, which greatly improved the friction-reducing property of copper, while CNT with superior mechanical strength enhanced the wear resistance by increasing the load-carrying capacity. More importantly, copper layers coated on NbSe 2 and CNT favored the good interfacial combination between fillers and copper matrix showing beneficial effect for the stresses transferring from matrix to fillers

Copper regulation and homeostasis of Daphnia magna and Pseudokirchneriella subcapitata: influence of acclimation

International Nuclear Information System (INIS)

Bossuyt, Bart T.A.; Janssen, Colin R.

2005-01-01

This study aimed to evaluate (1) the capacity of the green alga Pseudokirchneriella subcapitata and the waterflea Daphnia magna to regulate copper when exposed to environmentally realistic copper concentrations and (2) the influence of multi-generation acclimation to these copper concentrations on copper bioaccumulation and homeostasis. Based on bioconcentration factors, active copper regulation was observed in algae up to 5 μg Cu L -1 and in daphnids up to 35 μg Cu L -1 . Constant body copper concentrations (13 ± 4 μg Cu g DW -1 ) were observed in algae exposed to 1 through 5 μg Cu L -1 and in daphnids exposed to 1 through 12 μg Cu L -1 . At higher exposure concentrations, there was an increase in internal body copper concentration, while no increase was observed in bioconcentration factors, suggesting the presence of a storage mechanism. At copper concentrations of 100 μg Cu L -1 (P. subcapitata) and 150 μg Cu L -1 (D. magna), the significant increases observed in body copper concentrations and in bioconcentration factors may be related to a failure of this regulation mechanism. For both organisms, internal body copper concentrations lower than 13 μg Cu g DW -1 may result in copper deficiency. For P. subcapitata acclimated to 0.5 and 100 μg Cu L -1 , body copper concentrations ranged (mean ± standard deviation) between 5 ± 2 μg Cu g DW -1 and 1300 ± 197 μg Cu g DW -1 , respectively. For D. magna, this value ranged between 9 ± 2 μg Cu g DW -1 and 175 ± 17 μg Cu g DW -1 for daphnids acclimated to 0.5 and 150 μg Cu L -1 . Multi-generation acclimation to copper concentrations ≥12 μg Cu L -1 resulted in a decrease (up to 40%) in body copper concentrations for both organisms compared to the body copper concentration of the first generation. It can be concluded that there is an indication that P. subcapitata and D. magna can regulate their whole body copper concentration to maintain copper homeostasis within their optimal copper range and

Copper and Anesthesia: Clinical Relevance and Management of Copper Related Disorders

OpenAIRE

Langley, Adrian; Dameron, Charles T.

2013-01-01

Recent research has implicated abnormal copper homeostasis in the underlying pathophysiology of several clinically important disorders, some of which may be encountered by the anesthetist in daily clinical practice. The purpose of this narrative review is to summarize the physiology and pharmacology of copper, the clinical implications of abnormal copper metabolism, and the subsequent influence of altered copper homeostasis on anesthetic management.

Industrial Tests to Modify Molten Copper Slag for Improvement of Copper Recovery

Science.gov (United States)

Guo, Zhengqi; Zhu, Deqing; Pan, Jian; Zhang, Feng; Yang, Congcong

2018-04-01

In this article, to improve the recovery of copper from copper slag by flotation process, industrial tests of the modification process involving addition of a composite additive into molten copper slag were conducted, and the modified slag was subjected to the flotation process to confirm the modification effect. The phase evolution of the slag in the modification process was revealed by thermodynamic calculations, x-ray diffraction, optical microscopy and scanning electron microscopy. The results show that more copper was transformed and enriched in copper sulfide phases. The magnetite content in the modified slag decreased, and that of "FeO" increased correspondingly, leading to a better fluidity of the molten slag, which improved the aggregation and growth of fine particles of the copper sulfide minerals. Closed-circuit flotation tests of the original and modified slags were conducted, and the results show that the copper recovery increased obviously from 69.15% to 73.38%, and the copper grade of concentrates was elevated slightly from 20.24% to 21.69%, further confirming that the industrial tests of the modification process were successful. Hence, the modification process has a bright future in industrial applications for enhancing the recovery of copper from the copper slag.

A natural analogue for copper waste canisters: The copper-uranium mineralised concretions in the Permian mudrocks of south Devon, United Kingdom

International Nuclear Information System (INIS)

Milodowski, A.E.; Styles, M.T.; Hards, V.L.

2000-08-01

thickness) of the copper sheets has been preserved in the saturated compacted clay environment of the Littleham Mudstone for many millions of years, at least since the end of the Lower Jurassic. Apart from the recent weathering effects due to exposure at outcrop, most of the observed corrosion and alteration of the native copper is geologically old and also occurred before the end of the Lower Jurassic. This demonstrates that the native copper can remain stable in a saturated and compacted clay environment for geological timescales (over 176 Ma) well in excess of the timescales considered for Performance Assessment. Since the copper sheets found in the Littleham Mudstone Formation are very thin (1-2 mm) and have survived over this long time, waste canisters - which will be made from much thicker copper - would be expected (by comparison) to show greater performance

A natural analogue for copper waste canisters: The copper-uranium mineralised concretions in the Permian mudrocks of south Devon, United Kingdom

Energy Technology Data Exchange (ETDEWEB)

Milodowski, A.E.; Styles, M.T.; Hards, V.L. [Natural Environment Research Council (United Kingdom). British Geological Survey

2000-08-01

-80% of the original thickness) of the copper sheets has been preserved in the saturated compacted clay environment of the Littleham Mudstone for many millions of years, at least since the end of the Lower Jurassic. Apart from the recent weathering effects due to exposure at outcrop, most of the observed corrosion and alteration of the native copper is geologically old and also occurred before the end of the Lower Jurassic. This demonstrates that the native copper can remain stable in a saturated and compacted clay environment for geological timescales (over 176 Ma) well in excess of the timescales considered for Performance Assessment. Since the copper sheets found in the Littleham Mudstone Formation are very thin (1-2 mm) and have survived over this long time, waste canisters - which will be made from much thicker copper - would be expected (by comparison) to show greater performance.

Synchrotron based x-ray fluorescence microscopy confirms copper in the corrosion products of metals in contact with treated wood

Science.gov (United States)

Samuel L. Zelinka; Joseph E. Jakes; Grant T. Kirker; David Vine; Stefan Vogt

2017-01-01

Copper based waterborne wood preservatives are frequently used to extend the service life of wood products when subjected to frequent moisture exposure. While these copper based treatments protect the wood from fungal decay and insect attack, they increase the corrosion of metals embedded or in contact with the treated wood. Previous research has shown the most...

Effects of light and copper ions on volatile aldehydes of milk and milk fractions

Energy Technology Data Exchange (ETDEWEB)

Jeno, W.; Bassette, R.; Crang, R.E.

1988-09-01

Raw, laboratory-pasteurized and plant-pasteurized homogenized milks were exposed to copper ions (5 ppm), to sunlight or fluorescent light and the effects determined on the composition of volatile aldehydes. The greatest change due to copper treatment was an increase in n-hexanal; acetaldehyde showed the least response in each of the sources of milk. The responses were similar from all three sources of milk with laboratory-pasteurized milk samples showing the greatest responses for each aldehyde analyzed. Similar milk samples exposed to sunlight also showed an increase in volatile aldehydes from all milk sources but with the greatest response being acetaldehyde and n-pentanal components. The milk fraction most susceptible to changes in the presence of light was neutralized whey, whereas resuspended cream was most susceptible to copper exposure. Overall, dialyzed whey appeared to be influenced more than other milk fractions by both light and copper ions.

Effect of Prolonged Exposure Therapy Delivered Over 2 Weeks vs 8 Weeks vs Present-Centered Therapy on PTSD Symptom Severity in Military Personnel: A Randomized Clinical Trial.

Science.gov (United States)

Foa, Edna B; McLean, Carmen P; Zang, Yinyin; Rosenfield, David; Yadin, Elna; Yarvis, Jeffrey S; Mintz, Jim; Young-McCaughan, Stacey; Borah, Elisa V; Dondanville, Katherine A; Fina, Brooke A; Hall-Clark, Brittany N; Lichner, Tracey; Litz, Brett T; Roache, John; Wright, Edward C; Peterson, Alan L

2018-01-23

Effective and efficient treatment is needed for posttraumatic stress disorder (PTSD) in active duty military personnel. To examine the effects of massed prolonged exposure therapy (massed therapy), spaced prolonged exposure therapy (spaced therapy), present-centered therapy (PCT), and a minimal-contact control (MCC) on PTSD severity. Randomized clinical trial conducted at Fort Hood, Texas, from January 2011 through July 2016 and enrolling 370 military personnel with PTSD who had returned from Iraq, Afghanistan, or both. Final follow-up was July 11, 2016. Prolonged exposure therapy, cognitive behavioral therapy involving exposure to trauma memories/reminders, administered as massed therapy (n = 110; 10 sessions over 2 weeks) or spaced therapy (n = 109; 10 sessions over 8 weeks); PCT, a non-trauma-focused therapy involving identifying/discussing daily stressors (n = 107; 10 sessions over 8 weeks); or MCC, telephone calls from therapists (n = 40; once weekly for 4 weeks). Outcomes were assessed before and after treatment and at 2-week, 12-week, and 6-month follow-up. Primary outcome was interviewer-assessed PTSD symptom severity, measured by the PTSD Symptom Scale-Interview (PSS-I; range, 0-51; higher scores indicate greater PTSD severity; MCID, 3.18), used to assess efficacy of massed therapy at 2 weeks posttreatment vs MCC at week 4; noninferiority of massed therapy vs spaced therapy at 2 weeks and 12 weeks posttreatment (noninferiority margin, 50% [2.3 points on PSS-I, with 1-sided α = .05]); and efficacy of spaced therapy vs PCT at posttreatment. Among 370 randomized participants, data were analyzed for 366 (mean age, 32.7 [SD, 7.3] years; 44 women [12.0%]; mean baseline PSS-I score, 25.49 [6.36]), and 216 (59.0%) completed the study. At 2 weeks posttreatment, mean PSS-I score was 17.62 (mean decrease from baseline, 7.13) for massed therapy and 21.41 (mean decrease, 3.43) for MCC (difference in decrease, 3.70 [95% CI,0.72 to 6.68]; P = .02

Comparison of phototoxic effects of pregnant rats exposure in Chernobyl NPP site and external prolonged exposure in the dose of 0.5 Gy

International Nuclear Information System (INIS)

Grigor'eva, E.E.; Rogov, Yu.I.

2007-01-01

The morphometric study showed that within the 10-kilometre zone of the Chernobyl NPP delay of the rat fetus cerebral cortex maturation occurred, whereas used in the experiment prolonged low-dose irradiation did not cause essential disorders of cortical ontogenesis.(authors)

Transcription patterns of genes encoding four metallothionein homologs in Daphnia pulex exposed to copper and cadmium are time- and homolog-dependent

International Nuclear Information System (INIS)

Asselman, Jana; Shaw, Joseph R.; Glaholt, Stephen P.; Colbourne, John K.; De Schamphelaere, Karel A.C.

2013-01-01

Highlights: •Transcription patterns of 4 metallothionein isoforms in Daphnia pulex. •Under cadmium and copper stress these patterns are time-dependent. •Under cadmium and copper stress these patterns are homolog-dependent. •The results stress the complex regulation of metallothioneins. -- Abstract: Metallothioneins are proteins that play an essential role in metal homeostasis and detoxification in nearly all organisms studied to date. Yet discrepancies between outcomes of chronic and acute exposure experiments hamper the understanding of the regulatory mechanisms of their isoforms following metal exposure. Here, we investigated transcriptional differences among four identified homologs (mt1–mt4) in Daphnia pulex exposed across time to copper and cadmium relative to a control. Transcriptional upregulation of mt1 and mt3 was detected on day four following exposure to cadmium, whereas that of mt2 and mt4 was detected on day two and day eight following exposure to copper. These results confirm temporal and metal-specific differences in the transcriptional induction of genes encoding metallothionein homologs upon metal exposure which should be considered in ecotoxicological monitoring programs of metal-contaminated water bodies. Indeed, the mRNA expression patterns observed here illustrate the complex regulatory system associated with metallothioneins, as these patterns are not only dependent on the metal, but also on exposure time and the homolog studied. Further phylogenetic analysis and analysis of regulatory elements in upstream promoter regions revealed a high degree of similarity between metallothionein genes of Daphnia pulex and Daphnia magna, a species belonging to the same genus. These findings, combined with a limited amount of available expression data for D. magna metallothionein genes, tentatively suggest a potential generalization of the metallothionein response system between these Daphnia species

Transcription patterns of genes encoding four metallothionein homologs in Daphnia pulex exposed to copper and cadmium are time- and homolog-dependent

Energy Technology Data Exchange (ETDEWEB)

Asselman, Jana, E-mail: jana.asselman@ugent.be [Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University, Ghent (Belgium); Shaw, Joseph R.; Glaholt, Stephen P. [The School of Public and Environmental Affairs, Indiana University, Bloomington, IN (United States); Colbourne, John K. [School of Biosciences, The University of Birmingham, Birmingham (United Kingdom); De Schamphelaere, Karel A.C. [Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University, Ghent (Belgium)

2013-10-15

Highlights: •Transcription patterns of 4 metallothionein isoforms in Daphnia pulex. •Under cadmium and copper stress these patterns are time-dependent. •Under cadmium and copper stress these patterns are homolog-dependent. •The results stress the complex regulation of metallothioneins. -- Abstract: Metallothioneins are proteins that play an essential role in metal homeostasis and detoxification in nearly all organisms studied to date. Yet discrepancies between outcomes of chronic and acute exposure experiments hamper the understanding of the regulatory mechanisms of their isoforms following metal exposure. Here, we investigated transcriptional differences among four identified homologs (mt1–mt4) in Daphnia pulex exposed across time to copper and cadmium relative to a control. Transcriptional upregulation of mt1 and mt3 was detected on day four following exposure to cadmium, whereas that of mt2 and mt4 was detected on day two and day eight following exposure to copper. These results confirm temporal and metal-specific differences in the transcriptional induction of genes encoding metallothionein homologs upon metal exposure which should be considered in ecotoxicological monitoring programs of metal-contaminated water bodies. Indeed, the mRNA expression patterns observed here illustrate the complex regulatory system associated with metallothioneins, as these patterns are not only dependent on the metal, but also on exposure time and the homolog studied. Further phylogenetic analysis and analysis of regulatory elements in upstream promoter regions revealed a high degree of similarity between metallothionein genes of Daphnia pulex and Daphnia magna, a species belonging to the same genus. These findings, combined with a limited amount of available expression data for D. magna metallothionein genes, tentatively suggest a potential generalization of the metallothionein response system between these Daphnia species.

Copper nitrate redispersion to arrive at highly active silica-supported copper catalysts

NARCIS (Netherlands)

Munnik, P.|info:eu-repo/dai/nl/328228524; Wolters, M.|info:eu-repo/dai/nl/304829560; Gabrielsson, A.; Pollington, S.D.; Headdock, G.; Bitter, J.H.|info:eu-repo/dai/nl/160581435; de Jongh, P.E.|info:eu-repo/dai/nl/186125372; de Jong, K.P.|info:eu-repo/dai/nl/06885580X

2011-01-01

In order to obtain copper catalysts with high dispersions at high copper loadings, the gas flow rate and gas composition was varied during calcination of silica gel impregnated with copper nitrate to a loading of 18 wt % of copper. Analysis by X-ray diffraction (XRD), N2O chemisorption, and

Copper economy in Chlamydomonas: Prioritized allocation and reallocation of copper to respiration vs. photosynthesis

Science.gov (United States)

Kropat, Janette; Gallaher, Sean D.; Urzica, Eugen I.; Nakamoto, Stacie S.; Strenkert, Daniela; Tottey, Stephen; Mason, Andrew Z.; Merchant, Sabeeha S.

2015-01-01

Inorganic elements, although required only in trace amounts, permit life and primary productivity because of their functions in catalysis. Every organism has a minimal requirement of each metal based on the intracellular abundance of proteins that use inorganic cofactors, but elemental sparing mechanisms can reduce this quota. A well-studied copper-sparing mechanism that operates in microalgae faced with copper deficiency is the replacement of the abundant copper protein plastocyanin with a heme-containing substitute, cytochrome (Cyt) c6. This switch, which is dependent on a copper-sensing transcription factor, copper response regulator 1 (CRR1), dramatically reduces the copper quota. We show here that in a situation of marginal copper availability, copper is preferentially allocated from plastocyanin, whose function is dispensable, to other more critical copper-dependent enzymes like Cyt oxidase and a ferroxidase. In the absence of an extracellular source, copper allocation to Cyt oxidase includes CRR1-dependent proteolysis of plastocyanin and quantitative recycling of the copper cofactor from plastocyanin to Cyt oxidase. Transcriptome profiling identifies a gene encoding a Zn-metalloprotease, as a candidate effecting copper recycling. One reason for the retention of genes encoding both plastocyanin and Cyt c6 in algal and cyanobacterial genomes might be because plastocyanin provides a competitive advantage in copper-depleted environments as a ready source of copper. PMID:25646490

Canine Copper-Associated Hepatitis

NARCIS (Netherlands)

Dirksen, Karen; Fieten, Hille

2017-01-01

Copper-associated hepatitis is recognized with increasing frequency in dogs. The disease is characterized by centrolobular hepatic copper accumulation, leading to hepatitis and eventually cirrhosis. The only way to establish the diagnosis is by histologic assessment of copper distribution and copper

Earth's copper resources estimated from tectonic diffusion of porphyry copper deposits

Science.gov (United States)

Kesler, Stephen E.; Wilkinson, Bruce H.

2008-03-01

Improved estimates of global mineral endowments are relevantto issues ranging from strategic planning to global geochemicalcycling. We have used a time-space model for the tectonic migrationof porphyry copper deposits vertically through the crust tocalculate Earth's endowment of copper in mineral deposits. Themodel relies only on knowledge of numbers and ages of porphyrycopper deposits, Earth's most widespread and important sourceof copper, in order to estimate numbers of eroded and preserveddeposits in the crust. Model results indicate that 125,895 porphyrycopper deposits were formed during Phanerozoic time, that only47,789 of these remain at various crustal depths, and that thesecontain 1.7 x 1011 tonnes (t) of copper. Assuming that othertypes of copper deposits behave similarly in the crust and haveabundances proportional to their current global production yieldsan estimate of 3 x 1011 t for total global copper resourcesat all levels in Earth's crust. Thus, 0.25% of the copper inthe crust has been concentrated into deposits through Phanerozoictime, and about two-thirds of this has been recycled by upliftand erosion. The amount of copper in deposits above 3.3 km,a likely limit of future mining, could supply current worldmine production for 5500 yr, thus quantifying the highly unusualand nonrenewable nature of mineral deposits.

Combined action of radiation, salts of copper and nickel on cell viability in vitro

Directory of Open Access Journals (Sweden)

D. D. Gapeenko

2014-09-01

Full Text Available Experimental study of the combined action of heavy metals and ionizing radiation on the viability of cells in culture was made. We established a significant toxic effect of copper and nickel in the proliferative and mitotic activity of cells in vitro. Under the combined effects of radiation and copper ions on cells we observed the mor-phological changes in morphologically-functional properties of cells that were determined by or radiation dose or by concentration of copper ions. While incubation of irradiated cells with nickel ions we observed sensitiza-tion of cells by nickel ions under the irradiation dose of 0.5 and 5.0 Gy, and the resistance of cells to exposure to sublethal dose of 10.0 Gy.

Bronchopulmonary C-fibers' IL1RI contributes to the prolonged apneic response to intra-atrial injection of capsaicin by prenatal nicotinic exposure in rat pups

Energy Technology Data Exchange (ETDEWEB)

Zhao, Lei; Zhuang, Jianguo; Xu, Fadi, E-mail: fxu@lrri.org

2016-07-15

Prenatal nicotinic exposure (PNE) as a SIDS model reportedly sensitizes bronchopulmonary C-fibers (PCFs), contributing to the prolonged PCF-mediated apnea in rat pups, but the relevant mechanisms are not fully understood. Pulmonary IL-1β upregulated by cigarette smoke is known to stimulate or sensitize PCFs acting via IL-1 type I receptor (IL1RI) and inhibit inspiration frequency. Because of its upregulation observed in SIDS victims, we hypothesized that PNE increased pulmonary IL-1β release and IL1RI expression in pulmonary C-neurons via action on α7 nicotinic acetylcholine receptors (α7nAChR) to induce the prolonged PCF-mediated apnea. IL-1β in BALF and IL1RI in the nodose/jugular (N/J) ganglion and vagal pulmonary C-neurons retrogradely-traced were compared between Ctrl (saline) and PNE pups and among the vehicle-treated Ctrl and PNE and methyllycaconitine (a selective α7nAChR antagonist)-treated PNE pups. The effect of IL-1RI blockade (IL-1Ra) on the PCF-mediated apnea was also compared between Ctrl and PNE pups. PNE significantly elevated IL-1β in BALF and upregulated IL1RI gene and protein expression in N/J ganglia and gene in vagal pulmonary C-neurons. All of these responses were eliminated by pretreatment with blockade of α7nAChR. In addition, the prolonged PCF-mediated apnea in PNE pups was significantly shortened by right atrial bolus injection of IL-1Ra. We conclude that PNE enhances pulmonary IL-1β release and PCF IL1RI expression acting via α7nAChR in contributing to sensitization of PCFs and prolongation of the PCF-mediated apneic response. - Highlights: • PNE increased pulmonary IL-1β release and IL1R1 expression in the N/J ganglia. • PNE elevated IL1R1 mRNA in vagal pulmonary C-neurons. • Blockage of peripheral IL1R1 reduced the PNE-induced PCF sensitization. • PNE induced the changes in IL-1β and IL1R1 dependent on action of α7nAChR.

Designing, Constructing and Installing a Local Exhaust Ventilation System to Minimize Welders\\' Exposure to Welding Fumes

Directory of Open Access Journals (Sweden)

Sajad Zare

2017-10-01

Full Text Available Background & Aims of the Study: Welder’s exposure to welding fumes can cause occupational diseases. The current study sought to examine exposure to welding fumes among welders who work in the repair shop of Sarcheshmeh Copper Complex and design a local exhaust ventilation system to control exposure to welding fumes. Materials & Methods: This applied analytical study was conducted in the summer of 2016 among welders working in the repair shop of Sarcheshmeh Copper Complex. The study comprised three phases; in the first one, welders’ exposure to welding fumes was assessed at the beginning of the study. After that, a local exhaust ventilation system was designed and installed in the aforementioned repair shop. In the final stage, welders’ exposure to welding fumes was assessed again after installation of the ventilation system. The procedure recommended by NIOSH (method number 7300 was used for individual sampling of welders. Results: Based on the obtained findings, before installing the ventilation system, welding technicians were exposed to 0.3 mg/m3 of copper fumes and 0.04 mg/m3 of chromium fumes. Journeyman welders were also exposed to 2.16 mg/m3 of manganese fumes, while stellar welders were exposed to 6.9 mg/m3 of iron fumes. In the light of these measurements, a local exhaust ventilation system was designed and installed. Subsequently, measurement of exposure to welding fumes showed a significant reduction. That is, welding technicians were exposed to 0.17 mg/m3 and 0.015 mg/m3 of copper and chromium fumes respectively. Additionally, journeyman welders were exposed to 0.86 mg/m3 of manganese fumes, whereas stellar welders were exposed to 4.3 mg/m3 of iron fumes. Conclusions: A comparison of standard limits of exposure to welding fumes and the results obtained from measurements in sampling stations before and after the installation of the local exhaust ventilation system reveals that this controlling measure was very effective in the

Involvement of purinergic system in inflammation and toxicity induced by copper in zebrafish larvae

Energy Technology Data Exchange (ETDEWEB)

Leite, Carlos Eduardo, E-mail: carlos.leite@pucrs.br [Instituto de Toxicologia e Farmacologia, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, CEP 90619-900 (Brazil); Programa de Pós-Graduação em Medicina: Ciências Médicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, CEP 90035-003 (Brazil); Maboni, Lucas de Oliveira [Instituto de Toxicologia e Farmacologia, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, CEP 90619-900 (Brazil); Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, CEP 90619-900 (Brazil); Cruz, Fernanda Fernandes [Instituto de Toxicologia e Farmacologia, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, CEP 90619-900 (Brazil); Faculdade de Farmácia, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, CEP 90619-900 (Brazil); Rosemberg, Denis Broock [Programa de Pós-graduação em Ciências Ambientais, Universidade Comunitária da Região de Chapecó, Chapecó, CEP 89809-000 (Brazil); and others

2013-11-01

The use of zebrafish (Danio rerio) is increasing as an intermediate preclinical model, to prioritize drug candidates for mammalian testing. As the immune system of the zebrafish is quite similar to that of mammals, models of inflammation are being developed for the screening of new drugs. The characterization of these models is crucial for studies that seek for mechanisms of action and specific pharmacological targets. It is well known that copper is a metal that induces damage and cell migration to hair cells of lateral line of zebrafish. Extracellular nucleotides/nucleosides, as ATP and adenosine (ADO), act as endogenous signaling molecules during tissue damage by exerting effects on inflammatory and immune responses. The present study aimed to characterize the inflammatory status, and to investigate the involvement of the purinergic system in copper-induced inflammation in zebrafish larvae. Fishes of 7 days post-fertilization were exposed to 10 μM of copper for a period of 24 h. The grade of oxidative stress, inflammatory status, copper uptake, the activity and the gene expression of the enzymes responsible for controlling the levels of nucleotides and adenosine were evaluated. Due to the copper accumulation in zebrafish larvae tissues, the damage and oxidative stress were exacerbated over time, resulting in an inflammatory process involving IL-1β, TNF-α, COX-2 and PGE{sub 2}. Within the purinergic system, the mechanisms that control the ADO levels were the most involved, mainly the reactions performed by the isoenzyme ADA 2. In conclusion, our data shed new lights on the mechanisms related to copper-induced inflammation in zebrafish larvae. - Graphical abstract: This scheme provides a chronological proposition for the biochemical events induced by copper in zebrafish larvae. The dashed line shows the absorption of copper over the exposure time. After 1 h of exposure to copper, the release of PGE{sub 2} occurs, followed by an increase of MPO (as a consequence

Involvement of purinergic system in inflammation and toxicity induced by copper in zebrafish larvae

International Nuclear Information System (INIS)

Leite, Carlos Eduardo; Maboni, Lucas de Oliveira; Cruz, Fernanda Fernandes; Rosemberg, Denis Broock

2013-01-01

The use of zebrafish (Danio rerio) is increasing as an intermediate preclinical model, to prioritize drug candidates for mammalian testing. As the immune system of the zebrafish is quite similar to that of mammals, models of inflammation are being developed for the screening of new drugs. The characterization of these models is crucial for studies that seek for mechanisms of action and specific pharmacological targets. It is well known that copper is a metal that induces damage and cell migration to hair cells of lateral line of zebrafish. Extracellular nucleotides/nucleosides, as ATP and adenosine (ADO), act as endogenous signaling molecules during tissue damage by exerting effects on inflammatory and immune responses. The present study aimed to characterize the inflammatory status, and to investigate the involvement of the purinergic system in copper-induced inflammation in zebrafish larvae. Fishes of 7 days post-fertilization were exposed to 10 μM of copper for a period of 24 h. The grade of oxidative stress, inflammatory status, copper uptake, the activity and the gene expression of the enzymes responsible for controlling the levels of nucleotides and adenosine were evaluated. Due to the copper accumulation in zebrafish larvae tissues, the damage and oxidative stress were exacerbated over time, resulting in an inflammatory process involving IL-1β, TNF-α, COX-2 and PGE 2 . Within the purinergic system, the mechanisms that control the ADO levels were the most involved, mainly the reactions performed by the isoenzyme ADA 2. In conclusion, our data shed new lights on the mechanisms related to copper-induced inflammation in zebrafish larvae. - Graphical abstract: This scheme provides a chronological proposition for the biochemical events induced by copper in zebrafish larvae. The dashed line shows the absorption of copper over the exposure time. After 1 h of exposure to copper, the release of PGE 2 occurs, followed by an increase of MPO (as a consequence of

Genome Sequences of Two Copper-Resistant Escherichia coli Strains Isolated from Copper-Fed Pigs

DEFF Research Database (Denmark)

Lüthje, Freja L.; Hasman, Henrik; Aarestrup, Frank Møller

2014-01-01

The draft genome sequences of two copper-resistant Escherichia coli strains were determined. These had been isolated from copper-fed pigs and contained additional putative operons conferring copper and other metal and metalloid resistances.......The draft genome sequences of two copper-resistant Escherichia coli strains were determined. These had been isolated from copper-fed pigs and contained additional putative operons conferring copper and other metal and metalloid resistances....

Copper uptake and retention in liver parenchymal cells isolated from nutritionally copper-deficient rats

NARCIS (Netherlands)

Berg, van den G.J.; de Goeij, J.J.M.; Bock, I.; Gijbels, M.J.J.; Brouwer, A.; Lei, K.Y.; Hendriks, H.F.J.

1991-01-01

Copper uptake and retention were studied in primary cultures of liver parenchymal cells isolated from copper-deficient rats. Male Sprague-Dawley rats were fed a copper-deficient diet (<1 mg Cu/kg) for 10 wk. Copper-deficient rats were characterized by low copper concentrations in plasma and liver,

Copper uptake and retention in liver parenchymal cells isolated from nutritionally copper-deficient rats

NARCIS (Netherlands)

Berg, G.J. van den; Goeij, J.J.M. de; Bock, I.; Gijbels, M.J.J.; Brouwer, A.; Lei, K.Y.; Hendruiks, H.F.J.

1991-01-01

Copper uptake and retention were studied in primary cultures of liver parenchymal cells isolated from copper-deficient rats. Male Sprague-Dawley rats were fed a copper-deficient diet (< 1 mg Cu/kg) for 10 wk. Copper-deficient rats were characterized by low copper concentrations in plasma and liver,

Annual Copper Mountain Conferences on Multigrid and Iterative Methods, Copper Mountain, Colorado

International Nuclear Information System (INIS)

McCormick, Stephen F.

2016-01-01

This project supported the Copper Mountain Conference on Multigrid and Iterative Methods, held from 2007 to 2015, at Copper Mountain, Colorado. The subject of the Copper Mountain Conference Series alternated between Multigrid Methods in odd-numbered years and Iterative Methods in even-numbered years. Begun in 1983, the Series represents an important forum for the exchange of ideas in these two closely related fields. This report describes the Copper Mountain Conference on Multigrid and Iterative Methods, 2007-2015. Information on the conference series is available at http://grandmaster.colorado.edu/~copper/

Annual Copper Mountain Conferences on Multigrid and Iterative Methods, Copper Mountain, Colorado

Energy Technology Data Exchange (ETDEWEB)

McCormick, Stephen F. [Front Range Scientific, Inc., Lake City, CO (United States)

2016-03-25

This project supported the Copper Mountain Conference on Multigrid and Iterative Methods, held from 2007 to 2015, at Copper Mountain, Colorado. The subject of the Copper Mountain Conference Series alternated between Multigrid Methods in odd-numbered years and Iterative Methods in even-numbered years. Begun in 1983, the Series represents an important forum for the exchange of ideas in these two closely related fields. This report describes the Copper Mountain Conference on Multigrid and Iterative Methods, 2007-2015. Information on the conference series is available at http://grandmaster.colorado.edu/~copper/.

Copper wire bonding

CERN Document Server

Chauhan, Preeti S; Zhong, ZhaoWei; Pecht, Michael G

2014-01-01

This critical volume provides an in-depth presentation of copper wire bonding technologies, processes and equipment, along with the economic benefits and risks.  Due to the increasing cost of materials used to make electronic components, the electronics industry has been rapidly moving from high cost gold to significantly lower cost copper as a wire bonding material.  However, copper wire bonding has several process and reliability concerns due to its material properties.  Copper Wire Bonding book lays out the challenges involved in replacing gold with copper as a wire bond material, and includes the bonding process changes—bond force, electric flame off, current and ultrasonic energy optimization, and bonding tools and equipment changes for first and second bond formation.  In addition, the bond–pad metallurgies and the use of bare and palladium-coated copper wires on aluminum are presented, and gold, nickel and palladium surface finishes are discussed.  The book also discusses best practices and re...

Exposure of metallic copper surface on Cu-Al2O3-carbon catalysts

NARCIS (Netherlands)

Menon, P.G.; Prasad, J.

1970-01-01

The bifunctional nature of Cu---Al2O3-on-carbon catalysts, used in the direct catalytic conversion of ethanol to ethyl acetate, prompted an examination of the dispersion of Cu on the composite catalyst. For this, the N2O-method of Osinga et al. for estimation of bare metallic copper surface on

Nearly 60% Copper Rod & Wire Companies Neutral about Future Copper Price

Institute of Scientific and Technical Information of China (English)

2012-01-01

<正>How about the trend of copper price recently? According to the survey result of Shanghai Metals Market, amongst 21 domestic copper rod & wire companies, 57% of the companies are neutral about the future copper price, while 14% and 19% of the companies consider that

Nutritional considerations during prolonged exposure to a confined, hyperbaric, hyperoxic environment: recommendations for saturation divers.

Science.gov (United States)

Deb, S K; Swinton, P A; Dolan, E

2016-01-01

Saturation diving is an occupation that involves prolonged exposure to a confined, hyperoxic, hyperbaric environment. The unique and extreme environment is thought to result in disruption to physiological and metabolic homeostasis, which may impact human health and performance. Appropriate nutritional intake has the potential to alleviate and/or support many of these physiological and metabolic concerns, whilst enhancing health and performance in saturation divers. Therefore, the purpose of this review is to identify the physiological and practical challenges of saturation diving and consequently provide evidence-based nutritional recommendations for saturation divers to promote health and performance within this challenging environment. Saturation diving has a high-energy demand, with an energy intake of between 44 and 52 kcal/kg body mass per day recommended, dependent on intensity and duration of underwater activity. The macronutrient composition of dietary intake is in accordance with the current Institute of Medicine guidelines at 45-65 % and 20-35 % of total energy intake for carbohydrate and fat intake, respectively. A minimum daily protein intake of 1.3 g/kg body mass is recommended to facilitate body composition maintenance. Macronutrient intake between individuals should, however, be dictated by personal preference to support the attainment of an energy balance. A varied diet high in fruit and vegetables is highly recommended for the provision of sufficient micronutrients to support physiological processes, such as vitamin B12 and folate intake to facilitate red blood cell production. Antioxidants, such as vitamin C and E, are also recommended to reduce oxidised molecules, e.g. free radicals, whilst selenium and zinc intake may be beneficial to reinforce endogenous antioxidant reserves. In addition, tailored hydration and carbohydrate fueling strategies for underwater work are also advised.

Homeostatic balance as an indicator of prolonged technogenic exposure in low dose range

International Nuclear Information System (INIS)

Karpov, A.B.; Voronova, I.A.; Takhauov, R.M.; Semyonova, Yu.V.; Sherstoboev, E.Yu.; Udut, V.V.

2008-01-01

Full text: Indication of changes induced by ionizing radiation starting up a wide range of pathologic reactions in the disease developments still poses a significant problem in radiation medicine. It mainly concerns exposure to low dose-rate ionizing radiation, since its effects are still open to question, and today any researcher acknowledges that radiation induced pathological changes can accumulate at both subclinical and prenosological stages and develop not only in exposed persons, but also in their offspring. The subject of this study was workers of reactor and radiochemical productions of Siberian Group of Chemical Enterprises (SGCE) exposed to external and combined (external and internal) radiation respectively. Two comparative groups were formed: reactor and radiochemical production workers. In the reactor production group of workers the cumulative dose of external γ-radiation was up to 300 mSv, in the radiochemical production group - up to 150 mSv. Age ranged from 40 to 50 years. The two groups were compared between each other. Above all, there were formed 'insider control' groups (workers of the same productions with zero doses) to assess the impact of radiation factor on central homeostatic mechanisms. These groups were created using pair technique in order to level somatic disorders influence on the parameters under study. Numbers of full and biochemical blood examinations, energy metabolism between cells, hormones of homeostasis by the adaptive hormone level - insulin and cortisol, lipid peroxidation and antioxidant protection systems, immune and vegetative systems were all analyzed. Analyses of the systems performed, it was found out that in persons having been exposed to long term occupational radiation there were significant changes indicating lipid peroxidation system activation, antioxidant protection system depression, as well as lowered energy metabolism. The higher external γ-doses the bigger these changes are. Results from the two groups of

CONCURRENT CONTACT SENSITIZATION TO METALS IN DENTAL EXPOSURES

Directory of Open Access Journals (Sweden)

Maya Lyapina

2018-03-01

Full Text Available Purpose: Sensitization to metals is a significant problem for both dental patients treated with dental materials and for dental professionals in occupational exposures. The purpose of the present study was to evaluate the incidence of concurrent contact sensitization to relevant for dental practice metals among students of dental medicine, students from dental technician school, dental professionals and patients. Material and Methods: A total of 128 participants were included in the study. All of them were patch-tested with nickel, cobalt, copper, potassium dichromate, palladium, aluminium, gold and tin. The results were subject to statistical analysis (p < 0.05. Results: For the whole studied population, potassium dichromate exhibited concomitant reactivity most often; copper and tin also often manifested co-reactivity. For the groups, exposed in dental practice, potassium dichromate and tin were outlined as the most often co-reacting metal allergens, but statistical significance concerning the co-sensitization to copper and the other metals was established only for aluminium. An increased incidence and OR for concomitant sensitization to cobalt and nickel was established in the group of dental students; to copper and nickel - in the control group; to palladium and nickel - in the group of dental professionals, the group of students of dental medicine and in the control group; to potassium dichromate and cobalt - in the group of dental students; to copper and palladium - in the control group of dental patients; to potassium dichromate and copper - in the group of dental professionals; to copper and aluminum - in the groups of students from dental technician school and of dental professionals; to copper and gold - in the groups of dental professionals and in the group of dental patients; to potassium dichromate and aluminum - in the group of dental professionals; to potassium dichromate and gold - in the group of dental professionals, and to

[Prolonged exposure to atmospheric air pollution and mortality from respiratory causes].

Science.gov (United States)

Eilstein, D

2009-12-01

Different designs can be used to analyze the relationships between respiratory mortality and long term exposure to atmospheric pollution: epidemiological studies (cohort, prevalence study) demonstrate the reality of the relationship and toxicological studies explain it. Cohort studies have the advantage of being able to take into account many confounding factors and thus avoid biases (which is not the case with prevalence studies), but require significant human and financial resources. They were first adopted in the US, but are now more often applied in Europe. The results are relatively consistent, as they all show a statistically significant association between an increase in particulate pollution and cardiopulmonary mortality. Mortality from lung cancer is also associated with long term exposition to particles and sometimes to ozone or nitrogen oxides. Cerebrovascular diseases and sudden death of young children have also been associated with particulate pollution. The relationships are more powerful for long term than short term exposure but are also linear and without threshold. In order to explain these effects (today the causality of the relationship is certain) there are many possible factors, particularly regarding particulate exposures: an increase in cardiovascular risk biomarkers (fibrinogen, white blood cells, and platelets), atherosclerosis, chronic inflammation of lung tissues increased by acute exposure, etc. More and more studies address the interaction between gene and environment and even epigenetic phenomena which could be responsible of these effects. Public Health impact could be quantified. The European E&H surveillance program Apheis, for example, estimated that if PM2.5 levels remained below 15 microg/m(3), a 30 year old person could see his life expectancy increased by 1 month to 2 years, depending on the studied city. Finally, mortality is not the only relevant indicator for health effects of air pollution. ISAAC studies address asthma

Licence prolongations of US nuclear power plants; Les prolongations de licence des centrales nucleaires americaines

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-04-01

Licences of US nuclear reactors were initially attributed for a 40 years duration. However, the vast majority of the reactors can benefit of a licence prolongation for a period of 20 years maximum. This article recalls first the procedure to follow for the licence prolongation demands (safety analysis, components aging, environmental impact statement), and then it makes a status of the accepted prolongations, of the demands under examination, and of the demands that should be presented in the next 5 years. (J.S.)

Suspension Flame Spray Construction of Polyimide-Copper Layers for Marine Antifouling Applications

Science.gov (United States)

Liu, Yi; Xu, Xiaomin; Suo, Xinkun; Gong, Yongfeng; Li, Hua

2018-01-01

Individual capsule-like polyimide splats have been fabricated by suspension flame spray, and the polyimide splat exhibits hollow structure with an inner pore and a tiny hole on its top surface. Enwrapping of 200-1000-nm copper particles inside the splats is accomplished during the deposition for constrained release of copper for antifouling performances. Antifouling testing of the coatings by 24-h exposure to Escherichia coli-containing artificial seawater shows that the Cu-doped splat already prohibits effectively attachment of the bacteria. The prohibited adhesion of bacteria obviously impedes formation and further development of bacterial biofilm. This capsulated splat with releasing and loading of copper biocides results in dual-functional structures bearing both release-killing and contact-killing mechanisms. The suspension flame spray route and the encapsulated structure of the polyimide-Cu coatings would open a new window for designing and constructing marine antifouling layers for long-term applications.

Biliary copper excretion by hepatocyte lysosomes in the rat. Major excretory pathway in experimental copper overload

International Nuclear Information System (INIS)

Gross, J.B. Jr.; Myers, B.M.; Kost, L.J.; Kuntz, S.M.; LaRusso, N.F.

1989-01-01

We investigated the hypothesis that lysosomes are the main source of biliary copper in conditions of hepatic copper overload. We used a rat model of oral copper loading and studied the relationship between the biliary output of copper and lysosomal hydrolases. Male Sprague-Dawley rats were given tap water with or without 0.125% copper acetate for up to 36 wk. Copper loading produced a 23-fold increase in the hepatic copper concentration and a 30-65% increase in hepatic lysosomal enzyme activity. Acid phosphatase histochemistry showed that copper-loaded livers contained an increased number of hepatocyte lysosomes; increased copper concentration of these organelles was confirmed directly by both x ray microanalysis and tissue fractionation. The copper-loaded rats showed a 16-fold increase in biliary copper output and a 50-300% increase in biliary lysosomal enzyme output. In the basal state, excretory profiles over time were similar for biliary outputs of lysosomal enzymes and copper in the copper-loaded animals but not in controls. After pharmacologic stimulation of lysosomal exocytosis, biliary outputs of copper and lysosomal hydrolases in the copper-loaded animals remained coupled: injection of colchicine or vinblastine produced an acute rise in the biliary output of both lysosomal enzymes and copper to 150-250% of baseline rates. After these same drugs, control animals showed only the expected increase in lysosomal enzyme output without a corresponding increase in copper output. We conclude that the hepatocyte responds to an increased copper load by sequestering excess copper in an increased number of lysosomes that then empty their contents directly into bile. The results provide direct evidence that exocytosis of lysosomal contents into biliary canaliculi is the major mechanism for biliary copper excretion in hepatic copper overload

Quantification of acute vocal fold epithelial surface damage with increasing time and magnitude doses of vibration exposure.

Directory of Open Access Journals (Sweden)

Tsuyoshi Kojima

Full Text Available Because the vocal folds undergo repeated trauma during continuous cycles of vibration, the epithelium is routinely susceptible to damage during phonation. Excessive and prolonged vibration exposure is considered a significant predisposing factor in the development of vocal fold pathology. The purpose of the present study was to quantify the extent of epithelial surface damage following increased time and magnitude doses of vibration exposure using an in vivo rabbit phonation model. Forty-five New Zealand white breeder rabbits were randomized to nine groups and received varying phonation time-doses (30, 60, or 120 minutes and magnitude-doses (control, modal intensity phonation, or raised intensity phonation of vibration exposure. Scanning electron microscopy and transmission electron microscopy was used to quantify the degree of epithelial surface damage. Results revealed a significant reduction in microprojection density, microprojection height, and depth of the epithelial surface with increasing time and phonation magnitudes doses, signifying increased epithelial surface damage risk with excessive and prolonged vibration exposure. Destruction to the epithelial cell surface may provide significant insight into the disruption of cell function following prolonged vibration exposure. One important goal achieved in the present study was the quantification of epithelial surface damage using objective imaging criteria. These data provide an important foundation for future studies of long-term tissue recovery from excessive and prolonged vibration exposure.

Degradation of graphene coated copper in simulated proton exchange membrane fuel cell environment: Electrochemical impedance spectroscopy study

Science.gov (United States)

Ren, Y. J.; Anisur, M. R.; Qiu, W.; He, J. J.; Al-Saadi, S.; Singh Raman, R. K.

2017-09-01

Metallic materials are most suitable for bipolar plates of proton exchange membrane fuel cell (PEMFC) because they possess the required mechanical strength, durability, gas impermeability, acceptable cost and are suitable for mass production. However, metallic bipolar plates are prone to corrosion or they can passivate under PEMFC environment and interrupt the fuel cell operation. Therefore, it is highly attractive to develop corrosion resistance coating that is also highly conductive. Graphene fits these criteria. Graphene coating is developed on copper by chemical vapor deposition (CVD) with an aim to improving corrosion resistance of copper under PEMFC condition. The Raman Spectroscopy shows the graphene coating to be multilayered. The electrochemical degradation of graphene coated copper is investigated by electrochemical impedance spectroscopy (EIS) in 0.5 M H2SO4 solution at room temperature. After exposure to the electrolyte for up to 720 h, the charge transfer resistance (Rt) of the graphene coated copper is ∼3 times greater than that of the bare copper, indicating graphene coatings could improve the corrosion resistance of copper bipolar plates.

Underwater explosive compaction-sintering of tungsten-copper coating on a copper surface

Science.gov (United States)

Chen, Xiang; Li, Xiaojie; Yan, Honghao; Wang, Xiaohong; Chen, Saiwei

2018-01-01

This study investigated underwater explosive compaction-sintering for coating a high-density tungsten-copper composite on a copper surface. First, 50% W-50% Cu tungsten-copper composite powder was prepared by mechanical alloying. The composite powder was pre-compacted and sintered by hydrogen. Underwater explosive compaction was carried out. Finally, a high-density tungsten-copper coating was obtained by diffusion sintering of the specimen after explosive compaction. A simulation of the underwater explosive compaction process showed that the peak value of the pressure in the coating was between 3.0 and 4.8 GPa. The hardness values of the tungsten-copper layer and the copper substrate were in the range of 87-133 and 49 HV, respectively. The bonding strength between the coating and the substrate was approximately 100-105 MPa.

Heart Rate Variability Frequency Domain Alterations among Healthy Nurses Exposed to Prolonged Work Stress.

Science.gov (United States)

Borchini, Rossana; Veronesi, Giovanni; Bonzini, Matteo; Gianfagna, Francesco; Dashi, Oriana; Ferrario, Marco Mario

2018-01-11

The deregulation of the autonomic nervous system assessed through the heart rate variability (HRV) analysis is a promising pathway linking work stress and cardiovascular diseases. We aim to investigate the associations between HRV High Frequency (HF) and Low Frequency (LF) powers and work stress in a sample of 36 healthy nurses. Perceived work stress was assessed twice one year apart, using the Job Content and Effort Reward Imbalance questionnaires. This allows to classify nurses in three exposure groups: "prolonged high stress" (PHS), "recent high stress" (RHS) and "stable low stress" (SLS). A 24-h ECG monitoring was later performed during a working day (WD) and a subsequent resting day (RD). Statistically significantly lower ( p working periods. In the subsequent resting periods, HF means showed increases over time in the RHS (beta = +0.41, p working and resting periods. Our study evidences that both prolonged and recent perceived high work stress were associated with a reduction of HF and LF powers during work. In addition, prolonged stress was associated with a lack of recovery during not-working and resting periods.

Electropolymerization of poly (aniline-co-o-anisidine) on copper and its anticorrosion properties

International Nuclear Information System (INIS)

Ozyilmaz, A T

2008-01-01

Poly(aniline-co-o-anisidine) of copolymer coatings was synthesized on the copper surface (Cu) with two different amounts of p-toluenesulfonic acid (p-TSA) added to the aqueous sodium oxalate (NaOX) solution. The copper substrates in NaOX solutions containing p-TSA acid had a fairly reliable passive surface mainly due to the formation of copper (II) oxalate layer. The addition of p-TSA acid to the working electrolyte contributed to both the amount of copolymer deposition (growth) and that of copolymer coated per unit time of electropolymerization (growth rate). The growth of copolymer coating on Cu electrode was characterized by scanning electron microscopy. The corrosion performances of copolymer coatings were investigated in 3.5% NaCl solution with anodic polarization curves and electrochemical impedance spectroscopy. The results showed that p-TSA acid led to the diminishing of the permeability of the copolymer films. The copolymer coatings exhibited an effective barrier property on copper electrode and a remarkable anodic protection to substrate for longer exposure time

Structural and functional changes in the gastric intramural nervous plexus in emotionally stressed rats exposed to low doses of prolonged ionizing radiation and lead

International Nuclear Information System (INIS)

Lapsha, V.I.; Bocharova, V.N.; Utkina, L.N.; Rolevich, I.V.

1999-01-01

Changes in the catecholamine content in adrenergic fibres, acethylcholinesterase activity, and in the energy metabolism enzymes lactate dehydrogenase and succinate dehydrogenase in neurons of the gastric intramural plexus during emotional stress in rats a day after combined exposure to prolonged (30 days) ionizing radiation at a total dose 1.0 Gy and 0.6 mg/kg lead were studied. A decrease in catecholamines in adrenergic fibres and acethylcholinesterase and lactate dehydrogenase activity in neurons was observed. An enhanced sensitivity of the gastric intramural plexus after the prolonged exposure to small doses of ionizing radiation and lead in conditions of emotional stress was suggested [ru

Sulfidation treatment of copper-containing plating sludge towards copper resource recovery.

Science.gov (United States)

Kuchar, D; Fukuta, T; Onyango, M S; Matsuda, H

2006-11-02

The present study is concerned with the sulfidation treatment of copper-containing plating sludge towards copper resource recovery by flotation of copper sulfide from treated sludge. The sulfidation treatment was carried out by contacting simulated or real copper plating sludge with Na(2)S solution for a period of 5 min to 24 h. The initial molar ratio of S(2-) to Cu(2+) (S(2-) to Me(2+) in the case of real sludge) was adjusted to 1.00, 1.25 or 1.50, while the solid to liquid ratio was set at 1:50. As a result, it was found that copper compounds were converted to various copper sulfides within the first 5 min. In the case of simulated copper sludge, CuS was identified as the main sulfidation product at the molar ratio of S(2-) to Cu(2+) of 1.00, while Cu(7)S(4) (Roxbyite) was mainly found at the molar ratios of S(2-) to Cu(2+) of 1.50 and 1.25. Based on the measurements of oxidation-reduction potential, the formation of either CuS or Cu(7)S(4) at different S(2-) to Cu(2+) molar ratios was attributed to the changes in the oxidation-reduction potential. By contrast, in the case of sulfidation treatment of real copper sludge, CuS was predominantly formed, irrespective of S(2-) to Me(2+) molar ratio.

Quality of drug label information on QT interval prolongation

DEFF Research Database (Denmark)

Warnier, Miriam J; Holtkamp, Frank A; Rutten, Frans H

2014-01-01

BACKGROUND: Information regarding QT-prolongation in the drug label may vary between products. This could lead to suboptimal risk minimization strategies. OBJECTIVE: To systematically assess the variation in the extent and content of information on QT prolongation in the summary of product......-prolongation'/'QT-prolongation') and the advice on cautionary measures pertaining to QT-prolongation in the label were examined, as well as their association. RESULTS: Of the 175 screened products, 44 contained information on QT in the SPC ('no QT-prolongation': 23%, 'unclear drug-QT association': 43%, 'possibly QT-prolongation': 16%, 'QT......-prolongation': 18%). 62% contained advices to act with caution in patients with additional risk factors for QT-prolongation. Products that more likely to have QT-prolonging properties according to the SPC provided more information on QT-prolongation in the SPC ('no prolongation': 10% and for the category 'QT...

Assessment of antifungal effects of copper nanoparticles on the growth of the fungus Saprolegnia sp. on white fish (Rutilus frisii kutum eggs

Directory of Open Access Journals (Sweden)

Pegah Kalatehjari

2015-12-01

Full Text Available This study was conducted to evaluate the in-vitro effects of copper nanoparticles on the growth of the fungus Saprolegnia sp. isolated from white fish (Rutilus frisii kutum eggs. The antifungal effects were measured by determining the minimum lethal concentration of copper nanoparticles on Saprolegnia sp. in yeast extract glucose chloramphenicol (YGC agar at 25 °C. Saprolegnia grown in YGC agar without added copper nanoparticles served as negative controls. Our study showed that copper nanoparticles at a minimum concentration of 10 ppm have antifungal effects on Saprolegnia sp. The antifungal effects of copper nanoparticles are positively correlated to both concentration and time of exposure. This study showed that the antifungal properties of copper nanoparticles make it a good alternative to malachite green, which is carcinogenic.

Inhibition of spontaneous recovery of fear by mGluR5 after prolonged extinction training.

Directory of Open Access Journals (Sweden)

Sheng-Chun Mao

Full Text Available Fear behavior is vital for survival and involves learning contingent associations of non-threatening cues with aversive stimuli. In contrast, excessive levels of fear can be maladaptive and lead to anxiety disorders. Generally, extensive sessions of extinction training correlates with reduced spontaneous recovery. The molecular mechanisms underlying the long-term inhibition of fear recovery following repeated extinction training are not fully understood. Here we show that in rats, prolonged extinction training causes greater reduction in both fear-potentiated startle and spontaneous recovery. This effect was specifically blocked by metabotropic glutamate receptor 5 (mGluR5, but not by mGluR1 antagonists and by a protein synthesis inhibitor. Similar inhibition of memory recovery following prolonged extinction training was also observed in mice. In agreement with the instrumental role of mGluR5 in the prolonged inhibition of fear recovery, we found that FMR1-/- mice which exhibit enhanced mGluR5-mediated signaling exhibit lower spontaneous recovery of fear after extinction training than wild-type littermates. At the molecular level, we discovered that prolonged extinction training reversed the fear conditioning-induced increase in surface expression of GluR1, AMPA/NMDA ratio, postsynaptic density-95 (PSD-95 and synapse-associated protein-97 (SAP97. Accordingly, delivery of Tat-GluR2(3Y, a synthetic peptide that blocks AMPA receptor endocytosis, inhibited prolonged extinction training-induced inhibition of fear recovery. Together, our results demonstrate that prolonged extinction training results in the mGluR5-dependent long-term inhibition of fear recovery. This effect may involve the degradation of original memory and may explain the beneficial effects of prolonged exposure therapy for the treatment of phobias.

Inhibition of spontaneous recovery of fear by mGluR5 after prolonged extinction training.

Science.gov (United States)

Mao, Sheng-Chun; Chang, Chih-Hua; Wu, Chia-Chen; Orejarena, M Juliana; Orejanera, Maria Juliana; Manzoni, Olivier J; Gean, Po-Wu

2013-01-01

Fear behavior is vital for survival and involves learning contingent associations of non-threatening cues with aversive stimuli. In contrast, excessive levels of fear can be maladaptive and lead to anxiety disorders. Generally, extensive sessions of extinction training correlates with reduced spontaneous recovery. The molecular mechanisms underlying the long-term inhibition of fear recovery following repeated extinction training are not fully understood. Here we show that in rats, prolonged extinction training causes greater reduction in both fear-potentiated startle and spontaneous recovery. This effect was specifically blocked by metabotropic glutamate receptor 5 (mGluR5), but not by mGluR1 antagonists and by a protein synthesis inhibitor. Similar inhibition of memory recovery following prolonged extinction training was also observed in mice. In agreement with the instrumental role of mGluR5 in the prolonged inhibition of fear recovery, we found that FMR1-/- mice which exhibit enhanced mGluR5-mediated signaling exhibit lower spontaneous recovery of fear after extinction training than wild-type littermates. At the molecular level, we discovered that prolonged extinction training reversed the fear conditioning-induced increase in surface expression of GluR1, AMPA/NMDA ratio, postsynaptic density-95 (PSD-95) and synapse-associated protein-97 (SAP97). Accordingly, delivery of Tat-GluR2(3Y), a synthetic peptide that blocks AMPA receptor endocytosis, inhibited prolonged extinction training-induced inhibition of fear recovery. Together, our results demonstrate that prolonged extinction training results in the mGluR5-dependent long-term inhibition of fear recovery. This effect may involve the degradation of original memory and may explain the beneficial effects of prolonged exposure therapy for the treatment of phobias.

Control of biofouling on titanium condenser tubes with the use of electroless copper plating

International Nuclear Information System (INIS)

Anandkumar, B.; George, R.P.; Kamachi Mudali, U.; Ramachandran, D.

2015-01-01

In sea water environments titanium condenser tubes face serious issues of biofouling and biomineralization. Electroless plating of nanocopper film is attempted inside the tubes for the control of biofilm formation. Using advanced techniques like AFM, SEM, and XPS, electroless copper plated flat Ti specimens were characterized. Examination of Cu coated Ti surfaces using AFM and SEM showed more reduction in the microroughness compared to anodized Ti surface. Cu 2p 3/2 peak in XPS spectral analysis showed the shift in binding energy inferring the reduction of the hydroxide to metallic copper. Tubular specimens were exposed to sea water up to three months and withdrawn at monthly intervals to evaluate antibacterial activity and long term stability of the coating. Total viable counts and epifluorescence microscopy analyses showed two orders decrease in bacterial counts on copper coated Ti specimens when compared to as polished control Ti specimens. Molecular biology techniques like DGGE and protein expression analysis system were done to get insight into the community diversity and copper tolerance of microorganisms. DGGE gel bands clearly showed the difference in the bacterial diversity inferring from the 16S rRNA gene fragments (V3 regions). Protein analysis showed distinct protein spots appearing in electroless copper coated Ti biofilm protein samples in addition to protein spots common to both the biofilms of Cu coated and as polished Ti. The results indicated copper accumulating proteins in copper resistant bacterial species of biofilm. Reduced microroughness of the surface and toxic copper ions resulted in good biofouling control even after three months exposure to sea water. (author)

Single Intravenous Dose of Novel Flurbiprofen-Loaded Proniosome Formulations Provides Prolonged Systemic Exposure and Anti-inflammatory Effect.

Science.gov (United States)

Verma, Preeti; Prajapati, Sunil K; Yadav, Rajbharan; Senyschyn, Danielle; Shea, Peter R; Trevaskis, Natalie L

2016-11-07

hydrated proniosomes can prolong systemic drug exposure over 3 days and provide a sustained therapeutic effect. The developed proniosomes represent a novel approach to treat acute pain and inflammation with the potential to be administered as a single intravenous dose by a clinician at the time of injury or surgery that provides adequate relief for several days and reduces fluctuations in therapy. Similar systems loaded with different drugs have potential for broader application in anesthesia, anti-infective, antiemetic, and cancer therapy.

A cytosolic copper storage protein provides a second level of copper tolerance in Streptomyces lividans.

Science.gov (United States)

Straw, Megan L; Chaplin, Amanda K; Hough, Michael A; Paps, Jordi; Bavro, Vassiliy N; Wilson, Michael T; Vijgenboom, Erik; Worrall, Jonathan A R

2018-01-24

Streptomyces lividans has a distinct dependence on the bioavailability of copper for its morphological development. A cytosolic copper resistance system is operative in S. lividans that serves to preclude deleterious copper levels. This system comprises of several CopZ-like copper chaperones and P 1 -type ATPases, predominantly under the transcriptional control of a metalloregulator from the copper sensitive operon repressor (CsoR) family. In the present study, we discover a new layer of cytosolic copper resistance in S. lividans that involves a protein belonging to the newly discovered family of copper storage proteins, which we have named Ccsp (cytosolic copper storage protein). From an evolutionary perspective, we find Ccsp homologues to be widespread in Bacteria and extend through into Archaea and Eukaryota. Under copper stress Ccsp is upregulated and consists of a homotetramer assembly capable of binding up to 80 cuprous ions (20 per protomer). X-ray crystallography reveals 18 cysteines, 3 histidines and 1 aspartate are involved in cuprous ion coordination. Loading of cuprous ions to Ccsp is a cooperative process with a Hill coefficient of 1.9 and a CopZ-like copper chaperone can transfer copper to Ccsp. A Δccsp mutant strain indicates that Ccsp is not required under initial copper stress in S. lividans, but as the CsoR/CopZ/ATPase efflux system becomes saturated, Ccsp facilitates a second level of copper tolerance.

Fabricating Copper Nanotubes by Electrodeposition

Science.gov (United States)

Yang, E. H.; Ramsey, Christopher; Bae, Youngsam; Choi, Daniel

2009-01-01

Copper tubes having diameters between about 100 and about 200 nm have been fabricated by electrodeposition of copper into the pores of alumina nanopore membranes. Copper nanotubes are under consideration as alternatives to copper nanorods and nanowires for applications involving thermal and/or electrical contacts, wherein the greater specific areas of nanotubes could afford lower effective thermal and/or electrical resistivities. Heretofore, copper nanorods and nanowires have been fabricated by a combination of electrodeposition and a conventional expensive lithographic process. The present electrodeposition-based process for fabricating copper nanotubes costs less and enables production of copper nanotubes at greater rate.

Evaluation of low copper content antifouling paints containing natural phenolic compounds as bioactive additives.

Science.gov (United States)

Pérez, Miriam; García, Mónica; Blustein, Guillermo

2015-08-01

Cuprous oxide is the most commonly used biocide in antifouling paints. However, copper has harmful effects not only on the fouling community but also on non-target species. In the current study, we investigated the use of thymol, eugenol and guaiacol in this role combined with small quantities of copper. Phenolic compounds were tested for anti-settlement activity against cyprid larvae of the barnacle Balanus amphitrite and for their toxicity to nauplius larvae. Thymol, eugenol and guaiacol were active for anti-settlement but guaiacol had the disadvantage of being toxic to nauplius larvae. However, all of them showed therapeutic ratio>1. Antifouling paints with thymol (low copper content/thymol, LCP/T), eugenol (low copper content/eugenol, LCP/E) and guaiacol (low copper content/guaiacol, LCP/G) combined with small copper content were formulated for field trials. After 12 months exposure in the sea, statistical analysis revealed that LCP/T and LCP/E paints were the most effective combinations and had similar performances to control paints with high copper content (traditional cuprous oxide based paints). In contrast, LCP/G paint was only partially effective in preventing and inhibiting biofouling and was colonized by some hard and soft foulers. However, this antifouling paint was effective against calcareous tubeworm Hydroides elegans. In the light of various potential applications, thymol, eugenol and guaiacol have thus to be considered in future antifouling formulations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Differential pulmonary and cardiac effects of pulmonary exposure to a panel of particulate matter-associated metals

International Nuclear Information System (INIS)

Wallenborn, J. Grace; Schladweiler, Mette J.; Richards, Judy H.; Kodavanti, Urmila P.

2009-01-01

Biological mechanisms underlying the association between particulate matter (PM) exposure and increased cardiovascular health effects are under investigation. Water-soluble metals reaching systemic circulation following pulmonary exposure are likely exerting a direct effect. However, it is unclear whether specific PM-associated metals may be driving this. We hypothesized that exposure to equimolar amounts of five individual PM-associated metals would cause differential pulmonary and cardiac effects. We exposed male WKY rats (14 weeks old) via a single intratracheal instillation (IT) to saline or 1 μmol/kg body weight of zinc, nickel, vanadium, copper, or iron in sulfate form. Responses were analyzed 4, 24, 48, or 96 h after exposure. Pulmonary effects were assessed by bronchoalveolar lavage fluid levels of total cells, macrophages, neutrophils, protein, albumin, and activities of lactate dehydrogenase, γ-glutamyl transferase, and n-acetyl glucosaminidase. Copper induced earlier pulmonary injury/inflammation, while zinc and nickel produced later effects. Vanadium or iron exposure induced minimal pulmonary injury/inflammation. Zinc, nickel, or copper increased serum cholesterol, red blood cells, and white blood cells at different time points. IT of nickel and copper increased expression of metallothionein-1 (MT-1) in the lung. Zinc, nickel, vanadium, and iron increased hepatic MT-1 expression. No significant changes in zinc transporter-1 (ZnT-1) expression were noted in the lung or liver; however, zinc increased cardiac ZnT-1 at 24 h, indicating a possible zinc-specific cardiac effect. Nickel exposure induced an increase in cardiac ferritin 96 h after IT. This data set demonstrating metal-specific cardiotoxicity is important in linking metal-enriched anthropogenic PM sources with adverse health effects.

Effects of vacuum processing erbium dideuteride/ditritide films deposited on chromium underlays on copper substrates

International Nuclear Information System (INIS)

Provo, J.L.

1978-01-01

Thin films of erbium dideuteride/ditritide were experimentally produced on chromium underlays deposited on copper substrates. The chromium underlay is required to prevent erbium occluder/copper substrate alloying which inhibits hydriding. Data taken has shown that vacuum processing affects the erbium/chromium/copper interaction. With an in situ process in which underlay/occluder films are vacuum deposited onto copper substrates and hydrided with no air exposure between these steps, data indicates a minimum of 1500A of chromium is required for optimum hydriding. If films are vacuum deposited as above and air-exposed before hydriding, a minimum of 3000A of chromium was shown to be required for equivalent hydriding. Data suggests that the activation step (600 0 C for 1 hour) required for hydriding the film of the second type is responsible for the difference observed. Such underlay thickness parameters are important, with regard to heat transfer considerations in thin hydride targets used for neutron generation

Prolonged hypoxia modulates platelet activating factor receptor-mediated responses by fetal ovine pulmonary vascular smooth muscle cells.

Science.gov (United States)

Renteria, Lissette S; Raj, J Usha; Ibe, Basil O

2010-12-01

Hypoxia augments PAF receptor (PAFr) binding and PAFr protein expression in venous SMC (SMC-PV). We compared effect of acute and prolonged hypoxia (pO(2)<40 torr) on PAFr-mediated responses in arterial SMC (SMC-PA) and SMC-PV. Cells were studied for 30 min (acute) or for 48 h (prolonged) hypoxia and compared to normoxic (pO(2) ~100 torr) conditions. PAF binding was quantified in fmol/10(6) cells (mean ± SEM). PAF binding in normoxia were SMC-PA, 5.2 ± 0.2 and in SMC-PV, 19.3 ± 1.1; values in acute hypoxia were SMC-PA, 7.7 ± 0.4 and in SMC-PV, 27.8 ± 1.7. Prolonged hypoxia produced 6-fold increase in binding in SMC-PA, but only 2-fold increase in SMC-PV, but binding in SMC-PV was still higher. Acute hypoxia augmented inositol phosphate release by 50% and 40% in SMC-PA and SMC-PV, respectively. During normoxia, PAFr mRNA expression by both cell types was similar, but expression in hypoxia by SMC-PA was greater. In SMC-PA, hypoxia and PAF augmented intracellular calcium flux. Re-exposure of cells to 30 min normoxia after 48 h hypoxia decreased binding by 45-60%, suggesting immediate down-regulation of hypoxia-induced PAFr-mediated effects. We speculate that re-oxygenation immediately reverses hypoxia effect probably due to oxygen tension-dependent reversibility of PAFr activation and suggest that exposure of the neonate to prolonged state of hypoxia will vilify oxygen exchange capacity of the neonatal lungs. Copyright © 2010 Elsevier Inc. All rights reserved.

Prolonged pregnancy: Methods, Causal Determinants and Outcome

DEFF Research Database (Denmark)

Olesen, Annette Wind

Summary Prolonged pregnancy, defined as a pregnancy with a gestational length of 294 days or more, is a frequent condition. It is associated with an increased risk of fetal and maternal complications. Little is known about the aetiology of prolonged pregnancy. The aims of the thesis were 1......) to study the incidence of prolonged pregnancy as a function of methods for determining gestational age; 2) to determine the risk of obstetrical and fetal complications in prolonged pregnancy; 3) to validate the self-reported gestational age in the National Birth Cohort; 4) to determine whether...... the risk of recurrence of prolonged pregnancy as a function of change in male partner and social conditions (IV). The National Birth Cohort provided data for the study on prenatal risk indicators of prolonged pregnancy in a follow-up design (V). The self-reported gestational ages from this database...

Electrochemical in-situ impregnation of wood using a copper nail as source for copper

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Block, Thomas; Nymark, Morten

2011-01-01

A new method for copper impregnation of wood in structures was suggested and tested in laboratory scale with specimen of new pine sapwood. A copper nail and a steel screw were placed in the wood, and an electric direct current field was applied, so the copper nail was anode and the screw...... was cathode. At the anode, copper ions were generated. The copper ions were transported into the wood by electromigration (movement of ions in an applied electric field) towards the cathode, and a volume between the two electrodes was thereby impregnated. Copper also moved to a lesser degree in the opposite...

Prolonged CT urography in duplex kidney.

Science.gov (United States)

Gong, Honghan; Gao, Lei; Dai, Xi-Jian; Zhou, Fuqing; Zhang, Ning; Zeng, Xianjun; Jiang, Jian; He, Laichang

2016-05-13

Duplex kidney is a common anomaly that is frequently associated with multiple complications. Typical computed tomography urography (CTU) includes four phases (unenhanced, arterial, parenchymal and excretory) and has been suggested to considerably aid in the duplex kidney diagnosi. Unfortunately, regarding duplex kidney with prolonged dilatation, the affected parenchyma and tortuous ureters demonstrate a lack of or delayed excretory opacification. We used prolonged-delay CTU, which consists of another prolonged-delay phase (1- to 72-h delay; mean delay: 24 h) to opacify the duplicated ureters and affected parenchyma. Seventeen patients (9 males and 8 females; age range: 2.5-56 y; mean age: 40.4 y) with duplex kidney were included in this study. Unenhanced scans did not find typical characteristics of duplex kidney, except for irregular perirenal morphology. Duplex kidney could not be confirmed on typical four-phase CTU, whereas it could be easily diagnosed in axial and CT-3D reconstruction using prolonged CTU (prolonged-delay phase). Between January 2005 and October 2010, in this review board-approved study (with waived informed consent), 17 patients (9 males and 8 females; age range: 2.5 ~ 56 y; mean age: 40.4 y) with suspicious duplex kidney underwent prolonged CTU to opacify the duplicated ureters and confirm the diagnosis. Our results suggest the validity of prolonged CTU to aid in the evaluation of the function of the affected parenchyma and in the demonstration of urinary tract malformations.

Response of Microcystis to copper stress - Do phenotypes of Microcystis make a difference in stress tolerance?

International Nuclear Information System (INIS)

Wu Zhongxing; Gan Nanqin; Huang Qun; Song Lirong

2007-01-01

To elucidate the role of phenotype in stress-tolerant bloom-forming cyanobacterium Microcystis, two phenotypes of M. aeruginosa - unicellular and colonial strains were selected to investigate how they responded to copper stress. Flow cytometry (FCM) examination indicated that the percents of viable cells in unicellular and colonial Microcystis were 1.92-2.83% and 72.3-97.51%, respectively, under 0.25 mg l -1 copper sulfate treatment for 24 h. Upon exposure to 0.25 mg l -1 copper sulfate, the activities of antioxidative enzyme, such as superoxide dismutase (SOD) and catalase (CAT), were significantly increased in colonial Microcystis compared to unicellular Microcystis. Meanwhile, the values of the photosynthetic parameters (F v /F m , ETR max , and oxygen evolution rate) decreased more rapidly in unicellular Microcystis than in colonial Microcystis. The results indicate that colonial Microcystis has a higher endurance to copper than unicellular Microcystis. This suggests that the efficient treatment concentration of copper sulfate as algaecides will be dependent on the phenotypes of Microcystis. - Stress-resistance ability in Microcystis is influenced by its phenotypes

Copper Leaching from Copper-ethanolamine Treated Wood: Comparison of Field Test Studies and Laboratory Standard Procedures

OpenAIRE

Nejc Thaler; Miha Humar

2014-01-01

Copper-based compounds are some of the most important biocides for the protection of wood in heavy duty applications. In the past, copper was combined with chromium compounds to reduce copper leaching, but a recent generation of copper-based preservatives uses ethanolamine as a fixative. To elucidate the leaching of copper biocides from wood, Norway spruce (Picea abies) wood was treated with a commercial copper-ethanolamine solution with two different copper concentrations (cCu = 0.125% and 0...

Development of a new passive sampler based on diffusive milligel beads for copper analysis in water

International Nuclear Information System (INIS)

Perez, M.; Reynaud, S.; Lespes, G.; Potin-Gautier, M.; Mignard, E.; Chéry, P.; Schaumlöffel, D.; Grassl, B.

2015-01-01

A new passive sampler was designed and characterized for the determination of free copper ion (Cu 2+ ) concentration in aqueous solution. Each sampling device was composed of a set of about 30 diffusive milligel (DMG) beads. Milligel beads with incorporated cation exchange resin (Chelex) particles were synthetized using an adapted droplet-based millifluidic process. Beads were assumed to be prolate spheroids, with a diameter of 1.6 mm and an anisotropic factor of 1.4. The milligel was controlled in chemical composition of hydrogel (monomer, cross-linker, initiator and Chelex concentration) and characterized in pore size. Two types of sampling devices were developed containing 7.5% and 15% of Chelex, respectively, and 6 nm pore size. The kinetic curves obtained demonstrated the accumulation of copper in the DMG according to the process described in the literature as absorption (and/or adsorption) and release following the Fick's first law of diffusion. For their use in water monitoring, the typical physico-chemical characteristics of the samplers, i.e. the mass-transfer coefficient (k 0 ) and the sampler-water partition coefficient (K sw ), were determined based on a static exposure design. In order to determine the copper concentration in the samplers after their exposure, a method using DMG bead digestion combined to Inductively Coupled Plasma – Atomic Emission Spectrometry (ICP-AES) analysis was developed and optimized. The DMG devices proved to be capable to absorb free copper ions from an aqueous solution, which could be accurately quantified with a mean recovery of 99% and a repeatability of 7% (mean relative uncertainty). - Highlights: • Controlled geometry of new passive sampler with ellipsoidal shape. • Original manufacturing process based on droplet-based millifluidic device. • Pore size characterization of the sampler. • Mass-transfer and sampler-water partitioning coefficients by static exposure experiments

Development of a new passive sampler based on diffusive milligel beads for copper analysis in water

Energy Technology Data Exchange (ETDEWEB)

Perez, M.; Reynaud, S.; Lespes, G.; Potin-Gautier, M. [Université de Pau et des Pays de l’Adour/CNRS UMR IPREM 5254, Hélioparc, 2 av. du Président Angot, 64053 Pau (France); Mignard, E. [CNRS-Solvay-Université Bordeaux, UMR5258, Laboratoire du Futur, 178 Avenue du Dr. A. Schweitzer, 33608 Pessac Cedex (France); Chéry, P. [Bordeaux Science Agro, 1 cours du Général De Gaulle, Gradignan, 33175 (France); Schaumlöffel, D. [Université de Pau et des Pays de l’Adour/CNRS UMR IPREM 5254, Hélioparc, 2 av. du Président Angot, 64053 Pau (France); Grassl, B., E-mail: bruno.grassl@univ-pau.fr [Université de Pau et des Pays de l’Adour/CNRS UMR IPREM 5254, Hélioparc, 2 av. du Président Angot, 64053 Pau (France)

2015-08-26

A new passive sampler was designed and characterized for the determination of free copper ion (Cu{sup 2+}) concentration in aqueous solution. Each sampling device was composed of a set of about 30 diffusive milligel (DMG) beads. Milligel beads with incorporated cation exchange resin (Chelex) particles were synthetized using an adapted droplet-based millifluidic process. Beads were assumed to be prolate spheroids, with a diameter of 1.6 mm and an anisotropic factor of 1.4. The milligel was controlled in chemical composition of hydrogel (monomer, cross-linker, initiator and Chelex concentration) and characterized in pore size. Two types of sampling devices were developed containing 7.5% and 15% of Chelex, respectively, and 6 nm pore size. The kinetic curves obtained demonstrated the accumulation of copper in the DMG according to the process described in the literature as absorption (and/or adsorption) and release following the Fick's first law of diffusion. For their use in water monitoring, the typical physico-chemical characteristics of the samplers, i.e. the mass-transfer coefficient (k{sub 0}) and the sampler-water partition coefficient (K{sub sw}), were determined based on a static exposure design. In order to determine the copper concentration in the samplers after their exposure, a method using DMG bead digestion combined to Inductively Coupled Plasma – Atomic Emission Spectrometry (ICP-AES) analysis was developed and optimized. The DMG devices proved to be capable to absorb free copper ions from an aqueous solution, which could be accurately quantified with a mean recovery of 99% and a repeatability of 7% (mean relative uncertainty). - Highlights: • Controlled geometry of new passive sampler with ellipsoidal shape. • Original manufacturing process based on droplet-based millifluidic device. • Pore size characterization of the sampler. • Mass-transfer and sampler-water partitioning coefficients by static exposure experiments.

Copper metabolism: a multicompartmental model of copper kinetics in the rat

International Nuclear Information System (INIS)

Dunn, M.A.

1985-01-01

A qualitative multicompartmental model was developed that describes the whole-body kinetics of copper metabolism in the adult rat. The model was developed from radiocopper percent dose vs. time data measured over a three day period in plasma, liver, skin, skeletal muscle, bile and feces after the intravenous injection of 10 μg copper labeled with 64 Cu. Plasma radiocopper was separated into ceruloplasmin (Cp) and nonceruloplasmin (NCp) fractions. Liver cytosolic radiocopper was fractionated into void volume superoxide dismutase (SOD) containing and metallothionein fractions by gel filtration. Liver particulate fractions were isolated by differential centrifugation. The SAAM and CONSAM modeling programs were used to develop the model. The sizes of compartments, fractional rate constants and mass transfer rates between compartments were evaluated. The intracellular metabolism of copper was similar in hepatic and extrahepatic tissues being comprised of a faster turning over compartment (FTC) exchanging copper with NCp and a slower turning over compartment (STC) with input from Cp. Output from the STC was into the FTC. In the liver the STC was postulated to represent SOD copper which unlike the extrahepatic tissues received much of its input from the FTC. A small amount of biliary copper (9%) was postulated to return to plasma NCp by enterohepatic recycling. The model developed was contrasted and compared with two previous models of copper metabolism

Evaluation of sphingolipids in Wistar rats treated to prolonged and single oral doses of fumonisin b₁.

Science.gov (United States)

Direito, Glória M; Almeida, Adriana P; Aquino, Simone; dos Reis, Tatiana Alves; Pozzi, Claudia Rodrigues; Corrêa, Benedito

2009-01-01

The objective of the present study was to evaluate sphingolipid levels (sphingosine-So and sphinganine-Sa) and to compare the Sa/So ratio in liver, serum and urine of Wistar rats after prolonged administration (21 days) of fumonisin B(1) (FB(1)). In parallel, the kinetics of sphingolipid elimination in urine was studied in animals receiving a single dose of FB(1). Prolonged exposure to FB(1) caused an increase in Sa levels in urine, serum and liver. The most marked effect on sphingolipid biosynthesis was observed in animals treated with the highest dose of FB(1). Animals receiving a single dose of FB(1) presented variations in Sa and So levels and in the Sa/So ratio.

Beta-lactam antibiotic-induced platelet dysfunction: Evidence for irreversible inhibition of platelet activation in vitro and in vivo after prolonged exposure to penicillin

International Nuclear Information System (INIS)

Burroughs, S.F.; Johnson, G.J.

1990-01-01

beta-Lactam antibiotics cause platelet dysfunction with bleeding complications. Previous in vitro studies documented reversible inhibition of agonist-receptor interaction. This mechanism is inadequate to explain the effect of beta-lactam antibiotics in vivo. Platelet function does not return to normal immediately after drug treatment, implying irreversible inhibition of platelet function. We report here evidence of irreversible platelet functional and biochemical abnormalities after in vitro and in vivo exposure to beta-lactam antibiotics. Irreversible binding of [14C]-penicillin (Pen) occurred in vitro. After 24 hours' in vitro incubation with 10 to 20 mmol/L Pen, or ex vivo after antibiotic treatment, irreversible functional impairment occurred; but no irreversible inhibition of alpha 2 adrenergic receptors, measured with [3H]-yohimbine, or high-affinity thromboxane A2/prostaglandin H2 (TXA2/PGH2) receptors, measured with agonist [3H]-U46619 and antagonist [3H]-SQ29548, occurred. However, low-affinity platelet TXA2/PGH2 receptors were decreased 40% after Pen exposure in vitro or in vivo, indicating irreversible membrane alteration. Two postreceptor biochemical events were irreversibly inhibited in platelets incubated with Pen for 24 hours in vitro or ex vivo after antibiotic treatment. Thromboxane synthesis was inhibited 28.3% to 81.7%. Agonist-induced rises in cytosolic calcium ([Ca2+]i) were inhibited 40.1% to 67.5% in vitro and 26.6% to 52.2% ex vivo. Therefore, Pen binds to platelets after prolonged exposure, resulting in irreversible dysfunction attributable to inhibition of TXA2 synthesis and impairment of the rise in [Ca2+]i. The loss of low-affinity TXA2/PGH2 receptors suggests that the primary site of action of these drugs is on the platelet membrane

Potential phytoextraction and phytostabilization of perennial peanut on copper-contaminated vineyard soils and copper mining waste.

Science.gov (United States)

Andreazza, Robson; Bortolon, Leandro; Pieniz, Simone; Giacometti, Marcelo; Roehrs, Dione D; Lambais, Mácio R; Camargo, Flávio A O

2011-12-01

This study sought to evaluate the potential of perennial peanut (Arachis pintoi) for copper phytoremediation in vineyard soils (Inceptisol and Mollisol) contaminated with copper and copper mining waste. Our results showed high phytomass production of perennial peanut in both vineyard soils. Macronutrient uptakes were not negatively affected by perennial peanut cultivated in all contaminated soils. Plants cultivated in Mollisol showed high copper concentrations in the roots and shoots of 475 and 52 mg kg(-1), respectively. Perennial peanut plants showed low translocation factor values for Cu, although these plants showed high bioaccumulation factor (BCF) for both vineyard soils, Inceptisol and Mollisol, with BCF values of 3.83 and 3.24, respectively, being characterized as a copper hyperaccumulator plant in these soils. Copper phytoextraction from Inceptisol soil was the highest for both roots and entire plant biomass, with more than 800 mg kg(-1) of copper in whole plant. The highest potential copper phytoextraction by perennial peanut was in Inceptisol soil with copper removal of 2,500 g ha(-1). Also, perennial peanut showed high potential for copper phytoremoval in copper mining waste and Mollisol with 1,700 and 1,500 g of copper per hectare, respectively. In addition, perennial peanuts characterized high potential for phytoextraction and phytostabilization of copper in vineyard soils and copper mining waste.

Evaluation of the hazard associated with fabricating beryllium copper alloys

International Nuclear Information System (INIS)

Senn, T.J.

1977-01-01

Beryllium-copper alloys should be considered toxic materials and proper controls must be used when they are machined, heated, or otherwise fabricated. Air samples should be taken for each type of fabrication to determine the worker's exposure and the effectiveness of the controls in use. It has been shown that aerosols containing beryllium are generated during the four methods of fabrication tested, and that these aerosols can be reduced through local exhaust to undetectable levels. Considering the acute, chronic and possibly carcinogenic effects of exposure to beryllium, effective controls should be required because they are feasible both technologically and economically. The health hazards and control measures are reviewed

Renal cortex copper concentration in acute copper poisoning in calves

Directory of Open Access Journals (Sweden)

Luis E. Fazzio

2012-01-01

Full Text Available The aim of this study was to estimate the diagnostic value of renal cortex copper (Cu concentration in clinical cases of acute copper poisoning (ACP. A total of 97 calves that died due to subcutaneous copper administration were compiled in eleven farms. At least, one necropsy was conducted on each farm and samples for complementary analysis were taken. The degree of autolysis in each necropsy was evaluated. The cases appeared on extensive grazing calf breeding and intensive feedlot farms, in calves of 60 to 200 kg body weight. Mortality varied from 0.86 to 6.96 %, on the farms studied. The first succumbed calf was found on the farms between 6 and 72 hours after the susbcutaneous Cu administration. As discrepancies regarding the reference value arose, the local value (19.9 parts per million was used, confirming the diagnosis of acute copper poisoning in 93% of the analyzed kidney samples. These results confirm the value of analysis of the cortical kidney Cu concentration for the diagnosis of acute copper poisoning.

The effects of prolonged oral administration of the disinfectant calcium hypochlorite in Nigerian commercial cockerels

Directory of Open Access Journals (Sweden)

Temitayo O. Iji

2013-11-01

Full Text Available This study was designed to investigate the effects of prolonged oral administration of calcium hypochlorite in the drinking water of commercial cockerels. It was carried out in order to ascertain probable toxicity associated with prolonged exposure to calcium hypochlorite. Thirty-two healthy birds were used; they were grouped into four groups of eight. Group 1, which served as the control, received 10 mL/kg body weight of physiological saline. Groups 2, 3 and 4 received 0.0375 g, 0.375 g and 0.75 g of calcium hypochlorite per 10 litres of drinking water for six weeks respectively. Six weeks after the administration of calcium hypochlorite, blood was collected from the jugular vein to assess liver function, lipid profiles and for markers of oxidative stress. The results revealed a significant (p < 0.05 increase in alanine aminotransferase activity in a dose-dependent manner when compared with the control. Also, there was a significant (p < 0.05 increase in aspartate aminotransferase and alkaline phosphatase activity. Similarly, there was a significant (p < 0.05 increase in total cholesterol, triglycerides, high-density lipoprotein and low-density lipoprotein levels compared with the control. There was a significant increase in malondialdehyde and hydrogen peroxide generation with a concomitant significant (p < 0.05 decrease in serum glutathione level in a dose-dependent manner when compared with the control. In this study, calcium hypochloriteinduced hepatic damage via oxidative stress and decrease in antioxidant defense system was found. Therefore, prolonged exposure of chickens to calcium hypochlorite is potentially harmful.

Preparation of copper and silicon/copper powders by a gas ...

Indian Academy of Sciences (India)

Administrator

aCentre for Materials Research, Department of Imaging and Applied Physics, ... Copper powder; Si/Cu composite particle; gas evaporation–condensation method; characteriza- tion. .... from the liquid metal surface, the mixed vapour of copper.

Posttranslational regulation of copper transporters

NARCIS (Netherlands)

van den Berghe, P.V.E.

2009-01-01

The transition metal copper is an essential cofactor for many redox-active enzymes, but excessive copper can generate toxic reactive oxygen species. Copper homeostasis is maintained by highly conserved proteins, to balance copper uptake, distribution and export on the systemic and cellular level.

RECYCLING OF SCRAP AND WASTE OF COPPER AND COPPER ALLOYS IN BELARUS

Directory of Open Access Journals (Sweden)

S. L. Rovin

2017-01-01

Full Text Available The construction of a new casting and mechanical shop of unitary enterprise «Tsvetmet» in December 2015 has allowed to solve the complex problem of processing and utilization of scrap and wastes of copper and copper alloys in the Republic of Belarus. The technological processes of fire refinement of copper and manufacturing of copper rod from scrap and production of brass rod by hot pressing (extrusion of the continuously casted round billet have been mastered for the first time in the Republic of Belarus.

Demystifying Controlling Copper Corrosion

Science.gov (United States)

The LCR systematically misses the highest health and corrosion risk sites for copper. Additionally, there are growing concerns for WWTP copper in sludges and discharge levels. There are many corrosion control differences between copper and lead. This talk explains the sometimes c...

Prolonged menstrual cycles in female workers exposed to ethylene glycol ethers in the semiconductor manufacturing industry.

Science.gov (United States)

Hsieh, G-Y; Wang, J-D; Cheng, T-J; Chen, P-C

2005-08-01

It has been shown that female workers exposed to ethylene glycol ethers (EGEs) in the semiconductor industry have higher risks of spontaneous abortion, subfertility, and menstrual disturbances, and prolonged waiting time to pregnancy. To examine whether EGEs or other chemicals are associated with long menstrual cycles in female workers in the semiconductor manufacturing industry. Cross-sectional questionnaire survey during the annual health examination at a wafer manufacturing company in Taiwan in 1997. A three tiered exposure-assessment strategy was used to analyse the risk. A short menstrual cycle was defined to be a cycle less than 24 days and a long cycle to be more than 35 days. There were 606 valid questionnaires from 473 workers in fabrication jobs and 133 in non-fabrication areas. Long menstrual cycles were associated with workers in fabrication areas compared to those in non-fabrication areas. Using workers in non-fabrication areas as referents, workers in photolithography and diffusion areas had higher risks for long menstrual cycles. Workers exposed to EGEs and isopropanol, and hydrofluoric acid, isopropanol, and phosphorous compounds also showed increased risks of a long menstrual cycle. Exposure to multiple chemicals, including EGEs in photolithography, might be associated with long menstrual cycles, and may play an important role in a prolonged time to pregnancy in the wafer manufacturing industry; however, the prevalence in the design, possible exposure misclassification, and chance should be considered.

Copper Bioleaching in Chile

OpenAIRE

Juan Carlos Gentina; Fernando Acevedo

2016-01-01

Chile has a great tradition of producing and exporting copper. Over the last several decades, it has become the first producer on an international level. Its copper reserves are also the most important on the planet. However, after years of mineral exploitation, the ease of extracting copper oxides and ore copper content has diminished. To keep the production level high, the introduction of new technologies has become necessary. One that has been successful is bioleaching. Chile had the first...

[Brain function recovery after prolonged posttraumatic coma].

Science.gov (United States)

Klimash, A V; Zhanaidarov, Z S

2016-01-01

To explore the characteristics of brain function recovery in patients after prolonged posttraumatic coma and with long-unconscious states. Eighty-seven patients after prolonged posttraumatic coma were followed-up for two years. An analysis of a clinical/neurological picture after a prolonged episode of coma was based on the dynamics of vital functions, neurological status and patient's reactions to external stimuli. Based on the dynamics of the clinical/neurological picture that shows the recovery of functions of the certain brain areas, three stages of brain function recovery after a prolonged episode of coma were singled out: brain stem areas, diencephalic areas and telencephalic areas. These functional/anatomic areas of brain function recovery after prolonged coma were compared to the present classifications.

Long-term corrosion of copper in a dilute anaerobic sulfide solution

Energy Technology Data Exchange (ETDEWEB)

Chen, J.; Qin, Z. [Department of Chemistry, University of Western Ontario, London, Ontario, N6A 5B7 (Canada); Shoesmith, D.W., E-mail: dwshoesm@uwo.ca [Department of Chemistry, University of Western Ontario, London, Ontario, N6A 5B7 (Canada)

2011-09-30

The mechanism of corrosion of oxygen-free copper has been studied in stagnant aqueous sulfide solutions using corrosion potential and electrochemical impedance spectroscopy (EIS) measurements. Film structure and composition were examined on surfaces and on cross-sections prepared by focused ion beam (FIB) milling using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Experiments were conducted in anaerobic 5 x 10{sup -5} mol dm{sup -3} Na{sub 2}S + 0.1 mol dm{sup -3} NaCl solutions for exposure periods up to 4000 h ({approx}167 days) to mimic (at least partially) the conditions that could develop on a copper nuclear fuel waste container in a deep geologic repository. The corrosion film formed was a single cellular Cu{sub 2}S layer with a non-uniform thickness. The film thickness increased approximately linearly with immersion time, which implied that the sulfide film formed on the Cu surface is non-protective under these conditions up to this exposure time. The film growth process was controlled by HS{sup -} diffusion partially in the aqueous solution in the pores in the cellular sulfide film and partially in the bulk of the aqueous solution.

[Pathophysiology of prolonged hypokinesia].

Science.gov (United States)

Kovalenko, E A

1976-01-01

Hypokinesia is an important problem in modern medicine. In the pathogenetic effect of prolonged hypokinesia the main etiological factor is diminished motor activity; of major importance are disorders in the energy and plastic metabolism which affect the muscle system; the contributing factors are cardiovascular deconditioning and orthostatic intolerance. This is attributed to a decreased oxygen supply and eliminated hydrostatic influences during a prolonged recumbency. Blood redistribution in the vascular bed is related to the Gauer-Henry reflex and subsequent changes in the fluid-electrolyte balance. Decreased load on the bone system induces changes in the protein-phosphate-calcium metabolism, diminished bone density and increased calcium content in the blood and urine. Changes in the calcium metabolism are systemic. The activity of the higher nervous system and reflex functions is lowered. Changes in the function of the autonomic nervous system which include a noticeable decline of its adaptive-trophic role as a result of the decrease of afferent and efferent impulsation are of great importance. Changes in the hormonal function involve a peculiar stress-reaction which develops at an early stage of hypokinesia as a response to an unusual situation. Prolonged hypokinesia may result in a disturbed function of the pituitary-adrenal system. It is assumed that prolonged hypokinesia may induce a specific disease of hypokinesia during which man cannot lead a normal mode of life and work.

The copper-transporting ATPase pump and its potential role in copper-tolerance

Science.gov (United States)

Katie Ohno; C.A. Clausen; Frederick Green; G. Stanosz

2016-01-01

Copper-tolerant brown-rot decay fungi exploit intricate mechanisms to neutralize the efficacy of copper-containing preservative formulations. The production and accumulation oxalate is the most widely recognized theory regarding the mechanism of copper-tolerance in these fungi. The role of oxalate, however, may be only one part of a series of necessary components...

Electrochemical methods to study hydrogen production during interaction of copper with deoxygenated aqueous solution

International Nuclear Information System (INIS)

Lilja, Christina; Betova, Iva; Bojinov, Martin

2016-01-01

In some countries, spent nuclear fuel is planned to be encapsulated in canisters with a copper shell for corrosion protection, for further disposal in geologic repositories. The possibilities for corrosion after oxygen depletion must be evaluated, even if copper is considered to be immune in oxygen-free water. To follow the interaction of copper with deoxygenated aqueous solution, open-circuit potentiometric and electrochemical impedance measurements have been coupled to in-situ detection of cupric ion, dissolved molecular hydrogen and oxygen concentrations using electrochemical sensors. A kinetic model that considers the production of hydrogen as a catalytic process, the rate of which is proportional to the surface coverage of an intermediate species formed during interaction between copper and the solution is used to interpret the results. Kinetic parameters are estimated by a simultaneous fit of the experimental impedance spectra, the open circuit potential and cupric ion concentration as depending on temperature (22–70 °C) and exposure time (up to 720 h) to the model equations. Using the obtained values and a balance equation of hydrogen production on copper and its diffusion out of the cell through its walls, the kinetic parameters of this process are estimated by fitting dissolved molecular hydrogen concentration vs. time data at the three temperatures.

Maternal exposure to metals—Concentrations and predictors of exposure

International Nuclear Information System (INIS)

Callan, A.C.; Hinwood, A.L.; Ramalingam, M.; Boyce, M.; Heyworth, J.; McCafferty, P.; Odland, J.Ø.

2013-01-01

A variety of metals are important for biological function but have also been shown to impact health at elevated concentrations, whereas others have no known biological function. Pregnant women are a vulnerable population and measures to reduce exposure in this group are important. We undertook a study of maternal exposure to the metals, aluminium, arsenic, copper, cobalt, chromium, lithium, manganese, nickel, selenium, tin, uranium and zinc in 173 participants across Western Australia. Each participant provided a whole blood and urine sample, as well as drinking water, residential soil and dust samples and completed a questionnaire. In general the concentrations of metals in all samples were low with the notable exception of uranium (blood U mean 0.07 µg/L, range <0.01–0.25 µg/L; urinary U mean 0.018 µg/g creatinine, range <0.01–0.199 µg/g creatinine). Factors that influenced biological concentrations were consumption of fish which increased urinary arsenic concentrations, hobbies (including mechanics and welding) which increased blood manganese concentrations and iron/folic acid supplement use which was associated with decreased concentrations of aluminium and nickel in urine and manganese in blood. Environmental concentrations of aluminium, copper and lithium were found to influence biological concentrations, but this was not the case for other environmental metals concentrations. Further work is underway to explore the influence of diet on biological metals concentrations in more detail. The high concentrations of uranium require further investigation. -- Highlights: • High concentrations of uranium with respect to international literature. • Environmental concentrations of Al, Cu and Li influenced urinary concentrations. • Exposure to mechanics/welding hobbies increased blood Mn concentrations. • Iron/Folic acid supplements reduced biological concentrations of Al, Ni and Mn

Maternal exposure to metals—Concentrations and predictors of exposure

Energy Technology Data Exchange (ETDEWEB)

Callan, A.C., E-mail: a.callan@ecu.edu.au [Centre for Ecosystem Management, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA 6027 (Australia); Hinwood, A.L.; Ramalingam, M.; Boyce, M. [Centre for Ecosystem Management, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA 6027 (Australia); Heyworth, J. [School Population Health, The University of Western Australia, 35 Stirling Highway Crawley, WA 6009 (Australia); McCafferty, P. [ChemCentre, PO Box 1250, Bentley, WA 6983 (Australia); Odland, J.Ø. [Department of Community Medicine, University of Tromsø, N-9037 Tromsø (Norway)

2013-10-15

A variety of metals are important for biological function but have also been shown to impact health at elevated concentrations, whereas others have no known biological function. Pregnant women are a vulnerable population and measures to reduce exposure in this group are important. We undertook a study of maternal exposure to the metals, aluminium, arsenic, copper, cobalt, chromium, lithium, manganese, nickel, selenium, tin, uranium and zinc in 173 participants across Western Australia. Each participant provided a whole blood and urine sample, as well as drinking water, residential soil and dust samples and completed a questionnaire. In general the concentrations of metals in all samples were low with the notable exception of uranium (blood U mean 0.07 µg/L, range <0.01–0.25 µg/L; urinary U mean 0.018 µg/g creatinine, range <0.01–0.199 µg/g creatinine). Factors that influenced biological concentrations were consumption of fish which increased urinary arsenic concentrations, hobbies (including mechanics and welding) which increased blood manganese concentrations and iron/folic acid supplement use which was associated with decreased concentrations of aluminium and nickel in urine and manganese in blood. Environmental concentrations of aluminium, copper and lithium were found to influence biological concentrations, but this was not the case for other environmental metals concentrations. Further work is underway to explore the influence of diet on biological metals concentrations in more detail. The high concentrations of uranium require further investigation. -- Highlights: • High concentrations of uranium with respect to international literature. • Environmental concentrations of Al, Cu and Li influenced urinary concentrations. • Exposure to mechanics/welding hobbies increased blood Mn concentrations. • Iron/Folic acid supplements reduced biological concentrations of Al, Ni and Mn.

The impact of prolonged violent video-gaming on adolescent sleep: an experimental study.

Science.gov (United States)

King, Daniel L; Gradisar, Michael; Drummond, Aaron; Lovato, Nicole; Wessel, Jason; Micic, Gorica; Douglas, Paul; Delfabbro, Paul

2013-04-01

Video-gaming is an increasingly prevalent activity among children and adolescents that is known to influence several areas of emotional, cognitive and behavioural functioning. Currently there is insufficient experimental evidence about how extended video-game play may affect adolescents' sleep. The aim of this study was to investigate the short-term impact of adolescents' prolonged exposure to violent video-gaming on sleep. Seventeen male adolescents (mean age = 16 ± 1 years) with no current sleep difficulties played a novel, fast-paced, violent video-game (50 or 150 min) before their usual bedtime on two different testing nights in a sleep laboratory. Objective (polysomnography-measured sleep and heart rate) and subjective (single-night sleep diary) measures were obtained to assess the arousing effects of prolonged gaming. Compared with regular gaming, prolonged gaming produced decreases in objective sleep efficiency (by 7 ± 2%, falling below 85%) and total sleep time (by 27 ± 12 min) that was contributed by a near-moderate reduction in rapid eye movement sleep (Cohen's d = 0.48). Subjective sleep-onset latency significantly increased by 17 ± 8 min, and there was a moderate reduction in self-reported sleep quality after prolonged gaming (Cohen's d = 0.53). Heart rate did not differ significantly between video-gaming conditions during pre-sleep game-play or the sleep-onset phase. Results provide evidence that prolonged video-gaming may cause clinically significant disruption to adolescent sleep, even when sleep after video-gaming is initiated at normal bedtime. However, physiological arousal may not necessarily be the mechanism by which technology use affects sleep. © 2012 European Sleep Research Society.

Physiological serum copper concentrations found in malignancies cause unfolding induced aggregation of human serum albumin in vitro.

Science.gov (United States)

Rizvi, Asim; Furkan, Mohd; Naseem, Imrana

2017-12-15

Malignancies are characterized by several drastic metabolic changes, one of which is a progressive rise in the levels of serum copper. This rise in serum copper is documented across all malignancies and across malignancies in several species. This study aims to explore in vitro the effect of increased copper levels on the structure of the blood protein human serum albumin. Exposure of human serum albumin to physiologically relevant copper concentrations for 21 days resulted in structural modifications in the protein which were evident by changes in the intrinsic florescence. A loss of the predominantly alpha helical structure of human serum albumin was recorded along with a tendency to form protein aggregates. This aggregation was characterized by Thioflavin T and Congo Red assays. Rayleigh light scattering and turbidity assays confirmed aggregation. The aggregates were visually confirmed using transmission electron microscopy. This is the first report implicating increased copper levels as a cause of aggregation of blood proteins in malignancies. The physiological and biochemical implications of this phenomenon are discussed. Copyright © 2017. Published by Elsevier Inc.

Use of copper radioisotopes in investigating disorders of copper metabolism

International Nuclear Information System (INIS)

Camakaris, J.; Voskoboinik, I.; Brooks, H.; Greenough, M.; Smith, S.; Mercer, J.

1998-01-01

Full text: Copper is an essential trace element for life as a number of vital enzymes require it. Copper deficiency can lead to neurological disorders, osteoporosis and weakening of arteries. However Cu is also highly toxic and homeostatic mechanisms have evolved to maintain Cu at levels which satisfy requirements but do not cause toxicity. Toxicity is mediated by the oxidative capacity of Cu and its ability to generate toxic free radicals. There are several acquired and inherited diseases due to either Cu toxicity or Cu deficiency. The study of these diseases facilitates identification of genes and proteins involved in copper homeostasis, and this in turn will provide rational therapeutic approaches. Our studies have focused on Menkes disease in humans which is an inherited and usually lethal copper deficiency. Using copper radioisotopes 64 Cu (t 1/2 = 12.8 hr) and 67 Cu (t 1/2 = 61 hr) we have studied the protein which is mutated in Menkes disease. This is a transmembrane copper pump which is responsible for absorption of copper into the body and also functions to pump out excess Cu from cells when Cu is elevated. It is therefore a vital component of normal Cu homeostasis. We have provided the first biochemical evidence that the Menkes protein functions as a P-type ATPase Cu pump (Voskoboinik et al., FEBS Letters, in press) and these data will be discussed. The assay involved pumping of radiocopper into purified membrane vesicles. Furthermore we have transfected normal and mutant Menkes genes into cells and are carrying out structure-function studies. We are also studying the role of amyloid precursor protein (APP) as a Cu transport protein in order to determine how Cu regulates this protein and its cleavage products. These studies will provide vital information on the relationship between Cu and APP and processes which lead to Alzheimers disease

Recovery of Copper from Copper Slag by Hydrometallurgy Method, from Iraqi Factories Waste

Directory of Open Access Journals (Sweden)

Bahaa Sami Mahdi

2018-05-01

Full Text Available   In this research, the recovery of copper from copper slag is investigated using hydrometallurgy method. Slag samples were taken from Al-Shaheed State Company. The results of the chemical analysis showed that the slag contained 11.4% of copper. The recovery process included two stages; the first stage is leaching using diluted sulfuric acid. The most important variables that effect on the leaching process was studied, such as acid concentration, hydrogen peroxide adding, particle size, liquid to solid, stirring speed and leaching time by changing the condition and the stabilizing of other factors at room temperature.               The second stage is precipitation of copper from leaching solution by zinc powder with different weights and times, at room temperature and 1.5 PH value. The results of the first stage manifested that about 99.7% of the copper have been dissolved at the following operational conditions: 50% acid concentration, 5 ml hydrogen peroxide adding, particle size (-75+53 micron, 1:10 liquid to solid, 500 rpm stirring speed and 25 min of leaching time. The highest percentage of copper precipitation in the second stage was 99.8% when added 3gm zinc powder at 20 min. The XRD result revealed that the predominant phase was pure copper. The results of EDS exhibited that a few percentage of oxygen appeared with copper powder. The final of copper recovery ratio was 99.3% with 99.2% purity.

QT Prolongation due to Graves’ Disease

Directory of Open Access Journals (Sweden)

Zain Kulairi

2017-01-01

Full Text Available Hyperthyroidism is a highly prevalent disease affecting over 4 million people in the US. The disease is associated with many cardiac complications including atrial fibrillation and also less commonly with ventricular tachycardia and fibrillation. Many cardiac pathologies have been extensively studied; however, the relationship between hyperthyroidism and rate of ventricular repolarization manifesting as a prolonged QTc interval is not well known. Prolonged QTc interval regardless of thyroid status is a risk factor for cardiovascular mortality and life-threatening ventricular arrhythmia. The mechanism regarding the prolongation of the QT interval in a hyperthyroid patient has not been extensively investigated although its clinical implications are relevant. Herein, we describe a case of prolonged QTc in a patient who presented with signs of hyperthyroidism that was corrected with return to euthyroid status.

Copper exposure induces toxicity to the antioxidant system via the destruction of Nrf2/ARE signaling and caspase-3-regulated DNA damage in fish muscle: Amelioration by myo-inositol

International Nuclear Information System (INIS)

Jiang, Wei-Dan; Liu, Yang; Jiang, Jun; Wu, Pei; Feng, Lin; Zhou, Xiao-Qiu

2015-01-01

Highlights: • Cu stress decreased fish muscle CuZnSOD, GPx1a, GPx1b and PKCδ mRNA levels. • Cu stress caused fish muscle lower nuclear Nrf2 levels and poor ARE binding ability. • Cu stress induced caspase-3 signaling-modulated DNA fragmentation in fish muscle. • Pre-treatment with MI prevented fish muscle from Cu-induced oxidative damages. - Abstract: The muscle is the main portion of fish that is consumed by humans. Copper (Cu) can induce oxidative damage in fish muscle. However, the effects of Cu exposure on the muscle antioxidant system and molecular patterns and preventive measures against these effects remain unclear. In this study, ROS production, enzymatic and mRNA levels of antioxidant enzymes and NF-E2-related factor 2 (Nrf2) signaling-related molecules, antioxidant response element (ARE) binding ability, DNA fragmentation and caspase-3 activities were analyzed in fish muscle following Cu exposure or myo-inositol (MI) pre-administration. The results indicated that contamination due to copper exposure caused an approximately three-fold increase in ROS production, induced lipid peroxidation and protein oxidation, and resulted in depletion of the glutathione (GSH) content of fish muscle. Moreover, Cu exposure caused decreases in the activities of total superoxide dismutase (T-SOD), CuZnSOD, and glutathione peroxidase (GPx) that were accompanied by decreases in CuZnSOD, GPx1a, GPx1b and signaling factor protein kinase C delta mRNA levels. The decreases in the antioxidant enzyme gene mRNA levels were confirmed to be partly due to the reduced nuclear Nrf2 protein levels, poor ARE binding ability and increased caspase-3 signaling-modulated DNA fragmentation in the fish muscle. Interestingly, MI pre-treatment prevented fish muscle from Cu-induced oxidative damages mainly through increasing the GSH content, and increasing the CuZnSOD and GPx activities and corresponding mRNA levels and ARE binding ability. Taken together, our results show for the first

Copper exposure induces toxicity to the antioxidant system via the destruction of Nrf2/ARE signaling and caspase-3-regulated DNA damage in fish muscle: Amelioration by myo-inositol

Energy Technology Data Exchange (ETDEWEB)

Jiang, Wei-Dan; Liu, Yang [Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Jiang, Jun [Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Wu, Pei [Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Feng, Lin, E-mail: fenglin@sicau.edu.cn [Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Zhou, Xiao-Qiu, E-mail: zhouxq@sicau.edu.cn [Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, Sichuan (China); Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu 611130, Sichuan (China)

2015-02-15

Highlights: • Cu stress decreased fish muscle CuZnSOD, GPx1a, GPx1b and PKCδ mRNA levels. • Cu stress caused fish muscle lower nuclear Nrf2 levels and poor ARE binding ability. • Cu stress induced caspase-3 signaling-modulated DNA fragmentation in fish muscle. • Pre-treatment with MI prevented fish muscle from Cu-induced oxidative damages. - Abstract: The muscle is the main portion of fish that is consumed by humans. Copper (Cu) can induce oxidative damage in fish muscle. However, the effects of Cu exposure on the muscle antioxidant system and molecular patterns and preventive measures against these effects remain unclear. In this study, ROS production, enzymatic and mRNA levels of antioxidant enzymes and NF-E2-related factor 2 (Nrf2) signaling-related molecules, antioxidant response element (ARE) binding ability, DNA fragmentation and caspase-3 activities were analyzed in fish muscle following Cu exposure or myo-inositol (MI) pre-administration. The results indicated that contamination due to copper exposure caused an approximately three-fold increase in ROS production, induced lipid peroxidation and protein oxidation, and resulted in depletion of the glutathione (GSH) content of fish muscle. Moreover, Cu exposure caused decreases in the activities of total superoxide dismutase (T-SOD), CuZnSOD, and glutathione peroxidase (GPx) that were accompanied by decreases in CuZnSOD, GPx1a, GPx1b and signaling factor protein kinase C delta mRNA levels. The decreases in the antioxidant enzyme gene mRNA levels were confirmed to be partly due to the reduced nuclear Nrf2 protein levels, poor ARE binding ability and increased caspase-3 signaling-modulated DNA fragmentation in the fish muscle. Interestingly, MI pre-treatment prevented fish muscle from Cu-induced oxidative damages mainly through increasing the GSH content, and increasing the CuZnSOD and GPx activities and corresponding mRNA levels and ARE binding ability. Taken together, our results show for the first

Effects of stimulation of copper bioleaching on microbial community in vineyard soil and copper mining waste.

Science.gov (United States)

Andreazza, Robson; Okeke, Benedict C; Pieniz, Simone; Bortolon, Leandro; Lambais, Márcio R; Camargo, Flávio A O

2012-04-01

Long-term copper application in vineyards and copper mining activities cause heavy metal pollution sites. Such sites need remediation to protect soil and water quality. Bioremediation of contaminated areas through bioleaching can help to remove copper ions from the contaminated soils. Thus, the aim of this work was to evaluate the effects of different treatments for copper bioleaching in two diverse copper-contaminated soils (a 40-year-old vineyard and a copper mining waste) and to evaluate the effect on microbial community by applying denaturing gradient gel electrophoresis (DGGE) of 16S ribosomal DNA amplicons and DNA sequence analysis. Several treatments with HCl, H(2)SO(4), and FeSO(4) were evaluated by stimulation of bioleaching of copper in the soils. Treatments and extractions using FeSO(4) and H(2)SO(4) mixture at 30°C displayed more copper leaching than extractions with deionized water at room temperature. Treatment with H(2)SO(4) supported bioleaching of as much as 120 mg kg(-1) of copper from vineyard soil after 115 days of incubation. DGGE analysis of the treatments revealed that some treatments caused greater diversity of microorganisms in the vineyard soil compared to the copper mining waste. Nucleotide Blast of PCR-amplified fragments of 16S rRNA gene bands from DGGE indicated the presence of Rhodobacter sp., Silicibacter sp., Bacillus sp., Paracoccus sp., Pediococcus sp., a Myxococcales, Clostridium sp., Thiomonas sp., a firmicute, Caulobacter vibrioides, Serratia sp., and an actinomycetales in vineyard soil. Contrarily, Sphingomonas was the predominant genus in copper mining waste in most treatments. Paracoccus sp. and Enterobacter sp. were also identified from DGGE bands of the copper mining waste. Paracoccus species is involved in the copper bioleaching by sulfur oxidation system, liberating the copper bounded in the soils and hence promoting copper bioremediation. Results indicate that stimulation of bioleaching with a combination of FeSO(4

Room-temperature X-ray diffraction studies of cisplatin and carboplatin binding to His15 of HEWL after prolonged chemical exposure

International Nuclear Information System (INIS)

Tanley, Simon W. M.; Schreurs, Antoine M. M.; Kroon-Batenburg, Loes M. J.; Helliwell, John R.

2012-01-01

Binding of cisplatin to His15 in hen egg-white lysozyme in aqueous media is observed after prolonged chemical exposure for 15 months, in contrast to the lack of binding that was observed after 4 d in a previous study. Binding of carboplatin is seen in greater detail in the case of room-temperature data collection compared with cryo data collection. The anticancer complexes cisplatin and carboplatin are known to bind to both the N δ and the N ∊ atoms of His15 of hen egg-white lysozyme (HEWL) in the presence of dimethyl sulfoxide (DMSO). However, neither binds in aqueous media after 4 d of crystallization and crystal growth, suggesting that DMSO facilitates cisplatin/carboplatin binding to the N atoms of His15 by an unknown mechanism. Crystals of HEWL cocrystallized with cisplatin in both aqueous and DMSO media, of HEWL cocrystallized with carboplatin in DMSO medium and of HEWL cocrystallized with cisplatin and N-acetylglucosamine (NAG) in DMSO medium were stored for between seven and 15 months. X-ray diffraction studies of these crystals were carried out on a Bruker APEX II home-source diffractometer at room temperature. Room-temperature X-ray diffraction data collection removed the need for cryoprotectants to be used, ruling out any effect that the cryoprotectants might have had on binding to the protein. Both cisplatin and carboplatin still bind to both the N δ and N ∊ atoms of His15 in DMSO media as expected, but more detail for the cyclobutanedicarboxylate (CBDC) moiety of carboplatin was observed at the N ∊ binding site. However, two molecules of cisplatin were now observed to be bound to His15 in aqueous conditions. The platinum peak positions were identified using anomalous difference electron-density maps as a cross-check with F o − F c OMIT electron-density maps. The occupancies of each binding site were calculated using SHELXTL. These results show that over time cisplatin binds to both N atoms of His15 of HEWL in aqueous media, whereas this

Exhaustion from prolonged gambling

Directory of Open Access Journals (Sweden)

Fatimah Lateef

2013-01-01

Full Text Available Complaints of fatigue and physical exhaustion are frequently seen in the acute medical setting, especially amongst athletes, army recruits and persons involved in strenuous and exertional physical activities. Stress-induced exhaustion, on the other hand, is less often seen, but can present with very similar symptoms to physical exhaustion. Recently, three patients were seen at the Department of Emergency Medicine, presenting with exhaustion from prolonged involvement in gambling activities. The cases serve to highlight some of the physical consequences of prolonged gambling.

Current trends in copper theft prevention

Energy Technology Data Exchange (ETDEWEB)

Mastrofrancesco, A. [Electrical Safety Authority, ON (Canada)

2009-07-01

Copper is used in electrical wiring, water and gas piping, currency, and in household items. An increase in the price and demand for copper has made copper theft a profitable venture for some thieves. Copper consumed in North America is typically supplied by recycling. Scrap dealers may pay near-market prices for pure copper wires. However, copper theft poses a serious threat to the safety of utility workers and the public. Power outages caused by copper theft are now affecting grid reliability. This paper examined technologies and techniques used to prevent copper theft as part of a security strategy for utilities. Attempts to steal copper can leave utility substations unsecured and accessible to children. The theft of neutral grounds will cause the local distribution company (LDC) to malfunction and may cause power surges in homes as well as appliance fires. Utilities are now looking at using a hybrid steel and copper alternative to prevent copper theft. Asset identification techniques are also being used to identify the original owners of the copper and more easily prosecute thieves. Automated monitoring techniques are also being used to increase substation security. Utilities are also partnering with law enforcement agencies and pressuring governments to require scrap dealers to record who they buy from. It was concluded that strategies to prevent copper theft should be considered as part of an overall security strategy for utilities. tabs., figs.

Copper Recovery from Yulong Complex Copper Oxide Ore by Flotation and Magnetic Separation

Science.gov (United States)

Han, Junwei; Xiao, Jun; Qin, Wenqing; Chen, Daixiong; Liu, Wei

2017-09-01

A combined process of flotation and high-gradient magnetic separation was proposed to utilize Yulong complex copper oxide ore. The effects of particle size, activators, Na2S dosage, LA (a mixture of ammonium sulfate and ethylenediamine) dosage, activating time, collectors, COC (a combination collector of modified hydroxyl oxime acid and xanthate) dosage, and magnetic intensity on the copper recovery were investigated. The results showed that 74.08% Cu was recovered by flotation, while the average grade of the copper concentrates was 21.68%. Another 17.34% Cu was further recovered from the flotation tailing by magnetic separation at 0.8 T. The cumulative recovery of copper reached 91.42%. The modifier LA played a positive role in facilitating the sulfidation of copper oxide with Na2S, and the combined collector COC was better than other collectors for the copper flotation. This technology has been successfully applied to industrial production, and the results are consistent with the laboratory data.

Preparation of graphite dispersed copper composite on copper plate with CO2 laser

Science.gov (United States)

Yokoyama, S.; Ishikawa, Y.; Muizz, M. N. A.; Hisyamudin, M. N. N.; Nishiyama, K.; Sasano, J.; Izaki, M.

2018-01-01

It was tried in this work to prepare the graphite dispersed copper composite locally on a copper plate with a CO2 laser. The objectives of this study were to clear whether copper graphite composite was prepared on a copper plate and how the composite was prepared. The carbon content at the laser spot decreased with the laser irradiation time. This mainly resulted from the elimination by the laser trapping. The carbon content at the outside of the laser spot increased with time. Both the laser ablation and the laser trapping did not act on the graphite particles at the outside of the laser spot. Because the copper at the outside of the laser spot melted by the heat conduction from the laser spot, the particles were fixed by the wetting. However, the graphite particles were half-floated on the copper plate. The Vickers hardness decreased with an increase with laser irradiation time because of annealing.

Optical and infrared spectroscopic studies of chemical sensing by copper phthalocyanine thin films

International Nuclear Information System (INIS)

Singh, Sukhwinder; Tripathi, S.K.; Saini, G.S.S.

2008-01-01

Thin films of copper phthalocyanine have been deposited on KBr and glass substrates by thermal evaporation method and characterized by the X-ray diffraction and optical absorption techniques. The observed X-ray pattern suggests the presence of α crystalline phase of copper phthalocyanine in the as-deposited thin films. Infrared spectra of thin films on the KBr pallet before and after exposure to the vapours of ammonia and methanol have been recorded in the wavenumber region of 400-1650 cm -1 . The observed infrared bands also confirm the α crystalline phase. On exposure, change in the intensity of some bands is observed. A new band at 1385 cm -1 , forbidden under ideal D 4h point group symmetry, is also observed in the spectra of exposed thin films. These changes in the spectra are interpreted in terms of the lowering of molecular symmetry from D 4h to C 4v . Axial ligation of the vapour molecules on fifth coordination site of the metal ion is responsible for lowering of the molecular symmetry

Antimicrobial Properties of Copper Nanoparticles and Amino Acid Chelated Copper Nanoparticles Produced by Using a Soya Extract

Science.gov (United States)

DeAlba-Montero, I.; Morales-Sánchez, Elpidio; Araujo-Martínez, Rene

2017-01-01

This paper reports a comparison of the antibacterial properties of copper-amino acids chelates and copper nanoparticles against Escherichia coli, Staphylococcus aureus, and Enterococcus faecalis. These copper-amino acids chelates were synthesized by using a soybean aqueous extract and copper nanoparticles were produced using as a starting material the copper-amino acids chelates species. The antibacterial activity of the samples was evaluated by using the standard microdilution method (CLSI M100-S25 January 2015). In the antibacterial activity assays copper ions and copper-EDTA chelates were included as references, so that copper-amino acids chelates can be particularly suitable for acting as an antibacterial agent, so they are excellent candidates for specific applications. Additionally, to confirm the antimicrobial mechanism on bacterial cells, MTT assay (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) was carried out. A significant enhanced antimicrobial activity and a specific strain were found for copper chelates over E. faecalis. Its results would eventually lead to better utilization of copper-amino acids chelate for specific application where copper nanoparticles can be not used. PMID:28286459

Specific features of the hemorrhagic syndrome manifestation under chronic, prolonged and acute irradiation

International Nuclear Information System (INIS)

Arlashchenko, N.I.; Gorlov, V.G.; Maksimova, E.N.

1978-01-01

To make the hemorrhagic syndrome manifest itself, two phenomena are necessary to coincide in time, they are: a fall in the elasticity of the vascular wall and reduction in the amount of thrombocytes in blood. Depending upon the radiation dose, the vascular wall and the thrombocytic function may be either simultaneously impaired after acute exposure) or dissociated (following prolonged irradiation). Chronic irradiation at small (subliminal) dose rates fails to induce hemorrhagic disorders and death of rats caused by pathologic hemophilia

Exposure of welders to fumes, Cr, Ni, Cu and gases in Dutch industries

NARCIS (Netherlands)

Wal, J.F. van der

1985-01-01

The exposure of welders in Dutch industries to total particulate, chromium, nickel and copper fume during the welding of unalloyed, stainless and high alloyed steels has been investigated. The exposure to the gases NO2, NO and ozone is also discussed. The results are presented in tables and graphs.

9. Nuclear power plant service life prolongation

International Nuclear Information System (INIS)

Evropin, S.V.

1998-01-01

The problem of prolongation of nuclear power plant service life duration is discussed. A schematic diagram of the program developed in the course of activities dealing with NPP service time prolongation is shown and analyzed in details. It is shown that the basic moment when determining the strategy for NPP service time prolongation is the positive confirmation of the agreement between the NPP safety provisions and modern safety requirements. The other very important aspect of the problem is engineering substantiation of the measures assuring the reactor operation prolongation. The conclusion is made that available methods of recovering reactor materials properties, main components repair and replacement, the modern techniques for nondestructive testing of metals and NPP pipelines, as well as the developed approaches to reactor facility safety improvements make the prolongation of the Russian NPP service lifetimes possible from engineering viewpoint and economically desirable

The Hyrkkoelae native copper mineralization as a natural analogue for copper canisters

International Nuclear Information System (INIS)

Marcos, N.

1996-10-01

The Hyrkkoelae U-Cu mineralization is located in southwestern Finland, near the Palmottu analogue site. The age of the mineralization is estimated to be between 1.8 and 1.7 Ga. Petrological and mineralogical studies have demonstrated that this mineralization has many geological features that parallel those of the sites being considered for nuclear waste disposal in Finland. A particular feature is the existence of native copper and copper sulfides in open fractures in the near-surface zone. This allows us to study the native copper corrosion process in analogous conditions as expected to dominate in the nuclear fuel waste repository. The occurrence of uranyl compounds at these fractures permits also considerations about the sorption properties of the engineered barrier material (metallic copper) and its corrosion products. From the study of mineral assemblages or paragenesis, it appears that the formation of copper sulfide (djurleite, Cu 1.934 ) after native copper (Cu 0 ) under anoxic (reducing) conditions is enhanced by the availability of dissolved HS - in the groundwater circulating in open fractures in the near-surface zone. The minimum concentration of HS - in the groundwater is estimated to be of the order of 10 -5 M (∼ 10 -4 g/l) and the minimum pH value not lower than about 7.8 as indicated by the presence of calcite crystals in the same fracture. The present study is the first one that has been performed on findings of native copper in reducing, neutral to slightly alkaline groundwaters. Thus, the data obtained is of most relevance in improving models of anoxic corrosion of copper canisters. (orig.)