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Sample records for sodium selenite nanoparticles

  1. Silver Nanoparticle Exposure Induced Mitochondrial Stress, Caspase-3 Activation and Cell Death: Amelioration by Sodium Selenite

    PubMed Central

    Ma, Wanrui; Jing, Li; Valladares, Alexandra; Mehta, Suresh L.; Wang, Zhizhong; Li, P. Andy; Bang, John J.

    2015-01-01

    Silver nanoparticles (AgNP), one of the most commonly used engineered nanomaterial for biomedical and industrial applications, has shown a toxic potential to our ecosystems and humans. In this study, murine hippocampal neuronal HT22 cells were used to delineate subcellular responses and mechanisms to AgNP by assessing the response levels of caspase-3, mitochondrial oxygen consumption, reactive oxygen species (ROS), and mitochondrial membrane potential in addition to cell viability testing. Selenium, an essential trace element that has been known to carry protecting property from heavy metals, was tested for its ameliorating potential in the cells exposed to AgNP. Results showed that AgNP reduced cell viability. The toxicity was associated with mitochondrial membrane depolarization, increased accumulation of ROS, elevated mitochondrial oxygen consumption, and caspase-3 activation. Treatment with sodium selenite reduced cell death, stabilized mitochondrial membrane potential and oxygen consumption rate, and prevented accumulation of ROS and activation of caspase-3. It is concluded that AgNP induces mitochondrial stress and treatment with selenite is capable of preventing the adverse effects of AgNP on the mitochondria. PMID:26157341

  2. Silver nanoparticle exposure induced mitochondrial stress, caspase-3 activation and cell death: amelioration by sodium selenite.

    PubMed

    Ma, Wanrui; Jing, Li; Valladares, Alexandra; Mehta, Suresh L; Wang, Zhizhong; Li, P Andy; Bang, John J

    2015-01-01

    Silver nanoparticles (AgNP), one of the most commonly used engineered nanomaterial for biomedical and industrial applications, has shown a toxic potential to our ecosystems and humans. In this study, murine hippocampal neuronal HT22 cells were used to delineate subcellular responses and mechanisms to AgNP by assessing the response levels of caspase-3, mitochondrial oxygen consumption, reactive oxygen species (ROS), and mitochondrial membrane potential in addition to cell viability testing. Selenium, an essential trace element that has been known to carry protecting property from heavy metals, was tested for its ameliorating potential in the cells exposed to AgNP. Results showed that AgNP reduced cell viability. The toxicity was associated with mitochondrial membrane depolarization, increased accumulation of ROS, elevated mitochondrial oxygen consumption, and caspase-3 activation. Treatment with sodium selenite reduced cell death, stabilized mitochondrial membrane potential and oxygen consumption rate, and prevented accumulation of ROS and activation of caspase-3. It is concluded that AgNP induces mitochondrial stress and treatment with selenite is capable of preventing the adverse effects of AgNP on the mitochondria. PMID:26157341

  3. Differential protein expression of Caco-2 cells treated with selenium nanoparticles compared with sodium selenite and selenomethionine

    NASA Astrophysics Data System (ADS)

    Fu, Linglin; Yan, Xuxia; Ruan, Xinming; Lin, Junda; Wang, Yanbo

    2014-10-01

    The study was designed to determine the differential protein expression of Caco-2 cells treated with different forms of selenium including sodium selenite, selenomethionine (Se-Met), and selenium nanoparticles (nano-Se). Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and mass spectrometry (MS) were used to identify the differentially expressed proteins. The results indicated that seven protein spots, ubiquitin-conjugating enzyme E2 (E2), glutathione synthetases (GS), triosephosphate isomerase (TSP), T-complex protein 1 subunit zeta (TCPZ), lamin-B1, heterogeneous nuclear ribonucleoprotein F (hnRNP F), and superoxide dismutase [Cu-Zn] (Cu, Zn-SOD) were significantly different among all the groups. According to the order of control, sodium selenite, Se-Met, and Nano-Se, the expression levels of two proteins (E2 and GS) increased and the other differential proteins were reverse. Except for E2, there were no significant differences in other protein expressions between the groups treated with nano-Se and Se-Met.

  4. Sodium selenite/selenium nanoparticles (SeNPs) protect cardiomyoblasts and zebrafish embryos against ethanol induced oxidative stress.

    PubMed

    Kalishwaralal, Kalimuthu; Jeyabharathi, Subhaschandrabose; Sundar, Krishnan; Muthukumaran, Azhaguchamy

    2015-10-01

    Alcoholic cardiomyopathy is the damage caused to the heart muscles due to high level of alcohol consumption resulting in enlargement and inflammation of the heart. Selenium is an important trace element that is beneficial to human health. Selenium protects the cells by preventing the formation of free radicals in the body. In the present study, protein mediated synthesis of SeNPs was investigated. Two different sizes of SeNPs were synthesized using BSA and keratin. The synthesized SeNPs were characterized by scanning electron microscopy (SEM) with elemental composition analysis Energy Dispersive X-ray spectroscopy(EDX) and X-ray diffraction (XRD). This study demonstrates the in vitro and in vivo antioxidative effects of sodium selenite and SeNPs. Further selenium and SeNPs were evaluated for their ability to protect against 1% ethanol induced oxidative stress in H9C2 cell line. The selenium and SeNPs were found to reduce the 1% ethanol-induced oxidative damage through scavenging intracellular reactive oxygen species. The selenium and SeNPs could also prevent pericardial edema induced ethanol treatment and reduced apoptosis and cell death in zebrafish embryos. The results indicate that selenium and SeNPs could potentially be used as an additive in alcoholic beverage industry to control the cardiomyopathy. PMID:26302921

  5. On The Protection by The Combination of CeO2 Nanoparticles and Sodium Selenite on Human Lymphocytes against Chlorpyrifos-Induced Apoptosis In Vitro

    PubMed Central

    Pedram, Sahar; Mohammadirad, Azadeh; Rezvanfar, Mohammad Amin; Navaei-Nigjeh, Mona; Baeeri, Maryam; Abdollahi, Mohammad

    2015-01-01

    Objective Chlorpyrifos (CP) as an organophosphorus pesticide is thought to induce oxidative stress in human cells via producing reactive oxygen species (ROS) that leads to the presence of pathologic conditions due to apoptosis along with acetylcholinesterase (AChE) inhibition.This study aimed to evaluate the apoptotic effects of CP and to assess the protective potential of CeO2nanoparticle (CNP) and sodium selenite (SSe) by measuring cascades of apoptosis, oxidative stress, inflammation, and AChE inhibition in human isolated lymphocytes. Materials and Methods In the present experimental study, we examined the anti-oxidative and AChE activating potential of CNP and SSe in CP-treated human lymphocytes. Therefore, the lymphocytes were isolated and exposed to CP, CP+CNP, CP+SSe, and CP+CNP+SSe after a three-day incubation. Then tumor necrosis factor-alpha (TNF-α) release, myeloperoxidase (MPO) activity, thiobarbituric acid-reactive substances (TBARS) levels as inflammatory/oxidative stress indices along with AChE activity were assessed. In addition, the apoptotic process was measured by flow cytometry. Results Results showed a significant reduction in the mortality rate, TNF-α, MPO activity, TBARS, and apoptosis rate in cells treated with CNP, SSe and their combination. Interestingly, both CNP and SSe were able to activate AChE which is inhibited by CP. The results supported the synergistic effect of CNP/SSe combination in the prevention of apoptosis along with oxidative stress and inflammatory cascade. Conclusion CP induces apoptosis in isolated human lymphocytes via oxidative stress and inflammatory mediators. CP firstly produces ROS, which leads to membrane phospholipid damage. The beneficial effects of CNP and SSe in reduction of CP-induced apoptosis and restoring AChE inhibition relate to their anti-oxidative potentials. PMID:26199915

  6. Sodium selenite and cancer related lymphedema: Biological and pharmacological effects.

    PubMed

    Pfister, Christina; Dawzcynski, Horst; Schingale, Franz-Josef

    2016-09-01

    A significant percentage of cancer patients develop secondary lymphedema after surgery or radiotherapy. The preferred treatment of secondary lymphedema is complex physical therapy. Pharmacotherapy, for example with diuretics, has received little attention, because they were not effective and only offered short-term solutions. Sodium selenite showed promise as a cost-effective, nontoxic anti-inflammatory agent. Treatment with sodium selenite lowers reactive oxygen species (ROS) production, causes a spontaneous reduction in lymphedema volume, increases the efficacy of physical therapy for lymphedema, and reduces the incidence of erysipelas infections in patients with chronic lymphedema. Besides biological effects in reducing excessive production of ROS, sodium selenite also displays various pharmacological effects. So far the exact mechanisms of these pharmacological effects are mostly unknown, but probably include inhibition of adhesion protein expression. PMID:27267968

  7. Comparative oral dose toxicokinetics of sodium selenite and selenomethionine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The toxicokinetics of selenium (Se) absorption, distribution, and elimination were determined in serum and whole blood of lambs that were orally dosed with various doses of Se as sodium selenite (inorganic Se) or selenomethionine (organic Se). Thirty-two lambs were randomly assigned to eight treatm...

  8. ULTRASTRUCTURAL EVALUATION OF THE RADIOPROTECTIVE EFFECT OF SODIUM SELENITE ON SUBMANDIBULAR GLANDS IN RATS

    PubMed Central

    Pontual, Maria Luiza dos Anjos; Tuji, Fabrício Mesquita; Barros, Silvana Pereira; Bóscolo, Frab Norberto; Novaes, Pedro Duarte; de Almeida, Solange Maria

    2007-01-01

    The aim of this study was to evaluate the radioprotector effect of sodium selenite on the ultrastructure of submandibular glands in rats. Fifty-seven male albino Wistar rats were randomized to 4 groups: control, irradiated, sodium selenite and irradiated/sodium selenite. The animals in the sodium selenite and irradiated/sodium selenite groups received intraperitoneal injections of sodium selenite (0.5 mg/kg body weight) 24 h before irradiation. The animals belonging to the irradiated and irradiated/sodium selenite groups were submitted to 15 Gy of gamma radiation in the head and neck region. The submandibular glands were removed at 4, 8, 12, 24, 48 and 72 h after irradiation. The ionizing radiation induced damage to the secretory cells, especially the serous cells, right from the first period. Vacuolization, lysis of cytoplasmic inclusions and nuclear alterations occurred. The sodium selenite group also presented cellular alterations in the study periods, but with less damage compared to that caused by radiation. There was greater similarity between the irradiated/sodium selenite group and the control group than with the other groups treated in all study periods. Despite the alterations observed in the sodium selenite group, sodium selenite presented a radioprotective action on the secretory cells of submandibular glands. PMID:19089124

  9. Effects of coadministered sodium selenite on short-term distribution on methyl mercury in the rat

    SciTech Connect

    Thomas, D.J.; Smith, J.C.

    1984-08-01

    Adult male Sprague-Dawley rats received iv injections of 1 ..mu..mole of methyl mercury/kg alone or coadministered with 5 ..mu..mole of sodium selenite/kg. Tissue concentrations of methyl mercury were determined at 5, 20, and 60 min after treatment. Selenite treatment produced a significant increase in cerebral methyl mercury concentrations and a significant decrease in kidney methyl mercury concentrations at all time points. The concentration of methyl mercury in liver was significantly increased by selenite coadministration at 5 and 20 min but at 60 min after injection the concentration was not significantly different from that found in rats receiving methyl mercury alone. Selenite treatment also significantly lowered blood methyl mercury concentrations at all time points. This decrease was associated with a significant decrease in the concentration of methyl mercury in erythrocytes at 5, 20, and 60 min. Plasma methyl mercury levels at 5 min postinjection were slightly higher in selenite-treated rats but were significantly lower in treated animals at 20 and 60 min. Treatment of rats with selenite did not specifically alter the extent of methyl mercury binding to glutathione in the 108,000 g supernatant of cerebrum of in erythrocyte hemolysates. In rats receiving either methyl mercury alone or with selenite, low-molecular-weight methyl mercury complexes could not be detected in plasma 5 min after iv injection.

  10. The effect of sodium selenite on lead induced cognitive dysfunction.

    PubMed

    Liu, Ming-Chao; Xu, Yan; Chen, Yao-Ming; Li, Juan; Zhao, Fang; Zheng, Gang; Jing, Jin-Fei; Ke, Tao; Chen, Jing-Yuan; Luo, Wen-Jing

    2013-05-01

    The effect of lead (Pb) on spatial memory and hippocampal long-term potentiation (LTP) as a key risk factor has been widely recognized and the oxidative damage has been proposed as a possible mechanism of lead neurotoxicity. Selenium (Se) is a nutritionally essential trace element with known antioxidant potential. In this study we investigated the effect and the underlying mechanisms of Se supplementary on Pb induced cognition and synaptic plasticity impairment. Lactating Sprague-Dawley rats (SD rats) were randomly divided to four groups: 0ppm lead acetate (Pb); 0ppm Pb and 0.2ppm sodium selenite (Se); 100ppm Pb; 100ppm Pb and 0.2ppm Se. Lactating rats were treated with or without Pb and/or Se throughout lactation until weaning. The levels of hippocampal LTP, the spatial memory, the apoptosis of hippocampal neurons, the levels of lactate dehydrogenase (LDH) release, and the serum level of superoxide dismutase (SOD) and malondialdehyde (MDA) were assayed. It had been observed that in Pb group the spatial memory, the induce level of LTP, the serum SOD level decreased, the LDH release level, the neurons apoptosis level, the serum MDA level increased, while in the Se supplements groups, the spatial memory, the induce level of LTP increased significantly. Compared with the Pb group, Se supplements shown down regulated the level of LDH, the neurons apoptosis and the serum MDA, and up regulated the level of serum SOD. We could draw the conclusion that Se supplements could alleviate toxic effect of lead on hippocampal LTP and spatial memory. The treated with selenium around 0.2ppm may protect against spatial memory dysfunction induced by lead exposure. PMID:23529067

  11. In Vitro Antibacterial Spectrum of Sodium Selenite against Selected Human Pathogenic Bacterial Strains

    PubMed Central

    Alam, Mohammad Firoz; Safhi, Mohammed M.; Moni, Sivakumar Sivagurunathan; Jabeen, Aamena

    2016-01-01

    The objective of this investigation was to predict the antibacterial properties of sodium selenite against selected human pathogens. A group of six human bacterial pathogens including Staphylococcus aureus, Streptococcus pyogenes, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella planticola were utilized for screening. The spectrum of activity was qualified based on zone of inhibition. Our study demonstrated that sodium selenite exhibits a strong spectrum of activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Klebsiella planticola. The spectrum of activity was compared with standard ciprofloxacin disc (5 μg/disc) and observed to have satisfactory effect. PMID:27066293

  12. SUBCHRONIC EFFECTS OF SODIUM SELENITE AND SELENOMETHIONINE ON SEVERAL IMMUNE-FUNCTIONS IN MALLARDS

    EPA Science Inventory

    The subchronic effects of selenomethionine (SeM) and sodium selenite (SeL) on several immunologic, hematologic, and serologic parameters in mallards were measured, using concentrations in drinking water of 0, 0.5, and 3.5 mg/L selenium (Se) as SeL and 2.2 mg/L (Se) as SeM. ycloph...

  13. Stabilization of membrane bound enzyme profiles by sodium selenite in N-nitrosodiethylamine induced and phenobarbital promoted hepatocarcinogenesis in rats.

    PubMed

    Thirunavukkarasu, C; Sakthisekaran, D

    2003-01-01

    As part of a substantial effort to curtail the adverse health effects posed by hepatoma, studies have been conducted to elucidate the possible mechanism for the anticarcinogenic action of sodium selenite against N-nitrosodiethylamine induced hepatocarcinogenesis. Sodium selenite administered through drinking water at a dose of 4 ppm before initiation, or during initiation and/or during the promotion period of carcinogenesis exerted an in vivo stabilizing effect on cell membranes in rat hepatoma. This was demonstrated in normal rats and in animals whose biomembranes were rendered fragile by induction of hepatoma with N-nitrosodiethylamine and subsequent treatment with sodium selenite. The obtained results have shown a significant decrease in the activities of Na(+)/K(+)-ATPases, Mg(2+)-ATPases and Ca(2+)-ATPases (P < 0.001) in erythrocyte membrane; hepatoma and surrounding liver tissue and also erythrocyte membrane are more susceptible to lysis in cancer-bearing animals. The selenite administration reversed these adverse changes to near normal in selenite-treated animals. Such stabilization of biomembranes by selenite has a beneficial effect in the treatment of hepatoma and other cancers involving abnormal fragility of cell membrane. Previous evidence from this laboratory with respect to the anticancer potency of selenite against N-nitrosodiethylamine-induced hepatoma together with the present results suggests that potentially effective therapeutic protection can be achieved by pre-supplementation of selenite. PMID:12818472

  14. Protection against ischemia/reperfusion–induced renal injury by co–treatment with erythropoietin and sodium selenite

    PubMed Central

    LIU, LU; LIU, CHAO; HOU, LAN; LV, JUAN; WU, FANG; YANG, XUEFEI; REN, SHUTING; JI, WENJUN; WANG, MENG; CHEN, LINA

    2015-01-01

    Ischemia/reperfusion injury (IRI) has lzong been an area of concern and focus of investigations. Erythropoietin (EPO) exhibits multiple protective effects, and selenium is an antioxidant trace element in the body, however, there have been no reports concerning the effects of EPO combined with sodium selenite on IRI. In the present study, a mouse model of renal IRI (RIRI) was pre–treated with EPO and sodium selenite to determine the most appropriate combination ratio of the two for further investigation. The results revealed that EPO and sodium selenite had synergistic protective effects in RIRI. EPO was identified as the predominant treatment component, with sodium selenite serving as an adjuvant, and combination treatment was markedly more effective, compared with treatment with either drug alone. The optimal ratio of treatment was 10:1 (10 IU EPO: 1 µg sodium selenite). The results indicated that RIRI markedly induced renal injury, as evidenced by elevated levels of blood urea nitrogen (BUN), as well as higher pathological scores, based on hematoxylin and eosin staining. Pre–treatment with EPO and sodium selenite significantly decreased serum expression levels of BUN and malonaldehyde, and increased the expression levels of superoxide dismutase, glutathione peroxidase and nitric oxide (NO), compared with the model group. Furthermore, co treatment with EPO and sodium selenite upregulated the protein expression levels of phosphatidylinositol 3 kinase (PI3K) in renal tissue samples. Together, the results suggested that co administration of EPO and sodium selenite effectively ameliorates IRI induced renal injury by reducing oxidative stress and activating the PI3K/NO signaling pathway. PMID:26647839

  15. Selenite-induced toxicity in cancer cells is mediated by metabolic generation of endogenous selenium nanoparticles.

    PubMed

    Bao, Peng; Chen, Zheng; Tai, Ren-Zhong; Shen, Han-Ming; Martin, Francis L; Zhu, Yong-Guan

    2015-02-01

    Selenite has been a touted cancer chemopreventative agent but generates conflicting outcomes. Multiple mechanisms of selenite cytotoxicity in cancer cells are thought to be induced by metabolites of selenite. We observed that intracellular metabolism of selenite generates endogenous selenium nanoparticles (SeNPs) in cancer cells. Critical proteins that bind with high affinity to elemental selenium during SeNPs self-assembly were identified through proteomics analysis; these include glycolytic enzymes, insoluble tubulin, and heat shock proteins 90 (HSP90). Sequestration of glycolytic enzymes by SeNPs dramatically inhibits ATP generation, which leads to functional and structural disruption of mitochondria. Transcriptome sequencing showed tremendous down-regulation of mitochondrial respiratory NADH dehydrogenase (complex I), cytochrome c oxidase (complex IV), and ATP synthase (complex V) in response to glycolysis-dependent mitochondrial dysfunction. Sequestration of insoluble tubulin led to microtubule depolymerization, altering microtubule dynamics. HSP90 sequestration led to degradation of its downstream effectors via autophagy, ultimately resulting in a cell-signaling switch to apoptosis. Additionally, the surface effects of SeNPs generated oxidative stress, thus contributing to selenite cytotoxicity. Herein, we reveal that the multiple mechanisms of selenite-induced cytotoxicity are caused by endogenous protein-assisted self-assembly of SeNPs and suggest that endogenous SeNPs could potentially be the primary cause of selenite-induced cytotoxicity. PMID:25567070

  16. Absorption, distribution, metabolism and excretion of selenium following oral administration of elemental selenium nanoparticles or selenite in rats.

    PubMed

    Loeschner, Katrin; Hadrup, Niels; Hansen, Marianne; Pereira, Sonia A; Gammelgaard, Bente; Møller, Laura Hyrup; Mortensen, Alicja; Lam, Henrik Rye; Larsen, Erik H

    2014-02-01

    A suspension of nanoparticles of BSA-stabilized red amorphous elemental selenium (Se) or an aqueous solution of sodium selenite was repeatedly administered by oral gavage for 28 days at 0.05 mg kg(-1) bw per day (low dose) or at 0.5 mg kg(-1) bw per day (high dose) as Se to female rats. Prior to administration, the size distribution of the Se nanoparticles was characterized by dynamic light scattering and transmission electron microscopy, which showed that the particles' mean diameter was 19 nm and ranged in size from 10 to 80 nm. Following administration of the high dose of Se nanoparticles or selenite the concentration of Se was determined by ICP-MS in the liver, kidney, urine, feces, stomach, lungs, and plasma at the μg g(-1) level and in brain and muscle tissue at the sub-μg g(-1) level. In order to test if any elemental Se was present in the liver, kidney or feces, an in situ derivatization selective to elemental Se was performed by treatment with sulfite, which resulted in formation of the selenosulfate anion. This Se species was selectively and quantitatively determined by anion exchange HPLC and ICP-MS detection. The results showed that elemental Se was present in the livers, kidneys and feces of animals exposed to low and high doses of elemental Se nanoparticles or to selenite, and was also detected in the same samples from control animals. The fraction of Se present as elemental Se in livers and kidneys from the high dose animals was significantly larger than the similar fraction in samples from the low dose animals or from the controls. This suggested that the natural metabolic pathways of Se were exhausted when given the high dose of elemental Se or selenite resulting in a non-metabolized pool of elemental Se. Both dosage forms of Se were bioavailable as demonstrated by the blood biomarker selenoprotein P, which was equally up-regulated in the high-dose animals for both dosage forms of Se. Finally, the excretion of Se in urine and its occurrence as Se

  17. Sodium Selenite Acts as an Otoprotectant against Neomycin-Induced Hair Cell Damage in a Zebrafish Model

    PubMed Central

    Chang, Jiwon; Choi, June; Rah, Yoon Chan; Yoo, Myung Hoon; Oh, Kyoung Ho; Im, Gi Jung; Lee, Seung Hoon; Kwon, Soon Young; Park, Hae-Chul; Chae, Sung Won; Jung, Hak Hyun

    2016-01-01

    Sodium selenite is a trace element essential for many physiological functions in the body. It is involved in various biological processes; it acts as a cofactor for antioxidant enzymes that protect against free radicals and is reported to limit metal-mediated oxidative DNA damage. In the present study, we investigated the effect of sodium selenite on neomycin ototoxicity in wild-type and transgenic zebrafish (Brn3C: EGFP). Five or six days post-fertilization, zebrafish larvae were co-exposed to 125 μM neomycin and various concentrations (10 μM, 100 μM, 250 μM, and 500 μM) of sodium selenite for 1 h. Hair cells within neuromasts of the supraorbital (SO1 and SO2), otic (O1), and occipital (OC1) lateral lines were analyzed by fluorescence microscopy (n = 10 fish per treatment). Hair cell survival was estimated as the ratio of the hair cell numbers in each group compared to those of the control group that were not exposed to neomycin. Apoptosis and hair cell damage of neuromasts were evaluated using the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL) assay and 2-[4-(dimethylamino) styryl]-N-ethylpyridinium iodide (DASPEI) assay, respectively. Ultrastructural changes were evaluated using scanning electron microscopy and transmission electron microscopy. Neuromast hair cells were preserved in zebrafish exposed to 125 μM neomycin and 500 μM sodium selenite for 1 h. Sodium selenite protected against neomycin-induced hair cell loss of neuromasts, reduced apoptosis, and prevented zebrafish ultrastructural changes. We propose that sodium selenite protects against neomycin-induced hair cell damage by inhibiting apoptosis, decreasing the disarray of stereocilia, and preventing ultrastructural changes in the neuromast hair cells of the zebrafish. PMID:26974429

  18. Reduction of selenite by Azospirillum brasilense with the formation of selenium nanoparticles.

    PubMed

    Tugarova, Anna V; Vetchinkina, Elena P; Loshchinina, Ekaterina A; Burov, Andrei M; Nikitina, Valentina E; Kamnev, Alexander A

    2014-10-01

    The ability to reduce selenite (SeO(3)(2-)) ions with the formation of selenium nanoparticles was demonstrated in Azospirillum brasilense for the first time. The influence of selenite ions on the growth of A. brasilense Sp7 and Sp245, two widely studied wild-type strains, was investigated. Growth of cultures on both liquid and solid (2 % agar) media in the presence of SeO(3)(2-) was found to be accompanied by the appearance of the typical red colouration. By means of transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS) and X-ray fluorescence analysis (XFA), intracellular accumulation of elementary selenium in the form of nanoparticles (50 to 400 nm in diameter) was demonstrated for both strains. The proposed mechanism of selenite-to-selenium (0) reduction could involve SeO(3)(2-) in the denitrification process, which has been well studied in azospirilla, rather than a selenite detoxification strategy. The results obtained point to the possibility of using Azospirillum strains as endophytic or rhizospheric bacteria to assist phytoremediation of, and cereal cultivation on, selenium-contaminated soils. The ability of A. brasilense to synthesise selenium nanoparticles may be of interest to nanobiotechnology for "green synthesis" of bioavailable amorphous red selenium nanostructures. PMID:24863127

  19. Survival of Tribolium confusum (Coleoptera: Tenebrionidae) in basal-casein medium supplemented with sodium selenite

    SciTech Connect

    Hogan, G.R.; Cole, B.S. )

    1988-01-01

    The trace substance selenium is known to influence several systems exhibiting a high rate of cellular proliferation. Data are reported on survival patterns and times in various developmental stages of Tribolium confusum Duval reared in a defined medium supplemented with sodium selenite. Insects reared from eggs hatching in a selenium medium (Se medium) show a prolonged time in the larval period and marked larval mortality compared with those reared on unsupplemented medium. Adults emerging in an Se medium show reduced survival compared with adults transferred to such medium 1 wk after emergence. Larval survival patterns mimic those of the adult, whereby younger larvae that are transferred to Se medium appear to be more sensitive than those exposed to Se medium later in the larval stage. Transfer of Se medium-reared adults to unsupplemented medium as pupae has a beneficial effect on survival compared with adults that emerged in Se medium 1 wk before transfer.

  20. [Anabolic effects of sodium selenite, vitamin E and retabolil in experimental hypotrophy induced by a pesticide].

    PubMed

    Makhmudov, T M; Makhsumov, M N; Mazgutov, V Z

    1989-01-01

    Forty Chinchilla rabbits of both sexes were examined for changes in some parameters of protein, lipid and trace elements metabolism (total protein, protein fractions, urea, residual nitrogen in blood serum, lipids, total cholesterol, free cholesterol, diglycerides, phospholipids, triglycerides, free fatty acids and the trace elements selenium, iron, zinc and so forth in the liver) during the animals' poisoning with the defoliant magnesium chlorate. A study was made of the effect on these changes of the administration for 3 weeks of sodium selenite (15 micrograms/kg), vitamin E (25 mg/kg) and retabolil (2 mg/kg once a week). It has been established that the combined administration of these agents removes and prevents the changes in protein, lipid and trace elements (hypoproteinemia, dysproteinemia and impairment of the nitrous balance) and lipid metabolism because of the animals' poisoning with magnesium chlorate. PMID:2552678

  1. Protective Roles of Sodium Selenite against Aflatoxin B1-Induced Apoptosis of Jejunum in Broilers

    PubMed Central

    Peng, Xi; Zhang, Shengqiang; Fang, Jing; Cui, Hengmin; Zuo, Zhicai; Deng, Junliang

    2014-01-01

    The effects of aflatoxin B1 (AFB1) exposure and sodium selenite supplementation on cell apoptosis of jejunum in broilers were studied. A total of 240 one-day-old male AA broilers were randomly assigned four dietary treatments containing 0 mg/kg of AFB1 (control), 0.3 mg/kg AFB1 (AFB1), 0.4 mg/kg supplement Se (+ Se) and 0.3 mg/kg AFB1 + 0.4 mg/kg supplement Se (AFB1 + Se), respectively. Compared with the control broilers, the number of apoptotic cells, the expression of Bax and Caspase-3 mRNA were significantly increased, while the expression of Bcl-2 mRNA and the Bcl-2/Bax ratio were significantly decreased in AFB1 broilers. The number of apoptotic cells and the expression of Caspase-3 mRNA in AFB1 + Se broilers were significantly higher than those in the control broilers, but significantly lower than those in AFB1 broilers. There were no significant changes in the expression of Bax mRNA between AFB1 + Se and control broilers; the expression of Bcl-2 mRNA and the Bcl-2/Bax ratio in AFB1 + Se broilers were significantly lower than those in the control broilers, but significantly higher than those in AFB1 broilers. In conclusion, 0.3 mg/kg AFB1 in the diet can increase cell apoptosis, decrease Bcl-2 mRNA expression, and increase of Bax and Caspase-3 mRNA expression in broiler’s jejunum. However, supplementation of dietary sodium selenite at the concentration of 0.4 mg/kg Se may ameliorate AFB1-induced apoptosis by increasing Bcl-2 mRNA expression, and decreasing Bax and Caspase-3 mRNA expression. PMID:25526081

  2. Protective Effects of Sodium Selenite against Aflatoxin B1-Induced Oxidative Stress and Apoptosis in Broiler Spleen

    PubMed Central

    Wang, Fengyuan; Shu, Gang; Peng, Xi; Fang, Jing; Chen, Kejie; Cui, Hengmin; Chen, Zhengli; Zuo, Zhicai; Deng, Junliang; Geng, Yi; Lai, Weimin

    2013-01-01

    The aim of this study was to investigate the possible protective role of sodium selenite on aflatoxin B1-induced oxidative stress and apoptosis in spleen of broilers. Two hundred one-day-old male broilers, divided into five groups, were fed with basal diet (control group), 0.3 mg/kg AFB1 (AFB1 group), 0.3 mg/kg AFB1 + 0.2 mg/kg Se (+Se group I), 0.3 mg/kg AFB1 + 0.4 mg/kg Se (+Se group II) and 0.3 mg/kg AFB1 + 0.6 mg/kg Se (+Se group III), respectively. According to biochemical assays, AFB1 significantly decreased the activities of glutathione peroxidase, total superoxide dismutase, glutathione reductase, catalase and the level of glutathione hormone, while it increased the level of malondialdehyde. Moreover, AFB1 increased the percentage of apoptosis cells by flow cytometry and the occurrence of apoptotic cells by TUNEL assay. Simultaneous supplementation with sodium selenite restored these parameters to be close to those in control group. In conclusion, sodium selenite exhibited protective effects on AFB1-induced splenic toxicity in broilers by inhibiting oxidative stress and excessive apoptosis. PMID:23839060

  3. Adjuvant selenium supplementation in the form of sodium selenite in postoperative critically ill patients with severe sepsis

    PubMed Central

    2014-01-01

    Introduction Plasma selenium (Se) concentrations are reduced in critically ill surgical patients, and lower plasma Se concentrations are associated with worse outcomes. We investigated whether adjuvant Se supplementation in the form of sodium selenite could improve outcomes in surgical patients with sepsis. Methods In this retrospective study, all adult patients admitted to a 50-bed surgical ICU with severe sepsis between January 2004 and April 2010 were included and analysed according to whether they had received adjuvant Se supplementation, which was given at the discretion of the attending physician. When prescribed, Se was administered in the form of sodium selenite pentahydrate (Na2SeO3∙5H2O), in which 100 μg of Se corresponds to 333 μg of sodium selenite. A bolus of sodium selenite corresponding to 1,000 μg of Se was injected intravenously through a central venous line for 30 minutes, followed by infusion of 1,000 μg/day for 24 hours for 14 days until ICU discharge or death. We performed logistic regression analysis to investigate the impact of adjuvant Se supplementation on hospital mortality. Results Adjuvant Se was administered to 413 (39.7%) of the 1,047 patients admitted with severe sepsis. Age and sex were similar between patients who received adjuvant Se and those who did not. Compared with patients who did not receive adjuvant Se supplementation, patients who did had higher scores on the Simplified Acute Physiology Score II, a greater prevalence of cancer upon admission to the ICU and were more commonly admitted after abdominal surgery. Compared with patients who did not receive adjuvant Se, patients who did had higher hospital mortality rates (46% versus 39.1%; P = 0.027), and longer median (interquartile range (IQR)) ICU stays (15 days (6 to 24) versus 11 days (4 to 24); P = 0.01) and hospital lengths of stay (33 days (21 to 52) versus 28 days (17 to 46); P = 0.001). In multivariable analysis, adjuvant Se supplementation

  4. Pharmacokinetics and Toxicity of Sodium Selenite in the Treatment of Patients with Carcinoma in a Phase I Clinical Trial: The SECAR Study

    PubMed Central

    Brodin, Ola; Eksborg, Staffan; Wallenberg, Marita; Asker-Hagelberg, Charlotte; Larsen, Erik H.; Mohlkert, Dag; Lenneby-Helleday, Clara; Jacobsson, Hans; Linder, Stig; Misra, Sougat; Björnstedt, Mikael

    2015-01-01

    Background: Sodium selenite at high dose exerts antitumor effects and increases efficacy of cytostatic drugs in multiple preclinical malignancy models. We assessed the safety and efficacy of intravenous administered sodium selenite in cancer patients’ refractory to cytostatic drugs in a phase I trial. Patients received first line of chemotherapy following selenite treatment to investigate altered sensitivity to these drugs and preliminary assessment of any clinical benefits. Materials and Methods: Thirty-four patients with different therapy resistant tumors received iv sodium selenite daily for consecutive five days either for two weeks or four weeks. Each cohort consisted of at least three patients who received the same daily dose of selenite throughout the whole treatment. If 0/3 patients had dose-limiting toxicities (DLTs), the study proceeded to the next dose-level. If 2/3 had DLT, the dose was considered too high and if 1/3 had DLT, three more patients were included. Dose-escalation continued until the maximum tolerated dose (MTD) was reached. MTD was defined as the highest dose-level on which 0/3 or 1/6 patients experienced DLT. The primary endpoint was safety, dose-limiting toxic effects and the MTD of sodium selenite. The secondary endpoint was primary response evaluation. Results and Conclusion: MTD was defined as 10.2 mg/m2, with a calculated median plasma half-life of 18.25 h. The maximum plasma concentration of selenium from a single dose of selenite increased in a nonlinear pattern. The most common adverse events were fatigue, nausea, and cramps in fingers and legs. DLTs were acute, of short duration and reversible. Biomarkers for organ functions indicated no major systemic toxicity. In conclusion, sodium selenite is safe and tolerable when administered up to 10.2 mg/m2 under current protocol. Further development of the study is underway to determine if prolonged infusions might be a more effective treatment strategy. PMID:26102212

  5. Switching to instant black coffee modulates sodium selenite-induced cataract in rats

    PubMed Central

    El Okda, E. A.; Mohamed, M. M.; Shaheed, E. B.; Abdel-Moemin, A. R.

    2016-01-01

    The influence of daily consumption of some common beverages on the development of cataract in rats was investigated. Total phenol content was determined in the beverages and an oral standardized dose of total phenols from each beverage was given to the treated rats. Weaned male albino rats were used and divided into five groups (n=7). Rats were fed Ain 93G and administered the standardized dose of instant coffee, black tea and hibiscus beverages for 30 days. On day 14 all rats were injected with a single dose of sodium selenite (Na2SeO3) 15 µmol/kg bodyweight, except the control groups NC (negative control, did not receive Na2SeO3) and PC (positive control, was already injected on day 1 of the study). The rats were continued on Ain 93G and the standardized dose for another 16 days. Positive control rats were used. Total phenols were 210, 40, and 44 mg/g dry weight gallic acid equivalent in black coffee, black tea, and hibiscus, respectively. Decreased levels (statistically significant P<0.05) of malondialdehyde, total nitric oxide, Ca-ATPase, tumor necrosis factor-α, interleukin-1β, superoxide dismutase, and conversely, increased levels (statistically significant P<0.05) of total protein, reduced glutathione, catalase were found in the lenses of the coffee group compared to PC. There are co-phenol substances in the instant black coffee that promoted coffee to be the most effective beverage. PMID:27158251

  6. Sodium selenite-induced hypothermia in mice: indirect evidence for a neural effect.

    PubMed

    Watanabe, C; Suzuki, T

    1986-12-01

    The effect of sodium selenite (SS) on the body temperature of adult male ICR mice was examined. SS (10-60 mumol/kg) administered subcutaneously resulted in a transient and dose-dependent hypothermia at ambient temperatures (Ta) of 20 and 30 degrees C. Reduced oxygen consumption accompanied the changes in body temperature. In addition, SS-treated mice exhibited transient cold-seeking behavior in the thermogradient. This SS-induced hypothermia was very similar to those induced by ethanol, tetrahydrocannabinol, triethyltin, sulfolane, and chlordimeform in that these all were transient, dependent on Ta, and not counteracted by behavioral thermoregulation. From these results, involvement of neural afferent or integral pathways is suggested. Further, acute mortality of SS-injected mice was enhanced with the elevation of Ta, as in the case of the chemicals mentioned above. Considering the diverse chemical and pharmacological properties of these chemicals, these results may suggest a possible interrelation between the hypothermic response and the modification of toxicity. PMID:3787631

  7. Switching to instant black coffee modulates sodium selenite-induced cataract in rats.

    PubMed

    El Okda, E A; Mohamed, M M; Shaheed, E B; Abdel-Moemin, A R

    2016-01-01

    The influence of daily consumption of some common beverages on the development of cataract in rats was investigated. Total phenol content was determined in the beverages and an oral standardized dose of total phenols from each beverage was given to the treated rats. Weaned male albino rats were used and divided into five groups (n=7). Rats were fed Ain 93G and administered the standardized dose of instant coffee, black tea and hibiscus beverages for 30 days. On day 14 all rats were injected with a single dose of sodium selenite (Na2SeO3) 15 µmol/kg bodyweight, except the control groups NC (negative control, did not receive Na2SeO3) and PC (positive control, was already injected on day 1 of the study). The rats were continued on Ain 93G and the standardized dose for another 16 days. Positive control rats were used. Total phenols were 210, 40, and 44 mg/g dry weight gallic acid equivalent in black coffee, black tea, and hibiscus, respectively. Decreased levels (statistically significant P<0.05) of malondialdehyde, total nitric oxide, Ca-ATPase, tumor necrosis factor-α, interleukin-1β, superoxide dismutase, and conversely, increased levels (statistically significant P<0.05) of total protein, reduced glutathione, catalase were found in the lenses of the coffee group compared to PC. There are co-phenol substances in the instant black coffee that promoted coffee to be the most effective beverage. PMID:27158251

  8. Low-temperature transformations of sodium sulfate and sodium selenite in the presence of pre-reduced palladium modifier in graphite furnaces for electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Volynsky, Anatoly B.; Stakheev, Alexandr Yu.; Telegina, Natalia S.; Senin, Valery G.; Kustov, Leonid M.; Wennrich, Rainer

    2001-08-01

    The low-temperature interaction (up to 550°C) of a pre-reduced palladium modifier with sodium sulfate and sodium selenite on the pyrolytic graphite platform was studied using X-ray photoelectron spectroscopy (XPS) and electron microprobe analysis. The equipment applied allowed the introduction of samples heated in an argon flow into the analytical chamber of the XPS spectrometer without contact with the air. Electron microprobe analysis showed that palladium and sulfur preferably occupy different areas on the platform surface. On the contrary, selenium from sodium selenite tends to occupy areas of the graphite surface covered with palladium. The most probable reason for this is the chemisorption of selenium (IV) on the palladium surface at the drying stage. No changes in the XPS spectra of metallic Pd and S 6+ were observed when Na 2SO 4 and Pd were heated together on the graphite platform in the range 100-550°C. The reduction of sodium selenite on the graphite surface already starts during drying. Pre-reduced palladium intensifies this process. The rate of the reduction is proportional to the amount of palladium, and in the presence of palladium at an atomic ratio of Pd/Se=7.5, the transformation of Se 4+ into Se 0 completes at 250°C.

  9. Sodium selenite supplementation does not fully restore oxidative stress-induced deiodinase dysfunction: Implications for the nonthyroidal illness syndrome

    PubMed Central

    Wajner, Simone Magagnin; Rohenkohl, Helena Cecin; Serrano, Tulio; Maia, Ana Luiza

    2015-01-01

    Nonthyroidal illness syndrome (NTIS) is marked by low T3 and high reverse T3 levels. The physiopathology is poorly understood but involves oxidative stress-induced disruption of the iodothyronine deiodinases, which activate or inactivate thyroid hormones. Selenium, an essential trace element, exerts antioxidant function mainly through the thioredoxin reductase (TRx) and glutathione peroxidase (GPx) redox-regulating systems. We evaluated the effect of sodium selenite on IL6-induced disruption on deiodinase function. Cell lines expressing endogenous deiodinases type 1(D1), 2(D2) or 3(D3) (HepG2, MSTO, and MCF-7 cells, respectively) were used in an intact cell model that mimics the deiodination process under physiological conditions of substrate and cofactor, in the presence or not of IL6, with or without selenite. Deiodinase activity was quantified by the amount of iodine-125 in the medium (D1 and D2) or by ion-exchange chromatography (D3). Oxidative stress was evaluated by measuring reactive species (RS), carbonyl content as well as enzymatic and non-enzymatic antioxidant defenses. Results: IL6 induced ROS and carbonyl content in all 3 cell lines (all P<0.001). Increased ROS was paralleled by D1 and D2-decreased T3-production (P<0.01) and increased D3-catalyzed T3-inactivation (P<0.001). Selenite decreases the IL6-induced ROS and carbonyl content, while enhances Gpx and Trx activities. Nevertheless, it failed on restoring D1 or D2 function and only attenuates D3 activation (P<0.05). In conclusion, although sodium selenite reduces IL6-induced redox imbalance it does not fully repair deiodinase function. These results shed light on NTIS physiopathology and might explain why low T3 levels are unaffected by selenium supplementation in sick patients. PMID:26402162

  10. Sodium Selenite Radiosensitizes Hormone-Refractory Prostate Cancer Xenograft Tumors but Not Intestinal Crypt Cells In Vivo

    SciTech Connect

    Tian Junqiang; Ning Shouchen; Knox, Susan J.

    2010-09-01

    Purpose: We have previously shown that sodium selenite (SSE) increases radiation-induced cell killing of human prostate carcinoma cells in vitro. In this study we further evaluated the in vivo radiosensitizing effect of SSE in prostate cancer xenograft tumors and normal radiosensitive intestinal crypt cells. Methods and Materials: Immunodeficient (SCID) mice with hormone-independent LAPC-4 (HI-LAPC-4) and PC-3 xenograft tumors (approximately 200 mm{sup 3}) were divided into four groups: control (untreated), radiation therapy (XRT, local irradiation), SSE (2 mg/kg, intraperitoneally, 3 times/week), and XRT plus SSE. The XRT was given at the beginning of the regimen as a single dose of 5 Gy for HI-LAPC-4 tumors and a single dose of 7 Gy followed by a fractional dose of 3 Gy/d for 5 days for PC-3 tumors. The tumor volume was measured 3 times per week. The radiosensitizing effect of SSE on normal intestinal epithelial cells was assessed by use of a crypt cell microcolony assay. Results: In the efficacy study, SSE alone significantly inhibited the tumor growth in HI-LAPC-4 tumors but not PC-3 tumors. Sodium selenite significantly enhanced the XRT-induced tumor growth inhibition in both HI-LAPC-4 and PC-3 tumors. In the toxicity study, SSE did not affect the intestinal crypt cell survival either alone or in combination with XRT. Conclusions: Sodium selenite significantly enhances the effect of radiation on well-established hormone-independent prostate tumors and does not sensitize the intestinal epithelial cells to radiation. These results suggest that SSE may increase the therapeutic index of XRT for the treatment of prostate cancer.

  11. Biointeraction of sodium selenite and aflatoxin B/sub 1/ in the Mongolian gerbil

    SciTech Connect

    Lalor, J.H.; Llewellyn, G.C.

    1981-09-01

    The interaction of sodium selenite (Na/sub 2/SeO/sub 3/) and aflatoxin B/sub 1/ (AFB/sub 1/) was studied in 6-wk-old male Mongolian gerbils. Each of four groups of gerbils were fed one of the following diets during a 12-wk experimental period: control (commercial Chow), 5.0 ppm Na/sub 2/SeO/sub 3/, 12.8 ppm AFB/sub 1/, or 5.0 ppm Na/sub 2/SeO/sub 3/ + 12.8 ppm AFB/sub 1/. Animals receiving Na/sub 2/SeO/sub 3/ in the diet, alone and with AFB/sub 1/, had a significantly lower mean total weight gain during the experiment than did control animals. Animals receiving both compounds together displayed a very high level of physical activity compared to the three other groups. Blood analysis showed no change in total leukocytes, but the relative percentage of lymphocytes increased and the percentage of neutrophils decreased concurrently in the order: control < AFB/sub 1/ < Na/sub 2/SeO/sub 3/ + AFB/sub 1/ < Na/sub 2/SeO/sub 3/. A significant reduction in organ weight relative to body weight was observed in the liver, kidney, and lung of the animals fed AFB/sub 1/ alone but only in the liver of those fed both Na/sub 2/SeO/sub 3/ and AFB/sub 1/. No similar alterations were observed in the Na/sub 2/SeO/sub 3/ group. Histopathological examination revealed considerably less hepatic damage in animals fed Na/sub 2/SeO/sub 3/ with AFB/sub 1/ than in those receiving either compound alone. Renal and intestinal damage, however, was most severe in this double-treatment group. Hepatic protein analysis revealed two protein peaks in the Na/sub 2/SeO/sub 3/ + AFB/sub 1/ group that were absent in all other groups. It was concluded that these proteins may be selenoproteins directly or indirectly involved in the lower incidence of histopathological damage in this group.

  12. Effect of dietary fat on plasma glutathione peroxidase levels and intestinal absorption of /sup 75/Se-labeled sodium selenite in chicks

    SciTech Connect

    Mutanen, M.L.; Mykkaenen, H.M.

    1984-05-01

    The effect of dietary fat on the availability of selenium was investigated in chicks fed either 4 or 20% butter, olive oil, rape oil, corn oil or sunflower oil in the diet for 3 weeks after hatching. Plasma glutathione peroxidase (GSH-Px) activity was used as an indicator of the body selenium status. In addition, the intestinal absorption of sodium selenite (/sup 75/Se-labeled) was determined by using both the in vivo ligated loop procedure and oral administration of the isotope. The plasma GSH-Px levels increased with increasing proportion of the polyunsaturated fatty acids in the diet. Increasing the amount of fat from 4 to 20% significantly enhanced the GSH-Px activity in the groups receiving butter or olive oil, but had no effect in animals fed the unsaturated fats. The absorption of (/sup 75/Se)selenite from the ligated duodenal loops tended to be reduced in chicks fed corn oil or sunflower oil as compared to the animals receiving butter in their diet. On the other hand, the type of dietary fat did not appear to affect the absorption of the orally administered selenite. The present study demonstrates that the type of dietary fat can affect the plasma GSH-Px levels in chicks without altering the intestinal absorption of selenite. However, the results on the absorption of the intraduodenally injected sodium selenite suggest that dietary fat plays some role in the intestinal transport of selenium.

  13. The Combination of α-Tocopheryl Succinate and Sodium Selenite on Breast Cancer: A Merit or a Demerit?

    PubMed Central

    Badr, Doaa M.; Hafez, Hafez F.; Agha, Azza M.; Shouman, Samia A.

    2016-01-01

    α-Tocopheryl succinate (α-TOS), a mitochondria-targeting agent, induces apoptosis in malignant cells in vitro and in vivo. Selenite is a nutritional supplement that has been shown to stimulate apoptosis in cancer cells. This study was designed to investigate the cytotoxic effect of combined treatment of α-TOS and sodium selenite (SSe) in vitro and in vivo and to explore their effect on apoptosis and autophagy in breast cancer. The type of interaction between α-TOS and SSe was evaluated and levels of oxidative stress and apoptotic and autophagic markers were determined. SSe alone showed varying degrees of cytotoxicity on all the tested cell lines. Its combination with α-TOS was antagonistic in vitro in MCF7 and in vivo in mice bearing Ehrlich tumor compared to α-TOS-treated one. Combination of TOS with 2 μM of SSe increased the level of glutathione without changes in antiapoptotic markers Bcl-2 and Mcl-1 at 16 and 48 hrs. SSe decreased caspase 3 activity and protein level of caspases 7 and 9, while it increased autophagic markers beclin-1 and LC3B protein levels of MCF7 cells treated with α-TOS. In conclusion, SSe antagonizes α-TOS-induced apoptosis via inhibition of oxidative stress and promoting prosurvival machinery of autophagy. PMID:27127548

  14. Sodium selenite supplementation during pregnancy and lactation promotes anxiolysis and improves mnemonic performance in wistar rats' offspring.

    PubMed

    Laureano-Melo, Roberto; Império, Güínever Eustáquio do; da Silva-Almeida, Claudio; Kluck, George Eduardo Gabriel; Cruz Seara, Fernando de Azevedo; da Rocha, Fábio Fagundes; da Silveira, Anderson Luiz Bezerra; Reis, Luís Carlos; Ortiga-Carvalho, Tania Maria; da Silva Côrtes, Wellington

    2015-11-01

    Selenium is a micronutrient which is part of selenoprotein molecules and participates in a vast number of physiological roles and, among them,we have fetal and neonatal development. Therefore, the aimof this studywas to evaluate possible behavioral changes in offspring of female rats supplemented during pregnancy and lactation with sodium selenite. To address that, we treated two groups of female rats by saline or sodium selenite at a dose of 1mg/kg through oral route and performed neurochemical and behavioral tests. In the offspring, the thyroid profile and hippocampal neurochemistrywere evaluated. Behavioral testswere performed in pups both during childhood and adulthood. We found out that selenium (Se) supplementation increased serum levels of triiodothyronine (25%, p b 0.001) and thyroxine (18%, p b 0.05) and promoted a tryptophan hydroxylase 2 (TPH 2) expression decrease (17%, p b 0.01) and tyrosine hydroxylase (TH) expression increase (202%, p b 0.01) in the hippocampus. The cholinesterase activity was decreased (28%, p b 0.01) in Se supplemented rats, suggesting a neurochemical modulation in the hippocampal activity. During childhood, the Sesupplemented offspring had a reduction in anxiety-like behavior both in elevated plus maze test and in light–dark box test. In adulthood, Se-treated pups had an increase in the locomotor activity (36%, p b 0.05) and in rearing episodes (77%, p b 0.001) in the open field test, while in the elevated plus maze test they also exhibited an increase in the time spent in the open arms (243%, p b 0.01). For the object recognition test, Se-treated offspring showed increase in the absolute (230.16%, p b 0.05) and relative index discrimination (234%, p b 0.05). These results demonstrate that maternal supplementation by sodium selenite promoted psychobiological changes both during childhood and adulthood. Therefore, the behavioral profile observed possibly can be explained by neurochemical changes induced by thyroid hormones during

  15. Effect of Sodium Selenite on Pathological Changes and Renal Functions in Broilers Fed a Diet Containing Aflatoxin B1

    PubMed Central

    Liang, Na; Wang, Fengyuan; Peng, Xi; Fang, Jing; Cui, Hengmin; Chen, Zhengli; Lai, Weimin; Zhou, Yi; Geng, Yi

    2015-01-01

    To evaluate the renal toxicity of dietary aflatoxin B1 (AFB1) and ameliorating effects of added dietary sodium selenite in broiler, renal histopathological changes, ultrastructural changes, and renal function parameters were monitored at 7, 14, and 21 days of age. Two hundred one-day-old healthy male Avian broilers were divided into four groups, namely control group, AFB1 group (0.3 mg/kg AFB1), +Se group (0.4 mg/kg Se), and AFB1+Se group (0.3 mg/kg AFB1+0.4 mg/kg Se). Compared with that of the control group, the relative weight of kidney was increased in the AFB1 group. There were no significant differences between the AFB1+Se group and the control group. By histopathological observation, the renal epithelia were swelling and necrosis at 7 and 21 days of age. Ultrastructurally, the lipid droplets and expanded endoplasmic reticulum appeared in the plasma of epithelia cells in the AFB1 group. Enlarged mitochondria with degenerated cristae were observed in the +Se group. Compared with the control group, the contents of serum creatinine and serum uric acid in the AFB1 group were increased, while the activity of renal Na+-K+ ATPase was decreased. When 0.4 mg/kg selenium was added into the diet containing 0.3 mg/kg AFB1, there were no obvious histological changes in the AFB1+Se group, and the contents of the serum creatinine and serum uric acid contents and the activity of renal Na+-K+ ATPase were close to those in the control group. In conclusion, sodium selenite exhibited protective effects on AFB1-induced kidney toxicity in broilers. PMID:26371027

  16. Supplementation with Sodium Selenite and Selenium-Enriched Microalgae Biomass Show Varying Effects on Blood Enzymes Activities, Antioxidant Response, and Accumulation in Common Barbel (Barbus barbus)

    PubMed Central

    Kouba, Antonín; Velíšek, Josef; Stará, Alžběta; Masojídek, Jiří; Kozák, Pavel

    2014-01-01

    Yearling common barbel (Barbus barbus L.) were fed four purified casein-based diets for 6 weeks in outdoor cages. Besides control diet, these were supplemented with 0.3 mg kg−1 dw selenium (Se) from sodium selenite, or 0.3 and 1.0 mg kg−1 from Se-enriched microalgae biomass (Chlorella), a previously untested Se source for fish. Fish mortality, growth, Se accumulation in muscle and liver, and activity of selected enzymes in blood plasma, muscle, liver, and intestine were evaluated. There was no mortality, and no differences in fish growth, among groups. Se concentrations in muscle and liver, activity of alanine aminotransferase and creatine kinase in blood plasma, glutathione reductase (GR) in muscle, and GR and catalase in muscle and liver suggested that selenium from Se-enriched Chlorella is more readily accumulated and biologically active while being less toxic than sodium selenite. PMID:24772422

  17. Supplementation with sodium selenite and selenium-enriched microalgae biomass show varying effects on blood enzymes activities, antioxidant response, and accumulation in common barbel (Barbus barbus).

    PubMed

    Kouba, Antonín; Velíšek, Josef; Stará, Alžběta; Masojídek, Jiří; Kozák, Pavel

    2014-01-01

    Yearling common barbel (Barbus barbus L.) were fed four purified casein-based diets for 6 weeks in outdoor cages. Besides control diet, these were supplemented with 0.3 mg kg(-1) dw selenium (Se) from sodium selenite, or 0.3 and 1.0 mg kg(-1) from Se-enriched microalgae biomass (Chlorella), a previously untested Se source for fish. Fish mortality, growth, Se accumulation in muscle and liver, and activity of selected enzymes in blood plasma, muscle, liver, and intestine were evaluated. There was no mortality, and no differences in fish growth, among groups. Se concentrations in muscle and liver, activity of alanine aminotransferase and creatine kinase in blood plasma, glutathione reductase (GR) in muscle, and GR and catalase in muscle and liver suggested that selenium from Se-enriched Chlorella is more readily accumulated and biologically active while being less toxic than sodium selenite. PMID:24772422

  18. Maturation arrest of neutrophils-a possible reason for the leucopenia in sodium selenite induced sub-chronic selenosis in cow calves.

    PubMed

    Rampal, Satyavan; Kumar, Rakesh; Randhawa, Charanjit S; Sood, Naresh

    2008-01-01

    The effect of long-term administration of sodium selenite on leucocyte indices of peripheral blood of calves was determined. Nine calves, 9-12 months old, with an average body weight of 104kg were divided into three groups. Calves of groups 2 and 3 were administered with sodium selenite at 0.1 and 0.25mg/kg body weight for 98 consecutive days. The clinical signs characteristic of selenosis viz. alopecia, cracking of hooves, intradigital lesions and discoloration of hard palate, started appearing from 45 to 60 days onwards with high dose, whereas only subtle indications of toxicosis were observed in the low-dose group. The prolonged administration of sodium selenite produced a progressive and dose-dependent decline in the circulating leucocyte count with concomitant decline in the circulating neutrophil count. There was a high negative correlation (0.94) between blood selenium levels and neutrophils. Granulocyte/agranulocyte ratio was also significantly reduced in the treated animals. Evaluation of bone marrow smears revealed a decline in the myeloid to erythroid ratio. In addition, there was also maturation arrest of neutrophils at promyelocyte or myelocyte level as shown by differential granulocyte count in the bone marrow. The results indicated that host's immune response may be adversely affected. PMID:21783834

  19. Mercuric chloride induced hepatotoxic and hematologic changes in rats: The protective effects of sodium selenite and vitamin E.

    PubMed

    Uzunhisarcikli, Meltem; Aslanturk, Ayse; Kalender, Suna; Apaydin, Fatma Gokce; Bas, Hatice

    2016-09-01

    This study focuses on investigating the possible protective effect of sodium selenite (Na2SeO3) and/or vitamin E against mercuric chloride (HgCl2)-induced hepatotoxicity in rat. Male rats were given HgCl2 (1 mg/kg body weight (bw)) and HgCl2 plus Na2SeO3 (0.25 mg/kg bw) and/or vitamin E (100 mg/kg bw) daily via gavage for 4 weeks. HgCl2-treated groups had significantly higher white blood cell and thrombocyte counts than the control group. Serum activities of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, γ-glutamyl-transferase, and lactate dehydrogenase significantly increased and serum levels of total protein, albumin, triglyceride, total cholesterol, and low-density lipoprotein cholesterol significantly decreased in the HgCl2-treated groups compared with control group. Malondialdehyde level significantly increased and superoxide dismutase, catalase, and glutathione peroxidase activities decreased in liver tissue of HgCl2-treated rats. Also, HgCl2 exposure resulted in histopathological changes. Supplementation of Na2SeO3 and/or vitamin E provided partial protection in hematological and biochemical parameters that were altered by HgCl2 As a result, Na2SeO3 and/or vitamin E significantly reduced HgCl2-induced hepatotoxicity, but not protected completely. PMID:25757480

  20. Isolation of a selenite-reducing and cadmium-resistant bacterium Pseudomonas sp. strain RB for microbial synthesis of CdSe nanoparticles.

    PubMed

    Ayano, Hiroyuki; Miyake, Masaki; Terasawa, Kanako; Kuroda, Masashi; Soda, Satoshi; Sakaguchi, Toshifumi; Ike, Michihiko

    2014-05-01

    Bacteria capable of synthesizing CdSe from selenite and cadmium ion were enriched from a soil sample. After repeated transfer of the soil-derived bacterial cultures to a new medium containing selenite and cadmium ion 42 times (during 360 days), an enrichment culture that can simultaneously remove selenite and cadmium ion (1 mM each) from the liquid phase was obtained. The culture's color became reddish-brown, indicating CdSe nanoparticle production, as confirmed by energy-dispersive x-ray spectra (EDS). As a result of isolation operations, the bacterium that was the most responsible for synthesizing CdSe, named Pseudomonas sp. RB, was obtained. Transmission electron microscopy and EDS revealed that this strain accumulated nanoparticles (10-20 nm) consisting of selenium and cadmium inside and on the cells when cultivated in the same medium for the enrichment culture. This report is the first describing isolation of a selenite-reducing and cadmium-resistant bacterium. It is useful for CdSe nanoparticle synthesis in the simple one-vessel operation. PMID:24216457

  1. Microbial manufacture of chalcogenide-based nanoparticles via the reduction of selenite using Veillonella atypica: an in situ EXAFS study

    NASA Astrophysics Data System (ADS)

    Pearce, Carolyn I.; Coker, Victoria S.; Charnock, John M.; Pattrick, Richard A. D.; Mosselmans, J. Frederick W.; Law, Nicholas; Beveridge, Terry J.; Lloyd, Jonathan R.

    2008-04-01

    The ability of metal-reducing bacteria to produce nanoparticles, and their precursors, can be harnessed for the biological manufacture of fluorescent, semiconducting nanomaterials. The anaerobic bacterium Veillonella atypica can reduce selenium oxyanions to form nanospheres of elemental selenium. These selenium nanospheres are then further reduced by the bacterium to form reactive selenide which could be precipitated with a suitable metal cation to produce nanoscale chalcogenide precipitates, such as zinc selenide, with optical and semiconducting properties. The whole cells used hydrogen as the electron donor for selenite reduction and an enhancement of the reduction rate was observed with the addition of a redox mediator (anthraquinone disulfonic acid). A novel synchrotron-based in situ time-resolved x-ray absorption spectroscopy technique was used, in conjunction with ion chromatography and inductively coupled plasma-atomic emission spectroscopy, to study the mechanisms and kinetics of the microbial reduction of selenite to selenide. The products of this biotransformation were also assessed using electron microscopy, energy-dispersive spectroscopy, x-ray diffraction and fluorescence spectroscopy. This process offers the potential to prepare chalcogenide-based nanocrystals, for application in optoelectronic devices and biological labelling, from more environmentally benign precursors than those used in conventional organometallic synthesis.

  2. Microbial manufacture of chalcogenide-based nanoparticles via the reduction of selenite using Veillonella atypica: an in situ EXAFS study.

    PubMed

    Pearce, Carolyn I; Coker, Victoria S; Charnock, John M; Pattrick, Richard A D; Mosselmans, J Frederick W; Law, Nicholas; Beveridge, Terry J; Lloyd, Jonathan R

    2008-04-16

    The ability of metal-reducing bacteria to produce nanoparticles, and their precursors, can be harnessed for the biological manufacture of fluorescent, semiconducting nanomaterials. The anaerobic bacterium Veillonella atypica can reduce selenium oxyanions to form nanospheres of elemental selenium. These selenium nanospheres are then further reduced by the bacterium to form reactive selenide which could be precipitated with a suitable metal cation to produce nanoscale chalcogenide precipitates, such as zinc selenide, with optical and semiconducting properties. The whole cells used hydrogen as the electron donor for selenite reduction and an enhancement of the reduction rate was observed with the addition of a redox mediator (anthraquinone disulfonic acid). A novel synchrotron-based in situ time-resolved x-ray absorption spectroscopy technique was used, in conjunction with ion chromatography and inductively coupled plasma-atomic emission spectroscopy, to study the mechanisms and kinetics of the microbial reduction of selenite to selenide. The products of this biotransformation were also assessed using electron microscopy, energy-dispersive spectroscopy, x-ray diffraction and fluorescence spectroscopy. This process offers the potential to prepare chalcogenide-based nanocrystals, for application in optoelectronic devices and biological labelling, from more environmentally benign precursors than those used in conventional organometallic synthesis. PMID:21825617

  3. Protective effect of sodium selenite and zinc sulfate on intensive swimming-induced testicular gamatogenic and steroidogenic disorders in mature male rats.

    PubMed

    Jana, Kuladip; Samanta, Pravat K; Manna, Indranil; Ghosh, Prasanta; Singh, Narendra; Khetan, Ramawatar P; Ray, Binoy R

    2008-10-01

    To investigate the ameliorative potential of sodium selenite and zinc sulfate on intensive-swimming-induced testicular disorders, 48 Wistar male rats (age, 4 months; mass, 146.2 +/- 3.6 g) were randomly divided into 4 groups: the unexercised-control group (n = 12); the exercised group (n = 12); the control supplemented group (n = 12); and the exercised supplemented group (n = 12). For 10 weeks, the exercised rats underwent a protocol that consisted of 4 h.d-1 swimming, for 6 d.week-1; the control rats did not exercise. For 10 weeks, both the supplemented groups received an oral daily dose of a combination of sodium selenite and zinc sulfate (6 and 3 mg.kg body mass-1, respectively). After 10 weeks, a significant reduction (p < 0.05) was seen in rats in the exercised group, compared with rats in both control groups, in paired testicular masses; in epididymal sperm count; in testicular Delta5, 3beta-hydroxysteroid dehydrogenase (HSD) and 17beta-HSD; in plasma levels of testosterone, luteinizing hormone, follicle-stimulating hormone, and prolactin; in the numbers of preleptotine spermatocytes, midpachytene spermatocytes, and stage 7 spermatids of the stage VII seminiferous epithelium cycle; and in fertility performance. As well, a significant increase (p < 0.05) was seen in the exercised group, compared with both control groups, in plasma corticosterone levels and in testicular content of malondialdehyde and catalase activity. At the same time, there was a significant reduction (p < 0.05) in the exercised group, compared with both control groups, in plasma concentrations of zinc and selenium; in the testicular content of glutathione (GSH), the glutathione and glutathione disulphide (GSSG) ratio, ascorbic acid, and alpha-tocopherol; and in testicular activities of superoxide dismutase, glutathione-peroxidase, and glutathione-S-transferase in the testes. No significant changes were seen in the number of spermatogonia-A from the stage VII seminiferous epithelium cycle or

  4. Dietary sodium selenite affects host intestinal and systemic immune response and disease susceptibility to necrotic enteritis in commercial broilers.

    PubMed

    Xu, S Z; Lee, S H; Lillehoj, H S; Bravo, D

    2015-01-01

    1. This study was to evaluate the effects of supplementary dietary selenium (Se) given as sodium selenite on host immune response against necrotic enteritis (NE) in commercial broiler chickens. 2. Chicks were fed from hatching on a non-supplemented diet or diets supplemented with different levels of Se (0.25, 0.50, and 1.00 Se mg/kg). To induce NE, broiler chickens were orally infected with Eimeria maxima at 14 d of age and then with Clostridium perfringens 4 d later using our previously established NE disease model. 3. NE-associated clinical signs and host protective immunity were determined by body weight changes, intestinal lesion scores, and serum antibodies against α-toxin and necrotic enteritis B (NetB) toxin. The effects of dietary Se on the gene expression of pro-inflammatory cytokines e.g., interleukin (IL)-1β, IL-6, IL-8LITAF (lipopolysaccharide-induced TNFα-factor), tumour necrosis factor (TNF) SF15, and inducible nitric oxide synthase (iNOS), glutathione peroxidase 7 (GPx7), and avian β-defensins (AvBD) 6, 8, and 13 (following NE infection) were analysed in the intestine and spleen. 4. The results showed that dietary supplementation of newly hatched broiler chicks with 0.25 Se mg/kg from hatch significantly reduced NE-induced gut lesions compared with infected birds given a non-supplemented diet. The levels of serum antibody against the NetB toxin in the chicks fed with 0.25 and 0.50 mg/kg Se were significantly higher than the non-supplemented control group. The transcripts for IL-1β, IL-6, IL-8, iNOS, LITAF, and GPx7, as well as AvBD6, 8, and 13 were increased in the intestine and spleen of Se-supplemented groups, whereas transcript for TNFSF15 was decreased in the intestine. 5. It was concluded that dietary supplementation with optimum levels of Se exerted beneficial effects on host immune response to NE and reduced negative consequence of NE-induced immunopathology. PMID:25387235

  5. Thallium selenite

    Integrated Risk Information System (IRIS)

    Thallium selenite ; CASRN 12039 - 52 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogen

  6. Immobilization of selenite in soil and groundwater using stabilized Fe-Mn binary oxide nanoparticles.

    PubMed

    Xie, Wenbo; Liang, Qiqi; Qian, Tianwei; Zhao, Dongye

    2015-03-01

    Stabilized Fe-Mn binary oxide nanoparticles were synthesized and tested for removal and in-situ immobilization of Se(IV) in groundwater and soil. A water-soluble starch or food-grade carboxymethyl cellulose (CMC) was used as a stabilizer to facilitate in-situ delivery of the particles into contaminated soil. While bare and stabilized nanoparticles showed rapid sorption kinetics, starch-stabilized Fe-Mn offered the greatest capacity for Se(IV). The Langmuir maximum capacity was determined to be 109 and 95 mg-Se/g-Fe for starch- and CMC-stabilized nanoparticles, respectively, and the high Se(IV) uptake was observed over the typical groundwater pH range of 5-8. Column breakthrough tests indicated that the stabilized nanoparticles were deliverable in a model sandy soil while non-stabilized particles were not. When a Se(IV)-spiked soil was treated in situ with the nanoparticles, >90% water leachable Se(IV) was transferred to the nanoparticle phase, and thereby immobilized as the particles were retained in the downstream soil matrix. The nanoparticle amendment reduced the TCLP (toxicity characteristic leaching procedure) leachability and the California WET (waste extraction test) leachability of Se(IV) by 76% and 71%, respectively. The technology holds the potential to fill a major technology gap in remediation of metals-contaminated soil and groundwater. PMID:25577492

  7. Selenium species in the roots and shoots of chickpea plants treated with different concentrations of sodium selenite.

    PubMed

    Lyubenova, Lyudmila; Sabodash, Xenia; Schröder, Peter; Michalke, Bernhard

    2015-11-01

    The trace element selenium has an essential role for human health. It is involved in redox center functions, and it is related to the immune system response. Legumes are among the main suppliers of selenium into the human food chain. Not only Se concentration as such but also more the chemical species of Se is of higher importance for successful Se supply to the human diet and its bioavailability. The current study was focused on the investigation of the Se species present in chickpea plants exposed to 0, 10, 25, 50, and 100 μM selenite in short- and long-term treatment studies. The linear increase of total Se concentration could be linked to the increased concentrations of Se exposure. The selenium species (SeMet, SeCys, selenite, selenate, GPx) detected in varying concentrations in shoots and roots depend on the exposure's concentration and duration. The investigation showed that chickpea can accumulate Se in favorable concentrations and its transformation to bioavailable Se species may have positive impacts on human health and aid to implement Se into the diet. PMID:26122563

  8. Dynamic equilibrium of endogenous selenium nanoparticles in selenite-exposed cancer cells: a deep insight into the interaction between endogenous SeNPs and proteins.

    PubMed

    Bao, Peng; Chen, Song-Can; Xiao, Ke-Qing

    2015-12-01

    Elemental selenium (Se) was recently found to exist as endogenous nanoparticles (i.e., SeNPs) in selenite-exposed cancer cells. By sequestrating critical intracellular proteins, SeNPs appear capable of giving rise to multiple cytotoxicity mechanisms including inhibition of glycolysis, glycolysis-dependent mitochondrial dysfunction, microtubule depolymerization and inhibition of autophagy. In this work, we reveal a dynamic equilibrium of endogenous SeNP assembly and disassembly in selenite-exposed H157 cells. Endogenous SeNPs are observed both in the cytoplasm and in organelles. There is an increase in endogenous SeNPs between 24 h and 36 h, and a decrease between 36 h and 72 h according to transmission electron microscopy results and UV-Vis measurements. These observations imply that elemental Se in SeNPs could be oxidized back into selenite by scavenging superoxide radicals and ultimately re-reduced into selenide; then the assembly and disassembly of SeNPs proceed simultaneously with the sequestration and release of SeNP high-affinity proteins. There is also a possibility that the reduction of elemental Se to selenide pathway may lie in selenite-exposed cancer cells, which results in the assembly and disassembly of endogenous SeNPs. Genome-wide expression analysis results show that endogenous SeNPs significantly altered the expression of 504 genes, compared to the control. The endogenous SeNPs induced mitochondrial impairment and decreasing of the annexin A2 level can lead to inhibition of cancer cell invasion and migration. This dynamic flux of endogenous SeNPs amplifies their cytotoxic potential in cancer cells, thus provide a starting point to design more efficient intracellular self-assembling systems for overcoming multidrug resistance. PMID:26456389

  9. Delayed formation of zero-valent selenium nanoparticles by Bacillus mycoides SeITE01 as a consequence of selenite reduction under aerobic conditions

    PubMed Central

    2014-01-01

    Background Selenite (SeO32−) oxyanion shows severe toxicity to biota. Different bacterial strains exist that are capable of reducing SeO32− to non-toxic elemental selenium (Se0), with the formation of Se nanoparticles (SeNPs). These SeNPs might be exploited for technological applications due to their physico-chemical and biological characteristics. The present paper discusses the reduction of selenite to SeNPs by a strain of Bacillus sp., SeITE01, isolated from the rhizosphere of the Se-hyperaccumulator legume Astragalus bisulcatus. Results Use of 16S rRNA and GyrB gene sequence analysis positioned SeITE01 phylogenetically close to B. mycoides. On agarized medium, this strain showed rhizoid growth whilst, in liquid cultures, it was capable of reducing 0.5 and 2.0 mM SeO32− within 12 and 24 hours, respectively. The resultant Se0 aggregated to form nanoparticles and the amount of Se0 measured was equivalent to the amount of selenium originally added as selenite to the growth medium. A delay of more than 24 hours was observed between the depletion of SeO32 and the detection of SeNPs. Nearly spherical-shaped SeNPs were mostly found in the extracellular environment whilst rarely in the cytoplasmic compartment. Size of SeNPs ranged from 50 to 400 nm in diameter, with dimensions greatly influenced by the incubation times. Different SeITE01 protein fractions were assayed for SeO32− reductase capability, revealing that enzymatic activity was mainly associated with the membrane fraction. Reduction of SeO32− was also detected in the supernatant of bacterial cultures upon NADH addition. Conclusions The selenite reducing bacterial strain SeITE01 was attributed to the species Bacillus mycoides on the basis of phenotypic and molecular traits. Under aerobic conditions, the formation of SeNPs were observed both extracellularly or intracellullarly. Possible mechanisms of Se0 precipitation and SeNPs assembly are suggested. SeO32− is proposed to be enzimatically reduced to

  10. High dietary intake of sodium selenite does not affect gene mutation frequency in rat colon and liver.

    PubMed

    Zeng, Huawei; Uthus, Eric O; Ross, Sharon A; Davis, Cindy D

    2009-10-01

    Our previous studies have shown that selenium (Se) is protective against dimethylhydrazine (DMH)-induced preneoplastic colon cancer lesions, and protection against DNA damage has been hypothesized to be one mechanism for the anticancer effect of Se. The present study was designed to determine whether dietary selenite affects somatic mutation frequency in vivo. We used the Big Blue transgenic model to evaluate the in vivo mutation frequency of the cII gene in rats fed either a Se-deficient (0 microg Se/g diet) or Se-supplemented diet (0.2 or 2 microg Se/g diet; n = 3 rats/diet in experiment 1 and n = 5 rats/group in experiment 2) and injected with DMH (25 mg/kg body weight, i.p.). There were no significant differences in body weight between the Se-deficient and Se-supplemented (0.2 or 2 microg Se/g diet) rats, but the activities of liver glutathione peroxidase and thioredoxin reductase and concentration of liver Se were significantly lower (p < 0.0001) in Se-deficient rats compared to rats supplemented with Se. We found no effect of dietary Se on liver 8-hydroxy-2'-deoxyguanosine. Gene mutation frequency was significantly lower in liver (p < 0.001) than that of colon regardless of dietary Se. However, there were no differences in gene mutation frequency in DNA from colon mucosa or liver from rats fed the Se-deficient diet compared to those fed the Se-supplemented (0.2 or 2 microg Se/g diet) diet. Although gene mutations have been implicated in the etiology of cancer, our data suggest that decreasing gene mutation is not likely a key mechanism through which dietary selenite exerts its anticancer action against DMH-induced preneoplastic colon cancer lesions in a Big Blue transgenic rat model. PMID:19263001

  11. Selenium (sodium selenite) causes cytotoxicity and apoptotic mediated cell death in PLHC-1 fish cell line through DNA and mitochondrial membrane potential damage.

    PubMed

    Selvaraj, Vellaisamy; Tomblin, Justin; Yeager Armistead, Mindy; Murray, Elizabeth

    2013-01-01

    Elevated concentration of selenium poses a toxic threat to organisms inhabiting aquatic ecosystems influenced by excessive inputs from anthropogenic sources. Selenium is also an essential micronutrient in living things, particularly in fish, and provides antioxidant properties to tissues. Whole fish and hepatocytes in primary culture show selenite toxicity above threshold levels. The present study was designed to investigate the process by which selenite exposure causes cellular toxicity and apoptotic and necrotic cell death in fish hepatoma cell line PLHC-1. PLHC-1 cells were exposed to various selenite concentrations (1, 10, 50 and 100 μM) for 10, 20 and 40 h intervals. The 24h inhibitory concentration 50 (IC₅₀) of selenite in PLHC-1 cell line was found to be 237 μM. Flow cytometery data showed that selenite exposed cells promote apoptotic and necrotic mediated cell death when selenite concentrations were ≥10 μM compared to control. Selenite exposure was associated with a significant increase of caspase-3 activities suggesting the induction of apoptosis. Selenite exposure at high levels (≥10 μM) and longer exposure times (≥20 h) induces mitochondrial membrane potential damage (ΔΨ(m)), DNA damage and elevated production of ROS which could be associated with cell death. PMID:23158585

  12. Effects of different dl-selenomethionine and sodium selenite levels on growth performance, immune functions and serum thyroid hormones concentrations in broilers.

    PubMed

    Wang, Y; Wang, H; Zhan, X

    2016-06-01

    This trial was conducted in a 2 × 3 + 1 factorial arrangement based on a completely randomized design to evaluate the effects of different dl-selenomethionine (dl-Se-Met) and sodium selenite (SS) levels on growth performance, immune functions and serum thyroid hormones concentrations in broilers. A total of 840 Ross 308 broilers (7 days old) were allocated by body weight to seven treatments (three replicates of 40 birds each treatment) including (1) basal diet (containing 0.04 mg of selenium (Se)/kg; control) without supplementary Se; (2, 3 and 4) basal diet + 0.05, 0.15 or 0.25 mg/kg Se as SS; (5, 6 and 7) basal diet + 0.05, 0.15 or 0.25 mg/kg Se as dl-Se-Met. The experiment lasted 42 days. The results revealed that dietary Se supplementation improved (p < 0.05) average daily gain, feed efficiency, immune organ index, serum immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM) and triiodothyronine (T3 ) concentrations and decreased (p < 0.01) thyroxine (T4 )/T3 ratio in serum compared with the control. Broilers receiving the dl-Se-Met-supplemented diets had higher (p < 0.05) feed efficiency, thymus index, the amounts of IgA, IgG, IgM and T3 as well as lower (p < 0.05) serum T4 concentrations and T4 /T3 ratio than those consuming the SS-supplemented diets. Serum IgA and IgM levels of broilers fed 0.15 mg Se/kg were significantly higher (p < 0.05) than those of broilers fed 0.05 or 0.25 mg Se/kg. In summary, we concluded that dl-Se-Met is more effective than SS in increasing immunity and promoting conversion of T4 to T3 , thus providing an effective way to improve the growth performance of broilers. Besides, based on a consideration of all experiment indices, 0.15 mg Se/kg was suggested to be the optimal level of Se supplementation under the conditions of this study. PMID:26608352

  13. Bioavailability of selenium in 'Jose' tall wheatgrass (Thinopyrum ponticum var 'Jose') hay as a substitute for sodium selenite in the diets of dairy cattle.

    PubMed

    Cun, G S; Robinson, P H; Benes, S E

    2015-06-15

    Due to its potential toxicity to wildlife, selenium (Se) is a highly regulated trace element in the San Joaquin Valley (SJV) of California. Tall wheatgrass (TWG) is a Se-accumulating, salt tolerant forage suitable for cropping systems which re-use agricultural drainage waters. Utilization of TWG hay as an alternative Se supplement for dairy cattle could reduce the importation of 'new' Se into the SJV in the form of sodium selenite (SS) diet supplements. Our study used Se-enriched (4.65 mg/kg DM) TWG hay as a Se source for lactating dairy cows and measured Se accumulation in milk, blood, urine and feces to assess its bioavailability using several indices. Using a 3×3 Latin Square design, three pens of ~310 cows each were fed a similar total mixed ration over 4 week periods, except for Se which was higher in TWG and SS diets (0.53 and 0.65 mg/kg DM) vs. Control diet (0.35 mg/kg DM). Feeding Se-enriched TWG increased blood Se by 6.4% over Control; whereas SS increased it by 4.8%, suggesting higher Se bioavailability for TWG vs. SS. Marginal Se outputs in milk, feces and urine were judged to be better indicators of bioavailability as they estimate Se specifically from supplemental SS or TWG hay. In milk, TWG cows expressed 3.0% of supplemented Se vs. 0.6% for SS cows, supporting higher Se bioavailability for TWG. In contrast, more supplemental Se was retained and not expressed in feces by the SS cows (72.5%) vs. TWG cows (55.1%) which suggested higher Se bioavailability for SS. Based on published guidelines, Se intakes were 'adequate' for cows in all treatment groups, but milk and fat production increased with Se supplementation suggesting that Control cows were Se-deficient to some extent. Collectively, results suggest that the Se in TWG hay had comparable bioavailability to Se in the base diet. PMID:25747375

  14. Comparative study of DL-selenomethionine vs sodium selenite and seleno-yeast on antioxidant activity and selenium status in laying hens.

    PubMed

    Jing, C L; Dong, X F; Wang, Z M; Liu, S; Tong, J M

    2015-05-01

    The aim of this study was to compare the effect of DL-selenomethionine (SM) with 2 routinely used Se sources, sodium selenite (SS) and seleno-yeast (SY), on relative bioavailability based on antioxidant activity and tissue Se content. Six hundred thirty 131-day-old brown laying hens were randomly assigned to 7 treatments for 168 d (24 wks) with 6 replicates of 15 hens per replicate. The SS and SY animals were supplemented a cornmeal and soybean diet that supplied a total Se 0.3 mg/kg whereas SM was added at 4 different levels to the total Se at 0.1, 0.3, 0.5 and 0.7 mg/kg. All hens fed the Se-supplemented diet showed higher glutathione peroxidase (GSH-Px) activity (P < 0.01), higher superoxide dismutase (SOD) activity (P < 0.05), lower malondialdehyde (MDA) content (P < 0.05) in plasma, and greater Se contents in egg yolks, albumen, leg muscle, breast muscle, liver, and plasma compared with those fed the control diet (P < 0.01). The organic sources (SY and SM) exhibited a greater ability to increase the GSH-Px activity (P < 0.01) and Se content in albumen (P < 0.01), leg, and breast muscles (P = 0.0099 and P = 0.0014, respectively) than the SS that was added at 0.3 mg Se/kg. The higher SM added levels increased the GSH-Px activity until the dose of 0.5mg Se/kg (P < 0.01).The greater Se concentrations in albumen, muscle and liver appeared in the higher SM-added level, as well as above the dose of 0.1 mg Se/kg (P < 0.01). In addition, hens fed the diet with SM accumulated more Se in albumen, leg, and breast muscle than those fed diets with SY (P < 0.05). These results confirmed the higher ability of organic Se sources to increase the antioxidant activity and Se deposition in egg albumen, leg, and breast muscles compared with SS, and demonstrated a significantly better efficiency of SM compared with SY for albumen and muscle Se enrichment. PMID:25717085

  15. Phase-separation inhibitors and prevention of selenite cataract.

    PubMed Central

    Clark, J I; Steele, J E

    1992-01-01

    The variation of the phase-separation temperature (Tc) was studied in lenses during formation of cataracts induced by a subcutaneous injection of sodium selenite. In normal control animals, the Tc decreased monotonically with increasing age. Approximately 2 days after administration of the selenite the Tc decreased sharply to a minimum, and then at day 4 the Tc increased dramatically toward body temperature. Mature irreversible cataracts formed approximately 6 days after injection of the selenite. Intraperitoneal administration of WR-77913, a phase-separation inhibitor, prevented the abnormal variation of Tc in vivo. When injected into control animals without selenite, WR-77913 produced no abnormal variation in Tc. The results confirm that Tc is a sensitive measure of early changes in the lens and that opacification associated with abnormal variation in Tc can be prevented in vivo by using a phase-separation inhibitor. Images PMID:1311849

  16. Sodium hydroxide catalyzed monodispersed high surface area silica nanoparticles

    NASA Astrophysics Data System (ADS)

    Bhakta, Snehasis; Dixit, Chandra K.; Bist, Itti; Abdel Jalil, Karim; Suib, Steven L.; Rusling, James F.

    2016-07-01

    Understanding of the synthesis kinetics and our ability to modulate medium conditions allowed us to generate nanoparticles via an ultra-fast process. The synthesis medium is kept quite simple with tetraethyl orthosilicate (TEOS) as precursor and 50% ethanol and sodium hydroxide catalyst. Synthesis is performed under gentle conditions at 20 °C for 20 min Long synthesis time and catalyst-associated drawbacks are most crucial in silica nanoparticle synthesis. We have addressed both these bottlenecks by replacing the conventional Stober catalyst, ammonium hydroxide, with sodium hydroxide. We have reduced the overall synthesis time from 20 to 1/3 h, ∼60-fold decrease, and obtained highly monodispersed nanoparticles with 5-fold higher surface area than Stober particles. We have demonstrated that the developed NPs with ∼3-fold higher silane can be used as efficient probes for biosensor applications.

  17. Transformation of sodium bicarbonate and CO2 into sodium formate over NiPd nanoparticle catalyst

    PubMed Central

    Wang, Mengnan; Zhang, Jiaguang; Yan, Ning

    2013-01-01

    The present research systematically investigated, for the first time, the transformation of sodium bicarbonate and CO2 into sodium formate over a series of Ni based metal nanoparticles (NPs). Ni NPs and eight NiM (M stands for a second metal) NPs were prepared by a facile wet chemical process and then their catalytic performance were evaluated in sodium bicarbonate hydrogenation. Bimetallic NiPd NPs with a composition of 7:3 were found to be superior for this reaction, which are more active than both pure Ni and Pd NPs. Hot filtration experiment suggested the NPs to be the truly catalytic active species and kinetic analysis indicated the reaction mechanism to be different than most homogeneous catalysts. The enhanced activity of the bimetallic nanoparticles may be attributed to their smaller size and improved stability. PMID:24790945

  18. Transformation of Sodium Bicarbonate and CO2 into Sodium Formate over NiPd Nanoparticle Catalyst

    NASA Astrophysics Data System (ADS)

    Wang, Mengnan; Zhang, Jiaguang; Yan, Ning

    2013-09-01

    The present research systematically investigated, for the first time, the transformation of sodium bicarbonate and CO2 into sodium formate over a series of Ni based metal nanoparticles (NPs). Ni NPs and eight NiM (M stands for a second metal) NPs were prepared by a facile wet chemical process and then their catalytic performance were evaluated in sodium bicarbonate hydrogenation. Bimetallic NiPd NPs with a composition of 7:3 were found to be superior for this reaction, which are more active than both pure Ni and Pd NPs. Hot filtration experiment suggested the NPs to be the truly catalytic active species and kinetic analysis indicated the reaction mechanism to be different than most homogeneous catalysts. The enhanced activity of the bimetallic nanoparticles may be attributed to their smaller size and improved stability.

  19. Hollow nanoparticle cathode materials for sodium electrochemical cells and batteries

    DOEpatents

    Shevchenko, Elena; Rajh, Tijana; Johnson, Christopher S.; Koo, Bonil

    2016-07-12

    A cathode comprises, in its discharged state, a layer of hollow .gamma.-Fe.sub.2O.sub.3 nanoparticles disposed between two layers of carbon nanotubes, and preferably including a metallic current collector in contact with one of the layers of carbon nanotubes. Individual particles of the hollow .gamma.-Fe.sub.2O.sub.3 nanoparticles comprise a crystalline shell of .gamma.-Fe.sub.2O.sub.3 including cation vacancies within the crystal structure of the shell (i.e., iron vacancies of anywhere between 3% to 90%, and preferably 44 to 77% of available octahedral iron sites). Sodium ions are intercalated within at least some of the cation vacancies within the crystalline shell of the hollow .gamma.-Fe.sub.2O.sub.3 nanoparticles.

  20. Apoptosis in MCF-7 breast cancer cells induced by S-alkenylmercaptocysteine (CySSR) species derived from Allium tissues in combination with sodium selenite.

    PubMed

    Zhang, Wei; Xiao, Hang; Parkin, Kirk L

    2014-06-01

    S-Allylmercaptocysteine (CySSA) from garlic is known to exhibit anti-cancer effects. Apoptosis induction by CySSA was contrasted with S-1-propenylmercaptocysteine (CySSPe) (the major onion analog) in the presence of Na2SeO3 (Se) in breast cancer cells MCF-7. The dose of CySSA or CySSPe alone required to reduce viable cells by 50% was >400μM, and this was reduced to 62μM and 91μM for CySSA+Se and CySSPe+Se, respectively, at molar ratios of 39:1. Synergism of the mixtures was confirmed by isobologram analysis and the treatments evoked enhanced thiol efflux from MCF-7 cells. Apoptosis was confirmed by Annexin-V and propidium iodide staining. Cell cycle arrest occurred at the G2/M and sub-G1 interphases. Both CySSR+Se mixtures reduced the levels of Akt. CySSPe+Se elevated GSK-3 protein levels, whereas CySSA+Se did not. CySSR+Se mixtures enhanced phospho-c-Jun levels, with CySSA+Se more potent than CySSPe+Se. Corresponding increases in phospho-p53, Bax and Bad levels were observed, indicating apoptosis occurred via the mitochondrial pathway. Lack of caspases 6/7 activation implicated a caspase-independent pathway for apoptosis. Reduction of imported CySSR and export of thiols by MCF-7 cells facilitates the reduction of selenite to yield H2Se, a cytotoxic agent. This appears to be the first report of an anti-cancer effect of CySSPe. PMID:24614136

  1. Selenium uptake, tolerance and reduction in Flammulina velutipes supplied with selenite

    PubMed Central

    Zhang, Dan

    2016-01-01

    Recently, selenium (Se) enriched mushrooms have been exploited as dietary Se supplements, but our knowledge of the metabolic process during the Se enrichment process is far from complete. In this study, the uptake, tolerance and reduction of selenite in a widely cultivated mushroom, Flammulina velutipes, was investigated. The results showed that pH variation (from 5.5–7.5), metabolic inhibitor (0.1 mM 2,4-DNP) and P or S starvation led to 11–26% decreases in the selenite uptake rate of F. velutipes. This indicates that a minor portion of the selenite uptake was metabolism dependent, whereas a carrier-facilitated passive transport may be crucial. Growth inhibition of F. velutipes initiated at 0.1 mM selenite (11% decrease in the growth rate) and complete growth inhibition occurred at 3 mM selenite. A selenite concentration of 0.03–0.1 mM was recommended to maintain the balance between mycelium production and Se enrichment. F. velutipes was capable of reducing selenite to elemental Se [Se(0)] including Se(0) nanoparticles, possibly as a detoxification mechanism. This process depended on both selenite concentration and metabolism activity. Overall, the data obtained provided some basic information for the cultivation of the selenized F. velutipes, and highlighted the opportunity of using mushrooms for the production of Se(0) nanoparticles. PMID:27547513

  2. Selenium uptake, tolerance and reduction in Flammulina velutipes supplied with selenite.

    PubMed

    Wang, Jipeng; Wang, Bo; Zhang, Dan; Wu, Yanhong

    2016-01-01

    Recently, selenium (Se) enriched mushrooms have been exploited as dietary Se supplements, but our knowledge of the metabolic process during the Se enrichment process is far from complete. In this study, the uptake, tolerance and reduction of selenite in a widely cultivated mushroom, Flammulina velutipes, was investigated. The results showed that pH variation (from 5.5-7.5), metabolic inhibitor (0.1 mM 2,4-DNP) and P or S starvation led to 11-26% decreases in the selenite uptake rate of F. velutipes. This indicates that a minor portion of the selenite uptake was metabolism dependent, whereas a carrier-facilitated passive transport may be crucial. Growth inhibition of F. velutipes initiated at 0.1 mM selenite (11% decrease in the growth rate) and complete growth inhibition occurred at 3 mM selenite. A selenite concentration of 0.03-0.1 mM was recommended to maintain the balance between mycelium production and Se enrichment. F. velutipes was capable of reducing selenite to elemental Se [Se(0)] including Se(0) nanoparticles, possibly as a detoxification mechanism. This process depended on both selenite concentration and metabolism activity. Overall, the data obtained provided some basic information for the cultivation of the selenized F. velutipes, and highlighted the opportunity of using mushrooms for the production of Se(0) nanoparticles. PMID:27547513

  3. Complexation between sodium dodecyl sulfate and amphoteric polyurethane nanoparticles.

    PubMed

    Qiao, Yong; Zhang, Shifeng; Lin, Ouya; Deng, Liandong; Dong, Anjie

    2007-09-27

    The complexation between negatively charged sodium dodecyl sulfate (SDS) and positively charged amphoteric polyurethane (APU) self-assembled nanoparticles (NPs) containing nonionic hydrophobic segments is studied by dynamic light scattering, pyrene fluorescent probing, zeta-potential, and transmission electron microscopy (TEM) in the present paper. With increasing the mol ratio of SDS to the positive charges on the surface of APU NPs, the aqueous solution of APU NPs presents precipitation at pH 2, around stoichiometric SDS concentration, and then the precipitate dissociates with excess SDS to form more stable nanoparticles of ionomer complexes. Three stages of the complexation process are clearly shown by the pyrene I1/I3 variation of the complex systems, which only depends on the ratio of SDS/APU, and demonstrate that the process is dominated by electrostatic attraction and hydrophobic aggregation. PMID:17803299

  4. Effect of the Titanium Nanoparticle on the Quantum Chemical Characterization of the Liquid Sodium Nanofluid.

    PubMed

    Suzuki, Ai; Bonnaud, Patrick; Williams, Mark C; Selvam, Parasuraman; Aoki, Nobutoshi; Miyano, Masayuki; Miyamoto, Akira; Saito, Jun-ichi; Ara, Kuniaki

    2016-04-14

    Suspension state of a titanium nanoparticle in the liquid sodium was quantum chemically characterized by comparing physical characteristics, viz., electronic state, viscosity, and surface tension, with those of liquid sodium. The exterior titanium atoms on the topmost facet of the nanoparticle were found to constitute a stable Na-Ti layer, and the Brownian motion of a titanium nanoparticle could be seen in tandem with the surrounding sodium atoms. An electrochemical gradient due to the differences in electronegativity of both titanium and sodium causes electron flow from liquid sodium atoms to a titanium nanoparticle, Ti + Na → Ti(δ-) + Na(δ+), making the exothermic reaction possible. In other words, the titanium nanoparticle takes a role as electron-reservoir by withdrawing free electrons from sodium atoms and makes liquid sodium electropositive. The remaining electrons in the liquid sodium still make Na-Na bonds and become more stabilized. With increasing size of the titanium nanoparticle, the deeper electrostatic potential, the steeper electric field, and the larger Debye atmosphere are created in the electric double layer shell. Owing to electropositive sodium-to-sodium electrostatic repulsion between the external shells, naked titanium nanoparticles cannot approach each other, thus preventing the agglomeration. PMID:27008416

  5. Microbial selenite reduction with organic carbon and electrode as sole electron donor by a bacterium isolated from domestic wastewater.

    PubMed

    Nguyen, Van Khanh; Park, Younghyun; Yu, Jaecheul; Lee, Taeho

    2016-07-01

    Selenium is said to be multifaceted element because it is essential at a low concentration but very toxic at an elevated level. For the purpose of screening a potential microorganism for selenite bioremediation, we isolated a bacterium, named strain THL1, which could perform both heterotrophic selenite reduction, using organic carbons such as acetate, lactate, propionate, and butyrate as electron donors under microaerobic condition, and electrotrophic selenite reduction, using an electrode polarized at -0.3V (vs. standard hydrogen electrode) as the sole electron donor under anaerobic condition. This bacterium determined to be a new strain of the genus Cronobacter, could remove selenite with an efficiency of up to 100%. This study is the first demonstration on a pure culture could take up electrons from an electrode to perform selenite reduction. The selenium nanoparticles produced by microbial selenite reduction might be considered for recovery and use in the nanotechnology industry. PMID:27099943

  6. Effects of sodium selenite on c-Jun N-terminal kinase signalling pathway induced by oxidative stress in human chondrocytes and c-Jun N-terminal kinase expression in patients with Kashin-Beck disease, an endemic osteoarthritis.

    PubMed

    Dai, XiaoXia; Li, YuanYuan; Zhang, RongQiang; Kou, Yan; Mo, XiaoYan; Cao, JunLing; Xiong, YongMin

    2016-05-01

    The c-Jun N-terminal kinases (JNK) are members of the mitogen-activated protein kinase family and are activated by environmental stress. Se plays an important role in the biological pathways by forming selenoprotein. Selenoproteins have been shown to exhibit a variety of biological functions including antioxidant functions and maintaining cellular redox balance, and compromise of such important proteins would lead to oxidative stress and apoptosis. We examined the expression levels of JNK in Kashin-Beck disease (KBD) patients, tested the potential protective effects of sodium selenite on tert-butyl hydroperoxide (tBHP)-induced oxidative injury and apoptosis in human chondrocytes as well as its underlying mechanism in this study. We produced an oxidative damage model induced by tBHP in C28/I2 human chondrocytes to test the essential anti-apoptosis effects of Se in vitro. The results indicated that the expression level of phosphorylated JNK was significantly increased in KBD patients. Cell apoptosis was increased and molecule expressions of the JNK signalling pathway were activated in the tBHP-injured chondrocytes. Na2SeO3 protected against tBHP-induced oxidative stress and apoptosis in cells by increasing cell viability, reducing reactive oxygen species generation, increasing Glutathione peroxidase (GPx) activity and down-regulating the JNK pathway. These results demonstrate that apoptosis induced by tBHP in chondrocytes might be mediated via up-regulation of the JNK pathway; Na2SeO3 has an effect of anti-apoptosis by down-regulating the JNK signalling pathway. PMID:26948765

  7. Dietary selenate versus selenite for cattle, sheep, and horses.

    PubMed

    Podoll, K L; Bernard, J B; Ullrey, D E; DeBar, S R; Ku, P K; Magee, W T

    1992-06-01

    Food and Drug Administration regulations currently permit addition of .3 mg of Se per kilogram of diet for chickens, turkeys, ducks, swine, sheep, and cattle. However, field reports indicate that this level may not be adequate for ruminants in all situations. Because sodium selenite is the most common supplemental form and is known to be readily absorbed to particles or reduced to insoluble elemental Se or selenides in acid, anaerobic environments, studies were conducted with dairy cattle, sheep, and horses fed sodium selenate to determine whether Se from this source was more bioavailable than Se from sodium selenite. A 2-wk period of no Se supplementation was followed by 49 or 56 d of Se supplementation at .3 mg/kg of dietary DM. Serum Se concentrations and glutathione peroxidase (GSHPx) activities measured initially and periodically thereafter revealed no difference between Se forms in sheep and horses and only a small (P less than .05) advantage for selenate in supporting serum Se concentration in dairy cattle. Selenium concentrations in skeletal muscle and liver of sheep were not different between Se forms. Serum Se, but not GSHPx, increased with time, and .3 mg of supplemental Se per kilogram of dietary DM from either sodium selenate or sodium selenite supported normal serum Se concentrations in sheep, dairy cattle, and horses. PMID:1321804

  8. Transcriptional Response of Selenopolypeptide Genes and Selenocysteine Biosynthesis Machinery Genes in Escherichia coli during Selenite Reduction

    PubMed Central

    Tetteh, Antonia Y.; Sun, Katherine H.; Kittur, Farooqahmed S.; Ibeanu, Gordon C.

    2014-01-01

    Bacteria can reduce toxic selenite into less toxic, elemental selenium (Se0), but the mechanism on how bacterial cells reduce selenite at molecular level is still not clear. We used Escherichia coli strain K12, a common bacterial strain, as a model to study its growth response to sodium selenite (Na2SeO3) treatment and then used quantitative real-time PCR (qRT-PCR) to quantify transcript levels of three E. coli selenopolypeptide genes and a set of machinery genes for selenocysteine (SeCys) biosynthesis and incorporation into polypeptides, whose involvements in the selenite reduction are largely unknown. We determined that 5 mM Na2SeO3 treatment inhibited growth by ∼50% while 0.001 to 0.01 mM treatments stimulated cell growth by ∼30%. Under 50% inhibitory or 30% stimulatory Na2SeO3 concentration, selenopolypeptide genes (fdnG, fdoG, and fdhF) whose products require SeCys but not SeCys biosynthesis machinery genes were found to be induced ≥2-fold. In addition, one sulfur (S) metabolic gene iscS and two previously reported selenite-responsive genes sodA and gutS were also induced ≥2-fold under 50% inhibitory concentration. Our findings provide insight about the detoxification of selenite in E. coli via induction of these genes involved in the selenite reduction process. PMID:24839442

  9. Synthesis, structure, and characterization of two new polar sodium tungsten selenites: Na2(WO3)3(SeO3)·2H2O and Na6(W6O19)(SeO3)2.

    PubMed

    Nguyen, Sau Doan; Halasyamani, P Shiv

    2013-03-01

    Two new quaternary sodium tungsten selenites, Na2(WO3)3(SeO3)·2H2O (P31c) and Na6(W6O19)(SeO3)2 (C2), have been synthesized and characterized. The former exhibits a hexagonal tungsten oxide layered structure, whereas the latter has a one-dimensional "ribbon" structure. The layers and "ribbons" consist of distorted WO6 and asymmetric SeO3 polyhedra. The layers in Na2(WO3)3(SeO3)·2H2O and the "ribbons" in Na6(W6O19)(SeO3)2 are separated by Na(+) cations. Powder second-harmonic-generation (SHG) measurements on Na2(WO3)3(SeO3)·2H2O and Na6(W6O19)(SeO3)2 using 1064 nm radiation reveal SHG efficiencies of approximately 450× and 20× α-SiO2, respectively. Particle size versus SHG efficiency measurements indicate that the materials are type 1 non-phase-matchable. Converse piezoelectric measurements result in d33 values of approximately 23 and 12 pm/V, whereas pyroelectric measurements reveal coefficients of -0.41 and -1.10 μC/m(2)·K at 60 °C for Na2(WO3)3(SeO3)·2H2O and Na6(W6O19)(SeO3)2, respectively. Frequency-dependent polarization measurements confirm that the materials are nonferroelectric; i.e., the macroscopic polarization is not reversible, or "switchable". IR and UV-vis spectroscopy, thermogravimetric and differential thermal analysis measurements, and electron localization function calculations were also done for the materials. Crystal data: Na2(WO3)3(SeO3)·2H2O, trigonal, space group P31c (No. 159), a = 7.2595(6) Å, b = 7.2595(6) Å, c = 12.4867(13) Å, V = 569.89(9) Å(3), Z = 2; Na6(W6O19)(SeO3)2, monoclinic, space group C2 (No. 5), a = 42.169(8) Å, b = 7.2690(15) Å, c = 6.7494(13) Å, β = 98.48(3)°, V = 2046.2(7) Å(3), Z = 4. PMID:23425251

  10. Germinating Peanut (Arachis hypogaea L.) Seedlings Attenuated Selenite-Induced Toxicity by Activating the Antioxidant Enzymes and Mediating the Ascorbate-Glutathione Cycle.

    PubMed

    Wang, Guang; Zhang, Hong; Lai, Furao; Wu, Hui

    2016-02-17

    Selenite can enhance the selenium nutrition level of crops, but excessive selenite may be toxic to plant growth. To elucidate the mechanisms underlying the role of selenite in production and detoxification of oxidative toxicity, peanut seedlings were developed with sodium selenite (0, 3, and 6 mg/L). The effects of selenite on antioxidant capacity, transcript levels of antioxidant enzyme genes, and enzyme activities in hypocotyl were investigated. The CuZn-SOD, GSH-Px, GST, and APX gene expression levels and their enzyme activities in selenite treatments were 1.0-3.6-fold of the control. Selenite also significantly increased the glutathione and ascorbate concentrations by mediating the ascorbate-glutathione cycle, and the selenite-induced hydrogen peroxide may act as a second messenger in the signaling pathways. This work has revealed a complex antioxidative response to selenite in peanut seedling. Understanding these mechanisms may help future research in increasing selenite tolerance and selenium accumulation in peanut and other crops. PMID:26824138

  11. Hydrogen saline prevents selenite-induced cataract in rats

    PubMed Central

    Yang, Chun-xiao; Ding, Tian-bing

    2013-01-01

    Purpose The aim of this study was to investigate the potential antioxidative effect and mechanism for the protective effects of hydrogen saline on selenite-induced cataract in rats. Methods Sprague-Dawley rat pups were divided into the following groups: control (Group A), selenite induced (Group B), and selenite plus hydrogen saline treated (Group C). Rat pups in Groups B and C received a single subcutaneous injection of sodium selenite (25 μmol/kg bodyweight) on postnatal day 12. Group C also received an intraperitoneal injection of H2 saline (5 ml/kg bodyweight) daily from postnatal day 8 to postnatal day 17. The development of cataract was assessed weekly by slit-lamp examination for 2 weeks. After sacrifice, extricated lenses were analyzed for activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glutathione S-transferase, levels of malondialdehyde, reduced glutathione (GSH), and total sulfhydryl contents. Results The magnitude of lens opacification in Group B was significantly higher than in Group A (p<0.05), while Group C had less opacification than Group B (p<0.05). Compared with Group B, the mean activities of the antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glutathione S-transferase, levels of GSH, and total sulfhydryl contents were higher, whereas the level of malondialdehyde was lower following treatment with hydrogen saline(p<0.05). Conclusions This is an initial report showing that hydrogen saline can prevent selenite-induced cataract in rats. It acts via maintaining antioxidant enzymes and GSH, protecting the sulfhydryl group, and inhibiting lipid peroxidation. PMID:23922487

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  13. Antibacterial silver nanoparticles in polyvinyl alcohol/sodium alginate blend produced by gamma irradiation.

    PubMed

    Eghbalifam, Naeimeh; Frounchi, Masoud; Dadbin, Susan

    2015-09-01

    Polyvinyl alcohol/sodium alginate/nano silver (PVA/SA/Ag) composite films were made by solution casting method. Gamma irradiation was used to synthesize silver nanoparticles in situ via reduction of silver nitrate without using harmful chemical agents for biomedical applications. UV-vis and XRD results demonstrated that spherical silver nanoparticles were produced even at low irradiation dose of 5 kGy. By increasing irradiation dose, more nanoparticles were synthesized while no PVA hydrogel was formed up to 15 kGy. Also the size of nanoparticles was reduced with increasing gamma dose evidenced by higher release rate of silver nanoparticles in lukewarm water and SEM images. Comparing SEM images with DLS results indicated good performance of PVA/SA as an efficient stabilizer in preventing agglomeration of the silver nanoparticles. Good miscibility of polyvinyl alcohol and sodium alginate observed on the SEM images was supported with FTIR spectroscopy. Upon addition of sodium alginate to polyvinyl alcohol and increasing silver nanoparticles, the melting peak shifted to lower temperature and crystallinity percent was decreased. Addition of sodium alginate led to remarkable increase in rigidity of PVA. The composites exhibited strong antibacterial activity against Staphylococcus aureus and Escherichia coli even at very low level of silver nanoparticles. PMID:26123816

  14. Reduction of organic and inorganic selenium compounds by the edible medicinal basidiomycete Lentinula edodes and the accumulation of elemental selenium nanoparticles in its mycelium.

    PubMed

    Vetchinkina, Elena; Loshchinina, Ekaterina; Kursky, Viktor; Nikitina, Valentina

    2013-12-01

    We report for the first time that the medicinal basidiomycete Lentinula edodes can reduce selenium from inorganic sodium selenite (Se(IV)) and the organoselenium compound 1,5-diphenyl-3-selenopentanedione-1,5 (DAPS-25) to the elemental state, forming spherical nanoparticles. Submerged cultivation of the fungus with sodium selenite or with DAPS-25 produced an intense red coloration of L. edodes mycelial hyphae, indicating accumulation of elemental selenium (Se(0)) in a red modification. Several methods, including transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS), and X-ray fluorescence, were used to show that red Se(0) accumulated intracellularly in the fungal hyphae as electron-dense nanoparticles with a diameter of 180.51±16.82 nm. Under designated cultivation conditions, shiitake did not reduce selenium from sodium selenate (Se(VI)). PMID:24385361

  15. Polyelectrolyte complex nanoparticles from cationised gelatin and sodium alginate for curcumin delivery.

    PubMed

    Sarika, P R; James, Nirmala Rachel

    2016-09-01

    Self assembled hybrid polyelectrolyte complex (PEC) nanoparticles are prepared from cationically modified gelatin and sodium alginate (Alg) by electrostatic complexation between the polymers. Cationised gelatin (CG) is prepared by the reaction of gelatin with ethylenediamine. Structural changes in gelatin, after modification with ethylenediamine are investigated by XRD and (1)H NMR spectroscopy. Hybrid polyelectrolyte nanoparticles, labeled CG/Alg, are prepared by simple mixing of CG and Alg. CG/Alg complex shows spherical morphology as confirmed by scanning electron microscopy. These polyelectrolyte complex nanoparticles can be used for the encapsulation and delivery of natural antioxidant curcumin to carcinoma cells. CG/Alg nanoparticles show curcumin encapsulation efficiency of 69% and exhibit sustained release of curcumin in vitro. Anticancer activity of curcumin loaded CG/Alg nanoparticles towards MCF-7 cells is disclosed by MTT assay. Intracellular uptake of the drug encapsulated nanoparticles is confirmed by fluorescent imaging. PMID:27185149

  16. Selenopeptides and elemental selenium in Thunbergia alata after exposure to selenite: quantification method for elemental selenium.

    PubMed

    Aborode, Fatai Adigun; Raab, Andrea; Foster, Simon; Lombi, Enzo; Maher, William; Krupp, Eva M; Feldmann, Joerg

    2015-07-01

    Three month old Thunbergia alata were exposed for 13 days to 10 μM selenite to determine the biotransformation of selenite in their roots. Selenium in formic acid extracts (80 ± 3%) was present as selenopeptides with Se-S bonds and selenium-PC complexes (selenocysteinyl-2-3-dihydroxypropionyl-glutathione, seleno-phytochelatin2, seleno-di-glutathione). An analytical method using HPLC-ICPMS to detect and quantify elemental selenium in roots of T. alata plants using sodium sulfite to quantitatively transform elemental selenium to selenosulfate was also developed. Elemental selenium was determined as 18 ± 4% of the total selenium in the roots which was equivalent to the selenium not extracted using formic acid extraction. The results are in an agreement with the XAS measurements of the exposed roots which showed no occurrence of selenite or selenate but a mixture of selenocysteine and elemental selenium. PMID:25747595

  17. Characterization of Conventional One-Step Sodium Thiosulfate Facilitated Gold Nanoparticle Synthesis

    NASA Astrophysics Data System (ADS)

    Saverot, Scott-Eugene; Reese, Laura M.; Cimini, Daniela; Vikesland, Peter J.; Bickford, Lissett Ramirez

    2015-05-01

    Gold-gold sulfide nanoparticles are of interest for drug delivery, biomedical imaging, and photothermal therapy applications due to a facile synthesis method resulting in small particles with high near-infrared (NIR) absorption efficiency. Previous studies suggest that the NIR sensitivity of these nanoparticles was due to hexagonally shaped metal-coated dielectric nanoparticles that consist of a gold sulfide core and gold shell. Here, we illustrate that the conventional synthesis procedure results in the formation of polydisperse samples of icosahedral gold particles, gold nanoplates, and small gold spheres. Importantly, through compositional analysis, via UV/vis absorption spectrophotometry, transmission electron microscopy (TEM), and energy dispersive x-ray spectroscopy (EDS), we show that all of the nanoparticles exhibit identical face center cubic (FCC) gold crystalline structures, thus suggesting that sulfide is not present in the final fabricated nanoparticles. We show that icosahedrally shaped nanoparticles result in a blue-shifted absorbance, with a peak in the visible range. Alternatively, the nanoplate nanoparticles result in the characteristic NIR absorbance peak. Thus, we report that the NIR-contributing species in conventional gold-gold sulfide formulations are nanoplates that are comprised entirely of gold. Furthermore, polydisperse gold nanoparticle samples produced by the traditional one-step reduction of HAuCl4 by sodium thiosulfate show increased in vitro toxicity, compared to isolated and more homogeneous constituent samples. This result exemplifies the importance of developing monodisperse nanoparticle formulations that are well characterized in order to expedite the development of clinically beneficial nanomaterials.

  18. Selenite cataracts: Activation of endoplasmic reticulum stress and loss of Nrf2/Keap1-dependent stress protection

    PubMed Central

    Palsamy, Periyasamy; Bidasee, Keshore R.; Shinohara, Toshimichi

    2014-01-01

    Cataract-induced by sodium selenite in suckling rats is one of the suitable animal models to study the basic mechanism of human cataracts formation. The aim of this present investigation is to study the endoplasmic reticulum (ER) stress-mediated activation of unfolded protein response (UPR), overproduction of reactive oxygen species (ROS), and suppression of Nrf2/Keap1-dependent antioxidant protection through endoplasmic reticulum-associated degradation (ERAD) pathway and Keap1 promoter DNA demethylation in human lens epithelial cells (HLECs) treated with sodium selenite. Lenses enucleated from sodium selenite injected rats generated overproduction of ROS in lens epithelial cells and newly formed lens fiber cells resulting in massive lens epithelial cells death after 1–5 days. All these lenses developed nuclear cataracts after 4–5 days. Sodium selenite treated HLECs induced ER stress and activated the UPR leading to release of Ca2+ from ER, ROS overproduction and finally HLECs death. Sodium selenite also activated the mRNA expressions of passive DNA demethylation pathway enzymes such as Dnmt1, Dnmt3a, and Dnmt3b, and active DNA demethylation pathway enzyme, Tet1 leading to DNA demethylation in the Keap1 promoter of HLECs. This demethylated Keap1 promoter results in overexpression of Keap1 mRNA and protein. Overexpression Keap1 protein suppresses the Nrf2 protein through ERAD leading to suppression of Nrf2/Keap1 dependent antioxidant protection in the HLECs treated with sodium selenite. As an outcome, the cellular redox status is altered towards lens oxidation and results in cataract formation. PMID:24997453

  19. Foliar application of selenite and selenate to potato (Solanum tuberosum): effect of a ligand agent on selenium content of tubers.

    PubMed

    Poggi, V; Arcioni, A; Filippini, P; Pifferi, P G

    2000-10-01

    The effect of a foliar spray of selenium on potatoes was investigated for 2 years. Amounts of 0, 50, and 150 g of Se ha(-)(1) were applied both as sodium selenate and as sodium selenite in water, either pure or with the addition of 0.15% of soluble leonardite as a source of humic acids (pH 7). Tuber selenium concentration increased with the application levels, both with sodium selenate and with sodium selenite, when only aqueous solutions were used. When humic acids were added, the tuber selenium level rose more markedly after the application of sodium selenate as compared to the case of the aqueous solutions; however, in the case of sodium selenite, the level showed a large increase only after the application of 50 g of Se ha(-)(1). Kinetics showed that humic acids raised the selenate availability, but no differences were found in the distribution of selenium in the tuber fractions. Foliar application of selenium with humic acids was proven to be a good way to increase the selenium content of potatoes, but the assimilation process of selenium was simpler with selenate than with selenite. PMID:11052729

  20. Discontinuous variation of the surface plasmon linewidth of small sodium nanoparticles with electron temperatures

    NASA Astrophysics Data System (ADS)

    Wang, Guozhong; Zheng, Yizhuang; Zi, Jian

    2015-05-01

    We found a novel behavior of the surface plasmon linewidth of small sodium nanoparticles, which monotonically decreases with the electron temperature and bears a sudden drop or rise at high electron temperatures. Our calculation is based on the model constructed by splitting the total Hamiltonian of all valence electrons of a metallic nanoparticle into two sub-Hamiltonians and the coupling between them. This novel behavior of the surface plasma resonance linewidth can be verified by pump-probe femtosecond spectroscopy experiments and is able to take place for metallic particles with sizes less than few nanometers. In addition, we propose that it is the size uncertainty of small nanoparticles that yields the intrinsic linewidth of the surface plasmon resonance, which is supported by experimental and theoretical results of nanoparticles Na8 and Na20.

  1. Investigating different mechanisms for biogenic selenite transformations: Geobacter sulfurreducens, Shewanella oneidensis and Veillonella atypica

    USGS Publications Warehouse

    Pearce, C.I.; Pattrick, R.A.D.; Law, N.; Charnock, J.M.; Coker, V.S.; Fellowes, J.W.; Oremland, R.S.; Lloyd, J.R.

    2009-01-01

    The metal-reducing bacteria Geobacter sulfurreducens, Shewanella oneidensis and Veillonella atypica, use different mechanisms to transform toxic, bioavailable sodium selenite to less toxic, non-mobile elemental selenium and then to selenide in anaerobic environments, offering the potential for in situ and ex situ bioremediation of contaminated soils, sediments, industrial effluents, and agricultural drainage waters. The products of these reductive transformations depend on both the organism involved and the reduction conditions employed, in terms of electron donor and exogenous extracellular redox mediator. The intermediary phase involves the precipitation of elemental selenium nanospheres and the potential role of proteins in the formation of these structures is discussed. The bionanomineral phases produced during these transformations, including both elemental selenium nanospheres and metal selenide nanoparticles, have catalytic, semiconducting and light-emitting properties, which may have unique applications in the realm of nanophotonics. This research offers the potential to combine remediation of contaminants with the development of environmentally friendly manufacturing pathways for novel bionanominerals. ?? 2009 Taylor & Francis.

  2. Polyaniline:poly(sodium 4-styrenesulfonate)-stabilized gold nanoparticles as efficient, versatile catalysts

    NASA Astrophysics Data System (ADS)

    Liu, Xiaojun; Li, Ligui; Ye, Meixia; Xue, Yang; Chen, Shaowei

    2014-04-01

    Gold nanoparticles were stabilized by a polyaniline:poly(sodium 4-styrenesulfonate) (PANI:PSS) matrix and readily dispersed in water over a wide range of pH. In contrast to nanoparticles passivated by alkanethiolates that formed a compact capping layer on the nanoparticle surface, the PANI:PSS-Au nanocomposites exhibited apparent catalytic activity in the reduction of 4-nitrophenol in the presence of excessive NaBH4, with reasonably good recyclability, which was likely due to the large accessible surface area. In addition, the PANI:PSS-Au nanocomposites also demonstrated peroxidase-like catalytic activity as evidenced by the colorimetric detection of H2O2 and glucose with PANI:PSS-Au as the enzymatic mimic. The present method may find potential applications in the design, preparation and functionalization of noble nanoparticles as efficient, versatile, and recyclable catalysts with high dispersibility and stability in aqueous media.Gold nanoparticles were stabilized by a polyaniline:poly(sodium 4-styrenesulfonate) (PANI:PSS) matrix and readily dispersed in water over a wide range of pH. In contrast to nanoparticles passivated by alkanethiolates that formed a compact capping layer on the nanoparticle surface, the PANI:PSS-Au nanocomposites exhibited apparent catalytic activity in the reduction of 4-nitrophenol in the presence of excessive NaBH4, with reasonably good recyclability, which was likely due to the large accessible surface area. In addition, the PANI:PSS-Au nanocomposites also demonstrated peroxidase-like catalytic activity as evidenced by the colorimetric detection of H2O2 and glucose with PANI:PSS-Au as the enzymatic mimic. The present method may find potential applications in the design, preparation and functionalization of noble nanoparticles as efficient, versatile, and recyclable catalysts with high dispersibility and stability in aqueous media. Electronic supplementary information (ESI) available: Structural scheme, HRTEM micrograph, UV

  3. Effect of selenite and selenate on plant uptake of cadmium by maize (zea mays)

    SciTech Connect

    Shanker, K.; Mishra, S.; Srivastava, S.

    1996-03-01

    Selenium has been reported to confer tolerance to toxicity of heavy metals including cadmium, a highly toxic and non essential heavy metal, which enters the food chain via plant uptake from soils. Selenium reduces availability of cadmium to plants along with other aspects of its toxicokinetics. When plants are supplied with selenite, selenium concentrations in the xylem exudate are lower than selenate. Most of the selenate was transported as selenate and unidentified organic Se compounds. In contrast, Se distribution among various Se fractions within plants does not depend significantly on whether selenite or selenate was used. Selenium has a strong tendency to form complexes with heavy metals like Cd, Hg, Ag and Tl. It has been suggested that the protective effects of selenium are due to the formation of non toxic Se-metal complexes, although the mechanism by which this protective effect is exerted remains unclear. Studies on the effect of selenium (selenite) and cadmium additions to the soil on their concentrations in lettuce and wheat has indicated the role of selenite in reduction of cadmium uptake. The cletoxifying effect of sodium selenite on cadmium ion in the freshwater fish Potyacuthus cupanus has been reported. The discovery that an element like selenium counteracts the toxicity, chemical carcinogenesis and reduces the plant uptake of other toxic metals, highlights the possibility of existence of a Se-metal interaction mechanism in soil plant systems. The uptake and translocation of root-absorbed chromium supplied through irrigation in the trivalent and hexavalant states in various parts of the onion plant (Allium cepa) grown in soil and sand culture has been recently reported by us. In continuation of that, this preliminary report describes the effect of selenite and selenate pretreatment on the uptake of cadmium in the maize plant (Zea mays).

  4. Chemical forms of selenium in rat tissues after administration of selenite or selenomethionine

    SciTech Connect

    Beilstein, M.A.; Whanger, P.D.

    1986-09-01

    The chemical forms of selenium (Se) were determined in erythrocyte and liver proteins after injection of /sup 75/Se as either sodium selenite or selenomethionine (Se-Met) in male weanling rats. Gel-filtration chromatography (Sephadex G-150) of erythrocyte lysate revealed labeling of four fractions corresponding to void volume proteins, glutathione peroxidase (GPx), hemoglobin (Hb) and low-molecular-weight materials. Acid hydrolysates of erythrocyte protein fractions and whole liver were analyzed by ion-exchange chromatography (Dionex DC6A). Void volume proteins contained principally selenocysteine (/sup 75/Se-Cys) in (/sup 75/Se)selenite-injected animals. This material contained both /sup 75/Se-Met and /sup 75/Se-Cys 1 d postinjection in /sup 75/Se-Met-injected animals, but primarily /sup 75/Se-Cys at 20 d afterwards. GPx contained /sup 75/Se as /sup 75/Se-Cys regardless of the selenium compound injected. Hb of /sup 75/Se-Met-injected animals contained principally /sup 75/Se-Met at both 1 and 20 d postinjection. In (/sup 75/Se)selenite-injected animals, /sup 75/Se was present in hemoglobin as two unidentified forms. In acid hydrolysates of whole liver /sup 75/Se was recovered principally as /sup 75/Se-Cys from animals injected with (/sup 75/Se)selenite. For animals injected with /sup 75/Se-Met, liver /sup 75/Se was present initially as /sup 75/Se-Met, but after 5 d the majority of liver /sup 75/Se was as Se-Cys. No differences were found in deposition of /sup 75/Se in liver, kidney, testes, erythrocytes or plasma in rats injected with labeled selenite or Se-Met, but a significantly greater retention was found in muscle of Se-Met-injected rats as compared to those given selenite.

  5. Sodium doping and reactivity in pure and mixed ice nanoparticles*

    NASA Astrophysics Data System (ADS)

    Lengyel, Jozef; Pysanenko, Andriy; Rubovič, Peter; Fárník, Michal

    2015-12-01

    Doping of clusters by sodium atoms and subsequent photoionization (NaPI) is used as a fragmentation-free cluster ionization method. Here we investigate different clusters using NaPI and electron ionization (EI) with a reflectron time-of-flight mass spectrometer (RTOF). The mass spectra of the same clusters ionized by NaPI and EI reveal significant differences which point to Na reactivity in the clusters. First, we discuss mixed X M ·(H2O) N (X = HNO3, N2O) clusters where reactions between Na and molecules X leads to the "cluster invisibility" for the NaPI method. Second, mixed (NH3) M ·(H2O) N clusters are observed by both methods, but they reveal different cluster compositions, and the mass spectra suggest that neither the EI nor the NaPI spectrum corresponds exactly to the neutral cluster distribution. Finally, we discuss the reactions of Na in pure water clusters as a function of the number of Na atoms doped into the clusters. In summary, we present experimental evidence that the NaPI method in the present cases does not reveal the size and composition of the neutral clusters. A detailed understanding of Na reactivity in the clusters is needed for its application as a fragmentation-free cluster ionization method. Besides, we introduce the combination of NaPI and EI as a new tool to investigate the sodium reactivity in clusters and aerosol particles.

  6. Nuclear magnetic resonance investigation of metallic sodium nanoparticles in porous glass

    NASA Astrophysics Data System (ADS)

    Uskov, A. V.; Nefedov, D. Yu.; Charnaya, E. V.; Shevchenko, E. V.; Haase, J.; Michel, D.; Kumzerov, Yu. A.; Fokin, A. V.; Bugaev, A. S.

    2016-06-01

    Sodium nanoparticles embedded in porous glass have been studied by NMR. The measurements have been carried out on pulse spectrometers in magnetic fields of 9.4 and 17.6 T in a wide temperature range. Changes in the magnitude and temperature dependence of the 23Na Knight shift with respect to those in bulk sodium have been discovered. An additional component of the NMR line shifted to high frequencies has been observed in the temperature range from 240 to 100 K. Investigation of the specific heat has revealed a considerable decrease in the melting and crystallization temperatures of sodium under nanoconfinement, which were not accompanied by abrupt changes in the Knight shift.

  7. Biocompatible transferrin-conjugated sodium hexametaphosphate-stabilized gold nanoparticles: synthesis, characterization, cytotoxicity and cellular uptake

    NASA Astrophysics Data System (ADS)

    Parab, Harshala J.; Huang, Jing-Hong; Lai, Tsung-Ching; Jan, Yi-Hua; Liu, Ru-Shi; Wang, Jui-Ling; Hsiao, Michael; Chen, Chung-Hsuan; Hwu, Yeu-Kuang; Tsai, Din Ping; Chuang, Shih-Yi; Pang, Jong-Hwei S.

    2011-09-01

    The feasibility of using gold nanoparticles (AuNPs) for biomedical applications has led to considerable interest in the development of novel synthetic protocols and surface modification strategies for AuNPs to produce biocompatible molecular probes. This investigation is, to our knowledge, the first to elucidate the synthesis and characterization of sodium hexametaphosphate (HMP)-stabilized gold nanoparticles (Au-HMP) in an aqueous medium. The role of HMP, a food additive, as a polymeric stabilizing and protecting agent for AuNPs is elucidated. The surface modification of Au-HMP nanoparticles was carried out using polyethylene glycol and transferrin to produce molecular probes for possible clinical applications. In vitro cell viability studies performed using as-synthesized Au-HMP nanoparticles and their surface-modified counterparts reveal the biocompatibility of the nanoparticles. The transferrin-conjugated nanoparticles have significantly higher cellular uptake in J5 cells (liver cancer cells) than control cells (oral mucosa fibroblast cells), as determined by inductively coupled plasma mass spectrometry. This study demonstrates the possibility of using an inexpensive and non-toxic food additive, HMP, as a stabilizer in the large-scale generation of biocompatible and monodispersed AuNPs, which may have future diagnostic and therapeutic applications.

  8. Electrochemical investigation of tryptophan at gold nanoparticles modified electrode in the presence of sodium dodecylbenzene sulfonate.

    PubMed

    Li, Chunya; Ya, Yu; Zhan, Guoqing

    2010-03-01

    Glassy carbon electrode modified with gold nanoparticles was prepared using electrodeposition at constant potential of -0.20V, and characterized with scanning electron microscopy and electrochemical techniques. Voltammetry was employed to study the electrochemical behaviors of tryptophan at the Au nanoparticles modified electrode in the presence of sodium dodecylbenzene sulfonate. The results showed that the Au nanoparticles modified electrode had good performance for the electrochemical oxidation of tryptophan. Compared with the unmodified electrode, the Au nanoparticles modified electrode improved the adsorption of tryptophan on the nanointerface and amplified its current response. The oxidation peak potential showed a negative shift of 50mV in the presence of sodium dodecylbenzene sulfonate indicating that the electron transfer between the electrode and bulk solution of tryptophan was facilitated. Experimental parameters for tryptophan determination, such as deposition time, pH value, and accumulation conditions have been optimized. The oxidation peak current was linearly dependent on the tryptophan concentration and a calibration curve was obtained in the concentration range of 9.0x10(-8)molL(-1) to 5.0x10(-5)molL(-1) with detection limit of 8.0x10(-8)molL(-1) (S/N=3). PMID:20015621

  9. Catalytic hydrodechlorination of 1,2-dichloroethane using copper nanoparticles under reduction conditions of sodium borohydride.

    PubMed

    Huang, Chang-Chieh; Lo, Shang-Lien; Tsai, Shin-Mu; Lien, Hsing-Lung

    2011-09-01

    1,2-Dichloroethane (1,2-DCA) is a raw material used for the manufacture of vinyl chloride monomer (VCM) and therefore has very often been detected in the groundwater nearby the VCM manufacturing plant. Zero-valent iron (ZVI) is capable of degrading a wide array of highly chlorinated contaminants; however, the reactivity of ZVI towards 1,2-DCA is very low. In this study, zero-valent copper nanoparticles have been synthesized for effective dechlorination of 1,2-DCA under reduction conditions of sodium borohydride. Copper nanoparticles consisted of mainly metallic copper (Cu(0)) with small amounts of cuprous oxide (Cu(2)O). They have surface areas of about 19.0 m(2) g(-1) and an average diameter of 15 nm. Batch experiments were conducted to test the effectiveness of copper nanoparticles for 1,2-DCA degradation using sodium borohydride as electron donors where the ORP was measured as -1100 mV. More than 80% of 1,2-DCA (30 mg L(-1)) was rapidly degraded within 2 h in the presence of both copper nanoparticles (2.5 g L(-1)) and borohydride (25 mM). No reduction of 1,2-DCA was observed when the system contained either copper nanoparticles alone or borohydride alone. The degradation intermediates included ethane and ethylene accounting for 79% and ∼1.5% of the 1,2-DCA lost, respectively. Potential environmental applications can be achieved by immobilizing copper nanoparticles onto the surface of reducing metals to form a reactive bimetallic structure. PMID:21850296

  10. UVA mediated synthesis of gold nanoparticles in pharmaceutical-grade heparin sodium solutions

    NASA Astrophysics Data System (ADS)

    Rodríguez-Torres, M. Del P.; Diaz-Torres, L. A.; Olmos-López, M.; Salas, P.; Gutiérrez, Clara

    2013-09-01

    A photochemical-based method in which UVA light (λ=366 nm) is used for synthesizing gold nanoparticles is presented by irradiating gold (III) chloride hydrate (HAuCl4) in the presence of pharmaceutical-grade heparin sodium (PGHEP) as a reducing and stabilizing agent in aqueous solution. Different HAuCl4 to PGHEP concentration ratios were exposed to UVA for up to seven hours. The as-synthesized nanoparticles were characterized by UV-VIS and Raman spectroscopy, transmission electron microscopy (TEM), and pH measurements. The synthesized AuNPs present spherical as well as anisotropic shapes, such as oval, triangular, hexagonal sheets, rods, and some other faceted forms, with dimensions ranging from 20 nm to 300 nm. All obtained products show good temporal stability in solution. Surface plasmons differ when varying HAuCl4 to PGHEP concentration ratio. The obtained samples exhibit two absorption peaks, one in the region between 500-600 nm, and another one in the near-IR between 900-1200 nm; both peaks shift to longer wavelengths and increase their absorption intensity as the HAuCl4 to PGHEP concentration ratio increase. TEM images show the change in nanoparticles yield as well as the shape and sizes change depending on HAuCl4 to PGHEP concentration ratio variation. Ph measurements suggest that acidic media promote anisotropic nanoparticle formation. Raman spectroscopy was used to find out which heparin sodium main groups attached to the nanoparticles surface, and in what amount. In summary, it is found that when modifying the reactants concentrations and keeping the UV exposition time as the only fixed parameter, different nanoparticles with distinctive characteristics can be attained.

  11. Selenite metabolism in total parenteral nutrition (TPN)

    SciTech Connect

    Sitrin, M.D.; Ting, B.T.G.; Hazell, T.; Janghorbani, M. )

    1989-02-01

    Patients on long-term TPN commonly receive selenite to prevent selenium (Se) deficiency. Little information is available concerning the effect of chronic selenite supplementation on Se metabolism. In this study, we have used {sup 74}Se to examine selenite metabolism in 2 home TPN patents, one on selenite and one on no supplementation. Afte rcollection of baseline blood and urine samples, 80 {mu}g of selenite enriched with {sup 74}Se was added to the TPN formula, and infused over 12 hrs. Daily urine output was collected for 10 d. Inductively coupled plasma mass spectrometry was used to determine the isotope ratios of {sup 74}Se to {sup 77}Se, and {sup 74}Se to {sup 82}Se (added in vitro and an internal standard) in urine. Cumulative {sup 74}Se retention and an apparent selenite exchangeable pool size were calculated using standard isotope dilution equations. The unsupplemented TPN patient had biochemical Se deficiency, with decreased plasma Se (1 ng/ml) urine Se (1 ug/d) and red cell and plasma glutathione peroxidase activity (GSH-Px). Retention of {sup 74}Se was very high, 93% at 10 d, and the pool size was extremely low, 566 ug at 10 d. The supplemented patent had normal plasma and urine Se levels and plasma and red cell GSH-Px. {sup 74}Se retention was very poor, only 42% at 1 d and 38% at 10 d. The Se pool size increased rapidly over time, reaching 12000 ug at 10 d. In contrast, our previous studies in normal subjects consuming dietary orgaic Se showed a selenite retention of 85-90% at 1 d and 70-80% at 10 d, and a pool size of 6000-8000 ug at 10 day. Conclusions: 1. Using {sup 74}Se, differences in Se retention and pool size can easily be detected in Se deficient vs replete TPN patients 2. Chronic supplementation with selenite appears to result in decreased {sup 74}Se retention and an expanded selenite exchangeable pool in comparison with normals consuming dietary Se.

  12. Toxicity and accumulation of selenite in four microalgae

    NASA Astrophysics Data System (ADS)

    Dazhi, Wang; Zhaodi, Cheng; Shaojing, Li; Yahui, Gao

    2003-09-01

    The toxicity and bioaccumulation of selenite in four microalgae, Spirulina platensis, Dunaliella salina, Dunaliella bardawill and Phaeodactylum tricornutum cultured in the presence of selenite were investigated. Lower concentrations of selenite were generally nontoxic and frequently stimulated algal growth, while higher concentrations of selenite inhibited algal growth. Selenite was more toxic to D. salina and D. bardawill than to S. platensis and P. Tricornutum. All algae cultured in selenite were able to incorporate Se to different degrees, which depended on algal species. The distributions of selenite among intracellular macromolecular compounds were different among algal species: most of the selenite was associated with proteins in S. platensis, D. salina and D. bardawill, while most of the selenite was associated with lipids in P. tricornutum, which reflected the physiological differences among the algae. These observations suggest that algae are able to accumulate selenite and bind it with intracellular macromolecular compounds when exposed to high concentration of selenite. This may represent a form of storage or detoxification of selenite by the algae.

  13. pH-Responsive PLGA Nanoparticle for Controlled Payload Delivery of Diclofenac Sodium.

    PubMed

    Khanal, Shalil; Adhikari, Udhab; Rijal, Nava P; Bhattarai, Shanta R; Sankar, Jagannathan; Bhattarai, Narayan

    2016-01-01

    Poly(lactic-co-glycolic acid) (PLGA) based nanoparticles have gained increasing attention in delivery applications due to their capability for controlled drug release characteristics, biocompatibility, and tunable mechanical, as well as degradation, properties. However, thorough study is always required while evaluating potential toxicity of the particles from dose dumping, inconsistent release and drug-polymer interactions. In this research, we developed PLGA nanoparticles modified by chitosan (CS), a cationic and pH responsive polysaccharide that bears repetitive amine groups in its backbone. We used a model drug, diclofenac sodium (DS), a nonsteroidal anti-inflammatory drug (NSAID), to study the drug loading and release characteristics. PLGA nanoparticles were synthesized by double-emulsion solvent evaporation technique. The nanoparticles were evaluated based on their particle size, surface charge, entrapment efficacy, and effect of pH in drug release profile. About 390-420 nm of average diameters and uniform morphology of the particles were confirmed by scanning electron microscope (SEM) imaging and dynamic light scattering (DLS) measurement. Chitosan coating over PLGA surface was confirmed by FTIR and DLS. Drug entrapment efficacy was up to 52%. Chitosan coated PLGA showed a pH responsive drug release in in vitro. The release was about 45% more at pH 5.5 than at pH 7.4. The results of our study indicated the development of chitosan coating over PLGA nanoparticle for pH dependent controlled release DS drug for therapeutic applications. PMID:27490577

  14. Alendronate Sodium as Enteric Coated Solid Lipid Nanoparticles; Preparation, Optimization, and In Vivo Evaluation to Enhance Its Oral Bioavailability

    PubMed Central

    Hosny, Khaled Mohamed

    2016-01-01

    Treatment of osteoporosis with alendronate sodium has several challenges. The first challenge is the low bioavailability. The second main challenge is side effects, which include oesophageal ulceration. The aim of this research was to reformulate alendronate sodium as enteric coated solid lipid nanoparticles in order to enhance its bioavailability, and preventing the free alendronate sodium from coming into direct contact with the gastrointestinal mucosa, and thereby reducing the possibility of side effects. Enteric coated solid lipid nanoparticles were prepared according to the Box-Behnken design employing Design expert® software, and characterized for size, morphology, and entrapment efficiency. The optimized formula was coated with an Eudragit S100 and evaluated for drug release in acidic and basic media, stability studies and pharmacokinetic evaluations on rabbits. The results indicated that, using Derringer's desirability functional tool for optimization, the highest entrapment efficiency value of 74.3% and the smallest size value of 98 nm were predicted under optimum conditions with a desirability value of 0.917. The optimized nanoparticles released alendronate sodium only at an alkaline pH. The pharmacokinetic evaluation revealed that alendronate sodium bioavailability was enhanced by more than 7.4-fold in rabbits. In conclusion, enteric coated solid lipid nanoparticles is a promising formula for the delivery of alendronate sodium, eliminating its oesophageal side effects and enhancing its bioavailability. PMID:27148747

  15. Effect of selenite on T-cell mitogenesis: contribution of ROS production and apoptosis signal-regulating kinase 1.

    PubMed

    Ueno, Hitoshi; Kajihara, Hitomi; Nakamura, Hajime; Okuno, Tomofumi; Sakazaki, Fumitoshi; Arakawa, Tomohiro; Ogino, Hirofumi; Nakamuro, Katsuhiko; Yodoi, Junji

    2014-01-01

    Although supplementation with the selenocompound, sodium selenite has been shown to stimulate the concanavalin A-induced T-cell mitogenic response, the mechanisms responsible remain unclear. This study was conducted to evaluate the relationships between the induction of apoptosis, formation of tumor necrosis factor (TNF)-alpha and reactive oxygen species (ROS), activation of apoptosis signal-regulating kinase (ASK) 1 and the thioredoxin (Trx) system when mitogenesis was stimulated by selenite. TNF-alpha was dose-dependently released by mouse splenocytes treated with selenite, and apoptosis was induced when TNF-alpha was added at the indicated concentrations. However, supplementation with selenite at low concentrations inhibited the accumulation of ROS with the increased expression of Trx reductase 1 and induction of apoptosis in wild-type splenocytes, and also at high concentrations in Trx-1-transgenic mouse splenocytes. The suppression of apoptosis was accompanied by a decrease in the expression of phospho-ASK1. These results suggest that the stimulation of T-cell mitogenesis by selenite may be partly attributed to the inhibited accumulation of ROS due to a reduced Trx-1/TR1 system, the inactivation of ASK1, and the suppression of apoptosis. PMID:25087957

  16. Silver nanoparticle toxicity is related to coating materials and disruption of sodium concentration regulation.

    PubMed

    Kwok, Kevin W H; Dong, Wu; Marinakos, Stella M; Liu, Jie; Chilkoti, Ashutosh; Wiesner, Mark R; Chernick, Melissa; Hinton, David E

    2016-11-01

    Silver nanoparticles (AgNPs) have been increasingly commercialized and their release into the environment is imminent. Toxicity of AgNP has been studied with a wide spectrum of organisms, yet the mechanism of toxicity remains largely unknown. This study systematically compared toxicity of 10 AgNPs of different particle diameters and coatings to Japanese medaka (Oryzias latipes) larvae to understand how characteristics of AgNP relate to toxicity. Dissolution of AgNPs was largely dependent on particle size, but their aggregation behavior and toxicity were more dependent on coating materials. 96 h lethal concentration 50% (LC50) values correlated with AgNP aggregate size rather than size of individual nanoparticles. Of the AgNPs studied, the dissolved Ag concentration in the test suspensions did not account for all of the observed toxicity, indicating the role of NP-specific characteristics in resultant toxicity. Exposure to AgNP led to decrease of sodium concentration in the tissue and increased expression of Na(+)/K(+ )ATPase. Gene expression patterns also suggested that toxicity was related to disruption of sodium regulation and not to oxidative stress. PMID:27345576

  17. Preparation and application of crosslinked poly(sodium acrylate)--coated magnetite nanoparticles as corrosion inhibitors for carbon steel alloy.

    PubMed

    Atta, Ayman M; El-Mahdy, Gamal A; Al-Lohedan, Hamad A; El-Saeed, Ashraf M

    2015-01-01

    This work presents a new method to prepare poly(sodium acrylate) magnetite composite nanoparticles. Core/shell type magnetite nanocomposites were synthesized using sodium acrylate as monomer and N,N-methylenebisacrylamide (MBA) as crosslinker. Microemulsion polymerization was used for constructing core/shell structures with magnetite nanoparticles as core and poly(sodium acrylate) as shell. Fourier transform infrared spectroscopy (FTIR) was employed to characterize the nanocomposite chemical structure. Transmittance electron microscopy (TEM) was used to examine the morphology of the modified poly(sodium acrylate) magnetite composite nanoparticles. These particle will be evaluated for effective anticorrosion behavior as a hydrophobic surface on stainless steel. The composite nanoparticles has been designed by dispersing nanocomposites which act as a corrosion inhibitor. The inhibition effect of AA-Na/magnetite composites on steel corrosion in 1 M HCl solution was investigated using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Polarization measurements indicated that the studied inhibitor acts as mixed type corrosion inhibitor. EIS spectra exhibit one capacitive loop. The different techniques confirmed that the inhibition efficiency reaches 99% at 50 ppm concentration. This study has led to a better understanding of active anticorrosive magnetite nanoparticles with embedded nanocomposites and the factors influencing their anticorrosion performance. PMID:25594340

  18. Effect of Silver Nanoparticles on the Thermal Properties of Sodium Acetate Trihydrate

    NASA Astrophysics Data System (ADS)

    Garay-Ramírez, B.; Cruz-Orea, A.; San Martín-Martínez, E.

    2015-06-01

    Sodium acetate trihydrate (SAT) is used as a phase change material (PCM) because of its high latent heat of fusion. Mixtures were prepared with SAT, a blend of the polymer sodium carboxymethil cellulose (CMC) and silica gel, silver nanoparticles (AgNPs), and anhydrous sodium sulfate to form a composite-PCM (c-PCM) based on SAT; the relative proportions of CMC/silica gel in the blend and AgNP content were varied according to a central composite experimental design. The thermal properties were determined for raw SAT, CMC, , and c-PCM samples. The thermal effusivity of samples was evaluated by the inverse photopyroelectric technique. The thermal diffusivity was obtained for samples by the open photoacoustic cell technique. The thermal conductivity was calculated from the obtained and values. To assess the thermal performance of the c-PCM compared to raw SAT, samples were studied through differential scanning calorimetry which served to determine the latent heat recovery ( LHR). Properties , and LHR were analyzed by response surface methodology and compared. The SAT-based c-PCM was found to be more thermally conductive than raw SAT. The best LHR with good thermal diffusivity and thermal conductivity was identified in the region of the central composite experimental design with medium-low AgNPs and higher proportions of CMC in the polymer blend.

  19. Monodisperse sodium oleate coated magnetite high susceptibility nanoparticles for hyperthermia applications

    NASA Astrophysics Data System (ADS)

    Araújo-Neto, R. P.; Silva-Freitas, E. L.; Carvalho, J. F.; Pontes, T. R. F.; Silva, K. L.; Damasceno, I. H. M.; Egito, E. S. T.; Dantas, Ana L.; Morales, Marco A.; Carriço, Artur S.

    2014-09-01

    We report a simple and low cost methodology to synthesize sodium oleate coated magnetite nanoparticles for hyperthermia applications. The system consists of oleate coated magnetite nanoparticles with large susceptibility (1065 emu/gT), induced by the dipolar inter-particle interaction, with a magnetic core diameter in the 6 nm-12 nm size range. In aqueous medium, the nanoparticles agglomerate to form a monodisperse system, exhibiting a mean hydrodynamic diameter of 60.6 nm±4.1 nm, with a low average polydispersity index of 0.128±0.003, as required for intravenous applications. The system exhibits promising efficiency for magnetic hyperthermia, with a specific absorption rate of 14 W/g at a low field amplitude of 15.9 kA/m and frequency of 62 kHz. In a 50 mg/mL density in 1 mL, the temperature rises to 42.5 °C in 1.9 min.

  20. Mobilization of selenite by Ralstonia metallidurans CH34.

    PubMed

    Roux, M; Sarret, G; Pignot-Paintrand, I; Fontecave, M; Coves, J

    2001-02-01

    Ralstonia metallidurans CH34 (formerly Alcaligenes eutrophus CH34) is a soil bacterium characteristic of metal-contaminated biotopes, as it is able to grow in the presence of a variety of heavy metals. R. metallidurans CH34 is reported now to resist up to 6 mM selenite and to reduce selenite to elemental red selenium as shown by extended X-ray absorption fine-structure analysis. Growth kinetics analysis suggests an adaptation of the cells to the selenite stress during the lag-phase period. Depending on the culture conditions, the medium can be completely depleted of selenite. Selenium accumulates essentially in the cytoplasm as judged from electron microscopy and energy-dispersive X-ray analysis. Elemental selenium, highly insoluble, represents a nontoxic storage form for the bacterium. The ability of R. metallidurans CH34 to reduce large amounts of selenite may be of interest for bioremediation processes targeting selenite-polluted sites. PMID:11157242

  1. Regulatory effect of chrysin on expression of lenticular calcium transporters, calpains, and apoptotic-cascade components in selenite-induced cataract

    PubMed Central

    Sundararajan, Mahalingam; Thomas, Philip A.; Teresa, P. Archana; Anbukkarasi, Muniyandi

    2016-01-01

    Purpose Selenite-induced cataract is associated with oxidative stress, loss of calcium homeostasis, activation of calpain enzymes, and apoptotic cell death in the lens. An evaluation of naturally occurring antioxidants that also restrict calcium influx into the lens and calpain activation and thus prevent lenticular cell death may lead to the development of safe and effective anticataractogenic drugs. This study focuses on a naturally occurring flavone, chrysin, and its efficacy in preventing cataractogenic changes in in vitro cultured Wistar rat lenses. Methods Lenses from Wistar rats incubated for 24 h at 37 °C in Dulbecco’s modified Eagle’s medium (DMEM) were categorized into four main groups: Group I (control, incubated in DMEM alone); Group II (selenite-challenged and untreated, incubated in DMEM that contained 100 µM/ml of sodium selenite only); Group III (selenite-challenged and chrysin-treated, incubated in DMEM that contained sodium selenite [100 µM/ml of DMEM] and chrysin [200 µM/ml of DMEM]); and Group IV (chrysin-treated, incubated in DMEM that contained chrysin [200 µM/ml of DMEM] only). The Group III (selenite-challenged and chrysin-treated) lenses were further categorized into five sub-groups: Group IIIa (incubated for 24 h in DMEM that contained sodium selenite and chrysin added simultaneously), Group IIIb (first incubated for 2 h in DMEM that contained chrysin only and then for up to 24 h in fresh DMEM that contained sodium selenite only), Group IIIc (first incubated for 30 min in DMEM that contained sodium selenite only and subsequently for up to 24 h in DMEM that contained chrysin only), and Groups IIId and IIIe (first incubated for 1 h and 2 h, respectively, in DMEM that contained sodium selenite only and subsequently for up to 24 h in DMEM that contained chrysin only). Results Gross morphological assessment revealed dense opacification (Grade +++) in the selenite-challenged, untreated lenses (Group II); however, seven of the eight

  2. Effects of various polyoxyethylene sorbitan monooils (Tweens) and sodium dodecyl sulfate on reflux synthesis of copper nanoparticles

    SciTech Connect

    Zhang Xifeng; Yin Hengbo . E-mail: yin@ujs.edu.cn; Cheng Xiaonong; Hu Huifeng; Yu Qi; Wang Aili

    2006-11-09

    Size-controlled synthesis of phase pure Cu nanoparticles was carried out by using copper sulfate pentahydrate as a precursor, ascorbic acid as a reductant, Tweens and sodium dodecyl sulfate (SDS) as modifiers in an aqueous solution at 80 deg. C. The as-prepared Cu nanoparticles were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and Fourier transform infrared (FT-IR). The stabilizing effects of SDS and Tweens on the Cu nanoparticles should be through the coordination between Cu nanoparticles and the respective sulfate group and oxygen-containing bond. The synergic effect of the composite SDS and Tweens on Cu nanoparticles was different from those arising from the individuals.

  3. Alterations in lenticular proteins during ageing and selenite-induced cataractogenesis in Wistar rats

    PubMed Central

    Sakthivel, Muniyan; Elanchezhian, Rajan; Thomas, Philip A.

    2010-01-01

    Purpose To determine putative alterations in the major lenticular proteins in Wistar rats of different ages and to compare these alterations with those occurring in rats with selenite-induced cataract. Methods Lenticular transparency was determined by morphological examination using slit-lamp biomicroscopy. Alterations in lenticular protein were determined by sodium dodecyl sulfate-PAGE (SDS–PAGE) and confirmed immunologically by western blot. Results Morphological examination did not reveal observable opacities in the lenses of the rats of different age groups; however, dense nuclear opacities were noted in lenses of rats in the selenite-cataract group. Western blot assays revealed age-related changes in soluble and urea-soluble lenticular proteins. Decreased αA- and βB1-crystallins in the soluble fraction and aggregation of αA-crystallin, in addition to the degraded fragment of βB1-crystallin, in the urea-soluble fraction appeared to occur in relation to increasing age of the rats from which the lenses were taken; similarly, cytoskeletal proteins appeared to decline with increasing age. The lenses from rats in the selenite-cataract group exhibited similar changes, except that there was also high molecular weight aggregation of αA-crystallin. Conclusions The results of this study suggest that there is loss, as well as aggregation, of αA-crystallin in the aging rat lens, although there is no accompanying loss of lenticular transparency. PMID:20300567

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

    PubMed

    Fanta, George F; Kenar, James A; Felker, Frederick C; Byars, Jeffrey A

    2013-01-30

    Starch-stabilized silver nanoparticles (AgNP) were prepared from amylose-sodium palmitate helical inclusion complexes by first converting sodium palmitate within the amylose helix to silver palmitate by an ion-exchange reaction with silver nitrate, and then reducing the complexed silver palmitate salt with NaBH(4). This process yielded stable aqueous solutions that could be dried and then re-dispersed in water for end-use applications. Reaction products were characterized by inductively coupled plasma-atomic emission spectroscopy (ICP-AES), UV-VIS spectroscopy, X-ray diffraction, TEM, SEM and light microscopy. Addition of acid to reduce the pH of aqueous starch-AgNP solutions produced an increase in viscosity, and nearly quantitative precipitation of starch-AgNP was observed at low pH. Smaller AgNP and higher conversions of silver nitrate to water-soluble starch-AgNP were obtained in this process, as compared with a process carried out under similar conditions using a commercial soluble starch as a stabilizer. PMID:23218293

  5. Bismuth Nanoparticles Embedded in Carbon Spheres as Anode Materials for Sodium/Lithium-Ion Batteries.

    PubMed

    Yang, Fuhua; Yu, Fan; Zhang, Zhian; Zhang, Kai; Lai, Yanqing; Li, Jie

    2016-02-12

    Sodium-ion batteries (SIBs) are regarded as an attractive alternative to lithium-ion batteries (LIBs) for large-scale commercial applications, because of the abundant terrestrial reserves of sodium. Exporting suitable anode materials is the key to the development of SIBs and LIBs. In this contribution, we report on the fabrication of Bi@C microspheres using aerosol spray pyrolysis technique. When used as SIBs anode materials, the Bi@C microsphere delivered a high capacity of 123.5 mAh g(-1) after 100 cycles at 100 mA g(-1) . The rate performance is also impressive (specific capacities of 299, 252, 192, 141, and 90 mAh g(-1) are obtained under current densities of 0.1, 0.2, 0.5, 1, and 2 A g(-1) , respectively). Furthermore, the Bi@C microsphere also proved to be suitable LIB anode materials. The excellent electrochemical performance for both SIBs and LIBs can attributed to the Bi@C microsphere structure with Bi nanoparticles uniformly dispersed in carbon spheres. PMID:26757402

  6. Antimony nanoparticles anchored in three-dimensional carbon network as promising sodium-ion battery anode

    NASA Astrophysics Data System (ADS)

    Luo, Wen; Zhang, Pengfei; Wang, Xuanpeng; Li, Qidong; Dong, Yifan; Hua, Jingchen; Zhou, Liang; Mai, Liqiang

    2016-02-01

    A novel composite with antimony (Sb) nanoparticles anchored in three-dimensional carbon network (denoted as SbNPs@3D-C) is successfully synthesized via a NaCl template-assisted self-assembly strategy, followed by freeze-drying and one-step in-situ carbonization. The three-dimensional interconnected macroporous carbon framework can not only stabilize the architecture and buffer the volume expansion for Sb nanoparticles, but also provide high electrical conductivity for the whole electrode. Consequently, as a sodium-ion battery anode, the SbNPs@3D-C delivers a high reversible capacity (456 mAh g-1 at 100 mA g-1), stable cycling performance (94.3% capacity retention after 500 cycles at 100 mA g-1) as well as superior rate capability (270 mAh g-1 at 2000 mA g-1). When compared with commercial Sb particles, the SbNPs@3D-C exhibits dramatically enhanced electrochemical performance. Free from expensive template sources and complex manipulation, this work might shed some light on the synthesis of low-cost and high-performance materials for the next "beyond lithium" battery generation.

  7. Electrochemical investigation of methyl parathion at gold-sodium dodecylbenzene sulfonate nanoparticles modified glassy carbon electrode.

    PubMed

    Li, Chunya; Wang, Zhengguo; Zhan, Guoqin

    2011-01-01

    A gold/sodium dodecylbenzene sulfonate nanoparticles modified glassy carbon electrode (nano-Au/SDBS/GCE) was electrochemically fabricated with a constant potential at -0.4V. The obtained nano-Au/SDBS/GCE was characterized with scanning electronic microscopy, X-ray photoelectron spectroscopy and electrochemical techniques. Electrochemical behaviors of methyl parathion at the nano-Au/SDBS/GCE were thoroughly investigated. Compared to the unmodified electrode, the peak current obviously increased and the oxidation peak potential negatively shifted. These changes indicated that the composite nanoparticles possess good electrocatalytic performance on the electrochemical reaction of methyl parathion. Experimental parameters such as deposition time, pH value and accumulation conditions were optimized. Under optimum conditions, the peak current corresponding to the oxidation of the hydroxylamine group was found in a good linear relationship with the methyl parathion concentration. In addition, a calibration curve with excellent linearity was obtained in the concentration range from 5.0×10(-7)molL(-1) to 1.0×10(-4)molL(-1) with an estimated detection limit of 8.6×10(-8)molL(-1) (S/N=3). The successful determination of methyl parathion in real samples demonstrated the usefulness and potential applications of this method. PMID:20832258

  8. CO2 foam properties and the stabilizing mechanism of sodium bis(2-ethylhexyl)sulfosuccinate and hydrophobic nanoparticle mixtures.

    PubMed

    Zhang, Chao; Li, Zhaomin; Sun, Qian; Wang, Peng; Wang, Shuhua; Liu, Wei

    2016-01-21

    In this work, we have prepared CO2-in-water foam by mixing partially hydrophobic SiO2 nanoparticles and sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and studied its properties. The observation of the appearance of the foam revealed that, with the continuous addition of AOT, the phase behavior of the SiO2 nanoparticle and the AOT mixed system transformed from that of a two-phase system of aggregated nanoparticles into that of a uniform dispersed phase. Both foaming ability and foam stability were optimized when the nanoparticles and the AOT were mixed in a proportion of 1 : 5. On the basis of our findings from measurements of the dispersion properties, including measurements of the adsorption isotherm of the surfactant on the nanoparticles, zeta potentials, interfacial tension and the three-phase contact angle, we concluded that the synergistic interactions between the SiO2 nanoparticles and the AOT led to the adsorption of nanoparticles around the bubble surface and the formation of a spatial network structure of nanoparticles in the film, thereby enhancing the mechanical strength of the bubble and improving the resistance to outside disturbances, deformation and drainage. Laser scanning confocal microscopy (LCSM) analysis of the same foams further confirmed the existence of a "viscoelastic shell" wrapped around and protecting the bubble. PMID:26563818

  9. Controlled formation of ag nanoparticles by means of long-chain sodium polyacrylates in dilute solution.

    PubMed

    Huber, Klaus; Witte, Thomas; Hollmann, Jutta; Keuker-Baumann, Susanne

    2007-02-01

    A new tool is presented to control formation of Ag nanoparticles. Small amounts of silver ions were added to dilute solutions of long-chain sodium polyacrylates (NaPA). Four NaPA samples covering a molar mass regime of 97 kD < or = Mw < or = 650 kD have been used. With amounts of added Ag(+) as low as 1-2% of the COO(-) groups of the polyanionic chains, significant changes could already be induced in the NaPA coils with 650 kD. If the NaPA concentration was kept below 0.1 g/L, the coils with 650 kD exhibited a significant coil shrinking in stable solutions. At larger NaPA concentrations, addition of Ag+ initiates an aggregation of the polyacrylate coils toward compact structures. Coil shrinking and aggregation was revealed by means of time-resolved static light scattering. If exposed to UV-radiation, small Ag particles formed within the shrunken anionic polyacrylate coils. The Ag nanoparticles were identified by means of an enhanced light scattering and a characteristic plasmon absorption band around 410 nm. No such Ag particle formation could be observed even at 5 times larger concentrations of Ag(+) and NaPA if the two smallest polyacrylate samples have been used under otherwise equal conditions. This molar mass sensitive response of NaPA to Ag(+)-addition suggests an interesting phenomenon: if the coil size of the NaPa chains, which act as Ag(+) collectors, is large enough, local Ag(+) concentration in these coil-shaped Ag(+) containers exceeds a critical value, and irradiation with UV generates Ag nanoparticles. PMID:17263389

  10. Investigation on the adsorption characteristics of sodium benzoate and taurine on gold nanoparticle film by ATR-FTIR spectroscopy

    NASA Astrophysics Data System (ADS)

    Kumar, Naveen; Thomas, S.; Tokas, R. B.; Kshirsagar, R. J.

    2014-01-01

    Fourier transform infrared (FTIR) spectroscopic studies of sodium benzoate and taurine adsorbed on gold nanoparticle (AuNp) film on silanised glass slides have been studied by attenuated total reflection technique (ATR). The surface morphology of the AuNp films has been measured by Atomic Force Microscopy. The ATR spectra of sodium benzoate and taurine deposited on AuNp film are compared with ATR spectra of their powdered bulk samples. A new red-shifted band appeared along with the symmetric and asymmetric stretches of carboxylate group of sodium benzoate leading to a broadening of the above peaks. Similar behavior is also seen in the case of symmetric and asymmetric stretches of sulphonate group of taurine. The results indicate presence of both chemisorbed and physisorbed layers of both sodium benzoate and taurine on the AuNp film with bottom layer chemically bound to AuNp through carboxylate and sulphonate groups respectively.

  11. Enhancement of phototoxicity against human pancreatic cancer cells with photosensitizer-encapsulated amphiphilic sodium alginate derivative nanoparticles.

    PubMed

    Yu, Zhong; Li, Huajie; Zhang, Li-Ming; Zhu, Zhaohua; Yang, Liqun

    2014-10-01

    Photosensitizer-encapsulated amphiphilic sodium alginate derivative (Photosan-CSAD) nanoparticles were prepared because of their ability to enhance phototoxicity in the photodynamic therapy of pancreatic cancer. These nanoparticles are spherical, 150-250 nm in size as determined by transmission electron microscopy, and have negative zeta potentials. Upon incubation with human pancreatic cancer cells, the Photosan-CSAD nanoparticles showed high fluorescence activity and reactive oxygen species generation, resulting in strong phototoxicity. However, no dark toxicity was observed. Apoptosis played a leading role in the cell death process induced by the Photosan phototoxicity. These results demonstrate that the Photosan-CSAD nanoparticles are a candidate for the photodynamic therapy of pancreatic cancer. PMID:25089506

  12. Ascorbic Acid-Assisted Synthesis of Mesoporous Sodium Vanadium Phosphate Nanoparticles with Highly sp(2) -Coordinated Carbon Coatings as Efficient Cathode Materials for Rechargeable Sodium-Ion Batteries.

    PubMed

    Hung, Tai-Feng; Cheng, Wei-Jen; Chang, Wen-Sheng; Yang, Chang-Chung; Shen, Chin-Chang; Kuo, Yu-Lin

    2016-07-18

    Herein, mesoporous sodium vanadium phosphate nanoparticles with highly sp(2) -coordinated carbon coatings (meso-Na3 V2 (PO4 )3 /C) were successfully synthesized as efficient cathode material for rechargeable sodium-ion batteries by using ascorbic acid as both the reductant and carbon source, followed by calcination at 750 °C in an argon atmosphere. Their crystalline structure, morphology, surface area, chemical composition, carbon nature and amount were systematically explored. Following electrochemical measurements, the resultant meso-Na3 V2 (PO4 )3 /C not only delivered good reversible capacity (98 mAh g(-1) at 0.1 A g(-1) ) and superior rate capability (63 mAh g(-1) at 1 A g(-1) ) but also exhibited comparable cycling performance (capacity retention: ≈74 % at 450 cycles at 0.4 A g(-1) ). Moreover, the symmetrical sodium-ion full cell with excellent reversibility and cycling stability was also achieved (capacity retention: 92.2 % at 0.1 A g(-1) with 99.5 % coulombic efficiency after 100 cycles). These attributes are ascribed to the distinctive mesostructure for facile sodium-ion insertion/extraction and their continuous sp(2) -coordinated carbon coatings, which facilitate electronic conduction. PMID:27346677

  13. Fabrication and study of properties of magnetite nanoparticles in hybrid micelles of polystyrene- block-polyethylene oxide and sodium dodecyl sulfate

    NASA Astrophysics Data System (ADS)

    Loginova, T. P.; Timofeeva, G. I.; Lependina, O. L.; Shandintsev, V. A.; Matyushin, A. A.; Khotina, I. A.; Shtykova, E. V.

    2016-01-01

    Magnetite nanoparticles have been formed for the first time in hybrid micelles of polystyrene- block-polyethylene oxide and sodium dodecyl sulfate in water by ultrasonic treatment at room temperature. An analysis by small-angle X-ray scattering and transmission electron microscopy (TEM) showed that magnetite nanoparticles in hybrid micelles of block copolymer and sodium dodecyl sulfate are polydesperse (have sizes from 0.5 to 20 nm). The specific magnetization of solid samples has been measured.

  14. Preparation of solid lipid nanoparticles as drug carriers for levothyroxine sodium with in vitro drug delivery kinetic characterization.

    PubMed

    Rostami, E; Kashanian, S; Azandaryani, A H

    2014-05-01

    The aim of this work was to produce and characterize solid lipid nanoparticles (SLN) containing levothyroxine sodium for oral administration, and to evaluate the kinetic release of these colloidal carriers. SLNs were prepared by microemulsion method. The particle size and zeta potential of levothyroxine sodium-loaded SLNs were determined to be around 153 nm,-43 mV (negatively charged), respectively by photon correlation spectroscopy. The levothyroxine entrapment efficiency was over 98%. Shape and surface morphology were determined by TEM and SEM. They revealed fairly spherical shape of nanoparticles.SLN formulation was stable over a period of 6 months. There were no significant changes in particle size, zeta potential and polydispersity index and entrapment efficiency, indicating that the developed SLNs were fairly stable. PMID:24515386

  15. Selenite biotransformation during brewing. Evaluation by HPLC-ICP-MS.

    PubMed

    Sánchez-Martínez, Maria; da Silva, Erik Galvão P; Pérez-Corona, Teresa; Cámara, Carmen; Ferreira, Sergio L C; Madrid, Yolanda

    2012-01-15

    Yeast (Saccharomyces cerevisiae) and lactic bacteria have shown their ability to accumulate and transform inorganic selenium into organo Se compounds. The objective of this work was to evaluate selenium biotransformation during brewing by using S. cerevisiae and Saccharomyces uvarum for Ale and Lager fermentation, respectively. Se-enriched beer was produced by the addition of sodium selenite (0, 0.2, 1.0, 2.0, 10.0, 20.0 μg Se mL(-1), respectively) to the fermentation media composed of yeast, malt extract and water. The alcoholic fermentation process was not affected by the presence of selenium regardless of the type of Saccharomyces being used. The percentage of selenium incorporated into beer, added between 1.0 and 10 μg mL(-1) was 55-60% of the selenium initially present. Se-compounds in post-fermentation (beer and yeast) products were investigated by using an analytical methodology based on HPLC-ICP-MS. For this purpose, several sample treatments, including ultrasonic-assisted enzymatic hydrolysis, in conjunction with different separation mechanisms like dialysis and anion exchange HPLC chromatography were applied for unambiguously identifying Se-species that produce during brewing. Selenomethionine was the main selenium compound identified in beer and yeast, being this species in the only case of the former not associated to peptides or proteins. PMID:22265498

  16. Transcriptional regulation of crystallin, redox, and apoptotic genes by C-Phycocyanin in the selenite-induced cataractogenic rat model

    PubMed Central

    Kumari, Rasiah Pratheepa; Ramkumar, Srinivasagan; Thankappan, Bency; Natarajaseenivasan, Kalimuthusamy; Balaji, Sadhasivam

    2015-01-01

    Purpose This study was designed to examine the constrictive potential of C-Phycocyanin (C-PC) in regulating changes imposed on gene expression in the selenite-induced cataract model. Methods Wistar rat pups were divided into three groups of eight each. On P10, Group I received an intraperitoneal injection of normal saline. Groups II and III received a subcutaneous injection of sodium selenite (19 μmol/kg bodyweight); Group III also received an intraperitoneal injection of C-PC (200 mg/kg bodyweight) on P9–14. Total RNA was isolated on P16, and the relative abundance of mRNA of the crystallin structural genes, redox components, and apoptotic cascade were ascertained with real-time PCR with reference to the internal control β-actin. Results Real-time PCR analysis showed the crystallin genes (αA-, βB1-, γD-) and redox cycle components (Cat, SOD-1, Gpx) were downregulated, the apoptotic components were upregulated, and antiapoptotic Bcl-2 was downregulated in Group II. Treatment with 200 mg/kg bodyweight C-PC (Group III) transcriptionally regulated the instability of the expression of these genes, thus ensuring C-PC is a prospective anticataractogenic agent that probably delays the onset and progression of cataractogenesis induced by sodium selenite. Conclusions C-PC treatment possibly prevented cataractogenesis triggered by sodium selenite, by regulating the lens crystallin, redox genes, and apoptotic cascade mRNA expression and thus maintains lens transparency. C-PC may be developed as a potential antioxidant compound applied in the future to prevent and treat age-related cataract. PMID:25593511

  17. High-capacity antimony sulphide nanoparticle-decorated graphene composite as anode for sodium-ion batteries.

    PubMed

    Yu, Denis Y W; Prikhodchenko, Petr V; Mason, Chad W; Batabyal, Sudip K; Gun, Jenny; Sladkevich, Sergey; Medvedev, Alexander G; Lev, Ovadia

    2013-01-01

    Sodium-ion batteries are an alternative to lithium-ion batteries for large-scale applications. However, low capacity and poor rate capability of existing anodes are the main bottlenecks to future developments. Here we report a uniform coating of antimony sulphide (stibnite) on graphene, fabricated by a solution-based synthesis technique, as the anode material for sodium-ion batteries. It gives a high capacity of 730 mAh g(-1) at 50 mA g(-1), an excellent rate capability up to 6C and a good cycle performance. The promising performance is attributed to fast sodium ion diffusion from the small nanoparticles, and good electrical transport from the intimate contact between the active material and graphene, which also provides a template for anchoring the nanoparticles. We also demonstrate a battery with the stibnite-graphene composite that is free from sodium metal, having energy density up to 80 Wh kg(-1). The energy density could exceed that of some lithium-ion batteries with further optimization. PMID:24322450

  18. Biological Selenite Reduction and Biofilm Growth in a Microfluidic Flow Cell

    NASA Astrophysics Data System (ADS)

    Tang, Y.; Valocchi, A. J.; Werth, C. J.; Liu, W. T.; Sanford, R. A.; Singh, R.; Nobu, M.; Michelson, K.; Xue, Z.

    2014-12-01

    Selenite-contaminated groundwater can be biologically remediated in-situ by supplying an electron donor to promote the growth of selenite-reducing bacteria. We studied the fate of selenite during in-situ bioremediation using a microfluidic flow cell containing a homogeneous distribution of pores. The flow cell had two inlets: one for selenite supply, and the other for propionate (electron donor) supply. The media contained sulfate, which is common in groundwater and can affect selenite reduction. During the 5-month operation, biomass and selenite reduction products were periodically imaged using a phase contrast microscope and an environmental scanning electron microscope. Selenite reduction products were further characterized using Raman spectroscopy and energy-dispersive X-ray spectroscopy. Three types of crystals were detected in the mixing zone between selenite and propionate, and they occurred in different locations of the mixing zone. On the selenite side, selenite was biologically reduced to elemental selenium in the monoclinic form. Along the centerline, sulfate was biologically reduced to sulfide, which chemically reacted with selenite to form the second type of crystal (selenium sulfide). On the propionate side, selenium sulfide was biologically reduced to elemental selenium in the trigonal form. A mathematical model was developed to explain the segregation of the three crystals. On the selenite side, bacteria preferred selenite to sulfate since selenite can provide more energy for bacteria growth according to thermodynamics. On the propionate side, selenite was limiting; thus bacteria used selenium sulfide as their electron acceptor. Understanding this segregation can help to predict in-situ bioremediation of selenite-contaminated groundwater. Conventional prediction models consider the reaction on the selenite side as the only path of selenite removal, while a model considering the three paths of selenite removal would increase the prediction accuracy.

  19. Selenite Protection of Tellurite Toxicity Toward Escherichia coli

    PubMed Central

    Vrionis, Helen A.; Wang, Siyuan; Haslam, Bronwyn; Turner, Raymond J.

    2015-01-01

    In this work the influence of selenite on metal resistance in Escherichia coli was examined. Both synergistic and antagonistic resistance and toxicities were found upon co exposure with selenite. In wild type cells co-exposure to selenite had little effect on arsenic resistance, decreased resistance to cadmium and mercury but led to a dramatically increased resistance to tellurite of 32-fold. Due to the potential importance of thiol chemistry in metal biochemistry, deletion strains in γ-glutamylcysteine synthetase (key step in glutathione biosynthesis, encoded by gshA), thioredoxin (trxA), glutaredoxin (grxA), glutathione oxidoreductase (gor), and the periplasmic glutathione transporter (cydD) were also evaluated for resistance to various metals in the presence of selenite. The protective effect of selenite on tellurite toxicity was seen in several of the mutants and was pronounced in the gshA mutant were resistance to tellurite was increased up to 1000-fold relative to growth in the absence of selenite. Thiol oxidation studies revealed a faster rate of loss of reduced thiol content in the cell with selenite than with tellurite, indicating differential thiol reactivity. Selenite addition resulted in reactive oxygen species (ROS) production equivalent to levels associated with H2O2 addition. Tellurite addition resulted in considerably lower ROS generation while vanadate and chromate treatment did not increase ROS production above that of background. This work shows increased resistance toward most oxyanions in mutants of thiol redox suggesting that metalloid reaction with thiol components such as glutathione actually enhances toxicity of some metalloids. PMID:26732755

  20. Chondroitin sulfate-chitosan nanoparticles for ocular delivery of bromfenac sodium: Improved permeation, retention, and penetration

    PubMed Central

    Abdullah, Tara Abdulrahman; Ibrahim, Naz Jamal; Warsi, Musarrat Husain

    2016-01-01

    Introduction: Superiority of topical instillation of drug into the cul-de-sac for the treatment of various ophthalmic complications can be validated with commercial availability of a large number of conventional formulations even though this mode of instillation still elicits limitations owing to poor ocular bioavailability. To overcome the drawbacks of conventional formulations, a large number of novel carriers have been investigated. In this perspective, a new novel nanocarrier, chondroitin sulfate (ChS)-chitosan (CS)-nanoparticles (NPs) are being evaluated for improved delivery of bromfenac sodium. Materials and Methods: Formulation was developed and optimized for CS, chondroitin, and initial drug concentration. Optimized formulation was evaluated for various in vitro aspects i.e., particles’ size, size distribution, zeta potential, shape and morphology, in vitro release profile, corneal permeation, corneal retention, corneal uptake, and ocular tolerance test. Results: The mean particle size, polydispersity index, zeta potential, and entrapment efficiency of optimized formulation were found to be 245.6 ± 14.22 nm, 0.187 ± 0.016, +37.59 ± 4.05 mV, and 71.72 ± 4.43%, respectively. Transmission electron microscopic analysis revealed a spherical shape of developed formulation. Further, formulation exhibited biphasic release profile and Korsmeyer–Peppas model was found to be the best fit model. Significantly high transcorneal permeation (1.62-fold) and corneal retention (1.92-fold) of bromfenac was observed through ChS-CS-NPs when compared with marketed eyedrops (P < 0.01). Furthermore, high corneal uptake of CHS-CS-NPs was confirmed by confocal laser scanning microscopy (CLSM). Safety profile of the developed formulation was established by hen's egg test-chorioallantoic membrane test. Conclusion: Encouraging outcomes of in vitro and ex vivo studies indicated that CHS-CS-NPs could be a potential substitute for improved ocular delivery. PMID:27051629

  1. Effect of concentration of sodium silicate solution in the synthesis of silica-coated magnetite nanoparticles by ultrasonication

    NASA Astrophysics Data System (ADS)

    Fajaroh, Fauziatul; Sumari, Nazriati

    2016-02-01

    An ex-situ silica coating of magnetite nanoparticles synthesized electrochemically had been successfully carried out by ultrasonication. An aqueous solution of sodium silicate had been used as silica source.The Si-O-Si, Si-O and Fe-O-Si bonds on the surface of the silica-coated magnetite had been successfully identified using FTIR. Reduction in particle size due to the influence of ultrasound was studied using SEM. Enhancement in the specific surface area of the particles due to the silica coating and reduction in particle size was learned through BET analysis. The Characters of the resulting silica-coated magnetite were influenced by the concentration of sodium silicate solution. The greater the concentration of sodium silicate solution, the smaller the particle crystallinity and the larger the particles surface area was produced. The resulting silica-coated magnetite has a surface area of 38.171 to 67.993 m2/g, otherwise the non-coated particles only has a surface area of 27.894 m2/g. This silica-coated magnetite nanoparticles has more potent as an adsorbent than that of the bare magnetite. Besides that, the presence of silanol groups on its surface makes an opportunity for further functionalization needed for some applications.

  2. The cellular uptake and transport of zein nanoparticles: Effect of sodium caseinate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cellular evaluation of zein nanoparticles has not been studied systematically due to their poor redispersibility. Caseinate (CAS) stabilized zein nanoparticles have been recently developed with better redispersibility in salt solutions. In this study, zein-CAS nanoparticles were prepared with differ...

  3. Explorations of New SHG Materials in the Alkali-Metal-Nb(5+)-Selenite System.

    PubMed

    Cao, Xue-Li; Hu, Chun-Li; Kong, Fang; Mao, Jiang-Gao

    2015-11-16

    Standard high-temperature solid-state reactions of NaCl, Nb2O5, and SeO2 resulted in two new sodium selenites containing a second-order Jahn-Teller (SOJT) distorted Nb(5+) cation, namely, Na2Nb4O7(SeO3)4 (P1̅; 1) and NaNbO(SeO3)2 (Cmc21; 2). Compound 1 exhibits an unusual 3D [Nb4O7(SeO3)4](2-) anionic network composed of 2D [Nb4O11(SeO3)2](6-) layers which are further bridged by additional SeO3(2-) anions via corner sharing; the 2D [Nb4O11(SeO3)2](6-) layer is formed by unusual quadruple [Nb4O17](14-) niobium oxide chains of corner-sharing NbO6 octahedra being further interconnected by selenite anions via Nb-O-Se bridges. The polar compound 2 features a 1D [NbO(SeO3)2](-) anionic chain in which two neighboring Nb(5+) cations are bridged by one oxo and two selenite anions. The alignments of the polarizations from the NbO6 octahedra in 2 led to a strong SHG response of ∼7.8 × KDP (∼360 × α-SiO2), which is the largest among all phases found in metal-Nb(5+)-Se(4+)/metal-Nb(5+)-Te(4+)-O systems. Furthermore, the material is also type I phase matchable. The above experimental results are consistent with those based on DFT theoretical calculations. Thermal stabilities and optical properties for both compounds are also reported. PMID:26513233

  4. Isotonic sodium bicarbonate-triggered emodin release from borate stabilized emodin nanoparticles-loaded polymeric microgel films.

    PubMed

    Wang, Lin; Wang, Xiaohan; Li, Xiaozhou

    2014-07-20

    Hydrosoluble emodin-borate (EmB) nanoparticles (NPs) were fabricated by a simple solvent exchange method to address emodin's poor water solubility. As the result, negative charges were introduced in the surface of EmB NPs. In addition, layer-by-layer assembled multilayer films containing cation-rich polymeric microgels (named PAHD) and sodium carboxymethyl cellulose (NaCMC) were employed as drug carrier. Anionic EmB can be loaded into the PAHD/CMC multilayer films. The influences of various experimental parameters on cargo capacity of the PAHD/CMC film were studied in detail. The loaded EmB can be released in the form of emodin molecule in presence of isotonic sodium bicarbonate (ISB) solution. Gratifyingly, EmB did not almost release in presence of water, PBS buffer solution, 0.9% normal saline, and 5% glucose solution. PMID:24755249

  5. Ultrafast and stable hydrogen generation from sodium borohydride in methanol and water over Fe-B nanoparticles

    NASA Astrophysics Data System (ADS)

    Ocon, Joey D.; Tuan, Trinh Ngoc; Yi, Youngmi; de Leon, Rizalinda L.; Lee, Jae Kwang; Lee, Jaeyoung

    2013-12-01

    Use of environmentally friendly hydrogen as fuel on a massive scale requires efficient storage and generation systems. Chemical hydrides, such as sodium borohydride (NaBH4), have the capacity to meet these needs as demonstrated by its high hydrogen storage efficiency. Here, we first report the catalytic activity of Fe-B nanoparticles supported on porous Ni foam - synthesized via a simple chemical reduction technique - for hydrogen generation from the mixtures of NaBH4, H2O, and CH3OH. Activation energies of the catalyzed hydrolysis (64.26 kJ mol-1) and methanolysis (7.02 kJ mol-1) are notably lower than other metal-boron catalysts previously reported. Methanol, in combination with a cheap but highly active Fe-B nanocatalysts, provides ultrafast rates of low temperature hydrogen generation from the sodium borohydride solutions.

  6. Nanoparticles of cationic chimeric peptide and sodium polyacrylate exhibit striking antinociception activity at lower dose.

    PubMed

    Gupta, Kshitij; Singh, Vijay P; Kurupati, Raj K; Mann, Anita; Ganguli, Munia; Gupta, Yogendra K; Singh, Yogendra; Saleem, Kishwar; Pasha, Santosh; Maiti, Souvik

    2009-02-20

    The current study investigates the performance of polyelectrolyte complexes based nanoparticles in improving the antinociceptive activity of cationic chimeric peptide-YFa at lower dose. Size, Zeta potential and morphology of the nanoparticles were determined. Size of the nanoparticles decreases and zeta potential increases with concomitant increase in charge ratio (Z(+/-)). The nanoparticles at Z(+/-)12 are spherical with 70+/-7 nm diameter in AFM and displayed positive surface charge and similar sizes (83+/-8 nm) by Zetasizer. The nanoparticles of Z(+/-) 12 are used in this study. Cytotoxicity by MTT assay on three different mammalian cell lines (liver, neuronal and kidney) revealed lower toxicity of nanoparticles. Hematological parameters were also not affected by nanoparticles compared to normal counts of water treated control group. Nanoparticles containing 10 mg/kg YFa produced increased antinociception, approximately 36%, in tail-flick latency test in mice, whereas the neat peptide at the same concentration did not show any antinociception activity. This enhancement in activity is attributed to the nanoparticle associated protection of peptide from proteolytic degradation. In vitro peptide release study in plasma also supported the antinociception profile of nanoparticles. Thus, our results suggest of a potential nanoparticle delivery system for cationic peptide drug candidates for improving their stability and bioavailability. PMID:19014986

  7. Preparation of photocatalytic ZnO nanoparticles and application in photochemical degradation of betamethasone sodium phosphate using taguchi approach

    NASA Astrophysics Data System (ADS)

    Giahi, M.; Farajpour, G.; Taghavi, H.; Shokri, S.

    2014-07-01

    In this study, ZnO nanoparticles were prepared by a sol-gel method for the first time. Taguchi method was used to identify the several factors that may affect degradation percentage of betamethasone sodium phosphate in wastewater in UV/K2S2O8/nano-ZnO system. Our experimental design consisted of testing five factors, i.e., dosage of K2S2O8, concentration of betamethasone sodium phosphate, amount of ZnO, irradiation time and initial pH. With four levels of each factor tested. It was found that, optimum parameters are irradiation time, 180 min; pH 9.0; betamethasone sodium phosphate, 30 mg/L; amount of ZnO, 13 mg; K2S2O8, 1 mM. The percentage contribution of each factor was determined by the analysis of variance (ANOVA). The results showed that irradiation time; pH; amount of ZnO; drug concentration and dosage of K2S2O8 contributed by 46.73, 28.56, 11.56, 6.70, and 6.44%, respectively. Finally, the kinetics process was studied and the photodegradation rate of betamethasone sodium phosphate was found to obey pseudo-first-order kinetics equation represented by the Langmuir-Hinshelwood model.

  8. Cytotoxicity and genotoxicity of a trypanocidal drug quinapyramine sulfate loaded-sodium alginate nanoparticles in mammalian cells.

    PubMed

    Manuja, Anju; Kumar, Balvinder; Chopra, Meenu; Bajaj, Anshu; Kumar, Rajender; Dilbaghi, Neeraj; Kumar, Sandeep; Singh, Sandeep; Riyesh, T; Yadav, Suresh C

    2016-07-01

    We synthesized quinapyramine sulfate loaded-sodium alginate nanoparticles (QS-NPs) to reduce undesirable toxic effects of QS against the parasite Trypanosoma evansi, a causative agent of trypanosomosis. To determine the safety of the formulated nanoparticles, biocompatibility of QS-NPs was determined using Vero, Hela cell lines and horse erythrocytes in a dose-dependent manner. Our experiments unveiled a concentration-dependent safety/cytotoxicity (metabolic activity), genotoxicity (DNA damage, chromosomal aberrations), production of reactive oxygen species and hemolysis in QS-NPs treated cells. Annexin-V propidium iodide (PI) staining showed no massive apoptosis or necrosis. However, at very high doses (more than 300 times than the effective doses), we observed more toxicity in QS-NPs treated cells as compared to QS treated cells. QS-NPs were safe at effective trypanocidal doses and even at doses several times higher than the effective dose. PMID:27000439

  9. Attenuating the toxicity of cisplatin by using selenosulfate with reduced risk of selenium toxicity as compared with selenite

    SciTech Connect

    Zhang Jinsong Peng Dungeng; Lu Hongjuan; Liu Qingliang

    2008-02-01

    It has been reported that high doses of sodium selenite can reduce side effects of cisplatin (CDDP) without compromising its antitumor activity, thus substantially enhancing the cure rate in tumor-bearing mice. However, the toxicity of selenite at high doses should be a concern. The present study revealed that selenosulfate had much lower toxicity, but possessed equal efficacy in selenium (Se) utilization, as compared with selenite at similar doses when used for the intervention of CDDP. In addition, Se accumulation in whole blood and kidney of mice treated with selenosulfate was highly correlated with the survival rate of mice treated with CDDP (both r > 0.96 and both p < 0.05), suggesting that whole blood Se is a potential clinical biomarker to predict host tolerance to CDDP. In either Se-deficient or -sufficient mice bearing solid tumors of hepatoma 22 (H22), selenosulfate did not disturb the therapeutic effect of CDDP on tumors but effectively attenuated the toxicity of CDDP. Furthermore, in a highly malignant cancer model, with Se-sufficient mice bearing ascitic H22 cells, 8 or 10 mg/kg CDDP alone only achieved a null or 25% cure rate, whereas coadministration of selenosulfate with the above two doses of CDDP achieved cure rates of 87.5% or 75%. These results together argue for consideration of selenosulfate as an agent to enhance the therapeutic efficacy of CDDP.

  10. Gold nanoparticles assisted structural and spectroscopic modification in Er3+-doped zinc sodium tellurite glass

    NASA Astrophysics Data System (ADS)

    Awang, Asmahani; Ghoshal, S. K.; Sahar, M. R.; Arifin, R.

    2015-04-01

    Achieving enhanced spectroscopic properties of rare earth doped inorganic glasses by embedding metallic nanoparticles of controlled sizes is a challenging task. We report the gold (Au) NPs assisted modifications in structural and spectroscopic properties of melt-quench synthesized Er3+ doped zinc sodium tellurite glass. The growth of NPs is stimulated via time varying heat treatment at 300 °C. XRD patterns confirm the amorphous nature of glasses and TEM images manifest the growth of gold NPs with sizes between 6.1 and 10.7 nm. The heat treatment time dependent variations in physical properties are ascribed to the alteration in bonding of non-bridging oxygen ions. The UV-VIS-NIR spectra reveal six absorption peaks centered at 488, 523, 655, 800, 973 and 1533 nm corresponding to the transition from ground state of 4I15/2 to 4F7/2, 2H11/2, 4F9/2, 4I9/2,4I11/2, and 4I13/2 excited states of Er3+ ions, respectively. Surface plasmon resonance (SPR) bands are observed in the range of 618-632 nm. Judd-Ofelt analyses demonstrate a significant increase of spectroscopic quality factors (0.86-1.05) and branching ratio (0.62-92.38%). The up-conversion emission spectra of Er3+ exhibit three prominent peaks of reasonable green (502 nm), a moderate green (546 nm) and a strong red (629 nm). An enhancement in the red band luminescence intensity by a factor of 8.19 and 8.54 times are achieved for 2 and 4 h of heat treatments, respectively. This enhancement is attributed to the SPR effects of gold NPs producing an intense local field in the proximity of Er3+ ions and subsequent energy transfer between RE ions and NPs. The FTIR spectra display the presence of vibrational modes for ZnO4 bonds, Te-O bond in TeO3 (tp) and TeO4 (tbp) units and the hydroxyl groups. Excellent features of the results suggest that our method constitute a basis for tunable growth of gold NPs which is exceedingly useful for the optimization of optical and structural properties.

  11. Putative free radical-scavenging activity of an extract of Cineraria maritima in preventing selenite-induced cataractogenesis in Wistar rat pups

    PubMed Central

    Anitha, Thirugnanasambandhar Sivasubramanian; Muralidharan, Arumugam Ramachandran; Annadurai, Thangaraj; Jesudasan, Christdas Arul Nelson; Thomas, Philip Aloysius

    2013-01-01

    Purpose To investigate the possible free radical-scavenging activity of an extract of Cineraria maritima on selenite-induced cataractous lenses in Wistar rat pups. Methods In the present study, Wistar rat pups were divided into three experimental groups. On P10, Group I (control) rat pups received an intraperitoneal injection of 0.89% saline. Rats in groups II (selenite-challenged, untreated) and III (selenite-challenged, C. maritima treated) received a subcutaneous injection of sodium selenite (19 μmol/kg bodyweight); Group III rat pups also received an intraperitoneal injection of the extract of C. maritima (350 mg/kg bodyweight) once daily P9–14. Both eyes of each pup were examined from P16 until P30. Cytochemical localization of nitroblue tetrazolium salts and generation of superoxide, hydroxyl, and nitric oxide levels were measured. The expression of the inducible nitric oxide synthase gene was evaluated with reverse transcription-PCR. Immunoblot analysis was also performed to confirm the differential expression of the inducible nitric oxide synthase protein. Results Subcutaneous injection of sodium selenite led to severe oxidative damage in the lenticular tissues, shown by increased formation of formazan crystals, elevated generation of superoxide, hydroxyl, and nitric oxide radicals, and elevated inducible nitric oxide synthase gene and protein expression that possibly contributed to the opacification of the lens and thus cataract formation. When rat pups were treated with intraperitoneal administration of the extract of C. maritima, the generation of free radicals as well as the messenger ribonucleic acid and protein expression of inducible nitric oxide synthase were maintained at near normal levels. Conclusions The data generated by this study suggest that an ethanolic extract of C. maritima possibly prevents cataractogenesis in a rat model by minimizing free radical generation. PMID:24357923

  12. Loss of cytoskeletal proteins and lens cell opacification in the selenite cataract model.

    PubMed

    Matsushima, H; David, L L; Hiraoka, T; Clark, J I

    1997-03-01

    This study of lens protein composition found that some cytoskeletal proteins were degraded during the earliest stages of cataract formation. Cataract was induced in 13-14 day old rats by a single subcutaneous injection of sodium selenite (19 mumol kg-1). By 24 hr after the injection of selenite, the ratio of insoluble to soluble protein increased as lens opacification began. The increase in insoluble protein aggregates was correlated with an accelerated loss of proteins having molecular weights of 42, 55/57 and 235 kDa which reacted with antibodies to the cytoskeletal proteins actin, tubulin/vimentin and spectrin, respectively. We observed the loss of 49, 60 and 90 kDa proteins which were not identified. In the lenses of animals protected from protein aggregation and opacification by administration of 1.5 mmol kg-1 pantethine, the pattern of proteins in SDS-PAGE gels resembled the pattern for proteins from transparent lenses of normal untreated animals and loss of cytoskeletal proteins was prevented. PMID:9196390

  13. Bio-reduction of Selenite to Elemental Red Selenium by Tetrathiobacter kashmirensis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A bacterium that detoxifies selenite by reduction to insoluble elemental red selenium was isolated from soil. The strain showed an unusually high resistance to the toxic effects of selenite by growing in media containing 64 mM selenite. 16S rRNA gene sequence alignment identified the isolate as Tet...

  14. Chitosan coated sodium alginate-chitosan nanoparticles loaded with 5-FU for ocular delivery: in vitro characterization and in vivo study in rabbit eye.

    PubMed

    Nagarwal, Ramesh C; Kumar, Rakesh; Pandit, J K

    2012-11-20

    The objective of the study was to develop chitosan (CH) coated sodium alginate-chitosan (SA-CH) nanoparticles, i.e. CH-SA-CH NPs loaded with 5-FU for ophthalmic delivery. Drug loaded nanoparticles (DNPs) were prepared by ionic gelation technique using sodium alginate (SA) and chitosan (CH) and then suspended in chitosan solution. The mean size of nanoparticles and morphology were characterized by dynamic light scattering, scanning electron microscopy, atomic force microscopy and zeta potential. The in vitro release was studied by dialysis membrane technique. The size and drug encapsulation efficiency were dependent on molar ratio of SA and CH. The size of SA-CH nanoparticles was significantly increased with changed morphology after CH coating. SA-CH nanoparticles did not show any interaction with mucin while an enhanced viscosity was observed on coating of nanoparticles with CH. CH-SA-CH DNPs presented a sustained release of 5-FU compared to the 5-FU solution with high burst effect. In vivo study in rabbit eye showed significantly greater level of 5-FU in aqueous humor compared to 5-FU solution. The enhanced mucoadhesiveness of CH-SA-CH DNPs results in higher bioavailability as compared to the uncoated nanoparticles. Optimized formulation was found non-irritant and tolerable when tested by modified Draize test in rabbit eye. PMID:22922098

  15. Enhanced Stability and Knockdown Efficiency of Poly(ethylene glycol)- polyphosphoramidate/siRNA Micellar Nanoparticles by Co-condensation with Sodium Triphosphate

    PubMed Central

    Ren, Yong; Shyam, Rishab; Wong, Philip; Mao, Hai Quan

    2014-01-01

    Purpose Polyelectrolyte complex nanoparticles are a promis ing vehicle for siRNA delivery but suffer from low stability under physiological conditions. An effective stabilization meth od is essential for the success of polycationic nanoparticle mediated siRNA delivery. In this study, sodium triphosphate (TPP), an ionic crosslinking agent, is used to stabilize siRNA containing nanoparticles by co condensation. Methods siRNA and TPP were co encapsulated into a block copolymer, poly(ethylene glycol) b polyphosphoramidate (PEG b PPA), to form ternary nanoparticles. Physicochemical characterization was performed by dynamic light scattering and gel electrophoresis. Gene silencing efficiency in cell lines was assessed by dual luciferase assay system. Results The PEG b PPA/siRNA/TPP ternary nanoparticles exhibited high uniformity with smaller size (80 100 nm) compared with PEG b PPA/siRNA nanoparticles and showed increased stability in physiological ionic strength and serum containing medium, due to the stabilization effect from ionic crosslinks between negatively charged TPP and cationic PPA segment. Transfection and gene silencing efficiency of the TPP crosslinked nanoparticles were markedly improved over PEG b PPA/siRNA complexes in serum containing medium. No significant difference in cell viability was observed between nanoparticles prepared with and without TPP co condensation. Conclusions These results demonstrated the effectiveness of TPP co condensation in compacting polycation/siRNA nano particles, improving nanoparticle stability and enhancing the transfection and knockdown efficiency in serum containing medium. PMID:21387148

  16. Lupeol, a pentacyclic triterpenoid isolated from Vernonia cinerea attenuate selenite induced cataract formation in Sprague Dawley rat pups.

    PubMed

    Asha, Radha; Gayathri Devi, V; Abraham, Annie

    2016-02-01

    This study investigated the inhibitory effects of active component isolated from flavonoid fraction of Vernonia cinerea (FVC), lupeol on selenite induced cataract formation. Previous reports suggest that phytochemicals or natural plant products retard the process of cataractogenesis by scavenging free oxygen radicals. Hence, the present study sought to assess the potential of lupeol on in vivo selenite induced cataract models. Lupeol, a pentacyclic triterpenoid, was isolated from the ethyl acetate fraction of methanolic extract of Vernonia cinerea, follows standard chromatographic techniques. Structural elucidation of the compound was carried out using (1)H NMR, (13)C NMR, Mass spectrometry together with other complementary techniques (UV and IR). From these, the isolated compound was identified as Lupeol (3'-hydroxylup-20(29)-ene). The antioxidant activity was comparatively studied using DPPH radical scavenging and FRAP assay. Lupeol exhibited higher DPPH radical scavenging activity as well as reducing power assay. In this study, cataract was induced by a single subcutaneous injection of sodium selenite (4 μg/g body weight) on rat pups. Lupeol was administered orally from 8th day upto 21st day at a concentration 25 μg/g body weight. Cataract was visualized on 16th day with the help of an ophthalmoscope and later on with the naked eye. On the 30th day, rats were euthanized by sodium pentothal injection, lenses were excised and the biochemical parameters such as activity of superoxide dismutase (SOD), catalase (CAT), Glutathione peroxidase (GPx), Glutathione reductase (GR), Glutathione-S-transferase (GST), Ca(2+) ATPase, glutathione content (GSH), reactive oxygen species (ROS), lipid peroxidation products (malondialdehyde) were estimated and found effective in the treatment of cataract by lupeol. PMID:26697995

  17. Toward high specific capacity and high cycling stability of pure tin nanoparticles with conductive polymer binder for sodium ion batteries

    NASA Astrophysics Data System (ADS)

    Dai, Kehua; Zhao, Hui; Wang, Zhihui; Song, Xiangyun; Battaglia, Vince; Liu, Gao

    2014-10-01

    Pure Sn nanoparticles electrode with Poly(9,9-dioctylfluorene-co-fluorenone-co-methylbenzoic ester) (PFM) conductive binder was prepared and tested in sodium ion battery. It showed higher specific capacity and higher cycling stability without any carbon black compared with Sn/CMC (carboxy methylated cellulose) and Sn/PVDF (polyvinylidene fluoride) electrode. The Sn in Sn/PFM electrodes delivered 806 mAh g-1 at C/50 and 610 mAh g-1 at C/10. After 10 cycles at C/10, the capacity of Sn had no decay. SEM and TEM images showed that the Sn particles in Sn/PFM electrode were still in good conductive network despite big volume change, but parts of Sn particles in Sn/CMC or Sn/PVDF electrode are electrically isolated.

  18. A rhizobium selenitireducens protein showing selenite reductase activity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biobarriers remove, via precipitation, the metalloid selenite (SeO3–2) from groundwater; a process that involves the biological reduction of soluble SeO3–2 to insoluble elemental red selenium (Se0). The enzymes associated with this reduction process are poorly understood. In Rhizobium selenitiredu...

  19. An environmentally benign dual action antimicrobial: quaternized chitosan/sodium alga acid multilayer films and silver nanoparticles decorated on magnetic nanoparticles.

    PubMed

    Jin, Feng; Xiang, Qian; Chen, Xiaoqin; Peng, Xuefeng; Xing, Xiaodong

    2016-10-01

    There is an urgent need to develop a puissant and environmentally benign antibacterial composite that act via multiple mechanisms to make response to the potentially daunting complexity of the microbial population and microbial antibiotic resistance. In this work, a facile and green approach, layer-by-layer self-assembly technology was applied to assemble polycation quaternized chitosan (QAC) and polyanion sodium alga acid onto magnetic nanoparticles (MNPs). Then silver nanoparticles (AgNPs) with stable and narrow-sized distribution in the range of 25-35 nm were immobilized on the surface of MNPs with L-ascorbic acid as reducing agent and organic multilayers as stabilizer. Through above modification on MNPs, we expected to achieve a green dual antibacterial and recyclable composite via the combined antibacterial action of QAC and AgNPs. Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, transmission electron microscopy, zeta potentials, and dynamic light scattering were employed to confirm the success of the surface functionalization. Silver ion release process was detected by inductively coupled plasma mass spectrometry. Furthermore, the antibacterial properties of the biomaterials against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus were studied. The modified MNPs exhibited rapid, efficient, and long-lasting biocidal abilities against E. coli and S. aureus. The magnetic antibacterial composite still showed excellent antibacterial efficiency during five exposure/collection/recycle procedures. PMID:27405094

  20. Methods for Purifying and Detoxifying Sodium Dodecyl Sulfate-Stabilized Polyacrylate Nanoparticles

    PubMed Central

    Garay-Jimenez, Julio C.; Young, Ashley; Gergeres, Danielle; Greenhalgh, Kerriann; Turos, Edward

    2008-01-01

    Recent research in our laboratory has centered on studies of polyacrylate and polyacrylamide nanoparticle emulsions for use in antibiotic delivery. Our goal is to develop these nanoparticle emulsions for treatment of life-threatening bacterial infections such as those caused by methicillin-resistant Staphylococcus aureus (MRSA). For this intended application, it is necessary to ensure that the biological activity of the emulsion is due only to the drug attached to the polymeric chain, rather than to any extraneous components. To investigate this, we evaluated cytotoxicity and microbiological activity of the nanoparticle emulsions before and after purification by centrifugation, dialysis, and gel filtration. Depending on the amount of surfactant used, all or most of the microbial and cellular toxicity can be removed by a simple purification procedure. PMID:18472305

  1. Methods for purifying and detoxifying sodium dodecyl sulfate-stabilized polyacrylate nanoparticles.

    PubMed

    Garay-Jimenez, Julio C; Young, Ashley; Gergeres, Danielle; Greenhalgh, Kerriann; Turos, Edward

    2008-06-01

    Recent research in our laboratory has centered on studies of polyacrylate and polyacrylamide nanoparticle emulsions for use in antibiotic delivery. Our goal is to develop these nanoparticle emulsions for treatment of life-threatening bacterial infections such as those caused by methicillin-resistant Staphylococcus aureus. For this intended application it is necessary to ensure that the biological activity of the emulsion is due only to the drug attached to the polymeric chain and not to any extraneous components. To investigate this we evaluated cytotoxicity and microbiological activity of the nanoparticle emulsions before and after purification by centrifugation, dialysis, and gel filtration. Depending on the amount of surfactant used, all or most of the microbial and cellular toxicity can be removed by a simple purification procedure. PMID:18472305

  2. Polyvinyl pyrrolidone capped fluorescent anthracene nanoparticles for sensing fluorescein sodium in aqueous solution and analytical application for ophthalmic samples.

    PubMed

    Bhopate, Dhanaji P; Mahajan, Prasad G; Garadkar, Kalyanrao M; Kolekar, Govind B; Patil, Shivajirao R

    2015-11-01

    Based on the known complexation ability between polyvinyl pyrrolidone (PVP) and fluorescein sodium (FL Na(+)), fluorescent PVP capped anthracene nanoparticles (PVP-ANPs) were prepared using a reprecipitation method for detection of fluorescein in aqueous solution using the fluorescence resonance energy transfer (FRET) approach. A dynamic light scattering histogram of PVP-ANPs showed narrower particle size distribution and the average particle size was 15 nm. The aggregation-induced enhanced emission (AIEE) of PVP-ANPs was red shifted from its monomer by 1087.22 cm(-1). The maximum emission was seen to occur at 420 nm. The presence of FL Na(+) in the vicinity of PVP-ANPs quenched the fluorescence of PVP-ANPs because of its adsorption on the surface of PVP-ANPs in aqueous suspension. The FL Na(+) and PVP-ANPs were brought close enough, typically to 7.89 nm, which was less than the distance of 10 nm that is required between the energy donor-acceptor molecule for efficient FRET. The quenching results fit into the Stern-Volmer relationship even at temperatures greater than ambient temperatures. The thermodynamic parameters determined from FRET results helped to propose binding mechanisms involving hydrophobic and electrostatic molecular interaction. The fluorescence quenching results were used further to develop an analytical method for estimation of fluorescein sodium from ophthalmic samples available commercially in the market. PMID:25736374

  3. Entropic nature of the adsorption of sodium dodecylbenzenesulfonate on nanoparticles of aluminum and iron oxides in aqueous medium

    NASA Astrophysics Data System (ADS)

    Mansurov, R. R.; Safronov, A. P.; Lakiza, N. V.

    2016-06-01

    The adsorption of anionic surfactant sodium dodecylbenzenesulfonate (SDBS) from aqueous solution on the hydrophilic surfaces of aluminum oxide and iron oxide nanoparticles is studied via UV spectrophotometry, electrophoretic light scattering, and isothermal microcalorimetry. It is shown that the isotherms of the adsorption of SDBS on the surfaces of both oxides in the area of concentrations up to 0.6 mmol/L is linear. It is found that the positive zeta potential of the surfaces of the particles falls to zero and shifts toward the range of negative values due to adsorption. The adsorption of SDBS is characterized by positive enthalpy values over the investigated range of concentrations, while the loss of energy during adsorption indicates it is of an entropic nature. It is concluded that the probable cause of the increase in entropy is the dehydration of SDBS molecules during on surface adsorption. The obtained results are discussed in terms of the formation of hemimicelles of surfactant on the hydrophilic surfaces of metal oxide nanoparticles in an aqueous medium.

  4. Mechanism and kinetics of sodium borohydride hydrolysis over crystalline nickel and nickel boride and amorphous nickel-boron nanoparticles

    NASA Astrophysics Data System (ADS)

    Wu, Zhijie; Mao, Xikang; Zi, Qin; Zhang, Rongrong; Dou, Tao; Yip, Alex C. K.

    2014-12-01

    The initial hydrogen generation turnover rates during the hydrolysis of sodium borohydride over nickel catalysts (crystalline nickel (Ni), crystalline nickel boride (Ni3B), and amorphous nickel-boron (Ni-B) nanoparticles) were measured to investigate the reaction kinetics and mechanisms by varying the reactant concentrations and reaction temperatures. Nickel catalysts with and without boron follow different hydrolysis pathways; hydroxide ions are involved in the activation of reactant molecules over Ni3B and Ni-B catalysts. This study explicitly reports the zero-order and first-order reaction kinetics with respect to the reactant concentration over Ni, Ni3B and Ni-B catalysts. The initial hydrogen generation turnover rates and activation energies determined from the experimental data indicate that the amorphous Ni-B nanoparticles exhibit the highest turnover rate and lowest activation energy for the hydrolysis of borohydride among the investigated catalysts. This study provides a general strategy for the development of borohydride hydrolysis catalysts via the modification of a metal catalyst using boron, which causes the crystalline structure to become amorphous and leads to electron-rich, highly undercoordinated metal atoms at the surface.

  5. Insight into fractal self-assembly of poly(diallyldimethylammonium chloride)/sodium carboxymethyl cellulose polyelectrolyte complex nanoparticles.

    PubMed

    Zhao, Qiang; An, Quanfu; Qian, Jinwen; Wang, Xuesan; Zhou, Yang

    2011-12-22

    Poly(diallyldimethylammonium chloride)-sodium carboxymethyl cellulose polyelectrolyte complexes (PDDA-CMCNa PECs) solids were prepared and dispersed in NaOH aqueous solution. Self-assembly of PECs nanoparticles during the solvent evaporation was examined by field emission electron microscopy (FESEM), atomic force microscopy (AFM), and fractal dimension analysis. It was found that tree-shaped fractal patterns formed after the solvent (water) was dried at ambient temperatures, and the fractal pattern is composed of needle-shaped PEC aggregate (PECA) nanoparticles. Time-dependent FESEM observation revealed that the fractal pattern started with the formation of initial nucleon and it is growing, during which the diffusion limited aggregation (DLA) mechanism revealed and made the pattern branched. Physical insight into the DLA mechanism was discussed in detail. Effects of PEC concentrations, PEC compositions, solvent evaporation temperatures, pH of PEC dispersion, and chemical structures of PECs on the formation of self-assembled fractal pattern were studied. Generally, it was found that the morphologies, charge characters of PEC particles, and the solvent evaporation conditions play important roles during the fractal self-assembly process. PMID:22098094

  6. Real-time observation of aortic vessel dilation through delivery of sodium nitroprusside via slow release mesoporous nanoparticles.

    PubMed

    Farooq, Asima; Tosheva, Lubomira; Azzawi, May; Whitehead, Debra

    2016-09-15

    Spherical mesoporous nanoparticles (MNPs) with a diameter of ∼100nm were synthesised via a sol-gel method in the presences of organic template (with and without fluorescein dye encapsulation). The template molecules were removed by acidic extraction to form a regular pore lattice structure. The nanoparticle size and morphology were analysed using transmission electron microscopy and dynamic light scattering analysis. The MNPs were further characterised by zeta potential, nitrogen adsorption measurements and infra-red spectroscopy. The interior pores had an average diameter of ∼3nm and were loaded with an endothelial-independent vasodilator, sodium nitroprusside (SNP). The optimal drug loading and drug release was determined in high potassium physiological salt solution using dialysis and atomic absorption spectroscopy. We demonstrate that the initial instantaneous release is due to the surface desorption of the drug followed by diffusion from the pores. Furthermore, these drug loaded MNPs (with and without fluorescein dye encapsulation) were added to viable aortic vessels and release in real-time was observed, ex vivo. MNPs and loaded with and without SNP were incubated with the vessel (at 1.96×10(12)NPmL(-1)) over a 3h time period. The real-time exposure to unloaded MNPs resulted in a small attenuation in constriction that occurred after approximately 1h. In contrast, MNPs loaded with SNP led to a rapid relaxation of aortic vessels that was sustained over the 3h period (p<0.001). PMID:27288578

  7. Formulation and characterization of hydrophilic drug diclofenac sodium-loaded solid lipid nanoparticles based on phospholipid complexes technology.

    PubMed

    Liu, Dongfei; Chen, Li; Jiang, Sunmin; Zhu, Shuning; Qian, Yong; Wang, Fengzhen; Li, Rui; Xu, Qunwei

    2014-03-01

    To successfully prepare the diclofenac sodium (DS)-loaded solid lipid nanoparticles (SLNs), phospholipid complexes (PCs) technology was applied here to improve the liposolubility of DS. Solid lipid nanoparticles (SLNs) loaded with phospholipid complexes (PCs) were prepared by the modified emulsion/solvent evaporation method. DS could be solubilized effectively in the organic solvents with the existence of phospholipid and apparent partition coefficient of DS in PCs increased significantly. X-ray diffraction analysis suggested that DS in PCs was either molecularly dispersed or in an amorphous form. However, no significant difference was observed between the Fourier transform infrared spectroscopy (FT-IR) spectra of physical mixture and that of PCs. Particles with small sizes, narrow polydispersity indexes and high entrapment efficiencies could be obtained with the addition of PCs. Furthermore, according to the transmission electron microscopy, a core-shell structure was likely to be formed. The presence of PCs caused the change of zeta potential and retarded the drug release of SLNs, which indicated that phospholipid formed multilayers around the solid lipid core of SLNs. Both FT-IR and differential scanning calorimetry analysis also illustrated that some weak interactions between DS and lipid materials might take place during the preparation of SLNs. In conclusion, the model hydrophilic drug-DS can be formulated into the SLNs with the help of PCs. PMID:24236407

  8. Tunability and stability of gold nanoparticles obtained from chloroauric acid and sodium thiosulfate reaction

    NASA Astrophysics Data System (ADS)

    Zhang, Guandong; Jasinski, Jacek B.; Howell, Justin Lee; Patel, Dhruvinkumar; Stephens, Dennis P.; Gobin, Andre M.

    2012-06-01

    In the quest for producing an effective, clinically relevant therapeutic agent, scalability, repeatability, and stability are paramount. In this paper, gold nanoparticles (GNPs) with precisely controlled near-infrared (NIR) absorption are synthesized by a single-step reaction of HAuCl4 and Na2S2O3 without assistance of additional templates, capping reagents, or seeds. The anisotropy in the shape of gold nanoparticles offers high NIR absorption, making it therapeutically relevant. The synthesized products consist of GNPs with different shapes and sizes, including small spherical colloid gold particles and non-spherical gold crystals. The NIR absorption wavelengths and particle size increase with increasing molar ratio of HAuCl4/Na2S2O3. Non-spherical gold particles can be further purified and separated by centrifugation to improve the NIR-absorbing fraction of particles. In-depth studies reveal that GNPs with good structural and optical stability only form in a certain range of the HAuCl4/Na2S2O3 molar ratio, whereas higher molar ratios result in unstable GNPs, which lose their NIR absorption peak due to decomposition and reassembly via Ostwald ripening. Tuning the optical absorption of the gold nanoparticles in the NIR regime via a robust and repeatable method will improve many applications requiring large quantities of desired NIR-absorbing nanoparticles.

  9. Tungsten Trioxide (WO3) Nanoparticles as a New Anode Material for Sodium-Ion Batteries.

    PubMed

    Santhosha, A L; Das, Shyamal K; Bhattacharyya, Aninda J

    2016-04-01

    Tungsten trioxide (WO3) is investigated for the first time as an anode material for sodium-ion batteries. Pristine WO3 displays a discharge potential plateau at 1 V and exhibits a 1st discharge cycle sodium storage capacity of 640 mAh g-1. Electronic wiring of WO3 with graphene oxide (GO, 1% by weight) led to a significant increase in the storage capacity and cyclability of WO3. As a result, the discharge capacity of 1% GO-WO3 is enhanced to 927 mAh g-1 in the 1st discharge cycle. The electrochemical intercalation of Na in to WO3 and (1%) GO-WO3 as obtained from galvanostatic charge/discharge cycling is also supported by cyclic voltammetry. PMID:27451776

  10. On the mechanical properties of selenite glass nanocomposites

    NASA Astrophysics Data System (ADS)

    Bar, Arun Kr.; Kundu, Ranadip; Roy, Debasish; Bhattacharya, Sanjib

    2016-05-01

    In this paper the room temperature micro-hardness of selenite glass-nanocomposites has been measured using a Vickers and Knoop micro hardness tester where the applied load varies from 0.01N to 0.98 N. A significant indentation size effect was observed for each sample at relatively low indentation test loads. The classical Meyer's law and the proportional specimen resistance model were used to analyze the micro-hardness behavior. It was found that the selenite glass-nanocomposite becomes harder with increasing CuI composition and the work hardening coefficient and mechanical properties like Young modulus, E, were also calculated. Our results open the way for the preparation, application and investigation of significant mechanical properties of new type of glass-nanocomposites.

  11. Immobilization of selenite via two parallel pathways during in situ bioremediation.

    PubMed

    Tang, Youneng; Werth, Charles J; Sanford, Robert A; Singh, Rajveer; Michelson, Kyle; Nobu, Masaru; Liu, Wen-Tso; Valocchi, Albert J

    2015-04-01

    It is widely understood that selenite can be biologically reduced to elemental selenium. Limited studies have shown that selenite can also be immobilized through abiotic precipitation with sulfide, a product of biological sulfate reduction. We demonstrate that both pathways significantly contribute to selenite immobilization in a microfluidic flow cell having a transverse mixing zone between propionate and selenite that mimics the reaction zone along the margins of a selenite plume undergoing bioremediation in the presence of background sulfate. The experiment showed that red particles of amorphous elemental selenium precipitate on the selenite-rich side of the mixing zone, while long crystals of selenium sulfides precipitate on the propionate-rich side of the mixing zone. We developed a continuum-scale reactive transport model that includes both pathways. The simulated results are consistent with the experimental results, and indicate that spatial segregation of the two selenium precipitates is due to the segregation of the more thermodynamic favorable selenite reduction and the less thermodynamically favorable sulfate reduction. The improved understanding of selenite immobilization and the improved model can help to better design in situ bioremediation processes for groundwater contaminated by selenite or other contaminants (e.g., uranium(IV)) that can be immobilized via similar pathways. PMID:25734534

  12. Gold nanoparticle/multi-walled carbon nanotube modified glassy carbon electrode as a sensitive voltammetric sensor for the determination of diclofenac sodium.

    PubMed

    Afkhami, Abbas; Bahiraei, Atousa; Madrakian, Tayyebeh

    2016-02-01

    A simple and highly sensitive sensor for the determination of diclofenac sodium based on gold nanoparticle/multi-walled carbon nanotube modified glassy carbon electrode is reported. Scanning electron microscopy along with energy dispersive X-ray spectroscopy, electrochemical impedance spectroscopy, cyclic voltammetry and square wave voltammetry was used to characterize the nanostructure and performance of the sensor and the results were compared with those obtained at the multi-walled carbon nanotube modified glassy carbon electrode and bare glassy carbon electrode. Under the optimized experimental conditions diclofenac sodium gave linear response over the range of 0.03-200μmolL(-1). The lower detection limits were found to be 0.02μmolL(-1). The effect of common interferences on the current response of DS was investigated. The practical application of the modified electrode was demonstrated by measuring the concentration of diclofenac sodium in urine and pharmaceutical samples. This revealed that the gold nanoparticle/multiwalled carbon nanotube modified glassy carbon electrode shows excellent analytical performance for the determination of diclofenac sodium in terms of a very low detection limit, high sensitivity, very good accuracy, repeatability and reproducibility. PMID:26652361

  13. Magnetic properties of magnetite nanoparticles crystallized in sodium-aluminoborosilicate glass matrix

    NASA Astrophysics Data System (ADS)

    Georgieva, M.; Tzankov, D.; Harizanova, R.; Avdeev, G.; Rüssel, C.

    2016-03-01

    Magnetite (Fe3O4) nanoparticles were crystallized from soda alumina borosilicate glasses with the composition (24- y)Na2O· yAl2O3·14B2O3·37SiO2·25Fe2O3, where y = 8, 12, 14, 16 mol%. All samples are phase separated into magnetite core, enriched in iron oxide, and a glass shell. The magnetic core phase consists of nanocrystallites with sizes ranging between 25 and 40 nm, depending on the respective glass composition. All samples show characteristic well-defined hysteresis loops at room temperature, indicating that the magnetite particles are ferrimagnetic. No evidence for the existence of superparamagnetic particles is found by measuring the ZFC and FC thermomagnetic curves.

  14. High sulfur content polymer nanoparticles obtained from interfacial polymerization of sodium polysulfide and 1,2,3-trichloropropane in water.

    PubMed

    Lim, Jeewoo; Jung, Unho; Joe, Won Tae; Kim, Eui Tae; Pyun, Jeffrey; Char, Kookheon

    2015-06-01

    Sulfur-rich materials have recently attracted keen interest for their potentials in optical, electrochemical, and pesticidal applications as well as their utility in dynamic covalent bond chemistry. Many sulfur-rich polymers, however, are insoluble and processing methods are therefore very limited. The synthesis and characterization of water-dispersible polymer nanoparticles (NPs) with the sulfur content exceeding 75% by weight, obtained from the interfacial polymerization between 1,2,3-trichloropropane and sodium polysulfide in water is reported here. The interfacial polymerization yields well-defined sulfur-rich NPs in the presence of surfactants, which are capable of serving a dual role as a phase transfer catalyst on top of emulsifiers. Such dual role allows for the control of the product NP size by varying its concentration. The surfactants can be easily removed by centrifugation and redispersion in water is also reported here. The resulting sulfur-rich NPs are characterized through elemental analysis, dynamic light scattering, ζ-potential measurements, and scanning electron microscopy. PMID:25847485

  15. Surface modification of poly(D,L-lactic-co-glycolic acid) nanoparticles using sodium carboxymethyl cellulose as colloidal stabilize.

    PubMed

    Chittasupho, Chuda; Thongnopkoon, Thanu; Kewsuwan, Prartana

    2016-01-01

    Poly(D,L-lactic-co-glycolic acid) nanoparticles (PLGA NPs) have been widely used as drug delivery systems for both small molecules and macromolecules. However, the colloidal stability problem remains unsolved. This study aims to investigate the possibility of using sodium carboxymethyl cellulose (SCMC) as a stabilizing agent of PLGA NPs. In this study, PLGA NPs were fabricated using various concentrations of SCMC (0.01, 0.1 and 0.5% w/v) by solvent displacement method. SCMC coated NPs were characterized using DLS, FTIR, DSC, colorimetric method. Particle size, polydispersity index, zeta potential values and SCMC adsorption increased with SCMC concentration. FTIR spectra, DSC thermograms and results of colorimetry suggested the interaction of SCMC and PLGA NPs. The stability of SCMC coated PLGA NPs was observed during the storage of three weeks in water. The stability of SCMC coated NPs in serum was also evaluated. Cell viability study revealed that there was no toxicity increased when SCMC was used as a stabilizing agent up to a concentration of 0.1% w/v. SCMC coated PLGA NPs bound A549 cells in a time dependent manner and with a greater extent than uncoated PLGA NPs. In conclusion, SCMC can be used to stabilize PLGA NPs by adsorbing on the surface of NPs. PMID:26338259

  16. Multilayer sodium alginate beads with porous core containing chitosan based nanoparticles for oral delivery of anticancer drug.

    PubMed

    Li, Jing; Jiang, Changqing; Lang, Xuqian; Kong, Ming; Cheng, Xiaojie; Liu, Ya; Feng, Chao; Chen, Xiguang

    2016-04-01

    To develop efficient and safe anticancer drug doxorubicin hydrochloride (DOX) delivery system for oral chemotherapy, chitosan based nanoparticles (CS/CMCS-NPs) composed of chitosan (CS) and o-carboxymeymethy chitosan (CMCS) were immobilized in multilayer sodium alginate beads (NPs-M-Beads). Two kinds of NPs-M-Beads, with or without porous core, were respectively prepared by internal or external ionic gelation method. In the small intestine, the intact CS/CMCS-NPs were able to escape from porous-beads and sustained release the loading DOX. In vivo results showed that the DOX could be efficiently absorbed by small intestine of SD rat and the higher concentration of the DOX in major organs of rats were found after oral administration of Porous-Beads, which were about 2-4 folds higher than that of non-porous-beads. These results suggested that the NPs-M-Beads with porous core to be exciting and promising for oral delivery of DOX. PMID:26724684

  17. Drying and nondrying layer-by-layer assembly for the fabrication of sodium silicate/TiO2 nanoparticle composite films.

    PubMed

    Zhang, Lianbin; Liu, He; Zhao, Engui; Qiu, Lingying; Sun, Junqi; Shen, Jiacong

    2012-01-24

    Influences of drying and nondrying steps on structures of layer-by-layer (LbL) assembled sodium silicate/TiO(2) nanoparticles films (donated as silicate/TiO(2) films) have been systematically investigated. The nondrying LbL assembly produces highly porous silicate/TiO(2) films with large thickness. In contrast, the silicate/TiO(2) films fabricated with a drying step after each layer deposition are flat and thin without porous structures. In situ atomic force microscopy (AFM) measurements confirm that the sodium silicate and TiO(2) nanoparticles are deposited in their aggregated forms. A N(2) drying step can disintegrate the aggregated silicate and TiO(2) nanoparticles to produce thin silicate/TiO(2) films with compact structures. Without the drying steps, the aggregated silicate and TiO(2) nanoparticles are well retained, and their LbL assembly produces highly porous silicate/TiO(2) films of large thickness. The highly porous silicate/TiO(2) films are demonstrated to be useful as reusable film adsorbents for dye removal from wastewater because they can adsorb a large amount of cationic organic dyes and decompose them under UV irradiation. The present study is meaningful for exploring drying/nondrying steps for tailoring structure and functions of LbL assembled films. PMID:22185571

  18. CROSS-DISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY: Synthesis and photoluminescence properties of Nd2O3 nanoparticles modified by sodium bis(2-ethylhexyl) sulfosuccinate

    NASA Astrophysics Data System (ADS)

    Ren, Jian-Hua; Zhao, Tong-Gang; Liu, Jian-Hua; Kong, Juan; He, Jia-Xin; Guo, Lin

    2008-12-01

    This paper reports that Nd2O3 nanoparticles modified by AOT(sodium bis(2-ethylhexyl) sulfosuccinate) were prepared using microemulsion method in the system of water and propanol/AOT/toluene. Transmission electron microscopy shows that the Nd2O3 nanoparticles take the shape of sphere with 18 nm and 31 nm with different preparation. The organic sol of Nd2O3 nanoparticles is very stable at room temperature. X-ray diffraction results show that the product has hexagonal phase structure. Two ultraviolet emission band at 344 nm and 361 nm corresponding to the transition of 4D3/2 → 4 I9/2 and 2P3 /2 →4 I11/2 or 4D3/2 → 4 I13/2 were observed.

  19. Assembly of SnSe Nanoparticles Confined in Graphene for Enhanced Sodium-Ion Storage Performance.

    PubMed

    Yang, Xu; Zhang, Rongyu; Chen, Nan; Meng, Xing; Yang, Peilei; Wang, Chunzhong; Zhang, Yaoqing; Wei, Yingjin; Chen, Gang; Du, Fei

    2016-01-22

    Sodium-ion batteries (SIBs) have attracted much interest as a low-cost and environmentally benign energy storage system, but more attention is justifiably required to address the major technical issues relating to the anode materials to deliver high reversible capacity, superior rate capability, and stable cyclability. A SnSe/reduced graphene oxide (RGO) nanocomposite has been prepared by a facile ball-milling method, and its structural, morphological, and electrochemical properties have been characterized and compared with those of the bare SnSe material. Although the redox behavior of SnSe remains nearly unchanged upon the incorporation of RGO, its electrochemical performance is significantly enhanced, as reflected by a high specific capacity of 590 mA h g(-1) at 0.050 A g(-1) , a rate capability of 260 mA h g(-1) at 10 A g(-1) , and long-term stability over 120 cycles. This improvement may be attributed to the high electronic conductivity of RGO, which also serves as a matrix to buffer changes in volume and maintain the mechanical integrity of the electrode during (de)sodiation processes. In view of its excellent Na(+) storage performance, this SnSe/RGO nanocomposite has potential as an anode material for SIBs. PMID:26680235

  20. Nickel hexacyanoferrate nanoparticle electrodes for aqueous sodium and potassium ion batteries.

    PubMed

    Wessells, Colin D; Peddada, Sandeep V; Huggins, Robert A; Cui, Yi

    2011-12-14

    The electrical power grid faces a growing need for large-scale energy storage over a wide range of time scales due to costly short-term transients, frequency regulation, and load balancing. The durability, high power, energy efficiency, and low cost needed for grid-scale storage pose substantial challenges for conventional battery technology. (1, 2) Here, we demonstrate insertion/extraction of sodium and potassium ions in a low-strain nickel hexacyanoferrate electrode material for at least five thousand deep cycles at high current densities in inexpensive aqueous electrolytes. Its open-framework structure allows retention of 66% of the initial capacity even at a very high (41.7C) rate. At low current densities, its round trip energy efficiency reaches 99%. This low-cost material is readily synthesized in bulk quantities. The long cycle life, high power, good energy efficiency, safety, and inexpensive production method make nickel hexacyanoferrate an attractive candidate for use in large-scale batteries to support the electrical grid. PMID:22043814

  1. Encapsulation of beraprost sodium in nanoparticles: analysis of sustained release properties, targeting abilities and pharmacological activities in animal models of pulmonary arterial hypertension.

    PubMed

    Ishihara, Tomoaki; Hayashi, Erika; Yamamoto, Shuhei; Kobayashi, Chisa; Tamura, Yuichi; Sawazaki, Ryoichi; Tamura, Fumiya; Tahara, Kayoko; Kasahara, Tadashi; Ishihara, Tsutomu; Takenaga, Mitsuko; Fukuda, Keiichi; Mizushima, Tohru

    2015-01-10

    Prostaglandin I2 (PGI2) and its analogues (such as beraprost sodium, BPS) are beneficial for the treatment of pulmonary arterial hypertension (PAH). The encapsulation of BPS in nanoparticles to provide sustained release and targeting abilities would improve both the therapeutic effect of BPS on PAH and the quality of life of patients treated with this drug. BPS was encapsulated into nanoparticles prepared from a poly(lactic acid) homopolymer and monomethoxy poly(ethyleneglycol)-poly(lactide) block copolymer. The accumulation of nanoparticles in damaged pulmonary arteries was examined using fluorescence-emitting rhodamine S-encapsulated nanoparticles. The monocrotaline-induced PAH rat model and the hypoxia-induced mouse model were used to examine the pharmacological activity of BPS-encapsulated nanoparticles. A nanoparticle, named BPS-NP, was selected among various types of BPS-encapsulated nanoparticles tested; this was based on the sustained release profile in vitro and blood clearance profile in vivo. Fluorescence-emitting rhodamine S-encapsulated nanoparticles were prepared in a similar manner to that of BPS-NP, and showed accumulation and prolonged residence in monocrotaline-damaged pulmonary peripheral arteries. Intravenous administration of BPS-NP (once per week, 20μg/kg) protected against monocrotaline-induced pulmonary arterial remodeling and right ventricular hypertrophy. The extent of this protection was similar to that observed with oral administration (once per day, 100μg/kg) of BPS alone. The once per week intravenous administration of BPS-NP (20μg/kg) also exhibited an ameliorative effect on hypoxia-induced pulmonary arterial remodeling and right ventricular hypertrophy. The beneficial effects of BPS-NP on PAH animal models seem to be mediated by its sustained release and tissue targeting profiles. BPS-NP may be useful for the treatment of PAH patients due to reduced dosages and frequency of BPS administration. PMID:25449809

  2. Progress toward clonable inorganic nanoparticles

    NASA Astrophysics Data System (ADS)

    Ni, Thomas W.; Staicu, Lucian C.; Nemeth, Richard S.; Schwartz, Cindi L.; Crawford, David; Seligman, Jeffrey D.; Hunter, William J.; Pilon-Smits, Elizabeth A. H.; Ackerson, Christopher J.

    2015-10-01

    Pseudomonas moraviensis stanleyae was recently isolated from the roots of the selenium (Se) hyperaccumulator plant Stanleya pinnata. This bacterium tolerates normally lethal concentrations of SeO32- in liquid culture, where it also produces Se nanoparticles. Structure and cellular ultrastructure of the Se nanoparticles as determined by cellular electron tomography shows the nanoparticles as intracellular, of narrow dispersity, symmetrically irregular and without any observable membrane or structured protein shell. Protein mass spectrometry of a fractionated soluble cytosolic material with selenite reducing capability identified nitrite reductase and glutathione reductase homologues as NADPH dependent candidate enzymes for the reduction of selenite to zerovalent Se nanoparticles. In vitro experiments with commercially sourced glutathione reductase revealed that the enzyme can reduce SeO32- (selenite) to Se nanoparticles in an NADPH-dependent process. The disappearance of the enzyme as determined by protein assay during nanoparticle formation suggests that glutathione reductase is associated with or possibly entombed in the nanoparticles whose formation it catalyzes. Chemically dissolving the nanoparticles releases the enzyme. The size of the nanoparticles varies with SeO32- concentration, varying in size form 5 nm diameter when formed at 1.0 μM [SeO32-] to 50 nm maximum diameter when formed at 100 μM [SeO32-]. In aggregate, we suggest that glutathione reductase possesses the key attributes of a clonable nanoparticle system: ion reduction, nanoparticle retention and size control of the nanoparticle at the enzyme site.Pseudomonas moraviensis stanleyae was recently isolated from the roots of the selenium (Se) hyperaccumulator plant Stanleya pinnata. This bacterium tolerates normally lethal concentrations of SeO32- in liquid culture, where it also produces Se nanoparticles. Structure and cellular ultrastructure of the Se nanoparticles as determined by cellular

  3. Modeling selenite adsorption envelopes on oxides, clay minerals, and soils using the triple layer model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenite adsorption behavior was investigated on amorphous aluminum and iron oxides, clay minerals: kaolinite, montmorillonite, and illite, and 45 surface and subsurface soil samples from the Southwestern and Midwestern regions of the USA as a function of solution pH. Selenite adsorption decreased ...

  4. Reduction of Selenite to Elemental Red Selenium by Pseudomonas sp. strain CA5

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A Pseudomonas sp. that may be useful in bioremediation projects was isolated from soil. The strain is of potential value because it reduces selenite to elemental red selenium and is unusual in that it was resistant to high concentrations of both selenate and selenite. Cell of the strain removed 1....

  5. Selenite reduction by Shewanella oneidensis MR-1 is mediated by fumarate reductase in periplasm

    NASA Astrophysics Data System (ADS)

    Li, Dao-Bo; Cheng, Yuan-Yuan; Wu, Chao; Li, Wen-Wei; Li, Na; Yang, Zong-Chuang; Tong, Zhong-Hua; Yu, Han-Qing

    2014-01-01

    In situ reduction of selenite to elemental selenium (Se(0)), by microorganisms in sediments and soils is an important process and greatly affects the environmental distribution and the biological effects of selenium. However, the mechanism behind such a biological process remains unrevealed yet. Here we use Shewanella oneidensis MR-1, a widely-distributed dissimilatory metal-reducing bacterium with a powerful and diverse respiration capability, to evaluate the involvement of anaerobic respiration system in the microbial selenite reduction. With mutants analysis, we identify fumarate reductase FccA as the terminal reductase of selenite in periplasm. Moreover, we find that such a reduction is dependent on central respiration c-type cytochrome CymA. In contrast, nitrate reductase, nitrite reductase, and the Mtr electron transfer pathway do not work as selenite reductases. These findings reveal a previously unrecognized role of anaerobic respiration reductases of S. oneidensis MR-1 in selenite reduction and geochemical cycles of selenium in sediments and soils.

  6. Sodium-22-radiolabeled silica nanoparticles as new radiotracer for biomedical applications: in vivo positron emission tomography imaging, biodistribution, and biocompatibility

    PubMed Central

    Al Faraj, Achraf; Alotaibi, Basem; Shaik, Abjal Pasha; Shamma, Khaled Z; Al Jammaz, Ibrahim; Gerl, Jürgen

    2015-01-01

    Despite their advantageous chemical properties for nuclear imaging, radioactive sodium-22 (22Na) tracers have been excluded for biomedical applications because of their extremely long lifetime. In the current study, we proposed, for the first time, the use of 22Na radiotracers for pre-clinical applications by efficiently loading with silica nanoparticles (SiNPs) and thus offering a new life for this radiotracer. Crown-ether-conjugated SiNPs (300 nm; −0.18±0.1 mV) were successfully loaded with 22Na with a loading efficacy of 98.1%±1.4%. Noninvasive positron emission tomography imaging revealed a transient accumulation of 22Na-loaded SiNPs in the liver and to a lower extent in the spleen, kidneys, and lung. However, the signal gradually decreased in a time-dependent manner to become not detectable starting from 2 weeks postinjection. These observations were confirmed ex vivo by quantifying 22Na radioactivity using γ-counter and silicon content using inductively coupled plasma-mass spectrometry in the blood and the different organs of interest. Quantification of Si content in the urine and feces revealed that SiNPs accumulated in the organs were cleared from the body within a period of 2 weeks and completely in 1 month. Biocompatibility evaluations performed during the 1-month follow-up study to assess the possibility of synthesized nanocarriers to induce oxidative stress or DNA damage confirmed their safety for pre-clinical applications. 22Na-loaded nanocarriers can thus provide an innovative diagnostic agent allowing ultra-sensitive positron emission tomography imaging. On the other hand, with its long lifetime, onsite generators or cyclotrons will not be required as 22Na can be easily stored in the nuclear medicine department and be used on-demand. PMID:26504381

  7. Incorporation of neptunium(VI) into a uranyl selenite.

    PubMed

    Meredith, Nathan A; Polinski, Matthew J; Lin, Jian; Simonetti, Antonio; Albrecht-Schmitt, Thomas E

    2012-10-15

    The incorporation of neptunium(VI) into the layered uranyl selenite Cs[(UO(2))(HSeO(3))(SeO(3))] has yielded the highest level of neptunium uptake in a uranyl compound to date with an average of 12(±3)% substitution of Np(VI) for U(VI). Furthermore, this is the first case in nearly 2 decades of dedicated incorporation studies in which the oxidation state of neptunium has been determined spectroscopically in a doped uranyl compound and also the first time in which neptunium incorporation has resulted in a structural transformation. PMID:23030830

  8. HIV-1 Gag Blocks Selenite-Induced Stress Granule Assembly by Altering the mRNA Cap-Binding Complex

    PubMed Central

    Cinti, Alessandro; Le Sage, Valerie; Ghanem, Marwan

    2016-01-01

    ABSTRACT Stress granules (SGs) are dynamic accumulations of stalled preinitiation complexes and translational machinery that assemble under stressful conditions. Sodium selenite (Se) induces the assembly of noncanonical type II SGs that differ in morphology, composition, and mechanism of assembly from canonical SGs. Se inhibits translation initiation by altering the cap-binding activity of eukaryotic translation initiation factor 4E (eIF4E)-binding protein 1 (4EBP1). In this work, we show that human immunodeficiency virus type 1 (HIV-1) Gag is able to block the assembly of type II noncanonical SGs to facilitate continued Gag protein synthesis. We demonstrate that expression of Gag reduces the amount of hypophosphorylated 4EBP1 associated with the 5′ cap potentially through an interaction with its target, eIF4E. These results suggest that the assembly of SGs is an important host antiviral defense that HIV-1 has evolved for inhibition through several distinct mechanisms. PMID:27025252

  9. The Comparative Studies of Binding Activity of Curcumin and Didemethylated Curcumin with Selenite: Hydrogen Bonding vs Acid-Base Interactions.

    PubMed

    Liao, Jiahn-Haur; Wu, Tzu-Hua; Chen, Ming-Yi; Chen, Wei-Ting; Lu, Shou-Yun; Wang, Yi-Hsuan; Wang, Shao-Pin; Hsu, Yen-Min; Huang, Yi-Shiang; Huang, Zih-You; Lin, Yu-Ching; Chang, Ching-Ming; Huang, Fu-Yung; Wu, Shih-Hsiung

    2015-01-01

    In this report, the in vitro relative capabilities of curcumin (CCM) and didemethylated curcumin (DCCM) in preventing the selenite-induced crystallin aggregation were investigated by turbidity tests and isothermal titration calorimetry (ITC). DCCM showed better activity than CCM. The conformers of CCM/SeO3(2-) and DCCM/SeO3(2-) complexes were optimized by molecular orbital calculations. Results reveal that the selenite anion surrounded by CCM through the H-bonding between CCM and selenite, which is also observed via IR and NMR studied. For DCCM, the primary driving force is the formation of an acid-base adduct with selenite showing that the phenolic OH group of DCCM was responsible for forming major conformer of DCCM. The formation mechanisms of selenite complexes with CCM or DCCM explain why DCCM has greater activity than CCM in extenuating the toxicity of selenite as to prevent selenite-induced lens protein aggregation. PMID:26635113

  10. The Comparative Studies of Binding Activity of Curcumin and Didemethylated Curcumin with Selenite: Hydrogen Bonding vs Acid-Base Interactions

    NASA Astrophysics Data System (ADS)

    Liao, Jiahn-Haur; Wu, Tzu-Hua; Chen, Ming-Yi; Chen, Wei-Ting; Lu, Shou-Yun; Wang, Yi-Hsuan; Wang, Shao-Pin; Hsu, Yen-Min; Huang, Yi-Shiang; Huang, Zih-You; Lin, Yu-Ching; Chang, Ching-Ming; Huang, Fu-Yung; Wu, Shih-Hsiung

    2015-12-01

    In this report, the in vitro relative capabilities of curcumin (CCM) and didemethylated curcumin (DCCM) in preventing the selenite-induced crystallin aggregation were investigated by turbidity tests and isothermal titration calorimetry (ITC). DCCM showed better activity than CCM. The conformers of CCM/SeO32- and DCCM/SeO32- complexes were optimized by molecular orbital calculations. Results reveal that the selenite anion surrounded by CCM through the H-bonding between CCM and selenite, which is also observed via IR and NMR studied. For DCCM, the primary driving force is the formation of an acid-base adduct with selenite showing that the phenolic OH group of DCCM was responsible for forming major conformer of DCCM. The formation mechanisms of selenite complexes with CCM or DCCM explain why DCCM has greater activity than CCM in extenuating the toxicity of selenite as to prevent selenite-induced lens protein aggregation.

  11. The Comparative Studies of Binding Activity of Curcumin and Didemethylated Curcumin with Selenite: Hydrogen Bonding vs Acid-Base Interactions

    PubMed Central

    Liao, Jiahn-Haur; Wu, Tzu-Hua; Chen, Ming-Yi; Chen, Wei-Ting; Lu, Shou-Yun; Wang, Yi-Hsuan; Wang, Shao-Pin; Hsu, Yen-Min; Huang, Yi-Shiang; Huang, Zih-You; Lin, Yu-Ching; Chang, Ching-Ming; Huang, Fu-Yung; Wu, Shih-Hsiung

    2015-01-01

    In this report, the in vitro relative capabilities of curcumin (CCM) and didemethylated curcumin (DCCM) in preventing the selenite-induced crystallin aggregation were investigated by turbidity tests and isothermal titration calorimetry (ITC). DCCM showed better activity than CCM. The conformers of CCM/SeO32− and DCCM/SeO32− complexes were optimized by molecular orbital calculations. Results reveal that the selenite anion surrounded by CCM through the H-bonding between CCM and selenite, which is also observed via IR and NMR studied. For DCCM, the primary driving force is the formation of an acid-base adduct with selenite showing that the phenolic OH group of DCCM was responsible for forming major conformer of DCCM. The formation mechanisms of selenite complexes with CCM or DCCM explain why DCCM has greater activity than CCM in extenuating the toxicity of selenite as to prevent selenite-induced lens protein aggregation. PMID:26635113

  12. Selenite Stimulates Mitochondrial Biogenesis Signaling and Enhances Mitochondrial Functional Performance in Murine Hippocampal Neuronal Cells

    PubMed Central

    Idris, Haza; Kumari, Santosh; Li, P. Andy

    2012-01-01

    Supplementation of selenium has been shown to protect cells against free radical mediated cell damage. The objectives of this study are to examine whether supplementation of selenium stimulates mitochondrial biogenesis signaling pathways and whether selenium enhances mitochondrial functional performance. Murine hippocampal neuronal HT22 cells were treated with sodium selenite for 24 hours. Mitochondrial biogenesis markers, mitochondrial respiratory rate and activities of mitochondrial electron transport chain complexes were measured and compared to non-treated cells. The results revealed that treatment of selenium to the HT22 cells elevated the levels of nuclear mitochondrial biogenesis regulators PGC-1α and NRF1, as well as mitochondrial proteins cytochrome c and cytochrome c oxidase IV (COX IV). These effects are associated with phosphorylation of Akt and cAMP response element-binding (CREB). Supplementation of selenium significantly increased mitochondrial respiration and improved the activities of mitochondrial respiratory complexes. We conclude that selenium activates mitochondrial biogenesis signaling pathway and improves mitochondrial function. These effects may be associated with modulation of AKT-CREB pathway. PMID:23110128

  13. Selenite transport in unsaturated tuff from Yucca Mountain

    SciTech Connect

    Conca, J.L.; Triay, I.R.

    1994-04-01

    Direct measurements of unsaturated selenite retardation coefficients and unsaturated hydraulic conductivity were obtained on two tuff samples from Yucca Mountain using the UFA{trademark} technology. The retardation factor for the selenite species was only 2.5 in both Yucca Mountain vitric member at 62.6% saturation and zeolitized nonwelded tuff from G-tunnel at 52.8% saturation with respect to J-13 well water from the Nevada Test Site contaminated with selenium at 1.31 mg/l (ppm). In batch tests on the same material using 1.2 mg/l (ppm), the average K{sub d} was determined to be 13, giving retardation factors higher than the UFA column breakthrough tests by an order of magnitude. The difference could result from preferential flow paths in the UFA column as might occur in the field or differences in residence times between the two types of test. The unsaturated hydraulic conductivities during the experiments were 2.49 {times} 10{sup {minus}8} cm/s for the Yucca Mountain vitric member and 1.16 {times} 10{sup {minus}8} cm/s for the zeolitized nonwelded tuff.

  14. Fabrication of cubic spinel MnCo2O4 nanoparticles embedded in graphene sheets with their improved lithium-ion and sodium-ion storage properties

    NASA Astrophysics Data System (ADS)

    Chen, Chang; Liu, Borui; Ru, Qiang; Ma, Shaomeng; An, Bonan; Hou, Xianhua; Hu, Shejun

    2016-09-01

    Cubic Spinel MnCo2O4/graphene sheets (MCO/GS) nanocomposites are synthesized by a facile hydrothermal method with a subsequent annealing process. Nano-sized MnCo2O4 particles are evenly embedded in paper-like graphene sheets, possessing a unique nanoparticles-on-sheets hybrid nanostructure, with particle size around 20-50 nm. Owing to the special nanoparticles-on-sheets structures, MCO/GS nanocomposites have an outstanding electrochemical performance for rechargeable energy storage devices. As an anode material for lithium-ion batteries, MCO/GS electrodes exhibit high reversible discharge capacities (1350.4 mAh g-1 at the initial rate of 100 mA g-1), excellent rate capability (462.1 mAh g-1 at a current rate of 4000 mA g-1) and outstanding cycling performance (584.3 mAh g-1 at 2000 mA g-1 after 250 cycles). Meanwhile, as an anode material for sodium-ion batteries, MCO/GS electrodes also exhibit comparably promising electrochemical characteristics. Greatly improved electrochemical properties can be assigned to the special advantageous nanostructures. Besides, the existence of graphene sheets is beneficial to the transportation of ions/electrons during battery operation. The outstanding electrochemical performance demonstrates that the lithium/sodium storage capability of MCO/GS nanocomposites is highly promising for high-capacity batteries.

  15. Selenite transiently represses transcription of photosynthesis-related genes in potato leaves.

    PubMed

    Poggi, Valeria; Del Vescovo, Valerio; Di Sanza, Claudio; Negri, Rodolfo; Hochkoeppler, Alejandro

    2008-01-01

    A striking response of potato leaves to aspersion with selenite was observed at the transcriptional level by means of cDNA microarrays analysis. This response is characterized by a general transient repression of genes coding for components of photosynthetic systems and of other light-regulated genes. In particular, maximal repression was observed 8 h after selenite aspersion, while 24 h after the treatment a complete recovery of normal transcriptional levels was detected. Another general feature of the transcriptional response to selenite is represented by the transcriptional induction of genes related to amino acid metabolism, and to stress defense; interestingly, two genes coding for glutathione S-transferases were found early-induced upon selenite treatment. PMID:17846914

  16. Combination of Fenretinide and Selenite Inhibits Proliferation and Induces Apoptosis in Ovarian Cancer Cells

    PubMed Central

    Liu, Jie; Li, Jia; Zhang, Jian-Fang; Xin, Xiao-Yan

    2013-01-01

    The combination of fenretinide and selenite on ovarian cancer cells was investigated to assess its effects on proliferation and ability to induce apoptosis. Our results showed that fenretinide and selenite in combination significantly suppress the proliferation of ovarian cancer cells and induced apoptosis (including reactive oxygen species generation, and the loss of mitochondrial membrane potential) compared with either drug used alone. The caspase3/9-dependent pathway was triggered significantly in combination treatment, and moreover, the AMPK pathway also mediated the apoptosis induction in fenretinide and selenite combination. Fenretinide and selenite combination treatment was demonstrated to suppress tumor growth in vivo, this drug combination has been thus found to have an enhanced anti-tumor effect on ovarian cancers cells. PMID:24192821

  17. Selenite suppression of cadmium-induced testicular apoptosis.

    PubMed

    Jones, M M; Xu, C; Ladd, P A

    1997-01-15

    The characteristic apoptotic ladder-like patterns of rat testicular DNA on agarose gel electrophoresis which results from treatment with CdCl2 are suppressed by the administration of Na2SeO3. The examination of testicular tissue using an ELISA programmed cell death detection procedure confirmed this selenite suppression of cadmium-induced apoptosis. The administration of the Na2SeO3 at either 0.5, 1, 2 h prior to or 0.5, 1, 2 h after the administration of the CdCl2 appear to be almost equally effective at suppressing the apoptotic response. These results are in accord with previous studies on the Na2SeO3 suppression of cadmium induced necrotic changes in tissues and suggest that Na2SeO3 interferes with both necrosis and apoptosis. PMID:9020518

  18. Preparation and Characterization of Selenium Incorporated Guar Gum Nanoparticle and Its Interaction with H9c2 Cells

    PubMed Central

    Soumya, Rema Sreenivasan; Vineetha, Vadavanath Prabhakaran; Reshma, Premachandran Latha; Raghu, Kozhiparambil Gopalan

    2013-01-01

    This study deals with the preparation and characterization of selenium incorporated guar gum nanoparticle (SGG), and its effect on H9c2 cardiomyoblast. Herein, nanoprecipitation techniques had been employed for the preparation of SGG nanoparticle. The prepared nanoparticle had been subjected to various types of analytical techniques like transmission electron microscopy (TEM), X-ray diffraction (XRD) and particle size analysis to confirm the characteristics of nanoparticle as well as for selenium incorporation. Physical characterization of nanoparticle showed that the size of nanoparticles increase upto ∼69–173 nm upon selenium incorporation from ∼41–132 nm. Then the prepared nanoparticles were evaluated for its effect on H9c2 cells. In this regard, the effect of nanoparticle on various vital parameters of H9c2 cells was studied. Parameters like cell viability, uptake of selenium incorporated guar gum nanoparticle by the cells, effect of SGG on DNA integrity, apoptosis, reactive oxygen species generation, alteration in transmembrane potential of mitochondria and cytoskeletal integrity had been investigated. Viability results showed that up to 25 nM of SGG was safe (10.31%) but beyond that it induces cytotoxicity. Cellular uptake of selenium showed that cell permeability for SGG is significantly high compared to normal selenium (7.2 nM of selenium for 25 nM SGG compared with 5.2 nM selenium for 25 nM sodium selenite). There was no apoptosis with SGG and also it protects DNA from hydroxyl radical induced breakage. Likewise no adverse effect on mitochondria and cytoskeleton was observed for 25 nM of SGG. Overall results reveal that SGG is highly suitable for biomedical research application. PMID:24098647

  19. Enhanced physicochemical properties of chitosan/whey protein isolate composite film by sodium laurate-modified TiO2 nanoparticles.

    PubMed

    Zhang, Wei; Chen, Jiwang; Chen, Yue; Xia, Wenshui; Xiong, Youling L; Wang, Hongxun

    2016-03-15

    Chitosan/whey protein isolate film incorporated with sodium laurate-modified TiO2 nanoparticles was developed. The nanocomposite film was characterized by scanning electron microscopy, X-ray diffraction and differential scanning calorimetry, and investigated in physicochemical properties as color, tensile strength, elongation at break, water vapor permeability and water adsorption isotherm. Our results showed that the nanoparticles improved the compatibility of whey protein isolate and chitosan. Addition of nanoparticles increased the whiteness of chitosan/whey protein isolate film, but decreased its transparency. Compared with binary film, the tensile strength and elongation at break of nanocomposite film were increased by 11.51% and 12.01%, respectively, and water vapor permeability was decreased by 7.60%. The equilibrium moisture of nanocomposite film was lower than binary film, and its water sorption isotherm of the nanocomposite film fitted well to Guggenheim-Anderson-deBoer model. The findings contributed to the development of novel food packaging materials. PMID:26794738

  20. Glutathione peroxidase activity and chemical forms of selenium in tissues of rats given selenite or selenomethionine

    SciTech Connect

    Beilstein, M.A.; Whanger, P.D.

    1988-05-01

    Glutathione peroxidase (GPx) activity and deposition of selenium (Se) were examined in tissues of rats given dietary Se for 7 wk as either selenite or selenomethionine (SeMet) with 75Se radiotracer of the same chemical form. On the basis of Se:75Se ratio, all tissues of the rats fed selenite were equilibrated with the dietary source, but tissues of the SeMet fed animals maintained a ratio of Se:75Se greater than the dietary ratio. Deposition of dietary Se and 75Se was higher in most tissues of rats fed SeMet. Muscle 75Se was the largest single tissue pool of 75Se in both groups accounting for one-third of recovered 75Se in the rats fed selenite, and one-half of recovered 75Se in the rats fed SeMet. Tissue GPx activities were not different between the two dietary groups. The proportion of Se as GPx in tissues was highest in erythrocytes of the rats fed selenite (.81) and lowest in testes and epididymides of the rats fed SeMet (.009). The proportion of Se present in cytosolic GPx was consistently higher in tissues of rats fed selenite. Erythrocytes of the rats fed SeMet had more 75Se associated with hemoglobin, and muscle cytosols of the rats fed selenite had more 75Se associated with the G-protein. The proportion of 75Se as SeMet determined by ion exchange chromatography of tissue hydrolysates was higher in tissues of rats fed SeMet (highest in muscle and hemoglobin, 70%, and lowest in testes, 16%). In contrast, selenocysteine was the predominant form of Se present in tissues of rats given selenite. These results indicate that the form of Se administered will influence the form in the tissues, the percentage of Se with GPx and the body burden of Se.

  1. Evaluation of the of antibacterial efficacy of polyvinylpyrrolidone (PVP) and tri-sodium citrate (TSC) silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Dey, Arindam; Dasgupta, Abhirup; Kumar, Vijay; Tyagi, Aakriti; Verma, Anita Kamra

    2015-09-01

    We present silver nanoparticles as the new age broad spectrum antibiotic. Siver nanoparticles exhibit unique physical and chemical properties that make them suitable for understanding their biological potential as antimicrobials. In this study, we explored the antibacterial activity of silver nanoparticles (TSC-AgNPs) and silver nanoparticles doped with polyvinylpyrrolidone (PVP-AgNPs) against Gram-negative and Gram-positive bacteria, Escherichia coli (DH5α) and Staphylococcus aureus, (ATCC 13709). Nucleation and growth kinetics during the synthesis process of AgNPs were precisely controlled using citrate (TSC) and further doped with polyvinylpyrrolidone (PVP). This resulted in the formation of two different sized nanoparticles 34 and 54 nm with PDI of 0.426 and 0.643. The physical characterization was done by nanoparticle tracking analysis and scanning electron microscopy, the results of which are in unison with the digital light scattering data. We found the bactericidal effect for both TSC-AgNPs and PVP-AgNPs to be dose-dependent as determined by the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against E. coli and S. aureus. Interestingly, we also observed that AgNPs showed enhanced antimicrobial activity with a MIC of 26.75 and 13.48 µg/ml for E. coli and S. aureus, respectively, while MBC for AgNPs are 53.23 and 26.75 µg/ml for E. coli and S. aureus, respectively. Moreover, AgNPs showed increased DNA degradation as observed confirming its higher efficacy as antibacterial agent than the PVP doped AgNPs.

  2. [Dynamic effects of commonly co-existing anions on the removal of selenite from groundwater by nanoscale zero-valent iron].

    PubMed

    Yang, Wen-Jun; Guo, Ying-Qing; Du, Er-Deng

    2014-05-01

    Batch experiments are used to research selenite removal from groundwater by nanoscale zero-valent iron (nZVI) , and dynamic effects of commonly co-existing anions on the removal of selenite are also investigated. The results showed that under anoxic conditions,when nZVI dose was 0.1 g.L-1 , the concentration of Se( IV)/sodium chloride was 100 micromol.L-1/0. 01 mol L-1 , pH = 7.0, T = 25 degrees C +/- 1 degrees C, auto-adding 1 mmol.L -1 CO(2-)(3) or SO(2-)(4) , 5 mg. L -1 humic acid (HA), the removals of Se( IV ) were obviously inhibited. The weak effect on the removal of Se( IV) was observed when added 0. 5 mmol L- Ca2+ or Mg2 ,while concentrations of Ca2+ and Mg2+ were 3 mmol L-1 and 3 mmol L-1 respectively, removal efficiency of Se( IV) were evidently decreased. Without coexisting ions, Se( IV) were totally removed in 20 min, while with co-existing ions, removal efficiency of Se( NV) were achieved 100% in 30 min. Bivalent iron tended to stationary with the remove of Se( WV) in reaction processes. ORP rapidly decreased from positive to negative in the process of reaction, which illustrated the process of remove Se( IV) by nZVI was the reduction reaction. PMID:25055668

  3. In-tube magnetic solid phase microextraction of some fluoroquinolones based on the use of sodium dodecyl sulfate coated Fe3O4 nanoparticles packed tube.

    PubMed

    Manbohi, Ahmad; Ahmadi, Seyyed Hamid

    2015-07-23

    In-tube magnetic solid phase microextraction (in-tube MSPME) of fluoroquinolones from water and urine samples based on the use of sodium dodecyl sulfate (SDS) coated Fe3O4 nanoparticles packed tube has been reported. After the preparation of Fe3O4 nanoparticles (NPs) by a batch synthesis, these NPs were introduced into a stainless steel tube by a syringe and then a strong magnet was placed around the tube, so that the Fe3O4 NPs were remained in the tube and the tube was used in the in-tube SPME-HPLC/UV for the analysis of fluoroquinolones in water and urine samples. Plackett-Burman design was employed for screening the variables significantly affecting the extraction efficiency. Then, the significant factors were more investigated by Box-Behnken design. Calibration curves were linear (R(2)>0.990) in the range of 0.1-1000μgL(-1) for ciprofloxacin (CIP) and 0.5-500μgL(-1) for enrofloxacin (ENR) and ofloxacin (OFL), respectively. LODs for all studied fluoroquinolones ranged from 0.01 to 0.05μgL(-1). The main advantages of this method were rapid and easy automation and analysis, short extraction time, high sensitivity, possibility of fully sorbent collection after analysis, wide linear range and no need to organic solvents in extraction. PMID:26231896

  4. Selenite induces DNA damage and specific mitochondrial degeneration in human bladder cancer cells.

    PubMed

    Řezáčová, K; Čáňová, K; Bezrouk, A; Rudolf, E

    2016-04-01

    We have investigated the cytotoxicity and specific effects of selenite in human bladder cancer cell line RT-112 and its clonogenic variant RT-112 HB. Selenite inhibited cell growth and proliferation in both cell lines. Treated cells developed extensive vacuolization which was dose independent but occurring in differing time frames. Ultrastructure analysis revealed that the observed vacuoles are damaged mitochondria and potentially other subcellular compartments. Selenite-specific effects on mitochondria were further confirmed by mitochondrial membrane potential analysis, changes in ATP production and generation of superoxide. Simultaneously, selenite induced DNA damage in treated cells with activation of p53, PARP-1 and JNK and suppressed autophagy. Cells ultimately died via a combination of apoptosis, necrosis and a distinct type of cell death featuring "vacuolar shrinkage", loss of adherence and absence of secondary necrosis as well as other classical markers of either apoptosis or autophagy. The significant presence of so called necroptosis was also not confirmed as the specific inhibitor necrostatin-1 could not prevent cell death. These results thus confirm the toxicity of selenite in bladder cancer cells while pointing at potentially new mechanism of action of this compound in this model. PMID:26718266

  5. Selenite reduction by Shewanella oneidensis MR-1 is mediated by fumarate reductase in periplasm

    PubMed Central

    Li, Dao-Bo; Cheng, Yuan-Yuan; Wu, Chao; Li, Wen-Wei; Li, Na; Yang, Zong-Chuang; Tong, Zhong-Hua; Yu, Han-Qing

    2014-01-01

    In situ reduction of selenite to elemental selenium (Se(0)), by microorganisms in sediments and soils is an important process and greatly affects the environmental distribution and the biological effects of selenium. However, the mechanism behind such a biological process remains unrevealed yet. Here we use Shewanella oneidensis MR-1, a widely-distributed dissimilatory metal-reducing bacterium with a powerful and diverse respiration capability, to evaluate the involvement of anaerobic respiration system in the microbial selenite reduction. With mutants analysis, we identify fumarate reductase FccA as the terminal reductase of selenite in periplasm. Moreover, we find that such a reduction is dependent on central respiration c-type cytochrome CymA. In contrast, nitrate reductase, nitrite reductase, and the Mtr electron transfer pathway do not work as selenite reductases. These findings reveal a previously unrecognized role of anaerobic respiration reductases of S. oneidensis MR-1 in selenite reduction and geochemical cycles of selenium in sediments and soils. PMID:24435070

  6. Draft Genome Sequence of a Selenite- and Tellurite-Reducing Marine Bacterium, Lysinibacillus sp. Strain ZYM-1

    PubMed Central

    Zhao, Yonghe; Dong, Yuxuan; Zhang, Yiwen; Che, Lin; Pan, Haixia

    2016-01-01

    Lysinibacillus sp. ZYM-1, a Gram-positive strain isolated from marine sediments, reduces selenite and tellurite efficiently. Meanwhile, it also exhibits high resistance to Zn2+ and Mn2+. Here, we report the draft genome sequence of strain ZYM-1, which contains genes related to selenite and tellurite reduction and also metal resistance. PMID:26769938

  7. The microbial impact on the sorption behaviour of selenite in an acidic, nutrient-poor boreal bog.

    PubMed

    Lusa, M; Bomberg, M; Aromaa, H; Knuutinen, J; Lehto, J

    2015-09-01

    (79)Se is among the most important long lived radionuclides in spent nuclear fuel and selenite, SeO3(2-), is its typical form in intermediate redox potential. The sorption behaviour of selenite and the bacterial impact on the selenite sorption in a 7-m-deep profile of a nutrient-poor boreal bog was studied using batch sorption experiments. The batch distribution coefficient (Kd) values of selenite decreased as a function of sampling depth and highest Kd values, 6600 L/kg dry weight (DW), were observed in the surface moss and the lowest in the bottom clay at 1700 L/kg DW. The overall maximum sorption was observed at pH between 3 and 4 and the Kd values were significantly higher in unsterilized compared to sterilized samples. The removal of selenite from solution by Pseudomonas sp., Burkholderia sp., Rhodococcus sp. and Paenibacillus sp. strains isolated from the bog was affected by incubation temperature and time. In addition, the incubation of sterilized surface moss, subsurface peat and gyttja samples with added bacteria effectively removed selenite from the solution and on average 65% of selenite was removed when Pseudomonas sp. or Burkholderia sp. strains were used. Our results demonstrate the important role of bacteria for the removal of selenite from the solution phase in the bog environment, having a high organic matter content and a low pH. PMID:26048060

  8. The yeast Aft2 transcription factor determines selenite toxicity by controlling the low affinity phosphate transport system.

    PubMed

    Pérez-Sampietro, María; Serra-Cardona, Albert; Canadell, David; Casas, Celia; Ariño, Joaquín; Herrero, Enrique

    2016-01-01

    The yeast Saccharomyces cerevisiae is employed as a model to study the cellular mechanisms of toxicity and defense against selenite, the most frequent environmental selenium form. We show that yeast cells lacking Aft2, a transcription factor that together with Aft1 regulates iron homeostasis, are highly sensitive to selenite but, in contrast to aft1 mutants, this is not rescued by iron supplementation. The absence of Aft2 strongly potentiates the transcriptional responses to selenite, particularly for DNA damage- and oxidative stress-responsive genes, and results in intracellular hyperaccumulation of selenium. Overexpression of PHO4, the transcriptional activator of the PHO regulon under low phosphate conditions, partially reverses sensitivity and hyperaccumulation of selenite in a way that requires the presence of Spl2, a Pho4-controlled protein responsible for post-transcriptional downregulation of the low-affinity phosphate transporters Pho87 and Pho90. SPL2 expression is strongly downregulated in aft2 cells, especially upon selenite treatment. Selenite hypersensitivity of aft2 cells is fully rescued by deletion of PHO90, suggesting a major role for Pho90 in selenite uptake. We propose that the absence of Aft2 leads to enhanced Pho90 function, involving both Spl2-dependent and independent events and resulting in selenite hyperaccumulation and toxicity. PMID:27618952

  9. In vivo synthesis of selenium nanoparticles by Halococcus salifodinae BK18 and their anti-proliferative properties against HeLa cell line.

    PubMed

    Srivastava, Pallavee; Braganca, Judith M; Kowshik, Meenal

    2014-01-01

    Nanoparticles synthesis by bacteria and yeasts has been widely reported, however, synthesis using halophilic archaea is still in a nascent stage. This study aimed at the intracellular synthesis of selenium nanoparticles (SeNPs) by the haloarchaeon Halococcus salifodinae BK18 when grown in the presence of sodium selenite. Crystallographic characterization of SeNPs by X-ray diffraction, Selected area electron diffraction, and transmission electron microscopy exhibited rod shaped nanoparticles with hexagonal crystal lattice, a crystallite domain size of 28 nm and an aspect ratio (length:diameter) of 13:1. Energy disruptive analysis of X-ray analysis confirmed the presence of selenium in the nano-preparation. The nitrate reductase enzyme assay and the inhibitor studies indicated the involvement of NADH-dependent nitrate reductase in SeNPs synthesis and metal tolerance. The SeNPs exhibited good anti-proliferative properties against HeLa cell lines while being non-cytotoxic to normal cell line model HaCat, suggesting the use of these SeNPs as cancer chemotherapeutic agent. This is the first study on selenium nanoparticles synthesis by haloarchaea. PMID:25219897

  10. Protamine zinc insulin combined with sodium selenite improves glycometabolism in the diabetic KKAy mice

    PubMed Central

    Lu, Juan; Ji, Wenjun; Zhao, Mei; Wang, Meng; Yan, Wenhui; Chen, Mingxia; Ren, Shuting; Yuan, Bingxiang; Wang, Bing; Chen, Lina

    2016-01-01

    Long-term, high dosage protamine zinc insulin (PZI) treatments produce adverse reactions. The trace element selenium (Se) is a candidate for the prevention of diabetes due to anti-oxidative stress activity and the regulation of glycometabolism. In this study, we aimed to investigate the anti-diabetic effects of a combination of PZI and Se on type 2 diabetes. Diabetic KKAy mice were randomized into the following groups: model group and groups that were subcutaneously injected with PZI, Se, high or low dose PZI + Se for 6 weeks. PZI combined with Se decreased the body weight and fasting blood glucose levels. Moreover, this treatment also improved insulin tolerance, as determined by the reduced values from the oral glucose tolerance test and insulin tolerance test, and increased insulin levels and insulin sensitivity index. PZI combined with Se ameliorated skeletal muscle and β-cell damage and the impaired mitochondrial morphology. Oxidative stress was also reduced. Furthermore, PZI combined with Se upregulated phosphatidylinositol 3-kinase (PI3K) and downregulated protein tyrosine phosphatase 1B (PTP1B). Importantly, the low dosage combination produced effects similar to PZI alone. In conclusion, PZI combined with Se improved glycometabolism and ameliorated the tissue and mitochondrial damage, which might be associated with the PI3K and PTP1B pathways. PMID:27212152

  11. Protamine zinc insulin combined with sodium selenite improves glycometabolism in the diabetic KKAy mice.

    PubMed

    Lu, Juan; Ji, Wenjun; Zhao, Mei; Wang, Meng; Yan, Wenhui; Chen, Mingxia; Ren, Shuting; Yuan, Bingxiang; Wang, Bing; Chen, Lina

    2016-01-01

    Long-term, high dosage protamine zinc insulin (PZI) treatments produce adverse reactions. The trace element selenium (Se) is a candidate for the prevention of diabetes due to anti-oxidative stress activity and the regulation of glycometabolism. In this study, we aimed to investigate the anti-diabetic effects of a combination of PZI and Se on type 2 diabetes. Diabetic KKAy mice were randomized into the following groups: model group and groups that were subcutaneously injected with PZI, Se, high or low dose PZI + Se for 6 weeks. PZI combined with Se decreased the body weight and fasting blood glucose levels. Moreover, this treatment also improved insulin tolerance, as determined by the reduced values from the oral glucose tolerance test and insulin tolerance test, and increased insulin levels and insulin sensitivity index. PZI combined with Se ameliorated skeletal muscle and β-cell damage and the impaired mitochondrial morphology. Oxidative stress was also reduced. Furthermore, PZI combined with Se upregulated phosphatidylinositol 3-kinase (PI3K) and downregulated protein tyrosine phosphatase 1B (PTP1B). Importantly, the low dosage combination produced effects similar to PZI alone. In conclusion, PZI combined with Se improved glycometabolism and ameliorated the tissue and mitochondrial damage, which might be associated with the PI3K and PTP1B pathways. PMID:27212152

  12. Anthraquinones and flavonoids of Cassia tora leaves ameliorate sodium selenite induced cataractogenesis in neonatal rats.

    PubMed

    Sreelakshmi, V; Abraham, Annie

    2016-02-01

    The present study was undertaken to evaluate the efficacy of Cassia tora leaves, an edible plant traditionally used for eye ailments, in preventing experimental cataractogenesis. Cataract is the leading cause of irreversible visual impairment worldwide characterized by the cloudiness or opacification of the lens due to the disturbance of even distribution of lens proteins and lipids. A significant number of epidemiological studies have suggested the potential role of herbal medicine in the prevention of cataract by maintaining lens architecture. The study was conducted in neonatal rat pups of 8-10 days old with an ethyl acetate fraction of Cassia tora leaves (ECT) administered by gastric intubation. After 30 days, the animals were sacrificed and various parameters such as redox status and gene expressions were evaluated in lenses. ECT administration caused a significant decrease in the onset and maturation of cataract, potentiated antioxidant defense and normalized lens crystallin expression against cataract induced animals. HPLC and ESI-MS analysis of ECT revealed the presence of flavonoids and anthraquinones. Thus, the present study indicates the therapeutic potential of Cassia tora leaves in preventing cataract and the effect is endorsed by the presence of antioxidants in Cassia tora leaves. PMID:26786764

  13. Decreased levels of peripheral leukocytes following sodium selenite treatment in female mice

    SciTech Connect

    Hogan, G.R.

    1986-08-01

    Selenium is known to be an essential micronutrient to a number of animal species (Schwarz 1961). Above its trace levels, however, selenium accumulation has long been known to induce deleterious conditions in domestic animals and in humans. Selenium has been reported to induce a hemolytic anemia, alter the configuration of plasma protein, reduce the synthesis of hemoglobin, depress packed red blood cell volume, and accumulate in renal and hepatic tissues. There are substantial data in regard to selenium effects on the erythrocyte component of peripheral blood, but there is an obvious deficiency in such information concerning the effects of selenium on the leukocyte component of blood. The major purpose of this investigation is to focus upon the effects of selenium on formed elements of the blood, and specifically, the leukocytes. Following three separate treatments of selenium, the number and class of peripheral leukocytes were determined as a function of time following administration of the selenium salt.

  14. Comparative effects of selenate and selenite on selenium accumulation, morphophysiology, and glutathione synthesis in Ulva australis.

    PubMed

    Schiavon, Michela; Pilon-Smits, Elizabeth A H; Citta, Anna; Folda, Alessandra; Rigobello, Maria Pia; Dalla Vecchia, Francesca

    2016-08-01

    The capacity of Ulva australis Areschoug to tolerate and accumulate selenium (Se) supplied in the form of selenate or selenite was investigated. The macroalga was provided for 3 and 7 days with concentrations of selenate (Na2SeO4) or selenite (Na2SeO3) ranging from 0 to 400 μM. U. australis exhibited the highest ability to accumulate selenium when fed with 100 μM selenate and 200 μM selenite after 7 days, and accumulation values were respectively 25 and 36 ppm Se. At the same concentrations, stimulation of the synthesis of chlorophylls and carotenoids was observed. Elevated doses of selenate or selenite decreased Se accumulation inside algal cells, perhaps through repression of membrane transporters. This effect was more pronounced in thalli cultivated with selenate. There were no morphological and ultrastructural alterations in thalli exposed to Se. However, selenite induced the increase of the oxidized fraction of glutathione (GSSG), perhaps because of its capacity to bind the thiol group of reduced glutathione (GSH). In conclusion, this study highlights the capacity of U. australis to resist to very high concentrations of selenite and selenate, which are normally toxic to other organisms. Also, the lack of bioconcentration in U. australis indicates that this alga does not facilitate delivery of Se in the food chain and remains safe for consumption when it grows in water bodies contaminated with Se. Its potential for the removal of excess Se from water bodies appears limited. PMID:27083905

  15. Response of duckweed to various concentrations of selenite.

    PubMed

    Mechora, Špela; Stibilj, Vekoslava; Germ, Mateja

    2015-02-01

    The uptake of Se(IV) and its effects on the physiological and biochemical characteristics of duckweed (Lemna minor L.) have been studied. Duckweed plants were cultivated in controlled conditions for 7 weeks in different concentrations of Na selenite: 0.5, 1, 2, 5 (exposed 42 days) and 10 mg Se L(-1) (survived 7-21 days). The addition of 1 mg Se L(-1) did not negatively affect photochemical efficiency whilst respiratory potential increased in weeks 2-4 compared to control. The addition of 1 mg Se(IV) L(-1) increased the amount of chlorophyll a in weeks 3 and 4 and the amount of carotenoids in weeks 1, 3 and 5. Concentrations of 2 and 5 mg Se L(-1) negatively affected photochemical efficiency in weeks 3 and 4, and increased respiratory potential in comparison to the control in weeks 1-4, whilst beyond week 4, the respiratory potential decreased. Plants exposed to the highest concentration of Se(IV) had to be replaced twice during the experiment because they were dying. That was reflected in photochemical efficiency as well as in respiratory potential, which decreased in time. The content of Se in duckweed increased with the increasing concentration of Se: plants growing in 0.5 mg Se L(-1) contained 0.9 mg Se g(-1) DM and plants exposed to 5 mg Se L(-1) contained 5.8 mg Se g(-1) DM. The group of plants exposed to 10 mg Se L(-1) for 21 days contained 19.5 mg Se g(-1) DM. Our study revealed that duckweed absorbed high amount of Se(IV) from the water. PMID:25028325

  16. Synthesis and evaluation of poly(Sodium 2-Acrylamido-2-Methylpropane Sulfonate-co-Styrene)/magnetite nanoparticle composites as corrosion inhibitors for steel.

    PubMed

    El-Mahdy, Gamal A; Atta, Ayman M; Al-Lohedan, Hamad A

    2014-01-01

    Self-stabilized magnetic polymeric composite nanoparticles of coated poly-(sodium 2-acrylamido-2-methylpropane sulfonate-co-styrene)/magnetite (PAMPS-Na-co-St/Fe3O4) were prepared by emulsifier-free miniemulsion polymerization using styrene (St) as a monomer, 2-acrylamido-2-methylpropane sulfonic acid sodium salt (AMPS-Na) as an ionic comonomer, N,N-methylenebisacrylamide (MBA) as crosslinker, hexadecane (HD) as a hydrophobic solvent, and 2,2-azodiisobutyronitrile (AIBN) as an initiator in the presence of hydrophobic oleic acid coated magnetite particles. Hydrophobic oleic acid coated magnetite particles with an average size of about 7-10 nm were prepared with the new modified water-based magnetite ferrofluid, synthesized by a chemical modified coprecipitation method. The morphology and the particle size distributions of the crosslinked PAMPS-Na-co-St/Fe3O4 composite were observed and analyzed by transmission electron microscopy (TEM). The average Fe3O4 content of PAMPS-Na-co-St/Fe3O4 was determined by thermogravimetric analysis (TGA). The inhibitory action of PAMPS-Na-co-St/Fe3O4 towards steel corrosion in 1 M HCl solutions has been investigated by polarization and electrochemical impedance spectroscopy (EIS) methods. Polarization measurements indicate that PAMPS-Na-co-St/Fe3O4 acts as a mixed type-inhibitor and the inhibition efficiency increases with inhibitor concentration. The results of potentiodynamic polarization and EIS measurements clearly showed that the inhibition mechanism involves blocking of the steel surface by inhibitor molecules via adsorption. PMID:24487568

  17. Antimony nanoparticles anchored on interconnected carbon nanofibers networks as advanced anode material for sodium-ion batteries

    NASA Astrophysics Data System (ADS)

    Hou, Hongshuai; Jing, Mingjun; Yang, Yingchang; Zhang, Yan; Song, Weixin; Yang, Xuming; Chen, Jun; Chen, Qiyuan; Ji, Xiaobo

    2015-06-01

    Interconnected carbon nanofibers networks (ICNNs) prepared through the carbonization of polypyrrole (PPy) precursor are utilized as conductive pathways and buffer to improve the Na storage performance of antimony (Sb) as anode for sodium-ion batteries (SIBs). The as-obtained Sb/ICNNs composite exhibits excellent cycle stability. The reversible capacity can remain 542.5 mAh g-1 with a high capacity retention of 96.7% after 100 cycles at a current density of 100 mA g-1. And the superior rate performance is also observed, the reversible capacity can still reach 325 mAh g-1 at a high current density of 3200 mA g-1. These great electrochemical performances observed above suggest that this type of composite can be a nice option for advanced SIBs anode materials and may be extended to other active materials/ICNNs composite electrode.

  18. Effect of silver nanoparticles on the spectral properties of rare-earth ions in a sodium borate glass

    NASA Astrophysics Data System (ADS)

    Obadina, Victor O.; Reddy, B. Rami

    2012-03-01

    Silver doped sodium borate glass was made by the melt quenching technique. As made glass, did not reveal any absorption transitions in the visible or ultraviolet region. Differential scanning calorimeter was used to measure glass transition temperature. Heat treated glass revealed absorption peak at 410 nm due to surface plasmon resonance. Under violet laser excitation the glass revealed emission at 450 - 620 nm, whose lifetimes are more than 30μs. Under near resonant excitation it revealed intense Raman scattering. We also made multielement oxide glasses co-doped with silver and Er3+ and performed spectroscopic studies. Energy upconversion was observed from Er3+ at 415 nm in a 2% Ag co-doped oxide glass but not in other glasses. Infrared to visible upconversion studies were performed in all these glasses under near-infrared laser excitation. 2% Ag doped glass exhibited enhanced upconversion signals from erbium than that of other glasses.

  19. Increasing Selenium and Yellow Pigment Concentrations in Foxtail Millet (Setaria italica L.) Grain with Foliar Application of Selenite.

    PubMed

    Ning, Na; Yuan, Xiang-Yang; Dong, Shu-Qi; Wen, Yin-Yuan; Gao, Zhen-Pan; Guo, Mei-Jun; Guo, Ping-Yi

    2016-03-01

    Although addition of selenium (Se) is known to increase Se in crops, it is unclear whether exogenous Se is linked to nutritional and functional components in foxtail millet (Setaria italica L.). In this study, we examined the potential of increasing Se and yellow pigment (YP) in foxtail millet grain by foliar application of Se. Field experiments were conducted during the growing season of foxtail millet in 2013 and 2014 to assess the effects of foliar spray of sodium selenite (10-210 g Se ha(-1)) on the yield, Se uptake and accumulation, total YP, and microminerals in the grain. Average grain yields with Se application were 5.60 and 4.53 t ha(-1) in the 2 years, showing no significant differences from the unfertilized control. However, grain Se concentration increased linearly with Se application rate, by 8.92 and 6.09 μg kg(-1) in the 2 years with application of 1 g Se ha(-1) (maximum grain recovery rates of Se fertilizer, 52 and 28 %). Likewise, total grain YP concentration markedly increased by 0.038 and 0.031 mg kg(-1) in the 2 years with application of 1 g Se ha(-1). Grain Mn, Cu, Fe, and Zn concentrations were not significantly affected by Se application. This study indicated that foliar application of Se effectively and reliably increased the concentrations of Se and YP in foxtail millet grain without affecting the yield or mineral micronutrient concentrations. Thus, foliar-applied selenite has a significant potential to increase the concentrations of selenium and YP (putative lutein (Shen, J Cereal Sci 61:86-93, 2015; Abdel-Aal, Cereal Chem 79:455-457, 2002; Abdel-Aal, J Agric Food Chem 55:787-794, 2007)) of foxtail millet and, thus, the health benefits of this crop. PMID:26201681

  20. An Azospira oryzae (syn Dechlorosoma suillum) Strain the Reduces Selenate and Selenite to Elemental Red Selenium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A bacterium that reduces the soluble selenium oxyanions, selenate and selenite, to insoluble elemental red selenium (Se0) was isolated from a laboratory reactor developed to remove selenate from groundwater. Gene sequence alignment of the 16S rRNA allowed identification of the isolate as Azospira o...

  1. Pseudomonas seleniipraecipitatus sp. nov.: A selenite reducing -proteobacteria isolated from soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Abstract: A Gram-negative, yellow pigmented bacterium designated strain CA5 that reduced selenite to elemental red selenium (Se0) was isolated from soil. 16S rRNA gene sequence alignment identified the isolate as a novel Pseudomonas sp. with P. argentinensis, P. flavescens and P. straminea as its c...

  2. REMOVAL OF SELENITE FROM GROUNDWATER BY RHIZOBIUM SP. STRAIN B1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenite is highly soluble, mobile and potentially toxic to humans and animals. In contrast, insoluble Se0 is not available for biological uptake and is generally non-toxic. Because of these contrasting properties, in-situ biological precipitation has been proposed as a remediation method to remov...

  3. ADSORPTION MECHANISMS AND TRANSPORT BEHAVIOR BETWEEN SELENATE AND SELENITE ON DIFFERENT SORBENTS

    SciTech Connect

    Snyder, Michelle MV; Um, Wooyong

    2014-04-30

    Adsorption of different oxidation species of selenium (Se), selenate (SeO42-) and selenite (SeO32-), with varying pHs (2 - 10) and ionic strengths (I = 0.01 M, 0.1 M and 1.0 M NaNO3) was measured on quartz, aluminum oxide, and synthetic iron oxide (ferrihydrite) using batch reactors to obtain a more detailed understanding of the adsorption mechanisms (e.g., inner- and outer-sphere complex). In addition to the batch experiments with single minerals contained in native Hanford Site sediment, additional batch adsorption studies were conducted with native Hanford Site sediment and groundwater as a function of 1) total Se concentration (from 0.01 to 10 mg L-1) and 2) soil to solution ratios (1:20 and 1:2 grams per mL). Results from these batch studies were compared to a set of saturated column experiments that were conducted with natural Hanford sediment and groundwater spiked with either selenite or selenate to observe the transport behavior of these species. Both batch and column results indicated that selenite adsorption was consistently higher than that of selenate in all experimental conditions used. These different adsorption mechanisms between selenite and selenate result in the varying mobility of Se in the subsurface environment and explain the dependence on the oxidation species.

  4. Effect of heavy metal co-contaminants on selenite bioreduction by anaerobic granular sludge.

    PubMed

    Mal, J; Nancharaiah, Y V; van Hullebusch, E D; Lens, P N L

    2016-04-01

    This study investigated bioreduction of selenite by anaerobic granular sludge in the presence of heavy metals and analyzed the fate of the bioreduced selenium and the heavy metals. Selenite bioreduction was not significantly inhibited in the presence of Pb(II) and Zn(II). More than 92% of 79 mg/L selenite was removed by bioreduction even in the presence of 150 mg/L of Pb(II) or 400mg/L of Zn(II). In contrast, only 65-48% selenite was bioreduced in the presence of 150-400 mg/L Cd(II). Formation of elemental selenium or selenide varied with heavy metal type and concentration. Notably, the majority of the bioreduced selenium (70-90% in the presence of Pb and Zn, 50-70% in the presence of Cd) and heavy metals (80-90% of Pb and Zn, 60-80% of Cd) were associated with the granular sludge. The results have implications in the treatment of selenium wastewaters and biogenesis of metal selenides. PMID:26836844

  5. Macroscopic experimental and modeling evaluation of selenite and selenate adsorption mechanisms on gibbsite

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenite Se(IV) and selenate Se(VI) selenium adsorption behavior was investigated on gibbsite as a function of solution pH and solution ionic strength. Adsorption of both Se redox states decreased with increasing solution pH. Electrophoretic mobility measurements showed downward shifts in point of...

  6. Predicting Selenite Adsorption by Soils Using Soil Chemical Parameters in the Constant Capacitance Model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The constant capacitance model, a chemical surface complexation model, was applied to selenite, Se(IV), adsorption on 36 soils selected for variation in soil chemical properties. The constant capacitance model was able to fit Se(IV) adsorption by optimizing one monodentate Se(IV) surface complexati...

  7. Rhizobium selenitireducens proteins involved in the reduction of selenite to elemental selenium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microbial based bioremediation barriers can remove the metalloid selenite (SeO3–2) from flowing groundwater. The organisms associated with the process include microorganisms from within the bacterial and archaeal domains that can reduce soluble SeO3–2 to the insoluble and reddish-colored elemental ...

  8. Structure of adsorption layer of silver nanoparticles in sodium bis(2-ethylhexyl) sulfosuccinate solutions in n-decane as observed by photon-correlation spectroscopy and nonaqueous electrophoresis.

    PubMed

    Bulavchenko, Alexander I; Popovetskiy, Pavel S

    2014-11-01

    Photon correlation spectroscopy, nonaqueous electrophoresis, and transmission electron microscopy were used to study the structure of silver nanoparticles (NPs) in n-decane, as a dependence of the concentration of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and temperature. If the concentration of AOT is lower than the critical micelle concentration (CMC), a silver NP is covered with a monolayer of AOT and reveals no electrophoretic mobility. At average concentrations (from CMC to 0.1 M) the hydrodynamic diameter of a NP does not change, but the ζ-potential increases from 0 to 110 mV. When the concentration of AOT increases from 0.1 to 1 M, ζ potential drops to 13 mV, and the hydrodynamic diameter increases to 90 nm. An increase in temperature to 70 °C leads to a reversible decrease in diameter to 40 nm. The hypothesis of clustering (polylayer adsorption) of "empty" micelles on silver NPs is proposed for the qualitative interpretation of the experimental data. PMID:25290335

  9. Sodium selenosulfate at an innocuous dose markedly prevents cisplatin-induced gastrointestinal toxicity

    SciTech Connect

    Li, Jun; Sun, Kang; Ni, Lijuan; Wang, Xufang; Wang, Dongxu; Zhang, Jinsong

    2012-02-01

    Our previous studies in mice revealed that two weeks short-term toxicity of sodium selenosulfate was significantly lower than that of sodium selenite, but selenium repletion efficacy of both compounds was equivalent. In addition, we showed that sodium selenosulfate reduced nephrotoxicity of cisplatin (CDDP) without compromising its anticancer activity, thus leading to a dramatic increase of cancer cure rate from 25% to 75%. Hydration has been used in clinical practice to reduce CDDP-induced nephrotoxicity, but it cannot mitigate CDDP-induced gastrointestinal toxicity. The present work investigated whether sodium selenosulfate is a potential preventive agent for the gastrointestinal toxicity. In tumor-bearing mice, sodium selenosulfate was administered at a dose of 9.5 μmol/kg daily for 11 days, CDDP alone resulted in diarrhea by 88% on day 12, whereas the co-administration of CDDP and sodium selenosulfate dramatically reduced diarrhea to 6% (p < 0.0001). Such a prominent protective effect promoted us to evaluate the safety potential of long-term sodium selenosulfate application. Mice were administered with sodium selenosulfate or sodium selenite for 55 days at the doses of 12.7 and 19 μmol/kg. The low-dose sodium selenite caused growth suppression and hepatotoxicity which were aggravated by the high-dose, leading to 40% mortality rate, but no toxic symptoms were observed in the two sodium selenosulfate groups. Altogether these results clearly show that sodium selenosulfate at an innocuous dose can markedly prevent CDDP-induced gastrointestinal toxicity. -- Highlights: ►Cisplatin resulted in diarrhea in mice by 88%. ►i.p. selenosulfate at 9.5 μmol/kg daily for 11 days reduced diarrhea to 6%. ►i.p. selenosulfate at 19 μmol/kg daily for 55 days was not toxic. ►i.p. selenite at 19 μmol/kg daily for 55 days was lethal. ►Innocuous dose of selenosulfate greatly prevents cisplatin-induced diarrhea.

  10. [Effects of selenite addition on selenium absorption, root morphology and physiological characteristics of rape seedlings].

    PubMed

    Liu, Xin-wei; Wang, Qiao-lan; Duan, Bi-hui; Lin, Ya-meng; Zhao, Xiao-hu; Hu, Cheng-xiao; Zhao, Zhu-qing

    2015-07-01

    Abstract: The rape (Brassica napus L. cv. Xiangnongyou 571) was chosen as the experimental material to undergo solution cultivation at seedling stage to investigate the effects of selenite addition on the selenium (Se) absorption and distribution, root morphology and physiological characteristics of rape seedlings. The results showed that the bioaccumulation ability of Se decreased significantly with increasing the Se application rate, but the Se distribution coefficient remained around 0.9 with no significant influence. The application of 10 µmol . L-1 selenite stimulated the growth of rape seedlings through improving the root physiological characteristics and root morphology significantly, including significantly increasing the production of superoxide radical (O2∙-) rate and the activities of superoxide dismutase (SOD), peroxidase (POD) and fungal catalase (CAT) in the root system, which resulted in a reduction of the lipids peroxidation (MDA) content as much as 26.0%, consequently increasing the root activity as much as 17.4%. The promoting degrees of selenite on root morphological parameters were from strong to weak in such a tendency: root volume > total surface area > number of root forks > total root length > number of root tips > average diameter. However, such positive effects had no significant difference with those in treatment with 1 µmol . L-1 selenite, indicating that small amounts (≤ 10 Lmol . L-1) of selenite were able to increase the activity of antioxidant enzymes and reduce the content of MDA in root system, which could increase root activity and improve root morphology, hence increased the biomass of rape seedlings. PMID:26710631

  11. nanoparticles

    NASA Astrophysics Data System (ADS)

    Andreu-Cabedo, Patricia; Mondragon, Rosa; Hernandez, Leonor; Martinez-Cuenca, Raul; Cabedo, Luis; Julia, J. Enrique

    2014-10-01

    Thermal energy storage (TES) is extremely important in concentrated solar power (CSP) plants since it represents the main difference and advantage of CSP plants with respect to other renewable energy sources such as wind, photovoltaic, etc. CSP represents a low-carbon emission renewable source of energy, and TES allows CSP plants to have energy availability and dispatchability using available industrial technologies. Molten salts are used in CSP plants as a TES material because of their high operational temperature and stability of up to 500°C. Their main drawbacks are their relative poor thermal properties and energy storage density. A simple cost-effective way to improve thermal properties of fluids is to dope them with nanoparticles, thus obtaining the so-called salt-based nanofluids. In this work, solar salt used in CSP plants (60% NaNO3 + 40% KNO3) was doped with silica nanoparticles at different solid mass concentrations (from 0.5% to 2%). Specific heat was measured by means of differential scanning calorimetry (DSC). A maximum increase of 25.03% was found at an optimal concentration of 1 wt.% of nanoparticles. The size distribution of nanoparticle clusters present in the salt at each concentration was evaluated by means of scanning electron microscopy (SEM) and image processing, as well as by means of dynamic light scattering (DLS). The cluster size and the specific surface available depended on the solid content, and a relationship between the specific heat increment and the available particle surface area was obtained. It was proved that the mechanism involved in the specific heat increment is based on a surface phenomenon. Stability of samples was tested for several thermal cycles and thermogravimetric analysis at high temperature was carried out, the samples being stable.

  12. Pharmacological and toxicological effects of co-exposure of human gingival fibroblasts to silver nanoparticles and sodium fluoride

    PubMed Central

    Inkielewicz-Stepniak, Iwona; Santos-Martinez, Maria Jose; Medina, Carlos; Radomski, Marek W

    2014-01-01

    Background Silver nanoparticles (AgNPs) and fluoride (F) are pharmacological agents widely used in oral medicine and dental practice due to their anti-microbial/anti-cavity properties. However, risks associated with the co-exposure of local cells and tissues to these xenobiotics are not clear. Therefore, we have evaluated the effects of AgNPs and F co-exposure on human gingival fibroblast cells. Methods Human gingival fibroblast cells (CRL-2014) were exposed to AgNPs and/or F at different concentrations for up to 24 hours. Cellular uptake of AgNPs was examined by transmission electron microscopy. Downstream inflammatory effects and oxidative stress were measured by real-time quantitative polymerase chain reaction (PCR) and reactive oxygen species (ROS) generation. Cytotoxicity and apoptosis were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and real-time quantitative PCR and flow cytometry, respectively. Finally, the involvement of mitogen-activated protein kinases (MAPK) was studied using Western blot. Results We found that AgNPs penetrated the cell membrane and localized inside the mitochondria. Co-incubation experiments resulted in increased oxidative stress, inflammation, and apoptosis. In addition, we found that co-exposure to both xenobiotics phosphorylated MAPK, particularly p42/44 MAPK. Conclusion A combined exposure of human fibroblasts to AgNPs and F results in increased cellular damage. Further studies are needed in order to evaluate pharmacological and potentially toxicological effects of AgNPs and F on oral health. PMID:24729703

  13. Biogenic selenium and tellurium nanoparticles synthesized by environmental microbial isolates efficaciously inhibit bacterial planktonic cultures and biofilms

    PubMed Central

    Zonaro, Emanuele; Lampis, Silvia; Turner, Raymond J.; Qazi, S. Junaid S.; Vallini, Giovanni

    2015-01-01

    The present study deals with Se0- and Te0-based nanoparticles bio-synthesized by two selenite- and tellurite-reducing bacterial strains, namely Stenotrophomonas maltophilia SeITE02 and Ochrobactrum sp. MPV1, isolated from polluted sites. We evidenced that, by regulating culture conditions and exposure time to the selenite and tellurite oxyanions, differently sized zero-valent Se and Te nanoparticles were produced. The results revealed that these Se0 and Te0 nanoparticles possess antimicrobial and biofilm eradication activity against Escherichia coli JM109, Pseudomonas aeruginosa PAO1, and Staphylococcus aureus ATCC 25923. In particular, Se0 nanoparticles exhibited antimicrobial activity at quite low concentrations, below that of selenite. Toxic effects of both Se0 and Te0 nanoparticles can be related to the production of reactive oxygen species upon exposure of the bacterial cultures. Evidence so far achieved suggests that the antimicrobial activity seems to be strictly linked to the dimensions of the nanoparticles: indeed, the highest activity was shown by nanoparticles of smaller sizes. In particular, it is worth noting how the bacteria tested in biofilm mode responded to the treatment by Se0 and Te0 nanoparticles with a susceptibility similar to that observed in planktonic cultures. This suggests a possible exploitation of both Se0 and Te0 nanoparticles as efficacious antimicrobial agents with a remarkable biofilm eradication capacity. PMID:26136728

  14. Sodium alginate-cross-linked polymyxin B sulphate-loaded solid lipid nanoparticles: Antibiotic resistance tests and HaCat and NIH/3T3 cell viability studies.

    PubMed

    Severino, Patrícia; Chaud, Marco V; Shimojo, Andrea; Antonini, Danilo; Lancelloti, Marcelo; Santana, Maria Helena A; Souto, Eliana B

    2015-05-01

    Polymyxins are a group of antibiotics with a common structure of a cyclic peptide with a long hydrophobic tail. Polymyxin B sulphate (PLX) has cationic charge, which is an obstacle for the efficient loading into Solid Lipid Nanoparticles (SLN). In the present paper, we describe an innovative method to load PLX into SLN to achieve the sustained release of the drug. PLX was firstly cross-linked with sodium alginate (SA) at different ratios (1:1, 1:2 and 1:3 SA/PLX), and loaded into SLN produced by high pressure homogenization (HPH). Optimized SLN were produced applying 500bar pressure and 5 homogenization cycles. The best results were obtained with SA/PLX (1:1), recording 99.08±1.2% for the association efficiency of the drug with SA, 0.99±10g for the loading capacity and 212.07±5.84% degree of swelling. The rheological profile of aqueous SA solution followed the typical behaviour of concentrated polymeric solutions, whereas aqueous SA/PLX solution exhibited a gel-like dynamic behaviour. Micrographs show that SA/PLX depicted a porous and discontinuous amorphous phase in different ratios. The encapsulation efficiency of SA/PLX (1:1) in SLN, the mean particle diameter, polydispersity index and zeta potential were, respectively, 82.7±5.5%; 439.5±20.42nm, 0.241±0.050 and -34.8±0.55mV. The effect of SLN on cell viability was checked in HaCat and NIH/3T3 cell lines, and the minimal inhibitory concentrations (MIC) were determined in Pseudomonas aeruginosa strains. SA/PLX-loaded SLN were shown to be less toxic than free PLX. Minimal inhibitory concentrations (MIC) showed the presence of the cross-linker polymer-drug complex, and SLN were shown to enhance MIC in the evaluated strains. PMID:25863712

  15. Characterization of the selenotrisulfide formed by reaction of selenite with end-capped phytochelatin-2.

    PubMed

    Spain, Stephen M; Rabenstein, Dallas L

    2004-03-01

    The phytochelatins are a family of peptides synthesized by plants in response to exposure to heavy metals and metalloids, including selenium in the form of selenite. The amino acid sequence of the phytochelatin (PC) peptides is (gamma-Glu-Cys)n-Gly, where n typically ranges from 2 to 5. In this paper, the products of the reaction of selenite with an end-capped analogue of PC2, Ac-(gamma-Glu-Cys)2-Gly-NH2, are characterized. Selenite reacts with Ac-(gamma-Glu-Cys)2-Gly-NH2 (Ac-PC2-NH2) to form a compound that contains an intramolecular selenotrisulfide (-SSeS-)-linkage (Se[Ac-PC2-NH2]) and oxidized Ac-PC2-NH2. Both Se[Ac-PC2-NH2] and oxidized Ac-PC2-NH2 were isolated by HPLC and were characterized by MALDI-TOF mass spectrometry, by two-dimensional 1H and 13C NMR and, in the case of Se[Ac-PC2-NH2], by 77Se NMR. Using dihedral angles determined from vicinal 1H-1H coupling constants as constraints for the conformations around the Cys(CalphaH)-Cys(CbetaH) bonds, structures were predicted for the most abundant form of both compounds by Monte Carlo molecular mechanics simulations. PMID:15214417

  16. The abilities of selenium dioxide and selenite ion to coordinate DNA-bound metal ions and decrease oxidative DNA damage.

    PubMed

    Hart, William E; Marczak, Steven P; Kneller, Andrew R; French, Robert A; Morris, Daniel L

    2013-08-01

    Several transition metals react with H2O2 and produce reactive oxygen species (ROS) responsible for oxidative damage linked to many diseases and disorders, and species that form coordination complexes with these metal ions show promise as antioxidants. The present study demonstrates that metal-mediated radical and non-radical oxidative DNA damage decreases when selenium dioxide (SeO2) and sodium selenite (Na2SeO3) are present. Radical-induced damage is associated with production of 8-hydroxy-2'-deoxyguanosine (8-OH-dG), which arises from ROS generated at or near the guanine base, and the selenium compounds reduce Fe(II)-, Cr(III)- and Cu(II)-mediated radical damage to differing degrees based on the identity of the metal ion and the order in which the metals, selenium compounds and DNA are combined. Radical damage arising from Fe(II) and Cr(III) decreases substantially when they are pre-incubated with the selenium compounds prior to adding DNA. Non-radical damage is associated with oxidation of the adenine base in the presence of high H2O2 concentrations through an ionic mechanism, and this type of damage also decreases significantly when the selenium compounds are allowed to interact with the metal ions before adding DNA. Fluorescence studies using dihydrodichlorofluorescein diacetate (DCF-DA) to probe ROS formation indicate that the majority of the SeO2- and SeO3(2-)-metal systems in combination with H2O2 (no DNA present) produce ROS to the same degree as the metal/H2O2 systems in the absence of the selenium compounds, suggesting that selenium-metal complexes react with H2O2 in a sacrificial manner that protects DNA from oxidative damage. PMID:23628661

  17. Selenite reduction by the obligate aerobic bacterium Comamonas testosteroni S44 isolated from a metal-contaminated soil

    PubMed Central

    2014-01-01

    Background Selenium (Se) is an essential trace element in most organisms but has to be carefully handled since there is a thin line between beneficial and toxic concentrations. Many bacteria have the ability to reduce selenite (Se(IV)) and (or) selenate (Se(VI)) to red elemental selenium that is less toxic. Results A strictly aerobic bacterium, Comamonas testosteroni S44, previously isolated from metal(loid)-contaminated soil in southern China, reduced Se(IV) to red selenium nanoparticles (SeNPs) with sizes ranging from 100 to 200 nm. Both energy dispersive X-ray Spectroscopy (EDX or EDS) and EDS Elemental Mapping showed no element Se and SeNPs were produced inside cells whereas Se(IV) was reduced to red-colored selenium in the cytoplasmic fraction in presence of NADPH. Tungstate inhibited Se(VI) but not Se(IV) reduction, indicating the Se(IV)-reducing determinant does not contain molybdenum as co-factor. Strain S44 was resistant to multiple heavy and transition metal(loid)s such as Se(IV), As(III), Cu(II), and Cd(II) with minimal inhibitory concentrations (MIC) of 100 mM, 20 mM, 4 mM, and 0.5 mM, respectively. Disruption of iscR encoding a transcriptional regulator negatively impacted cellular growth and subsequent resistance to multiple heavy metal(loid)s. Conclusions C. testosteroni S44 could be very useful for bioremediation in heavy metal(loid) polluted soils due to the ability to both reduce toxic Se(VI) and Se(IV) to non-toxic Se (0) under aerobic conditions and to tolerate multiple heavy and transition metals. IscR appears to be an activator to regulate genes involved in resistance to heavy or transition metal(loid)s but not for genes responsible for Se(IV) reduction. PMID:25098921

  18. Sodium Test

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? Sodium Share this page: Was this page helpful? Also known as: Na Formal name: Sodium Related tests: Chloride , Bicarbonate , Potassium , Electrolytes , Osmolality , Basic ...

  19. Selenite activates the ATM kinase-dependent DNA repair pathway in human osteosarcoma cells with mitochondrial dysfunction.

    PubMed

    Wojewoda, Marta; Walczak, Jarosław; Duszyński, Jerzy; Szczepanowska, Joanna

    2015-06-01

    Mitochondrial dysfunction and reactive oxygen species (ROS) induced oxidative damage are implicated in the pathogenesis of several human diseases. Based on our previous findings that ROS level was higher in human osteosarcoma cybrids--Neuropathy, Ataxia and Retinitis Pigmentosa (NARP) and was reduced by selenite treatment, this study was designed to elucidate the effects of selenite administration on oxidative and nitrosative damage to lipids, proteins and DNA. Oxidative and nitrosative damage to lipids and proteins was not increased in NARP cybrids or mitochondrial DNA-lacking Rho0 cells (displaying mitochondrial dysfunction) when compared with control WT cells. However, we found the enhanced formation of DNA double-strand breaks based on the level of histone γH2AX (phosphorylated at Ser 139), which is known to be phosphorylated by ATM (Ataxia Telangiectasia Mutated) kinase in response to DNA damage. Selenite increased the activity of ATM kinase in NARP cybrids and Rho0 cells without concomitant increase in levels of histone γH2AX. Activation of the ATM kinase-dependent DNA repair pathway triggered by selenite could not be associated with enhanced DNA damage but might rather result from selenite-induced activation of ATM-dependent DNA repair mechanisms which could account for protective effects of this agent. PMID:25862479

  20. The ubiquitin–proteasome pathway protects Chlamydomonas reinhardtii against selenite toxicity, but is impaired as reactive oxygen species accumulate

    PubMed Central

    Vallentine, Patrick; Hung, Chiu-Yueh; Xie, Jiahua; Van Hoewyk, Doug

    2014-01-01

    The ubiquitin–proteasome pathway (UPP) coordinates a myriad of physiological processes in higher plants, including abiotic stress responses, but it is less well characterized in algal species. In this study, the green alga Chlamydomonas reinhardtii was used to gain insights into the role of the UPP during moderate and severe selenite stress at three different time points. The data indicate that activity of the UPP in response to selenium (Se) stress was both time and dose dependent. Moderate selenite stress increased proteasome activity, protein ubiquitination and the proteasomal removal of malformed selenoproteins. However, severe Se stress caused by prolonged selenite treatment or high selenite concentration decreased proteasome activity, inhibited protein ubiquitination and prevented the proteasomal removal of selenoproteins. The UPP impairment during severe Se stress was associated with the observed accumulation of reactive oxygen species (ROS), including mitochondrial superoxide. Additionally, proteasomal inhibition decreased the concentration of chlorophyll in cultures challenged with Se. Therefore, although the UPP protects Chlamydomonas against Se stress, severe oxidative stress induced by selenite toxicity likely hinders the UPP's capacity to mediate a stress response. The possibility that stress tolerance in plants is dependent upon optimal UPP activity and maintenance is discussed. PMID:25301821

  1. Development of a dual-analyte fluorescent sensor for the determination of bioactive nitrite and selenite in water samples.

    PubMed

    Martínez-Tomé, M J; Esquembre, R; Mallavia, R; Mateo, C R

    2010-01-20

    Nitrite and selenium are two bioactive compounds found in the environment which show beneficial effects for health at low levels but have toxic effects at higher doses. Consequently, quantification of both analytes in water samples results of great interest in areas such as biomedicine, food technology and environmental analysis. In a recent paper, we immobilized the inclusion complex formed between 2,3-diaminonaphthalene (DAN) and 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD) in a sol-gel matrix, in order to prepare a highly sensitive reagentless fluorescence-based sensor for the specific measurement of nitrite. Here we have explored the possibility of using the sol-gel immobilized complex to quantify selenite (Se (IV)), the more toxic form of selenium, as well as to act as a dual-analyte chemical sensor for simultaneous quantification of both nitrite and selenite in aqueous samples. Results show that (a) inclusion of DAN in HP-beta-CD and its subsequent immobilization in a sol-gel matrix do not modify the reactivity of DAN against selenite, (b) the reaction product formed (4,5-benzopiazselenol) remains into the cyclodextrin increasing considerably its fluorescence quantum yield and avoiding, therefore, its extraction into organic solvents, (c) the developed sensor can detect selenite concentrations at submicromolar level with a minimum detection limit of 13 nM, (d) the immobilized system is able to simultaneously quantify nitrite and selenite at submicromolar concentrations in natural water samples with no further sample pre-treatment. PMID:19297113

  2. Superoxide generated from the glutathione-mediated reduction of selenite damages the iron-sulfur cluster of chloroplastic ferredoxin.

    PubMed

    Fisher, Brian; Yarmolinsky, Dmitry; Abdel-Ghany, Salah; Pilon, Marinus; Pilon-Smits, Elizabeth A; Sagi, Moshe; Van Hoewyk, Doug

    2016-09-01

    Selenium assimilation in plants is facilitated by several enzymes that participate in the transport and assimilation of sulfate. Manipulation of genes that function in sulfur metabolism dramatically affects selenium toxicity and accumulation. However, it has been proposed that selenite is not reduced by sulfite reductase. Instead, selenite can be non-enzymatically reduced by glutathione, generating selenodiglutathione and superoxide. The damaging effects of superoxide on iron-sulfur clusters in cytosolic and mitochondrial proteins are well known. However, it is unknown if superoxide damages chloroplastic iron-sulfur proteins. The goals of this study were twofold: to determine whether decreased activity of sulfite reductase impacts selenium tolerance in Arabidopsis, and to determine if superoxide generated from the glutathione-mediated reduction of selenite damages the iron-sulfur cluster of ferredoxin. Our data demonstrate that knockdown of sulfite reductase in Arabidopsis does not affect selenite tolerance or selenium accumulation. Additionally, we provide in vitro evidence that the non-enzymatic reduction of selenite damages the iron-sulfur cluster of ferredoxin, a plastidial protein that is an essential component of the photosynthetic light reactions. Damage to ferredoxin's iron-sulfur cluster was associated with formation of apo-ferredoxin and impaired activity. We conclude that if superoxide damages iron-sulfur clusters of ferredoxin in planta, then it might contribute to photosynthetic impairment often associated with abiotic stress, including toxic levels of selenium. PMID:27182957

  3. Construction of selenium nanoparticles/β-glucan composites for enhancement of the antitumor activity.

    PubMed

    Jia, Xuewei; Liu, Qingye; Zou, Siwei; Xu, Xiaojuan; Zhang, Lina

    2015-03-01

    We report on a green procedure for the stabilization of selenium nanoparticles (SeNPs) by a naturally occurring β-glucan with triple helical conformation known as Lentinan (t-LNT) in water after denaturing into single chains (s-LNT) at 140 °C. The results demonstrated that the s-LNT can interact with SeNPs through Se-O-H interaction. Transmission electron microscopy (TEM), energy dispersive X-ray (EDX) spectra, UV/vis, X-ray diffraction (XRD) and dynamic light scattering (DLS) showed that s-LNT coated SeNPs to form a stable nano-composite Se/s-LNT, leading to good dispersion of SeNPs. Especially, the as-prepared Se/s-LNT composite in the solution could remain homogeneous and translucent for 30 days without any precipitates. Different size distribution of SeNPs was prepared by simply controlling the concentrations of selenite sodium and the corresponding reducing agent ascorbic acid. The size effect of SeNPs on anti-tumor activity was revealed that the SeNPs with more evenly particle size distribution show the higher anticancer activity. PMID:25498656

  4. Elucidation of the mechanism of reaction between S2O8(2-), Selenite and Mn2+ in aqueous solution and limestone-gypsum FGD liquor.

    PubMed

    Akiho, Hiroyuki; Ito, Shigeo; Matsuda, Hiromitsu; Yoshioka, Toshiaki

    2013-10-01

    The mechanism of reaction between peroxodisulfate ion (S2O8(2-)), selenite (Se(IV)O3(2-)) and Mn(2+) as an inhibitor of selenite oxidation was studied using aqueous solutions composed of commercial reagents, as well as limestone-gypsum flue gas desulfurization (FGD) liquors sampled from coal fired power plants. The oxidation of selenite to selenate (Se(VI)O4(2-)) is promoted by the sulfate ion radical (SO4(-)) which results from decomposition of S2O8(2-). In the presence of Mn(2+), selenite oxidation was prevented due to the difference in rates of reaction with SO4(-). The ratio of the oxidation rate constants of selenite and Mn(2+) with SO4(-) was determined over a temperature range of 40-60 °C, and was found to be little influenced by the various coexisting components in FGD liquors. PMID:24015970

  5. Variations in the accumulation, localization and rate of metabolization of selenium in mature Zea mays plants supplied with selenite or selenate.

    PubMed

    Longchamp, Mélanie; Castrec-Rouelle, Maryse; Biron, Philippe; Bariac, Thierry

    2015-09-01

    Quantification of selenium bioavailability from foods is a key challenge following the discovery of the antioxidant role of this micronutrient in human health. This study presents the uptake, accumulation and rate of metabolization in mature Zea mays plants grown in hydroponic solution supplemented with selenate or selenite. Selenium content was lower in plants supplemented with selenate and accumulated mainly in the leaves compared with selenite-treated plants where the selenium was retained in the roots. Selenite-treated grains accumulated more selenium. Selenate was metabolized less than selenite in whole plants, but in grains selenium was present exclusively as organic selenium compounds. For humans, the bioavailability of organic selenium was evaluated at 90% compared with only 50% for inorganic forms. Our results show that the potential for selenium bioavailability is increased with selenite treatment. PMID:25842318

  6. Sorption kinetic study of selenite and selenate onto a high and low pressure aged iron oxide nanomaterial

    PubMed Central

    Gonzalez, Christina M.; Hernandez, Jeffrey; Peralta-Videa, Jose R.; Botez, Cristian E.; Parsons, Jason G.; Gardea-Torresdey, Jorge L.

    2015-01-01

    The sorption of selenite (SeO32−) and selenate (SeO42−) onto Fe3O4 nanomaterials produced by non microwave-assisted or microwave-assisted synthetic techniques was investigated through use of the batch technique. The phase of both synthetic nanomaterials was determined to be magnetite by X-ray diffraction. The average grain sizes of non microwave-assisted and microwave-assisted synthetic Fe3O4 were determined to be 27 and 25 nm, respectively through use of the Scherrer's equation. Sorption of selenite was pH independent in the pH range of 2-6, while sorption of selenate decreased at pH 5 and 6. The addition of Cl− had no significant effect on selenite or selenate binding, while the addition of NO3− only affected selenate binding to the microwave assisted Fe3O4. A decrease of selenate binding to both synthetic particles was observed after the addition of SO42− while selenite binding was not affected. The addition of PO43− beginning at concentrations of 0.1 ppm had the most prominent effect on the binding of both selenite and selenate. The capacities of binding, determined through the use of Langmuir isotherm, were found to be 1923 and 1428 mg Se/kg of non microwave-assisted Fe3O4 and 2380 and 2369 mg Se/kg of microwave-assisted Fe3O4 for selenite and selenate, respectively. PMID:21907486

  7. Syntheses, structures and characterizations of three novel vanadium selenites with organically bonded copper/nickel complex

    NASA Astrophysics Data System (ADS)

    Qian, Cheng; Kong, Fang; Mao, Jiang-Gao

    2016-06-01

    A series of vanadium selenites covalently bonded with metal-organic complex, namely, Ni(2,2-bipy)2V2O4(SeO3)2 (1), Cu(2,2-bipy)V2O4(SeO3)2·0.5H2O (2) and Cu2(2,2-bipy)2V5O12(SeO3)2 (3) (2,2-bipy=2,2-bipyridine) have been hydrothermally synthesized and structurally characterized. They exhibit three different structural dimensions, from 0D cluster, 1D chain to 2D layer. Compound 1 features a 0D {Ni(2,2-bipy)2V2O4(SeO3)2}2 dimeric cluster composed of two {Ni(2,2-bipy)2}2+ moieties connected by the {V4O8(SeO3)4}4- cluster. Compound 2 shows a 1D {Cu(2,2-bipy)V2O4(SeO3)2}n chain in which the {Cu2(2,2-bipy)2}4+ moieties are bridged by the {V4O8(SeO3)4}4- clusters. Compound 3 displays a 2D structure consisted of mixed valence vanadium selenites layers {VIVVV4SeIV2O18}n4- and {Cu(2,2-bipy)}2+ complex moieties. The adjacent layers are further interconnected via π-π interactions between the 2,2-bipy ligands exhibiting an interesting 3D supramolecular architecture. Both compound 1 and 2 contain a new {V4O8(SeO3)4}4- cluster and compound 3 exhibits the first 2D vanadate polyhedral layer in vanadium selenites/tellurites with organic moieties.

  8. Polymorphism of Metallic Sodium under Nanoconfinement.

    PubMed

    Uskov, A V; Nefedov, D Yu; Charnaya, E V; Haase, J; Michel, D; Kumzerov, Yu A; Fokin, A V; Bugaev, A S

    2016-01-13

    (23)Na NMR studies of sodium nanoparticles confined to porous glass with the 3.5 nm mean pore size were carried out. The emergence of the second component of the NMR line was observed below 240 K that evidences the occurrence of another modification of metallic sodium. The phase transition temperature is much higher than the martensite transformation temperature in bulk sodium. PMID:26714113

  9. Nanocrystalline hydroxyapatite enriched in selenite and manganese ions: physicochemical and antibacterial properties.

    PubMed

    Kolmas, Joanna; Groszyk, Ewa; Piotrowska, Urszula

    2015-12-01

    In this work, we used the co-precipitation method to synthesize hydroxyapatite (Mn-SeO3-HA) containing both selenium IV (approximately 3.60 wt.%) and manganese II (approximately 0.29 wt.%). Pure hydroxyapatite (HA), hydroxyapatite-containing manganese (II) ions (Mn-HA), and hydroxyapatite-containing selenite ions alone (SeO3-HA), prepared with the same method, were used as reference materials. The structures and physicochemical properties of all the obtained samples were investigated. PXRD studies showed that the obtained materials were homogeneous and consisted of apatite phase. Introducing selenites into the hydroxyapatite crystals considerably affects the size and degree of ordering. Experiments with transmission electron microscopy (TEM) showed that Mn-SeO3-HA crystals are very small, needle-like, and tend to form agglomerates. Fourier transform infrared spectroscopy (FT-IR) and solid-state nuclear magnetic resonance (ssNMR) were used to analyze the structure of the obtained material. Preliminary microbiological tests showed that the material demonstrated antibacterial activity against Staphylococcus aureus, yet such properties were not confirmed regarding Escherichia coli. PACS codes: 61, 76, 81. PMID:26138453

  10. Nanocrystalline hydroxyapatite enriched in selenite and manganese ions: physicochemical and antibacterial properties

    NASA Astrophysics Data System (ADS)

    Kolmas, Joanna; Groszyk, Ewa; Piotrowska, Urszula

    2015-07-01

    In this work, we used the co-precipitation method to synthesize hydroxyapatite (Mn-SeO3-HA) containing both selenium IV (approximately 3.60 wt.%) and manganese II (approximately 0.29 wt.%). Pure hydroxyapatite (HA), hydroxyapatite-containing manganese (II) ions (Mn-HA), and hydroxyapatite-containing selenite ions alone (SeO3-HA), prepared with the same method, were used as reference materials. The structures and physicochemical properties of all the obtained samples were investigated. PXRD studies showed that the obtained materials were homogeneous and consisted of apatite phase. Introducing selenites into the hydroxyapatite crystals considerably affects the size and degree of ordering. Experiments with transmission electron microscopy (TEM) showed that Mn-SeO3-HA crystals are very small, needle-like, and tend to form agglomerates. Fourier transform infrared spectroscopy (FT-IR) and solid-state nuclear magnetic resonance (ssNMR) were used to analyze the structure of the obtained material. Preliminary microbiological tests showed that the material demonstrated antibacterial activity against Staphylococcus aureus, yet such properties were not confirmed regarding Escherichia coli. PACS codes: 61, 76, 81

  11. Effect of selected anti-cataract agents on opacification in the selenite cataract model.

    PubMed

    Hiraoka, T; Clark, J I; LI, X Y; Thurston, G M

    1996-01-01

    A systematic study of the anti-cataract activity of 14 reagents was conducted using the selenite model. The reagents or their derivatives were identified from literature reports of their potential effectiveness against cataract formation. The effects of each reagent were measured on the phase separation temperature, Tc, of lens homogenate in vitro. Tc is a direct measure of molecular interactions leading to protein aggregation. The protective effect of a single subcutaneous injection of each reagent [at a dose of 1.5 mmol (kg body weight)-1] on lens opacification was evaluated in vivo using rats administered selenite [at a dose of 19 mumol (kg body weight)-1] to initiate cataract formation. The strongest effects on lens opacification in vivo were observed with reagents having the strongest effect on Tc, in vitro. The weakest effects in vivo were observed with the reagents having the weakest effect on Tc, in vitro. The results were suggestive of a relationship between the effect of a reagent on Tc and protection against cataract formation in vivo. PMID:8674506

  12. Sodium Oxybate

    MedlinePlus

    ... if you use or have ever used street drugs, or if you have overused prescription medications. Sodium oxybate may be harmful when taken by people other than the person for whom it was prescribed. Do not sell or give your sodium oxybate to anyone else; selling or sharing it is against the law. Store ...

  13. Bioavailability, toxicity and biotransformation of selenium in midge (Chironomus dilutus) larvae exposed via water or diet to elemental selenium particles, selenite, or selenized algae.

    PubMed

    Gallego-Gallegos, Mercedes; Doig, Lorne E; Tse, Justin J; Pickering, Ingrid J; Liber, Karsten

    2013-01-01

    Elemental selenium (Se) is generally considered to be biologically inert due to its insolubility in water. It is a common form of Se in sediment near uranium mining and milling operations in northern Saskatchewan, Canada. Nanosized particles of many materials exhibit different properties compared with their bulk phases, in some cases posing health and ecological risks. Here we investigated the bioavailability and toxicity of Se nanoparticles (SeNPs) using 10-day waterborne and dietary exposures to larvae of Chironomus dilutus, a common benthic invertebrate. For comparison, larvae were also exposed to waterborne dissolved selenite and to dietary selenomethionine as selenized algae. Larval Se accumulation was evaluated using graphite furnace atomic absorption spectroscopy or inductively coupled plasma mass spectroscopy for total Se and X-ray absorption spectroscopy for Se chemical speciation. Exposure to nanoparticulate Se resulted in Se bioaccumulation, at high concentrations, inhibiting larval growth in both waterborne and dietary exposures; larvae predominantly accumulated selenomethionine-like species regardless of uptake route or form of Se tested. Despite the observed Se accumulation, our findings suggest there is little risk of direct SeNP toxicity to benthic invertebrates in Se-contaminated sediments in northern Saskatchewan. Nevertheless, elemental Se in sediments may be biologically available and may contribute directly or indirectly to the risk of Se toxicity to egg-laying vertebrates (fish and piscivorous birds) in Se-contaminated aquatic systems. It thus may be necessary to include elemental Se as a source of potential Se exposure in ecological risk assessments. PMID:23234498

  14. Biogenic selenium nanoparticles: current status and future prospects.

    PubMed

    Wadhwani, Sweety A; Shedbalkar, Utkarsha U; Singh, Richa; Chopade, Balu A

    2016-03-01

    Selenium nanoparticles (SeNPs) are gaining importance in the field of medicine owing to their antibacterial and anticancer properties. SeNPs are biocompatible and non-toxic compared to the counterparts, selenite (SeO3 (-2)) and selenate (SeO4 (-2)). They can be synthesized by physical, chemical, and biological methods and have distinct bright orange-red color. Biogenic SeNPs are stable and do not aggregate owing to natural coating of the biomolecules. Various hypotheses have been proposed to describe the mechanism of microbial synthesis of SeNPs. It is primarily a two-step reduction process from SeO4 (-2) to SeO3 (-2) to insoluble elemental selenium (Se(0)) catalyzed by selenate and selenite reductases. Phenazine-1-carboxylic acid and glutathione are involved in selenite reduction. Se factor A (SefA) and metalloid reductase Rar A present on the surface of SeNPs confer stability to the nanoparticles. SeNPs act as potent chemopreventive and chemotherapeutic agents. Conjugation with antibiotics enhances their anticancer efficacy. These also have applications in nanobiosensors and environmental remediation. PMID:26801915

  15. Selenite Treatment Inhibits LAPC-4 Tumor Growth and Prostate-Specific Antigen Secretion in a Xenograft Model of Human Prostate Cancer

    SciTech Connect

    Bhattacharyya, Rumi S.; Husbeck, Bryan; Feldman, David; Knox, Susan J.

    2008-11-01

    Purpose: Selenium compounds have known chemopreventive effects on prostate cancer. However selenite, an inorganic form of selenium, has not been extensively studied as a treatment option for prostate cancer. Our previous studies have demonstrated the inhibition of androgen receptor expression and androgen stimulated prostate-specific antigen (PSA) expression by selenite in human prostate cancer cell lines. In this study, we investigated the in vivo effects of selenite as a therapy to treat mice with established LAPC-4 tumors. Methods and Materials: Male mice harboring androgen-dependent LAPC-4 xenograft tumors were treated with selenite (2 mg/kg intraperitoneally three times per week) or vehicle for 42 days. In addition, androgen-independent LAPC-4 xenograft tumors were generated in female mice over 4 to 6 months. Once established, androgen-independent LAPC-4 tumor fragments were passaged into female mice and were treated with selenite or vehicle for 42 days. Changes in tumor volume and serum PSA levels were assessed. Results: Selenite significantly decreased androgen-dependent LAPC-4 tumor growth in male mice over 42 days (p < 0.001). Relative tumor volume was decreased by 41% in selenite-treated animals compared with vehicle-treated animals. The inhibition of LAPC-4 tumor growth corresponded to a marked decrease in serum PSA levels (p < 0.01). In the androgen-independent LAPC-4 tumors in female mice, selenite treatment decreased tumor volume by 58% after 42 days of treatment (p < 0.001). Conclusions: These results suggest that selenite may have potential as a novel therapeutic agent to treat both androgen-dependent and androgen-independent prostate cancer.

  16. High dietary intake of sodium selenite does not affect gene mutation frequency in rat colon and liver

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gene mutations have been implicated in the etiology of cancer. In the present study, we utilized Big Blue transgenic rats to evaluate the in vivo mutation frequency of the ' cII gene in rats fed either a Se-deficient (0 µg Se/g diet) or selenium-supplemented diet (2 µg Se/g diet) (n=6 rats/diet) and...

  17. High Dietary Intake of Sodium Selenite Does Not Affect Gene Mutation Frequency in Rat Colon and Liver

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previously we reported that both Se deficiency and Cu deficiency decreased plasma homocysteine (pHcys) and increased plasma glutathione (pGSH) in rats. We also showed that the catalytic subunit of glutamate-cysteine ligase (Gclc), which catalyzes the rate limiting step in glutathione biosynthesis, w...

  18. Possible new organoselenium supplement--evaluation of its influence on the kidneys in comparison with inorganic sodium selenite.

    PubMed

    Musik, Irena; Hordyjewska, Anna; Boguszewska-Czubara, Anna; Pasternak, Kazimierz

    2009-01-01

    The aim of this work was to evaluate the possibility of using of the new selenoorganic ring compound, 3-(o-chlorobenzoylamino)-2-(o-tolylimino)-4-methyl-4-selenazoline, as a selenium supplement by investigating the influence of its short-term administration on Se accumulation and antioxidant status in kidney. For 10 days, adolescent male Wistar rats were treated with saline (control group), Na(2)SeO(3) (Se-IN group) or the studied compound (Se-ORG group) (5 x 10(-4) mg Se/g of once a day) via a stomach tube. The selenium concentration, total antioxidant status (TAS), activities of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx), concentrations of ascorbic acid (AA) and reduced glutathione (GSH) and concentration of malonyldialdehyde (MDA) were determined in the kidney homogenates. TAS was significantly reduced in the Se-ORG group compared to the control. Reduced glutathione was markedly decreased in Se-treated animals compared to the control and in the Se-ORG group compared to the Se-IN group. Malonyldialdehyde was significantly increased in the Se-supplemented groups compared to the control group but considerably less so in the Se-ORG group. All other studied parameters displayed no significant differences. No increase in the accumulation of selenium and the partial impairment of the antioxidant status and enhancement of lipid peroxidation in the kidneys resulting from Se treatment could suggest that in the first period of administration, excess selenium was excreted with urine, leading to a disturbance of kidney functions. Comparison of the effect of our compound with that exerted by inorganic Na(2)SeO(3) suggests that the studied compound could be considered as a possible supplement after further investigations, including determination of selenium excretion with urine, as well as repetition of this study using a wide range of doses and periods of supplementation. PMID:19904012

  19. Reduction of Selenite to Red Elemental Selenium by Rhodopseudomonas palustris Strain N

    PubMed Central

    Li, Baozhen; Liu, Na; Li, Yongquan; Jing, Weixin; Fan, Jinhua; Li, Dan; Zhang, Longyan; Zhang, Xiaofeng; Zhang, Zhaoming; Wang, Lan

    2014-01-01

    The trace metal selenium is in demand for health supplements to human and animal nutrition. We studied the reduction of selenite (SeO3−2) to red elemental selenium by Rhodopseudomonas palustris strain N. This strain was cultured in a medium containing SeO3−2 and the particles obtained from cultures were analyzed using transmission electron microscopy (TEM), energy dispersive microanalysis (EDX) and X ray diffraction analysis (XRD). Our results showed the strain N could reduce SeO3−2 to red elemental selenium. The diameters of particles were 80–200 nm. The bacteria exhibited significant tolerance to SeO3−2 up to 8.0 m mol/L concentration with an EC50 value of 2.4 m mol/L. After 9 d of cultivation, the presence of SeO32− up to 1.0 m mol/L resulted in 99.9% reduction of selenite, whereas 82.0% (p<0.05), 31.7% (p<0.05) and 2.4% (p<0.05) reduction of SeO3−2 was observed at 2.0, 4.0 and 8.0 m mol/L SeO32− concentrations, respectively. This study indicated that red elemental selenium was synthesized by green technology using Rhodopseudomonas palustris strain N. This strain also indicated a high tolerance to SeO3−2. The finding of this work will contribute to the application of selenium to human health. PMID:24759917

  20. Sodium modified molybdenum sulfide via molten salt electrolysis as an anode material for high performance sodium-ion batteries.

    PubMed

    Wang, Shuai; Tu, Jiguo; Yuan, Yan; Ma, Rui; Jiao, Shuqiang

    2016-01-28

    The paper reports a facile and cost effective method for fabricating sodium molybdenum sulfide nanoparticles through using MoS2 sheets as the precursor by sodium-modification. The electrochemical performances of sodium molybdenum sulfide nanoparticles are studied as anode materials for sodium-ion batteries. The galvanostatic charge-discharge measurements have been performed in a voltage range of 0.01-2.6 V vs. Na(+)/Na under different current densities, using the as-prepared sodium molybdenum sulfide nanoparticles as a working electrode. Typically, the initial discharge and charge capacities of sodium molybdenum sulfide nanoparticles are 475 and 380 mA h g(-1), respectively, at a current density of 20 mA g(-1). The sodium molybdenum sulfide nanoparticles exhibit high capacity with a reversible discharge capacity of about 190 mA h g(-1) after 100 cycles. It should be emphasized that the discharge reaction consists of two steps which correspond to voltage plateaus of 0.93 V and 0.85 V vs. Na(+)/Na in the first discharge curve of the Na/MoS2 battery, respectively. But there is only one apparent voltage plateau in the Na/Na-Mo-S battery, and it reduces to below 0.5 V vs. Na(+)/Na, which can enhance the power density. All of the findings demonstrate that sodium molybdenum sulfide nanoparticles have steady cycling performance and environmental and cost friendliness as next generation secondary batteries. PMID:26744041

  1. Tellurite-, tellurate-, and selenite-based anaerobic respiration by strain CM-3 isolated from gold mine tailings.

    PubMed

    Maltman, Chris; Piercey-Normore, Michele D; Yurkov, Vladimir

    2015-09-01

    The newly discovered strain CM-3, a Gram-negative, rod-shaped bacterium from gold mine tailings of the Central Mine in Nopiming Provincial Park, Canada, is capable of dissimilatory anaerobic reduction of tellurite, tellurate, and selenite. CM-3 possesses very high level resistance to these oxides, both aerobically and anaerobically. During aerobic growth, tellurite and tellurate resistance was up to 1500 and 1000 µg/ml, respectively. In the presence of selenite, growth occurred at the highest concentration tested, 7000 µg/ml. Under anaerobic conditions, resistance was decreased to 800 µg/ml for the Te oxides; however, much like under aerobic conditions, growth with selenite still took place at 7000 µg/ml. In the absence of oxygen, CM-3 couples oxide reduction to an increase in biomass. Following an initial drop in viable cells, due to switching from aerobic to anaerobic conditions, there was an increase in CFU/ml greater than one order of magnitude in the presence of tellurite (6.6 × 10(3)-8.6 × 10(4) CFU/ml), tellurate (4.6 × 10(3)-1.4 × 10(5) CFU/ml), and selenite (2.7 × 10(5)-5.6 × 10(6) CFU/ml). A control culture without metalloid oxides showed a steady decrease in CFU/ml with no recovery. ATP production was also increased in the presence of each oxide, further indicating anaerobic respiration. Partial 16S rRNA gene sequencing revealed a 99.0 % similarity of CM-3 to Pseudomonas reactans. PMID:26254805

  2. Uptake of /sup 75/Se-selenite by brush border membrane vesicles from chick duodenum stimulated by vitamin D

    SciTech Connect

    Mykkanen, H.M.; Wasserman, R.H.

    1989-02-01

    Brush border membrane vesicles were isolated from mucosal homogenates of duodena from normal, rachitic and vitamin D-treated rachitic chicks using a discontinuous sucrose gradient, and further purified by glycerol gradient centrifugation. In vitro uptake of 75Se-selenite by purified brush border membrane vesicles was studied using a rapid filtration technique. The time course of 75Se uptake was non-linear; rapid initial binding was followed by a gradual decrease in the rate of uptake until an equilibrium value was reached at 60-120 min. The initial binding at 36 s was not affected by selenite concentration in the incubation buffer, while the fractional rate of uptake between the 36 s and 2 min time periods was clearly lower with 1 mM Se than with 4-100 microM Se. 75Se uptake did not show any dependency on the external Na-gradient, nor could it be inhibited by other anions (arsenate, phosphate). Treatment of rachitic chicks either with cholecalciferol (500 Iu, 72 h) or with 1,25(OH)2-cholecalciferol (0.5 microgram given 16 h prior to isolation of the vesicles) significantly enhanced 75Se uptake. A threefold excess of mannitol in the outside buffer reduced 75Se uptake by vesicles from vitamin D-deficient and D-treated chicks 60% and 35% respectively, but had no effect on vesicles from vitamin D-treated chicks preloaded with 75Se. Neither saponin treatment nor excess cold selenite could release the label from the vesicles preloaded with 75Se. These data are compatible with the hypothesis that selenite easily crosses the brush border membrane into the intravesicular space and, once inside, is tightly bound by the membrane.

  3. Acifluorfen, sodium

    Integrated Risk Information System (IRIS)

    Acifluorfen , sodium ; CASRN 62476 - 59 - 9 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcino

  4. Sodium diethyldithiocarbamate

    Integrated Risk Information System (IRIS)

    Sodium diethyldithiocarbamate ; CASRN 148 - 18 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Non

  5. Sodium fluoroacetate

    Integrated Risk Information System (IRIS)

    Sodium fluoroacetate ; CASRN 62 - 74 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogen

  6. Sodium azide

    Integrated Risk Information System (IRIS)

    Sodium azide ; CASRN 26628 - 22 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  7. Sodium cyanide

    Integrated Risk Information System (IRIS)

    Jump to main content . Integrated Risk Information System Recent Additions | Contact Us Search : All EPA IRIS • You are here : EPA Home • Research • Environmental Assessment • IRIS • IRIS Summaries Redirect Page As of September 28 , 2010 , the assessment summary for sodium cyanide is included in the

  8. Preparation and characterization of highly water-soluble magnetic Fe3O4 nanoparticles via surface double-layered self-assembly method of sodium alpha-olefin sulfonate

    NASA Astrophysics Data System (ADS)

    Li, Honghong; Qin, Li; Feng, Ying; Hu, Lihua; Zhou, Chunhua

    2015-06-01

    A kind of double-layered self-assembly sodium alpha-olefin sulfonate (AOS) capped Fe3O4 magnetic nanoparticles (Fe3O4-AOS-MN) with highly water-solubility was prepared by a wet co-precipitation method with a pH of 4.8. The resulting Fe3O4-AOS-MN could be dispersed into water to form stable magnetic fluid without other treatments. The result of X-ray diffraction (XRD) indicated that the Fe3O4-AOS-MN maintained original crystalline structure and exhibited a diameter of about 7.5 nm. The iron oxide phase of nanoparticles determined by Raman spectroscopy is Fe3O4. Transmission electron microscopy (TEM) analysis confirmed that the Fe3O4-AOS-MN with spherical morphology were uniformly dispersed in water. FT-IR spectroscopy (FT-IR) and thermo-gravimetric analysis (TGA) verified the successful preparation of Fe3O4-AOS-MN capped with double-layered self-assembled AOS. The corresponding capacities of monolayer chemical absorption and the second-layer self-assembly absorption were respectively 4.07 and 14.71 wt% of Fe3O4-MN, which were much lower than those of other surfactants. Vibrating sample magnetometer (VSM) test result showed Fe3O4-AOS-MN possessed superparamagnetic behavior with the saturation magnetization value of about 44.45 emu/g. The blocking temperature TB of Fe3O4-AOS-MN capped with double-layered AOS is 170 K.

  9. Comparative toxicity of selenate, selenite, seleno-DL-methionine and seleno-DL-cystine to Daphnia magna

    SciTech Connect

    Maier, K.J.; Foe, C.G.; Knight, A.W. )

    1993-04-01

    Elevated concentrations of the trace element selenium (Se) have resulted in the degradation of several aquatic ecosystems. This study evaluated the comparative toxicity of several aqueous chemical species of selenium to an aquatic cladoceran, Daphnia magna. Responses to mixtures of these selenium forms, varying the sulfate concentration, were also examined. Initial experiments compared the toxicity of aqueous forms of selenate, selenite, seleno-DL-methionine, and seleno-DL-cystine to neonate Daphnia magna, resulting in 4-h LC50 values of 2.84, 0.55, 0.31, and 2.01 mg Se per liter, respectively. Immobilization was an acute sublethal response observed during exposure to the organic selenium forms only. The 48-h IC50 values were 0.045 and 0.52 mg Se per liter for seleno-DL-methionine and seleno-DL-cystine, respectively. Evaluation of the invertebrate response to various combinations of selenate, selenite, and seleno-DL-methionine demonstrated that the toxicities of these forms of selenium are additive. Increasing the concentration of sulfate decreased, varied, and left unaffected the toxicities of selenate, selenite, and seleno-DL-methionine, respectively. These results indicate that both the chemical form of selenium and the sulfate concentration can influence the toxicity of selenium.

  10. Fullerene-like MoSe2 nanoparticles-embedded CNT balls with excellent structural stability for highly reversible sodium-ion storage

    NASA Astrophysics Data System (ADS)

    Choi, Seung Ho; Kang, Yun Chan

    2016-02-01

    Three-dimensional (3D) porous-structured carbon nanotube (CNT) balls embedded with fullerene-like MoSe2 nanocrystals were successfully prepared by the spray pyrolysis process and subsequent selenization process. The MoO2-CNT composite balls prepared by spray pyrolysis transformed into the fullerene-like MoSe2/CNT (F-MoSe2/CNT) composite balls by the selenization process. The F-MoSe2/CNT composite balls exhibited superior sodium-ion storage properties to bare MoSe2 and MoSe2/CNT with a filled structure (N-MoSe2/CNT), both of which were prepared as comparison samples. The 250th discharge capacities of bare MoSe2, N-MoSe2/CNT composite balls, and F-MoSe2/CNT composite balls were 144, 200, and 296 mA h g-1, respectively, at a high current density of 1.0 A g-1, and their capacity retentions measured from the second cycle were 37%, 66%, and 83%, respectively. The 10th discharge capacities of the F-MoSe2/CNT composite balls were 382, 346, 310, 280, and 255 mA h g-1 at current densities of 0.2, 0.5, 1.5, 3.0, and 5.0 A g-1, respectively. The synergetic effect of the fullerene-like MoSe2 nanocrystals with ultrafine sizes and the CNT balls with a tangled and 3D porous structure and high electrical conductivity resulted in excellent sodium-ion storage properties of the F-MoSe2/CNT composite balls.Three-dimensional (3D) porous-structured carbon nanotube (CNT) balls embedded with fullerene-like MoSe2 nanocrystals were successfully prepared by the spray pyrolysis process and subsequent selenization process. The MoO2-CNT composite balls prepared by spray pyrolysis transformed into the fullerene-like MoSe2/CNT (F-MoSe2/CNT) composite balls by the selenization process. The F-MoSe2/CNT composite balls exhibited superior sodium-ion storage properties to bare MoSe2 and MoSe2/CNT with a filled structure (N-MoSe2/CNT), both of which were prepared as comparison samples. The 250th discharge capacities of bare MoSe2, N-MoSe2/CNT composite balls, and F-MoSe2/CNT composite balls were 144

  11. Fullerene-like MoSe2 nanoparticles-embedded CNT balls with excellent structural stability for highly reversible sodium-ion storage.

    PubMed

    Choi, Seung Ho; Kang, Yun Chan

    2016-02-21

    Three-dimensional (3D) porous-structured carbon nanotube (CNT) balls embedded with fullerene-like MoSe2 nanocrystals were successfully prepared by the spray pyrolysis process and subsequent selenization process. The MoO2-CNT composite balls prepared by spray pyrolysis transformed into the fullerene-like MoSe2/CNT (F-MoSe2/CNT) composite balls by the selenization process. The F-MoSe2/CNT composite balls exhibited superior sodium-ion storage properties to bare MoSe2 and MoSe2/CNT with a filled structure (N-MoSe2/CNT), both of which were prepared as comparison samples. The 250(th) discharge capacities of bare MoSe2, N-MoSe2/CNT composite balls, and F-MoSe2/CNT composite balls were 144, 200, and 296 mA h g(-1), respectively, at a high current density of 1.0 A g(-1), and their capacity retentions measured from the second cycle were 37%, 66%, and 83%, respectively. The 10(th) discharge capacities of the F-MoSe2/CNT composite balls were 382, 346, 310, 280, and 255 mA h g(-1) at current densities of 0.2, 0.5, 1.5, 3.0, and 5.0 A g(-1), respectively. The synergetic effect of the fullerene-like MoSe2 nanocrystals with ultrafine sizes and the CNT balls with a tangled and 3D porous structure and high electrical conductivity resulted in excellent sodium-ion storage properties of the F-MoSe2/CNT composite balls. PMID:26830784

  12. Macroscopic and spectroscopic Characterization of Selenate, Selenite, and Chromate Adsorption at the Solid–Water Interface of -Al2O3

    SciTech Connect

    Elzinga, E.; Tang, Y; McDonald, J; DeSisto, S; Reeder, R

    2009-01-01

    The interaction of selenate, selenite, and chromate with the hydrated surface of {gamma}-Al{sub 2}O{sub 3} was studied using a combination of macroscopic pH edge data, electrophoretic mobility measurements, and X-ray absorption spectroscopic analyses. The pH edge data show generally increased oxyanion adsorption with decreasing pH, and indicate ionic strength-(in)dependent adsorption of chromate and selenate across the pH range 4-9, and ionic strength-(in)dependent adsorption of selenite in this pH range. The adsorption of chromate peaks at pH 5.0, whereas for selenate and selenite no pH adsorption maxima are observed. Electrophoretic mobility measurements show that all three oxyanions decrease the zeta potential of {gamma}-Al{sub 2}O{sub 3} upon adsorption; however, only selenite decreased the pHPZC of the {gamma}-Al{sub 2}O{sub 3} sorbent. EXAFS data indicate that selenite ions are coordinated in a bridging bidentate fashion to surface AlO6 octahedra, whereas no second-neighbor Al scattering was observed for adsorbed selenate ions. Combined, the results presented here show that pH is a major factor in determining the extent of adsorption of selenate, selenite, and chromate on hydrated {gamma}-Al{sub 2}O{sub 3}. The results point to substantial differences between these anions as to the mode of adsorption at the hydrated {gamma}-Al{sub 2}O{sub 3} surface, with selenate adsorbing as nonprotonated outer-sphere complexes, chromate forming a mixture of monoprotonated and nonprotonated outer-sphere adsorption complexes, and selenite coordinating as inner-sphere surface complexes in bridging configuration.

  13. Test Your Sodium Smarts

    MedlinePlus

    ... You may be surprised to learn how much sodium is in many foods. Sodium, including sodium chloride ... foods with little or no salt. Test your sodium smarts by answering these 10 questions about which ...

  14. Low sodium level

    MedlinePlus

    Low sodium level is a condition in which the amount of sodium (salt) in the blood is lower ... and this causes many of the symptoms of low sodium. With low sodium level (hyponatremia), the imbalance of ...

  15. Interaction of selenite with reduced Fe and/or S species: An XRD and XAS study

    NASA Astrophysics Data System (ADS)

    Finck, Nicolas; Dardenne, Kathy

    2016-05-01

    In this study, we investigated the interaction between selenite and either Fe(II)aq or S(- II)aq in solution, and the results were used to investigate the interaction between Se(IV)aq and FeS in suspension. The reaction products were characterized by a combination of methods (SEM, XRD and XAS) and the reaction mechanisms were identified. In a first experiment, Se(IV)aq was reduced to Se(0) by interaction with Fe(II)aq which was oxidized to Fe(III), but the reaction was only partial. Subsequently, some Fe(III) produced akaganeite (β-FeOOH) and the release of proton during that reaction decreased the pH. The pH decrease changed the Se speciation in solution which hindered further Se(IV) reduction by Fe(II)aq. In a second experiment, Se(IV)aq was quantitatively reduced to Se(0) by S(- II)aq and the reaction was fast. Two sulfide species were needed to reduce one Se(IV), and the observed pH increase was due to a proton consumption. For both experiments, experimental results are consistent with expectations based on the oxidation reduction potential of the various species. Upon interaction with FeS, Se(IV)aq was reduced to Se(0) and minute amounts of pyrite were detected, a consequence of partial mackinawite oxidation at surface sulfur sites. These results are of prime importance with respect to safe deep disposal of nuclear waste which contains the long-lived radionuclide 79Se. This study shows that after release of 79Se(IV) upon nuclear waste matrix corrosion, selenite can be reduced in the near field to low soluble Se(0) by interaction with Fe(II)aq and/or S(- II)aq species. Because the solubility of Se(0) species is significantly lower than that of Se(IV), selenium will become much less (bio)available and its migration out of deep HLW repositories may be drastically hindered.

  16. Interaction of selenite with reduced Fe and/or S species: An XRD and XAS study.

    PubMed

    Finck, Nicolas; Dardenne, Kathy

    2016-05-01

    In this study, we investigated the interaction between selenite and either Fe((II))aq or S((-II))aq in solution, and the results were used to investigate the interaction between Se((IV))aq and FeS in suspension. The reaction products were characterized by a combination of methods (SEM, XRD and XAS) and the reaction mechanisms were identified. In a first experiment, Se((IV))aq was reduced to Se((0)) by interaction with Fe((II))aq which was oxidized to Fe((III)), but the reaction was only partial. Subsequently, some Fe((III)) produced akaganeite (β-FeOOH) and the release of proton during that reaction decreased the pH. The pH decrease changed the Se speciation in solution which hindered further Se((IV)) reduction by Fe((II))aq. In a second experiment, Se((IV))aq was quantitatively reduced to Se((0)) by S((-II))aq and the reaction was fast. Two sulfide species were needed to reduce one Se((IV)), and the observed pH increase was due to a proton consumption. For both experiments, experimental results are consistent with expectations based on the oxidation reduction potential of the various species. Upon interaction with FeS, Se((IV))aq was reduced to Se((0)) and minute amounts of pyrite were detected, a consequence of partial mackinawite oxidation at surface sulfur sites. These results are of prime importance with respect to safe deep disposal of nuclear waste which contains the long-lived radionuclide (79)Se. This study shows that after release of (79)Se((IV)) upon nuclear waste matrix corrosion, selenite can be reduced in the near field to low soluble Se((0)) by interaction with Fe((II))aq and/or S((-II))aq species. Because the solubility of Se((0)) species is significantly lower than that of Se((IV)), selenium will become much less (bio)available and its migration out of deep HLW repositories may be drastically hindered. PMID:27010738

  17. Comparative effects of selenite and selenate on nitrate assimilation in barley seedlings

    NASA Technical Reports Server (NTRS)

    Aslam, M.; Harbit, K. B.; Huffaker, R. C.

    1990-01-01

    The effect of SeO3= and SeO4= on NO3- assimilation in 8-d-old barley (Hordeum vulgare L.) seedlings was studied over a 24-h period. Selenite at 0.1 mol m-3 in the uptake solutions severely inhibited the induction of NO3- uptake and active nitrate reductases. Selenate, at 1.0 mol m-3 in the nutrient solution, had little effect on induction of activities of these systems until after 12 h; however, when the seedlings were pretreated with 1.0 mol m-3 SeO4= for 24 h, subsequent NO3- uptake from SeO4(=) -free solutions was inhibited about 60%. Sulphate partially alleviated the inhibitory effect of SeO3= when supplied together in the ambient solutions, but had no effect in seedlings pretreated with SeO3=. By contrast, SO4= partially alleviated the inhibitory effect of SeO4= even in seedlings pretreated with SeO4=. Since uptake of NO3- by intact seedlings was also inhibited by SO3=, the percentage of the absorbed NO3- that was reduced was not affected. By contrast, SeO4=, which affected NO3- uptake much less, inhibited the percentage reduced of that absorbed. However, when supplied to detached leaves, both SeO3= and SeO4= inhibited the in vivo reduction of NO3- as well as induction of nitrate reductase and nitrite reductase activities. Selenite was more inhibitory than SeO4= ; approximately a five to 10 times higher concentration of SeO4= than SeO3= was required to achieve similar inhibition. In detached leaves, the inhibitory effect of both SeO3= and SeO4= on in vivo NO3- reduction as well as on the induction of nitrate reductase activity was partially alleviated by SO4=. The inhibitory effects of Se salts on the induction of the nitrite reductase were, however, completely alleviated by SO4=. The results show that in barley seedlings SeO3= is more toxic than SeO4=. The reduction of SeO4= to SeO3= may be a rate limiting step in causing Se toxicity.

  18. Low sodium diet (image)

    MedlinePlus

    ... for you. Look for these words on labels: low-sodium, sodium-free, no salt added, sodium-reduced, or ... for you. Look for these words on labels: low-sodium, sodium-free, no salt added, sodium-reduced, or ...

  19. Synthesis, characterization and optical properties of non-traditional tellurite-selenite glasses

    NASA Astrophysics Data System (ADS)

    Bachvarova-Nedelcheva, A.; Iordanova, R.; Kostov, K. L.; Ganev, V.; Yordanov, St.

    2014-06-01

    This study continues our investigations on non-traditional tellurite-selenite amorphous materials. Two glasses containing TeO2, SeO2, MoO3 and V2O5 were obtained at high oxygen pressure (P = 36 MPa) using pure oxides as precursors. The real bulk chemical composition of both glasses was verified by LA-ICP-MS method. The glasses were characterized by X-ray diffraction, Scanning Electron Microscopy (SEM), Differential Thermal Analysis (DTA), UV-Vis, XPS, IR and EPR spectroscopy. According to DTA the glass transition temperature (Tg) is below 300 °C. Both glasses were subjected to heat treatment (300 °C - 12 h) and as a result no crystallization was observed. The main building units (TeO3, TeO4, Mo2O8, and SеО3) were determined by IR and X-ray photoelectron spectroscopy and the existence of mixed bridging bonds only, which build up the amorphous network. It was established by UV-Vis that the obtained glasses are transparent above 550 nm and they were red colored.

  20. Effects of selenite on chlorophyll fluorescence, starch content and fatty acid in the duckweed Landoltia punctata.

    PubMed

    Zhong, Yu; Li, Yang; Cheng, Jay J

    2016-09-01

    Developing a Se-enriched feed for animal has become a considerable effort. In this study, Landoltia punctata 7449 was grown over a 12 day period under concentrations of selenite (Na2SeO3) from 0 to 80 μmol L(-1). The growth rate, the chlorophyll fluorescence, the starch content and fatty acid were measured. Se at low concentrations of ≤20 μmol L(-1) had positive effects also on growth rate, fatty acid content and yield of the L. punctata. The appropriate Se treatment enhanced the activity of the photosynthetic system by increasing Fv, Fm, Fv/Fm and Fv/Fo and decreasing Fo. However, negative impact to the L. punctata was observed when the duckweed was exposed to high Se concentrations (≥40 μmol L(-1)). Significant increases in starch content in the duckweed were observed after Se application. The present study suggests that the changes in growth rate, the photosynthetic system, the starch content and the fatty acid were closely associated with the application of Se. An increased Se concentration (0-20 μmol L(-1)) in duckweed could positively induce photosynthesis, thereby increasing the yield of L. punctata and could be a resource for high nutritive quality Se-enrich feed. PMID:27400684

  1. X-ray standing wave investigation of the surface structure of selenite anions adsorbed on calcite.

    SciTech Connect

    Cheng, L.; Lyman, P. F.; Sturchio, N. C.; Bedzyk, M. J.; Northwestern Univ.

    1997-01-01

    The adsorption of selenite ions (SeO{sup 2-}{sub 3}) from a dilute aqueous solution onto a freshly-cleaved calcite (10 {ovr 1} 4) surface was studied with the X-ray standing wave (XSW) technique. The complex ion SeO{sup 2-}{sub 3} is found to selectively adsorb at the CO{sup 2-}{sub 3} site via ionic exchange, forming a two-dimensional solid-solution of the form Ca(SeO{sub 3}){sub x}(CO{sub 3}){sub 1-x} at the interface. The calcite (10 {ovr 1} 4), (0006) and (11 {ovr 2} 0) Bragg reflections were used to triangulate the Se position with respect to the calcite lattice. The local surface structure at the SeO{sup 2-}{sub 3} adsorbate site, derived from the XSW results, is consistent with a model in which the base of the SeO{sup 2-}{sub 3} trigonal pyramid aligns with (and replaces) the CO{sup 2-}{sub 3} equilateral triangular group. The SeO{sup 2-}{sub 3} adsorption saturated at a coverage of 0.02 monolayers. Under identical chemical conditions, selenate (SeO{sup 2-}{sub 4}) adsorption was inhibited.

  2. Selenate and Selenite Reduction by Nanometer-Scale Zerovalent Iron Particles

    NASA Astrophysics Data System (ADS)

    Olegario, J. T.; Yee, N. Y.; Manning, B. A.

    2007-12-01

    Selenium oxyanions can be present in agricultural drainage waters, coal mining effluent, and as fission products in radioactive wastes. The objective of this work was to evaluate the effectiveness of both nanometer scale zerovalent iron (nano-Fe) and 100 mesh Fe filings for reduction and immobilization of aqueous selenate Se(VI) and selenite Se(IV). The uptake of Se(VI) and Se(IV) using batch equilibrium, kinetics, and X-ray absorption spectroscopic (XAS) techniques was investigated. In addition, a thorough investigation of the solid phase corrosion products by X-ray diffraction was conducted. The crystalline corrosion product was similar to magnetite, though some distinct differences in the XRD results were noted between Se(IV)- and Se(VI)-treated samples. Application of quantitative X-ray absorption near edge spectroscopy (XANES) revealed that both Se(VI) and Se(IV) were reduced to a mixture of elemental Se(0) plus iron(II) selenide (Se(-II)). The Se local atomic structure in Se(VI)- and Se(IV)-treated nano-Fe was determined using extended x-ray absorption fine structure spectroscopy (EXAFS) and a Se-Se interatomic distance of 2.44 angstroms was revealed. This work suggests that nano-Fe is an efficient material for removing dissolved Se(VI) and Se(IV) from waste waters by formation of an insoluble, reduced FeSe product.

  3. Effect of selenite on the morphology and respiratory activity of Phanerochaete chrysosporium biofilms.

    PubMed

    Espinosa-Ortiz, Erika J; Pechaud, Yoan; Lauchnor, Ellen; Rene, Eldon R; Gerlach, Robin; Peyton, Brent M; van Hullebusch, Eric D; Lens, Piet N L

    2016-06-01

    The temporal and spatial effects of selenite (SeO3(2-)) on the physical properties and respiratory activity of Phanerochaete chrysosporium biofilms, grown in flow-cell reactors, were investigated using oxygen microsensors and confocal laser scanning microscopy (CLSM) imaging. Exposure of the biofilm to a SeO3(2-) load of 1.67mgSeL(-1)h(-1) (10mgSeL(-1) influent concentration), for 24h, resulted in a 20% reduction of the O2 flux, followed by a ∼10% decrease in the glucose consumption rate. Long-term exposure (4days) to SeO3(2-) influenced the architecture of the biofilm by creating a more compact and dense hyphal arrangement resulting in a decrease of biofilm thickness compared to fungal biofilms grown without SeO3(2-). To the best of our knowledge, this is the first time that the effect of SeO3(2-) on the aerobic respiratory activity on fungal biofilms is described. PMID:26935326

  4. Selenite Enhances Immune Response against Pseudomonas aeruginosa PA14 via SKN-1 in Caenorhabditis elegans

    PubMed Central

    Huang, Chi-Wei; Wei, Chia-Cheng; Liao, Vivian Hsiu-Chuan

    2014-01-01

    Background Selenium (Se) is an important nutrient that carries out many biological processes including maintaining optimal immune function. Here, inorganic selenite (Se(IV)) was evaluated for its pathogen resistance and potential-associated factors in Caenorhabditis elegans. The immune effects of Se(IV) were investigated by examining the responses of C. elegans to Pseudomonas aerugonisa PA14 strain. Principal Findings Se(IV)-treated C. elegans showed increased survival under PA14 infection compared with untreated controls. The significant pathogen resistance of Se(IV) on C. elegans might not be attributed to the effects of Se(IV) on PA14 as Se(IV) showed no effect on bacterial quorum-sensing and virulence factors of PA14. This study showed that Se(IV) enhanced the expression of a gene pivotal for the innate immunity in C. elegans. The study found that the pathogen-resistant phenotypes contributed by Se(IV) was absent from the skn-1 mutant worms. Moreover, Se(IV) influenced the subcellular distribution of SKN-1/Nrf in C. elegans upon PA14 infection. Furthermore, Se(IV) increased mRNA levels of SKN-1 target genes (gst-4 and gcs-1). Conclusions This study found evidence of Se(IV) protecting C. elegans against P. aeruginosa PA14 infection by exerting effects on the innate immunity of C. elegans that is likely mediated via regulation of a SKN-1-dependent signaling pathway. PMID:25147937

  5. An evaluation of strontium chloride, Rappaport and strontium selenite enrichment for the isolation of salmonellas from man, animals, meat products and abattoir effluents.

    PubMed

    Iveson, J B; Mackay-Scollay, E M

    1972-06-01

    Strontium chloride enrichment broth was found to be comparable to Rappaport broth for the recovery of a wide range of Salmonella serotypes from man, animals, meat products and effluents. With the exception of cloacal samples from reptiles, both procedures were superior to selenite F.The performance of strontium chloride Mand selenite F enrichment was improved when effluent samples were incubated at 43 degrees C.Strontium chloride M and Rappaport enrichment were superior to selenite F for the isolation of Arizona species from reptiles.Strontium chloride B, strontium selenite and Rappaport broths were found suitable for the isolation of multiple Salmonella serotypes from sea water contaminated with abattoir effluents. The strontium chloride B and strontium selenite enrichment media were superior to Rappaport broth when samples were incubated at 43 degrees C.Modified bismuth sulphite agar was found superior to Salmonella-Shigella agar as a solid subculture medium.The investigation of a food poisoning outbreak due to Salmonella typhimurium phage type 21 is reported.The significance of the choice of sampling and isolation techniques in salmonellosis in man and animals is discussed. PMID:4503874

  6. Selenium nanoparticles incorporated into titania nanotubes inhibit bacterial growth and macrophage proliferation.

    PubMed

    Liu, Wenwen; Golshan, Negar H; Deng, Xuliang; Hickey, Daniel J; Zeimer, Katherine; Li, Hongyi; Webster, Thomas J

    2016-08-25

    Since implants often fail due to infection and uncontrolled inflammatory responses, we designed an in vitro study to investigate the antibacterial and anti-inflammatory properties of titanium dioxide nanotubes (TNTs) incorporated with selenium nanoparticles (SeNPs). Selenium incorporation was achieved by the reaction of sodium selenite (Na2SeO3) with glutathione (GSH) under a vacuum in the presence of TNTs. Two types of bacteria and macrophages were cultured on the samples to determine their respective antibacterial and anti-inflammatory properties. The results showed that the TNT samples incorporating SeNPs (TNT-Se) inhibited the growth of Escherichia coli and Staphylococcus aureus compared to unmodified TNTs, albeit the SeNP concentration still needs to be optimized for maximal effect. At their maximum effect, the TNT-Se samples reduced the density of E. coli by 94.6% and of S. aureus by 89.6% compared to titanium controls. To investigate the underlying mechanism of this effect, the expression of six E. coli genes were tracked using qRT-PCR. Results indicated that SeNPs weakened E. coli membranes (ompA and ompF were down-regulated), decreased the function of adhesion-mediating proteins (csgA and csgG were progressively down-regulated with increasing SeNP content), and induced the production of damaging reactive oxygen species (ahpF was up-regulated). Moreover, TNT-Se samples inhibited the proliferation of macrophages, indicating that they can be used to control the inflammatory response and even prevent chronic inflammation, a condition that often leads to implant failure. In conclusion, we demonstrated that SeNP-TNTs display antibacterial and anti-inflammatory properties that are promising for improving the performance of titanium-based implants for numerous orthopedic and dental applications. PMID:27533297

  7. Synthesis and phase transition under ultra-high pressure of ZnS nanoparticles modified by sodium bis(2-ethylhexyl) sulfosuccinate

    NASA Astrophysics Data System (ADS)

    Ji, Yunliang; Guo, Lin; Xu, Huibin; Liu, Jing; Li, Xiaodong; Li, Yanchun; Wu, Ziyu; Simon, Paul

    2003-07-01

    ZnS nanoparticles modified by AOT with different particle sizes (5 nm and 13 nm) were prepared in reverse micelles. The products show the zinc-blende (B3) structure at atmospheric pressure, and the B3 structure was proved to exist at smaller size dimensions than the B4 structure. The pressure-induced phase transition to the rock salt (B1) phase was studied by in situ high-pressure energy-dispersive X-ray diffraction experiments. The transition began at a pressure of around 15.4 GPa for the 5 nm sample and at 16 GPa for the 13 nm sample. It is indicated that the transition pressure is not obviously dependent on the grain size of the nano-crystals in our experiments. From the small transition pressure gap between the two different sizes it can be deduced that the transition pressure goes to the same value below a certain particle size. This feature could be caused by the crystal lattice contraction due to the strong surface pressure. Our results imply, that the new high-pressure phase is metastable and cannot exist in ordinary circumstances.

  8. Genome sequence of the anaerobic bacterium Bacillus sp. strain ZYK, a selenite and nitrate reducer from paddy soil.

    PubMed

    Bao, Peng; Su, Jian-Qiang; Hu, Zheng-Yi; Häggblom, Max M; Zhu, Yong-Guan

    2014-06-15

    Bacillus sp. strain ZYK, a member of the phylum Firmicutes, is of interest for its ability to reduce nitrate and selenite and for its resistance to arsenic under anaerobic conditions. Here we describe some key features of this organism, together with the complete genome sequence and annotation. The 3,575,797 bp long chromosome with its 3,454 protein-coding and 70 RNA genes, and the information gained from its sequence will be relevant to the elucidation of microbially-mediated transformations of nitrogen, selenium and arsenic in paddy soil. PMID:25197451

  9. Genome sequence of the anaerobic bacterium Bacillus sp. strain ZYK, a selenite and nitrate reducer from paddy soil

    PubMed Central

    Bao, Peng; Su, Jian-Qiang; Hu, Zheng-Yi; Häggblom, Max M.

    2014-01-01

    Bacillus sp. strain ZYK, a member of the phylum Firmicutes, is of interest for its ability to reduce nitrate and selenite and for its resistance to arsenic under anaerobic conditions. Here we describe some key features of this organism, together with the complete genome sequence and annotation. The 3,575,797 bp long chromosome with its 3,454 protein-coding and 70 RNA genes, and the information gained from its sequence will be relevant to the elucidation of microbially-mediated transformations of nitrogen, selenium and arsenic in paddy soil. PMID:25197451

  10. Mixed Hemi/Ad-Micelle Sodium Dodecyl Sulfate-Coated Magnetic Iron Oxide Nanoparticles for the Efficient Removal and Trace Determination of Rhodamine-B and Rhodamine-6G.

    PubMed

    Ranjbari, Elias; Hadjmohammadi, Mohammad Reza; Kiekens, Filip; De Wael, Karolien

    2015-08-01

    Mixed hemi/ad-micelle sodium dodecyl sulfate (SDS)-coated magnetic iron oxide nanoparticles (MHAMS-MIONPs) were used as an efficient adsorbent for both removal and preconcentration of two important carcinogenic xanthine dyes named rhodamine-B (RB) and rhodamine-6G (RG). To gain insight in the configuration of SDS molecules on the surface of MIONPs, zeta potential measurements were performed in different [SDS]/[MIONP] ratios. Zeta potential data indicated that mixed hemi/ad-micelle MHAM was formed in [SDS]/[MIONP] ratios over the range of 1.1 to 7.3. Parameters affecting the adsorption of dyes were optimized as removal efficiency by one variable at-a-time and response surface methodology; the obtained removal efficiencies were ∼100%. Adsorption kinetic and equilibrium studies, under the optimum condition (pH = 2; amount of MIONPs = 87.15 mg; [SDS]/[MIONP] ratio = 2.9), showed that adsorption of both dyes are based on the pseudo-second-order and the Langmuir isotherm models, respectively. The maximum adsorption capacities for RB and RG were 385 and 323 mg g(-1), respectively. MHAMS-MIONPs were also applied for extraction of RB and RG. Under optimum conditions (pH = 2; amount of damped MHAMS-MIONPs = 90 mg; eluent solvent volume = 2.6 mL of 3% acetic acid in acetonitrile), extraction recoveries for 0.5 mg L(-1) of RB and RG were 98% and 99%, with preconcentration factors of 327 and 330, respectively. Limit of detection obtained for rhodamine dyes were <0.7 ng mL(-1). Finally, MHAMS-MIONPs were successfully applied for both removal and trace determination of RB and RG in environmental and wastewater samples. PMID:26154872

  11. Syntheses and structures of three f-element selenite/hydroselenite compounds

    SciTech Connect

    Burns, Wendy L.; Ibers, James A.

    2009-06-15

    The selenite/hydroselenite compounds Ce(SeO{sub 3})(HSeO{sub 3}), Tb(SeO{sub 3})(HSeO{sub 3}).2H{sub 2}O, and Cs[U(SeO{sub 3})(HSeO{sub 3})].3H{sub 2}O were synthesized by hydrothermal means at 453 K from the reaction of CeO{sub 2} or Tb{sub 4}O{sub 7} or UO{sub 2} with SeO{sub 2} and CsCl (as a mineralizer). Ce(SeO{sub 3})(HSeO{sub 3}) crystallizes in the non-centrosymmetric orthorhombic space group Pca2{sub 1}. The structure comprises a two-dimensional network of interconnected CeO{sub 10} bicapped distorted square antiprisms and SeO{sub 3} trigonal pyramids. Tb(SeO{sub 3})(HSeO{sub 3}).2H{sub 2}O crystallizes in the non-centrosymmetric orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}. The structure features a two-dimensional layer of interconnected TbO{sub 8} distorted square antiprisms and SeO{sub 3} trigonal pyramids. Cs[U(SeO{sub 3})(HSeO{sub 3})].3H{sub 2}O crystallizes in the centrosymmetric monoclinic space group P2{sub 1}/n. The structure consists of two-dimensional layers of interconnected UO{sub 7} pentagonal bipyramids and SeO{sub 3} trigonal pyramids. The layers in all three structures are held together by hydrogen-bonding networks. - Graphical abstract: Structure of Ce[U(SeO{sub 3})(HSeO{sub 3})].3H{sub 2}O (Cs, purple; U, black; Se, blue; O, red; O{sub w}, green; H, gray).

  12. Field study of time-dependent selenium partitioning in soils using isotopically enriched stable selenite tracer.

    PubMed

    Di Tullo, Pamela; Pannier, Florence; Thiry, Yves; Le Hécho, Isabelle; Bueno, Maïté

    2016-08-15

    A better understanding of selenium fate in soils at both short and long time scales is mandatory to consolidate risk assessment models relevant for managing both contamination and soil fertilization issues. The purpose of this study was thus to investigate Se retention processes and their kinetics by monitoring time-dependent distribution/speciation changes of both ambient and freshly added Se, in the form of stable enriched selenite-77, over a 2-years field experiment. This study clearly illustrates the complex reactivity of selenium in soil considering three methodologically defined fractions (i.e. soluble, exchangeable, organic). Time-dependent redistribution of Se-77 within solid-phases having different reactivity could be described as a combination of chemical and diffusion controlled processes leading to its stronger retention. Experimental data and their kinetic modeling evidenced that transfer towards less labile bearing phases are controlled by slow processes limiting the overall sorption of Se in soils. These results were used to estimate time needed for (77)Se to reach the distribution of naturally present selenium which may extend up to several decades. Ambient Se speciation accounted for 60% to 100% of unidentified species as function of soil type whereas (77)Se(IV) remained the more abundant species after 2-years field experiment. Modeling Se in the long-term without taking account these slow sorption kinetics would thus result in underestimation of Se retention. When using models based on Kd distribution coefficient, they should be at least reliant on ambient Se which is supposed to be at equilibrium. PMID:27100008

  13. Low sodium level

    MedlinePlus

    Low sodium level is a condition in which the amount of sodium (salt) in the blood is lower than normal. The ... Sodium is found mostly in the body fluids outside the cells. It is very important for maintaining ...

  14. Molecular Structures of Al/Si and Fe/Si Coprecipitates and the Implication for Selenite Removal

    PubMed Central

    Chan, Ya-Ting; Kuan, Wen-Hui; Tzou, Yu-Min; Chen, Tsan-Yao; Liu, Yu-Ting; Wang, Ming-Kuang; Teah, Heng-Yi

    2016-01-01

    Aluminum and iron oxides have been often used in the coagulation processes during water purification due to their unique surface properties toward anions. In the presence of silica, the coprecipitation of Al/Si or Fe/Si might decrease the efficiency of wastewater purification and reuse. In this study, surface properties and molecular structures of Al/Si and Fe/Si coprecipitates were characterized using spectroscopic techniques. Also, the selenite removal efficiency of Al/Si and Fe/Si coprecipitates in relation to their surface and structural properties was investigated. While dissolved silicate increased with increasing pH from Fe/Si coprecipitates, less than 7% of silicate was discernible from Al/Si samples over the range from acidic to alkaline conditions. Our spectroscopic results showed that the associations between Al and Si were relatively stronger than that between Fe and Si in coprecipitates. In Al/Si coprecipitates, core-shell structures were developed with AlO6/AlO4 domains as the shells and Si frameworks polymerized from the SiO2 as the cores. However, Si framework remained relatively unchanged upon coprecipitation with Fe hydroxides in Fe/Si samples. The Si core with Al shell structure of Al/Si coprecipitates shielded the negative charges from SiO2 and thereby resulted in a higher adsorption capacity of selenite than Fe/Si coprecipitates. PMID:27095071

  15. Molecular Structures of Al/Si and Fe/Si Coprecipitates and the Implication for Selenite Removal

    NASA Astrophysics Data System (ADS)

    Chan, Ya-Ting; Kuan, Wen-Hui; Tzou, Yu-Min; Chen, Tsan-Yao; Liu, Yu-Ting; Wang, Ming-Kuang; Teah, Heng-Yi

    2016-04-01

    Aluminum and iron oxides have been often used in the coagulation processes during water purification due to their unique surface properties toward anions. In the presence of silica, the coprecipitation of Al/Si or Fe/Si might decrease the efficiency of wastewater purification and reuse. In this study, surface properties and molecular structures of Al/Si and Fe/Si coprecipitates were characterized using spectroscopic techniques. Also, the selenite removal efficiency of Al/Si and Fe/Si coprecipitates in relation to their surface and structural properties was investigated. While dissolved silicate increased with increasing pH from Fe/Si coprecipitates, less than 7% of silicate was discernible from Al/Si samples over the range from acidic to alkaline conditions. Our spectroscopic results showed that the associations between Al and Si were relatively stronger than that between Fe and Si in coprecipitates. In Al/Si coprecipitates, core-shell structures were developed with AlO6/AlO4 domains as the shells and Si frameworks polymerized from the SiO2 as the cores. However, Si framework remained relatively unchanged upon coprecipitation with Fe hydroxides in Fe/Si samples. The Si core with Al shell structure of Al/Si coprecipitates shielded the negative charges from SiO2 and thereby resulted in a higher adsorption capacity of selenite than Fe/Si coprecipitates.

  16. Molecular Structures of Al/Si and Fe/Si Coprecipitates and the Implication for Selenite Removal.

    PubMed

    Chan, Ya-Ting; Kuan, Wen-Hui; Tzou, Yu-Min; Chen, Tsan-Yao; Liu, Yu-Ting; Wang, Ming-Kuang; Teah, Heng-Yi

    2016-01-01

    Aluminum and iron oxides have been often used in the coagulation processes during water purification due to their unique surface properties toward anions. In the presence of silica, the coprecipitation of Al/Si or Fe/Si might decrease the efficiency of wastewater purification and reuse. In this study, surface properties and molecular structures of Al/Si and Fe/Si coprecipitates were characterized using spectroscopic techniques. Also, the selenite removal efficiency of Al/Si and Fe/Si coprecipitates in relation to their surface and structural properties was investigated. While dissolved silicate increased with increasing pH from Fe/Si coprecipitates, less than 7% of silicate was discernible from Al/Si samples over the range from acidic to alkaline conditions. Our spectroscopic results showed that the associations between Al and Si were relatively stronger than that between Fe and Si in coprecipitates. In Al/Si coprecipitates, core-shell structures were developed with AlO6/AlO4 domains as the shells and Si frameworks polymerized from the SiO2 as the cores. However, Si framework remained relatively unchanged upon coprecipitation with Fe hydroxides in Fe/Si samples. The Si core with Al shell structure of Al/Si coprecipitates shielded the negative charges from SiO2 and thereby resulted in a higher adsorption capacity of selenite than Fe/Si coprecipitates. PMID:27095071

  17. Thermodynamics of arsenates, selenites, and sulfates in the oxidation zone of sulfide ores: I. Thermodynamic constants at ambient conditions

    NASA Astrophysics Data System (ADS)

    Charykova, M. V.; Krivovichev, V. G.; Depmeir, W.

    2010-12-01

    Understanding and deciphering processes proceeding near the surface are among the urgent tasks of contemporary mineralogy and geochemistry, which are especially important for resolving ecological challenges and developing principles of rational environmental management. The paper presents systematized data published on thermodynamics of minerals (arsenates, sulfates, selenites, and selenates), which are formed in the weathering zone of sulfide ores, and determines approaches to quantitative physicochemical modeling of their formation conditions. Diagrams of phase and chemical equilibria (Eh-pH, diagrams of solubility) of the subsystems of the model system Fe-Cu-Zn-Pb-Co-Ni-As-Se-S-H2O (Fe2+, Fe3+, Cu2+, Zn2+, Pb2+, Ni2+, Co2+, H+//SeO{3/2-}, SeO{4/2-}, AsO{4/3-}, SO{4/2-}, OH--H2O) are used as a thermodynamic basis for modeling mineral-forming processes in the weathering zone of ore deposits. Seventy-two arsenates, about 70 sulfates, and 7 selenites and selenates have been identified in the framework of this system. The available published values of standard thermodynamic functions of the formation of minerals and chemical compounds are given, as well as the Pitzer equation parameters to describe the sulfate systems, which are substantially specific due to the high solubility of their components.

  18. The Role of Elevated PCO2 on Selenate and Selenite Sorption to and Desorption from Calcareous Soils and Carbonate Minerals

    NASA Astrophysics Data System (ADS)

    Jacobson, A. R.; Wen, L.

    2013-12-01

    Selenium is a minor component of highly weatherable rock formations in the Uintah Basin Utah from which soils are formed. Activities such as soil/gas extraction and irrigated agriculture may be accelerating the mobilization of Se in the soils, which eventually reach the Pariette Wetlands. Since the wetlands are a stopping point for migratory water fowl, the elevated levels of Se detected in the sediments and waters are of concern. Understanding soil mechanisms related to selenium transport through soils is critical to managing the contamination. In microbially active agricultural soils concentrations of CO2 in the soil air may be 10 to 100 times higher than at the soil surface. CO2 dissolved in the soil solution forms numerous carbonate species that may enhance or compete with selenate and selenite sorption/desorption from soil. Thus we investigated the partitioning of Se between the immobile solid phase and mobile solution phase in six calcareous soils and three carbonate minerals by the batch sorption method at ambient and elevated PCO2. We hypothesized that in these highly buffered soils competition from carbonate species would result in decreased Se sorption. Results indicate that at elevated PCO2 selenate and selenite sorption increased in all soils and minerals tested relative to sorption at ambient levels. Minimal desorption occurred with a dilute electrolyte solution, but could be induced in the presence of phosphate. This finding suggests that actively respiring soils mitigate Se transport to ground or surface waters.

  19. Comparison of selenite F, Muller-Kauffmann tetrathionate and Rappaport's medium for salmonella isolation from chicken giblets after pre-enrichment in buffered peptone water.

    PubMed Central

    Harvey, R. W.; Price, T. H.

    1981-01-01

    Six hundred and eighty three samples of chicken giblets were examined for salmonellas. Three hundred and forty nine of these were neck and crop specimens and 224 were combined liver and heart samples. Two hundred and ten, in all, contained salmonellas. The technique of examination included pre-enrichment in buffered peptone water at 37 degrees C for 18 h and subculture to three enrichment media: Muller-Kauffmann tetrathionate, selenite F and Rappaport's magnesium chloride malachite green broth. Inocula from buffered peptone water to 10 ml of tetrathionate and selenite were 1 ml in each case. The inoculum from the pre-enrichment medium to 10 ml of Rappaport was 0.005 ml. Tetrathionate and selenite were incubated at 43 degrees C for 48 h. Rappaport's medium was incubated at 37 degrees C for 48 h. Subcultures from all three enrichment broths were made at 24 h and 48 h to brilliant green MacConkey agar. Selective agars were incubated at 37 degrees C for 24 h. The most successful technique for salmonella isolation used Rappaport's medium, which was significantly more efficient than either tetrathionate or selenite. This finding reinforces results obtained using sewage polluted natural water as test material and it is suggested that routine examination of environment samples for salmonellas could be based on Rappaport's medium alone. If S. typhi, S. dublin or subgenus III salmonellas were likely to be present in the sample, the technique described here would require modification. PMID:7026671

  20. Cerebral Area Differential Redox Response of Neonatal Rats to Selenite-Induced Oxidative Stress and to Concurrent Administration of Highbush Blueberry Leaf Polyphenols.

    PubMed

    Ferlemi, Anastasia-Varvara; Mermigki, Penelope G; Makri, Olga E; Anagnostopoulos, Dimitrios; Koulakiotis, Nikolaos S; Margarity, Marigoula; Tsarbopoulos, Anthony; Georgakopoulos, Constantinos D; Lamari, Fotini N

    2015-11-01

    Our goal was to delineate the mechanisms of selenite-induced oxidative stress in neonatal rats and investigate the potential of blueberry leaf polyphenols to counteract the induced stress. Vaccinium corymbosum leaf decoction (BLD) was analyzed by UPLC-MS and LC-DAD, along with its in vitro antioxidant activity (DPPH radical scavenging, FRAP, ferrous chelation). Newborn suckling Wistar rats were randomly divided into three groups: 'Se' and 'SeBLD' received 20 μmol Na2SeO3/kg BW subcutaneously (PN day 10); 'SeBLD' received 100 mg dry BLD/kg BW intraperitoneally (PN11 and 12) and Group 'C' received normal saline. Βiochemical analysis revealed tissue-specific effects of selenite. Brain as a whole was more resistant to selenite toxicity in comparison to liver; midbrain and cerebellum were in general not affected, but cortex was moderately disturbed. Liver lipid peroxidation, GSH, SOD, CAT, GPx were significantly affected, whereas proteolytic activity was not. BLD, which is rich in chlorogenic acid and flavonols (especially quercetin derivatives), exerted significant antioxidant protective effects in all regions. In conclusion, we provide for the first time an insight to the neonatal rat cerebral and liver redox response against a toxic selenite dose and blueberry leaf polyphenols. PMID:26357951

  1. Draft Genome Sequence of "Halomonas chromatireducens" Strain AGD 8-3, a Haloalkaliphilic Chromate- and Selenite-Reducing Gammaproteobacterium.

    PubMed

    Sharko, Fedor S; Shapovalova, Anna A; Tsygankova, Svetlana V; Komova, Anastasia V; Boulygina, Eugenia S; Teslyuk, Anton B; Gotovtsev, Pavel M; Namsaraev, Zorigto B; Khijniak, Tatiana V; Nedoluzhko, Artem V; Vasilov, Raif G

    2016-01-01

    Here, we report the complete genome sequence (3.97 Mb) of "Halomonas chromatireducens" AGD 8-3, a denitrifying bacterium capable of chromate and selenite reduction under extreme haloalkaline conditions. This strain was isolated from soda solonchak soils of the Kulunda steppe, Russian Federation. PMID:26988058

  2. Draft Genome Sequence of “Halomonas chromatireducens” Strain AGD 8-3, a Haloalkaliphilic Chromate- and Selenite-Reducing Gammaproteobacterium

    PubMed Central

    Sharko, Fedor S.; Shapovalova, Anna A.; Tsygankova, Svetlana V.; Komova, Anastasia V.; Boulygina, Eugenia S.; Teslyuk, Anton B.; Gotovtsev, Pavel M.; Namsaraev, Zorigto B.; Khijniak, Tatiana V.; Vasilov, Raif G.

    2016-01-01

    Here, we report the complete genome sequence (3.97 Mb) of “Halomonas chromatireducens” AGD 8-3, a denitrifying bacterium capable of chromate and selenite reduction under extreme haloalkaline conditions. This strain was isolated from soda solonchak soils of the Kulunda steppe, Russian Federation. PMID:26988058

  3. Diclofenac sodium.

    PubMed

    Small, R E

    1989-08-01

    The pharmacology, pharmacokinetics, clinical efficacy, adverse effects, and dosage of diclofenac sodium are reviewed. Diclofenac, the first nonsteroidal anti-inflammatory agent (NSAID) to be approved that is a phenylacetic acid derivative, competes with arachidonic acid for binding to cyclo-oxygenase, resulting in decreased formation of prostaglandins. The drug has both analgesic and antipyretic activities. Diclofenac is efficiently absorbed from the gastrointestinal tract; peak plasma concentrations occur 1.5 to 2.0 hours after ingestion in fasting subjects. Even though diclofenac has a relatively short elimination half-life in plasma (1.5 hours), it persists in synovial fluid. The drug is metabolized in the liver and is eliminated by urinary and biliary excretion. In clinical trials, diclofenac was as effective as aspirin, diflunisal, indomethacin, sulindac, ibuprofen, ketoprofen, and naproxen in improving function and reducing pain in patients with rheumatoid arthritis. For treatment of osteoarthritis, diclofenac was equivalent in efficacy to aspirin, diflunisal, indomethacin, sulindac, ibuprofen, ketoprofen, naproxen, flurbiprofen, mefenamic acid, and piroxicam. Diclofenac was as effective as indomethacin or sulindac in treating ankylosing spondylitis. The most frequent adverse effects reported for diclofenac were gastrointestinal, but these effects were fewer and less serious than occurred with aspirin or indomethacin; in addition, diclofenac caused fewer central nervous system reactions than indomethacin. Diclofenac is administered in divided doses with meals. The recommended total daily dosage is 100 to 150 mg (osteoarthritis and ankylosing spondylitis) or 150 to 200 mg (rheumatoid arthritis). Diclofenac is effective, but no more so than other NSAIDs. It is structurally distinct and offers another choice in the treatment of rheumatological conditions. PMID:2670397

  4. Sodium blood test

    MedlinePlus

    ... foods. The most common form of sodium is sodium chloride, which is table salt. This test is usually done as part of an electrolyte or basic metabolic panel blood test . Your blood sodium level represents a balance between the sodium and ...

  5. Controlling the self-assembly of a mixed-metal Mo/V-selenite family of polyoxometalates.

    PubMed

    Corella-Ochoa, M Nieves; Miras, Haralampos N; Long, De-Liang; Cronin, Leroy

    2012-10-22

    Five mixed-metal mixed-valence Mo/V polyoxoanions, templated by the pyramidal SeO(3)(2-) heteroanion have been isolated: K(10)[Mo(VI)(12)V(V)(10)O(58)(SeO(3))(8)]⋅18 H(2)O (1), K(7)[Mo(VI)(11)V(V)(5)V(IV)(2)O(52)(SeO(3))]⋅31 H(2)O (2), (NH(4))(7)K(3)[Mo(VI)(11)V(V)(5)V(IV)(2)O(52)(SeO(3))(Mo(V)(6)V(V)-O(22))]⋅40 H(2)O (3), (NH(4))(19)K(3)[Mo(VI)(20)V(V)(12)V(IV)(4)O(99)(SeO(3))(10)]⋅36 H(2)O (4) and [Na(3)(H(2)O)(5){Mo(18-x)V(x)O(52)(SeO(3))} {Mo(9-y)V(y)O(24)(SeO(3))(4)}] (5). All five compounds were characterised by single-crystal X-ray structure analysis, TGA, UV/Vis and FT-IR spectroscopy, redox titrations, and elemental and flame atomic absorption spectroscopy (FAAS) analysis. X-ray studies revealed two novel coordination modes for the selenite anion in compounds 1 and 4 showing η,μ and μ,μ coordination motifs. Compounds 1 and 2 were characterised in solution by using high-resolution ESI-MS. The ESI-MS spectra of these compounds revealed characteristic patterns showing distribution envelopes corresponding to 2- and 3- anionic charge states. Also, the isolation of these compounds shows that it may be possible to direct the self-assembly process of the mixed-metal systems by controlling the interplay between the cation "shrink-wrapping" effect, the non-conventional geometry of the selenite anion and fine adjustment of the experimental variables. Also a detailed IR spectroscopic analysis unveiled a simple way to identify the type of coordination mode of the selenite anions present in POM-based architectures. PMID:22996730

  6. Plants and microbes assisted selenium nanoparticles: characterization and application

    PubMed Central

    2014-01-01

    Selenium is an essential trace element and is an essential component of many enzymes without which they become inactive. The Se nanoparticles of varying shape and size may be synthesized from Se salts especially selenite and selenates in presence of reducing agents such as proteins, phenols, alcohols and amines. These biomolecules can be used to reduce Se salts in vitro but the byproducts released in the environment may be hazardous to flora and fauna. In this review, therefore, we analysed in depth, the biogenic synthesis of Se nanoparticles, their characterization and transformation into t- Se, m-Se, Se-nanoballs, Se-nanowires and Se-hollow spheres in an innocuous way preventing the environment from pollution. Their shape, size, FTIR, UV–vis, Raman spectra, SEM, TEM images and XRD pattern have been analysed. The weak forces involved in aggregation and transformation of one nano structure into the other have been carefully resolved. PMID:25128031

  7. Plants and microbes assisted selenium nanoparticles: characterization and application.

    PubMed

    Husen, Azamal; Siddiqi, Khwaja Salahuddin

    2014-01-01

    Selenium is an essential trace element and is an essential component of many enzymes without which they become inactive. The Se nanoparticles of varying shape and size may be synthesized from Se salts especially selenite and selenates in presence of reducing agents such as proteins, phenols, alcohols and amines. These biomolecules can be used to reduce Se salts in vitro but the byproducts released in the environment may be hazardous to flora and fauna. In this review, therefore, we analysed in depth, the biogenic synthesis of Se nanoparticles, their characterization and transformation into t- Se, m-Se, Se-nanoballs, Se-nanowires and Se-hollow spheres in an innocuous way preventing the environment from pollution. Their shape, size, FTIR, UV-vis, Raman spectra, SEM, TEM images and XRD pattern have been analysed. The weak forces involved in aggregation and transformation of one nano structure into the other have been carefully resolved. PMID:25128031

  8. Broadband conductivity spectra of fast-ion-conducting silver selenite glasses: Dependence on power law and scaling

    NASA Astrophysics Data System (ADS)

    Deb, B.; Bhattacharya, S.; Ghosh, A.

    2011-11-01

    In this letter we have studied broadband conductivity spectra (10 Hz-3 GHz) of fast-ion-conducting silver selenite glasses of compositions xAgI-(1-x)(yAg2O-(1-y)SeO2). We have observed that the conductivity spectra below 10 MHz are characterized by a power law with exponent less than unity, while the conductivity spectra in the high-frequency range (above 10 MHz) have been adequately explained in the framework of the unified site relaxation model with exponent greater than unity. The scaling of the conductivity spectra indicates that the time-temperature superposition principle is valid in the low-frequency regime, but not in the high-frequency regime.

  9. Cerebrospinal fluid of newly diagnosed amyotrophic lateral sclerosis patients exhibits abnormal levels of selenium species including elevated selenite

    PubMed Central

    Vinceti, Marco; Solovyev, Nikolay; Mandrioli, Jessica; Crespi, Catherine M.; Bonvicini, Francesca; Arcolin, Elisa; Georgoulopoulou, Eleni; Michalke, Bernhard

    2013-01-01

    Exposure to selenium, and particularly to its inorganic forms, has been hypothesized as a risk factor for amyotrophic lateral sclerosis (ALS), a fast progressing motor neuron disease with poorly understood etiology. However, no information is known about levels of inorganic and some organic selenium species in the central nervous system of ALS patients, and recent observations suggest that peripheral biomarkers of exposure are unable to predict these levels for several Se species including the inorganic forms. Using a hospital-referred cases-control series and advanced selenium speciation methods, we compared the chemical species of selenium in cerebrospinal fluid from thirty-eight ALS patients to those of thirty-eight reference neurological patients matched on age and gender. We found that higher concentrations of inorganic selenium in the form of selenite and of human serum albumin-bound selenium were associated with increased ALS risk (relative risks 3.9 (95% confidence interval 1.2–11.0) and 1.7 (1.0–2.9) for 0.1µg/l increase). Conversely, lower concentrations of selenoprotein P-bound selenium were associated with increased risk (relative risk 0.2 for 1µg/l increase, 95% confidence interval 0.04–0.8). The associations were stronger among cases age 50 years or older, who are postulated to have lower rates of genetic disease origin. These results suggest that excess selenite and human serum albumin bound-selenium and low levels of selenoprotein P-bound selenium in the central nervous system, which may be related, may play a role in ALS etiology. PMID:23732511

  10. Optical limiting properties of silver nanoparticles fabricated by laser ablation

    NASA Astrophysics Data System (ADS)

    Ong, T. S.; Lee, S. S.; Van, L. H.; Hong, Ming Hui; Chong, Tow Chong

    2004-10-01

    Silver nanoparticles have been fabricated by laser ablation of a silver metal foil in solution. The presence of sodium bis(2-ethylhexyl) sulfosuccinate increases the yield of the nanoparticles and enhances their stability. The optical limiting performance of the silver nanoparticles embedded in a PMMA film is compared to that in an aqueous solution.

  11. Nanocomposite anode materials for sodium-ion batteries

    DOEpatents

    Manthiram, Arumugam; Kim Il, Tae; Allcorn, Eric

    2016-06-14

    The disclosure relates to an anode material for a sodium-ion battery having the general formula AO.sub.x--C or AC.sub.x--C, where A is aluminum (Al), magnesium (Mg), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), zirconium (Zr), molybdenum (Mo), tungsten (W), niobium (Nb), tantalum (Ta), silicon (Si), or any combinations thereof. The anode material also contains an electrochemically active nanoparticles within the matrix. The nanoparticle may react with sodium ion (Na.sup.+) when placed in the anode of a sodium-ion battery. In more specific embodiments, the anode material may have the general formula M.sub.ySb-M'O.sub.x--C, Sb-MO.sub.x--C, M.sub.ySn-M'C.sub.x--C, or Sn-MC.sub.x--C. The disclosure also relates to rechargeable sodium-ion batteries containing these materials and methods of making these materials.

  12. ZnVSe2O7 and Cd6V2Se5O21: new d10 transition-metal selenites with V(IV) or V(V) cations.

    PubMed

    Jiang, Hai-Long; Kong, Fang; Fan, Yang; Mao, Jiang-Gao

    2008-08-18

    Two new metal selenites with a combination of vanadium(IV) or vanadium(V) cations, namely, ZnVSe 2O 7 and Cd 6V 2Se 5O 21, have been synthesized by hydrothermal and high-temperature solid-state reactions, respectively. The structure of ZnVSe 2O 7 features a 3D network of vanadium(IV) selenite with 1D tunnels occupied by zinc(II) ions. The 3D network of vanadium(IV) selenite is formed by corner-sharing V (IV)O 6 octahedral chains bridged by selenite groups. In Cd 6V 2Se 5O 21, the interconnection of cadmium(II) ions by bridging and chelating selenite groups led to a 3D framework with large tunnels along the b axis, and the 1D chains of corner-sharing V (V)O 4 tetrahedra are inserted in the above large tunnels and are bonded to the cadmium selenite framework via Cd-O-V bridges. Both compounds exhibit broad emission bands in the blue-light region. Results of magnetic property measurements show there is significant antiferromagnetic interaction between V (4+) centers in ZnVSe 2O 7. The electronic structure calculations for both compounds have been also performed. PMID:18576595

  13. Diclofenac sodium overdose

    MedlinePlus

    Diclofenac sodium is a prescription medicine used to relieve pain and swelling. It is a nonsteroidal anti-inflammatory drug (NSAID). Diclofenac sodium overdose occurs when someone takes more than the ...

  14. Sodium Ferric Gluconate Injection

    MedlinePlus

    Sodium ferric gluconate injection is used to treat iron-deficiency anemia (a lower than normal number of ... are also receiving the medication epoetin (Epogen, Procrit). Sodium ferric gluconate injection is in a class of ...

  15. Docusate Sodium and Pregnancy

    MedlinePlus

    ... live chat Live Help Fact Sheets Share Docusate Sodium Friday, 01 April 2016 In every pregnancy, a ... This sheet talks about whether exposure to docusate sodium may increase the risk for birth defects over ...

  16. Sodium carbonate poisoning

    MedlinePlus

    Sodium carbonate (known as washing soda or soda ash) is a chemical found in many household and ... products. This article focuses on poisoning due to sodium carbonate. This article is for information only. Do ...

  17. Diclofenac sodium overdose

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/002630.htm Diclofenac sodium overdose To use the sharing features on this page, please enable JavaScript. Diclofenac sodium is a prescription medicine used to relieve pain ...

  18. Fractional excretion of sodium

    MedlinePlus

    FE sodium; FENa ... to a lab. There, they are examined for salt (sodium) and creatinine levels. Creatinine is a chemical waste ... your normal foods with a normal amount of salt, unless otherwise instructed by your health care provider. ...

  19. Sodium blood test

    MedlinePlus

    ... able to conserve water) Too much salt or sodium bicarbonate in the diet Use of certain medicines, including corticosteroids, laxatives, lithium, and medicines such as ibuprofen or naproxen Lower than normal sodium level is called hyponatremia. It may be due ...

  20. Formation of Se (0) Nanoparticles by Duganella sp. andAgrobacterium sp. isolated from Se-laden soil of North-East Punjab, India

    PubMed Central

    2012-01-01

    Background Selenium (Se) is an essential trace element, but is toxic at high concentrations. Depending upon the geological background, the land use or on anthropogenic pollution, different amounts of Se may be present in soil. Its toxicity is related to the oxyanions selenate and selenite as they are water soluble and bioavailable. Microorganisms play an important role in Se transformations in soil and its cycling in the environment by transforming water-soluble oxyanions into water insoluble, non-toxic elemental Se (0). For this study, soil samples were collected from selenium-contaminated agricultural soils of Punjab/India to enrich and isolate microbes that interacted with the Se cycle. Results A mixed microbial culture enriched from the arable soil of Punjab could reduce 230 mg/l of water soluble selenite to spherical Se (0) nanoparticles during aerobic growth as confirmed by SEM-EDX. Four pure cultures (C 1, C 4, C 6, C 7) of Gram negative, oxidase and catalase positive, aerobic bacteria were isolated from this mixed microbial consortium and identified by 16 S rDNA gene sequence alignment as two strains of Duganella sp. (C 1, C 4) and two strains of Agrobacterium sp.(C 6, C 7). SEM/TEM-EDX analyses of the culture broth of the four strains revealed excretion of uniformly round sharply contoured Se (0) nanoparticles by all cultures. Their size ranged from 140–200 nm in cultures of strains C 1 and C 4, and from 185–190 nm in cultures of strains C 6 and C 7. Both Duganella sp. revealed better selenite reduction efficiencies than the two Agrobacterium sp. Conclusions This is the first study reporting the capability of newly isolated, aerobically growing Duganella sp. and Agrobacterium sp. from soils of Punjab/India to form spherical, regularly formed Se (0) nanoparticles from water soluble selenite. Among others, the four strains may significantly contribute to the biogeochemical cycling of Se in soil. Bioconversion of toxic selenite to non-toxic Se (0

  1. Mechanism of selenite removal by a mixed adsorbent based on Fe-Mn hydrous oxides studied using X-ray absorption spectroscopy.

    PubMed

    Chubar, Natalia; Gerda, Vasyl; Szlachta, Małgorzata

    2014-11-18

    Selenium cycling in the environment is greatly controlled by various minerals, including Mn and Fe hydrous oxides. At the same time, such hydrous oxides are the main inorganic ion exchangers suitable (on the basis of their chemical nature) to sorb (toxic) anions, separating them from water solutions. The mechanism of selenite adsorption by the new mixed adsorbent composed of a few (amorphous and crystalline) phases [maghemite, MnCO3, and X-ray amorphous Fe(III) and Mn(III) hydrous oxides] was studied by extended X-ray absorption fine structure (EXAFS) spectroscopy [supported by Fourier transform infrared (FTIR) and X-ray diffraction (XRD) data]. The complexity of the porous adsorbent, especially the presence of the amorphous phases of Fe(III) and Mn(III) hydrous oxides, is the main reason for its high selenite removal performance demonstrated by batch and column adsorption studies shown in the previous work. Selenite was bound to the material via inner-sphere complexation (via oxygen) to the adsorption sites of the amorphous Fe(III) and Mn(III) oxides. This anion was attracted via bidentate binuclear corner-sharing coordination between SeO3(2-) trigonal pyramids and both FeO6 and MnO6 octahedra; however, the adsorption sites of Fe(III) hydrous oxides played a leading role in selenite removal. The contribution of the adsorption sites of Mn(III) oxide increased as the pH decreased from 8 to 6. Because most minerals have a complex structure (they are seldom based on individual substances) of various crystallinity, this work is equally relevant to environmental science and environmental technology because it shows how various solid phases control cycling of chemical elements in the environment. PMID:25325790

  2. Variation in Drug Sensitivity of Malignant Mesothelioma Cell Lines with Substantial Effects of Selenite and Bortezomib, Highlights Need for Individualized Therapy

    PubMed Central

    Szulkin, Adam; Nilsonne, Gustav; Mundt, Filip; Wasik, Agata M.; Souri, Pega; Hjerpe, Anders; Dobra, Katalin

    2013-01-01

    Background Malignant mesothelioma cells have an epithelioid or sarcomatoid morphology, both of which may be present in the same tumor. The sarcomatoid phenotype is associated with worse prognosis and heterogeneity of mesothelioma cells may contribute to therapy resistance, which is often seen in mesothelioma. This study aimed to investigate differences in sensitivity between mesothelioma cell lines to anti-cancer drugs. We studied two novel drugs, selenite and bortezomib and compared their effect to four conventional drugs. We also investigated the immunoreactivity of potential predictive markers for drug sensitivity; Pgp, MRP-1, ERCC1, RRM1, TS, xCT and proteasome 20S subunit. Materials and methods We treated six mesothelioma cell lines with selenite, bortezomib, carboplatin, pemetrexed, doxorubicin or gemcitabine as single agents and in combinations. Viability was measured after 24 and 48 hours. Immunocytochemistry was used to detect predictive markers. Results As a single agent, selenite was effective on four out of six cell lines, and in combination with bortezomib yielded the greatest response in the studied mesothelioma cell lines. Cells with an epithelioid phenotype were generally more sensitive to the different drugs than the sarcomatoid cells. Extensive S-phase arrest was seen in pemetrexed-sensitive cell lines. MRP-1 predicted sensitivity of cell lines to treatment with carboplatin and xCT predicted pemetrexed effect. Conclusions The observed heterogeneity in sensitivity of mesothelioma cell lines with different morphology highlights the need for more individualized therapy, requiring development of methods to predict drug sensitivity of individual tumors. Selenite and bortezomib showed a superior effect compared to conventional drugs, motivating clinical testing of these agents as future treatment regime components for patients with malignant mesothelioma. PMID:23840376

  3. Rechargeable sodium alloy anode

    SciTech Connect

    Jow, T.R.

    1988-06-28

    A secondary battery is described comprising: (a) an anode which comprises an alloy of sodium and one or metals selected from the group consisting of tin, lead antimony, bismuth, selenium and tellerium, (b) an electrolyte comprising one or more organic solvents and one or more sodium salts dissolved therein forming dissolved sodium cations in solution; and (c) a cathode; the sodium cations from the electrolyte alloying with the one or more metals of the alloy in the anode during the charging of the battery and sodium in the alloy disoloving in the electrolyte during the discharging of the battery.

  4. Synthesis of noble metal nanoparticles

    NASA Astrophysics Data System (ADS)

    Bahadory, Mozhgan

    Improved methods were developed for the synthesis of noble metal nanoparticles. Laboratory experiments were designed for introducing of nanotechnology into the undergraduate curriculum. An optimal set of conditions for the synthesis of clear yellow colloidal silver was investigated. Silver nanoparticles were obtained by borohydride reduction of silver nitrate, a method which produces particles with average size of 12+/-2 nm, determined by Transmission Electron Microscopy (TEM). The plasmon absorbance is at 397 nm and the peak width at half maximum (PWHM) is 70-75 nm. The relationship between aggregation and optical properties was determined along with a method to protect the particles using polyvinylpyrrolidone (PVP). A laboratory experiment was designed in which students synthesize yellow colloidal silver, estimate particle size using visible spectroscopy, and study aggregation effects. The synthesis of the less stable copper nanoparticles is more difficult because copper nanopaticles are easily oxidized. Four methods were used for the synthesis of copper nanoparticles, including chemical reduction with sodium borohydride, sodium borohydride with potassium iodide, isopropyl alcohol with cetyltrimethylammonium bormide (CTAB) and reducing sugars. The latter method was also the basis for an undergraduate laboratory experiment. For each reaction, the dependence of stability of the copper nanoparticles on reagent concentrations, additives, relative amounts of reactants, and temperature is explored. Atomic force microscopy (AFM), TEM and UV-Visible Spectroscopy were used to characterize the copper nanoparticles. A laboratory experiment to produce copper nanoparticles from household chemicals was developed.

  5. Modelling Cometary Sodium Tails

    NASA Astrophysics Data System (ADS)

    Birkett, K. S.; Jones, G. H.; Coates, A. J.

    2013-12-01

    Neutral sodium is readily observed in cometary spectra and can be seen to form its own distinct tail at high activity comets. Solar radiation pressure accelerates the sodium atoms antisunward and, as strong sodium absorption lines are present in the solar spectrum, the magnitude of this force is dependent upon the Doppler shift of the incident solar radiation. Therefore the heliocentric velocity of the sodium atom directly determines its acceleration. This can produce unique effects, such as a stagnation region. Sodium is relatively easy to detect and so can potentially be used to trace mechanisms in the coma that are otherwise difficult to observe. The source of neutral sodium in the tail currently remains unknown. We have therefore developed a new, three dimensional Monte-Carlo model of neutral cometary sodium in order to facilitate testing of different source production functions. It includes weightings due to neutral sodium lifetime, variation of cometary sodium emission due to Fraunhofer absorption lines and solar flux variation with heliocentric distance. The Swings and Greenstein effects, which can have particularly dramatic effects in near-Sun comets, are also considered comprehensively. Preliminary results from this model are presented, focusing on a comparison of predictions of the neutral sodium tail of Comet C/2012 S1 (ISON) with initial observations.

  6. Pegylation increases platelet biocompatibility of gold nanoparticles.

    PubMed

    Santos-Martinez, Maria Jose; Rahme, Kamil; Corbalan, J Jose; Faulkner, Colm; Holmes, Justin D; Tajber, Lidia; Medina, Carlos; Radomski, Marek Witold

    2014-06-01

    The increasing use of gold nanoparticles in medical diagnosis and treatment has raised the concern over their blood compatibility. The interactions of nanoparticles with blood components may lead to platelet aggregation and endothelial dysfunction. Therefore, medical applications of gold nanoparticles call for increased nanoparticle stability and biocompatibility. Functionalisation of nanoparticles with polythelene glycol (PEGylation) is known to modulate cell-particle interactions. Therefore, the aim of the current study was to investigate the effects of PEGylated-gold nanoparticles on human platelet function and endothelial cells in vitro. Gold nanoparticles, 15 nm in diameter, were synthesised in water using sodium citrate as a reducing and stabilising agent. Functionalised polyethylene glycol-based thiol polymers were used to coat and stabilise pre-synthesised gold nanoparticles. The interaction of gold nanoparticles-citrate and PEGylated-gold nanoparticles with human platelets was measured by Quartz Crystal Microbalance with Dissipation. Platelet-nanoparticles interaction was imaged using phase-contrast, scanning and transmission electron microscopy. The inflammatory effects of gold nanoparticles-citrate and PEGylated-gold nanoparticles in endothelial cells were measured by quantitative real time polymerase chain reaction. PEGylated-gold nanoparticles were stable under physiological conditions and PEGylated-gold nanoparticles-5400 and PEGylated-gold nanoparticles-10800 did not affect platelet aggregation as measured by Quartz Crystal Microbalance with Dissipation. In addition, PEGylated-gold nanoparticles did not induce an inflammatory response when incubated with endothelial cells. Therefore, this study shows that PEGylated-gold nanoparticles with a higher molecular weight of the polymer chain are both platelet- and endothelium-compatible making them attractive candidates for biomedical applications. PMID:24749395

  7. Sodium remote from Io

    NASA Astrophysics Data System (ADS)

    Brown, R. A.; Schneider, N. M.

    1981-12-01

    Measurements of sodium emission lines originating in the middle Jupiter magnetosphere are measured, confirming the wide dispersal of neutral sodium in the Jovian system in at least two distinct manifestations. Candidate neutral transport processes in the context of the observed kinematical signatures are discussed. It is argued that the normal emission feature is produced by sodium atoms on bound elliptical orbits originating in the Io sodium cloud but with apojove in the field of view. Observations of the fast sodium feature indicate that atoms episodically acquire a broad range of line-of-sight velocities above the Jupiter gravitational escape speed and far above the speeds characteristic of surface-sputtered atoms. Three suggested reactions are distinguished according to (1) production rates based on estimated plasmaspheric properties, (2) kinematical signature, and (3) the timing of occurrences of the fast sodium feature.

  8. Effects of sodium selenite on some biochemical and hematological parameters of rainbow trout (Oncorhynchus mykiss Walbaum, 1792) exposed to Pb2+ and Cu2+.

    PubMed

    Ates, Burhan; Orun, Ibrahim; Talas, Zeliha Selamoglu; Durmaz, Gokhan; Yilmaz, Ismet

    2008-03-01

    This study was carried out to understand the preventive effect of selenium (Se4+) on heavy metal stress induced by lead and copper in rainbow trout (Oncorhynchus mykiss). Variation in glutathione peroxidase (Se-GSH-Px) and superoxide dismutase (SOD) activity, and in malondialdehyde (MDA) levels in liver, spleen, heart, and brain tissues of rainbow trout after 72 h of exposure to Pb2+ and Cu2+ were investigated in the presence and absence of Se4+. In the presence of Se4+, Se-GSH-Px activity and SOD activity were found to be higher and MDA levels were lower compared with in its absence. Hematological parameters were also determined and it has been observed that total leukocyte count (WBC), mean cell volume (MCV), and mean cell hemoglobin (MCH) were increased and erythrocyte number (RBC), hemoglobin (Hb), and hematocrit value (Hct; P < 0.05) were decreased in fish exposed to heavy metals in the absence of selenium. Selenium presence recovered hematological parameters to normal levels. In the light of our findings, it could be stated that Pb2+ and Cu2+ lead to dramatic changes in biochemical and hematological parameters and selenium caused these parameters to converge to control levels when it was administered concurrently with these heavy metals. PMID:18649023

  9. Sodium Polystyrene Sulfonate

    MedlinePlus

    ... allergic to sodium polystyrene sulfonate, other polystyrene sulfonate resins, any other medications, or any of the ingredients ... salt substitutes containing potassium or foods that are high in potassium.

  10. Metabolism of selenium (Se) in rats chronically poisoned with D- or L-selenomethionine (SeMet), selenite or selenate

    SciTech Connect

    McAdam, P.A.; Levander, O.A.

    1986-03-01

    L-SeMet is a potential cancer chemoprevention agent for humans. Little difference was seen in the acute toxicity of L vs. D-SeMet in rats. To study chronic toxicity, weanling male rats were fed purified diets containing 2.5, 5.0 or 10 ppm Se as L-SeMet, D-SeMet, Na/sub 2/SeO/sub 3/ or Na/sub 2/SeO/sub 4/ for 6 weeks. Controls received 0.1 ppm Se as selenite. All rats fed 10 ppm Se died within 29 days. Se fed as D-SeMet was retained in the tissues as strongly as L-SeMet. Rats fed D or L-SeMet deposited large amounts of Se in muscle not reflected by proportionate increases in either plasma or RBC Se. Therefore, attempts to follow increases in Se body burden in individuals supplemented with large doses of L-SeMet by monitoring plasma or whole blood Se levels should be interpreted with caution.

  11. Thermophysical properties of sodium

    NASA Technical Reports Server (NTRS)

    Golden, G. H.; Tokar, J. V.

    1969-01-01

    Assessment is given of physical and thermodynamic properties of sodium. FORTRAN subroutine computes enthalphy and entropy of sodium in given state, and composition, molecular weight, volume, and compressibility factor of corresponding vapor. Tabular results for saturated liquid and vapor are presented for a 500-2500 degree F range.

  12. Decode the Sodium Label Lingo

    MedlinePlus

    ... For Preschooler For Gradeschooler For Teen Decode the Sodium Label Lingo Published January 24, 2013 Print Email Reading food labels can help you slash sodium. Here's how to decipher them. "Sodium free" or " ...

  13. New insights into the chemical structure of Y2Ti2O7-δ nanoparticles in oxide dispersion-strengthened steels designed for sodium fast reactors by electron energy-loss spectroscopy

    NASA Astrophysics Data System (ADS)

    Badjeck, V.; Walls, M. G.; Chaffron, L.; Malaplate, J.; March, K.

    2015-01-01

    In this paper we study by high resolution scanning transmission electron microscopy coupled with electron energy-loss spectroscopy (STEM-EELS) an oxide dispersion-strengthened (ODS) steel with the nominal composition Fe-14Cr-1W-0.3TiH2-0.3Y2O3 (wt.%) designed to withstand the extreme conditions met in Gen. IV nuclear reactors. After denoising via principal component analysis (PCA) the data are analyzed using independent component analysis (ICA) which is useful in the investigation of the physical properties and chemical structure of the material by separating the individual spectral responses. The Y-Ti-O nanoparticles are found to be homogeneously distributed in the ferritic matrix, sized from 1 to 20 nm and match a non-stoichiometric pyrochlore-Y2Ti2O7-δ structure for sizes greater than 5 nm. We show that they adopt a (Y-Ti-O)-Cr core-shell structure and that Cr also segregates at the matrix grain boundaries, which may slightly modify the corrosion properties of the steel. Using Ti-L2,3 and O-K fine structure (ELNES) the Ti oxidation state is shown to vary from the center of the nanoparticles to their periphery, from Ti4+ in distorted Oh symmetry to a valency often lower than 3+. The sensitivity of the Ti "white lines" ELNES to local symmetry distortions is also shown to be useful when investigating the strain induced in the nanoparticles by the surrounding matrix. The Cr-shell and the variation of the Ti valence state highlight a complex nanoparticle-matrix interface.

  14. METHOD FOR REMOVING SODIUM OXIDE FROM LIQUID SODIUM

    DOEpatents

    Bruggeman, W.H.; Voorhees, B.G.

    1957-12-01

    A method is described for removing sodium oxide from a fluent stream of liquid sodium by coldtrapping the sodium oxide. Apparatus utilizing this method is disclosed in United States Patent No. 2,745,552. Sodium will remain in a molten state at temperatures below that at which sodium oxide will crystallize out and form solid deposits, therefore, the contaminated stream of sodium is cooled to a temperature at which the solubility of sodium oxide in sodium is substantially decreased. Thereafter the stream of sodium is passed through a bed of stainless steel wool maintained at a temperature below that of the stream. The stream is kept in contact with the wool until the sodium oxide is removed by crystal growth on the wool, then the stream is reheated and returned to the system. This method is useful in purifying reactor coolants where the sodium oxide would otherwise deposit out on the walls and eventually plug the coolant tubes.

  15. Selenite Reduction by Anaerobic Microbial Aggregates: Microbial Community Structure, and Proteins Associated to the Produced Selenium Spheres

    PubMed Central

    Gonzalez-Gil, Graciela; Lens, Piet N. L.; Saikaly, Pascal E.

    2016-01-01

    Certain types of anaerobic granular sludge, which consists of microbial aggregates, can reduce selenium oxyanions. To envisage strategies for removing those oxyanions from wastewater and recovering the produced elemental selenium (Se0), insights into the microbial community structure and synthesis of Se0 within these microbial aggregates are required. High-throughput sequencing showed that Veillonellaceae (c.a. 20%) and Pseudomonadaceae (c.a.10%) were the most abundant microbial phylotypes in selenite reducing microbial aggregates. The majority of the Pseudomonadaceae sequences were affiliated to the genus Pseudomonas. A distinct outer layer (∼200 μm) of selenium deposits indicated that bioreduction occurred in the outer zone of the microbial aggregates. In that outer layer, SEM analysis showed abundant intracellular and extracellular Se0 (nano)spheres, with some cells having high numbers of intracellular Se0 spheres. Electron tomography showed that microbial cells can harbor a single large intracellular sphere that stretches the cell body. The Se0 spheres produced by the microorganisms were capped with organic material. X-ray photoelectron spectroscopy (XPS) analysis of extracted Se0 spheres, combined with a mathematical approach to analyzing XPS spectra from biological origin, indicated that proteins and lipids were components of the capping material associated to the Se0 spheres. The most abundant proteins associated to the spheres were identified by proteomic analysis. Most of the proteins or peptide sequences capping the Se0 spheres were identified as periplasmic outer membrane porins and as the cytoplasmic elongation factor Tu protein, suggesting an intracellular formation of the Se0 spheres. In view of these and previous findings, a schematic model for the synthesis of Se0 spheres by the microorganisms inhabiting the granular sludge is proposed. PMID:27199909

  16. Selenite Reduction by Anaerobic Microbial Aggregates: Microbial Community Structure, and Proteins Associated to the Produced Selenium Spheres.

    PubMed

    Gonzalez-Gil, Graciela; Lens, Piet N L; Saikaly, Pascal E

    2016-01-01

    Certain types of anaerobic granular sludge, which consists of microbial aggregates, can reduce selenium oxyanions. To envisage strategies for removing those oxyanions from wastewater and recovering the produced elemental selenium (Se(0)), insights into the microbial community structure and synthesis of Se(0) within these microbial aggregates are required. High-throughput sequencing showed that Veillonellaceae (c.a. 20%) and Pseudomonadaceae (c.a.10%) were the most abundant microbial phylotypes in selenite reducing microbial aggregates. The majority of the Pseudomonadaceae sequences were affiliated to the genus Pseudomonas. A distinct outer layer (∼200 μm) of selenium deposits indicated that bioreduction occurred in the outer zone of the microbial aggregates. In that outer layer, SEM analysis showed abundant intracellular and extracellular Se(0) (nano)spheres, with some cells having high numbers of intracellular Se(0) spheres. Electron tomography showed that microbial cells can harbor a single large intracellular sphere that stretches the cell body. The Se(0) spheres produced by the microorganisms were capped with organic material. X-ray photoelectron spectroscopy (XPS) analysis of extracted Se(0) spheres, combined with a mathematical approach to analyzing XPS spectra from biological origin, indicated that proteins and lipids were components of the capping material associated to the Se(0) spheres. The most abundant proteins associated to the spheres were identified by proteomic analysis. Most of the proteins or peptide sequences capping the Se(0) spheres were identified as periplasmic outer membrane porins and as the cytoplasmic elongation factor Tu protein, suggesting an intracellular formation of the Se(0) spheres. In view of these and previous findings, a schematic model for the synthesis of Se(0) spheres by the microorganisms inhabiting the granular sludge is proposed. PMID:27199909

  17. Submersible sodium pump

    DOEpatents

    Brynsvold, Glen V.; Lopez, John T.; Olich, Eugene E.; West, Calvin W.

    1989-01-01

    An electromagnetic submerged pump has an outer cylindrical stator with an inner cylindrical conductive core for the submerged pumping of sodium in the cylindrical interstitial volume defined between the stator and core. The cylindrical interstitial volume is typically vertically oriented, and defines an inlet at the bottom and an outlet at the top. The outer stator generates upwardly conveyed toroidal magnetic fields, which fields convey preferably from the bottom of the pump to the top of the pump liquid sodium in the cold leg of a sodium cooled nuclear reactor. The outer cylindrical stator has a vertically disposed duct surrounded by alternately stacked layers of coil units and laminates.

  18. SODIUM DEUTERIUM REACTOR

    DOEpatents

    Oppenheimer, E.D.; Weisberg, R.A.

    1963-02-26

    This patent relates to a barrier system for a sodium heavy water reactor capable of insuring absolute separation of the metal and water. Relatively cold D/sub 2/O moderator and reflector is contained in a calandria into which is immersed the fuel containing tubes. The fuel elements are cooled by the sodium which flows within the tubes and surrounds the fuel elements. The fuel containing tubes are surrounded by concentric barrier tubes forming annular spaces through which pass inert gases at substantially atmospheric pressure. Header rooms above and below the calandria are provided for supplying and withdrawing the sodium and inert gases in the calandria region. (AEC)

  19. Submersible sodium pump

    DOEpatents

    Brynsvold, G.V.; Lopez, J.T.; Olich, E.E.; West, C.W.

    1989-11-21

    An electromagnetic submerged pump has an outer cylindrical stator with an inner cylindrical conductive core for the submerged pumping of sodium in the cylindrical interstitial volume defined between the stator and core. The cylindrical interstitial volume is typically vertically oriented, and defines an inlet at the bottom and an outlet at the top. The outer stator generates upwardly conveyed toroidal magnetic fields, which fields convey preferably from the bottom of the pump to the top of the pump liquid sodium in the cold leg of a sodium cooled nuclear reactor. The outer cylindrical stator has a vertically disposed duct surrounded by alternately stacked layers of coil units and laminates. 14 figs.

  20. Sodium hypochlorite poisoning

    MedlinePlus

    ... poisoning, especially if the product is mixed with ammonia. This article is for information only. Do NOT ... hypochlorite, which may cause severe injury. NEVER mix ammonia with sodium hypochlorite (bleach or bleach-containing products). ...

  1. Sodium bisulfate poisoning

    MedlinePlus

    ... in large amounts. This article discusses poisoning from swallowing sodium bisulfate. This article is for information only. ... Symptoms from swallowing more than a tablespoon of this acid may include: Burning pain in the mouth Chest pain from burns ...

  2. Sodium hydroxide poisoning

    MedlinePlus

    Agency for Toxic Substances and Disease Registry (ATSDR). Medical Management Guidelines for Sodium Hydroxide (NaOH) . Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service. Available at: www.atsdr.cdc. ...

  3. Sodium Polystyrene Sulfonate

    MedlinePlus

    ... comes as a suspension and as an oral powder for suspension to take by mouth. The suspension ... evenly.If you are taking sodium polystyrene sulfonate powder by mouth, mix the powder with 20 to ...

  4. Sodium hypochlorite dental accidents.

    PubMed

    Goswami, Mridula; Chhabra, Nidhi; Kumar, Gyanendra; Verma, Mahesh; Chhabra, Anuj

    2014-02-01

    Sodium hypochlorite is widely used in dentistry as an intra-canal irrigant, for debridement and to disinfect root canals. Although it is considered to be safe, serious mishap can result from its inappropriate use, and this has been reported infrequently in the literature. Two unusual cases of sodium hypochlorite toxicity and their successful non-surgical management are described in a 14-year-old girl and a 13-year-old boy. PMID:24090808

  5. Controlled Variable Oxidative Doping of Individual Organometallic Nanoparticles.

    PubMed

    Feng, Ann; Cheng, Wei; Holter, Jennifer; Young, Neil; Compton, Richard G

    2016-05-10

    The charging and controlled oxidative doping of single organometallic ferrocene nanoparticles is reported in aqueous sodium tetrafluoroborate using the nano-impacts method. It is shown that ferrocene nanoparticles of approximately 105 nm diameter are essentially quantitatively oxidatively doped with the uptake of one tetrafluoroborate anion per ferrocene molecule at suitably high overpotentials. By using lower potentials, it is possible to achieve low doping levels of single nanoparticles in a controlled manner. PMID:27038252

  6. A novel sonication route to prepare anthracene nanoparticles

    SciTech Connect

    Kang Peng; Chen Chunnian; Hao Lingyun; Zhu Chunling; Hu Yuan; Chen Zuyao

    2004-04-02

    A novel sonication method has been successfully developed for the preparation of anthracene nanoparticles. The as-prepared nanoparticles are characterized using transmission electron microscopy, ultraviolet-visible absorption spectroscopy, fluorescence excitation and emission spectroscopy. Nanoparticles prepared with sonication are smaller and better dispersed than with magnetic stirring. Surfactants cetyltrimethylammonium bromide, bis(2-ethylhexyl)sodium sulfosuccinate, sodium dodecyl sulfonate and polyvinylpyrrolidone are used to control the size and morphology. Excimer band is found at 445 and 472 nm and possible mechanism is discussed.

  7. Lysozyme loading and release from Se doped hydroxyapatite nanoparticles.

    PubMed

    Wang, Yanhua; Hao, Hang; Zhang, Shengmin

    2016-04-01

    Element-substituted hydroxyapatite (HA) based nanocomposites have become a promising therapeutic material for improving bone defect repair. Selenium substituted HA nanoparticles can both induce apoptosis of bone tumor cells and enhance osteointegration. However, the effect of selenite ions on the proteins in combination with the HA nanoparticles remains to be elucidated. Here, we investigated the influence of selenium doping concentration on the loading and release of lysozyme (LSM) as a model protein drug. The selenium substituted HA-LSM composites with different doping concentrations were synthesized and characterized. The subsequent delivery of lysozyme was studied in a phosphate buffer solution (PBS). We found that selenium substituted HA-LSM composites with Se:P=10% showed the highest amount of lysozyme loading (41.7%), whereas the amount of lysozyme loaded in undoped HA nanoparticles was the lowest (34.1%). The doped selenium interacts with lysozyme molecules, which leads to the increase of β-sheet and unordered, and the decrease of self-association, α-helix and β-turns in protein structures. Moreover, selenium addition significantly slows the protein release from HA-LSM composites. The composites with Se:P=10% release lysozyme at the slightly slower rate among the samples with different Se doping concentrations. It also shows that the released lysozyme retains most of its enzymatic activity. PMID:26838882

  8. Io's sodium cloud

    NASA Astrophysics Data System (ADS)

    Goldberg, B. A.; Garneau, G. W.; Lavoie, S. K.

    1984-11-01

    The first two-dimensional images of the source region of Io's neutral sodium cloud have been acquired by ground-based observation. Observed asymmetries in its spatial brightness distribution provide new evidence that the cloud is supplied by sodium that is ejected nonisotropically from Io or its atmosphere. Complementary, high-time-resolution, calibrated image sequences that give the first comprehensive picture of the variations of the fainter regions of the cloud extending more than 100,000 kilometers from Io were also obtained. These data demonstrate that the cloud exhibits a persistent systematic behavior coupled with Io's orbital position, a distinct 'east-west orbital asymmetry', a variety of spatial morphologies, and true temporal changes. The geometric stability of the sodium source is also indicated. Isolation of the cloud's temporal changes constitutes an important milestone toward its utilization as a long-term probe of Io and the inner Jovian magnetosphere.

  9. Sodium sulfur battery seal

    DOEpatents

    Mikkor, Mati

    1981-01-01

    This disclosure is directed to an improvement in a sodium sulfur battery construction in which a seal between various battery compartments is made by a structure in which a soft metal seal member is held in a sealing position by holding structure. A pressure applying structure is used to apply pressure on the soft metal seal member when it is being held in sealing relationship to a surface of a container member of the sodium sulfur battery by the holding structure. The improvement comprises including a thin, well-adhered, soft metal layer on the surface of the container member of the sodium sulfur battery to which the soft metal seal member is to be bonded.

  10. Magnetic Carbon Nanotubes Tethered with Maghemite Nanoparticles

    NASA Astrophysics Data System (ADS)

    Kim, Il Tae; Nunnery, Grady; Jacob, Karl; Schwartz, Justin; Liu, Xiaotao; Tannenbaum, Rina

    2011-03-01

    We describe a novel, facile method for the synthesis of magnetic carbon nanotubes (m-CNTs) decorated with monodisperse γ - Fe 2 O3 magnetic (maghemite) nanoparticles and their aligned feature in a magnetic field. The tethering of the nanoparticles was achieved by the initial activation of the surface of the CNTs with carboxylic acid groups, followed by the attachment of the γ - Fe 2 O3 nanoparticles via a modified sol-gel process. Sodium dodecylbenzene sulfonate (NaDDBS) was introduced into the suspension to prevent the formation of an iron oxide 3D network. Various characterization methods were used to confirm the formation of well-defined maghemite nanoparticles. The tethered nanoparticles imparted magnetic characteristics to the CNTs, which became superparamagnetic. The m-CNTs were oriented parallel to the direction of a magnetic field. This has the potential of enhancing various properties, e.g. mechanical and electrical properties, in composite materials.

  11. Chlorite (sodium salt)

    Integrated Risk Information System (IRIS)

    Chlorite ( sodium salt ) ; CASRN 7758 - 19 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarc

  12. Dalapon, sodium salt

    Integrated Risk Information System (IRIS)

    Dalapon , sodium salt ; CASRN 75 - 99 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinoge

  13. Sodium sulfur battery seal

    DOEpatents

    Topouzian, Armenag

    1980-01-01

    This invention is directed to a seal for a sodium sulfur battery in which a flexible diaphragm sealing elements respectively engage opposite sides of a ceramic component of the battery which separates an anode compartment from a cathode compartment of the battery.

  14. In situ growth and performance of spherical Fe2F5·H2O nanoparticles in multi-walled carbon nanotube network matrix as cathode material for sodium ion batteries

    NASA Astrophysics Data System (ADS)

    Jiang, Miaoling; Wang, Xianyou; Hu, Hai; Wei, Shuangying; Fu, Yanqing; Shen, Yongqiang

    2016-06-01

    The multi-wall carbon nanotubes wired spherical Fe2F5·H2O particles (MWCNTs-wired Fe2F5·H2O) are synthesized via an ionic liquid (IL) based precipitation route as the cathode material for sodium ion batteries (SIBs), in which the IL 1-butyl-2,3-dimethylimidazolium tetrafluoroborate (BMMimBF4) is used as environmentally friendly fluorine source, appropriate solvent and binder. The structure, morphology and electrochemical performance of the as-prepared samples have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), charge/discharge tests, cyclic voltammetric measurements (CV). The results show that the MWCNTs-wired spherical Fe2F5·H2O particles present the cubic crystal structure with the cell volume of 1.12821 nm3. Moreover, the SEM and TEM images show that the spherical Fe2F5·H2O particles and disentangled MWCNTs are intertwined together to form a chestnut-like micrometer-sized aggregates. Furthermore, the MWCNTs-wired spherical Fe2F5·H2O particles show a high initial discharge capacity of 251.2 mAh g-1 at 20 mA g-1 in the voltage of 1.0-4.0 V, and the corresponding reversible discharge capacity is 197.4 mAh g-1. Comparing with bare Fe2F5·H2O, the discharge capacity of the MWCNTs-wired spherical Fe2F5·H2O particles still can maintain about 115.0 mAh g-1 after 50 cycles when the current density increased to 100 mA g-1, and the corresponding capacity retention reaches 90.2%.

  15. In situ growth and performance of spherical Fe2F5·H2O nanoparticles in multi-walled carbon nanotube network matrix as cathode material for sodium ion batteries

    NASA Astrophysics Data System (ADS)

    Jiang, Miaoling; Wang, Xianyou; Hu, Hai; Wei, Shuangying; Fu, Yanqing; Shen, Yongqiang

    2016-06-01

    The multi-wall carbon nanotubes wired spherical Fe2F5·H2O particles (MWCNTs-wired Fe2F5·H2O) are synthesized via an ionic liquid (IL) based precipitation route as the cathode material for sodium ion batteries (SIBs), in which the IL 1-butyl-2,3-dimethylimidazolium tetrafluoroborate (BMMimBF4) is used as environmentally friendly fluorine source, appropriate solvent and binder. The structure, morphology and electrochemical performance of the as-prepared samples have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), charge/discharge tests, cyclic voltammetric measurements (CV). The results show that the MWCNTs-wired spherical Fe2F5·H2O particles present the cubic crystal structure with the cell volume of 1.12821 nm3. Moreover, the SEM and TEM images show that the spherical Fe2F5·H2O particles and disentangled MWCNTs are intertwined together to form a chestnut-like micrometer-sized aggregates. Furthermore, the MWCNTs-wired spherical Fe2F5·H2O particles show a high initial discharge capacity of 251.2 mAh g-1 at 20 mA g-1 in the voltage of 1.0-4.0 V, and the corresponding reversible discharge capacity is 197.4 mAh g-1. Comparing with bare Fe2F5·H2O, the discharge capacity of the MWCNTs-wired spherical Fe2F5·H2O particles still can maintain about 115.0 mAh g-1 after 50 cycles when the current density increased to 100 mA g-1, and the corresponding capacity retention reaches 90.2%.

  16. Preparation of Hydrochlorothiazide Nanoparticles for Solubility Enhancement.

    PubMed

    Vaculikova, Eliska; Cernikova, Aneta; Placha, Daniela; Pisarcik, Martin; Peikertova, Pavlina; Dedkova, Katerina; Devinsky, Ferdinand; Jampilek, Josef

    2016-01-01

    Nanoparticles can be considered as a useful tool for improving properties of poorly soluble active ingredients. Hydrochlorothiazide (Class IV of the Biopharmaceutical Classification System) was chosen as a model compound. Antisolvent precipitation-solvent evaporation and emulsion solvent evaporation methods were used for preparation of 18 samples containing hydrochlorothiazide nanoparticles. Water solutions of surfactants sodium dodecyl sulfate, Tween 80 and carboxymethyl dextran were used in mass concentrations of 1%, 3% and 5%. Acetone and dichloromethane were used as solvents of the model compound. The particle size of the prepared samples was measured by dynamic light scattering. The selected sample of hydrochlorothiazide nanoparticles stabilized with carboxymethyl dextran sodium salt with particle size 2.6 nm was characterized additionally by Fourier transform mid-infrared spectroscopy and scanning electron microscopy. It was found that the solubility of this sample was 6.5-fold higher than that of bulk hydrochlorothiazide. PMID:27490530

  17. Detection of Leishmania-specific DNA and surface antigens using a combination of functionalized magnetic beads and cadmium selenite quantum dots.

    PubMed

    Andreadou, Margarita; Liandris, Emmanouil; Gazouli, Maria; Mataragka, Antonia; Tachtsidis, Ilias; Goutas, Nikolaοs; Vlachodimitropoulos, Dimitrios; Ikonomopoulos, John

    2016-04-01

    Leishmaniosis is a zoonotic disease that affects millions of people especially in resource-poor settings. The development of reliable diagnostic assays that do not require dedicated equipment or highly trained personnel would improve early diagnosis and effective control. For this purpose, a combination of magnetic bead and cadmium selenite quantum dot probes was applied for the detection of Leishmania-specific surface antigens (proteins) and DNA. Both analytes are isolated from the solution using magnetic bead capture probes whereas the presence of the targeted molecules is demonstrated by quantum dot detection probes. The sensitivity and specificity of this method reached 100% based on an assessment performed on 55 cultured isolates of various microbial pathogens. The low limit of detection was 3125 ng/μl and 10(3)cells/ml for Leishmania DNA and protein, respectively. The method shows considerable potential for clinical application in human and veterinary medicine, especially in resource-poor settings. PMID:26658854

  18. Towards high throughput screening of nanoparticle flotation collectors.

    PubMed

    Abarca, Carla; Yang, Songtao; Pelton, Robert H

    2015-12-15

    To function as flotation collectors for mineral processing, polymeric nanoparticles require a delicate balance of surface properties to give mineral-specific deposition and colloidal stability in high ionic strength alkaline media, while remaining sufficiently hydrophobic to promote flotation. Combinatorial nanoparticle surface modification, in conjunction with high throughput screening, is a promising approach for nanoparticle development. However, efficient automated screening assays are required to reject ineffective particles without having to undergo time consuming flotation testing. Herein we demonstrate that determining critical coagulation concentrations of sodium carbonate in combination with measuring the advancing water contact angle of nanoparticle-saturated glass surfaces can be used to screen ineffective nanoparticles. Finally, none of our first nanoparticle library based on poly(ethylene glycol) methyl ether methacrylate (PEG-methacrylate) were effective flotation collectors because the nanoparticles were too hydrophilic. PMID:26319325

  19. Expansion of the rich structures and magnetic properties of neptunium selenites: soft ferromagnetism in Np(SeO3)2.

    PubMed

    Diefenbach, Kariem; Lin, Jian; Cross, Justin N; Dalal, Naresh S; Shatruk, Michael; Albrecht-Schmitt, Thomas E

    2014-07-21

    Two new neptunium selenites with different oxidation states of the metal centers, Np(IV)(SeO3)2 and Np(VI)O2(SeO3), have been synthesized under mild hydrothermal conditions at 200 °C from the reactions of NpO2 and SeO2. Np(SeO3)2 crystallizes as brown prisms (space group P21/n, a = 7.0089(5) Å, b = 10.5827(8) Å, c = 7.3316(5) Å, β = 106.953(1)°); whereas NpO2(SeO3) crystals are garnet-colored with an acicular habit (space group P21/m, a = 4.2501(3) Å, b = 9.2223(7) Å, c = 5.3840(4) Å, β = 90.043(2)°). Single-crystal X-ray diffraction studies reveal that the structure of Np(SeO3)2 features a three-dimensional (3D) framework consisting of edge-sharing NpO8 units that form chains that are linked via SeO3 units to create a 3D framework. NpO2(SeO3) possesses a lamellar structure in which each layer is composed of NpO8 hexagonal bipyramids bridged via SeO3(2-) anions. Bond-valence sum calculations and UV-vis-NIR absorption spectra support the assignment of tetravalent and hexavalent states of neptunium in Np(SeO3)2 and NpO2(SeO3), respectively. Magnetic susceptibility data for Np(SeO3)2 deviates substantially from typical Curie-Weiss behavior, which can be explained by large temperature-independent paramagnetic (TIP) effects. The Np(IV) selenite shows weak ferromagnetic ordering at 3.1(1) K with no detectable hysteresis, suggesting soft ferromagnetic behavior. PMID:24964359

  20. Preserved Expression of mRNA Coding von Willebrand Factor–Cleaving Protease ADAMTS13 by Selenite and Activated Protein C

    PubMed Central

    Ekaney, Michael L; Bockmeyer, Clemens L; Sossdorf, Maik; Reuken, Philipp A; Conradi, Florian; Schuerholz, Tobias; Blaess, Markus F; Friedman, Scott L; Lösche, Wolfgang; Bauer, Michael; Claus, Ralf A

    2015-01-01

    In sepsis, the severity-dependent decrease of von Willebrand factor (VWF)–inactivating protease, a disintegrin and metalloproteinase with thrombospondin motifs 13 (ADAMTS13), results in platelet aggregation and consumption, leading to sepsis-associated thrombotic microangiopathy (TMA) and organ failure. Previous reports assessing its functional deficiency have pinpointed involvement of autoantibodies or mutations to propagate thrombotic thrombocytopenic purpura (TTP). However, mechanisms of acquired ADAMTS13 deficiency during host response remain unclear. To enhance understanding of ADAMTS13 deficiency in sepsis, we evaluated changes in expression of mRNA coding ADAMTS13 during septic conditions using primary cellular sources of the protease. We hypothesized that proinflammatory cytokines and constituents of serum from septic patients affect the transcriptional level of ADAMTS13 in vitro, and previously recommended therapeutic agents as adjunctive therapy for sepsis interact therewith. Cultured hepatic stellate cells (HSCs), endothelial cells (HMEC) and human precision-cut liver slices as an ex vivo model were stimulated with sepsis prototypic cytokines, bacterial endotoxin and pooled serum obtained from septic patients. Stimulation resulted in a significant decrease in ADAMTS13 mRNA between 10% and 80% of basal transcriptional rates. Costimulation of selenite or recombinant activated protein C (APC) with serum prevented ADAMTS13 decrease in HSCs and increased ADAMTS13 transcripts in HMEC. In archived clinical samples, the activity of ADAMTS13 in septic patients treated with APC (n = 5) increased with an accompanying decrease in VWF propeptide as surrogate for improved endothelial function. In conclusion, proinflammatory conditions of sepsis repress mRNA coding ADAMTS13 and the ameliorating effect by selenite and APC may support the concept for identification of beneficial mechanisms triggered by these drugs at a molecular level. PMID:25860876

  1. Sodium disorders in the elderly.

    PubMed Central

    Tareen, Naureen; Martins, David; Nagami, Glenn; Levine, Barton; Norris, Keith C.

    2005-01-01

    Disorders of sodium imbalance are commonly encountered in clinical practice and can have a substantial impact on the prognosis of the patient. These disorders are more common in the elderly. Sodium disorders can cause serious neurologic symptoms and even death, particularly among hospitalized patients. The identification of sodium abnormalities and appropriate clinical intervention are critical for improving patient outcomes. Early recognition of hyponatremia and hypernatremia can provide a clue to an underlying disorder. In this update, we have summarized age-related homeostatic changes that impair sodium balance, medications that alter salt and water handling, and the recognition and management of sodium disorders in elderly patients. PMID:15712785

  2. 21 CFR 184.1733 - Sodium benzoate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... GRAS § 184.1733 Sodium benzoate. (a) Sodium benzoate is the chemical benzoate of soda (C7H5NaO2), produced by the neutralization of benzoic acid with sodium bicarbonate, sodium carbonate, or sodium... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium benzoate. 184.1733 Section 184.1733...

  3. 21 CFR 184.1736 - Sodium bicarbonate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium bicarbonate. 184.1736 Section 184.1736 Food... Specific Substances Affirmed as GRAS § 184.1736 Sodium bicarbonate. (a) Sodium bicarbonate (NaHCO3, CAS Reg. No. 144-55-8) is prepared by treating a sodium carbonate or a sodium carbonate and sodium...

  4. 21 CFR 184.1736 - Sodium bicarbonate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium bicarbonate. 184.1736 Section 184.1736 Food... GRAS § 184.1736 Sodium bicarbonate. (a) Sodium bicarbonate (NaHCO3, CAS Reg. No. 144-55-8) is prepared by treating a sodium carbonate or a sodium carbonate and sodium bicarbonate solution with...

  5. 21 CFR 184.1736 - Sodium bicarbonate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium bicarbonate. 184.1736 Section 184.1736 Food... Specific Substances Affirmed as GRAS § 184.1736 Sodium bicarbonate. (a) Sodium bicarbonate (NaHCO3, CAS Reg. No. 144-55-8) is prepared by treating a sodium carbonate or a sodium carbonate and sodium...

  6. 21 CFR 184.1736 - Sodium bicarbonate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium bicarbonate. 184.1736 Section 184.1736 Food... Specific Substances Affirmed as GRAS § 184.1736 Sodium bicarbonate. (a) Sodium bicarbonate (NaHCO3, CAS Reg. No. 144-55-8) is prepared by treating a sodium carbonate or a sodium carbonate and sodium...

  7. 21 CFR 201.64 - Sodium labeling.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... this section). (e) The term very low sodium may be used in the labeling of OTC drug products intended.... (f) The term low sodium may be used in the labeling of OTC drug products intended for oral ingestion... the term sodium. (h) The terms sodium free, very low sodium, and low sodium shall be in print size...

  8. Effects of the Reducing Agents on Morphologies of Gold Nanoparticles in POLY(STYRENE-B-4-VINYLPYRIDINE) Micelles

    NASA Astrophysics Data System (ADS)

    Ali, Nauman; Kim, Dong-Hun; Park, Lee-Soon; Kang, Inn-Kyu; Yoon, Keun-Byoung; Kwak, Giseop; Park, Soo-Young

    The effects of the reducing agents of hydrazine (H4N2), sodium borohydride (NaBH4), and triethylsilane (C6H15Si) on the morphologies of gold nanoparticles in the poly(styrene-b-4-vinylpyridine) micelle were studied using small-angle X-ray scattering (SAXS), UV/visible spectroscopy and transmission electron microscopy (TEM). "Cherry" morphology was found in the gold nanoparticles reduced by hydrazine while "raspberry" morphology was found in the gold nanoparticles reduced by sodium borohydride. Hydrazine was more effective in reducing gold nanoparticle in the core of the PS-b-P4VP micelle than sodium borohydride and triethylsilane. The nanoparticles reduced by hydrazine were confined in the core and more regular than those reduced by sodium borohydride and triethylsilane. The possible mechanism leading to these morphological differences was also discussed.

  9. A stable room-temperature sodium-sulfur battery

    NASA Astrophysics Data System (ADS)

    Wei, Shuya; Xu, Shaomao; Agrawral, Akanksha; Choudhury, Snehashis; Lu, Yingying; Tu, Zhengyuan; Ma, Lin; Archer, Lynden A.

    2016-06-01

    High-energy rechargeable batteries based on earth-abundant materials are important for mobile and stationary storage technologies. Rechargeable sodium-sulfur batteries able to operate stably at room temperature are among the most sought-after platforms because such cells take advantage of a two-electron-redox process to achieve high storage capacity from inexpensive electrode materials. Here we report a room-temperature sodium-sulfur battery that uses a microporous carbon-sulfur composite cathode, and a liquid carbonate electrolyte containing the ionic liquid 1-methyl-3-propylimidazolium-chlorate tethered to SiO2 nanoparticles. We show that these cells can cycle stably at a rate of 0.5 C (1 C=1675, mAh g-1) with 600 mAh g-1 reversible capacity and nearly 100% Coulombic efficiency. By means of spectroscopic and electrochemical analysis, we find that the particles form a sodium-ion conductive film on the anode, which stabilizes deposition of sodium. We also find that sulfur remains interred in the carbon pores and undergo solid-state electrochemical reactions with sodium ions.

  10. A stable room-temperature sodium-sulfur battery.

    PubMed

    Wei, Shuya; Xu, Shaomao; Agrawral, Akanksha; Choudhury, Snehashis; Lu, Yingying; Tu, Zhengyuan; Ma, Lin; Archer, Lynden A

    2016-01-01

    High-energy rechargeable batteries based on earth-abundant materials are important for mobile and stationary storage technologies. Rechargeable sodium-sulfur batteries able to operate stably at room temperature are among the most sought-after platforms because such cells take advantage of a two-electron-redox process to achieve high storage capacity from inexpensive electrode materials. Here we report a room-temperature sodium-sulfur battery that uses a microporous carbon-sulfur composite cathode, and a liquid carbonate electrolyte containing the ionic liquid 1-methyl-3-propylimidazolium-chlorate tethered to SiO2 nanoparticles. We show that these cells can cycle stably at a rate of 0.5 C (1 C=1675, mAh g(-1)) with 600 mAh g(-1) reversible capacity and nearly 100% Coulombic efficiency. By means of spectroscopic and electrochemical analysis, we find that the particles form a sodium-ion conductive film on the anode, which stabilizes deposition of sodium. We also find that sulfur remains interred in the carbon pores and undergo solid-state electrochemical reactions with sodium ions. PMID:27277345

  11. Extracellular polymeric substances govern the surface charge of biogenic elemental selenium nanoparticles.

    PubMed

    Jain, Rohan; Jordan, Norbert; Weiss, Stephan; Foerstendorf, Harald; Heim, Karsten; Kacker, Rohit; Hübner, René; Kramer, Herman; van Hullebusch, Eric D; Farges, François; Lens, Piet N L

    2015-02-01

    The origin of the organic layer covering colloidal biogenic elemental selenium nanoparticles (BioSeNPs) is not known, particularly in the case when they are synthesized by complex microbial communities. This study investigated the presence of extracellular polymeric substances (EPS) on BioSeNPs. The role of EPS in capping the extracellularly available BioSeNPs was also examined. Fourier transform infrared (FT-IR) spectroscopy and colorimetric measurements confirmed the presence of functional groups characteristic of proteins and carbohydrates on the BioSeNPs, suggesting the presence of EPS. Chemical synthesis of elemental selenium nanoparticles in the presence of EPS, extracted from selenite fed anaerobic granular sludge, yielded stable colloidal spherical selenium nanoparticles. Furthermore, extracted EPS, BioSeNPs, and chemically synthesized EPS-capped selenium nanoparticles had similar surface properties, as shown by ζ-potential versus pH profiles and isoelectric point measurements. This study shows that the EPS of anaerobic granular sludge form the organic layer present on the BioSeNPs synthesized by these granules. The EPS also govern the surface charge of these BioSeNPs, thereby contributing to their colloidal properties, hence affecting their fate in the environment and the efficiency of bioremediation technologies. PMID:25536371

  12. Sodium channel Nax is a regulator in epithelial sodium homeostasis.

    PubMed

    Xu, Wei; Hong, Seok Jong; Zhong, Aimei; Xie, Ping; Jia, Shengxian; Xie, Zhong; Zeitchek, Michael; Niknam-Bienia, Solmaz; Zhao, Jingling; Porterfield, D Marshall; Surmeier, D James; Leung, Kai P; Galiano, Robert D; Mustoe, Thomas A

    2015-11-01

    The mechanisms by which the epidermis responds to disturbances in barrier function and restores homeostasis are unknown. With a perturbation of the epidermal barrier, water is lost, resulting in an increase in extracellular sodium concentration. We demonstrate that the sodium channel Nax functions as a sodium sensor. With increased extracellular sodium, Nax up-regulates prostasin, which results in activation of the sodium channel ENaC, resulting in increased sodium flux and increased downstream mRNA synthesis of inflammatory mediators. Nax is present in multiple epithelial tissues, and up-regulation of its downstream genes is found in hypertrophic scars. In animal models, blocking Nax expression results in improvement in scarring and atopic dermatitis-like symptoms, both of which are pathological conditions characterized by perturbations in barrier function. These findings support an important role for Nax in maintaining epithelial homeostasis. PMID:26537257

  13. Functional Application of Noble Metal Nanoparticles In Situ Synthesized on Ramie Fibers

    NASA Astrophysics Data System (ADS)

    Tang, Bin; Yao, Ya; Li, Jingliang; Qin, Si; Zhu, Haijin; Kaur, Jasjeet; Chen, Wu; Sun, Lu; Wang, Xungai

    2015-09-01

    Different functions were imparted to ramie fibers through treatment with noble metal nanoparticles including silver and gold nanoparticles. The in situ synthesis of silver and gold nanoparticles was achieved by heating in the presence of ramie fibers in the corresponding solutions of precursors. The unique optical property of synthesized noble metal nanoparticles, i.e., localized surface plasmon resonance, endowed ramie fibers with bright colors. Color strength (K/S) of fibers increased with heating temperature. Silver nanoparticles were obtained in alkaline solution, while acidic condition was conducive to gold nanoparticles. The optical properties of treated ramie fibers were investigated using UV-vis absorption spectroscopy. Scanning electron microscopy (SEM) was employed to observe the morphologies of silver and gold nanoparticles in situ synthesized on fibers. The ramie fibers treated with noble metal nanoparticles showed remarkable catalytic activity for reduction of 4-nitrophenol (4-NP) by sodium borohydride. Moreover, the silver nanoparticle treatment showed significant antibacterial property on ramie fibers.

  14. Intermetallic nanoparticles

    SciTech Connect

    Singh, Dileep; Yusufoglu, Yusuf; Timofeeva, Elena; Routbort, Jules L.

    2015-11-20

    A process for preparing intermetallic nanoparticles of two or more metals is provided. In particular, the process includes the steps: a) dispersing nanoparticles of a first metal in a solvent to prepare a first metal solution, b) forming a reaction mixture with the first metal solution and a reducing agent, c) heating the reaction mixture to a reaction temperature; and d) adding a second metal solution containing a salt of a second metal to the reaction mixture. During this process, intermetallic nanoparticles, which contain a compound with the first and second metals are formed. The intermetallic nanoparticles with uniform size and a narrow size distribution is also provided. An electrochemical device such as a battery with the intermetallic nanoparticles is also provided.

  15. Intermetallic nanoparticles

    SciTech Connect

    Singh, Dileep; Yusufoglu, Yusuf; Timofeeva, Elena; Routbort, Jules

    2015-07-14

    A process for preparing intermetallic nanoparticles of two or more metals is provided. In particular, the process includes the steps: a) dispersing nanoparticles of a first metal in a solvent to prepare a first metal solution, b) forming a reaction mixture with the first metal solution and a reducing agent, c) heating the reaction mixture to a reaction temperature; and d) adding a second metal solution containing a salt of a second metal to the reaction mixture. During this process, intermetallic nanoparticles, which contain a compound with the first and second metals are formed. The intermetallic nanoparticles with uniform size and a narrow size distribution is also provided. An electrochemical device such as a battery with the intermetallic nanoparticles is also provided.

  16. Combination of carmustine and selenite effectively inhibits tumor growth by targeting androgen receptor, androgen receptor-variants, and Akt in preclinical models: New hope for patients with castration resistant prostate cancer.

    PubMed

    Thamilselvan, Vijayalakshmi; Menon, Mani; Thamilselvan, Sivagnanam

    2016-10-01

    Despite established androgen receptor (AR) antagonists, AR/AR-variants signaling remain a major obstacle for the successful treatment of castration resistant prostate cancer (CRPC). In addition, CRPC cells adapt to survive via AR-independent pathways to escape next generation therapies. Therefore, there is an urgent need for drugs that can target these signaling pathways in CRPC. In this study, we sought to determine whether carmustine and selenite in combination could induce apoptosis and inhibit growth of CRPC in-vitro and in-vivo. CRPC (22Rv1, VCaP, and PC-3) cell lines in culture and xenograft mouse were used. Combination of carmustine and selenite treatment significantly increased reactive oxygen species, apoptosis and growth inhibition in CRPC cells with down regulation of anti-apoptotic (Bcl-2 and Mcl-1) and proliferative proteins (c-Myc and cyclin-D1). This effect was associated with complete reduction of AR/AR-variants, AR-V7, PSA and significant induction of p27Kip1. Combination treatment substantially abolished phospho-Akt, phospho-GSK-3β, and anchorage-independent growth in AR-positive and AR-negative cells. Consistent with in-vitro results, combination treatment effectively induced apoptosis and completely inhibited xenograft tumor growth and markedly reduced AR/AR-variants, AR-V7, PSA, and Bcl-2 in xenograft tumors without causing genotoxicity in host mice. Individual agent treatment showed only partial effect. The combination treatment showed a significant synergistic effect. The present study is the first to demonstrate that the combination of carmustine and selenite treatment completely suppressed CRPC tumor growth by reducing AR/AR-variants and Akt signaling. Our findings suggest that the combination of carmustine and selenite could constitute a promising next-generation therapy for successful treatment of patients with CRPC. PMID:27198552

  17. Sodium homeostasis with chronic sodium loading in preascitic cirrhosis

    PubMed Central

    Wong, F; Liu, P; Blendis, L

    2001-01-01

    BACKGROUND—Preascitic cirrhotic patients receiving 200 mmol of sodium daily for seven days remain in positive sodium balance. Thereafter, sodium handling is unknown.
AIM—To assess renal sodium handling in preascitic cirrhosis on a high sodium diet for five weeks.
METHODS—Sixteen biopsy proven preascitic cirrhotics were assessed at weekly intervals for five weeks on a diet of 200 mmol sodium/day using a daily weight diary and weekly 24 hour urinary sodium estimations. Fasting supine neurohormone levels were measured at baseline and weekly for five weeks while haemodynamics were measured at baseline and at five weeks.
RESULTS—The daily diet of 200 mmol of sodium resulted in weight gain and a positive sodium balance for three weeks, associated with significant suppression of plasma renin activity and aldosterone levels, and a significant rise in plasma atrial natriuretic peptide levels (p<0.05). Patients' weights plateaued during week 4, associated with complete sodium balance and significant suppression of plasma noradrenaline levels (p<0.05). This was followed by a negative sodium balance and weight loss, and finally complete sodium balance, again despite a mean net gain of 2.3 (0.3) kg, associated with a return of plasma renin activity and aldosterone levels to within normal ranges. The lack of increase in central blood volume in addition to the persistent increase in plasma atrial natriuretic peptide levels indicated that residual volume expansion, consequent to persistent weight gain, was distributed on the venous side of the circulation. No free fluid was seen on repeat abdominal ultrasound after five weeks.
CONCLUSION—Preascitic cirrhotics have a natriuretic "escape" after three weeks on high sodium dietary intake, associated with elevated plasma atrial natriuretic peptide levels and suppression of the renin-angiotensin-aldosterone system. With continued suppressed sympathetic activity, preascitics re-establish complete sodium balance

  18. Mercury's sodium exosphere

    NASA Astrophysics Data System (ADS)

    Schmidt, Carl A.

    In this dissertation I examine the properties and origins of the most energetic component of Mercury's atmosphere and how it couples to the planet's magnetosphere and space environment. Mercury' s atmosphere consists of particles liberated from its surface that follow ballistic, collisionless trajectories under the influence of gravity and solar radiation pressure. This tenuous atmosphere can be classified as an exosphere where the exobase boundary is the planet's surface. To explain how this exosphere is sustained, a number of theories have been presented: (1) thermal evaporation from the hot surface; (2) photo-desorption of surface materials by UV solar radiation; (3) sputtering by plasma surface interactions; and (4) vaporization of the surface by micro-meteorite impacts. Using a 3-dimensional numerical model, I determine the role each source has in populating the exosphere. New observations of Mercury's escaping atmosphere are presented using novel imaging techniques in which sodium acts as a tracer to identify atmospheric sources. I discuss the implications of these measurements for our understanding of the physical processes at work in the exosphere, and provide a foundation for modeling such processes. For the first time, this work quantifies the variability in the loss of Mercury's sodium as a seasonal effect. My observations show that atmospheric escape can, at times, exceed 1024 Na atoms/s, nearly twice the highest rate previously reported. By forward modeling Mercury' s atmospheric escape, I place new constraints on the source properties and eliminate the prevailing theory that the escaping tail is sputtered from the surface by solar wind ions. The MESSENGER spacecraft has recently discovered that sodium is distributed unevenly over the surface and that the magnetosphere is offset from the planet's center. Using the first model to include these effects, I demonstrate the magnetosphere's influence upon exospheric sources by simulating asymmetries observed

  19. Preparation of silver nanoparticles at low temperature

    NASA Astrophysics Data System (ADS)

    Mishra, Mini; Chauhan, Pratima

    2016-04-01

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

  20. Magnetometry with mesospheric sodium

    PubMed Central

    Higbie, James M.; Rochester, Simon M.; Patton, Brian; Holzlöhner, Ronald; Bonaccini Calia, Domenico; Budker, Dmitry

    2011-01-01

    Measurement of magnetic fields on the few 100-km length scale is significant for many geophysical applications including mapping of crustal magnetism and ocean circulation measurements, yet available techniques for such measurements are very expensive or of limited accuracy. We propose a method for remote detection of magnetic fields using the naturally occurring atomic sodium-rich layer in the mesosphere and existing high-power lasers developed for laser guide star applications. The proposed method offers a dramatic reduction in cost and opens the way to large-scale, parallel magnetic mapping and monitoring for atmospheric science, navigation, and geophysics. PMID:21321235

  1. Magnetometry with mesospheric sodium.

    PubMed

    Higbie, James M; Rochester, Simon M; Patton, Brian; Holzlöhner, Ronald; Bonaccini Calia, Domenico; Budker, Dmitry

    2011-03-01

    Measurement of magnetic fields on the few 100-km length scale is significant for many geophysical applications including mapping of crustal magnetism and ocean circulation measurements, yet available techniques for such measurements are very expensive or of limited accuracy. We propose a method for remote detection of magnetic fields using the naturally occurring atomic sodium-rich layer in the mesosphere and existing high-power lasers developed for laser guide star applications. The proposed method offers a dramatic reduction in cost and opens the way to large-scale, parallel magnetic mapping and monitoring for atmospheric science, navigation, and geophysics. PMID:21321235

  2. Sodium bicarbonate in chemical flooding: Part 1: Topical report. [Sodium bicarbonate and sodium carbonate

    SciTech Connect

    Peru, D.A.; Lorenz, P.B.

    1987-07-01

    To compare oil recovery and alkali consumption in alkaline flooding using sodium bicarbonate with other alkaline agents, coreflooding experiments were performed in turn with viscosified sodium bicarbonate and viscosified sodium carbonate solutions. Oil recovery was monitored, and the effluent brine from these corefloods was analyzed for silicon, aluminum, pH, and total inorganic carbon. The results indicate that viscosified sodium bicarbonate recovered more of the asphaltic Cerro-Negro crude than of the less asphaltic Wilmington crude oil. The recovery efficiency using the viscosified sodium carbonate was similar for the two crudes. For both crudes, the percent oil recovery using viscosified sodium carbonate was slightly higher than that using the viscosified sodium bicarbonate. Mineral dissolution and decrease in pH were found to be greater in corefloods using viscosified sodium carbonate. Total inorganic carbon recovery can be obtained in corefloods with either agent, provided that a sufficient water drive follows the chemical slug. Long-term experiments were performed by recirculating alkaline solutions through oil-free, unfired Berea sandstone to monitor the rock/alkali interactions. The experimental results indicate an eight-fold decrease in quartz dissolution by sodium bicarbonate compared with sodium carbonate. Moderate magnesium solubility was observed at the pH of the bicarbonate solution. Low solubility of magnesium and aluminum at the pH of the carbonate indicates the possible formation of precipitates. In these experiments 13% of the carbonate was converted to bicarbonate. Total alkalinity was not significantly decreased with either agent. 18 refs., 5 tabs.

  3. Tuning of depletion interaction in nanoparticle-surfactant systems

    SciTech Connect

    Ray, D. Aswal, V. K.

    2014-04-24

    The interaction of anionic silica nanoparticles (Ludox LS30) and non-ionic surfactants decaethylene glycol monododecylether (C12E10) without and with anionic sodium dodecyl sulfate (SDS) in aqueous electrolyte solution has been studied by small-angle neutron scattering (SANS). The measurements have been carried out for fixed concentrations of nanoparticle (1 wt%), surfactants (1 wt%) and electrolyte (0.1 M NaCl). Each of these nanoparticlesurfactant systems has been examined for different contrast conditions where individual components (nanoparticle or surfactant) are made visible. It is observed that the nanoparticle-C12E10 system leads to the depletion-induced aggregation of nanoparticles. The system however behaves very differently on addition of SDS where depletion interaction gets suppressed and aggregation of nanoparticles can be prevented. We show that C12E10 and SDS form mixed micelles and the charge on these micelles plays important role in tuning the depletion interaction.

  4. Slow Sodium: An Oral Slowly Released Sodium Chloride Preparation

    PubMed Central

    Clarkson, E. M.; Curtis, J. R.; Jewkes, R. J.; Jones, B. E.; Luck, V. A.; de Wardener, H. E.; Phillips, N.

    1971-01-01

    The use of a slowly released oral preparation of sodium chloride is described. It was given to patients and athletes to treat or prevent acute and chronic sodium chloride deficiency. Gastrointestinal side effects were not encountered after the ingestion of up to 500 mEq in one day or 200 mEq in 10 minutes. PMID:5569979

  5. A Simple Quantitative Synthesis: Sodium Chloride from Sodium Carbonate.

    ERIC Educational Resources Information Center

    Gold, Marvin

    1988-01-01

    Describes a simple laboratory procedure for changing sodium carbonate into sodium chloride by adding concentrated HCl to cause the reaction and then evaporating the water. Claims a good stoichiometric yield can be obtained in one three-hour lab period. Suggests using fume hood for the reaction. (ML)

  6. Slow sodium: an oral slowly released sodium chloride preparation.

    PubMed

    Clarkson, E M; Curtis, J R; Jewkes, R J; Jones, B E; Luck, V A; de Wardener, H E; Phillips, N

    1971-09-11

    The use of a slowly released oral preparation of sodium chloride is described. It was given to patients and athletes to treat or prevent acute and chronic sodium chloride deficiency. Gastrointestinal side effects were not encountered after the ingestion of up to 500 mEq in one day or 200 mEq in 10 minutes. PMID:5569979

  7. GENOTOXICITY STUDIES OF SODIUM DICHLOROACETATE AND SODIUM TRICHLOROACETATE

    EPA Science Inventory

    The genotoxic properties of sodium dichloroacetate (DCA) and sodium trichloroacetate (TCA)were evaluated in several short-term in vitro and in vivo assays. Neither compound was mutagenic in tester strain TA102 in the Salmonella mutagenicity assay. Both DCA and TCA were weak induc...

  8. Biocidal effects of silver and zinc oxide nanoparticles on the bioluminescent bacteria

    NASA Astrophysics Data System (ADS)

    Taran, M. V.; Starodub, N. F.; Katsev, A. M.; Guidotti, M.; Khranovskyy, V. D.; Babanin, A. A.; Melnychuk, M. D.

    2013-11-01

    The effect of silver and zinc oxide nanoparticles in combination with alginate on bioluminescent Photobacterium leiognathi Sh1 bacteria was investigated. Silver nanoparticles were found to be more toxic than zinc oxide nanoparticles on bioluminescent bacteria. The nanoparticles and their ions released results in the same effect, however, it was absent in combination with alginate. The effective inhibiting concentration (EC50) for silver nanoparticles was found about 0.3 - 0.4 μg mL-1, which was up to two times larger then for zinc oxide nanoparticles. The absence of sodium chloride in the tested media prevented the formation of colloidal particles of larger size and the effective inhibition concentrations of metal derivatives were lower than in the presence of sodium chloride.

  9. Antimicrobial and antioxidant effects of sodium acetate, sodium lactate, and sodium citrate in refrigerated sliced salmon

    PubMed Central

    Sallam, Khalid Ibrahim

    2007-01-01

    This study was carried out to evaluate the microbiological quality and lipid oxidation of fresh salmon slices treated by dipping in 2.5% (w/v) aqueous solution of sodium acetate (NaA), sodium lactate (NaL), or sodium citrate (NaC) and stored at 1 °C. The results revealed that these salts were efficient (P < 0.05) against the proliferation of various categories of spoilage microorganisms; including aerobic and psychrotrophic populations, Pseudomonas spp., H2S-producing bacteria, lactic acid bacteria, and Enterobacteriaceae. The general order of antibacterial activity of the different organic salts used was; sodium acetate > sodium lactate > sodium citrate. Lipid oxidation, as expressed by peroxide value (PV) and thiobarbituric acid (TBA) value, was significantly (P < 0.05) delayed in NaA- and NaC-treated samples. The antioxidant activity followed the order: NaC > NaA > NaL. The shelf life of the treated products was extended by 4–7 days more than that of the control. Therefore, sodium acetate, sodium lactate, and sodium citrate can be utilized as safe organic preservatives for fish under refrigerated storage. PMID:17471315

  10. 21 CFR 184.1763 - Sodium hydroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... empirical formula is NaOH. Sodium hydroxide is prepared commercially by the electrolysis of sodium chloride... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium hydroxide. 184.1763 Section 184.1763 Food... Specific Substances Affirmed as GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg....

  11. 21 CFR 184.1763 - Sodium hydroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... empirical formula is NaOH. Sodium hydroxide is prepared commercially by the electrolysis of sodium chloride... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium hydroxide. 184.1763 Section 184.1763 Food... Specific Substances Affirmed as GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg....

  12. 21 CFR 184.1763 - Sodium hydroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... empirical formula is NaOH. Sodium hydroxide is prepared commercially by the electrolysis of sodium chloride... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium hydroxide. 184.1763 Section 184.1763 Food... Specific Substances Affirmed as GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg....

  13. 21 CFR 184.1763 - Sodium hydroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... empirical formula is NaOH. Sodium hydroxide is prepared commercially by the electrolysis of sodium chloride... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium hydroxide. 184.1763 Section 184.1763 Food... Specific Substances Affirmed as GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg....

  14. 21 CFR 201.64 - Sodium labeling.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... contains sodium bicarbonate, sodium phosphate, or sodium biphosphate as an active ingredient for oral... 21 Food and Drugs 4 2013-04-01 2013-04-01 false Sodium labeling. 201.64 Section 201.64 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.64 Sodium labeling. (a) The labeling...

  15. 21 CFR 184.1733 - Sodium benzoate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Specific Substances Affirmed as GRAS § 184.1733 Sodium benzoate. (a) Sodium benzoate is the chemical benzoate of soda (C7H5NaO2), produced by the neutralization of benzoic acid with sodium bicarbonate, sodium... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium benzoate. 184.1733 Section 184.1733...

  16. 21 CFR 201.64 - Sodium labeling.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... contains sodium bicarbonate, sodium phosphate, or sodium biphosphate as an active ingredient for oral... 21 Food and Drugs 4 2011-04-01 2011-04-01 false Sodium labeling. 201.64 Section 201.64 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.64 Sodium labeling. (a) The labeling...

  17. 21 CFR 201.64 - Sodium labeling.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... contains sodium bicarbonate, sodium phosphate, or sodium biphosphate as an active ingredient for oral... 21 Food and Drugs 4 2012-04-01 2012-04-01 false Sodium labeling. 201.64 Section 201.64 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.64 Sodium labeling. (a) The labeling...

  18. 21 CFR 184.1733 - Sodium benzoate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Substances Affirmed as GRAS § 184.1733 Sodium benzoate. (a) Sodium benzoate is the chemical benzoate of soda (C7H5NaO2), produced by the neutralization of benzoic acid with sodium bicarbonate, sodium carbonate, or... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium benzoate. 184.1733 Section 184.1733 Food...

  19. 21 CFR 184.1733 - Sodium benzoate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Specific Substances Affirmed as GRAS § 184.1733 Sodium benzoate. (a) Sodium benzoate is the chemical benzoate of soda (C7H5NaO2), produced by the neutralization of benzoic acid with sodium bicarbonate, sodium... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium benzoate. 184.1733 Section 184.1733...

  20. 21 CFR 201.64 - Sodium labeling.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... contains sodium bicarbonate, sodium phosphate, or sodium biphosphate as an active ingredient for oral... 21 Food and Drugs 4 2014-04-01 2014-04-01 false Sodium labeling. 201.64 Section 201.64 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.64 Sodium labeling. (a) The labeling...

  1. 21 CFR 186.1756 - Sodium formate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium formate. 186.1756 Section 186.1756 Food and....1756 Sodium formate. (a) Sodium formate (CHNaO2, CAS Reg. No. 141-53-7) is the sodium salt of formic acid. It is produced by the reaction of carbon monoxide with sodium hydroxide. (b) The ingredient...

  2. 21 CFR 184.1724 - Sodium alginate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium alginate. 184.1724 Section 184.1724 Food and... Substances Affirmed as GRAS § 184.1724 Sodium alginate. (a) Sodium alginate (CAS Reg. No. 9005-38-3) is the sodium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Sodium alginate...

  3. 21 CFR 184.1724 - Sodium alginate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium alginate. 184.1724 Section 184.1724 Food... GRAS § 184.1724 Sodium alginate. (a) Sodium alginate (CAS Reg. No. 9005-38-3) is the sodium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Sodium alginate is prepared by...

  4. Precision Nanoparticles

    ScienceCinema

    John Hemminger

    2010-01-08

    A revolutionary technology that efficiently produces nanoparticles in uniform and prescribed sizes (1-100 nanometers) using supercritical fluids. INL researcher Robert Fox was joined by Idaho State University researchers Rene Rodriquez and Joshua Pak in d

  5. Polymeric nanoparticles

    PubMed Central

    Bolhassani, Azam; Javanzad, Shabnam; Saleh, Tayebeh; Hashemi, Mehrdad; Aghasadeghi, Mohammad Reza; Sadat, Seyed Mehdi

    2014-01-01

    Nanocarriers with various compositions and biological properties have been extensively applied for in vitro/in vivo drug and gene delivery. The family of nanocarriers includes polymeric nanoparticles, lipid-based carriers (liposomes/micelles), dendrimers, carbon nanotubes, and gold nanoparticles (nanoshells/nanocages). Among different delivery systems, polymeric carriers have several properties such as: easy to synthesize, inexpensive, biocompatible, biodegradable, non-immunogenic, non-toxic, and water soluble. In addition, cationic polymers seem to produce more stable complexes led to a more protection during cellular trafficking than cationic lipids. Nanoparticles often show significant adjuvant effects in vaccine delivery since they may be easily taken up by antigen presenting cells (APCs). Natural polymers such as polysaccharides and synthetic polymers have demonstrated great potential to form vaccine nanoparticles. The development of new adjuvants or delivery systems for DNA and protein immunization is an expanding research field. This review describes polymeric carriers especially PLGA, chitosan, and PEI as vaccine delivery systems. PMID:24128651

  6. Precision Nanoparticles

    SciTech Connect

    John Hemminger

    2009-07-21

    A revolutionary technology that efficiently produces nanoparticles in uniform and prescribed sizes (1-100 nanometers) using supercritical fluids. INL researcher Robert Fox was joined by Idaho State University researchers Rene Rodriquez and Joshua Pak in d

  7. Sodium heat transfer system modeling

    NASA Astrophysics Data System (ADS)

    Baker, A. F.; Fewell, M. E.

    1983-11-01

    The sodium heat transfer system of the international energy agency (IEA) small solar power systems (SSPS) central receiver system (CRS), which includes the heliostat field, receiver, hot and cold storage vessels, and sodium/water steam generator was modeled. The computer code SOLTES (simulator of large thermal energy systems), was used to model this system. The results from SOLTES are compared to measured data.

  8. ID-69 Sodium drain experiments

    SciTech Connect

    Johnston, D.C.

    1996-09-19

    This paper describes experiments to determine the sodium retention and drainage from the two key areas of an ID-69. This information is then used as the initiation point for guidelines of how to proceed with washing an ID-69 in the IEM Cell Sodium Removal System.

  9. Preparation and characterization of silver chloride nanoparticles as an antibacterial agent

    NASA Astrophysics Data System (ADS)

    Duong Trinh, Ngoc; Thanh Binh Nguyen, Thi; Hai Nguyen, Thanh

    2015-12-01

    Silver chloride nanoparticles were prepared by the precipitation reaction between silver nitrate and sodium chloride in an aqueous solution containing poly(vinyl alcohol) as a stabilizing agent. Different characteristics of the nanoparticles in suspension and in lyophilized powder such as size, morphology, chemical nature, interaction with stabilizing agent and photo-stability were investigated. Biological tests showed that the obtained silver chloride nanoparticles displayed antibacterial activities against Escherichia coli and Staphylococcus aureus.

  10. Evolutionary primacy of sodium bioenergetics

    PubMed Central

    Mulkidjanian, Armen Y; Galperin, Michael Y; Makarova, Kira S; Wolf, Yuri I; Koonin, Eugene V

    2008-01-01

    Background The F- and V-type ATPases are rotary molecular machines that couple translocation of protons or sodium ions across the membrane to the synthesis or hydrolysis of ATP. Both the F-type (found in most bacteria and eukaryotic mitochondria and chloroplasts) and V-type (found in archaea, some bacteria, and eukaryotic vacuoles) ATPases can translocate either protons or sodium ions. The prevalent proton-dependent ATPases are generally viewed as the primary form of the enzyme whereas the sodium-translocating ATPases of some prokaryotes are usually construed as an exotic adaptation to survival in extreme environments. Results We combine structural and phylogenetic analyses to clarify the evolutionary relation between the proton- and sodium-translocating ATPases. A comparison of the structures of the membrane-embedded oligomeric proteolipid rings of sodium-dependent F- and V-ATPases reveals nearly identical sets of amino acids involved in sodium binding. We show that the sodium-dependent ATPases are scattered among proton-dependent ATPases in both the F- and the V-branches of the phylogenetic tree. Conclusion Barring convergent emergence of the same set of ligands in several lineages, these findings indicate that the use of sodium gradient for ATP synthesis is the ancestral modality of membrane bioenergetics. Thus, a primitive, sodium-impermeable but proton-permeable cell membrane that harboured a set of sodium-transporting enzymes appears to have been the evolutionary predecessor of the more structurally demanding proton-tight membranes. The use of proton as the coupling ion appears to be a later innovation that emerged on several independent occasions. Reviewers This article was reviewed by J. Peter Gogarten, Martijn A. Huynen, and Igor B. Zhulin. For the full reviews, please go to the Reviewers' comments section. PMID:18380897

  11. 40 CFR 415.170 - Applicability; description of the sodium dichromate and sodium sulfate production subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... sodium dichromate and sodium sulfate production subcategory. 415.170 Section 415.170 Protection of... MANUFACTURING POINT SOURCE CATEGORY Sodium Dichromate and Sodium Sulfate Production Subcategory § 415.170 Applicability; description of the sodium dichromate and sodium sulfate production subcategory. The provisions...

  12. Modulation of Framework and Centricity: Cation Size Effect in New Quaternary Selenites, ASc(SeO3)2 (A = Na, K, Rb, and Cs).

    PubMed

    Song, Seung Yoon; Ok, Kang Min

    2015-05-18

    Four new stoichiometrically equivalent quaternary scandium selenites, ASc(SeO3)2 (A = Na, K, Rb, and Cs) have been hydrothermally synthesized using A2CO3, Sc(NO3)3·xH2O (or ScO3), and SeO2 as starting materials. All four materials share similar bond networks that are composed of corner-shared distorted ScO6 octahedra and SeO3 trigonal pyramids. However, each material reveals different frameworks and centricities. Detailed structural analysis suggests that the structural variation is attributed to the difference in size and subsequent coordination number for the alkali metal cations. Powder second-harmonic generation (SHG) measurements on noncentrosymmetric (NCS) RbSc(SeO3)2 show that the compound has an SHG efficiency similar to that of (NH4)H2PO4. The observed SHG efficiency is due to the remaining net polarization after cancellation of oppositely aligned moments for SeO3 and ScO6 groups. Thorough characterizations such as spectroscopic, thermal, and elemental analyses for the new materials are presented as are dipole moment and out-of-center distortion calculations. PMID:25915517

  13. Isolation of Tellurite- and Selenite-Resistant Bacteria from Hydrothermal Vents of the Juan de Fuca Ridge in the Pacific Ocean

    PubMed Central

    Rathgeber, Christopher; Yurkova, Natalia; Stackebrandt, Erko; Beatty, J. Thomas; Yurkov, Vladimir

    2002-01-01

    Deep-ocean hydrothermal-vent environments are rich in heavy metals and metalloids and present excellent sites for the isolation of metal-resistant microorganisms. Both metalloid-oxide-resistant and metalloid-oxide-reducing bacteria were found. Tellurite- and selenite-reducing strains were isolated in high numbers from ocean water near hydrothermal vents, bacterial films, and sulfide-rich rocks. Growth of these isolates in media containing K2TeO3 or Na2SeO3 resulted in the accumulation of metallic tellurium or selenium. The MIC of K2TeO3 ranged from 1,500 to greater than 2,500 μg/ml, and the MIC of Na2SeO3 ranged from 6,000 to greater than 7,000 μg/ml for 10 strains. Phylogenetic analysis of 4 of these 10 strains revealed that they form a branch closely related to members of the genus Pseudoalteromonas, within the γ-3 subclass of the Proteobacteria. All 10 strains were found to be salt tolerant, pH tolerant, and thermotolerant. The metalloid resistance and morphological, physiological, and phylogenetic characteristics of newly isolated strains are described. PMID:12200320

  14. Method of generating hydrogen gas from sodium borohydride

    DOEpatents

    Kravitz, Stanley H.; Hecht, Andrew M.; Sylwester, Alan P.; Bell, Nelson S.

    2007-12-11

    A compact solid source of hydrogen gas, where the gas is generated by contacting water with micro-disperse particles of sodium borohydride in the presence of a catalyst, such as cobalt or ruthenium. The micro-disperse particles can have a substantially uniform diameter of 1-10 microns, and preferably about 3-5 microns. Ruthenium or cobalt catalytic nanoparticles can be incorporated in the micro-disperse particles of sodium borohydride, which allows a rapid and complete reaction to occur without the problems associated with caking and scaling of the surface by the reactant product sodium metaborate. A closed loop water management system can be used to recycle wastewater from a PEM fuel cell to supply water for reacting with the micro-disperse particles of sodium borohydride in a compact hydrogen gas generator. Capillary forces can wick water from a water reservoir into a packed bed of micro-disperse fuel particles, eliminating the need for using an active pump.

  15. Method of Manufacturing Micro-Disperse Particles of Sodium Borohydride

    DOEpatents

    Kravitz, Stanley H.; Hecht, Andrew M.; Sylwester. Alan P.; Bell, Nelson S.

    2008-09-23

    A compact solid source of hydrogen gas, where the gas is generated by contacting water with micro-disperse particles of sodium borohydride in the presence of a catalyst, such as cobalt or ruthenium. The micro-disperse particles can have a substantially uniform diameter of 1-10 microns, and preferably about 3-5 microns. Ruthenium or cobalt catalytic nanoparticles can be incorporated in the micro-disperse particles of sodium borohydride, which allows a rapid and complete reaction to occur without the problems associated with caking and scaling of the surface by the reactant product sodium metaborate. A closed loop water management system can be used to recycle wastewater from a PEM fuel cell to supply water for reacting with the micro-disperse particles of sodium borohydride in a compact hydrogen gas generator. Capillary forces can wick water from a water reservoir into a packed bed of micro-disperse fuel particles, eliminating the need for using an active pump.

  16. Amorphous and Crystalline Sodium Tantalate Composites for Photocatalytic Water Splitting.

    PubMed

    Grewe, Tobias; Tüysüz, Harun

    2015-10-21

    A facile hydrothermal synthesis protocol for the fabrication of sodium tantalates for photocatalytic water splitting is presented. Mixtures of tantalum and sodium ethoxide precursors were dispersed in ethanol, and ammonium hydroxide solution was used as mineralizer. By adjusting the amount of mineralizer, a variety of sodium tantalates with various morphologies, textural parameters, band gaps, crystal phases, and degrees of crystallinity were fabricated. The reaction was carefully monitored with a pressure sensor inside the autoclave reactor, and the obtained samples were characterized using X-ray diffraction, transmission electron microscopy, N2-physisorption, and ultraviolet-visible light spectroscopy. Among the series, the amorphous sample and the composite sample that consists of amorphous and crystalline phases showed superior activity toward photocatalytic hydrogen production than highly crystalline samples. Particularly, an amorphous sodium tantalate with a small fraction of crystalline nanoparticles with perovskite structure was found to be the most active sample, reaching a hydrogen rate of 3.6 mmol h(-1) from water/methanol without the use of any cocatalyst. Despite its amorphous nature, this photocatalyst gave an apparent photocatalyst activity of 1200 μmol g(-1) L(-1) h(-1) W(1-), which is 4.5-fold higher than highly crystalline NaTaO3. In addition, the most active sample gave promising activity for overall water splitting with a hydrogen production rate of 94 μmol h(-1), which is superior to highly crystalline NaTaO3 prepared by conventional solid-solid state route. PMID:26439706

  17. Sodium fire testing: structural evaluation of sodium fire suppression system

    SciTech Connect

    1984-08-01

    This report describes the development and the lessons learned from the Clinch River Breeder Reactor Sodium Fire Testing Program (DRS 26.03). The purpose of this program was to evaluate the behavior of the Sodium Fire Suppression System and validate the analytical techniques used in the calculation of the effects of sodium fires in air-filled cells. This report focuses on the fire suppression capability and the structural integrity of the Fire Suppression System. System features are discussed; the test facility is described and the key results are provided. Modifications to the fire suppression system and the plant made as a result of test experience are also discussed.

  18. Tables of thermodynamic properties of sodium

    SciTech Connect

    Fink, J.K.

    1982-06-01

    The thermodynamic properties of saturated sodium, superheated sodium, and subcooled sodium are tabulated as a function of temperature. The temperature ranges are 380 to 2508 K for saturated sodium, 500 to 2500 K for subcooled sodium, and 400 to 1600 K for superheated sodium. Tabulated thermodynamic properties are enthalpy, heat capacity, pressure, entropy, density, instantaneous thermal expansion coefficient, compressibility, and thermal pressure coefficient. Tables are given in SI units and cgs units.

  19. 21 CFR 186.1770 - Sodium oleate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium oleate. 186.1770 Section 186.1770 Food and....1770 Sodium oleate. (a) Sodium oleate (C18H33O2Na, CAS Reg. No. 143-19-1) is the sodium salt of oleic.... Commercially, sodium oleate is made by mixing and heating flaked sodium hydroxide and oleic acid. (b)...

  20. Antifungal activity of gold nanoparticles prepared by solvothermal method

    SciTech Connect

    Ahmad, Tokeer; Wani, Irshad A.; Lone, Irfan H.; Ganguly, Aparna; Manzoor, Nikhat; Ahmad, Aijaz; Ahmed, Jahangeer; Al-Shihri, Ayed S.

    2013-01-15

    Graphical abstract: Gold nanoparticles (7 and 15 nm) of very high surface area (329 and 269 m{sup 2}/g) have been successfully synthesized through solvothermal method by using tin chloride and sodium borohydride as reducing agents. As-prepared gold nanoparticles shows very excellent antifungal activity against Candida isolates and activity increases with decrease in the particle size. Display Omitted Highlights: ► Effect of reducing agents on the morphology of gold nanoparticles. ► Highly uniform and monodisperse gold nanoparticles (7 nm). ► Highest surface area of gold nanoparticles (329 m{sup 2/}g). ► Excellent antifungal activity of gold nanoparticles against Candida strains. -- Abstract: Gold nanoparticles have been successfully synthesized by solvothermal method using SnCl{sub 2} and NaBH{sub 4} as reducing agents. X-ray diffraction studies show highly crystalline and monophasic nature of the gold nanoparticles with face centred cubic structure. The transmission electron microscopic studies show the formation of nearly spherical gold nanoparticles of average size of 15 nm using SnCl{sub 2}, however, NaBH{sub 4} produced highly uniform, monodispersed and spherical gold nanoparticles of average grain size of 7 nm. A high surface area of 329 m{sup 2}/g for 7 nm and 269 m{sup 2}/g for 15 nm gold nanoparticles was observed. UV–vis studies assert the excitations over the visible region due to transverse and longitudinal surface plasmon modes. The gold nanoparticles exhibit excellent size dependant antifungal activity and greater biocidal action against Candida isolates for 7 nm sized gold nanoparticles restricting the transmembrane H{sup +} efflux of the Candida species than 15 nm sized gold nanoparticles.

  1. Susceptibility of Clostridium difficile to the food preservatives sodium nitrite, sodium nitrate and sodium metabisulphite.

    PubMed

    Lim, Su-Chen; Foster, Niki F; Riley, Thomas V

    2016-02-01

    Clostridium difficile is an important enteric pathogen of humans and food animals. Recently it has been isolated from retail foods with prevalences up to 42%, prompting concern that contaminated foods may be one of the reasons for increased community-acquired C. difficile infection (CA-CDI). A number of studies have examined the prevalence of C. difficile in raw meats and fresh vegetables; however, fewer studies have examined the prevalence of C. difficile in ready-to-eat meat. The aim of this study was to investigate the in vitro susceptibility of 11 C. difficile isolates of food animal and retail food origins to food preservatives commonly used in ready-to-eat meats. The broth microdilution method was used to determine the minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) for sodium nitrite, sodium nitrate and sodium metabisulphite against C. difficile. Checkerboard assays were used to investigate the combined effect of sodium nitrite and sodium nitrate, commonly used in combination in meats. Modal MIC values for sodium nitrite, sodium nitrate and sodium metabisulphite were 250 μg/ml, >4000 μg/ml and 1000 μg/ml, respectively. No bactericidal activity was observed for all three food preservatives. The checkerboard assays showed indifferent interaction between sodium nitrite and sodium nitrate. This study demonstrated that C. difficile can survive in the presence of food preservatives at concentrations higher than the current maximum permitted levels allowed in ready-to-eat meats. The possibility of retail ready-to-eat meats contaminated with C. difficile acting as a source of CDI needs to be investigated. PMID:26700884

  2. Size-dependent interaction of silica nanoparticles with different surfactants in aqueous solution.

    PubMed

    Kumar, Sugam; Aswal, Vinod K; Kohlbrecher, Joachim

    2012-06-26

    The size-dependent interaction of anionic silica nanoparticles with ionic (anionic and cationic) and nonionic surfactants has been studied using small-angle neutron scattering (SANS). The surfactants used are anionic sodium dodecyl sulfate (SDS), cationic dodecyltrimethyl ammonium bromide (DTAB), and nonionic decaoxyethylene n-dodecylether (C(12)E(10)). The measurements have been carried out for three different sizes of silica nanoparticles (8, 16, and 26 nm) at fixed concentrations (1 wt % each) of nanoparticles and surfactants. It is found that irrespective of the size of the nanoparticles there is no significant interaction evolved between like-charged nanoparticles and the SDS micelles leading to any structural changes. However, the strong attraction of oppositely charged DTAB micelles with silica nanoparticles results in the aggregation of nanoparticles. The number of micelles mediating the nanoparticle aggregation increases with the size of the nanoparticle. The aggregates are characterized by fractal structure where the fractal dimension is found to be constant (D ≈ 2.3) independent of the size of the nanoparticles and consistent with diffusion-limited-aggregation-type fractal morphology in these systems. In the case of nonionic surfactant C(12)E(10), micelles interact with the individual silica nanoparticles. The number of adsorbed micelles per nanoparticle increases drastically whereas the percentage of adsorbed micelles on nanoparticles decreases with the increase in the size of the nanoparticles. PMID:22655980

  3. Biogenic synthesis of metallic nanoparticles and prospects toward green chemistry.

    PubMed

    Adil, Syed Farooq; Assal, Mohamed E; Khan, Mujeeb; Al-Warthan, Abdulrahman; Siddiqui, Mohammed Rafiq H; Liz-Marzán, Luis M

    2015-06-01

    The immense importance of nanoparticles and their applications is a strong motivation for exploring new synthetic techniques. However, due to strict regulations that manage the potential environmental impacts greener alternatives for conventional synthesis are the focus of intense research. In the scope of this perspective, a concise discussion about the use of green reducing and stabilizing agents toward the preparation of metal nanoparticles is presented. Reports on the synthesis of noble metal nanoparticles using plant extracts, ascorbic acid and sodium citrate as green reagents are summarized and discussed, pointing toward an urgent need of understanding the mechanistic aspects of the involved reactions. PMID:25633046

  4. Synthesis and characterization of lanthanum doped zinc oxide nanoparticles

    NASA Astrophysics Data System (ADS)

    Kumar, Vinod; Sonia, Suman, Kumar, Sacheen; Kumar, Dinesh

    2016-05-01

    La doped ZnO (Zn1-xLaxO, x = 0, 3, 6 and 9) were prepared via chemical co-precipitation method using Zinc Acetate, Lanthanum Acetate and Sodium Hydroxide at 50°C. Hydrate nanoparticles were annealed in air at 300°C for 3 hours. The synthesized samples have been characterized by powder X-ray diffraction and UV-Visiblespectrophotometer. The XRD measurement revealsthat the prepared nanoparticles have different microstructure without changing a hexagonal wurtzite structure. The result shows the change in nanoparticles size with the increment of lanthanum concentration for lower concentration for x = 0 to 6 and decreases at x = 9.

  5. Study of structural and optical properties of cupric oxide nanoparticles

    NASA Astrophysics Data System (ADS)

    Dhineshbabu, N. R.; Rajendran, V.; Nithyavathy, N.; Vetumperumal, R.

    2016-08-01

    In this study, cupric oxide (CuO) nanoparticles were synthesized via sonochemical method. The samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscope, and transmission electron microscopy. The spherical CuO nanoparticles were dispersed in sodium hexametaphosphate under sonication (25 kHz) to analyze the particle size distribution and UV absorption spectra. Using these absorption spectra, we further examined the CuO nanoparticle to explore the possibility of using them as a material for applications such as solar cell and textile production.

  6. Study of structural and optical properties of cupric oxide nanoparticles

    NASA Astrophysics Data System (ADS)

    Dhineshbabu, N. R.; Rajendran, V.; Nithyavathy, N.; Vetumperumal, R.

    2015-09-01

    In this study, cupric oxide (CuO) nanoparticles were synthesized via sonochemical method. The samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscope, and transmission electron microscopy. The spherical CuO nanoparticles were dispersed in sodium hexametaphosphate under sonication (25 kHz) to analyze the particle size distribution and UV absorption spectra. Using these absorption spectra, we further examined the CuO nanoparticle to explore the possibility of using them as a material for applications such as solar cell and textile production.

  7. Sodium alanate nanoparticles--linking size to hydrogen storage properties.

    PubMed

    Baldé, Cornelis P; Hereijgers, Bart P C; Bitter, Johannes H; de Jong, Krijn P

    2008-05-28

    Important limitations in the application of light metal hydrides for hydrogen storage are slow kinetics and poor reversibility. To alleviate these problems doping and ball-milling are commonly applied, for NaAlH 4 leading to particle sizes down to 150 nm. By wet-chemical synthesis we have prepared carbon nanofiber-supported NaAlH 4 with discrete particle size ranges of 1-10 microm, 19-30 nm, and 2-10 nm. The hydrogen desorption temperatures and activation energies decreased from 186 degrees C and 116 kJ.mol (-1) for the largest particles to 70 degrees C and 58 kJ.mol (-1) for the smallest particles. In addition, decreasing particle sizes lowered the pressures needed for reloading. This reported size-performance correlation for NaAlH 4 may guide hydrogen storage research for a wide range of nanostructured light (metal) hydrides. PMID:18459778

  8. The sodium/sulphur battery

    NASA Astrophysics Data System (ADS)

    Sudworth, J. L.

    1984-02-01

    Problems encountered in the design and development of a practical sodium/sulphur battery are reviewed and several solutions are offered. Consideration is given to the degradation of the solid electrolyte, beta alumina; problems with the sodium electrode associated with the sodium/beta alumina interface; and the loss of capacity identified with the sulphur electrode. Attention is also given to the search for corrosion-resistant materials for use as the current collector and to the geometry of the cell design. Criteria for a successful road vehicle battery are discussed.

  9. Sodium MRI: methods and applications.

    PubMed

    Madelin, Guillaume; Lee, Jae-Seung; Regatte, Ravinder R; Jerschow, Alexej

    2014-05-01

    Sodium NMR spectroscopy and MRI have become popular in recent years through the increased availability of high-field MRI scanners, advanced scanner hardware and improved methodology. Sodium MRI is being evaluated for stroke and tumor detection, for breast cancer studies, and for the assessment of osteoarthritis and muscle and kidney functions, to name just a few. In this article, we aim to present an up-to-date review of the theoretical background, the methodology, the challenges, limitations, and current and potential new applications of sodium MRI. PMID:24815363

  10. Sodium MRI: Methods and applications

    PubMed Central

    Madelin, Guillaume; Lee, Jae-Seung; Regatte, Ravinder R.; Jerschow, Alexej

    2014-01-01

    Sodium NMR spectroscopy and MRI have become popular in recent years through the increased availability of high-field MRI scanners, advanced scanner hardware and improved methodology. Sodium MRI is being evaluated for stroke and tumor detection, for breast cancer studies, and for the assessment of osteoarthritis and muscle and kidney functions, to name just a few. In this article, we aim to present an up-to-date review of the theoretical background, the methodology, the challenges and limitations, and current and potential new applications of sodium MRI. PMID:24815363

  11. Biomedical imaging of colorectal cancer by near infrared fluorescent nanoparticles.

    PubMed

    Tivony, Ran; Larush, Liraz; Sela-Tavor, Osnat; Magdassi, Shlomo

    2014-06-01

    In this paper we describe the preparation of novel Near Infrared (NIR) fluorescent nanoparticles for application in medical imaging of colorectal tumors. The nanoparticles are prepared by using only non-covalent binding processes of molecules which are approved for clinical use. The preparation process is based on the precipitation of a polycation, Eudragit-RS, followed by sequential adsorption of a blocking protein, sodium caseinate, NIR fluorescent dye, Indocyanine Green (ICG) and optionally, a targeting molecule, anti-CEA antibody. Fluorescence measurements have shown that these nanoparticles have higher resistance to photobleaching and higher quantum yield relatively to free ICG. Imaging experiments in orthotopic colorectal cancer mice models have shown that these fluorescent nanoparticles are capable of binding to LS174T human colon tumors in vivo with high specificity, even without the targeting molecule. These nanoparticles, composed of all FDA approved materials, open the way to clinical bioimaging and diagnostics of colon cancer. PMID:24749398

  12. Synthesis, characterization, optical and sensing property of manganese oxide nanoparticles

    SciTech Connect

    Manigandan, R.; Suresh, R.; Giribabu, K.; Narayanan, V.; Vijayalakshmi, L.; Stephen, A.

    2014-01-28

    Manganese oxide nanoparticles were prepared by thermal decomposition of manganese oxalate. Manganese oxalate was synthesized by reacting 1:1 mole ratio of manganese acetate and ammonium oxalate along with sodium dodecyl sulfate (SDS). The structural characterization of manganese oxalate and manganese oxide nanoparticles was analyzed by XRD. The XRD spectrum confirms the crystal structure of the manganese oxide and manganese oxalate. In addition, the average grain size, lattice parameter values were also calculated using XRD spectrum. Moreover, the diffraction peaks were broadened due to the smaller size of the particle. The band gap of manganese oxide was calculated from optical absorption, which was carried out by DRS UV-Visible spectroscopy. The morphology of manganese oxide nanoparticles was analyzed by SEM images. The FT-IR analysis confirms the formation of the manganese oxide from manganese oxalate nanoparticles. The electrochemical sensing behavior of manganese oxide nanoparticles were investigated using hydrogen peroxide by cyclic voltammetry.

  13. CALANDRIA TYPE SODIUM GRAPHITE REACTOR

    DOEpatents

    Peterson, R.M.; Mahlmeister, J.E.; Vaughn, N.E.; Sanders, W.J.; Williams, A.C.

    1964-02-11

    A sodium graphite power reactor in which the unclad graphite moderator and fuel elements are contained within a core tank is described. The core tank is submersed in sodium within the reactor vessel. Extending longitudinally through the core thnk are process tubes with fuel elements positioned therein. A bellows sealing means allows axial expansion and construction of the tubes. Within the core tank, a leakage plenum is located below the graphite, and above the graphite is a gas space. A vent line regulates the gas pressure in the space, and another line removes sodium from the plenum. The sodium coolant flows from the lower reactor vessel through the annular space between the fuel elements and process tubes and out into the reactor vessel space above the core tank. From there, the heated coolant is drawn off through an outlet line and sent to the heat exchange. (AEC)

  14. [Hypolactatemic effect of sodium difluoroacetate].

    PubMed

    Dalstein, J M; Ribes, G; Campo, P; Loubatières-Mariani, M M

    1980-01-01

    In the anesthetized rat, the intraperitoneal injection of 40 mg/kg sodium difluoroacetate (DFA), an activator of the pyruvate dehydrogenase, counteracted the hyperlactatemia induced by a high dose of phenformin (40 mg/kg) injected concomitantly. In the normal conscious dog, the administration of 150 mg/kg by gastric intubation decreased the blood lactate and pyruvate levels; however, this effect was less marked than that produced by the same dose of sodium dichloroacetate (DCA). PMID:6449260

  15. Sodium and water: an overview.

    PubMed

    Papper, S

    1976-01-01

    The renal regulation of sodium is intertwined with the extracellular fluid volume (ECFV). Most adjustments in sodium elimination in man are accomplished via alterations in tubular reabsorption. The latter is sensitive to change in ECFV. An expanded ECFV results in less reabsorption and more excretion of sodium, and a contracted ECFV has the converse effect. There are direct and indirect mechanisms whereby ECFV influences sodium reabsorption. Patients with nephrotic syndrome, heart failure, and cirrhosis "behave" physiologically as normal individuals with a contracted ECFV. Water balance is normally determined by intake and losses in sweat which is always hypoosmotic to plasma, by evaporation from skin and lungs, and through renal excretion. The major factors that determine the ability to concentrate the urine are (1) the establishment of a concentrated environment around the collecting ducts, and (2) the elaboration and effects on the kidney of antidiuretic hormone. The evaluation of a patient with abnormalities of sodium and water rests initially and largely on clinical information. The clinical setting provides clues to anticipating, preventing, and interpreting distortions of body sodium and water. The laboratory can detect an abnormality, confirm or refute clinical assessment, and assist in the quantitative aspects of treatment and its efficacy. PMID:961714

  16. Are Reductions in Population Sodium Intake Achievable?

    PubMed Central

    Levings, Jessica L.; Cogswell, Mary E.; Gunn, Janelle Peralez

    2014-01-01

    The vast majority of Americans consume too much sodium, primarily from packaged and restaurant foods. The evidence linking sodium intake with direct health outcomes indicates a positive relationship between higher levels of sodium intake and cardiovascular disease risk, consistent with the relationship between sodium intake and blood pressure. Despite communication and educational efforts focused on lowering sodium intake over the last three decades data suggest average US sodium intake has remained remarkably elevated, leading some to argue that current sodium guidelines are unattainable. The IOM in 2010 recommended gradual reductions in the sodium content of packaged and restaurant foods as a primary strategy to reduce US sodium intake, and research since that time suggests gradual, downward shifts in mean population sodium intake are achievable and can move the population toward current sodium intake guidelines. The current paper reviews recent evidence indicating: (1) significant reductions in mean population sodium intake can be achieved with gradual sodium reduction in the food supply, (2) gradual sodium reduction in certain cases can be achieved without a noticeable change in taste or consumption of specific products, and (3) lowering mean population sodium intake can move us toward meeting the current individual guidelines for sodium intake. PMID:25325254

  17. 21 CFR 184.1763 - Sodium hydroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... hydroxide is prepared commercially by the electrolysis of sodium chloride solution and also by reacting... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium hydroxide. 184.1763 Section 184.1763 Food... GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg. No. 1310-73-2) is also known...

  18. 21 CFR 184.1724 - Sodium alginate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium alginate. 184.1724 Section 184.1724 Food... Specific Substances Affirmed as GRAS § 184.1724 Sodium alginate. (a) Sodium alginate (CAS Reg. No. 9005-38-3) is the sodium salt of alginic acid, a natural polyuronide constituent of certain brown...

  19. 21 CFR 172.170 - Sodium nitrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium nitrate. 172.170 Section 172.170 Food and... Preservatives § 172.170 Sodium nitrate. The food additive sodium nitrate may be safely used in or on specified... follows: (1) As a preservative and color fixative, with or without sodium nitrite, in smoked,...

  20. 21 CFR 173.73 - Sodium polyacrylate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium polyacrylate. 173.73 Section 173.73 Food... Polymer Substances and Polymer Adjuvants for Food Treatment § 173.73 Sodium polyacrylate. Sodium... the polyacrylic acid with an aqueous sodium hydroxide solution. As determined by a method...

  1. 21 CFR 172.175 - Sodium nitrite.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium nitrite. 172.175 Section 172.175 Food and... Preservatives § 172.175 Sodium nitrite. The food additive sodium nitrite may be safely used in or on specified... follows: (1) As a color fixative in smoked cured tunafish products so that the level of sodium...

  2. 21 CFR 582.2727 - Sodium aluminosilicate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sodium aluminosilicate. 582.2727 Section 582.2727 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Sodium aluminosilicate. (a) Product. Sodium aluminosilicate (sodium silicoaluminate). (b) Tolerance....

  3. 21 CFR 182.2727 - Sodium aluminosilicate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium aluminosilicate. 182.2727 Section 182.2727 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Sodium aluminosilicate. (a) Product. Sodium aluminosilicate (sodium silicoaluminate). (b) Tolerance....

  4. 21 CFR 172.175 - Sodium nitrite.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium nitrite. 172.175 Section 172.175 Food and... Preservatives § 172.175 Sodium nitrite. The food additive sodium nitrite may be safely used in or on specified... follows: (1) As a color fixative in smoked cured tunafish products so that the level of sodium...

  5. 21 CFR 186.1750 - Sodium chlorite.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium chlorite. 186.1750 Section 186.1750 Food... of Specific Substances Affirmed as GRAS § 186.1750 Sodium chlorite. (a) Sodium chlorite (NaCLO2, CAS... passing chlorine dioxide into a solution of sodium hydroxide and hydrogen peroxide. (b) the ingredient...

  6. 21 CFR 182.2727 - Sodium aluminosilicate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium aluminosilicate. 182.2727 Section 182.2727 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Sodium aluminosilicate. (a) Product. Sodium aluminosilicate (sodium silicoaluminate). (b) Tolerance....

  7. 21 CFR 573.700 - Sodium nitrite.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sodium nitrite. 573.700 Section 573.700 Food and... Listing § 573.700 Sodium nitrite. Sodium nitrite may be safely used in canned pet food containing meat and... byproducts so that the level of sodium nitrite does not exceed 20 parts per million. (b) To assure safe...

  8. 21 CFR 573.700 - Sodium nitrite.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Sodium nitrite. 573.700 Section 573.700 Food and... Listing § 573.700 Sodium nitrite. Sodium nitrite may be safely used in canned pet food containing meat and... byproducts so that the level of sodium nitrite does not exceed 20 parts per million. (b) To assure safe...

  9. 21 CFR 186.1750 - Sodium chlorite.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium chlorite. 186.1750 Section 186.1750 Food... of Specific Substances Affirmed as GRAS § 186.1750 Sodium chlorite. (a) Sodium chlorite (NaCLO2, CAS... passing chlorine dioxide into a solution of sodium hydroxide and hydrogen peroxide. (b) the ingredient...

  10. 21 CFR 182.2727 - Sodium aluminosilicate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium aluminosilicate. 182.2727 Section 182.2727 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Sodium aluminosilicate. (a) Product. Sodium aluminosilicate (sodium silicoaluminate). (b) Tolerance....

  11. 21 CFR 184.1724 - Sodium alginate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium alginate. 184.1724 Section 184.1724 Food... Specific Substances Affirmed as GRAS § 184.1724 Sodium alginate. (a) Sodium alginate (CAS Reg. No. 9005-38-3) is the sodium salt of alginic acid, a natural polyuronide constituent of certain brown...

  12. 21 CFR 172.170 - Sodium nitrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium nitrate. 172.170 Section 172.170 Food and... Preservatives § 172.170 Sodium nitrate. The food additive sodium nitrate may be safely used in or on specified... follows: (1) As a preservative and color fixative, with or without sodium nitrite, in smoked,...

  13. 21 CFR 184.1792 - Sodium sesquicarbonate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium sesquicarbonate. 184.1792 Section 184.1792... Listing of Specific Substances Affirmed as GRAS § 184.1792 Sodium sesquicarbonate. (a) Sodium... naturally occurring impure sodium sesquicarbonate. (b) The ingredient meets the specifications of the...

  14. 21 CFR 582.2727 - Sodium aluminosilicate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Sodium aluminosilicate. 582.2727 Section 582.2727 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Sodium aluminosilicate. (a) Product. Sodium aluminosilicate (sodium silicoaluminate). (b) Tolerance....

  15. 21 CFR 172.175 - Sodium nitrite.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium nitrite. 172.175 Section 172.175 Food and... Preservatives § 172.175 Sodium nitrite. The food additive sodium nitrite may be safely used in or on specified... follows: (1) As a color fixative in smoked cured tunafish products so that the level of sodium...

  16. 21 CFR 173.73 - Sodium polyacrylate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium polyacrylate. 173.73 Section 173.73 Food... Polymer Substances and Polymer Adjuvants for Food Treatment § 173.73 Sodium polyacrylate. Sodium... the polyacrylic acid with an aqueous sodium hydroxide solution. As determined by a method...

  17. 21 CFR 182.2727 - Sodium aluminosilicate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium aluminosilicate. 182.2727 Section 182.2727 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Sodium aluminosilicate. (a) Product. Sodium aluminosilicate (sodium silicoaluminate). (b) Tolerance....

  18. 21 CFR 582.1745 - Sodium carboxymethylcellulose.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sodium carboxymethylcellulose. 582.1745 Section... Food Additives § 582.1745 Sodium carboxymethylcellulose. (a) Product. Sodium carboxymethyl- cellulose is the sodium salt of carboxymethylcellulose not less than 99.5 percent on a dry-weight basis,...

  19. 21 CFR 573.700 - Sodium nitrite.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sodium nitrite. 573.700 Section 573.700 Food and... Listing § 573.700 Sodium nitrite. Sodium nitrite may be safely used in canned pet food containing meat and... byproducts so that the level of sodium nitrite does not exceed 20 parts per million. (b) To assure safe...

  20. 21 CFR 186.1750 - Sodium chlorite.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium chlorite. 186.1750 Section 186.1750 Food... of Specific Substances Affirmed as GRAS § 186.1750 Sodium chlorite. (a) Sodium chlorite (NaCLO2, CAS... passing chlorine dioxide into a solution of sodium hydroxide and hydrogen peroxide. (b) the ingredient...

  1. 21 CFR 582.1745 - Sodium carboxymethylcellulose.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sodium carboxymethylcellulose. 582.1745 Section... Food Additives § 582.1745 Sodium carboxymethylcellulose. (a) Product. Sodium carboxymethyl- cellulose is the sodium salt of carboxymethylcellulose not less than 99.5 percent on a dry-weight basis,...

  2. 21 CFR 184.1792 - Sodium sesquicarbonate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium sesquicarbonate. 184.1792 Section 184.1792... GRAS § 184.1792 Sodium sesquicarbonate. (a) Sodium sesquicarbonate (Na2CO3·NaHCO3·2H2O, CAS Reg. No..., centrifugation, and drying; (2) double refining of trona ore, a naturally occurring impure sodium...

  3. 21 CFR 186.1797 - Sodium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium sulfate. 186.1797 Section 186.1797 Food and... Substances Affirmed as GRAS § 186.1797 Sodium sulfate. (a) Sodium sulfate (Na2SO4, CAS Reg. No. 7757-82-6... crystalline powder. It is prepared by the neutralization of sulfuric acid with sodium hydroxide. (b)...

  4. 21 CFR 184.1792 - Sodium sesquicarbonate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium sesquicarbonate. 184.1792 Section 184.1792... Listing of Specific Substances Affirmed as GRAS § 184.1792 Sodium sesquicarbonate. (a) Sodium... naturally occurring impure sodium sesquicarbonate. (b) The ingredient meets the specifications of the...

  5. 21 CFR 173.73 - Sodium polyacrylate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium polyacrylate. 173.73 Section 173.73 Food... for Food Treatment § 173.73 Sodium polyacrylate. Sodium polyacrylate (CAS Reg. No. 9003-04-7) may be... aqueous sodium hydroxide solution. As determined by a method entitled “Determination of Weight Average...

  6. 21 CFR 172.170 - Sodium nitrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium nitrate. 172.170 Section 172.170 Food and... Preservatives § 172.170 Sodium nitrate. The food additive sodium nitrate may be safely used in or on specified... follows: (1) As a preservative and color fixative, with or without sodium nitrite, in smoked,...

  7. 21 CFR 582.2727 - Sodium aluminosilicate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sodium aluminosilicate. 582.2727 Section 582.2727 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Sodium aluminosilicate. (a) Product. Sodium aluminosilicate (sodium silicoaluminate). (b) Tolerance....

  8. 21 CFR 582.1745 - Sodium carboxymethylcellulose.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sodium carboxymethylcellulose. 582.1745 Section... Food Additives § 582.1745 Sodium carboxymethylcellulose. (a) Product. Sodium carboxymethyl- cellulose is the sodium salt of carboxymethylcellulose not less than 99.5 percent on a dry-weight basis,...

  9. 21 CFR 172.175 - Sodium nitrite.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium nitrite. 172.175 Section 172.175 Food and... Preservatives § 172.175 Sodium nitrite. The food additive sodium nitrite may be safely used in or on specified... follows: (1) As a color fixative in smoked cured tunafish products so that the level of sodium...

  10. 21 CFR 186.1797 - Sodium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium sulfate. 186.1797 Section 186.1797 Food and... Substances Affirmed as GRAS § 186.1797 Sodium sulfate. (a) Sodium sulfate (Na2SO4, CAS Reg. No. 7757-82-6... crystalline powder. It is prepared by the neutralization of sulfuric acid with sodium hydroxide. (b)...

  11. 21 CFR 182.2727 - Sodium aluminosilicate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium aluminosilicate. 182.2727 Section 182.2727...) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Anticaking Agents § 182.2727 Sodium aluminosilicate. (a) Product. Sodium aluminosilicate (sodium silicoaluminate). (b) Tolerance. This substance is generally recognized...

  12. 21 CFR 186.1797 - Sodium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium sulfate. 186.1797 Section 186.1797 Food and... Substances Affirmed as GRAS § 186.1797 Sodium sulfate. (a) Sodium sulfate (Na2SO4, CAS Reg. No. 7757-82-6... crystalline powder. It is prepared by the neutralization of sulfuric acid with sodium hydroxide. (b)...

  13. 21 CFR 186.1797 - Sodium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium sulfate. 186.1797 Section 186.1797 Food and....1797 Sodium sulfate. (a) Sodium sulfate (Na2SO4, CAS Reg. No. 7757-82-6), also known as Glauber's salt... by the neutralization of sulfuric acid with sodium hydroxide. (b) The ingredient is used as...

  14. 21 CFR 582.1745 - Sodium carboxymethylcellulose.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium carboxymethylcellulose. 582.1745 Section... Food Additives § 582.1745 Sodium carboxymethylcellulose. (a) Product. Sodium carboxymethyl- cellulose is the sodium salt of carboxymethylcellulose not less than 99.5 percent on a dry-weight basis,...

  15. 21 CFR 173.73 - Sodium polyacrylate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium polyacrylate. 173.73 Section 173.73 Food and... Substances and Polymer Adjuvants for Food Treatment § 173.73 Sodium polyacrylate. Sodium polyacrylate (CAS... polyacrylic acid with an aqueous sodium hydroxide solution. As determined by a method entitled...

  16. 21 CFR 186.1750 - Sodium chlorite.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium chlorite. 186.1750 Section 186.1750 Food... GRAS § 186.1750 Sodium chlorite. (a) Sodium chlorite (NaCLO2, CAS Reg. No. 7758-19-2) exists as... solution of sodium hydroxide and hydrogen peroxide. (b) the ingredient is used at levels from 125 to...

  17. 21 CFR 582.2727 - Sodium aluminosilicate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sodium aluminosilicate. 582.2727 Section 582.2727 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Sodium aluminosilicate. (a) Product. Sodium aluminosilicate (sodium silicoaluminate). (b) Tolerance....

  18. 21 CFR 172.170 - Sodium nitrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium nitrate. 172.170 Section 172.170 Food and... Preservatives § 172.170 Sodium nitrate. The food additive sodium nitrate may be safely used in or on specified... follows: (1) As a preservative and color fixative, with or without sodium nitrite, in smoked,...

  19. 21 CFR 582.2727 - Sodium aluminosilicate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium aluminosilicate. 582.2727 Section 582.2727 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Sodium aluminosilicate. (a) Product. Sodium aluminosilicate (sodium silicoaluminate). (b) Tolerance....

  20. 21 CFR 582.1745 - Sodium carboxymethylcellulose.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Sodium carboxymethylcellulose. 582.1745 Section... Food Additives § 582.1745 Sodium carboxymethylcellulose. (a) Product. Sodium carboxymethyl- cellulose is the sodium salt of carboxymethylcellulose not less than 99.5 percent on a dry-weight basis,...

  1. 21 CFR 173.73 - Sodium polyacrylate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium polyacrylate. 173.73 Section 173.73 Food... Polymer Substances and Polymer Adjuvants for Food Treatment § 173.73 Sodium polyacrylate. Sodium... the polyacrylic acid with an aqueous sodium hydroxide solution. As determined by a method...

  2. 21 CFR 184.1724 - Sodium alginate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium alginate. 184.1724 Section 184.1724 Food... Specific Substances Affirmed as GRAS § 184.1724 Sodium alginate. (a) Sodium alginate (CAS Reg. No. 9005-38-3) is the sodium salt of alginic acid, a natural polyuronide constituent of certain brown...

  3. 21 CFR 184.1792 - Sodium sesquicarbonate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium sesquicarbonate. 184.1792 Section 184.1792... Listing of Specific Substances Affirmed as GRAS § 184.1792 Sodium sesquicarbonate. (a) Sodium... naturally occurring impure sodium sesquicarbonate. (b) The ingredient meets the specifications of the...

  4. 21 CFR 184.1792 - Sodium sesquicarbonate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium sesquicarbonate. 184.1792 Section 184.1792... Listing of Specific Substances Affirmed as GRAS § 184.1792 Sodium sesquicarbonate. (a) Sodium... naturally occurring impure sodium sesquicarbonate. (b) The ingredient meets the specifications of the...

  5. 21 CFR 186.1797 - Sodium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium sulfate. 186.1797 Section 186.1797 Food and... Substances Affirmed as GRAS § 186.1797 Sodium sulfate. (a) Sodium sulfate (Na2SO4, CAS Reg. No. 7757-82-6... crystalline powder. It is prepared by the neutralization of sulfuric acid with sodium hydroxide. (b)...

  6. 21 CFR 184.1768 - Sodium lactate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ....1768 Sodium lactate. (a) Sodium lactate (C3H5O3Na, CAS Reg. No. 72-17-3) is the sodium salt of lactic acid. It is prepared commercially by the neutralization of lactic acid with sodium hydroxide. (b)...

  7. Na2Cu7(SeO3)4O2Cl4: a selenite chloride compound with Cu7 units showing spin-frustration and a magnetization plateau.

    PubMed

    Tang, Yingying; Guo, Wenbin; Zhang, Suyun; Xiang, Hongping; Cui, Meiyan; He, Zhangzhen

    2016-05-17

    A selenite chloride, Na2Cu7(SeO3)4O2Cl4 (), was prepared via a conventional hydrothermal method. Na2Cu7(SeO3)4O2Cl4 crystallizes in the triclinic space group P1[combining macron] and features an isolated reverse triangular dipyramid Cu7, which is assembled with two corner-shared Cu4 tetrahedral units. Magnetic measurements suggest that shows the spin-frustration effect with antiferromagnetic ordering at ∼5 K, while an unusual magnetization plateau is observed at an applied field of >4 T. PMID:27159358

  8. Effect of silver on the shape of palladium nanoparticles

    NASA Astrophysics Data System (ADS)

    Gupta, Dikshita; Barman, P. B.; Hazra, S. K.

    2016-05-01

    We report a facile route to prepare palladium-silver nanoparticles at considerably low temperature. First the controlled synthesis of palladium nanoparticles was performed via reduction of sodium tetrachloropalladate (II) in ethylene glycol in the presence of PVP(polyvinylpyrrolidone) as capping agent. The reaction was carried out at three different temperatures-80°C, 100°C and 120°C for one hour. Short reaction time and low synthesis temperature adds advantage to this method over others. Formed palladium nanoparticles were nearly spherical with the average particle size of 7.5±0.5 nm, 9.5±0.5 nm and 10.5±0.5 nm at 80°C, 100°C and 120°C respectively. Secondly, the palladium-silver nanoparticles were prepared by the simultaneous reduction of palladium and silver from their respective precursors in ethylene glycol at 100°C (optimized temperature). The shape and size distribution was studied by TEM (Transmission Electron Microscopy). The role of silver in transforming the shape of palladium nanoparticles from spherical to triangular has been discussed. Spherical symmetry of palladium nanoparticles is disturbed by the interaction of silver ions on the crystal facets of palladium nanoparticles. From UV-vis spectra, the absorption maxima of palladium nanoparticles at 205 nm and absorption maxima of palladium-silver nanoparticles at 272 nm revealed the partial evidence of their formation.

  9. Thermo-optical properties of gold nanoparticles in colloidal systems

    NASA Astrophysics Data System (ADS)

    Ortega, M. A.; Rodriguez, L.; Castillo, J.; Piscitelli, V.; Fernandez, A.; Echevarria, L.

    2008-10-01

    In this work, we report the thermo-optical properties of nanoparticles in colloidal suspensions. Spherical gold nanoparticles obtained by laser ablation in condensed media were characterized using thermal lens spectroscopy pumping at 532 nm with a 10 ns pulse laser-Nd-YAG system. The obtained nanoparticles were stabilized in the time by surfactants (sodium dodecyl sulfate or SDS) in water with different molar concentrations. The morphology and size of the gold nanoparticles were determined by transmission electron microscopy (TEM) and UV-visible techniques. The plasmonic resonance bands in gold nanoparticles are responsible for the light optical absorption, and the positions of the absorption maximum and bandwidth in the UV-visible spectra are given by the morphological characteristics of these systems. The thermo-optical constants such as thermal diffusion, thermal diffusivity, and (dn/dT) are functions of the nanoparticle sizes and the dielectric function of the media. For these reasons, the thermal lens (TL) signal is also dependent on nanoparticle sizes. An analysis of the TL signal of the nanoparticles reveals the existence of an inverse dependence between the thermo-optical functions and the size. This methodology can be used in order to evaluate these systems and characterize nanoparticles in different media. These results are expected to have an impact in bioimaging, biosensors, and other technological applications such as cooling systems.

  10. Facile synthesis of efficient photocatalytic tantalum nitride nanoparticles

    SciTech Connect

    Wang, Zheng; Wang, Jiangting; Hou, Jungang; Huang, Kai; Jiao, Shuqiang; Zhu, Hongmin

    2012-11-15

    Graphical abstract: Tantalum nitride nanoparticles as a visible-light-driven photocatalyst prepared by a novel homogeneously chemical reduction of tantalum pentachloride using sodium in liquid ammonia and the morphologies, visible-light photocatalytic properties and stability of tantalum nitride nanoparticles were investigated. Highlights: ► Tantalum nitride nanoparticles have been prepared by a homogeneously chemical reduction. ► The crystal structure of tantalum nitride was determined by Rietveld refinement and XRD patterns. ► The Tantalum nitride nanoparticle size was in the range of 20–50 nm. ► Much high photocatalytic activities of Ta{sub 3}N{sub 5} nanoparticles were obtained under visible-light irradiation. -- Abstract: Tantalum nitride nanoparticles, as visible-light photocatalysts were synthesized by a two-step homogeneously chemical reduction without any polymers and templates. The well-crystallized Ta{sub 3}N{sub 5} nanoparticles with a range of 20–50 nm in size have been characterized by a number of techniques, such as XRD, XPS, SEM, TEM, BET and UV–Vis spectrum. Most importantly, the Ta{sub 3}N{sub 5} nanoparticles with good stability exhibited higher photooxidation activities in the water splitting and degradation of methylene blue under visible light irradiation than bulk Ta{sub 3}N{sub 5} particles and commercial P25 TiO{sub 2}, demonstrating that Ta{sub 3}N{sub 5} nanoparticle is a promising candidate as a visible-light photocatalyst.

  11. Template based synthesis of gold nanotubes using biologically synthesized gold nanoparticles.

    PubMed

    Ballabh, R; Nara, S

    2015-12-01

    Reliable experimental protocols using green technologies to synthesize metallic nanostructures widen their applications, both biological as well as biomedical. Here, we describe a method for synthesizing gold nanotubes using biologically synthesized gold nanoparticles in a template based approach. E. coli DH5α was used as bionanofactory to synthesize gold nanoparticles. These nanoparticles were then deposited on sodium sulfate (Na2SO4) nanowires which were employed as sacrificial template for gold nanotube (Au-NT) formation. The gold nanoparticles, sodium sulphate nanowires and gold nanotubes were appropriately characterized using transmission electron microscopy. The TEM results showed that the average diameter of gold nanotubes was 72 nm and length up to 4-7 μm. The method discussed herein is better than other reported conventional chemical synthesis approaches as it uses biologically synthesized gold nanoparticles, and does not employ any harsh conditions/solvents for template removal which makes it a clean and ecofriendly method. PMID:26742328

  12. Insect sodium channels and insecticide resistance

    PubMed Central

    2011-01-01

    Voltage-gated sodium channels are essential for the generation and propagation of action potentials (i.e., electrical impulses) in excitable cells. Although most of our knowledge about sodium channels is derived from decades of studies of mammalian isoforms, research on insect sodium channels is revealing both common and unique aspects of sodium channel biology. In particular, our understanding of the molecular dynamics and pharmacology of insect sodium channels has advanced greatly in recent years, thanks to successful functional expression of insect sodium channels in Xenopus oocytes and intensive efforts to elucidate the molecular basis of insect resistance to insecticides that target sodium channels. In this review, I discuss recent literature on insect sodium channels with emphases on the prominent role of alternative splicing and RNA editing in the generation of functionally diverse sodium channels in insects and the current understanding of the interactions between insect sodium channels and insecticides. PMID:17206406

  13. Treprostinil sodium Pharmacia.

    PubMed

    Chattaraj, Sarat C

    2002-04-01

    United Therapeutics Corp (UTC) is developing treprostinil sodium (Remodulin, UT-15), a stable structural analog of prostacyclin, for the potential treatment of primary pulmonary (arterial) hypertension (PAH), peripheral vascular disease (PVD) and other cardiovascular conditions [327593], including critical limb ischemia (CLI) [412483]. In August 2000, UTC submitted the initial, non-clinical sections of an NDA for the treatment of pulmonary hypertension [378906]. Treprostinil, which had previously been designated as an Orphan Drug, was also awarded Priority Review status by the US FDA in October 2000 [385864], [386271]. In December 2000, UTC agreed with the FDA that the NDA for treprostinil did not need to be presented to the Cardiovascular and Renal Drugs Advisory Committee, which was expected to allow UTC and the FDA to work towards the 6-month Priority Review timeline [393888]. On August 9, 2001, the advisory committee recommended approval of treprostinil and UTC refiled the NDA on the same day [418682]. In February 2002, the FDA issued an approvable letter for treprostinil injection for the treatment of PAH. The FDA proposed drug labeling for PAH consistent with the treatment of both primary and secondary pulmonary hypertension in patients with New York Heart Association (NYHA) Class II-IV symptoms. The approvable letter also stated that the FDA intended to approve treprostinil with a requirement that UTC subsequently conduct a post-marketing controlled clinical trial to verify and further describe the drug's clinical benefit [439278]. In February 2001, UTC submitted a marketing authorization application (MAA) in France for approval of treprostinil for the treatment of PAH. Upon approval of the MAA, UTC planned to file for Mutual Recognition in other European countries and was also preparing similar submissions to non-European countries [391986], [397958]. By early 2001, phase II trials of treprostinil for the treatment of CLI were underway [412483]. In March

  14. 21 CFR 522.2444b - Sodium thiopental, sodium pentobarbital for injection.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sodium thiopental, sodium pentobarbital for... FORM NEW ANIMAL DRUGS § 522.2444b Sodium thiopental, sodium pentobarbital for injection. (a) Specifications. Each gram of the drug contains 750 milligrams of sodium thiopental and 250 milligrams of...

  15. 21 CFR 522.2444b - Sodium thiopental, sodium pentobarbital for injection.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sodium thiopental, sodium pentobarbital for... FORM NEW ANIMAL DRUGS § 522.2444b Sodium thiopental, sodium pentobarbital for injection. (a) Specifications. Each gram of the drug contains 750 milligrams of sodium thiopental and 250 milligrams of...

  16. 21 CFR 522.2444b - Sodium thiopental, sodium pentobarbital for injection.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sodium thiopental, sodium pentobarbital for... FORM NEW ANIMAL DRUGS § 522.2444b Sodium thiopental, sodium pentobarbital for injection. (a) Specifications. Each gram of the drug contains 750 milligrams of sodium thiopental and 250 milligrams of...

  17. 21 CFR 522.2444b - Sodium thiopental, sodium pentobarbital for injection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium thiopental, sodium pentobarbital for... FORM NEW ANIMAL DRUGS § 522.2444b Sodium thiopental, sodium pentobarbital for injection. (a) Specifications. Each gram of the drug contains 750 milligrams of sodium thiopental and 250 milligrams of...

  18. 49 CFR 173.189 - Batteries containing sodium or cells containing sodium.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Batteries containing sodium or cells containing... Than Class 1 and Class 7 § 173.189 Batteries containing sodium or cells containing sodium. (a) Batteries and cells may not contain any hazardous material other than sodium, sulfur or sodium compounds...

  19. 49 CFR 173.189 - Batteries containing sodium or cells containing sodium.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Batteries containing sodium or cells containing... Than Class 1 and Class 7 § 173.189 Batteries containing sodium or cells containing sodium. (a) Batteries and cells may not contain any hazardous material other than sodium, sulfur or sodium compounds...

  20. 49 CFR 173.189 - Batteries containing sodium or cells containing sodium.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Batteries containing sodium or cells containing... Than Class 1 and Class 7 § 173.189 Batteries containing sodium or cells containing sodium. (a) Batteries and cells may not contain any hazardous material other than sodium, sulfur or sodium compounds...

  1. 49 CFR 173.189 - Batteries containing sodium or cells containing sodium.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Batteries containing sodium or cells containing... Than Class 1 and Class 7 § 173.189 Batteries containing sodium or cells containing sodium. (a) Batteries and cells may not contain any hazardous material other than sodium, sulfur or sodium compounds...

  2. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... sodium sulfate and sodium bicarbonate. (b) The ingredient meets the specifications of the Food Chemicals... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium acetate. 184.1721 Section 184.1721 Food and... Substances Affirmed as GRAS § 184.1721 Sodium acetate. (a) Sodium acetate (C2H3O2Na, CAS Reg. No. 127-09-3...

  3. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... sodium sulfate and sodium bicarbonate. (b) The ingredient meets the specifications of the Food Chemicals... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium acetate. 184.1721 Section 184.1721 Food and... Substances Affirmed as GRAS § 184.1721 Sodium acetate. (a) Sodium acetate (C2H3O2Na, CAS Reg. No. 127-09-3...

  4. 21 CFR 184.1721 - Sodium acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... sodium sulfate and sodium bicarbonate. (b) The ingredient meets the specifications of the Food Chemicals... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium acetate. 184.1721 Section 184.1721 Food and... Substances Affirmed as GRAS § 184.1721 Sodium acetate. (a) Sodium acetate (C2H3O2Na, CAS Reg. No. 127-09-3...

  5. Sodium Velocity Maps on Mercury

    NASA Technical Reports Server (NTRS)

    Potter, A. E.; Killen, R. M.

    2011-01-01

    The objective of the current work was to measure two-dimensional maps of sodium velocities on the Mercury surface and examine the maps for evidence of sources or sinks of sodium on the surface. The McMath-Pierce Solar Telescope and the Stellar Spectrograph were used to measure Mercury spectra that were sampled at 7 milliAngstrom intervals. Observations were made each day during the period October 5-9, 2010. The dawn terminator was in view during that time. The velocity shift of the centroid of the Mercury emission line was measured relative to the solar sodium Fraunhofer line corrected for radial velocity of the Earth. The difference between the observed and calculated velocity shift was taken to be the velocity vector of the sodium relative to Earth. For each position of the spectrograph slit, a line of velocities across the planet was measured. Then, the spectrograph slit was stepped over the surface of Mercury at 1 arc second intervals. The position of Mercury was stabilized by an adaptive optics system. The collection of lines were assembled into an images of surface reflection, sodium emission intensities, and Earthward velocities over the surface of Mercury. The velocity map shows patches of higher velocity in the southern hemisphere, suggesting the existence of sodium sources there. The peak earthward velocity occurs in the equatorial region, and extends to the terminator. Since this was a dawn terminator, this might be an indication of dawn evaporation of sodium. Leblanc et al. (2008) have published a velocity map that is similar.

  6. Salt-Driven Deposition of Thermoresponsive Polymer-Coated Metal Nanoparticles on Solid Substrates.

    PubMed

    Zhang, Zhiyue; Maji, Samarendra; da Fonseca Antunes, André B; De Rycke, Riet; Hoogenboom, Richard; De Geest, Bruno G

    2016-06-13

    Here we report on a simple, generally applicable method for depositing metal nanoparticles on a wide variety of solid surfaces under all aqueous conditions. Noble-metal nanoparticles obtained by citrate reduction followed by coating with thermoresponsive polymers spontaneously form a monolayer-like structure on a wide variety of substrates in presence of sodium chloride whereas this phenomenon does not occur in salt-free medium. Interestingly, this phenomenon occurs below the cloud point temperature of the polymers and we hypothesize that salt ion-induced screening of electrostatic charges on the nanoparticle surface entropically favors hydrophobic association between the polymer-coated nanoparticles and a hydrophobic substrate. PMID:27142455

  7. Synthesis of Copper/Copper-Oxide Nanoparticles: Optical and Structural Characterizations

    SciTech Connect

    Swarnkar, R. K.; Singh, S. C.; Gopal, R.

    2009-06-29

    In the present study, we have synthesized copper/copper-oxide nanoparticles by laser ablation of copper metal in aqueous solution of sodium dodecyl sulfate. The focused output of 1064 nm wavelength of pulsed Nd:YAG laser is used for ablation. The synthesized nanoparticles are characterized by UV-visible absorption, X-ray diffraction, transmission electron microscopy and Raman spectroscopy techniques. The synthesis of copper/copper oxide nanoparticles are confirmed by XRD and Raman studies. The possible mechanism of nanoparticle formation is also discussed.

  8. Nano zinc oxide-sodium alginate antibacterial cellulose fibres.

    PubMed

    Varaprasad, Kokkarachedu; Raghavendra, Gownolla Malegowd; Jayaramudu, Tippabattini; Seo, Jongchul

    2016-01-01

    In the present study, antibacterial cellulose fibres were successfully fabricated by a simple and cost-effective procedure by utilizing nano zinc oxide. The possible nano zinc oxide was successfully synthesized by precipitation technique and then impregnated effectively over cellulose fibres through sodium alginate matrix. XRD analysis revealed the 'rod-like' shape alignment of zinc oxide with an interplanar d-spacing of 0.246nm corresponding to the (101) planes of the hexagonal wurtzite structure. TEM analysis confirmed the nano dimension of the synthesized zinc oxide nanoparticles. The presence of nano zinc oxide over cellulose fibres was evident from the SEM-EDS experiments. FTIR and TGA studies exhibited their effective bonding interaction. The tensile stress-strain curves data indicated the feasibility of the fabricated fibres for longer duration utility without any significant damage or breakage. The antibacterial studies against Escherichia coli revealed the excellent bacterial devastation property. Further, it was observed that when all the parameters remained constant, the variation of sodium alginate concentration showed impact in devastating the E. coli. In overall, the fabricated nano zinc oxide-sodium alginate cellulose fibres can be effectively utilized as antibacterial fibres for biomedical applications. PMID:26453887

  9. Electrochemical synthesis and characterization of zinc oxalate nanoparticles

    SciTech Connect

    Shamsipur, Mojtaba; Roushani, Mahmoud; Pourmortazavi, Seied Mahdi

    2013-03-15

    Highlights: ► Synthesis of zinc oxalate nanoparticles via electrolysis of a zinc plate anode in sodium oxalate solutions. ► Design of a Taguchi orthogonal array to identify the optimal experimental conditions. ► Controlling the size and shape of particles via applied voltage and oxalate concentration. ► Characterization of zinc oxalate nanoparticles by SEM, UV–vis, FT-IR and TG–DTA. - Abstract: A rapid, clean and simple electrodeposition method was designed for the synthesis of zinc oxalate nanoparticles. Zinc oxalate nanoparticles in different size and shapes were electrodeposited by electrolysis of a zinc plate anode in sodium oxalate aqueous solutions. It was found that the size and shape of the product could be tuned by electrolysis voltage, oxalate ion concentration, and stirring rate of electrolyte solution. A Taguchi orthogonal array design was designed to identify the optimal experimental conditions. The morphological characterization of the product was carried out by scanning electron microscopy. UV–vis and FT-IR spectroscopies were also used to characterize the electrodeposited nanoparticles. The TG–DTA studies of the nanoparticles indicated that the main thermal degradation occurs in two steps over a temperature range of 350–430 °C. In contrast to the existing methods, the present study describes a process which can be easily scaled up for the production of nano-sized zinc oxalate powder.

  10. Hydrogen Generation Via Sodium Borohydride

    NASA Astrophysics Data System (ADS)

    Mohring, Richard M.; Wu, Ying

    2003-07-01

    Along with the technological challenges associated with developing fuel cells and hydrogen burning engines, a major issue that must be addressed to ensure the ultimate success of a hydrogen economy is the ability to store and transport hydrogen effectively. Millennium Cell has developed and patented a proprietary system for storing and generating hydrogen gas called Hydrogen on Demand™. The system releases the hydrogen stored in fuel solutions of sodium borohydride as needed through an easily controllable catalytic process. The fuel itself is water-based, rich in hydrogen content, and non-flammable. It can be stored in plastic containers under no pressure. After the hydrogen from the fuel is consumed, the remaining product, sodium metaborate (chemically similar to borax), can be recycled back into fresh fuel. In this paper, an overview of the Hydrogen on Demand™ technology is presented along with data showing the performance characteristics of practical hydrogen generation systems. A brief discussion of sodium borohydride regeneration chemistry is also provided.

  11. The sodium-sulphur battery

    NASA Astrophysics Data System (ADS)

    Jones, I. W.

    1981-09-01

    The sodium-sulphur battery is considered as a candidate for electric vehicle and bulk storage applications markets estimated to exceed one billion pounds sterling globally by the turn of the century. The sodium-sulphur device offers five times the energy density of conventional batteries, potential cost reductions due to the use of cheap and readily available construction materials, and operates at the relatively low temperatures of 300-400 C. The cells have a solid electrolyte, made by sintering alumina containing 10% sodium oxide, while the electrodes are liquid at operating temperatures. Ceramic element lives in excess of 1000 cycles have been achieved. Attention is given such design details as the thermal and physical properties of glass/ceramic seals and current collector materials and structure.

  12. Galactic Sodium from AGB Stars

    NASA Astrophysics Data System (ADS)

    Izzard, R. G.; Gibson, B. K.; Stancliffe, R. J.

    2007-11-01

    Galactic chemical evolution (GCE) models which include sodium from type II supernovae (SNe) alone underestimate the abundance of sodium in the interstellar medium by a factor of 2 to 3 over about 3 ridex in metallicity and predict a flat behavior in the evolution of riNafe at super-solar metallicities. Conversely, recent observations of stars with rifeh ˜ +0.4 suggest that riNafe increases at high metallicity. We have combined stellar evolution models of asymptotic giant branch (AGB) and Wolf-Rayet (WR) stars with the latest SN yields in an attempt to resolve these problems dots and have created many more.

  13. Tremor due to sodium valproate.

    PubMed

    Hyman, N M; Dennis, P D; Sinclair, K G

    1979-08-01

    Four patients developed postural tremor after ingestion of sodium valproate. The tremor was recorded by a variable-capacitance transducer and was of the "benign essential" type. The dosages of sodium valproate varied between 1000 mg and 2000 mg daily and serum levels were between 34.9 microgram per milliliter and 154.3 microgram per milliliter. Tremor was ameliorated in two cases when the dosage was reduced. In only one case was the serum level in the toxic range for our laboratory. The pharmacology of essential tremor is unknown; production of a similar tremor by a drug could serve as a biochemical model. PMID:379690

  14. Nanoparticles with entrapped α-tocopherol: synthesis, characterization, and controlled release

    NASA Astrophysics Data System (ADS)

    Zigoneanu, Imola Gabriela; Astete, Carlos Ernesto; Mirela Sabliov, Cristina

    2008-03-01

    An emulsion evaporation method was used to synthesize spherical poly(DL-lactide-co-glycolide) (PLGA) nanoparticles with entrapped α-tocopherol. Two different surfactants were used: sodium dodecyl sulfate (SDS) and poly(vinyl alcohol) (PVA). For SDS nanoparticles, the size of the nanoparticles decreased significantly with the entrapment of α-tocopherol in the PLGA matrix, while the size of PVA nanoparticles remained unchanged. The polydispersity index after synthesis was under 0.100 for PVA nanoparticles and around 0.150 for SDS nanoparticles. The zeta potential was negative for all PVA nanoparticles. The entrapment efficiency of α-tocopherol in the polymeric matrix was approximately 89% and 95% for nanoparticles with 8% and 16% α-tocopherol theoretical loading, respectively. The residual PVA associated with the nanoparticles after purification was approximately 6% ( w/w relative to the nanoparticles). The release profile showed an initial burst followed by a slower release of the α-tocopherol entrapped inside the PLGA matrix. The release for nanoparticles with 8% α-tocopherol theoretical loading (86% released in the first hour) was faster than the release for the nanoparticles with 16% α-tocopherol theoretical loading (34% released in the first hour).

  15. Development and characterization of metal oxide nanoparticles for the delivery of anticancer drug.

    PubMed

    Sharma, Harshita; Kumar, Krishan; Choudhary, Chetan; Mishra, Pawan K; Vaidya, Bhuvaneshwar

    2016-01-01

    The aim of the study was to prepare chemotherapeutic agent-loaded zinc oxide nanoparticles for the intracellular delivery of drug, for better therapeutic activity. Zinc oxide nanoparticles have inherent anticancer properties, hence it was envisaged that by loading the anticancer drug into zinc oxide nanoparticles, enhanced anticancer activity might be observed. Zinc oxide nanoparticles were prepared using zinc nitrate and sodium hydroxide. Starch was used as the stabilizing agent. The nanoparticles prepared were characterized for size, shape, entrapment efficiency, and drug release. Further, cell line studies were performed to evaluate cellular uptake and cytotoxicity profile using MCF-7 cells. A hemolysis study was performed to check the acute toxicity of the nanoparticles. The nanoparticles were found to be 476.4 ± 2.51 nm in size, with low PDI (0.312 ± 0.02) and high entrapment efficiency (> 85%). The nanoparticles were stable, and did not form aggregates on storage in the dispersed form. A cytotoxicity study demonstrated that drug-loaded zinc oxide nanoparticles exhibited higher anticancer activity as compared to either blank zinc oxide nanoparticles and doxorubicin (DOX) alone, or their mixture. A hemolytic test revealed that the prepared zinc oxide nanoparticles caused negligible hemolysis. Thus, it can be concluded that zinc oxide nanoparticles loaded with DOX resulted in better uptake of the chemotherapeutic agent, and at the same time, showed low toxicity towards normal cells. PMID:25406734

  16. In situ Microscopic Observation of Sodium Deposition/Dissolution on Sodium Electrode

    NASA Astrophysics Data System (ADS)

    Yui, Yuhki; Hayashi, Masahiko; Nakamura, Jiro

    2016-03-01

    Electrochemical sodium deposition/dissolution behaviors in propylene carbonate-based electrolyte solution were observed by means of in situ light microscopy. First, granular sodium was deposited at pits in a sodium electrode in the cathodic process. Then, the sodium particles grew linearly from the electrode surface, becoming needle-like in shape. In the subsequent anodic process, the sodium dissolved near the base of the needles on the sodium electrode and the so-called “dead sodium” broke away from the electrode. The mechanisms of electrochemical sodium deposition and dissolution on a copper electrode were similar to those on the sodium electrode.

  17. In situ Microscopic Observation of Sodium Deposition/Dissolution on Sodium Electrode

    PubMed Central

    Yui, Yuhki; Hayashi, Masahiko; Nakamura, Jiro

    2016-01-01

    Electrochemical sodium deposition/dissolution behaviors in propylene carbonate-based electrolyte solution were observed by means of in situ light microscopy. First, granular sodium was deposited at pits in a sodium electrode in the cathodic process. Then, the sodium particles grew linearly from the electrode surface, becoming needle-like in shape. In the subsequent anodic process, the sodium dissolved near the base of the needles on the sodium electrode and the so-called “dead sodium” broke away from the electrode. The mechanisms of electrochemical sodium deposition and dissolution on a copper electrode were similar to those on the sodium electrode. PMID:26925554

  18. Effects of culture conditions of Pseudomonas aeruginosa strain RB on the synthesis of CdSe nanoparticles.

    PubMed

    Ayano, Hiroyuki; Kuroda, Masashi; Soda, Satoshi; Ike, Michihiko

    2015-04-01

    Cadmium selenide (CdSe) was synthesized by Pseudomonas aeruginosa strain RB in a culture containing lactic acid as a carbon source, 1 mM selenite, and 1 mM cadmium under various conditions. High purity (1.02-1.16 of the atomic ratio of Se to Cd) and efficient synthesis of biogenic CdSe nanoparticles were observed at 25-30°C, 0.05-10 g L(-1) NaCl, and neutral pH conditions compared with other tested conditions. However, the size and shape of synthesized CdSe nanoparticles were not changed by changing culture conditions. The contents of S and Se in the particles respectively increased under alkaline and weak acidic conditions. Furthermore, high temperature (>37°C), high salinity (>10 g L(-1) NaCl), and alkaline pH affected the CdSe-synthesizing rate by strain RB. This report is the first optimizing the culture conditions for synthesizing biogenic CdSe nanoparticles in a batch processing. PMID:25454693

  19. Preparation of Chitosan Nanoparticles: A Study of Influencing Factors

    NASA Astrophysics Data System (ADS)

    Thakur, Anupama; Taranjit

    2011-12-01

    Chitosan (CS), a cationic polysaccharide, offers great advantages for ionic interactions with negatively charged species such as sodium tripolyphosphate (STPP) leading to the formation of biocompatible crosslinked chitosan nanoparticles In the present work, an attempt has been made to systematically study the following factors influencing the ionotropic gelation of chitosan with STPP to produce CS nanoparticles: effect of pH of solution, CS concentration, STPP concentration and CS/STPP ratio. The results show that with the increase in CS concentration, the yield of the nanoparticle decreases whereas size increases. The mean size of the prepared nanoparticles varied between 120 to 720 nm and zeta potential between +14 mV to +53 mV . Nanoparticle size and yield was found to be strongly dependent on solution pH. Nanoparticle size decreased with increase in solution pH from 4 to 5 and yield was found to be maximum at pH = 5. With increase in STPP concentration, the size and yield of the nanoparticle increased. The potential of CS nanoparticles to trap amoxicillin trihydrate, taken as the model drug, was also studied. The maximum drug loading capacity was found to be 35% at a solution pH = 5 for 0.2% CS and 0.086% STPP.

  20. Photoelectron emission from island metallic sodium films during the excitation of localized plasmon resonances

    SciTech Connect

    Vartanyan, T. A.; Vashchenko, E. V. Leonov, N. B.; Przhibel'skii, S. G.; Khromov, V. V.

    2009-07-15

    The photoelectron emission from island sodium films is studied under the action of radiation that is resonant to the collective electron excitations in the nanoparticles forming a film. Noticeable deviations from the Fowler law and an increase in the photoelectron yield are detected. The dependences of the photoeffect efficiency from these films on their structural parameters, the polarization vector, and the angle of radiation incidence are obtained.