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Sample records for epitafial oxides progress

  1. Nitric Oxide in Mammary Tumor Progression

    DTIC Science & Technology

    1998-07-01

    smaller level TIMP-3. This indicated that invasion stimulating effects of endogenous NO are, at least in part , mediated by downregulation TIMP-2 and...vasculature: Inhibition retards tumor growth in vivo. In: Moncada S, Feelisch M, Busse R, Higgs EA (eds) Biology of Nitric Oxide. Part 4: Enzymology...useful in treating certain human cancers either as single agents or as a part of combination therapies. I. Introduction duction of proliferation

  2. [Research progress on methane oxidation in landfill cover soil].

    PubMed

    Wang, Yun-long; Hao, Yong-jun; Wu, Wei-xiang; Chen, Ying-xu

    2007-01-01

    Methane is the second largest contributor after carbon dioxide to global warming, while landfill is considered as one of the major sources of methane emission, accounting for 1.5%-15% of the global methane sources. Methanotrophic microorganisms play an important role in regulating global methane content, and landfill cover soil is proved to have high capacity of methane oxidation. The study of methanotrophic microorganisms in landfill cover soil and their mechanisms in methane oxidation becomes one of the hot research fields in environmental science and applied microbiology. This review summarized the recent progress on the research of methanotrophic microorganisms, mechanisms and dynamics of microbial methane oxidation, co-metabolism of methane and trace landfill gases, and environmental factors affecting methane oxidation in landfill cover soil. Some perspectives for further research on methanotrophic microorganisms in landfill cover soil were discussed.

  3. Recent progress in hydrothermal synthesis of zinc oxide nanomaterials.

    PubMed

    Djurisic, A B; Chen, X Y; Leung, Y H

    2012-06-01

    Hydrothermal synthesis is of considerable interest due to its low cost, simplicity and relatively low growth temperature (typically below 200 °C). Since the synthesis is performed in aqueous solutions (no organic solvents), it can also be safe and environmentally friendly (depending on precursor chemicals). Consequently, it has been a subject of intense research in recent years. In this article, we review recent progress in hydrothermal synthesis of zinc oxide nanomaterials, with focus on practical relevance for a variety of applications.

  4. Physical mechanism of progressive breakdown in gate oxides

    NASA Astrophysics Data System (ADS)

    Palumbo, Felix; Lombardo, Salvatore; Eizenberg, Moshe

    2014-06-01

    The definition of the basic physical mechanisms of the dielectric breakdown (BD) phenomenon is still an open area of research. In particular, in advanced complementary metal-oxide-semiconductor (CMOS) circuits, the BD of gate dielectrics occurs in the regime of relatively low voltage and very high electric field; this is of enormous technological importance, and thus widely investigated but still not well understood. Such BD is characterized by a gradual, progressive growth of the gate leakage through a localized BD spot. In this paper, we report for the first time experimental data and a model which provide understanding of the main physical mechanism responsible for the progressive BD growth. We demonstrate the ability to control the breakdown growth rate of a number of gate dielectrics and provide a physical model of the observed behavior, allowing to considerably improve the reliability margins of CMOS circuits by choosing a correct combination of voltage, thickness, and thermal conductivity of the gate dielectric.

  5. Selenium isotope evidence for progressive oxidation of the Neoproterozoic biosphere

    PubMed Central

    Pogge von Strandmann, Philip A. E.; Stüeken, Eva E.; Elliott, Tim; Poulton, Simon W.; Dehler, Carol M.; Canfield, Don E.; Catling, David C.

    2015-01-01

    Neoproterozoic (1,000–542 Myr ago) Earth experienced profound environmental change, including ‘snowball' glaciations, oxygenation and the appearance of animals. However, an integrated understanding of these events remains elusive, partly because proxies that track subtle oceanic or atmospheric redox trends are lacking. Here we utilize selenium (Se) isotopes as a tracer of Earth redox conditions. We find temporal trends towards lower δ82/76Se values in shales before and after all Neoproterozoic glaciations, which we interpret as incomplete reduction of Se oxyanions. Trends suggest that deep-ocean Se oxyanion concentrations increased because of progressive atmospheric and deep-ocean oxidation. Immediately after the Marinoan glaciation, higher δ82/76Se values superpose the general decline. This may indicate less oxic conditions with lower availability of oxyanions or increased bioproductivity along continental margins that captured heavy seawater δ82/76Se into buried organics. Overall, increased ocean oxidation and atmospheric O2 extended over at least 100 million years, setting the stage for early animal evolution. PMID:26679529

  6. Selenium isotope evidence for progressive oxidation of the Neoproterozoic biosphere.

    PubMed

    Pogge von Strandmann, Philip A E; Stüeken, Eva E; Elliott, Tim; Poulton, Simon W; Dehler, Carol M; Canfield, Don E; Catling, David C

    2015-12-18

    Neoproterozoic (1,000-542 Myr ago) Earth experienced profound environmental change, including 'snowball' glaciations, oxygenation and the appearance of animals. However, an integrated understanding of these events remains elusive, partly because proxies that track subtle oceanic or atmospheric redox trends are lacking. Here we utilize selenium (Se) isotopes as a tracer of Earth redox conditions. We find temporal trends towards lower δ(82/76)Se values in shales before and after all Neoproterozoic glaciations, which we interpret as incomplete reduction of Se oxyanions. Trends suggest that deep-ocean Se oxyanion concentrations increased because of progressive atmospheric and deep-ocean oxidation. Immediately after the Marinoan glaciation, higher δ(82/76)Se values superpose the general decline. This may indicate less oxic conditions with lower availability of oxyanions or increased bioproductivity along continental margins that captured heavy seawater δ(82/76)Se into buried organics. Overall, increased ocean oxidation and atmospheric O2 extended over at least 100 million years, setting the stage for early animal evolution.

  7. Selenium isotope evidence for progressive oxidation of the Neoproterozoic biosphere

    NASA Astrophysics Data System (ADS)

    Pogge von Strandmann, Philip A. E.; Stüeken, Eva E.; Elliott, Tim; Poulton, Simon W.; Dehler, Carol M.; Canfield, Don E.; Catling, David C.

    2015-12-01

    Neoproterozoic (1,000-542 Myr ago) Earth experienced profound environmental change, including `snowball' glaciations, oxygenation and the appearance of animals. However, an integrated understanding of these events remains elusive, partly because proxies that track subtle oceanic or atmospheric redox trends are lacking. Here we utilize selenium (Se) isotopes as a tracer of Earth redox conditions. We find temporal trends towards lower δ82/76Se values in shales before and after all Neoproterozoic glaciations, which we interpret as incomplete reduction of Se oxyanions. Trends suggest that deep-ocean Se oxyanion concentrations increased because of progressive atmospheric and deep-ocean oxidation. Immediately after the Marinoan glaciation, higher δ82/76Se values superpose the general decline. This may indicate less oxic conditions with lower availability of oxyanions or increased bioproductivity along continental margins that captured heavy seawater δ82/76Se into buried organics. Overall, increased ocean oxidation and atmospheric O2 extended over at least 100 million years, setting the stage for early animal evolution.

  8. Progress towards producing and trapping cold nitric oxide

    NASA Astrophysics Data System (ADS)

    Dahal, Parshuram

    I present the experimental results of a new source of cold molecular production using activated carbon and the design of the necessary apparatus. This new source may eliminate the need for laser ablation loading in buffer gas cooling experiments. I also analyze the relative signal amplitude of rotational lines of cold Nitric Oxide (NO) molecules in its lower fine structure state. Experimental results showing the effects of the hexapole velocity filter on the production of lowest ro-vibrational low field seeking states of a cold molecular sample of NO is also discussed. The sample is produced by the extraction of the cold fraction of the Maxwell-Boltzman distribution of a thermal source. I also present a computer simulation method for filtering, guiding and magnetic trapping of cold molecular NO. In the filtering process, the low field electric seeking molecules interact with an inhomogeneous electrostatic field of a hexapole guide which is exploited to select the slow molecules from a cold molecular source. Given my computer simulation work, I assert that the resulting cold fraction in the non-magnetic 2pi 1/2 ground state can be directed into a permanent magnetic trap where it could be optically pumped into the 2pi3/2 fine structure state which can be magnetically trapped. I present the full simulation of the procedure and progress toward getting experimental results regarding the magnetic trapping of NO.

  9. Progress Report: Oxidation Stability Studies of Deuterated Esters.

    DTIC Science & Technology

    1983-04-26

    esterification goes to completion and hydrolysis does not occur. *i (ii) In the presence of a catalyst (p-toluene sulphonic -" acid ), a fairly low...compounds with the antioxidant. The enhancement in oxidation stability attributable to deuteration (97%) of the acid moiety of the ester appears to be 3...meet these requirements. These esters exhibit very good thermal and oxidative stability at high temperatures (>2000C), excellent viscosity

  10. Enzymes of respiratory iron oxidation. Progress report, March 1990--November 1991

    SciTech Connect

    Blake, R. II

    1991-12-31

    This report focuses on the progress made in three areas of research concerned with enzymes involved in respiratory iron oxidation. The three areas are as follows: development of an improved procedure for the routine large scale culture of iron oxidizing chemolithotrophs based on the in-situ electrolysis of the soluble iron in the growth medium; to perform iron oxidation kinetic studies on whole cells using the oxygen electrode; and to identify, separate, purify, and characterize the individual cellular components.

  11. Progress in Nano-Engineered Anodic Aluminum Oxide Membrane Development

    PubMed Central

    Poinern, Gerrard Eddy Jai; Ali, Nurshahidah; Fawcett, Derek

    2011-01-01

    The anodization of aluminum is an electro-chemical process that changes the surface chemistry of the metal, via oxidation, to produce an anodic oxide layer. During this process a self organized, highly ordered array of cylindrical shaped pores can be produced with controllable pore diameters, periodicity and density distribution. This enables anodic aluminum oxide (AAO) membranes to be used as templates in a variety of nanotechnology applications without the need for expensive lithographical techniques. This review article is an overview of the current state of research on AAO membranes and the various applications of nanotechnology that use them in the manufacture of nano-materials and devices or incorporate them into specific applications such as biological/chemical sensors, nano-electronic devices, filter membranes and medical scaffolds for tissue engineering. PMID:28880002

  12. Genes Involved in Oxidation and Prostate Cancer Progression

    DTIC Science & Technology

    2007-01-01

    Kimmel Comprehensive Cancer Center at Johns Hopkins , Baltimore, Maryland3 Corresponding author: Elizabeth A. Platz...Prostate Cancer Progression PRINCIPAL INVESTIGATOR: Elizabeth A. Platz, ScD, MPH CONTRACTING ORGANIZATION: Johns Hopkins University... Cancer Prevention and Control Program at the Sidney Kimmel Comprehensive Cancer Center . o With Dr. James Herman and other Sidney Kimmel

  13. Research Progress on Signaling Pathway-Associated Oxidative Stress in Endothelial Cells

    PubMed Central

    Li, Jiajia; Huang, Ping; Zhang, Lin; Wu, Wei; Ma, Youchu

    2017-01-01

    Studying the mechanisms of oxidative stress in endothelial cells is vital to the discovery of novel drugs for the treatment of cardiovascular disease. This article reviews the progress within the field of the role of oxidative responses in the physiology and growth of endothelial cells and emphasizes the effects of several main signal pathways involved in the oxidative stress of endothelial cells. Herein, we aim to provide scientific direction that can serve as a basis for researchers specializing in the signaling pathway of oxidative stress. PMID:28503253

  14. Genes Involved in Oxidation and Prostate Cancer Progression

    DTIC Science & Technology

    2008-01-01

    association of genes and prostate cancer progression from these simulated nested case - control studies to what would be observed if the entire...Control Sampling: Methods for Nested Case - Control Studies of Candidate Genes and Prostate Cancer Progression”. This work forms one aim of MS Wang’s...prostate cancer risk: results from two large nested case - control studies . Carcinogenesis. 2007 Nov 13; [Epub ahead of print] PMID: 17999989 Dr

  15. The Role of Nitric Oxide Synthase Uncoupling in Tumor Progression

    PubMed Central

    Rabender, Christopher S.; Alam, Asim; Sundaresan, Gobalakrishnan; Cardnell, Robert J.; Yakovlev, Vasily A.; Mukhopadhyay, Nitai D.; Graves, Paul; Zweit, Jamal; Mikkelsen, Ross B.

    2015-01-01

    Here evidence suggests that nitric oxide synthases (NOS) of tumor cells, in contrast to normal tissues, synthesize predominantly superoxide and peroxynitrite. Based on HPLC analysis, the underlying mechanism for this uncoupling is a reduced tetrahydrobiopterin: dihydrobiopterin ratio (BH4:BH2) found in breast, colorectal, epidermoid and head and neck tumors compared to normal tissues. Increasing BH4:BH2 and reconstitution of coupled NOS activity in breast cancer cells with the BH4 salvage pathway precursor, sepiapterin, causes significant shifts in downstream signaling including increased cGMP-dependent protein kinase (PKG) activity, decreased β-catenin expression and TCF4 promoter activity, and reduced NF-κB promoter activity. Sepiapterin inhibited breast tumor cell growth in vitro and in vivo as measured by clonogenic assay, Ki67 staining and 18F-deoxyglucose positron emission tomography (FDG-PET). In summary, using diverse tumor types, it is demonstrated that the BH4:BH2 ratio is lower in tumor tissues and as a consequence nitric oxide synthase activity generates more peroxynitrite and superoxide anion than nitric oxide resulting in important tumor growth promoting and anti-apoptotic signaling properties. Implications The synthetic BH4, Kuvan®, is used to elevate BH4:BH2 in some phenylketonuria patients and to treat diseases associated with endothelial dysfunction suggesting a novel, testable approach for correcting an abnormality of tumor metabolism to control tumor growth. PMID:25724429

  16. Astaxanthin blocks preeclampsia progression by suppressing oxidative stress and inflammation.

    PubMed

    Xuan, Rong-Rong; Niu, Ting-Ting; Chen, Hai-Min

    2016-09-01

    To investigate the antioxidative effect of astaxanthin on Nω-nitro-L-arginine methyl ester (L-NAME)-induced preeclamptic rats. Cell survival, the level of reactive oxygen species (ROS) and the changes in mitochondrial membrane potential (MMP) were examined in astaxanthin and H2O2-treated human umbilical vein endothelial cells (HUVECs). The preeclamptic Sprague-Dawley (SD) rat model was established by injection of L‑NAME and treatment with astaxanthin. The activities of malondialdehyde (MDA), superoxide dismutase (SOD) and nitric oxide synthase (NOS) in serum were analyzed. Pathological changes were examined by hematoxylin and eosin (H&E) staining. The expression of nuclear factor (NF)‑κB, Rho‑associated protein kinase II (ROCK II), heme oxygenase‑1 (HO‑1) and caspase 3 in preeclamptic placentas were examined by immunohistochemistry. Astaxanthin significantly reduced H2O2‑induced HUVEC cell death, decreased ROS and increased MMP. Astaxanthin significantly reduced blood pressure and the content of MDA, but significantly increased the activity of SOD in preeclamptic rats. The urinary protein and the level of NO and NOS were also decreased. H&E staining revealed that the thickness of the basilar membrane was increased, while the content of trophoblast cells and spiral arteries were reduced following astaxanthin treatment. Immunohistochemistry results showed that the expression of NF‑κB, ROCK II and caspase 3 in preeclamptic placentas was significantly decreased after astaxanthin treatment, while HO‑1 expression was increased. In conclusion, astaxanthin inhibited H2O2‑induced oxidative stress in HUVECs. Astaxanthin treatment significantly improved L‑NAME‑induced preeclamptic symptoms and reduced the oxidative stress and inflammatory damages in preeclamptic placentas. Astaxanthin treatment may effectively prevent and treat preeclampsia.

  17. Enzymes of respiratory iron oxidation. Progress report, March 1990--June 1992

    SciTech Connect

    Blake, R. II

    1992-12-31

    This report describes experimental progress in characterizing and identifying redox proteins in a number of iron-oxidizing bacteria. Sections of the paper are entitled (1) In Situ electrolysis was explored to achieve enhanced yields of iron-oxidizing bacteria, (2)Structure/function studies were performed on redox-active biomolecules from Thiobacillus ferrooxidans, (3) Novel redox-active biomolecules were demonstrated in other iron autotrophs, and (4) New probes of metalloprotein electron-transfer reactions were synthesized and characterized.

  18. Superior catalysts for selective catalytic reduction of nitric oxide. Quarterly technical progress report, January 1, 1995--March 31, 1995

    SciTech Connect

    Li, W.B.; Yang, R.T.

    1995-12-01

    During this quarter, progress was made on the following tasks: TPD techniques were employed to study the reaction mechanism of the selective catalytic reduction of nitrogen oxide with ammonia over iron oxide pillared clay catalyst; and a sulfur dioxide resistant iron oxide/titanium oxide catalyst was developed.

  19. Recent progress in magnetic iron oxide-semiconductor composite nanomaterials as promising photocatalysts

    NASA Astrophysics Data System (ADS)

    Wu, Wei; Changzhong Jiang, Affc; Roy, Vellaisamy A. L.

    2014-11-01

    Photocatalytic degradation of toxic organic pollutants is a challenging tasks in ecological and environmental protection. Recent research shows that the magnetic iron oxide-semiconductor composite photocatalytic system can effectively break through the bottleneck of single-component semiconductor oxides with low activity under visible light and the challenging recycling of the photocatalyst from the final products. With high reactivity in visible light, magnetic iron oxide-semiconductors can be exploited as an important magnetic recovery photocatalyst (MRP) with a bright future. On this regard, various composite structures, the charge-transfer mechanism and outstanding properties of magnetic iron oxide-semiconductor composite nanomaterials are sketched. The latest synthesis methods and recent progress in the photocatalytic applications of magnetic iron oxide-semiconductor composite nanomaterials are reviewed. The problems and challenges still need to be resolved and development strategies are discussed.

  20. Recent progress in magnetic iron oxide-semiconductor composite nanomaterials as promising photocatalysts.

    PubMed

    Wu, Wei; Changzhong Jiang; Roy, Vellaisamy A L

    2015-01-07

    Photocatalytic degradation of toxic organic pollutants is a challenging tasks in ecological and environmental protection. Recent research shows that the magnetic iron oxide-semiconductor composite photocatalytic system can effectively break through the bottleneck of single-component semiconductor oxides with low activity under visible light and the challenging recycling of the photocatalyst from the final products. With high reactivity in visible light, magnetic iron oxide-semiconductors can be exploited as an important magnetic recovery photocatalyst (MRP) with a bright future. On this regard, various composite structures, the charge-transfer mechanism and outstanding properties of magnetic iron oxide-semiconductor composite nanomaterials are sketched. The latest synthesis methods and recent progress in the photocatalytic applications of magnetic iron oxide-semiconductor composite nanomaterials are reviewed. The problems and challenges still need to be resolved and development strategies are discussed.

  1. Protein Oxidation in Aging: Does It Play a Role in Aging Progression?

    PubMed Central

    Reeg, Sandra

    2015-01-01

    Abstract Significance: A constant accumulation of oxidized proteins takes place during aging. Oxidation of proteins leads to a partial unfolding and, therefore, to aggregation. Protein aggregates impair the activity of cellular proteolytic systems (proteasomes, lysosomes), resulting in further accumulation of oxidized proteins. In addition, the accumulation of highly crosslinked protein aggregates leads to further oxidant formation, damage to macromolecules, and, finally, to apoptotic cell death. Furthermore, protein oxidation seems to play a role in the development of various age-related diseases, for example, neurodegenerative diseases. Recent Advances: The highly oxidized lipofuscin accumulates during aging. Lipofuscin formation might cause impaired lysosomal and proteasomal degradation, metal ion accumulation, increased reactive oxygen species formation, and apoptosis. Critical Issues: It is still unclear to which extent protein oxidation is involved in the progression of aging and in the development of some age-related diseases. Future Directions: An extensive knowledge of the effects of protein oxidation on the aging process and its contribution to the development of age-related diseases could enable further strategies to reduce age-related impairments. Strategies aimed at lowering aggregate formation might be a straightforward intervention to reduce age-related malfunctions of organs. Antioxid. Redox Signal. 23, 239–255. PMID:25178482

  2. Conditional Induction of Oxidative Stress in RPE: A Mouse Model of Progressive Retinal Degeneration.

    PubMed

    Biswal, Manas R; Ildefonso, Cristhian J; Mao, Haoyu; Seo, Soo Jung; Wang, Zhaoyang; Li, Hong; Le, Yun Z; Lewin, Alfred S

    2016-01-01

    An appropriate animal model is essential to screening drugs or designing a treatment strategy for geographic atrophy. Since oxidative stress contributes to the pathological changes of the retinal pigment epithelium (RPE), we are reporting a new mouse AMD model of retinal degeneration by inducing mitochondrial oxidative stress in RPE. Sod2 the gene for manganese superoxide dismutase (MnSOD) was deleted in RPE layer using conditional knockout strategy. Fundus microscopy, SD-OCT and electroretinography were used to monitor retinal structure and function in living animals and microscopy was used to assess pathology post mortem. Tissue specific deletion of Sod2 caused elevated signs of oxidative stress, RPE dysfunction and showed some key features of AMD. Due to induction of oxidative stress, the conditional knockout mice show progressive reduction in ERG responses and thinning of outer nuclear layer (ONL) compared to non-induced littermates.

  3. The Warburg effect in tumor progression: Mitochondrial oxidative metabolism as an anti-metastasis mechanism

    PubMed Central

    Lu, Jianrong; Tan, Ming; Cai, Qingsong

    2014-01-01

    Compared to normal cells, cancer cells strongly upregulate glucose uptake and glycolysis to give rise to increased yield of intermediate glycolytic metabolites and the end product pyruvate. Moreover, glycolysis is uncoupled from the mitochondrial tricarboxylic acid (TCA) cycle and oxidative phosphorylation (OXPHOS) in cancer cells. Consequently, the majority of glycolysis-derived pyruvate is diverted to lactate fermentation and kept away from mitochondrial oxidative metabolism. This metabolic phenotype is known as the Warburg effect. While it has become widely accepted that the glycolytic intermediates provide essential anabolic support for cell proliferation and tumor growth, it remains largely elusive whether and how the Warburg metabolic phenotype may play a role in tumor progression. We hereby review the cause and consequence of the restrained oxidative metabolism, in particular in tumor metastasis. Cells change or lose their extracellular matrix during the metastatic process. Inadequate/inappropriate matrix attachment generates reactive oxygen species (ROS) and causes a specific type of cell death, termed anoikis, in normal cells. Although anoikis is a barrier to metastasis, cancer cells have often acquired elevated threshold for anoikis and hence heightened metastatic potential. As ROS are inherent byproducts of oxidative metabolism, forced stimulation of glucose oxidation in cancer cells raises oxidative stress and restores cells’ sensitivity to anoikis. Therefore, by limiting the pyruvate flux into mitochondrial oxidative metabolism, the Warburg effect enables cancer cells to avoid excess ROS generation from mitochondrial respiration and thus gain increased anoikis resistance and survival advantage for metastasis. Consistent with this notion, pro-metastatic transcription factors HIF and Snail attenuate oxidative metabolism, whereas tumor suppressor p53 and metastasis suppressor KISS1 promote mitochondrial oxidation. Collectively, these findings reveal

  4. The Warburg effect in tumor progression: mitochondrial oxidative metabolism as an anti-metastasis mechanism.

    PubMed

    Lu, Jianrong; Tan, Ming; Cai, Qingsong

    2015-01-28

    Compared to normal cells, cancer cells strongly upregulate glucose uptake and glycolysis to give rise to increased yield of intermediate glycolytic metabolites and the end product pyruvate. Moreover, glycolysis is uncoupled from the mitochondrial tricarboxylic acid (TCA) cycle and oxidative phosphorylation (OXPHOS) in cancer cells. Consequently, the majority of glycolysis-derived pyruvate is diverted to lactate fermentation and kept away from mitochondrial oxidative metabolism. This metabolic phenotype is known as the Warburg effect. While it has become widely accepted that the glycolytic intermediates provide essential anabolic support for cell proliferation and tumor growth, it remains largely elusive whether and how the Warburg metabolic phenotype may play a role in tumor progression. We hereby review the cause and consequence of the restrained oxidative metabolism, in particular in the context of tumor metastasis. Cells change or lose their extracellular matrix during the metastatic process. Inadequate/inappropriate matrix attachment generates reactive oxygen species (ROS) and causes a specific type of cell death, termed anoikis, in normal cells. Although anoikis is a barrier to metastasis, cancer cells have often acquired elevated threshold for anoikis and hence heightened metastatic potential. As ROS are inherent byproducts of oxidative metabolism, forced stimulation of glucose oxidation in cancer cells raises oxidative stress and restores cells' sensitivity to anoikis. Therefore, by limiting the pyruvate flux into mitochondrial oxidative metabolism, the Warburg effect enables cancer cells to avoid excess ROS generation from mitochondrial respiration and thus gain increased anoikis resistance and survival advantage for metastasis. Consistent with this notion, pro-metastatic transcription factors HIF and Snail attenuate oxidative metabolism, whereas tumor suppressor p53 and metastasis suppressor KISS1 promote mitochondrial oxidation. Collectively, these

  5. Recent Progress in Using Advanced Characterization and Modeling Approaches to Study Radiation Effects in Oxide Ceramics

    DOE PAGES

    Bai, Xian-Ming

    2014-10-23

    I serve as a Guest Editor for the Nuclear Materials Committee of the TMS Structural Materials Division, and coordinated the topic ‘‘Radiation Effects in Oxide Ceramics and Novel LWR Fuels" for JOM in the December 2014 issue. I selected five articles related this topic. These articles talk about some recent progress of using advanced experimental and modeling tools to study radiation effects in oxide ceramics at atomistic scale and mesoscale. In this guest editor commentary article, I summarize the novel aspects of these papers and also provide some suggestions for future research directions.

  6. Defects and transport in mixed oxides. Progress report, October 1, 1993--December 20, 1994

    SciTech Connect

    Dieckmann, R.

    1994-12-20

    The PI of this research program came to Cornell University from Hannover (Germany) in July 1987. Beginning in Fall 1987 a new research group and a new research facilities were built up at Cornell. The program {open_quotes}Defects and Transport in Mixed Oxides{close_quotes} was started in July 1988. The last progress report for this program was written on September 30, 1993 and submitted to DOE with the last renewal proposal. Significant progress has been made in the areas of: (i) the nonstoichiometry of quasi-binary spinels, (ii) the cation tracer diffusion in oxide solid solutions of the type (Fe,Me){sub 3{minus}{delta}}O{sub 4}, (iii) the Monte-Carlo simulation of the cation diffusion in spinel solid solutions, (iv) interdiffusion measurements in the spinel solution (Fe,Mn){sub 3{minus}{delta}}O{sub 4}, and (v) defect-related properties of Co{sub 1{minus}{delta}}O.

  7. Amyloid β-peptide (1-42)-induced oxidative stress in Alzheimer disease: importance in disease pathogenesis and progression.

    PubMed

    Butterfield, D Allan; Swomley, Aaron M; Sultana, Rukhsana

    2013-09-10

    Alzheimer disease (AD) is an age-related neurodegenerative disease. AD is characterized by progressive cognitive impairment. One of the main histopathological hallmarks of AD brain is the presence of senile plaques (SPs) and another is elevated oxidative stress. The main component of SPs is amyloid beta-peptide (Aβ) that is derived from the proteolytic cleavage of amyloid precursor protein. Recent studies are consistent with the notion that methionine present at 35 position of Aβ is critical to Aβ-induced oxidative stress and neurotoxicity. Further, we also discuss the signatures of oxidatively modified brain proteins, identified using redox proteomics approaches, during the progression of AD. The exact relationships of the specifically oxidatively modified proteins in AD pathogenesis require additional investigation. Further studies are needed to address whether the therapies directed toward brain oxidative stress and oxidatively modified key brain proteins might help delay or prevent the progression of AD.

  8. Oxidative stress and antioxidant responses to progressive resistance exercise intensity in trained and untrained males

    PubMed Central

    Özdemir, F; Çolak, R

    2015-01-01

    The relationship between oxidative stress and some exercise components of resistance exercise (e.g. intensity, exercise volume) has not been clearly defined. Additionally, the oxidative stress markers may respond differently in various conditions. This study aims to determine the effects of progressive intensity of resistance exercise (RE) on oxidative stress and antioxidants in trained and untrained men, and also to investigate the possible threshold intensity required to evoke oxidative stress. RE trained (N=8) and untrained (N=8) men performed the leg extension RE at progressive intensities standardized for total volume: 1x17 reps at 50% of one-repetition maximum (1RM); 1x14 reps at 60% of 1RM; 1x12 reps at 70% of 1RM; 2x5 reps at 80% of 1RM; and 3x3 reps at 90% of 1RM. Blood samples were drawn before (PRE) and immediately after each intensity, and after 30 minutes, 60 minutes and 24 hours following the RE. Lipid-hydroperoxide (LHP) significantly increased during the test and then decreased during the recovery in both groups (p<0.05); the POST-24 h LHP level was lower than PRE-LHP. Protein carbonyl (PCO) and superoxide dismutase (SOD) significantly increased (p<0.05); however, 8-hydroxy-2’-deoxyguanosine (8-OHdG) and glutathione (GSH) were not affected by the RE (p > 0.05). The results indicated that there was no significant training status x intensity interaction for examined variables (p > 0.05). Standardized volume of RE increased oxidative stress responses. Our study suggests that lower intensity (50%) is enough to increase LHP, whereas higher intensity (more than 80%) is required to evoke protein oxidation. PMID:26681835

  9. Salutary effects of a novel oxidative stress modulator on adenine-induced chronic progressive tubulointerstitial nephropathy

    PubMed Central

    Nicholas, Susanne B; Yuan, Jun; Aminzadeh, Amin; Norris, Keith C; Crum, Albert; Vaziri, Nosratola D

    2012-01-01

    Background Oxidative stress and inflammation promote the development and progression of chronic kidney disease. Oxidative stress is associated with depletion of tissue glutathione (GSH), the most abundant endogenous intracellular antioxidant, but degradation of oral GSH by digestive enzymes limits its therapeutic use. We hypothesized that GSH repletion with F1, a novel oral GSH precursor containing cystine as a cysteine carrier, would restore tissue GSH and attenuate oxidative stress and inflammation, and thereby reduce the severity of interstitial nephropathy in chronic renal failure (CRF). Methods Male Sprague-Dawley rats (n=5-8) were assigned to 3 groups: Control (regular rat chow), CRF (rat chow containing 0.7% adenine), and F1-treated CRF (rat chow containing 0.7% adenine and F1, 0.5g/kg/day) for 2-weeks. Animals were switched to regular chow and euthanized after 2 additional weeks. Results Consumption of 0.7% adenine-containing diet caused azotemia; severe kidney swelling; heavy tubular and glomerular damage; massive tubulointerstitial nephropathy; impaired urinary concentrating capacity; severe anemia; increased markers of oxidative stress, plasma oxidized glutathione disulfide (GSSG); reduced GSH/GSSG ratio and manganese superoxide dismutase; increased expression of inflammatory mediators (cyclooxygenase-2, cytoplasmic NF-κB, p-IκBα, nuclear NF-κB p65), and 3-nitrotyrosine, p<0.05. Co-treatment with F1 significantly attenuated tubulointerstitial inflammation and edema, improved urinary concentrating capacity, azotemia and anemia, and normalized markers of tissue oxidative and nitrosative stress, p<0.05. Conclusions The novel oxidative stress modulator, F1, markedly attenuated oxidative stress indicators, inflammation, renal injury and dysfunction in the rat model of CRF. Studies to determine the effects of F1 in other models of acute and CRF are warranted. PMID:22937204

  10. Nocturnal hypoxia-induced oxidative stress promotes progression of pediatric non-alcoholic fatty liver disease.

    PubMed

    Sundaram, Shikha S; Halbower, Ann; Pan, Zhaoxing; Robbins, Kristen; Capocelli, Kelley E; Klawitter, Jelena; Shearn, Colin T; Sokol, Ronald J

    2016-09-01

    Oxidative stress is proposed as a central mediator in NAFLD pathogenesis, but the specific trigger for reactive oxygen species generation has not been clearly delineated. In addition, emerging evidence shows that obesity related obstructive sleep apnea (OSA) and nocturnal hypoxia are associated with NAFLD progression in adults. The aim of this study was to determine if OSA/nocturnal hypoxia-induced oxidative stress promotes the progression of pediatric NAFLD. Subjects with biopsy proven NAFLD and lean controls were studied. Subjects underwent polysomnograms, liver histology scoring, laboratory testing, urine F(2)-isoprostanes (measure of lipid peroxidation) and 4-hydroxynonenal liver immunohistochemistry (in situ hepatic lipid peroxidation). We studied 36 adolescents with NAFLD and 14 lean controls. The OSA/hypoxia group (69% of NAFLD subjects) had more severe fibrosis (64% stage 0-2; 36% stage 3) than those without OSA/hypoxia (100% stage 0-2), p=0.03. Higher F(2)-isoprostanes correlated with apnea/hypoxia index (r=0.39, p=0.03), % time SaO2 <90% (r=0.56, p=0.0008) and inversely with SaO2 nadir (r=-0.46, p=0.008). OSA/hypoxia was most severe in subjects with the greatest 4HNE staining (p=0.03). Increasing F(2)-isoprostanes(r=0.32, p=0.04) and 4HNE hepatic staining (r=0.47, p=0.007) were associated with worsening steatosis. Greater oxidative stress occurred in subjects with definite NASH as measured by F(2)-isoprostanes (p=0.06) and hepatic 4HNE (p=0.03) compared to those with borderline/not NASH. These data support the role of nocturnal hypoxia as a trigger for localized hepatic oxidative stress, an important factor associated with the progression of NASH and hepatic fibrosis in obese pediatric patients. Obstructive sleep apnea and low nighttime oxygen are associated with NAFLD progression in adults. In this study, we show that adolescents with NAFLD who have OSA and low oxygen have significant scar tissue in their livers. NAFLD subjects affected by OSA and low

  11. High amylose resistant starch diet ameliorates oxidative stress, inflammation, and progression of chronic kidney disease.

    PubMed

    Vaziri, Nosratola D; Liu, Shu-Man; Lau, Wei Ling; Khazaeli, Mahyar; Nazertehrani, Sohrab; Farzaneh, Seyed H; Kieffer, Dorothy A; Adams, Sean H; Martin, Roy J

    2014-01-01

    Inflammation is a major mediator of CKD progression and is partly driven by altered gut microbiome and intestinal barrier disruption, events which are caused by: urea influx in the intestine resulting in dominance of urease-possessing bacteria; disruption of epithelial barrier by urea-derived ammonia leading to endotoxemia and bacterial translocation; and restriction of potassium-rich fruits and vegetables which are common sources of fermentable fiber. Restriction of these foods leads to depletion of bacteria that convert indigestible carbohydrates to short chain fatty acids which are important nutrients for colonocytes and regulatory T lymphocytes. We hypothesized that a high resistant starch diet attenuates CKD progression. Male Sprague Dawley rats were fed a chow containing 0.7% adenine for 2 weeks to induce CKD. Rats were then fed diets supplemented with amylopectin (low-fiber control) or high fermentable fiber (amylose maize resistant starch, HAM-RS2) for 3 weeks. CKD rats consuming low fiber diet exhibited reduced creatinine clearance, interstitial fibrosis, inflammation, tubular damage, activation of NFkB, upregulation of pro-inflammatory, pro-oxidant, and pro-fibrotic molecules; impaired Nrf2 activity, down-regulation of antioxidant enzymes, and disruption of colonic epithelial tight junction. The high resistant starch diet significantly attenuated these abnormalities. Thus high resistant starch diet retards CKD progression and attenuates oxidative stress and inflammation in rats. Future studies are needed to explore the impact of HAM-RS2 in CKD patients.

  12. Disease progression and oxidative stress are associated with higher serum ferritin levels in patients with multiple sclerosis.

    PubMed

    Ferreira, Katerine Panichi Zanin; Oliveira, Sayonara R; Kallaur, Ana Paula; Kaimen-Maciel, Damacio R; Lozovoy, Marcell Alysson B; de Almeida, Elaine Regina Delicato; Morimoto, Helena Kaminami; Mezzaroba, Leda; Dichi, Isaias; Reiche, Edna Maria Vissoci; Simão, Andréa Name Colado

    2017-02-15

    Hyperferritinemia and oxidative stress have been implicated in the pathogenesis of multiple sclerosis (MS). The aim of the present study was to evaluate the serum levels of ferritin and to verify their association with oxidative stress markers and MS progression. This study included 164 MS patients, which were divided in two groups according to their levels of ferritin (cut off 125.6μg/L). Oxidative stress was evaluated by tert-butyl hydroperoxide-initiated chemiluminescence (CL-LOOH), advanced oxidation protein products (AOPP), carbonyl protein, nitric oxide metabolites (NOx), sulfhydryl groups of protein and total radical-trapping antioxidant parameter (TRAP). MS patients with elevated levels of ferritin showed higher disease progression (p=0.030), AOPP (p=0.001), and lower plasma NOx levels (p=0.031) and TRAP (p=0.006) than MS patients with lower ferritin levels. The multivariate binary logistic regression analysis showed that increased AOPP and progression of disease were significantly and positively associated with increase of ferritin. The combination of serum ferritin levels and oxidative stress markers were responsible for 13,9% in the disease progression. In conclusion, our results suggest that ferritin could aggravate oxidative stress in patients with MS and contribute to progression of disease. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. An investigation of molybdenum and molybdenum oxide catalyzed hydrocarbon formation reactions. Progress report, August 1, 1992--April 1, 1993

    SciTech Connect

    Not Available

    1993-07-01

    Progress was made in the following four areas: activity of model catalyst (Mo oxides) for olefin metathesis (2 C{sub 3}H{sub 6} {r_arrow} C{sub 4}H{sub 8} + C{sub 2}H{sub 4}); kinetics of Mo(100)-catalyzed olefin metathesis; surface chemistry of ethylene oxide on Pd(111); and uv source construction.

  14. Recent progress on minor-actinide-bearing oxide fuel fabrication at CEA Marcoule

    NASA Astrophysics Data System (ADS)

    Lebreton, Florent; Prieur, Damien; Horlait, Denis; Delahaye, Thibaud; Jankowiak, Aurélien; Léorier, Caroline; Jorion, Frédéric; Gavilan, Elisabeth; Desmoulière, François

    2013-07-01

    Partitioning and transmutation (P&T) of minor actinides (MA: americium, neptunium and curium) in fast neutron reactors or accelerator-driven systems is a route envisaged to reduce nuclear waste inventory. Over the years, several modes of P&T were proposed, each being based on the use of dedicated fuels such as inert-matrix fuels, MA-bearing MOX or MA-bearing blankets. In this context, progress on the manufacturing of such fuels is a key-challenge in order to render P&T viable at the industrial scale. Here, MA-bearing oxide fuel fabrication and characterization conducted in the CEA Marcoule Atalante facility is reviewed. A particular attention is also given to the research conducted on uranium-americium mixed-oxides fuels, which are now considered the reference fuels for MA transmutation in France.

  15. Recent progress and perspectives in the photocatalytic CO2 reduction of Ti-oxide-based nanomaterials

    NASA Astrophysics Data System (ADS)

    Sohn, Youngku; Huang, Weixin; Taghipour, Fariborz

    2017-02-01

    The conversion of CO2 with H2O to valuable chemicals and fuels is a new solution to current environmental and energy problems, and the high energy barrier of these reactions can be overcome by the input of solar and electrical energy. However, the reduction efficiencies and selectivities of these reactions are insufficient for practical use, and significant effort and strategy are required to overcome the many obstacles preventing the large-scale application of photocatalytic CO2 reduction. This article reviews recent progress in CO2 reduction using titanium oxide-based materials and various strategic factors for increasing photocatalytic efficiency. This article also highlights non-titanium-oxide catalysts, the photoelectrocatalytic reduction of CO2, and other recent review articles concerning the recycling of CO2 to value-added carbon compounds.

  16. Transforming Growth Factor-Beta and Oxidative Stress Interplay: Implications in Tumorigenesis and Cancer Progression

    PubMed Central

    Krstić, Jelena; Trivanović, Drenka; Mojsilović, Slavko; Santibanez, Juan F.

    2015-01-01

    Transforming growth factor-beta (TGF-β) and oxidative stress/Reactive Oxygen Species (ROS) both have pivotal roles in health and disease. In this review we are analyzing the interplay between TGF-β and ROS in tumorigenesis and cancer progression. They have contradictory roles in cancer progression since both can have antitumor effects, through the induction of cell death, senescence and cell cycle arrest, and protumor effects by contributing to cancer cell spreading, proliferation, survival, and metastasis. TGF-β can control ROS production directly or by downregulating antioxidative systems. Meanwhile, ROS can influence TGF-β signaling and increase its expression as well as its activation from the latent complex. This way, both are building a strong interplay which can be taken as an advantage by cancer cells in order to increment their malignancy. In addition, both TGF-β and ROS are able to induce cell senescence, which in one way protects damaged cells from neoplastic transformation but also may collaborate in cancer progression. The mutual collaboration of TGF-β and ROS in tumorigenesis is highly complex, and, due to their differential roles in tumor progression, careful consideration should be taken when thinking of combinatorial targeting in cancer therapies. PMID:26078812

  17. Progress with the development of a CO 2 capturing solid oxide fuel cell

    NASA Astrophysics Data System (ADS)

    Haines, M. R.; Heidug, W. K.; Li, K. J.; Moore, J. B.

    In April 2000 Siemens Westinghouse started work under a co-operation agreement with Shell International to develop and demonstrate a natural gas fired 0.25 MW solid oxide fuel cell (SOFC) modified to enable capture of carbon dioxide. The basic principles of this development and initial plans for the demonstration, which is due to start up at a Norwegian location in 2003, have been presented in environmental and fuel cell forums during 1999/2000. This paper reviews the latest technical progress with this development and discusses the large potential market for stationary power generation using SOFCs with CO 2 capturing capability.

  18. Progressive breakdown dynamics and entropy production in ultrathin SiO2 gate oxides

    NASA Astrophysics Data System (ADS)

    Miranda, E.; Jiménez, D.; Suñé, J.

    2011-06-01

    The progressive breakdown of ultrathin (≈2nm) SiO2 gate oxides subjected to constant electrical stress is investigated using a simple equivalent circuit model. It is shown how the interplay among series, parallel, and filamentary conductances that represent the breakdown path and its surroundings leads under certain hypothesis to a sigmoidal current-time characteristic compatible with the experimental observations. The dynamical properties of the breakdown trajectories are analyzed in terms of the logistic potential function, the Lyapunov exponent, and the system's attractor. It is also shown that the current evolution is compatible with Prigogine's minimum entropy production principle.

  19. The Potential Role of Nitric Oxide in Halting Cancer Progression Through Chemoprevention

    PubMed Central

    Vahora, Huzefa; Khan, Munawwar Ali; Alalami, Usama; Hussain, Arif

    2016-01-01

    Nitric oxide (NO) in general plays a beneficial physiological role as a vasorelaxant and the role of NO is decided by its concentration present in physiological environments. NO either facilitates cancer-promoting characters or act as an anti-cancer agent. The dilemma in this regard still remains unanswered. This review summarizes the recent information on NO and its role in carcinogenesis and tumor progression, as well as dietary chemopreventive agents which have NO-modulating properties with safe cytotoxic profile. Understanding the molecular mechanisms and cross-talk modulating NO effect by these chemopreventive agents can allow us to develop better therapeutic strategies for cancer treatment. PMID:27051643

  20. Progress in the development of semiconducting metal oxide gas sensors: a review

    NASA Astrophysics Data System (ADS)

    Moseley, Patrick T.

    2017-08-01

    Since the first suggestion, during the 1950s, that high-surface-area metal oxides could be used as conductometric gas sensors enormous efforts have been made to enhance both the selectivity and the sensitivity of such devices, and to reduce their operational power requirements. This development has involved the exploration of response mechanisms, the selection of the most appropriate oxide compositions, the fabrication of two-phase ‘hetero-structures’, the addition of metallic catalyst particles and the optimisation of the manner in which the materials are presented to the gas—the structure and the nanostructure of the sensing elements. Far more of the scientific literature has been devoted to seeking such improvements in metal oxide gas sensors than has been directed at all other solid-state gas sensors together. Recent progress in the research and development of metal oxide gas sensor technology is surveyed in this invited review. The advances that have been made are quite spectacular and the results of individual pieces of work are drawn together here so that trends can be seen. Emerging features include: the significance of n-type/p-type switching, the enhancement of sensing performance of materials through the incorporation of secondary components and the advantages of interrogating sensors with alternating current rather than direct current.

  1. Increased palmitate intake: higher acylcarnitine concentrations without impaired progression of β-oxidation1[S

    PubMed Central

    Kien, C. Lawrence; Matthews, Dwight E.; Poynter, Matthew E.; Bunn, Janice Y.; Fukagawa, Naomi K.; Crain, Karen I.; Ebenstein, David B.; Tarleton, Emily K.; Stevens, Robert D.; Koves, Timothy R.; Muoio, Deborah M.

    2015-01-01

    Palmitic acid (PA) is associated with higher blood concentrations of medium-chain acylcarnitines (MCACs), and we hypothesized that PA may inhibit progression of FA β-oxidation. Using a cross-over design, 17 adults were fed high PA (HPA) and low PA/high oleic acid (HOA) diets, each for 3 weeks. The [1-13C]PA and [13-13C]PA tracers were administered with food in random order with each diet, and we assessed PA oxidation (PA OX) and serum AC concentration to determine whether a higher PA intake promoted incomplete PA OX. Dietary PA was completely oxidized during the HOA diet, but only about 40% was oxidized during the HPA diet. The [13-13C]PA/[1-13C]PA ratio of PA OX had an approximate value of 1.0 for either diet, but the ratio of the serum concentrations of MCACs to long-chain ACs (LCACs) was significantly higher during the HPA diet. Thus, direct measurement of PA OX did not confirm that the HPA diet caused incomplete PA OX, despite the modest, but statistically significant, increase in the ratio of MCACs to LCACs in blood. PMID:26156077

  2. Recent progress in tungsten oxides based memristors and their neuromorphological applications

    NASA Astrophysics Data System (ADS)

    Qu, Bo; Younis, Adnan; Chu, Dewei

    2016-09-01

    The advance in conventional silicon based semiconductor industry is now becoming indeterminacy as it still along the road of Moore's Law and concomitant problems associated with it are the emergence of a number of practical issues such as short channel effect. In terms of memory applications, it is generally believed that transistors based memory devices will approach to their scaling limits up to 2018. Therefore, one of the most prominent challenges today in semiconductor industry is the need of a new memory technology which is able to combine the best characterises of current devices. The resistive switching memories which are regarded as "memristors" thus gain great attentions thanks to their specific nonlinear electrical properties. More importantly, their behaviour resembles with the transmission characteristic of synapse in biology. Therefore, the research of synapses biomimetic devices based on memristor will certainly bring a great research prospect in studying synapse emulation as well as building artificial neural networks. Tungsten oxides (WO x ) exhibits many essential characteristics as a great candidate for memristive devices including: accredited endurance (over 105 cycles), stoichiometric flexibility, complimentary metal-oxide-semiconductor (CMOS) process compatibility and configurable properties including non-volatile rectification, memorization and learning functions. Herein, recent progress on Tungsten oxide based materials and its associating memory devices had been reviewed. The possible implementation of this material as a bio-inspired artificial synapse is also highlighted. The penultimate section summaries the current research progress for tungsten oxide based biological synapses and end up with several proposals that have been suggested for possible future developments.

  3. Cuprous oxide nanoparticle-inhibited melanoma progress by targeting melanoma stem cells

    PubMed Central

    Yu, Bin; Wang, Ye; Yu, Xinlu; Zhang, Hongxia; Zhu, Ji; Wang, Chen; Chen, Fei; Liu, Changcheng; Wang, Jingqiang; Zhu, Haiying

    2017-01-01

    Recent studies have shown that metal and metal oxide have a potential function in antitumor therapy. Our previous studies demonstrated that cuprous oxide nanoparticles (CONPs) not only selectively induce apoptosis of tumor cells in vitro but also inhibit the growth and metastasis of melanoma by targeting mitochondria with little hepatic and renal toxicities in mice. As a further study, our current research revealed that CONPs induced apoptosis of human melanoma stem cells (CD271+/high cells) in A375 and WM266-4 melanoma cell lines and could significantly suppress the expression of MITF, SOX10 and CD271 involved in the stemness maintenance and tumorigenesis of melanoma stem cells. CD271+/high cells could accumulate more CONPs than CD271−/low through clathrin-mediated endocytosis. In addition, lower dosage of CONPs exhibited good anti-melanoma effect by decreasing the cell viability, stemness and tumorigenesis of A375 and WM266-4 cells through reducing the expression of SOX10, MITF, CD271 and genes in MAPK pathway involved in tumor progression. Finally, CONPs obviously suppressed the growth of human melanoma in tumor-bearing nonobese diabetic-severe combined immunodeficiency (NOD-SCID) mice, accompanied with tumors structural necrosis and fibrosis remarkably and decreased expression of CD271, SOX10 and MITF. These results above proved the effectiveness of CONPs in inhibiting melanoma progress through multiple pathways, especially through targeting melanoma stem cells. PMID:28435246

  4. Cuprous oxide nanoparticle-inhibited melanoma progress by targeting melanoma stem cells.

    PubMed

    Yu, Bin; Wang, Ye; Yu, Xinlu; Zhang, Hongxia; Zhu, Ji; Wang, Chen; Chen, Fei; Liu, Changcheng; Wang, Jingqiang; Zhu, Haiying

    2017-01-01

    Recent studies have shown that metal and metal oxide have a potential function in antitumor therapy. Our previous studies demonstrated that cuprous oxide nanoparticles (CONPs) not only selectively induce apoptosis of tumor cells in vitro but also inhibit the growth and metastasis of melanoma by targeting mitochondria with little hepatic and renal toxicities in mice. As a further study, our current research revealed that CONPs induced apoptosis of human melanoma stem cells (CD271(+/high) cells) in A375 and WM266-4 melanoma cell lines and could significantly suppress the expression of MITF, SOX10 and CD271 involved in the stemness maintenance and tumorigenesis of melanoma stem cells. CD271(+/high) cells could accumulate more CONPs than CD271(-/low) through clathrin-mediated endocytosis. In addition, lower dosage of CONPs exhibited good anti-melanoma effect by decreasing the cell viability, stemness and tumorigenesis of A375 and WM266-4 cells through reducing the expression of SOX10, MITF, CD271 and genes in MAPK pathway involved in tumor progression. Finally, CONPs obviously suppressed the growth of human melanoma in tumor-bearing nonobese diabetic-severe combined immunodeficiency (NOD-SCID) mice, accompanied with tumors structural necrosis and fibrosis remarkably and decreased expression of CD271, SOX10 and MITF. These results above proved the effectiveness of CONPs in inhibiting melanoma progress through multiple pathways, especially through targeting melanoma stem cells.

  5. Nanochips of Tantalum Oxide Nanodots as artificial-microenvironments for monitoring Ovarian cancer progressiveness

    NASA Astrophysics Data System (ADS)

    Dhawan, Udesh; Wang, Ssu-Meng; Chu, Ying Hao; Huang, Guewha S.; Lin, Yan Ren; Hung, Yao Ching; Chen, Wen Liang

    2016-08-01

    Nanotopography modulates cell characteristics and cell behavior. Nanotopological cues can be exploited to investigate the in-vivo modulation of cell characteristics by the cellular microenvironment. However, the studies explaining the modulation of tumor cell characteristics and identifying the transition step in cancer progressiveness are scarce. Here, we engineered nanochips comprising of Tantalum oxide nanodot arrays of 10, 50, 100 and 200 nm as artificial microenvironments to study the modulation of cancer cell behavior. Clinical samples of different types of Ovarian cancer at different stages were obtained, primary cultures were established and then seeded on different nanochips. Immunofluorescence (IF) was performed to compare the morphologies and cell characteristics. Indices corresponding to cell characteristics were defined. A statistical comparison of the cell characteristics in response to the nanochips was performed. The cells displayed differential growth parameters. Morphology, Viability, focal adhesions, microfilament bundles and cell area were modulated by the nanochips which can be used as a measure to study the cancer progressiveness. The ease of fabrication of nanochips ensures mass-production. The ability of the nanochips to act as artificial microenvironments and modulate cell behavior may lead to further prospects in the markerless monitoring of the progressiveness and ultimately, improving the prognosis of Ovarian cancer.

  6. Nanochips of Tantalum Oxide Nanodots as artificial-microenvironments for monitoring Ovarian cancer progressiveness

    PubMed Central

    Dhawan, Udesh; Wang, Ssu-Meng; Chu, Ying Hao; Huang, Guewha S.; Lin, Yan Ren; Hung, Yao Ching; Chen, Wen Liang

    2016-01-01

    Nanotopography modulates cell characteristics and cell behavior. Nanotopological cues can be exploited to investigate the in-vivo modulation of cell characteristics by the cellular microenvironment. However, the studies explaining the modulation of tumor cell characteristics and identifying the transition step in cancer progressiveness are scarce. Here, we engineered nanochips comprising of Tantalum oxide nanodot arrays of 10, 50, 100 and 200 nm as artificial microenvironments to study the modulation of cancer cell behavior. Clinical samples of different types of Ovarian cancer at different stages were obtained, primary cultures were established and then seeded on different nanochips. Immunofluorescence (IF) was performed to compare the morphologies and cell characteristics. Indices corresponding to cell characteristics were defined. A statistical comparison of the cell characteristics in response to the nanochips was performed. The cells displayed differential growth parameters. Morphology, Viability, focal adhesions, microfilament bundles and cell area were modulated by the nanochips which can be used as a measure to study the cancer progressiveness. The ease of fabrication of nanochips ensures mass-production. The ability of the nanochips to act as artificial microenvironments and modulate cell behavior may lead to further prospects in the markerless monitoring of the progressiveness and ultimately, improving the prognosis of Ovarian cancer. PMID:27534915

  7. Recent Progress in Self‐Supported Metal Oxide Nanoarray Electrodes for Advanced Lithium‐Ion Batteries

    PubMed Central

    Zhang, Feng

    2016-01-01

    The rational design and fabrication of electrode materials with desirable architectures and optimized properties has been demonstrated to be an effective approach towards high‐performance lithium‐ion batteries (LIBs). Although nanostructured metal oxide electrodes with high specific capacity have been regarded as the most promising alternatives for replacing commercial electrodes in LIBs, their further developments are still faced with several challenges such as poor cycling stability and unsatisfying rate performance. As a new class of binder‐free electrodes for LIBs, self‐supported metal oxide nanoarray electrodes have many advantageous features in terms of high specific surface area, fast electron transport, improved charge transfer efficiency, and free space for alleviating volume expansion and preventing severe aggregation, holding great potential to solve the mentioned problems. This review highlights the recent progress in the utilization of self‐supported metal oxide nanoarrays grown on 2D planar and 3D porous substrates, such as 1D and 2D nanostructure arrays, hierarchical nanostructure arrays, and heterostructured nanoarrays, as anodes and cathodes for advanced LIBs. Furthermore, the potential applications of these binder‐free nanoarray electrodes for practical LIBs in full‐cell configuration are outlined. Finally, the future prospects of these self‐supported nanoarray electrodes are discussed. PMID:27711259

  8. Recent Progress in Self-Supported Metal Oxide Nanoarray Electrodes for Advanced Lithium-Ion Batteries.

    PubMed

    Zhang, Feng; Qi, Limin

    2016-09-01

    The rational design and fabrication of electrode materials with desirable architectures and optimized properties has been demonstrated to be an effective approach towards high-performance lithium-ion batteries (LIBs). Although nanostructured metal oxide electrodes with high specific capacity have been regarded as the most promising alternatives for replacing commercial electrodes in LIBs, their further developments are still faced with several challenges such as poor cycling stability and unsatisfying rate performance. As a new class of binder-free electrodes for LIBs, self-supported metal oxide nanoarray electrodes have many advantageous features in terms of high specific surface area, fast electron transport, improved charge transfer efficiency, and free space for alleviating volume expansion and preventing severe aggregation, holding great potential to solve the mentioned problems. This review highlights the recent progress in the utilization of self-supported metal oxide nanoarrays grown on 2D planar and 3D porous substrates, such as 1D and 2D nanostructure arrays, hierarchical nanostructure arrays, and heterostructured nanoarrays, as anodes and cathodes for advanced LIBs. Furthermore, the potential applications of these binder-free nanoarray electrodes for practical LIBs in full-cell configuration are outlined. Finally, the future prospects of these self-supported nanoarray electrodes are discussed.

  9. Kefir administration reduced progression of renal injury in STZ-diabetic rats by lowering oxidative stress.

    PubMed

    Punaro, Giovana R; Maciel, Fabiane R; Rodrigues, Adelson M; Rogero, Marcelo M; Bogsan, Cristina S B; Oliveira, Marice N; Ihara, Silvia S M; Araujo, Sergio R R; Sanches, Talita R C; Andrade, Lucia C; Higa, Elisa M S

    2014-02-15

    This study aimed at assessing the effects of Kefir, a probiotic fermented milk, on oxidative stress in diabetic animals. The induction of diabetes was achieved in adult male Wistar rats using streptozotocin (STZ). The animals were distributed into four groups as follows: control (CTL); control Kefir (CTLK); diabetic (DM) and diabetic Kefir (DMK). Starting on the 5th day of diabetes, Kefir was administered by daily gavage at a dose of 1.8 mL/day for 8 weeks. Before and after Kefir treatment, the rats were placed in individual metabolic cages to obtain blood and urine samples to evaluate urea, creatinine, proteinuria, nitric oxide (NO), thiobarbituric acid reactive substances (TBARS) and C-reactive protein (CRP). After sacrificing the animals, the renal cortex was removed for histology, oxidative stress and NOS evaluation. When compared to CTL rats, DM rats showed increased levels of glycemia, plasmatic urea, proteinuria, renal NO, superoxide anion, TBARS, and plasmatic CRP; also demonstrated a reduction in urinary urea, creatinine, and NO. However, DMK rats showed a significant improvement in most of these parameters. Despite the lack of differences observed in the expression of endothelial NO synthase (eNOS), the expression of inducible NO synthase (iNOS) was significantly lower in the DMK group when compared to DM rats, as assessed by Western blot analysis. Moreover, the DMK group presented a significant reduction of glycogen accumulation within the renal tubules when compared to the DM group. These results indicate that Kefir treatment may contribute to better control of glycemia and oxidative stress, which is associated with the amelioration of renal function, suggesting its use as a non-pharmacological adjuvant to delay the progression of diabetic complications. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Surface properties of photo-oxidized bituminous coals. Technical progress report, January--March 1996

    SciTech Connect

    Mitchell, G.; Davis, A.; Chander, S.

    1996-12-31

    During this report period, a vitrinite concentrate from the mvb Splash Dam seam (DECS-30) was prepared and analyzed. Results show that the concentrate was 91 vol % vitrinite and that the sample has been adequately protected from oxidation under refrigerated storage in argon. The 9% level of contamination within the vitrinite resulted from the extreme friability of the coal and to the dispersion of fine grains of semifusinite and micrinite. Polished blocks containing vitrain bands that were prepared, irradiated in blue-light and employed in contact angle measurements were evaluated using specular reflectance-mode FT-IR for changes in functional group chemistry. Infrared spectra from unexposed areas of vitrinite and those irradiated for 1, 5 and 10 min for six coals ranging in rank from hvCb to mvb were obtained using a FTS 175 spectrometer with a Bio-Rad UMA 500 microscope accessory. Preliminary results demonstrate that photo-oxidation occurred during irradiation, becoming progressively more intense with increasing irradiation time; however, the magnitude of this change diminished with increasing rank. A relatively steady increase in the carbonyl region (1,800--1,650 cm{sup {minus}1}) and a decrease in the aliphatic region (2,950--2,850 cm{sup {minus}1}) of the spectra supports this observation and is similar to observations made in the past for natural weathering and laboratory oxidation of coals. A series of tests was initiated to photo-oxidize powdered vitrains using the BLAK-RAY ultraviolet lamp evaluated last quarter. Samples of four vitrinite concentrates were exposed to UV light for 10 mins per side. These and the corresponding whole-seam channel samples and raw vitrinite concentrates were submitted for initial microflotation tests which have not been completed at this time.

  11. Advanced experimental analysis of controls on microbial Fe(III) oxide reduction. First year progress report

    SciTech Connect

    Roden, E.E.; Urrutia, M.M.

    1997-07-01

    'The authors have made considerable progress toward a number of project objectives during the first several months of activity on the project. An exhaustive analysis was made of the growth rate and biomass yield (both derived from measurements of cell protein production) of two representative strains of Fe(III)-reducing bacteria (Shewanellaalga strain BrY and Geobactermetallireducens) growing with different forms of Fe(III) as an electron acceptor. These two fundamentally different types of Fe(III)-reducing bacteria (FeRB) showed comparable rates of Fe(III) reduction, cell growth, and biomass yield during reduction of soluble Fe(III)-citrate and solid-phase amorphous hydrous ferric oxide (HFO). Intrinsic growth rates of the two FeRB were strongly influenced by whether a soluble or a solid-phase source of Fe(III) was provided: growth rates on soluble Fe(III) were 10--20 times higher than those on solid-phase Fe(III) oxide. Intrinsic FeRB growth rates were comparable during reduction of HF0 and a synthetic crystalline Fe(III) oxide (goethite). A distinct lag phase for protein production was observed during the first several days of incubation in solid-phase Fe(III) oxide medium, even though Fe(III) reduction proceeded without any lag. No such lag between protein production and Fe(III) reduction was observed during growth with soluble Fe(III). This result suggested that protein synthesis coupled to solid-phase Fe(III) oxide reduction in batch culture requires an initial investment of energy (generated by Fe(III) reduction), which is probably needed for synthesis of materials (e.g. extracellular polysaccharides) required for attachment of the cells to oxide surfaces. This phenomenon may have important implications for modeling the growth of FeRB in subsurface sedimentary environments, where attachment and continued adhesion to solid-phase materials will be required for maintenance of Fe(III) reduction activity. Despite considerable differences in the rate and pattern

  12. Progress Toward a Molecular Mechanism of Water Oxidation in Photosystem II

    NASA Astrophysics Data System (ADS)

    Vinyard, David J.; Brudvig, Gary W.

    2017-05-01

    The active site of photosynthetic water oxidation is the oxygen-evolving complex (OEC) in the photosystem II (PSII) reaction center. The OEC is a Mn4CaO5 cluster embedded in the PSII protein matrix, and it cycles through redox intermediates known as Si states (i = 0-4). Significant progress has been made in understanding the inorganic and physical chemistry of states S0-S3 through experiment and theory. The chemical steps from S3 to S0 are more poorly understood, however, because the identity of the substrate water molecules and the mechanism of O-O bond formation are not well established. In this review, we highlight both the consensuses and the remaining challenges of PSII research.

  13. Fundamental chemistry and thermodynamics of hydrothermal oxidation processes. 1998 annual progress report

    SciTech Connect

    Simonson, J.M.; Mesmer, R.E.; Blencoe, J.G.; Cummings, P.T.; Chialvo, A.A.

    1998-06-01

    'The objective of this research program is to provide fundamental scientific information on the physical and chemical properties of solutes in aqueous solutions at high temperatures needed to assess and enhance the applicability of hydrothermal oxidation (HTO) to the remediation of DOE hazardous and mixed wastes. Potential limitations to the use of HTO technology include formation of deposits (scale) from precipitation of inorganic solutes in the waste, corrosion arising from formation of strong acids on oxidation of some organic compounds (e.g., chlorinated hydrocarbons), and unknown effects of fluid density and phase behavior at high temperatures. Focus areas for this project include measurements of the solubility and speciation of actinides and surrogates in model HTO process streams at high temperatures, and the experimental and theoretical development of equations of state for aqueous mixtures under HTO process conditions ranging above the critical temperature of water. A predictive level of understanding of the chemical and physical properties of HTO process streams is being developed through molecular-level simulations of aqueous solutions at high temperatures. Advances in fundamental understanding of phase behavior, density, and solute speciation at high temperatures and pressures contribute directly to the ultimate applicability of this process for the treatment of DOE hazardous and mixed wastes. Research in this project has been divided into individual tasks, with each contributing to a unified understanding of HTO processing problems related to the treatment of DOE wastes. This report summarizes progress attained after slightly less than two years of this three-year project.'

  14. Tin oxide as a photoanode for dye-sensitised solar cells: Current progress and future challenges

    NASA Astrophysics Data System (ADS)

    Wali, Qamar; Fakharuddin, Azhar; Jose, Rajan

    2015-10-01

    Tin oxide (SnO2) is a candidate for applications requiring high electrical conductivity and optical transparency, such as a photoanode in dye-sensitised solar cells (DSSCs), due to its higher electron mobility and wider optical transparency than many other metal oxide semiconductors (MOS), such as TiO2 and ZnO. However, DSSCs employing SnO2 show significantly lower photoconversion efficiency, compared to that achieved by popular choices, such as TiO2, due to its intrinsic limitations such as lower conduction band energy and isoelectric point. A survey of literature shows a revived interest in SnO2-based DSSCs, for example, strategies to (i) increase the dye uptake, (ii) increase its Fermi energy level, and (iii) reduce the recombination, such as by increasing surface roughness and novel morphologies towards (i), and doping of transition metals for (ii) and (iii). In response to these improvements, SnO2-based DSSCs showed similar open circuit voltage and superior short circuit current to that achieved by TiO2. We have undertaken a critical review on the progress made in overcoming the limitations and capitalising the advantages of SnO2 to fabricate more efficient DSSCs. We identify that more investment is required to reduce the recombination in SnO2 for it to emerge as an efficiency record holder in DSSCs.

  15. Amyloid β-Peptide (1–42)-Induced Oxidative Stress in Alzheimer Disease: Importance in Disease Pathogenesis and Progression

    PubMed Central

    Swomley, Aaron M.; Sultana, Rukhsana

    2013-01-01

    Abstract Significance: Alzheimer disease (AD) is an age-related neurodegenerative disease. AD is characterized by progressive cognitive impairment. One of the main histopathological hallmarks of AD brain is the presence of senile plaques (SPs) and another is elevated oxidative stress. The main component of SPs is amyloid beta-peptide (Aβ) that is derived from the proteolytic cleavage of amyloid precursor protein. Recent Advances: Recent studies are consistent with the notion that methionine present at 35 position of Aβ is critical to Aβ-induced oxidative stress and neurotoxicity. Further, we also discuss the signatures of oxidatively modified brain proteins, identified using redox proteomics approaches, during the progression of AD. Critical Issues: The exact relationships of the specifically oxidatively modified proteins in AD pathogenesis require additional investigation. Future Directions: Further studies are needed to address whether the therapies directed toward brain oxidative stress and oxidatively modified key brain proteins might help delay or prevent the progression of AD. Antioxid. Redox Signal. 19, 823–835. PMID:23249141

  16. Lactobacillus acidophilus ATCC 4356 attenuates the atherosclerotic progression through modulation of oxidative stress and inflammatory process.

    PubMed

    Chen, Lihua; Liu, Wenen; Li, Yanming; Luo, San; Liu, Qingxia; Zhong, Yiming; Jian, Zijuan; Bao, Meihua

    2013-09-01

    The aim of this study was to investigate the effect of Lactobacillus (L.) acidophilus ATCC 4356 on the progression of atherosclerosis in Apoliprotein-E knockout (ApoE(-/-)) mice and the underlying mechanisms. Eight week-old ApoE(-/-) mice were treated with L. acidophilus ATCC 4356 daily for 12 weeks. The wild type (WT) mice or ApoE(-/-) mice in the vehicle group were treated with saline only. Body weights, serum lipid levels, aortic atherosclerotic lesions, and tissue oxidative and inflammatory statuses were examined among the groups. As compared to ApoE(-/-) mice in the vehicle group, ApoE(-/-) mice treated with L. acidophilus ATCC 4356 had no changes in body weights and serum lipid profiles, but showed decreased atherosclerotic lesion size in en face aorta. In comparison with WT mice, ApoE(-/-) mice in the vehicle group showed higher levels of serum malondialdehyde (MDA), oxidized low density lipoprotein (oxLDL) and tumor necrosis factor-alpha (TNF-α), but lower levels of interleukin-10 (IL-10) and superoxide dismutase (SOD) activities in serum. Administration of L. acidophilus ATCC 4356 could reverse these trends in a dose-dependent manner in ApoE(-/-) mice. Furthermore, ApoE(-/-) mice treated with L. acidophilus ATCC 4356 showed an inhibition of translocation of NF-κB p65 from cytoplasm to nucleus, suppression of degradation of aortic IκB-α, and improvements of gut microbiota distribution, as compared to ApoE(-/-) mice in the vehicle group. Our findings suggest that administration of L. acidophilus ATCC 4356 can attenuate the development of atherosclerotic lesions in ApoE(-/-) mice through reducing oxidative stress and inflammatory response. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Indium oxide (In2O3) nanoparticles induce progressive lung injury distinct from lung injuries by copper oxide (CuO) and nickel oxide (NiO) nanoparticles.

    PubMed

    Jeong, Jiyoung; Kim, Jeongeun; Seok, Seung Hyeok; Cho, Wan-Seob

    2016-04-01

    Indium is an essential element in the manufacture of liquid crystal displays and other electronic devices, and several forms of indium compounds have been developed, including nanopowders, films, nanowires, and indium metal complexes. Although there are several reports on lung injury caused by indium-containing compounds, the toxicity of nanoscale indium oxide (In2O3) particles has not been reported. Here, we compared lung injury induced by a single exposure to In2O3 nanoparticles (NPs) to that caused by benchmark high-toxicity nickel oxide (NiO) and copper oxide (CuO) NPs. In2O3 NPs at doses of 7.5, 30, and 90 cm(2)/rat (50, 200, and 600 µg/rat) were administered to 6-week-old female Wistar rats via pharyngeal aspiration, and lung inflammation was evaluated 1, 3, 14, and 28 days after treatment. Neutrophilic inflammation was observed on day 1 and worsened until day 28, and severe pulmonary alveolar proteinosis (PAP) was observed on post-aspiration days 14 and 28. In contrast, pharyngeal aspiration of NiO NPs showed severe neutrophilic inflammation on day 1 and lymphocytic inflammation with PAP on day 28. Pharyngeal aspiration of CuO NPs showed severe neutrophilic inflammation on day 1, but symptoms were completely resolved after 14 days and no PAP was observed. The dose of In2O3 NPs that produced progressive neutrophilic inflammation and PAP was much less than the doses of other toxic particles that produced this effect, including crystalline silica and NiO NPs. These results suggest that occupational exposure to In2O3 NPs can cause severe lung injury.

  18. Model catalytic oxidation studies using supported monometallic and heterobimetallic oxides. Progress report, August 1, 1991--January 31, 1992

    SciTech Connect

    Ekerdt, J.G.

    1992-02-03

    This research program is directed toward a more fundamental understanding of the effects of catalyst composition and structure on the catalytic properties of metal oxides. Metal oxide catalysts play an important role in many reactions bearing on the chemical aspects of energy processes. Metal oxides are the catalysts for water-gas shift reactions, methanol and higher alcohol synthesis, isosynthesis, selective catalytic reduction of nitric oxides, and oxidation of hydrocarbons. A key limitation to developing insight into how oxides function in catalytic reactions is in not having precise information of the surface composition under reaction conditions. To address this problem we have prepared oxide systems that can be used to study cation-cation effects and the role of bridging (-O-) and/or terminal (=O) surface oxygen anion ligands in a systematic fashion. Since many oxide catalyst systems involve mixtures of oxides, we selected a model system that would permit us to examine the role of each cation separately and in pairwise combinations. Organometallic molybdenum and tungsten complexes were proposed for use, to prepare model systems consisting of isolated monomeric cations, isolated monometallic dimers and isolated bimetallic dimers supported on silica and alumina. The monometallic and bimetallic dimers were to be used as models of more complex mixed- oxide catalysts. Our current program was to develop the systems and use them in model oxidation reactions.

  19. MRI study of atherosclerotic plaque progression using ultrasmall superparamagnetic iron oxide in Watanabe heritable hyperlipidemic rabbits.

    PubMed

    Kaneko, C; Nitta, N; Tsuchiya, K; Watanabe, S; Nitta-Seko, A; Ohta, S; Otani, H; Sonoda, A; Murata, K; Shiomi, M

    2015-09-01

    The purpose of this study was to evaluate plaque progression by using MRI with ultrasmall superparamagnetic iron oxide (USPIO) and by histopathological studies. We divided 12 Watanabe heritable hyperlipidemic (WHHL) rabbits into 4 groups based on their age (3, 9, 14 and 26 months) and injected them intravenously with 0.8 mmol (Fe) kg(-1) of USPIO (size, 32 nm; concentration, 15 mg dl(-1)). On the fifth post-injection day, they were again given an intravenous injection with 40 μmol kg(-1) of the same USPIO, and MR angiography (MRA) was performed. The signal-to-noise ratio (SNR) in regions of interest in the wall of the upper abdominal aorta was calculated on coronal images. Specimens from the same level of the aorta were subjected to iron staining and RAM-11 immunostaining and used for histopathological study. For statistical analysis of the MRA and histopathological findings, we used analysis of variance [Tukey's honest significant difference (HSD) test]. In 9-month-old rabbits, the SNR was significantly lower than in rabbits of the other ages (p < 0.01), and the area of RAM-11 (DAKO Corporation, Glostrup, Denmark) and iron uptake in the aortic wall was significantly larger (RAM-11, p < 0.01; iron, p < 0.05). These areas were the smallest in 3-month-old rabbits. Histopathologically, the number of macrophages was the greatest in 9-month-old rabbits. Our findings indicate that the SNR on MRI scans reflects the number of macrophages in the aortic wall of WHHL rabbits. USPIO-enhanced MRI visualized the accumulation of macrophages in early atherosclerotic plaques of WHHL rabbits in the course of natural progression.

  20. Contribution of nitric oxide to brachial artery vasodilation during progressive handgrip exercise in the elderly

    PubMed Central

    Wray, D. Walter; Witman, Melissa A. H.; Layec, Gwenael; Barrett-O'Keefe, Zachary; Ives, Stephen J.; Conklin, Jamie D.; Reese, Van; Richardson, Russell S.

    2013-01-01

    The reduction in nitric oxide (NO)-mediated vascular function with age has largely been determined by flow-mediated dilation (FMD). However, in light of recent uncertainty surrounding the NO dependency of FMD and the recognition that brachial artery (BA) vasodilation during handgrip exercise is predominantly NO-mediated in the young, we sought to determine the contribution of NO to BA vasodilation in the elderly using the handgrip paradigm. BA vasodilation during progressive dynamic (1 Hz) handgrip exercise performed at 3, 6, 9, and 12 kg was assessed with and without NO synthase (NOS) inhibition [intra-arterial NG-monomethyl-l-arginine (l-NMMA)] in seven healthy older subjects (69 ± 2 yr). Handgrip exercise in the control condition evoked significant BA vasodilation at 6 (4.7 ± 1.4%), 9 (6.5 ± 2.2%), and 12 kg (9.5 ± 2.7%). NOS inhibition attenuated BA vasodilation, as the first measurable increase in BA diameter did not occur until 9 kg (4.0 ± 1.8%), and the change in BA diameter at 12 kg was reduced by ∼30% (5.1 ± 2.2%), with unaltered shear rate (Control: 407 ± 57, l-NMMA: 427 ± 67 s−1). Although shifted downward, the slope of the relationship between BA diameter and shear rate during handgrip exercise was unchanged (Control: 0.0013 ± 0.0004, l-NMMA: 0.0011 ± 0.007, P = 0.6) as a consequence of NOS inhibition. Thus, progressive handgrip exercise in the elderly evokes a robust BA vasodilation, the magnitude of which was only minimally attenuated following NOS inhibition. This modest contribution of NO to BA vasodilation in the elderly supports the use of the handgrip exercise paradigm to assess NO-dependent vasodilation across the life span. PMID:23948773

  1. Contribution of nitric oxide to brachial artery vasodilation during progressive handgrip exercise in the elderly.

    PubMed

    Trinity, Joel D; Wray, D Walter; Witman, Melissa A H; Layec, Gwenael; Barrett-O'Keefe, Zachary; Ives, Stephen J; Conklin, Jamie D; Reese, Van; Richardson, Russell S

    2013-10-15

    The reduction in nitric oxide (NO)-mediated vascular function with age has largely been determined by flow-mediated dilation (FMD). However, in light of recent uncertainty surrounding the NO dependency of FMD and the recognition that brachial artery (BA) vasodilation during handgrip exercise is predominantly NO-mediated in the young, we sought to determine the contribution of NO to BA vasodilation in the elderly using the handgrip paradigm. BA vasodilation during progressive dynamic (1 Hz) handgrip exercise performed at 3, 6, 9, and 12 kg was assessed with and without NO synthase (NOS) inhibition [intra-arterial N(G)-monomethyl-l-arginine (l-NMMA)] in seven healthy older subjects (69 ± 2 yr). Handgrip exercise in the control condition evoked significant BA vasodilation at 6 (4.7 ± 1.4%), 9 (6.5 ± 2.2%), and 12 kg (9.5 ± 2.7%). NOS inhibition attenuated BA vasodilation, as the first measurable increase in BA diameter did not occur until 9 kg (4.0 ± 1.8%), and the change in BA diameter at 12 kg was reduced by ∼30% (5.1 ± 2.2%), with unaltered shear rate ( 407 ± 57, l-NMMA: 427 ± 67 s(-1)). Although shifted downward, the slope of the relationship between BA diameter and shear rate during handgrip exercise was unchanged ( 0.0013 ± 0.0004, l-NMMA: 0.0011 ± 0.007, P = 0.6) as a consequence of NOS inhibition. Thus, progressive handgrip exercise in the elderly evokes a robust BA vasodilation, the magnitude of which was only minimally attenuated following NOS inhibition. This modest contribution of NO to BA vasodilation in the elderly supports the use of the handgrip exercise paradigm to assess NO-dependent vasodilation across the life span.

  2. Initial stages of oxidation of metals and alloys. Progress report, August 1, 1979-April 30, 1980

    SciTech Connect

    Blakely, J.M.

    1980-04-01

    An experimental research program on metal surface oxidation has been initiated. Studies of Be and of Fe-Ni single crystal surfaces are underway using the techniques of Auger and electron loss spectroscopy and low energy electron diffraction. A detailed study of the Auger line shape from clean cleaved Be (0001) planes has provided a standard against which all previous work may be composed. Progress has been made in preparing clean Be surfaces by ion sputtering techniques, computer processing of Auger data and some preliminary LEED studies have been made both of clean and oxygen covered surfaces. A liquid nitrogen cold stage for ribbon type single crystal samples has been constructed. The composition of the (100) surface of a Ni-60, Fe-40 single crystal has been in vestigated over the temperature range from 25 to 900/sup 0/C. Under uhv conditions only very slight enrichment in Fe occurs. Preliminary studies have also been made of surface structure and of C and S segregation to this Fe-Ni (100) surface.

  3. The Simultaneous Elevation of Oxidative Stress Markers and Wilms' Tumor 1 Gene during the Progression of Myelodysplastic Syndrome

    PubMed Central

    Shimizu, Naomi; Hasunuma, Hidekazu; Watanabe, Yasuhiro; Matsuzawa, Yasuo; Iwashita, Youichi; Tatsuno, Ichiro; Yokota, Hiromitsu

    2016-01-01

    Oxidative stress is closely related to iron overload in myelodysplastic syndrome (MDS) and induces DNA damage. We evaluated the oxidative stress markers derivatives of reactive oxidative metabolites (dROM) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) during azacitidine treatment in an MDS patient. Simultaneous with an increase in the expression of Wilms' Tumor 1 (WT1) gene in the peripheral blood, the serum dROM level was elevated, and this increase was observed earlier than the increases in ferritin and 8-OHdG. Throughout the clinical course, dROM and 8-OHdG correlated significantly with WT1 and with ferritin, suggesting that changes in the oxidative stress marker levels reflect not only iron overload but also disease progression of MDS. PMID:27980269

  4. Modeling Disease Progression: Angiotensin II Indirectly Inhibits Nitric Oxide Production via ADMA Accumulation in Spontaneously Hypertensive Rats

    PubMed Central

    Wang, Haidong; Jiang, Hao; Liu, Haochen; Zhang, Xue; Ran, Guimei; He, Hua; Liu, Xiaoquan

    2016-01-01

    Nitric oxide (NO) production impairment is involved in the onset and development of hypertension. Although NO production impairment in spontaneously hypertensive rat (SHR) has been reported in a variety of researches, the time course of this progressive procedure, as well as its relationship with asymmetric dimethylarginine (ADMA) and angiotensin II (Ang II), has not been quantified. The aim of this research is to establish a mechanism-based disease progression model to assess Ang II and ADMA's inhibition of NO production in SHR's disease progression with/without ramipril's intervention. SHR were randomly divided into three groups: one disease group (n = 8) and two treatment groups (n = 8 for each group): standard treatment group (receiving ramipril 2 mg/kg*day) and intensive treatment group (receiving ramipril 10 mg/kg*day). ADMA, Ang II, NO, and SBP were determined weekly. Intensive treatment with ramipril was found to have no further attenuation of plasma NO and ADMA than standard treatment beyond its significantly stronger antihypertensive effects. Four linked turnover models were developed to characterize the profiles of ADMA, Ang II, NO, and SBP during hypertensive disease progression with/without ramipril intervention. Our model described Ang II and ADMA's contribution to NO production impairment and their responses to ramipril treatment throughout the disease progression in SHR. Model simulations suggested that Ang II affected NO production mainly through inhibiting ADMA elimination rather than affecting nitric oxide synthase (NOS) directly. PMID:27909412

  5. Reduced progression of experimental osteoarthritis in vivo by selective inhibition of inducible nitric oxide synthase.

    PubMed

    Pelletier, J P; Jovanovic, D; Fernandes, J C; Manning, P; Connor, J R; Currie, M G; Di Battista, J A; Martel-Pelletier, J

    1998-07-01

    To evaluate the in vivo therapeutic efficacy of N-iminoethyl-L-lysine (L-NIL), a selective inhibitor of inducible nitric oxide synthase (iNOS), on the progression of lesions in an experimental osteoarthritis (OA) dog model. The effect of L-NIL on metalloprotease activity, levels of interleukin-1beta (IL-1beta), prostaglandin E2 (PGE2), and nitrite/nitrate in synovial fluid was determined. The OA model was created by sectioning the anterior cruciate ligament of the right stifle joint of mongrel dogs by a stab wound. Dogs were separated into experimental groups: Group 1 was made up of unoperated dogs that received no treatment, group 2 were operated dogs with no treatment, and group 3 were operated dogs that received oral L-NIL (10 mg/kg/twice daily) starting immediately after surgery. The OA dogs were killed at 10 weeks after surgery. Experiments showed that dog OA cartilage explants in culture produced an increased amount of NO (nitrite). Immunohistochemical study demonstrated that this was due to an increased level of iNOS in chondrocytes. OA dogs treated with L-NIL showed a reduction in the incidence of osteophytes compared with the untreated OA dogs (58% versus 92%) as well as in their size (mean +/- SEM 1.92 +/- 0.58 mm versus 5.08 +/- 0.66 mm). Macroscopically, L-NIL decreased the size of the cartilage lesions by approximately 50% both on condyles and plateaus. The histologic severity of both the cartilage lesions and synovial inflammation was significantly decreased in the L-NIL-treated dogs. Treatment with L-NIL also significantly decreased both collagenase and general metalloprotease activity in the cartilage and the levels of IL-1beta, PGE2, and nitrite/nitrate in synovial fluid. This study demonstrated the effectiveness of a selective inhibitor of iNOS, L-NIL, in attenuating the progression of experimental OA. The data suggest that L-NIL may act by reducing the activity of metalloproteases in cartilage and the production of IL-1beta by synovium, both of

  6. Controlling incipient oxidation of pyrite for improved rejection. Technical progress report for the ninth quarter, October 1--December 31, 1994

    SciTech Connect

    Yoon, R.H.; Richardson, P.E.

    1995-07-01

    The major objectives of this work are (1) to determine the Eh-pH conditions under which pyrite is stable, (2) to determine the mechanism of the initial stages of pyrite oxidation, and (3) to determine if the semi-conducting properties of pyrite effects its oxidation behavior. It is known that moderate oxidation of pyrite produces a hydrophobic surface product. This hydrophobic product makes it extremely difficult to depress pyrite in coal flotation circuits. The eventual objective of this work is to prevent pyrite oxidation in order to better depress pyrite in coal flotation circuits. It has been shown that by holding the potential of pyrite at its stable potential during fracture, pyrite undergoes neither oxidation nor reduction. It has also been found that fresh pyrite surfaces created by fracture in an electrochemical begin to oxidize at potentials that are about 200 mV more negative than the potentials reported in the literature for pyrite oxidation. This report period, electrochemical impedance spectroscopy (EIS) studies were continued. As discussed in the seventh quarterly progress report, the impedance of pyrite does not show the characteristics expected for either semi-conducting or metallic electrodes. Additional studies were conducted to confirm the anomalous impedance behavior. For this purpose, freshly fractured surfaces were progressively polished on 600 and 1,200 grit silicon carbide paper, and with 0.3 {micro} {alpha}-alumina and 0.05 {micro} {gamma}-alumina micropolish. Polishing is known to introduce defects in the lattice structure of semi-conducting electrodes and it was anticipated that the defects would effect the interfacial capacitance.

  7. Oxidative stress, progressive damage in the substantia nigra and plasma dopamine oxidation, in rats chronically exposed to ozone.

    PubMed

    Santiago-López, D; Bautista-Martínez, J A; Reyes-Hernandez, C I; Aguilar-Martínez, M; Rivas-Arancibia, S

    2010-09-01

    The purpose of our work was to determine the effects of oxidative stress on the neurodegeneration process in the substantia nigra, and to evaluate dopamine-oxidation metabolites in the plasma using a cyclic voltammetry (CV) technique. We have also studied the correlation between the increases in oxidized dopamine-species levels with the severity of lipid-peroxidation in the plasma. Sixty-four male Wistar rats were divided into four experimental groups and received air (Group I, control) or ozone (0.25 ppm) daily by inhalation for 4h for 15 (Group II), 30 (Group III), and 60 (Group IV) days. The brains were processed for immunohistochemical location of dopamine and p53 in the substantia nigra. Plasma collected from these animals was assayed for oxidized dopamine products using CV and lipid-peroxidation levels were measured. Our results indicate that chronic exposure to low O(3) doses causes that the number of dopaminergic neurons decreased, and p53-immunoreactive cells increases until 30 days; which was a function of the time of exposure to ozone. Oxidative stress produces a significant increase in the levels of the dopamine quinones (DAQs) that correlated well (r=0.962) with lipid peroxides in the plasma during the study period. These results suggest that DAQ could be a reliable, peripheral oxidative indicator of nigral dopaminergic damage in the brain. (c) 2010 Elsevier Ireland Ltd. All rights reserved.

  8. DNA damage signalling barrier, oxidative stress and treatment-relevant DNA repair factor alterations during progression of human prostate cancer.

    PubMed

    Kurfurstova, Daniela; Bartkova, Jirina; Vrtel, Radek; Mickova, Alena; Burdova, Alena; Majera, Dusana; Mistrik, Martin; Kral, Milan; Santer, Frederic R; Bouchal, Jan; Bartek, Jiri

    2016-06-01

    The DNA damage checkpoints provide an anti-cancer barrier in diverse tumour types, however this concept has remained unexplored in prostate cancer (CaP). Furthermore, targeting DNA repair defects by PARP1 inhibitors (PARPi) as a cancer treatment strategy is emerging yet requires suitable predictive biomarkers. To address these issues, we performed immunohistochemical analysis of multiple markers of DNA damage signalling, oxidative stress, DNA repair and cell cycle control pathways during progression of human prostate disease from benign hyperplasia, through intraepithelial neoplasia to CaP, complemented by genetic analyses of TMPRSS2-ERG rearrangement and NQO1, an anti-oxidant factor and p53 protector. The DNA damage checkpoint barrier (γH2AX, pATM, p53) mechanism was activated during CaP tumorigenesis, albeit less and with delayed culmination compared to other cancers, possibly reflecting lower replication stress (slow proliferation despite cases of Rb loss and cyclin D1 overexpression) and progressive loss of ATM activator NKX3.1. Oxidative stress (8-oxoguanine lesions) and NQO1 increased during disease progression. NQO1 genotypes of 390 men did not indicate predisposition to CaP, yet loss of NQO1 in CaP suggested potential progression-opposing tumour suppressor role. TMPRSS2-ERG rearrangement and PTEN loss, events sensitizing to PARPi, occurred frequently along with heterogeneous loss of DNA repair factors 53BP1, JMJD1C and Rev7 (all studied here for the first time in CaP) whose defects may cause resistance to PARPi. Overall, our results reveal an unorthodox DNA damage checkpoint barrier scenario in CaP tumorigenesis, and provide novel insights into oxidative stress and DNA repair, with implications for biomarker guidance of future targeted therapy of CaP.

  9. Oxidation of phenolics in supercritical water. Combined quarterly technical progress report, December 1, 1995--May 31, 1996

    SciTech Connect

    1996-11-01

    Over the past two quarters, our work has focused on three main areas. The first area of interest involved a reexamination of the rate laws that were formed in past quarters. A possible error was discovered for the analytical methods used in the o-cresol oxidation study and the data were corrected, yielding a new rate equation. The data for hydroxybenzaldehydes were studied again, this time as a system of parallel oxidation and thermolysis reactions. The second area in which progress was made was the study of the thermolysis of nitrophenols and dihydroxybenzenes in supercritical water. These investigations were needed to determine the effect that pyrolysis or hydrolysis had on our previous supercritical water oxidation experiments. Thirdly, we have continued to investigate the use of molecular orbital theory in the determination reactivity indices. A reactivity index, such as the enthalpy of formation, may be used in a structure-reactivity relationship to summarize the kinetics for the oxidation of phenolics in supercritical water. Progress in each of these areas is summarized.

  10. Are oxidative stress mechanisms the common denominator in the progression from hepatic steatosis towards non-alcoholic steatohepatitis (NASH)?

    PubMed

    Tariq, Zoon; Green, Charlotte J; Hodson, Leanne

    2014-08-01

    Non-alcoholic fatty liver disease (NAFLD) is not a single disease entity, rather it describes a spectrum of liver conditions that range from fatty liver (steatosis) to more severe steatosis coupled with marked inflammation and fibrosis [non-alcoholic steatohepatitis (NASH)] to severe liver disease such as cirrhosis and possibly hepatocellular carcinoma. Obesity, notably abdominal obesity, is a common risk factor for NAFLD. The pathogenesis from steatosis to NASH is poorly understood, and the 'two hit' model, as suggested nearly two decades ago, provides a feasible starting point for characterization of underlying mechanisms. This review will examine the oxidative stress factors ('triggers') which have been implicated as a 'second hit' in the development of primary NASH. It would be reasonable to assume that multiple, rather than single, pro-oxidative intracellular and extracellular triggers act in conjunction promoting oxidative stress that drives the development of NASH. It is likely that the common denominator of these pro-oxidative triggers is mitochondrial dysfunction. Understanding the contribution of each of these 'triggers' is an essential step in starting to understand and elucidate the mechanisms responsible for progression from steatosis to NASH, thus enabling the development of therapeutic targeting to prevent NASH development and progression.

  11. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Progress report

    SciTech Connect

    Doyle, F.M.

    1995-02-28

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. Work during the eighteenth quarter has focused on severe oxidation of coal by thermal and chemical treatment, and on investigating the partition of metal ions between such strongly oxidized coal samples and aqueous solutions. This partitioning behavior is being followed to obtain further information on the chemistry of the coal surfaces after different oxidation treatments, for example, whether partition occurs by an ion-exchange mechanism, or whether the surface is capable of changing the oxidation state of metallic species, with concurrent surface or bulk precipitation.

  12. Selective methane oxidation over promoted oxide catalysts. Quarterly technical progress report, September 8, 1992--November 30, 1992

    SciTech Connect

    Klier, K.; Herman, R.G.; Sun, Q.; Sarkany, J.

    1993-01-01

    Support effects on catalytic reactions, especially of highly exothermic oxidation reactions, can be very significant. Since we had shown that a MoO{sub 3}/SiO{sub 2} catalyst, especially when used in a double bed configuration with a Sr/La{sub 2}O{sub 3} catalyst, can selectively oxidize methane to formaldehyde, the role of the SiO{sub 2} support was investigated. Therefore, partial oxidation of methane by oxygen to form formaldehyde, carbon oxides, and C{sub 2} products (ethane and ethene) has been studied over silica catalyst supports (fumed Cabosil and Grace 636 silica gel) in the 630-780{degrees}C temperature range under ambient pressure. When relatively high gas hourly space velocities (GHSV) were utilized, the silica catalysts exhibit high space time yields (at low conversions) for methane partial oxidation to formaldehyde, and the C{sub 2} hydrocarbons were found to be parallel products with formaldehyde. In general, the selectivities toward CO were high while those toward CO{sub 2} were low. Based on the present results obtained by a double catalyst bed experiment, the observations of product composition dependence on the variation of GHSV (i.e. gas residence time), and differences in apparent activation energies of formation of C{sub 2}H{sub 6}, and CH{sub 2}O, a reaction mechanism is proposed for the activation of methane over the silica surface. This mechanism can explain the observed product distribution patterns (specifically the parallel formation of formaldehyde and C{sub 2} hydrocarbons).

  13. Oxidative stress indicated by elevated expression of Nrf2 and 8-OHdG promotes hepatocellular carcinoma progression.

    PubMed

    Ma-On, Chakriwong; Sanpavat, Anapat; Whongsiri, Patcharawalai; Suwannasin, Surasit; Hirankarn, Nattiya; Tangkijvanich, Pisit; Boonla, Chanchai

    2017-04-01

    Reactive oxygen species (ROS) is excessively generated in tumors creating an oxidative stress in tumor microenvironment. We investigated hepatic expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and 8-hydroxydeoxyguanosine (8-OHdG) in hepatocellular carcinoma (HCC) patients, and asked if ROS epigenetically upregulated Nrf2 and enhanced aggressiveness in HCC cells. Expression of Nrf2 (n = 100) and 8-OHdG (n = 53) was remarkably increased in HCC tissues compared with the noncancerous hepatic tissues. Elevated expression of 8-OHdG was associated with poor survival in HCC patients. H2O2, as ROS representative, provoked oxidative stress in HepG2 cells, indicated by increased protein carbonyl content and decreased total antioxidant capacity. Nrf2 expression and 8-OHdG formation were markedly increased in the H2O2-treated cells compared with the untreated control. Co-treatment with antioxidants, tocopheryl acetate (TA) and S-adenosylmethionine (SAM) effectively attenuated expression of Nrf2 and 8-OHdG in H2O2-treated cells. HepG2 cells treated with H2O2 had significantly higher migration and invasion capabilities than the untreated control cells, and this aggressiveness was significantly inhibited by TA and SAM. Bisulfite sequencing revealed that CpG dinucleotides in Nrf2 promoter were unmethylated in the H2O2-treated cells similar to the untreated control. In conclusion, robust histological evidence of increased antioxidative response and oxidative DNA damage in human HCC tissues was demonstrated. Elevated oxidative DNA lesion 8-OHdG was associated with shorter survival. Experimentally, ROS enhanced Nrf2 expression, 8-OHdG formation and tumor progression in HCC cells. These effects were inhibited by antioxidants. Therefore, oxidative stress-reducing regimens might be beneficial to diminish the ROS-induced HCC progression.

  14. Methane oxidation over dual redox catalysts. Quarterly technical progress report, January 1--March 31, 1989

    SciTech Connect

    Klier, K.; Herman, R.G.; Sojka, Z.

    1989-03-01

    Review and analysis of the literature data on electron transfer itself and electron transfer oxidation of alkyl radicals was done in order to understand the mechanism by which methyl radical can be oxidized to CH{sub 3}{sup +} and further substituted by OH{sup {minus}} to form methanol. This allowed to compare and classify the various possible reaction patterns, understand the mechanism and circumstances of operation of each of them and select those which can be involved in oxidation of methyl radical. As a result an approach that is complementary to catalytic test studies was proposed. It consists of investigation of a set of partial reactions which reproduce a whole catalytic cycle in order to prove the reaction mechanism. Synthesis of new oxide catalysts of the delafossite type, containing concentrated double redox sites, were designed. Synthesis of hydrozincite as a starting material for the preparation of doubly doped zinc oxide was performed.

  15. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report

    SciTech Connect

    Doyle, F.M.

    1995-05-31

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. Work during the nineteenth quarter has concluded studies of the surface functional groups produced on coal by severe thermal and chemical oxidation, and on investigating the partition of metal ions between such strongly oxidized coal samples and aqueous solutions. This partitioning behavior was being followed to obtain further information on the chemistry of the coal surfaces after different oxidation treatments. Adsorption isotherms for the uptake of Cd{sup 2+} on coal oxidized by different methods were obtained, and these and the Cu{sup 2+} adsorption isotherms reported in the last report have been scrutinized, and interpreted more exhaustively. The apparent discrepancies noted in the last report for the analysis of surface functional groups have been investigated further. The adsorption behavior has been related to the surface chemistry of Upper Freeport coal oxidized by different methods.

  16. Progressive Oxidation of Pyrite in Five Bituminous Coal Samples: An As XANES and 57Fe Mossbauer Spectroscopic Study

    SciTech Connect

    Kolker,A.; Huggins, F.

    2007-01-01

    Naturally occurring pyrite commonly contains minor substituted metals and metalloids (As, Se, Hg, Cu, Ni, etc.) that can be released to the environment as a result of its weathering. Arsenic, often the most abundant minor constituent in pyrite, is a sensitive monitor of progressive pyrite oxidation in coal. To test the effect of pyrite composition and environmental parameters on the rate and extent of pyrite oxidation in coal, splits of five bituminous coal samples having differing amounts of pyrite and extents of As substitution in the pyrite, were exposed to a range of simulated weathering conditions over a period of 17 months. Samples investigated include a Springfield coal from Indiana (whole coal pyritic S = 2.13 wt.%; As in pyrite = detection limit (d.l.) to 0.06 wt.%), two Pittsburgh coal samples from West Virginia (pyritic S = 1.32-1.58 wt.%; As in pyrite = d.l. to 0.34 wt.%), and two samples from the Warrior Basin, Alabama (pyritic S = 0.26-0.27 wt.%; As in pyrite = d.l. to 2.72 wt.%). Samples were collected from active mine faces, and expected differences in the concentration of As in pyrite were confirmed by electron microprobe analysis. Experimental weathering conditions in test chambers were maintained as follows: (1) dry Ar atmosphere; (2) dry O{sub 2} atmosphere; (3) room atmosphere (relative humidity {approx}20-60%); and (4) room atmosphere with samples wetted periodically with double-distilled water. Sample splits were removed after one month, nine months, and 17 months to monitor the extent of As and Fe oxidation using As X-ray absorption near-edge structure (XANES) spectroscopy and {sup 57}Fe Mossbauer spectroscopy, respectively. Arsenic XANES spectroscopy shows progressive oxidation of pyritic As to arsenate, with wetted samples showing the most rapid oxidation. {sup 57}Fe Mossbauer spectroscopy also shows a much greater proportion of Fe{sup 3+} forms (jarosite, Fe{sup 3+} sulfate, FeOOH) for samples stored under wet conditions, but much less

  17. Progressive oxidation of pyrite in five bituminous coal samples: An As XANES and 57Fe Mössbauer spectroscopic study

    USGS Publications Warehouse

    Kolker, Allan; Huggins, Frank E.

    2007-01-01

    Naturally occurring pyrite commonly contains minor substituted metals and metalloids (As, Se, Hg, Cu, Ni, etc.) that can be released to the environment as a result of its weathering. Arsenic, often the most abundant minor constituent in pyrite, is a sensitive monitor of progressive pyrite oxidation in coal. To test the effect of pyrite composition and environmental parameters on the rate and extent of pyrite oxidation in coal, splits of five bituminous coal samples having differing amounts of pyrite and extents of As substitution in the pyrite, were exposed to a range of simulated weathering conditions over a period of 17 months. Samples investigated include a Springfield coal from Indiana (whole coal pyritic S = 2.13 wt.%; As in pyrite = detection limit (d.l.) to 0.06 wt.%), two Pittsburgh coal samples from West Virginia (pyritic S = 1.32–1.58 wt.%; As in pyrite = d.l. to 0.34 wt.%), and two samples from the Warrior Basin, Alabama (pyritic S = 0.26–0.27 wt.%; As in pyrite = d.l. to 2.72 wt.%). Samples were collected from active mine faces, and expected differences in the concentration of As in pyrite were confirmed by electron microprobe analysis. Experimental weathering conditions in test chambers were maintained as follows: (1) dry Ar atmosphere; (2) dry O2 atmosphere; (3) room atmosphere (relative humidity ∼20–60%); and (4) room atmosphere with samples wetted periodically with double-distilled water. Sample splits were removed after one month, nine months, and 17 months to monitor the extent of As and Fe oxidation using As X-ray absorption near-edge structure (XANES) spectroscopy and 57Fe Mössbauer spectroscopy, respectively. Arsenic XANES spectroscopy shows progressive oxidation of pyritic As to arsenate, with wetted samples showing the most rapid oxidation. 57Fe Mössbauer spectroscopy also shows a much greater proportion of Fe3+ forms (jarosite, Fe3+ sulfate, FeOOH) for samples stored under wet conditions, but much less

  18. Renal expression of advanced oxidative protein products predicts progression of renal fibrosis in patients with IgA nephropathy.

    PubMed

    Wang, Jun; Liang, Min; Xu, Jie; Cao, Wei; Wang, Guo B; Zhou, Zhan M; Tian, Jian W; Jia, Nan; Zhang, Zhenhai; Nie, Jing; Liu, Youhua; Hou, Fan F

    2014-09-01

    Predicting the risk of disease progression in IgA nephropathy (IgAN) remains a challenge. This study was conducted to test the hypothesis that renal accumulation of advanced oxidized protein products (AOPPs) is an early predictor for renal progression in IgAN. This was a single-center prospective cohort study. One hundred IgAN patients with eGFR>80 ml/min/1.73 m(2) were enrolled. Seventy-seven patients were followed for a mean of 4.2 years, and 30 patients received repeat renal biopsy at a mean of 42 months after diagnosis. The outcomes were the progression of renal fibrosis and rapid progression of CKD (>5 ml/min/1.73 m(2)/year) during follow-up. Immunoreactivity of AOPPs was detected predominantly in tubular epithelial cells and co-localized with expression of TGF-β1 and angiotensin II. Renal staining score of AOPPs at diagnosis was associated with the level of tissue cellular inflammation. Accumulation of AOPPs, particularly in interstitial-infiltrating cells, was negatively correlated with changes of eGFR during follow-up; those with expression scores greater than the median at diagnosis had significantly higher incidences of rapid decline of eGFR compared with those with the score less than or equal to the median. For patients who received repeat renal biopsy, renal AOPP levels greater than the median at diagnosis were associated with increase in renal fibrosis index at repeat biopsy. After multivariate adjustment, renal AOPP expression was an independent predictor for progression of renal fibrosis and rapid decline of eGFR. Taken together, these results demonstrate that renal AOPPs might be a predictor, detectable at the time of diagnosis, for renal progression in patients with early stage IgAN.

  19. The role of oxidative imbalance in progression to AIDS: effect of the thiol supplier N-acetylcysteine.

    PubMed

    Malorni, W; Rivabene, R; Lucia, B M; Ferrara, R; Mazzone, A M; Cauda, R; Paganelli, R

    1998-11-20

    In this study we investigate the redox profile of HIV+ patients at different stages of disease with regard to immunological parameters, i.e., the number of circulating CD4+ and CD8+ lymphocytes. For this purpose, peripheral blood mononuclear cells (PBMCs) obtained from healthy donors, HIV+ patients in the asymptomatic phase, long-term nonProgressors (LTNPs), and AIDS patients have been considered. Cells have been exposed in vitro to the prooxidizing agent menadione, which is able to induce superoxide anion formation, and the susceptibility of the cells to the induced oxidative stress was estimated. Moreover, the possibility that the susceptibility of the cells to oxidative stress might be reduced by preexposing them to the antioxidizing agent N-acetylcysteine (NAC) has also been analyzed. The results obtained can be summarized as follows: (1) treatment with the prooxidant agent is capable of inducing massive morphological alterations in PBMCs. In particular, a significant correlation was found between the decrease in number of CD4+ lymphocytes in patients at different stages of disease and the susceptibility of their PBMCs to oxidative stress; (2) preincubation with NAC was able to preserve partially the ultrastructural characteristics of PBMCs isolated from HIV+ patients. In particular, a direct relationship was found between the efficacy of NAC protection and CD4 counts; (3) evaluation of the plasma index of peroxidation and the number of circulating CD4 lymphocytes indicates the existence of a positive correlation between "systemic" oxidative imbalance and stage of the disease; and (4) cells from LTNPs display either oxidative susceptibility or oxidative markers similar to those of healthy donor cells. Our study suggests that the redox profile of patients may be considered a predictive marker of AIDS progression and that the acute infection and the asymptomatic phase of the disease may represent a useful period in which the combined use of antiretroviral and

  20. Progress of the Application of Mesoporous Silica-Supported Heteropolyacids in Heterogeneous Catalysis and Preparation of Nanostructured Metal Oxides

    PubMed Central

    Ren, Yuanhang; Yue, Bin; Gu, Min; He, Heyong

    2010-01-01

    Mesoporous silica molecular sieves are a kind of unique catalyst support due to their large pore size and high surface area. Several methods have been developed to immobilize heteropolyacids (HPAs) inside the channels of these mesoporous silicas. The mesoporous silica-supported HPA materials have been widely used as recyclable catalysts in heterogeneous systems. They have shown high catalytic activities and shape selectivities in some reactions, compared to the parent HPAs in homogeneous systems. This review summarizes recent progress in the field of mesoporous silica-supported HPAs applied in the heterogeneous catalysis area and preparation of nanostructured metal oxides using HPAs as precursors and mesoporous silicas as hard templates.

  1. Genetic, Immune-Inflammatory, and Oxidative Stress Biomarkers as Predictors for Disability and Disease Progression in Multiple Sclerosis.

    PubMed

    Kallaur, Ana Paula; Reiche, Edna Maria Vissoci; Oliveira, Sayonara Rangel; Simão, Andrea Name Colado; Pereira, Wildea Lice de Carvalho Jennings; Alfieri, Daniela Frizon; Flauzino, Tamires; Proença, Caio de Meleck; Lozovoy, Marcell Alysson Batisti; Kaimen-Maciel, Damacio Ramón; Maes, Michael

    2017-01-01

    The aim of this study was to evaluate the TNFβ NcoI polymorphism (rs909253) and immune-inflammatory, oxidative, and nitrosative stress (IO&NS) biomarkers as predictors of disease progression in multiple sclerosis (MS). We included 212 MS patients (150 female, 62 male, mean (±standard deviation (SD)) age = 42.7 ± 13.8 years) and 249 healthy controls (177 female, 72 male, 36.8 ± 11 years). The disability was measured the Expanded Disability Status Scale (EDSS) in 2006 and 2011. We determined the TNFβ NcoI polymorphism and serum levels of interleukin (IL)-6, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, IL-4, IL-10, and IL-17, albumin, ferritin, and plasma levels of lipid hydroperoxides (CL-LOOH), carbonyl protein, advanced oxidation protein products (AOPPs), nitric oxide metabolites (NOx), and total radical-trapping antioxidant parameter (TRAP). The mean EDSS (±SD) in 2006 was 1.62 ± 2.01 and in 2011 3.16 ± 2.29, and disease duration was 7.34 ± 7.0 years. IL-10, TNF-α, IFN-γ, AOPP, and NOx levels were significantly higher and IL-4 lower in MS patients with a higher 2011 EDSS scores (≥3) as compared with those with EDSS < 3. The actual increases in EDSS from 2006 to 2011 were positively associated with TNF-α and IFN-γ. Increased IFN-γ values were associated with higher pyramidal symptoms and increased IL-6 with sensitive symptoms. Increased carbonyl protein and IL-10 but lowered albumin levels predicted cerebellar symptoms. The TNFB1/B2 genotype decreased risk towards progression of pyramidal symptoms. Treatments with IFN-β and glatiramer acetate significantly reduced TNF-α but did not affect the other IO&NS biomarkers or disease progression. Taken together, IO&NS biomarkers and NcoI TNFβ genotypes predict high disability in MS and are associated with different aspects of disease progression. New drugs to treat MS should also target oxidative stress pathways.

  2. Oxidative stress in the progression of Alzheimer disease in the frontal cortex.

    PubMed

    Ansari, Mubeen A; Scheff, Stephen W

    2010-02-01

    We investigated oxidative stress in human postmortem frontal cortexfrom individuals characterized as mild cognitive impairment (n= 8), mild/moderate Alzheimer disease (n = 4), and late-stage Alzheimer disease (n = 9). Samples from subjects with no cognitive impairment (n = 10) that were age- and postmortem interval-matched with these cases were used as controls. The short postmortem intervalbrain samples were processed for postmitochondrial supernatant, nonsynaptic mitochondria, and synaptosome fractions. Samples were analyzed for several antioxidants (glutathione, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, glucose-6-phosphate dehydrogenase, superoxide dismutase, catalase) and the oxidative marker, thiobarbituric acid reactive substances. The tissue was also analyzed for possible changes in protein damage using neurochemical markers for protein carbonyls, 3-nitrotyrosine, 4-hydroxynonenal, andacrolein. All 3 neuropil fractions (postmitochondrial supernatant, mitochondrial, and synaptosomal) demonstrated significant disease-dependent increases in oxidative markers. The highest changes were observed in the synaptosomal fraction. Both mitochondrial and synaptosomal fractions had significant declines in antioxidants (glutathione, glutathione peroxidase, glutathione-S-transferase, and superoxide dismutase). Levels of oxidative markers significantly correlated with Mini-Mental Status Examination scores. Oxidative stress was more localized to the synapses, with levels increasing in a disease-dependent fashion. These correlations implicate an involvement of oxidative stress in Alzheimer disease-related synaptic loss.

  3. Hypertension influences the exponential progression of inflammation and oxidative stress in streptozotocin-induced diabetic kidney

    PubMed Central

    Muthaian, Rupadevi; Pakirisamy, Rajaa Muthu; Parasuraman, Subramani; Raveendran, Ramasamy

    2016-01-01

    Objective: To investigate the association of hypertension coexisting with diabetes mellitus with oxidative stress and inflammation in the kidneys of streptozotocin (STZ)-induced diabetic rats. Materials and Methods: Male Wistar rats were used for the experiments. Blood glucose (BG), urea, blood pressure (BP), and heart rate (HR) were analyzed before and 48 h after STZ injection. Further, these parameters were monitored up to 3 months of diabetes induction. Subsequently, the inflammatory markers (C-reactive protein, tumor necrosis factor-alpha, and nitrate) and oxidative stress markers were estimated after 3 months of diabetes induction in the kidney homogenate. Histological analysis of renal tissue was also carried out. Results: Linear elevation of BG, urea, mean arterial pressure (MAP), and HR was observed up to 3 months of diabetes induction. In the same manner, inflammatory and oxidative stress markers were also found to be significantly increased. Notably, the histological analysis revealed the signs of nephropathy such as increased mesangial cell number, thickness of basement membrane, and renal artery. Inflammatory and oxidative stress markers positively correlated with elevated BP and BG, but the correlation was better with BP rather than BG. Conclusion: Hypertension has a strong implication in the increased oxidative stress and inflammation of diabetic kidney at the very early stage of diabetes mellitus. PMID:28163536

  4. Calcification and Oxidative Modifications Are Associated With Progressive Bioprosthetic Heart Valve Dysfunction.

    PubMed

    Lee, Suengwon; Levy, Robert J; Christian, Abigail J; Hazen, Stanley L; Frick, Nathan E; Lai, Eric K; Grau, Juan B; Bavaria, Joseph E; Ferrari, Giovanni

    2017-05-08

    Bioprosthetic heart valves (BHVs), fabricated from glutaraldehyde-pretreated bovine pericardium or porcine aortic valves, are widely used for the surgical or interventional treatment of heart valve disease. Reoperation becomes increasingly necessary over time because of BHV dysfunction. Forty-seven explanted BHV aortic valve replacements were retrieved at reoperation for clinically severe BHV dysfunction over the period 2010-2016. Clinical explant analyses of BHV leaflets for calcium (atomic absorption spectroscopy) and oxidized amino acids, per mass spectroscopy, were primary end points. Comorbidities for earlier BHV explant included diabetes mellitus and coronary artery bypass grafting. Mean calcium levels in BHV leaflets were significantly increased compared with unimplanted BHV (P<0.001); however, time to reoperation did not differ comparing calcified and noncalcified BHV. BHV dityrosine, an oxidized amino acid cross-link, was significantly increased in the explants (227.55±33.27 μmol/mol [dityrosine/tyrosine]) but was undetectable in unimplanted leaflets (P<0.001). BHV regional analyses revealed that dityrosine, ranging from 57.5 to 227.8 μmol/mol (dityrosine/tyrosine), was detectable only in the midleaflet samples, indicating the site-specific nature of dityrosine formation. 3-Chlorotyrosine, an oxidized amino acid formed by myeloperoxidase-catalyzed chlorinating oxidants, correlated with BHV calcium content in leaflet explant analyses from coronary artery bypass graft patients (r=0.62, P=0.01) but was not significantly correlated with calcification in non-coronary artery bypass graft explanted BHV. Both increased BHV leaflet calcium levels and elevated oxidized amino acids were associated with bioprosthesis dysfunction necessitating reoperation; however, BHV calcium levels were not a determinant of implant duration, indicating a potentially important role for oxidized amino acid formation in BHV dysfunction. © 2017 The Authors. Published on behalf of

  5. Oxidized high-density lipoprotein accelerates atherosclerosis progression by inducing the imbalance between treg and teff in LDLR knockout mice.

    PubMed

    Ru, Ding; Zhiqing, He; Lin, Zhu; Feng, Wu; Feng, Zhang; Jiayou, Zhang; Yusheng, Ren; Min, Fan; Chun, Liang; Zonggui, Wu

    2015-05-01

    High density lipoprotein (HDL) dysfunction has been widely reported in clinic, and oxidation of HDL (ox-HDL) was shown to be one of the most common modifications in vivo and participate in the progression of atherosclerosis. But the behind mechanisms are still elusive. In this study, we firstly analyzed and found strong relationship between serum ox-HDL levels and risk factors of coronary artery diseases in clinic, then the effects of ox-HDL in initiation and progression of atherosclerosis in LDLR knockout mice were investigated by infusion of ox-HDL dissolved in chitosan hydrogel before the formation of lesions in vivo. Several new evidence were shown: (i) the serum levels of ox-HDL peaked early before the formation of lesions in LDLR mice fed with high fat diet similar to oxidative low density lipoprotein, (ii) the formation of atherosclerotic lesions could be accelerated by infusion of ox-HDL, (iii) the pro-atherosclerotic effects of ox-HDL were accompanied by imbalanced levels of effector and regulatory T cells and relative gene expressions, which implied that imbalance of teff and treg might contribute to the pro-atherosclerosis effects of ox-HDL.

  6. Creatine supplementation prevents hyperhomocysteinemia, oxidative stress and cancer-induced cachexia progression in Walker-256 tumor-bearing rats.

    PubMed

    Deminice, Rafael; Cella, Paola Sanches; Padilha, Camila S; Borges, Fernando H; da Silva, Lilian Eslaine Costa Mendes; Campos-Ferraz, Patrícia L; Jordao, Alceu Afonso; Robinson, Jason Lorne; Bertolo, Robert F; Cecchini, Rubens; Guarnier, Flávia Alessandra

    2016-08-01

    The purpose of this study was to investigate (1) the impact of tumor growth on homocysteine (Hcy) metabolism, liver oxidative stress and cancer cachexia and, (2) the potential benefits of creatine supplementation in Walker-256 tumor-bearing rats. Three experiments were conducted. First, rats were killed on days 5 (D5), 10 (D10) and 14 (D14) after tumor implantation. In experiment 2, rats were randomly assigned to three groups designated as control (C), tumor-bearing (T) and tumor-bearing supplemented with creatine (TCr). A life span experiment was conducted as the third experiment. Creatine was supplied in drinking water for 21 days (8 g/L) in all cases. Tumor implantation consisted of a suspension of Walker-256 cells (8.0 × 10(7) cells in 0.5 mL of PBS). The progressive increase (P < 0.05) in tumor mass coincided with a progressively lower body weight and higher hepatic oxidative stress; plasma Hcy concentration was 80 % higher (P < 0.05) by 10 days of tumor implantation. Impaired Hcy metabolism was evidenced by decreased hepatic betaine-homocysteine methyltransferase (Bhmt), glycine N-methyltransferase (Gnmt) and cystathionine beta synthase (CBS) gene expression. In contrast, creatine supplementation promoted a 28 % reduction of tumor weight (P < 0.05). Plasma Hcy (C 6.1 ± 0.6, T 10.3 ± 1.5, TCr 6.3 ± 0.9, µmol/L) and hepatic oxidative stress were lower in the TCr group compared to T. Creatine supplementation was unable to decrease Hcy concentration and to increase SAM/SAH ratio in tumor tissue. These data suggest that creatine effects on hepatic impaired Hcy metabolism promoted by tumor cell inoculation are responsible to decrease plasma Hcy in tumor-bearing rats. In conclusion, Walker-256 tumor growth is associated with progressive hyperhomocysteinemia, body weight loss and liver oxidative stress in rats. Creatine supplementation, however, prevented these tumor-associated perturbations.

  7. [Oxidation catalysis with tris(pyrazolyl)borate metal complexes]. Progress report

    SciTech Connect

    Theopold, K.H.

    1993-07-01

    Progress was made in elucidating the mechanism of the O{sub 2} activation by tris(pyrazolyl)borate cobalt complexes. A series of Tp{sup i}Co-complexes (Tp{sup i}=hydridotris(3-i-propyl-5- methylpyrazolyl)borate) was prepared.

  8. A resistant starch fiber diet ameliorates oxidative stress, inflammation, and progression of chronic kidney disease (CKD)

    USDA-ARS?s Scientific Manuscript database

    Inflammation is a constant feature and a major mediator of CKD progression. It is, in part, driven by altered gut microbiome and disruption of intestinal epithelial barrier, events which are primarily caused by: 1- urea influx in the intestine resulting in dominance of urease-possessing bacteria; 2-...

  9. High amylose resistant starch diet ameliorates oxidative stress, inflammation, and progression of chronic kidney disease

    USDA-ARS?s Scientific Manuscript database

    Inflammation is a major mediator of CKD progression and is partly driven by altered gut microbiome and intestinal barrier disruption, events which are caused by: urea influx in the intestine resulting in dominance of urease-possessing bacteria; disruption of epithelial barrier by urea-derived ammoni...

  10. Progress in spin-on metal oxide hardmask materials for filling applications

    NASA Astrophysics Data System (ADS)

    Yao, Huirong; Dioses, Alberto D.; Mullen, Salem; Wolfer, Elizabeth; McKenzie, Douglas; Rahman, Dalil; Cho, JoonYeon; Padmanaban, Munirathna; Petermann, Claire; Her, YoungJun; Cao, Yi

    2015-03-01

    It is well known that metal oxide films are useful as hard mask material in semiconductor industry for their excellent etch resistance against plasma etches. In the advanced lithography processes, in addition to good etch resistance, they also need to possess good wet removability, fill capability, in high aspect ratio contacts or trenches. Conventional metal containing materials can be applied by chemical vapor deposition (CVD) or atomic layer deposition (ALD). Films derived from these techniques have difficulty in controlling wet etch, have low throughput and need special equipment. This leads to high costs. Therefore it is desirable to develop simple spin-on coating materials to generate metal oxide hard masks that have good trench or via filling performances using spin track friendly processing conditions. In this report, novel spin-on type inorganic formulations providing Ti, W, Hf and Zr oxide hard masks will be described. The new materials have demonstrated high etch selectivity, good filling performances, wet removal capability, low trace metals and good shelf-life stability. These novel AZ® Spin-on metal hard mask formulations can be used in several new applications and can potentially replace any metal, metal oxide, metal nitride or silicon-containing hard mask films currently deposited using CVD process in the semiconductor manufacturing process.

  11. Recent Progress in Two-Dimensional Oxide Photocatalysts for Water Splitting.

    PubMed

    Ida, Shintaro; Ishihara, Tatsumi

    2014-08-07

    This Perspective focuses on the photocatalytic activity of two-dimensional (2D) oxide and nitrogen-doped oxide crystals and the effective use of 2D photocatalysts for understanding the mechanism of the water splitting reaction. Strategies for improving the activities of 2D photocatalysts are slightly different from those of bulk photocatalysts. Although it is well-known that a photocatalyst without co-catalyst loading has low activity for hydrogen production from water, a certain type of 2D oxide nanosheet shows high activity without co-catalyst loading. It is difficult to determine what factors contribute to this separation of oxidation and reduction sites of water because there are many factors on the reaction surface. A nanosheet p-n junction surface is an ideal surface for understanding the carrier transfer during the photocatalytic reaction. In this system, the driving force of the carrier transfer to the reaction sites was found to be the potential gradient generated by the nanosheet junction.

  12. Cuprous oxide photovoltaic cells. Third quarterly technical progress report, October 9, 1979 to January 8, 1980

    SciTech Connect

    Trivich, D.

    1980-01-08

    Previous work in this laboratory on cuprous oxide Schottky barrier photovoltaic cells showed that some potential improvements were limited by chemical degradations at the junction (1), e.g., in Al/Cu/sub 2/O cells, the aluminum reduced the surface of the Cu/sub 2/O to metallic Cu. The present project is being devoted to a study of methods to avoid this problem and also to the development of other methods of improving the efficiency of Cu/sub 2/O cells. The first quarterly report was devoted to a study of thin oxide interlayers between the metal and the Cu/sub 2/O which gives MIS structures. The most stable interlayers were obtained with SiO/sub 2/. The second quarterly report covered some initial work on heterojunctions with other oxides on Cu/sub 2/O. The most stable heterojunctions were obtained with CdO on Cu/sub 2/O. The present report presents some results on Auger studies of the oxide heterojunctions, the preparation of doped Cu/sub 2/O by introduction of impurities in the starting copper, the exploration of several method for the study of diffusion length, and some initial attempts on the laser annealing of Cu/sub 2/O.

  13. Methane oxidation over dual redox catalysts. Quarterly technical progress report, April--June 1989

    SciTech Connect

    Klier, K.; Herman, R.G.; Sojka, Z.

    1989-06-01

    The objective of this research is to develop the scientific background for direct catalytic oxidation of methane over oxides that are doubly doped with transition metal ions. The desired process aims at employing of a double redox mechanism, where one redox couple is utilized for activation of oxygen and another for the conversion of CH{sub 3} radicals to carbocations via electron transfer reaction. The latter species can react with surface OH{sup {minus}} groups to form methanol or formaldehyde. To establish the foundations for such a process, two groups of the catalysts, one containing dispersed redox centers (Cu{sup I}/Fe{sup III}/ZnO and Cu{sup I}/Sn{sup IV}/ZnO) and a second of delafossite-type oxides containing concentrated redox centers (CuFeO{sub 2}, CuCoO{sub 2}) were synthesized and chemically analyzed for composition. For the sake of comparison, undoped ZnO treated in the same way as doped zinc oxide catalysts was also prepared. The samples were characterized by X-ray diffraction, BET surface area measurements and preliminarily by scanning electron microscopy. A catalytic testing unit and reactor to study the title reaction were designed and constructed.

  14. Recent progress in high performance and reliable n-type transition metal oxide-based thin film transistors

    NASA Astrophysics Data System (ADS)

    Kwon, Jang Yeon; Kyeong Jeong, Jae

    2015-02-01

    This review gives an overview of the recent progress in vacuum-based n-type transition metal oxide (TMO) thin film transistors (TFTs). Several excellent review papers regarding metal oxide TFTs in terms of fundamental electron structure, device process and reliability have been published. In particular, the required field-effect mobility of TMO TFTs has been increasing rapidly to meet the demands of the ultra-high-resolution, large panel size and three dimensional visual effects as a megatrend of flat panel displays, such as liquid crystal displays, organic light emitting diodes and flexible displays. In this regard, the effects of the TMO composition on the performance of the resulting oxide TFTs has been reviewed, and classified into binary, ternary and quaternary composition systems. In addition, the new strategic approaches including zinc oxynitride materials, double channel structures, and composite structures have been proposed recently, and were not covered in detail in previous review papers. Special attention is given to the advanced device architecture of TMO TFTs, such as back-channel-etch and self-aligned coplanar structure, which is a key technology because of their advantages including low cost fabrication, high driving speed and unwanted visual artifact-free high quality imaging. The integration process and related issues, such as etching, post treatment, low ohmic contact and Cu interconnection, required for realizing these advanced architectures are also discussed.

  15. Imaging of oxidation-specific epitopes with targeted nanoparticles to detect high-risk atherosclerotic lesions: Progress and future directions

    PubMed Central

    Briley-Saebo, Karen; Yeang, Calvin; Witztum, Joseph L.; Tsimikas, Sotirios

    2014-01-01

    Oxidation-specific epitopes (OSE) within developing atherosclerotic lesions are key antigens that drive innate and adaptive immune responses in atherosclerosis, leading to chronic inflammation. Oxidized phospholipids and malondialdehyde-lysine epitopes are well-characterized OSE present in human atherosclerotic lesions, particularly in pathologically defined vulnerable plaques. Using murine and human OSE-specific antibodies as targeting agents, we have developed radionuclide and magnetic resonance based nanoparticles, containing gadolinium, manganese or lipid-coated ultrasmall superparamagnetic iron oxide, to noninvasively image OSE within experimental atherosclerotic lesions. These methods quantitate plaque burden, allow detection of lesion progression and regression, plaque stabilization, and accumulation of OSE within macrophage-rich areas of the artery wall, suggesting they detect the most active lesions. Future studies will focus on using “natural” antibodies, lipopeptides and mimotopes for imaging applications. These approaches should enhance the clinical translation of this technique to image, monitor, evaluate efficacy of novel therapeutic agents and guide optimal therapy of high-risk atherosclerotic lesions. PMID:25297940

  16. Metal-Organic Framework-Derived Nanoporous Metal Oxides toward Supercapacitor Applications: Progress and Prospects.

    PubMed

    Salunkhe, Rahul R; Kaneti, Yusuf V; Yamauchi, Yusuke

    2017-06-27

    Transition metal oxides (TMOs) have attracted significant attention for energy storage applications such as supercapacitors due to their good electrical conductivity, high electrochemical response (by providing Faradaic reactions), low manufacturing costs, and easy processability. Despite exhibiting these attractive characteristics, the practical applications of TMOs for supercapacitors are still relatively limited. This is largely due to their continuous Faradaic reactions, which can lead to major changes or destruction of their structure as well phase changes (in some cases) during cycling, leading to the degradation in their capacitive performance over time. Hence, there is an immediate need to develop new synthesis methods, which will readily provide stable porous architectures, controlled phase, as well as useful control over dimensions (1-D, 2-D, and 3-D) of the metal oxides for improving their performance in supercapacitor applications. Since its discovery in late 1990s, metal-organic frameworks (MOFs) have influenced many fields of material science. In recent years, they have gained significant attention as precursors or templates for the derivation of porous metal oxide nanostructures and nanocomposites for next-generation supercapacitor applications. Even though these materials have widespread applications and have been widely studied in terms of their structural features and synthesis, it is still not clear how these materials will play an important role in the development of the supercapacitor field. In this review, we will summarize the recent developments in the field of MOF-derived porous metal oxide nanostructures and nanocomposites for supercapacitor applications. Furthermore, the current challenges along with the future trends and prospects in the application of these materials for supercapacitors will also be discussed.

  17. Aromatics oxidation and soot formation in flames. Progress report, August 15, 1990--August 14, 1993

    SciTech Connect

    Howard, J.B.; Pope, C.J.; Shandross, R.A.; Yadav, T.

    1993-04-01

    This project is concerned with the kinetics and mechanisms of aromatics oxidation and soot and fullerenes formation in flames. The scope includes detailed measurements of profiles of stable and radical species concentrations in low-pressure one-dimensional premixed flames. Intermediate species identifications and mole fractions, fluxes, and net reaction rates calculated from the measured profiles are used to test postulated reaction mechanisms. Particular objectives are to identify, and to confirm or determine rate constants for, the main benzene oxidation reactions in flames, and to characterize soot and fullerenes and their formation mechanisms and kinetics. Stable and radical species profiles in the aromatics oxidation study are measured using molecular beam sampling with on-line mass spectrometry. The rate of soot formation measured by conventional optical techniques is found to support the hypotheses that particle inception occurs through reactive coagulation of high molecular weight PAH in competition with destruction by OHattack, and that the subsequent growth of the soot mass occurs through addition reactions of PAH and C{sub 2}H{sub 2} with the soot particles. During the first year of this reporting period, fullerenes C{sub 60} and C{sub 70} in substantial quantities were found in the flames being studied. The fullerenes were recovered, purified and spectroscopically identified. The yields of C{sub 60} and C{sub 70} were then determined over ranges of conditions in low-pressure premixed flames of benzene and oxygen.

  18. Surface properties of photo-oxidized bituminous coals. Technical progress report, April 1995--June 1995

    SciTech Connect

    Mitchell, G.; Davis, A.; Chander, S.

    1995-08-01

    During this report period, analysis of the vitrinite concentrate samples of the Lower Kittanning (PSOC-1562) and Illinois No. 6 (DECS-24) seams were completed. These results show that the concentrates are in excess of 97 vol. % vitrinite and that the sample remains in good shape for microflotation and GC/MS experiments. Two new coal samples, the hvAb Banner seam (DECS-29) and the mvb Splashdam seam (DECS-30) were collected in mid-June. Preliminary processing of the channel samples suggests that the Banner seam sample is severely weathered and may need to be replaced. Collection of a third sample, the hvBb Ohio No. 4a seam, was delayed until next quarter. Surface oxidation of a powdered vitrinite concentrate sample of the Pittsburgh seam (DECS-23) was completed during this quarter. The technique of photo-oxidizing vitrain samples using our optical microscope was laborious and time consuming. Even after the procedure was streamlined the procedure of irradiating 1.4 g of vitrinite required 29 days. A limited number of samples will be irradiated in this manner in order to maintain continuity between our fluorometric measurements and microflotation experiments, but other methods of surface oxidation will be explored. Presentations were made at the DOE Contractor`s Review and Peer Review meetings held in Nashville, TN on June 13-14, 1995.

  19. Oxidative Stress and Galactose-Deficient IgA1 as Markers of Progression in IgA Nephropathy

    PubMed Central

    Camilla, Roberta; Suzuki, Hitoshi; Daprà, Valentina; Loiacono, Elisa; Peruzzi, Licia; Amore, Alessandro; Ghiggeri, Gian Marco; Mazzucco, Gianna; Scolari, Francesco; Gharavi, Ali G.; Appel, Gerald B.; Troyanov, Stéphan; Novak, Jan; Julian, Bruce A.

    2011-01-01

    Summary Background and objectives We assessed the activation of the oxidative stress pathway in patients with IgA nephropathy (IgAN), while evaluating the classic marker of the disease (galactose-deficient serum IgA1). Design, setting, participants, & measurements Sera from 292 patients and 69 healthy controls from Italy and the United States were assayed for advanced oxidation protein products (AOPPs), free sulfhydryl groups on albumin (SH-Alb), and IgA1 with galactose-deficient hinge-region O-glycans (Gd-IgA1). Gd-IgA1 was detected by binding to Helix aspersa agglutinin (HAA) and expressed as total Gd-IgA1 or as degree of galactose deficiency relative to a standard Gd-IgA1 myeloma protein (%HAA). Results Sera from IgAN patients showed higher levels of Gd-IgA1, %HAA, and AOPPs, but lower levels of SH-Alb in comparison to that from healthy controls. Serum levels of AOPPs significantly correlated with serum Gd-IgA1 and %HAA. The relationship between these biomarkers and clinical features at sampling and during follow-up was assessed in 62 patients with long-term follow-up. AOPPs and %HAA correlated with proteinuria at sampling and independently associated with subsequent proteinuria. Levels of AOPPs correlated with rate of decline in renal function after sampling. The combination of a high level of AOPPs and a high level of %HAA associated with decline in estimated GFR. Conclusions Serum levels of aberrantly glycosylated IgA1 are elevated and oxidative stress pathways are activated in patients with IgAN; the intensity of the stress correlated with expression and progression of the disease. We speculate that oxidative stress may modulate the nephrotoxicity of aberrantly glycosylated IgA1 in IgAN. PMID:21784819

  20. Ionizing radiation induced catalysis on metal oxide particles. 1998 annual progress report

    SciTech Connect

    Fryberger, T.; Chambers, S.A.; Daschbach, J.L.; Henderson, M.A.; Peden, C.H.F.; Su, Y.; Wang, Y.

    1998-06-01

    'High-level radioactive waste storage tanks within DOE sites contain significant amounts of organic components (solid and liquid phases) in the form of solvents, extractants, complexing agents, process chemicals, cleaning agents and a variety of miscellaneous compounds. These organics pose several safety and pretreatment concerns, particularly for the Hanford tank waste. Remediation technologies are needed that significantly reduce the amounts of problem organics without resulting in toxic or flammable gas emissions, and without requiring thermal treatments. These restrictions pose serious technological barriers for current organic destruction methods which utilize oxidation achieved by thermal or chemical activation. This project focuses on using ionizing radiation (a,b,g) to catalytically destroy organics over oxide materials through reduction/oxidation (redox) chemistry resulting from electron-hole (e{sup -}/h{sup +}) pair generation. Conceptually this process is an extension of visible and near-UV photocatalytic processes known to occur at the interfaces of narrow bandgap semiconductors in both solution and gas phases. In these processes, an electron is excited across the energy gap between the filled and empty states in the semiconductor. The excited electron does reductive chemistry and the hole (where the electron was excited from) does oxidative chemistry. The energy separation between the hole and the excited electron reflects the redox capability of the e{sup -}/h{sup +} pair, and is dictated by the energy of the absorbed photon and the bandgap of the material. The use of ionizing radiation overcomes optical transparency limitations associated with visible and near-UV illumination (g-rays penetrate much farther into a solution than UV/Vis light), and permits the use of wider bandgap materials (such as ZrO{sub 2}) which possess potentially greater redox capabilities than those with narrow bandgap materials. Experiments have been aimed at understanding the

  1. 2015 Progress Report/July 2016: Iron Oxide Redox Transformation Pathways: The Bulk Electrical Conduction Mechanism

    SciTech Connect

    Scherer, Michelle M.; Rosso, Kevin M.

    2016-07-25

    Despite decades of research on the reactivity and stable isotope properties of Fe oxides, the ability to describe the redox behavior of Fe oxides in the environment is still quite limited. This is due, in large part, to the analytical and spatial complexities associated with studying microscopic processes at the Fe oxide-water interface. This project had the long-term vision of filling this gap by developing a detailed understanding of the relationship between interfacial ET processes, surface structure and charge, and mineral semiconducting properties. We focused on the Fe(III)-oxides and oxyhydroxides because of their geochemical preponderance, versatility in synthesis of compositionally, structurally, and morphologically tailored phases, and because they are amenable to a wide range of surface and bulk properties characterization. In particular, reductive transformation of phases such as hematite (α-Fe2O3) and goethite (α-FeOOH) in aqueous solution can serve as excellent model systems for studies of electron conduction processes, as well as provide valuable insights into effect of nanoscale conductive materials on contaminant fate at DOE sites. More specifically, the goal of the Iowa component of this project was to use stable Fe isotope measurements to simultaneously measure isotope specific oxidation states and concentrations of Fe at the hematite-water and goethite-water interface. This work builds on our previous work where we used an innovative combination of 57Fe Mössbauer spectroscopy and high precision isotope ratio measurements (MC-ICP-MS) to probe the dynamics of the reaction of aqueous Fe(II) with goethite. Mössbauer spectroscopy detects 57Fe only among all other Fe isotopes and we have capitalized on this to spectroscopically demonstrate Fe(II)-Fe(III) electron transfer between sorbed Fe(II) and Fe(III) oxides (Handler, et al., 2009; Gorski, et al. 2010; Rosso et al., 2010). By combining the M

  2. Methane oxidation over dual redox catalysts. Quarterly technical progress report, October--December 1991

    SciTech Connect

    Klier, K.; Herman, R.G.; Di Cosimo, J.I.

    1992-02-01

    The effect of doping lanthana-based catalysts with antimony and bismuth on the catalytic behavior toward the selective oxidation of methane has been studied. New catalytic results have been obtained upon doping the Sr/La{sub 2}O{sub 3} catalyst, obtained from AMOCO Oil Co., with the acidic Sb and Fe dopants. Both activity and selectivity of the original Sr/La{sub 2}O{sub 3} catalyst can be modified by introducing small amounts of either dopant. Iron doping lowered selectivity to C{sub 2} products whereas antimony increased the selectivity while decreasing the reaction temperature by 100{degrees}C.

  3. Recent Progress in Application of Internal Oxidation Technique in Nb3Sn Strands

    SciTech Connect

    Xu, Xingchen; Peng, Xuan; Sumption, Michael; Collings, E. W.

    2016-10-13

    The internal oxidation technique can generate ZrO2 nano particles in Nb3Sn strands, which markedly refine the Nb3Sn grain size and boost the high-field critical current density (Jc). This article summarizes recent efforts on implementing this technique in practical Nb3Sn wires and adding Ti as a dopant. It is demonstrated that this technique can be readily incorporated into the present Nb3Sn conductor manufacturing technology. Powder-in-tube (PIT) strands with fine subelements (~25 µm) based on this technique were successfully fabricated, and proper heat treatments for oxygen transfer were explored. Future work for producing strands ready for applications is proposed.

  4. Ionizing radiation induced catalysis on metal oxide particles. 1997 annual progress report

    SciTech Connect

    Fryberger, T.A.

    1997-06-01

    'This project focuses on a novel approach for destroying organics found in high-level mixed waste prevalent at DOE sites. In this project the authors propose that organics can be destroyed by utilizing reduction/oxidation (redox) chemistry resulting from electron-hole (e{sup -}/h{sup +}) pairs generated in stable, wide bandgap semiconductors via interactions with ionizing radiation ({alpha}, {beta}, {gamma}). Conceptually this process is an extension of visible and near-UV photocatalytic processes known to occur at the interfaces of narrow bandgap semiconductors in both solution and gas phases. In these processes, an electron is excited across the energy gap between the filled and empty states in the semiconductor. The excited electron does reductive chemistry and the hole (the point from which the electron was excited) does oxidative chemistry. The energy separation between the hole and the excited electron reflects the redox capability of the e{sup -}/h{sup +} pair, and is dictated by the energy of the absorbed photon and the bandgap of the material. The use of ionizing radiation has advantages in that it (1) overcomes optical transparency limitations associated with visible and near-UV illumination (y-rays penetrate much farther into a solution than UV/Vis light), and (2) permits the use of wider bandgap materials (such as ZrO{sub 2}), which possess potentially greater redox capabilities than those with narrow bandgap materials. Planned experiments are aimed at extending the body of knowledge about e{sup -}/h{sup +} pair chemistry of semiconducting metal oxide (MO) materials by examining the influence of surface structure, defects, and dopants on the photocatalytic activity of narrow bandgap materials (TiO{sub 2}), and by expanding these studies to wider bandgap materials (ZrO{sub 2}) that are virtually unexplored in terms of their e{sup -}/h{sup +} pair chemistry. Experiments are being conducted in three areas: (1) g-radiocatalysis of reactant-colloidal metal

  5. Superior catalysts for selective catalytic reduction of nitric oxide. Quarterly technical progress report, October 1, 1994--December 31, 1994

    SciTech Connect

    Li, W.B.; Yang, R.T.

    1994-12-31

    During the past quarter, progress was made in three tasks. The poisoning effects of alkali metals (as Na{sub 2}O, K{sub 2}0 and Cs{sub 2}O) on iron oxide pillared clay (Fe-Bentonite) catalyst for selective catalytic reduction (SCR) of NO with NH{sub 3} were investigated. The effects of sulfur dioxide and water vapor on the performance of the high activity catalyst, that is, Ce-doped Fe-Bentonite pillared clay (Ce-Fe-Bentonite) were examined. In addition, an iron ion-exchanged titania pillared clay (Ti-PILC) was prepared and its catalytic activity for the SCR of NO with NH{sub 3} was studied, which showed a high activity and a high S0{sub 2} and H{sub 2}0 resistance at high temperatures (i.e., above 400{degree}C).

  6. Actinomycetes mediated biogenic synthesis of metal and metal oxide nanoparticles: Progress and challenges.

    PubMed

    Manimaran, Manickavelu; Kannabiran, Krishnan

    2017-03-07

    Actinomycetes mediated biogenic synthesis of metal nanoparticles and their antimicrobial activities are well documented. Actinomycetes facilitate both intracellular and extracellular metal nanoparticles synthesis and are efficient candidates for the production of polydispersed, stable and ultra-small size metal nanoparticles. Secondary metabolites and new chemical entities derived from actinomycetes have not been extensively studied for the synthesis of metal/ metal oxide nanoparticles. The present review focuses on biogenic synthesis of metal nanoparticles from actinomycetes and the scope for exploring actinomycetes derived compounds (enzymes, organics acids and bioactive compounds) as metal and metal oxide reducing agents for the synthesis of desired nanoparticles. This review also focuses on challenges faced in the applications nanoparticles and the methods to synthesise biogenic metal nanoparticles with desired physiochemical properties such as ultra-small size, large surface to mass ratio, high reactivity etc. Methods to evade their toxicity and unique interactions with biological systems to improve their chance as an alternative therapeutic agent in medical and pharmaceutical industry are also discussed. This article is protected by copyright. All rights reserved.

  7. Oxidation of phenolics in supercritical water. Quarterly technical progress report, September 1, 1993--November 30, 1993

    SciTech Connect

    Savage, P.E.

    1993-12-31

    Oxidation reactions are accomplished in an isothermal, high-pressure, flow reactor designed specifically for operation at supercritical water conditions. The reactor feed stream is prepared by mixing two separate streams. One stream is an aqueous solution of the phenolic reactant and the second stream is water with dissolved oxygen. Controlling the flow rates of these two streams allows us to control the reactor residence time and the relative amounts of the phenol and oxygen fed to the reactor. The reactor effluent is cooled and depressorized and then collected for analysis. The gaseous products are analyzed by gas chromatography (GC). The liquid-phase products are analyzed by GC, high-performance liquid chromatography, and GC-mass spectrometry. Our work to date has focused on the oxidation of cresols in SCW. We have explored the effects of temperature, pressure, and the concentrations of o-cresol, oxygen, and water. Table I gives these experimental conditions and the resulting ocresol conversions. We reported a portion of this data in our previous quarterly report. New information is given in the last three columns where we report the molar yields of phenol, CO{sub 2}, and CO. Molar yields were calculated as the molar flow rate of a given product divided by the initial molar flow rate of o-cresol and normalized by the stoichiometric coefficient. Earlier, we used the o-cresol conversion data to determine the parameters in a global reaction rate law for o-cresol disappearance.

  8. Factors affecting mutational specificity induced by ionizing radiation and oxidizing radicals. Progress report

    SciTech Connect

    Strauss, B.

    1992-07-01

    We propose to analyze the factors affecting the specificity of mutational change as induced by ionizing radiation and oxidizing radicals. We want to understand not only the rules the affect base substitution but also the mechanisms(s) by which additions and deletions are produced, since deletions are a common consequence of radiation. We wish to carry out this analysis in an in vitro mutation system that permits us to analyze the role of base sequence, of polymerase and of mutagenic agent. Our system is designed to screen out most direct breaks as a cause of mutation and should indicate the changes resulting from base damage to the DNA. Questions addressed include: 1. What types of base substitution mutations are induced by ionizing radiation and oxidizing radicals? 2. Are deletions and/or additions produced? 3. Is there a difference in type of mutation produced dependent on the polymerase used? Do mammalian polymerase plus their accessory factors result in different patterns of mutation. 4. What is the mechanism by which base damage is converted to mutation. Our proposal was based on utilization of an in vitro system in which mutations generated by the in vitro copying of a reporter gene sequence could be readily scored.

  9. Association of FMO3 Variants and Trimethylamine N-Oxide Concentration, Disease Progression, and Mortality in CKD Patients

    PubMed Central

    Robinson-Cohen, Cassianne; Newitt, Richard; Shen, Danny D.; Rettie, Allan E.; Kestenbaum, Bryan R.; Himmelfarb, Jonathan; Yeung, Catherine K.

    2016-01-01

    Elevated levels of circulating pro-atherogenic uremic solutes, particularly trimethylamine N-oxide (TMAO), have been implicated in cardiovascular disease development in patients with chronic kidney disease (CKD). TMAO is generated from trimethylamine (TMA) via metabolism by hepatic flavin-containing monooxygenase isoform 3 (FMO3). We determined the functional effects of three common FMO3 variants at amino acids 158, 308, and 257 on TMAO concentrations in a prospective cohort study and evaluated associations of polymorphisms with CKD progression and mortality. Each additional minor allele at amino acid 158 was associated with a 0.38 μg/mL higher circulating TMAO (p = 0.01) and with faster rates of annualized relative eGFR decline. Participants with 0, 1 and 2 variant alleles averaged an eGFR loss of 8%, 12%, and 14% per year, respectively (p-for trend = 0.05). Compared to participants with the homozygous reference allele, heterozygous and homozygous variant participants had a 2.0-fold (95% CI: 0.85, 4.6) and 2.2-fold (95% CI: 0.89, 5.48) higher risk of mortality, respectively (p-for-trend = 0.04). No associations with clinical outcomes were observed for allelic variants at amino acids 257 or 308. Understanding the contribution of genetic variation of FMO3 to disease progression and all-cause mortality can guide recommendations for diet modification or pharmacotherapy in CKD patients at increased risk of adverse outcomes. PMID:27513517

  10. LDRD Progress Report: Radioimmunotherapy using oxide nanoparticles: Radionuclide contaiment and mitigation of normal tissue toxicity.

    SciTech Connect

    Rondinone, Adam Justin; Dai, Sheng; Mirzadeh, Saed; Kennel, Steve J

    2005-10-01

    Radionuclides with specific emission properties can be incorporated into metal-chalcogenide and metal-oxide nanoparticles. Coupled to antibodies, these conjugates could be injected into the bloodstream to target and destroy non-solid tumors or target organs for radioimaging. In the first year of this project, two types of radioactive nanoparticles, CdTe: {sup 125m}Te and Y{sub 2}O{sub 3}: {sup 170}Tm were synthesized and coupled to antibodies specific to murine epithelial lung tissue. The nanoparticles successfully target the lung tissue in vivo. Some leaching of the radioisotope was observed. The coming year will explore other types of nanoparticles (other crystal chemistries) in order to minimize leaching.

  11. Recent progress on magnetic iron oxide nanoparticles: synthesis, surface functional strategies and biomedical applications

    PubMed Central

    Wu, Wei; Wu, Zhaohui; Yu, Taekyung; Jiang, Changzhong; Kim, Woo-Sik

    2015-01-01

    This review focuses on the recent development and various strategies in the preparation, microstructure, and magnetic properties of bare and surface functionalized iron oxide nanoparticles (IONPs); their corresponding biological application was also discussed. In order to implement the practical in vivo or in vitro applications, the IONPs must have combined properties of high magnetic saturation, stability, biocompatibility, and interactive functions at the surface. Moreover, the surface of IONPs could be modified by organic materials or inorganic materials, such as polymers, biomolecules, silica, metals, etc. The new functionalized strategies, problems and major challenges, along with the current directions for the synthesis, surface functionalization and bioapplication of IONPs, are considered. Finally, some future trends and the prospects in these research areas are also discussed. PMID:27877761

  12. Recent progress on magnetic iron oxide nanoparticles: synthesis, surface functional strategies and biomedical applications

    NASA Astrophysics Data System (ADS)

    Wu, Wei; Wu, Zhaohui; Yu, Taekyung; Jiang, Changzhong; Kim, Woo-Sik

    2015-04-01

    This review focuses on the recent development and various strategies in the preparation, microstructure, and magnetic properties of bare and surface functionalized iron oxide nanoparticles (IONPs); their corresponding biological application was also discussed. In order to implement the practical in vivo or in vitro applications, the IONPs must have combined properties of high magnetic saturation, stability, biocompatibility, and interactive functions at the surface. Moreover, the surface of IONPs could be modified by organic materials or inorganic materials, such as polymers, biomolecules, silica, metals, etc. The new functionalized strategies, problems and major challenges, along with the current directions for the synthesis, surface functionalization and bioapplication of IONPs, are considered. Finally, some future trends and the prospects in these research areas are also discussed.

  13. Progress in bioleaching: fundamentals and mechanisms of bacterial metal sulfide oxidation--part A.

    PubMed

    Vera, Mario; Schippers, Axel; Sand, Wolfgang

    2013-09-01

    Bioleaching of metal sulfides is performed by a diverse group of microorganisms. The dissolution chemistry of metal sulfides follows two pathways, which are determined by the mineralogy and the acid solubility of the metal sulfides: the thiosulfate and the polysulfide pathways. Bacterial cells can effect this metal sulfide dissolution via iron(II) ion and sulfur compound oxidation. Thereby, iron(III) ions and protons, the metal sulfide-attacking agents, are available. Cells can be active either in planktonic state or in forming biofilms on the mineral surface; however, the latter is much more efficient in terms of bioleaching kinetics. In the case of Acidithiobacillus ferrooxidans, bacterial exopolymers contain iron(III) ions, each complexed by two uronic acid residues. The resulting positive charge allows an electrostatic attachment to the negatively charged pyrite. Thus, the first function of complexed iron(III) ions is the mediation of cell attachment, while their second function is oxidative dissolution of the metal sulfide, similar to the role of free iron(III) ions in non-contact leaching. In both cases, the electrons extracted from the metal sulfide reduce molecular oxygen via a redox chain forming a supercomplex spanning the periplasmic space and connecting both outer and inner membranes. In this review, we summarize some recent discoveries relevant to leaching bacteria which contribute to a better understanding of these fascinating microorganisms. These include surface science, biochemistry of iron and sulfur metabolism, anaerobic metabolism, and biofilm formation. The study of microbial interactions among multispecies leaching consortia, including cell-to-cell communication mechanisms, must be considered in order to reveal more insights into the biology of bioleaching microorganisms and their potential biotechnological use.

  14. d-Propranolol protects against oxidative stress and progressive cardiac dysfunction in iron overloaded rats

    PubMed Central

    Kramer, Jay H.; Spurney, Christopher F.; Iantorno, Micaela; Tziros, Constantine; Chmielinska, Joanna J.; Mak, I. Tong; Weglicki, William B.

    2013-01-01

    d-Propranolol (d-Pro: 2–8 mg·(kg body mass)−1·day−1) protected against cardiac dysfunction and oxidative stress during 3–5 weeks of iron overload (2 mg Fe–dextran·(g body mass)−1·week−1) in Sprague–Dawley rats. At 3 weeks, hearts were perfused in working mode to obtain baseline function; red blood cell glutathione, plasma 8-isoprostane, neutrophil basal superoxide production, lysosomal-derived plasma N-acetyl-β-galactosaminidase (NAGA) activity, ventricular iron content, and cardiac iron deposition were assessed. Hearts from the Fe-treated group of rats exhibited lower cardiac work (26%) and output (CO, 24%); end-diastolic pressure rose 1.8-fold. Further, glutathione levels increased 2-fold, isoprostane levels increased 2.5-fold, neutrophil superoxide increased 3-fold, NAGA increased 4-fold, ventricular Fe increased 4.9-fold; and substantial atrial and ventricular Fe-deposition occurred. d-Pro (8 mg) restored heart function to the control levels, protected against oxidative stress, and decreased cardiac Fe levels. After 5 weeks of Fe treatment, echocardiography revealed that the following were depressed: percent fractional shortening (%FS, 31% lower); left ventricular (LV) ejection fraction (LVEF, 17%), CO (25%); and aortic pressure maximum (Pmax, 24%). Mitral valve E/A declined by 18%, indicating diastolic dysfunction. Cardiac CD11b+ infiltrates were elevated. Low d-Pro (2 mg) provided modest protection, whereas 4–8 mg greatly improved LVEF (54%–75%), %FS (51%–81%), CO (43%–78%), Pmax (56%–100%), and E/A >100%; 8 mg decreased cardiac inflammation. Since d-Pro is an antioxidant and reduces cardiac Fe uptake as well as inflammation, these properties may preserve cardiac function during Fe overload. PMID:22913465

  15. Surface properties of photo-oxidized bituminous coals. Technical progress report, July--September 1995

    SciTech Connect

    Mitchell, G.; Polat, H.; Davis, A.; Chander, S.

    1995-11-01

    During this report period, a new whole-seam channel sample (Ohio {number_sign}4a) was collected and analyzed, together with the Upper Banner and Splash Dam samples obtained last quarter. These additions bring to seven the number of coals obtained for this project and that range in rank from hvCb to mvb. Polished blocks of each coal containing 3-4 mm wide vitrain bands were prepared for contact angle measurements of fresh and photo-oxidized surfaces. An advancing-drop technique was used to measure contact angle. In this test a droplet of distilled water is grown initially on fresh surfaces and then moved across those irradiated in blue-light for 1, 5, and 10 minutes. The sequence of growth was recorded on video tape, and the change in contact angle measured relative to position at the air/water/surface interface. Contact angles were measured on five of the coals collected for this study, namely the Illinois {number_sign}6, Ohio {number_sign}4a, Lower Kittanning (PSOC-1563), Pittsburgh and Splash Dam seams. Preliminary results show that both coal rank and irradiation time influence surface wettability as measured by contact angle. With one exception, contact angle values decreased and remained low when the droplet advanced into an irradiated area. In most cases, one minute of irradiation resulted in only a slight decrease in contact angle, whereas after 5 and 10 minutes a more significant decrease was observed. The magnitude of change in contact angle values with degree of photo-oxidation decreased as rank increased, such that lower rank bituminous coals show the greatest change and medium volatile coal the least.

  16. Effects of endothelial nitric oxide synthase gene on end stage renal disease progression in autosomal dominant polycystic kidney disease.

    PubMed

    Xue, Cheng; Zhou, Chen-Chen; Sun, Li-Jun; He, Liang-Liang; Xu, Cheng-Gang; Dai, Bing; Mei, Chang-Lin

    2014-10-01

    To investigate whether endothelial nitric oxide synthase (eNOS) gene associate with the progression of autosomal dominant polycystic kidney disease (ADPKD). Databases of EMBASE, Pubmed, ISI, Ovid Database, Cochrane library and China National Knowledge Infrastructure were all searched. Associated studies about eNOS polymorphisms and ADPKD were analyzed by meta-analysis. A total of 11 studies with Glu298Asp and 4b/a polymorphisms were included. A allele of the 4b/a polymorphism increased the risk of end stage renal disease (ESRD) in ADPKD (odds ratio (OR) = 1.85, 95% confidence interval (CI) 1.17-2.94, P = 0.009). However, GG phenotype of Glu298Asp polymorphism neither decreased the ESRD risk (OR = 0.77, 95% CI 0.55-1.08, P = 0.13) nor affected the hypertension risk (OR = 1.04, 95% CI 0.66-1.66, P = 0.86). The GG phenotype carriers had later ESRD age compared with the T allele of Glu298Asp polymorphism (WMD = 2.39; 95% CI 1.32-3.46; P < 0.0001). Significant association was also found in Caucasians (WMD = 2.41; 95% CI 1.18-3.64; P = 0.0001). Subgroup analysis by gender indicated GG genotype carriers had older age of ESRD than T allele carriers in males (WMD = 4.51; 95% CI 3.95-5.08; P = 0.00001), but not in females. GG genotype of the Glu298Asp variant slowed the ESRD progression in ADPKD, while a allele carriers of the 4b/a variant increased the risk of ESRD. Variants of eNOS gene might play different roles in the ESRD progression in ADPKD. © 2014 Asian Pacific Society of Nephrology.

  17. The Nutraceutic Silybin Counteracts Excess Lipid Accumulation and Ongoing Oxidative Stress in an In Vitro Model of Non-Alcoholic Fatty Liver Disease Progression

    PubMed Central

    Vecchione, Giulia; Grasselli, Elena; Cioffi, Federica; Baldini, Francesca; Oliveira, Paulo J.; Sardão, Vilma A.; Cortese, Katia; Lanni, Antonia; Voci, Adriana; Portincasa, Piero; Vergani, Laura

    2017-01-01

    Non-alcoholic fatty liver disease (NAFLD) is a major cause of liver-related morbidity and mortality. Oxidative stress and release of pro-inflammatory cytokines, such as tumor necrosis factor α (TNFα), are major consequences of hepatic lipid overload, which can contribute to progression of NAFLD to non-alcoholic steatohepatitis (NASH). Also, mitochondria are involved in the NAFLD pathogenesis for their role in hepatic lipid metabolism. Definitive treatments for NAFLD/NASH are lacking so far. Silybin, the extract of the milk thistle seeds, has previously shown beneficial effects in NAFLD. Sequential exposure of hepatocytes to high concentrations of fatty acids (FAs) and TNFα resulted in fat overload and oxidative stress, which mimic in vitro the progression of NAFLD from simple steatosis (SS) to steatohepatitis (SH). The exposure to 50 µM silybin for 24 h reduced fat accumulation in the model of NAFLD progression. The in vitro progression of NAFLD from SS to SH resulted in reduced hepatocyte viability, increased apoptosis and oxidative stress, reduction in lipid droplet size, and up-regulation of IκB kinase β-interacting protein and adipose triglyceride lipase expressions. The direct action of silybin on SS or SH cells and the underlying mechanisms were assessed. Beneficial action of silybin was sustained by changes in expression/activity of peroxisome proliferator-activated receptors and enzymes for FA oxidation. Moreover, silybin counteracted the FA-induced mitochondrial damage by acting on complementary pathways: (i) increased the mitochondrial size and improved the mitochondrial cristae organization; (ii) stimulated mitochondrial FA oxidation; (iii) reduced basal and maximal respiration and ATP production in SH cells; (iv) stimulated ATP production in SS cells; and (v) rescued the FA-induced apoptotic signals and oxidative stress in SH cells. We provide new insights about the direct protective effects of the nutraceutic silybin on hepatocytes mimicking

  18. Cavitational hydrothermal oxidation: A new remediation process. Annual progress report, September 1996--August 1997

    SciTech Connect

    Suslick, K.S.

    1997-11-21

    'During the past year, the authors have continued to make substantial scientific progress on the understanding of cavitation phenomena in aqueous media and applications of cavitation to remediation processes. The efforts have focused on three separate areas: sonoluminescence as a probe of conditions created during cavitational collapse in aqueous media, the use of cavitation for remediation of contaminated water, and an addition of the use of ultrasound in the synthesis of novel heterogeneous catalysts for hydrodehalogenation of halocarbons under mild conditions. In order to gain further understanding of the conditions present during cavitation, the author has continued his studies of sonoluminescence. He has made recent breakthroughs in the use of emission spectroscopy for temperature and pressure measurement of cavitation events, which he expects to publish shortly. He has been able to measure for the first time the temperature of cavitation in water during multi-bubble cavitation in the presence of aromatic hydrocarbons. The emission from excited states of C{sub 2} in water gives temperatures that are consistent with adiabatic compressional heating, with maximum temperatures of 4,300 K. Prior measurements of cavitation temperatures in low vapor pressure nonaqueous media gave somewhat higher temperatures of 5,000 K. This work lays permanently to rest exotic mechanisms for cavitational chemistry, at least for cavitation fields.'

  19. Progress in bismuth vanadate photoanodes for use in solar water oxidation.

    PubMed

    Park, Yiseul; McDonald, Kenneth J; Choi, Kyoung-Shin

    2013-03-21

    Harvesting energy directly from sunlight as nature accomplishes through photosynthesis is a very attractive and desirable way to solve the energy challenge. Many efforts have been made to find appropriate materials and systems that can utilize solar energy to produce chemical fuels. One of the most viable options is the construction of a photoelectrochemical cell that can reduce water to H(2) or CO(2) to carbon-based molecules. Bismuth vanadate (BiVO(4)) has recently emerged as a promising material for use as a photoanode that oxidizes water to O(2) in these cells. Significant advancement in the understanding and construction of efficient BiVO(4)-based photoanode systems has been made within a short period of time owing to various newly developed ideas and approaches. In this review, the crystal and electronic structures that are closely related to the photoelectrochemical properties of BiVO(4) are described first, and the photoelectrochemical properties and limitations of BiVO(4) are examined. Subsequently, the latest efforts toward addressing these limitations in order to improve the performances of BiVO(4)-based photoanodes are discussed. These efforts include morphology control, formation of composite structures, composition tuning, and coupling oxygen evolution catalysts. The discussions and insights provided in this review reflect the most recent approaches and directions for general photoelectrode developments and they will be directly applicable for the understanding and improvement of other photoelectrode systems.

  20. Direct catalytic decomposition of nitric oxide. Quarterly technical progress report No. 10, January--March 1994

    SciTech Connect

    Flytzani-Stephanopoulos, M.; Sarofim, A.F.; Zhang, Y.; Sun, T.

    1994-06-01

    This project investigates a suitable catalyst system for the direct nitric oxide decomposition in post-combustion gas streams. This process does not use a reductant, such as the ammonia used in the Selective Catalytic Reduction (SCR) of NO{sub x} to nitrogen. Therefore, it is a greatly simplified process basically involving passing the flue gas through a catalytic converter. Catalysts are prepared by incorporating metal cations into zeolite supports according to ion exchange procedures widely used in preparation of metal/zeolite catalysts. Particular emphasis is given in this work on promoted Cu-exchanged zeolites, especially the catalyst systems Mg/Cu-ZSM-5 and Ce/Cu-ZSM-5, which are promising for NO conversion to nitrogen at typical flue gas O{sub 2} and NO levels and over the temperature range of 673--873{degrees}C. The effect of zeolite modification, copper exchange level and catalyst preparation conditions on the catalytic activity are studied in O{sub 2}-free, O{sub 2}-rich gases, as well as wet (2--20% H{sub 2}O) gas streams in a packed-bed microreactor. Characterization of catalysts is performed by XRD, STEM, TEM and ESR. During this quarter it was found that severe steaming (20% H{sub 2}O) of Na-ZSM-5 at temperatures above 600{degrees}C caused partial vitreous glass formation and dealumination. Unpromoted Cu-ZSM-5 catalysts suffer drastic loss of NO decomposition activity in wet gas streams at 500{degrees}C. Activity is partially recovered in dry gas. Copper migration out of the zeolite channels leading to CuO formation has been identified by STEM/EDX. In Ce/Cu-ZSM-5 catalysts the wet gas activity i`s greatly improved. CuO particle formation is less extensive and the dry gas activity is largely recovered upon removal of the water vapor.

  1. Progressive handgrip exercise: evidence of nitric oxide-dependent vasodilation and blood flow regulation in humans

    PubMed Central

    Witman, Melissa A. H.; Ives, Stephen J.; McDaniel, John; Fjeldstad, Anette S.; Trinity, Joel D.; Conklin, Jamie D.; Supiano, Mark A.; Richardson, Russell S.

    2011-01-01

    In the peripheral circulation, nitric oxide (NO) is released in response to shear stress across vascular endothelial cells. We sought to assess the degree to which NO contributes to exercise-induced vasodilation in the brachial artery (BA) and to determine the potential of this approach to noninvasively evaluate NO bioavailability. In eight young (25 ± 1 yr) healthy volunteers, we used ultrasound Doppler to examine BA vasodilation in response to handgrip exercise (4, 8, 12, 16, 20, and 24 kg) with and without endothelial NO synthase blockade [intra-arterial NG-monomethyl-l-arginine (l-NMMA), 0.48 mg·dl−1·min−1]. Higher exercise intensities evoked significant BA vasodilation (4–12%) that was positively correlated with the hyperemic stimulus (r = 0.98 ± 0.003, slope = 0.005 ± 0.001). During NO blockade, BA vasodilation at the highest exercise intensity was reduced by ∼70% despite similar exercise-induced increases in shear rate (control, +224 ± 30 s−1; l-NMMA, +259 ± 46 s−1). The relationship and slope of BA vasodilation with increasing shear rate was likewise reduced (r = 0.48 ± 0.1, slope = 0.0007 ± 0.0005). We conclude that endothelial NO synthase inhibition with l-NMMA abolishes the relationship between shear stress and BA vasodilation during handgrip exercise, providing clear evidence of NO-dependent vasodilation in this experimental model. These results support this paradigm as a novel and valid approach for a noninvasive assessment of NO-dependent vasodilation in humans. PMID:21217074

  2. Alteration of stomach microbiota compositions in the progression of gastritis induces nitric oxide in gastric cell

    PubMed Central

    Dong, Tianyi; Feng, Qiang; Liu, Fengyan; Chang, Lap Kam; Zhou, Xiangyu; Han, Mingyong; Tian, Xingsong; Zhong, Ning; Liu, Shili

    2017-01-01

    Atrophic gastritis is considered to be an antecedent to intestinal metaplasia and gastric cancer. A previous study identified that Helicobacter pylori was absent at the severe atrophic gastritis stage, and alterations in the gastric microbial composition resembled those in gastric cancer. To explore the role of the bacteria absence of H. pylori in gastric carcinogenesis, in the current study, we compared the microbiota of clinically collected H. pylori-free gastric fluids from 30 patients with non-atrophic gastritis (N) and 22 patients with severe atrophic gastritis (S). We estimated the bacterial loads in the N and S groups by colony counting in culture agar as well as by measuring the concentration of the extracted DNA. The results showed a significant increase in bacterial load in patients with atrophic gastritis in comparison to non-atrophic gastritis. Then, we analyzed the microbial communities of the gastric fluids from all 52 patients using high-throughput sequencing of 16S rRNA amplicons. The Chao 1, Shannon and Simpson diversity indexes demonstrated that the bacterial richness and diversity were not significantly different between the N and S groups. Moreover, principal component analysis illustrated that the microbiomes from the S group were more scattered. Microbiota composition analysis showed that the entire dataset was clustered into 27 phyla, 61 classes, 106 orders, 177 families, 292 genera and 121 species. At the genus level, only the abundance of Prevotella was significantly different between the N and S groups. Further analysis showed that all the higher taxonomic categories were significantly different between the N and S groups. To assess the effects of the metabolic products of Prevotella spp. on gastric cell physiology, we treated the human gastric epithelial cell line AGS with acetic acid and monitored nitric oxide (NO) production. The results showed that acetic acid at low concentrations (0.5 and 5 µM) significantly inhibited AGS cells to

  3. Alteration of stomach microbiota compositions in the progression of gastritis induces nitric oxide in gastric cell.

    PubMed

    Dong, Tianyi; Feng, Qiang; Liu, Fengyan; Chang, Lap Kam; Zhou, Xiangyu; Han, Mingyong; Tian, Xingsong; Zhong, Ning; Liu, Shili

    2017-06-01

    Atrophic gastritis is considered to be an antecedent to intestinal metaplasia and gastric cancer. A previous study identified that Helicobacter pylori was absent at the severe atrophic gastritis stage, and alterations in the gastric microbial composition resembled those in gastric cancer. To explore the role of the bacteria absence of H. pylori in gastric carcinogenesis, in the current study, we compared the microbiota of clinically collected H. pylori-free gastric fluids from 30 patients with non-atrophic gastritis (N) and 22 patients with severe atrophic gastritis (S). We estimated the bacterial loads in the N and S groups by colony counting in culture agar as well as by measuring the concentration of the extracted DNA. The results showed a significant increase in bacterial load in patients with atrophic gastritis in comparison to non-atrophic gastritis. Then, we analyzed the microbial communities of the gastric fluids from all 52 patients using high-throughput sequencing of 16S rRNA amplicons. The Chao 1, Shannon and Simpson diversity indexes demonstrated that the bacterial richness and diversity were not significantly different between the N and S groups. Moreover, principal component analysis illustrated that the microbiomes from the S group were more scattered. Microbiota composition analysis showed that the entire dataset was clustered into 27 phyla, 61 classes, 106 orders, 177 families, 292 genera and 121 species. At the genus level, only the abundance of Prevotella was significantly different between the N and S groups. Further analysis showed that all the higher taxonomic categories were significantly different between the N and S groups. To assess the effects of the metabolic products of Prevotella spp. on gastric cell physiology, we treated the human gastric epithelial cell line AGS with acetic acid and monitored nitric oxide (NO) production. The results showed that acetic acid at low concentrations (0.5 and 5 µM) significantly inhibited AGS cells to

  4. Photocatalytic and chemical oxidation of organic compounds in supercritical carbon dioxide. Progress report for FY97

    SciTech Connect

    Blake, D.M.; Bryant, D.L.; Reinsch, V.

    1997-09-30

    and using makeup scCO{sub 2}. A chemical polishing operation can reduce the release of CO{sub 2} from the process. It can also reduce the consumption of reagents that may be used in the process to enhance extraction and cleaning. A polishing operation will also reduce or avoid formation of an additional waste stream. Photocatalytic and other photochemical oxidation chemistry have not been investigated in scCO{sub 2}. The large base of information for these reactions in water, organic solvents, or air suggest that the chemistry will work in carbon dioxide. There are compelling reasons to believe that the properties of scCO{sub 2} should increase the performance of photocatalytic chemistry over that found in more conventional fluid phases.'

  5. Zinc oxide nanorod based photonic devices: recent progress in growth, light emitting diodes and lasers.

    PubMed

    Willander, M; Nur, O; Zhao, Q X; Yang, L L; Lorenz, M; Cao, B Q; Zúñiga Pérez, J; Czekalla, C; Zimmermann, G; Grundmann, M; Bakin, A; Behrends, A; Al-Suleiman, M; El-Shaer, A; Che Mofor, A; Postels, B; Waag, A; Boukos, N; Travlos, A; Kwack, H S; Guinard, J; Le Si Dang, D

    2009-08-19

    Zinc oxide (ZnO), with its excellent luminescent properties and the ease of growth of its nanostructures, holds promise for the development of photonic devices. The recent advances in growth of ZnO nanorods are discussed. Results from both low temperature and high temperature growth approaches are presented. The techniques which are presented include metal-organic chemical vapour deposition (MOCVD), vapour phase epitaxy (VPE), pulse laser deposition (PLD), vapour-liquid-solid (VLS), aqueous chemical growth (ACG) and finally the electrodeposition technique as an example of a selective growth approach. Results from structural as well as optical properties of a variety of ZnO nanorods are shown and analysed using different techniques, including high resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM), photoluminescence (PL) and cathodoluminescence (CL), for both room temperature and for low temperature performance. These results indicate that the grown ZnO nanorods possess reproducible and interesting optical properties. Results on obtaining p-type doping in ZnO micro- and nanorods are also demonstrated using PLD. Three independent indications were found for p-type conducting, phosphorus-doped ZnO nanorods: first, acceptor-related CL peaks, second, opposite transfer characteristics of back-gate field effect transistors using undoped and phosphorus doped wire channels, and finally, rectifying I-V characteristics of ZnO:P nanowire/ZnO:Ga p-n junctions. Then light emitting diodes (LEDs) based on n-ZnO nanorods combined with different technologies (hybrid technologies) are suggested and the recent electrical, as well as electro-optical, characteristics of these LEDs are shown and discussed. The hybrid LEDs reviewed and discussed here are mainly presented for two groups: those based on n-ZnO nanorods and p-type crystalline substrates, and those based on n-ZnO nanorods and p-type amorphous substrates. Promising electroluminescence

  6. Aluminum oxide nanoparticles alter cell cycle progression through CCND1 and EGR1 gene expression in human mesenchymal stem cells.

    PubMed

    Periasamy, Vaiyapuri Subbarayan; Athinarayanan, Jegan; Alshatwi, Ali A

    2016-05-01

    Aluminum oxide nanoparticles (Al2 O3 -NPs) are important ceramic materials that have been used in a variety of commercial and industrial applications. However, the impact of acute and chronic exposure to Al2 O3 -NPs on the environment and on human health has not been well studied. In this investigation, we evaluated the cytotoxic effects of Al2 O3 -NPs on human mesenchymal stem cells (hMSCs) by using a cell viability assay and observing cellular morphological changes, analyzing cell cycle progression, and monitoring the expression of cell cycle response genes (PCNA, EGR1, E2F1, CCND1, CCNC, CCNG1, and CYCD3). The Al2 O3 -NPs reduced hMSC viability in a dose- and time-dependent manner. Nuclear condensation and fragmentation, chromosomal DNA fragmentation, and cytoplasmic vacuolization were observed in Al2 O3 -NP-exposed cells. The nuclear morphological changes indicated that Al2 O3 -NPs alter cell cycle progression and gene expression. The cell cycle distribution revealed that Al2 O3 -NPs cause cell cycle arrest in the sub-G0-G1 phase, and this is associated with a reduction in the cell population in the G2/M and G0/G1 phases. Moreover, Al2 O3 -NPs induced the upregulation of cell cycle response genes, including EGR1, E2F1, and CCND1. Our results suggested that exposure to Al2 O3 -NPs could cause acute cytotoxic effects in hMSCs through cell cycle regulatory genes. © 2015 International Union of Biochemistry and Molecular Biology, Inc.

  7. Ascorbic acid improves brachial artery vasodilation during progressive handgrip exercise in the elderly through a nitric oxide-mediated mechanism.

    PubMed

    Trinity, Joel D; Wray, D Walter; Witman, Melissa A H; Layec, Gwenael; Barrett-O'Keefe, Zachary; Ives, Stephen J; Conklin, Jamie D; Reese, Van; Zhao, Jia; Richardson, Russell S

    2016-03-15

    The proposed mechanistic link between the age-related attenuation in vascular function and free radicals is an attractive hypothesis; however, direct evidence of free radical attenuation and a concomitant improvement in vascular function in the elderly is lacking. Therefore, this study sought to test the hypothesis that ascorbic acid (AA), administered intra-arterially during progressive handgrip exercise, improves brachial artery (BA) vasodilation in a nitric oxide (NO)-dependent manner, by mitigating free radical production. BA vasodilation (Doppler ultrasound) and free radical outflow [electron paramagnetic resonance (EPR) spectroscopy] were measured in seven healthy older adults (69 ± 2 yr) during handgrip exercise at 3, 6, 9, and 12 kg (∼13-52% of maximal voluntary contraction) during the control condition and nitric oxide synthase (NOS) inhibition via N(G)-monomethyl-L-arginine (L-NMMA), AA, and coinfusion of l-NMMA + AA. Baseline BA diameter was not altered by any of the treatments, while L-NMMA and L-NMMA + AA diminished baseline BA blood flow and shear rate. AA improved BA dilation compared with control at 9 kg (control: 6.5 ± 2.2%, AA: 10.9 ± 2.5%, P = 0.01) and 12 kg (control: 9.5 ± 2.7%, AA: 15.9 ± 3.7%, P < 0.01). NOS inhibition blunted BA vasodilation compared with control and when combined with AA eliminated the AA-induced improvement in BA vasodilation. Free radical outflow increased with exercise intensity but, interestingly, was not attenuated by AA. Collectively, these results indicate that AA improves BA vasodilation in the elderly during handgrip exercise through an NO-dependent mechanism; however, this improvement appears not to be the direct consequence of attenuated free radical outflow from the forearm.

  8. Ascorbic acid improves brachial artery vasodilation during progressive handgrip exercise in the elderly through a nitric oxide-mediated mechanism

    PubMed Central

    Wray, D. Walter; Witman, Melissa A. H.; Layec, Gwenael; Barrett-O'Keefe, Zachary; Ives, Stephen J.; Conklin, Jamie D.; Reese, Van; Zhao, Jia; Richardson, Russell S.

    2016-01-01

    The proposed mechanistic link between the age-related attenuation in vascular function and free radicals is an attractive hypothesis; however, direct evidence of free radical attenuation and a concomitant improvement in vascular function in the elderly is lacking. Therefore, this study sought to test the hypothesis that ascorbic acid (AA), administered intra-arterially during progressive handgrip exercise, improves brachial artery (BA) vasodilation in a nitric oxide (NO)-dependent manner, by mitigating free radical production. BA vasodilation (Doppler ultrasound) and free radical outflow [electron paramagnetic resonance (EPR) spectroscopy] were measured in seven healthy older adults (69 ± 2 yr) during handgrip exercise at 3, 6, 9, and 12 kg (∼13–52% of maximal voluntary contraction) during the control condition and nitric oxide synthase (NOS) inhibition via NG-monomethyl-l-arginine (l-NMMA), AA, and coinfusion of l-NMMA + AA. Baseline BA diameter was not altered by any of the treatments, while l-NMMA and l-NMMA + AA diminished baseline BA blood flow and shear rate. AA improved BA dilation compared with control at 9 kg (control: 6.5 ± 2.2%, AA: 10.9 ± 2.5%, P = 0.01) and 12 kg (control: 9.5 ± 2.7%, AA: 15.9 ± 3.7%, P < 0.01). NOS inhibition blunted BA vasodilation compared with control and when combined with AA eliminated the AA-induced improvement in BA vasodilation. Free radical outflow increased with exercise intensity but, interestingly, was not attenuated by AA. Collectively, these results indicate that AA improves BA vasodilation in the elderly during handgrip exercise through an NO-dependent mechanism; however, this improvement appears not to be the direct consequence of attenuated free radical outflow from the forearm. PMID:26801312

  9. Melatonin ameliorates oxidative stress, inflammation, proteinuria, and progression of renal damage in rats with renal mass reduction.

    PubMed

    Quiroz, Yasmir; Ferrebuz, Atilio; Romero, Freddy; Vaziri, Nosratola D; Rodriguez-Iturbe, Bernardo

    2008-02-01

    The progressive deterioration of renal function and structure resulting from renal mass reduction are mediated by a variety of mechanisms, including oxidative stress and inflammation. Melatonin, the major product of the pineal gland, has potent_antioxidant and anti-inflammatory properties, and its production is impaired in chronic renal failure. We therefore investigated if melatonin treatment would modify the course of chronic renal failure in the remnant kidney model. We studied rats followed 12 wk after renal ablation untreated (Nx group, n = 7) and treated with melatonin administered in the drinking water (10 mg/100 ml) (Nx + MEL group, n = 8). Sham-operated rats (n = 10) were used as controls. Melatonin administration increased 13-15 times the endogenous hormone levels. Rats in the Nx + MEL group had reduced oxidative stress (malondialdehyde levels in plasma and in the remnant kidney as well as nitrotyrosine renal abundance) and renal inflammation (p65 nuclear factor-kappaB-positive renal interstitial cells and infiltration of lymphocytes and macrophages). Collagen, alpha-smooth muscle actin, and transforming growth factor-beta renal abundance were all increased in the remnant kidney of the untreated rats and were reduced significantly by melatonin treatment. Deterioration of renal function (plasma creatinine and proteinuria) and structure (glomerulosclerosis and tubulointerstitial damage) resulting from renal ablation were ameliorated significantly with melatonin treatment. In conclusion, melatonin administration improves the course of chronic renal failure in rats with renal mass reduction. Further studies are necessary to define the potential usefulness of this treatment in other animal models and in patients with chronic renal disease.

  10. UP2 400 High Activity Oxide Legacy Waste Retrieval Project Scope and Progress-13048

    SciTech Connect

    Chabeuf, Jean-Michel; Varet, Thierry

    2013-07-01

    The High Activity Oxide facility (HAO) reprocessed sheared and dissolved 4500 metric tons of light water reactor fuel the fuel of the emerging light water reactor spent fuel between 1976 and 1998. Over the period, approximately 2200 tons of process waste, composed primarily of sheared hulls, was produced and stored in a vast silo in the first place, and in canisters stored in pools in subsequent years. Upon shutdown of the facility, AREVA D and D Division in La Hague launched a thorough investigation and characterization of the silos and pools content, which then served as input data for the definition of a legacy waste retrieval and reconditioning program. Basic design was conducted between 2005 and 2007, and was followed by an optimization phase which lead to the definition of a final scenario and budget, 12% under the initial estimates. The scenario planned for the construction of a retrieval and reconditioning cell to be built on top of the storage silo. The retrieved waste would then be rinsed and sorted, so that hulls could subsequently be sent to La Hague high activity compacting facility, while resins and sludge would be cemented within the retrieval cell. Detailed design was conducted successfully from 2008 until 2011, while a thorough research and development program was conducted in order to qualify each stage of the retrieval and reconditioning process, and assist in the elaboration of the final waste package specification. This R and D program was defined and conducted as a response and mitigation of the major project risks identified during the basic design process. Procurement and site preparatory works were then launched in 2011. By the end of 2012, R and D is nearly completed, the retrieval and reconditioning process have been secured, the final waste package specification is being completed, the first equipment for the retrieval cell is being delivered on site, while preparation works are allowing to free up space above and around the silo, to

  11. Mitochondrial oxidative stress drives tumor progression and metastasis: should we use antioxidants as a key component of cancer treatment and prevention?

    PubMed Central

    2011-01-01

    The functional role of oxidative stress in cancer pathogenesis has long been a hotly debated topic. A study published this month in BMC Cancer by Goh et al., directly addresses this issue by using a molecular genetic approach, via an established mouse animal model of human breast cancer. More specifically, alleviation of mitochondrial oxidative stress, via transgenic over-expression of catalase (an anti-oxidant enzyme) targeted to mitochondria, was sufficient to lower tumor grade (from high-to-low) and to dramatically reduce metastatic tumor burden by >12-fold. Here, we discuss these new findings and place them in the context of several other recent studies showing that oxidative stress directly contributes to tumor progression and metastasis. These results have important clinical and translational significance, as most current chemo-therapeutic agents and radiation therapy increase oxidative stress, and, therefore, could help drive tumor recurrence and metastasis. Similarly, chemo- and radiation-therapy both increase the risk for developing a secondary malignancy, such as leukemia and/or lymphoma. To effectively reduce mitochondrial oxidative stress, medical oncologists should now re-consider the use of powerful anti-oxidants as a key component of patient therapy and cancer prevention. Please see related research article: http://www.biomedcentral.com/1471-2407/11/191 PMID:21605374

  12. Superior catalysts for selective catalytic reduction of nitric oxide. Quarterly technical progress report, 1 January 1994--31 March 1994

    SciTech Connect

    Chen, J.P.; Cheng, L.S.; Hausladen, M.C.; Kikkinides, E.S.; Yang, R.T.

    1994-05-01

    During the past quarter, progress has been made in four tasks as summarized below: Task 1: A delaminated Fe{sub 2}O{sub 3} pillared clay was synthesized and carefully characterized. The chemical composition was measured by ICP atomic emission spectrometry. The structural changes in the clay as well as the iron oxide particle sizes were characterized by X-ray diffraction techniques. Task 2: The Selective Catalytic Reduction (SCR, i.e., NO reduction with NH{sub 3}) activities of the delaminated pillared clay were tested and compared with four other most active SCR catalysts: a commercial V{sub 2}O{sub 5} + WO{sub 3}/TiO{sub 2} catalyst, a Fe{sub 2}O{sub 3}-pillared clay, and two supported Fe{sub 2}O{sub 3} catalysts (on Al{sub 2}O{sub 3} and TiO{sub 2}). The delaminated Fe{sub 2}O{sub 3} pillared clay exhibited the highest SCR activities. Catalyst stability test showed that the delaminated sample was also stable. Task 3: To further increase the SCR activity of the delaminated pillared clay, Cr{sub 2}O{sub 3} was doped as a promoter by incipient wetness. Task 4: Deactivation effects of SO{sub 2} and H{sub 2}O on the SCR activities of the delaminated Fe{sub 2}O{sub 3} pillared clay were studied, and compared with other SCR catalysts. The delaminated clay catalyst showed the least deactivation.

  13. A Small Molecule Polyamine Oxidase Inhibitor Blocks Androgen-Induced Oxidative Stress and Delays Prostate Cancer Progression in the TRAMP Mouse Model

    PubMed Central

    Basu, Hirak S.; Thompson, Todd A.; Church, Dawn R.; Clower, Cynthia C.; Mehraein-Ghomi, Farideh; Amlong, Corey A.; Martin, Christopher T.; Woster, Patrick M.; Lindstrom, Mary J.; Wilding, George

    2009-01-01

    High levels of reactive oxygen species (ROS) present in human prostate epithelia are an important etiological factor in prostate cancer (CaP) occurrence, recurrence and progression. Androgen induces ROS production in the prostate by a yet unknown mechanism. Here, to the best of our knowledge, we report for the first time that androgen induces an overexpression of spermidine/spermine N1-acetyltransferase (SSAT), the rate-limiting enzyme in the polyamine oxidation pathway. As prostatic epithelia produce a large excess of polyamines, the androgen-induced polyamine oxidation that produces H2O2 could be a major reason for the high ROS levels in the prostate epithelia. A small molecule polyamine oxidase inhibitor N,N'-butanedienyl butanediamine (MDL 72,527 or CPC-200) effectively blocks androgen-induced ROS production in human CaP cells as well as significantly delays CaP progression and death in animals developing spontaneous CaP. These data demonstrate that polyamine oxidation is not only a major pathway for ROS production in prostate, but inhibiting this pathway also successfully delays prostate cancer progression. PMID:19773450

  14. A small molecule polyamine oxidase inhibitor blocks androgen-induced oxidative stress and delays prostate cancer progression in the transgenic adenocarcinoma of the mouse prostate model.

    PubMed

    Basu, Hirak S; Thompson, Todd A; Church, Dawn R; Clower, Cynthia C; Mehraein-Ghomi, Farideh; Amlong, Corey A; Martin, Christopher T; Woster, Patrick M; Lindstrom, Mary J; Wilding, George

    2009-10-01

    High levels of reactive oxygen species (ROS) present in human prostate epithelia are an important etiologic factor in prostate cancer (CaP) occurrence, recurrence, and progression. Androgen induces ROS production in the prostate by a yet unknown mechanism. Here, to the best of our knowledge, we report for the first time that androgen induces an overexpression of spermidine/spermine N1-acetyltransferase, the rate-limiting enzyme in the polyamine oxidation pathway. As prostatic epithelia produce a large excess of polyamines, the androgen-induced polyamine oxidation that produces H2O2 could be a major reason for the high ROS levels in the prostate epithelia. A small molecule polyamine oxidase inhibitor N,N'-butanedienyl butanediamine (MDL 72,527 or CPC-200) effectively blocks androgen-induced ROS production in human CaP cells, as well as significantly delays CaP progression and death in animals developing spontaneous CaP. These data show that polyamine oxidation is not only a major pathway for ROS production in prostate, but inhibiting this pathway also successfully delays CaP progression.

  15. Fundamental studies of stress distributions and stress relaxation in oxide scales on high temperature alloys. [Final progress report

    SciTech Connect

    Shores, D.A.; Stout, J.H.; Gerberich, W.W.

    1993-06-01

    This report summarizes a three-year study of stresses arising in the oxide scale and underlying metal during high temperature oxidation and of scale cracking. In-situ XRD was developed to measure strains during oxidation over 1000{degrees}C on pure metals. Acoustic emission was used to observe scale fracture during isothermal oxidation and cooling, and statistical analysis was used to infer mechanical aspects of cracking. A microscratch technique was used to measure the fracture toughness of scale/metal interface. A theoretical model was evaluated for the development and relaxation of stresses in scale and metal substrate during oxidation.

  16. Relationship of Oxidative Stress with HIV Disease Progression in HIV/HCV Co-infected and HIV Mono-infected Adults in Miami

    PubMed Central

    Shin, Dong-Ho; Martinez, Sabrina S.; Parsons, Mary; Jayaweera, Dushyantha T.; Campa, Adriana; Baum, Marianna K.

    2013-01-01

    Background HIV and HCV infections are both characterized by increased oxidative stress. Information on the magnitude of this increase and its consequences in HIV/HCV co-infection and viral replication is limited. We investigated the relationship between oxidative stress and HIV-progression in HIV/HCV co-infected and HIV mono-infected adults. Methods 106 HIV/HCV co-infected and 115 HIV mono-infected participants provided demographic information and blood to determine 8-oxo-dG and percent oxidized glutathione. Results HIV/HCV co-infected subjects had higher percent oxidized glutathione, higher HIV viral load, lower mtDNA copies and higher liver fibrosis than mono-infected subjects. In a small sample of HIV/HCV co-infected participants with liver biopsy, 8-oxo-dG was significantly lower in participants with low fibrosis scores than those with high fibrosis scores, and the grade of inflammation was strongly associated with oxidized glutathione. Conclusions HIV/HCV co-infection seems to diminish the capacity of the antioxidant system to control oxidative stress, and increases HIV replication. PMID:23504530

  17. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report, [June--August 1993

    SciTech Connect

    Doyle, F.M.

    1993-09-30

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. The results will provide fundamental insight into oxidation, in term of the bulk and surface chemistry, the microstructure, and the semiconductor properties of the pyrite. During the twelfth quarter, wet and dry oxidation tests were done at room temperature on coal samples from the Pennsylvania State Coal Bank. Previous results had indicated that oxidation at high temperatures induced changes in surface properties through loss of volatiles. As-received and oxidized coal samples were studied by ion exchange methods to determine the carboxylate and phenolic group concentrations. Film flotation tests were done to characterize the floatability of as-received and oxidized coals. Surface area measurements were done on as-received coals.

  18. Oxidative Stress during the Progression of β-Amyloid Pathology in the Neocortex of the Tg2576 Mouse Model of Alzheimer's Disease.

    PubMed

    Porcellotti, Sara; Fanelli, Francesca; Fracassi, Anna; Sepe, Sara; Cecconi, Francesco; Bernardi, Cinzia; Cimini, AnnaMaria; Cerù, Maria Paola; Moreno, Sandra

    2015-01-01

    Alzheimer's disease (AD) is the most common form of dementia, characterized by progressive neurodegeneration. Pathogenetic mechanisms, triggered by β-amyloid (Aβ) accumulation, include oxidative stress, derived from energy homeostasis deregulation and involving mitochondria and peroxisomes. We here addressed the oxidative stress status and the elicited cellular response at the onset and during the progression of Aβ pathology, studying the neocortex of Tg2576 model of AD. Age-dependent changes of oxidative damage markers, antioxidant enzymes, and related transcription factors were analysed in relation to the distribution of Aβ peptide and oligomers, by a combined molecular/morphological approach. Nucleic acid oxidative damage, accompanied by defective antioxidant defences, and decreased PGC1α expression are already detected in 3-month-old Tg2576 neurons. Conversely, PPARα is increased in these cells, with its cytoplasmic localization suggesting nongenomic, anti-inflammatory actions. At 6 months, when intracellular Aβ accumulates, PMP70 is downregulated, indicating impairment of fatty acids peroxisomal translocation and their consequent harmful accumulation. In 9-month-old Tg2576 neocortex, Aβ oligomers and acrolein deposition correlate with GFAP, GPX1, and PMP70 increases, supporting a compensatory response, involving astroglial peroxisomes. At severe pathological stages, when senile plaques disrupt cortical cytoarchitecture, antioxidant capacity is gradually lost. Overall, our data suggest early therapeutic intervention in AD, also targeting peroxisomes.

  19. Oxidative Stress during the Progression of β-Amyloid Pathology in the Neocortex of the Tg2576 Mouse Model of Alzheimer's Disease

    PubMed Central

    Porcellotti, Sara; Fanelli, Francesca; Fracassi, Anna; Sepe, Sara; Cecconi, Francesco; Bernardi, Cinzia; Cimini, AnnaMaria; Cerù, Maria Paola; Moreno, Sandra

    2015-01-01

    Alzheimer's disease (AD) is the most common form of dementia, characterized by progressive neurodegeneration. Pathogenetic mechanisms, triggered by β-amyloid (Aβ) accumulation, include oxidative stress, derived from energy homeostasis deregulation and involving mitochondria and peroxisomes. We here addressed the oxidative stress status and the elicited cellular response at the onset and during the progression of Aβ pathology, studying the neocortex of Tg2576 model of AD. Age-dependent changes of oxidative damage markers, antioxidant enzymes, and related transcription factors were analysed in relation to the distribution of Aβ peptide and oligomers, by a combined molecular/morphological approach. Nucleic acid oxidative damage, accompanied by defective antioxidant defences, and decreased PGC1α expression are already detected in 3-month-old Tg2576 neurons. Conversely, PPARα is increased in these cells, with its cytoplasmic localization suggesting nongenomic, anti-inflammatory actions. At 6 months, when intracellular Aβ accumulates, PMP70 is downregulated, indicating impairment of fatty acids peroxisomal translocation and their consequent harmful accumulation. In 9-month-old Tg2576 neocortex, Aβ oligomers and acrolein deposition correlate with GFAP, GPX1, and PMP70 increases, supporting a compensatory response, involving astroglial peroxisomes. At severe pathological stages, when senile plaques disrupt cortical cytoarchitecture, antioxidant capacity is gradually lost. Overall, our data suggest early therapeutic intervention in AD, also targeting peroxisomes. PMID:25973140

  20. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. [Quarterly] technical progress report, April--June 1993

    SciTech Connect

    Doyle, F.M.

    1993-06-30

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. The results will provide fundamental insight into oxidation, in terms of the bulk and surface chemistry, the microstructure, and the semiconductor properties of the pyrite. During the eleventh quarter, dry thermal oxidation tests were done on coal samples from the Pennsylvania State Coal Bank. As-received and oxidized coal samples were studied by ion-exchange methods to determine the carboxylate and phenolic group concentrations. Film flotation tests were done to characterize the flotability of as-received and oxidized coals. In addition, electrokinetic tests were done on different coals, to obtain information pertinent to the selection of flotation reagents. DRIFT analysis was done to characterize the structure of coals.

  1. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report, [September--December 1991

    SciTech Connect

    Doyle, F.M.

    1992-01-28

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical coal cleaning processes. The results will provide fundamental insight into oxidation, in terms of the bulk and surface chemistry, the microstructure, and the semiconductor properties of the pyrite. During the fifth quarter, wet chemical and dry oxidation tests were done on Upper Freeport coal from the Troutville {number_sign}2 Mine, Clearfield County, Pennsylvania.

  2. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report, [March--May 1992

    SciTech Connect

    Doyle, F.M.

    1992-06-30

    during the seventh quarter, electrokinetic, humic acid extraction and film flotation tests were done on oxidized samples of Upper Freeport coal from the Troutville {number_sign} 2 Mine, Clearfield County, Pennsylvania. Scanning electron microscopy and energy dispersive X-ray analysis was done to characterize the morphology and composition of the surface of as-received coal, oxidized coal, oxidized coal after extraction of humic acids and humic acid extracted from oxidized coal. In addition, electrochemical studies were done on electrodes prepared from coal pyrite samples.

  3. Superior catalysts for selective catalytic reduction of nitric oxide. Quarterly technical progress report, April 1, 1995--June 30, 1995

    SciTech Connect

    Li, W.B.; Yang, R.T.

    1995-12-01

    Efforts continued towards the synthesis of new pillared clay catalysts for the selective catalytic reduction of nitric oxide by ammonia. The possibility of utilizing hydrocarbons was also investigated.

  4. Inflammation and oxidative stress are elevated in the brain, blood, and adrenal glands during the progression of post-traumatic stress disorder in a predator exposure animal model.

    PubMed

    Wilson, C Brad; McLaughlin, Leslie D; Nair, Anand; Ebenezer, Philip J; Dange, Rahul; Francis, Joseph

    2013-01-01

    This study sought to analyze specific pathophysiological mechanisms involved in the progression of post-traumatic stress disorder (PTSD) by utilizing an animal model. To examine PTSD pathophysiology, we measured damaging reactive oxygen species and inflammatory cytokines to determine if oxidative stress and inflammation in the brain, adrenal glands, and systemic circulation were upregulated in response to constant stress. Pre-clinical PTSD was induced in naïve, male Sprague-Dawley rats via a predator exposure/psychosocial stress regimen. PTSD group rats were secured in Plexiglas cylinders and placed in a cage with a cat for one hour on days 1 and 11 of a 31-day stress regimen. In addition, PTSD group rats were subjected to psychosocial stress whereby their cage cohort was changed daily. This model has been shown to cause heightened anxiety, exaggerated startle response, impaired cognition, and increased cardiovascular reactivity, all of which are common symptoms seen in humans with PTSD. At the conclusion of the predator exposure/psychosocial stress regimen, the rats were euthanized and their brains were dissected to remove the hippocampus, amygdala, and pre-frontal cortex (PFC), the three areas commonly associated with PTSD development. The adrenal glands and whole blood were also collected to assess systemic oxidative stress. Analysis of the whole blood, adrenal glands, and brain regions revealed oxidative stress increased during PTSD progression. In addition, examination of pro-inflammatory cytokine (PIC) mRNA and protein demonstrated neurological inflammatory molecules were significantly upregulated in the PTSD group vs. controls. These results indicate oxidative stress and inflammation in the brain, adrenal glands, and systemic circulation may play a critical role in the development and further exacerbation of PTSD. Thus, PTSD may not be solely a neurological pathology but may progress as a systemic condition involving multiple organ systems.

  5. Plasma Vascular Endothelial Growth Factor Concentration and Alveolar Nitric Oxide as Potential Predictors of Disease Progression and Mortality in Idiopathic Pulmonary Fibrosis

    PubMed Central

    Kotecha, Jalpa; Shulgina, Ludmila; Sexton, Darren W.; Atkins, Christopher P.; Wilson, Andrew M.

    2016-01-01

    Background: Declining lung function signifies disease progression in idiopathic pulmonary fibrosis (IPF). Vascular endothelial growth factor (VEGF) concentration is associated with declining lung function in 6 and 12-month studies. Alveolar nitric oxide concentration (CANO) is increased in patients with IPF, however its significance is unclear. This study investigated whether baseline plasma VEGF concentration and CANO are associated with disease progression or mortality in IPF. Methods: 27 IPF patients were studied (maximum follow-up 65 months). Baseline plasma VEGF concentration, CANO and pulmonary function tests (PFTs) were measured. PFTs were performed the preceding year and subsequent PFTs and data regarding mortality were collected. Disease progression was defined as one of: death, relative decrease of ≥10% in baseline forced vital capacity (FVC) % predicted, or relative decrease of ≥15% in baseline single breath diffusion capacity of carbon monoxide (TLCO-SB) % predicted. Results: Plasma VEGF concentration was not associated with progression-free survival or mortality. There was a trend towards shorter time to disease progression and death with higher CANO. CANO was significantly higher in patients with previous declining versus stable lung function. Conclusion: The role of VEGF in IPF remains uncertain. It may be of value to further investigate CANO in IPF. PMID:27618114

  6. Protective action of aqueous black tea (Camellia sinensis) extract (BTE) against ovariectomy-induced oxidative stress of mononuclear cells and its associated progression of bone loss.

    PubMed

    Das, Asankur Sekhar; Mukherjee, Maitrayee; Das, Dolan; Mitra, Chandan

    2009-09-01

    The protective action of aqueous black tea extract (BTE) against ovariectomy-induced oxidative stress of mononuclear cells and its associated progression of bone loss was demonstrated in this study. Eighteen female adult 6-month-old Wistar albino rats were divided into three groups: sham-control (A), bilaterally ovariectomized (B) and bilaterally ovariectomized + BTE supplemented (C). Studies included the measurement of oxidative (nitric oxide, lipid peroxidation) and antioxidative (superoxide dismutase, catalase) markers, inflammatory cytokines (IL-6, TNF-alpha), osteoclast differentiation factor (RANKL) and bone resorption markers (tartrate-resistant acid phosphatase and hydroxyproline). Also quantitative histomorphometry and histological studies were undertaken. The bone breaking force was measured. The results indicate that BTE was effective in preserving and restoring skeletal health by reducing the number of active osteoclasts. Such changes with BTE supplementation were steadily linked with the reduced oxidative stress of mononuclear cells, serum levels of bone resorbing cytokines, osteoclast differentiation factor and resorption markers. The results of the bone breaking force, histological and histomorphometric analyses further supported the hypothesis. This study suggests that BTE has both protective and restorative actions against ovariectomy-induced mononuclear cell oxidative stress and associated bone loss.

  7. Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report 10, July 1, 1995--September 31, 1995

    SciTech Connect

    McCormick, R.L.

    1995-12-07

    This document is the tenth quarterly technical progress report under Contract No. DE-AC22-92PC92110 {open_quotes}Development of Vanadium-Phosphate Catalysts for Methanol Production by Selective Oxidation of Methane{close_quotes}. Activities focused on testing of additional modified and promoted catalysts and characterization of these materials. Attempts at improving the sensitivity of our GC based analytical systems were also made with some success. Methanol oxidation studies were initiated. These results are reported. Specific accomplishments include: (1) Methane oxidation testing of a suite of catalysts promoted with most of the first row transition metals was completed. Several of these materials produced low, difficult to quantify yields of formaldehyde. (2) Characterization of these materials by XRD and FTIR was performed with the goal of correlating activity and selectivity with catalyst properties. (3) We began to characterize catalysts prepared via modified synthesis methods designed to enhance acidity using TGA measurements of acetonitrile chemisorption and methanol dehydration to dimethyl ether as a test reaction. (4) A catalyst prepared in the presence of naphthalene methanol as a structural disrupter was tested for activity in methane oxidation. It was found that this material produced low yields of formaldehyde which were difficult to quantify. (5) Preparation of catalysts with no Bronsted acid sites. This was accomplished by replacement of exchangeable protons with potassium, and (6) Methanol oxidation studies were initiated to provide an indication of catalyst activity for decomposition of this desired product and as a method of characterizing the catalyst surface.

  8. Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report No. 13, April 1996--June 1996

    SciTech Connect

    McCormick, R.L.; Alptekin, G.O.

    1996-07-30

    This document is the thirteenth quarterly technical progress report under Contract No. DE-AC22-92PC92110 {open_quotes}Development of Vanadium-Phosphate Catalysts for Methanol Production by Selective Oxidation of Methane{close_quotes} and covers the period April-June 1996. The basic premise of this project is that vanadyl pyrophosphate (VPO), a catalyst used commercially in the selective oxidation of butane to maleic anhydride, can be developed as a catalyst for selective methane oxidation. Data supporting this idea include published reports indicating moderate to high selectivity in oxidation of ethane, propane, and pentane, as well as butane. Methane oxidation is a much more difficult reaction to catalyze than that of other alkanes and it is expected that considerable modification of vanadyl pyrophosphate will be required for this application. It is well known that VPO can be modified extensively with a large number of different promoters and in particular that promoters can enhance selectivity and lower the temperature required for butane conversion.

  9. Epoetin beta pegol alleviates oxidative stress and exacerbation of renal damage from iron deposition, thereby delaying CKD progression in progressive glomerulonephritis rats.

    PubMed

    Hirata, Michinori; Tashiro, Yoshihito; Aizawa, Ken; Kawasaki, Ryohei; Shimonaka, Yasushi; Endo, Koichi

    2015-12-01

    The increased deposition of iron in the kidneys that occurs with glomerulopathy hinders the functional and structural recovery of the tubules and promotes progression of chronic kidney disease (CKD). Here, we evaluated whether epoetin beta pegol (continuous erythropoietin receptor activator: CERA), which has a long half-life in blood and strongly suppresses hepcidin-25, exerts renoprotection in a rat model of chronic progressive glomerulonephritis (cGN). cGN rats showed elevated urinary total protein excretion (uTP) and plasma urea nitrogen (UN) from day 14 after the induction of kidney disease (day 0) and finally declined into end-stage kidney disease (ESKD), showing reduced creatinine clearance with glomerulosclerosis, tubular dilation, and tubulointerstitial fibrosis. A single dose of CERA given on day 1, but not on day 16, alleviated increasing uTP and UN, thereby delaying ESKD. In the initial disease phase, CERA significantly suppressed urinary 8-OHdG and liver-type fatty acid-binding protein (L-FABP), a tubular damage marker. CERA also inhibited elevated plasma hepcidin-25 levels and alleviated subsequent iron accumulation in kidneys in association with elevated urinary iron excretion and resulted in alleviation of growth of Ki67-positive tubular and glomerular cells. In addition, at day 28 when the exacerbation of uTP occurs, a significant correlation was observed between iron deposition in the kidney and urinary L-FABP. In our study, CERA mitigated increasing kidney damage, thereby delaying CKD progression in this glomerulonephritis rat model. Alleviation by CERA of the exacerbation of kidney damage could be attributable to mitigation of tubular damage that might occur with lowered iron deposition in tubules. © 2015 Chugai Pharmaceutical Co., Ltd. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  10. Correlation of TGF-β1 and oxidative stress in the blood of patients with melanoma: a clue to understanding melanoma progression?

    PubMed

    Santos Bernardes, Sara; de Souza-Neto, Fernando Pinheiro; Pasqual Melo, Gabriella; Guarnier, Flávia Alessandra; Marinello, Poliana Camila; Cecchini, Rubens; Cecchini, Alessandra L

    2016-08-01

    TGF-β1 and oxidative stress are involved in cancer progression, but in melanoma, their role is still controversial. Our aim was to correlate plasma TGF-β1 levels and systemic oxidative stress biomarkers in patients with melanoma, with or without disease metastasis, to understand their participation in melanoma progression. Thirty patients were recruited for melanoma surveillance, together with 30 healthy volunteers. Patients were divided into two groups: Non-metastasis, comprising patients with tumor removal and no metastatic episode for 3 years; and Metastasis, comprising patients with a metastatic episode. The plasmatic cytokines TGF-β1, IL-1 β, and TNF-α were analyzed by ELISA. For oxidative stress, the following assays were performed: malondialdehyde (MDA), advanced oxidation protein products (AOPP) levels, total radical-trapping antioxidant parameter (TRAP) and thiol in plasma, and lipid peroxidation, SOD and catalase activity and GSH in erythrocytes. Patients with a metastatic episode had less circulating TGF-β1 and increased TRAP, thiol, AOPP and lipid peroxidation levels. MDA was increased in both melanoma groups, while catalase, GSH, and IL-1β was decreased in Non-metastasis patients. Significant negative correlations were observed between TGF-β1 levels and systemic MDA, and TGF-β1 levels and systemic AOPP, while a positive correlation was observed between TGF-β1 levels and erythrocyte GSH. Lower levels of TGF-β1 were related to increased oxidative stress in Metastasis patients, reinforcing new evidence that in melanoma TGF-β1 acts as a tumor suppressor, inhibiting tumor relapse. These findings provide new knowledge concerning this cancer pathophysiology, extending the possibilities of investigating new therapies based on this evidence.

  11. [Fundamental studies in oxidation-reduction in relation to water photolysis]. Progress report, June 26, 1989--November 1, 1990

    SciTech Connect

    Hurst, J.K.

    1990-12-31

    Objective is to solve problems in photoredox catalysis pertinent to developing membrane-base photoconversion/photostorage systems. The research is divided into: Physical studies (light scattering) on viologen-doped vesicles, transmembrane oxidation-reduction mechanisms, interfacial charge recombination, water oxidation catalysts.

  12. Controlling of incipient oxidation of pyrite for improved rejection. Sixth quarterly technical progress report, January 1, 1994--March 31, 1994

    SciTech Connect

    Yoon, R.H.; Richardson, P.E.

    1994-07-01

    The major objectives of this work are (1) to determine the Eh-pH conditions under which pyrite is stable, (2) to determine the mechanism of the initial stages of pyrite oxidation, and (3) to determine if the semiconducting properties of pyrite affect its oxidation behavior. It is known that moderate oxidation of pyrite produces a hydrophobic surface product. This hydrophobic product makes it extremely difficult to depress pyrite in coal flotation circuits. The eventual objective of this work is to prevent pyrite oxidation in order to better depress pyrite in coal flotation circuits. In this work clean, unoxidized pyrite surfaces are being produced by fracturing pyrite electrodes in an electrochemical cell. It has been shown that by holding the potential at different values during fracture and measuring the current passed at fracture, pyrite oxidation or reduction can be precisely controlled, or prevented. It has also been found that fresh pyrite surfaces, created by fracture in an electrochemical cell, begin to oxidize at potentials that are about 200 mV more negative than the potentials reported in the literature for pyrite oxidation. This is attributed to the fact that most work on pyrite has employed polished electrodes that have preexisting oxidation products on the surface. Electrochemical reduction and oxidation of these preexisting products essentially mask the oxidation of pyrite itselL In addition, photocurrent measurements show that freshly-fractured pyrite surfaces are charged negatively. This negative charge is believed to result from an intrinsic, acceptor-like surface state. This report period, voltammetric and photocurrent studies have been carried out as a function of pH and the photoresponse of pyrites from different sources have been determined.

  13. Studies of incipient oxidation of pyrite for improved rejection. Seventh quarterly technical progress report, April 1, 1994--June 30, 1994

    SciTech Connect

    Yoon, R.H.; Richardson, P.E.

    1994-10-01

    The major objectives of this work are (i) to determine the Eh-pH conditions under which pyrite is stable, (ii) to determine the mechanism of the initial stages of pyrite oxidation, and (iii) to determine if the semiconducting properties of pyrite effects its oxidation behavior. It is known that moderate oxidation of pyrite produces a hydrophobic surface product. This hydrophobic product makes it extremely difficult to depress pyrite in coal flotation circuits. The eventual objective of this work is to prevent pyrite oxidation in order to better depress pyrite in coal flotation circuits. In this work clean, unoxidized pyrite surfaces are being produced by fracturing pyrite electrodes in an electrochemical cell. It has been shown that by holding the potential at different values during fracture and measuring the current passed at fracture, pyrite oxidation or reduction can be precisely controlled, or prevented. It has also been found that fresh pyrite surfaces created by fracture in an electrochemical cell begin to oxidize at potentials that are about 200 mV more negative than the potentials reported in the literature for pyrite oxidation. This is attributed to the fact that most work on pyrite has employed polished electrodes that have pre-existing oxidation products on the surface. Electrochemical reduction and oxidation of these pre-existing products essentially mask the oxidation of pyrite itself. In addition, photocurrent measurements show that freshly fractured pyrite surfaces are charged negatively. This negative charge is believed to result from an intrinsic, acceptor-like surface state. This report period, electrochemical impedance spectroscopy (EIS) has been conducted on pyrite from different sources. In addition, EIS studies have been conducted on an electrode that was first fractured in situ and then polished.

  14. Astaxanthin protects against early burn-wound progression in rats by attenuating oxidative stress-induced inflammation and mitochondria-related apoptosis

    PubMed Central

    Fang, Quan; Guo, Songxue; Zhou, Hanlei; Han, Rui; Wu, Pan; Han, Chunmao

    2017-01-01

    Burn-wound progression can occur in the initial or peri-burn area after a deep burn injury. The stasis zone has a higher risk of deterioration mediated by multiple factors but is also considered salvageable. Astaxanthin (ATX), which is extracted from some marine organisms, is a natural compound with a strong antioxidant effect that has been reported to attenuate organ injuries caused by traumatic injuries. Hence, we investigated the potential effects of ATX on preventing early burn-wound progression. A classic “comb” burn rat model was established in this study for histological and biological assessments, which revealed that ATX, particularly higher doses, alleviated histological deterioration in the stasis zone. Additionally, we observed dose-dependent improvements in oxidative stress and the release of inflammatory mediators after ATX treatment. Furthermore, ATX dose-dependently attenuated burn-induced apoptosis in the wound areas, and this effect was accompanied by increases in Akt and Bad phosphorylation and a downregulation of cytochrome C and caspase expression. In addition, the administration of Ly 294002 further verified the effect of ATX. In summary, we demonstrated that ATX protected against early burn-wound progression in a rat deep-burn model. This protection might be mediated by the attenuation of oxidative stress-induced inflammation and mitochondria-related apoptosis. PMID:28128352

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

    PubMed

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

    2017-05-19

    Objectives The objective of the present study was to evaluate oxidative/nitrative stress in the plasma of 50 patients suffering from the secondary progressive course of multiple sclerosis (MS), and to verify its correlation with physical and mental disability as assessed by the Expanded Disability Status Scale (EDSS), and the Beck Depression Inventory (BDI). Methods Oxidative and nitrative damage to proteins was determined by the level of carbonyl groups and 3-nitrotyrosine using ELISA test. Based on the reaction with Ellman's reagent, we estimated the concentration of oxidized thiol groups. Additionally, we measured the level of lipid peroxidation. Results In plasma drawn from MS patients, we observed a significantly higher level of 3-NT (92%; P < 0.0003), carbonyl groups (29%; P < 0.0001) and thiobarbituric acid reactive substances (73%; P < 0.0001), as well as a lower concentration of thiol groups (33%; P < 0.0001), in comparison to healthy subjects. We noted positive correlations between the level of carbonyl groups or 3-NT and both diagnostic parameters, EDSS and BDI. Negative correlations were observed between concentration of -SH groups and EDSS and BDI. Conclusion Our results indicate that impaired red-ox balance can significantly promote neurodegeneration in secondary progressive MS.

  16. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report, May 31, 1995

    SciTech Connect

    Doyle, F.M.

    1995-12-31

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. Work during the nineteenth quarter has concluded studies of the surface functional groups produced on coal by severe thermal and chemical oxidation, and on investigating the partition of metal ions between such strongly oxidized coal samples and aqueous solutions. This partitioning behavior was being followed to obtain further information on the chemistry of the coal surfaces after different oxidation treatments. Adsorption isotherms for the uptake of Cd{sup 2+} on coal oxidized by different methods were obtained, and these and the Cu{sup 2+} adsorption isotherms reported in the last report have been scrutinized, and interpreted more exhaustively. The apparent discrepancies noted in the last report for the analysis of surface functional groups have been investigated further. The adsorption behavior has been related to the surface chemistry of Upper Freeport coal oxidized by different methods.

  17. Microbial oxidation of aromatic sulfur and nitrogen containing constituents of fossil fuels. Progress report, August 1, 1980-April 1, 1981

    SciTech Connect

    Finnerty, W R

    1981-04-01

    Oxidative conversion of these S- and N-containing hydrocarbons to water-soluble S- or N-containing organic compounds has been achieved at conversion efficiencies in excess of 90% within 12 hours. Several bacterial species were isolated which attack oxidatively specific S- and N-containing constituents present in crude oil and synfuels. The bacterial-mediated oxidations are obligate aerobic reactions and effect the conversion of S- and N-containing constituents to water-soluble products with the sulfur and nitrogen atom remaining bound in covalent form in the water-soluble organic moiety. Dibenzothiophene and carbazole were used in the experiments.

  18. [Research progress in microbiological characteristics in combined N2 removal process by partial nitrification and anaerobic ammonium oxidation].

    PubMed

    Zhao, Zhi-Rui; Hou, Yan-Lin

    2014-07-01

    Partial nitrification and anaerobic ammonium oxidation is a very significant biological nitrogen removal technology for saving energy and carbon sources. The development of this technology and the community ecology of ammonia-oxidizing bacterium (AOB) and anaerobic ammonium- oxidizing bacteria (ANAOB) using molecular biological methods have attracted growing attention. The paper reviewed the technological mechanism and the effects of key factors such as temperature, pH, dissolve oxygen and free ammonia on the distribution of AOB and ANAOB. It was also introduced that the populations of AOB and ANAOB species and their abundance in various environments. At the end, some suggestions were provided for the development of this technology in the future.

  19. Interleukin 6 Is Required for Pancreatic Cancer Progression by Promoting MAPK Signaling Activation and Oxidative Stress Resistance

    PubMed Central

    Zhang, Yaqing; Yan, Wei; Collins, Meredith A.; Bednar, Filip; Rakshit, Sabita; Zetter, Bruce R.; Stanger, Ben Z.; Chung, Ivy; Rhim, Andrew D.; di Magliano, Marina Pasca

    2013-01-01

    Pancreatic cancer, one of the deadliest human malignancies, is almost invariably associated with the presence of an oncogenic form of Kras. Mice expressing oncogenic Kras in the pancreas recapitulate the step-wise progression of the human disease. The inflammatory cytokine interleukin 6 (IL6) is often expressed by multiple cell types within the tumor microenvironment. Here, we show that IL6 is required for the maintenance and progression of pancreatic cancer precursor lesions. In fact, the lack of IL6 completely ablates cancer progression even in presence of oncogenic Kras. Mechanistically, we show that IL6 synergizes with oncogenic Kras to activate the reactive oxygen species (ROS) detoxification program downstream of the MAPK/ERK signaling cascade. In addition, IL6 regulates the inflammatory microenvironment of pancreatic cancer throughout its progression, providing several signals that are essential for carcinogenesis. Thus, IL6 emerges as a key player at all stages of pancreatic carcinogenesis, and a potential therapeutic target. PMID:24097820

  20. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report, September 30, 1992

    SciTech Connect

    Doyle, F.M.

    1992-12-31

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. The results will provide fundamental insight into oxidation, in terms of the bulk and surface chemistry, the microstructure, and the semiconductor properties of the pyrite. During the eighth quarter, wet chemical and dry oxidation tests were done on Upper Freeport coal from the Troutville {number_sign}2 Mine, Clearfield County, Pennsylvania. In addition electrochemical experiments were done on electrodes prepared from Upper Freeport coal pyrite and Pittsburgh coal pyrite samples provided by the US Bureau of Mines, Pittsburgh Research Center, Pennsylvania.

  1. Myocardial oxidative stress, osteogenic phenotype, and energy metabolism are differentially involved in the initiation and early progression of δ-sarcoglycan-null cardiomyopathy

    PubMed Central

    Missihoun, Comlan; Zisa, David; Shabbir, Arsalan; Lin, Huey

    2009-01-01

    Dilated cardiomyopathy (DCM) is a common cause of heart failure, and identification of early pathogenic events occurring prior to the onset of cardiac dysfunction is of mechanistic, diagnostic, and therapeutic importance. The work characterized early biochemical pathogenesis in TO2 strain hamsters lacking δ-sarcoglycan. Although the TO2 hamster heart exhibits normal function at 1 month of age (presymptomatic stage), elevated levels of myeloperoxidase, monocyte chemotactic protein-1, malondialdehyde, osteopontin, and alkaline phosphatase were evident, indicating the presence of inflammation, oxidative stress, and osteogenic phenotype. These changes were localized primarily to the myocardium. Derangement in energy metabolism was identified at the symptomatic stage (4 month), and is marked by attenuated activity and expression of pyruvate dehydrogenase E1 subunit, which catalyzes the rate-limiting step in aerobic glucose metabolism. Thus, this study illustrates differential involvement of oxidative stress, osteogenic phenotype, and glucose metabolism in the initiation and early progression of δ-sarcoglycan-null DCM. PMID:18726675

  2. Controlling incipient oxidation of pyrite for improved rejection. Eighth quarterly technical progress report, July 1, 1994--September 30, 1994

    SciTech Connect

    Yoon, R.H.; Richardson, P.E.

    1994-12-31

    The major objectives of this work are (1) to determine the Eh-pH conditions under which pyrite is stable, (2) to determine the mechanism of the initial stages of pyrite oxidation and (3) to determine if the semi-conducting properties of pyrite effects its oxidation behavior. It is known that moderate oxidation of pyrite produces a hydrophobic surface product. This hydrophobic product makes it extremely difficult to depress pyrite in coal flotation circuits. The eventual objective of this work is to prevent pyrite oxidation in order to better depress pyrite in coal flotation circuits. In this work clean, unoxidized pyrite surfaces are being produced by fracturing pyrite electrodes in an electrochemical cell. It has been shown that pyrite assumes a unique potential referred to as the ``stable potential`` at the instance it is fractured and that this potential is several hundred millivolts more negative than the steady state mixed potential of pyrite. It has also been shown that by holding the potential of pyrite at its stable potential during fracture, pyrite undergoes neither oxidation nor reduction. It has also been found that fresh pyrite surfaces created by fracture in an electrochemical begin to oxidize at potentials that are about 200 mV more negative than the potentials reported in the literature for pyrite oxidation. This is attributed to the fact that most work on pyrite has employed polished electrodes that have pre-existing oxidation products on the surface. The existence of a pH dependent stable potential for freshly fractured pyrite electrodes was based on studies conducted mainly on pyrite from Peru.

  3. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report, June 1995--August 1995

    SciTech Connect

    Doyle, F.M.

    1996-03-01

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. The action of coal and pyrite as reducing agents and as waste processing sorptive material for wastes outside the industry are also discussed.

  4. Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane: Quarterly technical progress report 15, October 1-December 31, 1996

    SciTech Connect

    McCormick, R.L., Alptekin, G.O.

    1997-04-02

    This document is the fifteenth quarterly technical progress report under Contract No. DE-AC22-92PC921 `Development of Vanadium- Phosphate Catalysts for Methanol Production by Selective Oxidation of Methane` and covers the period October-December, 1996. Vanadium phosphate, vanadyl pyrophosphate specifically, is used commercially to oxidize butane to maleic anhydride and is one of the few examples of an active and selective oxidation catalyst for alkanes. In this project we are examining this catalyst for the methane oxidation reaction. Initial process variable and kinetic studies indicated that vanadyl pyrophosphate is a reasonably active catalyst below 5000{degrees}C but produces CO as the primary product, no formaldehyde or methanol were observed. A number of approaches for modification of the phosphate catalyst to improve selectivity have been tried during this project. During this quarter we have obtained surface areas of catalysts prepared with modified surface acidity. The results confirm the enhanced activity of two of the modified preparations in methanol conversion (a test reaction for surface acid sites). In previous work we noted no improvement in methane oxidation selectivity for these catalysts. Surface areas, surface analysis by XPS, and bulk analysis by ICP-AA have been obtained for vanadyl pyrophosphate promoted by Cr, Cu, and Fe. These data indicate that roughly one tenth of the surface metal atoms are promoter. A similar analysis was obtained for the bulk. Preliminary examination of binding energies suggests a slightly more reduced surface for the Cr and Fe promoted catalysts which exhibit a significant selectivity to formaldehyde in methane oxidation. A more detailed kinetic model has also been developed to aid in comparing the promoted catalysts and is discussed. Plans for the coming months are outlined.

  5. Neutronics Benchmarks for the Utilization of Mixed-Oxide Fuel: Joint US/Russian Progress Report for Fiscal 1997. Volume 3 - Calculations Performed in the Russian Federation

    SciTech Connect

    1998-06-01

    This volume of the progress report provides documentation of reactor physics and criticality safety studies conducted in the Russian Federation during fiscal year 1997 and sponsored by the Fissile Materials Disposition Program of the US Department of Energy. Descriptions of computational and experimental benchmarks for the verification and validation of computer programs for neutron physics analyses are included. All benchmarks include either plutonium, uranium, or mixed uranium and plutonium fuels. Calculated physics parameters are reported for all of the contaminated benchmarks that the United States and Russia mutually agreed in November 1996 were applicable to mixed-oxide fuel cycles for light-water reactors.

  6. Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report 4, July--September 1993

    SciTech Connect

    McCormick, R.L.; Jha, M.C.; Streuber, R.D.

    1993-12-07

    This document is the fourth quarterly technical progress report under Contract No. DE-AC22-92PC92110, {open_quotes}Development of Vanadium-Phosphate Catalysts for Methanol Production by Selective Oxidation of Methane.{close_quotes} During this quarter, the authors focused primarily on catalyst activity testing in the microreactor. Additional blank runs using methane and methanol were performed. Initial attempts at preparing a silica supported catalyst are described. These results are discussed in detail and plans for the coming quarter are outlined.

  7. Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report No. 9, April 1995--June 1995

    SciTech Connect

    McCormick, R.L.

    1995-09-14

    This document is the ninth quarterly technical progress report under Contract No. DE-AC22-92PC92110 {open_quotes}Development of Vanadium-Phosphate Catalysts for Methanol Production by Selective Oxidation of Methane{close_quotes}. Activities were focused on fine tuning of the microreactor system by elimination of transport effects and improvements in the analytical system. Process variable studies were conducted on vanadyl pyrophosphate and screening studies were conducted on several modified catalyst. One additional catalyst was prepared and characterization studies continued. These results are reported.

  8. Impact of nitrogen flushing and oil choice on the progression of lipid oxidation in unwashed fried sliced potato crisps

    PubMed Central

    Marasca, E.; Greetham, D.; Herring, S.D.; Fisk, I.D.

    2016-01-01

    Unwashed, sliced, batch-fried potato crisps have a unique texture and are growing in popularity in the UK/EU premium snack food market. In this study, the storage stability of unwashed sliced (high surface starch) potatoes (crisps) fried in regular sunflower oil (SO) or in high oleic sunflower oil (HOSO) was compared over accelerated shelf life testing (45 °C, 6 weeks); with and without nitrogen gas flushing. Primary oxidation products (lipid hydroperoxides) were measured with a ferrous oxidation-xylenol orange (FOX) assay and volatile secondary oxidation products (hexanal) were quantified by using solid phase micro-extraction gas chromatography mass spectrometry (HS-SPME-GC/MS). Results revealed that crisps fried in SO were the least stable. Flushing the stored crisps with nitrogen gas proved to be effective in slowing down the oxidation rate after frying with sunflower oil, significantly stabilizing the crisps. However, crisps fried in HOSO were the most stable, with the lowest rate of development of oxidation markers, and this has previously not been shown for crisps with a high free starch content. PMID:26775947

  9. Impact of nitrogen flushing and oil choice on the progression of lipid oxidation in unwashed fried sliced potato crisps.

    PubMed

    Marasca, E; Greetham, D; Herring, S D; Fisk, I D

    2016-05-15

    Unwashed, sliced, batch-fried potato crisps have a unique texture and are growing in popularity in the UK/EU premium snack food market. In this study, the storage stability of unwashed sliced (high surface starch) potatoes (crisps) fried in regular sunflower oil (SO) or in high oleic sunflower oil (HOSO) was compared over accelerated shelf life testing (45°C, 6 weeks); with and without nitrogen gas flushing. Primary oxidation products (lipid hydroperoxides) were measured with a ferrous oxidation-xylenol orange (FOX) assay and volatile secondary oxidation products (hexanal) were quantified by using solid phase micro-extraction gas chromatography mass spectrometry (HS-SPME-GC/MS). Results revealed that crisps fried in SO were the least stable. Flushing the stored crisps with nitrogen gas proved to be effective in slowing down the oxidation rate after frying with sunflower oil, significantly stabilizing the crisps. However, crisps fried in HOSO were the most stable, with the lowest rate of development of oxidation markers, and this has previously not been shown for crisps with a high free starch content.

  10. Effect of GSTM1-Polymorphism on Disease Progression and Oxidative Stress in HIV Infection: Modulation by HIV/HCV Co-Infection and Alcohol Consumption

    PubMed Central

    Parsons, Mary; Campa, Adriana; Lai, Shenghan; Li, Yinghui; Martinez, Janet Diaz; Murillo, Jorge; Greer, Pedro; Martinez, Sabrina Sales; Baum, Marianna K

    2013-01-01

    Objective To examine the effects of GSTM1 null-allele polymorphism on oxidative stress and disease progression in HIV infected and HIV/hepatitis C (HCV) co-infected adults. Methods HIV-infected and HIV/HCV co-infected participants aged 40–60 years old with CD4 cell count >350 cells/ µl, were recruited. GSTM1 genotype was determined by quantitative PCR. Oxidative stress (mitochondrial 8-oxo-2’-deoxyguanosine [8-oxo-dG], malondialdehyde [MDA], oxidized glutathione and Complexes I and IV), apoptosis and HIV disease (CD4 count and viral load) markers were measured. Gene copies were not quantified, thus the Hardy-Weinberg formula was not applicable. Results Of the 129 HIV-infected participants, 58 were HIV/HCV co-infected. GSTM1 occurred in 66% (62/94) in those of African descent, and 33% (11/33) of the Caucasians. Those with GSTM1 coding for the functional antioxidant enzyme Glutathione S-transferase (GST), had higher CD4 cell count (β=3.48, p=0.034), lower HIV viral load (β=−0.536, p=0.018), and lower mitochondrial 8-oxo-dG (β=−0.28, p=0.03). ART reduced oxidative stress in the participants with the GSTM1 coding for the functional antioxidant enzyme. HIV/HCV co-infected participants with the GSTM1 coding for the functional antioxidant enzyme also had lower HIV viral load, lower 8-oxo-dG and lower rate of apoptosis, but also higher oxidized glutathione. Alcohol consumption was associated with lower HIV viral load but higher oxidized glutathione in those with the GSTM1 genotype coding for the functional antioxidant enzyme. Conclusion The GSTM1 genotype coding for the functional antioxidant enzyme is associated with lower HIV disease severity, and with lower oxidative stress, compared to GSTM1 null-allele polymorphism. HCV co-infection and alcohol use may be associated with increased oxidative stress even in the presence of the GSTM1 coding for the functional antioxidant enzyme. The null-gene, on the contrary, appears to have a detrimental effect on immune

  11. Development of vanidum-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report, 1996

    SciTech Connect

    McCormick, R.L.; Alptekin, G.O.

    1996-06-01

    Activities this past quarter, focused on acquisition of kinetic data for oxidation of formaldehyde and methanol on these catalysts. In the next quarter these results will be used to propose a simple reaction network and kinetic model. To date we have completed Task 1: Laboratory Setup and Task 2: Process Variable Study. Activities in the current quarter focused on finalizing these tasks and on Task 3: Promoters and Supports, this task is approximately 50% completed. Task 4: Advanced Catalysts is to be initiated in the next quarter. Specific accomplishments this quarter include: finalizing and calibrating a new reaction product analytical system with markedly improved precision and accuracy relative to older. approaches; development of procedures for accurately feeding formaldehyde to the reactor; examination of formaldehyde and methanol oxidation kinetics over vanadyl pyrophosphate at a range of temperatures; and preliminary studies of methane oxidation over a silica support.

  12. Studies of incipient oxidation of pyrite for improved rejection. Fifth quarterly technical progress report, October 1, 1993--December 31, 1993

    SciTech Connect

    Yoon, R.H.; Richardson, P.E.

    1993-12-31

    Oxidation of fresh surfaces of coal- and mineral-pyrite has been studied using electrochemical and photoelectrochemical techniques. This work was undertaken to better understand the oxidation processes that cause self-induced flotation of pyrite. Fresh surfaces were created by fracturing pyrite in situ, i.e., in solution. Chronoamperometry was used to determine the potential at which a newly created surface does not show oxidation or reduction currents. The ``stable`` potentials for pyrite are {minus}0.28 V (SHE) at pH 9.2 and 0 V at pH 4.6. Subsequent cyclic voltammograms show the incipient oxidation mechanism that involves the formation of sulfur products, which are believed to be hydrophobic. It is shown that the lower flotation edge of pyrite coincides with its incipient oxidation potential. The photocurrent generated at fractured pyrite surfaces by chopped illumination was used to determine the semiconducting characteristics of the electrodes. The results indicate that a spontaneous depletion layer is formed on the fresh surfaces of n-type pyrite. The depletion layer is attributed to an intrinsic, acceptor-like surface state. Charge storage in this surface state pins the band edges over a wide potential range, accounting for the metallic-like electrochemical behavior that has been reported for pyrite. The existence of an intrinsic surface state is consistent with XPS studies on pyrite surfaces prepared in vacuum, which reveal an FeS-like species in the surface region. During this report period, all of the data previously obtained has been analyzed in an attempt to better understand the mechanism of pyrite flotation with respect to its oxidation. The results of this analysis are included in this quarterly report. In addition, samples of pyrite from seven different sources were obtained. In situ fracture, photoelectrochemical and cyclic voltammetry studies have been conducted on electrodes made from these pyrites.

  13. Relationship between the Increased Haemostatic Properties of Blood Platelets and Oxidative Stress Level in Multiple Sclerosis Patients with the Secondary Progressive Stage.

    PubMed

    Morel, Agnieszka; Bijak, Michał; Miller, Elżbieta; Rywaniak, Joanna; Miller, Sergiusz; Saluk, Joanna

    2015-01-01

    Multiple sclerosis (MS) is the autoimmune disease of the central nervous system with complex pathogenesis, different clinical courses and recurrent neurological relapses and/or progression. Despite various scientific papers that focused on early stage of MS, our study targets selective group of late stage secondary progressive MS patients. The presented work is concerned with the reactivity of blood platelets in primary hemostasis in SP MS patients. 50 SP MS patients and 50 healthy volunteers (never diagnosed with MS or other chronic diseases) were examined to evaluate the biological activity of blood platelets (adhesion, aggregation), especially their response to the most important physiological agonists (thrombin, ADP, and collagen) and the effect of oxidative stress on platelet activity. We found that the blood platelets from SP MS patients were significantly more sensitive to all used agonists in comparison with control group. Moreover, the platelet hemostatic function was advanced in patients suffering from SP MS and positively correlated with increased production of O2 (-∙) in these cells, as well as with Expanded Disability Status Scale. We postulate that the increased oxidative stress in blood platelets in SP MS may be primarily responsible for the altered haemostatic properties of blood platelets.

  14. Relationship between the Increased Haemostatic Properties of Blood Platelets and Oxidative Stress Level in Multiple Sclerosis Patients with the Secondary Progressive Stage

    PubMed Central

    Bijak, Michał; Miller, Elżbieta; Miller, Sergiusz

    2015-01-01

    Multiple sclerosis (MS) is the autoimmune disease of the central nervous system with complex pathogenesis, different clinical courses and recurrent neurological relapses and/or progression. Despite various scientific papers that focused on early stage of MS, our study targets selective group of late stage secondary progressive MS patients. The presented work is concerned with the reactivity of blood platelets in primary hemostasis in SP MS patients. 50 SP MS patients and 50 healthy volunteers (never diagnosed with MS or other chronic diseases) were examined to evaluate the biological activity of blood platelets (adhesion, aggregation), especially their response to the most important physiological agonists (thrombin, ADP, and collagen) and the effect of oxidative stress on platelet activity. We found that the blood platelets from SP MS patients were significantly more sensitive to all used agonists in comparison with control group. Moreover, the platelet hemostatic function was advanced in patients suffering from SP MS and positively correlated with increased production of O2 −∙ in these cells, as well as with Expanded Disability Status Scale. We postulate that the increased oxidative stress in blood platelets in SP MS may be primarily responsible for the altered haemostatic properties of blood platelets. PMID:26064417

  15. Beneficial effects of silibinin against the progression of metabolic syndrome, increased oxidative stress, and liver steatosis in Psammomys obesus, a relevant animal model of human obesity and diabetes.

    PubMed

    Bouderba, Saida; Sanchez-Martin, Carlos; Villanueva, Gloria R; Detaille, Dominique; Koceïr, E Ahmed

    2014-03-01

    Insulin resistance and oxidative stress are major pathogenic mechanisms leading to chronic liver diseases in diabetic subjects. The gerbil Psammomys obesus is a unique model of nutritional diabetes resembling the disease in humans. This study investigated whether the natural ingredient silibinin, known as hepatoprotective, could decrease oxidative stress and reduce liver damage in obese gerbils. Control animals were fed their vegetable-based low caloric diet while two other rat groups ingested a high calorie diet for 14 weeks. Silibinin, or its vehicle, was administrated by gastric intubation (100 mg/kg per day) from the 7th week of treatment, which corresponds to an established insulin resistance state. At the end of the experiments, the hepatic biochemical profile, markers of oxidative stress in either plasma or liver tissue, and histological alterations were examined. Diabetic P. obesus displayed many metabolic disturbances (hyperinsulinemia, hyperglycemia, dyslipidemia), which were aggravated for the last 8 weeks. These events were coupled with greater oxidative stress (decline in glutathione, rise in lipoperoxidation). In addition, glutathione peroxidase activity was reduced while the level of superoxide dismutase was elevated. Interestingly, treatment with silibinin alleviated most of the metabolic defects, especially high triglyceride levels, reduced insulin resistance and largely restored antioxidant status. Also, Masson's trichrome staining revealed distinct steatosis, yet silibinin partially reversed this manifestation. Silibinin affords substantial protection against the progression of insulin resistance in Type 2 diabetes mellitus for P. obesus by hampering the oxidative process and improving hepatic metabolism. © 2013 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

  16. Modeling and experimental studies of oxide covered metal surfaces: TiO{sub 2}/Ti a model system. Progress report

    SciTech Connect

    Smyrl, W.H.

    1991-12-31

    Prior work in our laboratories at the Corrosion Research Center has shown that thin, anodic TiO{sub 2} films formed by the Slow Growth Mode (SGM) on polycrystalline titanium and microcrystalline with a texture that varies from one metal grain to another. Furthermore, the underlying metal grains are mapped by the photoelectrochemical response of the oxide. The same characteristics have also been demonstrated in our laboratory for ZnO grown on Zn. The TiO{sub 2}/Ti system has been chosen for study both because of its importance in energy systems, and because it can serve as a model system for other metal-metal oxide couples. The investigations of anodic TiO{sub 2} films on Ti have shown that the properties of thin films are consistent with the rutile form of the oxide. Both experimental data and theoretical calculations show the close resemblance to results on single crystal TiO{sub 2}. Furthermore, the modeling studies reveal that the optical transitions near the bandedge arise from the bulk band structure. The photoelectrochemical properties of anodic TiO{sub 2} films have now been shown to obey the simple Gaertner-Butler model for the semiconductor-electrolyte interface, with a few modifications. The most important deviation has now been shown to be a result of multiple internal reflections in the oxide film.

  17. Advanced alternate planar geometry solid oxide fuel cells. Interim quarterly technical progress report, November 1, 1988--January 31, 1989

    SciTech Connect

    Prouse, D.; Elangovan, S.; Khandkar, A.; Donelson, R.; Marianowski, L.

    1989-12-31

    During this quarter, progress was made at Ceramatec in seal development and conductivity measurements of YIG compositions. A creep test was completed on the porous/dense/porous triilayer. IGT provided a discussion on possible interconnect materials. The following tasks are reported on: cell design analysis, program liaison and test facility preparation, cell component fabrication/development, out-of-cell tests. 9 figs, 2 tabs.

  18. Solid-state, surface, and catalytic properties of oxides. Progress report, October 1, 1982-August 31, 1983

    SciTech Connect

    Kung, H.H.

    1983-09-01

    Effort has been concentrated in two directions: to elucidate the relationship between surface structure and surface chemical properties, and to investigate the effect of crystallite size. Briefly, by comparing the decomposition reactions of methanol, formaldehyde, and formic acid on the nonpolar and the Zn-polar surfaces of ZnO, it was found that the Zn-polar surface was more metallic-like than the nonpolar surface. On the nonpolar surface, defects always make the surface more reactive. In the study of the crystallite size effect, it was found that the selectivity for butadiene production in the oxidative dehydrogenation of butene on iron oxide increases with decreasing crystallite size, ranging from about 40% for very large crystallites to about 80% for very small crystallites. The nonequilibrium thermodynamics of methanol synthesis from syn-gas was studied.

  19. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report, December 31, 1992

    SciTech Connect

    Doyle, F.M.

    1992-12-31

    During the ninth quarter, electrochemical experiments were done on electrodes prepared from Upper Freeport coal pyrite and Pittsburgh coal pyrite samples provided by the US Bureau of Mines, Pittsburgh Research Center, Pennsylvania. Scanning electron microscopy and energy dispersive X-ray analysis were done to characterize the morphology and composition of the surface of as-received coal, oxidized coal and coal pyrite. In addition, electrokinetic tests were done on Upper Freeport coal pyrite.

  20. Enhanced sludge processing of HLW: Hydrothermal oxidation of chromium, technetium, and complexants by nitrate. 1997 mid-year progress report

    SciTech Connect

    Buelow, S.

    1997-06-01

    'Treatment of High Level Waste (HLW) is the second most costly problem identified by OEM. In order to minimize costs of disposal, the volume of HLW requiring vitrification and long term storage must be reduced. Methods for efficient separation of chromium from waste sludges, such as the Hanford Tank Wastes (HTW), are key to achieving this goal since the allowed level of chromium in high level glass controls waste loading. At concentrations above 0.5 to 1.0 wt.% chromium prevents proper vitrification of the waste. Chromium in sludges most likely exists as extremely insoluble oxides and minerals, with chromium in the plus III oxidation state [1]. In order to solubilize and separate it from other sludge components, Cr(III) must be oxidized to the more soluble Cr(VI) state. Efficient separation of chromium from HLW could produce an estimated savings of $3.4B[2]. Additionally, the efficient separation of technetium [3], TRU, and other metals may require the reformulation of solids to free trapped species as well as the destruction of organic complexants. New chemical processes are needed to separate chromium and other metals from tank wastes. Ideally they should not utilize additional reagents which would increase waste volume or require subsequent removal. The goal of this project is to apply hydrothermal processing for enhanced chromium separation from HLW sludges. Initially, the authors seek to develop a fundamental understanding of chromium speciation, oxidation/reduction and dissolution kinetics, reaction mechanisms, and transport properties under hydrothermal conditions in both simple and complex salt solutions. The authors also wish to evaluate the potential of hydrothermal processing for enhanced separations of technetium and TRU by examining technetium and TRU speciation at hydrothermal conditions optimal for chromium dissolution.'

  1. Nanostructured bismuth vanadate-based materials for solar-energy-driven water oxidation: a review on recent progress.

    PubMed

    Huang, Zhen-Feng; Pan, Lun; Zou, Ji-Jun; Zhang, Xiangwen; Wang, Li

    2014-11-06

    Water oxidation is the key step for both photocatalytic water splitting and CO₂ reduction, but its efficiency is very low compared with the photocatalytic reduction of water. Bismuth vanadate (BiVO₄) is the most promising photocatalyst for water oxidation and has become a hot topic for current research. However, the efficiency achieved with this material to date is far away from the theoretical solar-to-hydrogen conversion efficiency, mainly due to the poor photo-induced electron transportation and the slow kinetics of oxygen evolution. Fortunately, great breakthroughs have been made in the past five years in both improving the efficiency and understanding the related mechanism. This review is aimed at summarizing the recent experimental and computational breakthroughs in single crystals modified by element doping, facet engineering, and morphology control, as well as macro/mesoporous structure construction, and composites fabricated by homo/hetero-junction construction and co-catalyst loading. We aim to provide guidelines for the rational design and fabrication of highly efficient BiVO₄-based materials for water oxidation.

  2. Nanostructured bismuth vanadate-based materials for solar-energy-driven water oxidation: a review on recent progress

    NASA Astrophysics Data System (ADS)

    Huang, Zhen-Feng; Pan, Lun; Zou, Ji-Jun; Zhang, Xiangwen; Wang, Li

    2014-11-01

    Water oxidation is the key step for both photocatalytic water splitting and CO2 reduction, but its efficiency is very low compared with the photocatalytic reduction of water. Bismuth vanadate (BiVO4) is the most promising photocatalyst for water oxidation and has become a hot topic for current research. However, the efficiency achieved with this material to date is far away from the theoretical solar-to-hydrogen conversion efficiency, mainly due to the poor photo-induced electron transportation and the slow kinetics of oxygen evolution. Fortunately, great breakthroughs have been made in the past five years in both improving the efficiency and understanding the related mechanism. This review is aimed at summarizing the recent experimental and computational breakthroughs in single crystals modified by element doping, facet engineering, and morphology control, as well as macro/mesoporous structure construction, and composites fabricated by homo/hetero-junction construction and co-catalyst loading. We aim to provide guidelines for the rational design and fabrication of highly efficient BiVO4-based materials for water oxidation.

  3. Cost-effectiveness of anti-oxidant vitamins plus zinc treatment to prevent the progression of intermediate age-related macular degeneration. A Singapore perspective

    PubMed Central

    Saxena, Nakul; George, Pradeep Paul; Heng, Bee Hoon; Lim, Tock Han; Yong, Shao Onn

    2015-01-01

    Purpose: To determine if providing high dose anti-oxidant vitamins and zinc treatment age-related eye disease study (AREDS formulation) to patients with intermediate age-related macular degeneration (AMD) aged 40–79 years from Singapore is cost-effective in preventing progression to wet AMD. Methods: A hypothetical cohort of category 3 and 4 AMD patients from Singapore was followed for 5 calendar years to determine the number of patients who would progress to wet AMD given the following treatment scenarios: (a) AREDS formulation or placebo followed by ranibizumab (as needed) for wet AMD. (b) AREDS formulation or placebo followed by bevacizumab (monthly) for wet AMD. (c) AREDS formulation or placebo followed by aflibercept (VIEW I and II trial treatment regimen). Costs were estimated for the above scenarios from the providers’ perspective, and cost-effectiveness was measured by cost per disability-adjusted life year (DALY) averted with a disability weight of 0.22 for wet AMD. The costs were discounted at an annual rate of 3%. Results: Over 5400 patients could be prevented from progressing to wet AMD cumulatively if AREDS formulation were prescribed. AREDS formulation followed by ranibizumab was cost-effective compared to placebo-ranibizumab or placebo-aflibercept combinations (cost per DALY averted: SGD$23,662.3 and SGD$21,138.8, respectively). However, bevacizumab (monthly injections) alone was more cost-effective compared to AREDS formulation followed by bevacizumab. Conclusion: Prophylactic treatment with AREDS formulation for intermediate AMD patients followed by ranibizumab or for patients who progressed to wet AMD was found to be cost-effective. These findings have implications for intermediate AMD screening, treatment and healthcare planning in Singapore. PMID:26265643

  4. Cost-effectiveness of anti-oxidant vitamins plus zinc treatment to prevent the progression of intermediate age-related macular degeneration. A Singapore perspective.

    PubMed

    Saxena, Nakul; George, Pradeep Paul; Heng, Bee Hoon; Lim, Tock Han; Yong, Shao Onn

    2015-06-01

    To determine if providing high dose anti-oxidant vitamins and zinc treatment age-related eye disease study (AREDS formulation) to patients with intermediate age-related macular degeneration (AMD) aged 40-79 years from Singapore is cost-effective in preventing progression to wet AMD. A hypothetical cohort of category 3 and 4 AMD patients from Singapore was followed for 5 calendar years to determine the number of patients who would progress to wet AMD given the following treatment scenarios: (a) AREDS formulation or placebo followed by ranibizumab (as needed) for wet AMD. (b) AREDS formulation or placebo followed by bevacizumab (monthly) for wet AMD. (c) AREDS formulation or placebo followed by aflibercept (VIEW I and II trial treatment regimen). Costs were estimated for the above scenarios from the providers' perspective, and cost-effectiveness was measured by cost per disability-adjusted life year (DALY) averted with a disability weight of 0.22 for wet AMD. The costs were discounted at an annual rate of 3%. Over 5400 patients could be prevented from progressing to wet AMD cumulatively if AREDS formulation were prescribed. AREDS formulation followed by ranibizumab was cost-effective compared to placebo-ranibizumab or placebo-aflibercept combinations (cost per DALY averted: SGD$23,662.3 and SGD$21,138.8, respectively). However, bevacizumab (monthly injections) alone was more cost-effective compared to AREDS formulation followed by bevacizumab. Prophylactic treatment with AREDS formulation for intermediate AMD patients followed by ranibizumab or for patients who progressed to wet AMD was found to be cost-effective. These findings have implications for intermediate AMD screening, treatment and healthcare planning in Singapore.

  5. High concentrations of AGE-LDL and oxidized LDL in circulating immune complexes are associated with progression of retinopathy in type 1 diabetes.

    PubMed

    Lopes-Virella, Maria F; Baker, Nathaniel L; Hunt, Kelly J; Lyons, Timothy J; Jenkins, Alicia J; Virella, Gabriel

    2012-06-01

    To determine whether immunocomplexes (ICs) containing advanced glycation end product (AGE)-LDL (AGE-LDL) and oxidized LDL (oxLDL) contribute to the development of retinopathy over a 16-year period in subjects with type 1 diabetes. Levels of AGE-LDL and oxLDL in ICs were measured in 517 patients of the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) cohort. Retinopathy was assessed by stereoscopic fundus photography. Cox proportional hazards models were used to assess the effect of AGE-LDL-ICs and oxLDL-ICs on retinopathy progression. In unadjusted models, higher baseline levels of AGE-LDL-ICs and oxLDL-ICs significantly predicted progression of diabetic retinopathy outcomes. After adjustment by study-design variables (treatment group, retinopathy cohort, duration of type 1 diabetes, and baseline albumin excretion rate [AER], hemoglobin A(1c) (HbA(1c)), and Early Treatment Diabetic Retinopathy Study [ETDRS] score), one SD increase in IC levels was associated with 47% (hazard ratio [HR] 1.47 [95% CI 1.19-1.81]; AGE-LDL-IC) and 45% (1.45 [1.17-1.80]; oxLDL-IC) increased risk of developing proliferative diabetic retinopathy (PDR) and 37% (1.37 [1.12-1.66]; to both ICs) increased risk of progressing to severe nonproliferative retinopathy. Analyses were stratified by retinopathy cohort because results differed between primary and secondary cohorts. For AGE-LDL-ICs, HR for progression to PDR was 2.38 (95% CI 1.30-4.34) in the primary cohort and attenuated in the secondary cohort (1.29 [1.03-1.62]). Similar results were observed for oxLDL-ICs. Increased levels of AGE-LDL and oxLDL in ICs are associated with increased risk for progression to advanced retinopathy in patients with type 1 diabetes, indicating that the antibody response to modified LDL plays a significant role in retinopathy progression.

  6. Theory of the electronic and structural properties of solid state oxides. Progress report, [July 1, 1992--June 30, 1993

    SciTech Connect

    Chelikowsky, J.R.

    1993-01-01

    Some areas examined are: (1) The nature of the amorphization process of quartz under pressure, including the development of a new microscopic model for the amorphization process. (2) Elastic anomalies in high temperature forms of silica, including the discovery of a negative Poisson ratio in {alpha}-cristobalite. (3) The equation of states of crystalline silica polymorphs. (4) The behavior of the optical and electronic properties of quartz under pressure. (5) The optical and structural properties of titania and ruthenia. (6) The nature of transition metal dopants in titania. (7) New theoretical approaches for understanding covalent bonds in oxides and small semiconductor clusters.

  7. Factors affecting mutational specificity induced by ionizing radiation and oxidizing radicals. Technical progress report, February 1, 1992--October 15, 1992

    SciTech Connect

    Strauss, B.S.

    1992-01-01

    We propose to analyze the factors affecting the specificity of mutational change as induced by ionizing radiation and oxidizing radicals. We want to understand not only the rules that affect base substitution, but also the mechanism(s) by which additions and deletions are produced, since detections are a common consequence of radiation. We wish to carry out this analysis in an in vitro mutation system that permits us to analyze the role of base sequence, of polymerase and of mutagenic agent. Our system is designed to screen out most direct breaks as a cause of mutation and should indicate the changes resulting from base damage to the DNA.

  8. Acute exposure to prion infection induces transient oxidative stress progressing to be cumulatively deleterious with chronic propagation in vitro.

    PubMed

    Haigh, Cathryn L; McGlade, Amelia R; Lewis, Victoria; Masters, Colin L; Lawson, Victoria A; Collins, Steven J

    2011-08-01

    Neuronal loss is a pathological feature of prion diseases for which increased reactive oxygen species (ROS) and consequent oxidative stress is one proposed mechanism. The processes underlying ROS production in prion disease and the precise relationship to misfolding of the prion protein remain obscure. Using cell culture models of prion infection we found that cells demonstrate a rapid, prion protein (PrP) dependent, increase in intracellular ROS following exposure to infectious inoculum. ROS production correlated with internalisation and increased intracellular protease resistant PrP (PrP(Res)). The ROS increase was predominantly lysosomal in origin but not sustained, with cells adapting within 48 hours. Overall ROS levels remained normal in the chronically prion infected cell population; however a subpopulation characterised by loss of membrane phosphatidylserine asymmetry exhibited highly peroxidised intracellular aggregates that localised with PrP and intense caspase activation. These apoptotic cells showed increased ROS closely correlating with increased PrP(Res). Our findings demonstrate that a PrP-dependent, transient, increase in intracellular ROS is characteristic of acute cellular prion infection, while chronic phases of prion infection in vitro are associated with a significant subpopulation manifesting apoptosis accompanying heightened oxidative stress and increased PrP(Res) burden. Such observations strengthen the direct links between heightened ROS and ongoing prion propagation with eventual cellular demise.

  9. Genetics of bacteria that oxidize one-carbon compounds. Progress report, March 1, 1991--June 30, 1993

    SciTech Connect

    Hanson, R.S.

    1993-12-31

    In the past several years researchers have identified at least 20 genes whose products were required for the oxidation of methanol to formaldehyde in three different facultative methylotrophic bacteria. These genes include structural genes for a cytochrome c{sub L} (mox G) and is a specific electron acceptor for methanol dehydrogenase (MDH), and the two structural genes that encode the large subunit (mox F) and smaller subunit (mox I) of MDH. Other genes are required for the synthesis of the prosthetic group of MDH, Pyrroloquinoline quinone (PQQ), and proteins required for assembly of the active MDH in the periplasm. Three genes are believed to be required for incorporation of calcium into the MDH tetramer. The principal investigator`s group has studied the regulation of methanol oxidation in the pink-pigmented-facultative methylotroph Methylobacterium organophilum XX. The authors have mapped several genes and have sequenced the mox F gene and sequences upstream of mox F. The authors had tentatively identified several genes required for the transcription of the MDH structural genes in three methylotrophs. In the previous proposal, the P.I. proposed to establish an in-vitro transcription/translation system to study the function of the regulatory gene products. Further studies demonstrated that the regulation of transcription of these genes was far more complex than imagined at that time and the research plan was modified to determine the number and function of the regulatory genes using genetic approaches.

  10. Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report No. 6, July--September 1994

    SciTech Connect

    McCormick, R.L.

    1995-01-10

    This is the eighth quarterly technical progress report. During this quarter the project was initiated, after transfer via a novation agreement, at the Colorado School of Mines. Project initiation activities have included: set up of catalyst synthesis apparatus; training on x-ray diffraction and FTIR apparatus; set up of catalyst testing reactor; set up of reactor product analytical systems; and set up of method development for measuring catalyst acidity via FTIR. At the end of this quarter significant progress had been made towards completion of these initiation activities. Several catalyst syntheses have been performed and the catalysts characterized by x-ray diffraction and FTIR. The catalyst testing reactor system is operational. Reactor product analysis system is nearing completion. Initiation of this system was delayed by the unavailability of a Valco valve which has just recently arrived. Set up of the in-situ FTIR cell for catalyst acidity studies has begun. In this report the results of several catalyst syntheses are reported along with characterization results. In particular, impregnation of vanadyl pyrophosphate with potassim nitrate dramatically reduced the number of surface hydroxyl groups. Such groups may be important in the non-selective, total oxidation of hydrocarbons. Also, preliminary experimental results on FTIR spectra of adsorbed pyridine are presented. It is shown that pyridine adsorbed on the catalyst surface can be easily observed by the diffuse reflectance IR technique. We plan to apply this technique to measurement of the acid site strength of surfaces modified with promoters.

  11. DL-3-n-butylphthalide delays the onset and progression of diabetic cataract by inhibiting oxidative stress in rat diabetic model.

    PubMed

    Wang, Fuxu; Ma, Jia; Han, Fei; Guo, Xiujin; Meng, Li; Sun, Yufeng; Jin, Cheng; Duan, Huijun; Li, Hang; Peng, Ying

    2016-01-13

    DL-3-n-butylphthalide (NBP) is a therapeutic drug used for ischemic stroke treatment. Here, we investigated the impact of NBP on the development of rat diabetic cataract induced by intraperitoneal injection of streptozotocin (STZ). NBP was then administrated by oral gavage for nine weeks. Cataract development was monitored through ophthalmoscope inspections. The levels of blood glucose and serum reactive oxygen species (ROS), malondialdehyde (MDA) and 8-Hydroxydeovexyguanosine (8-OHdG) were measured. Total and soluble protein and oxidative stress parameters, such as 2, 4- dinitrophenylhydrazone (DNP), 4-hydroxynonenal (4-HNE) and MDA in the lenses were determined by Western blot and thiobarbituric acid analyses. The expressions of NF-E2-related factor 2 (Nrf2) and its downstream antioxidant enzymes, thioredoxin (TRX), Catalase and nuclear accumulation of Nrf2 were determined by Western blot and immunohistochemistry analyses. We showed that NBP treatment significantly improved the cataract scores, the levels of DNP, 4-HNE, and MDA in the lens compared to the non-treated groups. NBP also enhanced the expressions of Nrf2, TRX and catalase in the lens of diabetic rats. In addition, NBP treatment also decreased levels of blood glucose, serum MDA and 8-OHdG. These results suggested that NBP treatment significantly delayed the onset and progression of diabetic cataract by inhibiting the oxidative stresses.

  12. Recent Progress on Advanced Materials for Solid-Oxide Fuel Cells Operating Below 500 °C.

    PubMed

    Zhang, Yuan; Knibbe, Ruth; Sunarso, Jaka; Zhong, Yijun; Zhou, Wei; Shao, Zongping; Zhu, Zhonghua

    2017-06-19

    Solid-oxide fuel cells (SOFCs) are electricity generators that can convert the chemical energy in various fuels directly to the electric power with high efficiency. Recent advances in materials and related key components for SOFCs operating at ≈500 °C are summarized here, with a focus on the materials, structures, and techniques development for low-temperature SOFCs, including the analysis of most of the critical parameters affecting the electrochemical performance of the electrolyte, anode, and cathode. New strategies, such as thin-film deposition, exsolution of nanoparticles from perovskites, microwave plasma heating, and finger-like channeled electrodes, are discussed. These recent developments highlight the need for electrodes with higher activity and electrolytes with greater conductivity to generate a high electrochemical performance at lower temperatures. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. The research progress of Li-ion battery separators with inorganic oxide nanoparticles by electrospinning: A mini review

    NASA Astrophysics Data System (ADS)

    Chen, Hong-Li; Jiao, Xiao-Ning; Zhou, Jin-Tao

    2016-09-01

    The technology of Lithium-ion battery (LIB) separator has become more and more mature. But there are still many problems that needed to be resolved. For example, its mechanical strength is low relatively, thermal stability is bad and the porosity and electrochemical performance are imperfect. This paper introduces modification of electrospinning LIB separator from the way of adding nanoparticles, including SiO2, TiO2, Al2O3 and copper titanate oxide, etc. And addition methods include dissolving in dispersant, dissolving in polymer solution, coating and in situ method. The modified membranes possess higher ionic conductivity which can reach to the level of 10-3s/cm.

  14. [Fundamental studies in oxidation-reduction in relation to water photolysis]. Progress report, November 1, 1990--October 25, 1991

    SciTech Connect

    Hurst, J.K.

    1991-12-31

    Our research has been directed at understanding three elementary processes that are central to developing membrane-based integrated chemical systems for water photolysis. These are: (1) the role of interfaces in charge separation/recombination reactions, (2) pathways for transmembrane charge separation, and (3) mechanisms of water oxidation catalyzed by transition metal coordination complexes. Historically, the chemical dynamics of each of these processes has been poorly understood, with numerous unresolved issues and conflicting viewpoints appearing in the literature. Our experimental systems comprise primarily unilamellar vesicles that have been doped with amphiphilic viologens which function as transmembrane charge relays. These systems are experimentally highly tractable and versatile, are conceptually simple, and have been widely used in a variety of organized microphase media and prototypic devices. As such, they are ideal for identifying basic principles governing reactivity.

  15. Evaluation of Systemic Antioxidant Level and Oxidative Stress in Relation to Lifestyle and Disease Progression in Asthmatic Patients

    PubMed Central

    Saini, Manisha

    2016-01-01

    Summary Background Asthma is a chronic disorder of the airways. Oxidative stress is an important part of asthma pathogenesis. It plays a crucial role in exacerbating the disease, as well as an important consequence of airways inflammation. Aim The present study was undertaken to investigate the lipid peroxidation and catalase activity in serum and antioxidant level in plasma of asthmatic patients and their association with lifestyle and severity of the disease. Methods A total of 210 subjects, 120 asthmatics and 90 healthy controls matched in respect to age, sex, lifestyle and socioeconomic status, were chosen randomly for the present study. The samples were analyzed for MDA concentration and catalase activity in serum and ferric reducing ability of plasma (FRAP). Statistical analysis was done using unpaired Student’s t-test, ANOVA with Duncan post hoc test and Pearson coefficient of correlation. Results The serum MDA was found to be significantly higher in the asthmatics as compared to healthy individuals (p<0.01) while catalase activity in serum and antioxidant level of the plasma were markedly lower in the asthmatics as compared to healthy individuals (p<0.01). A significant difference was observed in serum MDA, catalase activity and plasma antioxidant level among the patients in relation to the severity of disease. There was a marked increase in the serum MDA in the patients with longer duration of the disease (p<0.05). Conclusions The oxidant–antioxidant imbalance occurs in asthma leading to oxidative stress and is an important part of the asthma pathogenesis. PMID:28356865

  16. Telmisartan reduces progressive oxidative stress and phosphorylated α-synuclein accumulation in stroke-resistant spontaneously hypertensive rats after transient middle cerebral artery occlusion.

    PubMed

    Sato, Kota; Yamashita, Toru; Kurata, Tomoko; Lukic, Violeta; Fukui, Yusuke; Hishikawa, Nozomi; Deguchi, Kentaro; Abe, Koji

    2014-07-01

    Telmisartan is an angiotensin receptor blocker with high lipid solubility, also called metabosartan, which exerts a special protective effect on both acute brain damage and chronic neurodegeneration. We examined the effects of telmisartan on oxidative stress by advanced glycation end product (AGE) and 4-hydroxynonenal (4-HNE) assays and the accumulation of phosphorylated α-synuclein (pSyn) in the brain of stroke-resistant spontaneously hypertensive rats (SHR-SR). At the age of 12 weeks, SHR-SR received transient middle cerebral artery occlusion (tMCAO) for 90 minutes and were divided into the following 3 groups: the vehicle group, the low-dose telmisartan group (.3 mg/kg/day), and the high-dose telmisartan group (3 mg/kg/day, postoperatively). Immunohistologic analysis was performed when rats were 6, 12, and 18 months old. AGE, 4-HNE, and pSyn-positive cells (per square millimeter) increased with age in the cerebral cortex and hippocampus of the vehicle group, in the low-dose telmisartan group, these parameters decreased without lowering blood pressure (BP), and in the high-dose telmisartan group, these parameters increased with lowering BP. The present study suggests that a persistent hypertension after tMCAO caused a progressive oxidative stress with the abnormal accumulation of pSyn, and that telmisartan reduced oxidative stress and the accumulation of pSyn without lowering BP (low dose) or improved these conditions with a reduction in BP (high dose) via its pleiotropic effects through a potential peroxisome proliferator-activated receptor gamma stimulation in the brain of SHR-SR. Copyright © 2014. Published by Elsevier Inc.

  17. Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report 3, April--June 1993

    SciTech Connect

    McCormick, R.L.; Jha, M.C.; Streuber, R.D.

    1993-08-20

    This document is the third quarterly technical progress report under Contract No. AC22-92PC92110, ``Development of Vanadium-Phosphate Catalysts for Methanol Production by Selective Oxidation of Methane.`` During this quarter, we have continued to develop methods for catalyst activation by investigating activation in wet gas environments. This procedure leads to the formation of highly crystalline (VO){sub 2}P{sub 2}O{sub 7}, while activation under identical conditions, but with no moisture, leads to a poorly crystalline sample. Published data indicate that the highly crystalline form is representative of commercial butane oxidation catalysts. The main focus of our work during this quarter has been in the area of catalyst testing in the microreactor system. In order to confirm that our microreactor system was providing reliable data, we tested a V{sub 2}O{sub 5}/SiO{sub 2} catalyst at atmospheric pressure and temperatures from 500 to 600{degree}C using 90 to 95 percent CH{sub 4}/O{sub 2}. Several studies of methane oxidation using this catalyst have been published with reasonably good agreement between different research groups. We were not able to reproduce the literature data using steel reactors. However, when the steel reactor was lined with quartz and the postcatalyst reactor volume was minimized by packing with quartz chips, we obtained results which agree closely with those previously published. Using the same quartz reactor and test conditions, we also tested a highly crystalline (wet activated) VPO catalyst.

  18. Recent progress in oxide scintillation crystals development by low-thermal gradient Czochralski technique for particle physics experiments

    NASA Astrophysics Data System (ADS)

    Shlegel, V. N.; Borovlev, Yu. A.; Grigoriev, D. N.; Grigorieva, V. D.; Danevich, F. A.; Ivannikova, N. V.; Postupaeva, A. G.; Vasiliev, Ya. V.

    2017-08-01

    Modern particle physics experiments call for high performance scintillation detectors with unique properties: radiation-resistant in high energy and astrophysics, highly radiopure, containing certain elements or enriched isotopes in astroparticle physics. The low-thermal gradient Czochralski (LTG CZ) crystal growth technique provides excellent quality large volume radiopure crystal scintillators. Absence of thermoelastic stress in the crystal and overheating of the melt in the LTG CZ method is particularly significant in production of crystalline materials with strong thermal anisotropic properties and low mechanical strength, with a very high yield of crystalline boules and low losses of initial charge, crucially important in production of crystal scintillators from enriched isotopes for double beta decay experiments. Here we discuss progress in development of the well known scintillators (Bi4Ge3O12 (BGO), CdWO4, ZnWO4, CaMoO4, PbMoO4), as well as R&D of new materials (ZnMoO4, Li2MoO4, Na2Mo2O7) for the next generation experiments in particle physics.

  19. Nucleation, Growth, Annealing, and Coagulation of Refractory Oxides and Metals: Recent Experimental Progress and Applications to Astrophysical Systems

    NASA Technical Reports Server (NTRS)

    Nuth, J. A.; Rietmeijer, F. J. M.; Hallenbeck, S. L.; Withey, P. A.

    1999-01-01

    Starting with cooling, refractory vapors diluted in significant quantities of H and He there are four processes that most natural systems will undergo: nucleation, growth, annealing, and coagulation. Nucleation is the processes by which the first stable refractory nuclei form in the vapor. These are the seeds onto which the remaining vapors will condense during the growth stage. Solids of any composition will try to arrange themselves into the least energetic configuration, provided that there is sufficient energy available to support such processes as diffusion and the breaking of chemical bonds. There is a significant activation energy associated with the annealing process in refractory solids due to the relatively high energy of the chemical bonds in solids. The grains formed in most cosmochemical systems are extremely small and often tightly coupled to the gas. Because of their small physical cross sections coagulation may be a very slow process unless there is another driving force involved in addition to normal Brownian motion. In what follows we will briefly cover each of these four stages for refractory oxide and metal grains, although in inverse order.

  20. TOPICAL REVIEW: Zinc oxide nanorod based photonic devices: recent progress in growth, light emitting diodes and lasers

    NASA Astrophysics Data System (ADS)

    Willander, M.; Nur, O.; Zhao, Q. X.; Yang, L. L.; Lorenz, M.; Cao, B. Q.; Zúñiga Pérez, J.; Czekalla, C.; Zimmermann, G.; Grundmann, M.; Bakin, A.; Behrends, A.; Al-Suleiman, M.; El-Shaer, A.; Che Mofor, A.; Postels, B.; Waag, A.; Boukos, N.; Travlos, A.; Kwack, H. S.; Guinard, J.; LeSi Dang, D.

    2009-08-01

    Zinc oxide (ZnO), with its excellent luminescent properties and the ease of growth of its nanostructures, holds promise for the development of photonic devices. The recent advances in growth of ZnO nanorods are discussed. Results from both low temperature and high temperature growth approaches are presented. The techniques which are presented include metal-organic chemical vapour deposition (MOCVD), vapour phase epitaxy (VPE), pulse laser deposition (PLD), vapour-liquid-solid (VLS), aqueous chemical growth (ACG) and finally the electrodeposition technique as an example of a selective growth approach. Results from structural as well as optical properties of a variety of ZnO nanorods are shown and analysed using different techniques, including high resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM), photoluminescence (PL) and cathodoluminescence (CL), for both room temperature and for low temperature performance. These results indicate that the grown ZnO nanorods possess reproducible and interesting optical properties. Results on obtaining p-type doping in ZnO micro- and nanorods are also demonstrated using PLD. Three independent indications were found for p-type conducting, phosphorus-doped ZnO nanorods: first, acceptor-related CL peaks, second, opposite transfer characteristics of back-gate field effect transistors using undoped and phosphorus doped wire channels, and finally, rectifying I-V characteristics of ZnO:P nanowire/ZnO:Ga p-n junctions. Then light emitting diodes (LEDs) based on n-ZnO nanorods combined with different technologies (hybrid technologies) are suggested and the recent electrical, as well as electro-optical, characteristics of these LEDs are shown and discussed. The hybrid LEDs reviewed and discussed here are mainly presented for two groups: those based on n-ZnO nanorods and p-type crystalline substrates, and those based on n-ZnO nanorods and p-type amorphous substrates. Promising electroluminescence

  1. Progression of genotype-specific oral cancer leads to senescence of cancer-associated fibroblasts and is mediated by oxidative stress and TGF-β.

    PubMed

    Hassona, Yazan; Cirillo, Nicola; Lim, Kue Peng; Herman, Andrew; Mellone, Max; Thomas, Gareth J; Pitiyage, Gayani N; Parkinson, E Ken; Prime, Stephen S

    2013-06-01

    Keratinocyte senescence acts as a barrier to tumor progression but appears to be lost in late pre-malignancy to yield genetically unstable oral squamous cell carcinomas (GU-OSCC); a subset of OSCC possessing wild-type p53 and are genetically stable (GS-OSCC). In this study, fibroblasts from GU-OSCC were senescent relative to fibroblasts from GS-OSCC, epithelial dysplastic tissues or normal oral mucosa, as demonstrated by increased senescence-associated β-galactosidase (SA β-Gal) activity and overexpression of p16(INK4A). Keratinocytes from GU-OSCC produced high levels of reactive oxygen species (ROS) and this was associated with an increase in the production of transforming growth factor-β1 (TGF-β1) and TGF-β2 in stromal fibroblasts. Treatment of normal fibroblasts with keratinocyte conditioned media (CM) from GU-OSCC, but not GS-OSCC or dysplastic keratinocytes with dysfunctional p53, induced fibroblast senescence. This phenomenon was inhibited by antioxidants and anti-TGF-β antibodies. Fibroblast activation by TGF-β1 preceded cellular senescence and was associated with increased ROS levels; antioxidants inhibited this reaction. Senescent fibroblasts derived from GU-OSCC or normal fibroblasts treated with CM from GU-OSCC or hydrogen peroxide, but not non-senescent fibroblasts derived from GS-OSCC, promoted invasion of keratinocytes in vitro. Epithelial invasion was stimulated by fibroblast activation and amplified further by fibroblast senescence. The data demonstrate that malignant keratinocytes from GU-OSCC, but not their pre-malignant counterparts, produce high levels of ROS, which, in turn, increase TGF-β1 expression and induce fibroblast activation and senescence in a p5-independent manner. Fibroblasts from GU-OSCC were particularly susceptible to oxidative DNA damage because of high levels of ROS production, downregulation of antioxidant genes and upregulation of pro-oxidant genes. The results demonstrate the functional diversity of cancer

  2. IFN-γ and TNF-α are involved during Alzheimer disease progression and correlate with nitric oxide production: a study in Algerian patients.

    PubMed

    Belkhelfa, Mourad; Rafa, Hayet; Medjeber, Oussama; Arroul-Lammali, Amina; Behairi, Nassima; Abada-Bendib, Myriam; Makrelouf, Mohamed; Belarbi, Soreya; Masmoudi, Ahmed Nacer; Tazir, Meriem; Touil-Boukoffa, Chafia

    2014-11-01

    Alzheimer's disease (AD) is a neurodegenerative disease leading to a progressive and irreversible loss of mental functions. It is characterized by 3 stages according to the evolution and the severity of the symptoms. This disease is associated with an immune disorder, which appears with significant rise in the inflammatory cytokines and increased production of free radicals such as nitric oxide (NO). Our study aims to investigate interferon (IFN)-γ and tumor necrosis factor-α (TNF-α) involvement in NO production, in vivo and ex vivo, in peripheral blood mononuclear cells from Algerian patients (n=25), according to the different stages of the disease (mild Alzheimer's, moderate Alzheimer's, and severe Alzheimer's) in comparison to mild cognitive impairment (MCI) patients. Interestingly, we observed that in vivo IFN-γ and TNF-α levels assessed in patients with AD in mild and severe stages, respectively, are higher than those observed in patients with moderate stage and MCI. Our in vivo and ex vivo results show that NO production is related to the increased levels of IFN-γ and TNF-α, in mild and severe stages of AD. Remarkably, significant IFN-γ level is only detected in mild stage of AD. Our study suggests that NO production is IFN-γ dependent both in MCI and mild Alzheimer's patients. Further, high levels of NO are associated with an elevation of TNF-α levels in severe stage of AD. Collectively, our data indicate that the proinflammatory cytokine production seems, in part, to be involved in neurological deleterious effects observed during the development of AD through NO pathway.

  3. Oxidative/Nitrative Stress and Inflammation Drive Progression of Doxorubicin-Induced Renal Fibrosis in Rats as Revealed by Comparing a Normal and a Fibrosis-Resistant Rat Strain.

    PubMed

    Szalay, Csaba Imre; Erdélyi, Katalin; Kökény, Gábor; Lajtár, Enikő; Godó, Mária; Révész, Csaba; Kaucsár, Tamás; Kiss, Norbert; Sárközy, Márta; Csont, Tamás; Krenács, Tibor; Szénási, Gábor; Pacher, Pál; Hamar, Péter

    2015-01-01

    Chronic renal fibrosis is the final common pathway of end stage renal disease caused by glomerular or tubular pathologies. Genetic background has a strong influence on the progression of chronic renal fibrosis. We recently found that Rowett black hooded rats were resistant to renal fibrosis. We aimed to investigate the role of sustained inflammation and oxidative/nitrative stress in renal fibrosis progression using this new model. Our previous data suggested the involvement of podocytes, thus we investigated renal fibrosis initiated by doxorubicin-induced (5 mg/kg) podocyte damage. Doxorubicin induced progressive glomerular sclerosis followed by increasing proteinuria and reduced bodyweight gain in fibrosis-sensitive, Charles Dawley rats during an 8-week long observation period. In comparison, the fibrosis-resistant, Rowett black hooded rats had longer survival, milder proteinuria and reduced tubular damage as assessed by neutrophil gelatinase-associated lipocalin (NGAL) excretion, reduced loss of the slit diaphragm protein, nephrin, less glomerulosclerosis, tubulointerstitial fibrosis and matrix deposition assessed by periodic acid-Schiff, Picro-Sirius-red staining and fibronectin immunostaining. Less fibrosis was associated with reduced profibrotic transforming growth factor-beta, (TGF-β1) connective tissue growth factor (CTGF), and collagen type I alpha 1 (COL-1a1) mRNA levels. Milder inflammation demonstrated by histology was confirmed by less monocyte chemotactic protein 1 (MCP-1) mRNA. As a consequence of less inflammation, less oxidative and nitrative stress was obvious by less neutrophil cytosolic factor 1 (p47phox) and NADPH oxidase-2 (p91phox) mRNA. Reduced oxidative enzyme expression was accompanied by less lipid peroxidation as demonstrated by 4-hydroxynonenal (HNE) and less protein nitrosylation demonstrated by nitrotyrosine (NT) immunohistochemistry and quantified by Western blot. Our results demonstrate that mediators of fibrosis, inflammation and

  4. Studies of incipient oxidation of coal-pyrite for improved pyrite rejection. Third quarterly technical progress report, April 1, 1993--June 30, 1993

    SciTech Connect

    Yoon, R.H.; Richardson, P.E.

    1993-11-01

    The initial stages of pyrite oxidation are being studied to develop methods to control pyrite surface chemistry and foster pyrite rejection in coal flotation circuits. A major objective of this work is to study incipient oxidation, which is accomplished by fracturing pyrite electrodes in an electrochemical cell. It has been shown that by holding the potential at various values during fracture and measuring the current passed at fracture, pyrite oxidation or reduction can be precisely controlled. The oxidation and reduction products on pyrite following fracture are being studied by a combination of voltammetry, photocurrent, and impedance spectroscopy techniques. During this report period, major effort was devoted to characterizing the surfaces by impedance spectroscopy.

  5. Studies of incipient oxidation of coal-pyrite for improved pyrite rejection. Technical Progress report, January 1, 1993--March 31, 1993

    SciTech Connect

    Yoon, R.H.; Richardson, P.E.

    1993-06-01

    To foster the development of advanced coal cleaning technologies, the initial stages of pyrite oxidation are being studied. The voltammetry behavior of polished pyrite at moderate overpotentials is known to be dominated by iron oxides and hydroxides that are generated during the polishing process. The present work is being done on pyrite surfaces that are freshly fractured in an electrolyte solution. The creation of fresh surfaces by in situ fracture allows studies of the initial oxidation of pyrite itself, without complications from overlayers of iron oxides and hydroxides produced by polishing. Chronoamperometry immediately after fracture and subsequent cyclic voltammetry is being used to elucidate the initial oxidation reaction that produces hydrophobic sulfur species on pyrite.

  6. An oral adsorbent, AST-120 protects against the progression of oxidative stress by reducing the accumulation of indoxyl sulfate in the systemic circulation in renal failure.

    PubMed

    Shimoishi, Kazuki; Anraku, Makoto; Kitamura, Kenichiro; Tasaki, Yuka; Taguchi, Kazuaki; Hashimoto, Mitsuru; Fukunaga, Eiko; Maruyama, Toru; Otagiri, Masaki

    2007-07-01

    The effect of AST-120, an oral adsorbent, on oxidative stress in the systemic circulation in chronic renal failure (CRF) was examined and the potential role of indoxyl sulfate (IS), an uremic toxin adsorbed by AST-120, in inducing the formation of reactive oxygen species (ROS) in the vascular system was studied, in vitro and in vivo. The level of oxidized albumin, a marker for oxidative stress in the systemic circulation was determined by HPLC, as previously reported. The mRNA levels of TGF-beta (1) and Oat1 were measured by quantitative RT-PCR. The IS induced ROS generation in cultured human umbilical vein endothelial cells (HUVECs) was estimated using a fluorescence microplate reader. An increase in the ratio of oxidized to unoxidized albumin was determined using 5/6 nephrectomized rats (CRF rats) compared to a control group. The ratio was significantly reduced in the group that received AST-120 of 4 weeks, suggesting that AST-120 inhibits oxidative stress in CRF. An anti-oxidative effect of AST-120 was also observed in CRF rats with a similar renal function. The ratio of oxidized albumin was correlated with serum IS levels in vivo. The same relationship was also observed in CRF rats with the continued administration of IS. In addition, IS dramatically increased the generation of ROS in both a dose- and time- dependent manner in HUVEC, suggesting that accumulated IS may play an important role in enhancing intravascular oxidative stress. We propose that AST-120 reduces IS concentrations in the blood that induces ROS production in endothelial cells, thereby inhibiting the subsequent occurrence of oxidative stress in the systemic circulation in renal failure.

  7. Spent-fuel special-studies progress report: probable mechanisms for oxidation and dissolution of single-crystal UO/sub 2/ surfaces

    SciTech Connect

    Wang, R.

    1981-03-01

    Due to the complexity of the structural, microstructural and compositional characteristics of spent fuel, basic leaching and dissolution mechanisms were studied with UO/sub 2/ matrix material, specifically with single-crystal UO/sub 2/, to isolate individual contributory factors. The effects of oxidation and oxidation-dissolution were investigated in different oxidation conditions, such as in air, oxygenated solutions and deionized water containing H/sub 2/O/sub 2/. In addition, the effects of temperature on dissolution of UO/sub 2/ were studied in autoclaves at 75 and 150/sup 0/C. Also, oxidation and dissolution measurements were investigated via electrochemical methods to determine if those techniques could be applied to the characterization of leaching and dissolution of spent fuel in a hot cell. Finally, the effects of radiation were explored since the radiolysis of water may create a localized oxidizing condition at or near the spent fuel-solution interface, even in neutral or reducing conditions as commonly found in deep geological environments. The oxidation and oxidation-dissolution mechanisms for UO/sub 2/ are proposed as follows: The UO/sub 2/ surface is first oxidized in solution to form a UO/sub 2+x/ surface layer several angstroms thick. This oxidized surface has a high dissolution rate since the UO/sub 2+x/ reacts with the dissolved O/sub 2/, or H/sub 2/O/sub 2/, to form uranyl complex ions in a U(VI) state. As the uranyl ions exceed the solubility limits in solution, they become hydrolyzed to form solid deposits and suspended particles of UO/sub 3/ hydrates. The thickness and porosity of the deposited UO/sub 3/ hydrate surface-film is dependent on temperature, pH and deposition time. A long-term dissolution rate is then determined by the nature of the surface film, such as porosity, solubility and mechanical properties.

  8. Recent progress in development of infrared laser based instruments for real-time ambient measurements of isotopologues of carbon dioxide, water, methane, nitrous oxide and carbon monoxide

    NASA Astrophysics Data System (ADS)

    Nelson, David; McManus, Barry; Shorter, Joanne; Zahniser, Mark; Ono, Shuhei

    2014-05-01

    The capacity for real time precise in situ measurements of isotopic ratios of a variety of trace gases at ambient concentrations continues to create new opportunities for the study of the exchanges and fluxes of gases in the environment. Aerodyne Research has made rapid progress in laser based instruments since our introduction in 2007 of the first truly field worthy instrument for real time measurements of isotopologues of carbon dioxide. We have focused on two instrument design platforms, with either one or two lasers. Absorption cells with more than 200 meters path length allow precise measurements of trace gases with low ambient concentrations. Most of our systems employ mid infrared quantum cascade lasers. However, recently available 3 micron antimonide based diode lasers are also proving useful for isotopic measurements. By substituting different lasers and detectors, we can simultaneously measure the isotopic composition of a variety of gases, including: H2O, CO2, CH4, N2O and CO. Our newest instrument for true simultaneous measurement of isotopologues of CO2 (12CO2, 13CO2, 12C18O16O) has (1 s) precision better than 0.1 per mil for both ratios. The availability of 10 Hz measurements allows measurement of isotopic fluxes via eddy correlation. The single laser instrument fits in a 19 inch rack and is only 25 cm tall. A two laser instrument is larger, but with that instrument we can also measure clumped isotopes of CO2, with 1 second precisions of: 2.3 per mil for 13C18O16O, and 6.7 per mil for 13C17O16O. The sample size for such a measurement corresponds to 0.2 micromole of pure CO2. Another variation on the two laser instrument simultaneously measures isotopologues of CO2 (12CO2, 13CO2, 12C18O16O) and H2O (H216O, H218O, HD16O). Preliminary results for water ratio precisions (in 1s) are 0.1 per mil for H218O and 0.3 per mil for HD16O, simultaneous (1 s) precisions for isotopologues of CO2 of ~0.1 per mil. Methane, nitrous oxide and carbon monoxide have such

  9. Neutronics Benchmarks for the Utilization of Mixed-Oxide Fuel: Joint U.S./Russian Progress Report for Fiscal Year 1997 Volume 2-Calculations Performed in the United States

    SciTech Connect

    Primm III, RT

    2002-05-29

    This volume of the progress report provides documentation of reactor physics and criticality safety studies conducted in the US during fiscal year 1997 and sponsored by the Fissile Materials Disposition Program of the US Department of Energy. Descriptions of computational and experimental benchmarks for the verification and validation of computer programs for neutron physics analyses are included. All benchmarks include either plutonium, uranium, or mixed uranium and plutonium fuels. Calculated physics parameters are reported for all of the computational benchmarks and for those experimental benchmarks that the US and Russia mutually agreed in November 1996 were applicable to mixed-oxide fuel cycles for light-water reactors.

  10. Studies of incipient oxidation of pyrite for improved rejection. Technical progress report for the fourth quarter, July 1, 1993--September 30, 1993

    SciTech Connect

    Yoon, R.H.; Richardson, P.E.

    1993-10-01

    One major objective of this work is to determine the Eh-pH conditions under which pyrite is stable and then to determine the mechanism of the initial stages of pyrite oxidation. It is known that moderate oxidation of pyrite produces a hydrophobic surface product. This hydrophobic product makes it extremely difficult to depress pyrite in coal flotation circuits. The eventual objective of this work is to prevent pyrite oxidation in order to better depress pyrite in coal flotation circuits. In this work clean, unoxidized pyrite surfaces are being produced by fracturing pyrite electrodes in an electrochemical cell. It has been shown that by holding the potential at different values during fracture and measuring the current passed at fracture, pyrite oxidation or reduction can be precisely controlled, or prevented. In the previous quarterly report, pyrite oxidation in pH 9.2 buffer solution was discussed. During this report period, the initial stages of pyrite oxidation in pH 4.6 buffer solution were studied, and the results compared with those in pH 9.2 solution. The effect of anodic and cathodic potential limits on the subsequent photocurrent and voltammetry behavior of freshly-fractured pyrite electrodes was also determined.

  11. The contribution of reactive oxygen species and p38 mitogen-activated protein kinase to myofilament oxidation and progression of heart failure in rabbits.

    PubMed

    Heusch, P; Canton, M; Aker, S; van de Sand, A; Konietzka, I; Rassaf, T; Menazza, S; Brodde, O E; Di Lisa, F; Heusch, G; Schulz, R

    2010-07-01

    The formation of reactive oxygen species (ROS) is increased in heart failure (HF). However, the causal and mechanistic relationship of ROS formation with contractile dysfunction is not clear in detail. Therefore, ROS formation, myofibrillar protein oxidation and p38 MAP kinase activation were related to contractile function in failing rabbit hearts. Three weeks of rapid left ventricular (LV) pacing reduced LV shortening fraction (SF, echocardiography) from 32 +/- 1% to 13 +/- 1%. ROS formation, as assessed by dihydroethidine staining, increased by 36 +/- 8% and was associated with increased tropomyosin oxidation, as reflected by dimer formation (dimer to monomer ratio increased 2.28 +/- 0.66-fold in HF vs. sham, P < 0.05). Apoptosis (TdT-mediated dUTP nick end labelling staining) increased more than 12-fold after 3 weeks of pacing when a significant increase in the phosphorylation of p38 MAP kinase and HSP27 was detected (Western blotting). Vitamins C and E abolished the increases in ROS formation and tropomyosin oxidation along with an improvement of LVSF (19 +/- 1%, P < 0.05 vs. untreated HF) and prevention of apoptosis, but without modifying p38 MAP kinase activation. Inhibition of p38 MAP kinase by SB281832 counteracted ROS formation, tropomyosin oxidation and contractile failure, without affecting apoptosis. Thus, p38 MAP kinase activation appears to be upstream rather than downstream of ROS, which impacts on LV function through myofibrillar oxidation. p38 MAP kinase inhibition is a potential target to prevent or treat HF.

  12. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report, December 1, 1993--May 31, 1994

    SciTech Connect

    Doyle, F.M.

    1994-08-01

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. The results will provide fundamental insight into oxidation, in term of the bulk and surface chemistry, the microstructure, and the semiconductor properties of the pyrite. During the fourteenth and fifteenth quarters, flotation tests were done on Upper Freeport coal from the Troutvill {number_sign}2 Mine, Clearfield County, Pennsylvania and on coal samples from the Pennsylvania State Coal Bank. The influence of electrode potential on the surface properties of coal pyrite was tested using contact angle measurements on polarized Pittsburgh coal pyrite electrode.

  13. Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Quarterly technical progress report, December 1, 1993--May 31, 1994

    SciTech Connect

    Doyle, F.M.

    1996-01-01

    The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. The results will provide fundamental insight into oxidation, in term of the bulk and surface chemistry, the microstructure, and the semiconductor properties of the pyrite. During the fourteenth and fifteenth quarters, flotation tests were done on Upper Freeport coal from the Troutville No. 2 Mine, Clearfield County, Pennsylvania and on coal samples from the Pennsylvania State Coal Bank. The influence of electrode potential on the surface properties of coal pyrite was tested using contact angle measurements on polarized Pittsburgh coal pyrite electrode.

  14. Resveratrol increases nitric oxide synthase, induces accumulation of p53 and p21(WAF1/CIP1), and suppresses cultured bovine pulmonary artery endothelial cell proliferation by perturbing progression through S and G2.

    PubMed

    Hsieh, T C; Juan, G; Darzynkiewicz, Z; Wu, J M

    1999-06-01

    Epidemiological studies have shown that the regular consumption of red wine may in part account for the apparent compatibility of a high fat diet with a low incidence of coronary atherosclerosis. This phenomenon, commonly referred to as the French paradox, may be associated with red wine constituents that exhibit tumor-preventive properties as well as inhibit reactions that increase the risk of coronary heart disease. Here we show that resveratrol, a polyphenol in red wine, induces nitric oxide synthase, the enzyme responsible for the biosynthesis of NO, in cultured pulmonary artery endothelial cells, suggesting that resveratrol could afford cardioprotection by affecting the expression of nitric oxide synthase. We also show that resveratrol inhibits the proliferation of pulmonary artery endothelial cells, which, based on flow cytometric analysis, correlates with the suppression of cell progression through S and G2 phases of the cell cycle. Western blot analysis and immunocytochemical protein detection combined with multiparameter flow cytometry further demonstrate that the perturbed progression through S and G2 phases is accompanied by an increase in the expression of tumor suppressor gene protein p53 and elevation of the level of cyclin-dependent kinase inhibitor p21(WAF1/CIP1). All of the observed effects of resveratrol, including induction of apoptosis at its higher concentration, are also compatible with its putative chemopreventive and/or antitumor activity.

  15. Low density lipoprotein is protected from oxidation and the progression of atherosclerosis is slowed in cholesterol-fed rabbits by the antioxidant N,N'-diphenyl-phenylenediamine.

    PubMed Central

    Sparrow, C P; Doebber, T W; Olszewski, J; Wu, M S; Ventre, J; Stevens, K A; Chao, Y S

    1992-01-01

    The oxidative modification of low density lipoprotein (LDL) may play an important role in atherosclerosis. We found that the antioxidant N,N'-diphenyl-1,4-phenylenediamine (DPPD) inhibits in vitro LDL oxidation at concentrations much lower than other reported antioxidants. To test whether DPPD could prevent atherosclerosis, New Zealand White rabbits were fed either a diet containing 0.5% cholesterol and 10% corn oil (control group) or the same diet also containing 1% DPPD (DPPD-fed group) for 10 wk. Plasma total cholesterol levels were not different between the two groups, but DPPD feeding increased the levels of triglyceride (73%, P = 0.007) and HDL cholesterol (26%, P = 0.045). Lipoproteins from DPPD-fed rabbits contained DPPD and were much more resistant to oxidation than control lipoproteins. After 10 wk, the DPPD-fed animals had less severe atherosclerosis than did the control animals: thoracic aorta lesion area was decreased by 71% (P = 0.0007), and aortic cholesterol content was decreased by 51% (P = 0.007). Although DPPD cannot be given to humans because it is a mutagen, our results indicate that orally active antioxidants can have antiatherosclerotic activity. This strongly supports the theory that oxidized LDL plays an important role in the pathogenesis of atherosclerosis. PMID:1601995

  16. A silica/fly ash-based technology for controlling pyrite oxidation. Semi-annual technical progress report, September 1, 1995--February 29, 1996

    SciTech Connect

    Evangelou, V.P.

    1996-03-28

    The overall objective is to develop methodologies by which sodium metasilicate or fly ash may produce an effective coating on pyrite surfaces for inhibiting pyrite oxidation. Accomplishments are described for the following tasks: Pyrite surface reactivity; Micro column leaching experiments; and Large column leaching experiments.

  17. Studies of incipient oxidation of coal-pyrite for improved pyrite rejection. First quarterly technical progress report, October 1, 1992--December 31, 1992

    SciTech Connect

    Yoon, R.H.; Richardson, P.E.

    1992-12-31

    In order to foster the development of advanced coal cleaning technologies fundamental studies.of the initial stages of pyrite oxidation have been.initiated. This work is being done on pyrite surfaces that are freshly fractured in an electrolyte solution. This procedure produces surfaces that are initially unoxidized, allowing the subsequent oxidation processes to be studied in detail. It is shown that freshly fractured pyrite electrodes instantaneously (at fracture) assume a rest potential several hundred millivolts more negative than the usual open-circuit potential. A finite, anodic photocurrent, is also observed on the fractured electrodes. Following cleavage, the rest potential increases, indicating an oxidation reaction occurring on the electrodes. The photocurrent is relatively insensitive to this oxidation process, and to moderate anodic and cathodic polarization. However, strong cathodic polarization to about -0.76 V (SHE) at pH 9.2 causes the photocurrent to decrease to zero. No reversal in the sign of the photocurrent is observed and it is believed that the flat band potential occurs near -0.76 V, i.e., where the photocurrent goes to zero. Voltammetry indicates that pyrite also undergoes cathodic decomposition at -0.76 V. This establishes that pyrite must be cathodically decomposed to reach the flat band potential.

  18. Study of the genetics and regulation of methane oxidation. Progress report, second year and a half, August 1, 1981-January 31, 1983

    SciTech Connect

    Not Available

    1983-01-01

    The purpose is to develop mutagenesis, gene transfer and cloning systems in methanotrophic bacteria, and use these techniques to study the methane oxidation genes. Although we have been successful in the first part of these objectives, the study of methane oxidation genes has proven difficult. Problems arose due to the discovery that the culture, Methylobacterium ethanolicum, is in reality a stable coculture between two methylotrophs. These partners are Methylocystis POC, an obligate methanotroph and Xanthobacter H4.14, and autotrophic methanolutilizer. The Methylocystis strain contains the three plasmids we had observed previously in methane-grown cultures, while the Xanthobacter strain contains no detectible plasmids. Therefore, our original approach to studying the methane oxidation genes, that of isolating plasmid mutants, is no longer valid. However, our discovery of the nature of this culture has led to some interesting results which show promise in elucidating the genetic structure of the methane oxidation genes in obligate methanotrophs. In addition, we have been successful in developing mutagenesis, gene transfer and cloning systems that are applicable to a wide variety of methanotrophs.

  19. Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report No. 1, October--December 1992

    SciTech Connect

    McCormick, R.L.; Jha, M.C.

    1993-03-04

    Amax R&D will perform laboratory scale development of a promising, practical catalyst for the selective oxidation of methane to methanol. The primary component of this catalyst is vanadium-phosphate (VPO) which has shown good activity and selectivity in the partial oxidation of n-butane and propane but has not been studied in detail for methane oxidation. The goal of the project is to develop a catalyst which allows methane oxidation to methanol to be conducted at high conversion and selectivity. A low CH{sub 4}/O{sub 2} ratio will be employed with air as the source of oxygen. Temperatures below 600{degrees}C and pressures up to 20 atm are to be investigated. The use of steam in the feed gas will also be investigated. The catalyst development strategy will be to utilize promoters and supports to improve the activity and selectivity of the unmodified VPO catalyst. The catalyst testing reactor system was used to perform blank (empty) reactor runs over a wide range of temperatures, pressure, and flow rates. No methane conversion was observed at temperatures of 500{degrees}C or lower in any of the tests. At higher temperatures, significant methane conversion to carbon dioxide was observed. At 550{degrees}C, 300 psig, and the highest flow rate studied, reactor ignition was observed. Based on the results of these blank runs, we conclude that catalyst testing should be performed at temperatures not to exceed 500{degrees}C.

  20. Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report 8, January--March, 1995

    SciTech Connect

    McCormick, R.L.

    1995-05-25

    Activities during this quarter focused on fine tuning of catalyst characterization and synthesis techniques. Improvements in catalyst activity test methods were also implemented but more remains to be done. Specific accomplishments include: improved characterization of vanadyl pyrophosphate (VPO) and Si promoted VPO by FTIR and FTIR of chemisorbed bases; several minor improvements in catalyst preparation technique resulting in enhanced catalyst yield, better control of catalyst composition, and generation of less waste; preliminary pulsed reaction data on methane oxidation were also acquired. Preliminary activity measurements for methane conversion (without oxygen) in a pulsed reactor over VPO indicate that the primary reaction product is CO. Carbon dioxide is also formed but selectivity to CO{sub 2} decreases with number of pulses. These results suggest that selectivity to partially oxidized products improves with catalyst reduction and suggest that some surface modification will be required to obtain oxidized hydrocarbon products. Note that catalyst activation (conversion from the precursor to VPO) has been carried out using air. For butane oxidation catalysts VPO is activated in a 1% butane/air mixture which produces a slightly reduced catalyst.

  1. The contribution of reactive oxygen species and p38 mitogen-activated protein kinase to myofilament oxidation and progression of heart failure in rabbits

    PubMed Central

    Heusch, P; Canton, M; Aker, S; van de Sand, A; Konietzka, I; Rassaf, T; Menazza, S; Brodde, OE; Di Lisa, F; Heusch, G; Schulz, R

    2010-01-01

    Background and purpose: The formation of reactive oxygen species (ROS) is increased in heart failure (HF). However, the causal and mechanistic relationship of ROS formation with contractile dysfunction is not clear in detail. Therefore, ROS formation, myofibrillar protein oxidation and p38 MAP kinase activation were related to contractile function in failing rabbit hearts. Experimental approach and key results: Three weeks of rapid left ventricular (LV) pacing reduced LV shortening fraction (SF, echocardiography) from 32 ± 1% to 13 ± 1%. ROS formation, as assessed by dihydroethidine staining, increased by 36 ± 8% and was associated with increased tropomyosin oxidation, as reflected by dimer formation (dimer to monomer ratio increased 2.28 ± 0.66-fold in HF vs. sham, P < 0.05). Apoptosis (TdT-mediated dUTP nick end labelling staining) increased more than 12-fold after 3 weeks of pacing when a significant increase in the phosphorylation of p38 MAP kinase and HSP27 was detected (Western blotting). Vitamins C and E abolished the increases in ROS formation and tropomyosin oxidation along with an improvement of LVSF (19 ± 1%, P < 0.05 vs. untreated HF) and prevention of apoptosis, but without modifying p38 MAP kinase activation. Inhibition of p38 MAP kinase by SB281832 counteracted ROS formation, tropomyosin oxidation and contractile failure, without affecting apoptosis. Conclusions and implications: Thus, p38 MAP kinase activation appears to be upstream rather than downstream of ROS, which impacts on LV function through myofibrillar oxidation. p38 MAP kinase inhibition is a potential target to prevent or treat HF. PMID:20590631

  2. Oral Administration of Aloe vera (L.) Burm. f. (Xanthorrhoeaceae) and Honey Improves the Host Body Composition and Modulates Proteolysis Through Reduction of Tumor Progression and Oxidative Stress in Rats.

    PubMed

    Tomasin, Rebeka; de Andrade, Rafael Siqueira; Gomes-Marcondes, Maria Cristina Cintra

    2015-10-01

    Oxidative stress has a dual role in cancer; it is linked with tumorigenic events and host wasting, as well as senescence and apoptosis. Researchers have demonstrated the importance of coadjuvant therapies in cancer treatment, and Aloe vera and honey have immunomodulatory, anticancer, and antioxidant properties. The preventive and therapeutic effects of Aloe vera (L.) Burm. f. (Xanthorrhoeaceae) and honey in tumor progression and host wasting were analyzed in Walker 256 carcinoma-bearing rats. The animals were distributed into the following groups: C=control-untreated, W=tumor-untreated, WA=treated after tumor induction, A=control-treated, AW=treated before tumor induction, and AWA=treated before and after tumor induction. Proteolysis and oxidative stress were analyzed in the tumor, liver, muscle, and myocardial tissues. The results suggest that the Aloe vera and honey treatment affect the tumor and host by different mechanisms; the treatment-modulated host wasting and cachexia, whereas it promoted oxidative stress and damage in tumor tissues, particularly in a therapeutic context (WA).

  3. Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report 11, October--December 1995

    SciTech Connect

    McCormick, R.L.

    1996-04-16

    Activities during this report period focused on testing of additional modified and promoted catalysts and characterization of these materials. Methanol oxidation studies were performed as a method of acid site characterization. Improvements to the product gas analysis system continued to be developed. These results are reported. Specific accomplishments include: (1) Obtaining and interpreting infrared spectra of modified catalysts prepared to enhance surface acidity. (2) Testing of these catalysts in methanol oxidation as a method of acid site characterization and to determine catalytic activity for conversion of this desired product. Catalysts were quite active for methanol conversion to dimethyl ether. Two of the modified catalysts prepared in this work exhibited the highest activity for this reaction, presumably because of their higher surface areas. (3) Determination that acidity modifications had no effect on activity for methane conversion.

  4. Recent progress on elaboration of undoped and doped Y2O3, Gd2O3 rare-earth nano-oxide.

    PubMed

    Lebbou, K; Perriat, P; Tillement, O

    2005-09-01

    Some selected materials with small sizes in the nanometer region are reviewed. Different methods for synthesis of nanoscale materials are classified and discussed. Basic prerequisites for successful use of the materials for nanotechnology application are their synthesis with specific and homogeneous composition and geometry. This review summarizes recent results on nanoscale materials containing optically active lanthanide ion especially focused on Y2O3 and Gd2O3 oxide.

  5. Effect of Heavy metals on the iron oxidizing ability of Thiobacillus ferrooxidans: Part 1, Effect of silver. Technical progress report, July 1992--September 1992

    SciTech Connect

    De, G.C.; Pesic, B.

    1992-12-01

    The effect of silver ions on the iron oxidizing ability of Thiobacillus ferrooxidans was studied using electrochemical and other physics-chemical techniques. Electrochemical investigation was conducted using a method based on redox potential change. Experiments were performed by adding an aliquot of separately prepared concentrate of the bacteria into the solution of ferrous ion and monitoring the redox potential for at least one hour. Pyrite was used as the indicator electrode. Parameters examined were pH, microbial cell density, ferrous, ferric and silver ion concentration, temperature and preconditioning period of the bacteria with silver ions, etc. Results obtained demonstrate that the rate of ferrous ion oxidation is dependent on pH (optimum pH range is 1.5--2.0) and the substrate (i.e. Fe(II)) to microbial cell concentration ratio. The mechanism of the bacteria mediated oxidation of ferrous iron is remarkably sensitive to temperature changes. At the vicinity of the optimum temperature (i.e. 25{degree}C), the reaction is likely to be controlled by the diffusion of Fe (II) ions through the cell wall of the bacteria, whereas below the range 18--25{degree}C, reaction kinetics may be the rate controlling factor. In the presence of 10 mg/L silver, the reaction may be kinetically controlled over the temperature range 5.5--25{degree}C. Inhibition of microbial FE(II) oxidation in the presence of silver may take place via a mixed mechanism in which silver may bind with both the enzyme and the enzyme-substrate complex.

  6. Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report 13, April--June, 1996

    SciTech Connect

    McCormick, R.L.; Alptekin, G.O.

    1996-07-30

    The specific objectives of this project are: to determine optimum conditions for methanol and formaldehyde production from methane using VPO catalysts, in particular to determine the effect of lean conditions (excess oxygen), oxygen deficient conditions (used in most other methane oxidation studies), and the potential of using the catalyst as a stoichiometric oxidant or oxygen carrier; to utilize promoters and catalyst supports to improve oxygenate yield relative to the base case catalysts; to provide a preliminary understanding of how these promoters and supports actually effect catalyst properties; and use the information obtained to prepare advanced catalysts which will be tested for activity, selectivity, and stability. Activities this quarter included analysis of all previously acquired data for methane, methanol, and formaldehyde oxidation over vanadyl pyrophosphate and testing of supported, promoted, and iron phosphate catalysts. Some experiments have been conducted with a small percentage of butane in the feed gas to help retain the catalyst in a reduced state and these results are reported. Iron phosphate, and iron phosphate supported on silica have also been tested in a preliminary way.

  7. Role of NADPH oxidases in inducing a selective increase of oxidant stress and cyclin D1 and checkpoint 1 over-expression during progression to human gastric adenocarcinoma.

    PubMed

    Montalvo-Javé, Eduardo E; Olguín-Martínez, Marisela; Hernández-Espinosa, Diego R; Sánchez-Sevilla, Lourdes; Mendieta-Condado, Edgar; Contreras-Zentella, Martha L; Oñate-Ocaña, Luis F; Escalante-Tatersfield, Tomás; Echegaray-Donde, Agustín; Ruiz-Molina, Juan M; Herrera, Miguel F; Morán, Julio; Hernández-Muñoz, Rolando

    2016-04-01

    Gastric cancer is one of the main causes of global mortality. Here, reactive oxygen species (ROS) could largely contribute to gastric carcinogenesis. Hence, the present work was aimed to assess the role of ROS, oxidant status, NADPH oxidases (NOXs) expression, during human gastric adenocarcinoma. We obtained subcellular fraction from samples of gastric mucosa taken from control subjects (n = 20), and from 40 patients with gastric adenocarcinoma, as well as samples of distant areas (tumour-free gastric mucosa). Parameters indicative of lipid peroxidation and cell proliferation were selectively increased in both tumour-free and in cancerous gastric mucosa, despite of glutathione (GSH) content, glutathione reductase (GR) and superoxide dismutase (SOD) activities were increased in the adenocarcinoma. These high levels of antioxidant defences inversely correlated with down-regulated expression for NOX2 and 4; however, over-expression of NOX1 occurred with increased caspase-3 activity and overexpressed checkpoint 1 (MDC1) and cyclin D1 proteins. In the tumour-free mucosa an oxidant stress took place, without changing total GSH but with decreased activities for GR and mitochondrial SOD; moreover, over-expression of checkpoint 1 (MDC1) correlated with lower NOX2 and 4 expression in this mucosa. Chronically injured gastric mucosa increases lipoperoxidative events and cell proliferation. In the adenocarcinoma, cell proliferation was further enhanced, oxidant stress decreased which seemed to be linked to NOX1, MDC1 and cyclin D1 over-expression, but with a lower NOXs activity leading a 'low tone' of ROS formation. Therefore, our results could be useful for early detection and treatment of gastric adenocarcinoma. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. An investigation of molybdenum and molybdenum oxide catalyzed hydrocarbon formation reactions. Second period progress report, August 1, 1993--April 1, 1994

    SciTech Connect

    Not Available

    1994-06-01

    Equipment construction include: uv source, vacuum system with mass spectrometer, Auger analyzer, fast sample transfer cell, and infrared spectrometer detector. Mo and Mo oxide catalysts were tested for activity for olefin (propylene) metathesis. Higher hydrocarbons were also formed in this reaction in parallel with metathesis products. Surface chemistry experiments were carried out on metallic surfaces in ultrahigh vacuum, photoelectron MoO{sub 2} and its reduction, and Mo(CO){sub 6} adsorption on alumina. Identification of surface species using near-edge x-ray adsorption fine structure is discussed.

  9. Comparative study of the reactions of metal oxides with H{sub 2}S and SO{sub 2}. Technical progress report, April--June 1991

    SciTech Connect

    Sotirchos, S.V.

    1991-07-01

    The primary objective of this project is the investigation of the effects of pore structure on the capacity of porous metal oxides for removal of gaseous pollutants from flue gases of power plants (SO{sub 2}) and hot coal gas (primarily H{sub 2}S). Specifically, we intend to appropriately exploit the differences of the sulfidation and sulfation reactions (for instance, different molar volumes of solid products) to elucidate the dependence of the sorptive capacity of a porous sorbent on its physical microstructure.

  10. Comparison of lime and iron oxide for high temperature sulfur removal. Technical progress report No. 6, March 1, 1991--May 31, 1991

    SciTech Connect

    Reid, K.J.

    1991-12-31

    Slagging combustors with injected lime or limestone are being considered as replacements for conventional coal burners. They have advantage in that they can be staged to reduce NO{sub x} and SO{sub x} emissions. Lime or limestone are the currently preferred sorbent materials but iron oxide, as an alternative to lime or limestone, may be effective not only as a desulfurizing agent, but, under the right conditions of oxygen potential, it can act as a flux to produce a glassy slag. This glassy slag should be dense and environmentally inert.

  11. Innovative Clean Coal Technology (ICCT): 180 MW demonstration of advanced tangentially-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report, third quarter 1991

    SciTech Connect

    Not Available

    1992-02-03

    This quarterly report discusses the technical progress of a US Department of Energy (DOE) Innovative Clean Coal Technology (ICCT) Project demonstrating advanced tangentially-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from a coal-fired boiler. The project is being conducted at Gulf Power Company`s Plant Lansing Smith Unit 2 located near Panama City, Florida. The primary objective of this demonstration is to determine the long-term effects of commercially available tangentially-fired low NO{sub x} combustion technologies on NO{sub x} emissions and boiler performance. A target of achieving fifty percent NO{sub x} reduction using combustion modifications has been established for the project.

  12. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report, second quarter 1994, April 1994--June 1994

    SciTech Connect

    1995-09-01

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NOx combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NOx reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NOx burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NOx reductions of each technology and evaluate the effects of those reductions on other combustion parameters. Results are described.

  13. Hemoglobin induced lung vascular oxidation, inflammation, and remodeling contributes to the progression of hypoxic pulmonary hypertension and is attenuated in rats with repeat dose haptoglobin administration

    PubMed Central

    Baek, Jin Hyen; Hassell, Kathryn; Nuss, Rachelle; Eigenberger, Paul; Lisk, Christina; Loomis, Zoe; Maltzahn, Joanne; Stenmark, Kurt R; Nozik-Grayck, Eva

    2015-01-01

    Objective Haptoglobin (Hp) is an approved treatment in Japan with indications for trauma, burns and massive transfusion related hemolysis. Additional case reports suggest uses in other acute hemolytic events that lead to acute kidney injury. However, Hp's protective effects on the pulmonary vasculature have not been evaluated within the context of mitigating the consequences of chronic hemoglobin (Hb) exposure in the progression of pulmonary hypertension (PH) secondary to hemolytic diseases. This study was performed to assess the utility of chronic Hp therapy in a preclinical model of Hb and hypoxia mediated PH. Approach and results Rats were simultaneously exposed to chronic Hb-infusion (35 mg per day) and hypobaric hypoxia for five weeks in the presence or absence of Hp treatment (90 mg/kg twice a week). Hp inhibited the Hb plus hypoxia-mediated non-heme iron accumulation in lung and heart tissue, pulmonary vascular inflammation and resistance, and right ventricular hypertrophy, which suggest a positive impact on impeding the progression of PH. In addition, Hp therapy was associated with a reduction in critical mediators of PH, including lung adventitial macrophage population and endothelial ICAM-1 expression. Conclusions By preventing Hb-mediated pathology, Hp infusions: (1) demonstrate a critical role for Hb in vascular remodeling associated with hypoxia; and (2) suggest a novel therapy for chronic hemolysis associated PH. PMID:25656991

  14. Quercetin offers cardioprotection against progression of experimental autoimmune myocarditis by suppression of oxidative and endoplasmic reticulum stress via endothelin-1/MAPK signalling.

    PubMed

    Arumugam, Somasundaram; Thandavarayan, Rajarajan A; Arozal, Wawaimuli; Sari, Flori R; Giridharan, Vijayasree V; Soetikno, Vivian; Palaniyandi, Suresh S; Harima, Meilei; Suzuki, Kenji; Nagata, Masaki; Tagaki, Ritsuo; Kodama, Makoto; Watanabe, Kenichi

    2012-02-01

    In order to test the hypothesis that treatment with quercetin at a dose of 10 mg/kg protects from the progression of experimental autoimmune myocarditis (EAM) to dilated cardiomyopathy (DCM), we have used the rat model of EAM induced by porcine cardiac myosin. Our results identified that the post-myocarditis rats suffered from elevated endoplasmic reticulum (ER) stress and adverse cardiac remodelling in the form of myocardial fibrosis, whereas the rats treated with quercetin have been protected from these changes as evidenced by the decreased myocardial levels of ER stress and fibrosis markers when compared with the vehicle-treated DCM rats. In addition, the myocardial dimensions and cardiac function were preserved significantly in the quercetin-treated rats in comparison with the DCM rats treated with vehicle alone. Interestingly, the rats treated with quercetin showed significant suppression of the myocardial endothelin-1 and also the mitogen activated protein kinases (MAPK) suggesting that the protection offered by quercetin treatment against progression of EAM involves the modulation of MAPK signalling cascade. Collectively, the present study provides data to support the role of quercetin in protecting the hearts of the rats with post myocarditis DCM.

  15. Hemoglobin-induced lung vascular oxidation, inflammation, and remodeling contribute to the progression of hypoxic pulmonary hypertension and is attenuated in rats with repeated-dose haptoglobin administration.

    PubMed

    Irwin, David C; Baek, Jin Hyen; Hassell, Kathryn; Nuss, Rachelle; Eigenberger, Paul; Lisk, Christina; Loomis, Zoe; Maltzahn, Joanne; Stenmark, Kurt R; Nozik-Grayck, Eva; Buehler, Paul W

    2015-05-01

    Haptoglobin (Hp) is an approved treatment in Japan for trauma, burns, and massive transfusion-related hemolysis. Additional case reports suggest uses in other acute hemolytic events that lead to acute kidney injury. However, Hp's protective effects on the pulmonary vasculature have not been evaluated within the context of mitigating the consequences of chronic hemoglobin (Hb) exposure in the progression of pulmonary hypertension (PH) secondary to hemolytic diseases. This study was performed to assess the utility of chronic Hp therapy in a preclinical model of Hb and hypoxia-mediated PH. Rats were simultaneously exposed to chronic Hb infusion (35 mg per day) and hypobaric hypoxia for 5 weeks in the presence or absence of Hp treatment (90 mg/kg twice a week). Hp inhibited the Hb plus hypoxia-mediated nonheme iron accumulation in lung and heart tissue, pulmonary vascular inflammation and resistance, and right-ventricular hypertrophy, which suggests a positive impact on impeding the progression of PH. In addition, Hp therapy was associated with a reduction in critical mediators of PH, including lung adventitial macrophage population and endothelial ICAM-1 expression. By preventing Hb-mediated pathology, Hp infusions: (1) demonstrate a critical role for Hb in vascular remodeling associated with hypoxia and (2) suggest a novel therapy for chronic hemolysis-associated PH.

  16. Demonstration of omnivorous non-thermal mixed waste treatment: Direct chemical oxidation using peroxydisulfate. Progress report SF2-3-MW-35, October--December 1995

    SciTech Connect

    Cooper, J.F.; Wang, F.; Krueger, R.; King, K.; Shell, T.; Farmer, J.C.; Adamson, M.

    1996-01-27

    Direct Chemical Oxidation is an emerging ``omnivorous`` waste destruction technique which uses one of the strongest known oxidants (ammonium peroxydisulfate) to convert organic solids or liquids to carbon dioxide and their mineral constituents. The process operates at ambient pressure and at moderate temperatures (80--100 C) where organic destruction is rapid without catalysts. The byproduct (ammonium sulfate) is benign and may be recycled using commercial electrolysis equipment. The authors have constructed and initially tested a bench-scale facility (batch prereactor and plug-flow reactor) which allows treatability tests on any solid or liquid organic waste surrogate, with off-gas analysis by mass spectroscopy. Shake-down tests of the plug flow reactor on model chemical ethylene glycol confirmed earlier predictive models. Pre-reactor tests on water-immiscible substances confirmed destruction of cotton rags (cellulose), kerosene, tributyl phosphate and triethylamine. The process is intended to provide an all-aqueous, ambient pressure destruction technique for difficult materials not suitable or fully accepted for conventional incineration. Such wastes include solid and liquid mixed wastes containing incinerator chars, halogenated and nitrogenated wastes, oils and greases, and chemical or biological warfare agents.

  17. Ionic liquid hybrids: Progress toward non-corrosive electrolytes with high-voltage oxidation stability for magnesium-ion based batteries

    DOE PAGES

    Huie, Matthew M.; Cama, Christina A.; Smith, Paul F.; ...

    2016-10-01

    Magnesium – ion batteries have the potential for high energy density but require new types of electrolytes for practical application. Ionic liquid (IL) electrolytes offer the opportunity for increased safety and broader voltage windows relative to traditional electrolytes. We present here a systematic study of both the conductivity and oxidative stability of hybrid electrolytes consisting of eleven ILs mixed with dipropylene glycol dimethylether (DPGDME) or acetonitrile (ACN) cosolvents and magnesium bis(trifluoromethylsulfonyl)imide (Mg(TFSI)2). Our study finds a correlation of higher conductivity of ILs with unsaturated rings and short carbon chain lengths, but by contrast, these ILs also exhibited lower oxidation voltagemore » limits. For the cosolvent additive, although glymes have a demonstrated capability of coordination with Mg2+ ions, a decrease in conductivity compared to acetonitrile hybrid electrolytes was observed. Lastly, when cycled within the appropriate voltage range, the IL-hybrid electrolytes that show the highest conductivity provide the best cathode magnesiation current densities and lowest polarization as demonstrated with a Mg0.15MnO2 and Mg0.07V2O5 cathodes.« less

  18. Ionic liquid hybrids: Progress toward non-corrosive electrolytes with high-voltage oxidation stability for magnesium-ion based batteries

    SciTech Connect

    Huie, Matthew M.; Cama, Christina A.; Smith, Paul F.; Yin, Jiefu; Marschilok, Amy C.; Takeuchi, Kenneth J.; Takeuchi, Esther S.

    2016-10-01

    Magnesium – ion batteries have the potential for high energy density but require new types of electrolytes for practical application. Ionic liquid (IL) electrolytes offer the opportunity for increased safety and broader voltage windows relative to traditional electrolytes. We present here a systematic study of both the conductivity and oxidative stability of hybrid electrolytes consisting of eleven ILs mixed with dipropylene glycol dimethylether (DPGDME) or acetonitrile (ACN) cosolvents and magnesium bis(trifluoromethylsulfonyl)imide (Mg(TFSI)2). Our study finds a correlation of higher conductivity of ILs with unsaturated rings and short carbon chain lengths, but by contrast, these ILs also exhibited lower oxidation voltage limits. For the cosolvent additive, although glymes have a demonstrated capability of coordination with Mg2+ ions, a decrease in conductivity compared to acetonitrile hybrid electrolytes was observed. Lastly, when cycled within the appropriate voltage range, the IL-hybrid electrolytes that show the highest conductivity provide the best cathode magnesiation current densities and lowest polarization as demonstrated with a Mg0.15MnO2 and Mg0.07V2O5 cathodes.

  19. Ionic liquid hybrids: Progress toward non-corrosive electrolytes with high-voltage oxidation stability for magnesium-ion based batteries

    SciTech Connect

    Huie, Matthew M.; Cama, Christina A.; Smith, Paul F.; Yin, Jiefu; Marschilok, Amy C.; Takeuchi, Kenneth J.; Takeuchi, Esther S.

    2016-10-01

    Magnesium – ion batteries have the potential for high energy density but require new types of electrolytes for practical application. Ionic liquid (IL) electrolytes offer the opportunity for increased safety and broader voltage windows relative to traditional electrolytes. We present here a systematic study of both the conductivity and oxidative stability of hybrid electrolytes consisting of eleven ILs mixed with dipropylene glycol dimethylether (DPGDME) or acetonitrile (ACN) cosolvents and magnesium bis(trifluoromethylsulfonyl)imide (Mg(TFSI)2). Our study finds a correlation of higher conductivity of ILs with unsaturated rings and short carbon chain lengths, but by contrast, these ILs also exhibited lower oxidation voltage limits. For the cosolvent additive, although glymes have a demonstrated capability of coordination with Mg2+ ions, a decrease in conductivity compared to acetonitrile hybrid electrolytes was observed. Lastly, when cycled within the appropriate voltage range, the IL-hybrid electrolytes that show the highest conductivity provide the best cathode magnesiation current densities and lowest polarization as demonstrated with a Mg0.15MnO2 and Mg0.07V2O5 cathodes.

  20. miRNA-133a-UCP2 pathway regulates inflammatory bowel disease progress by influencing inflammation, oxidative stress and energy metabolism

    PubMed Central

    Jin, Xi; Chen, Dong; Zheng, Ruo-Heng; Zhang, Hong; Chen, Yi-Peng; Xiang, Zun

    2017-01-01

    AIM To investigate the role of the miR-133a-UCP2 pathway in the pathogenesis of inflammatory bowel disease (IBD) and to explore the potential downstream mechanisms with respect to inflammation, oxidative stress and energy metabolism. METHODS C57BL/6 mice were fed dextran sulfate sodium (DSS) liquid for 7 consecutive days, followed by the administration of saline to the DSS group, UCP2 siRNA to the UCP2 group and a miR-133a mimic to the miR-133a group on days 8 and 11. Body weight, stool consistency and rectal bleeding were recorded daily, and these composed the disease activity index (DAI) score for the assessment of disease severity. After cervical dislocation was performed on day 14, the length of the colon in each mouse was measured, and colonic tissue was collected for further study, which included the following: haematoxylin and eosin staining, UCP2 and miR-133a detection by immunohistochemical staining, western blot and quantitative real-time PCR, measurement of apoptosis by TUNEL assay, and the assessment of inflammation (TNF-α, IL-1β, IL-6 and MCP1), oxidative stress (H2O2 and MDA) and metabolic parameters (ATP) by ELISA and colorimetric methods. RESULTS An animal model of IBD was successfully established, as shown by an increased DAI score, shortened colon length and specific pathologic changes, along with significantly increased UCP2 and decreased miR-133a levels. Compared with the DSS group, the severity of IBD was alleviated in the UCP2 and the miR-133a groups after successful UCP2 knockdown and miR-133a overexpression. The extent of apoptosis, as well as the levels of TNF-α, IL-1β, MDA and ATP, were significantly increased in both the UCP2 and miR-133a groups compared with the DSS group. CONCLUSION The miR-133a-UCP2 pathway participates in IBD by altering downstream inflammation, oxidative stress and markers of energy metabolism, which provides novel clues and potential therapeutic targets for IBD. PMID:28104982

  1. Mulberry leaf diet protects against progression of experimental autoimmune myocarditis to dilated cardiomyopathy via modulation of oxidative stress and MAPK-mediated apoptosis.

    PubMed

    Arumugam, Somasundaram; Mito, Sayaka; Thandavarayan, Rajarajan A; Giridharan, Vijayasree V; Pitchaimani, Vigneshwaran; Karuppagounder, Vengadeshprabhu; Harima, Meilei; Nomoto, Mayumi; Suzuki, Kenji; Watanabe, Kenichi

    2013-12-01

    To examine the protective effects of dietary administration of Mulberry leaves (ML) on postmyocarditis dilated cardiomyopathy (DCM) focusing on oxidative and endoplasmic reticulum stresses and adverse myocardial remodeling. In this study, we used a rat model of cardiac myosin-induced experimental autoimmune myocarditis to test the effects of ML diet (MLD) (5%) on various markers of cardiac remodeling and function. After 4 weeks of immunization, the rats were fed with 5% MLD for 4 weeks. By the end of the study, echocardiography was performed to assess the myocardial dimensions. The heart tissue was used for histopathology and Western blotting analyses. Our study showed that the postmyocarditis rats exhibited increased oxidative stress when compared with the control rats. MLD supplementation suppressed this change, compared with vehicle treatment. In addition, postmyocarditis rats showed significant elevation of the endoplasmic reticulum stress markers, which were prevented by the MLD supplementation. Similarly the vehicle-treated rats suffered with the adverse myocardial remodeling in the form of fibrosis as evidenced by the Azan-Mallory staining and immunohistochemistry for collagen-III levels, compared with the control rats. However, MLD treatment not only markedly attenuated cardiac fibrosis, but also improved the left ventricular ejection fraction and fractional shortening. Interestingly, the myocardial levels of endothelin-1, activated members of mitogen-activated protein kinase (MAPK) pathway, and vascular endothelial growth factor (VEGF) were significantly attenuated by MLD, indicating that the antihypertrophic effects of MLD are partially mediated via endothelin-1, MAPK, and VEGF pathway. Collectively, these results suggest that supplementation of rats with 5% MLD has the ability to regulate cardiac remodeling and improves cardiac function and hence contributes to prevent the development of postmyocarditis dilated cardiomyopathy. © 2013 John Wiley

  2. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report, second quarter 1995

    SciTech Connect

    1995-12-31

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. The project provides a stepwise evaluation of the following NO{sub x} reduction technologies: advanced overfire air (AOFA), low NO{sub x} burners (LNB), LNB with AOFA, and advanced digital controls and optimization strategies. The project has completed the baseline, AOFA, LNB, and LNB + AOFA test segments, fulfilling all testing originally proposed to DOE. Phase 4 of the project, demonstration of advanced control/optimization methodologies for NO{sub x} abatement, is now in progress. The methodology selected for demonstration at Hammond Unit 4 is the Generic NO{sub x} Control Intelligent System (GNOCIS), which is being developed by a consortium consisting of the Electric Power Research institute, PowerGen, Southern Company, Radian Corporation, U.K. Department of Trade and Industry, and US DOE. GNOCIS is a methodology that can result in improved boiler efficiency and reduced NO{sub x} emissions from fossil fuel fired boilers. Using a numerical model of the combustion process, GNOCIS applies an optimizing procedure to identify the best set points for the plant on a continuous basis. GNOCIS is designed to operate in either advisory or supervisory modes. Prototype testing of GNOCIS is in progress at Alabama Power`s Gaston Unit 4 and PowerGen`s Kingsnorth Unit 1.

  3. Evodiamine inhibits PDGF-BB-induced proliferation of rat vascular smooth muscle cells through the suppression of cell cycle progression and oxidative stress

    PubMed Central

    Ge, Xie; Chen, Si-Yu; Liu, Mei; Liang, Ting-Ming; Liu, Chang

    2016-01-01

    Vascular smooth muscle cell (VSMC) proliferation is a key event in the development of in-stent restenosis. Evodiamine is an indole alkaloid extracted from the Chinese medicine, evodia, and has been shown to inhibit tumor cell proliferation and protect the cardiovascular system. However, whether evodiamine affects VSMC proliferation remains to be elucidated. Therefore, the present study examined the effects and the mechanisms of action of evodiamine on the proliferation of rat VSMCs. The cells were treated with evodiamine alone or in combination with platelet-derived growth factor-BB (PDGF-BB) stimulation. It was found that evodiamine inhibited PDGF-BB-induced VSMC proliferation in a dose-dependent manner, without inducing cell death. Evodiamine also retarded cell cycle progression, evidenced by the suppression of the expression of cell cycle-promoting cyclin proteins and cyclin-dependent kinases. In addition, evodiamine attenuated the PDGF-BB-induced phosphorylation of mitogen-activated protein kinases p38 and extracellular signal-regulated kinases 1/2, however, it had no effect on the phosphorylation of Akt. Evodiamine also inhibited the increase of reactive oxygen species generation and upregulated the mRNA expression levels of genes encoding antioxidant enzymes. These findings provide important insights into the mechanisms underlying the vasoprotective actions of evodiamine and suggest that it may be a useful therapeutic agent for the treatment of vascular occlusive disease. PMID:27748810

  4. Comparative study of the reactions of metal oxides with H{sub 2}S and SO{sub 2}. Technical progress report, July--September 1991

    SciTech Connect

    Sotirchos, S.V.

    1991-10-01

    The primary objective of this project is the investigation of the effects of pore structure on the capacity of porous metal oxides for removal of gaseous pollutants from flue gases of power plants (SO{sub 2}) and hot coal gas (primarily H{sub 2}S). Specifically, we intend to appropriately exploit the differences of the sulfidation and sulfation reactions (for instance, different molar volumes of solid products) to elucidate the dependence of the sorptive capacity of a porous sorbent on its physical microstructure. The following tasks have been identified in the proposed project: (1) Literature survey and identification of solids to be used in experimental studies. (2) Experimental study of the reaction of the chosen solids with SO{sub 2} and/or H{sub 2}S. (3) Experimental study of the evolution of the structure of the solids during reaction with SO{sub 2} and/or H{sub 2}S using pore structure analysis and effective diffusivity measurements. (4) Model testing and validation using the obtained experimental data.

  5. Neutronics Benchmarks for the Utilization of Mixed-Oxide Fuel: Joint U.S./Russian Progress Report for Fiscal Year 1997

    SciTech Connect

    Akkurt, H

    2001-01-11

    In 1967, a series of critical experiments were conducted at the Westinghouse Reactor Evaluation Center (WREC) using mixed-oxide (MOX) PuO{sub 2}-UO{sub 2} and/or UO{sub 2} fuels in various lattices and configurations . These experiments were performed under the joint sponsorship of the Empire State Atomic Development Associates (ESADA) plutonium program and Westinghouse . The purpose of these experiments was to develop experimental data to validate analytical methods used in the design of a plutonium-bearing replacement fuel for water reactors. Three different fuels were used during the experimental program: two MOX fuels and a low-enriched UO{sub 2} fuel. The MOX fuels were distinguished by their {sup 240}Pu content: 8 wt% {sup 240}Pu and 24 wt% {sup 240}Pu. Both MOX fuels contained 2.0 wt % PuO{sub 2} in natural UO{sub 2} . The UO{sub 2} fuel with 2.72 wt % enrichment was used for comparison with the plutonium data and for use in multiregion experiments.

  6. Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report No.2, January--March 1993

    SciTech Connect

    McCormick, R.L.; Jha, M.C.

    1993-05-11

    During the second quarter, we initiated Task 2 (Process and Catalyst Variable Study). This task involves an investigation of methods for vanadium phosphate (VPO) catalyst synthesis and activation as well as detailed testing of the catalysts produced for activity and selectivity in methane selective oxidation. As we initiated work on Task 2, three problem areas were identified: Preparation of catalysts with P:V ratio greater than 1. Activation of the precursor to produce the B-phase described in the patent literature. Achieving high (>95 percent) carbon balances in the bench-scale test unit. Each of these problems has been addressed and overcome during this quarter. Several catalysts with P:V ratios ranging from 0.95 to 1.1 have been prepared. Activation procedures are continuing to be investigated. We have found several procedures which yield catalysts having the desired X-ray diffraction pattern. The reactor system was modified and analytical procedures improved so that in a 7-day run using V{sub 2}O{sub 5} as the catalyst, carbon balances ranged from 95 to 105 percent.

  7. Progress toward understanding the effects of the oxidation state of H-O-S-Cl-bearing fluids on metal partitioning in magmatic systems (Invited)

    NASA Astrophysics Data System (ADS)

    Simon, A. C.

    2009-12-01

    in some inclusion assemblages is related simply to a metal preference for a soft vs. a borderline base. Or could the preference for S be a function of the sulfur speciation in the volatile phase. Further, data from natural sulfide-melt pairs demonstrate that both Cu and Au are highly soluble in sulfide phases with the expectation that sulfide fractionation should result in a roughly equal decrease in the concentration of both metals. In this talk, I have compiled all available data on the melt/fluid and melt/crystal partitioning of Cu and Au in a H-O-S-Cl-fluid(s)-saturated silicate melt assemblage in an attempt to elucidate the differences in ore metal tenor and ratios as a function of variation in the fugacities of oxygen and sulfur, the ratio of reduced to oxidized sulfur, and the competition between chlorine and sulfur. The data suggest that sulfur and oxygen fugacity, and the ratio of H2S/SO2 are critical controls on ore metal fractionation. These variables control the solubility of metal(s) and sulfur in the silicate melt, the metal-sequestering-capacity of sulfides and oxides, and the partitioning of metal(s) and sulfur between silicate melt and an H-O-S-Cl fluid. Any model of ore metal behavior must account for the interdependent nature of these variables.

  8. Slowing down glioblastoma progression in mice by running or the anti-malarial drug dihydroartemisinin? Induction of oxidative stress in murine glioblastoma therapy

    PubMed Central

    Lemke, Dieter; Pledl, Hans-Werner; Zorn, Markus; Jugold, Manfred; Green, Ed; Blaes, Jonas; Löw, Sarah; Hertenstein, Anne; Ott, Martina; Sahm, Felix; Steffen, Ann-Catherine; Weiler, Markus; Winkler, Frank; Platten, Michael

    2016-01-01

    Influencing cancer metabolism by lifestyle changes is an attractive strategy as - if effective - exercise-induced problems may be less severe than those induced by classical anti-cancer therapies. Pursuing this idea, clinical trials evaluated the benefit of e.g. different diets such as the ketogenic diet, intermittent caloric restriction and physical exercise (PE) in the primary and secondary prevention of different cancer types. PE proved to be beneficial in the context of breast and colon cancer. Glioblastoma has a dismal prognosis, with an average overall survival of about one year despite maximal safe resection, concomitant radiochemotherapy with temozolomide followed by adjuvant temozolomide therapy. Here, we focused on the influence of PE as an isolated and adjuvant treatment in murine GB therapy. PE did not reduce toxic side effects of chemotherapy in mice administered in a dose escalating scheme as shown before for starvation. Although regular treadmill training on its own had no obvious beneficial effects, its combination with temozolomide was beneficial in the treatment of glioblastoma-bearing mice. As PE might partly act through the induction of reactive oxygen species, dihydroartemisinin - an approved anti-malarial drug which induces oxidative stress in glioma cells - was further evaluated in vitro and in vivo. Dihydroartemisinin showed anti-glioma activity by promoting autophagy, reduced the clonogenic survival and proliferation capacity of glioma cells, and prolonged the survival of tumor bearing mice. Using the reactive oxygen species scavenger n-acetyl-cysteine these effects were in part reversible, suggesting that dihydroartemisinin partly acts through the generation of reactive oxygen species. PMID:27447560

  9. Slowing down glioblastoma progression in mice by running or the anti-malarial drug dihydroartemisinin? Induction of oxidative stress in murine glioblastoma therapy.

    PubMed

    Lemke, Dieter; Pledl, Hans-Werner; Zorn, Markus; Jugold, Manfred; Green, Ed; Blaes, Jonas; Löw, Sarah; Hertenstein, Anne; Ott, Martina; Sahm, Felix; Steffen, Ann-Catherine; Weiler, Markus; Winkler, Frank; Platten, Michael; Dong, Zhen; Wick, Wolfgang

    2016-08-30

    Influencing cancer metabolism by lifestyle changes is an attractive strategy as - if effective - exercise-induced problems may be less severe than those induced by classical anti-cancer therapies. Pursuing this idea, clinical trials evaluated the benefit of e.g. different diets such as the ketogenic diet, intermittent caloric restriction and physical exercise (PE) in the primary and secondary prevention of different cancer types. PE proved to be beneficial in the context of breast and colon cancer.Glioblastoma has a dismal prognosis, with an average overall survival of about one year despite maximal safe resection, concomitant radiochemotherapy with temozolomide followed by adjuvant temozolomide therapy. Here, we focused on the influence of PE as an isolated and adjuvant treatment in murine GB therapy.PE did not reduce toxic side effects of chemotherapy in mice administered in a dose escalating scheme as shown before for starvation. Although regular treadmill training on its own had no obvious beneficial effects, its combination with temozolomide was beneficial in the treatment of glioblastoma-bearing mice. As PE might partly act through the induction of reactive oxygen species, dihydroartemisinin - an approved anti-malarial drug which induces oxidative stress in glioma cells - was further evaluated in vitro and in vivo. Dihydroartemisinin showed anti-glioma activity by promoting autophagy, reduced the clonogenic survival and proliferation capacity of glioma cells, and prolonged the survival of tumor bearing mice. Using the reactive oxygen species scavenger n-acetyl-cysteine these effects were in part reversible, suggesting that dihydroartemisinin partly acts through the generation of reactive oxygen species.

  10. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report, Second quarter 1992

    SciTech Connect

    Not Available

    1992-08-24

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (No{sub x}) emissions from coal-fired boilers. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO{sub x} reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO{sub x} burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO{sub x} reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency.

  11. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report, third quarter 1991

    SciTech Connect

    Not Available

    1992-02-03

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO{sub x} reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an Advanced Overfire Air (AOFA) system followed by Low NO{sub x} Burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO{sub x} reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency.

  12. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report, Fourth quarter 1992

    SciTech Connect

    Not Available

    1992-12-31

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO{sub x} reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO{sub x} burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO{sub x } reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency. Baseline, AOFA, and LNB without AOFA test segments have been completed. Analysis of the 94 days of LNB tong-term data collected show the full load NO{sub x} emission levels to be approximately 0.65 lb/MBtu. Flyash LOI values for the LNB configuration are approximately 8 percent at full load. Corresponding values for the AOFA configuration are 0.94 lb/MBtu and approximately 10 percent. Abbreviated diagnostic tests for the LNB+AOFA configuration indicate that at 500 MWe, NO{sub x} emissions are approximately 0.55 lb/MBtu with corresponding flyash LOI values of approximately 11 percent. For comparison, the long-term, full load, baseline NO{sub x} emission level was approximately 1.24 lb/MBtu at 5.2 percent LOI. Comprehensive testing of the LNB+AOFA configuration will be performed when the stack particulate emissions issue is resolved.

  13. 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. Technical progress report, fourth quarter, 1994, October 1994--December 1994

    SciTech Connect

    1995-09-01

    This quarterly report discusses the technical progress of an innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NOx combustion equipment through the collection and analysis of long-term emissions data. The project provides a stepwise evaluation of the following NOx reduction technologies: Advanced overfire air (AOFA), Low NOx burners (LNB), LNB with AOFA, and Advanced Digital Controls and Optimization Strategies. The project has completed the baseline, AOFA, LNB, and LNB+AOFA test segments, fulfilling all testing originally proposed to DOE. Analysis of the LNB long-term data collected show the full load NOx emission levels to be near 0.65 lb/MBtu. This NOx level represents a 48 percent reduction when compared to the baseline, full load value of 1.24 lb/MBtu. These reductions were sustainable over the long-term test period and were consistent over the entire load range. Full load, fly ash LOI values in the LNB configuration were near 8 percent compared to 5 percent for baseline. Results from the LNB+AOFA phase indicate that full load NOx emissions are approximately 0.40 lb/MBtu with a corresponding fly ash LOI value of near 8 percent. Although this NOx level represents a 67 percent reduction from baseline levels, a substantial portion of the incremental change in NOx emissions between the LNB and LNB+AOFA configurations was the result of operational changes and not the result of the AOFA system. Phase 4 of the project is now underway.

  14. Progression of hypertension and kidney disease in aging fawn-hooded rats is mediated by enhanced influence of renin-angiotensin system and suppression of nitric oxide system and epoxyeicosanoids.

    PubMed

    Doleželová, Šárka; Jíchová, Šárka; Husková, Zuzana; Vojtíšková, Alžběta; Kujal, Petr; Hošková, Lenka; Kautzner, Josef; Sadowski, Janusz; Červenka, Luděk; Kopkan, Libor

    The fawn-hooded hypertensive (FHH) rat serves as a genetic model of spontaneous hypertension associated with glomerular hyperfiltration and proteinuria. However, the knowledge of the natural course of hypertension and kidney disease in FHH rats remains fragmentary and the underlying pathophysiological mechanisms are unclear. In this study, over the animals' lifetime, we followed the survival rate, blood pressure (telemetry), indices of kidney damage, the activity of renin-angiotensin (RAS) and nitric oxide (NO) systems, and CYP450-epoxygenase products (EETs). Compared to normotensive controls, no elevation of plasma and renal RAS was observed in prehypertensive and hypertensive FHH rats; however, RAS inhibition significantly reduced systolic blood pressure (137 ± 9 to 116 ± 8, and 159 ± 8 to 126 ± 4 mmHg, respectively) and proteinuria (62 ± 2 to 37 ± 3, and 132 ± 8 to 87 ± 5 mg/day, respectively). Moreover, pharmacological RAS inhibition reduced angiotensin (ANG) II and increased ANG 1-7 in the kidney and thereby may have delayed the progression of kidney disease. Furthermore, renal NO and EETs declined in the aging FHH rats but not in the control strain. The present results, especially the demonstration of exaggerated vascular responsiveness to ANG II, indicate that RAS may contribute to the development of hypertension and kidney disease in FHH rats. The activity of factors opposing the development of hypertension and protecting the kidney declined with age in this model. Therefore, therapeutic enhancement of this activity besides RAS inhibition could be attempted in the therapy of human hypertension associated with kidney disease.

  15. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Third quarterly technical progress report

    SciTech Connect

    Not Available

    1993-12-31

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO{sub x} burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO{sub x} reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency. Baseline, AOFA, LNB, and LNB plus AOFA test segments have been completed. Analysis of the 94 days of LNB long-term data collected show the full-load NO{sub x} emission levels to be approximately 0.65 lb/MBtu with fly ash LOI values of approximately 8 percent. Corresponding values for the AOFA configuration are 0.94 lb/MBtu and approximately 10 percent. For comparison, the long-term full-load, baseline NO{sub x} emission level was approximately 1.24 lb/MBtu at 5.2 percent LOI. Comprehensive testing in the LNB+AOFA configuration indicate that at full-load, NO{sub x} emissions and fly ash LOI are near 0.40 lb/MBtu and 8 percent, respectively. However, it is believed that a substantial portion of the incremental change in NO{sub x} emissions between the LNB and LNB+AOFA configurations is the result of additional burner tuning and other operational adjustments and is not the result of the AOFA system. During this quarter, LNB+AOFA testing was concluded. Testing performed during this quarter included long-term and verification testing in the LNB+AOFA configuration.

  16. Annual Technical Progress Report

    SciTech Connect

    Ayman I. Hawari

    2002-10-02

    This report describes the results generated during phase 1 of this project. During this phase, the main tools that are used to compute the thermal neutron scattering kernels for graphite, beryllium, beryllium oxide, zirconium hydride, light water, polyethylene were implemented and tested. This includes a modified NJOY/LEAPR code system, the GASKET code, and the ab initio condensed matter codes VASP and PHONON. Thermal neutron scattering kernels were generated for graphite, beryllium, beryllium oxide. In the case of graphite, new phonon spectra were examined. The first is a spectrum based on experiments performed at Oak Ridge National Laboratory in the early seventies, and the second is generated using the ab initio methods. In the case of beryllium, and beryllium oxide, a synthetic approach for generating the phonon spectra was implemented. In addition, significant progress was made on an experiment to benchmark the graphite scattering kernels was made. The simulations of this experiment show that differences on the order of a few percent, in Pu-239 detector responses, can be expected due to the use of different scattering kernels. (B204) NOT A FINAL REPORT

  17. Oxidative DNA modifications.

    PubMed

    Poulsen, Henrik E

    2005-07-01

    the separation procedure proper prior to detection. A large effort from 20+ laboratories supported by a grant from the EU has reduced artifacts considerably and work towards interlaboratory standardization of the methodology is in progress. The presently agreed "normal" levels of the most frequent known lesion 8-oxodG is about 5 per million dG's in DNA. A comprehensive evaluation of the evidence, from chemistry to clinical and epidemiological trials, linking oxidative modifications to cancer will be given. Finally, an estimate of the quantitative role oxidative DNA modifications play among the multiplicity of other insults is given. While there is no question that all of these oxidative mechanisms do exist, quantitative data on their importance for the human situation do not exist. Prospective human studies that can provide such quantitative data on different mechanisms are underway.

  18. Enzymes of respiratory iron oxidation

    SciTech Connect

    Blake, R. II.

    1991-01-01

    This report focuses on the progress made in three areas of research concerned with enzymes involved in respiratory iron oxidation. The three areas are as follows: development of an improved procedure for the routine large scale culture of iron oxidizing chemolithotrophs based on the in-situ electrolysis of the soluble iron in the growth medium; to perform iron oxidation kinetic studies on whole cells using the oxygen electrode; and to identify, separate, purify, and characterize the individual cellular components.

  19. EDITORIAL: Catalysing progress Catalysing progress

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2010-01-01

    Examples of the merits of blue-sky research in the history of science are legion. The invention of the laser, celebrating its 50th anniversary this year, is an excellent example. When it was invented it was considered to be 'a solution waiting for a problem', and yet the level to which it has now infiltrated our day-to-day technological landscape speaks volumes. At the same time it is also true to say that the direction of research is also at times rightly influenced by the needs and concerns of the general public. Over recent years, growing concerns about the environment have had a noticeable effect on research in nanotechnology, motivating work on a range of topics from green nanomaterial synthesis [1] to high-efficiency solar cells [2] and hydrogen storage [3]. The impact of the world's energy consumption on the welfare of the planet is now an enduring and well founded concern. In the face of an instinctive reluctance to curtail habits of comfort and convenience and the appendages of culture and consumerism, research into renewable and more efficient energy sources seem an encouraging approach to alleviating an impending energy crisis. Fuel cells present one alternative to traditional combustion cells that have huge benefits in terms of the efficiency of energy conversion and the limited harmful emissions. In last week's issue of Nanotechnology, Chuan-Jian Zhong and colleagues at the State University of New York at Binghamton in the USA presented an overview of research on nanostructured catalysts in fuel cells [4]. The topical review includes insights into the interactions between nanoparticles and between nanoparticles and their substrate as well as control over the composition and nanostructure of catalysts. The review also serves to highlight how the flourishing of nanotechnology research has heralded great progress in the exploitation of catalysts with nanostructures ingeniously controlled to maximize surface area and optimize energetics for synthesis

  20. Primary Progressive Aphasia

    MedlinePlus

    Primary progressive aphasia Overview By Mayo Clinic Staff Primary progressive aphasia (uh-FAY-zhuh) is a rare nervous system (neurological) syndrome ... your ability to communicate. People with primary progressive aphasia can have trouble expressing their thoughts and understanding ...

  1. Oxidative stress and chronic kidney disease.

    PubMed

    Brown, Scott A

    2008-01-01

    Slowing the rate of progression of chronic kidney disease (CKD) is a critical part of the management of affected dogs and cats. Renal oxidant stress is a previously unrecognized factor in the progression of canine CKD and is likely to be similarly important in feline CKD. Renin-angiotensin antagonism, calcium channel antagonism, n-3 polyunsaturated fatty acid, and antihypertensive and antiproteinuric therapy are commonly recommended for dogs and cats with CKD. These therapies would be expected to reduce renal oxidant stress by decreasing reactive oxygen species generation. Newer data indicate that dietary supplementation with specific antioxidants is an important consideration for limiting renal oxidant stress and progression of CKD.

  2. Protein oxidation in Huntington disease.

    PubMed

    Sorolla, M Alba; Rodríguez-Colman, María José; Vall-llaura, Núria; Tamarit, Jordi; Ros, Joaquim; Cabiscol, Elisa

    2012-01-01

    Huntington disease (HD) is an inherited neurodegenerative disorder caused by expansion of CAG repeats in the huntingtin gene, affecting initially the striatum and progressively the cortex. Oxidative stress, and consequent protein oxidation, has been described as important to disease progression. This review focuses on recent advances in the field, with a particular emphasis on the identified target proteins and the role that their oxidation has or might have in the pathophysiology of HD. Oxidation and the resulting inactivation and/or degradation of important proteins can explain the impairment of several metabolic pathways in HD. Oxidation of enzymes involved in ATP synthesis can account for the energy deficiency observed. Impairment of protein folding and degradation can be due to oxidation of several heat shock proteins and Valosin-containing protein. Oxidation of two enzymes involved in the vitamin B6 metabolism could result in decreased availability of pyridoxal phosphate, which is a necessary cofactor in transaminations, the kynurenine pathway and the synthesis of glutathione, GABA, dopamine and serotonin, all of which have a key role in HD pathology. In addition, protein oxidation often contributes to oxidative stress, aggravating the molecular damage inside the cell. Copyright © 2012 International Union of Biochemistry and Molecular Biology, Inc.

  3. PREFACE: Semiconducting oxides Semiconducting oxides

    NASA Astrophysics Data System (ADS)

    Catlow, Richard; Walsh, Aron

    2011-08-01

    their help in producing this special section. We hope that it conveys some of the excitement and significance of the field. Semiconducting oxides contents Chemical bonding in copper-based transparent conducting oxides: CuMO2 (M = In, Ga, Sc) K G Godinho, B J Morgan, J P Allen, D O Scanlon and G W Watson Electrical properties of (Ba, Sr)TiO3 thin films with Pt and ITO electrodes: dielectric and rectifying behaviourShunyi Li, Cosmina Ghinea, Thorsten J M Bayer, Markus Motzko, Robert Schafranek and Andreas Klein Orientation dependent ionization potential of In2O3: a natural source for inhomogeneous barrier formation at electrode interfaces in organic electronicsMareike V Hohmann, Péter Ágoston, André Wachau, Thorsten J M Bayer, Joachim Brötz, Karsten Albe and Andreas Klein Cathodoluminescence studies of electron irradiation effects in n-type ZnOCasey Schwarz, Yuqing Lin, Max Shathkin, Elena Flitsiyan and Leonid Chernyak Resonant Raman scattering in ZnO:Mn and ZnO:Mn:Al thin films grown by RF sputteringM F Cerqueira, M I Vasilevskiy, F Oliveira, A G Rolo, T Viseu, J Ayres de Campos, E Alves and R Correia Structure and electrical properties of nanoparticulate tungsten oxide prepared by microwave plasma synthesisM Sagmeister, M Postl, U Brossmann, E J W List, A Klug, I Letofsky-Papst, D V Szabó and R Würschum Charge compensation in trivalent cation doped bulk rutile TiO2Anna Iwaszuk and Michael Nolan Deep level transient spectroscopy studies of n-type ZnO single crystals grown by different techniquesL Scheffler, Vl Kolkovsky, E V Lavrov and J Weber Microstructural and conductivity changes induced by annealing of ZnO:B thin films deposited by chemical vapour depositionC David, T Girardeau, F Paumier, D Eyidi, B Lacroix, N Papathanasiou, B P Tinkham, P Guérin and M Marteau Multi-component transparent conducting oxides: progress in materials modellingAron Walsh, Juarez L F Da Silva and Su-Huai Wei Thickness dependence of the strain, band gap and transport properties of

  4. Arithmetic Progressions on Conics.

    PubMed

    Ciss, Abdoul Aziz; Moody, Dustin

    2017-01-01

    In this paper, we look at long arithmetic progressions on conics. By an arithmetic progression on a curve, we mean the existence of rational points on the curve whose x-coordinates are in arithmetic progression. We revisit arithmetic progressions on the unit circle, constructing 3-term progressions of points in the first quadrant containing an arbitrary rational point on the unit circle. We also provide infinite families of three term progressions on the unit hyperbola, as well as conics ax(2) + cy(2) = 1 containing arithmetic progressions as long as 8 terms.

  5. Enzymes of respiratory iron oxidation

    SciTech Connect

    Blake, R. II.

    1992-01-01

    This report describes experimental progress in characterizing and identifying redox proteins in a number of iron-oxidizing bacteria. Sections of the paper are entitled (1) In Situ electrolysis was explored to achieve enhanced yields of iron-oxidizing bacteria, (2)Structure/function studies were performed on redox-active biomolecules from Thiobacillus ferrooxidans, (3) Novel redox-active biomolecules were demonstrated in other iron autotrophs, and (4) New probes of metalloprotein electron-transfer reactions were synthesized and characterized.

  6. Innovative Clean Coal Technology (ICCT). Demonstration of Selective Catalytic Reduction (SCR) technology for the control of Nitrogen Oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Technical progress report, third and fourth quarters 1995

    SciTech Connect

    1996-05-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from U.S., Japanese, and European catalyst suppliers on a high-sulfur U.S. coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor.

  7. Mitochondrial dysfunctions during progression of dystrophic cardiomyopathy.

    PubMed

    Kyrychenko, Victoria; Poláková, Eva; Janíček, Radoslav; Shirokova, Natalia

    2015-08-01

    Duchenne muscular dystrophy (DMD) is a progressive muscle disease with severe cardiac complications. It is believed that cellular oxidative stress and augmented Ca(2+) signaling drives the development of cardiac pathology. Some mitochondrial and metabolic dysfunctions have also been reported. Here we investigate cellular mechanisms responsible for impaired mitochondrial metabolism in dystrophic cardiomyopathy at early stages of the disease. We employed electrophysiological and imaging techniques to study mitochondrial structure and function in cardiomyocytes from mdx mice, an animal model of DMD. Here we show that mitochondrial matrix was progressively oxidized in myocytes isolated from mdx mice. Moreover, an abrupt increase in workload resulted in significantly more pronounced oxidation of mitochondria in dystrophic cells. Electron micrographs revealed a gradually increased number of damaged mitochondria in mdx myocytes. Degradation in mitochondrial structure was correlated with progressive increase in mitochondrial Ca(2+) sequestration and mitochondrial depolarization, despite a substantial and persistent elevation in resting cytosolic sodium levels. Treatment of mdx cells with cyclosporine A, an inhibitor of mitochondrial permeability transition pore (mPTP), shifted both resting and workload-dependent mitochondrial redox state to the levels recorded in control myocytes. It also significantly reduced workload dependent depolarization of mitochondrial membrane in dystrophic cardiomyocytes. Overall, our studies highlight age dependent deterioration of mitochondrial function in dystrophic cardiomyocytes, which seems to be associated with excessive opening of mPTP due to oxidative stress and cellular Ca(2+) overload.

  8. Reconstructing Progressive Education

    ERIC Educational Resources Information Center

    Kaplan, Andy

    2013-01-01

    The work of Colonel Francis W. Parker, the man whom Dewey called "the father of progressive education," provides a starting point for reconstructing the loose ambiguities of progressive education into a coherent social and educational philosophy. Although progressives have claimed their approach is more humane and sensitive to children, we need…

  9. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Technical progress report: First quarter 1993

    SciTech Connect

    Not Available

    1993-12-31

    This quarterly report discusses the technical progress of an Innovative Clean Coal Technology (ICCT) demonstration being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. A target of achieving fifty percent NO{sub x} reduction using combustion modifications has been established for the project. The project provides a stepwise retrofit of an advanced overfire air (AOFA) system followed by low NO{sub x} burners (LNB). During each test phase of the project, diagnostic, performance, long-term, and verification testing will be performed. These tests are used to quantify the NO{sub x} reductions of each technology and evaluate the effects of those reductions on other combustion parameters such as particulate characteristics and boiler efficiency. During this quarter, long-term testing of the LNB + AOFA configuration continued and no parametric testing was performed. Further full-load optimization of the LNB + AOFA system began on March 30, 1993. Following completion of this optimization, comprehensive testing in this configuration will be performed including diagnostic, performance, verification, long-term, and chemical emissions testing. These tests are scheduled to start in May 1993 and continue through August 1993. Preliminary engineering and procurement are progressing on the Advanced Low NOx Digital Controls scope addition to the wall-fired project. The primary activities during this quarter include (1) refinement of the input/output lists, (2) procurement of the distributed digital control system, (3) configuration training, and (4) revision of schedule to accommodate project approval cycle and change in unit outage dates.

  10. Innovative Clean Coal Technology (ICCT): 500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Quarterly technical progress report, [July--September 1995

    SciTech Connect

    1995-12-31

    This project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 located near Rome, Georgia. The primary goal of this project is the characterization of the low NO{sub x} combustion equipment through the collection and analysis of long-term emissions data. The project provides a stepwise evaluation of the following NO{sub x} reduction technologies: Advanced overfire air (AOFA), Low NO{sub x} burners (LNB), LNB with AOFA, and advanced digital controls and optimization strategies. The project has completed the baseline, AOFA, LNB, and LNB+AOFA test segments, fulfilling all testing originally proposed to DOE. Phase 4 of the project, demonstration of advanced control/optimization methodologies for NO{sub x} abatement, is now in progress. The methodology selected for demonstration at Hammond Unit 4 is the Generic NO{sub x} Control Intelligent System (GNOCIS), which is being developed by a consortium consisting of the Electric Power Research Institute, PowerGen, Southern Company, Radian Corporation, U.K. Department of Trade and Industry, and U.S. Department of Energy. GNOCIS is a methodology that can result in improved boiler efficiency and reduced NO{sub x} emissions from fossil fuel fired boilers. Using a numerical model of the combustion process, GNOCIS applies an optimizing procedure to identify the best set points for the plant on a continuous basis. GNOCIS is in progress at Alabama Power`s Gaston Unit 4 and PowerGen`s Kingsnorth Unit 1. The first commercial demonstration of GNOCIS will be at Hammond 4.

  11. Effect of inhomogeneous re-oxidation on Ni-based SOFC oxidation resistance

    NASA Astrophysics Data System (ADS)

    Lou, Kang; Wang, Feng Hui; Lu, Yong Jun; Zhao, Xiang

    2016-09-01

    Inhomogeneous re-oxidation, which causes graded NiO content along anode thickness, has been confirmed to be a key reason for Ni-based cell cracking during redox progress. In this paper, an analytical model is developed to estimate the impact of inhomogeneous re-oxidation on Ni-based solid oxide fuel cell (SOFC) oxidation resistance. And experiments, in which the SOFC was partially re-oxidized, were implemented for model trial. Model results show that electrolyte internal stress can be significantly reduced (from 367 MPa to 135 MPa, when the oxidation degree is 60%), and the electrolyte can remain intact even when the oxidation degree reaches about 70%, if the anode was re-oxidized uniformly. This impact of inhomogeneous re-oxidation on stress in the electrolyte decreases as the anode thickness increases. Scanning electron microscopic (SEM) images of partially oxidized anode cross-sections confirmed that Ni oxidation was inhomogeneous, in which the outer regions of the anode became almost fully oxidized, while the inner regions remained metallic. And the inhomogeneity increases with the redox times. Consequently, it is important to avoid gradients in NiO content during oxidation progress to prevent cell cracking.

  12. [Nitric oxide].

    PubMed

    Rovira, I

    1995-01-01

    Nitric oxide was identified as the relaxing factor derived from the endothelium in 1987. Nitric oxide synthesis allows the vascular system to maintain a state of vasodilation, thereby regulating arterial pressure. Nitric oxide is also found in platelets, where it inhibits adhesion and aggregation; in the immune system, where it is responsible for the cytotoxic action of macrophages; and in the nervous system, where it acts as neurotransmitter. A deficit in endogenous synthesis of nitric oxide contributes to such conditions as essential arterial hypertension, pulmonary hypertension and heart disease. An excess of nitrous oxide induced by endotoxins and cytokinins, meanwhile, is believed to be responsible for hypotension in septic shock and for hyperdynamic circulatory state in cirrhosis of the liver. Nitric oxide has also been implicated in the rejection of transplanted organs and in cell damage after reperfusion. Inhaled nitrous oxide gas reduces pulmonary hypertension without triggering systemic hypotension in both experimental and clinical conditions. It also produces selective vasodilation when used to ventilate specific pulmonary areas, thereby improving the ventilation/perfusion ratio and, hence, oxygenation. Nitric oxide inhalation is effective in pulmonary hypertension-coincident with chronic obstructive lung disease, in persistent neonatal pulmonary hypertension and in pulmonary hypertension with congenital or acquired heart disease. Likewise, it reduces intrapulmonary shunt in acute respiratory failure and improves gas exchange. Under experimental conditions nitric oxide acts as a bronchodilator, although it seems to be less effective for this purpose in clinical use.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Chemical design of biocompatible iron oxide nanoparticles for medical applications.

    PubMed

    Ling, Daishun; Hyeon, Taeghwan

    2013-05-27

    Iron oxide nanoparticles are one of the most versatile and safe nanomaterials used in medicine. Recent progress in nanochemistry enables fine control of the size, crystallinity, uniformity, and surface properties of iron oxide nanoparticles. In this review, the synthesis of chemically designed biocompatible iron oxide nanoparticles with improved quality and reduced toxicity is discussed for use in diverse biomedical applications.

  14. Neutronic Benchmarks for the Utilization of Mixed-Oxide Fuel: Joint U.S./Russian Progress Report for Fiscal Year 1997 - Volume 4, Part 2--Saxton Plutonium Program Critical Experiments

    SciTech Connect

    Abdurrahman, NM

    2000-10-12

    Critical experiments with water-moderated, single-region PuO{sub 2}-UO{sub 2} or UO{sub 2}, and multiple-region PuO{sub 2}-UO{sub 2}- and UO{sub 2}-fueled cores were performed at the CRX reactor critical facility at the Westinghouse Reactor Evaluation Center (WREC) at Waltz Mill, Pennsylvania in 1965 [1]. These critical experiments were part of the Saxton Plutonium Program. The mixed oxide (MOX) fuel used in these critical experiments and then loaded in the Saxton reactor contained 6.6 wt% PuO{sub 2} in a mixture of PuO{sub 2} and natural UO{sub 2}. The Pu metal had the following isotopic mass percentages: 90.50% {sup 239}Pu; 8.57% {sup 239}Pu; 0.89% {sup 240}Pu; and 0.04% {sup 241}Pu. The purpose of these critical experiments was to verify the nuclear design of Saxton partial plutonium cores while obtaining parameters of fundamental significance such as buckling, control rod worth, soluble poison worth, flux, power peaking, relative pin power, and power sharing factors of MOX and UO{sub 2} lattices. For comparison purposes, the core was also loaded with uranium dioxide fuel rods only. This series is covered by experiments beginning with the designation SX.

  15. Innovative clean coal technology (ICCT): Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Fourth quarterly progress report

    SciTech Connect

    1992-12-31

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe, there are numerous technical uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuels; (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}; and (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur US coal.

  16. Role of mitochondrial dysfunction in cancer progression

    PubMed Central

    Hsu, Chia-Chi; Tseng, Ling-Ming

    2016-01-01

    Deregulated cellular energetics was one of the cancer hallmarks. Several underlying mechanisms of deregulated cellular energetics are associated with mitochondrial dysfunction caused by mitochondrial DNA mutations, mitochondrial enzyme defects, or altered oncogenes/tumor suppressors. In this review, we summarize the current understanding about the role of mitochondrial dysfunction in cancer progression. Point mutations and copy number changes are the two most common mitochondrial DNA alterations in cancers, and mitochondrial dysfunction induced by chemical depletion of mitochondrial DNA or impairment of mitochondrial respiratory chain in cancer cells promotes cancer progression to a chemoresistance or invasive phenotype. Moreover, defects in mitochondrial enzymes, such as succinate dehydrogenase, fumarate hydratase, and isocitrate dehydrogenase, are associated with both familial and sporadic forms of cancer. Deregulated mitochondrial deacetylase sirtuin 3 might modulate cancer progression by regulating cellular metabolism and oxidative stress. These mitochondrial defects during oncogenesis and tumor progression activate cytosolic signaling pathways that ultimately alter nuclear gene expression, a process called retrograde signaling. Changes in the intracellular level of reactive oxygen species, Ca2+, or oncometabolites are important in the mitochondrial retrograde signaling for neoplastic transformation and cancer progression. In addition, altered oncogenes/tumor suppressors including hypoxia-inducible factor 1 and tumor suppressor p53 regulate mitochondrial respiration and cellular metabolism by modulating the expression of their target genes. We thus suggest that mitochondrial dysfunction plays a critical role in cancer progression and that targeting mitochondrial alterations and mitochondrial retrograde signaling might be a promising strategy for the development of selective anticancer therapy. PMID:27022139

  17. Enzymatic Oxidation of Methane

    SciTech Connect

    Sirajuddin, S; Rosenzweig, AC

    2015-04-14

    Methane monooxygenases (MMOs) are enzymes that catalyze the oxidation of methane to methanol in methanotrophic bacteria. As potential targets for new gas-to-liquid methane bioconversion processes, MMOs have attracted intense attention in recent years. There are two distinct types of MMO, a soluble, cytoplasmic MMO (sMMO) and a membrane-bound, particulate MMO (pMMO). Both oxidize methane at metal centers within a complex, multisubunit scaffold, but the structures, active sites, and chemical mechanisms are completely different. This Current Topic review article focuses on the overall architectures, active site structures, substrate reactivities, proteinprotein interactions, and chemical mechanisms of both MMOs, with an emphasis on fundamental aspects. In addition, recent advances, including new details of interactions between the sMMO components, characterization of sMMO intermediates, and progress toward understanding the pMMO metal centers are highlighted. The work summarized here provides a guide for those interested in exploiting MMOs for biotechnological applications.

  18. Innovative Clean Coal Technology (ICCT): Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Third quarterly technical progress report 1992

    SciTech Connect

    Not Available

    1992-11-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe on gas-, oil-, and low-sulfur, coal-fired boilers, there are several technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuels. (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3} and (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small- scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high-sulfur US coal. The demonstration will be performed at Gulf Power Company`s Plant Crist Unit No. 5 (75 MW capacity) near Pensacola, Florida.

  19. Innovative Clean Coal Technology (ICCT): Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Technical progress report, third and fourth quarters 1994

    SciTech Connect

    1995-11-01

    The objective of this project is to demonstrate and evaluate commercially available selective catalytic reduction (SCR) catalysts from U.S., Japanese, and European catalyst suppliers on a high-sulfur U.S. Coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to form nitrogen and water vapor. Although SCR is widely practiced in Japan and European gas-, oil-, and low-sulfur coal-fired boilers, there are several technical uncertainties associated with applying SCR to U.S. coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in U.S. coals that are not present in other fuels; (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}; performance of a wide variety of SCR catalyst compositions, geometries, and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties are being explored by operating a series of small- scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur U.S. coal. The demonstration is being performed at Gulf Power Company`s Plant Crist Unit No. 5 (75 MW capacity) near Pensacola, Florida. The project is funded by the U.S. Department of Energy (DOE), Southern Company Services, Inc. (SCS on behalf of the entire Southern electric system), the Electric Power Research Institute (EPRI), and Ontario Hydro. SCS is the participant responsible for managing al aspects of this project. 1 ref., 69 figs., 45 tabs.

  20. Demonstration of Selective Catalytic Reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Technical progress report, first and second quarters 1994

    SciTech Connect

    1995-11-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from U.S., Japanese and European catalyst suppliers on a high-sulfur U.S. coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involve injecting ammonia into the flue gas generated from coal combustion in a boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to form nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe on gas-, oil-, and low-sulfur coal-fired boilers, there are several technical uncertainties associated with applying SCR to U.S. coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in U.S. coals that are not present in other fuels; (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}; and (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties are being explored by operating a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur U.S. coal. The project is being conducted in the following three phases: permitting, environmental monitoring plan and preliminary engineering; detailed design engineering and construction; and operation, testing, disposition and final report. The project was in the operation and testing phase during this reporting period. Accomplishments for this period are described.

  1. Innovative Clean Coal Technology (ICCT): Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO{sub x}) emissions from high-sulfur coal-fired boilers. Technical progress report, October 1993--December 1993

    SciTech Connect

    1995-06-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from U.S., Japanese and European catalyst suppliers on a high-sulfur U.S. coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe on gas-, oil-, and low-sulfur coal-fired boilers, there are several technical uncertainties associated with applying SCR to U.S. coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in U.S. coals that are not present in other fuels; (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}; and (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties are being explored by operating a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur U.S. coal.

  2. A perspective on chronic kidney disease progression.

    PubMed

    Zhong, Jianyong; Yang, Hai-Chun; Fogo, Agnes B

    2017-03-01

    Chronic kidney disease (CKD) will progress to end stage without treatment, but the decline of renal function may not be linear. Compared with glomerular filtration rate and proteinuria, new surrogate markers, such as kidney injury molecule-1, neutrophil gelatinase-associated protein, apolipoprotein A-IV, and soluble urokinase receptor, may allow potential intervention and treatment in the earlier stages of CKD, which could be useful for clinical trials. New omic-based technologies reveal potential new genomic and epigenomic mechanisms that appear different from those causing the initial disease. Various clinical studies also suggest that acute kidney injury is a major risk for progressive CKD. To ameliorate the progression of CKD, the first step is optimizing renin-angiotensin-aldosterone system blockade. New drugs targeting endothelin, transforming growth factor-β, oxidative stress, and inflammatory- and cell-based regenerative therapy may have add-on benefit. Copyright © 2017 the American Physiological Society.

  3. Progress in BazookaSPECT.

    PubMed

    Miller, Brian W; Barber, H Bradford; Furenlid, Lars R; Moore, Stephen K; Barrett, Harrison H

    2009-01-01

    Recent progress on a high-resolution, photon-counting gamma-ray and x-ray imager called BazookaSPECT is presented. BazookaSPECT is an example of a new class of scintillation detectors based on integrating detectors such as CCD(charge-coupled device) or CMOS(complementary metal-oxide semiconductor) sensors. BazookaSPECT is unique in that it makes use of a scintillator in close proximity to a microchannel plate-based image intensifier for up-front optical amplification of scintillation light. We discuss progress made in bringing about compact BazookaSPECT modules and in real-time processing of event data using graphics processing units (GPUs). These advances are being implemented in the design of a high-resolution rodent brain imager called FastSPECT III. A key benefit of up-front optical gain is that any CCD/CMOS sensor can now be utilized for photon counting. We discuss the benefits and feasibility of using CMOS sensors as photon-counting detectors for digital radiography, with application in mammography and computed tomography (CT). We present as an appendix a formal method for comparing various photon-counting integrating detectors using objective statistical criteria.

  4. Progress in BazookaSPECT

    PubMed Central

    Miller, Brian W.; Barber, H. Bradford; Furenlid, Lars R.; Moore, Stephen K.; Barrett, Harrison H.

    2010-01-01

    Recent progress on a high-resolution, photon-counting gamma-ray and x-ray imager called BazookaSPECT is presented. BazookaSPECT is an example of a new class of scintillation detectors based on integrating detectors such as CCD(charge-coupled device) or CMOS(complementary metal-oxide semiconductor) sensors. BazookaSPECT is unique in that it makes use of a scintillator in close proximity to a microchannel plate-based image intensifier for up-front optical amplification of scintillation light. We discuss progress made in bringing about compact BazookaSPECT modules and in real-time processing of event data using graphics processing units (GPUs). These advances are being implemented in the design of a high-resolution rodent brain imager called FastSPECT III. A key benefit of up-front optical gain is that any CCD/CMOS sensor can now be utilized for photon counting. We discuss the benefits and feasibility of using CMOS sensors as photon-counting detectors for digital radiography, with application in mammography and computed tomography (CT). We present as an appendix a formal method for comparing various photon-counting integrating detectors using objective statistical criteria. PMID:21297897

  5. Progressive dysembryoplastic neuroepithelial tumour.

    PubMed

    Alexander, Hamish; Tannenburg, Anthony; Walker, David G; Coyne, Terry

    2015-01-01

    Dysembryoplastic neuroepithelial tumour (DNET) is a benign tumour characterised by cortical location and presentation with drug resistant partial seizures in children. Recently the potential for malignant transformation has been reported, however progression without malignant transformation remains rare. We report a case of clinical and radiologic progression of a DNET in a girl 10 years after initial biopsy.

  6. Interface-confined oxide nanostructures for catalytic oxidation reactions.

    PubMed

    Fu, Qiang; Yang, Fan; Bao, Xinhe

    2013-08-20

    review our recent progress on oxide-on-metal inverse catalysts, mainly the TMO-on-Pt (TM = Fe, Co, and Ni) systems and discuss the interface-confinement effect, an important factor in the behavior of these catalytic systems. We have studied both model catalyst systems and real supported nanocatalysts. Surface science studies and density functional theory calculations in model systems illustrate the importance of the oxide-metal interfaces in the creation and stabilization of surface active centers, and reveal the reaction mechanism at these active sites. In real catalysts, we describe facile preparation processes for fabricating the oxide-on-metal nanostructures. We have demonstrated excellent performance of the inverse catalysts in oxidation reactions such as CO oxidation. We believe that the interface confinement effect can be employed to design highly efficient novel catalysts and that the inverse oxide-on-metal catalysts may find wide applications in heterogeneous catalysis.

  7. Rapidly Progressive Dementia

    PubMed Central

    Geschwind, Michael D.; Shu, Huidy; Haman, Aissa; Sejvar, James J.; Miller, Bruce L.

    2009-01-01

    In contrast with more common dementing conditions that typically develop over years, rapidly progressive dementias can develop subacutely over months, weeks, or even days and be quickly fatal. Because many rapidly progressive dementias are treatable, it is paramount to evaluate and diagnose these patients quickly. This review summarizes recent advances in the understanding of the major categories of RPD and outlines efficient approaches to the diagnosis of the various neurodegenerative, toxic-metabolic, infectious, autoimmune, neoplastic, and other conditions that may progress rapidly. PMID:18668637

  8. Waste management progress report

    SciTech Connect

    1997-06-01

    During the Cold War era, when DOE and its predecessor agencies produced nuclear weapons and components, and conducted nuclear research, a variety of wastes were generated (both radioactive and hazardous). DOE now has the task of managing these wastes so that they are not a threat to human health and the environment. This document is the Waste Management Progress Report for the U.S. Department of Energy dated June 1997. This progress report contains a radioactive and hazardous waste inventory and waste management program mission, a section describing progress toward mission completion, mid-year 1997 accomplishments, and the future outlook for waste management.

  9. Rapidly progressive Alzheimer disease.

    PubMed

    Schmidt, Christian; Wolff, Martin; Weitz, Michael; Bartlau, Thomas; Korth, Carsten; Zerr, Inga

    2011-09-01

    Different rates of progression have been observed among patients with Alzheimer disease. Risk factors that accelerate deterioration have been identified and some are being discussed, such as genetics, comorbidity, and the early appearance of Alzheimer disease motor signs. Progressive forms of Alzheimer disease have been reported with rapid cognitive decline and disease duration of only a few years. This short review aims to provide an overview of the current knowledge of rapidly progressive Alzheimer disease. Furthermore, we suggest that rapid, in this context, should be defined as a Mini-Mental State Examination score decrease of 6 points per year.

  10. Progress Resupply Vehicle approach

    NASA Image and Video Library

    2012-01-27

    ISS030-E-050883 (27 Jan. 2012) --- Russian cosmonaut Anton Shkaplerov (bottom), Expedition 30 flight engineer, monitors data at the manual TORU docking system controls in the Zvezda Service Module of the International Space Station during approach and docking operations of the unpiloted ISS Progress 46 resupply vehicle. Progress 46 docked automatically to the Pirs Docking Compartment via the Kurs automated rendezvous system at 7:00 p.m. (EST) on Jan. 27, 2012. NASA astronaut Dan Burbank, commander, looks on. Russian cosmonaut Anatoly Ivanishin (bottom background), flight engineer, photographs the approach of the Progress from a Zvezda window.

  11. Progress Resupply Vehicle approach

    NASA Image and Video Library

    2012-01-27

    ISS030-E-050885 (27 Jan. 2012) --- Russian cosmonauts Anton Shkaplerov (bottom) and Oleg Kononenko (center), both Expedition 30 flight engineers, monitor data at the manual TORU docking system controls in the Zvezda Service Module of the International Space Station during approach and docking operations of the unpiloted ISS Progress 46 resupply vehicle. Progress 46 docked automatically to the Pirs Docking Compartment via the Kurs automated rendezvous system at 7:00 p.m. (EST) on Jan. 27, 2012. NASA astronaut Dan Burbank, commander, looks on. Russian cosmonaut Anatoly Ivanishin (bottom background), flight engineer, photographs the approach of the Progress from a Zvezda window.

  12. Progress Resupply Vehicle approach

    NASA Image and Video Library

    2012-01-27

    ISS030-E-050884 (27 Jan. 2012) --- Russian cosmonaut Anton Shkaplerov (bottom), Expedition 30 flight engineer, monitors data at the manual TORU docking system controls in the Zvezda Service Module of the International Space Station during approach and docking operations of the unpiloted ISS Progress 46 resupply vehicle. Progress 46 docked automatically to the Pirs Docking Compartment via the Kurs automated rendezvous system at 7:00 p.m. (EST) on Jan. 27, 2012. NASA astronaut Dan Burbank, commander, looks on. Russian cosmonaut Anatoly Ivanishin (bottom background), flight engineer, photographs the approach of the Progress from a Zvezda window.

  13. Studies of reaction geometry in oxidation and reduction of the alkaline silver electrode

    NASA Technical Reports Server (NTRS)

    Butler, E. A.; Blackham, A. U.

    1971-01-01

    Two methods of surface area estimations of sintered silver electrodes have given roughness factors of 58 and 81. One method is based on constant current oxidation, the other is based on potentiostatic oxidation. Examination of both wire and sintered silver electrodes via scanning electron microscopy at various stages of oxidation have shown that important structural features are mounds of oxide. In potentiostatic oxidations these appear to form on sites instantaneously nucleated while in constant current oxidations progressive nucleation is indicated.

  14. Oxidative Stress in Atopic Dermatitis

    PubMed Central

    Ji, Hongxiu; Li, Xiao-Kang

    2016-01-01

    Atopic dermatitis (AD) is a chronic pruritic skin disorder affecting many people especially young children. It is a disease caused by the combination of genetic predisposition, immune dysregulation, and skin barrier defect. In recent years, emerging evidence suggests oxidative stress may play an important role in many skin diseases and skin aging, possibly including AD. In this review, we give an update on scientific progress linking oxidative stress to AD and discuss future treatment strategies for better disease control and improved quality of life for AD patients. PMID:27006746

  15. Iron Oxides

    SciTech Connect

    Qafoku, Nikolla; Amonette, James E.

    2016-09-19

    Abstract: Fe oxides are common clay-sized oxide, oxyhydroxide and hydroxide soil minerals. They are compounds of Fe, O, and H that have structures based on close-packed arrays of O. The octahedral and tetrahedral cavities within these arrays are filled with either Fe3+ or Fe2+ to form Fe(O/OH)6, FeO6, or FeO4 structural units. All of the naturally occurring Fe oxide minerals usually undergo some degree of isomorphous substitution of other metal ions for Fe in their structures. Relatively simple techniques may be used to identify Fe oxides in the field based on their typical colors and magnetic properties. In the laboratory, a variety of instrumental techniques can be used to confirm phase identity and to quantify amount. Of these, X-ray diffraction, infrared spectroscopy, electron microscopy, thermal analysis, and Mössbauer spectroscopy are the most commonly used techniques. As oxides, the functional groups on their surfaces may have positive, negative, or no charge depending on pH and on the concentration and nature of other ions in the contact solution. A net positive surface charge usually is observed in soils because Fe oxides have a point-of-zero-charge in the neutral or slightly basic pHs. The functional groups on the surface form complexes with cations and anions from the aqueous phase. Their sorption and electron-buffering properties significantly affect the geochemical cycles of almost all elements having agronomic or environmental significance.

  16. Progressive Supranuclear Palsy

    MedlinePlus

    ... Education » Fact Sheets Progressive Supranuclear Palsy Fact Sheet Table of Contents (click to jump to sections) What ... Information Page NINDS Epilepsy Information Page NINDS Familial Periodic Paralyses Information Page NINDS Farber's Disease Information Page ...

  17. Reporting Continuous Progress

    ERIC Educational Resources Information Center

    DeMott, Richard M.; Fistler, Ronald

    1973-01-01

    Described is the approach to evaluating student progress in the Iowa Braille and Sight Saving School which is based upon observable behaviors in all subject areas from kindergarten through grade 12. (MC)

  18. Progressive hemifacial atrophy

    PubMed Central

    Sande, Abhijeet; Risbud, Mukund; Kshar, Avinash; Paranjpe, Arati Oka

    2013-01-01

    Progressive hemifacial atrophy, also known as Parry-Romberg Syndrome, is an uncommon degenerative and poorly understood condition. It is characterized by a slow and progressive but self-limited atrophy affecting one side of the face. The incidence and the cause of this alteration are unknown. A cerebral disturbance of fat metabolism has been proposed as a primary cause. Possible factors that are involved in the pathogenesis include trauma, viral infections, heredity, endocrine disturbances and auto-immunity. The most common complications that appear in association to this disorder are: trigeminal neuralgia, facial paresthesia, severe headache and epilepsy. Characteristically, the atrophy progresses slowly for several years and, it becomes stable. The objective of this work is, through the presentation of a clinical case, to accomplish a literature review concerning general characteristics, etiology, physiopathology and treatment of progressive hemifacial atrophy. PMID:23878573

  19. Teaching "The Pilgrim's Progress"

    ERIC Educational Resources Information Center

    Batson, E. Beatrice

    1973-01-01

    The Pilgrim's Progress, apart from its hortatory religious nature, has imaginative, creative power to command the attention of English teachers at the college level and is discussed in terms of the classroom. (Editor)

  20. Progressive Supranuclear Palsy

    MedlinePlus

    Progressive supranuclear palsy (PSP) is a rare brain disease. It affects brain cells that control the movement of your eyes. This leads to ... speech, vision and swallowing problems. Doctors sometimes confuse PSP with Parkinson's disease or Alzheimer's disease. PSP has ...

  1. Immunotherapy Slows TNBC Progression.

    PubMed

    2015-06-01

    The experimental monoclonal antibody MPDL3280A extended progression-free survival and produced durable responses in some patients with triple-negative breast cancer, according to preliminary results from a phase I trial.

  2. Orion Progress - Spring 2010

    NASA Image and Video Library

    NASA and contractor teams are designing, building and testing the next generation human spacecraft Orion. Progress on Orion is highlighted by employees working on the project, along with video of t...

  3. Progress for the Paralyzed

    MedlinePlus

    ... this page please turn Javascript on. Feature: NIBIB Robotics Progress for the Paralyzed Past Issues / Spring 2013 ... Paralyzed —The expanding options for paralyzed individuals include: robotic arms spinal cord stimulation improved prosthetic limbs restored ...

  4. Progressive supranuclear palsy.

    PubMed

    Kent, Anna

    Progressive supranuclear palsy (PSP), or Steele-Richardson-Olszewski syndrome, is a rare, progressive neurodegenerative condition with cognitive and motor involvement. Diagnosis can be challenging as some people do not display the classic symptoms of the condition and there are no specific investigations to confirm diagnosis. Timely discussions and access to symptom management and palliative care services need to be provided from diagnosis throughout the disease trajectory to ensure holistic care of people with PSP.

  5. Progress Resupply Vehicle approach

    NASA Image and Video Library

    2012-01-28

    ISS030-E-050932 (27 Jan. 2012) --- Russian cosmonaut Anton Shkaplerov (left), Expedition 30 flight engineer, monitors data at the manual TORU docking system controls in the Zvezda Service Module of the International Space Station during approach and docking operations of the unpiloted ISS Progress 46 resupply vehicle. Progress 46 docked automatically to the Pirs Docking Compartment via the Kurs automated rendezvous system at 7:00 p.m. (EST) on Jan. 27, 2012. NASA astronaut Dan Burbank, commander, looks on.

  6. [Progressive visual agnosia].

    PubMed

    Sugimoto, Azusa; Futamura, Akinori; Kawamura, Mitsuru

    2011-10-01

    Progressive visual agnosia was discovered in the 20th century following the discovery of classical non-progressive visual agnosia. In contrast to the classical type, which is caused by cerebral vascular disease or traumatic injury, progressive visual agnosia is a symptom of neurological degeneration. The condition of progressive visual loss, including visual agnosia, and posterior cerebral atrophy was named posterior cortical atrophy (PCA) by Benson et al. (1988). Progressive visual agnosia is also observed in semantic dementia (SD) and other degenerative diseases, but there is a difference in the subtype of visual agnosia associated with these diseases. Lissauer (1890) classified visual agnosia into apperceptive and associative types, and it in most cases, PCA is associated with the apperceptive type. However, SD patients exhibit symptoms of associative visual agnosia before changing to those of semantic memory disorder. Insights into progressive visual agnosia have helped us understand the visual system and discover how we "perceive" the outer world neuronally, with regard to consciousness. Although PCA is a type of atypical dementia, its diagnosis is important to enable patients to live better lives with appropriate functional support.

  7. The role of protective scales in enhancing oxidation resistance

    SciTech Connect

    Smith, G.D.

    1996-12-01

    There has been steady progress in the development of wrought nickel-containing alloys for use in high temperature oxidizing environments. Contributing significantly to this progress is a growing knowledge base on the role of scales in enhancing oxidation resistance. Future improvements in oxidation resistance must build upon this understanding. This paper seeks to survey a portion of the wealth of information regarding scale characteristics of commercial wrought nickel-containing alloys and how scales are influenced by environment and alloy composition. Some suggestions as to the future direction of alloy development with regard to scale optimization and increased oxidation resistance are proposed.

  8. Immunochemical detection of oxidatively damaged DNA.

    PubMed

    Rossner, Pavel; Sram, Radim J

    2012-04-01

    Oxidatively damaged DNA is implicated in various diseases, including neurodegenerative disorders, cancer, diabetes, cardiovascular and inflammatory diseases as well as aging. Several methods have been developed to detect oxidatively damaged DNA. They include chromatographic techniques, the Comet assay, (32)P-postlabelling and immunochemical methods that use antibodies to detect oxidized lesions. In this review, we discuss the detection of 8-oxo-7,8-dihydro-29-deoxyguanosine (8-oxodG), the most abundant oxidized nucleoside. This lesion is frequently used as a marker of exposure to oxidants, including environmental pollutants, as well as a potential marker of disease progression. We concentrate on studies published between the years 2000 and 2011 that used enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry to detect 8-oxodG in humans, laboratory animals and in cell lines. Oxidative damage observed in these organisms resulted from disease, exposure to environmental pollutants or from in vitro treatment with various chemical and physical factors.

  9. Nitric oxide and oxidative stress in placental explant cultures.

    PubMed

    Goncalves, Juvic M; Casart, Ysabel C; Camejo, María I

    2016-01-01

    Placental explant culture, and cellular cytolysis and cellular differentiation have been previously studied. However, oxidative stress and nitric oxide profiles have not been evaluated in these systems. The aim of this study was to determine the release of lipid peroxidation and nitric oxide from placental explants cultured over a seven day period. Placental explants were maintained for seven days in culture and the medium was changed every 24 hours. The response was assessed in terms of syncytiotrophoblast differentiation (human chorionic gonadotropin, hCG), cellular cytolysis (lactate dehydrogenase, LDH), oxidative stress (thiobarbituric acid reactive substances, TBARS), and nitric oxide (NO). Levels of hCG increased progressively from day two to attain its highest level on days four and five after which it decreased gradually. In contrast, the levels of LDH, TBARS, and NO were elevated in the early days of placental culture when new syncytiotrophoblast from cytotrophoblast were forming and also in the last days of culture when tissue was declining. In conclusion, the levels of NO and lipid peroxidation follow a pattern similar to LDH and contrary to hCG. Future placental explant studies to evaluate oxidative stress and NO should consider the physiological changes inherent during the time of culture.

  10. Progressive multiple sclerosis

    PubMed Central

    Ontaneda, Daniel; Fox, Robert J.

    2015-01-01

    Purpose to Review To highlight the pathological features and clinical aspects of progressive multiple sclerosis (PMS). To highlight results of clinical trial experience to date and review ongoing clinical trials and perspective new treatment options. Explain the challenges of clinical trial design in PMS. Recent Findings MS has been identified as a chronic immune mediated disease, and the progressive phase of the disease appears to have significant neurodegenerative mechanisms. The classification of the course of PMS has been re-organized into categories of active vs. inactive inflammatory disease and the presence vs. absence of gradual disease progression. This differentiation allows clearer conceptualization of PMS and possibly even more efficient recruitment of PMS subjects into clinical trials. Clinical trial experience to date in PMS has been negative with anti-inflammatory medications used in relapsing MS. Simvastatin was recently tested in a phase II trial and showed a 43% reduction on annualized atrophy progression in secondary progressive MS. Ongoing PMS trials are currently being conducted with the phosphodiesterase inhibitor ibudilast, S1P modulator siponimod, and anti-B-cell therapy ocrelizumab. Several efforts for development of outcome measures in PMS are ongoing. Summary PMS represents a significant challenge, as the pathogenesis of the disease is not well understood, no validated outcome metrics have been established, and clinical trial experience to date has been disappointing. Advances in the understanding of the disease and lessons learned in previous clinical trials are paving the way for successful development of disease modifying agents for this disease. PMID:25887766

  11. Progress towards diesel combustion modeling

    SciTech Connect

    Rutland, C.J.; Ayoub, N.; Han, Z.

    1995-12-31

    Progress on the development and validation of a CFD model for diesel engine combustion and flow is described. A modified version of the KIVA code is used for the computations, with improved submodels for liquid breakup, drop distortion and drag, spray/wall impingement with rebounding, sliding and breaking-up drops, wall heat transfer with unsteadiness and compressibility, multistep kinetics ignition and laminar-turbulent characteristic time combustion models, Zeldovich NOx formation, and soot formation with Nagle Strickland-Constable oxidation. The code also considers piston-cylinder-liner crevice flows and allows computations of the intake flow process in the realistic engine geometry with two moving intake valves. Significant progress has been made using a modified RNG {kappa}-{var_epsilon} turbulence model, and a multicomponent fuel vaporization model and a flamelet combustion model have been implemented. Model validation experiments have been performed using a single-cylinder heavy duty truck engine that features state-of-the-art high pressure electronic fuel injection and emissions instrumentation. In addition to cylinder pressure, heat release, and emissions measurements, new combustion visualization experiments have also been performed using an endoscope system that takes the place of one of the exhaust valves. Modifications to the engine geometry for optical access were minimal, thus ensuring that the results represent the actual engine. The intake flow CFD modeling results show that the details of the intake flow process influence the engine performance. Comparisons with the measured engine cylinder pressure, heat release, soot and NOx emission data, and the combustion visualization flame images show that the CFD model results are generally in good agreement with the experiments. In particular, the model is able to correctly predict the soot-NOx trade-off trend as a function of injection timing. 44 refs., 21 figs., 6 tabs.

  12. Oxide Thermoelectrics

    SciTech Connect

    Singh, David J

    2008-01-01

    Thermoelectricity in oxides, especially NaxCoO2 and related materials, is discussed from the point of view of first principles calculations and Boltzmann transport theory. The electronic structure of this material is exceptional in that it has a combination of very narrow bands and strong hybridization between metal d states and ligand p states. As shown within the framework of conventional Boltzmann transport theory, this leads to high Seebeck coefficients even at metallic carrier densities. This suggests a strategy of searching for other narrow band oxides that can be doped metallic with mobile carriers. Some possible avenues for finding such materials are suggested.

  13. Oxidation catalyst

    DOEpatents

    Ceyer, Sylvia T.; Lahr, David L.

    2010-11-09

    The present invention generally relates to catalyst systems and methods for oxidation of carbon monoxide. The invention involves catalyst compositions which may be advantageously altered by, for example, modification of the catalyst surface to enhance catalyst performance. Catalyst systems of the present invention may be capable of performing the oxidation of carbon monoxide at relatively lower temperatures (e.g., 200 K and below) and at relatively higher reaction rates than known catalysts. Additionally, catalyst systems disclosed herein may be substantially lower in cost than current commercial catalysts. Such catalyst systems may be useful in, for example, catalytic converters, fuel cells, sensors, and the like.

  14. Progressive supranuclear palsy: progression and survival.

    PubMed

    Arena, Julieta E; Weigand, Stephen D; Whitwell, Jennifer L; Hassan, Anhar; Eggers, Scott D; Höglinger, Günter U; Litvan, Irene; Josephs, Keith A

    2016-02-01

    Progressive supranuclear palsy (PSP) is a progressive neurodegenerative disorder characterized by postural instability and falls, vertical supranuclear gaze palsy, parkinsonism with poor levodopa response, pseudobulbar palsy, and frontal release signs. The natural history of the disease has been previously described. However, the time frame of appearance of clinical milestones and how these symptoms may relate to survival in PSP are unknown. The primary objective was to determine the prevalence of symptoms at different stages of PSP and to estimate the time of appearance of clinical symptoms characteristic of the disease. Second, we determined the association between clinical symptoms and survival. We prospectively studied 35 PSP patients during assessments scheduled every 6 months for up to 2 years. We estimated symptoms prevalence and the association between symptoms and survival. The median age of onset was 65.9 years (IQR 60.6-70.0), and the median time from onset to first assessment was 3.0 years (IQR 2.4-3.9). The most commonly reported symptoms at baseline were: motor (100%) followed by cognitive/behavioral (89%), systemic and bulbar (80%), and sleep disturbances (60%). Slowness of movement, falls, neck stiffness and difficulty looking up/down had high prevalence from baseline, while balance and gait impairment were less common at baseline but increased in prevalence over time. The presence of sleep disturbances, and possibly hallucinations, was associated with increased death risk. Improved recognition of the clinical spectrum and milestones of PSP advances knowledge of the disease, helps earlier diagnosis, and allows prognostic predictions.

  15. Recent Progress in the DEOX Process

    SciTech Connect

    B.R. Westphal; K.J. Bateman; R.P. Lind; D.L. Wahlquist

    2006-06-01

    Recent Progress in the DEOX Process B.R. Westphal, K.J. Bateman, R.P. Lind, and D.L. Wahlquist Idaho National Laboratory: P.O. Box 1625, Idaho Falls, ID, 83415, and brian.westphal@inl.gov INTRODUCTION A head-end processing step is being developed for the treatment of spent oxide fuel by either aqueous or pyrochemical technologies. The head-end step, termed DEOX for its emphasis on decladding via oxidation, employs high temperatures to promote the oxidation of UO2 to U3O8 via an oxygen carrier gas. During oxidation, the spent fuel experiences a 30% increase in lattice structure volume resulting in the separation of fuel from cladding. An added benefit of the head-end step is the removal of fission products, either via direct release from the broken fuel structure or via oxidation and volatilization by the high temperature process. The DEOX program at the Idaho National Laboratory has progressed from an initial exploratory phase, where the objective was the optimization of particle size and fuel-clad separation [1], to a phase more applicable to current flowsheet development, i.e. the removal and collection of targeted fission products [2]. The behavior of fission products has been investigated via testing with irradiated spent fuel to determine the effects of temperature, pressure, oxidative gas, and cladding on the removal efficiencies of targeted fission products. In addition, a preliminary design for the retention of fission products in an off-gas treatment system has been initiated as part of a collaborative effort with Korea Atomic Energy Research Institute through an International Nuclear Energy Research Initiative (I-NERI). RECENT PROGRESS Using a set low temperature oxidation cycle near 500oC, additional conditions have been applied to distinguish their effects on the removal of targeted fission products. Both oxygen and air have been utilized during the oxidation portion followed by vacuum conditions to temperatures as high as 1050oC. In addition, the

  16. Pesticide reregistration progress report

    SciTech Connect

    Not Available

    1993-01-01

    The report is produced by the Special Review and Reregistration Division (SRRD), Office of Pesticide Programs, U.S. Environmental Protection Agency (EPA), on progress towards pesticide reregistration as mandated under 1988 amendments to the Federal Insecticide, Fungicide, and Rodenticide Act. The report shows the status of reregistration through the first quarter of the 1993 fiscal year. SRRD is in the process of re-evaluating the format and information in the Progress Report, as a result of the October 1992 Customer Survey sent to the recipients of the report. Results of the survey will be incorporated in the April 1993 issue of the report.

  17. Progress Resupply Vehicle approach

    NASA Image and Video Library

    2012-01-28

    ISS030-E-050933 (27 Jan. 2012) --- Russian cosmonauts Anton Shkaplerov (left) and Oleg Kononenko (partially obscured), both Expedition 30 flight engineers, monitor data at the manual TORU docking system controls in the Zvezda Service Module of the International Space Station during approach and docking operations of the unpiloted ISS Progress 46 resupply vehicle. Progress 46 docked automatically to the Pirs Docking Compartment via the Kurs automated rendezvous system at 7:00 p.m. (EST) on Jan. 27, 2012. NASA astronaut Dan Burbank (partially out of frame at right), commander, looks on.

  18. Progress 54 Spacecraft

    NASA Image and Video Library

    2014-02-05

    ISS038-E-042668 (5 Feb. 2014) --- An unpiloted ISS Progress resupply vehicle approaches the International Space Station, carrying 2.8 tons of food, fuel and supplies for the Expedition 38 crew members. The Progress 54 spacecraft launched from the Baikonur Cosmodrome in Kazakhstan at 11:23 a.m. (10:23 p.m. Baikonur time) and completed its four-orbit trek at 5:22 p.m. (EST) when it docked automatically to the station's Pirs docking compartment.

  19. Progress 54 Spacecraft

    NASA Image and Video Library

    2014-02-05

    ISS038-E-042674 (5 Feb. 2014) --- An unpiloted ISS Progress resupply vehicle approaches the International Space Station, carrying 2.8 tons of food, fuel and supplies for the Expedition 38 crew members. The Progress 54 spacecraft launched from the Baikonur Cosmodrome in Kazakhstan at 11:23 a.m. (10:23 p.m. Baikonur time) and completed its four-orbit trek at 5:22 p.m. (EST) when it docked automatically to the station's Pirs docking compartment.

  20. Progress 54 Spacecraft

    NASA Image and Video Library

    2014-02-05

    ISS038-E-042675 (5 Feb. 2014) --- An unpiloted ISS Progress resupply vehicle approaches the International Space Station, carrying 2.8 tons of food, fuel and supplies for the Expedition 38 crew members. The Progress 54 spacecraft launched from the Baikonur Cosmodrome in Kazakhstan at 11:23 a.m. (10:23 p.m. Baikonur time) and completed its four-orbit trek at 5:22 p.m. (EST) when it docked automatically to the station's Pirs docking compartment.

  1. Progress 54 Spacecraft

    NASA Image and Video Library

    2014-02-05

    ISS038-E-042680 (5 Feb. 2014) --- An unpiloted ISS Progress resupply vehicle approaches the International Space Station, carrying 2.8 tons of food, fuel and supplies for the Expedition 38 crew members. The Progress 54 spacecraft launched from the Baikonur Cosmodrome in Kazakhstan at 11:23 a.m. (10:23 p.m. Baikonur time) and completed its four-orbit trek at 5:22 p.m. (EST) when it docked automatically to the station's Pirs docking compartment.

  2. ISS Progress 24 Rollout

    NASA Image and Video Library

    2007-01-16

    JSC2007-E-03081 (16 Jan. 2007) --- Roll-out of the Progress 24 vehicle occurred on schedule at 7:00 a.m., Jan. 16, 2007 at the Baikonur Cosmodrome, Kazakhstan. The vehicle was in the vertical and hard-down at the pad by 9:30 a.m. The gantry towers were placed around the vehicle shortly thereafter. Progress is targeted for launch on Jan. 18, 2007 for a two-day trip to the International Space Station carrying 2 1/2 tons of food, fuel and supplies for the Expedition 14 crew. Photo Credit: NASA

  3. ISS Progress 24 Rollout

    NASA Image and Video Library

    2007-01-16

    JSC2007-E-03084 (16 Jan. 2007) --- Roll-out of the Progress 24 vehicle occurred on schedule at 7:00 a.m., Jan. 16, 2007 at the Baikonur Cosmodrome, Kazakhstan. The vehicle was in the vertical and hard-down at the pad by 9:30 a.m. The gantry towers were placed around the vehicle shortly thereafter. Progress is targeted for launch on Jan. 18, 2007 for a two-day trip to the International Space Station carrying 2 1/2 tons of food, fuel and supplies for the Expedition 14 crew. Photo Credit: NASA

  4. ISS Progress 24 Rollout

    NASA Image and Video Library

    2007-01-16

    JSC2007-E-03083 (16 Jan. 2007) --- Roll-out of the Progress 24 vehicle occurred on schedule at 7:00 a.m., Jan. 16, 2007 at the Baikonur Cosmodrome, Kazakhstan. The vehicle was in the vertical and hard-down at the pad by 9:30 a.m. The gantry towers were placed around the vehicle shortly thereafter. Progress is targeted for launch on Jan. 18, 2007 for a two-day trip to the International Space Station carrying 2 1/2 tons of food, fuel and supplies for the Expedition 14 crew. Photo Credit: NASA

  5. ISS Progress 24 Rollout

    NASA Image and Video Library

    2007-01-16

    JSC2007-E-03080 (16 Jan. 2007) --- Roll-out of the Progress 24 vehicle occurred on schedule at 7:00 a.m., Jan. 16, 2007 at the Baikonur Cosmodrome, Kazakhstan. The vehicle was in the vertical and hard-down at the pad by 9:30 a.m. The gantry towers were placed around the vehicle shortly thereafter. Progress is targeted for launch on Jan. 18, 2007 for a two-day trip to the International Space Station carrying 2 1/2 tons of food, fuel and supplies for the Expedition 14 crew. Photo Credit: NASA

  6. ISS Progress 24 Rollout

    NASA Image and Video Library

    2007-01-16

    JSC2007-E-03082 (16 Jan. 2007) --- Roll-out of the Progress 24 vehicle occurred on schedule at 7:00 a.m., Jan. 16, 2007 at the Baikonur Cosmodrome, Kazakhstan. The vehicle was in the vertical and hard-down at the pad by 9:30 a.m. The gantry towers were placed around the vehicle shortly thereafter. Progress is targeted for launch on Jan. 18, 2007 for a two-day trip to the International Space Station carrying 2 1/2 tons of food, fuel and supplies for the Expedition 14 crew. Photo Credit: NASA

  7. ALTERNATIVE OXIDANTS

    EPA Science Inventory

    This chapter reports on the efforts of the USEPA to study chloramines, chlorine dioxide and ozone as alternative oxidants/disinfectants to chlorine for the control of disinfection by-rpdocuts (DBPs) in drinking water. It examines the control of DBPs like trihalomethanes and haloa...

  8. Propylene oxide

    Integrated Risk Information System (IRIS)

    Propylene oxide ; CASRN 75 - 56 - 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 Noncarcinogenic Ef

  9. Merphos oxide

    Integrated Risk Information System (IRIS)

    Merphos oxide ; CASRN 78 - 48 - 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 Effe

  10. Thallium oxide

    Integrated Risk Information System (IRIS)

    Thallium oxide ; CASRN 1314 - 32 - 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 Noncarcinogenic E

  11. Ethylene oxide

    Integrated Risk Information System (IRIS)

    EPA / 635 / R - 16 / 350Fc www.epa.gov / iris Evaluation of the Inhalation Carcinogenicity of Ethylene Oxide EXECUTIVE SUMMARY ( CASRN 75 - 21 - 8 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) December 201 6 National Center for Environmental Assessment Office

  12. Nitric oxide

    Integrated Risk Information System (IRIS)

    Nitric oxide ; CASRN 10102 - 43 - 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 Noncarcinogenic Ef

  13. Molecular characterization of bacterial respiration on minerals. Progress report, June 1992--November, 1993

    SciTech Connect

    Blake, R. II.

    1993-12-31

    Progress is reported towards elucidating electron transport components of Thiobacillus ferrooxidans involved in the metabolic oxidation of iron. Also included are results of an investigation into the molecular principles whereby the bacteria recognize and adhere to their insoluble substrates

  14. Protein carbonylation, cellular dysfunction, and disease progression

    PubMed Central

    Dalle-Donne, Isabella; Aldini, Giancarlo; Carini, Marina; Colombo, Roberto; Rossi, Ranieri; Milzani, Aldo

    2006-01-01

    Carbonylation of proteins is an irreversible oxidative damage, often leading to a loss of protein function, which is considered a widespread indicator of severe oxidative damage and disease-derived protein dysfunction. Whereas moderately carbonylated proteins are degraded by the proteasomal system, heavily carbonylated proteins tend to form high-molecular-weight aggregates that are resistant to degradation and accumulate as damaged or unfolded proteins. Such aggregates of carbonylated proteins can inhibit proteasome activity. A large number of neurodegenerative diseases are directly associated with the accumulation of proteolysis-resistant aggregates of carbonylated proteins in tissues. Identification of specific carbonylated protein(s) functionally impaired and development of selective carbonyl blockers should lead to the definitive assessment of the causative, correlative or consequential role of protein carbonylation in disease onset and/or progression, possibly providing new therapeutic aproaches. PMID:16796807

  15. Progress in planar SOFC science and technology

    SciTech Connect

    Khandkar, A.C.; Elangovan, S.; Hartvigsen, J.J.

    1996-12-31

    Solid oxide fuel cells offer an attractive alternative to the present power generation technologies. High efficiency, low noise and vibration, and low emissions are prime reasons for developing this technology. Extensive research and development activity has been carried out at SOFCo in advancing the materials and fabrication technologies. The work has resulted in demonstrating a 1.4 kW natural gas fueled SOFC system. The current activities focus on improving the performance and endurance of stacks, evaluating various system concepts leading to viable commercial and military applications. The challenges offered by various developmental areas and the progress made in technology demonstration are discussed.

  16. [Progress on transgenic mosquitoes].

    PubMed

    Yang, Pin

    2011-04-30

    The genetically modified mosquitoes have been developed aiming to control mosquito-borne diseases by either reducing population sizes or replacing existing populations with vectors unable to transmit the disease. introduces some progress on the generation of transgenic mosquitoes and their fitness in wild population. This paper

  17. Basic Measures of Progress.

    ERIC Educational Resources Information Center

    Calkins, Julia; Ling, Thomson; Moore, Eric; Halle, Tamara; Hair, Beth; Moore, Kris; Zaslow, Marty

    This document provides a compilation of measures of progress toward school readiness and three contributing conditions as used in several local, state, and national surveys. The report begins with a legend listing the surveys examined, their acronyms, and contact information. The remainder of the report, in tabular format, lists measures of…

  18. MCNP Progress & Performance Improvements

    SciTech Connect

    Brown, Forrest B.; Bull, Jeffrey S.; Rising, Michael Evan

    2015-04-14

    Twenty-eight slides give information about the work of the US DOE/NNSA Nuclear Criticality Safety Program on MCNP6 under the following headings: MCNP6.1.1 Release, with ENDF/B-VII.1; Verification/Validation; User Support & Training; Performance Improvements; and Work in Progress. Whisper methodology will be incorporated into the code, and run speed should be increased.

  19. Mystery in Progress.

    ERIC Educational Resources Information Center

    Hall, Kristen

    1989-01-01

    Describes "Mystery in Progress," a traveling exhibit which traces the development of Predynastic Egypt. The exhibit provides a time line for Predynastic Egypt, depicts the history of the Hierakonpolis expedition, documents the formation of Egypt's first centralized nation state, and summarizes the emergence of a unified Egypt. (LS)

  20. Progress in physiological optics.

    PubMed

    Boynton, R M

    1967-08-01

    A survey is made of the current state of physiological optics, broadly defined as equated with visual science. After a survey of some historical and definitional matters, recent progress in a number of areas is critically reviewed. Finally, seven examples of important recent discoveries in physiological optics are given.

  1. Music and Progressive Education.

    ERIC Educational Resources Information Center

    Zinar, Ruth

    1984-01-01

    John Dewey believed that man can only learn about the world through experience. He included music as part of his "core curriculum," in which children learned by doing. This progressive education emphasized self-expression and individual fulfillment, but did not mean the abandonment of knowledge and techniques in teaching music. (CS)

  2. Response: Progress Takes Time.

    ERIC Educational Resources Information Center

    Rist, Marilee C.

    1984-01-01

    Although declining enrollment and administrative seniority have hampered efforts to eliminate sex discrimination in employment practices in three Long Island, New York, school systems (Commack, Smithtown, and Bay Shore), progress is being made. Because of the Reagan administration's lack of support for affirmative action, however, litigation…

  3. Learning Progressions & Climate Change

    ERIC Educational Resources Information Center

    Parker, Joyce M.; de los Santos, Elizabeth X.; Anderson, Charles W.

    2015-01-01

    Our society is currently having serious debates about sources of energy and global climate change. But do students (and the public) have the requisite knowledge to engage these issues as informed citizenry? The learning-progression research summarized here indicates that only 10% of high school students typically have a level of understanding…

  4. Opportunities and progress.

    PubMed

    Litchfield, John H

    2014-01-01

    In this review, I cover my professional experiences in food science and technology and related areas of applied and industrial microbiology over the span of my career. It emphasizes opportunities and technological problems that I encountered together with my progress in follow-up development of products and processes.

  5. Mystery in Progress.

    ERIC Educational Resources Information Center

    Hall, Kristen

    1989-01-01

    Describes "Mystery in Progress," a traveling exhibit which traces the development of Predynastic Egypt. The exhibit provides a time line for Predynastic Egypt, depicts the history of the Hierakonpolis expedition, documents the formation of Egypt's first centralized nation state, and summarizes the emergence of a unified Egypt. (LS)

  6. 1992 PVUSA progress report

    SciTech Connect

    Ellyn, W.

    1992-12-31

    Photovoltaics for Utility Scale Applications (PVUSA) is a national public-private partnership that is assessing and demonstrating the viability of utility-scale photovoltaic (PV) electric generating systems. This report updates the progress of the PVUSA project, reviews the status and performance of the various PV installations during 1992, and summarizes key accomplishments and conclusions from work to date.

  7. Progress and promise.

    PubMed

    Kamphaus, Randy W

    2012-12-01

    This editorial introduces the current issue of the journal School Psychology Quarterly (SPQ).There has been an impressive and promising progress of school psychology science has been reflected in every issue of SPQ, including the current one. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  8. Learning Progressions & Climate Change

    ERIC Educational Resources Information Center

    Parker, Joyce M.; de los Santos, Elizabeth X.; Anderson, Charles W.

    2015-01-01

    Our society is currently having serious debates about sources of energy and global climate change. But do students (and the public) have the requisite knowledge to engage these issues as informed citizenry? The learning-progression research summarized here indicates that only 10% of high school students typically have a level of understanding…

  9. Assessing Pupils' Progress

    ERIC Educational Resources Information Center

    Ollerton, Mike

    2010-01-01

    In this article, the author explores what Assessing Pupils' Progress (APP) is about. He contends that the predilection for testing is a catastrophe as far as the teaching and learning of mathematics is concerned; it is an outcome of the drive for collecting so-called "data" on pupils. What those people, who should know better, either choose to…

  10. Progressive Response Surfaces

    NASA Technical Reports Server (NTRS)

    Romero, V. J.; Swiler, L. P.

    2004-01-01

    Response surface functions are often used as simple and inexpensive replacements for computationally expensive computer models that simulate the behavior of a complex system over some parameter space. Progressive response surfaces are ones that are built up progressively as global information is added from new sample points in the parameter space. As the response surfaces are globally upgraded based on new information, heuristic indications of the convergence of the response surface approximation to the exact (fitted) function can be inferred. Sampling points can be incrementally added in a structured fashion, or in an unstructured fashion. Whatever the approach, at least in early stages of sampling it is usually desirable to sample the entire parameter space uniformly. At later stages of sampling, depending on the nature of the quantity being resolved, it may be desirable to continue sampling uniformly over the entire parameter space (Progressive response surfaces), or to switch to a focusing/economizing strategy of preferentially sampling certain regions of the parameter space based on information gained in early stages of sampling (Adaptive response surfaces). Here we consider Progressive response surfaces where a balanced indication of global response over the parameter space is desired.We use a variant of Moving Least Squares to fit and interpolate structured and unstructured point sets over the parameter space. On a 2-D test problem we compare response surface accuracy for three incremental sampling methods: Progressive Lattice Sampling; Simple-Random Monte Carlo; and Halton Quasi-Monte-Carlo sequences. We are ultimately after a system for constructing efficiently upgradable response surface approximations with reliable error estimates.

  11. Mechanical Instability of Oxidized Metal Clusters

    NASA Astrophysics Data System (ADS)

    Celino, Massimo; Cleri, Fabrizio; D'Agostino, Gregorio; Rosato, Vittorio

    1996-09-01

    A mechanism to explain the complete oxidation of small metal clusters is proposed, based on the occurrence of a mechanical instability driven by the expansion of the progressively oxidized cluster surface and the subsequent stress relaxation. Molecular dynamics simulations of spherical Pd clusters show that an expanded surface layer is capable of straining the inner core of the cluster up to the point of inducing cavitation. These findings allow the interpretation of recent experimental results in which oxidized Pd clusters exhibit a hollow spherical shape.

  12. Oxidative Stress in Diabetic Nephropathy

    PubMed Central

    Kashihara, N.; Haruna, Y.; Kondeti, V.K.; Kanwar, Y.S.

    2013-01-01

    Diabetic nephropathy is a leading cause of end-stage renal failure worldwide. Its morphologic characteristics include glomerular hypertrophy, basement membrane thickening, mesangial expansion, tubular atrophy, interstitial fibrosis and arteriolar thickening. All of these are part and parcel of microvascular complications of diabetes. A large body of evidence indicates that oxidative stress is the common denominator link for the major pathways involved in the development and progression of diabetic micro- as well as macrovascular complications of diabetes. There are a number of macromolecules that have been implicated for increased generation of reactive oxygen species (ROS), such as, NAD(P)H oxidase, advanced glycation end products (AGE), defects in polyol pathway, uncoupled nitric oxide synthase (NOS) and mitochondrial respiratory chain via oxidative phosphorylation. Excess amounts of ROS modulate activation of protein kinase C, mitogen-activated protein kinases, and various cytokines and transcription factors which eventually cause increased expression of extracellular matrix (ECM) genes with progression to fibrosis and end stage renal disease. Activation of renin-angiotensin system (RAS) further worsens the renal injury induced by ROS in diabetic nephropathy. Buffering the generation of ROS may sound a promising therapeutic to ameliorate renal damage from diabetic nephropathy, however, various studies have demonstrated minimal reno-protection by these agents. Interruption in the RAS has yielded much better results in terms of reno-protection and progression of diabetic nephropathy. In this review various aspects of oxidative stress coupled with the damage induced by RAS are discussed with the anticipation to yield an impetus for designing new generation of specific antioxidants that are potentially more effective to reduce reno-vascular complications of diabetes. PMID:20939814

  13. Oxidative stress in IgA nephropathy.

    PubMed

    Coppo, R; Camilla, R; Amore, A; Peruzzi, L

    2010-01-01

    IgA nephropathy (IgAN) is characterized by mesangial deposits of IgA1, likely due to accumulation of IgA immune complexes. The activation of intracellular signaling mostly results in oxidative stress, as detected in mesangial cells cultured with aberrantly glycosylated IgA or IgA aggregates and in renal biopsies of patients with IgAN. Signs of altered oxidation/antioxidation balance have been detected in sera and/or in erythrocytes of patients with IgAN, including increased levels of lipoperoxide or malondialdehyde and reduced activity of superoxide dismutase, catalase and glutathione peroxidase. Moreover, increased levels of a marker of oxidative stress, advanced oxidation protein products (AOPPs), have been reported to be significantly associated with proteinuria and disease progression in patients with IgAN. AOPPs are often carried by albumin and can in turn enhance the oxidative stress in the circulation. Recent research suggests that the nephrotoxicity of aberrantly glycosylated IgA1 in IgAN is enhanced in the presence of systemic signs of oxidative stress, and it is tempting to hypothesize that the level of the oxidative milieu conditions the different expression and progression of IgAN.

  14. The Progressive Era.

    PubMed

    Chambers, David W

    2005-01-01

    The American College of Dentists was founded in 1920 for the purpose of encouraging young dentists to continue study and to apply science to their practices. This ideal emerged in the Progressive Era, which lasted roughly from 1895 to 1920. The animating spirit of this period was that the human condition could be improved and that the way to achieve this was through science and the use of experts working together. The Progressive Era saw inventions, such as automobiles and airplanes, telephone and radio, that required mass production and brought people together. It also spawned many political and legislative innovations that we now take for granted. Among these are the Food and Drug Administration, the Department of Commerce, and the Federal Trade Commission. Workers' compensation and other social protections were introduced, as were city commissions; the income tax; women's suffrage; and initiative, referendum, and recall. Medicine, for the first time, became an effective way to treat disease as it developed a scientific foundation.

  15. Solid oxide electrochemical reactor science.

    SciTech Connect

    Sullivan, Neal P.; Stechel, Ellen Beth; Moyer, Connor J.; Ambrosini, Andrea; Key, Robert J.

    2010-09-01

    Solid-oxide electrochemical cells are an exciting new technology. Development of solid-oxide cells (SOCs) has advanced considerable in recent years and continues to progress rapidly. This thesis studies several aspects of SOCs and contributes useful information to their continued development. This LDRD involved a collaboration between Sandia and the Colorado School of Mines (CSM) ins solid-oxide electrochemical reactors targeted at solid oxide electrolyzer cells (SOEC), which are the reverse of solid-oxide fuel cells (SOFC). SOECs complement Sandia's efforts in thermochemical production of alternative fuels. An SOEC technology would co-electrolyze carbon dioxide (CO{sub 2}) with steam at temperatures around 800 C to form synthesis gas (H{sub 2} and CO), which forms the building blocks for a petrochemical substitutes that can be used to power vehicles or in distributed energy platforms. The effort described here concentrates on research concerning catalytic chemistry, charge-transfer chemistry, and optimal cell-architecture. technical scope included computational modeling, materials development, and experimental evaluation. The project engaged the Colorado Fuel Cell Center at CSM through the support of a graduate student (Connor Moyer) at CSM and his advisors (Profs. Robert Kee and Neal Sullivan) in collaboration with Sandia.

  16. Current progress in pharmacogenetics

    PubMed Central

    Blakey, John D; Hall, Ian P

    2011-01-01

    The study of genetic variation has the potential to aid understanding of the mechanisms underlying the observed inter-individual variation in drug response and by which idiosyncratic adverse effects occur. In this review, we outline current progress in pharmacogenetics using examples to highlight both mechanisms of influence of polymorphisms and research strategies for their detection. In the final sections we discuss contemporary challenges for both researchers and clinicians. PMID:21235621

  17. Progress in Scientific Visualization

    SciTech Connect

    Max, N

    2004-11-15

    Visualization of observed data or simulation output is important to science and engineering. I have been particularly interested in visualizing 3-D structures, and report here my personal impressions on progress in the last 20 years in visualizing molecules, scalar fields, and vector fields and their associated flows. I have tried to keep the survey and list of references manageable, so apologize to those authors whose techniques I have not mentioned, or have described without a reference citation.

  18. Xenon Feed System Progress

    DTIC Science & Technology

    2006-01-01

    From - To) 13-06-2006 Technical Paper 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER F04611-00-C-0055 Xenon Feed System Progress (Preprint) 5b. GRANT...propulsion xenon feed system for a flight technology demonstration program. Major accomplishments include: 1) Utilization of the Moog...successfully fed xenon to a 200 watt Hall Effect Thruster in a Technology Demonstration Program. The feed system has demonstrated throttling of xenon

  19. [Progress in optical imaging].

    PubMed

    Bremer, C; Ntziachristos, V; Mahmood, U; Tung, C H; Weissleder, R

    2001-02-01

    Different optical imaging technologies have significantly progressed over the last years. Besides advances in imaging techniques and image reconstruction, new "smart" optical contrast agents have been developed which can be used to detect molecular targets (such as endogenous enzymes) in vivo. The combination of novel imaging technologies coupled with smart agents bears great diagnostic potential both clinically and experimentally. This overview outlines the basic principles of optical imaging and summarizes the current state of the art.

  20. ISABELLE: a progress report

    SciTech Connect

    Hahn, H

    1980-01-01

    This paper discusses the ISABELLE project, which has the objective of constructing a high-energy proton colliding beam facility at Brookhaven National Laboratory. The major technical features of the intersecting storage accelerators with their projected performance are described. Application of over 1000 superconducting magnets in the two rings represents the salient characteristic of the machine. The status of the entire project, the technical progress made so far, and difficulties encountered are reviewed.

  1. COSMIC monthly progress report

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Activities of the Computer Software Management and Information Center (COSMIC) are summarized for the month of January 1994. Tables showing the current inventory of programs available from COSMIC are presented and program processing and evaluation activities are discussed. Marketing and customer service activities in this period are presented as is the progress report of NASTRAN maintenance and support. Tables of disseminations and budget summary conclude the report.

  2. Progress In Holographic Cinematography

    NASA Astrophysics Data System (ADS)

    Smigielski, P.; Fagot, H.; Albe, F.

    1986-06-01

    Two important progresses were achieved for the first time: 1) recording of single exposure cineholograms of living bodies on a 126-mm film, at a frequency of 25 holograms per second. Limitations of 3-D movies by holography are described. 2) recording of double-exposure cineholograms of reflecting objects, a loudspeaker membrane and the vertex cranii of a bald-headed man. These experiments show the interest of interferometric cineholography for industrial applications.

  3. Mixed oxide fuel development

    SciTech Connect

    Leggett, R.D.; Omberg, R.P.

    1987-05-08

    This paper describes the success of the ongoing mixed-oxide fuel development program in the United States aimed at qualifying an economical fuel system for liquid metal cooled reactors. This development has been the cornerstone of the US program for the past 20 years and has proceeded in a deliberate and highly disciplined fashion with high emphasis on fuel reliability and operational safety as major features of an economical fuel system. The program progresses from feature testing in EBR-II to qualifying full size components in FFTF under fully prototypic conditions to establish a basis for extending allowable lifetimes. The development program started with the one year (300 EFPD) core, which is the FFTF driver fuel, continued with the demonstration of a two year (600 EFPD) core and is presently evaluating a three year (900 EFPD) fuel system. All three of these systems, consistent with other LMR fuel programs around the world, use fuel pellets gas bonded to a cladding tube that is assembled into a bundle and fitted into a wrapper tube or duct for ease of insertion into a core. The materials of construction progressed from austenitic CW 316 SS to lower swelling austenitic D9 to non swelling ferritic/martensitic HT9. 6 figs., 2 tabs.

  4. Primary Progressive Speech Abulia.

    PubMed

    Milano, Nicholas J; Heilman, Kenneth M

    2015-01-01

    Primary progressive aphasia (PPA) is a neurodegenerative disorder characterized by progressive language impairment. The three variants of PPA include the nonfluent/agrammatic, semantic, and logopenic types. The goal of this report is to describe two patients with a loss of speech initiation that was associated with bilateral medial frontal atrophy. Two patients with progressive speech deficits were evaluated and their examinations revealed a paucity of spontaneous speech; however their naming, repetition, reading, and writing were all normal. The patients had no evidence of agrammatism or apraxia of speech but did have impaired speech fluency. In addition to impaired production of propositional spontaneous speech, these patients had impaired production of automatic speech (e.g., reciting the Lord's Prayer) and singing. Structural brain imaging revealed bilateral medial frontal atrophy in both patients. These patients' language deficits are consistent with a PPA, but they are in the pattern of a dynamic aphasia. Whereas the signs-symptoms of dynamic aphasia have been previously described, to our knowledge these are the first cases associated with predominantly bilateral medial frontal atrophy that impaired both propositional and automatic speech. Thus, this profile may represent a new variant of PPA.

  5. Progressive contour models

    NASA Astrophysics Data System (ADS)

    Lin, Remin; Lin, Wei-Chung; Chen, Chin-Tu

    1995-08-01

    A progressive contour model is developed based on the idea of deforming the contour from an initial shape as a source of prior knowledge by minimizing a defined contour energy to extract a desired contour from images. This model differs from active contour models (or snakes) in that the internal component of the contour energy is used to impose the smoothness constraints not on the shape of the contour but on the displacements of deformation, and the external component of the contour energy is used to locate the correspondence for the contour through a specified local correspondence mapping. A sequence of deformations is determined by repeatedly deforming and updating the initial contour. It is shown that the contour deformed by this sequence will smoothly and progressively approach a well-defined contour. Finite- element methods, multigrid algorithms, and unconstrained optimization methods are employed to implement this model. This approach offers several attractive advantages including a good convergence rate, the adaptation of the smoothness constraints and the adoption of a globally convergent algorithm. Experiments are conducted on real images to evaluate the performance of a progressive contour program, and a computational complexity in the order of O (lnN) is verified.

  6. Topiramate in migraine progression.

    PubMed

    Ruiz, Luigi; Ferrandi, Delfina

    2009-12-01

    Increasing evidence shows that migraine, typically considered as an episodic disease, is a chronic and, in some patients, progressive disorder. Among neuromodulators used for migraine prevention, topiramate has a high level of evidence-based efficacy. Through its wide range of mechanisms of action topiramate increases the activation threshold resulting in neuronal stabilization and thereby reducing cortical neurons hyperexcitability, which is believed to be an important electrophysiological feature underlying the pathogenesis of epilepsy and migraine. Recent studies show that migraineurs have subclinical structural brain changes and persistent alteration of pain perception, in some cases correlated with the duration of the disease and the frequency of attacks that might play a role in the transformation of episodic migraine to chronic forms. An early and prolonged preventive treatment might reduce the risk of such transformation. Recent evidence suggests that topiramate, by reducing migraine frequency and use of acute medication, may prevent the negative progression of migraine. Furthermore, two recently completed multicenter, randomised, placebo-controlled trials have shown that treatment with topiramate 100 mg/day is effective and well tolerated in patients already progressed to chronic migraine and difficult to treat conditions associated with medication-overuse. Topiramate seems to be a preventive treatment, which might be able to act at different levels of the migraine cycle: reduction of frequency in episodic migraine, prevention, and treatment of chronic migraine.

  7. Research Performance Progress Report

    SciTech Connect

    Theopold, Klaus H.

    2015-11-30

    The focus of this project was catalysis by ‘proton coupled electron transfer’ (PCET) to metal bound fragments derived from the most abundant small molecules (i. e. O2 and N2). There are many important chemical challenges that are tied to this fundamental reaction type. Among these are: metal catalyzed oxidations of organic molecules utilizing O2 as the oxidant; reduction of O2 to water close to the thermodynamic potential – in other words, the cathode of any fuel cell based on reactions with O 2; transfer of reduced nitrogen species to organic substrates; fixation of nitrogen at modest temperatures and pressures. Any one of these problems has obvious implications for the generation and/or utilization of energy on a large scale.

  8. Heterogeneous photocatalytic oxidation of atmospheric trace contaminants

    NASA Technical Reports Server (NTRS)

    Ollis, David F.

    1993-01-01

    The progress report on heterogeneous photocatalytic oxidation of atmospheric trace contaminants covering the period from 1 May - 31 Oct. 1992 is presented. The two topics discussed are photoreactor monolith fundamental studies and monolith reactor operation: batch recirculation system. Concentration profiles are shown.

  9. Thin-Film Solid Oxide Fuel Cells

    NASA Technical Reports Server (NTRS)

    Chen, Xin; Wu, Nai-Juan; Ignatiev, Alex

    2009-01-01

    The development of thin-film solid oxide fuel cells (TFSOFCs) and a method of fabricating them have progressed to the prototype stage. This can result in the reduction of mass, volume, and the cost of materials for a given power level.

  10. Oxidative Damage in Parkinson’s Disease

    DTIC Science & Technology

    2003-01-01

    supranuclear palsy brains. There were no significant alterations in 8-hydroxy-2- deoxyguanosine in the plasma of PD patients. We found that...patients and a number of specific genes linked to oxidative stress were reduced in expression. There was increased lipid peroxidation in progressive

  11. Final Technical Progress Report

    SciTech Connect

    J.Y. Hwang; R.C. Greenlund

    2002-12-31

    Michigan Technological University has demonstrated major inroads in establishing the viability of utilizing aluminum smelting by-product waste materials in lightweight concrete product applications. The research identified key elements of producing various forms of lightweight concrete products through utilizing various procedures and mixture components with the by-product materials. A process was developed through pilot plant testing that results in additional aluminum recovery at finer sizes, a clean returnable salt product through spray drying technology, and a low-salt-content oxide product with enough aluminum metal content that it can be used to form lightweight cementitious mixtures. Having three distinct products aids in generating favorable process economics. Revenue projections from aluminum recovery and salt recovery are enough to cover processing costs and create a cost-free oxide product to market for lightweight concrete applications. This supply side commercialization strategy offers aluminum by-product recyclers a potentially no cost product, which has been demonstrated through this project to create desirable and marketable lightweight concrete products of various forms. Environmental benefits to the public are tremendous. At best, all dross and salt cake materials have the potential to be completely recycled and utilized. At worst, disposal sites would see a reduced amount of material: a post processed oxide product with little salt and no hydrogen sulfide or ammonia gas generating capability, which, if isolated from high alkali conditions, would pose no reactivity concerns. The US aluminum industry has historically, along with the steel industry, been a leader in recycling metal. The findings from this project, increased metal recovery, improved salt recycling, and demonstrated end uses for oxide residues, will go a long way in helping the aluminum industry obtain 100% material utilization and zero discharge.

  12. An investigation of molybdenum and molybdenum oxide catalyzed hydrocarbon formation reactions. [Surface chemistry of ethylene oxide on Pd(111)

    SciTech Connect

    Not Available

    1993-01-01

    Progress was made in the following four areas: activity of model catalyst (Mo oxides) for olefin metathesis (2 C[sub 3]H[sub 6] [r arrow] C[sub 4]H[sub 8] + C[sub 2]H[sub 4]); kinetics of Mo(100)-catalyzed olefin metathesis; surface chemistry of ethylene oxide on Pd(111); and uv source construction.

  13. Stop chronic kidney disease progression: Time is approaching

    PubMed Central

    Sharaf El Din, Usama Abdel Azim; Salem, Mona Mansour; Abdulazim, Dina Ossama

    2016-01-01

    Progression of chronic kidney disease (CKD) is inevitable. However, the last decade has witnessed tremendous achievements in this field. Today we are optimistic; the dream of withholding this progression is about to be realistic. The recent discoveries in the field of CKD management involved most of the individual diseases leading the patients to end-stage renal disease. Most of these advances involved patients suffering diabetic kidney disease, chronic glomerulonephritis, polycystic kidney disease, renal amyloidosis and chronic tubulointerstitial disease. The chronic systemic inflammatory status and increased oxidative stress were also investigated. This inflammatory status influences the anti-senescence Klotho gene expression. The role of Klotho in CKD progression together with its therapeutic value are explored. The role of gut as a major source of inflammation, the pathogenesis of intestinal mucosal barrier damage, the role of intestinal alkaline phosphatase and the dietary and therapeutic implications add a novel therapeutic tool to delay CKD progression. PMID:27152262

  14. Post Kalman progress

    NASA Technical Reports Server (NTRS)

    Sonnabend, David

    1995-01-01

    In a paper here last year, an idea was put forward that much greater performance could be obtained from an observer, relative to a Kalman filter if more general performance indices were adopted, and the full power spectra of all the noises were employed. The considerable progress since then is reported here. Included are an extension of the theory to regulators, direct calculation of the theory's fundamental quantities - the noise effect integrals - for several theoretical spectra, and direct derivations of the Riccati equations of LQG (Linear-Quadratic-Gaussian) and Kalman theory yielding new insights.

  15. MEIC Design Progress

    SciTech Connect

    Zhang, Y; Douglas, D; Hutton, A; Krafft, G A; Li, R; Lin, F; Morozov, V S; Nissen, E W; Pilat, F C; Satogata, T; Tennant, C; Terzic, B; Yunn, C; Barber, D P; Filatov, Y; Hyde, C; Kondratenko, A M; Manikonda, S L; Ostroumov, P N; Sullivan, M K

    2012-07-01

    This paper will report the recent progress in the conceptual design of MEIC, a high luminosity medium energy polarized ring-ring electron-ion collider at Jefferson lab. The topics and achievements that will be covered are design of the ion large booster and the ERL-circulator-ring-based electron cooling facility, optimization of chromatic corrections and dynamic aperture studies, schemes and tracking simulations of lepton and ion polarization in the figure-8 collider ring, and the beam-beam and electron cooling simulations. A proposal of a test facility for the MEIC electron cooler will also be discussed.

  16. Soyuz and Progress

    NASA Image and Video Library

    2014-05-30

    ISS040-E-006230 (30 May 2014) --- Two Russian spacecraft docked to the International Space Station are featured in this image photographed by an Expedition 40 crew member from inside the International Space Station?s Cupola. The Soyuz 39 (TMA-13M) spacecraft, docked to the Rassvet Mini-Research Module 1 (MRM1), is visible in the foreground. The Progress 55 resupply vehicle, docked to the Pirs Docking Compartment, is visible in the background. A blue and white part of Earth and the blackness of space provide the backdrop for the scene.

  17. [Progress in eyeglass optics].

    PubMed

    Köppen, W

    1995-08-01

    In this article product developments for ophthalmic lenses are discussed: new materials, designs and coatings. High-index plastic substrates allow to offer corrections which are simultaneously light and thin and for the first time there are high performant plastic photochromic lenses. Head and eye movements with latest generation's progressives are very similar to natural vision behaviour. Special aspheric designs have been developed for comfortable vision for near and intermediate distances. Finally there are new coatings which protect the high quality surfaces of plastic lenses distinctly longer than before.

  18. Progress in computational physics

    NASA Technical Reports Server (NTRS)

    Turkel, E.

    1983-01-01

    Recent progress in computational methods for time dependent fluid dynamics is presented. The emphasis is on advances applicable to large scale systems with the connection between the numerics and the physics of the code stressed. All aspects of a working code are discussed including such topics as initialization, boundary conditions, grid generation in addition to algorithmic advances. One sometimes uses a time dependent method as an iteration procedure to reach a steady state solution. Work in accelerating the convergence to the steady state is also surveyed.

  19. Progressive image denoising.

    PubMed

    Knaus, Claude; Zwicker, Matthias

    2014-07-01

    Image denoising continues to be an active research topic. Although state-of-the-art denoising methods are numerically impressive and approch theoretical limits, they suffer from visible artifacts.While they produce acceptable results for natural images, human eyes are less forgiving when viewing synthetic images. At the same time, current methods are becoming more complex, making analysis, and implementation difficult. We propose image denoising as a simple physical process, which progressively reduces noise by deterministic annealing. The results of our implementation are numerically and visually excellent. We further demonstrate that our method is particularly suited for synthetic images. Finally, we offer a new perspective on image denoising using robust estimators.

  20. Progress 39 Supply Vehicle

    NASA Image and Video Library

    2011-02-20

    ISS026-E-028490 (20 Feb. 2011) --- Backdropped by a blue and white part of Earth, the unpiloted ISS Progress 39 supply vehicle appears to be very small as it departs from the International Space Station at 8:12 a.m. (EST) on Feb. 20, 2011. At 11:12 a.m., the deorbit burn braked the trash-loaded cargo ship into its re-entry trajectory over the Pacific Ocean, where it was burned up in Earth’s atmosphere.

  1. Annual Progress Report.

    DTIC Science & Technology

    1981-10-20

    AD-AIO6 983 ILLINOIS UNIV AT URBANA COORDINATEO SCIENCE LAB F/0 12/1 ANNUAL PROGRESS REPOMT ,(U1 OCT 81 H V POOR NOOOII-81-K-O014 UNCLASSIFIED T-111...34 University of Illinois at Urbana -Chaimpaign Urbana , Illinois 61801 I ~~ ~ ~ ~ I I7 CONROLINOFIC______NDADDES Office of Naval Research - Octe--mm...Unclassified Approved for public release; dis tribu tion ’anlimi ted. 17. DISTRIBUTION STATEMENT (of the aboeet onfored a Weak 20. 1# Offrmoaw Repeol

  2. HSX progress report

    SciTech Connect

    Not Available

    1994-05-01

    Brief statements on the progress of the design and construction of the HSX experiment are reported. Topics covered include the modular and auxiliary coil systems, the coil support structure, vacuum vessel, the ECH system, the magnet power supply and site. The proposed budget for Year 2 (August 1, 1994 through July 31, 1995) is presented. The effects of a flat funding profile (based on Year 2 budget level of $1137K) on out-years and the HSX project schedule are discussed. The stretching out of the program to accommodate the reduced funding profile should result in only a slight delay in HSX operations.

  3. PROGRESS ON STELLA EXPERIMENT.

    SciTech Connect

    KIMURA,W.D.; CAMPBELL,L.P.; GOTTSCHALK,S.C.; QUIMBY,D.C.; ROBINSON,K.E.; STEINHAUER,L.C.; BABZIEN,M.; BEN-ZVI,I.; GALLARDO,J.C.; KUSCHE,K.P.; POGORELSKY,I.V.; SKARITKA,J.; VAN STEENBERGEN,A.; YAKIMENKO,V.; CLINE,D.B.; HE,P.; LIU,Y.; FIORITO,R.B.; PANTELL,R.H.; RULE,D.W.; SANDWEISS,J.

    1999-03-01

    Progress is reported on the Staged Electron Laser Acceleration (STELLA) experiment, which has been assembled on the BNL Accelerator Test Facility (ATF). The primary goal of STELLA is to demonstrate staging of the laser acceleration process by using the BNL inverse free electron laser (IFEL) as a prebuncher, which generates {approx} 1-{micro}m long microbunches, and accelerating these microbunches using an inverse Cerenkov acceleration (ICA) stage. Experimental runs are underway to recommission the IFEL and ICA systems separately, and reestablish the: microbunching process. Staging will then be examined by running both the IFEL and ICA systems together.

  4. Oxide bipolar electronics: materials, devices and circuits

    NASA Astrophysics Data System (ADS)

    Grundmann, Marius; Klüpfel, Fabian; Karsthof, Robert; Schlupp, Peter; Schein, Friedrich-Leonhard; Splith, Daniel; Yang, Chang; Bitter, Sofie; von Wenckstern, Holger

    2016-06-01

    We present the history of, and the latest progress in, the field of bipolar oxide thin film devices. As such we consider primarily pn-junctions in which at least one of the materials is a metal oxide semiconductor. A wide range of n-type and p-type oxides has been explored for the formation of such bipolar diodes. Since most oxide semiconductors are unipolar, challenges and opportunities exist with regard to the formation of heterojunction diodes and band lineups. Recently, various approaches have led to devices with high rectification, namely p-type ZnCo2O4 and NiO on n-type ZnO and amorphous zinc-tin-oxide. Subsequent bipolar devices and applications such as photodetectors, solar cells, junction field-effect transistors and integrated circuits like inverters and ring oscillators are discussed. The tremendous progress shows that bipolar oxide electronics has evolved from the exploration of various materials and heterostructures to the demonstration of functioning integrated circuits. Therefore a viable, facile and high performance technology is ready for further exploitation and performance optimization.

  5. Tumour progression and metastasis

    PubMed Central

    Arvelo, Francisco; Sojo, Felipe; Cotte, Carlos

    2016-01-01

    The two biological mechanisms that determine types of malignancy are infiltration and metastasis, for which tumour microenvironment plays a key role in developing and establishing the morphology, growth and invasiveness of a malignancy. The microenvironment is formed by complex tissue containing the extracellular matrix, tumour and non-tumour cells, a signalling network of cytokines, chemokines, growth factors, and proteases that control autocrine and paracrine communication among individual cells, facilitating tumour progression. During the development of the primary tumour, the tumour stroma and continuous genetic changes within the cells makes it possible for them to migrate, having to count on a pre-metastatic niche receptor that allows the tumour’s survival and distant growth. These niches are induced by factors produced by the primary tumour; if it is eradicated, the active niches become responsible for activating the latent disseminated cells. Due to the importance of these mechanisms, the strategies that develop tumour cells during tumour progression and the way in which the microenvironment influences the formation of metastasis are reviewed. It also suggests that the metastatic niche can be an ideal target for new treatments that make controlling metastasis possible. PMID:26913068

  6. Progressive supranuclear palsy.

    PubMed

    Golbe, Lawrence I

    2014-04-01

    Progressive supranuclear palsy is a disorder of tau protein aggregation. Its clinical spectrum is now known to be wider than originally described, with a phenotype resembling Parkinson disease accounting for a third of cases. However, at least half of the patients with PSP exhibit the classic bradykinesia with disproportionate postural instability, erect posture with nuchal rigidity, frontal behavioral and cognitive changes, vertical gaze palsy, and other disabling brainstem deficits. Nonmendelian genetic risk factors exist, but PSP is almost entirely sporadic, with a prevalence of five to six persons per 100,000, mean onset age of 63, and median survival of 7 years. Clinical diagnostic criteria with excellent specificity and a clinical rating scale sensitive to progression are available. Diagnosis remains clinical, although magnetic resonance imaging and cerebrospinal fluid measures are showing promise as early-stage screening tools. Multiple candidate neuroprotective medications have proven ineffective to date. Treatment remains supportive, although coenzyme Q-10 has shown preliminary symptomatic efficacy and levodopa may provide transient, modest benefit.

  7. Rapidly Progressive Dementia

    PubMed Central

    Geschwind, Michael D.

    2016-01-01

    Purpose of Review This article presents a practical and informative approach to the evaluation of a patient with a rapidly progressive dementia (RPD). Recent Findings Prion diseases are the prototypical causes of RPD, but reversible causes of RPD might mimic prion disease and should always be considered in a differential diagnosis. Aside from prion diseases, the most common causes of RPD are atypical presentations of other neurodegenerative disorders, curable disorders including autoimmune encephalopathies, as well as some infections, and neoplasms. Numerous recent case reports suggest dural arterial venous fistulas sometimes cause RPDs. Summary RPDs, in which patients typically develop dementia over weeks to months, require an alternative differential than the slowly progressive dementias that occur over a few years. Because of their rapid decline, patients with RPDs necessitate urgent evaluation and often require an extensive workup, typically with multiple tests being sent or performed concurrently. Jakob-Creutzfeldt disease, perhaps the prototypical RPD, is often the first diagnosis many neurologists consider when treating a patient with rapid cognitive decline. Many conditions other than prion disease, however, including numerous reversible or curable conditions, can present as an RPD. This chapter discusses some of the major etiologies for RPDs and offers an algorithm for diagnosis. PMID:27042906

  8. Progress in computational toxicology.

    PubMed

    Ekins, Sean

    2014-01-01

    Computational methods have been widely applied to toxicology across pharmaceutical, consumer product and environmental fields over the past decade. Progress in computational toxicology is now reviewed. A literature review was performed on computational models for hepatotoxicity (e.g. for drug-induced liver injury (DILI)), cardiotoxicity, renal toxicity and genotoxicity. In addition various publications have been highlighted that use machine learning methods. Several computational toxicology model datasets from past publications were used to compare Bayesian and Support Vector Machine (SVM) learning methods. The increasing amounts of data for defined toxicology endpoints have enabled machine learning models that have been increasingly used for predictions. It is shown that across many different models Bayesian and SVM perform similarly based on cross validation data. Considerable progress has been made in computational toxicology in a decade in both model development and availability of larger scale or 'big data' models. The future efforts in toxicology data generation will likely provide us with hundreds of thousands of compounds that are readily accessible for machine learning models. These models will cover relevant chemistry space for pharmaceutical, consumer product and environmental applications. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Tumour progression and metastasis.

    PubMed

    Arvelo, Francisco; Sojo, Felipe; Cotte, Carlos

    2016-01-01

    The two biological mechanisms that determine types of malignancy are infiltration and metastasis, for which tumour microenvironment plays a key role in developing and establishing the morphology, growth and invasiveness of a malignancy. The microenvironment is formed by complex tissue containing the extracellular matrix, tumour and non-tumour cells, a signalling network of cytokines, chemokines, growth factors, and proteases that control autocrine and paracrine communication among individual cells, facilitating tumour progression. During the development of the primary tumour, the tumour stroma and continuous genetic changes within the cells makes it possible for them to migrate, having to count on a pre-metastatic niche receptor that allows the tumour's survival and distant growth. These niches are induced by factors produced by the primary tumour; if it is eradicated, the active niches become responsible for activating the latent disseminated cells. Due to the importance of these mechanisms, the strategies that develop tumour cells during tumour progression and the way in which the microenvironment influences the formation of metastasis are reviewed. It also suggests that the metastatic niche can be an ideal target for new treatments that make controlling metastasis possible.

  10. [Progressive facial hemiatrophy].

    PubMed

    Naumbaev, A N; Sharipov, A Sh; Iakhontov, B V

    1991-01-01

    The authors describe a case of progressive facial hemiatrophy in a woman aged 26 years, coming from the Isfarin region of Tadzhikistan. The patient views herself as being ill for 14 years, since the moment of an epileptic attack with tonic and clonic convulsions. Approximately at the same time she noted a small dry ulcer on the left on the vertex. The ulcer slowly increased, followed by skin atrophy. The disease progressed for 4 to 5 years. At present to the left there are folds in the form of scars on the face. The skin is thinned, united with the bones in the frontal and parietal areas, the subcutaneous fat is atrophic. The lips and nose at the left are subatrophic. Negligible enophthalmos, hemiatrophy of the tongue at the left. Alopecia. A certain deterioration of memory and reduction of the critical attitude are recorded. The patient is in a state of euphoria. Left-sided anosmia. The left auricular floor is subatrophic, hearing is almost lacking. Diffuse elevation of the tendinous reflexes of the limbs on the left side. X-ray signs of osteoporosis of the bones of the cranial vault on the left.

  11. Oxidative stress inhibition and oxidant activity by fibrous clays.

    PubMed

    Cervini-Silva, Javiera; Nieto-Camacho, Antonio; Gómez-Vidales, Virginia

    2015-09-01

    Fibrous clays (sepiolite, palygorskite) are produced at 1.2m tonnes per year and have a wide range of industrial applications needing to replace long-fibre length asbestos. However, information on the beneficial effects of fibrous clays on health remains scarce. This paper reports on the effect of sepiolite (Vallecas, Spain) and palygorskite (Torrejón El Rubio, Spain) on cell damage via oxidative stress (determined as the progress of lipid peroxidation, LP). The extent of LP was assessed using the Thiobarbituric Acid Reactive Substances assay. The oxidant activity by fibrous clays was quantified using Electron-Paramagnetic Resonance. Sepiolite and palygorskite inhibited LP, whereby corresponding IC50 values were 6557±1024 and 4250±289μgmL(-1). As evidenced by dose-response experiments LP inhibition by palygorskite was surface-controlled. Fibrous clay surfaces did not stabilize HO species, except for suspensions containing 5000μgmL(-1). A strong oxidant (or weak anti-oxidant) activity favours the inhibition of LP by fibrous clays. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Oxidative stress and ageing.

    PubMed

    Birch-Machin, M A; Bowman, A

    2016-10-01

    Oxidative stress is the resultant damage due to redox imbalances (increase in destructive free radicals [reactive oxygen species (ROS)] and reduction in antioxidant protection/pathways) and is linked to ageing in many tissues including skin. In ageing skin there are bioenergetic differences between keratinocytes and fibroblasts which provide a potential ageing biomarker. The differences in skin bioenergy are part of the mitochondrial theory of ageing which remains one of the most widely accepted ageing theories describing subsequent increasing free radical generation. Mitochondria are the major source of cellular oxidative stress and form part of the vicious cycle theory of ageing. External and internal sources of oxidative stress include UVR/IR, pollution (environment), lifestyle (exercise and diet), alcohol and smoking all of which may potentially impact on skin although many exogenous actives and endogenous antioxidant defence systems have been described to help abrogate the increased stress. This also links to differences in skin cell types in terms of the UVR action spectrum for nuclear and mitochondrial DNA damage (the latter a previously described UVR biomarker in skin). Recent work associates bioenergy production and oxidative stress with pigment production thereby providing another additional potential avenue for targeted anti-ageing intervention in skin. This new data supporting the detrimental effects of the numerous wavelengths of UVR may aid in the development of cosmetic/sunscreen design to reduce the effects of photoageing. Recently, complex II of the mitochondrial electron transport chain appears to be more important than previously thought in the generation of free radicals (suggested predominantly by non-human studies). We investigated the relationship between complex II and ageing using human skin as a model tissue. The rate of complex II activity per unit of mitochondria was determined in fibroblasts and keratinocytes cultured from skin covering

  13. Lipid oxidation and improving the oxidative stability.

    PubMed

    Shahidi, Fereidoon; Zhong, Ying

    2010-11-01

    Lipids are a major component of food and important structural and functional constituents of cells in biological systems. However, this diverse group of substances is prone to oxidation through various pathways. Their oxidative stability depends on a number of intrinsic and extrinsic factors, including the unsaturation of their fatty acids, composition of minor components, environment conditions, delivery techniques and use of antioxidants, among others. Lipid oxidation has detrimental effects on both food quality and human health, and efforts must be made to minimize oxidation and improve oxidative stability of lipid products. Antioxidant strategy has been successfully employed in the food industry for quality preservation of the food products and in the medicinal industry for risk reduction of numerous oxidative stress-mediated diseases. This tutorial review will provide important knowledge about lipid oxidation, including the mechanism and factors involved in oxidation, as well as strategies for improving oxidative stability of lipids.

  14. Pycnogenol® and Centella Asiatica for asymptomatic atherosclerosis progression.

    PubMed

    Belcaro, G; Dugall, M; Hosoi, M; Ippolito, E; Cesarone, M; Luzzi, R; Cornelli, U; Ledda, A

    2014-02-01

    The aim of the study was to evaluate the effect of the nutritional supplements Pycnogenol and TECA (total triterpenic fraction of Centella Asiatica) on atherosclerosis progression in low-risk asymptomatic subjects with carotid or femoral non-stenosing plaques. This was an observational pilot substudy of the San Valentino epidemiological cardiovascular study. The study included 1363 subjects aged 45-60 without any conventional risk factors who had non stenosing atherosclerotic plaques (<50%) in at least one carotid or common femoral bifurcation, allocated into 6 groups: Group 1 (CONTROLS): management was based on education, exercise, diet and lifestyle changes. This same management plan was used in all groups; Group 2 Pycnogenol 50 mg/day; Group 3 Pycnogenol 100 mg/day; Group 4 Aspirin 100 mg/day or Ticlopidine 250 mg/day if intolerant to aspirin; Group 5 Aspirin 100 mg/day and Pycnogenol 100 mg/day; Group 6 Pycnogenol 100 mg/day plus TECA (total triterpenic fraction of Centella Asiatica) 100 mg/day. There was a six monthly follow-up up to 30 months. Plaque progression was assessed using the ultrasonic arterial score based on the arterial wall morphology and the number of plaques that progressed from the non-stenotic to the stenotic group. A secondary endpoint was to evaluate the changes in oxidative stress at baseline and at 30 months. The ultrasonic score increased significantly in groups 1, 2 and 4 but not in groups 3, 5 and 6 suggesting a beneficial effect of Pycnogenol 100 mg. The percentage of plaques that progressed from class IV to class V was 8.4% in group 2, 5.3% in group 3, 4% in group 5 and 1.1% in group 6 (P<0.0001) compared with 16.6% in group 4 (aspirin) and 21.3% in the control group suggesting a beneficial effect of Pycnogenol. The lowest rate of progression was in group 6 (Pycnogenol plus TECA). At 30 months, the oxidative stress in all the Pycnogenol groups was less than in the control group. The oxidative stress was lower in the Pycnogenol 100 mg

  15. Conceptions of Progress: How Is Progress Perceived? Mainstream versus Alternative Conceptions of Progress

    ERIC Educational Resources Information Center

    Itay, Anat

    2009-01-01

    Progress is a powerful political concept, encompassing different and sometimes contradictory conceptions. This paper examines the results of a survey on progress conducted at the OECD World Forum entitled "Measuring and Fostering the Progress of Societies" held in Istanbul in June 2007. First, a distinction is drawn between the two approaches to…

  16. Conceptions of Progress: How Is Progress Perceived? Mainstream versus Alternative Conceptions of Progress

    ERIC Educational Resources Information Center

    Itay, Anat

    2009-01-01

    Progress is a powerful political concept, encompassing different and sometimes contradictory conceptions. This paper examines the results of a survey on progress conducted at the OECD World Forum entitled "Measuring and Fostering the Progress of Societies" held in Istanbul in June 2007. First, a distinction is drawn between the two approaches to…

  17. Mesoporous Transition Metal Oxides for Supercapacitors

    PubMed Central

    Wang, Yan; Guo, Jin; Wang, Tingfeng; Shao, Junfeng; Wang, Dong; Yang, Ying-Wei

    2015-01-01

    Recently, transition metal oxides, such as ruthenium oxide (RuO2), manganese dioxide (MnO2), nickel oxides (NiO) and cobalt oxide (Co3O4), have been widely investigated as electrode materials for pseudo-capacitors. In particular, these metal oxides with mesoporous structures have become very hot nanomaterials in the field of supercapacitors owing to their large specific surface areas and suitable pore size distributions. The high specific capacities of these mesoporous metal oxides are resulted from the effective contacts between electrode materials and electrolytes as well as fast transportation of ions and electrons in the bulk of electrode and at the interface of electrode and electrolyte. During the past decade, many achievements on mesoporous transition metal oxides have been made. In this mini-review, we select several typical nanomaterials, such as RuO2, MnO2, NiO, Co3O4 and nickel cobaltite (NiCo2O4), and briefly summarize the recent research progress of these mesoporous transition metal oxides-based electrodes in the field of supercapacitors. PMID:28347088

  18. Oxide surfaces.

    PubMed

    Willmott, Phil

    2008-07-02

    Although the history of metal oxides and their surfaces goes back several decades to landmark studies, such as Mott and Peierls' explanation of electrical insulation in materials that are predicted in band theory to be conducting, or the observation by Morin of the superfast metal-to-insulator transition in vanadium dioxide, it is only in the last two decades that the world of condensed matter physics has become increasingly dominated by research into complex metal oxides. This has been driven most notably by an attempt to better understand and describe the fundamental physical processes behind their seemingly endless spectrum of properties, which in turn has also led to the discovery of novel phenomena, most prominently demonstrated by the discovery of high-temperature superconductivity in 1986, colossal magnetoresistance in 1994, and most recently, the formation of a two-dimensional conducting layer at the interface between two band insulators in 2004. One important reason why metal oxides, particularly in the form of thin films, have become such a popular subject for basic condensed matter research is that they offer a uniquely versatile materials base for the development of novel technologies. They owe this versatility both to the many different elemental combinations that lead to structurally similar forms, and also to the fact that in many cases, the strong interaction between the valence electrons means that there is a subtle interplay between structure and magnetic and electronic properties. This aspect has led in recent years to the birth or renaissance of research fields such as spintronics, orbital ordering, and multiferroics. Surfaces and interfaces are especially interesting in these strongly-correlated electron systems, where the rearrangement of electrical charge resulting from a minimization of surface or interfacial energy can have unexpected and often exciting consequences. Indeed, as the drive to miniaturize devices well below the micron size

  19. Kinetics of Supercritical Water Oxidation

    DTIC Science & Technology

    2007-11-02

    Donald R. Hardesty April 1 - June 30,1995 Project description: This project consists of experiments and theoretical modeling designed to improv...Washington. D.C., 4/95. D.R. Hardesty , "Kinetic Mechanisms of Supercritical Water Oxidation" presented at the FY95 In Progress Review. 5/95 Ft...McLean, 8300 MS9051 L. Rahn, 8351 MS9055 F. Tully, 8353 MS9056 G. Fisk, 8355 MS9052 D.R. Hardesty , 8361 Attn: Allendorf, S Allendorf, M

  20. Oxidation-driven surface dynamics on NiAl(100)

    PubMed Central

    Qin, Hailang; Chen, Xidong; Li, Liang; Sutter, Peter W.; Zhou, Guangwen

    2015-01-01

    Atomic steps, a defect common to all crystal surfaces, can play an important role in many physical and chemical processes. However, attempts to predict surface dynamics under nonequilibrium conditions are usually frustrated by poor knowledge of the atomic processes of surface motion arising from mass transport from/to surface steps. Using low-energy electron microscopy that spatially and temporally resolves oxide film growth during the oxidation of NiAl(100) we demonstrate that surface steps are impermeable to oxide film growth. The advancement of the oxide occurs exclusively on the same terrace and requires the coordinated migration of surface steps. The resulting piling up of surface steps ahead of the oxide growth front progressively impedes the oxide growth. This process is reversed during oxide decomposition. The migration of the substrate steps is found to be a surface-step version of the well-known Hele-Shaw problem, governed by detachment (attachment) of Al atoms at step edges induced by the oxide growth (decomposition). By comparing with the oxidation of NiAl(110) that exhibits unimpeded oxide film growth over substrate steps we suggest that whenever steps are the source of atoms used for oxide growth they limit the oxidation process; when atoms are supplied from the bulk, the oxidation rate is not limited by the motion of surface steps. PMID:25548155

  1. Oxidation-driven surface dynamics on NiAl(100)

    DOE PAGES

    Qin, Hailang; Chen, Xidong; Li, Liang; ...

    2014-12-29

    Atomic steps, a defect common to all crystal surfaces, can play an important role in many physical and chemical processes. However, attempts to predict surface dynamics under nonequilibrium conditions are usually frustrated by poor knowledge of the atomic processes of surface motion arising from mass transport from/to surface steps. Using low-energy electron microscopy that spatially and temporally resolves oxide film growth during the oxidation of NiAl(100) we demonstrate that surface steps are impermeable to oxide film growth. The advancement of the oxide occurs exclusively on the same terrace and requires the coordinated migration of surface steps. The resulting piling upmore » of surface steps ahead of the oxide growth front progressively impedes the oxide growth. This process is reversed during oxide decomposition. The migration of the substrate steps is found to be a surface-step version of the well-known Hele-Shaw problem, governed by detachment (attachment) of Al atoms at step edges induced by the oxide growth (decomposition). As a result, by comparing with the oxidation of NiAl(110) that exhibits unimpeded oxide film growth over substrate steps, we suggest that whenever steps are the source of atoms used for oxide growth they limit the oxidation process; when atoms are supplied from the bulk, the oxidation rate is not limited by the motion of surface steps.« less

  2. Oxidation-driven surface dynamics on NiAl(100)

    SciTech Connect

    Qin, Hailang; Chen, Xidong; Li, Liang; Sutter, Peter W.; Zhou, Guangwen

    2014-12-29

    Atomic steps, a defect common to all crystal surfaces, can play an important role in many physical and chemical processes. However, attempts to predict surface dynamics under nonequilibrium conditions are usually frustrated by poor knowledge of the atomic processes of surface motion arising from mass transport from/to surface steps. Using low-energy electron microscopy that spatially and temporally resolves oxide film growth during the oxidation of NiAl(100) we demonstrate that surface steps are impermeable to oxide film growth. The advancement of the oxide occurs exclusively on the same terrace and requires the coordinated migration of surface steps. The resulting piling up of surface steps ahead of the oxide growth front progressively impedes the oxide growth. This process is reversed during oxide decomposition. The migration of the substrate steps is found to be a surface-step version of the well-known Hele-Shaw problem, governed by detachment (attachment) of Al atoms at step edges induced by the oxide growth (decomposition). As a result, by comparing with the oxidation of NiAl(110) that exhibits unimpeded oxide film growth over substrate steps, we suggest that whenever steps are the source of atoms used for oxide growth they limit the oxidation process; when atoms are supplied from the bulk, the oxidation rate is not limited by the motion of surface steps.

  3. Oxidation-driven surface dynamics on NiAl(100)

    NASA Astrophysics Data System (ADS)

    Qin, Hailang; Chen, Xidong; Li, Liang; Sutter, Peter W.; Zhou, Guangwen

    2015-01-01

    Atomic steps, a defect common to all crystal surfaces, can play an important role in many physical and chemical processes. However, attempts to predict surface dynamics under nonequilibrium conditions are usually frustrated by poor knowledge of the atomic processes of surface motion arising from mass transport from/to surface steps. Using low-energy electron microscopy that spatially and temporally resolves oxide film growth during the oxidation of NiAl(100) we demonstrate that surface steps are impermeable to oxide film growth. The advancement of the oxide occurs exclusively on the same terrace and requires the coordinated migration of surface steps. The resulting piling up of surface steps ahead of the oxide growth front progressively impedes the oxide growth. This process is reversed during oxide decomposition. The migration of the substrate steps is found to be a surface-step version of the well-known Hele-Shaw problem, governed by detachment (attachment) of Al atoms at step edges induced by the oxide growth (decomposition). By comparing with the oxidation of NiAl(110) that exhibits unimpeded oxide film growth over substrate steps we suggest that whenever steps are the source of atoms used for oxide growth they limit the oxidation process; when atoms are supplied from the bulk, the oxidation rate is not limited by the motion of surface steps.

  4. 1992 PVUSA progress report

    SciTech Connect

    1992-12-31

    Photovoltaics for Utility Scale Applications (PVUSA) is a national public-private partnership that is assessing and demonstrating the viability of utility-scale photovoltaic (PV) electric generating systems. This report updates the progress of the PVUSA project, reviews the status and performance of the various PV installations during 1992, and summarizes key accomplishments and conclusions from work to date. Fall PV module costs and rising environmental pressures could make PV a significant source of large-scale power within the next decade. However, utility acceptance of this technology requires knowledge of PV operational characteristics in a utility system and confidence in predicting PV performance, reliability, and economics. PVUSA consists of two types of demonstrations: Emerging Module Technologies (EMTs), which are unproven but promising state-of-the-art PV technologies in 20-kW (nominal) arrays; and Utility Scale (US) systems, which represent more mature PV technologies in 200- to 500-kW (nominal) turnkey systems.

  5. Sphingosylphosphorylcholine in cancer progress

    PubMed Central

    Yue, Hong-Wei; Jing, Qing-Chuan; Liu, Ping-Ping; Liu, Jing; Li, Wen-Jing; Zhao, Jing

    2015-01-01

    Sphingosylphosphorylcholine (SPC) is a naturally occurring bioactive sphingolipid in blood plasma, metabolizing from the hydrolysis of the membrane sphingolipid. It has been shown to exert multifunctional role in cell physiological regulation either as an intracellular second messenger or as an extracellular agent through G protein coupled receptors (GPCRs). Because of elevated levels of SPC in malicious ascites of patients with cancer, the role of SPC in tumor progression has prompted wide interest. The factor was reported to affect the proliferation and/or migration of many cancer cells, including pancreatic cancer cells, epithelial ovarian carcinoma cells, rat C6 glioma cells, neuroblastoma cells, melanoma cells, and human leukemia cells. This review covers current knowledge of the role of SPC in tumor. PMID:26550104

  6. Progress in prokaryotic transcriptomics.

    PubMed

    Filiatrault, Melanie J

    2011-10-01

    Genome-wide expression studies transformed the field of transcriptomics and made it feasible to study global gene expression in extraordinary detail. These new methods have revealed an enhanced view of the transcriptional landscape and have yielded many biological insights. It is increasingly clear that the prokaryotic transcriptome is much more complex than once thought. Recent advances in microbial transcriptome analyses are highlighted in this review. Areas of progress include the development of optimized techniques that minimize the abundance of ribosomal RNAs in RNA samples as well as the development of novel methods to create transcriptome libraries. Advances such as these have led to a new emphasis in areas such as metatranscriptomics and single cell gene expression studies. Published by Elsevier Ltd.

  7. Progress in Induction Linacs

    SciTech Connect

    Caporaso, G J

    2000-09-27

    This presentation will be a broad survey of progress in induction technology over the past four years. Much work has been done on accelerators for hydrodynamic test radiography and other applications. Solid-state pulsers have been developed which can provide unprecedented flexibility and precision in pulse format and accelerating voltage for both ion and electron induction machines. Induction linacs can now be built which can operate with MHz repetition rates. Solid-state technology has also made possible the development of fast kickers for precision control of high current beams. New insulator technology has been developed which will improve conventional induction linacs in addition to enabling a new class of high gradient induction linacs.

  8. Progressive Band Selection

    NASA Technical Reports Server (NTRS)

    Fisher, Kevin; Chang, Chein-I

    2009-01-01

    Progressive band selection (PBS) reduces spectral redundancy without significant loss of information, thereby reducing hyperspectral image data volume and processing time. Used onboard a spacecraft, it can also reduce image downlink time. PBS prioritizes an image's spectral bands according to priority scores that measure their significance to a specific application. Then it uses one of three methods to select an appropriate number of the most useful bands. Key challenges for PBS include selecting an appropriate criterion to generate band priority scores, and determining how many bands should be retained in the reduced image. The image's Virtual Dimensionality (VD), once computed, is a reasonable estimate of the latter. We describe the major design details of PBS and test PBS in a land classification experiment.

  9. BRIF and CARIF progress

    NASA Astrophysics Data System (ADS)

    Liu, WeiPing; Li, ZhiHong; Bai, XiXiang; Wang, YouBao; Guo, Bing; Peng, ChaoHua; Yang, Yi; Su, Jun; Cui, BaoQun; Zhou, ShuHua; Zhu, ShengYun; Xia, HaiHong; Guan, XiaLing; Zeng, Sheng; Zhang, HuanQiao; Chen, YongShou; Tang, HongQing; Huang, Li; Feng, BeiYuan

    2011-08-01

    China Institute of Atomic Energy (CIAE) is currently constructing Beijing rare ion beam facility (BRIF) and is proposing China advanced rare ion beam facility (CARIF). This paper is aiming at introducing the progress of BRIF project and the conceptual design CARIF. The ISOL type facility BRIF under construction is composed of a 100 MeV 300 μA proton cyclotron, an ISOL with mass resolution of 20000, and a super-conducting LINAC of 2 MeV/q, and will be commissioned in 2013. CARIF facility proposed is planned to use both ISOL and PF techniques. It is based on a China advanced research reactor CARR that was critical, with ISOL separation of fission fragment, post acceleration to 150 MeV/u, and fragmentation of neutron-rich fission fragment beam like 132Sn. Such unique combination will allow CARIF to deliver beam intensity better than the best world facilities by more than one order of magnitude.

  10. Progress Towards International Repositories

    SciTech Connect

    McCombie, C.; Chapman, N.

    2002-02-27

    The nuclear fuel cycle is designed to be very international, with some specialist activities (e.g. fuel fabrication, reprocessing, etc.) being confined to a few countries. Nevertheless, political and public opposition has in the past been faced by proposals to internationalise the back-end of the cycle, in particular waste disposal. Attitudes, however, have been changing recently and there is now more acceptance of the general concept of shared repositories and of specific proposals such as that of Pangea. However, as for national facilities, progress towards implementation of shared repositories will be gradual. Moreover, the best vehicle for promoting the concept may not be a commercial type of organization. Consequently the Pangea project team are currently establishing a widely based Association for this purpose.

  11. Progress and Potential

    PubMed Central

    Haspel, Richard L.; Olsen, Randall J.; Berry, Anna; Hill, Charles E.; Pfeifer, John D.; Schrijver, Iris; Kaul, Karen L.

    2014-01-01

    Context Genomic medicine is revolutionizing patient care. Physicians in areas as diverse as oncology, obstetrics, and infectious disease have begun using next-generation sequencing assays as standard diagnostic tools. Objective To review the role of pathologists in genomic testing as well as current educational programs and future training needs in genomic pathology. Data Sources Published literature as well as personal experience based on committee membership and genomic pathology curricular design. Conclusion Pathologists, as the directors of the clinical laboratories, must be prepared to integrate genomic testing into their practice. The pathology community has made significant progress in genomics-related education. A continued coordinated and proactive effort will ensure a future vital role for pathologists in the evolving health care system and also the best possible patient care. PMID:24678680

  12. Progressing batch hydrolysis process

    DOEpatents

    Wright, J.D.

    1985-01-10

    A progressive batch hydrolysis process is disclosed for producing sugar from a lignocellulosic feedstock. It comprises passing a stream of dilute acid serially through a plurality of percolation hydrolysis reactors charged with feed stock, at a flow rate, temperature and pressure sufficient to substantially convert all the cellulose component of the feed stock to glucose. The cooled dilute acid stream containing glucose, after exiting the last percolation hydrolysis reactor, serially fed through a plurality of pre-hydrolysis percolation reactors, charged with said feedstock, at a flow rate, temperature and pressure sufficient to substantially convert all the hemicellulose component of said feedstock to glucose. The dilute acid stream containing glucose is cooled after it exits the last prehydrolysis reactor.

  13. Progressing batch hydrolysis process

    DOEpatents

    Wright, John D.

    1986-01-01

    A progressive batch hydrolysis process for producing sugar from a lignocellulosic feedstock, comprising passing a stream of dilute acid serially through a plurality of percolation hydrolysis reactors charged with said feedstock, at a flow rate, temperature and pressure sufficient to substantially convert all the cellulose component of the feedstock to glucose; cooling said dilute acid stream containing glucose, after exiting the last percolation hydrolysis reactor, then feeding said dilute acid stream serially through a plurality of prehydrolysis percolation reactors, charged with said feedstock, at a flow rate, temperature and pressure sufficient to substantially convert all the hemicellulose component of said feedstock to glucose; and cooling the dilute acid stream containing glucose after it exits the last prehydrolysis reactor.

  14. Water Oxidation Mechanisms of Metal Oxide Catalysts by Vibrational Spectroscopy of Transient Intermediates

    NASA Astrophysics Data System (ADS)

    Zhang, Miao; Frei, Heinz

    2017-05-01

    Water oxidation is an essential reaction of an artificial photosystem for solar fuel generation because it provides electrons needed to reduce carbon dioxide or protons to a fuel. Earth-abundant metal oxides are among the most attractive catalytic materials for this reaction because of their robustness and scalability, but their efficiency poses a challenge. Knowledge of catalytic surface intermediates gained by vibrational spectroscopy under reaction conditions plays a key role in uncovering kinetic bottlenecks and provides a basis for catalyst design improvements. Recent dynamic infrared and Raman studies reveal the molecular identity of transient surface intermediates of water oxidation on metal oxides. Combined with ultrafast infrared observations of how charges are delivered to active sites of the metal oxide catalyst and drive the multielectron reaction, spectroscopic advances are poised to play a key role in accelerating progress toward improved catalysts for artificial photosynthesis.

  15. Progressive familial intrahepatic cholestasis.

    PubMed

    Srivastava, Anshu

    2014-03-01

    Progressive familial intrahepatic cholestasis (PFIC) is a group of rare disorders which are caused by defect in bile secretion and present with intrahepatic cholestasis, usually in infancy and childhood. These are autosomal recessive in inheritance. The estimated incidence is about 1 per 50,000 to 1 per 100,000 births, although exact prevalence is not known. These diseases affect both the genders equally and have been reported from all geographical areas. Based on clinical presentation, laboratory findings, liver histology and genetic defect, these are broadly divided into three types-PFIC type 1, PFIC type 2 and PFIC type 3. The defect is in ATP8B1 gene encoding the FIC1 protein, ABCB 11 gene encoding BSEP protein and ABCB4 gene encoding MDR3 protein in PFIC1, 2 and 3 respectively. The basic defect is impaired bile salt secretion in PFIC1/2 whereas in PFIC3, it is reduced biliary phospholipid secretion. The main clinical presentation is in the form of cholestatic jaundice and pruritus. Serum gamma glutamyl transpeptidase (GGT) is normal in patients with PFIC1/2 while it is raised in patients with PFIC3. Treatment includes nutritional support (adequate calories, supplementation of fat soluble vitamins and medium chain triglycerides) and use of medications to relieve pruritus as initial therapy followed by biliary diversion procedures in selected patients. Ultimately liver transplantation is needed in most patients as they develop progressive liver fibrosis, cirrhosis and end stage liver disease. Due to the high risk of developing liver tumors in PFIC2 patients, monitoring is recommended from infancy. Mutation targeted pharmacotherapy, gene therapy and hepatocyte transplantation are being explored as future therapeutic options.

  16. Progressive Familial Intrahepatic Cholestasis

    PubMed Central

    Srivastava, Anshu

    2013-01-01

    Progressive familial intrahepatic cholestasis (PFIC) is a group of rare disorders which are caused by defect in bile secretion and present with intrahepatic cholestasis, usually in infancy and childhood. These are autosomal recessive in inheritance. The estimated incidence is about 1 per 50,000 to 1 per 100,000 births, although exact prevalence is not known. These diseases affect both the genders equally and have been reported from all geographical areas. Based on clinical presentation, laboratory findings, liver histology and genetic defect, these are broadly divided into three types—PFIC type 1, PFIC type 2 and PFIC type 3. The defect is in ATP8B1 gene encoding the FIC1 protein, ABCB 11 gene encoding BSEP protein and ABCB4 gene encoding MDR3 protein in PFIC1, 2 and 3 respectively. The basic defect is impaired bile salt secretion in PFIC1/2 whereas in PFIC3, it is reduced biliary phospholipid secretion. The main clinical presentation is in the form of cholestatic jaundice and pruritus. Serum gamma glutamyl transpeptidase (GGT) is normal in patients with PFIC1/2 while it is raised in patients with PFIC3. Treatment includes nutritional support (adequate calories, supplementation of fat soluble vitamins and medium chain triglycerides) and use of medications to relieve pruritus as initial therapy followed by biliary diversion procedures in selected patients. Ultimately liver transplantation is needed in most patients as they develop progressive liver fibrosis, cirrhosis and end stage liver disease. Due to the high risk of developing liver tumors in PFIC2 patients, monitoring is recommended from infancy. Mutation targeted pharmacotherapy, gene therapy and hepatocyte transplantation are being explored as future therapeutic options. PMID:25755532

  17. Correlation of Plasma Protein Carbonyls and C-Reactive Protein with GOLD Stage Progression in COPD Patients.

    PubMed

    Torres-Ramos, Yessica D; García-Guillen, María L; Olivares-Corichi, Ivonne M; Hicks, J J

    2009-04-14

    Oxidative stress plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). To investigate the correlation between the progression of COPD and plasma biomarkers of chronic inflammation and oxidative injury, blood samples were obtained from healthy volunteers (HV, n = 14) and stabilized COPD patients. The patients were divided into three groups according to their GOLD stage (II, n = 34; III, n = 18; IV, n = 20). C-reactive protein (CRP), protein carbonyls (PC), malondialdehyde (MDA), susceptible lipoperoxidation of plasma substrates (SLPS), and myeloperoxidase activity (MPO) were measured. The plasma concentration of SLPS was measured as the amount of MDA generated by a metal ion-catalyzed reaction in vitro. PC, SLPS, and CPR were increased significantly (p < 0.001) in COPD patients when compared to HV. MDA concentrations and MPO activities were not significantly different from those of the HV group. In conclusion, increased oxidation of lipids and proteins resulting in a progressive increase in the amount of total plasma carbonyls and oxidative stress the presence of oxidative stress during COPD progression, concomitant with an increased oxidation of lipids and proteins resulting in a progressive and significant increase in the amount of total carbonyls formed from lipid-derived aldehydes and direct amino acid side chain oxidation in plasma, may serve as a biomarker and independent monitor of COPD progression and oxidative stress injury.

  18. Correlation of Plasma Protein Carbonyls and C-Reactive Protein with GOLD Stage Progression in COPD Patients

    PubMed Central

    Torres-Ramos, Yessica D; García-Guillen, María L; Olivares-Corichi, Ivonne M; Hicks, J. J

    2009-01-01

    Oxidative stress plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). To investigate the correlation between the progression of COPD and plasma biomarkers of chronic inflammation and oxidative injury, blood samples were obtained from healthy volunteers (HV, n = 14) and stabilized COPD patients. The patients were divided into three groups according to their GOLD stage (II, n = 34; III, n = 18; IV, n = 20). C-reactive protein (CRP), protein carbonyls (PC), malondialdehyde (MDA), susceptible lipoperoxidation of plasma substrates (SLPS), and myeloperoxidase activity (MPO) were measured. The plasma concentration of SLPS was measured as the amount of MDA generated by a metal ion-catalyzed reaction in vitro. PC, SLPS, and CPR were increased significantly (p < 0.001) in COPD patients when compared to HV. MDA concentrations and MPO activities were not significantly different from those of the HV group. In conclusion, increased oxidation of lipids and proteins resulting in a progressive increase in the amount of total plasma carbonyls and oxidative stress the presence of oxidative stress during COPD progression, concomitant with an increased oxidation of lipids and proteins resulting in a progressive and significant increase in the amount of total carbonyls formed from lipid-derived aldehydes and direct amino acid side chain oxidation in plasma, may serve as a biomarker and independent monitor of COPD progression and oxidative stress injury. PMID:19461898

  19. Partial Oxidized Arsenene: Emerging Tunable Direct Bandgap Semiconductor

    PubMed Central

    Wang, Yu-Jiao; Zhou, Kai-Ge; Yu, Geliang; Zhong, Xing; Zhang, Hao-Li

    2016-01-01

    Arsenene, as a member of the Group V elemental two-dimensional materials appears on the horizon, has shown great prospects. However, its indirect bandgap limits the applications in optoelectronics. In this theoretical work, we reported that partial oxidation can tune the indirect bandgap of arsenene into the direct one. Attributed to the enthalpy decreasing linear to the oxygen ratio, partial oxidized arsenene can be controllably produced by the progressive oxidation under low temperature. Importantly, by increasing the oxygen content from 1O/18As to 18O/18As, the oxidation can narrow the direct bandgap of oxidized arsenene from 1.29 to 0.02 eV. The bandgap of partial oxidized arsenene is proportional to the oxygen content. Consequently, the partial oxidized arsenene with tunable direct bandgap has great potentials in the high efficient infra light emitter and photo-voltaic devices. PMID:27114052

  20. Oxidative Stress: A Promising Target for Chemoprevention

    PubMed Central

    John, AM Sashi Papu; Ankem, Murali K; Damodaran, Chendil

    2016-01-01

    Cancer is a leading cause of death worldwide, and treating advanced stages of cancer remains clinically challenging. Epidemiological studies have shown that oxidants and free radicals induced DNA damage is one of the predominant causative factors for cancer pathogenesis. Hence, oxidants are attractive targets for chemoprevention as well as therapy. Dietary agents are known to exert an anti-oxidant property which is one of the most efficient preventive strategy in cancer progression. In this article, we highlight dietary agents can potentially target oxidative stress, in turn delaying, preventing, or treating cancer development. Some of these agents are currently in use in basic research, while some have been launched successfully into clinical trials. PMID:27088073

  1. Ordered mesoporous metal oxides: synthesis and applications.

    PubMed

    Ren, Yu; Ma, Zhen; Bruce, Peter G

    2012-07-21

    Great progress has been made in the preparation and application of ordered mesoporous metal oxides during the past decade. However, the applications of these novel and interesting materials have not been reviewed comprehensively in the literature. In the current review we first describe different methods for the preparation of ordered mesoporous metal oxides; we then review their applications in energy conversion and storage, catalysis, sensing, adsorption and separation. The correlations between the textural properties of ordered mesoporous metal oxides and their specific performance are highlighted in different examples, including the rate of Li intercalation, sensing, and the magnetic properties. These results demonstrate that the mesoporosity has a direct impact on the properties and potential applications of such materials. Although the scope of the current review is limited to ordered mesoporous metal oxides, we believe that the information may be useful for those working in a number of fields.

  2. Fatty Acid Oxidation Disorders

    MedlinePlus

    ... other health conditions > Fatty acid oxidation disorders Fatty acid oxidation disorders E-mail to a friend Please ... these disorders, go to genetests.org . What fatty acid oxidation disorders are tested for in newborn screening? ...

  3. Polymerization of Ethylene Oxide, Propylene Oxide, and Other Alkylene Oxides: Synthesis, Novel Polymer Architectures, and Bioconjugation.

    PubMed

    Herzberger, Jana; Niederer, Kerstin; Pohlit, Hannah; Seiwert, Jan; Worm, Matthias; Wurm, Frederik R; Frey, Holger

    2016-02-24

    The review summarizes current trends and developments in the polymerization of alkylene oxides in the last two decades since 1995, with a particular focus on the most important epoxide monomers ethylene oxide (EO), propylene oxide (PO), and butylene oxide (BO). Classical synthetic pathways, i.e., anionic polymerization, coordination polymerization, and cationic polymerization of epoxides (oxiranes), are briefly reviewed. The main focus of the review lies on more recent and in some cases metal-free methods for epoxide polymerization, i.e., the activated monomer strategy, the use of organocatalysts, such as N-heterocyclic carbenes (NHCs) and N-heterocyclic olefins (NHOs) as well as phosphazene bases. In addition, the commercially relevant double-metal cyanide (DMC) catalyst systems are discussed. Besides the synthetic progress, new types of multifunctional linear PEG (mf-PEG) and PPO structures accessible by copolymerization of EO or PO with functional epoxide comonomers are presented as well as complex branched, hyperbranched, and dendrimer like polyethers. Amphiphilic block copolymers based on PEO and PPO (Poloxamers and Pluronics) and advances in the area of PEGylation as the most important bioconjugation strategy are also summarized. With the ever growing toolbox for epoxide polymerization, a "polyether universe" may be envisaged that in its structural diversity parallels the immense variety of structural options available for polymers based on vinyl monomers with a purely carbon-based backbone.

  4. Perovskite oxide nanowires: synthesis, property and structural characterization.

    PubMed

    Zhu, Xinhua; Liu, Zhiguo; Ming, Naiben

    2010-07-01

    Perovskite oxide materials display a wide spectrum of functional properties, including switchable polarization, piezoelectricity, pyroelectricity, and non-linear dielectric behavior. These properties are indispensable for application in electronic devices such as non-volatile memories, sensors, microactuators, infrared detectors, microwave phase filters, and so on. Recent advances in science and technology of perovskite oxide materials have resulted in the feature sizes of perovskite oxides-based electronic devices entering into nanoscale dimensions. At nanoscale perovskite oxide materials exhibit a pronounced size effect manifesting itself in a significant deviation of the properties of low-dimensional structures from the bulk and film counterparts. In the last decade low-dimensional perovskite nanosized oxides have been received much attention because of their superior physical and chemical properties. Among them, perovskite oxide nanowires are especially attractive for nanoscience studies and nanotechnology applications. Compared to other low-dimensional perovskite oxide systems, perovskite oxide nanowires are not only used as the building blocks of future nanodevices, but also they offer fundamental scientific opportunities for investigating the intrinsic size effects of physical properties. In the recent years, much progress has been made both in synthesis and physical property testing of perovskite oxide nanowires, which have a profound impact on the nanoelectronics. In this work, an overview of the state of art in perovskite oxide nanowires is presented, which covers their synthesis, property, and structural characterization. In the first part, the recent literatures for fabricating perovskite oxide nanowires with promising features, are critically reviewed. The second part deals with the recent advances on the physical property testing of perovskite oxide nanowires. The third part summarizes the recent progress on microstructural characterizations of

  5. Progress 28 supply vehicle docking

    NASA Image and Video Library

    2008-02-07

    ISS016-E-027827 (7 Feb. 2008) --- An unpiloted Progress supply vehicle approaches the International Space Station. Progress 28 resupply craft launched at 7:03 a.m. (CST) on Feb. 5, 2008 from the Baikonur Cosmodrome in Kazakhstan to deliver more than 2.5 tons of food, fuel, oxygen and other supplies to the Expedition 16 crewmembers onboard the station. Progress automatically docked to the Pirs Docking Compartment at 8:30 a.m. (CST) on Feb. 7.

  6. Progress 28 supply vehicle approach

    NASA Image and Video Library

    2008-02-07

    ISS016-E-027820 (7 Feb. 2008) --- An unpiloted Progress supply vehicle approaches the International Space Station. Progress 28 resupply craft launched at 7:03 a.m. (CST) on Feb. 5, 2008 from the Baikonur Cosmodrome in Kazakhstan to deliver more than 2.5 tons of food, fuel, oxygen and other supplies to the Expedition 16 crewmembers onboard the station. Progress automatically docked to the Pirs Docking Compartment at 8:30 a.m. (CST) on Feb. 7.

  7. Progressive familial intrahepatic cholestasis.

    PubMed

    Jacquemin, Emmanuel

    2012-09-01

    Progressive familial intrahepatic cholestasis (PFIC) refers to a heterogeneous group of autosomal-recessive disorders of childhood that disrupt bile formation and present with cholestasis of hepatocellular origin. The exact prevalence remains unknown, but the estimated incidence varies between 1/50,000 and 1/100,000 births. Three types of PFIC have been identified and associated with mutations in hepatocellular transport-system genes involved in bile formation. PFIC1 and PFIC2 usually appear in the first months of life, whereas onset of PFIC3 may arise later in infancy, in childhood or even during young adulthood. The main clinical manifestations include cholestasis, pruritus and jaundice. PFIC patients usually develop fibrosis and end-stage liver disease before adulthood. Serum gamma-glutamyltransferase (GGT) activity is normal in PFIC1 and PFIC2 patients, but is elevated in PFIC3 patients. Both PFIC1 and PFIC2 are caused by impaired bile salt secretion due to defects in ATP8B1 encoding the FIC1 protein and in ABCB11 encoding bile salt export pump (BSEP) protein, respectively. Defects in ABCB4, encoding multidrug resistance 3 protein (MDR3), impair biliary phospholipid secretion, resulting in PFIC3. Diagnosis is based on clinical manifestations, liver ultrasonography, cholangiography and liver histology, as well as on specific tests to exclude other causes of childhood cholestasis. MDR3 and BSEP liver immunostaining, and analysis of biliary lipid composition should help to select PFIC candidates for whom genotyping could be proposed to confirm the diagnosis. Antenatal diagnosis may be proposed for affected families in which a mutation has been identified. Ursodeoxycholic acid (UDCA) therapy should be initiated in all patients to prevent liver damage. In some PFIC1 and PFIC2 patients, biliary diversion may also relieve pruritus and slow disease progression. However, most PFIC patients are ultimately candidates for liver transplantation. Monitoring of liver tumors

  8. Progressive familial intrahepatic cholestasis.

    PubMed

    Davit-Spraul, Anne; Gonzales, Emmanuel; Baussan, Christiane; Jacquemin, Emmanuel

    2009-01-08

    Progressive familial intrahepatic cholestasis (PFIC) refers to heterogeneous group of autosomal recessive disorders of childhood that disrupt bile formation and present with cholestasis of hepatocellular origin. The exact prevalence remains unknown, but the estimated incidence varies between 1/50,000 and 1/100,000 births. Three types of PFIC have been identified and related to mutations in hepatocellular transport system genes involved in bile formation. PFIC1 and PFIC2 usually appear in the first months of life, whereas onset of PFIC3 may also occur later in infancy, in childhood or even during young adulthood. Main clinical manifestations include cholestasis, pruritus and jaundice. PFIC patients usually develop fibrosis and end-stage liver disease before adulthood. Serum gamma-glutamyltransferase (GGT) activity is normal in PFIC1 and PFIC2 patients, but is elevated in PFIC3 patients. Both PFIC1 and PFIC2 are caused by impaired bile salt secretion due respectively to defects in ATP8B1 encoding the FIC1 protein, and in ABCB11 encoding the bile salt export pump protein (BSEP). Defects in ABCB4, encoding the multi-drug resistant 3 protein (MDR3), impair biliary phospholipid secretion resulting in PFIC3. Diagnosis is based on clinical manifestations, liver ultrasonography, cholangiography and liver histology, as well as on specific tests for excluding other causes of childhood cholestasis. MDR3 and BSEP liver immunostaining, and analysis of biliary lipid composition should help to select PFIC candidates in whom genotyping could be proposed to confirm the diagnosis. Antenatal diagnosis can be proposed for affected families in which a mutation has been identified. Ursodeoxycholic acid (UDCA) therapy should be initiated in all patients to prevent liver damage. In some PFIC1 or PFIC2 patients, biliary diversion can also relieve pruritus and slow disease progression. However, most PFIC patients are ultimately candidates for liver transplantation. Monitoring of

  9. Dynamically prioritized progressive transmission

    NASA Astrophysics Data System (ADS)

    Blanford, Ronald

    1992-04-01

    Retrieval of image data from a centralized database may be subject to bandwidth limitations, whether due to a low-bandwidth communications link or to contention from simultaneous accesses over a high-bandwidth link. Progressive transmission can alleviate this problem by encoding image data so that any prefix of the data stream approximates the complete image at a coarse level of resolution. The longer the prefix, the finer the resolution. In many cases, as little at 1 percent of the image data may be sufficient to decide whether to discard the image, to permit the retrieval to continue, or to restrict retrieval to a subsection of the image. Our approach treats resolution not as a fixed attribute of the image, but rather as a resource which may be allocated to portions of the image at the direction of a user-specified priority function. The default priority function minimizes error by allocating more resolution to regions of high variance. The user may also point to regions of interest requesting priority transmission. More advanced target recognition strategies may be incorporated at the user's discretion. Multispectral imagery is supported. The user engineering implications are profounded. There is immediate response to a query that might otherwise take minutes to complete. The data is transmitted in small increments so that no single user dominates the communications bandwidth. The user-directed improvement means that bandwidth is focused on interesting information. The user may continue working with the first coarse approximations while further image data is still arriving. The algorithm has been implemented in C on Sun, Silicon Graphics, and NeXT workstations, and in Lisp on a Symbolics. Transmission speeds reach as high as 60,000 baud using a Sparc or 68040 processor when storing data to memory; somewhat less if also updating a graphical display. The memory requirements are roughly five bytes per image pixel. Both computational and memory costs may be reduced

  10. Progress in advanced high temperature turbine materials, coatings, and technology

    NASA Technical Reports Server (NTRS)

    Freche, J. C.; Ault, G. M.

    1978-01-01

    Advanced materials, coatings, and cooling technology is assessed in terms of improved aircraft turbine engine performance. High cycle operating temperatures, lighter structural components, and adequate resistance to the various environmental factors associated with aircraft gas turbine engines are among the factors considered. Emphasis is placed on progress in development of high temperature materials for coating protection against oxidation, hot corrosion and erosion, and in turbine cooling technology. Specific topics discussed include metal matrix composites, superalloys, directionally solidified eutectics, and ceramics.

  11. EDITORIAL: Oxide semiconductors

    NASA Astrophysics Data System (ADS)

    Kawasaki, M.; Makino, T.

    2005-04-01

    non-equilibrium growth has rekindled the recent extensive investigation and progress in the field of ZnO epitaxy. In this special issue, Ohtomo and Tsukazaki, Cho et al, and Yi et al, respectively, describe the various fabrication processes such as pulsed laser deposition, molecular-beam epitaxy and metal-organic chemical vapour deposition. It should be noted that the last work among the above-mentioned papers has the potential to pave the way to nano-technology based on ZnO. This material has found other important applications as well, such as transparent conducting oxides (TCO). This field has a long research history, as is reviewed by Minami. Relatively speaking, ZnO was one of the earliest crystals (after Si, Ge, and InSb) to be prepared in a pure form, and the resultant long research history has given rise to the availability of large-area substrates. Recent progress in this topic is explained by two representative groups of authors in this field: Nause and Nemeth at Cermet Inc., and Maeda et al at Tokyo Denpa Co. Ltd. In order to overcome the bottleneck of p-type conduction and control the material's properties, a clear understanding of the physical processes in ZnO is necessary. Look et al are known as the first group to report on the growth and properties of p-type ZnO layers with a valid and reasonable set of experimental data (2002 Appl. Phys. Lett. 81 1830). Here, Look contributes a more comprehensive review to this issue. Optical studies on single crystals were conducted and are reviewed here by Meyer et al and Chichibu et al. Band-gap engineering and fabrication of heterojunction or quantum structures are important technological issues. It should be emphasized that by choosing an appropriate set of concentrations (x and y), perfect lattice-matching between MgxZn1-xO and CdyZn1-yO can be attained (Makino T et al 2001 Appl. Phys. Lett. 78 1237). Exciton properties of multiple quantum well structures are reported by Makino et al in this issue. Other than

  12. Using Learning Progressions to Monitor Progress across Grades

    ERIC Educational Resources Information Center

    Hess, Karin K.

    2010-01-01

    Learning progressions (LPs)--descriptive continuums of how students develop and demonstrate more sophisticated understanding over time--have become an increasingly important tool in today's science classrooms. Here the author discusses some of the research behind learning progressions and presents The Science Inquiry Profile for PreK-4. This is a…

  13. Progress in Ultrafast Photonics

    NASA Astrophysics Data System (ADS)

    Kamiya, Takeshi; Tsuchiya, Masahiro

    2005-08-01

    Recent progress in ultrafast photonics is reviewed with special emphasis on the research and development activities in Japanese research institutions in the field of optical communication and related measurement technologies. After summarizing the physical natures of ultrashort optical pulses, selected topics are reviewed on such as (1) ultrahigh-bit-rate optical communication employing the combination of optical time division multiplexing (OTDM) and wavelength division multiplexing (WDM), (2) optical components for ultrafast photonics with emphasis on all optical switches including semiconductor optical amplifiers, cascaded second order frequency converters, semiconductor saturable absorber switches, organic dye saturable absorber switches and bistable semiconductor lasers, (3) microwave photonics, emphasizing millimeter-wave/photonic communication technologies, and (4) high-speed optical measurements featuring both compact femtosecond pulse source development and rf magnetic field imaging. Some comments on the future prospect of ultrafast photonics are also given. It is concluded that in order to bring the powerful and versatile capability of ultrafast photonics into the real world, further collaboration between photonics specialists and production engineers/information specialists is strongly desired.

  14. IPY Progress and Prospects

    NASA Astrophysics Data System (ADS)

    Carlson, D.

    2008-12-01

    We can summarize the IPY goals as: (a) make major advances in polar knowledge and understanding; (b) leave a legacy of new or enhanced observational systems, facilities and infrastructure; (c) excite a new generation of polar scientists and engineers, and (d) elicit exceptional interest and participation from polar residents, schoolchildren, the general public, and decision-makers, worldwide. This talk reports on the progress and prospects in each of those areas from an overall international view; separate talks will describe details of future researcher and the IPY outreach efforts. To achieve major advances in knowledge, IPY has entrained the intellectual resources of thousands of scientists, many more than expected, often from 'non- polar' nations, and representing an unprecedented breadth of scientific specialties; integration of those efforts across disciplines to achieve integrated system-level understanding remains a substantial challenge. Many national and international organizations prepare plans to sustain new and improved observational systems, but clear outcomes and the necessary resources remain elusive. International outreach networks gradually build breadth and strength, largely through IPY Polar Science Days and other internationally- coordinated IPY events. A new Association of Polar Early Career Scientists (APECS) devotes talent and energy to shaping the future of polar research. These activities and networks may, with time and with continued international coordination, achieve an exceptional level of interest and participation. In all areas, much work remains.

  15. PVUSA progress report, 1991

    SciTech Connect

    Ellyn, W.; Jennings, C.

    1991-12-31

    Photovoltaics for Utility Scale Applications (PVUSA) is a national public-private partnership that is assessing and demonstrating the viability of utility-scale photovoltaic (PV) electric generating systems. PVUSA participants include Pacific Gas & Electric (PG&E), the US Department of Energy (DOE), the Electric Power Research Institute (EPRI), the California Energy Commission (CEC), and eight utilities and other agencies. This report updates the progress of the PVUSA project, reviews the status and performance of the various PV installations during 1991, and summarizes key findings and conclusions from work to date. PVUSA offers utilities hands-on experience needed to evaluate and utilize maturing PV technology. The project also provides manufacturers a test bed for their products, encourages technology improvement and cost reductions in PV modules and other system components, and establishes communication channels between utilities and the PV industry. The project consists of two types of demonstrations: Emerging Module Technology (EMT) arrays, which are unproven but promising state-of-the-art PV technologies in 20-kW (nominal) arrays; and Utility Scale (US) systems, which represent more mature PV technologies in 200- to 500-kW turnkey systems.

  16. W7-X Progress

    SciTech Connect

    Gasparotto, M.; Erckmann, V.; Gardebrecht, W.; Rummel, Th.; Schauer, F.; Wanner, M.; Wegener, L.

    2005-04-15

    The WENDELSTEIN 7-X stellarator (W7-X) is the next step device in the stellarator line of IPP and is presently under construction at the Greifswald branch institute. The experiment aims at demonstrating the steady state capability of a stellarator machine at reactor relevant parameters. An important feature of W7-X is the high geometrical accuracy of the magnetic configuration which implies tight tolerances in the construction and assembly phases. The magnetic system consists of 50 non planar and 20 planar superconducting coils. Critical components are the coil support elements connecting the coil to the central mechanical structure and the inter-coil elements connecting the coils one to the other. Efficient thermal insulation of the superconducting coils is achieved by high vacuum and multi-layer insulation. The plasma vessel is composed of 10 half-modules welded together during the assembly phase. A 10 MW ECRH system with CW-capability operation at 140 GHz is required to meet the scientific objective of W7-X.The paper will report the recent progress on W7-X with particular emphasis on the components where high technology solutions have been applied.

  17. Progressive myoclonic epilepsies

    PubMed Central

    Michelucci, Roberto; Canafoglia, Laura; Striano, Pasquale; Gambardella, Antonio; Magaudda, Adriana; Tinuper, Paolo; La Neve, Angela; Ferlazzo, Edoardo; Gobbi, Giuseppe; Giallonardo, Anna Teresa; Capovilla, Giuseppe; Visani, Elisa; Panzica, Ferruccio; Avanzini, Giuliano; Tassinari, Carlo Alberto; Bianchi, Amedeo; Zara, Federico

    2014-01-01

    Objective: To define the clinical spectrum and etiology of progressive myoclonic epilepsies (PMEs) in Italy using a database developed by the Genetics Commission of the Italian League against Epilepsy. Methods: We collected clinical and laboratory data from patients referred to 25 Italian epilepsy centers regardless of whether a positive causative factor was identified. PMEs of undetermined origins were grouped using 2-step cluster analysis. Results: We collected clinical data from 204 patients, including 77 with a diagnosis of Unverricht-Lundborg disease and 37 with a diagnosis of Lafora body disease; 31 patients had PMEs due to rarer genetic causes, mainly neuronal ceroid lipofuscinoses. Two more patients had celiac disease. Despite extensive investigation, we found no definitive etiology for 57 patients. Cluster analysis indicated that these patients could be grouped into 2 clusters defined by age at disease onset, age at myoclonus onset, previous psychomotor delay, seizure characteristics, photosensitivity, associated signs other than those included in the cardinal definition of PME, and pathologic MRI findings. Conclusions: Information concerning the distribution of different genetic causes of PMEs may provide a framework for an updated diagnostic workup. Phenotypes of the patients with PME of undetermined cause varied widely. The presence of separate clusters suggests that novel forms of PME are yet to be clinically and genetically characterized. PMID:24384641

  18. Progressive familial intrahepatic cholestasis.

    PubMed

    Jacquemin, E

    1999-06-01

    Progressive familial intrahepatic cholestasis (PFIC), also known as Byler disease, is an inherited disorder of childhood in which cholestasis of hepatocellular origin often presents in the neonatal period and leads to death from liver failure before adolescence. The pattern of appearance of affected children within families is consistent with autosomal recessive inheritance. Several studies have provided support for the heterogeneity of this clinical entity suggesting the existence of different types due to different disorders affecting the hepatocyte and related to defects of bile acid secretion or bile acid metabolism. Recent molecular and genetic studies have identified genes responsible for three types of PFIC and have shown that PFIC was related to mutations in hepatocellular transport system genes involved in bile formation. These findings now provide specific diagnostic tools for the investigation of children with PFIC and should allow prenatal diagnosis in the future. Genotype-phenotype correlations performed in patients treated with ursodeoxycholic acid or biliary diversion should allow those PFIC patients who could benefit from these therapies to be precisely identified. In the future, other therapies, such as cell and gene therapies, might be considered and could also represent an alternative to liver transplantation.

  19. Progressive familial intrahepatic cholestasis.

    PubMed

    Cavestro, Giulia Martina; Frulloni, Luca; Cerati, Elena; Ribeiro, Luciana Andrea; Corrente, Vincenzo; Sianesi, Mario; Franzè, Angelo; Di Mario, Francesco

    2002-01-01

    Progressive familial intrahepatic cholestasis (PFIC) is a heterogeneous group of autosomal recessive childhood cholestasis of hepatocellular origin. PFIC 1, also known as Byler disease, was first described in Amish kindred. It is characterized by cholestasis often arising in the neonatal period and it leads to death due to liver failure. PFIC 1, like Benign Recurrent Intrahepatic Cholestasis (BRIC) which is the benign form of the same disease, recognizes mutations in the ATP8B1 gene. PFIC 2 disease is clinically similar to PFIC 1 but it has a different gene mutation causing a defect in the Bile Salt Export Pump (BSEP), exclusively expressed in the liver and involved in the canalicular secretion of bile acids. PFIC 3 usually appears later in life and it has a higher risk of portal hypertension, gastrointestinal bleeding and liver failure. This particular form of disease (the only one with high serum values of g-glutamil transpeptidase), is associated to a genetic defect in the class III multidrug resistance protein (MDR). External biliary diversion and ursodeoxycholic acid therapy, should be considered as the initial therapy in these patients, even if liver transplantation still seems to be the only solution for most patients.

  20. Progress in neuromorphic photonics

    NASA Astrophysics Data System (ADS)

    Ferreira de Lima, Thomas; Shastri, Bhavin J.; Tait, Alexander N.; Nahmias, Mitchell A.; Prucnal, Paul R.

    2017-03-01

    As society's appetite for information continues to grow, so does our need to process this information with increasing speed and versatility. Many believe that the one-size-fits-all solution of digital electronics is becoming a limiting factor in certain areas such as data links, cognitive radio, and ultrafast control. Analog photonic devices have found relatively simple signal processing niches where electronics can no longer provide sufficient speed and reconfigurability. Recently, the landscape for commercially manufacturable photonic chips has been changing rapidly and now promises to achieve economies of scale previously enjoyed solely by microelectronics. By bridging the mathematical prowess of artificial neural networks to the underlying physics of optoelectronic devices, neuromorphic photonics could breach new domains of information processing demanding significant complexity, low cost, and unmatched speed. In this article, we review the progress in neuromorphic photonics, focusing on photonic integrated devices. The challenges and design rules for optoelectronic instantiation of artificial neurons are presented. The proposed photonic architecture revolves around the processing network node composed of two parts: a nonlinear element and a network interface. We then survey excitable lasers in the recent literature as candidates for the nonlinear node and microring-resonator weight banks as the network interface. Finally, we compare metrics between neuromorphic electronics and neuromorphic photonics and discuss potential applications.

  1. Technical progress report

    SciTech Connect

    1996-10-01

    This report summarizes experimental and theoretical work in basic nuclear physics carried out between October 1, 1995, the closing of our last Progress Report, and September 30, 1996 at the Nuclear Physics Laboratory of the University of Colorado, Boulder, under contracts DE-FG03-93ER-40774 and DE-FG03-95ER-40913 with the United States Department of Energy. The experimental contract supports broadly-based experimental research in intermediate energy nuclear physics. This report includes results from studies of Elementary Systems involving the study of the structure of the nucleon via polarized high-energy positron scattering (the HERMES experiment) and lower energy pion scattering from both polarized and unpolarized nucleon targets. Results from pion- and kaon-induced reactions in a variety of nuclear systems are reported under the section heading Meson Reactions; the impact of these and other results on understanding the nucleus is presented in the Nuclear Structure section. In addition, new results from scattering of high-energy electrons (from CEBAF/TJNAF) and pions (from KEK) from a broad range of nuclei are reported in the section on Incoherent Reactions. Finally, the development and performance of detectors produced by the laboratory are described in the section titled Instrumentation.

  2. 1993 PVUSA progress report

    SciTech Connect

    1993-12-31

    Photovoltaics for Utility Scale Applications (PVUSA) is a national public-private partnership that is assessing and demonstrating the viability of utility-scale photovoltaic (PV) electric generation systems and recent developments in module technology. This report updates the progress of the PVUSA project, review the status and performance of all PV installations during 1993, and summarizes key accomplishments and conclusions for the year. The PVUSA project has five objectives designed to narrow the gap between a large utility industry that is unfamiliar with PV, and a small PV industry that is aware of a potentially large utility market but unfamiliar with how to meet its requirements. The objectives are: to evaluate the performance, reliability, and cost of promising PV modules and balance-of-system (BOS) components side-by-side at a single location; to assess PV system operation and maintenance (O and M) in a utility setting; to compare PV technologies in diverse geographic areas; to provide US utilities with hands-on experience in designing, procuring, and operating PV systems; and to document and disseminate knowledge gained from the project.

  3. Progress of AMOLED technology

    NASA Astrophysics Data System (ADS)

    Park, Joon Young

    2005-01-01

    We report the technical progress of AMOLED at Samsung SDI, comparing with other technologies. We introduce the voltage-compensational TFT circuit structure to improve the brightness uniformity of AMOLED, which is based on the low temperature poly-silicon. We have developed not only small molecule emitters (phosphorescence and fluorescence) but also polymeric emitters. From red and green phosphors, we achieved longer lifetime and higher efficiency than fluorophors. With the shadow mask patterning and the bottom-emission structure, 20,000-hour lifetime of QCIF device and the power consumption less than 150 mW at 100 cd/m2 (30% on condition) were obtained. In the case of the top-emission structure, we could get high efficiency also by maximizing the light out-coupling efficiency and enhance the color purity to the level of the NTSC. We have developed another patterning technology, "LITI: Laser Induced Thermal Imaging" and fabricated 17-inch full color AMOLED, which is the largest AMOLED based on the low temperature poly-Silicon.

  4. Quarterly Progress Report

    SciTech Connect

    David Gray; Glen Tomlinson

    1998-11-12

    The Federal Energy Technology Center (FETC) at Pittsburgh contracted with the MJTRE Corporation to perform Research Guidance Studies that will assist the Center and other relevant offices in the Department of Energy in evaluating and prioritizing research in the areas of coal and natural gas conversion. MITRE was reorganized in December 1995, which resulted in the formation of Mitretek Systems Inc. Mitretek has been performing this work on MITRE's behalf awaiting completion of contract novation to Mitretek. The contract was novated in February 1998 to Mitretek Systems. The overall objectives of this contract are to provide support to DOE in the following areas: (1) technical and economic analyses of current and future coal-based energy conversion technologies and other similar emerging technologies such as coal-waste coprocessing, natural gas conversion, and biomass conversion technologies for the production of fuels, chemicals and electric power,(2) monitor progress in these technologies with respect to technical, economic, and environmental impact (including climate change), (3) conduct specific and generic project economic and technical feasibility studies based on these technologies, (4) identify long-range R&D areas that have the greatest potential for process improvements, and (5) investigate optimum configurations and associated costs for production of high quality energy products via refining and their performance in end-use applications.

  5. Nuclear chemistry progress report

    SciTech Connect

    Viola, V.E.; Kwiatkowski, K.

    1993-08-01

    This is the annual progress report for the Indiana University nuclear chemistry program for the 1992/1993 year. Accomplishments include the construction, testing, and initial experimental runs of the Indiana Silicon Sphere (ISiS) 4{pi} charged particle detector. ISiS is designed to study energy dissipation and multifragmentation phenomena in light-ion-induced nuclear reactions at medium-to-high energies. Its second test run was to examine 3.6 GeV {sup 3}He beam reactions at Laboratoire National Saturne (LNS) in Saclay. The development and deployment of this system has occupied a great deal of the groups effort this reporting period. Additional work includes: calculations of isotopic IMF yields in the {sup 4}He + {sup 116,124}Sn reaction; cross sections for A = 6 - 30 fragments from the {sup 4}He + {sup 28}Si reaction at 117 and 198 MeV; charging effects of passivated silicon detectors; neck emission of intermediate-mass fragments in the fission of hot heavy nuclei.

  6. Oxidative stress and the ageing endocrine system.

    PubMed

    Vitale, Giovanni; Salvioli, Stefano; Franceschi, Claudio

    2013-04-01

    Ageing is a process characterized by a progressive decline in cellular function, organismal fitness and increased risk of age-related diseases and death. Several hundred theories have attempted to explain this phenomenon. One of the most popular is the 'oxidative stress theory', originally termed the 'free radical theory'. The endocrine system seems to have a role in the modulation of oxidative stress; however, much less is known about the role that oxidative stress might have in the ageing of the endocrine system and the induction of age-related endocrine diseases. This Review outlines the interactions between hormones and oxidative metabolism and the potential effects of oxidative stress on ageing of endocrine organs. Many different mechanisms that link oxidative stress and ageing are discussed, all of which converge on the induction or regulation of inflammation. All these mechanisms, including cell senescence, mitochondrial dysfunction and microRNA dysregulation, as well as inflammation itself, could be targets of future studies aimed at clarifying the effects of oxidative stress on ageing of endocrine glands.

  7. Fipronil insecticide toxicology: oxidative stress and metabolism.

    PubMed

    Wang, Xu; Martínez, María Aránzazu; Wu, Qinghua; Ares, Irma; Martínez-Larrañaga, María Rosa; Anadón, Arturo; Yuan, Zonghui

    2016-11-01

    Fipronil (FIP) is widely used across the world as a broad-spectrum phenylpyrazole insecticide and veterinary drug. FIP was the insecticide to act by targeting the γ-aminobutyric acid (GABA) receptor and has favorable selective toxicity towards insects rather than mammals. However, because of accidental exposure, incorrect use of FIP or widespread FIP use leading to the contamination of water and soil, there is increasing evidence that FIP could cause a variety of toxic effects on animals and humans, such as neurotoxic, hepatotoxic, nephrotoxic, reproductive, and cytotoxic effects on vertebrate and invertebrates. In the last decade, oxidative stress has been suggested to be involved in the various toxicities induced by FIP. To date, few reviews have addressed the toxicity of FIP in relation to oxidative stress. The focus of this article is primarily intended to summarize the progress in research associated with oxidative stress as a possible mechanism for FIP-induced toxicity as well as metabolism. The present review reports that studies have been conducted to reveal the generation of reactive oxygen species (ROS) and oxidative stress as a result of FIP treatment and have correlated them with various types of toxicity. Furthermore, the metabolism of FIP was also reviewed, and during this process, various CYP450 enzymes were involved and oxidative stress might occur. The roles of various compounds in protecting against FIP-induced toxicity based on their anti-oxidative effects were also summarized to further understand the role of oxidative stress in FIP-induced toxicity.

  8. Quarterly Technical Progress Report

    SciTech Connect

    Yi Hua Ma

    1998-03-16

    The temperature dependence of the oxygen flux across the BaCe0G03 dense membrane (BCG membrane) tube was investigated. In the temperature range of 688C to 955C, the increase in the oxygen flux with temperature obeyed the Arrhenius law. An increase in the helium sweep flow membrane tube. rate in the tube side resulted in an increase in the oxygen flux through the The oxygen fluxes through the BCG dense membrane tube were measured at different oxygen partial pressures in the shell side. The oxygen flux increased with the oxygen partial pressure in the shell side. The BCG dense membrane was tested in a membrane reactor for the catalytic oxidative coupling of methane. The BCG membrane is not a complete combustion catalyst, and the catalytic activity of the BCG membrane was found to be much higher than the Argonne dense membrane. As the oxygen partial pressure in the shell side increased, the C2 decreased while the C2 yield remained unchanged, indicating that non-selective, reactions still played a significant role in the membrane reactor.

  9. Markers of Oxidative Stress during Diabetes Mellitus

    PubMed Central

    Tiwari, Brahm Kumar; Pandey, Kanti Bhooshan; Abidi, A. B.; Rizvi, Syed Ibrahim

    2013-01-01

    The prevalence of diabetes mellitus is rising all over the world. Uncontrolled state of hyperglycemia due to defects in insulin secretion/action leads to a variety of complications including peripheral vascular diseases, nephropathy, neuropathy, retinopathy, morbidity, and/or mortality. Large body of evidence suggests major role of reactive oxygen species/oxidative stress in development and progression of diabetic complications. In the present paper, we have discussed the recent researches on the biomarkers of oxidative stress during type 2 diabetes mellitus. PMID:26317014

  10. Oxidative stress in development: nature or nurture?

    PubMed

    Dennery, Phyllis A

    2010-10-15

    An unavoidable consequence of aerobic respiration is the generation of reactive oxygen species (ROS). These may negatively impact development. Nevertheless, a certain amount of oxidative stress is required to allow for the normal progression of embryonic and fetal growth. Alterations in placental oxidative stress results in altered placental function and ultimately altered fetal growth and/or developmental programming leading to long-term consequences into adulthood. This article reviews the role of redox in fetal development and will focus on how developmental programming is influenced by the fetal and placental redox state as well as discuss potential therapeutic interventions.

  11. Oxidation at Surfaces of Uranium Oxide Particles

    NASA Astrophysics Data System (ADS)

    Schueneman, Richard; Burgraff, Larry

    2001-04-01

    Uranium dioxide (UO2 (S)) is unstable in an oxidizing environment and oxidizes until covered with a layer of uranium trioxide (UO3 (C)). During the oxidation process, uranium cations change from U+4 to U+6 and the oxide crystal structure changes from face centered cubic to orthorhombic. Seven UO2(S) samples were prepared by pressing UO2 (S) powder into a tungsten screen and then subjected to five different temperatures and three partial pressures of oxygen. UO2 (S) oxidation was monitored with in situ photoluminescence (PL) spectroscopy. Quantitative oxidation data was obtained with secondary ion mass spectrometry (SIMS) and x-ray photoelectron spectroscopy (XPS). The in situ PL spectra did not identify UO3 (C) forming on the sample surfaces however, a new PL signature not associated with uranyl was observed. SIMS and XPS data from oxidized UO2 (S) samples indicated that at low temperatures, surface oxidation is kinetically limited and at high temperatures, surface oxidation is limited by diffusion. A model for the oxidation rate to UO3 (C) was not developed due to the temperature dependant oxidation process and high vacuum reduction of amorphous UO3 (A) present on the UO2 (S) sample surfaces prior to oxidation. A PL emission spectra intensity reduction was noticed on a UO3 (C) sample at room temperature under high vacuum. A reduction and re-oxidation of three additional UO3 (C) samples identified a kinetically irreversible reduction process for UO3(C) under high vacuum. A SIMS surface scan was performed on a fourth UO3(C) sample before and after exposure to ultra-high vacuum (10-8 torr) and the results suggest the reduction of UO3(C) to lower oxides (U3O8, U3O7 and UO2) at room temperature.

  12. Oxidation resistance of silicon ceramics

    NASA Technical Reports Server (NTRS)

    Yasutoshi, H.; Hirota, K.

    1984-01-01

    Oxidation resistance, and examples of oxidation of SiC, Si3N4 and sialon are reviewed. A description is given of the oxidation mechanism, including the oxidation product, oxidation reaction and the bubble size. The oxidation reactions are represented graphically. An assessment is made of the oxidation process, and an oxidation example of silicon ceramics is given.

  13. Chemiluminescence of nitric oxide

    NASA Technical Reports Server (NTRS)

    Sharp, W. E.; Rusch, D. W.

    1981-01-01

    Measurements of the intensities of the delta and gamma bands of nitric oxide in the nighttime terrestrial thermosphere are presented and used to infer the rate coefficient for the transition from the C 2 Pi to the A 2 Sigma + states. The nightglow spectrum was observed between 1900 and 2300 A at a resolution of 15 A by a rocket-borne scanning 1/4-m spectrometer pointing north at an apogee of 150 km. Progressions of the delta, gamma and epsilon bands are identified on the spectra by the construction of synthetic spectra, and the contributions of resonance fluorescence to the total band intensities are calculated. Finally, the ratio of the sum of the gamma bands for v-prime = 0 to the sum of the delta bands for v-prime = 0 is used to derive a branching ratio of 0.21 + or - 0.04 to the A 2 Sigma + state, which yields a probability for the C-A transition of 5.6 + or - 1.5 x to the 6th/sec.

  14. Integrated Proteomic and Metabolic Analysis of Breast Cancer Progression

    PubMed Central

    Shaw, Patrick G.; Chaerkady, Raghothama; Wang, Tao; Vasilatos, Shauna; Huang, Yi; Van Houten, Bennett; Pandey, Akhilesh; Davidson, Nancy E.

    2013-01-01

    One of the most persistent hallmarks of cancer biology is the preference of tumor cells to derive energy through glycolysis as opposed to the more efficient process of oxidative phosphorylation (OXPHOS). However, little is known about the molecular cascades by which oncogenic pathways bring about this metabolic switch. We carried out a quantitative proteomic and metabolic analysis of the MCF10A derived cell line model of breast cancer progression that includes parental cells and derivatives representing three different tumor grades of Ras-driven cancer with a common genetic background. A SILAC (Stable Isotope Labeling by Amino acids in Cell culture) labeling strategy was used to quantify protein expression in conjunction with subcellular fractionation to measure dynamic subcellular localization in the nucleus, cytosol and mitochondria. Protein expression and localization across cell lines were compared to cellular metabolic rates as a measure of oxidative phosphorylation (OXPHOS), glycolysis and cellular ATP. Investigation of the metabolic capacity of the four cell lines revealed that cellular OXPHOS decreased with breast cancer progression independently of mitochondrial copy number or electron transport chain protein expression. Furthermore, glycolytic lactate secretion did not increase in accordance with cancer progression and decreasing OXPHOS capacity. However, the relative expression and subcellular enrichment of enzymes critical to lactate and pyruvate metabolism supported the observed extracellular acidification profiles. This analysis of metabolic dysfunction in cancer progression integrated with global protein expression and subcellular localization is a novel and useful technique for determining organelle-specific roles of proteins in disease. PMID:24086712

  15. Thermally exfoliated graphite oxide

    NASA Technical Reports Server (NTRS)

    Prud'Homme, Robert K. (Inventor); Aksay, Ilhan A. (Inventor); Abdala, Ahmed (Inventor)

    2011-01-01

    A modified graphite oxide material contains a thermally exfoliated graphite oxide with a surface area of from about 300 sq m/g to 2600 sq m/g, wherein the thermally exfoliated graphite oxide displays no signature of the original graphite and/or graphite oxide, as determined by X-ray diffraction.

  16. Electrochemical oxidation of cholesterol

    PubMed Central

    2015-01-01

    Summary Indirect cholesterol electrochemical oxidation in the presence of various mediators leads to electrophilic addition to the double bond, oxidation at the allylic position, oxidation of the hydroxy group, or functionalization of the side chain. Recent studies have proven that direct electrochemical oxidation of cholesterol is also possible and affords different products depending on the reaction conditions. PMID:25977713

  17. The Thermochronologist's Progress

    NASA Astrophysics Data System (ADS)

    Zeitler, P. K.

    2011-12-01

    We owe our current understanding of thermochronology less to a series of revolutionary insights than to a somewhat uneven intellectual pilgrimage that over fifty years has progressed in fits and starts. Though hampered at times by overenthusiasm, oversimplification, and misunderstandings, on balance the field advanced thanks to a blend of curiosity-driven research, tool-building motivated by new ideas about Earth science, and improvements in technology. But now that we've exploited most radiogenic systems and the major minerals that host them, and now that our models can devour CPU time along with the best of them, are we done? Have we reached peak thermochron? The answer of course is no, and papers in this session will demonstrate what new technologies and techniques might have to offer in the coming years. However, I will argue that the discipline as a whole has matured to a point where if thermochronology is to remain a mainstream tool as opposed to a weekend sport, we need to get serious about several challenges. The most fundamental challenge is that current geodynamic models (and even more complex models we can envision coding) have outpaced our meagre stockpile of kinetic calibrations, our understanding of detailed isotope systematics, and our ability to generate data with sufficient throughput. These issues will not be addressed adequately through the business-as-usual approach that brought us to our current knowledge, and some community effort will probably be needed to coordinate the hard work that will be required. But any serious attempt to answer important questions with accurate thermal histories that have low and well-defined uncertainties will require that we actually know the kinetics for the specific samples we are analyzing, that we fully understand scatter in the data, that we work with the large sample numbers that are required for some problems like landscape evolution, and that inversion tools fully explore the important aspects of both the

  18. Progress in Helioseismic Holography

    NASA Astrophysics Data System (ADS)

    Braun, D. C.

    2001-05-01

    Local Helioseismology uses acoustic waves to probe small-scale structures in the solar interior down to a spatial resolution imposed by wave diffraction. Although its practitioners, including this author, may sometimes employ measurements of the acoustic wave field made over a local area of the Sun's surface to examine its shallow layers, local helioseismology generally has a much broader utility. For example, some applications of helioseismic holography (and other local diagnostics) require global acoustic modes, observed over large portions of the surface, to produce diffraction-limited images of the far side or deep interior of the Sun. In this review, I will summarize recent progress achieved in seismic holography in collaboration with C. Lindsey (SPRC). With P. Scherrer and the SOI-MDI team at Stanford, we have helped to realize a daily synoptic monitor of far-side activity using medium-resolution MDI images obtained within 24 hours of their acquisition by the SOHO spacecraft. In addition, we have laid out the basic theoretical groundwork for the application of computational seismic holography to the deep solar interior to image the tachocline and underlying radiative core of the Sun. Taking advantage of the substantial depth sensitivity of horizontal-flow diagnostics, we have recently adapted our holographic software to test the basic techniques on the shallow subphotospheres of active regions. The utility of both ground- and space-based instruments is usually enhanced by their combination and comparison. I will present the results of holographic analyses of simultaneous GONG+ prototype and SOI-MDI observations of a large flare-producing active region. The general similarity of the helioseismic images from both instruments is noteworthy. This demonstrates the feasibility of increasing the temporal and spatial coverage available to local analyses by combining SOHO data with that obtained from the GONG+ network. We gratefully acknowledge recent support from the

  19. Benchtop Energetics Progress

    NASA Astrophysics Data System (ADS)

    Fajardo, Mario

    2011-06-01

    We have constructed an apparatus for investigating the reactive chemical dynamics of mg-scale energetic materials samples. We seek to advance the understanding of the reaction kinetics of energetic materials, and of the chemical influences on energetic materials sensitivity. We employ direct laser irradiation, and indirect laser-driven shock, techniques to initiate thin-film explosive samples contained in a high-vacuum chamber. Expansion of the reacting flow into vacuum quenches the chemistry and preserves reaction intermediates for interrogation via time-of-flight mass spectrometry (TOFMS). By rastering the sample coupon through the fixed laser beam focus, we generate hundreds of repetitive energetic events in a few minutes. A detonation wave passing through an organic explosive, such as pentaerythritol tetranitrate (PETN, C5H4N4O12) , is remarkably efficient in converting the solid explosive into final thermodynamically-stable gaseous products (e . g . N2, CO2, H2O...). Termination of a detonation at an explosive-to-vacuum interface produces an expanding pulse of hyperthermal molecular species, with leading-edge velocities ~10 km/s. In contrast, deflagration (subsonic combustion) of PETN in vacuum produces mostly reaction intermediates, such as NO and NO2, with much slower molecular velocities; consistent with expansion-quenched thermal decomposition of PETN. We propose to exploit these differences in product chemical identities and molecular species velocities to provide a chemically-based diagnostic for distinguishing between detonation and deflagration events. In this talk we also report recent progress towards the quantitative detection of hyperthermal neutral species produced by direct laser ablation of aluminum metal and of organic energetic materials, as a step towards demonstrating the ability to discriminate slow reaction intermediates from fast thermodynamically-stable final products. Work done in collaboration with Emily Fossum, Christopher Molek, and

  20. Mitochondrial Redox Signaling and Tumor Progression

    PubMed Central

    Chen, Yuxin; Zhang, Haiqing; Zhou, Huanjiao Jenny; Ji, Weidong; Min, Wang

    2016-01-01

    Cancer cell can reprogram their energy production by switching mitochondrial oxidative phosphorylation to glycolysis. However, mitochondria play multiple roles in cancer cells, including redox regulation, reactive oxygen species (ROS) generation, and apoptotic signaling. Moreover, these mitochondrial roles are integrated via multiple interconnected metabolic and redox sensitive pathways. Interestingly, mitochondrial redox proteins biphasically regulate tumor progression depending on cellular ROS levels. Low level of ROS functions as signaling messengers promoting cancer cell proliferation and cancer invasion. However, anti-cancer drug-initiated stress signaling could induce excessive ROS, which is detrimental to cancer cells. Mitochondrial redox proteins could scavenger basal ROS and function as “tumor suppressors” or prevent excessive ROS to act as “tumor promoter”. Paradoxically, excessive ROS often also induce DNA mutations and/or promotes tumor metastasis at various stages of cancer progression. Targeting redox-sensitive pathways and transcriptional factors in the appropriate context offers great promise for cancer prevention and therapy. However, the therapeutics should be cancer-type and stage-dependent. PMID:27023612

  1. [Basic biochemical processes in glaucoma progression].

    PubMed

    von Thun und Hohenstein-Blaul, N; Kunst, S; Pfeiffer, N; Grus, F H

    2015-05-01

    The term glaucoma summarizes a group of eye diseases that are accompanied by impairments of the optic nerve and related visual field deficits. An early diagnosis of glaucoma is currently not possible due to a lack of diagnostic tests; therefore, in most cases the disease is diagnosed many years after onset, which prevents an early therapy. The known risk factors for the development and progression of glaucomatous optic neuropathy comprise elevated intraocular pressure and a broad range of pressure fluctuations as well as lipometabolic disorders, genetic factor and diabetes. The consequences include the induction of anti-inflammatory proteins, elevated levels of oxidative stress and the destruction of retinal ganglion cells. Changes in the autoantibody repertoire have also been observed in the course of the disease. Basic ophthalmological research therefore focuses on the investigation of basic biochemical processes in the course of the disease. A better understanding of physiological and biochemical events is sought in order to develop new and more sensitive diagnostic options and to allow more targeted therapeutic measures. The understanding of biochemical processes allows a better insight into glaucoma progression to be gained, which will lead to improvements in diagnosis and therapy.

  2. Mitochondrial Redox Signaling and Tumor Progression.

    PubMed

    Chen, Yuxin; Zhang, Haiqing; Zhou, Huanjiao Jenny; Ji, Weidong; Min, Wang

    2016-03-25

    Cancer cell can reprogram their energy production by switching mitochondrial oxidative phosphorylation to glycolysis. However, mitochondria play multiple roles in cancer cells, including redox regulation, reactive oxygen species (ROS) generation, and apoptotic signaling. Moreover, these mitochondrial roles are integrated via multiple interconnected metabolic and redox sensitive pathways. Interestingly, mitochondrial redox proteins biphasically regulate tumor progression depending on cellular ROS levels. Low level of ROS functions as signaling messengers promoting cancer cell proliferation and cancer invasion. However, anti-cancer drug-initiated stress signaling could induce excessive ROS, which is detrimental to cancer cells. Mitochondrial redox proteins could scavenger basal ROS and function as "tumor suppressors" or prevent excessive ROS to act as "tumor promoter". Paradoxically, excessive ROS often also induce DNA mutations and/or promotes tumor metastasis at various stages of cancer progression. Targeting redox-sensitive pathways and transcriptional factors in the appropriate context offers great promise for cancer prevention and therapy. However, the therapeutics should be cancer-type and stage-dependent.

  3. The Progress of Nations, 1999.

    ERIC Educational Resources Information Center

    United Nations Children's Fund, New York, NY.

    This report summarizes the latest available statistics on international progress on children's well-being. Each of the report's sections contains a commentary, related statistics, and a discussion on progress and disparity in the section's particular area. Following a foreword by United Nations Secretary-General Kofi A. Annan, the sections of the…

  4. The Progress of Nations, 2000.

    ERIC Educational Resources Information Center

    United Nations Children's Fund, New York, NY.

    This report summarizes the latest available statistics on international progress on children's well-being. Each section of the report contains a commentary, related statistics, and a discussion on progress and disparity in the section's particular area. Following a foreword by United Nations Secretary-General Kofi A. Annan, the sections of the…

  5. Progress in NASA Rotorcraft Propulsion

    NASA Technical Reports Server (NTRS)

    DellaCorte, Christopher; Johnson, Susan M.

    2008-01-01

    This presentation reviews recent progress made under NASA s Subsonic Rotary Wing (SRW) propulsion research activities. Advances in engines, drive systems and optimized propulsion systems are discussed. Progress in wide operability compressors, modeling of variable geometry turbine performance, foil gas bearings and multi-speed transmissions are presented.

  6. The Progress of Nations, 1999.

    ERIC Educational Resources Information Center

    United Nations Children's Fund, New York, NY.

    This report summarizes the latest available statistics on international progress on children's well-being. Each of the report's sections contains a commentary, related statistics, and a discussion on progress and disparity in the section's particular area. Following a foreword by United Nations Secretary-General Kofi A. Annan, the sections of the…

  7. Enquiry into Student Progress 1968.

    ERIC Educational Resources Information Center

    Her Majestys Stationery Office, London (England).

    This report is the result of a study made to establish the extent of success and failure in degree courses and the reasons for failure. The material is presented in a series of tables that approach the subject from the following points of view: (1) progress of undergraduate students in universities by subject group; (2) progress of undergraduate…

  8. The Progress of Nations, 2000.

    ERIC Educational Resources Information Center

    United Nations Children's Fund, New York, NY.

    This report summarizes the latest available statistics on international progress on children's well-being. Each section of the report contains a commentary, related statistics, and a discussion on progress and disparity in the section's particular area. Following a foreword by United Nations Secretary-General Kofi A. Annan, the sections of the…

  9. Understanding nuclei: progress and challenges

    SciTech Connect

    Dean, D. J.

    2008-04-17

    Nuclear theory today aims for a comprehensive theoretical framework that can describe all nuclei. I discuss recent progress in this pursuit and the associated challenges as we move forward, paying particular attention to progress in the applications of coupled-cluster theory to the challenges.

  10. Scientific progress: Knowledge versus understanding.

    PubMed

    Dellsén, Finnur

    2016-04-01

    What is scientific progress? On Alexander Bird's epistemic account of scientific progress, an episode in science is progressive precisely when there is more scientific knowledge at the end of the episode than at the beginning. Using Bird's epistemic account as a foil, this paper develops an alternative understanding-based account on which an episode in science is progressive precisely when scientists grasp how to correctly explain or predict more aspects of the world at the end of the episode than at the beginning. This account is shown to be superior to the epistemic account by examining cases in which knowledge and understanding come apart. In these cases, it is argued that scientific progress matches increases in scientific understanding rather than accumulations of knowledge. In addition, considerations having to do with minimalist idealizations, pragmatic virtues, and epistemic value all favor this understanding-based account over its epistemic counterpart.

  11. "A New Class of Creep Resistant Oxide/Oxide Ceramic Matrix Composites"

    SciTech Connect

    Dr. Mohit Jain, Dr. Ganesh Skandan, Prof. Roger Cannon, Rutgers University

    2007-03-30

    Despite recent progress in the development of SiC-SiC ceramic matrix composites (CMCs), their application in industrial gas turbines for distributed energy (DE) systems has been limited. The poor oxidation resistance of the non-oxide ceramics warrants the use of envrionmental barrier coatings (EBCs), which in turn lead to issues pertaining to life expectancy of the coatings. On the other hand, oxide/oxide CMCs are potential replacements, but their use has been limited until now due to the poor creep resistance at high temperatures, particularly above 1200 oC: the lack of a creep resistant matrix has been a major limiting factor. Using yttrium aluminum garnet (YAG) as the matrix material system, we have advanced the state-of-the-art in oxide/oxide CMCs by introducing innovations in both the structure and composition of the matrix material, thereby leading to high temperature matrix creep properties not achieved until now. An array of YAG-based powders with a unique set of particle characteristics were produced in-house and sintered to full density and compressive creep data was obtained. Aided in part by the composition and the microstructure, the creep rates were found to be two orders of magnitude smaller than the most creep resistant oxide fiber available commercially. Even after accounting for porosity and a smaller matrix grain size in a practical CMC component, the YAG-based matrix material was found to creep slower than the most creep resistant oxide fiber available commercially.

  12. Role of Oxidative Stress in Prostate Cancer

    PubMed Central

    Khandrika, Lakshmipathi; Kumar, Binod; Koul, Sweaty; Maroni, Paul; Koul, Hari K.

    2009-01-01

    As prostate cancer and aberrant changes in reactive oxygen species (ROS) become more common with aging, ROS signaling may play an important role in the development and progression of this malignancy. Increased ROS, otherwise known as oxidative stress, is a result of either increased ROS generation or a loss of antioxidant defense mechanisms. Oxidative stress is associated with several pathological conditions including inflammation and infection. ROS are products of normal cellular metabolism and play vital roles in stimulation of signaling pathways in response to changing intra- and extracellular environmental conditions. Chronic increases in ROS over time are known to induce somatic mutations and neoplastic transformation. In this review we summarize the causes for increased ROS generation and its potential role in etiology and progression of prostate cancer. PMID:19185987

  13. Status of Chronic Oxidation Studies of Graphite

    SciTech Connect

    Contescu, Cristian I.; Mee, Robert W.

    2016-05-01

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

  14. Photo-oxidation catalysts

    DOEpatents

    Pitts, J. Roland; Liu, Ping; Smith, R. Davis

    2009-07-14

    Photo-oxidation catalysts and methods for cleaning a metal-based catalyst are disclosed. An exemplary catalyst system implementing a photo-oxidation catalyst may comprise a metal-based catalyst, and a photo-oxidation catalyst for cleaning the metal-based catalyst in the presence of light. The exposure to light enables the photo-oxidation catalyst to substantially oxidize absorbed contaminants and reduce accumulation of the contaminants on the metal-based catalyst. Applications are also disclosed.

  15. Metal Atom Oxidation Laser

    DTIC Science & Technology

    1976-09-01

    mixtures of dusts of rare earth fluorides and oxides administered intratracheally and by inhalation. Some of the test animals (guinea pigs) died of...neodymium and cerium oxides were also made. These dusts were administered intratracheally to white rats. The investigation showed that these oxides...but milder. Cerium oxide was the least damaging of the three. With regard to the" aerosols of the oxides of yttrium, neodymium and other rare earth

  16. [Recent progress in mycobacteriology].

    PubMed

    Okada, Masaji; Kobayashi, Kazuo

    2007-10-01

    Mycobacterium tuberculosis is one of the most successful bacterial parasites of humans, infecting over one-third of the population of the world as latent infection without clinical manifestations. Over 8.8 million new cases and nearly 2 million deaths by tuberculosis (TB) occur annually. TB poses a significant health threat to the world population. The goal of this symposium is to open new avenues for combating tuberculosis. The speakers have presented their data and provided control strategies against tuberculosis and pulmonary disease due to M. avium complex (MAC) from aspects of molecular epidemiology, pathogenesis, serodiagnosis, new anti-TB drugs, and vaccine development. Drs. Maeda and Murase have reported that the 12-locus VNTR analysis is very useful for molecular epidemiology of M. tuberculosis strains isolated in Japan better than IS6110-RFLP and suggested that the analysis is powerful tool for the molecular epidemiology. Drs. Matsumoto and Kobayashi have discovered a protein, mycobacterial DNA-binding protein 1 (MDPl), overproduced in dormant M. tuberculosis that plays key roles in latent/ persistent infection, disease progression, and host protection. They have concluded that MDP1 may be a possible target for anti-tuberculosis drugs and vaccines. Drs. Kitada and Maekura have developed serodiagnosis of MAC disease based on enzyme immunoassay (EIA) by detecting anti-glycopeptidolipid (GPL) antibody in sera of human patients. GPL is specific for MAC. The EIA is a simple, rapid and accurate measure with high sensitivity and specificity. The levels of antibody also reflect disease activity. A large-scale clinical multicenter study is currently in progress. Dr. Makoto Matsumoto has discovered an innovative new anti-TB drug, OPC-67683 that is a derivative of nitroimidazole compounds. OPC-67683 inhibited mycolic acid synthesis and exerted potent antimycobacterial activity, including multidrug-resistant M. tuberculosis. Multidrug therapy using OPC-67683 could

  17. PATHWAYS OF MEDICAL PROGRESS.

    PubMed

    Wiggers, C J

    1940-01-12

    During the three decades that have passed, medical science has ascended to a high plateau of achievement. The climb has involved several pathways; among them: (1) the physiological approach toward disease as experiments which nature performs on organisms, (2) the more intelligent interpretation of the functional reactions of the body in disease in accordance with latest discoveries in physiology, (3) the supplementation of observable phenomena through use of laboratory instruments, (4) the assumption of active investigation both on patients and experimental animals by clinicians themselves, (5) the shuttling of problems between clinical and experimental laboratories and (6) correlated research in clinical and physiological departments. As we look down from the heights we have reached, we have reason to be pleased with our progress; but when we look ahead we become aware that there are still high mountain ranges to be climbed. We realize that their ascent can not be accomplished by employing merely the methods, equipment and strategy that have proved successful so far; we must improve the application of principles that are old and well established, and evolve others that are new. Above all, we from laboratories and clinics must join hands to help each other climb; and through correlated team-work overcome the great obstacles that jealous nature places in our way. I have ventured to suggest a few directions which such mutual help may take. They include (1) means by which new fundamental discoveries can be utilized more quickly by clinicians and practitioners of medicine; (2) plans by which younger clinical investigators can be given approximately the same opportunity for training in research technique as their colleagues entering experimental sciences; (3) pleas that the shuttling of problems between hospitals and laboratories of fundamental science may continue in order that the ultimate significance of clinical results may be better understood and that the

  18. Study of intermediates from transition metal excited-state electron- transfer reactions. Progress report, January 1, 1992--March 31, 1993

    SciTech Connect

    Hoffman, M.Z.

    1993-03-31

    Progress on 6 projects is reported: excited state absorption spectrum of Ru(bpy){sub 3}{sup 2+}, solvent cage model for electron transfer quenching, reductive quenching of {sup *}Cr(III) complexes, solution medium effects in oxidative quenching of {sup *}Ru(II) complexes, photosensitized oxidation of phenol in aqueous solution, and quenching of Ru(II) complexes by oxygen.

  19. Oxidative Degradation and Stabilisation of Mineral Oil-Based Lubricants

    NASA Astrophysics Data System (ADS)

    Aguilar, G.; Mazzamaro, G.; Rasberger, M.

    Thermally induced hydrocarbon oxidation is a self-accelerating autoxidation process and is divided into 'low'-, 30-120°C, and 'high'-, >120°C, temperature phases. The first has four stages - induction of radical chain reactions, propagation, branching and then termination. Mechanisms of these processes are described and discussed. Differences in hydrocarbon reactivity are related to molecular structure. For hydrocarbon oxidation >120°C, the first stage is the same as low-temperature oxidation but with reduced selectivity and increased reactivity; second, the oxidation phase becomes diffusion controlled as hydrocarbon viscosities increase from progressive polycondensation of higher molecular weight products, causing varnish and sludge formation. Base oil oxidation stabilities depend upon their derivation, whether solvent neutral, hydrocracked or synthetic, and their response to antioxidant treatment. Lubricant oxidation control focuses on radical scavengers and hydroperoxide decomposers and their synergistic mixtures.

  20. Oxidation of DNA bases, deoxyribonucleosides and homopolymers by peroxyl radicals.

    PubMed Central

    Simandan, T; Sun, J; Dix, T A

    1998-01-01

    DNA base oxidation is considered to be a key event associated with disease initiation and progression in humans. Peroxyl radicals (ROO. ) are important oxidants found in cells whose ability to react with the DNA bases has not been characterized extensively. In this paper, the products resulting from ROO. oxidation of the DNA bases are determined by gas chromatography/MS in comparison with authentic standards. ROO. radicals oxidize adenine and guanine to their 8-hydroxy derivatives, which are considered biomarkers of hydroxyl radical (HO.) oxidations in cells. ROO. radicals also oxidize adenine to its hydroxylamine, a previously unidentified product. ROO. radicals oxidize cytosine and thymine to the monohydroxy and dihydroxy derivatives that are formed by oxidative damage in cells. Identical ROO. oxidation profiles are observed for each base when exposed as deoxyribonucleosides, monohomopolymers and base-paired dihomopolymers. These results have significance for the development, utilization and interpretation of DNA base-derived biomarkers of oxidative damage associated with disease initiation and propagation, and support the idea that the mutagenic potential of N-oxidized bases, when generated in cellular DNA, will require careful evaluation. Adenine hydroxylamine is proposed as a specific molecular probe for the activity of ROO. in cellular systems. PMID:9761719

  1. NO2 oxidation reactivity and burning mode of diesel particulates

    DOE PAGES

    Strzelec, Andrea; Vander Wal, Randy L.; Thompson, Thomas N.; ...

    2016-03-24

    The NO2 oxidation kinetics and burning mode for diesel particulate from light-duty and medium-duty engines fueled with either ultra low sulfur diesel or soy methyl ester biodiesel blends have been investigated and are shown to be significantly different from oxidation by O2. Oxidation kinetics were measured using a flow-through packed bed microreactor for temperature programmed reactions and isothermal differential pulsed oxidation reactions. The burning mode was evaluated using the same reactor system for flowing BET specific surface area measurements and HR-TEM with fringe analysis to evaluate the nanostructure of the nascent and partially oxidized particulates. The low activation energy measured,more » specific surface area progression with extent of oxidation, HR-TEM images and difference plots of fringe length and tortuosity paint a consistent picture of higher reactivity for NO2, which reacts indiscriminately immediately upon contact with the surface, leading to the Zone I or shrinking core type oxidation. In comparison, O2 oxidation is shown to have relatively lower reactivity, preferentially attacking highly curved lamella, which are more reactive due to bond strain, and short lamella, which have a higher proportion of more reactive edge sites. Furthermore, this preferential oxidation leads to Zone II type oxidation, where solid phase diffusion of oxygen via pores contributes significantly to slowing the overall oxidation rate, by comparison.« less

  2. Allene oxide synthases and allene oxides.

    PubMed

    Tijet, Nathalie; Brash, Alan R

    2002-08-01

    Allene oxides are unstable epoxides formed by the enzymatic dehydration of the lipoxygenase products of polyunsaturated fatty acids. The allene oxide synthases are of two structurally-unrelated types. In plants, a subfamily of cytochromes P450, designated as CYP74A, use the hydroperoxides of linoleic and linolenic acids as substrate. Both the 9- and 13-hydroperoxides may be converted to allene oxides and subsequently give rise to plant signaling molecules. In corals, a catalase-related hemoprotein functions as the allene oxide synthase. These marine invertebrates, as well as starfish, form allene oxides from the 8R-hydroperoxide of arachidonic acid. The coral allene oxide synthase from Plexaura homomalla occurs as the N-terminal domain of a natural fusion protein with the 8R-lipoxygenase that forms its substrate. This enzyme may be involved in biosynthesis of the cyclopentenone eicosanoids such as the clavulones.

  3. The Enzymatic Oxidation of Graphene Oxide

    PubMed Central

    Kotchey, Gregg P.; Allen, Brett L.; Vedala, Harindra; Yanamala, Naveena; Kapralov, Alexander A.; Tyurina, Yulia Y.; Klein-Seetharaman, Judith; Kagan, Valerian E.; Star, Alexander

    2011-01-01

    Two-dimensional graphitic carbon is a new material with many emerging applications, and studying its chemical properties is an important goal. Here, we reported a new phenomenon – the enzymatic oxidation of a single layer of graphitic carbon by horseradish peroxidase (HRP). In the presence of low concentrations of hydrogen peroxide (~40 µM), HRP catalyzed the oxidation of graphene oxide, which resulted in the formation of holes on its basal plane. During the same period of analysis, HRP failed to oxidize chemically reduced graphene oxide (RGO). The enzymatic oxidation was characterized by Raman, UV-Vis, EPR and FT-IR spectroscopy, TEM, AFM, SDS-PAGE, and GC-MS. Computational docking studies indicated that HRP was preferentially bound to the basal plane rather than the edge for both graphene oxide and RGO. Due to the more dynamic nature of HRP on graphene oxide, the heme active site of HRP was in closer proximity to graphene oxide compared to RGO, thereby facilitating the oxidation of the basal plane of graphene oxide. We also studied the electronic properties of the reduced intermediate product, holey reduced graphene oxide (hRGO), using field-effect transistor (FET) measurements. While RGO exhibited a V-shaped transfer characteristic similar to a single layer of graphene that was attributed to its zero band gap, hRGO demonstrated a p-type semiconducting behavior with a positive shift in the Dirac points. This p-type behavior rendered hRGO, which can be conceptualized as interconnected graphene nanoribbons, as a potentially attractive material for FET sensors. PMID:21344859

  4. The enzymatic oxidation of graphene oxide.

    PubMed

    Kotchey, Gregg P; Allen, Brett L; Vedala, Harindra; Yanamala, Naveena; Kapralov, Alexander A; Tyurina, Yulia Y; Klein-Seetharaman, Judith; Kagan, Valerian E; Star, Alexander

    2011-03-22

    Two-dimensional graphitic carbon is a new material with many emerging applications, and studying its chemical properties is an important goal. Here, we reported a new phenomenon--the enzymatic oxidation of a single layer of graphitic carbon by horseradish peroxidase (HRP). In the presence of low concentrations of hydrogen peroxide (∼40 μM), HRP catalyzed the oxidation of graphene oxide, which resulted in the formation of holes on its basal plane. During the same period of analysis, HRP failed to oxidize chemically reduced graphene oxide (RGO). The enzymatic oxidation was characterized by Raman, ultraviolet-visible, electron paramagnetic resonance, Fourier transform infrared spectroscopy, transmission electron microscopy, atomic force microscopy, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and gas chromatography-mass spectrometry. Computational docking studies indicated that HRP was preferentially bound to the basal plane rather than the edge for both graphene oxide and RGO. Owing to the more dynamic nature of HRP on graphene oxide, the heme active site of HRP was in closer proximity to graphene oxide compared to RGO, thereby facilitating the oxidation of the basal plane of graphene oxide. We also studied the electronic properties of the reduced intermediate product, holey reduced graphene oxide (hRGO), using field-effect transistor (FET) measurements. While RGO exhibited a V-shaped transfer characteristic similar to a single layer of graphene that was attributed to its zero band gap, hRGO demonstrated a p-type semiconducting behavior with a positive shift in the Dirac points. This p-type behavior rendered hRGO, which can be conceptualized as interconnected graphene nanoribbons, as a potentially attractive material for FET sensors.

  5. Targeting ECM Disrupts Cancer Progression

    PubMed Central

    Venning, Freja A.; Wullkopf, Lena; Erler, Janine T.

    2015-01-01

    Metastatic complications are responsible for more than 90% of cancer-related deaths. The progression from an isolated tumor to disseminated metastatic disease is a multistep process, with each step involving intricate cross talk between the cancer cells and their non-cellular surroundings, the extracellular matrix (ECM). Many ECM proteins are significantly deregulated during the progression of cancer, causing both biochemical and biomechanical changes that together promote the metastatic cascade. In this review, the influence of several ECM proteins on these multiple steps of cancer spread is summarized. In addition, we highlight the promising (pre-)clinical data showing benefits of targeting these ECM macromolecules to prevent cancer progression. PMID:26539408

  6. Progress 28 supply vehicle approach

    NASA Image and Video Library

    2008-02-07

    ISS016-E-027761 (7 Feb. 2008) --- Backdropped by a colorful Earth, an unpiloted Progress supply vehicle approaches the International Space Station. Progress 28 resupply craft launched at 7:03 a.m. (CST) on Feb. 5, 2008 from the Baikonur Cosmodrome in Kazakhstan to deliver more than 2.5 tons of food, fuel, oxygen and other supplies to the Expedition 16 crewmembers onboard the station. Progress automatically docked to the Pirs Docking Compartment at 8:30 a.m. (CST) on Feb. 7.

  7. Progress 24 resupply approaches ISS

    NASA Image and Video Library

    2007-01-20

    ISS014-E-12434 (19 Jan. 2007) --- Backdropped by a blue and white Earth, an unpiloted Progress supply vehicle approaches the International Space Station. The Progress 24 resupply craft launched at 8:12 p.m. (CST) on Jan. 17, 2007 from the Baikonur Cosmodrome in Kazakhstan to deliver 2.5 tons of food, fuel, oxygen and other supplies to the Expedition 14 crewmembers onboard the station. Progress automatically docked to the Pirs Docking Compartment at 8:59 p.m. (CST) on Jan. 19 as the spacecraft and the station flew approximately 220 miles above a point near the South Atlantic off the southeast coast of Uruguay.

  8. Progress 28 supply vehicle approach

    NASA Image and Video Library

    2008-02-07

    ISS016-E-027742 (7 Feb. 2008) --- Backdropped by a blue and white Earth, an unpiloted Progress supply vehicle approaches the International Space Station. Progress 28 resupply craft launched at 7:03 a.m. (CST) on Feb. 5, 2008 from the Baikonur Cosmodrome in Kazakhstan to deliver more than 2.5 tons of food, fuel, oxygen and other supplies to the Expedition 16 crewmembers onboard the station. Progress automatically docked to the Pirs Docking Compartment at 8:30 a.m. (CST) on Feb. 7.

  9. Progress 24 resupply approaches ISS

    NASA Image and Video Library

    2007-01-20

    ISS014-E-12364 (19 Jan. 2007) --- Backdropped by a blue Earth, an unpiloted Progress supply vehicle approaches the International Space Station. The Progress 24 resupply craft launched at 8:12 p.m. (CST) on Jan. 17, 2007 from the Baikonur Cosmodrome in Kazakhstan to deliver 2.5 tons of food, fuel, oxygen and other supplies to the Expedition 14 crewmembers onboard the station. Progress automatically docked to the Pirs Docking Compartment at 8:59 p.m. (CST) on Jan. 19 as the spacecraft and the station flew approximately 220 miles above a point near the South Atlantic off the southeast coast of Uruguay.

  10. Progress 28 supply vehicle approach

    NASA Image and Video Library

    2008-02-07

    ISS016-E-027798 (7 Feb. 2008) --- Backdropped by a blue and white Earth, an unpiloted Progress supply vehicle (seen as a tiny object just left of center) approaches the International Space Station. Progress 28 resupply craft launched at 7:03 a.m. (CST) on Feb. 5, 2008 from the Baikonur Cosmodrome in Kazakhstan to deliver more than 2.5 tons of food, fuel, oxygen and other supplies to the Expedition 16 crewmembers onboard the station. Progress automatically docked to the Pirs Docking Compartment at 8:30 a.m. (CST) on Feb. 7.

  11. Progress 28 supply vehicle approach

    NASA Image and Video Library

    2008-02-07

    ISS016-E-027815 (7 Feb. 2008) --- Backdropped by a colorful Earth, an unpiloted Progress supply vehicle approaches the International Space Station. Progress 28 resupply craft launched at 7:03 a.m. (CST) on Feb. 5, 2008 from the Baikonur Cosmodrome in Kazakhstan to deliver more than 2.5 tons of food, fuel, oxygen and other supplies to the Expedition 16 crewmembers onboard the station. Progress automatically docked to the Pirs Docking Compartment at 8:30 a.m. (CST) on Feb. 7.

  12. Federal Facility Agreement progress report

    SciTech Connect

    Not Available

    1993-10-01

    The (SRS) Federal Facility Agreement (FFA) was made effective by the US. Environmental Protection Agency Region IV (EPA) on August 16, 1993. To meet the reporting requirements in Section XXV of the Agreement, the FFA Progress Report was developed. The FFA Progress Report is the first of a series of quarterly progress reports to be prepared by the SRS. As such this report describes the information and action taken to September 30, 1993 on the SRS units identified for investigation and remediation in the Agreement. This includes; rubble pits, runoff basins, retention basin, seepage basin, burning pits, H-Area Tank 16, and spill areas.

  13. Progress 12P approaching ISS

    NASA Image and Video Library

    2003-08-31

    ISS007-E-13814 (30 August 2003) --- Backdropped by a blue and white Earth, an unpiloted Progress supply vehicle approaches the International Space Station (ISS). The Progress 12 resupply craft, which launched from the Baikonur Cosmodrome in Kazakhstan at 8:48 p.m. (CDT) on August 28, 2003, carried nearly three tons of food, fuel, water, supplies and scientific gear for the Expedition 7 crew aboard the Station. The Progress linked up with the Station at 10:40 p.m. (CDT) on August 30, 2003 as the two spacecraft were flying over Central Asia at an altitude of 240 statute miles.

  14. Progress 12P approaching ISS

    NASA Image and Video Library

    2003-08-31

    ISS007-E-13808 (30 August 2003) --- Backdropped by Earth’s horizon, an unpiloted Progress supply vehicle approaches the International Space Station (ISS). The Progress 12 resupply craft, which launched from the Baikonur Cosmodrome in Kazakhstan at 8:48 p.m. (CDT) on August 28, 2003, carried nearly three tons of food, fuel, water, supplies and scientific gear for the Expedition 7 crew aboard the Station. The Progress linked up with the Station at 10:40 p.m. (CDT) on August 30, 2003 as the two spacecraft were flying over Central Asia at an altitude of 240 statute miles.

  15. Progress 12P approaching ISS

    NASA Image and Video Library

    2003-08-31

    ISS007-E-13811 (30 August 2003) --- Backdropped by a blue and white Earth, an unpiloted Progress supply vehicle approaches the International Space Station (ISS). The Progress 12 resupply craft, which launched from the Baikonur Cosmodrome in Kazakhstan at 8:48 p.m. (CDT) on August 28, 2003, carried nearly three tons of food, fuel, water, supplies and scientific gear for the Expedition 7 crew aboard the Station. The Progress linked up with the Station at 10:40 p.m. (CDT) on August 30, 2003 as the two spacecraft were flying over Central Asia at an altitude of 240 statute miles.

  16. Targeting ECM Disrupts Cancer Progression.

    PubMed

    Venning, Freja A; Wullkopf, Lena; Erler, Janine T

    2015-01-01

    Metastatic complications are responsible for more than 90% of cancer-related deaths. The progression from an isolated tumor to disseminated metastatic disease is a multistep process, with each step involving intricate cross talk between the cancer cells and their non-cellular surroundings, the extracellular matrix (ECM). Many ECM proteins are significantly deregulated during the progression of cancer, causing both biochemical and biomechanical changes that together promote the metastatic cascade. In this review, the influence of several ECM proteins on these multiple steps of cancer spread is summarized. In addition, we highlight the promising (pre-)clinical data showing benefits of targeting these ECM macromolecules to prevent cancer progression.

  17. [Domestic violence: any progress?].

    PubMed

    Henrion, Roger

    2014-01-01

    Since the publication of the French national survey of violence against women in 2000, the fight against domestic violence has made steady progress. Knowledge of the phenomenon has significantly improved. A nationwide study of murders and manslaughters perpetrated by one partner of a couple against the other has been published annually since 2006. In 2012, domestic violence resulted in the deaths of 314 persons: 166 women, 31 men, 25 children, 9 collateral victims, 14 rivals, and two former spouses killed by their ex-fathers in law. In addition, 67 perpetrators committed suicide (51 men and3 women). The number of victims fluctuates from year to year but has remained fairly stable since 2006 (n=168). Legislation has improved significantly: eight new laws have been passed since 2004, all designed to protect women and to ensure that violent men are restrained and treated. New measures to inform and protect women have been implemented and others have been improved, such as the anonymous helpline (phone no 3919, "domestic violence information"). An inter-ministerial committee on the protection of women from violence and the prevention of human trafficking (MIPROF) was created on 3 January 2013. A website entitled "Stop violence against women " (Stop violences faites aux femmes) is now available. The "Imminent Danger" mobile phone system, designed to alert police if a suspected or known perpetrator breaches restraint conditions, will be extended to the entire country from January 2014. Referees charged with coordinating comprehensive long-tern care of women victims have been deployed at the county level. Information centers on the rights of women and families (CIDFF) now form a local nationwide network. Routine interviews with a midwife during the fourth month of pregnancy, focusing on the woman's emotional, economic and social conditions, have been implemented in 21 % of maternity units and should gradually be generalized. The authorities who have enforced the law have

  18. The impact of oxidative stress on hair.

    PubMed

    Trüeb, R M

    2015-12-01

    Oxidative stress reflects an imbalance between the systemic manifestation of reactive oxygen species and a biological system's ability to detoxify the reactive intermediates or to repair the resulting damage. Reactive oxygen species or free radicals are highly reactive molecules that can directly damage lipids, proteins, and DNA. They are generated by a multitude of endogenous and environmental challenges, while the body possesses endogenous defense mechanisms. With age, production of free radicals increases, while the endogenous defense mechanisms decrease. This imbalance leads to progressive damage of cellular structures, presumably resulting in the aging phenotype. While the role of oxidative stress has been widely discussed in skin aging, little focus has been placed on its impact on hair condition. Moreover, most literature on age-related hair changes focuses on alopecia, but it is equally important that the hair fibers that emerge from the scalp exhibit significant age-related changes that have equal impact on the overall cosmetic properties of hair. Sources of oxidative stress with impact on the pre-emerging fiber include: oxidative metabolism, smoking, UVR, and inflammation from microbial, pollutant, or irritant origins. Sources of oxidative stress with impact on the post-emerging fiber include: UVR (enhanced by copper), chemical insults, and oxidized scalp lipids. The role of the dermatologist is recognition and treatment of pre- and post-emerging factors for lifetime scalp and hair health. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  19. Fatty acid oxidation and ketogenesis during development.

    PubMed

    Girard, J; Duée, P H; Ferré, P; Pégorier, J P; Escriva, F; Decaux, J F

    1985-01-01

    Fatty acids are the preferred oxidative substrates of the heart, skeletal muscles, kidney cortex and liver in adult mammals. They are supplied to these tissues either as nonesterified fatty acids (NEFA), or as triglycerides after hydrolysis by lipoprotein lipase. During fetal life, tissue capacity to oxidize NEFA is very low, even in species in which the placental transfer of NEFA and carnitine is high. At birth, the ability to oxidize NEFA from endogenous sources or from milk (a high-fat diet) develops rapidly in various tissues and remains very high throughout the suckling period. Ketogenesis appears in the liver by 6 to 12 hrs after birth, and the ketone bodies are used as oxidative fuels by various tissues during the suckling period. At the time of weaning, the transition from a high-fat to a high-carbohydrate diet is attended by a progressive decrease in the ketogenic capacity of the liver, whereas other tissues (skeletal muscle, heart, kidney) maintain a high capacity for NEFA oxidation. The nutritional and hormonal factors involved in changes in fatty acid oxidation during development are discussed.

  20. Oxidative stress, protein modification and Alzheimer disease.

    PubMed

    Tramutola, A; Lanzillotta, C; Perluigi, M; Butterfield, D Allan

    2016-06-15

    Alzheimer disease (AD) is a progressive neurodegenerative disease that affects the elderly population with complex etiology. Many hypotheses have been proposed to explain different causes of AD, but the exact mechanisms remain unclear. In this review, we focus attention on the oxidative-stress hypothesis of neurodegeneration and we discuss redox proteomics approaches to analyze post-mortem human brain from AD brain. Collectively, these studies have provided valuable insights into the molecular mechanisms involved both in the pathogenesis and progression of AD, demonstrating the impairment of numerous cellular processes such as energy production, cellular structure, signal transduction, synaptic function, mitochondrial function, cell cycle progression, and degradative systems. Each of these cellular functions normally contributes to maintain healthy neuronal homeostasis, so the deregulation of one or more of these functions could contribute to the pathology and clinical presentation of AD. In particular, we discuss the evidence demonstrating the oxidation/dysfunction of a number of enzymes specifically involved in energy metabolism that support the view that reduced glucose metabolism and loss of ATP are crucial events triggering neurodegeneration and progression of AD.