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Sample records for additional oxygenated functional

  1. Ruzsa's Constant on Additive Functions

    Institute of Scientific and Technical Information of China (English)

    Jin Hui FANG; Yong Gao CHEN

    2013-01-01

    A function f:N → R is called additive if f(mn) =f(m)+f(n) for all m,n with (m,n) =1.Let μ(x) =maxn≤x(f(n)-f(n + 1)) and v(x) =maxn≤x(f(n + 1)-f(n)).In 1979,Ruzsa proved that there exists a constant c such that for any additive function f,μ(x) ≤ cv(x2) + cf,where cf is a constant depending only on f.Denote by Raf the least such constant c.We call Raf Ruzsa's constant on additive functions.In this paper,we prove that Raf ≤ 20.

  2. Applying Additive Manufacturing to a New Liquid Oxygen Turbopump Design

    Science.gov (United States)

    O'Neal, Derek

    2016-01-01

    A liquid oxygen turbopump has been designed at Marshall Space Flight Center as part of the in-house, Advanced Manufacturing Demonstrator Engine (AMDE) project. Additive manufacturing, specifically direct metal laser sintering (DMLS) of Inconel 718, is used for 77% of the parts by mass. These parts include the impeller, turbine components, and housings. The near-net shape DMLS parts have been delivered and final machining is underway. Fabrication of the traditionally manufactured hardware is also proceeding. Testing in liquid oxygen is planned for Q2 of FY2017. This topic explores the design of the turbopump along with fabrication and material testing of the DMLS hardware.

  3. Applying Additive Manufacturing to a New Liquid Oxygen Turbopump Design

    Science.gov (United States)

    O’Neal, T. Derek

    2016-01-01

    A liquid oxygen turbopump has been designed at Marshall Space Flight Center as part of the in-house, Advanced Manufacturing Demonstrator Engine (AMDE) project. Additive manufacturing, specifically direct metal laser sintering (DMLS) of Inconel 718, is used for 77% of the parts by mass. These parts include the impeller, turbine components, and housings. This paper discusses the impacts of the DMLS fabrication technique on the design of the turbopump and lessons learned during DMLS hardware fabrication and material testing.

  4. Analysis of Mtbe as an Oxygenate Additive to Gasoline

    Directory of Open Access Journals (Sweden)

    C.AnishRaman

    2014-03-01

    Full Text Available One of the major drawbacks of IC engines is low efficiency and pollution resulting from incomplete combustion. In order to improve the emission properties and performance an oxygenated additive MTBE (Methyl tertiary butyl ether, is blended with gasoline. A four cylinder, 1817 cc engine was used for analysing both emission and performance characteristics. Tests were carried out with 100% pure gasoline and MTBE – blended gasoline (M5, M10. The BSFC and BTE of MTBE blended gasoline were observed to increase when compared to pure gasoline. Significant reduction in HC and CO emissions were observed with MTBE blended gasoline; however, CO2 and NOX emissions were increased. Keywords:

  5. Density functional theory study the effects of oxygen-containing functional groups on oxygen molecules and oxygen atoms adsorbed on carbonaceous materials.

    Science.gov (United States)

    Qi, Xuejun; Song, Wenwu; Shi, Jianwei

    2017-01-01

    Density functional theory was used to study the effects of different types of oxygen-containing functional groups on the adsorption of oxygen molecules and single active oxygen atoms on carbonaceous materials. During gasification or combustion reactions of carbonaceous materials, oxygen-containing functional groups such as hydroxyl(-OH), carbonyl(-CO), quinone(-O), and carboxyl(-COOH) are often present on the edge of graphite and can affect graphite's chemical properties. When oxygen-containing functional groups appear on a graphite surface, the oxygen molecules are strongly adsorbed onto the surface to form a four-member ring structure. At the same time, the O-O bond is greatly weakened and easily broken. The adsorption energy value indicates that the adsorption of oxygen molecules changes from physisorption to chemisorption for oxygen-containing functional groups on the edge of a graphite surface. In addition, our results indicate that the adsorption energy depends on the type of oxygen-containing functional group. When a single active oxygen atom is adsorbed on the bridge site of graphite, it gives rise to a stable epoxy structure. Epoxy can cause deformation of the graphite lattice due to the transition of graphite from sp2 to sp3 after the addition of an oxygen atom. For quinone group on the edge of graphite, oxygen atoms react with carbon atoms to form the precursor of CO2. Similarly, the single active oxygen atoms of carbonyl groups can interact with edge carbon atoms to form the precursor of CO2. The results show that oxygen-containing functional groups on graphite surfaces enhance the activity of graphite, which promotes adsorption on the graphite surface.

  6. Formation of functional groups on graphite during oxygen plasma treatment

    Energy Technology Data Exchange (ETDEWEB)

    Cvelbar, Uros [Plasma Laboratory, Jozef Stefan Institute, Jamova 39, Ljubljana SI-1000 (Slovenia)]. E-mail: uros.cvelbar@guest.arnes.si; Markoli, Bostjan [Faculty of Natural Sciences and Engineering, University of Ljubljana, Askerceva 12, Ljubljana SI-1000 (Slovenia); Poberaj, Igor [Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, Ljubljana SI-1000 (Slovenia); Zalar, Anton [Plasma Laboratory, Jozef Stefan Institute, Jamova 39, Ljubljana SI-1000 (Slovenia); Kosec, Ladislav [Faculty of Natural Sciences and Engineering, University of Ljubljana, Askerceva 12, Ljubljana SI-1000 (Slovenia); Spaic, Savo [Faculty of Natural Sciences and Engineering, University of Ljubljana, Askerceva 12, Ljubljana SI-1000 (Slovenia)

    2006-12-15

    Improved sample wettability was obtained by oxygen plasma functionalization of pyrolytic graphite. The samples were exposed to highly dissociated oxygen plasma with the density of 1 x 10{sup 16} m{sup -3}, the electron temperature of about 5.5 eV and the density of neutral oxygen atoms of 8 x 10{sup 21} m{sup -3} for 20 s. The surface wettability was measured by a contact angle of water drop. The contact angle dropped from original 112{sup o} down to about 1{sup o}. The functional groups were detected by XPS analyses. The survey spectrum showed a substantial increase of oxygen concentration on the surface, while high-resolution analyses showed additional oxygen was bonded onto the graphite surface in the form of C-O polar functional group responsible for the increase of the surface energy.

  7. Oxygen radical functionalization of boron nitride nanosheets

    OpenAIRE

    MAY, PETER; Coleman, Jonathan; MCGOVERN, IGNATIUS; GOUNKO, IOURI; Satti, Amro

    2012-01-01

    PUBLISHED The covalent chemical functionalization of exfoliated hexagonal boron-nitride nanosheets (BNNSs) is achieved by the solution phase oxygen radical functionalization of boron atoms in the h-BN lattice. This involves a two-step procedure to initially covalently graft alkoxy groups to boron atoms and the subsequent hydrolytic defunctionalisation of the groups to yield hydroxyl-functionalized BNNSs (OH-BNNSs). Characterization of the functionalized-BNNSs using HR-TEM, Raman, UV-Vis, F...

  8. ADDITIVE FUNCTIONALS AND PERTURBATION OF SEMIGROUP

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The perturbation of semigroup by a multiplicative functional with bounded variation is investigated in the frame of weak duality. The strong continuity and Schrodinger type equation of the perturbated semigroup are discussed. A few switching identities and formulae conerning dual additive functionals and Revuz measures are given.

  9. Oxygen radical functionalization of boron nitride nanosheets.

    Science.gov (United States)

    Sainsbury, Toby; Satti, Amro; May, Peter; Wang, Zhiming; McGovern, Ignatius; Gun'ko, Yurii K; Coleman, Jonathan

    2012-11-14

    The covalent chemical functionalization of exfoliated hexagonal boron-nitride nanosheets (BNNSs) is achieved by the solution-phase oxygen radical functionalization of boron atoms in the h-BN lattice. This involves a two-step procedure to initially covalently graft alkoxy groups to boron atoms and the subsequent hydrolytic defunctionalization of the groups to yield hydroxyl-functionalized BNNSs (OH-BNNSs). Characterization of the functionalized-BNNSs using HR-TEM, Raman, UV-vis, FTIR, NMR, and TGA was performed to investigate both the structure of the BNNSs and the covalent functionalization methodology. OH-BNNSs were used to prepare polymer nanocomposites and their mechanical properties analyzed. The influence of the functional groups grafted to the surface of the BNNSs is investigated by demonstrating the impact on mechanical properties of both noncovalent and covalent bonding at the interface between the nanofiller and polymer matrixes.

  10. ADDITIVE FUNCTIONALS AND PERTURBATION OF SEMIGROUP

    Institute of Scientific and Technical Information of China (English)

    JINMENGWEI; YINGJIANGANG

    2001-01-01

    The perturbation of semigroup by a multiplicative functional with bounded variation is investigated in the frame of weak duality. The strong continuity and SchrSdinger type equation of the perturbated semigroup are discussed. A few switching identities and formulae conerning dual additive functionais and Revuz measures are given.

  11. DEVELOPMENT OF A FUNCTIONAL FEED ADDITIVE

    Directory of Open Access Journals (Sweden)

    Lysenko Y. A.

    2016-01-01

    Full Text Available The new feed additives for animals based on milk whey, enriched with sprouting wheat, barley, maize grains and lactic-acid bacterium have been presented in this article. This study explores the possibility of combining the prebiotics ability of milk whey and sprouting grains with feed probiotic attributes of microbe to enhance gut health of animals and digestibility of the feed. Twelve variants of products were tested in the study using the microbial and physical-chemical approaches. All the assays showed high count of microorganism and high content of reducing sugar. The results of investigation indicate that selected feed additive show high quality. An additional point is that it contains useful organic acids (lactic, acetic and propionic acids and 2,1×109 colony-forming unit of probiotics microorganism that hold the concentration for 4 months. There are not yeast, must, coliform bacteria and Staphylococcus aureus in the developed functional feed product. It contributes to the normalization of the microflora of the gastrointestinal tract of animal, suppression of conditionally pathogenic and putrefactive microflora. The elaborated feed component will help to provide combined feed companies with accessible high-quality raw material

  12. Stimulation of aerobic degradation of bentazone, mecoprop and dichlorprop by oxygen addition to aquifer sediment

    Energy Technology Data Exchange (ETDEWEB)

    Levi, S.; Hybel, A.-M.; Bjerg, P.L.; Albrechtsen, H.-J., E-mail: hana@env.dtu.dk

    2014-03-01

    In order to investigate aerobic degradation potential for the herbicides bentazone, mecoprop and dichlorprop, anaerobic groundwater samples from two monitoring and three drinking water wells near a drinking water abstraction field in Nybølle, Denmark, were screened for their degradation potential for the herbicides. In the presence of oxygen {sup 14}C-labelled bentazone and mecoprop were removed significantly from the two monitoring wells' groundwater samples. Oxygen was added to microcosms in order to investigate whether different oxygen concentrations stimulate the biodegradation of the three herbicides in microcosms using groundwater and sandy aquifer materials. To maintain a certain oxygen concentration this level was measured from the outside of the bottles with a fibre oxygen meter using oxygen-sensitive luminescent sensor foil mounted inside the microcosm, to which supplementary oxygen was added. The highest oxygen concentrations (corresponding to 4–11 mg L{sup −1}) stimulated degradation (a 14–27% increase for mecoprop, 3–9% for dichlorprop and 15–20% for bentazone) over an experimental period of 200 days. Oxygen was required to biodegrade the herbicides, since no degradation was observed under anaerobic conditions. This is the first time bentazone degradation has been observed in aquifer material at low oxygen concentrations (2 mg L{sup −1}). The sediment had substantial oxygen consumption (0.92–1.45 O{sub 2} g{sup -1} dw over 200 days) and oxygen was depleted rapidly in most incubations soon after its addition, which might be due to the oxidation of organic matter and other reduced species such as Fe{sup 2+}, S{sup 2−} and Mn in sediment before the biodegradation of herbicides takes place. This study suggests that oxygen enhancement around a drinking water abstraction field could stimulate the bioremediation of diffuse source contamination. - Highlights: • Addition of different oxygen concentrations stimulated degradation of

  13. Oxygen switch in visible-light photoredox catalysis: radical additions and cyclizations and unexpected C-C-bond cleavage reactions.

    Science.gov (United States)

    Zhu, Shaoqun; Das, Arindam; Bui, Lan; Zhou, Hanjun; Curran, Dennis P; Rueping, Magnus

    2013-02-06

    Visible light photoredox catalyzed inter- and intramolecular C-H functionalization reactions of tertiary amines have been developed. Oxygen was found to act as chemical switch to trigger two different reaction pathways and to obtain two different types of products from the same starting material. In the absence of oxygen, the intermolecular addition of N,N-dimethyl-anilines to electron-deficient alkenes provided γ-amino nitriles in good to high yields. In the presence of oxygen, a radical addition/cyclization reaction occurred which resulted in the formation of tetrahydroquinoline derivatives in good yields under mild reaction conditions. The intramolecular version of the radical addition led to the unexpected formation of indole-3-carboxaldehyde derivatives. Mechanistic investigations of this reaction cascade uncovered a new photoredox catalyzed C-C bond cleavage reaction.

  14. Evaluation of Additively Manufactured Metals for Use in Oxygen Systems Project

    Science.gov (United States)

    Tylka, Jonathan; Cooper, Ken; Peralta, Stephen; Wilcutt, Terrence; Hughitt, Brian; Generazio, Edward

    2016-01-01

    Space Launch System, Commercial Resupply, and Commercial Crew programs have published intent to use additively manufactured (AM) components in propulsion systems and are likely to include various life support systems in the future. Parts produced by these types of additive manufacturing techniques have not been fully evaluated for use in oxygen systems and the inherent risks have not been fully identified. Some areas of primary concern in the SLS process with respect to oxygen compatibility may be the porosity of the printed parts, fundamental differences in microstructure of an AM part as compared to traditional materials, or increased risk of shed metal particulate into an oxygen system. If an ignition were to occur the printed material could be more flammable than components manufactured from a traditional billet of raw material and/or present a significant hazards if not identified and rigorously studied in advance of implementation into an oxygen system.

  15. Numerical Study of Heterogeneous Reactions in an SOFC Anode with Oxygen Addition

    OpenAIRE

    Hao, Yong; Goodwin, David G.

    2008-01-01

    Previous experimental studies have shown that addition of small amounts of oxygen to a hydrocarbon fuel stream can control coking in the anode, while relatively large amounts of oxygen are present in the fuel stream in single-chamber solid oxide fuel cells (SOFCs). In order to rationally design an anode for such use, it is important to understand the coupled catalytic oxidation/reforming chemistry and diffusion within the anode under SOFC operating conditions. In this study, the heterogeneous...

  16. Additive Functional Inequalities in Banach Modules

    Directory of Open Access Journals (Sweden)

    An JongSu

    2008-01-01

    Full Text Available Abstract We investigate the following functional inequality in Banach modules over a -algebra and prove the generalized Hyers-Ulam stability of linear mappings in Banach modules over a -algebra in the spirit of the Th. M. Rassias stability approach. Moreover, these results are applied to investigate homomorphisms in complex Banach algebras and prove the generalized Hyers-Ulam stability of homomorphisms in complex Banach algebras.

  17. Additive Manufacturing: From Form to Function

    Science.gov (United States)

    2016-01-01

    DOA)—worth a cu- mulative total of $608 million. The 2016 DOD-funded institute is the Revolutionary Fibers and Textiles Manufacturing Innovation ...Network for Manufacturing Innovation (NNMI). However, for AM to be considered a “game changing technology,” in- creases in functionality of the...was developed by the Innovative Advanced Concepts program. The sensor is essentially a transparent sheet of plastic with printed elec- tronics that

  18. Additive functionals and excursions of Kuznetsov processes

    Directory of Open Access Journals (Sweden)

    Hacène Boutabia

    2005-01-01

    semigroup of transition. In this paper, we give the excursion laws of (Xtt∈ℝ+ conditioned on the strict past and future without duality hypothesis. We study excursions of a general regenerative system and of a regenerative system consisting of the closure of the set of times the regular points of B are visited. In both cases, those conditioned excursion laws depend only on two points Xg− and Xd, where ]g,d[ is an excursion interval of the regenerative set M. We use the (FDt-predictable exit system to bring together the isolated points of M and its perfect part and replace the classical optional exit system. This has been a subject in literature before (e.g., Kaspi (1988 under the classical duality hypothesis. We define an “additive functional” for (Ytt∈ℝ with B, we generalize the laws cited before to (Ytt∈ℝ, and we express laws of pairs of excursions.

  19. Oxygen minimum seafloor ecological (mal) functioning

    NARCIS (Netherlands)

    Moodley, L.; Nigam, R.; Ingole, B.; Prakash Babu, C.; Panchang, R.; Nanajkar, M.; Sivadas, S.; van Breugel, P.; van IJzerloo, L.; Rutgers, R.; Heip, C.H.R.; Soetaert, K.; Middelburg, J.J.

    2011-01-01

    Although organic matter (OM) settling on the seafloor is generally rapidly recycled, a key ecological process, large scale burial events manifest itself in the marine sedimentary record as organic carbon (Corg)-rich layers. Presently, this prevails under certain oceanic settings such as the oxygen m

  20. Oxygen minimum seafloor ecological (mal) functioning

    NARCIS (Netherlands)

    Moodley, L.; Nigam, R.; Ingole, B.; Babu, C.P.; Panchang, R.; Nanajkar, M.; Sivadas, S.; van Breugel, P.; van Ijzerloo, L.; Rutgers, R.; Heip, C.H.R.; Middelburg, J.J.

    2011-01-01

    Although organic matter (OM) settling on the seafloor is generally rapidly recycled, a key ecological process, large scale burial events manifest itself in the marine sedimentary record as organic carbon (C(org))-rich layers. Presently, this prevails under certain oceanic settings such as the oxygen

  1. Effects of hypolimnetic oxygen addition on mercury bioaccumulation in Twin Lakes, Washington, USA.

    Science.gov (United States)

    Beutel, Marc; Dent, Stephen; Reed, Brandon; Marshall, Piper; Gebremariam, Seyoum; Moore, Barry; Cross, Benjamin; Gantzer, Paul; Shallenberger, Ed

    2014-10-15

    Twin Lakes, located on the Confederated Tribes of the Colville Indian Reservation in eastern Washington, USA, include North Twin Lake (NT) and South Twin Lake (ST). The mesotrophic, dimictic lakes are important recreational fishing sites for both warm-water bass and cold-water trout. To improve summertime cold-water habitat for trout in NT, dissolved oxygen (DO) addition to the hypolimnion, using liquid oxygen as an oxygen gas source, started in 2009. This study assessed mercury (Hg) in the water column, zooplankton and fish, and related water quality parameters, in Twin Lakes from 2009 to 2012. Because methylmercury (MeHg) buildup in lake bottom water is commonly associated with hypolimnetic anoxia, hypolimnetic oxygenation was hypothesized to reduce Hg in bottom waters and biota in NT relative to ST. Oxygen addition led to significantly higher DO (mean hypolimnetic DO: 2-8 mg/L versus mean hypolimnetic MeHg: 0.05-0.2 ng/L versus 0.15-0.4 ng/L) in North Twin. In North Twin, years with higher DO (2009 and 2011) exhibited lower MeHg in bottom waters and lower total Hg in zooplankton, inferring a positive linkage between oxygen addition and lower bioaccumulation. However, when comparing between the two lakes, Hg levels were significantly higher in zooplankton (total Hg range: 100-200 versus 50-100 μg/kg dry weight) and trout (spring 2010 stocking cohort of eastern brook trout mean total Hg: 74.9 versus 49.9 μg/kg wet weight) in NT relative to ST. Lower Hg bioaccumulation in ST compared to NT may be related to bloom dilution in chlorophyll-rich bottom waters, a vertical disconnect between the location of zooplankton and MeHg in the water column, and high binding affinity between sulfide and MeHg in bottom waters.

  2. Hyperbaric oxygen therapy improves cognitive functioning after brain injury

    Institute of Scientific and Technical Information of China (English)

    Su Liu; Guangyu Shen; Shukun Deng; Xiubin Wang; Qinfeng Wu; Aisong Guo

    2013-01-01

    Hyperbaric oxygen therapy has been widely applied and recognized in the treatment of brain injury;however, the correlation between the protective effect of hyperbaric oxygen therapy and changes of metabolites in the brain remains unclear. To investigate the effect and potential mechanism of hyperbaric oxygen therapy on cognitive functioning in rats, we established traumatic brain injury models using Feeney’s free fal ing method. We treated rat models with hyperbaric oxygen therapy at 0.2 MPa for 60 minutes per day. The Morris water maze test for spatial navigation showed that the average escape latency was significantly prolonged and cognitive function decreased in rats with brain injury. After treatment with hyperbaric oxygen therapy for 1 and 2 weeks, the rats’ spatial learning and memory abilities were improved. Hydrogen proton magnetic resonance spectroscopy analysis showed that the N-acetylaspartate/creatine ratio in the hippocampal CA3 region was sig-nificantly increased at 1 week, and the N-acetylaspartate/choline ratio was significantly increased at 2 weeks after hyperbaric oxygen therapy. Nissl staining and immunohistochemical staining showed that the number of nerve cells and Nissl bodies in the hippocampal CA3 region was significantly increased, and glial fibril ary acidic protein positive cells were decreased after a 2-week hyperbaric oxygen therapy treatment. Our findings indicate that hyperbaric oxygen therapy significantly im-proves cognitive functioning in rats with traumatic brain injury, and the potential mechanism is me-diated by metabolic changes and nerve cellrestoration in the hippocampal CA3 region.

  3. Hyperbaric oxygen therapy improves cognitive functioning after brain injury.

    Science.gov (United States)

    Liu, Su; Shen, Guangyu; Deng, Shukun; Wang, Xiubin; Wu, Qinfeng; Guo, Aisong

    2013-12-15

    Hyperbaric oxygen therapy has been widely applied and recognized in the treatment of brain injury; however, the correlation between the protective effect of hyperbaric oxygen therapy and changes of metabolites in the brain remains unclear. To investigate the effect and potential mechanism of hyperbaric oxygen therapy on cognitive functioning in rats, we established traumatic brain injury models using Feeney's free falling method. We treated rat models with hyperbaric oxygen therapy at 0.2 MPa for 60 minutes per day. The Morris water maze test for spatial navigation showed that the average escape latency was significantly prolonged and cognitive function decreased in rats with brain injury. After treatment with hyperbaric oxygen therapy for 1 and 2 weeks, the rats' spatial learning and memory abilities were improved. Hydrogen proton magnetic resonance spectroscopy analysis showed that the N-acetylaspartate/creatine ratio in the hippocampal CA3 region was significantly increased at 1 week, and the N-acetylaspartate/choline ratio was significantly increased at 2 weeks after hyperbaric oxygen therapy. Nissl staining and immunohistochemical staining showed that the number of nerve cells and Nissl bodies in the hippocampal CA3 region was significantly increased, and glial fibrillary acidic protein positive cells were decreased after a 2-week hyperbaric oxygen therapy treatment. Our findings indicate that hyperbaric oxygen therapy significantly improves cognitive functioning in rats with traumatic brain injury, and the potential mechanism is mediated by metabolic changes and nerve cell restoration in the hippocampal CA3 region.

  4. Numerical Study of Heterogeneous Reactions in an SOFC Anode With Oxygen Addition

    OpenAIRE

    Hao, Yong; Goodwin, David G.

    2007-01-01

    Previous experimental studies have shown that addition of smallamounts of oxygen to a hydrocarbon fuel stream can controlcoking in the anode, while relatively large amounts of oxygenare present in the fuel stream in single-chamber SOFCs. Inorder to rationally design an anode for such use, it isimportant to understand the coupled catalytic oxidation /reforming chemistry and diffusion within the anode under SOFCoperating conditions. In this study, the heterogeneous catalyticreactions in the ano...

  5. Polymer Growth Rate in a Wire Chamber with Oxygen,Water, or Alcohol Gas Additives

    Energy Technology Data Exchange (ETDEWEB)

    Boyarski, Adam; /SLAC

    2008-07-02

    The rate of polymer growth on wires was measured in a wire chamber while the chamber was aged initially with helium-isobutane (80:20) gas, and then with either oxygen, water, or alcohol added to the gas. At the completion of the aging process for each gas mixture, the carbon content on the wires was measured in a SEM/EDX instrument. The same physical wires were used in all the gas mixtures, allowing measurement of polymer build up or polymer depletion by each gas additive. It is found that the rate of polymer growth is not changed by the presence of oxygen, water or alcohol. Conjecture that oxygen reduces breakdown by removing polymer deposits on field wires is negated by these measurements. Instead, it appears that the reduced breakdown is due to lower resistance in the polymer from oxygen ions being transported into the polymer. It is also observed that field wires bombarded by the electrons in the SEM and then placed back into the chamber show an abundance of single electrons being emitted, indicating that electron charge is stored in the polymer layer and that a high electric field is necessary to remove the charge.

  6. Persistent Postconcussive Symptoms Are Accompanied by Decreased Functional Brain Oxygenation.

    Science.gov (United States)

    Helmich, Ingo; Saluja, Rajeet S; Lausberg, Hedda; Kempe, Mathias; Furley, Philip; Berger, Alisa; Chen, Jen-Kai; Ptito, Alain

    2015-01-01

    Diagnostic methods are considered a major concern in the determination of mild traumatic brain injury. The authors examined brain oxygenation patterns in subjects with severe and minor persistent postconcussive difficulties and a healthy control group during working memory tasks in prefrontal brain regions using functional near-infrared spectroscopy. The results demonstrated decreased working memory performances among concussed subjects with severe postconcussive symptoms that were accompanied by decreased brain oxygenation patterns. An association appears to exist between decreased brain oxygenation, poor performance of working memory tasks, and increased symptom severity scores in subjects suffering from persistent postconcussive symptoms.

  7. Oxygen additive amount dependence of rate of photoresist removal by H radicals generated on a tungsten hot-wire catalyst

    Science.gov (United States)

    Yamamoto, Masashi; Umemoto, Hironobu; Ohdaira, Keisuke; Shikama, Tomokazu; Nishiyama, Takashi; Horibe, Hideo

    2016-07-01

    We examined an environmentally friendly photoresist removal method using radicals produced by decomposing mixtures of hydrogen and oxygen on a hot tungsten catalyst. The photoresist removal rate increased with the oxygen additive amount (the flow rate ratio of oxygen to hydrogen) up to an optimal amount and then decreased gradually. When the catalyst temperature was 1600 °C, the optimal oxygen additive amount was 1.0% and the removal rate was 1.7 times higher than that in the pure hydrogen system. At 2000 °C, the optimal amount increased to 2.5% but the increase ratio decreased by 1.3 times. At high catalyst temperatures, the absolute removal rate as well as the optimal oxygen additive amount is high, but the increase ratio is low. At the optimal oxygen additive amount, H, O, and OH radicals may exert their effects together to decompose photosensitive polymers.

  8. Density functional for ternary non-additive hard sphere mixtures.

    Science.gov (United States)

    Schmidt, Matthias

    2011-10-19

    Based on fundamental measure theory, a Helmholtz free energy density functional for three-component mixtures of hard spheres with general, non-additive interaction distances is constructed. The functional constitutes a generalization of the previously given theory for binary non-additive mixtures. The diagrammatic structure of the spatial integrals in both functionals is of star-like (or tree-like) topology. The ternary diagrams possess a higher degree of complexity than the binary diagrams. Results for partial pair correlation functions, obtained via the Ornstein-Zernike route from the second functional derivatives of the excess free energy functional, agree well with Monte Carlo simulation data. © 2011 IOP Publishing Ltd

  9. Oxygen adsorption on pyrite (100) surface by density functional theory

    Institute of Scientific and Technical Information of China (English)

    孙伟; 胡岳华; 邱冠周; 覃文庆

    2004-01-01

    Pyrite (FeS2) bulk and (100) surface properties and the oxygen adsorption on the surface were studied by using density functional theory methods. The results show that in the formation of FeS2 (100) surface, there exists a process of electron transfer from Fe dangling bond to S dangling bond. In this situation, surface Fe and S atoms have more ionic properties. Both Fe2+ and S2- have high electrochemistry reduction activity, which is the base for oxygen adsorption. From the viewpoint of adsorption energy, the parallel form oxygen adsorption is in preference.The result also shows that the state of oxygen absorbed on FeS2 surface acts as peroxides rather than O2.

  10. Addition formulae for Abelian functions associated with specialized curves.

    Science.gov (United States)

    Eilbeck, J C; Matsutani, S; Onishi, Y

    2011-03-28

    We discuss a family of multi-term addition formulae for Weierstrass functions on specialized curves of low genus with many automorphisms, concentrating mostly on the case of genus 1 and 2. In the genus 1 case, we give addition formulae for the equianharmonic and lemniscate cases, and in genus 2 we find some new addition formulae for a number of curves.

  11. Effects of Dissolved Oxygen Concentration and Iron Addition on Immediate-early Gene Expression of Magnetospirillum gryphiswaldense MSR-1

    DEFF Research Database (Denmark)

    Zhuang, Shiwen; Anyaogu, Diana Chinyere; Kasama, Takeshi

    2017-01-01

    iron addition for all the genes studied, except for MgFnr (oxygen sensor gene) and fur (ferric uptake regulator family gene), and which in some cases was oxygen-dependent. In particular, expression of sodB1 (superoxide dismutase gene) and feoB1 (ferrous transport protein B1 gene) were markedly reduced...... in cultures at 0.5% O2 compared to those at higher oxygen tensions. Moreover, expression of katG (catalase-peroxidase gene) and feoB2 (ferrous transport protein B2 gene) was reduced markedly by iron addition, regardless of oxygen conditions. The data provides a greater understanding of molecular response...

  12. Effective utilization of B20 blend with diethyl ether and ethanol as oxygenated additives

    Directory of Open Access Journals (Sweden)

    Upadrasta-Satya Vara-Prasad

    2011-01-01

    Full Text Available In the recent times' fatty acid methyl ester popularly called as biodiesel has become more prominent alternate fuel for compression ignition engines based on a single fuel concept. Since, use of neat biodiesel on a large scale is raising certain difficulties and is being adopted in a blended form with petro-diesel fuel and B20 blend has become standardized. However, the HC and NOx emissions of B20 are still on the higher side. Present work aims at experimental evaluation of a single cylinder water-cooled diesel engine by adopting various proportions of ethanol and diethyl ether blends in order to improve performance and emission characteristics of B20 blend. Besides employing different amounts of ethanol and diethyl ether, simultaneous influence of injector nozzle hole size and fuel injection pressure are also investigated to arrive at an optimum configuration. Brake specific fuel consumption and hydrocarbon emissions values are lower with B20 and DEE 5 whereas B20 with DEE15 yielded lower NOx emissions. It is observed that addition of oxygenates have improved the combustion process and lower emissions are obtained. The present investigation revealed that blends with oxygenated additives having higher Cetane rating are superior to neat blend.

  13. Effect of additive oxygen gas on cellular response of lung cancer cells induced by atmospheric pressure helium plasma jet.

    Science.gov (United States)

    Joh, Hea Min; Choi, Ji Ye; Kim, Sun Ja; Chung, T H; Kang, Tae-Hong

    2014-10-16

    The atmospheric pressure helium plasma jet driven by pulsed dc voltage was utilized to treat human lung cancer cells in vitro. The properties of plasma plume were adjusted by the injection type and flow rate of additive oxygen gas in atmospheric pressure helium plasma jet. The plasma characteristics such as plume length, electric current and optical emission spectra (OES) were measured at different flow rates of additive oxygen to helium. The plasma plume length and total current decreased with an increase in the additive oxygen flow rate. The electron excitation temperature estimated by the Boltzmann plot from several excited helium emission lines increased slightly with the additive oxygen flow. The oxygen atom density in the gas phase estimated by actinometry utilizing argon was observed to increase with the additive oxygen flow. The concentration of intracellular reactive oxygen species (ROS) measured by fluorescence assay was found to be not exactly proportional to that of extracellular ROS (measured by OES), but both correlated considerably. It was also observed that the expression levels of p53 and the phospho-p53 were enhanced in the presence of additive oxygen flow compared with those from the pure helium plasma treatment.

  14. LIFE Chamber Chemical Equilibrium Simulations with Additive Hydrogen, Oxygen, and Nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    DeMuth, J A; Simon, A J

    2009-09-03

    In order to enable continuous operation of a Laser Inertial confinement Fusion Energy (LIFE) engine, the material (fill-gas and debris) in the fusion chamber must be carefully managed. The chamber chemical equilibrium compositions for post-shot mixtures are evaluated to determine what compounds will be formed at temperatures 300-5000K. It is desired to know if carbon and or lead will deposit on the walls of the chamber, and if so: at what temperature, and what elements can be added to prevent this from happening. The simulation was conducted using the chemical equilibrium solver Cantera with a Matlab front-end. Solutions were obtained by running equilibrations at constant temperature and constant specific volume over the specified range of temperatures. It was found that if nothing is done, carbon will deposit on the walls once it cools to below 2138K, and lead below 838K. Three solutions to capture the carbon were found: adding pure oxygen, hydrogen/nitrogen combo, and adding pure nitrogen. The best of these was the addition of oxygen which would readily form CO at around 4000K. To determine the temperature at which carbon would deposit on the walls, temperature solutions to evaporation rate equations needed to be found. To determine how much carbon or any species was in the chamber at a given time, chamber flushing equations needed to be developed. Major concerns are deposition of carbon and/or oxygen on the tungsten walls forming tungsten oxides or tungsten carbide which could cause embrittlement and cause failure of the first wall. Further research is needed.

  15. Additives to reduce susceptibility of thermosets and thermoplastics to erosion from atomic oxygen

    Science.gov (United States)

    Orwoll, Robert A.

    1990-01-01

    Polymeric materials have many attractive features such as light weight, high strength, and broad applicability in the form of films, fibers, and molded objects. In low earth orbit (LEO), these materials, when exposed on the exterior of the spacecraft, have the serious disadvantage of being susceptible to erosion by atomic oxygen (AO). AO is the most common chemical species at LEO altitudes. AO can be an extremely efficient oxidizing agent as was apparent from the extensive erosion of organic films exposed in STS missions. The mechanism for erosion involves the reaction of oxygen atoms at the surface of the substrate to form small molecular species. The susceptibility of polymeric materials varies with their chemical composition. Films with silicon atoms incorporated in the molecular structures have large coefficients of thermal expansion. This limits their utility. In an alternative approach additives were sought that mix physically and form a protective oxide layer when the film is exposed to AO. A large number of organic compounds containing silicon, germanium, or tin atoms were screened. Most were found to have very limited solubility in the polyetherimide (Ultem) films that were being protected from AO. However, one, bis(triphenyl tin) oxide, (BTO), is miscible in Ultem up to about 25 percent. Films of Ultem polyimide containing up to 25 wt percent BTO were prepared by evaporation of solvent from a solution of Ultem and BTO. The effects of AO on these films were simulated in the oxygen atmosphere of a radio frequency glow-discharge chamber. In the second part of this study, atoms were incorporated in epoxy resins. Experiments are in progress to measure the resistance of films of the cured epoxy to AO in the discharge chamber.

  16. Treatment of enterococcus faecalis bacteria by a helium atmospheric cold plasma brush with oxygen addition

    Science.gov (United States)

    Chen, Wei; Huang, Jun; Du, Ning; Liu, Xiao-Di; Wang, Xing-Quan; Lv, Guo-Hua; Zhang, Guo-Ping; Guo, Li-Hong; Yang, Si-Ze

    2012-07-01

    An atmospheric cold plasma brush suitable for large area and low-temperature plasma-based sterilization is designed. Results demonstrate that the He/O2 plasma more effectively kills Enterococcus faecalis than the pure He plasma. In addition, the sterilization efficiency values of the He/O2 plasma depend on the oxygen fraction in Helium gas. The atmospheric cold plasma brush using a proper ratio of He/O2 (2.5%) reaches the optimum sterilization efficiency. After plasma treatment, the cell structure and morphology changes can be observed by the scanning electron microscopy. Optical emission measurements indicate that reactive species such as O and OH play a significant role in the sterilization process.

  17. Treatment of enterococcus faecalis bacteria by a helium atmospheric cold plasma brush with oxygen addition

    Energy Technology Data Exchange (ETDEWEB)

    Chen Wei; Huang Jun; Wang Xingquan; Lv Guohua; Zhang Guoping [Key Laboratory of Soft Matter Physics, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, 100190 Beijing (China); Du Ning; Liu Xiaodi; Guo Lihong [Department of Oral Biology, Peking University School and Hospital of Stomatology, 100080 Beijing (China); Yang Size [Key Laboratory of Soft Matter Physics, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, 100190 Beijing (China); Fujian Key Laboratory for Plasma and Magnetic Resonance, Department of Aeronautics, School of Physics and Mechanical and Electrical Engineering, Xiamen University, Xiamen 361005 (China)

    2012-07-01

    An atmospheric cold plasma brush suitable for large area and low-temperature plasma-based sterilization is designed. Results demonstrate that the He/O{sub 2} plasma more effectively kills Enterococcus faecalis than the pure He plasma. In addition, the sterilization efficiency values of the He/O{sub 2} plasma depend on the oxygen fraction in Helium gas. The atmospheric cold plasma brush using a proper ratio of He/O{sub 2} (2.5%) reaches the optimum sterilization efficiency. After plasma treatment, the cell structure and morphology changes can be observed by the scanning electron microscopy. Optical emission measurements indicate that reactive species such as O and OH play a significant role in the sterilization process.

  18. Functional State Modelling of Cultivation Processes: Dissolved Oxygen Limitation State

    Directory of Open Access Journals (Sweden)

    Olympia Roeva

    2015-04-01

    Full Text Available A new functional state, namely dissolved oxygen limitation state for both bacteria Escherichia coli and yeast Saccharomyces cerevisiae fed-batch cultivation processes is presented in this study. Functional state modelling approach is applied to cultivation processes in order to overcome the main disadvantages of using global process model, namely complex model structure and a big number of model parameters. Alongwith the newly introduced dissolved oxygen limitation state, second acetate production state and first acetate production state are recognized during the fed-batch cultivation of E. coli, while mixed oxidative state and first ethanol production state are recognized during the fed-batch cultivation of S. cerevisiae. For all mentioned above functional states both structural and parameter identification is here performed based on experimental data of E. coli and S. cerevisiae fed-batch cultivations.

  19. Some new addition formulae for Weierstrass elliptic functions.

    Science.gov (United States)

    Eilbeck, J Chris; England, Matthew; Onishi, Yoshihiro

    2014-11-08

    We present new addition formulae for the Weierstrass functions associated with a general elliptic curve. We prove the structure of the formulae in n-variables and give the explicit addition formulae for the 2- and 3-variable cases. These new results were inspired by new addition formulae found in the case of an equianharmonic curve, which we can now observe as a specialization of the results here. The new formulae, and the techniques used to find them, also follow the recent work for the generalization of Weierstrass functions to curves of higher genus.

  20. Additive sensitization of bacterial spores by oxygen and p-nitroacetophenone

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, D.

    1978-01-01

    Ib the bacterial spore, the sensitizing effects of both oxygen and p-nitroacetophenone (PNAP) can be separated into components. Each sensitizer has a component of damage which involves reactions of hydroxyl radicals (.OH), although the origins of these components may be different. Tests which use different concentrations of PNAP and O/sub 2/ simultaneously have been run to seek interactions or additives in their effects on lethal radiation sensitivity. The results show that the effects of the PNAP ''non-.OH'' component are additive to those of both O/sub 2/ ''non-.OH'' components; however, the patterns of this additivity suggest that the chemical processes through which PNAP acts are similar to those of the high-O/sub 2/ component (that is, the component which occurs at (O/sub 2/) > 5 x 10/sup -5/ M) but are different from those of the low-O/sub 2/ component. There is also indirect evidence that the sensitizing reactions of the high-O/sub 2/ component may replace those reactions of hydroxyl radicals which occur at lower (O/sub 2/). If O/sub 2/ does replace .OH in some damaging chemical reactions, the unexpected disappearance of the .OH component as the (O/sub 2/) is raised would be understandable.

  1. Effectiveness of oxygen enriched hydrogen-HHO gas addition on DI diesel engine performance, emission and combustion characteristics

    National Research Council Canada - National Science Library

    Premkartikkumar S.R; Annamalai K; Pradeepkumar A.R

    2014-01-01

    Nowadays, more researches focus on protecting the environment. Present investigation concern with the effectiveness of Oxygen Enriched hydrogen- HHO gas addition on performance, emission and combustion characteristics of a DI diesel engine...

  2. In Situ Exfoliated, Edge-Rich, Oxygen-Functionalized Graphene from Carbon Fibers for Oxygen Electrocatalysis.

    Science.gov (United States)

    Liu, Zhijuan; Zhao, Zhenghang; Wang, Yanyong; Dou, Shuo; Yan, Dafeng; Liu, Dongdong; Xia, Zhenhai; Wang, Shuangyin

    2017-03-09

    Metal-free electrocatalysts have been extensively developed to replace noble metal Pt and RuO2 catalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in fuel cells or metal-air batteries. These electrocatalysts are usually deposited on a 3D conductive support (e.g., carbon paper or carbon cloth (CC)) to facilitate mass and electron transport. For practical applications, it is desirable to create in situ catalysts on the carbon fiber support to simplify the fabrication process for catalytic electrodes. In this study, the first example of in situ exfoliated, edge-rich, oxygen-functionalized graphene on the surface of carbon fibers using Ar plasma treatment is successfully prepared. Compared to pristine CC, the plasma-etched carbon cloth (P-CC) has a higher specific surface area and an increased number of active sites for OER and ORR. P-CC also displays good intrinsic electron conductivity and excellent mass transport. Theoretical studies show that P-CC has a low overpotential that is comparable to Pt-based catalysts, as a result of both defects and oxygen doping. This study provides a simple and effective approach for producing highly active in situ catalysts on a carbon support for OER and ORR.

  3. Oxygen functional groups in graphitic carbon nitride for enhanced photocatalysis.

    Science.gov (United States)

    Liu, Shizhen; Li, Degang; Sun, Hongqi; Ang, Ha Ming; Tadé, Moses O; Wang, Shaobin

    2016-04-15

    Metal-free semiconductors offer a new opportunity for environmental photocatalysis toward a potential breakthrough in high photo efficiency with complete prevention of metal leaching. In this study, graphitic carbon nitride (GCN) modified by oxygen functional groups was synthesized by a hydrothermal treatment of pristine GCN at different temperatures with H2O2. Insights into the emerging characteristics of the modified GCN in photocatalysis were obtained by determining the optical properties, band structure, electrochemical activity and pollutant degradation efficiency. It was found that the introduction of GCN with oxygen functional groups can enhance light absorption and accelerate electron transfer so as to improve the photocatalytic reaction efficiency. The photoinduced reactive radicals and the associated photodegradation were investigated by in situ electron paramagnetic resonance (EPR). The reactive radicals, O2(-) and OH, were responsible for organic degradation.

  4. Competition Kinetics of the Nonbranched-Chain Addition of Free Radicals to Olefins, Formaldehyde, and Oxygen

    Directory of Open Access Journals (Sweden)

    M. M. Silaev

    2011-01-01

    Full Text Available Five reaction schemes are suggested for the initiated nonbranched-chain addition of free radicals to the multiple bonds of alkenes, formaldehyde, and oxygen. The schemes include reactions competing with chain propagation through a reactive free radical. The chain evolution stage in these schemes involves three or four types of free radicals. One of them— CH2=C(CH3•CH2, CH2=CH•CHOH, H•C=O, −CH3C6H4CH2O•4, or HO•4—is relatively low-reactive and inhibits the chain process by shortening of the kinetic chain length. Based on the suggested schemes, nine rate equations containing one to three parameters to be determined directly are set up using quasi-steady-state treatment. These equations provide good fits for the nonmonotonic (peaking dependences of the formation rates of the molecular addition products (1 : 1 adducts on the concentration of the unsaturated component in liquid homogeneous binary systems consisting of a saturated component (hydrocarbon, alcohol, etc. and an unsaturated component (olefin, formaldehyde, or dioxygen. The unsaturated compound in these systems is both a reactant and an autoinhibitor generating low-reactive free radicals. A similar kinetic description is applicable to nonbranched-chain free-radical hydrogen oxidation. The energetics of the key radical-molecule reactions is considered.

  5. Reactive Oxygen Species and Dopamine Receptor Function in Essential Hypertension

    OpenAIRE

    ZENG, Chunyu; Villar, Van Anthony M.; Yu, Peiying; Zhou, Lin; Pedro A. Jose

    2009-01-01

    Essential hypertension is a major risk factor for stroke, myocardial infarction, and heart and kidney failure. Dopamine plays an important role in the pathogenesis of hypertension by regulating epithelial sodium transport and by interacting with vasoactive hormones and humoral factors. However, the mechanisms leading to impaired dopamine receptor function in hypertension states are not clear. Compelling experimental evidence indicates a role of reactive oxygen species (ROS) in hypertension, a...

  6. On Addition Formulae for Sigma Functions of Telescopic Curves

    Directory of Open Access Journals (Sweden)

    Takanori Ayano

    2013-06-01

    Full Text Available A telescopic curve is a certain algebraic curve defined by m−1 equations in the affine space of dimension m, which can be a hyperelliptic curve and an (n,s curve as a special case. We extend the addition formulae for sigma functions of (n,s curves to those of telescopic curves. The expression of the prime form in terms of the derivative of the sigma function is also given.

  7. Effects of dissolved oxygen concentration and iron addition on immediate-early gene expression of Magnetospirillum gryphiswaldense MSR-1.

    Science.gov (United States)

    Zhuang, Shiwen; Anyaogu, Diana Chinyere; Kasama, Takeshi; Workman, Mhairi; Mortensen, Uffe Hasbro; Hobley, Timothy John

    2017-06-15

    We report the effects of dissolved oxygen (DO) concentration and iron addition on gene expression of Magnetospirillum gryphiswaldense MSR-1 cells during fermentations, focusing on 0.25-24 h after iron addition. The DO was strictly controlled at 0.5% or 5% O2, and compared with aerobic condition. Uptake of iron (and formation of magnetosomes) was only observed in the 0.5% O2 condition where there was little difference in cell growth and carbon consumption compared to the 5% O2 condition. Quantitative reverse transcription PCR analysis showed a rapid (within 0.25 h) genetic response of MSR-1 cells after iron addition for all the genes studied, except for MgFnr (oxygen sensor gene) and fur (ferric uptake regulator family gene), and which in some cases was oxygen dependent. In particular, expression of sodB1 (superoxide dismutase gene) and feoB1 (ferrous transport protein B1 gene) was markedly reduced in cultures at 0.5% O2 compared to those at higher oxygen tensions. Moreover, expression of katG (catalase-peroxidase gene) and feoB2 (ferrous transport protein B2 gene) was reduced markedly by iron addition, regardless of oxygen conditions. These data provide a greater understanding of molecular response of MSR-1 cells to environmental conditions associated with oxygen and iron metabolisms, especially relevant to immediate-early stage of fermentation. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Stimulation of aerobic degradation of bentazone, mecoprop and dichlorprop by oxygen addition to aquifer sediment

    DEFF Research Database (Denmark)

    Levi, Suzi; Hybel, Anne-Marie; Bjerg, Poul Løgstrup

    2014-01-01

    In order to investigate aerobic degradation potential for the herbicides bentazone, mecoprop and dichlorprop, anaerobic groundwater samples from two monitoring and three drinking water wells near a drinking water abstraction field in Nybølle, Denmark, were screened for their degradation potential...... in microcosms using groundwater and sandy aquifer materials. To maintain a certain oxygen concentration this level was measured from the outside of the bottles with a fibre oxygen meter using oxygen-sensitive luminescent sensor foil mounted inside the microcosm, to which supplementary oxygen was added...... to the oxidation of organic matter and other reduced species such as Fe2+, S2- and Mn in sediment before the biodegradation of herbicides takes place. This study suggests that oxygen enhancement around a drinking water abstraction field could stimulate the bioremediation of diffuse source contamination. © 2013 ....

  9. Group additive values for the gas-phase standard enthalpy of formation, entropy and heat capacity of oxygenates.

    Science.gov (United States)

    Paraskevas, Paschalis D; Sabbe, Maarten K; Reyniers, Marie-Françoise; Papayannakos, Nikos; Marin, Guy B

    2013-11-25

    A complete and consistent set of 60 Benson group additive values (GAVs) for oxygenate molecules and 97 GAVs for oxygenate radicals is provided, which allow to describe their standard enthalpies of formation, entropies and heat capacities. Approximately half of the GAVs for oxygenate molecules and the majority of the GAVs for oxygenate radicals have not been reported before. The values are derived from an extensive and accurate database of thermochemical data obtained by ab initio calculations at the CBS-QB3 level of theory for 202 molecules and 248 radicals. These compounds include saturated and unsaturated, α- and β-branched, mono- and bifunctional oxygenates. Internal rotations were accounted for by using one-dimensional hindered rotor corrections. The accuracy of the database was further improved by adding bond additive corrections to the CBS-QB3 standard enthalpies of formation. Furthermore, 14 corrections for non-nearest-neighbor interactions (NNI) were introduced for molecules and 12 for radicals. The validity of the constructed group additive model was established by comparing the predicted values with both ab initio calculated values and experimental data for oxygenates and oxygenate radicals. The group additive method predicts standard enthalpies of formation, entropies, and heat capacities with chemical accuracy, respectively, within 4 kJ mol(-1) and 4 J mol(-1) K(-1) for both ab initio calculated and experimental values. As an alternative, the hydrogen bond increment (HBI) method developed by Lay et al. (T. H. Lay, J. W. Bozzelli, A. M. Dean, E. R. Ritter, J. Phys. Chem.- 1995, 99, 14514) was used to introduce 77 new HBI structures and to calculate their thermodynamic parameters (Δ(f)H°, S°, C(p)°). The GAVs reported in this work can be reliably used for the prediction of thermochemical data for large oxygenate compounds, combining rapid prediction with wide-ranging application.

  10. Addition of oxygen to and distribution of oxides in tantalum alloy T-111 at low concentrations

    Science.gov (United States)

    Stecura, S.

    1975-01-01

    Oxygen was added at 820 and 990 C at an oxygen pressure of about .0003 torr. The technique permitted predetermined and reproducible oxygen doping of the tantalum alloy (T-111). Based on the temperature dependency of the doping reaction, it was concluded that the initial rates of oxygen pickup are probably controlled by solution of oxygen into the T-111 lattice. Although hafnium oxides are more stable than those of tantalum or tungsten, analyses of extracted residues indicate that the tantalum and tungsten oxides predominate in the as-doped specimens, presumably because of the higher concentrations of tantalum and tungsten in the alloy. However, high-temperature annealing promotes gettering of dissolved oxygen and oxygen from other oxides to form hafnium oxides. Small amounts of tantalum and tungsten oxides were still present after high temperature annealing. Tungsten oxide (WO3) volatilizes slightly from the surface of T-111 at 990 C but not at 820 C. The vaporization of WO3 has no apparent effect on the doping reaction.

  11. Reactive oxygen species and dopamine receptor function in essential hypertension.

    Science.gov (United States)

    Zeng, Chunyu; Villar, Van Anthony M; Yu, Peiying; Zhou, Lin; Jose, Pedro A

    2009-04-01

    Essential hypertension is a major risk factor for stroke, myocardial infarction, and heart and kidney failure. Dopamine plays an important role in the pathogenesis of hypertension by regulating epithelial sodium transport and by interacting with vasoactive hormones and humoral factors. However, the mechanisms leading to impaired dopamine receptor function in hypertension states are not clear. Compelling experimental evidence indicates a role of reactive oxygen species (ROS) in hypertension, and there are increasing pieces of evidence showing that in conditions associated with oxidative stress, which is present in hypertensive states, dopamine receptor effects, such as natriuresis, diuresis, and vasodilation, are impaired. The goal of this review is to present experimental evidence that has led to the conclusion that decreased dopamine receptor function increases ROS activity and vice versa. Decreased dopamine receptor function and increased ROS production, working in concert or independent of each other, contribute to the pathogenesis of essential hypertension.

  12. Nitric oxide and reactive oxygen species in limb vascular function

    DEFF Research Database (Denmark)

    Gliemann, Lasse; Nyberg, Michael Permin; Hellsten, Ylva

    2014-01-01

    Abstract Nitric oxide (NO) is known to be one of the most important regulatory compounds within the cardiovascular system where it is central for functions such as regulation of blood pressure, blood flow and vascular growth. The bioavailability of NO is determined by a balance between, on one hand......, the extent of enzymatic and non-enzymatic formation of NO and on the other hand, removal of NO, which in part is dependent on the reaction of NO with reactive oxygen species (ROS). The presence of ROS is dependent on the extent of ROS formation via mitochondria and/or enzymes such as NAD(P)H oxidase...

  13. Spent yeast as natural source of functional food additives

    Science.gov (United States)

    Rakowska, Rita; Sadowska, Anna; Dybkowska, Ewa; Świderski, Franciszek

    Spent yeasts are by-products arising from beer and wine production which over many years have been chiefly used as feed additives for livestock. They contain many valuable and bioactive substances which has thereby generated much interest in their exploitation. Up till now, the main products obtained from beer-brewing yeasts are β-glucans and yeast extracts. Other like foodstuffs include dried brewer’s yeast, where this is dried and the bitterness removed to be fit for human consumption as well as mannan-oligosaccharides hitherto used in the feed industry. β-glucans constitute the building blocks of yeast cell walls and can thus be used in human nutrition as dietary supplements or serving as food additives in functional foods. β-glucans products obtained via post-fermentation of beer also exhibit a high and multi-faceted biological activity where they improve the blood’s lipid profile, enhance immunological status and have both prebiotic and anti-oxidant properties. Yeast extracts are currently being used more and more to enhance flavour in foodstuffs, particularly for meat and its products. Depending on how autolysis is carried out, it is possible to design extracts of various meat flavours characteristic of specific meats. Many different flavour profiles can be created which may be additionally increased in combination with vegetable extracts. Within the food market, yeast extracts can appear in various guises such as liquids, pastes or powders. They all contain significant amounts of glutamic acid, 5’-GMP and 5’-IMP nucleotides together with various amino acids and peptides that act synergistically for enhancing the flavour of foodstuff products. Recent studies have demonstrated additional benefits of yeast extracts as valuable sources of amino acids and peptides which can be used in functional foods and dietary supplements. These products possess GRAS status (Generally Recognised As Safe) which thereby also adds further as to why they should be used

  14. Increasing component functionality via multi-process additive manufacturing

    Science.gov (United States)

    Coronel, Jose L.; Fehr, Katherine H.; Kelly, Dominic D.; Espalin, David; Wicker, Ryan B.

    2017-05-01

    Additively manufactured components, although extensively customizable, are often limited in functionality. Multi-process additive manufacturing (AM) grants the ability to increase the functionality of components via subtractive manufacturing, wire embedding, foil embedding and pick and place. These processes are scalable to include several platforms ranging from desktop to large area printers. The Multi3D System is highlighted, possessing the capability to perform the above mentioned processes, all while transferring a fabricated component with a robotic arm. Work was conducted to fabricate a patent inspired, printed missile seeker. The seeker demonstrated the advantage of multi-process AM via introduction of the pick and place process. Wire embedding was also explored, with the successful interconnect of two layers of embedded wires in different planes. A final demonstration of a printed contour bracket, served to show the reduction of surface roughness on a printed part is 87.5% when subtractive manufacturing is implemented in tandem with AM. Functionality of the components on all the cases was improved. Results included optical components embedded within the printed housing, wires embedded with interconnection, and reduced surface roughness. These results highlight the improved functionality of components through multi-process AM, specifically through work conducted with the Multi3D System.

  15. Effectiveness of oxygen enriched hydrogen-HHO gas addition on DI diesel engine performance, emission and combustion characteristics

    Directory of Open Access Journals (Sweden)

    Premkartikkumar S.R.

    2014-01-01

    Full Text Available Nowadays, more researches focus on protecting the environment. Present investigation concern with the effectiveness of Oxygen Enriched hydrogen- HHO gas addition on performance, emission and combustion characteristics of a DI diesel engine. Here the Oxygen Enriched hydrogen-HHO gas was produced by the process of water electrolysis. When potential difference is applied across the anode and cathode electrodes of the electrolyzer, water is transmuted into Oxygen Enriched hydrogen-HHO gas. The produced gas was aspirated into the cylinder along with intake air at the flow rates of 1 lpm and 3.3 lpm. The results show that when Oxygen Enriched hydrogen-HHO gas was inducted, the brake thermal efficiency of the engine increased by 11.06%, Carbon monoxide decreased by 15.38%, Unburned hydrocarbon decreased by 18.18%, Carbon dioxide increased by 6.06%, however, the NOX emission increased by 11.19%.

  16. Enhanced energy capacity of lithium-oxygen batteries with ionic liquid electrolytes by addition of ammonium ions

    Science.gov (United States)

    Matsuda, Shoichi; Uosaki, Kohei; Nakanishi, Shuji

    2017-07-01

    Lithium-oxygen (Li-O2) batteries with ionic liquid-based electrolytes have attracted much attention because of their superior battery performance and high safety. However, the practical energy capacities achieved to date are markedly lower than those of Li-ion batteries. A dominant factor that limits the energy capacities of Li-O2 batteries is the insulating characteristics and insolubility of lithium peroxide (Li2O2), which gradually accumulates on the positive electrode as a discharge product. Herein, we report that ammonium ions function as a promoter for the solution-route formation of Li2O2, which results in a significant improvement of the energy capacity of Li-O2 cells. Scanning electron microscopy analyses revealed that the structure of Li2O2 changed from spherical particles to toroidal particles with an increase in the ammonium ions concentration. Ionic additives that have been reported to function as promoters the solution-route formation of Li2O2 in ether-based electrolyte systems do not exhibit a promoting effect in ionic liquid-based electrolytes.

  17. Electrolysis cell functions as water vapor dehumidifier and oxygen generator

    Science.gov (United States)

    Clifford, J. E.

    1971-01-01

    Water vapor is absorbed in hygroscopic electrolyte, and oxygen generated by absorbed water electrolysis at anode is added simultaneously to air stream. Cell applications include on-board aircraft oxygen systems, portable oxygen generators, oxygen concentration requirements, and commercial air conditioning and dehumidifying systems.

  18. Oxygen plasma functionalization of poly(p-phenilene sulphide)

    Energy Technology Data Exchange (ETDEWEB)

    Cvelbar, Uros [Department F4, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia)]. E-mail: uros.cvelbar@guest.arnes.si; Mozetic, Miran [Department F4, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Junkar, Ita [Department F4, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Vesel, Alenka [Department F4, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Kovac, Janez [Department F4, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Drenik, Aleksander [Department F4, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Vrlinic, Tjasa [Department F4, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Hauptman, Nina [National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); Klanjsek-Gunde, Marta [National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); Markoli, Bostjan [Faculty of Natural Sciences and Engineering, University of Ljubljana, Askrceva 12, 1000 Ljubljana (Slovenia); Krstulovic, Niksa [Institute of Physics, Bijenicka 56, 10000 Zagreb (Croatia); Milosevic, Slobodan [Institute of Physics, Bijenicka 56, 10000 Zagreb (Croatia); Gaboriau, Freddy [Laplace, University Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse (France); Belmonte, Thierry [Laboratoire de Science et Genie des Surfaces, Ecole de Mines, Parc de Saurupt, 54042 Nancy (France)

    2007-08-31

    Surface effects during plasma activation of poly(p-phenilene sulphide)-PPS have been studied. Samples that were exposed to weakly ionized highly dissociated oxygen plasma created an inductively coupled radiofrequency discharge with the power of 100 W. The electron density and temperature were measured with a double Langmuir probe and were 4 x 10{sup 15} m{sup -3} and 3 eV, respectively, while the neutral atom density was measured with a fiber optics catalytic probe and was 4 x 10{sup 21} m{sup -3}. The surface tension was determined by measuring the contact angle of deionized water, while the appearance of surface functional groups was detected by XPS. The surface tension of untreated PPS was 7 x 10{sup -3} N/m or/and increased to 7 x 10{sup -2} N/m in few seconds of plasma treatment. It remained fairly constant for longer plasma treatments. The XPS survey spectrum showed little oxygen on untreated samples, but its concentration increased to about 20 at.% in few seconds. Detailed high resolution XPS C 1s peak showed that the carbon was left fairly stable during plasma treatment. The main functional groups formed were rather sulphate in sulphite groups, as determined from high resolution S 2p peak. Namely, a strong transition from sulphide to sulphate state of sulfur was observed. The spontaneous deactivation of the polymer surface was measured as well. The deactivation was fairly logarithmic with the characteristic decay time of several hours.

  19. Oxygenation of the portal vein by intraperitoneal administration of oxygenated perfluorochemical improves the engraftment and function of intraportally transplanted islets.

    Science.gov (United States)

    Sakai, Tetsuya; Li, Shiri; Kuroda, Yoshikazu; Tanioka, Yasuki; Fujino, Yasuhiro; Suzuki, Yasuyuki

    2011-04-01

    One of the major obstacles for successful intraportal islet transplantation (IPIT) is early graft loss due to hypoxia. We therefore examined the effect of intraperitoneal oxygenated perfluorochemical (PFC) on oxygenation of the portal vein with respect to islet engraftment and function after IPIT in a rat model. First, we measured the oxygen tension and saturation in the portal vein of Lewis rats before and after intraperitoneal injection of oxygenated PFC. Second, blood glucose levels, glucose tolerance, and the number of surviving islets were measured after IPIT with oxygenated PFC (group 1), with PFC saturated by nitrogen (group 2), and without any PFC (control). Both oxygen tension and saturation in the portal vein significantly increased after injection of oxygenated PFC. In IPIT, the functional success rate in group 1 was 83.3%, compared with 16.7% in group 2 and 16.7% in the control. On the 28th posttransplantation day, the number of engrafted islets in the liver in group 1 (12.8 [SD, 3.3]) was significantly higher than that in group 2 (4.7 [SD, 3.0]) and in the control group (6.5 [SD, 3.3]). We clearly demonstrated the effect of intraperitoneal oxygenated PFC on oxygenation of the portal vein, resulting in better IPIT outcomes.

  20. Plant for producing an oxygen-containing additive as an ecologically beneficial component for liquid motor fuels

    Science.gov (United States)

    Siryk, Yury Paul; Balytski, Ivan Peter; Korolyov, Volodymyr George; Klishyn, Olexiy Nick; Lnianiy, Vitaly Nick; Lyakh, Yury Alex; Rogulin, Victor Valery

    2013-04-30

    A plant for producing an oxygen-containing additive for liquid motor fuels comprises an anaerobic fermentation vessel, a gasholder, a system for removal of sulphuretted hydrogen, and a hotwell. The plant further comprises an aerobic fermentation vessel, a device for liquid substance pumping, a device for liquid aeration with an oxygen-containing gas, a removal system of solid mass residue after fermentation, a gas distribution device; a device for heavy gases utilization; a device for ammonia adsorption by water; a liquid-gas mixer; a cavity mixer, a system that serves superficial active and dispersant matters and a cooler; all of these being connected to each other by pipelines. The technical result being the implementation of a process for producing an oxygen containing additive, which after being added to liquid motor fuels, provides an ecologically beneficial component for motor fuels by ensuring the stability of composition fuel properties during long-term storage.

  1. REPRESENTATION OF ADDITIVE FUNCTIONALS AND LOCAL TIMES FOR JUMP MARKOV PROCESSES AND THEIR FUNCTIONAL LIMIT THEOREM

    Institute of Scientific and Technical Information of China (English)

    蒋义文; 刘禄勤

    2003-01-01

    The representation of additive functionals and local times for jump Markovprocesses are obtained. The results of uniformly functional moderate deviation and theirapplications to birth-death processes are also presented.

  2. 77 FR 63217 - Use of Additional Portable Oxygen Concentrators on Board Aircraft

    Science.gov (United States)

    2012-10-16

    ... manufacturer's names (International Biophysics Corporation's LifeChoice and Delphi Medical Systems' RS-00400...Choice and Delphi Medical Systems' RS-00400) back to the list of approved POCs in SFAR 106. Waiver of...: This action amends the FAA's rules for permitting limited use of portable oxygen concentrator...

  3. 75 FR 739 - Use of Additional Portable Oxygen Concentrator Devices on Board Aircraft

    Science.gov (United States)

    2010-01-06

    ... manner to add two more POC devices, Delphi Medical Systems' RS-00400 and Invacare Corporation's XPO2, to... documentation of the devices to the Department of Transportation's Docket Management System. That documentation... Aviation Regulation 106--Rules for Use of Portable Oxygen Concentrator Systems on Board...

  4. Effects of Oxygen Element and Oxygen-Containing Functional Groups on Surface Wettability of Coal Dust with Various Metamorphic Degrees Based on XPS Experiment.

    Science.gov (United States)

    Zhou, Gang; Xu, Cuicui; Cheng, Weimin; Zhang, Qi; Nie, Wen

    2015-01-01

    To investigate the difference of surface oxygen element and oxygen-containing functional groups among coal dusts with different metamorphic degrees and their influence on surface wettability, a series of X-ray photoelectron spectroscopy experiments on 6 coal samples are carried out. The result demonstrates that the O/C ratio of coal surface shows an overall increasing trend compared with the result of its elements analysis. As the metamorphic degree increases, the O/C ratio on the surface gradually declines and the hydrophilic groups tend to fall off from coal surface. It could be found that different coals show different surface distributions of carboxyl and hydroxyl which are considered as the greatest promoter to the wettability of coal surface. With the change of metamorphic degree, the distribution of ether group is irregular while the carbonyl distribution keeps stable. In general, as the metamorphic degree goes higher, the content of oxygen-containing polar group tends to reduce. According to the measurement results, the contact angle is negatively related to the content of oxygen element, surface oxygen, and polar groups. In addition, compared with surface oxygen content, the content of oxygen-containing polar group serves as a more reasonable indicator of coal dust wettability.

  5. Review on Advances of Functional Material for Additive Manufacturing

    Science.gov (United States)

    Zulkifli, Nur Amalina Binti; Akmal Johar, Muhammad; Faizan Marwah, Omar Mohd; Irwan Ibrahim, Mohd Halim

    2017-08-01

    The attempt of finding and making new materials in improving products that are already in the market are widely done by researchers nowadays. This project is focusing on making new materials for functional material through additive manufacturing application. The idea of this project came from the ability limitation of capacitor in market nowadays in storing higher charges but smaller in size. Powder glass is the new material that could to be used as a dielectric material for capacitor with the help of palm kernel oil as the binder. This paper reviews on applications done through additive manufacturing method and also types of functional materials used in this method previously. Structure of a capacitor, dielectric properties and measurement techniques that are trying to be carried out are also explains in this paper. Last part of this paper brief on the material proposal and reasons those materials are chosen. New dielectric material for capacitor which are able to store more charges but still small in size are expected to be produced as the outcome of this research.

  6. Work function modifications of graphite surface via oxygen plasma treatment

    Science.gov (United States)

    Duch, J.; Kubisiak, P.; Adolfsson, K. H.; Hakkarainen, M.; Golda-Cepa, M.; Kotarba, A.

    2017-10-01

    The surface modification of graphite by oxygen plasma was investigated experimentally (X-ray diffraction, nanoparticle tracking analysis, laser desorption ionization mass spectrometry, thermogravimetry, water contact angle) and by molecular modelling (Density Functional Theory). Generation of surface functional groups (mainly sbnd OHsurf) leads to substantial changes in electrodonor properties and wettability gauged by work function and water contact angle, respectively. The invoked modifications were analyzed in terms of Helmholtz model taking into account the theoretically determined surface dipole moment of graphite-OHsurf system (μ = 2.71 D) and experimentally measured work function increase (from 0.75 to 1.02 eV) to determine the sbnd OH surface coverage (from 0.70 to 1.03 × 1014 groups cm-2). Since the plasma treatment was confined to the surface, the high thermal stability of the graphite material was preserved as revealed by the thermogravimetric analysis. The obtained results provide a suitable quantitative background for tuning the key operating parameters of carbon electrodes: electronic properties, interaction with water and thermal stability.

  7. Density functional studies of functionalized graphitic materials with late transition metals for oxygen reduction reactions

    DEFF Research Database (Denmark)

    Vallejo, Federico Calle; Martinez, Jose Ignacio; Rossmeisl, Jan

    2011-01-01

    ) at the cathode. In this contribution, on the basis of Density Functional Theory (DFT) calculations, we show that graphitic materials with active sites composed of 4 nitrogen atoms and transition metal atoms belonging to groups 7 to 9 in the periodic table are active towards ORR, and also towards Oxygen Evolution...

  8. A dominant role of oxygen additive on cold atmospheric-pressure He + O{sub 2} plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Aijun; Liu, Dingxin, E-mail: liudingxin@gmail.com, E-mail: xhw@mail.xjtu.edu.cn; Rong, Mingzhe; Wang, Xiaohua, E-mail: liudingxin@gmail.com, E-mail: xhw@mail.xjtu.edu.cn [Centre for Plasma Biomedicine, State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China); Kong, Michael G. [Centre for Plasma Biomedicine, State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China); Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia 23508 (United States); Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, Virginia 23529 (United States)

    2014-08-15

    We present in this paper how oxygen additive impacts on the cold atmospheric-pressure helium plasmas by means of a one-dimensional fluid model. For the oxygen concentration [O{sub 2}] > ∼0.1%, the influence of oxygen on the electron characteristics and the power dissipation becomes important, e.g., the electron density, the electron temperature in sheath, the electron-coupling power, and the sheath width decreasing by 1.6 to 16 folds with a two-log increase in [O{sub 2}] from 0.1% to 10%. Also the discharge mode evolves from the γ mode to the α mode. The reactive oxygen species are found to peak in the narrow range of [O{sub 2}] = 0.4%–0.9% in the plasmas, similar to their power-coupling values. This applies to their wall fluxes except for those of O* and O{sub 2}{sup −}. These two species have very short lifetimes, thus only when generated in boundary layers within several micrometers next to the electrode can contribute to the fluxes. The dominant reactive oxygen species and the corresponding main reactions are schematically presented, and their relations are quantified for selected applications.

  9. Approximate Representation of a Class of Associative Functions by a Monotone 1-Place Function and Addition

    Institute of Scientific and Technical Information of China (English)

    李中夫; 刘应明

    1994-01-01

    This paper discusses the problem of simple representation of multi-place functions from the viewpoint of "simple approximation". We prove that a class of associative functions, which have a wide range of applications, can be approximately represented by a monotone 1-place function and addition.

  10. Influence of oxygen addition to the carrier gas on laser-induced breakdown spectroscopy measurements on aerosols

    Science.gov (United States)

    Palazzo, N.; Migliorini, F.; Dondè, R.; Maffi, S.; De Iuliis, S.

    2016-01-01

    In this work, laser-induced breakdown spectrosopy is implemented on aerosol particles for absolute concentration analysis. The aim of this work is the investigation of the effect of the bath gas used for nebulizing the aerosol. Nitrogen, air, and 50% O2 in N2 mixture have been chosen as carrier gasses in order to analyze the effect of oxygen addition to the gas. LIBS measurements have been carried out on aerosol particles produced from CuCl2 2H2O solutions, and the 324.7 nm Cu line is considered. As a first analysis, plasma parameters, such as temperature and electron density, have been evaluated changing the carrier gas. Measurements to derive the LIBS calibration curve of the 324.7 nm Cu line are carried out in air and in N2. The significant difference in the slope of the resulting calibration curves has to be attributed to the oxygen addition to the bath gas. To explore such behavior, time-resolved measurements of the Cu line and peak/base ratio have been performed. The presence of two competitive effects have been observed that becomes significant increasing the amount of oxygen in the carrier gas. One is the oxygen-quenching effect, already observed in the literature, and the other one is the enhancement of the Cu LIBS signal, expecially at short delay times. These effects have been observed also at other Cu lines and changing the analyte source. The results are presented and widely discussed.

  11. Representation functions of additive bases for abelian semigroups

    Directory of Open Access Journals (Sweden)

    Melvyn B. Nathanson

    2004-01-01

    function has only finitely many zeros. It is proved that for a large class of countably infinite abelian semigroups, there exists a basis whose representation function is exactly equal to the given function for every element in the semigroup.

  12. Addition of ammonia and/or oxygen to an ionic liquid for delignification of miscanthus.

    Science.gov (United States)

    Rodríguez, Héctor; Padmanabhan, Sasisanker; Poon, Geoffrey; Prausnitz, John M

    2011-09-01

    Ammonia and/or oxygen were used to enhance the delignification of miscanthus dissolved in 1-ethyl-3-methylimidazolium acetate at 140°C. After dissolution of the gas at 9 bar, water was added as antisolvent to regenerate the dissolved biomass. In a next step, an acetone/water mixture was used to remove carbohydrate-free lignin from the regenerated biomass. The lignin content in the final product was around 10%, much lower than the ca. 23% lignin content of the raw dry miscanthus. This lignin reduction is achieved without diminution of cellulose or of total carbohydrates recovered, relative to the recovery achieved with the ionic liquid pretreatment in contact with air or nitrogen.

  13. PWM-Statcom system additionally having active filter function

    Energy Technology Data Exchange (ETDEWEB)

    Matsui, K.; Kojima, H.; Yamamoto, I.; Hasegawa, M. [Chubu Univ., Kasugai Aichi (Japan); Ando, K. [Nitto Kogyo Corp., Nagakute, Aichi (Japan)

    2006-07-01

    The harmonic characteristics of static synchronous compensators (Statcom) were discussed with particular reference to the difference between symmetrical and asymmetrical modulation strategies that influence a quality of output waveform. The asymmetrical modulation strategy is the better approach in higher power factor applications such as alternating current (AC) motor drives. It was noted that in cases requiring a passive filter with a very large scale Statcom, a symmetrical modulation strategy is superior. Therefore, in this study, a symmetrical modulation was preferred for a neutral point clamped (NPC) pulse width modulation (PWM) inverter. Due to switching in a limited narrow frequency band, such output harmonics can be eliminated using a simple passive filter and harmonics such as the fifth and the seventh, can be suppressed using the proposed Statcom scheme in which the feedback signals for the fifth and seventh harmonics are injected into the Statcom. Using these feedback signals, the harmonics in the power system were significantly reduced. This result was also confirmed by simulation. It was concluded that, in addition to the proper operation of the Statcom, it is possible to perform an active filtering function . 10 refs., 1 tab., 9 figs.

  14. Vibrationally excited oxygen in the middle atmosphere. Evaluation of its potential as an additional source of ozone

    Energy Technology Data Exchange (ETDEWEB)

    Koppers, G.A.A.

    1996-11-01

    Ozone is `the` most important trace gas in the middle atmosphere. Despite the large efforts that have been made to calculate its concentration in the middle atmosphere there is long standing discrepancy between in-situ and remote sensing measurements on one hand and model results on the other. The latter tend to be about 30% too low in the upper stratosphere and mesosphere. One of the photolysis products of ozone itself, O2({upsilon}) - an oxygen molecule with extra vibrational energy, has been suggested as an intermediate in a reaction sequence that possibly could represent the missing ozone source. A key point in model calculations that estimate the magnitude of the proposed extra ozone source is the fractional population distribution of O2({upsilon}) after ozone photodissociation. Recent statistical calculations supply the vibrational distribution of O2({upsilon}) as a function of the wavelength at which ozone is dissociated. Based on these results a 2D chemical model that includes O2({upsilon}) chemistry has been used to investigate the importance of this mechanism. The extra ozone production by this mechanism has been compared for several other vibrational distributions taken from literature, different collisional deactivation rates of the excited oxygen fragments, and including a reaction between high vibrational excited oxygen with ground state oxygen producing two odd oxygen molecules. Our results indicate that regardless of whether the high vibrational reaction is included, alternatively the deactivation rates are decreased or not, the vibrational excited oxygen mechanism can not simultaneously match the absolute amount of the difference between the model results and SAGE II data and the height distribution of this difference. 23 refs, 17 figs, 2 tabs

  15. Functional properties of the oxygen evolving complex of photosystem II.

    NARCIS (Netherlands)

    Vliet, van P.H.

    1996-01-01

    This Thesis presents the results of a study by electron paramagnetic resonance (EPR) and measurements of oxygen evolution of the Oxygen Evolving Complex of Photosystem 11 (PS-II) in PS-II enriched membranes from spinach.The experimental part of this Thesis is preceded by a general introduction (Chap

  16. Reactive Oxygen Species as Additional Determinants for Cytotoxicity of Clostridium difficile Toxins A and B

    Directory of Open Access Journals (Sweden)

    Claudia Frädrich

    2016-01-01

    Full Text Available Clostridium difficile infections can induce mild to severe diarrhoea and the often associated characteristic pseudomembranous colitis. Two protein toxins, the large glucosyltransferases TcdA and TcdB, are the main pathogenicity factors that can induce all clinical symptoms in animal models. The classical molecular mode of action of these homologous toxins is the inhibition of Rho GTPases by mono-glucosylation. Rho-inhibition leads to breakdown of the actin cytoskeleton, induces stress-activated and pro-inflammatory signaling and eventually results in apoptosis of the affected cells. An increasing number of reports, however, have documented further qualities of TcdA and TcdB, including the production of reactive oxygen species (ROS by target cells. This review summarizes observations dealing with the production of ROS induced by TcdA and TcdB, dissects pathways that contribute to this phenomenon and speculates about ROS in mediating pathogenesis. In conclusion, ROS have to be considered as a discrete, glucosyltransferase-independent quality of at least TcdB, triggered by different mechanisms.

  17. No additive effects of inhaled iloprost and prone positioning on pulmonary hypertension and oxygenation in acute respiratory distress syndrome.

    Science.gov (United States)

    Senturk, E; Cakar, N; Ozcan, P E; Basel, A; Sengul, T; Telci, L; Esen, F; Nahum, A; Strang, C M; Winterhalter, M

    2012-09-01

    In acute respiratory distress syndrome (ARDS), pulmonary hypertension is associated with a poor prognosis. Prone position is effective to improve oxygenation whereas inhaled iloprost can treat pulmonary hypertension. However, combination of these interventions has not been examined before. The hypothesis was that this combination had additive effects on oxygenation and pulmonary hemodynamics as compared with each intervention alone. In a prospective, randomized cross-over study, ten pigs were anesthetized, intubated and ventilated with volume controlled ventilation. Carotid, jugular venous and pulmonary artery catheters were inserted. ARDS was induced with oleic acid (0.20 mL/kg). Measurements were repeated in randomized different sequences of prone or supine positions with or without iloprost inhalation (220 ng/kg/min) (four combinations). Systemic and pulmonary arterial pressures; arterial and mixed venous blood gases; and Qs/Qt and the resistances were recorded. Iloprost decreased pulmonary artery pressures (for MPAP: P=0.034) in both supine (37±10 vs. 31±8 mmHg; Piloprost application (331±112 vs. 167±117 mmHg, Piloprost reduced pulmonary arterial pressures, and prone positioning improved oxygenation; there are no additive effects of the combination of both interventions on both parameters. To treat both pulmonary hypertension and hypoxemia, application of iloprost in prone position is suggested.

  18. On the origin of regio- and stereoselectivity in singlet oxygen addition to enecarbamates.

    Science.gov (United States)

    Rajeev, Ramanan; Sunoj, Raghavan B

    2012-03-02

    The reactions of excited state singlet molecular oxygen ((1)Δ(g),(1)O(2)) continue to witness interesting new developments. In the most recent manifestation, (1)O(2) is tamed to react with enecarbamates in a stereoselective manner, which is remarkable, in view of its inherently high reactivity (Acc. Chem. Res. 2008, 41, 387). Herein, we employed the CAS-MP2(8,7)/6-31G* as well as the CAS-MP2(10,8)/6-31G* computations to unravel the origin of (i) diastereoselectivities in dioxetane or hydroperoxide formation and (ii) regioselectivity leading to a [2 + 2] cycloadduct or an ene product when (1)O(2) reacts with an oxazolidinone tethered 2-phenyl-1-propenyl system. The computed Gibbs free energy profiles for E- and Z-isomers when (1)O(2) approaches through the hindered and nonhindered diastereotopic faces (by virtue of chiral oxazolidinone) of the enecarbamates exhibit distinct differences. In the case of E-isomer, the relative energies of the transition structures responsible for hydroperoxide (ene product) are lower than that for dioxetane formation. On the other hand, the ene pathway is predicted to involve higher barriers as compared to the corresponding dioxetane pathway for Z-isomer. The energy difference between the rate-determining diastereomeric transition structures involved in the most favored ene reaction for E-enecarbamate suggests high diastereoselectivity. In contrast, the corresponding energy difference for Z-enecarbamate in the ene pathway is found to be diminishingly close, implying low diastereoselectivity. However, the dioxetane formation from Z-enecarbamate is predicted to exhibit high diastereoselectivity. The application of activation strain model as well as the differences in stereoelectronic effects in the stereocontrolling transition structures is found to be effective toward rationalizing the origin of selectivities reported herein. These predictions are found to be in excellent agreement with the experimental observations.

  19. Additional functions of remotely read kWh-meters

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, P. [VTT Energy, Espoo (Finland); Vehvilaeinen, S. [Mittrix Oy (Finland); Rantanen, J. [Helsinki Energy Board (Finland)

    1998-08-01

    In this chapter the possibilities to include new applications into remotely read smart kWh-meters are considered. New electronic meters can measure various electric quantities and have some extra calculating capacity. So they can be used to provide functions that distribution automation and the customer need and thus share the costs. Some applications like monitoring the state of the distribution network or locating faults are only for the utility, but many applications also need an interface to the customers or their automation systems. Among those are monitoring the quality of electricity, estimating load curves, applying dynamic tariffs and selling electricity and accounting. As a special item, the continuous monitoring of the quality of electricity is discussed. This includes voltage levels, total distortion, asymmetry and so on. If such a kWh-meter indicates quality problems it is possible to go there with a portable quality meter that is suitable for the case and inspect the situation. The poor quality can be detected before it causes harm to equipment owned by the customers or the power distribution company. This article also presents a prototype of such a quality monitoring kWh-meter. Dynamic tariffs and free electricity markets require two way communication with the utility and the customer and measurement of the time variations of the energy consumption. The customers or their energy management system must receive the energy prices from the utility and calculate the energy costs and decide upon the energy consumption control actions. Some alternative ways to meet these customer interface requirements are compared. Remote reading of kWh-meters requires a certain investment in meters and their data communication with the utility. Because smart meters can have some additional memory and calculating capacity and are capable of measuring various electric quantities, it is possible to share the costs with other applications that use the same hardware and data

  20. Functions of Propolis as a natural feed additive in poultry

    Science.gov (United States)

    Propolis is a resinous hive product collected by honeybees from various sources of plants. Numerous scientific investigations have been focused on the biological activities of propolis and its functions as a health supplement in humans. It could have similar function in other animals, such as poultr...

  1. ABOUT FOOD ADDITIVES AS IMPORTANT PART OF FUNCTIONAL FOOD

    OpenAIRE

    Umida Khodjaeva; Tatiana Bojňanská; Vladimír Vietoris; Oksana Sytar

    2013-01-01

    The main characteristics and classification of food additives, which are common in the food production, have been described in the present review. The ways of food additives classification, source of nature, main antioxidants, food colouring, flavours, flavor enhancers, bulking agents, stabilizers, sweeteners which were collected from literature based on structural and biochemical characteristics with description of source and possible effects on human, organisms and environment have been pre...

  2. SUNFLOWER HUSKS AS A SOURCE OF FUNCTIONAL FEED ADDITIVES

    OpenAIRE

    Khusid S. B.; Gneush A. N.; Nesterenko E. E.

    2015-01-01

    The article describes the results of the complex feed additive based on sunflower husk, enriched with beer wort with the addition of pumpkin pulp. We have studied the chemical composition of sunflower husk, which is the secondary resource of the processing plant raw material, selected methods of enrichment of this raw material with the help of fungi Trichoderma harzianum. Cellulolytic enzyme preparations on the basis of fungi of the genus Trichoderma for use in agriculture and animal feed pro...

  3. APPLIED RESEARCH ON NEW MULTI-FUNCTION GASOLINE ADDITIVE

    Institute of Scientific and Technical Information of China (English)

    CAI Ruibin; MING Caibing; GAO Zhiwen

    2006-01-01

    In order to assess the performance of a new cleansing and combustion-improving gasoline additive (MAZ), and to explore the evaluation methods of additives, two engines with the same model number and performance indices, fueled with and without the MAZ gasoline additive respectively, are carried through 100 h strenuous tests on a bench. The results obtained in full load characteristic and load characteristics of different operational modes are compared. It indicates that the power, economy and emission of the engine fueled with the MAZ additive all have obvious improvement in comparison with the engine without adding the additive: the power increasing by 16.43%, specific fuel consumption (SFC) decreasing 5.39%, and the emission of CO, HC and NOx falling by 28.61%, 54.38%and 10.1% respectively. Wear and tear of the engine cylinder is weakened, and sediment of combustion chamber inner side is reduced. In addition, no negative effect on the catalytic conversion device is found.

  4. SUNFLOWER HUSKS AS A SOURCE OF FUNCTIONAL FEED ADDITIVES

    Directory of Open Access Journals (Sweden)

    Khusid S. B.

    2015-03-01

    Full Text Available The article describes the results of the complex feed additive based on sunflower husk, enriched with beer wort with the addition of pumpkin pulp. We have studied the chemical composition of sunflower husk, which is the secondary resource of the processing plant raw material, selected methods of enrichment of this raw material with the help of fungi Trichoderma harzianum. Cellulolytic enzyme preparations on the basis of fungi of the genus Trichoderma for use in agriculture and animal feed production is often obtained when the surface method of cultivation. These drugs are cheap and contain a significant number of related hydrolytic enzymes, 29 such as amylase, protease, pectinase and hemicellulase, which are also important and valuable to the consumer. As a vitamin component of the feed additive we have selected a pumpkin pulp, which is a valuable feed for livestock and poultry is a source of carotene, fat and nitrogenous substances. We have also developed elements of technology for complex feed additive. We have created a comprehensive feed additive which can be used in the composition of diets in the feeding of farm animals and poultry

  5. Cognitive function in outbred house mice after 22 weeks of drinking oxygenated water.

    Science.gov (United States)

    Sommer, Angela M; Bogusch, Corinna; Lerchl, Alexander

    2007-05-16

    Oxygen-enriched drinking water, which is increasingly sold worldwide, is claimed to "keep both the body and the mind healthy." However, currently there is no scientific evidence for such a statement. Therefore, we assessed the effect of 22 weeks of drinking oxygenated water on cognitive performance in healthy mice, using a spatial learning task and behavioral observations. Thirty-six female mice (age 3 to 6 months) received either hyperoxic or normal tap water (approximately 6.6 vs. 1.8 microg O(2) g(-1) day(-1), respectively) throughout the study period. Mice were weighed one to two times per month, and a blood sample was taken from the tail to determine the hematocrit. In addition, red blood cells were counted microscopically one and two months after the start of the experiment. Four weeks after the last blood sample (21 weeks after the start of the experiment), exploration behavior and locomotor activity were observed on a holeboard, and learning ability tests were performed using an elevated open maze. No significant differences were seen between groups for any of the parameters investigated. Thus, the study does not support the hypothesis that drinking oxygenated water improves cognitive function or hematological parameters in mice.

  6. Cement Pastes and Mortars Containing Nitrogen-Doped and Oxygen-Functionalized Multiwalled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Mauricio Martínez-Alanis

    2016-01-01

    Full Text Available Cement pastes and mortars based on ordinary Portland cement containing nitrogen-doped multiwalled carbon nanotubes (MWCNT-Nx or oxygen-functionalized multiwalled carbon nanotubes (MWCNT-Ox are investigated. To incorporate MWCNTs into the cementitious matrix, the as-produced carpets are dispersed over periods of 1 and 2 hours in distilled water at pH levels of 1 and 7. The cement pastes are prepared by adding 0.1 wt% of MWCNTs to cement powder, followed by characterization with SEM and X-ray diffraction (XRD at an early age (first hours of hydration. The mortars are mechanically characterized during the hydration process for a period of 28 days. SEM characterization of cement pastes revealed that the carbon nanotubes are well incorporated in the cementitious matrix, with the hydrated cement grains interconnected by long carbon nanotubes. XRD characterizations demonstrated that, during the hydration of cement pastes, different peaks emerged that were associated with ettringite, hydrated calcium silicate, and calcium hydroxide, among other structures. Results of the compressive strength measurements for mortars simultaneously mixed with MWCNT-Nx and MWCNT-Ox reached an increment of approximately 30% in compressive strength. In addition, density functional theory calculations were performed in nitrogen-doped and oxygen-functionalized carbon nanotubes interacting with a cement grain.

  7. Atom interaction propensities of oxygenated chemical functions in crystal packings

    Directory of Open Access Journals (Sweden)

    Christian Jelsch

    2017-03-01

    Full Text Available The crystal contacts of several families of hydrocarbon compounds substituted with one or several types of oxygenated chemical groups were analyzed statistically using the Hirshfeld surface methodology. The propensity of contacts to occur between two chemical types is described with the contact enrichment descriptor. The systematic large enrichment ratios of some interactions like the O—H...O hydrogen bonds suggests that these contacts are a driving force in the crystal packing formation. The same statement holds for the weaker C—H...O hydrogen bonds in ethers, esters and ketones, in the absence of polar H atoms. The over-represented contacts in crystals of oxygenated hydrocarbons are generally of two types: electrostatic attractions (hydrogen bonds and hydrophobic interactions. While Cl...O interactions are generally avoided, in a minority of chloro-oxygenated hydrocarbons, significant halogen bonding does occur. General tendencies can often be derived for many contact types, but outlier compounds are instructive as they display peculiar or rare features. The methodology also allows the detection of outliers which can be structures with errors. For instance, a significant number of hydroxylated molecules displaying over-represented non-favorable oxygen–oxygen contacts turned out to have wrongly oriented hydroxyl groups. Beyond crystal packings with a single molecule in the asymmetric unit, the behavior of water in monohydrate compounds and of crystals with Z′ = 2 (dimers are also investigated. It was found in several cases that, in the presence of several oxygenated chemical groups, cross-interactions between different chemical groups (e.g. water/alcohols; alcohols/phenols are often favored in the crystal packings. While some trends in accordance with common chemical principles are retrieved, some unexpected results can however appear. For example, in crystals of alcohol–phenol compounds, the strong O—H...O hydrogen bonds between

  8. Dietary nitrate does not reduce oxygen cost of exercise or improve muscle mitochondrial function in mitochondrial myopathy patients.

    Science.gov (United States)

    Nabben, Miranda; Schmitz, Joep P J; Ciapaite, Jolita; Le Clercq, Carlijn M P; van Riel, Natal A; Haak, Harm R; Nicolay, Klaas; de Coo, Irenaeus F; Smeets, Hubert J M; Praet, Stephan F; van Loon, Luc J C; Prompers, Jeanine J

    2017-02-08

    Muscle weakness and exercise intolerance negatively affect the quality of life of mitochondrial myopathy patients. Short-term dietary nitrate supplementation has been shown to improve exercise performance and reduce oxygen cost of exercise in healthy humans and trained athletes. We investigated if 1 week of dietary inorganic nitrate supplementation decreases the oxygen cost of exercise and improves mitochondrial function in mitochondrial myopathy patients. Ten mitochondrial myopathy patients (40 ± 5 years, maximal whole-body oxygen uptake = 21.2 ± 3.2 mL/min/kg body weight, maximal workload = 122 ± 26 W) received 8.5 mg/kg body weight/day of inorganic nitrate (~7 mmol) for 8 days. Whole-body oxygen consumption at 50% of the maximal workload, in vivo skeletal muscle oxidative capacity (evaluated from post-exercise phosphocreatine recovery using (31)P magnetic resonance spectroscopy) and ex vivo mitochondrial oxidative capacity in permeabilized skinned muscle fibers (measured with high-resolution respirometry) were determined before and after nitrate supplementation. Despite a 6-fold increase in plasma nitrate levels, nitrate supplementation did not affect whole-body oxygen cost during submaximal exercise. Additionally, no beneficial effects of nitrate were found on in vivo or ex vivo muscle mitochondrial oxidative capacity. This is the first time that the therapeutic potential of dietary nitrate for mitochondrial myopathy patients was evaluated. We conclude that 1 week of dietary nitrate supplementation does not reduce oxygen cost of exercise or improve mitochondrial function in the group of patients tested.

  9. Oxygen Therapy

    Science.gov (United States)

    Oxygen therapy is a treatment that provides you with extra oxygen. Oxygen is a gas that your body needs to function. Normally, your lungs absorb oxygen from the air you breathe. But some conditions ...

  10. Additional developments regarding manifest dream structure and function.

    Science.gov (United States)

    Wolowitz, H

    1998-06-01

    Detailed observation of manifest dream sequences indicated self-advocating occurrences facilitating the dreamer's self interests, opposed by self-adversarial interferences. Further examination of manifest dream syntactical structure additionally suggested a recurrent, four-step, algorithm for personal problem-solving within an interpersonal matrix consisting of the following cycle: (1) an opening scene setting the stage, (2) for the emergence of a self-concern, (3) which evokes a strategy to deal with dreamer's self-concern, (4) that eventuates in a consequence of the strategy. These steps repeat until the dream ends. Observing these manifest dream structural features, attributable to broadening past theorizing with "bottom-up" approaches, clarifies the dream's problem-solving process by providing an empirical, observable framework for dream interpretation and by contributing to their consensual validation.

  11. Variations in alveolar partial pressure for carbon dioxide and oxygen have additive not synergistic acute effects on human pulmonary vasoconstriction.

    Directory of Open Access Journals (Sweden)

    Quentin P P Croft

    Full Text Available The human pulmonary vasculature constricts in response to hypercapnia and hypoxia, with important consequences for homeostasis and adaptation. One function of these responses is to direct blood flow away from poorly-ventilated regions of the lung. In humans it is not known whether the stimuli of hypercapnia and hypoxia constrict the pulmonary blood vessels independently of each other or whether they act synergistically, such that the combination of hypercapnia and hypoxia is more effective than the sum of the responses to each stimulus on its own. We independently controlled the alveolar partial pressures of carbon dioxide (Paco 2 and oxygen (Pao 2 to examine their possible interaction on human pulmonary vasoconstriction. Nine volunteers each experienced sixteen possible combinations of four levels of Paco 2 (+6, +1, -4 and -9 mmHg, relative to baseline with four levels of Pao 2 (175, 100, 75 and 50 mmHg. During each of these sixteen protocols Doppler echocardiography was used to evaluate cardiac output and systolic tricuspid pressure gradient, an index of pulmonary vasoconstriction. The degree of constriction varied linearly with both Paco 2 and the calculated haemoglobin oxygen desaturation (1-So2. Mixed effects modelling delivered coefficients defining the interdependence of cardiac output, systolic tricuspid pressure gradient, ventilation, Paco 2 and So2. No interaction was observed in the effects on pulmonary vasoconstriction of carbon dioxide and oxygen (p>0.64. Direct effects of the alveolar gases on systolic tricuspid pressure gradient greatly exceeded indirect effects arising from concurrent changes in cardiac output.

  12. Extracts of medicinal plants as functional beer additives

    Directory of Open Access Journals (Sweden)

    Đorđević Sofija

    2016-01-01

    Full Text Available This paper is based on determining the level of the antioxidant activity of beer, to which sensory acceptable amounts of selected extracts of medicinal plants were added, with the aim of obtaining a beer with increased functional and new sensory features. For purposes of this study a commercial lager beer type Pils and extracts of herbal drugs: Melissae folium, Thymi herba, Juniperi fructus, Urticae radix and Lupuli strobuli, were used. Total phenols were analyzed by the method of Folin-Ciocalteu, and the antioxidant activity of samples using FRAP and DPPH test. Sensory evaluation of beer was conducted on 80 subjects, using a nine levels hedonic scale. The results showed that the content of total phenols was the highest in the beer which thyme, juniper and lemon balm were added to (384.22, 365.38 and 363.08 mg GAE/L, respectively, representing the increase of 37.09, 30.36 and 29.55% (respectively compared to the commercial lager beer. Values of antioxidant activity were correlated with the content of total phenols. The extract of lemon balm blended in the best manner with the baseline, commercial lager beer in terms of sensory acceptability. New beer, enriched with lemon balm, had a pleasant, appealing and harmonious flavor and aroma.

  13. Additional functions of remotely read kWh-meters

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, P. [VTT Energy, Espoo (Finland); Vehvilaeinen, S. [Mittrix Oy (Finland); Rantanen, J. [Helsinki Energy Board, Helsinki (Finland)

    1996-12-31

    In this presentation the possibilities to include new applications into remotely read smart kWh-meters are considered. New electronic meters can measure various electric quantities and have some extra calculating capacity. So they can be used to provide functions that distribution automation and the customer need and thus share the costs. Some applications like monitoring the state of the distribution network or locating faults are only for the utility, but many applications also need an interface to the customer or his automation system. Among those are monitoring the quality of electricity, estimating load curves, applying dynamic tariffs and selling electricity and accounting. As a special item, the continuous monitoring of the quality of electricity is discussed. This includes voltage levels, total distortion, asymmetry and so on. If such a kWh-meter indicates quality problems the situation can be detected with a suitable portable quality meter. The poor quality can be detected before it causes harm to equipment owned by the customers or the power distribution company. This presentation also presents a prototype of such a quality monitoring kWh-meter

  14. Additive Manufacturing of Functional Elements on Sheet Metal

    Science.gov (United States)

    Schaub, Adam; Ahuja, Bhrigu; Butzhammer, Lorenz; Osterziel, Johannes; Schmidt, Michael; Merklein, Marion

    Laser Beam Melting (LBM) process with its advantages of high design flexibility and free form manufacturing methodology is often applied limitedly due to its low productivity and unsuitability for mass production compared to conventional manufacturing processes. In order to overcome these limitations, a hybrid manufacturing methodology is developed combining the additive manufacturing process of laser beam melting with sheet forming processes. With an interest towards aerospace and medical industry, the material in focus is Ti-6Al-4V. Although Ti-6Al-4V is a commercially established material and its application for LBM process has been extensively investigated, the combination of LBM of Ti-6Al-4V with sheet metal still needs to be researched. Process dynamics such as high temperature gradients and thermally induced stresses lead to complex stress states at the interaction zone between the sheet and LBM structure. Within the presented paper mechanical characterization of hybrid parts will be performed by shear testing. The association of shear strength with process parameters is further investigated by analyzing the internal structure of the hybrid geometry at varying energy inputs during the LBM process. In order to compare the hybrid manufacturing methodology with conventional fabrication, the conventional methodologies subtractive machining and state of the art Laser Beam Melting is evaluated within this work. These processes will be analyzed for their mechanical characteristics and productivity by determining the build time and raw material consumption for each case. The paper is concluded by presenting the characteristics of the hybrid manufacturing methodology compared to alternative manufacturing technologies.

  15. Thermochemical properties, rotation barriers, and group additivity for unsaturated oxygenated hydrocarbons and radicals resulting from reaction of vinyl and phenyl radical systems with O2.

    Science.gov (United States)

    Sebbarand, Nadia; Bockhorn, Henning; Bozzelli, Joseph W

    2005-03-17

    Oxidation of unsaturated and aromatic hydrocarbons in atmospheric and combustion processes results in formation of linear and cyclic unsaturated, oxygenated-hydrocarbon intermediates. The thermochemical parameters delatafH degrees 298, S degrees 298, and C(p)(f298)(T) for these intermediates are needed to understand their stability and reaction paths in further oxidation. These properties are not available for a majority of these unsaturated oxy-hydrocarbons and their corresponding radicals, even via group additivity methods. Enthalpy, entropy, and heat capacity of a series of 40 oxygenated and non-oxygenated molecules, or radicals corresponding to hydrogen atom loss from the parent stable molecules are determined in this study. Enthalpy (delatafH degrees 298 in kcal mol(-1)) is derived from the density function calculations at the B3LYP/6-311g(d,p) calculated enthalpy of reaction (delatafH degrees rxn,298) and by use of isodesmic (work) reactions. Estimation of error in enthalpy delatafH degrees 298, from use of computational chemistry coupled with work reactions analysis, is presented using comparisons between the calculated and literature enthalpies of reaction. Entropies (S degrees 298) and heat capacities (C(p)(f298)(T)) were calculated using the B3LYP/6-311G(d,p) determined frequencies and geometries. Potential barriers for internal rotors in each molecule were determined and used (in place of torsion frequencies) to calculate contributions to S and C(p)(T) from the hindered rotors. Twenty-six groups for use in group additivity (GA) are also developed.

  16. Oxygen sensing and signaling.

    Science.gov (United States)

    van Dongen, Joost T; Licausi, Francesco

    2015-01-01

    Oxygen is an indispensable substrate for many biochemical reactions in plants, including energy metabolism (respiration). Despite its importance, plants lack an active transport mechanism to distribute oxygen to all cells. Therefore, steep oxygen gradients occur within most plant tissues, which can be exacerbated by environmental perturbations that further reduce oxygen availability. Plants possess various responses to cope with spatial and temporal variations in oxygen availability, many of which involve metabolic adaptations to deal with energy crises induced by low oxygen. Responses are induced gradually when oxygen concentrations decrease and are rapidly reversed upon reoxygenation. A direct effect of the oxygen level can be observed in the stability, and thus activity, of various transcription factors that control the expression of hypoxia-induced genes. Additional signaling pathways are activated by the impact of oxygen deficiency on mitochondrial and chloroplast functioning. Here, we describe the molecular components of the oxygen-sensing pathway.

  17. Stability of a Bi-Additive Functional Equation in Banach Modules Over a C⋆-Algebra

    Directory of Open Access Journals (Sweden)

    Won-Gil Park

    2012-01-01

    Full Text Available We solve the bi-additive functional equation f(x+y,z−w+f(x−y,z+w=2f(x,z−2f(y,w and prove that every bi-additive Borel function is bilinear. And we investigate the stability of a bi-additive functional equation in Banach modules over a unital C⋆-algebra.

  18. Diabetes and the impairment of reproductive function: possible role of mitochondria and reactive oxygen species.

    Science.gov (United States)

    Amaral, Sandra; Oliveira, Paulo J; Ramalho-Santos, João

    2008-02-01

    Diabetes Mellitus (DM), a state of chronic hyperglycemia, is a major cause of serious micro and macrovascular diseases, affecting, therefore, nearly every system in the body. Growing evidence indicates that oxidative stress is increased in diabetes due to overproduction of reactive oxygen species (ROS) and decreased efficiency of antioxidant defences, a process that starts very early and worsens over the course of the disease. During the development of diabetes, oxidation of lipids, proteins and DNA increase with time. Mitochondrial DNA mutations have also been reported in diabetic tissues, suggesting oxidative stress-related mitochondrial damage. Diabetes-related oxidative stress may also be the trigger for many alterations on sexual function, which can also include decreased testicular mitochondrial function. Although sexual disorders have been extensively studied in diabetic men, possible changes in the sexual function of diabetic women have only recently received attention. The prevalence of sexual dysfunction in diabetic men approaches 50%, whereas in diabetic women it seems to be slightly lower. Testicular dysfunction, impotence, decreased fertility potential and retrograde ejaculations are conditions that have been described in diabetic males. Diabetes is also the most common cause of erectile dysfunction in men. Poor semen quality has also been reported in diabetic men, including decreased sperm motility and concentration, abnormal morphology and increased seminal plasma abnormalities. In addition, diabetic men may have decreased serum testosterone due to impaired Leydig cell function. Among diabetic women neuropathy, vascular impairment and psychological complaints have been implicated in the pathogenesis of decreased libido, low arousability, decreased vaginal lubrication, orgasmic dysfunction, and dyspareunia. An association between the production of excess radical oxygen species and disturbed embryogenesis in diabetic pregnancies has also been suggested

  19. Prospective longitudinal evaluation of lung function during the first year of life after extracorporeal membrane oxygenation

    NARCIS (Netherlands)

    Hofhuis, W.; Hanekamp, M.N.; Ijsselstijn, H.; Nieuwhof, E.M.; Hop, W.C.J.; Tibboel, D.; Jongste, J.C. de; Merkus, P.J.F.M.

    2011-01-01

    OBJECTIVE: To collect longitudinal data on lung function in the first year of life after extracorporeal membrane oxygenation and to evaluate relationships between lung function and perinatal factors. Longitudinal data on lung function in the first year of life after extracorporeal membrane oxygenati

  20. Role of renal oxygenation and mitochondrial function in the pathophysiology of acute kidney injury.

    Science.gov (United States)

    Nourbakhsh, Noureddin; Singh, Prabhleen

    2014-01-01

    There are unique features of renal oxygenation that render the kidney susceptible to oxygen demand-supply mismatch and hypoxia. Renal oxygen consumption by oxidative metabolism is closely coupled to and driven by tubular transport, which is linked to the filtered solute load and glomerular filtration rate (GFR). In turn, filtered solute load and GFR are dependent on the renal blood flow. Hence, changes in renal blood flow increase oxygen delivery but also increase oxygen demand (consumption) simultaneously by increasing the tubular workload of solute transport. The renal blood flow to different regions of kidney is also inhomogeneous, increasing the oxygen demand-supply mismatch in particular areas such as the outer medulla which become more susceptible to injury. Thus, tubular transport and oxidative metabolism by miochondria are closely coupled in the kidney and are the principal determinants of intrarenal oxygenation. Here we review the published literature characterizing renal oxygenation and mitochondrial function in ischemic and sepsis-associated acute kidney injury (AKI). However, the coupling of transport and metabolism in AKI has not been examined. This is a potentially fruitful area of research that should become increasingly active given the emerging data linking renal oxygenation and hypoxia to acute and chronic dysfunction in the kidney. 2014 S. Karger AG, Basel.

  1. Low oxygen alters mitochondrial function and response to oxidative stress in human neural progenitor cells

    Directory of Open Access Journals (Sweden)

    Yury M. Lages

    2015-12-01

    Full Text Available Oxygen concentration should be carefully regulated in all living tissues, beginning at the early embryonic stages. Unbalances in oxygen regulation can lead to cell death and disease. However, to date, few studies have investigated the consequences of variations in oxygen levels for fetal-like cells. Therefore, in the present work, human neural progenitor cells (NPCs derived from pluripotent stem cells grown in 3% oxygen (v/v were compared with NPCs cultured in 21% (v/v oxygen. Low oxygen concentrations altered the mitochondrial content and oxidative functions of the cells, which led to improved ATP production, while reducing generation of reactive oxygen species (ROS. NPCs cultured in both conditions showed no differences in proliferation and glucose metabolism. Furthermore, antioxidant enzymatic activity was not altered in NPCs cultured in 3% oxygen under normal conditions, however, when exposed to external agents known to induce oxidative stress, greater susceptibility to DNA damage was observed. Our findings indicate that the management of oxygen levels should be considered for in vitro models of neuronal development and drug screening.

  2. Acidosis overrides oxygen deprivation to maintain mitochondrial function and cell survival

    Science.gov (United States)

    Khacho, Mireille; Tarabay, Michelle; Patten, David; Khacho, Pamela; MacLaurin, Jason G.; Guadagno, Jennifer; Bergeron, Richard; Cregan, Sean P.; Harper, Mary-Ellen; Park, David S.; Slack, Ruth S.

    2014-01-01

    Sustained cellular function and viability of high-energy demanding post-mitotic cells rely on the continuous supply of ATP. The utilization of mitochondrial oxidative phosphorylation for efficient ATP generation is a function of oxygen levels. As such, oxygen deprivation, in physiological or pathological settings, has profound effects on cell metabolism and survival. Here we show that mild extracellular acidosis, a physiological consequence of anaerobic metabolism, can reprogramme the mitochondrial metabolic pathway to preserve efficient ATP production regardless of oxygen levels. Acidosis initiates a rapid and reversible homeostatic programme that restructures mitochondria, by regulating mitochondrial dynamics and cristae architecture, to reconfigure mitochondrial efficiency, maintain mitochondrial function and cell survival. Preventing mitochondrial remodelling results in mitochondrial dysfunction, fragmentation and cell death. Our findings challenge the notion that oxygen availability is a key limiting factor in oxidative metabolism and brings forth the concept that mitochondrial morphology can dictate the bioenergetic status of post-mitotic cells. PMID:24686499

  3. Density Functional Theory Study on the Addition Reactions of 4-methyl-benzaldoximes with Propene

    Institute of Scientific and Technical Information of China (English)

    张健; 马金广

    2009-01-01

    The Michael addition reactions of Z and E 4-methyl-benzaldoximes with propene were investigated theoretically by DFT method at B3LYP/6-31G* level. The calculation results show that both addition reactions are concerted processes accompanied by the migration of hydrogen from the atom oxygen to carbon. Both products Z and E nitrones have dipolar charge distributions and activities. Z isomer is more favorable in the reaction due to the barrier is lower.

  4. Effects of Oxygen-Containing Functional Groups on Supercapacitor Performance

    Energy Technology Data Exchange (ETDEWEB)

    Kerisit, Sebastien N.; Schwenzer, Birgit; Vijayakumar, M.

    2014-07-03

    Molecular dynamics (MD) simulations of the interface between graphene and the ionic liquid 1-butyl-3-methylimidazolium trifluoromethanesulfonate (BMIM OTf) were carried out to gain molecular-level insights into the performance of graphene-based supercapacitors and, in particular, determine the effects of the presence of oxygen-containing defects at the graphene surface on their integral capacitance. The MD simulations predict that increasing the surface coverage of hydroxyl groups negatively affects the integral capacitance, whereas the effect of the presence of epoxy groups is much less significant. The calculated variations in capacitance are found to be directly correlated to the interfacial structure. Indeed, hydrogen bonding between hydroxyl groups and SO3 anion moieties prevents BMIM+ and OTf- molecules from interacting favorably in the dense interfacial layer and restrains the orientation and mobility of OTf- ions, thereby reducing the permittivity of the ionic liquid at the interface. The results of the molecular simulations can facilitate the rational design of electrode materials for supercapacitors.

  5. Oxygen reduction on a Pt(111) catalyst in HT-PEM fuel cells by density functional theory

    Science.gov (United States)

    Sun, Hong; Li, Jie; Almheiri, Saif; Xiao, Jianyu

    2017-08-01

    The oxygen reduction reaction plays an important role in the performance of high-temperature proton exchange membrane (HT-PEM) fuel cells. In this study, a molecular dynamics model, which is based on the density functional theory and couples the system's energy, the exchange-correlation energy functional, the charge density distribution function, and the simplified Kohn-Sham equation, was developed to simulate the oxygen reduction reaction on a Pt(111) surface. Additionally, an electrochemical reaction system on the basis of a four-electron reaction mechanism was also developed for this simulation. The reaction path of the oxygen reduction reaction, the product structure of each reaction step and the system's energy were simulated. It is found that the first step reaction of the first hydrogen ion with the oxygen molecule is the controlling step of the overall reaction. Increasing the operating temperature speeds up the first step reaction rate and slightly decreases its reaction energy barrier. Our results provide insight into the working principles of HT-PEM fuel cells.

  6. Oxygen reduction on a Pt(111 catalyst in HT-PEM fuel cells by density functional theory

    Directory of Open Access Journals (Sweden)

    Hong Sun

    2017-08-01

    Full Text Available The oxygen reduction reaction plays an important role in the performance of high-temperature proton exchange membrane (HT-PEM fuel cells. In this study, a molecular dynamics model, which is based on the density functional theory and couples the system’s energy, the exchange-correlation energy functional, the charge density distribution function, and the simplified Kohn–Sham equation, was developed to simulate the oxygen reduction reaction on a Pt(111 surface. Additionally, an electrochemical reaction system on the basis of a four-electron reaction mechanism was also developed for this simulation. The reaction path of the oxygen reduction reaction, the product structure of each reaction step and the system’s energy were simulated. It is found that the first step reaction of the first hydrogen ion with the oxygen molecule is the controlling step of the overall reaction. Increasing the operating temperature speeds up the first step reaction rate and slightly decreases its reaction energy barrier. Our results provide insight into the working principles of HT-PEM fuel cells.

  7. Blood oxygen-level dependent functional assessment of cerebrovascular reactivity: Feasibility for intraoperative 3 Tesla MRI.

    Science.gov (United States)

    Fierstra, Jorn; Burkhardt, Jan-Karl; van Niftrik, Christiaan Hendrik Bas; Piccirelli, Marco; Pangalu, Athina; Kocian, Roman; Neidert, Marian Christoph; Valavanis, Antonios; Regli, Luca; Bozinov, Oliver

    2017-02-01

    To assess the feasibility of functional blood oxygen-level dependent (BOLD) MRI to evaluate intraoperative cerebrovascular reactivity (CVR) at 3 Tesla field strength. Ten consecutive neurosurgical subjects scheduled for a clinical intraoperative MRI examination were enrolled in this study. In addition to the clinical protocol a BOLD sequence was implemented with three cycles of 44 s apnea to calculate CVR values on a voxel-by-voxel basis throughout the brain. The CVR range was then color-coded and superimposed on an anatomical volume to create high spatial resolution CVR maps. Ten subjects (mean age 34.8 ± 13.4; 2 females) uneventfully underwent the intraoperative BOLD protocol, with no complications occurring. Whole-brain CVR for all subjects was (mean ± SD) 0.69 ± 0.42, whereas CVR was markedly higher for tumor subjects as compared to vascular subjects, 0.81 ± 0.44 versus 0.33 ± 0.10, respectively. Furthermore, color-coded functional maps could be robustly interpreted for a whole-brain assessment of CVR. We demonstrate that intraoperative BOLD MRI is feasible in creating functional maps to assess cerebrovascular reactivity throughout the brain in subjects undergoing a neurosurgical procedure. Magn Reson Med 77:806-813, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  8. Study on the effect of hydrogen addition on the variation of plasma parameters of argon-oxygen magnetron glow discharge for synthesis of TiO2 films

    Directory of Open Access Journals (Sweden)

    Partha Saikia

    2016-04-01

    Full Text Available We report the effect of hydrogen addition on plasma parameters of argon-oxygen magnetron glow discharge plasma in the synthesis of H-doped TiO2 films. The parameters of the hydrogen-added Ar/O2 plasma influence the properties and the structural phases of the deposited TiO2 film. Therefore, the variation of plasma parameters such as electron temperature (Te, electron density (ne, ion density (ni, degree of ionization of Ar and degree of dissociation of H2 as a function of hydrogen content in the discharge is studied. Langmuir probe and Optical emission spectroscopy are used to characterize the plasma. On the basis of the different reactions in the gas phase of the magnetron discharge, the variation of plasma parameters and sputtering rate are explained. It is observed that the electron and heavy ion density decline with gradual addition of hydrogen in the discharge. Hydrogen addition significantly changes the degree of ionization of Ar which influences the structural phases of the TiO2 film.

  9. Functional neuroanatomy in depressed patients with sexual dysfunction: blood oxygenation level dependent functional MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jong Chul [Chonnam National Univ. Hospital, Kwangju (Korea, Republic of)

    2004-06-15

    To demonstrate the functional neuroanatomy associated with sexual arousal visually evoked in depressed males who have underlying sexual dysfunction using Blood Oxygenation Level Dependent-based fMRI. Ten healthy volunteers (age range 21-55: mean 32.5 years), and 10 depressed subjects (age range 23-51: mean 34.4 years, mean Beck Depression Inventory score of 39.6 {+-} 5.9, mean Hamilton Rating Scale Depression (HAMD)-17 score of 33.5 {+-} 6.0) with sexual arousal dysfunction viewed erotic and neutral video films during functional magnetic resonance imaging (fMRI) with 1.5 T MR scanner (GE Signa Horizon). The fMRI data were obtained from 7 oblique planes using gradient-echo EPI (flip angle/TR/TE=90 .deg. /6000 ms/50 ms). The visual stimulation paradigm began with 60 sec of black screen, 150 sec of neutral stimulation with a documentary video film, 30 sec of black screen, 150 sec of sexual stimulation with an erotic video film followed by 30 sec of black screen. The brain activation maps and their quantification were analyzed by SPM99 program. There was a significant difference of brain activation between two groups during visual sexual stimulation. In depressed subjects, the level of activation during the visually evoked sexual arousal was significantly less than that of healthy volunteers, especially in the cerebrocortical areas of the hypothalamus, thalamus, caudate nucleus, and inferior and superior temporal gyri. On the other hand, the cerebral activation patterns during the neutral condition in both groups showed no significant differences ({rho} < 0.01). This study is the first demonstration of the functional neuroanatomy of the brain associated with sexual dysfunction in depressed patients using fMRI. In order to validate our physiological neuroscience results, further studies that would include patients with other disorders and sexual dysfunction, and depressed patients without sexual dysfunction and their treatment response are needed.

  10. A new strategy for integrating abundant oxygen functional groups into carbon felt electrode for vanadium redox flow batteries

    Science.gov (United States)

    Kim, Ki Jae; Lee, Seung-Wook; Yim, Taeeun; Kim, Jae-Geun; Choi, Jang Wook; Kim, Jung Ho; Park, Min-Sik; Kim, Young-Jun

    2014-11-01

    The effects of surface treatment combining corona discharge and hydrogen peroxide (H2O2) on the electrochemical performance of carbon felt electrodes for vanadium redox flow batteries (VRFBs) have been thoroughly investigated. A high concentration of oxygen functional groups has been successfully introduced onto the surface of the carbon felt electrodes by a specially designed surface treatment, which is mainly responsible for improving the energy efficiency of VRFBs. In addition, the wettability of the carbon felt electrodes also can be significantly improved. The energy efficiency of the VRFB cell employing the surface modified carbon felt electrodes is improved by 7% at high current density (148 mA cm-2). Such improvement is attributed to the faster charge transfer and better wettability allowed by surface-active oxygen functional groups. Moreover, this method is much more competitive than other surface treatments in terms of processing time, production costs, and electrochemical performance.

  11. The functioning of oxygen concentrators in resource-limited settings: a situation assessment in two countries.

    Science.gov (United States)

    La Vincente, S F; Peel, D; Carai, S; Weber, M W; Enarson, P; Maganga, E; Soyolgerel, G; Duke, T

    2011-05-01

    The paediatric wards of hospitals in Malawi and Mongolia. To describe oxygen concentrator functioning in two countries with widespread, long-term use of concentrators as a primary source of oxygen for treating children. A systematic assessment of concentrators in the paediatric wards of 15 hospitals in Malawi and nine hospitals in Mongolia. Oxygen concentrators had been installed for a median of 48 months (interquartile range [IQR] 6-60) and 36 months (IQR 12-96), respectively, prior to the evaluation in Malawi and Mongolia. Concentrators were the primary source of oxygen. Three quarters of the concentrators assessed in Malawi (28/36) and half those assessed in Mongolia (13/25) were functional. Concentrators were found to remain functional with up to 30 000 h of use. However, several concentrators were functioning very poorly despite limited use. Concentrators from a number of different manufacturers were evaluated, and there was marked variation in performance between brands. Inadequate resources for maintenance were reported in both countries. Years after installation of oxygen concentrators, many machines were still functioning, indicating that widespread use can be sustained in resource-limited settings. However, concentrator performance varied substantially. Procurement of high-quality and appropriate equipment is critical, and resources should be made available for ongoing maintenance.

  12. Functional link between ETB receptors and eNOS maintain tissue oxygenation in the normal liver.

    Science.gov (United States)

    Paxian, Markus; Keller, Steve A; Baveja, Rajiv; Korneszczuk, Katarzyna; Huynh, Toan T; Clemens, Mark G

    2004-01-01

    Endothelins and their receptors play a crucial role in regulating liver microcirculation in pathophysiological conditions. The authors investigated the functional significance of the coupling of ET(B) receptors and eNOS in maintaining regional perfusion and tissue oxygenation in the normal liver. The effect of endothelin-1 or the ET(B) agonist IRL1620 on oxygen consumption was determined in isolated perfused liver and isolated hepatocytes. Oxygen delivery to the liver tissue was determined in vivo. Following eNOS or iNOS blockade, either ET-1 or IRL1620 was infused via the portal vein. Hepatic tissue oxygenation, redox state, and microcirculation were investigated by intravital microscopy. Injury was estimated by serum LDH. Although IRL1620 and endothelin-1 increased oxygen consumption in isolated hepatocytes, in intact liver, endothelin decreased oxygen consumption while IRL1620 produced no change. In vivo, ET(B) stimulation modestly altered hepatic tissue P(O(2)), redox potential, and microcirculation. eNOS inhibition and ET(B) activation dramatically reduced microcirculatory blood flow, oxygen supply, and increased LDH release. Inhibition of iNOS resulted in small but not significant changes in these parameters. Concomitant ET(A)/ET(B) receptor activation increased microcirculatory failure and decreased tissue oxygen even without NOS inhibition. In contrast, hepatocellular injury was significantly increased following eNOS inhibition. Coupling between ET(B) receptor stimulation and eNOS activation decreases sinusoidal constriction and plays a functionally important role in maintaining microcirculation and tissue oxygenation in the normal liver.

  13. Effects of oxygen addition in reactive cluster beam deposition of tungsten by magnetron sputtering with gas aggregation

    Energy Technology Data Exchange (ETDEWEB)

    Polášek, J., E-mail: xpolasekj@seznam.cz [Department of Surface and Plasma Science, Faculty of Mathematics and Physic, Charles University, V Holešovičkách 2, Prague 8, CZ-18000 (Czech Republic); Mašek, K. [Department of Surface and Plasma Science, Faculty of Mathematics and Physic, Charles University, V Holešovičkách 2, Prague 8, CZ-18000 (Czech Republic); Marek, A.; Vyskočil, J. [HVM Plasma Ltd., Na Hutmance 2, Prague 5, CZ-158 00 (Czech Republic)

    2015-09-30

    In this work, we investigated the possibilities of tungsten and tungsten oxide nanoclusters generation by means of non-reactive and reactive magnetron sputtering with gas aggregation. It was found that in pure argon atmosphere, cluster aggregation proceeded in two regimes depending on argon pressure in the aggregation chamber. At the lower pressure, cluster generation was dominated by two-body collisions yielding larger clusters (about 5.5 nm in diameter) at lower rate. At higher pressures, cluster generation was dominated by three-body collisions yielding smaller clusters (3–4 nm in diameter) at higher rate. The small amount of oxygen admixture in the aggregation chamber had considerable influence on cluster aggregation process. At certain critical pressure, the presence of oxygen led to the raise of deposition rate and cluster size. Resulting clusters were composed mostly of tungsten trioxide. The oxygen pressure higher than critical led to the target poisoning and the decrease in the sputtering rate. Critical oxygen pressure decreased with increasing argon pressure, suggesting that cluster aggregation process was influenced by atomic oxygen species (namely, O{sup −} ion) generated by oxygen–argon collisions in the magnetron plasma. - Highlights: • Formation of tungsten and tungsten oxide clusters was observed. • Two modes of cluster aggregation in pure argon atmosphere were found. • Dependence of cluster deposition speed and size on oxygen admixture was observed. • Changes of dependence on oxygen with changing argon pressure were described.

  14. The investigation of effect of organic carbon sources addition in anaerobic-aerobic (low dissolved oxygen) sequencing batch reactor for nutrients removal from wastewaters.

    Science.gov (United States)

    Zheng, Xiong; Tong, Juan; Li, Hongjing; Chen, Yinguang

    2009-05-01

    The effect of addition of organic carbon sources (acetic acid and waste activated sludge alkaline fermentation liquid) on anaerobic-aerobic (low dissolved oxygen, 0.15-0.45 mg/L) biological municipal wastewater treatment was investigated. The results showed that carbon source addition affected not only the transformations of polyhydroxyalkanoates (PHA), glycogen, nitrogen and phosphorus, but the net removal of nitrogen and phosphorus. The removal efficiencies of TN and TP were, respectively, 61% and 61% without organic carbon source addition, 81% and 95% with acetic acid addition, and 83% and 97% with waste activated sludge alkaline fermentation liquid addition. It seems that the alkaline fermentation liquid of waste biosolids generated in biological wastewater treatment plant can be used to replace acetic acid as an additional carbon source to improve the anaerobic-aerobic (low dissolved oxygen) municipal wastewater nutrients removal although its use was observed to cause a slight increase of effluent BOD and COD concentrations.

  15. Examination of Perovskite Structure CaMnO3-δ with MgO Addition as Oxygen Carrier for Chemical Looping with Oxygen Uncoupling Using Methane and Syngas

    Directory of Open Access Journals (Sweden)

    Dazheng Jing

    2013-01-01

    Full Text Available Perovskite structure oxygen carriers with the general formula CaMnxMg1-xO3-δ were spray-dried and examined in a batch fluidized bed reactor. The CLOU behavior, reactivity towards methane, and syngas were investigated at temperature 900°C to 1050°C. All particles showed CLOU behavior at these temperatures. For experiments with methane, a bed mass corresponding to 57 kg/MW was used in the reactor, and the average CH4 to CO2 conversion was above 97% for most materials. Full syngas conversion was achieved for all materials utilizing a bed mass corresponding to 178 kg/MW. SEM/EDX and XRD confirmed the presence of MgO in the fresh and used samples, indicating that the Mg cation is not incorporated into the perovskite structure and the active compound is likely pure CaMnO3-δ. The very high reactivity with fuel gases, comparable to that of baseline oxygen carriers of NiO, makes these perovskite particles highly interesting for commercial CLC application. Contrary to NiO, oxygen carriers based on CaMnO3-δ have no thermodynamic limitations for methane oxidation to CO2 and H2O, not to mention that the materials are environmentally friendly and can utilize much cheaper raw materials for production. The physical properties, crystalline phases, and morphology information were also determined in this work.

  16. Oxygen functionalization of MWCNTs in RF-dielectric barrier discharge Ar/O2 plasma

    Science.gov (United States)

    Abdel-Fattah, E.; Ogawa, D.; Nakamura, K.

    2017-07-01

    The oxygenation of multi-wall carbon nanotubes (MWCNTs) was performed via a radio frequency dielectric barrier discharge (RF-DBD) in an Ar/{{\\text{H}}2}\\text{O} plasma mixture. The relative intensity of the Ar/{{\\text{O}}2} plasma species was characterized by optical emission spectroscopy (OES). The effects of treatment time, RF power and oxygen gas percentage on the chemical composition and surface morphology of MWCNTs were investigated by means of x-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and field emission scanning electron microscopy (FE-SEM). The results of FTIR and XPS revealed the presence of oxygen-containing functional groups on the MWCNTs treated in an Ar/{{\\text{O}}2} plasma at an RF power of 50 W and pressure of 400 Pa. The amount of oxygen functional groups (C=O, C-O, and O-COO) also increased by increasing treatment time up to 6 min, but slightly decreased when treatment time was increased by 10 min. The increase of oxygen gas percentage in the plasma mixture does not affect the oxygen content in the treated MWCNTs. Meanwhile, MWCNTs treated at high power (80 W) showed a reduction in oxygen functional groups in comparison with low RF power conditions. The Raman analysis was consistent with the XPS and FTIR results. The integrity of the nanotube patterns also remained damaged as observed by FE-SEM images. The MWCNTs treated in RF-DBD using the Ar/{{\\text{O}}2} plasma mixture showed improved dispersibility in deionized water. A correlation between the OES data and the observed surface characterization for an improved understanding of the functionalization of MWCNTs in Ar/{{\\text{O}}2} plasma was presented.

  17. Detection of oxygen addition peaks for terpendole E and related indole-diterpene alkaloids in a positive-mode ESI-MS.

    Science.gov (United States)

    Hongo, Yayoi; Nakamura, Takemichi; Takahashi, Shunya; Motoyama, Takayuki; Hayashi, Toshiaki; Hirota, Hiroshi; Osada, Hiroyuki; Koshino, Hiroyuki

    2014-06-01

    This report describes that a regular positive electrospray ionization mass spectrometry (MS) analysis of terpendoles often causes unexpected oxygen additions to form [M + H + O](+) and [M + H + 2O](+), which might be a troublesome in the characterization of new natural analogues. The intensities of [M + H + O](+) and [M + H + 2O](+) among terpendoles were unpredictable and fluctuated largely. Simple electrochemical oxidation in electrospray ionization was insufficient to explain the phenomenon. So we studied factors to form [M + H + O](+) and [M + H + 2O](+) using terpendole E and natural terpendoles together with some model indole alkaloids. Similar oxygen addition was observed for 1,2,3,4-tetrahydrocyclopent[b]indole, which is corresponding to the substructure of terpendole E. In tandem MS experiments, a major fragment ion at m/z 130 from protonated terpendole E was assigned to the substructure containing indole. When the [M + H + O](+) was selected as a precursor ion, the ion shifted to m/z 146. The same 16 Da shift of fragments was also observed for 1,2,3,4-tetrahydrocyclopent[b]indole, indicating that the oxygen addition of terpendole E took place at the indole portion. However, the oxygen addition was absent for some terpendoles, even whose structure resembles terpendole E. The breakdown curves characterized the tandem MS features of terpendoles. Preferential dissociation into m/z 130 suggested the protonation tendency at the indole site. Terpendoles that are preferentially protonated at indole tend to form oxygen addition peaks, suggesting that the protonation feature contributes to the oxygen additions in some degrees.

  18. Detection of oxygen addition peaks for terpendole E and related indole–diterpene alkaloids in a positive-mode ESI-MS

    Science.gov (United States)

    Hongo, Yayoi; Nakamura, Takemichi; Takahashi, Shunya; Motoyama, Takayuki; Hayashi, Toshiaki; Hirota, Hiroshi; Osada, Hiroyuki; Koshino, Hiroyuki

    2014-01-01

    This report describes that a regular positive electrospray ionization mass spectrometry (MS) analysis of terpendoles often causes unexpected oxygen additions to form [M + H + O]+ and [M + H + 2O]+, which might be a troublesome in the characterization of new natural analogues. The intensities of [M + H + O]+ and [M + H + 2O]+ among terpendoles were unpredictable and fluctuated largely. Simple electrochemical oxidation in electrospray ionization was insufficient to explain the phenomenon. So we studied factors to form [M + H + O]+ and [M + H + 2O]+ using terpendole E and natural terpendoles together with some model indole alkaloids. Similar oxygen addition was observed for 1,2,3,4-tetrahydrocyclopent[b]indole, which is corresponding to the substructure of terpendole E. In tandem MS experiments, a major fragment ion at m/z 130 from protonated terpendole E was assigned to the substructure containing indole. When the [M + H + O]+ was selected as a precursor ion, the ion shifted to m/z 146. The same 16 Da shift of fragments was also observed for 1,2,3,4-tetrahydrocyclopent[b]indole, indicating that the oxygen addition of terpendole E took place at the indole portion. However, the oxygen addition was absent for some terpendoles, even whose structure resembles terpendole E. The breakdown curves characterized the tandem MS features of terpendoles. Preferential dissociation into m/z 130 suggested the protonation tendency at the indole site. Terpendoles that are preferentially protonated at indole tend to form oxygen addition peaks, suggesting that the protonation feature contributes to the oxygen additions in some degrees. © 2014 The Authors. Journal of Mass Spectrometry published by John Wiley & Sons, Ltd. PMID:24913406

  19. Hydrothermally Driven Transformation of Oxygen Functional Groups at Multiwall Carbon Nanotubes for Improved Electrocatalytic Applications.

    Science.gov (United States)

    Suryanto, Bryan H R; Chen, Sheng; Duan, Jingjing; Zhao, Chuan

    2016-12-28

    The role of carbon nanotubes in the advancement of energy conversion and storage technologies is undeniable. In particular, carbon nanotubes have attracted significant applications for electrocatalysis. However, one central issue related to the use of carbon nanotubes is the required oxidative pretreatment that often leads to significant damage of graphitic structures which deteriorates their electrochemical properties. Traditionally, the oxidized carbon nanomaterials are treated at high temperature under an inert atmosphere to repair the oxidation-induced defect sites, which simultaneously removes a significant number of oxygen functional groups. Nevertheless, recent studies have shown that oxygen functional groups on the surface of MWCNT are the essential active centers for a number of important electrocatalytic reactions such as hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR). Herein we first show that hydrothermal treatment as a mild method to improve the electrochemical properties and activities of surface-oxidized MWCNT for OER, HER, and ORR without significantly altering the oxygen content. The results indicate that hydrothermal treatment could potentially repair the defects without significantly reducing the pre-existing oxygen content, which has never been achieved before with conventional high-temperature annealing treatment.

  20. Investigation of oxygen defects in wurtzite InN by using density functional theory

    Science.gov (United States)

    Hattori, Y.; Chubaci, J. F. D.; Matsuoka, M.; Freitas, J. A.; da Silva, A. Ferreira

    2016-12-01

    Density Functional Theory based on ab initio calculations was employed to investigate single and complex defects of oxygen in indium nitride and their influence on the optical properties. Different oxygen contents (x=1.38%, 4.16%, 5.55% and 11.11%) were considered in our study by using PBEsol-GGA and TB-mBJ for the treatment of exchange-correlation energy and potential. It was found that oxygen is energetically favorable to exist mainly as singly charged isolated defect. The results using TB-mBJ approximation predicts a narrowing of the VBM (valence band maximum) and CBM (conduction band minimum) as oxygen content increases. Nevertheless, the larger contribution of the Moss-Burstein effect leads to an effective band-gap increase, yielding absorption edge values larger than that of the intrinsic bulk indium nitride.

  1. Novel fully-BODIPY functionalized cyclotetraphosphazene photosensitizers having high singlet oxygen quantum yields

    Science.gov (United States)

    Şenkuytu, Elif; Eçik, Esra Tanrıverdi

    2017-07-01

    Novel fully-BODIPY functionalized dendrimeric cyclotetraphosphazenes (FBCP 1 and 2) have been synthesized and characterized by 1H, 13C and 31P NMR spectroscopies. The photophysical and photochemical properties of FBCP 1 and 2 are investigated in dichloromethane solution. The effectiveness of singlet oxygen generation was measured for FBCP 1 and 2 by UV-Vis spectra monitoring of the solution of 1,3-diphenylisobenzofuran (DPBF), which is a well-known trapping molecule used in detection of singlet oxygen. FBCP 1 and 2 show high molar extinction coefficients in the NIR region, good singlet oxygen quantum yields and appropriate photo degradation. The data presented in the work indicate that the dendrimeric cyclotetraphosphazenes are effective singlet oxygen photosensitizers that might be used for various areas of applications such as photodynamic therapy and photocatalysis.

  2. Oxygen defects in amorphous Al{sub 2}O{sub 3}: A hybrid functional study

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Zhendong, E-mail: zhendong.guo@epfl.ch; Ambrosio, Francesco; Pasquarello, Alfredo [Chaire de Simulation à l' Echelle Atomique (CSEA), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)

    2016-08-08

    The electronic properties of the oxygen vacancy and interstitial in amorphous Al{sub 2}O{sub 3} are studied via ab initio molecular dynamics simulations and hybrid functional calculations. Our results indicate that these defects do not occur in amorphous Al{sub 2}O{sub 3}, due to structural rearrangements which assimilate the defect structure and cause a delocalization of the associated defect levels. The imbalance of oxygen leads to a nonstoichiometric compound in which the oxygen occurs in the form of O{sup 2–} ions. Intrinsic oxygen defects are found to be unable to trap excess electrons. For low Fermi energies, the formation of peroxy linkages is found to be favored leading to the capture of holes. The relative +2/0 defect levels occur at 2.5 eV from the valence band.

  3. [Sauna effect on blood oxygen transport function and proxidant/antioxidant balance in youths].

    Science.gov (United States)

    Zinchuk, V V; Zhad'ko, D D

    2012-01-01

    There was investigated sauna effect on blood oxygen transport function and proxidant/antioxidant balance in 18 to 22 years old males. Subjects being tested underwent thermal exposure once per week over a period of 5 months (20 procedures). There were two exposure over the course of sauna bathing (temperature 85-90 degrees C, humidity 10-15%): the first exposure lasted for 5 minutes and the second one for 10 minutes. Dry air sauna in youth's leads to respiratory alkalosis, increases pO2, decreases haemoglobin binding capacity to venous blood oxygen thus facilitating oxygen transport into body tissues. Single sauna visit results in oxidative stress (augmentation of free radical processes and deterioration of antioxidant defence mechanisms), while its manifestations being diminished after multiple thermal exposures. Increase in nitrogen monoxide formation being observed might matter for the modification of the oxygen dependent processes of the human body.

  4. Tailoring p- and n- type semiconductor through site selective oxygen doping in Cu3N: density functional studies

    Science.gov (United States)

    Sahoo, Guruprasad; Kashikar, Ravi; Jain, Mahaveer K.; Nanda, B. R. K.

    2016-06-01

    Using ab initio density functional calculations, we have investigated the stability and electronic structure of pure and oxygen doped semiconducting Cu3N. The oxygen can be accommodated in the system without structural instability as the formation energy either decreases when oxygen substitutes nitrogen, or remains nearly same when oxygen occupies the interstitial position. The interstitial oxygen (OI) prefers to stabilize in the unusual charge neutral state and acts as an acceptor to make the system a p-type degenerate semiconductor. In this case the hole pockets are formed by the partially occupied OI-p states. On the other hand, oxygen substituting nitrogen (OS) stabilizes in its usual -2 charge state and acts as a donor to make the system an n-type degenerate semiconductor. The electron pockets are formed by the conducting Cu-p states. In the case of mixed doping, holes are gradually compensated by the donor electrons and an intrinsic gap is obtained for {{{Cu}}}3{{{N}}}{1-2{x}}{{{{O}}}{{S}}}2{x}{{{{O}}}{{I}}}{x} stoichiometry. Our calculations predict the nature of doping as well as optical band gap ({{E}{{g}}}{{o}{{p}}{{t}}}) variation in experimentally synthesized copper oxynitride. While interstitial doping contracts the lattice and increases the {{E}{{g}}}{{o}{{p}}{{t}}}, substitutional doping increases both lattice size and {{E}{{g}}}{{o}{{p}}{{t}}}. Mixed doping reduces {{E}{{g}}}{{o}{{p}}{{t}}}. Additionally we show that a rare intra-atomic d-p optical absorption can be realized in the pristine Cu3N as the Fermi level lies in the gap between the Cu-d dominated anti-bonding valence state and Cu-p conducting state.

  5. The oxygen reduction reaction mechanism on Pt(111) from density functional theory calculations

    DEFF Research Database (Denmark)

    Tripkovic, Vladimir; Skulason, Egill; Siahrostami, Samira;

    2010-01-01

    We study the oxygen reduction reaction (ORR) mechanism on a Pt(1 1 1) surface using density functional theory calculations We find that at low overpotentials the surface is covered with a half dissociated water layer We estimate the barrier for proton transfer to this surface and the barrier for ...

  6. Quantifying the functional responses of vegetation to drought and oxygen stress in temperate ecosystems

    NARCIS (Netherlands)

    Douma, J.C.; Bardin, V.; Bartholomeus, R.P.; Bodegom, van P.M.

    2012-01-01

    1. Our understanding of the generality of plant functional responses to water availability is limited; current field studies use either very rough approximations of water and oxygen availability or only focus on water-stressed ecosystems. Studies that relate species' responses to a surplus of water

  7. Performance Evaluation of an Oxygen Sensor as a Function of the Samaria Doped Ceria Film Thickness

    Energy Technology Data Exchange (ETDEWEB)

    Sanghavi, Rahul P.; Nandasiri, Manjula I.; Kuchibhatla, Satyanarayana V N T; Nachimuthu, Ponnusamy; Engelhard, Mark H.; Shutthanandan, V.; Jiang, Weilin; Thevuthasan, Suntharampillai; Kayani, Asghar N.; Prasad, Shalini

    2010-12-01

    The current demand in the automobile industry is in the control of air-fuel mixture in the combustion engine of automobiles. Oxygen partial pressure can be used as an input parameter for regulating or controlling systems in order to optimize the combustion process. Our goal is to identify and optimize the material system that would potentially function as the active sensing material for such a device that monitors oxygen partial pressure in these systems. We have used thin film samaria doped ceria (SDC) as the sensing material for the sensor operation, exploiting the fact that at high temperatures, oxygen vacancies generated due to samarium doping act as conducting medium for oxygen ions which hop through the vacancies from one side to the other contributing to an electrical signal. We have recently established that 6 atom % Sm doping in ceria films has optimum conductivity. Based on this observation, we have studied the variation in the overall conductivity of 6 atom % samaria doped ceria thin films as a function of thickness in the range of 50 nm to 300 nm at a fixed bias voltage of 2 volts. A direct proportionality in the increase in the overall conductivity is observed with the increase in sensing film thickness. For a range of oxygen pressure values from 1 mTorr to 100 Torr, a tolerable hysteresis error, good dynamic response and a response time of less than 10 seconds was observed

  8. SELECTIVE OXIDATION OF ALCOHOLS BY MOLECULAR OXYGEN OVER A PD/MGO CATALYST IN THE ABSENCE OF ANY ADDITIVES

    Science.gov (United States)

    Selective oxidation of alcohols to the corresponding carbonyl products using molecular oxygen is achieved over a simple and easily recyclable 1% Pd/MgO impregnated heterogeneous catalyst in the presence of trifluorotoluene. A variety of activated and non-activated alcohols are ef...

  9. Investigating Functional Extension of Optical Coherence Tomography for Spectroscopic Analysis of Blood Oxygen Saturation

    Science.gov (United States)

    Chen, Siyu

    animals in situ. Thus, one question demanding immediate investigation is how the choice of illumination wavelength bands affect the performance of OCT oximetry. This is addressed using two approaches, (1) a numerical study using Monte Carlo methods, and (2) animal experiments involving the development of a vis- and NIR- dual band OCT imaging system. It is indicated that visible light is more suitable for OCT oximetry applications due to the higher absorption contrast between oxyhemoglobin and deoxyhemoglobin. The accuracy of OCT retinal oximetry is established to be around 5 percentage points (pp) regardless of physiological variation of blood sO2, vessel diameter, and is robust over a reasonable selection of sampling geometry. Despite the higher optical scattering experienced in the visible wavelength range, vis-OCT also demonstrated comparable or better imaging capability in terms of resolving anatomical features, imaging resolution, and retrieving other functional indicators such as blood flow. Besides retrieving blood sO2 from vessels directly visualized in structural OCT images, the possibility of using dynamic motion contrast to enhance otherwise non-resolvable micro vessels is investigated. Using this approach, it is subsequently proved that OCT angiography (OCTA) encodes blood absorption contrast and can be used to calculate sO2 within microvasculature. For the first time, measurements of relative sO2 change are reported in choroidal capillaries following inhalation oxygen challenge. This dissertation also represents a translational study that seeks to move technologies developed in the laboratory into real clinical applications. A vis-OCT imaging system with integrated scanning laser ophthalmoscope (SLO) is developed for human subjects. This prototype system can provide three-dimensional (3D) structural images and cross-sections of human fundus similar to that from commercial NIR-OCT systems. In addition, blood sO2 within retinal circulation is successfully

  10. Influence of perioperative oxygen fraction on pulmonary function after abdominal surgery: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Staehr Anne K

    2012-07-01

    Full Text Available Abstract Background A high perioperative inspiratory oxygen fraction (FiO2 may reduce the frequency of surgical site infection. Perioperative atelectasis is caused by absorption, compression and reduced function of surfactant. It is well accepted, that ventilation with 100% oxygen for only a few minutes is associated with significant formation of atelectasis. However, it is still not clear if a longer period of 80% oxygen results in more atelectasis compared to a low FiO2. Our aim was to assess if a high FiO2 is associated with impaired oxygenation and decreased pulmonary functional residual capacity (FRC. Methods Thirty-five patients scheduled for laparotomy for ovarian cancer were randomized to receive either 30% oxygen (n = 15 or 80% oxygen (n = 20 during and for 2 h after surgery. The oxygenation index (PaO2/FiO2 was measured every 30 min during anesthesia and 90 min after extubation. FRC was measured the day before surgery and 2 h after extubation by a rebreathing method using the inert gas SF6. Results Five min after intubation, the median PaO2/FiO2 was 69 kPa [53-71] in the 30%-group vs. 60 kPa [47-69] in the 80%-group (P = 0.25. At the end of anesthesia, the PaO2/FiO2 was 58 kPa [40-70] vs. 57 kPa [46-67] in the 30%- and 80%-group, respectively (P = 0.10. The median FRC was 1993 mL [1610-2240] vs. 1875 mL [1545-2048] at baseline and 1615 mL [1375-2318] vs. 1633 mL [1343-1948] postoperatively in the 30%- and 80%-group, respectively (P = 0.70. Conclusion We found no significant difference in oxygenation index or functional residual capacity between patients given 80% and 30% oxygen for a period of approximately 5 hours. Trial registration ClinicalTrials.gov Identifier: NCT00637936.

  11. Protection of melatonin against damage of sperm mito-chondrial function induced by reactive oxygen species

    Institute of Scientific and Technical Information of China (English)

    Xue-JunShang; Yu-FengHuang; Zhang-QunYe; XiaoYu; Wan-JiaGu

    2004-01-01

    Aim: To study the mitochondrial function damage of sperm in-duced by reactive oxygen species (ROS) and the protection of melatonin (MLT) against the damage. Methods: Normal function spermatozoa were selected from semen samples by Percoll gradi-ent centrifugation technique. The ROS generated by the hypoxan-thine xanthine oxidase system was incubated with the normal sper-matozoa in the presence or absence of MLT (6 retool/L) for 30 and 60 minutes.

  12. Brain tissue oxygen amperometry in behaving rats demonstrates functional dissociation of dorsal and ventral hippocampus during spatial processing and anxiety

    Science.gov (United States)

    McHugh, Stephen B; Fillenz, Marianne; Lowry, John P; Rawlins, J Nicolas P; Bannerman, David M

    2011-01-01

    Traditionally, the function of the hippocampus (HPC) has been viewed in unitary terms, but there is growing evidence that the HPC is functionally differentiated along its septotemporal axis. Lesion studies in rodents and functional brain imaging in humans suggest a preferential role for the septal HPC in spatial learning and a preferential role for the temporal HPC in anxiety. To better enable cross-species comparison, we present an in vivo amperometric technique that measures changes in brain tissue oxygen at high temporal resolution in freely-moving rats. We recorded simultaneously from the dorsal (septal; dHPC) and ventral (temporal; vHPC) HPC during two anxiety tasks and two spatial tasks on the radial maze. We found a double-dissociation of function in the HPC, with increased vHPC signals during anxiety and increased dHPC signals during spatial processing. In addition, dHPC signals were modulated by spatial memory demands. These results add a new dimension to the growing consensus for a differentiation of HPC function, and highlight tissue oxygen amperometry as a valuable tool to aid translation between animal and human research. PMID:21105915

  13. Functional imaging of muscle oxygenation using a 200-channel cw NIRS system

    Science.gov (United States)

    Yamamoto, Katsuyuki; Niwayama, Masatsugu; Kohata, Daisuke; Kudo, Nobuki; Hamaoka, Takatumi; Kime, Ryotaro; Katsumura, Toshihito

    2001-06-01

    Functional imaging of muscle oxygenation using NIRS is a promising technique for evaluation of the heterogeneity of muscle function and diagnosis of peripheral vascular disease or muscle injury. We have developed a 200-channel imaging system that can measure the changes in oxygenation and blood volume of muscles and that covers wider area than previously reported systems. Our system consisted of 40 probes, a multiplexer for switching signals to and from the probes, and a personal computer for obtaining images. In each probe, one two-wavelength LED (770 and 830 nm) and five photodiodes were mounted on a flexible substrate. In order to eliminate the influence of a subcutaneous fat layer, a correction method, which we previously developed, was also used in imaging. Thus, quantitative changes in concentrations of oxy- and deoxy-hemoglobin were obtained. Temporal resolution was 1.5 s and spatial resolution was about 20 mm, depending on probe separations. Exercise tests (isometric contraction of 50% MVC) on the thigh with and without arterial occlusion were conducted, and changes in muscle oxygenation were imaged using the developed system. Results showed that the heterogeneity of deoxygenation and reoxygenation during exercise and recovery periods, respectively, were clearly observed. These results suggest that optical imaging of dynamic change in muscle oxygenation using NIRS would be useful not only for basic physiological studies but also for clinical applications with respect to muscle functions.

  14. Testosterone improves erectile function through inhibition of reactive oxygen species generation in castrated rats

    Directory of Open Access Journals (Sweden)

    Rui Li

    2016-05-01

    Full Text Available Testosterone is overwhelmingly important in regulating erectile physiology. However, the associated molecular mechanisms are poorly understood. The purpose of this study was to explore the effects and mechanisms of testosterone in erectile dysfunction (ED in castrated rats. Forty male Sprague-Dawley rats were randomized to four groups (control, sham-operated, castration and castration-with-testosterone-replacement. Reactive oxygen species (ROS production was measured by dihydroethidium (DHE staining. Erectile function was assessed by the recording of intracavernous pressure (ICP and mean arterial blood pressure (MAP. Protein expression levels were examined by western blotting. We found that castration reduced erectile function and that testosterone restored it. Nitric oxide synthase (NOS activity was decrease in the castrated rats, and testosterone administration attenuated this decrease (each p < 0.05. The testosterone, dihydrotestosterone, cyclic guanosine monophosphate (cGMP and cyclic adenosine monophosphate (cAMP concentrations were lower in the castrated rats, and testosterone restored these levels (each p < 0.05. Furthermore, the cyclooxygenase-2 (COX-2 and prostacyclin synthase (PTGIS expression levels and phospho-endothelial nitric oxide synthase (p-eNOS, Ser1177/endothelial nitric oxide synthase (eNOS ratio were reduced in the castrated rats compared with the controls (each p < 0.05. In addition, the p40phox and p67phox expression levels were increased in the castrated rats, and testosterone reversed these changes (each p < 0.05. Overall, our results demonstrate that testosterone ameliorates ED after castration by reducing ROS production and increasing the activity of the eNOS/cGMP and COX-2/PTGIS/cAMP signaling pathways.

  15. Testosterone improves erectile function through inhibition of reactive oxygen species generation in castrated rats

    Science.gov (United States)

    Li, Rui; Meng, Xianghu; Zhang, Yan; Wang, Tao; Yang, Jun; Niu, Yonghua; Cui, Kai; Wang, Shaogang

    2016-01-01

    Testosterone is overwhelmingly important in regulating erectile physiology. However, the associated molecular mechanisms are poorly understood. The purpose of this study was to explore the effects and mechanisms of testosterone in erectile dysfunction (ED) in castrated rats. Forty male Sprague-Dawley rats were randomized to four groups (control, sham-operated, castration and castration-with-testosterone-replacement). Reactive oxygen species (ROS) production was measured by dihydroethidium (DHE) staining. Erectile function was assessed by the recording of intracavernous pressure (ICP) and mean arterial blood pressure (MAP). Protein expression levels were examined by western blotting. We found that castration reduced erectile function and that testosterone restored it. Nitric oxide synthase (NOS) activity was decrease in the castrated rats, and testosterone administration attenuated this decrease (each p < 0.05). The testosterone, dihydrotestosterone, cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) concentrations were lower in the castrated rats, and testosterone restored these levels (each p < 0.05). Furthermore, the cyclooxygenase-2 (COX-2) and prostacyclin synthase (PTGIS) expression levels and phospho-endothelial nitric oxide synthase (p-eNOS, Ser1177)/endothelial nitric oxide synthase (eNOS) ratio were reduced in the castrated rats compared with the controls (each p < 0.05). In addition, the p40phox and p67phox expression levels were increased in the castrated rats, and testosterone reversed these changes (each p < 0.05). Overall, our results demonstrate that testosterone ameliorates ED after castration by reducing ROS production and increasing the activity of the eNOS/cGMP and COX-2/PTGIS/cAMP signaling pathways. PMID:27168996

  16. Adsorption of atomic nitrogen and oxygen on [Formula: see text] surface: a density functional theory study.

    Science.gov (United States)

    Breedon, M; Spencer, M J S; Yarovsky, I

    2009-04-08

    The adsorption of atomic nitrogen and oxygen on the ([Formula: see text]) crystal face of zinc oxide (ZnO) was studied. Binding energies, workfunction changes, vibrational frequencies, charge density differences and electron localization functions were calculated. It was elucidated that atomic oxygen binds more strongly than nitrogen, with the most stable [Formula: see text] structure exhibiting a binding energy of -2.47 eV, indicating chemisorption onto the surface. Surface reconstructions were observed for the most stable minima of both atomic species. Positive workfunction changes were calculated for both adsorbed oxygen and nitrogen if the adsorbate interacted with zinc atoms. Negative workfunction changes were calculated when the adsorbate interacted with both surface oxygen and zinc atoms. Interactions between the adsorbate and the surface zinc atoms resulted in ionic-type bonding, whereas interactions with oxygen atoms were more likely to result in the formation of covalent-type bonding. The positive workfunction changes correlate with an experimentally observed increase in resistance of ZnO conductometric sensor devices.

  17. Exercise capacity in the Bidirectional Glenn physiology: Coupling cardiac index, ventricular function and oxygen extraction ratio.

    Science.gov (United States)

    Vallecilla, Carolina; Khiabani, Reza H; Trusty, Phillip; Sandoval, Néstor; Fogel, Mark; Briceño, Juan Carlos; Yoganathan, Ajit P

    2015-07-16

    In Bi-directional Glenn (BDG) physiology, the superior systemic circulation and pulmonary circulation are in series. Consequently, only blood from the superior vena cava is oxygenated in the lungs. Oxygenated blood then travels to the ventricle where it is mixed with blood returning from the lower body. Therefore, incremental changes in oxygen extraction ratio (OER) could compromise exercise tolerance. In this study, the effect of exercise on the hemodynamic and ventricular performance of BDG physiology was investigated using clinical patient data as inputs for a lumped parameter model coupled with oxygenation equations. Changes in cardiac index, Qp/Qs, systemic pressure, oxygen extraction ratio and ventricular/vascular coupling ratio were calculated for three different exercise levels. The patient cohort (n=29) was sub-grouped by age and pulmonary vascular resistance (PVR) at rest. It was observed that the changes in exercise tolerance are significant in both comparisons, but most significant when sub-grouped by PVR at rest. Results showed that patients over 2 years old with high PVR are above or close to the upper tolerable limit of OER (0.32) at baseline. Patients with high PVR at rest had very poor exercise tolerance while patients with low PVR at rest could tolerate low exercise conditions. In general, ventricular function of SV patients is too poor to increase CI and fulfill exercise requirements. The presented mathematical model provides a framework to estimate the hemodynamic performance of BDG patients at different exercise levels according to patient specific data.

  18. Morphology and function of Bast's valve : additional insight in its functioning using 3D-reconstruction

    NARCIS (Netherlands)

    Hofman, R.; Segenhout, J. M.; Buytaert, J. A. N.; Dirckx, J. J. J.; Wit, H. P.

    2008-01-01

    The utriculo-endolymphatic valve was discovered by Bast in 1928. The function of Bast's valve is still unclear. By means of orthogonal-plane fluorescence optical sectioning (OPFOS) microscopy 3D-reconstructions of the valve and its surrounding region are depicted. The shape of the duct at the utricu

  19. Graphene oxide functionalized with methylene blue and its performance in singlet oxygen generation

    Energy Technology Data Exchange (ETDEWEB)

    Wojtoniszak, M., E-mail: mwojtoniszak@zut.edu.pl [West Pomeranian University of Technology in Szczecin, Institute of Chemical and Environment Engineering, Pulaskiego 10, 70-322 Szczecin (Poland); Rogińska, D.; Machaliński, B. [Pomeranian Medical University, Department of General Pathology, Powstańców Wlkp. 72, 70-111 Szczecin (Poland); Drozdzik, M. [Pomeranian Medical University, Department of Pharmacology, Powstańców Wlkp. 72, 70-111 Szczecin (Poland); Mijowska, E. [West Pomeranian University of Technology in Szczecin, Institute of Chemical and Environment Engineering, Pulaskiego 10, 70-322 Szczecin (Poland)

    2013-07-15

    Graphical abstract: - Highlights: • Adsorption of methylene blue (MB) on graphene oxide (GO). • Characterization of graphene oxide–methylene blue nanocomposite (MB–GO). • Examination of MB–GO efficiency in singlet oxygen generation (SOG). • MB–GO performs higher SOG efficiency than pristine MB. - Abstract: Due to unique electronic, mechanical, optical and structural properties, graphene has shown promising applications in many fields, including biomedicine. One of them is noninvasive anticancer therapy – photodynamic therapy (PDT), where singlet oxygen (SO), generated under the irradiation of light with appropriate wavelengths, kills cancer cells. In this study, authors report graphene oxide (GO) noncovalent functionalization with methylene blue (MB). MB molecules underwent adsorption on the surface of GO. Detailed characterization of the obtained material was carried out with UV–vis spectroscopy, Raman spectroscopy, FT-IR spectroscopy, and confocal laser scanning microscopy. Furthermore, its performance in singlet oxygen generation (SOG) under irradiation of laser with excitation wavelengths of 785 nm was investigated. Interestingly, GO functionalized with MB (MB–GO) showed enhanced efficiency in singlet oxygen generation compared to pristine MB. The efficiency in SOG was detected by photobleaching of 9,10-anthracenediyl-bis(methylene)dimalonic acid (ABMDMA). These results indicate the material is promising in PDT anticancer therapy and further in vitro and in vivo studies are required.

  20. In vivo measurement of changes in venous blood-oxygenation with high resolution functional MRI at 0.95 tesla by measuring changes in susceptibility and velocity.

    Science.gov (United States)

    Hoogenraad, F G; Reichenbach, J R; Haacke, E M; Lai, S; Kuppusamy, K; Sprenger, M

    1998-01-01

    High-resolution functional imaging experiments at 0.95 Tesla have been performed to determine the changes in oxygen saturation in pial veins during motor activation by measuring both flow and susceptibility changes in the blood. Averaging across subjects, mean values for the change of the oxygenation level, deltaY = 0.16 +/- 0.08 (n = 7) and deltaY = 0.13 +/- 0.09 (n = 4), were obtained from the susceptibility sensitive and the flow sensitive acquisitions, respectively. The results suggest that the increase in blood flow is largely uncoupled from the oxygen consumption. The quoted errors reflect mainly the intersubject variability. In addition, low-resolution echo planar imaging (EPI) measurements were performed on the same volunteers to quantify signal intensity changes. Using the measured change in oxygenation, the observed signal changes in the EPI experiments can be attributed to a 5% venous blood volume.

  1. Functionalized 3D Architected Materials via Thiol-Michael Addition and Two-Photon Lithography.

    Science.gov (United States)

    Yee, Daryl W; Schulz, Michael D; Grubbs, Robert H; Greer, Julia R

    2017-04-01

    Fabrication of functionalized 3D architected materials is achieved by a facile method using functionalized acrylates synthesized via thiol-Michael addition, which are then polymerized using two-photon lithography. A wide variety of functional groups can be attached, from Boc-protected amines to fluoroalkanes. Modification of surface wetting properties and conjugation with fluorescent tags are demonstrated to highlight the potential applications of this technique. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Bicyclo[3.2.1]octane synthons from cyclopropenes: functionalization of cycloadducts by nucleophilic additions.

    Science.gov (United States)

    Orugunty, Ravi S; Wright, Dennis L; Battiste, Merle A; Helmich, Richard J; Abboud, Khalil

    2004-01-23

    It has been known for several decades that a highly functionalized family of tetrahalobicyclo[3.2.1]octadienes are readily available through the cycloaddition of furan or cyclopentadiene with either tetrachloro- or tetrabromocyclopropene. However, the application of these highly functionalized building blocks in synthesis has remained relatively unexplored in relation to their better-known counterparts derived through oxyallyl cation additions. As a first step toward utilizing these highly versatile intermediates in synthesis, a study of the addition of various nucleophiles to the halogenated nucleus has been conducted. It has been found that these halogenated systems are amenable to a wide range of functionalizations in high yields and with good selectivities.

  3. Generalized neurofuzzy network modeling algorithms using Bézier-Bernstein polynomial functions and additive decomposition.

    Science.gov (United States)

    Hong, X; Harris, C J

    2000-01-01

    This paper introduces a new neurofuzzy model construction algorithm for nonlinear dynamic systems based upon basis functions that are Bézier-Bernstein polynomial functions. This paper is generalized in that it copes with n-dimensional inputs by utilising an additive decomposition construction to overcome the curse of dimensionality associated with high n. This new construction algorithm also introduces univariate Bézier-Bernstein polynomial functions for the completeness of the generalized procedure. Like the B-spline expansion based neurofuzzy systems, Bézier-Bernstein polynomial function based neurofuzzy networks hold desirable properties such as nonnegativity of the basis functions, unity of support, and interpretability of basis function as fuzzy membership functions, moreover with the additional advantages of structural parsimony and Delaunay input space partition, essentially overcoming the curse of dimensionality associated with conventional fuzzy and RBF networks. This new modeling network is based on additive decomposition approach together with two separate basis function formation approaches for both univariate and bivariate Bézier-Bernstein polynomial functions used in model construction. The overall network weights are then learnt using conventional least squares methods. Numerical examples are included to demonstrate the effectiveness of this new data based modeling approach.

  4. Molybdenum and tungsten oxygen transferases--and functional diversity within a common active site motif.

    Science.gov (United States)

    Pushie, M Jake; Cotelesage, Julien J; George, Graham N

    2014-01-01

    Molybdenum and tungsten are the only second and third-row transition elements with a known function in living organisms. The molybdenum and tungsten enzymes show common structural features, with the metal being bound by a pyranopterin-dithiolene cofactor called molybdopterin. They catalyze a variety of oxygen transferase reactions coupled with two-electron redox chemistry in which the metal cycles between the +6 and +4 oxidation states usually with water, either product or substrate, providing the oxygen. The functional roles filled by the molybdenum and tungsten enzymes are diverse; for example, they play essential roles in microbial respiration, in the uptake of nitrogen in green plants, and in human health. Together, the enzymes form a superfamily which is among the most prevalent known, being found in all kingdoms of life. This review discusses what is known of the active site structures and the mechanisms, together with some recent insights into the evolution of these important enzyme systems.

  5. Exopolysaccharide from Lactobacillus fermentum Lf2 and its functional characterization as a yogurt additive.

    Science.gov (United States)

    Ale, Elisa C; Perezlindo, Marcos J; Burns, Patricia; Tabacman, Eduardo; Reinheimer, Jorge A; Binetti, Ana G

    2016-11-01

    Lactobacillus fermentum Lf2 is a strain which is able to produce high levels (approximately 1 g/l) of crude exopolysaccharide (EPS) when it is grown in optimised conditions. The aim of this work was to characterize the functional aspects of this EPS extract, focusing on its application as a dairy food additive. Our findings are consistent with an EPS extract that acts as moderate immunomodulator, modifying s-IgA and IL-6 levels in the small intestine when added to yogurt and milk, respectively. Furthermore, this EPS extract, in a dose feasible to use as a food additive, provides protection against Salmonella infection in a murine model, thus representing a mode of action to elicit positive health benefits. Besides, it contributes to the rheological characteristics of yogurt, and could function as a food additive with both technological and functional roles, making possible the production of a new functional yogurt with improved texture.

  6. Impact of Hyperbaric Oxygenation on the Phagocytosis-Stimulating Function of the Operated Liver

    OpenAIRE

    Savilov, P. N.

    2008-01-01

    Objective: to study the ability of hyperbaric oxygenation (HBO) to eliminate impaired phagocytosis-stimulating hepatic function caused by hepatectomy (HE). Material and methods. Experiments were conducted on 82 outbred female albino rats exposed to HE (15—20% of the organ mass) and HBO at 3 ata for 50 min once daily three times within the first three days after surgery. The capacities of neutrophils and monocytes of arterial (aorta) and venous (portal vein, hepatic veins) blood to ingest and ...

  7. Acute cocoa flavanol improves cerebral oxygenation without enhancing executive function at rest or after exercise.

    Science.gov (United States)

    Decroix, Lieselot; Tonoli, Cajsa; Soares, Danusa D; Tagougui, Semah; Heyman, Elsa; Meeusen, Romain

    2016-12-01

    Acute exercise-induced improvements in cognitive function are accompanied by increased (cerebral) blood flow and increased brain-derived neurotrophic factor (BDNF) levels. Acute cocoa flavanol (CF) intake may improve cognitive function, cerebral blood flow (in humans), and BNDF levels (in animals). This study investigated (i) the effect of CF intake in combination with exercise on cognitive function and (ii) cerebral hemodynamics and BDNF in response to CF intake and exercise. Twelve healthy men participated in this randomized, double-blind, crossover study. Participants performed a cognitive task (CT) at 100 min after acute 903-mg CF or placebo (PL) intake, followed by a 30-min time-trial. Immediately after this exercise, the same CT was performed. Prefrontal near-infrared spectroscopy was applied during CT and exercise to measure changes in oxygenated (ΔHbO2), deoxygenated (ΔHHb), and total haemoglobin (ΔHbtot) and blood samples were drawn and analyzed for BDNF. Reaction time was faster postexercise, but was not influenced by CF. ΔHbO2 during the resting CT was increased by CF, compared with PL. ΔHbO2, ΔHHb, and ΔHbtot increased in response to exercise without any effect of CF. During the postexercise cognitive task, there were no hemodynamic differences between CF or PL. Serum BDNF was increased by exercise, but was not influenced by CF. In conclusion, at rest, CF intake increased cerebral oxygenation, but not BDNF concentrations, and no impact on executive function was detected. This beneficial effect of CF on cerebral oxygenation at rest was overruled by the strong exercise-induced increases in cerebral perfusion and oxygenation.

  8. Latency to CNS oxygen toxicity in rats as a function of PCO(2) and PO(2).

    Science.gov (United States)

    Arieli, R; Ertracht, O

    1999-01-01

    Central nervous system (CNS) oxygen toxicity can occur as convulsions and loss of consciousness, without any premonitory symptoms. We have made a quantitative study of the effect of inspired carbon dioxide on sensitivity to oxygen toxicity in the rat. Rats were exposed to four oxygen pressures (PO(2); 456, 507, 608 and 709 kPa) and an inspired partial pressure of carbon dioxide (PCO(2)) in the range 0-12 kPa until the appearance of the electroencephalograph first electrical discharge (FED) that precedes the clinical convulsions. Exposures were conducted at a thermoneutral temperature of 27 degrees C. Latency to the FED decreased linearly with the increase in PCO(2) at all four PO(2) values studied. This decrease, which is probably related to the cerebral vasodilatory effect of carbon dioxide, reached a minimal value that remained constant on further elevation of PCO(2). The slopes (absolute value) and intercepts of latency to the FED as a function of carbon dioxide decreased with the increase in PO(2). This log-linear relationship made possible the derivation of equations that describe latency to the FED as a function of both PO(2) and PCO(2) in the PCO(2) - dependent range: Latency (min) = e((5.19-0.0040)(P)(O(2)))-e((2.77-0.0034)(P)(O(2))) x PCO(2) (kPa), and in the PCO(2)-independent range: Latency(min) = e((2.44-0. 0009)(P)(O(2))). A PCO(2) as low as 1 kPa significantly reduced the latency to the FED. It is suggested that in closed-circuit oxygen diving, any accumulation of carbon dioxide should be avoided in order to minimize the risk of CNS oxygen toxicity.

  9. The Influence of Micro-Oxygen Addition on Desulfurization Performance and Microbial Communities during Waste-Activated Sludge Digestion in a Rusty Scrap Iron-Loaded Anaerobic Digester

    Directory of Open Access Journals (Sweden)

    Renjun Ruan

    2017-02-01

    Full Text Available In this study, micro-oxygen was integrated into a rusty scrap iron (RSI-loaded anaerobic digester. Under an optimal RSI dosage of 20 g/L, increasing O2 levels were added stepwise in seven stages in a semi-continuous experiment. Results showed the average methane yield was 306 mL/g COD (chemical oxygen demand, and the hydrogen sulphide (H2S concentration was 1933 ppmv with RSI addition. O2 addition induced the microbial oxidation of sulphide by stimulating sulfur-oxidizing bacteria and chemical corrosion of iron, which promoted the generation of FeS and Fe2S3. In the 6th phase of the semi-continuous test, deep desulfurization was achieved without negatively impacting system performance. Average methane yield was 301.1 mL/g COD, and H2S concentration was 75 ppmv. Sulfur mass balance was described, with 84.0%, 11.90% and 0.21% of sulfur present in solid, liquid and gaseous phases, respectively. The Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE analysis revealed that RSI addition could enrich the diversity of hydrogenotrophic methanogens and iron-reducing bacteria to benefit methanogenesis and organic mineralization, and impoverish the methanotroph (Methylocella silvestris to reduce the consumption of methane. Micro-oxygen supplementation could enhance the diversity of iron-oxidizing bacteria arising from the improvement of Fe(II release rate and enrich the sulphur-oxidising bacteria to achieved desulfurization. These results demonstrated that RSI addition in combination with micro-oxygenation represents a promising method for simultaneously controlling biogas H2S concentration and improving digestion performance.

  10. Effects of Additional Oxygen Flow on the Optical and Electrical Properties of Ion Beam Sputtering Deposited Molybdenum-Doped Zinc Oxide Layer

    Directory of Open Access Journals (Sweden)

    Chin-Chiuan Kuo

    2012-01-01

    Full Text Available The transparent conductive molybdenum-doped zinc oxide (MZO was deposited onto a flexible polyethersulfone (PES substrate by using an ion beam sputtering system. An argon ion beam was used to sputter an MZO target at constant pressure of 0.67 Pa and substrate temperature of 130∘C with varying the oxygen flow rate from 0 to 12 sccm. The influences of additional oxygen flow on the microstructure, optical, and electrical properties of films were investigated. The obtained MZO films present a crystalline structure. With increasing the oxygen flow rate, their electrical resistivity increases, and the optical band gap decreases from 3.46 to 3.20 eV. The film deposited in the atmosphere without introducing oxygen exhibits the best optical transmittance of 82.9% at 550 nm wavelength, electrical resistivity of 8.32 × 10−3 Ω cm, carrier concentration of 6.82 × 1020 cm−3, and carrier mobility of 2.45 cm2/Vs.

  11. On the Functionality Selection Principle for High Voltage Lithium-ion Battery Electrolyte Additives

    Energy Technology Data Exchange (ETDEWEB)

    Su, Chi-Cheung; He, Meinan; Peebles, Cameron; Tornheim, Adam P.; Liao, Chen; Zhang, Lu; Wang, Jie; Zhang, Zhengcheng

    2017-09-13

    A new class of electrolyte additives based on cyclic fluorinated phosphate esters was rationally designed and identified as being able to stabilize the surface of a LiNi0.5Mn0.3Co0.2O2 (NMC532) cathode when cycled at potentials higher than 4.6 V vs Li+/Li. Cyclic fluorinated phosphates were designed to incorporate functionalities of various existing additives to maximize their utilization. The synthesis and characterization of these new additives are described and their electrochemical performance in a NMC532/graphite cell cycled between 4.6 and 3.0 V are investigated. With 1.0 wt % 2-(2,2,2-trifluoroethoxy)-1,3,2-dioxaphospholane 2-oxide (TFEOP) in the conventional electrolyte the NMC532/graphite cell exhibited much improved capacity retention compared to that without any additive. The additive is believed to form a passivation layer on the surface of the cathode via a sacrificial polymerization reaction as evidenced by X-ray photoelectron spectroscopy (XPS) and nuclear magnetic resonsance (NMR) analysis results. The rational pathway of a cathode-electrolyte-interface formation was proposed for this type of additive. Both experimental results and the mechanism hypothesis suggest the effectiveness of the additive stems from both the polymerizable cyclic ring and the electron-withdrawing fluorinated alkyl group in the phosphate molecular structure. The successful development of cyclic fluorinated phosphate additives demonstrated that this new functionality selection principle, by incorporating useful functionalities of various additives into one molecule, is an effective approach for the development of new additives.

  12. Metal complexes with oxygen-functionalized NHC ligands: synthesis and applications.

    Science.gov (United States)

    Hameury, Sophie; de Frémont, Pierre; Braunstein, Pierre

    2017-02-06

    Ligand design has met with considerable success with both categories of hybrid ligands, which are characterized by chemically different donor groups, and of N-heterocyclic carbenes (NHCs). Their spectacular development and diversity are attracting worldwide interest and offers almost unlimited diversity and potential in e.g. coordination/organometallic main group and transition metal chemistry, catalysis, medicinal chemistry and materials science. This review aims at providing a comprehensive update on a specific class of ligands that has enjoyed much attention in the past few years, at the intersection between the two categories mentioned above, that of hybrid NHC ligands in which the functionality associated with the carbene donor is of the oxygen-donor type. For each type of oxygen-donor present in such chelating (Section 1) or bridging (Section 2) hybrid ligands, we will examine the synthesis, structures and reactivity of their metal complexes and their applications, with a special focus on homogeneous catalysis (Section 3). Thus, hydrogenation, C-H bond activation, C-C, C-N, C-O bond formation, hydrolysis of silanes, oligomerization, polymerization, metathesis, hydrosilylation, C-C bond cleavage, acceptorless dehydrogenation, dehalogenation/hydrogen transfer, oxidation and reduction reactions will be successively presented in a tabular manner, to facilitate an overview and a rapid identification of the relevant publications describing which metals associated with a given oxygen functionality are most suitable. The literature coverage includes the year 2015.

  13. Oxygen vacancy in N-doped Cu2O crystals:A density functional theory study

    Institute of Scientific and Technical Information of China (English)

    Li Min; Zhang Jun-Ying; Zhang Yue; Wang Tian-Min

    2012-01-01

    The N-doping effects on the electronic properties of Cu2O crystals are investigated using density functional theory.The calculated results show that N-doped Cu2O with or without oxygen vacancy exhibits different modifications of electronic band structure.In N anion-doped Cu2O,some N 2p states overlap and mix with the O 2p valence band,leading to a slight narrowing of band gap compared with the undoped Cu2O.However,it is found that the coexistence of both N impurity and oxygen vacancy contributes to band gap widening which may account for the experimentally observed optical band gap widening by N doping.

  14. Leveraging zinc interstitials and oxygen vacancies for sensitive biomolecule detection through selective surface functionalization

    Science.gov (United States)

    Radha Shanmugam, Nandhinee; Muthukumar, Sriram; Chaudhry, Shajee; Prasad, Shalini

    2015-03-01

    In this study, functionally engineered EIS technique was implemented to investigate the influence of surface functionalization on sensitivity of biomolecule detection using nanostructured ZnO platform. Organic molecules with thiol and carboxylic functional groups were chosen to control biomolecule immobilization on zinc and oxygen-terminated 2D planar and 1D nanostructured ZnO surfaces. The amount of functionalization and its influence on charge perturbations at the ZnO-electrolyte interface were studied using fluorescence and EIS measurements. We observed the dependence of charge transfer on both the polarity of platform and concentration of cross-linker molecules. Such selectively modified surfaces were used for detection of cortisol, a major stress indicator. Results demonstrated preferential binding of thiol groups to Zn terminations and thus leveraging ZnO interstitials increases the sensitivity of detection over larger dynamic range with detection limit at 10fg/mL.

  15. Durability to oxygen reactive ion etching enhanced by addition of synthesized bis(trimethylsilyl)phenyl-containing (meth)acrylates in ultraviolet nanoimprint lithography

    Science.gov (United States)

    Ito, Shunya; Sato, Hiroki; Tasaki, Yuhei; Watanuki, Kimihito; Nemoto, Nobukatsu; Nakagawa, Masaru

    2016-06-01

    We investigated the selection of bis(trimethylsilyl)phenyl-containing (meth)acrylates as additives to improve the durability to oxygen reactive ion etching (O2 RIE) of sub-50 nm imprint resist patterns suitable for bubble-defect-free UV nanoimprinting with a readily condensable gas. 2,5-Bis(2-acryloyloxyethoxy)-1,4-bis(trimethylsilyl)benzene, which has a diacrylate chemical structure similar to that of glycerol 1,3-diglycerolate diacrylate used as a base monomer, and 3-(2-methacryloyloxyethoxy)-1-(hydroxylethoxy)-2-propoxy-3,5-bis(trimethylsilyl)benzene, which has a hydroxy group similar to the base monomer, were synthesized taking into consideration the Ohnishi and ring parameters, and the oxidization of the trimethylsilyl moiety to inorganic species during O2 RIE. The addition of the latter liquid additive to the base monomer decreased etching rate owing to the good miscibility of the additive in the base monomer, while the addition of the former crystalline additive caused phase separation after UV nanoimprinting. The latter additive worked as a compatibilizer to the former additive, which is preferred for etching durability improvement. The coexistence of the additives enabled the fabrication of a 45 nm line-and-space resist pattern by UV nanoimprinting, and its residual layer could be removed by O2 RIE.

  16. Hypoxia-inducible factor-1α activation improves renal oxygenation and mitochondrial function in early chronic kidney disease.

    Science.gov (United States)

    Thomas, Joanna L; Pham, Hai; Li, Ying; Hall, Elanore; Perkins, Guy A; Ali, Sameh S; Patel, Hemal H; Singh, Prabhleen

    2017-08-01

    The pathophysiology of chronic kidney disease (CKD) is driven by alterations in surviving nephrons to sustain renal function with ongoing nephron loss. Oxygen supply-demand mismatch, due to hemodynamic adaptations, with resultant hypoxia, plays an important role in the pathophysiology in early CKD. We sought to investigate the underlying mechanisms of this mismatch. We utilized the subtotal nephrectomy (STN) model of CKD to investigate the alterations in renal oxygenation linked to sodium (Na) transport and mitochondrial function in the surviving nephrons. Oxygen delivery was significantly reduced in STN kidneys because of lower renal blood flow. Fractional oxygen extraction was significantly higher in STN. Tubular Na reabsorption was significantly lower per mole of oxygen consumed in STN. We hypothesized that decreased mitochondrial bioenergetic capacity may account for this and uncovered significant mitochondrial dysfunction in the early STN kidney: higher oxidative metabolism without an attendant increase in ATP levels, elevated superoxide levels, and alterations in mitochondrial morphology. We further investigated the effect of activation of hypoxia-inducible factor-1α (HIF-1α), a master regulator of cellular hypoxia response. We observed significant improvement in renal blood flow, glomerular filtration rate, and tubular Na reabsorption per mole of oxygen consumed with HIF-1α activation. Importantly, HIF-1α activation significantly lowered mitochondrial oxygen consumption and superoxide production and increased mitochondrial volume density. In conclusion, we report significant impairment of renal oxygenation and mitochondrial function at the early stages of CKD and demonstrate the beneficial role of HIF-1α activation on renal function and metabolism.

  17. A fixed point approach to the stability of an additive cubic functional equation in paranormed spaces

    Directory of Open Access Journals (Sweden)

    K. Ravi

    2014-03-01

    Full Text Available In this paper, using fixed point method we prove the generalized Hyers Ulam Rassias stability of the additive cubic functional equationf(x-ky=k2[f(x+y+ f(x-y]+2(1- k2f(x for fixed integers k, with k≠0,±1 in paranormed spaces.

  18. Carob flour and sugar beet fiber as functional additives in bread

    Directory of Open Access Journals (Sweden)

    Šoronja-Simović Dragana M.

    2016-01-01

    Full Text Available The effect of functional additives (carob flour and sugar beet fiber on empirical rheological dough performance and bread quality was examined. Also the microbiological quality of bread was investigated during 16 days of storage. The study included 5 samples: control (CON, with preservative calcium propionate (CONP, with carob flour (CON-CAR, with sugar beet fiber (CON-SBF and with a combination of carob flour and sugar beet fibers (CON-SBF-CAR. Samples with functional additives had a higher water holding capacity (2-10% and extended dough development time due to the presence of dietary fiber. Dough resistance of these samples was significantly increased, especially in CON-CAR, in which the time of final fermentation is remarkably prolonged (20% in comparison to CON. The addition of the functional ingredients (due to hydration properties of dietary fiber improved texture and sensory characteristics of bread. In sample CON-SBF crumb firmness was significantly reduced (by 70% while elasticity was increased by 25% compared to CON. Positive effect of addition of sugar beet fiber was proved by improving the elasticity of the crumb and finer crumb structure (sample CON-SBF in comparison with the addition of carob flour (sample CON-CAR. In bread sample with carob flour there was no microbiological contamination for 16 days of examination, which confirms the fact that carob flour can be used as a natural preservative.

  19. Effect of Ti addition to Pt/C catalyst on methanol electro-oxidation and oxygen electro-reduction reactions

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Min Ku; McGinn, Paul J. [Department of Chemical and Biomolecular Eng., University of Notre Dame, 178 Fitzpatrick, Notre Dame, IN 46556 (United States)

    2010-05-01

    Carbon supported binary Pt-Ti alloys were investigated for application in methanol electro-oxidation (MOR) and oxygen electro-reduction reactions (ORR). Various compositions of Pt{sub 100-x}Ti{sub x}/C (x = 0, 25, 50, and 75) catalysts were synthesized by sequential impregnation of Pt and Ti followed by annealing at 900 C for 30 min under H{sub 2}/Ar flow. X-ray diffraction results showed formation of the Pt{sub 3}Ti intermetallic phase in Pt{sub 50}Ti{sub 50} and Pt{sub 25}Ti{sub 75} catalysts after annealing at 900 C. The Pt{sub 50}Ti{sub 50}/C-900 and Pt{sub 25}Ti{sub 75}/C-900 catalysts (the '-900' designation indicates the catalyst was annealed at 900 C) exhibited 103% (87.4mA m g{sub Pt}{sup -1}) and 198% (128mA m g{sub Pt}{sup -1}) higher MOR activity, respectively, than in the Pt/C-900 catalyst (43.0mA m g{sub Pt}{sup -1}) at 0.7 V (vs. reversible hydrogen electrode (RHE)). These two catalysts also showed high ORR activity. From a specific activity basis, the Pt{sub 50}Ti{sub 50}/C-900 and Pt{sub 25}Ti{sub 75}/C-900 catalysts exhibited 32.3and30.2{mu} A c m{sub Pt}{sup -2}, respectively, which were 171 and 154% higher than the 11.9{mu} A c m{sub Pt}{sup -2} value of the Pt/C catalyst at 0.8 V (vs. RHE). Methanol-tolerant ORR activity was also investigated, but in the presence of methanol, the Pt{sub 50}Ti{sub 50}/C-900 and Pt{sub 25}Ti{sub 75}/C-900 catalysts both exhibited poor ORR activity. (author)

  20. Terrestrial exposure of oilfield flowline additives diminish soil structural stability and remediative microbial function

    Energy Technology Data Exchange (ETDEWEB)

    George, S.J.; Sherbone, J.; Hinz, C. [Centre for Land Rehabilitation, School of Earth and Environment, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia); Tibbett, M., E-mail: m.tibbett@cranfield.ac.uk [Centre for Land Rehabilitation, School of Earth and Environment, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia)

    2011-10-15

    Onshore oil production pipelines are major installations in the petroleum industry, stretching many thousands of kilometres worldwide which also contain flowline additives. The current study focuses on the effect of the flowline additives on soil physico-chemical and biological properties and quantified the impact using resilience and resistance indices. Our findings are the first to highlight deleterious effect of flowline additives by altering some fundamental soil properties, including a complete loss of structural integrity of the impacted soil and a reduced capacity to degrade hydrocarbons mainly due to: (i) phosphonate salts (in scale inhibitor) prevented accumulation of scale in pipelines but also disrupted soil physical structure; (ii) glutaraldehyde (in biocides) which repressed microbial activity in the pipeline and reduced hydrocarbon degradation in soil upon environmental exposure; (iii) the combinatory effects of these two chemicals synergistically caused severe soil structural collapse and disruption of microbial degradation of petroleum hydrocarbons. - Highlights: > Effects of flowline additives on soil structure and microbial function highlighted. > Phosphonate salts (in scale inhibitor) were found to disrupt soil physical structure. > Glutaraldehyde (in biocides) caused significant reduction of hydrocarbon degradation in soil. > Flowline additive chemicals synergistically affects soil structure and remediative microbial function. - Scale inhibitor and biocide oilfield flowline additives interactively affect soil physical and microbial properties

  1. Dental indications for the instrumental functional analysis in additional consideration of health-economic aspects

    Directory of Open Access Journals (Sweden)

    Willich, Stefan N.

    2010-01-01

    Full Text Available Background: Besides clinical and radiological examination instrumental functional analyses are performed as diagnostic procedures for craniomandibular dysfunctions. Instrumental functional analyses cause substantial costs and shows a considerable variability between individual dentist practices. Objectives: On the basis of published scientific evidence the validity of the instrumental functional analysis for the diagnosis of craniomandibular dysfunctions compared to clinical diagnostic procedures; the difference of the various forms of the instrumental functional analysis; the existence of a dependency on additional other factors and the need for further research are determined in this report. In addition, the cost effectiveness of the instrumental functional analysis is analysed in a health-policy context, and social, legal and ethical aspects are considered. Methods: A literature search is performed in over 27 databases and by hand. Relevant companies and institutions are contacted concerning unpublished studies. The inclusion criteria for publications are (i diagnostic studies with the indication “craniomandibular malfunction”, (ii a comparison between clinical and instrumental functional analysis, (iii publications since 1990, (iv publications in English or German. The identified literature is evaluated by two scientists regarding the relevance of content and methodical quality.Results: The systematic database search resulted in 962 hits. 187 medical and economic complete publications are evaluated. Since the evaluated studies are not relevant enough to answer the medical or health economic questions no study is included. Discussion: The inconsistent terminology concerning craniomandibular dysfunctions and instrumental functional analyses results in a broad literature search in databases and an extensive search by hand. Since no relevant results concerning the validity of the instrumental functional analysis in comparison to the clinical

  2. Dental indications for the instrumental functional analysis in additional consideration of health-economic aspects

    Science.gov (United States)

    Tinnemann, Peter; Stöber, Yvonne; Roll, Stephanie; Vauth, Christoph; Willich, Stefan N.; Greiner, Wolfgang

    2010-01-01

    Background Besides clinical and radiological examination instrumental functional analyses are performed as diagnostic procedures for craniomandibular dysfunctions. Instrumental functional analyses cause substantial costs and shows a considerable variability between individual dentist practices. Objectives On the basis of published scientific evidence the validity of the instrumental functional analysis for the diagnosis of craniomandibular dysfunctions compared to clinical diagnostic procedures; the difference of the various forms of the instrumental functional analysis; the existence of a dependency on additional other factors and the need for further research are determined in this report. In addition, the cost effectiveness of the instrumental functional analysis is analysed in a health-policy context, and social, legal and ethical aspects are considered. Methods A literature search is performed in over 27 databases and by hand. Relevant companies and institutions are contacted concerning unpublished studies. The inclusion criteria for publications are (i) diagnostic studies with the indication “craniomandibular malfunction”, (ii) a comparison between clinical and instrumental functional analysis, (iii) publications since 1990, (iv) publications in English or German. The identified literature is evaluated by two scientists regarding the relevance of content and methodical quality. Results The systematic database search resulted in 962 hits. 187 medical and economic complete publications are evaluated. Since the evaluated studies are not relevant enough to answer the medical or health economic questions no study is included. Discussion The inconsistent terminology concerning craniomandibular dysfunctions and instrumental functional analyses results in a broad literature search in databases and an extensive search by hand. Since no relevant results concerning the validity of the instrumental functional analysis in comparison to the clinical functional analysis

  3. Tunable Oxygen Functional Groups as Electrocatalysts on Graphite Felt Surfaces for All-Vanadium Flow Batteries.

    Science.gov (United States)

    Estevez, Luis; Reed, David; Nie, Zimin; Schwarz, Ashleigh M; Nandasiri, Manjula I; Kizewski, James P; Wang, Wei; Thomsen, Edwin; Liu, Jun; Zhang, Ji-Guang; Sprenkle, Vincent; Li, Bin

    2016-06-22

    A dual oxidative approach using O2 plasma followed by treatment with H2 O2 to impart oxygen functional groups onto the surface of a graphite felt electrode. When used as electrodes for an all-vanadium redox flow battery (VRB) system, the energy efficiency of the cell is enhanced by 8.2 % at a current density of 150 mA cm(-2) compared with one oxidized by thermal treatment in air. More importantly, by varying the oxidative techniques, the amount and type of oxygen groups was tailored and their effects were elucidated. It was found that O-C=O groups improve the cells performance whereas the C-O and C=O groups degrade it. The reason for the increased performance was found to be a reduction in the cell overpotential after functionalization of the graphite felt electrode. This work reveals a route for functionalizing carbon electrodes to improve the performance of VRB cells. This approach can lower the cost of VRB cells and pave the way for more commercially viable stationary energy storage systems that can be used for intermittent renewable energy storage.

  4. Life Cycle Assessment of Functionally Enhanced Polymers-Engineered Nanomaterials or Conventional Additives?

    DEFF Research Database (Denmark)

    Miseljic, Mirko; Olsen, Stig Irving

    2016-01-01

    Engineered nanomaterials, where at least one dimension is within 1-100 nm, are produced and used in many consumer products, with the purpose of enhancing specific material properties (e. g., in plastic products). Conventionally, organic and inorganic non-engineered nanomaterial additives are also...... insulation panels for buildings). Antibacterial, ultraviolet ray protection or flame retardancy properties of these products have been improved through the addition of either Ag, ZnO or Mg(OH)(2) engineered nanomaterials, or conventional organic/inorganic polymer additives. The study also presents new...... that in all cases the products with engineered nanomaterials generate higher potential environmental impacts than products with conventional additives. However, when considering the improved material functionality results differ more. The polyvinylchloride-wood outdoor flooring and polystyrene insulation...

  5. The Dual Role of Oxygen Functions in Coal Pretreatment and Liquefaction: Crosslinking and Cleavage Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Michael Serio; Erik Kroo; Sylvie Charpenay; Peter Solomon

    1993-09-30

    The overall objective of this project was to elucidate and model the dual role of oxygen functions in thermal pretreatment and liquefaction of low rank coals through the application of analytical techniques and theoretical models. The project was an integrated study of model polymers representative of coal structures, raw coals of primarily low rank, and selectively modified coals in order to provide specific information relevant to the reactions of real coals. The investigations included liquefaction experiments in microautoclave reactors, along with extensive analysis of intermediate solid, liquid and gaseous products. Attempts were made to incorporate the results of experiments on the different systems into a liquefaction model.

  6. Catalytic selective oxidation or oxidative functionalization of methane and ethane to organic oxygenates

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Selective oxidation or oxidative functionalization of methane and ethane by both homogeneous and heterogeneous catalysis is presented concerning: (1) selective oxidation of methane and ethane to organic oxygenates by hydrogen peroxide in a water medium in the presence of homogeneous osmium catalysts, (2) selective oxidation of methane to formaldehyde over highly dispersed iron and copper heterogeneous catalysts, (3) selective oxidation of ethane to acetaldehyde and formaldehyde over supported molybdenum catalysts, and (4) oxidative carbonylation of methane to methyl acetate over heterogeneous catalysts containing dual sites of rhodium and iron.

  7. Combinatorial Density Functional Theory-Based Screening of Surface Alloys for the Oxygen Reduction Reaction

    DEFF Research Database (Denmark)

    Greeley, Jeffrey Philip; Nørskov, Jens Kehlet

    2009-01-01

    A density functional theory (DFT)-based, combinatorial search for improved oxygen reduction reaction (ORR) catalysts is presented. A descriptor-based approach to estimate the ORR activity of binary surface alloys, wherein alloying occurs only in the surface layer, is described, and rigorous......, potential-dependent computational tests of the stability of these alloys in aqueous, acidic environments are presented. These activity and stability criteria are applied to a database of DFT calculations on nearly 750 binary transition metal surface alloys; of these, many are predicted to be active...

  8. Density functional theory calculations on oxygen adsorption on the Cu{sub 2}O surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Xiaohu [College of Physics and Electrical Engineering, Anyang Normal University, Anyang, Henan 455000 (China); State Key laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001 (China); Zhang, Xuemei [College of Physics and Electrical Engineering, Anyang Normal University, Anyang, Henan 455000 (China); Tian, Xinxin [State Key laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001 (China); Wang, Shengguang, E-mail: shengguang.wang@gmail.com [State Key laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001 (China); Synfuels China Co., Ltd., Huairou, Beijing 101407 (China); Feng, Gang, E-mail: fengg.sshy@sinopec.com [State Key laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001 (China); Shanghai Research Institute of Petrochemical Technology SINOPEC, Shanghai 201208 (China)

    2015-01-01

    Graphical abstract: - Highlights: • Atomic oxygen adsorption on Cu{sub 2}O(110) and Cu{sub 2}O(100) induces surface reconstruction. • Atomic O and molecular O{sub 2} adsorption on the Cu{sub 2}O(100) surface is stronger than on the Cu{sub 2}O(111) surface. • Dissociative adsorption was found to be energetically favorable. • Atomic O and molecular O{sub 2} adsorption on the Cu{sub 2}O(111) surface induces magnetism. - Abstract: In order to understand various surface properties such as corrosion and potential catalytic activity of Cu{sub 2}O surfaces in the presence of environmental gases, we report here spin-polarized density functional theory calculations of the adsorptions of atomic and molecular oxygen on three surface Cu{sub 2}O facets. Atomic oxygen adsorbs at the hollow site formed with copper atoms of Cu{sub 2}O(111), while its adsorption on the Cu{sub 2}O(110) and Cu{sub 2}O(100) induces surface reconstruction. Molecular oxygen adsorbs on one coordinated unsaturated surface copper atom and two coordinated saturated copper atoms of Cu{sub 2}O(111), on the top of two surface copper atoms of Cu{sub 2}O(110), and on four surface copper atoms on Cu{sub 2}O(100). It was found that atomic O and molecular O{sub 2} adsorption on the Cu{sub 2}O(100) surface is stronger than on the Cu{sub 2}O(111) surface. Atomic O and molecular O{sub 2} adsorption on the surface of Cu{sub 2}O(111) induces magnetism. This is different from other systems previously known to exhibit point defect ferromagnetism. On all three surfaces, dissociative adsorption was found to be energetically favorable.

  9. Determination of mass diffusion coefficients of oxygenated fuel additives in air using digital real-time holographic interferometry

    Science.gov (United States)

    He, Maogang; Guo, Ying; Zhong, Qiu; Zhang, Ying

    2009-02-01

    In this work, an experimental system based on digital real-time holographic interferometry for measuring the mass diffusion coefficients of fluid is introduced. The method of processing interference fringe hologram is also introduced thoroughly. By uncertainties analysis and experimental verification, the accuracy of this system is validated. The experimental uncertainties in temperature and mass diffusion coefficient are estimated to be no greater than ± 0.16 K and ± 0.2 %, respectively. On this basis, the mass diffusion coefficients of three fuel additives, diethyl 1,6-hexanedioate (diethyl adipate, DEA), dimethyl carbonate (DMC) and diethyl carbonate (DEC) in air were measured at T = (278.15 to 338.15) K under atmospheric pressure, and polynomial was fitted by the experimental data.

  10. Additional brain functional network in adults with attention-deficit/hyperactivity disorder: a phase synchrony analysis.

    Directory of Open Access Journals (Sweden)

    Dongchuan Yu

    Full Text Available We develop a method to construct a new type of functional networks by the usage of phase synchrony degree that is different from the widely used Pearson's correlation approach. By a series of very strict statistical tests, we found that there is an additional network in attention-deficit/hyperactivity disorder (ADHD subjects, superimposing the original (normal brain functional network corresponding to healthy controls. The additional network leads to the increase in clustering coefficient, cost, local efficiency, and global efficiency. Our findings are inconsistent with many previous researches (using the Pearson's correlation approach revealing both increased and decreased functional connections between brain regions and many reports revealing that the brain functional networks of ADHD patients have slow information flow and low global efficiency. We also confirm that the additional network in ADHD subjects contains 6 communities, and three of them are associated with emotional control, sensory information integration, and motor control, respectively. Furthermore, we find that there is a pathway connecting the left insula and left anterior cingular gyrus via the frontal gyrus and putamen in the additional network in ADHD subjects. This implies that due to the pathway connecting brain regions in the salience network, the ADHD patients are more sensitive to external stimuli or internal thoughts and are easier to switch to the executive network and hence harder to inhibit. For clinical diagnostic purposes, we apply the k-means clustering method to distinguish ADHD patients with healthy controls at the individual subject level, and obtain a meaningful diagnostic result. More interestingly, we find that the suggested technique using phase synchrony degree to construct functional networks may obtain higher classification accuracy than the method using the Pearson's correlation coefficient.

  11. The Use of Additive Manufacturing for Fabrication of Multi-Function Small Satellite Structures

    Energy Technology Data Exchange (ETDEWEB)

    Horais, Brian J [ORNL; Love, Lonnie J [ORNL; Dehoff, Ryan R [ORNL

    2013-01-01

    The use of small satellites in constellations is limited only by the growing functionality of smallsats themselves. Additive manufacturing provides exciting new design opportunities for development of multifunction CubeSat structures that integrate such functions as propulsion and thermal control into the satellite structures themselves. Manufacturing of these complex multifunction structures is now possible in lightweight, high strength, materials such as titanium by using existing electron beam melting additive manufacturing processes. However, the use of today's additive manufacturing capabilities is often cost-prohibitive for small companies due to the large capital investments required. To alleviate this impediment the U.S. Department of Energy has established a Manufacturing Demonstration Facility (MDF) at their Oak Ridge National Laboratory (ORNL) in Tennessee that provides industry access to a broad range of energy-efficient additive manufacturing equipment for collaborative use by both small and large organizations. This paper presents a notional CubeSat multifunction design that integrates the propulsion system into a three-unit (3U) CubeSat structure. The full-scale structure has been designed and fabricated at the ORNL MDF. The use of additive manufacturing for spacecraft fabrication is opening up many new possibilities in design and fabrication capabilities for what had previously been impossible structures to fabricate.

  12. Pulmonary functional MRI:an animal model study of oxygen-enhanced ventilation combined with Gd-DTPA-enhanced perfusion

    Institute of Scientific and Technical Information of China (English)

    杨健; 万明习; 郭佑民

    2004-01-01

    Background The assessment of regional pulmonary ventilation and perfusion is essential for the evaluation of a variety of lung disorders. Pulmonary ventilation MRI using inhaled oxygen as a contrast medium can be obtained with a clinical MR scanner, without additional equipment, and has been demonstrated to be a feasible means of assessing ventilation in animal models and some clinical patients. However, few studies have reported on MR ventilation-perfusion imaging. In this study, we evaluated the usefulness of oxygen-enhanced ventilation in combination with first-pass Gd-DTPA-enhanced perfusion MRI in a canine model of pulmonary embolism and airway obstruction.Methods Peripheral pulmonary embolisms were produced in eight dogs by intravenous injection of gelfoam strips at the pulmonary segmental arterial level, and airway obstructions were created in five of the dogs by inserting a self-designed balloon catheter into a secondary bronchus. Oxygen-enhanced MR ventilation images were produced by subtracting images from before and after inhalation of pure oxygen. Pulmonary perfusion MR images were acquired with a dynamic three-dimensional fast gradient-echo sequence. MR ventilation and perfusion images were read and contrasted with results from general examinations of pathological anatomy, ventilation-perfusion scintigraphy, and pulmonary angiography. Results Regions identified as having airway obstructions matched using both MR ventilation and perfusion imaging, but regions of pulmonary embolisms were mismatched. The area of airway obstruction defects was smaller using MR ventilation imagery than that using ventilation scintigraphy. Abnormal perfusion regions due to pulmonary embolisms were divided into defective regions and reduced regions based on the time course of signal intensity changes. In the diagnosis of pulmonary embolisms with the technique of ventilation and perfusion MRI, sensitivity and specificity were 75.0% and 98.1%, respectively, and the diagnostic

  13. Compositions, Functions, and Testing of Friction Brake Materials and Their Additives

    Energy Technology Data Exchange (ETDEWEB)

    Blau, PJ

    2001-10-22

    The purpose of this report is to present a survey of commercial brake materials and additives, and to indicate their typical properties and functions, especially as regards their use in heavy trucks. Most truck pad and shoe materials described here were designed to wear against cast iron. Brake material test methods are also briefly described. This report does not address issues associated with the fabrication and manufacturing of brake materials. Since there are literally thousands of brake material additives, and their combinations are nearly limitless, it is impractical to list them all here. Rather, an attempt has been made to capture the primary constituents and their functions. An Appendix contains thermo-physical properties of some current and potential brake materials.

  14. Effect of Addition of Cereal Based Beta-glucan on Technological and Functional Properties of Foods

    Directory of Open Access Journals (Sweden)

    Nihal Şimşekli

    2015-01-01

    Full Text Available Nowadays usage of dietary fibers in foods has been increasing duo to revealing of health benefits. Beta-glucans found especially in oats and barley, are polysaccharide and source of water-soluble dietary fiber. Positive effects of beta-glucans like healing coronary-heart disease, lowering blood cholesterol level, balancing blood sugar level and preventing obesity, made beta-glucans widespread functional food components for producing various foods. In addition to beneficial physiological effects of beta-glucans, they texturize, gelatinize, emulsify and stabilize the foods. They increase viscosity, replace fat and enhance rheological properties in cereal, meat and dairy products. They are also used to produce packing material depending on their mechanical properties and molecular weights. In this review, effects of addition of cereal based beta-glucans on technological and functional properties of various foods are revealed based on previous studies.

  15. Taurine Supplementation Improves Functional Capacity, Myocardial Oxygen Consumption, and Electrical Activity in Heart Failure.

    Science.gov (United States)

    Ahmadian, Mehdi; Dabidi Roshan, Valiollah; Ashourpore, Eadeh

    2017-07-04

    Taurine is an amino acid found abundantly in the heart in very high concentrations. It is assumed that taurine contributes to several physiological functions of mammalian cells, such as osmoregulation, anti-inflammation, membrane stabilization, ion transport modulation, and regulation of oxidative stress and mitochondrial protein synthesis. The objective of the current study was to evaluate the effectiveness of taurine supplementation on functional capacity, myocardial oxygen consumption, and electrical activity in patients with heart failure. In a double-blind and randomly designed study, 16 patients with heart failure were assigned to two groups: taurine (TG, n = 8) and placebo (PG, n = 8). TG received 500-mg taurine supplementation three times per day for two weeks. Significant decrease in the values of Q-T segments (p taurine concentration, T wave, Q-T segment, physical capacities, and lower values of cardiovascular capacities were detected post-supplementation in TG as compared with PG (all p values Taurine significantly enhanced the physical function and significantly reduced the cardiovascular function parameters following exercise. Our results also suggest that the short-term taurine supplementation is an effective strategy for improving some selected hemodynamic parameters in heart failure patients. Together, these findings support the view that taurine improves cardiac function and functional capacity in patients with heart failure. This idea warrants further study.

  16. In vitro function of random donor platelets stored for 7 days in composol platelet additive solution

    Directory of Open Access Journals (Sweden)

    Gupta Ashish

    2011-01-01

    Full Text Available Background and Aim: Platelets are routinely isolated from whole blood and stored in plasma for 5 days. The present study was done to assess the in vitro function of random donor platelets stored for 7 days in composol platelet additive solution at 22°C. Materials and Methods: The study sample included 30 blood donors of both sex in State Blood Bank, CSM Medical University, Lucknow. Random donor platelets were prepared by platelet rich plasma method. Whole blood (350 ml was collected in anticoagulant Citrate Phosphate Dextrose Adenine triple blood bags. Random donor platelets were stored for 7 days at 22°C in platelet incubators and agitators, with and without additive solution. Results: Platelet swirling was present in all the units at 22°C on day 7, with no evidence of bacterial contamination. Comparison of the mean values of platelet count, platelet factor 3, lactate dehydrogenase, pH, glucose and platelet aggregation showed no significant difference in additive solution, whereas platelet factor 3, glucose and platelet aggregation showed significant difference (P < 0.001 on day 7 without additive solution at 22°C. Conclusion: Our study infers that platelet viability and aggregation were best maintained within normal levels on day 7 of storage in platelet additive solution at 22°C. Thus, we may conclude that in vitro storage of random donor platelets with an extended shelf life of 7 days using platelet additive solution may be advocated to improve the inventory of platelets.

  17. Characterisation of the influence function non-additivities for a 1024-actuator MEMS deformable mirror

    CERN Document Server

    Blain, Celia; Bradley, Colin; Guyon, Olivier; Vogel, Curtis

    2010-01-01

    In order to evaluate the potential of MEMS deformable mirrors for open-loop applications, a complete calibration process was performed on a 1024-actuator mirror. The mirror must be perfectly calibrated to obtain deterministic membrane deflection. The actuator's stroke-voltage relationship and the effect of the non- additivity of the influence functions are studied and finally integrated in an open-loop control process. This experiment aimed at minimizing the residual error obtained in open-loop control.

  18. Orthogonal Stability of an Additive-quartic Functional Equation in Non-Archimedean Spaces

    Directory of Open Access Journals (Sweden)

    Hassan Azadi Kenary

    2012-04-01

    Full Text Available Using fixed point method, we prove the Hyers-Ulam stability of the orthogonally additive-quartic functional equation f(2x+y+ f(2x-y=4 f(x+y+ 4 f(x-y + 10 f(x + 14f(-x - 3 f(y-3f(-y for all $x, y$ with $xperp y$, in non-Archimedean Banach spaces. Here $perp$ is the orthogonality in the sense of Rätz.

  19. An experimental study of the partitioning of trace elements between rutile and silicate melt as a function of oxygen fugacity

    Directory of Open Access Journals (Sweden)

    GUILHERME MALLMANN

    2014-12-01

    Full Text Available Subduction zone or arc magmas are known to display a characteristic depletion of High Field Strength Elements (HFSE relative to other similarly incompatible elements, which can be attributed to the presence of the accessory mineral rutile (TiO2 in the residual slab. Here we show that the partitioning behavior of vanadium between rutile and silicate melt varies from incompatible (∼0.1 to compatible (∼18 as a function of oxygen fugacity. We also confirm that the HFSE are compatible in rutile, with D(Ta> D(Nb>> (D(Hf>/∼ D(Zr, but that the level of compatibility is strongly dependent on melt composition, with partition coefficients increasing about one order of magnitude with increasing melt polymerization (or decreasing basicity. Our partitioning results also indicate that residual rutile may fractionate U from Th due to the contrasting (over 2 orders of magnitude partitioning between these two elements. We confirm that, in addition to the HFSE, Cr, Cu, Zn and W are compatible in rutile at all oxygen fugacity conditions.

  20. Alumina Matrix Composites with Non-Oxide Nanoparticle Addition and Enhanced Functionalities

    Directory of Open Access Journals (Sweden)

    Dušan Galusek

    2015-01-01

    Full Text Available The addition of SiC or TiC nanoparticles to polycrystalline alumina matrix has long been known as an efficient way of improving the mechanical properties of alumina-based ceramics, especially strength, creep, and wear resistance. Recently, new types of nano-additives, such as carbon nanotubes (CNT, carbon nanofibers (CNF, and graphene sheets have been studied in order not only to improve the mechanical properties, but also to prepare materials with added functionalities, such as thermal and electrical conductivity. This paper provides a concise review of several types of alumina-based nanocomposites, evaluating the efficiency of various preparation methods and additives in terms of their influence on the properties of composites.

  1. A comparative study of atomic oxygen adsorption at Pd surfaces from Density Functional Theory

    Science.gov (United States)

    Bukas, Vanessa J.; Reuter, Karsten

    2017-04-01

    Based on density functional theory, we present a detailed investigation into the on-surface adsorption of atomic oxygen at all three low-index Pd facets in the low-coverage regime. Relying on one consistent computational framework allows for a systematic comparison with respect to surface symmetry, while discerning trends in the adsorption geometries, energies, work functions, and electron densities. We overall find a persisting degree of O-Pd hybridization that is accompanied by minimal charge transfer from the substrate to the adsorbate, thereby resulting in comparable binding energies and diffusion barriers at the three surfaces. Small differences in reactivity are nevertheless reflected in subtle variations of the underlying electronic structure which do not, however, follow the expected order according to atom packing density.

  2. Functionality of albumin-derived perfluorocarbon-based artificial oxygen carriers in the Langendorff-heart (†).

    Science.gov (United States)

    Wrobeln, Anna; Schlüter, Klaus D; Linders, Jürgen; Zähres, Manfred; Mayer, Christian; Kirsch, Michael; Ferenz, Katja B

    2017-06-01

    The aim of this study was to prove whether albumin-derived perfluorocarbon-based nanoparticles (capsules) can operate as a novel artificial oxygen carrier in a rat Langendorff-heart perfusion model. Hearts perfused with capsules showed increased left ventricular pressure and rate pressure product compared to hearts perfused with pure Krebs-Henseleit (KH)-buffer. The capsules prevented the myocardium from functional fail when in their absence a noxious ischemia was observed. Capsules did not change rheological properties of KH-buffer and could repeatedly reload with oxygen. This albumin-derived perfluorocarbon-based artificial oxygen carrier preserved the function of rat hearts due to the transport of oxygen in a satisfactory manner. Because of these positive results, the functionality of the applied capsules should be verified in living animals.

  3. The luminescent carbon nanoparticles with controllable oxygen-related functional groups prepared by pulsed laser ablation in water

    Science.gov (United States)

    Zhang, Jun; Gan, Zhixing; Hu, Guang; Tang, Yalu; Zhou, Lei; Jiang, Qingsong; Cui, Yu

    2016-10-01

    Fluorescent carbon nanoparticles (CNPs) are obtained via pulsed laser ablation (PLA) of a carbon target immersed in deionized water. By tuning the laser power for PLA, the density of oxygen-related functional groups at the surfaces is controllable. While the crystallinities, sizes, morphologies and defects are nearly retained, the prepared CNPs show blue fluorescence under UV exposure and the photoluminescence (PL) intensities of the C-dots are dependent on the oxygen contents. Accordingly, the PL is attributed to the transition of electronic states caused by oxygen-related functional groups. This work sheds new light on the PL mechanism of CNPs and proposes an efficient way to prepare CNPs with controllable oxygen-related functional groups.

  4. FUNCTION FEED ADDITIVE OF CAROTE-NOID VEGETABLE RAW MATERIALS FOR POULTRY

    Directory of Open Access Journals (Sweden)

    Koshchayev A. G.

    2013-11-01

    Full Text Available The article is concerned with the use of functional feed additives from pumpkin fruits and alfalfa juice for the poultry industry. In the study of laying hen it has been found that the use of a feed additive in-creased pumpkin paste content in serum and egg yolk carotenoids is more than two times, and the concentration of vitamin A in these tissues increased slightly, not exceeding 20%. Livability and productivity of poultry increased and average expendable fodder per head per day decreased. Economic calculation showed that the use of pumpkin paste reduces the cost of production of eggs. The use of alfalfa juice coagulates in diets for broiler chickens resulted in an increase in the concentration of carotene in the liver by 22,7-46,8% relative to control. The juice addition also increased the content of vitamin A in the liver by 27.9%, increase the safety and efficiency of the bird. The authors draw certain conclusions from experiment results that the use of functional additives in poultry from the fruit of pumpkin and alfalfa juice is an alternative to synthetic vitamin preparations and produce a more environmentally friendly products

  5. Microplastic moves pollutants and additives to worms, reducing functions linked to health and biodiversity.

    Science.gov (United States)

    Browne, Mark Anthony; Niven, Stewart J; Galloway, Tamara S; Rowland, Steve J; Thompson, Richard C

    2013-12-02

    Inadequate products, waste management, and policy are struggling to prevent plastic waste from infiltrating ecosystems [1, 2]. Disintegration into smaller pieces means that the abundance of micrometer-sized plastic (microplastic) in habitats has increased [3] and outnumbers larger debris [2, 4]. When ingested by animals, plastic provides a feasible pathway to transfer attached pollutants and additive chemicals into their tissues [5-15]. Despite positive correlations between concentrations of ingested plastic and pollutants in tissues of animals, few, if any, controlled experiments have examined whether ingested plastic transfers pollutants and additives to animals. We exposed lugworms (Arenicola marina) to sand with 5% microplastic that was presorbed with pollutants (nonylphenol and phenanthrene) and additive chemicals (Triclosan and PBDE-47). Microplastic transferred pollutants and additive chemicals into gut tissues of lugworms, causing some biological effects, although clean sand transferred larger concentrations of pollutants into their tissues. Uptake of nonylphenol from PVC or sand reduced the ability of coelomocytes to remove pathogenic bacteria by >60%. Uptake of Triclosan from PVC diminished the ability of worms to engineer sediments and caused mortality, each by >55%, while PVC alone made worms >30% more susceptible to oxidative stress. As global microplastic contamination accelerates, our findings indicate that large concentrations of microplastic and additives can harm ecophysiological functions performed by organisms.

  6. GeoChip-based analysis of functional microbial communities in a bioreduced uranium-contaminated aquifer during reoxidation by oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Van Nostrand, J.D.; Wu, W.-M.; Wu, L.; Deng, Y.; Carley, J.; Carroll, S.; He, Z.; Gu, B.; Luo, J.; Criddle, C. S.; Watson, D. B.; Jardine, P. M.; Tiedje, J. M.; Hazen, T. C.; Zhou, J.

    2009-07-15

    A pilot-scale system was established for in situ biostimulation of U(VI) reduction by ethanol addition at the US Department of Energy's (DOE's) Field Research Center (Oak Ridge, TN). After achieving U(VI) reduction, stability of the bioreduced U(IV) was evaluated under conditions of (i) resting (no ethanol injection), (ii) reoxidation by introducing dissolved oxygen (DO), and (iii) reinjection of ethanol. GeoChip, a functional gene array with probes for N, S and C cycling, metal resistance and contaminant degradation genes, was used for monitoring groundwater microbial communities. High diversity of all major functional groups was observed during all experimental phases. The microbial community was extremely responsive to ethanol, showing a substantial change in community structure with increased gene number and diversity after ethanol injections resumed. While gene numbers showed considerable variations, the relative abundance (i.e. percentage of each gene category) of most gene groups changed little. During the reoxidation period, U(VI) increased, suggesting reoxidation of reduced U(IV). However, when introduction of DO was stopped, U(VI) reduction resumed and returned to pre-reoxidation levels. These findings suggest that the community in this system can be stimulated and that the ability to reduce U(VI) can be maintained by the addition of electron donors. This biostimulation approach may potentially offer an effective means for the bioremediation of U(VI)-contaminated sites.

  7. Box-modeling of bone and tooth phosphate oxygen isotope compositions as a function of environmental and physiological parameters.

    Science.gov (United States)

    Langlois, C; Simon, L; Lécuyer, Ch

    2003-12-01

    A time-dependent box model is developed to calculate oxygen isotope compositions of bone phosphate as a function of environmental and physiological parameters. Input and output oxygen fluxes related to body water and bone reservoirs are scaled to the body mass. The oxygen fluxes are evaluated by stoichiometric scaling to the calcium accretion and resorption rates, assuming a pure hydroxylapatite composition for the bone and tooth mineral. The model shows how the diet composition, body mass, ambient relative humidity and temperature may control the oxygen isotope composition of bone phosphate. The model also computes how bones and teeth record short-term variations in relative humidity, air temperature and delta18O of drinking water, depending on body mass. The documented diversity of oxygen isotope fractionation equations for vertebrates is accounted for by our model when for each specimen the physiological and diet parameters are adjusted in the living range of environmental conditions.

  8. Functionalizing Titanium Disilicide Nanonets with Cobalt Oxide and Palladium for Stable Li Oxygen Battery Operations.

    Science.gov (United States)

    Yao, Xiahui; Cheng, Qingmei; Xie, Jin; Dong, Qi; Wang, Dunwei

    2015-10-07

    Li oxygen (Li-O2) batteries promise high energy densities but suffer from challenges such as poor cycling lifetime and low round-trip efficiencies. Recently, the instability of carbon cathode support has been recognized to contribute significantly to the problems faced by Li-O2 batteries. One strategy to address the challenge is to replace carbon materials with carbon-free ones. Here, we present titanium silicide nanonets (TiSi2) as such a new material platform for this purpose. Because TiSi2 exhibits no oxygen reduction reaction (ORR) or oxygen evolution reaction (OER) activities, catalysts are required to promote discharge and recharge reactions at reduced overpotentials. Pd nanoparticles grown by atomic layer deposition (ALD) were observed to provide the bifunctionalities of ORR and OER. Their adhesion to TiSi2 nanonets, however, was found to be poor, leading to drastic performance decay due to Pd detachments and aggregation. The problem was solved by adding another layer of Co3O4, also prepared by ALD. Together, the Pd/Co3O4/TiSi2 combination affords the desired functionalities and stability. Li-O2 test cells that lasted more than 126 cycles were achieved. The reversible formation and decomposition of Li2O2 was verified by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), ferrocenium back-titration, and gas-chromatography and mass spectrometry (GC-MS). Our results provide a new material platform for detailed studies of Li-O2 operations for better understanding of the chemistries involved, which is expected to help pave the way toward practical Li-O2 battery realizations.

  9. The Effect of Patient-Specific Cerebral Oxygenation Monitoring on Postoperative Cognitive Function: A Multicenter Randomized Controlled Trial

    Science.gov (United States)

    Ellis, Lucy; Murphy, Gavin J; Culliford, Lucy; Dreyer, Lucy; Clayton, Gemma; Downes, Richard; Nicholson, Eamonn; Stoica, Serban; Reeves, Barnaby C

    2015-01-01

    Background Indices of global tissue oxygen delivery and utilization such as mixed venous oxygen saturation, serum lactate concentration, and arterial hematocrit are commonly used to determine the adequacy of tissue oxygenation during cardiopulmonary bypass (CPB). However, these global measures may not accurately reflect regional tissue oxygenation and ischemic organ injury remains a common and serious complication of CPB. Near-infrared spectroscopy (NIRS) is a noninvasive technology that measures regional tissue oxygenation. NIRS may be used alongside global measures to optimize regional perfusion and reduce organ injury. It may also be used as an indicator of the need for red blood cell transfusion in the presence of anemia and tissue hypoxia. However, the clinical benefits of using NIRS remain unclear and there is a lack of high-quality evidence demonstrating its efficacy and cost effectiveness. Objective The aim of the patient-specific cerebral oxygenation monitoring as part of an algorithm to reduce transfusion during heart valve surgery (PASPORT) trial is to determine whether the addition of NIRS to CPB management algorithms can prevent cognitive decline, postoperative organ injury, unnecessary transfusion, and reduce health care costs. Methods Adults aged 16 years or older undergoing valve or combined coronary artery bypass graft and valve surgery at one of three UK cardiac centers (Bristol, Hull, or Leicester) are randomly allocated in a 1:1 ratio to either a standard algorithm for optimizing tissue oxygenation during CPB that includes a fixed transfusion threshold, or a patient-specific algorithm that incorporates cerebral NIRS monitoring and a restrictive red blood cell transfusion threshold. Allocation concealment, Internet-based randomization stratified by operation type and recruiting center, and blinding of patients, ICU and ward care staff, and outcome assessors reduce the risk of bias. The primary outcomes are cognitive function 3 months after

  10. Nitric oxide and S-nitrosoglutathione function additively during plant immunity.

    Science.gov (United States)

    Yun, Byung-Wook; Skelly, Michael J; Yin, Minghui; Yu, Manda; Mun, Bong-Gyu; Lee, Sang-Uk; Hussain, Adil; Spoel, Steven H; Loake, Gary J

    2016-07-01

    Nitric oxide (NO) is emerging as a key regulator of diverse plant cellular processes. A major route for the transfer of NO bioactivity is S-nitrosylation, the addition of an NO moiety to a protein cysteine thiol forming an S-nitrosothiol (SNO). Total cellular levels of protein S-nitrosylation are controlled predominantly by S-nitrosoglutathione reductase 1 (GSNOR1) which turns over the natural NO donor, S-nitrosoglutathione (GSNO). In the absence of GSNOR1 function, GSNO accumulates, leading to dysregulation of total cellular S-nitrosylation. Here we show that endogenous NO accumulation in Arabidopsis, resulting from loss-of-function mutations in NO Overexpression 1 (NOX1), led to disabled Resistance (R) gene-mediated protection, basal resistance and defence against nonadapted pathogens. In nox1 plants both salicylic acid (SA) synthesis and signalling were suppressed, reducing SA-dependent defence gene expression. Significantly, expression of a GSNOR1 transgene complemented the SNO-dependent phenotypes of paraquat resistant 2-1 (par2-1) plants but not the NO-related characters of the nox1-1 line. Furthermore, atgsnor1-3 nox1-1 double mutants supported greater bacterial titres than either of the corresponding single mutants. Our findings imply that GSNO and NO, two pivotal redox signalling molecules, exhibit additive functions and, by extension, may have distinct or overlapping molecular targets during both immunity and development.

  11. Effect of hyperbaric oxygen on MMP9/2 expression and motor function in rats with spinal cord injury.

    Science.gov (United States)

    Hou, Ying-Nuo; Ding, Wen-Yuan; Shen, Yong; Yang, Da-Long; Wang, Lin-Feng; Zhang, Peng

    2015-01-01

    To study the effect of hyperbaric oxygen intervention on the microenvironment of nerve regeneration after spinal cord injury modeling and to explore the possible mechanism of nerve regeneration and functional recovery in rats with spinal cord injury. In 98 adult female SD rats, 90 successful models were obtained, which were divided into sham group, spinal cord injury group and hyperbaric oxygen group using randomized block method, 30/group. Spinal cord injury rat model was established in accordance with the modified Allen method. Motor function was assessed at the time points of before modeling, one day, three days, one week, two weeks, three weeks and four weeks after modeling respectively by BBB rating, inclined plane test and improved Tarlov score. At 3 days after modeling, apoptosis of neuronal cells in spinal cord injury region in experimental group was detected by TUNEL method; gene and protein expression of MMP9/2 in spinal cord injury and surrounding tissues was detected by RT-PCR and Western blot assay. At 4 weeks after modeling, histopathological morphological changes in spinal cord injury were observed by HE staining; fluorogold retrograde tracing was used to observe the regeneration and distribution of spinal cord nerve fibers and axon regeneration was observed by TEM. The three motor function scores in hyperbaric oxygen group at each time point after two weeks of treatment were significantly increased compared with spinal cord injury group (P hyperbaric oxygen group were significantly lower than those in spinal cord injury group (P hyperbaric oxygen group was significantly lower (P hyperbaric oxygen group and spinal cord injury group in order; the differences among the groups were statistically significant (P hyperbaric oxygen group; unmyelinated and myelinated nerve fibers in hyperbaric oxygen group were more than those in spinal cord injury group. Hyperbaric oxygen therapy played a protective effect on spinal cord injury through reducing apoptosis of

  12. Graphene Oxide Catalyzed C-H Bond Activation: The Importance Oxygen Functional Groups for Biaryl Construction

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Yongjun; Tang, Pei; Zhou, Hu; Zhang, Wei; Yang, Hanjun; Yan, Ning; Hu, Gang; Mei, Donghai; Wang, Jianguo; Ma, Ding

    2016-02-24

    A heterogeneous, inexpensive and environment-friendly carbon catalytic system was developed for the C-H bond arylation of benzene resulting in the subsequent formation of biaryl compounds. The oxygen-containing groups on these graphene oxide sheets play an essential role in the observed catalytic activity. The catalytic results of model compounds and DFT calculations show that these functional groups promote this reaction by stabilization and activation of K ions at the same time of facilitating the leaving of I. And further mechanisms studies show that it is the charge induced capabilities of oxygen groups connected to specific carbon skeleton together with the giant π-reaction platform provided by the π-domain of graphene that played the vital roles in the observed excellent catalytic activity. D. Mei acknowledges the support from the US Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle. Computing time was granted by the grand challenge of computational catalysis of the William R. Wiley Environmental Molecular Sciences Laboratory.

  13. Multi-pollutant treatment of crystalline cellulosic effluent: Function of dissolved oxygen on process control.

    Science.gov (United States)

    Shanthi Sravan, J; Naresh Kumar, A; Venkata Mohan, S

    2016-10-01

    Treatment of crystalline cellulose based wastewater was carried out in periodic discontinuous batch reactor (PDBR). Specific influence of dissolved oxygen on treatment of crystalline cellulosic (CC) wastewater was evaluated in three different microenvironments such as aerobic, anoxic and anaerobic. PDBR-aerobic biosystem documented relatively higher substrate degradation [2.63kgCOD/m(3)-day (92%)] in comparison to PDBR-anoxic [2.12kgCOD/m(3)-day (71%)] and PDBR-anaerobic [1.81kgCOD/m(3)-day (63%)], which is in accordance with the observed DO levels. Similarly, multipollutants viz., phosphates and nitrates removal was observed to be higher in aerobic followed by anoxic and anaerobic operations. Higher nitrate removal in aerobic operation might be attributed to the efficient denitrification carried out by the biocatalyst, which utilizes both nitrates and oxygen as oxidizing agents. Multiscan spectral profiles depicted reduction in color intensity in all three microenvironments that correlated with the substrate degradation observed. Despite the high organic load, PDBR functioned well without exhibiting process inhibition.

  14. Relationship between renal function and extracorporeal membrane oxygenation use: a single-center experience.

    Science.gov (United States)

    Gupta, Punkaj; Carlson, Jacob; Wells, Dennis; Selakovich, Patrick; Robertson, Michael J; Gossett, Jeffrey M; Fontenot, Eudice E; Steiner, Matthew B

    2015-04-01

    The effects of extracorporeal membrane oxygenation (ECMO) support on renal function in children with critical illness are unknown. The objective of this study was to investigate the impact of ECMO on renal function among children in different age groups. We performed a single-center retrospective observational study in critically ill children ≤ 18 years supported on ECMO for refractory cardiac or pulmonary failure (2006-2012). The patient population was divided into four age groups for the purpose of comparisons. The Acute Kidney Injury Network's (AKIN's) validated, three-tiered staging system for acute kidney injury was used to categorize the degree of worsening renal function. Data on patient demographics, baseline characteristics, renal function parameters, dialysis, ultrafiltration, duration of mechanical cardiac support, and mortality were collected. Comparisons of baseline characteristics, duration of mechanical cardiac support, and renal function were made between the four age groups. During the study period, 311 patients qualified for inclusion, of whom 289 patients (94%) received venoarterial (VA) ECMO, 12 (4%) received venovenous (VV) ECMO, and 8 (3%) received both VV and VA ECMO. A total of 109 patients (36%) received ultrafiltration on ECMO, 58 (19%) received hemodialysis, and 51 (16%) received peritoneal dialysis. There was a steady and sustained improvement in renal function in all age groups during the ECMO run, with the maximum and longest-sustained improvement occurring in the oldest age group. Proportions of patients in different AKIN stages remained similar in the first 7 days after ECMO initiation. We demonstrate that renal dysfunction improves early after ECMO support. Irrespective of the underlying disease process or patient age, renal function improves in children with pulmonary or cardiac failure who are placed on ECMO.

  15. Mitochondrial metabolism, reactive oxygen species, and macrophage function-fishing for insights.

    Science.gov (United States)

    Hall, Christopher J; Sanderson, Leslie E; Crosier, Kathryn E; Crosier, Philip S

    2014-11-01

    Metabolism and defense mechanisms that protect against pathogens are two fundamental requirements for the survival of multicellular organisms. Research into metabolic disease has revealed these core mechanisms are highly co-dependent. This emerging field of research, termed immunometabolism, focuses on understanding how metabolism influences immunological processes and vice versa. It is now accepted that obesity influences the immune system and that obesity-driven inflammation contributes to many diseases including type 2 diabetes, cardiovascular disease and Alzheimer's disease. The immune response requires the reallocation of nutrients within immune cells to different metabolic pathways to satisfy energy demands and the production of necessary macromolecules. One aspect of immunometabolic research is understanding how these metabolic changes help regulate specific immune cell functions. It is hoped that further understanding of the pathways involved in managing this immunological-metabolic interface will reveal new ways to treat metabolic disease. Given their growing status as principle drivers of obesity-associated inflammation, monocytes/macrophages have received much attention when studying the consequences of inflammation within adipose tissue. Less is known regarding how metabolic changes within macrophages (metabolic reprogramming) influence their immune cell function. In this review, we focus on our current understanding of how monocytes/macrophages alter their intracellular metabolism during the immune response and how these changes dictate specific effector functions. In particular, the immunomodulatory functions of mitochondrial metabolism and mitochondrial reactive oxygen species. We also highlight how the attributes of the zebrafish model system can be exploited to reveal new mechanistic insights into immunometabolic processes.

  16. In vitro function of random donor platelets stored for 7 days in composol platelet additive solution

    Directory of Open Access Journals (Sweden)

    Gupta Ashish

    2011-01-01

    Full Text Available Background and Aim: Platelets are routinely isolated from whole blood and stored in plasma for 5 days. This study was done to assess the in vitro function of random donor platelets stored for 7 days in composol platelet additive solution at 22°C. Materials and Methods: The study sample included 30 blood donors of both sex in State Blood Bank, C S M Medical University, Lucknow. Random donor platelets were prepared by the platelet-rich plasma method. Whole blood (350 ml was collected in anticoagulant Citrate Phosphate Dextrose Adenine triple blood bags. Random donor platelets were stored for 7 days at 22°C in platelet incubators and agitators with and without additive solution. Results: Platelet swirling was present in all the units at 22°C on day 7 with no evidence of bacterial contamination. Comparison of the mean values of platelet count, platelet factor 3, lactate dehydrogenase, pH, glucose and platelet aggregation showed no significant difference in additive solution while platelet factor 3, glucose and platelet aggregation showed significant difference (P < 0.001 on day 7 without additive solution at 22°C. Conclusion: Our study infers that the platelet viability and aggregation were the best maintained within normal levels on day 7 of storage in platelet additive solution at 22°C. Thus, we may conclude that in vitro storage of random donor platelets with an extended shelf life of 7 days using platelet additive solution may be advocated to improve the inventory of platelets.

  17. Nano- and Microgels Through Addition Reactions of Functional Oligomers and Polymers

    Science.gov (United States)

    Albrecht, Krystyna; Moeller, Martin; Groll, Juergen

    Nano- and Microgels are predominantly prepared using radical polymerization techniques. This chapter reviews alternative approaches to microgel preparation based on addition reactions of functional oligomers and polymers. This allows preparation of microgels under physiological conditions and in the presence of biologically active molecules without affecting their function. This method is therefore predominantly used to synthesize microgels for biomedical applications. Different crosslinking chemistries that have been used in this context are presented and discussed with regard to reaction conditions and stability of the reaction product. Microgels that have been prepared by these techniques are divided into two groups. Natural polymers used for the preparation of microgels are described first, followed by artificial prepolymers that are suitable for the preparation of microgels. The different preparation methods as well as the resulting microgels and their properties are presented and discussed.

  18. The additive nonparametric and semiparametric Aalen model as the rate function for a counting process

    DEFF Research Database (Denmark)

    Scheike, Thomas Harder

    2002-01-01

    We use the additive risk model of Aalen (Aalen, 1980) as a model for the rate of a counting process. Rather than specifying the intensity, that is the instantaneous probability of an event conditional on the entire history of the relevant covariates and counting processes, we present a model...... for the rate function, i.e., the instantaneous probability of an event conditional on only a selected set of covariates. When the rate function for the counting process is of Aalen form we show that the usual Aalen estimator can be used and gives almost unbiased estimates. The usual martingale based variance...... estimator is incorrect and an alternative estimator should be used. We also consider the semi-parametric version of the Aalen model as a rate model (McKeague and Sasieni, 1994) and show that the standard errors that are computed based on an assumption of intensities are incorrect and give a different...

  19. Effects of psychological well-being, physical status, and social support on oxygen-dependent COPD patients' level of functioning.

    Science.gov (United States)

    Lee, R N; Graydon, J E; Ross, E

    1991-10-01

    Thirty oxygen-dependent patients with chronic obstructive pulmonary disease (COPD) participated in a descriptive correlational study in which investigators examined the relationship between oxygen-dependent COPD patients' psychological well-being, physical status, social support, and level of functioning. Lazarus and Folkman's (1984) theory of psychological stress and coping was used to guide the study. Using multiple regression analysis, physical symptoms had the most predictive power in relation to the level of functioning, accounting for 44.3% of the variance. Among the symptoms, dyspnea had the greatest influence on functioning.

  20. The Additive Effects of Type-2 Diabetes on Cognitive Function in Older Adults with Heart Failure

    Directory of Open Access Journals (Sweden)

    Michael L. Alosco

    2012-01-01

    Full Text Available Background. Medical comorbidity has been theorized to contribute to cognitive impairment in heart failure (HF patients. Specifically, type-2 diabetes mellitus (T2DM, a common coexisting condition among HF patients, may be an independent predictor of cognitive impairment. Nonetheless, the relationships between T2DM and other risk factors for cognitive impairment among persons with HF are unclear. Methods. Persons with HF (N=169, 34.3% women, age 68.57±10.28 years completed neuropsychological testing within a framework of an ongoing study. History of T2DM, along with other medical characteristics, was ascertained through a review of participants’ medical charts and self-report. Results. Many participants (34.9% had a comorbid T2DM diagnosis. After adjustment for demographic and medical characteristics, HF patients with T2DM evidenced significantly greater impairments across multiple cognitive domains than HF patients without T2DM: λ=.92, F(5,156=2.82, P=.018. Post hoc tests revealed significant associations between T2DM and attention (P=.003, executive function (P=.032, and motor functioning (P=.008. Conclusion. The findings suggest additive contributions of T2DM and HF to impairments in attention, executive function, and motor function. Future work is needed to elucidate the mechanisms by which T2DM exacerbates cognitive impairment in HF.

  1. On Measurement of Efficiency of Cobb-Douglas Production Function with Additive and Multiplicative Errors

    Directory of Open Access Journals (Sweden)

    Md. Moyazzem Hossain

    2015-02-01

    Full Text Available In developing counties, efficiency of economic development has determined by the analysis of industrial production. An examination of the characteristic of industrial sector is an essential aspect of growth studies. The most of the developed countries are highly industrialized as they brief “The more industrialization, the more development”. For proper industrialization and industrial development we have to study industrial input-output relationship that leads to production analysis. For a number of reasons econometrician’s belief that industrial production is the most important component of economic development because, if domestic industrial production increases, GDP will increase, if elasticity of labor is higher, implement rates will increase and investment will increase if elasticity of capital is higher. In this regard, this paper should be helpful in suggesting the most suitable Cobb-Douglas production function to forecast the production process for some selected manufacturing industries of developing countries like Bangladesh. This paper choose the appropriate Cobb-Douglas function which gives optimal combination of inputs, that is, the combination that enables it to produce the desired level of output with minimum cost and hence with maximum profitability for some selected manufacturing industries of Bangladesh over the period 1978-79 to 2011-2012. The estimated results shows that the estimates of both capital and labor elasticity of Cobb-Douglas production function with additive errors are more efficient than those estimates of Cobb-Douglas production function with multiplicative errors.

  2. Immobilization of alkynyl functionalized manganese phthalocyanine via click electrochemistry for electrocatalytic oxygen evolution reaction.

    Science.gov (United States)

    Öztaş, B; Akyüz, D; Koca, A

    2017-10-04

    Peripherally and non-peripherally terminal alkynyl substituted manganese phthalocyanines (MnPc) were synthesized and characterized and then used as functional materials in modified electrodes. MnPcs were substituted with alkynyl groups, which are reactive moieties in click electrochemistry (CEC) reactions. Mn(iii) cations were incorporated into the cavity of the Pc ring in order to increase the redox activity of the complexes. Electrochemical characterizations of the complexes were determined by voltammetric and in situ spectroelectrochemical measurements in order to determine their possible technological applications. MnPc complexes illustrated five redox couples and these redox couples were assigned as [Cl-Mn(III)Pc(2-)]/[Cl-Mn(II)Pc(2-)](1-), [Cl-Mn(II)Pc(2-)](1-)/[Cl-Mn(I)Pc(2-)](2-), [Cl-Mn(I)Pc(2-)](2-)/[ Cl-Mn(I)Pc(3-)](3-), and [Cl-Mn(III)Pc(2-)]/[Cl-Mn(III)Pc(1-)](1+) redox processes. The position of the substituents affected the mechanism of the redox reactions and influenced the tendency to react with the molecular oxygen. Moreover, changing the position of the substituents slightly influenced the peak potentials and reversibility of the redox processes. For the applications, modified electrodes (ITO/PANI-N3-MnPc and GCE/PANI-N3-MnPc) were constructed with CEC reaction between azido functionalized polyaniline (PANI-N3) and terminally alkynyl substituted MnPcs and these electrodes. Voltammetric characterizations of the modified electrodes illustrated suitable redox activity and conductivity for the practical applications. Finally, the GCE/PANI-N3-MnPc electrode was tested as a potential electrocatalyst for water splitting reaction. Although the GCE/PANI-N3-MnPc electrode did not catalyze the hydrogen evolution reaction (HER), it significantly catalyzed the oxygen evolution reaction (OER) in aqueous solution.

  3. Angiography for renal artery stenosis: no additional impairment of renal function by angioplasty

    Energy Technology Data Exchange (ETDEWEB)

    Lufft, Volkmar; Fels, Lueder M.; Egbeyong-Baiyee, Daniel; Olbricht, Christoph J. [Abteilung Nephrologie, Medizinische Hochschule Hannover (Germany); Hoogestraat-Lufft, Linda; Galanski, Michael [Abteilung Diagnostische Radiologie, Medizinische Hochschule Hannover (Germany)

    2002-04-01

    The aim of this study was to compare renal function between patients with renal angiography and patients with renal angiography and angioplasty (AP) for renal artery stenosis (RAS). Forty-seven patients with suspected RAS were prospectively investigated by digital subtraction angiography (DSA) using non-ionic low osmolar contrast media (CM). In 22 patients RAS was detected and in 16 cases an angioplasty was performed in the same session. The following parameters were determined 1 day prior to and after the DSA, respectively: serum creatinine (S-Crea, {mu}mol/l) and single-shot inulin clearance (In-Cl, ml/min) for the evaluation of renal function; and urine alpha 1-microglobuline (AMG, {mu}g/g Crea) and beta-N-acetyl-glucoseaminidase (beta-NAG, U/g Crea) as markers of tubular toxicity. Serum creatinine was measured additionally 2 days after CM had been injected. In both groups with and without AP 174{+-}65 and 104{+-}56 ml of CM (p<0.0005) were used, respectively. There were no differences with regard to renal function or risk factors for CM nephrotoxicity between both groups. In the group with AP S-Crea and In-Cl (each: mean{+-}SD) did not change significantly (before DSA: 171{+-}158 and 61{+-}24, after DSA: 189{+-}177 and 61{+-}25, respectively), beta-NAG (median) rose from 4 to 14 (p<0.05) and AMG from 8 to 55 (n.s., because of high SD). In the group without AP S-Crea increased from 134{+-}109 to 141{+-}113 (p<0.01), In-Cl dropped from 65{+-}26 to 62{+-}26 (p<0,01), beta NAG (median) rose from 4 to 8 (p=0.01), and AMG from 7 to 10 (n.s.). A rise in baseline S-Crea by more than 25% or 44 {mu}mol/l occurred in 4 and 2 patients in the group with and without AP, respectively. Creatinine increase was reversible in all cases within 7 days. In this study using sensitive methods to detect changes of renal function and tubular toxicity no additional renal function impairment in DSA with angioplasty for RAS compared with DSA alone could be demonstrated. Our data suggest

  4. Two levels of the inspired oxygen fraction in propofol-anesthetized dogs with high intracranial pressure: cardiopulmonary function

    Directory of Open Access Journals (Sweden)

    P.C. Ferro Lopes

    2014-10-01

    Full Text Available In the initial stage of traumatic brain injury, the use of 1.0 inspired oxygen fraction (FiO2 is indicated. However, high FiO2 has been correlated with atelectasis. Thus, the effects of FiO2 = 1.0 and FiO2 = 0.6 on the cardiopulmonary function in propofol-anesthetized dogs with high intracranial pressure (ICP were evaluated. Eight dogs were anesthetized on two occasions, receiving, during controlled ventilation, an FiO2 = 1 (G100 or an FiO2 = 0.6 (G60. Propofol was used for induction (10mg.kg-1 followed by a continuous rate infusion (0.6mg.kg-1.minute-1. An increase in the ICP was induced by temporary obliteration of the right jugular vein (OJv 50 minutes after induction of anesthesia. The measurement was taken twenty minutes after OJv (T0 and then at 15-minute intervals (T15 to T60. Alveolar oxygen partial pressure in G60 was lower than in G100 during the whole procedure. Alveolar-arterial oxygen gradient in G100 was greater than in G60 at T0 and at T60. No differences were observed for arterial oxygen partial pressure/inspired oxygen fraction ratio, arterial-to-alveolar oxygen pressure ratio, respiratory index, venous admixture, oxygen delivery, oxygen consumption, oxygen extraction, heart rate, mean pulmonary arterial pressure, pulmonary arterial occlusion pressure, cardiac index, stroke index and systemic vascular resistance index. In G100, mean arterial pressure at T0 was higher than at T45. In dogs with high ICP, the cardiopulmonary function was not influenced by the different FiO2 used.

  5. Impact of Hyperbaric Oxygenation on the Phagocytosis-Stimulating Function of the Operated Liver

    Directory of Open Access Journals (Sweden)

    P. N. Savilov

    2008-01-01

    Full Text Available Objective: to study the ability of hyperbaric oxygenation (HBO to eliminate impaired phagocytosis-stimulating hepatic function caused by hepatectomy (HE. Material and methods. Experiments were conducted on 82 outbred female albino rats exposed to HE (15—20% of the organ mass and HBO at 3 ata for 50 min once daily three times within the first three days after surgery. The capacities of neutrophils and monocytes of arterial (aorta and venous (portal vein, hepatic veins blood to ingest and digest S.aureus were investigated. Results: Under HBO, the inhibitory impact of HE on the phagocytosis-stimulating ability of the liver to S.aureus was limited for neutrophils and completely precluded for monocytes. In the posthyperoxic period, the phagocytosis-stimulating function of the operated liver was found to be active against the microbe being examined for both types of phagocytes. This was attended by inhibition of the anhepatic mechanisms responsible for the amplified phagocytic activity of neutrophils and monocytes, which were triggered in HE. HBO selectively regulated the arterial and venous blood content of neutrophils, by ingesting and digesting S.aureus as much as possible. HBO prevented the post-HE delay of the neutrophils and monocytes which actively englobed S.aureus in the operated organ. Conclusion: HBO eliminates HE-induced impairment of phagocytosis-stimulating function of the liver and creates conditions for its delayed activation by day 11 posthy-peroxia. Key words: hyperoxia, phagocytosis, regulation, liver, resection.

  6. Preparation and Characterization of Nanocomposite Polymer Membranes Containing Functionalized SnO2 Additives

    Directory of Open Access Journals (Sweden)

    Roberto Scipioni

    2014-03-01

    Full Text Available In the research of new nanocomposite proton-conducting membranes, SnO2 ceramic powders with surface functionalization have been synthesized and adopted as additives in Nafion-based polymer systems. Different synthetic routes have been explored to obtain suitable, nanometer-sized sulphated tin oxide particles. Structural and morphological characteristics, as well as surface and bulk properties of the obtained oxide powders, have been determined by means of X-ray diffraction (XRD, scanning electron microscopy (SEM, Fourier Transform Infrared (FTIR and Raman spectroscopies, N2 adsorption, and thermal gravimetric analysis (TGA. In addition, dynamic mechanical analysis (DMA, atomic force microscopy (AFM, thermal investigations, water uptake (WU measurements, and ionic exchange capacity (IEC tests have been used as characterization tools for the nanocomposite membranes. The nature of the tin oxide precursor, as well as the synthesis procedure, were found to play an important role in determining the morphology and the particle size distribution of the ceramic powder, this affecting the effective functionalization of the oxides. The incorporation of such particles, having sulphate groups on their surface, altered some peculiar properties of the resulting composite membrane, such as water content, thermo-mechanical, and morphological characteristics.

  7. Impact of oxygenated additives to diesel-biodiesel blends in the context of performance and emissions characteristics of a CI engine

    Science.gov (United States)

    Mahmudul, H. M.; Hagos, Ftwi Y.; Mamat, Rizalman; Abdullah, Abdul A.

    2016-11-01

    Butanol is receiving huge interest in the area of alternative fuel in the compression ignition (CI) engines. In this work, butanol is used as an oxygenated additive to diesel and biodiesel blend fuels to evaluate the performance and emission of CI engine. The commercially available pure diesel fuel (D100) and 80% commercially available diesel- biodiesel bled (5% biodiesel and 95% by volume) and 20% butanol (BU20) fuels were investigated to evaluate the effects of the fuel blends on the performance and exhaust emissions of a single cylinder diesel engine. The experiment was conducted at fixed load of 75% with the five engine speeds (from 1200-2400 rpm with an interval of 300 rpm). The engine performance parameters such as power, torque, fuel consumption and thermal efficiency and exhaust gas emissions such as nitrogen oxides, carbon monoxide, and exhaust gas temperature were analysed from the experimental data. The results shows that although butanol addition has caused a slight reduction in power and torque values (11.1% and 3.5%, respectively), the emission values of the engine were improved. With respect to the exhaust gas temperature, CO and NOx emissions, of BU20 is reported to have reduction by 17.7%, 20% and 3%, respectively than the B100. Therefore, butanol can be used as a fuel additive to diesel-biodiesel blends.

  8. Functional Status and Quality of Life in Survivors of Extracorporeal Membrane Oxygenation After the Norwood Operation.

    Science.gov (United States)

    Friedland-Little, Joshua M; Uzark, Karen; Yu, Sunkyung; Lowery, Ray; Aiyagari, Ranjit; Hirsch-Romano, Jennifer C

    2017-06-01

    Infants who require extracorporeal membrane oxygenation (ECMO) support after a Norwood operation are at increased risk for early and late death compared with patients who do not require ECMO post-Norwood. Little is known about the effect that ECMO post-Norwood has on functional status and quality of life among long-term survivors. We prospectively evaluated functional status and health-related quality of life in 12 surviving patients (cases) and 19 corresponding patients (controls) from a previous retrospective case-control assessment of long-term survival in patients requiring ECMO post-Norwood. Functional status was assessed with the Vineland Adaptive Behavior Scale-II, and health-related quality of life was assessed with the Pediatric Quality of Life Inventory (PedsQL) core and cardiac modules. There were no differences in demographics, extracardiac or genetic anomalies, or age at follow-up assessment between ECMO cases and non-ECMO controls. The Vineland Adaptive Behavior Scale-II scores were comparable between groups, with both groups demonstrating function in the normal range in all four domains tested. The only difference in PedsQL scores between cases and controls was perceived physical appearance, which was lower among ECMO survivors by both patient and proxy report. PedsQL scores of both groups were comparable to published scores for patients with single-ventricle congenital heart disease but generally lower than scores for the healthy population. The requirement for ECMO support after a Norwood operation does not appear to significantly affect functional status or quality of life among the subset of patients who achieve long-term survival. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  9. Integrating products of Bessel functions with an additional exponential or rational factor

    Science.gov (United States)

    Van Deun, Joris; Cools, Ronald

    2008-04-01

    We provide two MATLAB programs to compute integrals of the form ex∏i=1kJν_i(ax)dxand 0∞xr+x∏i=1kJν_i(ax)dx with Jν_i(x) the Bessel function of the first kind and (real) order ν. The parameter m is a real number such that ∑ν+m>-1 (to assure integrability near zero), r is real and the numbers c and a are all strictly positive. The program can deliver accurate error estimates. Program summaryProgram title: BESSELINTR, BESSELINTC Catalogue identifier: AEAH_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEAH_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 1601 No. of bytes in distributed program, including test data, etc.: 13 161 Distribution format: tar.gz Programming language: Matlab (version ⩾6.5), Octave (version ⩾2.1.69) Computer: All supporting Matlab or Octave Operating system: All supporting Matlab or Octave RAM: For k Bessel functions our program needs approximately ( 500+140k) double precision variables Classification: 4.11 Nature of problem: The problem consists in integrating an arbitrary product of Bessel functions with an additional rational or exponential factor over a semi-infinite interval. Difficulties arise from the irregular oscillatory behaviour and the possible slow decay of the integrand, which prevents truncation at a finite point. Solution method: The interval of integration is split into a finite and infinite part. The integral over the finite part is computed using Gauss-Legendre quadrature. The integrand on the infinite part is approximated using asymptotic expansions and this approximation is integrated exactly with the aid of the upper incomplete gamma function. In the case where a rational factor is present, this factor is first expanded in a Taylor series around infinity. Restrictions: Some (and eventually all

  10. Hydrogen, oxygen and hydroxyl on porous silicon surface: A joint density-functional perturbation theory and infrared spectroscopy approach

    Energy Technology Data Exchange (ETDEWEB)

    Alfaro, Pedro; Palavicini, Alessio; Wang, Chumin, E-mail: chumin@unam.mx

    2014-11-28

    Based on the density functional perturbation theory (DFPT), infrared absorption spectra of porous silicon are calculated by using an ordered pore model, in which columns of silicon atoms are removed along the [001] direction and dangling bonds are initially saturated with hydrogen atoms. When these atoms on the pore surface are gradually replaced by oxygen ones, the ab-initio infrared absorption spectra reveal oxygen, hydroxyl, and coupled hydrogen–oxygen vibrational modes. In a parallel way, freestanding porous silicon samples were prepared by using electrochemical etching and they were further thermally oxidized in a dry oxygen ambient. Fourier transform infrared spectroscopy was used to investigate the surface modifications caused by oxygen adsorption. In particular, the predicted hydroxyl and oxygen bound to the silicon pore surface are confirmed. Finally, a global analysis of measured transmittance spectra has been performed by means of a combined DFPT and thin-film optics approach. - Highlights: • The density functional perturbation theory is used to study infrared absorption. • An ordered pore model is used to investigate the oxidation in porous silicon (PSi). • Infrared transmittance spectra of oxidized PSi freestanding samples are measured.

  11. Oxygen transport and mitochondrial function in porcine septic shock, cardiogenic shock, and hypoxaemia.

    Science.gov (United States)

    Regueira, T; Djafarzadeh, S; Brandt, S; Gorrasi, J; Borotto, E; Porta, F; Takala, J; Bracht, H; Shaw, S; Lepper, P M; Jakob, S M

    2012-08-01

    The relevance of tissue oxygenation in the pathogenesis of organ dysfunction during sepsis is controversial. We compared oxygen transport, lactate metabolism, and mitochondrial function in pigs with septic shock, cardiogenic shock, or hypoxic hypoxia. Thirty-two anaesthetized, ventilated pigs were randomized to faecal peritonitis (P), cardiac tamponade (CT), hypoxic hypoxia (HH) or controls. Systemic and regional blood flows, lactate, mitochondrial respiration, and tissue hypoxia-inducible factor 1 alpha (HIF-1α) were measured for 24 h. Mortality was 50% in each intervention group. While systemic oxygen consumption (VO(2) ) was maintained in all groups, hepatic VO(2) tended to decrease in CT [0.84 (0.5-1.3) vs. 0.42 (0.06-0.8)/ml/min/kg; P = 0.06]. In P, fractional hepatic, celiac trunk, and portal vein blood flows, and especially renal blood flow [by 46 (14-91)%; P = 0.001] decreased. In CT, renal blood flow [by 50.4 (23-81)%; P = 0.004] and in HH, superior mesenteric blood flow decreased [by 38.9 (16-100)%, P = 0.009]. Hepatic lactate influx increased > 100% in P and HH, and > 200% in CT (all P < 0.02). Hepatic lactate uptake remained unchanged in P and HH and converted to release in CT. Mitochondrial respiration remained normal. Muscle adenosine triphosphate (ATP) concentrations decreased in P (5.9 ± 1.4 μmol/g wt vs. 2.8 ± 2.7 μmol/g wt, P = 0.04). HIF-1α expression was not detectable in any group. We conclude that despite shock and renal hypoperfusion, tissue hypoxia is not a major pathophysiological issue in early and established faecal peritonitis. The reasons for reduced skeletal muscle tissue ATP levels in the presence of well-preserved in-vitro muscle mitochondrial respiration should be further investigated. © 2012 The Authors. Acta Anaesthesiologica Scandinavica © 2012 The Acta Anaesthesiologica Scandinavica Foundation.

  12. Left ventricular assist devices improve functional class without normalizing peak oxygen consumption.

    Science.gov (United States)

    Benton, Casey R; Sayer, Gabriel; Nair, Ajith P; Ashley, Kimberly; Domanski, Michael J; Henzlova, Milena J; Anyanwu, Anelechi C; Pinney, Sean P

    2015-01-01

    Heart failure patients supported with left ventricular assist devices (LVAD) enjoy improvements in functional capacity and quality of life. We reasoned that such improvements in exercise capacity should be reflected in an objective increase in peak oxygen consumption as measured by cardiopulmonary exercise testing (CPET). We performed a retrospective review of all recipients of a HeartMate II LVAD at our center from June 2009 to June 2012 who completed CPET. Thirty-seven patients completed CPET an average of 6 months after implantation. Of these, 10 patients had CPET performed before LVAD implantation. Overall, 91.4% of patients improved by at least two New York Heart Association classes, with 34.3% improving by three classes. Postimplant VO2 max was significantly less than predicted (14.7 ± 3.1 vs. 29.8 ± 6.6 ml/kg/min, p VO2 max increased significantly from 11.6 ± 5.0 to 15.4 ± 3.9 ml/kg/min (p = 0.009). VO2 max improves significantly with LVAD support but fails to normalize to predicted values, in spite of improvements in functional class. The severity of preimplantation heart failure does not associate with the degree of VO2 max improvement.

  13. Microglia preconditioned by oxygen-glucose deprivation promote functional recovery in ischemic rats

    Science.gov (United States)

    Kanazawa, Masato; Miura, Minami; Toriyabe, Masafumi; Koyama, Misaki; Hatakeyama, Masahiro; Ishikawa, Masanori; Nakajima, Takashi; Onodera, Osamu; Takahashi, Tetsuya; Nishizawa, Masatoyo; Shimohata, Takayoshi

    2017-01-01

    Cell-therapies that invoke pleiotropic mechanisms may facilitate functional recovery in stroke patients. We hypothesized that a cell therapy using microglia preconditioned by optimal oxygen-glucose deprivation (OGD) is a therapeutic strategy for ischemic stroke because optimal ischemia induces anti-inflammatory M2 microglia. We first delineated changes in angiogenesis and axonal outgrowth in the ischemic cortex using rats. We found that slight angiogenesis without axonal outgrowth were activated at the border area within the ischemic core from 7 to 14 days after ischemia. Next, we demonstrated that administration of primary microglia preconditioned by 18 hours of OGD at 7 days prompted functional recovery at 28 days after focal cerebral ischemia compared to control therapies by marked secretion of remodelling factors such as vascular endothelial growth factor, matrix metalloproteinase-9, and transforming growth factor-β polarized to M2 microglia in vitro/vivo. In conclusion, intravascular administration of M2 microglia preconditioned by optimal OGD may be a novel therapeutic strategy against ischemic stroke. PMID:28195185

  14. THE ADAPTABLE CHANGE OF THE FUNCTION OF T LYMPHOCYTES FOR PHYSICAL EXERCISE WITH OXYGEN

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective To find out the possible regularity and mechanism of the adaptable change of human being T lymphocytes for physical exercise with oxygen and bring the original data for the Movement of All People Improving their Health. Methods We selected 16 untrained female students in university and let them had the same amount of exercise for 8 weeks. After that, we collected the cycle blood at the time point of before exercise, the end of exercise and 1 hour after exercise at the end of the 0,first,2 nd,4 nd,6 nd and 8 nd week respectively, so as to determine its stimuli index (SI) by MTT method. Results In the different time sect, such as the early stage of exercise, quiet condition,as soon as the end of exercise and 1 hour after exercise, we found that the SI were obviously Iower than that of normal (P<0. 05) ,especially in the time sect of the end of exercise. Continuing to 4 weeks,the function of T lymphocytes restored gradualy and it lasted to the 8 th week, the SI in quiet condition and 1 hour after exercise had restored to normal(P>0.05),but in the end of exercise, it still was Iow,however, the extent of the cases selected was in a condition of acute excitability. Conclusion As the bodies adapting to the exercise, the function of T lymphocytes restored slowly and the rate increased faster and faster.

  15. Tunable oxygen functional groups as electro-catalysts on graphite felt surfaces for all vanadium flow batteries

    Energy Technology Data Exchange (ETDEWEB)

    Estevez, Luis; Reed, David M.; Nie, Zimin; Schwarz, Ashleigh M.; Nandasiri, Manjula I.; Kizewski, James P.; Wang, Wei; Thomsen, Edwin C.; Liu, Jun; Zhang, Jiguang; Sprenkle, Vincent L.; Li, Bin

    2016-06-22

    We decorated the surfaces of graphite felts with some oxygen-containing functional groups, such as C-OH, O=C and HO-C=O. And the mole ratios and amounts of these functional groups were effectively adjusted on the graphite surface by a particular method. The catalytic effects of amounts and mole ratio of different kinds of functional groups on VRB electrode performances were investigated in detail.

  16. Phospha-Michael Addition as a New Click Reaction for Protein Functionalization.

    Science.gov (United States)

    Lee, Yan-Jiun; Kurra, Yadagiri; Liu, Wenshe R

    2016-03-15

    A new type of click reaction between an alkyl phosphine and acrylamide was developed and applied for site-specific protein labeling in vitro and in live cells. Acrylamide is a small electrophilic olefin that readily undergoes phospha-Michael addition with an alkyl phosphine. Our kinetic study indicated a second-order rate constant of 0.07 m(-1)  s(-1) for the reaction between tris(2-carboxyethyl)phosphine and acrylamide at pH 7.4. To demonstrate its application in protein functionalization, we used a dansyl-phosphine conjugate to successfully label proteins that were site-specifically installed with N(ɛ) -acryloyl-l-lysine and employed a biotin-phosphine conjugate to selectively probe human proteins that were metabolically labeled with N-acryloyl-galactosamine. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Influence of oxygen flow rate and compost addition on reduction of organic matter in aerated waste layer containing mainly incineration residue

    Institute of Scientific and Technical Information of China (English)

    Hiroshi Asakrura; Kei Nakagawa; Kazuto Endo; Masato Yamada; Yusaku Ono; Yoshiro Ono

    2013-01-01

    Landfilling municipal solid waste incineration (MSWI) residue alkalizes the waste layer,causing a subsequent decrease in microbial activity and a delay in the decomposition of organic matter.In this study,efficiencies of neutralization of the leachate and organic matter decomposition in the waste layer in a column filled with MSWI residue using aeration and compost addition were evaluated.Total organic carbon (TOC) reduction in the waste layer is large at high oxygen flow rate (OFR).To effectively accelerate TOC reduction in the waste layer to which compost was added,a high OFR exceeding that by natural ventilation was required.At day 65,the pH of the leachate when OFR was above 102 mol-O2/(day·m3) was lower than that when OFR was below 101 mol-O2/(day·m3).At the same OFR,the pH of waste sample was lower than that of waste sample with compost.Although leachate neutralization could be affected by compost addition,TOC reduction in the waste layer became rather small.It is possible that humic substances in compost prevent the decomposition of TOC in MSWI residue.

  18. New functional sulfide oxidase-oxygen reductase supercomplex in the membrane of the hyperthermophilic bacterium Aquifex aeolicus.

    Science.gov (United States)

    Prunetti, Laurence; Infossi, Pascale; Brugna, Myriam; Ebel, Christine; Giudici-Orticoni, Marie-Thérèse; Guiral, Marianne

    2010-12-31

    Aquifex aeolicus, a hyperthermophilic and microaerophilic bacterium, obtains energy for growth from inorganic compounds alone. It was previously proposed that one of the respiratory pathways in this organism consists of the electron transfer from hydrogen sulfide (H(2)S) to molecular oxygen. H(2)S is oxidized by the sulfide quinone reductase, a membrane-bound flavoenzyme, which reduces the quinone pool. We have purified and characterized a novel membrane-bound multienzyme supercomplex that brings together all the molecular components involved in this bioenergetic chain. Our results indicate that this purified structure consists of one dimeric bc(1) complex (complex III), one cytochrome c oxidase (complex IV), and one or two sulfide quinone reductases as well as traces of the monoheme cytochrome c(555) and quinone molecules. In addition, this work strongly suggests that the cytochrome c oxidase in the supercomplex is a ba(3)-type enzyme. The supercomplex has a molecular mass of about 350 kDa and is enzymatically functional, reducing O(2) in the presence of the electron donor, H(2)S. This is the first demonstration of the existence of such a respirasome carrying a sulfide oxidase-oxygen reductase activity. Moreover, the kinetic properties of the sulfide quinone reductase change slightly when integrated in the supercomplex, compared with the free enzyme. We previously purified a complete respirasome involved in hydrogen oxidation and sulfur reduction from Aquifex aeolicus. Thus, two different bioenergetic pathways (sulfur reduction and sulfur oxidation) are organized in this bacterium as supramolecular structures in the membrane. A model for the energetic sulfur metabolism of Aquifex aeolicus is proposed.

  19. Engineering thermoplastics for additive manufacturing: a critical perspective with experimental evidence to support functional applications.

    Science.gov (United States)

    Cicala, Gianluca; Latteri, Alberta; Del Curto, Barbara; Lo Russo, Alessio; Recca, Giuseppe; Farè, Silvia

    2017-01-28

    Among additive manufacturing techniques, the filament-based technique involves what is referred to as fused deposition modeling (FDM). FDM materials are currently limited to a selected number of polymers. The present study focused on investigating the potential of using high-end engineering polymers in FDM. In addition, a critical review of the materials available on the market compared with those studied here was completed. Different engineering thermoplastics, ranging from industrial grade polycarbonates to novel polyetheretherketones (PEEKs), were processed by FDM. Prior to this, for innovative filaments based on PEEK, extrusion processing was carried out. Mechanical properties (i.e., tensile and flexural) were investigated for each extruded material. An industrial-type FDM machine (Stratasys Fortus® 400 mc) was used to fully characterize the effect of printing parameters on the mechanical properties of polycarbonate. The obtained properties were compared with samples obtained by injection molding. Finally, FDM samples made of PEEK were also characterized and compared with those obtained by injection molding. The effect of raster to raster air gap and raster angle on tensile and flexural properties of printed PC was evidenced; the potential of PEEK filaments, as novel FDM material, was highlighted in comparison to state of the art materials. Comparison with injection molded parts allowed to better understand FDM potential for functional applications. The study discussed pros and cons of the different materials. Finally, the development of novel PEEK filaments achieved important results offering a novel solution to the market when high mechanical and thermal properties are required.

  20. Hydrogen atom addition to the surface of graphene nanoflakes: A density functional theory study

    Science.gov (United States)

    Tachikawa, Hiroto

    2017-02-01

    Polycyclic aromatic hydrocarbons (PAHs) provide a 2-dimensional (2D) reaction surface in 3-dimensional (3D) interstellar space and have been utilized as a model of graphene surfaces. In the present study, the reaction of PAHs with atomic hydrogen was investigated by means of density functional theory (DFT) to systematically elucidate the binding nature of atomic hydrogen to graphene nanoflakes. PAHs with n = 4-37 were chosen, where n indicates the number of benzene rings. Activation energies of hydrogen addition to the graphene surface were calculated to be 5.2-7.0 kcal/mol at the CAM-B3LYP/6-311G(d,p) level, which is almost constant for all PAHs. The binding energies of hydrogen atom were slightly dependent on the size (n): 14.8-28.5 kcal/mol. The absorption spectra showed that a long tail is generated at the low-energy region after hydrogen addition to the graphene surface. The electronic states of hydrogenated graphenes were discussed on the basis of theoretical results.

  1. Adding functionality with additive manufacturing: Fabrication of titanium-based antibiotic eluting implants.

    Science.gov (United States)

    Cox, Sophie C; Jamshidi, Parastoo; Eisenstein, Neil M; Webber, Mark A; Hassanin, Hany; Attallah, Moataz M; Shepherd, Duncan E T; Addison, Owen; Grover, Liam M

    2016-07-01

    Additive manufacturing technologies have been utilised in healthcare to create patient-specific implants. This study demonstrates the potential to add new implant functionality by further exploiting the design flexibility of these technologies. Selective laser melting was used to manufacture titanium-based (Ti-6Al-4V) implants containing a reservoir. Pore channels, connecting the implant surface to the reservoir, were incorporated to facilitate antibiotic delivery. An injectable brushite, calcium phosphate cement, was formulated as a carrier vehicle for gentamicin. Incorporation of the antibiotic significantly (p=0.01) improved the compressive strength (5.8±0.7MPa) of the cement compared to non-antibiotic samples. The controlled release of gentamicin sulphate from the calcium phosphate cement injected into the implant reservoir was demonstrated in short term elution studies using ultraviolet-visible spectroscopy. Orientation of the implant pore channels were shown, using micro-computed tomography, to impact design reproducibility and the back-pressure generated during cement injection which ultimately altered porosity. The amount of antibiotic released from all implant designs over a 6hour period (additively manufacture a titanium-based antibiotic eluting implant, which is an attractive alternative to current treatment strategies of periprosthetic infections.

  2. Next-generation biomedical implants using additive manufacturing of complex, cellular and functional mesh arrays.

    Science.gov (United States)

    Murr, L E; Gaytan, S M; Medina, F; Lopez, H; Martinez, E; Machado, B I; Hernandez, D H; Martinez, L; Lopez, M I; Wicker, R B; Bracke, J

    2010-04-28

    In this paper, we examine prospects for the manufacture of patient-specific biomedical implants replacing hard tissues (bone), particularly knee and hip stems and large bone (femoral) intramedullary rods, using additive manufacturing (AM) by electron beam melting (EBM). Of particular interest is the fabrication of complex functional (biocompatible) mesh arrays. Mesh elements or unit cells can be divided into different regions in order to use different cell designs in different areas of the component to produce various or continually varying (functionally graded) mesh densities. Numerous design elements have been used to fabricate prototypes by AM using EBM of Ti-6Al-4V powders, where the densities have been compared with the elastic (Young) moduli determined by resonant frequency and damping analysis. Density optimization at the bone-implant interface can allow for bone ingrowth and cementless implant components. Computerized tomography (CT) scans of metal (aluminium alloy) foam have also allowed for the building of Ti-6Al-4V foams by embedding the digital-layered scans in computer-aided design or software models for EBM. Variations in mesh complexity and especially strut (or truss) dimensions alter the cooling and solidification rate, which alters the alpha-phase (hexagonal close-packed) microstructure by creating mixtures of alpha/alpha' (martensite) observed by optical and electron metallography. Microindentation hardness measurements are characteristic of these microstructures and microstructure mixtures (alpha/alpha') and sizes.

  3. Development of an efficient amine-functionalized glass platform by additional silanization treatment with alkylsilane.

    Science.gov (United States)

    Kamisetty, Nagendra Kumar; Pack, Seung Pil; Nonogawa, Mitsuru; Devarayapalli, Kamakshaiah Charyulu; Kodaki, Tsutomu; Makino, Keisuke

    2006-11-01

    Aminosilane-treated molecular layers on glass surfaces are frequently used as functional platforms for biosensor preparation. All the amino groups present on the surface are not available in reactive forms, because surface amino groups interact with remaining unreacted surface silanol groups. Such nonspecific interactions might reduce the efficiency of chemical immobilization of biomolecules such as DNA, enzymes, antibodies, etc., in biosensor fabrication. To improve immobilization efficiency we have used additional surface silanization with alkylsilane (capping) to convert the remaining silanol groups into Si-O-Si linkages, thereby liberating the amino groups from nonspecific interaction with the silanol groups. We prepared different types of capped amine surface and evaluated the effect of capping on immobilization efficiency by investigating the fluorescence intensity of Cy3-NHS (N-hydroxysuccinimide) dye that reacted with amino groups. The results indicate that most of the capped amine surfaces resulted in enhanced efficiency of immobilization of Cy3-NHS compared with the untreated control amine surface. We found a trend that trialkoxysilanes had greater capping effects on immobilization efficiency than monoalkoxysilanes. It was also found that the aliphatic chain of alkylsilane, which does not participate in the capping of the silanol, had an important function in enhancing immobilization efficiency. These results would be useful for preparation of an amine-modified surface platform, with enhanced immobilization efficiency, which is essential for developing many kinds of biosensors on a silica matrix.

  4. Cryptic biodiversity effects: importance of functional redundancy revealed through addition of food web complexity.

    Science.gov (United States)

    Philpott, Stacy M; Pardee, Gabriella L; Gonthier, David J

    2012-05-01

    Interactions between predators and the degree of functional redundancy among multiple predator species may determine whether herbivores experience increased or decreased predation risk. Specialist parasites can modify predator behavior, yet rarely have cascading effects on multiple predator species and prey been evaluated. We examined influences of specialist phorid parasites (Pseudacteon spp.) on three predatory ant species and herbivores in a coffee agroecosystem. Specifically, we examined whether changes in ant richness affected fruit damage by the coffee berry borer (Hypothenemus hampei) and whether phorids altered multi-predator effects. Each ant species reduced borer damage, and without phorids, increasing predator richness did not further decrease borer damage. However, with phorids, activity of one ant species was reduced, indicating that the presence of multiple ant species was necessary to limit borer damage. In addition, phorid presence revealed synergistic effects of multiple ant species, not observed without the presence of this parasite. Thus, a trait-mediated cascade resulting from a parasite-induced predator behavioral change revealed the importance of functional redundancy, predator diversity, and food web complexity for control of this important pest.

  5. Comparison of blood-oxygen-level-dependent functional magnetic resonance imaging and near-infrared spectroscopy recording during functional brain activation in patients with stroke and brain tumors.

    Science.gov (United States)

    Sakatani, Kaoru; Murata, Yoshihiro; Fujiwara, Norio; Hoshino, Tatsuya; Nakamura, Shin; Kano, Tsuneo; Katayama, Yoichi

    2007-01-01

    Blood-oxygen-level-dependent contrast functional magnetic resonance imaging (BOLD-fMRI) has been used to perform functional imaging in brain disorders such as stroke and brain tumors. However, recent studies have revealed that BOLD-fMRI does not image activation areas correctly in such patients. To clarify the characteristics of the evoked cerebral blood oxygenation (CBO) changes occurring in stroke and brain tumors, we have been comparing near-infrared spectroscopy (NIRS) and BOLD-fMRI recording during functional brain activation in these patients. We review our recent studies and related functional imaging studies on the brain disorders. In the primary sensorimotor cortex (PSMC) on the nonlesion side, the motor task consistently caused a decrease of deoxyhemoglobin (deoxy-Hb) with increases of oxyhemoglobin (oxy-Hb) and total hemoglobin (t-Hb), which is consistent with the evoked CBO response observed in normal adults. BOLD-fMRI demonstrated robust activation areas on the nonlesion side. In stroke patients, severe cerebral ischemia (i.e., misery perfusion) caused an increase of deoxy-Hb during the task, associated with increases of oxy-Hb and t-Hb, in the PSMC on the lesion side. In addition, the activation volume of BOLD-fMRI was significantly reduced on the lesion side. The BOLD signal did not change in some areas of the PSMC on the lesion side, but it tended to decrease in other areas during the tasks. In brain tumors, BOLD-fMRI clearly demonstrated activation areas in the PSMC on the lesion side in patients who displayed a normal evoked CBO response. However, the activation volume on the lesion side was significantly reduced in patients who exhibited an increase of deoxy-Hb during the task. In both stroke and brain tumors, false-negative activations (i.e., marked reductions of activation volumes) in BOLD imaging were associated with increases of deoxy-Hb, which could cause a reduction in BOLD signal. BOLD-fMRI investigations of patients with brain disorders

  6. Modification of Polymer Network Properties through the Addition of Functional Nanogel Particles

    Science.gov (United States)

    Liu, JianCheng

    Multifunctional acrylic and methacrylic monomers have been widely applied in many photopolymerization applications to produce crosslinked polymers with advantages such as rapid curing, broad choices of commercially available monomers and desirable physical and mechanical properties. However, there still remain critical challenges for these materials during polymerization including limited conversion and early onset of gelation as well as the generation of significant polymerization shrinkage and stress. This thesis explores the effects of network property modification through the addition of polymeric nanoparticles or nanogels. In order to understand the relationship between nanogel structure and composite material properties, nanogels with different architectures and functionalities were studied during polymerization in terms of kinetics, shrinkage and stress reduction, mechanical performance and reaction mechanisms. Nanogel composite formulations were evaluated to understand the interaction between nanogel structure with the resin matrix during polymerization through adjustment of nanogel branching densities and reactivity of polymer chain ends. It was found that both the chemical crosslinking from reactive chain ends and physical entanglements of high branching density nanogels with the resin matrix dramatically could improve final material mechanical strength. The reductions in overall volumetric shrinkage and shrinkage stress were found to follow at least proportional behavior with respect to nanogel loading concentration while maintaining similar final conversion and modulus results compared with the control resin. Nanogels containing unique functionalities were designed in order to modify reaction mechanism during secondary polymerization. A nanogel containing an integrated photoinitiator and active chain-end RAFT groups was able to initiate secondary polymerization from the nanogel phase so that localized polymerization was achieved from the beginning of

  7. Functional palladium tetrapod core of heterogeneous palladium-platinum nanodendrites for enhanced oxygen reduction reaction

    Science.gov (United States)

    Nguyen, Trung-Thanh; Pan, Chun-Jern; Liu, Jyong-Yue; Chou, Hung-Lung; Rick, John; Su, Wei-Nien; Hwang, Bing-Joe

    2014-04-01

    The synthesis, characterization, and application of bimetallic Pd-Pt nanocatalysts with heterogeneous structures are reported. The Pd tetrapod core is demonstrated to enhance the catalytic activity and durability of Pd@Pt nanodendrites for the oxygen reduction reaction (ORR). Special attention is given to the effects of oxalate-ion-formaldehyde during the hydrothermal synthesis of various Pd morphologies at different temperatures. Pd tetrapod synthesis can be delicately achieved without directly using hazardous CO gas. 30 wt% Pt on tetrapodal and truncated-octahedral Pd cores and 50 wt% Pt on tetrapodal Pd cores are prepared and compared against the commercial Pt/C catalyst (E-Tek) for ORR. The Pdtetrapod@30 wt% Pt catalyst exhibits the highest ORR activity. Overall, the Pd tetrapod core is a functional morphology which offers high-index facets for the subsequent deposition of Pt(110) nanodendrites, with the bimetallic interaction between two materials allowing for good electron transfer from the Pd core onto the Pt surfaces. Both effects contribute to the increased catalytic activity of Pdtetrapod@30 wt% Pt, even under a lower loading of Pt. Furthermore, Pdtetrapod@30 wt% Pt has a rather large particle size (∼39.5 nm) which enhances durability and resistance to the agglomeration of Pt.

  8. Blood transfusion improves renal oxygenation and renal function in sepsis-induced acute kidney injury in rats

    NARCIS (Netherlands)

    L. Zafrani (Lara); B. Ergin (Bulent); Kapucu, A. (Aysegul); C. Ince (Can)

    2016-01-01

    textabstractBackground: The effects of blood transfusion on renal microcirculation during sepsis are unknown. This study aimed to investigate the effect of blood transfusion on renal microvascular oxygenation and renal function during sepsis-induced acute kidney injury. Methods: Twenty-seven Wistar

  9. Microbial respiration and gene expression as a function of very low oxygen concentration

    DEFF Research Database (Denmark)

    Tiano, Laura

    Oxygen (O2) is a fundamental parameter for life. It not only profoundly influences the biogeochemical cycling on a global scale, but also deals with the regulation of metabolic processes at microbial level, in particular the transition between aerobic and anaerobic metabolisms. However, until...... recently, due to the lack of high-resolution methods for O2 concentration determination, several oxygen-related processes, such as aerobic respiration in pelagic aquatic ecosystems and in naturally oxygen poor waters (e.g. Oxygen Minimum Zones, OMZs), or the oxygen regulation of nitrification...... and denitrification, were only partially described. In spite of the importance of aerobic respiration as a key process in the global carbon cycle, the available data are still few, and highly biased with respect to season, latitude and depth. The main aims of this Ph.D were to: i) develop and test a highly...

  10. Microbial respiration and gene expression as a function of very low oxygen concentration

    DEFF Research Database (Denmark)

    Tiano, Laura

    recently, due to the lack of high-resolution methods for O2 concentration determination, several oxygen-related processes, such as aerobic respiration in pelagic aquatic ecosystems and in naturally oxygen poor waters (e.g. Oxygen Minimum Zones, OMZs), or the oxygen regulation of nitrification...... of these pure cultures were lower than found for natural communities of NOB (apparent Km values~ 1- 4 µM), but higher than the ones from the well-studied opportunistic NOB Nitrobacter. The expression of high-affinity terminal oxidases in these NOB could, however, not be confirmed. Overall the results of this Ph......Oxygen (O2) is a fundamental parameter for life. It not only profoundly influences the biogeochemical cycling on a global scale, but also deals with the regulation of metabolic processes at microbial level, in particular the transition between aerobic and anaerobic metabolisms. However, until...

  11. DNA--a molecule in search of additional functions: recipient of pool wave emissions? A hypothesis.

    Science.gov (United States)

    Doerfler, Walter

    2010-09-01

    Almost the entire nucleotide sequence of human DNA is functionally unaccounted for, although large parts of the human genome are transcribed. The genes, as defined by current molecular biology, comprise about 1.5-2% of the DNA molecule. It is proposed that DNA encodes additional, hitherto unrecognized functions. In this discussion, the total information inside and outside the universe we live in is termed the pool or the sum total, known or unknown, of all laws, matter, energy, concepts and events. In a hypothetical model, a Gedankenexperiment, it is suggested that the total of all information emits pool waves of an unknown physical nature. They could be related to black energy or have completely different qualities. The designation pool waves should not imply any similarity to electromagnetism. Further, DNA is suggested to have the capability of interacting with the pool waves and thus permit humans - to some partly genetically determined and yet very limited extent - to perceive information from the pool. Pool emissions might be one of the forces that have been instrumental in and are still driving evolution from simple oligonucleotides to DNA with ever more complex recipient capacities. It will be a major challenge for researchers in the field to unravel these and less hypothetical undetected coding principles in DNA. It is uncertain whether the current trend to search the available DNA sequences with ever more refined computer technology on the basis of our present understanding of biology will detect unknown coding systems. For molecular medicine, research into the genetics of the most common human diseases could profit from the elucidation of presently still ephemeral codes in human DNA. Young scientists with a proven record of original research deserve support for the pursuit of unconventional ideas. This concept of granting priorities will be of the utmost importance in advancing the field beyond current concepts in molecular biology.

  12. Adding functionality with additive manufacturing: Fabrication of titanium-based antibiotic eluting implants

    Energy Technology Data Exchange (ETDEWEB)

    Cox, Sophie C. [School of Chemical Engineering, University of Birmingham, Edgbaston B15 2TT (United Kingdom); Jamshidi, Parastoo [School of Materials and Metallurgy, University of Birmingham, Edgbaston B15 2TT (United Kingdom); Eisenstein, Neil M. [School of Chemical Engineering, University of Birmingham, Edgbaston B15 2TT (United Kingdom); Royal Centre for Defence Medicine, Birmingham Research Park, Vincent Drive, Edgbaston B15 2SQ (United Kingdom); Webber, Mark A. [School of Biosciences, University of Birmingham, Edgbaston B15 2TT (United Kingdom); Hassanin, Hany [School of Materials and Metallurgy, University of Birmingham, Edgbaston B15 2TT (United Kingdom); School of Mechanical and Automotive Engineering, Kingston University, London SW15 3DW (United Kingdom); Attallah, Moataz M. [School of Materials and Metallurgy, University of Birmingham, Edgbaston B15 2TT (United Kingdom); Shepherd, Duncan E.T. [Department of Mechanical Engineering, School of Engineering, University of Birmingham, Edgbaston B15 2TT (United Kingdom); Addison, Owen [School of Dentistry, University of Birmingham, Edgbaston B15 2TT (United Kingdom); Grover, Liam M. [School of Chemical Engineering, University of Birmingham, Edgbaston B15 2TT (United Kingdom)

    2016-07-01

    Additive manufacturing technologies have been utilised in healthcare to create patient-specific implants. This study demonstrates the potential to add new implant functionality by further exploiting the design flexibility of these technologies. Selective laser melting was used to manufacture titanium-based (Ti-6Al-4V) implants containing a reservoir. Pore channels, connecting the implant surface to the reservoir, were incorporated to facilitate antibiotic delivery. An injectable brushite, calcium phosphate cement, was formulated as a carrier vehicle for gentamicin. Incorporation of the antibiotic significantly (p = 0.01) improved the compressive strength (5.8 ± 0.7 MPa) of the cement compared to non-antibiotic samples. The controlled release of gentamicin sulphate from the calcium phosphate cement injected into the implant reservoir was demonstrated in short term elution studies using ultraviolet-visible spectroscopy. Orientation of the implant pore channels were shown, using micro-computed tomography, to impact design reproducibility and the back-pressure generated during cement injection which ultimately altered porosity. The amount of antibiotic released from all implant designs over a 6 hour period (< 28% of the total amount) were found to exceed the minimum inhibitory concentrations of Staphylococcus aureus (16 μg/mL) and Staphylococcus epidermidis (1 μg/mL); two bacterial species commonly associated with periprosthetic infections. Antibacterial efficacy was confirmed against both bacterial cultures using an agar diffusion assay. Interestingly, pore channel orientation was shown to influence the directionality of inhibition zones. Promisingly, this work demonstrates the potential to additively manufacture a titanium-based antibiotic eluting implant, which is an attractive alternative to current treatment strategies of periprosthetic infections. - Highlights: • Titanium implants were additively manufactured with surface connected reservoirs. • Implants

  13. Lowering the effective work function via oxygen vacancy formation on the GeO2/Ge interface

    Science.gov (United States)

    Lee, Tae In; Seo, Yujin; Moon, Jungmin; Ahn, Hyun Jun; Yu, Hyun-Young; Hwang, Wan Sik; Cho, Byung Jin

    2017-04-01

    The use of a GeO2 interfacial layer (IL) between a high-k dielectric and a Ge substrate helps to reduce the interface state density in Ge MOS devices. We report that the presence of the GeO2 IL changes the effective work function (eWF) of the gate stack when annealed after high-k dielectric deposition. The eWF is reduced from 4.31 eV to 3.98 eV for TaN and from 5.00 eV to 4.44 eV for Ni. Consequently, the threshold voltage (Vth) decreases from 0.69 V to 0.21 V for Ni after post deposition annealing. Our investigation confirms that the generation of oxygen vacancies in the GeO2 IL near the Ge substrate is the main cause of the eWF modulation. In addition, the reliability of the GeO2 IL is investigated via the conductance method and a constant-current stress test.

  14. Prefrontal oxygenation during verbal fluency and cognitive function in adolescents with bipolar disorder type II.

    Science.gov (United States)

    Ono, Yasuki; Kikuchi, Mitsuru; Nakatani, Hideo; Murakami, Masako; Nishisaka, Manami; Muramatsu, Tomoko; Munesue, Toshio; Minabe, Yoshio

    2017-02-01

    Evaluation of depressive states in children can be challenging. Most of the studies that have investigated cognitive function and cerebral blood volume changes using functional MRI (fMRI) in bipolar disorder (BD) have been confined to BDI or heterogeneous cohorts with attention-deficit/hyperactivity disorder (ADHD). This study investigated cognitive functions in adolescents with BDII and without ADHD using near-infrared spectroscopy (NIRS) and a Das-Naglieri Cognitive Assessment System (DN-CAS). Ten patients with BDII and without ADHD symptoms and 10 age- and gender-matched healthy controls were enrolled in the present study. NIRS was used to detect hemoglobin concentration changes during a verbal fluency test (VFT). In addition, the DN-CAS was used to evaluate cognitive function in four domains: planning, attention, simultaneous, and successive processing. Significant differences between the BDII and control groups in [oxy-Hb] changes during the early phase of VFT were observed in the lower prefrontal cortex but not in cognitive functioning. Furthermore, there was a significant correlation between planning and attention scores in BD subjects. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Density functional theory study of the effects of alloying additions on sulfur adsorption on nickel surfaces

    Science.gov (United States)

    Malyi, Oleksandr I.; Chen, Zhong; Kulish, Vadym V.; Bai, Kewu; Wu, Ping

    2013-01-01

    Reactions of hydrogen sulfide (H2S) with Nickel/Ytrria-doped zirconia (Ni/YDZ) anode materials might cause degradation of the performance of solid oxide fuel cells when S containing fuels are used. In this paper, we employ density functional theory to investigate S adsorption on metal (M)-doped and undoped Ni(0 0 1) and Ni(1 1 1) surfaces. Based on the performed calculations, we analyze the effects of 12 alloying additions (Ag, Au, Al, Bi, Cd, Co, Cu, Fe, Sn, Sb, V, and Zn) on the temperature of transition between clean (S atoms do not adsorb on the surfaces) and contaminated (S atoms can adsorb on the surfaces spontaneously) M-doped Ni surfaces for different concentrations of H2S in the fuel. Predicted results are consistent with many experimental studies relevant to S poisoning of both Ni/YDZ and M-doped Ni/YDZ anode materials. This study is important to understand S poisoning phenomena and to develop new S tolerant anode materials.

  16. Pulmonary perfusion with oxygenated blood or custodiol HTK solution during cardiac surgery for postoperative pulmonary function in COPD patients

    DEFF Research Database (Denmark)

    Buggeskov, Katrine B; Wetterslev, Jørn; Secher, Niels H;

    2013-01-01

    Five to thirty percent of patients undergoing cardiac surgery present with chronic obstructive pulmonary disease (COPD) and have a 2- to 10-fold higher 30-day mortality risk. Cardiopulmonary bypass (CPB) creates a whole body systemic inflammatory response syndrome (SIRS) that could impair pulmona...... function. Impaired pulmonary function can, however, be attenuated by pulmonary perfusion with oxygenated blood or custodiol HTK (histidine-tryptophan-ketoglutarate) solution....

  17. Higher levels of cardiovascular fitness are associated with better executive function and prefrontal oxygenation in younger and older women

    Directory of Open Access Journals (Sweden)

    Olivier eDupuy

    2015-02-01

    Full Text Available Aim: Many studies have suggested that physical exercise training improves cognition and more selectively executive functions. There is a growing interest to clarify the neurophysiological mechanisms that underlie this effect. The aim of the current study was to evaluate the neurophysiological changes in cerebral oxygenation associated with physical fitness level and executive functions. Method: In this study, 22 younger and 36 older women underwent a maximal graded continuous test (i.e., O2max in order to classifyassign them into a fitness group (higher vs. lower fit. All participants completed neuropsychological paper and pencil testing and a computerized Stroop task (which contained executive and non-executive conditions in which the change in pPrefrontal cortex oxygenation change was evaluated in all participants with a near infrared spectroscopy (NIRS. system during a computerized Stroop task (which contains executive and non-executive conditions. Results: Our findings revealed a Fitness x Condition interaction (p < .05 such that higher fit women scored better on measures of executive functions than lower fit women. In comparison to lower fit women, higher fit women had faster reaction times in the switching (executiveExecutive condition of the computerized Stroop task. No significant effect was observed ion the non-executive condition of the test and no interactions were found with age. In measures of cerebral oxygenation (ΔHbT and ΔHbO2, we found a main effect of fitness on cerebral oxygenation during the Stroop task such that only high fit women demonstrated a significant increase in the right inferior frontal gyrus. Discussion/Conclusion:Higher fit individuals who demonstrate better cardiorespiratory functions (as measured by O2max show faster reaction times and greater cerebral oxygenation in the right inferior frontal gyrus than women with lower fitness levels. The lack of interaction with age, suggests that good

  18. Correlation between single-trial visual evoked potentials and the blood oxygenation level dependent response in simultaneously recorded electroencephalography-functional magnetic resonance imaging

    DEFF Research Database (Denmark)

    Fuglø, Dan; Pedersen, Henrik; Rostrup, Egill;

    2012-01-01

    To compare different electroencephalography (EEG)-based regressors and their ability to predict the simultaneously recorded blood oxygenation level dependent response during blocked visual stimulation, simultaneous EEG-functional magnetic resonance imaging in 10 healthy volunteers was performed...... in different occipital and extraoccipital cortical areas not explained by the boxcar regressor. The results suggest that the P1-N2 regressor is the best EEG-based regressor to model the visual paradigm, but when looking for additional effects like habituation or attention modulation that cannot be modeled...

  19. Silica functionalized Cu(II) catalysed selective oxidation of benzyl alcohols using TEMPO and molecular oxygen as an oxidant

    Indian Academy of Sciences (India)

    Manjulla Gupta; Pankaj Sharma; Monika Gupta; Rajive Gupta

    2015-08-01

    A general scheme for the oxidation of benzyl alcohols catalyzed by silica functionalized copper (II) has been designed. TEMPO, a free radical, assists this oxidation that was initiated by molecular oxygen which converts it to a primary oxidant. This catalytic combination i.e. SiO2 -Cu(II) in presence of TEMPO and oxygen provides excellent results in terms of yields and reaction time. SiO2 -Cu(II) was very well characterized by different spectroscopic techniques such as FTIR, XRD, TGA, XPS, EDAX, SEM, TEM and AAS and is recyclable upto five times which makes it economically beneficial.

  20. Anion-radical oxygen centers in small (AgO)n clusters: density functional theory predictions

    CERN Document Server

    Trushin, Egor V

    2012-01-01

    Anion-radical form of the oxygen centers O(-) is predicted at the DFT level for small silver oxide particles having the AgO stoichiometry. Model clusters (AgO)n appear to be ferromagnetic with appreciable spin density at the oxygen centers. In contrast to these clusters, the Ag2O model cluster have no unpaired electrons in the ground state. The increased O/Ag ratio in the oxide particles is proved to be responsible for the spin density at oxygen centers.

  1. A safer and flexible method for the oxygen functionalization of carbon nanotubes by nitric acid vapors

    Energy Technology Data Exchange (ETDEWEB)

    Santangelo, Saveria, E-mail: saveria.santangelo@unirc.it [Dipartimento di Ingegneria Civile, dell’Energia, dell’Ambiente e dei Materiali (DICEAM), Università “Mediterranea”, 89122 Reggio Calabria (Italy); Piperopoulos, Elpida [Dipartimento di Ingegneria Eletronica, Chimica ed Ingegneria Industriale (DIECII), Università di Messina, 98166 Messina (Italy); Fazio, Enza [Dipartimento di Fisica e di Scienze della Terra (DFST), Università di Messina, 98166 Messina (Italy); Faggio, Giuliana [Dipartimento di Ingegneria dell’Informazione, delle Infrastrutture e dell’Energia Sostenibile (DIIES), Università “Mediterranea”, 89122 Reggio Calabria (Italy); Ansari, Shabana [Dipartimento di Ingegneria Eletronica, Chimica ed Ingegneria Industriale (DIECII), Università di Messina, 98166 Messina (Italy); Lanza, Maurizio [Istituto per i Processi Chimico Fisici (IPCF) del CNR, 98158 Messina (Italy); Neri, Fortunato [Dipartimento di Fisica e di Scienze della Terra (DFST), Università di Messina, 98166 Messina (Italy); Messina, Giacomo [Dipartimento di Ingegneria dell’Informazione, delle Infrastrutture e dell’Energia Sostenibile (DIIES), Università “Mediterranea”, 89122 Reggio Calabria (Italy); Milone, Candida [Dipartimento di Ingegneria Eletronica, Chimica ed Ingegneria Industriale (DIECII), Università di Messina, 98166 Messina (Italy)

    2014-06-01

    The functionalization by nitric acid vapors at azeotropic concentration has been recently proposed to eliminate drawbacks of the widely utilized liquid phase functionalization method. This work suggests to exploit the so-called “salt effect” to improve the vapor phase oxidation method in terms of safety and flexibility. Increasing the relative volatility of acid, the addition of Mg(NO{sub 3}){sub 2} salt to the HNO{sub 3} + H{sub 2}O solution allows (i) obtaining vapors with HNO{sub 3} at the azeotropic concentration from a more diluted liquid solution (i.e. operating under safer conditions), and (ii) varying the concentration of HNO{sub 3} in the vapor phase even above the azeotropic concentration limit (with improved process flexibility). High-resolution transmission electron microscopy, thermo-gravimetry, Raman spectroscopy and X-ray photoemission spectroscopy systematic analyses are carried out on pristine and oxidized nanotubes in order to assess their functionalization degree, surface chemistry and structural evolution. The most relevant finding of this preliminary study is that the nanotube functionalization extent increases linearly with the HNO{sub 3} vapor concentration.

  2. Do cytochromes function as oxygen sensors in the regulation of nitrate reductase biosynthesis?

    Science.gov (United States)

    MacGregor, C H; Bishop, C W

    1977-01-01

    The observation that oxygen represses nitrate reductase biosynthesis in a hemA mutant grown aerobically with or without delta-aminolevulinic acid indicates that cytochromes are not responsible for nitrate reductase repression in aerobically grown cells. PMID:326768

  3. Do dental procedures affect lung function and arterial oxygen saturation in asthmatic patients?

    Directory of Open Access Journals (Sweden)

    Magdy Mahmoud Emara

    2013-04-01

    Conclusion: Asthmatic patients may be at a higher risk of developing oxygen desaturation after dental procedures regardless of their type with and without local anesthesia and a decrease in PEF after dental procedures with local anesthesia.

  4. Nitrogen and oxygen bridged calixaromatics: synthesis, structure, functionalization, and molecular recognition.

    Science.gov (United States)

    Wang, Mei-Xiang

    2012-02-21

    heteracalixaromatics had been reported, owing to the formidable synthetic challenges involved. Apart from thiacalixarene, the synthesis of nitrogen- and oxygen-bridged calixarenes appeared very difficult. But since our first publications in 2004, we have been delighted to see the rapid and tremendous development of the supramolecular chemistry of this new generation of macrocycles. In this Account, I summarize the synthesis of N- and O-bridged calixaromatics and their regiospecific functionalization on the rims and bridging positions, focusing on the fragment coupling approach and contributions from our laboratory. I describe the construction of molecular cages based on heteracalixaromatics and discuss the effect of both bridging heteroatoms and substituents on macrocyclic conformations and cavity sizes. Molecular recognition of neutral organic molecules and charged guest species is also demonstrated. The easy accessibility, rich molecular diversity, unique conformation, and cavity tunability of heteracalixaromatics make them invaluable macrocycles for research in supramolecular chemistry. New heteracalixaromatics, with well-defined conformations and cavity properties, will provide powerful tools for probing noncovalent interactions, leading to the development of new molecular sensing and imaging systems. Multicomponent molecular self-assembly of heteracalixaromatics as functional modules with metals, metal clusters, or charge-neutral species should result in multidimensional solid and soft materials with diverse applications. The profitable incorporation of heteracalixaromatics into molecular devices can also be anticipated in the future. Moreover, the construction of enantiopure, inherently chiral heteracalixaromatics should provide important applications in chiral recognition and asymmetric catalysis.

  5. Switch of SpnR function from activating to inhibiting quorum sensing by its exogenous addition

    Energy Technology Data Exchange (ETDEWEB)

    Takayama, Yuriko [Department of Innovation Systems Engineering, Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585 (Japan); CREST, Japan Science and Technology Agency, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585 (Japan); Kato, Norihiro, E-mail: katon@cc.utsunomiya-u.ac.jp [CREST, Japan Science and Technology Agency, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585 (Japan); Department of Material and Environmental Chemistry, Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585 (Japan)

    2016-09-02

    The opportunistic human pathogen Serratia marcescens AS-1 produces the N-hexanoylhomoserine lactone (C6HSL) receptor SpnR, a homologue of LuxR from Vibrio fischeri, which activates pig clusters to produce the antibacterial prodigiosin. In this study, we attempted to artificially regulate quorum sensing (QS) by changing the role of SpnR in N-acylhomoserine lactone (AHL)-mediated QS. SpnR was obtained as a fusion protein tagged with maltose-binding protein (MBP) from overexpression in Escherichia coli, and its specific affinity to C6HSL was demonstrated by quartz crystal microbalance analysis and AHL-bioassay with Chromobacterium violaceum CV026. Prodigiosin production was effectively inhibited by externally added MBP-SpnR in both wild-type AS-1 and the AHL synthase-defective mutant AS-1(ΔspnI). For the mutant, the induced amount of prodigiosin was drastically reduced to approximately 4% with the addition of 18 μM MBP-SpnR to the liquid medium, indicating 81% trapping of C6HSL. A system for inhibiting QS can be constructed by adding exogenous AHL receptor to the culture broth to keep the concentration of free AHL low, whereas intracellular SpnR naturally functions as the activator in response to QS. - Highlights: • Quorum sensing (QS) regulates the expression of some bacterial genes. • We added an AHL receptor to culture media to inhibit QS in Serratia marcescens AS-1. • The exogenous receptor effectively bound C6HSL and inhibited QS. • This approach can be used to artificially regulate AHL-mediated QS.

  6. Wound angiogenesis as a function of tissue oxygen tension: A mathematical model

    OpenAIRE

    Schugart, Richard C.; Friedman, Avner; Zhao, Rui; Sen, Chandan K.

    2008-01-01

    Wound healing represents a well orchestrated reparative response that is induced by injuries. Angiogenesis plays a central role in wound healing. In this work, we sought to develop the first mathematical model directed at addressing the role of tissue oxygen tension on cutaneous wound healing. Key components of the developed model include capillary tips, capillary sprouts, fibroblasts, inflammatory cells, chemoattractants, oxygen, and the extracellular matrix. The model consists of a system o...

  7. Cognitive Function in a Traumatic Brain Injury Hyperbaric Oxygen Randomized Trial

    Science.gov (United States)

    2015-08-07

    Hyperbaric oxygen (HBO2) is an adjunctive treat- ment for indications such as delayed radiation injury, central retinal artery occlusion, sudden...use in treating carbon monoxide poisoning and resultant acute cerebral injury and delayed neuropsychiatric syndrome [8]. In 2008, we developed...oxygen dose represented as meters of mercury minutes or mHg*min (Wolf). This is the same concept used in radiation oncology, where a total dose is

  8. Density functional theory study of oxygen and water adsorption on SrTiO{sub 3}(001)

    Energy Technology Data Exchange (ETDEWEB)

    Guhl, Hannes

    2010-12-03

    Strontium titanate is an extensively studied material with a wide range of application, for instance in photo-catalysis and most importantly, it is used as a substrate in growth of functional oxides. The surface chemistry is crucial and hence understanding the surface structure on atomic scale is essential for gaining insight into the fundamental processes in the aforementioned applications. Moreover, there exist a lot of evidence that this surface chemistry might be controlled to considerably by extrinsic species, such as residual hydrogen and water. Investigating the properties of water and oxygen on the strontium titanate surface is certainly a natural starting point for a theoretical study based on density functional theory, because these species are practically present on the surface on a wide range of experimental conditions and they are computationally feasible. For the oxygen and water adsorption the binding energy is controlled by long-range surface relaxations leading to an effective repulsion of the adsorbed specimen. The isolated oxygen ad-atom forms a covalently bonded ''quasi-peroxide anion'' in combination with a lattice oxygen atom. Contrariwise, in all investigated configurations containing water molecules and hydroxyl groups, the respective oxygen atoms assumed positions close to the oxygen sites of the continued perovskite lattice of the substrate. Most remarkably, on the strontium oxide termination, the water molecules adsorbs and dissociates effortlessly leading to the formation of a pair of hydroxyl groups. For the titanium dioxide termination, a coverage dependent adsorption mode is observed. Densely packings stabilize water molecules, whereas at lower coverage and finite temperatures the formation of hydroxyl groups is found. The energetics responsible for this behavior is consistent with recent experiments by Iwahori and coworkers. (orig.)

  9. On the Additive Constant of the k-server Work Function Algorithm

    CERN Document Server

    Emek, Yuval; Korman, Amos; Rosen, Adi

    2009-01-01

    We consider the Work Function Algorithm for the k-server problem. We show that if the Work Function Algorithm is c-competitive, then it is also strictly (2c)-competitive. As a consequence of [Koutsoupias and Papadimitriou, JACM 1995] this also shows that the Work Function Algorithm is strictly (4k-2)-competitive.

  10. Unraveling the effect of La A-site substitution on oxygen ion diffusion and oxygen catalysis in perovskite BaFeO3 by data-mining molecular dynamics and density functional theory.

    Science.gov (United States)

    Chen, Chi; Baiyee, Zarah Medina; Ciucci, Francesco

    2015-10-07

    BaFeO3 (BFO) is a promising parent material for high-temperature oxygen catalysis. The effects of La substitution on the oxygen ion diffusion and oxygen catalysis in A-site La-substituted BFO are studied by combining data-driven molecular dynamics (MD) simulations and density functional theory (DFT) calculations. The data-driven MD simulations are capable of providing atomic level information regarding oxygen jumps at different sites, bridging the resolution gap of analysis between MD and DFT. The simulations identify several effects due to the introduction of La. First, according to simple electroneutrality considerations and DFT calculations, La tends to decrease the concentration of oxygen vacancies in BFO. Second, La substitution lowers the activation energy of local oxygen migration, providing faster paths for oxygen diffusion. The MD analysis predicts a higher hopping rate through La-containing bottlenecks as well as easier oxygen jumps from the La-rich cages and lower dwell times of oxygen in those cages. DFT calculations confirm a lower migration energy through La-containing bottlenecks. Third, the electrocatalytic activity of the material decreases with La, as indicated by a lower O p-band center and higher oxygen vacancy formation energies.

  11. Tigecycline MIC testing by broth dilution requires use of fresh medium or addition of the biocatalytic oxygen-reducing reagent oxyrase to standardize the test method.

    Science.gov (United States)

    Bradford, Patricia A; Petersen, Peter J; Young, Mairead; Jones, C Hal; Tischler, Mark; O'Connell, John

    2005-09-01

    Tigecycline is a broad-spectrum glycylcycline antibiotic with activity against not only susceptible gram-positive and gram-negative pathogens but also strains that are resistant to many other antibiotics. In the process of determining quality control (QC) limits for the American Type Culture Collection reference strains for tigecycline, a number of inconsistencies in MICs were encountered which appeared to be related to the age of the Mueller-Hinton broth (MHB) medium used in the MIC testing. The objective of this study was to determine the cause of the discrepant MIC results between fresh and aged MHB. The MICs of tigecycline were determined in MHB that was either prepared fresh (reagent Oxyrase. When tested in fresh media, tigecycline was 2 to 3 dilutions more active against the CLSI-recommended QC strains compared to aged media (MICs of 0.03 to 0.25 and 0.12 to 0.5 mug/ml, respectively). Media aged under anaerobic conditions prior to testing or supplemented with Oxyrase resulted in MICs similar to those obtained in fresh medium (MICs of 0.03 to 0.12 and 0.03 to 0.25 mug/ml, respectively). Time-kill kinetics demonstrated a >3 log(10) difference in viable growth when tigecycline was tested in fresh or Oxyrase-supplemented MHB compared to aged MHB. High-pressure liquid chromatography analysis revealed the accumulation of an early peak (oxidative by-product of tigecycline) to be 3.5% in fresh media and 25.1% in aged media after 24 h and that addition of Oxyrase prevented the accumulation of this oxidized by-product. These results suggested that the activity of tigecycline was affected by the amount of dissolved oxygen in the media. The use of fresh MHB or supplementation with Oxyrase resulted in a more standardized test method for performing MIC tests with tigecycline.

  12. Unexpected Formation of Highly Functionalized Dihydropyrans via Addition-Cyclization Reactions Between Dimethyl Oxoglutaconate and α,β-Unsaturated Hydrazones.

    Science.gov (United States)

    Mullins, Jason E; Etoga, Jean-Louis G; Gajewski, Mariusz; Degraw, Joseph I; Thompson, Charles M

    2009-05-20

    The condensation between dienophiles and α,β-unsaturated hydrazone azadienes was previously reported to afford piperidines. During an attempt to adapt this reaction to the preparation of piperidine-based conformationally-restricted analogs of glutamate, it was discovered that the electrophile, dimethyl oxoglutaconate (DOG) led to highly substituted dihydropyrans in 20-50% yield. The unexpected pyran product likely results from an initial 1,4-addition of the hydrazone to the oxoglutaconate followed by intramolecular cyclization of the resultant enolate oxygen to the α,β-unsaturated iminium ion. Further manipulations afford substituted tetrahydropyran 6-methamino-2,4-dicarboxylic acids.

  13. Role of oxygen functional groups in reduced graphene oxide for lubrication

    Science.gov (United States)

    Gupta, Bhavana; Kumar, Niranjan; Panda, Kalpataru; Kanan, Vigneshwaran; Joshi, Shailesh; Visoly-Fisher, Iris

    2017-01-01

    Functionalized and fully characterized graphene-based lubricant additives are potential 2D materials for energy-efficient tribological applications in machine elements, especially at macroscopic contacts. Two different reduced graphene oxide (rGO) derivatives, terminated by hydroxyl and epoxy-hydroxyl groups, were prepared and blended with two different molecular weights of polyethylene glycol (PEG) for tribological investigation. Epoxy-hydroxyl-terminated rGO dispersed in PEG showed significantly smaller values of the friction coefficient. In this condition, PEG chains intercalate between the functionalized graphene sheets, and shear can take place between the PEG and rGO sheets. However, the friction coefficient was unaffected when hydroxyl-terminated rGO was coupled with PEG. This can be explained by the strong coupling between graphene sheets through hydroxyl units, causing the interaction of PEG with the rGO to be non- effective for lubrication. On the other hand, antiwear properties of hydroxyl-terminated rGO were significantly enhanced compared to epoxy-hydroxyl functionalized rGO due to the integrity of graphene sheet clusters. PMID:28344337

  14. Does progressive resistance strength training as additional training have any measured effect on functional outcomes in older hospitalized patients?

    DEFF Research Database (Denmark)

    Tibaek, Sigrid; Andersen, Christina W.; Pedersen, Sigrid F

    2014-01-01

    OBJECTIVE: To evaluate the effect of progressive resistance strength training as additional training measured on functional outcomes in older hospitalized patients. DESIGN: A single-blinded randomized controlled trial. SETTING: Department of Geriatric Rehabilitation in university hospital...

  15. Transition metal substituted SrTiO3 perovskite oxides as promising functional materials for oxygen sensor

    Science.gov (United States)

    Misra, Sunasira

    2012-07-01

    Modern industries employ several gases as process fluids. Leakage of these gases in the operating area could lead to undesirable consequences. Even in chemical industries, which use large quantities of inert gases in confined areas, accidental leakage of these process gases would result in the reduction of oxygen partial pressure in atmospheric air. For instance, large amounts of gaseous nitrogen and argon are used in pharmaceutical industries, gas filling/bottling plants, operating area of Fast Breeder reactors, etc. Fall of concentration of oxygen in air below 17% could lead to life risk (Asphyxiation) of the working personnel that has to be checked well in advance. Further, when the leaking gas is of explosive nature, its damage potential would be very high if its concentration level in air increases beyond its lower explosive limit. Surveillance of the ambient within these industries at the critical areas and also in the environment around them for oxygen therefore becomes highly essential. Sensitive and selective gas sensors made of advanced materials are required to meet this demand of monitoring environmental pollution. The perovskite class of oxides (ABO3) is chemically stable even at high temperatures and can tolerate large levels of dopants without phase transformations. The electronic properties of this parent functional material can be tailored by adding appropriate dopants that exhibit different valence states. Aliovalent transition metal substituted SrTiO3 perovskites are good mixed ionic and electronic conductors and potential candidates for sensing oxygen at percentage level exploiting their oxygen pressure dependent electrical conductivity. This paper presents the preparation, study of electrical conductivity and oxygen-sensing characteristics of iron and cobalt substituted SrTiO3.

  16. Functional stability of microbial communities from long-term stressed soils to additional disturbance

    NARCIS (Netherlands)

    Tobor-Kaplon, M.A.; Bloem, J.; Ruiter, de P.C.

    2006-01-01

    Functional stability, measured in terms of resistance and resilience of soil respiration rate and bacterial growth rate, was studied in soils from field plots that have been exposed to copper contamination and low pH for more than two decades. We tested whether functional stability follows patterns

  17. Locating protein-coding sequences under selection for additional, overlapping functions in 29 mammalian genomes

    DEFF Research Database (Denmark)

    Lin, Michael F; Kheradpour, Pouya; Washietl, Stefan

    2011-01-01

    synonymous constraint in these regions reflects selection on overlapping functional elements including splicing regulatory elements, dual-coding genes, RNA secondary structures, microRNA target sites, and developmental enhancers. Our results show that overlapping functional elements are common in mammalian...

  18. Biodegradability of oxygen-plasma treated cellulose textile functionalized with ZnO nanoparticles as antibacterial treatment

    Science.gov (United States)

    Primc, Gregor; Tomšič, Brigita; Vesel, Alenka; Mozetič, Miran; Ercegović Ražić, Sanja; Gorjanc, Marija

    2016-08-01

    Samples of bleached cellulose fabric were treated with weakly ionized highly dissociated oxygen plasma in order to improve the binding of ZnO nanoparticles, antibacterial properties and biodegradability. Low specific discharge power of about 24 W l-1 was applied in order to minimize thermal effects following plasma treatment. Optical emission spectroscopy revealed weak etching of the fabric while x-ray photoelectron spectroscopy showed formation of oxygen-rich functional groups. Scanning electron microscopy revealed an improved uptake of ZnO nanoparticles and the standard transfer method highlighted excellent antimicrobial effects for Staphylococcus aureus and Escherichia coli. The biodegradability of all samples was determined using the standard ISO test and revealed excellent results for plasma-treated samples even in cases when they were functionalized using ZnO nanoparticles.

  19. Additive, modular functionalization of reactive self-assembled monolayers: toward the fabrication of multilevel optical storage media.

    Science.gov (United States)

    Gentili, Denis; Barbalinardo, Marianna; Manet, Ilse; Durso, Margherita; Brucale, Marco; Mezzi, Alessio; Melucci, Manuela; Cavallini, Massimiliano

    2015-04-28

    We report a novel strategy based on iterative microcontact printing, which provides additive, modular functionalization of reactive SAMs by different functional molecules. We demonstrate that after printing the molecules form an interpenetrating network at the SAM surface preserving their individual properties. We exploited the process by fabricating new optical storage media that consist of a multilevel TAG.

  20. Additive Friction Stir Deposition of Aluminum Alloys and Functionally Graded Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — State-of-the-art additive manufacturing technologies for metal parts have evolved around powder metallurgy and fusion welding-based processes. Both of these...

  1. Additive Friction Stir Deposition of Aluminum Alloys and Functionally Graded Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — State-of-the-art additive manufacturing technologies for metal parts have evolved primarily around powder metallurgy and fusion welding-based processes. These...

  2. Generalization of Rosenfeld's functional to non-additive hard-spheres: pair structure and test-particle consistency.

    Science.gov (United States)

    Ayadim, A; Amokrane, S

    2010-01-27

    The accuracy of the structural data obtained from the recently proposed generalization to non-additive hard-spheres (Schmidt 2004 J. Phys.: Condens. Matter 16 L351) of Rosenfeld's functional is investigated. The radial distribution functions computed from the direct correlation functions generated by the functional, through the Ornstein-Zernike equations, are compared with those obtained from the density profile equations in the test-particle limit, without and with test-particle consistency. The differences between these routes and the role of the optimization of the parameters of the reference system when the functional is used to obtain the reference bridge functional are discussed in the case of symmetric binary mixtures of non-additive hard-spheres. The case of highly asymmetric mixtures is finally briefly discussed.

  3. Effect of sevoflurane and propofol on cerebral oxygen metabolism in cardiopulmonary bypass and postoperative neurological function injury

    Institute of Scientific and Technical Information of China (English)

    Zhu Zhu; Wei-Wei Li

    2016-01-01

    Objective:To study the effect of sevoflurane and propofol on cerebral oxygen metabolism in cardiopulmonary bypass (CPB) and postoperative neurological function injury.Methods:A total of 48 cases of patients who received mitral valve replacement under CPB in our hospital were selected and randomly divided into sevoflurane group (S group) and propofol group (P group) who received sevoflurane-based intravenous inhalational anesthesia and propofol-based total intravenous anesthesia respectively, cerebral oxygen metabolism indexes were determined before CPB started (T0), when nasopharyngeal temperature fell to a constant low temperature (T1), when CPB ended (T2) and 1 h after CPB ended (T3) respectively during operation, and serum neurological function, cardiac function and liver function injury molecules were determined after operation.Results: Intraoperative SjvO2, AVDO2, O2ER and rSO2 were not significantly different between two groups, SjvO2 at T1 significantly increased, AVDO2 and O2ER significantly decreased and rSO2 didn’t change significantly, SjvO2 at T2 significantly decreased, AVDO2 and O2ER significantly increased and rSO2 didn’t change significantly; postoperative serum NSE, S100β, Aβ, Glu, Asp and Gly levels of S group were significantly lower than those of P group, and CK-MB, LDH, cTnI, ALT and AST levels were not significantly different from those of P group.Conclusion:Both sevoflurane and propofol can maintain the balance of cerebral oxygen metabolism in mitral valve replacement under CPB and protect the cardiac function and liver function, but sevoflurane has more ideal protective effect on postoperative neurological function.

  4. Assessing renal function in children with hydronephrosis - additional feature of MR urography.

    Science.gov (United States)

    Hadjidekov, George; Hadjidekova, Savina; Tonchev, Zahari; Bakalova, Rumiana; Aoki, Ichio

    2011-12-01

    Magnetic resonance urography (MRU) is one of the most attractive imaging modalities in paediatric urology, providing largest diagnostic information in a single protocol. Therefore, the aim of our study was to assess the diagnostic value of MRU in children with urogenital anomalies (especially anomalies of the renal pelvis and ureter) and the renal function using different post-processing functional software. Ninety six children (7 days - 18 years old) were examined. In 54 patients of them, a static T(2) MRU was completed by excretory T(1) MRU after gadolinium administration and functional analysis has been performed using two functional analysis softwares "CHOP-fMRU" and "ImageJ" software. MRU showed suspicious renal and the whole urinary tract anomalies with excellent image quality in all children. In ureteropelvic obstruction, MRU was confirmatory to the other imaging techniques, but it was superior modality concerning the evaluation of end-ureteral anomalies. There was an excellent correlation between the MRU data and diagnosis, determined by surgery. The renal transit times, renal volumes and volumetric differential renal function were assessed separately by "CHOP-fMRU" and "ImageJ" with excellent agreement with 99(m)Tc-DTPA and among them. MRU overcomes a lot of limitations of conventional imaging modalities and has a potential to become a leading modality in paediatric uroradiology. Synthesis of both anatomical and functional criteria in MR urography enables to select the best candidates for surgical treatment. Even small kidney dysfunction can be detected by functional analysis software.

  5. Proton conductive Pt-Co nanoparticles anchoring on citric acid functionalized graphene for efficient oxygen reduction reaction

    Science.gov (United States)

    Zhao, Yige; Liu, Jingjun; Wu, Yijun; Wang, Feng

    2017-08-01

    Designing highly efficient electro-catalysts for the oxygen reduction reaction (ORR) has been regarded as a demanding task in the development of renewable energy sources. However, little attention has been paid on improving Pt-based catalysts by promoting proton transfer from the electrolyte solutions to the catalyst layer at the cathode. Herein, we design proton conductive Pt-Co alloy nanoparticles anchoring on citric acid functionalized graphene (Pt-Co/CA-G) catalysts for efficient ORR. The facile modification approach for graphene can introduce oxygenated functional groups on the graphene surface to promote proton transfer as well as keeping the high electron conductivity without destroying the graphene original structure. The electrochemical results show that the Pt-Co/CA-G catalyst exhibits more excellent ORR activity and stability than the commercial Pt/C catalyst, which can be attributed to its improved proton transfer ability. The fast proton transfer comes from the hydrogen-bonding networks formed by the interaction between the oxygenated functional groups and water molecules. This work provides not only a novel and simple approach to modify graphene but also an effective strategy to improve Pt-based catalysts for the ORR.

  6. Chemical characteristic and functional properties of arenga starch-taro (Colocasia esculanta L.) flour noodle with turmeric extracts addition

    Science.gov (United States)

    Ervika Rahayu N., H.; Ariani, Dini; Miftakhussolikhah, E., Maharani P.; Yudi, P.

    2017-01-01

    Arenga starch-taro (Colocasia esculanta L.) flour noodle is an alternative carbohydrate source made from 75% arenga starch and 25% taro flour, but it has a different color with commercial noodle product. The addition of natural color from turmeric may change the consumer preference and affect chemical characteristic and functional properties of noodle. This research aims to identify chemical characteristic and functional properties of arenga starch-taro flour noodle with turmeric extract addition. Extraction was performed using 5 variances of turmeric rhizome (0.06; 0.12; 0.18; 0.24; and 0.30 g (fresh weight/ml water). Then, noodle was made and chemical characteristic (proximate analysis) as well as functional properties (amylose, resistant starch, dietary fiber, antioxidant activity) were then evaluated. The result showed that addition of turmeric extract did not change protein, fat, carbohydrate, amylose, and resistant starch content significantly, while antioxidant activity was increased (23,41%) with addition of turmeric extract.

  7. Acoustic scattering from multiple spheres by using a kind of addition formulae for the spherical wave functions

    Institute of Scientific and Technical Information of China (English)

    WU Jiuhui; WANG Yaojun; LI Taibao

    2004-01-01

    A kind of addition formulae for the spherical wave functions is generated by using the bicentric expansion of Green function in spherical coordinates. For an acoustical system with multiple spheres, the addition formulae permit the field expansions all referred to the center of one of the spheres, whose boundary conditions can be consequently used to study the multiple scattering easily. The two-sphere acoustical system with different boundary conditions is considered and the field scattered by each sphere can be obtained by solving an infinite set of two linear, complex, algebraic equations, whose coefficients are coupled through double sums in the spherical wave functions. Finally, the form functions of two spheres insonified by a plane wave at arbitrary angles of incidence are calculated and the addition formulae presented are validated by comparing the corresponding numerical results with those of the existing literature.

  8. Mitochondrial function and reactive oxygen species action in relation to boar motility.

    Science.gov (United States)

    Flow cytometric assays of viable boar sperm were developed to measure reactive oxygen species (ROS) formation (oxidization of hydroethidine to ethidium), membrane lipid peroxidation (oxidation of lipophilic probe C11-BODIPY581/591), and mitochondrial inner transmembrane potential (aggregation of mit...

  9. POLYCYCLIC AROMATIC HYDROCARBON BIODEGRADATION AS A FUNCTION OF OXYGEN TENSION IN CONTAMINATED SOIL

    Science.gov (United States)

    Laboratory tests were conducted to determine the effect of soil gas oxygen concentration on the degradation and mineralization of spiked 14C-pyrene and nonspiked 16 priority pollutant polycyclic aromatic hydrocarbons (PAH) present in the soil. The soil used for the evaluation was...

  10. Functional characterization of fetal and adult yak hemoglobins: an oxygen cascade and its molecular basis

    DEFF Research Database (Denmark)

    Weber, Roy E.; Braunitzer, Gerhard; Lalthantluanga, Ralte

    1988-01-01

    In contrast to most other mammals, the yak, which is native to high altitudes, has two major fetal and two or four major adult hemoglobin (Hb) components. We report the oxygen affinities and sensitivities to pH and 2,3-diphosphoglycerate of the two fetal and two adult Hbs commonly found in calves......, compared to those of adult cow Hb A, and relate these findings to their primary structures and to placental maternal-fetal oxygen transfer at altitude. Arranged in order of decreasing oxygen affinity the Hbs are F1 (alpha I2 gamma 2), F2 (alpha II2 gamma 2), A1 (alpha II2 beta II2), and cow Hb A....... The higher affinity of the fetal than the adult yak Hbs correlates with the beta 15Trp -->Phe substitution, whereas the higher affinity in yak than in cow Hb correlates with the beta 135Ala-->Val substitution. The difference in oxygen affinities between yak Hbs A1 and A2, which have identical beta chains...

  11. Angioplasty and stenting for severe vertebral artery oriifce stenosis:effects on cerebellar function remodeling veriifed by blood oxygen level-dependent functional magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    Bo Liu; Zhiwei Li; Peng Xie

    2014-01-01

    Vertebral artery oriifce stenting may improve blood supply of the posterior circulation of the brain to regions such as the cerebellum and brainstem. However, previous studies have mainly focused on recovery of cerebral blood lfow and perfusion in the posterior circulation after inter-ventional therapy. This study examined the effects of functional recovery of local brain tissue on cerebellar function remodeling using blood oxygen level-dependent functional magnetic reso-nance imaging before and after interventional therapy. A total of 40 Chinese patients with severe unilateral vertebral artery oriifce stenosis were enrolled in this study. Patients were equally and randomly assigned to intervention and control groups. The control group received drug treat-ment only. The intervention group received vertebral artery oriifce angioplasty and stenting+identical drug treatment to the control group. At 13 days after treatment, the Dizziness Handicap Inventory score was compared between the intervention and control groups. Cerebellar function remodeling was observed between the two groups using blood oxygen level-dependent function-al magnetic resonance imaging. The improvement in dizziness handicap and cerebellar function was more obvious in the intervention group than in the control group. Interventional therapy for severe vertebral artery oriifce stenosis may effectively promote cerebellar function remodeling and exert neuroprotective effects.

  12. Functional response of osteoblasts in functionally gradient titanium alloy mesh arrays processed by 3D additive manufacturing.

    Science.gov (United States)

    Nune, K C; Kumar, A; Misra, R D K; Li, S J; Hao, Y L; Yang, R

    2017-02-01

    We elucidate here the osteoblasts functions and cellular activity in 3D printed interconnected porous architecture of functionally gradient Ti-6Al-4V alloy mesh structures in terms of cell proliferation and growth, distribution of cell nuclei, synthesis of proteins (actin, vinculin, and fibronectin), and calcium deposition. Cell culture studies with pre-osteoblasts indicated that the interconnected porous architecture of functionally gradient mesh arrays was conducive to osteoblast functions. However, there were statistically significant differences in the cellular response depending on the pore size in the functionally gradient structure. The interconnected porous architecture contributed to the distribution of cells from the large pore size (G1) to the small pore size (G3), with consequent synthesis of extracellular matrix and calcium precipitation. The gradient mesh structure significantly impacted cell adhesion and influenced the proliferation stage, such that there was high distribution of cells on struts of the gradient mesh structure. Actin and vinculin showed a significant difference in normalized expression level of protein per cell, which was absent in the case of fibronectin. Osteoblasts present on mesh struts formed a confluent sheet, bridging the pores through numerous cytoplasmic extensions. The gradient mesh structure fabricated by electron beam melting was explored to obtain fundamental insights on cellular activity with respect to osteoblast functions. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Quantifying additive interactions of the osmolyte proline with individual functional groups of proteins: comparisons with urea and glycine betaine, interpretation of m-values.

    Science.gov (United States)

    Diehl, Roger C; Guinn, Emily J; Capp, Michael W; Tsodikov, Oleg V; Record, M Thomas

    2013-09-03

    To quantify interactions of the osmolyte l-proline with protein functional groups and predict their effects on protein processes, we use vapor pressure osmometry to determine chemical potential derivatives dμ2/dm3 = μ23, quantifying the preferential interactions of proline (component 3) with 21 solutes (component 2) selected to display different combinations of aliphatic or aromatic C, amide, carboxylate, phosphate or hydroxyl O, and amide or cationic N surface. Solubility data yield μ23 values for four less-soluble solutes. Values of μ23 are dissected using an ASA-based analysis to test the hypothesis of additivity and obtain α-values (proline interaction potentials) for these eight surface types and three inorganic ions. Values of μ23 predicted from these α-values agree with the experiment, demonstrating additivity. Molecular interpretation of α-values using the solute partitioning model yields partition coefficients (Kp) quantifying the local accumulation or exclusion of proline in the hydration water of each functional group. Interactions of proline with native protein surfaces and effects of proline on protein unfolding are predicted from α-values and ASA information and compared with experimental data, with results for glycine betaine and urea, and with predictions from transfer free energy analysis. We conclude that proline stabilizes proteins because of its unfavorable interactions with (exclusion from) amide oxygens and aliphatic hydrocarbon surfaces exposed in unfolding and that proline is an effective in vivo osmolyte because of the osmolality increase resulting from its unfavorable interactions with anionic (carboxylate and phosphate) and amide oxygens and aliphatic hydrocarbon groups on the surface of cytoplasmic proteins and nucleic acids.

  14. Addition of Aliskiren to Angiotensin Receptor Blocker Improves Ambulatory Blood Pressure Profile and Cardiorenal Function Better than Addition of Benazepril in Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Satoshi Umemura

    2013-07-01

    Full Text Available An altered ambulatory blood pressure (BP and heart rate (HR profile is related to chronic kidney disease (CKD and cardiorenal syndrome. In this study, we examined the effects of aliskiren, when added to angiotensin II type 1 receptor blockers, on ambulatory BP and cardiorenal function in CKD. Thirty-six hypertensive CKD patients were randomly assigned to the aliskiren add-on group (n = 18 or the benazepril add-on group (n = 18. Ambulatory BP and cardiorenal function parameters were measured at baseline and 24 weeks after treatment. Compared with the benazepril group, nighttime systolic BP variability in the aliskiren group was lower after treatment. Albuminuria was decreased in the aliskiren group, but not in the benazepril group. In addition, left ventricular mass index (LVMI was significantly lower in the aliskiren group than in the benazepril group after treatment. In the aliskiren group, multivariate linear regression analysis showed an association between changes in albuminuria and changes in nighttime systolic BP. Furthermore, there were associations between changes in LVMI and changes in daytime HR variability, as well as between changes in LVMI and changes in plasma aldosterone concentration. These results suggest that aliskiren add-on therapy may be beneficial for suppression of renal deterioration and pathological cardiac remodeling through an improvement that is effected in ambulatory BP and HR profiles.

  15. Assessing renal function in children with hydronephrosis – additional feature of MR urography

    Science.gov (United States)

    Hadjidekov, George; Hadjidekova, Savina; Tonchev, Zahari; Bakalova, Rumiana; Aoki, Ichio

    2011-01-01

    Background Magnetic resonance urography (MRU) is one of the most attractive imaging modalities in paediatric urology, providing largest diagnostic information in a single protocol. Therefore, the aim of our study was to assess the diagnostic value of MRU in children with urogenital anomalies (especially anomalies of the renal pelvis and ureter) and the renal function using different post-processing functional software. Patients and methods Ninety six children (7 days – 18 years old) were examined. In 54 patients of them, a static T2 MRU was completed by excretory T1 MRU after gadolinium administration and functional analysis has been performed using two functional analysis softwares “CHOP-fMRU” and “ImageJ” software. Results MRU showed suspicious renal and the whole urinary tract anomalies with excellent image quality in all children. In ureteropelvic obstruction, MRU was confirmatory to the other imaging techniques, but it was superior modality concerning the evaluation of end-ureteral anomalies. There was an excellent correlation between the MRU data and diagnosis, determined by surgery. The renal transit times, renal volumes and volumetric differential renal function were assessed separately by “CHOP-fMRU” and “ImageJ” with excellent agreement with 99mTc-DTPA and among them. Conclusions MRU overcomes a lot of limitations of conventional imaging modalities and has a potential to become a leading modality in paediatric uroradiology. Synthesis of both anatomical and functional criteria in MR urography enables to select the best candidates for surgical treatment. Even small kidney dysfunction can be detected by functional analysis software. PMID:22933962

  16. Structure and function of nematode communities across the Indian western continental margin and its oxygen minimum zone

    Science.gov (United States)

    Singh, R.; Ingole, B. S.

    2016-01-01

    We studied patterns of nematode distribution along the western Indian continental margin to determine the influence of habitat heterogeneity and low oxygen levels on the community's taxonomic and functional structure. A single transect, perpendicular to the coast at 14° N latitude was sampled from 34 to 2546 m depth for biological and environmental variables during August 2007. The oxygen minimum zone extended from 102 to 1001 m. Nematodes (described and undescribed) were identified to species and classified according to biological and functional traits. A total of 110 nematode species belonging to 24 families were found along the transect. Three depth zones were identified: the shelf (depth range: 34-102 m; highest nematode mean density: 176.6 ± 37 ind 10 cm-2), the slope (525-1524 m; 124.3 ± 16 ind 10 cm-2), and the basin (2001-2546 m; 62.9 ± 2 ind 10 cm-2). Across the entire study area, the dominant species were Terschellingia longicaudata, Desmodora sp. 1, Sphaerolaimus gracilis, and Theristus ensifer; their maximum density was at shelf stations. Nematode communities in different zones differed in species composition. Chromadorita sp. 2 (2.78 %) and Sphaerolaimus gracilis (2.21 %) were dominant on the shelf, whereas Terschellingia longicaudata (4.73 %) and Desmodora sp. 1 (4.42 %) were dominant on the slope, but in the basin, Halalaimus sp. 1(1.11 %) and Acantholaimus elegans (1.11 %) were dominant. The information in a particular functional group was not a simple reflection of the information in species abundance. Ecological information captured by adult length, adult shape, and life-history strategy was less site-specific and thus differed notably from information contained in other taxonomic groups. The functional composition of nematodes was strongly linked to the organic-carbon and dissolved-oxygen concentration. Seven species were found exclusively in the oxygen minimum zone: Pselionema sp. 1, Choanolaimus sp. 2, Halichoanolaimus sp. 1, Cobbia dentata

  17. On the Mathematical Nature of Guseinov's Rearranged One-Range Addition Theorems for Slater-Type Functions

    CERN Document Server

    Weniger, Ernst Joachim

    2011-01-01

    Starting from one-range addition theorems for Slater-type functions, which are expansion in terms of complete and orthonormal functions based on the generalized Laguerre polynomials, Guseinov constructed addition theorems that are expansions in terms of Slater-type functions with a common scaling parameter and integral principal quantum numbers. This was accomplished by expressing the complete and orthonormal Laguerre-type functions as finite linear combinations of Slater-type functions and by rearranging the order of the nested summations. Essentially, this corresponds to the transformation of a Laguerre expansion, which in general only converges in the mean, to a power series, which converges pointwise. Such a transformation is not necessarily legitimate, and this contribution discusses in detail the difference between truncated expansions and the infinite series that result in the absence of truncation

  18. Meaning and Function of Dummy Auxiliaries in Adult Acquisition of Dutch as an Additional Language

    Science.gov (United States)

    Julien, Manuela; van Hout, Roeland; van de Craats, Ineke

    2016-01-01

    This article presents the results of experimental data on language production and comprehension. These show that adult learners of Dutch as an additional language, with different language backgrounds, and a L2 proficiency below level A2 (Waystage) of the Common European Framework of Reference for Languages (CEFR; Council of Europe, 2001), use…

  19. Flame Retardancy of Chemically Modified Lignin as Functional Additive to Epoxy Nanocomposites

    Science.gov (United States)

    John A. Howarter; Gamini P. Mendis; Alex N. Bruce; Jeffrey P. Youngblood; Mark A. Dietenberger; Laura Hasburgh

    2015-01-01

    Epoxy printed circuit boards are used in a variety of electronics applications as rigid, thermally stable substrates. Due to the propensity of components on the boards, such as batteries and interconnects, to fail and ignite the epoxy, flame retardant additives are required to minimize fire risk. Currently, industry uses brominated flame retardants, such as TBBPA, to...

  20. Butorphanol with oxygen insufflation improves cardiorespiratory function in field-immobilised white rhinoceros (Ceratotherium simum

    Directory of Open Access Journals (Sweden)

    Anna Haw

    2015-03-01

    Full Text Available Opioid-induced immobilisation results in severe respiratory compromise in the white rhinoceros (Ceratotherium simum. The effectiveness of oxygen insufflation combined with butorphanol in alleviating respiratory depression in free-ranging chemically immobilised white rhinoceroses was investigated. In this prospective intervention study 14 freeranging white rhinoceroses were immobilised with a combination of etorphine, azaperone and hyaluronidase. Six minutes (min after the animals became recumbent, intravenous butorphanol was administered and oxygen insufflation was initiated. Previous boma trial results were used for comparison, using repeated measures two-way analysis of variance. The initial immobilisation-induced hypoxaemia in free-ranging rhinoceroses (arterial partial pressure of oxygen [PaO2] 35.4 mmHg ± 6.6 mmHg was similar to that observed in bomaconfined rhinoceroses (PaO2 31 mmHg ± 6 mmHg, n = 8. Although the initial hypercapnia (PaCO2 63.0 mmHg ± 7.5 mmHg was not as severe as that in animals in the boma trial (79 mmHg ± 7 mmHg, the field-immobilised rhinoceroses were more acidaemic (pH 7.10 ± 0.14 at the beginning of the immobilisation compared with boma-immobilised rhinoceroses (pH 7.28 ± 0.04. Compared with pre-intervention values, butorphanol with oxygen insufflation improved the PaO2 (81.2 mmHg ± 23.7 mmHg, p < 0.001, 5 min vs 20 min, arterial partial pressure of carbon dioxide (55.3 mmHg ± 5.2 mmHg, p < 0.01, 5 min vs 20 min, pH (7.17 ± 0.11, p < 0.001, 5 min vs 20 min, heart rate (78 breaths/min ± 20 breaths/min, p < 0.001, 5 min vs 20 min and mean arterial blood pressure (105 mmHg ± 14 mmHg, p < 0.01, 5 min vs 20 min. Oxygen insufflation combined with a single intravenous dose of butorphanol improved oxygenation and reduced hypercapnia and acidaemia in immobilised free-ranging white rhinoceroses.

  1. Using Additional Analyses to Clarify the Functions of Problem Behavior: An Analysis of Two Cases

    Science.gov (United States)

    Payne, Steven W.; Dozier, Claudia L.; Neidert, Pamela L.; Jowett, Erica S.; Newquist, Matthew H.

    2014-01-01

    Functional analyses (FA) have proven useful for identifying contingencies that influence problem behavior. Research has shown that some problem behavior may only occur in specific contexts or be influenced by multiple or idiosyncratic variables. When these contexts or sources of influence are not assessed in an FA, further assessment may be…

  2. Academic and Social Achievement Goals: Their Additive, Interactive, and Specialized Effects on School Functioning

    Science.gov (United States)

    Liem, Gregory Arief D.

    2016-01-01

    Background: Students' pursuit of academic and social goals has implications for school functioning. However, studies on academic and social achievement goals have been relatively independent and mainly conducted with students in culturally Western settings. Aims: Guided by multiple-goal perspectives, this study examined the role of academic and…

  3. Conjugate Addition of Nucleophiles to the Vinyl Function of 2-Chloro-4-vinylpyrimidine Derivatives

    Directory of Open Access Journals (Sweden)

    Lucjan Strekowski

    2010-03-01

    Full Text Available Conjugate addition reaction of various nucleophiles across the vinyl group of 2-chloro-4-vinylpyrimidine, 2-chloro-4-(1-phenylvinylpyrimidine and 2-chloro-4-vinylquinazoline provides the corresponding 2-chloro-4-(2-substituted ethylpyrimidines and 2-chloro-4-(2-substituted ethylquinazolines. Treatment of these products, without isolation, with N-methylpiperazine results in nucleophilic displacement of chloride and yields the corresponding 2,4-disubstituted pyrimidines and quinazolines.

  4. Complex esthetic and functional rehabilitation with an additive, minimally invasive restorative approach.

    Science.gov (United States)

    Ho, Christopher Ck

    2014-06-01

    Historically, the management of patients presenting with extensive tooth wear comprised the use of conventional fixed prosthodontics, an approach that often entailed invasive dentistry and increased biomechanical risk. With the development of adhesive bonding, a dentition can be restored in a much more conservative manner using an additive approach. This case report describes the concepts employed in a complex rehabilitation involving tooth erosion, applying both direct and indirect restorations with minimal biological risk to the patient.

  5. Electrocatalytic reduction of oxygen at ordered mesoporous carbon functionalized with tetrathiafulvalene.

    Science.gov (United States)

    Ndamanisha, Jean Chrysostome; Bo, Xiangjie; Guo, Liping

    2010-03-01

    A novel ordered mesoporous carbon-tetrathiafulvalene composite is synthesized. It is based on host-guest chemistry which utilizes synergic interactions between a nanostructured matrix of ordered mesoporous carbon (OMC) and the excellent electron donor properties of tetrathiafulvalene (TTF). It has been found that some interesting properties of OMC are improved. Especially the density of the edge plane-like defective sites, important groups responsible for the electrocatalytic activity towards some molecules, is increased on OMC-TTF composite. Moreover, this new material can be used to facilitate the heterogeneous electron transfer process. OMC-TTF was used, for the first time, to investigate the electrocatalytic reduction of oxygen. The results show that the electrocatalytic behavior of OMC-TTF is attributed to the unique physico-chemical properties of OMC and TTF. At the OMC-TTF modified electrode, the reduction proceeds by the direct four-electron pathway whereas at the OMC electrode the process is not direct. In order to show that the ability of OMC-TTF to promote the electron transfer can allow the application of this composite in many domains, an amperometric oxygen biosensor has been constructed based on OMC-TTF. It exhibits good response to dissolved oxygen with a large linear range and a very low detection limit. The interferences of ascorbic acid and uric acid are suppressed and the applied potential is positive enough to avoid perturbations of other electrochemically reducible compounds. The results above suggest that OMC-TTF has potential applications in the detection of dissolved oxygen and interesting properties of this composite may open up a new approach to study the electrochemical behavior of other biomolecules.

  6. High-surface-area, dual-function oxygen electrocatalysts for space power applications

    Science.gov (United States)

    Ham, David O.; Moniz, Gary; Taylor, E. Jennings

    1987-01-01

    The processes of hydration/dehydration and carbonation/decarbonation are investigated as an approach to provide higher surface area mixed metal oxides that are more active electrochemically. These materials are candidates for use as electrocatalysts and electrocatalyst supports for alkaline electrolyzers and fuel cells. For the case of the perovskite, LaCoO3 , higher surface areas were achieved with no change in structure and a more active oxygen electrocatalyst.

  7. Expression of carotenogenic genes and astaxanthin production in Xanthophyllomyces dendrorhous as a function of oxygen tension.

    Science.gov (United States)

    Wu, Wei; Lu, Mingbo; Yu, Longjiang

    2011-01-01

    This report gives an insight into the specific changes in the transcription of four key carotenogenic genes [encoding geranylgeranyl diphosphate synthase (crtE), phytoene desaturase (crtI), phytoene synthase lycopene cyclase (crtYB), and astaxanthin synthase (ast), respectively] in Xanthophyllomyces dendrorhous cultures, with regard to dissolved oxygen (DO) contents of 10%, 25%, and 40% air saturation, respectively. 25% DO proved to be the most beneficial for yeast growth, transcription of carotenogenic genes, and astaxanthin content.

  8. Effects of Intensified Vasodilatory Antihypertensive Treatment on Renal Function, Blood supply and Oxygenation in Chronic Kidney Disease

    DEFF Research Database (Denmark)

    Khatir, Dinah Sherzad; Pedersen, Michael; Ivarsen, Per

    2015-01-01

    Background: Progression of Chronic kidney disease (CKD) may result from tissue hypoxia induced by small artery structural narrowing, with increased renal vascular resistance (RVR) and impaired blood supply. We investigated whether vasodilating therapy (VT) is superior to non-vasodilating therapy...... (nonVT) for improvement of RVR, tissue oxygenation, and preservation of kidney function. Methods: Eighty-two hypertensive grade 3-4 CKD patients (glomerular filtration rate (GFR) 36±15 ml/min/1.73 m2) were randomised to renin-angiotensin inhibition combined with either VT (amlodipine) or nonVT (beta......-blocker metoprolol). At baseline and following 18 months of therapy we determined forearm resistance by venous occlusion plethysmography. Using magnetic resonance imaging (MRI) renal artery blood flow was measured for calculation of RVR, and blood oxygen level dependent (BOLD) MRI was used as a marker of renal...

  9. Density functional study of NO adsorption on undefected and oxygen defective Au–BaO(1 0 0) surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Añez, Rafael, E-mail: ranez@ivic.gob.ve [Laboratorio de Química Física y Catálisis Computacional, Centro de Química, Instituto Venezolano de Investigaciones Científicas, Apartado, 21827 Caracas (Venezuela, Bolivarian Republic of); Sierraalta, Aníbal; Bastardo, Anelisse [Laboratorio de Química Física y Catálisis Computacional, Centro de Química, Instituto Venezolano de Investigaciones Científicas, Apartado, 21827 Caracas (Venezuela, Bolivarian Republic of); Coll, David [Laboratorio de Físico Química Teórica de Materiales, Centro de Química, Instituto Venezolano de Investigaciones Científicas, Apartado, 21827 Caracas (Venezuela, Bolivarian Republic of); Garcia, Belkis [Instituto Universitario de Tecnología de Valencia IUTVAL, Valencia, Edo. Carabobo (Venezuela, Bolivarian Republic of)

    2014-07-01

    A periodic density functional approach has been used in order to explore the interaction of NO with undoped and Au doped BaO(1 0 0) surface. Due to oxygen vacancies increase the interaction between the doping metal and the surface, F{sub S} and F{sub S}{sup +} vacancies were studied and compared with the results obtained on the undefected doped BaO(1 0 0). Our results indicate that the high basicity of the BaO surface, besides the electron density changes produced by the oxygen vacancies, modify considerably how the Au atom interacts with the surface increasing the ionic character of the interaction. F{sub S} vacancy shows to be a promise center to activate de NO bond on the BaO(1 0 0) surface.

  10. Iron-oxygen vacancy defect centers in PbTi O3 : Newman superposition model analysis and density functional calculations

    Science.gov (United States)

    Meštrić, H.; Eichel, R.-A.; Kloss, T.; Dinse, K.-P.; Laubach, So.; Laubach, St.; Schmidt, P. C.; Schönau, K. A.; Knapp, M.; Ehrenberg, H.

    2005-04-01

    The Fe3+ center in ferroelectric PbTiO3 together with an oxygen vacancy forms a charged defect associate, oriented along the crystallographic c axis. Its microscopic structure has been analyzed in detail comparing results from a semiempirical Newman superposition model analysis based on fine-structure data and from calculations using density functional theory. Both methods give evidence for a substitution of Fe3+ for Ti4+ as an acceptor center. The position of the iron ion in the ferroelectric phase is found to be similar to the B site in the paraelectric phase. Partial charge compensation is locally provided by a directly coordinated oxygen vacancy. Using high-resolution synchrotron powder diffraction, it was verified that lead titanate remains tetragonal down to 12K , exhibiting a c/a ratio of 1.0721.

  11. l-Theanine as a Functional Food Additive: Its Role in Disease Prevention and Health Promotion

    Directory of Open Access Journals (Sweden)

    Jackson Williams

    2016-05-01

    Full Text Available Tea has been consumed for thousands of years and is an integral part of people’s daily routine, as an everyday drink and a therapeutic aid for health promotion. Consumption of tea has been linked to a sense of relaxation commonly associated with the content of the non-proteinogenic amino acid theanine, which is found within the tea leaves. The aim of this review article is to outline the current methods for synthesis, extraction and purification of theanine, as well as to examine its potential benefits related to human health. These include improvements in cognitive and immune function, cancer prevention, reduced cardiovascular risk and its potential usefulness as a functional food product.

  12. [Parameters of oxygen uptake and carbon dioxide output ventilatory efficiency during exercise are index of circulatory function in normal subjects].

    Science.gov (United States)

    Sun, Xingguo; Wang, Guizhi; Lyu, Jing; Tan, Xiaoyue; William, W Stringer; Karlman, Wasserman

    2014-12-01

    To observe oxygen uptake efficiency plateau (OUEP, i.e.highest V˙O2/V˙E) and carbon dioxide output efficiency (lowest V˙E/V˙CO2) parameter changes during exercise in normal subjects. Five healthy volunteers performed the symptom limited maximal cardiopulmonary exercise test (CPET) at Harbor-UCLA Medical Center. V˙O2/V˙E and V˙E/V˙CO2 were determined by both arterial and central venous catheters. After blood gas analysis of arterial and venous sampling at the last 30 seconds of every exercise stage and every minute of incremental loading, the continuous parameter changes of hemodynamics, pulmonary ventilation were monitored and oxygen uptake ventilatory efficiency (V˙O2/V˙E and V˙E/V˙CO2) was calculated. During CPET, as the loading gradually increased, cardiac output, heart rate, mixed venous oxygen saturation, arteriovenous oxygen difference, minute ventilation, minute alveolar ventilation, tidal volume, alveolar ventilation and pulmonary ventilation perfusion ratio increased near-linearly (P change (P > 0.05); stroke volume, respiratory rate, arterial partial pressure of carbon dioxide, arterial blood hydrogen ion concentration and dead space ventilation ratio significantly changed none-linearly (compare resting state P exercise increased from 30.9 ± 3.3 at resting state to the highest plateau 46.0 ± 4.7 (P exercise. The V˙E/V˙CO2 during exercise decreased from the resting state (39.2 ± 6.5) to the minimum value (24.2 ± 2.4) after AT for a few minutes (P > 0.05 vs.earlier stage), then gradually increased after the ventilatory compensation point (P exercise. Cardiac and lung function as well as metabolism change during CPET is synchronous.In the absence of pulmonary limit, appearing before and after anaerobic threshold, OUEP and lowest V˙E/V˙CO2 could be used as reliable parameters representing the circulatory function.

  13. Dual Function Additives: A Small Molecule Crosslinker for Enhanced Efficiency and Stability in Organic Solar Cells

    KAUST Repository

    Rumer, Joseph W.

    2015-02-01

    A bis-azide-based small molecule crosslinker is synthesized and evaluated as both a stabilizing and efficiency-boosting additive in bulk heterojunction organic photovoltaic cells. Activated by a noninvasive and scalable solution processing technique, polymer:fullerene blends exhibit improved thermal stability with suppressed polymer skin formation at the cathode and frustrated fullerene aggregation on ageing, with initial efficiency increased from 6% to 7%. © 2015 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Oxygen flux and dielectric response study of Mixed Ionic-Electronic Conducting (MIEC) heterogeneous functional materials

    Science.gov (United States)

    Rabbi, Fazle

    Dense mixed ionic-electronic conducting (MIEC) membranes consisting of ionic conductive perovskite-type and/or fluorite-type oxides and high electronic conductive spinel type oxides, at elevated temperature can play a useful role in a number of energy conversion related systems including the solid oxide fuel cell (SOFC), oxygen separation and permeation membranes, partial oxidization membrane reactors for natural gas processing, high temperature electrolysis cells, and others. This study will investigate the impact of different heterogeneous characteristics of dual phase ionic and electronic conductive oxygen separation membranes on their transport mechanisms, in an attempt to develop a foundation for the rational design of such membranes. The dielectric behavior of a material can be an indicator for MIEC performance and can be incorporated into computational models of MIEC membranes in order to optimize the composition, microstructure, and ultimately predict long term membrane performance. The dielectric behavior of the MIECs can also be an indicator of the transport mechanisms and the parameters they are dependent upon. For this study we chose a dual phase MIEC oxygen separation membrane consisting of an ionic conducting phase: gadolinium doped ceria-Ce0.8 Gd0.2O2 (GDC) and an electronic conductive phase: cobalt ferrite-CoFe2O4 (CFO). The membranes were fabricated from mixtures of Nano-powder of each of the phases for different volume percentages, sintered with various temperatures and sintering time to form systematic micro-structural variations, and characterized by structural analysis (XRD), and micro-structural analysis (SEM-EDS). Performance of the membranes was tested for variable partial pressures of oxygen across the membrane at temperatures from 850°C-1060°C using a Gas Chromatography (GC) system. Permeated oxygen did not directly correlate with change in percent mixture. An intermediate mixture 60%GDC-40%CFO had the highest flux compared to the 50%GDC

  15. The effect of additional resistance of air flow on the functioning parameters of the highly qualified rowers' outer respiration

    Directory of Open Access Journals (Sweden)

    Grechuha S.V.

    2010-03-01

    Full Text Available Influence of additional resistance the current of air is rotined on the feature of functioning of the system of the external breathing of sportsmen. In experiment 12 sportsmen took part 17-25 years. All sportsmen are candidates or sport masters. Experience of employments of sportsmen made 4-12 years. Tests were conducted in a preparatory period of annual cycle of training. The dynamics of changes speed of current of air is presented, ventilations of lights at peace and at the dosed physical loading. More effective for development of functional possibilities of respiratory muscles for sportsmen it is possible to count application of additional resistance on exhalation.

  16. Functional multiparametric magnetic resonance imaging of the kidneys using blood oxygen level dependent and diffusion-weighted sequences.

    Science.gov (United States)

    Giannarini, Gianluca; Kessler, Thomas M; Roth, Beat; Vermathen, Peter; Thoeny, Harriet C

    2014-08-01

    Little data are available on noninvasive magnetic resonance imaging based assessment of renal function during upper urinary tract obstruction. We determined whether functional multiparametric kidney magnetic resonance imaging could monitor the treatment response in cases of acute unilateral upper urinary tract obstruction. Between January 2008 and January 2010, 18 patients with acute unilateral upper urinary tract obstruction due to calculi were prospectively enrolled to undergo kidney magnetic resonance imaging with conventional, blood oxygen level dependent and diffusion-weighted sequences upon emergency hospital admission and after release of obstruction. We assessed functional imaging parameters of obstructed and contralateral unobstructed kidneys derived from blood oxygen level dependent (apparent spin relaxation rate) and diffusion-weighted (total apparent diffusion coefficient, pure diffusion coefficient and perfusion fraction) sequences during acute upper urinary tract obstruction and after its release. During acute obstruction the apparent spin relaxation rate and perfusion fraction were lower in the cortex (p=0.020 and 0.031) and medulla (p=0.012 and 0.190, respectively) of obstructed kidneys compared to contralateral unobstructed kidneys. After obstruction release the apparent spin relaxation rate and perfusion fraction increased in the cortex (p=0.016 and 0.004) and medulla (p=0.071 and 0.044, respectively) of formerly obstructed kidneys to values similar to those in contralateral kidneys. Total apparent diffusion coefficient and pure diffusion coefficient values did not significantly differ between obstructed and contralateral unobstructed kidneys during or after obstruction. In our patients with acute unilateral upper urinary tract obstruction due to calculi functional kidney magnetic resonance imaging using blood oxygen level dependent and diffusion-weighted sequences enabled us to monitor pathophysiological changes in obstructed kidneys during

  17. Comparing Heparin-Coated and Non-Coated Oxygenators on Renal Functions in Coronary Artery Bypass Surgery

    Directory of Open Access Journals (Sweden)

    Bektaş Battaloğlu

    2011-04-01

    Full Text Available Background: Renal damage and subsequent acute renal failure is one of the most important complications in patients who had cardiac surgery. Multicenter studies with thousands of patients which exposed the risk factors for acute renal failure has been published especially in the last decade. This study is designed for evaluation of heparin-coated and non-coated oxygenators on the renal functions. Methods: This study has been performed prospectively with 50 patients who had undergone coronary bypass surgery in our clinic from March 2006 to September 2006. The patients have been divided into two groups as non-coated oxygenators (n = 25, Group 1 used and heparin-coated oxygenators (n = 25, Group 2 used. Blood samples were collected at the preoperative, and at 1st, 24th and 96th postoperative hours. The demographic data were similar in two groups. Results: There was no early mortality in both groups. Operative and postoperative parameters were similar in both groups. There were no statistical differences between the evaluated parameters like BUN, creatinine, sodium, potassium, calcium, chloride, phosphorus, urine protein, creatinine clearence, urine sodium, urine calcium and urine chloride tests at preoperative period in both groups. We did not detect renal dysfunction in any patients. There are no statistical differences in the creatinine clearance in preoperative and postoperative periods in both groups. In group one, creatinin levels were lower than group two at 24 hours after surgery and these differences were statistically important in two groups. We found no significant difference between two groups regarding the other parameters for renal function during the postoperative period. Conclusion: In this study, there were not any significant difference between coated and non-coated oxygenators’ effects over renal functions of patients whose renal functions were normal preoperatively.

  18. Evaluating the Addition of a Dinoflagellate Phytoplankton Functional Type Using Radiance Anomalies for Monterey Bay, CA

    Science.gov (United States)

    Houskeeper, H. F.; Kudela, R. M.

    2016-12-01

    Ocean color sensors have enabled daily, global monitoring of phytoplankton productivity in the world's oceans. However, to observe key structures such as food webs, or to identify regime shifts of dominant species, tools capable of distinguishing between phytoplankton functional types using satellite remote sensing reflectance are necessary. One such tool developed by Alvain et al. (2005), PHYSAT, successfully linked four phytoplankton functional types to chlorophyll-normalized remote sensing spectra, or radiance anomalies, in case-1 waters. Yet this tool was unable to characterize dinoflagellates because of their ubiquitous background presence in the open ocean. We employ a radiance anomaly technique based on PHYSAT to target phytoplankton functional types in Monterey Bay, a region where dinoflagellate populations are larger and more variable than in open ocean waters, and thus where they may be viable targets for satellite remote sensing characterization. We compare with an existing Santa Cruz Wharf photo-pigment time series spanning from 2006 to the present to regionally ground-truth the method's predictions, and we assess its accuracy in characterizing dinoflagellates, a phytoplankton group that impacts the region's fish stocks and water quality. For example, an increase in dinoflagellate abundance beginning in 2005 led to declines in commercially important fish stocks that persisted throughout the following year. Certain species of dinoflagellates in Monterey Bay are also responsible for some of the harmful algal bloom events that negatively impact the shellfish industry. Moving toward better tools to characterize phytoplankton blooms is important for understanding ecosystem shifts, as well as protecting human health in the surrounding areas.

  19. Cerebral oxygen delivery and consumption during evoked neural activity

    Directory of Open Access Journals (Sweden)

    Alberto L Vazquez

    2010-06-01

    Full Text Available Increases in neural activity evoke increases in the delivery and consumption of oxygen. Beyond observations of cerebral tissue and blood oxygen, the role and properties of cerebral oxygen delivery and consumption during changes in brain function are not well understood. This work overviews the current knowledge of functional oxygen delivery and consumption and introduces recent and preliminary findings to explore the mechanisms by which oxygen is delivered to tissue as well as the temporal dynamics of oxygen metabolism. Vascular oxygen tension measurements have shown that a relatively large amount of oxygen exits pial arterioles prior to capillaries. Additionally, increases in cerebral blood flow (CBF induced by evoked neural activation are accompanied by arterial vasodilation and also by increases in arteriolar oxygenation. This increase contributes not only to the down-stream delivery of oxygen to tissue, but also to delivery of additional oxygen to extra-vascular spaces surrounding the arterioles. On the other hand, the changes in tissue oxygen tension due to functional increases in oxygen consumption have been investigated using a method to suppress the evoked CBF response. The functional decreases in tissue oxygen tension induced by increases in oxygen consumption are slow to evoked changes in CBF under control conditions. Preliminary findings obtained using flavoprotein autofluorescence imaging suggest cellular oxidative metabolism changes at a faster rate than the average changes in tissue oxygen. These issues are important in the determination of the dynamic changes in tissue oxygen metabolism from hemoglobin-based imaging techniques such as blood oxygenation-level dependent functional magnetic resonance imaging (fMRI.

  20. Differential expression of functional Fc-receptors and additional immune complex receptors on mouse kidney cells.

    Science.gov (United States)

    Suwanichkul, Adisak; Wenderfer, Scott E

    2013-12-01

    The precise mechanisms by which circulating immune complexes accumulate in the kidney to form deposits in glomerulonephritis are not well understood. In particular, the role of resident cells within glomeruli of the kidney has been widely debated. Immune complexes have been shown to bind one glomerular cell type (mesangial cells) leading to functional responses such as pro-inflammatory cytokine production. To further assess the presence of functional immunoreceptors on resident glomerular cells, cultured mouse renal epithelial, endothelial, and mesangial cells were treated with heat-aggregated mouse IgG or preformed murine immune complexes. Mesangial and renal endothelial cells were found to bind IgG complexes, whereas glomerular epithelial cell binding was minimal. A blocking antibody for Fc-gamma receptors reduced binding to mesangial cells but not renal endothelial cells, suggesting differential immunoreceptor utilization. RT-PCR and immunostaining based screening of cultured renal endothelial cells showed limited low-level expression of known Fc-receptors and Ig binding proteins. The interaction between mesangial cells and renal endothelial cells and immune complexes resulted in distinct, cell-specific patterns of chemokine and cytokine production. This novel pathway involving renal endothelial cells likely contributes to the predilection of circulating immune complex accumulation within the kidney and to the inflammatory responses that drive kidney injury.

  1. Effect of hyperbaric oxygen combined withα-lipoic acid on neurological function and serum indexes of patients with diabetic peripheral neuropathy

    Institute of Scientific and Technical Information of China (English)

    Yu Li; Ling Qi; Jun Li

    2016-01-01

    Objective:To analyze the effect of hyperbaric oxygen combined withα-lipoic acid on neurological function and serum indexes of patients with diabetic peripheral neuropathy. Methods:A total of 118 diabetic peripheral neuropathy patients who received treatment in our hospital were selected as research subjects, and according to the different clinical treatment they received, all included patients were divided into observation group 59 cases and control group 59 cases. Control group received conventional clinical treatment, and observation group received additional hyperbaric oxygen combined withα-lipoic acid treatment. Differences in nerve conduction velocity, gastrocnemius nerve threshold, illness-related factors, oxidative stress indicator values, and so on were compared between two groups after treatment.Results:MCV and SCV values of median nerve, ulnar nerve and tibial nerve of observation group after treatment were higher than those of control group (P<0.05); gastrocnemius nerve threshold of observation group after treatment were significantly lower than those of control group (P<0.05); serum CP and BDNF values of observation group after treatment were higher than those of control group while Cys-C, SDF-1α, HMGB1 and MBP values were lower than those of control group (P<0.05); serum MDA and NO values of observation group after treatment were lower than those of control group while SOD, CAT and GSH-Px values were higher than those of control group (P<0.05).Conclusions:Hyperbaric oxygen combined withα-lipoic acid is a good method to optimize the neurological function and improve overall illness of patients with diabetic peripheral neuropathy, and is expected to become a new way of inhibiting disease progression and improving disease outcome.

  2. Aim at the bottom: directly exciting the lower level of a laser transition for additional functionality.

    Science.gov (United States)

    Iwanus, Nikolas; Hudson, Darren D; Hu, Tomonori; Jackson, Stuart D

    2014-03-01

    We introduce the concept of directly exciting the lower level of a laser transition in addition to the upper laser level for the provision of new possibilities for light emission from a fiber. In a first demonstration, using diode laser light at 1150 and 1950 nm, we respectively excite the upper and lower laser level of the 5I(6)→5I(7) transition (2.9 μm) of Ho3+-doped ZBLAN, demonstrating a power-scalable arrangement that can switch between free-running and superluminescent spectral output. The spectral composition of the gain-switched pulse derived from modulating the upper laser level pump light depends entirely on the degree of lower laser level excitation at 1950 nm.

  3. Titanium-Based Hip Stems with Drug Delivery Functionality through Additive Manufacturing.

    Science.gov (United States)

    Bezuidenhout, Martin B; Dimitrov, Dimitar M; van Staden, Anton D; Oosthuizen, Gert A; Dicks, Leon M T

    2015-01-01

    Postoperative infections are a major concern in patients that receive implants. These infections generally occur in areas with poor blood flow and pathogens do not always respond to antibiotic treatment. With the latest developments in nanotechnology, the incorporation of antibiotics into prosthetic implants may soon become a standard procedure. The success will, however, depend on the ability to control the release of antibiotics at concentrations high enough to prevent the development of antibiotic-resistant strains. Through additive manufacturing, antibiotics can be incorporated into cementless femoral stems to produce prosthetic devices with antimicrobial properties. With the emerging increase in resistance to antibiotics, the incorporation of antimicrobial compounds other than antibiotics, preferably drugs with a broader spectrum of antimicrobial activity, will have to be explored. This review highlights the microorganisms associated with total hip arthroplasty (THA), discusses the advantages and disadvantages of the latest materials used in hip implants, compares different antimicrobial agents that could be incorporated, and addresses novel ideas for future research.

  4. Organic-inorganic hybrid foams with diatomite addition: Effect on functional properties

    Science.gov (United States)

    Verdolotti, L.; D'Auria, M.; Lavorgna, M.; Vollaro, P.; Iannace, S.; Capasso, I.; Galzerano, B.; Caputo, D.; Liguori, B.

    2016-05-01

    Organic-inorganic hybrid foams were prepared by using metakaolin, diatomite as a partial (or total) replacement of metakaolin, as matrix, silicon and whipped protein as pore forming. The foamed systems were hardened at defined temperature and time and then characterized by mechanical point of view through compression tests and by functional point of view through fire reaction and acoustic tests. The experimental findings highlighted that the replacement of diatomite in the formulation affected the morphological structure of the foams and consequently their mechanical properties. In particular, the consolidation mechanism in the diatomite based-hybrid foams changed from geopolymerization to a silicate polycondensation mechanism. Therefore, mechanical performances enhanced with increasing of the diatomite content. Fire reaction tests, such as non-combustibility and cone calorimeter tests, showed positive thermal inertia of samples regardless of the content of diatomite.

  5. Work-function oscillations during the surfactant induced layer-by-layer growth of copper on oxygen precovered Ru(0001)

    Science.gov (United States)

    Schmidt, M.; Wolter, H.; Wandelt, K.

    1994-04-01

    In the present work the Cu-film growth on a clean and an oxygen precovered Ru(0001) surface, as monitored with dynamical work function measurements (ΔΦ measurements) during the Cu evaporation using a special Kelvin-probe is compared. For Cu adsorption on the clean surface the observed temperature dependence of the ΔΦ measurements is understood in terms of a change of the growth structure of the Cu films from layer-by-layer growth up to ~ 3 ML at ~ 600 K to a 3D-growth mode at ~ 400 K. In turn, as recently reported, in the case of Cu adsorption on the oxygen-precovered surface at ~ 400 K remarkable ΔΦ oscillations are observed, which could be resolved over many periods clearly indicating a layer-wise growth of high quality at this temperature. Furthermore, in the present paper we report on new and detailed results about the dependence of the ΔΦ oscillations on the oxygen precoverage as well as the Cu deposition rate.

  6. Generalized Hyers-Ulam Stability of a General Mixed Additive-cubic Functional Equation in Quasi-Banach Spaces

    Institute of Scientific and Technical Information of China (English)

    Tian Zhou XU; John Michael RASSIAS; Wan Xin XU

    2012-01-01

    In this paper,we establish a general solution and the generalized Hyers-Ulam-Rassias stability of the following general mixed additive-cubic functional equation f(kx + y) + f(kx - y) =kf(x + y) + kf(x - y) + 2f(kx) - 2kf(x)in the quasi-Banach spaces.

  7. Titanium-Based Hip Stems with Drug Delivery Functionality through Additive Manufacturing

    Directory of Open Access Journals (Sweden)

    Martin B. Bezuidenhout

    2015-01-01

    Full Text Available Postoperative infections are a major concern in patients that receive implants. These infections generally occur in areas with poor blood flow and pathogens do not always respond to antibiotic treatment. With the latest developments in nanotechnology, the incorporation of antibiotics into prosthetic implants may soon become a standard procedure. The success will, however, depend on the ability to control the release of antibiotics at concentrations high enough to prevent the development of antibiotic-resistant strains. Through additive manufacturing, antibiotics can be incorporated into cementless femoral stems to produce prosthetic devices with antimicrobial properties. With the emerging increase in resistance to antibiotics, the incorporation of antimicrobial compounds other than antibiotics, preferably drugs with a broader spectrum of antimicrobial activity, will have to be explored. This review highlights the microorganisms associated with total hip arthroplasty (THA, discusses the advantages and disadvantages of the latest materials used in hip implants, compares different antimicrobial agents that could be incorporated, and addresses novel ideas for future research.

  8. Improvement of attenuation functions of a clayey sandstone for landfill leachate containment by bentonite addition.

    Science.gov (United States)

    Ruiz, Ana I; Fernández, Raúl; Sánchez Jiménez, Nicanor; Rodríguez Rastrero, Manuel; Regadío, Mercedes; de Soto, Isabel S; Cuevas, Jaime

    2012-03-01

    Enhanced sand-clay mixtures have been prepared by using a sandstone arkosic material and have been evaluated for consideration as landfill liners. A lab-scale test was carried out under controlled conditions with different amended natural sandstones whereby leachate was passed through the compacted mixtures. The compacted samples consisted of siliceous sand (quartz-feldspar sand separated from the arkose sandstone) and clay (purified clay from arkose sandstone and two commercial bentonites) materials that were mixed in different proportions. The separation of mineral materials from a common and abundant natural source, for soil protection purposes, is proposed as an economic and environmentally efficient practice. The liner qualities were compared for their mineralogical, physicochemical and major ions transport and adsorption properties. Although all samples fulfilled hydraulic conductivity requirements, the addition of bentonite to arkose sandstone was determined to be an effective strategy to decrease the permeability of the soil and to improve the pollutants retention. The clay materials from arkose sandstone also contributed to pollutant retention by a significant improvement of the cation exchange capacity of the bulk material. However, the mixtures prepared with clay materials from the arkose, exhibited a slight increase of hydraulic conductivity. This effect has to be further evaluated. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Is the structural diversity of tripeptides sufficient for developing functional food additives with satisfactory multiple bioactivities?

    Science.gov (United States)

    Wang, Jian-Hui; Liu, Yong-Le; Ning, Jing-Heng; Yu, Jian; Li, Xiang-Hong; Wang, Fa-Xiang

    2013-05-01

    Multifunctional peptides have attracted increasing attention in the food science community because of their therapeutic potential, low toxicity and rapid intestinal absorption. However, previous study demonstrated that the limited structural variations make it difficult to optimize dipeptide molecules in a good balance between desirable and undesirable properties (F. Tian, P. Zhou, F. Lv, R. Song, Z. Li, J. Pept. Sci. 13 (2007) 549-566). In the present work, we attempt to answer whether the structural diversity is sufficient for a tripeptide to have satisfactory multiple bioactivities. Statistical test, structural examination and energetic analysis confirm that peptides of three amino acids long can bind tightly to human angiotensin converting enzyme (ACE) and thus exert significant antihypertensive efficacy. Further quantitative structure-activity relationship (QSAR) modeling and prediction of all 8000 possible tripeptides reveal that their ACE-inhibitory potency exhibits a good (positive) relationship to antioxidative activity, but has only a quite modest correlation with bitterness. This means that it is possible to find certain tripeptide entities possessing the optimal combination of strong ACE-inhibitory potency, high antioxidative activity and weak bitter taste, which are the promising candidates for developing multifunctional food additives with satisfactory multiple bioactivities. The marked difference between dipeptide and tripeptide can be attributed to the fact that the structural diversity of peptides increases dramatically with a slight change in sequence length.

  10. A functional sulfonic additive for high efficiency and low hysteresis perovskite solar cells

    Science.gov (United States)

    Han, Fei; Luo, Junsheng; Malik, Haseeb Ashraf; Zhao, Bowen; Wan, Zhongquan; Jia, Chunyang

    2017-08-01

    Grain size of MAPbI3 and thickness of mesoporous TiO2 (mp-TiO2) film are found to influence current-voltage (J-V) hysteresis, where the J-V hysteresis is alleviated as grain size increases and thickness of mp-TiO2 varies. In this work, a low-cost and high-efficiency additive 4-methylbenzenesulfonic acid (4-MSA) is introduced into perovskite precursor solution to improve the performances of perovskite solar cells (PSCs) and reduce the device hysteresis. By adjusting 4-MSA concentration, the fabricated PSC shows the best power conversion efficiency (PCE) of 17.58% (Jsc = 23.15 mA cm-2, Voc = 1.04 V and FF = 0.73) and a hysteresis index (HI) of 0.048 with a fixed device area of 0.15 cm2 under illumination of AM 1.5G (100 mW cm-2). The significantly improved device performances maybe due to the fact that the carriers more easily be collected for larger grain sizes and fewer grain boundaries by doping 4-MSA into perovskite precursor solution. Furthermore, the sulfonic group is chemically bonded to mp-TiO2 and phenyl backbone has π-conjugated structure, which benefits electron transfer.

  11. The effect of ageing on ocular blood flow, oxygen tension and retinal function during and after intraocular pressure elevation.

    Directory of Open Access Journals (Sweden)

    Jeremiah K H Lim

    Full Text Available PURPOSE: To investigate the effect of ageing on the recovery of ocular blood flow, intravitreal oxygen tension and retinal function during and after intraocular pressure (IOP elevation. METHODS: Long Evans rats (3- and 14-month-old underwent acute stepwise IOP elevation from 10 to 120 mmHg (5 mmHg steps each 3 minutes. IOP was then returned to baseline and recovery was monitored for 2 hours. Photopic electroretinograms (ERG were recorded at each IOP step during stress and at each minute during recovery. Ocular blood flow and vitreal oxygen tension (pO2 were assayed continuously and simultaneously using a combined laser Doppler flow meter (LDF and an oxygen sensitive fibre-optic probe, respectively. The combined sensor was placed in the vitreous chamber, proximal to the retina. Data were binned into 3 minute intervals during stress and 1 min intervals during recovery. Recovery data was described using a bi-logistic function. RESULTS: Rats of both ages showed similar susceptibility to IOP elevation, with pO2 showing a closer relationship to ERG than LDF. During recovery, both ages showed a distinctive two-phased recovery for all three measures with the exception of the LDF in 3-month-old rats, which showed only 1 phase. In all animals, LDF recovered fastest (1 hour. 14-month-old rats showed surprisingly faster and greater LDF recovery compared to the younger group, with similar levels of pO2 recovery. However, the ERG in these middle-aged animals did not fully recover after two hours, despite showing no difference in susceptibility to IOP during stress compared to the young group. CONCLUSIONS: Young and middle-aged eyes showed similar susceptibility to IOP elevation in terms of pO2, LDF and ERG. Despite this lack of difference during stress, older eyes did not completely recover function, suggesting a more subtle age-related susceptibility to IOP.

  12. Density functional theory studies of the adsorption of ethylene and oxygen on Pt(111) and Pt3Sn(111)

    DEFF Research Database (Denmark)

    Watwe, R.M.; Cortright, R.D.; Mavrikakis, Manos

    2001-01-01

    of pi -bonded ethylene, di-sigma -bonded ethylene, and ethylidyne species are weaker on Pt3Sn(111) than on Pt(111) by 21, 31, and 50 kJ/mol, respectively. Hence, the electronic effect of Sn on the adsorption of ethylene depends on the type of adsorption site, with adsorption on three-fold site weakened......Density functional theory, employing periodic slab calculations, was used to investigate the interactions of ethylene and oxygen with Pt(111) and Pt3Sn(111). The predicted energetics and structures of adsorbed species on Pt(111) are in good agreement with experimental data. The binding energies...

  13. Cytocompatibility studies of vertically-aligned multi-walled carbon nanotubes: Raw material and functionalized by oxygen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Lobo, A.O., E-mail: loboao@yahoo.com [Laboratorio Associado de Sensores e Materiais, INPE, Sao Jose dos Campos/SP (Brazil); Instituto Tecnologico de Aeronautica, ITA, Sao Jose dos Campos/SP (Brazil); Laboratorio de Nanotecnologia Biomedica, Universidade do Vale do Paraiba, Sao Jose dos Campos/SP (Brazil); Corat, M.A.F. [Centro Multidisciplinar para Investigacao Biologica na Area da Ciencia em Animais de Laboratorio, CEMIB, UNICAMP, Campinas/SP (Brazil); Antunes, E.F. [Laboratorio Associado de Sensores e Materiais, INPE, Sao Jose dos Campos/SP (Brazil); Instituto Tecnologico de Aeronautica, ITA, Sao Jose dos Campos/SP (Brazil); Ramos, S.C. [Instituto Tecnologico de Aeronautica, ITA, Sao Jose dos Campos/SP (Brazil); Pacheco-Soares, C. [Laboratorio de Dinamica de Compartimentos Celulares, UNIVAP, Sao Jose dos Campos/SP (Brazil); and others

    2012-05-01

    It was presented a strong difference on cell adhesion and proliferation of functionalized vertically-aligned multi-walled carbon nanotube (VACNT) scaffolds compared to raw-VACNT. Biocompatibility in vitro tests were performed on raw-VACNT after superficial modification by oxygen plasma, which changes its superhydrophobic character to superhydrophilic. Two cytocompatibility tests were applied: 1) total lactate dehydrogenase colorimetric assay for the study of proliferating cells; and 2) cellular adhesion by scanning electron microscopy. Results showed that superhydrophilic VACNT scaffolds stimulate cell growth with proliferation up to 70% higher than normal growth of cell culture.

  14. Electrocatalytic activity of alkyne-functionalized AgAu alloy nanoparticles for oxygen reduction in alkaline media

    Science.gov (United States)

    Hu, Peiguang; Song, Yang; Chen, Limei; Chen, Shaowei

    2015-05-01

    1-Dodecyne-functionalized AgAu alloy nanoparticles were synthesized by chemical reduction of metal salt precursors at varied initial feed ratios. Transmission electron microscopic measurements showed that the nanoparticles were all rather well dispersed with the average core diameter in the narrow range of 3 to 5 nm. X-ray photoelectron spectroscopic studies confirmed the formation of AgAu alloy nanoparticles with the gold concentration ranging from approximately 25 at% to 55 at%. Consistent results were obtained in UV-vis spectroscopic measurements where the nanoparticle surface plasmon resonance red-shifted almost linearly with increasing gold concentrations. The self-assembly of 1-dodecyne ligands on the nanoparticle surface was manifested in infrared spectroscopic measurements. Importantly, the resulting nanoparticles exhibited apparent electrocatalytic activity for oxygen reduction in alkaline media, and the performance was found to show a volcano variation in the Au content in the alloy nanoparticles, with the best performance observed for the samples with ca. 35.5 at% Au. The enhanced catalytic activity, as compared to pure Ag nanoparticles or even commercial Pt/C catalysts, was accounted for by the unique metal-ligand interfacial bonding interactions as well as alloying effects that increased metal-oxygen affinity.1-Dodecyne-functionalized AgAu alloy nanoparticles were synthesized by chemical reduction of metal salt precursors at varied initial feed ratios. Transmission electron microscopic measurements showed that the nanoparticles were all rather well dispersed with the average core diameter in the narrow range of 3 to 5 nm. X-ray photoelectron spectroscopic studies confirmed the formation of AgAu alloy nanoparticles with the gold concentration ranging from approximately 25 at% to 55 at%. Consistent results were obtained in UV-vis spectroscopic measurements where the nanoparticle surface plasmon resonance red-shifted almost linearly with increasing gold

  15. Effects of long-term low-dose oxygen supplementation on the epithelial function, collagen metabolism and interstitial fibrogenesis in the guinea pig lung

    National Research Council Canada - National Science Library

    Aoki, Takuya; Yamasawa, Fumihiro; Kawashiro, Takeo; Shibata, Tetsuichi; Ishizaka, Akitoshi; Urano, Tetsuya; Okada, Yasumasa

    2008-01-01

    .... This study was designed to clarify the effects of long-term low-dose oxygen inhalation on pulmonary epithelial function, edema formation, collagen metabolism, and alveolar fibrosis. Guinea pigs (n = 159...

  16. Correlation between single-trial visual evoked potentials and the blood oxygenation level dependent response in simultaneously recorded electroencephalography-functional magnetic resonance imaging

    DEFF Research Database (Denmark)

    Fuglø, Dan; Pedersen, Henrik; Rostrup, Egill

    2012-01-01

    To compare different electroencephalography (EEG)-based regressors and their ability to predict the simultaneously recorded blood oxygenation level dependent response during blocked visual stimulation, simultaneous EEG-functional magnetic resonance imaging in 10 healthy volunteers was performed...

  17. Expression and function of P16 in a rat model of oxygen-induced retinopathy

    Directory of Open Access Journals (Sweden)

    You Li

    2017-02-01

    Full Text Available AIM: To investigate the effect of p16 protein expression on the proliferation of retinal neovascularization in oxygen-induced retinopathy(OIR.METHODS: Totally 60 SD rats aged 7d were randomly divided into 4 groups: normal group, model group, intervention group and NS control group. Normal group was raised in a normal air feeding; model group at 75% high oxygen for 5d to establish the model of oxygen induced retinopathy; intervention group was given anti p16 methylation drug 5-aza-CdR(0.25 mg/kgintraperitoneal injection; NS control group was given the same volume NS intraperitoneal injection. The eyes were taken from each group and the left eyes were removed for observation of retinal neovascularization by HE staining, and immunohistochemistry and immunofluorescence were taken for observations of p16 protein expression. Right retina had been performed real time-PCR to analysis p16mRNA expression. RESULTS: The normal group were not found retinal neovascularization breaking through internal limiting mebrane. In model group and NS control group, the retinal tissue was obviously thickened, and a large number of new blood vessels were found. In the intervention group, a small amount of new blood vessels were found in the retina. The expression of p16 was low in the model group, the positive cell number was 19.52±2.67, and the number of the positive cells was 36.38±3.16 in the intervention group, the difference was statistically significant(P-△△ct=0.14±0.01, the expression of p16 mRNA in the intervention group rats retina was significantly higher than that of NS control group rat retina, there was significant difference between two groups(2-△△ct=0.68±0.08, PCONCLUSION: The abnormal expression of P16 may be closely related to the proliferation of retinal neovascularization. Inhibition of p16 methylation can decrease the proliferation of retinal neovascularization.

  18. Microbial functional diversity alters the structure and sensitivity of oxygen deficient zones

    Science.gov (United States)

    Penn, Justin; Weber, Thomas; Deutsch, Curtis

    2016-09-01

    Oxygen deficient zones (ODZs) below the ocean surface regulate marine productivity by removing bioavailable nitrogen (N). A complex microbial community mediates N loss, but the interplay of its diverse metabolisms is poorly understood. We present an ecosystem model of the North Pacific ODZ that reproduces observed chemical distributions yet predicts different ODZ structure, rates, and climatic sensitivity compared to traditional geochemical models. An emergent lower O2 limit for aerobic nitrification lies below the upper O2 threshold for anaerobic denitrification, creating a zone of microbial coexistence that causes a larger ODZ but slower total rates of N loss. The O2-dependent competition for the intermediate nitrite produces gradients in its oxidation versus reduction, anammox versus heterotrophic denitrification, and the net ecological stoichiometry of N loss. The latter effect implies that an externally driven ODZ expansion should favor communities that more efficiently remove N, increasing the sensitivity of the N cycle to climate change.

  19. Effects of oxygen stress on membrane functions in Escherichia coli: role of HPI catalase

    Energy Technology Data Exchange (ETDEWEB)

    Farr, S.B.; Touati, D.; Kogoma, T.

    1988-04-01

    Different conditions of oxidative stress were used to study their effects on membrane transport in Escherichia coli K-12. The oxidizing conditions included H/sub 2/O/sub 2/, plumbagin (a redox cycling compound that generates superoxide radicals (O/sub 2/-)), and increased partial pressure of oxygen. Both superoxide radical-generating conditions and H/sub 2/O/sub 2/ treatments were found to cause a rapid decrease in proton motive force-dependent and -independent transport. H/sub 2/O/sub 2/-pretreated cells had the ability to rapidly recover both proton motive force-dependent and -independent transport. The induction required transcription and translation and was dependent on oxyR+ and katG+, providing evidence that these genes play crucial roles in the rapid recovery of transport. The effects of oxidatively induced loss of proton motive force on cell growth and macromolecular synthesis were also investigated.

  20. Role of Mitochondrial Reactive Oxygen Species in the Activation of Cellular Signals, Molecules, and Function

    DEFF Research Database (Denmark)

    Indo, Hiroko P.; Hawkins, Clare L; Nakanishi, Ikuo

    2017-01-01

    Mitochondria are a major source of intracellular energy and reactive oxygen species in cells, but are also increasingly being recognized as a controller of cell death. Here, we review evidence of signal transduction control by mitochondrial superoxide generation via the nuclear factor-κB (NF......-κB) and GATA signaling pathways. We have also reviewed the effects of ROS on the activation of MMP and HIF. There is significant evidence to support the hypothesis that mitochondrial superoxide can initiate signaling pathways following transport into the cytosol. In this study, we provide evidence of TATA...... signal transductions by mitochondrial superoxide. Oxidative phosphorylation via the electron transfer chain, glycolysis, and generation of superoxide from mitochondria could be important factors in regulating signal transduction, cellular homeostasis, and cell death....

  1. Transport properties and metal-insulator transition in oxygen deficient LaNiO3: a density functional theory study

    Science.gov (United States)

    Misra, D.; Kundu, T. K.

    2016-09-01

    Density functional theory with appropriate functional has been employed to investigate the metal to insulator transition in oxygen deficient LaNiO3-x (x = 0.0, 0.25, 0.5, 1.0) compounds. While the metallic nature of LaNiO3 is characterized by the low temperature Fermi liquid behavior of resistivity and a finite density of states at the Fermi level, the density of states and the transport properties clearly identify LaNiO2.75 as a semiconductor, and LaNiO2.5 as an insulator, which is followed by another insulator to semiconductor transition with further increase of x to ‘1’ in LaNiO2. This oxygen vacancy controlled metal to insulator transition is explained on the basis of non-adiabatic polaronic transport. From the covalency metric calculation of the chemical bonding and the Bader charge transfer analysis, this metal to insulator transition is attributed to the enhanced covalent part in the chemical bonding and reduced charge transfer from Ni to O atoms in LaNiO3-x compounds.

  2. Dual-functional Memory and Threshold Resistive Switching Based on the Push-Pull Mechanism of Oxygen Ions

    KAUST Repository

    Huang, Yi-Jen

    2016-04-07

    The combination of nonvolatile memory switching and volatile threshold switching functions of transition metal oxides in crossbar memory arrays is of great potential for replacing charge-based flash memory in very-large-scale integration. Here, we show that the resistive switching material structure, (amorphous TiOx)/(Ag nanoparticles)/(polycrystalline TiOx), fabricated on the textured-FTO substrate with ITO as the top electrode exhibits both the memory switching and threshold switching functions. When the device is used for resistive switching, it is forming-free for resistive memory applications with low operation voltage (<±1 V) and self-compliance to current up to 50 μA. When it is used for threshold switching, the low threshold current is beneficial for improving the device selectivity. The variation of oxygen distribution measured by energy dispersive X-ray spectroscopy and scanning transmission electron microscopy indicates the formation or rupture of conducting filaments in the device at different resistance states. It is therefore suggested that the push and pull actions of oxygen ions in the amorphous TiOx and polycrystalline TiOx films during the voltage sweep account for the memory switching and threshold switching properties in the device.

  3. Dual-functional Memory and Threshold Resistive Switching Based on the Push-Pull Mechanism of Oxygen Ions

    Science.gov (United States)

    Huang, Yi-Jen; Chao, Shih-Chun; Lien, Der-Hsien; Wen, Cheng-Yen; He-Hau, Jr.; Lee, Si-Chen

    2016-04-01

    The combination of nonvolatile memory switching and volatile threshold switching functions of transition metal oxides in crossbar memory arrays is of great potential for replacing charge-based flash memory in very-large-scale integration. Here, we show that the resistive switching material structure, (amorphous TiOx)/(Ag nanoparticles)/(polycrystalline TiOx), fabricated on the textured-FTO substrate with ITO as the top electrode exhibits both the memory switching and threshold switching functions. When the device is used for resistive switching, it is forming-free for resistive memory applications with low operation voltage (compliance to current up to 50 μA. When it is used for threshold switching, the low threshold current is beneficial for improving the device selectivity. The variation of oxygen distribution measured by energy dispersive X-ray spectroscopy and scanning transmission electron microscopy indicates the formation or rupture of conducting filaments in the device at different resistance states. It is therefore suggested that the push and pull actions of oxygen ions in the amorphous TiOx and polycrystalline TiOx films during the voltage sweep account for the memory switching and threshold switching properties in the device.

  4. Quadratic function between arterial partial oxygen pressure and mortality risk in sepsis patients: an interaction with simplified acute physiology score.

    Science.gov (United States)

    Zhang, Zhongheng; Ji, Xuqing

    2016-10-13

    Oxygen therapy is widely used in emergency and critical care settings, while there is little evidence on its real therapeutic effect. The study aimed to explore the impact of arterial oxygen partial pressure (PaO2) on clinical outcomes in patients with sepsis. A large clinical database was employed for the study. Subjects meeting the diagnostic criteria of sepsis were eligible for the study. All measurements of PaO2 were extracted. The primary endpoint was death from any causes during hospital stay. Survey data analysis was performed by using individual ICU admission as the primary sampling unit. Quadratic function was assumed for PaO2 and its interaction with other covariates were explored. A total of 199,125 PaO2 samples were identified for 11,002 ICU admissions. Each ICU stay comprised 18 PaO2 samples in average. The fitted multivariable model supported our hypothesis that the effect of PaO2 on mortality risk was in quadratic form. There was significant interaction between PaO2 and SAPS-I (p = 0.007). Furthermore, the main effect of PaO2 on SOFA score was nonlinear. The study shows that the effect of PaO2 on mortality risk is in quadratic function form, and there is significant interaction between PaO2 and severity of illness.

  5. [Reactive oxygen species produced by the addition of sepiolite and vermiculite (expanded or not) to suspensions of human polymorphonuclear phagocytes and bovine alveolar macrophages].

    Science.gov (United States)

    Amati, M; Visonà, I; Valentino, M; Scancarello, G; Governa, M

    1997-01-01

    We have studied a sample of commercial sepiolite and two samples of commercial vermiculite, which are clay minerals advised to replace asbestos. We have in vitro tested their abilities to produce reacting oxygen species (ROS) after they have been added to suspension of human polymorphonuclear leukocytes and bovine alveolar macrophages. The behaviour of sepiolite and vermiculite have been compared with those of asbestos fibres given by Unione Internationale contre le Cancer (UICC) and with kaolin and illite. Sepiolite was not able to induce ROS production, while vermiculite was able to induce a relevant ROS generation, even if the values were always lower than that obtained from chrysotile. Kaolin was able to generate a high ROS production.

  6. Endothelial Microparticle-Derived Reactive Oxygen Species: Role in Endothelial Signaling and Vascular Function

    Directory of Open Access Journals (Sweden)

    Dylan Burger

    2016-01-01

    Full Text Available Endothelial microparticles are effectors of endothelial damage; however mechanisms involved are unclear. We examined the effects of eMPs on cultured endothelial cells (ECs and isolated vessels and investigated the role of eMP-derived reactive oxygen species (ROS and redox signaling in these processes. eMPs were isolated from EC media and their ability to directly produce ROS was assessed by lucigenin and liquid chromatography. Nicotinamide adenine dinucleotide phosphate oxidase (Nox subunits were probed by Western blot. ECs were treated with eMPs and effects on kinase signaling, superoxide anion (O2∙- generation, and nitric oxide (NO production were examined. Acetylcholine-mediated vasorelaxation was assessed by myography in eMP-treated mesenteric arteries. eMPs contained Nox1, Nox2, Nox4, p47phox, p67phox, and p22phox and they produced ROS which was inhibited by the Nox inhibitor, apocynin. eMPs increased phosphorylation of ERK1/2 and Src, increased O2∙- production, and decreased A23187-induced NO production in ECs. Pretreatment of eMPs with apocynin diminished eMP-mediated effects on ROS and NO production but had no effect on eMP-mediated kinase activation or impairment in vasorelaxation. Our findings identify a novel mechanism whereby eMP-derived ROS contributes to MP bioactivity. These interactions may be important in conditions associated with vascular injury and increased eMP formation.

  7. Synthesis of highly active and dual-functional electrocatalysts for methanol oxidation and oxygen reduction reactions

    Science.gov (United States)

    Zhao, Qi; Zhang, Geng; Xu, Guangran; Li, Yingjun; Liu, Baocang; Gong, Xia; Zheng, Dafang; Zhang, Jun; Wang, Qin

    2016-12-01

    The promising Pt-based ternary catalyst is crucial for polymer electrolyte membrane fuel cells (PEMFCs) due to improving catalytic activity and durability for both methanol oxidation reaction and oxygen reduction reaction. In this work, a facile strategy is used for the synthesis ternary RuMPt (M = Fe, Co, Ni, and Cu) nanodendrities catalysts. The ternary RuMPt alloys exhibit enhanced specific and mass activity, positive half-wave potential, and long-term stability, compared with binary Pt-based alloy and the commercial Pt/C catalyst, which is attributed to the high electron density and upshifting of the d-band center for Pt atoms, and synergistic catalytic effects among Pt, M, and Ru atoms by introducing a transition metal. Impressively, the ternary RuCoPt catalyst exhibits superior mass activity (801.59 mA mg-1) and positive half-wave potential (0.857 V vs. RHE) towards MOR and ORR, respectively. Thus, the RuMPt nanocomposite is a very promising material to be used as dual electrocatalyst in the application of PEMFCs.

  8. Screening of catalytic oxygen reduction reaction activity of metal-doped graphene by density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xin, E-mail: chenxin830107@pku.edu.cn; Chen, Shuangjing; Wang, Jinyu

    2016-08-30

    Highlights: • The screened M-G structures are very thermodynamically stable, and the stability is even higher than that of the corresponding bulk metal surfaces. • The binding energies of ORR intermediates suggest that they are not linear dependence, which are different form the cases found on some metal-based catalysts. • The Au-, Co-, and Ag-G structures could be used as the ORR catalysts. - Abstract: Graphene doping is a promising direction for developing effective oxygen reduction reaction (ORR) catalysts. In this paper, we computationally investigated the ORR performance of 10 kinds of metal-doped graphene (M-G) catalysts, namely, Al-, Si-, Mn-, Fe-, Co-, Ni-, Pd-, Ag-, Pt-, and Au-G. The results shown that the binding energies of the metal atoms incorporated into the graphene vacancy are higher than their bulk cohesive energies, indicating the formed M-G catalysts are even more stable than the corresponding bulk metal surfaces, and thus avoid the metals dissolution in the reaction environment. We demonstrated that the linear relation among the binding energies of the ORR intermediates that found on metal-based materials does not hold for the M-G catalysts, therefore a single binding energy of intermediate alone is not sufficient to evaluate the ORR activity of an arbitrary catalyst. By analysis of the detailed ORR processes, we predicted that the Au-, Co-, and Ag-G materials can be used as the ORR catalysts.

  9. Reactive-oxygen-species-mediated P. aeruginosa killing is functional in human cystic fibrosis macrophages.

    Directory of Open Access Journals (Sweden)

    Noemi Cifani

    Full Text Available Pseudomonas aeruginosa is the most common pathogen for chronic lung infection in cystic fibrosis (CF patients. About 80% of adult CF patients have chronic P. aeruginosa infection, which accounts for much of the morbidity and most of the mortality. Both bacterial genetic adaptations and defective innate immune responses contribute to the bacteria persistence. It is well accepted that CF transmembrane conductance regulator (CFTR dysfunction impairs the airways-epithelium-mediated lung defence; however, other innate immune cells also appear to be affected, such as neutrophils and macrophages, which thus contribute to this infectious pathology in the CF lung. In macrophages, the absence of CFTR has been linked to defective P. aeruginosa killing, increased pro-inflammatory cytokine secretion, and reduced reactive oxygen species (ROS production. To learn more about macrophage dysfunction in CF patients, we investigated the generation of the oxidative burst and its impact on bacterial killing in CF macrophages isolated from peripheral blood or lung parenchyma of CF patients, after P. aeruginosa infection. Our data demonstrate that CF macrophages show an oxidative response of similar intensity to that of non-CF macrophages. Intracellular ROS are recognized as one of the earliest microbicidal mechanisms against engulfed pathogens that are activated by macrophages. Accordingly, NADPH inhibition resulted in a significant increase in the intracellular bacteria survival in CF and non-CF macrophages, both as monocyte-derived macrophages and as lung macrophages. These data strongly suggest that the contribution of ROS to P. aeruginosa killing is not affected by CFTR mutations.

  10. CALCULATION OF THE FINE STRUCTURE OF OXYGEN-LIKE IONS USING THE POLARIZATION POTENTIAL FUNCTION

    Institute of Scientific and Technical Information of China (English)

    SHENG YONG; WANG RONG; JIANG GANG; ZHU ZHENG-HE

    2001-01-01

    We have calculated the forbidden transition energies and magnetic dipole transition probabilities of 2s22p4(3pl-3P2) and 2s22p4 (3p0-3p1) of oxygen-like isoelectronic sequences (Z=10-32) by a method of polarization potential correction. The transition energies show good agreement with experiment and are much better than the calculations in the literature. These results also illustrate that it is feasible to use the dipole expansion of the polarization potential to deal with some dynamic and non-dynamic effects in the central field approach. The relation of polarizability and cut-off radius with atomic number is discussed. We also give the fitted formula between the polarizability α1 and atomic number Z as c1 =0.73429-9.56644× 10-4Z+7.43016× 10-5Z2 -2.53298×10-6Z3+2.08306× 10-8Z4.

  11. Oxygen saturation/minute heart rate index: Simple lung function test for children.

    Science.gov (United States)

    Ozdemir, Ali; Dogruel, Dilek; Yilmaz, Ozlem

    2017-02-01

    The severity of airway obstruction can be accurately determined on spirometry in children with asthma. Other assessments may include peak expiratory flow and pulse oximetry. In the present study, we evaluated the validity and reliability of oxygen saturation/minute heart rate (SpO2 /MHR) index in the prediction of degree of severe airway obstruction in children with asthma. This was a retrospective study of children aged 7-17 followed for asthma at Mersin Women and Children's Hospital. The study compared SpO2 /MHR ratio with forced expiratory volume in 1 s (FEV1 ) measured on spirometry, an important indicator of small airway obstruction. A total of 296 patients were included in the study, and classified either as having normal FEV1 (FEV1 > 80% of predicted, n = 178) or severely reduced FEV1 (FEV1 MHR index in predicting low FEV1 were calculated on receiver operating characteristics analysis. An SpO2 /MHR ratio cut-off MHR ratio appears to be a highly useful index to assess airway obstruction in older children with asthma. Thus, it can be used as a marker of airway obstruction severity when spirometry is not available. © 2016 Japan Pediatric Society.

  12. Effect of Additives on Green Sand Molding Properties using Design of Experiments and Taguchi's Quality Loss Function - An Experimental Study

    Science.gov (United States)

    Desai, Bhagyashree; Mokashi, Pavani; Anand, R. L.; Burli, S. B.; Khandal, S. V.

    2016-09-01

    The experimental study aims to underseek the effect of various additives on the green sand molding properties as a particular combination of additives could yield desired sand properties. The input parameters (factors) selected were water and powder (Fly ash, Coconut shell and Tamarind) in three levels. Experiments were planned using design of experiments (DOE). On the basis of plans, experiments were conducted to understand the behavior of sand mould properties such as compression strength, shear strength, permeability number with various additives. From the experimental results it could be concluded that the factors have significant effect on the sand properties as P-value found to be less than 0.05 for all the cases studied. The optimization based on quality loss function was also performed. The study revealed that the quality loss associated with the tamarind powder was lesser compared to other additives selected for the study. The optimization based on quality loss function and the parametric analysis using ANOVA suggested that the tamarind powder of 8 gm per Kg of molding sand and moisture content of 7% yield better properties to obtain sound castings.

  13. Cobalt(III)-catalyzed synthesis of indazoles and furans by C-H bond functionalization/addition/cyclization cascades.

    Science.gov (United States)

    Hummel, Joshua R; Ellman, Jonathan A

    2015-01-14

    The development of operationally straightforward and cost-effective routes for the assembly of heterocycles from simple inputs is important for many scientific endeavors, including pharmaceutical, agrochemical, and materials research. In this article we describe the development of a new air-stable cationic Co(III) catalyst for convergent, one-step benchtop syntheses of N-aryl-2H-indazoles and furans by C-H bond additions to aldehydes followed by in situ cyclization and aromatization. Only a substoichiometric amount of AcOH is required as an additive that is both low-cost and convenient to handle. The syntheses of these heterocycles are the first examples of Co(III)-catalyzed additions to aldehydes, and reactions are demonstrated for a variety of aromatic, heteroaromatic, and aliphatic derivatives. The syntheses of both N-aryl-2H-indazoles and furans have been performed on 20 mmol scales and should be readily applicable to larger scales. The reported heterocycle syntheses also demonstrate the use of directing groups that have not previously been applied to Co(III)-catalyzed C-H bond functionalizations. Additionally, the synthesis of furans demonstrates the first example of Co(III)-catalyzed functionalization of alkenyl C-H bonds.

  14. Benchmark calculations of excess electrons in water cluster cavities: balancing the addition of atom-centered diffuse functions versus floating diffuse functions.

    Science.gov (United States)

    Zhang, Changzhe; Bu, Yuxiang

    2016-09-14

    Diffuse functions have been proved to be especially crucial for the accurate characterization of excess electrons which are usually bound weakly in intermolecular zones far away from the nuclei. To examine the effects of diffuse functions on the nature of the cavity-shaped excess electrons in water cluster surroundings, both the HOMO and LUMO distributions, vertical detachment energies (VDEs) and visible absorption spectra of two selected (H2O)24(-) isomers are investigated in the present work. Two main types of diffuse functions are considered in calculations including the Pople-style atom-centered diffuse functions and the ghost-atom-based floating diffuse functions. It is found that augmentation of atom-centered diffuse functions contributes to a better description of the HOMO (corresponding to the VDE convergence), in agreement with previous studies, but also leads to unreasonable diffuse characters of the LUMO with significant red-shifts in the visible spectra, which is against the conventional point of view that the more the diffuse functions, the better the results. The issue of designing extra floating functions for excess electrons has also been systematically discussed, which indicates that the floating diffuse functions are necessary not only for reducing the computational cost but also for improving both the HOMO and LUMO accuracy. Thus, the basis sets with a combination of partial atom-centered diffuse functions and floating diffuse functions are recommended for a reliable description of the weakly bound electrons. This work presents an efficient way for characterizing the electronic properties of weakly bound electrons accurately by balancing the addition of atom-centered diffuse functions and floating diffuse functions and also by balancing the computational cost and accuracy of the calculated results, and thus is very useful in the relevant calculations of various solvated electron systems and weakly bound anionic systems.

  15. The DNase of gammaherpesviruses impairs recognition by virus-specific CD8+ T cells through an additional host shutoff function.

    Science.gov (United States)

    Zuo, Jianmin; Thomas, Wendy; van Leeuwen, Daphne; Middeldorp, Jaap M; Wiertz, Emmanuel J H J; Ressing, Maaike E; Rowe, Martin

    2008-03-01

    The DNase/alkaline exonuclease (AE) genes are well conserved in all herpesvirus families, but recent studies have shown that the AE proteins of gammaherpesviruses such as Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) exhibit an additional function which shuts down host protein synthesis. One correlate of this additional shutoff function is that levels of cell surface HLA molecules are downregulated, raising the possibility that shutoff/AE genes of gammaherpesviruses might contribute to viral immune evasion. In this study, we show that both BGLF5 (EBV) and SOX (KSHV) shutoff/AE proteins do indeed impair the ability of virus-specific CD8+ T-cell clones to recognize endogenous antigen via HLA class I. Random mutagenesis of the BGLF5 gene enabled us to genetically separate the shutoff and AE functions and to demonstrate that the shutoff function was the critical factor determining whether BGLF5 mutants can impair T-cell recognition. These data provide further evidence that EBV has multiple mechanisms to modulate HLA class I-restricted T-cell responses, thus enabling the virus to replicate and persist in the immune-competent host.

  16. BRAIN FUNCTIONAL IMAGING BASED ON BRAIN TISSUE OXYGEN CONTENT VIA MAGNETIC RESONANCE

    Directory of Open Access Journals (Sweden)

    M.A OGHABIAN

    2003-03-01

    Full Text Available Introduction: FMRI is a new approach in MRI to provide functional data of human brain activities. Some methods such as BOLD contrast, perfusion imaging, diffusion imaging, and spectroscopy in MRI have used to yield functional images. Material and Methods: This research was performed in imaging center of IMAM KHOMEINI hospital in TEHRAN in 1997. The experiments were performed on a conventional 1.5- T picker MR instrument, using a standard head coil. CE – FAST gradient echo images were obtained (TR=100, TE = 35, 128*256 matrix, 10 mm slice, FOV = 250 mm, F.A =25 Degree, NEX = 1, 13 s per image. Images were obtained during sensory - motor stimulation by pressing fingers to each other, coronal oblique images were acquired through central sulcus (precentral gyrus where the related sensory cortex is. Then, the Images were transferred to personal computers in order to eliminate noise and highlight the functional differences. These images were processed by various mathematical methods such as subtraction and student T- test. Results: Although some changes were seen in functional area, there were not significant results by the conventional system protocols. Some new protocols were designed and implemented to increase the sensitivity of the system to functional changes. Discussion: However, more research needs to be done in the future to obtain faster and more efficient techniques and in regard to clinical applications of the method.

  17. Time-dependent density functional study of the electronic potential energy curves and excitation spectrum of the oxygen molecule.

    Science.gov (United States)

    Guan, Jingang; Wang, Fan; Ziegler, Tom; Cox, Hazel

    2006-07-28

    Orbital energies, ionization potentials, molecular constants, potential energy curves, and the excitation spectrum of O(2) are calculated using time-dependent density functional theory (TDDFT) with Tamm-Dancoff approximation (TDA). The calculated negative highest occupied molecular orbital energy (-epsilon(HOMO)) is compared with the energy difference ionization potential for five exchange correlation functionals consisting of the local density approximation (LDAxc), gradient corrected Becke exchange plus Perdew correlation (B(88X)+P(86C)), gradient regulated asymptotic correction (GRAC), statistical average of orbital potentials (SAOP), and van Leeuwen and Baerends asymptotically correct potential (LB94). The potential energy curves calculated using TDDFT with the TDA at internuclear distances from 1.0 to 1.8 A are divided into three groups according to the electron configurations. The 1pi(u) (4)1pi(g) (2) electron configuration gives rise to the X (3)Sigma(g) (-), a (1)Delta(g), and b (1)Sigma(g) (+) states; the 1pi(u) (3)1pi(g) (3) electron configuration gives rise to the c (1)Sigma(u) (-), C (3)Delta(u), and A (3)Sigma(u) (+) states; and the B (3)Sigma(u) (-), A (1)Delta(u), and f (1)Sigma(u) (+) states are determined by the mixing of two or more electron configurations. The excitation spectrum of the oxygen molecule, calculated with the aforementioned exchange correlation functionals, shows that the results are quite sensitive to the choice of functional. The LDAxc and the B(88X)+P(86C) functionals produce similar spectroscopic patterns with a single strongly absorbing band positioned at 19.82 and 19.72 eV, respectively, while the asymptotically corrected exchange correlation functionals of the SAOP and the LB94 varieties yield similar excitation spectra where the computed strongly absorbing band is located at 16.09 and 16.42 eV, respectively. However, all of the exchange correlation functionals yield only one strongly absorbing band (oscillator strength

  18. Reduced oxygen due to high-altitude exposure relates to atrophy in motor-function brain areas.

    Science.gov (United States)

    Di Paola, M; Paola, M D; Bozzali, M; Fadda, L; Musicco, M; Sabatini, U; Caltagirone, C

    2008-10-01

    At high altitudes barometric pressure is reduced and, thus, less oxygen is inhaled. Reduced oxygen concentration in brain tissue can lead to cerebral damage and neurological and cognitive deficits. The present study was designed to explore the effects of high-altitude exposure using a quantitative MRI technique, voxel-based morphometry. We studied nine world-class mountain climbers before (baseline) and after (follow-up) an extremely high-altitude ascent of Everest and K2. We investigated the effects of repeated extremely high-altitude exposures by comparing mountain climbers' scans at baseline with scans of 19 controls. In addition, we measured the effects of a single extremely high-altitude expedition by comparing mountain climbers' scans at baseline and follow-up. A region of reduced white matter density/volume was found in the left pyramidal tract near the primary (BA 4) and supplementary (BA 6) motor cortex when mountain climbers at baseline were compared with controls. Further, when mountain climbers' scans before and after the expedition were compared, a region of reduced grey matter density/volume was found in the left angular gyrus (BA 39). These findings suggest that extremely high-altitude exposures may cause subtle white and grey matter changes that mainly affect brain regions involved in motor activity.

  19. Monensin sodium and functional oil as additive in protein-energy supplement for pasture-fed heifers

    Directory of Open Access Journals (Sweden)

    D. S. Mano

    2017-07-01

    Full Text Available The use of functional oil as an additive is a potential alternative to replace inorganic antimicrobial agents. The objective of this study was to evaluate the effect of adding functional oil consisting of cashew and castor oil or monensin sodium to protein-energy supplement on the performance of 14-month-old Nellore x Red Angus heifers (initial mean body weight [BW] of 246 kg raised on Tifton 85 pasture. The animals were randomly assigned to four treatments: 1 control (no supplementation; 2 addition of 2 g functional oil/animal/day, composed of 70% cashew oil and 30% castor oil; 3 addition of 4 g functional oil/animal/day, composed of 70% cashew oil and 30% castor oil, and 4 addition of 0.2 g monensin sodium/animal/day. The biomass availability and forage on offer were 5,940 kg dry matter/ha and 7.0 kg dry matter/100 kg BW/day, respectively. The average proportion of leaf blade, sheath plus stem and senescent material was 17.6%, 55.0% and 27.4%, respectively. The mean whole-plant contents of crude protein, neutral detergent fiber and in vitro dry matter digestibility were 8.5%, 72.3% and 42.7%, respectively. A significant effect was observed for average daily gain of heifers receiving monensin (0.576 g/day compared to those that did not receive the protein-energy supplement (0.290 g/day. In contrast, the supplement containing the functional oil composed of cashew and castor oil provided weight gains (0.426 g/day similar (P>0.05 to that of the supplement with monensin (0.576 g/days. Under the conditions of this experiment, only the supplement with monensin resulted in a higher average daily gain than that observed for unsupplemented animals (control, while animals fed the supplement with functional oil composed of cashew and castor oil (2 or 4 g/animal/day did not exhibit differences in daily gain when compared to the other supplements.

  20. IMPORTANCE OF ACTIVATED CARBON'S OXYGEN SURFACE FUNCTIONAL GROUPS ON ELEMENTAL MERCURY ADSORPTION

    Science.gov (United States)

    The effect of varying physical and chemical properties of activated carbons on adsorption of elemental mercury [Hg(0)] was studied by treating two activated carbons to modify their surface functional groups and pore structures. Heat treatment (1200 K) in nitrogen (N2), air oxidat...

  1. PGC-1α and reactive oxygen species regulate human embryonic stem cell-derived cardiomyocyte function

    NARCIS (Netherlands)

    M.J. Birket (Matthew); S. Casini (Simona); G. Kosmidis (Georgios); D.J. Elliott (David); A.A. Gerencser (Akos); A. Baartscheer (Antonius); C. Schumacher (Cees); P.G. Mastroberardino (Pier); A.G. Elefanty (Andrew); E.G. Stanley (Ed); C.L. Mummery (Christine)

    2013-01-01

    textabstractDiminished mitochondrial function is causally related to some heart diseases. Here, we developed a human disease model based on cardiomyocytes from human embryonic stem cells (hESCs), in which an important pathway of mitochondrial gene expression was inactivated. Repression of PGC-1α, wh

  2. The Influence of Endothelial Function and Myocardial Ischemia on Peak Oxygen Consumption in Patients with Coronary Artery Disease

    Directory of Open Access Journals (Sweden)

    Simon L. Bacon

    2012-01-01

    Full Text Available Impaired endothelial function has been shown to limit exercise in coronary artery disease (CAD patients and has been implicated in myocardial ischemia. However, the association of endothelial function and ischemia on peak exercise oxygen consumption (VO2 has not been previously reported. A total of 116 CAD patients underwent standard exercise stress testing, during which VO2 was measured. On a separate day, endothelial-dependent and -independent function were assessed by ultrasound using flow-mediated arterial vasodilation (FMD and sublingual glyceryl trinitrate administration (GTNMD of the brachial artery. Patients with exercise-induced myocardial ischemia had lower FMD than nonischemic patients (3.64±0.57 versus 4.98±0.36, P=.050, but there was no difference in GTNMD (14.11±0.99 versus 15.47±0.63, P=.249. Analyses revealed that both FMD (P=.006 and GTNMD (P=.019 were related to peak VO2. However, neither the presence of ischemia (P=.860 nor the interaction of ischemia with FMD (P=.382 and GTNMD (P=.151 was related to peak VO2. These data suggest that poor endothelial function, potentially via impaired NO production and smooth muscle dysfunction, may be an important determinant of exercise capacity in patients with CAD, independent of myocardial ischemia.

  3. Effects of soot absorption coefficient-Planck function correlation on radiative heat transfer in oxygen-enriched propane turbulent diffusion flame

    Science.gov (United States)

    Consalvi, J. L.; Nmira, F.

    2016-03-01

    The main objective of this article is to quantify the influence of the soot absorption coefficient-Planck function correlation on radiative loss and flame structure in an oxygen-enhanced propane turbulent diffusion flame. Calculations were run with and without accounting for this correlation by using a standard k-ε model and the steady laminar flamelet model (SLF) coupled to a joint Probability Density Function (PDF) of mixture fraction, enthalpy defect, scalar dissipation rate, and soot quantities. The PDF transport equation is solved by using a Stochastic Eulerian Field (SEF) method. The modeling of soot production is carried out by using a flamelet-based semi-empirical acetylene/benzene soot model. Radiative heat transfer is modeled by using a wide band correlated-k model and turbulent radiation interactions (TRI) are accounted for by using the Optically-Thin Fluctuation Approximation (OTFA). Predicted soot volume fraction, radiant wall heat flux distribution and radiant fraction are in good agreement with the available experimental data. Model results show that soot absorption coefficient and Planck function are negatively correlated in the region of intense soot emission. Neglecting this correlation is found to increase significantly the radiative loss leading to a substantial impact on flame structure in terms of mean and rms values of temperature. In addition mean and rms values of soot volume fraction are found to be less sensitive to the correlation than temperature since soot formation occurs mainly in a region where its influence is low.

  4. Reproducibly creating hierarchical 3D carbon to study the effect of Si surface functionalization on the oxygen reduction reaction

    Science.gov (United States)

    Zeng, Yuze; Flores, Jose F.; Shao, Yu-Cheng; Guo, Jinghua; Chuang, Yi-De; Lu, Jennifer Q.

    2016-06-01

    We report a new method to reproducibly fabricate functional 3D carbon structures directly on a current collector, e.g. stainless steel. The 3D carbon platform is formed by direct growth of upright arrays of carbon nanofiber bundles on a roughened surface of stainless steel via the seed-assisted approach. Each bundle consists of about 30 individual carbon nanofibers with a diameter of 18 nm on average. We have found that this new platform offers adequate structural integrity. As a result, no reduction of the surface area during downstream chemical functionalization was observed. With a fixed and reproducible 3D structure, the effect of the chemistry of the grafted species on the oxygen reduction reaction has been systematically investigated. This investigation reveals for the first time that non-conductive Si with an appropriate electronic structure distorts the carbon electronic structure and consequently enhances ORR electrocatalysis. The strong interface provides excellent electron connectivity according to electrochemical analysis. This highly reproducible and stable 3D platform can serve as a stepping-stone for the investigation of the effect of carbon surface functionalization on electrochemical reactions in general.We report a new method to reproducibly fabricate functional 3D carbon structures directly on a current collector, e.g. stainless steel. The 3D carbon platform is formed by direct growth of upright arrays of carbon nanofiber bundles on a roughened surface of stainless steel via the seed-assisted approach. Each bundle consists of about 30 individual carbon nanofibers with a diameter of 18 nm on average. We have found that this new platform offers adequate structural integrity. As a result, no reduction of the surface area during downstream chemical functionalization was observed. With a fixed and reproducible 3D structure, the effect of the chemistry of the grafted species on the oxygen reduction reaction has been systematically investigated. This

  5. Functional importance of a pair of conserved glutamic acid residues and of Ca(2+) binding in the cbb(3)-type oxygen reductases from Rhodobacter sphaeroides and Vibrio cholerae.

    Science.gov (United States)

    Ouyang, Hanlin; Han, Huazhi; Roh, Jung H; Hemp, James; Hosler, Jonathan P; Gennis, Robert B

    2012-09-18

    The cbb(3)-type cytochrome c oxidases are members of the family of heme-copper proton pumping respiratory oxygen reductases. The structure of the cbb(3)-type oxidase from Pseudomonas stutzeri reveals that, in addition to the six redox-active metal centers (two b-type hemes, three c-type hemes, and Cu(B)), the enzyme also contains at least one Ca(2+). The calcium bridges two propionate carboxyls at the interface between the low-spin heme b and the active-site heme b(3) and, in addition, is ligated to a serine in subunit CcoO and by a glutamate in subunit CcoN. The glutamate that is ligated to Ca(2+) is one of a pair of glutamic acid residues that has previously been suggested to be part of a proton exit pathway for pumped protons. In this work, mutations of these glutamates are investigated in the cbb(3)-type oxidases from Vibrio cholerae and Rhodobacter sphaeroides. Metal analysis shows that each of these wild-type enzymes contains Ca(2+). Mutations of the glutamate expected to ligate the Ca(2+) in each of these enzymes (E126 in V. cholerae and E180 in R. sphaeroides) result in a loss of activity as well as a loss of Ca(2+). Mutations of the nearby glutamate (E129 in V. cholerae and E183 in R. sphaeroides) also resulted in a loss of oxidase activity and a loss of Ca(2+). It is concluded that the Ca(2+) is essential for assembly of the fully functional enzyme and that neither of the glutamates is likely to be part of a pathway for pumped protons within the cbb(3)-type oxygen reductases. A more likely role for these glutamates is the maintenance of the structural integrity of the active conformation of the enzyme.

  6. SiO2@MgO nanoparticles templated mesoporous carbon with rich electro-active oxygenic functionalities and enhanced supercapacitive performances

    Science.gov (United States)

    Tian, Zhengfang; Duan, Shuyi; Shen, Yu; Xie, Mingjiang; Guo, Xuefeng

    2017-06-01

    As a member of carbon-based materials, ordered mesoporous carbon (OMC) still suffers from poor capacity for supercapacitive applications. Functionalization the skeleton with pseudocapacitive functionalities is an efficient way to enhance the capacity of OMCs. Herein, a designed SiO2@MgO nanoparticle with uniform diameters was employed as template towards the synthesis of pseudocapacitive oxygen functionalized OMC. The obtained carbons possess ordered mesoporous structure, large surface area, and rich pseudocapacitive oxygen species. As electrode for supercapacitor in 1.0 M H2SO4, the SiO2@MgO templated OMC achieves higher capacitance (257 F/g) than pure SiO2 templated OMC (180 F/g), surfactant templated OMC (152 F/g) and commercial activated carbon (110 F/g) owing to the high pseudocapacitive oxygen functionalities, providing more capacity by reversible Faradaic reaction.

  7. Electrolytic reduction of Nantong coal and model compounds with oxygenic functional groups in an aqueous NaCl solution

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wei; YAO Li-ping; LIN Juan; ZONG Zhi-min

    2008-01-01

    Electrolytic reductions of oxygenic functional groups (OFGs) on coal surface and coal model compounds with OFGs in an aqueous NaCl solution are studied by electrochemical methods combined with GC/MS, GC and FTIR analyses. Different elec-trode reactions, their corresponding potentials and dynamic equations during the processes are investigated. The results show that benzoic acid, benzaldehyde, benzalcohol and hypnone are reduced to benzaldehyde and benzalcohol, methoxybenzene and benzal-cohol, toluene and styrene, respectively, at the cathode. The corresponding electrode potentials and dynamic equations are deter-mined. The electrolytic reduction also leads to an increase in the contents of hydroxyl groups and aliphatic moieties and a corre-sponding decrease in those of carboxyl and carbonyl groups in Nantong coal, a high-sulfur coal, an enhancement in the flotation desulfurization of the coal. ER also reduces organic sulfur and FeS2 in the coal.

  8. A surface work function measurement technique utilizing constant deflected grazing electron trajectories: oxygen uptake on Cu(001).

    Science.gov (United States)

    Ermakov, A V; Ciftlikli, E Z; Syssoev, S E; Shuttleworth, I G; Hinch, B J

    2010-10-01

    We report on the application of a novel nondestructive in-vacuum technique for relative work function measurements, employing a grazing incidence electron deflection above a sample with a planar surface. Two deflected electron beam detectors are used as a position sensitive detector to control feedback to the sample potential as the sample work function changes. With feedback the sample potential exactly follows the surface sample-size averaged work function variation, so that the deflected beam trajectory remains stable. We also discuss methods to optimize the initial electron trajectories for this method, so as to minimize unwanted effects such as from uncontrolled external magnetic fields. As the electron beam does not impinge on the surface in this new technique electron induced desorption, ionization, dissociation, and/or decomposition is not induced at the interface. Importantly also the technique allows for free access to the surfaces enabling simultaneous deposition/evaporation and/or application of other surface characterization methods. We demonstrate its application in concurrent measurements of helium atom reflectivity and work function changes taking place during molecular oxygen exposure of a Cu(001) surface. A work function measurement sensitivity and stability is demonstrated at ∼10 mV at a sampling rate of 1 Hz and after application of an ∼7 s smoothing routine. In comparison to the helium atom reflectivity measurements, the work function measurements are more sensitive to the initial O uptake, and less so to the final coverage variations and possible surface reordering at higher O coverages.

  9. Cerebral misery perfusion diagnosed using hypercapnic blood-oxygenation-level-dependent contrast functional magnetic resonance imaging: a case report

    Directory of Open Access Journals (Sweden)

    D'Souza Olympio

    2010-02-01

    Full Text Available Abstract Introduction Cerebral misery perfusion represents a failure of cerebral autoregulation. It is an important differential diagnosis in post-stroke patients presenting with collapses in the presence of haemodynamically significant cerebrovascular stenosis. This is particularly the case when cortical or internal watershed infarcts are present. When this condition occurs, further investigation should be done immediately. Case presentation A 50-year-old Caucasian man presented with a stroke secondary to complete occlusion of his left internal carotid artery. He went on to suffer recurrent seizures. Neuroimaging demonstrated numerous new watershed-territory cerebral infarcts. No source of arterial thromboembolism was demonstrable. Hypercapnic blood-oxygenation-level-dependent-contrast functional magnetic resonance imaging was used to measure his cerebrovascular reserve capacity. The findings were suggestive of cerebral misery perfusion. Conclusions Blood-oxygenation-level-dependent-contrast functional magnetic resonance imaging allows the inference of cerebral misery perfusion. This procedure is cheaper and more readily available than positron emission tomography imaging, which is the current gold standard diagnostic test. The most evaluated treatment for cerebral misery perfusion is extracranial-intracranial bypass. Although previous trials of this have been unfavourable, the results of new studies involving extracranial-intracranial bypass in high-risk patients identified during cerebral perfusion imaging are awaited. Cerebral misery perfusion is an important and under-recognized condition in which emerging imaging and treatment modalities present the possibility of practical and evidence-based management in the near future. Physicians should thus be aware of this disorder and of recent developments in diagnostic tests that allow its detection.

  10. Pentaerythritol Tetranitrate Targeting Myocardial Reactive Oxygen Species Production Improves Left Ventricular Remodeling and Function in Rats With Ischemic Heart Failure.

    Science.gov (United States)

    Fraccarollo, Daniela; Galuppo, Paolo; Neuser, Jonas; Bauersachs, Johann; Widder, Julian D

    2015-11-01

    Reduced nitric oxide bioavailability contributes to progression of cardiac dysfunction and remodeling in ischemic heart failure. Clinical use of organic nitrates as nitric oxide donors is limited by development of nitrate tolerance and reactive oxygen species formation. We investigated the effects of long-term therapy with pentaerythritol tetranitrate (PETN), an organic nitrate devoid of tolerance, in rats with congestive heart failure after extensive myocardial infarction. Seven days after coronary artery ligation, rats were randomly allocated to treatment with PETN (80 mg/kg BID) or placebo for 9 weeks. Long-term PETN therapy prevented the progressive left ventricular dilatation and improved left ventricular contractile function and relaxation in rats with congestive heart failure. Mitochondrial superoxide anion production was markedly increased in the failing left ventricular myocardium and nearly normalized by PETN treatment. Gene set enrichment analysis revealed that PETN beneficially modulated the dysregulation of mitochondrial genes involved in energy metabolism, paralleled by prevention of uncoupling protein-3, thioredoxin-2, and superoxide dismutase-2 downregulation. Moreover, PETN provided a remarkable protective effect against reactive fibrosis in chronically failing hearts. Mechanistically, induction of heme oxygenase-1 by PETN prevented mitochondrial superoxide generation, NOX4 upregulation, and ensuing formation of extracellular matrix proteins in fibroblasts from failing hearts. In summary, PETN targeting reactive oxygen species generation prevented the changes of mitochondrial antioxidant enzymes and progressive fibrotic remodeling, leading to amelioration of cardiac functional performance. Therefore, PETN might be a promising therapeutic option in the treatment of ischemic heart diseases involving oxidative stress and impairment in nitric oxide bioactivity.

  11. Living Additive Manufacturing: Transformation of Parent Gels into Diversely Functionalized Daughter Gels Made Possible by Visible Light Photoredox Catalysis.

    Science.gov (United States)

    Chen, Mao; Gu, Yuwei; Singh, Awaneesh; Zhong, Mingjiang; Jordan, Alex M; Biswas, Santidan; Korley, LaShanda T J; Balazs, Anna C; Johnson, Jeremiah A

    2017-02-22

    Light-initiated additive manufacturing techniques typically rely on layer-by-layer addition or continuous extraction of polymers formed via nonliving, free radical polymerization methods that render the final materials "dead" toward further monomer insertion; the polymer chains within the materials cannot be reactivated to induce chain extension. An alternative "living additive manufacturing" strategy would involve the use of photocontrolled living radical polymerization to spatiotemporally insert monomers into dormant "parent" materials to generate more complex and diversely functionalized "daughter" materials. Here, we demonstrate a proof-of-concept study of living additive manufacturing using end-linked polymer gels embedded with trithiocarbonate iniferters that can be activated by photoinduced single-electron transfer from an organic photoredox catalyst in solution. This system enables the synthesis of a wide range of chemically and mechanically differentiated daughter gels from a single type of parent gel via light-controlled modification of the parent's average composition, strand length, and/or cross-linking density. Daughter gels that are softer than their parent, stiffer than their parent, larger but with the same modulus as their parent, thermally responsive, polarity responsive, healable, and weldable are all realized.

  12. Clinical Evaluation of Functional Vision of +1.5 Diopters near Addition, Aspheric, Rotational Asymmetric Multifocal Intraocular Lens

    Science.gov (United States)

    Khoramnia, Rahmin; Attia, Mary Safwat; Koss, Michael Janusz; Linz, Katharina; Auffarth, Gerd Uwe

    2016-01-01

    Purpose To evaluate postoperative outcomes and visual performance in intermediate distance after implantation of a +1.5 diopters (D) addition, aspheric, rotational asymmetric multifocal intraocular lens (MIOL). Methods Patients underwent bilateral cataract surgery with implantation of an aspheric, asymmetric MIOL with +1.5 D near addition. A complete ophthalmological examination was performed preoperatively and 3 months postoperatively. The main outcome measures were monocular and binocular uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected intermediate visual acuity (UIVA), distance corrected intermediate visual acuity (DCIVA), uncorrected near visual acuity (UNVA) and distance corrected keratometry, and manifest refraction. The Salzburg Reading Desk was used to analyze unilateral and bilateral functional vision with uncorrected and corrected reading acuity, reading distance, reading speed, and the smallest log-scaled print size that could be read effectively at near and intermediate distances. Results The study comprised 60 eyes of 30 patients (mean age, 68.30 ± 9.26 years; range, 34 to 80 years). There was significant improvement in UDVA and CDVA. Mean UIVA was 0.01 ± 0.09 logarithm of the minimum angle of resolution (logMAR) and mean DCIVA was -0.02 ± 0.11 logMAR. In Salzburg Reading Desk analysis for UIVA, the mean subjective intermediate distance was 67.58 ± 8.59 cm with mean UIVA of -0.02 ± 0.09 logMAR and mean word count of 96.38 ± 28.32 words/min. Conclusions The new aspheric, asymmetric, +1.5 D near addition MIOL offers good results for distance visual function in combination with good performance for intermediate distances and functional results for near distance. PMID:27729759

  13. An additional function for bacteriophage lambda rex: the rexB product prevents degradation of the lambda O protein.

    OpenAIRE

    Schoulaker-Schwarz, R; Dekel-Gorodetsky, L; Engelberg-Kulka, H

    1991-01-01

    The rex operon of bacteriophage lambda excludes the development of several unrelated bacteriophages. Here we present an additional lambda rexB function: it prevents degradation of the short-lived protein lambda O known to be involved in lambda DNA replication. We have shown that it is the product of rexB that is responsible for the stabilization of lambda O: when a nonsense mutation is present in rexB, lambda O protein is labile; suppression of the mutation by the corresponding nonsense suppr...

  14. A short period of high-intensity interval training improves skeletal muscle mitochondrial function and pulmonary oxygen uptake kinetics.

    Science.gov (United States)

    Christensen, Peter M; Jacobs, Robert A; Bonne, Thomas; Flück, Daniela; Bangsbo, Jens; Lundby, Carsten

    2016-06-01

    The aim of the present study was to examine whether improvements in pulmonary oxygen uptake (V̇o2) kinetics following a short period of high-intensity training (HIT) would be associated with improved skeletal muscle mitochondrial function. Ten untrained male volunteers (age 26 ± 2 yr; mean ± SD) performed six HIT sessions (8-12 × 60 s at incremental test peak power; 271 ± 52 W) over a 2-wk period. Before and after the HIT period, V̇o2 kinetics was modeled during moderate-intensity cycling (110 ± 19 W). Mitochondrial function was assessed with high-resolution respirometry (HRR), and maximal activities of oxidative enzymes citrate synthase (CS) and cytochrome c oxidase (COX) were accordingly determined. In response to HIT, V̇o2 kinetics became faster (τ: 20.4 ± 4.4 vs. 28.9 ± 6.1 s; P CIIP) (P < 0.05). Collectively, these findings support that selected measures of mitochondrial function obtained with HRR are important for fast V̇o2 kinetics and better markers than maximal oxidative enzyme activity in describing the speed of the V̇o2 response during moderate-intensity exercise.

  15. Covalent functionalization based heteroatom doped graphene nanosheet as a metal-free electrocatalyst for oxygen reduction reaction

    Science.gov (United States)

    Park, Minju; Lee, Taemin; Kim, Byeong-Su

    2013-11-01

    Oxygen reduction reaction (ORR) is an important reaction in energy conversion systems such as fuel cells and metal-air batteries. Carbon nanomaterials doped with heteroatoms are highly attractive materials for use as electrocatalysts by virtue of their excellent electrocatalytic activity, high conductivity, and large surface area. This study reports the synthesis of highly efficient electrocatalysts based on heteroatom-doped graphene nanosheets prepared through covalent functionalization using various small organic molecules and a subsequent thermal treatment. A series of nitrogen-doped reduced graphene oxide (NRGOn) nanosheets exhibited varying degrees and configurations of nitrogen atoms within the graphitic framework depending on the type of precursors used. On the basis of the rotating disk electrode (RDE) and rotating ring-disk electrode (RRDE) experiments, NRGO3, with a high degree of pyridinic-N content, displayed the desired one-step, quasi-four-electron transfer pathway during ORR, similar to commercial Pt/C. We also demonstrated the potential of covalent functionalization of sulfur and boron-doped graphene nanosheets.Oxygen reduction reaction (ORR) is an important reaction in energy conversion systems such as fuel cells and metal-air batteries. Carbon nanomaterials doped with heteroatoms are highly attractive materials for use as electrocatalysts by virtue of their excellent electrocatalytic activity, high conductivity, and large surface area. This study reports the synthesis of highly efficient electrocatalysts based on heteroatom-doped graphene nanosheets prepared through covalent functionalization using various small organic molecules and a subsequent thermal treatment. A series of nitrogen-doped reduced graphene oxide (NRGOn) nanosheets exhibited varying degrees and configurations of nitrogen atoms within the graphitic framework depending on the type of precursors used. On the basis of the rotating disk electrode (RDE) and rotating ring-disk electrode

  16. Diffusion of interstitial oxygen in silicon and germanium: a hybrid functional study

    Science.gov (United States)

    Colleoni, Davide; Pasquarello, Alfredo

    2016-12-01

    The minimum-energy paths for the diffusion of an interstitial O atom in silicon and germanium are studied through the nudged-elastic-band method and hybrid functional calculations. The reconsideration of the diffusion of O in silicon primarily serves the purpose of validating the procedure for studying the O diffusion in germanium. Our calculations show that the minimum energy path goes through an asymmetric transition state in both silicon and germanium. The stability of these transition states is found to be enhanced by the generation of unpaired electrons in the highest occupied single-particle states. Calculated energy barriers are 2.54 and 2.14 eV for Si and Ge, in very good agreement with corresponding experimental values of 2.53 and 2.08 eV, respectively.

  17. Structural and surface functionality changes in reticulated vitreous carbon produced from poly(furfuryl alcohol) with sodium hydroxide additions

    Science.gov (United States)

    Oishi, Silvia Sizuka; Botelho, Edson Cocchieri; Rezende, Mirabel Cerqueira; Ferreira, Neidenêi Gomes

    2017-02-01

    The use of sodium hydroxide to neutralize the acid catalyst increases the storage life of poly(furfuryl alcohol) (PFA) resin avoiding its continuous polymerization. In this work, a concentrated sodium hydroxide solution (NaOH) was added directly to the PFA resin in order to minimize the production of wastes generated when PFA is washed with diluted basic solution. Thus, different amounts of this concentrated basic solution were added to the resin up to reaching pH values of around 3, 5, 7, and 9. From these four types of modified PFA two sample sets of reticulated vitreous carbon (RVC) were processed and heat treated at two different temperatures (1000 and 1700 °C). A correlation among cross-link density of PFA and RVC morphology, structural ordering and surface functionalities was systematically studied using Fourier transform infrared spectroscopy, scanning electron microscopy, Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy techniques. The PFA neutralization (pH 7) led to its higher polymerization degree, promoting a crystallinity decrease on RVC treated at 1000 °C as well as its highest percentages of carboxylic groups on surface. A NaOH excess (pH 9) substantially increased the RVC oxygen content, but its crystallinity remained similar to those for samples from pH 3 and 5 treated at 1000 °C, probably due to the reduced presence of carboxylic group and the lower polymerization degree of its cured resin. Samples with pH 3 and 5 heat treated at 1000 and 1700 °C can be considered the most ordered which indicated that small quantities of NaOH may be advantageous to minimize continuous polymerization of PFA resin increasing its storage life and improving RVC microstructure.

  18. Response of Functional Structure of Soil Microbial Community to Multi-level Nitrogen Additions on the Central Tibetan Plateau

    Science.gov (United States)

    Zhang, G.; Yuan, Y.

    2015-12-01

    The use of fossil fuels and fertilizers has increased the amount of biologically reactive nitrogen in the atmosphere over the past century. Tibet is the one of the most threatened regions by nitrogen deposition, thus understanding how its microbial communities function maybe of high importance to predicting microbial responses to nitrogen deposition. Here we describe a short-time nitrogen addition conducted in an alpine steppe ecosystem to investigate the response of functional structure of soil microbial community to multi-level nitrogen addition. Using a GeoChip 4.0, we showed that functional diversities and richness of functional genes were unchanged at low level of nitrogen fertilizer inputs (nitrogen fertilizer inputs (>=40 kg N ha-1 yr-1). Detrended correspondence analysis indicated that the functional structure of microbial communities was markedly different across the nitrogen gradients. Most C degradation genes whose abundances significantly increased under elevated N fertilizer were those involved in the degradation of relatively labile C (starch, hemicellulose, cellulose), whereas the abundance of certain genes involved in the degradation of recalcitrant C (i.e. lignin) was largely decreased (such as manganese peroxidase, mnp). The results suggest that the elevated N fertilization rates might significantly accelerate the labile C degradation, but might not spur recalcitrant C degradation. The combined effect of gdh and ureC genes involved in N cycling appeared to shift the balance between ammonia and organic N toward organic N ammonification and hence increased the N mineralization potential. Moreover, Urease directly involved in urea mineralization significantly increased. Lastly, Canonical correspondence analysis showed that soil (TOC+NH4++NO3-+NO2-+pH) and plant (Aboveground plant productivity + Shannon Diversity) variables could explain 38.9% of the variation of soil microbial community composition. On the basis of above observations, we predict that

  19. Role of Lewis acid additives in a palladium catalyzed directed C-H functionalization reaction of benzohydroxamic acid to isoxazolone.

    Science.gov (United States)

    Athira, C; Sunoj, Raghavan B

    2016-12-20

    Metallic salts as well as protic additives are widely employed in transition metal catalyzed C-H bond functionalization reactions to improve the efficiency of catalytic protocols. In one such example, ZnCl2 and pivalic acid are used as additives in a palladium catalyzed synthesis of isoxazolone from a readily available benzohydroxamic acid under one pot conditions. In this article, we present some important mechanistic insights into the role of ZnCl2 and pivalic acid, gained by using density functional theory (M06) computations. Two interesting modes of action of ZnCl2 are identified in various catalytic steps involved in the formation of isoxazolone. The conventional Lewis acid coordination wherein zinc chloride (ZnCl2·(DMA)) binds to the carbonyl group is found to be more favored in the C-H activation step. However, the participation of a hetero-bimetallic Pd-Zn species is preferred in reductive elimination leading to Caryl-N bond formation. Pivalic acid helps in relay proton transfer in C-H bond activation through a cyclometallation deprotonation (CMD) process. The explicit inclusion of ZnCl2 and solvent N,N-dimethyl acetamide (DMA) stabilizes the transition state and also helps reduce the activation barrier for the C-H bond activation step. The electronic communication between the two metal species is playing a crucial role in stabilizing the Caryl-N bond formation transition state through a Pd-Zn hetero-bimetallic interaction.

  20. Effect of huitlacoche (Ustilago maydis DC Corda paste addition on functional, chemical and textural properties of tortilla chips

    Directory of Open Access Journals (Sweden)

    Karla Yuritzi Amador-Rodríguez

    2015-09-01

    Full Text Available AbstractThis study analyzed the addition of huitlacoche paste (HP in baked tortilla chips (TC, evaluating its effects on functional, physicochemical and structural changes during processing. Two blue corn grains were nixtamalized, stone milled, air dried and milled to obtain flour; commercial blue corn flour (TM1 and commercial TC (TM2 were used as controls. Additions of 0, 3, 6 and 9% of HP were formulated; masas were prepared at 55% moisture content (MC, precooked and baked in an industrial machine. TC crispiness was influenced by grain characteristics and percentage of HP. Huitlacoche paste addition caused an increase in total dietary fiber (from 5.27 to 14.54%, total soluble phenolics content (from 17.52 to 37.60 mg GAE/100 g and antioxidant capacity (from 6.74 to 7.98 μmol TE/g in TC. Results suggest that tortilla chips added with huitlacoche can be an alternative to prepare this traditional edible fungus and produce healthier snacks, not fried and enriched with bioactive compounds.

  1. Functional imaging of muscle oxygenation and oxygen consumption in the knee extensor muscles during isometric contractions by spatially resolved near-infrared spectroscopy

    Science.gov (United States)

    Kek, Khai Jun; Miyakawa, Takahiro; Kudo, Nobuki; Yamamoto, Katsuyuki

    2007-02-01

    In this study, we showed that exercise type- and intensity-dependent regional differences in muscle oxygenation and oxygen consumption rate (Vo II) of the knee extensor muscles could be imaged in real time with a multi-channel spatially resolved near-infrared spectroscopy (SR-NIRS) imaging device. Healthy subjects performed isometric knee extension exercise for 30 s (without- or with-leg-press action) at different exercise intensities [10%, 40% and 70% of maximum voluntary contraction (MVC)]. "Separation-type" probes were attached to the skin over the major knee extensor muscles: vastus lateralis (VL), rectus femoris (RF) and vastus medialis (VM). Placement of the probes enabled simultaneously measurement of 12 sites over a skin area of about 30 cm2 (temporal resolution = 0.25 s). Local Vo II of each muscle, resting Vo II (Vo II, rest) and recovery Vo II (Vo II, rec ), were determined with arterial occlusion before the start and after the end of contraction, respectively. There was no significant difference between the values of Vo II rest, in the muscles. However, during knee extension exercise without-leg-press action, Vo II rec, value of the RF was significantly greater than the values of the VL and VM at all exercise intensities. In contrast, during exercise with-leg-press action, Vo II rec, values of the RF and VM were greater than those of the VL, especially during exercise at 40% and 70% MVC. In summary, the regional differences in muscle oxygenation and Vo II of the knee extensor muscles, probably due to the differences in relative contributions of muscles to exercise and in muscle architecture, were imaged using SR-NIRS.

  2. Skeletal muscle oxygen uptake in obese patients: functional evaluation by knee-extension exercise.

    Science.gov (United States)

    Lazzer, Stefano; Salvadego, Desy; Porcelli, Simone; Rejc, Enrico; Agosti, Fiorenza; Sartorio, Alessandro; Grassi, Bruno

    2013-08-01

    We hypothesized, in a group of obese women (OB), a more significant impairment of aerobic metabolism during knee extension (KE) exercise vs. that described during cycle ergometer exercise, lending support to the role of skeletal muscles in limiting exercise tolerance in OB. Eleven OB (age 29.5 ± 5.5 years, body mass index 43.2 ± 5.4 kg m(-2)) and 10 non-obese controls (CTRL) women were tested. Fat-free mass of a lower-limb (FFMLL) was assessed by a densitometer. Heart rate (HR) and pulmonary O2 uptake (VO2) were determined during incremental exercise tests to voluntary exhaustion carried out on a custom-built KE ergometer and on a cycle ergometer (CE). FFMLL and maximal isometric force of KE muscles were higher in OB vs. CTRL (+42.4 and +46.2 %, respectively). Peak work rate was significantly lower in OB (-18.4 %) vs. CTRL in CE, but not in KE. Expressed in mL min(-1), peak VO2 was not different in OB vs. CTRL in CE and in KE. After it was divided per unit of FFM involved in the exercises, peak VO2 was significantly lower in OB vs. CTRL, both for CE (-19 %) and KE (-33 %). Expressed per unit of exercising muscle mass, peak oxidative function is impaired in OB. The impairment is more pronounced after limitations related to cardiovascular O2 delivery are reduced. In OB muscle hypertrophy and the increased muscle force allow to preserve exercise tolerance during aerobic exercises carried out by relatively small muscle masses.

  3. Omega-3 fatty acids supplementation improves endothelial function and maximal oxygen uptake in endurance-trained athletes.

    Science.gov (United States)

    Żebrowska, Aleksandra; Mizia-Stec, Katarzyna; Mizia, Magda; Gąsior, Zbigniew; Poprzęcki, Stanisław

    2015-01-01

    The study aimed to evaluate the effects of a 3-week n-3 polyunsaturated fatty acids (n-3 PUFA) supplementation on serum nitric oxide (NO), asymmetric dimethyloarginine (ADMA), ultrasound indices of endothelial function and maximal oxygen uptake (VO2 max) of elite cyclists. The effects of dietary supplementation (n-3 PUFA at a dose of 1.3 g twice daily for 3 weeks) and placebo administration on flow-mediated dilatation (FMD), pulse wave velocity, serum markers (NO, ADMA), lipid profile, and ΔVO2max were analysed in 13 cyclists both before and after dietary protocols. Significant differences between pre- and post-intervention baseline NO levels were observed after n-3 PUFA dietary protocol (13.9 ± 4.2 vs. 23.5 ± 3.6 µmol·l(-1); P PUFA diet compared with placebo (23.5 ± 3.6 vs. 15.3 ± 3.0 µmol·l(-1); P PUFA increased baseline NO concentration (ΔNO) by 6.7 ± 3.8 µmol·l(-1) and placebo by 1.6 ± 4.4 µmol·l(-1). The positive correlation was observed between baseline post-intervention NO concentration and maximal oxygen uptake (r = 0.72; P omega-3 fatty acids supplementation. There was an association between a 5.25% higher FMD (P PUFA diet compared with lower values of placebo (r = 0.68; P PUFA supplementation may play a central role in cardiovascular adaptive mechanisms and enhanced exercise performance in cyclists.

  4. Structure-Function of the Cytochrome b6f Complex of Oxygenic Photosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Cramer, W. A.; Yamashita, E.; Baniulis, D.; Whitelegge, J.; Hasan, S. S. [Lithuanian RAF; (UCLA); (Purdue); (Osaka)

    2014-03-20

    Structure–function of the major integral membrane cytochrome b6f complex that functions in cyanobacteria, algae, and green plants to transfer electrons between the two reaction center complexes in the electron transport chain of oxygenic photosynthesis is discussed in the context of recently obtained crystal structures of the complex and soluble domains of cytochrome f and the Rieske iron–sulfur protein. The energy-transducing function of the complex, generation of the proton trans-membrane electrochemical potential gradient, centers on the oxidation/reduction pathways of the plastoquinol/plastoquinone (QH2/Q), the proton donor/acceptor within the complex. These redox reactions are carried out by five redox prosthetic groups embedded in each monomer, the high potential two iron–two sulfur cluster and the heme of cytochrome f on the electropositive side (p) of the complex, two noncovalently bound b-type hemes that cross the complex and the membrane, and a covalently bound c-type heme (cn) on the electronegative side (n). These five redox-active groups are organized in high- (cyt f/[2Fe–2S] and low-potential (hemes bp, bn, cn) electron transport pathways that oxidize and reduce the quinol and quinone on the p- and n-sides in a Q-cycle-type mechanism, while translocating as many as 2 H+ to the p-side aqueous side for every electron transferred through the high potential chain to the photosystem I reaction center. The presence of heme cn and the connection of the n-side of the membrane and b6f complex to the cyclic electron transport chain indicate that the Q cycle in the oxygenic photosynthetic electron transport chain differs from those connected to the bc1 complex in the mitochondrial respiratory chain and the chain in photosynthetic bacteria. Inferences from the structure and C2 symmetry of the complex for the pathway of QH2/Q transfer

  5. Preoperative 3T high field blood oxygen level dependent functional magnetic resonance imaging for glioma involving sensory cortical areas

    Institute of Scientific and Technical Information of China (English)

    LI Shao-wu; WANG Jiang-fei; JIANG Tao; LI Shou-wei; ZHANG Wen-bo; LI Zi-xiao; ZHANG Zhong; DAI Jian-ping; WANG Zhong-cheng

    2010-01-01

    Background Localization of sensory cortical areas during the operation is essential to preserve the sensory function.Intraoperative direct electrostimulation under awake anesthesia is the golden standard but time-consuming. We applied 3T high field blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to identify the relationship between glioma and cortical sensory areas preoperatively and to guide intraoperative direct electrostimulation for quick and precise localization.Methods Five glioma patients with sensory cortex involvement by or next to the lesion had preoperative BOLD fMRI to determine the spatial relationship of cortical sensory areas to the tumours. Bilateral hand opposite movement was performed by these patients for fMRI. Precentral and postcentral gyri were identified by electrical stimulation during the operation. Karnofsky Performance Status scores of the patients' pre- and postoperative and the role of BOLD fMRI were evaluated.Results The cortical sensory areas were all activated in five glioma patients involving postcentral gyrus areas by BOLDf MRI with bilateral hand opposite movement. The detected activation areas corresponded with the results from cortical electrical stimulation.Conclusions The relationship between cortical sensory areas and tumour can be accurately shown by BOLD fMRI before operation. And the information used to make the tumour resection could obtain good clinical results.

  6. Ionic Liquids as Multi-Functional Lubricant Additives to Enhance Engine Efficiency (final report NFE-12-03876)

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jun [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Luo, Huimin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Toops, Todd J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); West, Brian H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Blau, Peter Julian [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dai, Sheng [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Papke, Brian L. [Shell Global Solutions, Houston, TX (United States); Gao, Hong [Shell Global Solutions, Houston, TX (United States); Kheireddin, Bassem [Shell Global Solutions, Houston, TX (United States); Chen, Cheng [Shell Global Solutions, Houston, TX (United States)

    2016-04-01

    This ORNL-Shell CRADA developed and investigated ionic liquids (ILs) as multifunctional additives for next-generation low-viscosity engine oils. Several groups of oil-miscible ILs were successfully designed and synthesized with high thermal stability, non-corrosiveness, excellent wettability, and most importantly effective anti-scuffing/anti-wear and friction reduction characteristics. Synergistic effects between the common anti-wear additive zinc dialkyldithiophosphate (ZDDP) and a particular group of ILs were discovered with > 30% friction reduction and 70% wear reduction compared with using ZDDP or IL alone. The IL+ZDDP tribofilm distinguishes itself from the IL or ZDDP tribofilms with substantially higher contents of metal phosphates but less metal oxides and sulfur compounds. Notably, it was revealed that the actual concentrations of functional elements on the droplet surface of the oil containing IL+ZDDP are one order magnitude higher than their nominal values. Such significantly increased concentrations of anti-wear agents are presumably expected for the oilsolid interface and believed to be responsible for the superior lubricating performance. A prototype SAE 0W-16 engine oil using a synergistic IL+ZDDP pair as the anti-wear additive has been formulated based on the compatibility between the IL and other additives. Sequence VIE full-scale engine dynamometer tests demonstrated fuel economy improvement (FEI) for this prototype oil and revealed the individual contributions from the lower oil viscosity and reduced boundary friction. The impact of IL and IL+ZDDP on exhaust emission catalyst was investigated using an accelerated small engine aging test and results were benchmarked against ZDDP.

  7. Effect of transition metal Fe adsorption on CeO2 (110) surface in the methane activation and oxygen vacancy formation: A density functional theory study

    Science.gov (United States)

    Tian, Dong; Zeng, Chunhua; Wang, Hua; Cheng, Xianming; Zheng, Yane; Xiang, Chao; Wei, Yonggang; Li, Kongzhai; Zhu, Xing

    2017-09-01

    Methane activation and oxygen vacancy formation over transition metal Fe adsorption on CeO2 (110) are studied by using the method of density functional theory (DFT) + U method. A set of model configurations are generated by placing Fe at five surface sites, viz., O-top site, O-bridge site, Ce-bridge site, Ce-top and double oxygen-bridge sites. The study shows that the energetically most favorable configuration is Fe adsorption at the double oxygen-bridge site. Based on the calculated surface, subsurface and the second oxygen vacancies formation energy with (or without) Fe adsorption, it shows that the Fe adsorption is in favor of the surface, subsurface and second oxygen vacancies formation. For the surface and subsurface oxygen vacancy on the Fe/CeO2 (110) surface, the main factor responsible for lowering of Evac is that the adsorption induces structural distortions, whereas, for the second oxygen vacancy, half can be attributed to the large structural relaxation, half can be attributed to the electronic effects. After calculating and discussing about the CH4 activation on CeO2 (110) and Fe/CeO2 (110) surface with (or without) the surface or subsurface oxygen vacancies at the possible adsorption sites, the results show that when the CH4 adsorbed on the Fe/CeO2 (110) with the surface oxygen vacancy at the Ce1 and Ce2 sites, the CH4 decomposed into the CH(ads) and H(ads), its belongs to the chemical absorption, whereas, when the CH4 adsorbed on the other possible sites, the mentioned phenomenon is not occurred, its belongs to the physical absorption. This study reveals the correlation between surface reducibility and catalytic activity for methane oxidation on cerium-based materials, which might be beneficial in developing improved catalysts for methane combustion.

  8. Curcumin protects neurons against oxygen-glucose deprivation/reoxygenation-induced injury through activation of peroxisome proliferator-activated receptor-γ function.

    Science.gov (United States)

    Liu, Zun-Jing; Liu, Hong-Qiang; Xiao, Cheng; Fan, Hui-Zhen; Huang, Qing; Liu, Yun-Hai; Wang, Yu

    2014-11-01

    The turmeric derivative curcumin protects against cerebral ischemic injury. We previously demonstrated that curcumin activates peroxisome proliferator-activated receptor-γ (PPARγ), a ligand-activated transcription factor involved in both neuroprotective and anti-inflammatory signaling pathways. This study tested whether the neuroprotective effects of curcumin against oxygen-glucose deprivation/reoxygenation (OGD/R)-induced injury of rat cortical neurons are mediated (at least in part) by PPARγ. Curcumin (10 μM) potently enhanced PPARγ expression and transcriptional activity following OGD/R. In addition, curcumin markedly increased neuronal viability, as evidenced by decreased lactate dehydrogenase release and reduced nitric oxide production, caspase-3 activity, and apoptosis. These protective effects were suppressed by coadministration of the PPARγ antagonist 2-chloro-5-nitrobenzanilide (GW9662) and by prior transfection of a small-interfering RNA (siRNA) targeting PPARγ, treatments that had no toxic effects on healthy neurons. Curcumin reduced OGD/R-induced accumulation of reactive oxygen species and inhibited the mitochondrial apoptosis pathway, as indicated by reduced release of cytochrome c and apoptosis-inducing factor and maintenance of both the mitochondrial membrane potential and the Bax/Bcl-2 ratio. Again, GW9662 or PPARγ siRNA transfection mitigated the protective effects of curcumin on mitochondrial function. Curcumin suppressed IκB kinase phosphorylation and IκB degradation, thereby inhibiting nuclear factor-κ B (NF-κB) nuclear translocation, effects also blocked by GW9662 or PPARγ siRNA. Immunoprecipitation experiments revealed that PPARγ interacted with NF-κB p65 and inhibited NF-κB activation. The present study provides strong evidence that at least some of the neuroprotective effects of curcumin against OGD/R are mediated by PPARγ activation.

  9. Molybdenum-Doped PdPt@Pt Core-Shell Octahedra Supported by Ionic Block Copolymer-Functionalized Graphene as a Highly Active and Durable Oxygen Reduction Electrocatalyst.

    Science.gov (United States)

    Cho, Kie Yong; Yeom, Yong Sik; Seo, Heun Young; Kumar, Pradip; Lee, Albert S; Baek, Kyung-Youl; Yoon, Ho Gyu

    2017-01-18

    Development of highly active and durable electrocatalysts that can effectively electrocatalyze oxygen reduction reactions (ORR) still remains one important challenge for high-performance electrochemical conversion and storage applications such as fuel cells and metal-air batteries. Herein, we propose the combination of molybdenum-doped PdPt@Pt core-shell octahedra and the pyrene-functionalized poly(dimethylaminoethyl methacrylate)-b-poly[(ethylene glycol) methyl ether methacrylate] ionic block copolymer-functionalized reduced graphene oxide (Mo-PdPt@Pt/IG) to effectively augment the interfacial cohesion of both components using a tunable ex situ mixing strategy. The rationally designed Mo-PdPt@Pt core-shell octahedra have unique compositional benefits, including segregation of Mo atoms on the vertexes and edges of the octahedron and 2-3 shell layers of Pt atoms on a PdPt alloy core, which can provide highly active sites to the catalyst for ORR along with enhanced electrochemical stability. In addition, the ionic block copolymer functionalized graphene can facilitate intermolecular charge transfer and good stability of metal NPs, which arises from the ionic block copolymer interfacial layer. When the beneficial features of the Mo-PdPt@Pt and IG are combined, the Mo-PdPt@Pt/IG exhibits substantially enhanced activity and durability for ORR relative to those of commercial Pt/C. Notably, the Mo-PdPt@Pt/IG shows mass activity 31-fold higher than that of Pt/C and substantially maintains high activities after 10 000 cycles of intensive durability testing. The current study highlights the crucial strategies in designing the highly active and durable Pt-based octahedra and effective combination with functional graphene supports toward the synergetic effects on ORR.

  10. Effect of additive particles on mechanical, thermal, and cell functioning properties of poly(methyl methacrylate cement

    Directory of Open Access Journals (Sweden)

    Khandaker M

    2014-05-01

    Full Text Available Morshed Khandaker,1 Melville B Vaughan,2 Tracy L Morris,3 Jeremiah J White,1 Zhaotong Meng1 1Department of Engineering and Physics, 2Department of Biology, 3Department of Mathematics and Statistics, University of Central Oklahoma, Edmond, OK, USA Abstract: The most common bone cement material used clinically today for orthopedic surgery is poly(methyl methacrylate (PMMA. Conventional PMMA bone cement has several mechanical, thermal, and biological disadvantages. To overcome these problems, researchers have investigated combinations of PMMA bone cement and several bioactive particles (micrometers to nanometers in size, such as magnesium oxide, hydroxyapatite, chitosan, barium sulfate, and silica. A study comparing the effect of these individual additives on the mechanical, thermal, and cell functional properties of PMMA would be important to enable selection of suitable additives and design improved PMMA cement for orthopedic applications. Therefore, the goal of this study was to determine the effect of inclusion of magnesium oxide, hydroxyapatite, chitosan, barium sulfate, and silica additives in PMMA on the mechanical, thermal, and cell functional performance of PMMA. American Society for Testing and Materials standard three-point bend flexural and fracture tests were conducted to determine the flexural strength, flexural modulus, and fracture toughness of the different PMMA samples. A custom-made temperature measurement system was used to determine maximum curing temperature and the time needed for each PMMA sample to reach its maximum curing temperature. Osteoblast adhesion and proliferation experiments were performed to determine cell viability using the different PMMA cements. We found that flexural strength and fracture toughness were significantly greater for PMMA specimens that incorporated silica than for the other specimens. All additives prolonged the time taken to reach maximum curing temperature and significantly improved cell

  11. Information technology - Telecommunications and information exchange between systems - Private integrated services network - Specification, functional model and information flows - Call interception additional network feature

    CERN Document Server

    International Organization for Standardization. Geneva

    2003-01-01

    Information technology - Telecommunications and information exchange between systems - Private integrated services network - Specification, functional model and information flows - Call interception additional network feature

  12. Effects of long-term low-dose oxygen supplementation on the epithelial function, collagen metabolism and interstitial fibrogenesis in the guinea pig lung

    Directory of Open Access Journals (Sweden)

    Ishizaka Akitoshi

    2008-04-01

    Full Text Available Abstract Background The patient population receiving long-term oxygen therapy has increased with the rising morbidity of COPD. Although high-dose oxygen induces pulmonary edema and interstitial fibrosis, potential lung injury caused by long-term exposure to low-dose oxygen has not been fully analyzed. This study was designed to clarify the effects of long-term low-dose oxygen inhalation on pulmonary epithelial function, edema formation, collagen metabolism, and alveolar fibrosis. Methods Guinea pigs (n = 159 were exposed to either 21% or 40% oxygen for a maximum of 16 weeks, and to 90% oxygen for a maximum of 120 hours. Clearance of inhaled technetium-labeled diethylene triamine pentaacetate (Tc-DTPA and bronchoalveolar lavage fluid-to-serum ratio (BAL/Serum of albumin (ALB were used as markers of epithelial permeability. Lung wet-to-dry weight ratio (W/D was measured to evaluate pulmonary edema, and types I and III collagenolytic activities and hydroxyproline content in the lung were analyzed as indices of collagen metabolism. Pulmonary fibrotic state was evaluated by histological quantification of fibrous tissue area stained with aniline blue. Results The clearance of Tc-DTPA was higher with 2 week exposure to 40% oxygen, while BAL/Serum Alb and W/D did not differ between the 40% and 21% groups. In the 40% oxygen group, type I collagenolytic activities at 2 and 4 weeks and type III collagenolytic activity at 2 weeks were increased. Hydroxyproline and fibrous tissue area were also increased at 2 weeks. No discernible injury was histologically observed in the 40% group, while progressive alveolar damage was observed in the 90% group. Conclusion These results indicate that epithelial function is damaged, collagen metabolism is affected, and both breakdown of collagen fibrils and fibrogenesis are transiently induced even with low-dose 40% oxygen exposure. However, these changes are successfully compensated even with continuous exposure to low

  13. Functionalization of vertically aligned carbon nanotubes with polystyrene via surface initiated reversible addition fragmentation chain transfer polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Macdonald, Thomas; Gibson, Christopher T.; Constantopoulos, Kristina; Shapter, Joseph G. [Flinders Centre for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA, 5001 (Australia); Ellis, Amanda V., E-mail: amanda.ellis@flinders.edu.au [Flinders Centre for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA, 5001 (Australia)

    2012-01-15

    Here we demonstrate the covalent attachment of vertically aligned (VA) acid treated single-walled carbon nanotubes (SWCNTs) onto a silicon substrate via dicyclohexylcarbodiimide (DCC) coupling chemistry. Subsequently, the pendant carboxyl moieties on the sidewalls of the VA-SWCNTs were derivatized to acyl chlorides, and then finally to bis(dithioester) moieties using a magnesium chloride dithiobenzoate salt. The bis(dithioester) moieties were then successfully shown to act as a chain transfer agent (CTA) in the reversible addition fragmentation chain transfer (RAFT) polymerization of styrene in a surface initiated 'grafting-from' process from the VA-SWCNT surface. Atomic force microscopy (AFM) verified vertical alignment of the SWCNTs and the maintenance thereof throughout the synthesis process. Finally, Raman scattering spectroscopy and AFM confirmed polystyrene functionalization.

  14. Correlation function of an optical bistable system with cross-correlated additive white noise and multiplicative colored noise

    Institute of Scientific and Technical Information of China (English)

    Bing Wang; Shaoping Yan

    2009-01-01

    Considering an optical bistable system with cross-correlated additive white noise and multiplicative colored noise,we study the effects of correlation between the noises on the correlation function C(s)using the unified colored noise approximation and the Stratonovich decoupling ansatz formalism.The effects of the self-correlation time T of the multiplicative colored noise and the correlation intensity A between the two noises are studied with numerical calculation.It is found that C(s)increases with the increase of the self-correlation time r,but decreases with the increase of the correlation intensity A.At large value of T,there is almost no change for C(s)when T changes.

  15. Composite scaffolds for osteochondral repair obtained by combination of additive manufacturing, leaching processes and hMSC-CM functionalization.

    Science.gov (United States)

    Díaz Lantada, Andrés; Alarcón Iniesta, Hernán; García-Ruíz, Josefa Predestinación

    2016-02-01

    Articular repair is a relevant and challenging area for the emerging fields of tissue engineering and biofabrication. The need of significant gradients of properties, for the promotion of osteochondral repair, has led to the development of several families of composite biomaterials and scaffolds, using different effective approaches, although a perfect solution has not yet been found. In this study we present the design, modeling, rapid manufacturing and in vitro testing of a composite scaffold aimed at osteochondral repair. The presented composite scaffold stands out for having a functional gradient of density and stiffness in the bony phase, obtained in titanium by means of computer-aided design combined with additive manufacture using selective laser sintering. The chondral phase is obtained by sugar leaching, using a PDMS matrix and sugar as porogen, and is joined to the bony phase during the polymerization of PDMS, therefore avoiding the use of supporting adhesives or additional intermediate layers. The mechanical performance of the construct is biomimetic and the stiffness values of the bony and chondral phases can be tuned to the desired applications, by means of controlled modifications of different parameters. A human mesenchymal stem cell (h-MSC) conditioned medium (CM) is used for improving scaffold response. Cell culture results provide relevant information regarding the viability of the composite scaffolds used. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Is functional hypertrophy and specific force coupled with the addition of myonuclei at the single muscle fiber level?

    Science.gov (United States)

    Qaisar, Rizwan; Renaud, Guillaume; Morine, Kevin; Barton, Elisabeth R; Sweeney, H Lee; Larsson, Lars

    2012-03-01

    Muscle force is typically proportional to muscle size, resulting in constant force normalized to muscle fiber cross-sectional area (specific force). Mice overexpressing insulin-like growth factor-1 (IGF-1) exhibit a proportional gain in muscle force and size, but not the myostatin-deficient mice. In an attempt to explore the role of the cytoplasmic volume supported by individual myonuclei [myonuclear domain (MND) size] on functional capacity of skeletal muscle, we have investigated specific force in relation to MND and the content of the molecular motor protein, myosin, at the single muscle fiber level from myostatin-knockout (Mstn(-/-)) and IGF-1-overexpressing (mIgf1(+/+)) mice. We hypothesize that the addition of extra myonuclei is a prerequisite for maintenance of specific force during muscle hypertrophy. A novel algorithm was used to measure individual MNDs in 3 dimensions along the length of single muscle fibers from the fast-twitch extensor digitorum longus and the slow-twitch soleus muscle. A significant effect of the size of individual MNDs in hypertrophic muscle fibers on both specific force and myosin content was observed. This effect was muscle cell type specific and suggested there is a critical volume individual myonuclei can support efficiently. The large MNDs found in fast muscles of Mstn(-/-) mice were correlated with the decrement in specific force and myosin content in Mstn(-/-) muscles. Thus, myostatin inhibition may not be able to maintain the appropriate MND for optimal function.

  17. Additive effect of smoking and cotton dust exposure on respiratory symptoms and pulmonary function of cotton textile workers.

    Science.gov (United States)

    Su, Yih-Ming; Su, Jenn-Rong; Sheu, Jia-Yih; Loh, Ching-Hui; Liou, Saou-Hsing

    2003-04-01

    One hundred and sixty-nine and 175 cotton textile workers (CTWs) were enrolled in the first (1991) and second (1996) surveys to investigate the prevalence of byssinosis. The synergistic effect of smoking on cotton dust exposure was also evaluated. Although the difference in prevalence of abnormal pulmonary function between the first (38.5%) and second study (38.9%) was not statistically significant, smokers had significantly higher frequency than nonsmokers in both surveys. A significant trend existed between the cotton dust levels and the frequency of abnormal lung function. The significant trend was also noted in both smokers and nonsmokers. The frequency of respiratory symptoms and the prevalence of severe byssinosis in the second survey (14.9% and 12.6%, respectively) were significantly lower than that in the first survey (39.7% and 21.9%, respectively). The reduction of symptoms was due to remodeling of this old cotton mill. The prevalences of respiratory symptoms and byssinosis in smokers being significantly higher than in nonsmokers only found in the first survey, but not found in the second survey. These results indicate that smoking potentiates the effect of cotton dust exposure on respiratory symptoms and byssinosis. The second study reveals high prevalence of byssinosis still existed in Taiwanese cotton mill, although the prevalence was declining. Smoking was found to show an additive effect on cotton dust exposure. Anti-smoking campaign, occupational health program to reduce the dust exposure, and periodical medical examination are measures to prevent from byssinosis.

  18. Periodic density functional theory study of ethylene hydrogenation over Co{sub 3}O{sub 4} (1 1 1) surface: The critical role of oxygen vacancies

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Jinhui; Song, JiaJia; Niu, Hongling; Pan, Lun; Zhang, Xiangwen; Wang, Li [Key Laboratory for Green Chemical Technology of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University (China); Collaborative Innovative Center of Chemical Science and Engineering (Tianjin), Tianjin 300072 (China); Zou, Ji-Jun, E-mail: jj_zou@tju.edu.cn [Key Laboratory for Green Chemical Technology of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University (China); Collaborative Innovative Center of Chemical Science and Engineering (Tianjin), Tianjin 300072 (China)

    2016-05-15

    Highlights: • H{sub 2} dissociates in heterolytic way following H atoms migration to form O−H bond. • H{sub 2} dissociation occurs at low temperature on perfect and oxygen defective Co{sub 3}O{sub 4}. • Oxygen vacancy promotes hydrogenation thermodynamically and kinetically. • O−H bond is weakened on oxygen defective surface. • Hydrogenation requires compromise between H−H activation and O−H breakage. - Abstract: Recently, metal oxides are attracting increasing interests as hydrogenation catalyst. Herein we studied the hydrogenation of ethylene on perfect and oxygen defective Co{sub 3}O{sub 4} (1 1 1) using periodic density functional theory. The energetics and pathways of ethylene hydrogenation to ethane were determined. We have demonstrated that (i) H{sub 2} dissociation on Co{sub 3}O{sub 4} is a complicated two-step process through a heterolytic cleavage, followed by the migration of H atom and finally yields the homolytic product on both perfect and oxygen defective Co{sub 3}O{sub 4} (1 1 1) surfaces easily. (ii) After introducing the surface oxygen vacancy, the stepwise hydrogenation of ethylene by atomic hydrogen is much easier than that on perfect surface due to the weaker bond strength of OH group. The strength of O−H bond is a crucial factor for the hydrogenation reaction which involves the breakage of O−H bond. The formation of oxygen vacancy increases the electronic charges at the adjacent surface O, which reduces its capability of further gaining electrons from adsorbed atomic hydrogen and then weakens the strength of O−H bond. These results emphasize the importance of the oxygen vacancies for hydrogenation on metal oxides.

  19. The addition of functional task-oriented mental practice to conventional physical therapy improves motor skills in daily functions after stroke

    Directory of Open Access Journals (Sweden)

    Clarissa C. Santos-Couto-Paz

    2013-12-01

    Full Text Available BACKGROUND: Mental practice (MP is a cognitive strategy which may improve the acquisition of motor skills and functional performance of athletes and individuals with neurological injuries. OBJECTIVE: To determine whether an individualized, specific functional task-oriented MP, when added to conventional physical therapy (PT, promoted better learning of motor skills in daily functions in individuals with chronic stroke (13±6.5 months post-stroke. METHOD: Nine individuals with stable mild and moderate upper limb impairments participated, by employing an A1-B-A2 single-case design. Phases A1 and A2 included one month of conventional PT, and phase B the addition of MP training to PT. The motor activity log (MAL-Brazil was used to assess the amount of use (AOU and quality of movement (QOM of the paretic upper limb; the revised motor imagery questionnaire (MIQ-RS to assess the abilities in kinesthetic and visual motor imagery; the Minnesota manual dexterity test to assess manual dexterity; and gait speed to assess mobility. RESULTS: After phase A1, no significant changes were observed for any of the outcome measures. However, after phase B, significant improvements were observed for the MAL, AOU and QOM scores (p<0.0001, and MIQ-RS kinesthetic and visual scores (p=0.003; p=0.007, respectively. The significant gains in manual dexterity (p=0.002 and gait speed (p=0.019 were maintained after phase A2. CONCLUSIONS: Specific functional task-oriented MP, when added to conventional PT, led to improvements in motor imagery abilities combined with increases in the AOU and QOM in daily functions, manual dexterity, and gait speed.

  20. Multi-regional investigation of the relationship between functional MRI blood oxygenation level dependent (BOLD activation and GABA concentration.

    Directory of Open Access Journals (Sweden)

    Ashley D Harris

    Full Text Available Several recent studies have reported an inter-individual correlation between regional GABA concentration, as measured by MRS, and the amplitude of the functional blood oxygenation level dependent (BOLD response in the same region. In this study, we set out to investigate whether this coupling generalizes across cortex. In 18 healthy participants, we performed edited MRS measurements of GABA and BOLD-fMRI experiments using regionally related activation paradigms. Regions and tasks were the: occipital cortex with a visual grating stimulus; auditory cortex with a white noise stimulus; sensorimotor cortex with a finger-tapping task; frontal eye field with a saccade task; and dorsolateral prefrontal cortex with a working memory task. In contrast to the prior literature, no correlation between GABA concentration and BOLD activation was detected in any region. The origin of this discrepancy is not clear. Subtle differences in study design or insufficient power may cause differing results; these and other potential reasons for the discrepant results are discussed. This negative result, although it should be interpreted with caution, has a larger sample size than prior positive results, and suggests that the relationship between GABA and the BOLD response may be more complex than previously thought.

  1. Partition coefficients for iron between plagioclase and basalt as a function of oxygen fugacity - Implications for Archean and lunar anorthosites

    Science.gov (United States)

    Phinney, W. C.

    1992-01-01

    As a prelude to determinations of the content of total iron as FeO(T) in melts in equilibrium with calcic anorthosites, the partition coefficients (Ds) for FeO(T) between calcic plagioclase and basaltic melt were determined, as a function of oxygen fugacity (f(O2)), for a basaltic composition that occurs as matrices for plagioclase megacrysts. Results showed that, at the liquidus conditions, the value of D for FeO(T) between calcic plagioclase and tholeiitic basalt changed little (from 0.030 to 0.044) between the very low f(O2) of the iron-wustite buffer and that of the quartz-fayalite-magnetite (QFM) buffer. At fugacities above QFM, the value for D increased rapidly to 0.14 at the magnetite-hematite buffer and to 0.33 in air. The increase in D results from the fact that, at f(O2) below QFM, nearly all of the Fe is in the Fe(2+) state; above QFM, the Fe(3+)/Fe(2+) ratio in the melt increases rapidly, causing more Fe to enter the plagioclase which accepts Fe(3+) more readily than Fe(2+).

  2. The influence of oxygen-containing functional groups on the dispersion of single-walled carbon nanotubes in amide solvents

    Science.gov (United States)

    Brandão, S. D. F.; Andrada, D.; Mesquita, A. F.; Santos, A. P.; Gorgulho, H. F.; Paniago, R.; Pimenta, M. A.; Fantini, C.; Furtado, C. A.

    2010-08-01

    Surface composition plays an important role in carbon nanotube dispersibility in different environments. Indeed, it determines the choice of dispersion medium. In this paper the effect of oxidation on the dispersion of HiPCO single-walled carbon nanotubes (SWNTs) in N-methyl-pyrrolidinone (NMP), N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMA), N-dodecyl-pyrrolidinone (N12P) and cyclohexyl-pyrrolidinone (CHP) was systematically studied. During the oxidation process, similar amounts of carboxylic acid and phenolic groups were introduced to mostly already existing defects. For each solvent the dispersion limits and the absorption coefficients were estimated by optical absorption analysis over a range of SWNT concentrations. The presence of acid oxygenated groups increased SWNT dispersibility in NMP, DMF and DMA, but decreased in N12P and CHP. The absorption coefficients, however, decreased for all solvents after oxidation, reflecting the weakening of the effective transition dipole of the π-π transition with even limited extension functionalization and solvent interaction. The analysis of the results in terms of Hansen and Flory-Huggins solubility parameters evidenced the influence of dipolar interactions and hydrogen bonding on the dispersibility of oxidized SWNTs.

  3. Kinetics of the permanent deactivation of the boron-oxygen complex in crystalline silicon as a function of illumination intensity

    Science.gov (United States)

    Steckenreiter, Verena; Walter, Dominic C.; Schmidt, Jan

    2017-03-01

    Based on contactless carrier lifetime measurements performed on p-type boron-doped Czochralski-grown silicon (Cz-Si) wafers, we examine the rate constant Rde of the permanent deactivation process of the boron-oxygen-related defect center as a function of the illumination intensity I at 170°C. While at low illumination intensities, a linear increase of Rde on I is measured, at high illumination intensities, Rde seems to saturate. We are able to explain the saturation by assuming that Rde increases proportionally with the excess carrier concentration Δ n and take the fact into account that at sufficiently high illumination intensities, the carrier lifetime decreases with increasing Δ n and hence the slope of Δ n (I) decreases, leading to an apparent saturation. Importantly, on low-lifetime Cz-Si samples no saturation of the deactivation rate constant is observed for the same illumination intensities, proving that the deactivation is stimulated by the presence of excess electrons and not directly by the photons.

  4. Systematic investigation of the catalytic cycle of a single site ruthenium oxygen evolving complex using density functional theory.

    Science.gov (United States)

    Hughes, Thomas F; Friesner, Richard A

    2011-07-28

    The mechanism of water oxidation by a single site ruthenium oxygen evolving complex is investigated using fully unrestricted pseudospectral B3LYP with the effective core potential LACV3P in continuum solvent with some quantum mechanical waters. Guess wave functions have been used that allow greater flexibility in sampling different electronic configurations of the complex. Systematic comparison with experiment is improved using these guesses because they provide a complete analysis of the low energy manifold and help to alleviate the formal disconnect between theory and experiment in assigning Lewis structures for transition metal complexes. In agreement with results from the literature, the challenging 4e(-)and 4H(+) oxidation of water is accomplished using a mechanism that features three proton coupled electron transfers, one electron transfer, one atom proton transfer (APT), and one ligand exchange (LE). Calculations on a large database of ruthenium complexes allows us to benchmark the computation of reduction half potentials and free energies of activation and to investigate systematic ligand variations and their effect on the reaction mechanism. Mean unsigned errors of reduction half potentials in comparison to experiment are generally small (100-200 mV). The APT and LE steps are found to be rate limiting with free energy barriers of 19.27 and 19.53 kcal/mol respectively, which is in excellent agreement with the ∼20 kcal/mol barrier obtained from experimental rate constants using classical transition state theory.

  5. Functional Species Encapsulated in Nitrogen-Doped Porous Carbon as a Highly Efficient Catalyst for the Oxygen Reduction Reaction.

    Science.gov (United States)

    Song, Li; Wang, Tao; Ma, Yiou; Xue, Hairong; Guo, Hu; Fan, Xiaoli; Xia, Wei; Gong, Hao; He, Jianping

    2017-03-08

    The scarcity, high cost, and poor stability of precious metal-based electrocatalysts have stimulated the development of novel non-precious metal catalysts for the oxygen reduction reaction (ORR) for use in fuel cells and metal-air batteries. Here, we fabricated in situ a hybrid material (Co-W-C/N) with functional species (tungsten carbide and cobalt nanoparticles) encapsulated in an N-doped porous carbon framework, through a facile multi-constituent co-assembly method combined with subsequent annealing treatment. The unique structure favors the anchoring active nanoparticles and facilitates mass transfer steps. The homogenously distributed carbide nanoparticles and adjacent Co-N-C sites lead to the electrocatalytic synergism for the ORR. The existence of Co and W can promote the graphitization of the carbon matrix. Benefiting from its structural and material superiority, the Co-W-C/N electrocatalyst exhibits excellent electrocatalytic activity (with a half-wave potential of 0.774 V vs. reversible hydrogen electrode (RHE)), high stability (96.3 % of the initial current remaining after 9000 s of continuous operation), and good immunity against methanol in alkaline media.

  6. Oxygen as a regulator of MA-10 cell functions: effect of cobalt chloride on vascular endothelial growth factor production.

    Science.gov (United States)

    Kumar, A; Rani, L; Dhole, B; Chaturvedi, P K

    2012-05-01

    Mammalian testis functions at a temperature and oxygen tension (pO(2)) lower than the core body. Hypoxia-inducible factor-1α (HIF-1α) mediates the adaptive responses to hypoxia such as production of angiogenic vascular endothelial growth factor (VEGF) in a variety of cells and tissues. VEGF production in Leydig cells is stimulated by luteinising hormone (LH)/cAMP. We have conducted experiments to find out whether HIF-1α is involved in LH/cAMP-induced secretion of VEGF by Leydig cell-derived MA-10 cells. Both cobalt chloride (CoCl(2)), an inducer of hypoxia, and 8-Br-cAMP enhanced HIF-1α activity followed by an increase in VEGF secretion. However, there was no change in mRNA levels of HIF-1α. Inhibition of HIF-1α activity by cyclosporine A (CsA) inhibited a rise in VEGF production in response to CoCl(2) as well as 8-Br-cAMP. Inhibitors of protein kinase A (PKA), extracellular regulated kinase 1/2 (ERK1/2) and phosphatidyl inositol-3 kinase/Akt (PI3-K/Akt) inhibited the increase in VEGF levels in response to both CoCl(2) and 8-Br-cAMP. The data suggest that HIF-1α is a mediator of hypoxia- as well as 8-Br-cAMP-stimulated production of VEGF in MA-10 cells; both the stimuli act through a common signalling cascade.

  7. Renal function and peak exercise oxygen consumption in chronic heart failure with reduced left ventricular ejection fraction.

    Science.gov (United States)

    Scrutinio, Domenico; Agostoni, Piergiuseppe; Gesualdo, Loreto; Corrà, Ugo; Mezzani, Alessandro; Piepoli, Massimo; Di Lenarda, Andrea; Iorio, Annamaria; Passino, Claudio; Magrì, Damiano; Masarone, Daniele; Battaia, Elisa; Girola, Davide; Re, Federica; Cattadori, Gaia; Parati, Gianfranco; Sinagra, Gianfranco; Villani, Giovanni Quinto; Limongelli, Giuseppe; Pacileo, Giuseppe; Guazzi, Marco; Metra, Marco; Frigerio, Maria; Cicoira, Mariantonietta; Minà, Chiara; Malfatto, Gabriella; Caravita, Sergio; Bussotti, Maurizio; Salvioni, Elisabetta; Veglia, Fabrizio; Correale, Michele; Scardovi, Angela B; Emdin, Michele; Giannuzzi, Pantaleo; Gargiulo, Paola; Giovannardi, Marta; Perrone-Filardi, Pasquale; Raimondo, Rosa; Ricci, Roberto; Paolillo, Stefania; Farina, Stefania; Belardinelli, Romualdo; Passantino, Andrea; La Gioia, Rocco

    2015-01-01

    Chronic kidney disease is associated with sympathetic activation and muscle abnormalities, which may contribute to decreased exercise capacity. We investigated the correlation of renal function with peak exercise oxygen consumption (V̇O2) in heart failure (HF) patients. METHODS AND RESULTS: We recruited 2,938 systolic HF patients who underwent clinical, laboratory, echocardiographic and cardiopulmonary exercise testing. The patients were stratified according to estimated glomerular filtration rate (eGFR). Mean follow-up was 3.7 years. The primary outcome was a composite of cardiovascular death and urgent heart transplantation at 3 years. On multivariable regression, eGFR was predictor of peakV̇O2(Pheart rate, B-type natriuretic peptide, hemoglobin, and treatment. After adjusting for significant covariates, the hazard ratio for primary outcome associated with peakV̇O2<12 ml·kg(-1)·min(-1)was 1.75 (95% confidence interval (CI): 1.06-2.91; P=0.0292) in patients with eGFR ≥60, 1.77 (0.87-3.61; P=0.1141) in those with eGFR of 45-59, and 2.72 (1.01-7.37; P=0.0489) in those with eGFR <45 ml·min(-1)·1.73 m(-2). The area under the receiver-operating characteristic curve for peakV̇O2<12 ml·kg(-1)·min(-1)was 0.63 (95% CI: 0.54-0.71), 0.67 (0.56-0.78), and 0.57 (0.47-0.69), respectively. Testing for interaction was not significant. Renal dysfunction is correlated with peakV̇O2. A peakV̇O2cutoff of 12 ml·kg(-1)·min(-1)offers limited prognostic information in HF patients with more severely impaired renal function.

  8. Functional MoS2 by the Co/Ni doping as the catalyst for oxygen reduction reaction

    Science.gov (United States)

    Xiao, B. B.; Zhang, P.; Han, L. P.; Wen, Z.

    2015-11-01

    Since the discovery of the oxygen reduction reaction (ORR) activity of the metal phthalocyanine, the great enthusiasm is ignited for searching the catalysts with low price replacing Pt-based catalysts. Here, the catalytic activities for the ORR on the Co or Ni doped MoS2 are studied by using density-functional theory (DFT). It is found that Co/MoS2 resembles FeN4 active site while Ni/MoS2 is similar with CoN4 active site. In details, for Co/MoS2, under the acid medium, the rate-determining step (RDS) is located at the second H2O formation with a barrier of 1.49 eV. While under the alkaline medium, RDS is the final OH- formation with the barrier of 0.94 eV. For Ni/MoS2, under the acid medium, the RDS is the same as that of Co/MoS2 with a barrier of 0.87 eV. However, RDS is the O formation with the barrier of 0.92 eV under the alkaline medium. Furthermore, due to the intact HOOH adsorption, it is expected that the 2e- ORR is present on Ni/MoS2, which means inferior activity compared with Co/MoS2. Our calculation demonstrates the ability to functionalize inert materials for the ORR and provides new materials to design effective Pt-free catalysts for fuel-cell technology.

  9. Redox function of tetrahydrobiopterin and effect of L-arginine on oxygen binding in endothelial nitric oxide synthase.

    Science.gov (United States)

    Berka, Vladimir; Yeh, Hui-Chun; Gao, De; Kiran, Farheen; Tsai, Ah-Lim

    2004-10-19

    Tetrahydrobiopterin (BH(4)), not dihydrobiopterin or biopterin, is a critical element required for NO formation by nitric oxide synthase (NOS). To elucidate how BH(4) affects eNOS activity, we have investigated BH(4) redox functions in the endothelial NOS (eNOS). Redox-state changes of BH(4) in eNOS were examined by chemical quench/HPLC analysis during the autoinactivation of eNOS using oxyhemoglobin oxidation assay for NO formation at room temperature. Loss of NO formation activity linearly correlated with BH(4) oxidation, and was recovered by overnight incubation with fresh BH(4). Thus, thiol reagents commonly added to NOS enzyme preparations, such as dithiothreitol and beta-mercaptoethanol, probably preserve enzyme activity by preventing BH(4) oxidation. It has been shown that conversion of L-arginine to N-hydroxy-L-arginine in the first step of NOS catalysis requires two reducing equivalents. The first electron that reduces ferric to the ferrous heme is derived from flavin oxidation. The issue of whether BH(4) supplies the second reducing equivalent in the monooxygenation of eNOS was investigated by rapid-scan stopped-flow and rapid-freeze-quench EPR kinetic measurements. In the presence of L-arginine, oxygen binding kinetics to ferrous eNOS or to the ferrous eNOS oxygenase domain (eNOS(ox)) followed a sequential mechanism: Fe(II) Fe(II)O(2) --> Fe(III) + O(2)(-). Without L-arginine, little accumulation of the Fe(II)O(2) intermediate occurred and essentially a direct optical transition from the Fe(II) form to the Fe(III) form was observed. Stabilization of the Fe(II)O(2) intermediate by L-arginine has been established convincingly. On the other hand, BH(4) did not have significant effects on the oxygen binding and decay of the oxyferrous intermediate of the eNOS or eNOS oxygenase domain. Rapid-freeze-quench EPR kinetic measurements in the presence of L-arginine showed a direct correlation between BH(4) radical formation and decay of the Fe(II)O(2) intermediate

  10. Picroside Ⅱ inhibits hypoxia/reoxygenation-induced cardiomyocyte apoptosis by ameliorating mitochondrial function through a mechanism involving a decrease in reactive oxygen species production.

    Science.gov (United States)

    Li, Jian-Zhe; Yu, Shu-Yi; Mo, Dan; Tang, Xiu-Neng; Shao, Qing-Rui

    2015-02-01

    Reactive oxygen species (ROS)‑induced mitochondrial dysfunction plays an important role in cardiomyocyte apoptosis during myocardial ischemia/reperfusion (I/R) injury. Picroside Ⅱ, isolated from Picrorhiza scrophulariiflora Pennell (Scrophulariaceae), has been reported to protect cardiomyocytes from hypoxia/reoxygenation (H/R)‑induced apoptosis, but the exact mechanism is not fully clear. The aim of the present study was to explore the protective effects of picroside Ⅱ on H/R‑induced cardiomyocyte apoptosis and the underlying mechanism. In the H9c2 rat cardiomyocyte cell line, picroside Ⅱ (100 µg/ml) was added for 48 h prior to H/R. The results showed that picroside Ⅱ markedly inhibited H/R‑induced cardiomyocyte apoptosis. In addition, picroside Ⅱ was also able to decrease the opening degree of mitochondrial permeability transition pore (mPTP), increase the mitochondrial membrane potential, inhibit cytochrome c release from mitochondria to cytosol and downregulate caspase‑3 expression and activity concomitantly with the decreased ROS production. These results suggested that picroside Ⅱ inhibited H/R‑induced cardiomyocyte apoptosis by ameliorating mitochondrial function through a mechanism involving a decrease in ROS production.

  11. A role of nanotube dangling pyrrole and oxygen functions in the electrochemical synthesis of polypyrrole/MWCNTs hybrid materials

    Energy Technology Data Exchange (ETDEWEB)

    Krukiewicz, Katarzyna, E-mail: katarzyna.krukiewicz@polsl.pl [Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, Strzody 9, 44-100 Gliwice (Poland); Herman, Artur P., E-mail: artur.herman@polsl.pl [Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Silesian University of Technology, Krzywoustego 4, Gliwice 44-100 (Poland); Turczyn, Roman, E-mail: roman.turczyn@polsl.pl [Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, Strzody 9, 44-100 Gliwice (Poland); Szymańska, Katarzyna, E-mail: katarzyna.szymanska@polsl.pl [Department of Chemical and Process Engineering, Silesian University of Technology, Strzody 7, 44-100 Gliwice (Poland); Koziol, Krzysztof K.K., E-mail: kk292@cam.ac.uk [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Boncel, Sławomir, E-mail: slawomir.boncel@polsl.pl [Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Silesian University of Technology, Krzywoustego 4, Gliwice 44-100 (Poland); Zak, Jerzy K., E-mail: jerzy.zak@polsl.pl [Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, Strzody 9, 44-100 Gliwice (Poland)

    2014-10-30

    Highlights: • The effect of MWCNT functionalization on properties of PPy composites was explained. • The behavior of pristine, pyrrole-modified and oxidized MWCNT was explained. • Functionalization of MWCNT improved their dispersibility and processability. • Different mechanisms of (f-)MWCNT incorporation into PPy composites were explained. • Orientation of growing PPy chains was tailored through the addition of (f-)MWCNT. - Abstract: The effect of the functionalization of multi-walled carbon nanotubes (MWCNTs) on the process of electrochemical co-deposition of MWCNTs and polypyrrole (PPy), as well as the morphology of obtained composites have been demonstrated. As the nanotube components of the hybrids, three types of MWCNT were used, namely c-CVD derived (pristine) MWCNTs, their oxidized counterparts MWCNT-Ox and pyrrole-modified MWCNT-Py. The stability of pristine and functionalized MWCNTs (f-MWCNT) dispersions in tetrahydrofuran and water was studied together with the description of the process of formation PPy/(f-)MWCNT hybrid materials via electrochemical co-deposition. The structural and morphological properties of the hybrids were characterized by Raman spectroscopy, scanning electron microscopy and atomic force microscopy revealing substantial differences among hybrid materials in their surface morphology and the influence of MWCNT functionalization on the orientation of growing PPy chains.

  12. Influence of recombinant human brain natriuretic peptide on myocardial enzymes, serum cardiac function indexes and oxygen metabolism of patients with open heart surgery with cardiopulmonary bypass

    Institute of Scientific and Technical Information of China (English)

    Shu-Tian Song; Ming Yang; Kun-Peng Li; Juan Xu; Chuan-Ming Bai; Ji-Wu Zhou

    2016-01-01

    Objective:To investigate and analyze the influence of recombinant human brain natriuretic peptide on myocardial enzymes, serum cardiac function indexes and oxygen metabolism of patients with open heart surgery with cardiopulmonary bypass.Methods:A total of 42 patients with open heart surgery with cardiopulmonary bypass during the period of June 2014 to January 2016 were randomly divided into the control group of 21 cases and the observation group of 21 cases. The control group was treated with routine postoperative treatment, and the observation group was treated with recombinant human brain natriuretic peptide on the basic treatment of control group, then the myocardial enzymes, serum cardiac function indexes and oxygen metabolism indexes of the two groups before the surgery and at 2 h, 12 h and 24 h after the surgery were respectively detected and compared.Results: There were no significant difference in myocardial enzymes, serum cardiac function indexes and oxygen metabolism indexes between two groups before the surgery (allP>0.05), while the myocardial enzymes and serum cardiac function indexes of the observation group at 2 h ,12 h and 24 h after the surgery were all significantly lower than those of control group, the oxygen metabolism indexes were significantly better than the levels of control group (allP<0.05).Conclusions:The recombinant human brain natriuretic peptide can effectively improve the myocardial enzymes, serum cardiac function indexes and oxygen metabolism state of patients with open heart surgery with cardiopulmonary bypass, and it has application value for the patients with the surgery is higher.

  13. A thiourea-functionalized metal-organic macrocycle for the catalysis of Michael additions and prominent size-selective effect.

    Science.gov (United States)

    Yang, Lu; Zhao, Liang; Zhou, Zhen; He, Cheng; Sun, Hui; Duan, Chunying

    2017-03-21

    A discrete tetranuclear thiourea-based metal-organic macrocycle (MOM) with a large size was constructed by a well-designed organic ligand and nickel(ii) ions via self-assembly. Incorporating thiourea groups as hydrogen-bond donors into a metal-organic complex system leads to a new approach for synthesizing functionalized heterogeneous catalysts, as this not only introduces coordination sites serving as chelators, but also overcomes the issues of self-association via intermolecular H-bonding, often occurring in homogeneous systems. The packing structure of this material formed a confined environment suitable for the access of substrate molecules dragged by the strong hydrogen-bond interactions from the thiourea groups, thus achieving a high catalytic performance in Michael additions of nitrostyrenes to nitroalkanes, with remarkable yields and size-selectivity in heterogeneous phase. Moreover, a comparison of the IR spectrum of Ni-SPT with the spectra of dimethyl malonate- and β-nitrostyrene-impregnated Ni-SPT indicated that both substrate molecules, β-nitrostyrene and dimethyl malonate, were able to access the cavity of the trimeric subunit.

  14. Functional mammalian spliceosomal complex E contains SMN complex proteins in addition to U1 and U2 snRNPs.

    Science.gov (United States)

    Makarov, Evgeny M; Owen, Nicholas; Bottrill, Andrew; Makarova, Olga V

    2012-03-01

    Spliceosomes remove introns from primary gene transcripts. They assemble de novo on each intron through a series of steps that involve the incorporation of five snRNP particles and multiple non-snRNP proteins. In mammals, all the intermediate complexes have been characterized on one transcript (MINX), with the exception of the very first, complex E. We have purified this complex by two independent procedures using antibodies to either U1-A or PRPF40A proteins, which are known to associate at an early stage of assembly. We demonstrate that the purified complexes are functional in splicing using commitment assays. These complexes contain components expected to be in the E complex and a number of previously unrecognized factors, including survival of motor neurons (SMN) and proteins of the SMN-associated complex. Depletion of the SMN complex proteins from nuclear extracts inhibits formation of the E complex and causes non-productive complexes to accumulate. This suggests that the SMN complex stabilizes the association of U1 and U2 snRNPs with pre-mRNA. In addition, the antibody to PRPF40A precipitated U2 snRNPs from nuclear extracts, indicating that PRPF40A associates with U2 snRNPs.

  15. Interfacial oxygen and nitrogen induced dipole formation and vacancy passivation for increased effective work functions in TiN/HfO[sub 2] gate stacks

    KAUST Repository

    Hinkle, C. L.

    2010-03-09

    Effective work function (EWF) changes of TiN/HfO2annealed at low temperatures in different ambient environments are correlated with the atomic concentration of oxygen in the TiN near the metal/dielectric interface. EWF increases of 550 meV are achieved with anneals that incorporate oxygen throughout the TiN with [O]=2.8×1021 cm−3 near the TiN/HfO2interface. However, further increasing the oxygen concentration via more aggressive anneals results in a relative decrease of the EWF and increase in electrical thickness. First-principles calculations indicate the exchange of O and N atoms near the TiN/HfO2interface cause the formation of dipoles that increase the EWF.

  16. Oxygen cycling in conjunction with stem cell transplantation induces NOS3 expression leading to attenuation of fibrosis and improved cardiac function

    Science.gov (United States)

    Khan, Mahmood; Meduru, Sarath; Gogna, Rajan; Madan, Esha; Citro, Lucas; Kuppusamy, Muthulakshmi L.; Sayyid, Muzzammil; Mostafa, Mahmoud; Hamlin, Robert L.; Kuppusamy, Periannan

    2012-01-01

    Aims Myocardial infarction (MI) is associated with irreversible loss of viable cardiomyocytes. Cell therapy is a potential option to replace the lost cardiomyocytes and restore cardiac function. However, cell therapy is faced with a number of challenges, including survival of the transplanted cells in the infarct region, which is characterized by abundant levels of oxidants and lack of a pro-survival support mechanism. The goal of the present study was to evaluate the effect of supplemental oxygenation on cell engraftment and functional recovery in a rat model. Methods and results MI was induced in rats by a 60-min occlusion of the coronary artery, followed by restoration of flow. Mesenchymal stem cells (MSCs), isolated from adult rat bone marrow, were transplanted in the MI region. Rats with transplanted MSCs were exposed to hyperbaric oxygen (HBO: 100% O2, 2 atmospheres absolute) for 90 min, 5 days/week for 4 weeks. The experimental groups were: MI (control), Ox (MI + HBO), MSC (MI + MSC), and MSC + Ox (MI + MSC + HBO). HBO exposure (oxygenation) was started 3 days after induction of MI. MSCs were transplanted 1 week after induction of MI. Echocardiography showed a significant recovery of cardiac function in the MSC + Ox group, when compared with the MI or MSC group. Oxygenation increased the engraftment of MSCs and vascular density in the infarct region. Molecular analysis of infarct tissue showed a four-fold increase in NOS3 expression in the MSC + Ox group compared with the MI group. Conclusions The results showed that post-MI exposure of rats to daily cycles of hyperoxygenation (oxygen cycling) improved stem cell engraftment, cardiac function, and increased NOS3 expression. PMID:22012955

  17. Imaging oxygen metabolism with hyperpolarized magnetic resonance: a novel approach for the examination of cardiac and renal function.

    Science.gov (United States)

    Schroeder, Marie; Laustsen, Christoffer

    2017-02-28

    Every tissue in the body critically depends on meeting its energetic demands with sufficient oxygen supply. Oxygen supply/demand imbalances underlie the diseases that inflict the greatest socio-economic burden globally. The purpose of this review is to examine how hyperpolarized contrast media, used in combination with MR data acquisition methods, may advance our ability to assess oxygen metabolism non-invasively and thus improve management of clinical disease. We first introduce the concept of hyperpolarization and how hyperpolarized contrast media have been practically implemented to achieve translational and clinical research. We will then analyse how incorporating hyperpolarized contrast media could enable realization of unmet technical needs in clinical practice. We will focus on imaging cardiac and renal oxygen metabolism, as both organs have unique physiological demands to satisfy their requirements for tissue oxygenation, their dysfunction plays a fundamental role in society's most prevalent diseases, and each organ presents unique imaging challenges. It is our aim that this review attracts a multi-disciplinary audience and sparks collaborations that utilize an exciting, emergent technology to advance our ability to treat patients adversely affected by an oxygen supply/demand mismatch. © 2017 The Author(s).

  18. The Conjugate Addition- Elimination Reaction of Morita-Baylis-Hillman C- Adducts: A Density Functional Theory Study

    KAUST Repository

    Tan, Davin

    2011-12-01

    The Morita-Baylis-Hillman (MBH) reaction is a very versatile synthetic protocol to synthesize various useful compounds containing several functional groups. MBH acetates and carbonates are highly valued compounds as they have good potential to be precursors for organic synthesis reactions due to their ease of modification and synthesis. This thesis utilizes Density Functional Theory (DFT) calculations to understand the mechanism and selectivity of an unexpected tandem conjugate addition-elimination (CA-E) reaction of allylic alkylated Morita-Baylis-Hillman C- adducts. This synthetic protocol was developed by Prof. Zhi-Yong Jiang and co-workers from Henan University, China. The reaction required the use of sub-stoichiometric amounts of an organic or inorganic Brøndst base as a catalyst and was achieved with excellent yields (96%) in neat conditions. TBD gave the highest yield amongst the organocatalysts and Cs2CO3 gave the highest yield amongst all screened bases. A possible mechanistic pathway was proposed and three different energy profiles were modeled using 1,5,7-triaza-bicyclo-[4.4.0]-dec-5-ene (TBD), Cs2CO3 and CO32- as catalysts. All three models were able to explain the experimental observations, revealing both kinetic and thermodynamic factors influencing the selectivity of the CA-E reaction. CO32- model gave the most promising result, revealing a significant energy difference of 17.9 kcal/mol between the transition states of the two differing pathways and an energy difference of 20.9 kcal/mol between the two possible products. Although TBD modeling did not show significant difference in the transition states of the differing pathways, it revealed an unexpected secondary non-covalent electrostatic interaction, involving the electron deficient C atom of the triaza CN3 moiety of the TBD catalyst and the O atom of a neighboring NO2- group in the intermediate. Subsequent modeling using a similar substrate proved the possibility of this non

  19. Changes in brain function and anatomical structure following treatment of hyperbaric oxygen for visual pathway abnormalities In 16 cases Evaluation of functional magnetic resonance Imaging combined with diffusion tensor imaging

    Institute of Scientific and Technical Information of China (English)

    Ziqian Chen; Ping Ni; Hui Xiao; Jinhua Chen; Gennian Qian; Youqiang Ye; Shangwen Xu; Jinliang Wang; Xizhang Yang

    2008-01-01

    BACKGROUND:There is a growing research focus on the combination of blood oxygenation level dependent functional magnetic resonance imaging(BOLD-fMRI)and diffusion tensor imaging(DTI)to evaluate visual cortical function and structural changes in the cerebrum,as well as morphological changes to the white matter fiber tracks,after visual pathway lesions.However,the combined application of BOLD-fMRI and DTI in treating of visual pathway abnormalities still requires further studies. OBJECTIVE:To observe and evaluate the effects of hyperbaric oxygen on visual pathway abnormalities,and to evaluate the characteristics of cerebral function and anatomic structural changes by using BOLD-fMRI combined with DTI technique. DESIGN:Case contrast observation. SETTING:Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA.PARTICIPANTS:Sixteen patients(9 males and 7 females,15-77 years old)with lateral or bilateral visual disorder induced by visual pathway lesions were selected from the Department of Neurology,Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA from January 2006 to May 2007.These patients comprised the lesion group.Measures of interventional therapy:hyperbaric oxygen of two normal atmospheres for three courses(10 d/course)and routine internal medicine treatment.In addition,12 healthy subjects of similar sex and age to the lesion group were regarded as the control group.The control group underwent routine ophthalmological and ocular fundus examinations; diagnostic results were normal. The experiment received confirmed consent from the local ethic committee,and all patients provided informed consent.METHODS:BOLD-fMRI and DTI manifestations in the lesion group were observed before and after hyperbaric oxygen intervention,and the results were compared with the control group.The subjects were positioned on their back,and BOLD-fMRI images were collected with the following GRE EPI sequence:TR= 2 000 ms,TE=40 ms,layer thickness=5 mm

  20. Assessing the effects of a short-term green tea intervention in skin microvascular function and oxygen tension in older and younger adults.

    Science.gov (United States)

    Wasilewski, Rebecca; Ubara, Emmanuel O; Klonizakis, Markos

    2016-09-01

    Green tea consumption has been associated with a reduction in cardiovascular disease risk factors. However, there is little evidence examining its potential differing effect between younger and older populations, whilst little is known on its effect on the circulatory system when oxygen demand is higher. Therefore the aim of this study was to evaluate the short-term effects of green tea consumption on microvascular functioning in both an older and younger population. Fifteen young [24 (4.0)] and fifteen older [61 (4.0)] participants, consumed two cups of green tea daily for 14days. We used Laser Doppler Flowmetry (LDF) to assess cutaneous microvascular function and Transcutaneous Oxygen monitoring (TcPO2) to assess skin oxygen tension. Systolic and diastolic blood pressure were also assessed on both visits. We observed significant improvements in axon-mediated microvascular vasodilation for the younger group [1.6 (0.59) vs 2.05 (0.72), p<0.05] and the older group [1.25 (0.58) vs 1.65 (0.5) p<0.05]. Improvements in skin oxygen tension were also noted for both groups in both noted TcPO2 measures (i.e. 1.25 (0.58) vs 1.65 (0.5) (p<0.05), for ΔTcPO2max for the older group, between visits) respectively. Improvements were also observed for systolic blood pressure in both the younger [120 (10) vs 112 (10), p<0.05] and older group [129 (12) v 124 (11), p<0.001]. In conclusion, we observed statistically-significant improvements in microvascular function and skin oxygen tension. Our results suggest that green tea may prove beneficial as a dietary element in lifestyle interventions aiming to lower cardiovascular disease risk, in both older and younger populations.

  1. Indigenous perception and characterization of Yanyanku and Ikpiru: two functional additives for the fermentation of African locust bean.

    Science.gov (United States)

    Agbobatinkpo, Pélagie B; Azokpota, Paulin; Akissoe, Noël; Kayodé, Polycarpe; Da Gbadji, Rachelle; Hounhouigan, D Joseph

    2011-01-01

    Indigenous perception, processing methods, and physicochemical and microbiological characteristics of Yanyanku and Ikpiru, two additives used to produce fermented African locust bean condiments, Sonru and Iru, were evaluated. According to producers, these additives accelerate the fermentation and soften the texture of the condiments. Yanyanku is produced by spontaneous fermentation with either Hibiscus sabdariffa or Gossypium hirsutum or Adansonia digitata seeds, whereas only Hibiscus sabdariffa seeds are used for Ikpiru. Both additives, with pH values ranging between 6.2 and 10 and Bacillus spores varying between 5.5 and 8.9 Log(10) (CFU/g), could be considered as softening additives or enrichment inocula to produce condiments.

  2. Copper concentration of vineyard soils as a function of pH variation and addition of poultry litter

    Directory of Open Access Journals (Sweden)

    Gilmar Ribeiro Nachtigall

    2007-11-01

    Full Text Available Copper (Cu concentration was evaluated as a function of pH variation and addition of poultry litter to a Dystrophic Lithic Udorthent and a Humic Dystrudept from the state of Rio Grande do Sul, Brazil, cultivated with vines treated with successive applications of Cu-based product. Samples were collected from the surface layer (0 to 10 cm. Soluble Cu concentration was determined using DTPA and Mehlich III as extractants, and exchangeable Cu was determined in CaCl2. The availability of Cu was mainly affected by the soil pH. CaCl2 extractant had the best correlation with Cu concentration in contaminated soils, according to treatments applied. The addition of poultry litter did not reduce Cu availability in these soils. Total soil Cu content varied between 1,300 and 1,400 mg kg-1 in both soils. Copper available fractions, extracted by DTPA, CaCl2 and Mehlich III, averaged 35, 0.2 and 63%, respectively, of the total Cu present in the soil.Avaliaram-se os teores de Cu em função da variação do pH e da adição de cama-de-frango de dois solos com elevados teores deste elemento. Foram coletadas amostras da camada superficial (0 a 10 cm de um typical dystrophic Lithic Udorthent - LU (Neossolo Litólico distrófico típico e de um Humic Dystrudept - HD (Cambissolo Húmico alumínico típico da região da Serra do RS, cultivados com parreirais que receberam aplicações sucessivas de produtos à base de Cu. Foram determinados os teores de Cu solúvel em DTPA e pelo método Mehlich III, além do Cu trocável em CaCl2. A disponibilidade de Cu foi afetada principalmente pelo pH do solo. O extrator CaCl2 foi o que melhor se correlacionou com os teores de Cu em solos contaminados em função dos tratamentos aplicados. A adição de cama-de-frango não diminuiu a disponibilidade de Cu destes solos. Os teores de Cu total variaram entre 1.300 e 1.400 mg kg-1 nos dois solos. Considerando os teores totais de Cu nos solos, as frações "disponíveis", extra

  3. Quadratic function between arterial partial oxygen pressure and mortality risk in sepsis patients: an interaction with simplified acute physiology score

    OpenAIRE

    Zhongheng Zhang; Xuqing Ji

    2016-01-01

    Oxygen therapy is widely used in emergency and critical care settings, while there is little evidence on its real therapeutic effect. The study aimed to explore the impact of arterial oxygen partial pressure (PaO2) on clinical outcomes in patients with sepsis. A large clinical database was employed for the study. Subjects meeting the diagnostic criteria of sepsis were eligible for the study. All measurements of PaO2 were extracted. The primary endpoint was death from any causes during hospita...

  4. Symposium on Oxygen Binding Heme Proteins Structure, Dynamics, Function and Genetics Held in Pacific Grove, California on 9-13 October 1988

    Science.gov (United States)

    1989-08-15

    powerful in understanding its structure and function relationship. LII - 2 I MECANISMS OF MOLECULAR RECOGNITION IN HEME PROTEINS I Stephen G. Sligar... transcript specific for vgb was detected after Northern hybridization. The relative amount of this mANA increased in cells grown at low levels of oxygen...proving that at this phylogenetic level the blood cells are U transcriptionally active. This task was accomplished by first performing partial N-terminal

  5. Solubilization of lignite and behavior of oxygen containing functional groups in coal with superacid; Chokyosan wo mochiita kattan no kayoka oyobi sanso kannoki no kyodo

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, K.; Saito, I. [National Institute for Resources and Environment, Tsukuba (Japan); Sasaki, S.; Suganuma, A. [Science University of Tokyo, Tokyo (Japan). Faculty of Science and Technology

    1996-10-28

    Solubilization of lignite including a large amount of oxygen containing functional groups was attempted using HF/BF3, and the behavior of oxygen containing functional group, one of the important factors for coal liquefaction, was studied. In experiment, the cooled slurry of Yallourn coal specimen and solvent (toluene, isopentane) was filled into a vacuum autoclave together with HF/BF3. Reaction was performed under spontaneous pressure at 50, 100 or 150{degree}C for 3 hours. The distribution of oxygen containing functional groups in each coal specimen was determined by quantification of carboxyl group, hydroxyl group and carbonyl group. As the experimental result, the superacid mixture of HF and BF3 considerably improved the solubility of coal specimens into solvent as compared with individual HF and BF3. The solubility was 68wt% into benzene, 96% into THF and 99% (nearly 100%) into pyridine. It was suggested that production of Broensted acid with strong acidity causes strong catalysis. 6 refs., 2 figs., 1 tab.

  6. Oxygen permeable membrane for oxygen enriched combustion

    Energy Technology Data Exchange (ETDEWEB)

    Asakawa, S. (Matsushita Research Inst., Tokyo, Japan); Saito, Y.; Kawahito, M.; Ito, Y.; Tsuchiya, S.; Sugata, K.

    1983-02-01

    An oxygen enriched air production system using gas separation membranes has been developed to be used for fuel combustion systems. High oxygen permeable scopolymers, including three dimensional structure, have been synthesized through condensation of polyvinylphenol with some, ..cap alpha..,..omega..-bis (diethylamino) polydimethylsiloxanes. The experimental results showed that the oxygen permeability through the copolymer varies as a function of the dimethylsiloxane content of the copolymers. Such composition dependence of the oxygen permeability was explained on the basis of polymer constitution. Typical values of the oxygen permeability, 3.4 x 10/sup -8/ (cc x cm/cm/sup 2/ x sec x cmHg) and ..cap alpha.., 2.1, were obtained at 72% of dimethylsiloxane content. The copolymers are soluble in most common organic solvents and uniform, defect-free membranes as thin as 1000 Angstroms have been formed by spreading solutions of the copolymer on water. Composite membranes fabricated by applying the membranes to porous support materials were used for practical gas separation and 30% oxygen enriched air was produced from ambient air. A new type oxygen enriched combustion system, which is more efficient for energy saving, has been developed by utilizing oxygen enriched air thus produced. 15 references, 15 figures, 1 table.

  7. Using oxygen at home

    Science.gov (United States)

    Oxygen - home use; COPD - home oxygen; Chronic obstructive airways disease - home oxygen; Chronic obstructive lung disease - home oxygen; Chronic bronchitis - home oxygen; Emphysema - home oxygen; Chronic respiratory ...

  8. Joint Functions of Protein Residues and NADP(H) in Oxygen Activation by Flavin-containing Monooxygenase

    NARCIS (Netherlands)

    Orru, Roberto; Torres Pazmino, Daniel; Fraaije, Marco W.; Mattevi, Andrea

    2010-01-01

    The reactivity of flavoenzymes with dioxygen is at the heart of a number of biochemical reactions with far reaching implications for cell physiology and pathology. Flavin-containing monooxygenases are an attractive model system to study flavin-mediated oxygenation. In these enzymes, the NADP(H)

  9. Generalization of Rosenfeld's functional to non-additive hard-spheres: pair structure and test-particle consistency

    Energy Technology Data Exchange (ETDEWEB)

    Ayadim, A; Amokrane, S [Physique des Liquides et Milieux Complexes, Faculte des Sciences et Technologie, Universite Paris-Est (Creteil), 61 Avenue du General de Gaulle, 94010 Creteil Cedex (France)

    2010-01-27

    The accuracy of the structural data obtained from the recently proposed generalization to non-additive hard-spheres (Schmidt 2004 J. Phys.: Condens. Matter 16 L351) of Rosenfeld's functional is investigated. The radial distribution functions computed from the direct correlation functions generated by the functional, through the Ornstein-Zernike equations, are compared with those obtained from the density profile equations in the test-particle limit, without and with test-particle consistency. The differences between these routes and the role of the optimization of the parameters of the reference system when the functional is used to obtain the reference bridge functional are discussed in the case of symmetric binary mixtures of non-additive hard-spheres. The case of highly asymmetric mixtures is finally briefly discussed.

  10. Blood oxygenation-level dependent functional MRI in evaluating the selective activation of motor cortexes associated with recovery of motor function in hemiplegic patients with ischemic stroke

    Institute of Scientific and Technical Information of China (English)

    Yuechun Li; Xiaoyan Liu; Guorong Liu; Ying He; Baojun Wang; Furu Liang; Li Wang; Hui Zhang; Jingfen Zhang; Ruiming Li

    2006-01-01

    BACKGROUND: Previous studies about blood oxygenation-level dependent (BOLD) functional MRI (fMRI) have indicated that the poststroke recovery of motor function is accompanied by the selective activation of motor cor texes with high correlation.OBJECTIVE: To evaluate the short-term outcomes after rehabilitative interventions with BOLD fMRI in hemi plegic patients with acute stroke, and analyze the correlation of the excitement of brain function in the passive and active movements of the affected limb with the recovery of motor function. DESIGN : A case observation. SETTING: Department of Neurology, Baotou Central Hospital. PARTICIPANTS: Thirty hemiplegic inpatients with ischemic stroke were selected from the Department of Neurology, Baotou Central Hospital from January to December in 2005, including 16 males and 14 females, aging 44-71 years with an average age of (56±5) years, and the disease course ranged from 12 to 72 hours. Inclusive criteria: In accordance with the diagnostic standard of ischemic stroke revised by the Fourth National Academic Meeting for Cerebrovascular Disease; Confirmed by cranial CT or MRI. They were all informed agreed with the detected items.METHODS: ① The Bobath technique was adopted in the rehabilitative interventions of the 30 patients, 30 minutes for each time, twice a day for three weeks continuously. ② The hand motor recovery of the stroke patients was graded by the Brunnstrom,stages ( Ⅰ -Ⅵ), and be able to grasp various objects and extend for the whole range was taken as grade Ⅵ. ③ The patients were examined with fMRI BOLD before rehabilitation and 3 weeks after rehabilitation. All the patients were trained with finger movements, the distracting thoughts should be eliminated as much as possible especially during the movement phase, the patients should highly concentrate on the hand movements. The range for the finger movements should be as large as possible with moderate frequency. The hand movements should be 10 s with

  11. The first peripherally masked thiol dendrimers: a facile and highly efficient functionalization strategy of polyester dendrimers via one-pot xanthate deprotection/thiol-acrylate Michael addition reactions.

    Science.gov (United States)

    Auty, Sam E R; Andrén, Oliver; Malkoch, Michael; Rannard, Steven P

    2014-06-25

    Introducing multiple reactive functional groups at the periphery of dendrimer materials presents considerable challenges if the functionality is able to self-react. An efficient and facile approach to introducing masked thiols at the surface of polyester dendrimers is presented. One-pot, deprotection/thiol-acrylate Michael addition from the xanthate-functional dendritic substrates (generation zero to two) has been achieved for the first time, with high efficiency demonstrated using three acrylates of varying chemistry and avoiding disulfide formation.

  12. Ambient oxygen promotes tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Ho Joong Sung

    Full Text Available Oxygen serves as an essential factor for oxidative stress, and it has been shown to be a mutagen in bacteria. While it is well established that ambient oxygen can also cause genomic instability in cultured mammalian cells, its effect on de novo tumorigenesis at the organismal level is unclear. Herein, by decreasing ambient oxygen exposure, we report a ∼50% increase in the median tumor-free survival time of p53-/- mice. In the thymus, reducing oxygen exposure decreased the levels of oxidative DNA damage and RAG recombinase, both of which are known to promote lymphomagenesis in p53-/- mice. Oxygen is further shown to be associated with genomic instability in two additional cancer models involving the APC tumor suppressor gene and chemical carcinogenesis. Together, these observations represent the first report directly testing the effect of ambient oxygen on de novo tumorigenesis and provide important physiologic evidence demonstrating its critical role in increasing genomic instability in vivo.

  13. Evaluation of a functional soy product with addition of soy fiber and fermented with probiotic kefir culture

    Directory of Open Access Journals (Sweden)

    Tahis Regina Baú

    2014-06-01

    Full Text Available The objective of this study was to evaluate the chemical, sensory properties and stability of a functional soy product with soy fiber and fermented with probiotic kefir culture. The product was characterized by the chemical composition, color and sensory analysis. The stability of the product was evaluated by pH, acidity, viscosity, firmness, syneresis measurements and cells counts. The functional soy product presented better chemical composition and difference in color compared to the fermented product without fiber. Sensory analysis showed that the functional soy product had good acceptance and had better firmness and reduced syneresis compared to fermented product without fiber. The lactic acid bacteria counts decreased slightly during 28 days at 4°C of the storage and the product showed good microbiological stability. The functional soy product due to high Lactococcus lactis counts could be considered as a probiotic for the entire storage period.

  14. Effect of functionalized metal oxides addition on the mechanical, thermal and swelling behaviour of polyester/jute composites

    Directory of Open Access Journals (Sweden)

    Jaideep Adhikari

    2017-04-01

    Full Text Available The unsaturated polyester composites were fabricated in hand lay-up method by reinforcing with jute fibre along with alumina or zirconia particles in different filler loading viz. 5, 10, 15 and 20 wt%. It was observed that with incorporation of fillers, the microhardness value of the resulting composites increases and reaches its maximum at 20 wt% filler content. Characterizations were performed on the composites fabricated with overall 20 wt% filler content (18 wt% fibre and 2 wt% metal oxide particles. Various characterizations like Vicker’s microhardness testing, scanning electron microscopy (SEM, Energy-dispersive X-ray spectroscopy (EDS, X-ray Diffraction (XRD, Fourier transform infrared (FTIR spectroscopy, thermogravimetric (TG analysis, differential scanning calorimetry (DSC, limiting oxygen index (LOI testing and water absorption test were performed. Tensile, Flexural testing were also performed on the normal and water absorbed samples. SEM analysis ensured good dispersion of filler within the polymer matrix. EDS and XRD were performed to identify the filler in the composites. FITR spectroscopy revealed the bonding of fillers with the matrix. TG analysis showed that thermal stability, degradation temperature of jute-ZrO2 composites were best over the others. LOI testing also shows similar trend, showing better fire resistant property of jute-ZrO2 composites than the Al2O3 dispersed. Water absorption test indicates the stability of different composite in various atmospheres (normal, boiling, simulated marine, alkali and acid water.

  15. Instrumented Indentation of Lung Reveals Significant Short Term Alteration in Mechanical Behavior with 100% Oxygen

    Directory of Open Access Journals (Sweden)

    Maricris R. Silva

    2010-01-01

    Full Text Available In critical care, trauma, or other situations involving reduced lung function, oxygen is given to avoid hypoxia. It is known that under certain conditions and long time (several hours exposure, oxygen is toxic to the lungs, the possible mechanisms being direct cellular damage or surfactant dysfunction. Our key objective was to investigate possible changes in lung function when exposed to 100% oxygen in the short term (several tidal volumes. We performed mechanical tests on lobar surfaces of excised mammalian lungs inflated with air or 100% oxygen, examining (i stiffness, (ii non-linear mechanical response and (iii induced alveolar deformation. Our results showed that within five tidal volumes of breathing 100% oxygen, lung mechanics are significantly altered. In addition, after five tidal volumes of laboratory air, lung mechanical behavior begins to return to pre-oxygen levels, indicating some reversibility. These significant and short-term mechanical effects of oxygen could be linked to oxygen toxicity.

  16. Improvement in antioxidant functionality and shelf life of yukwa (fried rice snack) by turmeric (Curcuma longa L.) powder addition.

    Science.gov (United States)

    Lim, Seung-Taik; Han, Jung-Ah

    2016-05-15

    The physico-chemical, oxidative and sensory characteristics of fried rice snack, yukwa with different amounts of turmeric powder (Curcuma longa) were investigated. The moisture content of the pallet ranged from 16.47% to 19.84%. After frying the pallet, a slight decrease in the degree of expansion was obtained with increasing turmeric powder content. The textural properties of yukwa were not changed until the turmeric powder content reached 5%; however, over 8% addition induced a decrease in the hardness and an increase in the crispiness. Oxidative deterioration was effectively inhibited by turmeric powder addition, and more turmeric powder in yukwa led to higher free radical scavenging activity. Based on the sensory characteristics, a 5% addition of turmeric powder was the most acceptable for the yukwa product. In the correlation results among variables, the moisture content of the pallet proved to be the most important factor for yukwa quality.

  17. 新型氧化添加剂EGM影响柴油机性能和排放特性的研究%A New Oxygenating Additive EGM and Its Effects on the Performances and Emissions of Diesel Engine

    Institute of Scientific and Technical Information of China (English)

    刘永启; 王延遐

    2007-01-01

    A kind of oxygenate additive, EGM, has been proposed and tested for use with diesel fuel as a means of reducing exhaust emissions. The effects of EGM on the power, fuel economy and emission characteristics are studied on a DI diesel engine 4JB1. An ultrasonic mixer is used to blend various EGM and diesel fuels in real-time as they flow to the engine. The results show that smoke and CO emissions decrease significantly with increase in the fraction of EGM in the blends at high loads. The blends have little effects on the NOx emissions. HC emissions are higher than that of diesel fuel at loads.%提出了用含氧柴油添加剂EGM降低柴油机碳烟排放的方法,建立了超声波EGM-柴油在线混合装置,在4JB1直喷柴油机上试验研究了含氧添加剂对发动机性能和排放特性的影响.结果表明,在大负荷时随着混合燃料中的EGM增加,碳烟和CO的排放显著降低;对NOx的排放影响很小;在小负荷时HC的排放增加.

  18. Effect of sequential mechanical ventilation therapy on alveolar oxygenation function and systemic inflammatory response syndrome in patients with severe pneumonia and respiratory failure

    Institute of Scientific and Technical Information of China (English)

    Rong Hu

    2016-01-01

    Objective:To study the effect of sequential mechanical ventilation therapy on alveolar oxygenation function and systemic inflammatory response syndrome in patients with severe pneumonia and respiratory failure.Methods:A total of 92 patients who were diagnosed with severe pneumonia and required mechanical ventilation therapy in our hospital from May 2012 to October 2015 were selected and randomly divided into two groups, sequential group received invasive-non-invasive sequential mechanical ventilation therapy and routine group received conventional invasive mechanical ventilation therapy. Three days after treatment, blood gas analysis parameters, mechanical ventilation parameters, the levels of inflammatory cytokines, cardiac function injury molecules, kidney damage molecules in serum and the levels of kidney damage molecules in the urine were compared between two groups of patients. Results:Three day after treatment, PaO2, HCO3-, TI, TE and TPTEF of sequential group were significantly higher than those of routine group; serum IL-6, TNF-α, sTREM-1, IL-4, IL-10, IL-13, ANP, BNP, NPY, cTnI, CYS, NGAL and KIM-1 levels of sequential group were significantly lower than those of routine group, and urine NGAL, KIM-1 and Netrin-1 levels were significantly lower than those of routine group.Conclusions: Invasive-non-invasive sequential mechanical ventilation therapy can improve the alveolar oxygenation function and reduce the systemic inflammatory response as well as cardiac function and renal function injury in patients with severe pneumonia and respiratory failure.

  19. Density functional study on the heterogeneous oxidation of NO over α-Fe2O3 catalyst by H2O2: Effect of oxygen vacancy

    Science.gov (United States)

    Song, Zijian; Wang, Ben; Yu, Jie; Ma, Chuan; Zhou, Changsong; Chen, Tao; Yan, Qianqian; Wang, Ke; Sun, Lushi

    2017-08-01

    Catalytic oxidation with H2O2 is a promising method for NOx emission control in coal-fired power plants. Hematite-based catalysts are attracting increased attention because of their surface redox reactivity. To elucidate the NO oxidation mechanism on α-Fe2O3 surfaces, density functional theory (DFT) calculations were conducted by investigating the adsorption characteristics of nitric oxide (NO) and hydrogen peroxide (H2O2) on perfect and oxygen defect α-Fe2O3 (0 0 1) surfaces. Results show that NO was molecularly adsorbed on two kinds of surfaces. H2O2 adsorption on perfect surface was also in a molecular form; however, H2O2 dissociation occurred on oxygen defect α-Fe2O3 (0 0 1) surface. The adsorption intensities of the two gas molecules in perfect α-Fe2O3 (0 0 1) surface followed the order NO > H2O2, and the opposite was true for the oxygen defect α-Fe2O3 (0 0 1). Oxygen vacancy remarkably enhanced the adsorption intensities of NO and H2O2 and promoted H2O2 decomposition on catalyst surface. As an oxidative product of NO, HNO2 was synthesized when NO and H2O2 co-adsorbed on the oxygen defect α-Fe2O3 (0 0 1) surface. Analyses of Mulliken population, electron density difference, and partial density of states showed that H2O2 decomposition followed the Haber-Weiss mechanism. The trends of equilibrium constants suggested that NO adsorption on α-Fe2O3 (0 0 1) surface was more favorable at low than at high temperatures, whereas H2O2 adsorption was favorable between 375 and 450 K. These calculations results well agreed with the experimental ones and further elucidates the reaction mechanisms.

  20. Structural and functional study of the nematode community from the Indian western continental margin with reference to habitat heterogeneity and oxygen minimum zone

    Directory of Open Access Journals (Sweden)

    R. Singh

    2015-07-01

    Full Text Available We studied patterns of nematode distribution along the western Indian continental margin to determine the influence of habitat heterogeneity and oxygen minimum on the community's taxonomic and functional structure. A single transect, perpendicular to the coast at 14° N latitude was sampled from 34 to 2546 m depth for biological and environmental variables during August 2007. Nematodes were identified to species and classified according to biological/functional traits. A total of 110 nematode species belonging to 24 families were found along the transect. Mean nematode density was higher on the shelf (176 ind 10 cm−2, 34 m depth than on the slope (124 ind 10 cm−2 or in the basin 62.9 ind 10 cm−2. Across the entire study area, the dominant species were Terschellingia longicaudata, (15.2 %, Desmodora sp 1, Sphaerolaimus gracilis, and Theristus ensifer; their maximum density was at shelf stations. Multidimensional scaling ordination (nMDS of the nematode species abundance data indicated the effect of different zones (ANOSIM; Global R = 0.607; P = 0.028, but it was not the same in case of functional traits. Only seven species were found exclusively in the oxygen minimum zone: Pselionema sp 1, Choanolaimus sp 2, Halichoanolaimus sp 1, Cobbia dentata, Daptonema sp 1, Trissonchulus sp 1, and Minolaimus sp 1. Moreover, in our study, species diversity was higher on the shelf than on the slope or in the basin. The distinctive features of all three zones as based on nematofaunal abundance were also reflected in the functional traits (feeding types, body shape, tail shape, and life history strategy. Correlation with a number of environmental variables indicated that food quality (measured as the organic carbon content and chlorophyll content and oxygen level were the major factors that influenced the nematode community (structural and functional.

  1. Choosing Membership Function for Method of Localization of Additional Reactive Power Sources in a Power Grid Using Fuzzy Logic

    Directory of Open Access Journals (Sweden)

    Artur Zbroński

    2013-12-01

    Full Text Available This paper introduces choosing location for additional reactive power sources for a power grid. The fuzzy logic method for localization is described, with special attention focused on choosing the proper fuzzification method, used for reasoning. Results of using such a method are presented for an example power network.

  2. Microstructure, characterizations, functionality and compressive strength of cement-based materials using zinc oxide nanoparticles as an additive

    Energy Technology Data Exchange (ETDEWEB)

    Nochaiya, Thanongsak [Department of Physics, Faculty of Science, Naresuan University, Phitsanulok 65000 (Thailand); Sekine, Yoshika [Department of Chemistry, School of Science, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Choopun, Supab [Applied Physics Research Laboratory, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Chaipanich, Arnon, E-mail: arnon.chaipanich@cmu.ac.th [Advanced Cement-Based Materials Research Unit, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2015-05-05

    Highlights: • Nano zinc oxide was used as an additive material. • Microstructure and phase characterization of pastes were characterized using SEM and XRD. • TGA and FTIR were also used to determine the hydration reaction. • Compressive strength of ZnO mixes was found to increase at 28 days. - Abstract: Zinc oxide nanoparticles as a nanophotocatalyst has great potential for self-cleaning applications in concrete structures, its effects on the cement hydration, setting time and compressive strength are also important when using it in practice. This paper reports the effects of zinc oxide nanoparticles, as an additive material, on properties of cement-based materials. Setting time, compressive strength and porosity of mortars were investigated. Microstructure and morphology of pastes were characterized using scanning electron microscope and X-ray diffraction (XRD), respectively. Moreover, thermal gravimetric analysis (TGA) and Fourier-transform infrared spectrometer (FTIR) were also used to determine the hydration reaction. The results show that Portland cement paste with additional ZnO was found to slightly increase the water requirement while the setting time presented prolongation period than the control mix. However, compressive strength of ZnO mixes was found to be higher than that of PC mix up to 15% (at 28 days) via filler effect. Microstructure, XRD and TGA results of ZnO pastes show less hydration products before 28 days but similar at 28 days. In addition, FTIR results confirmed the retardation when ZnO was partially added in Portland cement pastes.

  3. Impact of Dissolved Oxygen during UV-Irradiation on the Chemical Composition and Function of CHO Cell Culture Media.

    Directory of Open Access Journals (Sweden)

    Sarah M Meunier

    Full Text Available Ultraviolet (UV irradiation is advantageous as a sterilization technique in the biopharmaceutical industry since it is capable of targeting non-enveloped viruses that are typically challenging to destroy, as well as smaller viruses that can be difficult to remove via conventional separation techniques. In this work, we investigated the influence of oxygen in the media during UV irradiation and characterized the effect on chemical composition using NMR and LC-MS, as well as the ability of the irradiated media to support cell culture. Chemically defined Chinese hamster ovary cell growth media was irradiated at high fluences in a continuous-flow UV reactor. UV-irradiation caused the depletion of pyridoxamine, pyridoxine, pyruvate, riboflavin, tryptophan, and tyrosine; and accumulation of acetate, formate, kynurenine, lumichrome, and sarcosine. Pyridoxamine was the only compound to undergo complete degradation within the fluences considered; complete depletion of pyridoxamine was observed at 200 mJ/cm2. Although in both oxygen- and nitrogen-saturated media, the cell culture performance was affected at fluences above 200 mJ/cm2, there was less of an impact on cell culture performance in the nitrogen-saturated media. Based on these results, minimization of oxygen in cell culture media prior to UV treatment is recommended to minimize the negative impact on sensitive media.

  4. Blue whales (Balaenoptera musculus) optimize foraging efficiency by balancing oxygen use and energy gain as a function of prey density.

    Science.gov (United States)

    Hazen, Elliott Lee; Friedlaender, Ari Seth; Goldbogen, Jeremy Arthur

    2015-10-01

    Terrestrial predators can modulate the energy used for prey capture to maximize efficiency, but diving animals face the conflicting metabolic demands of energy intake and the minimization of oxygen depletion during a breath hold. It is thought that diving predators optimize their foraging success when oxygen use and energy gain act as competing currencies, but this hypothesis has not been rigorously tested because it has been difficult to measure the quality of prey that is targeted by free-ranging animals. We used high-resolution multisensor digital tags attached to foraging blue whales (Balaenoptera musculus) with concurrent acoustic prey measurements to quantify foraging performance across depth and prey density gradients. We parameterized two competing physiological models to estimate energy gain and expenditure based on foraging decisions. Our analyses show that at low prey densities, blue whale feeding rates and energy intake were low to minimize oxygen use, but at higher prey densities feeding frequency increased to maximize energy intake. Contrary to previous paradigms, we demonstrate that blue whales are not indiscriminate grazers but instead switch foraging strategies in response to variation in prey density and depth to maximize energetic efficiency.

  5. The influence of oxygen on radiation-induced structural and functional changes in glyceraldehyde-3-phosphate dehydrogenase and lactate dehydrogenase

    Science.gov (United States)

    Rodacka, Aleksandra; Serafin, Eligiusz; Bubinski, Michal; Krokosz, Anita; Puchala, Mieczyslaw

    2012-07-01

    Proteins are major targets for oxidative damage due to their abundance in cells and high reactivity with free radicals. In the present study we examined the influence of oxygen on radiation-induced inactivation and structural changes of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and lactate dehydrogenase (LDH). We chose these two enzymes because they occur at high concentrations and participate in the most important processes in organisms; furthermore, they show considerable similarity in their structure. Protein solutions were irradiated with X-rays in doses ranging from 0.1 to 0.7 kGy, in air and N2O. The much higher radiation inactivation of GAPDH as compared to LDH is correlated with substantially greater structural changes in this protein, mainly involving the loss of free thiol groups (-SH). Of lesser importance in the differentiation of the radiosensitivity of the studied enzymes are tryptophan residues. Molecular oxygen, present during irradiation, increased to a significantly greater extent the inactivation and structural changes of GAPDH than that of LDH. The results suggest that the greater effect of oxygen on GAPDH is due to the higher efficiency of the superoxide radical, the higher amount of hydroperoxides generated, and the higher degree of unfolding of this protein.

  6. Determination of potential energy functions and calculation transport properties of oxygen and nitric oxide via the inversion of reduced viscosity collision integrals at zero pressure

    Energy Technology Data Exchange (ETDEWEB)

    Abbaspour, Mohsen [Department of Chemistry, Ferdowsi University, Mashhad, Khorasan-Razavi 91779 (Iran, Islamic Republic of)], E-mail: mabbaspoor@wali.um.ac.ir; Goharshadi, Elaheh K. [Department of Chemistry, Ferdowsi University, Mashhad, Khorasan-Razavi 91779 (Iran, Islamic Republic of); Emampour, Jalal S. [Department of Chemistry, Ferdowsi University, Mashhad, Khorasan-Razavi 91779 (Iran, Islamic Republic of)

    2006-08-01

    The potential energy functions of oxygen and nitric oxide have been determined via the inversion of reduced viscosity collision integrals at zero pressure and fitted to obtain the analytical potential forms. The potentials reproduce viscosity, self-diffusion coefficient, and second virial coefficient of oxygen and nitric oxide in excellent accordance with the experimental data over a wide range of temperature. We have also derived very accurate equations for viscosity, self-diffusion coefficient, and second virial coefficient of O{sub 2} and NO at different temperatures. Comparisons of O{sub 2} -O{sub 2} potential with experimental potentials of Perugia group and ESMSV-type potential and ab initio potentials (MCRI-1/B3 and CCSD (T)/MCRI mixed model) and NO-NO potential with the recently determined potential by means of ab initio electronic structure calculations, CASSCF/CASPT2 (18/14)/6-311G(2d) have been also included.

  7. Density functional theory study of O-H and C-H bond scission of methanol catalyzed by a chemisorbed oxygen layer on Cu(111)

    Science.gov (United States)

    Li, Jonathan; Zhou, Guangwen

    2016-04-01

    Using the density-functional theory within the generalized gradient approximation, we have studied the partial oxidation of methanol on a Cu(111) surface covered with a chemisorbed oxygen layer that resembles a Cu2O layer. Adsorption energies and geometries were computed for methanol, methoxy, hydroxymethyl and formaldehyde on both clean Cu(111) and Cu2O/Cu(111) and electronic structures were computed for the reaction intermediates on Cu2O/Cu(111). We also calculated the energy barrier for partial oxidation of methanol to formaldehyde on Cu2O/Cu(111). These results show that the Cu2O monolayer slightly lowers the stability of each of the surface adsorbates and the oxygen strongly promotes hydrogen dissociation by lowering the energy barrier of methanol decomposition and causing the spontaneous dissociation of methanol into methoxy.

  8. Temporally shifted hemodynamic response model helps to extract acupuncture-induced functional magnetic resonance imaging blood oxygenation-level dependent activities

    Institute of Scientific and Technical Information of China (English)

    Tsung-Jung Ho; Jeng-Ren Duann; Chun-Ming Chen; Jeon-Hor Chen; Wu-Chung Shen; Tung-Wu Lu; Jan-Ray Liao; Zen-Pin Lin; Kuo-Ning Shaw; Jaung-Geng Lin

    2009-01-01

    Background The onsets of needling sensation introduced by acupuncture stimulus can vary widely from subject to subject.This should be explicitly accounted for by the model blood oxygenation-level dependent (BOLD) time course used in general linear model (GLM) analysis to obtain more consistent across-subject group results.However,in standard GLM analysis,the model BOLD time course obtained by convolving a canonical hemodynamic response function with an experimental paradigm time course is assumed identical across subjects.Although some added-on properties to the model BOLD time course,such as temporal and dispersion derivatives,may be used to account for different BOLD response onsets,they can only account for the BOLD onset deviations to the extent of less than one repetition time (TR).Methods In this study,we explicitly manipulated the onsets of model BOLD time course by shifting it with-2,-1,or 1 TR and used these temporally shifted BOLD model to analyze the functional magnetic resonance imaging (fMRI) data obtained from three acupuncture fMRI experiments with GLM analysis.One involved acupuncture stimulus on left ST42acupoint and the other two on left GB40 and left BL64 acupoints.Results The model BOLD time course with temporal shifts,in addition to temporal and dispersion derivatives,could result in better statistical power of the data analysis in terms of the average correlation coefficients between the used BOLD models and extracted BOLD responses from individual subject data and the T-values of the activation clusters in the grouped random effects.Conclusions The GLM analysis with ordinary BOLD model failed to catch the large variability of the onsets of the BOLD responses associated with the acupuncture needling sensation.Shifts in time with more than a TR on model BOLD time course might be required to better extract the acupuncture stimulus-induced BOLD activities from individual fMRI data.

  9. A density functional theory study of oxygen reduction reaction on non-PGM Fe-Nx-C electrocatalysts.

    Science.gov (United States)

    Kattel, Shyam; Atanassov, Plamen; Kiefer, Boris

    2014-07-21

    First-principles density functional theory (DFT) calculations were performed to explain the stability of catalytically active sites in Fe-Nx-C electrocatalysts, their ORR activity and ORR mechanism. The results show that the formation of graphitic in-plane Fe-N4 sites in a carbon matrix is energetically favorable over the formation of Fe-N2 sites. Chemisorption of ORR species O2, O, OH, OOH, and H2O and O-O bond breaking in peroxide occur on both Fe-N2 and Fe-N4 sites. In addition to the favorable interaction of ORR species, the computed free energy diagrams show that elementary ORR reaction steps on Fe-Nx sites are downhill. Thus, a complete ORR is predicted to occur via a single site 4e(-) mechanism on graphitic Fe-Nx (x = 2, 4) sites. Because of their higher stability and working potential for ORR, Fe-N4 sites are predicted to be prime candidate sites for ORR in pyrolyzed Fe-Nx-C electrocatalysts.

  10. Is this a reflux patient or is it a patient with functional dyspepsia with additional reflux symptoms?

    DEFF Research Database (Denmark)

    Funch-Jensen, P

    1995-01-01

    of functional dyspepsia is less documented and in most studies the symptomatic pattern could not predict the pharmacologic principle of clinical benefit. This may be because a separation between presence of symptoms and presence of symptoms as a major problem has not been taken into account. Cisapride...

  11. The effect of chronic heart failure and type 2 diabetes on insulin-stimulated endothelial function is similar and additive

    DEFF Research Database (Denmark)

    Falskov, Britt; Hermann, Thomas Steffen; Rask-Madsen, Christian;

    2011-01-01

    AIM: Chronic heart failure is associated with endothelial dysfunction and insulin resistance. The aim of this investigation was to study insulin-stimulated endothelial function and glucose uptake in skeletal muscles in patients with heart failure in comparison to patients with type 2 diabetes. ME...

  12. [Apneic oxygenation].

    Science.gov (United States)

    Alekseev, A V; Vyzhigina, M A; Parshin, V D; Fedorov, D S

    2013-01-01

    Recent technological advances in thoracic and tracheal surgery make the anaesthesiologist use different respiratory techniques during the operation. Apneic oxygenation is a one of alternative techniques. This method is relatively easy in use, does not require special expensive equipment and is the only possible technique in several clinical situations when other respiratory methods are undesirable or cannot be used. However there is no enough information about apneic oxygenation in Russian. This article reviews publications about apneic oxygenation. The review deals with experiments on diffusion respiration in animals, physiological changes during apneic oxygenation in man and defines clinical cases when apneic oxygenation can be used.

  13. Functional Resilience and Response to a Dietary Additive (Kefir in Models of Foregut and Hindgut Microbial Fermentation In Vitro

    Directory of Open Access Journals (Sweden)

    Gabriel de la Fuente

    2017-06-01

    Full Text Available Stability in gut ecosystems is an important area of study that impacts on the use of additives and is related with several pathologies. Kefir is a fermented milk drink made with a consortium of yeast and bacteria as a fermentation starter, of which the use as additive in companion and livestock animals has increased in the last few years. To investigate the effect of kefir milk on foregut and hindgut digestive systems, an in vitro approach was followed. Either rumen fluid or horse fecal contents were used as a microbial inoculate and the inclusion of kefir (fresh, autoclaved, or pasteurized was tested. Gas production over 72 h of incubation was recorded and pH, volatile fatty acids (VFAs, lactate and ammonia concentration as well as lactic acid (LAB and acetic acid bacteria, and yeast total numbers were also measured. Both direct and indirect (by subtracting their respective blanks effects were analyzed and a multivariate analysis was performed to compare foregut and hindgut fermentation models. Addition of kefir boosted the fermentation by increasing molar concentration of VFAs and ammonia and shifting the Acetate to Propionate ratio in both models but heat processing techniques like pasteurization or autoclaving influenced the way the kefir is fermented and reacts with the present microbiota. In terms of comparison between both models, the foregut model seems to be less affected by the inclusion of Kefir than the hindgut model. In terms of variability in the response, the hindgut model appeared to be more variable than the foregut model in the way that it reacted indirectly to the addition of different types of kefir.

  14. Functional Resilience and Response to a Dietary Additive (Kefir) in Models of Foregut and Hindgut Microbial Fermentation In Vitro.

    Science.gov (United States)

    de la Fuente, Gabriel; Jones, Eleanor; Jones, Shann; Newbold, Charles J

    2017-01-01

    Stability in gut ecosystems is an important area of study that impacts on the use of additives and is related with several pathologies. Kefir is a fermented milk drink made with a consortium of yeast and bacteria as a fermentation starter, of which the use as additive in companion and livestock animals has increased in the last few years. To investigate the effect of kefir milk on foregut and hindgut digestive systems, an in vitro approach was followed. Either rumen fluid or horse fecal contents were used as a microbial inoculate and the inclusion of kefir (fresh, autoclaved, or pasteurized) was tested. Gas production over 72 h of incubation was recorded and pH, volatile fatty acids (VFAs), lactate and ammonia concentration as well as lactic acid (LAB) and acetic acid bacteria, and yeast total numbers were also measured. Both direct and indirect (by subtracting their respective blanks) effects were analyzed and a multivariate analysis was performed to compare foregut and hindgut fermentation models. Addition of kefir boosted the fermentation by increasing molar concentration of VFAs and ammonia and shifting the Acetate to Propionate ratio in both models but heat processing techniques like pasteurization or autoclaving influenced the way the kefir is fermented and reacts with the present microbiota. In terms of comparison between both models, the foregut model seems to be less affected by the inclusion of Kefir than the hindgut model. In terms of variability in the response, the hindgut model appeared to be more variable than the foregut model in the way that it reacted indirectly to the addition of different types of kefir.

  15. Poly(ethylene glycols as grinding additives in the mechanochemical preparation of highly functionalized 3,5-disubstituted hydantoins

    Directory of Open Access Journals (Sweden)

    Andrea Mascitti

    2017-01-01

    Full Text Available The mechanochemical preparation of highly functionalized 3,5-disubstituted hydantoins was investigated in the presence of various poly(ethylene glycols (PEGs, as safe grinding assisting agents (liquid-assisted grinding, LAG. A comparative study under dry-grinding conditions was also performed. The results showed that the cyclization reaction was influenced by the amount of the PEG grinding agents. In general, cleaner reaction profiles were observed in the presence of PEGs, compared to dry-grinding procedures.

  16. Fixed Points and Stability of an Additive Functional Equation of n-Apollonius Type in C∗-Algebras

    Directory of Open Access Journals (Sweden)

    Fridoun Moradlou

    2008-01-01

    Full Text Available Using the fixed point method, we prove the generalized Hyers-Ulam stability of C∗-algebra homomorphisms and of generalized derivations on C∗-algebras for the following functional equation of Apollonius type ∑i=1nf(z−xi=−(1/n∑1≤i

  17. A hybrid multibreath wash-in wash-out lung function quantification scheme in human subjects using hyperpolarized (3) He MRI for simultaneous assessment of specific ventilation, alveolar oxygen tension, oxygen uptake, and air trapping.

    Science.gov (United States)

    Hamedani, Hooman; Kadlecek, Stephen; Xin, Yi; Siddiqui, Sarmad; Gatens, Heather; Naji, Joseph; Ishii, Masaru; Cereda, Maurizio; Rossman, Milton; Rizi, Rahim

    2017-08-01

    To present a method for simultaneous acquisition of alveolar oxygen tension (PA O2 ), specific ventilation (SV), and apparent diffusion coefficient (ADC) of hyperpolarized (HP) gas in the human lung, allowing reinterpretation of the PA O2 and SV maps to produce a map of oxygen uptake (R). An imaging scheme was designed with a series of identical normoxic HP gas wash-in breaths to measure ADC, SV, PA O2 , and R in less than 2 min. Signal dynamics were fit to an iterative recursive model that regionally solved for these parameters. This measurement was successfully performed in 12 subjects classified in three healthy, smoker, and chronic obstructive pulmonary disease (COPD) cohorts. The overall whole lung ADC, SV, PA O2 , and R in healthy, smoker, and COPD subjects was 0.20 ± 0.03 cm(2) /s, 0.39 ± 0.06,113 ± 2 Torr, and 1.55 ± 0.35 Torr/s, respectively, in healthy subjects; 0.21 ± 0.03 cm(2) /s, 0.33 ± 0.06, 115.9 ± 4 Torr, and 0.97 ± 0.2 Torr/s, respectively, in smokers; and 0.25 ± 0.06 cm(2) /s, 0.23 ± 0.08, 114.8 ± 6.0Torr, and 0.94 ± 0.12 Torr/s, respectively, in subjects with COPD. Hetrogeneity of SV, PA O2 , and R were indicators of both smoking-related changes and disease, and the severity of the disease correlated with the degree of this heterogeneity. Subjects with symptoms showed reduced oxygen uptake and specific ventilation. High-resolution, nearly coregistered and quantitative measures of lung function and structure were obtained with less than 1 L of HP gas. This hybrid multibreath technique produced measures of lung function that revealed clear differences among the cohorts and subjects and were confirmed by correlations with global lung measurements. Magn Reson Med 78:611-624, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  18. Rheological, functional and thermo-physical properties of ultrasound treated whey proteins with addition of sucrose or milk powder

    Directory of Open Access Journals (Sweden)

    Anet Režek Jambrak

    2011-03-01

    Full Text Available Ultrasound represents a non-thermal food processing technique and has great potential to be used in the food industry. The objective of this research was to observe ultrasound impact on physical properties of model systems prepared with whey protein isolates (WPI or whey protein concentrates (WPC with or without sucrose or milk powder addition. This kind of systems is often used in milk beverages and milk based products. Model systems with protein and milk powder or sucrose addition were treated with high power ultrasound (HPU probe of 30 kHz frequency for 5 and 10 minutes. After sonication several properties were determined and examined: solubility, emulsifying and foaming properties, rheological and thermophysical properties. Ultrasound treatment showed severe influence on all examined properties, caused by protein denaturation as a consequence of cavitation and microstreaming effects. Ultrasound treatment caused decrease in protein solubility for whey protein isolate and whey protein concentrates model systems, compared to untreated sample. There was statistically significant increase in foam volume of model systems, prepared with sucrose or milk powder and WPI after ultrasound treatment. Statistically significant decrease in emulsion activity and emulsion stability indices was observed for model systems prepared solely with isolates and concentrates. After treatment of whey protein model systems (with or without milk powder or sucrose with 30 kHz ultrasound, the changes in consistency coefficients (k were observed, but there were no significant changes in flow behaviour indices (n. After addition of milk powder or sucrose, statistically significant decrease in initial freezing and melting temperatures was observed due to the ultrasound treatment.

  19. Mixed Convection Blowoff Limits as a Function of Oxygen Concentration and Upward Forced Stretch Rate for Burning Pmma Rods of Various Sizes

    Science.gov (United States)

    Marcum, Jeremy W.; Ferkul, Paul V.; Olson, Sandra L.

    2017-01-01

    Normal gravity flame blowoff limits in an axisymmetric pmma rod geometry in upward axial stagnation flow are compared with microgravity Burning and Suppression of Solids II (BASS-II) results recently obtained aboard the International Space Station. This testing utilized the same BASS-II concurrent rod geometry, but with the addition of normal gravity buoyant flow. Cast polymethylmethacrylate (pmma) rods of diameters ranging from 0.635 cm to 3.81 cm were burned at oxygen concentrations ranging from 14 to 18 by volume. The forced flow velocity where blowoff occurred was determined for each rod size and oxygen concentration. These blowoff limits compare favorably with the BASS-II results when the buoyant stretch is included and the flow is corrected by considering the blockage factor of the fuel. From these results, the normal gravity blowoff boundary for this axisymmetric rod geometry is determined to be linear, with oxygen concentration directly proportional to flow speed. We describe a new normal gravity upward flame spread test method which extrapolates the linear blowoff boundary to the zero stretch limit to resolve microgravity flammability limits, something current methods cannot do. This new test method can improve spacecraft fire safety for future exploration missions by providing a tractable way to obtain good estimates of material flammability in low gravity.

  20. Cardiac resynchronization therapy and AV optimization increase myocardial oxygen consumption, but increase cardiac function more than proportionally.

    Science.gov (United States)

    Kyriacou, Andreas; Pabari, Punam A; Mayet, Jamil; Peters, Nicholas S; Davies, D Wyn; Lim, P Boon; Lefroy, David; Hughes, Alun D; Kanagaratnam, Prapa; Francis, Darrel P; Whinnett, Zachary I

    2014-02-01

    The mechanoenergetic effects of atrioventricular delay optimization during biventricular pacing ("cardiac resynchronization therapy", CRT) are unknown. Eleven patients with heart failure and left bundle branch block (LBBB) underwent invasive measurements of left ventricular (LV) developed pressure, aortic flow velocity-time-integral (VTI) and myocardial oxygen consumption (MVO2) at 4 pacing states: biventricular pacing (with VV 0 ms) at AVD 40 ms (AV-40), AVD 120 ms (AV-120, a common nominal AV delay), at their pre-identified individualised haemodynamic optimum (AV-Opt); and intrinsic conduction (LBBB). AV-120, relative to LBBB, increased LV developed pressure by a mean of 11(SEM 2)%, p=0.001, and aortic VTI by 11(SEM 3)%, p=0.002, but also increased MVO2 by 11(SEM 5)%, p=0.04. AV-Opt further increased LV developed pressure by a mean of 2(SEM 1)%, p=0.035 and aortic VTI by 4(SEM 1)%, p=0.017. MVO2 trended further up by 7(SEM 5)%, p=0.22. Mechanoenergetics at AV-40 were no different from LBBB. The 4 states lay on a straight line for Δexternal work (ΔLV developed pressure × Δaortic VTI) against ΔMVO2, with slope 1.80, significantly >1 (p=0.02). Biventricular pacing and atrioventricular delay optimization increased external cardiac work done but also myocardial oxygen consumption. Nevertheless, the increase in cardiac work was ~80% greater than the increase in oxygen consumption, signifying an improvement in cardiac mechanoenergetics. Finally, the incremental effect of optimization on external work was approximately one-third beyond that of nominal AV pacing, along the same favourable efficiency trajectory, suggesting that AV delay dominates the biventricular pacing effect - which may therefore not be mainly "resynchronization". © 2013. Published by Elsevier Ireland Ltd. All rights reserved.

  1. Plant functional traits mediate reproductive phenology and success in response to experimental warming and snow addition in Tibet.

    Science.gov (United States)

    Dorji, Tsechoe; Totland, Orjan; Moe, Stein R; Hopping, Kelly A; Pan, Jianbin; Klein, Julia A

    2013-02-01

    Global climate change is predicted to have large impacts on the phenology and reproduction of alpine plants, which will have important implications for plant demography and community interactions, trophic dynamics, ecosystem energy balance, and human livelihoods. In this article we report results of a 3-year, fully factorial experimental study exploring how warming, snow addition, and their combination affect reproductive phenology, effort, and success of four alpine plant species belonging to three different life forms in a semiarid, alpine meadow ecosystem on the central Tibetan Plateau. Our results indicate that warming and snow addition change reproductive phenology and success, but responses are not uniform across species. Moreover, traits associated with resource acquisition, such as rooting depth and life history (early vs. late flowering), mediate plant phenology, and reproductive responses to changing climatic conditions. Specifically, we found that warming delayed the reproductive phenology and decreased number of inflorescences of Kobresia pygmaea C. B. Clarke, a shallow-rooted, early-flowering plant, which may be mainly constrained by upper-soil moisture availability. Because K. pygmaea is the dominant species in the alpine meadow ecosystem, these results may have important implications for ecosystem dynamics and for pastoralists and wildlife in the region.

  2. Symbolic integration of a product of two spherical Bessel functions with an additional exponential and polynomial factor

    Science.gov (United States)

    Gebremariam, B.; Duguet, T.; Bogner, S. K.

    2010-06-01

    We present a Mathematica package that performs the symbolic calculation of integrals of the form ∫0∞exj(x)j(x)dx where j(x) and j(x) denote spherical Bessel functions of integer orders, with ν⩾0 and μ⩾0. With the real parameter u>0 and the integer n, convergence of the integral requires that n+ν+μ⩾0. The package provides analytical result for the integral in its most simplified form. In cases where direct Mathematica implementations succeed in evaluating these integrals, the novel symbolic method implemented in this work obtains the same result and in general, it takes a fraction of the time required for the direct implementation. We test the accuracy of such analytical expressions by comparing the results with their numerical counterparts. Program summaryProgram title: SymbBesselJInteg Catalogue identifier: AEFY_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFY_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 275 934 No. of bytes in distributed program, including test data, etc.: 399 705 Distribution format: tar.gz Programming language: Mathematica 7.1 Computer: Any computer running Mathematica 6.0 and later versions. Operating system: Windows Xp, Linux/Unix. RAM: 256 Mb Classification: 5. Nature of problem: Integration, both analytical and numerical, of products of two spherical Bessel functions with an exponential and polynomial multiplying factor can be a very complex task depending on the orders of the spherical Bessel functions. The Mathematica package discussed in this paper solves this problem using a novel symbolic approach. Solution method: The problem is first cast into a related limit problem which can be broken into two related subproblems involving exponential and exponential integral functions. Solving the cores of each

  3. Dual-energy precursor and nuclear erythroid-related factor 2 activator treatment additively improve redox glutathione levels and neuron survival in aging and Alzheimer mouse neurons upstream of reactive oxygen species.

    Science.gov (United States)

    Ghosh, Debolina; LeVault, Kelsey R; Brewer, Gregory J

    2014-01-01

    To determine whether glutathione (GSH) loss or increased reactive oxygen species (ROS) are more important to neuron loss, aging, and Alzheimer's disease (AD), we stressed or boosted GSH levels in neurons isolated from aging 3xTg-AD neurons compared with those from age-matched nontransgenic (non-Tg) neurons. Here, using titrating with buthionine sulfoximine, an inhibitor of γ-glutamyl cysteine synthetase (GCL), we observed that GSH depletion increased neuronal death of 3xTg-AD cultured neurons at increasing rates across the age span, whereas non-Tg neurons were resistant to GSH depletion until old age. Remarkably, the rate of neuron loss with ROS did not increase in old age and was the same for both genotypes, which indicates that cognitive deficits in the AD model were not caused by ROS. Therefore, we targeted for neuroprotection activation of the redox sensitive transcription factor, nuclear erythroid-related factor 2 (Nrf2) by 18 alpha glycyrrhetinic acid to stimulate GSH synthesis through GCL. This balanced stimulation of a number of redox enzymes restored the lower levels of Nrf2 and GCL seen in 3xTg-AD neurons compared with those of non-Tg neurons and promoted translocation of Nrf2 to the nucleus. By combining the Nrf2 activator together with the NADH precursor, nicotinamide, we increased neuron survival against amyloid beta stress in an additive manner. These stress tests and neuroprotective treatments suggest that the redox environment is more important for neuron survival than ROS. The dual neuroprotective treatment with nicotinamide and an Nrf2 inducer indicates that these age-related and AD-related changes are reversible.

  4. Functional lung MRI in chronic obstructive pulmonary disease: comparison of T1 mapping, oxygen-enhanced T1 mapping and dynamic contrast enhanced perfusion.

    Directory of Open Access Journals (Sweden)

    Bertram J Jobst

    Full Text Available Monitoring of regional lung function in interventional COPD trials requires alternative endpoints beyond global parameters such as FEV1. T1 relaxation times of the lung might allow to draw conclusions on tissue composition, blood volume and oxygen fraction. The aim of this study was to evaluate the potential value of lung Magnetic resonance imaging (MRI with native and oxygen-enhanced T1 mapping for the assessment of COPD patients in comparison with contrast enhanced perfusion MRI.20 COPD patients (GOLD I-IV underwent a coronal 2-dimensional inversion recovery snapshot flash sequence (8 slices/lung at room air and during inhalation of pure oxygen, as well as dynamic contrast-enhanced first-pass perfusion imaging. Regional distribution of T1 at room air (T1, oxygen-induced T1 shortening (ΔT1 and peak enhancement were rated by 2 chest radiologists in consensus using a semi-quantitative 3-point scale in a zone-based approach.Abnormal T1 and ΔT1 were highly prevalent in the patient cohort. T1 and ΔT1 correlated positively with perfusion abnormalities (r = 0.81 and r = 0.80; p&0.001, and with each other (r = 0.80; p<0.001. In GOLD stages I and II ΔT1 was normal in 16/29 lung zones with mildly abnormal perfusion (15/16 with abnormal T1. The extent of T1 (r = 0.45; p<0.05, ΔT1 (r = 0.52; p<0.05 and perfusion abnormalities (r = 0.52; p<0.05 showed a moderate correlation with GOLD stage.Native and oxygen-enhanced T1 mapping correlated with lung perfusion deficits and severity of COPD. Under the assumption that T1 at room air correlates with the regional pulmonary blood pool and that oxygen-enhanced T1 reflects lung ventilation, both techniques in combination are principally suitable to characterize ventilation-perfusion imbalance. This appears valuable for the assessment of regional lung characteristics in COPD trials without administration of i.v. contrast.

  5. The Function and Property of External Additives for Toner%墨粉的外部添加剂的功能和特性

    Institute of Scientific and Technical Information of China (English)

    沈岚; 天野裕贵

    2004-01-01

    External additive can give flowability and charge stability to toner. Various surface treated inorganic oxides are commonly used as an external additive. The basic functions and properties of inorganic fine particle external additive are described.%外部添加剂可以改变墨粉的流动性和电荷的稳定性.表面进行处理的无机氧化物通常是作为外部添加剂来使用,本文介绍了这些超细粒径的外部添加剂的基本功能和特性.

  6. Possibilities of the Technology of Additive Production for Making Complex-Shape Parts and Depositing Functional Coatings from Metallic Powders

    Science.gov (United States)

    Grigor'ev, S. N.; Tarasova, T. V.

    2016-01-01

    The aspects of terminology, definitions and classification in the technology of additive production are considered. The principal possibility of fabrication of complex-shape parts from a refractory cobalt alloy by the method of selective laser melting and deposition of hard and wear-resistant coatings from Ti and SiC powders by coaxial laser surfacing is shown. The technological possibility of microlaser surfacing with lateral resolution about 100 μm in the production of parts from aluminum alloys is considered. The mechanisms of formation of structure in the studied alloys typical for selective laser melting, laser surfacing and microlaser surfacing are determined. The physical and mechanical properties of the alloys are investigated.

  7. Forest soil CO2 fluxes as a function of understory removal and N-fixing species addition

    Institute of Scientific and Technical Information of China (English)

    Haifang Li; Shenglei Fu; Hongting Zhao; Hanping Xia

    2011-01-01

    We report on the effects of forest management practices of understory removal and N-fixing species (Cassia alata) addition on soil CO2 fluxes in an Eucalyptus urophylla plantation (EUp), Acacia crassicarpa plantation (ACp), 10-species-mixed plantation (Tp), and 30-species-mixed plantation (THp) using the static chamber method in southern China. Four forest management treatments, including (1) understory removal (UR); (2) C. alata addition (CA); (3) understory removal and replacement with C. alata (UR+CA); and (4)control without any disturbances (CK), were applied in the above four forest plantations with three replications for each treatment.The results showed that soil CO2 fluxes rates remained at a high level during the rainy season (from April to September), followed by a rapid decrease after October reaching a minimum in February. Soil CO2 fluxes were significantly higher (P < 0.01) in EUp (132.6 mg/(m2·hr)) and ACp (139.8 mg/(m2·hr)) than in Tp (94.0 mg/(m2·hr)) and THp (102.9 mg/(m2·hr)). Soil CO2 fluxes in UR and CA were significantly higher (P < 0.01) among the four treatments, with values of 105.7, 120.4, 133.6 and 112.2 mg/(m2·hr) for UR+CA,UR, CA and CK, respectively. Soil CO2 fluxes were positively correlated with soil temperature (P < 0.01), soil moisture (P < 0.01),NO3--N (P < 0.05), and litterfall (P < 0.01), indicating that all these factors might be important controlling variables for soil CO2 fluxes. This study sheds some light on our understanding of soil CO2 flux dynamics in forest plantations under various management practices.

  8. Effect of ultraviolet blood irradiation and oxygenation on nerve function and function of the red blood cell membrane pump in patients with acute cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    Jiaquan Wang; Chun Mao; Kaifu Ma; Shiqing Wang

    2006-01-01

    BACKGROUND: Ultraviolet blood irradiation and oxygenation (UBIO) has obtained better clinical effect in treating acute cerebral infarction, but the mechanism underlying this effect remains unclear.OBJECTIVE: To observe the effect of UBIO on the nerve function and activities of K+-Na+-ATPase and Ca2+-Mg2+-ATPase activities on the red blood cell (RBC) membrane of patients with acute cerebral infarction.DESIGN: A randomized and controlled study.SETTING: Department of Neurology, Xiangfan Central Hospital.PARTICIPANTS: From January 2000 to December 2001, excluding those above 70 years old, 58 cases of 700 patients with acute cerebral infarction admitted in the Department of Neurology, Xiangfan Central Hospital, were recruited and divided into two groups according to the random number table: UBIO treated group (n=28), including 17 males and 11 females, aged 40-68 years; and control group (n=30), including 20males and 10 females, aged 44-69 years. All the patients agreed to participate in the therapeutic program and detected items. The general informations were comparable without obvious differences between the two groups (P > 0.05).METHODS: ① The patients in both groups received routine treatments, besides, those in the UBIO treated group were given UBIO treatment by using the XL-200 type therapeutic apparatus produced in Shijiazhuang, whose ultraviolet wave was set at 253.7 nm with the energy density of 0.568 J/m2 per second, UBIO treatment started from the second day after admission, once every other day, with a single course consisting of 5-7 treatments. ② In the UBIO treated group, the venous blood was sampled before and after the first, third and the completion of the treatment course respectively, the venous blood was taken at each corresponding time point in the control group. After centrifugation of the blood at 10 000 rounds per minute,the RBC membrane was separated and then the activities of K+-Na+-ATPase and Ca2+-Mg2+-ATPase were detected by means of

  9. The dual role of oxygen functions in coal pretreatment and liquefaction: Crosslinking and cleavage reactions. First annual report, April 1, 1991--March 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Serio, M.A.; Kroo, E.; Teng, H.; Charpenay, S.; Solomon, P.R.

    1992-08-01

    The overall objective of this project is elucidate and model the dual role of oxygen functions in thermal pretreatment and liquefaction of low rank coals through the application of analytical techniques and theoretical models. The project will be an integrated study of model polymers representative of coal structures, raw coals of primarily low rank, and selectivity modified coals in order to provide specific information relevant to the reactions of real coals. The investigations will include liquefaction experiments in microautoclave reactors along with extensive analysis of intermediate solid, liquid and gaseous products. Attempts will be made to incorporate the results of experiments on the different systems into a liquefaction model.

  10. Casein addition to a whey-based formula has limited effects on gut function in preterm pigs

    DEFF Research Database (Denmark)

    Thymann, T.; Støy, Ann Cathrine Findal; Bering, S. B.

    2012-01-01

    followed by 30 h of enteral feeding with whey [protein fraction of milk formula based on whey (WHEY); n = 11] or casein and/or whey [protein fraction of milk formula based on a combination of casein and whey (CASEIN); n = 9]-based formulas. Sugar absorptive function was investigated at 6 and 30 h after......Preterm infants are susceptible to necrotizing enterocolitis (NEC). Using preterm pigs, we determined whether a whey–casein-based formula would be superior to a formula based on whey protein alone. Twenty cesarean-derived preterm pigs (92% gestation) were given total parenteral nutrition for 36 h...... studied in gut contents. Severity of NEC lesions was similar between diet groups but galactose absorption was markedly higher in CASEIN than in WHEY (P

  11. Function-Biased Choice of Additives for Optimization of Protein Crystallization: The Case of the Putative Thioesterase PA5185 from Pseudomonas aeruginosa PAO1

    Energy Technology Data Exchange (ETDEWEB)

    Chruszcz, Maksymilian; Zimmerman, Matthew D.; Wang, Shuren; Koclega, Katarzyna D.; Zheng, Heping; Evdokimova, Elena; Kudritska, Marina; Cymborowski, Marcin; Savchenko, Alexei; Edwards, Aled; Minor, Wladek (Toronto); (UV)

    2009-09-15

    The crystal structure of PA5185, a putative thioesterase from Pseudomonas aeruginosa strain PAO1, was solved using multi-wavelength anomalous diffraction to 2.4 {angstrom}. Analysis of the structure and information about the putative function of the protein were used to optimize crystallization conditions. The crystal growth was optimized by applying additives with chemical similarity to a fragment of a putative PA5185 substrate (CoA or its derivative). Using new crystallization conditions containing this function-biased set of additives, several new crystal forms were produced, and structures of three of them (in three different space groups) were determined. One of the new crystal forms had an improved resolution limit of 1.9 {angstrom}, and another displayed an alternative conformation of the highly conserved loop containing Asn26, which could play a physiological role. Surprisingly, none of the additives were ordered in the crystal structures. Application of function-biased additives could be used as a standard optimization protocol for producing improved diffraction, or new crystal forms, which may lead to better understanding of the biological functions of proteins.

  12. Basic-functionalized recyclable ionic liquid catalyst: A solvent-free approach for Michael addition of 1,3-dicarbonyl compounds to nitroalkenes under ultrasound irradiation.

    Science.gov (United States)

    Narayanaperumal, Senthil; da Silva, Rodrigo César; Feu, Karla Santos; de la Torre, Alexander Fernández; Corrêa, Arlene G; Paixão, Márcio Weber

    2013-05-01

    A task-specific ionic liquid (TSIL) has been introduced as a recyclable catalyst in Michael addition. A series of nitroalkenes and various C-based nucleophiles were reacted in the presence of 30mol% of recyclable basic-functionalized ionic liquid. Good to excellent yields were obtained in 30min under ultrasound irradiation.

  13. Design and analysis of a piezoelectric material based touch screen with additional pressure and its acceleration measurement functions

    Science.gov (United States)

    Chu, Xiang-Cheng; Liu, Jia-Yi; Gao, Ren-Long; Chang, Jie; Li, Long-Tu

    2013-12-01

    Touch screens are becoming more and more prevalent in everyday environments due to their convenience and humanized operation. In this paper, a piezoelectric material based touch screen is developed and investigated. Piezoelectric ceramics arrayed under the touch panel at the edges or corners are used as tactile sensors to measure the touch positioning point similarly to conventional touch screens. However, additional touch pressure and its acceleration performance can also be obtained to obtain a higher-level human-machine interface. The piezoelectric ceramics can also be added to a traditional touch screen structure, or they can be used independently to construct a novel touch screen with a high light transmittance approach to a transparent glass. The piezoelectric ceramics were processed from PZT piezoelectric ceramic powder into a round or rectangular shape. According to the varied touch position and physical press strength of a finger, or even a gloved hand or fingernail, the piezoelectric tactile sensors will have different output voltage responses. By calculating the ratio of different piezoelectric tactile sensors’ responses and summing up all piezoelectric tactile sensors’ output voltages, the touch point position, touch pressure and touch force acceleration can be detected. A prototype of such a touch screen is manufactured and its position accuracy, touch pressure and response speed are measured in detail. The experimental results show that the prototype has many advantages such as high light transmittance, low energy cost and high durability.

  14. An Alkaline Protease from Bacillus pumilus MP 27: Functional Analysis of its Binding Model towards its Applications as Detergent Additive

    Directory of Open Access Journals (Sweden)

    Mehak Baweja

    2016-08-01

    Full Text Available A proteolytic strain of Bacillus pumilus MP 27 was isolated from water samples of Southern ocean produced alkaline protease. Since protease production need expensive ingredients, an economically viable process was developed by using low cost carbon source, wheat straw, supplemented with peptone. This protease was active within temperature ranges 10˚C -70˚C at pH 9. This process was optimized by response surface methodology using a Box Bekhman design by Design Expert 7.0 software that increased the protease activity to 776.5 U/ml. Moreover, the enzyme was extremely stable at a broad range of temperature and pH retaining 69% of its activity at 50 ºC and 70% at pH 11. The enzyme exhibited excellent compatibility with surfactants and commercial detergents, showing 87% stability with triton X-100 and ̴ 100% stability with Tide commercial detergent. The results of the wash performance analysis demonstrated considerably good de-staining at 50ºC and 4ºC with low supplementation (109 U/ml. Molecular modeling of the protease revealed the presence of serine proteases, subtilase family and serine active site and further docking supported the association of catalytic site with the various substrates. Certainly, such protease can be considered as a good detergent additive in detergent industry with a possibility to remove the stains effectively even in a cold wash.

  15. An Alkaline Protease from Bacillus pumilus MP 27: Functional Analysis of Its Binding Model toward Its Applications As Detergent Additive.

    Science.gov (United States)

    Baweja, Mehak; Tiwari, Rameshwar; Singh, Puneet K; Nain, Lata; Shukla, Pratyoosh

    2016-01-01

    A proteolytic strain of Bacillus pumilus MP 27 was isolated from water samples of Southern ocean produced alkaline protease. Since protease production need expensive ingredients, an economically viable process was developed by using low cost carbon source, wheat straw, supplemented with peptone. This protease was active within temperature ranges 10-70°C at pH 9. This process was optimized by response surface methodology using a Box Bekhman design by Design Expert 7.0 software that increased the protease activity to 776.5 U/ml. Moreover, the enzyme was extremely stable at a broad range of temperature and pH retaining 69% of its activity at 50°C and 70% at pH 11. The enzyme exhibited excellent compatibility with surfactants and commercial detergents, showing 87% stability with triton X-100 and 100% stability with Tide commercial detergent. The results of the wash performance analysis demonstrated considerably good de-staining at 50 and 4°C with low supplementation (109 U/ml). Molecular modeling of the protease revealed the presence of serine proteases, subtilase family and serine active site and further docking supported the association of catalytic site with the various substrates. Certainly, such protease can be considered as a good detergent additive in detergent industry with a possibility to remove the stains effectively even in a cold wash.

  16. Density Functional Theory Research into the Reduction Mechanism for the Solvent/Additive in a Sodium-Ion Battery.

    Science.gov (United States)

    Liu, Qi; Mu, Daobin; Wu, Borong; Wang, Lei; Gai, Liang; Wu, Feng

    2017-02-22

    The solid-electrolyte interface (SEI) film in a sodium-ion battery is closely related to capacity fading and cycling stability of the battery. However, there are few studies on the SEI film of sodium-ion batteries and the mechanism of SEI film formation is unclear. The mechanism for the reduction of ethylene carbonate (EC), propylene carbonate (PC), vinylene carbonate (VC), ethylene sulfite (ES), 1,3-propylene sulfite (PS), and fluorinated ethylene carbonate (FEC) is studied by DFT. The reaction activation energies, Gibbs free energies, enthalpies, and structures of the transition states are calculated. It is indicated that VC, ES, and PS additives in the electrolyte are all easier to form organic components in the anode SEI film by one-electron reduction. The priority of one-electron reduction to produce organic SEI components is in the order of VC>PC>EC; two-electron reduction to produce the inorganic Na2 CO3 component is different and follows the order of EC>PC>VC. Two-electron reduction for sulfites ES and PS to form inorganic Na2 SO3 is harder than that of carbonate ester reduction. It is also suggested that the one- and two-electron reductive decomposition pathway for FEC is more feasible to produce inorganic NaF components. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Oxygen Therapy

    OpenAIRE

    2000-01-01

    LTOT is prescribed for people with chronic lung disease in whom there is a decrease in the ability of the lungs to supply enough oxygen to the body. The heart is obliged to pump faster to meet the body's oxygen requirements. This may place undue stress on the heart, resulting in palpitations, dizziness and fatigue. A low oxygen level in arterial blood is also harmful to the heart, the brain and the pulmonary blood vessels. Oxygen therapy is used to break this cycle. A person with low blood ox...

  18. Cardiac resynchronization therapy and AV optimization increase myocardial oxygen consumption, but increase cardiac function more than proportionally☆

    Science.gov (United States)

    Kyriacou, Andreas; Pabari, Punam A.; Mayet, Jamil; Peters, Nicholas S.; Davies, D. Wyn; Lim, P. Boon; Lefroy, David; Hughes, Alun D.; Kanagaratnam, Prapa; Francis, Darrel P.; I.Whinnett, Zachary

    2014-01-01

    Background The mechanoenergetic effects of atrioventricular delay optimization during biventricular pacing (“cardiac resynchronization therapy”, CRT) are unknown. Methods Eleven patients with heart failure and left bundle branch block (LBBB) underwent invasive measurements of left ventricular (LV) developed pressure, aortic flow velocity-time-integral (VTI) and myocardial oxygen consumption (MVO2) at 4 pacing states: biventricular pacing (with VV 0 ms) at AVD 40 ms (AV-40), AVD 120 ms (AV-120, a common nominal AV delay), at their pre-identified individualised haemodynamic optimum (AV-Opt); and intrinsic conduction (LBBB). Results AV-120, relative to LBBB, increased LV developed pressure by a mean of 11(SEM 2)%, p = 0.001, and aortic VTI by 11(SEM 3)%, p = 0.002, but also increased MVO2 by 11(SEM 5)%, p = 0.04. AV-Opt further increased LV developed pressure by a mean of 2(SEM 1)%, p = 0.035 and aortic VTI by 4(SEM 1)%, p = 0.017. MVO2 trended further up by 7(SEM 5)%, p = 0.22. Mechanoenergetics at AV-40 were no different from LBBB. The 4 states lay on a straight line for Δexternal work (ΔLV developed pressure × Δaortic VTI) against ΔMVO2, with slope 1.80, significantly > 1 (p = 0.02). Conclusions Biventricular pacing and atrioventricular delay optimization increased external cardiac work done but also myocardial oxygen consumption. Nevertheless, the increase in cardiac work was ~ 80% greater than the increase in oxygen consumption, signifying an improvement in cardiac mechanoenergetics. Finally, the incremental effect of optimization on external work was approximately one-third beyond that of nominal AV pacing, along the same favourable efficiency trajectory, suggesting that AV delay dominates the biventricular pacing effect — which may therefore not be mainly “resynchronization”. PMID:24332598

  19. Oxygen precipitation behavior in heavily arsenic doped silicon crystals

    Science.gov (United States)

    Haringer, Stephan; Gambaro, Daniela; Porrini, Maria

    2017-01-01

    Silicon crystals containing different levels of arsenic concentration and oxygen content were grown, and samples were taken at various positions along the crystal, to study the influence of three main factors, i.e. the initial oxygen content, the dopant concentration and the thermal history, on the nucleation of oxygen precipitates during crystal growth and cooling in the puller. The crystal thermal history was reconstructed by means of computer modeling, simulating the temperature distribution in the crystal at several growth stages. The oxygen precipitation was characterized after a thermal cycle of 4 h at 800 °C for nuclei stabilization +16 h at 1000 °C for nuclei growth. Oxygen precipitates were counted under microscope on the cleaved sample surface after preferential etching. Lightly doped silicon samples were also included, as reference. Our results show that even in heavily arsenic doped silicon the oxygen precipitation is a strong function of the initial oxygen concentration, similar to what has been observed for lightly doped silicon. In addition, a precipitation retardation effect is observed in the arsenic doped samples when the dopant concentration is higher than 1.7×1019 cm-3 compared to lightly doped samples with the same initial oxygen content and crystal thermal history. Finally, a long permanence time of the crystal in the temperature range between 450 °C and 750 °C enhances the oxygen precipitation, showing that this is an effective temperature range for oxygen precipitation nucleation in heavily arsenic doped silicon.

  20. Casein addition to a whey-based formula has limited effects on gut function in preterm pigs.

    Science.gov (United States)

    Thymann, T; Støy, C A F; Bering, S B; Mølbak, L; Sangild, P T

    2012-12-01

    Preterm infants are susceptible to necrotizing enterocolitis (NEC). Using preterm pigs, we determined whether a whey-casein-based formula would be superior to a formula based on whey protein alone. Twenty cesarean-derived preterm pigs (92% gestation) were given total parenteral nutrition for 36 h followed by 30 h of enteral feeding with whey [protein fraction of milk formula based on whey (WHEY); n = 11] or casein and/or whey [protein fraction of milk formula based on a combination of casein and whey (CASEIN); n = 9]-based formulas. Sugar absorptive function was investigated at 6 and 30 h after initiation of enteral feeding using bolus feedings with galactose and mannitol. Pigs were killed after the last in vivo sugar absorption test and evaluated for NEC and the mid intestine was used for ex vivo measurements of hexose absorption. Microbiota profile and short chain fatty acid (SCFA) levels were studied in gut contents. Severity of NEC lesions was similar between diet groups but galactose absorption was markedly higher in CASEIN than in WHEY (P SCFA concentration. Casein may transiently stimulate intestinal sugar absorption but has limited effects on gut structure, microbiota, and NEC in preterm pigs.

  1. Cerebral blood oxygenation changes during neuronal activation in stroke patients measured by near infrared spectroscopy and BOLD-functional MRI

    Energy Technology Data Exchange (ETDEWEB)

    Murata, Yoshihiro; Fukaya, Chikashi; Sakatani, Kaoru; Katayama, Yoichi [Nihon Univ., Tokyo (Japan). School of Medicine

    2002-03-01

    Blood Oxygenation Level Dependent (BOLD)-fMRI images areas of activation by detecting a reduced concentration of deoxyhemoglobin during neuronal activity, which is caused by a larger increase in O{sub 2} delivery as compared to O{sub 2} consumption in normal adults. In the present study, near infrared spectroscopy demonstrated an increase of deoxyhemoglobin associated with increases of oxyhemoglobin and total hemoglobin in activation areas of stroke patients, whereas BOLD-fMRI failed to image such activation areas. The findings obtained have serious implications for the application of BOLD-fMRI to patients with brain disorders, since BOLD-fMRI may overlook neuronal activities in these patients. (author)

  2. Direct Synthesis of Fe3C-Functionalized Graphene by High Temperature Autoclave Pyrolysis for Oxygen Reduction

    DEFF Research Database (Denmark)

    Hu, Yang; Jensen, Jens Oluf; Zhang, Wei

    2014-01-01

    We present a novel approach to direct fabrication of few-layer graphene sheets with encapsulated Fe3C nanoparticles from pyrolysis of volatile non-graphitic precursors without any substrate. This one-step autoclave approach is facile and potentially scalable for production. Tested as an electroca......We present a novel approach to direct fabrication of few-layer graphene sheets with encapsulated Fe3C nanoparticles from pyrolysis of volatile non-graphitic precursors without any substrate. This one-step autoclave approach is facile and potentially scalable for production. Tested...... as an electrocatalyst, the graphene-based composite exhibited excellent catalytic activity towards the oxygen reduction reaction in alkaline solution with an onset potential of ca. 1.05 V (vs. the reversible hydrogen electrode) and a half-wave potential of 0.83 V, which is comparable to the commercial Pt/C catalyst....

  3. Direct synthesis of Fe3 C-functionalized graphene by high temperature autoclave pyrolysis for oxygen reduction.

    Science.gov (United States)

    Hu, Yang; Jensen, Jens Oluf; Zhang, Wei; Huang, Yunjie; Cleemann, Lars N; Xing, Wei; Bjerrum, Niels J; Li, Qingfeng

    2014-08-01

    We present a novel approach to direct fabrication of few-layer graphene sheets with encapsulated Fe3 C nanoparticles from pyrolysis of volatile non-graphitic precursors without any substrate. This one-step autoclave approach is facile and potentially scalable for production. Tested as an electrocatalyst, the graphene-based composite exhibited excellent catalytic activity towards the oxygen reduction reaction in alkaline solution with an onset potential of ca. 1.05 V (vs. the reversible hydrogen electrode) and a half-wave potential of 0.83 V, which is comparable to the commercial Pt/C catalyst. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Angular distribution, kinetic energy distributions, and excitation functions of fast metastable oxygen fragments following electron impact of CO2

    Science.gov (United States)

    Misakian, M.; Mumma, M. J.; Faris, J. F.

    1975-01-01

    Dissociative excitation of CO2 by electron impact was studied using the methods of translational spectroscopy and angular distribution analysis. Earlier time of flight studies revealed two overlapping spectra, the slower of which was attributed to metastable CO(a3 pi) fragments. The fast peak is the focus of this study. Threshold energy, angular distribution, and improve time of flight measurements indicate that the fast peak actually consists of five overlapping features. The slowest of the five features is found to consist of metastable 0(5S) produced by predissociation of a sigma u + state of CO2 into 0(5S) + CO(a3 pi). Oxygen Rydberg fragments originating directly from a different sigma u + state are believed to make up the next fastest feature. Mechanisms for producing the three remaining features are discussed.

  5. Brain tissue oxygen amperometry in behaving rats demonstrates functional dissociation of dorsal and ventral hippocampus during spatial processing and anxiety

    OpenAIRE

    McHugh, Stephen B.; Fillenz, Marianne; Lowry, John P; Rawlins, J Nicolas P; Bannerman, David M.

    2011-01-01

    Traditionally, the function of the hippocampus (HPC) has been viewed in unitary terms, but there is growing evidence that the HPC is functionally differentiated along its septotemporal axis. Lesion studies in rodents and functional brain imaging in humans suggest a preferential role for the septal HPC in spatial learning and a preferential role for the temporal HPC in anxiety. To better enable cross-species comparison, we present an in vivo amperometric technique that measures changes in brai...

  6. Noninvasively measuring oxygen saturation of human finger-joint vessels by multi-transducer functional photoacoustic tomography

    Science.gov (United States)

    Deng, Zijian; Li, Changhui

    2016-06-01

    Imaging small blood vessels and measuring their functional information in finger joint are still challenges for clinical imaging modalities. In this study, we developed a multi-transducer functional photoacoustic tomography (PAT) system and successfully imaged human finger-joint vessels from ˜1 mm to anatomical and functional information of individual finger-joint vessels with different sizes, which might help the study of finger-joint diseases, such as rheumatoid arthritis.

  7. Reactive oxygen species in iridium-based OER catalysts† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c6sc01860b Click here for additional data file.

    Science.gov (United States)

    Pfeifer, Verena; Wrabetz, Sabine; Massué, Cyriac; Velasco Vélez, Juan J.; Arrigo, Rosa; Scherzer, Michael; Piccinin, Simone; Hävecker, Michael; Knop-Gericke, Axel; Schlögl, Robert

    2016-01-01

    Tremendous effort has been devoted towards elucidating the fundamental reasons for the higher activity of hydrated amorphous IrIII/IV oxyhydroxides (IrOx) in the oxygen evolution reaction (OER) in comparison with their crystalline counterpart, rutile-type IrO2, by focusing on the metal oxidation state. Here we demonstrate that, through an analogy to photosystem II, the nature of this reactive species is not solely a property of the metal but is intimately tied to the electronic structure of oxygen. We use a combination of synchrotron-based X-ray photoemission and absorption spectroscopies, ab initio calculations, and microcalorimetry to show that holes in the O 2p states in amorphous IrOx give rise to a weakly bound oxygen that is extremely susceptible to nucleophilic attack, reacting stoichiometrically with CO already at room temperature. As such, we expect this species to play the critical role of the electrophilic oxygen involved in O–O bond formation in the electrocatalytic OER on IrOx. We propose that the dynamic nature of the Ir framework in amorphous IrOx imparts the flexibility in Ir oxidation state required for the formation of this active electrophilic oxygen. PMID:28042464

  8. Non-Maxwellian velocity distribution functions associated with steep temperature gradients in the solar transition region. Paper 2: The effect of non-Maxwellian electron distribution functions on ionization equilibrium calculations for carbon, nitrogen and oxygen

    Science.gov (United States)

    Roussel-Dupre, R.

    1979-01-01

    Non-Maxwellian electron velocity distribution functions, previously computed for Dupree's model of the solar transition region are used to calculate ionization rates for ions of carbon, nitrogen, and oxygen. Ionization equilibrium populations for these ions are then computed and compared with similar calculations assuming Maxwellian distribution functions for the electrons. The results show that the ion populations change (compared to the values computed with a Maxwellian) in some cases by several orders of magnitude depending on the ion and its temperature of formation.

  9. The effect of radiation-induced reactive oxygen species (ROS) on the structural and functional properties of yeast alcohol dehydrogenase (YADH).

    Science.gov (United States)

    Rodacka, Aleksandra

    2016-01-01

    To determine the mechanism underlying oxidative modifications caused by radiation-induced reactive oxygen species (ROS) and elucidate their effect on the structure and function of yeast alcohol dehydrogenase (YADH), a zinc-containing protein. YADH was exposed to water radiolysis products in an air atmosphere. YADH oxidation products were determined by spectrophotometric and spectrofluorimetric methods. The extent to which oxidative modifications affected enzyme activity was also studied. Water radiolysis products oxidized thiol groups leading to the release of zinc ions and the destruction of tryptophan and tyrosine residues. Those processes were accompanied by alterations in protein structure such as increased surface hydrophobicity, greater tryptophan accessibility to acrylamide, and changes in the secondary structure. Structural modifications were correlated with lower enzyme activity. During the process of functional and structural changes in YADH exposed to reactive oxygen species, a key part is the oxidation of cysteine residues attached to zinc and the release of zinc ions from the molecule. It may be assumed that ROS induce similar changes in many other zinc-containing proteins.

  10. Appreciating Oxygen

    Science.gov (United States)

    Weiss, Hilton M.

    2008-01-01

    Photosynthetic flora and microfauna utilize light from the sun to convert carbon dioxide and water into carbohydrates and oxygen. While these carbohydrates and their derivative hydrocarbons are generally considered to be fuels, it is the thermodynamically energetic oxygen molecule that traps, stores, and provides almost all of the energy that…

  11. Interactions of water and nitrogen addition on soil microbial community composition and functional diversity depending on the inter-annual precipitation in a Chinese steppe

    Institute of Scientific and Technical Information of China (English)

    SUN Liang-jie; QI Yu-chun; DONG Yun-she; HE Ya-ting; PENG Qin; LIU Xin-chao; JIA Jun-qiang; GUO Shu-fang; CAO Cong-cong

    2015-01-01

    Water and nitrogen are primary limiting factors in semiarid grassland ecosystems. Our knowledge is stil poor regarding the interactive effects of water and N addition on soil microbial communities, although this information is crucial to reveal the mechanisms of the terrestrial ecosystem response to global changes. We addressed this problem by conducting a ifeld experiment with a 15%surplus of the average rainfal under three levels of N addition (50, 100, and 200 kg N ha–1 yr–1) in two consecutive years in Inner Mongolia, China. Microbial community composition and functional diversity were analyzed based on phospholipid fatty acids (PLFA) and BIOLOG techniques, respectively. The results showed that water addition did not affect the soil microbial community composition, but much more yearly precipitation general y decreased the PLFA concentration, which implied a fast response of soil microbes to changes of water condition. Soil fungi was depressed only by N addition at the high level (200 kg N ha–1 yr–1) and without hydrologic leaching, while Gram-negative bacteria was suppressed probably by plant competition at high level N addition but with hydrologic leaching. The study found unilateral positive/negative interactions between water and N addition in affecting soil microbial community, however, climate condi-tion (precipitation) could be a signiifcant factor in disturbing the interactions. This study highlighted that:(1) The sustained effect of pulsed water addition was minimal on the soil microbial community composition but signiifcant on the microbial community functional diversity and (2) the complex interaction between water and N addition on soil microbial community related to the inter-annual variation of the climate and plant response.

  12. How do Elevated CO2 and Nitrogen Addition Affect Functional Microbial Community Involved in Greenhouse Gas Flux in Salt Marsh System.

    Science.gov (United States)

    Lee, Seung-Hoon; Megonigal, Patrick J; Kang, Hojeong

    2017-03-22

    Salt marshes are unique ecosystem of which a microbial community is expected to be affected by global climate change. In this study, by using T-RFLP analysis, quantitative PCR, and pyrosequencing, we comprehensively analyzed the microbial community structure responding to elevated CO2 (eCO2) and N addition in a salt marsh ecosystem subjected to CO2 manipulation and N addition for about 3 years. We focused on the genes of microbes relevant to N-cycling (denitrification and nitrification), CH4-flux (methanogens and methanotrophs), and S-cycling (sulfate reduction) considering that they are key functional groups involved in the nutrient cycle of salt marsh system. Overall, this study suggests that (1) eCO2 and N addition affect functional microbial community involved in greenhouse gas flux in salt marsh system. Specifically, the denitrification process may be facilitated, while the methanogenesis may be impeded due to the outcompeting of sulfate reduction by eCO2 and N. This implies that future global change may cause a probable change in GHGs flux and positive feedback to global climate change in salt marsh; (2) the effect of eCO2 and N on functional group seems specific and to contrast with each other, but the effect of single factor would not be compromised but complemented by combination of two factors. (3) The response of functional groups to eCO2 and/or N may be directly or indirectly related to the plant community and its response to eCO2 and/or N. This study provides new insights into our understanding of functional microbial community responses to eCO2 and/or N addition in a C3/C4 plant mixed salt marsh system.

  13. Functional separation of oxidation–reduction reactions and electron transport in PtRu/ND and conductive additive hybrid electrocatalysts during methanol oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yan; Wang, Yanhui [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Bian, Linyan [College of Physics and Chemistry, Henan Polytechnic University, Jiaozuo, Henan 454000 (China); Lu, Rui [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Zang, Jianbing, E-mail: jbzang@ysu.edu.cn [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China)

    2016-02-28

    Graphical abstract: - Highlights: • Functional separation of reactions and electron transport in PtRu/ND + AB (or CNT). • A conductive network was formed after the addition of AB or CNT. • PtRu/ND + AB (or CNT) exhibited enhanced activity and stability than PtRu/ND. - Abstract: Undoped nanodiamond (ND) supported PtRu (PtRu/ND) electrocatalyst for methanol oxidation reactions (MOR) in direct methanol fuel cells was prepared by a microwave-assisted polyol reduction method. Sp{sup 3}-bonded ND possesses high electrochemical stability but low conductivity, while sp{sup 2}-bonded carbon nanomaterials with high conductivity are prone to oxidation. Therefore, the functions of the supporting material were separated in this study. ND (sp{sup 3}), as a support, and AB or CNTs (sp{sup 2}), as a conductive additive, were combined to form the hybrid electrocatalysts PtRu/ND + AB and PtRu/ND + CNT for MOR. The morphology of the electrocatalysts was characterized by scanning electron microscopy and electrochemical measurements were performed using an electrochemical workstation. The results indicated that the electrocatalytic activity of PtRu/ND for MOR was improved with the addition of AB or CNTs as a conductive additive. Moreover, adding CNTs to PtRu/ND as a conductive additive showed better electrocatalytic activities than adding AB, which can be ascribed to the better electron-transfer ability of CNTs.

  14. Structure and function of nematode communities across the Indian western continental margin and its oxygen minimum zone

    Digital Repository Service at National Institute of Oceanography (India)

    Singh, R.; Ingole, B.S.

    functional group was not a simple reflection of the information in species abundance. Ecological information captured by adult length, adult shape, and life-history strategy was less sitespecific and thus differed notably from information contained in other...

  15. Expression of a functional oxygen-labile nitrogenase component in the mitochondrial matrix of aerobically grown yeast

    Science.gov (United States)

    López-Torrejón, Gema; Jiménez-Vicente, Emilio; Buesa, José María; Hernandez, Jose A.; Verma, Hemant K.; Rubio, Luis M.

    2016-01-01

    The extreme sensitivity of nitrogenase towards oxygen stands as a major barrier to engineer biological nitrogen fixation into cereal crops by direct nif gene transfer. Here, we use yeast as a model of eukaryotic cell and show that aerobically grown cells express active nitrogenase Fe protein when the NifH polypeptide is targeted to the mitochondrial matrix together with the NifM maturase. Co-expression of NifH and NifM with Nif-specific Fe–S cluster biosynthetic proteins NifU and NifS is not required for Fe protein activity, demonstrating NifH ability to incorporate endogenous mitochondrial Fe–S clusters. In contrast, expression of active Fe protein in the cytosol requires both anoxic growth conditions and co-expression of NifH and NifM with NifU and NifS. Our results show the convenience of using mitochondria to host nitrogenase components, thus providing instrumental technology for the grand challenge of engineering N2-fixing cereals. PMID:27126134

  16. Functionalization of the benzobicyclo[3.2.1] octadiene skeleton possessing one isolated double bond via photocatalytic oxygenation

    Science.gov (United States)

    Vuk, Dragana; Horváth, Ottó; Marinić, Željko; Škorić, Irena

    2016-03-01

    Photocatalytic oxygenation of three phenyl derivatives of a bicyclic skeleton with a free double bond 1a, 1b and 1c were carried out by utilizing a cationic and an anionic manganese(III) porphyrin irradiated in the visible range. While photocatalysis of 1a and 1b led to the formation of the corresponding hydroperoxy derivatives 2 and 3, respectively, (besides unidentified high-molecular-weight products) in the presence of the anionic Mn(III) porphyrin, the cationic photocatalyst proved to be less efficient and less selective with 1a. In the case of 1b, also with the cationic porphyrin, the corresponding hydroperoxy derivative (3) was the main product at a shorter reaction time (2 h), whereas a longer irradiation (4 h) led to the significant formation of a keto derivative (5) with a hydroperoxy substituent and a free double bond at positions deviating from those in the previous products (2 and 3). A dramatic change in the reactivity was observed for the methoxy derivative (1c). It gave only traces of identifiable products by using the anionic photocatalyst, while application of the cationic Mn(III) porphyrin resulted in a relatively efficient formation of an epoxy derivative (6) due to the reaction of the isolated double bond.

  17. Expression of a functional oxygen-labile nitrogenase component in the mitochondrial matrix of aerobically grown yeast.

    Science.gov (United States)

    López-Torrejón, Gema; Jiménez-Vicente, Emilio; Buesa, José María; Hernandez, Jose A; Verma, Hemant K; Rubio, Luis M

    2016-04-29

    The extreme sensitivity of nitrogenase towards oxygen stands as a major barrier to engineer biological nitrogen fixation into cereal crops by direct nif gene transfer. Here, we use yeast as a model of eukaryotic cell and show that aerobically grown cells express active nitrogenase Fe protein when the NifH polypeptide is targeted to the mitochondrial matrix together with the NifM maturase. Co-expression of NifH and NifM with Nif-specific Fe-S cluster biosynthetic proteins NifU and NifS is not required for Fe protein activity, demonstrating NifH ability to incorporate endogenous mitochondrial Fe-S clusters. In contrast, expression of active Fe protein in the cytosol requires both anoxic growth conditions and co-expression of NifH and NifM with NifU and NifS. Our results show the convenience of using mitochondria to host nitrogenase components, thus providing instrumental technology for the grand challenge of engineering N2-fixing cereals.

  18. Plant Functional Diversity Can Be Independent of Species Diversity: Observations Based on the Impact of 4-Yrs of Nitrogen and Phosphorus Additions in an Alpine Meadow.

    Science.gov (United States)

    Li, Wei; Cheng, Ji-Min; Yu, Kai-Liang; Epstein, Howard E; Guo, Liang; Jing, Guang-Hua; Zhao, Jie; Du, Guo-Zhen

    2015-01-01

    Past studies have widely documented the decrease in species diversity in response to addition of nutrients, however functional diversity is often independent from species diversity. In this study, we conducted a field experiment to examine the effect of nitrogen and phosphorus fertilization ((NH4)2 HPO4) at 0, 15, 30 and 60 g m-2 yr-1 (F0, F15, F30 and F60) after 4 years of continuous fertilization on functional diversity and species diversity, and its relationship with productivity in an alpine meadow community on the Tibetan Plateau. To this purpose, three community-weighted mean trait values (specific leaf area, SLA; mature plant height, MPH; and seed size, SS) for 30 common species in each fertilization level were determined; three components of functional diversity (functional richness, FRic; functional evenness, FEve; and Rao's index of quadratic entropy, FRao) were quantified. Our results showed that: (i) species diversity sharply decreased, but functional diversity remained stable with fertilization; (ii) community-weighted mean traits (SLA and MPH) had a significant increase along the fertilization level; (iii) aboveground biomass was not correlated with functional diversity, but it was significantly correlated with species diversity and MPH. Our results suggest that decreases in species diversity due to fertilization do not result in corresponding changes in functional diversity. Functional identity of species may be more important than functional diversity in influencing aboveground productivity in this alpine meadow community, and our results also support the mass ratio hypothesis; that is, the traits of the dominant species influenced the community biomass production.

  19. Oxygen Transport Membranes

    Energy Technology Data Exchange (ETDEWEB)

    S. Bandopadhyay

    2008-08-30

    The focus of this research was to develop new membrane materials by synthesizing different compounds and determining their defect structures, crystallographic structures and electrical properties. In addition to measuring electrical conductivity, oxygen vacancy concentration was also evaluated using thermogravimetry, Neutron diffraction and Moessbauer Spectroscopy. The reducing conditions (CO{sub 2}/CO/H{sub 2} gas mixtures with steam) as encountered in a reactor environment can be expected to have significant influence on the mechanical properties of the oxides membranes. Various La based materials with and without Ti were selected as candidate membrane materials for OTM. The maximum electrical conductivity of LSF in air as a function of temperature was achieved at < 600 C and depends on the concentration of Sr (acceptor dopant). Oxygen occupancy in LSF was estimated using Neutron diffractometry and Moessbauer Spectroscopy by measuring magnetic moment changes depending on the Fe{sup 3+} and Fe{sup 4+} ratio. After extensive studies of candidate materials, lanthanum ferrites (LSF and LSFT) were selected as the favored materials for the oxygen transport membrane (OTM). LSF is a very good material for an OTM because of its high electronic and oxygen ionic conductivity if long term stability and mechanical strength are improved. LSFT not only exhibits p-type behavior in the high oxygen activity regime, but also has n-type conduction in reducing atmospheres. Higher concentrations of oxygen vacancies in the low oxygen activity regime may improve the performance of LSFT as an OTM. The hole concentration is related to the difference in the acceptor and donor concentration by the relation p = [Sr'{sub La}]-[Ti{sm_bullet}{sub Fe}]. The chemical formulation predicts that the hole concentration is, p = 0.8-0.45 or 0.35. Experimental measurements indicated that p is about {approx} 0.35. The activation energy of conduction is 0.2 eV which implies that LSCF conducts via the

  20. Oxygen Transport Membranes

    Energy Technology Data Exchange (ETDEWEB)

    S. Bandopadhyay

    2008-08-30

    The focus of this research was to develop new membrane materials by synthesizing different compounds and determining their defect structures, crystallographic structures and electrical properties. In addition to measuring electrical conductivity, oxygen vacancy concentration was also evaluated using thermogravimetry, Neutron diffraction and Moessbauer Spectroscopy. The reducing conditions (CO{sub 2}/CO/H{sub 2} gas mixtures with steam) as encountered in a reactor environment can be expected to have significant influence on the mechanical properties of the oxides membranes. Various La based materials with and without Ti were selected as candidate membrane materials for OTM. The maximum electrical conductivity of LSF in air as a function of temperature was achieved at < 600 C and depends on the concentration of Sr (acceptor dopant). Oxygen occupancy in LSF was estimated using Neutron diffractometry and Moessbauer Spectroscopy by measuring magnetic moment changes depending on the Fe{sup 3+} and Fe{sup 4+} ratio. After extensive studies of candidate materials, lanthanum ferrites (LSF and LSFT) were selected as the favored materials for the oxygen transport membrane (OTM). LSF is a very good material for an OTM because of its high electronic and oxygen ionic conductivity if long term stability and mechanical strength are improved. LSFT not only exhibits p-type behavior in the high oxygen activity regime, but also has n-type conduction in reducing atmospheres. Higher concentrations of oxygen vacancies in the low oxygen activity regime may improve the performance of LSFT as an OTM. The hole concentration is related to the difference in the acceptor and donor concentration by the relation p = [Sr'{sub La}]-[Ti{sm_bullet}{sub Fe}]. The chemical formulation predicts that the hole concentration is, p = 0.8-0.45 or 0.35. Experimental measurements indicated that p is about {approx} 0.35. The activation energy of conduction is 0.2 eV which implies that LSCF conducts via the

  1. Selective vulnerability of hippocampal sub-fields to oxygen-glucose deprivation is a function of animal age.

    Science.gov (United States)

    Lalonde, Crystal C; Mielke, John G

    2014-01-16

    For more than a century, the hippocampal sub-fields have been recognized as being differentially vulnerable to injury. While the cause remains unknown, the explanations generally considered have involved either vascular differences, or innate variability among cells. To examine the latter possibility, we prepared acute hippocampal slices from Sprague-Dawley rats, applied a brief period of oxygen-glucose deprivation (OGD; an in vitro model of ischemia), and assessed the viability of dissected sub-fields (CA1, CA3, dentate gyrus) by measuring mitochondrial 2,3,5-triphenyltetrazolium chloride (TTC) metabolism. In slices from young animals (15 weeks of age), post-OGD TTC metabolism was significantly reduced in the CA sub-fields relative to the dentate gyrus. Since previous studies found increasing age may worsen ischemic injury, we completed the same experiment using tissue from animals at 52 weeks of age, and found no differences in TTC metabolism across sub-fields. Given the established role of glutamate receptors in ischemic cell death, we examined two key subunit proteins (GluN1, found in all NMDA receptors, and GluA2, found in most AMPA receptors) across sub-fields and age to determine whether their expression complemented our viability data. We found that, relative to the CA1, the DG displayed greater GluN1 expression and lower GluA2 expression in both young and old animals. Our results confirm that regional vulnerability can be shown in a slice model, that the property is not intransigent, and that these features are likely not attributable to the expression pattern of key glutamate receptor subunits, but another molecular variable that changes over the lifespan.

  2. Hyperbaric Oxygen Prevents Cognitive Impairments in Mice Induced by D-Galactose by Improving Cholinergic and Anti-apoptotic Functions.

    Science.gov (United States)

    Chen, Chunxia; Huang, Luying; Nong, Zhihuan; Li, Yaoxuan; Chen, Wan; Huang, Jianping; Pan, Xiaorong; Wu, Guangwei; Lin, Yingzhong

    2017-01-11

    Our previous study demonstrated that hyperbaric oxygen (HBO) improved cognitive impairments mainly by regulating oxidative stress, inflammatory responses and aging-related gene expression. However, a method for preventing cognitive dysfunction has yet to be developed. In the present study, we explored the protective effects of HBO on the cholinergic system and apoptosis in D-galactose (D-gal)-treated mice. A model of aging was established via systemic intraperitoneal injection of D-gal daily for 8 weeks. HBO was administered during the last 2 weeks of D-gal injection. Our results showed that HBO in D-gal-treated mice significantly improved behavioral performance on the open field test and passive avoidance task. Studies on the potential mechanisms of this effect showed that HBO significantly reduced oxidative stress and blocked the nuclear factor-κB pathway. Moreover, HBO significantly increased the levels of choline acetyltransferase and acetylcholine and decreased the activity of acetylcholinesterase in the hippocampus. Furthermore, HBO markedly increased expression of the anti-apoptosis protein Bcl-2 and glial fibrillary acidic protein meanwhile decreased expression of the pro-apoptosis proteins Bax and caspase-3. Importantly, there was a significant reduction in expression of Aβ-related genes, such as amyloid precursor protein, β-site amyloid cleaving enzyme-1 and cathepsin B mRNA. These decreases were accompanied by significant increases in expression of neprilysin and insulin-degrading enzyme mRNA. Moreover, compared with the Vitamin E group, HBO combined with Vitamin E exhibited significant difference in part of the above mention parameters. These findings suggest that HBO may act as a neuroprotective agent in preventing cognitive impairments.

  3. Oxygen Therapy

    Science.gov (United States)

    ... oxygen at very high altitudes (like in the mountains or in an airplane) even if you do ... Med Vol 171. P1-P2, 2005 ATS Patient Education Series © 2016 American Thoracic Society www. thoracic. org ...

  4. Dissolved oxygen

    National Research Council Canada - National Science Library

    1981-01-01

    Dissolved oxygen concentrations in the waters of Botany Bay and Georges and Cooks Rivers vary mainly as a result of tidal water movements, algal and macrophytic growth and decay, and effects of storms...

  5. Enhanced MEA Performance for PEMFCs under Low Relative Humidity and Low Oxygen Content Conditions via Catalyst Functionalization

    Energy Technology Data Exchange (ETDEWEB)

    Xin, Le; Yang, Fan; Xie, Jian; Yang, Zhiwei; Kariuki, Nancy N.; Myers, Deborah J.; Peng, Jui-Kun; Wang, Xiaohua; Ahluwalia, Rajesh K.; Yu, Kang; Ferreira, Paulo J.; Bonastre, Alex Martinez; Fongalland, Dash; Sharman, Jonathan

    2017-01-01

    This work demonstrates that functionalizing annealed-Pt/Ketjen black EC300j (a-Pt/KB) and dealloyed-PtNi/Ketjen black EC300j (d-PtNi/KB) catalysts using p-phenyl sulfonic acid can effectively enhance performance in the membrane electrode assemblies (MEAs) of proton exchange membrane fuel cells (PEMFCs). The functionalization increased the size of both Pt and PtNi catalyst particles and resulted in the further leaching of Ni from the PtNi catalyst while promoting the formation of nanoporous PtNi nanoparticles. The size of the SO3H-Pt/KB and SO3H-PtNi/KB carbon-based aggregates decreased dramatically, leading to the formation of catalyst layers with narrower pore size distributions.MEA tests highlighted the benefits of the surface functionalization, in which the cells with SO3H-Pt/KB and SO3H-PtNi/KB cathode catalysts showed superior high current density performance under reduced RH conditions, in comparison with cells containing annealed Pt/KB (a-Pt/KB) and de-alloyed PtNi/KB (d-PtNi/KB) catalysts. The performance improvement was particularly evident when using reactant gases with low relative humidity, indicating that the hydrophilic functional groups on the carbon improved the water retention in the cathode catalyst layer. These results show a new avenue for enhancing catalyst performance for the next generation of catalytic materials for PEMFCs.

  6. Micro and nanopatterning of functional materials on flexible plastic substrates via site-selective surface modification using oxygen plasma

    NARCIS (Netherlands)

    George, A.; Stawski, T.M.; Unnikrishnan, S.; Veldhuis, S.A.; Elshof, J.E. ten

    2012-01-01

    A simple and cost effective methodology for large area micro and nanopatterning of a wide range of functional materials on flexible substrates is presented. A hydrophobic-hydrophilic chemical contrast was patterned on surfaces of various flexible plastic substrates using molds and shadow masks with

  7. Micro and nanopatterning of functional materials on flexible plastic substrates via site-selective surface modification using oxygen plasma

    NARCIS (Netherlands)

    George, A.; Stawski, T.M.; Unnikrishnan, S.; Veldhuis, S.A.; Elshof, J.E. ten

    2012-01-01

    A simple and cost effective methodology for large area micro and nanopatterning of a wide range of functional materials on flexible substrates is presented. A hydrophobic-hydrophilic chemical contrast was patterned on surfaces of various flexible plastic substrates using molds and shadow masks with

  8. Micro- and nanopatterning of functional materials on flexible plastic substrates via site-selective surface modification using oxygen plasma

    NARCIS (Netherlands)

    George, A.; Stawski, T.M.; Unnikrishnan, S.; Veldhuis, S.A.; Elshof, ten J.E.

    2012-01-01

    A simple and cost effective methodology for large area micro and nanopatterning of a wide range of functional materials on flexible substrates is presented. A hydrophobic-hydrophilic chemical contrast was patterned on surfaces of various flexible plastic substrates using molds and shadow masks with

  9. Effect of high intensity exercise on peak oxygen uptake and endothelial function in long-term heart transplant recipients

    DEFF Research Database (Denmark)

    Hermann, T S; Dall, C H; Goetze, J