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1

Promoted oxidation of phenol in aqueous solution using molecular oxygen at mild conditions  

SciTech Connect

Wet oxidation with molecular oxygen at mild conditions (temperature < 200 C, pressure {le} 2 MPa) is an economically attractive pretreatment step for non-biodegradable aqueous waste streams. In order to overcome the low reactivity of molecular oxygen towards organic molecules at these mild process conditions, an initiator was used in combination with ferrous ions in the acidic range. The promoted oxidation of phenol in aqueous solution was investigated in a 4 liters stirred autoclave. It was possible to degrade the phenol at temperatures as low as 100 C without observing an induction time. The remaining solution contained mainly acetic and formic acid and was well biodegradable. The oxidative behavior of the oxygen/phenol system could be explained using the well-known autoxidation mechanism for aliphatic molecules. 4-hydroperoxy-phenol is suggested as a key intermediate. Measured products are p-benzoquinone, hydroquinone, catechol, maleic, oxalic, pyruvic, formic, and acetic acid. Dimers could also be identified in sample extracts. A global pathway including all identified products is presented.

Vogel, F.; Harf, J.; Hug, A.; Rohr, P.R. von [Swiss Federal Inst. of Tech., Zuerich (Switzerland). Inst. of Process Engineering] [Swiss Federal Inst. of Tech., Zuerich (Switzerland). Inst. of Process Engineering

1999-05-01

2

Kinetics of organic transformations under mild aqueous conditions: implications for the origin of life and its metabolism  

NASA Technical Reports Server (NTRS)

The rates of thermal transformation of organic molecules containing carbon, hydrogen, and oxygen were systematically examined in order to identify the kinetic constraints that governed origin-of-life organic chemistry under mild aqueous conditions. Arrhenius plots of the kinetic data were used to estimate the reaction of half-lifes at 50 degrees C. This survey showed that hydrocarbons and organic substances containing a single oxygenated group were kinetically the most stable; whereas organic substances containing two oxygenated groups in which one group was an alpha- or beta-positioned carbonyl group were the most reactive. Compounds with an alpha- or beta-positioned carbonyl group (aldehyde or ketone) had rates of reaction that were up to 10(24)-times faster than rates of similar molecules lacking the carbonyl group. This survey of organic reactivity, together with estimates of the molecular containment properties of lipid vesicles and liquid spherules, indicates that an origins process in a small domain that used C,H,O-intermediates had to be catalytic and use the most reactive organic molecules to prevent escape of its reaction intermediates.

Weber, Arthur L.

2004-01-01

3

Kinetics of Organic Transformations Under Mild Aqueous Conditions: Implications for the Origin of Life and Its Metabolism  

NASA Technical Reports Server (NTRS)

The rates of thermal transformation of organic molecules containing carbon, hydrogen, and oxygen were systematically examined in order to identify the kinetic constraints that governed origin-of-life organic chemistry under mild aqueous conditions. Arrhenius plots of the kinetic data were used to estimate the reaction half-life at 50 C, and to reveal the effect of functional groups on reactivity. This survey showed that hydrocarbons and organic substances containing a single oxygenated group were kinetically the most stable (i. e. acetate decarboxylation half-life was l0(exp 18) years at 50 C); whereas, organic substances containing two oxygenated groups in which one group was a beta-positioned carbonyl group were the most reactive (i. e. acetoacetate decarboxylation half-life was l0(exp-2) years at 50 C). Of all functional groups the beta-positioned carbonyl group (aldehyde or ketone) was the strongest activating group, giving rates of reaction that were up to 10(exp 24)-times faster than rates of similar molecules lacking the beta-carbonyl group. From this knowledge of organic reactivity and the inherent constraints of autocatalytic processes, we concluded that an origins-of-life process based on autocatalytic transformation of C,H,O-substrates was constrained to using the most reactive organic molecules that contain alpha- or beta-carbonyl groups, since small autocatalytic domains of plausible catalytic power that used less reactive substrates could not carry out chemical transformations fast enough to prevent catastrophic efflux (escape) of reaction intermediates. Knowledge of the kinetics of organic transformations is useful, not only in constraining the chemistry of the earliest autocatalytic process related to the origin of life, but also in establishing the relative reactivity of organic molecules on the early Earth and other planets that may or may not be related to the origin of life.

Weber, Arthur L.

2003-01-01

4

Chemical Constraints Governing the Origin of Metabolism: The Thermodynamic Landscape of Carbon Group Transformations under Mild Aqueous Conditions  

NASA Astrophysics Data System (ADS)

The thermodynamics of organic chemistry under mild aqueous conditions was examined in order to begin to understand its influence on the structure and operation of metabolism and its antecedents. Free energies (?G) were estimated for four types of reactions of biochemical importance - carbon-carbon bond cleavage and synthesis, hydrogen transfer between carbon groups, dehydration of alcohol groups, and aldo-keto isomerization. The energies were calculated for mainly aliphatic groups composed of carbon, hydrogen, and oxygen. The energy values showed (1) that generally when carbon-carbon bond cleavage involves groups from different functional group classes (i.e., carboxylic acids, carbonyl groups, alcohols, and hydrocarbons), the transfer of the shared electron-pair to the more reduced carbon group is energetically favored over transfer to the more oxidized carbon group, and (2) that the energy of carbon-carbon bond transformation is primarily determined by the functional group class of the group that changes oxidation state in the reaction (i.e., the functional group class of the group that donates the shared electron-pair during cleavage, or that accepts the incipient shared electron-pair during synthesis). In contrast, the energy of hydrogen transfer between carbon groups is determined by the functional group class of both the hydrogen-donor group and the hydrogen-acceptor group. From these and other observations we concluded that the chemistry involved in the origin of metabolism (and to a lesser degree modern metabolism) was strongly constrained by (1) the limited redox-based transformation energy of organic substrates that is readily dissipated in a few energetically favorable irreversible reactions; (2) the energy dominance of a few transformation half-reactions that determines whether carbon-carbon bond transformation (cleavage or synthesis) is energetically favorable (?G < -3.5 kcal/mol), reversible (?G between +/-3.5 kcal/mol), or unfavorable (?G > +3.5 kcal/mol); and (3) the dependence of carbon group transformation energy on the functional group class (i.e., oxidation state) of participating groups that in turn is contingent on prior reactions and precursors in the synthetic pathway.

Weber, Arthur L.

2002-08-01

5

Chemical constraints governing the origin of metabolism: the thermodynamic landscape of carbon group transformations under mild aqueous conditions  

NASA Technical Reports Server (NTRS)

The thermodynamics of organic chemistry under mild aqueous conditions was examined in order to begin to understand its influence on the structure and operation of metabolism and its antecedents. Free energies (deltaG) were estimated for four types of reactions of biochemical importance carbon-carbon bond cleavage and synthesis, hydrogen transfer between carbon groups, dehydration of alcohol groups, and aldo-keto isomerization. The energies were calculated for mainly aliphatic groups composed of carbon, hydrogen, and oxygen. The energy values showed (1) that generally when carbon-carbon bond cleavage involves groups from different functional group classes (i.e., carboxylic acids, carbonyl groups, alcohols, and hydrocarbons), the transfer of the shared electron-pair to the more reduced carbon group is energetically favored over transfer to the more oxidized carbon group, and (2) that the energy of carbon-carbon bond transformation is primarily determined by the functional group class of the group that changes oxidation state in the reaction (i.e., the functional group class of the group that donates the shared electron-pair during cleavage, or that accepts the incipient shared electron-pair during synthesis). In contrast, the energy of hydrogen transfer between carbon groups is determined by the functional group class of both the hydrogen-donor group and the hydrogen-acceptor group. From these and other observations we concluded that the chemistry involved in the origin of metabolism (and to a lesser degree modern metabolism) was strongly constrained by (1) the limited redox-based transformation energy of organic substrates that is readily dissipated in a few energetically favorable irreversible reactions; (2) the energy dominance of a few transformation half-reactions that determines whether carbon-carbon bond transformation (cleavage or synthesis) is energetically favorable (deltaG < -3.5 kcal/mol), reversible (deltaG between +/-3.5 kcal/mol), or unfavorable (deltaG > +3.5 kcal/mol); and (3) the dependence of carbon group transformation energy on the functional group class (i.e., oxidation state) of participating groups that in turn is contingent on prior reactions and precursors in the synthetic pathway.

Weber, Arthur L.

2002-01-01

6

Aqueous hydrodechlorination of 4-chlorophenol over an Rh/reduced graphene oxide synthesized by a facile one-pot solvothermal process under mild conditions.  

PubMed

Reduced graphene oxide (RGO) supported rhodium nanoparticles (Rh-NPs/RGO) was synthesized through one-pot polyol co-reduction of graphene oxide (GO) and rhodium chloride. The catalytic property of Rh-NPs/RGO was investigated for the aqueous phase hydrodechlorination (HDC) of 4-chlorophenol (4-CP). A complete conversion of 4-CP into high valued products of cyclohexanone (selectivity: 23.2%) and cyclohexanol (selectivity: 76.8%) was successfully achieved at 303K and balloon hydrogen pressure in a short reaction time of 50min when 1.5g/L of 4-CP was introduced. By comparing with Rh-NPs deposited on the other supports, Rh-NPs/RGO delivered the highest initial rate (111.4mmol/gRhmin) for 4-CP HDC reaction under the identical conditions. The substantial catalytic activity of Rh-NPs/RGO can be ascribed to the small and uniform particle size of Rh (average particle size was 1.7±0.14nm) on the surface of the RGO sheets and an electron-deficient state of Rh in the catalyst as a result of the strong interaction between the active sites and the surface function groups of RGO. PMID:24762698

Ren, Yanlin; Fan, Guangyin; Wang, Chenyu

2014-06-15

7

Explosivity Conditions of Aqueous Solutions  

Microsoft Academic Search

This paper focuses on the conditions for explosive boiling and gas exsolution of aqueous solutions from a thermodynamic point\\u000a of view. Indeed, the kinetic nature of these processes, hence their explosivity, can be assessed by considering their relation\\u000a with the spinodal curve of these liquids. First, the concepts of mechanical and diffusion spinodals are briefly described,\\u000a which allows us to

R. Thiéry; L. Mercury

2009-01-01

8

Epoxidation of aromatic ?,?-unsaturated ketones using PVP–H 2O 2 under mild and heterogeneous conditions  

Microsoft Academic Search

?,?-Unsaturated ketones (chalcones) react with PVP–H2O2 in aqueous sodium hydroxide and 1,4-dioxane as solvent at 40°C to give the corresponding epoxides under mild and heterogeneous conditions in excellent yields.

Mohammad Ali Zolfigol; Gholamabbas Chehardoli; Morteza Shiri

2007-01-01

9

Solvolytic liquefaction of wood under mild conditions  

SciTech Connect

Conversion of wood to liquid products requires cleavage of bonds which crosslink the wood structure. This study examines a low-severity wood solubilization process utilizing a solvent medium consisting of a small amount of sulfuric acid and a potentially wood-derivable alcohol. In one half hour of reaction time at 250/sup 0/C under 15 psia starting nitrogen pressure, over 95% of the wood (maf) was rendered acetone-soluble. The product is a soft, black, bitumen-like solid at room temperature but readily softens at 140/sup 0/C. Between 25 and 50% of the original wood oxygen, depending on alcohol used, was removed as water. Approximately 2 to 17% of the alcohols were retained in the product. Gel permeation chromatography showed that the product's median molecular weight is around 300. Based on experimental and literature results, a mechanism for wood solubilization is proposed. This involves protonation of the etheric oxygen atoms, leading to subsequent bond scission to form carbonium ions which are stabilized by solvent alkoxylation. At severe conditions, polymerization and condensation reactions result in acetone-insoluble materials.

Yu, S.M.

1982-04-01

10

Corrosion inhibition by poly( N-ethylaniline) coatings of mild steel in aqueous acidic solutions  

Microsoft Academic Search

Poly(N-ethylaniline) (PNEA) coatings on mild steel have been electrodeposited from 0.1 to 0.5M aqueous oxalic acid solutions containing 0.1M N-ethylaniline (NEA) using potentiodynamic synthesis technique. The effect of oxalic acid concentration on the corrosion behavior of PNEA coated mild steel surfaces were investigated by DC polarization and electrochemical impedance spectroscopy (EIS) techniques in 0.1M HCl and 0.05M H2SO4 solutions. Corrosion

Aziz Ya?an; Nuran Özçiçek Pekmez; Attila Y?ld?z

2006-01-01

11

Electrosynthesis of adherent polyaniline films on iron and mild steel in aqueous oxalic acid medium  

Microsoft Academic Search

Polyaniline (PANi) films can be electrosynthesized by oxidation of aniline on iron and mild steel in a one-step process from an aqueous oxalic acid medium which passivates substrates. Homogeneous and strongly adherent films of controlled thickness can be deposited either in the potentiodynamic or galvanostatic modes. These films are characterized by IR, X-ray photoelectron spectroscopy (XPS), gel permeation chromatography (GPC)

J. L. Camalet; J. C. Lacroix; S. Aeiyach; K. Chane-Ching; P. C. Lacaze

1998-01-01

12

The rapid formation of functional monolayers on silicon under mild conditions.  

PubMed

We report on an exceedingly mild chemical functionalization of hydrogen-terminated Si(100) with unactivated and unprotected bifunctional ?,?-dialkynes. Monolayer formation occurs rapidly in the dark, and at room temperature, from dilute solutions of an aromatic-conjugated acetylene. The method addresses the poor reactivity of p-type substrates under mild conditions. We suggest the importance of several factors, including an optimal orientation for electron transfer between the adsorbate and the Si surface, conjugation of the acetylenic function with a ?-system, as well as the choice of a solvent system that favors electron transfer and screens Coulombic interactions between surface holes and electrons. The passivated Si(100) electrode is amenable to further functionalization and shown to be a viable model system for redox studies at non-oxide semiconductor electrodes in aqueous solutions. PMID:24647452

Ciampi, Simone; Luais, Erwann; James, Michael; Choudhury, Moinul H; Darwish, Nadim A; Gooding, J Justin

2014-05-01

13

Enabling antibacterial coating via bioinspired mineralization of nanostructured ZnO on fabrics under mild conditions.  

PubMed

Herein, we present an environmentally benign method capable of mineralization and deposition of nanomaterials to introduce antibacterial functionalities into cotton fabrics under mild conditions. Similar to the way in which many naturally occurring biominerals evolve around the living organism under ambient conditions, this technique enables flexible substrates like the cotton fabric to be coated with inorganic-based functional materials. Specifically, our strategy involves the use of long-chain polyamines known to be responsible in certain biomineralization processes, to nucleate, organize, and deposit nanostructured ZnO on cotton bandage in an aqueous solution under mild conditions of room temperature and neutral pH. The ZnO-coated cotton bandages as characterized by SEM, confocal micro-Raman spectroscopy, XRD, UV-DRS, and fluorescence microscopy demonstrate the importance of polyamine in generating a stable and uniform coating of spindle-shaped ZnO particles on individual threads of the fabric. As the coating process requires only mild conditions, it avoids any adverse effect on the thermal and mechanical properties of the substrate. Furthermore, the ZnO particles on cotton fabric show efficient antibacterial activity against both gram-positive and gram-negetive bacteria. Therefore, the developed polyamine mediated bioinspired coating method provides not only a facile and "green" synthesis for coating on flexible substrate but also the fabrication of antibacterial enabled materials for healthcare applications. PMID:23607588

Manna, Joydeb; Begum, Gousia; Kumar, K Pranay; Misra, Sunil; Rana, Rohit K

2013-05-22

14

Quinone methide phosphodiester alkylations under aqueous conditions.  

PubMed

A detailed analysis of the alkylation of phosphodiesters with a p-quinone methide under aqueous conditions has been accomplished. The relative rates of phosphodiester alkylation and hydrolysis have been examined by (1)H NMR analysis of the reaction of 2,6-dimethyl-p-quinone methide in a buffered diethyl phosphate/acetonitrile solution (1:9 v/v, pH 4.0). The rate of hydrolysis of the quinone methide was confirmed by UV analysis in 28.5% solutions of aqueous inorganic phosphate in acetonitrile at pH 4.0 and 7.0. Similarly, the rate of phosphodiester alkylations by the quinone methide was also confirmed by UV analysis in 28.5% solutions of aqueous dibenzyl, dibutyl, or diethyl phosphate in acetonitrile at pH 4.0 and 7.0. These kinetic studies further establish that the phosphodiester alkylation reactions are acid-catalyzed, second-order processes. The rate constant for phosphodiester alkylation was found to range from approximately 370-3700 times the rate constant of quinone methide hydrolysis with diethyl and dibenzyl phosphate, respectively (pH 4.0, 28.5% aqueous acetonitrile). PMID:11597232

Zhou, Q; Turnbull, K D

2001-10-19

15

Dialkylimidazolium ionic liquids hydrolyze cellulose under mild conditions.  

PubMed

The average molecular weight of cellulose derived from filter paper, poplar, and Avicel decreases by up to two orders of magnitude during typical mild dissolution protocols using ionic liquids (ILs). About an order of magnitude greater cellulose depolymerization rate during ionic liquid dissolution occurs in 1-butyl-3-methylimidazolium chloride (BmimCl) and 1-ethyl-3-methylimidazolium chloride (EmimCl) compared to 1-ethyl-3-methylimidazolium acetate (EmimOAc), and, unintuitively, greater IL purity results in greater cellulose depolymerization. The following data support the mechanism of cellulose hydrolysis to be acid-catalyzed: (i) increase in number of reducing ends following cellulose dissolution in IL; (ii) addition of N-methylimidazolium base suppresses cellulose depolymerization during dissolution in IL; (iii) small amounts of glucose and traces of hydroxymethyl furfural are present following cellulose dissolution in IL. The acid is presumably synthesized via IL decomposition to generate a carbene and proton, consistent with hypothesis derived from molecular modeling. Titration experiments conducted here measure the amount of acid synthesized to be in the 4000 ppm range for high-purity BmimCl IL during mild processing conditions for cellulose dissolution. This data is relevant for understanding the extent of IL decomposition during biomass dissolution. PMID:22550059

Gazit, Oz M; Katz, Alexander

2012-08-01

16

Catalytic hyrodechlorination of chlorophenols in aqueous solution under mild conditions  

Microsoft Academic Search

Hydrogen-saturated water or sodium borohydride were inefficient sources of active hydrogen species for the palladium-alumina accelerated hydrodechlorination (HDC) and subsequent hydrogenolysis of 4-chlorophenol (4-CP) or 2,6-dichlorophenol (2,6-DCP) in water at ambient temperature and pressure. By contrast, hydrogen gas in the presence of Pd0\\/Al2O3 accelerator mediated both hydrodechlorination and partial hydrogenolysis to cyclohexanone. 4-CP or pentachlorophenol (PCP) was converted quantitatively to

Heidi M Roy; Chien M Wai; Tao Yuan; Jun-Kyoung Kim; William D Marshall

2004-01-01

17

Thermally Stable Mesoporous Silica Spheres synthesized under Mild Conditions  

NASA Astrophysics Data System (ADS)

Thermally stable, mesoporous silica spheres were synthesized using a one-pot technique under mild conditions. As-calcined silica spheres were shown to be highly porous with surface areas greater than 1000 m^2/g and pore volumes on the order of 1 cc/g. Pore walls were found to be highly resistant to collapse as a consequence of thermal treatment at temperatures exceeding 750 C or hydrothermal treatment in boiling water at temperatures exceeding 100 C for over 100 hours. ^29Si-^1H cross polarization NMR data indicate that the silica is highly condensed at the surface providing rationale for the exceptional pore wall stability observed. The mesoporous silica spheres were synthesized from tetraethyl orthosilicate (TEOS) at room temperature and near-neutral pH using cysteamine and cetyltrimethylammonium bromide (CTAB) in a mixed water and ethanol system. Sphere size was shown to be tunable by altering the relative amounts of ethanol, CTAB, or TEOS. Sphere diameters ranging from 30 nm to 560 nm were observed. The preparation method and characterization of these highly condensed, thermally stable, mesoporous silica spheres for applications including sensing, catalysis, purification, and payload encapsulation is presented.

Ziegler, Christopher; You, Eunyoung; Watkins, James

2009-03-01

18

Palladium-Catalyzed Alkenylation of Ketone Enolates under Mild Conditions.  

PubMed

A protocol for a mild, catalytic, intermolecular alkenylation of ketone enolates has been developed using a Pd/Q-Phos catalyst. Efficient intermolecular coupling of a variety of ketones with alkenyl bromides was achieved with a slight excess of LiHMDS and temperatures down to 0 °C. PMID:25032503

Grigalunas, Michael; Ankner, Tobias; Norrby, Per-Ola; Wiest, Olaf; Helquist, Paul

2014-08-01

19

Sodium nitrite catalyzed aerobic oxidative deoximation under mild conditions.  

PubMed

A mild, simple process for the effective deoximation of a wide range of ketoximes and aldoximes has been developed, which utilizes available NaNO(2) as the catalyst and molecular oxygen as the green oxidant. Notably Amberlyst-15, which acts as the initiator of NaNO(2), can be reused without regeneration. This environmentally benign protocol could provide a valuable synthetic method for practical applications. PMID:21528915

Zhang, Guofu; Wen, Xin; Wang, Yong; Mo, Weimin; Ding, Chengrong

2011-06-01

20

Selective hydroxylation of methane by dioxiranes under mild conditions.  

PubMed

The direct conversion of methane to methanol at low temperatures was achieved selectively using dioxiranes 1a,b either in the isolated form or generated in situ from aqueous potassium caroate and the parent ketone at a pH close to neutrality. Results suggest that the more powerful dioxirane TFDO (1b) should be the oxidant of choice. PMID:21417459

Annese, Cosimo; D'Accolti, Lucia; Fusco, Caterina; Curci, Ruggero

2011-04-15

21

Prevention of mildly overweight children from development of more overweight condition  

Microsoft Academic Search

Background. A follow-up study has reported that not only highly obese but also mildly obese children are becoming heavier during the elementary school children. Then we determined the effect of programs for the screening and treatment of overweight elementary school children whether the programs prevented mildly overweight children from development of more overweight condition.Methods. Subjects were 40 overweight children who

Masao Yoshinaga; Koji Sameshima; Koichiro Miyata; Jun Hashiguchi; Masato Imamura

2004-01-01

22

Integration of advanced oxidation processes at mild conditions in wet scrubbers for odourous sulphur compounds treatment.  

PubMed

The effectiveness of different advanced oxidation processes on the treatment of a multicomponent aqueous solution containing ethyl mercaptan, dimethyl sulphide and dimethyl disulphide (0.5mgL(-1) of each sulphur compound) was investigated with the objective to assess which one is the most suitable treatment to be coupled in wet scrubbers used in odour treatment facilities. UV/H2O2, Fenton, photo-Fenton and ozone treatments were tested at mild conditions and the oxidation efficiency obtained was compared. The oxidation tests were carried out in magnetically stirred cylindrical quartz reactors using the same molar concentration of oxidants (hydrogen peroxide or ozone). The results show that ozone and photo-Fenton are the most efficient treatments, achieving up to 95% of sulphur compounds oxidation and a mineralisation degree around 70% in 10min. Furthermore, the total costs of the treatments taking into account the capital and operational costs were also estimated for a comparative purpose. The economic analysis revealed that the Fenton treatment is the most economical option to be integrated in a wet scrubber to remove volatile organic sulphur compounds, as long as there are no space constraints to install the required reactor volume. In the case of reactor volume limitation or retrofitting complexities, the ozone and photo-Fenton treatments should be considered as viable alternatives. PMID:24873715

Vega, Esther; Martin, Maria J; Gonzalez-Olmos, Rafael

2014-08-01

23

Dynamics of a photochromic spiropyran under aqueous conditions  

NASA Astrophysics Data System (ADS)

The dynamics of a water soluble spiropyran is investigated by means of femtosecond transient absorption spectroscopy in the visible and infrared spectral range revealing an ultrafast reversible switching behavior under aqueous conditions with a high fatigue resistance.

Kohl-Landgraf, J.; Braun, M.; Özçoban, C.; Goncalves, D. P. N.; Heckel, A.; Wachtveitl, J.

2013-03-01

24

Role of hydrogen promoters on corrosion and hydrogenation of mild steel in aqueous and methanolic hydrochloric acid solutions  

SciTech Connect

Corrosion and hydrogenation of mild steel (MS) in aqueous and methanolic solutions of hydrochloric acid (HCl) were studied using weight loss, electrochemical, and hydrogen estimation methods. The effects of some hydrogen-promoting species such as cathodic poisons (i.e., sodium arsenite (NaAsO{sub 2}), selenium dioxide (SeO{sub 2}), stannous chloride (SnCl{sub 2}), and mercuric chloride (HgCl{sub 2})) were investigated to understand their role on the dissolution and hydrogen absorption characteristics of MS in aqueous and methanolic HCl solutions. The dissolution rate of MS in methanolic solution of HCl was considerably higher than in the aqueous HCl solution, where as the hydrogen pickup values of the steel in methanolic solution were less than in the aqueous HCl solution. Addition of NaAsO{sub 2} lowered the dissolution rate and hydrogen pickup values in both solutions. The other poisons had specific effects on the dissolution rate and hydrogen pickup values.

Paty, B.B. [B.J.B. Coll., Bhubaneswar (India). Dept. of Chemistry; Singh, D.D.N. [National Metallurgical Lab., Jamshedpur (India); Das, C.R.

1995-07-01

25

Peroxidation of C-H Bonds Adjacent to an Amide Nitrogen Atom under Mild Conditions.  

PubMed

Under mild conditions, the oxidative functionalization of C-H bonds adjacent to an amide nitrogen atom was achieved. tert-Butylperoxyamido acetal was obtained in high yields and could be further converted into ?-substituted amides by treatment with Grignard reagents. PMID:24892854

Yu, Hui; Shen, Jie

2014-06-20

26

Borylation of Unactivated Aryl Chlorides under Mild Conditions by Using Diisopropylaminoborane as a Borylating Reagent.  

PubMed

The synthesis of arylboronic ester derivatives from aryl chlorides by using aryl(amino)boranes is described. Palladium-catalyzed coupling between aryl chlorides and diisopropylaminoborane leads to the formation of a C?B bond under mild conditions. A wide range of functional groups are tolerated, making this method particularly useful for the borylation of functionalized aromatics. PMID:24729439

Guerrand, Hélène D S; Marciasini, Ludovic D; Jousseaume, Mélissa; Vaultier, Michel; Pucheault, Mathieu

2014-05-01

27

Attenuation of Aqueous Benzene in Soils under Saturated Flow Conditions  

Microsoft Academic Search

The fate of aqueous benzene in subsurface was investigated in this study, focusing on the role of sorption and biodegradation on the benzene attenuation under dynamic flow conditions. Two sets of column tests were conducted in Plexiglass flow cells packed uniformly with sandy aquifer materials. The first set of the experiment was conducted with a step-type injection of benzene with

S.-B. Kim; D.-J. Kim; S.-T. Yun

2006-01-01

28

Thermal signature of fear conditioning in mild post traumatic stress disorder.  

PubMed

Fear conditioning has been proposed as an important factor involved in the etiology of posttraumatic stress disorder (PTSD). We examined fear processing in PTSD patients with mild symptoms and in individuals who did not develop symptoms (both groups consisting of victims of a bank robbery), through the study of fear-conditioned response. Conditioned responses were quantified by the skin conductance response (SCR) and the facial thermal response, the latter being measured by high-resolution functional thermal infrared (fIR) imaging. We found: (a) a change of the physiological parameters with respect to the baseline condition in both control subjects and PTSD patients during the conditioning phase; (b) the permanence of the conditioning effect in the maintenance phase in both control and PTSD patients; (c) patients and controls did differ for the variation across the phases of the physiological parameters rather than for their absolute values, showing that PTSD patients had a prolonged excitation and higher tonic component of autonomic activity. These results, although preliminary, indicate that the analysis of SCR and facial thermal response during the conditioning paradigm is a promising psychometric method of investigation, even in the case of low level of PTSD symptom severity. To the best of our knowledge, this study is the first attempt to discriminate between control subjects and PTSD patients with mild symptoms through infrared thermal imaging. It may suggest feasible approaches for diagnostic screening in the early phases of the disorder and in the assessment of preventive measures and therapies. PMID:24561216

Di Giacinto, A; Brunetti, M; Sepede, G; Ferretti, A; Merla, A

2014-04-25

29

A Facile Cu(I)-Catalyzed Oxidative Coupling of Anilines to Azo Compounds and Hydrazines with Diaziridinone under Mild Conditions  

PubMed Central

A mild and highly efficient Cu(I)-catalyzed oxidative coupling of anilines is described. Various primary and secondary anilines can be efficiently coupled under mild conditions to the corresponding azo compounds and hydrazines in high yields. This method provides a direct and practical access to these compounds, and is also amenable to gram scale with no special precautions to exclude air or moisture.

Zhu, Yingguang; Shi, Yian

2013-01-01

30

Existence of mild solutions for fractional evolution equations with mixed monotone nonlocal conditions  

NASA Astrophysics Data System (ADS)

In this paper, we are concerned with nonlocal problem for fractional evolution equations with mixed monotone nonlocal term of the form ^CDq_tu(t) + Au(t) = f(t, u(t), u(t)),quad t in J = [0, a],u(0) = g(u, u),. where E is an infinite-dimensional Banach space, {^CDq_t} is the Caputo fractional derivative of order {qin (0, 1)}, A : D(A) ? E ? E is a closed linear operator and -A generates a uniformly bounded C 0-semigroup T(t) (t ? 0) in E, {f in C(J× E × E, E)}, and g is appropriate continuous function so that it constitutes a nonlocal condition. Under a new concept of coupled lower and upper mild L-quasi-solutions, we construct a new monotone iterative method for nonlocal problem of fractional evolution equations with mixed monotone nonlocal term and obtain the existence of coupled extremal mild L-quasi-solutions and the mild solution between them. The results obtained generalize the recent conclusions on this topic. Finally, we present two applications to illustrate the feasibility of our abstract results.

Chen, Pengyu; Li, Yongxiang

2013-08-01

31

Heat-moisture treatment under mildly acidic conditions alters potato starch physicochemical properties and digestibility.  

PubMed

Potato starch was subjected to heat-moisture treatment (HMT; 120 °C, 3 h) under mildly acidic conditions (pH 5, 6, or 6.5 [control]) at moisture levels of 15, 20 or 25%. HMT starches exhibited significantly delayed pasting times and reduced overall paste viscosities, amylose leaching, and granular swelling characteristics relative to native starch, as well as enhanced levels of thermo-stable resistant starch (?24%). HMT appeared to alter/enhance short-range chain associations (FT-IR) within amorphous and/or crystalline regions of starch granules. However, the extent of physicochemical change and RS enhancement during HMT was most facilitated by a mildly acidic condition (pH 6) at higher treatment moisture levels (20 or 25%). These conditions promoted limited hydrolysis of amylopectin molecules, primarily at ?-(1?6) branch points, likely enhancing mobility and interaction of starch chains during HMT. Thus, a slightly acidic pH might reduce conditions and/or timeframe needed to impart physicochemical changes and reduced digestibility to potato starch. PMID:24053800

Kim, Jong-Yea; Huber, Kerry C

2013-11-01

32

Differential Response in Downstream Processing of CHO Cells Grown Under Mild Hypothermic Conditions  

PubMed Central

The manufacture of complex therapeutic proteins using mammalian cells is well established, with several strategies developed to improve productivity. The application of sustained mild hypothermic conditions during culture has been associated with increases in product titer and improved product quality. However, despite associated cell physiological effects, very few studies have investigated the impact on downstream processing (DSP). Characterization of cells grown under mild hypothermic conditions demonstrated that the stationary phase was prolonged by delaying the onset of apoptosis. This enabled cells to maintain viability for extended periods and increase volumetric productivity from 0.74 to 1.02 g L?1. However, host cell proteins, measured by ELISA, increased by ?50%, attributed to the extended time course and higher peak and harvest cell densities. The individual components making up this impurity, as determined by SELDI-TOF MS and 2D-PAGE, were shown to be largely comparable. Under mild hypothermic conditions, cells were less shear sensitive than those maintained at 37°C, enhancing the preliminary primary recovery step. Adaptive changes in membrane fluidity were further investigated by adopting a pronounced temperature shift immediately prior to primary recovery and the improvement observed suggests that such a strategy may be implementable when shear sensitivity is of concern. Early and late apoptotic cells were particularly susceptible to shear, at either temperature, even under the lowest shear rate investigated. These findings demonstrate the importance of considering the impact of cell culture strategies and cell physiology on DSP, by implementing a range of experimental methods for process characterization. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:688–696, 2013

Tait, Andrew S; Tarrant, Richard D R; Velez-Suberbie, M Lourdes; Spencer, Daniel I R; Bracewell, Daniel G

2013-01-01

33

Mild, aqueous, aerobic, catalytic oxidation of methane to methanol and acetaldehyde catalyzed by a supported bipyrimidinylplatinum-polyoxometalate hybrid compound.  

PubMed

We have demonstrated that a bipyrimidinylplatinum-polyoxometalate, [Pt(Mebipym)Cl2]+[H4PV2Mo10O40]-, supported on silica is an active catalyst for the aerobic oxidation of methane to methanol in water under mild reaction conditions. Further oxidation of methanol yields acetaldehyde. The presence of the polyoxometalate is presumed to allow the facile oxidation of a Pt(II) intermediate to a Pt(IV) intermediate and to aid in the addition of methane to the Pt catalytic center. PMID:15315423

Bar-Nahum, Itsik; Khenkin, Alexander M; Neumann, Ronny

2004-08-25

34

Preparation of amino-functionalized silica in aqueous conditions  

NASA Astrophysics Data System (ADS)

Silica particle surfaces were modified with 3-aminopropyltriethoxysilane (APTES) for the fabrication under mild conditions of amino-functionalized silica particles which can be applied in a number of processes, e.g. chromatography. Surface activation was carried out in water at natural pH and in toluene on non-preheated silica in order to compare the grafting efficiency in these two solvents. No successive thermal treatments were carried out after grafting. Grafting extents were then calculated using solid state TOC measurements. Grafting extents of APTES in water and anhydrous solvent were surprisingly found to be the same after a simple rinsing step (i.e. 2.10 ± 0.09 ?mol/m2). Thus, in our case, the use of anhydrous solvent is an unnecessary precaution if the silica is further used in water since equivalent grafting extents of APTES are obtained with a simple and eco-friendly grafting process.

Cuoq, Fabrice; Masion, Armand; Labille, Jérôme; Rose, Jérôme; Ziarelli, Fabio; Prelot, Benedicte; Bottero, Jean-Yves

2013-02-01

35

MICROWAVE-ASSISTED PREPARATION OF 1-BUTYL-3-METHYLIMIDAZOLIUM TETRACHLOROGALLATE AND ITS CATALYTIC USE IN ACETAL FORMATION UNDER MILD CONDITIONS  

EPA Science Inventory

1-Butyl-3-methylimidazolium tetrachlorogallate, [bmim][GaCl4], prepared via microwave-assisted protocol, is found to be an active catalyst for the efficient acetalization of aldehydes under mild conditions....

36

Degradation of textile dyes using immobilized lignin peroxidase-like metalloporphines under mild experimental conditions  

PubMed Central

Background Synthetic dyes represent a broad and heterogeneous class of durable pollutants, that are released in large amounts by the textile industry. The ability of two immobilized metalloporphines (structurally emulating the ligninolytic peroxidases) to bleach six chosen dyes (alizarin red S, phenosafranine, xylenol orange, methylene blue, methyl green, and methyl orange) was compared to enzymatic catalysts. To achieve a green and sustainable process, very mild conditions were chosen. Results IPS/MnTSPP was the most promising biomimetic catalyst as it was able to effectively and quickly bleach all tested dyes. Biomimetic catalysis was fully characterized: maximum activity was centered at neutral pH, in the absence of any organic solvent, using hydrogen peroxide as the oxidant. The immobilized metalloporphine kept a large part of its activity during multi-cycle use; however, well-known redox mediators were not able to increase its catalytic activity. IPS/MnTSPP was also more promising for use in industrial applications than its enzymatic counterparts (lignin peroxidase, laccase, manganese peroxidase, and horseradish peroxidase). Conclusions On the whole, the conditions were very mild (standard pressure, room temperature and neutral pH, using no organic solvents, and the most environmental-friendly oxidant) and a significant bleaching and partial mineralization of the dyes was achieved in approximately 1 h. Therefore, the process was consistent with large-scale applications. The biomimetic catalyst also had more promising features than the enzymatic catalysts.

2012-01-01

37

Autonomic, behavioral, and neural analyses of mild conditioned negative affect in marmosets.  

PubMed

Avoidance and alerting behaviors and accompanying physiological responses, including changes in heart rate (HR), are core components of negative emotion. Investigations into the neural mechanisms underlying the regulation and integration of these responses require animal models that simultaneously measure both the physiological and behavioral components of emotion. A primate model is of particular importance in view of the well developed prefrontal cortex of primates, and this region's critical role in emotion regulation and the etiology of affective disorders. Therefore, we have developed a simple aversive conditioning paradigm to assess, simultaneously, cardiovascular and behavioral responses in the marmoset (Callithrix jacchus). Validation of the paradigm was achieved by (1) comparing conditioned responses to a predictive cue with pseudoconditioned responses to a nonpredictive cue; (2) assessing the acquisition of conditioning following lesions of the amygdala, a region essential for associative learning in humans and rats; and (3) determining the contributions of the sympathetic and parasympathetic nervous system to the conditioned autonomic responses. Marmosets acquired conditioned HR and behavioral responses in the conditioned, but not the pseudoconditioned or amygdala lesioned groups. Conditioned HR accelerations were reduced by both parasympathetic and sympathetic blockade. Thus, a model of associative learning of mild negative emotion in the marmoset has been validated by psychological, neurological, and pharmacological investigation. Future studies will determine the role of the prefrontal cortex in the regulation of these negative emotional responses, to provide insights into the neuropathology of affective disorders. PMID:20364879

Mikheenko, Yevheniia; Man, Mei-See; Braesicke, Katrin; Johns, Moira E; Hill, Gemma; Agustín-Pavón, Carmen; Roberts, Angela C

2010-04-01

38

Local and global existence of mild solution to an impulsive fractional functional integro-differential equation with nonlocal condition  

NASA Astrophysics Data System (ADS)

This paper is concerned with the local and global existence of mild solution for an impulsive fractional functional integro differential equations with nonlocal condition. We establish a general framework to find the mild solutions for impulsive fractional integro-differential equations, which will provide an effective way to deal with such problems. The results are obtained by using the fixed point technique and solution operator on a complex Banach space.

Chauhan, Archana; Dabas, Jaydev

2014-04-01

39

Modification of neodymium-doped ZnO hybrid nanoparticles under mild hydrothermal conditions  

NASA Astrophysics Data System (ADS)

The morphology and particle size of neodymium-doped ZnO hybrid nanoparticles were tailored through fabrication under mild hydrothermal conditions (T = 150-250 °C, P = autogeneous, t = 18 h) for the first time using two surface modifiers: caprylic acid and n-butylamine. Characterization of these nanoparticles was carried out using powder XRD, FTIR, SEM, zeta-potential analysis and UV-vis spectroscopy. The results revealed that modification of ZnO nanoparticles using neodymium as a dopant and caprylic acid or n-butylamine as a surfactant could change the optical and physical properties of the surface-modified neodymium-doped ZnO hybrid nanoparticles. The work proved the efficiency of caprylic acid and n-butylamine as suitable surfactants for surface modification of neodymium-doped ZnO hybrid nanoparticles.

Shahmoradi, Behzad; Soga, K.; Ananda, S.; Somashekar, R.; Byrappa, K.

2010-07-01

40

Mild gasification of steam-conditioned bituminous coal in fluidized beds: Technical note  

SciTech Connect

A detailed systems analysis of a commercial-scale mild gasification process has been performed. The process includes (1) a conceptual design of the process, (2) mass and energy balances that were calculated with the use of the Advanced System for Process Engineering (ASPEN) process simulator, and (3) a detailed economic assessment that includes several sensitivity studies. In this conceptual study, 1 million tons per year, dry basis, of Pittsburgh No. 8 coal are conditioned with steam at 700/degree/F for 5 minutes in a fluidized-bed and devolatilized at 1000/degree/F for 3 minutes in a second fluidized-bed. Volatiles are condensed and liquid condensate and gas are separated. Liquid production is 340,000 tons per year (approximately 1,870,000 barrels per year) based on an increased liquid yield due to steam conditioning of 37 weight percent of dry, ash-free coal (DAF). This assumed yield is based on bench-scale experimental results for steam-conditioned coal (Graff 1987). Gas produced in the process is internally consumed for char heating and steam generation. Net char production is 466,000 ton/yr. 27 refs., 3 figs., 3 tabs.

Gessner, A.W.; Hand, T.J.; Klara, J.M.

1988-02-01

41

Synthesis of boron suboxide from boron and boric acid under mild pressure and temperature conditions  

SciTech Connect

Graphical abstract: Well-crystallized and icosahedral B{sub 6}O crystals were prepared by reacting boron and boric acid at milder reaction conditions (1 GPa and 1300 {sup o}C for 2 h) as compared to previous work.. Research highlights: {yields} Well-crystallized icosahedral B{sub 6}O was synthesized by reacting boric acid and boron. {yields} The synthesis conditions (1 GPa and 1300 {sup o}C for 2 h) are milder in comparison with previous work. {yields} The more practical synthesis method may make B{sub 6}O as a potential substitute for diamond in industry. -- Abstract: Boron suboxide (B{sub 6}O) was synthesized by reacting boron and boric acid (H{sub 3}BO{sub 3}) at pressures between 1 and 10 GPa, and at temperatures between 1300 and 1400 {sup o}C. The B{sub 6}O samples prepared were icosahedral with diameters ranging from 20 to 300 nm. Well-crystallized and icosahedral crystals with an average size of {approx}100 nm can be obtained at milder reaction conditions (1 GPa and 1300 {sup o}C for 2 h) as compared to previous work. The bulk B{sub 6}O sample was stable in air at 600 {sup o}C and then slowly oxidized up to 1000 {sup o}C. The relatively mild synthetic conditions developed in this study provide a more practical synthesis of B{sub 6}O, which may potentially be used as a substitute for diamond in industry as a new superhard material.

Jiao, Xiaopeng; Jin, Hua; Ding, Zhanhui; Yang, Bin; Lu, Fengguo; Zhao, Xudong [State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)] [State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Liu, Xiaoyang, E-mail: liuxy@jlu.edu.cn [State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)] [State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Peng, Liping, E-mail: pengliping64@yahoo.cn [The 1st Norman Bethune Hospital, Jilin University, 71 Xinmin Street, Changchun 130021 (China)] [The 1st Norman Bethune Hospital, Jilin University, 71 Xinmin Street, Changchun 130021 (China)

2011-05-15

42

Enzymatic formulation capable of degrading scrapie prion under mild digestion conditions.  

PubMed

The prion agent is notoriously resistant to common proteases and conventional sterilisation procedures. The current methods known to destroy prion infectivity such as incineration, alkaline and thermal hydrolysis are harsh, destructive, environmentally polluting and potentially hazardous, thus limit their applications for decontamination of delicate medical and laboratory devices, remediation of prion contaminated environment and for processing animal by-products including specified risk materials and carcases. Therefore, an environmentally friendly, non-destructive enzymatic degradation approach is highly desirable. A feather-degrading Bacillus licheniformis N22 keratinase has been isolated which degraded scrapie prion to undetectable level of PrP(Sc) signals as determined by Western Blot analysis. Prion infectivity was verified by ex vivo cell-based assay. An enzymatic formulation combining N22 keratinase and biosurfactant derived from Pseudomonas aeruginosa degraded PrP(Sc) at 65 °C in 10 min to undetectable level -. A time-course degradation analysis carried out at 50 °C over 2 h revealed the progressive attenuation of PrP(Sc) intensity. Test of residual infectivity by standard cell culture assay confirmed that the enzymatic formulation reduced PrP(Sc) infectivity to undetectable levels as compared to cells challenged with untreated standard scrapie sheep prion (SSBP/1) (p-value = 0.008 at 95% confidence interval). This novel enzymatic formulation has significant potential application for prion decontamination in various environmentally friendly systems under mild treatment conditions. PMID:23874511

Okoroma, Emeka A; Purchase, Diane; Garelick, Hemda; Morris, Roger; Neale, Michael H; Windl, Otto; Abiola, Oduola O

2013-01-01

43

Aerobic oxidation of formaldehyde mediated by a Ce-containing polyoxometalate under mild conditions.  

PubMed

An evaluation of over 50 polyoxometalates (POMs) identified the complex NaH3[SiW11Ce(IV)O39] (NaH3(1)) as a selective and effective catalyst for the aerobic oxidation of formaldehyde to formic acid under very mild (including ambient) conditions. 183W NMR, UV-vis, cyclic voltammetry, and potentiometric titration establish that the catalyst is a monomer (Cs symmetry), 1, in solution, while X-ray crystallography (a = 12.9455(15) A, b = 13.2257(16) A, c = 14.5288(17) A, alpha = 81.408(2) degrees , beta = 85.618(2) degrees , gamma = 80.726(2) degrees , P, Z = 1, R1 = 5.79% based on 17244 independent reflections) and IR establish it to be a dimer (Ci symmetry), 1(2), in the solid state. Several lines of evidence, including the parabolic kinetic order in 1, nonlinear Arrhenius plot, independence of the rate on O2 pressure, presence of titratable H2O2 and HCO3H intermediates, and inhibition by conventional radical scavengers, all indicate the O2-based oxidations proceed by complex homolytic chemistry (autoxidation and Haber-Weiss radical-chain processes) likely initiated by protonated 1. PMID:15679400

Kholdeeva, Oxana A; Timofeeva, Maria N; Maksimov, Gennadii M; Maksimovskaya, Raisa I; Neiwert, Wade A; Hill, Craig L

2005-02-01

44

A new strategy for the chemoselective sulfonamide N-alkylation of sulfonyl ureas under neutral and mild conditions  

Microsoft Academic Search

An efficient and chemoselective sulfonamide N-alkylation of sulfonyl ureas is described. The sulfonyl urea derivatives, prepared in situ by the addition of an amine to an arylsulfonyl isocyanate, are selectively alkylated in excellent yields under neutral and mild conditions by treatment with trialkylphosphite–dimethyl acetylenedicarboxylate at ambient temperature.

Mehdi Adib; Ehsan Sheikhi; Gita Sheikhi Moghaddam; Hamid Reza Bijanzadeh

2010-01-01

45

A Mild and Efficient Chemoselective Tetrahydropyranylation of Alcohols Using Bronsted Acidic Ionic Liquid as Catalyst Under Solvent-Free Conditions  

Microsoft Academic Search

A straightforward and efficient method for preparation of morpholinium bisulfate ([mroH] HSO4) as a novel acidic IL is reported. The application of this efficient and inexpensive acidic ionic liquid catalyst for tetrahydropyranylation of alcohols under mild and solvent-free conditions at room was investigated.

Abdol R. Hajipour; Zahra. Nasresfahani

2011-01-01

46

Mild and Efficient Chemoselective Tetrahydropyranylation of Alcohols Using Brønsted Acidic Ionic Liquid as Catalyst Under Solvent-Free Conditions  

Microsoft Academic Search

A straightforward and efficient method for preparation of morpholinium bisulfate ([mroH]HSO4) as a novel acidic ionic liquid is reported. The application of this efficient and inexpensive acidic ionic liquid catalyst for tetrahydropyranylation of alcohols under mild and solvent-free conditions at room was investigated.

Abdol R. Hajipour; Zahra Nasresfahani

2012-01-01

47

Pursuit Rotor Learning of Mildly Retarded Children under Supplementary Feedback Conditions.  

ERIC Educational Resources Information Center

The purpose of this study was to determine if performance and learning of mildly retarded children on a rotary pursuit task was facilitated by various types of supplementary, concurrent sensory feedback and if supplementary feedback presented during either correct or incorrect responding differentially affected motor learning. (Author/SJL)

Horgan, James S.

1980-01-01

48

Highly enantioselective monoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditions  

Microsoft Academic Search

The selective monoalkylation of glycine tert-butyl ester aldimine Schiff base 3 has been realized in high chemical yield with excellent enantioselectivity under mild liquid–liquid phase-transfer conditions by the use of binaphthyl-derived chiral quaternary ammonium bromides 7 and 8 as catalysts. This achievement demonstrates that 3 can be used as a cost-effective substrate for the preparation of optically active ?-alkyl-?-amino acid

Takashi Ooi; Yuichiro Arimura; Yukihiro Hiraiwa; Lin Ming Yuan; Taichi Kano; Toru Inoue; Jun Matsumoto; Keiji Maruoka

2006-01-01

49

Mild Rh(III)-catalyzed direct C-H bond arylation of (hetero)arenes with arylsilanes in aqueous media.  

PubMed

An efficient rhodium(III)-catalyzed C-H bond activation and further direct arylation of (hetero)arenes with organosilanes in aqueous media was developed. This reaction shows good substrate scope and excellent functional group compatibility and gives the products in good yields with excellent regioselectivity. PMID:24785121

Lu, Ming-Zhu; Lu, Ping; Xu, Yun-He; Loh, Teck-Peng

2014-05-16

50

Formation of Flavor Components by the Reaction of Amino Acid and Carbonyl Compounds in Mild Conditions  

Microsoft Academic Search

This work describe products of reactions between four R-dicarbonyl compounds (diacetyl, pentan- 2,3-dione, glyoxal, and methylglyoxal) or two R-hydroxy ketones, (acetoine and acetol) and amino acids present in wines. The results shows the formation of odorous products or strong-smelling additives resulting from the Maillard and Strecker reaction in a primarily aqueous medium, at low temperature and low pH (pH 3.5)

Laura Pripis-Nicolau; Gilles de Revel; Alain Bertrand; Alain Maujean

2000-01-01

51

Humoral immune response upon mild heat-shock conditions in Galleria mellonella larvae.  

PubMed

Larvae of Galleria mellonella exposed to mild heat-shock (38 degrees C) showed an enhanced humoral immune response after microbial infection in comparison to infected animals grown at 28 degrees C. This enhanced response was manifested by increased expression of antimicrobial peptide (AMP) genes leading to enhanced antimicrobial activity in the hemolymph. We found an increased level of Hsp90 and changes in the level of a 55kDa protein recognized by anti-Hsp90 antibodies in fat bodies of infected animals reared at 28 degrees C as well as in uninfected animals exposed to elevated temperature. Pre-treatment of animals with an inhibitor of Hsp90, 17-DMAG, prior to immunization resulted in increased expression of AMP genes encoding gallerimycin and cecropin at 38 degrees C. This observation was correlated with the changes in Hsp90 protein and increased level of 55kDa protein. Also G. mellonella larvae pre-treated with 17-DMAG and exposed to mild heat-shock for 30min showed an increased survival rate after infection with entomopathogenic bacteria Pseudomonas aeruginosa. We also show the effect of 17-DMAG on the phosphorylation state of ERK MAP kinase. We postulate that Hsp90 may play a significant role in converging pathways involved in the insect immune response and heat-shock. PMID:17631308

Wojda, Iwona; Jakubowicz, Teresa

2007-11-01

52

Oxygen Tension in the Aqueous Humor of Human Eyes under Different Oxygenation Conditions  

PubMed Central

Purpose To measure oxygen tension in the aqueous humor of human eyes under different oxygenation conditions. Methods This prospective comparative interventional case series consisted of two parts. In the first part, 120 consecutive patients scheduled for cataract surgery were randomized into group I (control group) in which surgery was performed under local anesthesia inhaling 21% oxygen; group II in whom general anesthesia using 50% oxygen was employed; and group III receiving general anesthesia with 100% oxygen. After aspirating 0.2 ml aqueous humor under sterile conditions, the aqueous sample and a simultaneously drawn arterial blood sample were immediately analyzed using a blood gas analyzer. In part II the same procedures were performed in 10 patients after fitting a contact lens and patching the eye for 20 minutes (group IV) and in 10 patients after transcorneal delivery of oxygen at a flow rate of 5 L/min (group V). Results Mean aqueous PO2 in groups I, II and III was 112.3±6.2, 141.1±20.4, and 170.1±27 mmHg, respectively (P values <0.001) and mean arterial PO2 was 85.7±7.9, 184.6±46, and379.1±75.9 mmHg, respectively (P values <0.001). Aqueous PO2 was 77.2±9.2 mmHg in group IV and 152.3±10.9 mmHg in group V (P values <0.001). There was a significant correlation between aqueous and blood PO2 (r=0.537, P<0.001). The contribution of atmospheric oxygen to aqueous PO2 was 23.7%. Conclusion Aqueous oxygen tension is mostly dependent on the systemic circulation and in part on the atmosphere. Increasing inspiratory oxygen and transcorneal oxygen delivery both increase aqueous PO2 levels.

Sharifipour, Farideh; Idani, Esmaeil; Zamani, Mitra; Helmi, Toktam; Cheraghian, Bahman

2013-01-01

53

Mild Cognitive Impairment  

MedlinePLUS

About Alzheimer's Disease: Mild Cognitive Impairment Mild cognitive impairment (MCI) is a condition in which people have memory or other ... as severe as those seen in people with Alzheimer’s disease. More older people with MCI, compared with those ...

54

Efficient and facile one pot carboxylation of multiwalled carbon nanotubes by using oxidation with ozone under mild conditions  

NASA Astrophysics Data System (ADS)

In this study, oxidation of carbon nanotubes with ozone in the presence of hydrogen peroxide was investigated. The reaction was performed under clean and mild conditions and oxidized products with high concentration of oxygenated groups were yielded. The reaction products were characterized with attenuated total reflectance (ATR), Raman spectroscopy, scanning electron microscopy (SEM), X-ray diffractometry (XRD), back titration, X-ray photoelectron spectroscopy (XPS) and the dispersion behavior of the oxidized multiwalled carbon nanotubes (MWCNTs) was also studied. The results confirmed the presence of high concentrations of oxidative groups on the carbon nanotubes (CNTs) treated by the method of the present work.

Naeimi, Hossein; Mohajeri, Ali; Moradi, Leila; Rashidi, Ali Morad

2009-11-01

55

Selective production of hemicellulose-derived carbohydrates from wheat straw using dilute HCl or FeCl3 solutions under mild conditions. X-ray and thermo-gravimetric analysis of the solid residues.  

PubMed

The present work explores the combined production of hemicellulose-derived carbohydrates and an upgraded solid residue from wheat straw using a dilute-acid pretreatment at mild temperature. Dilute aqueous HCl solutions were studied at temperatures of 100 and 120°C, and they were compared to dilute FeCl(3) under the same conditions. Comparable yields of soluble sugars and acetic acid were obtained, affording an almost complete removal of pentoses when using 200 mM aqueous solutions at 120°C. The solid residues of pretreatment were characterized showing a preserved crystallinity of the cellulose, and a almost complete removal of ash forming matter other than Si. Results showed upgraded characteristic of the residues for thermal conversion applications compared to the untreated wheat straw. PMID:21421304

Marcotullio, G; Krisanti, E; Giuntoli, J; de Jong, W

2011-05-01

56

Aqueous alteration of VHTR fuels particles under simulated geological conditions  

NASA Astrophysics Data System (ADS)

Very High Temperature Reactor (VHTR) fuels consist of the bistructural-isotropic (BISO) or tristructural-isotropic (TRISO)-coated particles embedded in a graphite matrix. Management of the spent fuel generated during VHTR operation would most likely be through deep geological disposal. In this framework we investigated the alteration of BISO (with pyrolytic carbon) and TRISO (with SiC) particles under geological conditions simulated by temperatures of 50 and 90 °C and in the presence of synthetic groundwater. Solid state (scanning electron microscopy (SEM), micro-Raman spectroscopy, electron probe microanalyses (EPMA) and X-ray photoelectron spectroscopy (XPS)) and solution analyses (ICP-MS, ionique chromatography (IC)) showed oxidation of both pyrolytic carbon and SiC at 90 °C. Under air this led to the formation of SiO2 and a clay-like Mg-silicate, while under reducing conditions (H2/N2 atmosphere) SiC and pyrolytic carbon were highly stable after a few months of alteration. At 50 °C, in the presence and absence of air, the alteration of the coatings was minor. In conclusion, due to their high stability in reducing conditions, HTR fuel disposal in reducing deep geological environments may constitute a viable solution for their long-term management.

Ait Chaou, Abdelouahed; Abdelouas, Abdesselam; Karakurt, Gökhan; Grambow, Bernd

2014-05-01

57

School based VHT beneficial many reasons. Firstly relatively mild conditions admission meaning even underperforming students given opportunity pursuing promising career. general subjects short-term training business placements  

EPA Pesticide Factsheets

Did you mean: School based VHT beneficial many reasons. Firstly relatively mild conditions admission meaning even underperforming students given opportunity pursuing promising career. general subjects short-term training business placements ?

58

Incidence of postconcussion symptoms in psychiatric diagnostic groups, mild traumatic brain injury, and comorbid conditions.  

PubMed

The constellation of physical, cognitive, and emotional symptoms, collectively known as postconcussion syndrome (PCS), is not uniquely associated with concussion, making the etiology of chronic postconcussion symptoms controversial. The current study compared percentages of individuals meeting symptom-based criteria for PCS in a population-based sample of veterans composed of subgroups with various psychiatric diagnoses, a history of mild traumatic brain injury (MTBI), and healthy controls. Participants were identified from 4462 randomly sampled male U.S. Army veterans who served during the Vietnam era. Only 32% of veterans with a history of MTBI met DSM-IV symptom criteria for PCS as compared to 40% of those diagnosed with post-traumatic stress disorder (PTSD), 50% with generalized anxiety disorder (GAD), 57% with major depressive disorder (MDD), and 91% with somatization disorder. Results were consistent with existing literature showing that the PCS symptoms are not unique to concussion, and also provide important base-rate information for neuropsychologists practicing in both clinical and personal injury forensic settings. PMID:22935025

Donnell, Alison J; Kim, Michelle S; Silva, Marc A; Vanderploeg, Rodney D

2012-01-01

59

Efficient conversion of brown grease produced by municipal wastewater treatment plant into biofuel using aluminium chloride hexahydrate under very mild conditions.  

PubMed

Wastes produced by oil/water separation at the wastewater treatment plant of Bari West (Southern Italy) were taken, characterized and converted. About 12% of this material was composed of greases, mainly made of free fatty acids (50%) and soaps (34%), and was easily separable by the aqueous phase through a hot centrifugation. After chemical activation of this fatty fraction, a direct esterification was carried out under very mild conditions (320K and atmospheric pressure), converting more than 90% of the original free fatty acids into the respective methyl esters in less than 4h, by using AlCl3·6H2O. The activation energy correlated to the use of this catalyst was also calculated (Eaest=43.9kJmol(-1)). The very low cost of the biodiesel produced (0.45€L(-1)) and the associated relevant specific energy (5.02MJ kgFAMEs(-1)) make such a process a really sustainable and effective example of valorization of a waste. PMID:24434702

Pastore, Carlo; Lopez, Antonio; Mascolo, Giuseppe

2014-03-01

60

Release of O-sulfate groups under mild acid hydrolysis conditions used for estimation of N-sulfate content.  

PubMed

The treatment of chondroitin sulfate isolated from cultured B16 mouse melanoma cells with 0.04 M HCl at 100 degrees C for 90 min released up to 45% of O-sulfate residues as free inorganic sulfate. In addition to the release of inorganic sulfate, extensive degradation of this polysaccharide as well as of cartilage chondroitin sulfate, pig rib cartilage proteoglycan, heparin and hyaluronic acid was also evident under these conditions. The above hydrolysis conditions are used for characterizing 35S-labeled heparan sulfates synthesized by cultured cells and to calculate ratio of N- and O-sulfates in these molecules. Our results suggest that caution is necessary in interpreting the results of mild acid hydrolysis of glycosaminoglycans. PMID:884153

Bhavanandan, V P; Breindel, D; Davidson, E A

1977-06-23

61

Synthesis of graphene-based Pt nanoparticles by a one-step in situ plasma approach under mild conditions  

SciTech Connect

Herein, a one-step in situ plasma approach to synthesize the highly dispersed Pt nanoparticles on graphene under mild conditions is reported. The graphene oxide (GO) was transformed into graphene and H{sub 2}PtCl{sub 6} was simultaneously transformed into Pt nanoparticles under argon plasma conditions. The synthesized graphene-based Pt nanoparticles were characterized by scanning electron microscopy, atomic force microscopy, x-ray diffraction, and Fourier transform infrared spectroscopy. The analysis showed that the Pt nanoparticles were deposited on graphene as a form of face-centered cubical structure and the oxygen groups on graphene oxide were partially removed. The results of x-ray photoelectron spectroscopy analysis further confirmed the results.

Wang Qi; Song Mingming; Chen Changlun; Wei Yu; Zuo Xiao; Wang Xiangke [Key Laboratory of Novel Thin Film Solar Cells, Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei 230031 (China)

2012-07-16

62

Ammonium sorption from aqueous solutions by the natural zeolite Transcarpathian clinoptilolite studied under dynamic conditions  

Microsoft Academic Search

The scope of this study is ammonium-ion uptake from synthetic aqueous solutions onto raw and pretreated forms of the natural zeolite Transcarpathian clinoptilolite under dynamic conditions. Hydrogen ions displaced exchangeable cations on the clinoptilolite in distilled water (sodium ions) and hydrochloric acid (sodium, potassium, and calcium ions) and destroyed the zeolite framework structure in the last case. Ammonium uptake onto

Myroslav Sprynskyy; Mariya Lebedynets; Artur P. Terzyk; Piotr Kowalczyk; Jacek Namie?nik; Bogus?aw Buszewski

2005-01-01

63

Single step signal group-imidazole labeling of organic phosphate groups under aqueous conditions  

DOEpatents

Compounds and methods for single step, covalent labeling of the phosphate group of an organic substance under aqueous conditions are described. The labeling compound includes any kind of detectable signal group covalently bound to an imidazole moiety, which can be imidazole or a substituted imidazole. A preferred labeling compound has the formula ##STR1##

Giese, Roger W. (Quincy, MA); Wang, Poguang (Medford, MA)

1996-01-01

64

Single step signal group-imidazole labeling of organic phosphate groups under aqueous conditions  

DOEpatents

Compounds and methods for single step, covalent labeling of the phosphate group of an organic substance under aqueous conditions are described. The labeling compound includes any kind of detectable signal group covalently bound to an imidazole moiety, which can be imidazole or a substituted imidazole. A preferred labeling compound has the formula shown in the accompanying diagram. 4 figs.

Giese, R.W.; Wang, P.

1996-04-30

65

Effects of Mass Transfer and Flow Conditions on SRB Corrosion of Mild Steel  

Microsoft Academic Search

Microbiologically Influenced Corrosion (MIC) is a growing problem in the oil and gas industry resulting in huge financial losses. Sulfate Reducing Bacteria (SRB) are often the culprits although many other microorganisms can also be directly or indirectly involved. From the bioprocess engineering angle, mass transfer and flow conditions are very important in SRB biofilm formation and MIC corrosion rates. Experiments

Tingyue Gu; Srdjan Nesic; Jie Wen; Kaili Zhao

2006-01-01

66

A New Biarylphosphine Ligand for the Pd-Catalyzed Synthesis of Diaryl Ethers Under Mild Conditions  

PubMed Central

A new bulky biarylphosphine ligand (L8) has been developed that allows the Pd-catalyzed C–O cross-coupling of a wide range of aryl halides and phenols under milder conditions than previously possible. A direct correlation between the size of the ligand substituents in the 2?, 4? and 6? positions of the non-phosphine containing ring and the reactivity of the derived catalyst system was observed. Specifically, the rate of coupling increased with the size of these substituents.

Salvi, Luca; Davis, Nicole R.; Ali, Siraj Z.; Buchwald, Stephen L.

2011-01-01

67

Cu(II)-catalyzed selective aerobic oxidation of alcohols under mild conditions.  

PubMed

Aerobic Alcohol Oxidation. An efficient four-component system consisting of acetamido-TEMPO/Cu(ClO4)2/TMDP/DABCO in DMSO has been developed for room-temperature aerobic alcohol oxidation. Under the optimal conditions, various alcohols could be converted into their corresponding aldehydes or ketones in good to excellent yields. The newly developed catalytic system could also be recycled and reused for three runs without any significant loss of catalytic activity. PMID:16930071

Jiang, Nan; Ragauskas, Arthur J

2006-09-01

68

Room-temperature Cannizzaro reaction under mild conditions facilitated by magnesium bromide ethyl etherate and triethylamine.  

PubMed

[reaction: see text] A room-temperature convenient Cannizzaro reaction prompted by magnesium bromide ethyl etherate and triethylamine is described for smooth conversion of aromatic aldehydes into their respective alcohols and carboxylic acids. The methodology is applicable to both inter- and intramolecular reactions and could be directed to obtain the carboxylic moiety in the form of an acid, an amide, or an ester compound depending on the selected reaction conditions or workup procedure. PMID:16354093

Abaee, M Saeed; Sharifi, Roholah; Mojtahedi, Mohammad M

2005-12-22

69

Rapid and effective oxidative pretreatment of woody biomass at mild reaction conditions and low oxidant loadings  

PubMed Central

Background One route for producing cellulosic biofuels is by the fermentation of lignocellulose-derived sugars generated from a pretreatment that can be effectively coupled with an enzymatic hydrolysis of the plant cell wall. While woody biomass exhibits a number of positive agronomic and logistical attributes, these feedstocks are significantly more recalcitrant to chemical pretreatments than herbaceous feedstocks, requiring higher chemical and energy inputs to achieve high sugar yields from enzymatic hydrolysis. We previously discovered that alkaline hydrogen peroxide (AHP) pretreatment catalyzed by copper(II) 2,2?-bipyridine complexes significantly improves subsequent enzymatic glucose and xylose release from hybrid poplar heartwood and sapwood relative to uncatalyzed AHP pretreatment at modest reaction conditions (room temperature and atmospheric pressure). In the present work, the reaction conditions for this catalyzed AHP pretreatment were investigated in more detail with the aim of better characterizing the relationship between pretreatment conditions and subsequent enzymatic sugar release. Results We found that for a wide range of pretreatment conditions, the catalyzed pretreatment resulted in significantly higher glucose and xylose enzymatic hydrolysis yields (as high as 80% for both glucose and xylose) relative to uncatalyzed pretreatment (up to 40% for glucose and 50% for xylose). We identified that the extent of improvement in glucan and xylan yield using this catalyzed pretreatment approach was a function of pretreatment conditions that included H2O2 loading on biomass, catalyst concentration, solids concentration, and pretreatment duration. Based on these results, several important improvements in pretreatment and hydrolysis conditions were identified that may have a positive economic impact for a process employing a catalyzed oxidative pretreatment. These improvements include identifying that: (1) substantially lower H2O2 loadings can be used that may result in up to a 50-65% decrease in H2O2 application (from 100 mg H2O2/g biomass to 35–50 mg/g) with only minor losses in glucose and xylose yield, (2) a 60% decrease in the catalyst concentration from 5.0 mM to 2.0 mM (corresponding to a catalyst loading of 25 ?mol/g biomass to 10 ?mol/g biomass) can be achieved without a subsequent loss in glucose yield, (3) an order of magnitude improvement in the time required for pretreatment (minutes versus hours or days) can be realized using the catalyzed pretreatment approach, and (4) enzyme dosage can be reduced to less than 30 mg protein/g glucan and potentially further with only minor losses in glucose and xylose yields. In addition, we established that the reaction rate is improved in both catalyzed and uncatalyzed AHP pretreatment by increased solids concentrations. Conclusions This work explored the relationship between reaction conditions impacting a catalyzed oxidative pretreatment of woody biomass and identified that significant decreases in the H2O2, catalyst, and enzyme loading on the biomass as well as decreases in the pretreatment time could be realized with only minor losses in the subsequent sugar released enzymatically. Together these changes would have positive implications for the economics of a process based on this pretreatment approach.

2013-01-01

70

Cannabinoid modulation of chronic mild stress-induced selective enhancement of trace fear conditioning in adolescent rats.  

PubMed

History of stress is considered a major risk factor for the development of major depression and posttraumatic stress disorder (PTSD). Elucidating the neurobiological mechanisms of Pavlovian fear conditioning may provide insight into the etiology of PTSD. In the current study, adolescent male Sprague-Dawley rats were exposed to 3 weeks of a chronic-mild-unpredictable stress (CMS) protocol. Immediately following the CMS, the animals were subjected to hippocampal-dependent (trace and contextual) and hippocampal-independent (delay) fear conditioning. CMS exposure enhanced trace freezing behavior compared to non-stress controls. This effect was not observed in contextual or delay conditioned animals. Given that the endocannabinoid system is negatively affected by CMS procedures, separate groups of stressed rats were administered the CB1 receptor agonist, ACEA (0.1 mg/kg), prior to trace fear conditioning or a memory-recall test. Regardless of administration time, ACEA significantly reduced freezing behavior in stressed animals. Furthermore, when administered during the first memory recall test, ACEA enhanced long-term extinction in both stress and non-stress groups. The results demonstrate that chronic unpredictable stress selectively enhances hippocampal-dependent episodic fear memories. Pathologies of the episodic memory and fear response may increase the susceptibility of developing PTSD. Reduction in fear responses via exogenous activation of the CB1 receptor suggests that a deficiency in the endocannabinoid system contributes to this pathology. PMID:23926242

Reich, Christian G; Iskander, Anthony N; Weiss, Michael S

2013-10-01

71

Multiple H2 occupancy of cages of clathrate hydrate under mild conditions.  

PubMed

Experiments were carried out by reacting H(2) gas with N(2) hydrate at a temperature of 243 K and a pressure of 15 MPa. The characterizations of the reaction products indicated that multiple H(2) molecules can be loaded into both large and small cages of structure II clathrate hydrates. The realization of multiple H(2) occupancy of hydrate cages under moderate conditions not only brings new insights into hydrogen clathrates but also refreshes the perspective of clathrate hydrates as hydrogen storage media. PMID:22587651

Lu, Hailong; Wang, Jianwei; Liu, Changling; Ratcliffe, Christopher I; Becker, Udo; Kumar, Rajnish; Ripmeester, John

2012-06-01

72

Hydrolysis of dilute acid-pretreated cellulose under mild hydrothermal conditions.  

PubMed

The hydrolysis of dilute acid-pretreated cellulose was investigated in a conventional oven and under microwave heating. Two acids - sulfuric and oxalic - were studied. For both hydrothermal conditions (oven and microwave) the resultant total organic carbon (TOC) values obtained by the hydrolysis of the cellulose pretreated with sulfuric acid were higher than those obtained by the hydrolysis of the cellulose pretreated with oxalic acid. However, the dicarboxylic acid exhibited higher hydrolytic efficiency towards glucose. The hydrolysis of cellulose was greatly promoted by microwave heating. The Rietveld method was applied to fit the X-ray patterns of the resultant cellulose after hydrolysis. Oxalic acid preferentially removed the amorphous region of the cellulose and left the crystalline region untouched. On the other hand, sulfuric acid treatment decreased the ordering of the cellulose by partially disrupting its crystalline structure. PMID:25037336

Chimentão, R J; Lorente, E; Gispert-Guirado, F; Medina, F; López, F

2014-10-13

73

Controlled release of volatiles under mild reaction conditions: from nature to everyday products.  

PubMed

Volatile organic compounds serve in nature as semiochemicals for communication between species, and are often used as flavors and fragrances in our everyday life. The quite limited longevity of olfactive perception has led to the development of pro-perfumes or pro-fragrances--ideally nonvolatile and odorless fragrance precursors which release the active volatiles by bond cleavage. Only a limited amount of reaction conditions, such as hydrolysis, temperature changes, as well as the action of light, oxygen, enzymes, or microorganisms, can be used to liberate the many different chemical functionalities. This Review describes the controlled chemical release of fragrances and discusses additional challenges such as precursor stability during product storage as well as some aspects concerning toxicity and biodegradability. As the same systems can be applied in different areas of research, the scope of this Review covers fragrance delivery as well as the controlled release of volatiles in general. PMID:17605134

Herrmann, Andreas

2007-01-01

74

Effects of mild TBI from repeated blast overpressure on the expression and extinction of conditioned fear in rats.  

PubMed

Mild traumatic brain injury (mTBI) and post-traumatic stress disorder (PTSD) are pressing medical issues for the Warfighter. Symptoms of mTBI can overlap with those of PTSD, suggesting the possibility of a causal or mediating role of mTBI in PTSD. To address whether mTBI can exacerbate the neurobiological processes associated with traumatic stress, we evaluated the impact of mTBI from a blast overpressure (BOP) on the expression of a conditioned fear. In the rat, conditioned fear models are used to evaluate the emotional conditioning processes that are known to become dysfunctional in PTSD. Rats were first trained on a variable interval (VI), food maintained, operant conditioning task that established a general measure of performance. Inescapable electric shock (IES) was paired with an audio-visual conditioned stimulus (CS) and followed 1day later by three daily exposures to BOP (75kPa). Subsequently, the CS alone was presented once every 7days for 2months, beginning 4days following the last BOP. The CS was presented during the VI sessions allowing a concurrent measure of performance. Treatment groups (n=10, each group) received IES+BOP, IES+sham-BOP, sham-IES+BOP or sham-IES+sham-BOP. As expected, pairing the CS with IES produced a robust conditioned fear that was quantified by a suppression of responding on the VI. BOP significantly decreased the expression of the conditioned fear. No systematic short- or long-term performance deficits were observed on the VI from BOP. These results show that mTBI from BOP can affect the expression of a conditioned fear and suggests that BOP caused a decrease in inhibitory behavioral control. Continued presentation of the CS produced progressively less response suppression in both fear conditioned treatments, consistent with extinction of the conditioned fear. Taken together, these results show that mTBI from BOP can affect the expression of a conditioned fear but not necessarily in a manner that increases the conditioned fear or extends the extinction process. PMID:24056195

Genovese, R F; Simmons, L P; Ahlers, S T; Maudlin-Jeronimo, E; Dave, J R; Boutte, A M

2013-12-19

75

First experimental determination of iron isotope fractionation between hematite and aqueous solution at hydrothermal conditions  

NASA Astrophysics Data System (ADS)

Although iron isotopes provide a new powerful tool for tracing a variety of geochemical processes, the unambiguous interpretation of iron isotope ratios in natural systems and the development of predictive theoretical models require accurate data on equilibrium isotope fractionation between fluids and minerals. We investigated Fe isotope fractionation between hematite (Fe 2O 3) and aqueous acidic NaCl fluids via hematite dissolution and precipitation experiments at temperatures from 200 to 450 °C and pressures from saturated vapor pressure ( Psat) to 600 bar. Precipitation experiments at 200 °C and Psat from aqueous solution, in which Fe aqueous speciation is dominated by ferric iron (Fe III) chloride complexes, show no detectable Fe isotope fractionation between hematite and fluid, ? 57Fe fluid-hematite = ? 57Fe fluid - ? 57Fe hematite = 0.01 ± 0.08‰ (2 × standard error, 2SE). In contrast, experiments at 300 °C and Psat, where ferrous iron chloride species (FeCl 2 and FeCl +) dominate in the fluid, yield significant fluid enrichment in the light isotope, with identical values of ? 57Fe fluid-hematite = -0.54 ± 0.15‰ (2SE) both for dissolution and precipitation runs. Hematite dissolution experiments at 450 °C and 600 bar, in which Fe speciation is also dominated by ferrous chloride species, yield ? 57Fe fluid-hematite values close to zero within errors, 0.15 ± 0.17‰ (2SE). In most experiments, chemical, redox, and isotopic equilibrium was attained, as shown by constancy over time of total dissolved Fe concentrations, aqueous Fe II and Fe III fractions, and Fe isotope ratios in solution, and identical ? 57Fe values from dissolution and precipitation runs. Our measured equilibrium ? 57Fe fluid-hematite values at different temperatures, fluid compositions and iron redox state are within the range of fractionations in the system fluid-hematite estimated using reported theoretical ?-factors for hematite and aqueous Fe species and the distribution of Fe aqueous complexes in solution. These theoretical predictions are however affected by large discrepancies among different studies, typically ±1‰ for the ? 57Fe Fe(aq)-hematite value at 200 °C. Our data may thus help to refine theoretical models for ?-factors of aqueous iron species. This study provides the first experimental calibration of Fe isotope fractionation in the system hematite-saline aqueous fluid at elevated temperatures; it demonstrates the importance of redox control on Fe isotope fractionation at hydrothermal conditions.

Saunier, Gaëlle; Pokrovski, Gleb S.; Poitrasson, Franck

2011-11-01

76

A mild pulsed electric field condition that improves acid tolerance, growth, and protease activity of Lactobacillus acidophilus LA-K and Lactobacillus delbrueckii subspecies bulgaricus LB-12.  

PubMed

Pulsed electric field (PEF) processing involves the application of pulses of voltage for less than 1 s to fluid products placed between 2 electrodes. The effect of mild PEF on beneficial characteristics of probiotic bacteria Lactobacillus acidophilus and Lactobacillus delbrueckii ssp. bulgaricus is not clearly understood. The objective of this study was to determine the influence of mild PEF conditions on acid tolerance, growth, and protease activity of Lb. acidophilus LA-K and Lactobacillus delbrueckii ssp. bulgaricus LB-12. A pilot plant PEF system (OSU-4M; The Ohio State University, Columbus) was used. The PEF treatments were positive square unipolar pulse width of 3 µs, pulse period of 0.5s, electric field strength of 1 kV/cm, delay time of 20 µs, flow rate of 60 mL/min, and 40.5°C PEF treatment temperature. Both Lb. acidophilus LA-K and Lb. bulgaricus LB-12 subjected to mild PEF conditions were acid tolerant until the end of the 120 min of incubation, unlike the Lb. bulgaricus control, which was not acid tolerant after 30 min. The mild PEF-treated Lb. acidophilus LA-K and Lb. bulgaricus LB-12 reached the logarithmic phase of growth an hour earlier than the control. Mild PEF conditions studied significantly improved acid tolerance, exponential growth, and protease activity of both Lb. acidophilus LA-K and Lb. bulgaricus LB-12 compared with the control. The mild PEF conditions studied can be recommended for pretreating cultures to enhance these desirable attributes. PMID:23587394

Najim, N; Aryana, Kayanush J

2013-06-01

77

Deep desulfurization by amphiphilic lanthanide-containing polyoxometalates in ionic-liquid emulsion systems under mild conditions.  

PubMed

Amphiphilic lanthanide-containing polyoxometalates (POMs) were prepared by surfactant encapsulation. Investigation of these lanthanide-containing POMs in oxidative desulfurization (ODS) showed that highly efficient deep desulfurization could be achieved in only 14 min with 100% conversion of dibenzothiophene under mild conditions by using (DDA)(9)LaW(10)/[omim]PF(6) (DDA=dimethyldioctadecylammonium, omim=1-octyl-3-methyl-imidazolium) in the presence of H(2) O(2) . Furthermore, deep desulfurization proceeds smoothly in model oil with an S content as low as 50 ppm. A scaled-up experiment in which the volume of model oil was increased from 5 to 1000 mL with S content of 1000 ppm indicated that about 99% sulfur removal can be achieved in 40 mins in an ionic-liquid emulsion system. To the best of our knowledge, the (DDA)(9)LaW(10)/[omim]PF(6) catalyst system with H(2)O(2) as oxidant is one of the most efficient desulfurization systems reported so far. PMID:23161825

Xu, Junhua; Zhao, Shen; Ji, Yuanchun; Song, Yu-Fei

2013-01-01

78

Gold nanoclusters confined in a supercage of Y zeolite for aerobic oxidation of HMF under mild conditions.  

PubMed

Au nanoclusters with an average size of approximately 1?nm size supported on HY zeolite exhibit a superior catalytic performance for the selective oxidation of 5-hydroxymethyl-2-furfural (HMF) into 2,5-furandicarboxylic acid (FDCA). It achieved >99?% yield of 2,5-furandicarboxylic acid in water under mild conditions (60?°C, 0.3?MPa oxygen), which is much higher than that of Au supported on metal oxides/hydroxide (TiO2 , CeO2 , and Mg(OH)2 ) and channel-type zeolites (ZSM-5 and H-MOR). Detailed characterizations, such as X-ray diffraction, transmission electron microscopy, N2 -physisorption, and H2 -temperature-programmed reduction (TPR), revealed that the Au nanoclusters are well encapsulated in the HY zeolite supercage, which is considered to restrict and avoid further growing of the Au nanoclusters into large particles. The acidic hydroxyl groups of the supercage were proven to be responsible for the formation and stabilization of the gold nanoclusters. Moreover, the interaction between the hydroxyl groups in the supercage and the Au nanoclusters leads to electronic modification of the Au nanoparticles, which is supposed to contribute to the high efficiency in the catalytic oxidation of HMF to FDCA. PMID:23999985

Cai, Jiaying; Ma, Hong; Zhang, Junjie; Song, Qi; Du, Zhongtian; Huang, Yizheng; Xu, Jie

2013-10-11

79

Tuning, via counter anions, the morphology and catalytic activity of CeO2 prepared under mild conditions.  

PubMed

Advanced synthetic methods under mild and controlled conditions for the synthesis of nanocrystals with specific shapes and exposed surfaces are very important for understanding the surface related properties and to explore their structure-property relationship for various potential applications. Here, we report the synthesis of highly uniform CeO(2) nanorods and nanoflowers in large scale using non-hydrothermal homogeneous precipitation method with urea as a precipitating agent and CTAB as a shape directing agent. Uniform microstructures of CeO(2) samples were selectively synthesized using chloride and nitrate as the counter anions. The samples were characterized by thermal analysis, X-ray diffraction, N(2) adsorption-desorption isotherms, SEM, TEM, UV-Vis-DRS, and Raman spectroscopy, and temperature programmed reduction as well as desorption methods. The results show that the physicochemical and optical properties of CeO(2) samples significantly differ with their surface microstructure and morphology. They also strongly influence the redox property, oxygen storage capacity, and surface acidity of the CeO(2) samples. The CeO(2) samples with different morphologies were tested for their soot oxidation activity. The CeO(2) sample with nanorod morphology was found to be more active due to larger CeO(2)/soot interface than the CeO(2) sample with nanoflower morphology. PMID:22014400

Meher, Sumanta Kumar; Rao, Gangavarapu Ranga

2012-05-01

80

Homogeneous ice freezing temperatures and ice nucleation rates of aqueous ammonium sulfate and aqueous levoglucosan particles for relevant atmospheric conditions.  

PubMed

Homogeneous ice nucleation from micrometre-sized aqueous (NH4)2SO4 and aqueous levoglucosan particles is studied employing the optical microscope technique. A new experimental method is introduced that allows us to control the initial water activity of the aqueous droplets. Homogeneous ice freezing temperatures and ice melting temperatures of these aqueous solution droplets, 10 to 80 microm in diameter, are determined. Homogeneous ice nucleation from aqueous (NH4)2SO4 particles 5-39 wt% in concentration and aqueous levoglucosan particles with initial water activities of 0.85-0.99 yield upper limits of the homogeneous ice nucleation rate coefficients of up to 1x10(10) cm(-3) s(-1). The experimentally derived homogeneous ice freezing temperatures and upper limits of the homogeneous ice nucleation rate coefficients are compared with corresponding predictions of the water-activity-based ice nucleation theory [T. Koop, B. P. Luo, A. Tsias and T. Peter, Nature, 2000, 406, 611]. It is found that the water-activity-based ice nucleation theory can capture the experimentally derived ice freezing temperatures and homogeneous ice nucleation rate coefficients of the aqueous (NH4)2SO4 and aqueous levoglucosan particles. However, the level of agreement between experimentally derived and predicted values, in particular for homogeneous ice nucleation rate coefficients, crucially depends on the extrapolation method to obtain water activities at corresponding freezing temperatures. It is suggested that the combination of experimentally derived ice freezing temperatures and homogeneous ice nucleation rate coefficients can serve as a better validation of the water-activity-based ice nucleation theory than when compared to the observation of homogeneous ice freezing temperatures alone. The atmospheric implications with regard to the application of the water-activity-based ice nucleation theory and derivation of maximum ice particle production rates are briefly discussed. PMID:19727513

Knopf, Daniel Alexander; Lopez, Miguel David

2009-09-28

81

Non-heme manganese catalysts for on-demand production of chlorine dioxide in water and under mild conditions.  

PubMed

Two non-heme manganese complexes are used in the catalytic formation of chlorine dioxide from chlorite under ambient temperature at pH 5.00. The catalysts afford up to 1000 turnovers per hour and remain highly active in subsequent additions of chlorite. Kinetic and spectroscopic studies revealed a Mn(III)(OH) species as the dominant form under catalytic conditions. A Mn(III)(?-O)Mn(IV) dinuclear species was observed by EPR spectroscopy, supporting the involvement of a putative Mn(IV)(O) species. First-order kinetic dependence on the manganese catalyst precludes the dinuclear species as the active form of the catalyst. Quantitative kinetic modeling enabled the deduction of a mechanism that accounts for all experimental observations. The chlorine dioxide producing cycle involves formation of a putative Mn(IV)(O), which undergoes PCET (proton coupled electron-transfer) reaction with chlorite to afford chlorine dioxide. The ClO2 product can be efficiently removed from the aqueous reaction mixture via purging with an inert gas, allowing for the preparation of pure chlorine dioxide for on-site use and further production of chlorine dioxide. PMID:24498903

Hicks, Scott D; Kim, Doyeon; Xiong, Silei; Medvedev, Grigori A; Caruthers, James; Hong, Seungwoo; Nam, Wonwoo; Abu-Omar, Mahdi M

2014-03-01

82

Enhanced dissolution of manganese oxide in ice compared to aqueous phase under illuminated and dark conditions.  

PubMed

Manganese is one of the common elements in the Earth's crust and an essential micronutrient for all living things. The reductive dissolution of particulate manganese oxide is a dominant process to enhance mobility and bioavailability of manganese for the use of living organisms. In this work, we investigated the reductive dissolution of manganese oxides trapped in ice (at -20 °C) under dark and light irradiation (visible: ? > 400 nm and UV: ? > 300 nm) in comparison with their counterparts in aqueous solution (at 25 °C). The reductive dissolution of synthetic MnO?, which took place slowly in aqueous solution, was significantly accelerated in ice phase both in the presence and absence of light: about 5 times more dissolution in ice phase than in liquid water after 6 h UV irradiation in the presence of formic acid. The enhanced dissolution in ice was observed under both UV and visible irradiation although the rate was much slower in the latter condition. The reductive dissolution rate of Mn(II)(aq) (under both irradiation and dark conditions) gradually increased with decreasing pH below 6 in both aqueous and ice phases, and the dissolution rates were consistently faster in ice under all tested conditions. The enhanced generation of Mn(II)(aq) in ice can be mainly explained in terms of freeze concentration of electron donors, protons, and MnO? in liquid-like ice grain boundaries. The outdoor solar experiment conducted in Arctic region (Ny-Ålesund, Svalbard, 78°55'N) also showed that the photoreductive dissolution of manganese oxide is enhanced in ice. The present results imply that the dissolution of natural minerals like manganese oxides can be enhanced in icy environments such as polar region, upper atmosphere, and frozen soil. PMID:23153016

Kim, Kitae; Yoon, Ho-Il; Choi, Wonyong

2012-12-18

83

Covalent attachment of mechanoresponsive luminescent micelles to glasses and polymers in aqueous conditions.  

PubMed

Covalent attachment of mechanoresponsive luminescent organic or organometallic compounds to other materials is a promising approach to develop a wide variety of mechanoresponsive luminescent materials. Here, we report covalently linkable mechanoresponsive micelles that change their photoluminescence from yellow to green in response to mechanical stimulation under aqueous conditions. These micelles are composed of a dumbbell-shaped amphiphilic pyrene derivative having amine groups at the peripheral positions of its dendrons. Using a well-established cross-linker, the micelles were covalently linked via their peripheral amine groups to the surface of glass beads, polylactic acid (PLA) beads, and living cells under aqueous conditions. Vortexing of glass beads bearing the micelles in a glass vial filled with water caused a photoluminescence color change from yellow to green. PLA beads bearing the micelles showed no change in photoluminescence color under the same conditions. We ascribe this result to the lower density and stiffness of the PLA beads, because the color of the PLA beads changed on vortexing in the presence of bare glass beads. HeLa cells and HL-60 cells bearing the micelles showed no obvious photoluminescence color change under vortexing. The structure, photophysical properties, and mechanism of photoluminescence color change of the micellar assemblies were examined. PMID:24571353

Sagara, Yoshimitsu; Komatsu, Toru; Ueno, Tasuku; Hanaoka, Kenjiro; Kato, Takashi; Nagano, Tetsuo

2014-03-19

84

Mechanics and mechanisms of surface damage in Al-Si alloys under ultra-mild wear conditions  

NASA Astrophysics Data System (ADS)

Al-Si alloys intended for use in engine components must operate under ultra-mild wear (UMW) conditions to fit an acceptable amount of wear during a typical vehicle life. This study simulated surface damage in a UMW regime on five chemically etched Al-Si alloy surfaces using a pin-on-disc tribometer at low loads (0.5-2.0 N) under boundary lubricated conditions. The five alloys contained 11 to 25 wt.% Si and differed in matrix hardness, silicon particle morphology, and size. The mechanisms leading to the UMW damage and the role that the matrix hardness and microstructure play on said mechanisms were studied. Quantitative measurement methods based on statistical analysis of particle height changes and material loss from elevated aluminum using a profilometer technique were developed and used to assess UMW. The Greenwood and Tripp's numerical model was adapted to analyze the contact that occurred between Al-Si alloys with silicon particles protruding above the aluminum and steel balls. The estimation of the real contact pressure applied to the silicon particles was used to rationalize the damage mechanisms. The UMW mechanisms consisted of (i) abrasive wear on the top of the silicon particle surfaces; (ii) sinking-in of the silicon particles; (iii) piling-up of the aluminium around sunken-in particles and (vi) wear of the aluminium by the counterface, which eventually led to the initiation of UMW-II. Increasing the size or areal density of silicon particles with small aspect ratios delayed the onset of UMW-II by providing resistance against the silicon particles sinking-in and the aluminum piling-up. The UMW wear rates, however, began to decrease after long sliding cycles once an oil residue layer supported by hardened ultra-fine subsurface grains formed on the deformed aluminium matrix. The layer formation depended on the microstructure and applied load. Overall experimental observations suggested that Al-11% Si with small silicon particles exhibited optimal long-term wear performance.

Chen, Ming

85

Zeolite-based organic–inorganic hybrid catalysts for phosgene-free and solvent-free synthesis of cyclic carbonates and carbamates at mild conditions utilizing CO 2  

Microsoft Academic Search

As-synthesized zeolite-beta exhibits high catalytic activity for the synthesis of cyclic carbonates and alkyl and aryl carbamates by a phosgene-free route, utilizing the greenhouse effect gas CO2. The reaction occurs with high yields of the desired products at mild conditions and without using any solvent or cocatalyst. Cyclic carbonates are synthesized by cycloaddition reaction of CO2 with oxiranes (epichlorohydrin, propene

R. Srivastava; D. Srinivas; P. Ratnasamy

2005-01-01

86

PdCl2 catalyzed efficient assembly of organic azides, CO, and alcohols under mild conditions: a direct approach to synthesize carbamates.  

PubMed

A simple and readily available PdCl2 catalyzed carbamate synthesis method via isocyanate generation and application in situ has been developed. This chemistry provides an efficient and practical approach to synthesize carbamates from simple organic azides, CO atmosphere and alcohols. The broad scope, mild and neutral conditions, and only N2 as the byproduct make this transformation very useful. Moreover, simple examples of modification of bioactive molecules and construction of macrocycles were achieved through this protocol. PMID:24577557

Ren, Long; Jiao, Ning

2014-04-11

87

Mild Combustion  

Microsoft Academic Search

The Mild Combustion is characterized by both an elevated temperature of reactants and low temperature increase in the combustion process. These features are the results of several technological demands coming from different application fields. This review paper aims to collect information which could be useful in understanding the fundamentals and applications of Mild Combustion. The information in this field are

Antonio Cavaliere; Mara de Joannon

2004-01-01

88

Aqueous Dissolution of Silver Iodide and Associated Iodine Release Under Reducing Conditions with Sulfide  

SciTech Connect

Aqueous dissolution tests of silver iodide (AgI) were performed in Na{sub 2}S solutions in order to evaluate, empirically, dissolution of AgI to release iodine under reducing conditions with sulfide. The results indicated that AgI dissolves to release iodine being controlled by mainly precipitation of Ag{sub 2}S. However, the dissolution of AgI can be depressed to proceed, and the thermodynamic equilibrium cannot be attained easily. Solid phase analysis for the reacted AgI suggested that a thin layer of solid silver forming at AgI surface may evolve to be protective against transportation of reactant species, which can lead to the depression in the dissolution of AgI. (authors)

Yaohiro Inagaki; Toshitaka Imamura; Kazuya Idemitsu; Tatsumi Arima [Kyushu University, Fukuoka, 819-0395 (Japan); Osamu Kato [Kobe Steel Inc., Kobe, 657-0845 (Japan); Hidekazu Asano; Tsutomu Nishimura [RWMC, Tokyo, 105-0001 (Japan)

2007-07-01

89

In-cloud processes of methacrolein under simulated conditions - Part 1: Aqueous phase photooxidation  

NASA Astrophysics Data System (ADS)

The photooxidation of methacrolein was studied in the aqueous phase under simulated cloud droplet conditions. The obtained rate constant of OH-oxidation of methacrolein at 6°C in unbuffered solutions was 5.8 (±0.9)×109 M-1 s-1. This kinetic study showed that the oxidation proceeds mainly by OH-addition on the C=C bond. This was confirmed by the mechanism established on the study of the reaction products (at 25°C in unbuffered solutions) where methylglyoxal, formaldehyde, hydroxyacetone and acetic acid/acetate were the main reaction products. An upper limit for the total carbon yield was estimated to range from 53 to 85%, indicating that some reaction products remain unidentified. A possible source of this mismatch is the formation of higher molecular weight compounds as primary reaction products which are presented in El Haddad et al. (2009) and Michaud et al. (2009).

Liu, Y.; El Haddad, I.; Scarfogliero, M.; Nieto-Gligorovski, L.; Temime-Roussel, B.; Quivet, E.; Marchand, N.; Picquet-Varrault, B.; Monod, A.

2009-03-01

90

Comparison of the flow properties of aqueous suspension corticosteroid nasal sprays under differing sampling conditions.  

PubMed

Many aqueous suspension corticosteroid nasal sprays become less viscous when shaken and sprayed, then return to a more viscous state after application. This time-dependent, reversible loss of viscosity under shear (e.g., shaking or spraying) can be quantified in the rheological property of thixotropy. The flow properties of 5 corticosteroid nasal sprays were measured over a range of shear rates. The formulations tested included Nasonex, Vancenase AQ, Nasacort AQ, Rhinocort Aqua, and Flonase. The yield stress values, as well as an estimate of thixotropy, were compared by using three different sampling techniques, including one that simulated patient use (shaking for 30 sec, spraying, and immediately transferring the sample to the rheometer). The rheological properties of all products indicated that when initially shaken and dispensed, they flowed more freely, followed by recovery of viscosity that would likely inhibit the suspensions from flowing out of the nasal cavity. Under all three tested conditions, Nasonex exhibited the highest yield stress, the largest apparent initial and final viscosities, and the highest apparent thixotropy. The study protocol that simulated patient-use conditions produced the following rank order of measured thixotropy: Nasonex > Flonase > Vancenase AQ > Rhinocort Aqua > Nasacort AQ. The thixotropy of Nasonex was 3.4 to 21.4 times greater and the final viscosity was 3.2 to 17.4 times greater than the values of the other tested products. PMID:14606664

Sharpe, S A; Sandweiss, V; Tuazon, J; Giordano, M; Witchey-Lakshmanan, L; Hart, J; Sequeira, J

2003-10-01

91

Oxidative degradation of organic pollutants in aqueous solution using zero valent copper under aerobic atmosphere condition.  

PubMed

Oxidative degradation of organic pollutants and its mechanism were investigated in aqueous solution using zero valent copper (ZVC) under aerobic atmosphere condition. Diethyl phthalate (DEP) was completely oxidized after 120min reaction by ZVC at initial pH 2.5 open to the air. DEP degradation followed the pseudo-first-order kinetics after the lag period, and the degradation rate of DEP increased gradually with the increase of ZVC dosage, and the decrease of initial pH from 5.8 to 2.0. ZVC required a shorter induction time and exhibited persistent oxidation capacity compared to that of zero valent iron and zero valent aluminium. The mechanism investigation showed that remarkable amount of Cu(+)/Cu(2+) and H2O2 were formed in ZVC acidic system, which was due to the corrosive dissolution of ZVC and the concurrent reduction of oxygen. The addition of tert-butanol completely inhibited the degradation of DEP and the addition of Fe(2+) greatly enhanced the degradation rate, which demonstrated that hydroxyl radical was mainly responsible for the degradation of DEP in ZVC acidic system under aerobic atmosphere condition, and the formation of hydroxyl radical was attributed to the Fenton-like reaction of in situ formed Cu(+) with H2O2. PMID:24857902

Wen, Gang; Wang, Sheng-Jun; Ma, Jun; Huang, Ting-Lin; Liu, Zheng-Qian; Zhao, Lei; Xu, Jin-Lan

2014-06-30

92

Dynamic nuclear polarization of 13C in aqueous solutions under ambient conditions.  

PubMed

The direct enhancement of the (13)C NMR signal of small molecules in solution through Overhauser-mediated dynamic nuclear polarization (DNP) has the potential to enable studies of systems where enhanced signal is needed but the current dissolution DNP approach is not suitable, for instance if the sample does not tolerate a freeze-thaw process or if continuous flow or rapid re-polarization of the molecules is desired. We present systematic studies of the (13)C DNP enhancement of (13)C-labeled small molecules in aqueous solution under ambient conditions, where we observe both dipolar and scalar-mediated enhancement. We show the role of the three-spin effects from enhanced protons on (13)C DNP through DNP experiments with and without broadband (1)H decoupling and by comparing DNP results with H(2)O and D(2)O. We conclude that the efficiency of (13)C Overhauser DNP in small molecules strongly depends on the distance of closest approach between the electron and (13)C nucleus, the presence of a scalar contribution to the coupling factor, and the magnitude of the three-spin effect due to adjacent polarized protons. The enhancement appears to depend less on the translational dynamics of the (13)C-labeled small molecules and radicals. PMID:19783462

Lingwood, Mark D; Han, Songi

2009-12-01

93

Dynamic nuclear polarization of 13C in aqueous solutions under ambient conditions  

NASA Astrophysics Data System (ADS)

The direct enhancement of the 13C NMR signal of small molecules in solution through Overhauser-mediated dynamic nuclear polarization (DNP) has the potential to enable studies of systems where enhanced signal is needed but the current dissolution DNP approach is not suitable, for instance if the sample does not tolerate a freeze-thaw process or if continuous flow or rapid re-polarization of the molecules is desired. We present systematic studies of the 13C DNP enhancement of 13C-labeled small molecules in aqueous solution under ambient conditions, where we observe both dipolar and scalar-mediated enhancement. We show the role of the three-spin effects from enhanced protons on 13C DNP through DNP experiments with and without broadband 1H decoupling and by comparing DNP results with H 2O and D 2O. We conclude that the efficiency of 13C Overhauser DNP in small molecules strongly depends on the distance of closest approach between the electron and 13C nucleus, the presence of a scalar contribution to the coupling factor, and the magnitude of the three-spin effect due to adjacent polarized protons. The enhancement appears to depend less on the translational dynamics of the 13C-labeled small molecules and radicals.

Lingwood, Mark D.; Han, Songi

2009-12-01

94

Dissolution of Columbia River Basalt Under Mildly Acidic Conditions as a Function of Temperature: Experimental Results Relevant to the Geological Sequestration of Carbon Dioxide  

SciTech Connect

Increasing attention is being focused on the rapid rise of carbon dioxide levels in the atmosphere, which many believe to be the major contributing factor to global climate change. Sequestering CO2 in deep geological formations has been proposed as a long-term solution to help stabilize CO2 levels. However, before such technology can be developed and implemented, a basic understanding of H2O-CO2 systems and the chemical interactions of these fluids with the host formation must be obtained. Important issues concerning mineral stability, reaction rates, and carbonate formation are all controlled or at least significantly impacted by the kinetics of rock-water reactions in mildly acidic, CO2-saturated solutions. Basalt has recently been identified as a potentially important host formation for geological sequestration. Dissolution kinetics of the Columbia River Basalt (CRB) were measured for a range of temperatures (25° to 90°C) under mildly acidic to neutral pH conditions using the single-pass flow-through test method. Under anaerobic conditions, the normalized dissolution rates for CRB decrease with increasing pH (3?pH?7) with a slope, ?, of -0.12 ± 0.02. An activation energy, Ea, has been estimated at 30.3 ± 2.4 kJ mol-1. Dissolution kinetics measurements like these are essential for modeling the rate at which the CO2 reacts with basalt and ultimately converted to carbonate minerals in situ.

Schaef, Herbert T.; McGrail, B. Peter

2009-05-01

95

CHEMICAL TRANSFORMATIONS USING NON-TRADITIONAL APPROACHES: MICROWAVE-ASSISTED GREENER SYNTHESES IN AQUEOUS MEDIA OR UNDER SOLVENT-FREE CONDITIONS  

EPA Science Inventory

Microwave (MW) irradiation in conjunction with water as reaction media has proven to be a 'greener' chemical approach for expeditious N -alkylation reactions of amines and hydrazines wherein the reactions under mildly basic conditions afford tertiary amines and double N...

96

Asian dust particles converted into aqueous droplets under remote marine atmospheric conditions  

PubMed Central

The chemical history of dust particles in the atmosphere is crucial for assessing their impact on both the Earth’s climate and ecosystem. So far, a number of studies have shown that, in the vicinity of strong anthropogenic emission sources, Ca-rich dust particles can be converted into aqueous droplets mainly by the reaction with gaseous HNO3 to form Ca(NO3)2. Here we show that other similar processes have the potential to be activated under typical remote marine atmospheric conditions. Based on field measurements at several sites in East Asia and thermodynamic predictions, we examined the possibility for the formation of two highly soluble calcium salts, Ca(NO3)2 and CaCl2, which can deliquesce at low relative humidity. According to the results, the conversion of insoluble CaCO3 to Ca(NO3)2 tends to be dominated over urban and industrialized areas of the Asian continent, where the concentrations of HNO3 exceed those of HCl ([HNO3/HCl] >  ? 1). In this regime, CaCl2 is hardly detected from dust particles. However, the generation of CaCl2 becomes detectable around the Japan Islands, where the concentrations of HCl are much higher than those of HNO3 ([HNO3/HCl] <  ? 0.3). We suggest that elevated concentrations of HCl in the remote marine boundary layer are sufficient to modify Ca-rich particles in dust storms and can play a more important role in forming a deliquescent layer on the particle surfaces as they are transported toward remote ocean regions.

Tobo, Yutaka; Zhang, Daizhou; Matsuki, Atsushi; Iwasaka, Yasunobu

2010-01-01

97

Formation of sulfur and nitrogen cross-linked macromolecules under aqueous conditions  

NASA Astrophysics Data System (ADS)

Polysulfides and ammonia are abundant in young depositional environments and play an important role in the formation of macromolecular structures such as protokerogen and humics. In this work, we study the co-incorporation of polysulfides and ammonia into simple carbonyl model compounds, octanal and trans 2-octenal, in order to study their effect on the formation of a cross-linked macromolecule and suggest a feasible mechanism. The reactions, performed in aqueous solutions at ambient temperature and pH ˜6 to 9, simulate formation of S and N cross-linked polymers in the natural environment. The complex S and N containing polymer was studied by 15N enrichment coupled to 2D NMR ( 1H, 13C, 15N) techniques and chemical degradation of S-S bonds followed by deuterium labeling and GC-MS analyses. In addition, molecular modeling techniques were used to provide theoretical interpretations and important insights at the molecular level. The results indicate that polysulfide out competes ammonia in the formation of Michael adducts while ammonia is equally competitive with polysulfides when the reaction is addition to the carbonyl position. The co-incorporation of ammonia and polysulfides into carbonyls rapidly forms N and S cross-linked polymers. The effects of ammonia and amines on the polymerization processes are by two means: (i) reaction with carbonyls through an imine functionality to form oligomers and polymers and (ii) catalysis of sulfur nucleophiles onto carbonyls by transfer of a proton which enhances the rate of polymerization. A similar catalytic effect is observed when glycine is used instead of ammonia. This mechanism is especially important under basic to neutral conditions like those that prevail in marine environments. The results show that ammonia and glycine or possibly other amino acids and/or peptides are intimately involved with sulfur nucleophiles throughout the polymerization processes that occur at low temperatures and thus are suggested as key reactants in diagenetic formation of protokerogen and humics.

Amrani, Alon; Turner, Jeffrey W.; Ma, Qisheng; Tang, Yongchun; Hatcher, Patrick G.

2007-09-01

98

Mutagenic effect by phenylalanine during gamma-irradiation of plasmid DNA in aqueous solution under oxic conditions.  

PubMed

Irradiation of DNA in aqueous solution or in cells with gamma-rays results in different mutational spectra, indicating that in both situations different patterns of DNA damages are induced. One of the causes for these different types of damages might be the formation of secondary, organic radicals, if cells are irradiated. Some organic compounds, including the amino acid phenylalanine, are well known to produce radicals during irradiation. Under oxic conditions these secondary radicals react with oxygen, thus forming peroxyl radicals which can be very harmful to DNA, and which may, therefore, induce DNA damage leading to mutations. This study examines the influence of the presence of phenylalanine during gamma-irradiation of DNA in aqueous solution under oxic conditions. The results indicate that the formation of phenylalanine radicals influences the types of induced mutations in the gamma-radiation-induced mutation spectrum. The most prominent difference is the increase in G:C to T:A transversions and the decrease in G:C to A:T transitions in the presence of phenylalanine. Further, it appears that the gamma-radiation-induced mutation spectrum after irradiation of DNA in aqueous solution is more comparable to the intracellular gamma-radiation-induced mutation spectrum in E. coli cells, if phenylalanine is present during irradiation. Therefore, these results suggest that the presence of phenylalanine during irradiation of DNA in aqueous solution gives a better impression of gamma-radiation-induced mutations in bacterial systems than water only. PMID:11035161

Reitsma-Wijker, C A; Slotman, B J; Lafleur, M V

2000-11-01

99

Mild Oxidative Stress Induces Redistribution of BACE1 in Non-Apoptotic Conditions and Promotes the Amyloidogenic Processing of Alzheimer's Disease Amyloid Precursor Protein  

PubMed Central

BACE1 is responsible for ?-secretase cleavage of the amyloid precursor protein (APP), which represents the first step in the production of amyloid ? (A?) peptides. Previous reports, by us and others, have indicated that the levels of BACE1 protein and activity are increased in the brain cortex of patients with Alzheimer’s disease (AD). The association between oxidative stress (OS) and AD has prompted investigations that support the potentiation of BACE1 expression and enzymatic activity by OS. Here, we have established conditions to analyse the effects of mild, non-lethal OS on BACE1 in primary neuronal cultures, independently from apoptotic mechanisms that were shown to impair BACE1 turnover. Six-hour treatment of mouse primary cortical cells with 10–40 µM hydrogen peroxide did not significantly compromise cell viability but it did produce mild oxidative stress (mOS), as shown by the increased levels of reactive radical species and activation of p38 stress kinase. The endogenous levels of BACE1 mRNA and protein were not significantly altered in these conditions, whereas a toxic H2O2 concentration (100 µM) caused an increase in BACE1 protein levels. Notably, mOS conditions resulted in increased levels of the BACE1 C-terminal cleavage product of APP, ?-CTF. Subcellular fractionation techniques showed that mOS caused a major rearrangement of BACE1 localization from light to denser fractions, resulting in an increased distribution of BACE1 in fractions containing APP and markers for trans-Golgi network and early endosomes. Collectively, these data demonstrate that mOS does not modify BACE1 expression but alters BACE1 subcellular compartmentalization to favour the amyloidogenic processing of APP, and thus offer new insight in the early molecular events of AD pathogenesis.

Tan, Jiang-Li; Li, Qiao-Xin; Ciccotosto, Giuseppe D.; Crouch, Peter John; Culvenor, Janetta Gladys; White, Anthony Robert; Evin, Genevieve

2013-01-01

100

Equilibrium hydrate formation conditions for hydrogen sulfide, carbon dioxide, and ethane in aqueous solutions of ethylene glycol and sodium chloride  

SciTech Connect

Natural gas components such as hydrogen sulfide, carbon dioxide, and ethane form gas hydrates of structure I under suitable temperature and pressure conditions. Information on such conditions is vital to the oil and gas industry in order to design and operate processing equipment and pipelines so that hydrate formation is avoided. Incipient equilibrium hydrate formation conditions for hydrogen sulfide, carbon dioxide, and ethane in aqueous solutions of ethylene glycol and sodium chloride were experimentally obtained in the temperature range 264--290 K and the pressure range 0.23--3.18 MPa. A variable-volume sapphire cell was used for the measurements.

Majumdar, A.; Mahmoodaghdam, E.; Bishnoi, P.R.

2000-02-01

101

Kinetics of carbonate dissolution in CO2-saturated aqueous system at reservoir conditions  

NASA Astrophysics Data System (ADS)

In recent years, carbon capture and storage (CCS) has emerged as a key technology for limiting anthropogenic CO2 emissions while allowing the continued utilisation of fossil fuels. The most promising geological storage sites are deep saline aquifers because the capacity, integrity and injection economics are most favourable, and the environmental impact can be minimal. Many rock-fluid chemical reactions are known to occur both during and after CO2 injection in saline aquifers. The importance of rock-fluid reactions in the (CO2 + H2O) system can be understood in terms of their impact on the integrity and stability of both the formation rocks and cap rocks. The chemical interactions between CO2-acidified brines and the reservoir minerals can influence the porosity and permeability of the formations, resulting in changes in the transport processes occurring during CO2 storage. Since carbonate minerals are abundant in sedimentary rocks, one of the requirements to safely implement CO2 storage in saline aquifers is to characterise the reactivity of carbonate minerals in aqueous solutions at reservoir conditions. In this work, we reported measurements of the intrinsic rate of carbonate dissolution in CO2-saturated water under high-temperature high-pressure reservoir conditions extending up to 373 K and 14 MPa. The rate of carbonate dissolution in CO2-free HCl(aq) was also measured at ambient pressure at temperatures up to 353 K. Various pure minerals and reservoir rocks were investigated in this study, including single-crystals of calcite and magnesite, and samples of dolomite, chalks and sandstones. A specially-designed batch reactor system, implementing the rotating disc technique, was used to obtain the intrinsic reaction rate at the solid/liquid interface, free of mass transfer effects. The effective area and mineralogy of the exposed surface was determined by a combination of surface characterisation techniques including XRD, SEM, EDX and optical microscopy. The results of the study indicate that the rotating disc technique can allow accurate measurement of the carbonate dissolution rate under surface-reaction-controlled conditions, and that the carbonate dissolution rate typically increases with the increase of temperature, CO2 partial pressure and solution acidity. The study shows that the dissolution of carbonate in CO2-free acidic solutions can be described as a first order heterogeneous reaction; however, this model is not sufficient to describe the reaction kinetics of carbonate minerals in the (CO2 + H2O) system, particularly for high reactivity carbonates, such as calcite, at reservoir conditions. For these systems, both pH and the activity of CO2(aq) influence the dissolution rate. Based on the experimental results, kinetic models have been developed and parameterised to describe the dissolution of different carbonate minerals. The results of this study should facilitate more rigorous modelling of mineral dissolution in deep saline aquifers used for CO2 storage. We gratefully acknowledge the funding of QCCSRC provided jointly by Qatar Petroleum, Shell, and the Qatar Science & Technology Park. Keywords: Carbon Dioxide, Carbonate, High Pressure, High Temperature, Reaction Kinetics.

Peng, Cheng; Crawshaw, John P.; Maitland, Geoffrey; Trusler, J. P. Martin

2014-05-01

102

Weathering and Dissolution Rates Among Pb Shot Pellets of Differing Elemental Compositions Exposed to Various Aqueous and Soil Conditions  

Microsoft Academic Search

The present study was performed to investigate the weathering and dissolution rates of Pb shot pellets differing in elemental\\u000a composition (Pb, Sb, and As) exposed under various aqueous and soil conditions using five commercial shot pellet preparations.\\u000a Upon immersion in distilled water, the dissolution rates of shot pellets, calculated from the difference in weight before\\u000a versus after immersion, decreased with

Takejiro Takamatsu; Tomoyoshi Murata; Masami K. Koshikawa; Mirai Watanabe

2010-01-01

103

An Aqueous Extract of the Dry Mycelium of Penicillium chrysogenum Induces Resistance in Several Crops under Controlled and Field Conditions  

Microsoft Academic Search

We have examined the effect of Pen, an aqueous extract of the dry mycelium of Penicillium chrysogenum, on plant–pathogen interactions. Pen controlled a broad range of pathogens on several crop plants under greenhouse and field\\u000a conditions. Pen protected grapevine from downy and powdery mildew (caused by Plasmopara viticola and Uncinula necator), tomato from early blight (caused by Phytophthora infestans), onion

Barbara Thuerig; Andres Binder; Thomas Boller; Urs Guyer; Sonia Jiménez; Christina Rentsch; Lucius Tamm

2006-01-01

104

Influence of processing and curing conditions on beads coated with an aqueous dispersion of cellulose acetate phthalate  

Microsoft Academic Search

The influence of fluidized-bed processing conditions, as well as curing parameters with and without humidity, on drug release from beads coated with cellulose acetate phthalate (CAP) aqueous dispersion was investigated. Theophylline beads prepared by extrusion–spheronization were coated with diethyl phthalate (DEP)-plasticized CAP dispersion (Aquacoat® CPD) using a Strea-1 fluidized-bed coater. The parameters investigated were plasticizer level, outlet temperature, spray rate

Robert O. Williams III; Jiping Liu

2000-01-01

105

Facile Synthesis of Tris(alkoxydimethylsilyl)methane Derivatives via Alcoholysis Under Open-Flask and Mild Conditions  

Microsoft Academic Search

The reactions between a variety of functionalized alcohols and tris(dimethylsilyl)methane, (HMe2Si)3CH, are described. Alcohols such as ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, triethylene glycol monomethyl ether, 2-chloroethanol, 1-octanol, benzyl alcohol, glycidol, and allyl alcohol were converted in the presence of Karstedt's catalyst into the corresponding tris(alkoxydimethylsilyl)methanes, (ROMe2Si)3CH, in a convenient one-pot operation under aerobic conditions. The appearance of

Kazem D. Safa; Elham Sharifi; Shahin Tofangdarzadeh; Akbar Hassanpour

2010-01-01

106

Interfacial properties of methane/aqueous VC-713 solution under hydrate formation conditions.  

PubMed

The interfacial tensions between methane and aqueous solutions of different contents of VC-713 (a terpolymer of N-vinylpyrrolidone, N-vinylcaprolactam, and dimethylamino-ethyl-methacrylate) were measured at different temperatures and pressures in the hydrate formation region. The surface adsorption free energies of methane were calculated accordingly in order to investigate the effect of this kinetic inhibitor on the nucleation of hydrate. The results show that the presence of VC-713 lowers the interfacial tension, increasing the concentration of methane on the surface of the aqueous phase, and thus promotes nucleation of hydrate at the gas/liquid interface. Additionally, the measured interfacial tension data suggest that VC-713 tends not to form micelles in water. Subsequently, the lateral growth rate of hydrate film on the surface of a methane bubble suspended in the aqueous phase was measured at different pressures to investigate the effect of VC-713 on the growth of hydrate. The results show that the lateral growth rate of hydrate film from aqueous VC-713 solution is much lower than that from pure water, demonstrating that VC-713 significantly inhibits the hydrate growth. The mechanism of the inhibition is also discussed. PMID:19447402

Peng, Bao-Zi; Sun, Chang-Yu; Liu, Peng; Liu, Yan-Tao; Chen, Jun; Chen, Guang-Jin

2009-08-15

107

Investigation of optimal conditions for zinc electrowinning from aqueous sulfuric acid electrolytes  

Microsoft Academic Search

Results are reported of an experimental investigation of the effects of aqueous zinc(II) and sulfuric acid concentrations\\u000a on current efficiencies and deposit morphologies of metallic zinc, aimed at designing a process for zinc recovery from solid\\u000a industrial wastes by leaching and electrodeposition. Voltammetry and chronopotentiometry of additive-free solutions of zinc(II)\\u000a sulfate and sulfuric acid were used to determine the zinc(II)

P. Guillaume; N. Leclerc; C. Boulanger; J. M. Lecuire; François Lapicque

2007-01-01

108

Non-interpenetrating transition metal diorganophosphate 2-dimensional rectangular grids from their 1-dimensional wires: structural transformations under mild conditions.  

PubMed

The manganese, cobalt, and cadmium complexes [M(dtbp)2]n (M = Mn (1) and Co 2) and [Cd(dtbp)2(H2O)]n (3) (dtbp = di-tert-butyl phosphate), which exist as one-dimensional molecular wires, transform to non-interpenetrating rectangular grids [M(dtbp)2(bpy)2.2H2O]n (M = Mn (4), Co (5), and Cd (6)) by the addition of 4,4-bipyridine (bpy) at room temperature. Products 4-6 have also been prepared by a room-temperature reaction or by solvothermal synthesis in methanol through a direct reaction between the metal acetate, di-tert-butyl phosphate, and 4,4'-bipyridine (bpy) in a 1:2:2 molar ratio. Single-crystal X-ray structure determination of 4-6 shows that these compounds are composed of octahedral transition metal ions woven into a two-dimensional grid structure with the help of bpy spacer ligands. The axial coordination sites at the metal are occupied by bulky unidentate dtbp ligands, which prevent any interpenetration of the individual grids. The change of reaction conditions from solvothermal to hydrothermal, for the attempted synthesis of a magnesium grid structure, however leads to the isolation of an organic phosphate [(H2bpy)(H2PO4)2] (7) and an inorganic phosphate [Mg(HPO4)(OH2)3] (8). Compound 7 can also be prepared quantitatively from a direct reaction between bpy and H3PO4. The new organic phosphate 7 is a unique example of a phosphate material with alternating layers of [H2bpy]2+ cations and [H2PO4]- anions that are held together by hydrogen bonds. Solid-state thermal decomposition of 4-6 produced the respective metaphosphate materials [M(PO3)2] (M = Mn (9), Co (10), and Cd (11)). All new metal-organic phosphates have been characterized by elemental analysis, thermal analysis (TGA, DTA, DSC), and IR and NMR spectroscopy. The metaphosphate ceramic materials were characterized by IR spectral and powder X-ray diffraction studies. PMID:16124811

Pothiraja, Ramasamy; Sathiyendiran, Malaichamy; Butcher, Ray J; Murugavel, Ramaswamy

2005-09-01

109

Mild balanoposthitis.  

PubMed Central

AIM--To identify and study cases of mild balanoposthitis (MBP) with penile pathology among patients observed at a dermatology clinic over an 18-month period. MATERIALS--The study included 321 patients with penile pathology. The term MBP was used to describe balanoposthitis of a localised, inflammatory nature with few, non-specific symptoms and a tendency to become chronic or recur. Two hundred and seventy had diseases clearly identifiable by clinical examination or laboratory tests; 51 cases were diagnosed as MBP and these patients had blood tests (to evaluate immune status) and microbiological examination; when these proved negative, a series of patch tests was also used. RESULTS--Of the 51 patients diagnosed as having MBP, the cause was ascertained in 34 cases (infection, mechanical trauma, contact irritation, contact allergy, etc.), whereas no specific aetiological factor was detected to explain the symptoms in the remaining 17 cases.

Fornasa, C V; Calabro, A; Miglietta, A; Tarantello, M; Biasinutto, C; Peserico, A

1994-01-01

110

The effect of precipitation conditions and aging upon characteristics of particles precipitated from aqueous solutions  

SciTech Connect

Precipitation of a dissolved species from aqueous solutions is one of the techniques used to grow particles with certain size or composition characteristics. Various factors affecting the particle properties for sparingly soluble substances are briefly discussed here, including homogeneous versus heterogeneous nucleation, the effect of relative supersaturation on the number of nuclei and their relative size, particle growth by way of Ostwald Ripening, the Ostwald Step Rule and nucleation of metastable phases, diffusion-controlled versus surface reaction-controlled growth, incorporation of dopants into the precipitate, and dendritic growth. 13 refs.

Rard, J.A.

1989-10-01

111

ROS initiated oxidation of dopamine under oxidative stress conditions in aqueous and lipidic environments.  

PubMed

Dopamine is known to be an efficient antioxidant and to protect neurocytes from oxidative stress by scavenging free radicals. In this work, we have carried out a systematic quantum chemistry and computational kinetics study on the reactivity of dopamine toward hydroxyl (•OH) and hydroperoxyl (•OOH) free radicals in aqueous and lipidic simulated biological environments, within the density functional theory framework. Rate constants and branching ratios for the different paths contributing to the overall reaction, at 298 K, are reported. For the reactivity of dopamine toward hydroxyl radicals, in water at physiological pH, the main mechanism of the reaction is proposed to be the sequential electron proton transfer (SEPT), whereas in the lipidic environment, hydrogen atom transfer (HAT) and radical adduct formation (RAF) pathways contribute almost equally to the total reaction rate. In both environments, dopamine reacts with hydroxyl radicals at a rate that is diffusion-controlled. Reaction with the hydroperoxyl radical is much slower and occurs only by abstraction of any of the phenolic hydrogens. The overall rate coefficients are predicted to be 2.23 × 10(5) and 8.16 × 10(5) M(-1) s(-1), in aqueous and lipidic environment, respectively, which makes dopamine a very good •OOH, and presumably •OOR, radical scavenger. PMID:21919526

Iuga, Cristina; Alvarez-Idaboy, J Raul; Vivier-Bunge, Annik

2011-10-27

112

Stimuli-Sensitive Hydrogel Based on N-Isopropylacrylamide and Itaconic Acid for Entrapment and Controlled Release of Candida rugosa Lipase under Mild Conditions  

PubMed Central

Stimuli responsive pH- and temperature-sensitive hydrogel drug delivery systems, as those based on N-isopropylacrylamide (NiPAAm) and itaconic acid (IA), have been attracting much of the attention of the scientific community nowadays, especially in the field of drug release. By adjusting comonomer composition, the matrix is enabled to protect the incorporated protein in the highly acidic environment of upper gastrointestinal tract and deliver it in the neutral or slightly basic region of the lower intestine. The protein/poly(NiPAAm-co-IA) hydrogels were synthetized by free radical crosslinking copolymerization and were characterized concerning their swelling capability, mechanical properties, and morphology. The pore structure and sizes up to 1.90?nm allowed good entrapment of lipase molecules. Model protein, lipase from Candida rugosa, was entrapped within hydrogels upon mild conditions that provided its protection from harmful environmental influences. The efficiency of the lipase entrapment reached 96.7%, and was dependent on the initial concentration of lipase solution. The swelling of the obtained hydrogels in simulated pH and temperature of gastrointestinal tract, the lipase entrapment efficiency, and its release profiles from hydrogels were investigated as well.

Milasinovic, Nikola; Knezevic-Jugovic, Zorica; Milosavljevic, Nedeljko; Lucic Skoric, Marija; Filipovic, Jovanka; Kalagasidis Krusic, Melina

2014-01-01

113

Composition and freezing of aqueous H2SO4/HNO3 solutions under polar stratospheric conditions  

NASA Technical Reports Server (NTRS)

The results of laboratory investigations of the freezing behavior of aqueous acid solutions indicate that in the stratosphere H2SO/H2O aerosol droplets would not freeze at temperatures above the ice frost point in the absence of HNO3; however, in the presence of typical levels of HNO3 liquid sulfuric acid aerosols take up significant amounts of HNO3 and H2O vapors and freeze much more readily. This is a consequence of the very rapid change in composition of the liquid droplets as the temperature drops to within two to three degrees of the equilibrium temperature at which HNO3 and H2O vapors would co-condense to form a liquid solution. In the high latitude stratosphere this HNO3/H2O 'dew point' is typically around 192-194 K at 100 mbar.

Beyer, K. D.; Seago, S. W.; Chang, H. Y.; Molina, M. J.

1994-01-01

114

Oxidation of 1,4-dichloro-2-butene by aqueous sodium hypochlorite under phase transfer conditions  

SciTech Connect

In the industrial process for the production of chloroprene from butadiene, the problem of reducing the organic impurities in the waste water to 2000 mg/liter has not yet been solved. A method has been patented for the oxidation of organic compounds by sodium hypochlorite at high temperatures and high pressure but this method is limited by the oxidation of soluble organic compounds. The oxidation of 1,4-dichloro-2-butene by aqueous sodium hypochlorite was studied. A sharp increase in the reaction rate was found in the presence of phase transfer catalysts and surfactants. The involvement of oxygen as a cooxiant and the effect of surfactants on the absorption of atmospheric oxygen by the reaction system were demonstrated.

Grigoryan, G.S.; Karoyan, I.L.; Malkhasyan, A.Ts.; Martirosyan, G.T.; Artamkina, G.A.; Beletskaya, I.P.

1987-11-10

115

Modeling of UO{sub 2} aqueous dissolution over a wide range of conditions  

SciTech Connect

Previously it was not possible to predict reliably the rate at which spent fuel would react with groundwater because of conflicting data in the literature. The dissolution of the UO{sub 2} spent fuel matrix is a necessary step for aqueous release of radioactive fission products. Statistical experimental design was used to plan a set of UO{sub 2} dissolution experiments to examine systematically the effects of temperature (25--75C), dissolved oxygen (0.002--0.2 atm overpressure), pH (8--10) and carbonate (2-200{times}10{sup {minus}4} molar) concentrations on UO{sub 2} dissolution. The average uranium dissolution rate was 4.3 mg/m{sub 2}/day. The regression fit of the data indicate an Arrhenius type activation energy of 8750 cal/mol and a half-power dependence on dissolved oxygen in the simulated groundwater.

Steward, S.A.; Weed, H.C.

1993-11-01

116

Mizoroki-heck cross-coupling reactions catalyzed by dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium under mild reaction conditions.  

PubMed

Dichloro-bis(aminophosphine) complexes of palladium with the general formula of [(P{(NC5H10)3-n(C6H11)n})2Pd(Cl)2] (where n = 0-2), belong to a new family of easy accessible, very cheap, and air stable, but highly active and universally applicable C-C cross-coupling catalysts with an excellent functional group tolerance. Dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium [(P(NC5H10)3)2Pd(Cl)2] (1), the least stable complex within this series towards protons; e.g. in the form of water, allows an eased nanoparticle formation and hence, proved to be the most active Heck catalyst within this series at 100 °C and is a very rare example of an effective and versatile catalyst system that efficiently operates under mild reaction conditions. Rapid and complete catalyst degradation under work-up conditions into phosphonates, piperidinium salts and other, palladium-containing decomposition products assure an easy separation of the coupling products from catalyst and ligands. The facile, cheap, and rapid synthesis of 1,1',1"-(phosphinetriyl)tripiperidine and 1 respectively, the simple and convenient use as well as its excellent catalytic performance in the Heck reaction at 100 °C make 1 to one of the most attractive and greenest Heck catalysts available. We provide here the visualized protocols for the ligand and catalyst syntheses as well as the reaction protocol for Heck reactions performed at 10 mmol scale at 100 °C and show that this catalyst is suitable for its use in organic syntheses. PMID:24686532

Oberholzer, Miriam; Frech, Christian M

2014-01-01

117

Preparation of polyhydroxyalkyl- and C-glycosylfuran derivatives from free sugars catalyzed by cerium(III) chloride in aqueous solution: an improvement of the Garcia González reaction.  

PubMed

Unprotected aldose sugars react smoothly with 1,3-diones or beta-ketoesters in the presence of CeCl(3).7H(2)O in aqueous solution to produce polyhydroxylalkyl- and C-glycosylfuran derivatives in excellent yield. Operationally simple, mild neutral reaction conditions in aqueous solution is the key feature of this methodology. PMID:15113679

Misra, Anup Kumar; Agnihotri, Geetanjali

2004-05-17

118

Mild Traumatic Brain Injury  

MedlinePLUS

... Frequently Asked Questions Glossary Contact Us mild Traumatic Brain Injury Click Here to Start VIDEO STORIES What ... most common deployment injuries is a mild Traumatic Brain Injury (TBI). A mild TBI is an injury ...

119

Chromatographic characterisation, under highly aqueous conditions, of a molecularly imprinted polymer binding the herbicide 2,4-dichlorophenoxyacetic acid.  

PubMed

The affinity of a 2,4-dichlorophenoxyacetic acid (2,4-D) molecularly imprinted polymer (MIP), which was synthesised directly in an aqueous organic solvent, for its template (2,4-D) was studied and compared with the affinity exhibited by two other reference (control) polymers, NIPA and NIPB, for the same analyte. Zonal chromatography was performed to establish the optimal selectivity, expressed as imprinting factor (IF), under chromatographic conditions more aqueous than those described so far in the literature. Frontal analysis (FA) was performed on columns packed with these polymers, using an optimized mobile phase composed of methanol/phosphate buffer (50/50, v/v), to extract adsorption isotherm data and retrieve binding parameters from the best isotherm model. Surprisingly, the template had comparable and strong affinity for both MIP (K = 3.8x10(4) M(-1)) and NIPA (K = 1.9x10(4) M(-1)), although there was a marked difference in the saturation capacities of selective and non-selective sites, as one would expect for an imprinted polymer. NIPB acts as a true control polymer in the sense that it has relatively low affinity for the template (K = 8.0x10(2) M(-1)). This work provides the first frontal chromatographic characterization of such a polymer in a water-rich environment over a wide concentration range. The significance of this work stems from the fact that the chromatographic approach used is generic and can be applied readily to other analytes, but also because there is an increasing demand for well-characterised imprinted materials that function effectively in aqueous media and are thus well-suited for analytical science applications involving, for example, biofluids and environmental water samples. PMID:17456420

Legido-Quigley, C; Oxelbark, J; De Lorenzi, E; Zurutuza-Elorza, A; Cormack, P A G

2007-05-15

120

Computer Simulation of Ion Cluster Speciation in Concentrated Aqueous Solutions at Ambient Conditions  

PubMed Central

Dynamic simulations are used to investigate ion cluster formation in unsaturated aqueous NaCl at 25 °C. Statistical, structural, and dynamic properties are reported. An effort is made to identify general behaviors that are expected to hold beyond the limitations of the force field. Above ~1 M, clusters with more than ten ions begin to form after ~10–20 ns of simulation time, but no evidence of irreversible ion aggregation is observed. Cluster survival times are estimated, showing that the kinetics becomes increasingly complex as salt is added, leading to multiple decay rates. Cluster dipole moment distributions show characteristic peaks that reflect the cluster preferred conformations in solution. These are modulated by electrostatic and liquid-structure forces, and are described in detail for clusters of up to five ions. For a given size and charge, the cluster morphology is independent of salt concentration. Below ~2 M, clusters affect the structure of water in their first hydration shells, so dipole moments parallel to the cluster macrodipoles are induced. These effects show a weak dependence with concentration below ~2 M, but vanish in the 2–3 M range. A possible connection with the structural transition recently suggested by NMR data in concentrated electrolytes is discussed. The effects of electrostatics on cluster speciation and morphology are discussed based on results from a set of simulations carried out with the ionic charges removed.

Hassan, Sergio A.

2008-01-01

121

Oligo-Glycine Synthesis in an Aqueous Solution of Glycine Under Oxidative Conditions  

NASA Astrophysics Data System (ADS)

Di-and tri-glycine were synthesized in 1M aqueous solution of glycine by bubbling for 90 hr with oxygen discharged in the path from an oxygen cylinder. The peptides were also produced by an incubation at 37°C of 2M glycine solution prepared with 75% hydrogen peroxide, and the yields were traced for 200 days. The final yields were about 0.25% and 0.01% for di-and tri-glycine, respectively. The solution at 166 days of incubation was applied to a Sephadex G 10 column, and the fractions around the top of the chromatogram were found to increase the intensity of ninhydrin color about 4˜5 times after hydrolysis, indicating an existence of oligo-glycine. The solutions of 1M glycine and 0.5M diglycine prepared with 30% hydrogen peroxide were incubated at 37°C for 38 days, and di-and tetra-glycine were detected in the yields of 0.12% and 0.33%, respectively.

Yamagata, Yukio; Yamashita, Atsunori; Inomata, Katsuhiko

1980-03-01

122

Effects of aqueous-phase acidity and salinity on isotonic swelling of W\\/O\\/W emulsion liquid membranes under agitation conditions  

Microsoft Academic Search

The effects of aqueous-phase acidity and salinity on the isotonic swelling behavior of water-in-oil-in-water (W\\/O\\/W) emulsion liquid membranes (ELMs) under agitation conditions was studied. A non-ionic surfactant (EMSORB 2500) was used to stabilize the membranes. The acidity of the aqueous phase was controlled by sulfuric acid and the salinity was controlled by sodium sulfate. The swelling of the ELMs was

Jun Yan; Rajinder Pal

2004-01-01

123

Towards a clinically useful diagnosis for mild-to-moderate conditions of medically unexplained symptoms in general practice: a mixed methods study  

PubMed Central

Background Symptoms that cannot be attributed to any known conventionally defined disease are highly prevalent in general practice. Yet, only severe cases are captured by the current diagnostic classifications of medically unexplained symptoms (MUS). This study explores the clinical usefulness of a proposed new diagnostic category for mild-to-moderate conditions of MUS labelled ‘multiple symptoms’. Methods A mixed methods approach was used. For two weeks, 20 general practitioners (GPs) classified symptoms presented in consecutive consultations according to the International Classification of Primary Care (ICPC) supplemented with the new diagnostic category ‘multiple symptoms’. The GPs’ experiences were subsequently explored by focus group interviews. Interview data were analysed according to ethnographic principles. Results In 33% of patients, GPs classified symptoms as medically unexplained, but applied the category of ‘multiple symptoms’ only in 2.8%. The category was described as a useful tool for promoting communication and creating better awareness of patients with MUS; as such, the category was perceived to reduce the risk of unnecessary tests and referrals of these patients. Three main themes were found to affect the clinical usefulness of the diagnostic category of ‘multiple symptoms’: 1) lack of consensus on categorisation practices, 2) high complexity of patient cases and 3) relational continuity (i.e. continuity in the doctor-patient relationship over time). The first two were seen as barriers to usefulness, the latter as a prerequisite for application. The GPs’ diagnostic classifications were found to be informed by the GPs’ subjective pre-formed concepts of patients with MUS, which reflected more severe conditions than actually intended by the new category of ‘multiple symptoms’. Conclusions The study demonstrated possible clinical benefits of the category of ‘multiple symptoms’, such as GPs’ increased awareness and informational continuity in partnership practices. The use of the category was challenged by the GPs’ conceptual understanding of MUS and was applied only to a minority of patients. The study demonstrates a need for addressing these issues if sub-threshold categories for MUS are to be applied in routine care. The category of ‘multiple symptoms’ may profitably be used in the future as a risk indicator rather than a diagnostic category.

2014-01-01

124

Mechanism of formation of organic carbonates from aliphatic alcohols and carbon dioxide under mild conditions promoted by carbodiimides. DFT calculation and experimental study.  

PubMed

Dicyclohexylcarbodiimide (CyN=C=NCy, DCC) promotes the facile formation of organic carbonates from aliphatic alcohols and carbon dioxide at temperatures as low as 310 K and moderate pressure of CO2 (from 0.1 MPa) with an acceptable rate. The conversion yield of DCC is quantitative, and the reaction has a very high selectivity toward carbonates at 330 K; increasing the temperature increases the conversion rate, but lowers the selectivity. A detailed study has allowed us to isolate or identify the intermediates formed in the reaction of an alcohol with DCC in the presence or absence of carbon dioxide. The first step is the addition of alcohol to the cumulene (a known reaction) with formation of an O-alkyl isourea [RHNC(OR')=NR] that may interact with a second alcohol molecule via H-bond (a reaction never described thus far). Such an adduct can be detected by NMR. In alcohol, in absence of CO2, it converts into a carbamate and a secondary amine, while in the presence of CO2, the dialkyl carbonate, (RO)2CO, is formed together with urea [CyHN-CO-NHCy]. The reaction has been tested with various aliphatic alcohols such as methanol, ethanol, and allyl alcohol. It results in being a convenient route to the synthesis of diallyl carbonate, in particular. O-Methyl-N,N'-dicyclohexyl isourea also reacts with phenol in the presence of CO2 to directly afford for the very first time a mixed aliphatic-aromatic carbonate, (MeO)(PhO)CO. A DFT study has allowed us to estimate the energy of each intermediate and the relevant kinetic barriers in the described reactions, providing reasonable mechanistic details. Calculated data match very well the experimental results. The driving force of the reaction is the conversion of carbodiimide into the relevant urea, which is some 35 kcal/mol downhill with respect to the parent compound. The best operative conditions have been defined for achieving a quantitative yield of carbonate from carbodiimide. The role of temperature, pressure, and catalysts (Lewis acids and bases) has been established. As the urea can be reconverted into DCC, the reaction described in this article may further be developed for application to the synthesis of organic carbonates under selective and mild conditions. PMID:16050675

Aresta, Michele; Dibenedetto, Angela; Fracchiolla, Elisabetta; Giannoccaro, Potenzo; Pastore, Carlo; Pápai, Imre; Schubert, Gábor

2005-08-01

125

X-ray photoelectron spectroscopic study of surface chemistry of dibenzyl-disulfide on steel under mild and severe wear conditions  

NASA Technical Reports Server (NTRS)

Wear tests were performed on 304 stainless steel lubricated with pure mineral oil with and without dibenzyl-disulfide. Both mild and severe wear were observed. The type of wear was distinguished by a marked change in wear rate, friction coefficient, and wear scar appearance. The chemical composition of the wear scar surface was examined with X-ray photoelectron spectroscopy in conjunction with argon ion sputter etching. In severe wear scars, a sulfide was formed at the expense of the normal oxide layer. In mild wear scars, there were only superficial sulfur compounds, but there was a substantial increase in the oxide thickness.

Wheeler, D. R.

1977-01-01

126

Determination of the optimum conditions for boric acid extraction with carbon dioxide gas in aqueous media from colemanite containing arsenic  

SciTech Connect

The Taguchi method was used to determine optimum conditions for the boric acid extraction from colemanite ore containing As in aqueous media saturated by CO{sub 2} gas. After the parameters were determined to be efficient on the extraction efficiency, the experimental series with two steps were carried out. The chosen experimental parameters for the first series of experiments and their ranges were as follows: (1) reaction temperature, 25--70 C; (2) solid-to-liquid ratio (by weight), 0.091 to 0.333; (3) gas flow rate (in mL/min), 66.70--711; (4) mean particle size, {minus}100 to {minus}10 mesh; (5) stirring speed, 200--600 rpm; (6) reaction time, 10--90 min. The optimum conditions were found to be as follows: reaction temperature, 70 C; solid-to-liquid ratio, 0.091; gas flow rate, 711 (in mL/min); particle size, {minus}100 mesh; stirring speed, 500 rpm; reaction time, 90 min. Under these optimum conditions, the boric acid extraction efficiency from the colemanite containing As was approximately 54%. Chosen experimental parameters for the second series of experiments and their ranges were as follows: (1) reaction temperature, 60--80 C; (2) solid-to-liquid ratio (by weight), 0.1000 to 0.167; (3) gas pressure (in atm), 1.5; 2.7; (4) reaction time, 45--120 min. The optimum conditions were found to be as follows: reaction temperature, 70 C; solid-to-liquid ratio, 0.1; gas pressure, 2.7 atm; reaction time, 120 min. Under these optimum conditions the boric acid extraction efficiency from the colemanite ore was approximately 75%. Under these optimum conditions, the boric acid extraction efficiency from calcined colemanite ore was approximately 99.55%.

Ata, O.N.; Colak, S.; Copur, M.; Celik, C.

2000-02-01

127

Solubility of AmOHCO{sub 3} in aqueous solution under atmospheric conditions  

SciTech Connect

Modeling calculations on the solubility of americium have indicated that basic americium carbonate, and not americium trihydroxide, is the solubility-controlling solid in the pH range from 6 to 10 under the influence of atmospheric CO{sub 2}. The solubility of crystalline {sup 243}AmOHCO{sup 3} has been investigated in batch experiments in near-neutral and basic solutions as a function of dissolution time in 0.1 M NaClO{sup 4} at room temperature under oxic conditions. After the solutions reached steady-state conditions, the influence of dissolved solids on the americium concentration in the supernatant solution was studied by utilizing several experimental methods to separate the solution phase from the solid. The solids were characterized by X-ray powder diffraction analysis.

Nitsche, H.

1987-12-01

128

Solubility of AmOHCO sub 3 in aqueous solution under atmospheric conditions  

SciTech Connect

Modeling calculations on the solubility of americium have indicated that basic americium carbonate, and not americium trihydroxide, is the solubility-controlling solid in the pH range from 6 to 10 under the influence of atmospheric CO{sub 2}. The solubility of crystalline {sup 243}AmOHCO{sup 3} has been investigated in batch experiments in near-neutral and basic solutions as a function of dissolution time in 0.1 M NaClO{sup 4} at room temperature under oxic conditions. After the solutions reached steady-state conditions, the influence of dissolved solids on the americium concentration in the supernatant solution was studied by utilizing several experimental methods to separate the solution phase from the solid. The solids were characterized by X-ray powder diffraction analysis.

Nitsche, H.

1987-12-01

129

X-Ray Photoelectron Spectroscopic Study of Surface Chemistry of Dibenzyl-Disulfide on Steel under Mild and Severe Wear Conditions.  

National Technical Information Service (NTIS)

Wear tests were performed on 304 stainless steel lubricated with pure mineral oil with and without dibenzyl-disulfide. Both mild and severe wear were observed. The type of wear was distinguished by a marked change in wear rate, friction coefficient, and w...

D. R. Wheeler

1977-01-01

130

Inhibited Cr(VI) reduction by aqueous Fe(II) under hyperalkaline conditions.  

PubMed

This study investigated Cr(VI) reduction by dissolved Fe(II) in hyperalkaline pH conditions as found in fluid wastes associated with the U.S. nuclear weapons program. The results show that Cr(VI) reduction by Fe(II) at alkaline pH solutions proceeds very quickly. The amount of Cr(VI) removed from solution and the amount reduced increases with Fe(II):Cr(VI) ratio. However, the Cr(VI) reduction under alkaline pH condition is nonstoichiometric, probably due to Fe(II) precipitation and mixed iron(III)-chromium-(III) (oxy)hydroxides blocking Fe(II) surface sites, as well as removing Fe(II) from solution through O2 oxidation. After Cr(VI) was reduced to Cr(III), it precipitated out as mixed Fe(x)Cr1-xO3(solids) and various Fe(III) precipitates with an overall Cr:Fe ratio of 1:3; all Cr remaining in the solution phase was unreduced Cr(VI). EXAFS data showed that Cr-O and Cr-Cr distances in the precipitates equal to 1.98 and 3.01 A, respectively, consistent with the spinel-type structure as chromite. PMID:15575269

He, Y Thomas; Chen, Chia-Chen; Traina, Samuel J

2004-11-01

131

Immobilization of selenate by iron in aqueous solution under anoxic conditions and the influence of uranyl  

NASA Astrophysics Data System (ADS)

In proposed high level radioactive waste repositories a large part of the spent nuclear fuel (SNF) canisters are commonly composed of iron. Selenium is present in spent nuclear fuel as a long lived fission product. This study investigates the influence of iron on the uptake of dissolved selenium in the form of selenate and the effect of the presence of dissolved uranyl on the above interaction of selenate. The iron oxide, and selenium speciation on the surfaces was investigated by Raman spectroscopy. X-ray Absorption Spectroscopy was used to determine the oxidation state of the selenium and uranium on the surfaces. Under the simulated groundwater conditions (10 mM NaCl, 2 mM NaHCO 3, <0.1 ppm O 2) the immobilized selenate was found to be reduced to oxidation states close to zero or lower and uranyl was found to be largely reduced to U(IV). The near simultaneous reduction of uranyl was found to greatly enhance the rate of selenate reduction. These findings suggest that the presence of uranyl being reduced by an iron surface could substantially enhance the rate of reduction of selenate under anoxic conditions relevant for a repository.

Puranen, Anders; Jonsson, Mats; Dähn, Rainer; Cui, Daqing

2009-08-01

132

Mild hypothermia alone or in combination with anesthetic post-conditioning reduces expression of inflammatory cytokines in the cerebral cortex of pigs after cardiopulmonary resuscitation  

PubMed Central

Introduction Hypothermia improves survival and neurological recovery after cardiac arrest. Pro-inflammatory cytokines have been implicated in focal cerebral ischemia/reperfusion injury. It is unknown whether cardiac arrest also triggers the release of cerebral inflammatory molecules, and whether therapeutic hypothermia alters this inflammatory response. This study sought to examine whether hypothermia or the combination of hypothermia with anesthetic post-conditioning with sevoflurane affect cerebral inflammatory response after cardiopulmonary resuscitation. Methods Thirty pigs (28 to 34 kg) were subjected to cardiac arrest following temporary coronary artery occlusion. After seven minutes of ventricular fibrillation and two minutes of basic life support, advanced cardiac life support was started according to the current American Heart Association guidelines. Return of spontaneous circulation was achieved in 21 animals who were randomized to either normothermia at 38°C, hypothermia at 33°C or hypothermia at 33°C combined with sevoflurane (each group: n = 7) for 24 hours. The effects of hypothermia and the combination of hypothermia with sevoflurane on cerebral inflammatory response after cardiopulmonary resuscitation were studied using tissue samples from the cerebral cortex of pigs euthanized after 24 hours and employing quantitative RT-PCR and ELISA techniques. Results Global cerebral ischemia following resuscitation resulted in significant upregulation of cerebral tissue inflammatory cytokine mRNA expression (mean ± SD; interleukin (IL)-1? 8.7 ± 4.0, IL-6 4.3 ± 2.6, IL-10 2.5 ± 1.6, tumor necrosis factor (TNF)? 2.8 ± 1.8, intercellular adhesion molecule-1 (ICAM-1) 4.0 ± 1.9-fold compared with sham control) and IL-1? protein concentration (1.9 ± 0.6-fold compared with sham control). Hypothermia was associated with a significant (P < 0.05 versus normothermia) reduction in cerebral inflammatory cytokine mRNA expression (IL-1? 1.7 ± 1.0, IL-6 2.2 ± 1.1, IL-10 0.8 ± 0.4, TNF? 1.1 ± 0.6, ICAM-1 1.9 ± 0.7-fold compared with sham control). These results were also confirmed for IL-1? on protein level. Experimental settings employing hypothermia in combination with sevoflurane showed that the volatile anesthetic did not confer additional anti-inflammatory effects compared with hypothermia alone. Conclusions Mild therapeutic hypothermia resulted in decreased expression of typical cerebral inflammatory mediators after cardiopulmonary resuscitation. This may confer, at least in part, neuroprotection following global cerebral ischemia and resuscitation.

2010-01-01

133

Diffusion and polymerization of styrene in an aqueous solution of potassium persulfate under static conditions  

SciTech Connect

The potassium persulfate-initiated polymerization of styrene in a mechanically agitated mixture of water and monomer leads to the formation of a stable, monodisperse latex. In order to explain the mechanism of the stabilization of the latex particles in this system, the authors present a detailed investigation of the polymerization of styrene in a specially constructed electrochemical cell under static conditions. A schematic of the cell is shown. Results show that the capacity of the electrical double layer on the platinum electrode remains constant with time in a system containing only a solution of electrolyte, either K/sub 2/SO/sub 4/ or K/sub 2/S/sub 2/O/sub 8/.

Oganesyan, A.A.; Boyadzhyan, V.G.; Gritskova, I.A.; Gukasyan, A.V.; Matsoyan, S.G.; Pravednikov, A.N.

1985-10-01

134

Solubility of aqueous methane under metastable conditions: implications for gas hydrate nucleation.  

PubMed

To understand the prenucleation stage of methane hydrate formation, we measured methane solubility under metastable conditions using molecular dynamics simulations. Three factors that influence solubility are considered: temperature, pressure, and the strength of the modeled van der Waals attraction between methane and water. Moreover, the naturally formed water cages and methane clusters in the methane solutions are analyzed. We find that both lowering the temperature and increasing the pressure increase methane solubility, but lowering the temperature is more effective than increasing the pressure in promoting hydrate nucleation because the former induces more water cages to form while the latter makes them less prevalent. With an increase in methane solubility, the chance of forming large methane clusters increases, with the distribution of cluster sizes being exponential. The critical solubility, beyond which the metastable solutions spontaneously form hydrate, is estimated to be ~0.05 mole fraction in this work, corresponding to the concentration of 1.7 methane molecules/nm(3). This value agrees well with the cage adsorption hypothesis of hydrate nucleation. PMID:23639139

Guo, Guang-Jun; Rodger, P Mark

2013-05-30

135

In situ Raman study and thermodynamic model of aqueous carbonate speciation in equilibrium with aragonite under subduction zone conditions  

NASA Astrophysics Data System (ADS)

Carbonate minerals may be recycled into the mantle at subduction zones. However, the evolution of carbonate minerals in equilibrium with aqueous fluids as well as the nature of the chemical species of dissolved carbon in the deep crust and mantle at high PT conditions are still unknown. In this study, we report an integrated experimental and theoretical study of the equilibration of CaCO3 minerals with pure water at subduction zone conditions over the pressure and temperature ranges 5–80 kbar and 300–400 °C. The fluid speciation was studied using in situ Raman spectroscopy. The relative amounts of dissolved carbonate and bicarbonate were estimated from the corrected areas of the Raman bands of the carbonate and bicarbonate ions and used to constrain a theoretical thermodynamic model of the fluid speciation and solubility of aragonite. At 300–400 °C, our results indicate that the proportion of dissolved C present as CO2 strongly decreases in fluids in equilibrium with aragonite at P > 10 kbar. CO2 is replaced by HCO3? and CaHCO3+ which predominate until P > 40 kbar, where CO32? and CaCO30 become the dominant C-species. At higher temperatures, the theoretical model indicates that CO2 again becomes a major species in fluids in equilibrium with aragonite depending on the pressure.

Facq, Sébastien; Daniel, Isabelle; Montagnac, Gilles; Cardon, Hervé; Sverjensky, Dimitri A.

2014-05-01

136

Unprecedented Selective Oxidation of Styrene Derivatives using a Supported Iron Oxide Nanocatalyst in Aqueous Medium  

EPA Science Inventory

Iron oxide nanoparticles supported on mesoporous silica-type materials have been successfully utilized in the aqueous selective oxidation of alkenes under mild conditions using hydrogen peroxide as a green oxidant. Catalysts could be easily recovered after completion of the reac...

137

Rare-earth metal oxide doped transparent mesoporous silica plates under non-aqueous condition as a potential UV sensor.  

PubMed

Transparent mesoporous silica plates doped with rare-earth metal oxide were prepared using solvent-evaporation method based on the self-organization between structure-directing agent and silicate in a non-aqueous solvent. A triblock copolymer, Pluronic (F127 or P123), was used as the structure-directing agent, while tetraethyl orthosilicate (TEOS) was used as a silica source. The pore diameter and the surface area of the mesoporous silica plate prepared with the optimized conditions were ca 40 A and 600 m2 g(-1), respectively, for both structure-directing agent. Rare-earth metal oxides (Eu, Tb, Tm oxide) in mesochannel were formed via one-step synthetic route based on the preparation method of a silica plate. Optical properties of rare-earth metal oxide-doped mesoporous silica plates were investigated by UV irradiation and photoluminescence (PL) spectroscopy. Under the exitation wavelength of 254 nm, the doped mesoporous silica plates emitted red, green and blue for Eu, Tb and Tm oxides, respectively. Rare-earth metal oxide-doped mesoporous silica plates showed enhanced PL intensity compared to that of the bulk rare-earth metal oxide. PMID:24245274

Lee, Sang-Joon; Park, Sung Soo; Lee, Sang Hyun; Hong, Sang-Hyun; Ha, Chang-Sik

2013-11-01

138

Steady-state ?-radiolysis of aqueous methyl ethyl ketone (2-butanone) under postulated nuclear reactor accident conditions  

Microsoft Academic Search

The steady-state ?-radiolysis of aqueous solutions containing 1×10?3 mol dm?3 methyl ethyl ketone (MEK) has been studied at a dose rate of 0.12 Gy s?1, 25°C and an initial pH of 10. Experiments were conducted in air-, Ar- or N2O-purged aqueous solutions, or in Ar-purged solutions with added tert-butanol. MEK, its radiolytic products, and the change in pH resulting from

P. Driver; G. Glowa; J. C. Wren

2000-01-01

139

Solubility of platinum in aqueous solutions at 25°C and pHs 4 to 10 under oxidizing conditions  

NASA Astrophysics Data System (ADS)

Platinum has been found to be mobile under supergene conditions, including placers and weathering profiles. To elucidate the nature of Pt mobility in supergene environments, the dissolution of platinum metal was investigated under physicochemical conditions similar to those found in such environments. The solubility of platinum metal was measured at 25°C in several systems: Pt-K-HC 8H 4O 4-H 2O (pH 4.02), Pt-Na-HCO 3-Cl-H 2O (pH 6.40), Pt-Na-K-H 2PO 4-HPO 4-H 2O (pH 6.90), Pt-Na-HCO 3-H 2O (pH 8.30), Pt-Na-OH-H 2O (pH 8.54), and Pt-Na-HCO 3-H 2O (pH 9.91). The redox conditions of these experiments were relatively oxidizing, with measured Eh values ranging from +280 to +590 mV. The ionic strength of the aqueous solutions did not exceed 0.30 (molal scale). The interpretation of the solubility results, in terms of the following reaction and its equilibrium constant, Pt( s)+ nH2O ? Pt( OH) 2- nn+ nH++2 e- served to identify the importance of the hydroxylated complex PtOH + in the pH range (4 to 10) and to determine its stability constant at 25°C. Linear regression of the solubility data using the function log [ Pt]-2 pe= npH+ logKn yielded a value of 1.01 ± 0.07 for n, the average ligand number, and -31.76 ± 0.55 for the thermodynamic equilibrium constant of reaction. The resulting stability constant (? 1) of PtOH + (Pt 2+ + OH - ? PtOH +) is 24.91 ± 0.50, assuming the same value of the free energy of formation of Pt 2+, ?G fo(Pt 2+) as that given by Glushko et al. ( Thermodynamic Constants of Matter, Academy of Science, USSR, 1972). The range of values of ?G fo(Pt 2+) proposed to date is +185.63 to +258.74 kJ/mol. The value of Glushko et al. (1972) (+244.11 kJ/mol) appears to fit better with our measurements at pH 4 to 10 and with those of Wood (Wood S. A., "Experimental determination of the hydrolysis constants of Pt 2+ and Pd 2+ at 25°C from the solubility of Pt and Pd in aqueous hydroxide solutions," Geochim. Cosmochim. Acta55, 1759-1767, 1991) at pH 9 to 15.5. Finally, according to these new measurements of the solubility of platinum, the recommended values for Gibbs free energy (?G fo, in kiloJoule per mole) of the different aqueous species of Pt are +244.11 (Pt 2+), -55.96 (PtOH +), and -234.48 (Pt(OH) 2(aq)). The integration of data from the literature for chloride and sulfate complexes was used to calculate the speciation of platinum in seawater and in solutions with variable chlorinity (0.1, 1, and 3 mol/L NaCl) at 25°C. These calculations showed that in the absence of strong ligands (i.e., S 2O 32-, CN -), the transport of platinum in supergene environments primarily occurs in the form of PtOH + (90%) and Pt(OH) 2(aq) (9.7%). Chloride complexes (PtCl 42- and PtCl 3-) account for less than 1% of the dissolved platinum. This study clearly shows that the hydroxylated complexes (PtOH + and Pt(OH) 2(aq)) can play a very important role in controlling platinum transfer mechanisms in surface fluids (soils, placers, weathering profiles, etc.). Because the charged species PtOH + is largely predominant, the mobility and transfer of platinum can also be affected by adsorption-desorption mechanisms onto oxides and hydroxides.

Azaroual, Mohamed; Romand, Bruno; Freyssinet, Philippe; Disnar, Jean-Robert

2001-12-01

140

Treatment of rheumatoid arthritis and other related conditions by provoking a mild infection to be controlled by the immune system itself.  

PubMed

When rheumatoid arthritis presents, the immune system overcompensates and acts attacking the joints and the body in general, the same thing occurs with other autoimmune diseases; the immunological mechanisms that manifest in these diseases have been identified, but there is still no explanation as to why this occurs. This article will present a hypothesis that is based on provoking a mild infection in patients with rheumatoid arthritis, and other related autoimmune diseases, an infection that does not result in serious consequences to the health of the patients, but does generate an immunological response, in this manner, the immune system itself, which is overcompensating, will fight the provoked infection instead of causing damage to the body itself. PMID:17280795

Halabe Bucay, Alberto

2007-01-01

141

Steady-state gamma-radiolysis of aqueous methyl ethyl ketone (2-butanone) under postulated nuclear reactor accident conditions  

Microsoft Academic Search

The steady-state gamma-radiolysis of aqueous solutions containing 1x10-3 mol dm-3 methyl ethyl ketone (MEK) has been studied at a dose rate of 0.12 Gy s-1, 25 degC and an initial pH of 10. Experiments were conducted in air-, Ar- or N2O-purged aqueous solutions, or in Ar-purged solutions with added tert-butanol. MEK, its radiolytic products, and the change in pH resulting

P. Driver; G. Glowa; J. C. Wren

2000-01-01

142

Diastereoselective synthesis of cyclopentanediols by InCl 3/Al mediated intramolecular pinacol coupling reaction in aqueous media.  

PubMed

A "green" and practical intramolecular pinacol coupling reaction promoted by InCl 3/Al catalysts in aqueous media has been developed. Under mild conditions, a novel class of polysubstituted cyclopentane-1,2-diols have been obtained with excellent diastereoselectivity. PMID:18971861

Chen, Yunhua; Wan, Jieping; Wang, Chunyan; Sun, Cuirong

2008-01-01

143

Oxalic acid mediated synthesis of WO{sub 3}.H{sub 2}O nanoplates and self-assembled nanoflowers under mild conditions  

SciTech Connect

Tungsten oxide hydrate (WO{sub 3}.H{sub 2}O) nanoplates and flower-like assemblies were successfully synthesized via a simple aqueous method. The effects of reaction parameters in solution on the preparation were studied. Nanoplates and nanoflowers can be selectively prepared by changing the amount of H{sub 2}C{sub 2}O{sub 4}. In-situ assembly of nanoplates to nanoflowers was also proposed for the formation of assembled nanostructures. In addition, the reaction time and temperature have important effects on the sizes of the as-obtained samples. Crystal structure, morphology, and composition of final nanostructures were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Optical properties of the synthesized samples and the growth mechanism were studied by UV-vis detection. Degradation experiments of Rhodamine B (RhB) were also performed on samples of nanoplates and nanoflowers under visible light illumination. Nanoflower sample exhibited preferable photocatalytic property to nanoplate sample. - Graphical abstract: The oxalic acid has a key role for the structure of WO{sub 3}.H{sub 2}O evolution from plates to flowers and the dehydration process of WO{sub 3}.2H{sub 2}O to WO{sub 3}.H{sub 2}O. Highlights: > Tungsten oxides hydrate was synthesized via a simple aqueous method. > The size of WO{sub 3}.H{sub 2}O was controlled by the reaction time and temperature. > The assembly of WO{sub 3}.H{sub 2}O nanoplates to nanoflowers was achieved with higher H{sub 2}C{sub 2}O{sub 4}/Na{sub 2}WO{sub 4} ratio. > Oxalic acid has a key role in the dehydration process of WO{sub 3}.2H{sub 2}O to WO{sub 3}.H{sub 2}O.

Li Linzhi [College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Zhao Jingzhe, E-mail: zhaojz@hnu.edu.cn [College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Wang Yi [Department of Regenerative Medicine, School of Pharmaceutical Sciences, Jilin University, Changchun 130023 (China); Li Yunling [College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); College of Chemistry, Jilin University, Changchun, 130012 (China); Ma Dechong [College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Zhao Yan [College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); College of Chemistry, Jilin University, Changchun, 130012 (China); Hou Shengnan; Hao Xinli [College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China)

2011-07-15

144

Kinetics of OH-initiated oxidation of some oxygenated organic compounds in the aqueous phase under tropospheric conditions  

Microsoft Academic Search

The interest for multiphase interactions of Volatile Organic Compounds (VOCs) in the troposphere has increased for a few years. Inside the clouds water droplets, soluble VOCs can be oxidized by free radicals thus modifying the droplet composition. This reactivity has an impact on the tropospheric oxidizing capacity as well as the aerosols' properties. In the present work, we measured aqueous

L. Poulain; S. Grubert; S. François; A. Monod; H. Wortham

2003-01-01

145

Caustic Stress Corrosion Cracking of Mild Steel  

Microsoft Academic Search

The stress corrosion cracking (SCC) behavior of cold worked mild steel in hot, aqueous, 33 pct NaOH solutions was studied\\u000a with prefatigue cracked double cantilever beam specimens. SCC kinetics were studied under freely corroding potentials (E\\u000a corr ? ?1.00 VSHE) and potentiostatic potentials of ?0.76 VSHE near the active-passive transition. The pH of the liquid within the crack was determined

Douglas Singbeil; Desmond Tromans

1982-01-01

146

Zinc modified polypyrrole coating on mild steel  

Microsoft Academic Search

Polypyrrole (PPy) films (?1.7 ?m thick) have been electrodeposited on mild steel (MS) substrates from 0.1 M pyrrole containing aqueous oxalic acid solution, by using cyclic voltammetry technique. Then, the polymer coatings were modified with deposition of zinc particles (?1 mg\\/cm2), at a constant potential value of ?1.20 V in 0.2 M ZnSO4 solution. The corrosion performance of zinc modified PPy coating has been investigated

Tunç Tüken

2006-01-01

147

Use of pervaporation to separate butanol from dilute aqueous solutions: Effects of operating conditions and concentration polarization  

Microsoft Academic Search

This study deals with the separation of n-butanol from aqueous solutions by pervaporation. The effects of feed concentration, temperature, and membrane thickness on the separation performance were investigated. Over the low feed butanol concentration range (0.03–0.4wt%) studied, the butanol flux was shown to increase proportionally with an increase in the feed butanol concentration, whereas the water flux was relatively constant.

Elsayed A. Fouad; Xianshe Feng

2008-01-01

148

Chromatographic characterisation, under highly aqueous conditions, of a molecularly imprinted polymer binding the herbicide 2,4-dichlorophenoxyacetic acid  

Microsoft Academic Search

The affinity of a 2,4-dichlorophenoxyacetic acid (2,4-D) molecularly imprinted polymer (MIP), which was synthesised directly in an aqueous organic solvent, for its template (2,4-D) was studied and compared with the affinity exhibited by two other reference (control) polymers, NIPA and NIPB, for the same analyte. Zonal chromatography was performed to establish the optimal selectivity, expressed as imprinting factor (IF), under

C. Legido-Quigley; J. Oxelbark; E. De Lorenzi; A. Zurutuza-Elorza; P. A. G. Cormack

2007-01-01

149

Formation of carboxylic acids from alcohols and olefins in zeolite H-ZSM-5 under mild conditions via trapping of alkyl carbenium ions with carbon monoxide: An in situ {sup 13}C solid state NMR study  

SciTech Connect

Using in situ {sup 13}C solid state MAS NMR (for some reagents in combination with ex situ GC-MS), it is shown that butyl alcohols and olefins (ethene, isobutene, octene-1) undergo carbonylation to form carboxylic acids (the Koch reaction) with high conversion on zeolite H-ZSM-5 at 296-373 K. The reactions proceed without application of pressurized conditions, just upon coadsorption of CO and alcohols or CO, H{sub 2}O, and olefins on zeolite. The observed Koch reaction under mild conditions provides strong evidence for the formation of alkyl carbenium ions from alcohols and olefins on the zeolites as crucial reaction intermediates. Of the family of carbenium ions, CO reacts selectively with tertiary cations to produce tertiary carboxylic acids, unless the carbonylated molecule is too large for more bulky tertiary moieties to be accommodated and carbonylated in the narrow pores of H-ZSM05. Thus, t-BuOH, i-BuOH, and isobutene produce trimethylacetic acid with high selectivity and conversion, while ethene transforms selectively into 2-methyl-2-ethyl butyric acid. Reaction of octene-1 molecules with CO and H{sub 2}O results in acids of the C{sub 8}H{sub 17}COOH and C{sub 16}H{sub 33}COOH families with predominantly linear hydrocarbon chains. The data obtained may open up new possibilities in using solid acids in organic synthesis as carbonylation catalysts under mild conditions i.e., low temperature and normal atmospheric pressure. 55 refs., 8 figs.

Stepanov, A.G.; Luzgin, M.V.; Romannikov, V.N.; Sidelnikov, V.N.; Zamaraev K.I. [Boreskov Inst. of Catalysis, Novosibirsk (Russian Federation)] [Boreskov Inst. of Catalysis, Novosibirsk (Russian Federation)

1996-12-01

150

Efficient batch and continuous flow Suzuki cross-coupling reactions under mild conditions, catalysed by polyurea-encapsulated palladium (II) acetate and tetra-n-butylammonium salts.  

PubMed

Suzuki cross-coupling reactions are effected in both conventional organic solvents, under continuous flow conditions at 70 degree C, and in batch mode in supercritical carbon dioxide (scCO2), at temperatures as low as 40 degrees C in the presence of palladium(II) acetate microencapsulated in polyurea [PdEnCat] and tetra-n-butylammonium salts. PMID:15846438

Lee, Connie K Y; Holmes, Andrew B; Ley, Steven V; McConvey, Ian F; Al-Duri, Bushra; Leeke, Gary A; Santos, Regina C D; Seville, Jonathan P K

2005-04-28

151

Mild Cognitive Impairment Research  

MedlinePLUS Videos and Cool Tools

... Media Text Size Videos and Media Virtual Library Brain Tour Facts & Figures Spotlight on Researchers Web Links ... early diagnosis Mild Cognitive Impairment Research Inside the brain Genetics in Alzheimer's Advances in brain imaging Diet ...

152

Relaxation of the structure of simple metal ion complexes in aqueous solutions at up to supercritical conditions  

USGS Publications Warehouse

Recently x-ray absorption fine structure (XAFS) studies of various ions in aqueous solutions showed a variation of cation-ligand bond lengths, often coupled with other structure changes, with increasing temperatures. Thus, the variations of the structure of several metal ion complexes with temperature based on observations from the X-ray absorption fine structure (XAFS) studies in the hope that it will stimulate the development of either first- principles theory or molecular dynamics simulations that might adequately describes these results are discussed.

Mayanovic, R. A.; Jayanetti, S.; Anderson, A. J.; Bassett, W. A.; Chou, I. -M.

2003-01-01

153

Corrosion protection of mild steel by coatings containing polyaniline  

Microsoft Academic Search

The anti-corrosion performance of polyaniline coated mild steel samples exposed to artificial brine and dilute hydrochloric acid environments was evaluated. Samples of mild steel (UNS G10100) coated with polyaniline deposited from solution, and overcoated with an epoxy barrier paint, when scratched to expose precise areas of bare metal, exhibited corrosion rates in aqueous 3.5% NaCl solutions 2 times less, and

Wei-Kang Lu; Ronald L. Elsenbaumer; Bernhard Wessling

1995-01-01

154

Control of dual stimuli-responsive vesicle formation in aqueous solutions of single-tailed ferrocenyl surfactant by varying pH and redox conditions.  

PubMed

This paper reports a method to control the formation and disruption of vesicles from a novel single-tailed surfactant (11-ferrocenylundecylammonium bromide, 11-FAB), which contains two stimuli-responsive groups corresponding to pH variation and redox reaction conditions, by external stimuli. Although 11-FAB is a single-tailed surfactant, pure 11-FAB spontaneously forms vesicles in water. Microscopic observations of 2.5 mM aqueous solutions of pure 11-FAB (pH = 5.2) show that a number of 11-FAB vesicles are giant, with diameters of 10-30 ?m. The disruption of vesicles is observed in aqueous 11-FAB solutions under basic conditions. The vesicles are then reformed under acidic conditions. Reduced 11-FAB also forms large vesicles in electrolyte solutions. These vesicles are disrupted by electrochemical oxidation and reformed by subsequent chemical reduction. This reversible disruption and reformation of vesicles is attributed to the drastic change in the molecular structure of 11-FAB. To our knowledge, this is the first report of control over the formation and disruption of vesicles using two stimuli responses. PMID:24492378

Hata, Shinichi; Takahashi, Hiro; Takahashi, Yutaka; Kondo, Yukishige

2014-02-26

155

Engineered protein A ligands, derived from a histidine-scanning library, facilitate the affinity purification of IgG under mild acidic conditions  

PubMed Central

Background In antibody purification processes, the acidic buffer commonly used to elute the bound antibodies during conventional affinity chromatograph, can damage the antibody. Herein we describe the development of several types of affinity ligands which enable the purification of antibodies under much milder conditions. Results Staphylococcal protein A variants were engineered by using both structure-based design and combinatorial screening methods. The frequency of amino acid residue substitutions was statistically analyzed using the sequences isolated from a histidine-scanning library screening. The positions where the frequency of occurrence of a histidine residue was more than 70% were thought to be effective histidine-mutation sites. Consequently, we identified PAB variants with a D36H mutation whose binding of IgG was highly sensitive to pH change. Conclusion The affinity column elution chromatograms demonstrated that antibodies could be eluted at a higher pH (?pH**?2.0) than ever reported (?pH?=?1.4) when the Staphylococcal protein A variants developed in this study were used as affinity ligands. The interactions between Staphylococcal protein A and IgG-Fab were shown to be important for the behavior of IgG bound on a SpA affinity column, and alterations in the affinity of the ligands for IgG-Fab clearly affected the conditions for eluting the bound IgG. Thus, a histidine-scanning library combined with a structure-based design was shown to be effective in engineering novel pH-sensitive proteins.

2014-01-01

156

Preparation and Applications of Xanthenylamide (XAL) Handles for Solid-Phase Synthesis of C-Terminal Peptide Amides under Particularly Mild Conditions(1-3).  

PubMed

[[9-[(9-Fluorenylmethyloxycarbonyl)amino]xanthen-2(or 3)-yl]oxy]alkanoic acid (XAL) handles have been prepared by efficient four-step routes from 2- or 3-hydroxyxanthone and coupled onto a range of amino-functionalized supports. The resultant XAL supports are the starting points for solid-phase peptide synthesis by Fmoc chemistry. Upon completion of chain assembly, C-terminal peptide amides are released in excellent yields and purities by use of low concentrations [1-5% (v/v)] of trifluoroacetic acid (TFA) in dichloromethane, often without a need for added carbocation scavengers. These cleavage conditions allow retention of all or a significant portion of tert-butyl type and related side-chain protecting groups, which subsequently may be removed fully in a solution process carried out at higher acid concentration. XAL supports are particularly useful for the synthesis of acid-sensitive peptides, including tryptophan-containing sequences that are known to be susceptible to yield- and/or purity-reducing alkylation side reactions. The effectiveness of this chemistry was shown with the syntheses of prothrombin (1-9), acyl carrier protein (65-74), Tabanus atratus adipokinetic hormone, fragments of the protein RHK 1, CCK-8 sulfate, and oxytocin. Furthermore, the application of XAL supports for the preparation of fully protected peptide amides has been demonstrated. PMID:11667474

Han, Yongxin; Bontems, Susan L.; Hegyes, Peter; Munson, Mark C.; Minor, Charles A.; Kates, Steven A.; Albericio, Fernando; Barany, George

1996-09-01

157

Partial complex I deficiency due to the CNS conditional ablation of Ndufa5 results in a mild chronic encephalopathy but no increase in oxidative damage.  

PubMed

Deficiencies in the complex I (CI; NADH-ubiquinone oxidoreductase) of the respiratory chain are frequent causes of mitochondrial diseases and have been associated with other neurodegenerative disorders, such as Parkinson's disease. The NADH-ubiquinone oxidoreductase 1 alpha subcomplex subunit 5 (NDUFA5) is a nuclear-encoded structural subunit of CI, located in the peripheral arm. We inactivated Ndufa5 in mice by the gene-trap methodology and found that this protein is required for embryonic survival. Therefore, we have created a conditional Ndufa5 knockout (KO) allele by introducing a rescuing Ndufa5 cDNA transgene flanked by loxP sites, which was selectively ablated in neurons by the CaMKII?-Cre. At the age of 11 months, mice with a central nervous system knockout of Ndufa5 (Ndufa5 CNS-KO) showed lethargy and loss of motor skills. In these mice cortices, the levels of NDUFA5 protein were reduced to 25% of controls. Fully assembled CI levels were also greatly reduced in cortex and CI activity in homogenates was reduced to 60% of controls. Despite the biochemical phenotype, no oxidative damage, neuronal death or gliosis were detected in the Ndufa5 CNS-KO brain at this age. These results showed that a partial defect in CI in neurons can lead to late-onset motor phenotypes without neuronal loss or oxidative damage. PMID:24154540

Peralta, Susana; Torraco, Alessandra; Wenz, Tina; Garcia, Sofia; Diaz, Francisca; Moraes, Carlos T

2014-03-15

158

New associative systems based on alkylated hyaluronic acid. Synthesis and aqueous solution properties  

Microsoft Academic Search

This paper concerns the preparation of new water-soluble alkylated derivatives of hyaluronan (HA); these derivatives were synthesized under mild aqueous and well controlled conditions. The first step was to prepare a HA derivative selectively modified with adipic dihydrazide (HA-ADH) with a substitution degree of 0.08; then, alkyl chains with different chain lengths were introduced with a substitution degree around 0.05.

Caroline Creuzet; Shirin Kadi; Marguerite Rinaudo; Rachel Auzély-Velty

2006-01-01

159

Silver-catalyzed decarboxylative trifluoromethylthiolation of aliphatic carboxylic acids in aqueous emulsion.  

PubMed

A silver-catalyzed decarboxylative trifluoromethylthiolation of secondary and tertiary carboxylic acids under mild conditions tolerates a wide range of functional groups. The reaction was dramatically accelerated by its performance in an aqueous emulsion, which was formed by the addition of sodium dodecyl sulfate to water. It was proposed that the radical, which was generated from the silver-catalyzed decarboxylation in the "oil-in-water" droplets, could easily react with the trifluoromethylthiolating reagent to form the product. PMID:24764209

Hu, Feng; Shao, Xinxin; Zhu, Dianhu; Lu, Long; Shen, Qilong

2014-06-10

160

Temperature and density effects on structural features of a dilute aqueous lithium chloride solution at near- and supercritical conditions  

Microsoft Academic Search

The structural features of a 0.24molal LiCl(aq) solution at near- (T=573K, ?1=1.0g\\/cm3, ?2=0.65g\\/cm3) and supercritical (T=1073K, ?=0.65g\\/cm3) conditions were studied by the extended RISM integral equation method. It was found that on transition from ambient conditions into the supercritical state the tetrahedral network of water is destroyed, ions are thermally dehydrated and ion association to contact ion pairs is promoted.

Marina V. Fedotova

2011-01-01

161

Mutation spectrum in the lacI gene, induced by gamma-radiation in aqueous solution under oxic conditions.  

PubMed

Irradiation of DNA in a cellular environment leads to many types of DNA damage, resulting from various effects of gamma-radiation. One of these effects is the formation of water-derived radicals (e.g., .OH radicals), which are formed in the vicinity of DNA (indirect effect). To study the influence of the indirect effect on gamma-radiation-induced mutations, a newly constructed plasmid, containing the lacI gene as a target gene, was irradiated with 60Co gamma-radiation in aqueous solution, in the presence of oxygen. Under these circumstances, only .OH radicals will be responsible for the induced mutations. Sequence analysis of the gamma-radiation-induced mutations showed that 96% of all mutations were base pair substitutions, 87% of which occurred in the lacI gene, the others are formed in the lac operator part. All gamma-radiation-induced mutations in the lacI gene occurred exclusively on G:C base pairs, and no mutations at A:T base pairs could be detected. In the spontaneous mutation spectrum, 83% of all mutations were base pair substitutions, 35% of which occurred in the lacI gene and 48% in the lac operator part. Base pair substitutions on G:C base pairs were very similar in the gamma-radiation-induced and in the spontaneous mutation spectrum, implying a high contribution of .OH radicals to spontaneous mutagenesis. A:T to G:C transitions accounted for 10% of all spontaneous base pair substitutions in the lacI gene and are probably the result of effects, other than just .OH radicals. It can be concluded that .OH radicals are an important source for mutations at G:C base pairs. In this paper, the extracellular gamma-radiation-induced mutation spectrum is also compared to the previously obtained, intracellular gamma-radiation-induced mutation spectrum of the lacI gene. Comparison shows some differences, such as relative high amounts of mutations at A:T base pairs, G:C to T:A transversions and frameshift mutations in the intracellular gamma-radiation-induced mutation spectrum, as compared to the extracellular gamma-radiation-induced mutation spectrum. Since the extracellular gamma-radiation-induced mutation spectrum shows that .OH radicals are mainly responsible for base pair substitutions on G:C base pairs, mutations at A:T base pairs in the intracellular gamma-radiation-induced mutation spectrum are apparently the result of additional or other factors. PMID:9726014

Wijker, C A; Wientjes, N M; Lafleur, V M

1998-07-17

162

Basalt and olivine dissolution under cold, salty, and acidic conditions: What can we learn about recent aqueous weathering on Mars?  

NASA Astrophysics Data System (ADS)

To test which variables may be important for weathering on Mars, the effects of temperature (22°C, 6°C, and -19°C), high ionic strength, and oxygen concentrations were investigated in batch dissolution experiments containing forsterite, fayalite, and basalt glass. CaCl2-NaCl-H2O brine can remain liquid to temperatures of -55°C and thus may be liquid in the cold, dry climate that currently characterizes Mars. To understand weathering under such conditions, dissolution rates were measured in experiments in distilled water with and without CaCl2 and NaCl. As observed by others, dissolution rates increased with temperature, and only fayalite dissolution was significantly affected by the presence or absence of oxygen. Enhanced fayalite dissolution under anoxic conditions suggests that Fe-rich olivine would dissolve more rapidly than Mg-rich olivine on Mars. Dissolution in the two most dilute experimental solutions (deionized water and CaCl2-NaCl-H2O solution of ionic strength = 0.7 m) were the same within uncertainty, but apparent dissolution rate constants in CaCl2-NaCl-H2O brines were significantly slower. Steady silica concentrations are decreased in the brines, consistent with other work, and precipitation rates of silica decrease with decreasing temperatures. These results suggest that enhanced silica precipitation could be an indicator of high ionic strength solutions on Mars. Consistent with these observations, weathering of basalt has been observed to sometimes be accompanied by precipitated layers of silica in cold, dry environments on Earth. If dissolution on Mars occurs or occurred under conditions similar to our experiments, cation leaching would be expected to be accompanied by silica precipitates on weathering surfaces.

Hausrath, E. M.; Brantley, S. L.

2010-12-01

163

Application of Zero-Valent Iron Nanoparticles for the Removal of Aqueous Zinc Ions under Various Experimental Conditions  

PubMed Central

Application of zero-valent iron nanoparticles (nZVI) for Zn2+ removal and its mechanism were discussed. It demonstrated that the uptake of Zn2+ by nZVI was efficient. With the solids concentration of 1 g/L nZVI, more than 85% of Zn2+ could be removed within 2 h. The pH value and dissolved oxygen (DO) were the important factors of Zn2+ removal by nZVI. The DO enhanced the removal efficiency of Zn2+. Under the oxygen-contained condition, oxygen corrosion gave the nZVI surface a shell of iron (oxy)hydroxide, which could show high adsorption affinity. The removal efficiency of Zn2+ increased with the increasing of the pH. Acidic condition reduced the removal efficiency of Zn2+ by nZVI because the existing H+ inhibited the formation of iron (oxy)hydroxide. Adsorption and co-precipitation were the most likely mechanism of Zn2+ removal by nZVI. The FeOOH-shell could enhance the adsorption efficiency of nZVI. The removal efficiency and selectivity of nZVI particles for Zn2+ were higher than Cd2+. Furthermore, a continuous flow reactor for engineering application of nZVI was designed and exhibited high removal efficiency for Zn2+.

Liang, Wen; Dai, Chaomeng; Zhou, Xuefei; Zhang, Yalei

2014-01-01

164

Mild cognitive impairment: animal models  

PubMed Central

Mild cognitive impairment (MCI) is an aspect of cognitive aging that is considered to be a transitional state between normal aging and the dementia into which it may convert. Appropriate animal models are necessary in order to understand the pathogenic mechanisms of MCI and develop drugs for its treatment. In this review, we identify the features that should characterize an animal model of MCI, namely old age, subtle memory impairment, mild neuropathological changes, and changes in the cholinergic system, and the age at which these features can be detected in laboratory animals. These features should occur in aging animals with normal motor activity and feeding behavior. The animal models may be middle-aged rats and mice, rats with brain ischemia, transgenic mice overexpressing amyloid precursor protein and presenilin 1 (tested at an early stage), or aging monkeys. Memory deficits can be detected by selecting appropriately difficult behavioral tasks, and the deficits can be associated with neuropathological alterations. The reviewed literature demonstrates that, under certain conditions, these animal species can be considered to be MCI models, and that cognitive impairment in these models responds to drug treatment.

Pepeu, Giancarlo

2004-01-01

165

Mild Cognitive Impairment: Ten Years Later  

PubMed Central

In the past 10 years, there has been a virtual explosion in the literature concerning the construct of mild cognitive impairment. The interest in this topic demonstrates the increasing emphasis on the identification of the earliest features of cognitive disorders such as Alzheimer’s disease and other dementias. Mild cognitive impairment represents the earliest clinical features of these conditions and, hence, has become a focus of clinical, epidemiological, neuroimaging, biomarker, neuropathological, disease mechanism and clinical trials research. This review summarizes the progress that has been made while also recognizing the challenges that remain.

Petersen, Ronald C.; Knopman, David S.; Boeve, Bradley F.; Geda, Yonas E.; Ivnik, Robert J.; Smith, Glenn E.; Roberts, Rosebud O.; Jack, Clifford R.

2010-01-01

166

Effect of preparation conditions of oil palm fronds activated carbon on adsorption of bentazon from aqueous solutions.  

PubMed

Oil palm fronds (OPF) were used to prepare activated carbon (PFAC) using physiochemical activation method, which consisted of potassium hydroxide (KOH) treatment and carbon dioxide gasification. The effects of the preparation variables, which were activation temperature, activation time and chemical impregnation ratios (KOH: char by weight), on the carbon yield and bentazon removal were investigated. Based on the central composite design (CCD), two factor interaction (2FI) and quadratic models were, respectively, employed to correlate the PFAC preparation variables to the bentazon removal and carbon yield. From the analysis of variance (ANOVA), the most influential factor on each experimental design response was identified. The optimum conditions for preparing activated carbon from OPF were found as follows: activation temperature of 850 degrees C, activation time of 1h and KOH:char ratio of 3.75:1. The predicted and experimental results for removal of bentazon and yield of PFAC were 99.85%, 20.5 and 98.1%, 21.6%, respectively. PMID:19879687

Salman, J M; Hameed, B H

2010-03-15

167

Experimental investigation and planetary implications of the stability of clathrate hydrates in aqueous solution at icy satellite conditions  

NASA Astrophysics Data System (ADS)

Clathrate hydrates consist of hydrogen-bonded water molecules forming cages in which gas molecules are trapped individually. They are among the favored volatile reservoirs in solar system bodies, and are expected to play an important role in many processes: accretion of volatiles in planetesimals, outgassing on Titan, Enceladus, and comets. Their insulating thermal properties and high mechanical strength also bear important implications for understanding the evolution of icy satellites like Europa. However, the conditions allowing for their formation and/or their dissociation and the release of volatiles to the atmosphere (Titan) or the plumes (Enceladus) are still poorly understood. This is mainly because of a lack of knowledge on the stability of mixed clathrate hydrates in presence of anti-freeze agents such as ammonia. We have developed a high-pressure cryogenic calorimeter to address this deficiency in the literature. This liquid nitrogen - cooled Setaram BT2.15 calorimeter is located at the JPL Ice Physics Laboratory. The temperature range achievable with this instrument is 77-473 K. This calorimeter uses Calvet elements (3D arrays of thermocouples) to measure the heat flow required to follow a predefined heating rate within a sample and a reference cell with a resolution of 0.1 ?W. A gas handling system has been designed and fabricated in house to reach pressures up to 100 bars, corresponding to several km depth in icy satellites. The thermodynamic properties of CO2 and CH4 clathrates with ammonia are under investigation, and the results will be used to constrain a statistical thermodynamic model of clathrates for applications to planetary environments. Preliminary results will be shown at the meeting. This work has been conducted at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA. Support from the Minnesota Space Grant Consortium, the NASA Outer Planets Research program, and government sponsorship are gratefully acknowledged.

Dunham, M.; Choukroun, M.; Barmatz, M.; Hodyss, R. P.; Smythe, W. D.

2012-12-01

168

Iron isotope fractionation among magnetite, pyrrhotite, chalcopyrite, rhyolite melt and aqueous fluid at magmatic-hydrothermal conditions  

NASA Astrophysics Data System (ADS)

Fractionation of non-traditional stable isotopes (NTSI) such as Fe in magmatic systems is a relatively understudied subject. The fractionation of Fe stable isotopes has been quantified in some natural igneous samples, but there is a paucity of experimental data that could provide further insight into the causative processes of the observed fractionation. Substantial experimental work has been performed at higher temperatures pertaining to the formation of chondrites and the Earth's core, but only a handful of studies have addressed crustal rocks. To fill this knowledge gap, we performed isothermal, isobaric experiments containing mineral (e.g., magnetite, Fe-sulfides) and fluid, or mineral, rhyolite melt, and fluid assemblages to quantify equilibrium fractionation factors (?). These data, to our knowledge, are the first data that quantify the effect of a fluid phase on iron isotope fractionation at conditions appropriate for evolving magmatic systems. Charges were run inside gold capsules held in a René-41 cold seal vessel, and heated to 400, 600, or 800°C at 150 MPa for mineral-fluid, and 800°C and 100 MPa for mineral-melt-fluid runs. Use of the René vessel fixed the fO2 at the NNO buffer, an oxidation state consistent with arc magmas. The isotopic compositions of the starting and quenched phases were obtained by using a Multi-Collector Plasma Mass Spectrometer (MC-ICP-MS). Equilibrium was assessed by performing time-series runs and the three-isotope method, used only once before in a similar Fe isotope study. Correlation between Fe isotope mass and oxidation state is also being explored. Magnetite-fluid results indicate enrichment of heavy Fe isotopes in the mineral relative to the fluid, consistent with measurements of felsic igneous rocks. Magnetite-melt-fluid relationships are also consistent with measurements of natural samples. In the latter assemblage, over the course of the run, the rhyolite melt becomes heavy relative to the fluid while magnetite takes on a heavier Fe isotope signature than the starting value. These data corroborate the hypothesis that fluid exsolution caused the isotopic patterns observed in highly-differentiated igneous rocks. Further, owing to the ubiquitous importance of melt degassing as a critical process for the formation of magmatic-hydrothermal ore deposits, these data may be potentially serve as an exploration tool. This work contributes to our overall understanding of igneous processes by elucidating the Fe isotope fingerprints observed in the field as well as develop the laboratory techniques needed to study NTSI fractionation in magmatic systems and build a reliable dataset for interpretation of natural systems.

Bilenker, L. D.; Simon, A.; Lundstrom, C.; Gajos, N.

2012-12-01

169

A novel method of non-violent dissolution of sodium metal in a concentrated aqueous solution of Epsom salt  

Microsoft Academic Search

A new technique of non-violent and fast dissolution of sodium metal in a concentrated aqueous solution of Epsom salt (MgSO4.7H2O) at room temperature (RT) has been developed. The dissolution process is mildly exothermic but could be carried out even in a glass beaker in air under swift stirring condition. The reaction products consist of mixed salts of MgSO4 and Na2SO4

A. R. Lakshmanan; M. V. R. Prasad; D. Ponraju; H. Krishnan

2004-01-01

170

Irradiation of MEK — II: A detailed kinetic model for the degradation of 2-butanone in aerated aqueous solutions under steady-state ?-radiolysis conditions  

Microsoft Academic Search

The radiolytic decomposition of aqueous phase 2-butanone (methyl ethyl ketone (MEK)) has been studied extensively to gain a detailed mechanistic understanding of the effects of organic impurities on the behaviour of iodine in containment following a nuclear reactor accident. Based on the experimental results reported previously, a detailed reaction kinetic model for the steady-state ?-radiolysis of aerated aqueous solutions containing

Glenn Glowa; Paul Driver; Jungsook Clara Wren

2000-01-01

171

Remarkably Facile Heck Reactions in Aqueous Two-Phase System Catalyzed by Reusable Pd\\/C Under Ligand-Free Condition  

Microsoft Academic Search

A fast and convenient Heck reaction was achieved catalyzed by Pd\\/C in aqueous two-phase system. The aqueous two-phase system has been shown to be a highly active solvent for Heck reactions of aryl halides even in the absence of organic ligands.

Yan-Qin Yuan; Sheng-Rong Guo

2011-01-01

172

Remarkably Facile Heck Reactions in Aqueous Two-Phase System Catalyzed by Reusable Pd\\/C Under Ligand-Free Conditions  

Microsoft Academic Search

A fast and convenient Heck reaction was achieved catalyzed by Pd\\/C in aqueous two-phase system. The aqueous two-phase system has been shown to be a highly active solvent for Heck reactions of aryl halides even in the absence of organic ligands.

Yan-Qin Yuan; Sheng-Rong Guo

2012-01-01

173

Mild gasification of coal  

SciTech Connect

The objective of this initial year's mission-oriented multi-year program is to develop a process chemistry data base for the mild gasification of coal with emphasis on eastern bituminous coal. One important objective of this program was to obtain the trends in product formation from different coals as a function of several process variables which included temperature, pressure, coal particle residence time, coal flow rate, type of additives such as lime, limestone, silica flour and ash in a short period of time. This was achieved by a careful development of a test matrix using a fractional factorial statistical design. The equipment used was the Brookhaven National Laboratory (BNL) combination stirred moving-bed, entrained-tubular reactor which is capable of processing 2 to 3 pounds of coal per hour. A Wellmore Kentucky No. 8 bituminous coal, a Pittsburgh No. 8 bituminous coal and a Mississippi lignite with particles having a size of 150 {mu}m or less were selected for this study. The mild gasification experiments were conducted at temperatures from 550{degree} to 650{degree}C at nitrogen sweep gas pressures of 15 to 50 psi and residence times of 0.1 to 2 min. The coal flow rate was 0. 4 to 1.0 lb/hr and the concentration of the lime additives was 0 to 10% by weight of the dry coal feed. All variables were tested at two different levels, low and high, corresponding to the above ranges of the variables. A rapid calculation of the main effects and interactions was made using Yate's algorithm and the significance of the effects was determined from the normal probability plots. 10 refs., 26 figs., 11 tabs.

Sundaram, M.S.; Fallon, P.T.; Steinberg, M.

1989-01-01

174

Self-assembled dicopper(II) diethanolaminate cores for mild aerobic and peroxidative oxidation of alcohols.  

PubMed

The new dicopper(ii) complexes [Cu(2)(?-Hmdea)(2)(NCS)(2)] (1) and [Cu(2)(?-Hedea)(2)(N(3))(2)]·(H(2)O)(0.25) (2) with the {Cu(2)(?-O)(2)} diethanolaminate cores have been easily generated by aqueous medium self-assembly reactions of copper(ii) nitrate with N-methyl- or N-ethyldiethanolamine (H(2)mdea or H(2)edea, respectively), in the presence of sodium thiocyanate (for 1) or sodium azide (for 2) as ancillary ligands sources. They have been isolated as air-stable crystalline solids and fully characterized by IR and UV-vis spectroscopies, ESI-MS(+), elemental and single-crystal X-ray diffraction analyses. The latter complex also features a fourfold linkage of neighbouring dimeric units via strong intermolecular O-HO hydrogen bonds, giving rise to the formation of tetracopper aggregates. The catalytic activity of compounds 1 and 2 has been studied for the mild (50-80 °C) and selective oxidations of alcohols, namely for (i) the aerobic aqueous medium oxidation of benzyl alcohols to benzaldehydes, mediated by TEMPO radical, and for (ii) the solvent-free oxidation of secondary alcohols to ketones by t-BuOOH under microwave (MW) irradiation. Complex 2 shows the highest efficiency in both oxidation systems, resulting in up to 99% molar yields (based on the alcohol substrate) of products. In addition, remarkably high values of TON (1020) and TOF (4080 h(-1)) have been achieved in the MW-assisted peroxidative oxidation of 1-phenylethanol to acetophenone (model reaction). Attractive green features of these catalytic systems include the operation in aqueous or solvent-free reaction medium, under mild conditions and with high yields and selectivities, using Cu catalyst precursors that are readily available by self-assembly in water of simple chemicals. PMID:20844801

Figiel, Pawe? J; Kirillov, Alexander M; Guedes da Silva, M Fátima C; Lasri, Jamal; Pombeiro, Armando J L

2010-11-01

175

On the formation and structure of rare-earth element complexes in aqueous solutions under hydrothermal conditions with new data on gadolinium aqua and chloro complexes  

Microsoft Academic Search

Synchrotron X-ray spectroscopy experiments were made on the Gd(III) aqua and chloro complexes in low pH aqueous solutions at temperatures ranging from 25 to 500 °C and at pressures up to 480 MPa using a hydrothermal diamond anvil cell. Analysis of fluorescence Gd L3-edge X-ray absorption fine structure (XAFS) spectra measured from a 0.006m Gd\\/0.16m HNO3 aqueous solution at temperatures up to

Robert A. Mayanovic; Alan J. Anderson; William A. Bassett; I-Ming Chou

2007-01-01

176

Mild Cognitive Impairment  

PubMed Central

Purpose of Review: The term mild cognitive impairment (MCI) is used to describe older subjects with demonstrable cognitive impairment who have not crossed the threshold for dementia. Because patients with MCI have an increased risk of developing dementia, especially Alzheimer disease (AD), there is significant interest in the clinical characterization of these subjects and in understanding the pathophysiology of the transition from MCI to AD. Recent Findings: The MCI syndrome, as an expression of an incipient disorder that may lead to dementia, is extremely heterogeneous and may coexist with systemic, neurologic, or psychiatric disorders that can cause cognitive deficits. Recent clinical criteria were designed to take into account the different forms of clinical presentation of the syndrome, and introduced the possible contribution of biomarkers to the clinical diagnosis. Bedside diagnosis of MCI can be difficult, since patients who report having cognitive problems may have normal scores in global cognitive scales or in brief neuropsychological instruments. Summary: This article presents the evolution of the clinical concept of MCI, the operationalization of its current definitions, the development of biomarkers that can help to identify an underlying neurodegenerative process as the etiology of the syndrome, and its proposed treatments.

Lopez, Oscar L.

2013-01-01

177

Zinc modified polyaniline coating for mild steel protection  

Microsoft Academic Search

Polyaniline (PANi) coating (?1.1?m thick) was synthesized electrochemically on mild steel (MS), from 0.1M aniline containing aqueous oxalic acid solution and using cyclic voltammetry technique. Then, this PANi coating was modified with the deposition of zinc particles from 0.2M ZnSO4 solution. The electrodeposition of zinc particles (approximately 1mg\\/cm2) has been achieved, at the constant potential value of ?1.20V. The corrosion

Tunç Tüken; Birgül Yaz?c?; Mehmet Erbil

2006-01-01

178

Staudinger ligation towards cyclodextrin dimers in aqueous/organic media. Synthesis, conformations and guest-encapsulation ability.  

PubMed

?-Cyclodextrin (?-CD) dimers have been prepared using the bioorthogonal Staudinger ligation for the first time. In addition to a known linker, methyl 2-(diphenylphosphanyl)terephthalate, a doubly active linker was specifically developed that enabled connection of two ?-CD units in a single step and in aqueous/organic media, under mild conditions and with good yields. A three-carbon spacer between the ?-CD torus and the azido group was required for facile dimer formation. The products, as studied by NMR spectroscopy, were found to adopt closed conformations by intramolecular self-inclusion. On the other hand, association via intermolecular binding was also observed in aqueous solution, confirmed by DOSY NMR experiments. Despite self-inclusion, the ?-CD cavities were capable of guest encapsulation, as shown by titration experiments: the binding constant with 1-adamantylamine was similar to that of natural ?-CD. Theoretical calculations for isolated molecules (PM3 level of theory) and in the presence of solvent [water, PM3(COSMO)] as well as DFT calculations suggested that the compounds prefer to adopt conformations which bring the phenyl groups either inside the ?-CD cavity (inclusion) or over its narrow side (vicinal). Thus, Staudinger ligation could be the method of choice for linking CDs exhibiting (i) ease of preparation in aqueous media, in short steps, under mild conditions and in good yields, (ii) satisfactory aqueous solubility and independent binding capacity of the cavities. PMID:24778732

Manouilidou, Malamatenia D; Lazarou, Yannis G; Mavridis, Irene M; Yannakopoulou, Konstantina

2014-01-01

179

Mild analgesics in postoperative pain  

PubMed Central

1 The intensity of postoperative pain is influenced by many factors, for example, individual variation, site of incision and type of operation, anaesthetic technique, and the interval from the end of operation to the appearance of pain. 2 These factors affect the efficacy of analgesics. 3 Mild analgesics provide adequate pain relief in half of our patients in the immediate postoperative phase when the pain is slight to moderate. 4 The maximum effect of mild analgesics corresponds to that produced by morphine 6-10 mg. Adequate analgesia may not therefore be provided for the treatment of severe postoperative pain unless narcotic analgesics have been used peroperatively. 5 When mild analgesics are combined with narcotics synergism is achieved. 6 As postoperative pain decreases with time, mild analgesics usually provide adequate pain relief on the first and following postoperative days.

Tammisto, T.; Tigerstedt, I.

1980-01-01

180

Isolated mild fetal ventriculomegaly  

Microsoft Academic Search

Ventriculomegaly is an excess of fluid in the lateral ventricles within the developing cerebrum. It is usually diagnosed at a routine fetal anomaly scan at 18–22 weeks gestation. Management of the condition and counselling of parents are difficult, as the cause, absolute risk, and degree of resulting handicap cannot be determined with confidence.

M Wyldes; M Watkinson

2004-01-01

181

Electropolymerization of poly( N-ethyl aniline) on mild steel: Synthesis, characterization and corrosion protection  

Microsoft Academic Search

Poly(N-ethylaniline) (PNEA) coatings on the mild steel electrode were synthesized by electrochemical oxidation of N-ethylaniline using aqueous oxalic acid solutions as reaction medium. Electrodeposition was carried out by potentiodynamic, potentiostatic and galvanostatic synthesis techniques. Smooth, adhesive and thick PNEA coatings on mild steel could be electrosynthesized during sequential scanning of the potential region between ?0.5 and 1.4V versus SCE, with

Aziz Ya?an; Nuran Özçiçek Pekmez; Attila Y?ld?z

2006-01-01

182

UV photolysis of perfluorooctanoic acid (PFOA) in dilute aqueous solution.  

PubMed

Perfluorooctanoic acid (PFOA) is very persistent in the environment and widely detected in the water environment. Only some advanced methods with extreme reaction conditions are shown to be capable of degrading the compound efficiently, and almost all the earlier investigations used very high PFOA concentrations. The compound is detected normally at very low concentrations in the water environment, while mild reaction conditions for its degradation are preferable. This article aimed to elucidate photodegradation of PFOA in dilute aqueous solutions by combined UV wavelengths (185 nm+254 nm) and 254 nm using a newly designed UV jacket. PFOA degradation was greatly enhanced with the combined wavelengths with almost one hundred percent PFOA removals in four-hour reaction. The removals were well described by the first-order reaction kinetic. The removal efficiencies and rate values significantly decreased with smaller initial PFOA concentrations. But defluorination was greatly enhanced with smaller PFOA concentrations possibly due to accelerated decomposition of fluorinated intermediates of PFOA. Formic acid and acetic acid were two tentatively identified intermediates of PFOA photolysis while the former was a major intermediate predominantly controlling solution pH during the oxidation. The results demonstrated that PFOA photolysis by the combined wavelengths with mild reaction conditions can be greatly enhanced by proper design of UV jacket and reactor system. PMID:21252431

Giri, R R; Ozaki, H; Morigaki, T; Taniguchi, S; Takanami, R

2011-01-01

183

A review of catalytic issues and process conditions for renewable hydrogen and alkanes by aqueous-phase reforming of oxygenated hydrocarbons over supported metal catalysts  

Microsoft Academic Search

We have recently developed a single-step, low-temperature process for the catalytic production of fuels, such as hydrogen and\\/or alkanes, from renewable biomass-derived oxygenated hydrocarbons. This paper reviews our work in the development of this aqueous-phase reforming (APR) process to produce hydrogen or alkanes in high yields. First, the thermodynamic and kinetic considerations that form the basis of the process are

R. R. Davda; J. W. Shabaker; G. W. Huber; R. D. Cortright; J. A. Dumesic

2005-01-01

184

Photoarylation of alkenes and heteroaromatics by dibromo-BINOLs in aqueous solution.  

PubMed

The photochemistry of 6,6'-dibromo-BINOL (BINOL = 2,2'-dihydroxy-1,1'-binaphthyl) under mild basic conditions and its methyl and triisopropylsilyl ethers has been investigated in neat and aqueous acetonitrile through product distribution analysis and laser flash photolysis. Arylation and alkylation have been successfully achieved in the presence of allyltrimethylsilane, ethyl vinyl ether, pyrrole, pyridine, thiophene, benzene, and indole. Such a photoreactivity offers a metal and protecting group free synthetic protocol toward mono- and disubstituted 6-aryl/alkyl BINOLs, since the BINOL chirality is preserved in the photoactivation process. PMID:20361737

Verga, Daniela; Doria, Filippo; Pretali, Luca; Freccero, Mauro

2010-05-21

185

Nucleophilic trapping nitrilimine generated by photolysis of diaryltetrazole in aqueous phase.  

PubMed

Nitrilimine generated by photolysis of diaryltetrazole in aqueous phase under mild conditions was trapped by nucleophiles including amines and thioalcohols. The representative products were characterized, while products with all 20 natural amino acids and a peptide were observed by MALDI-TOF mass spectroscopy. Competitive studies showed that this reaction also occurred in the presence of acrylamide. These results provided new information for understanding the potential side reactions when tetrazole-alkene pairs were used as a bioorthogonal reaction in labeling proteins and related studies in buffered systems. PMID:24378969

Zhang, Yixin; Liu, Wujun; Zhao, Zongbao K

2013-01-01

186

Partitioning of trace elements between olivine and aqueous fluids at high P-T conditions: implications for the effect of fluid composition on trace-element transport  

NASA Astrophysics Data System (ADS)

In order to investigate the effect of fluid composition on trace-element transport at high pressure and temperature, olivine/fluid partition coefficients ( D) were measured in experiments involving aqueous carbonate-, chlorine- and NaOH- bearing fluids at 1.0 GPa and 1000°C. Radiotracers of Ce, Gd, Yb, Ba, Sr, Cs, and Na were used to monitor trace-element levels. D values were calculated by mass balance using the trace-element contents of acid-washed olivines from run-products combined with whole-sample abundances. A single reversal experiment in which pre-doped olivine was annealed in tracer-free water yielded results consistent with forward experiments involving olivine + H 2O. This result suggests crystal/fluid equilibrium was approached over the 5-day durations used for all experiments. Partition coefficients were found to vary with fluid chemistry and, with the exception of the D's for Na, olivine/fluid values are markedly lower than those determined for olivine/H 2O. Interelement ratios in the fluid also vary with fluid chemistry as exemplified by enhanced partitioning of Ce relative to Gd into Na, K or Cs carbonate-bearing compositions. Consideration of the trace-element exchange equilibria between olivine and fluid suggests that variation in the activity coefficient for aqueous trace-element and charge-balancing cations is likely to account for the interfluid variation in D values. Na partitioning is interpreted to be coupled to the formation of Na sbnd Al complexes as has been suggested in previous studies. These data indicate that, although trace elements do not partition strongly into H 2O coexisting with olivine, the addition of dissolved salts dramatically changes this result. Such variation in D values for different fluid chemistries suggests that fluid composition, in addition to residual mineralogy, may affect both absolute trace-element abundances and interelement fractionation in high P-T aqueous fluids.

Brenan, James M.; Bruce Watson, E.

1991-12-01

187

Experimental studies of a single-effect absorption refrigerator using aqueous lithium-bromide: Effect of operating condition to system performance  

SciTech Connect

This paper describes an experimental investigation of a single-effect absorption using aqueous lithium-bromide as working fluid. A 2 kW cooling capacity experimental refrigerator was tested with various operating temperatures. It was found that the solution circulation ratio (SCR) has a strong effect on the system performance. The measured SCR was 2-5 times greater than the theoretical prediction. This was due to the low performance of the absorber. The use of solution heat exchanger could increase the COP by up to 60%. (author)

Aphornratana, Satha [Sirindhorn International Institute of Technology, Thammasat University, P.O. Box 22, Thammasat Rangsit Post Office, Patumthani 12121 (Thailand); Sriveerakul, Thanarath [Department of Mechanical Engineering, Ubon Ratchathani University, Ubon Ratchathani 34190 (Thailand)

2007-11-15

188

"White Privilege": A Mild Critique  

ERIC Educational Resources Information Center

White privilege analysis has been influential in philosophy of education. I offer some mild criticisms of this largely salutary direction--its inadequate exploration of its own normative foundations, and failure to distinguish between "spared injustice", "unjust enrichment" and "non-injustice-related" privileges; its inadequate exploration of the…

Blum, Lawrence

2008-01-01

189

Neuropsychological Function in Mild Hyperphenylalaninemia.  

ERIC Educational Resources Information Center

Tests of executive functions and control tasks not assessing executive function were administered to 19 individuals (ages 6-28) mild hyperphenylalaninemia (MHP) and 19 controls. Tests of academic skills and behavior-rating questionnaires were also administered to the group with MHP. No group differences were found for any measure. (Contains…

Smith, Mary Lou; Saltzman, Jennifer; Klim, Paula; Hanley, William B.; Feigenbaum, Annette; Clarke, Joe T. R.

2000-01-01

190

Energy recovery via mild gasification  

Microsoft Academic Search

A mild gasification research process unit capable of processing up to one ton of coal per day has been constructed at UCC Research Corporation, Bristol, Virginia. The unit is very flexible utilizing coal preparation waste, bituminous, and subbituminous coal as feedstocks. The results, to date, have been encouraging, in that a high quality condensable hydrocarbon has been produced and a

R. A. Wolfe; C. J. Im; B. L. Gillespie; M. R. Ghate

1986-01-01

191

Aqueous humor catecholamines.  

PubMed

The catecholamines norepinephrine, (NE) epinephrine (E) and dopamine (DA) were detected for the first time in the aqueous humor of humans under general anesthesia and monkeys under ketamine. The catecholamine levels in aqueous humor of 9 humans were assayed. NE was 0.796 +/- 0.457 ng./ml., E ranged between 0 and 0.132 ng./ml. in 4 out of 9 subjects, and DA was found in 2 of the 9 eyes. (0. 123ng ./ml. and 0. 318ng ./ml..) Plasma levels were measured in 8 of the human subjects at the time of aqueous sampling -NE was 0.311 +/- 0.171, E ranged between 0 and 0.097 (4 out of 8 subjects) and DA was detected in one subject- 0.037 ng./ml.. Monkey aqueous levels were NE:2.843 +/- 0.668 and DA:0.462 +/- 0.177 ng./ml., with an intact iris. (N = 8 eyes.) NE was 0.497 +/- 0.049, and DA 0.426 +/- 0.218 ng./ml. after total iridectomy. (N = 4 eyes) E was not detected in the monkey under these conditions. Whilst NE may be produced in part by the iris, DA levels were not affected by iridectomy. This implies that DA may be produced by structures unrelated to sympathetic nerve endings of the iris in the anterior segment of the non-human primate eye, perhaps by diffusion from the ciliary body or retina. Ketamine is known to inhibit catecholamine uptake, which may explain the high levels measured in the monkey. Human aqueous catecholamine levels measured under anesthesia may be affected by a variety of the drugs used. It is postulated that dopaminergic neurones and associated receptors may be present in the anterior segment of the eye. This may explain the presence of aqueous humor dopamine and the effects of dopaminergic drugs on intraocular pressure. PMID:6734261

Cooper, R L; Constable, I J; Davidson, L

1984-06-01

192

In situ study of mass transfer in aqueous solutions under high pressures via Raman spectroscopy: a new method for the determination of diffusion coefficients of methane in water near hydrate formation conditions.  

PubMed

A new method was developed for in situ study of the diffusive transfer of methane in aqueous solution under high pressures near hydrate formation conditions within an optical capillary cell. Time-dependent Raman spectra of the solution at several different spots along the one-dimensional diffusion path were collected and thus the varying composition profile of the solution was monitored. Diffusion coefficients were estimated by the least squares method based on the variations in methane concentration data in space and time in the cell. The measured diffusion coefficients of methane in water at the liquid (L)-vapor (V) stable region and L-V metastable region are close to previously reported values determined at lower pressure and similar temperature. This in situ monitoring method was demonstrated to be suitable for the study of mass transfer in aqueous solution under high pressure and at various temperature conditions and will be applied to the study of nucleation and dissolution kinetics of methane hydrate in a hydrate-water system where the interaction of methane and water would be more complicated than that presented here for the L-V metastable condition. PMID:16542563

Lu, W J; Chou, I M; Burruss, R C; Yang, M Z

2006-02-01

193

Corrosion protection of mild steel by polypyrrole coatings in acid sulfate solutions  

Microsoft Academic Search

The corrosion behaviour of mild steel covered by the electrodeposited polypyrrole films was investigated by electrochemical impedance spectroscopy. Electrodeposition of polypyrrole was performed from aqueous solution of pyrrole and oxalic acid at a constant current density of 1 mA cm?2 and yields strongly adherent and smooth polymer layers. The impedance spectra were treated through the nonlinear least squares (NLS) fitting

N. V. Krstaji?; B. N. Grgur; S. M. Jovanovi?; M. V. Vojnovi?

1997-01-01

194

Is Vanadate Reduced by Thiols under Biological Conditions?: Changing The Redox Potential of V(V)/V(IV) by Complexation in Aqueous solution  

PubMed Central

Although dogma states that vanadate is readily reduced by glutathione, cysteine and other thiols, there are several examples documenting that vanadium(V)-sulfur complexes can form and be observed. This conundrum has impacted life scientists for more than two decades. Investigation of this problem requires an understanding of both the complexes that form from vanadium(IV) and (V) and a representative thiol in aqueous solution. The reactions of vanadate and hydrated vanadyl cation with 2-mercaptoethanol have been investigated using multinuclear NMR, EPR and UV-vis spectroscopy. Vanadate forms a stable complex of 2:2 stoichiometry with 2-mercaptoethanol at neutral and alkaline pH. In contrast, vanadate can oxidize 2-mercaptoethanol; this process is favored at low pH and high solute concentrations. The complex that forms between aqueous vanadium(IV) and 2-mercaptoethanol has a 1:2 stoichiometry and can be observed at high pH and high 2-mercaptoethanol concentration. The solution structures have been deduced and speciation diagrams prepared. This work demonstrates that both vanadium(IV) and (V)-thiol complexes form and that redox chemistry also takes place. Whether reduction of vanadate takes place is governed by a combination of parameters: pH, solute- and vanadate-concentrations and the presence of other complexing ligands. Based on these results it is now possible to understand the distribution of vanadium in oxidation states (IV) and (V) in the presence of glutathione, cysteine and other thiols and begin to evaluate the forms of the vanadium compounds that exert a particular biological effect including the insulin-enhancing agents, anti-amoebic agents and interactions with vanadium binding proteins.

Crans, Debbie C.; Zhang, Boyan; Gaidamauskas, Ernestas; Keramidas, Anastasios D.; Willsky, Gail R.; Roberts, Chris R.

2010-01-01

195

Competitive Intramolecular/Intermolecular Chelation Options Operative during Indium-Promoted Additions to Pyridyl Aldehydes and to Glyoxylic Acid under Aqueous Conditions.  

PubMed

The stereochemical course of the 1,2-addition of six allylindium reagents to 2- and 3-pyridinecarboxaldehyde and to glyoxylic acid has been investigated in order to assess the level and direction of diastereoselectivity in these coupling reactions. When 2-PyCHO is involved, the results strongly suggest that the ring nitrogen becomes chelated to the indium atom in the aqueous environment. One striking observation is the crossover in stereoselectivity seen relative to the use of 3-PyCHO. A second revealing fact is the significantly faster rate of reaction of 2-PyCHO, as long as steric effects are not allowed to interfere. The varying product distributions observed in the latter experiments are attributed to other control elements such as intramolecular chelation within the indium reagent and nonbonded steric restrictions resident in either or both reaction partners. In the absence of extramolecular chelating events (e.g., when 3-PyCHO is involved), adherence to Felkin-Anh transition-state alignments is presumably exercised. The previous working assumption that indium(III) is capable of chelation to flanking heteroatomic centers in water is supported by the present investigation. PMID:11674106

Paquette, Leo A.; Rothhaar, Roger R.

1999-01-01

196

VOC destruction by water diluted hydrogen mild combustion  

Microsoft Academic Search

This study represents a preliminary numerical evaluation of the effect of steam dilution and hydrogen addition on the oxidation of formaldehyde and benzene, chosen as representative of the volatile organic compounds (VOC), in mild condition by evaluating the autoignition time and the steady state attainment. These parameters are important in the design of thermal VOC destruction plants since they influence

P. Sabia; F. Romeo; M. de Joannon; A. Cavaliere

2007-01-01

197

Cholinergic Enhancement of Frontal Lobe Activity in Mild Cognitive Impairment  

ERIC Educational Resources Information Center

Cholinesterase inhibitors positively affect cognition in Alzheimer's disease (AD) and other conditions, but no controlled functional MRI studies have examined where their effects occur in the brain. We examined the effects of donepezil hydrochloride (Aricept[Registered sign]) on cognition and brain activity in patients with amnestic mild cognitive…

Saykin, Andrew J.; Wishart, Heather A.; Rabin, Laura A.; Flashman, Laura A.; McHugh, Tara L.; Mamourian, Alexander C.; Santulli, Robert B.

2004-01-01

198

Music Enhances Autobiographical Memory in Mild Alzheimer's Disease  

ERIC Educational Resources Information Center

Studies have shown that the "Four Seasons" music may enhance the autobiographical performance of Alzheimer's disease (AD) patients. We used a repeated measures design in which autobiographical recall of 12 mild AD patients was assessed using a free narrative method under three conditions: (a) in "Silence," (b) after being exposed to the opus "Four…

El Haj, Mohamad; Postal, Virginie; Allain, Philippe

2012-01-01

199

Formation of Carboxylic Acids from Alcohols and Olefins in Zeolite H-ZSM-5 under Mild Conditions via Trapping of Alkyl Carbenium Ions with Carbon Monoxide: An in Situ 13C Solid State NMR Study  

Microsoft Academic Search

Usingin situ13C solid state MAS NMR (for some reagents in combination withex situGC-MS), it is shown that butyl alcohols and olefins (ethene, isobutene, octene-1) undergo carbonylation to form carboxylic acids (the Koch reaction) with high conversion on zeolite H-ZSM-5 at 296–373 K. The reactions proceed without application of pressurized conditions, just upon coadsorption of CO and alcohols or CO, H2O,

Alexander G. Stepanov; Mikhail V. Luzgin; Vyacheslav N. Romannikov; Vladimir N. Sidelnikov; Kirill I. Zamaraev

1996-01-01

200

Hematite Spherules in Basaltic Tephra Altered Under Aqueous, Acid-Sulfate Conditions on Mauna Kea Volcano, Hawaii: Possible Clues for the Occurrence of Hematite-Rich Spherules in the Burns Formation at Meridiani Planum, Mars  

NASA Technical Reports Server (NTRS)

Iron-rich spherules (>90% Fe2O3 from electron microprobe analyses) approx.10-100 microns in diameter are found within sulfate-rich rocks formed by aqueous, acid-sulfate alteration of basaltic tephra on Mauna Kea volcano, Hawaii. Although some spherules are nearly pure Fe, most have two concentric compositional zones, with the core having a higher Fe/Al ratio than the rim. Oxide totals less than 100% (93-99%) suggest structural H2O and/or /OH. The transmission Moessbauer spectrum of a spherule-rich separate is dominated by a hematite (alpha-Fe2O3) sextet whose peaks are skewed toward zero velocity. Skewing is consistent with Al(3+) for Fe(3+) substitution and structural H2O and/or /OH. The grey color of the spherules implies specular hematite. Whole-rock powder X-ray diffraction spectra are dominated by peaks from smectite and the hydroxy sulfate mineral natroalunite as alteration products and plagioclase feldspar that was present in the precursor basaltic tephra. Whether spherule formation proceeded directly from basaltic material in one event (dissolution of basaltic material and precipitation of hematite spherules) or whether spherule formation required more than one event (formation of Fe-bearing sulfate rock and subsequent hydrolysis to hematite) is not currently constrained. By analogy, a formation pathway for the hematite spherules in sulfate-rich outcrops at Meridiani Planum on Mars (the Burns formation) is aqueous alteration of basaltic precursor material under acid-sulfate conditions. Although hydrothermal conditions are present on Mauna Kea, such conditions may not be required for spherule formation on Mars if the time interval for hydrolysis at lower temperatures is sufficiently long.

Morris, R. V.; Ming, D. W.; Graff, T. G.; Arvidson, R. E.; Bell, J. F., III; Squyres, S. W.; Mertzman, S. A.; Gruener, J. E.; Golden, D. C.; Robinson, G. A.

2005-01-01

201

Synthetic heat at mild temperatures.  

PubMed

"Synthetic heat", also known as the heat grill illusion, occurs when contact with spatially adjacent warm and cold stimuli produce a sensation of "heat". This phenomenon has been explained as a painful perception that occurs when warm stimulation inhibits cold-sensitive neurons in the spinothalamic tract (STT), which in turn unmasks activity in the pain pathway caused by stimulation of C-polymodal nociceptors (CPNs). The "unmasking model" was tested in experiment 1 by combining warm (35-40 degrees C) and cool (> or = 27 degrees C) stimuli that were too mild to stimulate CPNs. After discovering that these temperatures produced nonpainful heat, experiment 2 was designed to determine whether heat could be induced when near-threshold cooling was paired with mild warmth, and whether lowering the base temperature for cooling would increase the noxious (burning, stinging) components of heat for fixed cooling steps of 1-3 degrees C. Cooling by just 1 degrees C from a base temperature of 33 degrees C led to reports of heat on more than 1/3 of trials, and cooling by just 3 degrees C evoked heat on 75% of trials. Lowering the base temperature to 31 or 29 degrees C increased reports of heat and burning but did not produce significant reports of pain. Perception of nonpainful heat at such mild temperatures indicates either that cold-sensitive nociceptors with thresholds very similar to cold fibers innervate hairy skin in humans, or that heat can result from integration of warm fiber and cold fiber activity, perhaps via convergence on nonspecific (e.g., WDR) neurons in the STT. PMID:12088387

Green, Barry G

2002-01-01

202

[Mild Cognitive Impairment: potential therapeutics].  

PubMed

Mild Cognitive Impairment (MCI) is an emerging concept used to describe memory decline and probably attention disturbances in otherwise intellectually intact individuals. MCI may be considered in 12 to 15 p. 100 of the cases as announcing an Alzheimer's Disease (AD). Although still speculative, the debate concerning the drugs susceptible to normalize symptoms of MCI or to stop conversion to AD must be raised. For that purpose, several long term clinical trials are running (antioxidants, nootropics, anticholinesterasics.) and new molecules in the pipe-line should be assessed in patients with the diagnosis of MCI. PMID:12529584

Allain, H; Bentue-Ferrer, D; Belliard, S; Reymann, J-M; Djemaï, M; Merienne, M

2002-01-01

203

ENCOAL Mild Coal Gasification Project  

SciTech Connect

ENCOAL Corporation, a wholly-owned subsidiary of Shell Mining Company, is constructing a mild gasification demonstration plant at Triton Coal Company's Buckskin Mine near Gillette, Wyoming. The process, using Liquids From Coal (LFC) technology developed by Shell and SGI International, utilizes low-sulfur Powder River Basin Coal to produce two new fuels, Process Derived Fuel (PDF) and Coal Derived Liquids (CDL). The products, as alternative fuels sources, are expected to significantly reduce current sulfur emissions at industrial and utility boiler sites throughout the nation, thereby reducing pollutants causing acid rain.

Not Available

1992-02-01

204

Development of an advanced continuous mild gasification process for the production of coproducts. Final report  

SciTech Connect

This report is a final brief summary of development of a mild-gasification and char conversion process. Morgantown Energy Technology Center developed a concept called mild gasification. In this concept, devolatilization of coal under nonoxidizing and relatively mild temperature and pressure conditions can yield three marketable products: (1) a high-heating-value gas, (2) a high-aromatic coal liquid, and (3) a high-carbon char. The objective of this program is to develop an advanced, continuous, mild-gasification process to produce products that will make the concept economically and environmentally viable. (VC)

Merriam, N.W.; Jha, M.C.

1991-11-01

205

Development of an advanced continuous mild gasification process for the production of coproducts  

SciTech Connect

This report is a final brief summary of development of a mild-gasification and char conversion process. Morgantown Energy Technology Center developed a concept called mild gasification. In this concept, devolatilization of coal under nonoxidizing and relatively mild temperature and pressure conditions can yield three marketable products: (1) a high-heating-value gas, (2) a high-aromatic coal liquid, and (3) a high-carbon char. The objective of this program is to develop an advanced, continuous, mild-gasification process to produce products that will make the concept economically and environmentally viable. (VC)

Merriam, N.W.; Jha, M.C.

1991-11-01

206

Synchrotron emissivity from mildly relativistic particles  

NASA Technical Reports Server (NTRS)

Approximate analytic expressions are presented for evaluation of the frequency and angular dependence of synchrotron emissivity from mildly relativistic particles with arbitrary energy spectrum and pitch angle distribution in a given magnetic field. Results agree with previous expressions for a nonrelativistic Maxwellian particle distribution, and when extrapolated to nonrelativistic and extreme relativistic regimes, they also agree with the previous expressions obtained under those limiting conditions. The results from the analytic expression are compared with results from detailed numerical evaluations. Excellent agreement is found not only at frequencies large compared to the gyro-frequency but also at lower frequencies, in fact, all the way down to the gyro-frequency, where the analytic approximations are expected to be less accurate.

Petrosian, V.

1981-01-01

207

Numerical study of mild combustion in hot diluted diffusion ignition (HDDI) regime  

Microsoft Academic Search

Mild Combustion is a process defined on the ground of well-identified external parameters, namely the temperature of reactants and the maximum allowable temperature increase. Although the definition is rigorous, it is necessary to identify unique, intrinsic structural properties of processes evolving in such conditions in the different, basic configurations that make Mild Combustion relevant from practical point of view.In this

M. de Joannon; P. Sabia; G. Sorrentino; A. Cavaliere

2009-01-01

208

Coordination modes of multidentate ligands in fac-[Re(CO)(3)(polyaminocarboxylate)] analogues of (99m)Tc radiopharmaceuticals. dependence on aqueous solution reaction conditions.  

PubMed

We study Re analogues of (99m)Tc renal agents to interpret previous results at the (99m)Tc tracer level. The relative propensities of amine donors versus carboxylate oxygen donors of four L = polyaminocarboxylate ligands to coordinate in fac-[Re(I)(CO)(3)L](n) complexes were assessed by examining the reaction of fac-[Re(I)(CO)(3)(H(2)O)(3)](+) under conditions differing in acidity and temperature. All four L [N,N-bis-(2-aminoethyl)glycine (DTGH), N,N-ethylenediaminediacetic acid, diethylenetriamine-N-malonic acid, and diethylenetriamine-N-acetic acid] can coordinate as tridentate ligands while creating a dangling chain terminated in a carboxyl group. Dangling carboxyl groups facilitate renal clearance in fac-[(99m)Tc(I)(CO)(3)L](n) agents. Under neutral conditions, the four ligands each gave two fac-[Re(I)(CO)(3)L](n) products with HPLC traces correlating well with known traces of the fac-[(99m)Tc(I)(CO)(3)L](n) mixtures. Such mixtures are common in renal agents because the needed dangling carboxyl group can compete for a coordination site. However, the HPLC separations needed to assess the biodistribution of a single tracer are impractical in a clinical setting. One goal in investigating this Re chemistry is to identify conditions for avoiding this problem of mixtures in preparations of fac-[(99m)Tc(I)(CO)(3)L](n) renal tracers. After separation and isolation of the fac-[Re(I)(CO)(3)L](n) products, NMR analysis of all products and single crystal X-ray crystallographic analysis of both DTGH products, as well as one product each from the other L, allowed us to establish coordination mode unambiguously. The product favored in acidic conditions has a dangling amine chain and more bound oxygen. The product favored in basic conditions has a dangling carboxyl chain and more bound nitrogen. At the elevated temperatures used for simulating tracer preparation, equilibration was facile (ca. 1 h or less), allowing selective formation of one product by utilizing acidic or basic conditions. The results of this fundamental study offer protocols and guidance useful for the design and preparation of fac-[(99m)Tc(I)(CO)(3)L](n) agents consisting of a single tracer. PMID:20201565

Lipowska, Malgorzata; He, Haiyang; Xu, Xiaolong; Taylor, Andrew T; Marzilli, Patricia A; Marzilli, Luigi G

2010-04-01

209

Coordination Modes of Multidentate Ligands in fac-[Re(CO)3(polyaminocarboxylate)] Analogues of 99mTc Radiopharmaceuticals. Dependence on Aqueous Solution Reaction Conditions  

PubMed Central

We study Re analogues of 99mTc renal agents to interpret previous results at the 99mTc tracer level. The relative propensities of amine donors vs. carboxylate oxygen donors of four L = polyaminocarboxylate ligands to coordinate in fac-[ReI(CO)3L]n complexes were assessed by examining the reaction of fac-[ReI(CO)3(H2O)3]+ under conditions differing in acidity and temperature. All four L [N,N-bis-(2-aminoethyl)glycine (DTGH), N,N-ethylenediaminediacetic acid, diethylenetriamine-N-malonic acid, and diethylenetriamine-N-acetic acid] can coordinate as tridentate ligands while creating a dangling chain terminated in a carboxyl group. Dangling carboxyl groups facilitate renal clearance in fac-[99mTcI(CO)3L]n agents. Under neutral conditions, the four ligands each gave two fac-[ReI(CO)3L]n products with HPLC traces correlating well with known traces of the fac-[99mTcI(CO)3L]n mixtures. Such mixtures are common in renal agents because the needed dangling carboxyl group can compete for a coordination site. However, the HPLC separations needed to assess the biodistribution of a single tracer are impractical in a clinical setting. One goal in investigating this Re chemistry is to identify conditions for avoiding this problem of mixtures in preparations of fac-[99mTcI(CO)3L]n renal tracers. After separation and isolation of the fac-[ReI(CO)3L]n products, NMR analysis of all products and single crystal X-ray crystallographic analysis of both DTGH products as well as one product each from the other L allowed us to establish coordination mode unambiguously. The product favored in acidic conditions has a dangling amine chain and more bound oxygen. The product favored in basic conditions has a dangling carboxyl chain and more bound nitrogen. At the elevated temperatures used for simulating tracer preparation, equilibration was facile (ca. one hour or less), allowing selective formation of one product by utilizing acidic or basic conditions. The results of this fundamental study offer protocols and guidance useful for the design and preparation of fac-[99mTcI(CO)3L]n agents consisting of a single tracer.

Lipowska, Malgorzata; He, Haiyang; Xu, Xiaolong; Taylor, Andrew T.; Marzilli, Patricia A.; Marzilli, Luigi G.

2010-01-01

210

Consumer preferences for mild cheddar cheese flavors.  

PubMed

Flavor is an important factor in consumer selection of cheeses. Mild Cheddar cheese is the classification used to describe Cheddar cheese that is not aged extensively and has a "mild" flavor. However, there is no legal definition or age limit for Cheddar cheese to be labeled mild, medium, or sharp, nor are the flavor profiles or flavor expectations of these cheeses specifically defined. The objectives of this study were to document the distinct flavor profiles among commercially labeled mild Cheddar cheeses, and to characterize if consumer preferences existed for specific mild Cheddar cheese flavors or flavor profiles. Flavor descriptive sensory profiles of a representative array of commercial Cheddar cheeses labeled as mild (n= 22) were determined using a trained sensory panel and an established cheese flavor sensory language. Nine representative Cheddar cheeses were selected for consumer testing. Consumers (n= 215) assessed the cheeses for overall liking and other consumer liking attributes. Internal preference mapping, cluster analysis, and discriminant analysis were conducted. Mild Cheddar cheeses were diverse in flavor with many displaying flavors typically associated with more age. Four distinct consumer clusters were identified. The key drivers of liking for mild Cheddar cheese were: color, cooked/milky, whey and brothy flavors, and sour taste. Consumers have distinct flavor and color preferences for mild Cheddar cheese. These results can help manufacturers understand consumer preferences for mild Cheddar cheese. PMID:19021820

Drake, S L; Gerard, P D; Drake, M A

2008-11-01

211

Effect of aqueous LiBr solutions on the corrosion resistance and galvanic corrosion of an austenitic stainless steel in its welded and non-welded condition  

Microsoft Academic Search

The corrosion resistance and galvanic behaviour of a highly alloyed austenitic stainless steel (UNS N08031) and a nickel–base alloy (UNS N06059) in its welded (GTAW) and non-welded condition were analysed in LiBr solutions by means of electrochemical measurements. Samples microstructure was studied by SEM and EDX analysis. The alloys considered showed passive behaviour and they were able to repassivate after

E. Blasco-Tamarit; A. Igual-Muñoz; J. García Antón; D. García-García

2006-01-01

212

Mild conditions for Pd-catalyzed carboamination of N-protected hex-4-enylamines and 1-, 3-, and 4-substituted pent-4-enylamines. Scope, limitations, and mechanism of pyrrolidine formation.  

PubMed

The use of the weak base Cs2CO3 in Pd-catalyzed carboamination reactions of N-protected gamma-aminoalkenes with aryl bromides leads to greatly increased tolerance of functional groups and alkene substitution. Substrates derived from (E)- or (Z)-hex-4-enylamines are stereospecifically converted to 2,1'-disubstituted pyrrolidine products that result from suprafacial addition of the nitrogen atom and the aryl group across the alkene. Transformations of 4-substituted pent-4-enylamine derivatives proceed in high yield to afford 2,2-disubstituted products, and cis-2,5- or trans-2,3-disubstituted pyrrolidines are generated in good yield with excellent diastereoselectivity from N-protected pent-4-enylamines bearing substituents at C1 or C3. The reactions tolerate a broad array of functional groups, including esters, nitro groups, and enolizable ketones. The scope and limitations of these transformations are described in detail, along with models that account for the observed product stereochemistry. In addition, deuterium labeling experiments, which indicate these reactions proceed via syn-aminopalladation of intermediate palladium(aryl)(amido)complexes regardless of degree of alkene substitution or reaction conditions, are also discussed. PMID:18942792

Bertrand, Myra Beaudoin; Neukom, Joshua D; Wolfe, John P

2008-11-21

213

Reaction mechanism for the aqueous-phase mineral carbonation of heat-activated serpentine at low temperatures and pressures in flue gas conditions.  

PubMed

Mineral carbonation is known as one of the safest ways to sequester CO2. Nevertheless, the slow kinetics and low carbonation rates constitute a major barrier for any possible industrial application. To date, no studies have focused on reacting serpentinite with a relatively low partial pressure of CO2 (pCO2) close to flue gas conditions. In this work, finely ground and heat-treated serpentinite [Mg3Si2O5(OH)4] extracted from mining residues was reacted with a 18.2 vol % CO2 gas stream at moderate global pressures to investigate the effect on CO2 solubility and Mg leaching. Serpentinite dissolution rates were also measured to define the rate-limiting step. Successive batches of gas were contacted with the same serpentinite to identify surface-limiting factors using scanning electron microscopy (SEM) analysis. Investigation of the serpentinite carbonation reaction mechanisms under conditions close to a direct flue gas treatment showed that increased dissolution rates could be achieved relative to prior work, with an average Mg dissolution rate of 3.55 × 10(-11) mol cm(-2) s(-1). This study provides another perspective of the feasibility of applying a mineral carbonation process to reduce industrial greenhouse gas (GHG) emissions from large emission sources. PMID:24669999

Pasquier, Louis-César; Mercier, Guy; Blais, Jean-François; Cecchi, Emmanuelle; Kentish, Sandra

2014-05-01

214

Too Hard to Control: Compromised Pain Anticipation and Modulation in Mild Traumatic Brain Injury.  

National Technical Information Service (NTIS)

Mild traumatic brain injury (MTBI) is a vulnerability factor for the development of pain-related conditions above and beyond those related to comorbid traumatic and emotional symptoms. We acquired functional magnetic resonance imaging (fMRI) on a validate...

A. D. Spadoni A. N. Simmons I. A. Strigo J. Lohr

2014-01-01

215

Semantic interference deficits and the detection of mild Alzheimer's disease and mild cognitive impairment without dementia  

Microsoft Academic Search

Impairment in delayed recall has traditionally been considered a hallmark feature of Alzheimer's disease (AD). However, vulnerability to semantic interference may reflect early manifestations of the disorder. In this study, 26 mildly demented AD patients (mild AD), 53 patients with mild cognitive impairment without dementia (MCI), and 53 normal community-dwelling elders were first presented 10 common objects that were recalled

DAVID A. LOEWENSTEIN; AMARILIS ACEVEDO; CHERYL LUIS; THOMAS CRUM; WARREN W. BARKER; RANJAN DUARA

2004-01-01

216

Mild gasification mechanisms and char conversion  

SciTech Connect

The purpose of these programs is to (1) obtain basic process chemistry data for the mild gasification of various coal types in a stirred moving bed reactor as a function of process variables and (2) construct a countercurrent moving bed reactor for obtaining data on the hydrogasification of char resulting from mild gasification. Results are described. 2 refs., 7 figs., 8 tabs.

Steinberg, M.; Fallon, P.T.; Sundaram, M.S.

1989-06-01

217

Mission Connect Mild TBI Translational Research Consortium.  

National Technical Information Service (NTIS)

Mild traumatic brain injury (mTBI), particularly mild blast injuries due to improvised exploding devices, result in long term impairment of cognition and behavior. Our hypothesis is that there are inflammatory consequences to mTBI that persist over time a...

C. E. Hulsebosch D. S. DeWitt J. R. Perez-Polo R. J. Grill

2012-01-01

218

Current Concepts in Mild Cognitive Impairment  

Microsoft Academic Search

he field of aging and dementia is focusing on the characterization of the earliest stages of cognitive impairment. Recent research has identified a transitional state between the cognitive changes of normal aging and Alzheimer's disease (AD), known as mild cognitive impairment (MCI). Mild cognitive impairment refers to the clinical condi- tion between normal aging and AD in which persons experience

Ronald C. Petersen; Rachelle Doody; Alexander Kurz; Richard C. Mohs; John C. Morris; Peter V. Rabins; Karen Ritchie; Martin Rossor; Leon Thal; Bengt Winblad

1999-01-01

219

Amidation of multiwalled carbon nanotubes in mild and efficient conditions.  

PubMed

Functionalization of Multi Walled Carbon Nanotubes (MWCNTs) with amines under a two step reaction is studied. In the first step, maleic anhydride graft to the MWCNT (Mah-g-MWCNTs) surfaces via a polymerization process with benzoylproxide as initiator. Active anhydride groups on the surfaces of MWCNTs, react with amines to give a polyamido chain attached to the MWCNTs surfaces. The reaction products have high solubility and disperse stability in organic solvents. FTIR, TGA and elemental analysis (CHN) were used to characterization of the achieved products. PMID:23755621

Moradi, Leila; Mohajeri, Ali; Naeimi, Hossein; Rashidi, Ali Morad

2013-03-01

220

An extremely rapid, convenient and mild coal desulfurization new process: Sodium borohydride reduction  

Microsoft Academic Search

The present work describes the desulfurization of coal using mildly reductive method. Both a Yanzhou and a Yanshan coal (referred to as YZ and YS coal, respectively), were treated in an aqueous media employing sodium borohydride (NaBH4) as reducing agent, which is a well known hydrogen storage. Reaction variables investigated include concentration of reductant, time, pH of initial media, temperature,

Zhiling Li; Tonghua Sun; Jinping Jia

2010-01-01

221

Influence of 2,3-Dihydroxyflavanone on Corrosion Inhibition of Mild Steel in Acidic Medium  

NASA Astrophysics Data System (ADS)

The inhibition effect of 2,3-dihydroxyflavone on the corrosion of mild steel in 100-600 ppm aqueous hydrochloric acid solution has been investigated by weight loss and electrochemical impedance spectroscopy. The corrosion inhibition efficiency increases with increasing concentration and time. The effect of temperature on the corrosion behavior of mild steel in 1 M HCl with addition of inhibitor was studied at the temperature range of 300-330 K. UV-Vis, FTIR, and surface analysis (SEM) was also carried out to establish the corrosion inhibitive property of this inhibitor in HCl solution. The adsorption of this inhibitor on the mild steel surface obeys the Langmuir adsorption isotherm. Electrochemical studies reveal that the inhibitor is a cathodic type.

Gopiraman, M.; Sathya, C.; Vivekananthan, S.; Kesavan, D.; Sulochana, N.

2012-02-01

222

QD-antibody conjugates via carbodiimide-mediated coupling: a detailed study of the variables involved and a possible new mechanism for the coupling reaction under basic aqueous conditions.  

PubMed

A detailed study into the optimization of carbodiimide-mediated coupling of antibodies (Ab) and quantum dots (QD) for use in cellular imaging has been undertaken. This involved the grafting of commercially available carboxyl-modified QDs (Evident Technologies "Lake Placid Blue" Evitag and eBioscience's eflour nanocrystals) with anti-Cdc8 Abs to produce conjugates with specific affinity for fission yeast tropomyosin Cdc8 protein. The water-soluble carbodiimide 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) was used to activate the QDs prior to their incubation with antibody, and a range of QD-carboxyl/EDC/Ab mole ratios were used in the experiments in attempts to optimize fluorescence and bioaffinity of the conjugate products (EDC to QD-carboxyl-600 nmol/15 pmol to 0.12 nmol/15 pmol and QD to Ab 120 pmol/24 pmol to 120 pmol/1.2 pmol). It was observed that a specific "optimum" ratio of the three reactants was required to produce the most fluorescent and biologically active product and that it was generated at alkaline pH 10.8. Increasing the ratio of Ab to QD produced conjugate which was less fluorescent while reducing the ratio of EDC to QD in the activation step led to increased fluorescence of product. Conjugates were tested for their possession of antibody by measurement of their absorption at OD(280 nm) and for their fluorescence by assay ?(max(em)) at 495 nm. A quantitative assay of the bioactivity of the conjugates was developed whereby a standardized amount of Cdc8 antigen was spotted onto nylon membranes and reacted with products from conjugation reactions in a sandwich-type colormetric assay The "best" conjugate was used in intracellular imaging of yeast Cdc8 protein and produced brighter, higher definition images of fixed yeast cell actin structure than a fluorescein-Ab conjugate routinely produced in our laboratory. The QD-Ab conjugate was also significantly more resistant to photobleaching than the fluorescein-Ab conjugate. Results from other experiments involving EDC, the water-soluble carbodiimide 1-cyclohexyl-3-(2-morpholinoethyl)carbodiimide metho-p-toluenesulphonate (CMC), and EDC.HCl have suggested a new reaction mechanism for EDC coupling under basic aqueous conditions. In summary, a robust understanding of commercial QD-COOH surface chemistry and the variables involved in the materials' efficient conjugation with a bioligand using carbidiimide has been obtained along with an optimized approach for Ab-QD conjugate production. A novel assay has been developed for bioassay of QD-Ab conjugates and a new mechanism for EDC coupling under basic aqueous conditions is proposed. PMID:21970592

East, Daniel A; Mulvihill, Daniel P; Todd, Michael; Bruce, Ian J

2011-11-15

223

Non syndromic gingival fibromatosis in a mild mental retardation child  

PubMed Central

Gingival fibromatosis is a benign oral condition characterized by enlargement of gingival tissues. It usually develops as an isolated disorder but can be one of the features of a syndrome. This case report is of a 5-year-old male with severe gingival hyperplasia and mild mental retardation which was complicated by open bite, abnormal occlusion, open lip posture, and disabilities associated with mastication and speech. Full mouth gingivectomy in single sitting under general anesthesia was done with electrocautery.

Duddu, Mahesh K.; Muppa, Radhika; Reddy, G. S. Prasad; Reddy, P. Veerendra Nath

2012-01-01

224

Differential Working Memory Load Effects after Mild Traumatic Brain Injury  

Microsoft Academic Search

The objective of this study was to explore the effects of increasing working memory (WM) processing load on previously observed abnormalities in activation of WM circuitry shortly after mild traumatic brain injury (MTBI). Brain activation patterns in response to increasing WM processing load (auditory n-back: 0-, 1-, 2-, and 3-back conditions) were assessed with fMRI in 18 MTBI patients within

Thomas W. McAllister; Molly B. Sparling; Laura A. Flashman; Stephen J. Guerin; Alexander C. Mamourian; Andrew J. Saykin

2001-01-01

225

Current treatment options for depression after mild traumatic brain injury  

Microsoft Academic Search

Opinion statement  Mild traumatic brain injury (MTBI) is the most common neurologic condition in the United States; about 503 of every 100,000\\u000a persons visiting the emergency department have this diagnosis. A complex cluster of neurologic signs and symptoms are associated\\u000a with an acceleration-deceleration mechanism of injury. Unfortunately, many persons do not seek treatment for MTBI. Depression\\u000a following MTBI adds to the

Esther Bay

2009-01-01

226

Mild Nonoxidative Procedure for the Hydrolysis of Dimethylhydrazones  

Microsoft Academic Search

The past decade has seen amsiderable utilization of dkthylhyldrazones in organic synthesis. Their use as carbonyl equivalents depends on the ability of the practitioner to achieve hydrolylsis under mild conditions. Raagenta previously reported to acanplish this end include acid hydrolysis, methylation and hydrolysis, O3 , CH3C03H, NaI04 , Cu(OAc)2 , CoF3 , NOBF4 , MoF6 , MoOCl3 , UF6 ,

Robert E. Gawley; Enrico J. Termine

1982-01-01

227

The fate of sulfur in mild gasification liquids  

SciTech Connect

This investigation addresses the determination of sulfur distribution in mild gasification liquids produced from untreated coal and from modified in two ways to reduce sulfur in the products: (a) physical mixing with a sulfur scavenger (CaO), and (b) pretreatment with aqueous alkali followed by mixing with CaO. Coal pyrolysis in the presence of CaO has previously been investigated, (3,5) showing that CaO can be effective in reducing the sulfur content of the fuel gas, and possibly that of the product liquids. Pretreatment of coals with alkaline chemicals has also been studied,(6,7) showing reduced sulfur and other changes in the liquid products.(8) Data on sulfur distribution in the liquid products could be useful for understanding the chemistry of alkali pretreatment and CaO interaction with coal sulfur during pyrolysis. In this work, a pyrolysis-gas chromatography (Py-GC) technique that simulates mild gasification on a milligram scale was used in conjunction with a carbon-specific flame ionization detector (FID) and a sulfur-specific flame photometric detector (FPD) to determine the sulfur distribution in oils/tars from Illinois No. 6 coal. A low-resolution packed GC column was employed to resolve oils/tars by carbon number, with ranges selected to approximate distillation fractions which might be recovered from a commercial mild gasification process. Oils/tars up to C{sub 18} were also collected from the pyro-probe effluent into dichloromethane for off-line study using a high-resolution GC with atomic emission detector (GC/AED) and with GC-mass spectrometry (GC/MS) to measure specific sulfur compounds. 9 refs., 1 tab.

Knight, R.A.; Koncar, G.J.; Babu, S.P.

1991-01-01

228

Preparation conditions and optical properties of rare earth ion (Er{sup 3+} and Eu{sup 3+})-doped alumina films by the aqueous sol{endash}gel method  

SciTech Connect

Transparent alumina and rare earth ion (Er{sup 3+} and Eu{sup 3+}) highly doped alumina films (15 mol%) were prepared by the aqueous sol{endash}gel method, in order to examine the effects of various preparation conditions on the structure and optical properties of doped films. The results showed that when the gel was heat treated, it lost free and bound water and was converted into the oxide by way of a series of intermediate phases although the oxide as a whole remained structureless. The thermogravimetric analysis curve showed a marked weight loss in the temperature range of 100{endash}500{degree}C and the slow loss continuing at higher temperature of 800{degree}C. High doping may reflect noncrystalline structure of alumina. The fluorescence of Eu{sup 3+} sensitive of microstructure increased especially corresponding to this weight loss with treatment. The {Omega}{sub 2} indicative of the asymmetric environment of Er{sup 3+} showed a similar increase. Concentration quenching for doped films treated at 800{degree}C was not significant in this concentration range. Lifetimes increased with increasing treatment temperature, similar to above increase. {copyright} 2001 American Institute of Physics.

Ishizaka, T.; Kurokawa, Y.

2001-07-01

229

Lithium Ion Aqueous Cells.  

National Technical Information Service (NTIS)

Lithium ion aqueous cells were investigated using lithium intercalating compounds as anodes and cathodes. The aqueous electrolyte consisted of 4 to 5 molar solutions of either lithium perchlorate or lithium nitrate which contained lithium hydroxide in mil...

E. J. Plichta W. K. Behl

1995-01-01

230

Mukaiyama Aldol Reactions in Aqueous Media  

PubMed Central

Mukaiyama aldol reactions in aqueous media have been surveyed. While the original Mukaiyama aldol reactions entailed stoichiometric use of Lewis acids in organic solvents under strictly anhydrous conditions, Mukaiyama aldol reactions in aqueous media are not only suitable for green sustainable chemistry but are found to produce singular phenomena. These findings led to the discovery of a series of water-compatible Lewis acids such as lanthanide triflates in 1991. Our understanding on these beneficial effects in the presence of water will be deepened through the brilliant examples collected in this review. 1 Introduction 2 Rate Enhancement by Water in the Mukaiyama Aldol Reaction 3 Lewis Acid Catalysis in Aqueous or Organic Solvents 3.1 Water-Compatible Lewis Acids 4 Lewis-Base Catalysis in Aqueous or Organic Solvents 5 The Mukaiyama Aldol Reactions in 100% Water 6 Asymmetric Catalysts in Aqueous Media and Water 7 Conclusions and Perspective

Kitanosono, Taku; Kobayashi, Shu

2013-01-01

231

Concussion and Mild Traumatic Brain Injury  

MedlinePLUS

... page: About CDC.gov . Injury Prevention & Control : Traumatic Brain Injury CDC's Injury Center Share Compartir Concussion and Mild ... Concussion? A concussion is a type of traumatic brain injury (TBI) caused by a bump, blow, or jolt ...

232

Montelukast as monotherapy in children with mild persistent asthma.  

PubMed

The cysteinyl leukotrienes cause bronchoconstriction, increased mucus production and airway inflammation, three major features of asthma. Several randomized controlled trials have shown the efficacy of leukotriene receptor antagonists for improving asthma outcomes. The drug is favored for treating childhood asthma, where poor compliance with inhalation therapy is a therapeutic challenge. To assess the effectiveness of Montelukast in asthmatic children under real-life conditions, a prospective, single-arm, multicenter, open-label observational study was performed on asthmatic children 2- to 14-years-old with a history of physician-diagnosed mild persistent asthma. Montelukast was given once daily for 12 consecutive weeks. By the end a significant improvement of the daytime asthma symptom score, nighttime asthma score, peak expiratory flow rate (PEFR) and mean score of the investigators' global evaluation was noted (p < 0.05). These results suggest that montelukast is an effective monotherapy controller in children with mild persistent asthma. PMID:20232571

Wu, Wei-Fong; Wu, Jiunn-Ren; Dai, Zen-Kong; Tsai, Chin-Wen; Tsai, Tzu-Chun; Chen, Chia-Chun; Yang, Chueh-Yuan

2009-12-01

233

A new approach to the oxidational theory of mild wear  

NASA Technical Reports Server (NTRS)

The wear and friction of 316 stainless steel was investigated in relation to oxidation at the real area of contact. An approach describing the oxidation characteristics of mild wear in terms of linear oxidation kinetics is presented. Linear oxidation kinetics more closely approaches the physical conditions involved where oxide growth on asperities is continuously interrupted by spalling and removal. The mild wear rate may now be described mathematically by two empirical equations in terms of the operational variables and the oxidational constants without using the critical oxide thickness, which is dependent on asperity size, shape and temperature, and is difficult to measure. The resulting activation energy for oxidational wear was significantly lower than that for static oxidation governed by diffusion controlled kinetics.

Hong, H.; Hochman, R. F.; Quinn, T. F. J.

1988-01-01

234

Submerged arc fillet welds between mild steel and stainless steel  

SciTech Connect

Submerged arc fillet welds between mild steel and Type 304 stainless steel, made with ER309L wire, may contain no ferrite and be at risk of hot cracking, or they may be sufficiently diluted that they transform to martensite with both hot cracking risk and low ductility. This situation is most prevalent when direct current electrode positive (DCEP) polarity is used and when the flange is the mild steel part of the T-joint. A flux that adds chromium to the weld can somewhat alleviate this tendency. Direct current electrode negative (DCEN) polarity greatly reduces this tendency by limiting dilution. Fillet weld compositions and dilutions are obtained for a number of welding conditions and fluxes.

Kotecki, D.J.; Rajan, V.B. [Lincoln Electric Co., Cleveland, OH (United States)

1997-02-01

235

Micronutrient supplementation in mild Alzheimer disease patients  

Microsoft Academic Search

Objective: To evaluate if nutritional supplementation with or without micronutrient enhancement prevent weight loss and the progression of the disease in mild Alzheimer's Disease (AD) patients.Design: Mild AD patients were recruited from an Alzheimer Day Centre. Subjects received oral liquid supplements with (Study-group: S) or without (Control-group: C) micronutrient enhancement. Intake assessment, nutritional status, biochemical parameters, cognitive function, and eating

M Planas; M Conde; S Audivert; C Pérez-Portabella; R Burgos; P Chacón; J Rossello; M Boada; L. L Tàrraga

2004-01-01

236

Effect of electrolyte and monomer concentration on anticorrosive properties of poly( N-methylaniline) and poly( N-ethylaniline) coated mild steel  

Microsoft Academic Search

The electrosynthesis of poly(N-methylaniline) (PNMA) and poly(N-ethylaniline) (PNEA) coatings on mild steel in aqueous oxalic acid solutions was carried out by potentiodynamic synthesis technique. The effects of monomer and electrolyte concentrations on electrochemical growth of PNMA and PNEA coatings on mild steel substrates were investigated. Repassivation peak did not appear during electrosynthesis of PNMA and PNEA coatings from solutions containing

Aziz Ya?an; Nuran Özçiçek Pekmez; Attila Y?ld?z

2006-01-01

237

Transcriptomic Analysis of Mild Hypothermia-dependent Alterations During Endothelial Reperfusion Injury  

Microsoft Academic Search

Background: Mild hypothermia (32-34°C) improves resistance to ischemia-reperfusion (I\\/R) injury. However, the mechanisms by which it affects human cellular function are not fully elucidated. To further test for hypothermic modulation of global biological processes, we used DNA microarray technique to detect the overall gene expression profile. Methods: Human umbilical endothelial cells (HUVECs) were incubated under control condition (37°C) or mild

Dan Yang; Yong Zeng; Cui Tian; Jing Liu; Shu-Bin Guo; Yue-Hong Zheng; Hui-Hua Li

2010-01-01

238

Chemical reactivities of hafnium and its derived boride, carbide and nitride compounds at relatively mild temperature  

Microsoft Academic Search

MB2\\/SiC composites are materials of choice for ultra-high-temperature structural applications, primarily in the aerospace arena. These composites are processed in a hot-press operation at a temperature range of 1900 to 2200°C. This article assesses potential “mild-temperature” (below 1500°C) chemical reactions that may lead to structures and coatings made of HfB2\\/SiC under pressureless or mild-pressure conditions. The reactions are anticipated to

Y. D. Blum; H.-J. Kleebe

2004-01-01

239

Blood biomarkers of osteoporosis in mild cognitive impairment and Alzheimer’s disease  

Microsoft Academic Search

Previous studies revealed some comorbidity of Alzheimer’s disease and osteoporosis not only for advanced disease, but also\\u000a for the incipient conditions cognitive decline and decline of bone mineral density. To detect comorbidity with osteoporosis\\u000a at a subclinical level, we studied concentrations of biochemical osteoporosis markers in blood plasma of subjects with mild\\u000a cognitive impairment and mild Alzheimer’s disease compared to

Christian Luckhaus; Bijan Mahabadi; Brigitte Grass-Kapanke; Michaela Jänner; Holger Willenberg; Marcus Jäger; Tillmann Supprian; Karin Fehsel

2009-01-01

240

A retrospective comparative study evaluating the results of mild hyperthermic versus controlled normothermic perfusion for recurrent melanoma of the extremities  

Microsoft Academic Search

The aim of this study was to investigate the role of mild hyperthermia (39–40 °C) in isolated cytostatic perfusion for patients with recurrent melanoma of the extremities. A total of 218 patients treated with mild hyperthermic perfusion was compared to 166 patients perfused under controlled normothermic conditions (37–38 °C). Only patients whose lesions had been excised before or at the

J. M. Klaase; B. B. R. Kroon; A. M. M. Eggermont; A. N. van Geel; H. Schraffordt Koops; J. Oldhoff; D. Liénard; F. J. Lejeune; R. Berkel; H. R. Franklin; A. A. M. Hart

1995-01-01

241

Evidence for a Morin Type Intramolecular Cyclization of an Alkene with a Phenylsulfenic Acid Group in Neutral Aqueous Solution  

PubMed Central

Sulfenic acids (RSOH) are among the most common sulfur-centered reactive intermediates generated in biological systems. Given the biological occurrence of sulfenic acids, it is important to explore the reactivity of these intermediates under physiological conditions. The Morin rearrangement is a synthetic process developed for the conversion of penicillin derivatives into cephalosporins that proceeds via nucleophilic attack of an alkene on a sulfenic acid intermediate. In its classic form, the Morin reaction involves initial elimination of a sulfenic acid from a cyclic sulfoxide, followed by intramolecular cyclization of the resulting alkene and sulfenic acid groups to generate an episulfonium ion intermediate that undergoes further reaction to yield ring-expanded products. On the basis of the existing literature, it is difficult to assess whether the reaction between an alkene and a sulfenic group can occur under mild conditions because the conditions required to generate the sulfenic acid from the sulfoxide precursor in the Morin reaction typically involve high temperatures and strong acid. In the work described here, ?-sulfinylketone precursors were used to generate a “Morin type” sulfenic acid intermediate under mild conditions. This approach made it possible to demonstrate that the intramolecular cyclization of an alkene with a phenylsulfenic acid to generate an episulfonium ion intermediate can occur in neutral aqueous solution at room temperature.

Keerthi, Kripa; Sivaramakrishnan, Santhosh; Gates, Kent S.

2009-01-01

242

Chemical reactions at aqueous interfaces  

NASA Astrophysics Data System (ADS)

Interfaces or phase boundaries are a unique chemical environment relative to individual gas, liquid, or solid phases. Interfacial reaction mechanisms and kinetics are often at variance with homogeneous chemistry due to mass transfer, molecular orientation, and catalytic effects. Aqueous interfaces are a common subject of environmental science and engineering research, and three environmentally relevant aqueous interfaces are investigated in this thesis: 1) fluorochemical sonochemistry (bubble-water), 2) aqueous aerosol ozonation (gas-water droplet), and 3) electrolytic hydrogen production and simultaneous organic oxidation (water-metal/semiconductor). Direct interfacial analysis under environmentally relevant conditions is difficult, since most surface-specific techniques require relatively `extreme' conditions. Thus, the experimental investigations here focus on the development of chemical reactors and analytical techniques for the completion of time/concentration-dependent measurements of reactants and their products. Kinetic modeling, estimations, and/or correlations were used to extract information on interfacially relevant processes. We found that interfacial chemistry was determined to be the rate-limiting step to a subsequent series of relatively fast homogeneous reactions, for example: 1) Pyrolytic cleavage of the ionic headgroup of perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) adsorbed to cavitating bubble-water interfaces during sonolysis was the rate-determining step in transformation to their inorganic constituents carbon monoxide, carbon dioxide, and fluoride; 2) ozone oxidation of aqueous iodide to hypoiodous acid at the aerosol-gas interface is the rate-determining step in the oxidation of bromide and chloride to dihalogens; 3) Electrolytic oxidation of anodic titanol surface groups is rate-limiting for the overall oxidation of organics by the dichloride radical. We also found chemistry unique to the interface, for example: 1) Adsorption of dilute PFOS(aq) and PFOA(aq) to acoustically cavitating bubble interfaces was greater than equilibrium expectations due to high-velocity bubble radial oscillations; 2) Relative ozone oxidation kinetics of aqueous iodide, sulfite, and thiosulfate were at variance with previously reported bulk aqueous kinetics; 3) Organics that directly chelated with the anode surface were oxidized by direct electron transfer, resulting in immediate carbon dioxide production but slower overall oxidation kinetics. Chemical reactions at aqueous interfaces can be the rate-limiting step of a reaction network and often display novel mechanisms and kinetics as compared to homogeneous chemistry.

Vecitis, Chad David

243

Mild Traumatic Brain Injury in Translation  

PubMed Central

Abstract This Introduction to a Special Issue on Mild Traumatic Brain Injury (mTBI) highlights the methodological challenges in outcome studies and clinical trials involving patients who sustain mTBI. Recent advances in brain imaging and portable, computerized cognitive tasks have contributed to protocols that are sensitive to the effects of mTBI and efficient in time for completion. Investigation of civilian mTBI has been extended to single and repeated injuries in athletes and blast-related mTBI in service members and veterans. Despite differences in mechanism of injury, there is evidence for similar effects of acceleration-deceleration and blast mechanisms of mTBI on cognition. Investigation of repetitive mTBI suggests that the effects may be cumulative and that repeated mTBI and repeated subconcussive head trauma may lead to neurodegenerative conditions. Although animal models of mTBI using cortical impact and fluid percussion injury in rodents have been able to reproduce some of the cognitive deficits frequently exhibited by patients after mTBI, modeling post-concussion symptoms is difficult. Recent use of closed head and blast injury animal models may more closely approximate clinical mTBI. Translation of interventions that are developed in animal models to patients with mTBI is a priority for the research agenda. This Special Issue on mTBI integrates basic neuroscience studies using animal models with studies of human mTBI, including the cognitive sequelae, persisting symptoms, brain imaging, and host factors that facilitate recovery.

Robertson, Claudia S.

2013-01-01

244

A comparison of emotional decoding abilities in patients with amnestic mild cognitive impairment, very mild and mild Alzheimer's disease.  

PubMed

Deficits in emotional decoding abilities were described in patients with Alzheimer's dementia and amnestic type of mild cognitive impairment (a-MCI). However the pattern of decline and its dependency on the type of emotional stimuli has not been investigated so far. In our study, 5 sets of cartoon-like drawings portraying various human emotions of increasing complexity were presented to patients with very mild and mild Alzheimer's dementia, a-MCI and control subjects. Patients with Alzheimer's dementia, a-MCI and control subjects decoded emotions with similar accuracy. The pattern of decoding abilities was similar in Alzheimer's dementia, a-MCI patients and healthy control subjects. Decoding abilities depended on a manner the emotional stimuli were presented. PMID:24359502

Klimkowicz-Mrowiec, Aleksandra; Krzywoszanski, Lukasz; Spisak, Karolina; Donohue, Bryan E; Szczudlik, Andrzej; Slowik, Agnieszka

2014-02-01

245

[A case report of mild from of phenylketonuria].  

PubMed

We report a 19-year-old man with mild form of phenylketonuria. The diagnosis was first made when he was examined for the tremor at 19 years of age. He had not received the Guthrie's screening test for phenylketonuria in infancy. His development of speech and walking was almost normal. Action and positional tremor developed at two years of age, and psychomotor deterioration at five years. His intelligence was of borderline, and he entered the special class for the mentally retarded at elementary school and junior high school. His skin and iris were less pigmented than those of Japanese young adults, and his hair was rather reddish. He had mild action tremor. He showed mild mental retardation, and the WAIS was 46 in PIQ, 70 in VIQ and 53 in total IQ. T2-weighted MRI of the brain showed high signal of the deep white matter around the posterior conus of the lateral ventricles. EEG showed paroxysmal abnormalities. Serum aminogram disclosed a marked elevation of phenylalanine. Analyses of pteridine in the serum and urine disclosed a low ratio of neopterine/biopterine. An assay of the dehydropteridine reductase in erythrocytes was normal. These laboratory data indicated that his condition was caused by a deficiency of phenylalanine hydroxylase deficiency. PMID:8905994

Komada, S; Masuzugawa, S; Taniguchi, A; Narita, Y; Kuzuhara, S

1996-05-01

246

Aqueous Inorganic Sonochemistry  

NASA Astrophysics Data System (ADS)

This chapter discusses the effect of ultrasound propagation in water and aqueous solutions, in the atmosphere of inert and reactive gases. Sonochemical studies of aqueous solutions of divalent and trivalent metal ions and their salts have been reviewed and the precipitation behaviour of hydroxides of metal ions has been discussed. Synthesis of nanoparticles of many metals using ultrasound and in aqueous solutions has also been discussed briefly. Besides, the nephelometric and conductometric studies of sonicated solutions of these metal ions have been reported.

Pankaj

247

[Characteristics of mild hypertension in elderly patients].  

PubMed

Prevalence of mild hypertension is approximately 40% in 70 years or older. Stratification of risk for evaluation of the prognosis indicates that the risk for cerebrovascular and cardiovascular diseases increases with accumulation of risk factors even in moderate hypertensive patients. Elderly patients already have one of risk factor, that is, age. Therefore, complication of more than one of risk factors such as smoking, diabetes mellitus, dyslipidemia, obesity, microalbuminuria, and family history of premature cardiovascular diseases indicates that cardiovascular risk is moderate or high risk even though their category of blood pressure is mild level. Although number of current smoker and obesity decreases in elderly subjects, prevalence of these risks is still 30%. Prevalence of obesity and diabetes mellitus is similar between mild hypertension and moderate hypertension. HYVET (hypertension in the very elderly) indicates that moderate and severe hypertension should be aggressively treated even those patients are 80 years or older, but evidence of antihypertensive treatment has not been clarified. PMID:18700547

Rakugi, Hiromi

2008-08-01

248

A simple aqueous metathesis reaction yields new lanthanide monothiophosphates  

SciTech Connect

This paper describes the synthesis and characterization of two, new rare earth monothiophosphate materials, LaPO{sub 3}S.xH{sub 2}O and NdPO{sub 3}S.yH{sub 2}O, and their properties in comparison to the corresponding orthophosphates prepared by a similar aqueous metathesis reaction. Each of these new materials was found to exist in an amorphous phase similar to a corresponding orthophosphate mineral. The new rhabdophane-type oxythiophosphates were found to display reversible dehydration and rehydration under mild conditions. The materials were found to be thermally unstable. Disproportionation was found to occur at less than 450 deg. C under vacuum. Sulfur is lost during heating in air between 450 and 650 deg. C, according to thermogravimetric analysis (TGA) experiments, yielding the orthophosphate. The monothiophosphate hydrates display broad photoluminescence in the visible under excitation by a 325 nm laser. The compounds were also analyzed using differential thermal analysis, FT-IR and UV/vis/NIR spectroscopy. - Graphical abstract: This paper describes the synthesis and characterization of two, new rare earth monothiophosphate materials, LaPO{sub 3}S.xH{sub 2}O and NdPO{sub 3}S.yH{sub 2}O. Each of these was found to exist in a phase similar to the orthophosphate mineral, rhabdophane. The monothiophosphate hydrates displayed broad photoluminescence in the visible under excitation by a 325 nm laser.

Takas, Nathan J.; Slomka, Lauren E. [Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282 (United States); Yang Xiaocheng; Giles, Nancy [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States); Aitken, Jennifer A. [Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282 (United States)], E-mail: Aitkenj@duq.edu

2008-11-15

249

Counseling in isolated mild fetal ventriculomegaly.  

PubMed

In this Review we aim to provide up-to-date and evidence-based answers to the common questions regarding the diagnosis of isolated mild fetal ventriculomegaly (VM). A literature search was performed to identify all reports of antenatal VM in the English language literature. In addition, reference lists of articles identified using the search were scrutinized to further identify relevant articles. Fetal mild VM is commonly defined as a ventricular atrial width of 10.0-15.0 mm, and it is considered isolated if there are no associated ultrasound abnormalities. There is no good evidence to suggest that the width of the ventricular atria contributes to the risk of neurodevelopmental outcome in fetuses with mild VM. The most important prognostic factors are the association with other abnormalities that escape early detection and the progression of ventricular dilatation, which are reported to occur in about 13% and 16% of cases, respectively. Most infants with a prenatal diagnosis of isolated mild VM have normal neurological development at least in infancy. The rate of abnormal or delayed neurodevelopment in infancy is about 11%, and it is unclear whether this is higher than in the general population. Furthermore, the number of infants that develop a real handicap is unknown. There are limitations of existing studies of mild VM. Although they address many of the relevant questions regarding the prognosis and management of fetal isolated mild VM, there is a lack of good-quality postnatal follow-up studies. The resulting uncertainties make antenatal counseling for this abnormality difficult. PMID:19644944

Melchiorre, K; Bhide, A; Gika, A D; Pilu, G; Papageorghiou, A T

2009-08-01

250

Prognosis for mild traumatic brain injury: results of the who collaborating centre task force on mild traumatic brain injury  

Microsoft Academic Search

We searched the literature on the epidemiology, diagnosis, prognosis, treatment and costs of mild traumatic brain injury. Of 428 studies related to prognosis after mild traumatic brain injury, 120 (28%) were accepted after critical review. These comprise our best-evidence synthesis on prognosis after mild traumatic brain injury. There was consistent and methodologically sound evidence that chil- dren's prognosis after mild

Linda J Carroll; J. David Cassidy; Paul M. Peloso; Jörgen Borg; Hans von Holst; Lena Holm; Chris Paniak; Michel Pépin

2004-01-01

251

Ions in Aqueous Solution  

NSDL National Science Digital Library

This 11-page PDF document is part of an environmental geochemistry course taught by Dr. David Sherman at the University of Bristol. Topics include the aqueous behavior of ions based on their size and charge, the meaning of activity of ions in aqueous solution, the equilibrium constant, complexation of ions and hydrolysis of cations. Also included are informative illustrations, diagrams and equations.

Sherman, David M.; Bristol, University O.

252

Effective Reading Instruction for Mildly Handicapped Adolescents.  

ERIC Educational Resources Information Center

A psycholinguistic approach to reading instruction for mildly handicapped adolescents, emphasizing meaning rather than discrete reading skills, may include such assessment techniques as modified miscue analysis and informal reading inventories and such instructional alternatives as guided reading, previewing, and study strategies. (CL)

Saski, Jim, Carter, Jade

1984-01-01

253

Mild Cognitive Impairment: Clinical Characterization and Outcome  

Microsoft Academic Search

Results: The primary distinction between control sub- jects and subjects with MCI was in the area of memory, while other cognitive functions were comparable. How- ever, when the subjects with MCI were compared with the patients with very mild AD, memory performance was similar, but patients with AD were more impaired in other cognitive domains as well. Longitudinal performance dem-

Ronald C. Petersen; Glenn E. Smith; Stephen C. Waring; Robert J. Ivnik; Eric G. Tangalos; Emre Kokmen

1999-01-01

254

Neurofeedback Therapy for a Mild Head Injury  

Microsoft Academic Search

The purpose of this study was to evaluate Neurofeedback Therapy (NFT) for a Mild Head Injury (MHI). The subject was a 58-year-old female who fell and struck her head in 1988. The NFT began in 1994 and was preceded and followed by neuropsychiatric and neuropsychological evaluations as well as quantified electroencephalograms (QEEG). The patient completed a symptom checklist and the

Alvah P. Byers

1995-01-01

255

Mild gasification mechanism and char conversion  

SciTech Connect

The purpose of this program is to obtain process chemistry data for (1) the mild gasification of several ranks of coal in a stirred moving bed reactor as function of process variables and (2) the hydrogasification of char from the mild gasification of Wyodak coal in a countercurrent moving bed reactor. Mild gasification experimental runs are being preformed in a long stirred moving-bed reactor constructed of a high alloy stainless steel. The feed to the moving bed reactor is through an entrained flow tube long reactor which preheats the coal particles with cocurrent sweep gas up to 400{degree}C, at which temperature there is essentially no formation of condensible coproducts. The yields of coproducts are than obtained as a function of several parameters. In the second part of the program, a moving bed countercurrent flow reactor. The reactor is designed for a gas flow rate below the incipient fluidization velocity of the column char. Char from the mild gasification of Wyodak sub-bituminous coal will be initially used in this investigation. 1 ref., 11 figs., 3 tabs.

Fallon, P.; Sundaram, M.S.; Steinberg, M.

1990-01-01

256

Chlorthalidone in mild hypertension — Dose response relationship  

Microsoft Academic Search

The dose response curve for 25, 50, 75 and 100 mg doses of chlorthalidone was studied in double blind fashion over an 8 week period in patients who presented with untreated mild hypertension. One hundred and thirty four patients completed this multicentre, family practice study. After 2 week's medication, a decline in blood pressure was noted in all dosage groups

J. G. Russell; S. R. Mayhew; I. S. Humphries

1981-01-01

257

Perinatal Risk Factors for Mild Motor Disability  

ERIC Educational Resources Information Center

The aetiology of mild motor disability (MMD) is a complex issue and as yet is poorly understood. The aim of this study was to identify the prevalence of perinatal risk factors in a cohort of 10-year-old boys and girls with (n = 362) and without (n = 1193) MMD. Among the males with MMD there was a higher prevalence of postpartum haemorrhage,…

Hands, Beth; Kendall, Garth; Larkin, Dawne; Parker, Helen

2009-01-01

258

Caffeine restriction: effect on mild hypertension  

Microsoft Academic Search

OBJECTIVE--To determine the effects on blood pressure of modifying dietary caffeine intake in patients with mild and borderline hypertension by monitoring ambulatory and clinic blood pressure. DESIGN--Four way, randomised, crossover trial of four consecutive two week dietary regimens: normal diet, caffeine free diet alone, caffeine free diet with decaffeinated instant coffee, caffeine free diet with caffeinated instant coffee (instant coffee

T M MacDonald; K Sharpe; G Fowler; D Lyons; S Freestone; H G Lovell; J Webster; J C Petrie

1991-01-01

259

Laboratory studies of the aqueous-phase oxidation of polyols: submicron particles vs. bulk aqueous solution  

NASA Astrophysics Data System (ADS)

Oxidation in the atmospheric aqueous phase (cloud droplets and deliquesced particles) has received recent attention as a potential pathway for the formation of highly oxidized organic aerosol. Most laboratory studies of aqueous-phase oxidation, however, are carried out in bulk solutions rather than aqueous droplets. Here we describe experiments in which aqueous oxidation of polyols (water-soluble species with chemical formula CnH2n+2On) is carried out within submicron particles in an environmental chamber, allowing for significant gas-particle partitioning of reactants, intermediates, and products. Dark Fenton chemistry is used as a source of hydroxyl radicals, and oxidation is monitored using a high-resolution aerosol mass spectrometer (AMS). Aqueous oxidation is rapid, and results in the formation of particulate oxalate; this is accompanied by substantial loss of carbon to the gas phase, indicating the formation of volatile products. Results are compared to those from analogous oxidation reactions carried out in bulk solution. The bulk-phase chemistry is similar to that in the particles, but with substantially less carbon loss. This is likely due to differences in partitioning of early-generation products, which evaporate out of the aqueous phase under chamber conditions (in which liquid water content is low), but remain in solution for further aqueous processing in the bulk phase. This work suggests that the product distributions from oxidation in aqueous aerosol may be substantially different from those in bulk oxidation experiments. This highlights the need for aqueous oxidation studies to be carried out under atmospherically relevant partitioning conditions, with liquid water contents mimicking those of cloud droplets or aqueous aerosol.

Daumit, K. E.; Carrasquillo, A. J.; Hunter, J. F.; Kroll, J. H.

2014-05-01

260

Bioethanol production from barley hull using SAA (soaking in aqueous ammonia) pretreatment  

Microsoft Academic Search

Barley hull, a lignocellulosic biomass, was pretreated using aqueous ammonia, to be converted into ethanol. Barley hull was soaked in 15 and 30 wt.% aqueous ammonia at 30, 60, and 75°C for between 12h and 11 weeks. This pretreatment method has been known as “soaking in aqueous ammonia” (SAA). Among the tested conditions, the best pretreatment conditions observed were 75°C,

Tae Hyun Kim; Frank Taylor; Kevin B. Hicks

2008-01-01

261

Corrosion of Bare and Galvanized Mild Steel in Arabian Gulf Environment  

NASA Astrophysics Data System (ADS)

Corrosion performance of bare and galvanized mild steel in atmospheric, soil and splash zone exposure conditions was evaluated at a Khaleej Mardumah test station (KMTS) in Jubail Industrial City (JIC) located at Arabian Gulf coast. The samples were exposed for a period of 15 months. During the exposure, the environmental conditions were periodically monitored by analysis of air, soil, groundwater, and seawater samples. The corroded mild steel and galvanized steel samples were examined by SEM, XRD and XRF to identify the corrosion products and study their surface morphology. Weight loss method was employed to determine the corrosion rates. The experimental results showed that intense temperature and humidity variations as well as high chloride and sulfate concentrations in the region result in severe corrosion of bare mild steel especially under the splash zone conditions. A comparison with the corrosion data for other parts of the world shows that atmospheric and soil environments at the selected test site are significantly corrosive to mild steel. The splash zone, on the other hand, is much more corrosive to mild and galvanized steel than the other parts of the world.

Saricimen, H.; Ahmad, A.; Quddus, A.; Aksakal, A.; Ul-Hamid, A.; Siddique, T. A.

2010-10-01

262

Altered Oscillation and Synchronization of Default-Mode Network Activity in Mild Alzheimer's Disease Compared to Mild Cognitive Impairment: An Electrophysiological Study  

PubMed Central

Some researchers have suggested that the default mode network (DMN) plays an important role in the pathological mechanisms of Alzheimer’s disease (AD). To examine whether the cortical activities in DMN regions show significant difference between mild AD from mild cognitive impairment (MCI), electrophysiological responses were analyzed from 21 mild Alzheimer’s disease (AD) and 21 mild cognitive impairment (MCI) patients during an eyes closed, resting-state condition. The spectral power and functional connectivity of the DMN were estimated using a minimum norm estimate (MNE) combined with fast Fourier transform and imaginary coherence analysis. Our results indicated that source-based EEG maps of resting-state activity showed alterations of cortical spectral power in mild AD when compared to MCI. These alterations are characteristic of attenuated alpha or beta activities in the DMN, as are enhanced delta or theta activities in the medial temporal, inferior parietal, posterior cingulate cortex and precuneus. With regard to altered synchronization in AD, altered functional interconnections were observed as specific connectivity patterns of connection hubs in the precuneus, posterior cingulate cortex, anterior cingulate cortex and medial temporal regions. Moreover, posterior theta and alpha power and altered connectivity in the medial temporal lobe correlated significantly with scores obtained on the Mini-Mental State Examination (MMSE). In conclusion, EEG is a useful tool for investigating the DMN in the brain and differentiating early stage AD and MCI patients. This is a promising finding; however, further large-scale studies are needed.

Yan, Sui-Hing; Chen, Wei-Ta; Lin, Yung-Yang

2013-01-01

263

Fixed points and exponential stability of mild solutions of stochastic partial differential equations with delays  

NASA Astrophysics Data System (ADS)

The fixed-point theory is first used to consider the stability for stochastic partial differential equations with delays. Some conditions for the exponential stability in pth mean as well as in sample path of mild solutions are given. These conditions do not require the monotone decreasing behavior of the delays, which is necessary in [T. Caraballo, K. Liu, Exponential stability of mild solutions of stochastic partial differential equations with delays, Stoch. Anal. Appl. 17 (1999) 743-763; Ruhollan Jahanipur, Stability of stochastic delay evolution equations with monotone nonlinearity, Stoch. Anal. Appl. 21 (2003) 161-181]. Even in this special case, our results also improve the results in [T. Caraballo, K. Liu, Exponential stability of mild solutions of stochastic partial differential equations with delays, Stoch. Anal. Appl. 17 (1999) 743-763].

Luo, Jiaowan

2008-06-01

264

Structural study of very thin anodic alumina films on silicon by anodization in citric acid aqueous solution.  

PubMed

The formation of thin alumina films on a silicon substrate by anodization in a mild acid, specifically in 1% wt citric acid aqueous solution, is investigated by transmission electron microscopy (TEM). We present a comparative study between two cases of starting material: pure aluminum and an alloy of aluminum with 1% silicon. In both cases the thickness of the Al layer was less than 50 nm. It was observed that under exactly the same conditions, in the first case the anodization was stopping before anodizing the whole film and a remaining non-anodized Al layer was always present, while in the second case, the Al layer was fully anodized, resulting in an alumina matrix with a very high density of silicon nanocrystals of uniform sizes embedded in it. In both cases the alumina film was compact and amorphous. PMID:15913255

Kokonou, M; Nassiopoulou, A G; Giannakopoulos, K P; Boukos, N; Travlos, A

2005-03-01

265

Absorption from Aqueous Solution.  

National Technical Information Service (NTIS)

A model based on material balance concepts and second-order reaction kinetics is presented for prediction of the performance of expanded-bed adsorption systems for treatment of complex mixtures of dissolved organic materials in aqueous solution. The model...

W. J. Weber P. J. Usinowics

1974-01-01

266

Reflectance of Aqueous Solutions.  

National Technical Information Service (NTIS)

The optical properties and optical constants of water and aqueous solutions were studied to develop an accurate tabulation of graphical representations of the optical constants through a broad spectrum. Manuscripts of articles are presented concerning ext...

M. R. Querry

1972-01-01

267

The ENCOAL Mild Gasification Demonstration Project  

SciTech Connect

The DOE plans to enter into a Cooperative Agreement with ENCOAL Corporation, a wholly owned subsidiary of Shell Mining Company, for the cost-shared design, construction and operation of a mild gasification facility based on Liquids-from-Coal (LFC) technology. The facility is planned to be located at the Triton Coal Company's Buckskin Mine near Gillette, Wyoming. The mild gasification process to be demonstrated will produce two new, low-sulfur fuel forms (a solid and a liquid) from subbituminous coal. The new fuel forms would be suitable for combustion in commercial, industrial, and utility boilers. This environmental assessment has been prepared by the DOE to comply with the requirements of the NEPA. Pollutant emissions, land use, water, and waste management are briefly discussed. 3 figs., 5 tabs.

Not Available

1990-07-01

268

Reflectance of aqueous solutions  

NASA Technical Reports Server (NTRS)

The optical properties and optical constants of water and aqueous solutions were studied to develop an accurate tabulation of graphical representations of the optical constants through a broad spectrum. Manuscripts of articles are presented concerning extinction coefficients, relative specular reflectance, and temperature effect on the water spectrum. Graphs of absolute reflectance, phase shifts, index of refraction, and extinction coefficients for water, heavy water and aqueous solutions are included.

Querry, M. R.

1972-01-01

269

Bound states in mildly curved layers  

Microsoft Academic Search

It has been shown recently that a nonrelativistic quantum particle constrained to a hard-wall layer of constant width built over a geodesically complete simply connected noncompact curved surface can have bound states, provided the surface is not a plane. In this paper we study the weak-coupling asymptotics of these bound states, i.e., the situation when the surface is a mildly

Pavel Exner; D. Krejcirík

2001-01-01

270

General and mild preparation of 2-aminopyridines.  

PubMed

A general and facile one-pot amination procedure for the synthesis of 2-aminopyridines from the corresponding pyridine-N-oxides is presented as a mild alternative to S(N)Ar chemistry. A variety of amines and heterocyclic-N-oxides participate effectively in this transformation which uses the phosphonium salt, PyBroP, as a means of substrate activation. PMID:20958085

Londregan, Allyn T; Jennings, Sandra; Wei, Liuqing

2010-11-19

271

A Modified Controlled Cortical Impact Technique to Model Mild Traumatic Brain Injury Mechanics in Mice  

PubMed Central

For the past 25?years, controlled cortical impact (CCI) has been a useful tool in traumatic brain injury (TBI) research, creating injury patterns that includes primary contusion, neuronal loss, and traumatic axonal damage. However, when CCI was first developed, very little was known on the underlying biomechanics of mild TBI. This paper uses information generated from recent computational models of mild TBI in humans to alter CCI and better reflect the biomechanical conditions of mild TBI. Using a finite element model of CCI in the mouse, we adjusted three primary features of CCI: the speed of the impact to achieve strain rates within the range associated with mild TBI, the shape, and material of the impounder to minimize strain concentrations in the brain, and the impact depth to control the peak deformation that occurred in the cortex and hippocampus. For these modified cortical impact conditions, we observed peak strains and strain rates throughout the brain were significantly reduced and consistent with estimated strains and strain rates observed in human mild TBI. We saw breakdown of the blood–brain barrier but no primary hemorrhage. Moreover, neuronal degeneration, axonal injury, and both astrocytic and microglia reactivity were observed up to 8?days after injury. Significant deficits in rotarod performance appeared early after injury, but we observed no impairment in spatial object recognition or contextual fear conditioning response 5 and 8?days after injury, respectively. Together, these data show that simulating the biomechanical conditions of mild TBI with a modified cortical impact technique produces regions of cellular reactivity and neuronal loss that coincide with only a transient behavioral impairment.

Chen, YungChia; Mao, Haojie; Yang, King H.; Abel, Ted; Meaney, David F.

2014-01-01

272

Decrement in Postural Control during Mild Hypobaric Hypoxia,  

National Technical Information Service (NTIS)

The majority of the studies on mild hypoxia in humans have concentrated on various performance indicators to determine if there are modifications to central nervous system (CNS) function. Other research on the physiological responses to mild hypoxia has i...

W. D. Frazer D. E. Eastman M. A. Paul J. A. Porlier

1987-01-01

273

Anthocyanins protect human endothelial cells from mild hyperoxia damage through modulation of Nrf2 pathway.  

PubMed

The detrimental effects of high oxygen supplementation have been widely reported. Conversely, few is known about the effects of exposure to mild hyperoxic conditions, an interesting issue since the use of oxygen-enriched mixture is now increasingly used in clinical practice and especially for professional and recreational reasons. Our study investigated if in vitro exposure of human umbilical vein endothelial cells (HUVECs) to moderate hyperoxia (O2 32 %) induces cellular alterations, measured as changes in cell signaling pathways. Furthermore, by means of an ex vivo experimental model where human volunteers were used as bioreactors, we studied whether anthocyanin metabolites are able to protect HUVECs against mild hyperoxia-induced damage. We observed that the cytotoxic effect of mild hyperoxia came along with a significant decrease in nuclear accumulation of the transcription factor Nrf2, as well as in the expression of Nrf2-regulated antioxidant and cytoprotective genes. Furthermore, under normoxic conditions, anthocyanin metabolites appeared able to activate the Nrf2 pathway, through the involvement of specific kinases (ERK1/2); this adaptive effect may explain the protective effect observed in mild hyperoxia-exposed HUVECs following anthocyanin pretreatment. This study confirms that dietary anthocyanins and/or their metabolites can protect endothelial cells against mild hyperoxia-induced alterations acting as cell signaling modulators. PMID:23229494

Cimino, Francesco; Speciale, Antonio; Anwar, Sirajudheen; Canali, Raffaella; Ricciardi, Elisabetta; Virgili, Fabio; Trombetta, Domenico; Saija, Antonina

2013-07-01

274

The aqueous geochemistry of gallium, germanium, indium and scandium  

Microsoft Academic Search

Relatively little information is available in the literature regarding the speciation and solubility of Ga, Ge, In and Sc in aqueous solutions, especially at elevated temperatures and pressures. In this paper we critically review stability constants for relevant aqueous complexes of these metals and solubility products for relevant solid phases. Most of the available data refer to standard conditions of

Scott A. Wood; Iain M. Samson

2006-01-01

275

Mechanism of chitosan adsorption on silica from aqueous solutions.  

PubMed

We present a study of the adsorption of chitosan on silica. The adsorption behavior and the resulting layer properties are investigated by combining optical reflectometry and the quartz crystal microbalance. Exactly the same surfaces are used to measure the amount of adsorbed chitosan with both techniques, allowing the systematic combination of the respective experimental results. This experimental protocol makes it possible to accurately determine the thickness of the layers and their water content for chitosan adsorbed on silica from aqueous solutions of varying composition. In particular, we study the effect of pH in 10 mM NaCl, and we focus on the influence of electrolyte type and concentration for two representative pH conditions. Adsorbed layers are stable, and their properties are directly dependent on the behavior of chitosan in solution. In mildly acidic solutions, chitosan behaves like a weakly charged polyelectrolyte, whereby electrostatic attraction is the main driving force for adsorption. Under these conditions, chitosan forms rigid and thin adsorption monolayers with an average thickness of approximately 0.5 nm and a water content of roughly 60%. In neutral solutions, on the other hand, chitosan forms large aggregates, and thus adsorption layers are significantly thicker (?10 nm) as well as dissipative, resulting in a large maximum of adsorbed mass around the pK of chitosan. These films are also characterized by a substantial amount of water, up to 95% of their total mass. Our results imply the possibility to produce adsorption layers with tailored properties simply by adjusting the solution chemistry during adsorption. PMID:24725003

Tiraferri, Alberto; Maroni, Plinio; Caro Rodríguez, Diana; Borkovec, Michal

2014-05-01

276

Alexander disease with mild dorsal brainstem atrophy and infantile spasms.  

PubMed

We present the case of a Japanese male infant with Alexander disease who developed infantile spasms at 8 months of age. The patient had a cluster of partial seizures at 4 months of age. He presented with mild general hypotonia and developmental delay. Macrocephaly was not observed. Brain magnetic resonance imaging (MRI) findings fulfilled all MRI-based criteria for the diagnosis of Alexander disease and revealed mild atrophy of the dorsal pons and medulla oblongata with abnormal intensities. DNA analysis disclosed a novel heterozygous missense mutation (c.1154 C>T, p.S385F) in the glial fibrillary acidic protein gene. At 8 months of age, tonic spasms occurred, and electroencephalography (EEG) revealed hypsarrhythmia. Lamotrigine effectively controlled the infantile spasms and improved the abnormal EEG findings. Although most patients with infantile Alexander disease have epilepsy, infantile spasms are rare. This comorbid condition may be associated with the distribution of the brain lesions and the age at onset of Alexander disease. PMID:22818990

Torisu, Hiroyuki; Yoshikawa, Yoko; Yamaguchi-Takada, Yui; Yano, Tamami; Sanefuji, Masafumi; Ishizaki, Yoshito; Sawaishi, Yukio; Hara, Toshiro

2013-05-01

277

Amberlyst-15: a mild, efficient and reusable heterogeneous catalyst for N- tert-butoxycarbonylation of amines  

Microsoft Academic Search

A mild and versatile method has been developed for the chemoselective N-tert-butoxycarbonylation of amines in the presence of Amberlyst-15 under solvent-free condition. The method is general for the preparation of N-Boc derivatives of aliphatic (acyclic and cyclic) and aromatic amines.

K. Shiva Kumar; Javed Iqbal; Manojit Pal

2009-01-01

278

Patterns of Word-List Generation in Mild Cognitive Impairment and Alzheimer's Disease  

Microsoft Academic Search

Patients with amnestic mild cognitive impairment (aMCI) have been described as exhibiting greater impairment on tests of category fluency than letter fluency. This has been offered as evidence that this condition represents pre-clinical Alzheimer's disease (AD). We hypothesized that this pattern of differential impairment is dependent on the specific semantic categories and initial letters selected, and is not specific to

Jason Brandt; Kevin J. Manning

2009-01-01

279

Combination of Hippocampal Volume and Cerebrospinal Fluid Biomarkers Improves Predictive Value in Mild Cognitive Impairment  

Microsoft Academic Search

Background: Mild cognitive impairment (MCI) is a heterogeneous condition, and the prognosis differs within the group. Recent findings suggest that hippocampal volumetry and CSF biomarkers can be used to predict which MCI patients have an underlying neurodegenerative disorder. Objective: To examine the combined predictive value of hippocampal volume and CSF levels of total tau (T-tau) and ?-amyloid42 (A?42) in stable

C. Eckerström; U. Andreasson; E. Olsson; S. Rolstad; K. Blennow; H. Zetterberg; H. Malmgren; Å. Edman; A. Wallin

2010-01-01

280

People with Mild to Moderate Intellectual Disability Talking about Their Diabetes and How They Manage  

ERIC Educational Resources Information Center

Background: The prevalence of diabetes is relatively high in people with intellectual disability (ID). However, little is known about how people with ID experience having diabetes and how they manage the condition. Method: Seventeen people with mild to moderate ID who have diabetes were interviewed. A framework on illness perceptions having an…

Cardol, M.; Rijken, M.; van Schrojenstein Lantman-de Valk, H.

2012-01-01

281

A direct and mild formylation method for substituted benzenes utilizing dichloromethyl methyl ether-silver trifluoromethanesulfonate.  

PubMed

A silver trifluoromethanesulfonate (AgOTf)-promoted direct and mild formylation of benzenes has been developed. The reaction utilizing dichloromethyl methyl ether (Cl2CHOMe) and AgOTf powerfully formylated various substituted benzenes under temperature conditions as low as -78 °C without losing the protecting groups on the phenolic hydroxyl group. PMID:23477294

Ohsawa, Kosuke; Yoshida, Masahito; Doi, Takayuki

2013-04-01

282

A novel method for the mild and selective amidation of diesters and the amidation of monoesters  

Microsoft Academic Search

The selective monoamidation of diesters and amidation of esters mediated by Lewis acids are described. The selective amidations of dimethyl pyridine-2,5-dicarboxylate (1) and dimethyl 2,3-indole-dicarboxylate (4) with primary and secondary amines mediated by MgCl2 or MgBr2 under mild conditions gave the corresponding ester-amides in high yield.

Zhenrong Guo; Eric D Dowdy; Wen-Sen Li; Richard Polniaszek; Edward Delaney

2001-01-01

283

Understanding failure of visual paired associate learning in amnestic mild cognitive impairment  

Microsoft Academic Search

Impairment in visual paired associate learning occurs often in with amnestic mild cognitive impairment (aMCI), a condition considered to be an early stage of Alzheimer's disease (AD). To date, studies of aMCI have characterized impaired visual paired associate learning only in terms of summary scores such as total errors or total trials to criterion. The aim of this study was

Jade ODonnell; Robert H. Pietrzak; Kathryn C. Ellis; Peter J. Snyder; Paul Maruff

2011-01-01

284

Developing Reading Comprehension among Students with Mild Intellectual Disabilities: An Intervention Study  

ERIC Educational Resources Information Center

The present study demonstrated that students with mild intellectual disabilities are capable of constructing meaning from written text by guided social interaction. Participants were 40 adolescents in special schools divided into two intervention conditions: reciprocal teaching (RT) and inference teaching (IT). In RT the students practiced four…

Lundberg, Ingvar; Reichenberg, Monica

2013-01-01

285

Organoselenium-catalyzed mild dehydration of aldoximes: an unexpected practical method for organonitrile synthesis.  

PubMed

Areneselenenic acids (ArSeOH), readily generated from diaryl diselenides and H2O2 by in situ oxidation, were found to be effective and reusable catalysts for dehydration of aldoximes, leading to a practical and scalable preparation of useful organonitriles under mild conditions. PMID:24564392

Yu, Lei; Li, Hongyan; Zhang, Xu; Ye, Jianqing; Liu, Jianping; Xu, Qing; Lautens, Mark

2014-03-01

286

The extent of aqueous alteration in C-class asteroids, and the survival of presolar isotopic signatures in chondrites  

NASA Astrophysics Data System (ADS)

Several sample return missions are being planned by different space agencies for in situ sampling of undifferentiated bodies. Such missions wish to bring back to Earth pristine samples from C-class asteroids and comets to obtain clues on solar system formation conditions. A careful selection of targeted areas is required as many C-class asteroids and periodic comets have been subjected to collisional and space weathering processing since their formation. Their surfaces have been reworked by impacts as pointed out by the brecciated nature of many chondrites arrived to Earth, exhibiting different levels of thermal and aqueous alteration. It is not surprising that pristine chondrites can be considered quite rare in meteorite collections because they were naturally sampled in collisions, but several groups of carbonaceous chondrites contain a few members with promising unaltered properties. The CI and CM groups suffered extensive aqueous alteration [1], but for the most part escaped thermal metamorphism (only a few CMs evidence heating temperature over several hundred K). Both chondrite groups are water-rich, containing secondary minerals as consequence of the pervasive alteration of their primary mineral phases [2]. CO, CV, and CR chondrite groups suffered much less severe aqueous alteration, but some CRs are moderately aqueously altered. All five groups are good candidates to find unequilibrated materials between samples unaffected by aqueous alteration or metamorphism. The water was incorporated during accretion, and was released as consequence of shock after impact compaction, and/or by mild radiogenic heating. Primary minerals were transformed by water into secondary ones. Water soaking the bodies participated in chemical homogenization of the different components [1]. Hydrothermal alteration and collisional metamorphism changed the abundances of isotopically distinguishable presolar silicates [3]. Additional instruments in the landers to identify aqueous alteration signatures could help to get samples unbiased by parent body processes. Future work in this regard could be essential to successfully getting back to Earth samples to unveil the conditions in which the solar system formed. REF: [1] Trigo-Rodriguez J.M. & Blum J. 2009. Plan. Space Sci.57,243; [2] Rubin et al. (2007) GCA 71,2361; [3] Trigo-Rodriguez J.M. & Blum J. (2009). Pub.Ast.Soc.Aust.26,289

Trigo-Rodriguez, J. M.

2011-05-01

287

Process for purifying an aqueous, hydrogen sulfide-scrubbing solution  

SciTech Connect

This patent describes a process for purifying an aqueous hydrogen sulfide-scrubbing solution containing a water-soluble vanadium component and a water-soluble organic compound, the scrubbing solution being capable of absorbing hydrogen sulfide and converting the hydrogen sulfide into elemental sulfur. The process comprises: forming a slurry by mixing the scrubbing solution with particles of a spent solid catalyst containing molybdenum and aluminum and a basic aqueous solution; contacting the slurry with an oxygen-containing gas under conditions such that the molybdenum in the catalyst is dissolved and oxidized to molybdate while the aluminum remains substantially in the form of a solid residue; separating the aqueous solution formed from the solid residue; contacting the aqueous solution with hydrogen sulfide under conditions such that the molybdenum in the solution is precipitated, thereby forming an aqueous solution having a reduced concentration of molybdenum; contacting the aqueous solution having a reduced concentration of molybdenum with a base under conditions such that the vanadium in the solution is precipitated, thereby forming an aqueous solution having a reduced concentration of vanadium and molybdenum; and recovering the aqueous solution having a reduced concentration of vanadium and molybdenum as wastewater.

Koepke, J.W.; Delaney, D.D.

1989-11-28

288

ENCOAL mild coal gasification project. Annual report  

SciTech Connect

This document is the combination of the fourth quarter report (July--September 1993) and the 1993 annual report for the ENCOAL project. The following pages include the background and process description for the project, brief summaries of the accomplishments for the first three quarters, and a detailed fourth quarter report. Its purpose is to convey the accomplishments and current progress of the project. ENCOAL Corporation, has completed the construction of a mild gasification demonstration plant at Triton Coal Company`s Buckskin Mine near Gillette, Wyoming. The process, using Liquids From Coal (LFC) technology developed by SMC and SGI International, utilizes low-sulfur Powder River Basin coal to produce two new fuels, Process Derived Fuel (PDF) and Coal Derived Liquids (CDL). ENCOAL submitted an application to the US Department of Energy (DOE) in August 1989, soliciting joint funding of the project in the third round of the Clean Coal Technology Program. The project was selected by DOE in December, 1989 and the Cooperative Agreement approved in September, 1990. Construction, commissioning, and start-up of the ENCOAL mild coal gasification facility was completed in June of 1992, and the project is currently in the operations phase. Some plant modifications have been required and are discussed in this report.

Not Available

1993-10-01

289

Luminescence of Tb3+ and Gd3+ ions in sonolysis under the conditions of a single bubble moving in aqueous solutions of TbCl3 and GdCl3  

NASA Astrophysics Data System (ADS)

Luminescence bands of Tb3+ and Gd3+ ions are detected during sonolysis in the regime of a moving single bubble in aqueous solutions of TbCl3 and GdCl3 salts with concentration 1-2 mol/L. Saturation with argon, low temperatures of solutions (-5°C), and a high concentration of salts are the factors facilitating sonoluminescence of the metal. Comparison with the characteristics of sonoluminescence of lanthanide ions studied earlier in the regimes of multibubble and single-bubble sonolysis with a stationary bubble shows that the electron excitation of metal ions in the given case is associated with translational displacements of the bubble. Our results confirm the validity of the sonochemical model of microdroplet injection, which explains the penetration of nonvolatile salts into cavitation bubbles as a result of their deformation during intense movements.

Sharipov, G. L.; Abdrakhmanov, A. M.; Gareev, B. M.

2013-02-01

290

Aqueous Electrolyte Batteries  

Microsoft Academic Search

Despite the growing interest in advanced lithium batteries, the overwhelming majority of batteries manufactured today are still based on aqueous electrolytes, mostly sulphuric acid or potassium hydroxide solution. The ubiquitous lead-acid battery is, after 150 years, still being improved as regards its design and materials of construction. Rechargeable batteries based on potassium hydroxide electrolyte have nickel oxide or silver oxide

R. M. dell

1996-01-01

291

Adsorption from Aqueous Solution.  

National Technical Information Service (NTIS)

A number of different aspects of the adsorption of perdurable pollutants by carbon from aqueous solution have been studied to provide information for evaluation of the fluid-solid technique for treating waters and wastes. For all studies, attempts have be...

W. J. Weber

1966-01-01

292

Continuous aqueous tritium monitor  

DOEpatents

An apparatus for a selective on-line determination of aqueous tritium concentration is disclosed. A moist air stream of the liquid solution being analyzed is passed through a permeation dryer where the tritium and moisture and selectively removed to a purge air stream. The purge air stream is then analyzed for tritium concentration, humidity, and temperature, which allows computation of liquid tritium concentration.

McManus, Gary J. (Idaho Falls, ID); Weesner, Forrest J. (Idaho Falls, ID)

1989-05-30

293

Aqueous carbonaceous slurries  

Microsoft Academic Search

Aqueous carbonaceous slurries having reduced viscosity, a stabilized network of coal in water and improved pumpability are obtained by having present a salt of naphthalenesulfonic acid formaldehyde condensate and at least one water soluble polymer selected from the group consisting of gum karaya, mixtures of gum karaya and polyacrylamide and polysaccaride modified with polyacrylate. For example, a mixture of 61.5%

M. J. Schick; K. A. Knitter

1983-01-01

294

Low temperature abiotic formation of mesopyrophaeophorbide a from pyrophaeophorbide a under conditions simulating anoxic natural environments  

NASA Astrophysics Data System (ADS)

Reduction of the C-3 vinyl group to an ethyl substituent is a key, yet poorly understood, event in the diagenetic pathway linking chlorophyll a to sedimentary alkyl porphyrins. Laboratory simulation experiments employing conditions that mimic those of natural anoxic environments (aqueous media, low temperature, presence of H 2S and limitation of oxygen) lead to partial conversion of the chlorophyll a derivative methyl pyrophaeophorbide a to mesopyrophaeophorbide a via reduction of the C-3 vinyl substituent mediated by H 2S. The mild conditions employed, and the apparent susceptibility of methyl pyrophaeophorbide a to reductive transformation, implies that reduction mediated by H 2S could be a widespread process occurring in anoxic depositional environments. Our findings have implications for the geological preservation of chlorins and other biological markers and provide clear evidence that reactions involving H 2S are important in the geochemical reduction of sedimenting organic matter and can occur at temperatures within the range for natural environments.

Pickering, Matthew D.; Keely, Brendan J.

2011-01-01

295

Effect of aqueous fraction of Rosa damascena on ileum contractile response of guinea pigs  

PubMed Central

Objective: The use of drugs with herbal origin is increasing for treatment of gastrointestinal (GI) disorders. Rosa damascena (R. damascena) is a well-known plant suggested to have beneficial effect on GI system. In this study, the effect of aqueous fraction of R. damascena on the contractions of isolated guinea pig ileum was investigated. Materials and Methods: Aqueous fraction of plant was obtained from ethanolic extract after ethyl acetate and n-butanol fractions were discarded. To evaluate effect of this fraction on ileum contraction, guinea pig ileum was removed and mounted on organ bath and its contraction was recorded. Effect of various concentrations (0.66, 0.83, and 1.3 mg/ml) of aqueous fraction on ileum contraction in comparison with Ach in presence and absence of atropine, a muscarinic antagonist of cholinergic, was evaluated. The response of ileum to 1 µg/ml of acetylcholine was considered as 100% response. Results: Our results showed that aqueous fractions of R. damascena dose-dependently increased basal guinea pigs ileum contractions (p<0.05 to p<0.001). Maximal contraction of fraction (1.3 mg/ml) induced 23.4 % of maximal Ach response. The contraction of ileum to aqueous fraction was significant decreased in presence 0.001 µg/ml of atropine. Conclusion: It is concluded that aqueous fraction of R. damascena has mild excitatory effect on ileum contraction and this fraction may be beneficial as a mild laxative agent.

Dolati, Karim; Rakhshandeh, Hassan; Shafei, Mohammad Naser

2013-01-01

296

Synthesis of TiO2 nanocoral structures in ever-changing aqueous reaction systems.  

PubMed

A far-from-equilibrium strategy is developed to synthesize coral-like nanostructures of TiO(2) on a variety of surfaces. TiO(2) nanocoral structures consist of anatase base film and rutile nanowire layers, and they are continuously formed on substrates immersed in aqueous TiOSO(4)-H(2)O(2). The sequential deposition of TiO(2) starts with hydrolysis and condensation reactions of titanium peroxocomplexes in the aqueous phase, resulting in deposition of amorphous film. The film serves as adhesive interface on which succeeding growth of rutile nanowires to occur. This initial deposition reaction is accompanied by shift in pH of the reaction media, which is favorable condition for the growth of rutile nanocrystals. During the growth of rutile nanocoral layers, the amorphous base films are transformed to anatase phase. These sequential deposition reactions occur at temperatures as low as 80 °C, and the mild synthetic condition allows the use of a wide range of substrates such as ITO (indium tin oxide), glass, and even organic polymer films. The thickness of nanocoral layer is controllable by repeating the growth reaction of rutile nanocorals. TiO(2) nanocorals show photocatalytic activity as demonstrated by site-specific reduction of Ag(I) ions, which proceeds preferentially on the rutile nanowire layer. The rutile nanowire layer also shows photocatalytic decomposition of acetaldehyde, which is promoted upon increase of the thickness of the nanowire layer. The use of temporally transforming reaction media allows the formation of biphasic TiO(2) nanocoral structures, and the concept of nonequilibrium synthetic approach would be widely applicable to developing structurally graded inorganic nanointerfaces. PMID:22214471

Soejima, Tetsuro; Jin, Ren-Hua; Terayama, Yuki; Takahara, Atsushi; Shiraishi, Takamasa; Ito, Seishiro; Kimizuka, Nobuo

2012-02-01

297

VOC destruction by water diluted hydrogen mild combustion.  

PubMed

This study represents a preliminary numerical evaluation of the effect of steam dilution and hydrogen addition on the oxidation of formaldehyde and benzene, chosen as representative of the volatile organic compounds (VOC), in mild condition by evaluating the autoignition time and the steady state attainment. These parameters are important in the design of thermal VOC destruction plants since they influence the abatement efficiency and, therefore, the plant dimension. It has come out that, in comparison with the system diluted in nitrogen, steam induces lower autoignition times and, on the other hand, longer times for the attainment of the steady state. In contrast, for very high water content the autoignition time slightly increases. In particular results have shown that is possible to identify an optimum value of steam content that allows for the attainment of the steady state condition by the lowest residence time. Hydrogen addition to systems diluted in nitrogen promotes the oxidation reactions and anticipates the steady state condition. In steam diluted systems hydrogen delays the autoignition of the mixtures even though anticipates the attainment of the complete destruction of the VOC. The rate of production analysis has showed that the H(2)/O(2) reactions, that promote the ignition and the destruction of VOC, are sensibly modified by the presence of water and hydrogen. PMID:17287008

Sabia, P; Romeo, F; de Joannon, M; Cavaliere, A

2007-06-01

298

Atmospheric corrosion of mild steel in Oman  

NASA Astrophysics Data System (ADS)

A systematic study has been made of the initial corrosion products which form on mild steel capons exposed near the coastal region of Oman and at some industrial areas. The phases and compositions of the products formed at different periods of exposure were examined by using Mössbauer spectroscopy (295 and 78 K) and X-ray diffraction (XRD) techniques. The results show that lepidocorcite and maghemite are early corrosion products and goethite starts to form after 2 months of metal exposure to the atmosphere. Akaganeite is an early corrosion product but it forms in marine environments only, which reflects the role of chlorine effect in the atmosphere. The 12 months coupons showed the presence of goethite, lepidocorcite and maghemite, but no akaganeite being seen in the products of one of the studied areas.

Gismelseed, Abbasher; Al-Harthi, S. H.; Elzain, M.; Al-Rawas, A. D.; Yousif, A.; Al-Saadi, S.; Al-Omari, I.; Widatallah, H.; Bouziane, K.

2006-01-01

299

Atmospheric corrosion of mild steel in Oman  

NASA Astrophysics Data System (ADS)

A systematic study has been made of the initial corrosion products which form on mild steel capons exposed near the coastal region of Oman and at some industrial areas. The phases and compositions of the products formed at different periods of exposure were examined by using Mossbauer spectroscopy (295 and 78 K) and X-ray diffraction (XRD) techniques. The results show that lepidocorcite and maghemite are early corrosion products and goethite starts to form after 2 months of metal exposure to the atmosphere. Akaganeite is an early corrosion product but it forms in marine environments only, which reflects the role of chlorine effect in the atmosphere. The 12 months coupons showed the presence of goethite, lepidocorcite and maghemite, but no akaganeite being seen in the products of one of the studied areas.

Gismelseed, Abbasher; Al-Harthi, S. H.; Elzain, M.; Al-Rawas, A. D.; Yousif, A.; Al-Saadi, S.; Al-Omari, I.; Widatallah, H.; Bouziane, K.

300

Mild coal pretreatment to improve liquefaction reactivity  

SciTech Connect

This report describes work completed during the fourth quarter of a three year project to study the effects of mild chemical pretreatment on coal dissolution reactivity during low severity liquefaction or coal/oil coprocessing. The overall objective of this research is to elucidate changes in the chemical and physical structure of coal by pretreating with methanol or other simple organic solvent and a trace amount of hydrochloric acid and measure the influence of these changes on coal dissolution reactivity. This work is part of a larger effort to develop a new coal liquefaction or coal/oil coprocessing scheme consisting of three main process steps: (1) mile pretreatment of the feed coal to enhance dissolution reactivity and dry the coal, (2) low severity thermal dissolution of the pretreated coal to obtain a very reactive coal-derived residual material amenable to upgrading, and (3) catalytic upgrading of the residual products to distillate liquids.

Miller, R.L.

1991-01-01

301

Proton MRS in Mild Cognitive Impairment  

PubMed Central

Mild cognitive impairment (MCI) is a clinical syndrome operationalized for early diagnosis and treatment of Alzheimer’s disease (AD). Many individuals with MCI are at the prodromal stage of AD or other dementia. Various quantitative MR techniques that measure the anatomic, biochemical, microstructural, functional, and blood-flow changes are being evaluated as possible surrogate measures for early diagnosis and disease progression in AD. The pathology underlying MCI heterogenous, dominated by AD, cerebrovascular disease, Lewy body disease, or a mixture of these pathologies in community-based autopsy cohorts. Proton MRS metabolite markers may help identify and track etiologies that typically underlie MCI in the elderly. The role of proton MRS will especially be critical for pathophysiological processes for which a reliable biomarker does not exist such as glial and microglial activation in neurodegenerative dementia.

Kantarci, Kejal

2012-01-01

302

Macrocephaly-cutis marmorata telangiectatica congenita: a report on the natural history of a mild case.  

PubMed

Macrocephaly-cutis marmorata telangiectatica congenita was first identified as a distinct syndrome in 1997. Since then there have been more than 10 further reports of the condition, several also comprising reviews of the earlier literature. Virtually all reported patients, however, are young children, and there is very little information about the natural evolution of the condition in adolescence and later life. This report describes a patient with features of macrocephaly-cutis marmorata telangiectatica congenita, though mildly affected, and her progression into teenage life. Her mild problems, many of which have largely resolved, demonstrate a possible more optimistic view of the condition than is currently held. The difficulties in making the diagnosis in an adult patient are also discussed. PMID:18978660

Canham, Natalie L E; Holder, Susan E

2008-10-01

303

Bench-scale development of mild gasification char desulfurization. Technical report, 1 March--31 May 1994  

SciTech Connect

The goal of this project is to scale up a process, developed under a previous ICCI grant, for desulfurization of mild gasification char by treatment with hydrogen-rich process-derived fuel gas at 650--760 C and 7--15 atm. The char can be converted into a low-sulfur metallurgical form coke. In the prior study, IBC-105 coal with 4.0 wt% sulfur was converted to chars with less than 1.0 wt% sulfur in a laboratory-scale batch reactor. The susceptibility of the char to desulfurization was correlated with physicochemical char properties and mild gasification conditions. Acid pretreatment of the coal prior to mild gasification was also shown to significantly enhance subsequent sulfur removal. In this study, IGT is conducting continuous bench-scale tests in a 1-lb/h fluidized-bed reactor to determine the preferred process conditions and obtain steady-state data necessary for process design and scale-up. The desulfurized chars are to be used to produce low-sulfur form coke, which will be evaluated for density, reactivity, and strength properties relevant to utilization in blast furnaces. This quarter, 2,500 g of mild gasification char was produced from untreated IBC-105 coal in the bench-scale reactor. Half of this char will be subjected to sulfuric acid treatment to enhance subsequent desulfurization. Char-producing runs were also initiated with acid-pretreated coal, which will produce about 1,250 g of char.

Knight, R.A. [Inst. of Gas Technology, Chicago, IL (United States)

1994-09-01

304

Functional Connectivity in Mild Traumatic Brain Injury  

PubMed Central

Objectives Research suggests that the majority of mild traumatic brain injury (mTBI) patients exhibit both cognitive and emotional dysfunction within the first weeks of injury, followed by symptom resolution 3–6 months post-injury. The neuronal correlates of said dysfunction are difficult to detect with standard clinical neuroimaging, complicating differential diagnosis and early identification of patients who may not recover. The current study examined whether resting state functional magnetic resonance imaging (FMRI) provides objective markers of injury and predicts cognitive, emotional and somatic complaints in mTBI patients semi-acutely (< 3 weeks post-injury) and in late recovery (3–5 month) phases. Methods Twenty seven semi-acute mTBI patients and 26 gender, age and education matched controls were studied. Fifteen out of 27 patients returned for a follow-up visit 3–5 months post-injury. The main dependent variables were spontaneous fluctuations (temporal correlation) in the default-mode (DMN) and fronto-parietal task-related (TRN) networks as measured by FMRI. Results Significant differences in self-reported cognitive, emotional and somatic complaints were observed (all p < .05), despite normal clinical (T1 and T2) imaging and neuropsychological testing results. Mild TBI patients demonstrated decreased functional connectivity within the DMN and hyper-connectivity between the DMN and lateral prefrontal cortex. Measures of functional connectivity exhibited high levels of sensitivity and specificity for patient classification and predicted cognitive complaints in the semi-acute injury stage. However, no changes in functional connectivity were observed across a four month recovery period. Conclusions Abnormal connectivity between the DMN and frontal cortex may provide objective biomarkers of mTBI and underlie cognitive impairment.

Mayer, Andrew R.; Mannell, Maggie V.; Ling, Josef; Gasparovic, Charles; Yeo, Ronald A.

2011-01-01

305

Mild Traumatic Brain Injury and Diffuse Axonal Injury in Swine  

PubMed Central

Abstract Until recently, mild traumatic brain injury (mTBI) or “concussion” was generally ignored as a major health issue. However, emerging evidence suggests that this injury is by no means mild, considering it induces persisting neurocognitive dysfunction in many individuals. Although little is known about the pathophysiological aspects of mTBI, there is growing opinion that diffuse axonal injury (DAI) may play a key role. To explore this possibility, we adapted a model of head rotational acceleration in swine to produce mTBI by scaling the mechanical loading conditions based on available biomechanical data on concussion thresholds in humans. Using these input parameters, head rotational acceleration was induced in either the axial plane (transverse to the brainstem; n=3), causing a 10- to 35-min loss of consciousness, or coronal plane (circumferential to the brainstem; n=2), which did not produce a sustained loss of consciousness. Seven days following injury, immunohistochemical analyses of the brains revealed that both planes of head rotation induced extensive axonal pathology throughout the white matter, characterized as swollen axonal bulbs or varicosities that were immunoreactive for accumulating neurofilament protein. However, the distribution of the axonal pathology was different between planes of head rotation. In particular, more swollen axonal profiles were observed in the brainstems of animals injured in the axial plane, suggesting an anatomic substrate for prolonged loss of consciousness in mTBI. Overall, these data support DAI as an important pathological feature of mTBI, and demonstrate that surprisingly overt axonal pathology may be present, even in cases without a sustained loss of consciousness.

Browne, Kevin D.; Chen, Xiao-Han; Meaney, David F.

2011-01-01

306

Mortality after Hospitalization with Mild, Moderate, and Severe Hyponatremia  

PubMed Central

BACKGROUND Hyponatremia is the most common electrolyte abnormality in hospitalized individuals. METHODS To investigate the association between serum sodium concentration and mortality, we conducted a prospective cohort study of 98,411 adults hospitalized between 2000 and 2003 at 2 teaching hospitals in Boston, Massachusetts. The main outcome measures were in-hospital, 1-year, and 5-year mortality. Multivariable logistic regression and Cox proportional hazards models were used to compare outcomes in patients with varying degrees of hyponatremia against those with normal serum sodium concentration. RESULTS Hyponatremia (serum sodium concentration <135 mEq/L) was observed in 14.5% of patients on initial measurement. Compared with patients with normonatremia (135–144 mEq/L), those with hyponatremia were older (67.0 vs 63.1 years, P <.001) and had more comorbid conditions (mean Deyo-Charlson Index 1.9 vs 1.4, P <.001). In multivariable-adjusted models, patients with hyponatremia had an increased risk of death in hospital (odds ratio 1.47, 95% confidence interval [CI], 1.33–1.62), at 1 year (hazard ratio 1.38, 95% CI, 1.32–1.46), and at 5 years (hazard ratio 1.25, 95% CI, 1.21–1.30). The increased risk of death was evident even in those with mild hyponatremia (130–134 mEq/L; odds ratio 1.37, 95% CI, 1.23–1.52). The relationship between hyponatremia and mortality was pronounced in patients admitted with cardiovascular disease, metastatic cancer, and those admitted for procedures related to the musculoskeletal system. Resolution of hyponatremia during hospitalization attenuated the increased mortality risk conferred by hyponatremia. CONCLUSION Hyponatremia, even when mild, is associated with increased mortality.

Waikar, Sushrut S.; Mount, David B.; Curhan, Gary C.

2011-01-01

307

Testosterone and Bioavailable Testosterone Help to Distinguish between Mild Cushing's Syndrome and Polycystic Ovarian Syndrome*  

PubMed Central

Women with Cushing’s syndrome (CS) and polycystic ovarian syndrome (PCOS) may present with similar symptoms. Subjects with mild CS lack clinical stigmata of classical CS and often have normal laboratory tests measuring hypercortisolism. Thus, distinguishing mild CS from PCOS may be difficult. We hypothesized that either total testosterone (TT) or bioavailable testosterone (BT) levels or the calculation of the free androgen index (FAI) would be low in patients with mild CS and elevated in patients with PCOS, and could help differentiate the two conditions. TT, BT, and FAI were measured in a group of 20 patients of reproductive age with mild CS and 20 PCOS patients matched for age and BMI. We used receiver operator characteristic (ROC) curves to assess the sensitivity and specificity of these measurements for the diagnosis of CS. TT (p<0.0001), BT (p=0.02), and FAI (p=0.003) were significantly elevated in PCOS patients compared to mild CS patients. Sex hormone-binding globulin was similar in both groups. The optimal cut-point for TT was 1.39 nmol/L, yielding a sensitivity of 95 % and a specificity of 70%. The cut-point for BT was 0.24 nmol/L, resulting in a sensitivity of 75 % and a specificity of 80%. The cut-point for FAI was 5.7, with a sensitivity of 88 % and a specificity of 60 %. We conclude that TT levels may be useful to discriminate between mild CS and PCOS. In patients with signs and symptoms consistent with CS and PCOS, a TT level of <1.39nmol/L warrants a workup for CS.

Pall, M. E.; Lao, M. C.; Patel, S. S.; Lee, M. L.; Ghods, D. E.; Chandler, D. W.; Friedman, T. C.

2010-01-01

308

Effect of variable conditions on steam reforming and aqueous phase reforming of n-butanol over Ni/CeO2 and Ni/Al2O3 catalysts  

NASA Astrophysics Data System (ADS)

A comparison of aqueous phase reforming (APR) and steam reforming (SR) of n-butanol (n-BuOH) over Ni(20 wt%) loaded Al2O3 and CeO2 catalysts has been discussed in this paper. The BuOH conversion increases as the system pressure decreases in APR and SR. For both catalysts, the H2 and CO2 selectivity increased as the pressure increased in SR, reached a maximum at the bubble point pressure, and then decreased in the APR region. The Ni/CeO2 catalyst demonstrated higher selectivity for H2 and CO2than the Ni/Al2O3 catalyst during SR, which are consistent with the results of our previous publication on APR of n-butanol (n-BuOH) over similar catalysts. Unlike in APR, the Ni/CeO2 catalyst produced CO in SR. For both of the catalysts, the activation energies for H2 and CO2 production and BuOH conversion were lower in SR than that in APR. The proposed primary reaction pathway for reforming of BuOH on both catalysts is the same for APR and SR. The n-BuOH dehydrogenated to butaldehyde followed by decarbonylation to propane. Then the propane is steam reformed to hydrogen and carbon monoxide. The CO converts to CO2 mostly through water gas shift.

Roy, B.; Sullivan, H.; Leclerc, C. A.

2014-12-01

309

Continuous aqueous tritium monitor  

DOEpatents

An apparatus for a selective on-line determination of aqueous tritium concentration is disclosed. A moist air stream of the liquid solution being analyzed is passed through a permeation dryer where the tritium and moisture are selectively removed to a purge air stream. The purge air stream is then analyzed for tritium concentration, humidity, and temperature, which allows computation of liquid tritium concentration. 2 figs.

McManus, G.J.; Weesner, F.J.

1987-10-19

310

Purification of aqueous effluents  

SciTech Connect

Raw synthesis gases produced by the gasification of coal are treated to remove tars and oils by direct and indirect cooling to produce condensate streams which are treated under high pressure viz 5 to 150 bar to rapidly separate out aqueous and organic phases. Elevated temperatures may then be used to further minimize residence time. The invention is further characterized in that the size of the separation vessels is of several orders of magnitude smaller than used in conventional ambient pressure separation procedures.

Wild, K.R.

1985-04-23

311

Solubilization of native integral membrane proteins in aqueous buffer by noncovalent chelation with monomethoxy poly(ethylene glycol) (mPEG) polymers.  

PubMed

Highly hydrophobic integral membrane proteins (IMPs)are typically purified in excess detergent media, often resulting in rapid inactivation and denaturation of the protein. One promising approach to solve this problem is to couple hydrophilic polymers, such as monomethoxypolyethylene glycol (mPEG) to IMPs under mild conditions in place of detergents. However, the broad application of this approach is hampered by poor reaction efficiencies, low tolerance of detergent stabilized membrane proteins to reaction conditions, and a lack of proper site-specific reversible approaches. Here, we have developed a straightforward, efficient, and mild approach to site-specific noncovalent binding of long-chain polymers to recombinant IMPs. This method uses the hexa-histidine tag (His-Tag) often used for purification of recombinant proteins as an attachment site for mPEGs. Solubility studies performed using five different IMPs confirmed that all tested mPEG-bound IMPs were completely soluble and stable in detergent free aqueous buffer compared to their precipitated native proteins under the identical circumstances. Activity assays and circular dichroism (CD) spectroscopy confirmed the structural integrity of modified IMPs. PMID:21740061

Janaratne, Thamara K; Okach, Linda; Brock, Ansgar; Lesley, Scott A

2011-08-17

312

Solubilization of native integral membrane proteins in aqueous buffer by non-covalent chelation with monomethoxy polyethylene glycol (mPEG) polymers  

PubMed Central

Highly hydrophobic integral membrane proteins (IMPs) are typically purified in excess detergent media, often resulting in rapid inactivation and denaturation of the protein. One promising approach to solve this problem is to couple hydrophilic polymers, such as monomethoxypolyethylene glycol (mPEG) to IMPs under mild conditions in place of detergents. However, the broad application of this approach is hampered by poor reaction efficiencies, low tolerance of detergent stabilized membrane proteins to reaction conditions and a lack of proper site-specific reversible approaches. Here we have developed a straightforward, efficient and mild approach to site-specific non-covalent binding of long-chain polymers to recombinant IMPs. This method uses the hexa-histidine tag (His-Tag) often used for purification of recombinant proteins as an attachment site for mPEGs. Solubility studies performed using five different IMPs confirmed that all tested mPEG-bound IMPs were completely soluble and stable in detergent free aqueous buffer compared to their precipitated native proteins under the identical circumstances. Activity assays and circular dichroism (CD) spectroscopy confirmed the structural integrity of modified IMPs.

Janaratne, Thamara K.; Okach, Linda; Brock, Ansgar; Lesley, Scott A.

2011-01-01

313

Adsorption of dyestuff from aqueous solutions through oxalic acid-modified swede rape straw: adsorption process and disposal methodology of depleted bioadsorbents.  

PubMed

Swede rape straw (Brassica napus L.) was modified by oxalic acid under mild conditions producing an efficient dye adsorbent (SRSOA). This low-cost and environmental friendly bioadsorbent was characterized by various techniques and then applied to purify dye-contaminated aqueous solutions. Equilibrium study showed that the Langmuir model demonstrated the best fit to the equilibrium data and the methylene blue (MB) adsorption capacity calculated by this model was 432mgg(-1). The adsorption process and mechanism is also discussed. To properly deal with the dye-loaded bioadsorbents, the disposal methodology is discussed and a biochar based on depleted bioadsorbents was for the first time produced and examined. This method both solved the disposal problem of contaminant-loaded bioadsorbents and produced an useful adsorbent thereafter. The study indicates that SRSOA is a promising substitute for ACs in purifying dye-contaminated wastewater and that producing biochars from contaminant-loaded bioadsorbents maybe a feasible disposal method. PMID:23612179

Feng, Yanfang; Dionysiou, Dionysios D; Wu, Yonghong; Zhou, Hui; Xue, Lihong; He, Shiying; Yang, Linzhang

2013-06-01

314

The metal tin promoted cascade reaction of ketones in aqueous media for the construction of 2-bromo-4-aryl-1,3-pentadiene.  

PubMed

A novel type of transformation was discovered serendipitously during the Barbier-type allenylation reaction of aromatic ketones promoted by the metal, tin, in aqueous media. Additionally, a series of new, highly functionalized 2-bromo-4-aryl-1,3-pentadienes could be obtained with good yields in this reaction. This cascade reaction shows the unique properties of the metal, tin. Furthermore, it is actually a cascade reaction which involves two steps: one is the Barbier-type allenylation of the carbonyl compound, and the other is an SN2' type addition-elimination reaction. Notably, this reaction has the advantages of simple, mild conditions and is easy to operate. Furthermore, the corresponding product could be applied to various coupling reactions or other diversified transformations. PMID:24931775

Liu, Lingyan; Zhang, Yan; Zhang, Hua; Huang, Kaimeng; Gao, Bo-Xin; Zou, Min; Zhou, Xin; Wang, Hongkai; Li, Jing

2014-07-01

315

Dissolution of malachite in aqueous ethylenediaminetetraacetate solution  

Microsoft Academic Search

The kinetics of malachite dissolution in aqueous ethylenediaminetetraacetate (EDTA) solution has been investigated in the\\u000a temperature range of 298 to 318 K. The dissolution rate of malachite determined under the present set of experimental conditions\\u000a was found to be independent of agitation speed. The dissolution rate increased with increasing EDTA concentration, but leveled\\u000a off at higher concentrations. At constant EDTA

Yasuhiro Awakura; Tetsuji Hirato; Akihiko Kagawa; Yoshiyasu Yamada; Hiroshi Majima

1991-01-01

316

Effect of acute mild dehydration on cognitive-motor performance in golf.  

PubMed

Whether mild dehydration (-1 to 3% body mass change [?BM]) impairs neurophysiological function during sport-specific cognitive-motor performance has yet to be fully elucidated. To investigate this within a golfing context, 7 low-handicap players (age: 21 ± 1.1 years; mass: 76.1 ± 11.8 kg; stature: 1.77 ± 0.07 m; handicap: 3.0 ± 1.2) completed a golf-specific motor and cognitive performance task in a euhydrated condition (EC) and dehydrated condition (DC) (randomized counterbalanced design; 7-day interval). Dehydration was controlled using a previously effective 12-hour fluid restriction, monitored through ?BM and urine color assessment (UCOL). Mild dehydration reduced the mean BM by 1.5 ± 0.5% (p = 0.01), with UCOL increasing from 2 (EC) to 4 (DC) (p = 0.02). Mild dehydration significantly impaired motor performance, expressed as shot distance (114.6 vs. 128.6 m; p < 0.001) and off-target accuracy (7.9 vs. 4.1 m; p = 0.001). Cognitive performance, expressed as the mean error in distance judgment to target increased from 4.1 ± 3.0 m (EC) to 8.8 ± 4.7 m (DC) (p < 0.001). The findings support those of previous research that indicates mild dehydration (-1 to 2% ?BM) significantly impairs cognitive-motor task performance. This study is the first to show that mild dehydration can impair distance, accuracy, and distance judgment during golf performance. PMID:22190159

Smith, Mark F; Newell, Alex J; Baker, Mistrelle R

2012-11-01

317

Low Elevated Lead Levels and Mild Mental Retardation.  

ERIC Educational Resources Information Center

To investigate the relation between low level lead absorption and mild mental retardation, hair lead concentrations were compared in a group of 40 mildly retarded children "etiology unknown" with a control group of 20 children. Children with probable cause for retardation were excluded from the sample as were children with a history of lead…

Marlowe, Mike; And Others

318

Deficits in predictive smooth pursuit after mild traumatic brain injury  

Microsoft Academic Search

Given that even mild traumatic brain injury (TBI) may produce extensive diffuse axonal injury (DAI), we hypothesized that mild TBI patients would show deficits in predictive smooth pursuit eye movements (SPEM), associated with impaired cognitive functions, as these processes are dependent on common white matter connectivity between multiple cerebral and cerebellar regions. The ability to predict target trajectories during SPEM

Minah Suh; Rachel Kolster; Ranjeeta Sarkar; Bruce McCandliss; Jamshid Ghajar

2006-01-01

319

Mild Aphasia: Is This the Place for an Argument?  

ERIC Educational Resources Information Center

Purpose: Individuals with mild aphasia often report significant disruption to their communication despite seemingly minor impairment. This study explored this phenomenon through examining conversations of a person with mild aphasia engaging in argumentation--a skill she felt had significantly deteriorated after her stroke. Method: A person with…

Armstrong, Elizabeth; Fox, Sarah; Wilkinson, Ray

2013-01-01

320

Impaired Verb Fluency: A Sign of Mild Cognitive Impairment  

ERIC Educational Resources Information Center

We assessed verb fluency vs. noun and letter-based fluency in 199 subjects referred for cognitive complaints including Subjective Cognitive Impairment, Mild Cognitive Impairment, and Alzheimer's disease. ANCOVAs and factor analyses identified verb, noun, and letter-based fluency as distinct tasks. Verb fluency performance in Mild Cognitive…

Ostberg, Per; Fernaeus, Sven-Erik; Hellstrom, Ake; Bogdanovic, Nenad; Wahlund, Lars Olof

2005-01-01

321

Probabilistic sequence learning in mild cognitive impairment  

PubMed Central

Mild Cognitive Impairment (MCI) causes slight but noticeable disruption in cognitive systems, primarily executive and memory functions. However, it is not clear if the development of sequence learning is affected by an impaired cognitive system and, if so, how. The goal of our study was to investigate the development of probabilistic sequence learning, from the initial acquisition to consolidation, in MCI and healthy elderly control groups. We used the Alternating Serial Reaction Time task (ASRT) to measure probabilistic sequence learning. Individuals with MCI showed weaker learning performance than the healthy elderly group. However, using the reaction times only from the second half of each learning block—after the reactivation phase—we found intact learning in MCI. Based on the assumption that the first part of each learning block is related to reactivation/recall processes, we suggest that these processes are affected in MCI. The 24-h offline period showed no effect on sequence-specific learning in either group but did on general skill learning: the healthy elderly group showed offline improvement in general reaction times while individuals with MCI did not. Our findings deepen our understanding regarding the underlying mechanisms and time course of sequence acquisition and consolidation.

Nemeth, Dezso; Janacsek, Karolina; Kiraly, Katalin; Londe, Zsuzsa; Nemeth, Kornel; Fazekas, Kata; Adam, Ilona; Elemerne, Kiraly; Csanyi, Attila

2013-01-01

322

Glanzmann's thrombasthenia with mild von Willebrand's disease.  

PubMed Central

A Saudi Arabian family is reported in which Glanzmann's thrombasthenia and von Willebrand's disease occurred simultaneously. The daughter presented with menorrhagia and gave a history of gastrointestinal bleeding and a strong family history of bleeding disorder. Full haematological investigations were performed on the propositus, parents, and siblings, including complete blood count, bleeding time, prothrombin time, partial thromboplastin time, factor VIII:C, von Willebrand factor, ristocetin cofactor, platelet aggregometry, platelet glycoprotein Ib and IIb/IIIa and platelet antigen PLT-1 (Coulter Clone). The propositus had Glanzmann's thrombasthenia, both parents had mild von Willebrand's disease and were carriers of Glanzmann's thrombasthenia. Three symptomatic brothers had both Glanzmann's thrombasthenia and von Willebrand's disease; two asymptomatic brothers had von Willebrand's disease only and one had completely normal results. Those family members with both diseases were more severely affected than those with just one disease. In areas where consanguineous marriage is common, such as Saudi Arabia, multiple haemostatic abnormalities may occur, and investigation should not stop with the discovery of a single abnormality. The increased clinical severity of bleeding, including haemarthroses, in those patients having both congenital defects emphasises the importance of von Willebrand factor in glycoprotein Ib-mediated platelet adhesion.

Nounou, R; Spence, D

1993-01-01

323

Mild coal pretreatment to improve liquefaction reactivity  

SciTech Connect

This report describes work completed during the fifth quarter of a three year project to study the effects of mild chemical pretreatment on coal dissolution reactivity during low severity liquefaction or coal/oil coprocessing. The overall objective of this research is to elucidate changes in the chemical and physical structure of coal by pretreating with methanol or other simple organic solvent and a trace amount of hydrochloric acid and measure the influence of these changes on coal dissolution reactivity. Work this quarter focused on analytical characterization of untreated and treated Wyodak subbituminous coal and Illinois {number sign}6 bituminous coal. Mossbauer spectroscopy and x-ray diffraction techniques were used to study the effect of methanol/HCl pretreatment on the composition of each coal's inorganic phase. Results from these studies indicated that calcite is largely removed during pretreatment, but that other mineral species such as pyrite are unaffected. This finding is significant, since calcite removal appears to directly correlate with low severity liquefaction enhancement. Further work will be performed to study this phenomenon in more detail.

Miller, R.L.

1991-01-01

324

Mild Cognitive Impairment: Pathology and mechanisms  

PubMed Central

Mild cognitive impairment (MCI) is rapidly becoming one of the most common clinical manifestations affecting the elderly. The pathologic and molecular substrate of people diagnosed with MCI is not well established. Since MCI is a human specific disorder and neither the clinical nor the neuropathological course appears to follows a direct linear path, it is imperative to characterize neuropathology changes in the brains of people who came to autopsy with a well-characterized clinical diagnosis of MCI. Herein, we discuss findings derived from clinical pathologic studies of autopsy cases with various subtypes of MCI antemortem. The heterogeneity of clinical MCI imparts significant challenges to any review of this subject. The pathologic substrate of MCI is equally complex and must take into account not only conventional plaque and tangle pathology but also a wide range of cellular biochemical and molecular deficits many of which relate to cognitive decline as well as compensatory responses to the progressive disease process. The multifaceted nature of the neuronal disconnection syndrome associated with MCI, suggests that there is no single event, which precipitates this prodromal stage of AD. In fact, it can be argued that neuronal degeneration initiated at different levels of the central nervous system drive cognitive decline as a final common pathway at this stage of the dementing disease process.

Mufson, Elliott J.; Binder, Lester; Counts, Scott E.; DeKosky, Steven T.; deTolledo-Morrell, Leyla; Ginsberg, Stephen D.; Ikonomovic, Milos D.; Perez, Sylvia E.; Scheff, Stephen W.

2012-01-01

325

Mild cognitive impairment: a concept in evolution.  

PubMed

The construct of mild cognitive impairment (MCI) has evolved over the past 10 years since the publication of the new MCI definition at the Key Symposium in 2003, but the core criteria have remained unchanged. The construct has been extensively used worldwide, both in clinical and in research settings, to define the grey area between intact cognitive functioning and clinical dementia. A rich set of data regarding occurrence, risk factors and progression of MCI has been generated. Discrepancies between studies can be mostly explained by differences in the operationalization of the criteria, differences in the setting where the criteria have been applied, selection of subjects and length of follow-up in longitudinal studies. Major controversial issues that remain to be further explored are algorithmic versus clinical classification, reliability of clinical judgment, temporal changes in cognitive performances and predictivity of putative biomarkers. Some suggestions to further develop the MCI construct include the tailoring of the clinical criteria to specific populations and to specific contexts. The addition of biomarkers to the clinical phenotypes is promising but requires deeper investigation. Translation of findings from the specialty clinic to the population setting, although challenging, will enhance uniformity of outcomes. More longitudinal population-based studies on cognitive ageing and MCI need to be performed to clarify all these issues. PMID:24605806

Petersen, R C; Caracciolo, B; Brayne, C; Gauthier, S; Jelic, V; Fratiglioni, L

2014-03-01

326

Mild parkinsonian signs in a community-dwelling elderly population sample in Japan.  

PubMed

Mild parkinsonian signs (MPS) may represent the mild end of a disease spectrum that spans from normal aging to neurodegenerative diseases. We conducted a population-based study in a rural island town in western Japan, Ama-cho. Participants included 1129 subjects, aged 60 years and older, residing in the town. Participants were classified according to a modified Unified Parkinson's Disease Rating Scale (mUPDRS) score. MPS was determined to be present if any of the following conditions were met: (1) two or more mUPDRS ratings=1 [MPS-mild]; (2) one mUPDRS rating?2; or (3) mUPDRS rest tremor rating?1; [(2) and (3): MPS-severe]. Subjects wore a uniaxial accelerometer (Actiwatch), resulting in the measurement of actigraphic activity counts (AC). Of the 804 participants with complete data, 178 subjects (22.1%) were classified as demonstrating MPS. AC was significantly lower in the MPS-severe group compared with both the CTL and the MPS-mild groups. Diagnostic sensitivity for MPS-severe became 100% when we adopted a cutoff point of low physical activity, as measured by actigraphy, combined with the presence of subjective depression. We established the prevalence of MPS in a community-dwelling elderly population sample in Japan. Actigraphy may be a useful objective tool for screening MPS-severe. PMID:21377694

Uemura, Yusuke; Wada-Isoe, Kenji; Nakashita, Satoko; Nakashima, Kenji

2011-05-15

327

[Toxicity studies of mild gasification products]. [Quarterly report, October 1, 1992--December 31, 1992  

SciTech Connect

Mild gasification of coal is a technology being developed by the United States Department of Energy and private industry with the hope that a cleaner method of coal use can help meet future energy needs. As the technology develops and its commercial use becomes a more viable possibility, efforts are being made to study the safety or possible toxicity of the mild gasification products. DOE and the National Institute for occupational Safety and Health (NIOSH) are cooperating through an interagency agreement to examine some of these products for their genotoxic potential. NIOSH has studied the mutagenicity of several mild gasification product samples using the Ames Salmonella/microsomal assay. As reported earlier PSIS{number_sign}830331 failed to demonstrate genotoxic activity in the Ames assay under all conditions tested. Since the mild gasification products are complex mixtures, interactions between various components are likely to occur. Such interactions between various components of complex mixtures may increase or decrease genotoxic activity in short-term assays like the Ames test. Although all synergistic interactions may not be detailed, the separate analysis of those components in several classes provides a more accurate view of the genotoxicity of each component and better allows for chemical characterization of the possible mutagens in the mixture. NIOSH has performed mutagenicity studies on the subfractions of PSIS{number_sign}830331. The results of those studies are detailed in this report.

Not Available

1992-12-31

328

Mild fetal lateral cerebral ventriculomegaly: clinical course and outcome.  

PubMed

The neonatal, pathologic outcome and karyotypic abnormalities are reported for 44 fetuses with mild ventriculomegaly diagnosed antenatally. Seventeen of these 44 fetuses (39%) had other ultrasonographic defects, and five (12%) had abnormal karyotypes. Five pregnancies were electively aborted and three other fetuses died in the neonatal period. Twenty-six (72%) of the remaining 36 live-born neonates are developmentally and clinically normal at 3 to 18 months of age. Twenty-one of these 26 had isolated mild ventriculomegaly as the only ultrasonographic finding. The other 10 live-born infants are developmentally impaired, and five of these 10 had mild ventriculomegaly as the only prenatal ultrasonographic abnormality. In conclusion, these data show that fetuses with mild ventriculomegaly have a lower incidence of associated anomalies and a better outcome than fetuses with more severe ventricular dilatation, as reported in the literature. The majority of fetuses with mild ventriculomegaly as an isolated finding and a normal karyotype are developing normally. PMID:2003552

Bromley, B; Frigoletto, F D; Benacerraf, B R

1991-03-01

329

Characterization of the corrosion products formed on mild steel in acidic medium with N-octadecylpyridinium bromide as corrosion inhibitor  

NASA Astrophysics Data System (ADS)

The characterization of the corrosion products formed on mild steel SAE 1018 after 2 months exposure in aqueous sulfuric acid with and without corrosion inhibitor N-octadecylpyridinium bromide has been carried out by means of transmission 57Fe Mössbauer spectroscopy and X-ray powder diffraction (XRD). The major constituent of the rust formed in this environment without corrosion inhibitor is goethite ( ?-FeOOH). The samples with N-octadecylpyridinium bromide contain rozenite and large amounts of melanterite in the corrosion layers.

Nava, N.; Likhanova, N. V.; Olivares-Xometl, O.; Flores, E. A.; Lijanova, I. V.

2011-11-01

330

Flow measurements in a model of the mildly curved femoral artery of man  

NASA Technical Reports Server (NTRS)

The effects of curvature on the flow rate near the wall in the vicinity of the mildly curved femoral artery of man, and on the pressure distributions along the curved segment, were investigated using glass and tygon flow models constructed to conform to the shape of the femoral angiogram of a human subject. The test fluid was 33 percent aqueous sucrose. Steady flow observations, made using a dye flow visualization system, revealed a flow pattern like that observed in coiled pipes. A double helical type flow was found to develop, with converging streamlines in the wall vicinity from the upper and lower plane of curvature merging asymptotically along the inner curvature in a stable manner. Pressure measurements for steady flow revealed progressively larger pressure drops with distance along the entrance region of the curved segment, relative to that for a straight lumen.

Back, L. H.; Kwack, E. Y.; Crawford, D. W.

1990-01-01

331

An Adaptive Finite Difference Solver for Nonlinear Two-Point Boundary Problems with Mild Boundary Layers  

Microsoft Academic Search

A variable-order finite difference solver for first-order nonlinear system subject to two-point boundary conditions is described. The method uses deferred corrections, and adaptive meshes are automatically produced in order to detect and resolve mild boundary layers and other sharp-gradient situations. A set of numerical examples solved with an implementation of the algorithm is presented, together with comparisons with several other

M. Lentini; V. Pereyra

1977-01-01

332

Mild, efficient and rapid O-debenzylation of ortho-substituted phenols with trifluoroacetic acid  

Microsoft Academic Search

The mild and efficient deblocking of aryl benzyl ethers with TFA is reported. Cleavage was fastest with ortho-electron-withdrawing groups on the phenolic ring, which we have attributed to a proton chelation effect, furnishing the deprotected phenols in excellent yields. The corresponding para-methoxybenzyl, allyl and iso-propyl ethers were also cleanly removed under these conditions. In addition, the selective aryl benzyl ether

Steven Fletcher; Patrick T. Gunning

2008-01-01

333

A mild, one-pot preparation of 1,3,4-oxadiazoles  

Microsoft Academic Search

A mild and efficient one-pot protocol for the synthesis of 1,3,4-oxadiazoles from carboxylic acids and acylhydrazides was developed. Diacylhydrazide formation via HATU coupling followed by addition of Burgess reagent afforded the corresponding 1,3,4-oxadiazoles in 63–96% yields at room temperature. The reaction conditions are tolerant of a variety of functional groups, including esters, nitriles, alkynes, olefins, alkyl halides, phenols, carbamates and

Changkun Li; Hamilton D. Dickson

2009-01-01

334

No Effect of PTSD and Other Psychiatric Disorders on Cognitive Functioning in Veterans With Mild TBI  

Microsoft Academic Search

There has been speculation that post-traumatic stress disorder (PTSD) superimposed on mild traumatic brain injury (mTBI) may have synergistic, negative effects on cognitive functioning. The purpose of this study was to investigate differences in processing speed, executive functioning, and memory of 82 veterans with mTBI and PTSD, mTBI, and another psychiatric condition, or mTBI alone. It was hypothesized that there

Shalanda N. Gordon; Pamela J. Fitzpatrick; Robin C. Hilsabeck

2011-01-01

335

Mild hydrocracking with a catalyst having a narrow pore size distribution  

Microsoft Academic Search

A process is described for simultaneously hydrodesulfurizing, hydrodenitrogenating and mild hydrocracking a hydrocarbon feedstock comprising nitrogen components, sulfur components and feed components boiling above 700°F comprising contacting the feedstock under conditions of elevated temperature and a hydrogen partial pressure less than about 1,500 p.s.i.g. with a particulate catalyst comprising at least one nickel active metal hydrogenation component, at least one

1987-01-01

336

Surface roughness model for machining mild steel with coated carbide tool  

Microsoft Academic Search

This paper presents a study of the development of a surface roughness model for turning of mild steel with coated carbide tools. The model is developed in terms of cutting speed, feed rate and depth of cut, using response surface methodology. Machining tests were carried out with TiN-coated carbide cutting tools under various cutting conditions. First-order and second-order model predicting

Yusuf Sahin; A. Riza Motorcu

2005-01-01

337

Exposure to mild stress enhances the reinforcing efficacy of intravenous heroin self-administration in rats  

Microsoft Academic Search

The effect of a mild footshock on intravenous heroin self-administration was examined in male rats. Animals in the stress condition were exposed to 10 min of intermittent footshock (0.5 mA; 0.5 s on, with a mean off period of 40 s) before each of four daily self-administration sessions. Animals in the control group were not exposed to footshock. Following acquisition

Yavin Shaham; Jane Stewart

1994-01-01

338

Aqueous phase processing of secondary organic aerosol from isoprene photooxidation  

NASA Astrophysics Data System (ADS)

Transport of reactive air masses into humid and wet areas is highly frequent in the atmosphere, making the study of aqueous phase processing of secondary organic aerosol (SOA) very relevant. We have investigated the aqueous phase processing of SOA generated from gas-phase photooxidation of isoprene using a smog chamber. The SOA collected on filters was extracted by water and subsequently oxidized in the aqueous phase either by H2O2 under dark conditions or by OH radicals in the presence of light, using a photochemical reactor. Online and offline analytical techniques including SMPS, HR-AMS, H-TDMA, TD-API-AMS, were employed for physical and chemical characterization of the chamber SOA and nebulized filter extracts. After aqueous phase processing, the particles were significantly more hygroscopic, and HR-AMS data showed higher signal intensity at m/z 44 and a lower signal intensity at m/z 43, thus showing the impact of aqueous phase processing on SOA aging, in good agreement with a few previous studies. Additional offline measurement techniques (IC-MS, APCI-MS2 and HPLC-APCI-MS) permitted the identification and quantification of sixteen individual chemical compounds before and after aqueous phase processing. Among these compounds, small organic acids (including formic, glyoxylic, glycolic, butyric, oxalic and 2,3-dihydroxymethacrylic acid (i.e. 2-methylglyceric acid)) were detected, and their concentrations significantly increased after aqueous phase processing. In particular, the aqueous phase formation of 2-methylglyceric acid and trihydroxy-3-methylbutanal was correlated with the consumption of 2,3-dihydroxy-2-methyl-propanal, and 2-methylbutane-1,2,3,4-tetrol, respectively, and an aqueous phase mechanism was proposed accordingly. Overall, the aging effect observed here was rather small compared to previous studies, and this limited effect could possibly be explained by the lower liquid phase OH concentrations employed here, and/or the development of oligomers observed during aqueous phase processing.

Liu, Y.; Monod, A.; Tritscher, T.; Praplan, A. P.; DeCarlo, P. F.; Temime-Roussel, B.; Quivet, E.; Marchand, N.; Dommen, J.; Baltensperger, U.

2012-07-01

339

Pathways of aqueous Cr(VI) attenuation in a slightly alkaline oxic subsurface  

SciTech Connect

Column experiments combined with geochemical modeling, microscopic inspections and spectroscopic interrogations were conducted with four freshly or naturally aged contaminated sediments with concentrated Cr(VI) waste fluids. The objective was to determine sediment-dependent Cr(VI) desorption extent and rates, Cr(VI) physical location and soil mineral associations, and mechanism(s) of Cr(VI) attenuation under mild alkaline conditions. Results showed that majority of Cr(VI) mass was easily removed from all sediments. Equilibrium site Kd varied from 0 to 0.33 ml g-1 and equilibrium site fraction was greater than 95 %. In addition, long tailings of time-dependent Cr(VI) concentrations above Environmental Protection Agency maximum concentration limit (MCL) of 1.9 µmol L-1, were also observed (kinetic site Kd and desorption reaction half-life varied from 0 to 45 ml g-1, and 76.1 to 126 h, respectively). Aqueous phase pH, particle size distribution and pore water composition contributed to the variability observed among sediments. Microscopic and spectroscopic studies confirmed that Cr was concentrated within fine-grained coatings in small areas rich in phyllosilicates that contained mixed valence [Cr(III)/Cr(VI)]. However, Cr(VI) reduction was neither significant nor complete. The kinetically controlled Cr(VI) desorption may have resulted from the transport (diffusion) of Cr(VI) out of these areas. In summary, at least four pools of Cr(VI) with different leaching behavior might be present in sediments exposed to concentrated waste fluids: i.) The pool of highly mobile and easily removed Cr(VI) (over 95% of total Cr); ii.) The pool of Cr(VI) held in remote sites that provided a long-term continuing source of contaminant Cr; iii.) The pool of reduced immobile Cr(III) which was formed, most likely, by redox reactions of aqueous Cr(VI) and aqueous, sorbed, or structural Fe(II); vi.) The pool of sparingly soluble Cr(VI) phases (e.g., BaCrO4) or solid solutions which did not contribute to the overall Cr(VI) transport under these conditions.

Qafoku, Nikolla; Dresel, P. Evan; McKinley, James P.; Liu, Chongxuan; Heald, Steve M.; Ainsworth, Calvin C.; Phillips, Jerry L.; Fruchter, Jonathan S.

2009-01-21

340

Saccade deficits in amnestic mild cognitive impairment resemble mild Alzheimer's disease.  

PubMed

Alzheimer's disease (AD) is a disorder of progressive memory loss and executive dysfunction. Little is known about the progression from amnestic mild cognitive impairment (aMCI; isolated memory loss) to AD. Studies have found impairments in mild-stage AD and aMCI in specific tests of executive function. Here, we used objective saccade tasks to determine if they can effectively assess executive function deficits otherwise assessed by neuropsychological testing. To determine which executive function deficits the saccade tasks are most sensitive to, we also investigated the relationship between performance on saccade tasks and neuropsychological test scores. Twenty-two aMCI patients (63-90 years), 24 mild AD patients (61-87 years) and 76 healthy controls (60-85 years) performed a battery of neuropsychological tests, and two saccade tasks designed to probe sensory, motor and cognitive function. The prosaccade task requires a fast, automatic saccade toward an eccentric visual stimulus. The antisaccade task requires additional executive processing to inhibit the automatic prosaccade toward the stimulus, so that a voluntary saccade can be initiated to a location opposite the stimulus. Antisaccade performance was impaired similarly in aMCI and AD patients relative to controls; both groups were slower to initiate correct antisaccades and they made more direction errors (erroneous prosaccades), suggesting similar brain deficits. Scores on the Stroop task were inversely correlated with the percentage of short-latency direction errors in the antisaccade task for controls and aMCI patients, whereas other more global measures of executive function were not related to saccade measures in any subject group. Our results show that the antisaccade task is useful for detecting executive dysfunction in aMCI and AD, especially dysfunction in selective attention. Saccade tasks may therefore have potential to assess executive dysfunction when use of neuropsychological tests is not possible. PMID:24890471

Peltsch, Alicia; Hemraj, Alisha; Garcia, Angeles; Munoz, Douglas P

2014-06-01

341

Nicotine treatment of mild cognitive impairment  

PubMed Central

Objective: To preliminarily assess the safety and efficacy of transdermal nicotine therapy on cognitive performance and clinical status in subjects with mild cognitive impairment (MCI). Methods: Nonsmoking subjects with amnestic MCI were randomized to transdermal nicotine (15 mg per day or placebo) for 6 months. Primary outcome variables were attentional improvement assessed with Connors Continuous Performance Test (CPT), clinical improvement as measured by clinical global impression, and safety measures. Secondary measures included computerized cognitive testing and patient and observer ratings. Results: Of 74 subjects enrolled, 39 were randomized to nicotine and 35 to placebo. 67 subjects completed (34 nicotine, 33 placebo). The primary cognitive outcome measure (CPT) showed a significant nicotine-induced improvement. There was no statistically significant effect on clinician-rated global improvement. The secondary outcome measures showed significant nicotine-associated improvements in attention, memory, and psychomotor speed, and improvements were seen in patient/informant ratings of cognitive impairment. Safety and tolerability for transdermal nicotine were excellent. Conclusion: This study demonstrated that transdermal nicotine can be safely administered to nonsmoking subjects with MCI over 6 months with improvement in primary and secondary cognitive measures of attention, memory, and mental processing, but not in ratings of clinician-rated global impression. We conclude that this initial study provides evidence for nicotine-induced cognitive improvement in subjects with MCI; however, whether these effects are clinically important will require larger studies. Classification of evidence: This study provides Class I evidence that 6 months of transdermal nicotine (15 mg/day) improves cognitive test performance, but not clinical global impression of change, in nonsmoking subjects with amnestic MCI.

Kellar, K.; Aisen, P.; White, H.; Wesnes, K.; Coderre, E.; Pfaff, A.; Wilkins, H.; Howard, D.; Levin, E.D.

2012-01-01

342

Absorption Optics of Aqueous Foams  

NASA Astrophysics Data System (ADS)

Aqueous foams are composed of gas bubbles packed together in a small volume of soapy water. The large number of gas-liquid interfaces in foams results in very strong scattering of light, which explains the opaque nature of conventional aqueous foams such as shaving foams and mousse. For dry foams, the interfaces can take the following three forms: the soap films where two bubbles meet, the triangular plateau borders where three soap films meet and the vertices where four plateau borders meet. Previous experiments have shown that most of the scattering occurs from the plateau borders 2,3 and the transport mean free path of light (l*), the bubble radius (R) and the liquid fraction of foam (epsilon) is related through the relation l*=R/(epsilon0.5). To understand the reflection and scattering of light at the gas-bubble interfaces, we study the absorption of photons in the liquid network as a function of the foam absorptivity. We do this to confirm if the time spent by the photons in the liquid phase is proportional to the liquid fraction of the foam. Our results indicate that for a specific range of liquid fractions (0.05 is less than e is less than 0.1), the photons seem to get trapped in the liquid network. This result is independent of the absorptivity of the foam and leads us to conclude that under appropriate conditions, an aqueous foam behaves very much like an optical fiber network. Aqueous foam is generated in the lab by the method of turbulent mixing of N2 gas with a jet of alpha-olefin-sulfonate (AOS) solution. The foam has been made absorbing by dissolving small quantities of rhodamine dye (R = 0.005 g/l, R = 0.01 g/l and R = 0.0124 g/l) in the AOS solution. The transmission of photons through the foams of liquid fractions 0.0297 is less than e is less than 0.35 has been studied using Diffuse Transmission Spectroscopy (DTS). For each liquid fraction, the transport mean free path l* (the length over which the photon travels before it gets completely randomized) has been estimated from DTS experiments on foams with R = 0.0 g/l. In the liquid fraction range 0.05 is less than epsilon is less than 0.1, the ratio is found to be lower than the theoretical prediction. The deviation of the experimental estimates of (la)foam/(la)soln from the solid line leads us to conclude that at 0.05 is less than e is less than 0.1, the foam behaves like an optical fiber network with the photons getting trapped in and then channeled through the plateau borders. We believe that our results may be explained quantitatively by relating the reflectance of light at liquid-gas and gas-liquid interfaces to the average angles of incidence at these interfaces. Additional information is included in the original extended abstract.

Bandyopadhyay, Ranjini; Gittings, Alex; Durian, D. J.

2002-11-01

343

Preconditioning to mild oxidative stress mediates astroglial neuroprotection in an IL-10-dependent manner.  

PubMed

Oxidative stress plays an important role in the pathogenesis of various brain insults, including stroke. Astroglia are the main glial cells that play a fundamental role in maintaining the homeostasis of the CNS. They are important for protection from injury and aid the brain in functional recovery after injuries. It has been shown that the brain can be prepared to withstand an oxidative stress insult by a process known as preconditioning. We used primary astroglial cell culture to investigate whether preconditioning to mild oxidative stress and glucose deprivation (OSGD) can increase both astroglia survival and neuroprotective features. We found that preconditioning astroglia to mild OSGD increases astroglial survival of a second insult through activation of the NF-E2-related factor-2 (Nrf-2) pathway. Moreover, we found that Nrf-2 is highly expressed in adult brain astroglia and that preconditioning to OSGD in vivo, such as in a murine model of ischemic stroke, leads to a significant increase in astroglial Nrf-2 expression. Furthermore, we discovered an increase in neuroprotection, as measured by increased neuronal cell survival, following OSGD in the presence of medium from astroglia exposed to a mild OSGD condition. Interestingly, we discovered a significant increase in astroglial secretion of the anti-inflammatory cytokine IL-10 vs. the pro-inflammatory cytokine IL-1? in mild vs. severe oxidative stress, respectively. We demonstrated that preconditioning astroglia to mild oxidative stress increases neuroprotection in an IL-10-dependent manner. By using tert-butylhydroquinone (tBHQ), a known specific activator of Nrf-2, we found that Nrf-2 can enhance IL-10 expression. Further studies of Nrf-2-mediated cellular pathways in astroglia through IL-10 may provide useful insights into the development of therapeutic interventions following oxidative stress insults such as ischemic stroke. PMID:23313057

Segev-Amzaleg, Niva; Trudler, Dorit; Frenkel, Dan

2013-05-01

344

Nutritional condition of Northern Yellowstone Elk  

USGS Publications Warehouse

Ultrasonography and body condition scoring was used to estimate nutritional condition of northern Yellowstone elk in late winter. Probability of pregnancy was related to body fat, and lactating cows had 50% less fat than non-lactating cows. For mild to normal winters, most of the elk were in good condition.

Cook, R. C.; Cook, J. G.; Mech, L. D.

2004-01-01

345

White Matter Abnormalities in Veterans With Mild Traumatic Brain Injury  

PubMed Central

Objective It has been estimated that 10%–20% of U.S. veterans of the wars in Iraq and Afghanistan experienced mild traumatic brain injury (TBI), mostly secondary to blast exposure. Diffusion tensor imaging (DTI) may detect subtle white matter changes in both the acute and chronic stages of mild TBI and thus has the potential to detect white matter damage in patients with TBI. The authors used DTI to examine white matter integrity in a relatively large group of veterans with a history of mild TBI. Method DTI images from 72 veterans of the wars in Iraq and Afghanistan who had mild TBI were compared with DTI images from 21 veterans with no exposure to TBI during deployment. Conventional voxel-based analysis as well as a method of identifying spatially heterogeneous areas of decreased fractional anisotropy (“potholes”) were used. Veterans also underwent psychiatric and neuropsychological assessments. Results Voxel-based analysis did not reveal differences in DTI parameters between the veterans with mild TBI and those with no TBI. However, the veterans with mild TBI had a significantly higher number of potholes than those without TBI. The difference in the number of potholes was not influenced by age, time since trauma, a history of mild TBI unrelated to deployment, or coexisting psychopathology. The number of potholes was correlated with the severity of TBI and with performance in executive functioning tasks. Conclusions Veterans who had blast-related mild TBI showed evidence of multifocal white matter abnormalities that were associated with severity of the injury and with relevant functional measures. Overall, white matter potholes may constitute a sensitive biomarker of axonal injury that can be identified in mild TBI at acute and chronic stages of its clinical course.

Jorge, Ricardo E.; Acion, Laura; White, Tonya; Tordesillas-Gutierrez, Diana; Pierson, Ronald; Crespo-Facorro, Benedicto; Magnotta, Vincent A.

2014-01-01

346

Tract-Based Spatial Statistics: Application to Mild Cognitive Impairment  

PubMed Central

Rationale and Objectives. The primary objective of the current investigation was to characterize white matter integrity in different subtypes of mild cognitive impairment (MCI) using tract-based spatial statistics of diffusion tensor imaging. Materials and Methods. The study participants were divided into 4 groups of 30 subjects each as follows: cognitively healthy controls, amnestic MCI, dysexecutive MCI, and Alzheimer's disease (AD). All subjects underwent a comprehensive neuropsychological assessment, apolipoprotein E genotyping, and 3-tesla MRI. The diffusion tensor was reconstructed and then analyzed using tract-based spatial statistics. The changes in brain white matter tracts were also examined according to the apolipoprotein E ?4 status. Results. Compared with controls, amnestic MCI patients showed significant differences in the cerebral white matter, where changes were consistently detectable in the frontal and parietal lobes. We found a moderate impact of the apolipoprotein E ?4 status on the extent of white matter disruption in the amnestic MCI group. Patients with AD exhibited similar but more extensive alterations, while no significant changes were observed in dysexecutive MCI patients. Conclusion. The results from this study indicate that amnestic MCI is the most likely precursor to AD as both conditions share significant white matter damage. By contrast, dysexecutive MCI seems to be characterized by a distinct pathogenesis.

Wai, Yau-Yau; Hsu, Wen-Chuin; Fung, Hon-Chung; Lee, Jiann-Der; Chan, Hsiao-Lung; Tsai, Ming-Lun; Lin, Yu-Chun; Wu, Yih-Ru; Ying, Leslie; Wang, Jiun-Jie

2014-01-01

347

Mild pyrolysis, methanolysis and hydrogasification of Gulf Coast lignites  

SciTech Connect

This study has explored the kinetics of mild gasification in the thermogravimetric analysis (TGA) system. Seventy experimental runs have shown the weight loss effects of particle size, heating rate, reactive and non-reactive gas atmosphere. Subsequently, a kinetic model has been used to determine global kinetic parameters of weight loss. Comparison among parameters, i.e., activation energy and preexponential factor show the impact of various process conditions. The sample of Mississippi, Texas and North Dakota lignites were used. The lignites have been pyrolyzed over heating rates ranging from 5/sup 0/C/min to 200/sup 0/C/min in gas atmosphere of helium, hydrogen and methane. No measurable changes in weight loss when particle size was increased from 44/75 ..mu..m to 1.00/1.41 mm. It can be interpreted as no heat and mass transfer limitation or secondary reaction in this particle size range. Gas atmosphere of hydrogen promoted only about 2% increase in weight loss, whereas methane atmosphere caused cracking of methane and deposition of carbon on the sample. Heating rate caused measurable change on activation and pre-exponential factor due to the shifting of maximum weight loss temperature. Gases and tar produced in the fixed-bed reactor experiment were collected. The most obvious difference between pyrolysis in the three different gases can be seen in their fixed-carbon content in the remaining char.

Lieu, K.

1987-01-01

348

Treatment of mild cognitive impairment: rationale, present and future strategies.  

PubMed

Mild cognitive impairment (MCI) is a condition with a high conversion rate to Alzheimer's disease (AD), which justifies early diagnostic and therapeutic interventions. At the moment, treatment strategies for AD could be extrapolated to interventional strategies in MCI. This article reviews currently available symptomatic treatments with acetylcholinesterase inhibitors, putative treatments such as antiglutamatergic drugs, nootropics, antioxidants, anti-inflammatory drugs and still controversial estrogen replacement therapy, and visionary treatments targeting neuropathological substrates of the disease, such as amyloid production and aggregation, phosphorylation of tau, formation of neurofibrillary tangles and apoptosis. Findings from epidemiological studies have expanded our knowledge on risk as well as possible neuroprotective factors and given means to develop preventive strategies with antihyperlipidaemic drugs such as statins. A wide range of suggested treatments and their possible combinations necessitate their efficacy assessment in well-designed randomized clinical trials where the crucial prerequisites are selection of the treatment population and definitions of outcome measures. Prevention and disease-modifying strategies are raising ethical questions because interventions are focused on non-diseased elderly at risk, which means that emphasis should be not only on efficacy but also on long-term safety. PMID:12603254

Jelic, Vesna; Winblad, Bengt

2003-01-01

349

Facile tuning of plasmon bands in hollow silver nanoshells using mild reductant and mild stabilizer.  

PubMed

Hollow silver nanoshells with tunable plasmon bands have been synthesized using Ag2O nanoparticles at an optimized temperature of 20 °C. The plasmon peak has been tuned in a wide range from 460 nm to 605 nm employing a combination of mild reductant and a mild stabilizer, hydrazine hydrate and sodium citrate, respectively. In contrast, the combination of strong reductant and strong stabilizer, NaBH4 and hydrophilic thiols, resulted in limited plasmon tunability (455-510 nm). The differential behaviour is attributed to the change in dynamics of the diffusion-reaction process. For thiols, the effect of free end-groups was quite evident as plasmon peak shifted from 449 nm to 470 nm on replacing thioglycolic acid (HS-CH2-COOH) with mercaptoethanol (HS-CH2-CH2-OH). Transmission electron microscopy (TEM) revealed that the aspect ratio [outer diameter (d)/shell thickness (t)] was 2.8 (d: 40.0 ± 1.6 nm, t: 14.0 ± 1.3 nm) and 5 (d: 84 ± 2.3 nm, t: 16.8 ± 1.9 nm) for the nanoshells exhibiting a plasmon peak at 460 nm and 605 nm, respectively. The crystal phase of nanoshells was found to be face centered cubic (fcc) as deduced from HR-TEM and electron diffraction data. Using the same Ag2O template, morphological transformation from non-porous to mesoporous has also been achieved by simply reversing the order of addition. PMID:23759896

Pattanayak, Satarupa; Priyam, Amiya; Paik, Pradip

2013-08-01

350

A Nationwide Survey of Mild Cognitive Impairment and Dementia, Including Very Mild Dementia, in Taiwan  

PubMed Central

An increasing population of dementia patients produces substantial societal impacts. We assessed the prevalence of mild cognitive impairment (MCI) and all-cause dementia, including very mild dementia (VMD), in Taiwan. In a nationwide population-based cross-sectional survey, participants were selected by computerized random sampling from all 19 Taiwan counties and were enrolled between December 2011 and March 2013. Cases were identified through in-person interviews based on the National Institute on Aging-Alzheimer’s Association clinical criteria. Demographic data and histories involving mental status and function in daily living were collected. The principal objective assessments were the Taiwanese Mental Status Examination and Clinical Dementia Rating. In all, 10,432 people aged 65 years or older (mean age 76.2±6.7, 52.3% women) were interviewed. The age-adjusted prevalence of all-cause dementia was 8.04% (95% CI 7.47–8.61), including a 3.25% (95% CI 2.89–3.61) prevalence of VMD; that of MCI was 18.76% (95% CI 17.91–19.61). Women had a higher prevalence than men of both all-cause dementia (9.71% vs. 6.36%) and MCI (21.63% vs. 15.57%). MCI affects a considerable portion of the population aged 65 and above in Taiwan. The inclusion of VMD yields dementia prevalence rates higher than those previously reported from Taiwan. Old age, female gender, and a low educational level are significant associated factors.

Sun, Yu; Lee, Huey-Jane; Yang, Shu-Chien; Chen, Ta-Fu; Lin, Ker-Neng; Lin, Chung-Chih; Wang, Pei-Ning; Tang, Li-Yu; Chiu, Ming-Jang

2014-01-01

351

Zwitterionic salts as mild organocatalysts for transesterification.  

PubMed

The exothermic reaction of 3,5-bis(trifluoromethyl)phenyl or 4-nitrophenyl isothiocyanate with 4-pyrrolidinopyridine (PPY) gave the corresponding arylaminothiocarbonylpyridinium salts in quantitative yields. These novel zwitterionic salts were effective as organocatalysts for the transesterification reaction of an equimolar mixture of methyl carboxylates and alcohols in hydrocarbons such as heptane and octane under azeotropic reflux conditions with the removal of methanol. In sharp contrast, PPY was inert as a catalyst under the same reaction conditions. PMID:18442240

Ishihara, Kazuaki; Niwa, Masatoshi; Kosugi, Yuji

2008-06-01

352

Mediterranean Diet and Mild Cognitive Impairment  

PubMed Central

Background Higher adherence to the Mediterranean diet (MeDi) may protect from Alzheimer’s disease (AD) but its association with Mild Cognitive Impairment (MCI) has not been explored. Objective To investigate the association between MeDi and MCI. Design, Setting, Patients, Outcomes In a multiethnic community study in New York, we used Cox proportional hazards to investigate the association between adherence to the MeDi (0 – 9 scale; higher scores higher adherence) and (1) incidence of MCI and (2) progression from MCI to AD. All models were adjusted for cohort, age, gender, ethnicity, education, APOE genotype, caloric intake, body mass index and time duration between baseline dietary assessment and baseline diagnosis. Results There were 1393 cognitively normal participants, 275 of whom developed MCI during 4.5 (± 2.7, 0.9–16.4) years of follow-up. Compared to subjects in the lowest MeDi adherence tertile, subjects in the middle MeDi tertile had 17 % (HR, 0.83; 95% CI, 0.62 – 1.12; p=0.24) less risk of developing MCI, while those at the highest MeDi adherence tertile had 28 % (HR, 0.72; 95% CI, 0.52 – 1.00; p=0.05) less risk of developing MCI (trend HR, 0.85; 95% CI, 0.72 – 1.00; p for trend= 0.05). There were 482 subjects with MCI, 106 of whom developed AD during 4.3 (± 2.7, 1.0 – 13.8) years of follow-up. Compared to subjects in the lowest MeDi adherence tertile, subjects in the middle MeDi adherence tertile had 45 % (HR, 0.55; 95% CI, 0.34 – 0.90; p=0.01) less risk of developing AD, while those at the highest MeDi adherence tertile had 48 % (HR, 0.52; 95% CI, 0.30 – 0.91; p=0.02) less risk of developing AD (trend HR, 0.71; 95% CI, 0.53 – 0.95; p for trend= 0.02). Conclusions Higher adherence to the MeDi is associated with a trend for reduced risk for developing MCI and with reduced risk for MCI conversion to AD.

Scarmeas, Nikolaos; Stern, Yaakov; Mayeux, Richard; Manly, Jennifer; Schupf, Nicole; Luchsinger, Jose A.

2009-01-01

353

Mild pyrolysis of selectively oxidized coals. [Quarterly] technical report, March 1, 1992--May 31, 1992  

SciTech Connect

The primary objective of this study is to investigate the removal organic sulfur from selectively oxidized Illinois coals using mild thermal/chemical processes. Work completed this quarter primarily concerned the investigation of the desulfurization of the selectively oxidized coals using aqueous or alcoholic base mixtures. Model compound studies were initiated. Results were: Levels of desulfurization obtained in this study are at, or very close to, the 90% removal levels required for these coals to be in compliance with the Clean Air Act legislation; Up to 89.4% of the sulfur in the IBC 101 coal and 88.9% of the sulfur in the IBC 106 coal has been removed by combining selective oxidation and alcoholic/base reactions; Overall, selective oxidation pretreatment always led to a lower sulfur product than the untreated sample; Substantial enhancement in the reactivity of the sulfur in the coal has been achieved by the selective oxidation pretreatment; The highest levels of desulfurization obtained so far all involve bases as additives; The water/Na{sub 2}CO{sub 3} combination, was superior than any of the aqueous hydroxide bases. Possible synergistic interactions between the alcohol and the base are suspected. Over 70% of the sulfur in the IBC 101 coal can be removed by performing vacuum pyrolysis on the selectively oxidized coal. Lower sulfur contents are obtained by lowing the pyrolysis pressure.

Hippo, E.J.; Palmer, S.R.

1992-10-01

354

Aqueous PUREX Solidification in Saltstone  

Microsoft Academic Search

Saltstone samples prepared with simulated aqueous PUREX blended with salt solution hold tank solution meet the processing (gel time, set time, and bleed water) and compressive strength requirements for Z-Area treatment and disposal. New solvent storage tanks contain approximately 900 gallons and 10,800 gallons of the aqueous PUREX waste, respectively. The Solid Waste Division identified stabilization in Saltstone as the

Cozzi

2003-01-01

355

Synthesis of Aqueous Ferrofluid  

NSDL National Science Digital Library

This video lab manual, by the Interdisciplinary Education Group of the University of Wisconsin â Madison Materials Research Science and Engineering Center (MRSEC), walks students through the process synthesizing aqueous ferrofluids, which "respond to an external magnetic field enabling the solution's location to be controlled through the application of a magnetic field." Each step of the procedure is detailed and accompanied with a video showing it as it is performed. A brief background of the procedure and the necessary safety and laboratory materials are also given. This detailed resource helps students to explore nanotechnology and advanced materials science through hands-on laboratory activities. A printer-friendly version with an example image for each step is also available, perfect for an in-class handout.

Breitzer, Jonathan; Lisensky, George

2009-04-03

356

Transcriptomic analysis of mild hypothermia-dependent alterations during endothelial reperfusion injury.  

PubMed

Background: Mild hypothermia (32-34 degrees C) improves resistance to ischemia-reperfusion (I/R) injury. However, the mechanisms by which it affects human cellular function are not fully elucidated. To further test for hypothermic modulation of global biological processes, we used DNA microarray technique to detect the overall gene expression profile. Methods: Human umbilical endothelial cells (HUVECs) were incubated under control condition (37 degrees C) or mild hypothermia (33 degrees C) for 2 hours after stimulated ischemia. Detection of differentially expressed genes was performed with Affymetrix U133 plus 2.0 arrays and PARTEK software. We used DAVID and KEGG Pathways database to identify global trends in gene expression data. Results: Our analysis has identified numerous interesting genes and processes that are differentially presented in hypothermic group when compared with normothermic control. The cell cycle was the most prominent process; several genes involved in cell apoptosis and proliferation displayed significantly differential expression; lower transcriptional level was observed for genes involved in chemokine and cell adhesion processes; genes associated with activity of transmembrane transporter and lipase were also under-expressed. Conclusion: Our data indicated that mild hypothermia altered endothelial expression pattern under the condition of I/R, preferably through varying the expression of genes associated with cell cycle, apoptosis, proliferation, and inflammatory response. PMID:20511705

Yang, Dan; Zeng, Yong; Tian, Cui; Liu, Jing; Guo, Shu-Bin; Zheng, Yue-Hong; Li, Hui-Hua

2010-01-01

357

Chronic mild stress eliminates the neuroprotective effect of Copaxone after CNS injury.  

PubMed

Copolymer (Cop)-1, also known as glatiramer acetate, is an active compound of Copaxone, a drug widely used by patients with multiple sclerosis (MS). Copaxone functions in MS through two mechanisms of action, namely immunomodulation and neuroprotection. Because the immune system is suppressed or altered in depressed individuals, and since depression is often associated with neurological conditions, we were interested in examining whether the neuroprotective effect of Copaxone persists under conditions of stress-induced depressive behavior. We exposed mice to unpredictable chronic mild stress for 4 weeks and then treated them with three doses of Copaxone at 3-day intervals, with the last dose given immediately before the mice underwent a crush injury to the optic nerve. Whereas nonstressed mice exhibited a strong neuroprotective response after Copaxone treatment, this effect was completely absent in mice that underwent chronic mild stress. Interestingly, when Copaxone was combined with Prozac, the neuroprotective effect of Copaxone was regained, suggesting that chronic mild stress interferes with the neuroprotective effect of Copaxone. These results may shed a light on mechanism of action of Copaxone and lead to new combined therapies for neurodegenerative and neuroinflammatory disorders. PMID:23295266

Smirnov, Igor; Walsh, James T; Kipnis, Jonathan

2013-07-01

358

A mild and efficient method for preparation of azides from alcohols using acidic ionic liquid [H-NMP]HSO 4  

Microsoft Academic Search

We report here an efficient method for the synthesis and characterization of [H-NMP]HSO4 and its application as an efficient catalyst and solvent for preparation of azides from corresponding alcohols under mild conditions. This processor showed high chemoselectivity for conversion of various alcohols to their corresponding azides.

Abdol R. Hajipour; Asiyeh Rajaei; Arnold E. Ruoho

2009-01-01

359

Production of a High-Quality Liquid Fuel from Coal by Mild Pyrolysis of Coal-Lime Mixtures.  

National Technical Information Service (NTIS)

The objective of this investigation is to optimize devolatilization conditions of coal with an aim to increasing product quality and yield. It has been observed that mild devolatilization (heating coal slowly to 500 deg C in a batch reactor) of coal in th...

M. R. Khan

1986-01-01

360

Training of attentional control in mild cognitive impairment with executive deficits: Results from a double-blind randomised controlled study  

Microsoft Academic Search

This study evaluated the efficacy of a cognitive intervention for attentional control in older adults with mild cognitive impairment (MCI) with an executive deficit. It also sought to verify if the benefits of training generalised to primary and secondary outcome measures. Participants (n?=?24) were randomly assigned to a training programme or active control condition. The experimental group completed a computer-based

Lyssa G. Gagnon; Sylvie Belleville

2012-01-01

361

Effects of Concept Mapping Instruction on the Vocabulary Acquisition Skills of Seventh-Graders with Mild Disabilities: A Replication Study  

ERIC Educational Resources Information Center

The present investigation replicates and extends an earlier study comparing 2 conditions, a dictionary approach versus a concept mapping model, on the learning of vocabulary words among 4 students with mild disabilities (i.e., emotional and/or behavioral disorders and other health impairments) attending a middle school. An A-B-A-B design was used…

Palmer, Jessica; Boon, Richard T.; Spencer, Vicky G.

2014-01-01

362

Plasmon-driven sequential chemical reactions in an aqueous environment.  

PubMed

Plasmon-driven sequential chemical reactions were successfully realized in an aqueous environment. In an electrochemical environment, sequential chemical reactions were driven by an applied potential and laser irradiation. Furthermore, the rate of the chemical reaction was controlled via pH, which provides indirect evidence that the hot electrons generated from plasmon decay play an important role in plasmon-driven chemical reactions. In acidic conditions, the hot electrons were captured by the abundant H(+) in the aqueous environment, which prevented the chemical reaction. The developed plasmon-driven chemical reactions in an aqueous environment will significantly expand the applications of plasmon chemistry and may provide a promising avenue for green chemistry using plasmon catalysis in aqueous environments under irradiation by sunlight. PMID:24958029

Zhang, Xin; Wang, Peijie; Zhang, Zhenglong; Fang, Yurui; Sun, Mengtao

2014-01-01

363

Plasmon-driven sequential chemical reactions in an aqueous environment  

PubMed Central

Plasmon-driven sequential chemical reactions were successfully realized in an aqueous environment. In an electrochemical environment, sequential chemical reactions were driven by an applied potential and laser irradiation. Furthermore, the rate of the chemical reaction was controlled via pH, which provides indirect evidence that the hot electrons generated from plasmon decay play an important role in plasmon-driven chemical reactions. In acidic conditions, the hot electrons were captured by the abundant H+ in the aqueous environment, which prevented the chemical reaction. The developed plasmon-driven chemical reactions in an aqueous environment will significantly expand the applications of plasmon chemistry and may provide a promising avenue for green chemistry using plasmon catalysis in aqueous environments under irradiation by sunlight.

Zhang, Xin; Wang, Peijie; Zhang, Zhenglong; Fang, Yurui; Sun, Mengtao

2014-01-01

364

Combined Training Program for Veterans with Amnestic Mild Cognitive Impairment.  

National Technical Information Service (NTIS)

The purpose of the study is to evaluate the efficacy of an exercise training augmentation for cognitive training intervention to improve memory performance in older Veterans with a diagnosis of amnestic Mild Cognitive Impairment (aMCI). The investigators ...

J. K. Fairchild

2013-01-01

365

Treating mild gestational diabetes mellitus: a cost-effectiveness analysis  

PubMed Central

OBJECTIVE This study investigated the cost-effectiveness of treating mild gestational diabetes mellitus (GDM). STUDY DESIGN A decision analytic model was built to compare treating vs not treating mild GDM. The primary outcome was the incremental cost per quality-adjusted life year (QALY). All probabilities, costs, and benefits were derived from the literature. Base case, sensitivity analyses, and a Monte Carlo simulation were performed. RESULTS Treating mild GDM was more expensive, more effective, and cost-effective at $20,412 per QALY. Treatment remained cost-effective when the incremental cost to treat GDM was less than $3555 or if treatment met at least 49% of its reported efficacy at the baseline cost to treat of $1786. CONCLUSION Treating mild GDM is cost-effective in terms of improving maternal and neonatal outcomes including decreased rates of preeclampsia, cesarean sections, macrosomia, shoulder dystocia, permanent and transient brachial plexus injury, neonatal hypoglycemia, neonatal hyperbilirubinemia, and neonatal intensive care unit admissions.

Ohno, Mika S.; Sparks, Teresa N.; Cheng, Yvonne W.; Caughey, Aaron B.

2012-01-01

366

Multidimensional life satisfaction reports of adolescents with mild mental disabilities.  

PubMed

Using the Multidimensional Students' Life Satisfaction Scale-MSLSS(Huebner, 1994), we compared life satisfaction reports of 80 high school students with mild mental disabilities with a matched sample of 80 typically achieving students. The results provided preliminary support for the use of the MSLSS in research with secondary school students with mild mental disabilities. Comparisons of mean levels of general and domain-specific satisfaction suggested that the students with mild mental disabilities reported comparable positive levels with two exceptions. They reported lower satisfaction with their friendships and higher satisfaction with school experiences than did their typically achieving counterparts. The school satisfaction reports of students with mild mental disabilities varied as a function of differences in placement in special education. PMID:12123396

Brantley, Ashley; Huebner, E Scott; Nagle, Richard J

2002-08-01

367

ADHD Symptoms in Children With Mild Intellectual Disability  

Microsoft Academic Search

Objectives:To determine whether the nature and correlates of attention-deficit\\/hyperactivity disorder (ADHD) symptoms are different in subjects with mild intellectual disability (ID) compared to subjects with average ability.

EMILY SIMONOFF; ANDREW PICKLES; NICKY WOOD; PAUL GRINGRAS; OLIVER CHADWICK

2007-01-01

368

Mild intellectual disability associated with a progeny of father-daughter incest: genetic and environmental considerations.  

PubMed

We report the case of a 34-year-old female resulting from a father-daughter sexual abuse and presenting a phenotype of mild intellectual disability with minor dysmorphic features. Karyotyping showed a normal 46, XX constitution. Array-based comparative genomic hybridization (array-CGH) revealed a heterozygote 320kb 6p22.3 microdeletion in the proband, encompassing only one known gene, and therefore unlikely to be the cause of the phenotype. However, the role of other genetic factors, such as a recessive condition, could not be ruled out as a putative cause for the phenotype. On the other hand, the role played by a heavily detrimental familial situation on the development and outcome, and possibly leading or contributing to a mild intellectual disability, should be taken into account. PMID:20509080

Ansermet, Francois; Lespinasse, James; Gimelli, Stefania; Béna, Frédérique; Paoloni-Giacobino, Ariane

2010-05-01

369

Diffusion Tensor Imaging Reveals Acute Subcortical Changes after Mild Blast-Induced Traumatic Brain Injury  

PubMed Central

Mild blast-induced traumatic brain injury (mbTBI) poses special diagnostic challenges due to its overlapping symptomatology with other neuropsychiatric conditions and the lack of objective outcome measures. Diffusion tensor imaging (DTI) can potentially provide clinically relevant information toward a differential diagnosis. In this study, we aimed to determine if single and repeated (5 total; administered on consecutive days) mild blast overpressure exposure results in detectable structural changes in the brain, especially in the hippocampus. Fixed rat brains were analyzed by ex vivo DTI at 2?h and 42 days after blast (or sham) exposure(s). An anatomy-based region of interest analysis revealed significant interactions in axial and radial diffusivity in a number of subcortical structures at 2?h only. Differences between single- and multiple-injured rats were largely in the thalamus but not the hippocampus. Our findings demonstrate the value and the limitations of DTI in providing a better understanding of mbTBI pathobiology.

Kamnaksh, Alaa; Budde, Matthew D.; Kovesdi, Erzsebet; Long, Joseph B.; Frank, Joseph A.; Agoston, Denes V.

2014-01-01

370

Surface Changes in Mild Steel Coupons from the Action of Corrosion-Causing Bacteria  

PubMed Central

Changes which occur on the surface of mild steel coupons submerged in cultures of an Fe(III)-reducing bacterium, isolated from corroded pipe systems carrying crude oil, were studied microscopically to investigate the interaction between the corrosion-causing bacterium and the corroding mild steel coupon. Under micro-aerobic conditions and in the absence of the bacteria, a dense, crystalline, amorphous coat formed on the surface of the steel coupons. In the presence of bacteria the surface coat was extensively removed, exposing the bare metal to the environment. After about 2 weeks of exposure, the removal of the surface coating was followed by colonization of the metal surface by the bacteria. Colonization was mediated by fibrous, exopolysaccharidic material formed by the bacteria. Extension of studies to other bacteria isolated from crude oil and corroded pipes reveals that the formation of exopolysaccharide fibers and possession of adherent properties are common characteristics of bacteria from crude oil systems. Images

Obuekwe, Christian O.; Westlake, Donald W. S.; Cook, Fred D.; William Costerton, J.

1981-01-01

371

Chronic mild prenatal stress exacerbates the allergen-induced airway inflammation in rats.  

PubMed Central

The effects of chronic mild prenatal stress on leukocyte infiltration into the airways was investigated in rat offspring. The chronic prenatal stress consisted of transitory and variable changes in the rat's living conditions. Offspring at adult age were actively sensitized (day 0) and intratracheally challenged (day 14) with ovalbumin. Bronchoalveolar lavage was performed in the offspring at 48 h after intratracheal challenge with ovalbumin. A significant increase in total leukocyte infiltration was observed in the non-stressed offspring group and this was associated with a marked recruitment of eosinophils without a significant effect on the influx of neutrophils and mononuclear cells. In the prenatal stressed offspring, the counts of both total leukocyte and eosinophils, as well as mononuclear cells, was increased by 50% compared to the non-stressed offspring. We provide here the first experimental evidence that chronic mild unpredictable prenatal stress produces a marked increase in the allergen-induced airway inflammation in the rat offspring.

Nogueira, P J; Ferreira, H H; Antunes, E; Teixeira, N A

1999-01-01

372

Novel chloride channel mutations leading to mild myotonia among Chinese  

Microsoft Academic Search

We describe two Chinese families with a mild form of the myotonia congenita due to novel chloride channel (ClCN1) mutations. In one case, heterozygous I553F and H555N mutations were found. The patient shared the I553F mutation with his healthy father, and his mother had a history of mild myotonia when she was younger. In another family, autosomal dominant myotonia congenita

Jean-Marc Burgunder; Shang Huifang; Pascal Beguin; Roland Baur; Chew Soh Eng; Raymond C. S. Seet; Erle C. H. Lim; Benjamin K. C. Ong; Walter Hunziker; Erwin Sigel

2008-01-01

373

The Oxidant-Antioxidant Balance in Mild Asthmatic Patients  

Microsoft Academic Search

We investigated the oxidant-antioxidant balance and the effect of inhaled corticosteroids on this balance in mild stable asthmatics. Included in the study were 30 mild asthmatic patients (11 male, 19 female, mean age (year) ± SD: 35.1 ± 9.7) and 26 healthy adults (7 male, 19 female, mean age (year) ± SD: 40.8 ± 13.3). In all study groups, the

I. Hanta; S. Kuleci; N. Canacankatan; A. Kocabas

2003-01-01

374

Johnson - Cook Strength Models for Mild and DP 590 Steels  

Microsoft Academic Search

Automotive steels, Mild and Dual Phase590 (DP590) are characterized in tension at room temperature, using the quasi-static and split Hopkinson bar techniques at various strain rates ranging from ~10-3\\/s to ~1800\\/s. Tension stress-strain data for both the steels are analyzed to determine the Johnson-Cook Strength model constants, J-C strength model constants for mild steel are A=217 MPa, B = 234

K. Vedantam; D. Bajaj; N. S. Brar; S. Hill

2006-01-01

375

Characterizing and modeling combustion of mild-gasification chars in pressurized fluidized beds  

SciTech Connect

Oak Ridge National Laboratory (ORNL) is supported by the Morgantown Energy Technology Center (METC) of the Department of Energy (DOE) under FWP-FEAA310 to characterize the fuel properties of liquid and char coproducts from the mild gasification of coal, Because most of the energy content of coals subjected to mild gasification is retained in the byproduct char, efficient and cost-effective utilization of the char is essential in insuring that candidate gasification processes are commercially viable. One potential use for char of particular interest to DOE is pressurized fluidized bed combustion (PFBC). PFBC is of particular interest because it has the potential for 10 to 30 percent greater overall energy efficiency than atmospheric fluidized bed combustion (AFBC), While bench-scale tools and analytical procedures for characterizing fuels for AFBC have been recently demonstrated, no such tools have been reliably demonstrated for PFBC. This report summarizes the results of joint research collaboration between ORNL and B&W that has been directed at modifying the previously developed AFBC fuel characterization procedures to be applicable for mild-gasification chars and PFBC conditions. The specific objectives were to: (1) characterize the combustion reactivity of a selected set of candidate mild- gasification chars at PFB conditions; (2) compare the measured char characteristics with those of more conventional PFBC fuels; (3) modify an AFBC computer code previously developed by B&W and ORNL for the Electric Power Research Institute (EPRI) to predict PFBC performance; and (4) apply the modified code and measured char combustion characteristics to make performance predictions for the candidate chars relative to more conventional fuels.

Daw, C.S.

1995-10-01

376

[Induced mild hypothermia to limit neurological damage after resuscitation].  

PubMed

Despite improvements in resuscitation techniques, the prognosis for patients who experience cardiac arrest outside of a hospital remains relatively poor. This is mainly due to brain damage that occurs as a result of global cerebral ischaemia. In 2002, two prospective randomised multicentre studies demonstrated that induced mild hypothermia can increase the chance of good neurologic recovery after out-of-hospital cardiac arrest by at least 40%. For this reason, induced mild hypothermia (32-34 degrees C) was included in the resuscitation guidelines developed by the International Liaison Committee on Resuscitation. Mild hypothermia is relatively easy to apply and has few complications. Compared with normothermia, induced mild hypothermia increases the chance of good neurological recovery by 1.7-fold. A safe and effective method to induce mild hypothermia is the infusion of cold fluids during sedation and mechanical ventilation. Cardiac function, renal function and electrolytes must be monitored closely during induced mild hypothermia. Given the potentially deleterious effects of rapid rewarming, a maximal rewarming rate of 0.5 degrees C per hour is recommended. PMID:18326411

de Pont, A C J M

2008-02-01

377

Depression characteristics among mildly handicapped students  

Microsoft Academic Search

The present study was conducted to determine the prevalence of depressive characteristics among learning disabled, mentally retarded, and behaviorally disordered students. The influence of sex and age on the prevalence within each handicapping condition was also considered. A “depression subscale” of the Behavior Problem Checklistwas administered to 2078 learning disabled students, 705 behaviorally disordered students, and 1184 nonhandicapped students. The

Patrick J. Schloss; Michael H. Epstein; Douglas Cullinan

1988-01-01

378

Development of an advanced continuous mild gasification process for the production of coproducts: Task 4. 6, Technical and economic evaluation  

SciTech Connect

Morgantown Energy Technology Center (METC) of DOE has sponsored, and continues to sponsor, programs for the development of technology and market strategies which will lead to the commercialization of processes for the production of coproducts from mild gasification of coal. It has been recognized by DOE and industry that mild gasification is a promising technology with potential to economically convert coal into marketable products, thereby increasing domestic coal utilization. In this process, coal is devolatilized under non- oxidizing conditions at mild temperature (900--1100{degrees}F) and pressure (1--15psig). Condensation of the vapor will yield a liquid product that can be upgraded to a petroleum substitute, and the remaining gas can provide the fuel for the process. The residual char can be burned in a power plant. Thus, in a long-term national scenario, implementation of this process will result in significant decrease of imported oil and increase in coal utilization.

Hogsett, R.F.; Jha, M.C.

1991-12-01

379

Bentonite for ciprofloxacin removal from aqueous solution.  

PubMed

Ciprofloxacin hydrochloride (CIP) is the second generation of fluoroquinolone antibiotics whose residues are found in wastewater and surface water. CIP has high aqueous solubility under different pH conditions and high stability in the soil system. In this study, bentonite was used as a potential sorbent for the removal of CIP from aqueous solutions using batch experiments. The effects of various parameters such as contact time, pH, adsorbent dosage, agitation speed, ionic strength and initial concentration of CIP in aqueous solution on the adsorption capacity were investigated. The optimum contact time, pH, agitation speed and adsorbent dosage were found to be 30 min, 4.5 pH, 150 rpm and 2.5 g L(-1), respectively. When the ionic strength was increased from 5 to 50 mM, the adsorption of CIP decreased from 97.8 to 93.4%. The isotherm adsorption data fitted well with the Langmuir model, Kl and qe were found to be 0.27 L mg(-1) and 147.06 mg g(-1), and the data fitted well with the pseudo-second order kinetics, whereby k was found to be 2.19 g mg(-1) h(-1). PMID:23985515

Genç, Nevim; Can Dogan, Esra; Yurtsever, Meral

2013-01-01

380

Photolysis of oxyfluorfen in aqueous methanol.  

PubMed

Photolysis of oxyfluorfen, an herbicide of the nitrodiphenyl ether class, was studied in aqueous methanol under UV and sunlight. UV irradiation was carried out in a borosilicate glass photoreactor (containing 250 ppm oxyfluorfen in 50% aqueous methanol) equipped with a quartz filter and 125 watt mercury lamp (maximum output 254 nm) at 25 ± 1°C. Sunlight irradiation was conducted at 28 ± 1°C in borosilicate Erlenmeyer flasks containing 250 ppm oxyfluorfen in 50% aqueous methanol. The samples from both the irradiated conditions were withdrawn at a definite time interval and extracted to measure oxyfluorfen content by gas chromatography-flame ionization detector for rate study. The half-life values were 20 hours and 2.7 days under UV and sunlight exposure, respectively. Photolysis of oxyfluorfen yielded 13 photoproducts of which three were characterized by infrared spectrophotometer and (1)H NMR and (13)C NMR spectroscopy. The rest of the photoproducts were identified by gas chromatography-mass spectrometry (GC-MS) and thin layer chromatography (TLC). An ionization potential 70 eV was used for electron impact-mass spectrometry (EI-MS) and methane was used as reagent gas for chemical ionization-mass spectrometry (CI-MS). Two of the photoproducts were also synthesized for comparison. The main phototransformation pathways of oxyfluorfen involved nitro reduction, dechlorination, and hydrolysis as well as nucleophiles displacement reaction. PMID:23998303

Chakraborty, Subhasish K; Chakraborty, Savitri; Bhattacharyya, Anjan; Chowdhury, Ashim

2013-01-01

381

Aqueous biphasic microprinting approach to tissue engineering  

PubMed Central

We summarize a recently developed microtechnology for printing biomaterials on biological surfaces. The technique is based on the use of immiscible aqueous solutions of two biopolymers and allows spatially defined placement of cells and biomolecules suspended in the denser aqueous phase on existing cell layers and extracellular matrix hydrogel surfaces maintained in the second phase. Printing takes place due to an extremely small interfacial tension and density difference between the two aqueous phases. The contact-free printing process ensures that both printed cells and the underlying cell monolayer maintain full viability and functionality. The technique accommodates both arbitrarily shaped patterns and microarrays of cells and bioreagents. The capability to print cells and small molecules on existing cell layers enables unique interrogations of the effects of cell-cell and cell-material interaction on cell fate and function. Furthermore, the very gentle conditions and the ability to directly pattern nongel embedded cells over cells make this technology appealing to tissue engineering applications where patterned multicellar organization with minimal scaffolding materials is needed, such as in dense tissues of the skeletal muscle and liver.

Tavana, Hossein; Takayama, Shuichi

2011-01-01

382

Effect of induced mild hypothermia on two pro-inflammatory cytokines and oxidative parameters during experimental acute sepsis.  

PubMed

This study aimed to determine the effect of induced mild hypothermia (34°C) on the production of two cytokines (interleukin (IL-6) and tumor necrosis factor (TNF)alpha) and reactive nitrogen and oxygen species in plasma and the heart of acutely septic rats. After anesthesia and in conditions of normothermia (38°C) or mild hypothermia (34°C), acute sepsis was induced by cecal ligation and perforation. For each temperature three groups were formed: (1) baseline (blood sample collected at T0 hour), (2) sham (blood sample at T4 hours) and (3) septic (blood sample at T4 hours). At either temperature sepsis induced a significant increase in plasma IL-6, TNF-alpha and HO• concentration, compared with the sham groups (P?0.016). Compared with the normothermic septic group, septic rats exposed to mild hypothermia showed a mild decrease in TNF-alpha concentration (104±50 pg/ml vs. 215±114 pg/ml; P>0.05) and a significant decrease in IL-6 (1131±402 pg/ml vs. 2494±691 pg/ml, P=0.038). At either temperature sepsis induced no enhancement within the heart of lipoperoxidation (malondialdehyde content) or antioxidant activities (superoxide dismutase and catalase). In conclusion, during acute sepsis, induced mild hypothermia appears to reduce some pro-inflammatory and oxidative responses. This may, in part, explain the beneficial effect of hypothermia on survival duration of septic rats. PMID:23746123

Léon, Karelle; Moisan, Christine; Amérand, Aline; Poupon, Gwladys; L'Her, Erwan

2013-01-01

383

Aqueous chlorination of resorcinol  

USGS Publications Warehouse

An investigation of the aqueous chlorination (NaOCl) of resorcinol is reported. The following intermediates were detected in moderate to high yield at different pH values and varying percentages of chlorination: 2-chloro-, 4-chloro-, 2,4-dichloro-, 4,6-dichloro- and 2,4,6-trichlororesorcinol. Only trace amounts of the intermediates were detected when the chlorination was conducted in the presence of phosphate buffer. This result has significant implications since resorcinol in phosphate buffer has been used as a model compound in several recent studies on the formation of chlorinated hydrocarbons during chlorination of drinking water. Relative rates of chlorination were determined for resorcinol and several of the chlorinated resorcinols. Resorcinol was found to chlorinate only three times faster than 2,4,6-trichlororesorcinol. The structure 2,4,6-trichlororesorcinol was established as a monohydrate even after sublimation. A tetrachloro or pentachloro intermediate was not detected, suggesting that the ring-opening step of such an intermediate must be rapid. ?? 1989.

Heasley, V. L.; Burns, M. D.; Kemalyan, N. A.; Mckee, T. C.; Schroeter, H.; Teegarden, B. R.; Whitney, S. E.; Wershaw, R. L.

1989-01-01

384

Aqueous photolysis of niclosamide  

USGS Publications Warehouse

The photodegradation of [14C]niclosamide was studied in sterile, pH 5, 7, and 9 buffered aqueous solutions under artificial sunlight at 25.0 A? 1.0 A?C. Photolysis in pH 5 buffer is 4.3 times faster than in pH 9 buffer and 1.5 times faster than in pH 7 buffer. In the dark controls, niclosamide degraded only in the pH 5 buffer. After 360 h of continuous irradiation in pH 9 buffer, the chromatographic pattern of the degradates was the same regardless of which ring contained the radiolabel. An HPLC method was developed that confirmed these degradates to be carbon dioxide and two- and four-carbon aliphatic acids formed by cleavage of both aromatic rings. Carbon dioxide was the major degradate, comprising 40% of the initial radioactivity in the 360 h samples from both labels. The other degradates formed were oxalic acid, maleic acid, glyoxylic acid, and glyoxal. In addition, in the chloronitroaniline-labeled irradiated test solution, 2-chloro-4-nitroaniline was observed and identified after 48 h of irradiation but was not detected thereafter. No other aromatic compounds were isolated or observed in either labeled test system.

Graebing, P. W.; Chib, J. S.; Hubert, T. D.; Gingerich, W. H.

2004-01-01

385

Aqueous chemical wash compositions  

SciTech Connect

This patent describes an aqueous, substantially unfoamed chemical wash composition having properties making it suitable for use as a pre-flush in well cementing operations and/or for removal of drilling mud from a borehole at a temperature of from about 150/sup 0/F to about 270/sup 0/F, the wash a. being predominantly composed of water, b. containing an active surfactant component comprising a combination of (1) from about 0.1 to about 1.5 weight percent (total weight basis) of a water soluble anionic surfactant; (2) from about 0.1 to about 1.5 weight percent (total weight basis) of a nonionic surfactant; and (3) from about 0.05 to about 0.54 weight percent (total weight basis) of at least one water soluble amphoteric surfactant, and c. having dispersed therein a heterogeneous mixture of distinct particles comprising both a first particulate oil soluble resin which is friable and a second particulate oil soluble resin which is pliable and where the size of the friable resin particles ranges from about 0.5 to about 300 microns and the size of the pliable resin particles ranges from about 0.05 to about 30 microns. The amount of the friable-pliable resin mixture is sufficient to impart effective fluid loss control to the chemical wash composition.

Bannister, C.E.

1987-07-21

386

The myelin sheath aqueous layers improve the membrane properties of simulated chronic demyelinating neuropathies.  

PubMed

Recently, patients with chronic demyelinating neuropathies have demonstrated significant abnormalities in their multiple nerve excitability properties measured by a non-invasive threshold tracking technique. In order to expand our studies on the possible mechanisms underlying these abnormalities, which are not yet well understood, we investigate the contributions of the aqueous layers within the myelin sheath on multiple membrane properties of simulated fibre demyelinations. Four degrees of systematic paranodal demyelinations (two mild demyelinations termed PSD1 and PSD2, without/with aqueous layers respectively, and two severe demyelinations termed PSD3 and PSD4, with/without aqueous layers, respectively) are simulated using our previous multi-layered model of human motor nerve fibre. We studied the following parameters of myelinated axonal function: potentials (intracellular action, electrotonic-reflecting the propagating and accommodative fibre processes, respectively) and strength-duration time constants, rheobases, recovery cycles (reflecting the adaptive fibre processes). The results show that each excitability parameter is markedly potentiated when the aqueous layers within their paranodally demyelinated sheaths are taken into account. The effect of the aqueous layers is significantly higher on the propagating processes than on the accommodative and adaptive processes in the fibres. The aqueous layers restore the action potential propagation, which is initially blocked when they are not taken into account. The study provides new and important information on the mechanisms of chronic demyelinating neuropathies, such as chronic inflammatory demyelinating polyneuropathy (CIDP). PMID:21425485

Stephanova, D I; Krustev, S M; Negrev, N; Daskalova, M

2011-03-01

387

Topologically unique heterometallic Cu(II)/Li coordination polymers self-assembled from N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid biobuffer: versatile catalyst precursors for mild hydrocarboxylation of alkanes to carboxylic acids.  

PubMed

The facile aqueous medium reactions of copper(II) nitrate with BES biobuffer [(HOCH(2)CH(2))(2)N(CH(2)CH(2)SO(3)H), hereinafter referred as H(3)bes] in the presence of various benzenecarboxylic acids [benzoic (Hba), 3-hydroxybenzoic (Hhba), and 3,5-dihydroxybenzoic (Hdhba) acid] and lithium hydroxide gave rise to the self-assembly generation of three new heterometallic Cu(II)/Li materials, [Li(H(2)O)(4)][Cu(4)(?(2)-Hbes)(4)(?(2)-ba)]·H(2)O (1) and [Cu(4)(?(3)-Hbes)(4)(L){Li(H(2)O)(2)}](n)·3nH(2)O {L = ?(2)-hba (2) and ?(2)-dhba (3)}. They were isolated as air-stable crystalline solids and fully characterized by infrared (IR) and UV-vis spectroscopy and electrospray ionization (ESI)-MS(±), elemental, thermal, and single-crystal X-ray diffraction analyses. The latter revealed that 1-3 have comparable packing patterns and unit cell parameters, being composed of similar [Cu(4)(?-Hbes)(4)(?-carboxylate)](-) cores and [Li(H(2)O)(4)](+) cations (in 1) or [?-Li(H(2)O)(2)](+) groups (in 2 and 3), which are arranged into discrete 0D aggregates in 1 or infinite 3D noninterpenetrating metal-organic networks in 2 and 3. The topological analysis of the coordination polymers 2 and 3 disclosed the trinodal 3,3,4-connected underlying nets with an unprecedented topology defined by the point symbol of (4.6.8)(4)(4(2).6)(2)(6(2).16(2).18(2)), further simplification of which resulted in the binodal 4,4-connected nets with the pts (PtS) topology. Apart from representing very rare examples of coordination compounds derived from H(3)bes, 1-3 feature solubility in water and were applied as efficient and versatile catalyst precursors for the mild (60 °C) single-pot hydrocarboxylation, by CO and H(2)O, of various gaseous, linear, and cyclic C(n) (n = 2-9) alkanes into the corresponding C(n+1) carboxylic acids, in H(2)O/MeCN medium under homogeneous conditions and in the presence of potassium peroxodisulfate. Total yields (based on alkane) of carboxylic acids up to 78% were achieved, which are remarkable in the field of alkane functionalization under mild conditions, especially for a C-C bond formation reaction in aqueous acid-solvent-free medium. PMID:22482365

Kirillova, Marina V; Kirillov, Alexander M; Martins, André N C; Graiff, Claudia; Tiripicchio, Antonio; Pombeiro, Armando J L

2012-05-01

388

Dissolution of K-feldspar at CO2-saturated conditions  

NASA Astrophysics Data System (ADS)

Underground storage of carbon dioxide on a very large scale is widely considered to be an essential part of any strategy to reduce greenhouse gas emissions to the atmosphere. Aquifers in deep sedimentary basins have been identified as suitable targets for geological carbon dioxide storage, especially aquifers located in sandstone host rock. This has led to renewed interest in studying the interaction between sandstone minerals and aqueous fluids, as there is a paucity of data for CO2-containing systems at relevant conditions. In an attempt to improve data coverage for important silicate minerals, we have measured the dissolution kinetics of K-feldspar in CO2-saturated fluids over a range of temperatures. K-feldspar fragments were hand-picked from a larger sample, crushed to a narrow size range and cleaned. The grains were reacted with water in batch-type reactors at temperatures from 20°C to 200°C and pressures up to 200 bar, and the dissolution was followed by periodic withdrawal of aliquots of solution. The mineral grains were allowed to react with pure water for a number of weeks before injection of CO2 into the system. Excess CO2 was provided to ensure CO2 saturation in the experimental systems. While the reaction time before injection was not long enough to attain complete equilibrium, it did considerably lower the degree of undersaturation with respect to K-feldspar and helped highlight the effect of CO2 injection into a rock-equilibrated aqueous fluid. At all temperatures studied, injection of CO2 resulted in a rapid increase in the soluble concentrations of K and Si (and also Na from a plagioclase component). The dissolution then reached apparent steady state conditions after a few days, with observed dissolution rates in the range of 1E-9 to 1E-12 mol/m2/s over the temperature range studied. The CO2-saturated solutions maintained mildly acidic conditions throughout the experiments and the observed rates therefore fall roughly between rates measured in strong acids and rates measured in unbuffered aqueous solution. However, our rates are slightly slower than those predicted based solely on pH, a fact that we preliminary attribute to our choice to pre-react the mineral and fluid before the CO2 injection. The exact cause of this effect is still under investigation.

Rosenqvist, Jörgen; Kilpatrick, Andrew D.; Yardley, Bruce W. D.; Rochelle, Christopher A.

2014-05-01

389

Acute urinary retention in a 23-year-old woman with mild encephalopathy with a reversible splenial lesion: a case report  

PubMed Central

Introduction Patients with clinically mild encephalitis/encephalopathy with a reversible splenial lesion present with relatively mild central nervous system disturbances. Although the exact etiology of the condition remains poorly understood, it is thought to be associated with infective agents. We present a case of a patient with mild encephalitis/encephalopathy with a reversible splenial lesion, who had the unusual feature of acute urinary retention. Case presentation A 23-year-old Japanese woman developed mild confusion, gait ataxia, and urinary retention seven days after onset of fever and headache. Magnetic resonance imaging demonstrated T2 prolongation in the splenium of the corpus callosum and bilateral cerebral white matter. These magnetic resonance imaging abnormalities disappeared two weeks later, and all of the symptoms resolved completely within four weeks. Except for the presence of acute urinary retention (due to underactive detrusor without hyper-reflexia), the clinical and radiologic features of our patient were consistent with those of previously reported patients with mild encephalitis/encephalopathy with a reversible splenial lesion. To the best of our knowledge, this is the first report of acute urinary retention recognized in a patient with mild encephalitis/encephalopathy with a reversible splenial lesion. Conclusion Our findings suggest that mild encephalitis/encephalopathy with a reversible splenial lesion can be associated with impaired bladder function and indicate that acute urinary retention in this benign disorder should be treated immediately to avoid bladder injury.

2011-01-01

390

Study of Mild Traumatic Brain Injuries Using Experiments and Finite Element Modeling  

PubMed Central

The objective of the study was to better understand the biomechanics of mild traumatic brain injuries (TBI) using a hybrid approach: experiments and computational modeling. A three-dimensional finite element model of the rat skull and brain was used to understand the anatomical region-dependent stress response under mild TBI conditions. Anesthetized rats were exposed to varying coronal plane angular acceleration pulses without direct head contact. Experimental outcomes included unconscious time and histological evidence of brain pathology using GFAP and MAP2. The finite element model was exercised using the five experimental and four supplemental pulses to simulate nine independent combinations of peak acceleration and pulse duration (290 to 542 krad/s2 and 1 to 3 ms). Stress response metrics were correlated to histological and behavioral (e.g., loss of consciousness) evidence of injury in rats subjected to pure coronal plane angular acceleration of the head. Injury severity was modulated by independently controlling peak magnitude and duration of the angular acceleration. While peak Von Mises stresses correlated well with changes in injury severity associated with peak angular acceleration, this metric did not demonstrate sensitivity to changes in acceleration duration. However, an integrated stress-time metric was able to predict changes in injury severity associated with increasing angular acceleration magnitude and duration in both the hippocampal and parietal cortex anatomical regions. Results of this unique hybrid analysis indicate that the combined stress-time variable may be more suited to explain variation of mild TBI severity, rather than pure peak metrics.

Lamy, Michael; Baumgartner, Daniel; Willinger, Remy; Yoganandan, Narayan; Stemper, Brian D.

2011-01-01

391

MR Spectroscopy for Assessment of Memantine Treatment in Mild to Moderate Alzheimer Dementia  

PubMed Central

Objectives Magnetic Resonance Spectroscopy (MRS) may provide a precise and reliable assessment of the extent and severity of neural tissue loss caused by various diseases. In particular, the N-Acetyl Aspartate (NAA) and Creatine (Cr) ratio has been found to be an indicator of the degree of neuronal loss in Alzheimer’s disease (AD). Memantine is thought to benefit the AD brain by stabilizing the NMDA receptors on neurons in turn reducing excitotoxicity. Despite its effectiveness in treating moderate to severe AD, memantine has not had similar success in the treatment of mildly demented AD patients. The objective of this study was to test whether memantine would slow or prevent the loss of neurons in mild to moderate AD patients. Methods A double-blind placebo-controlled study was designed to measure the effect of a year-long course of memantine in patients with a probable AD diagnosis with mild to moderate dementia. The primary outcome measure was stipulated to be change in MRS NAA/Cr ratio in inferior parietal cortex in memantine relative to the placebo treatment condition. The secondary outcome measures were changes in cognitive and function scale scores. Results This pilot study failed to demonstrate a benefit of memantine on the primary outcome measure, the inferior parietal NAA/Cr ratio, or the secondary outcome measures. Conclusions More studies are needed to determine the effect of memantine on regions of the brain significantly affected by AD pathology.

Ashford, J.W.; Adamson, M.; Beale, T.; La, D.; Hernandez, B.; Noda, A.; Rosen, A.; O'Hara, R.; Fairchild, J. K.; Spielman, D.; Yesavage, J.A.

2013-01-01

392

Real-time PCR: Benefits for Detection of Mild and Asymptomatic Giardia Infections  

PubMed Central

The majority of Giardia infections are transmitted by the fecal-oral route and cause giardiasis. Children who live in crowded conditions or low socio-economic areas are the risk group for Giardia infection. Interestingly, most of them are asymptomatic or only mildly infected and can shed the Giardia cysts in the environment. Thus, the diagnosis of Giardia infection in asymptomatic or mild infection plays an important role in achieving control of Giardia duodenalis transmission. The objective of this study was to examine parasitic infections using microscopy and to develop a real-time PCR method for detection of Giardia infection in the stool samples of children living on the Thai-Myanmar border. Both species-specific primers and fluorescent labeled G. duodenalis probe were designed using small-subunit ribosomal RNA (ssrRNA). The results showed that 10 (7.69%) and 40 (30.77%) of 130 stool samples were positive for G. duodenalis by microscopy and real-time PCR respectively. Only 3 out of 9 liquid stools revealed G. duodenalis positive using microscopy, but all of them were G. duodenalis-positive using real-time PCR. The detection limit of real-time PCR for G. duodenalis was 0.1 pg/25 µl reaction. It can detect both mild and asymptomatic Giardia infections in children living on the Thai-Myanmar border.

Prasertbun, Rapeepun; Sukthana, Yaowalark; Popruk, Supaluk

2012-01-01

393

Experimental study of the effect of gas nature on plasma arc cutting of mild steel  

NASA Astrophysics Data System (ADS)

This paper is devoted to the experimental investigation of arc cutting of mild steel using plasmas generated in gas and liquid media. Due to different chemical compositions, the examined media have different thermophysical properties, which affect the properties of the generated plasma and cutting performance. The experiments are performed on 15 mm mild steel plates using commercial equipment at 60 A to approach real operation conditions in application areas. The studied gases are chosen according to recommendations of the world's leading manufacturers of arc cutting equipment for mild steel. Specific differences between plasma gases are discussed from the point of view of properties of the gas and the generated plasma, amount of removed material, kerf shape and overall energy balance of the cutting process. The paper describes the role of exothermic reaction of iron oxidation for oxygen cutting and explains its neglect for liquid cutting. This paper explains the potential of facilitating the cutting process by modification of the plasma gas chemical composition and flow rate.

Kavka, T.; Mašláni, A.; Hrabovský, M.; K?enek, P.; Stehrer, T.; Pauser, H.

2013-06-01

394

ENCOAL Mild Coal Gasification Demonstration Project. Annual report, October 1993--September 1994  

SciTech Connect

ENCOAL Corporation, a wholly-owned subsidiary of SMC Mining Company (formerly Shell Mining Company, now owned by Zeigler Coal Holding Company), has completed the construction and start-up of a mild gasification demonstration plant at Triton Coal Company`s Buckskin Mine near Gillette, Wyoming. The process, using Liquids From Coal (LFC) technology developed by SMC and SGI International, utilizes low-sulfur Powder River Basin coal to produce two new fuels, Process Derived Fuel (PDF) and Coal Derived Liquids (CDL). The LFC technology uses a mild pyrolysis or mild gasification process which involves heating the coal under carefully controlled conditions. The process causes chemical changes in the feed coal in contrast to conventional drying, which leads only to physical changes. Wet subbituminous coal contains considerable water, and conventional drying processes physically remove some of this moisture, causing the heating value to increase. The deeper the coal is physically dried, the higher the heating value and the more the pore structure permanently collapses, preventing resorption of moisture. However, deeply dried Powder River Basin coals exhibit significant stability problems when dried by conventional thermal processes. The LFC process overcomes these stability problems by thermally altering the solid to create PDF and CDL. Several of the major objectives of the ENCOAL Project have now been achieved. The LFC Technology has been essentially demonstrated. Significant quantities of specification CDL have been produced from Buckskin coal. Plant operation in a production mode with respectable availability (approaching 90%) has been demonstrated.

NONE

1995-03-01

395

Mechanical Agitation For Aqueous Cleaning  

NASA Technical Reports Server (NTRS)

Cleaning basket placed in aqueous cleaning solution mechanically agitated by air spring. Compressed air at oscillating pressure supplied to air spring to produce repeated vertical motion of cleaning basket.

Morgan, Gene E.; Hosking, Timothy J.

1995-01-01

396

Microbial treatment of aqueous wastes.  

National Technical Information Service (NTIS)

Aqueous waste effluents from nuclear fuel processing operations may contain trace quantities of heavy metals such as uranium. Conventional treatment of waste waters may be ineffective or expensive when uranium concentrations in the waste water must be red...

K. S. Lee K. J. Chun K. C. Kim Y. H. Choi I. G. Kim

1991-01-01

397

CAPSULE REPORT: AQUEOUS MERCURY TREATMENT  

EPA Science Inventory

This report describes established technologies and identifies evolving methods for treating aqueous mercury. The information provided encompasses full-, pilot- and bench-scale treatment results as presented in the technical literature. The report describes alternative technologi...

398

Freezing of Aqueous Polyvinylpyrrolidone Solutions.  

National Technical Information Service (NTIS)

The freezing of aqueous polyvinylpyrrolidone solutions was studied by means of differential thermal analysis, dilatometry and calorimetry. A differential thermal analysis apparatus for use at low temperatures was constructed. A fast method for the determi...

H. H. G. Jellinek S. Y. Fok

1967-01-01

399

NonAqueous Battery Systems  

Microsoft Academic Search

Lithium and sodium are light and highly electronegative elements which form the basis of anodes for high-energy-density battery systems. Their high chemical reactivity requires the use of ionic conductors based on non-aqueous solvents, polymers, solid electrolytes or fused salts. An associated range of cathode materials enables cells to be fabricated with open-circuit voltages from 1.5 to 4.0 V. Practical non-aqueous

Colin A. Vincent

1996-01-01

400

Activity restriction in mild COPD: a challenging clinical problem  

PubMed Central

Dyspnea, exercise intolerance, and activity restriction are already apparent in mild chronic obstructive pulmonary disease (COPD). However, patients may not seek medical help until their symptoms become troublesome and persistent and significant respiratory impairment is already present; as a consequence, further sustained physical inactivity may contribute to disease progression. Ventilatory and gas exchange impairment, cardiac dysfunction, and skeletal muscle dysfunction are present to a variable degree in patients with mild COPD, and collectively may contribute to exercise intolerance. As such, there is increasing interest in evaluating exercise tolerance and physical activity in symptomatic patients with COPD who have mild airway obstruction, as defined by spirometry. Simple questionnaires, eg, the modified British Medical Research Council dyspnea scale and the COPD Assessment Test, or exercise tests, eg, the 6-minute or incremental and endurance exercise tests can be used to assess exercise performance and functional status. Pedometers and accelerometers are used to evaluate physical activity, and endurance tests (cycle or treadmill) using constant work rate protocols are used to assess the effects of interventions such as pulmonary rehabilitation. In addition, alternative outcome measurements, such as tests of small airway dysfunction and laboratory-based exercise tests, are used to measure the extent of physiological impairment in individuals with persistent dyspnea. This review describes the mechanisms of exercise limitation in patients with mild COPD and the interventions that can potentially improve exercise tolerance. Also discussed are the benefits of pulmonary rehabilitation and the potential role of pharmacologic treatment in symptomatic patients with mild COPD.

O'Donnell, Denis E; Gebke, Kevin B

2014-01-01

401

Reassurance seeking and depression in adults with mild intellectual disability  

PubMed Central

Background Adults with intellectual disability (ID) experience a high prevalence of depression. Yet, little research has investigated interpersonal processes related to depression in this population. In the general population, depressed persons behave in ways that elicit negative and rejecting reactions from others. In particular, excessive reassurance seeking, defined as excessively and persistently seeking assurance from others that one is lovable and worthy, indirectly contributes to depressive symptoms through evoking negative and rejecting social interactions. We examined the relation between excessive reassurance seeking, negative and rejecting social interactions and depression in adults with mild ID. Method Eighty-seven adults with mild ID and staff completed the Glasgow Depression Scale for people with a Learning Disorder and the Reassurance-Seeking Scale. In addition, adults with mild ID reported on their experience of negative social interactions, and staff rated their relative preference to interact with the adult with mild ID. A meditational model of the indirect effect of excessive reassurance seeking on depressive symptoms via negative and rejecting social interactions was tested. Results Excessive reassurance seeking was positively related to depressive symptoms. Negative and rejecting interactions partially mediated the relation between excessive reassurance seeking and depressive symptoms. Conclusions Findings identify an important interpersonal process in depression. Efforts to educate staff and adults with mild ID about excessive reassurance seeking and ways to alter it may be useful in treating depression.

Hartley, S. L.; Lickel, A. Hayes; MacLean, W. E.

2010-01-01

402

REVERSAL OF DIFFERENTIAL GSR CONDITIONING BY INSTRUCTIONS  

Microsoft Academic Search

SS WERE 15 15-17 YR. OLD HIGH SCHOOL STUDENTS. GSR WAS CONDITIONED TO A BLUE LIGHT (CS+) USING MILD SHOCK AS UCS AND A 50% REINFORCEMENT SCHEDULE, WHILE A YELLOW LIGHT (CS-) WAS PRESENTED AN EQUAL NUMBER OF TIMES WITHOUT REINFORCEMENT. AFTER CONDITIONING WAS ESTABLISHED, INSTRUCTIONS DESIGNED TO REVERSE THE SIGNIFICANCE OF CS+ AND CS- WERE GIVEN, FOLLOWED BY A

GLENN D. WILSON

1968-01-01

403

Photochemistry of aqueous pyruvic acid  

PubMed Central

The study of organic chemistry in atmospheric aerosols and cloud formation is of interest in predictions of air quality and climate change. It is now known that aqueous phase chemistry is important in the formation of secondary organic aerosols. Here, the photoreactivity of pyruvic acid (PA; CH3COCOOH) is investigated in aqueous environments characteristic of atmospheric aerosols. PA is currently used as a proxy for ?-dicarbonyls in atmospheric models and is abundant in both the gas phase and the aqueous phase (atmospheric aerosols, fog, and clouds) in the atmosphere. The photoreactivity of PA in these phases, however, is very different, thus prompting the need for a mechanistic understanding of its reactivity in different environments. Although the decarboxylation of aqueous phase PA through UV excitation has been studied for many years, its mechanism and products remain controversial. In this work, photolysis of aqueous PA is shown to produce acetoin (CH3CHOHCOCH3), lactic acid (CH3CHOHCOOH), acetic acid (CH3COOH), and oligomers, illustrating the progression from a three-carbon molecule to four-carbon and even six-carbon molecules through direct photolysis. These products are detected using vibrational and electronic spectroscopy, NMR, and MS, and a reaction mechanism is presented accounting for all products detected. The relevance of sunlight-initiated PA chemistry in aqueous environments is then discussed in the context of processes occurring on atmospheric aerosols.

Griffith, Elizabeth C.; Carpenter, Barry K.; Shoemaker, Richard K.; Vaida, Veronica

2013-01-01

404

Treatment of aqueous and simulated wastewater of Luganil blue N dye – a new electrochemical approach  

Microsoft Academic Search

Treatment of aqueous solution containing Luganil blue N (LBN) azo dye was performed by an electrochemical method under galvanostatic conditions using an undivided cell with platinum electrodes as working and auxiliary electrodes and standard calomel as the reference electrode. The aqueous solution of NaCl was used as the supporting electrolyte. Preliminary voltammetric studies were performed to establish the mode of

Sarala Puttappa; Venkatesha Thimmappa Venkatarangaiah

2011-01-01

405

Fe 0-based trimetallic systems for the removal of aqueous diclofenac: Mechanism and kinetics  

Microsoft Academic Search

The performance of amended micrometric iron particles (Fe0) in trimetallic systems for the removal of aqueous diclofenac (DF) was investigated. Tested additive metals were Pd, Cu and Ni. Trimetallic systems were shown superior to Fe0 for aqueous DF removal both under oxic and anoxic conditions. The extent of DF removal varied with (i) the combination of the additives, (ii) the

Antoine Ghauch; Hala Abou Assi; Habib Baydoun; Al Muthanna Tuqan; Alice Bejjani

2011-01-01

406

Study on Characteristics of Cr(III) Removal by Fly Ash in Aqueous Solution  

Microsoft Academic Search

The leaching characteristics of harmful elements, mainly heavy metals, from fly ash in aqueous solution were analyzed, and fly ash was used as adsorbent to remove Cr(?) in aqueous solution, affecting factors were studied to optimize operation conditions. Desorption effect was checked as well. The results showed that the lixivium of fly ash was alkaline, 7 kinds of metals with

Chunhui Fan; Hongrui Ma; Nan Dang

2011-01-01

407

Oxidation of alkylarenes to the corresponding acids using aqueous potassium permanganate by hydrodynamic cavitation  

Microsoft Academic Search

Oxidation of toluene using aqueous potassium permanganate was studied under heterogeneous condition in the presence of hydrodynamic cavitation and compared with the results of the reaction under acoustic cavitation. Various parameters, such as quantity of potassium permanganate, toluene to aqueous phase ratio, reaction time and cavitation parameters such as orifice plate, and pump discharge pressure were optimized. The reaction was

G. V Ambulgekar; S. D Samant; A. B Pandit

2004-01-01

408

ASSESSMENT OF LIQUID EMULSION MEMBRANE FOR CLEAN UP OF AQUEOUS WASTE EFFLUENTS FROM HAZARDOUS ELEMENTS  

SciTech Connect

Four liquid emulsion membrane (LEM) systems are given to remove different hazardous elements such as uranium, thorium, cobalt, copper, lead, and cadmium from different aqueous waste effluents. The optimum conditions for use of these systems are deduced. The potentiality of LEM for removal of hazardous pollutants from aqueous waste solutions is given.

El-Reefy, Sohair A.; Selim, Y.T.; Hassan, M.A.; Aly, H.F.

2003-02-27

409

Adsorptive removal of phthalate ester (Diethyl phthalate) from aqueous phase by activated carbon: A kinetic study  

Microsoft Academic Search

Adsorptive studies were carried out on Di-ethyl phthalate (DEP) removal from aqueous phase onto activated carbon. Batch sorption studies were performed and the results revealed that activated carbon demonstrated ability to adsorb DEP. Influence of varying experimental conditions such as DEP concentration, pH of aqueous solution, and dosage of adsorbent were investigated on the adsorption process. Sorption interaction of DEP

S. Venkata Mohan; S. Shailaja; M. Rama Krishna; P. N. Sarma

2007-01-01

410

Evaluation of the analgesic properties of the Datura metel seeds aqueous extract  

Microsoft Academic Search

This work was carried out to investigate the analgesic activity of dried seed of Datura metel Linn. A concentrated aqueous extract was obtained, mimicking conditions used in traditional treatment setting, which includes dissolving the extract in water. As in this part of the world, experiments were carried out with the aqueous extract for its peripheral and central antinociceptive potentials on

N. N. Wannang; H. C. Ndukwe; C. Nnabuife

411

Degradation Mechanism of 2,4-Dinitrotoluene in Aqueous Solution (Photooxidation Studies).  

National Technical Information Service (NTIS)

The synergistic effect of hydrogen peroxide (H2O2) and UV radiation from a medium-pressure mercury vapor lamp on the decomposition of 2,4-dinitrotoluene (DNT) in aqueous solution was studied. The most effective conditions for degradation of aqueous DNT so...

P. C. Ho

1984-01-01

412

Could language deficits really differentiate Mild Cognitive Impairment (MCI) from mild Alzheimer's disease?  

PubMed

Naming abilities seem to be affected in Alzheimer's disease (AD) patients, though MCI individuals tend to exhibit greater impairments in category fluency. In this study we: (1) detect language deficits of amnestic MCIs (aMCIs) and mild AD (mAD) participants and present their language performance (the Boston Diagnostic Aphasia Examination - BDAE scores) according to educational level, (2) study the diagnostic value of language deficits according to the cognitive state of the participants. One hundred nineteen participants, 38 normal controls (NC), 28 aMCIs and 53 mADs, were recruited randomly as outpatients of 2 clinical departments and administered clinical, neuropsychological and neuroimaging assessment. Language abilities were assessed by the adapted Greek edition of the BDAE (2nd edition). Our results indicate that verbal fluency, auditory, reading comprehension and narrative ability are the main language abilities to be affected in mADs, although they are almost intact in NCs and less vulnerable in aMCIs. Narrative ability seems to be significantly impaired in mADs but not so in aMCIs. Six language subtests of the BDAE assess safely the above deficits. This brief version of the BDAE discriminated mADs from the other 2 groups 92.5% of the time, NCs 86.8% and aMCI 67.9% of the time in order to save time and to be accurate in clinical practice. PMID:23628238

Tsantali, E; Economidis, D; Tsolaki, M

2013-01-01

413

THE MECHANISM OF AQUEOUS HUMOR FORMATION INFERRED FROM CHEMICAL STUDIES ON BLOOD-AQUEOUS HUMOR DYNAMICS  

PubMed Central

The importance of considering the effect of a possible flow out of the anterior chamber before inferring any mechanism of aqueous humor formation from the relative concentration of a substance in the aqueous humor and plasma under equilibrium conditions has been stressed. Several processes to account for the chemical equilibria between aqueous humor and blood based on the ultrafiltration and secretion hypotheses with a possible simultaneous loss of aqueous humor by flow have been outlined. On the basis of these processes, equations were formulated which would relate the rates of transfer into and out of the anterior chamber to the ratio of concentration of a substance in the aqueous to that in the blood at various intervals after its introduction into the blood. The explanation of equilibrium ratios above and below one for aqueous constituents is made apparent from the mathematical formulations. For each substance tested a determination was made of the best fit when the concentration in the aqueous humor is plotted against time. This fit was obtained by plotting the rate of transfer in against the rate of transfer out of the anterior chamber for all of the experimentally found concentration ratios on the basis of both the ultrafiltration and secretory hypotheses. Two sets of values were obtained from these calculations, one set for each hypothesis. The substantial agreement of all the experimental data with an assumed rate of leakage out of the anterior chamber of approximately 4 c. mm. per minute was shown to be compatible only with the idea that all the monovalent electrolytes tested entered the anterior chamber as a result of secretory process. It could not be decided from these chemical studies whether the non-electrolytes and the one multivalent electrolyte tested enter the anterior chamber by ultrafiltration or secretion. Experimental findings from other sources were cited which would suggest that non-electrolytes enter the anterior chamber as a result of ultrafiltration. The implications of the mechanism outlined in the paper with respect to intraocular pressure have been discussed. Supplementary evidence from the literature has been given in support of the conclusions presented here.

Kinsey, V. Everett; Grant, W. Morton

1942-01-01

414

Fenton chemistry at aqueous interfaces  

PubMed Central

In a fundamental process throughout nature, reduced iron unleashes the oxidative power of hydrogen peroxide into reactive intermediates. However, notwithstanding much work, the mechanism by which Fe2+ catalyzes H2O2 oxidations and the identity of the participating intermediates remain controversial. Here we report the prompt formation of O=FeIVCl3? and chloride-bridged di-iron O=FeIV·Cl·FeIICl4? and O=FeIV·Cl·FeIIICl5? ferryl species, in addition to FeIIICl4?, on the surface of aqueous FeCl2 microjets exposed to gaseous H2O2 or O3 beams for <50 ?s. The unambiguous identification of such species in situ via online electrospray mass spectrometry let us investigate their individual dependences on Fe2+, H2O2, O3, and H+ concentrations, and their responses to tert-butanol (an ·OH scavenger) and DMSO (an O-atom acceptor) cosolutes. We found that (i) mass spectra are not affected by excess tert-butanol, i.e., the detected species are primary products whose formation does not involve ·OH radicals, and (ii) the di-iron ferryls, but not O=FeIVCl3?, can be fully quenched by DMSO under present conditions. We infer that interfacial Fe(H2O)n2+ ions react with H2O2 and O3 >103 times faster than Fe(H2O)62+ in bulk water via a process that favors inner-sphere two-electron O-atom over outer-sphere one-electron transfers. The higher reactivity of di-iron ferryls vs. O=FeIVCl3? as O-atom donors implicates the electronic coupling of mixed-valence iron centers in the weakening of the FeIV–O bond in poly-iron ferryl species.

Enami, Shinichi; Sakamoto, Yosuke; Colussi, Agustin J.

2014-01-01

415

Fenton chemistry at aqueous interfaces.  

PubMed

In a fundamental process throughout nature, reduced iron unleashes the oxidative power of hydrogen peroxide into reactive intermediates. However, notwithstanding much work, the mechanism by which Fe(2+) catalyzes H2O2 oxidations and the identity of the participating intermediates remain controversial. Here we report the prompt formation of O=Fe(IV)Cl3(-) and chloride-bridged di-iron O=Fe(IV) · Cl · Fe(II)Cl4(-) and O=Fe(IV) · Cl · Fe(III)Cl5(-) ferryl species, in addition to Fe(III)Cl4(-), on the surface of aqueous FeCl2 microjets exposed to gaseous H2O2 or O3 beams for <50 ?s. The unambiguous identification of such species in situ via online electrospray mass spectrometry let us investigate their individual dependences on Fe(2+), H2O2, O3, and H(+) concentrations, and their responses to tert-butanol (an · OH scavenger) and DMSO (an O-atom acceptor) cosolutes. We found that (i) mass spectra are not affected by excess tert-butanol, i.e., the detected species are primary products whose formation does not involve · OH radicals, and (ii) the di-iron ferryls, but not O=Fe(IV)Cl3(-), can be fully quenched by DMSO under present conditions. We infer that interfacial Fe(H2O)n(2+) ions react with H2O2 and O3 >10(3) times faster than Fe(H2O)6(2+) in bulk water via a process that favors inner-sphere two-electron O-atom over outer-sphere one-electron transfers. The higher reactivity of di-iron ferryls vs. O=Fe(IV)Cl3(-) as O-atom donors implicates the electronic coupling of mixed-valence iron centers in the weakening of the Fe(IV)-O bond in poly-iron ferryl species. PMID:24379389

Enami, Shinichi; Sakamoto, Yosuke; Colussi, Agustín J

2014-01-14

416

Mild Traumatic Brain Injury among the Geriatric Population  

PubMed Central

Mild traumatic brain injury (TBI) is an unfortunately common occurrence in the elderly. With the growing population of older adults in the United States and globally, strategies that reduce the risk of becoming injured need to be developed, and diagnostic tools and treatments that may benefit this group need to be explored. Particular attention needs to be given to polypharmacy, drug interactions, the use of anticoagulants, safety issues in the living environment, elder abuse, and alcohol consumption. Low-mechanism falls should prompt health care providers to consider the possibility of head injury in elderly patients. Early and tailored management of our seniors following a mild TBI can provide them with the best possible quality of life. This review will discuss the current literature on mild TBI in the older adult, address gaps in research, and discuss the implications for future care of the older TBI patient.

Mendes, Matthew E.; Braga, Carolina F.

2013-01-01

417

Johnson - Cook Strength Models for Mild and DP 590 Steels  

SciTech Connect

Automotive steels, Mild and Dual Phase590 (DP590) are characterized in tension at room temperature, using the quasi-static and split Hopkinson bar techniques at various strain rates ranging from {approx}10-3/s to {approx}1800/s. Tension stress-strain data for both the steels are analyzed to determine the Johnson-Cook Strength model constants, J-C strength model constants for mild steel are A=217 MPa, B = 234 MPa, n = 0.643 and C = 0.076 and for DP590 steel are A = 430 MPa, B = 824 MPa, n = 0.510 and C = 0.017. Higher value of strain rate sensitivity constant C for mild steel (0.076) compared to DP 590 (0.017) is also reflected in the stress- strain data at various strain rates.

Vedantam, K.; Brar, N. S. [Mechanical and Aerospace Engineering and Research Institute, University of Dayton, Dayton, OH 45469-0182 (United States); Bajaj, D. [University of Maryland, Baltimore County, Baltimore, MD 21250 (United States); Hill, S. [University of Dayton Research Institute, University of Dayton, OH 45460-0135 (United States)

2006-07-28

418

Polyelectrolyte brushes: a novel stable lubrication system in aqueous conditions.  

PubMed

Surface-initiated controlled radical copolymerizations of 2-dimethylaminoethyl methacrylate (DMAEMA), 2-(methacryloyloxy)ethyl phosphorylcholine (MPC), 2-(methacryloyloxy)ethyltrimethylammonium chloride) (MTAC), and 3-sulfopropyl methacrylate potassium salt (SPMK) were carried out on a silicon wafer and glass ball to prepare polyelectrolyte brushes with excellent water wettability. The frictional coefficient of the polymer brushes was recorded on a ball-on-plate type tribometer by linear reciprocating motion of the brush specimen at a selected velocity of 1.5 x 10(-3) m s-1 under a normal load of 0.49 N applied to the stationary glass ball (d = 10 mm) at 298 K. The poly(DMAEMA-co-MPC) brush partially cross-linked by bis(2-iodoethoxy)ethane maintained a relatively low friction coefficient around 0.13 under humid air (RH > 75%) even after 200 friction cycles. The poly(SPMK) brush revealed an extremely low friction coefficient around 0.01 even after 450 friction cycles. We supposed that the abrasion of the brush was prevented owing to the good affinity of the poly(SPMK) brush for water forming a water lubrication layer, and electrostatic repulsive interactions among the brushes bearing sulfonic acid groups. Furthermore, the poly(SPMK-co-MTAC) brush with a chemically cross-linked structure showed a stable low friction coefficient in water even after 1400 friction cycles under a normal load of 139 MPa, indicating that the cross-linking structure improved the wear resistance of the brush layer. PMID:23285641

Kobayashi, Motoyasu; Terada, Masami; Takahara, Atsushi

2012-01-01

419

Effects of Caprylic Triglyceride on Cognitive Performance and Cerebral Glucose Metabolism in Mild Alzheimer's Disease: A Single-Case Observation  

PubMed Central

Objective: To examine the effect of 109?days of caprylic triglyceride (CT) in a 70-year-old male with mild Alzheimer’s disease (AD). Background: Cerebral metabolism is limited to glucose under most conditions, and diminished cerebral glucose metabolism is a characteristic feature of AD. Another substrate available for cerebral metabolism is ketone bodies. Ketone bodies (KB) are normally derived from fat stores under conditions of low glucose availability as an alternative energy substrate to glucose. KB can also be produced by oral administration of CT. Prior studies suggest that the alternative energy source of CT may improve cognitive function due to mild to moderate AD, by circumventing the diminished glucose metabolism. Method: The effect of CT was analyzed in a single-case of mild AD with cognitive alterations in an open label study. Study outcomes included the Montreal cognitive assessment (MoCA), mini mental state exam (MMSE), and 18-fluorodeoxyglucose (18F) positron emission tomography (FDG PET) scans. Results: After 109?days of CT, MoCA scores changed from a baseline value of 24–28, and MMSE scores changed from 23 to 28. No changes were observed on FDG PET scans. Conclusion: The results suggest that, in a case of mild AD, CT may have affected cognitive function, assessed by means of MMSE and MoCA, although glucose uptake and metabolism remained unchanged.

Farah, Brian Andrew

2013-01-01

420

Persistent Post-Concussive Syndrome: A proposed methodology and literature review to determine the effects, if any, of mild head and other bodily injury.  

PubMed

Following mild head injury, a subgroup of individuals exhibit a constellation of chronic symptoms, a condition Alexander (1995) labeled Persistent Post-Concussive Syndrome (PPCS). He implicated neurological factors in the initial phase of the syndrome but psychological factors in the maintenance of symptoms. However, it is unclear as to whether an initial mild head injury is necessary or sufficient to cause the symptoms of PPCS. We first outline a study design comparing a mild closed-head injury group to both a normal and an other injury control group to answer this question. Next, we review the literature since 1960 to determine the findings of any studies using this design. The results of the literature review indicate that few such studies exist. To date, those that have been done suggest that there is no strong evidence for a specific effect for mild head injury on cognitive functioning. We discuss directions for future research given these findings. PMID:10572282

Satz, P S; Alfano, M S; Light, R F; Morgenstern, H F; Zaucha, K F; Asarnow, R F; Newton, S

1999-10-01

421

REACTION OF ACTIVATED CARBON WITH AQUEOUS CHLORINE AND CHLORINE DIOXIDE  

EPA Science Inventory

The objective of this research was to determine whether aqueous chlorine and chlorine dioxide react with activated carbon, or with compounds adsorbed on activated carbon, to produce compounds that would not form in the absence of activated carbon. The experimental conditions were...

422

Adsorption of cobalt from aqueous solutions onto sepiolite  

Microsoft Academic Search

Adsorption of Co(II) ions from aqueous sepiolite suspensions has been systematically investigated as a function of several variables including activation conditions, solid to liquid ratio, pH and temperature. The results are analyzed to identify the mechanism of cobalt uptake by sepiolite. Both abstraction and real adsorption isotherms were constructed to isolate the precipitation of cobalt from the real adsorption. Also,

M Kara; H Yuzer; E Sabah; M. S Celik

2003-01-01

423

Abrasive wear behavior of cast iron coatings plasma-sprayed at different mild steel substrate temperatures  

NASA Astrophysics Data System (ADS)

Three kinds of cast iron coatings were prepared by atmospheric plasma spraying. During the spraying, the mild steel substrate temperature was controlled to be averagely 50, 180, and 240°C, respectively. Abrasive wear tests were conducted on the coatings under a dry friction condition. It is found that the abrasive wear resistance is enhanced with the substrate temperature increasing. SEM observations show that the wear losses of the coatings during the wear tests mainly result from the spalling of the splats. Furthermore, the improved wear resistance of the coatings mainly owes to the formation of oxides and the enhancement in the mechanical properties with the substrate temperature increasing.

Xing, Ya-zhe; Wei, Qiu-lan; Jiang, Chao-ping; Hao, Jian-min

2012-08-01

424

Mild solutions of second-order differential equations on the line  

NASA Astrophysics Data System (ADS)

A necessary condition for the existence and uniqueness of mild solutions of first- and second-order differential equations on the real line is given. It is known that the first-order problem is related to the operator equation AX [minus sign] XD = [minus sign][delta]0. Here, it is shown how the second-order problem on the real line is connected to the operator equation AX [minus sign] XD2 = [minus sign][delta]0 and also to some other operator equations.

Schweiker, Sibylle

2000-07-01

425

The effect of stress on the magnetization of mild steel at moderate field strengths  

SciTech Connect

Measurements are presented of the magnetization of mild steel, at field strengths between 100 A/m and 1200 A/m, for hysteretic and anhysteretic conditions. Magnetization was parallel or perpendicular to an applied uniaxial stress. The experimental results showed that tension parallel to the field or compression perpendicular to the field had relatively little effect on the flux density, but parallel compression or perpendicular tension reduced the flux density considerably. The theory presented predicts this symmetry, but it cannot account for other features of the measurements.

Langman, R.

1985-07-01

426

Mild and modular surface modification of cellulose via hetero Diels-Alder (HDA) cycloaddition.  

PubMed

A combination of reversible addition-fragmentation chain transfer (RAFT) polymerization and hetero Diels-Alder (HDA) cycloaddition was used to effect, under mild (T ? 20 °C), fast, and modular conditions, the grafting of poly(isobornyl acrylate) (M(n) = 9800 g mol(-1), PDI = 1.19) onto a solid cellulose substrate. The active hydroxyl groups expressed on the cellulose fibers were converted to tosylate leaving groups, which were subsequently substituted by a highly reactive cyclopentadienyl functionality (Cp). By employing the reactive Cp-functionality as a diene, thiocarbonyl thio-capped poly(isobornyl acrylate) synthesized via RAFT polymerization (mediated by benzyl pyridine-2-yldithioformiate (BPDF)) was attached to the surface under ambient conditions by an HDA cycloaddition (reaction time: 15 h). The surface-modified cellulose samples were analyzed in-depth by X-ray photoelectron spectroscopy, scanning electron microscopy, elemental analysis, Fourier transform infrared (FT-IR) spectroscopy as well as Fourier transform infrared microscopy employing a focal plane array detector for imaging purposes. The analytical results provide strong evidence that the reaction of suitable dienophiles with Cp-functional cellulose proceeds under mild reaction conditions (T ? 20 °C) in an efficient fashion. In particular, the visualization of individual modified cellulose fibers via high-resolution FT-IR microscopy corroborates the homogeneous distribution of the polymer film on the cellulose fibers. PMID:21366268

Goldmann, Anja S; Tischer, Thomas; Barner, Leonie; Bruns, Michael; Barner-Kowollik, Christopher

2011-04-11

427

Wechsler Memory Scale-III Faces test performance in patients with mild cognitive impairment and mild Alzheimer's disease  

PubMed Central

Little is known about the sensitivity of the Wechsler Memory Scale–Third Edition (WMS-III) Faces subtest to memory impairment associated with mild cognitive impairment (MCI). In this study, Faces performance was examined in 24 MCI patients, 46 mild Alzheimer’s disease (AD) patients, and 98 elderly controls. We hypothesized that participants with diagnoses of MCI or AD would be impaired relative to controls on Faces. Analyses showed that AD participants performed significantly worse than MCI and intact participants, although there were no significant differences between MCI and intact participants. Data suggest that brain areas specialized for face recognition memory may be less affected by MCI and mild AD than regions specialized for verbal memory.

Seelye, Adriana M.; Howieson, Diane B.; Wild, Katherine V.; Moore, Mindy Milar; Kaye, Jeffrey A.

2009-01-01

428

DEVELOPMENT OF A CO2 SEQUESTRATION MODULE BY INTEGRATING MINERAL ACTIVATION AND AQUEOUS CARBONATION  

SciTech Connect

Mineral carbonation is a promising concept for permanent CO{sub 2} sequestration due to the vast natural abundance of the raw minerals, the permanent storage of CO{sub 2} in solid form as carbonates, and the overall reaction being exothermic. However, the primary drawback to mineral carbonation is the reaction kinetics. To accelerate the reaction, aqueous carbonation processes are preferred, where the minerals are firstly dissolved in solution. In aqueous carbonation, the key step is the dissolution rate of the mineral, where the mineral dissolution reaction is likely to be surface controlled. In order to accelerate the dissolution process, the serpentine can be ground to very fine particle size (<37 {micro}m), but this is a very energy intensive process. Alternatively, magnesium could be chemically extracted in aqueous solution. Phase I showed that chemical surface activation helps to dissolve the magnesium from the serpentine minerals (particle size {approx}100 {micro}m), and furthermore, the carbonation reaction can be conducted under mild conditions (20 C and 650 psig) compared to previous studies that required >185 C, >1850 psig and <37 {micro}m particle size. Phase I also showed that over 70% of the magnesium can be extracted at ambient temperature leaving amorphous SiO{sub 2}