Enantiomeric Mixtures in Natural Product Chemistry: Separation and Absolute Configuration Assignment.

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N L Batista, Andrea; M Dos Santos, Fernando; Batista, João M; Cass, Quezia B

2018-02-23

Chiral natural product molecules are generally assumed to be biosynthesized in an enantiomerically pure or enriched fashion. Nevertheless, a significant amount of racemates or enantiomerically enriched mixtures has been reported from natural sources. This number is estimated to be even larger since the enantiomeric purity of secondary metabolites is rarely checked in the natural product isolation pipeline. This latter fact may have drastic effects on the evaluation of the biological activity of chiral natural products. A second bottleneck is the determination of their absolute configurations. Despite the widespread use of optical rotation and electronic circular dichroism, most of the stereochemical assignments are based on empirical correlations with similar compounds reported in the literature. As an alternative, the combination of vibrational circular dichroism and quantum chemical calculations has emerged as a powerful and reliable tool for both conformational and configurational analysis of natural products, even for those lacking UV-Vis chromophores. In this review, we aim to provide the reader with a critical overview of the occurrence of enantiomeric mixtures of secondary metabolites in nature as well the best practices for their detection, enantioselective separation using liquid chromatography, and determination of absolute configuration by means of vibrational circular dichroism and density functional theory calculations.

Laboratory and field measurements of enantiomeric monoterpene emissions as a function of chemotype, light and temperature

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Song, W.; Staudt, M.; Bourgeois, I.; Williams, J.

2014-03-01

Plants emit significant amounts of monoterpenes into the earth's atmosphere, where they react rapidly to form a multitude of gas phase species and particles. Many monoterpenes exist in mirror-image forms or enantiomers. In this study the enantiomeric monoterpene profile for several representative plants (Quercus ilex L., Rosmarinus officinalis L., and Pinus halepensis Mill.) was investigated as a function of chemotype, light and temperature both in the laboratory and in the field. Analysis of enantiomeric monoterpenes from 19 Quercus ilex individuals from Southern France and Spain revealed four regiospecific chemotypes (genetically fixed emission patterns). In agreement with previous work, only Quercus ilex emissions increased strongly with light. However, for all three plant species no consistent enantiomeric variation was observed as a function of light, and the enantiomeric ratio of α-pinene was found to vary by less than 20% from 100 and 1000 μmol m-2 s-1 PAR (photosynthetically active radiation). The rate of monoterpene emission increased with temperature from all three plant species, but little variation in the enantiomeric distribution of α-pinene was observed with temperature. There was more enantiomeric variability between individuals of the same species than could be induced by either light or temperature. Field measurements of α-pinene enantiomer mixing ratios in the air, taken at a Quercus ilex forest in Southern France, and several other previously reported field enantiomeric ratio diel cycle profiles are compared. All show smoothly varying diel cycles (some positive and some negative) even over changing wind directions. This is surprising in comparison with variations of enantiomeric emission patterns shown by individuals of the same species.

Enantiomeric Distribution of Some Linalool Containing Essential Oils and Their Biological Activities

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K. Hüsnü Can Başer

2010-10-01

Full Text Available The enantiomeric composition of linalool was determined in 42 essential oils using chiral columns. Essential oils were analyzed by multidimentional gas chromatography-mass spectrometry using a non-chiral and chiral FSC columns combination with modified g -cyclodextrine (Lipodex E as the chiral stationary phase without previous isolation of the compound from the mixture. The essential oils of Achillea, Ballota, Calamintha, Micromeria, Hedychium, Tanacetum, Coriandrum, Xanthoxylum, Ocimum, Thymus, Lavandula, Elettaria, Cinnamomum, Salvia, Origanum, Satureja, Nepeta, Stachys were used as source material for enantiomeric separation of linalool. Enantiomeric distribution of linalool showed (--linalool was much more common than the (+-linalool in the essential oils in this study. (-- and (+-linalool enantiomers were evaluated for antimicrobial, antifungal and antimalarial activities. Both enantiomers demonstrated approximately 50% growth inhibition of Botrytis cinerea at 48 hrs.

Amino Acid Enantiomeric Ratios in Biogeochemistry: Complications and Opportunities

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McDonald, G. D.; Sun, H. J.; Tsapin, A. I.

2003-12-01

Amino acid enantiomeric ratios have been used for many years as an indicator of the process of racemization, and thus as a method to determine the age of biological samples such as bones, shells, and teeth. Dating biological samples by this method relies on an accurate knowledge of the environmental temperatures the sample has experienced, and the racemization kinetic parameters in the sample matrix. In some environments, where an independent dating method such as radiocarbon is available, the observed amino acid D/L ratios are found to be either higher or lower than those expected due to racemization alone. The observed D/L ratios in these cases can be clues to biogeochemical processes operating in addition to, or in place of, chemical racemization. In Siberian permafrost (Brinton et al. 2002, Astrobiology 2, 77) we have found D/L ratios lower than expected, which we have interpreted as evidence for low-level D-amino acid metabolism and recycling in microorganisms previously thought to be metabolically dormant. In microbially-colonized Antarctic Dry Valley sandstones (McDonald and Sun 2002, Eos Trans. AGU 83, Fall Meet. Suppl., Abstract B11A-0720) we have found D/L ratios higher than can be accounted for by racemization alone, most likely due to the accumulation of D-amino-acid-containing peptidoglycan material from multiple bacterial generations. D/L profiles in polar ices and in ice-covered lakes (Tsapin et al. 2002, Astrobiology 2, 632) can be used to indicate the sources and histories of water or ice samples. Multiple biological and biogeochemical processes may complicate the interpretation of amino acid enantiomeric excesses in both terrestrial and extraterrestrial samples; however, amino acid racemization remains a useful tool in biogeochemistry and astrobiology. With a good knowledge of the environmental history of samples, amino acid D/L profiles can be used as a window into processes such as molecular repair and biomass turnover that are difficult to

Enantiomerization and stereoselectivity in bioaccumulation of furalaxyl in Tenebrio molitor larvae.

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Yin, Jing; Gao, Yongxin; Zhu, Feilong; Hao, Weiyu; Xu, Qi; Wang, Huili; Guo, Baoyuan

2017-11-01

Furalaxyl is a chiral pesticide and widely used in modern agriculture as racemate mixture. The enantiomerization and enantioselecive bioaccumulation by a single dose of furalaxyl to Tenebrio molitor larvae under laboratory conditions were studied using a high-performance liquid chromatography tandem mass spectroscopy method based on a ChiralPAK IC column. Our results showed that a significant enantiomerization (interconversion between R-enantiomer and S-enantiomer) was observed in Tenebrio molitor larvae under R- or S-furalaxyl exposure. Though the two furalaxyl enantiomers exhibited low-capacity of bioaccumulation in Tenebrio molitor larvae, bioaccumulation of rac-furalaxyl was enantioselective with a preferential accumulation of S-furalaxyl at 10mg/kg dosage exposure. In addition, enantiomerization and enantioselective degradation of the two enantiomers was not observed in wheat bran. These results showed that enantioselectivtiy of furalaxyl enantiomers was an important process combined with degradation, metabolism and enatiomerization in organisms. Copyright © 2017 Elsevier Inc. All rights reserved.

Enantiomeric behaviour of albendazole and fenbendazole sulfoxides in domestic animals: pharmacological implications.

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Capece, Bettencourt P S; Virkel, Guillermo L; Lanusse, Carlos E

2009-09-01

Albendazole and fenbendazole are methylcarbamate benzimidazole anthelmintics extensively used to control gastrointestinal parasites in domestic animals. These parent compounds are metabolised to albendazole sulfoxide and fenbendazole sulfoxide (oxfendazole), respectively. Both sulfoxide derivatives are anthelmintically active and are manufactured for use in animals. They metabolites have an asymmetric centre on their chemical structures and two enantiomeric forms of each sulfoxide have been identified in plasma, tissues of parasite location and within target helminths. Both the flavin-monooxygenase and cytochrome P450 systems are involved in the enantioselective biotransformation of these anthelmintic compounds in ruminant species. A relevant progress on the understanding of the relationship among enantioselective metabolism and systemic availability of each enantiomeric form has been achieved. This article reviews the current knowledge on the pharmacological implications of the enantiomeric behaviour of albendazole sulfoxide and oxfendazole in domestic animals.

Hammond Postulate Mirroring Enables Enantiomeric Enrichment of Phosphorus Compounds via Two Thermodynamically Interconnected Sequential Stereoselective Processes.

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Rajendran, Kamalraj V; Nikitin, Kirill V; Gilheany, Declan G

2015-07-29

The dynamic resolution of tertiary phosphines and phosphine oxides was monitored by NMR spectroscopy. It was found that the stereoselectivity is set during the formation of the diastereomeric alkoxyphosphonium salts (DAPS), such that their initial diastereomeric excess (de) limits the final enantiomeric excess (ee) of any phosphorus products derived from them. However, (31)P NMR monitoring of the spontaneous thermal decomposition of the DAPS shows consistent diastereomeric self-enrichment, indicating a higher rate constant for decomposition of the minor diastereomer. This crucial observation was confirmed by reductive trapping of the unreacted enriched DAPS with lithium tri-sec-butylborohydride (commercially distributed as L-Selectride reagent) at different time intervals after the start of reaction, which gives progressively higher ee of the phosphine product with time. It is proposed that the Hammond postulate operates for both formation and decomposition of DAPS intermediate so that the lower rate of formation and faster subsequent collapse of the minor isomer are thermodynamically linked. This kinetic enhancement of kinetic resolution furnishes up to 97% ee product.

2,2′,3,5′,6-PENTACHLOROBIPHENYL (PCB 95) AND ITS HYDROXYLATED METABOLITES ARE ENANTIOMERICALLY ENRICHED IN FEMALE MICE

Science.gov (United States)

Kania-Korwel, Izabela; Barnhart, Christopher D.; Stamou, Marianna; Truong, Kim M.; El-Komy, Mohammed H.M.E.; Lein, Pamela J.; Veng-Pedersen, Peter; Lehmler, Hans-Joachim

2012-01-01

Epidemiological and laboratory studies link polychlorinated biphenyls and their metabolites to adverse neurodevelopmental outcomes. Several neurotoxic PCB congeners are chiral and undergo enantiomeric enrichment in mammalian species, which may modulate PCB developmental neurotoxicity. This study measures levels and enantiomeric enrichment of PCB 95 and its hydroxylated metabolites (OH-PCBs) in adult female C57Bl/6 mice following subchronic exposure to racemic PCB 95. Tissue levels of PCB 95 and OH-PCBs increased with increasing dose. Dose-dependent enantiomeric enrichment of PCB 95 was observed in brain and other tissues. OH-PCBs also displayed enantiomeric enrichment in blood and liver, but were not detected in adipose and brain. In light of data suggesting enantioselective effects of chiral PCBs on molecular targets linked to PCB developmental neurotoxicity, our observations highlight the importance of accounting for PCB and OH-PCB enantiomeric enrichment in the assessment of PCB developmental neurotoxicity. PMID:22974126

Systematic studies using 2-(1-adamantylethynyl)pyrimidine-5-carbaldehyde as a starting material in Soai's asymmetric autocatalysis.

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Busch, Mark; Schlageter, Martin; Weingand, Daniel; Gehring, Timo

2009-08-17

Herein, we present a new substrate for the Soai reaction, which has an adamantylethynyl residue (1 g) and exhibits asymmetric autocatalysis, yielding products with enantiomeric excesses above 99%. For the first time, all reactions were performed on a parallel synthesizer system to ensure identical reaction conditions. A detailed systematic study of reaction parameters was performed and we report the highest enhancements of enantiomeric excess reported so far in the Soai reaction in one reaction cycle (7.2-->94.1% ee or 3.1-->92.1% ee). Our results led to a set of reaction parameters that yield reproducible results. Therefore, our new starting material 1 g is suitable for systematic and mechanistic studies on this remarkable reaction. A series of experiments designed to quantify the amplification of enantiomeric excess demonstrated that the reaction can be used in principle as a tool for the detection of low enantiomeric excesses: under definite conditions, an unknown low enantiomeric excess (0.1-7%) was amplified to a detectable one. A back calculation to the original value offers a new method for the determination of small enantiomeric excesses.

Validation of a capillary electrophoresis method for the enantiomeric purity testing of ropivacaine, a new local anaesthetic compound

NARCIS (Netherlands)

Sänger-Van De Griend, C. E.; Gröningsson, K.

A capillary electrophoresis method for the determination of the enantiomeric purity of ropivacaine, a new local anaesthetic compound developed by Astra Pain Control AB, has been validated. The method showed the required limit of quantitation of 0.1%, enantiomeric impurity and proved to be robust.

Synthesis of diastereomerically and enantiomerically pure 2,3-disubstituted tetrahydrofurans using a sulfoxonium ylide.

Science.gov (United States)

Schomaker, Jennifer M; Pulgam, Veera Reddy; Borhan, Babak

2004-10-27

Nucleophilic substitution reactions of 2,3-epoxy alcohols, easily prepared via Sharpless asymmetric epoxidation chemistry, offer access to a wide variety of enantiomerically pure compounds. In this communication, we describe the use of a Payne rearrangement to control regioselectivity in the ring-opening of a series of 2,3-epoxy alcohols with dimethylsulfoxonium methylide to yield diastereomerically and/or enantiomerically pure disubstituted tetrahydrofuran rings. The factors influencing the success and substitution pattern of the THF ring products are discussed, including steric, electronic, and solvent effects.

Synthesis, enantiomeric resolution, F-18 labeling and biodistribution of reboxetine analogs: promising radioligands for imaging the norepinephrine transporter with positron emission tomography.

Science.gov (United States)

Lin, Kuo-Shyan; Ding, Yu-Shin; Kim, Sung-Won; Kil, Kun-Eek

2005-05-01

Racemic and enantiomerically pure ((S,S) and (R,R)) 2-[alpha-(2-(2-[(18)F]fluoroethoxy)phenoxy)benzyl]morpholine ([(18)F]FRB) and its tetradeuterated form [(18)F]FRB-D(4), analogs of the highly selective norepinephrine reuptake inhibitor reboxetine (2-[alpha-(2-ethoxyphenoxy)benzyl]morpholine, RB), have been synthesized for studies of norepinephrine transporter (NET) system with positron emission tomography (PET). The [(18)F]fluorinated precursor, (S,S)/(R,R)-N-tert-butyloxycarbonyl-2-[alpha-(2-hydroxyphenoxy)benzyl]morpholine ((S,S)/(R,R)-N-Boc-desethylRB), was prepared by the N-protection of (S,S)/(R,R)-2-[alpha-(2-hydroxyphenoxy)benzyl]morpholine ((S,S)/(R,R)-desethylRB) with a tert-butyloxycarbonyl (Boc) group followed by enantiomeric resolution with chiral HPLC to provide both (S,S) and (R,R) enantiomers with >99% enantiomeric purity. These compounds were then used for radiosynthesis to prepare enantiomerically pure [(18)F]FRB and [(18)F]FRB-D(4) via the following three-step procedure: (1) formation of 1-bromo-2-[(18)F]fluoroethane ([(18)F]BFE or [(18)F]BFE-D(4)) by nucleophilic displacement of 2-bromoethyl triflate (or D(4) analog) with no-carrier added [(18)F]F(-) in THF; (2) reaction of [(18)F]BFE (or [(18)F]BFE-D(4)) with N-Boc-desethylRB in DMF in the presence of excess base; and (3) deprotection with trifluoroacetic acid. The racemates, (S,S) and (R,R) enantiomers of [(18)F]FRB and [(18)F]FRB-D(4) were obtained in 11-27% (decay corrected to the end of bombardment, EOB) in 120-min synthesis time with a radiochemical purity of >98% and specific activities of 21-48 GBq/micromol (EOB). The results of the whole-body biodistribution studies with (S,S)-[(18)F]FRB-D(4) were similar to those with (S,S)-[(18)F]FRB but showed relatively faster blood clearance and no significant in vivo defluorination. Positron emission tomography studies in baboon brain also showed that (S,S)-[(18)F]FRB-D(4) may be a potentially useful ligand for imaging NET with PET.

Synthesis, enantiomeric resolution, F-18 labeling and biodistribution of reboxetine analogs: promising radioligands for imaging the norepinephrine transporter with positron emission tomography

International Nuclear Information System (INIS)

Lin, K.-S.; Ding, Y.-S.; Kim, Sung-Won; Kil, Kun-Eek

2005-01-01

Racemic and enantiomerically pure ((S,S) and (R,R)) 2-[α-(2-(2-[ 18 F]fluoroethoxy)phenoxy)benzyl]morpholine ([ 18 F]FRB) and its tetradeuterated form [ 18 F]FRB-D 4 , analogs of the highly selective norepinephrine reuptake inhibitor reboxetine (2-[α-(2-ethoxyphenoxy)benzyl]morpholine, RB), have been synthesized for studies of norepinephrine transporter (NET) system with positron emission tomography (PET). The [ 18 F]fluorinated precursor, (S,S)/(R,R)-N-tert-butyloxycarbonyl-2-[α-(2-hydroxyphenoxy)benzyl] morpholine ((S,S)/(R,R)-N-Boc-desethylRB), was prepared by the N-protection of (S,S)/(R,R)-2-[α-(2-hydroxyphenoxy)benzyl]morpholine ((S,S)/(R,R)-desethylRB) with a tert-butyloxycarbonyl (Boc) group followed by enantiomeric resolution with chiral HPLC to provide both (S,S) and (R,R) enantiomers with >99% enantiomeric purity. These compounds were then used for radiosynthesis to prepare enantiomerically pure [ 18 F]FRB and [ 18 F]FRB-D 4 via the following three-step procedure: (1) formation of 1-bromo-2-[ 18 F]fluoroethane ([ 18 F]BFE or [ 18 F]BFE-D 4 ) by nucleophilic displacement of 2-bromoethyl triflate (or D 4 analog) with no-carrier added [ 18 F]F - in THF; (2) reaction of [ 18 F]BFE (or [ 18 F]BFE-D 4 ) with N-Boc-desethylRB in DMF in the presence of excess base; and (3) deprotection with trifluoroacetic acid. The racemates, (S,S) and (R,R) enantiomers of [ 18 F]FRB and [ 18 F]FRB-D 4 were obtained in 11-27% (decay corrected to the end of bombardment, EOB) in 120-min synthesis time with a radiochemical purity of >98% and specific activities of 21-48 GBq/μmol (EOB). The results of the whole-body biodistribution studies with (S,S)-[ 18 F]FRB-D 4 were similar to those with (S,S)-[ 18 F]FRB but showed relatively faster blood clearance and no significant in vivo defluorination. Positron emission tomography studies in baboon brain also showed that (S,S)-[ 18 F]FRB-D 4 may be a potentially useful ligand for imaging NET with PET

Synthesis and biological evaluation of enantiomerically pure cyclopropyl analogues of combretastatin A4.

Science.gov (United States)

Ty, Nancy; Pontikis, Renée; Chabot, Guy G; Devillers, Emmanuelle; Quentin, Lionel; Bourg, Stéphane; Florent, Jean-Claude

2013-03-01

To evaluate the influence of stereochemistry on biological activities of cis-cyclopropyl combretastatin A4 (CA4) analogues, we have prepared several cyclopropyl compounds in their pure enantiomeric forms. The key reactions in our synthesis are the cyclopropanation of a (Z)-alkenylboron compound bearing a chiral auxiliary, and the cross-coupling of both enantiomeric cyclopropyl trifluoroborate salts with aryl and olefinic halides. Three pairs of cis-cyclopropyl CA4 analogues were evaluated for their potential antivascular activities. The diarylcyclopropyl compounds with SR-configuration (-)-1b, (-)-2b and the cyclopropylvinyl enantiomer (+)-3a with RR-configuration were the most potent tubulin polymerization inhibitors. A correlation was noted between anti-tubulin activity and rounding up activity of endothelial cells. The cytotoxic activity on B16 melanoma cells was in the submicromolar range for most compounds, but unlike the anti-tubulin activity, there was no difference in cytotoxic activity between racemic and enantiomerically pure forms for the three series of compounds. Molecular docking studies within the colchicine binding site of tubulin were in good agreement with the tubulin polymerization inhibitory data and confirmed the importance of the configuration of the synthesized cis-cyclopropyl CA4 analogues for potential antivascular activities. Copyright © 2013. Published by Elsevier Ltd.

Use of a macrocyclic antibiotic as the chiral selector for enantiomeric separations by TLC

Energy Technology Data Exchange (ETDEWEB)

Armstrong, D.W.; Zhou, Y. (Univ. of Missouri, Rolla, MO (United States). Dept. of Chemistry)

1994-01-01

The macrocyclic antibiotic, vancomycin, was used as a chiral mobile phase additive for the thin layer chromatographic (TLC) resolution of 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) derivatized amino acids, racemic drugs and dansyl-amino acids. Excellent separations were achieved for most of these compounds in the reversed phase mode. Both the nature of the stationary phase and the composition of the mobile phase strongly influenced enantiomeric resolution. The best results were obtained using diphenyl stationary phases. Acetonitrile was the organic modifier that produced the most effective separations with the shortest development times. It is highly likely that macrocyclic antibiotics will play a major role in future enantiomeric separations.

Synthesis, enantiomeric resolution, F-18 labeling and biodistribution of reboxetine analogs: promising radioligands for imaging the norepinephrine transporter with positron emission tomography

Energy Technology Data Exchange (ETDEWEB)

Lin, K.-S. [Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Ding, Y.-S. [Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)]. E-mail: ding@bnl.gov; Kim, Sung-Won [Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Kil, Kun-Eek [Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)

2005-05-01

Racemic and enantiomerically pure ((S,S) and (R,R)) 2-[{alpha}-(2-(2-[{sup 18}F]fluoroethoxy)phenoxy)benzyl]morpholine ([{sup 18}F]FRB) and its tetradeuterated form [{sup 18}F]FRB-D{sub 4}, analogs of the highly selective norepinephrine reuptake inhibitor reboxetine (2-[{alpha}-(2-ethoxyphenoxy)benzyl]morpholine, RB), have been synthesized for studies of norepinephrine transporter (NET) system with positron emission tomography (PET). The [{sup 18}F]fluorinated precursor, (S,S)/(R,R)-N-tert-butyloxycarbonyl-2-[{alpha}-(2-hydroxyphenoxy)benzyl] morpholine ((S,S)/(R,R)-N-Boc-desethylRB), was prepared by the N-protection of (S,S)/(R,R)-2-[{alpha}-(2-hydroxyphenoxy)benzyl]morpholine ((S,S)/(R,R)-desethylRB) with a tert-butyloxycarbonyl (Boc) group followed by enantiomeric resolution with chiral HPLC to provide both (S,S) and (R,R) enantiomers with >99% enantiomeric purity. These compounds were then used for radiosynthesis to prepare enantiomerically pure [{sup 18}F]FRB and [{sup 18}F]FRB-D{sub 4} via the following three-step procedure: (1) formation of 1-bromo-2-[{sup 18}F]fluoroethane ([{sup 18}F]BFE or [{sup 18}F]BFE-D{sub 4}) by nucleophilic displacement of 2-bromoethyl triflate (or D{sub 4} analog) with no-carrier added [{sup 18}F]F{sup -} in THF; (2) reaction of [{sup 18}F]BFE (or [{sup 18}F]BFE-D{sub 4}) with N-Boc-desethylRB in DMF in the presence of excess base; and (3) deprotection with trifluoroacetic acid. The racemates, (S,S) and (R,R) enantiomers of [{sup 18}F]FRB and [{sup 18}F]FRB-D{sub 4} were obtained in 11-27% (decay corrected to the end of bombardment, EOB) in 120-min synthesis time with a radiochemical purity of >98% and specific activities of 21-48 GBq/{mu}mol (EOB). The results of the whole-body biodistribution studies with (S,S)-[{sup 18}F]FRB-D{sub 4} were similar to those with (S,S)-[{sup 18}F]FRB but showed relatively faster blood clearance and no significant in vivo defluorination. Positron emission tomography studies in baboon brain also

Gas-chromatographic resolution of enantiomeric secondary alcohols. Stereoselective reductive metabolism of ketones in rabbit-liver cytosol.

Science.gov (United States)

Gal, J; DeVito, D; Harper, T W

1981-01-01

Chiral secondary alcohols were treated with (S)-(-)-1-phenylethyl isocyanate. For each racemic alcohol, the resulting diastereomeric urethane derivatives were resolved on flexible fused-silica capillary GLC columns with retention times of 15 min or less. Derivatization of individual enantiomers showed that the urethane derivatives of (R)-(-)-2-octanol, (R)-(+)-1-phenylethyl alcohol, and (S)-(+)-2,2,2-trifluoro-1-phenylethanol are eluted before the corresponding diastereomers. The procedure is simple and rapid, and is suitable for the determination of the enantiomeric composition of chiral alcohols extracted from biological media. A series of aliphatic alcohols, aryl alkyl carbinols, and arylalkyl alkyl carbinols were resolved with the procedure, and the degree of resolution varied from good to excellent. Eight achiral ketones were incubated, individually, with rabbit-liver 90,000 g supernatant fractions, and the enantiomeric composition of the alcohol metabolites was determined with the GLC procedure. The reductions proceeded with high stereoselectivity to give alcohol products of 90% or greater enantiomeric purity. The reduction of 2-octanone and acetophenone gave predominant alcohols of (S)-configuration, in agreement with the Baumann-Prelog rule. The configuration of the predominant alcohols arising in the reduction of the remainder of the ketones could not be firmly established, but the evidence suggests that they are also of the (S)-configuration. Fluorine or methyl substitution in the ortho position of acetophenone produced an increase in the stereoselectivity, and the alcohol produced from ortho-methylacetophenone was enantiomerically greater than 99% pure.

Enantiomeric profiling of chiral illicit drugs in a pan-European study

NARCIS (Netherlands)

Castrignanò, E.; Yang, Z.; Bade, R.; Baz-Lomba, J.A.; Castiglioni, S.; Causanilles, A.; Covaci, A.; Gracia-Lor, E.; Hernández, F.; Kinyua, J.; McCall, A.-K.; van Nuijs, A.L.N.; Ort, C.; Plósz, B.G.; Ramin, P.; Rousis, N.I.; Ryu, Y.; Thomas, K.V.; de Voogt, P.; Zuccato, E.; Kasprzyk-Hordern, B.

2018-01-01

The aim of this paper is to present the first study on spatial and temporal variation in the enantiomeric profile of chiral drugs in eight European cities. Wastewater-based epidemiology (WBE) and enantioselective analysis were combined to evaluate trends in illicit drug use in the context of their

Synthesis of prostanoids; enantiomeric purity of alcohols by a 31P NMR technique

International Nuclear Information System (INIS)

Penning, T.D.

1985-01-01

The enone, 2,2-diemthyl-3aβ, 6aβ-dihydro-4H-cyclopenta-1,3-dioxol-4-one, has been synthesized in six steps from cyclopentadiene, resolved using sulfoximine chemistry, and converted into (-)-prostaglandin E 2 methyl ester in three steps. Introduction of the optically pure omega side-chain using a conjugate addition of a stabilized organocopper reagent, followed by direct alkylation of the enolate with the α side-chain allylic iodide in the presence of hexamethylphosphoramide, afforded a trans, vicinally disubstituted cyclopentanone. Deprotection of the C-15 alcohol, followed by aluminum amalgam reduction of the C-10/oxygen bond, provided (-)-PGE 2 methyl ester in 47% overall yield from the enone. In an extension of previously described work, 2-chloro-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidine 2-sulfide, prepared from l-ephedrine and thiophosphoryl chloride, was used to determine the enantiomeric excess of chiral alcohols in conjunction with 31 P NMR. Chiral primary and secondary alcohols added quantitatively to the phospholidine to give diastereomers which could be analyzed by 31 P NMR and HPLC. A number of other phosphorus heterocycles were also explored as potential chiral derivatizing reagents

Enantiomeric separation of iridium (III) complexes using HPLC chiral stationary phases based on amylose derivatives

International Nuclear Information System (INIS)

Kim, Hee Eun; Seo, Na Hyeon; Hyun, Myung Ho

2016-01-01

Cyclometalated iridium (III) complexes formed with three identical cyclometalating (C-N) ligands (homoleptic) or formed with two cyclometalating (C-N) ligands and one ancillary (LX) ligand (heteroleptic) have been known as highly phosphorescent materials and, thus, they have been utilized as efficient phosphorescent dopants in organic light emitting diodes (OLEDs) 1–3 or as effective phosphorescent chemosensors. 4–7 Cylometalated iridium (III) complexes are chiral compounds consisting of lambda (Λ, left-handed) and delta (Δ, right-handed) isomers. Racemic cyclometa- lated iridium (III) complexes emit light with no net polarization, but optically active cyclometalated iridium (III) complexes emit circularly polarized light. 8,9 Circularly polarized light can be used in various fields including highly efficient three dimensional electronic devices, photo nic devices for optical data storage, biological assays, and others. 8,9 In order to obtain optically active cylometalated iridium (III) complexes and to determine the enantiomeric composition of optically active cylometalated iridium (III) complexes, liquid chromatogr aphic enantiomer separation method on chiral stationary phases (CSPs) has been used. For example, Okamoto and coworkers first reported the high performance liquid chromatographic (HPLC) direct enantiomeric separation of two homoleptic cylometalated iridium (III) complexes on immobilized amylose tris(3,5- dimethylphenylcarbamate) (Chiralpak IA), coated cellulose tris(3,5-dimethylphenylcarbamate) (Chiralc el OD), and coated cellulose tris(4-methylbenzoate) (Chiralce l OJ). 10 Supercritical fluid chromatography (SFC) was also used by Bernhard and coworkers for the enantiomeric separation of cylometalated iridium (III) complexes on coated amylose tris(3,5-dimethylphenylcarbamate) (Chiralpak AD-H). 8 However, the general use of the HPLC method for the direct enantiomeric separation of homoleptic

Enantiomeric separation of iridium (III) complexes using HPLC chiral stationary phases based on amylose derivatives

Energy Technology Data Exchange (ETDEWEB)

Kim, Hee Eun; Seo, Na Hyeon; Hyun, Myung Ho [Dept. of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Busan (Korea, Republic of)

2016-12-15

Cyclometalated iridium (III) complexes formed with three identical cyclometalating (C-N) ligands (homoleptic) or formed with two cyclometalating (C-N) ligands and one ancillary (LX) ligand (heteroleptic) have been known as highly phosphorescent materials and, thus, they have been utilized as efficient phosphorescent dopants in organic light emitting diodes (OLEDs) 1–3 or as effective phosphorescent chemosensors. 4–7 Cylometalated iridium (III) complexes are chiral compounds consisting of lambda (Λ, left-handed) and delta (Δ, right-handed) isomers. Racemic cyclometa- lated iridium (III) complexes emit light with no net polarization, but optically active cyclometalated iridium (III) complexes emit circularly polarized light. 8,9 Circularly polarized light can be used in various fields including highly efficient three dimensional electronic devices, photo nic devices for optical data storage, biological assays, and others. 8,9 In order to obtain optically active cylometalated iridium (III) complexes and to determine the enantiomeric composition of optically active cylometalated iridium (III) complexes, liquid chromatogr aphic enantiomer separation method on chiral stationary phases (CSPs) has been used. For example, Okamoto and coworkers first reported the high performance liquid chromatographic (HPLC) direct enantiomeric separation of two homoleptic cylometalated iridium (III) complexes on immobilized amylose tris(3,5- dimethylphenylcarbamate) (Chiralpak IA), coated cellulose tris(3,5-dimethylphenylcarbamate) (Chiralc el OD), and coated cellulose tris(4-methylbenzoate) (Chiralce l OJ). 10 Supercritical fluid chromatography (SFC) was also used by Bernhard and coworkers for the enantiomeric separation of cylometalated iridium (III) complexes on coated amylose tris(3,5-dimethylphenylcarbamate) (Chiralpak AD-H). 8 However, the general use of the HPLC method for the direct enantiomeric separation of homoleptic.

Vicinal Diboronates in High Enantiomeric Purity through Tandem Site-Selective NHC–Cu-Catalyzed Boron-Copper Additions to Terminal Alkynes

Science.gov (United States)

Lee, Yunmi; Jang, Hwanjong; Hoveyda, Amir H.

2009-01-01

A Cu-catalyzed protocol for conversion of terminal alkynes to enantiomerically enriched diboronates is reported. In a single vessel, a site-selective hydroboration of an alkyne leads to the corresponding terminal vinylboronate, which undergoes a second site-selective and enantioselective hydroboration. Reactions proceed in the presence of two equivalents of commercially available bis(pinacolato)diboron [B2(pin)2] and 5–7.5 mol % of a chiral bidentate imidazolinium salt, affording diboronates in 60–93% yield and up to 97.5:2.5 enantiomeric ratio (er). The enantiomerically enriched products can be functionalized to afford an assortment of versatile organic molecules. Enynes are converted to unsaturated diboronates with high chemo- (>98% reaction of alkyne; <2% at alkene) and enantioselectivity (e.g., 94.5:5.5 er). PMID:19968273

Enantiomeric separation of complex organic molecules produced from irradiation of interstellar/circumstellar ice analogs

Science.gov (United States)

Nuevo, M.; Meierhenrich, U. J.; D'Hendecourt, L.; Muñoz Caro, G. M.; Dartois, E.; Deboffle, D.; Thiemann, W. H.-P.; Bredehöft, J.-H.; Nahon, L.

Irradiation of interstellar/circumstellar ice analogs by ultraviolet (UV) light followed by warm up in the laboratory leads to the formation of complex organic molecules, stable at room temperature. Hydrolysis of the room temperature residue releases amino acids, the building blocks of proteins. These amino acids exist in two different forms (L and D), but proteins encountered in living beings consist exclusively of L enantiomers. The origin of this property, called homochirality, is still unknown. Amino acids can be detected and quantified by chemical techniques such as chiral gas chromatography coupled with mass spectrometry (GC-MS). Enantiomers of chiral organics are also known to interact selectively with circularly polarized light (CPL), leading to a selective production or destruction of the final compounds. This paper describes how we settled an experiment where amino acids are formed by irradiation of interstellar/circumstellar ice analogs with ultraviolet (UV) CPL, produced by a synchrotron radiation beamline, which allowed us to quantify the effect of such polarized light on the production of amino acids. These results can be compared to the enantiomeric excesses measured in primitive meteorites such as Murchison.

Anisotropy Spectra for Enantiomeric Differentiation of Biomolecular Building Blocks

DEFF Research Database (Denmark)

Evans, Amanda C.; Meinert, Cornelia; Bredehoft, Jan H.

2013-01-01

All biopolymers are composed of homochiral building blocks, and both D-sugars and L-amino acids uniquely constitute life on Earth. These monomers were originally enantiomerically differentiated under prebiotic conditions. Particular progress has recently been made in support of the photochemical...... light. This chapter will: (1) present the theory and configuration of anisotropy spectroscopy; (2) explain experimentally recorded anisotropy spectra of selected chiral biomolecules such as amino acids; and (3) discuss the relevance of these spectra for the investigation of the origin of the molecular...

Synthesis and Absolute Configuration of Enantiomerically Pure Vitamin K3 2,3-Epoxide

NARCIS (Netherlands)

Snatzke, Günther; Wijnberg, Hans; Feringa, Bernard; Marsman, Bea G.; Greydanus, Ben; Pluim, Henk

1980-01-01

The 2,3-epoxide of vitamin K3 (menadione, 1) has been prepared in enantiomerically pure form, and the absolute configuration has been deduced from the CD spectrum. The compound with the negative Cotton effect between 340 and 400 nm has the 2R,3S configuration.

A note on the Noyori model for chiral amplification in the aminoalcohol-catalyzed reaction of aldehydes with dialkylzinc

Directory of Open Access Journals (Sweden)

IVAN GUTMAN

1999-11-01

Full Text Available The Noyori model of chiral amplification in the alkylation of aldehydes by means of dialkylzinc, catalyzed by chiral aminoalcohols, is further elaborated. A direct, but approximate, relation is obtained between the enantiomeric excess of the catalyst added and the enantiomeric excess of the product.

Homochiral Acyl Isocyanates as Diagnostic NMR Probes for the Enantiomeric Purity of Chiral Alcohols

Directory of Open Access Journals (Sweden)

Gregory H. P. Roos

2000-12-01

Full Text Available The first reported acyl and sulfonylisocyanates were developed and tested in reactions with chiral alcohols to afford diastereomeric carbamates. NMR analysis of these investigates the chemical shift discrimination that would allow these activated isocyanates to be used as diagnostic probes of enantiomeric purity.

Enantioseparations of amino acids by capillary array electrophoresis with 532 nm laser induced fluorescence detection.

Science.gov (United States)

Liu, Kaiying; Wang, Li

2013-06-21

Capillary array electrophoresis (CAE) is a promising technique for multiple enantiomeric separations. Carboxytetramethylrhodamine succinimidyl ester (TAMRA SE), a rhodamine-core fluorescent probe, has rarely been applied as an original precolumn derivatization reagent for chiral amino acid (AA) analysis so far. For these purposes, high-throughput enantiomeric separations of 12 TAMRA SE-AAs by a home-made 532 nm CAE-LIF scanner are presented. The effect of cyclodextrins (CDs) and a variety of organic modifiers was quickly investigated. Baseline separations were achieved in 100 mM Tris-borate buffer (pH 10.0) containing 2 mM β-CD and 10 mM hexamethylenediamine (HDA). Multiple determination of the enantiomeric excess (ee) in non-racemic mixtures of alanine is successfully presented. Copyright © 2013 Elsevier B.V. All rights reserved.

ACTIVATION PARAMETERS AND EXCESS THERMODYANAMIC ...

African Journals Online (AJOL)

Applying these data, viscosity-B-coefficients, activation parameters (Δμ10≠) and (Δμ20≠) and excess thermodynamic functions, viz., excess molar volume (VE), excess viscosity, ηE and excess molar free energy of activation of flow, (GE) were calculated. The value of interaction parameter, d, of Grunberg and Nissan ...

Enantiomeric ratios as an indicator of exposure processes for persistent pollutants in human placentas

DEFF Research Database (Denmark)

Shen, Heqing; Virtanen, H E; Main, Katharina M

2006-01-01

The enantiomeric ratios (ER) of alpha-HCH and o,p'-DDT ((+)-isomer concentration/(-)-isomer concentration) and o,p'-DDD (first eluting enantiomer/second enantiomer) were investigated in 112 human placentas from Finnish boys collected 1997-2001. Both o,p'-DDD and alpha-HCH showed changes in their ER...

Elucidating the existence of the excess wing in an ionic liquid on applying pressure

Energy Technology Data Exchange (ETDEWEB)

Rivera-Calzada, A; Leon, C [GFMC, Departamento de Fisica Aplicada 3, Universidad Complutense de Madrid (Spain); Kaminski, K; Paluch, M [Institute of Physics, Silesian University, Katowice (Poland)], E-mail: Alberto.Rivera@fis.ucm.es

2008-06-18

We report a study of the dynamic relaxation spectra of the ionic liquid 1-butyl-1-methylpyrrolidinium bis[oxalato]borate (BMP-BOB) by means of dielectric spectroscopy in wide temperature (123-300 K) and pressure (0.1-500 MPa) ranges. We find similar features to those observed in many conventional glass formers. The relaxation time of the primary relaxation {tau}{sub {alpha}} strongly increases with applied pressure, while that of the secondary relaxation is almost insensitive to pressure. However, the shape of the primary relaxation at constant {tau}{sub {alpha}} is the same whether the pressure is 0.1 or 500 MPa. Elevated pressure separates the secondary relaxation and makes possible the appearance of an excess wing on the high-frequency flank of the primary relaxation. Interestingly, the primitive relaxation time calculated by the coupling model falls in the range of the existence of the excess wing of BMP-BOB, suggesting an unresolved universal Johari-Goldstein {beta}-relaxation.

Design and synthesis of enantiomerically enriched, radiolabeled MK-801 analogs as potential radiotracers for imaging and autoradiographic studies of the NMDA receptor-ion channel complex

International Nuclear Information System (INIS)

Eng, W.S.; Burns, H.D.; Gibson, R.E.; Ransom, R.W.; Thorpe, H.; Fioravanit, C.; Britcher, S.F.; Magill, C.A.; Solomon, H.F.; Dannals, R.F.; Wilson, A.A.; Ravert, H.T.; Wagner, H.N.

1989-01-01

MK-801 is a potent, non-competitive antagonist for the N-methyl-D-asspartate (NMDA) receptor-ion channel complex. This complex is though to be involved in nerve cell damage in stroke patients when excess calcium is released through the activated channel. A thorough understanding of drug interactions with the NMDA receptor complex could lead to improved therapy for reducing hypoxic-ischemic neuronal injuries in stroke patients. Based on the results of extensive structure-activity studies, the authors have developed several enantiomerically enriched, radiolabeled analogs of MK-801, including: 3-1231-MK-801 for Single Photon Emission Computed tomography (SPECT); 3-1251-MK-801 for in-vivo and in-vitro autoradiography; 8-11C-MeO-MK-801 for Positron Emission Tomography (PET). Details of the synthesis of these radiotracers and their application to both in-vitro and in-vivo studies are described

Stereocomplex micelle from nonlinear enantiomeric copolymers efficiently transports antineoplastic drug

Science.gov (United States)

Wang, Jixue; Shen, Kexin; Xu, Weiguo; Ding, Jianxun; Wang, Xiaoqing; Liu, Tongjun; Wang, Chunxi; Chen, Xuesi

2015-05-01

Nanoscale polymeric micelles have attracted more and more attention as a promising nanocarrier for controlled delivery of antineoplastic drugs. Herein, the doxorubicin (DOX)-loaded poly(D-lactide)-based micelle (PDM/DOX), poly(L-lactide)-based micelle (PLM/DOX), and stereocomplex micelle (SCM/DOX) from the equimolar mixture of the enantiomeric four-armed poly(ethylene glycol)-polylactide (PEG-PLA) copolymers were successfully fabricated. In phosphate-buffered saline (PBS) at pH 7.4, SCM/DOX exhibited the smallest hydrodynamic diameter ( D h) of 90 ± 4.2 nm and the slowest DOX release compared with PDM/DOX and PLM/DOX. Moreover, PDM/DOX, PLM/DOX, and SCM/DOX exhibited almost stable D hs of around 115, 105, and 90 nm at above normal physiological condition, respectively, which endowed them with great potential in controlled drug delivery. The intracellular DOX fluorescence intensity after the incubation with the laden micelles was different degrees weaker than that incubated with free DOX · HCl within 12 h, probably due to the slow DOX release from micelles. As the incubation time reached to 24 h, all the cells incubated with the laden micelles, especially SCM/DOX, demonstrated a stronger intracellular DOX fluorescence intensity than free DOX · HCl-cultured ones. More importantly, all the DOX-loaded micelles, especially SCM/DOX, exhibited potent antineoplastic efficacy in vitro, excellent serum albumin-tolerance stability, and satisfactory hemocompatibility. These encouraging data indicated that the loading micelles from nonlinear enantiomeric copolymers, especially SCM/DOX, might be promising in clinical systemic chemotherapy through intravenous injection.

Enantiomeric profiling of a chemically diverse mixture of chiral pharmaceuticals in urban water

International Nuclear Information System (INIS)

Evans, S.; Bagnall, J.; Kasprzyk-Hordern, B.

2017-01-01

Due to concerns regarding the release of pharmaceuticals into the environment and the understudied impact of stereochemistry of pharmaceuticals on their fate and biological potency, we focussed in this paper on stereoselective transformation pathways of selected chiral pharmaceuticals (16 pairs) at both microcosm (receiving waters and activated sludge wastewater treatment simulating microcosms) and macrocosm (wastewater treatment plant (WWTP) utilising activated sludge technology and receiving waters) scales in order to test the hypothesis that biodegradation of chiral drugs is stereoselective. Our monitoring programme of a full scale activated sludge WWTP and receiving environment revealed that several chiral drugs, those being marketed mostly as racemates, are present in wastewater and receiving waters enriched with one enantiomeric form (e.g. fluoxetine, mirtazapine, salbutamol, MDMA). This is most likely due to biological metabolic processes occurring in humans and other organisms. Both activated sludge and receiving waters simulating microcosms confirmed our hypothesis that chiral drugs are subject to stereoselective microbial degradation. It led, in this research, to preferential degradation of S-(+)-enantiomers of amphetamines, R-(+)-enantiomers of beta-blockers and S-(+)-enantiomers of antidepressants. In the case of three parent compound – metabolite pairs (venlafaxine – desmethylvenlafaxine, citalopram – desmethylcitalopram and MDMA - MDA), while parent compounds showed higher resistance to both microbial metabolism and photodegradation, their desmethyl metabolites showed much higher degradation rate both in terms of stereoselective metabolic and non-stereoselective photochemical processes. It is also worth noting that metabolites tend to be, as expected, enriched with enantiomers of opposite configuration to their parent compounds, which might have significant toxicological consequences when evaluating the metabolic residues of chiral pollutants

Enantiomeric metabolic interactions and stereoselective human methadone metabolism.

Science.gov (United States)

Totah, Rheem A; Allen, Kyle E; Sheffels, Pamela; Whittington, Dale; Kharasch, Evan D

2007-04-01

Methadone is administered as a racemate, although opioid activity resides in the R-enantiomer. Methadone disposition is stereoselective, with considerable unexplained variability in clearance and plasma R/S ratios. N-Demethylation of methadone in vitro is predominantly mediated by cytochrome P450 CYP3A4 and CYP2B6 and somewhat by CYP2C19. This investigation evaluated stereoselectivity, models, and kinetic parameters for methadone N-demethylation by recombinant CYP2B6, CYP3A4, and CYP2C19, and the potential for interactions between enantiomers during racemate metabolism. CYP2B6 metabolism was stereoselective. CYP2C19 was less active, and stereoselectivity was opposite that for CYP2B6. CYP3A4 was not stereoselective. With all three isoforms, enantiomer N-dealkylation rates in the racemate were lower than those of (R)-(6-dimethyamino-4,4-diphenyl-heptan-3-one) hydrochloride (R-methadone) or (S)-(6-dimethyamino-4,4-diphenyl-heptan-3-one) hydrochloride (S-methadone) alone, suggesting an enantiomeric interaction and mutual metabolic inhibition. For CYP2B6, the interaction between enantiomers was stereoselective, with S-methadone as a more potent inhibitor of R-methadone N-demethylation than R-of S-methadone. In contrast, enantiomer interactions were not stereoselective with CYP2C19 or CYP3A4. For all three cytochromes P450, methadone N-demethylation was best described by two-site enzyme models with competitive inhibition. There were minor model differences between cytochromes P450 to account for stereoselectivity of metabolism and enantiomeric interactions. Changes in plasma R/S methadone ratios observed after rifampin or troleandomycin pretreatment in humans in vivo were successfully predicted by CYP2B6- but not CYP3A4-catalyzed methadone N-demethylation. CYP2B6 is a predominant catalyst of stereoselective methadone metabolism in vitro. In vivo, CYP2B6 may be a major determinant of methadone metabolism and disposition, and CYP2B6 activity and stereoselective metabolic

Direct resolution and quantitative analysis of flurbiprofen enantiomers using microcrystalline cellulose triacetate plates: applications to the enantiomeric purity control and optical isomer determination in widely consumed drugs.

Science.gov (United States)

Del Bubba, M; Checchini, L; Ciofi, L; Furlanetto, S; Lepri, L

2014-01-01

Flurbiprofen enantiomers have very different pharmacological properties, since the (S)-(+) form has a much higher anti-inflammatory activity than the (R)-(-) isomer, the latter being responsible for very undesirable side effects, such as gastrointestinal irritation. Based on the different biological properties of flurbiprofen enantiomers, the development of chiral chromatographic methods for the control of the enantiomeric purity is a very important topic. In this study the separation of flurbiprofen enantiomers was achieved using for the first time noncommercial MCTA layers with polyvinyl alcohol as binder, which gives to these plates a mechanical stability equivalent to that of marketed ones. Baseline resolution (α = 1.31; RS = 2.0) was obtained with ethanol-acetic acid solution (pH 3.0 ± 0.1; 60:40, v/v) as eluent and a migration distance of about 14.5 cm. Under these experimental conditions, the thin-layer chromatography determination of the enantiomeric purity of the pharmacologically active (S)-(+)-flurbiprofen in the presence of 1% of the undesired (R)-(-) form was demonstrated. Moreover, the quantitative analysis of flurbiprofen enantiomers was achieved, obtaining quantification limits and detection limits of 50 and 25 ng of each enantiomer applied to the plate, respectively. The method was succesfully applied to the enantiomer determination in widely consumed drugs, obtaining results consistent with the flurbiprofen content declared in the drug facts. Copyright © 2013 John Wiley & Sons, Ltd.

Synthesis of radiolabeled racemic and enantiomeric antiarrhythmic agents

Energy Technology Data Exchange (ETDEWEB)

Stolle, W.T.; Stelzer, L.S.; Hester, J.B.; Perricone, S.C.; Hsi, R.S.P. (Upjohn Co., Kalamazoo, MI (United States))

1994-10-01

Ibutilide fumarate, racemic N-[4-[4-(ethyl-n-heptylamino)-hydroxybutyl]phenyl]methanesulfonamide hemifumarate, and artilide, the R-(+)-enantiomer of N-[4-[4-(ethyl-n-heptylamino)-hydroxybutyl]phenyl]methanesulfonamide hemifumerate, are under clinical investigation as Class III antiarrhythmic agents. For conducting drug disposition studies, we synthesized carbon-14 labeled ibutilide, as well as its two enantiomeric forms. In addition, high specific activity tritium labeled ibutilide was also prepared to facilitate development of a radioimmunoassay and for studying receptor site characteristics of this agent. Results of metabolism studies with [[sup 14]C]ibutilide led us to prepare tritium labeled artilide, which is more readily accessible than the C-14 labeled drug. The optical antipode of artilide was also labeled with tritium for comparative drug disposition investigations on the two enantiomers. (author).

Chemoenzymatic Dynamic Kinetic Resolution: A Powerful Tool for the Preparation of Enantiomerically Pure Alcohols and Amines

Science.gov (United States)

2015-01-01

Chemoenzymatic dynamic kinetic resolution (DKR) constitutes a convenient and efficient method to access enantiomerically pure alcohol and amine derivatives. This Perspective highlights the work carried out within this field during the past two decades and pinpoints important avenues for future research. First, the Perspective will summarize the more developed area of alcohol DKR, by delineating the way from the earliest proof-of-concept protocols to the current state-of-the-art systems that allows for the highly efficient and selective preparation of a wide range of enantiomerically pure alcohol derivatives. Thereafter, the Perspective will focus on the more challenging DKR of amines, by presenting the currently available homogeneous and heterogeneous methods and their respective limitations. In these two parts, significant attention will be dedicated to the design of efficient racemization methods as an important means of developing milder DKR protocols. In the final part of the Perspective, a brief overview of the research that has been devoted toward improving enzymes as biocatalysts is presented. PMID:25730714

Tris[(6S)-6-hy-droxy-4-epi-shikimic acid] monohydrate: an enanti-omerically pure hy-droxy-lated shikimic acid derived from methyl shikimate.

Science.gov (United States)

Griesbeck, Axel G; Miara, Claus; Neudörfl, Jörg-M

2012-11-01

The title compound, 3C(7)H(10)O(6)·H(2)O, is the enanti-omerically pure product of a multi-step synthesis from the enanti-omerically pure natural shikimic acid. The asymmetric unit contains three mol-ecules of the acid and one mol-ecule of water. The cyclo-hexene rings of the acids have half-chair conformations. The carboxyl-ate, the four hydroxide groups and the additional water mol-ecule form a complex three-dimensional hydrogen-bonding network.

Lipases and whole cell biotransformations of 2-hydroxy-2-(ethoxyphenylphosphinyl)acetic acid and its ester.

Science.gov (United States)

Majewska, Paulina; Serafin, Monika; Klimek-Ochab, Magdalena; Brzezińska-Rodak, Małgorzata; Żymańczyk-Duda, Ewa

2016-06-01

A wide spectrum of commercially available lipases and microbial whole cells catalysts were tested for biotransformations of 2-hydroxy-2-(ethoxyphenylphosphinyl)acetic acid 1 and its butyryl ester. The best results were achieved for biocatalytic hydrolysis of ester: 2-butyryloxy-2-(ethoxyphenylphosphinyl)acetic acid 2 performed by lipase from Candida cylindracea, what gave optically active products with 85% enantiomeric excess, 50% conversion degree and enantioselectivity 32.9 for one pair of enantiomers. Also enzymatic systems of Penicillium minioluteum and Fusarium oxysporum were able to hydrolyze tested compound with high enantiomeric excess (68-93% ee), enantioselectivity (44 for one pair of enantiomers) and conversion degree about 50-55%. Enzymatic acylation of hydroxyphosphinate was successful in case when porcine pancreas lipase was used. After 4days of biotransformation the conversion reaches 45% but the enantiomeric enrichment of the isomers mixture do not exceed 43%. Obtained chiral compounds are valuable derivatizing agents for spectroscopic (NMR) evaluation of enantiomeric excess for particular compounds (e.g. amino acids). Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Development of Chiral LC-MS Methods for small Molecules and Their Applications in the Analysis of Enantiomeric Composition and Pharmacokinetic Studies

Energy Technology Data Exchange (ETDEWEB)

Desai, Meera Jay [Iowa State Univ., Ames, IA (United States)

2004-01-01

The purpose of this research was to develop sensitive LC-MS methods for enantiomeric separation and detection, and then apply these methods for determination of enantiomeric composition and for the study of pharmacokinetic and pharmacodynamic properties of a chiral nutraceutical. Our first study, evaluated the use of reverse phase and polar organic mode for chiral LC-API/MS method development. Reverse phase methods containing high water were found to decrease ionization efficiency in electrospray, while polar organic methods offered good compatibility and low limits of detection with ESI. The use of lower flow rates dramatically increased the sensitivity by an order of magnitude. Additionally, for rapid chiral screening, the coupled Chirobiotic column afforded great applicability for LC-MS method development. Our second study, continued with chiral LC-MS method development in this case for the normal phase mode. Ethoxynonafluorobutane, a fluorocarbon with low flammability and no flashpoint, was used as a substitute solvent for hexane/heptane mobile phases for LC-APCI/MS. Comparable chromatographic resolutions and selectivities were found using ENFB substituted mobile phase systems, although, peak efficiencies were significantly diminished. Limits of detection were either comparable or better for ENFB-MS over heptane-PDA detection. The miscibility of ENFB with a variety of commonly used organic modifiers provided for flexibility in method development. For APCI, lower flow rates did not increase sensitivity as significantly as was previously found for ESI-MS detection. The chiral analysis of native amino acids was evaluated using both APCI and ESI sources. For free amino acids and small peptides, APCI was found to have better sensitivities over ESI at high flow rates. For larger peptides, however, sensitivity was greatly improved with the use of electrospray. Additionally, sensitivity was enhanced with the use of non-volatile additives, This optimized method was then

Optimisation of the enantioselective biocatalytic hydrolysis of naproxen ethyl ester using ChiroCLEC-CR

CSIR Research Space (South Africa)

Brady, D

2004-03-04

Full Text Available In a biocatalytic reaction the immobilized lipase ChiroCLEC-CR enantioselectively hydrolysed a naproxen ethyl ester racemate, yielding (S)-naproxen with an enantiomeric excess of more than 98%, an enantiomeric ratio (E) of more than 100...

Treatment of Oral Biofilms by a D-Enantiomeric Peptide.

Science.gov (United States)

Zhang, Tian; Wang, Zhejun; Hancock, Robert E W; de la Fuente-Núñez, César; Haapasalo, Markus

2016-01-01

Almost all dental diseases are caused by biofilms that consist of multispecies communities. DJK-5, which is a short D-enantiomeric, protease-resistant peptide with broad-spectrum anti-biofilm activity, was tested for its effect on oral multispecies biofilms. Peptide DJK-5 at 10 μg/mL effectively prevented the growth of these microbes in culture media in a time-dependent manner. In addition to the prevention of growth, peptide DJK-5 completely killed both Streptococcus mutans and Enterococcus faecalis suspended from biofilms after 30 minutes of incubation in liquid culture media. DJK-5 also led to the effective killing of microbes in plaque biofilm. The proportion of bacterial cells killed by 10 μg/mL of DJK-5 was similar after 1 and 3 days, both exceeding 85%. DJK-5 was able to significantly prevent biofilm formation over 3 days (P = 0.000). After 72 hours of exposure, DJK-5 significantly reduced and almost completely prevented plaque biofilm production by more than 90% of biovolume compared to untreated controls (P = 0.000). The proportion of dead biofilm bacteria at the 10 μg/mL DJK-5 concentration was similar for 1- and 3-day-old biofilms, whereby >86% of the bacteria were killed. DJK-5 was also able to kill >79% and >85% of bacteria, respectively, after one-time and three brief treatments of 3-day-old biofilms. The combination of DJK-5 and chlorhexidine showed the best bacterial killing among all treatments, with ~83% and >88% of bacterial cells killed after 1 and 3 minutes, respectively. No significant difference was found in the percentage of biofilm killing amongst three donor plaque samples after DJK-5 treatment. In particular, DJK-5 showed strong performance in inhibiting biofilm development and eradicating pre-formed oral biofilms compared to L-enantiomeric peptide 1018. DJK-5 was very effective against oral biofilms when used alone or combined with chlorhexidine, and may be a promising agent for use in oral anti-biofilm strategies in the future.

Enantioselectivity of a recombinant epoxide hydrolase from Agrobacterium radiobacter

NARCIS (Netherlands)

Lutje Spelberg, Jeffrey H.; Rink, Rick; Kellogg, Richard M.; Janssen, Dick B.

1998-01-01

The recombinant epoxide hydrolase from Agrobacterium radiobacter AD1 was used to obtain enantiomerically pure epoxides by means of a kinetic resolution. Epoxides such as styrene oxide and various derivatives thereof and phenyl glycidyl ether were obtained in high enantiomeric excess and in

Prokaryotic Selectivity, Anti-endotoxic Activity and Protease Stability of Diastereomeric and Enantiomeric Analogs of Human Antimicrobial Peptide LL-37

International Nuclear Information System (INIS)

Nan, Yong Hai; Lee, Bongju; Shin, Song Yub

2012-01-01

LL-37 is the only antimicrobial peptide (AMP) of the human cathelicidin family. In addition to potent antimicrobial activity, LL-37 is known to have the potential to inhibit lipolysaccharide (LPS)-induced endotoxic effects. To provide the stability to proteolytic digestion and increase prokaryotic selectivity and/or anti-endotoxic activity of two Lys/Trp-substituted 19-meric anti-microbial peptides (a4-W1 and a4-W2) designed from IG-19 (residues 13-31 of LL-37), we synthesized the diastereomeric peptides (a4-W1-D and a4-W2-D) with D-amino acid substitution at positions 3, 7, 10, 13 and 17 of a4-W1 and a4-W2, respectively and the enantiomeric peptides (a4-W1-E and a4-W2-E) composed D-amino acids. The diastereomeric peptides exhibited the best prokaryotic selectivity and effective protease stability, but no or less anti-endotoxic activity. In contrast, the enantiomeric peptides had not only prokaryotic selectivity and anti-endotoxic activity but also protease stability. Our results suggest that the hydrophobicity and α-helicity of the peptide is important for anti-endotoxic activity. In particular, the enantiomeric peptides showed potent anti-endotoxic and LPS-neutralizing activities comparable to that of LL-37. Taken together, both a4-W1-E and a4-W2-E holds promise as a template for the development of peptide antibiotics for the treatment of endotoxic shock and sepsis

Prokaryotic Selectivity, Anti-endotoxic Activity and Protease Stability of Diastereomeric and Enantiomeric Analogs of Human Antimicrobial Peptide LL-37

Energy Technology Data Exchange (ETDEWEB)

Nan, Yong Hai; Lee, Bongju; Shin, Song Yub [Chosun Univ., Gwangju (Korea, Republic of)

2012-09-15

LL-37 is the only antimicrobial peptide (AMP) of the human cathelicidin family. In addition to potent antimicrobial activity, LL-37 is known to have the potential to inhibit lipolysaccharide (LPS)-induced endotoxic effects. To provide the stability to proteolytic digestion and increase prokaryotic selectivity and/or anti-endotoxic activity of two Lys/Trp-substituted 19-meric anti-microbial peptides (a4-W1 and a4-W2) designed from IG-19 (residues 13-31 of LL-37), we synthesized the diastereomeric peptides (a4-W1-D and a4-W2-D) with D-amino acid substitution at positions 3, 7, 10, 13 and 17 of a4-W1 and a4-W2, respectively and the enantiomeric peptides (a4-W1-E and a4-W2-E) composed D-amino acids. The diastereomeric peptides exhibited the best prokaryotic selectivity and effective protease stability, but no or less anti-endotoxic activity. In contrast, the enantiomeric peptides had not only prokaryotic selectivity and anti-endotoxic activity but also protease stability. Our results suggest that the hydrophobicity and α-helicity of the peptide is important for anti-endotoxic activity. In particular, the enantiomeric peptides showed potent anti-endotoxic and LPS-neutralizing activities comparable to that of LL-37. Taken together, both a4-W1-E and a4-W2-E holds promise as a template for the development of peptide antibiotics for the treatment of endotoxic shock and sepsis.

Investigating Ionic Effects Applied to Water Based Organocatalysed Aldol Reactions

Directory of Open Access Journals (Sweden)

Joshua P. Delaney

2011-12-01

Full Text Available Saturated aqueous solutions of various common salts were examined for their effect on aqueous aldol reactions catalysted by a highly active C2-symmetric diprolinamide organocatalyst developed in our laboratory. With respect to the aldol reaction between cyclohexanone and 4-nitrobenzaldehyde, deionised water was always a superior medium to salt solutions though some correlation to increasing anion size and depression in enantiomeric excess could be observed. Additionally, the complete inhibition of catalyst activity observed when employing tap water could be alleviated by the inclusion of ethylenediaminetetraacetate (EDTA into the aqueous media prior to reaction initiation. Extension of these reaction conditions demonstrated that these ionic effects vary on a case-to-case basis depending on the ketone/aldehyde combination.

Enantiomeric determination of DOPA in dietary supplements containing Mucuna pruriens by liquid chromatography/mass spectrometry.

Science.gov (United States)

Hasegawa, Takashi; Takahashi, Kazunaga; Fukiwake, Tomohide; Saijo, Masaaki; Motoki, Yuji

2013-01-01

We developed a simple and rapid liquid chromatography/mass spectrometry (LC/MS) method for the enantiomeric determination of DOPA in dietary supplements containing Mucuna pruriens. L- and D-DOPA were ultrasonically extracted with 1% formic acid aqueous solution. The isolated extracts were analyzed by LC/MS using a Crownpak CR (-) column at 30℃. The mass spectrometer was operated in the positive mode of electrospray ionization, and the mobile phase was aqueous formic acid (pH 2.0). L-DOPA-ring-d3 was used as an internal standard. The method was validated for a dietary supplement spiked with L- and D-DOPA at 50 and 500 μg/g, respectively, and the recoveries of the DOPA enantiomers were between 97.5% and 101.3%. Relative standard deviation values of repeatability and intermediate precision were less than 7%. The method was applied to 14 dietary supplements. L-DOPA was detected in these supplements in the range of 0.88-12.8 mg/unit. D-DOPA was not detected.

Stereoselective synthesis of unsaturated α-amino acids.

Science.gov (United States)

Fanelli, Roberto; Jeanne-Julien, Louis; René, Adeline; Martinez, Jean; Cavelier, Florine

2015-06-01

Stereoselective synthesis of unsaturated α-amino acids was performed by asymmetric alkylation. Two methods were investigated and their enantiomeric excess measured and compared. The first route consisted of an enantioselective approach induced by the Corey-Lygo catalyst under chiral phase transfer conditions while the second one involved the hydroxypinanone chiral auxiliary, both implicating Schiff bases as substrate. In all cases, the use of a prochiral Schiff base gave higher enantiomeric excess and yield in the final desired amino acid.

Simultaneous determination of diastereoisomeric and enantiomeric impurities in SSS-octahydroindole-2-carboxylic acid by chiral high-performance liquid chromatography with pre-column derivatization.

Science.gov (United States)

Wang, Jin Zhao; Zeng, Su; Hu, Gong Yun; Wang, Dan Hua

2009-04-10

SSS-Octahydroindole-2-carboxylic acid (SSS-Oic) is a key intermediate used in the synthesis of some angiotensin-converting enzyme (ACE) inhibitors. The separation of diastereoisomers and enantiomers of Oic was performed using a pre-column derivatization chiral HPLC method. Phenyl isothiocyanate (PITC) was used as the derivatization reagent. Three PITC derivatives of Oic stereoisomers were separated on an Ultron ES-OVM chiral column (150 mm x 4.6 mm, 5 microm). Derivatization conditions such as reaction temperature, reaction time and derivatization reagent concentration were investigated. The chromatographic conditions for separation of the three PITC-Oic derivatives were optimized. The method was successfully applied in the diastereoisomeric and enantiomeric purity test of SSS-Oic.

Amino Acids and Chirality

Science.gov (United States)

Cook, Jamie E.

2012-01-01

Amino acids are among the most heavily studied organic compound class in carbonaceous chondrites. The abundance, distributions, enantiomeric compositions, and stable isotopic ratios of amino acids have been determined in carbonaceous chondrites fi'om a range of classes and petrographic types, with interesting correlations observed between these properties and the class and typc of the chondritcs. In particular, isomeric distributions appear to correlate with parent bodies (chondrite class). In addition, certain chiral amino acids are found in enantiomeric excess in some chondrites. The delivery of these enantiomeric excesses to the early Earth may have contributed to the origin of the homochirality that is central to life on Earth today. This talk will explore the amino acids in carbonaceous chondritcs and their relevance to the origin of life.

Chemoenzymatic resolution of {beta}-azidophenylethanols by Candida antarctica and their application for the synthesis of chiral benzotriazoles

Energy Technology Data Exchange (ETDEWEB)

Rocha, Lenilson C.; Rosset, Isac G.; Melgar, Gliseida Z.; Porto, Andre L.M. [Universidade de Sao Paulo (IQ/USP), Sao Carlos, SP (Brazil). Inst. de Quimica; Raminelli, Cristiano [Universidade Federal de Sao Paulo, Diadema, SP (Brazil). Dept. de Ciencias Exatas e da Terra; Jeller, Alex H., E-mail: alexjell@uems.br [Universidade Estadual de Mato Grosso do Sul (UEMS), Dourados, MS (Brazil). Coordenacao de Quimica

2013-09-15

The kinetic resolutions of ({+-})-{beta}-azidophenylethanols were carried out using lipase from Candida antarctica, and enantiomerically enriched (R)-{beta}-azidophenylethanols and their corresponding (S)-{beta}-azidophenylethyl acetates were obtained in good enantiomeric excesses (up to > 99%). The enantiomerically enriched (R)-{beta}-azidophenylethanols were subjected to cyclization reaction with 2-(trimethylsilyl)phenyl triflate and CsF producing chiral 1,2,3-benzotriazole compounds in good yields (75-86%) by a [3 + 2] cycloaddition, which involves the benzyne formation. (author)

Occurrence of organochlorine pesticides (OCPs) and their enantiomeric signatures, and concentrations of polybrominated diphenyl ethers (PBDEs) in the Adelie penguin food web, Antarctica

International Nuclear Information System (INIS)

Corsolini, Simonetta; Covaci, Adrian; Ademollo, Nicoletta; Focardi, Silvano; Schepens, Paul

2006-01-01

Concentrations and enantiomeric signatures of organochlorine pesticides were determined in Antarctic krill, emerald rockcod and Adelie penguin from the Ross Sea, Antarctica. HCB and DDTs were prevalent contaminants in penguin eggs. The highest concentrations of ΣHCHs (1.35 ± 0.72 ng/g) were found in the rockcod muscle, where γ-HCH (1.23 ± 0.67 ng/g) was the principal isomer. The ratio γ-HCH/α-HCH was evaluated. Enantioselective gas chromatography was used for the evaluation of enantiomeric fractions (EFs) for α-HCH and oxychlordane. An increase of 14% in the (+)α-HCH enantiomer was found from krill through penguin, suggesting the enantioselective biotrasformation increased proportionately with trophic level. Polybrominated diphenyl ethers (PBDEs) were measured and their concentrations were 5.6 ± 1.12, 5.81 ± 2.32, 4.57 ± 0.17 and 3.06 ± 3.27 ng/g lipids in krill, rockcod muscle, rockcod homogenate and penguin eggs, respectively. The detection of BDE28, BDE47, BDE99 and BDE100 in Antarctic organisms confirmed their global transport and distribution; the detection of lower brominated congeners suggested a potential long-range transport. - Enantiomeric signature and accumulation of polybrominated diphenyl ethers in the Adelie Penguin food chain are discussed

Magnesium interference and different efficiencies of diastereoisomeric cluster formation in phenylalanine enantiomeric discrimination by the kinetic method

Czech Academy of Sciences Publication Activity Database

Ranc, V.; Havlíček, Vladimír; Bednář, P.; Lemr, Karel

2009-01-01

Roč. 280, 1-3 (2009), s. 213-217 ISSN 1387-3806 R&D Projects: GA MŠk LC07017; GA ČR GA203/07/0765 Grant - others:XE(XE) EC: MKTD-CT-2004-014407 Institutional research plan: CEZ:AV0Z50200510 Keywords : enantiomeric dicrimination * kinetic method * mass spectrometry Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.117, year: 2009

Enantioselective degradation and enantiomerization of indoxacarb in soil.

Science.gov (United States)

Sun, Dali; Pang, Junxiao; Qiu, Jing; Li, Li; Liu, Chenglan; Jiao, Bining

2013-11-27

In this study, the enantioselective degradation and enantiomerizaton of indoxacarb were investigated in two soils under nonsterilized and sterilized conditions using a chiral OD-RH column on a reversed-phase HPLC. Under nonsterilized conditions, the degradation of indoxacarb in two soils was enantioselective. In acidic soil, the half-lives of R-(-)- and S-(+)-indoxacarb were 10.43 and 14.00 days, respectively. Acidic soil was preferential to the degradation of R-(-)-indoxacarb. In alkaline soil, the half-lives of R-(-)- and S-(+)-indoxacarb were 12.14 and 4.88 days, respectively. S-(+)-Indoxacarb was preferentially degraded. Under sterilized conditions, approximately 5-10% of the initial concentration degraded after 75 days of incubation in acidic soil, whereas in alkaline soil, approximately half of the initial concentration degraded due to chemical hydrolysis under alkaline conditions. Enantiomerization was also discovered in acidic and alkaline soils. The results showed that mutual transformation existed between two enantiomers and that S-(+)-indoxacarb had a significantly higher inversion rate to R-(-)-indoxacarb than its antipode.

Synthesis of Enantiomerically Pure 6-Substituted-Piperazine-2-Acetic Acid Esters as Intermediates for Library Production.

Science.gov (United States)

Chamakuri, Srinivas; Jain, Prashi; Guduru, Shiva Krishna Reddy; Arney, Joseph Winston; MacKenzie, Kevin; Santini, Conrad; Young, Damian W

2018-05-11

Amino acids from the chiral pool have been used to produce a 24-member branch of 2,6-disubstituted piperazine scaffolds suitable for use in compound library production. Each scaffold was obtained as a single absolute stereoisomer in multi-gram quantities. Stereochemistry was confirmed by 2D NMR protocols and enantiomeric purity was determined by chiral HPLC. The scaffolds are intended for use as intermediates in parallel synthesis of small-molecule libraries.

Management of specific and excessive posturing behavior in a hyacinth macaw (Anodorhynchus hyacinthinus) by using applied behavior analysis.

Science.gov (United States)

Clayton, Leigh Ann; Friedman, Susan G; Evans, Liz A

2012-06-01

Applied behavior analysis was used in a female hyacinth macaw (Anodorhynchus hyacinthinus) to reduce specific, excessive mating-type posturing that had become disruptive due to increased frequency, duration, and intensity. A functional assessment and intervention design worksheet was used to evaluate behavior-environment relations and to develop an individualized behavior-change plan. The functional assessment indicated that human attention was maintaining the behavior. The intervention, differential reinforcement of incompatible behavior, was implemented to increase attention for standing upright and to remove attention for posturing. Within 1 month, posturing decreased to acceptable levels and was replaced with an upright posture. Problem behaviors that appear "reproductive" may be responsive to behavior management alone. Applied behavior analysis and a functional assessment and intervention design are ideal tools to address problem behavior in avian patients.

Isolation of Notoamide S and Enantiomeric 6-epi-Stephacidin A from the Fungus Aspergillus amoenus: Biogenetic Implications

DEFF Research Database (Denmark)

Kato, Hikaru; Nakahara, Takashi; Sugimoto, Kayo

2015-01-01

Notoamide S has been hypothesized to be a key biosynthetic intermediate for characteristic metabolites stephacidin A, notoamide B, and versicolamide B in Aspergillus sp. but has not yet been isolated. The isolation of notoamide S and an enantiomeric mixture of 6-epi-stephacidin A enriched with th...

Enantiomeric profiling of chiral illicit drugs in a pan-European study

DEFF Research Database (Denmark)

Castrignanò, Erika; Yang, Zhugen; Bade, Richard

2018-01-01

The aim of this paper is to present the first study on spatial and temporal variation in the enantiomeric profile of chiral drugs in eight European cities. Wastewater-based epidemiology (WBE) and enantioselective analysis were combined to evaluate trends in illicit drug use in the context....... High loads of racemic methamphetamine were detected in Oslo (EF = 0.49 ± 0.02). This is in contrast to other European cities where S-(+)-methamphetamine was the predominant enantiomer. This indicates different methods of methamphetamine synthesis and/or trafficking routes in Oslo, compared...... with the other cities tested. An enrichment of MDMA with the R-(−)-enantiomer was observed in European wastewaters indicating MDMA consumption rather than disposal of unused drug. MDA's chiral signature indicated its enrichment with the S-(+)-enantiomer, which confirms its origin from MDMA metabolism in humans...

Study of Substituted Ester Formation in Red Wine by the Development of a New Method for Quantitative Determination and Enantiomeric Separation of Their Corresponding Acids.

Science.gov (United States)

Lytra, Georgia; Franc, Celine; Cameleyre, Margaux; Barbe, Jean-Christophe

2017-06-21

A new method was developed for quantifying substituted acids including, where applicable, their various unexplored enantiomeric forms. A new step was added to acids' usual quantification methods, consisting of extraction, derivatization to methyl esters, and gas chromatography analysis: preliminary extraction was performed at basic pH to eliminate ethyl esters, thus avoiding their transesterification during derivatization. Quantitation and enantiomeric distribution of some substituted esters and their corresponding acids were established in 31 commercial Bordeaux red wines from 0 to 20 years old. A strong positive correlation was observed between the age of wine and levels of ethyl 2-methylpropanoate, ethyl 3-methylbutanoate, ethyl 2-methylbutanoate, ethyl (3R)-3-hydroxybutanoate, both enantiomeric forms of ethyl 2-hydroxy-3-methylbutanoate, and ethyl (2S)-2-hydroxy-4-methylpentanoate, but not ethyl (3S)-3-hydroxybutanoate. However, the standard deviations of average concentrations for the corresponding substituted acids were so large that only few correlations between concentrations and age were observed. Concentrations of (2S)-2-hydroxy-3-methylbutanoic acid and (2S)-2-hydroxy-4-methylpentanoic acid increased slightly over time, while (2R)-2-hydroxy-4-methylpentanoic acid levels decreased slightly with the age. Variations in the ratio of substituted ethyl esters to their corresponding acids over time detected thanks to these analytical advances suggested that, in general, acids were continuously esterified during aging.

Case study of an organic Rankine cycle applied for excess heat recovery: Technical, economic and policy matters

International Nuclear Information System (INIS)

Lemmens, Sanne; Lecompte, Steven

2017-01-01

Highlights: • Case study of an organic Rankine cycle for heat recovery from an industrial kiln. • The costs and financial feasibility of the system are discussed in detail. • The cost structure is most defined by the capital costs, annual costs are limited. • The system is financially feasible, but subsidies remain important. • The results are most sensitive to changes in load hours and electricity price. - Abstract: Many industrial processes inevitably produce excess heat as by-product. Recovering this heat is a matter of waste management and provides opportunities to improve the energy use efficiency. The excess heat can be used for heating purposes (e.g., in processes, or delivered to district heating systems or buildings) or to generate electricity. An increasingly applied technology for industrial excess heat recovery is the organic Rankine cycle (ORC), suitable to recover low-grade heat from 90 °C onwards. Although ORCs are studied intensively, few studies have examined the economics of commissioned ORC systems. This paper investigates a 375 kW_g_r_o_s_s ORC system employed for flue gas heat recovery from an industrial kiln in Flanders, Belgium. The purpose of the study is twofold: providing insight into a practical ORC case; and evaluating the financial feasibility while taking the specific policy circumstances into account. The financial appraisal takes account of the specific technical setup, the diverse costs of the system, the external economic parameters, and the policy circumstances in Europe, Belgium and Flanders. A sensitivity analysis illustrates the influence of each parameter on the results. The analysis demonstrates the dominance of the investment costs (4217 €_2_0_1_3/kW_g_r_o_s_s) in the expenses. Under the valid conditions the investment has a positive financial return, but the financial support from the government is indispensable. Finally, the sensitivity analysis reveals the importance of attaining sufficient load hours and the

Enantiomeric Separation of 1-(Benzofuran-2-yl)alkylamines on Chiral Stationary Phases Based on Chiral Crown Ethers

International Nuclear Information System (INIS)

Park, Soohyun; Kim, Sang Jun; Hyun, Myung Ho

2012-01-01

Optically active chiral amines are important as building blocks for pharmaceuticals and as scaffolds for chiral ligands and, consequently, many efforts have been devoted to the development of efficient methods for their preparation. For example, reduction of amine precursors with chiral catalysts, enzymatic kinetic resolution or dynamic kinetic resolution of racemic amines and the direct amination of ketones with transaminases have been developed as the efficient methods for the preparation of optically active chiral amines. During the process of developing or utilizing optically active chiral amines, the methods for the determination of their enantiomeric composition are essential. Among various methods, liquid chromatographic resolution of enantiomers on chiral stationary phases (CSPs) have been known to be one of the most accurate and economic means for the determination of the enantiomeric composition of optically active chiral compounds. Especially, CSPs based on chiral crown ethers have been successfully used for the resolution of racemic primary amines. For example, CSPs based on (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid (CSP 1, Figure 1) or (3,3'-diphenyl-1,1'-binaphthyl)-20-crown-6 (CSP 2 and CSP 3, Figure 1) have been known to be quite effective for the resolution of cyclic and non-cyclic amines, various fluoroquinolone antibacterials containing a primary amino group, tocainide (antiarrhythmic agent) and its analogues, aryl-a-amino ketones and 3-amino-1,4-benzodiazepin-2-ones

Chiral Analysis of Pesticides and Drugs of Environmental Concern: Biodegradation and Enantiomeric Fraction

Directory of Open Access Journals (Sweden)

Alexandra S. Maia

2017-09-01

Full Text Available The importance of stereochemistry for medicinal chemistry and pharmacology is well recognized and the dissimilar behavior of enantiomers is fully documented. Regarding the environment, the significance is equivalent since enantiomers of chiral organic pollutants can also differ in biodegradation processes and fate, as well as in ecotoxicity. This review comprises designed biodegradation studies of several chiral drugs and pesticides followed by enantioselective analytical methodologies to accurately measure the enantiomeric fraction (EF. The enantioselective monitoring of microcosms and laboratory-scale experiments with different environmental matrices is herein reported. Thus, this review focuses on the importance of evaluating the EF variation during biodegradation studies of chiral pharmaceuticals, drugs of abuse, and agrochemicals and has implications for the understanding of the environmental fate of chiral pollutants.

Reduções enantiosseletivas de cetonas utilizando-se fermento de pão Enantioselective reductions of ketones using baker's yeast

Directory of Open Access Journals (Sweden)

José Augusto R. Rodrigues

2001-12-01

Full Text Available Baker's yeast has been successful employed to reduce carbonyl compounds carrying appropriated substituents at distances under the electronic influence of the keto group. High yields and enantiomeric excess (ee were obtained with 1,2-alkanedione, 1,2-alkanedione (2-O-methyloxime and 1,3-alkanedione. Potential chiral building blocks were obtained and applied for stereoselective synthesis of valuable compounds. Evidence for a free radical chain process was obtained with baker's yeast reduction of a-iodoacetophenone using radical inhibitors.

Quality by design in the chiral separation strategy for the determination of enantiomeric impurities: development of a capillary electrophoresis method based on dual cyclodextrin systems for the analysis of levosulpiride.

Science.gov (United States)

Orlandini, S; Pasquini, B; Del Bubba, M; Pinzauti, S; Furlanetto, S

2015-02-06

Quality by design (QbD) concepts, in accordance with International Conference on Harmonisation Pharmaceutical Development guideline Q8(R2), represent an innovative strategy for the development of analytical methods. In this paper QbD principles have been comprehensively applied in the set-up of a capillary electrophoresis method aimed to quantify enantiomeric impurities. The test compound was the chiral drug substance levosulpiride (S-SUL) and the developed method was intended to be used for routine analysis of the pharmaceutical product. The target of analytical QbD approach is to establish a design space (DS) of critical process parameters (CPPs) where the critical quality attributes (CQAs) of the method have been assured to fulfil the desired requirements with a selected probability. QbD can improve the understanding of the enantioseparation process, including both the electrophoretic behavior of enantiomers and their separation, therefore enabling its control. The CQAs were represented by enantioresolution and analysis time. The scouting phase made it possible to select a separation system made by sulfated-β-cyclodextrin and a neutral cyclodextrin, operating in reverse polarity mode. The type of neutral cyclodextrin was included among other CPPs, both instrumental and related to background electrolyte composition, which were evaluated in a screening phase by an asymmetric screening matrix. Response surface methodology was carried out by a Doehlert design and allowed the contour plots to be drawn, highlighting significant interactions between some of the CPPs. DS was defined by applying Monte-Carlo simulations, and corresponded to the following intervals: sulfated-β-cyclodextrin concentration, 9-12 mM; methyl-β-cyclodextrin concentration, 29-38 mM; Britton-Robinson buffer pH, 3.24-3.50; voltage, 12-14 kV. Robustness of the method was examined by a Plackett-Burman matrix and the obtained results, together with system repeatability data, led to define a method

A method for determining weights for excess relative risk and excess absolute risk when applied in the calculation of lifetime risk of cancer from radiation exposure

Energy Technology Data Exchange (ETDEWEB)

Walsh, Linda [Federal Office for Radiation Protection, Department of Radiation Protection and Health, Oberschleissheim (Germany); University of Manchester, The Faculty of Medical and Human Sciences, Manchester (United Kingdom); Schneider, Uwe [University of Zurich, Vetsuisse Faculty, Zurich (Switzerland); Radiotherapy Hirslanden AG, Aarau (Switzerland)

2013-03-15

Radiation-related risks of cancer can be transported from one population to another population at risk, for the purpose of calculating lifetime risks from radiation exposure. Transfer via excess relative risks (ERR) or excess absolute risks (EAR) or a mixture of both (i.e., from the life span study (LSS) of Japanese atomic bomb survivors) has been done in the past based on qualitative weighting. Consequently, the values of the weights applied and the method of application of the weights (i.e., as additive or geometric weighted means) have varied both between reports produced at different times by the same regulatory body and also between reports produced at similar times by different regulatory bodies. Since the gender and age patterns are often markedly different between EAR and ERR models, it is useful to have an evidence-based method for determining the relative goodness of fit of such models to the data. This paper identifies a method, using Akaike model weights, which could aid expert judgment and be applied to help to achieve consistency of approach and quantitative evidence-based results in future health risk assessments. The results of applying this method to recent LSS cancer incidence models are that the relative EAR weighting by cancer solid cancer site, on a scale of 0-1, is zero for breast and colon, 0.02 for all solid, 0.03 for lung, 0.08 for liver, 0.15 for thyroid, 0.18 for bladder and 0.93 for stomach. The EAR weighting for female breast cancer increases from 0 to 0.3, if a generally observed change in the trend between female age-specific breast cancer incidence rates and attained age, associated with menopause, is accounted for in the EAR model. Application of this method to preferred models from a study of multi-model inference from many models fitted to the LSS leukemia mortality data, results in an EAR weighting of 0. From these results it can be seen that lifetime risk transfer is most highly weighted by EAR only for stomach cancer. However

Improved Syntheses and Expanded Analyses of the Enantiomerically Enriched Chiral Cobalt Complexes Co(en)[subscript 3]I[subscript 3] and Co(diNOsar)Br[subscript 3

Science.gov (United States)

McClellan, Michael J.; Cass, Marion E.

2015-01-01

This communication is a collection of additions and modifications to two previously published classic inorganic synthesis laboratory experiments. The experimental protocol for the synthesis and isolation of enantiomerically enriched ?- (or ?-)Co(en)[subscript 3]I[subscript 3] has been modified to increase reproducibility, yield, and enantiomeric…

Understanding the effect of amino acids based biostimulant by an enantiomeric analysis of their active principles and a proteomic profiling approach

OpenAIRE

Sierras, Núria; Botta-Català, Anna; Staasing, L.; Martínez Esteso, María José; Bru-Martinez, Roque

2016-01-01

Plant biostimulants are products that contain multiple compounds and claim to activate a wide range of plant responses. Amino acid based products are one example of biostimulants with a complex composition and different product characteristics depending on their sources and production processes. Amino acid biostimulants are obtained mainly by chemical or enzymatic protein hydrolysis and the type of hydrolysis determine the content of free amino acids and their enantiomeric purity. While L-ami...

Effect of Excess Gravitational Force on Cultured Myotubes in Vitro

Directory of Open Access Journals (Sweden)

Shigehiro Hashimoto

2013-06-01

Full Text Available An effect of an excess gravitational force on cultured myoblasts has been studied in an experimental system with centrifugal force in vitro. Mouse myoblasts (C2C12 were seeded on a culture dish of 35 mm diameter, and cultured in the Dulbecco's Modified Eagle's Medium until the sub-confluent condition. To apply the excess gravitational force on the cultured cells, the dish was set in a conventional centrifugal machine. Constant gravitational force was applied to the cultured cells for three hours. Variations were made on the gravitational force (6 G, 10 G, 100 G, 500 G, and 800 G with control of the rotational speed of the rotator in the centrifugal machine. Morphology of the cells was observed with a phasecontrast microscope for eight days. The experimental results show that the myotube thickens day by day after the exposure to the excess gravitational force field. The results also show that the higher excess gravitational force thickens myotubes. The microscopic study shows that myotubes thicken with fusion each other.

A concise summary of experimental facts about the Soai reaction.

Science.gov (United States)

Gehring, Timo; Busch, Mark; Schlageter, Martin; Weingand, Daniel

2010-01-01

The Soai reaction amplifies small enantiomeric excesses in a spectacular manner. Being known for 20 years, it has drawn the attention of many scientists in different fields as it is to date the only chemical reaction offering the chance to study the phenomenon of asymmetric autocatalysis in conjunction with high amplification of enantiomeric excess (ee). This mini-review comprises an introduction to the discovery of asymmetric autocatalysis with amplification of ee and a concise summary of published experimental results showing which starting materials and reaction parameters play an important role in this reaction and which influences are understood. It is addressed especially to scientists entering the field of the Soai reaction to get a quick overview of important aspects. © 2010 Wiley-Liss, Inc.

Composition and Enantiomeric Analysis of the Essential Oil of the Fruits and the Leaves of Pistacia vera from Greece

OpenAIRE

Anastasia Tsokou; Katerina Georgopoulou; Eleni Melliou; Prokopios Magiatis; Eugenia Tsitsa

2007-01-01

The essential oils of the fruits and the leaves of pistachio (Pistacia vera L.) were analyzed by GC and GC/MS. Fresh unripe pistachio fruits were richer in essential oil (0.5 %, w/w) than the leaves (0.1 %, w/w). Twenty one compounds were identified in the essential oil of the fruits and the major components were (+)-α-pinene (54.6 %) and terpinolene (31.2 %). The enantiomeric ratio of the major constituents of the essential oil of the fruits was determined using chiral GC/MS and it was fo...

The resolution of acyclic P-stereogenic phosphine oxides via the formation of diastereomeric complexes: A case study on ethyl-(2-methylphenyl)-phenylphosphine oxide.

Science.gov (United States)

Bagi, Péter; Varga, Bence; Szilágyi, András; Karaghiosoff, Konstantin; Czugler, Mátyás; Fogassy, Elemér; Keglevich, György

2018-04-01

As an example of acyclic P-chiral phosphine oxides, the resolution of ethyl-(2-methylphenyl)-phenylphosphine oxide was elaborated with TADDOL derivatives, or with calcium salts of the tartaric acid derivatives. Besides the study on the resolving agents, several purification methods were developed in order to prepare enantiopure ethyl-(2-methylphenyl)-phenylphosphine oxide. It was found that the title phosphine oxide is a racemic crystal-forming compound, and the recrystallization of the enantiomeric mixtures could be used for the preparation of pure enantiomers. According to our best method, the (R)-ethyl-(2-methylphenyl)-phenylphosphine oxide could be obtained with an enantiomeric excess of 99% and in a yield of 47%. Complete racemization of the enantiomerically enriched phosphine oxide could be accomplished via the formation of a chlorophosphonium salt. Characterization of the crystal structures of the enantiopure phosphine oxide was complemented with that of the diastereomeric intermediate. X-ray analysis revealed the main nonbonding interactions responsible for enantiomeric recognition. © 2018 Wiley Periodicals, Inc.

Helix-helix inversion of an optically-inactive π-conjugated foldamer triggered by concentration changes of a single enantiomeric guest leading to a change in the helical stability.

Science.gov (United States)

Liu, Lijia; Ousaka, Naoki; Horie, Miki; Mamiya, Fumihiko; Yashima, Eiji

2016-09-27

A preferred-handed helicity induced in an optically-inactive poly(phenyleneethynylene)-based foldamer bearing carboxylic acid pendants upon complexation with a single enantiomeric diamine was subsequently inverted into the opposite helix upon further addition of the diamine, accompanied by a remarkable change in the stability of the helices.

Robotized synthesis of [3-11C]-L-alanine using reaction of asymmetric alkylation of 11CH3I nickel complex of glycine Schiff base with S-2-N-(N'-benzylpropyl)aminobenzophenone

International Nuclear Information System (INIS)

Mosevich, I.K.; Kuznetsova, O.F.; Vasil'ev, D.A.; Anichkov, A.A.; Korsakov, M.V.

1999-01-01

Synthesis of [3- 11 C]-L-alanine based on 11 CH 3 I nickel complex (1) alkylation using different solvents (tetrahydrofuran, dimethylformamide, acetonitrile, acetone) and catalysts (potassium butylate, sodium hydride) was investigated. It was shown that synthesis of amino acids labelled with 11 C based on complex (1) use permits to obtain preparations with high degree of enantiomeric enrichment. The best results (enantiomeric excess of L-alanine up to 99 %) were obtained in reaction with acetonitrile as a solvent and potassium tret-butylate as a catalyst

The "racemic approach" in the evaluation of the enantiomeric NorA efflux pump inhibition activity of 2-phenylquinoline derivatives.

Science.gov (United States)

Carotti, Andrea; Ianni, Federica; Sabatini, Stefano; Di Michele, Alessandro; Sardella, Roccaldo; Kaatz, Glenn W; Lindner, Wolfgang; Cecchetti, Violetta; Natalini, Benedetto

2016-09-10

Among the mechanisms adopted by bacteria, efflux pumps (EPs) have been recognized as being significantly involved in contributing to resistance to commonly used antibacterial agents. However, little is known about their three-dimensional structures or the steric requirements for their inhibition. Lack of such knowledge includes NorA, one of the most studied Staphylococcus aureus EPs. In the present study, the use of two commercialized Cinchona alkaloid-based zwitterionic chiral stationary phases allowed the enantioseparation of four 2-((2-(4-propoxyphenyl)quinolin-4-yl)oxy)alkylamines 1-4 previously found to be potent S. aureus NorA efflux pump inhibitors when tested as racemates. In the identified optimal polar-ionic conditions (MeOH/THF/H2O-49/49/2 (v/v/v)+25mM formic acid, 12.5mM diethylamine), repeated consecutive injections of 1 allowed the isolation of sufficient amount of its enantiomers (2.6mg and 2.8mg, for (R)-1 and (S)-1, respectively) and then to evaluate their ability to inhibit the S. aureus NorA efflux pump. The biological evaluation highlighted the main contribution of the (R)-1 enantiomer to both the EtBr efflux inhibition and synergistic effect with against SA-1199B (norA+/A116E GrlA) respect to the racemate activity. The comparison between the experimental electronic circular dichroism and the time-dependent density functional theory calculations spectra of the two isolated enantiomeric fractions allowed for all compounds a clear and easy assignment of the enantiomeric elution order. Copyright © 2016 Elsevier B.V. All rights reserved.

Selection of Amino Acid Chirality via Neutrino Interactions with 14N in Crossed Electric and Magnetic Fields

Science.gov (United States)

Boyd, Richard N.; Kajino, Toshitaka; Onaka, Takashi

2018-01-01

Abstract Previous work has suggested that the chirality of the amino acids could be established in the magnetic field of a nascent neutron star from a core-collapse supernova or massive collapsar. The magnetic field would orient the 14N nuclei, and the alignment of its nuclear spin with respect to those of the electron antineutrinos emitted from the collapsing star would determine the probability of destruction of the 14N nuclei by interactions with the antineutrinos. Subsequent work estimated the bulk polarization of the 14N nuclei in large rotating meteoroids in such an environment. The present work adds a crucial piece of this model by describing the details by which the selective 14N nuclear destruction would produce molecular chiral selectivity. The effects of the neutrino-induced interactions on the 14N nuclei bound in amino acids polarized in strong magnetic fields are studied. It is shown that electric fields in the reference frame of the nuclei modify the magnetic field at the nucleus, creating nuclear magnetizations that are asymmetric in chirality. The antineutrino cross sections depend on this magnetization, creating a selective destructive effect. The environmental conditions and sites in which such a selection mechanism could occur are discussed. Selective destruction of D-enantiomers results in enantiomeric excesses which may be sufficient to drive subsequent autocatalysis necessary to produce the few-percent enantiomeric excesses found in meteorites and subsequent homochirality. Molecular quantum chemical calculations were performed for alanine, and the chirality-dependent effects studied were included. A preference for left-handed molecules was found, and enantiomeric excesses as high as 0.02% were estimated for molecules in the electromagnetic conditions expected from a core-collapse supernova. Key Words: Amino acids—Supernovae—Antineutrinos—Enantiomeric excess—Chirality. Astrobiology 18, 190–206. PMID:29160728

One pot 'click' reactions : tandem enantioselective biocatalytic epoxide ring opening and [3+2] azide alkyne cycloaddition

NARCIS (Netherlands)

Campbell-Verduyn, Lachlan S.; Szymanski, Wiktor; Postema, Christiaan P.; Dierckx, Rudi A.; Elsinga, Philip H.; Janssen, Dick B.; Feringa, Ben L.

2010-01-01

Halohydrin dehalogenase (HheC) can perform enantioselective azidolysis of aromatic epoxides to 1,2-azido alcohols which are subsequently ligated to alkynes producing chiral hydroxy triazoles in a one-pot procedure with excellent enantiomeric excess.

Experimental and Model Studies on Continuous Separation of 2-Phenylpropionic Acid Enantiomers by Enantioselective Liquid-Liquid Extraction in Centrifugal Contactor Separators.

Science.gov (United States)

Feng, Xiaofeng; Tang, Kewen; Zhang, Pangliang; Yin, Shuangfeng

2016-03-01

Multistage enantioselective liquid-liquid extraction (ELLE) of 2-phenylpropionic acid (2-PPA) enantiomers using hydroxypropyl-β-cyclodextrin (HP-β-CD) as extractant was studied experimentally in a counter-current cascade of centrifugal contactor separators (CCSs). Performance of the process was evaluated by purity (enantiomeric excess, ee) and yield (Y). A multistage equilibrium model was established on the basis of single-stage model for chiral extraction of 2-PPA enantiomers and the law of mass conservation. A series of experiments on the extract phase/washing phase ratio (W/O ratio), extractant concentration, the pH value of aqueous phase, and the number of stages was conducted to verify the multistage equilibrium model. It was found that model predictions were in good agreement with the experimental results. The model was applied to predict and optimize the symmetrical separation of 2-PPA enantiomers. The optimal conditions for symmetric separation involves a W/O ratio of 0.6, pH of 2.5, and HP-β-CD concentration of 0.1 mol L(-1) at a temperature of 278 K, where eeeq (equal enantiomeric excess) can reach up to 37% and Yeq (equal yield) to 69%. By simulation and optimization, the minimum number of stages was evaluated at 98 and 106 for eeeq > 95% and eeeq > 97%. © 2016 Wiley Periodicals, Inc.

Asymmetric Meerwein–Ponndorf–Verley reduction of long chain keto alkanoic acid methyl esters

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AYE YUSUFOGLU

2007-05-01

Full Text Available 3-, 7- and 13-Monoketo tetradecanoic acid methyl esters carrying a ketogroup at the ends and at the middle of the chain with 14 carbon atoms were reduced by a Meerwein–Ponndorf–Verley reaction in the presence of R-(+-1,1'-binaphthalene-2,2'-diol, 1,2:5,6-D-di-O-isopropylidene-D-mannitol and L-(–-menthol. The highest enantiomeric purity of 65% ee was found for 13-hydroxy ester isomer. The enantiomeric excess was determined by 1H-NMR shift with Eu(tfc3 and by optical rotation.

Tandem Rh-Catalyzed Oxidative C-H Olefination and Cyclization of Enantiomerically Enriched Benzo-1,3-Sulfamidates: Stereoselective Synthesis of trans-1,3-Disubstituted Isoindolines.

Science.gov (United States)

Achary, Raghavendra; Jung, In-A; Lee, Hyeon-Kyu

2018-04-06

A tandem process, involving Rh(III)-catalyzed oxidative C-H olefination of enantiomerically enriched 4-aryl-benzo-1,3-sulfamidates and subsequent intramolecular aza-Michael cyclization has been developed. The reaction produces trans-benzosulfamidate-fused-1,3-disubstituted isoindolines as major products, in which the configurational integrity of the stereogenic center in the starting material is preserved. Further transformations of the benzosulfamidate-fused-1,3-disubstituted isoindolines are described.

Optimisation of stabilised carboxylesterase NP for enantioselective hydrolysis of naproxen methyl ester

CSIR Research Space (South Africa)

Steenkamp, Lucia H

2008-12-01

Full Text Available Although the enantioselective kinetic resolution of ester racemates of the non-steroidal antiinflammatory drug naproxen ([2-(6-methoxy-2-naphthyl) propionic acid]) is a common demonstration for biocatalysis, the enantiomeric excess of the reactions...

Enantiomeric switching of chiral metamaterial for terahertz polarization modulation employing vertically deformable MEMS spirals

Science.gov (United States)

Kan, Tetsuo; Isozaki, Akihiro; Kanda, Natsuki; Nemoto, Natsuki; Konishi, Kuniaki; Takahashi, Hidetoshi; Kuwata-Gonokami, Makoto; Matsumoto, Kiyoshi; Shimoyama, Isao

2015-10-01

Active modulation of the polarization states of terahertz light is indispensable for polarization-sensitive spectroscopy, having important applications such as non-contact Hall measurements, vibrational circular dichroism measurements and anisotropy imaging. In the terahertz region, the lack of a polarization modulator similar to a photoelastic modulator in the visible range hampers expansion of such spectroscopy. A terahertz chiral metamaterial has a huge optical activity unavailable in nature; nevertheless, its modulation is still challenging. Here we demonstrate a handedness-switchable chiral metamaterial for polarization modulation employing vertically deformable Micro Electro Mechanical Systems. Vertical deformation of a planar spiral by a pneumatic force creates a three-dimensional spiral. Enantiomeric switching is realized by selecting the deformation direction, where the polarity of the optical activity is altered while maintaining the spectral shape. A polarization rotation as high as 28° is experimentally observed, thus providing a practical and compact polarization modulator for the terahertz range.

Chiral separation of a diketopiperazine pheromone from marine diatoms using supercritical fluid chromatography.

Science.gov (United States)

Frenkel, Johannes; Wess, Carsten; Vyverman, Wim; Pohnert, Georg

2014-03-01

The proline derived diketopiperazine has been identified in plants, insects and fungi with unknown function and was recently also reported as the first pheromone from a diatom. Nevertheless the stereochemistry and enantiomeric excess of this natural product remained inaccessible using direct analytical methods. Here we introduce a chiral separation of this metabolite using supercritical fluid chromatography/mass spectrometry. Several chromatographic methods for chiral analysis of the diketopiperazine from the diatom Seminavis robusta and synthetic enantiomers have been evaluated but neither gas chromatography nor high performance liquid chromatography on different chiral cyclodextrin phases were successful in separating the enantiomers. In contrast, supercritical fluid chromatography achieved baseline separation within four minutes of run time using amylose tris(3,5-dimethylphenylcarbamate) as stationary phase and 2-propanol/CO2 as mobile phase. This very rapid chromatographic method in combination with ESI mass spectrometry allowed the direct analysis of the cyclic dipeptide out of the complex sea water matrix after SPE enrichment. The method could be used to determine the enantiomeric excess of freshly released pheromone and to follow the rapid degradation observed in diatom cultures. Initially only trace amounts of c(d-Pro-d-Pro) were found besides the dominant c(l-Pro-l-Pro) in the medium. However the enantiomeric excess decreased upon pheromone degradation within few hours indicating that a preferential conversion and thus inactivation of the l-proline derived natural product takes place. Copyright © 2014 Elsevier B.V. All rights reserved.

Enantiomeric fraction and isomeric composition to assess sources of DDT residues in soils.

Science.gov (United States)

Bosch, Carme; Grimalt, Joan O; Fernández, Pilar

2015-11-01

Chiral pesticides such as o,p'-DDT can undergo enantioselective microbial degradation in soil. Hence, the enantiomeric fraction (EF) of o,p'-DDT was used as an approach to assess potential recent inputs of DDT in the lower part of the Ebro River basin (NE Spain), a region heavily impacted by agricultural and industrial activities, including a dicofol production and a chloro-alkali plants. The EFs of five out of nineteen soils were not different from the racemic value (0.505±0.010), confirming that the Ebro River and some of its tributaries, Segre and Cinca rivers, transported fresh DDT residues despite its ban in Spain during the 90 s. o,p'-DDT/p,p'-DDT ratios in soils suggest that recent use of technical DDT and/or DDT-contaminated dicofol may be responsible for the fresh DDT inputs in the Segre River, while in the Ebro River, they indicate a dominant contribution of technical DDT, likely related to the residues accumulated by the chloro-alkali plant discharges. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biotransformations of Substituted Phenylethanols and Acetophenones by Environmental Bacteria

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Edna Kagohara

2008-01-01

Full Text Available Whole cells of hydrocarbon-degrading bacteria, isolated from polluted sediments in the Santos Estuary (Baixada Santista, São Paulo, Brazil, were able to catalyse oxidoreduction reactions with various substituted phenylethanols and acetophenones as substrates. A number of substituted phenylethanols were formed with high (>99 % enantiomeric excess. The results of microbial oxidation of phenylethanols 2, 3, 5–7 by Acinetobacter sp. 6.4T and the reduction of acetophenones 1a–6a by Serratia marcescens 5.4T showed that the bacteria used as biocatalysts in this study present significant potential for exploitation in biotechnological processes. The reduction of prochiral acetophenones by Serratia marcescens 3.5T yielded optically active alcohols with 90–99 % enantiomeric excess, and Acinetobacter sp. 6.4T is a potential biocatalyst for the oxidation of alcohols.

Highly Enantioselective Production of (R-Halohydrins with Whole Cells of Rhodotorula rubra KCh 82 Culture

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Tomasz Janeczko

2014-12-01

Full Text Available Biotransformation of ten α-haloacetophenones in the growing culture of the strain Rhodotorula rubra KCh 82 has been carried out. Nine of the substrates underwent an effective enantioselective reduction to the respective (R-alcohols according to Prelog’s rule, with the exception of 2-chloro-1,2-diphenylethan-1-one that was not transformed by this strain. The expected reduction proceeded without dehalogenation, leading to the respective (R-halohydrins in high yields. The use of this biocatalyst yielded (R-2-bromo-1-phenyl-ethan-1-ol (enantiomeric excess (ee = 97% and its derivatives: 4'-Bromo- (ee = 99%; 4'-Chloro- (ee > 99%; 4'-Methoxy- (ee = 96%; 3'-Methoxy- (ee = 93%; 2'-Methoxy- (ee = 98%. There were also obtained and characterized 2,4'-dichloro-, 2,2',4'-trichloro- and 2-chloro-4'-fluoro-phenyetan-1-ol with >99% of enantiomeric excesses.

Highly enantioselective production of (R)-halohydrins with whole cells of Rhodotorula rubra KCh 82 culture.

Science.gov (United States)

Janeczko, Tomasz; Dymarska, Monika; Kostrzewa-Susłow, Edyta

2014-12-04

Biotransformation of ten α-haloacetophenones in the growing culture of the strain Rhodotorula rubra KCh 82 has been carried out. Nine of the substrates underwent an effective enantioselective reduction to the respective (R)-alcohols according to Prelog's rule, with the exception of 2-chloro-1,2-diphenylethan-1-one that was not transformed by this strain. The expected reduction proceeded without dehalogenation, leading to the respective (R)-halohydrins in high yields. The use of this biocatalyst yielded (R)-2-bromo-1-phenyl-ethan-1-ol (enantiomeric excess (ee) = 97%) and its derivatives: 4'-Bromo- (ee = 99%); 4'-Chloro- (ee > 99%); 4'-Methoxy- (ee = 96%); 3'-Methoxy- (ee = 93%); 2'-Methoxy- (ee = 98%). There were also obtained and characterized 2,4'-dichloro-, 2,2',4'-trichloro- and 2-chloro-4'-fluoro-phenyetan-1-ol with >99% of enantiomeric excesses.

A new and expeditious synthesis of all enantiomerically pure stereoisomers of rosaprostol, an antiulcer drug

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Wiesława Perlikowska

2016-10-01

Full Text Available Four enantiomerically pure stereoisomers of rosaprostol (1, an antiulcer drug, were efficiently synthesized from the enantiomers of 2-(dimethoxyphosphoryl-3-hexylcyclopentanone (3 as chiral substrates. The latter were obtained by resolution of racemic 3 with (+-(R-1-(1-naphthylethylamine. The conversion of (+-3 into rosaprostol stereoisomer (−-1a was accomplished in four steps in 56% overall yield. According to the same protocol, the second stereoisomer (+-1c was obtained from (−-3 in 55% overall yield. A slightly improved procedure of the last two steps of the transformation of (+-3 into (−-1a allowed an increase in the overall yield to 64%. The remaining two stereoisomers, (−-1b and (+-1d, were obtained from (−-1a and (+-1c in 71 and 68% yield, respectively, by a two-reaction sequence, in which a Mitsunobu inversion of configuration at C-5 was the key step.

Excessive Daytime Sleepiness

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Yavuz Selvi

2016-06-01

Full Text Available Excessive daytime sleepiness is one of the most common sleep-related patient symptoms, with preva-lence in the community estimated to be as high as 18%. Patients with excessive daytime sleepiness may exhibit life threatening road and work accidents, social maladjustment, decreased academic and occupational performance and have poorer health than comparable adults. Thus, excessive daytime sleepiness is a serious condition that requires investigation, diagnosis and treatment primarily. As with most medical condition, evaluation of excessive daytime sleepiness begins a precise history and various objective and subjective tools have been also developed to assess excessive daytime sleepiness. The most common causes of excessive daytime sleepiness are insufficient sleep hygiene, chronic sleep deprivation, medical and psychiatric conditions and sleep disorders, such as obstructive sleep apnea, medications, and narcolepsy. Treatment option should address underlying contributors and promote sleep quantity by ensuring good sleep hygiene. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2016; 8(2: 114-132

Relevance and bio-catalytic strategies for the kinetic resolution of ketoprofen towards dexketoprofen.

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Toledo, María Victoria; Briand, Laura Estefanía

2017-11-10

This review presents the most relevant investigations concerning the biocatalytic kinetic resolution of racemic ketoprofen to dexketoprofen for the last 22 years. The advantages related to the administration of the dex-enantiomer in terms of human health, the so called "chiral switch" in the pharmaceutical industry and the sustainability of biotransformations have been the driving forces to develop innovative technology to obtain dexketoprofen. In particular, the kinetic resolution of racemic ketoprofen through enantiomeric esterification and hydrolysis using lipases as biocatalysts are thoroughly revised and commented upon. In this context, the biocatalysts, acyl-acceptors (alcohols), reaction conditions, conversion, enantiomeric excess, and enantiomeric ratio among others are discussed. Moreover, the investigations concerning scaling up processes in order to obtain an optically pure enantiomer of the profen are presented. Finally, some guidelines about perspectives of the technology and research opportunities are given.

One-pot synthesis of enantiomerically pure N-protected allylic amines from N-protected α-amino esters

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Gastón Silveira-Dorta

2016-05-01

Full Text Available An improved protocol for the synthesis of enantiomerically pure allylic amines is reported. N-Protected α-amino esters derived from natural amino acids were submitted to a one-pot tandem reduction–olefination process. The sequential reduction with DIBAL-H at −78 °C and subsequent in situ addition of organophosphorus reagents yielded the corresponding allylic amines without the need to isolate the intermediate aldehyde. This circumvents the problem of instability of the aldehydes. The method tolerates well both Wittig and Horner–Wadsworth–Emmons organophosphorus reagents. A better Z-(diastereoselectivity was observed when compared to the previous one-pot method. The (diastereoselectivity of the process was affected neither by the reaction solvent nor by the amount of DIBAL-H employed. The method is compatible with the presence of free hydroxy groups as shown with serine and threonine derivatives.

Simultaneous enantioselective separation of polychlorinated biphenyls and their methyl sulfone metabolites by heart-cut MDGC: determination of enantiomeric fractions in fish oils and cow liver samples.

Science.gov (United States)

Pérez-Fernández, Virginia; Castro-Puyana, María; González, María José; Marina, María Luisa; García, María Ángeles; Gómara, Belén

2012-07-01

The potential of three capillary columns based on β-cyclodextrin (i.e., Chirasil-Dex, BGB-172, and BGB-176SE) has been studied for the simultaneous enantiomeric separation of polychlorinated biphenyls (PCBs) and methylsulfonyl metabolites of PCBs (MeSO(2)-PCBs) employing a heart-cut multidimensional gas chromatographic system (heart-cut MDGC). Among the columns studied, the BGB-176SE capillary column provided the best results, allowing the simultaneous enantioselective resolution of six MeSO(2)-PCBs and six chiral PCBs; the Chirasil-Dex column did not resolve any of the studied MeSO(2)-PCBs; and a poor resolution was obtained for three MeSO(2)-PCBs when the BGB-172 column was employed. The developed method was successfully applied to two fish oil and one cow liver samples commercially available, which showed different enantioselective pattern. PCBs 91 and 176 presented a clear enrichment of the second eluted atropisomer in codfish oil, whereas in fish oil sample, slight enrichment of the first eluted atropisomer of CB45 and the second eluted atropisomer of CB136 were observed. © 2012 Wiley Periodicals, Inc.

A novel approach to predict the excess volume of hydrocarbon mixtures

NARCIS (Netherlands)

Finkers, H. J.; Bosma, J. C.; Broekhuis, A. A.

2011-01-01

This paper explores whether principles obtained for the packing of solid macroscopic particles can be applied to the study of excess volumes of liquid mixtures. The approach is applied to mixtures of 'pure' hydrocarbons, i.e. containing only C- and H-atoms. In this new approach a set of equations

How parents can affect excessive spending of time on screen-based activities.

Science.gov (United States)

Brindova, Daniela; Pavelka, Jan; Ševčikova, Anna; Žežula, Ivan; van Dijk, Jitse P; Reijneveld, Sijmen A; Geckova, Andrea Madarasova

2014-12-12

The aim of this study is to explore the association between family-related factors and excessive time spent on screen-based activities among school-aged children. A cross-sectional survey using the methodology of the Health Behaviour in School-aged Children study was performed in 2013, with data collected from Slovak (n = 258) and Czech (n = 406) 11- and 15-year-old children. The effects of age, gender, availability of a TV or computer in the bedroom, parental rules on time spent watching TV or working on a computer, parental rules on the content of TV programmes and computer work and watching TV together with parents on excessive time spent with screen-based activities were explored using logistic regression models. Two-thirds of respondents watch TV or play computer games at least two hours a day. Older children have a 1.80-times higher chance of excessive TV watching (CI: 1.30-2.51) and a 3.91-times higher chance of excessive computer use (CI: 2.82-5.43) in comparison with younger children. More than half of children have a TV (53%) and a computer (73%) available in their bedroom, which increases the chance of excessive TV watching by 1.59 times (CI: 1.17-2.16) and of computer use by 2.25 times (CI: 1.59-3.20). More than half of parents rarely or never apply rules on the length of TV watching (64%) or time spent on computer work (56%), and their children have a 1.76-times higher chance of excessive TV watching (CI: 1.26-2.46) and a 1.50-times greater chance of excessive computer use (CI: 1.07-2.08). A quarter of children reported that they are used to watching TV together with their parents every day, and these have a 1.84-times higher chance of excessive TV watching (1.25-2.70). Reducing time spent watching TV by applying parental rules or a parental role model might help prevent excessive time spent on screen-based activities.

Controlling the amplification of chirality in hydrogen-bonded assemblies

NARCIS (Netherlands)

Mateos timoneda, Miguel; Crego Calama, Mercedes; Reinhoudt, David

2005-01-01

The amplification of chirality (a high enantiomeric or diastereomeric excess induced by a small initial amount of chiral bias) on hydrogen-bonded assemblies has been studied using “sergeants-and-soldiers” experiments under thermodynamically controlled conditions. Here it is shown that different

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Asymmetric alkyl substitution of various benzophenone Schiff base substrates under biphasic conditions proceeded using optically active Palladium(II) complexes. The corresponding products were obtained in high yields but with moderate enantiomeric excess (ee). Addition of specific ionic liquids to the reaction medium ...

A new enantioselective CE method for determination of oxcarbazepine and licarbazepine after fungal biotransformation.

Science.gov (United States)

Bocato, Mariana Zuccherato; Bortoleto, Marcela Armelim; Pupo, Mônica Tallarico; de Oliveira, Anderson Rodrigo Moraes

2014-10-01

The present work describes, for the first time, the simultaneous separation of oxcarbazepine (OXC) and its active metabolite 10-hydroxy-10,11-dihydrocarbamazepine (licarbazepine, Lic) by chiral CE. The developed method was employed to monitor the enantioselective biotransformation of OXC into its active metabolite by fungi. The electrophoretic separations were performed using 10 mmol/L of a Tris-phosphate buffer solution (pH 2.5) containing 1% w/v of β-CD phosphate sodium salt (P-β-CD) as running electrolyte, -20 kV of applied voltage and a 15°C capillary temperature. The method was linear over the concentration range of 1000-30 000 ng/mL for OXC and 75-900 ng/mL for each Lic enantiomer (r ≥ 0.9952). Within-day precision and accuracy evaluated by RSD and relative errors, respectively, were lower than 15% for all analytes. The validated method was used to evaluate the enantioselective biotransformation of OXC, mediated by fungi, into its active metabolite Lic. This study showed that the fungi Glomerella cingulata (VA1) and Beuveria bassiana were able to enantioselectively metabolize the OXC into Lic after 360 h of incubation. Biotransformation by the fungus Beuveria bassiana showed 79% enantiomeric excess for (S)-(+)-Lic, while VA1 gave an enantiomeric excess of 100% for (S)-(+)-Lic. This study opens a new route to the drug (S)-(+)-licarbazepine. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enrichment of the Amino Acid L-Isovaline by Aqueous Alteration on CI and CM Meteorite Parent Bodies

Science.gov (United States)

Glavin, Daniel P.; Dworkin, Jason P.

2009-01-01

The distribution and enantiomeric composition of the 5-carbon (C(sub 5)) amino acids found in Cl-, CM-, and CR-type carbonaceous meteorites were investigated by using liquid chromatography fluorescence detection/TOF-MS coupled with o-phthaldialdehyde/Nacetyl- l-cysteine derivatization. A large L-enantiomeric excess (ee) of the a-methyl amino acid isovaline was found in the CM meteorite Murchison (L(sub ee) = 18.5 +/- 2.6%) and the Cl meteorite Orguell (L(sub ee) = 15.2 +/- 4.0%). The measured value for Murchison is the largest enantiomeric excess in any meteorite reported to date, and the Orgueil measurement of an isovaline excess has not been reported previously for this or any Cl meteorite. The L-isovaline enrichments in these two carbonaceous meteorites cannot be the result of interference from other C(sub 5) amino acid isomers present in the samples, analytical biases, or terrestrial amino acid contamination. We observed no L-isovaline enrichment for the most primitive unaltered Antarctic CR meteorites EET 92042 and QUE 99177. These results are inconsistent with UV circularly polarized light as the primary mechanism for L-isovaline enrichment and indicate that amplification of a small initial isovaline asymmetry in Murchison and Orgueil occurred during an extended aqueous alteration phase on the meteorite parent bodies. The large asymmetry in isovaline and other alpha-dialkyl amino acids found in altered Ct and CM meteorites suggests that amino acids delivered by asteroids, comets, and their fragments would have biased the Earth's prebiotic organic inventory with left-handed molecules before the origin of life.

Thiol and Disulfide Derivatives of Ephedra Alkaloids 2 : A Mechanistic Study of Their Effect on the Addition of Diethyl Zinc to Benzaldehyde

NARCIS (Netherlands)

Fitzpatrick, Kevin; Hulst, Ron; Kellogg, Richard M.

Thiol and disulfide derivatives of ephedrine have been shown previously to catalyse in high enantiomeric excess (ee) the reaction of diethyl zinc with benzaldehyde. We find that this reaction involves non-linear correlations between the ee of product and catalyst. Osmotic measurements indicate a

EXCESSIVE INTERNET USE AND PSYCHOPATHOLOGY: THE ROLE OF COPING

Directory of Open Access Journals (Sweden)

Daria J. Kuss

2017-02-01

Full Text Available Objective: In 2013, the American Psychiatric Association included Internet Gaming Disorder in the diagnostic manual as a condition which requires further research, indicating the scientific and clinical community are aware of potential health concerns as a consequence of excessive Internet use. From a clinical point of view, it appears that excessive/addictive Internet use is often comorbid with further psychopathologies and assessing comorbidity is relevant in clinical practice, treatment outcome and prevention as the probability to become addicted to using the Internet accelerates with additional (subclinical symptoms. Moreover, research indicates individuals play computer games excessively to cope with everyday stressors and to regulate their emotions by applying media-focused coping strategies, suggesting pathological computer game players play in order to relieve stress and to avoid daily hassles. The aims of this research were to replicate and extend previous findings and explanations of the complexities of the relationships between excessive Internet use and Internet addiction, psychopathology and dysfunctional coping strategies. Method: Participants included 681 Polish university students sampled using an online battery of validated psychometric instruments. Results: Results of structural equation models revealed dysfunctional coping strategies (i.e., distraction, denial, self-blame, substance use, venting, media use, and behavioural disengagement significantly predict excessive Internet use, and the data fit the theoretical model well. A second SEM showed media-focused coping and substance use coping significantly mediate the relationship between psychopathology (operationalised via the Global Severity Index and excessive Internet use. Conclusions: The findings lend support to the self-medication hypothesis of addictive disorders, and suggest psychopathology and dysfunctional coping have additive effects on excessive Internet use.

Meteoritic Amino Acids: Diversity in Compositions Reflects Parent Body Histories

Science.gov (United States)

Elsila, Jamie E.; Aponte, Jose C.; Blackmond, Donna G.; Burton, Aaron S.; Dworkin, Jason P.; Glavin, Daniel P.

2016-01-01

The analysis of amino acids in meteorites dates back over 50 years; however, it is only in recent years that research has expanded beyond investigations of a narrow set of meteorite groups (exemplied by the Murchison meteorite) into meteorites of other types and classes. These new studies have shown a wide diversity in the abundance and distribution of amino acids across carbonaceous chondrite groups, highlighting the role of parent body processes and composition in the creation, preservation, or alteration of amino acids. Although most chiral amino acids are racemic in meteorites, the enantiomeric distribution of some amino acids, particularly of the nonprotein amino acid isovaline, has also been shown to vary both within certain meteorites and across carbonaceous meteorite groups. Large -enantiomeric excesses of some extraterrestrial protein amino acids (up to 60) have also been observed in rare cases and point to nonbiological enantiomeric enrichment processes prior to the emergence of life. In this Outlook, we review these recent meteoritic analyses, focusing on variations in abundance, structural distributions, and enantiomeric distributions of amino acids and discussing possible explanations for these observations and the potential for future work.

Excessive Internet gaming and decision making: do excessive World of Warcraft players have problems in decision making under risky conditions?

Science.gov (United States)

Pawlikowski, Mirko; Brand, Matthias

2011-08-15

The dysfunctional behavior of excessive Internet gamers, such as preferring the immediate reward (to play World of Warcraft) despite the negative long-term consequences may be comparable with the dysfunctional behavior in substance abusers or individuals with behavioral addictions, e.g. pathological gambling. In these disorders, general decision-making deficits have been demonstrated. Hence, the aim of the present work was to examine decision-making competences of excessive World of Warcraft players. Nineteen excessive Internet gamers (EIG) and a control group (CG) consisting of 19 non-gamers were compared with respect to decision-making abilities. The Game of Dice Task (GDT) was applied to measure decision-making under risky conditions. Furthermore psychological-psychiatric symptoms were assessed in both groups. The EIG showed a reduced decision-making ability in the GDT. Furthermore the EIG group showed a higher psychological-psychiatric symptomatology in contrast to the CG. The results indicate that the reduced decision-making ability of EIG is comparable with patients with other forms of behavioral addiction (e.g. pathological gambling), impulse control disorders or substance abusers. Thus, these results suggest that excessive Internet gaming may be based on a myopia for the future, meaning that EIG prefer to play World of Warcraft despite the negative long-term consequences in social or work domains of life. 2011 Elsevier Ltd. All rights reserved.

Anestesia peridural para cesariana: estudo comparativo entre Bupivacaína Racêmica (S50-R50 e Bupivacaína com excesso enantiomérico de 50% (S75-R25 a 0,5% associadas ao Sufentanil Anestesia epidural para cesárea: estudio comparativo entre Bupivacaína Racémica (S50-R50 y Bupivacaína con exceso enantiomérico de 50% (S75-R25 a 0,5% asociadas al Sufentanil Epidural block for cesarean section: a comparative study between 0.5% racemic Bupivacaine (S50-R50 and 0.5% enantiomeric excess Bupivacaine (S75-R25 associated with Sufentanil

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Angélica de Fátima de Assunção Braga

2009-06-01

étrica.BACKGROUND AND OBJECTIVES: Epidural 0.5% racemic bupivacaine associated with opioids is a technique used in cesarean sections; however, its toxicity has been questioned. 50% Enantiomeric excess bupivacaine has lower cardio- and neurotoxicity. The efficacy of epidural 0.5% racemic bupivacaine and 0.5% enantiomeric excess bupivacaine associated with sufentanil in parturients undergoing cesarean sections was evaluated. METHODS: Fifty gravida at term, undergoing elective cesarean section under epidural block, were divided in two groups according to the local anesthetic used: Group I - 0.5% racemic bupivacaine with vasoconstrictor; and Group II - 0.5% enantiomeric excess bupivacaine (S75-R25 with vasoconstrictor. In both groups, the local anesthetic (100 mg was associated with sufentanil (20 µg, and a total of 24 mL of the solution was used. The following parameters were evaluated: latency of the sensitive blockade; maximal level of the sensitive blockade; degree for motor blockade; time of motor blockade regression; duration of analgesia; maternal side effects; and neonatal repercussions. RESULTS: Latency, maximal level of sensitive blockade, degree of motor blockade, and duration of analgesia were similar in both groups; the mean time for regression of the motor blockade was significantly smaller in Group II. The incidence of side effects was similar in both groups. Maternal cardiocirculatory changes and neonatal repercussions were not observed. CONCLUSIONS: Epidural racemic bupivacaine and 50% enantiomeric excess bupivacaine provided adequate anesthesia for cesarean sections. 50% Enantiomeric excess bupivacaine is a promising alternative for this procedure, since it has faster regression of the motor blockade, which is desirable in obstetric patients.

Identification and Evaluation of Cases for Excess Heat Utilisation Using GIS

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Fabian Bühler

2018-03-01

Full Text Available Excess heat is present in many sectors, and its utilization could reduce the primary energy use and emission of greenhouse gases. This work presents a geographical mapping of excess heat, in which excess heat from the industry and utility sector was distributed to specific geographical locations in Denmark. Based on this mapping, a systematic approach for identifying cases for the utilization of excess heat is proposed, considering the production of district heat and process heat, as well as power generation. The technical and economic feasibility of this approach was evaluated for six cases. Special focus was placed on the challenges for the connection of excess heat sources to heat users. To account for uncertainties in the model input, different methods were applied to determine the uncertainty of the results and the most important model parameters. The results show how the spatial mapping of excess heat sources can be used to identify their utilization potentials. The identified case studies show that it can be economically feasible to connect the heat sources to the public energy network or to use the heat to generate electricity. The uncertainty analysis suggests that the results are indicative and are particularly useful for a fast evaluation, comparison and prioritization of possible matches. The excess heat temperature and obtainable energy price were identified as the most important input parameters.

Enantiomeric separation of some demethylated analogues of clofibric acid by capillary zone electrophoresis and nano-liquid chromatography.

Science.gov (United States)

Fantacuzzi, Marialuigia; Bettoni, Giancarlo; D'Orazio, Giovanni; Fanali, Salvatore

2006-03-01

The enantiomeric separation of some demethylated analogues of clofibric acid, namely 2-(6-chloro-benzothiazol-2-ylsulfanyl)-, 2-(6-methoxy-benzothiazol-2-ylsulfanyl)-, 2-(quinolin-2-yloxy)-, 2-(6-chloro-quinolin-2-yloxy)-, 2-(7-chloro-quinolin-4-yloxy)-propionic acid (compounds A-E, respectively), has been studied by CZE and nano-LC using for the first technique two beta-CD derivatives and vancomycin added to the BGE and vancomycin-modified silica particles for the second one, with the aim to find the optimum experimental conditions for the baseline resolution. The type and the concentration of the chiral selector added to the BGE, the buffer pH, the type of organic modifier and its concentration, the capillary temperature and the applied voltage played a very important role in the enantioresolution of the analysed compounds. The use of 6-monodeoxy-6-monoamino-beta-CD allowed to achieve baseline resolution of four of five clofibric acid derivatives in less than 10 min while heptakis-(2,3,6-tri-O-methyl)-beta-CD partially resolved the same compounds in their enantiomers. Employing vancomycin as the chiral selector in CZE, the counter-current partial filling method was chosen achieving baseline resolution of four analytes. All the studied compounds were enantioresolved employing a capillary column packed with vancomycin stationary phase by nano-LC, and the resolution was strongly influenced by the concentration of the organic modifier and by the pH of the mobile phase. The best results were achieved at pH 4.5 in presence of 60% of methanol (MeOH). However, longer analysis times were observed in the experiments carried out by nano-LC.

Enantiomeric analogues of SCH 23390 as new probes for behavioral interactions between D-1 and D-2 dopaminergic function

International Nuclear Information System (INIS)

Waddington, J.L.; Mashurano, M.; Molloy, A.G.; O'Boyle, K.M.

1986-01-01

The purposes of this article are to describe the properties of some newer selective D 1 agents, and to characterize behavioral responses to a D 1 agonist in the intact adult rat. R- and S-SKandF 83566 and other new 1-phenyl-1H-3-benzazephines as selective D 1 agents are discussed. The displacement of 3 H-SCH 23390 from human brain D 1 receptors, in comparison with displacement of 3 H-piflutixol and 3 H-spiperone is shown. Enantiomeric induction of grooming and other behaviors by R- and S-SKandF 38393 is examined. Sections are also devoted to pharmacological characterization of behavioral responses to SKandF 38393 and to D 1 : D 2 receptor systems and the regulation of dopaminergic behaviors

Engineering an enantioselective amine oxidase for the synthesis of pharmaceutical building blocks and alkaloid natural products.

Science.gov (United States)

Ghislieri, Diego; Green, Anthony P; Pontini, Marta; Willies, Simon C; Rowles, Ian; Frank, Annika; Grogan, Gideon; Turner, Nicholas J

2013-07-24

The development of cost-effective and sustainable catalytic methods for the production of enantiomerically pure chiral amines is a key challenge facing the pharmaceutical and fine chemical industries. This challenge is highlighted by the estimate that 40-45% of drug candidates contain a chiral amine, fueling a demand for broadly applicable synthetic methods that deliver target structures in high yield and enantiomeric excess. Herein we describe the development and application of a "toolbox" of monoamine oxidase variants from Aspergillus niger (MAO-N) which display remarkable substrate scope and tolerance for sterically demanding motifs, including a new variant, which exhibits high activity and enantioselectivity toward substrates containing the aminodiphenylmethane (benzhydrylamine) template. By combining rational structure-guided engineering with high-throughput screening, it has been possible to expand the substrate scope of MAO-N to accommodate amine substrates containing bulky aryl substituents. These engineered MAO-N biocatalysts have been applied in deracemization reactions for the efficient asymmetric synthesis of the generic active pharmaceutical ingredients Solifenacin and Levocetirizine as well as the natural products (R)-coniine, (R)-eleagnine, and (R)-leptaflorine. We also report a novel MAO-N mediated asymmetric oxidative Pictet-Spengler approach to the synthesis of (R)-harmicine.

Steric parameters and excess properties of hydroxamic acids

International Nuclear Information System (INIS)

Patre, Sandhya; Thakur, Piyush; Pande, Rama

2012-01-01

Graphical abstract: Plot of excess molar volume, V E , vs X 2 of (A) PBHA in DMF, (B) PMNHA in DMF, and (C) PNHA in DMF, at (■), 298.15 K; (▪), 303.15 K; (▪), 308.15 K; and (▪), 313.15 K. Highlights: ► Apparent molar volume indicates greater solute–solvent interactions. ► Excess properties show higher dispersion force in solution than pure solvent. ► Excess parameters suggest strong solute–solvent and solute–solute interactions. ► Limiting apparent molar expansibilities instigate highly hydrophobic characters. ► Hepler’s constant suggest the structure promoter nature of hydroxamic acids. - Abstract: Steric parameters of N-phenylbenzo-, N-phenyl-4-methyl-3-nitrobenzo-, and N-phenyl-4-nitrobenzo-, hydroxamic acids were measured in N,N-dimethylformamide (DMF) as a function of their concentrations at T = (298.15, 303.15, 308.15, and 313.15) K. The apparent molar volume (V φ ), limiting apparent molar volume (V φ 0 ) at infinite dilution and the slope (S V ∗ ) are calculated from the experimental values of density (ρ) by applying the Masson’s equation. The apparent molar expansibility at infinite dilution (φ E 0 ), molar volume (V) and the excess molar volume (V E ) are also computed. The refractive indices (n) have been used to calculate the steric parameters, viz. molar refraction (R M ), polarizability (α) and excess molar refraction (R) of these molecules. The results show the strong solute–solvent interactions present in the system and thus, help to explore the molecular structure.

Biological sludge solubilisation for reduction of excess sludge production in wastewater treatment process.

Science.gov (United States)

Yamaguchi, T; Yao, Y; Kihara, Y

2006-01-01

A novel sludge disintegration system (JFE-SD system) was developed for the reduction of excess sludge production in wastewater treatment plants. Chemical and biological treatments were applied to disintegrate excess sludge. At the first step, to enhance biological disintegration, the sludge was pretreated with alkali. At the second step, the sludge was disintegrated by biological treatment. Many kinds of sludge degrading microorganisms integrated the sludge. The efficiency of the new sludge disintegration system was confirmed in a full-scale experiment. The JFE-SD system reduced excess sludge production by approximately 50% during the experimental period. The quality of effluent was kept at quite a good level. Economic analysis revealed that this system could significantly decrease the excess sludge treatment cost.

Asymmetric Diels-Alder reactions with 5-menthyloxy-2(5H)-furanones

NARCIS (Netherlands)

Jong, Johannes Cornelis de

2006-01-01

At the beginning of the reseach described in this thesis the catalytic asymmetric Diels-Alder reaction had scarcely been investigated. No good catalytic processes with high enantiomeric excess were known at that time. At the same time the Diels-Alder reactions with chiral dienophiles needed further

Candida antartica lipase-catalyzed hydrolysis of 4-substituted bis(ethoxycarbonylmethyl) 1,4-dihydropyridine-3,5-dicarboxylates as the key step in the synthesis of optically active dihydropyridines

NARCIS (Netherlands)

Sobolev, A.; Franssen, M.C.R.; Makarova, N.; Duburs, G.; Groot, de Æ.

2001-01-01

Prochiral bis(ethoxycarbonylmethyl) substituted 4-aryl-1,4-dihydropyridine-3,5-dicarboxylates were hydrolyzed enantioselectively by Candida antarctica lipase B (Novozym 435). The enantiomeric excesses varied from 68 to 93°depending on the substituent at position 4. In some cases, the e.e. could be

Kinetic Resolution and Stereoselective Synthesis of 3-Substituted Aspartic Acids by Using Engineered Methylaspartate Ammonia Lyases

NARCIS (Netherlands)

Raj, Hans; Szymanski, Wiktor; Villiers, Jandré de; Puthan Veetil, Vinod; Quax, Wim J.; Shimamoto, Keiko; Janssen, Dick B.; Feringa, Ben L.; Poelarends, Gerrit J.

2013-01-01

Kinetic resolution and asymmetric synthesis of various valuable 3-substituted aspartic acids, which were obtained in fair to good yields with diastereomeric ratio values of up to >98:2 and enantiomeric excess values of up to >99 %, by using engineered methylaspartate ammonia lyases are described.

Predictors of excessive use of social media and excessive online gaming in Czech teenagers.

Science.gov (United States)

Spilková, Jana; Chomynová, Pavla; Csémy, Ladislav

2017-12-01

Background and aims Young people's involvement in online gaming and the use of social media are increasing rapidly, resulting in a high number of excessive Internet users in recent years. The objective of this paper is to analyze the situation of excessive Internet use among adolescents in the Czech Republic and to reveal determinants of excessive use of social media and excessive online gaming. Methods Data from secondary school students (N = 4,887) were collected within the 2015 European School Survey Project on Alcohol and Other Drugs. Logistic regression models were constructed to describe the individual and familial discriminative factors and the impact of the health risk behavior of (a) excessive users of social media and (b) excessive players of online games. Results The models confirmed important gender-specific distinctions - while girls are more prone to online communication and social media use, online gaming is far more prevalent among boys. The analysis did not indicate an influence of family composition on both the excessive use of social media and on excessive online gaming, and only marginal effects for the type of school attended. We found a connection between the excessive use of social media and binge drinking and an inverse relation between excessive online gaming and daily smoking. Discussion and conclusion The non-existence of significant associations between family environment and excessive Internet use confirmed the general, widespread of this phenomenon across the social and economic strata of the teenage population, indicating a need for further studies on the topic.

Missing Linker Defects in a Homochiral Metal-Organic Framework: Tuning the Chiral Separation Capacity.

Science.gov (United States)

Slater, Benjamin; Wang, Zeru; Jiang, Shanxue; Hill, Matthew R; Ladewig, Bradley P

2017-12-20

Efficient chiral separation remains a very challenging task due to the identical physical and chemical properties of the enantiomers of a molecule. Enantiomers only behave differently from each other in the presence of other chiral species. Homochiral metal-organic frameworks (MOFs) have received much attention for their promising enantioseparation properties. However, there are still challenges to overcome in this field such as high enantiomeric separation. Structural defects play an important role in the properties of MOFs and can significantly change the pore architecture. In this work, we introduced missing linker defects into a homochiral metal-organic framework [Zn 2 (bdc)(l-lac)(dmf)] (ZnBLD; bdc = 1,4-benzenedicarboxylic acid, l-lac = l-lactic acid, dmf = N,N'-dimethylformamide) and observed an increase in enantiomeric excess for 1-phenylethanol of 35% with the defective frameworks. We adjusted the concentration of monocarboxylic acid ligand l-lactic acid by varying the ratio of Zn 2+ to ligand from 0.5 to 0.85 mmol. Additionally, a defective framework was synthesized with propanoic acid as modulator. In order to elucidate the correlation between defects and enantiomeric excess, five characterization techniques (FTIR, TGA, 1 H NMR, ICP, and PXRD) were employed. Full width at half-maximum analysis (fwhm) was performed on the powder X-ray diffraction traces and showed that the higher concentration of monocarboxylic acid MOFs were isostructural but suffered from increased fwhm values.

Synthesis of Tertiary and Quaternary Amine Derivatives from Wood Resin as Chiral NMR Solvating Agents

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Tiina Laaksonen

2015-11-01

Full Text Available Chiral tertiary and quaternary amine solvating agents for NMR spectroscopy were synthesized from the wood resin derivative (+-dehydroabietylamine (2. The resolution of enantiomers of model compounds [Mosher’s acid (3 and its n-Bu4N salt (4] (guests by (+-dehydroabietyl-N,N-dimethylmethanamine (5 and its ten different ammonium salts (hosts was studied. The best results with 3 were obtained using 5 while with 4 the best enantiomeric resolution was obtained using (+-dehydroabietyl-N,N-dimethylmethanaminium bis(trifluoromethane-sulfonimide (6. The compounds 5 and 6 showed a 1:1 complexation behaviour between the host and guest. The capability of 5 and 6 to recognize the enantiomers of various α-substituted carboxylic acids and their n-Bu4N salts in enantiomeric excess (ee determinations was demonstrated. A modification of the RES-TOCSY NMR pulse sequence is described, allowing the enhancement of enantiomeric discrimination when the resolution of multiplets is insufficient.

Disappearing Enantiomorphs: Single Handedness in Racemate Crystals.

Science.gov (United States)

Parschau, Manfred; Ernst, Karl-Heinz

2015-11-23

Although crystallization is the most important method for the separation of enantiomers of chiral molecules in the chemical industry, the chiral recognition involved in this process is poorly understood at the molecular level. We report on the initial steps in the formation of layered racemate crystals from a racemic mixture, as observed by STM at submolecular resolution. Grown on a copper single-crystal surface, the chiral hydrocarbon heptahelicene formed chiral racemic lattice structures within the first layer. In the second layer, enantiomerically pure domains were observed, underneath which the first layer contained exclusively the other enantiomer. Hence, the system changed from a 2D racemate into a 3D racemate with enantiomerically pure layers after exceeding monolayer-saturation coverage. A chiral bias in form of a small enantiomeric excess suppressed the crystallization of one double-layer enantiomorph so that the pure minor enantiomer crystallized only in the second layer. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

2-Methylbutyl acetate in wines: Enantiomeric distribution and sensory impact on red wine fruity aroma.

Science.gov (United States)

Cameleyre, Margaux; Lytra, Georgia; Tempere, Sophie; Barbe, Jean-Christophe

2017-12-15

Enantiomers of 2-methylbutyl acetate were assayed in red and white commercial wines from various vintages and origins, using chiral gas chromatography (γ-cyclodextrin), revealing the exclusive presence of the S-enantiomeric form. Results also confirmed that (S)-2-methylbutyl acetate levels were generally higher in red than white wines of the same age, and that acetate levels increased gradually during ageing. Olfactory threshold of (S)-2-methylbutyl acetate was evaluated at 313µg/L in dilute alcohol solution (12% v/v) and 1083µg/L in a fruity aromatic reconstitution, reflecting its presence in wines at subthreshold concentrations. At concentrations considerably lower than its olfactory threshold, 2-methylbutyl acetate was associated with blackberry-fruit and banana notes. It was also revealed that, even at subthreshold concentrations, this compound had a modification on the perception of fruity aromas in the matrices studied. Sensory profiles highlighted, for the first time, its specific contribution to black-, fresh-, and jammy-fruit notes, despite its subthreshold concentrations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Enantioselective copper-catalysed propargylic substitution: synthetic scope study and application in formal total syntheses of (+)-anisomycin and (-)-cytoxazone

NARCIS (Netherlands)

Detz, R.J.; Abiri, Z.; le Griel, R.; Hiemstra, H.; van Maarseveen, J.H.

2011-01-01

A copper catalyst with a chiral pyridine-2,6-bisoxazoline (pybox) ligand was used to convert a variety of propargylic esters with different side chains (R=Ar, Bn, alkyl) into their amine counterparts in very high yields and with good enantioselectivities (up to 90 % enantiomeric excess (ee)).

The asymmetric synthesis of (+-sitophilure, the natural form of the aggregation pheromone of Sitophilus oryzae L. and Sitophilus zeamais M.

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Pilli Ronaldo A.

1999-01-01

Full Text Available The asymmetric synthesis of (+-sitophilure, the aggregation pheromone of Sitophilus oryzae L. and Sitophilus zeamais M., was carried out in 12 steps, 18% overall yield and 82% enantiomeric excess from the enzymatic reduction of methyl 3-oxopentanoate with S. cerevisiae in the presence of ethyl chloroacetate.

Formation of diphosphates. A NMR study on the mechanism and stereochemistry of diphosphate formation from chiral dioxaphosphorinanes

NARCIS (Netherlands)

Hulst, R; Visser, J.M.; De Vries, N.K.; Zijlstra, R.W J; Kooijman, H.; Smeets, W.J.J.; Spek, A.L.; Feringa, B.L.

2000-01-01

During the use of chiral 2-oxo-1,3,2-dioxaphosphorinanes as derivatizing reagents in the enantiomeric excess determination of amines, alcohols, and unprotected amino acids, minor traces of side reaction products were observed by 1H and 31P NMR spectroscopy. Analysis of the reaction mixture showed

Solvation of excess electrons trapped in charge pockets on molecular surfaces

Science.gov (United States)

Jalbout, Abraham F.

This work considers the ability of hydrogen fluoride (HF) to solvate excess electrons located on cyclic hydrocarbon surfaces. The principle applied involves the formation of systems in which excess electrons can be stabilized not only on concentrated molecular surface charge pockets but also by HF. Recent studies have shown that OH groups can form stable hydrogen-bonded networks on one side of a hydrocarbon surface (i.e. cyclohexane sheets), at the same time, the hydrogen atoms on the opposite side of this surface form a pocket of positive charge can attract the excess electron. This density can be further stabilized by the addition of an HF molecule that can form an 'anion with an internally solvated electron' (AISE) state. These systems are shown to be stable with respect to vertical electron detachment (VDE).

Constrained convex minimization via model-based excessive gap

OpenAIRE

Tran Dinh, Quoc; Cevher, Volkan

2014-01-01

We introduce a model-based excessive gap technique to analyze first-order primal- dual methods for constrained convex minimization. As a result, we construct new primal-dual methods with optimal convergence rates on the objective residual and the primal feasibility gap of their iterates separately. Through a dual smoothing and prox-function selection strategy, our framework subsumes the augmented Lagrangian, and alternating methods as special cases, where our rates apply.

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Efficient use of the readily accessible chiral 2-symmetric acyclic diamines (1-2) as well as macrocyclic amines (3-5) containing trans-1,2-diaminocyclohexyl moiety as chiral solvating agents (CSA) for the determination of enantiomeric excess of representative carboxylic acids (6-7) and an amino acid derivative (8) is ...

Excess Entropy and Diffusivity

Indian Academy of Sciences (India)

First page Back Continue Last page Graphics. Excess Entropy and Diffusivity. Excess entropy scaling of diffusivity (Rosenfeld,1977). Analogous relationships also exist for viscosity and thermal conductivity.

24 CFR 236.60 - Excess Income.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Excess Income. 236.60 Section 236... § 236.60 Excess Income. (a) Definition. Excess Income consists of cash collected as rent from the... Rent. The unit-by-unit requirement necessitates that, if a unit has Excess Income, the Excess Income...

Absolute configuration and enantiomeric composition of partially resolved mandelic, atrolactic and lactic acids by {sup 1}H NMR of their (S)-2-methylbutyl esters

Energy Technology Data Exchange (ETDEWEB)

Andrade, Francisco A. da C.; Mendes, Maricleide P. de L.; Fonseca, Neuracy C. da, E-mail: fandrade@ufba.br [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Instituto de Quimica. Departamento de Quimica Organica

2013-06-15

The mandelic, atrolactic and lactic acid esters of the (S)-2-methyl-1-butanol were examined as diastereomeric derivatives for the stereochemical analysis of the mentioned acids by {sup 1}H nuclear magnetic resonance (NMR) at 300 MHz. The diastereomeric esters showed distinctive signals in the methylenic absorption range (O-CH{sub 2}-CH) of the alcoholic moieties. By spectral analysis at this region, absolute configurations were attributed, chemical shifts of the correspondent pro-(R) and pro-(S) hydrogens from the methylene group of the alcohol moiety were assigned and enantiomeric compositions were determined for the original partially resolved acids. (author)

Access to Optically Pure β-Hydroxy Esters via Non-Enzymatic Kinetic Resolution by a Planar-Chiral DMAP Catalyst

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Alba E. Díazlvarez

2014-09-01

Full Text Available The development of new approaches to obtain optically pure β-hydroxy esters is an important area in synthetic organic chemistry since they are precursors of other high value compounds. Herein, the kinetic resolution of racemic β-hydroxy esters using a planar-chiral DMAP derivative catalyst is presented. Following this procedure, a range of aromatic β-hydroxy esters was obtained in excellent selectivities (up to s = 107 and high enantiomeric excess (up to 99% ee. Furthermore, the utility of the present method was demonstrated in the synthesis of (S-3-hydroxy-N-methyl-3-phenylpropanamide, a key intermediate for bioactive molecules such as fluoxetine, tomoxetine or nisoxetine, in its enantiomerically pure form.

Mirror image hydrocarbons from Tropical and Boreal forests

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J. Williams

2007-01-01

Full Text Available Monoterpenes, emitted in large quantities by trees to attract pollinators and repel herbivores, can exist in mirror image forms called enantiomers. In this study such enantiomeric pairs have been measured in ambient air over extensive forest ecosystems in South America and northern Europe. For the dominant monoterpene, α-pinene, the (−-form was measured in large excess over the (+-form over the Tropical rainforest, whereas the reverse was observed over the Boreal forest. Interestingly, over the Tropical forest (−-α-pinene did not correlate with its own enantiomer, but correlated well with isoprene. The results indicate a remarkable ecosystem scale enantiomeric fingerprint and a nexus between the biosphere and atmosphere.

Do dividend shocks affect excess returns? An experimental study

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Draganac Dragana

2017-01-01

Full Text Available The dividend announcement of a company is an informational event that can cause underreaction, momentum, overreaction, post-dividend announcement drift, and mean reversion. It is the uncertainty surrounding dividend announcements that leads to such behavioural phenomena. Most authors consider that underreaction occurs after dividend shocks because new information about the dividend is being slowly and gradually built into the stock price. The effect of dividend shocks is often reflected in excess returns, which can last up to one year after the shock. The experiment described in this paper tests whether statistically significant excess returns are realized after a shock dividend announcement. Participants trade with the stocks of two companies, which only differ by dividend-generating stochastic process. The dividend process of Company 2 is a Merton-style jump-diffusion process (consisting of two parts: Brownian motion and Poisson jump, while the dividend process of Company 1 contains only the Brownian motion component. Statistically significant excess returns are expected when trading with Company 2 stocks. An autoregressive model is applied in order to test this hypothesis. The conclusion is that a dividend shock is followed by statistically significant excess returns in 20 of the 22 experiments, which implies that markets are inefficient after sudden and large changes in dividends. Underreaction and discount rate effects are identified.

Separation and enrichment of enantiopure from racemic compounds using magnetic levitation.

Science.gov (United States)

Yang, Xiaochuan; Wong, Shin Yee; Bwambok, David K; Atkinson, Manza B J; Zhang, Xi; Whitesides, George M; Myerson, Allan S

2014-07-18

Crystallization of a solution with high enantiomeric excess can generate a mixture of crystals of the desired enantiomer and the racemic compound. Using a mixture of S-/RS-ibuprofen crystals as a model, we demonstrated that magnetic levitation (MagLev) is a useful technique for analysis, separation and enantioenrichment of chiral/racemic products.

Conventional physics can explain cold fusion excess heat

Science.gov (United States)

Chubb, S. R.

In 1989, when Fleischmann, Pons and Hawkins (FP), claimed they had created room temperature, nuclear fusion in a solid, a firestorm of controversy erupted. Beginning in 1991, the Office of Naval Research began a decade-long study of the FP excess heat effect. This effort documented the fact that the excess heat that FP observed is the result of a form of nuclear fusion that can occur in solids at reduced temperature, dynamically, through a deuteron (d)+d□4He reaction, without high-energy particles or □ rays. A key reason this fact has not been accepted is the lack of a cogent argument, based on fundamental physical ideas, justifying it. In the paper, this question is re-examined, based on a generalization of conventional energy band theory that applies to finite, periodic solids, in which d's are allowed to occupy wave-like, ion band states, similar to the kinds of states that electrons occupy in ordinary metals. Prior to being experimentally observed, the Ion Band State Theory (IBST) of cold fusion predicted a potential d+d□4He reaction, without high energy particles, would explain the excess heat, the 4He would be found in an unexpected place (outside heat-producing electrodes), and high-loading, x□1, in PdDx, would be required.

Experimental excess molar properties of binary mixtures of (3-amino-1-propanol + isobutanol, 2-propanol) at T = (293.15 to 333.15) K and modelling the excess molar volume by Prigogine–Flory–Patterson theory

International Nuclear Information System (INIS)

Kermanpour, F.; Niakan, H.Z.

2012-01-01

Highlights: ► Density and viscosity of binary mixtures of propanol derivatives were measured at T = (293.15 to 333.15) K. ► The excess molar properties were calculated from these experimental data and correlated by Redlich–Kister equation. ► The PFP model was applied for correlating the excess molar volumes. - Abstract: Density and viscosity of binary mixtures of (x 1 3-amino-1-propanol + x 2 isobutanol) and (x 1 3-amino-1-propanol + x 2 2-propanol) were measured over the entire composition range and from temperatures (293.15 to 333.15) K at ambient pressure. The excess molar volumes and viscosity deviations were calculated and correlated by the Redlich–Kister (RK) equation. The thermal expansion coefficient and its excess value, isothermal coefficient of excess molar enthalpy, and excess partial molar volumes were determined by using the experimental values of density and are described as a function of composition and temperature. The excess molar volumes are negative over the entire mole fraction range for both mixtures and increase with increasing temperature. The excess molar volumes obtained were correlated by the Prigogine–Flory–Patterson (PFP) model. The viscosity deviations of the binary mixtures are negative over the entire composition range and decrease with increasing temperature.

Enantioselective Synthesis of Various Cyanohydrins Using Covalently Immobilized Preparations of Hydroxynitrile Lyase from Prunus dulcis.

Science.gov (United States)

Alagöz, Dilek; Tükel, S Seyhan; Yildirim, Deniz

2015-11-01

The carrier-based and carrier-free (cross-linked enzyme aggregate) covalent immobilizations of Prunus dulcis hydroxynitrile lyase were investigated. The immobilized preparations were tested for enantioselective carbon-carbon bond formation activity in the biphasic medium. Of the tested preparations, only cross-linked enzyme aggregate of P. dulcis hydroxynitrile lyase (PdHNL-CLEA) achieved the synthesis of (R)-mandelonitrile with 93% yield and 99% enantiopurity. PdHNL-CLEA was also used in the synthesis of various (R)-cyanohydrins from corresponding aldehydes/ketones and hydrocyanic acid. When 4-methoxybenzaldehyde, 4-methyl benzaldehyde, and 4-hydroxybenzaldehyde were used as substrates, the yield-enantiomeric excess of corresponding (R)-cyanohydrins were obtained as 95-95, 85-79, and 2-25%, respectively, after 96 h at pH 4.0 and 5 °C. For acetophenone, 4-fluoroacetophenone, 4-chloroacetophenone, 4-bromoacetophenone, and 4-iodoacetophenone, the yield-enantiomeric excess of corresponding (R)-cyanohydrins were 1-99, 20-84, 11-95, 5-99, and 3-24%, respectively at the same conditions. The results demonstrate PdHNL-CLEA can be effectively used in the synthesis of (R)-mandelonitrile.

Molecular Asymmetry in Prebiotic Chemistry: An Account from Meteorites

Directory of Open Access Journals (Sweden)

Sandra Pizzarello

2016-04-01

Full Text Available Carbonaceous Chondrite (CC meteorites are fragments of asteroids, solar planetesimals that never became large enough to separate matter by their density, like terrestrial planets. CC contains various amounts of organic carbon and carry a record of chemical evolution as it came to be in the Solar System, at the time the Earth was formed and before the origins of life. We review this record as it pertains to the chiral asymmetry determined for several organic compounds in CC, which reaches a broad molecular distribution and enantiomeric excesses of up to 50%–60%. Because homochirality is an indispensable attribute of extant polymers and these meteoritic enantiomeric excesses are still, to date, the only case of chiral asymmetry in organic molecules measured outside the biosphere, the possibility of an exogenous delivery of primed prebiotic compounds to early Earth from meteorites is often proposed. Whether this exogenous delivery held a chiral advantage in molecular evolution remains an open question, as many others regarding the origins of life are.

34 CFR 300.16 - Excess costs.

Science.gov (United States)

2010-07-01

... 34 Education 2 2010-07-01 2010-07-01 false Excess costs. 300.16 Section 300.16 Education... DISABILITIES General Definitions Used in This Part § 300.16 Excess costs. Excess costs means those costs that... for an example of how excess costs must be calculated.) (Authority: 20 U.S.C. 1401(8)) ...

Rotational spectroscopy and three-wave mixing of 4-carvomenthenol: A technical guide to measuring chirality in the microwave regime

International Nuclear Information System (INIS)

Shubert, V. Alvin; Schmitz, David; Medcraft, Chris; Krin, Anna; Patterson, David; Doyle, John M.; Schnell, Melanie

2015-01-01

We apply chirality sensitive microwave three-wave mixing to 4-carvomenthenol, a molecule previously uncharacterized with rotational spectroscopy. We measure its rotational spectrum in the 2-8.5 GHz range and observe three molecular conformers. We describe our method in detail, from the initial step of spectral acquisition and assignment to the final step of determining absolute configuration and enantiomeric excess. Combining fitted rotational constants with dipole moment components derived from quantum chemical calculations, we identify candidate three-wave mixing cycles which were further tested using a double resonance method. Initial optimization of the three-wave mixing signal is done by varying the duration of the second excitation pulse. With known transition dipole matrix elements, absolute configuration can be directly determined from a single measurement

Composition and Enantiomeric Analysis of the Essential Oil of the Fruits and the Leaves of Pistacia vera from Greece

Directory of Open Access Journals (Sweden)

Anastasia Tsokou

2007-06-01

Full Text Available The essential oils of the fruits and the leaves of pistachio (Pistacia vera L. were analyzed by GC and GC/MS. Fresh unripe pistachio fruits were richer in essential oil (0.5 %, w/w than the leaves (0.1 %, w/w. Twenty one compounds were identified in the essential oil of the fruits and the major components were (+-α-pinene (54.6 % and terpinolene (31.2 %. The enantiomeric ratio of the major constituents of the essential oil of the fruits was determined using chiral GC/MS and it was found that the (+/(--α-pinene ratio was 99.5:0.5, (+/(--limonene 80:20, (+/(--β-pinene 96:4, and (+/(--α-terpineol 0:100. Thirty three compounds were identified in the essential oil of the leaves and the major components were found to be α-pinene (30.0 %, terpinolene (17.6 % and bornyl acetate (11.3 %.

Enantioselective conjugate radical addition to alpha'-hydroxy enones.

Science.gov (United States)

Lee, Sunggi; Lim, Chae Jo; Kim, Sunggak; Subramaniam, Rajesh; Zimmerman, Jake; Sibi, Mukund P

2006-09-14

Enantioselective conjugate radical addition to alpha'-hydroxy alpha,beta-unsaturated ketones, compounds containing bidentate donors, has been investigated. It has been found that radical additions to alpha'-hydroxy alpha,beta-unsaturated ketones in the presence of Mg(NTf2)2 and bisoxazoline ligand 5a proceeded cleanly, yielding the addition products in high chemical yields and good enantiomeric excesses.

Chemoenzymatic synthesis of a series of 4-substituted glutamate analogues and pharmacological characterization at human glutamate transporters subtypes 1-3

DEFF Research Database (Denmark)

Alaux, Sebastien; Kusk, Mie; Sagot, Emanuelle

2005-01-01

A series of nine L-2,4-syn-4-alkylglutamic acid analogues (1a-i) were synthesized in high yield and high enantiomeric excess (>99% ee) from their corresponding 4-substituted ketoglutaric acids (2a-i), using the enzyme aspartate aminotransferase (AAT) from pig heart or E. coli. The synthesized com...... subtypes EAAT1-3 while maintaining inhibitory activity....

Membrane-bound alcohol dehydrogenase is essential for glyceric acid production in Acetobacter tropicalis.

Science.gov (United States)

Habe, Hiroshi; Sato, Shun; Fukuoka, Tokuma; Kitamoto, Dai; Yakushi, Toshiharu; Matsushita, Kazunobu; Sakaki, Keiji

2011-01-01

Acetobacter tropicalis NBRC16470 can produce highly enantiomerically pure D-glyceric acid (D-GA; >99 % enantiomeric excess) from glycerol. To investigate whether membrane-bound alcohol dehydrogenase (mADH) is involved in GA production in A. tropicalis, we amplified part of the gene encoding mADH subunit I (adhA) using polymerase chain reaction and constructed an adhA-disrupted mutant of A. tropicalis (ΔadhA). Because ΔadhA did not produce GA, we confirmed that mADH is essential for the conversion of glycerol to GA. We also cloned and sequenced the entire region corresponding to adhA and adhB, which encodes mADH subunit II. The sequences showed high identities (84-86 %) with the equivalent mADH subunits from other Acetobacter spp.

Excessive or unwanted hair in women

Science.gov (United States)

Hypertrichosis; Hirsutism; Hair - excessive (women); Excessive hair in women; Hair - women - excessive or unwanted ... Women normally produce low levels of male hormones (androgens). If your body makes too much of this ...

Excess in Self-Defense and its Consequences to the Assesment of the Victim's Legal Crime Precipitation

Directory of Open Access Journals (Sweden)

Diego José Dias Mendes

2016-10-01

Full Text Available This article explores the ongoing debate concerning excessive self-defense and its possible consequences to the assessment of victim legal precipitation of crimes. While part one introduces excess in its most accepted structure, part two describes theories that pursue the best reasons why the excess may, in certain cases, not be punished, focusing the ones who claim that those reasons relate to agressor’s self-responsibility, then applying their arguments to the evaluation of legal crime precipitation. It concludes that these theories can only hold by discriminating moral value of guilty and innocent victims, which is unacceptable.

Thermodynamic excess quantities of ternary Au-Co-Pd melts by computer-aided Knudsen cell mass spectrometry

International Nuclear Information System (INIS)

Tomiska, Josef

2009-01-01

Computer-aided Knudsen cell mass spectrometry is used for the thermodynamic investigations on ternary Au-Co-Pd melts over the entire range of composition. The 'digital intensity-ratio' (DIR)-method has been applied for the determination of the thermodynamic excess quantities, and the ternary thermodynamically adapted power (TAP) series concept is used for algebraic representation of the thermodynamic mixing behavior. The corresponding TAP parameters as well as the values of the molar excess Gibbs energies G E , of the molar heats of mixing H E , of the molar excess entropies S E , and of the thermodynamic activities at 1800 K are presented.

Excessive growth.

Science.gov (United States)

Narayanaswamy, Vasudha; Rettig, Kenneth R; Bhowmick, Samar K

2008-09-01

Tall stature and excessive growth syndrome are a relatively rare concern in pediatric practice. Nevertheless, it is important to identify abnormal accelerated growth patterns in children, which may be the clue in the diagnosis of an underlying disorder. We present a case of pituitary gigantism in a 2 1/2-year-old child and discuss the signs, symptoms, laboratory findings, and the treatment. Brief discussions on the differential diagnosis of excessive growth/tall stature have been outlined. Pituitary gigantism is very rare in the pediatrics age group; however, it is extremely rare in a child that is less than 3 years of age. The nature of pituitary adenoma and treatment options in children with this condition have also been discussed.

Reversed-Phase UHPLC Enantiomeric Separation of Rasagiline Salts Using a Chiralpak® AGP Column

Directory of Open Access Journals (Sweden)

Nagarajan Balaji

2017-07-01

Full Text Available We report the first rapid ultra-high performance liquid chromatographic (UHPLC enantiomeric reversed-phase separation of rasagiline mesylate and its tartrate salts using a Chiralpak® AGP column (50 mm × 2.1 mm, 5 μm as a stationary phase. This method was developed as an alternative to the usage of previously reported normal-phase chiral LC columns for isomer separation. Our method is based on an isocratic approach using a mixture of ammonium acetate and isopropyl alcohol (90:10, v/v as the mobile phase (0.6 mL/min flow rate. The detection limit (at a detection wavelength of 210 nm and quantification limit for the rasagiline enantiomers were 0.06 and 0.2 μg/mL, respectively. This method is compatible with the UHPLC-MS technique. The successful separation of rasagiline and its enantiomer was confirmed by determining the corresponding specific optical rotation values. Our method will be applicable for detecting rasagiline enantiomers during the control of manufacturing processes, and for use in rapid analysis for quality control in pharmaceutical industry to obtain optically pure pharmaceutical substances. This method was validated in terms of its precision, limit of detection, limit of quantification, linearity, accuracy, robustness, ruggedness, specificity, forced degradation, and solution stability, according to International Council on Harmonization Validation Guidelines Q2 (R1.

Thermodynamic properties of binary mixtures of tetrahydropyran with pyridine and isomeric picolines: Excess molar volumes, excess molar enthalpies and excess isentropic compressibilities

International Nuclear Information System (INIS)

Saini, Neeti; Jangra, Sunil K.; Yadav, J.S.; Sharma, Dimple; Sharma, V.K.

2011-01-01

Research highlights: → Densities, ρ and speeds of sound, u of tetrahydropyran (i) + pyridine or α-, β- or γ-picoline (j) binary mixtures at 298.15, 303.15 and 308.15 K and excess molar enthalpies, H E of the same set of mixtures at 308.15 K have been measured as a function of composition. → The observed densities and speeds of sound values have been employed to determine excess molar volumes, V E and excess isentropic compressibilities, κ S E . → Topology of the constituents of mixtures has been utilized (Graph theory) successfully to predict V E , H E and κ S E data of the investigated mixtures. → Thermodynamic data of the various mixtures have also been analyzed in terms of Prigogine-Flory-Patterson (PFP) theory. - Abstract: Densities, ρ and speeds of sound, u of tetrahydropyran (i) + pyridine or α-, β- or γ- picoline (j) binary mixtures at 298.15, 303.15 and 308.15 K and excess molar enthalpies, H E of the same set of mixtures at 308.15 K have been measured as a function of composition using an anton Parr vibrating-tube digital density and sound analyzer (model DSA 5000) and 2-drop micro-calorimeter, respectively. The resulting density and speed of sound data of the investigated mixtures have been utilized to predict excess molar volumes, V E and excess isentropic compressibilities, κ S E . The observed data have been analyzed in terms of (i) Graph theory; (ii) Prigogine-Flory-Patterson theory. It has been observed that V E , H E and κ S E data predicted by Graph theory compare well with their experimental values.

Excess wind power

DEFF Research Database (Denmark)

Østergaard, Poul Alberg

2005-01-01

Expansion of wind power is an important element in Danish climate change abatement policy. Starting from a high penetration of approx 20% however, momentary excess production will become an important issue in the future. Through energy systems analyses using the EnergyPLAN model and economic...... analyses it is analysed how excess productions are better utilised; through conversion into hydrogen of through expansion of export connections thereby enabling sales. The results demonstrate that particularly hydrogen production is unviable under current costs but transmission expansion could...

A novel concept of QUADRISO particles. Part II: Utilization for excess reactivity control

Energy Technology Data Exchange (ETDEWEB)

Talamo, Alberto, E-mail: alby@anl.go [Nuclear Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

2010-07-15

In high temperature reactors, burnable absorbers are utilized to manage the excess reactivity at the early stage of the fuel cycle. In this paper QUADRISO particles are proposed to manage the initial excess reactivity of high temperature reactors. The QUADRISO concept synergistically couples the decrease of the burnable poison with the decrease of the fissile materials at the fuel particle level. This mechanism is set up by introducing a burnable poison layer around the fuel kernel in ordinary TRISO particles or by mixing the burnable poison with any of the TRISO coated layers. At the beginning of life, the initial excess reactivity is small because some neutrons are absorbed in the burnable poison and they are prevented from entering the fuel kernel. At the end of life, when the absorber is almost depleted, more neutrons stream into the fuel kernel of QUADRISO particles causing fission reactions. The mechanism has been applied to a prismatic high temperature reactor with europium or erbium burnable absorbers, showing a significant reduction in the initial excess reactivity of the core.

A novel concept of QUADRISO particles. Part II: Utilization for excess reactivity control

International Nuclear Information System (INIS)

Talamo, Alberto

2010-01-01

In high temperature reactors, burnable absorbers are utilized to manage the excess reactivity at the early stage of the fuel cycle. In this paper QUADRISO particles are proposed to manage the initial excess reactivity of high temperature reactors. The QUADRISO concept synergistically couples the decrease of the burnable poison with the decrease of the fissile materials at the fuel particle level. This mechanism is set up by introducing a burnable poison layer around the fuel kernel in ordinary TRISO particles or by mixing the burnable poison with any of the TRISO coated layers. At the beginning of life, the initial excess reactivity is small because some neutrons are absorbed in the burnable poison and they are prevented from entering the fuel kernel. At the end of life, when the absorber is almost depleted, more neutrons stream into the fuel kernel of QUADRISO particles causing fission reactions. The mechanism has been applied to a prismatic high temperature reactor with europium or erbium burnable absorbers, showing a significant reduction in the initial excess reactivity of the core.

75 FR 27572 - Monthly Report of Excess Income and Annual Report of Uses of Excess Income

Science.gov (United States)

2010-05-17

... Income and Annual Report of Uses of Excess Income AGENCY: Office of the Chief Information Officer, HUD... permitted to retain Excess Income for projects under terms and conditions established by HUD. Owners must request to retain some or all of their Excess Income. The request must be submitted through http://www.pay...

Superconductors with excess quasiparticles

International Nuclear Information System (INIS)

Elesin, V.F.; Kopaev, Y.V.

1981-01-01

This review presents a systematic kinetic theory of nonequilibrium phenomena in superconductors with excess quasiparticles created by electromagnetic or tunnel injection. The energy distributions of excess quasiparticles and of nonequilibrium phonons, dependence of the order parameter on the power and frequency (or intensity) of the electromagnetic field, magnetic properties of nonequilibrium superconductors, I-V curves of superconductor-insulator-superconductor junctions, and other properties are described in detail. The stability of superconducting states far from thermodynamic equilibrium is investigated and it is shown that characteristic instabilities leading to the formation of nonuniform states of a new type or phase transitions of the first kind are inherent to superconductors with excess quasiparticles. The results are compared with experimental data

Synthesis of enantiomerically enriched drug precursors and an insect pheromone via reduction of ketones using commercially available carbonyl reductase screening kit "Chiralscreen® OH".

Science.gov (United States)

Nagai, Toshiya; Sakurai, Saki; Natori, Naoki; Hataoka, Manaka; Kinoshita, Takako; Inoue, Hiroyoshi; Hanaya, Kengo; Shoji, Mitsuru; Sugai, Takeshi

2018-04-01

Commercially available "Chiralscreen® OH" starter kit containing five types of carbonyl reductases (E001, E007, E031, E039, and E078) was used for the reduction of several aromatic and aliphatic ketones to obtain enantiomerically enriched drug precursors and an insect pheromone. Almost stereochemically pure secondary alcohols, used in the synthesis of drugs such as (R)-rasagiline mesylate, (S)-rivastigmine, (R)-chlorphenesin carbamate, and (R)-mexiletine, and the insect pheromone (4S,5R)-sitophilure, were conveniently obtained. The enzymes worked well with ketones containing at least one non-bulky substituent at the carbonyl group. The diverse stereochemical preference of the above five carbonyl reductases was clarified. Copyright © 2017 Elsevier Ltd. All rights reserved.

Determination of the excess noise of avalanche photodiodes integrated in 0.35-μm CMOS technologies

Science.gov (United States)

Jukić, Tomislav; Brandl, Paul; Zimmermann, Horst

2018-04-01

The excess noise of avalanche photodiodes (APDs) integrated in a high-voltage (HV) CMOS process and in a pin-photodiode CMOS process, both with 0.35-μm structure sizes, is described. A precise excess noise measurement technique is applied using a laser source, a spectrum analyzer, a voltage source, a current meter, a cheap transimpedance amplifier, and a personal computer with a MATLAB program. In addition, usage for on-wafer measurements is demonstrated. The measurement technique is verified with a low excess noise APD as a reference device with known ratio k = 0.01 of the impact ionization coefficients. The k-factor of an APD developed in HV CMOS is determined more accurately than known before. In addition, it is shown that the excess noise of the pin-photodiode CMOS APD depends on the optical power for avalanche gains above 35 and that modulation doping can suppress this power dependence. Modulation doping, however, increases the excess noise.

Molecular simulation of excess isotherm and excess enthalpy change in gas-phase adsorption.

Science.gov (United States)

Do, D D; Do, H D; Nicholson, D

2009-01-29

We present a new approach to calculating excess isotherm and differential enthalpy of adsorption on surfaces or in confined spaces by the Monte Carlo molecular simulation method. The approach is very general and, most importantly, is unambiguous in its application to any configuration of solid structure (crystalline, graphite layer or disordered porous glass), to any type of fluid (simple or complex molecule), and to any operating conditions (subcritical or supercritical). The behavior of the adsorbed phase is studied using the partial molar energy of the simulation box. However, to characterize adsorption for comparison with experimental data, the isotherm is best described by the excess amount, and the enthalpy of adsorption is defined as the change in the total enthalpy of the simulation box with the change in the excess amount, keeping the total number (gas + adsorbed phases) constant. The excess quantities (capacity and energy) require a choice of a reference gaseous phase, which is defined as the adsorptive gas phase occupying the accessible volume and having a density equal to the bulk gas density. The accessible volume is defined as the mean volume space accessible to the center of mass of the adsorbate under consideration. With this choice, the excess isotherm passes through a maximum but always remains positive. This is in stark contrast to the literature where helium void volume is used (which is always greater than the accessible volume) and the resulting excess can be negative. Our definition of enthalpy change is equivalent to the difference between the partial molar enthalpy of the gas phase and the partial molar enthalpy of the adsorbed phase. There is no need to assume ideal gas or negligible molar volume of the adsorbed phase as is traditionally done in the literature. We illustrate this new approach with adsorption of argon, nitrogen, and carbon dioxide under subcritical and supercritical conditions.

Bioaccumulation and enantiomeric profiling of organochlorine pesticides and persistent organic pollutants in the killer whale (Orcinus orca) from British and Irish waters

International Nuclear Information System (INIS)

McHugh, Brendan; Law, Robin J.; Allchin, Colin R.; Rogan, Emer; Murphy, Sinead; Foley, M. Barry; Glynn, Denise; McGovern, Evin

2007-01-01

Concentrations and enantiomeric profiles for a range of organochlorine compounds are reported in blubber samples from a number of individual killer whales (Orcinus orca) from British and Irish waters. Elevated contaminant levels and enriched isotopic ratios were determined in one individual whale sampled in the Scottish Western Isles compared to the others suggesting marine mammal based dietary influences. The potential application of isotopic ratios to model contaminant uptake, enantioselective enrichment and accumulation is demonstrated. Data are presented which provide information on enantioselective enrichment factors (EFs) for o,p'-DDT, α-HCH and toxaphene congeners CHB26 and CHB 50. This dataset further improves the current database on reported levels of a number of contaminants and provides additional background information on potential metabolic processes in killer whales from British and Irish waters

Bioaccumulation and enantiomeric profiling of organochlorine pesticides and persistent organic pollutants in the killer whale (Orcinus orca) from British and Irish waters

Energy Technology Data Exchange (ETDEWEB)

McHugh, Brendan [Marine Institute, Rinville, Oranmore, Galway (Ireland)], E-mail: brendan.mchugh@marine.ie; Law, Robin J.; Allchin, Colin R. [Centre for Environment, Fisheries and Aquaculture Science, Cefas Burnham Laboratory, Remembrance Avenue, Burnham on Crouch, Essex CM0 8HA (United Kingdom); Rogan, Emer [Department of Zoology, University College Cork (Ireland); Murphy, Sinead [Department of Zoology, University College Cork (Ireland); Sea Mammal Research Unit, Gatty Marine Laboratory, University of St Andrews, St Andrews, Fife KY16 8LB (United Kingdom); Foley, M. Barry [Dublin Institute of Technology, Kevin Street, Dublin 8 (Ireland); Glynn, Denise; McGovern, Evin [Marine Institute, Rinville, Oranmore, Galway (Ireland)

2007-11-15

Concentrations and enantiomeric profiles for a range of organochlorine compounds are reported in blubber samples from a number of individual killer whales (Orcinus orca) from British and Irish waters. Elevated contaminant levels and enriched isotopic ratios were determined in one individual whale sampled in the Scottish Western Isles compared to the others suggesting marine mammal based dietary influences. The potential application of isotopic ratios to model contaminant uptake, enantioselective enrichment and accumulation is demonstrated. Data are presented which provide information on enantioselective enrichment factors (EFs) for o,p'-DDT, {alpha}-HCH and toxaphene congeners CHB26 and CHB 50. This dataset further improves the current database on reported levels of a number of contaminants and provides additional background information on potential metabolic processes in killer whales from British and Irish waters.

34 CFR 668.166 - Excess cash.

Science.gov (United States)

2010-07-01

... the Secretary for the costs the Secretary incurred in providing that excess cash to the institution... 34 Education 3 2010-07-01 2010-07-01 false Excess cash. 668.166 Section 668.166 Education..., DEPARTMENT OF EDUCATION STUDENT ASSISTANCE GENERAL PROVISIONS Cash Management § 668.166 Excess cash. (a...

Chemoenzymatic one-pot synthesis in an aqueous medium: combination of metal-catalysed allylic alcohol isomerisation-asymmetric bioamination.

Science.gov (United States)

Ríos-Lombardía, Nicolás; Vidal, Cristian; Cocina, María; Morís, Francisco; García-Álvarez, Joaquín; González-Sabín, Javier

2015-07-11

The ruthenium-catalysed isomerisation of allylic alcohols was coupled, for the first time, with asymmetric bioamination in a one-pot process in an aqueous medium. In the cases involving prochiral ketones, the ω-TA exhibited excellent enantioselectivity, identical to that observed in the single step. As a result, amines were obtained from allylic alcohols with high overall yields and excellent enantiomeric excesses.

Excess water dynamics in hydrotalcite: QENS study

Indian Academy of Sciences (India)

dynamics of excess water in hydrotalcite sample with varied content of excess water are reported. Translational motion of excess water can be best described by random transla- tional jump diffusion model. The observed increase in translational diffusivity with increase in the amount of excess water is attributed to the ...

75 FR 30846 - Monthly Report of Excess Income and Annual Report of Uses of Excess Income (Correction)

Science.gov (United States)

2010-06-02

... Income and Annual Report of Uses of Excess Income (Correction) AGENCY: Office of the Chief Information.... Project owners are permitted to retain Excess Income for projects under terms and conditions established by HUD. Owners must request to retain some or all of their Excess Income. The request must be...

7 CFR 985.56 - Excess oil.

Science.gov (United States)

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Excess oil. 985.56 Section 985.56 Agriculture... HANDLING OF SPEARMINT OIL PRODUCED IN THE FAR WEST Order Regulating Handling Volume Limitations § 985.56 Excess oil. Oil of any class in excess of a producer's applicable annual allotment shall be identified as...

Characterization of Mixtures. Part 2: QSPR Models for Prediction of Excess Molar Volume and Liquid Density Using Neural Networks.

Science.gov (United States)

Ajmani, Subhash; Rogers, Stephen C; Barley, Mark H; Burgess, Andrew N; Livingstone, David J

2010-09-17

In our earlier work, we have demonstrated that it is possible to characterize binary mixtures using single component descriptors by applying various mixing rules. We also showed that these methods were successful in building predictive QSPR models to study various mixture properties of interest. Here in, we developed a QSPR model of an excess thermodynamic property of binary mixtures i.e. excess molar volume (V(E) ). In the present study, we use a set of mixture descriptors which we earlier designed to specifically account for intermolecular interactions between the components of a mixture and applied successfully to the prediction of infinite-dilution activity coefficients using neural networks (part 1 of this series). We obtain a significant QSPR model for the prediction of excess molar volume (V(E) ) using consensus neural networks and five mixture descriptors. We find that hydrogen bond and thermodynamic descriptors are the most important in determining excess molar volume (V(E) ), which is in line with the theory of intermolecular forces governing excess mixture properties. The results also suggest that the mixture descriptors utilized herein may be sufficient to model a wide variety of properties of binary and possibly even more complex mixtures. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

10 CFR 904.10 - Excess energy.

Science.gov (United States)

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Excess energy. 904.10 Section 904.10 Energy DEPARTMENT OF ENERGY GENERAL REGULATIONS FOR THE CHARGES FOR THE SALE OF POWER FROM THE BOULDER CANYON PROJECT Power Marketing § 904.10 Excess energy. (a) If excess Energy is determined by the United States to be available...

BENEFITS OF WILDERNESS EXPANSION WITH EXCESS DEMAND FOR INDIAN PEAKS

OpenAIRE

Walsh, Richard G.; Gilliam, Lynde O.

1982-01-01

The contingent valuation approach was applied to the problem of estimating the recreation benefits from alleviating congestion at Indian Peaks wilderness area, Colorado. A random sample of 126 individuals were interviewed while hiking and backpacking at the study site in 1979. The results provide an empirical test and confirmation of the Cesario and Freeman proposals that under conditions of excess recreational demand for existing sites, enhanced opportunities to substitute newly designated s...

Neutron excess generation by fusion neutron source for self-consistency of nuclear energy system

International Nuclear Information System (INIS)

Saito, Masaki; Artisyuk, V.; Chmelev, A.

1999-01-01

The present day fission energy technology faces with the problem of transmutation of dangerous radionuclides that requires neutron excess generation. Nuclear energy system based on fission reactors needs fuel breeding and, therefore, suffers from lack of neutron excess to apply large-scale transmutation option including elimination of fission products. Fusion neutron source (FNS) was proposed to improve neutron balance in the nuclear energy system. Energy associated with the performance of FNS should be small enough to keep the position of neutron excess generator, thus, leaving the role of dominant energy producers to fission reactors. The present paper deals with development of general methodology to estimate the effect of neutron excess generation by FNS on the performance of nuclear energy system as a whole. Multiplication of fusion neutrons in both non-fissionable and fissionable multipliers was considered. Based on the present methodology it was concluded that neutron self-consistency with respect to fuel breeding and transmutation of fission products can be attained with small fraction of energy associated with innovated fusion facilities. (author)

An Extraordinary Accumulation of (-)-Pinoresinol in Cell-Free Extracts of Forsythia intermedia: Evidence for Enantiospecific Reduction of (+)-Pinoresinol

Science.gov (United States)

Katayama, Takeshi; Davin, Laurence B.; Lewis, Norman G.

1992-01-01

Stereoselective and enantiospecific transformation mechanisms in lignan biogenesis are only now yielding to scientific inquiry: it has been shown that soluble cell-free preparations from Forsythia intermedia catalysis the formation of the enantiomerically pure lignan, (-)-secoisolariciresinol, when incubated with coniferyl alcohol in the presence of NAD(P)H and H2O2. Surprisingly, (-)-pinoresinol also accumulates in this soluble cell-free assay mixture in greater than 96% enantiomeric excess, even though it is not the naturally occurring antipode present in Forsythia sp. But these soluble cell-free preparations do not engender stereoselective coupling; instead, racemic pinoresinols are first formed, catalysed by an H2O2-dependent peroxidase reaction. An enantiospecific NAD(P)H reductase then converts (+)- pinoresinol, and not the (-)-antipode, into (-)-secoisolariciresinol. Stereoselective syntheis of(+)-pinoresinol from E-coniferyl alcohol is, however, catalysed by an insoluble enzyme preparation in F. suspensa, obtained following removal of readily soluble and ionically bound enzymes; no exogenously supplied cofactors were required other than oxygen, although the reaction was stimulated by NAD-malate addition. Thus, the overall biochemical pathway to enantiomerically pure (-)-secoisolariciresinol has been delineated.

Does Excessive Pronation Cause Pain?

DEFF Research Database (Denmark)

Mølgaard, Carsten Møller; Olesen Gammelgaard, Christian; Nielsen, R. G.

Excessive pronation could be an inborn abnormality or an acquired foot disorder caused by overuse, inadequate supported shoes or inadequate foot training. When the muscles and ligaments of the foot are insufficient it can cause an excessive pronation of the foot. The current treatment consist...... of antipronation shoes or insoles, which latest was studied by Kulce DG., et al (2007). So far there have been no randomized controlled studies showing methods that the effect of this treatment has not been documented. Therefore the authors can measure the effect of treatments with insoles. Some of the excessive...

A COMPREHENSIVE CENSUS OF NEARBY INFRARED EXCESS STARS

Energy Technology Data Exchange (ETDEWEB)

Cotten, Tara H.; Song, Inseok, E-mail: tara@physast.uga.edu, E-mail: song@physast.uga.edu [Department of Physics and Astronomy, University of Georgia, Athens, GA 30602 (United States)

2016-07-01

The conclusion of the Wide-Field Infrared Survey Explorer ( WISE ) mission presents an opportune time to summarize the history of using excess emission in the infrared as a tracer of circumstellar material and exploit all available data for future missions such as the James Webb Space Telescope . We have compiled a catalog of infrared excess stars from peer-reviewed articles and perform an extensive search for new infrared excess stars by cross-correlating the Tycho-2 and all-sky WISE (AllWISE) catalogs. We define a significance of excess in four spectral type divisions and select stars showing greater than either 3 σ or 5 σ significance of excess in the mid- and far-infrared. Through procedures including spectral energy distribution fitting and various image analyses, each potential excess source was rigorously vetted to eliminate false positives. The infrared excess stars from the literature and the new stars found through the Tycho-2 and AllWISE cross-correlation produced nearly 500 “Prime” infrared excess stars, of which 74 are new sources of excess, and >1200 are “Reserved” stars, of which 950 are new sources of excess. The main catalog of infrared excess stars are nearby, bright, and either demonstrate excess in more than one passband or have infrared spectroscopy confirming the infrared excess. This study identifies stars that display a spectral energy distribution suggestive of a secondary or post-protoplanetary generation of dust, and they are ideal targets for future optical and infrared imaging observations. The final catalogs of stars summarize the past work using infrared excess to detect dust disks, and with the most extensive compilation of infrared excess stars (∼1750) to date, we investigate various relationships among stellar and disk parameters.

Does excessive pronation cause pain?

DEFF Research Database (Denmark)

Olesen, C G; Nielsen, Rasmus Gottschalk N; Rathleff, Michael Skovdal

2008-01-01

Excessive pronation could be an inborn abnormality or an acquired foot disorder caused by overuse, inadequate supported shoes or inadequate foot training. When the muscles and ligaments of the foot are insufficient it can cause an excessive pronation of the foot. The current treatment consist of ...

Evaluation of Excess Heat Utilization in District Heating Systems by Implementing Levelized Cost of Excess Heat

Directory of Open Access Journals (Sweden)

Borna Doračić

2018-03-01

Full Text Available District heating plays a key role in achieving high primary energy savings and the reduction of the overall environmental impact of the energy sector. This was recently recognized by the European Commission, which emphasizes the importance of these systems, especially when integrated with renewable energy sources, like solar, biomass, geothermal, etc. On the other hand, high amounts of heat are currently being wasted in the industry sector, which causes low energy efficiency of these processes. This excess heat can be utilized and transported to the final customer by a distribution network. The main goal of this research was to calculate the potential for excess heat utilization in district heating systems by implementing the levelized cost of excess heat method. Additionally, this paper proves the economic and environmental benefits of switching from individual heating solutions to a district heating system. This was done by using the QGIS software. The variation of different relevant parameters was taken into account in the sensitivity analysis. Therefore, the final result was the determination of the maximum potential distance of the excess heat source from the demand, for different available heat supplies, costs of pipes, and excess heat prices.

Excessive masturbation after epilepsy surgery.

Science.gov (United States)

Ozmen, Mine; Erdogan, Ayten; Duvenci, Sirin; Ozyurt, Emin; Ozkara, Cigdem

2004-02-01

Sexual behavior changes as well as depression, anxiety, and organic mood/personality disorders have been reported in temporal lobe epilepsy (TLE) patients before and after epilepsy surgery. The authors describe a 14-year-old girl with symptoms of excessive masturbation in inappropriate places, social withdrawal, irritability, aggressive behavior, and crying spells after selective amygdalohippocampectomy for medically intractable TLE with hippocampal sclerosis. Since the family members felt extremely embarrassed, they were upset and angry with the patient which, in turn, increased her depressive symptoms. Both her excessive masturbation behavior and depressive symptoms remitted within 2 months of psychoeducative intervention and treatment with citalopram 20mg/day. Excessive masturbation is proposed to be related to the psychosocial changes due to seizure-free status after surgery as well as other possible mechanisms such as Kluver-Bucy syndrome features and neurophysiologic changes associated with the cessation of epileptic discharges. This case demonstrates that psychiatric problems and sexual changes encountered after epilepsy surgery are possibly multifactorial and in adolescence hypersexuality may be manifested as excessive masturbation behavior.

Excess cash holdings and shareholder value

OpenAIRE

Lee, Edward; Powell, Ronan

2011-01-01

We examine the determinants of corporate cash holdings in Australia and the impact on shareholder wealth of holding excess cash. Our results show that a trade-off model best explains the level of a firm’s cash holdings in Australia. We find that 'transitory' excess cash firms earn significantly higher risk-adjusted returns compared to 'persistent' excess cash firms, suggesting that the market penalises firms that hoard cash. The marginal value of cash also declines with larger cash balances, ...

Antidepressant induced excessive yawning and indifference

Directory of Open Access Journals (Sweden)

Bruno Palazzo Nazar

2015-03-01

Full Text Available Introduction Antidepressant induced excessive yawning has been described as a possible side effect of pharmacotherapy. A syndrome of indifference has also been described as another possible side effect. The frequency of those phenomena and their physiopathology are unknown. They are both considered benign and reversible after antidepressant discontinuation but severe cases with complications as temporomandibular lesions, have been described. Methods We report two unprecedented cases in which excessive yawning and indifference occurred simultaneously as side effects of antidepressant therapy, discussing possible physiopathological mechanisms for this co-occurrence. Case 1: A male patient presented excessive yawning (approximately 80/day and apathy after venlafaxine XR treatment. Symptoms reduced after a switch to escitalopram, with a reduction to 50 yawns/day. Case 2: A female patient presented excessive yawning (approximately 25/day and inability to react to environmental stressors with desvenlafaxine. Conclusion Induction of indifference and excessive yawning may be modulated by serotonergic and noradrenergic mechanisms. One proposal to unify these side effects would be enhancement of serotonin in midbrain, especially paraventricular and raphe nucleus.

Physical, clinical, and psychosocial parameters of adolescents with different degrees of excess weight

Directory of Open Access Journals (Sweden)

Vanessa Drieli Seron Antonini

2014-12-01

Full Text Available OBJECTIVE: To compare body composition, hemodynamic parameters, health-related physical fitness, and health-related quality of life of adolescents with anthropometric diagnosis of overweight, obesity, and severe obesity.METHODS: 220 adolescents with excess body weight were enrolled. They were beginners in a intervention program that included patients based on age, availability, presence of excess body weight, place of residence, and agreement to participate in the study. This study collected anthropometric and hemodynamic variables, health-related physical fitness, and health-related quality of life of the adolescents. To compare the three groups according to nutritional status, parametric and non-parametric tests were applied. Significance level was set at p0.05. Body weight, body mass index, waist and hip circumference, and systolic blood pressure increased as degree of excess weightincreased (p<0.05. Dyastolic blood pressure of the severe obesity group was higher than the other groups (p<0.05. There was an association between the degree of excess weight and the prevalence of altered blood pressure (overweight: 12.1%; obesity: 28.1%; severe obesity: 45.5%; p<0.001. The results were similar when genders were analyzed separately.CONCLUSION: Results suggest that overweight adolescents presented similar results compared to obese and severely obese adolescents in most of the parameters analyzed.

Identification and characterization of epoxide hydrolase activity of polycyclic aromatic hydrocarbon-degrading bacteria for biocatalytic resolution of racemic styrene oxide and styrene oxide derivatives.

Science.gov (United States)

Woo, Jung-Hee; Kwon, Tae-Hyung; Kim, Jun-Tae; Kim, Choong-Gon; Lee, Eun Yeol

2013-04-01

A novel epoxide hydrolase (EHase) from polycyclic aromatic hydrocarbon (PAH)-degrading bacteria was identified and characterized. EHase activity was identified in four strains of PAH-degrading bacteria isolated from commercial gasoline and oil-contaminated sediment based on their growth on styrene oxide and its derivatives, such as 2,3- and 4-chlorostyrene oxides, as a sole carbon source. Gordonia sp. H37 exhibited high enantioselective hydrolysis activity for 4-chlorostyrene oxide with an enantiomeric ratio of 27. Gordonia sp. H37 preferentially hydrolyzed the (R)-enantiomer of styrene oxide derivatives resulting in the preparation of a (S)-enantiomer with enantiomeric excess greater than 99.9 %. The enantioselective EHase activity was identified and characterized in various PAH-degrading bacteria, and whole cell Gordonia sp. H37 was employed as a biocatalyst for preparing enantiopure (S)-styrene oxide derivatives.

Phase-Modulated Nonresonant Laser Pulses Can Selectively Convert Enantiomers in a Racemic Mixture

DEFF Research Database (Denmark)

Thomas, Esben Folger; Henriksen, Niels Engholm

2017-01-01

-modulated, nonresonant, linearly polarized Gaussian laser pulses that can selectively deracemize a racemic mixture of 3D-oriented, 3,5-difluoro-3',5'-dibromobiphenyl (F2H3C6-C6H3Br2) molecules, the laser-induced dynamics of which are well studied experimentally. These results strongly suggest that designing a closed......Deracemization occurs when a racemic molecular mixture is transformed into a mixture containing an excess of a single enantiomer. Recent advances in ultrafast laser technology hint at the possibility of using shaped pulses to generate deracemization via selective enantiomeric conversion; however......, experimental implementation remains a challenge and has not yet been achieved. Here we suggest a simple, yet novel approach to laser-induced enantiomeric conversion based on dynamic Stark control. We demonstrate theoretically that current laser and optical technology can be used to generate a pair of phase...

Technologies for utilization of industrial excess heat: Potentials for energy recovery and CO2 emission reduction

International Nuclear Information System (INIS)

Broberg Viklund, Sarah; Johansson, Maria T.

2014-01-01

Highlights: • Technologies for recovery and use of industrial excess heat were investigated. • Heat harvesting, heat storage, heat utilization, and heat conversion technologies. • Heat recovery potential for Gävleborg County in Sweden was calculated. • Effects on global CO 2 emissions were calculated for future energy market scenarios. - Abstract: Industrial excess heat is a large untapped resource, for which there is potential for external use, which would create benefits for industry and society. Use of excess heat can provide a way to reduce the use of primary energy and to contribute to global CO 2 mitigation. The aim of this paper is to present different measures for the recovery and utilization of industrial excess heat and to investigate how the development of the future energy market can affect which heat utilization measure would contribute the most to global CO 2 emissions mitigation. Excess heat recovery is put into a context by applying some of the excess heat recovery measures to the untapped excess heat potential in Gävleborg County in Sweden. Two different cases for excess heat recovery are studied: heat delivery to a district heating system and heat-driven electricity generation. To investigate the impact of excess heat recovery on global CO 2 emissions, six consistent future energy market scenarios were used. Approximately 0.8 TWh/year of industrial excess heat in Gävleborg County is not used today. The results show that with the proposed recovery measures approximately 91 GWh/year of district heating, or 25 GWh/year of electricity, could be supplied from this heat. Electricity generation would result in reduced global CO 2 emissions in all of the analyzed scenarios, while heat delivery to a DH system based on combined heat and power production from biomass would result in increased global CO 2 emissions when the CO 2 emission charge is low

Risk charts to identify low and excessive responders among first-cycle IVF/ICSI standard patients

DEFF Research Database (Denmark)

la Cour Freiesleben, N; Gerds, Thomas Alexander; Forman, Julie Lyng

2011-01-01

Ovarian stimulation carries a risk of either low or excessive ovarian response. The aim was to develop prognostic models for identification of standard (ovulatory and normal basal FSH) patients’ risks of low and excessive response to conventional stimulation for IVF/intracytoplasmic sperm injection....... Prospectively collected data on 276 first-cycle patients treated with 150 IU recombinant FSH (rFSH)/day in a long agonist protocol were analysed. Logistic regression analysis was applied to the outcome variables:low (seven or less follicles) and excessive (20 or more follicles) response. Variables were woman......’s age, menstrual cycle length, weight or body mass index, ovarian volume, antral follicle count (AFC) and basal FSH. The predictive performance of the models was evaluated from the prediction error (Brier score, %) where zero corresponds to a perfect prediction. Model stability was assessed using 1000...

Basic study of cold fusion. 1. The development of excess heat measurement system in electrolysis

International Nuclear Information System (INIS)

Asaoka, Yoshiyuki; Fujita, Tomonari

1994-01-01

We have an opportunity ripe to investigate the cold fusion phenomena. In order to declare the subjects to be examined, the precision calorimetry system was developed to try to reproduce the phenomena. The electrolysis of heavy water with palladium cathode was conducted based on the thought that it is important to confirm the cold fusion phenomena. For precision excess power measurement, the closed cell with recombiner and flow-calorimetry were adopted. The obtained accuracy for the excess power measurement of the system was ±0.2 W at up to 9 W of applied power. This is enough for the excess power reported as the cold fusion phenomena. For farther investigation, measurement of loading ratio of deuterium in the palladium cathode, maintenance of high deuterium loading and analysis of the palladium cathode are to be conducted. (author)

26 CFR 54.4981A-1T - Tax on excess distributions and excess accumulations (temporary).

Science.gov (United States)

2010-04-01

... Revenue Code of 1986, as added by section 1133 of the Tax Reform Act of 1986 (Pub. L. 99-514) (TRA '86...) Determine the value of the individual's adjusted account balance on the next valuation date by adding (or... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Tax on excess distributions and excess...

[Disability attributable to excess weight in Spain].

Science.gov (United States)

Martín-Ramiro, José Javier; Alvarez-Martín, Elena; Gil-Prieto, Ruth

2014-08-19

To estimate the disability attributable to higher than optimal body mass index in the Spanish population in 2006. Excess body weight prevalence data were obtained from the 2006 National Health Survey (NHS), while the prevalence of associated morbidities was extracted from the 2006 NHS and from a national hospital data base. Population attributable fractions were applied and disability attributable was expressed as years life with disability (YLD). In 2006, in the Spanish population aged 35-79 years, 791.650 YLD were lost due to higher than optimal body mass index (46.7% in males and 53.3% in females). Overweight (body mass index 25-29.9) accounted for 45.7% of total YLD. Males YLD were higher than females under 60. The 35-39 quinquennial group showed a difference for males of 16.6% while in the 74-79 group the difference was 23.8% for women. Osteoarthritis and chronic back pain accounted for 60% of YLD while hypertensive disease and type 2 diabetes mellitus were responsible of 37%. Excess body weight is a health risk related to the development of various diseases with an important associated disability burden and social and economical cost. YLD analysis is a useful monitor tool for disease control interventions. Copyright © 2013 Elsevier España, S.L. All rights reserved.

Chemical Composition, Enantiomeric Distribution, and Antifungal Activity of the Oleoresin Essential Oil of Protium amazonicum from Ecuador.

Science.gov (United States)

Satyal, Prabodh; Powers, Chelsea N; Parducci V, Rafael; McFeeters, Robert L; Setzer, William N

2017-09-23

Background: Protium species (Burseraceae) have been used in the treatment of various diseases and conditions such as ulcers and wounds. Methods: The essential oil from the oleoresin of Protium amazonicum was obtained by hydrodistillation and analyzed by GC-MS, GC-FID, and chiral GC-MS. P. amazonicum oleoresin oil was screened for antifungal activity against Candida albicans , Aspergillus niger , and Cryptococcus neoformans . Results: A total of 54 components representing 99.6% of the composition were identified in the oil. The essential oil was dominated by δ-3-carene (47.9%) with lesser quantities of other monoterpenoids α-pinene (4.0%), p -cymene (4.1%), limonene (5.1%), α-terpineol (5.5%) and p -cymen-8-ol (4.8%). Chiral GC-MS revealed most of the monoterpenoids to have a majority of levo enantiomers present with the exceptions of limonene and α-terpineol, which showed a dextro majority. P. amazonicum oleoresin oil showed promising activity against Cryptococcus neoformans , with MIC = 156 μg/mL. Conclusions: This account is the first reporting of both the chemical composition and enantiomeric distribution of the oleoresin essential oil of P. amazonicum from Ecuador. The oil was dominated by (-)-δ-3-carene, and this compound, along with other monoterpenoids, likely accounts for the observed antifungal activity of the oil.

Confirming the appearance of excess success: Reply to van Boxtel and Koch (2016).

Science.gov (United States)

Francis, Gregory

2016-12-01

van Boxtel and Koch (Psychonomic Bulletin & Review. doi: 10.3758/s13423-016-1010-0 , 2016) reported finding problems in the Test for Excess Success (TES) analysis in Francis (Psychonomic Bulletin & Review, 21, 1180-1187, 2014). They argued that their findings undermined the general analysis and the conclusions of the specific TES analysis for their article (van Boxtel & Koch in Psychological Science, 23(4), 410-418, 2012). As shown in this paper, their reported problems reflect misunderstandings about both the general properties of a TES analysis and how it was applied to their specific set of findings. Another look at the findings and theoretical claims in van Boxtel and Koch (Psychological Science, 23(4), 410-418, 2012) confirms the appearance of excess success.

Physical activity and exercise dependence during inpatient treatment of longstanding eating disorders: an exploratory study of excessive and non-excessive exercisers.

Science.gov (United States)

Bratland-Sanda, Solfrid; Sundgot-Borgen, Jorunn; Rø, Øyvind; Rosenvinge, Jan H; Hoffart, Asle; Martinsen, Egil W

2010-04-01

To describe changes in physical activity (PA) and exercise dependence score during treatment of eating disorders (ED), and to explore correlations among changes in PA, exercise motivation, exercise dependence score and ED psychopathology in excessive and non-excessive exercisers. Thirty-eight adult females receiving inpatient treatment for anorexia nervosa, bulimia nervosa or ED not otherwise specified participated in this prospective study. Assessments included accelerometer assessed PA, Exercise Dependence Scale, Reasons for Exercise Inventory, ED Examination, and ED Inventory. Amount of PA was significantly reduced in non-excessive exercisers during treatment, in excessive exercisers there was a trend towards reduced amount of PA from admission to discharge. In excessive exercisers, reduced ED psychopathology was correlated with reduction in exercise dependence score and perceived importance of exercise to regulate negative affects, but not with importance of exercise for weight/appearance. These associations were not found in non-excessive exercisers. Excessive exercise is an important issue in longstanding ED, and the excessive exercising patients need help to develop alternative strategies to regulate negative affects.

Explaining CMS lepton excesses with supersymmetry

CERN Multimedia

CERN. Geneva; Prof. Allanach, Benjamin

2014-01-01

1) Kostas Theofilatos will give an introduction to CMS result 2) Ben Allanach: Several CMS analyses involving di-leptons have recently reported small 2.4-2.8 sigma local excesses: nothing to get too excited about, but worth keeping an eye on nonetheless. In particular, a search in the $lljj p_T$(miss) channel, a search for $W_R$ in the $lljj$ channel and a di-leptoquark search in the $lljj$ channel and $ljj p_T$(miss) channel have all yielded small excesses. We interpret the first excess in the MSSM, showing that the interpretation is viable in terms of other constraints, despite only having squark masses of around 1 TeV. We can explain the last three excesses with a single R-parity violating coupling that predicts a non-zero contribution to the neutrinoless double beta decay rate.

Syndromes associated with nutritional deficiency and excess.

Science.gov (United States)

Jen, Melinda; Yan, Albert C

2010-01-01

Normal functioning of the human body requires a balance between nutritional intake and metabolism, and imbalances manifest as nutritional deficiencies or excess. Nutritional deficiency states are associated with social factors (war, poverty, famine, and food fads), medical illnesses with malabsorption (such as Crohn disease, cystic fibrosis, and after bariatric surgery), psychiatric illnesses (eating disorders, autism, alcoholism), and medications. Nutritional excess states result from inadvertent or intentional excessive intake. Cutaneous manifestations of nutritional imbalance can herald other systemic manifestations. This contribution discusses nutritional deficiency and excess syndromes with cutaneous manifestations of particular interest to clinical dermatologists. Copyright © 2010. Published by Elsevier Inc.

Chirality sensing with stereodynamic copper(I) complexes.

Science.gov (United States)

De Los Santos, Zeus A; Legaux, Nicholas M; Wolf, Christian

2017-11-01

Three Cu(I) complexes derived from stereodynamic diphosphine ligands were synthesized and used for chirality sensing. The coordination of diamines and amino acids to these complexes generates distinct circular dichroism signals. The chiroptical sensor response allows determination of the absolute configuration and the enantiomeric excess of the analyte at low concentrations. This method is operationally simple, fast, and attractive for high-throughput sensing applications. © 2017 Wiley Periodicals, Inc.

Magnetic nanoparticles conjugated to chiral imidazolidinone as recoverable catalyst

Energy Technology Data Exchange (ETDEWEB)

Mondini, Sara [Consiglio Nazionale delle Ricerche, Laboratorio di Nanotecnologie, Istituto di Scienze e Tecnologie Molecolari (Italy); Puglisi, Alessandra; Benaglia, Maurizio, E-mail: maurizio.benaglia@unimi.it; Ramella, Daniela [Università degli Studi di Milano, Dipartimento di Chimica (Italy); Drago, Carmelo [Consiglio Nazionale delle Ricerche, Istituto di Chimica Biomolecolare (Italy); Ferretti, Anna M.; Ponti, Alessandro, E-mail: alessandro.ponti@istm.cnr.it [Consiglio Nazionale delle Ricerche, Laboratorio di Nanotecnologie, Istituto di Scienze e Tecnologie Molecolari (Italy)

2013-11-15

The immobilization of an ad hoc designed chiral imidazolidin-4-one onto iron oxide magnetic nanoparticles (MNPs) is described, to afford MNP-supported MacMillan’s catalyst. Morphological and structural analysis of the materials, during preparation, use, and recycle, has been carried out by transmission electron microscopy. The supported catalyst was tested in the Diels–Alder reaction of cyclopentadiene with cinnamic aldehyde, affording the products in good yields and enantiomeric excesses up to 93 %, comparable to those observed with the non-supported catalyst. Recovery of the chiral catalyst has been successfully performed by simply applying an external magnet to achieve a perfect separation of the MNPs from the reaction product. The recycle of the catalytic system has been also investigated. Noteworthy, this immobilized MacMillan’s catalyst proved to be able to efficiently promote the reaction in pure water.

Magnetic nanoparticles conjugated to chiral imidazolidinone as recoverable catalyst

International Nuclear Information System (INIS)

Mondini, Sara; Puglisi, Alessandra; Benaglia, Maurizio; Ramella, Daniela; Drago, Carmelo; Ferretti, Anna M.; Ponti, Alessandro

2013-01-01

The immobilization of an ad hoc designed chiral imidazolidin-4-one onto iron oxide magnetic nanoparticles (MNPs) is described, to afford MNP-supported MacMillan’s catalyst. Morphological and structural analysis of the materials, during preparation, use, and recycle, has been carried out by transmission electron microscopy. The supported catalyst was tested in the Diels–Alder reaction of cyclopentadiene with cinnamic aldehyde, affording the products in good yields and enantiomeric excesses up to 93 %, comparable to those observed with the non-supported catalyst. Recovery of the chiral catalyst has been successfully performed by simply applying an external magnet to achieve a perfect separation of the MNPs from the reaction product. The recycle of the catalytic system has been also investigated. Noteworthy, this immobilized MacMillan’s catalyst proved to be able to efficiently promote the reaction in pure water

The Palladium-Catalyzed Aerobic Kinetic Resolution of Secondary Alcohols: Reaction Development, Scope, and Applications

KAUST Repository

Ebner, Davidâ C.; Bagdanoff, Jeffreyâ T.; Ferreira, Ericâ M.; McFadden, Ryanâ M.; Caspi, Danielâ D.; Trend, Raissaâ M.; Stoltz, Brianâ M.

2009-01-01

The first palladium-catalyzed enantioselective oxidation of secondary alcohols has been developed, utilizing the readily available diamine (-)-sparteine as a chiral ligand and molecular oxygen as the stoichiometric oxidant. Mechanistic insights regarding the role of the base and hydrogen-bond donors have resulted in several improvements to the original system. Namely, addition of cesium carbonate and tert-butyl alcohol greatly enhances reaction rates, promoting rapid resolutions. The use of chloroform as solvent allows the use of ambient air as the terminal oxidant at 23 degrees C, resulting in enhanced catalyst selectivity. These improved reaction conditions have permitted the successful kinetic resolution of benzylic, allylic, and cyclopropyl secondary alcohols to high enantiomeric excess with good-to-excellent selectivity factors. This catalyst system has also been applied to the desymmetrization of meso-diols, providing high yields of enantioenriched hydroxyketones.

The Palladium-Catalyzed Aerobic Kinetic Resolution of Secondary Alcohols: Reaction Development, Scope, and Applications

KAUST Repository

Ebner, Davidâ C.

2009-12-07

The first palladium-catalyzed enantioselective oxidation of secondary alcohols has been developed, utilizing the readily available diamine (-)-sparteine as a chiral ligand and molecular oxygen as the stoichiometric oxidant. Mechanistic insights regarding the role of the base and hydrogen-bond donors have resulted in several improvements to the original system. Namely, addition of cesium carbonate and tert-butyl alcohol greatly enhances reaction rates, promoting rapid resolutions. The use of chloroform as solvent allows the use of ambient air as the terminal oxidant at 23 degrees C, resulting in enhanced catalyst selectivity. These improved reaction conditions have permitted the successful kinetic resolution of benzylic, allylic, and cyclopropyl secondary alcohols to high enantiomeric excess with good-to-excellent selectivity factors. This catalyst system has also been applied to the desymmetrization of meso-diols, providing high yields of enantioenriched hydroxyketones.

Dead-blow hammer design applied to a calibration target mechanism to dampen excessive rebound

Science.gov (United States)

Lim, Brian Y.

1991-01-01

An existing rotary electromagnetic driver was specified to be used to deploy and restow a blackbody calibration target inside of a spacecraft infrared science instrument. However, this target was much more massive than any other previously inherited design applications. The target experienced unacceptable bounce when reaching its stops. Without any design modification, the momentum generated by the driver caused the target to bounce back to its starting position. Initially, elastomeric dampers were used between the driver and the target. However, this design could not prevent the bounce, and it compromised the positional accuracy of the calibration target. A design that successfully met all the requirements incorporated a sealed pocket 85 percent full of 0.75 mm diameter stainless steel balls in the back of the target to provide the effect of a dead-blow hammer. The energy dissipation resulting from the collision of balls in the pocket successfully dampened the excess momentum generated during the target deployment. The disastrous effects of new requirements on a design with a successful flight history, the modifications that were necessary to make the device work, and the tests performed to verify its functionality are described.

Excessive Pricing and the Prohibition of the Abuse of a Dominant Position

OpenAIRE

Pozdnakova, Alla

2010-01-01

This article contributes to the European debate on exploitative pricing abuses by dominant undertakings. Although it is questionable whether competition policy should interfere with such market behaviour, case law shows that Article 82 EC applies, in principle, to exploitative pricing abuses by dominant undertakings. The legal test for excessive pricing needs further clarification and simplification, although the test must remain sufficiently flexible for application on a case-by-case basis. ...

Tautomerism of 4-hydroxy-2,5-dimethyl-3(2H)-furanone: evidence for its enantioselective biosynthesis.

Science.gov (United States)

Raab, Thomas; Hauck, Tobias; Knecht, Anja; Schmitt, Ulrich; Holzgrabe, Ulrike; Schwab, Wilfried

2003-08-01

Chiral natural flavor compounds exhibit characteristic enantiomeric excesses due to stereoselective, enzymatically catalyzed reactions during biogenesis. Although the enzymatic formation of the strawberry key flavor compound 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF; Furaneol(R)) is anticipated, the naturally occurring compound is racemic. As racemization due to keto-enol-tautomerism of HDMF could account for this observation, HDMF was investigated by (1)H-NMR spectroscopy tracing the exchange of the proton bound to the furanone-ring at C2 with deuteron from the medium (D(2)O). In addition, the racemization rate of HDMF was directly determined by cyclodextrin-modified capillary electrophoresis of enantiomerically enriched HDMF stored at different pH values. Tautomerism and the racemization rate of HDMF was lowest at pH values between 4 and 5. However, tautomerism and thus racemization was catalyzed under stronger acidic conditions (pH 2) and especially at pH values greater than 7, the value published for plant cell cytosol. Approximately 50% of the protons at C2 were exchanged with deuteron within 1 h at pH 7.2. Therefore, in order to demonstrate the enzymatic formation of HDMF, incubation experiments with Zygosaccharomyces rouxii as well as strawberry protein extract were carried out under slightly acidic conditions (pH 5), the most suitable pH value for studies on the enantiomeric ratio of HDMF. In both experiments the formation of enantiomerically enriched HDMF could be demonstrated for the first time, whereas incubation experiments under neutral conditions resulted in the detection of racemic HDMF. Copyright 2003 Wiley-Liss, Inc.

ATLAS Z Excess in Minimal Supersymmetric Standard Model

International Nuclear Information System (INIS)

Lu, Xiaochuan; Terada, Takahiro

2015-06-01

Recently the ATLAS collaboration reported a 3 sigma excess in the search for the events containing a dilepton pair from a Z boson and large missing transverse energy. Although the excess is not sufficiently significant yet, it is quite tempting to explain this excess by a well-motivated model beyond the standard model. In this paper we study a possibility of the minimal supersymmetric standard model (MSSM) for this excess. Especially, we focus on the MSSM spectrum where the sfermions are heavier than the gauginos and Higgsinos. We show that the excess can be explained by the reasonable MSSM mass spectrum.

Bladder calculus presenting as excessive masturbation.

Science.gov (United States)

De Alwis, A C D; Senaratne, A M R D; De Silva, S M P D; Rodrigo, V S D

2006-09-01

Masturbation in childhood is a normal behaviour which most commonly begins at 2 months of age, and peaks at 4 years and in adolescence. However excessive masturbation causes anxiety in parents. We describe a boy with a bladder calculus presenting as excessive masturbation.

Hyperhidrosis (Excessive Sweating)

Science.gov (United States)

... who have this type are otherwise healthy. In medical terminology, the word “primary” means that the cause is not another medical condition. Secondary hyperhidrosis In medical terminology, “secondary” means that the excessive sweating (hyperhidrosis) has ...

Medical Ethics and Protection from Excessive Radiation

International Nuclear Information System (INIS)

Ruzicka, I.

1998-01-01

Among artificial sources of ionic radiation people are most often exposed to those emanating from X-ray diagnostic equipment. However, responsible usage of X-ray diagnostic methods may considerably reduce the general exposure to radiation. A research on rational access to X-ray diagnostic methods conducted at the X-ray Cabinet of the Tresnjevka Health Center was followed by a control survey eight years later of the rational methods applied, which showed that the number of unnecessary diagnostic examining was reduced for 34 % and the diagnostic indications were 10-40 $ more precise. The results therefore proved that radiation problems were reduced accordingly. The measures applied consisted of additional training organized for health care workers and a better education of the population. The basic element was then the awareness of both health care workers and the patients that excessive radiation should be avoided. The condition for achieving this lies in the moral responsibility of protecting the patients' health. A radiologist, being the person that promotes and carries out this moral responsibility, should organize and hold continual additional training of medical doctors, as well as education for the patients, and apply modern equipment. The basis of such an approach should be established by implementing medical ethics at all medical schools and faculties, together with the promotion of a wider intellectual and moral integrity of each medical doctor. (author)

When Does an Immigrant with HIV Represent an Excessive Demand on Canadian Health or Social Services?

Directory of Open Access Journals (Sweden)

KEDNAPA THAVORN

2010-01-01

Full Text Available The Canadian Immigration and Refugee Protection Act of 2001 outlines conditions under which individuals may be granted or denied admission to Canada. The Act stipulates that applications for residence will be rejected if their health is expected to generate excessive demand on Canadian health or social services. The purpose of this paper is to derive a statistical definition of excessive demand and to apply that threshold to persons with HIV who are seeking admission to Canada. The paper demonstrates that the current threshold used by Citizenship and Immigration Canada is much lower than the thresholds that may be derived statistically.

Enantiomeric Profiling of Chiral Pharmacologically Active Compounds in the Environment with the Usage of Chiral Liquid Chromatography 
Coupled with Tandem Mass Spectrometry

Science.gov (United States)

Camacho-Muñoz, Dolores; Petrie, Bruce; Castrignanò, Erika; Kasprzyk-Hordern, Barbara

2016-01-01

The issue of drug chirality is attracting increasing attention among the scientific community. The phenomenon of chirality has been overlooked in environmental research (environmental occurrence, fate and toxicity) despite the great impact that chiral pharmacologically active compounds (cPACs) can provoke on ecosystems. The aim of this paper is to introduce the topic of chirality and its implications in environmental contamination. Special attention has been paid to the most recent advances in chiral analysis based on liquid chromatography coupled with mass spectrometry and the most popular protein based chiral stationary phases. Several groups of cPACs of environmental relevance, such as illicit drugs, human and veterinary medicines were discussed. The increase in the number of papers published in the area of chiral environmental analysis indicates that researchers are actively pursuing new opportunities to provide better understanding of environmental impacts resulting from the enantiomerism of cPACs. PMID:27713682

Excess-electron energy levels, localization and transport in disordered media

International Nuclear Information System (INIS)

Hamill, W.H.

1980-01-01

In disordered dielectrics, the fundamental parameters which control the physics and chemistry of excess electrons are time, temperature and energy or mean scattering distance. Viscosity and hardness do not directly affect the electron affinity of media, the optical spectra, or the chemical reactivity of dry or delocalized electrons or of relaxed localized or trapped electrons. Since the mean scattering distance and the transport mechanism, including barrier height, are fundamental, both liquids and glasses (including polymers) are considered in order to cover the range of relevant information. Based on the above described background, transport, localization, dry electron scavenging, trapped electron scavenging and recombination are explained. There are no available data for the energy of excess dry electrons in the media relative to vacuum in glasses, unfortunately, because of the very small yield of separated charge pairs at cryogenic temperature. Thermoplastic glassy solids provide attractive possibility above 250 K, and deserve consideration as the substitutes for cryogenic glasses. The same consideration applies to the measurements of electron drift mobility, which are essential for the adequate description of electron scavenging. (Wakatsuki, Y.)

Land-mobile satellite excess path loss measurements

Science.gov (United States)

Hess, G. C.

1980-05-01

An experiment conducted with the ATS-6 satellite to determine the additional path loss over free-space loss experienced by land-mobile communication links is described. This excess path loss is measured as a function of 1) local environment, 2) vehicle heading, 3) link frequency, 4) satellite elevation angle, and 5) street side. A statistical description of excess loss developed from the data shows that the first two parameters dominate. Excess path loss on the order of 25 dB is typical in urban situations, but decreases to under 10 dB in suburban/rural areas. Spaced antenna selection diversity is found to provide only a slight decrease (4 dB, typically) in the urban excess path loss observed. Level crossing rates are depressed in satellite links relative to those of Rayleigh-faded terrestrial links, but increases in average fade durations tend to offset that advantage. The measurements show that the excess path loss difference between 860-MHz links and 1550-MHz links is generally negligible.

Chemical and Electrochemical Asymmetric Dihydroxylation of Olefins in I(2)-K(2)CO(3)-K(2)OsO(2)(OH)(4) and I(2)-K(3)PO(4)/K(2)HPO(4)-K(2)OsO(2)(OH)(4) Systems with Sharpless' Ligand.

Science.gov (United States)

Torii, Sigeru; Liu, Ping; Bhuvaneswari, Narayanaswamy; Amatore, Christian; Jutand, Anny

1996-05-03

Iodine-assisted chemical and electrochemical asymmetric dihydroxylation of various olefins in I(2)-K(2)CO(3)-K(2)OsO(2)(OH)(4) and I(2)-K(3)PO(4)/K(2)HPO(4)-K(2)OsO(2)(OH)(4) systems with Sharpless' ligand provided the optically active glycols in excellent isolated yields and high enantiomeric excesses. Iodine (I(2)) was used stoichiometrically for the chemical dihydroxylation, and good results were obtained with nonconjugated olefins in contrast to the case of potassium ferricyanide as a co-oxidant. The potentiality of I(2) as a co-oxidant under stoichiometric conditions has been proven to be effective as an oxidizing mediator in electrolysis systems. Iodine-assisted asymmetric electro-dihydroxylation of olefins in either a t-BuOH/H(2)O(1/1)-K(2)CO(3)/(DHQD)(2)PHAL-(Pt) or t-BuOH/H(2)O(1/1)-K(3)PO(4)/K(2)HPO(4)/(DHQD)(2)PHAL-(Pt) system in the presence of potassium osmate in an undivided cell was investigated in detail. Irrespective of the substitution pattern, all the olefins afforded the diols in high yields and excellent enantiomeric excesses. A plausible mechanism is discussed on the basis of cyclic voltammograms as well as experimental observations.

Fabrication of Supramolecular Chirality from Achiral Molecules at the Liquid/Liquid Interface Studied by Second Harmonic Generation.

Science.gov (United States)

Lin, Lu; Zhang, Zhen; Guo, Yuan; Liu, Minghua

2018-01-09

We present the investigation into the supramolecular chirality of 5-octadecyloxy-2-(2-pyridylazo)phenol (PARC18) at water/1,2-dichloroethane interface by second harmonic generation (SHG). We observe that PARC18 molecules form supramolecular chirality through self-assembly at the liquid/liquid interface although they are achiral molecules. The bulk concentration of PARC18 in the organic phase has profound effects on the supramolecular chirality. By increasing bulk concentration, the enantiomeric excess at the interface first grows and then decreases until it eventually vanishes. Further analysis reveals that the enantiomeric excess is determined by the twist angle of PARC18 molecules at the interface rather than their orientational angle. At lower and higher bulk concentrations, the average twist angle of PARC18 molecules approaches zero, and the assemblies are achiral; whereas at medium bulk concentrations, the average twist angle is nonzero, so that the assemblies show supramolecular chirality. We also estimate the coverage of PARC18 molecules at the interface versus the bulk concentration and fit it to Langmuir adsorption model. The result indicates that PARC18 assemblies show strongest supramolecular chirality in a half-full monolayer. These findings highlight the opportunities for precise control of supramolecular chirality at liquid/liquid interfaces by manipulating the bulk concentration.

Evaluation of the amount of excess cement around the margins of cement-retained dental implant restorations: the effect of the cement application method.

Science.gov (United States)

Chee, Winston W L; Duncan, Jesse; Afshar, Manijeh; Moshaverinia, Alireza

2013-04-01

Complete removal of excess cement from subgingival margins after cementation of implant-supported restorations has been shown to be unpredictable. Remaining cement has been shown to be associated with periimplant inflammation and bleeding. The purpose of this study was to investigate and compare the amount of excess cement after cementation with 4 different methods of cement application for cement-retained implant-supported restorations. Ten implant replicas/abutments (3i) were embedded in acrylic resin blocks. Forty complete veneer crowns (CVCs) were fabricated by waxing onto the corresponding plastic waxing sleeves. The wax patterns were cast and the crowns were cemented to the implant replicas with either an interim (Temp Bond) or a definitive luting agent (FujiCEM). Four methods of cement application were used for cementation: Group IM-Cement applied on the internal marginal area of the crown only; Group AH-Cement applied on the apical half of the axial walls of the crown; Group AA-Cement applied to all axial walls of the interior surface of the crown, excluding the occlusal surface; and Group PI-Crown filled with cement then seated on a putty index formed to the internal configuration of the restoration (cementation device) (n=10). Cement on the external surfaces was removed before seating the restoration. Cement layers were applied on each crown, after which the crown was seated under constant load (80 N) for 10 minutes. The excess cement from each specimen was collected and measured. One operator performed all the procedures. Results for the groups were compared, with 1 and 2-way ANOVA and the Tukey multiple range test (α=.05). No significant difference in the amount of excess/used cement was observed between the 2 different types of cements (P=.1). Group PI showed the least amount of excess cement in comparison to other test groups (P=.031). No significant difference was found in the amount of excess cement among groups MI, AH, and AA. Group AA showed the

Industrial excess heat for district heating in Denmark

International Nuclear Information System (INIS)

Bühler, Fabian; Petrović, Stefan; Karlsson, Kenneth; Elmegaard, Brian

2017-01-01

Highlights: •Method for utilisation potential of industrial excess heat for district heating. •Industrial excess heat from thermal processes is quantified at single production units. •Linking of industrial excess heat sources and district heating demands done in GIS. •Excess heat recovery using direct heat transfer and heat pumps. •5.1% of the Danish district heating demand could be supplied by industrial excess heat. -- Abstract: Excess heat is available from various sources and its utilisation could reduce the primary energy use. The accessibility of this heat is however dependent amongst others on the source and sink temperature, amount and potential users in its vicinity. In this work a new method is developed which analyses excess heat sources from the industrial sector and how they could be used for district heating. This method first allocates excess heat to single production units by introducing and validating a new approach. Spatial analysis of the heat sources and consumers are then performed to evaluate the potential for using them for district heating. In this way the theoretical potential of using the excess heat for covering the heating demand of buildings is determined. Through the use of industry specific temperature profiles the heat usable directly or via heat pumps is further found. A sensitivity analysis investigates the impact of future energy efficiency measures in the industry, buildings and the district heating grid on the national potential. The results show that for the case study of Denmark, 1.36 TWh of district heat could be provided annually with industrial excess heat from thermal processes which equals 5.1% of the current demand. More than half of this heat was found to be usable directly, without the need for a heat pump.

2-Amino-3-(3-hydroxy-1,2,5-thiadiazol-4-yl)propionic acid

DEFF Research Database (Denmark)

Johansen, Tommy N; Janin, Yves L; Nielsen, Birgitte

2002-01-01

In order to identify new subtype-selective (S)-glutamate (Glu) receptor ligands we have synthesized (RS)-2-amino-3-(3-hydroxy-1,2,5-thiadiazol-4-yl)propionic acid [(RS)-TDPA]. Resolution of (RS)-TDPA by chiral chromatography was performed using a Crownpac CR(+) column affording (R)- and (S......)-TDPA of high enantiomeric purity (enantiomeric excess=99.9%). An X-ray crystallographic analysis revealed that the early eluting enantiomer has R-configuration. Both enantiomers showed high affinity as well as high agonist activity at (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA...... a remarkably low AMPA receptor stereoselectivity, (S)-TDPA showing the highest affinity and (R)-TDPA the most potent agonist activity. In addition, (S)-TDPA was shown to interact with synaptosomal Glu uptake sites displacing [(3)H](R)-aspartic acid (IC(50 ) approximately 390 microM). An enantiospecific...

Study on classical and excess eddy currents losses of Terfenol-D

Energy Technology Data Exchange (ETDEWEB)

Talebian, Soheil; Hojjat, Yousef [Department of Mechanical Engineering, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Ghodsi, Mojtaba [Department of Mechanical and Industrial Engineering, Sultan Qaboos University, Muscat (Oman); Karafi, Mohammad Reza [Department of Mechanical Engineering, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

2015-08-15

In the present paper, classical and excess eddy currents losses of Terfenol-D are studied and effects of magnetic field frequency, peak of magnetic flux density and diameter of Terfenol-D on the eddy currents losses are investigated. To provide reliable data for the purpose of the paper, an experimental laboratory is fabricated and used to obtain major and minor hysteresis loops of Terfenol-D at different frequencies. In theoretical study, initially an analytical model based on uniform distribution of magnetic flux is developed which yields to calculation of classical eddy currents losses. Then, another eddy currents model based on non-uniform distribution of magnetic flux and nonlinear diffusion of electromagnetic fields is presented. The difference between output values of the two models is identified as excess eddy currents losses. Obtained results show that the values of excess losses are generally larger than classical losses and applying just classical model leads to wrong calculation of actual value of eddy currents losses. For the results obtained from two above models, empirical models with respect to the magnetic field frequency and the peak value of magnetic flux density are achieved which can predict the eddy currents losses precisely. To validate the empirical relations, experiments are repeated at a new frequency and values of power losses calculated from analytical equations are compared with the predicted values of the empirical models. The results point towards possibility to use the obtained empirical relations in order to calculate the classical and excess eddy currents losses of Terfenol-D at the frequencies below 200 Hz and different values of magnetic flux density. - Highlights: • Classical eddy currents loss of Terfenol-D is studied using Maxwell's laws. • Excess eddy currents loss of Terfenol-D is studied using Mayergoyz nonlinear model. • Effects of Terfenol-D geometry on the eddy currents losses are investigated. • Power

Understanding Excess Emissions from Industrial Facilities: Evidence from Texas.

Science.gov (United States)

Zirogiannis, Nikolaos; Hollingsworth, Alex J; Konisky, David M

2018-03-06

We analyze excess emissions from industrial facilities in Texas using data from the Texas Commission on Environmental Quality. Emissions are characterized as excess if they are beyond a facility's permitted levels and if they occur during startups, shutdowns, or malfunctions. We provide summary data on both the pollutants most often emitted as excess emissions and the industrial sectors and facilities responsible for those emissions. Excess emissions often represent a substantial share of a facility's routine (or permitted) emissions. We find that while excess emissions events are frequent, the majority of excess emissions are emitted by the largest events. That is, the sum of emissions in the 96-100th percentile is often several orders of magnitude larger than the remaining excess emissions (i.e., the sum of emissions below the 95th percentile). Thus, the majority of events emit a small amount of pollution relative to the total amount emitted. In addition, a small group of high emitting facilities in the most polluting industrial sectors are responsible for the vast majority of excess emissions. Using an integrated assessment model, we estimate that the health damages in Texas from excess emissions are approximately $150 million annually.

A spectral route to determining chirality

DEFF Research Database (Denmark)

Pedersen, Jesper Goor; Mortensen, Asger

2009-01-01

We show how one-dimensional structured media can be used to measure chirality, via the spectral shift of the photonic band gap edges. Analytically, we show that a chiral contrast can, in some cases, be mapped unto an index contrast, thereby greatly simplifying the analysis of such structures. Using...... this mapping, we derive a first-order shift of the band gap edges with chirality. Potentially, this effect could be used for measuring enantiomeric excess....

Lipase-catalyzed highly enantioselective kinetic resolution of boron-containing chiral alcohols.

Science.gov (United States)

Andrade, Leandro H; Barcellos, Thiago

2009-07-16

The first application of enzymes as catalysts to obtain optically pure boron compounds is described. The kinetic resolution of boron-containing chiral alcohols via enantioselective transesterification catalyzed by lipases was studied. Aromatic, allylic, and aliphatic secondary alcohols containing a boronate ester or boronic acid group were resolved by lipase from Candida antartica (CALB), and excellent E values (E > 200) and high enantiomeric excesses (up to >99%) of both remaining substrates and acetylated product were obtained.

Excessive Testing and Pupils in the Public Schools

Science.gov (United States)

Ediger, Marlow

2017-01-01

This article explores the question of excessive testing in public schools, its value in the educational process, and the impact that excessive testing may have on the student and the family unit. While assessments are valuable when used properly, excessive testing may lead to problems with unforeseen consequences.

Can we determine what controls the spatio-temporal distribution of d-excess and 17O-excess in precipitation using the LMDZ general circulation model?

Directory of Open Access Journals (Sweden)

C. Risi

2013-09-01

Full Text Available Combined measurements of the H218O and HDO isotopic ratios in precipitation, leading to second-order parameter D-excess, have provided additional constraints on past climates compared to the H218O isotopic ratio alone. More recently, measurements of H217O have led to another second-order parameter: 17O-excess. Recent studies suggest that 17O-excess in polar ice may provide information on evaporative conditions at the moisture source. However, the processes controlling the spatio-temporal distribution of 17O-excess are still far from being fully understood. We use the isotopic general circulation model (GCM LMDZ to better understand what controls d-excess and 17O-excess in precipitation at present-day (PD and during the last glacial maximum (LGM. The simulation of D-excess and 17O-excess is evaluated against measurements in meteoric water, water vapor and polar ice cores. A set of sensitivity tests and diagnostics are used to quantify the relative effects of evaporative conditions (sea surface temperature and relative humidity, Rayleigh distillation, mixing between vapors from different origins, precipitation re-evaporation and supersaturation during condensation at low temperature. In LMDZ, simulations suggest that in the tropics convective processes and rain re-evaporation are important controls on precipitation D-excess and 17O-excess. In higher latitudes, the effect of distillation, mixing between vapors from different origins and supersaturation are the most important controls. For example, the lower d-excess and 17O-excess at LGM simulated at LGM are mainly due to the supersaturation effect. The effect of supersaturation is however very sensitive to a parameter whose tuning would require more measurements and laboratory experiments. Evaporative conditions had previously been suggested to be key controlling factors of d-excess and 17O-excess, but LMDZ underestimates their role. More generally, some shortcomings in the simulation of 17O-excess

New vector bosons and the diphoton excess

Directory of Open Access Journals (Sweden)

Jorge de Blas

2016-08-01

Full Text Available We consider the possibility that the recently observed diphoton excess at ∼750 GeV can be explained by the decay of a scalar particle (φ to photons. If the scalar is the remnant of a symmetry-breaking sector of some new gauge symmetry, its coupling to photons can be generated by loops of the charged massive vectors of the broken symmetry. If these new W′ vector bosons carry color, they can also generate an effective coupling to gluons. In this case the diphoton excess could be entirely explained in a simplified model containing just φ and W′. On the other hand, if W′ does not carry color, we show that, provided additional colored particles exist to generate the required φ to gluon coupling, the diphoton excess could be explained by the same W′ commonly invoked to explain the diboson excess at ∼2 TeV. We also explore possible connections between the diphoton and diboson excesses with the anomalous tt¯ forward–backward asymmetry.

Independent functional connectivity networks underpin food and monetary reward sensitivity in excess weight.

Science.gov (United States)

Verdejo-Román, Juan; Fornito, Alex; Soriano-Mas, Carles; Vilar-López, Raquel; Verdejo-García, Antonio

2017-02-01

Overvaluation of palatable food is a primary driver of obesity, and is associated with brain regions of the reward system. However, it remains unclear if this network is specialized in food reward, or generally involved in reward processing. We used functional magnetic resonance imaging (fMRI) to characterize functional connectivity during processing of food and monetary rewards. Thirty-nine adults with excess weight and 37 adults with normal weight performed the Willingness to Pay for Food task and the Monetary Incentive Delay task in the fMRI scanner. A data-driven graph approach was applied to compare whole-brain, task-related functional connectivity between groups. Excess weight was associated with decreased functional connectivity during the processing of food rewards in a network involving primarily frontal and striatal areas, and increased functional connectivity during the processing of monetary rewards in a network involving principally frontal and parietal areas. These two networks were topologically and anatomically distinct, and were independently associated with BMI. The processing of food and monetary rewards involve segregated neural networks, and both are altered in individuals with excess weight. Copyright © 2016 Elsevier Inc. All rights reserved.

ON INFRARED EXCESSES ASSOCIATED WITH Li-RICH K GIANTS

Energy Technology Data Exchange (ETDEWEB)

Rebull, Luisa M. [Spitzer Science Center (SSC) and Infrared Science Archive (IRSA), Infrared Processing and Analysis Center - IPAC, 1200 E. California Blvd., California Institute of Technology, Pasadena, CA 91125 (United States); Carlberg, Joleen K. [NASA Goddard Space Flight Center, Code 667, Greenbelt, MD 20771 (United States); Gibbs, John C.; Cashen, Sarah; Datta, Ashwin; Hodgson, Emily; Lince, Megan [Glencoe High School, 2700 NW Glencoe Rd., Hillsboro, OR 97124 (United States); Deeb, J. Elin [Bear Creek High School, 9800 W. Dartmouth Pl., Lakewood, CO 80227 (United States); Larsen, Estefania; Altepeter, Shailyn; Bucksbee, Ethan; Clarke, Matthew [Millard South High School, 14905 Q St., Omaha, NE 68137 (United States); Black, David V., E-mail: rebull@ipac.caltech.edu [Walden School of Liberal Arts, 4230 N. University Ave., Provo, UT 84604 (United States)

2015-10-15

Infrared (IR) excesses around K-type red giants (RGs) have previously been discovered using Infrared Astronomy Satellite (IRAS) data, and past studies have suggested a link between RGs with overabundant Li and IR excesses, implying the ejection of circumstellar shells or disks. We revisit the question of IR excesses around RGs using higher spatial resolution IR data, primarily from the Wide-field Infrared Survey Explorer. Our goal was to elucidate the link between three unusual RG properties: fast rotation, enriched Li, and IR excess. Our sample of RGs includes those with previous IR detections, a sample with well-defined rotation and Li abundance measurements with no previous IR measurements, and a large sample of RGs asserted to be Li-rich in the literature; we have 316 targets thought to be K giants, about 40% of which we take to be Li-rich. In 24 cases with previous detections of IR excess at low spatial resolution, we believe that source confusion is playing a role, in that either (a) the source that is bright in the optical is not responsible for the IR flux, or (b) there is more than one source responsible for the IR flux as measured in IRAS. We looked for IR excesses in the remaining sources, identifying 28 that have significant IR excesses by ∼20 μm (with possible excesses for 2 additional sources). There appears to be an intriguing correlation in that the largest IR excesses are all in Li-rich K giants, though very few Li-rich K giants have IR excesses (large or small). These largest IR excesses also tend to be found in the fastest rotators. There is no correlation of IR excess with the carbon isotopic ratio, {sup 12}C/{sup 13}C. IR excesses by 20 μm, though relatively rare, are at least twice as common among our sample of Li-rich K giants. If dust shell production is a common by-product of Li enrichment mechanisms, these observations suggest that the IR excess stage is very short-lived, which is supported by theoretical calculations. Conversely, the

Two-state model of excess electron relaxation and geminate recombination in water and aqueous solutions

International Nuclear Information System (INIS)

Fedorenko, S.G.

2010-01-01

Graphical abstract: After photo-induced ionization a free electron suffers a quick conversion to a solvated state, and then recombines with the parent atom or ion. However, high mobility and reactivity of a free electron can allow the electron to delocalize and recombine in the free state. The theory of two channel processes of geminate electron recombination is developed and applied to the experiment of three-pulse generation of excess electrons in water. - Abstract: After photo-induced ionization a free electron suffers a quick conversion to a solvated state, and then can recombine with the parent atom or ion. However, high mobility and reactivity of a free electron can allow the electron to delocalize and recombine in the free state. The theory of two channel processes of geminate electron recombination is developed here for the general type of the Markovian motion of reactants. A contact model is used for analytical solution of the problem of geminate recombination of neutral and charged reactants. The theory is applied to the experiment of three-pulse generation of excess electrons in water.

31 CFR 353.12 - Disposition of excess.

Science.gov (United States)

2010-07-01

... necessary to adjust the excess. Instructions for adjustment of the excess can be obtained by email at [email protected] or by writing to Bureau of the Public Debt, Parkersburg, WV 26106-1328. [68 FR 24805...

The Role of Androgen Excess in Metabolic Dysfunction in Women : Androgen Excess and Female Metabolic Dysfunction.

Science.gov (United States)

Escobar-Morreale, Héctor F

2017-01-01

Polycystic ovary syndrome (PCOS) is characterized by the association of androgen excess with chronic oligoovulation and/or polycystic ovarian morphology, yet metabolic disorders and classic and nonclassic cardiovascular risk factors cluster in these women from very early in life. This chapter focuses on the mechanisms underlying the association of PCOS with metabolic dysfunction, focusing on the role of androgen excess on the development of visceral adiposity and adipose tissue dysfunction.

Quantifying recycled moisture fraction in precipitation of an arid region using deuterium excess

Directory of Open Access Journals (Sweden)

Yanlong Kong

2013-01-01

Full Text Available Terrestrial moisture recycling by evapotranspiration has recently been recognised as an important source of precipitation that can be characterised by its isotopic composition. Up to now, this isotope technique has mainly been applied to moisture recycling in some humid regions, including Brazil, Great Lakes in North America and the European Alps. In arid and semi-arid regions, the contribution of transpiration by plants to local moisture recycling can be small, so that evaporation by bare soil and surface water bodies dominates. Recognising that the deuterium excess (d-excess of evaporated moisture is significantly different from that of the original water, we made an attempt to use this isotopic parameter for estimating moisture recycling in the semi-arid region of Eastern Tianshan, China. We measured the d-excess of samples taken from individual precipitation events during a hydrological year from 2003 to 2004 at two Tianshan mountain stations, and we used long-term monthly average values of the d-excess for the station Urumqi, which are available from the International Atomic Energy Agency–World Meteorological Organization (IAEA–WMO Global Network of Isotopes in Precipitation (GNIP. Since apart from recycling of moisture from the ground, sub-cloud evaporation of falling raindrops also affects the d-excess of precipitation, the measured values had to be corrected for this evaporation effect. For the selected stations, the sub-cloud evaporation was found to change between 0.1 and 3.8%, and the d-excess decreased linearly with increasing sub-cloud evaporation at about 1.1‰ per 1% change of sub-cloud evaporation. Assuming simple mixing between advected and recycled moisture, the recycled fraction in precipitation has been estimated to be less than 2.0±0.6% for the Tianshan mountain stations and reach values up to 15.0±0.7% in the Urumqi region. The article includes a discussion of these findings in the context of water cycling in the

Excess Gibbs energy for six binary solid solutions of molecularly simple substances

Energy Technology Data Exchange (ETDEWEB)

Lobo, L J; Staveley, L A.K.

1985-01-01

In this paper we apply the method developed in a previous study of Ar + CH/sub 4/ to the evaluation of the excess Gibbs energy G /SUP E.S/ for solid solutions of two molecularly simple components. The method depends on combining information on the excess Gibbs energy G /SUP E.L/ for the liquid mixture of the two components with a knowledge of the (T, x) solid-liquid phase diagram. Certain thermal properties o the pure substances are also needed. G /SUP E.S/ has been calculated for binary mixtures of Ar + Kr, Kr + CH/sub 4/, CO + N/sub 2/, Kr + Xe, Ar + N/sub 2/, and Ar + CO. In general, but not always, the solid mixtures are more non-ideal than the liquid mixtures of the same composition at the same temperature. Except for the Kr + CH/sub 4/ system, the ratio r = G /SUP E.S/ /G /SUP E.L/ is larger the richer the solution in the component with the smaller molecules.

Seasonal characteristics and current sources of OCPs and PCBs and enantiomeric signatures of chiral OCPs in the atmosphere of Vietnam.

Science.gov (United States)

Wang, Weitao; Wang, Yinghui; Zhang, Ruijie; Wang, Shaopeng; Wei, Chaoshuai; Chaemfa, Chakra; Li, Jun; Zhang, Gan; Yu, Kefu

2016-01-15

Passive air samplers (PAS) were deployed concurrently at 15 locations (nine urban sites and six rural sites) in Vietnam and exposed for approximately 6 weeks from June 26, 2012 to August 26, 2012 and from December 8, 2012 to February 8, 2013. The concentration, composition and enantiomeric signatures of the target compound and Air Mass Backward Trajectories of the 15 sampling sites are presented and discussed in this study. Relatively clean air mass from ocean and similar concentrations and composition of POPs between the south and north of Vietnam indicate that local emissions is most likely the major source of POPs in Vietnam. Technical DDT and technical HCH were widely used in Vietnam and corresponding quantitative data suggests the sporadic use. The preferential degradation of (+)-α-HCH was found in all sampling sites, which could be a regional characteristic of Vietnam. High trans-/cis-chlordane (TC/CC) ratios indicate the current use of technical chlordane for termite control. PCA estimated that main source of PCBs present in the atmosphere of Vietnam was uncontrolled discarded e-waste. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis and optical properties of enantiomeric cinchonidine/cinchonine-terpyridine derivatives and their metal complexes

International Nuclear Information System (INIS)

Wang, Hui-Ting; Wu, Wen-Jie; Liu, Jiang; Chen, Meng; Qian, Dong-Jin; Zhang, Li; Liu, Minghua

2016-01-01

We report here the synthesis and spectroscopic properties of two enantiomeric chiral tridentate ligands (TPyCCD and TPyCCN) composed of terpyridine (TPy) and cinchonidine (CCD) or cinchonine (CCN) substituent, as well as their metal complexes with Zn 2+ , Fe 2+ , Eu 3+ , and Tb 3+ ions. For the pure ligands, the fluorescent emission intensity increased as their concentrations increased in the dilute solutions, but they decreased when the concentrations were greater than 6.9×10 −6 mol/l due to concentration quenching. No significant influence on ligand luminescence was observed for the Zn 2+ /Fe 2+ –TPyCCD and –TPyCCN metal complexes. Their lanthanide (Eu 3+ and Tb 3+ ) complexes displayed both ligand and lanthanide ion emissions, suggesting that the excited energy of both ligands could be transferred to the central Eu 3+ and Tb 3+ ions. Mirror-image circular dichroism spectra were recorded, with several signals centered at about 230, 250–270, 296, and 320 nm; the first ones corresponded to the chiral CCD and CCN substituents, while the latter ones corresponded to the TPy substituent and the metal–TPy (M-TPy) coordination units. It is suggested that the chirality of TPy and the metal complexes was induced by the coexisting chiral CCD and CCN substituents. In addition, due to formation of the metal complexes, the relative intensity of the chiral signals of M–TPy coordination units was enhanced at about 320 nm. - Highlights: • Cinchona alkaloid-terpyridine derivatives and metal complexes were prepared. • Cinchona alkaloid-terpyridine derivatives gave off luminescence at 362 nm. • Ligand excited energy could efficiently transferred to lanthanide ions. • Chirality of terpyridine and metal complexes was induced.

Excess costs of social anxiety disorder in Germany.

Science.gov (United States)

Dams, Judith; König, Hans-Helmut; Bleibler, Florian; Hoyer, Jürgen; Wiltink, Jörg; Beutel, Manfred E; Salzer, Simone; Herpertz, Stephan; Willutzki, Ulrike; Strauß, Bernhard; Leibing, Eric; Leichsenring, Falk; Konnopka, Alexander

2017-04-15

Social anxiety disorder is one of the most frequent mental disorders. It is often associated with mental comorbidities and causes a high economic burden. The aim of our analysis was to estimate the excess costs of patients with social anxiety disorder compared to persons without anxiety disorder in Germany. Excess costs of social anxiety disorder were determined by comparing two data sets. Patient data came from the SOPHO-NET study A1 (n=495), whereas data of persons without anxiety disorder originated from a representative phone survey (n=3213) of the general German population. Missing data were handled by "Multiple Imputation by Chained Equations". Both data sets were matched using "Entropy Balancing". Excess costs were calculated from a societal perspective for the year 2014 using general linear regression with a gamma distribution and log-link function. Analyses considered direct costs (in- and outpatient treatment, rehabilitation, and professional and informal care) and indirect costs due to absenteeism from work. Total six-month excess costs amounted to 451€ (95% CI: 199€-703€). Excess costs were mainly caused by indirect excess costs due to absenteeism from work of 317€ (95% CI: 172€-461€), whereas direct excess costs amounted to 134€ (95% CI: 110€-159€). Costs for medication, unemployment and disability pension was not evaluated. Social anxiety disorder was associated with statistically significant excess costs, in particular due to indirect costs. As patients in general are often unaware of their disorder or its severity, awareness should be strengthened. Prevention and early treatment might reduce long-term indirect costs. Copyright © 2017 Elsevier B.V. All rights reserved.

Excess Volumes and Excess Isentropic Compressibilities of Binary Liquid Mixtures of Trichloroethylene with Esters at 303.15 K

Science.gov (United States)

Ramanaiah, S.; Rao, C. Narasimha; Nagaraja, P.; Venkateswarlu, P.

2015-11-01

Exces volumes, VE, and excess isentropic compressibilities, κSE, have been reported as a function of composition for binary liquid mixtures of trichloroethylene with ethyl acetate, n-propyl acetate, and n-butyl acetate at 303.15 K. Isentropic compressibilities are calculated using measured sound speeds and density data for pure components and for binary mixtures. Excess volumes and excess isentropic compressibilities are found to be negative for the three systems studied over the entire composition range at 303.15 K, whereas these values become more negative with an increase of carbon chain length. The results are discussed in terms of intermolecular interactions between unlike molecules.

Energetics and dynamics of excess electrons in simple fluids

International Nuclear Information System (INIS)

Space, B.

1992-01-01

Excess electronic dynamical and equilibrium properties are modeled in both polarizable and nonpolarizable noble gas fluids. Explicit dynamical calculations are carried out for excess electrons in fluid helium, where excess electronic eigenstates are localized. Energetics and dynamics are considered for fluids which span the entire range of polarizability present in the rare gases. Excess electronic eigenstates and eigenvalues are calculated for fluids of helium, argon and xenon. Both equilibrium and dynamical information is obtained from the calculation of these wavefunctions. A surface hopping trajectory method for studying nonadiabatic excess electronic relaxation in condensed systems is used to explore the nonadiabatic relaxation after photoexciting an equilibrated excess electron in dense fluid helium. The different types on nonadiabatic phenomena which are important in excess electronic relaxation are surveyed. The same surface hopping trajectory method is also used to study the rapid nonadiabatic relaxation after an excess electron is injected into unperturbed fluid helium. Several distinctively different relaxation processes, characterized by their relative importance at different times during the relaxation to a localized equilibrium state, are detailed. Though the dynamical properties of excess electrons under the conditions considered here have never been studied before, the behavior is remarkably similar to that observed in both experimental and theoretical studies of electron hydration dynamics, indicating that the processes described may be very general relaxation mechanisms for localization and trapping in fluids. Additionally, ground state energies of an excess electron, e 0 , are computed as a function of solvent density using model electron-atom pseudopotentials in fluid helium, argon, and xenon. The nonuniqueness of the pseudopotential description of electron-molecule interactions is demonstrated

Measuring excess capital capacity in agricultural production

NARCIS (Netherlands)

Zhengfei, G.; Kumbhakar, S.C.; Myers, R.J.; Oude Lansink, A.G.J.M.

2009-01-01

We introduce the concept "excess capital capacity" and employ a stochastic input requirement frontier to measure excess capital capacity in agricultural production. We also propose a two-step estimation method that allows endogenous regressors in stochastic frontier models. The first step uses

Measuring excess free energies of self-assembled membrane structures.

Science.gov (United States)

Norizoe, Yuki; Daoulas, Kostas Ch; Müller, Marcus

2010-01-01

Using computer simulation of a solvent-free, coarse-grained model for amphiphilic membranes, we study the excess free energy of hourglass-shaped connections (i.e., stalks) between two apposed bilayer membranes. In order to calculate the free energy by simulation in the canonical ensemble, we reversibly transfer two apposed bilayers into a configuration with a stalk in three steps. First, we gradually replace the intermolecular interactions by an external, ordering field. The latter is chosen such that the structure of the non-interacting system in this field closely resembles the structure of the original, interacting system in the absence of the external field. The absence of structural changes along this path suggests that it is reversible; a fact which is confirmed by expanded-ensemble simulations. Second, the external, ordering field is changed as to transform the non-interacting system from the apposed bilayer structure to two-bilayers connected by a stalk. The final external field is chosen such that the structure of the non-interacting system resembles the structure of the stalk in the interacting system without a field. On the third branch of the transformation path, we reversibly replace the external, ordering field by non-bonded interactions. Using expanded-ensemble techniques, the free energy change along this reversible path can be obtained with an accuracy of 10(-3)k(B)T per molecule in the n VT-ensemble. Calculating the chemical potential, we obtain the free energy of a stalk in the grandcanonical ensemble, and employing semi-grandcanonical techniques, we calculate the change of the excess free energy upon altering the molecular architecture. This computational strategy can be applied to compute the free energy of self-assembled phases in lipid and copolymer systems, and the excess free energy of defects or interfaces.

Excess winter mortality and cold temperatures in a subtropical city, Guangzhou, China.

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Chun-Quan Ou

Full Text Available BACKGROUND: A significant increase in mortality was observed during cold winters in many temperate regions. However, there is a lack of evidence from tropical and subtropical regions, and the influence of ambient temperatures on seasonal variation of mortality was not well documented. METHODS: This study included 213,737 registered deaths from January 2003 to December 2011 in Guangzhou, a subtropical city in Southern China. Excess winter mortality was calculated by the excess percentage of monthly mortality in winters over that of non-winter months. A generalized linear model with a quasi-Poisson distribution was applied to analyze the association between monthly mean temperature and mortality, after controlling for other meteorological measures and air pollution. RESULTS: The mortality rate in the winter was 26% higher than the average rate in other seasons. On average, there were 1,848 excess winter deaths annually, with around half (52% from cardiovascular diseases and a quarter (24% from respiratory diseases. Excess winter mortality was higher in the elderly, females and those with low education level than the young, males and those with high education level, respectively. A much larger winter increase was observed in out-of-hospital mortality compared to in-hospital mortality (45% vs. 17%. We found a significant negative correlation of annual excess winter mortality with average winter temperature (rs=-0.738, P=0.037, but not with air pollution levels. A 1 °C decrease in monthly mean temperature was associated with an increase of 1.38% (95% CI:0.34%-2.40% and 0.88% (95% CI:0.11%-1.64% in monthly mortality at lags of 0-1 month, respectively. CONCLUSION: Similar to temperate regions, a subtropical city Guangzhou showed a clear seasonal pattern in mortality, with a sharper spike in winter. Our results highlight the role of cold temperature on the winter mortality even in warm climate. Precautionary measures should be strengthened to mitigate

Chiral Pharmaceutical Intermediaries Obtained by Reduction of 2-Halo-1-(4-substituted phenyl-ethanones Mediated by Geotrichum candidum CCT 1205 and Rhodotorula glutinis CCT 2182

Directory of Open Access Journals (Sweden)

Lucídio C. Fardelone

2011-01-01

Full Text Available Enantioselective reductions of p-R1-C6H4C(OCH2R2 (R1 = Cl, Br, CH3, OCH3, NO2 and R2 = Br, Cl mediated by Geotrichum candidum CCT 1205 and Rhodotorula glutinis CCT 2182 afforded the corresponding halohydrins with complementary R and S configurations, respectively, in excellent yield and enantiomeric excesses. The obtained (R- or (S-halohydrins are important building blocks in chemical and pharmaceutical industries.

Biphasic whole-cell synthesis of R-2-octanol with recycling of the ionic liquid

OpenAIRE

Dennewald, Danielle

2011-01-01

Whole-cell biocatalysis in biphasic systems permits the synthesis of inhibiting chiral alcohols if appropriate non-water miscible ionic liquids are used. Taking the asymmetric reduction of 2-octanone to R-2-octanol by a recombinant Escherichia coli as a model reaction, a detailed characterisation of the biocatalytic reaction was performed with [HMPL][NTF] as ionic liquid. This made the asymmetric synthesis of R-2-octanol in a simple batch at a conversion > 99 % and at an enantiomeric excess >...

Inhibiting excessive acidification using zero-valent iron in anaerobic digestion of food waste at high organic load rates.

Science.gov (United States)

Kong, Xin; Wei, Yonghong; Xu, Shuang; Liu, Jianguo; Li, Huan; Liu, Yili; Yu, Shuyao

2016-07-01

Excessive acidification occurs frequently in food waste (FW) anaerobic digestion (AD) due to the high carbon-to-nitrogen ratio of FW. In this study, zero-valent iron (ZVI) was applied to prevent the excessive acidification. All of the control groups, without ZVI addition (pH∼5.3), produced little methane (CH4) and had high volatile fatty acids/bicarbonate alkalinity (VFA/ALK). By contrast, at OLR of 42.32gVS/Lreactor, the pH of effluent from the reactors with 0.4g/gVSFWadded of ZVI increased to 7.8-8.2, VFA/ALK decreased to <0.1, and the final CH4 yield was ∼380mL/gVSFWadded, suggesting inhibition of excessive acidification. After adding powdered or scrap metal ZVI to the acidogenic reactors, the fractional content of butyric acid changed from 30-40% to 0%, while, that of acetic acid increased. These results indicate that adding ZVI to FW digestion at high OLRs could eliminate excessive acidification by promoting butyric acid conversion and enhancing methanogen activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Excessive crying in infants

Directory of Open Access Journals (Sweden)

Ricardo Halpern

2016-05-01

Full Text Available Objective: Review the literature on excessive crying in young infants, also known as infantile colic, and its effects on family dynamics, its pathophysiology, and new treatment interventions. Data source: The literature review was carried out in the Medline, PsycINFO, LILACS, SciELO, and Cochrane Library databases, using the terms “excessive crying,” and “infantile colic,” as well technical books and technical reports on child development, selecting the most relevant articles on the subject, with emphasis on recent literature published in the last five years. Summary of the findings: Excessive crying is a common symptom in the first 3 months of life and leads to approximately 20% of pediatric consultations. Different prevalence rates of excessive crying have been reported, ranging from 14% to approximately 30% in infants up to 3 months of age. There is evidence linking excessive crying early in life with adaptive problems in the preschool period, as well as with early weaning, maternal anxiety and depression, attention deficit hyperactivity disorder, and other behavioral problems. Several pathophysiological mechanisms can explain these symptoms, such as circadian rhythm alterations, central nervous system immaturity, and alterations in the intestinal microbiota. Several treatment alternatives have been described, including behavioral measures, manipulation techniques, use of medication, and acupuncture, with controversial results and effectiveness. Conclusion: Excessive crying in the early months is a prevalent symptom; the pediatrician's attention is necessary to understand and adequately manage the problem and offer support to exhausted parents. The prescription of drugs of questionable action and with potential side effects is not a recommended treatment, except in extreme situations. The effectiveness of dietary treatments and use of probiotics still require confirmation. There is incomplete evidence regarding alternative treatments

Rationalization of an unusual solvent-induced inversion of enantiomeric excess in organocatalytic selenylation of aldehydes.

Science.gov (United States)

Burés, Jordi; Dingwall, Paul; Armstrong, Alan; Blackmond, Donna G

2014-08-11

An unusual solvent-induced inversion of the sense of enantioselectivity observed in the α-selenylation of aldehydes catalyzed by a diphenylprolinol silyl ether catalyst is correlated to the presence of intermediates formed subsequent to the highly selective C-Se bond-forming step in the catalytic cycle. This work provides support for a mechanistic concept for enamine catalysis and includes a general role for "downstream intermediates" in selectivity outcomes in organocatalysis. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The excessively crying infant : etiology and treatment

NARCIS (Netherlands)

Akhnikh, S.; Engelberts, A.C.; Sleuwen, B.E. van; Hoir, M.P. L’; Benninga, M.A.

2014-01-01

Excessive crying, often described as infantile colic, is the cause of 10% to 20% of all early pediatrician visits of infants aged 2 weeks to 3 months. Although usually benign and selflimiting, excessive crying is associated with parental exhaustion and stress. However, and underlying organic cause

Enantiomeric separation and quantitative determination of propranolol enantiomers in pharmaceutical preparations by chiral liquid chromatography Separação e determinação quantitativa dos enantiômeros do propranolol em preparações farmacêuticas por cromatografia quiral

Directory of Open Access Journals (Sweden)

Anil K. Singh

2004-09-01

Full Text Available This paper describes validated direct liquid chromatographic chiral methods for enantiomeric separation and quantitative determination of clinically significant ²-blocking agent, propranolol. A liquid chromatographic method was validated and applied for enantiomeric determination of propranolol enantiomers in pharmaceutical formulations. Separation were obtained in polar organic mode on a ±-Burke 2® chiral stationary phase (250 x 4.6 mm, 5µm with mobile phase composed of dichloromethane:methanol (90:10 v/v, along with 12 mM of ammonium acetate, at a flow rate of 0.9 mL/min. Detection was made by ultraviolet absorption at 280 nm. In all cases the run time was less than 10 min. The correlation coefficient for linear regression curves of R-propranolol and S-propranolol were 0.9995 and 0.9998 respectively. The intra-day precision, expressed as RSD was less than 2%. The accuracy determined by average recovery of R-propranolol and S-propranolol from sample matrices were 97.3% and 100.1% in commercial sample and 99.5% and 100.4% in simulated samples, respectively. Excellent levels of limit of detection (mean value = 1.34 ng and limit of quantitation (mean value = 4.47 ng, along with rapid elution time of both enantiomers, makes the method useful for routine enantiomeric quality control applications.Neste trabalho é descrito um método validado empregando a cromatografia líquida de alta eficiência com fase estacionária quiral para a separação e determinação quantitativa dos enantiômeros do propranolol em formulações farmacêuticas. A separação foi obtida em meio orgânico polar empregando a coluna ±-Burke 2® como fase estacionária quiral (250 x 4,6 mm, 5 µm e fase móvel constituída por diclorometano: metanol (90:10 v/v juntamente com 12 mM de acetato de amônio e vazão de 0,9 mL/min. A detecção foi efetuada por absorção no ultravioleta a 280 nm. Em todos casos o tempo de corrida foi menor do que 10 min. O coeficiente de

Optimization of excess Bi doping to enhance ferroic orders of spin casted BiFeO3 thin film

International Nuclear Information System (INIS)

Gupta, Surbhi; Gupta, Vinay; Tomar, Monika; James, A. R.; Pal, Madhuparna; Guo, Ruyan; Bhalla, Amar

2014-01-01

Multiferroic Bismuth Ferrite (BiFeO 3 ) thin films with varying excess bismuth (Bi) concentration were grown by chemical solution deposition technique. Room temperature multiferroic properties (ferromagnetism, ferroelectricity, and piezoelectricity) of the deposited BiFeO 3 thin films have been studied. High resolution X-ray diffraction and Raman spectroscopy studies reveal that the dominant phases formed in the prepared samples change continuously from a mixture of BiFeO 3 and Fe 2 O 3 to pure BiFeO 3 phase and, subsequently, to a mixture of BiFeO 3 and Bi 2 O 3 with increase in the concentration of excess Bi from 0% to 15%. BiFeO 3 thin films having low content (0% and 2%) of excess Bi showed the traces of ferromagnetic phase (γ-Fe 2 O 3 ). Deterioration in ferroic properties of BiFeO 3 thin films is also observed when prepared with higher content (15%) of excess Bi. Single-phased BiFeO 3 thin film prepared with 5% excess Bi concentration exhibited the soft ferromagnetic hysteresis loops and ferroelectric characteristics with remnant polarization 4.2 μC/cm 2 and saturation magnetization 11.66 emu/g. The switching of fine spontaneous domains with applied dc bias has been observed using piezoresponse force microscopy in BiFeO 3 thin films having 5% excess Bi. The results are important to identify optimum excess Bi concentration needed for the formation of single phase BiFeO 3 thin films exhibiting the improved multiferroic properties.

Excessive Gambling and Online Gambling Communities.

Science.gov (United States)

Sirola, Anu; Kaakinen, Markus; Oksanen, Atte

2018-04-05

The Internet provides an accessible context for online gambling and gambling-related online communities, such as discussion forums for gamblers. These communities may be particularly attractive to young gamblers who are active Internet users. The aim of this study was to examine the use of gambling-related online communities and their relevance to excessive gambling among 15-25-year-old Finnish Internet users (N = 1200). Excessive gambling was assessed by using the South Oaks Gambling Screen. Respondents were asked in a survey about their use of various kinds of gambling-related online communities, and sociodemographic and behavioral factors were adjusted. The results of the study revealed that over half (54.33%) of respondents who had visited gambling-related online communities were either at-risk gamblers or probable pathological gamblers. Discussion in these communities was mainly based on sharing gambling tips and experiences, and very few respondents said that they related to gambling problems and recovery. In three different regression models, visiting gambling-related online communities was a significant predictor for excessive gambling (with 95% confidence level) even after adjusting confounding factors. The association of visiting such sites was even stronger among probable pathological gamblers than among at-risk gamblers. Health professionals working with young people should be aware of the role of online communities in terms of development and persistence of excessive gambling. Monitoring the use of online gambling communities as well as utilizing recovery-oriented support both offline and online would be important in preventing further problems. Gambling platforms should also include warnings about excessive gambling and provide links to helpful sources.

Spatial distributions and enantiomeric signatures of DDT and its metabolites in tree bark from agricultural regions across China.

Science.gov (United States)

Niu, Lili; Xu, Chao; Zhang, Chunlong; Zhou, Yuting; Zhu, Siyu; Liu, Weiping

2017-10-01

Tree bark is considered as an effective passive sampler for estimating the atmospheric status of pollutants. In this study, we conducted a national scale tree bark sampling campaign across China. Concentration profiles revealed that Eastern China, especially the Jing-Jin-Ji region (including Hebei Province, Beijing and Tianjin) was a hot spot of bark DDT pollution. The enantioselective accumulation of o,p'-DDT was observed in most of the samples and 68% of them showed a preferential depletion of (+)-o,p'-DDT. These results suggest that DDTs in rural bark are likely from combined sources including historical technical DDTs and fresh dicofol usage. The tree bulk DDT levels were found to correlate with soil DDT concentrations, socioeconomy and PM 2.5 of the sampling sites. It thus becomes evident that the reemission from soils and subsequent atmospheric deposition were the major pathways leading to the accumulation of DDTs in bark. Based on a previously established bark-air partitioning model, the concentrations of DDTs in the air were estimated from measured concentrations in tree bark, and the results were comparable to those obtained by the use of passive sampling with polyurethane foam (PUF) disks. Our results demonstrate the feasibility of delineating the spatial variations in atmospheric concentration and tracing sources of DDTs by integrating the use of tree bark with enantiomeric analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Di-photon excess at LHC and the gamma ray excess at the Galactic Centre

Energy Technology Data Exchange (ETDEWEB)

Hektor, Andi [National Institute of Chemical Physics and Biophysics,Rävala pst. 10, 10143 Tallinn (Estonia); Marzola, Luca [National Institute of Chemical Physics and Biophysics,Rävala pst. 10, 10143 Tallinn (Estonia); Institute of Physics, University of Tartu,Ravila 14c, 50411 Tartu (Estonia)

2016-07-25

Motivated by the recent indications for a 750 GeV resonance in the di-photon final state at the LHC, in this work we analyse the compatibility of the excess with the broad photon excess detected at the Galactic Centre. Intriguingly, by analysing the parameter space of an effective models where a 750 GeV pseudoscalar particles mediates the interaction between the Standard Model and a scalar dark sector, we prove the compatibility of the two signals. We show, however, that the LHC mono-jet searches and the Fermi LAT measurements strongly limit the viable parameter space. We comment on the possible impact of cosmic antiproton flux measurement by the AMS-02 experiment.

Excessive crying in infants with regulatory disorders.

Science.gov (United States)

Maldonado-Duran, M; Sauceda-Garcia, J M

1996-01-01

The authors point out a correlation between regulatory disorders in infants and the problem of excessive crying. The literature describes other behavioral problems involving excessive crying in very young children, but with little emphasis on this association. The recognition and diagnosis of regulatory disorders in infants who cry excessively can help practitioners design appropriate treatment interventions. Understanding these conditions can also help parents tailor their caretaking style, so that they provide appropriate soothing and stimulation to their child. In so doing, they will be better able to develop and preserve a satisfactory parent-child relationship, as well as to maintain their own sense of competence and self-esteem as parents.

Part B Excess Cost Quick Reference Document

Science.gov (United States)

Ball, Wayne; Beridon, Virginia; Hamre, Kent; Morse, Amanda

2011-01-01

This Quick Reference Document has been prepared by the Regional Resource Center Program ARRA/Fiscal Priority Team to aid RRCP State Liaisons and other (Technical Assistance) TA providers in understanding the general context of state questions surrounding excess cost. As a "first-stop" for TA providers in investigating excess cost…

Twentieth century surge of excess adult male mortality

Science.gov (United States)

Beltrán-Sánchez, Hiram; Finch, Caleb E.; Crimmins, Eileen M.

2015-01-01

Using historical data from 1,763 birth cohorts from 1800 to 1935 in 13 developed countries, we show that what is now seen as normal—a large excess of female life expectancy in adulthood—is a demographic phenomenon that emerged among people born in the late 1800s. We show that excess adult male mortality is clearly rooted in specific age groups, 50–70, and that the sex asymmetry emerged in cohorts born after 1880 when male:female mortality ratios increased by as much as 50% from a baseline of about 1.1. Heart disease is the main condition associated with increased excess male mortality for those born after 1900. We further show that smoking-attributable deaths account for about 30% of excess male mortality at ages 50–70 for cohorts born in 1900–1935. However, after accounting for smoking, substantial excess male mortality at ages 50–70 remained, particularly from cardiovascular disease. The greater male vulnerability to cardiovascular conditions emerged with the reduction in infectious mortality and changes in health-related behaviors. PMID:26150507

Excessive exposures of diagnostic X-ray workers in India

International Nuclear Information System (INIS)

Ambiger, T.Y.; Shenoy, K.S.; Patel, P.H.

1980-01-01

The excessive exposures (i.e. exceeding 400 mrems per fortnight) of diagnostic X-ray workers revealed under the countrywide personnel monitoring programme in India have been analysed. The analysis covers the data collected over a period of ten years during 1965-1974. The radiation workers in medical X-ray diagnostic group receiving an excess dose are found to be less than 1%. Each case of the excess dose is throughly investigated and nongenuine cases are separated and causes for genuine excessive exposures are traced. The causes and the corrective measures are enumerated. (M.G.B.)

Excessive internet use in European adolescents: what determines differences in severity?

Science.gov (United States)

Blinka, Lukas; Škařupová, Kateřina; Ševčíková, Anna; Wölfling, Klaus; Müller, Kai W; Dreier, Michael

2015-02-01

This study investigated the differences between non-excessive, moderately excessive, and highly excessive internet use among adolescents. These differences were explored in terms of personal characteristics, psychological difficulties, environmental factors, and manner of internet use. A representative sample was investigated, consisting of 18,709 adolescents aged 11-16 and their parents, from 25 European countries. Excessive internet use was measured using a five item scale covering following factors: salience, conflict, tolerance, withdrawal symptoms, and relapse and reinstatement. The main data analysis utilised multinomial and binary logistic regression models. The vast majority of respondents reported no signs of excessive internet use. Moderately excessive users (4.4%) reported higher emotional and behavioural difficulties, but also more sophisticated digital skills and a broader range of online activities. The highly excessive users (1.4%) differed from the non-excessive and moderately excessive users in their preference for online games and in having more difficulties with self-control. Adolescents who struggle with attention and self-control and who are inclined toward online gaming may be especially vulnerable to the otherwise uncommon phenomenon of excessive internet use.

Calculating excess lifetime risk in relative risk models

International Nuclear Information System (INIS)

Vaeth, M.; Pierce, D.A.

1990-01-01

When assessing the impact of radiation exposure it is common practice to present the final conclusions in terms of excess lifetime cancer risk in a population exposed to a given dose. The present investigation is mainly a methodological study focusing on some of the major issues and uncertainties involved in calculating such excess lifetime risks and related risk projection methods. The age-constant relative risk model used in the recent analyses of the cancer mortality that was observed in the follow-up of the cohort of A-bomb survivors in Hiroshima and Nagasaki is used to describe the effect of the exposure on the cancer mortality. In this type of model the excess relative risk is constant in age-at-risk, but depends on the age-at-exposure. Calculation of excess lifetime risks usually requires rather complicated life-table computations. In this paper we propose a simple approximation to the excess lifetime risk; the validity of the approximation for low levels of exposure is justified empirically as well as theoretically. This approximation provides important guidance in understanding the influence of the various factors involved in risk projections. Among the further topics considered are the influence of a latent period, the additional problems involved in calculations of site-specific excess lifetime cancer risks, the consequences of a leveling off or a plateau in the excess relative risk, and the uncertainties involved in transferring results from one population to another. The main part of this study relates to the situation with a single, instantaneous exposure, but a brief discussion is also given of the problem with a continuous exposure at a low-dose rate

Activation parameters and excess thermodyanamic functions of hydroxamic acids in acetone-water mixture at 303.15 K and 313.15 K: A viscometric approach

Directory of Open Access Journals (Sweden)

Ajita Dixit

2007-04-01

Full Text Available Experimental values of density and viscosity of N-arylsubstituted hydroxamic acids were evaluated at T = 303.15 K and 313.15 K in acetone-water mixture as a function of their concentration. The properties of solutes were obtained as an intercept of plots C vs η of solutions. Applying these data, viscosity-B-coefficients, activation parameters (Δμ10≠ and (Δμ20≠ and excess thermodynamic functions, viz., excess molar volume (VE, excess viscosity, ηE and excess molar free energy of activation of flow, (GE were calculated. The value of interaction parameter, d, of Grunberg and Nissan expression have also been calculated and reported. Analysis of these data suggests that specific interactions are present in the system.

Kinetic resolution and stereoselective synthesis of 3-substituted aspartic acids by using engineered methylaspartate ammonia lyases.

Science.gov (United States)

Raj, Hans; Szymanski, Wiktor; de Villiers, Jandré; Puthan Veetil, Vinod; Quax, Wim J; Shimamoto, Keiko; Janssen, Dick B; Feringa, Ben L; Poelarends, Gerrit J

2013-08-19

Enzymatic amino acid synthesis: Kinetic resolution and asymmetric synthesis of various valuable 3-substituted aspartic acids, which were obtained in fair to good yields with diastereomeric ratio values of up to >98:2 and enantiomeric excess values of up to >99 %, by using engineered methylaspartate ammonia lyases are described. These biocatalytic methodologies for the selective preparation of aspartic acid derivatives appear to be attractive alternatives for existing chemical methods. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Regiospecific and stereoselective hydroxylation of 1-indanone and 2-indanone by naphthalene dioxygenase and toluene dioxygenase.

OpenAIRE

Resnick, S M; Torok, D S; Lee, K; Brand, J M; Gibson, D T

1994-01-01

The biotransformation of 1-indanone and 2-indanone to hydroxyindanones was examined with bacterial strains expressing naphthalene dioxygenase (NDO) and toluene dioxygenase (TDO) as well as with purified enzyme components. Pseudomonas sp. strain 9816/11 cells, expressing NDO, oxidized 1-indanone to a mixture of 3-hydroxy-1-indanone (91%) and 2-hydroxy-1-indanone (9%). The (R)-3-hydroxy-1-indanone was formed in 62% enantiomeric excess (ee) (R:S, 81:19), while the 2-hydroxy-1-indanone was racemi...

HIV Excess Cancers JNCI

Science.gov (United States)

In 2010, an estimated 7,760 new cancers were diagnosed among the nearly 900,000 Americans known to be living with HIV infection. According to the first comprehensive study in the United States, approximately half of these cancers were in excess of what wo

The Hurt of Judgment in Excessive Weight Women: A Hermeneutic Study.

Science.gov (United States)

Mehrdad, Neda; Hossein Abbasi, Nahid; Nikbakht Nasrabadi, Alireza

2015-04-23

Excess weight is one of the increasing problems of the present society and one of the threatening health conditions around the world. Despite many efforts for prevention and treatment or even surgery, the process of excess weight is not decreased in the world. While most of the studies conducted on excess weight concentrated on the issues why people get excess weight or how the prevention and treatment of excess weight must be performed, there is lake of knowledge about what excessive weight people really experience in their daily life. Understanding the lived experience of excess weight in women is linked with their health and society's health while it indirectly develops the nursing knowledge to improve the quality and access to holistic health care in excessive weight women. The aim of study was to describe with a deeper understanding, the lived experience of excess weight in women. Using a hermeneutic phenomenological approach and a van-manen analysis methods, in depth semi- structured interviews were conducted with twelve women who had lived experience of excess weight. The hurt of Judgment was the main theme that emerged in the process of data analysis. This theme was derived from three sub-themes including social judgment, being different and being seen. These findings can prove helpful in promoting the nursing knowledge concerning a holistic approach in communicating to excessive weight people.

Limiting law excess sum rule for polyelectrolytes.

Science.gov (United States)

Landy, Jonathan; Lee, YongJin; Jho, YongSeok

2013-11-01

We revisit the mean-field limiting law screening excess sum rule that holds for rodlike polyelectrolytes. We present an efficient derivation of this law that clarifies its region of applicability: The law holds in the limit of small polymer radius, measured relative to the Debye screening length. From the limiting law, we determine the individual ion excess values for single-salt electrolytes. We also consider the mean-field excess sum away from the limiting region, and we relate this quantity to the osmotic pressure of a dilute polyelectrolyte solution. Finally, we consider numerical simulations of many-body polymer-electrolyte solutions. We conclude that the limiting law often accurately describes the screening of physical charged polymers of interest, such as extended DNA.

Does Bertrand's rule apply to macronutrients?

OpenAIRE

Raubenheimer, D; Lee, K.P; Simpson, S.J

2005-01-01

It has been known for over a century that the dose–response curve for many micronutrients is non-monotonic, having an initial stage of increasing benefits with increased intake, followed by increasing costs as excesses become toxic. This phenomenon, termed Bertrand's rule, is widely assumed not to apply to caloric macronutrients. To date this assumption has been safe, owing to the considerable methodological challenges involved in coaxing animals to over-ingest macronutrients in a way that en...

Rough Electrode Creates Excess Capacitance in Thin-Film Capacitors.

Science.gov (United States)

Torabi, Solmaz; Cherry, Megan; Duijnstee, Elisabeth A; Le Corre, Vincent M; Qiu, Li; Hummelen, Jan C; Palasantzas, George; Koster, L Jan Anton

2017-08-16

The parallel-plate capacitor equation is widely used in contemporary material research for nanoscale applications and nanoelectronics. To apply this equation, flat and smooth electrodes are assumed for a capacitor. This essential assumption is often violated for thin-film capacitors because the formation of nanoscale roughness at the electrode interface is very probable for thin films grown via common deposition methods. In this work, we experimentally and theoretically show that the electrical capacitance of thin-film capacitors with realistic interface roughness is significantly larger than the value predicted by the parallel-plate capacitor equation. The degree of the deviation depends on the strength of the roughness, which is described by three roughness parameters for a self-affine fractal surface. By applying an extended parallel-plate capacitor equation that includes the roughness parameters of the electrode, we are able to calculate the excess capacitance of the electrode with weak roughness. Moreover, we introduce the roughness parameter limits for which the simple parallel-plate capacitor equation is sufficiently accurate for capacitors with one rough electrode. Our results imply that the interface roughness beyond the proposed limits cannot be dismissed unless the independence of the capacitance from the interface roughness is experimentally demonstrated. The practical protocols suggested in our work for the reliable use of the parallel-plate capacitor equation can be applied as general guidelines in various fields of interest.

41 CFR 302-7.201 - Is temporary storage in excess of authorized limits and excess valuation of goods and services...

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false Is temporary storage in excess of authorized limits and excess valuation of goods and services payable at Government expense? 302-7.201 Section 302-7.201 Public Contracts and Property Management Federal Travel Regulation System...

Enantiomeric high-performance liquid chromatography resolution and absolute configuration of 6β-benzoyloxy-3α-tropanol.

Science.gov (United States)

Muñoz, Marcelo A; González, Natalia; Joseph-Nathan, Pedro

2016-07-01

The absolute configuration of the naturally occurring isomers of 6β-benzoyloxy-3α-tropanol (1) has been established by the combined use of chiral high-performance liquid chromatography with electronic circular dichroism detection and optical rotation detection. For this purpose (±)-1, prepared in two steps from racemic 6-hydroxytropinone (4), was subjected to chiral high-performance liquid chromatography with electronic circular dichroism and optical rotation detection allowing the online measurement of both chiroptical properties for each enantiomer, which in turn were compared with the corresponding values obtained from density functional theory calculations. In an independent approach, preparative high-performance liquid chromatography separation using an automatic fraction collector, yielded an enantiopure sample of OR (+)-1 whose vibrational circular dichroism spectrum allowed its absolute configuration assignment when the bands in the 1100-950 cm(-1) region were compared with those of the enantiomers of esters derived from 3α,6β-tropanediol. In addition, an enantiomerically enriched sample of 4, instead of OR (±)-4, was used for the same transformation sequence, whose high-performance liquid chromatography follow-up allowed their spectroscopic correlation. All evidences lead to the OR (+)-(1S,3R,5S,6R) and OR (-)-(1R,3S,5R,6S) absolute configurations, from where it follows that samples of 1 isolated from Knightia strobilina and Erythroxylum zambesiacum have the OR (+)-(1S,3R,5S,6R) absolute configuration, while the sample obtained from E. rotundifolium has the OR (-)-(1R,3S,5R,6S) absolute configuration. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Criminal Liability of Managers for Excessive Risk-Taking?

NARCIS (Netherlands)

Tosza, S.T.

2016-01-01

The aim of the thesis was to analyse and evaluate the criminalisation of excessively risky decisions taken by managers of limited liability companies. The potentially disastrous consequences of excessive risk-taking were powerfully highlighted by the most recent financial crunch, although its

Timing of Excessive Weight Gain During Pregnancy Modulates Newborn Anthropometry.

Science.gov (United States)

Ruchat, Stephanie-May; Allard, Catherine; Doyon, Myriam; Lacroix, Marilyn; Guillemette, Laetitia; Patenaude, Julie; Battista, Marie-Claude; Ardilouze, Jean-Luc; Perron, Patrice; Bouchard, Luigi; Hivert, Marie-France

2016-02-01

Excessive gestational weight gain (GWG) is associated with increased birth weight and neonatal adiposity. However, timing of excessive GWG may have a differential impact on birth outcomes. The objective of this study was to compare the effect of early and mid/late excessive GWG on newborn anthropometry in the context of the Canadian clinical recommendations that are specific for first trimester and for second/third trimesters based on maternal pre-pregnancy BMI. We included 607 glucose-tolerant women in our main analyses, after excluding women who had less than the recommended total GWG. Maternal body weight was measured in early pregnancy, mid-pregnancy, and late pregnancy. Maternal and fetal clinical outcomes were collected, including newborn anthropometry. Women were divided into four groups according to the Canadian guidelines for GWG in the first and in the second/third trimesters: (1) "overall non-excessive" (reference group); (2) "early excessive GWG"; (3) "mid/late excessive GWG"; and (4) "overall excessive GWG." Differences in newborn anthropometry were tested across GWG categories. Women had a mean (±SD) pre-pregnancy BMI of 24.7 ± 5.2 kg/m(2) and total GWG of 15.3 ± 4.4 kg. Women with mid/late excessive GWG gave birth to heavier babies (gestational age-adjusted birth weight z-score 0.33 ± 0.91) compared with women in the reference group (0.00 ± 0.77, P = 0.007), whereas women with early excessive GWG gave birth to babies of similar weight (gestational age-adjusted z-score 0.01 ± 0.86) to the reference group (0.00 ± 0.77, P = 0.84). When we stratified our analyses and investigated women who gained within the recommendations for total GWG, mid/late excessive GWG specifically was associated with greater newborn size, similar to our main analyses. Excessive GWG in mid/late pregnancy in women who did not gain weight excessively in early pregnancy is associated with increased birth size, even in those who gained within the Canadian recommendations

Industrial excess heat for district heating in Denmark

DEFF Research Database (Denmark)

Bühler, Fabian; Petrovic, Stefan; Karlsson, Kenneth Bernard

2017-01-01

analyses excess heat sources from the industrial sector and how they could be used for district heating. This method first allocates excess heat to single production units by introducing and validating a new approach. Spatial analysis of the heat sources and consumers are then performed to evaluate...... the potential for using them for district heating. In this way the theoretical potential of using the excess heat for covering the heating demand of buildings is determined. Through the use of industry specific temperature profiles the heat usable directly or via heat pumps is further found. A sensitivity...... analysis investigates the impact of future energy efficiency measures in the industry, buildings and the district heating grid on the national potential. The results show that for the case study of Denmark, 1.36 TWh of district heat could be provided annually with industrial excess heat from thermal...

Excessive anticoagulation with warfarin or phenprocoumon may have multiple causes

DEFF Research Database (Denmark)

Meegaard, Peter Martin; Holck, Line H V; Pottegård, Anton

2012-01-01

Excessive anticoagulation with vitamin K antagonists is a serious condition with a substantial risk of an adverse outcome. We thus found it of interest to review a large case series to characterize the underlying causes of excessive anticoagulation.......Excessive anticoagulation with vitamin K antagonists is a serious condition with a substantial risk of an adverse outcome. We thus found it of interest to review a large case series to characterize the underlying causes of excessive anticoagulation....

40 CFR 76.13 - Compliance and excess emissions.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Compliance and excess emissions. 76.13 Section 76.13 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.13 Compliance and excess emissions...

Fertilizing nature: a tragedy of excess in the commons.

Directory of Open Access Journals (Sweden)

Allen G Good

2011-08-01

Full Text Available Globally, we are applying excessive nitrogen (N fertilizers to our agricultural crops, which ultimately causes nitrogen pollution to our ecosphere. The atmosphere is polluted by N₂O and NO(x gases that directly and indirectly increase atmospheric warming and climate change. Nitrogen is also leached from agricultural lands as the water-soluble form NO₃⁻, which increases nutrient overload in rivers, lakes, and oceans, causing "dead zones", reducing property values and the diversity of aquatic life, and damaging our drinking water and aquatic-associated industries such as fishing and tourism. Why do some countries show reductions in fertilizer use while others show increasing use? What N fertilizer application reductions could occur, without compromising crop yields? And what are the economic and environmental benefits of using directed nutrient management strategies?

Positionally isomeric organic gelators: structure-gelation study, racemic versus enantiomeric gelators, and solvation effects.

Science.gov (United States)

Caplar, Vesna; Frkanec, Leo; Sijaković Vujicić, Natasa; Zinić, Mladen

2010-03-08

Low molecular weight gelator molecules consisting of aliphatic acid, amino acid (phenylglycine), and omega-aminoaliphatic acid units have been designed. By varying the number of methylene units in the aliphatic and omega-aminoaliphatic acid chains, as defined by descriptors m and n, respectively, a series of positionally isomeric gelators having different positions of the peptidic hydrogen-bonding unit within the gelator molecule has been obtained. The gelation properties of the positional isomers have been determined in relation to a defined set of twenty solvents of different structure and polarity and analyzed in terms of gelator versatility (G(ver)) and effectiveness (G(eff)). The results of gelation tests have shown that simple synthetic optimizations of a "lead gelator molecule" by variation of m and n, end-group polarity (carboxylic acid versus sodium carboxylate), and stereochemistry (racemate versus optically pure form) allowed the identification of gelators with tremendously improved versatility (G(ver)) and effectiveness (G(eff)). Dramatic differences in G(eff) values of up to 70 times could be observed between pure racemate/enantiomer pairs of some gelators, which were manifested even in the gelation of very similar solvents such as isomeric xylenes. The combined results of spectroscopic ((1)H NMR, FTIR), electron microscopy (TEM), and X-ray diffraction studies suggest similar organization of the positionally isomeric gelators at the molecular level, comprising parallel beta-sheet hydrogen-bonded primary assemblies that form inversed bilayers at a higher organizational level. Differential scanning calorimetry (DSC) studies of selected enantiomer/racemate gelator pairs and their o- and p-xylene gels revealed the simultaneous presence of different polymorphs in the racemate gels. The increased gelation effectiveness of the racemate compared to that of the single enantiomer is most likely a consequence of its spontaneous resolution into enantiomeric

Experimental and predicted data of excess molar enthalpies and excess molar volumes for the ternary system (1,3-dichlorobenzene + benzene + 1-chlorohexane) at T = 298.15 K

International Nuclear Information System (INIS)

Mato, Marta M.; Verdes, Pedro V.; Paz Andrade, M.I.; Legido, José Luis

2014-01-01

Graphical abstract: - Highlights: • Experimental enthalpy and densitiy for the mixture 1,3-dichlorobenzene + benzene + 1-chlorohexane were measured. • The excess molar volumes were calculated from the densities of the pure liquids and their mixtures. • The Cibulka equation was used to correlate the ternary contribution of the excess molar properties. • The experimental data were used to test several empirical equations. - Abstract: Experimental excess molar enthalpies, densities and excess molar volumes for the ternary system {x 1 1,3-dichlorobenzene + x 2 benzene + (1 − x 1 − x 2 ) 1-chlorohexane} have been determined at the temperature of 298.15 K and atmospheric pressure. Values of excess molar enthalpies were measured using a Calvet microcalorimeter, and excess molar volumes were determined from the densities of the pure liquids and mixtures, using a vibrating-tube densimeter. The results were fitted by means of different variable degree polynomials. Smooth representations of the results are presented and used to construct constant contours of excess molar enthalpy and excess molar volume on Roozeboom diagrams. Several empirical expressions that have been suggested for use with parameters and predicting excess properties of ternary mixtures from the experimental binary data were tested

Earnings Quality Measures and Excess Returns.

Science.gov (United States)

Perotti, Pietro; Wagenhofer, Alfred

2014-06-01

This paper examines how commonly used earnings quality measures fulfill a key objective of financial reporting, i.e., improving decision usefulness for investors. We propose a stock-price-based measure for assessing the quality of earnings quality measures. We predict that firms with higher earnings quality will be less mispriced than other firms. Mispricing is measured by the difference of the mean absolute excess returns of portfolios formed on high and low values of a measure. We examine persistence, predictability, two measures of smoothness, abnormal accruals, accruals quality, earnings response coefficient and value relevance. For a large sample of US non-financial firms over the period 1988-2007, we show that all measures except for smoothness are negatively associated with absolute excess returns, suggesting that smoothness is generally a favorable attribute of earnings. Accruals measures generate the largest spread in absolute excess returns, followed by smoothness and market-based measures. These results lend support to the widespread use of accruals measures as overall measures of earnings quality in the literature.

Optimization of excess Bi doping to enhance ferroic orders of spin casted BiFeO{sub 3} thin film

Energy Technology Data Exchange (ETDEWEB)

Gupta, Surbhi; Gupta, Vinay, E-mail: drguptavinay@gmail.com [Department of Physics and Astrophysics, University of Delhi, Delhi (India); Tomar, Monika [Department of Physics, Miranda Housea, University of Delhi, Delhi (India); James, A. R. [Defence Metallurgical Research Laboratory, Hyderabad (India); Pal, Madhuparna; Guo, Ruyan; Bhalla, Amar [Department of Electrical and Computer Engineering, College of Engineering, University of Texas at SanAntonio, San Antonio 78249 (United States)

2014-06-21

Multiferroic Bismuth Ferrite (BiFeO{sub 3}) thin films with varying excess bismuth (Bi) concentration were grown by chemical solution deposition technique. Room temperature multiferroic properties (ferromagnetism, ferroelectricity, and piezoelectricity) of the deposited BiFeO{sub 3} thin films have been studied. High resolution X-ray diffraction and Raman spectroscopy studies reveal that the dominant phases formed in the prepared samples change continuously from a mixture of BiFeO{sub 3} and Fe{sub 2}O{sub 3} to pure BiFeO{sub 3} phase and, subsequently, to a mixture of BiFeO{sub 3} and Bi{sub 2}O{sub 3} with increase in the concentration of excess Bi from 0% to 15%. BiFeO{sub 3} thin films having low content (0% and 2%) of excess Bi showed the traces of ferromagnetic phase (γ-Fe{sub 2}O{sub 3}). Deterioration in ferroic properties of BiFeO{sub 3} thin films is also observed when prepared with higher content (15%) of excess Bi. Single-phased BiFeO{sub 3} thin film prepared with 5% excess Bi concentration exhibited the soft ferromagnetic hysteresis loops and ferroelectric characteristics with remnant polarization 4.2 μC/cm{sup 2} and saturation magnetization 11.66 emu/g. The switching of fine spontaneous domains with applied dc bias has been observed using piezoresponse force microscopy in BiFeO{sub 3} thin films having 5% excess Bi. The results are important to identify optimum excess Bi concentration needed for the formation of single phase BiFeO{sub 3} thin films exhibiting the improved multiferroic properties.

The High Price of Excessive Alcohol Consumption

Centers for Disease Control (CDC) Podcasts

This podcast is based on the October 2011 release of a report estimating the economic cost of excessive drinking. Excessive alcohol consumption cost the U. S. $223.5 billion in 2006, or about $1.90 per drink. Over three-quarters (76%) of these costs were due to binge drinking, defined as consuming 4 or more alcoholic beverages per occasion for women or 5 or more drinks per occasion for men.

Brazilian air traffic controllers exhibit excessive sleepiness.

Science.gov (United States)

Ribas, Valdenilson Ribeiro; de Almeida, Cláudia Ângela Vilela; Martins, Hugo André de Lima; Alves, Carlos Frederico de Oliveira; Alves, Marcos José Pinheiro Cândido; Carneiro, Severino Marcos de Oliveira; Ribas, Valéria Ribeiro; de Vasconcelos, Carlos Augusto Carvalho; Sougey, Everton Botelho; de Castro, Raul Manhães

2011-01-01

Excessive sleepiness (ES) is an increased tendency to initiate involuntary sleep for naps at inappropriate times. The objective of this study was to assess ES in air traffic controllers (ATCo). 45 flight protection professionals were evaluated, comprising 30 ATCo, subdivided into ATCo with ten or more years in the profession (ATCo≥10, n=15) and ATCo with less than ten years in the profession (ATCoair traffic controllers exhibit excessive sleepiness.

Excess molar volumes and isentropic compressibilities of binary

Indian Academy of Sciences (India)

Excess molar volumes (E) and deviation in isentropic compressibilities (s) have been investigated from the density and speed of sound measurements of six binary liquid mixtures containing -alkanes over the entire range of composition at 298.15 K. Excess molar volume exhibits inversion in sign in one binary ...

Disposition of excess material

International Nuclear Information System (INIS)

Hall, J.C.

1978-01-01

This paper reviews briefly the means available to an enrichment customer to dispose of excess material scheduled for delivery under a fixed-commitment contract, other than through termination of the related separative work. The methods are as follows: (1) sales; (2) use in facilities covered by other DOE contracts; and (3) assignment

A reductive aminase from Aspergillus oryzae

OpenAIRE

Grogan, Gideon James; Aleku, Godwin; France, Scott; Man, Henry Wing-Hong; Mangas-Sanchez, Juan; Sharma, Mahima; Montgomery, Sarah L; Leipold, Friedemann; Hussain, Shahed; Turner, Nicholas

2017-01-01

Reductive amination is one of the most important methods for the synthesis of chiral amines. Here we report the discovery of an NADP(H)-dependent reductive aminase from Aspergillus oryzae (AspRedAm, Uniprot code Q2TW47) which can catalyse the reductive coupling of a broad set of carbonyl compounds with a variety of primary and secondary amines with up to >98% conversion and with up to >98% enantiomeric excess. In cases where both carbonyl and amine show high reactivity, it is possible to empl...

Explaining excess morbidity amongst homeless shelter users

DEFF Research Database (Denmark)

Benjaminsen, Lars; Birkelund, Jesper Fels

2018-01-01

AIMS: This article analyses excess morbidity amongst homeless shelter users compared to the general Danish population. The study provides an extensive control for confounding and investigates to what extent excess morbidity is explained by homelessness or other risk factors. METHODS: Data set...... includes administrative micro-data for 4,068,926 Danes who were 23 years or older on 1 January 2007. Nationwide data on shelter use identified 14,730 individuals as shelter users from 2002 to 2006. Somatic diseases were measured from 2007 to 2011 through diagnosis data from hospital discharges. The risk...... of somatic diseases amongst shelter users was analysed through a multivariate model that decomposed the total effect into a direct effect and indirect effects mediated by other risk factors. RESULTS: The excess morbidity associated with shelter use is substantially lower than in studies that did not include...

Prevalence of excessive screen time and associated factors in adolescents

Directory of Open Access Journals (Sweden)

Joana Marcela Sales de Lucena

2015-12-01

Full Text Available Objective: To determine the prevalence of excessive screen time and to analyze associated factors among adolescents. Methods: This was a cross-sectional school-based epidemiological study with 2874 high school adolescents with age 14-19 years (57.8% female from public and private schools in the city of João Pessoa, PB, Northeast Brazil. Excessive screen time was defined as watching television and playing video games or using the computer for more than 2 h/day. The associated factors analyzed were: sociodemographic (gender, age, economic class, and skin color, physical activity and nutritional status of adolescents. Results: The prevalence of excessive screen time was 79.5% (95%CI 78.1-81.1 and it was higher in males (84.3% compared to females (76.1%; p<0.001. In multivariate analysis, adolescent males, those aged 14-15 year old and the highest economic class had higher chances of exposure to excessive screen time. The level of physical activity and nutritional status of adolescents were not associated with excessive screen time. Conclusions: The prevalence of excessive screen time was high and varied according to sociodemographic characteristics of adolescents. It is necessary to develop interventions to reduce the excessive screen time among adolescents, particularly in subgroups with higher exposure.

Annealing behaviour of excess carriers in neutron-transmutation-doped silicon

International Nuclear Information System (INIS)

Maekawa, T.; Nogami, S.; Inoue, S.

1993-01-01

In neutron-transmutation-doped silicon wafers excess carriers are clearly generated over the transmuted phosphorus atoms. The generation occurs for annealing temperatures above 900 o C. The maximum percentage of excess carriers obtained is about 24.5% of the final carrier concentration. Due to the difference in energy of generation and removal, the excess carriers can be removed by annealing above 800 o C. The radiation damage responsible for generation of excess carriers is fairly thermostable in the range of annealing temperatures below 800 o C. From deep-level transient spectroscopy measurements, it is found that the radiation damage remains insensitive to changes in carrier concentration. The activation energies of excess carrier generation and removal are estimated from the analysis of the thermal and temporal behaviours of radiation damage in the annealing process. (Author)

Simultaneous influence of Stark effect and excessive line broadening on the Hα line

Science.gov (United States)

Cvetanović, Nikola; Ivković, Saša S.; Obradović, Bratislav M.; Kuraica, Milorad M.

2017-12-01

The aim of this paper is to study the combined influence of the Stark effect and the excessive Doppler broadening on the Balmer alpha line in hydrogen discharges. Since this line is a good candidate for measuring electric field in various types of discharges with different gas compositions, a simple method for field measurement based on polarization spectroscopy is developed, that includes all the excitation mechanisms. To simultaneously test the flexibility of the fitting procedure and investigate the excessive broadening, we applied the fitting procedure on line profiles obtained at a range of conditions from two different discharges. The range of pressures and voltages was examined in an abnormal glow and in dielectric barrier discharge operating with hydrogen gas. The model fitting function was able to respond and follow the change in the line profile caused by the change of conditions. This procedure can therefore be recommended for electric field measurement. Contribution to the "Topical Issue: Physics of Ionized Gases (SPIG 2016)", edited by Goran Poparic, Bratislav Obradovic, Dragana Maric and Aleksandar Milosavljevic.

Experimental and theoretical excess molar enthalpies of ternary and binary mixtures containing 2-Methoxy-2-Methylpropane, 1-propanol, heptane

International Nuclear Information System (INIS)

Mato, Marta M.; Cebreiro, Susana M.; Paz Andrade, María Inmaculada; Legido, José Luis

2013-01-01

Highlights: • Experimental enthalpies for the ternary system MTBE + propanol + heptane were measured. • No experimental ternary values were found in the currently available literature. • Experimental enthalpies for the binary system propanol + heptane were measured. • Excess molar enthalpies are positive over the whole range of composition. • The ternary contribution is also positive, and the representation is asymmetric. -- Abstract: Excess molar enthalpies, at the temperature of 298.15 K and atmospheric pressure, have been measured for the ternary system {x 1 2-Methoxy-2-Methylpropane (MTBE) + x 2 1-propanol + (1 − x 1 − x 2 ) heptane}, over the whole composition range. Also, experimental data of excess molar enthalpy for the involved binary mixture {x 1-propanol + (1 − x) heptane} at the 298.15 K and atmospheric pressure, are reported. We are not aware of any previous experimental measurement of excess enthalpy in the literature for the ternary system presented in this study. Values of the excess molar enthalpies were measured using a Calvet microcalorimeter. The ternary contribution to the excess enthalpy was correlated with the equation due to Morris et al. (1975) [15], and the equation proposed by Myers–Scott (1963) [14] was used to fitted the experimental binary mixture measured in this work. Additionally, the experimental results are compared with the estimations obtained by applying the group contribution model of UNIFAC, in the versions of Larsen et al. (1987) [16] and Gmehling et al. (1993) [17]. Several empirical expressions for estimating ternary properties from binary results were also tested

Conventional Physics can Explain Excess Heat in the Fleischmann-Pons Cold Fusion Effect

Science.gov (United States)

Chubb, Scott

2011-03-01

In 1989, when Fleischmann and Pons (FP) claimed they had created room temperature, nuclear fusion in a solid, a firestorm of controversy erupted. Beginning in 1991, the Office of Naval Research began a decade-long study of the FP excess heat effect. This effort documented the fact that the excess heat that FP observed is the result of a form of nuclear fusion that can occur in solids at reduced temperature, dynamically, through a deuteron (d)+d?helium-4 reaction, without high-energy particles or ? rays. This fact has been confirmed at SRI and at a number of other laboratories (most notably in the laboratory of Y. Arata, located at Osaka University, Japan). A key reason this fact has not been accepted is the lack of a cogent argument, based on fundamental physical ideas, justifying it. In the paper, this question is re-examined, based on a generalization of conventional energy band theory that applies to finite, periodic solids, in which d's are allowed to occupy wave-like, ion band states, similar to the kinds of states that electrons occupy in ordinary metals. Prior to being experimentally observed, the Ion Band State Theory of cold fusion predicted a potential d+d?helium-4 reaction, without high energy particles, would explain the excess heat, the helium-4 would be found in an unexpected place (outside heat- producing electrodes), and high-loading, x?1, in PdDx, would be required.

12 CFR 740.3 - Advertising of excess insurance.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Advertising of excess insurance. 740.3 Section... ACCURACY OF ADVERTISING AND NOTICE OF INSURED STATUS § 740.3 Advertising of excess insurance. Any advertising that mentions share or savings account insurance provided by a party other than the NCUA must...

Hostility among adolescents in Switzerland? multivariate relations between excessive media use and forms of violence.

Science.gov (United States)

Kuntsche, Emmanuel N

2004-03-01

To determine what kind of violence-related behavior or opinion is directly related to excessive media use among adolescents in Switzerland. A national representative sample of 4222 schoolchildren (7th- and 8th-graders; mean age 13.9 years) answered questions on the frequency of television-viewing, electronic game-playing, feeling unsafe at school, bullying others, hitting others, and fighting with others, as part of the Health Behaviour in School-Aged Children (HBSC) international collaborative study protocol. The Chi-square tests and multiple logistic regression analyses were applied to high-risk groups of adolescents. For the total sample, all bivariate relationships between television-viewing/electronic game-playing and each violence-related variable are significant. In the multivariate comparison, physical violence among boys ceases to be significant. For girls, only television-viewing is linked to indirect violence. Against the hypothesis, females' electronic game-playing only had a bearing on hitting others. Experimental designs are needed that take into account gender, different forms of media, and violence to answer the question of whether excessive media use leads to violent behavior. With the exception of excessive electronic game-playing among girls, this study found that electronic media are not thought to lead directly to real-life violence but to hostility and indirect violence.

Iodine Excess is a Risk Factor for Goiter Formation

African Journals Online (AJOL)

Key Words: Iodine excess, Goiter, Sub Saharan Africa. Iodine Excess is a ... synthesis leading to increased thyroid stimulating hormone ..... study done in Uganda revealed a similar picture ... significant association, probably due to recall bias.

State dependent pseudo-resonances and excess noise

OpenAIRE

Papoff, F.; D'Alessandro, G.; Oppo, G.Luca

2008-01-01

We show that strong response to nonresonant modulations and excess noise are state dependent in generic nonlinear systems; i.e., they affect some output states but are absent from others. This is demonstrated in complex Swift-Hohenberg models relevant to optics, where it is caused by the non-normality of the linearized stability operators around selected output states, even though the cavity modes are orthogonal. In particular, we find the effective parameters that control excess noise and th...

Romanian welfare state between excess and failure

Directory of Open Access Journals (Sweden)

Cristina Ciuraru-Andrica

2012-12-01

Full Text Available Timely or not, our issue can bring back to life some prolific discussions, sometimes diametrical. We strike the social assistance, where, at this moment, is still uncertain if, once unleashed the excess, the failure will come inevitably or there is a “Salvation Ark”. However, the difference between the excess and the failure of the welfare state is almost intangible, the reason of his potential failure being actually the abuses made until the start of depression.

30 CFR 75.323 - Actions for excessive methane.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Actions for excessive methane. 75.323 Section... excessive methane. (a) Location of tests. Tests for methane concentrations under this section shall be made.... (1) When 1.0 percent or more methane is present in a working place or an intake air course, including...

Unexpected role of excess noise in spontaneous emission

International Nuclear Information System (INIS)

Lamprecht, C.; Ritsch, H.

2002-01-01

A single inverted two-level atom is used as a theoretical model for a quantum noise detector to investigate fundamental properties of excess noise in an unstable optical resonator. For a symmetric unstable spherical mirror cavity, we develop an analytic quantum description of the field in terms of a complete set of normalizable biorthogonal quasimodes and adjoint modes. Including the interaction with a single two-level atom leads to a description analogous to the Jaynes-Cummings model with modified coupling constants. One finds a strong position and geometry-dependent atomic decay probability proportional to the square root √(K) of the excess noise factor K at the cavity center. Introducing an additional homogeneous gain one recovers the K-fold emission enhancement that has been predicted before for the linewidth of an unstable cavity laser. We find that excess noise may be viewed as a spatial redistribution of the field quantum noise inside the resonator. Taking a position average of the atomic decay rate over the cavity volume leads to a cancellation of the excess noise enhancement

Applied regression analysis a research tool

CERN Document Server

Pantula, Sastry; Dickey, David

1998-01-01

Least squares estimation, when used appropriately, is a powerful research tool. A deeper understanding of the regression concepts is essential for achieving optimal benefits from a least squares analysis. This book builds on the fundamentals of statistical methods and provides appropriate concepts that will allow a scientist to use least squares as an effective research tool. Applied Regression Analysis is aimed at the scientist who wishes to gain a working knowledge of regression analysis. The basic purpose of this book is to develop an understanding of least squares and related statistical methods without becoming excessively mathematical. It is the outgrowth of more than 30 years of consulting experience with scientists and many years of teaching an applied regression course to graduate students. Applied Regression Analysis serves as an excellent text for a service course on regression for non-statisticians and as a reference for researchers. It also provides a bridge between a two-semester introduction to...

A floating water bridge produces water with excess charge

Science.gov (United States)

Fuchs, Elmar C.; Sammer, Martina; Wexler, Adam D.; Kuntke, Philipp; Woisetschläger, Jakob

2016-03-01

Excess positive and negative Bjerrum-defect like charge (protonic and ‘aterprotonic’, from ancient Greek ἄ'τɛρ, ‘without’) in anolyte and catholyte of high voltage electrolysis of highly pure water was found during the so-called ‘floating water bridge’ experiment. The floating water bridge is a special case of an electrohydrodynamic liquid bridge and constitutes an intriguing phenomenon that occurs when a high potential difference (~kV cm-1) is applied between two beakers of water. To obtain such results impedance spectroscopy was used. This measurement technique allows the depiction and simulation of complex aqueous systems as simple electric circuits. In the present work we show that there is an additional small contribution from the difference in conductivity between anolyte and catholyte which cannot be measured with a conductivity meter, but is clearly visible in an impedance spectrum.

Verification of excess defense material

International Nuclear Information System (INIS)

Fearey, B.L.; Pilat, J.F.; Eccleston, G.W.; Nicholas, N.J.; Tape, J.W.

1997-01-01

The international community in the post-Cold War period has expressed an interest in the International Atomic Energy Agency (IAEA) using its expertise in support of the arms control and disarmament process in unprecedented ways. The pledges of the US and Russian presidents to place excess defense materials under some type of international inspections raises the prospect of using IAEA safeguards approaches for monitoring excess materials, which include both classified and unclassified materials. Although the IAEA has suggested the need to address inspections of both types of materials, the most troublesome and potentially difficult problems involve approaches to the inspection of classified materials. The key issue for placing classified nuclear components and materials under IAEA safeguards is the conflict between these traditional IAEA materials accounting procedures and the US classification laws and nonproliferation policy designed to prevent the disclosure of critical weapon-design information. Possible verification approaches to classified excess defense materials could be based on item accountancy, attributes measurements, and containment and surveillance. Such approaches are not wholly new; in fact, they are quite well established for certain unclassified materials. Such concepts may be applicable to classified items, but the precise approaches have yet to be identified, fully tested, or evaluated for technical and political feasibility, or for their possible acceptability in an international inspection regime. Substantial work remains in these areas. This paper examines many of the challenges presented by international inspections of classified materials

Excess Early Mortality in Schizophrenia

DEFF Research Database (Denmark)

Laursen, Thomas Munk; Nordentoft, Merete; Mortensen, Preben Bo

2014-01-01

Schizophrenia is often referred to as one of the most severe mental disorders, primarily because of the very high mortality rates of those with the disorder. This article reviews the literature on excess early mortality in persons with schizophrenia and suggests reasons for the high mortality...... as well as possible ways to reduce it. Persons with schizophrenia have an exceptionally short life expectancy. High mortality is found in all age groups, resulting in a life expectancy of approximately 20 years below that of the general population. Evidence suggests that persons with schizophrenia may...... not have seen the same improvement in life expectancy as the general population during the past decades. Thus, the mortality gap not only persists but may actually have increased. The most urgent research agenda concerns primary candidates for modifiable risk factors contributing to this excess mortality...

Severe rhabdomyolysis after excessive bodybuilding.

Science.gov (United States)

Finsterer, J; Zuntner, G; Fuchs, M; Weinberger, A

2007-12-01

A 46-year-old male subject performed excessive physical exertion during 4-6 h in a studio for body builders during 5 days. He was not practicing sport prior to this training and denied the use of any aiding substances. Despite muscle aching already after 1 day, he continued the exercises. After the last day, he recognized tiredness and cessation of urine production. Two days after discontinuation of the training, a Herpes simplex infection occurred. Because of acute renal failure, he required hemodialysis. There were absent tendon reflexes and creatine kinase (CK) values up to 208 274 U/L (normal: <170 U/L). After 2 weeks, CK had almost normalized and, after 4 weeks, hemodialysis was discontinued. Excessive muscle training may result in severe, hemodialysis-dependent rhabdomyolysis. Triggering factors may be prior low fitness level, viral infection, or subclinical metabolic myopathy.

Heat-related mortality in India: excess all-cause mortality associated with the 2010 Ahmedabad heat wave.

Directory of Open Access Journals (Sweden)

Gulrez Shah Azhar

Full Text Available In the recent past, spells of extreme heat associated with appreciable mortality have been documented in developed countries, including North America and Europe. However, far fewer research reports are available from developing countries or specific cities in South Asia. In May 2010, Ahmedabad, India, faced a heat wave where the temperatures reached a high of 46.8 °C with an apparent increase in mortality. The purpose of this study is to characterize the heat wave impact and assess the associated excess mortality.We conducted an analysis of all-cause mortality associated with a May 2010 heat wave in Ahmedabad, Gujarat, India, to determine whether extreme heat leads to excess mortality. Counts of all-cause deaths from May 1-31, 2010 were compared with the mean of counts from temporally matched periods in May 2009 and 2011 to calculate excess mortality. Other analyses included a 7-day moving average, mortality rate ratio analysis, and relationship between daily maximum temperature and daily all-cause death counts over the entire year of 2010, using month-wise correlations.The May 2010 heat wave was associated with significant excess all-cause mortality. 4,462 all-cause deaths occurred, comprising an excess of 1,344 all-cause deaths, an estimated 43.1% increase when compared to the reference period (3,118 deaths. In monthly pair-wise comparisons for 2010, we found high correlations between mortality and daily maximum temperature during the locally hottest "summer" months of April (r = 0.69, p<0.001, May (r = 0.77, p<0.001, and June (r = 0.39, p<0.05. During a period of more intense heat (May 19-25, 2010, mortality rate ratios were 1.76 [95% CI 1.67-1.83, p<0.001] and 2.12 [95% CI 2.03-2.21] applying reference periods (May 12-18, 2010 from various years.The May 2010 heat wave in Ahmedabad, Gujarat, India had a substantial effect on all-cause excess mortality, even in this city where hot temperatures prevail through much of April-June.

Excess Sodium Tetraphenylborate and Intermediates Decomposition Studies

Energy Technology Data Exchange (ETDEWEB)

Barnes, M.J. [Westinghouse Savannah River Company, AIKEN, SC (United States); Peterson , R.A.

1998-04-01

The stability of excess amounts of sodium tetraphenylborate (NaTPB) in the In-Tank Precipitation (ITP) facility depends on a number of variables. Concentration of palladium, initial benzene, and sodium ion as well as temperature provide the best opportunities for controlling the decomposition rate. This study examined the influence of these four variables on the reactivity of palladium-catalyzed sodium tetraphenylborate decomposition. Also, single effects tests investigated the reactivity of simulants with continuous stirring and nitrogen ventilation, with very high benzene concentrations, under washed sodium concentrations, with very high palladium concentrations, and with minimal quantities of excess NaTPB. These tests showed the following.The testing demonstrates that current facility configuration does not provide assured safety of operations relative to the hazards of benzene (in particular to maintain the tank headspace below 60 percent of the lower flammability limit (lfl) for benzene generation rates of greater than 7 mg/(L.h)) from possible accelerated reaction of excess NaTPB. Current maximal operating temperatures of 40 degrees C and the lack of protection against palladium entering Tank 48H provide insufficient protection against the onset of the reaction. Similarly, control of the amount of excess NaTPB, purification of the organic, or limiting the benzene content of the slurry (via stirring) and ionic strength of the waste mixture prove inadequate to assure safe operation.

Excess Sodium Tetraphenylborate and Intermediates Decomposition Studies

International Nuclear Information System (INIS)

Barnes, M.J.; Peterson, R.A.

1998-04-01

The stability of excess amounts of sodium tetraphenylborate (NaTPB) in the In-Tank Precipitation (ITP) facility depends on a number of variables. Concentration of palladium, initial benzene, and sodium ion as well as temperature provide the best opportunities for controlling the decomposition rate. This study examined the influence of these four variables on the reactivity of palladium-catalyzed sodium tetraphenylborate decomposition. Also, single effects tests investigated the reactivity of simulants with continuous stirring and nitrogen ventilation, with very high benzene concentrations, under washed sodium concentrations, with very high palladium concentrations, and with minimal quantities of excess NaTPB. These tests showed the following.The testing demonstrates that current facility configuration does not provide assured safety of operations relative to the hazards of benzene (in particular to maintain the tank headspace below 60 percent of the lower flammability limit (lfl) for benzene generation rates of greater than 7 mg/(L.h)) from possible accelerated reaction of excess NaTPB. Current maximal operating temperatures of 40 degrees C and the lack of protection against palladium entering Tank 48H provide insufficient protection against the onset of the reaction. Similarly, control of the amount of excess NaTPB, purification of the organic, or limiting the benzene content of the slurry (via stirring) and ionic strength of the waste mixture prove inadequate to assure safe operation

Sanitization and Disposal of Excess Information Technology Equipment

Science.gov (United States)

2009-09-21

Report No. D-2009-104 September 21, 2009 Sanitization and Disposal of Excess Information Technology Equipment...2009 2. REPORT TYPE 3. DATES COVERED 00-00-2009 to 00-00-2009 4. TITLE AND SUBTITLE Sanitization and Disposal of Excess Information Technology ...Defense (Networks and Information Integration)/DOD Chief Information Officer DRMS Defense Reutilization and Marketing Service IT Information

Excessive behaviors in clinical practice--A state of the art article.

Science.gov (United States)

Punzi, Elisabeth H

2016-01-01

This paper concerns difficulties with excessive food intake, sexual activities, romantic relationships, gambling, Internet use, shopping, and exercise-behaviors that might cause considerable suffering. Excessive behaviors are seen as expressions of underlying difficulties that often co-occur with other psychological difficulties, and behaviors may accompany or replace each other. Moreover, they might pass unnoticed in clinical practice. Given the complexity of excessive behaviors, integrated and individualized treatment has been recommended. This paper presents an overview of the terminology concerning excessive behaviors, and the impact of naming is acknowledged. Thereafter, methods for identification and assessment, as well as treatment needs are discussed. Because identification, assessment, and treatment occur in an interaction between client and practitioner, this paper presents a discussion of the need to empower practitioners to identify and assess excessive behaviors and provide an integrated treatment. Moreover, the need to support practitioners' capacity to handle and tolerate the overwhelming suffering and the negative consequences connected to excessive behaviors is discussed. Qualitative studies are suggested in order to understand the meaning of excessive behaviors, treatment needs, and the interaction between client and practitioner.

Spatially resolving the dust properties and submillimetre excess in M 33

Science.gov (United States)

Relaño, M.; De Looze, I.; Kennicutt, R. C.; Lisenfeld, U.; Dariush, A.; Verley, S.; Braine, J.; Tabatabaei, F.; Kramer, C.; Boquien, M.; Xilouris, M.; Gratier, P.

2018-05-01

Context. The relative abundance of the dust grain types in the interstellar medium is directly linked to physical quantities that trace the evolution of galaxies. Because of the poor spatial resolution of the infrared and submillimetre data, we are able to study the dependence of the resolved infrared spectral energy distribution (SED) across regions of the interstellar medium (ISM) with different physical properties in just a few objects. Aims: We aim to study the dust properties of the whole disc of M 33 at spatial scales of 170 pc. This analysis allows us to infer how the relative dust grain abundance changes with the conditions of the ISM, study the existence of a submillimetre excess and look for trends of the gas-to-dust mass ratio (GDR) with other physical properties of the galaxy. Methods: For each pixel in the disc of M 33 we have fitted the infrared SED using a physically motivated dust model that assumes an emissivity index β close to two. We applied a Bayesian statistical method to fit the individual SEDs and derived the best output values from the study of the probability density function of each parameter. We derived the relative amount of the different dust grains in the model, the total dust mass, and the strength of the interstellar radiation field (ISRF) heating the dust at each spatial location. Results: The relative abundance of very small grains tends to increase, and for big grains to decrease, at high values of Hα luminosity. This shows that the dust grains are modified inside the star-forming regions, in agreement with a theoretical framework of dust evolution under different physical conditions. The radial dependence of the GDR is consistent with the shallow metallicity gradient observed in this galaxy. The strength of the ISRF derived in our model correlates with the star formation rate in the galaxy in a pixel by pixel basis. Although this is expected, it is the first time that a correlation between the two quantities has been reported

Alteration of Diastereoisomeric and Enantiomeric Profiles of Hexabromocyclododecanes (HBCDs) in Adult Chicken Tissues, Eggs, and Hatchling Chickens.

Science.gov (United States)

Zheng, Xiaobo; Qiao, Lin; Sun, Runxia; Luo, Xiaojun; Zheng, Jing; Xie, Qilai; Sun, Yuxin; Mai, Bixian

2017-05-16

The concentrations and enantiomer fractions (EFs) of α-, β-, and γ-hexabromocyclododecanes (HBCDs) were measured in chicken diet sources (soil and chicken feed), home-raised adult chicken (Gallus domesticus) tissues, eggs during incubation, and hatchling chicken tissues. HBCD concentrations were not detected-0.69 ng/g dry weight (dw) and 25.6-48.4 ng/g dw in chicken feed and soil, respectively. HBCDs were detected in all adult chicken tissues, except the brain, at median levels of 13.1-44.0 ng/g lipid weight (lw). The proportions of α-HBCD in total HBCDs increased from 51% in soil to more than 87% in adult chicken tissues. The accumulation ratios (ARs) of α-HBCD from diet to adult chicken tissues were 4.27 for liver, 11.2 for fat, and 7.64-12.9 for other tissues, respectively. The AR and carry-over rate (COR) of α-HBCD from diet to eggs were 22.4 and 0.226, respectively. The concentrations of α-HBCD in hatchling chicken liver (median: 35.4 ng/g lw) were significantly lower than those in hatchling chicken pectoral muscle (median: 130 ng/g lw). The EFs of α-HBCD decreased from soil to adult chicken tissues and from eggs to hatchling chicken liver. Meanwhile, the EFs of γ-HBCD increased from soil to adult chicken tissues. These results indicate the preferential enrichment of (-)-α-HBCD and (+)-γ-HBCD in chickens. The alteration of diastereoisomeric and enantiomeric patterns of HBCDs might be influenced by the different absorption and elimination rates of the six HBCD enantiomers as well as variations in HBCD metabolism in chickens.

An update on the LHC monojet excess

Science.gov (United States)

Asadi, Pouya; Buckley, Matthew R.; DiFranzo, Anthony; Monteux, Angelo; Shih, David

2018-03-01

In previous work, we identified an anomalous number of events in the LHC jets+MET searches characterized by low jet multiplicity and low-to-moderate transverse energy variables. Here, we update this analysis with results from a new ATLAS search in the monojet channel which also shows a consistent excess. As before, we find that this "monojet excess" is well-described by the resonant production of a heavy colored state decaying to a quark and a massive invisible particle. In the combined ATLAS and CMS data, we now find a local (global) preference of 3.3 σ (2.5 σ) for the new physics model over the Standard Model-only hypothesis. As the signal regions containing the excess are systematics-limited, we consider additional cuts to enhance the signal-to-background ratio. We show that binning finer in H T and requiring the jets to be more central can increase S/B by a factor of ˜1 .5.

Excess 129Xe in terrestrial samples: A non-primordial hypothesis

International Nuclear Information System (INIS)

Caffee, M.W.; Hudson, G.B.

1987-03-01

Excesses of 129 Xe relative to the isotopic composition in air are observed in some terrestrial samples. Traditionally these 129 Xe excesses have been thought to be related to 129 I that was present in abundance in the early solar system. We propose an alternative hypothesis to explain terrestrial 129 Xe excesses based on the production of 129 I from the spontaneous fission of 238 U

Excess molar enthalpies for binary mixtures of different amines with water

International Nuclear Information System (INIS)

Zhang, Ruilei; Chen, Jian; Mi, Jianguo

2015-01-01

Highlights: • Isothermal excess molar enthalpies for binary mixtures of different amines with water. • The Redlich–Kister equation and the NRTL model was used to fit the experimental data. • The excess molar enthalpies were discussed with different structures of amines. - Abstract: The isothermal excess molar enthalpies for binary mixtures of different amines with water were measured with a C-80 Setaram calorimeter. The experimental results indicate that the excess molar enthalpy is related to the molecular structure. The experimental excess molar enthalpies were satisfactorily fitted with the Redlich–Kister equation. They were also used to test the suitability of the NRTL model, and the deviations are a little larger than the R–K equation

Thermophysical and excess properties of hydroxamic acids in DMSO

International Nuclear Information System (INIS)

Thakur, Piyush Kumar; Patre, Sandhya; Pande, Rama

2013-01-01

Graphical abstract: Excess molar volumes (V E ) vs mole fraction (x 2 ) of (A) N-o-tolyl-2-nitrobenzo- and (B) N-o-tolyl-4-nitrobenzo-hydroxamic acids in DMSO at different temperatures: ■, 298.15 K; ▪, 303.15 K; ▪, 308.15 K; ▪, 313.15 K; and ▪, 318.15 K. Highlights: ► ρ, n of the system hydroxamic acids in DMSO are reported. ► Apparent molar volume indicates superior solute–solvent interactions. ► Limiting apparent molar expansibility and coefficient of thermal expansion. ► Behaviour of this parameter suggest to hydroxamic acids act as structure maker. ► The excess properties have interpreted in terms of molecular interactions. -- Abstract: In this work, densities (ρ) and refractive indices (n) of N-o-tolyl-2-nitrobenzo- and N-o-tolyl-4-nitrobenzo-, hydroxamic acids have been determined for dimethyl sulfoxide (DMSO) as a function of their concentrations at T = (298.15, 303.15, 308.15, 313.15, and 318.15) K. These measurements were carried out to evaluate some important parameters, viz, molar volume (V), apparent molar volume (V ϕ ), limiting apparent molar volume (V ϕ 0 ), slope (S V ∗ ), molar refraction (R M ) and polarizability (α). The related parameters determined are limiting apparent molar expansivity (ϕ E 0 ), thermal expansion coefficient (α 2 ) and the Hepler constant (∂ 2 V ϕ 0 /∂T 2 ). Excess properties such as excess molar volume (V E ), deviations from the additivity rule of refractive index (n E ), excess molar refraction (R M E ) have also been evaluated. The excess properties were fitted to the Redlich–Kister equations to estimate their coefficients and standard deviations were determined. The variations of these excess parameters with composition were discussed from the viewpoint of intermolecular interactions in these solutions. The excess properties are found to be either positive or negative depending on the molecular interactions and the nature of solutions. Further, these parameters have been interpreted

Automated synthesis of n.c.a. [18F]FDOPA via nucleophilic aromatic substitution with [18F]fluoride

International Nuclear Information System (INIS)

Shen, B.; Ehrlichmann, W.; Uebele, M.; Machulla, H.-J.; Reischl, G.

2009-01-01

An improved, automated synthesis of [ 18 F]FDOPA including four synthetic steps (fluorination, reductive iodination, alkylation and hydrolysis) is reported with each step optimized individually. In a home-made automatic synthesizer, 9064±3076 MBq of [ 18 F]FDOPA were produced within 120 min from EOB (n=5). Radiochemical purity and enantiomeric excess were both ≥95%. Specific activity was ca. 50 GBq/μmol at EOS. This automatically operable synthesis is well suited for the multi-patient-dose routine production of n.c.a. [ 18 F]FDOPA.

Solvent Effects in Asymmetric Hetero Diels-Alder and Ene Reactions

DEFF Research Database (Denmark)

Johannsen, Mogens; Jørgensen, Karl Anker

1996-01-01

The use of polar solvents such as nitromethane or 2-nitropropane leads to a significant improvement of the catalytic properties of a cationic copper-Lewis acid in the hetero Diels-Alder reaction of alkyl glyoxylates with dienes; The scope of a newly developed copper(II)-bisoxazoline catalyst...... for the hetero Diels-Alder reaction is demonstrated by the reaction of different dienes with alkyl glyoxylates in nitroalkane solvents with the formation of the hetero Diels-Alder adduct in high enantiomeric excess as the major product. The synthetic application of the reaction is exemplified by an improved...

Synthesis of α,ω-polyfluorinated α-amino acid derivatives and δ,δ-difluoronorvaline.

Science.gov (United States)

Ulbrich, Dirk; Daniliuc, Constantin G; Haufe, Günter

2016-03-07

Intending to synthesize ω,ω-difluoroalkyl amino acid derivatives by oxidative desulfurization-fluorination reactions of suitable arylthio-2-phthalimido butanoates and pentanoates, in addition to small amounts of the target products, mainly α,ω-polyfluorinated amino acid derivatives were formed by additional sulfur-assisted α-fluorination. This novel structural motif was verified spectroscopically as well as by X-ray analysis. A plausible mechanism of formation is suggested. Using a different approach, δ,δ-difluoronorvaline hydrochloride was synthesized with at least 36% enantiomeric excess via deoxofluorination of the corresponding aldehyde.

A General Asymmetric Synthesis of (R-Matsutakeol and Flavored Analogs

Directory of Open Access Journals (Sweden)

Jia Liu

2017-02-01

Full Text Available An efficient and practical synthetic route toward chiral matsutakeol and analogs was developed by asymmetric addition of terminal alkyne to aldehydes. (R-matsutakeol and other flavored substances were feasibly synthesized from various alkylaldehydes in high yield (up to 49.5%, in three steps and excellent enantiomeric excess (up to >99%. The protocols may serve as an alternative asymmetric synthetic method for active small-molecule library of natural fatty acid metabolites and analogs. These chiral allyl alcohols are prepared for food analysis and screening insect attractants.

Enantioselective synthesis of α-oxy amides via Umpolung amide synthesis.

Science.gov (United States)

Leighty, Matthew W; Shen, Bo; Johnston, Jeffrey N

2012-09-19

α-Oxy amides are prepared through enantioselective synthesis using a sequence beginning with a Henry addition of bromonitromethane to aldehydes and finishing with Umpolung Amide Synthesis (UmAS). Key to high enantioselection is the finding that ortho-iodo benzoic acid salts of the chiral copper(II) bis(oxazoline) catalyst deliver both diastereomers of the Henry adduct with high enantiomeric excess, homochiral at the oxygen-bearing carbon. Overall, this approach to α-oxy amides provides an innovative complement to alternatives that focus almost entirely on the enantioselective synthesis of α-oxy carboxylic acids.

Bioreduction of substituted α-tetralones promoted by Daucus carota root

International Nuclear Information System (INIS)

Ferraz, Helena M.C.; Bianco, Graziela G.; Bombonato, Fernanda I.; Andrade, Leandro H.; Porto, Andre L.M.

2008-01-01

The bioreduction of a series of substituted α-tetralones, carried out using Daucus carota root (carrot), afforded the corresponding homochiral α-tetralols in variable conversions (9 to 90%) and excellent enantiomeric excesses. Two of the assayed α-tetralones were resistant to the bioreduction conditions. The absolute configurations of four α-tetralols were assigned as being (S), by comparison to the (S)-enantiomers obtained by kinetic resolution promoted by CALB-catalysed acetylation. Additionally, the new 5-methoxy-6-methyl-1-tetralone was synthesized in seven steps from 3-methylsalicylic acid. (author)

A Practical Approach For Excess Bandwidth Distribution for EPONs

KAUST Repository

Elrasad, Amr

2014-03-09

This paper introduces a novel approach called Delayed Excess Scheduling (DES), which practically reuse the excess bandwidth in EPONs system. DES is suitable for the industrial deployment as it requires no timing constraint and achieves better performance compared to the previously reported schemes.

Subdwarf ultraviolet excesses and metal abundances

International Nuclear Information System (INIS)

Carney, B.W.

1979-01-01

The relation between stellar ultraviolet excesses and abundances is reexamined with the aid of new data, and an investigation is made of the accuracy of previous abundance analyses. A high-resolution echellogram of the subdwarf HD 201891 is analyzed to illustrate some of the problems. Generally, the earliest and latest analytical techniques yield consistent results for dwarfs. New UBV data yield normalized ultraviolet excesses, delta (U-B)/sub 0.6/, which are compared to abundances to produce a graphical relation that may be used to estimate [Fe/H] to +- 0.2 dex, given UBV colors accurate to +- 0.01 mag. The relation suggests a possible discontinuity between the halo and old-disk stars

Excessive behaviors in clinical practice—A state of the art article

Directory of Open Access Journals (Sweden)

Elisabeth H. Punzi

2016-02-01

Full Text Available This paper concerns difficulties with excessive food intake, sexual activities, romantic relationships, gambling, Internet use, shopping, and exerciseߞbehaviors that might cause considerable suffering. Excessive behaviors are seen as expressions of underlying difficulties that often co-occur with other psychological difficulties, and behaviors may accompany or replace each other. Moreover, they might pass unnoticed in clinical practice. Given the complexity of excessive behaviors, integrated and individualized treatment has been recommended. This paper presents an overview of the terminology concerning excessive behaviors, and the impact of naming is acknowledged. Thereafter, methods for identification and assessment, as well as treatment needs are discussed. Because identification, assessment, and treatment occur in an interaction between client and practitioner, this paper presents a discussion of the need to empower practitioners to identify and assess excessive behaviors and provide an integrated treatment. Moreover, the need to support practitionersߞ capacity to handle and tolerate the overwhelming suffering and the negative consequences connected to excessive behaviors is discussed. Qualitative studies are suggested in order to understand the meaning of excessive behaviors, treatment needs, and the interaction between client and practitioner.

Excess electrons in reduced rutile and anatase TiO2

Science.gov (United States)

Yin, Wen-Jin; Wen, Bo; Zhou, Chuanyao; Selloni, Annabella; Liu, Li-Min

2018-05-01

As a prototypical photocatalyst, TiO2 is a material of scientific and technological interest. In photocatalysis and other applications, TiO2 is often reduced, behaving as an n-type semiconductor with unique physico-chemical properties. In this review, we summarize recent advances in the understanding of the fundamental properties and applications of excess electrons in reduced, undoped TiO2. We discuss the characteristics of excess electrons in the bulk and at the surface of rutile and anatase TiO2 focusing on their localization, spatial distribution, energy levels, and dynamical properties. We examine specific features of the electronic states for photoexcited TiO2, for intrinsic oxygen vacancy and Ti interstitial defects, and for surface hydroxyls. We discuss similarities and differences in the behaviors of excess electrons in the rutile and anatase phases. Finally, we consider the effect of excess electrons on the reactivity, focusing on the interaction between excess electrons and adsorbates.

Targets to treat androgen excess in polycystic ovary syndrome.

Science.gov (United States)

Luque-Ramírez, Manuel; Escobar-Morreale, Héctor Francisco

2015-01-01

The polycystic ovary syndrome (PCOS) is a common androgen disorder in reproductive-aged women. Excessive biosynthesis and secretion of androgens by steroidogenic tissues is its central pathogenetic mechanism. The authors review the potential targets and new drugs to treat androgen excess in PCOS. Besides our lab's experience, a systematic search (MEDLINE, Cochrane library, ClinicalTriasl.gov, EU Clinical Trials Register and hand-searching) regarding observational studies, randomized clinical trials, systematic reviews, meta-analyses and patents about this topic was performed. PCOS has a heterogeneous clinical presentation. It is unlikely that a single drug would cover all its possible manifestations. Available treatments for androgen excess are not free of side effects that are of particular concern in these women who suffer from cardiometabolic risk even without treatment. A precise characterization of the source of androgen excess must tailor antiandrogenic management in each woman, avoiding undesirable side effects.

Disposition of excess weapons plutonium from dismantled weapons

International Nuclear Information System (INIS)

Jardine, L.J.

1997-01-01

With the end of the Cold War and the implementation of various nuclear arms reduction agreements, US and Russia have been actively dismantling tens of thousands of nuclear weapons. As a result,large quantities of fissile materials, including more than 100 (tonnes?) of weapons-grade Pu, have become excess to both countries' military needs. To meet nonproliferation goals and to ensure the irreversibility of nuclear arms reductions, this excess weapons Pu must be placed in secure storage and then, in timely manner, either used in nuclear reactors as fuel or discarded in geologic repositories as solid waste. This disposition in US and Russia must be accomplished in a safe, secure manner and as quickly as practical. Storage of this Pu is a prerequisite to any disposition process, but the length of storage time is unknown. Whether by use as fuel or discard as solid waste, disposition of that amount of Pu will require decades--and perhaps longer, if disposition operations encounter delays. Neither US nor Russia believes that long-term secure storage is a substitute for timely disposition of excess Pu, but long-term, safe, secure storage is a critical element of all excess Pu disposition activities

Identification and Evaluation of Cases for Excess Heat Utilisation Using GIS

DEFF Research Database (Denmark)

Bühler, Fabian; Petrovic, Stefan; Ommen, Torben Schmidt

2018-01-01

Excess heat is present in many sectors, and its utilization could reduce the primary energy use and emission of greenhouse gases. This work presents a geographical mapping of excess heat, in which excess heat from the industry and utility sector was distributed to specific geographical locations...

Steroidogenic alterations and adrenal androgen excess in PCOS.

Science.gov (United States)

Doi, Suhail A R; Al-Zaid, Mona; Towers, Philip A; Scott, Christopher J; Al-Shoumer, Kamal A S

2006-09-01

This cross-sectional study was undertaken to improve our understanding of the steroidogenic alterations leading to adrenal hyperandrogenism in polycystic ovarian syndrome (PCOS). Two-hundred and thirty-four women with clinical and biochemical features suggestive of PCOS underwent metabolic and hormonal evaluation. We used the androstenedione/DHEAS ratio as a surrogate for the level of ovarian 3betaHSD activity. We then selected the 90th percentile for the ratio in those with elevated DHEAS (>9 micromol/l) as the cut-off level beyond which excess DHEAS production will be minimized by excess ovarian 3betaHSD activity. This cut-off level was at a ratio of 1.5 and all PCOS women were then divided into two groups, the higher (>1.5) being the group with excess ovarian 3betaHSD activity. We hypothesized that women with a high ratio would be unlikely to have DHEAS excess due to the rapid conversion of DHEA to androstenedione. Those with a low ratio (concordant ovarian and adrenal steroidogenesis) could then either have high DHEAS or normal DHEAS, depending on whether CYP17 activity was higher or lower respectively. Insulin resistance was found to be associated with decreased CYP17 activity while irregular cycles and neuroendocrine dysfunction were determined to be associated with higher ovarian 3betaHSD activity. Adrenal androgen excess in PCOS seems to be related to insulin sensitivity as well as decreased activity of 3betaHSD, the latter being preferentially present in those women with regular cycles or without neuroendocrine dysfunction.

[Excessive computer usage in adolescents--results of a psychometric evaluation].

Science.gov (United States)

Grüsser, Sabine M; Thalemann, Ralf; Albrecht, Ulrike; Thalemann, Carolin N

2005-03-01

Excessive computer and video game playing among children is being critically discussed from a pedagogic and public health point of view. To date, no reliable data for this phenomenon in Germany exists. In the present study, the excessive usage of computer and video games is seen as a rewarding behavior which can, due to learning mechanisms, become a prominent and inadequate strategy for children to cope with negative emotions like frustration, uneasiness and fears. In the survey, 323 children ranging in age from 11 to 14 years were asked about their video game playing behavior. Criteria for excessive computer and video game playing were developed in accordance with the criteria for dependency and pathological gambling (DSM-IV, ICD-10). Data show that 9.3% (N = 30) of the children fulfill all criteria for excessive computer and video game playing. Furthermore, these children differ from their class mates with respect to watching television, communication patterns, the ability to concentrate in school lectures and the preferred strategies coping with negative emotions. In accordance with findings in studies about substance-related addiction, data suggest that excessive computer and video game players use their excessive rewarding behavior specifically as an inadequate stress coping strategy.

The High Price of Excessive Alcohol Consumption

Centers for Disease Control (CDC) Podcasts

2011-10-17

This podcast is based on the October 2011 release of a report estimating the economic cost of excessive drinking. Excessive alcohol consumption cost the U. S. $223.5 billion in 2006, or about $1.90 per drink. Over three-quarters (76%) of these costs were due to binge drinking, defined as consuming 4 or more alcoholic beverages per occasion for women or 5 or more drinks per occasion for men.  Created: 10/17/2011 by National Center for Chronic Disease Prevention and Health Promotion.   Date Released: 10/17/2011.

On the excess energy of nonequilibrium plasma

International Nuclear Information System (INIS)

Timofeev, A. V.

2012-01-01

The energy that can be released in plasma due to the onset of instability (the excess plasma energy) is estimated. Three potentially unstable plasma states are considered, namely, plasma with an anisotropic Maxwellian velocity distribution of plasma particles, plasma with a two-beam velocity distribution, and an inhomogeneous plasma in a magnetic field with a local Maxwellian velocity distribution. The excess energy can serve as a measure of the degree to which plasma is nonequilibrium. In particular, this quantity can be used to compare plasmas in different nonequilibrium states.

A floating water bridge produces water with excess charge

International Nuclear Information System (INIS)

Fuchs, Elmar C; Sammer, Martina; Wexler, Adam D; Kuntke, Philipp; Woisetschläger, Jakob

2016-01-01

Excess positive and negative Bjerrum-defect like charge (protonic and ‘aterprotonic’, from ancient Greek ατερ, ‘without’) in anolyte and catholyte of high voltage electrolysis of highly pure water was found during the so-called ‘floating water bridge’ experiment. The floating water bridge is a special case of an electrohydrodynamic liquid bridge and constitutes an intriguing phenomenon that occurs when a high potential difference (∼kV cm −1 ) is applied between two beakers of water. To obtain such results impedance spectroscopy was used. This measurement technique allows the depiction and simulation of complex aqueous systems as simple electric circuits. In the present work we show that there is an additional small contribution from the difference in conductivity between anolyte and catholyte which cannot be measured with a conductivity meter, but is clearly visible in an impedance spectrum. (paper)

30 CFR 816.73 - Disposal of excess spoil: Durable rock fills.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Disposal of excess spoil: Durable rock fills...-SURFACE MINING ACTIVITIES § 816.73 Disposal of excess spoil: Durable rock fills. The regulatory authority may approve the alternative method of disposal of excess durable rock spoil by gravity placement in...

30 CFR 817.73 - Disposal of excess spoil: Durable rock fills.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Disposal of excess spoil: Durable rock fills...-UNDERGROUND MINING ACTIVITIES § 817.73 Disposal of excess spoil: Durable rock fills. The regulatory authority may approve the alternative method of disposal of excess durable rock spoil by gravity placement in...

Excess electron transport in cryoobjects

CERN Document Server

Eshchenko, D G; Brewer, J H; Cottrell, S P; Cox, S F J

2003-01-01

Experimental results on excess electron transport in solid and liquid phases of Ne, Ar, and solid N sub 2 -Ar mixture are presented and compared with those for He. Muon spin relaxation technique in frequently switching electric fields was used to study the phenomenon of delayed muonium formation: excess electrons liberated in the mu sup + ionization track converge upon the positive muons and form Mu (mu sup + e sup -) atoms. This process is shown to be crucially dependent upon the electron's interaction with its environment (i.e., whether it occupies the conduction band or becomes localized in a bubble of tens of angstroms in radius) and upon its mobility in these states. The characteristic lengths involved are 10 sup - sup 6 -10 sup - sup 4 cm, the characteristic times range from nanoseconds to tens microseconds. Such a microscopic length scale sometimes enables the electron spend its entire free lifetime in a state which may not be detected by conventional macroscopic techniques. The electron transport proc...

[Excess mortality associated with influenza in Spain in winter 2012].

Science.gov (United States)

León-Gómez, Inmaculada; Delgado-Sanz, Concepción; Jiménez-Jorge, Silvia; Flores, Víctor; Simón, Fernando; Gómez-Barroso, Diana; Larrauri, Amparo; de Mateo Ontañón, Salvador

2015-01-01

An excess of mortality was detected in Spain in February and March 2012 by the Spanish daily mortality surveillance system and the «European monitoring of excess mortality for public health action» program. The objective of this article was to determine whether this excess could be attributed to influenza in this period. Excess mortality from all causes from 2006 to 2012 were studied using time series in the Spanish daily mortality surveillance system, and Poisson regression in the European mortality surveillance system, as well as the FluMOMO model, which estimates the mortality attributable to influenza. Excess mortality due to influenza and pneumonia attributable to influenza were studied by a modification of the Serfling model. To detect the periods of excess, we compared observed and expected mortality. In February and March 2012, both the Spanish daily mortality surveillance system and the European mortality surveillance system detected a mortality excess of 8,110 and 10,872 deaths (mortality ratio (MR): 1.22 (95% CI:1.21-1.23) and 1.32 (95% CI: 1.29-1.31), respectively). In the 2011-12 season, the FluMOMO model identified the maximum percentage (97%) of deaths attributable to influenza in people older than 64 years with respect to the mortality total associated with influenza (13,822 deaths). The rate of excess mortality due to influenza and pneumonia and respiratory causes in people older than 64 years, obtained by the Serfling model, also reached a peak in the 2011-2012 season: 18.07 and 77.20, deaths per 100,000 inhabitants, respectively. A significant increase in mortality in elderly people in Spain was detected by the Spanish daily mortality surveillance system and by the European mortality surveillance system in the winter of 2012, coinciding with a late influenza season, with a predominance of the A(H3N2) virus, and a cold wave in Spain. This study suggests that influenza could have been one of the main factors contributing to the mortality excess

40 CFR 57.304 - Bypass, excess emissions and malfunctions.

Science.gov (United States)

2010-07-01

... (performance level of interim constant controls) or § 57.303 (plantwide emission limitation) of this subpart... limitation, as well as the operating data, documents, and calculations used in determining the magnitude of the excess emissions; (3) Time and duration of the excess emissions; (4) Identity of the equipment...

Transport of excess electrons in dense dielectric fluids. Phenomenological interpretation and application to a one-dimensional argon fluid

International Nuclear Information System (INIS)

Leycuras, A.; Larour, J.

1978-01-01

The main results about the drift velocities of excess electrons in dense argon are summarized. The weaknesses of the available theories are mainly due to poor information concerning the electron-atom potential during an atom-atom collision. The drift velocities, as a function of the applied electric field present the following features at high fields: the drift velocity reaches a limit that is at most one order of magnitude larger than the sound velocity at the same density. These remarks and the attractive nature of the electron-atom potential suggest a transport model, the collisional transfer model analog to the one applied to the determination of the sound velocity. Drift velocities obtained with this model applied to a one-dimensional molecular dynamics simulation are presented [fr

The Synergistic Impact of Excessive Drinking and Smoking upon Prospective Memory.

Directory of Open Access Journals (Sweden)

Anna-Marie eMarshall

2016-04-01

Full Text Available The independent use of excessive amounts of alcohol or persistent cigarette smoking have been found to have a deleterious impact upon Prospective Memory (PM: remembering future intentions and activities, although to date, the effect of their concurrent use upon PM is yet to be explored. The present study investigated the impact of concurrent use (excessive use of alcohol and cigarette smoking in comparison to the combined effect of the single use of these substances using a single factorial independent groups design. The Cambridge Prospective Memory Test was administered to 125 adults; an excessive alcohol user group (n = 40, a group of smokers who drink very little alcohol (n = 20, a combined user group (the Polydrug group who drink excessively and smoke cigarettes (n = 40 and a non-drinker/low alcohol consumption control group (n = 25. The main findings revealed that the Polydrug users recalled significantly fewer time-based PM tasks than excessive alcohol users p<.001 and smokers p=.013. Polydrug users (mean = 11.47 also remembered significantly fewer event-based PM tasks than excessive alcohol users p<.001 and smokers p = .013. Most interestingly, Polydrug users exhibited significantly greater impaired time-based PM than the combined effect of single excessive alcohol users and smokers p=.033. However, no difference was observed between Polydrug users and the combined effect of single excessive alcohol users and smokers in event-based PM p=.757. These results provide evidence that concurrent use of these two substances has a synergistic effect in terms of deficits upon time-based PM. The observation that excessive drinking and smoking leads to greater impairments in time-based PM may be of paramount importance, given the key role PM plays in everyday independent living.

Violin mode amplitude glitch monitor for the presence of excess noise on the monolithic silica suspensions of GEO 600

Energy Technology Data Exchange (ETDEWEB)

Sorazu, B; Strain, K A; Heng, I S; Kumar, R, E-mail: b.sorazu@physics.gla.ac.u [Department of Physics and Astronomy, University of Glasgow, University Avenue, Glasgow G12 8QQ (United Kingdom)

2010-08-07

Non-Gaussian features of data from gravitational wave detectors are of interest as unpredictable 'glitches' limit the sensitivity of searches for many kinds of signal. We consider events due to non-random excitations of the test masses and their suspension fibres. These events could, for example, be related to acoustic emissions in the fibres due to the presence and propagation of cracks or another type of structural perturbation, and they would generate excess noise above the Gaussian background, which matches the level expected due to thermal noise. We look for excess noise in the fundamental violin modes of the monolithic silica suspension fibres of GEO 600. We describe the algorithm used to monitor the violin mode amplitude for glitches, present our results and consider how these may be applied to advanced detectors. The conclusion of our analysis is that no excess noise above what was considered to be thermal noise was observed for several days of h(t) data analysed at the frequency of the selected violin modes.

Violin mode amplitude glitch monitor for the presence of excess noise on the monolithic silica suspensions of GEO 600

International Nuclear Information System (INIS)

Sorazu, B; Strain, K A; Heng, I S; Kumar, R

2010-01-01

Non-Gaussian features of data from gravitational wave detectors are of interest as unpredictable 'glitches' limit the sensitivity of searches for many kinds of signal. We consider events due to non-random excitations of the test masses and their suspension fibres. These events could, for example, be related to acoustic emissions in the fibres due to the presence and propagation of cracks or another type of structural perturbation, and they would generate excess noise above the Gaussian background, which matches the level expected due to thermal noise. We look for excess noise in the fundamental violin modes of the monolithic silica suspension fibres of GEO 600. We describe the algorithm used to monitor the violin mode amplitude for glitches, present our results and consider how these may be applied to advanced detectors. The conclusion of our analysis is that no excess noise above what was considered to be thermal noise was observed for several days of h(t) data analysed at the frequency of the selected violin modes.

Violin mode amplitude glitch monitor for the presence of excess noise on the monolithic silica suspensions of GEO 600

Science.gov (United States)

Sorazu, B.; Strain, K. A.; Heng, I. S.; Kumar, R.

2010-08-01

Non-Gaussian features of data from gravitational wave detectors are of interest as unpredictable 'glitches' limit the sensitivity of searches for many kinds of signal. We consider events due to non-random excitations of the test masses and their suspension fibres. These events could, for example, be related to acoustic emissions in the fibres due to the presence and propagation of cracks or another type of structural perturbation, and they would generate excess noise above the Gaussian background, which matches the level expected due to thermal noise. We look for excess noise in the fundamental violin modes of the monolithic silica suspension fibres of GEO 600. We describe the algorithm used to monitor the violin mode amplitude for glitches, present our results and consider how these may be applied to advanced detectors. The conclusion of our analysis is that no excess noise above what was considered to be thermal noise was observed for several days of h(t) data analysed at the frequency of the selected violin modes.

SHB1/HY1 Alleviates Excess Boron Stress by Increasing BOR4 Expression Level and Maintaining Boron Homeostasis in Arabidopsis Roots

Directory of Open Access Journals (Sweden)

Qiang Lv

2017-05-01

Full Text Available Boron is an essential mineral nutrient for higher plant growth and development. However, excessive amounts of boron can be toxic. Here, we report on the characterization of an Arabidopsis mutant, shb1 (sensitive to high-level of boron 1, which exhibits hypersensitivity to excessive boron in roots. Positional cloning demonstrated that the shb1 mutant bears a point mutation in a gene encoding a heme oxygenase 1 (HO1 corresponding to the HY1 gene involved in photomorphogenesis. The transcription level of the SHB1/HY1 gene in roots is up-regulated under excessive boron stimulation. Either overexpressing SHB1/HY1 or applying the HO1 inducer hematin reduces boron accumulation in roots and confers high boron tolerance. Furthermore, carbon monoxide and bilirubin, catalytic products of HO1, partially rescue the boron toxicity-induced inhibition of primary root growth in shb1. Additionally, the mRNA level of BOR4, a boron efflux transporter, is reduced in shb1 roots with high levels of boron supplementation, and hematin cannot relieve the boron toxicity-induced root inhibition in bor4 mutants. Taken together, our study reveals that HO1 acts via its catalytic by-products to promote tolerance of excessive boron by up-regulating the transcription of the BOR4 gene and therefore promoting the exclusion of excessive boron in root cells.

19 CFR 10.625 - Refunds of excess customs duties.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Refunds of excess customs duties. 10.625 Section 10.625 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT... and Apparel Goods § 10.625 Refunds of excess customs duties. (a) Applicability. Section 205 of the...

Minimization of Excess Sludge in Activated Sludge Systems

Directory of Open Access Journals (Sweden)

Sayed Ali Reza Momeni

2006-01-01

Full Text Available The disposal of excess sludge from wastewater treatment plant represents a rising challenge in activated sludge processes. Hence, the minimization of excess sludge production was investigated by increasing the dissolved oxygen in aeration basin. Units of the pilot include: Primary sedimentation tank, aeration basin, secondary sedimentation tank, and return sludge tank. Volume of aeration basin is 360 l and influent flow rate is 90 L/h. Influent of pilot is taken from effluent of grit chamber of Isfahan's North Wastewater treatment plant. The experiments were done on different parts of pilot during the 5 month of study. Results show that increase of dissolved oxygen in aeration tank affect on decrease of excess sludge. Increase of dissolved oxygen from 0.5 to 4.5 mg/L resulted in 25% decrease of excess sludge. Variation of dissolved oxygen affect on settleability of sludge too. By increase of dissolved oxygen, SVI decreased and then increased. Value of 1-3 mg/L was the adequate range of dissolved oxygen by settleability of sludge and optimum range was 2-2.5 mg/L. It could be concluded by increasing of dissolved oxygen up to of 3 mg/L, sludge settleability significant decreased.

Plutonium determination in solution with excess hydrofluoric acid

International Nuclear Information System (INIS)

Krtil, J.; Kuvik, V.; Spevackova, V.

1975-01-01

The determination is described of plutonium in solutions in the presence of fluoride ions resulting from the hydrolysis of PuF 6 . The method is based on reduction of Pu(VI) by excess of Fe(II) and on re-titration of Fe(II) with ceric salt. The effect of fluoride ions on plutonium determination was studied. It was found that a 3 mole excess of HF with respect to Pu decreased the results of Pu determination. The interference of fluoride ions was eliminated by a two-fold evaporation of the solution to be titrated with HNO 3 to dryness or by complex formation with boric arid. The amount of 20.50 mg Pu in the presence of a 10 mole excess of fluoride ions (17 mg HF) was determined with an error of +- 0.09 mg ). (author)

Excess Sodium Tetraphenylborate and Intermediates Decomposition Studies

Energy Technology Data Exchange (ETDEWEB)

Barnes, M.J.

1998-12-07

The stability of excess amounts of sodium tetraphenylborate (NaTPB) in the In-Tank Precipitation (ITP) facility depends on a number of variables. Concentration of palladium, initial benzene, and sodium ion as well as temperature provide the best opportunities for controlling the decomposition rate. This study examined the influence of these four variable on the reactivity of palladium-catalyzed sodium tetraphenylborate decomposition. Also, single effects tests investigated the reactivity of simulants with continuous stirring and nitrogen ventilation, with very high benzene concentrations, under washed sodium concentrations, with very high palladium concentrations, and with minimal quantities of excess NaTPB.

Evaluation of drug incorporation into hair segments and nails by enantiomeric analysis following controlled single MDMA intakes.

Science.gov (United States)

Madry, Milena M; Steuer, Andrea E; Hysek, Cédric M; Liechti, Matthias E; Baumgartner, Markus R; Kraemer, Thomas

2016-01-01

Incorporation rates of the enantiomers of 3,4-methylenedioxymethamphetamine (MDMA) and its metabolite 3,4-methylenedioxyamphetamine (MDA) into hair and nails were investigated after controlled administration. Fifteen subjects without MDMA use received two doses of 125 mg of MDMA. Hair, nail scrapings, and nail clippings were collected 9-77 days after the last administration (median 20 days). Hair samples were analyzed in segments of 1- to 2-cm length. After chiral derivatization with N-(2,4-dinitro-5-fluorophenyl)-L-valinamide, MDMA and MDA diastereomers were analyzed by liquid chromatography-tandem mass spectrometry. Highest concentrations in hair segments corresponded to the time of MDMA intake. They ranged from 101 to 3200 pg/mg and 71 to 860 pg/mg for R- and S-MDMA, and from 3.2 to 116 pg/mg and 4.4 to 108 pg/mg for R- and S-MDA, respectively. MDMA and MDA concentrations in nail scrapings and clippings were significantly lower than in hair samples. There was no significant difference between enantiomeric ratios of R/S-MDMA and R/S-MDA in hair and nail samples (medians 2.2-2.4 for MDMA and 0.85-0.95 for MDA). Metabolite ratios of MDA to MDMA were in the same range in hair and nail samples (medians 0.044-0.055). Our study demonstrates that administration of two representative doses of MDMA was detected in the hair segments corresponding to the time of intake based on average hair growth rates. MDMA was detected in all nail samples regardless of time passed after intake. Comparable R/S ratios in hair and nail samples may indicate that incorporation mechanisms into both matrices are comparable.

Enantiomeric quantification of (S)-(+)-methamphetamine in urine by an immunoaffinity column and liquid chromatography-electrospray-mass spectrometry

International Nuclear Information System (INIS)

Lua, Ahai C.; Sutono, Yenny; Chou, T.-Y.

2006-01-01

A method using an immunoaffinity column (IAC) and liquid chromatography-electrospray ionization mass spectrometry (LC/MS) for on-line detecting the presence of MA in the effluent was developed for the quantitative and enantiomeric determination of (S)-(+)-methamphetamine (D-MA) in urine. The IAC was made in our laboratory and utilized in the LC/MS to simultaneously extract and separate enantiomers of MA from urine samples. An aqueous ammonium acetate buffer was used as the mobile phase. Urine samples were spiked with racemic deuterated methamphetamine (MA-d 14 ) as internal standard (IS), filtered through a membrane, and injected into the LC/MS without any further pre-treatment. Protonated molecular ion of MA and MA-d 14 (m/z 150 and 164) were isolated and further fragmented, the respective product ions, m/z 119 and 130, were collected for quantitative determination. This is an improvement of our previous method (A.C. Lua, Tsong-Yung Chou, J. Chromatogr. A 967 (2002) 191). In the previous method, MA was separated with HPLC, the efflux was fractionated and each fraction was either determined with an immunoassay or GC/MS. Monitoring of MA in the efflux is tedious and time consuming. Urine samples spiked with different concentrations of D-MA were measured by this method. A linear relationship exists in the 150-1050 ng/mL range, and the detection limit (defined as signal-to-noise ratio 3) of D-MA was determined to be 18 ng/mL. The linearity of the method for D-MA can be described by the equation (Y = 1.415 x 10 -3 X + 0.034, correlation coefficient: r 2 = 0.999). Within run, accuracy and precision (n = 6, relative error: -7.2 to +4.0% and relative standard deviation: 3.8-9.3%) of the method are fairly good

Enantiomeric quantification of (S)-(+)-methamphetamine in urine by an immunoaffinity column and liquid chromatography-electrospray-mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Lua, Ahai C. [Department of Laboratory Medicine and Biotechnology and Graduate Institute of Medical Biotechnology, Tzu Chi University, 701, Chung Yang Road Section 3, Hualien, 970, Taiwan (China); Sutono, Yenny [Department of Laboratory Medicine and Biotechnology and Graduate Institute of Medical Biotechnology, Tzu Chi University, 701, Chung Yang Road Section 3, Hualien, 970, Taiwan (China); Chou, T.-Y. [Department of Laboratory Medicine and Biotechnology and Graduate Institute of Medical Biotechnology, Tzu Chi University, 701, Chung Yang Road Section 3, Hualien, 970, Taiwan (China)]. E-mail: cty@mail.tcu.edu.tw

2006-08-18

A method using an immunoaffinity column (IAC) and liquid chromatography-electrospray ionization mass spectrometry (LC/MS) for on-line detecting the presence of MA in the effluent was developed for the quantitative and enantiomeric determination of (S)-(+)-methamphetamine (D-MA) in urine. The IAC was made in our laboratory and utilized in the LC/MS to simultaneously extract and separate enantiomers of MA from urine samples. An aqueous ammonium acetate buffer was used as the mobile phase. Urine samples were spiked with racemic deuterated methamphetamine (MA-d{sub 14}) as internal standard (IS), filtered through a membrane, and injected into the LC/MS without any further pre-treatment. Protonated molecular ion of MA and MA-d{sub 14} (m/z 150 and 164) were isolated and further fragmented, the respective product ions, m/z 119 and 130, were collected for quantitative determination. This is an improvement of our previous method (A.C. Lua, Tsong-Yung Chou, J. Chromatogr. A 967 (2002) 191). In the previous method, MA was separated with HPLC, the efflux was fractionated and each fraction was either determined with an immunoassay or GC/MS. Monitoring of MA in the efflux is tedious and time consuming. Urine samples spiked with different concentrations of D-MA were measured by this method. A linear relationship exists in the 150-1050 ng/mL range, and the detection limit (defined as signal-to-noise ratio 3) of D-MA was determined to be 18 ng/mL. The linearity of the method for D-MA can be described by the equation (Y = 1.415 x 10{sup -3} X + 0.034, correlation coefficient: r {sup 2} = 0.999). Within run, accuracy and precision (n = 6, relative error: -7.2 to +4.0% and relative standard deviation: 3.8-9.3%) of the method are fairly good.

A full evaluation for the enantiomeric impacts of lactofen and its metabolites on aquatic macrophyte Lemna minor.

Science.gov (United States)

Wang, Fang; Liu, Donghui; Qu, Han; Chen, Li; Zhou, Zhiqiang; Wang, Peng

2016-09-15

Pesticide pollution of surface water represents a considerable danger for the aquatic plants which play very crucial roles in aquatic system such as oxygen production, nutrient cycling, water quality controlling and sediment stabilization. In this work, the toxic effects of the chiral herbicide lactofen and its three metabolites (desethyl lactofen, acifluorfene and amino acifluorfene) to the aquatic plant Lemna minor (L. minor) on enantiomeric level were evaluated. The influences on growth rate, fresh weight, content of photosynthetic pigment, protein and malondialdehyde (MDA) and the activities of antioxidant defense enzymes (catalase (CAT) and superoxide dismutase (SOD)) were measured after 7 days of exposure. L. minor growth was inhibited in the order of (S)-desethyl lactofen > racemic-desethyl lactofen > (R)-desethyl lactofen > racemic-lactofen > (S)-lactofen > (R)-lactofen > acifluorfene > amino acifluorfene, and the IC50 (7d) values showed desethyl lactofen was the most powerful compound which was about twice as toxic as lactofen. The contents of chlorophylls (Chl) and carotenoids (Car) were significantly reduced by the chemicals, while, the levels of protein, MDA and the activity of CAT and SOD enzymes increased in most cases. The obtained results revealed that lactofen and its metabolites had an undesirable effect on L. minor, in terms of physiological and biochemical aspects. Besides, enantioselective toxicity of lactofen and desethyl lactofen to L. minor was observed. The S-enantiomer of desethyl lactofen was more toxic than the corresponding R-enantiomer. Furthermore, racemic lactofen was more toxic than the individual enantiomers. The side effects of pesticide metabolites and the enantioselectivity should be considered in developing optically pure products and risk assessment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Colour excesses of glabular clusters in the bands U, B, V, I

International Nuclear Information System (INIS)

Kukarkin, B.V.; Kireeva, N.N.; Moskovskij Gosudarstvennyj Univ.

1976-01-01

It is shown that practically all the known methods for the determination of colour excesses of globular clusters on the basis of their integrated colour equivalents are not correct. The observed colour equivalents correlate with colour excesses, so it is difficult to carry out the separation of the observed colour equivalents into the intrinsic colour and the colour excess. Burstein and McDonald's method (7) is the most correct one, but it is also not free from systematic errors caused by the presence of a correlation between the terms of the equations they used. The blameless method for the determination of interstellar reddening on the basis of the measures of colour excesses of field stars (1) can be used only for extremely limited number of clusters today. The author suggests a method for separating the observed colour equivalents into intrinsic colours and colour excesses which is based on the selection of clusters with the smallest excesses, too small to cause any noticeable errors. The values of intrinsic colour equivalents thus obtained strongly correlate with integrated spectral types and are characterized by the mean error as small as +-0.018. The colour excesses calculated on these grounds made it possible to determine reliable ratios of colour excesses in the bands U, B, V, I. These ratio were used in order to calculate the colour excesses for all the clusters with measured colour equivalents and known integrated spectra. On the basis of the analysis of all the available material the finally adopted values of colour excesses, intrinisic colour equivalents, and integrated spectral types for 68 globular clusters were obtained

Insomnia, excessive sleepiness, excessive fatigue, anxiety, depression and shift work disorder in nurses having less than 11 hours in-between shifts.

Directory of Open Access Journals (Sweden)

Maria Fagerbakke Eldevik

Full Text Available STUDY OBJECTIVE: To assess if less than 11 hours off work between work shifts (quick returns was related to insomnia, sleepiness, fatigue, anxiety, depression and shift work disorder among nurses. METHODS: A questionnaire including established instruments measuring insomnia (Bergen Insomnia Scale, sleepiness (Epworth Sleepiness Scale, fatigue (Fatigue Questionnaire, anxiety/depression (Hospital Anxiety and Depression Scale and shift work disorder was administered. Among the 1990 Norwegian nurses who participated in the study; 264 nurses had no quick returns, 724 had 1-30 quick returns and 892 had more than 30 quick returns during the past year. 110 nurses did not report the number of quick returns during the past year. The prevalence of insomnia, excessive sleepiness, excessive fatigue, anxiety, depression and shift work disorder was calculated within the three groups of nurses. Crude and adjusted logistic regression analyses were performed to assess the relation between quick returns and such complaints. RESULTS: We found a significant positive association between quick returns and insomnia, excessive sleepiness, excessive fatigue and shift work disorder. Anxiety and depression were not related to working quick returns. CONCLUSIONS: There is a health hazard associated with quick returns. Further research should aim to investigate if workplace strategies aimed at reducing the number of quick returns may reduce complaints among workers.

Insomnia, excessive sleepiness, excessive fatigue, anxiety, depression and shift work disorder in nurses having less than 11 hours in-between shifts.

Science.gov (United States)

Eldevik, Maria Fagerbakke; Flo, Elisabeth; Moen, Bente Elisabeth; Pallesen, Ståle; Bjorvatn, Bjørn

2013-01-01

To assess if less than 11 hours off work between work shifts (quick returns) was related to insomnia, sleepiness, fatigue, anxiety, depression and shift work disorder among nurses. A questionnaire including established instruments measuring insomnia (Bergen Insomnia Scale), sleepiness (Epworth Sleepiness Scale), fatigue (Fatigue Questionnaire), anxiety/depression (Hospital Anxiety and Depression Scale) and shift work disorder was administered. Among the 1990 Norwegian nurses who participated in the study; 264 nurses had no quick returns, 724 had 1-30 quick returns and 892 had more than 30 quick returns during the past year. 110 nurses did not report the number of quick returns during the past year. The prevalence of insomnia, excessive sleepiness, excessive fatigue, anxiety, depression and shift work disorder was calculated within the three groups of nurses. Crude and adjusted logistic regression analyses were performed to assess the relation between quick returns and such complaints. We found a significant positive association between quick returns and insomnia, excessive sleepiness, excessive fatigue and shift work disorder. Anxiety and depression were not related to working quick returns. There is a health hazard associated with quick returns. Further research should aim to investigate if workplace strategies aimed at reducing the number of quick returns may reduce complaints among workers.

Tracking atmospheric boundary layer dynamics with water vapor D-excess observations

KAUST Repository

Parkes, Stephen

2015-04-01

Stable isotope water vapor observations present a history of hydrological processes that have impacted on an air mass. Consequently, there is scope to improve our knowledge of how different processes impact on humidity budgets by determining the isotopic end members of these processes and combining them with in-situ water vapor measurements. These in-situ datasets are still rare and cover a limited geographical expanse, so expanding the available data can improve our ability to define isotopic end members and knowledge about atmospheric humidity dynamics. Using data collected from an intensive field campaign across a semi-arid grassland site in eastern Australia, we combine multiple methods including in-situ stable isotope observations to study humidity dynamics associated with the growth and decay of the atmospheric boundary layer and the stable nocturnal boundary layer. The deuterium-excess (D-excess) in water vapor is traditionally thought to reflect the sea surface temperature and relative humidity at the point of evaporation over the oceans. However, a number of recent studies suggest that land-atmosphere interactions are also important in setting the D-excess of water vapor. These studies have shown a highly robust diurnal cycle for the D-excess over a range of sites that could be exploited to better understand variations in atmospheric humidity associated with boundary layer dynamics. In this study we use surface radon concentrations as a tracer of surface layer dynamics and combine these with the D-excess observations. The radon concentrations showed an overall trend that was inversely proportional to the D-excess, with early morning entrainment of air from the residual layer of the previous day both diluting the radon concentration and increasing the D-excess, followed by accumulation of radon at the surface and a decrease in the D-excess as the stable nocturnal layer developed in the late afternoon and early evening. The stable nocturnal boundary layer

46 CFR 35.25-15 - Carrying of excess steam-TB/ALL.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Carrying of excess steam-TB/ALL. 35.25-15 Section 35.25... § 35.25-15 Carrying of excess steam—TB/ALL. It shall be the duty of the chief engineer of any tank vessel to see that a steam pressure is not carried in excess of that allowed by the certificate of...

Excessive crying: behavioral and emotional regulation disorder in infancy

Directory of Open Access Journals (Sweden)

Joon Sik Kim

2011-06-01

Full Text Available In the pediatric literature, excessive crying has been reported solely in association with 3-month colic and is described, if at all, as unexplained crying and fussing during the first 3 months of life. The bouts of crying are generally thought to be triggered by abdominal colic (over-inflation of the still immature gastrointestinal tract, and treatment is prescribed accordingly. According to this line of reasoning, excessive crying is harmless and resolves by the end of the third month without long-term consequences. However, there is evidence that it may cause tremendous distress in the mother&#8211;infant relationship, and can lead to disorders of behavioral and emotional regulation at the toddler stage (such as sleep and feeding disorders, chronic fussiness, excessive clinginess, and temper tantrums. Early treatment of excessive crying focuses on parent&#8211;infant communication, and parent-infant interaction in the context of soothing and settling the infant to sleep is a promising approach that may prevent later behavioral and emotional disorders in infancy.

Metallicity and ultraviolet excesses of late main sequence stars

International Nuclear Information System (INIS)

Suchkov, A.A.; Marsakov, V.A.; Shevelev, Yu.G.

1987-01-01

The comparison of the characteristics of ultraviolet (UV) excesses δ(U-B) and metallicity [Fe/H] distributions of F, G, and K dwarfs reveals a number of discrepancies. It is shown that they can be eliminated if we assume that UV excesses of K and late G dwarfs, and [Fe/H] values from detailed analysis for F dwarfs are underestimated. Such an assumption enables to account for low values of for F, K and late G dwarfs, and for the difference of the free terms in the metallicity - UV-excess relation for these stars as compared to early G dwarfs. In this case the F5-F9 dwarfs turn out to be more metal-rich (by 0.1 in [Fe/H]) than G and K dwarfs, and the metallicity of the Hyades cluster turns out to be larger than the solar one, [Fe/H] Hyades =+0.1. The ''conditional'' metallicity - UV-excess calibrations are obtained for four groups of main-sequence stars: F5-F9, G0-G4, G5-G9, K0-K5

Country Fundamentals and Currency Excess Returns

Directory of Open Access Journals (Sweden)

Daehwan Kim

2014-06-01

Full Text Available We examine whether country fundamentals help explain the cross-section of currency excess returns. For this purpose, we consider fundamental variables such as default risk, foreign exchange rate regime, capital control as well as interest rate in the multi-factor model framework. Our empirical results show that fundamental factors explain a large part of the cross-section of currency excess returns. The zero-intercept restriction of the factor model is not rejected for most currencies. They also reveal that our factor model with country fundamentals performs better than a factor model with usual investment-style factors. Our main empirical results are based on 2001-2010 balanced panel data of 19 major currencies. This paper may fill the gap between country fundamentals and practitioners' strategies on currency investment.

The excess radio background and fast radio transients

International Nuclear Information System (INIS)

Kehayias, John; Kephart, Thomas W.; Weiler, Thomas J.

2015-01-01

In the last few years ARCADE 2, combined with older experiments, has detected an additional radio background, measured as a temperature and ranging in frequency from 22 MHz to 10 GHz, not accounted for by known radio sources and the cosmic microwave background. One type of source which has not been considered in the radio background is that of fast transients (those with event times much less than the observing time). We present a simple estimate, and a more detailed calculation, for the contribution of radio transients to the diffuse background. As a timely example, we estimate the contribution from the recently-discovered fast radio bursts (FRBs). Although their contribution is likely 6 or 7 orders of magnitude too small (though there are large uncertainties in FRB parameters) to account for the ARCADE 2 excess, our development is general and so can be applied to any fast transient sources, discovered or yet to be discovered. We estimate parameter values necessary for transient sources to noticeably contribute to the radio background

Explanation for excessive DNA single-strand breaks and endogenous repair foci in pluripotent mouse embryonic stem cells.

Science.gov (United States)

Banáth, J P; Bañuelos, C A; Klokov, D; MacPhail, S M; Lansdorp, P M; Olive, P L

2009-05-01

Pluripotent mouse embryonic stem cells (mES cells) exhibit approximately 100 large gammaH2AX repair foci in the absence of measurable numbers of DNA double-strand breaks. Many of these cells also show excessive numbers of DNA single-strand breaks (>10,000 per cell) when analyzed using the alkaline comet assay. To understand the reasons for these unexpected observations, various methods for detecting DNA strand breaks were applied to wild-type mES cells and to mES cells lacking H2AX, ATM, or DNA-PKcs. H2AX phosphorylation and expression of other repair complexes were measured using flow and image analysis of antibody-stained cells. Results indicate that high numbers of endogenous gammaH2AX foci and single-strand breaks in pluripotent mES cells do not require ATM or DNA-PK kinase activity and appear to be associated with global chromatin decondensation rather than pre-existing DNA damage. This will limit applications of gammaH2AX foci analysis in mES cells to relatively high levels of initial or residual DNA damage. Excessive numbers of single-strand breaks in the alkaline comet assay can be explained by the vulnerability of replicating chromatin in mES cells to osmotic shock. This suggests that caution is needed in interpreting results with the alkaline comet assay when applied to certain cell types or after treatment with agents that make chromatin vulnerable to osmotic changes. Differentiation of mES cells caused a reduction in histone acetylation, gammaH2AX foci intensity, and DNA single-strand breakage, providing a link between chromatin structural organization, excessive gammaH2AX foci, and sensitivity of replicating mES cell chromatin to osmotic shock.

Excess lithium storage in LiFePO4-Carbon interface by ball-milling

Science.gov (United States)

Guo, Hua; Song, Xiaohe; Zheng, Jiaxin; Pan, Feng

2016-07-01

As one of the most popular cathode materials for high power lithium ion batteries (LIBs) of the electrical-vehicle (EV), lithium iron phosphate (LiFePO4 (LFP)) is limited to its relatively lower theoretical specific capacity of 170mAh g-1. To break the limits and further improve the capacity of LFP is promising but challenging. In this study, the ball-milling method is applied to the mixture of LFP and carbon, and the effective capacity larger than the theoretical one by 30mAh g-1 is achieved. It is demonstrated that ball-milling leads to the LFP-Carbon interface to store the excess Li-ions.

Management of excessive movable tissue: a modified impression technique.

Science.gov (United States)

Shum, Michael H C; Pow, Edmond H N

2014-08-01

Excessive movable tissue is a challenge in complete denture prosthetics. A modified impression technique is presented with polyvinyl siloxane impression material and a custom tray with relief areas and perforations in the area of the excessive movable tissue. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Investigation of excess thyroid cancer incidence in Los Alamos County

Energy Technology Data Exchange (ETDEWEB)

Athas, W.F.

1996-04-01

Los Alamos County (LAC) is home to the Los Alamos National Laboratory, a U.S. Department of Energy (DOE) nuclear research and design facility. In 1991, the DOE funded the New Mexico Department of Health to conduct a review of cancer incidence rates in LAC in response to citizen concerns over what was perceived as a large excess of brain tumors and a possible relationship to radiological contaminants from the Laboratory. The study found no unusual or alarming pattern in the incidence of brain cancer, however, a fourfold excess of thyroid cancer was observed during the late-1980`s. A rapid review of the medical records for cases diagnosed between 1986 and 1990 failed to demonstrate that the thyroid cancer excess had resulted from enhanced detection. Surveillance activities subsequently undertaken to monitor the trend revealed that the excess persisted into 1993. A feasibility assessment of further studies was made, and ultimately, an investigation was conducted to document the epidemiologic characteristics of the excess in detail and to explore possible causes through a case-series records review. Findings from the investigation are the subject of this report.

Investigation of excess thyroid cancer incidence in Los Alamos County

International Nuclear Information System (INIS)

Athas, W.F.

1996-04-01

Los Alamos County (LAC) is home to the Los Alamos National Laboratory, a U.S. Department of Energy (DOE) nuclear research and design facility. In 1991, the DOE funded the New Mexico Department of Health to conduct a review of cancer incidence rates in LAC in response to citizen concerns over what was perceived as a large excess of brain tumors and a possible relationship to radiological contaminants from the Laboratory. The study found no unusual or alarming pattern in the incidence of brain cancer, however, a fourfold excess of thyroid cancer was observed during the late-1980's. A rapid review of the medical records for cases diagnosed between 1986 and 1990 failed to demonstrate that the thyroid cancer excess had resulted from enhanced detection. Surveillance activities subsequently undertaken to monitor the trend revealed that the excess persisted into 1993. A feasibility assessment of further studies was made, and ultimately, an investigation was conducted to document the epidemiologic characteristics of the excess in detail and to explore possible causes through a case-series records review. Findings from the investigation are the subject of this report

Thermodynamic study of (heptane + amine) mixtures. II. Excess and partial molar volumes at 298.15 K

International Nuclear Information System (INIS)

Lepori, Luciano; Gianni, Paolo; Spanedda, Andrea; Matteoli, Enrico

2011-01-01

Research highlights: → Excess and partial molar volumes of primary (amines + heptane) mixtures. → Excess volumes are positive for small size amines and decrease as the size increases. → Group contributions to predict the partial molar volumes of amines in heptane. → The void volume is larger for branched than for linear amines in heptane. - Abstract: Excess molar volumes V E at 298.15 K were determined by means of a vibrating tube densimeter for binary mixtures of heptane + primary n-alkyl (C 3 to C 10 ) and branched amines (iso-propyl-, iso-, sec-, and tert-butyl-, iso-, tert-pentyl-, and pentan-3-amine) in the whole composition range. The apparent molar volumes of solid dodecyl- and tetradecylamine in heptane dilute solution were also determined. The V E values were found positive for mixtures involving C 3 to C 8 linear amines, with V E decreasing with chain lengthening. Heptane + nonyl and decylamine showed s-shaped, markedly asymmetric, curves. Mixtures with branched C 3 to C 5 amines displayed positive V E 's larger than those observed in the mixtures of the corresponding linear isomers. Partial molar volumes V o at infinite dilution in heptane were evaluated for the examined amines and compared with those of alkanes and alkanols taken from the literature. An additivity scheme, based on the intrinsic volume approach, was applied to estimate group (CH 3 , CH 2 , CH, C, NH 2 , and OH) contributions to V o . The effect of branching on V o and the limiting slope of the apparent excess molar volumes were evaluated and discussed in terms of solute-solvent and solute-solute interactions.

Search for bright stars with infrared excess

Energy Technology Data Exchange (ETDEWEB)

Raharto, Moedji, E-mail: moedji@as.itb.ac.id [Astronomy Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia)

2014-03-24

Bright stars, stars with visual magnitude smaller than 6.5, can be studied using small telescope. In general, if stars are assumed as black body radiator, then the color in infrared (IR) region is usually equal to zero. Infrared data from IRAS observations at 12 and 25μm (micron) with good flux quality are used to search for bright stars (from Bright Stars Catalogues) with infrared excess. In magnitude scale, stars with IR excess is defined as stars with IR color m{sub 12}−m{sub 25}>0; where m{sub 12}−m{sub 25} = −2.5log(F{sub 12}/F{sub 25})+1.56, where F{sub 12} and F{sub 25} are flux density in Jansky at 12 and 25μm, respectively. Stars with similar spectral type are expected to have similar color. The existence of infrared excess in the same spectral type indicates the existence of circum-stellar dust, the origin of which is probably due to the remnant of pre main-sequence evolution during star formation or post AGB evolution or due to physical process such as the rotation of those stars.

Excess electron transport in cryoobjects

International Nuclear Information System (INIS)

Eshchenko, D.G.; Storchak, V.G.; Brewer, J.H.; Cottrell, S.P.; Cox, S.F.J.

2003-01-01

Experimental results on excess electron transport in solid and liquid phases of Ne, Ar, and solid N 2 -Ar mixture are presented and compared with those for He. Muon spin relaxation technique in frequently switching electric fields was used to study the phenomenon of delayed muonium formation: excess electrons liberated in the μ + ionization track converge upon the positive muons and form Mu (μ + e - ) atoms. This process is shown to be crucially dependent upon the electron's interaction with its environment (i.e., whether it occupies the conduction band or becomes localized in a bubble of tens of angstroms in radius) and upon its mobility in these states. The characteristic lengths involved are 10 -6 -10 -4 cm, the characteristic times range from nanoseconds to tens microseconds. Such a microscopic length scale sometimes enables the electron spend its entire free lifetime in a state which may not be detected by conventional macroscopic techniques. The electron transport processes are compared in: liquid and solid helium (where electron is localized in buble); liquid and solid neon (where electrons are delocalized in solid and the coexistence of localized and delocalized electrons states was found in liquid recently); liquid and solid argon (where electrons are delocalized in both phases); orientational glass systems (solid N 2 -Ar mixtures), where our results suggest that electrons are localized in orientational glass. This scaling from light to heavy rare gases enables us to reveal new features of excess electron localization on microscopic scale. Analysis of the experimental data makes it possible to formulate the following tendency of the muon end-of-track structure in condensed rare gases. The muon-self track interaction changes from the isolated pair (muon plus the nearest track electron) in helium to multi-pair (muon in the vicinity of tens track electrons and positive ions) in argon

Analysis of excess reactivity of JOYO MK-III performance test core

International Nuclear Information System (INIS)

Maeda, Shigetaka; Yokoyama, Kenji

2003-10-01

JOYO is currently being upgraded to the high performance irradiation bed JOYO MK-III core'. The MK-III core is divided into two fuel regions with different plutonium contents. To obtain a higher neutron flux, the active core height was reduced from 55 cm to 50 cm. The reflector subassemblies were replaced by shielding subassemblies in the outer two rows. Twenty of the MK-III outer core fuel subassemblies in the performance test core were partially burned in the transition core. Four irradiation test rigs, which do not contain any fuel material, were loaded in the center of the performance test core. In order to evaluate the excess reactivity of MK-III performance test core accurately, we evaluated it by applying not only the JOYO MK-II core management code system MAGI, but also the MK-III core management code system HESTIA, the JUPITER standard analysis method and the Monte Carlo method with JFS-3-J3.2R content set. The excess reactivity evaluations obtained by the JUPITER standard analysis method were corrected to results based on transport theory with zero mesh-size in space and angle. A bias factor based on the MK-II 35th core, which sensitivity was similar to MK-III performance test core's, was also applied, except in the case where an adjusted nuclear cross-section library was used. Exact three-dimensional, pin-by-pin geometry and continuous-energy cross sections were used in the Monte Carlo calculation. The estimated error components associated with cross-sections, methods correction factors and the bias factor were combined based on Takeda's theory. Those independently calculated values agree well and range from 2.8 to 3.4%Δk/kk'. The calculation result of the MK-III core management code system HESTLA was 3.13% Δk/kk'. The estimated errors for bias method range from 0.1 to 0.2%Δk/kk'. The error in the case using adjusted cross-section was 0.3%Δk/kk'. (author)

Transition metal complexes of oxazolinylboranes and cyclopentadienyl-bis(oxazolinyl)borates: Catalysts for asymmetric olefin hydroamination and acceptorless alcohol decarbonylation

Energy Technology Data Exchange (ETDEWEB)

Manna, Kuntal [Ames Lab., Ames, IA (United States)

2012-12-17

The research presented and discussed in this dissertation involves the synthesis of transition metal complexes of oxazolinylboranes and cyclopentadienyl-bis(oxazolinyl)borates, and their application in catalytic enantioselective olefin hydroamination and acceptorless alcohol decarbonylation. Neutral oxazolinylboranes are excellent synthetic intermediates for preparing new borate ligands and also developing organometallic complexes. Achiral and optically active bis(oxazolinyl)phenylboranes are synthesized by reaction of 2-lithio-2-oxazolide and 0.50 equiv of dichlorophenylborane. These bis(oxazolinyl)phenylboranes are oligomeric species in solid state resulting from the coordination of an oxazoline to the boron center of another borane monomer. The treatment of chiral bis(oxazolinyl)phenylboranes with sodium cyclopentadienide provide optically active cyclopentadienyl-bis(oxazolinyl)borates H[PhB(C₅H₅)(Ox^R)₂] [Ox^R = Ox^4S-iPr,Me2, Ox^4R-iPr,Me2, Ox^4S-tBu]. These optically active proligands react with an equivalent of M(NMe₂)₄ (M = Ti, Zr, Hf) to afford corresponding cyclopentadienyl-bis(oxazolinyl)borato group 4 complexes {PhB(C₅H₄)(Ox^R)₂}M(NMe₂)₂ in high yields. These group 4 compounds catalyze cyclization of aminoalkenes at room temperature or below, providing pyrrolidine, piperidine, and azepane with enantiomeric excesses up to 99%. Our mechanistic investigations suggest a non-insertive mechanism involving concerted C-N/C-H bond formation in the turnover limiting step of the catalytic cycle. Among cyclopentadienyl-bis(oxazolinyl)borato group 4 catalysts, the zirconium complex {PhB(C₅H₄)(Ox4^S-iPr,Me2)₂}Zr(NMe₂)₂ ({S-2}Zr(NMe₂)₂) displays highest activity and enantioselectivity. Interestingly, _S-2

VALIDITY OF EXCESS ENTROPY PRODUCTION CRITERION OF THERMODYNAMIC STABILITY FOR NONEQUILIBRIUM STEADY STATES

Institute of Scientific and Technical Information of China (English)

吴金平

1991-01-01

The relation between the excess entropy production criterion of thermodynamic stabilityfor nonequilibrium states and kinetic linear stability principle is discussed. It is shown thatthe condition required by the excess entropy production criterion generally is sufficient, butnot necessary to judge the system stability. The condition required by the excess entropyproduction criterion is stronger than that of the linear stability principle. Only when theproduct matrix between the linearized matrix of kinetic equations and matrix of quadraticform of second-order excess entropy is symmetric, is the condition required by the excessentropy production criterion that the steady steate is asymptotically stable (δ_xP>0) necessaryand sufficient. The counterexample given by Fox to prove that the excess entropy, (δ~2S)ss,is not a Liapunov function is incorrect. Contradictory to his conclusion, the counterexampleis just a positive one that proves that the excess entropy is a Liapunov function. Moreover,the excess entropy production criterion is not limited by symmetric conditions of the linear-ized matrix of kinetic equations. The excess entropy around nonequilibrium steady states,(δ~2S)ss, is a Liapunov function of thermodynamic system.

Excess Molar Volumes and Excess Molar Enthalpies in Binary Systems N-alkyl-triethylammonium bis(trifluoromethylsulfonyl)imide + Methanol

Czech Academy of Sciences Publication Activity Database

Machanová, Karolina; Troncoso, J.; Jacquemin, J.; Bendová, Magdalena

2014-01-01

Roč. 363, FEB 15 (2014), s. 156-166 ISSN 0378-3812 Institutional support: RVO:67985858 Keywords : ionic liquids * excess properties * binary mixtures Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.200, year: 2014

Internet addiction or excessive internet use.

Science.gov (United States)

Weinstein, Aviv; Lejoyeux, Michel

2010-09-01

Problematic Internet addiction or excessive Internet use is characterized by excessive or poorly controlled preoccupations, urges, or behaviors regarding computer use and Internet access that lead to impairment or distress. Currently, there is no recognition of internet addiction within the spectrum of addictive disorders and, therefore, no corresponding diagnosis. It has, however, been proposed for inclusion in the next version of the Diagnostic and Statistical Manual of Mental Disorder (DSM). To review the literature on Internet addiction over the topics of diagnosis, phenomenology, epidemiology, and treatment. Review of published literature between 2000-2009 in Medline and PubMed using the term "internet addiction. Surveys in the United States and Europe have indicated prevalence rate between 1.5% and 8.2%, although the diagnostic criteria and assessment questionnaires used for diagnosis vary between countries. Cross-sectional studies on samples of patients report high comorbidity of Internet addiction with psychiatric disorders, especially affective disorders (including depression), anxiety disorders (generalized anxiety disorder, social anxiety disorder), and attention deficit hyperactivity disorder (ADHD). Several factors are predictive of problematic Internet use, including personality traits, parenting and familial factors, alcohol use, and social anxiety. Although Internet-addicted individuals have difficulty suppressing their excessive online behaviors in real life, little is known about the patho-physiological and cognitive mechanisms responsible for Internet addiction. Due to the lack of methodologically adequate research, it is currently impossible to recommend any evidence-based treatment of Internet addiction.

Deuterium Excess of Waters in Slovenia. Preliminary Results

Energy Technology Data Exchange (ETDEWEB)

Brencic, M.; Torkar, A. [Faculty of Natural Sciences and Engineering, University of Ljubljana, Ljubljana (Slovenia); Vreca, P. [Jozef Stefan Institut, Department of Environmental Sciences, Ljubljana (Slovenia)

2013-07-15

In climatic and hydrological studies, deuterium excess has proven to be a useful parameter; therefore this parameter has been investigated in the waters of slovenia - positioned in central europe. All the data were acquired from publicly available data sources (e.g. journals, databases). Data were collected for four different parts of the water cycle: precipitation, surface water, groundwater and water in the unsaturated zone. For precipitation the value for deuterium excess ranges between -19.9 per mille and 28.8 per mille with the median at 10.1 per mille. Surface water has the minimum at 2.9 per mille, the maximum at 22.4 per mille and the median at 13.2 per mille. Values for groundwater vary between -17.7 per mille and 34.9 per mille with the median at 11.8 per mille. Median for deuterium excess for the unsaturated zone is 15.1 per mille and the values are between -2.8 per mille and 17.6 per mille. (author)

Same-sign dilepton excesses and vector-like quarks

Energy Technology Data Exchange (ETDEWEB)

Chen, Chuan-Ren [Department of Physics, National Taiwan Normal University,Ting-Chou Road, Taipei 116, Taiwan (China); Cheng, Hsin-Chia [Department of Physics, University of California,One Shields Avenue, Davis, CA 95616 (United States); Low, Ian [Department of Physics and Astronomy, Northwestern University,Sheridan Road, Evanston, IL 60208 (United States); High Energy Physics Division, Argonne National Laboratory,S. Cass Avenue, Argonne, IL 60439 (United States)

2016-03-15

Multiple analyses from ATLAS and CMS collaborations, including searches for ttH production, supersymmetric particles and vector-like quarks, observed excesses in the same-sign dilepton channel containing b-jets and missing transverse energy in the LHC Run 1 data. In the context of little Higgs theories with T parity, we explain these excesses using vector-like T-odd quarks decaying into a top quark, a W boson and the lightest T-odd particle (LTP). For heavy vector-like quarks, decay topologies containing the LTP have not been searched for at the LHC. The bounds on the masses of the T-odd quarks can be estimated in a simplified model approach by adapting the search limits for top/bottom squarks in supersymmetry. Assuming a realistic decay branching fraction, a benchmark with a 750 GeV T-odd b{sup ′} quark is proposed. We also comment on the possibility to fit excesses in different analyses in a common framework.

Parity violation and parity conservation in unstirred crystallization: Effect of first crystals

Energy Technology Data Exchange (ETDEWEB)

Szurgot, M. [Center of Mathematics and Physics, Technical University of Lodz (Poland)

2012-02-15

Statistics of nucleation of chiral forms was studied to establish the effect of the number of first crystals and their handedness on distributions of enantiomers. Various bimodal, trimodal and unimodal distributions are obtained in unstirred crystallization, depending on the number of initial crystals and growth conditions. The binomial distribution satisfactorily describes experimental distributions of enantiomeric excess and may be used to predict distributions and probabilities of nucleation of enantiomers. The first nucleated crystals determine the handedness of secondary crystals, and number of initial crystals governs statistics of chiral nucleation. According to the binomial distribution if single crystals nucleate as the first, the bimodal distributions result with D and L peaks. If LD, LL, and DD pairs are nucleated as first, trimodal distributions with D, R, and L peaks are created, and if groups of crystals of various handedness nucleate as the first the unimodal distributions of enantiomeric excess with racemate R peaks are formed. Chiral nucleation experiments on sodium bromate were the basis for the theoretical considerations and verifications of predictions resulting from binomial distributions on probabilities of the creation of L and D crystals, and racemates, and the presence of D, L, and R peaks in the distributions. Growth conditions affect the number of the first crystals and effectiveness of cloning, and as a result, the distributions of enantiomers. Formation of pure enantiomers and/or racemates proves that the conservation of chiral symmetry, and the breakage of chiral symmetry can occur in unstirred crystallization. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Atomic absorption photometry of excess Zn in ZnO

Energy Technology Data Exchange (ETDEWEB)

Lott, K.; Shinkarenko, S.; Tuern, L. [Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Kirsanova, T.; Grebennik, A.; Vishnjakov, A. [Department of Physical Chemistry, D. Mendelejev University of Chemical Technology of Russia, Miusskaya Sq. 9, 125047 Moscow (Russian Federation)

2005-02-01

Zn excess in ZnO is built up automatically at high temperatures. Excess Zn in hydrothermally grown ZnO single crystals were investigated by the atomic absorption photometry (AAP) method. To determine the excess zinc in ZnO samples, the AAP of zinc vapour was used in the conditions of solid-vapour equilibrium. Zn AAP allowed to eliminate excess Zn connected differentially in ZnO samples. To fix Zn non-stoichiometry, all the ZnO samples tested were previously heat treated at temperature interval from 850 to 900 C and at fixed Zn vapour pressures from 0.1 to 0.9 of saturated zinc vapour pressure at given treatment temperature. The analysis of temperature dependence of zinc vapour pressure indicated that the impurity metals take active role in the determination of non-stoichiometric zinc. The impurities Mn, Fe, Co, Ni and Cu form oxides which will reduce during annealing in Zn vapor up to metals form. During AAP measurement in optical cuvette, these metals react with ZnO and give additional Zn vapor pressure. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Excess mortality in mothers of patients with polycystic ovary syndrome

NARCIS (Netherlands)

Louwers, Y. V.; Roest-Schalken, M. E.; Kleefstra, N.; van Lennep, J. Roeters; van den Berg, M.; Fauser, B. C. J. M.; Bilo, H. J. G.; Sijbrands, E. J. G.; Laven, J. S. E.

STUDY QUESTION: Do diabetic parents of patients with polycystic ovary syndrome (PCOS) encounter excess mortality compared with the mortality of men and women with type 2 diabetes, recruited without selection for PCOS? SUMMARY ANSWER: Type 2 diabetes among mothers of PCOS patients results in excess

What Can Rational Investors Do About Excessive Volatility and Sentiment Fluctuations?

OpenAIRE

Bernard Dumas; Alexander Kurshev; Raman Uppal

2005-01-01

Our objective is to understand the trading strategy that would allow an investor to take advantage of 'excessive' stock price volatility and 'sentiment' fluctuations. We construct a general equilibrium model of sentiment. In it, there are two classes of agents and stock prices are excessively volatile because one class is overconfident about a public signal. As a result, this class of irrational agents changes its expectations too often, sometimes being excessively optimistic, sometimes being...

Enantiomeric separation of type I and type II pyrethroid insecticides with different chiral stationary phases by reversed-phase high-performance liquid chromatography.

Science.gov (United States)

Zhang, Ping; Yu, Qian; He, Xiulong; Qian, Kun; Xiao, Wei; Xu, Zhifeng; Li, Tian; He, Lin

2018-04-01

The enantiomeric separation of type I (bifenthrin, BF) and type II (lambda-cyhalothrin, LCT) pyrethroid insecticides on Lux Cellulose-1, Lux Cellulose-3, and Chiralpak IC chiral columns was investigated by reversed-phase high-performance liquid chromatography. Methanol/water or acetonitrile/water was used as mobile phase at a flow rate of 0.8 mL/min. The effects of chiral stationary phase, mobile phase composition, column temperature, and thermodynamic parameters on enantiomer separation were carefully studied. Bifenthrin got a partial separation on Lux Cellulose-1 column and baseline separation on Lux Cellulose-3 column, while LCT enantiomers could be completely separated on both Lux Cellulose-1 and Lux Cellulose-3 columns. Chiralpak IC provided no separation ability for both BF and LCT. Retention factor (k) and selectivity factor (α) decreased with the column temperature increasing from 10°C to 40°C for both BF and LCT enantiomers. Thermodynamic parameters including ∆H and ∆S were also calculated, and the maximum R s were not always obtained at lowest temperature. Furthermore, the quantitative analysis methods for BF and LCT enantiomers in soil and water were also established. Such results provide a new approach for pyrethroid separation under reversed-phase condition and contribute to environmental risk assessment of pyrethroids at enantiomer level. © 2017 Wiley Periodicals, Inc.

Excessive crying in infants

Directory of Open Access Journals (Sweden)

Ricardo Halpern

2016-05-01

Conclusion: Excessive crying in the early months is a prevalent symptom; the pediatrician's attention is necessary to understand and adequately manage the problem and offer support to exhausted parents. The prescription of drugs of questionable action and with potential side effects is not a recommended treatment, except in extreme situations. The effectiveness of dietary treatments and use of probiotics still require confirmation. There is incomplete evidence regarding alternative treatments such as manipulation techniques, acupuncture, and use of the herbal supplements and behavioral interventions.

The effect of excessive iodine diet on thyroid function

International Nuclear Information System (INIS)

Wang Yuhua; Li Yaming

2009-01-01

The modify of the thyroid cell structure can be induced by excessive iodine diet. Then the disordered thyroid function can result in a number of thyroid disease. The radionucline thyroid imaging play an important role in diagnoses of thyroid. Amplify on the effect of excessive diet on thyroid function will be worthy instructing what preparation should do before doing the thyroid nuclide imaging. (authors)

Is the excessive use of microblogs an Internet addiction? Developing a scale for assessing the excessive use of microblogs in Chinese college students.

Directory of Open Access Journals (Sweden)

Juan Hou

Full Text Available More and more college students are using microblogs, with some excessive users demonstrating addiction-like symptoms. However, there is currently no published scale available for use in assessing excessive use of these microblogs, a significant impediment to advancing this area of research. We collected data from 3,047 college students in China and developed a Microblog Excessive Use Scale (MEUS for Chinese college students, comparing it with criteria used for assessing Internet addiction. Our diagnostic scale featured three factors, two of which--"withdrawal and health problem" and "time management and performance"--are already included in Internet addiction assessment scales. The third factor, "social comfort," does not appear in Internet addiction assessment scales. Our study found that females have significantly higher MEUS scores than males, and that total MEUS scores positively correlated with scores from "self-disclosure" and "real social interaction" scales. These findings differ from results obtained in previous investigations into Internet addiction. Our results indicate that some characteristics of the excessive use of microblogs are different to those of Internet addiction, suggesting that microblog overuse may not correspond exactly to the state of Internet addiction.

Enrichment of Non-Terrestrial L-Proteinogenic Amino Acids by Aqueous Alteration on the Tagish Lake Meteorite Parent Body

Science.gov (United States)

Glavin, Daniel P.; Elsila, Jamie E.; Burton, Aaron S.; Callahan, Michael P.; Dworkin, Jason P.; Herd, Christopher D. K.

2012-01-01

The distribution and isotopic and enantiomeric compositions of amino acids found in three distinct fragments of the Tagish Lake C2-type carbonaceous chondrite were investigated via liquid chromatography fluorescence detection time-of-flight mass spectrometry and gas chromatography isotope ratio mass spectrometry. Large L-enantiomeric excesses (L(sub ee) approx. 43 to 59%) of the a-hydrogen aspartic and glutamic amino acids were measured in Tagish Lake, whereas alanine, another alpha-hydrogen protein amino acid, was found to be nearly racemic (D approx. L) using both techniques. Carbon isotope measurements of D- and L-aspartic acid and D- and L-alanine in Tagish Lake fall well outside of the terrestrial range and indicate that the measured aspartic acid enantioenrichment is indigenous to the meteorite. Alternate explanations for the Lexcesses of aspartic acid such as interference from other compounds present in the sample, analytical biases, or terrestrial amino acid contamination were investigated and rejected. These results can be explained by differences in the solid-solution phase behavior of aspartic acid, which can form conglomerate enantiopure solids during crystallization, and alanine, which can only form racemic crystals.

A facile stereospecific synthesis of the ( sup 2 H sub 6 )-isopropyl-labelled metoprolol enantiomers from (2R)- and (2S)-glycidyl 3-nitrobenzenesulfonate

Energy Technology Data Exchange (ETDEWEB)

Murthy, S.S.; Nelson, W.L. (Washington Univ., Seattle, WA (USA). Dept. of Medicinal Chemistry)

1990-12-01

Enantiomers of metoprolol containing six deuterium atoms in the isopropyl methyl groups were prepared in two steps from the sodium salt of 4-(2-methoxyethyl)phenol (3) and the commercially available (2R)-and (2S)-glycidyl 3-nitrobenzenesulfonates ((2R)-2 and (2S)-2). The resulting (2R)- and (2S)-epoxides were opened using ({sup 2}H{sub 6})-isopropylamine. The enantiomeric excesses were 93 and 95% for the deuterated (2R)- and (2S)-enantiomers of metoprolol ((2R)-1 and (2S)-1), respectively, as determined by chiral column HPLC. (author).

Enantioselective synthesis of both (-)-(R)-and (+)-(S)-angustureine controlled by enzymatic resolution

Energy Technology Data Exchange (ETDEWEB)

Diaz, Gaspar, E-mail: gaspardm@qui.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Inst. de Ciencias Exatas. Dept. de Qumica; Diaz, Marisa A.N. [Universidade Federal de Vicosa, MG (Brazil). Dept. de Bioquimica e Biologia Molecular; Reis, Marco A. [Centro Federal de Educacao Tecnologica (CEFET), Belo Horizonte, MG (Brazil). Dept. de Quimica

2013-09-15

The present study describes a new synthesis of (-)-(R)- and (+)-(S)-angustureine enantiomers, as well as of racemate ({+-})-angustureine, from a racemic {beta}-amino ester controlled by kinetic enzymatic resolution. This strategy allowed to incorporate the basic skeleton, as well as to control the single stereocenter at carbon 2 in both enantiomers. The sequence of five steps starting from the chiral {beta}-amino ester and sodium carboxylate for the synthesis of both alkaloids achieved overall yields of 80 and 44%, respectively, and produced excellent enantiomeric excesses (95 and 96%, respectively) with no protection of functional groups in any of the steps. (author)

Combining Organometallic Catalysis and Organocatalysis for the Synthesis of Heterocyclic Scaffolds

DEFF Research Database (Denmark)

Hansen, Casper Lykke

The main work presented in this thesis describes the development of efficient and novel methodologies for the synthesis of pharmaceutically interesting indolecontaining alkaloids, i.e., the 1,2,3,4-tetrahydro-β-carboline and the 1,2,3,4-tetrahydrocarbazole scaffolds. The synthesis of 1...... to the nitrogen in the allylic system proved to be highly important for the enantioselectivity. Enantiomeric excesses up to 57% was obtained. The synthesis of 1,2,3,4-tetrahydrocarbazole relied on novel Brønsted acidcatalyzed Friedel-Crafts-type reactions. Three different kinds of 1,2,3,4-tetrahydrocarbazole...

Stereoselective chemoenzymatic synthesis of the four stereoisomers of l-2-(2-carboxycyclobutyl)glycine and pharmacological characterization at human excitatory amino acid transporter subtypes 1, 2, and 3

DEFF Research Database (Denmark)

Faure, Sophie; Jensen, Anders A.; Maurat, Vincent

2006-01-01

The four stereoisomers of l-2-(2-carboxycyclobutyl)glycine, l-CBG-I, l-CBG-II, l-CBG-III, and l-CBG-IV, were synthesized in good yield and high enantiomeric excess, from the corresponding cis and trans-2-oxalylcyclobutanecarboxylic acids 5 and 6 using the enzymes aspartate aminotransferase (AAT......) and branched chain aminotransferase (BCAT) from Escherichia coli. The four stereoisomeric compounds were evaluated as potential ligands for the human excitatory amino acid transporters, subtypes 1, 2, and 3 (EAAT1, EAAT2, and EAAT3) in the FLIPR membrane potential assay. While the one trans-stereoisomer, l...

Chirality sensing with stereodynamic biphenolate zinc complexes.

Science.gov (United States)

Bentley, Keith W; de Los Santos, Zeus A; Weiss, Mary J; Wolf, Christian

2015-10-01

Two bidentate ligands consisting of a fluxional polyarylacetylene framework with terminal phenol groups were synthesized. Reaction with diethylzinc gives stereodynamic complexes that undergo distinct asymmetric transformation of the first kind upon binding of chiral amines and amino alcohols. The substrate-to-ligand chirality imprinting at the zinc coordination sphere results in characteristic circular dichroism signals that can be used for direct enantiomeric excess (ee) analysis. This chemosensing approach bears potential for high-throughput ee screening with small sample amounts and reduced solvent waste compared to traditional high-performance liquid chromatography methods. © 2015 Wiley Periodicals, Inc.

Efficient Asymmetric Synthesis of S,S-2-methylsulfanyl-2-methylsulfinyl-1-indanone

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Derisvaldo Rosa Paiva

2013-05-01

Full Text Available Diastereoselective synthesis of SS-2-methylsulfanyl-2-methylsulfinyl-1-indanol by reduction of SS-2-methylsulfanyl-2-methylsulfinyl-1-indanone optically enriched demonstrating to be highly efficiency using the sulfanyl group as asymmetric induction control agent during an addition reaction to carbonyl group.The 2-methylsulfinyl-1-indanone was obtained for the first time in one unique step without further oxidation steps. The synthesis of SR, SS of 2-methylsulphinyl-1-indanone optically enriched in good yield and good enantiomeric excess determined by nuclear magnetic resonance technique employing the Kagan reagent as chiral shift agent.

Enantioselective synthesis of both (-)-(R)-and (+)-(S)-angustureine controlled by enzymatic resolution

International Nuclear Information System (INIS)

Diaz, Gaspar; Diaz, Marisa A.N.; Reis, Marco A.

2013-01-01

The present study describes a new synthesis of (-)-(R)- and (+)-(S)-angustureine enantiomers, as well as of racemate (±)-angustureine, from a racemic β-amino ester controlled by kinetic enzymatic resolution. This strategy allowed to incorporate the basic skeleton, as well as to control the single stereocenter at carbon 2 in both enantiomers. The sequence of five steps starting from the chiral β-amino ester and sodium carboxylate for the synthesis of both alkaloids achieved overall yields of 80 and 44%, respectively, and produced excellent enantiomeric excesses (95 and 96%, respectively) with no protection of functional groups in any of the steps. (author)

Utilising excess minibus-taxi capacity for South African townships tours

NARCIS (Netherlands)

Rietjens, S.J.H.; Makoriwa, Collins; de Boer, S.J.

2006-01-01

This paper proposes an option for the utilisation of excess off-peak capacity of minibus-taxis in South Africa for township tours. The minibus-taxi system typically faces steep peak loads during rush hours with excess vehicle and person capacity available during off-hours. The advantages of the

Goodwill, Excess Returns, and Determinants of Value Creation and Overpayment

NARCIS (Netherlands)

Lycklama a Nijeholt, M.; Grift, Y.K.|info:eu-repo/dai/nl/073586358

2007-01-01

In this article we have investigated whether the determinants of excess returns (especially of target excess returns) are valid for purchased goodwill as well. Among them are acquirer’s and target’s Tobin’s q, and debt assets ratio, that explain value creation of acquisitions, and relative size,

Teachers' Knowledge of Anxiety and Identification of Excessive Anxiety in

Science.gov (United States)

Headley, Clea; Campbell, Marilyn A.

2013-01-01

This study examined primary school teachers' knowledge of anxiety and excessive anxiety symptoms in children. Three hundred and fifteen primary school teachers completed a questionnaire exploring their definitions of anxiety and the indications they associated with excessive anxiety in primary school children. Results showed that teachers had an…

Fetal Programming of Obesity: Maternal Obesity and Excessive Weight Gain

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Seray Kabaran

2014-10-01

Full Text Available The prevalence of obesity is an increasing health problem throughout the world. Maternal pre-pregnancy weight, maternal nutrition and maternal weight gain are among the factors that can cause childhood obesity. Both maternal obesity and excessive weight gain increase the risks of excessive fetal weight gain and high birth weight. Rapid weight gain during fetal period leads to changes in the newborn body composition. Specifically, the increase in body fat ratio in the early periods is associated with an increased risk of obesity in the later periods. It was reported that over-nutrition during fetal period could cause excessive food intake during postpartum period as a result of metabolic programming. By influencing the fetal metabolism and tissue development, maternal obesity and excessive weight gain change the amounts of nutrients and metabolites that pass to the fetus, thus causing excessive fetal weight gain which in turn increases the risk of obesity. Fetal over-nutrition and excessive weight gain cause permanent metabolic and physiologic changes in developing organs. While mechanisms that affect these organs are not fully understood, it is thought that the changes may occur as a result of the changes in fetal energy metabolism, appetite control, neuroendocrine functions, adipose tissue mass, epigenetic mechanisms and gene expression. In this review article, the effects of maternal body weight and weight gain on fetal development, newborn birth weight and risk of obesity were evaluated, and additionally potential mechanisms that can explain the effects of fetal over-nutrition on the risk of obesity were investigated [TAF Prev Med Bull 2014; 13(5.000: 427-434

Causes, Patterns, and Severity of Androgen Excess in 1205 Consecutively Recruited Women.

Science.gov (United States)

Elhassan, Yasir S; Idkowiak, Jan; Smith, Karen; Asia, Miriam; Gleeson, Helena; Webster, Rachel; Arlt, Wiebke; O'Reilly, Michael W

2018-03-01

Androgen excess in women is predominantly due to underlying polycystic ovary syndrome (PCOS). However, there is a lack of clarity regarding patterns and severity of androgen excess that should be considered predictive of non-PCOS pathology. We examined the diagnostic utility of simultaneous measurement of serum dehydroepiandrosterone sulfate (DHEAS), androstenedione (A4), and testosterone (T) to delineate biochemical signatures and cutoffs predictive of non-PCOS disorders in women with androgen excess. Retrospective review of all women undergoing serum androgen measurement at a large tertiary referral center between 2012 and 2016. Serum A4 and T were measured by tandem mass spectrometry and DHEAS by immunoassay. Patients with at least one increased serum androgen underwent phenotyping by clinical notes review. In 1205 women, DHEAS, A4, and T were measured simultaneously. PCOS was the most common diagnosis in premenopausal (89%) and postmenopausal women (29%). A4 was increased in all adrenocortical carcinoma (ACC) cases (n = 15) and T in all ovarian hyperthecosis (OHT) cases (n = 7); all but one case of congenital adrenal hyperplasia (CAH; n = 18) were identified by increased levels of A4 and/or T. In premenopausal women, CAH was a prevalent cause of severe A4 (59%) and T (43%) excess; severe DHEAS excess was predominantly due to PCOS (80%). In postmenopausal women, all cases of severe DHEAS and A4 excess were caused by ACC and severe T excess equally by ACC and OHT. Pattern and severity of androgen excess are important predictors of non-PCOS pathology and may be used to guide further investigations as appropriate.

Asymmetric Dark Matter Models and the LHC Diphoton Excess

DEFF Research Database (Denmark)

Frandsen, Mads T.; Shoemaker, Ian M.

2016-01-01

The existence of dark matter (DM) and the origin of the baryon asymmetry are persistent indications that the SM is incomplete. More recently, the ATLAS and CMS experiments have observed an excess of diphoton events with invariant mass of about 750 GeV. One interpretation of this excess is decays...... have for models of asymmetric DM that attempt to account for the similarity of the dark and visible matter abundances....

Energy potential of the modified excess sludge

Science.gov (United States)

Zawieja, Iwona

2017-11-01

On the basis of the SCOD value of excess sludge it is possible to estimate an amount of energy potentially obtained during the methane fermentation process. Based on a literature review, it has been estimated that from 1 kg of SCOD it is possible to obtain 3.48 kWh of energy. Taking into account the above methane and energy ratio (i.e. 10 kWh/1Nm3 CH4), it is possible to determine the volume of methane obtained from the tested sludge. Determination of potential energy of sludge is necessary for the use of biogas as a source of power generators as cogeneration and ensure the stability of this type of system. Therefore, the aim of the study was to determine the energy potential of excess sludge subjected to the thermal and chemical disintegration. In the case of thermal disintegration, test was conducted in the low temperature 80°C. The reagent used for the chemical modification was a peracetic acid, which in an aqueous medium having strong oxidizing properties. The time of chemical modification was 6 hours. Applied dose of the reagent was 1.0 ml CH3COOOH/L of sludge. By subjecting the sludge disintegration by the test methods achieved an increase in the SCOD value of modified sludge, indicating the improvement of biodegradability along with a concomitant increase in their energy potential. The obtained experimental production of biogas from disintegrated sludge confirmed that it is possible to estimate potential intensity of its production. The SCOD value of 2576 mg O2/L, in the case of chemical disintegration, was obtained for a dose of 1.0 ml CH3COOH/L. For this dose the pH value was equal 6.85. In the case of thermal disintegration maximum SCOD value was 2246 mg O2/L obtained at 80°C and the time of preparation 6 h. It was estimated that in case of thermal disintegration as well as for the chemical disintegration for selected parameters, the potential energy for model digester of active volume of 5L was, respectively, 0.193 and 0,118 kWh.

Energy potential of the modified excess sludge

Directory of Open Access Journals (Sweden)

Zawieja Iwona

2017-01-01

Full Text Available On the basis of the SCOD value of excess sludge it is possible to estimate an amount of energy potentially obtained during the methane fermentation process. Based on a literature review, it has been estimated that from 1 kg of SCOD it is possible to obtain 3.48 kWh of energy. Taking into account the above methane and energy ratio (i.e. 10 kWh/1Nm3 CH4, it is possible to determine the volume of methane obtained from the tested sludge. Determination of potential energy of sludge is necessary for the use of biogas as a source of power generators as cogeneration and ensure the stability of this type of system. Therefore, the aim of the study was to determine the energy potential of excess sludge subjected to the thermal and chemical disintegration. In the case of thermal disintegration, test was conducted in the low temperature 80°C. The reagent used for the chemical modification was a peracetic acid, which in an aqueous medium having strong oxidizing properties. The time of chemical modification was 6 hours. Applied dose of the reagent was 1.0 ml CH3COOOH/L of sludge. By subjecting the sludge disintegration by the test methods achieved an increase in the SCOD value of modified sludge, indicating the improvement of biodegradability along with a concomitant increase in their energy potential. The obtained experimental production of biogas from disintegrated sludge confirmed that it is possible to estimate potential intensity of its production. The SCOD value of 2576 mg O2/L, in the case of chemical disintegration, was obtained for a dose of 1.0 ml CH3COOH/L. For this dose the pH value was equal 6.85. In the case of thermal disintegration maximum SCOD value was 2246 mg O2/L obtained at 80°C and the time of preparation 6 h. It was estimated that in case of thermal disintegration as well as for the chemical disintegration for selected parameters, the potential energy for model digester of active volume of 5L was, respectively, 0.193 and 0,118 kWh.

Epilepsy, excess deaths and years of life lost from external causes.

Science.gov (United States)

Nevalainen, Olli; Simola, Mikko; Ansakorpi, Hanna; Raitanen, Jani; Artama, Miia; Isojärvi, Jouko; Auvinen, Anssi

2016-05-01

We systematically quantified excess mortality in epilepsy patients by cause of death using the population-attributable fraction and epilepsy-attributable years of potential life lost (YPLL) by age 75 years at ages 15 and over. We updated and undertook a re-review of mortality studies from our previous systematic review following PRISMA guidelines to identify cohort studies of general epilepsy populations reporting a relative risk (RR) of death by cause relative to the background rates in the population. Studies on epilepsy prevalence were identified through published reviews. Country-specific mortality figures were obtained from the WHO World Mortality Database. We performed a pooled analysis with the DerSimonian-Laird random effects method. In countries with very high Human Development Indices, epilepsy contributed to 0.5-1.1 % of all deaths in the total population. Among external causes, suicides (RR 2.9, 95 % confidence interval 2.2-3.8; I(2) 52 %) were the major contributor to YPLL, corresponding to 6.7 % and 4.2 % of excess YPLL due to epilepsy in the United States (US) and in the United Kingdom (UK) in 2010, with 541 (346-792) and 44 (28-65) excess suicide cases, respectively. Fatal accidental falls were more common, with 813 (610-1064) and 95 (71-125) excess deaths in the US and in the UK, but these caused only 2.0 % of excess YPLL as they occurred in older age groups. Suicides were the most important external cause of death in epilepsy patients in terms of excess YPLL, whereas other external causes were either more common in older ages or caused less excess deaths.

Excess co-movement in asset prices: The case of South Africa

OpenAIRE

Ocran, Mathew; Mlambo, Chipo

2009-01-01

The paper investigates excess co-movement in asset prices in South Africa between 1995 and 2005 using the definition of excess comovement as correlation between two asset prices beyond what could be explained by key economic fundamentals. The results of the study suggest that there is excess co-movement between returns on equities and bonds in South Africa. The findings suggest that there are considerable noise traders on the financial market in South Africa. The result of this behaviour woul...

IPHAS A-TYPE STARS WITH MID-INFRARED EXCESSES IN SPITZER SURVEYS

International Nuclear Information System (INIS)

Hales, Antonio S.; Barlow, Michael J.; Drew, Janet E.; Unruh, Yvonne C.; Greimel, Robert; Irwin, Michael J.; Gonzalez-Solares, Eduardo

2009-01-01

We have identified 17 A-type stars in the Galactic Plane that have mid-infrared (mid-IR) excesses at 8 μm. From observed colors in the (r' - Hα) - (r' - i') plane, we first identified 23,050 early A-type main-sequence (MS) star candidates in the Isaac Newton Photometric H-Alpha Survey (IPHAS) point source database that are located in Spitzer Galactic Legacy Mid-Plane Survey Extraordinaire Galactic plane fields. Imposing the requirement that they be detected in all seven Two Micron All Sky Survey and Infrared Astronomical Satellite bands led to a sample of 2692 candidate A-type stars with fully sampled 0.6 to 8 μm spectral energy distributions (SEDs). Optical classification spectra of 18 of the IPHAS candidate A-type MS stars showed that all but one could be well fitted using MS A-type templates, with the other being an A-type supergiant. Out of the 2692 A-type candidates 17 (0.6%) were found to have 8 μm excesses above the expected photospheric values. Taking into account non-A-Type contamination estimates, the 8 μm excess fraction is adjusted to ∼0.7%. The distances to these sources range from 0.7 to 2.5 kpc. Only 10 out of the 17 excess stars had been covered by Spitzer MIPSGAL survey fields, of which five had detectable excesses at 24 μm. For sources with excesses detected in at least two mid-IR wavelength bands, blackbody fits to the excess SEDs yielded temperatures ranging from 270 to 650 K, and bolometric luminosity ratios L IR /L * from 2.2 x 10 -3 - 1.9 x 10 -2 , with a mean value of 7.9 x 10 -3 (these bolometric luminosities are lower limits as cold dust is not detectable by this survey). Both the presence of mid-IR excesses and the derived bolometric luminosity ratios are consistent with many of these systems being in the planet-building transition phase between the early protoplanetary disk phase and the later debris disk phase.

Is Excessive Polypharmacy a Transient or Persistent Phenomenon? A Nationwide Cohort Study in Taiwan

Science.gov (United States)

Wang, Yi-Jen; Chiang, Shu-Chiung; Lee, Pei-Chen; Chen, Yu-Chun; Chou, Li-Fang; Chou, Yueh-Ching; Chen, Tzeng-Ji

2018-01-01

Objectives: Target populations with persistent polypharmacy should be identified prior to implementing strategies against inappropriate medication use, yet limited information regarding such populations is available. The main objectives were to explore the trends of excessive polypharmacy, whether transient or persistent, at the individual level. The secondary objectives were to identify the factors associated with persistently excessive polypharmacy and to estimate the probabilities for repeatedly excessive polypharmacy. Methods: Retrospective cohort analyses of excessive polypharmacy, defined as prescription of ≥ 10 medicines at an ambulatory visit, from 2001 to 2013 were conducted using a nationally representative claims database in Taiwan. Survival analyses with log-rank test of adult patients with first-time excessive polypharmacy were conducted to predict the probabilities, stratified by age and sex, of having repeatedly excessive polypharmacy. Results: During the study period, excessive polypharmacy occurred in 5.4% of patients for the first time. Among them, 63.9% had repeatedly excessive polypharmacy and the probabilities were higher in men and old people. Men versus women, and old versus middle-aged and young people had shorter median excessive polypharmacy-free times (9.4 vs. 5.5 months, 5.3 vs. 10.1 and 35.0 months, both p < 0.001). Overall, the probabilities of having no repeatedly excessive polypharmacy within 3 months, 6 months, and 1 year were 59.9, 53.6, and 48.1%, respectively. Conclusion: Although male and old patients were more likely to have persistently excessive polypharmacy, most cases of excessive polypharmacy were transient or did not re-appear in the short run. Systemic deprescribing measures should be tailored to at-risk groups. PMID:29515446

Is Excessive Polypharmacy a Transient or Persistent Phenomenon? A Nationwide Cohort Study in Taiwan

Directory of Open Access Journals (Sweden)

Yi-Jen Wang

2018-02-01

Full Text Available Objectives: Target populations with persistent polypharmacy should be identified prior to implementing strategies against inappropriate medication use, yet limited information regarding such populations is available. The main objectives were to explore the trends of excessive polypharmacy, whether transient or persistent, at the individual level. The secondary objectives were to identify the factors associated with persistently excessive polypharmacy and to estimate the probabilities for repeatedly excessive polypharmacy.Methods: Retrospective cohort analyses of excessive polypharmacy, defined as prescription of ≥ 10 medicines at an ambulatory visit, from 2001 to 2013 were conducted using a nationally representative claims database in Taiwan. Survival analyses with log-rank test of adult patients with first-time excessive polypharmacy were conducted to predict the probabilities, stratified by age and sex, of having repeatedly excessive polypharmacy.Results: During the study period, excessive polypharmacy occurred in 5.4% of patients for the first time. Among them, 63.9% had repeatedly excessive polypharmacy and the probabilities were higher in men and old people. Men versus women, and old versus middle-aged and young people had shorter median excessive polypharmacy-free times (9.4 vs. 5.5 months, 5.3 vs. 10.1 and 35.0 months, both p < 0.001. Overall, the probabilities of having no repeatedly excessive polypharmacy within 3 months, 6 months, and 1 year were 59.9, 53.6, and 48.1%, respectively.Conclusion: Although male and old patients were more likely to have persistently excessive polypharmacy, most cases of excessive polypharmacy were transient or did not re-appear in the short run. Systemic deprescribing measures should be tailored to at-risk groups.

Enantiomeric and Diastereomeric Self-Assembled Multivalent (SAMul) Nanostructures - Understanding the Effects of Chirality on Binding to Polyanionic Heparin and DNA.

Science.gov (United States)

Thornalley, Kiri; Laurini, Erik; Pricl, Sabrina; Smith, David K

2018-05-15

A family of four self-assembling lipopeptides containing Ala-Lys peptides attached to a C16 aliphatic chain was synthesised. These compounds form two enantiomeric pairs that bear a diastereomeric relationship to one another (C16-L-Ala-L-Lys/C16-D-Ala-D-Lys) and (C16-D-Ala-L-Lys/C16-L-Ala-D-Lys). These diastereomeric pairs have very different critical micelle concentrations (CMCs), with LL/DD < DL/LD suggesting more effective assembly of the former. The self-assembled multivalent (SAMul) systems bind biological polyanions as result of the cationic lysine groups on their surfaces. Polyanion binding was investigated using dye displacement assays and isothermal calorimetry (ITC). On heparin binding, there was no significant enantioselectivity, but there was a binding preference for the diastereomeric assemblies with lower CMCs. Conversely, on binding DNA, there was a significant enantioselective preference for systems displaying D-lysine ligands, with a further slight preference for attachment to L-alanine, with the CMC being irrelevant. Binding to adaptive, ill-defined heparin has a large favourable entropic term, suggesting it depends primarily on the cationic SAMul nanostructure maximising surface contact with heparin, which can adapt, displacing solvent and other ions. Conversely, binding to well-defined, shape-persistent DNA has a larger favourable enthalpic term, and combined with the enantioselectivity, this allows us to suggest that its SAMul binding is based on optimised individual electrostatic interactions at the molecular level, with a preference for binding to D-lysine. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Response of hippocampal mossy fiber zinc to excessive glutamate release.

Science.gov (United States)

Takeda, Atsushi; Minami, Akira; Sakurada, Naomi; Nakajima, Satoko; Oku, Naoto

2007-01-01

The response of hippocampal mossy fiber zinc to excessive glutamate release was examined to understand the role of the zinc in excessive excitation in the hippocampus. Extracellular zinc and glutamate concentrations during excessive stimulation with high K(+) were compared between the hippocampal CA3 and CA1 by the in vivo microdialysis. Zinc concentration in the CA3 was more increased than that in the CA1, while glutamate concentration in the CA3 was less increased than that in the CA1. It is likely that more increase in extracellular zinc is linked with less increase in extracellular glutamate in the CA3. To see zinc action in mossy fiber synapses during excessive excitation, furthermore, 1mM glutamate was regionally delivered to the stratum lucidum in the presence of zinc or CaEDTA, a membrane-impermeable zinc chelator, and intracellular calcium signal was measured in the CA3 pyramidal cell layer. The persistent increase in calcium signal during stimulation with glutamate was significantly attenuated in the presence of 100 microM zinc, while significantly enhanced in the presence of 1mM CaEDTA. These results suggest that zinc released from mossy fibers attenuates the increase in intracellular calcium signal in mossy fiber synapses and postsynaptic CA3 neurons after excessive inputs to dentate granular cells.

THE MID-INFRARED AND NEAR-ULTRAVIOLET EXCESS EMISSIONS OF QUIESCENT GALAXIES ON THE RED SEQUENCE

International Nuclear Information System (INIS)

Ko, Jongwan; Lee, Jong Chul; Hwang, Ho Seong; Sohn, Young-Jong

2013-01-01

We study the mid-infrared (IR) and near-ultraviolet (UV) excess emissions of spectroscopically selected quiescent galaxies on the optical red sequence. We use the Wide-field Infrared Survey Explorer mid-IR and Galaxy Evolution Explorer near-UV data for a spectroscopic sample of galaxies in the Sloan Digital Sky Survey Data Release 7 to study the possible connection between quiescent red-sequence galaxies with and without mid-IR/near-UV excess. Among 648 12 μm detected quiescent red-sequence galaxies without Hα emission, 26% and 55% show near-UV and mid-IR excess emissions, respectively. When we consider only bright (M r n 4000 than those without mid-IR and near-UV excess emissions. We also find that mid-IR weighted mean stellar ages of quiescent red-sequence galaxies with mid-IR excess are larger than those with near-UV excess, and smaller than those without mid-IR and near-UV excess. The environmental dependence of the fraction of quiescent red-sequence galaxies with mid-IR and near-UV excess seems strong even though the trends of quiescent red-sequence galaxies with near-UV excess differ from those with mid-IR excess. These results indicate that the recent star formation traced by near-UV (∼< 1 Gyr) and mid-IR (∼< 2 Gyr) excess is not negligible among nearby, quiescent, red, early-type galaxies. We suggest a possible evolutionary scenario of quiescent red-sequence galaxies from quiescent red-sequence galaxies with near-UV excess to those with mid-IR excess to those without near-UV and mid-IR excess.

Luminosity excesses in low-mass young stellar objects - a statistical study

International Nuclear Information System (INIS)

Strom, K.M.; Strom, S.E.; Kenyon, S.J.; Hartmann, L.

1988-01-01

This paper presents a statistical study in which the observed total luminosity is compared quantitatively with an estimate of the stellar luminosity for a sample of 59 low-mass young stellar objects (YSOs) in the Taurus-Auriga complex. In 13 of the analyzed YSOs, luminosity excesses greater than 0.20 are observed together with greater than 0.6 IR excesses, which typically contribute the bulk of the observed excess luminosity and are characterized by spectral energy distributions which are flat or rise toward long wavelengths. The analysis suggests that YSOs showing the largest luminosity excesses typically power optical jets and/or molecular outflows or have strong winds, as evidenced by the presence of O I emission, indicating a possible correlation between accretion and mass-outflow properties. 38 references

Effect of excess ozone on UV-stimulated tritium oxidation

International Nuclear Information System (INIS)

Hasegawa, Kiyoshi; Horii, Kazuhiro; Matsuyama, Masao; Watanabe, Kuniaki.

1995-01-01

The authors have reported that the oxidation of tritium is considerably accelerated by irradiating a mixture gas of HT(H 2 )-O 2 with UV-photons, and this UV-stimulated HT oxidation is mainly due to the formation of intermediates such as ozone and activated oxygen species. This suggests that the oxidation will be much more enhanced in the presence of excess ozone in the reaction system. To examine this possibility, effects of the excess ozone on the UV-stimulated HT oxidation was experimentally studied on the one hand, and reaction mechanisms were investigated by developing a computer simulation program applicable to the three-component system of HT(H 2 )-O 2 -O 3 . The formation rate of HTO was measured for gas mixtures consisting of O 2 (75.5 Torr), O 3 (0.5-2% of O 2 ), H 2 (0.1-3% of O 2 ) and HT(H 2 /HT=12000). The experiments showed considerable enhancement of the HTO production rate in the presence of excess ozone by UV-photons from a low pressure mercury lamp(5W). The time course of the reaction was reproduced quite well by computer simulation, indicating that the assumed reaction mechanism is valid. This is also supported by observations that computer simulation reproduced the experimentally observed dependence of ozone decomposition rate on ozone and hydrogen pressures under the UV-irradiation. Those results showed that UV-stimulated HT oxidation was accelerated by about 14000 times in the presence of excess ozone. It strongly suggests that the UV-stimulated oxidation in the presence of excess ozone will be applicable to tritium handling systems as a non-catalytic tritium removal method. (author)

VARIABILITY OF THE INFRARED EXCESS OF EXTREME DEBRIS DISKS

International Nuclear Information System (INIS)

Meng, Huan Y. A.; Rieke, George H.; Su, Kate Y. L.; Rujopakarn, Wiphu; Ivanov, Valentin D.; Vanzi, Leonardo

2012-01-01

Debris disks with extremely large infrared excesses (fractional luminosities >10 –2 ) are rare. Those with ages between 30 and 130 Myr are of interest because their evolution has progressed well beyond that of protoplanetary disks (which dissipate with a timescale of order 3 Myr), yet they represent a period when dynamical models suggest that terrestrial planet building may still be progressing through large, violent collisions that could yield large amounts of debris and large infrared excesses. For example, our Moon was formed through a violent collision of two large protoplanets during this age range. We report two disks around the solar-like stars ID8 and HD 23514 in this age range where the 24 μm infrared excesses vary on timescales of a few years, even though the stars are not variable in the optical. Variations this rapid are difficult to understand if the debris is produced by collisional cascades, as it is for most debris disks. It is possible that the debris in these two systems arises in part from condensates from silicate-rich vapor produced in a series of violent collisions among relatively large bodies. If their evolution is rapid, the rate of detection of extreme excesses would indicate that major collisions may be relatively common in this age range.

Excess isentropic compressibility and speed of sound of the ternary

Indian Academy of Sciences (India)

These excess properties of the binary mixtures were fitted to Redlich-Kister equation, while the Cibulka's equation was used to fit the values related to the values to the ternary system. These excess properties have been used to discuss the presence of significant interactions between the component molecules in the binary ...

26 CFR 1.1238-1 - Amortization in excess of depreciation.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 11 2010-04-01 2010-04-01 true Amortization in excess of depreciation. 1.1238-1... Amortization in excess of depreciation. (a) In general. Section 1238 provides that if a taxpayer is entitled to... amortization deduction exceeds normal depreciation. Thus, under section 1238 gain from a sale or exchange of...

Simulation and analysis of multi-stage centrifugal fractional extraction process of 4-nitrobenzene glycine enantiomers☆

Institute of Scientific and Technical Information of China (English)

Ping Wen; Kewen Tang; Jicheng Zhou; Panliang Zhang

2015-01-01

Based on the interfacial ligand exchange model and the law of conservation of mass, the multi-stage enantioselective liquid–liquid extraction model has been established to analyze and discuss on multi-stage centrifugal fractional extraction process of 4-nitrobenzene glycine (PGL) enantiomers. The influence of phase ratio, extractant concentra-tion, and PF6−concentration on the concentrations of enantiomers in the extract and raffinate was investigated by experiment and simulation. A good agreement between model and experiment was obtained. On this basis, the influence of many parameters such as location of stage, concentration levels, extractant excess, and number of stages on the symmetric separation performance was simulated. The optimal location of feed stage is the middle of fractional extraction equipment. The feed flow must satisfy a restricted relationship on flow ratios and the liquid throughout of centrifugal device. For desired purity specification, the required flow ratios decrease with extractant concentration and increase with PF6−concentration. When the number of stages is 18 stages at extractant excess of 1.0 or 14 stages at extractant excess of 2.0, the eeeq (equal enantiomeric excess) can reach to 99%.

Control rod excess withdrawal prevention device

International Nuclear Information System (INIS)

Takayama, Yoshihito.

1992-01-01

Excess withdrawal of a control rod of a BWR type reactor is prevented. That is, the device comprises (1) a speed detector for detecting the driving speed of a control rod, (2) a judging circuit for outputting an abnormal signal if the driving speed is greater than a predetermined level and (3) a direction control valve compulsory closing circuit for controlling the driving direction of inserting and withdrawing a control rod based on an abnormal signal. With such a constitution, when the with drawing speed of a control rod is greater than a predetermined level, it is detected by the speed detector and the judging circuit. Then, all of the direction control valve are closed by way of the direction control valve compulsory closing circuit. As a result, the operation of the control rod is stopped compulsorily and the withdrawing speed of the control rod can be lowered to a speed corresponding to that upon gravitational withdrawal. Accordingly, excess withdrawal can be prevented. (I.S)

Excess fertilizer responsive miRNAs revealed in Linum usitatissimum L.

Science.gov (United States)

Melnikova, Nataliya V; Dmitriev, Alexey A; Belenikin, Maxim S; Speranskaya, Anna S; Krinitsina, Anastasia A; Rachinskaia, Olga A; Lakunina, Valentina A; Krasnov, George S; Snezhkina, Anastasiya V; Sadritdinova, Asiya F; Uroshlev, Leonid A; Koroban, Nadezda V; Samatadze, Tatiana E; Amosova, Alexandra V; Zelenin, Alexander V; Muravenko, Olga V; Bolsheva, Nadezhda L; Kudryavtseva, Anna V

2015-02-01

Effective fertilizer application is necessary to increase crop yields and reduce risk of plant overdosing. It is known that expression level of microRNAs (miRNAs) alters in plants under different nutrient concentrations in soil. The aim of our study was to identify and characterize miRNAs with expression alterations under excessive fertilizer in agriculturally important crop - flax (Linum usitatissimum L.). We have sequenced small RNAs in flax grown under normal and excessive fertilizer using Illumina GAIIx. Over 14 million raw reads was obtained for two small RNA libraries. 84 conserved miRNAs from 20 families were identified. Differential expression was revealed for several flax miRNAs under excessive fertilizer according to high-throughput sequencing data. For 6 miRNA families (miR395, miR169, miR408, miR399, miR398 and miR168) expression level alterations were evaluated on the extended sampling using qPCR. Statistically significant up-regulation was revealed for miR395 under excessive fertilizer. It is known that target genes of miR395 are involved in sulfate uptake and assimilation. However, according to our data alterations of the expression level of miR395 could be associated not only with excess sulfur application, but also with redundancy of other macro- and micronutrients. Furthermore expression level was evaluated for miRNAs and their predicted targets. The negative correlation between miR399 expression and expression of its predicted target ubiquitin-conjugating enzyme E2 gene was shown in flax for the first time. So we suggested miR399 involvement in phosphate regulation in L. usitatissimum. Revealed in our study expression alterations contribute to miRNA role in flax response to excessive fertilizer. Copyright © 2014 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.

Financial costs due to excess health risks among active employees of a utility company.

Science.gov (United States)

Yen, Louis; Schultz, Alyssa; Schnueringer, Elaine; Edington, Dee W

2006-09-01

The objective of this study was to examine the health risk-related excess costs of time away from work, medical claims, pharmacy claims, and total costs with and without considering the prevalence of health risks. A total of 2082 of 4266 employees of a Midwest utility participated in a health risk appraisal (HRA). Individuals were classified by their HRA participation status and also by 15 health risks. Total and excess costs were analyzed for all employees. There were significant excess costs due to individual risks and overall excess health risks in all cost measures. Both excess cost per risk and prevalence of the risk were important factors in determining the excess costs in the population. As compared with low-risk participants, HRA nonparticipants and the medium- and high-risk participants were 1.99, 2.22, and 3.97 times more likely to be high cost status. Approximately one third of corporate costs in medical claims, pharmacy claims, and time away from work could be defined as excess costs associated with excess health risks.

Excess-pressure suppression device in a reactor container

International Nuclear Information System (INIS)

Nishio, Masahide

1985-01-01

Purpose: To reliably decrease the radioactivity of radioactive gases when they are released externally. Constitution: The exit of a gas exhaust pipe for discharging gases in a reactor container, on generation of an excess pressure in the reactor container upon loss of coolant accident, is adapted to be always fluided in the cooling tank. Then, the exhaust gases discharged in the cooling tank is realeased to the atmosphere. In this way, the excess pressure in the reactor container can be prevented previously and the radioactivity of the gases released externally is significantly reduced by the scrubbing effect. (Kamimura, M.)

Maternal anxiety disorders predict excessive infant crying: a prospective longitudinal study.

Science.gov (United States)

Petzoldt, Johanna; Wittchen, Hans-Ulrich; Wittich, Julia; Einsle, Franziska; Höfler, Michael; Martini, Julia

2014-09-01

To prospectively examine relations between maternal DSM-IV-TR anxiety and depressive disorders and excessive infant crying. Based on the prospective longitudinal Maternal Anxiety in Relation to Infant Development Study, n=306 expectant mothers were enrolled during early pregnancy and repeatedly interviewed until 16 months post partum. Lifetime and prospective information on maternal anxiety and depressive disorders was assessed via standardised diagnostic interviews (Composite International Diagnostic Interview for Women). Excessive crying (crying for ≥3 h per day on ≥3 days per week for ≥3 weeks) was assessed via Baby-DIPS. During the first 16 months after delivery, n=286 mother-infant dyads were available and included in the analyses. Excessive crying was reported by n=29 mothers (10.1%). Infants of mothers with anxiety disorders prior to pregnancy were at higher risk for excessive crying than infants of mothers without any anxiety disorder prior to pregnancy (OR=2.54, 95% CI 1.11 to 5.78, p=0.027). Risk was even increased when considering additionally incident anxiety disorders until delivery (OR=3.02, 95% CI 1.25 to 7.32, p=0.014) and until 16 months post partum (OR=2.87, 95% CI 1.13 to 7.28, p=0.027). Associations remained stable when adjusting for sociodemographic and perinatal covariates. Maternal depressive disorders prior to pregnancy were not significantly associated with excessive crying in this sample. Maternal lifetime and incident anxiety disorders revealed to be a robust predictor for excessive crying. Thus, early identification and monitoring of women with anxiety disorders is important to identify mother-infant dyads at risk for excessive crying. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Surgical-Orthodontic Treatment of Gummy Smile with Vertical Maxillary Excess

Directory of Open Access Journals (Sweden)

Sumit Kumar Yadav

2014-01-01

Full Text Available Vertical maxillary excess is a well-defined clinical entity with several treatment options available. Treatment of the condition requires extremely well-coordinated orthodontic and surgical treatment planning and execution. This case report describes a multidisciplinary approach in the successful management of a patient with severe vertical maxillary excess. Careful selection and good execution of a surgical-orthodontic treatment plan in the management of vertical maxillary excess provided the superior esthetic and functional results in this case. Maxillary Le Forte 1 procedure was performed for vertical maxillary impaction along with anterior segmental setback. The presented technique was unique as it shortened the treatment time and esthetic results in smile and vertical proportions were achieved.

A SUZAKU OBSERVATION OF Mkn 590 REVEALS A VANISHING SOFT EXCESS

Energy Technology Data Exchange (ETDEWEB)

Rivers, Elizabeth; Markowitz, Alex; Rothschild, Richard [Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0424 (United States); Duro, Refiz [Dr. Karl Remeis-Sternwarte and Erlangen Centre for Astroparticle Physics, Frederic-Alexander Universitaet Erlangen-Nuernberg, 7 Sternwartstrasse, D-96049 Bamberg (Germany)

2012-11-01

We have analyzed a long-look Suzaku observation of the Seyfert 1.2 Mkn 590. We aimed to measure the Compton reflection strength, Fe K complex properties, and soft excess emission as had been observed previously in this source. The Compton reflection strength was measured to be in the range 0.2-1.0 depending on the model used. A moderately strong Fe K{alpha} emission line was detected with an equivalent width of {approx}120 {+-} 25 eV and an Fe K{beta} line was identified with an equivalent width of {approx}30 {+-} 20 eV, although we could not rule out contribution from ionized Fe emission at this energy. Surprisingly, we found no evidence for soft excess emission. Comparing our results with a 2004 observation from XMM-Newton we found that either the soft excess has decreased by a factor of 20-30 in 7 years or the photon index has steepened by 0.10 (with no soft excess present) while the continuum flux in the range 2-10 keV has varied only minimally (10%). This result could support recent claims that the soft excess is independent of the X-ray continuum.

A SUZAKU OBSERVATION OF Mkn 590 REVEALS A VANISHING SOFT EXCESS

International Nuclear Information System (INIS)

Rivers, Elizabeth; Markowitz, Alex; Rothschild, Richard; Duro, Refiz

2012-01-01

We have analyzed a long-look Suzaku observation of the Seyfert 1.2 Mkn 590. We aimed to measure the Compton reflection strength, Fe K complex properties, and soft excess emission as had been observed previously in this source. The Compton reflection strength was measured to be in the range 0.2-1.0 depending on the model used. A moderately strong Fe Kα emission line was detected with an equivalent width of ∼120 ± 25 eV and an Fe Kβ line was identified with an equivalent width of ∼30 ± 20 eV, although we could not rule out contribution from ionized Fe emission at this energy. Surprisingly, we found no evidence for soft excess emission. Comparing our results with a 2004 observation from XMM-Newton we found that either the soft excess has decreased by a factor of 20-30 in 7 years or the photon index has steepened by 0.10 (with no soft excess present) while the continuum flux in the range 2-10 keV has varied only minimally (10%). This result could support recent claims that the soft excess is independent of the X-ray continuum.

Determination of the design excess reactivity for the TREAT Upgrade reactor

International Nuclear Information System (INIS)

Bhattacharyya, S.K.; Hanan, N.A.

1983-01-01

The excess reactivity designed to be built into a reactor core is a primary determinant of the fissile loadings of the fuel rods in the core. For the TREAT Upgrade (TU) reactor the considerations that enter into the determination of the excess reactivity are different from those of conventional power reactors. The reactor is designed to operate in an adiabatic transient mode for reactor safety in-pile test programs. The primary constituent of the excess reactivity is the calculated reactivity required to perform the most demanding transient experiments. Because of the unavailability of supporting critical experiments for the core design, the uncertainty terms that add on to this basic constituent are rather large. The burnup effects in TU are negligible and no refueling is planned. In this paper the determination of the design excess reactivity of the TREAT Upgrade reactor is discussed

Excessive prices as abuse of dominance?

DEFF Research Database (Denmark)

la Cour, Lisbeth; Møllgaard, Peter

2007-01-01

firm abused its position by charging excessive prices. We also test whether tightening of the Danish competition act has altered the pricing behaviour on the market. We discuss our results in the light of a Danish competition case against the dominant cement producer that was abandoned by the authority...

Excessive computer game playing : evidence for addiction and aggression?

OpenAIRE

Grüsser, SM; Thalemann, R; Griffiths, MD

2007-01-01

Computer games have become an ever-increasing part of many adolescents’ day-to-day lives. Coupled with this phenomenon, reports of excessive gaming (computer game playing) denominated as “computer/video game addiction” have been discussed in the popular press as well as in recent scientific research. The aim of the present study was the investigation of the addictive potential of gaming as well as the relationship between excessive gaming and aggressive attitudes and behavior. A sample compri...

Hotspot health physics codes used as a tool for managing excess risk on radiological emergencies

International Nuclear Information System (INIS)

Andrade, Edson Ramos de; Alves, Nelson Mendes; Rocha, Joao B.T.; Cruz, Ivana B. Manica da; Santos, Greice F. Fey dos; Machado, Michel Mansur; Rossato, Veronica Venturini; Bauermann, Liliane Freitas

2008-01-01

This work is aimed to use the Hotspot Health Physics codes in acute mode in order to estimate the immediate radiological impact associated with high acute radiation doses, which is applied to special target organs such as lung, small intestine wall, and red bone marrow. Organic compounds such as Diphenyl Diselenide (C 6 H 5 Se 2 C 6 H 5 ) and Ebselen (C 13 H 9 NOSe), an antioxidants selenium containing compounds, were used over irradiated phospholipids extracted from chicken yolk eggs, in vitro in order to reduce lipo-peroxidation. Experimental data were measured by Thiobarbituric Acid Reactive Substance (TBARS) assay which is able to measure the production of oxidative stress in the sample. Experimental data were extrapolated and applied as a reduction factors over equations for cancer excess risk calculation from BEIR V, for helping the decisonmaking process on Radiological Emergency Scenarios. (author)

Excessive sulfur supply reduces cadmium accumulation in brown rice (Oryza sativa L.)

International Nuclear Information System (INIS)

Fan Jianling; Hu Zhengyi; Ziadi, Noura; Xia Xu; Wu Congyanghui

2010-01-01

Human activities have resulted in cadmium (Cd) and sulfur (S) accumulation in paddy soils in parts of southern China. A combined soil-sand pot experiment was conducted to investigate the influence of excessive S supply on iron plaque formation and Cd accumulation in rice plants, using two Cd levels (0, 1.5 mg kg -1 ) combined with three S concentrations (0, 60, 120 mg kg -1 ). The results showed that excessive S supply significantly decreased Cd accumulation in brown rice due to the decrease of Cd availability and the increase of glutathione in rice leaves. But excessive S supply obviously increased Cd accumulation in roots due to the decrease of iron plaque formation on the root surface of rice. Therefore, excessive S supply may result in loss of rice yield, but it could effectively reduce Cd accumulation in brown rice exposed to Cd contaminated soils. - Excessive sulfur reduces cadmium accumulation in brown rice.

Fusion reaction using low energy neutron-excess nucleus beam

International Nuclear Information System (INIS)

Fukuda, Tomokazu

1994-01-01

The present state and the plan of the experiment of measuring the fusion reaction near barriers by using neutron-excess nucleus beam, which has been advanced at RIKEN are reported. One of the purposes of this experiment is the feasibility investigation of the fusion reaction by using neutron-excess nuclei, which is indispensable for synthesizing superheavy elements. It is intended to systematically explore some enhancing mechanism in the neutron-excess nuclei which are unfavorable in beam intensity. This research can become the good means to prove the dynamic behavior of the neutrons on the surfaces of nuclei in reaction. The fusion reaction of 27 Al + Au was measured by using the stable nucleus beam of 27 Al, and the results are shown. In order to know the low energy fusion reaction of 11 Li and 11 Be which are typical halo nuclei, the identification by characteristic α ray of composite nuclei is carried out in 7,9,11 Li + 209 Bi and 9,10,11 Be + 208 Pb. A new detector having high performance, New MUSIC, is being developed. As the experiment by using this detector, the efficient measurement of the fusion reaction by using heavy neutron-excess nuclei up to Ni is considered. An example of 8 Li + α → 11 B + n reaction for celestial body physics is mentioned. (K.I.)

Hydrogen-based industry from remote excess hydroelectricity

International Nuclear Information System (INIS)

Ouellette, N.; Rogner, H.-H.; Scott, D.S.

1997-01-01

This paper examines synergies, opportunities and barriers associated with hydrogen and excess hydro-electricity in remote areas. The work is based on a case study that examined the techno-economic feasibility of a new hydrogen-based industry using surplus/off-peak generating capacity of the Taltson Dam and Generating Station in the Northwest Territories, Canada. After evaluating the amount and cost of hydrogen that could be produced from the excess capacity, the study investigates three hydrogen utilization scenarios: (1) merchant liquid or compressed hydrogen, (2) hydrogen as a chemical feedstock for the production of hydrogen peroxide, (3) methanol production from biomass, oxygen and hydrogen. Hydrogen peroxide production is the most promising and attractive strategy in the Fort Smith context. The study also illustrates patterns that recur in isolated sites throughout the world. (Author)

A Three-Dimensional Foil Bearing Performance Map Applied to Oil-Free Turbomachinery

Science.gov (United States)

2009-04-01

stress brought on by excessive viscous power loss; therefore a map that graphically relates component and system-level parameters (bearing size, applied...Introduction Foil bearings are self-acting, hydrodynamic gas bearings that use air as their working fluid . Their use in rotating systems eliminates the...weight, maintenance requirements, speed, and temperature limitations associated with conventional oil-lubricated rotor supports (i.e., bearings, dampers

Enantiomeric separation and simulation studies of pheniramine, oxybutynin, cetirizine, and brinzolamide chiral drugs on amylose-based columns.

Science.gov (United States)

Ali, Imran; Al-Othman, Zeid A; Al-Warthan, Abdulrahman; Alam, Syed Dilshad; Farooqi, Javed A

2014-03-01

Solid phase extraction (SPE)-chiral separation of the important drugs pheniramine, oxybutynin, cetirizine, and brinzolamide was achieved on the C18 cartridge and AmyCoat (150 x 46 mm) and Chiralpak AD (25 cm x 0.46 cm id) chiral columns in human plasma. Pheniramine, oxybutynin, cetirizine, and brinzolamide were resolved using n-hexane-2-PrOH-DEA (85:15:0.1, v/v), n-hexane-2-PrOH-DEA (80:20:0.1, v/v), n-hexane-2-PrOH-DEA (70:30:0.2, v/v), and n-hexane-2-propanol (90:10, v/v) as mobile phases. The separation was carried out at 25 ± 1 ºC temperature with detection at 225 nm for cetirizine and oxybutynin and 220 nm for pheniramine and brinzolamide. The flow rates of the mobile phases were 0.5 mL min(-1). The retention factors of pheniramine, oxybutynin, cetirizine and brinzolamide were 3.25 and 4.34, 4.76 and 5.64, 6.10 and 6.60, and 1.64 and 2.01, respectively. The separation factors of these drugs were 1.33, 1.18, 1.09 and 1.20 while their resolutions factors were 1.09, 1.45, 1.63 and 1.25, and 1.15, respectively. The absolute configurations of the eluted enantiomers of the reported drugs were determined by simulation studies. It was observed that the order of enantiomers elution of the reported drugs was S-pheniramine > R-pheniramine; R-oxybutynin > S-oxybutynin; S-cetirizine > R-cetirizine; and S-brinzolamide > R-brinzolamide. The mechanism of separation was also determined at the supramolecular level by considering interactions and modeling results. The reported SPE-chiral high-performance liquid chromatography (HPLC) methods are suitable for the enantiomeric analyses of these drugs in any biological sample. In addition, simulation studies may be used to determine the absolute configuration of the first and second eluted enantiomers. © 2014 Wiley Periodicals, Inc.

Partner’s and own education: does who you live with matter for self-assessed health, smoking and excessive alcohol consumption?

OpenAIRE

Monden, Christiaan W.S.; Lenthe, Frank van; Graaf, Nan Dirk De; Kraaykamp, Gerbert

2003-01-01

This study analyses the importance of partner status and partner’s education, adjusted for own education, on selfassessed health, smoking and excessive alcohol consumption. The relationship between socio-economic factors and health-related outcomes is traditionally studied from an individual perspective. Recently, applying social–ecological models that include socio-economic factors on various social levels is becoming popular. We argue that partners are an important influence on individual h...

A combined experimental and computational investigation of excess molar enthalpies of (nitrobenzene + alkanol) mixtures

International Nuclear Information System (INIS)

Neyband, Razieh Sadat; Zarei, Hosseinali

2015-01-01

Highlights: • Excess molar enthalpies for the binary mixtures of nitrobenzene + alkanols mixtures were measured. • The infinite dilution excess partial molar enthalpies were calculated using the ab initio methods. • The PCM calculations were performed. • The computed excess partial molar enthalpies at infinite dilution were compared to experimental results. - Abstract: Excess molar enthalpies (H m E ) for the binary mixtures of {(nitrobenzene + ethanol), 1-propanol, 2-propanol, 1-butanol and 2-butanol} have been measured over the entire composition range at ambient pressure (81.5 kPa) and temperature 298 K using a Parr 1455 solution calorimeter. From the experimental results, the excess partial molar enthalpies (H i E ) and excess partial molar enthalpies at infinite dilution (H i E,∞ ) were calculated. The excess molar enthalpies (H m E ) are positive for all {nitrobenzene (1) + alkanol (2)} mixtures over the entire composition range. A state-of-the-art computational strategy for the evaluation of excess partial molar enthalpies at infinite dilution was followed at the M05-2X/6-311++G ∗∗ level of theory with the PCM model. The experimental excess partial molar enthalpies at infinite dilution have been compared to the computational data of the ab initio in liquid phase. Integrated experimental and computational results help to clarify the nature of the intermolecular interactions in {nitrobenzene (1) + alkanol (2)} mixtures. The experimental and computational work which was done in this study complements and extends the general research on the computation of excess partial molar enthalpy at infinite dilution of binary mixtures

Limiting excessive postoperative blood transfusion after cardiac procedures. A review.

OpenAIRE

Ferraris, V A; Ferraris, S P

1995-01-01

Analysis of blood product use after cardiac operations reveals that a few patients ( 80%). The risk factors that predispose a minority of patients to excessive blood use include patient-related factors, transfusion practices, drug-related causes, and procedure-related factors. Multivariate studies suggest that patient age and red blood cell volume are independent patient-related variables that predict excessive blood product transfusion aft...

Low-frequency excess flux noise in superconducting devices

Energy Technology Data Exchange (ETDEWEB)

Kempf, Sebastian; Ferring, Anna; Fleischmann, Andreas; Enss, Christian [Kirchhoff-Institute for Physics, Heidelberg University (Germany)

2016-07-01

Low-frequency noise is a rather universal phenomenon and appears in physical, chemical, biological or even economical systems. However, there is often very little known about the underlying processes leading to its occurrence. In particular, the origin of low-frequency excess flux noise in superconducting devices has been an unresolved puzzle for many decades. Its existence limits, for example, the coherence time of superconducting quantum bits or makes high-precision measurements of low-frequency signals using SQUIDs rather challenging. Recent experiments suggest that low-frequency excess flux noise in Josephson junction based devices might be caused by the random reversal of interacting spins in surface layer oxides and in the superconductor-substrate interface. Even if it turns out to be generally correct, the underlying physical processes, i.e. the origin of these spins, their physical nature as well as the interaction mechanisms, have not been resolved so far. In this contribution we discuss recent measurements of low-frequency SQUID noise which we performed to investigate the origin of low-frequency excess flux noise in superconducting devices. Within this context we give an overview of our measurement techniques and link our data with present theoretical models and literature data.

[Natural evolution of excess body weight (overweight and obesity) in children].

Science.gov (United States)

Durá Travé, T; Gallinas Victoriano, F

2013-11-01

To analyze the chronological evolution of excess body weight (overweight and obesity) in order to raise public awareness within the different areas of intervention (family, school, business environment, health services) and to take effective actions. Weight, height and body mass index (BMI) of 604 healthy subjects (307 males and 297 females) have been recorded at birth and at the age of 1, 2, 3, 4, 6, 8, 10, 12 and 14 years. The excess body weight has been calculated according to national references from Ferrández et al. Prevalence of excess body weight at age 14 years was significantly higher (P<.05) in males (29%) than in females (12.8%). BMI (kg/m2) was significantly higher (P<.05) for both sexes in every age period, except for birth and age 1 year, in those patients with excess body weight at age 14, with respect to patients with normal nutritional status of the same age. Those groups with excess body weight at age 14 showed a BMI (Z-score) reaching overweight or obesity levels at age 4, and progressively increasing. Excess body weight probably starts at early stages in life, when dietary habits of the child depends almost exclusively on family habits, and may be aggravated during school attendance. Finally, a disproportionate weight increase occurs in adolescence that is probably related to unhealthy dietary habits and way of life. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Excess air in groundwater as a potential indicator of past environmental changes

International Nuclear Information System (INIS)

Aeschenbach-Hertig, W.; Beyerle, U.; Holocher, J.; Peeters, F.; Kipfer, R.

2002-01-01

Dissolved noble gases in groundwater are used to reconstruct paleotemperature, but also yield information about 'excess air', a component of dissolved gases in excess of solubility equilibrium, derived from dissolution of trapped air in the ground. A good characterization of the excess air component is necessary not only to obtain reliable noble gas temperatures, but also to investigate the potential of excess air as a proxy for past environmental conditions. Two excess air related quantities can be derived from groundwater noble gas data sets: The initial air/water ratio and the pressure exerted on the entrapped air. Under recharge conditions typical for many aquifers, the excess of dissolved gases, expressed by the relative Ne excess ΔNe, is mainly determined by the hydrostatic pressure on the entrapped air. Thus, we suggest that ΔNe is essentially a measure of the amplitude of water table fluctuations in the recharge area. Comparing data sets from three aquifers in temperate, humid latitudes and three aquifers in tropical, semi-arid regions, we find that ΔNe is generally higher in the tropical aquifers, possibly related to larger water table fluctuations in these aquifers characterized by deep unsaturated zones. Whereas ΔNe shows little temporal variation in the mid-latitude aquifers, there is a strong signal of higher ΔNe in the paleowaters of the tropical aquifers as compared to water recharged under modern climate conditions. This finding may indicate a higher variability of recharge in the past at the studied tropical sites. (author)

Management of excessive gingival display: Lip repositioning technique

Directory of Open Access Journals (Sweden)

Upasana Sthapak

2015-01-01

Full Text Available The lips form the frame of a smile and define the esthetic zone. Excessive gingival display during smile is often referred to as "gummy smile". A successful management of excessive gingival display with lip repositioning procedure has shown excellent results. The procedure involves removing a strip of partial thickness mucosa from maxillary vestibule, then suturing it back to the lip mucosa at the level of mucogingival junction. This technique results in restricted muscle pull and a narrow vestibule, thereby reducing the gingival display. In this case gummy smile was treated by modification of Rubinstein and Kostianovsky′s surgical lip repositioning technique which resulted in a harmonious smile.

43 CFR 426.12 - Excess land.

Science.gov (United States)

2010-10-01

... advertise the sale of the property in farm journals and in newspapers within the county in which the land...; (ii) A recordable contract is amended to remove excess land when the landowner's entitlement increases... eligible buyer at a price and on terms approved by Reclamation; (C) The sale from the previous landowner is...

Precision Drell-Yan Measurements at the LHC and Implications for the Diphoton Excess

CERN Document Server

Goertz, Florian; Son, Minho; Urbano, Alfredo

2016-01-01

Precision measurements of the Drell-Yan (DY) cross section at the LHC constrain new physics scenarios that involve new states with electroweak (EW) charges. We analyze these constraints and apply them to models that can address the LHC diphoton excess at 750 GeV. We confront these findings with LEP EW precision tests and show that DY provides stronger constraints than the LEP data. While 8 TeV data can already probe some parts of the interesting region of parameter space, LHC14 results are expected to cover a substantial part of the relevant terrain. We derive the bounds from the existing data, estimate LHC14 reach and compare them to the bounds one gets from LEP and future FCC-ee precision measurements.

The excess in the hate discourse of the haters

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Rebeca Recuero Rebs

2017-11-01

Full Text Available The article aims to identify and comprehend the marks of the excess present in the hate discourse of the haters. By using the power of social media’s information diffusion on the internet, the haters appropriate of such spaces to disseminate ideologies related to violence, intending to generate more hate. Among the strategies utilized by this group, there is the excess. However, it is necessary to understand the subject’s social and historical contexts and the meanings of their discourse in these environments. As the corpus, we start off the analysis from the attacks towards the actress Taís Araújo occurred on Facebook. As shown by the results, the excess is perceived on authority demonstrations, on the repetition of ideals and onto the search of values such as visibility, popularity (among participants of the networks and the media, authority and reputation (inside the hater’s group of belonging.elonging.

Excessive computer game playing: evidence for addiction and aggression?

Science.gov (United States)

Grüsser, S M; Thalemann, R; Griffiths, M D

2007-04-01

Computer games have become an ever-increasing part of many adolescents' day-to-day lives. Coupled with this phenomenon, reports of excessive gaming (computer game playing) denominated as "computer/video game addiction" have been discussed in the popular press as well as in recent scientific research. The aim of the present study was the investigation of the addictive potential of gaming as well as the relationship between excessive gaming and aggressive attitudes and behavior. A sample comprising of 7069 gamers answered two questionnaires online. Data revealed that 11.9% of participants (840 gamers) fulfilled diagnostic criteria of addiction concerning their gaming behavior, while there is only weak evidence for the assumption that aggressive behavior is interrelated with excessive gaming in general. Results of this study contribute to the assumption that also playing games without monetary reward meets criteria of addiction. Hence, an addictive potential of gaming should be taken into consideration regarding prevention and intervention.

Health impacts of Facebook usage and mobile texting among undergraduate dental students: it's time to understand the difference between usage and an excessive use.

Science.gov (United States)

Lee, Y L; Verma, R K; Yadav, H; Barua, A

2016-11-01

Facebook and mobile texting are prevalent in the lives of almost every student. However, little is known about the relationship between Facebook usage or mobile texting and their impacts on health amongst undergraduate dental students. In this study, excessive Facebook use and excessive mobile texting were studied as they relate to impacts on health. A cross-sectional study was conducted at a private university in Malaysia. A total of 188 undergraduate dental students were interviewed using a pre-tested and self-rated questionnaire. Data collected from participants were analysed using SPSS version 18.0. Chi-square test, Fisher's exact test and multiple logistic regression analyses were applied to study the relationship between explanatory variables and excessive Facebook use and excessive mobile texting. The prevalence of excessive Facebook use and excessive mobile texting amongst undergraduate dental students was found to be 33.2% and 33.0%, respectively. According to a multivariate analysis, texting habits, such as the presence of daytime sleepiness after texting late at night (aOR = 2.682, 95% CI = 1.142-6.301) and the presence of anxious feelings if students failed to receive a timely response (aOR = 3.819, 95% CI = 1.580-9.230), were determined to be significant predictors of excessive mobile texting. Excessive Facebook use was found to be significantly related to three variables as follows: fewer numbers of close friends (aOR = 2.275, 95% CI = 1.057-4.898), the checking of updates on the Facebook walls of their friends (aOR = 2.582, 95% CI = 1.189-5.605) and the absence of active and vigorous feelings during Facebook use (aOR = 3.401, 95% CI = 1.233-9.434). Approximately one-third of undergraduate dental students in this study experienced excessive Facebook use and/or excessive mobile texting. Health education and promotion should be instituted to create awareness, whilst students should be advised to practise self-control with respect to

Association between blood cholesterol and sodium intake in hypertensive women with excess weight.

Science.gov (United States)

Padilha, Bruna Merten; Ferreira, Raphaela Costa; Bueno, Nassib Bezerra; Tassitano, Rafael Miranda; Holanda, Lidiana de Souza; Vasconcelos, Sandra Mary Lima; Cabral, Poliana Coelho

2018-04-01

Restricted sodium intake has been recommended for more than 1 century for the treatment of hypertension. However, restriction seems to increase blood cholesterol. In women with excess weight, blood cholesterol may increase even more because of insulin resistance and the high lipolytic activity of adipose tissue.The aim of this study was to assess the association between blood cholesterol and sodium intake in hypertensive women with and without excess weight.This was a cross-sectional study with hypertensive and nondiabetic women aged 20 to 59 years, recruited at the primary healthcare units of Maceio, Alagoas, Brazilian Northeast. Excess weight was defined as body mass index (BMI) ≥25.0 kg/m. Sodium intake was estimated by the 24-hour urinary excretion of sodium. Blood cholesterol was the primary outcome investigated by this study, and its relationship with sodium intake and other variables was assessed by Pearson correlation and multivariate linear regression using a significance level of 5%.This study included 165 hypertensive women. Of these, 135 (81.8%) were with excess weight. The mean sodium intake was 3.7 g (±1.9) and 3.4 g (±2.4) in hypertensive women with and without excess weight, respectively. The multiple normal linear regression models fitted to the "blood cholesterol" in the 2 groups reveal that for the group of hypertensive women without excess weight only 1 independent variable "age" is statistically significant to explain the variability of the blood cholesterol levels. However, for the group of hypertensive women with excess weight, 2 independent variables, age and sodium intake, can statistically explain variations of the blood cholesterol levels.Blood cholesterol is statistically inversely related to sodium intake for hypertensive women with excess weight, but it is not statistically related to sodium intake for hypertensive women without excess weight.

Stringy origin of diboson and dijet excesses at the LHC

Science.gov (United States)

Anchordoqui, Luis A.; Antoniadis, Ignatios; Goldberg, Haim; Huang, Xing; Lüst, Dieter; Taylor, Tomasz R.

2015-10-01

Very recently, the ATLAS and CMS Collaborations reported diboson and dijet excesses above standard model expectations in the invariant mass region of 1.8-2.0 TeV. Interpreting the diboson excess of events in a model independent fashion suggests that the vector boson pair production searches are best described by WZ or ZZ topologies, because states decaying into W+W- pairs are strongly constrained by semileptonic searches. Under the assumption of a low string scale, we show that both the diboson and dijet excesses can be steered by an anomalous U (1) field with very small coupling to leptons. The Drell-Yan bounds are then readily avoided because of the leptophobic nature of the massive Z‧ gauge boson. The non-negligible decay into ZZ required to accommodate the data is a characteristic footprint of intersecting D-brane models, wherein the Landau-Yang theorem can be evaded by anomaly-induced operators involving a longitudinal Z. The model presented herein can be viewed purely field-theoretically, although it is particularly well motivated from string theory. Should the excesses become statistically significant at the LHC13, the associated Zγ topology would become a signature consistent only with a stringy origin.

MAGNETIC GRAIN TRAPPING AND THE HOT EXCESSES AROUND EARLY-TYPE STARS

Energy Technology Data Exchange (ETDEWEB)

Rieke, G. H.; Gáspár, András; Ballering, N. P., E-mail: grieke@as.arizona.edu, E-mail: agaspar@as.arizona.edu, E-mail: ballerin@email.arizona.edu [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States)

2016-01-10

A significant fraction of main sequence stars observed interferometrically in the near-infrared have slightly extended components that have been attributed to very hot dust. To match the spectrum appears to require the presence of large numbers of very small (<200 nm in radius) dust grains. However, particularly for the hotter stars, it has been unclear how such grains can be retained close to the star against radiation pressure force. We find that the expected weak stellar magnetic fields are sufficient to trap nm-sized dust grains in epicyclic orbits for a few weeks or longer, sufficient to account for the hot excess emission. Our models provide a natural explanation for the requirement that the hot excess dust grains be smaller than 200 nm. They also suggest that magnetic trapping is more effective for rapidly rotating stars, consistent with the average vsini measurements of stars with hot excesses being larger (at ∼2σ) than those for stars without such excesses.

Altered cardiorespiratory coupling in young male adults with excessive online gaming.

Science.gov (United States)

Chang, Jae Seung; Kim, Eun Young; Jung, Dooyoung; Jeong, Seong Hoon; Kim, Yeni; Roh, Myoung-Sun; Ahn, Yong Min; Hahm, Bong-Jin

2015-09-01

This study aimed to investigate changes in heart rate variability and cardiorespiratory coupling in male college students with problematic Internet use (PIU) excessive gaming type during action video game play to assess the relationship between PIU tendency and central autonomic regulation. Electrocardiograms and respiration were simultaneously recorded from 22 male participants with excessive online gaming and 22 controls during action video game play. Sample entropy (SampEn) was computed to assess autonomic regularity, and cross-SampEn was calculated to quantify autonomic coordination. During video game play, reduced cardiorespiratory coupling (CRC) was observed in individuals with PIU excessive gaming type compared with controls, implicating central autonomic dysregulation. The PIU tendency was associated with the severity of autonomic dysregulation. These findings indicate impaired CRC in PIU excessive gaming type, which may reflect alterations of central inhibitory control over autonomic responses to pleasurable online stimuli. Copyright © 2015 Elsevier B.V. All rights reserved.

Economic analysis of using excess renewable electricity to displace heating fuels

DEFF Research Database (Denmark)

Pensini, Alessandro; Rasmussen, Claus Nygaard; Kempton, Willett

2014-01-01

. Because excess electricity appears to be cost-optimum, this raises the question as to whether the excess electricity, which in the case of wind power is predominately produced in colder weather, might displace other fuels for purposes such as heat. This study models using excess electricity for heating......, based on an analysis of electricity and heat use in a TSO in the North-Eastern part of the United States (PJM Interconnection). The heating system was modeled as heat pump based district heating (HPDH) with thermal energy storage (TES). Thus, excess electricity is transformed into heat, which is easy....... An algorithm that calculates the total cost of a unit of heat was used to determine the economically optimal size of the system’s main components and the influence that natural gas (NG) and electricity prices have on this optimum. It was found that a system based on heat pumps (HP) and centralized thermal...

On the observed excess of retrograde orbits among long-period comets

International Nuclear Information System (INIS)

Fernandez, J.A.

1981-01-01

The distribution of orbital inclinations of the observed long-period comets is analysed. An excess of retrograde orbits is found which increases with the perihelion distance, except for the range 1.1 10 3 A U) has the same behaviour as the total sample. It is thus suggested that the excess of retrograde orbits among long-period comets is related to an already existent excess among the incoming new comets (i.e. comets driven into the planetary region by stellar perturbations). Using theoretical considerations and a numerical model it is proposed that an important fraction of the so-called new comets are actually repeating passages through the planetary region. Nearly a half of the new comets with q > 2 A U may be repeating passages. An important consequence of the presence of comets repeating passages among the new ones is the production of an excess of retrograde orbits in the whole sample. (author)

Separation of V(V)-4-(2-pyridylazo)resorcinolato complex from a large excess reagent using an ODS cartridge for high-performance liquid chromatography.

Science.gov (United States)

Takahashi, Toru; Kaneko, Emiko; Yotsuyanagi, Takao

2006-12-01

A selective off-line preconcentration technique for the V(V) complex with 4-(2-pyridylazo)resorcinol has been developed and successfully applied to the determination of V(V) in an air-borne sample. The target complex was separated from excess reagent using an ODS cartridge and water as the eluent. The complex was then concentrated on another ODS cartridge using tetrabutylammonium bromide and eluted with methanol; the eluate was applied to a one-drop concentration/HPLC. A detection limit as low as (6.05 +/- 0.82)x 10(-11) M (5 ppt) was achieved.

Excess mortality during the warm summer of 2015 in Switzerland.

Science.gov (United States)

Vicedo-Cabrera, Ana M; Ragettli, Martina S; Schindler, Christian; Röösli, Martin

2016-01-01

In Switzerland, summer 2015 was the second warmest summer for 150 years (after summer 2003). For summer 2003, a 6.9% excess mortality was estimated for Switzerland, which corresponded to 975 extra deaths. The impact of the heat in summer 2015 in Switzerland has not so far been evaluated. Daily age group-, gender- and region-specific all-cause excess mortality during summer (June-August) 2015 was estimated, based on predictions derived from quasi-Poisson regression models fitted to the daily mortality data for the 10 previous years. Estimates of excess mortality were derived for 1 June to 31 August, at national and regional level, as well as by month and for specific heat episodes identified in summer 2015 by use of seven different definitions. 804 excess deaths (5.4%, 95% confidence interval [CI] 3.0‒7.9%) were estimated for summer 2015 compared with previous summers, with the highest percentage obtained for July (11.6%, 95% CI 3.7‒19.4%). Seventy-seven percent of deaths occurred in people aged 75 years and older. Ticino (10.3%, 95% CI -1.8‒22.4%), Northwestern Switzerland (9.5%, 95% CI 2.7‒16.3%) and Espace Mittelland (8.9%, 95% CI 3.7‒14.1%) showed highest excess mortality during this three-month period, whereas fewer deaths than expected (-3.3%, 95% CI -9.2‒2.6%) were observed in Eastern Switzerland, the coldest region. The largest excess estimate of 23.7% was obtained during days when both maximum apparent and minimum night-time temperature reached extreme values (+32 and +20 °C, respectively), with 31.0% extra deaths for periods of three days or more. Heat during summer 2015 was associated with an increase in mortality in the warmer regions of Switzerland and it mainly affected older people. Estimates for 2015 were only a little lower compared to those of summer 2003, indicating that mitigation measures to prevent heat-related mortality in Switzerland have not become noticeably effective in the last 10 years.

Ethical implications of excessive cluster sizes in cluster randomised trials.

Science.gov (United States)

Hemming, Karla; Taljaard, Monica; Forbes, Gordon; Eldridge, Sandra M; Weijer, Charles

2018-02-20

The cluster randomised trial (CRT) is commonly used in healthcare research. It is the gold-standard study design for evaluating healthcare policy interventions. A key characteristic of this design is that as more participants are included, in a fixed number of clusters, the increase in achievable power will level off. CRTs with cluster sizes that exceed the point of levelling-off will have excessive numbers of participants, even if they do not achieve nominal levels of power. Excessively large cluster sizes may have ethical implications due to exposing trial participants unnecessarily to the burdens of both participating in the trial and the potential risks of harm associated with the intervention. We explore these issues through the use of two case studies. Where data are routinely collected, available at minimum cost and the intervention poses low risk, the ethical implications of excessively large cluster sizes are likely to be low (case study 1). However, to maximise the social benefit of the study, identification of excessive cluster sizes can allow for prespecified and fully powered secondary analyses. In the second case study, while there is no burden through trial participation (because the outcome data are routinely collected and non-identifiable), the intervention might be considered to pose some indirect risk to patients and risks to the healthcare workers. In this case study it is therefore important that the inclusion of excessively large cluster sizes is justifiable on other grounds (perhaps to show sustainability). In any randomised controlled trial, including evaluations of health policy interventions, it is important to minimise the burdens and risks to participants. Funders, researchers and research ethics committees should be aware of the ethical issues of excessively large cluster sizes in cluster trials. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is

Effects on enantiomeric drug disposition and open-field behavior after chronic treatment with venlafaxine in the P-glycoprotein knockout mice model.

Science.gov (United States)

Karlsson, Louise; Hiemke, Christoph; Carlsson, Björn; Josefsson, Martin; Ahlner, Johan; Bengtsson, Finn; Schmitt, Ulrich; Kugelberg, Fredrik C

2011-05-01

P-glycoprotein (P-gp) plays an important role in the efflux of drugs from the brain back into the bloodstream and can influence the pharmacokinetics and pharmacodynamics of drug molecules. To our knowledge, no studies have reported pharmacodynamic effects of any antidepressant drug in the P-gp knockout mice model. The aim of this study was to investigate the enantiomeric venlafaxine and metabolite concentrations in serum and brain of abcb1ab⁻/⁻ mice compared to wild-type mice upon chronic dosing, and to assess the effect of venlafaxine treatment on open-field behavior. P-gp knockout and wild-type mice received two daily intraperitoneal injections of venlafaxine (10 mg/kg) over ten consecutive days. Locomotor and rearing activities were assessed on days 7 and 9. After 10 days, drug and metabolite concentrations in brain and serum were determined using an enantioselective LC/MS/MS method. The brain concentrations of venlafaxine and its three demethylated metabolites were two to four times higher in abcb1ab⁻/⁻ mice compared to abcb1ab+/+ mice. The behavioral results indicated an impact on exploration-related behaviors in the open-field as center activity was increased, and rears were decreased by venlafaxine treatment. Our results show that P-gp at the blood-brain barrier plays an important role in limiting brain entry of the enantiomers of venlafaxine and its metabolites after chronic dosing. Taken together, the present pharmacokinetic and pharmacodynamic findings offer the possibility that the expression of P-gp in patients may be a contributing factor for limited treatment response.

ILLUSION OF EXCESSIVE CONSUMPTION AND ITS EFFECTS

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MUNGIU-PUPĂZAN MARIANA CLAUDIA

2015-12-01

Full Text Available The aim is to explore, explain and describe this phenomenon to a better understanding of it and also the relationship between advertising and the consumer society members. This paper aims to present an analysis of excessive and unsustainable consumption, the evolution of a phenomenon, and the ability to find a way to combat. Unfortunately, studies show that this tendency to accumulate more than we need to consume excess means that almost all civilizations fined and placed dogmatic among the values that children learn early in life. This has been perpetuated since the time when the goods or products does not get so easy as today. Anti-consumerism has emerged in response to this economic system, not on the long term. We are witnessing the last two decades to establish a new phase of consumer capitalism: society hiperconsumtion.

Characterising the 750 GeV diphoton excess

International Nuclear Information System (INIS)

Bernon, Jérémy; Goudelis, Andreas; Kraml, Sabine; Mawatari, Kentarou; Sengupta, Dipan

2016-01-01

We study kinematic distributions that may help characterise the recently observed excess in diphoton events at 750 GeV at the LHC Run 2. Several scenarios are considered, including spin-0 and spin-2 750 GeV resonances that decay directly into photon pairs as well as heavier parent resonances that undergo three-body or cascade decays. We find that combinations of the distributions of the diphoton system and the leading photon can distinguish the topology and mass spectra of the different scenarios, while patterns of QCD radiation can help differentiate the production mechanisms. Moreover, missing energy is a powerful discriminator for the heavy parent scenarios if they involve (effectively) invisible particles. While our study concentrates on the current excess at 750 GeV, the analysis is general and can also be useful for characterising other potential diphoton signals in the future.

Excess molar volumes of binary mixtures (an ionic liquid + water): A review

International Nuclear Information System (INIS)

Bahadur, Indra; Letcher, Trevor M.; Singh, Sangeeta; Redhi, Gan G.; Venkatesu, Pannuru; Ramjugernath, Deresh

2015-01-01

Highlights: • Review of excess molar volumes for mixtures of (ionic liquids (ILs) + H 2 O). • 6 cation groups reviewed including imidazolium and pyrrolidinium groups. • 13 anions reviewed including tetraborate, triflate, and hydrogensulphate. • Effects of anion, cation, and temperature investigated. - Abstract: This review covers recent developments in the area of excess molar volumes for mixtures of {ILs (1) + H 2 O (2)} where ILs refers to ionic liquids involving cations: imidazolium, pyridinium, pyrrolidinium, piperidinium, morpholinium and ammonium groups; and anions: tetraborate, triflate, hydrogensulphate, methylsulphate, ethylsulphate, thiocyanate, dicyanamide, octanate, acetate, nitrate, chloride, bromide, and iodine. The excess molar volumes of aqueous ILs were found to cover a wide range of values for the different ILs (ranging from −1.7 cm 3 · mol −1 to 1.2 cm 3 · mol −1 ). The excess molar volumes increased with increasing temperature for all systems studied in this review. The magnitude and in some cases the sign of the excess molar volumes for all the aqueous ILs mixtures, apart from the ammonium ILs, were very dependent on temperature. This was particularly important in the dilute IL concentration region. It was found that the sign and magnitude of the excess molar volumes of aqueous ILs (for ILs with hydrophobic cations), was more dependent on the nature of the anion than on the cation

Risk Factors for Excessive Gestational Weight Gain in a Healthy, Nulliparous Cohort

Directory of Open Access Journals (Sweden)

Antonia Restall

2014-01-01

Full Text Available Objective. Excessive gestational weight gain (GWG is associated with adverse maternal and child outcomes and contributes to obesity in women. Our aim was to identify early pregnancy factors associated with excessive GWG, in a contemporary nulliparous cohort. Methods. Participants in the SCOPE study were classified into GWG categories (“not excessive” versus “excessive” based on pregravid body mass index (BMI using 2009 Institute of Medicine (IOM guidelines. Maternal characteristics and pregnancy risk factors at 14–16 weeks were compared between categories and multivariable analysis controlled for confounding factors. Results. Of 1950 women, 17% gained weight within the recommended range, 74% had excessive and 9% inadequate GWG. Women with excessive GWG were more likely to be overweight (adjOR 2.9 (95% CI 2.2–3.8 or obese (adjOR 2.5 (95% CI 1.8–3.5 before pregnancy compared to women with a normal BMI. Other factors independently associated with excessive GWG included recruitment in Ireland, younger maternal age, increasing maternal birthweight, cessation of smoking by 14–16 weeks, increased nightly sleep duration, high seafood diet, recent immigrant, limiting behaviour, and decreasing exercise by 14–16 weeks. Fertility treatment was protective. Conclusions. Identification of potentially modifiable risk factors for excessive GWG provides opportunities for intervention studies to improve pregnancy outcome and prevent maternal obesity.

Analytical estimation of control rod shadowing effect for excess reactivity measurement of HTTR

International Nuclear Information System (INIS)

Nakano, Masaaki; Fujimoto, Nozomu; Yamashita, Kiyonobu

1999-01-01

The fuel addition method is generally used for the excess reactivity measurement of the initial core. The control rod shadowing effect for the excess reactivity measurement has been estimated analytically for High Temperature Engineering Test Reactor (HTTR). 3-dimensional whole core analyses were carried out. The movements of control rods in measurements were simulated in the calculation. It was made clear that the value of excess reactivity strongly depend on combinations of measuring control rods and compensating control rods. The differences in excess reactivity between combinations come from the control rod shadowing effect. The shadowing effect is reduced by the use of plural number of measuring and compensating control rods to prevent deep insertion of them into the core. The measured excess reactivity in the experiments is, however, smaller than the estimated value with shadowing effect. (author)

Occurrence, enantiomeric signature and ecotoxicological risk assessment of HCH isomers and DDT metabolites in the sediments of Kabul River, Pakistan.

Science.gov (United States)

Aamir, Muhammad; Khan, Sardar; Niu, Lili; Zhu, Siyu; Khan, Anwarzeb

2017-08-01

Hexachlorocyclohexane (HCH) isomers and dichlorodiphenyltrichloroethane (DDT) metabolites were analyzed in sediments of three different depths (0-10, 10-20 and 20-30 cm) collected from Kabul River, Pakistan, in February 2014. The occurrence levels, enantiomer fractions and potential ecological risk of these organochlorine pesticides (OCPs) were evaluated. The total concentrations of ∑HCHs and ∑DDTs in surface sediments ranged from 4.9-23.9 ng g -1 and from 6.4-18.8 ng g -1 (dry weight basis), respectively. The vertical contamination profile of DDTs was found in order of 20-30 cm >10-20 cm >0-10 cm, indicated that the residue levels of DDTs gradually decreased after it was banned. The ratios of β-HCH/HCHs ranged from 0.04 to 0.73 (69 % of samples below 0.5) suggesting the fresh input of HCHs, while isomeric ratios of α-HCH/γ-HCH (ranged from 0.02 to 7.94), with 76 % of samples less than 3, indicating the cocktail use of technical grade HCH and lindane in the study area. The ratio of (DDE + DDD)/DDTs (ranged from 0.42 to 0.90) indicated long-term biodegradation of parent DDT. The enantiomer of α-HCH was generally racemic or close to racemic for most of the samples, with enantiomeric fraction (EF) value DDT the EF values >0.5 indicated the depletion of (-)-o,p'-DDT enantiomer in most of the samples. According to sediment quality guidelines (SQGs), HCH contamination is the main concern for ecotoxicological risk in Kabul River.

Involvement of apoptosis and autophagy in the death of RPMI 8226 multiple myeloma cells by two enantiomeric sigma receptor ligands.

Science.gov (United States)

Korpis, Katharina; Weber, Frauke; Brune, Stefanie; Wünsch, Bernhard; Bednarski, Patrick J

2014-01-01

Over-expression of σ receptors by many tumor cell lines makes ligands for these receptors attractive as potential chemotherapeutic drugs. Enantiomeric piperazines (S)-4 and (R)-4 were prepared as potential σ-receptor ligands in a chiral pool synthesis starting from (S)- and (R)-aspartate. Both compounds showed high affinities for the σ₁ and σ₂ receptors. In the human multiple myeloma cell line RPMI 8226, a line expressing high levels of σ receptors, both compounds inhibited cell proliferation with IC₅₀ values in the low μM range. No chiral differentiation between either the σ receptor binding affinity or the cytotoxicity of the two enantiomers was observed. Both compounds induced apoptosis, which was evidenced by nuclear condensation, binding of annexin-V to phosphatidylserine in the outer leaf of the cell membrane, cleavage products of poly(ADP-ribose) polymerase-1 (PARP-1) and caspase-8 as well as the expression of bcl₂ family members bax, bad and bid. However, apoptosis appeared to be caspase independent. Increased levels of the phosphorylated form of the microtubule associated protein light chain 3-II (LC3-II), an autophagosome marker, gave evidence that both compounds induced autophagy. However, further data (e.g., treatment with wortmannin) indicate that autophagy is incomplete and not cytoprotective. Lipid peroxidation (LPO) was observed in RPMI 8226 cells treated with the two compounds, and the lipid antioxidant α-tocopherol attenuated LPO. Interestingly, α-tocopherol reduced significantly both apoptosis and autophagy induced by the compounds. These results provide evidence that, by initiating LPO and changes in mitochondrial membrane potential, both compounds induce apoptosis and autophagy in RPMI 8226 cells. Copyright © 2013 Elsevier Ltd. All rights reserved.

Dictating photoreactivity through restricted bond rotations: cross-photoaddition of atropisomeric acrylimide derivatives under UV/visible-light irradiation.

Science.gov (United States)

Iyer, Akila; Jockusch, Steffen; Sivaguru, J

2014-11-13

Nonbiaryl atropisomeric acrylimides underwent facile [2 + 2] photocycloaddition leading to cross-cyclobutane adducts with very high stereospecificity (enantiomeric excess (ee): 99% and diastereomeric excess (de): 99%). The photoreactions proceeded smoothly in isotropic media for both direct and triplet sensitized irradiations. The reactions were also found to be very efficient in the solid state where the same cross-cyclobutane adduct was observed. Photophysical studies enabled us to understand the excited-state photochemistry of acrylimides. The triplet energy was found to be ∼63 kcal/mol. The reactions proceeded predominantly via a singlet excited state upon direct irradiation with very poor intersystem crossing that was ascertained by quantification of the generated singlet oxygen. The reactions progressed smoothly with triplet sensitization with UV or visible-light irradiations. Laser flash photolysis experiments established the triplet transient of atropisomeric acrylimides with a triplet lifetime at room temperature of ∼40 ns.

Distribution of enantiomers of volatile organic compounds in selected fruit distillates.

Science.gov (United States)

Vyviurska, Olga; Zvrškovcová, Helena; Špánik, Ivan

2017-01-01

The enantiomer ratios of chiral volatile organic compounds in fruit distillates were determined by multidimensional gas chromatography using solid-phase microextraction (SPME) as a sample treatment procedure. Linalool and its oxides, limonene, α-terpineol, and nerolidol, were present at the highest concentration levels, while significantly lower amounts of β-citronellol and lactones were found in the studied samples. However, almost all terpenoids mainly occur as a racemic or near-racemic mixture; enantiomer distribution of some chiral organic compounds in fruit distillates correlated to a botanical origin. In particular, a significant enantiomeric excess of (R)-linalool and (S)-α-terpineol was found only for pear brandy, and likewise the dominance (R)-limonene and the second eluted enantiomer of nerolidol for Sorbus domestica and strawberry, respectively. The distribution of γ-lactones stereoisomers was more nonspecific, with a general excess of the R-enantiomer. © 2016 Wiley Periodicals, Inc.

Using daily excessive concentration hours to explore the short-term mortality effects of ambient PM2.5 in Hong Kong

International Nuclear Information System (INIS)

Lin, Hualiang; Ma, Wenjun; Qiu, Hong; Wang, Xiaojie; Trevathan, Edwin; Yao, Zhenjiang; Dong, Guang-Hui; Vaughn, Michael G.; Qian, Zhengmin; Tian, Linwei

2017-01-01

We developed a novel indicator, daily excessive concentration hours (DECH), to explore the acute mortality impacts of ambient fine particulate matter pollution (PM 2.5 ) in Hong Kong. The DECH of PM 2.5 was calculated as daily concentration-hours >25 μg/m 3 . We applied a generalized additive models to quantify the association between DECH and mortality with adjustment for potential confounders. The results showed that the DECH was significantly associated with mortality. The excess mortality risk for an interquartile range (565 μg/m 3 *hours) increase in DECH of PM 2.5 was 1.65% (95% CI: 1.05%, 2.26%) for all natural mortality at lag 02 day, 2.01% (95% CI: 0.82%, 3.21%) for cardiovascular mortality at lag 03 days, and 1.41% (95% CI: 0.34%, 2.49%) for respiratory mortality at lag 2 day. The associations remained consistent after adjustment for gaseous air pollutants (daily mean concentration of SO 2 , NO 2 and O 3 ) and in alternative model specifications. When compared to the mortality burden of daily mean PM 2.5 , DECH was found to be a relatively conservative indicator. This study adds to the evidence by showing that daily excessive concentration hours of PM 2.5 might be a new predictor of mortality in Hong Kong. - Highlights: • A new indicator, daily excess concentration hours (DECH), was proposed in this study. • DECH of PM 2.5 was associated with cardiovascular mortality in Hong Kong. • DECH of PM 2.5 was associated with respiratory mortality in Hong Kong. - Excessive concentration hours of PM 2.5 , as one new indicator, is significantly associated with increased mortality in Hong Kong.

[Impact on the development of parental awareness of excess weight in children].

Science.gov (United States)

Łupińska, Anna; Chlebna-Sokół, Danuta

2015-04-01

A lot of publications emphasize the special role of parents' eating habits and their lifestyle on the prevalence of excess body weight in children. The aim of this study was to answer the question whether parents of children who are overweight and obese are aware of this problem and what factors affect their perception of the excess body weight degree in their offspring. The study included 137 children aged 6,5- 13,5 years. 23 respondents were overweight and 76 obese. Compared group consisted of 113 children. All patients underwent physical examination with anthropometric measurements. Parents were asked to complete a questionnaire, where they evaluated the degree of excess body weight of their child. We also asked about both parents' weight and body height, their education and chronic diseases occurring in the family. In the group of obese children 56.2% of the respondents came from families where one parent had excess body weight while 32.9% of them from families where this problem affected both parents. In 51.3% of patients with a body mass index (BMI) above 95 centil, parents wrongly assessed the degree of excess body weight of their child, in overweight group this proportion accounted for 8.7%. There was a statistically significant (p = 0.007) correlation between the degree of children's excess body weight and the ability of parents to estimate that. Parents' education had no influence on the incidence of excess body weight in children and their ability to determine its extent. In the group of obese and overweight children only 4% of parents recognized obesity as a chronic disease. Parents of children who are overweight and obese have lower awareness about their child's weight in comparison to parents of children with normal weight. There is a statistical correlation between parents' perception of excess body weight and the development of obesity in children. © 2015 MEDPRESS.

Applied medical image processing a basic course

CERN Document Server

Birkfellner, Wolfgang

2014-01-01

A widely used, classroom-tested text, Applied Medical Image Processing: A Basic Course delivers an ideal introduction to image processing in medicine, emphasizing the clinical relevance and special requirements of the field. Avoiding excessive mathematical formalisms, the book presents key principles by implementing algorithms from scratch and using simple MATLAB®/Octave scripts with image data and illustrations on an accompanying CD-ROM or companion website. Organized as a complete textbook, it provides an overview of the physics of medical image processing and discusses image formats and data storage, intensity transforms, filtering of images and applications of the Fourier transform, three-dimensional spatial transforms, volume rendering, image registration, and tomographic reconstruction.

Real exchange rate persistence and the excess return puzzle

DEFF Research Database (Denmark)

Juselius, Katarina; Assenmacher, Katrin

2017-01-01

The PPP puzzle refers to the wide swings of nominal exchange rates around their long-run equilibrium values whereas the excess return puzzle represents the persistent deviation of the domestic-foreign interest rate differential from the expected change in the nominal exchange rate. Using the I(2......) cointegrated VAR model, much of the excess return puzzle disappears when an uncertainty premium in the foreign exchange market, proxied by the persistent PPP gap, is introduced. Self-reinforcing feedback mechanisms seem to cause the persistence in the Swiss-US parity conditions. These results support imperfect...

Abnormal excess heat observed during Mizuno-type experiments

International Nuclear Information System (INIS)

Fauvarque, Jean-Francois; Clauzon, Pierre Paul; Lalleve, Gerard Jean-Michel

2006-01-01

A simple calorimeter has been designed that works at constant temperature; that of boiling water. Heat Losses can be estimated accurately with an ohmic heater. As expected, losses are independent of the electric power input to the heater and the amount of evaporated water is linearly dependant on the power input. The device has been used to determine the heating power of a plasma electrolysis (the Ohmori-Mizuno experiment). We confirm that in this experiment, the heat output from electrolysis is greater than the electrical power input. The excess energy increases as the electrolysis voltage is increased from 200 up to 350 V (400 V input). The excess energy may be as high as 120 W. (author)

ATLAS diboson excesses from the stealth doublet model

Directory of Open Access Journals (Sweden)

Wei Chao

2016-02-01

Full Text Available The ATLAS Collaboration has reported excesses in diboson invariant mass searches of new resonances around 2 TeV, which might be a prediction of new physics around that mass range. We interpret these results in the context of a modified stealth doublet model where the extra Higgs doublet has a Yukawa interaction with the first generation quarks, and show that the heavy CP-even Higgs boson can naturally explain the excesses in the WW and ZZ channels with a small Yukawa coupling, ξ∼0.15, and a tiny mixing angle with the SM Higgs boson, α∼0.05. Furthermore, the model satisfies constraints from colliders and electroweak precision measurements.

Authenticity of aroma components Enantiomeric separation and compound specific stable isotope analysis

DEFF Research Database (Denmark)

Hansen, Anne-Mette Sølvbjerg

of both enantiomers contrary to natural aromas where often only one of the enantiomers will be in excess. Consequently, if equal amounts of enantiomers are detected in a food product labelled “Natural” it could be an indication of adulteration. Artificial aroma compounds often have very different ratios......The word “authenticity” is increasingly used in the marketing of food products. A product can be marketed claiming its authenticity such as containing only natural ingredients or originating from a special location produced using local traditional production methods. Within the area of food...... ingredients a problem with authenticity of aroma compounds has occurred, because natural aromas are wholly or partly replaced with synthetic ones. This is a large economic problem, since natural aromas are often more expensive than artificial ones. Furthermore, the European Union has legal requirements...

Applicability study of deuterium excess in bottled water life cycle analyses

Directory of Open Access Journals (Sweden)

Mihael Brenčič

2014-12-01

Full Text Available Paper explores the possible use of d‑excess in the investigation of bottled water. Based on the data set from Brencic and Vreca’s paper (2006. Identification of sources and production processes of bottled waters by stable hydrogen and oxygen isotope ratios, d‑excess values were statistically analysed and compared among different bottled water groups and different bottlers. The bottled water life cycle in relation to d‑excess values was also theoretically identified. Descriptive statistics and one-way ANOVA showed no significant differences among the groups. Differences were detected in the shape of empirical distributions. Groups of still and flavoured waters have similar shapes, but sparkling waters differed to the others. Two distinctive groups of bottlers could be discerned. The first group is represented by bottlers with a high range of d‑excess (from 7.7 ‰ to 18.6 ‰ with average of 12.0 ‰ exploring waters originating from the aquifers rich in highly mineralised groundwater and relatively high concentrations of CO2 gas. The second group is represented by bottlers using groundwater from relatively shallow aquifers. Their d‑excess values have characteristics similar to the local precipitation (from 7.8 ‰ to 14.3 ‰ with average of 10.3 ‰. More frequent sampling and better knowledge of production phases are needed to improve usage of isotope fingerprint for authentication of bottled waters.

Background model systematics for the Fermi GeV excess

Energy Technology Data Exchange (ETDEWEB)

Calore, Francesca; Cholis, Ilias; Weniger, Christoph

2015-03-01

The possible gamma-ray excess in the inner Galaxy and the Galactic center (GC) suggested by Fermi-LAT observations has triggered a large number of studies. It has been interpreted as a variety of different phenomena such as a signal from WIMP dark matter annihilation, gamma-ray emission from a population of millisecond pulsars, or emission from cosmic rays injected in a sequence of burst-like events or continuously at the GC. We present the first comprehensive study of model systematics coming from the Galactic diffuse emission in the inner part of our Galaxy and their impact on the inferred properties of the excess emission at Galactic latitudes 2° < |b| < 20° and 300 MeV to 500 GeV. We study both theoretical and empirical model systematics, which we deduce from a large range of Galactic diffuse emission models and a principal component analysis of residuals in numerous test regions along the Galactic plane. We show that the hypothesis of an extended spherical excess emission with a uniform energy spectrum is compatible with the Fermi-LAT data in our region of interest at 95% CL. Assuming that this excess is the extended counterpart of the one seen in the inner few degrees of the Galaxy, we derive a lower limit of 10.0° (95% CL) on its extension away from the GC. We show that, in light of the large correlated uncertainties that affect the subtraction of the Galactic diffuse emission in the relevant regions, the energy spectrum of the excess is equally compatible with both a simple broken power-law of break energy E(break) = 2.1 ± 0.2 GeV, and with spectra predicted by the self-annihilation of dark matter, implying in the case of bar bb final states a dark matter mass of m(χ)=49(+6.4)(-)(5.4)  GeV.

Effects of excess dietary tyrosine or certain xenobiotics on the cholesterogenesis in rats

International Nuclear Information System (INIS)

Nagaoka, S.; Masaki, H.; Aoyama, Y.; Yoshida, A.

1986-01-01

Comparison of the effects of excess dietary tyrosine, DDT, chlorobutanol (Chloretone) or butylated hydroxyanisole (BHA) on serum cholesterol, hepatic activities of the rate-limiting enzyme of cholesterol synthesis,3-hydroxy-3-methylglutaryl coenzyme A reductase and in vivo rates of the hepatic cholesterol synthesis measured by 3 H 2 O incorporation were investigated in rats. Serum cholesterol concentration was significantly higher in rats fed the DDT, chlorobutanol, BHA or excess tyrosine diets than in rats fed the control diet for 7 days. Serum cholesterol concentration remained higher compared to control rats when excess tyrosine was fed for 21 d. When rats were fed a basal diet after feeding a tyrosine excess diet for 2 wk, liver weight and serum cholesterol level returned to normal within 7 d. The incorporation of 3 H 2 O into liver cholesterol and the activity of liver 3-hydroxy-3-methylglutaryl coenzyme A reductase were greater in rats fed excess tyrosine or certain xenobiotics than in control rats. Present results suggested that the increase in serum cholesterol concentration due to excess dietary tyrosine or certain xenobiotics is mainly attributable to the stimulation of liver cholesterol synthesis

Field experiment on excess air formation in the riverbank of Danube

International Nuclear Information System (INIS)

Palcsu, L.; Major, Z.; Aeschbach-Hertig, W.

2007-01-01

Complete text of publication follows. Excess air is a contribution to the gases dissolved in groundwater in addition to the solubility equilibrium component, formed by partial or total dissolution of air trapped during water level rises in the unsaturated zone. The amount of excess air can be quite large, mainly if the water level increase is significant. The first aim of this field experiment carried out in September 2007 during a flood (Fig. 1/b) occurred along the Danube River has been to demonstrate that the excess air formation can be detected and studied under natural conditions when the groundwater level is rising. The study site is located in the riverbank of Danube River, the dug-well is at around 30 m from the riverbed (Fig. 1/a). The whole area is composed of fluvial sand. Separated water samples can be taken from the sampling tubes. Each sampling tube represents a certain depth. The horizontal groundwater flow velocity is supposed to be around 10 m/day (or at least this magnitude), that of course depends on the level difference between Danube and the groundwater. Helium and neon concentrations have been measured from the water samples. What we can see from these noble gas data is a probable correlation between groundwater level and excess noble gas concentrations. He and Ne are correlating providing evidence that the excess components are of same origin. However, the helium excess is usually larger than that of neon that means there has to be non atmospheric components of helium, such as terrigenic and tritiogenic. The R/Ra ratios are generally higher than one clearly showing tritiogenic 3 He in the water. Having a look at Fig. 1/b-c, it can be observed that there is a relatively good relation between groundwater rising and the excesses of the noble gases. From this sampling campaign, we can conclude that this kind of field experiment does make sense. Further noble gases have to be measured, and more information has to be gained regarding to the local

Excess electrons in methanol clusters: Beyond the one-electron picture

Science.gov (United States)

Pohl, Gábor; Mones, Letif; Turi, László

2016-10-01

We performed a series of comparative quantum chemical calculations on various size negatively charged methanol clusters, ("separators=" CH 3 OH ) n - . The clusters are examined in their optimized geometries (n = 2-4), and in geometries taken from mixed quantum-classical molecular dynamics simulations at finite temperature (n = 2-128). These latter structures model potential electron binding sites in methanol clusters and in bulk methanol. In particular, we compute the vertical detachment energy (VDE) of an excess electron from increasing size methanol cluster anions using quantum chemical computations at various levels of theory including a one-electron pseudopotential model, several density functional theory (DFT) based methods, MP2 and coupled-cluster CCSD(T) calculations. The results suggest that at least four methanol molecules are needed to bind an excess electron on a hydrogen bonded methanol chain in a dipole bound state. Larger methanol clusters are able to form stronger interactions with an excess electron. The two simulated excess electron binding motifs in methanol clusters, interior and surface states, correlate well with distinct, experimentally found VDE tendencies with size. Interior states in a solvent cavity are stabilized significantly stronger than electron states on cluster surfaces. Although we find that all the examined quantum chemistry methods more or less overestimate the strength of the experimental excess electron stabilization, MP2, LC-BLYP, and BHandHLYP methods with diffuse basis sets provide a significantly better estimate of the VDE than traditional DFT methods (BLYP, B3LYP, X3LYP, PBE0). A comparison to the better performing many electron methods indicates that the examined one-electron pseudopotential can be reasonably used in simulations for systems of larger size.

Can turned inward patella predict an excess of femoral anteversion during gait in spastic diplegic children?

Science.gov (United States)

Simon, Anne-Laure; Presedo, Ana; Ilharreborde, Brice; Mallet, Cindy; Mazda, Keyvan; Penneçot, Georges-François

2014-06-01

Determining patellar orientation in the transverse plane during observational gait analysis is a fundamental aspect of physical examinations. Many physicians consider that an abnormal position of the patella in the transverse planes is only explained by a rotational abnormality of the proximal femur. A total of 188 spastic diplegic children with cerebral palsy were reviewed (376 lower limbs). The physical examination included observation of patellar orientation at midstride and measuring femoral anteversion (FA). All patients also underwent 3-dimensional (3D) computerized gait analysis of pelvic and hip rotation kinematics. Observational gait analysis and videotapes found 103 children (206 lower limbs) with inturned patella at midstance. Kinematic data from 3D gait analysis showed that the visual impression of turned inward patella was erroneous in 48 limbs. Of the remaining 158 lower limbs, 117 (74%) exhibited excessive FA and 41 (26%) did not. Of the 117 with excessive FA, kinematics showed only 66 (56%) with excessive internal hip rotation (with or without excessive internal pelvic rotation). Of the 41 lower limbs without excessive FA, 25 were explained by excessive internal pelvic rotation and 16 were explained by excessive internal hip rotation (isolated spasticity and/or contracture of internal rotator muscles). Turned inward patella was caused by isolated excessive internal pelvic rotation in 48%, excessive internal hip rotation in 35% (including 44 cases with excessive FA and 12 cases with isolated spasticity and/or contracture of internal hip rotators), and excessive internal hip rotation combined with excessive internal pelvic rotation in 17%. Excessive FA was not the only cause of turned inward patella gait and could not explain this gait anomaly by itself. Excessive internal pelvic rotation was the most frequent cause of turned inward patella gait. Level IV.

Stringy origin of diboson and dijet excesses at the LHC

Directory of Open Access Journals (Sweden)

Luis A. Anchordoqui

2015-10-01

Full Text Available Very recently, the ATLAS and CMS Collaborations reported diboson and dijet excesses above standard model expectations in the invariant mass region of 1.8–2.0 TeV. Interpreting the diboson excess of events in a model independent fashion suggests that the vector boson pair production searches are best described by WZ or ZZ topologies, because states decaying into W+W− pairs are strongly constrained by semileptonic searches. Under the assumption of a low string scale, we show that both the diboson and dijet excesses can be steered by an anomalous U(1 field with very small coupling to leptons. The Drell–Yan bounds are then readily avoided because of the leptophobic nature of the massive Z′ gauge boson. The non-negligible decay into ZZ required to accommodate the data is a characteristic footprint of intersecting D-brane models, wherein the Landau–Yang theorem can be evaded by anomaly-induced operators involving a longitudinal Z. The model presented herein can be viewed purely field-theoretically, although it is particularly well motivated from string theory. Should the excesses become statistically significant at the LHC13, the associated Zγ topology would become a signature consistent only with a stringy origin.

Excessive infant crying: Definitions determine risk groups

NARCIS (Netherlands)

Reijneveld, S.A.; Brugman, E.; Hirasing, R.A.

2002-01-01

We assessed risk groups for excessive infant crying using 10 published definitions, in 3179 children aged 1-6 months (response: 96.5%). Risk groups regarding parental employment, living area, lifestyle, and obstetric history varied by definition. This may explain the existence of conflicting

Multiresolution persistent homology for excessively large biomolecular datasets

Energy Technology Data Exchange (ETDEWEB)

Xia, Kelin; Zhao, Zhixiong [Department of Mathematics, Michigan State University, East Lansing, Michigan 48824 (United States); Wei, Guo-Wei, E-mail: wei@math.msu.edu [Department of Mathematics, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824 (United States)

2015-10-07

Although persistent homology has emerged as a promising tool for the topological simplification of complex data, it is computationally intractable for large datasets. We introduce multiresolution persistent homology to handle excessively large datasets. We match the resolution with the scale of interest so as to represent large scale datasets with appropriate resolution. We utilize flexibility-rigidity index to access the topological connectivity of the data set and define a rigidity density for the filtration analysis. By appropriately tuning the resolution of the rigidity density, we are able to focus the topological lens on the scale of interest. The proposed multiresolution topological analysis is validated by a hexagonal fractal image which has three distinct scales. We further demonstrate the proposed method for extracting topological fingerprints from DNA molecules. In particular, the topological persistence of a virus capsid with 273 780 atoms is successfully analyzed which would otherwise be inaccessible to the normal point cloud method and unreliable by using coarse-grained multiscale persistent homology. The proposed method has also been successfully applied to the protein domain classification, which is the first time that persistent homology is used for practical protein domain analysis, to our knowledge. The proposed multiresolution topological method has potential applications in arbitrary data sets, such as social networks, biological networks, and graphs.

Financial Instability - a Result of Excess Liquidity or Credit Cycles?

DEFF Research Database (Denmark)

Heebøll-Christensen, Christian

This paper compares the financial destabilizing effects of excess liquidity versus credit growth, in relation to house price bubbles and real economic booms. The analysis uses a cointegrated VAR model based on US data from 1987 to 2010, with a particulary focus on the period preceding the global...... financial crisis. Consistent with monetarist theory, the results suggest a stable money supply-demand relation in the period in question. However, the implied excess liquidity only resulted in financial destabilizing effect after year 2000. Meanwhile, the results also point to persistent cycles of real...... house prices and leverage, which appear to have been driven by real credit shocks, in accordance with post-Keynesian theories on financial instability. Importantly, however, these mechanisms of credit growth and excess liquidity are found to be closely related. In regards to the global financial crisis...

An investigation of excess noise in transition-edge sensors on a solid silicon substrate

International Nuclear Information System (INIS)

Crowder, S.G.; Lindeman, M.A.; Anderson, M.B.; Bandler, S.R.; Bilgri, N.; Bruijn, M.P.; Chervenak, J.; Figueroa-Feliciano, E.; Finkbeiner, F.; Germeau, A.; Hoevers, H.F.C.; Iyomoto, N.; Kelly, R.; Kilbourne, C.A.; Lai, T.; Man, J.; McCammon, D.; Nelms, K.L.; Porter, F.S.; Rocks, L.; Saab, T.; Sadleir, J.; Vidugiris, G.

2006-01-01

Transition-edge sensors (TESs) exhibit two major types of excess noise above the expected and unavoidable thermodynamic fluctuation noise (TFN) to the heat sink and Johnson noise. High-resistance TESs such as those made by the Netherlands Institute for Space Research (SRON) show excess noise consistent with internal TFN (ITFN) caused by random energy transport within the TES itself while low resistance TESs show an excess voltage noise of unknown origin seemingly unrelated to temperature fluctuations. Running a high-resistance TES on a high thermal conductivity substrate should suppress ITFN and allow detection of any excess voltage noise. We tested two TESs on a solid silicon substrate fabricated by SRON of a relatively high normal state resistance of ∼200 mΩ. After determining a linear model of the TES response to noise for the devices, we found little excess TFN and little excess voltage noise for bias currents of up to ∼20 μA

Excessive drinking and history of unemployment and cohabitation in Danish men born in 1953

DEFF Research Database (Denmark)

Kriegbaum, Margit; Christensen, Ulla; Osler, Merete

2011-01-01

Background: Few studies exist on social inequality of excessive drinking in Denmark and differences seem to be less pronounced than in other European countries. The aims of this study were to investigate how history of employment and cohabitation is associated with excessive drinking and to study...... interaction between both. Methods: Birth-cohort study of 6112 Danish men born in 1953 with follow-up in 2004 on excessive drinking at age 51 years. RESULTS: Excessive drinking (between 22 and 35 units of alcohol per week) differed little depending on history of unemployment and cohabitation. Risk of very......-ranging from 6 to 9 years (OR 1.73, 95% CI 1.30-2.29) to =10 years (OR 2.55, 95% CI 2.04-3.55). We found an interaction between the number of job-losses and of broken partnerships in relation to very excessive drinking. CONCLUSIONS: Very excessive drinking is related to number of job-losses, broken...

Reduction of excess sludge production using mechanical disintegration devices.

Science.gov (United States)

Strünkmann, G W; Müller, J A; Albert, F; Schwedes, J

2006-01-01

The usability of mechanical disintegration techniques for the reduction of excess sludge production in the activated sludge process was investigated. Using three different disintegration devices (ultrasonic homogeniser, stirred media mill, high pressure homogeniser) and different operational parameters of the disintegration, the effect of mechanical disintegration on the excess sludge production and on the effluent quality was studied within a continuously operated, laboratory scale wastewater treatment system with pre-denitrification. Depending on the operational conditions and the disintegration device used, a reduction of excess sludge production of up to 70% was achieved. A combination of mechanical disintegration with a membrane bioreactor process with high sludge age is more energy effective concerning reduction of sludge production than with a conventional activated sludge process at lower sludge ages. Depending on the disintegration parameters, the disintegration has no, or only minor, negative effect on the soluble effluent COD and on the COD-removal capacity of the activated sludge process. Nitrogen-removal was slightly deteriorated by the disintegration, whereas the system used was not optimised for nitrogen removal before disintegration was implemented.

[Consumption of free sugars and excess weight in infants. A longitudinal study].

Science.gov (United States)

Jardí, Cristina; Aranda, Núria; Bedmar, Cristina; Ribot, Blanca; Elias, Irene; Aparicio, Estefania; Arija, Victoria

2018-05-14

The consumption of free sugars has been related to excess weight, with the WHO recommending an intake of <10% of total energy. The aim of this study is to assess the association between the consumption of free sugars at 12 months and the risk of excess weight at 30 months in healthy children. A longitudinal study was conducted on 81 children followed-up from birth to 30 months. A record was made of the clinical history and anthropometry, at birth, and at 12 and 30 months. Weight status was classified as with or without excess weight, according to WHO values. At 12 months, the intake of energy and nutrients was analysed by differentiating the intake of free and natural sugars. Multivariate analyses adjusted for the main confounding variables were performed. Free sugars were consumed by 40.4% of the 12-month-old children, being higher than that recommended, and being significantly higher in children with excess weight at 30 months (60.9%). The higher intake of free sugars at 12 months is associated with an increased risk of excess weight at 30 months (OR: 1.130, 95% CI: 1.032-1.238). The consumption of free sugars is much higher than that recommended in 12-month-old infants. This high intake could be a risk factor for excess weight, even at early ages. Copyright © 2018. Publicado por Elsevier España, S.L.U.

Copper(I)-Catalyzed Asymmetric Desymmetrization through Inverse-Electron-Demand aza-Diels-Alder Reaction: Efficient Access to Tetrahydropyridazines Bearing a Unique α-Chiral Silane Moiety.

Science.gov (United States)

Wei, Liang; Zhou, Yu; Song, Zhi-Min; Tao, Hai-Yan; Lin, Zhenyang; Wang, Chun-Jiang

2017-04-11

An unprecedented copper(I)-catalyzed asymmetric desymmetrization of 5-silylcyclopentadienes with in situ formed azoalkene was realized through an inverse-electron-demand aza-Diels-Alder reaction (IEDDA) pathway, in which 5-silylcyclopentadienes served as efficient enophiles. This new protocol provides a facile access to the biologically important heterocyclic tetrahydropyridazines containing a unique α-chiral silane motif and three adjoining stereogenic centers in generally good yield (up to 92 %) with exclusive regioselectivity, high diastereoselectivity (>20:1 diastereomeric ratio), and excellent enantioselectivity (up to 98 % enantiomeric excess). DFT calculations and control experiments further confirmed the proposed reaction mechanism. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis of racemic, R- and S-[1-11C]-β-hydroxybutyric acid

International Nuclear Information System (INIS)

Thorell, J.-O.; Stone-Elander, S.; Karolinska Hospital and Inst., Stockholm; Koenig, W.A.; Halldin, C.; Widen, L.

1991-01-01

Racemic, R- and S-β-hydroxybutyric acid were labelled with 11 C in the carboxylic position by a two-step stereospecific synthesis starting with carrier-added [ 11 C]cyanide and R/S, R- or S-propylene oxide. Hydrolysis of the intermediate nitrile with hydrochloric acid gave racemic [1- 11 C]-β-hydroxybutyric acid and R- or S-[1- 11 C]-β-hydroxybutyric acid with an enantiomeric excess of 87-97%. The total synthesis time (including HPLC purification) was 45-50 min from end of trapping. The isolated decay-corrected radiochemical yield was 20-30% based on [ 11 C]cyanide. The radiochemical purity of the products was > 99%]. (author)

Asymmetric allylation of α-ketoester-derived N-benzoylhydrazones promoted by chiral sulfoxides/N-oxides Lewis bases: highly enantioselective synthesis of quaternary α-substituted α-allyl-α-amino acids.

Science.gov (United States)

Reyes-Rangel, Gloria; Bandala, Yamir; García-Flores, Fred; Juaristi, Eusebio

2013-09-01

Chiral sulfoxides/N-oxides (R)-1 and (R,R)-2 are effective chiral promoters in the enantioselective allylation of α-keto ester N-benzoylhydrazone derivatives 3a-g to generate the corresponding N-benzoylhydrazine derivatives 4a-g, with enantiomeric excesses as high as 98%. Representative hydrazine derivatives 4a-b were subsequently treated with SmI2, and the resulting amino esters 5a-b with LiOH to obtain quaternary α-substituted α-allyl α-amino acids 6a-b, whose absolute configuration was assigned as (S), with fundament on chemical correlation and electronic circular dichroism (ECD) data. © 2013 Wiley Periodicals, Inc.

Excessive Daytime Sleepiness and Unintended Sleep Episodes Associated with Parkinson’s Disease

Directory of Open Access Journals (Sweden)

Fatai Salawu

2015-01-01

Full Text Available This article looks at the issues of excessive daytime sleepiness and unintended sleep episodes in patients with Parkinson’s disease (PD and explores the reasons why patients might suffer from these symptoms, and what steps could be taken to manage them. During the last decade, understanding of sleep/wake regulation has increased. Several brainstem nuclei and their communication pathways in the ascending arousing system through the hypothalamus and thalamus to the cortex play key roles in sleep disorders. Insomnia is the most common sleep disorder in PD patients, and excessive daytime sleepiness is also common. Excessive daytime sleepiness affects up to 50% of PD patients and a growing body of research has established this sleep disturbance as a marker of preclinical and premotor PD. It is a frequent and highly persistent feature in PD, with multifactorial underlying pathophysiology. Both age and disease-related disturbances of sleep-wake regulation contribute to hypersomnia in PD. Treatment with dopamine agonists also contribute to excessive daytime sleepiness. Effective management of sleep disturbances and excessive daytime sleepiness can greatly improve the quality of life for patients with PD.

Variables of excessive computer internet use in childhood and adolescence

OpenAIRE

Thalemann, Ralf

2010-01-01

The aim of this doctoral thesis is the characterization of excessive computer and video gaming in terms of a behavioral addiction. Therefore, the development of a diagnostic psychometric instrument was central to differentiate between normal and pathological computer gaming in adolescence. In study 1, 323 children were asked about their video game playing behavior to assess the prevalence of pathological computer gaming. Data suggest that excessive computer and video game players use thei...

A Portable Burn Pan for the Disposal of Excess Propellants

Science.gov (United States)

2016-06-01

2013 - 06/01/2016 A Portable Burn Pan for the Disposal of Excess Propellants Michael Walsh USA CRREL USA CRREL 72 Lyme Road Hanover, NH 03755...Army Alaska XRF X-Ray Florescence vii ACKNOWLEDGEMENTS Project ER-201323, A Portable Burn Pan for the Disposal of Gun Propellants, was a very...contamination problem while allowing troops to train as they fight, we have developed a portable training device for burning excess gun propellants. 1.1

26 CFR 513.7 - Release of excess tax withheld at source.

Science.gov (United States)

2010-04-01

... source from life annuities and pensions, other than pensions paid by the Government of the United States... 26 Internal Revenue 19 2010-04-01 2010-04-01 false Release of excess tax withheld at source. 513.7...) REGULATIONS UNDER TAX CONVENTIONS IRELAND Withholding of Tax § 513.7 Release of excess tax withheld at source...

Management of Excess Reactive Nitrogen in the Environment

Science.gov (United States)

Galloway, J. N.; Theis, T.; Doering, O.

2011-12-01

Managing the impacts of excessive reactive nitrogen (Nr) in the environment is a complex problem that begins with the recognition of the obligate dietary need for Nr by all living populations. The human solution to this need has been to devise ways to bring Nr into the biosphere (via the Haber-Bosch process) to grow food. Other Nr is created as a by-product of fossil-fuel combustion. The net result is the introduction of more than five times the Nr created by natural processes in the U.S., only a fraction of which is converted back to diatomic nitrogen through denitrification. This presentation summarizes findings and recommendations of the newly-released US EPA Science Advisory Board's Integrated Nitrogen Committee report, "Reactive Nitrogen in the United States: An Analysis of Flows, Consequences, and Management Options", that deal specifically with approaches for solving the excess Nr problem. These can be grouped into four general areas: (1) Recognition of the Problem. Until there is recognition that excess Nr is a serious problem with economic, health, and societal consequences, there will be little willingness to expend resources on this issue. Education, communication and outreach are critically important to engender in regulators, and the public at large, sufficient will to undertake the large scale effort needed to reduce Nr in the environment. (2) Development of Integrated Regulatory Approaches. Given what is known about the way Nr behaves, efforts to deal with excess Nr must be organized in a way that reflects the nature of the problem. Unfortunately, most approaches tend to conceive of Nr issues within a narrowly focused disciplinary model, and our policy and regulatory institutions are often bound by enabling legislation that stresses source-by-source, chemical-by-chemical, and media-by-media. The resulting regulatory structure that has evolved for problems such as Nr that affect human health and the environment is apt to miss the complex nature of the

Polyurethane foam pica in a patient with excessive interdialytic weight gain

Science.gov (United States)

Iyasere, Osasuyi; Allington, Ying; Cafferkey, Michele

2010-01-01

Maintaining fluid balance in haemodialysis patients is important because of the adverse effects of excessive interdialytic weight gain. This often requires fluid restriction that patients often struggle with. We report a case of a 31-year-old female diabetic patient on haemodialysis with repeated excessive interdialytic weight gains despite fluid restriction and dry weight adjustment. It was subsequently discovered that she devised an unusual, albeit unsuccessful, strategy of eating the polyurethane foam from her dialysis chair while increasing her fluid intake hoping that it would absorb excess water in the gut! This under-diagnosed phenomenon known as pica has been reported in renal patients with substances such as ice, clay and baking soda. PMID:22767521

Galactic bulge preferred over dark matter for the Galactic centre gamma-ray excess

Science.gov (United States)

Macias, Oscar; Gordon, Chris; Crocker, Roland M.; Coleman, Brendan; Paterson, Dylan; Horiuchi, Shunsaku; Pohl, Martin

2018-05-01

An anomalous gamma-ray excess emission has been found in the Fermi Large Area Telescope data1 covering the centre of the Galaxy2,3. Several theories have been proposed for this `Galactic centre excess'. They include self-annihilation of dark-matter particles4, an unresolved population of millisecond pulsars5, an unresolved population of young pulsars6, or a series of burst events7. Here, we report on an analysis that exploits hydrodynamical modelling to register the position of interstellar gas associated with diffuse Galactic gamma-ray emission. We find evidence that the Galactic centre excess gamma rays are statistically better described by the stellar over-density in the Galactic bulge and the nuclear stellar bulge, rather than a spherical excess. Given its non-spherical nature, we argue that the Galactic centre excess is not a dark-matter phenomenon but rather associated with the stellar population of the Galactic bulge and the nuclear bulge.

Influences of optical-spectrum errors on excess relative intensity noise in a fiber-optic gyroscope

Science.gov (United States)

Zheng, Yue; Zhang, Chunxi; Li, Lijing

2018-03-01

The excess relative intensity noise (RIN) generated from broadband sources degrades the angular-random-walk performance of a fiber-optic gyroscope dramatically. Many methods have been proposed and managed to suppress the excess RIN. However, the properties of the excess RIN under the influences of different optical errors in the fiber-optic gyroscope have not been systematically investigated. Therefore, it is difficult for the existing RIN-suppression methods to achieve the optimal results in practice. In this work, the influences of different optical-spectrum errors on the power spectral density of the excess RIN are theoretically analyzed. In particular, the properties of the excess RIN affected by the raised-cosine-type ripples in the optical spectrum are elaborately investigated. Experimental measurements of the excess RIN corresponding to different optical-spectrum errors are in good agreement with our theoretical analysis, demonstrating its validity. This work provides a comprehensive understanding of the properties of the excess RIN under the influences of different optical-spectrum errors. Potentially, it can be utilized to optimize the configurations of the existing RIN-suppression methods by accurately evaluating the power spectral density of the excess RIN.

On the concept of critical surface excess of micellization.

Science.gov (United States)

Talens-Alesson, Federico I

2010-11-16

The critical surface excess of micellization (CSEM) should be regarded as the critical condition for micellization of ionic surfactants instead of the critical micelle concentration (CMC). There is a correspondence between the surface excesses Γ of anionic, cationic, and zwitterionic surfactants at their CMCs, which would be the CSEM values, and the critical association distance for ionic pair association calculated using Bjerrum's correlation. Further support to this concept is given by an accurate method for the prediction of the relative binding of alkali cations onto dodecylsulfate (NaDS) micelles. This method uses a relative binding strength parameter calculated from the values of surface excess Γ at the CMC of the alkali dodecylsulfates. This links both the binding of a given cation onto micelles and the onset for micellization of its surfactant salt. The CSEM concept implies that micelles form at the air-water interface unless another surface with greater affinity for micelles exists. The process would start when surfactant monomers are close enough to each other for ionic pairing with counterions and the subsequent assembly of these pairs becomes unavoidable. This would explain why the surface excess Γ values of different surfactants are more similar than their CMCs: the latter are just the bulk phase concentrations in equilibrium with chemicals with different hydrophobicity. An intriguing implication is that CSEM values may be used to calculate the actual critical distances of ionic pair formation for different cations, replacing Bjerrum's estimates, which only discriminate by the magnitude of the charge.